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42,854,798 | https://en.wikipedia.org/wiki/Ratter%20%28dog%29 | A ratter is any dog used for catching and killing rats and similar vermin. Specialized rat-catching breeds are found in many countries. A typical ratter is small to medium-sized and has a short and smooth coat, however a wide range of dog breeds and landraces may be used. The use of ratting dogs is widely considered to be the most environmentally friendly, humane and efficient methods of exterminating rodents. Ratting dogs are considered more efficient than domestic cats.
History
Ratting has existed for centuries, especially in Europe. The Centers for Disease Control and Prevention list over 20 diseases directly linked to rats, making ratting dogs popular as a way of curbing disease Rats are associated with damage to crops and buildings. In Medieval times, rat-catchers were employed to curb the spread of disease. Rat-catchers who employed dogs were considerably more successful and rat-catchers with packs of ratting dogs would frequently travel from town to town.
Many of the first documented ratters were during the mid to late 1800s in the United Kingdom. As the population in London grew, overcrowding and inadequate waste management systems caused the hygiene levels to fall and the use of rat-catchers and their ratting dogs rose in popularity.
The Guinness Book of World Records lists as the "fastest canine rat catcher" a bull-and-terrier dog named Billy, who killed 100 rats in 5 minutes 30 seconds (average of one rat every 3.3 seconds) at an event in 1825. Guinness also credits Billy with having killed 4000 rats within a 17-hour period (average of one rat every 15.3 seconds) on an unspecified occasion; other sources, including the 1993 edition of Atlas of Dog Breeds of the World, credit him with killing 2501 rats within a 7-hour period (average of one rat every 10 seconds).
During World War I, ratting dogs were used to control rat populations in trenches.
The use of ratting dogs is increasing again in many areas as rats have developed an immunity to rat poisons. Ryders Alley Trencher-fed Society (R.A.T.S.) is a New York City group founded in the 1990s that conducts organized rat hunting with dogs. The group was named by founding member Richard Reynolds after Ryders Alley in Manhattan, which was once rat infested, and the trencher-fed pack assembled to hunt. The group often hunts in Lower Manhattan locations like Theatre Alley where garbage is accessible to vermin.
Sport
Rat-baiting is a blood sport that involves releasing captured rats in an enclosed space with spectators betting on how long a dog, usually a terrier, takes to kill the rats. It is now illegal in most countries.
An earthdog trial tests the working ability and instinct of the small, often short-legged terriers or Dachshunds. Earthdog trials involve man-made tunnels that the dogs must navigate, while scenting a rat, "the quarry". The dog must follow the scent to the quarry and then "work" the quarry. Depending on the sanctioning organization, "working" means barking, scratching, staring, pawing, digging; any active behavior. The quarry is protected at all times by wooden bars across the end of the tunnel. The hunting encounter is controlled, and neither the dog nor the quarry (usually two rats) are endangered by the activity.
Barn Hunt is the competitive sport of finding rats hidden within hay bales. Tame rats are placed in a hard tube to prevent injury and hidden in hay bales while the dogs find them.
Ratter breeds
Among the many breeds used for ratting are several terriers, various pinschers and schnauzers, and the breeds of Spain. Rat-catchers will also use cross-breed dogs to catch rats. including lurchers and pointer crosses.
Terriers and Feists
A terrier is a dog of any one of many breeds or landraces of the terrier type, which are typically small, wiry, game, and fearless. A feist is a small hunting dog crossed with a terrier, developed in the rural South by breeders for hunting small game and eliminating vermin. Terrier and feists commonly used as ratters include:
Airedale Terrier
Bedlington Terrier
Border Terrier
Brazilian Terrier
Cairn Terrier
Chilean Fox Terrier
Irish Terrier
Jack Russell Terrier
Jadgterrier
Lakeland Terrier
Manchester Terrier
Miniature Fox Terrier
Mountain Feist
Norfolk Terrier
Norwich Terrier
Parsons Russell Terrier
Patterdale Terrier
Plummer Terrier
Pražský Krysařík
Rat Terrier
Teddy Roosevelt Terrier
Tenterfield Terrier
West Highland White Terrier
Yorkshire Terrier
Ratoneros
There are five regional breeds of ratonero or ratter in Spain:
Ratonero Bodeguero Andaluz from Andalusia
Ca Rater Mallorquí or Ratonero Mallorquín of Mallorca
Ratonero Murciano from Murcia
Valencian Terrier or Ratonero Valenciano of Valencia
Villanuco de Las Encartaciones in the Basque Country
Pinschers and Schnauzers
Many dogs of pinscher and schnauzer type were traditionally used to catch rats; modern breeds derived from those include:
Affenpinscher
Austrian Pinscher
Danish-Swedish Farmdog
Dutch Smoushond
German Pinscher
Miniature Pinscher
Miniature Schnauzer
Standard Schnauzer
Other
Brussels Griffon
Dachshund
Lurcher
Schipperke
Small Međimurje Dog
References
Dog types
Mammal pest control
Pest control | Ratter (dog) | [
"Biology"
] | 1,137 | [
"Pests (organism)",
"Pest control"
] |
42,854,839 | https://en.wikipedia.org/wiki/RW%20Ursae%20Minoris | RW Ursae Minoris (Nova Ursae Minoris 1956) is a cataclysmic variable star system that flared up as a nova in the constellation Ursa Minor in 1956.
Although the nova eruption of RW UMi occurred in 1956, it was not noticed until nearly six years later when, in 1962, V. Satyvaldiev found it on sky-patrol plates of the Astrophysical Institute of the Tajik Academy of Sciences in Dushanbe. On 24 September 1956 it had an apparent magnitude of 6. It may have been as bright as magnitude 3.5 around 19 September 1956, which would have made it easily visible to the naked eye, but the full moon on 20 September 1956 would have hampered observations around that date. RW Ursae Minoris's pre-nova brightness was about magnitude 21, but early in the 21st century it was still two magnitudes brighter than that.
Novae tend to be found near the galactic plane, but RW Ursae Minoris has a galactic latitude of 33 degrees, which is far from the plane of the Milky Way. Because of this, and its large outburst amplitude, astronomers were initially unsure about whether RW Ursae Minoris was a nova in the Milky Way or a supernova in another galaxy. It was eventually identified as a nova in the galactic halo on the basis of its light curve and spectrum.
All novae are binary stars, with a "donor" star orbiting a white dwarf. The donor star is so close to the white dwarf that material from the donor is transferred to the white dwarf. In 1995 Retter and Lipkin detected a low amplitude (0.1 - 0.2 magnitude) variation in RW Ursae Minoris's brightness with a period of 1.4 hours. They argued that this 1.4 hour period is probably the orbital period of the binary pair, which would make it the shortest period orbit for any known nova.
RW Ursae Minoris is surrounded by a small nova remnant shell. In 1985, Judith Cohen reported its radius as 1 arc second based observations with the Hale Telescope. In 1995 Esenoglu et al. observed it with the Copernico 1.82 m telescope and measured a radius of ~1.5 arc seconds.
References
Ursa Minor
Novae
Ursae Minoris, RW | RW Ursae Minoris | [
"Astronomy"
] | 485 | [
"Novae",
"Ursa Minor",
"Astronomical events",
"Constellations"
] |
42,855,872 | https://en.wikipedia.org/wiki/Primitive%20decorating | Primitive decorating is a style of decorating using primitive folk art style that is characteristic of a historic or early Americana time period, typically using elements with muted colors and a rough and simple look to them. Decorating in the primitive style can incorporate either true antiques or contemporary folk art. Contemporary primitive folk art is designed to have an old or antique look but created using new materials.
Examples
Examples of antiquing techniques used by primitive folk artists include tea or coffee staining and sanding down paint to create a worn, aged look. The style is sometimes referred to as country style.
Primitive decorating often features a number of recurring themes and characters including primitive angels, barnstars, primitive crows, primitive dolls & rag dolls, saltbox houses, sheep, willow trees, primitive wooden signs, and pottery. Primitive design focuses on furniture made between the mid-18th century and the early 19th century by farmers.
A number of magazines specialize in primitive decorating.
Gallery
See also
Country Living
Interior design
Willow Tree (figurines)
References
Interior design
Architectural design
American folk art | Primitive decorating | [
"Engineering"
] | 217 | [
"Design",
"Architectural design",
"Architecture"
] |
42,856,562 | https://en.wikipedia.org/wiki/Marble%20Canyon%20Dam | The Marble Canyon Dam, also known as the Redwall Dam, was a proposed dam on the Colorado River in Arizona, United States. The dam was intended to impound a relatively small reservoir in the central portion of Marble Canyon to develop hydroelectric power. Plans centered on two sites between miles 30 and 40 in the canyon. At one point a tunnel was proposed to a site just outside Grand Canyon National Park to develop the site's full power generation potential, reducing the Colorado River to a trickle through the park.
Although first proposed in the 1920s to generate hydroelectricity, work did not begin until the dam was incorporated as part of the U.S. Bureau of Reclamation (USBR)'s Pacific Southwest Water Plan in the 1940s for its Central Arizona component. Together with Bridge Canyon Dam, located at the lower end of the Grand Canyon, it would have provided the hydroelectric power necessary to lift Colorado River water from Lake Havasu to central Arizona's farms and cities, including Phoenix and Tucson. The two dams would have operated as "cash register" facilities to provide funds for future reclamation projects through the sale of cheap hydropower.
After a series of studies and site investigations, the dam was abandoned as a project in order to facilitate legislation creating the Central Arizona Project. The dam sites were incorporated into Marble Canyon National Monument in 1968, which was absorbed into Grand Canyon National Park in 1975.
Project description
First proposed in the 1940s by the United States Bureau of Reclamation, the location in Marble Canyon was regarded as one of the most remote and difficult-to-access dam sites in the United States, about below the rim of the canyon. The proposed dam was of moderate size, about high, using a thin-arch concrete design and retaining about 363,000 acre-feet. To keep the small reservoir free of silt, silt retention dams were needed on the tributary canyons. The retention dam in Paria Canyon was planned to be tall, and only wide at the base and wide at the crest, retaining 100 years of silt deposits. Despite these measures, the Marble Canyon reservoir was projected to have a lifespan of 104 years before filling with silt.
One appealing aspect of a Marble Canyon damsite was the potential to develop the Grand Canyon's hydroelectric potential without building a dam or reservoir in Grand Canyon National Park, by diverting about 90% of the Colorado River's waters at Marble Canyon into a tunnel, in diameter and capable of carrying about , to a site in the western part of the canyon in what was then Kaibab National Forest. The plan would provide about of hydraulic head for power generation. The power plant would produce about 6.5 billion kilowatt hours (KWh) per year – almost twice that of Hoover Dam. The tunnel would allow the hydroelectric system to effectively bypass Grand Canyon National Park, avoiding the construction of more dams within the park between Marble and Bridge. A flow of would be released from Marble Canyon at all times – a "scenic trickle" – for wildlife and recreational purposes in the Grand Canyon. This water would be released through a 22 megawatt power station at the base of the dam, with an annual energy production of 164 million kilowatt hours. Together, the two dams would utilize most of the elevation drop between Lee's Ferry and Lake Mead, which represents one of the biggest untapped hydroelectric potentials in the United States.
A number of accessory lakes or pools were projected in the adjacent Deer Creek drainage, or possibly at a dam on Kanab Creek. The power station at Deer Creek would have been at the head of the reservoir backed up by the never-built Bridge Canyon Dam. By the 1960s the tunnel project had been dropped in favor of a 600 MW power station at the dam's base, reducing the project's costs considerably.
The two dams would be operated as "cash register" power plants, meaning that sale of hydroelectricity would pay for their construction cost as well as provide funds for future reclamation projects. The power thus produced would be vital for pumping along the Central Arizona Project (CAP), which would lift water from the Colorado River near Lake Havasu to central and southern Arizona. The pumped water would reach as far as Tucson, which sits about higher than the Colorado River. The Bureau had even grander visions, too: eventually, this generated revenue would be necessary to fund water import projects from the Columbia River system to the Colorado River, which continues to face shortages due to over-appropriation of its flow. Thus, "hydropower at Bridge and Marble Canyon Dams was viewed as an instrument and not as a major goal in itself".
Exploration
The feasibility of Marble Canyon Dam was first explored in the 1920s by the United States Geological Survey, which designated sites for "an unbroken string of [hydroelectric] dams from the mountains of Colorado and Wyoming to the last canyons of the Colorado River along the California/Arizona border". Although the Bureau of Reclamation expressed interest at this time in developing hydroelectric generation at the Marble site, these plans were postponed in favor of building the Hoover Dam, which would provide a much greater storage capacity for irrigation and flood control. However, once Hoover was completed the Bureau once again set its sights on the Grand Canyon, which has the greatest hydroelectric potential of any canyon in the American Southwest. In the late 1940s, crews led by Bureau engineer Bert Lucas began to survey Marble Canyon and identified at least two suitable dam sites, one below Lee's Ferry and the second at . A road had to be built to connect the nearest highway to "one of the most inaccessible damsites ever explored by Bureau of Reclamation engineers".
In 1949 the Bureau opened bids for the construction of a cableway to transport workers and materials down into the remote canyon at Mile 32.8. Once the cableway was completed, a temporary camp was set up on the bottom of the gorge, and exploratory drilling work commenced in 1951. The work at the lower site at river mile 39.5 left two drifts measuring about by and about deep in the cliffs on either side of the river, together with 32 drill holes in the river bed. At the upper site, about upstream at river mile 32.8, there were a total of 35 drill holes and two drifts and deep. The work sites were accessed by an aerial tram from the rim. Although the lower site was preferred due to an additional of hydraulic head and potentially 45% larger reservoir than was possible at the upper site, it required more work to remediate weak rock joints. The project was not pursued by the Bureau of Reclamation in the 1950s. In 1960 the Arizona Power Authority became interested in the site, whose reservoir would have been entirely in Arizona, giving the state control over the waters and power generation. In 1963 the effort was endorsed by Bureau of Reclamation director Floyd Dominy. Investigations for the project's feasibility report extended into 1964. In 1965 a Bureau of Reclamation report concluded that solution cavities in the upstream limestone would prevent the reservoir from holding water. By 1968, as part of a bargain between the Arizona delegation to Congress, which supported the Central Arizona Project, and the California delegation, which opposed the project and the dam, the Marble Canyon project was dropped from the plan.
Abandonment
In 1969 President Lyndon B. Johnson proclaimed the establishment of Marble Canyon National Monument, effectively forestalling the possibility of a dam in Marble Canyon. In 1975 the monument was added to Grand Canyon National Park by the Grand Canyon Enlargement Act. The lower dam would have flooded a number of natural features, including Redwall Cavern and Vasey's Paradise. The upper dam was located just above the cavern, and was sometimes referred to as Redwall Dam.
References
External links
The Marble Canyon Damsite: Are We Safe from the Threat?, republished from a 1951 article in Arizona Highways on preliminary damsite exploration
Dams on the Colorado River
Dams in Arizona
Buildings and structures in Coconino County, Arizona
Colorado River Storage Project
United States Bureau of Reclamation proposed dams
Grand Canyon National Park | Marble Canyon Dam | [
"Engineering"
] | 1,618 | [
"Colorado River Storage Project"
] |
42,857,925 | https://en.wikipedia.org/wiki/Vicianose | Vicianose is a disaccharide.
Vicianin is a cyanogenic glycoside containing vicianose. The enzyme vicianin beta-glucosidase uses (R)-vicianin and water to produce mandelonitrile and vicianose.
The fruits of Viburnum dentatum appear blue. One of the major pigments is cyanidin 3-vicianoside, but the total mixture is very complex.
References
Disaccharides | Vicianose | [
"Chemistry"
] | 106 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
42,858,280 | https://en.wikipedia.org/wiki/HTC%20Desire%20SV | The HTC Desire SV is a brand of Android smartphone, manufactured by HTC Corporation.
References
External links
HTC India
Desire SV
Android (operating system) devices
Discontinued smartphones | HTC Desire SV | [
"Technology"
] | 37 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
42,858,820 | https://en.wikipedia.org/wiki/Social%20machine | A social machine is an environment comprising humans and technology interacting and producing outputs or action which would not be possible without both parties present. It can also be regarded as a machine, in which specific tasks are performed by human participants, whose interaction is mediated by an infrastructure (typically, but not necessarily, digital). The growth of social machines has been greatly enabled by technologies such as the Internet, the smartphone, social media and the World Wide Web, by connecting people in new ways.
Concept
The idea of social machines has been around for a long time, discussed as early as 1846 by Captain William Allen, and also by authors such as Norman Mailer, Gilles Deleuze and Félix Guattari.
Social machines blur the lines between computational processes and input from humans. They often take the form of collaborative online projects which produce web content, such as Wikipedia, citizen science projects like Galaxy Zoo, and even social networking site such as Twitter have also been defined as social machines. However, a social machine does not necessarily produce outcomes which directly affect the individuals or machines involved and an alternative viewpoint states that Social Machines are "rather than being an intentionally engineered piece of software - the substrate of accumulated human cross-system information sharing activities".
Nigel Shadbolt et al. say that the telos of the social machine is specific to its participants, whereas the telos of a platform is independent of its participants’ purposes; the platform is there to facilitate communication. A social machine may also spread across more than one platform, depending on how its participants interact, while a platform like Twitter could host many thousands of social machines.
An academic field investigating the idea has been active since Tim Berners-Lee's book Weaving the web. Social machines are characterised as 'social systems on the Web ... computational entities governed by both computational and social processes'. Tim Berners-Lee and James Hendler expressed some of the underlying scientific challenges with respect to AI research using semantic web technology as a point of departure.
Recent work focuses on the idea that certain social machines can be regarded as autonomous and goal-driven agents, and should be analysed and regulated as such. Nello Cristianini and Teresa Scantamburlo argued that the combination of a human society and an algorithmic regulation forms a social machine. Cristianini's book The Shortcut discusses extensively social machines as a model for many online platforms where participants automatically annotate content during usage, in this way contributing to the overall behaviour of the system.
See also
Augmented intelligence
Crowdsourcing
Government by algorithm
Human-based computation
Internet of things
Social computing
Social software
Social technology
Sociotechnical systems
References
Further reading
James Hendler and Alice Mulvehill (2016), Social Machines: The Coming Collision of Artificial Intelligence, Social Networking, and Humanity, Apress,
External links
SOCIAM: The Theory and Practice of Social Machines — slide show
Observing Social Machines Part 1: What to Observe — pre-print
Government by algorithm | Social machine | [
"Engineering"
] | 601 | [
"Government by algorithm",
"Automation"
] |
42,858,937 | https://en.wikipedia.org/wiki/TV%20Pictoris | TV Pictoris is a rotating ellipsoidal variable star in the constellation Pictor. It ranges between apparent magnitude 7.37 - 7.53 over a period of 0.85 days. It was first discovered to be variable in 1987. The system is inclined at an angle of 54 degrees to observers on Earth. It is composed of a primary star that has a radius 4.3 times that of the sun and 1.2 times its mass, and an effective (surface) temperature of 8300 K, and a secondary star with a radius 2.1 times that of the sun and 40% of its mass, and an effective temperature of 7000 K. Both stars are less massive than expected for a main sequence star of their temperatures. The secondary rotates much faster than the primary.
The system shines with a combined spectrum of A2V. Based upon an annual parallax shift of 5.14 milliarc seconds as measured by the Hipparcos satellite, this system is from Earth. Analysing and recalibrating yields a parallax of 4.70 and hence a distance of .
References
Pictoris, TV
Pictor
A-type main-sequence stars
Rotating ellipsoidal variables
Durchmusterung objects
030861
022370 | TV Pictoris | [
"Astronomy"
] | 263 | [
"Pictor",
"Constellations"
] |
42,859,184 | https://en.wikipedia.org/wiki/AE%20Pictoris | AE Pictoris is an eclipsing binary star system in the southern constellation of Pictor. This dim, blue-white hued point of light is just barely visible to the naked eye; it has an apparent visual magnitude of 6.09, which drops to magnitude 6.14 during an eclipse. The system is located around 1,430 light years away from the Sun based on parallax, and it is receding with a radial velocity of 34 km/s.
This is a spectroscopic binary system with an orbital period of 2.97 days and an eccentricity of 0.10. The minimum value of the semimajor axis for the pair is . The secondary star was only recently (in 2023) detected, making it a double-lined spectroscopic binary. It is classed as a probable eclipsing binary variable (EB:), but with some uncertainty regarding the specific type. This is a candidate runaway star system, having a peculiar velocity of relative to its neighbors. The visible component is a B-type main-sequence star with a stellar classification of B3V. it is 28 million years old with seven times the mass of the Sun. The star is radiating 2,569 times the luminosity of the Sun from its photosphere at an effective temperature of 18,700 K.
References
B-type main-sequence stars
Beta Lyrae variables
Spectroscopic binaries
Runaway stars
Pictor
Durchmusterung objects
046792
031068
2410
Pictoris, AE | AE Pictoris | [
"Astronomy"
] | 319 | [
"Pictor",
"Constellations"
] |
42,859,210 | https://en.wikipedia.org/wiki/Larssen%20sheet%20piling | Larssen sheet piling is a kind of sheet piling retaining wall. Segments with indented profiles (troughs) interlock to form a wall with alternating indents and outdents. The troughs increase resistance to bending. The segments are typically made of steel or another metal.
Larssen sheet piling was developed in 1906 by Tryggve Larssen, engineer from Bremen (Germany). Its applications include piers, oil terminals, waste storage facilities, shoreline protection, bridges, houses, buildings, dry docks, other construction sites, and for the strengthening of pond banks, preventing slumping into a pit, and flooding.
Construction
Lengths can reach 36 meters.
Each segment is flipped 180° versus the preceding segment. The segments lock together using a variety of interconnections.
The fully assembled structure is formed in a linear, circular, or other shape.
To reduce the filtering space, mixed sealant is injected. Additionally, it may be combined with the use of dowels, metal beams and pipes.
Metal dowels are hot-rolled steel and cold-rolled.
Design
Tongue Larssen - Tongue Larssens are up to 34 meters long and 80 centimeters wide. They have locks, which allow people to connect one profile to another vertically to create a sealed metal diaphragm wall. Transverse profiles can be in the shape of letters: S, Z, L or Ω (Omega) where the trough can be of varying depth.
Special Profile - Special profiles are long and narrow without locks. They usually have a wavy or trough shape to increase the resistance to bending.
Cantilever - Bending moments and shears are calculated under the assumption that the wall is a cantilever beam fixed at the bottom of the wall.
Anchored Wall Design- Bending moments, shears, and anchor force are calculated under the assumption that the wall is a beam with simple supports at the anchor elevation and at the bottom of the wall (the place where the wall moves beneath the surface of the ground. With the bottom of the wall at the penetration consistent with a factor of safety of 1, the lateral reaction at the bottom support will be zero and the lateral reaction at the upper support will be the horizontal component of the anchor force.
Applications
Larssens are used in foundation pits, coastline strengthening, bridge construction, piers, tide control, flood protection, agriculture irrigation, water reservoir and other work requiring extremely strong support in a narrow geometry.
References
Building materials | Larssen sheet piling | [
"Physics",
"Engineering"
] | 492 | [
"Building engineering",
"Construction",
"Materials",
"Building materials",
"Matter",
"Architecture"
] |
42,859,759 | https://en.wikipedia.org/wiki/Twitter%20Amplify | Twitter Amplify is a video advertising product that Twitter launched for media companies and consumer brands in May 2013. The product gives broadcasters the opportunity to publish real-time in-tweet video clips that are accompanied by pre-roll or post-roll advertisements. It is Twitter's major initiative in social television, designed to enhance the user experience with premium and timely TV highlights, enable broadcasters to reach new audiences and provide brands with a cross-platform tool for reaching the social conversation around major events.
Twitter Amplify allows the social network to profit further from the growth in digital video advertising, which is growing many times faster than TV, search, and most other digital ad markets. Online video ad revenue will reach nearly $5 billion in 2016, up from $2.8 billion in 2013, while TV ad revenue will decline by nearly 3% per year during the same time period. Analysis by Credit Suisse puts the average cost per thousand impressions (CPM) for a digital video advertisement at $24.60 rising up to $32.80 for those with interactive ad units or mobile formats – versus $2.66 for display formats.
Mechanics
Twitter Amplify allows broadcasters and rights holders to share live TV clips and video content into Twitter in real-time, giving users the opportunity to watch the social videos without leaving Twitter. For instance, if a television company purchased time on the platform, it can promote its prime-time shows and earn advertising revenue at the same time. During a show's broadcast, Twitter Amplify can send a barrage of tweets with rich media and interactive contents such as video clips and audience polls to drive people to the program. The content could include sponsor messages in the form of pre-roll ads. It is also a viral video format, as Twitter users retweet their favourite clips and push them out to their own followers, extending the reach of the videos more broadly. Twitter Amplify also allows content owners to use paid media support from sponsors and advertising partners to fund the distribution of their content across Twitter.
Discovery and distribution
One of the challenges when distributing (and consuming) video on Twitter is that many consumers have fast feeds. Twitter Amplify makes it possible to pin the social video tweet to the visible part of the feed so the user is more likely to see it and engage with it. Moreover, if a broadcaster sends a tweet from its own Twitter account, it can target only the people that are following that account (i.e. its "organic reach"). However, when a sponsor runs a paid campaign with Twitter Amplify, it can also target anyone tweeting about that topic or content at that time, or any other user who may be interested in the content (because they have followed a relevant account, tweeted against a particular hashtag or discussed an associated topic in their feed) – rather than being restricted to its own Twitter followers. Broadcasters and rights holders can therefore ensure their video tweets are seen and use paid media distribution (Twitter Amplify) to extend this reach to a much wider and relevant demographic. This audience can be many times the size of their existing, organic reach – potentially the entire audience of Twitter.
Extending viral distribution
Paid media Amplify campaigns encourage extended viral video distribution as Twitter users (that do not follow the broadcaster or rights holder directly) discover these new video tweets in their feed, pushed to them via promoted tweets, and share them with their own followers. This drives a second wave of viral distribution and greater earned media value for the broadcaster and brand.
Ad-funded distribution
By enabling broadcasters to have this extended social reach paid for by a brand sponsor – one that wants to align itself with the premium content and push its campaign message across social platforms – Twitter Amplify represents an ad-funded distribution model for content.
Partners
When it was launched, Twitter also announced it would work with a number of media companies, including Time Inc., Bloomberg Television, Discovery Channel, Vevo, Vice Media, Condé Nast Entertainment and Warner Music Group. By February 2014, all four major U.S. TV networks had signed up to the Amplify program, bringing a variety of TV content onto the social platform, in the form of real-time video clips. In March 2014, ITV became the first major broadcaster in the UK to sign up to Twitter Amplify, and BSkyB followed suit in October 2014, having been sharing video on the platform since 2013. At this time, Twitter Amplify was live in 10 countries and had more than 70 partners, including the BBC.
Twitter and its media partners are believed to be making significant revenue from its Twitter Amplify program. According to an industry source, McDonald's, Verizon and Microsoft paid seven figures each to sponsor the NFL's Amplify videos and to promote the tweets. By bringing more premium content on its platform, it also hopes to drive growth of its user base. Twitter acquired its Twitter Amplify partner in the U.S., SnappyTV, as part of its ongoing efforts to be the leader in social television. The company was helping broadcasters and rights holders to share video content both organically across social and via Twitter's Amplify program.
Recent developments
In 2016, Twitter expanded Amplify by opening it to individual publishers. Under this new feature, users can earn a portion of the revenue if they choose to include a pre-roll ad when sharing a video content.
Initially, Twitter only allowed in-stream video ads to clips and livestreams to advertisers that have been white-listed via Twitter Amplify, but in June 2018, this feature became open to all advertisers through the application's self-serve ad tool. By September of the same year, the company also began placing video contents and livestream atop Twitter users' timeline, giving them more prominent exposure.
References
External links
Company home page
Real-time web
Twitter services and applications
Digital marketing | Twitter Amplify | [
"Technology"
] | 1,228 | [
"Real-time web",
"Real-time computing"
] |
42,860,322 | https://en.wikipedia.org/wiki/Echo%20Park%20Dam | Echo Park Dam was proposed in the 1950s by the U.S. Bureau of Reclamation as a central feature of the Colorado River Storage Project. Situated on the Green River, a major tributary of the Colorado River, the dam was proposed for the Echo Park district of Dinosaur National Monument, flooding much of the Green and Yampa river valleys in the monument. The dam was bitterly opposed by preservationists, who saw the encroachment of a dam into an existing national park as another Hetch Hetchy, to be opposed as an appropriation of protected lands for development purposes. The Echo Park project was abandoned in favor of Glen Canyon Dam on the main stem of the Colorado, in lands that were not at that time protected. This was eventually regarded as a strategic mistake by conservation organizations.
Project history
The Echo Park Dam project was first proposed in 1941. Dinosaur National Monument was, at the time of its designation in 1915, a small park unit focused on the dinosaur fossil beds discovered along the Green River in 1909. The monument was expanded in 1938 to , encompassing the canyon networks of the Green and Yampa upstream from the dinosaur quarry. The newly added areas were little known to the public and to the Park Service, and the Park Service initially did not oppose the dam plans, having allied itself with the Bureau of Reclamation to develop Boulder Dam National Recreation Area (later Lake Mead National Recreation Area) and other reservoirs as public recreation facilities. The Park Service finally came out against the proposal in 1950, with director Newton B. Drury in opposition to the position of Secretary of the Interior Oscar L. Chapman, whose department controlled both the Park Service and the Bureau of Reclamation. Drury stated in the 1950 Park Service annual report that reservoir projects would "destroy or impair the beauty and interest" of the national parks.
Drury, a Republican in a Democratic administration, resigned in 1951, leading to criticism of Chapman for forcing Drury out. Drury was succeeded for eight months by Arthur Demaray, then by Conrad Wirth. Wirth took a less confrontational approach, partly under orders from Chapman to make the disagreement less public. Wirth was an advocate of public recreation lands associated with Reclamation projects, and suggested that Echo Park could become a National Recreation Area once flooded with a reservoir.
The first widely published public reaction to the Echo Park Dam proposal was a July 22, 1950 article by Bernard DeVoto in The Saturday Evening Post, entitled "Shall We Let Them Ruin Our National Parks?" Implicitly comparing the flooding of Echo Park to the Hetch Hetchy intrusion in Yosemite, the article was picked up by Reader's Digest and saw wide circulation.
The Colorado River Storage Project was proposed by the Bureau of Reclamation in the early 1950s as an integrated plan for collecting and using the waters of the upper Colorado River. Politically, the project had the backing of the upper Colorado states: Colorado, Wyoming and Utah, as well as Arizona, who had all fought with California over water allocations from the Colorado, of which California consumed a disproportionate share. Construction of storage reservoirs high on the river system would allow the upstream states more control over the water and its use.
In 1955, the new Secretary of the Interior Douglas McKay withdrew the Interior Department's support for the Echo Park Dam.
Glen Canyon Dam
Glen Canyon Dam was proposed from the beginning of the Colorado River Storage Project as the project's chief feature. Secretary of the Interior Harold Ickes had proposed the establishment of Escalante National Monument in 1936, at twice the size of Yellowstone National Park, that would have encompassed Glen Canyon and the surrounding lands. The proposal was whittled down by excluding grazing lands, and then by intervention by Utah, favoring the reservation of Glen Canyon as a reservoir site.
In the 1940s and 1950s this proposal was apparently forgotten or ignored. The Glen Canyon region was a virtually unknown wilderness, not widely regarded as particularly high in scenic value. A 1946 survey of potential recreational resources undertaken by the National Park Service in the Colorado Basin entirely omits the Glen Canyon region from its assessment, focusing instead on the Aquarius Plateau to the northwest and Monument Valley to the southeast.
The Park Service had no official opinion on Glen Canyon, since it was not a Park Service unit and was tacitly excluded from Park Service plans, while the Sierra Club, focused on the fight to keep water development out of established parks, failed to realize until it was too late that Glen Canyon possessed scenic and wilderness value even greater than Dinosaur. Sierra Club executive director David Brower's assent to a suggestion that the proposed Glen Canyon Dam be raised led Brower's critics to argue that he effectively sacrificed Glen Canyon to save Dinosaur. Brower considered the trade to be his biggest mistake.
Project details
The Echo Park project actually involved two dams: the main Echo Park Dam with a reservoir pool elevation of above sea level and a smaller afterbay dam downstream at Split Mountain, that would collect and re-regulate discharges from the main dam, assuring an even river flow. The Split Mountain pool was planned for an elevation of .
Echo Park Dam was planned for a site just downstream from Steamboat Rock, a monolith standing just below the confluence of the Green and Yampa, where the Green flows out of Echo Park, a broad wooded flatland walled by steep canyon cliffs. Located at the base of Harpers Point, the dam was to be a high concrete gravity dam. Above Echo Park, the reservoir was to flood the Canyon of Lodore, extending upstream through Browns Park. The Yampa was to be flooded as well to Lily Park. Roughly half of Steamboat Rock's height would have been underwater, along with archeological sites, caves and wilderness valleys. A Park Service report on the dam's effects on the monument called it a "lamentable intrusion" with "particularly deplorable effects" on wilderness and geological features in the monument. Electric power transmission lines would intrude into the park as well. Installed power generating capacity was to amount to 200 MW.
Split Mountain Dam, high, was to be sited a couple of miles downstream from Split Mountain, about two miles in a straight line from the Quarry Visitor Center, or about ten river miles upstream. The pool was to back up through Whirlpool Canyon to the toe of Echo Park Dam. The two dams were to create slackwater reservoirs throughout virtually the entire monument on the Green and Yampa. Although Split Mountain Dam was to have a hydraulic height of about , a penstock was planned to be built to carry water across a deep bend of the Green, taking advantage of the river's fall to create a head for power generation. The Split Mountain reservoir would have inundated Rainbow, Island and Little Rainbow Parks.
See also
Environmental history of the United States#Organizations
References
Further reading
Cohen, Michael P. The History of the Sierra Club, 1892-1970 (1988) pp. 142–186. online
Cosco, Jon M. Echo Park : struggle for preservation (1995) online
Harvey, Mark W. T. "Echo Park, Glen Canyon, and the postwar wilderness movement." Pacific Historical Review (1991): 43-67. online
Harvey, Mark W. T. "Battle for Dinosaur: Echo Park Dam and the birth of the modern wilderness movement." Montana: The Magazine of Western History (1995) 45#1: 32-45. online
Harvey, Mark W. T. A symbol of wilderness: Echo Park and the American conservation movement (University of Washington Press, 2011). online
Jenson, Debra E. "The Campaign Against Echo Park Dam and Collective Action Frame Theory: A Historical Analysis." Southwestern Mass Communication Journal 25.2 (2010). online
Jenson, Debra Elaine. Dinosaur dammed: An analysis of the fight to defeat Echo Park Dam (PhD dissertation, The University of Utah, 2014) online.
Neel, Susan Rhoades. "Newton Drury and the Echo Park Dam Controversy." Forest and Conservation History 38.2 (1994): 56-66.
Neel, Susan Rhoades. "Irreconcilable differences: Reclamation, preservation, and the origins of the Echo Park Dam controversy" (PhD dissertation, . University of California, Los Angeles, 1990).
Smith, Laura. "Resurrection after the" Blue Death": Literature, Politics, and Ecological Redemption at Glen Canyon." Western American Literature 51.1 (2016): 39-69. online
Stegner, Wallace. This is Dinosaur: Echo Park Country and Its Magic Rivers Alfred A. Knopf, Inc., 1955).
Stratton, Owen, and Phillip Sirotkin. The Echo Park Controversy (University of Alabama Press, 1959).
Turner, Tom. Sierra Club: 100 Years of Protecting Nature (1991) pp. 142–145. online
External links
A Survey of the Recreational Resources of the Colorado River Basin, compiled in 1946 by the National Park Service
Dams in Utah
Hydroelectric power plants in Utah
United States Bureau of Reclamation dams
Arch dams
Dams in the Green River (Colorado River tributary) basin
Colorado River Storage Project
United States Bureau of Reclamation proposed dams
Dinosaur National Monument | Echo Park Dam | [
"Engineering"
] | 1,853 | [
"Colorado River Storage Project"
] |
42,860,543 | https://en.wikipedia.org/wiki/Sauropod%20neck%20posture | Sauropod neck posture is a subject occasionally debated among scientists, with some favoring postures closer to horizontal whilst others a more upright posture. Research has looked at various avenues of evidence and analysis including: attempting to reconstruct the neutral posture of their necks and estimating range of motion by studying the bones; attempting to reconstruct sauropod metabolism and the energy requirements of sustaining incredibly long necks in various postures; and comparing sauropod neck anatomy to those of living animals.
Biomechanics
The biomechanics of sauropod skeletons and necks can help determine at what angle the neck was positioned.
Flexibility
In 2013, a study led by Matthew J. Cobley and published in PLOS ONE focused on the flexibility of the necks of sauropods. They compared the necks of ostriches with sauropod genera to find out how flexible the necks really were. The study noted that previous biomechanics studies found the necks to have been positioned between the extremes of a vertical, and a downward slanted neck. In conclusion, the study found that sauropod neck flexibility should not be based on osteology alone, and if it is, the results should be used with caution. Even though there is a lack of preserved muscle tissue that would determine flexibility, sauropod necks were probably less flexible than previously thought.
In 2014, Mike P. Taylor analysed the flexibility in the necks of Apatosaurus and Diplodocus. He found that Cobley et al. was incorrect in the fact that vertebrae imply the neck is less flexible than in actuality. Cobley et al. found necks to be much less flexible than in reality when cartilage was added. It was found that the cartilage between the joints would have allowed for the neck to flex far past 90°. However, Taylor noted that while the neck could flex above the vertical, the osteological neutral pose would have been around horizontal, with the habitual pose having the head held upwards in an alert pose.
Muscling
Sauropod necks were probably highly muscled to suit their feeding level. Brachiosaurus brancai (now Giraffititan) was probably a high browser, so it would have been more muscled along the neck than other sauropods like Diplodocus and Dicraeosaurus interpreted as low browsers. The tail and limb length of B. brancai would also need to be greater, to balance out the inclined neck. However, the question of whether sauropods were endothermic or ectothermic plays a major part in how sauropods were muscled, as endotherms have particularly more intestines and stomach than ectotherms. The amount of gut needed could determine how much food was eaten by sauropods, and therefore at what elevation their heads were held.
Heart and metabolic stress
The upright posture of sauropod necks is seen by some as requiring implausibly high blood pressure and heart strength. A 2000 study conducted by Roger Seymour and Harvey Lillywhite found that the blood pressure needed to reach the head with an upright neck would be , interpreted as fatal to an endotherm, or highly dangerous to an ectotherm, even with adequate heart musculature. A later study by Seymour concluded that it would have required half the animal's energy intake to pump the blood to the head. This would disfavor sauropods being high browsers, and instead having lower necks while feeding than commonly portrayed.
The above work summarily dismisses the hypothesis of secondary hearts in the neck as evolutionarily implausible, assuming arterial valves could have no role without associated musculature.
Hypotheses
A few hypotheses have been generated to solve the dispute over how sauropods held their necks.
Horizontal pose
Kent Stevens and Michael Parrish have been the two main supporters of a horizontal neck posture. In 1999, they studied the genera Apatosaurus and Diplodocus, finding the habitual pose of the genera to be slightly declined. They claimed that both sauropods had necks much less flexible than previously thought, with the neck vertebrae of Diplodocus being more inflexible than Apatosaurus. Those two poses would suggest that the sauropods were ground feeders, instead of browsing off taller flora.
Later, in 2005, Stevens and Parrish studied the biomechanics of sauropod necks on a wider variety of sauropods, from the Jurassic: Apatosaurus, Diplodocus, Camarasaurus, Brachiosaurus, Dicraeosaurus, Cetiosaurus, and Euhelopus. All were stated to have a horizontal, or even declining neck.
However, in 2009 multiple flaws were found with this argument. Michael P. Taylor et al. compared the neck posture of sauropods to that of extant reptiles and other tetrapods, finding these animals' habitual poses to be entirely different from the assumptions of Stevens and Parrish. The latters' errors come mainly from their preconceptions about animals' habitual pose in life, which they simply assumed would naturally match the Osteological Neutral Pose (or ONP). Taylor et al. find the ONP to be, not the actual habitual pose of any examined animal, but an arbitrarily chosen midpoint between the two structural extremes of bone placement. ONP, then, is merely one place in the range of physically possible motion.
Incline pose
Another, more widely supported hypothesis about sauropod neck posture is that the necks were held at an incline, but not as upright as commonly shown. Daniela Schwartz et al. in 2006 published a study of the scapula and coracoids, sometimes fused into scapulocoracoids, of sauropod genera. Previously, sauropod shoulder girdles were thought to have been positioned horizontally along the torso, but Schwartz et al. found that the girdles should not have been positioned horizontally, and instead, they would have been angled at an average of 55° to 65°. The study reconstructed the skeletons of Diplodocus, Camarasaurus, and the titanosaur Opisthocoelicaudia, all known from a complete shoulder girdle, with the correct orientation of the scapulocoracoids. For Diplodocus, a 60° shoulder blade would have meant that the neck was more-or-less horizontal, not too much different from the horizontal pose. A juvenile Camarasaurus found by Gilmore was originally described as having the scapulocoracoid in "just the right place", but with it oriented at an angle of 45°, Schwartz et al. criticized the stance. The skeleton found by Schwartz et al. with the angle of the scapulocoracoid is similar to previous reconstruction of the genus by Osborn and Mook, and Jensen. Opisthocoelicaudia was found to have had two possibly poses, both with the scapulocoracoid angled at about 60°. No previous reconstructions, unlike with Camarasaurus, have restored Opisthocoelicaudia similarly.
Upright pose for some sauropods
Despite skepticism, Euhelopus and Brachiosaurus have been found on anatomical evidence to have held their necks at a vertical angle, which has been treated as impossible for sauropods. Studies have concluded that the blood pressure and energy spent holding necks erect would have been too great to survive; yet Euhelopus and Brachiosaurus, at least, did so anyhow. The energy spent by pumping blood to the head is interpreted as too great for most sauropods, but when they travel often, which has been suggested for those two genera, it would have actually saved energy. The biomechanical evidence favours an upright neck when travelling to spread apart resources. The study finding this conclusion also tested how much energy would have been expended when walking and standing, both with an upright neck. The approximate conclusion was that an about equal amount of energy would have been used up. Elongated cervical ribs are skeletal evidence for a strong core to support the neck and limit its movement when walking. The study supports the idea that during times of drought and famine, an upright neck was crucial for these sauropods to survive.
References
Anatomy
Sauropods
Biomechanics | Sauropod neck posture | [
"Physics",
"Biology"
] | 1,713 | [
"Biomechanics",
"Mechanics",
"Anatomy"
] |
42,861,805 | https://en.wikipedia.org/wiki/Karen%20Harvey%20Prize | The Karen Harvey Prize is awarded by the American Astronomical Society's Solar Physics Division in recognition for a significant contribution to the study of the Sun early in a person's professional career.
Past winners are:
2003 Dana Longcope
2004 Harry Warren
2005 Sarah E. Gibson
2006 Steven R Cranmer
2007 Jiong Qiu
2008 Mark G. Linton
2009 Laurent Gizon
2010 Brian Welsch
2011 Mathias Rempel
2012 Dibyendu Nandi
2013 Tibor Torok
2014 Alexis Rouillard
2015 Jonathan Cirtain
2016 Katharine Reeves
2017 Mark Cheung
2018 Nicholeen Viall
2019 Anthony Yeates
2020 Hui Tian
2021 Lucia Kleint
2022 Adam Kowalski
2023 Bin Chen
See also
List of astronomy awards
References
External links
Astronomy prizes
American Astronomical Society | Karen Harvey Prize | [
"Astronomy",
"Technology"
] | 153 | [
"Science and technology awards",
"Science award stubs",
"Astronomy prizes"
] |
42,861,897 | https://en.wikipedia.org/wiki/Driven%20to%20refusal | This is an engineering term for describing how far to drive piles. It is also used in surveying when driving metal posts and monuments that are to be used as bench marks (ie. the elevation of which will be established to a high degree of accuracy). When a very high degree of stability is required the post will be inside an oil filled outer casing to protect it against movement of the surrounding ground usually because of the frost.
A rod or pile has been "driven to refusal" when five more blows of an adequate hammer will not budge the rod or pile.
References
Construction | Driven to refusal | [
"Engineering"
] | 117 | [
"Construction"
] |
42,862,457 | https://en.wikipedia.org/wiki/AEBP2 | Adipocyte Enhancer-Binding Protein is a zinc finger protein that in humans is encoded by the evolutionarily well-conserved gene AEBP2. It was initially identified due to its binding capability to the promoter of the adipocyte P2 gene, and was therefore named Adipocyte Enhancer Binding Protein 2. AEBP2 is a potential targeting protein for the mammalian Polycomb Repression Complex 2 (PRC2).
Function
AEBP2 is a DNA-binding transcriptional repressor. It may interact with and stimulate the activity of the PRC2 complex.
AEBP2 may regulate the migration and development of the neural crest cells through the PRC2-mediated epigenetic mechanism and is most likely a targeting protein for the mammalian PRC2 complex.
Clinical significance
Diseases associated with AEBP2 include Waardenburg's syndrome, and Hirschsprung's disease.
References
External links | AEBP2 | [
"Chemistry"
] | 191 | [
"Biochemistry stubs",
"Protein stubs"
] |
41,430,736 | https://en.wikipedia.org/wiki/Comparison%20of%20webcam%20software | Webcam software allows users to take pictures and video and save them to their computer.
See also
Comparison of screencasting software
Webcams
Webcam | Comparison of webcam software | [
"Technology"
] | 32 | [
"Computing stubs"
] |
41,431,119 | https://en.wikipedia.org/wiki/T%C3%BApac%20Katari%201 | Túpac Katari 1 or TKSat-1 is a telecommunications satellite that the government of Bolivia outsourced to People's Republic of China (PRC) to serve telecommunications in Bolivia, such as mobile, television and Internet use.
It was launched into orbit on 20 December 2013 from the Satellite Launch Center in Xichang, China, with a trial period of a little over three months, and commercial operation starting in March 2014.
It was built on behalf of the Bolivian Space Agency. The China Great Wall Industry Corporation (CGWIC), a subsidiary of the China Aerospace Science and Technology Corporation (CASC), was responsible for the construction (using French, German and USA technology), launch and orbit of the satellite.
The satellite is named after 18th century Bolivian independence activist Túpac Katari.
Technical issues
The satellite is geostationary and parked at 87.2° W, at a distance of 36,000 kilometers from equator; two-way voice communications are subject to latency.
The estimated useful life is 15 years; having been launched in 2013, it should be deactivated in 2028, or from now.
Cost and revenue
The satellite had a cost of around $300 million, of which $251 million was a loan from the China Development Bank (CDB) to the government of Bolivia, and the rest was paid by the government of Bolivia.
From launch to August 2017, the satellite generated revenue of $60 million. The Bolivian Space Agency said the satellite was not a business, but instead its purpose was to increase access to communications. Running expenses were not disclosed.
See also
2013 in spaceflight
Bolivia-People's Republic of China relations
References
2013 in Bolivia
2013 in China
Communications satellites
Science and technology in Bolivia
Spacecraft launched in 2013
First artificial satellites of a country | Túpac Katari 1 | [
"Astronomy"
] | 363 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
41,431,560 | https://en.wikipedia.org/wiki/Rostraureum%20tropicale | Rostraureum tropicale is a species of fungus from genus Rostraureum that is found in Ecuador.
Distribution and habitat
Rostraureum tropicale is a pathogen of Terminalia ivorensis and causes basal stem cankers on dying trees. The fungus is distributed in the lowland tropics of Ecuador. Hosts include Terminalia ivorensis and Terminalia superba (both in family Combretaceae of the Myrtales).
Morphology
Morphologically, Rostraureum tropicale has characteristics similar to those for Cryphonectria, Endothia and Chrysoporthe, but appears to be superficially closest to Cryphonectria longirostris. The fungus displays characteristics typical of diaporthalean fungi, with periphysate ostiolar canals with no paraphyses, and asci are unitunicate with refractive apical rings. Fruiting structures are orange to yellow, and ascospores are one-septate and fusoid to ellipsoid.
Rostraureum tropicale can be distinguished from Endothia, Cryphonectria and Chrysoporthe by the observation that perithecial necks are not embedded in well-developed stromatic tissue. Additionally, it can be distinguished from Chrysoporthe by the presence of orange perithecial necks instead of fuscous-black necks.
Phylogeny
Rostraureum tropicale is phylogenetically most closely related to species of Endothia, based on ribosomal (ITS) and β-tubulin DNA sequences. However, species of Chrysoporthe and Cryphonectria belong to the same superclade and are thus closely related to Rostraureum tropicale.
Pathogenicity
Rostraureum tropicale is pathogenic towards Terminalia ivorensis and a closely related host, Terminalia superba, causing well-developed stem cankers within six weeks of inoculation. It is also more pathogenic than Chrysoporthe cubensis, which causes smaller lesions on Terminalia superba. However, C. cubensis is not usually a pathogen of trees in the Combretaceae.
References
External links
Diaporthales
Fungi described in 2005
Fungi of Ecuador
Fungus species | Rostraureum tropicale | [
"Biology"
] | 458 | [
"Fungi",
"Fungus species"
] |
41,433,082 | https://en.wikipedia.org/wiki/Kepler-91b | Kepler-91b is a giant planet orbiting Kepler-91, a star slightly more massive than the Sun. Kepler-91 has left the main sequence and is now a red giant branch star.
Discovery and further confirmation
Kepler-91b was detected by analyzing the data of Kepler space telescope where a transit-like signal was found. Initially thought to be a false positive due to light curve variations by a self-luminous object, it was later revealed that due to Kepler-91's low density, its shape is distorted to a slightly ellipsoidal shape due to gravitational effects of the planet. Ellipsoidal light variations caused by Kepler-91b constitute more than the third of the light variations compared to transit depth. Ellipsoidal light variations also allowed to determine the planet's mass. It was also found that Kepler-91b reflects some of the starlight from its star.
Further analysis managed to question the planetary nature of the object, suspecting that it is a self-luminous object. However, the planetary nature was eventually confirmed again through both the radial velocity technique and re-analysis of the light curve modulations.
Characteristics
Kepler-91b is about 14% less massive than Jupiter while being more than 35% larger, making it less than half of the density of water. Kepler-91b orbits around the host star in about 6.25 days. Despite being one of the least edge-on orbits relative to Earth with inclination being about 68.5 degrees, transit was detected due to low semi-major axis to host star radius ratio.
Kepler-91b is expected to be engulfed by the parent star within about 55 million years.
Possible trojan companion
The possibility of a trojan planet to Kepler-91b was suggested due to the presence of a small dim in the phase-folded light curve at phase 0.68. This was subsequently studied but the conclusion was that the transit-signal was a false-positive.
References
External links
Technology.org: Kepler-91b: a planet at the end of its life
Exoplanets discovered in 2013
Transiting exoplanets
Exoplanets discovered by the Kepler space telescope
Lyra
Hot Jupiters | Kepler-91b | [
"Astronomy"
] | 441 | [
"Lyra",
"Constellations"
] |
41,433,885 | https://en.wikipedia.org/wiki/Co-fired%20ceramic | Co-fired ceramic devices are monolithic, ceramic microelectronic devices where the entire ceramic support structure and any conductive, resistive, and dielectric materials are fired in a kiln at the same time. Typical devices include capacitors, inductors, resistors, transformers, and hybrid circuits. The technology is also used for robust assembly and packaging of electronic components multi-layer packaging in the electronics industry, such as military electronics, MEMS, microprocessor and RF applications.
Co-fired ceramic devices are fabricated using a multilayer approach. The starting material is composite green tapes, consisting of ceramic particles mixed with polymer binders. The tapes are flexible and can be machined, for example, using cutting, milling, punching and embossing. Metal structures can be added to the layers, commonly using filling and screen printing. Individual tapes are then bonded together in a lamination procedure before the devices are fired in a kiln, where the polymer part of the tape is combusted and the ceramic particles sinter together, forming a hard and dense ceramic component.
Co-firing can be divided into low-temperature (LTCC) and high-temperature (HTCC) applications: low temperature means that the sintering temperature is below , while high temperature is around . The lower sintering temperature for LTCC materials is made possible through the addition of a glassy phase to the ceramic, which lowers its melting temperature.
Due to a multilayer approach based on glass-ceramics sheets, this technology offers the possibility to integrate into the LTCC body passive electrical components and conductor lines typically manufactured in thick-film technology. This differs from semiconductor device fabrication, where layers are processed serially, and each new layer is fabricated on top of previous layers.
History
Co-fired ceramics were first developed in the late 1950s and early 1960s to make more robust capacitors. The technology was later expanded in the 1960s to include multilayer structures similar to printed circuit boards.
Components
Hybrid circuits
LTCC technology is especially beneficial for RF and high-frequency applications. In RF and wireless applications, LTCC technology is also used to produce multilayer hybrid integrated circuits, which can include resistors, inductors, capacitors, and active components in the same package. In detail, these applications comprise mobile telecommunication devices (0.8–2 GHz), wireless local networks such as Bluetooth (2.4 GHz) to in-car radars (50–140 GHz, and 76 GHz). LTCC hybrids have a smaller initial ("non recurring") cost as compared with ICs, making them an attractive alternative to ASICs for small scale integration devices.
Inductors
Inductors are formed by printing conductor windings on ferrite ceramic tape. Depending on the desired inductance and current carrying capabilities a partial winding to several windings may be printed on each layer. Under certain circumstances, a non-ferrite ceramic may be used. This is most common for hybrid circuits where capacitors, inductors, and resistors will all be present and for high operating frequency applications where the hysteresis loop of the ferrite becomes an issue.
Resistors
Resistors may be embedded components or added to the top layer post-firing. Using screen printing, a resistor paste is printed onto the LTCC surface, from which resistances needed in the circuit are generated. When fired, these resistors deviate from their design value (±25%) and therefore require adjustment to meet the final tolerance. With Laser trimming one can achieve these resistances with different cut forms to the exact resistance value (±1%) desired. With this procedure, the need for additional discrete resistors can be reduced, thereby allowing a further miniaturization of the printed circuit boards.
Transformers
LTCC transformers are similar to LTCC inductors except transformers contain two or more windings. To improve coupling between windings transformers includes a low-permeability dielectric material printed over the windings on each layer. The monolithic nature of LTCC transformers leads to a lower height than traditional wire wound transformers. Also, the integrated core and windings mean these transformers are not prone to wire break failures in high mechanical stress environments.
Sensors
Integration of thick-film passive components and 3D mechanical structures inside one module permitted the fabrication of sophisticated 3D LTCC sensors e.g. accelerometers.
Microsystems
The possibility of the fabrication of many various passive thick-film components, sensors and 3D mechanical structures enabled the fabrication of multilayer LTCC microsystems.
Using HTCC technology, microsystems for harsh environments, such as working temperatures of 1000 °C, have been realized.
Applications
LTCC substrates can be most beneficially used for the realization of miniaturized devices and robust substrates. LTCC technology allows the combination of individual layers with different functionalities such as high permittivity and low dielectric loss into a single multilayer laminated package and thereby to achieve multi-functionality in combination with a high integration and interconnection level. It also provides the possibility to fabricate three-dimensional, robust structures enabling in combination with thick film technology the integration of passive, electronic components, such as capacitors, resistors, and inductors into a single device.
Comparison
Low-temperature co-firing technology presents advantages compared to other packaging technologies including high-temperature co-firing: the ceramic is generally fired below 1,000 °C due to a special composition of the material. This permits the co-firing with highly conductive materials (silver, copper, and gold). LTCC also features the ability to embed passive elements, such as resistors, capacitors and inductors into the ceramic package, minimising the size of the completed module.
HTCC components generally consist of multilayers of alumina or zirconia with platinum, tungsten and moly-manganese metalization. The advantages of HTCC in packaging technology includes mechanical rigidity and hermeticity, both of which are important in high-reliability and environmentally stressful applications. Another advantage is HTCC's thermal dissipation capability, which makes this a microprocessor packaging choice, especially for higher-performance processors.
Compared to LTCC, HTCC has higher-resistance conductive layers.
See also
Tape casting
Laser trimming
References
External links
Animation of LTCC production process
Packaging (microfabrication)
Electronics manufacturing | Co-fired ceramic | [
"Materials_science",
"Engineering"
] | 1,322 | [
"Electronic engineering",
"Packaging (microfabrication)",
"Electronics manufacturing",
"Microtechnology"
] |
41,435,133 | https://en.wikipedia.org/wiki/NGC%207727 | NGC 7727 is a peculiar galaxy in the constellation Aquarius. It harbors two galactic nuclei, each containing a supermassive black hole, separated 1,600 light years apart.
Features
This object is located at a distance of 23.3 megaparsecs (76 million light years) from the Milky Way and has a peculiar aspect, with several plumes and streams of irregular shape that explains its inclusion on Halton C. Arp's Atlas of Peculiar Galaxies with the number 222, being classified as a "Galaxy with amorphous spiral arms".
In all likelihood, this system is the product of the merger of two previous spiral galaxies that took place 1 billion years ago, with the aforementioned stellar plumes and streams being the remnants of the disks of the two galaxies that collided to form this object.
Two starlike objects can be seen in NGC 7727's center, at least one of them likely being the former core of one of those two spiral galaxies. In addition to this, 23 objects – candidates to be young globular clusters formed in the collision – can be found in this system.
NGC 7727 is very similar to NGC 7252, another galaxy product of the collision and merging of two former spiral galaxies, in the same constellation. However it has far less gas (neutral hydrogen and molecular hydrogen) than the latter.
NGC 7727's most likely fate is to become an elliptical galaxy in the future, with very little interstellar dust and star formation.
In November 2021, scientists announced the discovery of a pair of supermassive black holes in NGC 7727, detected with the Very Large Telescope's multi-unit spectroscopic explorer (MUSE) at the European Southern Observatory. The black holes have masses of 154 and 6.3 million solar masses, and are separated 1,600 light years apart. The pair are among the closest confirmed supermassive black holes to Earth at about 89 million light years away. Although the pair are separated closely enough to gravitationally influence each other, the smaller black hole is not bound in orbit around the larger black hole due to the surrounding mass of the NGC 7727 core region. The black holes will eventually merge in the next 250 million years, producing powerful, low-frequency gravitational waves in the process.
See also
List of nearest black holes
References
External links
Galaxy mergers
Aquarius (constellation)
7727
72060
222 | NGC 7727 | [
"Astronomy"
] | 483 | [
"Constellations",
"Aquarius (constellation)"
] |
41,435,368 | https://en.wikipedia.org/wiki/VyOS | VyOS is an open source network operating system Linux distribution based on Debian.
VyOS provides a free routing platform that competes directly with other commercially available solutions from well-known network providers. Because VyOS is run on standard amd64 systems, it can be used as a router and firewall platform for cloud deployments. VyOS can also be optimized to achieve routing at 100Gbps.
Besides being open-source, VyOS also offers subscription-based support, which includes pre-built images for cloud and virtual environments and LTS images for the 1.3 and 1.4 series.
History
After Brocade Communications stopped development of Vyatta in 2013, a group of enthusiasts created an open-source fork called VyOS, based on the last community edition, Vyatta Core 6.6R1.
They founded Sentrium S.L, a Spanish company dedicated to providing support and development for the VyOS project. On October 9, 2024, Sentrium S.L. was renamed VyOS Networks Iberia and was acquired by VyOS Networks Corporation, becoming its subsidiary.
Features
Routing and Protocols: BGP (IPv4 and IPv6), OSPF (v2 and v3), RIP and RIPng, policy-based routing, BGP-LU and enhanced route filtering. IPv4, IPv6, QoS.
VPN and Tunneling: IPsec, VTI, VXLAN, L2TPv3, L2TP/IPsec and PPTP servers, tunnel interfaces (GRE, IPIP, SIT), OpenVPN in client, server, or site-to-site modes, WireGuard.
Firewall and NAT: Stateful firewall based on nftables, zone-based firewall, all types of source and destination NAT (one to one, one to many, many to many), NAT64/DNS64.
Network Services: DHCP and DHCPv6 server and relay, IPv6 RA, DNS forwarding, HTTP load balancer, web proxy, PPPoE access concentrator, NetFlow/sFlow sensor, TFTP server.
High Availability and Load Balancing: VRRP for IPv4 and IPv6, ability to execute custom health checks and transition scripts; ECMP, stateful load balancing, failover routes.
Management and Configuration: Junos-style CLI with commands like run, set, delete, show, commit, commit-confirm, compare and versioning. Rollback without reboot, PKI repository
Automation: ansible, napalm, Netmiko, Salt Stack, cloud-init, python sdk. cloud-init ready images can be built with vyos-build or packer
Monitoring: integrations with Zabbix, FastNetMon and Prometheus/Grafana.
Platform and Image Support: VyOS images can be created using vyos-build for the following platforms: amd64, ISO, and cloud images for AWS, Azure, Edgecore, XCP-NG, Qemu/Proxmox, VMware.
Releases
VyOS version 1.0.0 (Hydrogen) was released on December 22, 2013. On October 9, 2014, version 1.1.0 (Helium) was released. All versions released thus far have been based on Debian 6.0 (Squeeze), and are available as 32-bit images and 64-bit images for both physical and virtual machines.
On January 28, 2019, version 1.2.0 (Crux) was released. Version 1.2.0 is based on Debian 8 (Jessie). While version 1.0 and 1.1 were named after elements, a new naming scheme based on constellations is used from version 1.2.
VyOS 1.3.0 (Equuleus) is based on Debian 10 (Buster) and was released on December 21, 2021. Equuleus brought many long-desired features, most notably an SSTP VPN server, an IPoE server, an OpenConnect VPN server, and a serial console server. It also included reworked support for WWAN interfaces, support for GENEVE and MACSec interfaces, VRF, IS-IS routing, preliminary support for MPLS and LDP, among many other features.
Currently, VyOS 1.4.0 (Sagitta) in GA (General Access) stage, with the latest version being VyOS 1.4.0 GA LTS. This version was developed based on Debian 12 (Bookworm).
Release History
See also
List of router and firewall distributions
References
External links
Computer networking
Debian-based distributions
Ethernet
Free routing software
Free security software
Free software distributions
Gateway/routing/firewall distribution
Linux companies
Linux distributions
Routers (computing)
Routing software
Virtualization software
Virtual private networks | VyOS | [
"Technology",
"Engineering"
] | 1,031 | [
"Computer networking",
"Computer science",
"Computer engineering"
] |
41,435,806 | https://en.wikipedia.org/wiki/Armillifer%20grandis | Armillifer grandis is a species of tongue worm in the subclass Pentastomida found in tropical Central and West Africa. Its typical definitive hosts are viperid snakes (such as Bitis gabonica, Bitis nasicornis, and Cerastes cerastes), while rodents are presumed to act as intermediate hosts. Humans may become accidentally infected by the eggs, particularly if consuming (or otherwise contacting) infected snakes. Ingested eggs develop into nymphs that invade different visceral organs, causing a disease that is often called porocephalosis. Most human infections are asymptomatic, although some cases are debilitating and even lethal. Abdominal infections are more widespread, but typically undiagnosed, while ocular manifestations are rare and may cause blindness.
Most of the vipers sold for human consumption at the rural bushmeat markets in the Democratic Republic of Congo host A. grandis.
References
Crustaceans
Crustaceans described in 1915
Parasites of reptiles
Parasites of rodents
Parasites of humans | Armillifer grandis | [
"Biology"
] | 214 | [
"Parasites of humans",
"Humans and other species"
] |
41,436,516 | https://en.wikipedia.org/wiki/Fuss%E2%80%93Catalan%20number | In combinatorial mathematics and statistics, the Fuss–Catalan numbers are numbers of the form
They are named after N. I. Fuss and Eugène Charles Catalan.
In some publications this equation is sometimes referred to as Two-parameter Fuss–Catalan numbers or Raney numbers. The implication is the single-parameter Fuss-Catalan numbers are when and .
Uses
The Fuss-Catalan represents the number of legal permutations or allowed ways of arranging a number of articles, that is restricted in some way. This means that they are related to the Binomial Coefficient. The key difference between Fuss-Catalan and the Binomial Coefficient is that there are no "illegal" arrangement permutations within Binomial Coefficient, but there are within Fuss-Catalan. An example of legal and illegal permutations can be better demonstrated by a specific problem such as balanced brackets (see Dyck language).
A general problem is to count the number of balanced brackets (or legal permutations) that a string of m open and m closed brackets forms (total of 2m brackets). By legally arranged, the following rules apply:
For the sequence as a whole, the number of open brackets must equal the number of closed brackets
Working along the sequence, the number of open brackets must be greater than the number of closed brackets
As an numeric example how many combinations can 3 pairs of brackets be legally arranged? From the Binomial interpretation there are or numerically = 20 ways of arranging 3 open and 3 closed brackets. However, there are fewer legal combinations than these when all of the above restrictions apply. Evaluating these by hand, there are 5 legal combinations, namely: ()()(); (())(); ()(()); (()()); ((())). This corresponds to the Fuss-Catalan formula when p=2, r=1 which is the Catalan number formula or =5. By simple subtraction, there are or =15 illegal combinations. To further illustrate the subtlety of the problem, if one were to persist with solving the problem just using the Binomial formula, it would be realised that the 2 rules imply that the sequence must start with an open bracket and finish with a closed bracket. This implies that there are or =6 combinations. This is inconsistent with the above answer of 5, and the missing combination is: ())((), which is illegal and would complete the binomial interpretation.
Whilst the above is a concrete example Catalan numbers, similar problems can be evaluated using Fuss-Catalan formula:
Computer Stack: ways of arranging and completing a computer stack of instructions, each time step 1 instruction is processed and p new instructions arrive randomly. If at the beginning of the sequence there are r instructions outstanding.
Betting: ways of losing all money when betting. A player has a total stake pot that allows them to make r bets, and plays a game of chance that pays p times the bet stake.
Tries: Calculating the number of order m tries on n nodes.
Special Cases
Below is listed a few formulae, along with a few notable special cases
If , we recover the Binomial coefficients
;
;
;
.
If , Pascal's Triangle appears, read along diagonals:
;
;
;
;
;
.
Examples
For subindex the numbers are:
Examples with :
, known as the Catalan Numbers
Examples with :
Examples with :
Algebra
Recurrence
equation (1)
This means in particular that from
equation (2)
and
equation (3)
one can generate all other Fuss–Catalan numbers if is an integer.
Riordan (see references) obtains a convolution type of recurrence:
equation(4)
Generating Function
Paraphrasing the Densities of the Raney distributions paper, let the ordinary generating function with respect to the index be defined as follows:
equation (5).
Looking at equations (1) and (2), when =1 it follows that
equation (6).
Also note this result can be derived by similar substitutions into the other formulas representation, such as the Gamma ratio representation at the top of this article. Using (6) and substituting into (5) an equivalent representation expressed as a generating function can be formulated as
.
Finally, extending this result by using Lambert's equivalence
.
The following result can be derived for the ordinary generating function for all the Fuss-Catalan sequences.
.
Recursion Representation
Recursion forms of this are as follows:
The most obvious form is:
Also, a less obvious form is
Alternate Representations
In some problems it is easier to use different formula configurations or variations. Below are a two examples using just the binomial function:
These variants can be converted into a product, Gamma or Factorial representations too.
See also
Combinatorics
Statistics
Binomial coefficient
Binomial Distribution
Catalan number
Dyck language
Pascal's triangle
References
Factorial and binomial topics
Enumerative combinatorics | Fuss–Catalan number | [
"Mathematics"
] | 1,007 | [
"Factorial and binomial topics",
"Enumerative combinatorics",
"Combinatorics"
] |
41,437,742 | https://en.wikipedia.org/wiki/Heap%27s%20algorithm | Heap's algorithm generates all possible permutations of objects. It was first proposed by B. R. Heap in 1963. The algorithm minimizes movement: it generates each permutation from the previous one by interchanging a single pair of elements; the other elements are not disturbed. In a 1977 review of permutation-generating algorithms, Robert Sedgewick concluded that it was at that time the most effective algorithm for generating permutations by computer.
The sequence of permutations of objects generated by Heap's algorithm is the beginning of the sequence of permutations of objects. So there is one infinite sequence of permutations generated by Heap's algorithm .
Details of the algorithm
For a collection containing different elements, Heap found a systematic method for choosing at each step a pair of elements to switch in order to produce every possible permutation of these elements exactly once.
Described recursively as a decrease and conquer method, Heap's algorithm operates at each step on the initial elements of the collection. Initially and thereafter . Each step generates the permutations that end with the same final elements. It does this by calling itself once with the element unaltered and then times with the () element exchanged for each of the initial elements. The recursive calls modify the initial elements and a rule is needed at each iteration to select which will be exchanged with the last. Heap's method says that this choice can be made by the parity of the number of elements operated on at this step. If is even, then the final element is iteratively exchanged with each element index. If is odd, the final element is always exchanged with the first.
// Output the k! permutations of A in which the first k elements are permuted in all ways.
// To get all permutations of A, use k := length of A.
//
// If, k > length of A, will try to access A out of bounds.
// If k <= 0 there will be no output (empty array has no permutations)
procedure permutations(k : integer, A : array of any):
if k = 1 then
output(A)
else
// permutations with last element fixed
permutations(k - 1, A)
// permutations with last element swapped out
for i := 0; i < k-1; i += 1 do
if k is even then
swap(A[i], A[k-1])
else
swap(A[0], A[k-1])
end if
permutations(k - 1, A)
end for
end if
One can also write the algorithm in a non-recursive format.
procedure permutations(n : integer, A : array of any):
// c is an encoding of the stack state.
// c[k] encodes the for-loop counter for when permutations(k - 1, A) is called
c : array of int
for i := 0; i < n; i += 1 do
c[i] := 0
end for
output(A)
// i acts similarly to a stack pointer
i := 1;
while i < n do
if c[i] < i then
if i is even then
swap(A[0], A[i])
else
swap(A[c[i]], A[i])
end if
output(A)
// Swap has occurred ending the while-loop. Simulate the increment of the while-loop counter
c[i] += 1
// Simulate recursive call reaching the base case by bringing the pointer to the base case analog in the array
i := 1
else
// Calling permutations(i+1, A) has ended as the while-loop terminated. Reset the state and simulate popping the stack by incrementing the pointer.
c[i] := 0
i += 1
end if
end while
Proof
In this proof, we'll use the below implementation as Heap's algorithm as it makes the analysis easier, and certain patterns can be easily illustrated. While it is not optimal (it does not minimize moves, which is described in the section below), the implementation is correct and will produce all permutations.
// Output the k! permutations of A in which the first k elements are permuted in all ways.
// To get all permutations of A, use k := length of A.
//
// If, k > length of A, will try to access A out of bounds.
// If k <= 0 there will be no output (empty array has no permutations)
procedure permutations(k : integer, A : array of any):
if k = 1 then
output(A)
else
for i := 0; i < k; i += 1 do
permutations(k - 1, A)
if k is even then
swap(A[i], A[k-1])
else
swap(A[0], A[k-1])
end if
end for
end if
Claim: If array A has length , then permutations(n, A) will result in either A being unchanged, if is odd, or, if is even, then A is rotated to the right by 1 (last element shifted in front of other elements).
Base: If array has length 1, then permutations(1, A) will output A and stop, so A is unchanged. Since 1 is odd, this is what was claimed, so the claim is true for arrays of length 1.
Induction: If the claim is true for arrays of length ≥ 1, then we show that the claim is true for arrays of length +1 (together with the base case this proves that the claim is true for arrays of all lengths). Since the claim depends on whether is odd or even, we prove each case separately.
If is odd, then, by the induction hypothesis, for an array A of length , permutations(l, A) will not change A, and for the claim to hold for arrays of length +1 (which is even), we need to show that permutations(l+1, A) rotates A to the right by 1 position. Doing permutations(l+1, A) will first do permutations(l, A) (leaving A unchanged since is odd) and then in each iteration of the for-loop, swap the elements in positions and (the last position) in A. The first swap puts element (the last element) in position 0, and element 0 in position . The next swap puts the element in position (where the previous iteration put original element 0) in position 1 and element 1 in position . In the final iteration, the swap puts element -1 is in position , and the element in position (where the previous iteration put original element -2) in position -1. To illustrate the above, look below for the case = 4.
1,2,3,4 ... original array
1,2,3,4 ... 1st iteration (permute subarray)
4,2,3,1 ... 1st iteration (swap 1st element into last position)
4,2,3,1 ... 2nd iteration (permute subarray)
4,1,3,2 ... 2nd iteration (swap 2nd element into last position)
4,1,3,2 ... 3rd iteration (permute subarray)
4,1,2,3 ... 3rd iteration (swap 3rd element into last position)
4,1,2,3 ... 4th iteration (permute subarray)
4,1,2,3 ... 4th iteration (swap 4th element into last position)
The altered array is a rotated version of the original
If is even, then, by the induction hypothesis, for an array A of length , permutations(l, A) rotates A to the right by 1 position, and for the claim to hold for arrays of length +1 (which is odd), we need to show that permutations(l+1, A) leaves A unchanged. Doing permutations(l+1, A) will in each iteration of the for-loop, first do permutations(l, A) (rotating the first elements of A by 1 position since is even) and then, swap the elements in positions 0 and (the last position) in A. Rotating the first elements and then swapping the first and last elements is equivalent to rotating the entire array. Since there are as many iterations of the loop as there are elements in the array, the entire array is rotated until each element returns to where it started. To illustrate the above, look below for the case = 5.
1,2,3,4,5 ... original array
4,1,2,3,5 ... 1st iteration (permute subarray, which rotates it)
5,1,2,3,4 ... 1st iteration (swap)
3,5,1,2,4 ... 2nd iteration (permute subarray, which rotates it)
4,5,1,2,3 ... 2nd iteration (swap)
2,4,5,1,3 ... 3rd iteration (permute subarray, which rotates it)
3,4,5,1,2 ... 3rd iteration (swap)
1,3,4,5,2 ... 4th iteration (permute subarray, which rotates it)
2,3,4,5,1 ... 4th iteration (swap)
5,2,3,4,1 ... 5th iteration (permute subarray, which rotates it)
1,2,3,4,5 ... 5th iteration (swap)
The final state of the array is in the same order as the original
The induction proof for the claim is now complete, which will now lead to why Heap's Algorithm creates all permutations of array . Once again we will prove by induction the correctness of Heap's Algorithm.
Basis: Heap's Algorithm trivially permutes an array of size as outputting is the one and only permutation of .
Induction: Assume Heap's Algorithm permutes an array of size . Using the results from the previous proof, every element of will be in the "buffer" once when the first elements are permuted. Because permutations of an array can be made by altering some array through the removal of an element from then tacking on to each permutation of the altered array, it follows that Heap's Algorithm permutes an array of size , for the "buffer" in essence holds the removed element, being tacked onto the permutations of the subarray of size . Because each iteration of Heap's Algorithm has a different element of occupying the buffer when the subarray is permuted, every permutation is generated as each element of has a chance to be tacked onto the permutations of the array without the buffer element.
Frequent mis-implementations
It is tempting to simplify the recursive version given above by reducing the instances of recursive calls. For example, as:
procedure permutations(k : integer, A : array of any):
if k = 1 then
output(A)
else
// Recursively call once for each k
for i := 0; i < k; i += 1 do
permutations(k - 1, A)
// swap choice dependent on parity of k (even or odd)
if k is even then
// no-op when i == k-1
swap(A[i], A[k-1])
else
// XXX incorrect additional swap when i==k-1
swap(A[0], A[k-1])
end if
end for
end if
This implementation will succeed in producing all permutations but does not minimize movement. As the recursive call-stacks unwind, it results in additional swaps at each level. Half of these will be no-ops of and where but when is odd, it results in additional swaps of the with the element.
These additional swaps significantly alter the order of the prefix elements.
The additional swaps can be avoided by either adding an additional recursive call before the loop and looping times (as above) or looping times and checking that is less than as in:
procedure permutations(k : integer, A : array of any):
if k = 1 then
output(A)
else
// Recursively call once for each k
for i := 0; i < k; i += 1 do
permutations(k - 1, A)
// avoid swap when i==k-1
if (i < k - 1)
// swap choice dependent on parity of k
if k is even then
swap(A[i], A[k-1])
else
swap(A[0], A[k-1])
end if
end if
end for
end if
The choice is primarily aesthetic but the latter results in checking the value of twice as often.
See also
Steinhaus–Johnson–Trotter algorithm
References
Combinatorial algorithms
Permutations | Heap's algorithm | [
"Mathematics"
] | 2,797 | [
"Combinatorial algorithms",
"Functions and mappings",
"Permutations",
"Mathematical objects",
"Computational mathematics",
"Combinatorics",
"Mathematical relations"
] |
41,437,935 | https://en.wikipedia.org/wiki/Fundamental%20theorem%20of%20algebraic%20K-theory | In algebra, the fundamental theorem of algebraic K-theory describes the effects of changing the ring of K-groups from a ring R to or . The theorem was first proved by Hyman Bass for and was later extended to higher K-groups by Daniel Quillen.
Description
Let be the algebraic K-theory of the category of finitely generated modules over a noetherian ring R; explicitly, we can take , where is given by Quillen's Q-construction. If R is a regular ring (i.e., has finite global dimension), then the i-th K-group of R. This is an immediate consequence of the resolution theorem, which compares the K-theories of two different categories (with inclusion relation.)
For a noetherian ring R, the fundamental theorem states:
(i) .
(ii) .
The proof of the theorem uses the Q-construction. There is also a version of the theorem for the singular case (for ); this is the version proved in Grayson's paper.
See also
Basic theorems in algebraic K-theory
Notes
References
Daniel Grayson, Higher algebraic K-theory II [after Daniel Quillen], 1976
Algebraic K-theory
Theorems in algebraic topology | Fundamental theorem of algebraic K-theory | [
"Mathematics"
] | 249 | [
"Algebra stubs",
"Theorems in algebraic topology",
"Algebra",
"Theorems in topology"
] |
41,438,927 | https://en.wikipedia.org/wiki/Decriminalization%20of%20sex%20work | The decriminalization of sex work is the removal of criminal penalties for sex work (specifically, prostitution). Sex work, the consensual provision of sexual services for money or goods, is criminalized in most countries. Decriminalization is distinct from legalization (also known as the "regulationist" approach).
Advocates of decriminalization argue that removing the criminal sanctions surrounding sex work creates a safer environment for sex workers, and that it helps fight sex trafficking. Opponents of decriminalization argue that it will not prevent trafficking (or even increase trafficking) and could put sex workers at greater risk. Evidence demonstrates that decriminalization is an evidence-based harm reduction approach.
Organizations including: the Joint United Nations Programme on HIV/AIDS (UNAIDS), the World Health Organization (WHO), Amnesty International, Human Rights Watch, United Nations Population Fund (UNFPA), and the medical journal The Lancet have called on countries to decriminalize sex work in the global effort to tackle the HIV/AIDS epidemic and ensure sex workers' access to health services. Almost all organisations run by sex workers themselves around the world favour the decriminalisation of sex work, and it tends to be their main goal.
However, a European Parliament resolution adopted on 26 February 2014, regarding sexual exploitation and prostitution and its impact on gender equality states that, "decriminalising the sex industry in general and making procuring legal is not a solution to keeping vulnerable women and under-age females safe from violence and exploitation, but has the opposite effect and puts them in danger of a higher level of violence, while at the same time encouraging prostitution markets – and thus the number of women and under-age females suffering abuse – to grow."
Two countries have decriminalized sex work. In June 2003, New Zealand became the first country to decriminalize sex work, with the passage of the Prostitution Reform Act. The one remaining criminal law surrounding commercial sexual activities in New Zealand is a requirement to adopt safer sex practices. Despite decriminalisation, its sex industry is still controversial, with some issues remaining. In June 2022, Belgium became the first country in Europe and the second country in the world to decriminalize sex work.
Legal models of sex work
There are a wide variety of legal approaches to regulating prostitution. NGOs, academics, and government agencies typically use five different models to organize the different approaches. Scholars have also used three-fold and four-fold classifications, and terminology may differ between studies. Some may equate the term "criminalisation" with "prohibition(ism)", while others regard all policies except "decriminalisation" as a certain degree of criminalisation.
Prohibitionism
Hindle et al. (2008) stated: "Prohibitionism seeks to eliminate prostitution by criminalizing all aspects of the prostitution trade. Under this approach, prostitution is seen as a violation of human dignity. Criminal law and effective law enforcement are viewed as critical tools in reducing the number of individuals involved in prostitution." Kulick (2003) stated that prohibitionist models "criminalise the actual transaction of selling sex." Scoular (2015) noted that those taking a prohibitionist approach believe that the sex trade is a violation of moral (usually religious) beliefs, and seek "to deter parties from engaging in prostitution by punishing one (usually the female sellers) or, increasingly, both parties."
Abolitionism
Hindle et al. (2008) stated: "Abolitionism is often described as the middle ground between prohibitionism and legalization. Advocates of this approach maintain that even though prostitutes may choose to enter the trade, it is nevertheless immoral. They believe that governments must take the necessary steps to allow prostitution to take place only as long as it does not infringe on public safety and order. Generally, abolitionists call for the criminalization of public solicitation." Kulick (2003) defined abolitionism as "a legal system that holds that prostitution in itself is not an offence, but the exploitation of the prostitution of others is; thus any third party recruiting, profiting from, or organising prostitutes is penalised."
Neo-abolitionism
Neo-abolitionism, also called the Nordic or Swedish model, is used in Sweden, Norway, France and other countries. While selling sex is not criminalized under this approach, the buying of sex is illegal. Neo-abolitionists claim these models do not punish prostitutes, but instead penalize those who purchase sex from sex workers. This model is criticized for causing sex workers to do their business in areas with less police, which often makes it more dangerous.
Legalization
Legalization is also referred to as "regulationist". In countries that legalize prostitution, it is no longer prohibited, and there is legislation to control and regulate it. The extent and type of legislation varies from country to country and may be regulated by work permits, licensing or tolerance zones.
Decriminalization
Decriminalization is the removal of criminal penalties for sex work. In countries that decriminalize sex work, sex workers receive the same protection and recognition as workers in other industries. The very first line of the World Charter for Prostitutes' Rights, written and adopted by the International Committee for Prostitutes' Rights on 15 February 1985 at the first World Whores Congress in Amsterdam, states: "Decriminalize all aspects of adult prostitution resulting from individual decision."
Effects of criminalization
Health
According to the World Health Organization (WHO), sex workers are considered one of the key populations at risk for HIV infection, and sex workers who inject drugs are at even more risk due to unprotected sex, syringe sharing, alcohol or drug dependence, and violence. Stigma, poverty, and exclusion from legal social services have increased their vulnerability to HIV infection. Health risks and transmission of HIV as well as other sexually transmitted infections (STIs) are increased in incidences where condom usage and accessibility is limited or used to identify and criminalize sex workers. Many sex workers are managed by 'gatekeepers' who may be brothel owners, clients, or law enforcement figures, who often dictate condom usage. In Cambodia, a survey showed that 30% of sex workers who refused to put on condoms were sexually coerced. Fear of law enforcement and incarceration also discourages possession of condoms since they provide evidence for officers to prosecute and arrest. Evidence suggests that HIV risk can be sharply reduced when sex workers are able to negotiate safer sex. Decriminalization of sex work decreases the risk of HIV infection by breaking down stigma and increasing access to health services, reducing the risk of HIV/AIDS and STIs.
According to a 2020 study, criminalisation of sex work in one district in East Java, compared to neighbouring districts where sex work was not criminalised, increased the rate of sexually transmitted infections among female sex workers by 58%, made their income after leaving sex work lower on average, and their children more likely to begin working to supplement household income rather than go to school (as school expenses were harder to meet). A 2018 study found that the 2003–2009 decriminalization of indoor prostitution in Rhode Island led to reduced sexually transmitted infections (female gonorrhoea incidence declined by over 40%) and fewer rapes (reported rape offences fell by 30%). A 2017 study found that the introduction of legal prostitution zones in the Netherlands substantially reduced drug-related crime, sexual abuse and rape (the latter two by 30–40% in the first two years).
Violence
According to a 2021 study, the openings of adult entertainment establishments (strip clubs, gentlemen clubs and escort girl services) in New York City were associated with a 13% decrease in sex crime one week after the opening (while having no impact on other forms of crime). The evidence suggests that potential sex offenders frequent such establishments rather than commit sex crimes.
Discrimination and stigma
Sex workers experience significant stigma and discrimination as a result of criminalization. Though they consider sex work a legitimate income-generating activity, sex workers are viewed as immoral, deserving of punishment, and thus excluded from healthcare, education, and housing. Criminalization laws exclude sex workers from health systems that provide access to preventative care such as condoms and regular HIV or STI testing.
Human rights abuses
Sex workers, as a population that suffers disproportionately from HIV/AIDS, are often denied many human rights such as the right to freedom from discrimination, equality before the law, the right to life, and the right to the highest attainable standard of health. A study conducted in more than 11 countries by Sex Workers' Rights Advocacy Network (SWAN) concluded that more than 200 sex workers have experienced violence and discrimination. These acts of violence toward sex workers often include abuse, rape, kidnappings, and sexual violence. Sex workers also face extortion and unlawful arrests and detention, which profoundly impact their mental, physical, and social wellbeing. It is difficult for sex workers to seek criminal justice when it is reported that many police officers are partaking in the sexual and violent abuse. In North Macedonia, police sexual assault towards sex workers is particularly high: 82.4 percent of sex workers were assaulted by police in 2007. Criminalization also forces sex workers to work in unsafe settings to avoid police detection which increases their risk of being forced of coerced into sex trafficking. Criminalization laws such as bans on buying, solicitation, and the general organization of sex work perpetuate an unsafe environment for sex workers, provide impunity for abusers, and prevent sex workers from reporting the crime to the police.
Poverty
In countries where sex work is a crime, encounters with law enforcement and the judicial system can cause great financial difficulty for sex workers. Frequent arrests and legal fines may accumulate over time, and because a fair share of sex workers come from impoverished backgrounds anyway, the toll can be immense. In Washington, D.C., for example, a sex worker's first offense will result in a fine for as much as $500. The financial impact can then magnify over time after an encounter with law enforcement. Having a sex work offense on their record may complicate or completely prevent sex workers from acquiring housing. If a sex worker with a criminal record seeks employment in another industry, they may face discrimination or be disallowed from applying. 55% of Black trans sex workers who participated in a 2015 survey reported being unemployed, while 40% of trans sex workers had experienced gender discrimination when seeking employment.
Specific populations
Male sex workers
Over the course of the past several decades, the demand for male sex work has risen dramatically as people's opinions on not just homosexuality but prostitution as well have begun to change to look at both in a more favorable light. As society's opinions on homosexuality and prostitution have changed in different parts of the world, there has been a subsequent push for the changing of the laws and regulations regarding these matters in some countries, which have helped to increase the demand for male sex work around the world.
The demand for the decriminalization of sex work has also increased. Organizations like the Sex Workers Project, the Sex Workers Outreach Project, the International Committee on the Rights of Sex Workers in Europe, the Asia Pacific Network of Sex Workers, and the African Sex Workers Alliance all work internationally to fight for the rights of both male and female sex workers and for the decriminalization of sex work as whole. This reflects how much the atmosphere surrounding the decriminalization of sex work has changed in the past several decades, as none of the organizations listed above existed before the 1990s.
Similarly to female sex work, there is a long history of discrimination against male sex work, but for different reasons. Much of the sentiment against male sex workers has come from its association with homosexuality, which for much of history was not socially acceptable. Much of this anti-homosexual sentiment stems from the fact that traditionally the three major Abrahamic religions (Judaism, Christianity, and Islam) taught that homosexuality was sinful, citing Leviticus 18:22 where it states, "You shall not lie with a male as with a woman; it is an abomination" as the main reasoning for this belief. As a result, homosexuality was made illegal in many societies, and punishments were put in place for homosexual behavior.
Anti-homosexual sentiment still exists in some parts of the world. In some places, it is still illegal and punishable by death to be gay. For example, in countries like Yemen, Iran, Saudi Arabia, Mauritania, Nigeria, Brunei, Qatar, Pakistan, Sudan, United Arab Emirates, Somalia, and Afghanistan being homosexual is still punishable by death. In other countries, it is not punishable by death but is still illegal and is punishable in other ways. Punishment in these countries can range, 0–10 years, 10–life, and lashes/corporal punishment. Therefore, in many of these countries male sex workers work in unsafe conditions where they run a higher risk of experiencing violence, or sexual abuse to avoid detection by the police who are sometimes the proponents of this violence. Another issue associated with working in these unsafe conditions is the risk of contracting an STI or HIV is much higher.
There has been a push in the past several decades for the decriminalization of sex work in general and more specifically male sex work. The success of some of these movement in achieving the decriminalization and in some cases even legalization of sex work has increase the demand for male sex workers worldwide. Even in countries where neither legalization nor even full decriminalization has been achieved, these movements have at least been successful in relaxing the regulations regarding sex work in general and more specifically male sex work. Which as a result of the relaxing of these regulations even where unsuccessful in achieving full decriminalization, there has been a general increase in the demand for sex work and thereby male sex workers. The advent of the internet has also only worked to further increase the demand for male sex work as not only has it allowed male sex workers to connect with their clients more easily, but it has also allowed them to do so more discreetly, which is important in countries where prostitution is still illegal and for clients who want to keep their business private.
There are a number of organizations internationally who fight for the rights of sex workers and the decriminalization of prostitution which just to mention a few include the Sex Workers Project, the International Committee on the Rights of Sex Workers in Europe, and the African Sex Workers Alliance. These organizations serve as the leaders in the fight for the decriminalization of sex work as they use the power of their numbers to help them influence policy makes. Which leads to the argument for the decriminalization of male sex work. The argument for the decriminalization of male sex work shares many of the same key points as the arguments for the decriminalization of female sex work. With the main argument for the decriminalization of male sex work and sex work in general being that it is in the best interest of the public health to decriminalize sex work, to ensure that sex workers are capable of going through more professional channels to do their work. Allowing sex workers to use more professional channels in their work would allow them to more easily access protection, get tested for STIs and HIV, and enforce that their clients wear protection and be tested.
STIs and HIV are major issues in the field of male sex work, with some studies finding that up to 50% of male sex workers tested positive for HIV in some regions, many of whom were completely unaware. The rates of STIs and HIV amongst male sex workers varies wildly based on income level, race, and sexual preference. This a prime example of an area that would become more equitable to male sex workers of all income levels, races, and sexual preferences, if male sex and sex work in general were to be decriminalized and could only improve even further with full legalization. In general the rates of HIV were highest amongst male sex workers who identified as gay, and it is suggested that this may be partially the result of a lack of education regarding the need and importance of still using protection when engaging in gay sex. It has also been suggested that male sex workers may be unable to enforce that their clients use condoms due to the risk of experiencing violence for refusing to engage in condomless sex. These would both be less of an issue if male sex work and sex work in general were to be decriminalized, as it would allow them to go about their work in more professional settings that would greatly reduce the risk of them experiencing violence or contracting STIs and HIV.
Transgender sex workers
Transgender sex workers experience a disproportionate amount of discrimination and violence, and many activist groups advocate for decriminalization of sex work because it would greatly benefit transgender individuals in the industry. For example, the National Center for Transgender Equality expressed its support for the Amnesty International resolution in support of decriminalizing sex work on the basis of its goal to protect the human rights of workers in the sex industry.
One study of transgender sex workers that examined their reasons for involving themselves in the industry found that many transgender female sex workers experienced worry that they would not be hired by other employers because of their gender identity. Therefore, they sought work in the sex industry because they felt it was their only choice. However, many transgender female sex workers express satisfaction with their occupation because their clients approach them as "real females", and they experience less gender discrimination than they do in their daily lives. Many advocates view this sort of positive experience as evidence supporting the need to decriminalize sex work. In various qualitative studies, interviews with transgender female sex workers revealed their experience with policing and law enforcement, and numerous reported believing that their gender identity combined with their job in the sex industry resulted in discriminatory treatment from law enforcement, including verbal and physical abuse. The criminalization of sex work also imposes a unique risk to transgender sex workers because, if arrested and incarcerated, they experience highly disproportionate levels of physical and sexual violence at the hands of cisgender male prisoners in the facilities where they are required to be housed.
Practical comparison
This section compares some examples of various legal models in practice.
Abolitionist practice
Brazil
Brazil operates within the abolitionist model of sex work. This means that selling sex in exchange for money is legal, and sex workers can even claim pensions and benefits when employed in the industry. However, it is illegal to employ sex workers or to profit off the work of a sex worker. In practice, this means that brothels and pimps are criminalized as is sex trafficking. Despite selling and buying sex being legal (only when occurring between sex workers and their clients), there are still many laws and regulations that limit those working in the sex industry. For example, sex workers in Brazil are often charged with vagrancy, loitering, or public disorder when law enforcement sees them soliciting clients. In Rio de Jainero specifically, legal authorities set up campaigns to dissuade sex tourism, and many individuals known to be promoting prostitution have been arrested.
Neo-abolitionist (Nordic) practice
Canada
In 2013, a study was conducted in Vancouver, where purchasing sex was enforced by the Vancouver Police Department as illegal but selling it was not. The study found that while the introduction of this policy did improve relations between sex workers and the police, it also "reproduce[d] the harms created by the criminalisation of sex work, in particular, vulnerability to violence and HIV/STIs".
Canada's prostitution law was challenged in 2013 by Terri-Jean Bedford, Amy Lebovitch, and Valerie Scott in the Bedford v. Canada case. The plaintiffs argued that the criminal laws disproportionately increased their risk of violence and victimization by preventing them from being able to employ safety strategies during the course of their work. In a 9–0 ruling, the Supreme Court of Canada determined that the communication provision, the bawdy house provision, and the living on the avails provision violated sex workers' rights to security of the persons. To give the Government of Canada time to respond, the declaration of invalidity was suspended for one year.
In 2014, the Government of Canada enacted the Protection of Communities and Exploited Persons Act (PCEPA). This legislation is modelled after the Nordic Model, and criminalizes buyers of sexual services as well as third-party supporters (brothel ownership and pimping are also illegal). Most Canadian sex workers' rights groups rejected the Nordic model, because it was deemed to be "harmful and inconsistent with sex workers' constitutional rights to health and safety", according to the Canadian Alliance for Sex Work Law Reform (CASWLR). Instead, they favoured New Zealand's model of decriminalisation, because it supposedly 'decreased violence against sex workers and increased police protection while improving employment conditions, including protection from harassment by the sex worker's employer'. In February 2020, an Ontario court judge struck down three parts of the PCEPA as unconstitutional: the prohibitions on advertising, procuring and materially benefiting from someone else's sexual services were violations of the 'freedom of expression' and 'security of the person' as defined in the Canadian Charter of Rights and Freedoms. If upheld, this would allow third-party involvement, which sex workers said would provide them important protections, but Christian anti-trafficking activists claimed would facilitate sex trafficking.
France
In 2016, the French federal government estimated that there were around 30,000 prostitutes in the country, and 93% of them were foreign. In April 2016, the French National Assembly passed a law that partially decriminalized sex work. While selling sex, loitering, and public soliciting by prostitutes is now legal, paying for sex carries a fine of around 1,500 euros. People found guilty of paying for sex may also have to complete an "awareness-raising course on the fight against the purchase of sexual acts".
The French government also attempted to fight prostitution by providing compensation to sex workers who wanted to leave the sex industry. However, although the government hoped to help 600 prostitutes by 2018, only 55 sex workers signed up for the program. Some sex workers argue that the monthly stipend, which is 330 euros, is not enough money to make ends meet.
The 2016 law has also resulted in increased violence against sex workers. Because of the heightened police presence, the sex work that does happen has been pushed off the streets and into areas with limited surveillance. This has created more dangerous conditions for prostitutes that continue to work. According to a survey conducted by the French NGO Médecins du Monde, 42% of percent of prostitutes in France say that they have been exposed to more violence since the law took effect in 2016.
Sweden
Sweden passed a law in 1999 which criminalised buying sex, while maintaining that selling sex is legal. Kulick (2003) and Matthews (2008) have labelled this Swedish law 'prohibitionist' (with Kulick arguing Sweden was 'abolitionist' before 1999), while Niklas Jakobsson & Andreas Kotsadam (2010) called it 'neo-abolitionist'. Since the implementation of the law, supporters of this approach have claimed the number of prostitutes has decreased. However, this may just be a result of the increased police surveillance, as many sex workers are leaving the streets and turning instead to other spaces, including the internet.
Pye Jakobsson, a spokeswoman for the Rose Alliance which represents sex workers, believes that this reduction in numbers of street workers may not necessarily mean less prostitution, pointing to the 50% of sex workers who work indoors. Jakobsson claims that "you can't talk about protecting sex workers as well as saying the law is good, because it's driving prostitution and trafficking underground, which reduces social services' access to victims."
In a 2010 review, the Swedish government agreed with Swedish sex workers that this model has increased stigma against sex workers. However, the Swedish government viewed this as a positive outcome, arguing that sending a message about sex work is more important.
Sex workers have reported a number of human rights violations as a direct result of these laws, including the deportation of sex workers, increased evictions, increased vulnerability to homelessness, and high rates of discrimination from authorities. The 1999 law has also led to sex workers being used as witnesses by the police in cases that they did not want to be a part of. In addition, because police oftentimes use condoms as evidence in these cases, condom use has gone down among Swedish sex workers and customers. By 2021, the Christian anti-prostitution and anti-pornography NGO Talita reportedly had major influence in the public debate about sex work, as it was frequently cited in news and opinion articles in Swedish media, which tended to focus on the alleged harmful aspects. Swedish sex workers think that Talita and the media used "overly negative wordings", and attempts to incorrectly link all sex work to human trafficking only increased stigmatisation. Workers have argued that "it would be better to hold a realistic discussion about the pros and cons, instead demonising it as a whole."
Legalisation (regulationist) practice
Denmark
In Denmark, prostitution was legalised in 1999, allowing for both selling and buying of sex to be legal as long as both participants are above the age of 18. Brothels and pimping, however, still remain illegal in the country. Previously, sex workers were permitted to work as long as it was not their only source of income.
Germany
Germany legalized sex work in 2002. The 2002 law mandated that sex workers register themselves and pay taxes. In return, their employers would have to provide benefits like health care and paid leave. In addition, customers of sex workers are not allowed to deny payment because they "aren't satisfied". After the law was put in place, the German sex industry boomed. According to 2005 estimates by the German federal government, there are about 400,000 sex workers in Germany, and over 1.2 million men pay for their services every day.
The implementation of the law was flawed because of a lack of outreach and training. As a result, the law was interpreted differently in different cities. In Berlin, the law was interpreted in ways that are favorable to sex workers; in Cologne, a "pleasure tax" that only applies to sex work was imposed.
A 2014 article in The Daily Telegraph claimed that, while this law was designed to protect the rights of sex workers and recognise their occupation as a job like any other, it has instead resulted in massive, multi-story brothels and the introduction of roadside "sex boxes" (German: Verrichtungsboxen).
Netherlands
The Netherlands lifted the 1911 brothel ban in 2000, earning its international status as a symbol of a 'liberal' approach to sex work. The Dutch legalisation model was contrasted with the neo-abolitionist model introduced by Sweden in 1999. According to Heumann et al. (2017), the 1911 brothel ban was vaguely formulated, poorly enforced, and sex workers themselves were not criminalised, but despite this pre-2000 'regulated tolerance' (Dutch: gedoogbeleid), they were still stigmatised as 'fallen' or 'sinful' women, or 'psychiatrically disturbed'. Feminists (concerned about women's rights and oppression) and conservatives (concerned about public order, 'morality' and women's 'dignity') reached a rough agreement in the 1980s to legalise sex work while countering sex trafficking. However, the Repeal Bill (to lift the 1911 brothel ban) and Trafficking Bill proposed together in 1987 and passed by Parliament were put on hold in the Senate, and finally blocked in 1989 by the new fervent abolitionist Justice Minister Ernst Hirsch Ballin (Christian Democrats). He heavily revised both bills to the effect that all migrant women were considered trafficking victims; these proposals were strongly opposed by the Senate in 1992. Eventually a thoroughly altered version of the Trafficking Bill was approved in 1993, while the Repeal Bill was postponed indefinitely. The Repeal Bill was taken up again in 1997 by the first secular government coalition of the Netherlands, involving social democrats (PvdA), conservative liberals (VVD) and progressive liberals (D66), who agreed on lifting the ban in 1999, which went into effect in 2000. The theory behind the government's legalisation was harm reduction, to increase the visibility of criminal activities and to fight trafficking, and overall better governmental control over prostitution. Notably, migrant sex workers without a residence permit were not allowed to work legally. After 2000, certain interpretations of the law and further local legal restrictions introduced various neo-abolitionist elements into the Dutch situation, pushing especially migrant sex workers into illegality. Moreover, sex workers' rights including labour rights were pushed to the background and undermined, either by the government by invoking 'protection', or by the major brothel companies, who were the only ones capable of complying to the strict licensing requirements and paying for them, and capable of using lawyers to evade taxes and undermine the rights of sex workers.
Nevada, United States
Nevada is the only state in the United States in which prostitution is legal, although only in 10 rural counties and only in licensed houses.
There was no state law on prostitution in Nevada until 1971, when a section of the Nevada Revised Statutes effectively legalized prostitution in counties with a population of under 400,000. In the mid-1970s, a man named Walter Plankinton attempted to open a brothel in Nye County, Nevada. County officials initially blocked him from opening the brothel (which he planned to call "The Chicken Ranch"), citing a 1948 state law that called brothels a "nuisance". However, this law was overturned by the Nevada Supreme Court in 1978. In 1980, the Nevada Supreme Court officially legalized prostitution in counties with a population of under 400,000. However, prostitution outside of a "licensed house of prostitution" was not banned until 1987, when the Nevada Revised Statutes made it explicitly illegal.
Sex work in Nevada is regulated in the ten counties and five cities that permit it. Prostitutes are regulated by a patchwork of both state and local laws that address a number of different areas. Zoning laws in Nevada prohibit brothels from being located near a school, house of worship, or main road. Brothels are also barred from advertising on public roads or in districts where prostitution is illegal. The county licenses for brothels are very expensive, to the point of being a significant item in county revenue. Other existing regulations mandate STI testing before prostitutes are hired, and weekly testing once they are employed. Sex workers with HIV are also prohibited from working. Sex workers who continue to work after testing HIV-positive can be punished with two to ten years in prison or a $10,000 fine.
Decriminalisation practice
Belgium
In March 2022, Belgium moved to become the first European country to decriminalise sex work.
On 17 March 2022, the Chamber of Representatives of Belgium approved a sexual crimes legislation reform bill, developed under the responsibility of Justice Minister Vincent Van Quickenborne. The reform bill inter alia envisioned a phased decriminalisation of sex work for adults (18 years or older). In the first step, sex work was only legally allowed for self-employed sex workers where they would only be permitted to advertise their own sexual services via designated types of media. This law came into effect on 1 June 2022.
Starting 1 December 2024, Belgium’s amended labour law decriminalised sex work under official employment contract, becoming the first in the world to do so. Sex workers working for an employer enjoy all social benefits also enjoyed by other workers, such as maternity leave and state pensions, but also have special protections not found in other sectors, such as requiring employers install a panic button and employees being able to quit without notice.
South Africa
In November 2022, the Cabinet of South Africa has approved a bill for decriminalizing sex work. The bill has not yet been written into law and once published in the Gazette will be open to the public to comment.
Australia
Laws covering sex work in Australia are state and territory based, with different regulations in different places. New South Wales, which includes the city of Sydney, decriminalised sex work in 1995 after the Wood Royal Commission showed that police were inappropriate regulators of the sex industry, because criminalisation led to police corruption, great health risks to sex workers and the community, as well as public nuisance.
New South Wales towards prohibition 1908–1976
New South Wales amended the Police Offences Act in 1908 to criminalise men, but not women, who lived off the earnings of prostitution, so that male brothel owners henceforth risked prosecution. The 1924 amendments to the Crimes Act increased these penalties, while police were given more power over the movement of prostitutes; the latter were more exposed to police arrest and violence from clients by these legal restrictions on their male associates. Combined with the criminalisation of gambling and newly introduced drugs, criminal gangs emerged in Sydney, which waged "razor wars" in the streets for the control of all these profitable illegal activities. Changes to the law in 1929 gave the police more power to combat the criminal gangs, who were quickly crushed, but replaced by corrupt police control. By the 1960s, the police corruption over prostitution in Sydney had solidified, and sex workers had to pay regular bribes (called "weighing-in") to the two police branches in the area. Nevertheless, sex workers could still be arrested by the police and be convicted for various prostitution-related offences such as soliciting, consorting, and 'offensive behaviour'. The arrival of American troops from the Vietnam War from 1966 and onwards quickly stimulated the rise of drug- and prostitution-related violent rival criminal syndicates which collaborated with the corrupt police. The conservative Askin Government (Liberal Party) further criminalised sex work in 1968 by introducing extra offences, increasing penalties, and also making it a crime for women to live off the earnings of prostitution; as a result, police bribes and arrests increased, and sex workers were driven further underground.
New South Wales partial decriminalisation and re-criminalisation 1976–1995
When the progressive Wran Government (Labor Party) took office in 1976, libertarians – arguing the state should not interfere with private sexual acts between consenting adults – and feminists – arguing the law discriminated against women, because women selling sex were criminalised, but men buying sex were not – pushed for decriminalisation of most aspects of prostitution, except when it caused public nuisance or involved exploitation. The 1979 legal amendments decriminalised public soliciting and for sex workers to be found on premises used for prostitution, while brothel-keeping was still criminal per the Disorderly Houses Act, and advertising and selling sexual services under the guise of other services such as massage were criminalised; as a result, street prostitution boomed. The police campaigned against these reductions of their authority, while local communities pressured the government for better city planning to avoid public nuisance created by prostitution (the latter caused legal amendments in 1983 prohibiting soliciting near schools, churches, hospitals and dwellings). The new conservative Greiner Government (Liberal Party) taking office in 1988 reversed some Labor policies with the new Summary Offences Act, which increased penalties for all prostitution-related offences and also criminalised customers – although few men have been charged; police corruption increased once again.
New South Wales decriminalisation 1995–present
The new Carr Government (Labor Party) appointed Justice James Roland Wood to lead the Royal Commission into the New South Wales Police Service (1995–1997) to deal with, amongst other things, the police corruption relating to sex work in the state. The Commission concluded that the Disorderly Houses Act enabled police corruption, and because the lack of secure brothels forced many sex workers into the streets, posing greater health risks to themselves and the community, the Commission concluded it was better to enable safe brothels for sex workers. The Government acted upon its findings by amending the Disorderly Houses Act in 1995, making brothels normal businesses requiring no special licence or registration. Brothels could now only be shut down by a formal complaint to the Land and Environment Court, taking away the power of the police to shut down, or threaten to shut down, any brothel as a 'disorderly house', which had been an importance cause of the police corruption. The 1995 amendments also allowed third parties to work with prostitutes again. Thus, New South Wales decriminalised sex work in 1995. A governmental review in 2016 resulted in continuing "support of decriminalisation of sex work as the best way of protecting sex workers and maintaining a more transparent sex work industry".
Northern Territory decriminalisation 2019
Victoria decriminalisation 2022–2023
In February 2022, Victoria passed legislation to decriminalise sex work. "The Sex Work Decriminalisation Act 2021 will partially abolish street-based sex work offences and associated public health offences, remove the licensing system and move to regulate the industry through existing agencies." From 1 December 2023, a sex services business will be able to operate exactly the same way as any other business in Victoria.
New Zealand
New Zealand became the first country to decriminalize prostitution in June 2003 with the passage of the Prostitution Reform Act 2003. The purpose of this law was to "decriminalise prostitution (while not endorsing or morally sanctioning prostitution or its use); create a framework to safeguard the human rights of sex workers and protect them from exploitation; promote the welfare and occupational health and safety of sex workers; contribute to public health; and prohibit the use of prostitution of persons under 18 years of age." The PRA also established a certification regime for brothel operators".
Catherine Healy, the national coordinator of the New Zealand Prostitutes' Collective (NZPC), who was part of the driving force for the original 2003 law, in an interview twelve years later, had "detected a marked change in police-sex worker relations after passage of the PRA. 'After decriminalization that dynamic shifted dramatically, and importantly the focus on the sex worker wasn't on the sex worker as a criminal. It was on the rights, safety, health and well being of the sex worker. Further, "sex workers in New Zealand are beginning to assert their rights now that the stigma associated with sex work has begun to decrease" as demonstrated by a sex worker successfully prosecuting a brothel owner for sexual harassment by her employer.
United States
Washtenaw County, Michigan
On 14 January 2021, Prosecutor Eli Savit of Washtenaw County, Michigan County Prosecutor's Office announced his office would no longer prosecute consensual sex work. The change applies to both sex workers and those seeking to buy sex. In their publicly released policy directive, the office outlined the justification for such change. First, they said, criminalizing sex work is antithetical to Constitutional principles of bodily autonomy and personal liberty. They also emphasized that prohibitionist policies generally result in exploitation and noted that criminalization often causes sex workers to operate in more dangerous environments where they are more likely to be victimized. The Prosecutor's Office also mentioned the negative health effects of criminalization, as well as the disproportionate negative effect of prohibition on transgender sex workers and those from racial and ethnic minorities. Finally, they noted that working in the sex industry is often not an individual's first choice, and the criminal charges they potentially face make it more difficult to seek work in other industries. The policy directive makes special mention of the criminality of instances where a client refuses to use a condom despite the sex worker asking and when a buyer does not pay a sex worker with whom they have engaged in sexual activity. The policy specifies that "pimps" still face criminal charges, but the victims of trafficking do not. Washtenaw thus became the first county in the United States to decriminalise sex work, and the first outside Nevada to legally allow sex work, with Oakland County Chief Assistant Prosecutor David Williams indicating he wanted to follow Washtenaw's example.
Montpelier, Vermont
On 22 June 2022, the city council of Montpelier, Vermont pushed for the decriminalization of sex work and the repeal of a local ordinance that prohibits prostitution. On 24 August 2022, Montpelier repealed its prostitution ordinance and is the second city in Vermont to do so.
See also
Bodily integrity
Liberty
List of sex worker organizations
Prostitution law
Revolting Prostitutes
Right to sexuality
Sex workers' rights
Sex-positive feminism
Sex-positive movement
References
Works cited
Further reading
Legal prostitution zones reduce incidents of rape and sexual abuse. HuffPost. Author - Alison Bass. Published 14 March 2017. Updated 7 April 2017.
External links
The laws that sex workers really want. TED (conference) (website). Alternate YouTube link. Published January 2016 on ted.com and June 2016 on YouTube.
Prostitution
Human sexuality
Sex industry | Decriminalization of sex work | [
"Biology"
] | 8,363 | [
"Human sexuality",
"Behavior",
"Human behavior",
"Sexuality"
] |
41,439,747 | https://en.wikipedia.org/wiki/Pseudohypoxia | Pseudohypoxia refers to a condition that mimics hypoxia, by having sufficient oxygen yet impaired mitochondrial respiration due to a deficiency of necessary co-enzymes, such as NAD+ and TPP. The increased cytosolic ratio of free NADH/NAD+ in cells (more NADH than NAD+) can be caused by diabetic hyperglycemia and by excessive alcohol consumption. Low levels of TPP results from thiamine deficiency.
The insufficiency of available NAD+ or TPP produces symptoms similar to hypoxia (lack of oxygen), because they are needed primarily by the Krebs cycle for oxidative phosphorylation, and NAD+ to a lesser extent in anaerobic glycolysis. Oxidative phosphorylation and glyocolysis are vital as these metabolic pathways produce ATP, which is the molecule that releases energy necessary for cells to function.
As there is not enough NAD+ or TPP for aerobic glycolysis nor fatty acid oxidation, anaerobic glycolysis is excessively used which turns glycogen and glucose into pyruvate, and then the pyruvate into lactate (fermentation). Fermentation also generates a small amount of NAD+ from NADH, but only enough to keep anaerobic glycolysis going. The excessive use of anaerobic glycolysis disrupts the lactate/pyruvate ratio causing lactic acidosis. The decreased pyruvate inhibits gluconeogenesis and increases release of fatty acids from adipose tissue. In the liver, the increase of plasma free fatty acids results in increased ketone production (which in excess causes ketoacidosis). The increased plasma free fatty acids, increased acetyl-CoA (accumulating from reduced Krebs cycle function), and increased NADH all contribute to increased fatty acid synthesis within the liver (which in excess causes fatty liver disease).
Pseudohypoxia also leads to hyperuricemia as elevated lactic acid inhibits uric acid secretion by the kidney; as well as the energy shortage from inhibited oxidative phosphorylation leads to increased turnover of adenosine nucleotides by the myokinase reaction and purine nucleotide cycle.
Research has shown that declining levels of NAD+ during aging cause pseudohypoxia, and that raising nuclear NAD+ in old mice reverses pseudohypoxia and metabolic dysfunction, thus reversing the aging process. It is expected that human NAD trials will begin in 2014.
Pseudohypoxia is a feature commonly noted in poorly-controlled diabetes.
Reactions
In poorly controlled diabetes, as insulin is insufficient, glucose cannot enter the cell and remains high in the blood (hyperglycemia). The polyol pathway converts glucose into fructose, which can then enter the cell without requiring insulin. The oxidative damage done to cells in diabetes damages DNA and causes poly (ADP ribose) polymerases or PARPs to be activated, such as PARP1. Both processes reduce the available NAD+.
In ethanol catabolism, ethanol is converted into acetate, consuming NAD+. When alcohol is consumed in small quantities, the NADH/NAD+ ratio remains in balance enough for the acetyl-CoA (converted from acetate) to be used for oxidative phosphorylation. However, even moderate amounts of alcohol (1-2 drinks) results in more NADH than NAD+, which inhibits oxidative phosphorylation. In chronic excessive alcohol consumption, the microsomal ethanol oxidizing system (MEOS) is used in addition to alcohol dehydrogenase.
Diabetes
Polyol pathway
D-glucose + NADPH → Sorbitol + NADP+ (catalyzed by aldose reductase)
Sorbitol + NAD+ → D-fructose + NADH (catalyzed by sorbitol dehydrogenase)
Poly (ADP-ribose) polymerase-1
Protein + NAD+ → Protein + ADP-ribose + nicotinamide (catalyzed by PARP1)
Ethanol catabolism
Alcohol dehydrogenase
Ethanol + NAD+ → Acetaldehyde + NADH + H+ (catalyzed by alcohol dehydrogenase)
Acetaldehyde + NAD+ → Acetate + NADH + H+ (catalyzed by aldehyde dehydrogenase)
MEOS
Ethanol + NADPH + H+ + O2 → Acetaldehyde + NADP+ + 2H2O (catalyzed by CYP2E1)
Acetaldehyde + NAD+ → Acetate + NADH + H+ (catalyzed by aldehyde dehydrogenase)
See also
Hypoxia (medical)
Hypoxia (disambiguation) - list under Hypoxia (medical) e.g. Intrauterine hypoxia
Bioenergetic systems - metabolic pathways of producing ATP
Metabolic acidosis
References
Cell biology
Medical signs
Geriatrics
Senescence | Pseudohypoxia | [
"Chemistry",
"Biology"
] | 1,075 | [
"Senescence",
"Cell biology",
"Metabolism",
"Cellular processes"
] |
53,027,734 | https://en.wikipedia.org/wiki/K.%20S.%20Babu | Kaladi S. Babu is a theoretical physicist, regents professor and interim head of the Department of Physics at Oklahoma State University. He received his PhD in 1986 from the University of Hawaii, under the supervision of Ernest Ma.
Awards
Babu is a Fellow of the American Physical Society and holds a Regents Professorship at Oklahoma State. He is one of three theoretical physicists named as a 2017 Distinguished Scholar by the Fermi National Accelerator Laboratory, or Fermilab, the largest particle accelerator facility in the United States.
Interests
Babu's research interests are primarily in the model-building and phenomenological aspects of physics beyond the Standard Model. He has been involved in studies of grand unified theories and nucleon decay.
Babu is a key member of the neutrino theory community, having proposed several testable models of neutrino masses. His 1988 paper on two-loop generation of neutrino masses (the so-called Zee–Babu model) provides an alternative to high scale seesaw mechanism, and is well cited in the literature. He and Ed Kearns convened the Baryon Number Violation subgroup of the "Snowmass" 2013 Community Planning Study. He has helped organize the Center for Theoretical Underground Physics (CETUP) series of international conferences on neutrino physics in Lead, South Dakota.
Publications
Babu has written over 200 scientific articles, which have received over 12,500 citations (excluding the biennial PDG Review of Particle Physics). His "Renowned" publications include a 1988 paper on Majorana neutrino masses and a 2002 paper on -symmetric neutrino masses.
References
External links
homepage at Oklahoma State
Publication profile on INSPIRE-HEP
Interview with South Dakota Public Broadcasting
Indian theoretical physicists
Particle physicists
Fellows of the American Physical Society
Living people
People associated with Fermilab
Year of birth missing (living people) | K. S. Babu | [
"Physics"
] | 371 | [
"Particle physicists",
"Particle physics"
] |
53,028,511 | https://en.wikipedia.org/wiki/HD%2036780 | HD 36780 is a star located in Orion's belt, within the equatorial constellation of Orion. It has an orange hue and is dimly visible to the naked eye with an apparent visual magnitude of +5.92. The distance to this object is approximately 534 light years based on parallax. It is drifting away from the Sun with a radial velocity of 84 km/s, having come to within some 2.1 million years ago.
This is an aging giant star with a stellar classification of K4 III. After exhausting the supply of hydrogen at its core, the star cooled and expanded off the main sequence. At present it has around 31 times the girth of the Sun. It is radiating 243 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,108 K.
References
K-type giants
Orion (constellation)
Durchmusterung objects
036780
026108
1874 | HD 36780 | [
"Astronomy"
] | 195 | [
"Constellations",
"Orion (constellation)"
] |
53,030,147 | https://en.wikipedia.org/wiki/Gerodiversity | Gerodiversity is the multicultural approach to issues of aging. This approach provides a theoretical foundation for the medical and psychological treatment of older adults within an ecological context that includes their cultural identity and heritage, social environment, community, family system, and significant relationships. Gerodiversity encompasses a social justice framework, which considers the social and historical dynamics of privilege and inequality. In addition to issues of aging, gerodiversity includes race, ethnicity, language, gender identity, socioeconomic status, physical ability or disability, sexual orientation, level of education, country of origin, location of residence, and religion or spirituality.
Gerodiversity builds on the field of clinical geropsychology, which applies psychological and developmental methods to understanding the behavioral, emotional, cognitive, and biological aspects of aging in the context of providing clinical care to older adults. The goal is to develop culturally competent, scientific methods for the psychological and medical treatment of the aging population. According to this perspective, in order to ethically and scientifically provide optimal care to older adults, clinicians must be aware of the cultural factors in health care utilization, including use of physical and mental health care. Moreover, from this perspective, clinicians must continually work to improve their multicultural knowledge base, skill set, and attitudes towards cultural diversity.
Demographics and characteristics to consider in geriatric populations
Increased awareness and attention to gerodiversity parallels the aging demography of the United States. Older adults comprise 14.5% of the U.S. population, with those aged 65 and older numbering 46.2 million. Dubbed "the Silver Tsunami", this segment of the population is rapidly growing, and the Administration on Aging expects it to double to 98 million older persons by 2060. Aging confers a unique risk of marginalization due to the intersection of advanced age and other disadvantaged factors. The domains of diversity discussed herein may intersect with age in such a way to confer a "double jeopardy". More recently, attention has been paid to those who face a "triple threat of marginalization" (e.g., older lesbian women). As with other conceptualizations of diversity and marginalization, advanced age and other sociodemographic variables intersect and result in unique experiences for each group and individual. Below are a few highlighted areas for consideration.
Sex and gender
Older adults are more likely to be female. Women live longer than men, and so populations of older adults are, with each successive age bracket, increasingly dominated by women. Over half (58%) of Americans over age 65 are women, a number which rises to 69% over age 85, and finally to 80% over age 100.
Older men and women also have different medical and psychological health needs, as well as different profiles of risk and protective factors for acquiring physical and mental disorders. Many biological and psychosocial variables are responsible for these differences. Sex-specific hormonal and physiological differences contribute to different risks for cancer, cardiovascular disease, arthritis, osteoporosis, diabetes, depression, and dementia. Environmental and lifestyle factors, such as sleeping, eating, and exercise habits, social network, socioeconomic resources and stressors, and intellectual engagement in work and leisure activities, also significantly contribute to physical and mental health, and are differentiated between older men and older women. Older women are more likely to have a robust social network—a factor associated with better physical and mental health. Older women from other countries tend to acculturate differently than elderly men. Older women are also twice as likely to live in poverty as older men.
Cultural groups assign different roles and values to individuals based on their gender. Women in some cultural groups are less likely to have been employed, and have lower economic resources as a result. Women are also more likely to bear most of the caregiving responsibilities for ailing family members and young children.
Race and ethnicity
Ethnogeriatrics is defined by the American Geriatrics Society as the "influence of ethnicity and culture on the health the well-being of older adults". In 2015, non-Hispanic White Americans made up an estimated 61.72% of the US population, but that percentage is anticipated to drop to 43.65% by 2060. This demographic shift will be due in part to increases in Asian and Pacific Islander and Latino/Hispanic immigrants. However, Latino and Hispanic older adults as a group are expected to increase the most dramatically, by 155%.
Older adults of different ethnicities belong to different cultural groups, and may therefore have significantly different levels of access to care, different beliefs about health and aging, different expectations from care providers, and different ways of communicating their needs. In addition, ethnic minorities are vulnerable to multiple forms of minority stress: racial prejudice, discrimination, and stereotyping may contribute to lower socioeconomic status, diminished access to care, and systematic disempowerment for many minority groups in the United States. These factors have a major impact on vulnerability to poorer health, risk of mental disorders, and poorer overall prognosis.
Individuals may also belong to multiple racial and ethnic groups: older adults may be biracial or multiracial, belong to indigenous or nonindigenous populations, or be immigrants or the children of immigrants. Different ethnic groups have different genetic and cultural vulnerabilities to medical and psychological problems, which require culturally knowledgeable care.
Sexual and gender minorities
Sexual and gender minorities (lesbian, gay, bisexual, pansexual, transgender, and nongendered individuals) make up an increasing portion of aging populations, and prevalence rates of these groups are expected to rise dramatically. It is estimated that 1.5 million Americans over age 65 identify as lesbian, gay, or bisexual. Because LGBT older adults are less likely to have children and more likely to be single than heterosexual older adults, reduced family support and long-term care is available to them. LGBT older adults also have lower rates of health insurance coverage, and fear discrimination by doctors and mental health care facilities. Among LGBT older adults, 8.3% have reported abuse by a caretaker due to sexual orientation or gender identity. Professional caregivers are also often untrained in the special needs of LGBT populations, and LGBT elders may be overlooked or ignored by many programs oriented towards older populations. The American Psychological Association offers a poignant article about the "double-whammy discrimination" from healthcare provider biases that affect the quality of care of older LGBT patients.
Research has shown that LGBT elders tend to be unwelcome in senior centers and volunteer programs for older adults, and tend to be overlooked in public outreach programs geared towards the elderly. They also may be denied independent housing, as well as entrance to residential nursing home and retirement communities based on sexual orientation or gender identity. They may be isolated from social resources they may otherwise have had from their extended families due to discrimination. In addition, LGBT elders may still be denied visitation rights and end-of-life decision making for their partners and loved ones by hospitals, despite the marriage equality ruling of 2015.
Religious and/or spiritual identity
Older adults tend to be more deeply involved in religious activities than younger adults. Bengston, Putney, Silverstein, and Harris studied aging patterns and generation trends regarding religiosity (namely, Christianity and Judaism) in the United States. Ultimately, the results indicated an overall aging effect with an upward drift in religious intensity and strength of beliefs. Additionally, there was a generational effect indicating different conceptualizations of a monotheistic God based on one's generational cohort and a greater separation between religiosity and spirituality in later-born cohorts.
In a longitudinal study, Wink and Dillon found that adults increased significantly in spirituality between late middle (mid-50s to early 60s) and older adulthood (late 60s to mid-70s); this finding was irrespective of gender and generational cohort. They defined spirituality as "the self's existential search for ultimate meaning through an individualized understanding of the sacred".
Glicksman suggests that one be cautious when interpreting the results of research on spirituality, suggesting that measurement scales are often biased by the Protestant traditions that have shaped the American majority culture. Thus, while it is important to consider how age may impact religiosity and spirituality, it is also important to maintain a sensitive and multicultural approach to understanding an individual's unique relationship with his/her religion and how it may be impacted by other cultural variables, such as country of origin, race, and ethnicity.
Based on the research cited above, it is clear that religion and spirituality are relevant issues for older adults but that these terms may be conceptualized differently and also hold different levels of importance to different individuals. Professionals must be aware of this level of diversity when working with a geriatric population.
Ability and disability status
Older adults who are aging with disabilities are yet another diverse group of individuals, with estimates of approximately 12 to 15 million older adults aging with early-onset disabilities. As medical and social advances increase and improve lifespan and quality of life for those with disabilities, this number will continue to grow. These individuals may experience unique stigma related to the aging process. A seminal and widely adopted definition of "successful aging" included growing older without disability as a hallmark of such success. However, Romo and colleagues conducted a focus group of ethnically diverse older adults with disabilities and found that despite disability, the majority felt they were aging successfully. Such individuals often employed diverse coping strategies to compensate for any changes in physical functioning. As with other groups of older adults, healthcare goals for those with disabilities emphasize reducing risk for chronic disease and preventing further disability and morbidity. However, such a narrow sense of "success" that precludes disability may limit inclusion and diversity. Like other aspects of gerodiversity and experience of marginalization, understanding an individual's sense of successful aging within the context of disability is subjective and likely varies between individuals. Conceptualization of gerodiversity should strive toward inclusion and thus include both disability/ability status as well as subjective experiences of "successful aging", including adaptation and coping with any physical limitations.
Socioeconomic status
Socioeconomic status (SES) is frequently a combined measure of income, education, and occupation. One's SES impacts one's daily life and opportunities, especially those related to quality of life and health care. The elderly in the United States are one of the most economically vulnerable groups. As of 2006, nearly 10% of the elderly in the United States lived below the poverty line. An inability to work, declines in health, and the loss of a spouse are a few of the causes contributing to a lowering of one's SES as one ages. Female and racial/ethnic minority statuses are additional risk-factors for low SES in older adults. Fleck reported that approximately 23% of older African Americans and 19% of older Hispanics live in poverty; Lee and Shaw found that women are nearly twice as likely to be impoverished as males.
The American Psychological Association reports that older adults with low SES can only afford substandard levels of care, if at all, and that mortality rates are significantly higher in low SES older adults. This applies to both physical and mental health care. Additionally, older adults with lower education and/or who come from low-income environments are more likely to develop depression; these risk factors are also associated with higher incidences of Alzheimer's disease and dementia. It is important to be aware of an older patient or client's resources and coping styles. Healthcare providers and other professionals working with older adults must also be aware of what their community may offer for aging individuals of low SES.
Rural versus urban living environment
According to the National Rural Health Association (NRHA), the elderly make up a large percentage of the rural American population with approximately 20% of older adults living in non-metropolitan areas. The living environment and occupational opportunities available to rural elders impacts their health throughout their lifetime. Furthermore, their health is impacted by limited access to care for prevention, management, and treatment of physical and mental health conditions. It can be particularly difficult for elders and their families when they have difficulty completing activities of daily living and are unable to provide their own transportation.
It is important to acknowledge and maintain awareness of the obstacles to healthcare that older individuals in rural communities face. Some older research did not find rural older adults to be disadvantaged in their use of health-related services in comparison to urban dwelling older adults. However, distance to providers and healthcare facilities have been cited as a common barrier among rural-dwelling veterans. While not an issue exclusive to rural locations, older adults cite difficulty traveling and lack of transportation, as well as affordability of care, as the most common barriers to utilizing psychological services. Transportation barriers to healthcare access may be most notable for those with lower incomes. Telehealth (also known as telemedicine; with related specialties of telepsychiatry, telemental health, and telenursing, to name a few ) is one such way that health care providers, researchers, and policy makers are striving to offset the physical distance and related barriers in rural health care delivery. Such provision of services using telecommunications can also be used to deliver care when patients are immobilized, have chronic conditions requiring monitoring, or are homebound.
National identity/origins
An increasing number of Americans, both adults and older adults, can claim a foreign national identity. The Pew Research Center projects that by 2050, nearly one in five Americans will be foreign born. Issues of national origin may dovetail with issues of citizenship for some older adults; the latter confers social and legal rights that interact with the experience of aging to include access to healthcare (including Medicare in the U.S.) and other social and financial welfare programs (e.g., Social Security). In addition, cultural perspectives of aging can profoundly shape one's experience of growing old. Regardless of citizenship, older adults with diverse national identities may experience the aging process differently in the U.S. compared to their country of origin. There is much variability with which cultures approach aging, frailty, and death. For some, a veneration of youth marks aging as a shameful process and likely contributes to ageism in the U.S. and other Westernized countries. However, an increasingly globalized world requires a review of theoretical frameworks and research agendas to better understand cross-cultural differences in aging attitudes.
Courses of action
A report of the APA Committee on Aging offered overarching recommendations for fostering multicultural competencies in working with older adults. Clinicians, researchers, and others in organizations that interface with older adults are called upon to recognize and dispel ageism, both professionally and personally. Key to this is recognizing age as an element of cultural diversity. There are multiple levels at which to conceptualize gerodiversity, beginning with individual factors, and expanding to organizational, institutional, political, and societal frameworks. The article herein emphasizes individual experiences of social inequality to consider with the acknowledgement that aging occurs in a diverse sociocultural and political milieu. Gerodiversity and multicultural competence also posits that age will intersect with other elements of diversity, with incredible variation among individuals. Above all, a gerodiversity approach emphasizes the strengths that come from cultural diversity.
Fostering such a multicultural approach to the issues of aging is a developmental process that begins with education and training and evolves over the course of one's professional and personal experiences. Molinari recommended that opportunities for education and training with older adults be available as early as high school and college. There is a dearth of healthcare workers, including psychologists and physicians, adequately trained to address the needs of the aging population. Therefore, some advocate for geriatric training as a core competency in graduate and internship programs in clinical psychology. Notably, the US Health Resources and Services Administration (HRSA) has devoted funding to preparing health care providers, including nurses, social workers, and psychologists, to better meet the needs of older adults through the Geriatric Workforce Enhancement Program.
Notably, one's development and competency in gerodiversity extends past one's formal education. Molinari urges clinicians and researchers to seek independent learning opportunities with a multicultural focus and inclusion of the geriatric population. Providers and policy makers are encouraged to provide outreach for physical and mental health care for older adults, perhaps in the context of equally diverse settings, such as faith communities. The APA Guidelines for Psychological Practice with Older Adults advises clinicians to promote evidence-based treatments shown to be effective with older populations, and seek supervision or consultation on such practice issues. Finally, from a systems perspective, a gerodiverse approach to clinical practice, research, and policy will be fostered with research on evidence-based treatment approaches for diverse older adults, as well as dissemination of such work so that the public is educated about common mental disorders in the elderly, which may eliminate stigma. Supporting federal initiatives to train health workers in gerontology, particularly with multicultural considerations, and advocating for increased funding for research in these areas, is a crucial ongoing step.
References
Sources
See also
Gender variance
External links
Bibliography of Research and Clinical Perspectives on LGBT Aging (2008) (PDF, 99KB)
Curriculum in Ethnogeriatrics (2002) 2nd edition, Stanford University Collaborative of Ethnogeriatric Education
Diversity Advancement Toolkit: Strengthening Cultural Competence within National Aging Network, Area Agencies on Aging, Title VI Programs and Service Providers
Ethnogeriatric Competencies for Care Providers
Fact Sheet on Aging and Socioeconomic Status (2010)
Family Caregiver Briefcase — Variations for Practice for Culturally Diverse Groups (2011), American Psychological Association Presidential Task Force on Caregivers
Multicultural Competency in Geropsychology
Older Americans Behavioral Health Issue Brief 11: Reaching Diverse Older Adult Populations and Engaging Them in Prevention Services and Early Interventions (2011) (PDF, 1MB)
Reference and Resource Guide for Working with Hispanic/Latino Older Adults, Based on Treatment Improvement Protocol 26: Substance Abuse Among Older Adults (2008)
Stanford Geriatric Education Center
Teaching and Learning about Aging (2008)
The Aging and Health Report: Disparities and Resilience among Lesbian, Gay, Bisexual, and Transgender Older Adults (2012) (PDF, 14KB),
The Mental Health and Substance Use Workforce for Older Adults: In Whose Hands? (2012), Institute of Medicine
The Resource Centers for Minority Aging Research
Toward an Inclusive Psychology: Infusing the Introductory Psychology Textbook with Diversity Content (2003) (PDF, 3MB)
Transforming Mental Health Services for Older People: Lesbian, Gay, Bisexual and Transgender Challenges and Opportunities (2007), FORGE: Transgender Aging Network
Caregiving
Gerontology
Social justice | Gerodiversity | [
"Biology"
] | 3,819 | [
"Gerontology"
] |
53,030,665 | https://en.wikipedia.org/wiki/IBM%20System/390 | The IBM System/390 is a discontinued mainframe product family implementing ESA/390, the fifth generation of the System/360 instruction set architecture. The first computers to use the ESA/390 were the Enterprise System/9000 (ES/9000) family, which were introduced in 1990. These were followed by the 9672, Multiprise, and Integrated Server families of System/390 in 1994–1999, using CMOS microprocessors. The ESA/390 succeeded ESA/370, used in the Enhanced 3090 and 4381 "E" models, and the System/370 architecture last used in the IBM 9370 low-end mainframe. ESA/390 was succeeded by the 64-bit z/Architecture in 2000.
History
On September 5, 1990, IBM published a group of hardware and software announcements, two of which included overviews of three announcements:
System/390 (S/390), as in 360 for 1960s, 370 for 1970s.
Enterprise System/9000 (ES/9000), as in 360 for 1960s, 370 for 1970s.
Enterprise Systems Architecture/390 (ESA/390) was IBM's last 31-bit-address/32-bit-data mainframe computing design, copied by Amdahl, Hitachi, and Fujitsu among other competitors. It was the successor of ESA/370 and, in turn, was succeeded by the 64-bit z/Architecture in 2000. Among other things, ESA/390 added fiber optics channels, known as Enterprise Systems Connection (ESCON) channels, to the parallel (Bus and Tag) channels of ESA/370.
Despite the fact that IBM mentioned the 9000 family first in some of the day's announcements, it was clear "by the end of the day" that it was "for System/390," although it was a shortened name, S/390, that was placed on some of the actual "boxes" later shipped.
The ES/9000 include rack-mounted models, free standing air cooled models and water cooled models. The low end models were substantially less expensive than the 3090 or 4381 previously needed to run MVS/ESA, and could also run VM/ESA and VSE/ESA, which IBM announced at the same time.
IBM periodically added named features to ESA/390 in conjunction with new processors; the ESA/390 Principles of Operation manual identifies them only by name, not by the processors supporting them.
Machines supporting the architecture were sold under the brand System/390 (S/390) from September 1990. The 9672 implementations of System/390 were the first high-end IBM mainframe architecture implemented first with CMOS CPU electronics rather than the traditional bipolar logic.
The IBM z13 was the last z Systems server to support running an operating system in ESA/390 architecture mode. However, all 24-bit and 31-bit problem-state application programs originally written to run on the ESA/390 architecture readily run unaffected by this change.
S/390 computers
ES/9000
Eighteen models were announced September 5, 1990 for the ES/9000 in three form factors; the water-cooled 9021 to succeed the IBM 3090, and the air-cooled standalone 9121 and rack-mounted 9221 to succeed the IBM 4381 and 9370 respectively. The largest announced model had a 100-fold performance over the smallest model, and the clock frequency ranged from 67-111 MHz (15-9 ns) in the 9021 and 67 MHz in the 9121 to 26-33 MHz (38-30 ns) in the 9221. The 9221 models 120, 130 and 150 were initially available only with the "System/370 Base Option"; the "ESA Option" shipped in July 1991. The 9221 processors were made of VLSI CMOS chips designed in Böblingen, Germany, whence the 9672 line later originated.
The lower 6 of the 8 water-cooled models (codenamed H0) were immediately available, but used the same processor as the 3090-J, still at the 69 MHz (14.5 ns) maximum frequency and thus with unchanged performance. Those models' main difference from the 3090-J was the optional addition of ESCON, Sysplex and Integrated Cryptographic Feature. Only the models 900 and 820 had an all-new design (codenamed H2), featuring private split I+D 128+128 KB L1 caches and a shared 4 MB L2 cache (2 MB per side) with 11-cycle latency, more direct interconnects between the processors, multi-level TLBs, branch target buffer and 111 MHz (9 ns) clock frequency. These were the first models with out-of-order execution since the System/370-195 of 1973. However unlike the old S/360-91-derived systems, the models 900 and 820 had full out-of-order execution for both integer and floating-point units, with precise exception handling, and a fully superscalar pipeline. Models 820 and 900 shipped to customers in September 1991, a year later than the models with older technology. Later these new technologies were used in models 520, 640, 660, 740 and 860.
All three lines got additions and upgrades until 1993–1994. In February 1993 an 8-processor 141 MHz (7.1 ns) model 982 became available, with models 972, 962, 952, 942, 941, 831, 822, 821 and 711 following in March. These models, codenamed H5, had double the L2 cache and 30% higher per-processor performance than the H2 line, and added a hardware data compression. The compression was also included in the new, 50% faster models of the 9121. In April 1994, alongside the CMOS-based new 9672 series and improved 9221 models (with 40% faster cycle time and data compression), IBM announced also their ultimate bipolar model, the 10-processor model 9X2 rated at 468 MIPS, to become available in October.
Models
ES/9000 features
ESCON fiber optic channels
Sysplex for synchronizing the systems to ease management
Vector Facility: up to one vector processor per Central Processor available on the 9021 and 9121. First used on the 3090 to replace the IBM 3838 array processor announced in 1976 for System/370.
Up to one Integrated Cryptographic Feature (ICRF) per side was available on the 9021 for accelerating encryption, succeeding the 3848 Cryptographic Unit.
(Each Central Processor accommodates one coprocessor at a time; the combined number of installed Vector Facilities and ICRFs cannot exceed the number of Central Processors.)
The new models of the 9021 and 9121 from 1993 and 9221 from 1994 feature data compression hardware.
Logical partitioning
Previously available only on IBM 3090, Logical Partitions (LPARs) are a standard feature of the ES/9000 processors whereby IBM's Processor Resource/Systems Manager (PR/SM) hypervisor allows different operating systems to run concurrently in separate logical partitions (LPARs), with a high degree of isolation. Initially 7 partitions per a disconnected side were supported. In December 1992 the LPAR capacity of the H2 (520-based) models was increased to 10 per a disconnected side. For example, a two-processor model 660 could now support up to 20 partitions instead of 14, if the two sides (each with one processor) are electrically isolated.
This was introduced as part of IBM's moving towards "lights-out" operation and increased control of multiple system configurations.
9672
Launched in 1994 first as the "Parallel Transaction Server" (alongside the 9673 "Parallel Query Server"), subsumed by the "Parallel Enterprise Server" launched later in the year, the six generations of the IBM 9672 machines transitioned IBM's mainframes fully to CMOS microprocessors, as by a strategic decision no more ES/9000 (bipolar-based except the 9221) models would be released after 1994. The initial generations of 9672 were slower than the largest ES/9000 sold in parallel, but the fifth and sixth generations were the most powerful and capable ESA/390 machines built by IBM.
In the course of the generations, CPUs added more instructions and increased performance. The first three generations (G1 to G3) focused on low cost. The 4th generation was aimed at matching the performance of the last bipolar model, the 9021-9X2. It was decided to be accomplished by pursuing high clock frequencies. The G4 could reach 70% higher frequency than the G3 at silicon process parity, but it suffered a 23% IPC reduction from the G3. The initial G4-based models became available in June 1997, but it wasn't until the 370 MHz model RY5 (with a "Modular Cooling Unit") became available at the end of the year that a 9672 would almost match the 141 MHz model 9X2's performance. At 370 MHz it was the second-highest clocked microprocessor at the time, after the Alpha 21164 of DEC. The execution units in each G4 processor are duplicated for the purpose of error detection and correction. Arriving in late September 1998, the G5 more than doubled the performance over any previous IBM mainframe, and restored IBM's performance lead that had been lost to Hitachi's Skyline mainframes in 1995. The G5 operated at up to 500 MHz, again second only to the DEC Alphas into early 1999. The G5 also added support for the IEEE 754 floating-point formats. The thousandth G5 system shipped less than 100 days after the manufacturing began; the greatest ramping of production in S/390's history. In late May 1999 the G6 arrived featuring copper interconnects, raising the frequency to 637 MHz, higher than the fastest DEC machines at the time.
Other
In September 1996 IBM launched the S/390 Multiprise 2000, positioned below the 9672. It used the same technology as the 9672 G3, but it fit half as many processors (up to five) and its off-chip caches were smaller. The 9672 G3 and the Multiprise 2000 were the last versions to support pre-XA System/370 mode. In October 1997 models of Multiprise 2000 with an 11% higher performance were launched. The Multiprise 3000, based on the 9672 G5, became available in September 1999, featuring PCI buses.
The S/390 Integrated Server, an even lower-end S/390 system than Multiprise, shipped by the end of 1998. It emerged from a line of S/390-compatibility/coprocessor cards for PCs, but is a true S/390 system capable of server duties, having relegated the Pentium II to the role of an I/O coprocessor. It was the first S/390 server to support PCI. It had the same performance and 256 MB maximum memory capacity as the 7 years older low-end 9221 model 170.
From 1997 IBM also offered a "S/390 Application StarterPak", intended as a software development kit for developing and testing mainframe software.
See also
IBM System/360
IBM System/370
IBM 30XX mainframe lines
IBM 303X
IBM 308X
IBM 3090
IBM Z
Notes
References
External links
IBM
IBM Z mainframe homepage
Current IBM Z mainframe servers
IBM System/390 Photo
Multiple links and references.
Exterior and interior images of the IBM 390.
Computing platforms
390
32-bit computers | IBM System/390 | [
"Technology"
] | 2,413 | [
"Computing platforms"
] |
53,031,520 | https://en.wikipedia.org/wiki/Health%20impact%20of%20asbestos | All types of asbestos fibers are known to cause serious health hazards in humans. The most common diseases associated with chronic exposure to asbestos are asbestosis and mesothelioma.
Amosite and crocidolite are considered the most hazardous asbestos fiber types; however, chrysotile asbestos has also produced tumors in animals and is a recognized cause of asbestosis and malignant mesothelioma in humans, and mesothelioma has been observed in people who were occupationally exposed to chrysotile, family members of the occupationally exposed, and residents who lived close to asbestos factories and mines.
During the 1980s and again in the 1990s it was suggested at times that the process of making asbestos cement could "neutralize" the asbestos, either via chemical processes or by causing cement to attach to the fibers and changing their physical size; subsequent studies showed that this was untrue, and that decades-old asbestos cement, when broken, releases asbestos fibers identical to those found in nature, with no detectable alteration.
Risks
Exposure to asbestos in the form of fibers is always considered dangerous. Working with, or exposure to, material that is friable, or materials or works that could cause release of loose asbestos fibers, is considered high risk. However, in general, people who become ill from inhaling asbestos have been regularly exposed in a job where they worked directly with the material.
According to the National Cancer Institute, "A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos." A paper published in 1998, in the American Journal of Respiratory and Critical Care Medicine, concurs, and comments that asbestosis has been reported primarily in asbestos workers, and appears to require long-term exposure, high concentration for the development of the clinical disease. There is also a long latency period (the time taken between harmful contact and emergence of the actual resulting illness) of about 12 to 20 years, and potentially up to 40 years.
The most common diseases associated with chronic exposure to asbestos are asbestosis and mesothelioma.
According to OSHA, "there is no 'safe' level of asbestos exposure for any type of asbestos fiber. Asbestos exposures as short in duration as a few days have caused mesothelioma in humans. Every occupational exposure to asbestos can cause injury or disease; every occupational exposure to asbestos contributes to the risk of getting an asbestos related disease."
Asbestos-related diseases
Diseases commonly associated with asbestos include:
Asbestosis: Progressive fibrosis of the lungs of varying severity, progressing to bilateral fibrosis, honeycombing of the lungs on radiological view with symptoms including rales and wheezing. Individuals who have been exposed to asbestos via home, environment, or work should notify their doctors about exposure history.
Asbestos warts: caused when the sharp fibers lodge in the skin and are overgrown causing benign callus-like growths.
Pleural plaques: discrete fibrous or partially calcified thickened area which can be seen on X-rays of individuals exposed to asbestos. Although pleural plaques are themselves asymptomatic, in some patients this develops into pleural thickening.
Diffuse pleural thickening: similar to above and can sometimes be associated with asbestosis. Usually no symptoms shown but if exposure is extensive, it can cause lung impairment.
Pneumothorax: Some reports have also linked the condition of pneumothorax to asbestos related diseases.
Malignant mesothelioma: an aggressive and incurable tumour arising from mesothelial cells of the pleura (the lining of the thoracic cavity).
Safety and exposure prevention
Asbestos exposure becomes an issue if asbestos containing materials become airborne, such as due to deterioration or damage. Building occupants may be exposed to asbestos, but those most at risk are persons who purposely disturb materials, such as maintenance or construction workers. Housekeeping or custodial employees may be at an increased risk as they may potentially clean up damaged or deteriorated asbestos containing materials without knowing that the material contains asbestos. Asbestos abatement or remediation workers and emergency personnel such as firefighters may also become exposed. Asbestos-related diseases have been diagnosed in asbestos workers' family members, and in residents who live close to asbestos mines or processing plants.
Common building materials containing asbestos
Currently in the United States, several thousand products manufactured and/or imported today still contain asbestos. In many parts of the industrialized world, particularly the European Union, asbestos was phased out of building products beginning in the 1970s with most of the remainder phased out by the 1980s. Even with an asbestos ban in place, however, asbestos may be found in many buildings that were built and/or renovated from the late 1800s through the present day.
Residential building materials containing asbestos include a variety of products, such as: stipple used in textured walls and ceilings; drywall joint filler compound; asbestos contaminated vermiculite, vinyl floor tile; vinyl sheet flooring; window putty; mastic; cement board; asbestos cement pipes and flues; furnace tape; and stucco. Asbestos is widely used in roofing materials, mainly corrugated asbestos cement roof sheets and asbestos shingles sometimes called transite. Other sources of asbestos-containing materials include fireproofing and acoustic materials.
Identification and assessment
A fiber cannot be identified or ruled out as asbestos, either using the naked eye or by simply looking at a fiber under a regular microscope. The most common methods of identifying asbestos fibers are by using polarized light microscopy (PLM) or transmission electron microscopy (TEM). PLM is less expensive, but TEM is more precise and can be used at lower concentrations of asbestos.
If asbestos abatement is performed, completion of the abatement is verified using visual confirmation and may also involve air sampling. Air samples are typically analyzed using phase contrast microscopy (PCM). PCM involves counting fibers on a filter using a microscope. Airborne occupational exposure limits for asbestos are based on using the PCM method.
The American Conference of Governmental Industrial Hygienists has a recommended Threshold Limit Value (TLV) for asbestos of 0.1 fibers/mL over an 8-hour shift. OSHA in the United States and occupational health and safety regulatory jurisdictions in Canada use 0.1 fibers/mL over an 8-hour shift as their exposure limits.
Environmental asbestos
Asbestos can be found naturally in the air outdoors and in some drinkable water, including water from natural sources. Even nonoccupationally exposed members of the human population have tens to hundreds of thousands of asbestos fibers per gram of dry lung tissue, equivalent to millions of fibers in each lung.
Asbestos from natural geologic deposits is known as "naturally occurring asbestos" (NOA). Health risks associated with exposure to NOA are not yet fully understood, and current US federal regulations do not address exposure from NOA. Many populated areas are in proximity to shallow, natural deposits which occur in 50 of 58 California counties and in 19 other US states. In one study, data was collected from 3,000 mesothelioma patients in California and 890 men with prostate cancer, a malignancy not known to be related to asbestos. The study found a correlation between the incidence of mesotheliomas and the distance a patient lived from known deposits of rock likely to include asbestos; the correlation was not present when the incidence of prostate cancer was compared with the same distances. The risk of mesothelioma declined by 6% for every that an individual had lived away from a likely asbestos source.
Portions of El Dorado County, California are known to contain natural amphibole asbestos formations at the surface. The USGS studied amphiboles in rock and soil in the area in response to an EPA sampling study and subsequent criticism of the EPA study. The EPA study was refuted by its own peer reviewers and never completed or published. The study found that many amphibole particles in the area meet the counting rule criteria used by the EPA for chemical and morphological limits, but do not meet morphological requirements for commercial-grade-asbestos. The executive summary pointed out that even particles that do not meet requirements for commercial-grade-asbestos may be a health threat and suggested a collaborative research effort to assess health risks associated with "Naturally Occurring Asbestos."
However, the main criticism pointed at EPA was that their testing was conducted in small isolated areas of El Dorado where there were no amphibole asbestos deposits, thus the language regarding amphibole, nonfibrous "particles". Actual surface amphibole deposits in residential areas were ignored for testing purposes. Because of this, no final findings were published by ATSDR.
A great deal of Fairfax County, Virginia was also found to be underlaid with tremolite. The county monitored air quality at construction sites, controlled soil taken from affected areas, and required freshly developed sites to lay of clean, stable material over the ground.
Globally, samples collected from Antarctic ice indicate chrysotile asbestos has been a ubiquitous contaminant of the environment for at least 10,000 years. Snow samples in Japan have shown ambient background levels are one to two orders of magnitude higher in urban than in rural areas. Higher concentrations of airborne asbestos fibers are reported in urban areas where there is more ACM (asbestos containing materials) and mechanisms of release (vehicles braking and weathering of asbestos cement materials); concentrations in the range of 1–20 ng/m3 have been reported. Fibers longer than 5μm are rarely found in rural areas. Ambient concentrations using TEM analysis have been based on mass measurements.
Biological interactions
Mechanisms of carcinogenicity
Stanton and Layard hypothesized in 1977–78 that toxicity of fibrous materials is not initiated by chemical effects; that is, any trigger-effects of asbestos must presumably be physical, such as mechanical damage which might disrupt normal cell activity—especially mitosis.
There is experimental evidence that very slim fibers (<60 nm, <0.06 μm in breadth) tangle destructively with chromosomes (being of comparable size). This is likely to cause the sort of mitosis disruption expected in cancer.
Chemistry
Individual asbestos fibers are invisible to the unaided human eye because their size is about 3–20 μm wide and can be as slim as 0.01 μm. Fibers ultimately form because when these minerals originally cooled and crystallized, they formed by the polymeric molecules lining up parallel with each other and forming oriented crystal lattices. These crystals thus have three cleavage planes, and in this case, there are two cleavage planes which are much weaker than the third. When sufficient force is applied, they tend to break along their weakest directions, resulting in a linear fragmentation pattern and hence a fibrous form. This fracture process can keep occurring and one larger asbestos fiber can ultimately become the source of hundreds of much thinner and smaller fibers.
When fibers or asbestos structures from asbestos containing materials (ACM) become airborne, the process is called primary release. Primary release mechanisms include abrasion, impaction, fallout, air erosion, vibration, and fire damage. Secondary release occurs when settled asbestos fibers and structures are resuspended as a result of human activities. In unoccupied buildings or during unoccupied periods, fiber release typically occurs by fallout or is induced by vibration or air erosion.
Friability of a product containing asbestos means that it is so soft and weak in structure that it can be broken with simple finger crushing pressure. Friable materials are of the most initial concern because of their ease of damage. The forces or conditions of usage that come into intimate contact with most non-friable materials containing asbestos are substantially higher than finger pressure.
Smoking and asbestos
Smoking has a supra-additive effect in increasing the risk of lung cancer in those exposed to asbestos. Studies have shown an increased risk of lung cancer among smokers who are exposed to asbestos compared to nonsmokers.
History of health concerns and regulation
For additional chronological citations, see also, List of asbestos disease medical articles
Until 1900
Early concern in the modern era on the health effects of asbestos exposure can be found in several sources. Among the earliest were reports in Britain. The annual reports of the Chief Inspector of Factories in 1898 included a report from Lucy Deane which stated that asbestos had "easily demonstrated" health risks.
At about the same time, what was probably the first study of mortality among asbestos workers was reported in France. While the study describes the cause of death as chalicosis, a generalized pneumoconiosis, the circumstances of the employment of the fifty workers whose death prompted the study suggest that the root cause was asbestos or mixed asbestos-cotton dust exposure.
1900s–1910s
Awareness of asbestos-related diseases can be found in the early 1900s, when London doctor H. Montague Murray conducted a post mortem exam on a young asbestos factory worker who died in 1899. Dr. Murray gave testimony on this death in connection with an industrial disease compensation hearing. The post-mortem confirmed the presence of asbestos in the lung tissue, prompting Dr. Murray to express as an expert opinion his belief that the inhalation of asbestos dust had at least contributed to, if not actually caused, the death of the worker.
The record in the United States was similar. Early observations were largely anecdotal in nature and did not definitively link the occupation with the disease, followed by more compelling and larger studies that strengthened the association. One such study, published in 1918, noted:
All of these processes unquestionably involve a considerable dust hazard, but the hygienic aspects of the industry have not been reported upon. It may be said, in conclusion, that in the practice of American and Canadian life insurance companies, asbestos workers are generally declined on account of the assumed health-injurious conditions of the industry.
1920s–1930s
Widespread recognition of the occupational risks of asbestos in Britain was reported in 1924 by a Dr. Cooke, a pathologist, who introduced a case description of a 33-year-old female asbestos worker, Nellie Kershaw, with the following: "Medical men in areas where asbestos is manufactured have long suspected the dust to be the cause of chronic bronchitis and fibrosis ..." Dr. Cooke then went on to report on a case in 1927 involving a 33-year-old male worker who was the only survivor out of ten workers in an asbestos carding room. In the report he named the disease "asbestosis".
Dr. Cooke's second case report was followed, in the late 1920s, by a large public health investigation (now known as the Merewether report after one of its two authors) that examined some 360 asbestos-textile workers (reported to be about 15% of the total comparable employment in Britain at the time) and found that about a quarter of them had pulmonary fibrosis. This investigation resulted in improved regulation of the manufacturing of asbestos-containing products in the early 1930s. Regulations included industrial hygiene standards, medical examinations, and inclusion of the asbestos industry into the British Workers' Compensation Act.
The first known U.S. workers' compensation claim for asbestos disease was in 1927. In 1930, the first reported autopsy of a person with asbestosis was conducted in the United States and later presented by a doctor at the Mayo Clinic, although in this case the exposure involved mining activities somewhere in South America.
In 1930, the major asbestos company Johns-Manville produced a report, for internal company use only, about medical reports of asbestos worker fatalities. In 1932, a letter from U.S. Bureau of Mines to asbestos manufacturer Eagle-Picher stated, in relevant part, "It is now known that asbestos dust is one of the most dangerous dusts to which man is exposed."
In 1933, Metropolitan Life Insurance Co. doctors found that 29% of workers in a Johns-Manville plant had asbestosis. Likewise, in 1933, Johns-Manville officials settled lawsuits by 11 employees with asbestosis on the condition that the employees' lawyer agree to never again "directly or indirectly participate in the bringing of new actions against the Corporation." In 1934, officials of two large asbestos companies, Johns-Manville and Raybestos-Manhattan, edited an article about the diseases of asbestos workers written by a Metropolitan Life Insurance Company doctor. The changes downplayed the danger of asbestos dust. In 1935, officials of Johns-Manville and Raybestos-Manhattan instructed the editor of Asbestos magazine to publish nothing about asbestosis. In 1936, a group of asbestos companies agreed to sponsor research on the health effects of asbestos dust, but required that the companies maintain complete control over the disclosure of the results.
1940s
In 1942, an internal Owens-Corning corporate memo referred to "medical literature on asbestosis ... scores of publications in which the lung and skin hazards of asbestos are discussed." Testimony given in a federal court in 1984 by Charles H. Roemer, formerly an employee of Unarco, described a meeting in the early 1940s between Unarco officials, J-M President Lewis H. Brown and J-M attorney Vandiver Brown. Roemer stated, "I'll never forget, I turned to Mr. Brown, one of the Browns made this crack (that Unarco managers were a bunch of fools for notifying employees who had asbestosis), and I said, 'Mr. Brown, do you mean to tell me you would let them work until they dropped dead?' He said, 'Yes. We save a lot of money that way.'" In 1944, a Metropolitan Life Insurance Company report found 42 cases of asbestosis among 195 asbestos miners.
1950s
In 1951, asbestos companies removed all references to cancer before allowing publication of research they sponsored. In 1952, Dr. Kenneth Smith, Johns-Manville medical director, recommended (unsuccessfully) that warning labels be attached to products containing asbestos. Later, Smith testified: "It was a business decision as far as I could understand ... the corporation is in business to provide jobs for people and make money for stockholders and they had to take into consideration the effects of everything they did and if the application of a caution label identifying a product as hazardous would cut into sales, there would be serious financial implications."
In 1953, National Gypsum's safety director wrote to the Indiana Division of Industrial Hygiene, recommending that acoustic plaster mixers wear respirators "because of the asbestos used in the product." Another company official noted that the letter was "full of dynamite" and urged that it be retrieved before reaching its destination. A memo in the files noted that the company "succeeded in stopping" the letter, which "will be modified."
1960s–1980s
Through the 1970s, asbestos was used to fireproof roofing and flooring, for heat insulation, and for a variety of other purposes. The material was used in fire-check partitioning and doors on North Sea Oil Production Platforms and Rigs.
During the mid-to late 1980s, public health concern focused on potential asbestos fiber exposures of building occupants and workers in buildings containing asbestos containing building materials (ACBM) and their risks of developing lung cancer or mesothelioma. As a consequence, the Health Effects Institute (Cambridge, MA) convened a panel to evaluate the lifetime cancer risk of general building occupants as well as service workers.
Modern regulation
United States
The United States remains one of the few developed countries to not completely ban asbestos. While it has banned its use for certain items, it is legal for use in products such as clothing, pipeline wraps, vinyl floor tiles, millboards, cement pipes, disk brake pads, gaskets and roof coatings.
In 1989 the EPA issued the Asbestos Ban and Phase Out Rule but in 1991, asbestos industry supporters challenged and overturned the ban in a landmark lawsuit: Corrosion Proof Fittings v. the Environmental Protection Agency. Although the case resulted in several small victories for asbestos regulation, the EPA ultimately did not put an end to asbestos use. This ruling leaves many consumer products that can still legally contain trace amounts of asbestos. For a clarification of products which legally contain asbestos, read the EPA's clarification statement.
In 2010, Washington State banned asbestos in automotive brakes starting in 2014. The Occupational Safety and Health Administration (OSHA), has set limits of 100,000 fibers with lengths greater than or equal to 5 μm per cubic meter of workplace air for eight-hour shifts and 40-hour work weeks.
Canada
In Canada, asbestos is not presently banned, though its use has declined since the mid-1970s and early 1980s. Products containing asbestos are regulated by the Asbestos Products Regulation (SOR 2007/260). On December 16, 2016, parliament stated that as of 2018, all use of asbestos will be totally banned. This happened on December 30, 2018, but its use is still allowed for Nuclear and Military use.
United Kingdom
In the United Kingdom, blue and brown asbestos materials were banned outright in 1985 while the import, sale and second hand reuse of white asbestos was outlawed in 1999. The 2012 Control of Asbestos Regulations state that owners of non-domestic buildings (e.g., factories and offices) have a "duty to manage" asbestos on the premises by making themselves aware of its presence and ensuring the material does not deteriorate, removing it if necessary. Employers, e.g. construction companies, whose operatives may come into contact with asbestos must also provide annual asbestos training to their workers.
New Zealand
In 1984, the import of raw amphibole (blue and brown) asbestos into New Zealand was banned. In 2002 the import of chrysotile (white) asbestos was also banned. In 2015 the government announced that the importation of asbestos would be completely banned with very limited exceptions (expected to be applied to replacement parts for older machines) that would be reviewed on a case-by-case basis.
North-west of Nelson, in the Upper Takaka Valley is New Zealand's only commercially harvested asbestos mine. A low-grade Chrysotile was mined here from 1908 to 1917 but only 100 tons was washed and taken out by packhorse. A new power scheme enabled work to renew and between 1940 and 1949, 40 tons a month was mined by the Hume Company. This continued to 1964, when, due to the short length of its fibre, the limited commercial viability forced mining to cease.
Australia
The use of crocidolite (blue) asbestos was banned in 1967, while the use of amosite (brown) asbestos continued in the construction industry until the mid-1980s. It was finally banned from building products in 1989, though it remained in gaskets and brake linings until 31 December 2003, and cannot be imported, used or recycled.
Asbestos continues to be a problem. Two out of three homes in Australia built between World War II and the early 1980s still contain asbestos.
The union that represents workers tasked with modifying electrical meter boxes at residences stated that workers should refuse to do this work until the boxes have been inspected for asbestos, and the head of the Australian Council of Trade Unions (ACTU) has called on the government to protect its citizens by ridding the country of asbestos by 2030.
Handlers of asbestos materials must have a B-Class license for bonded asbestos and an A-Class license for friable asbestos.
The town of Wittenoom, in Western Australia was built around a blue asbestos mine. The entire town continues to be contaminated, and has been disincorporated, allowing local authorities to remove references to Wittenoom from maps and roadsigns.
In January 2024, asbestos was found in garden mulch supplied to dozens of sites including parks, playgrounds and schools across Sydney, triggering the Sydney asbestos mulch crisis.
Brazil
Despite the mining and use of asbestos reaching the country's Supreme Court, Brazil is the world's third-largest producer and exporter of chrysotile asbestos. São Paulo State law 12.684/07 prohibits the use of any product which utilizes asbestos but many buildings are still constructed of products containing asbestos. As a result, it is estimated that up to 15,000 Brazilians die each year of exposure to asbestos.
Japan
Revelations that hundreds of workers had died in Japan over the previous few decades from diseases related to asbestos sparked a scandal in mid-2005. Tokyo had, in 1971, ordered companies handling asbestos to install ventilators and check health on a regular basis; however, the Japanese government did not ban crocidolite and amosite until 1995, and a near complete ban with a few exceptions on asbestos was implemented in 2006, with the remaining exceptions being removed in March 2012 for a full-fledged ban.
South Korea
In May 1997, the manufacture and use of crocidolite and amosite, commonly known as blue and brown asbestos, were fully banned in South Korea. In January 2009, a full-fledged ban on all types of asbestos occurred when the government banned the manufacture, import, sale, storage, transport or use of asbestos or any substance containing more than 0.1% of asbestos. In 2011, South Korea became the world's sixth country to enact an asbestos harm aid act, which entitles any Korean citizen to free lifetime medical care as well as monthly income from the government if he or she is diagnosed with an asbestos-related disease.
Singapore
Use of all types of asbestos has been banned in Singapore since 1989. Currently, only removal of asbestos-containing materials is allowed in Singapore and the Ministry of Manpower must be notified before work commences.
Turkey
A complete ban on asbestos in Turkey went into effect in 2011.
Finland
The manufacture and import of asbestos containing building materials was banned from 1993 onwards, while the selling and use of such materials was banned from 1994.
Delayed recognition
In a 1998 paper, medical historian Peter Bartrip examines why awareness and legislation appear to have lagged unduly, compared to evidence of the risks of asbestos. The paper concludes by agreeing with a previous paper ('Asbestos: a chronology of its origins and health effects', British Journal of Independent Medicine, 1990) and the 1930 report of Edward Mereweather (a factory medical inspector involved in the legislative investigations of the time), that despite theories suggesting a coverup and historical evidence that could be cobbled together after the fact, it is more likely that the issue was one of hindsight.
According to Bartrip, Mereweather's 1930 report identified six relevant issues:
Significant commercial exploitation of asbestos was still relatively new.
The industry was small and employed comparatively few workers, particularly in dusty processes.
The disease developed slowly and unobtrusively.
The disease was easily confused with tuberculosis.
Affected workers left the industry and therefore fell out of sight of Factory Inspectors. (Gee, below, states that studies "focused on factories, rather than users")
Medical research had concentrated on dusts containing free silica.
There had been earlier discussion, notably a few brief comments by Factory Inspectors Adelaide Anderson and Edgar Collis during 1898–1911, described by Bartrip as minor reports of no great substance in otherwise very large reports about factory workers. As a result, he concludes that between 1898 and the late 1920s, all that can be said is that, "the dangers of the material were slowly beginning to be appreciated". As of 1927, the Senior Medical Inspector had reported that the effect of asbestos dust inhalation "was as yet imperfectly understood".
A second paper, by Gee & Greenberg, noted additional factors:
The discovery of carcinogenicity of smoking at approximately the same time as the 1950s asbestos studies, had made it far harder to prove a proposed causative link for asbestos.
Anecdotal evidence and hearsay noted by local doctors and inspectors, was not pursued or taken seriously.
"Negative" cancer studies were used, which are poor at detecting statistically significant pathology rates unless they include follow-up for around 30 years.
A "latency lacuna" exists and contributes to complacency (also reported by Knox 1965) – as the consequences of exposure take decades to arise, by the time they occur it is possible to argue convincingly that "standards have improved" and that therefore the risk is eliminated; however this in turn is not confirmed for another 30 years by which time the same argument can be raised again. Compared to short-term needs, a "speculative" risk not yet confirmed may carry less weight, until long after the time when action could be taken.
Long term surveys and sanction regimes failed to match short term pressures within politics, nor those within industry; in the case of asbestos they were inadequate.
Fallacious arguments were used, such as the observation that many asbestos workers remained healthy into old age as evidence of lack of risk or lack of harm. As even the most harmful occupation can have numerous apparent healthy survivors this is an example of "absence of evidence" being interpreted as "evidence of absence".
As late as 1967, even The Lancet was capable of writing that "it would be ludicrous to outlaw this valuable and often irreplaceable material in all circumstances (as) asbestos can save more lives than it can possibly endanger".
Litigation
Litigation related to asbestos is regarded as one of the largest litigation cases in legal history in terms of duration, claim size, and scope. Factors responsible for this include:
Asbestos use was extremely widespread: It was used across many sectors, countries, industries and uses. It was also widespread in society itself, being used not in limited "niche" areas but within many everyday products, in housing, fire protection, and even decorative material such as Artex, as well as numerous other ways. Over 50% of homes in some countries contained asbestos even after its ban there. So it was somewhat ubiquitous;
Knowledge or suspicion of health issues existed for a long time: The health issues related to asbestos were known, suspected, or reported, for decades, with modern medical coverage dating back to the 19th century.
Impact was severe, and included factors that tend to lead to high claims: serious and fatal disease; also apart from death the costs include long-term care and disability, care costs, lifetime loss of income, and other high value compensations.
Relatively easy to be at risk: asbestos-related diseases are caused by inhaling tiny airborne fibers, therefore any activity related to asbestos that led to loose dust or fibers could potentially cause disease (Secondary asbestosis). As a result, illness occurred not only in the widespread primary industries using asbestos, such as the asbestos mining and processing businesses, but also across industries that might handle their products (construction and demolition, repairs, fire safety), persons who disturbed asbestos products in their homes or workplaces, and even those who laundered clothing used by asbestos workers.
Illnesses arise long after exposure: asbestos related diseases can arise decades after actual exposure.
Asbestos industry alleged misconduct: alleged concealing, distorting, and suppressing of risk related information, by asbestos related businesses.
, trends indicate that the worldwide rate at which people are diagnosed with asbestos-related diseases will likely increase through the next decade. Analysts have estimated that the total cost of asbestos litigation in the USA alone is over $250 billion.
In the United Kingdom, more people died in 2011 from asbestos-related causes (4721) than in all types of traffic and transport accidents combined, and new reported cases were estimated at 2126.
In the United States, asbestos litigation is the longest, most expensive mass tort in U.S. history, involving more than 8,400 defendants and 730,000 claimants as of 2002 according to the RAND Corporation, and at least one defendant reported claim counts in excess of $800,000 in 2006.
The federal legal system in the United States has dealt with numerous counts of asbestos-related suits, which often included multiple plaintiffs with similar symptoms. In 1999 there were 200,000 related cases pending in the federal court system of the United States. Further, it is estimated that within the next 40 years, the number of cases may increase to 700,000. These numbers help explain how there are thousands of current pending cases. Litigation of asbestos materials has been slow. Companies sometimes counter saying that health issues do not currently appear in their worker or workers, or sometimes are settled out of court.
The volume of the asbestos liability has concerned manufacturers and insurers and reinsurers. The amounts and method of allocating compensation have been the source of many court cases, and government attempts at resolution of existing and future cases.
In 1999 the United States considered but did not enact the Fairness in Asbestos Compensation Act. Between 1981 and the present, many asbestos companies have filed for bankruptcy. While companies filed for bankruptcy, this limited payouts to those who were actually affected by the material. Christopher Edley, Jr. commented what the 1999 act ultimately would have done if passed would be to "limit punitive damages that seek retribution for the decisions of long-dead executives for conduct that took place decades ago."
Litigation exists outside the United States in England, Scotland, Ireland, the Netherlands, France, Italy, and Japan among other nations (though the amounts awarded in these countries are not as large as in the US). See the companion article for further information.
In Australia a significant and controversial case was brought against the industrial building materials company James Hardie, which had mined and sold asbestos related products for many years.
Criticisms of asbestos regulation
Criticisms of regulation include the discredited suggestion by Dixy Lee Ray that the Space Shuttle Challenger disintegrated because the maker of O-ring putty was pressured by the EPA into ceasing production of asbestos-laden putty. However, the putty used in Challengers final flight contained asbestos, and failures in the putty were not responsible for the failure of the O-ring that led to loss of the shuttle.
Asbestos was also used in the first forty floors of the World Trade Center north tower causing an airborne contamination among lower Manhattan after the towers collapsed in the September 11 attacks. After the attack, another discredited suggestion came from Steven Milloy of the libertarian Cato Institute that the World Trade Center towers could still be standing or at least would have stood longer had a 1971 ban not stopped the completion of the asbestos coating above the 64th floor. This was not considered in the National Institute of Standards and Technology's report on the towers' collapse, on the basis that all fireproofing materials, regardless of their construction, are required to obtain a fire-resistance rating prior to installation, and all fiber-based lightweight commercial spray fireproofing materials are vulnerable to the dispersive effects of high speed/high energy impacts, as these are outside the fire testing upon which all ratings are based. Therefore, asbestos would have made little or no difference in preventing the towers' collapse, if used as fireproofing, and upon collapse any asbestos, however used, would still have been largely dispersed into the air within the massive dust cloud.
See also
Construction dust
Construction waste
Health impacts of sawdust
Metal dust
On-tool extraction
Particulates
Power tool
Renovation
Ultrafine particles
References
External links
About Your House – General Series – Asbestos
British Government Health and Safety Executive (HSE) essential guides
Hazards magazine's comprehensive asbestos resource pages
The Miracle Mineral Fiber – Asbestos
Asbestos: Magic mineral or deadly dust?, CBC Digital Archives
About Asbestos (2006), European Agency for Safety and Health at Work (OSHA)
A USGS map of "Naturally Occurring Asbestos" in Eastern America
Occupational exposure to asbestos and man-made vitreous fibres and risk of lung cancer: a multicenter case-control study in Europe, Rafael Carel et al.
Asbestos
Asbestos | Health impact of asbestos | [
"Environmental_science"
] | 7,290 | [
"Toxicology",
"Asbestos"
] |
53,031,776 | https://en.wikipedia.org/wiki/Stochastic%20thermodynamics |
Overview
When a microscopic machine (e.g. a MEM) performs useful work it generates heat and entropy as a byproduct of the process, however it is also predicted that this machine will operate in "reverse" or "backwards" over appreciable short periods. That is, heat energy from the surroundings will be converted into useful work. For larger engines, this would be described as a violation of the second law of thermodynamics, as entropy is consumed rather than generated. Loschmidt's paradox states that in a time reversible system, for every trajectory there exists a time-reversed anti-trajectory. As the entropy production of a trajectory and its equal anti-trajectory are of identical magnitude but opposite sign, then, so the argument goes, one cannot prove that entropy production is positive.
For a long time, exact results in thermodynamics were only possible in linear systems capable of reaching equilibrium, leaving other questions like the Loschmidt paradox unsolved. During the last few decades fresh approaches have revealed general laws applicable to non-equilibrium system which are described by nonlinear equations, pushing the range of exact thermodynamic statements beyond the realm of traditional linear solutions. These exact results are particularly relevant for small systems where appreciable (typically non-Gaussian) fluctuations occur. Thanks to stochastic thermodynamics it is now possible to accurately predict distribution functions of thermodynamic quantities relating to exchanged heat, applied work or entropy production for these systems.
Fluctuation theorem
The mathematical resolution to Loschmidt's paradox is called the (steady state) fluctuation theorem (FT), which is a generalisation of the second law of thermodynamics. The FT shows that as a system gets larger or the trajectory duration becomes longer, entropy-consuming trajectories become more unlikely, and the expected second law behaviour is recovered.
The FT was first put forward by and much of the work done in developing and extending the theorem was accomplished by theoreticians and mathematicians interested in nonequilibrium statistical mechanics.
The first observation and experimental proof of Evan's fluctuation theorem (FT) was performed by
Jarzynski equality
Seifert writes:
proved a remarkable relation which allows to express the free energy difference between two equilibrium systems by a nonlinear average over the work required to drive the system in a non-equilibrium process from one state to the other. By comparing probability distributions for the work spent in the original process with the time-reversed one, Crooks found a “refinement” of the Jarzynski relation (JR), now called the Crooks fluctuation theorem. Both, this relation and another refinement of the JR, the Hummer-Szabo relation became particularly useful for determining free energy differences and landscapes of biomolecules. These relations are the most prominent ones within a class of exact results (some of which found even earlier and then rediscovered) valid for non-equilibrium systems driven by time-dependent forces. A close analogy to the JR, which relates different equilibrium states, is the Hatano-Sasa relation that applies to transitions between two different non-equilibrium steady states.
This is shown to be a special case of a more general relation.
Stochastic energetics
History
Seifert writes:
Classical thermodynamics, at its heart, deals with general laws governing the transformations of a system, in particular, those involving the exchange of heat, work and matter with an environment. As a central result, total entropy production is identified that in any such process can never decrease, leading, inter alia, to fundamental limits on the efficiency of heat engines and refrigerators.
The thermodynamic characterisation of systems in equilibrium got its microscopic justification from equilibrium statistical mechanics which states that for a system in contact with a heat bath the probability to find it in any specific microstate is given by the Boltzmann factor. For small deviations from equilibrium, linear response theory allows to express transport properties caused by small external fields through equilibrium correlation functions. On a more phenomenological level, linear irreversible thermodynamics provides a relation between such transport coefficients and entropy production in terms of forces and fluxes. Beyond this linear response regime, for a long time, no universal exact results were available.
During the last 20 years fresh approaches have revealed general laws applicable to non-equilibrium system thus pushing the range of validity of exact thermodynamic statements beyond the realm of linear response deep into the genuine non-equilibrium region. These exact results, which become particularly relevant for small systems with appreciable (typically non-Gaussian) fluctuations, generically refer to distribution functions of thermodynamic quantities like exchanged heat, applied work or entropy production.
Stochastic thermodynamics combines the stochastic energetics introduced by with the idea that entropy can consistently be assigned to a single fluctuating trajectory.
Open research
Quantum stochastic thermodynamics
Stochastic thermodynamics can be applied to driven (i.e. open) quantum systems whenever the effects of quantum coherence can be ignored. The dynamics of an open quantum system is then equivalent to a classical stochastic one. However, this is sometimes at the cost of requiring unrealistic measurements at the beginning and end of a process.
Understanding non-equilibrium quantum thermodynamics more broadly is an important and active area of research. The efficiency of some computing and information theory tasks can be greatly enhanced when using quantum correlated states; quantum correlations can be used not only as a valuable resource in quantum computation, but also in the realm of quantum thermodynamics. New types of quantum devices in non-equilibrium states function very differently to their classical counterparts. For example, it has been theoretically shown that non-equilibrium quantum ratchet systems function far more efficiently then that predicted by classical thermodynamics. It has also been shown that quantum coherence can be used to enhance the efficiency of systems beyond the classical Carnot limit. This is because it could be possible to extract work, in the form of photons, from a single heat bath. Quantum coherence can be used in effect to play the role of Maxwell's demon though the broader information theory based interpretation of the second law of thermodynamics is not violated.
Quantum versions of stochastic thermodynamics have been studied for some time and the past few years have seen a surge of interest in this topic. Quantum mechanics involves profound issues around the interpretation of reality (e.g. the Copenhagen interpretation, many-worlds, de Broglie-Bohm theory etc are all competing interpretations that try to explain the unintuitive results of quantum theory) . It is hoped that by trying to specify the quantum-mechanical definition of work, dealing with open quantum systems, analyzing exactly solvable models, or proposing and performing experiments to test non-equilibrium predictions, important insights into the interpretation of quantum mechanics and the true nature of reality will be gained.
Applications of non-equilibrium work relations, like the Jarzynski equality, have recently been proposed for the purposes of detecting quantum entanglement and to improving optimization problems (minimize or maximize a function of multivariables called the cost function) via quantum annealing .
Active baths
Until recently thermodynamics has only considered systems coupled to a thermal bath and, therefore, satisfying Boltzmann statistics. However, some systems do not satisfy these conditions and are far from equilibrium such as living matter, for which fluctuations are expected to be non-Gaussian.
Active particle systems are able to take energy from their environment and drive themselves far from equilibrium. An important example of active matter is constituted by objects capable of self propulsion. Thanks to this property, they feature a series of novel behaviours that are not attainable by matter at thermal equilibrium, including, for example, swarming and the emergence of other collective properties. A passive particle is considered in an active bath when it is in an environment where a wealth of active particles are present. These particles will exert nonthermal forces on the passive object so that it will experience non-thermal fluctuations and will behave widely different from a passive Brownian particle in a thermal bath. The presence of an active bath can significantly influence the microscopic thermodynamics of a particle. Experiments have suggested that the Jarzynski equality does not hold in some cases due to the presence of non-Boltzmann statistics in active baths. This observation points towards a new direction in the study of non-equilibrium statistical physics and stochastic thermodynamics, where also the environment itself is far from equilibrium.
Active baths are a question of particular importance in biochemistry. For example, biomolecules within cells are coupled with an active bath due to the presence of molecular motors within the cytoplasm, which leads to striking and largely not yet understood phenomena such as the emergence of anomalous diffusion (Barkai et al., 2012). Also, protein folding might be facilitated by the presence of active fluctuations (Harder et al., 2014b) and active matter dynamics could play a central role in several biological functions (Mallory et al., 2015; Shin et al., 2015; Suzuki et al., 2015). It is an open question to what degree stochastic thermodynamics can be applied to systems coupled to active baths.
References
Notes
Citations
Academic references
Press
Statistical mechanics
Thermodynamics
Non-equilibrium thermodynamics
Branches of thermodynamics
Stochastic models | Stochastic thermodynamics | [
"Physics",
"Chemistry",
"Mathematics"
] | 1,980 | [
"Non-equilibrium thermodynamics",
"Statistical mechanics",
"Thermodynamics",
"Branches of thermodynamics",
"Dynamical systems"
] |
53,034,025 | https://en.wikipedia.org/wiki/C17H21N3O | {{DISPLAYTITLE:C17H21N3O}}
The molecular formula C17H21N3O may refer to:
RTI-126
Z3517967757 | C17H21N3O | [
"Chemistry"
] | 43 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
53,034,622 | https://en.wikipedia.org/wiki/Machine%20translation%20of%20sign%20languages | The machine translation of sign languages has been possible, albeit in a limited fashion, since 1977. When a research project successfully matched English letters from a keyboard to ASL manual alphabet letters which were simulated on a robotic hand. These technologies translate signed languages into written or spoken language, and written or spoken language to sign language, without the use of a human interpreter. Sign languages possess different phonological features than spoken languages, which has created obstacles for developers. Developers use computer vision and machine learning to recognize specific phonological parameters and epentheses unique to sign languages, and speech recognition and natural language processing allow interactive communication between hearing and deaf people.
Limitations
Sign language translation technologies are limited in the same way as spoken language translation. None can translate with 100% accuracy. In fact, sign language translation technologies are far behind their spoken language counterparts. This is, in no trivial way, due to the fact that signed languages have multiple articulators. Where spoken languages are articulated through the vocal tract, signed languages are articulated through the hands, arms, head, shoulders, torso, and parts of the face. This multi-channel articulation makes translating sign languages very difficult. An additional challenge for sign language MT is the fact that there is no formal written format for signed languages. There are notations systems but no writing system has been adopted widely enough, by the international Deaf community, that it could be considered the 'written form' of a given sign language. Sign Languages then are recorded in various video formats. There is no gold standard parallel corpus that is large enough for SMT, for example.
History
The history of automatic sign language translation started with the development of hardware such as finger-spelling robotic hands. In 1977, a finger-spelling hand project called RALPH (short for "Robotic Alphabet") created a robotic hand that can translate alphabets into finger-spellings. Later, the use of gloves with motion sensors became the mainstream, and some projects such as the CyberGlove and VPL Data Glove were born. The wearable hardware made it possible to capture the signers' hand shapes and movements with the help of the computer software. However, with the development of computer vision, wearable devices were replaced by cameras due to their efficiency and fewer physical restrictions on signers. To process the data collected through the devices, researchers implemented neural networks such as the Stuttgart Neural Network Simulator for pattern recognition in projects such as the CyberGlove. Researchers also use many other approaches for sign recognition. For example, Hidden Markov Models are used to analyze data statistically, and GRASP and other machine learning programs use training sets to improve the accuracy of sign recognition. Fusion of non-wearable technologies such as cameras and Leap Motion controllers have shown to increase the ability of automatic sign language recognition and translation software.
Technologies
VISICAST
http://www.visicast.cmp.uea.ac.uk/Visicast_index.html
eSIGN project
http://www.visicast.cmp.uea.ac.uk/eSIGN/index.html
The American Sign Language Avatar Project at DePaul University
http://asl.cs.depaul.edu/
Spanish to LSE
SignAloud
SignAloud is a technology that incorporates a pair of gloves made by a group of students at University of Washington that transliterate American Sign Language (ASL) into English. In February 2015 Thomas Pryor, a hearing student from the University of Washington, created the first prototype for this device at Hack Arizona, a hackathon at the University of Arizona. Pryor continued to develop the invention and in October 2015, Pryor brought Navid Azodi onto the SignAloud project for marketing and help with public relations. Azodi has a rich background and involvement in business administration, while Pryor has a wealth of experience in engineering. In May 2016, the duo told NPR that they are working more closely with people who use ASL so that they can better understand their audience and tailor their product to the needs of these people rather than the assumed needs. However, no further versions have been released since then. The invention was one of seven to win the Lemelson-MIT Student Prize, which seeks to award and applaud young inventors. Their invention fell under the "Use it!" category of the award which includes technological advances to existing products. They were awarded $10,000.
The gloves have sensors that track the users hand movements and then send the data to a computer system via Bluetooth. The computer system analyzes the data and matches it to English words, which are then spoken aloud by a digital voice. The gloves do not have capability for written English input to glove movement output or the ability to hear language and then sign it to a deaf person, which means they do not provide reciprocal communication. The device also does not incorporate facial expressions and other nonmanual markers of sign languages, which may alter the actual interpretation from ASL.
ProDeaf
ProDeaf (WebLibras) is a computer software that can translate both text and voice into Portuguese Libras (Portuguese Sign Language) "with the goal of improving communication between the deaf and hearing." There is currently a beta edition in production for American Sign Language as well. The original team began the project in 2010 with a combination of experts including linguists, designers, programmers, and translators, both hearing and deaf. The team originated at Federal University of Pernambuco (UFPE) from a group of students involved in a computer science project. The group had a deaf team member who had difficulty communicating with the rest of the group. In order to complete the project and help the teammate communicate, the group created Proativa Soluções and have been moving forward ever since. The current beta version in American Sign Language is very limited. For example, there is a dictionary section and the only word under the letter 'j' is 'jump'. If the device has not been programmed with the word, then the digital avatar must fingerspell the word. The last update of the app was in June 2016, but ProDeaf has been featured in over 400 stories across the country's most popular media outlets.
The application cannot read sign language and turn it into word or text, so it only serves as a one-way communication. Additionally, the user cannot sign to the app and receive an English translation in any form, as English is still in the beta edition.
Kinect Sign Language Translator
Since 2012, researchers from the Chinese Academy of Sciences and specialists of deaf education from Beijing Union University in China have been collaborating with Microsoft Research Asian team to create Kinect Sign Language Translator. The translator consists of two modes: translator mode and communication mode. The translator mode is capable of translating single words from sign into written words and vice versa. The communication mode can translate full sentences and the conversation can be automatically translated with the use of the 3D avatar. The translator mode can also detect the postures and hand shapes of a signer as well as the movement trajectory using the technologies of machine learning, pattern recognition, and computer vision. The device also allows for reciprocal communication because the speech recognition technology allows the spoken language to be translated into the sign language and the 3D modeling avatar can sign back to the deaf people.
The original project was started in China based on translating Chinese Sign Language. In 2013, the project was presented at Microsoft Research Faculty Summit and Microsoft company meeting. Currently, this project is also being worked by researchers in the United States to implement American Sign Language translation. As of now, the device is still a prototype, and the accuracy of translation in the communication mode is still not perfect.
SignAll
SignAll is an automatic sign language translation system provided by Dolphio Technologies in Hungary. The team is "pioneering the first automated sign language translation solution, based on computer vision and natural language processing (NLP), to enable everyday communication between individuals with hearing who use spoken English and deaf or hard of hearing individuals who use ASL." The system of SignAll uses Kinect from Microsoft and other web cameras with depth sensors connected to a computer. The computer vision technology can recognize the handshape and the movement of a signer, and the system of natural language processing converts the collected data from computer vision into a simple English phrase. The developer of the device is deaf and the rest of the project team consists of many engineers and linguist specialists from deaf and hearing communities. The technology has the capability of incorporating all five parameters of ASL, which help the device accurately interpret the signer. SignAll has been endorsed by many companies including Deloitte and LT-innovate and has created partnerships with Microsoft Bizspark and Hungary's Renewal. This technology is currently being used at Fort Bend Christian Academy in Sugar Land, Texas and at Sam Houston State University.
MotionSavvy
MotionSavvy was the first sign language to voice system. The device was created in 2012 by a group from Rochester Institute of Technology / National Technical Institute for the Deaf and "emerged from the Leap Motion accelerator AXLR8R." The team used a tablet case that leverages the power of the Leap Motion controller. The entire six person team was created by deaf students from the schools deaf-education branch. The device is currently one of only two reciprocal communication devices solely for American Sign Language. It allows deaf individuals to sign to the device which is then interpreted or vice versa, taking spoken English and interpreting that into American Sign Language. The device is shipping for $198. Some other features include the ability to interact, live time feedback, sign builder, and crowdsign.
The device has been reviewed by everyone from technology magazines to Time. Wired said, "It wasn't hard to see just how transformative a technology like [UNI] could be" and that "[UNI] struck me as sort of magical."Katy Steinmetz at TIME said, "This technology could change the way deaf people live." Sean Buckley at Engadget mentioned, "UNI could become an incredible communication tool."
References
Sign language
Applications of computer vision
Gesture recognition
Sign languages | Machine translation of sign languages | [
"Technology"
] | 2,068 | [
"Machine translation",
"Natural language and computing"
] |
53,034,689 | https://en.wikipedia.org/wiki/Cincinnati%20Water%20Maze | The Cincinnati Water Maze (CWM) is a type of water maze. Water mazes are experimental equipment used in laboratories; they are mazes that are partially filled with water, and rodents are put in them to be observed and timed as they make their way through the maze. Generally two sets of rodents are put through the maze, one that has been treated, and another that has not, and the results are compared. The experimenter uses this type of maze to learn about the subject's cognitive or emotional processes.
Overview
The Cincinnati Water Maze is a water maze that has nine interconnected T-intersections. The rats are forced to find their way from one end of the maze to the other by navigating through openings in the side of the walls rather than at the end of each passage. The walls are wide enough so that the rat cannot prop itself up on the wall, and the walls are made out of Plexiglas, to prevent the subjects from carrying out any unwanted behavior such as climbing over the wall, or finding seams in the walls to grab onto. These mazes are filled with water because rats are typically natural swimmers, but rats prefer not to be in the water, so it provides motivation for all the subjects to want to complete the maze.
This test can also be run in the dark if the researcher wants to have a greater focus on the subject's egocentric navigational abilities because if the rat cannot reference visual cues in the distance, it can not use the other type of reference based navigation, allocentric navigation. There are two parts of egocentric navigation that are evaluated, route-based navigation, a clearly defined path through an environment. The other part is path integrated navigation, the ability to take a different and more direct path to a starting location than the outbound path. Egocentric navigation is evaluated by observing the subjects and recording how many times the subject crosses a predetermined line at each T-intersection with their head and forepaws, indicating they are going in the wrong direction, or in other words, they are lost.
History
The predecessor to the Cincinnati Water Maze (CWM), the Biel Water Maze (BWM), was invented in 1940 by W. C. Biel to test rats’ egocentric navigational capabilities. As such, the BWM was enclosed within a container to prevent any external stimuli, such as light, from assisting the subject in completing the task. This ensures that the rat's memory from previous trials is the primary source of information. Moreover, the original design of the BWM had walls measuring just over a fifth of a meter in height, leaving approximately 20 cm of clearance between the top of the maze and the ceiling of the container. The design of the BWM was made so that each intersection formed a T-intersection.
Nevertheless, there were several concerns with the BWM, including the abundance of T-Intersections, which prompted the innovation that would result in the creation of the CWM. In contrast to the BWM, the CWM possesses wider channels to prevent larger rats from propping themselves up, and has the added benefit of asymmetry and extra intersections. Furthermore, the strategy that was predominantly seen in the BWM, where rats would swim in a straight line until forced to turn, was undone by the inherent asymmetry of the CWM. Instead, if the rats began at point-A, to arrive at point-B they would have to turn halfway down a corridor prior to reaching a dead end. Conversely, beginning at point-B towards point-A allows for the standard method previously mentioned.
Uses
The Cincinnati Water Maze was developed by Dr. Charles V. Vorhees. Many improvements were developed in collaboration with Dr. Michael T. Williams. The CWM is most often used to measure escape latency, which is the time required for the subject to escape the maze. Researchers may also measure the number of errors the subject makes, which are counted when the subject moves into the stem or arms of a dead-end cul-de-sac. The animal will typically be put in the same maze for 2 trials per day for 5 days if tested in the light and 18 or more days if tested in the dark, the goal being to assess the rat's procedural learning. The subject must learn the route as there is only one way out. Rats are given a 5-minute time limit if they cannot find the escape to prevent fatigue. By studying the escape latency and errors of the animal, researchers have a standardized test for the rate of learning in a subject. CWMs are especially useful because they are a direct test of egocentric learning/navigation. Without external visual cues, the rat is forced to remember the sequence of turns from previous trials to escape. This is useful for determining the effect of drugs on short-term memory egocentric learning. The test is also useful in mapping areas of the brain where spatial learning occurs by recording areas of brain activity during the test. In one variation, adding light, or other visual cues, researchers may measure allocentric learning/memory. With this procedure, the test becomes similar to the Morris Water Maze, where spatial learning is tested. Furthermore, in this variation, the rat is able to use both allocentric and egocentric cues to escape. This is particularly useful for studying spatial memory, as the rats are able to use both types of navigational cues. The CWM is not useful for mice. Mice do not have the cognitive ability to find the escape from such a complex maze. Further, the CWM must be preceded by a day of training in which they must learn to swim a simple straight water-filled channel from one end to the other for 4 trials. This allows one to measure swim speed to see that all groups are equal before entering the maze and to teach the rats that the submerged platform at the end is the escape. Without this prior training, there are high failure rates when rats were put into the CWM. Even with this training, when run under infrared light in the dark, it takes control rats 5–7 days to just begin to learn how to escape and 18–24 days to show mastery.
Analysis
Weaknesses
Since water mazes have been used mostly with rats and mice, the extrapolation of research data from these experiments to other organisms and humans is limited. The Cincinnati Water Maze (CWM) poses some limitations to experimenters as with all rodent tests, one must extrapolate to human egocentric/procedural learning and memory where different tests are used. For example, the element of water escape is different from using food restriction together with food or sweetened liquid as used in appetitive mazes. An advantage of water mazes is that they require less training than appetitive mazes, and if rats have pre-existing activity differences (if they are hyperactive or hypoactive in an open-field) those differences do not affect swimming and therefore do not influence maze performance. The CWM only measures route-based egocentric navigation when run in the dark, it does not measure the other component of egocentric navigation, that is, path integration, where a rat can learn a direct or short-cut path from the start to the goal as animals can do in some unstructured mazes. Another advantage of water mazes is that they are insensitive to body weight differences. Therefore, if an experimental treatment reduces the growth and body weight of one group compared with controls, it has little or no effect on water maze learning. Research has shown that the CWM has a steep learning curve compared to the Morris Water Maze; making the data collected on early trials less useful.
Comparison to other mazes
T-maze
Original T-mazes are very simple grounded mazes (dry) that present the rat with two options to choose from.
Allows the experimenter to make deductions of the cognitive decision-making abilities of the rats as well as look for patterns in the influence one decision will have on the other.
Multiple T-mazes help extrapolate the findings associated with right and wrong decision making, as many two choice decisions must be made consecutively to complete this kind of maze.
Y-maze
Very similar to the T-maze, the original Y-maze is a grounded maze with a simple two choice decision to be made.
Cognitive decision-making abilities the focus of the maze, similar to T-maze.
Y shape of maze has shown greater learning inclination, due to more gradual turns into choice options (Y shape instead of T).
Radial arm maze
An appetitive or water maze where the rat is positioned in the center of the maze with 8, 12, or 17 radiating arms at the dead of each is a reward if run appetitive after food restriction or an escape platform if run as a swimming maze.
Short-term memory is tested by how many times the animal goes down an arm more than once, hence, the learning is trial-dependent. Once it has entered an arm, it should not enter it again if it is to optimize getting rewards for each arm it visits. A variation of the radial-arm maze uses a mixture of some arms baited on every trial and some arms never baited. Visits to unbaited arms reflect reference memory errors whereas reentries to baited arms after the bait is taken represent working memory errors. The appetitive version can be used with rats or mice, the swimming version works only for rats.
The rat may be timed to see how long it takes to visit all the pathways; noting repeat visits to paths.
Morris water navigation task
The MWM is conducted in a circular pool of water that is featureless inside and has multiple distinctive cues outside. An animal is placed in water from a different start location on every trial and must find a hidden submerged platform to escape. The platform remains in the same position across trials. Latency, path length, and path efficiency (ratio of a straight line to the goal divided by the path length the animal swims) are measured using video tracking software. Animals are given multiple trials per day and this is called acquisition. At the end of acquisition, usually 24 hours later, the animal is given a probe trial to test reference memory with no platform present. Where the animal searches reflects its memory for where the platform used to be. Many experimenters then move the platform to the opposite quadrant and test cognitive flexibility in a reversal learning phase. Usually, the same number of trials and days are used for reversal as for acquisition with a reversal probe trial given 24 hours after the last reversal platform trial. Some add to this a shift phase that is similar to acquisition and reversal but with the platform moved to a new quadrant.
Rats are natural swimmers and learn the task well, but tank and platform size are important factors in determining task difficulty. Mice do best in pools 122 to 150 cm in diameter. Rats do best in pools of 183, 200-210 or even 244 cm in diameter. In rats, the larger pool sizes make the test more sensitive to spatial learning deficits. Trial length is typically limited to 90 to 120 seconds for rats to prevent fatigue. If an animal reaches the time limit, it is either placed on the platform by the experimenter or guided there, but guidance represents experimenter interference and is generally not recommended.
Rat has lots of free range in executing this maze. After all hidden platform trials are run, an important control procedure is to then conduct cued trials. For these curtains are closed around the pool to block line-of-sight access to distal cues and the platform is marked with a distinctive cue. For these trials both the start position of the animal around the perimeter and the location of the platform are changed on every trial to prevent the animal from using any residual distal cues, i.e., so that it cannot use spatial learning. The cued version relies on the animal used proximal rather than distal cues, and proximal cues are not hippocampus-dependent.
Drugs may be given to the rat to examine behavior in water and effect on motivation.
The MWM requires the rat to rely on multiple visual cues to triangulate the location of the platform no matter where it starts from on each trial. This requires the use of many allocentric cues as opposed to those used in simple T-mazes.
From this maze, one can observe if the rat is able to identify the correct location of the other platform by examining its search pattern.
The Cincinnati Water Maze (CWM) can be summarized as a combination of the mazes that can be used with or without distal cues present. The rats are faced with a much different challenge compared with simple T or Y-mazes due to the greater complexity of this maze. When the CWM is run in the dark it is extremely challenging for rats to learn but this complexity can reveal egocentric, striatal-related and perhaps lateral entorhinal cortex abnormalities since these are the regions associated with procedural learning and memory.
Each of the mazes centered on cognitive research are measured by observing the subject's ability to maneuver through the maze whether this be measured by time, number of trials and errors. Consistency from rat to rat in their ability to solve the maze task is important and allows scientists to then look for what may cause a deviation in performance in a certain rat, or groups of rats.
References
Animal testing mazes
Behavioral neuroscience
Laboratory rats | Cincinnati Water Maze | [
"Biology"
] | 2,740 | [
"Behavioural sciences",
"Behavior",
"Behavioral neuroscience"
] |
53,036,072 | https://en.wikipedia.org/wiki/Mu%20Librae | μ Librae (Latinised as Mu Librae) is the Bayer designation for a probable triple star system in the zodiac constellation of Libra. They have a combined apparent visual magnitude of 5.32, which is bright enough to be faintly visible to the naked eye. With an annual parallax shift of 13.71 mas, the system is located at an estimated distance of around 240 light years.
The inner pair consists of two A-type stars that, as of 2006, had an angular separation of 1.79 arc seconds along a position angle of 5.5°. They have an estimated physical separation of 139 AU. The primary, component A, is a visual magnitude 5.69 magnetic Ap star showing overabundances of the elements aluminum, strontium, chromium, and europium. Hence, it has a stellar classification of A1pSrEuCr. It is a photometric variable with periods of and . The surface magnetic field strength is 1,375 Gauss.
The secondary, component B, is an Am star with a stellar classification of A6m. It has a visual magnitude of 6.72. The tertiary member, component C, is a magnitude 14.70 star at an angular separation of 12.90 arc seconds along a position angle of 294°, as of 2000.
References
A-type main-sequence stars
Am stars
Libra (constellation)
Libra, Mu
BD-13 3986
130559
072489
5523
Ap stars | Mu Librae | [
"Astronomy"
] | 309 | [
"Libra (constellation)",
"Constellations"
] |
70,079,766 | https://en.wikipedia.org/wiki/Structural%20composite%20supercapacitor | Structural composite supercapacitors are multifunctional materials that can both bear mechanical load and store electrical energy. That when combined with structural batteries, could potentially enable an overall weight reduction of electric vehicles.
Typically, structural composite supercapacitors are based on the design of carbon fiber reinforced polymers. Carbon fibers act as mechanical reinforcement, current collectors, and eventually electrodes.
The matrix of a Structural composite supercapacitor is a polymer electrolyte that transfers load via shear mechanisms between the carbon fibers and has a reasonable ionic conductivity.
In a supercapacitor, the specific capacitance is proportional to the exact surface area of the electrodes. Structural carbon fibers usually have low specific surface area, and is therefore necessary to modify their surface to enable sufficient energy storage ability. To increase the surface area of the structural electrodes, several methods have been employed, mainly consisting in the modification of the surface of the carbon fiber itself, or by coating the carbon fiber through a material which covers its entire surface area.
Physical and chemical activation of the carbon fibers have increased their specific surface area by two orders of magnitude without damaging their mechanical properties, but have limited energy storage ability when combined with a structural polymer electrolyte. Coating carbon fibers with carbon nanotubes, carbon aerogel, or graphene nanoplatelets allowed for higher energy densities.
References
Capacitors
Energy conversion
Electric vehicles
Composite materials | Structural composite supercapacitor | [
"Physics"
] | 285 | [
"Physical quantities",
"Composite materials",
"Capacitors",
"Materials",
"Capacitance",
"Matter"
] |
70,080,199 | https://en.wikipedia.org/wiki/Polaris%20program | The Polaris program is a private spaceflight program organized by entrepreneur Jared Isaacman. Building on his experience as commander of the Inspiration4 mission—the first all-civilian spaceflight—Isaacman contracted with SpaceX to establish Polaris. The program involves two missions using SpaceX's Crew Dragon spacecraft and is planned to culminate in the first crewed launch on Starship.
Flights
Polaris Dawn
On 10 September 2024, The Polaris Dawn mission propelled Isaacman and his crew of three—Scott Poteet, Sarah Gillis and Anna Menon—to an elliptic orbit 1,400 kilometres (870 mi) away from Earth. This was farthest anyone had been from Earth since NASA's Apollo program. They passed through parts of the Van Allen radiation belt to study the health effects of space radiation and spaceflight on the human body. Later in the mission, with a lower apogee, Isaacman and Gillis successfully completed the first commercial spacewalk and tested the mobility and functionality of SpaceX's EVA spacesuit.
Mission II
The second mission in the Polaris Program will launch via a Falcon 9 Block 5 vehicle with a Crew Dragon capsule. SpaceX and Polaris had studied a crewed mission to lift the Hubble Space Telescope into a higher orbit to prevent it from burning up in the atmosphere, but this option was rejected by NASA in June 2024. Data obtained through Polaris Dawn will inform the objectives and timing of Mission II.
Mission III
The third Polaris mission was set to be the first crewed launch on Starship, SpaceX's next-generation launch system. Starship was in early flight testing as of December 2024 and was expected to carry crew after making at least 100 successful cargo flights, though this was not a firm requirement. This is the final listed flight of the Polaris Program.
See also
Timeline of private spaceflight
Notes
References
External links
Polaris Program photos on Flickr
2020s in spaceflight
2022 establishments in the United States
Human spaceflight programs
Private spaceflight
SpaceX
SpaceX Starship | Polaris program | [
"Engineering"
] | 417 | [
"Space programs",
"Human spaceflight programs"
] |
70,081,250 | https://en.wikipedia.org/wiki/Conscription%20of%20people%20with%20disabilities | Military conscription of people with disabilities has occurred on various occasions historically.
Cases
Below are listed known cases of the drafting of disabled persons.
In Japan during the Second Sino-Japanese War, more than 480 people with intellectual disabilities were conscripted.
In Ukraine during the Russian invasion of Ukraine, numerous people with a variety of disabilities have been drafted over the course of the conflict. The Ukrainian Defence Ministry amended the criteria for medical exemptions, reclassifying people with tuberculosis, viral hepatitis, thyroid disease and HIV to be fit for military service. In August 2024, it was reported that people with epilepsy had been recruited. On 22 October 2024, Ukrainian president Zelenskyy sign a decree which dissolved the medical examination commissions for determining the severity of disabilities that qualified for military exemptions.
In the United States during the Vietnam War, there was a disability draft under the Johnson Administration, called Project 100,000. Men who had previously been rejected from military service due to physical or mental disabilities were re-classified and sent to the frontlines in Vietnam.
In North Korea: The conscription physical examination has eased the criteria for military service suitability due to low height, reportedly to as of 2012.
See also
Conscription
Disability abuse
McNamara fallacy
Project 100,000
References
Conscription
Abuse
Disability | Conscription of people with disabilities | [
"Biology"
] | 258 | [
"Abuse",
"Behavior",
"Aggression",
"Human behavior"
] |
70,081,438 | https://en.wikipedia.org/wiki/Jean%20B%C3%A9nabou | Jean Bénabou (1932 – 11 February 2022) was a French mathematician, known for his contributions to category theory. He directed the Research Seminar in Category Theory at the Institut Henri Poincaré and Institut de mathématiques de Jussieu from 1969 to 2001.
Partial bibliography
References
External links
1932 births
2022 deaths
20th-century French mathematicians
Category theorists
Moroccan emigrants to France
People from Rabat
University of Paris alumni
External links | Jean Bénabou | [
"Mathematics"
] | 90 | [
"Category theorists",
"Mathematical structures",
"Category theory"
] |
70,081,751 | https://en.wikipedia.org/wiki/Aircraft%20Research%20Association | The Aircraft Research Association (ARA) is an aerodynamics research institute in the north-west of Bedford.
History
The association was founded on 22 January 1952. 14 main British aviation companies funded £1.25m to build a large wind tunnel.
It was first proposed in 1953 to build the site at Stevington, north-east of Bedford. By March 1953, the current site was chosen.
Construction
Work started on Monday 7 September 1953.
The wind tunnel was fabricated by Moreland Hayne of east London.
The transonic tunnel first ran in April 1956.
Visits
The Duke of Edinburgh visited on the morning of Friday 4 May 1956. He had been planning to land by helicopter in the south-east of Bedford, and to be driven from there to the site by car, but weather conditions were unsuitable.
Structure
The site has the largest transonic wind tunnel in the UK, known as the TWT, with speeds up to Mach 1.4, powered by a Sulzer axial compressor. It is 25,000 hp electric-powered.
Wind tunnels
Supersonic tunnel, Mach 1.4 - 3.5, built in 1958
Two hypersonic tunnels
Mach 4-5 tunnel, built in 1965
Mach 7 tunnel, built in 1968
Research
Projects worked on include Concorde, the Harrier and most Airbus aircraft. The Rolls-Royce RB211 was tested there.
The site now works with RUAG of Switzerland.
See also
Aerospace Technology Institute, in Bedfordshire, launched in 2012 by the government as the UK Aerodynamics Centre
British Hydromechanics Research Association (BHRA), also in Bedfordshire
UK Aerospace Research Consortium (UK-ARC), formed in 2018, an alliance of university departments
List of wind tunnels
References
External links
ARA Bedford
1952 establishments in the United Kingdom
Aerospace engineering organizations
Aerospace industry in the United Kingdom
Engineering research institutes
Organisations based in Bedford
Research institutes established in 1952
Science and technology in Bedfordshire
Technology consortia
Wind tunnels | Aircraft Research Association | [
"Engineering"
] | 385 | [
"Aeronautics organizations",
"Aerospace engineering organizations",
"Engineering research institutes",
"Aerospace engineering"
] |
70,082,080 | https://en.wikipedia.org/wiki/Max%20Dresden | Max Dresden (April 23, 1918, Amsterdam – October 29, 1997, Palo Alto) was a Dutch-American theoretical physicist and historian of physics. He is known for his research in "statistical mechanics, superconductivity, quantum field theory, and elementary particle physics."
Biography
Dresden studied at the University of Amsterdam and at the University of Leiden, where he received the Dutch equivalent of an M.S. in 1938 and was a research assistant of H. A. Kramers. Kramers helped him get a studentship research position in 1939 at Columbia University under the supervision of Enrico Fermi. Dresden received his Ph.D. in 1946 from the University of Michigan. His thesis On the Problem of the Approach to Equilibrium in Statistical Mechanics was supervised by George Uhlenbeck. In 1949 Dresden became a US citizen.
He was from 1946 to 1957 a faculty member of the physics department of the University of Kansas, where he was eventually promoted to full professor. At Northwestern University he was from 1957 to 1960 a professor and chair of the physics department. He was a professor from 1960 to 1964 at the University of Iowa and then from 1964 until his retirement in 1989 at the State University of New York at Stony Brook (SUNY), where he headed the Institute for Theoretical Physics. He won four teaching awards at Stony Brook. After his retirement as professor emeritus, he was from 1989 at SLAC a visiting scientist and at Stanford University a consulting professor in the history of physics. At various times during his career he held visiting positions at Fermilab, the Johns Hopkins University, the Argonne National Laboratory, the CERN, and the Niels Bohr Institute in Copenhagen.
Dresden was elected a fellow of the American Association for the Advancement of Science in 1989. His doctoral students include James T. Cushing, Martin Gutzwiller, Paul Halpern, and Jorge Zanelli.
He was married twice and had four children.
Selected publications
Articles
Chapter 8. Non-equilibrium statistical mechanics or the vagaries of time evolution by Max Dresden, pages 585–633 in Laurie Brown, Abraham Pais, Brian Pippard (editors) Twentieth Century Physics, Vol. 1, 1995, IOP Publishing/AIP Press
Chapter. On personal styles and tastes in physics by Max Dresden, in C.S. Liu, S.T. Yau (editors) Chen Ning Yang: a great physicist of the 20th century, International Press 1995
Books
H.A. Kramers: Between Tradition and Revolution, Springer 1987 ; 2012 ebook ebook
as editor with Lillian Hoddeson and Laurie Brown: Pions to quarks: Particle physics in the 1950s, Cambridge University Press 1989
as editor with Lillian Hoddeson, Laurie Brown, and Michael Riordan: The rise of the Standard Model: Particle physics in the 1960s and 1970s, Cambridge University Press 1997 (with an introduction by Hoddeson on The rise of the standard model 1964–1979, pp. 3–35) hbk ; pbk
References
External links
Leiden University alumni
University of Michigan faculty
University of Kansas faculty
Northwestern University faculty
University of Iowa faculty
Stony Brook University faculty
Fellows of the American Association for the Advancement of Science
20th-century Dutch physicists
20th-century American physicists
Theoretical physicists
1918 births
1997 deaths | Max Dresden | [
"Physics"
] | 666 | [
"Theoretical physics",
"Theoretical physicists"
] |
70,082,501 | https://en.wikipedia.org/wiki/List%20of%20applications%20of%20stainless%20steel | Stainless steel is used in a multitude of fields including architecture, art, chemical engineering, food and beverage manufacture, vehicles, medicine, energy and firearms.
Architecture
The use of stainless steel in buildings can be both practical and aesthetic. In vogue during the Art Deco period, the most famous use of stainless steel can be seen in the upper portion of the Chrysler Building. Thanks to its durability, many of these buildings have retained their original appearance.
Stainless steel is used in the construction of modern buildings, such as the exterior of the Petronas Twin Towers and the Jin Mao Building. The Parliament House of Australia in Canberra has a stainless steel flagpole weighing over . The largest stainless steel building in North America is the aeration building in the Edmonton Composting Facility. La Geode in Paris has a dome composed of 6433 polished stainless steel triangles that form the sphere that reflects the sky. The development of high-strength stainless steel grades, such as "lean duplex" grades, has led to increasing use in structural applications.
Thanks to its low reflectivity, stainless steel is used as a roofing material for airports, which prevents pilots from being dazzled. It is also used for its ability to keep the surface of the roof close to ambient temperature. Examples of such airports include the Sacramento International Airport in California and the Hamad International Airport in Qatar.
Stainless steel is used for pedestrian and road bridges in the form of tubes, plates, or reinforcing bars. Examples include: the Cala Galdana Bridge in Menorca, the first stainless steel road bridge to be built; the Champlain Bridge in Montreal; the Oudesluijs bridge in Amsterdam, a bridge made using Construction 3D printing; the Padre Arrupe Bridge in Bilbao, which links the Guggenheim Museum Bilbao to the University of Deusto. the Sant Fruitos Pedestrian Bridge in Spain; Stonecutter's Bridge, Hong Kong; and The Helix Bridge, a pedestrian bridge in Singapore.
Art and monuments
Americas
Cloud Gate, a sculpture by Anish Kapoor. (Chicago, United States)
Gateway Arch (pictured) is clad entirely in stainless steel: 886 tons (804 metric tons) of plate, #3 finish, type 304 stainless steel. (St. Louis, United States)
Jaime Latapí López's Cristo de Chiapas. Created in 2007. (Tuxla Guttierez, Mexico)
Metamorphosis by David Černỳ. Created in 2011 (Charlotte, United States)
Unisphere, constructed as the theme symbol of the 1964 New York World's Fair, is constructed of Type 304L stainless steel as a spherical framework with a diameter of . (New York City, United States)
United States Air Force Memorial has an austenitic stainless steel structural skin. (Arlington, United States)
Asia
The Blossom pavilion by Zhan Wang. Created in 2015. (Shanghai, China)
Europe
Worker and Kolkhoz Woman by Vera Mukhina. Created in 1937. (Moscow, Russia)
The aluminium cladding of the spheres and tubes of the Atomium was renovated with stainless-steel cladding in 2006. (Brussels, Belgium)
Juraj Jánošík monument (Terchova, Slovakia)
La Danse de la fontaine émergente by Chen Zhen. Created in 2008. (Paris, France)
Man of Steel, currently under construction. (Rotherham, England)
The Sibelius Monument is made entirely of stainless steel tubes (Helsinki, Finland)
Sun Voyager by Jon Gunnar Arnason, . Created in 1990. (Reykjavik, Iceland)
The Big Elk by Linda Bakke. Created in 2015. (Stor-Elvdal, Norway)
The Kelpies (Falkirk, Scotland)
A Sea of Steel consists of fourteen steel sculptures by different artists. (Wijk aan Zee, the Netherlands)
Water
Stainless steels have a long history of application in contact with water due to their excellent corrosion resistance. Applications include a range of conditions including plumbing, potable water and wastewater treatment, desalination, and brine treatment. Types 304 and 316 stainless steels are standard materials of construction in contact with water. However, with increasing chloride contents, higher alloyed stainless steels such as Type 2205 and super austenitic and super duplex stainless steels are used.
Important considerations to achieve optimum corrosion performance are:
the correct grade choice for the chloride content of the water;
avoidance of crevices when possible by good design;
adherence to good fabrication practices, particularly removing weld heat tint;
prompt drainage after hydrotesting.
The use of stainless steel piping has helped to reduce the losses of drinking water in Tokyo, Seoul, and Taipei.
Pulp, paper, and biomass conversion
Stainless steels are used extensively in the pulp and paper industry to avoid iron contamination of the product and because of their corrosion resistance to the various chemicals used in the papermaking process. For example, duplex stainless steels are used in digesters to convert wood chips into wood pulp. 6% Mo superaustenitics are used in the bleach plant and Type 316 is used extensively in the paper machine.
Chemical and petrochemical processing
Stainless steels are used extensively in the chemical and petrochemical industries for their corrosion resistance to aqueous, gaseous, and high-temperature environments, their mechanical properties at all temperatures, and occasionally for other special physical properties.
Food and beverage
Austenitic (300 series) stainless steel, particularly Types 304 and 316, is the material of choice for the food and beverage industry, though martensitic and ferritic (400 series) steels are also used. Stainless steels are advantageous because they do not affect the taste of the product, are easily cleaned and sterilized to prevent bacterial contamination of the food, and are durable. Within the food and beverage industry, stainless steel is extensively used in cookware, commercial food processing, commercial kitchens, brewing beer, winemaking, and meat processing.
Stainless steel's superiority over plastic in preserving flavor is reportedly why McDonald's traditionally procures soft drink syrup for its soda fountains from The Coca-Cola Company in stainless steel tanks, rather than the bag-in-box technology preferred by most fast food restaurant chains.
Acidic foods with high salt additions, such as tomato sauce, and highly salted condiments, such as soy sauce, may require higher-alloyed stainless steels such as 6% Mo superaustenitics to prevent pitting corrosion by chloride.
Vehicles
Automobiles
The Allegheny Ludlum Corporation worked with Ford on various concept cars with stainless steel bodies from the 1930s through the 1970s to demonstrate the material's potential. The 1957 and 1958 Cadillac Eldorado Brougham had a stainless steel roof. In 1981 and 1982, the DMC DeLorean production automobile used Type 304 stainless steel body panels over a glass-reinforced plastic monocoque. Intercity buses made by Motor Coach Industries are partially made of stainless steel. The aft body panel of the Porsche Cayman model (2-door coupe hatchback) is made of stainless steel. Due to the Cayman's many curves and angles, it was discovered during early body prototyping that conventional steel could not be formed without cracking. Thus, Porsche was forced to use stainless steel. The body of the Tesla Cybertruck, which went into production in 2023, is composed of 300-series stainless steel.
The largest use of stainless steel in cars is the exhaust line. Environment protection requirements aimed at reducing pollution and noise for the entirety of a car's lifespan led to the use of ferritic stainless steels (typically AISI409/409Cb in North America, EN1.4511 and 1.4512 in Europe). They are used for collector, tubing, muffler, catalytic converter, tailpipe. Heat-resisting grades EN1.4913 or 1.4923 are used in parts of turbochargers, while other heat-resisting grades are used for exhaust gas recirculation and for inlet and exhaust valves. In addition, common rail injection systems and their injectors rely on stainless steels.
Stainless steel has proved to be the best choice for miscellaneous applications, such as stiffeners for windshield wiper blades, balls for seat belt operation device in case of accident, springs, fasteners, etc.
Some automotive manufacturers use stainless steel as decorative highlights in their vehicles.
Light commuter trains
Stainless steel is now used as one of the materials for tramlinks, together with aluminium alloys and carbon steel. Duplex grades tend to be preferred thanks to their corrosion resistance and higher strength, allowing a reduction of weight and a long life in maritime environments.
Passenger rail cars
Rail cars have commonly been manufactured using corrugated stainless steel panels for additional structural strength. This was particularly popular during the 1960s and 1970s but has since declined. One notable example was the early Pioneer Zephyr. Notable former manufacturers of stainless steel rolling stock included the Budd Company (USA), which has been licensed to Japan's Tokyu Car Corporation, and the Portuguese company Sorefame. Many railcars in the United States are still manufactured with stainless steel. In India, where rail infrastructure is developing, new stainless steel coaches in being put into service. South Africa is also commissioning stainless steel coaches.
Aircraft
Budd also built two airplanes, the Budd BB-1 Pioneer and the Budd RB-1 Conestoga, out of stainless steel tube and sheet. The first, which had fabric wing coverings, is on display at the Franklin Institute, being the longest continuous display of an aircraft ever, since 1934. The RB-2 was almost all stainless steel, save for the control surfaces. One survives at the Pima Air & Space Museum, adjacent to Davis–Monthan Air Force Base.
The American Fleetwings Sea Bird amphibious aircraft of 1936 was also built using a spot-welded stainless steel hull.
Due to its thermal stability, the Bristol Aeroplane Company built the all-stainless steel Bristol 188 high-speed research aircraft, which first flew in 1963. However, the practical problems encountered meant that later high-speed aircraft, such as the Concorde, employed aluminium alloys. The experimental Mach 3 American bomber, the XB70 Valkyrie, made extensive use of stainless steel in its external structure due to the extreme heat encountered at those high speeds.
The Mikoyan-Gurevich MiG-25 interceptor aircraft was built predominantly out of stainless steel due to the Soviet Union's inability to mass-produce an aircraft made from lightweight titanium, the only other way found to protect from the extreme kinetic heating. It severely hindered the aircraft's flight performance and the MiG-25 had to be kept extremely secret to prevent the NATO allies from finding out about the realities of the aircraft's performance. It however holds the world altitude record for aircraft, at ~123,000 feet.
The use of stainless steel in mainstream aircraft is hindered by its excessive weight compared to other materials, such as aluminium.
Spacecraft
Stainless steel (SS) also has an application in spaceflight. The early Atlas rockets used stainless steel in their fuel tanks. The tank structure of the Centaur upper stage of the Atlas V and Vulcan Centaur launchers uses SS.
The outer cladding of the modules and the Integrated Truss Structure of the International Space Station use stainless steel alloys.
Components of the Space Launch System use SS..
Both stages of SpaceX Starship are largely made of type 300 SS.
Medicine
Surgical tools and medical equipment are usually made of stainless steel, because of its durability and ability to be sterilized in an autoclave. In addition, surgical implants such as bone reinforcements and replacements (e.g. hip sockets and cranial plates) are made with special alloys formulated to resist corrosion, mechanical wear, and biological reactions in vivo.
Stainless steel is used in a variety of applications in dentistry. It is common to use stainless steel in many instruments that need to be sterilized, such as needles, endodontic files in root canal therapy, metal posts in root canal-treated teeth, temporary crowns and crowns for deciduous teeth, and arch wires and brackets in orthodontics. Surgical stainless steel alloys (e.g., 316 low-carbon steel) were also used in some early dental implants.
Energy
Stainless steels are extensively used in all types of power stations, from nuclear to solar. Stainless steels are ideally suited as mechanical supports for power generation units when the permeation of gases or liquids are required, such as filters in cooling water or hot gas clean up or as structural supports in electrolytic power generation.
Stainless steel is used in electrolysers (proton exchange membranes and solid oxide electrolysers being the most common) that convert electrical energy into hydrogen gas by water electrolysis. Conversely, stainless steel is used in fuel cells which perform the opposite reaction, combining hydrogen and oxygen to produce water and electrical energy.
Culinary
Stainless steel is often preferred for kitchen sinks because of its ruggedness, durability, heat resistance, and ease of cleaning. In better models, acoustic noise is controlled by applying resilient undercoating to dampen vibrations. The material is also used for cladding of surfaces such as appliances and backsplashes.
Cookware and bakeware may be clad in stainless steels to enhance their cleanability and durability and to permit their use in induction cooking (this requires a magnetic grade of stainless steel, such as 432). Because stainless steel is a poor conductor of heat, it is often used as a thin surface cladding over a core of copper or aluminium, which conducts heat more readily.
Cutlery is often made of stainless steel, for low corrosion, ease of cleaning, negligible toxicity, and ability to avoid flavoring the food by electrolytic activity.
Jewelry
Stainless steel is used for jewelry and watches, with 316L being the type commonly used. Oxidizing stainless steel briefly gives it radiant colors that can also be used for coloration effects.
Firearms
Some firearms incorporate stainless steel components as an alternative to blued or parkerized steel. Some handgun models, such as the Smith & Wesson Model 60 and the Colt M1911 pistol, can be made entirely from stainless steel. This gives a high-luster finish similar in appearance to nickel plating. Unlike plating, the finish is not subject to flaking, peeling, wear-off from rubbing (as when repeatedly removed from a holster), or rust when scratched.
3D printing
Some 3D printing providers have developed proprietary stainless steel sintering blends for use in rapid prototyping. One popular stainless steel grade used in 3D printing is 316L stainless steel. Due to the high temperature gradient and fast rate of solidification, stainless steel products manufactured via 3D printing tend to have a more refined microstructure; this, in turn, results in better mechanical properties. However, stainless steel is not as commonly used as materials like Ti6Al4V, due to the availability of more cost-effective traditional manufacturing methods for stainless steel.
References
Building materials
Chromium alloys
English inventions
1916 introductions
Roofing materials
Biomaterials
Science-related lists | List of applications of stainless steel | [
"Physics",
"Chemistry",
"Engineering",
"Biology"
] | 3,092 | [
"Biomaterials",
"Building engineering",
"Architecture",
"Construction",
"Materials",
"Alloys",
"Medical technology",
"Chromium alloys",
"Matter",
"Building materials"
] |
70,082,772 | https://en.wikipedia.org/wiki/Flick%20Stick | Flick Stick is a video game control scheme designed for gyroscopic game controllers. The Flick Stick control scheme is primarily designed for 3D shooter games with the intent of bringing the perceived advantages of mouse aiming to controllers, while addressing shortcomings of traditional first-person shooter controller schemes.
Flick Stick was designed by game developer Julian "Jibb" Smart in 2018. In 2020, it was integrated into Steam as an option within Steam Input. Multiple commercial games, such as Counter-Strike: Global Offensive, Fortnite, Deathloop, and Call of Duty: Modern Warfare II (and by extension, Call of Duty: Warzone 2.0) have since added Flick Stick as an alternate control scheme.
Design
In a traditional first-person shooter controller scheme, the right analog stick is used to steer the player character's view in the direction the stick is tilted. A "sensitivity" slider determines the speed the player turns when the analog stick is held. As the player can't turn faster than the highest sensitivity value allows, controller aiming with a traditional control scheme is generally slower than aiming with a mouse.
In a typical Flick Stick control scheme, the player's view snaps to the direction the right analog stick is held, with "up" representing the player's current view (no change). Tilting the stick left will "flick" the player's view 90 degrees to the left, and tilting the stick down will turn the player a full 180 degrees. Once the analog stick is held down, it can be rotated along the gate to turn the player in tandem. The analog stick only affects the horizontal view axis, and all vertical aiming is performed through the controller's gyroscope by tilting the controller in the desired direction. The right analog stick is intended to be used for quick turns, and the gyro is used for precise aiming.
In explaining Flick Stick's design, designer Jibb Smart claimed that analog sticks are "too small" for precise aiming; instead, by treating gyro aim "as a mouse", players would enjoy a higher degree of precision than in traditional control schemes. By reserving the right analog stick for fast sweeping motions, Smart claimed that players will have "more freedom to respond to threats from any direction than even a traditional mouse on a big mousepad".
History
In 2015, Nintendo released Splatoon, a third-person shooter where gyro aiming is the primary method of input. Splatoon intrigued Smart, as the game demonstrated the viability of gyro aiming as a legitimate competitor to traditional control schemes. Following Splatoon'''s release, Smart would go on to create "JoyShockMapper", a tool which translates gyroscopic controller movements into mouse input, enabling gyro input in PC games which don't formally support it.
Flick Stick functionality was first implemented into an early 2018 prototype of JoyShockMapper, and was included in the program's public 1.0.0 release early the following year. In July 2020, Valve Software integrated Flick Stick as an option in Steam Input, allowing Steam games to be played with Flick Stick controls without the use of external programs.
In July 2021, the Devolver Digital-published game Boomerang X became the first commercial game to natively support Flick Stick. In December of that same year, the control scheme was implemented into Counter-Strike: Global Offensive. In February 2022, Epic Games collaborated with Jibb Smart to officially integrate Flick Stick into Fortnite. In September 2022, Arkane Lyon collaborated with Jibb Smart to implement Flick Stick into the PS5 & PC versions of Deathloop. Call of Duty: Modern Warfare II and Call of Duty: Warzone 2.0'' added Flick Stick in their respective Season 2 updates.
References
External links
Flick Stick on GyroWiki
Video game control methods | Flick Stick | [
"Technology"
] | 795 | [
"Computing terminology",
"Video game terminology"
] |
70,083,745 | https://en.wikipedia.org/wiki/Shind%C5%8D%20temple%20ruins | The , is an archaeological site with the ruins of a Hakuhō period Buddhist temple and roof tile kiln remnants located in the Midorigaoka-cho and Nakano-cho neighborhoods of the city of Tondabayashi, Osaka, Japan. The temple and kilns no longer exists, but the loctations were collectively designated as a National Historic Site in 2002 together with the Okameishi Kofun.
Overview
The Shindō temple ruins are located on a river terrace formed by Ishikawa, a tributary of the Yamato River at the foot of the Habikino hill in the southern part of the Osaka Plain. It has been known since the early twentieth century as a ruined temple site, as old roof tiles were scattered on ground, but it was not excavated until 1959. At that time, the foundation of four buildings rebuilt during the Hakuhō period were confirmed, and the foundations of a pagoda to the south. The layout of structures was patterned after Shitennō-ji in Osaka, with the Middle Gate, Pagoda, Main Hall and Lecture Hall all lined up in a row from south-to-north, with the cloiser connecting from the sides of the Middle Gate to the sides of the Lecture Hall, forming a courtyard which encloses the Pagoda and Main Hall. During the Tenpyō era (729-749), the temple was expanded, adding a South Gate, and additional East and West buildings connected to the cloister. The temple does not appear in historical documentation, so its true and history are unknown.
The Oganji-ike Tile Kiln Ruins is a semi-underground stepless climbing kiln located on the northeastern bank of Oganji Pond, about 500 meters northwest of the ruins of the Shindō Temple ruins.
The temple site is about a 20-minute walk from Tondabayashi Station on the Kintetsu Railway Kintetsu Nagano Line.
See also
List of Historic Sites of Japan (Osaka)
References
External links
Tondabayashi city home page
Tondabayashi, Osaka
Kawachi Province
Asuka period
Historic Sites of Japan
Buddhist archaeological sites in Japan
Japanese pottery kiln sites | Shindō temple ruins | [
"Chemistry",
"Engineering"
] | 445 | [
"Kilns",
"Japanese pottery kiln sites"
] |
70,084,116 | https://en.wikipedia.org/wiki/The%20Bottle%20Houses | The Bottle Houses in Prince Edward Island (PEI), also known as the symphony of color and light, was built in 1980 by Edouard Arsenault. It is made of hundreds of recycled colored glass bottles, a popular tourist site in PEI. Bottle wall construction is the process of building a structure, usually housing, with glass or plastic bottles and a binding material. This sustainable building type helps reduce the chances of bottles dumped at landfills and promotes reuse of "waste" material. The bottle houses on the Island have many benefits to the locals and visitors, such as; its aesthetic style, low cost of production to renewable resource architecture and sustainability (8).
Introduction
Architecture today pushes the notion of creating buildings that are sustainable and resilient, whether it be by reducing non-renewable resources needed to keep the building running, using passive architectural methods to retire the use of electricity and fuel or by conserving water. Several organizations, such as Leeds, BREEAM, and Energy Star have been put in place to promote sustainability and hold designers accountable for the long-term goal of sustaining the planet for future generations. The Bottle house on Prince Edward Island- P.E.I., designed by Edward Arsenault in 1980, portrays sustainable architecture in a unique way. It promotes the use of recycled materials, glass bottles in this case, to create three resilient structures that not only create shelters but euphoric moments for the people of the community and tourists which visit the spaces.
History
Bottle wall construction is the process of building a structure, usually housing, with glass or plastic bottles and binding material. This sustainable building type helps reduce the chances of bottles being dumped at landfills and promotes the reuse of "waste" material. Its benefits range from aesthetic style, low cost of production to renewable architecture and sustainability[ii], carrying out the three steps of effective waste management; reduce, reuse, and recycle. Bottle house construction has been present since ancient Rome, the very first was constructed by William F. Peck in Tonopah, Nevada. At the time these houses were not constructed for aesthetic purposes like they are today, they were appreciated due to their ability to reduce the load of the upper levels of houses & reduce the amount of concrete needed. The building was made with 10,000 bottles of J. Hostetter's Stomach Bitters, medicine bottles that were initially reused by being refilled with glop and resold by shady dealers. The demand for this type of vernacular architecture arose due to the short supply of construction materials and the rising population levels in the area. Peck took it upon himself to construct these buildings to tackle the housing demand-supply issue in the town, using mortar as a binding element, lime as an interior finish and the bottles as insulators to keep the homes warm in the harsh winter.
Bottle House, Prince Edward Island
The inspiration for the Bottle House, P.E.I. was taken from another glass house in British Columbia. By 1980, Edouard Arsenault had already built three of his structures which have become a tourist landmark for the locals in the Cape Egmont community. He sourced his bottles from various trash sites around him and even began to get his communities support as they began to donate their bottles to help his project. They were built from the ground up and bound with cement to form the shape of houses. As light shines through them they create kaleidoscopic patterns and stained-glass colors on the floor, creating a magical and euphoric feeling for the visitors that enter the space, as to why it's named "the symphony of color and light"
Life of Edouard Arsenault
Edouard Arsenault, the architect of the bottle village, was born in 1914 to Emmanuel and Roseline Arsenault. He spent most of his time in Cap-Egmont before he moved to the United Kingdom to serve in the second world war. He started off as a fisherman, a protégé under his father, then he began to fix up and construct boats. In 1948 he married Rosina Leclerc who later bore his first two children; Yvette and Rejanee, they all lived in the Cap-Egmont lighthouse where he served as the resident lighthouse keeper till the lighthouse became automated, and they moved onto the grounds of the current bottle houses in P.E.I. Roseline bore two more kids; Maurice and Pierre there. During his retirement from being the Lighthouse keeper he had the vision to create the Bottle houses which consist of a six-gable house, a tavern and a chapel, however, the chapel was only completed after his death.
The glass village
He received the inspiration to design the houses after receiving a postcard from his daughter in 1979 of a glass castle in British Columbia which she had visited. He began to collect over 25,000 recycled bottles from the community and dumps to build the spaces. After he retrieved them, he spent the winter in the basement cleaning the bottles, removing the labels, and planning the project, which he began to build in 1980 at the age of 66. The bottle house village houses a six-gabled house, tavern, chapel, gift shop and a replica of the lighthouse he worked in. The gable house was built at using about 12,000 bottles that formed the three main sections. Arsenault carefully picked the size and colors of the bottles to create unique patterns on the building's façade as well as in the rooms when light shines through them. He built it by cementing 300 to 400 bottles per row, using about 85 bags of cement, the binding material, over a six-month period before it was finally open to the public in 1981 Then he designed the hexagon shaped tavern in 1982, later rebuilt in 1993, which only used 8,000 bottles, the harsh winter conditions called for the rebuilding of the Tavern, the initial roof and the central cylinder were able to be salvaged. The third building built was the Chapel in 1983, made with 10,000 bottles. The building during a sunset would shine colorful streams in from behind the altar, creating a feeling of peace for the guests as they take in the atmosphere of the site.
The garden and site
The buildings sit around several Acadian gardens, trees, a pond, and bottle tree structures. It also sits by a wood carved structure of a woman's face, a local gift shop, and a miniature replica of the lighthouse Arsenault tended to before his retirement. Apart from constructing the buildings Arsenault carried out the gardening and landscaping on the site. He spent his time after retiring planting trees on the site, laying out the stonework and designing the flower beds. His Acadian roots prompted his commitment to developing the Cap-Egmont, Evangeline area; he dedicated his retirement to designing artefacts that made his home community special and unique, "radiating a symphony of sunlight-powered colors in a tranquil garden setting with a goldfish pond and a fountain" to create a space for tourists to enjoy nature and the serene sounds of the water. The views captured from the site are of the ocean, and a mini replica of the Cape-Egmont Lighthouse that he tended.
Construction process
The bottles were sourced from various trash sites around the town and from the community as they began to donate their own bottles to help the project. They were built from the ground up, bound with cement to form the shape of houses. As light shines through them they create kaleidoscopic patterns and stained glass colors on the cement floor, creating a magical and euphoric feeling for the visitors that enter the space, as to why it's named "the symphony of color and light".
Advantages of vernacular architecture
The bottle wall or bottle house technique provides various advantages for the glass houses, sustainability, aesthetics, cost-effective waste management, and bulletproof. In terms of aesthetics the bottle house construction is beneficial for a small community like the Cape-Egmont community, it becomes a unique attraction which brings in tourists and improves the GDP of the country. Its structural components consist of the binder, typically a motor or clay and glass bottles making them structurally sound and stable and can resist bullet shots. Cost-effective waste management- millions of water and wine bottles are discarded yearly into landfills so reusing this material turns these discarded bottles into eco bricks which save cost and reduce the levels of energy that is consumed producing concrete. Arsenault's artefacts brought life and a personality to the city bringing its locals and visitors together to witness a unique and significant moment, the bottle house village. The building is not only effective for its sustainable qualities but the site as well which promotes healthy living within nature as well as taking care of your environment and the community.
References
External links
Wikipedia Student Program
Bottle houses
Roadside attractions in Canada
Acadian culture
Buildings and structures in Prince County, Prince Edward Island
1980 establishments in Canada | The Bottle Houses | [
"Engineering"
] | 1,811 | [
"Bottle houses",
"Architecture"
] |
70,084,450 | https://en.wikipedia.org/wiki/Revolutionary%20coalition | In psychology, the term revolutionary coalition describes the formation of a within a larger group with the purpose of altering or disrupting existing authority structures. These efforts also typically aim for “a radical and pervasive change in the functioning and structure of the group or organization.”
Formation
Revolutionary coalitions form through the resistance against or the escape from authority's influence within a group. Members of one group assert themselves against a perceived imbalance of power in favor of other group members. This perception typically commences at an individual level. It only leads to subgroup formations if other low-power members of the group feel a sense of shared identity.
Experiments
In one study, members of triads were asked to work under the directions of a leader who had been chosen based on scores on a bogus test of abilities. They were compensated through monetary rewards given out by the leader. The leader was asked to keep more than half of the money earned by the entire group and give each group member less than one-fourth of total earnings. Group members were informed about whether the leader had personally decided how to distribute payment. 58% of participants formed a revolutionary coalition with other low-group members if the leader had personally decided, compared to 25% of group members revolting if the leader had not personally decided.
Another study investigated how collective performance and coalition strength within groups of three could affect the redistribution of status prerogatives. For each triad, hierarchy was established through high control status of one group member and low control status of the two others. Through the performance of ambiguous decision-making tasks over two trials, researchers observed how the two members, acting together as a revolutionary coalition, could potentially damage the outcomes received by the high-status member. They found that the formation of a revolutionary coalition could only reallocate prerogatives if it is supported by a joint effect of collective performance and coalition strength.
References
Psychological concepts
Group processes
Conformity | Revolutionary coalition | [
"Biology"
] | 388 | [
"Behavior",
"Conformity",
"Human behavior"
] |
70,084,843 | https://en.wikipedia.org/wiki/Brian%20Argrow | Brian Maurice Argrow is an American aerospace engineer and Professor in the Department of Aerospace Engineering Sciences at the University of Colorado Boulder. Currently, he serves as the Chair of the department. Argrow specializes in the field of hypersonic aerodynamics, rarefied gas dynamics, dense gas dynamics, and UAVs.
Early life and education
Argrow was born to parents Essie Argrow and Lavonne Davis in Oklahoma where he attended Stroud High School. Following high school, Argrow graduated from the University of Oklahoma (OU) on the Dean's Honor Roll in 1983. Upon graduating with his Bachelor's degree, he spent three months with Aerospace Engineering Support in El Segundo, California before pursuing his Master's degree. He then returned to the University of Oklahoma for his Master of Science degree and PhD, where he earned the 1989 national Black Engineer of the Year Award in the student leadership category.
Career
Upon completing his PhD, Argrow accepted an assistant professor position at the University of Oklahoma's School of Aerospace and Mechanical Engineering from 1989 to 1992. He left OU in 1992 to accept a similar faculty position at the University of Colorado Boulder's (CU Boulder) Ann and H.J. Smead Department of Aerospace Engineering Sciences. Upon joining the faculty, Argrow's research team was the first to verify the method of osculating cones for supersonic waverider design. He also created a shock tube to create uniform static initial conditions near 800 °F to explore non-classical dense gas dynamics. As a result of his research, Argrow was the 2000 recipient of the President's Teaching Scholar.
In 2004, Argrow became the founding director of the Research and Engineering Center for Unmanned Vehicles (RECUV) at CU Boulder. In this role, Argrow continued to monitor hurricanes while collaborating with Erik Rasmussen through the Norman-based National Severe Storms Laboratory. He also served in various leadership roles outside of CU Boulder including co-chairing the first Symposium for Civilian Applications of Unmanned Aircraft Systems and serving on the NASA Advisory Council's Unmanned aerial vehicle Subcommittee. In 2007, Argrow was appointed the associate dean for education in the College of Engineering and Applied Science. Two years later, he was one of the leaders of the Verification of the Origins of Rotation in Tornadoes Experiment 2, the largest scientific study of twisters in history. In this role, he helped track the formation of tornados through the central Great Plains by co-developing an unmanned aerial vehicle to fly into the middle of the storm.
Argrow's research team later collaborated with researchers at the University of Nebraska–Lincoln to intercept supercells with an Unmanned Aerial Systems for the first time. Through funding from the National Severe Storms Laboratory (NSSL), Argrow's research team flew a UAS across northeast Colorado to collect sample outflows from several supercells. In 2014, Argrow completed a semester sabbatical at the National Oceanic and Atmospheric Administration NSSL at the National Weather Center. Upon returning from his sabbatical, Agrow was elected a Fellow of the American Institute of Aeronautics and Astronautics as someone who had contributed and advanced the aerospace industry. A few years later, he was named the inaugural holder of the Schaden Leadership Chair in Aerospace Engineering Sciences.
In February 2022, Argrow was elected a Member of the National Academy of Engineering for "contributions to unmanned aerial systems capable of penetrating severe storms and leadership in their application to scientific observation."
Personal life
Argrow and his wife Gwen have one daughter together.
References
External links
Living people
Aerospace engineers
University of Colorado Boulder faculty
University of Oklahoma alumni
Fellows of the American Institute of Aeronautics and Astronautics
Members of the United States National Academy of Engineering
Year of birth missing (living people) | Brian Argrow | [
"Engineering"
] | 773 | [
"Aerospace engineers",
"Aerospace engineering"
] |
70,084,973 | https://en.wikipedia.org/wiki/James%20Kay%20Graham%20Watson | Jim Watson, FRS, (20 April 1936—18 December 2020) who published under the name J.K.G. Watson, was a molecular spectroscopist most well known for the development of the widely used molecular Hamiltonians named after him (sometimes called "Watsonians" or "Watson Hamiltonians"). These Hamiltonians are used to describe the quantum dynamics of molecules.
Education and career
Watson did his Ph.D. at the University of Glasgow, and worked in the UK, United States and Canada. He was a postdoctoral fellow under Jon Hougen in the Molecular Spectroscopy Group of Gerhard Herzberg at the National Research Council of Canada in Ottawa, Ontario from 1963 to 1965. He eventually joined the staff in the group in 1982 where he remained until retirement.
Watson published a number of papers in which he developed and applied molecular Hamiltonians to problems in spectroscopy. In 1968 Watson published Simplification of the molecular vibration-rotation Hamiltonian, in which he presented a practical framework for the quantum-mechanical description of molecular ro-vibrational dynamics within the Born–Oppenheimer approximation.
Honors and awards
He was a Fellow of the Royal Society, the Royal Society of Canada and the American Physical Society. He received the 1986 Earle K. Plyer Prize for Molecular Spectroscopy and Dynamics from the American Physical Society. The citation reads:
"For his numerous fundamental contributions to the theory of rovibronic interactions in molecules, especially the development of the universally used Watson Hamiltonian for vibration-rotation energy levels, the unified treatment of centrifugal distortion in molecules, the elucidation of forbidden rotational transitions in spherical tops, the application of advanced symmetry arguments to perturbations in external fields, and investigations of the Jahn-Teller effect in H_3 and NH_4."
Personal life
Watson was married to Carolyn Kerr. He died in his home in New Edinburgh after a brief illness on 17 December 2020 at the age of 84.
References
1930s births
2020 deaths
Fellows of the Royal Society
Fellows of the Royal Society of Canada
Fellows of the American Physical Society
Spectroscopists
Academics of the University of Glasgow | James Kay Graham Watson | [
"Physics",
"Chemistry"
] | 432 | [
"Physical chemists",
"Spectrum (physical sciences)",
"Analytical chemists",
"Spectroscopists",
"Spectroscopy"
] |
70,087,251 | https://en.wikipedia.org/wiki/Fairfield%20Enterprises | Fairfiel Enterprises was a leading British-based machine distributor and supplier of tooling and support services to the printing and packaging industries. The company was taken over in 2000 by the Swiss company Bobst AG, a supplier of machinery and services to the packaging industry.
History
The business was founded in London in 1884 by the Jewish-German immigrant Oscar Friedheim (1858–1928), at first trading in the supply of cardboard and paper. Five years later the company turned to the import and distribution of machinery, starting with a German made card cutting and scoring machine for the production of visiting cards. From there on Oscar Friedheim focused on building up its connections with overseas machine manufacturers in the paper and packaging industry (e. g. Bobst, Faber & Schleicher, Muller Martini and after the Second World War Winkler + Dünnebier).
In 1913 the company was incorporated as a limited company with a nominal capital of £17,000. During The Blitz its head office in Water Lane was hit hard twice. Most of the machinery and the company records got destroyed. Therefor a new provisional office had to be set up at Mill Hill. 1948 Oscar Friedheim Ltd. bought the engineers and sundries business of John Haddon & Co, a London based printing and advertising company.
In 1970 Fairfield Enterprises Ltd. was created as a holding company of Oscar Friedheim Ltd. To extend its business into spare parts Fairfield bought 50% of Lasercomb Dies Ltd. (Redditch) in 1984 and purchased the remaining 50% in 1991.
In August 1997 Fairfield was listed on the London Stock Exchange at 80p per share to raise funds for acquisitions. In 1998 Fairfield bought Palatine Engraving (Leeds) and Kennedy Grinding (London). In 1999 the headquarters of Fairfield Enterprises was moved from London to Redditch.
In 2000 Bobst AG of Switzerland acquired Fairfield Enterprises, paying 200p per Share. Fairfield's activities concerning the distribution of Bobst machinery in the UK and Ireland were renamed Bobst UK Holdings Ltd. The remaining parts of Fairfield, Friedheim International and Lasercomb Group (including Palatine Engraving), were sold to their management in 2005 and 2006 respectively.
References
Further reading
Roy Brewer: Friedheim - A Century of Service - 1884–1984, Oscar Friedheim Ltd, London 1984.
External links
Homepage of Friedheim International
Homepage of Lasercomb Group
British companies established in 1884
1884 establishments in England
Companies based in London
Distribution companies of the United Kingdom
Business services companies of the United Kingdom
Papermaking in the United Kingdom
Stationers of the United Kingdom
Packaging industry
Printing devices
Companies formerly listed on the London Stock Exchange
2000 mergers and acquisitions
History of London
Economy of the City of London | Fairfield Enterprises | [
"Physics",
"Technology"
] | 541 | [
"Physical systems",
"Machines",
"Printing devices"
] |
70,087,334 | https://en.wikipedia.org/wiki/Alcyoneus%20%28galaxy%29 | Alcyoneus is a low-excitation, Fanaroff–Riley class II radio galaxy located from Earth, with host galaxy SDSS J081421.68+522410.0. It is located in the constellation Lynx and it was discovered in Low-Frequency Array (LOFAR) data by a team of astronomers led by Martijn Oei. As of 2024, it has the second-largest extent of radio structure of any radio galaxy identified, with lobed structures spanning across, described by its discoverers at the time as the "largest known structure of galactic origin." It has since been superseded by another radio galaxy, Porphyrion, with lobed structures of .
Aside from the size of its radio emissions, the central galaxy is otherwise of ordinary radio luminosity, stellar mass, and supermassive black hole mass. It is a standalone galaxy with an isophotal diameter at 25.0 r-mag/arcsec2 of about , with the nearest cluster located 11 million light-years away from it. The galaxy was named after the giant Alcyoneus from Greek mythology.
Discovery
Alcyoneus was first reported in a paper published in February 2022 by Martijn Oei and colleagues after obtaining results from the Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS), an interferometric radio survey of the Northern Sky, as part of a search that resulted in the discovery of over 8,000 new giant radio galaxies. The object was first observed as a bright, three-component radio structure visible on at least four spatial resolutions of the LoTSS (6-, 20-, 60- and 90-arcsecond resolutions). The two outer components of the radio structure are separated by a similar distance to the smaller, elongated radio structure, signifying their nature as possible radio lobes. Further confirmations using radio-optical overlays dismiss the possibility of the two being separate radio lobes from different galaxies, and confirm that they have been produced by the same source.
Characteristics
Alcyoneus has been described as a giant radio galaxy, a special class of objects characterized by the presence of radio lobes generated by relativistic jets powered by the central galaxy's supermassive black hole. Giant radio galaxies are different from ordinary radio galaxies in that they can extend to much larger scales, reaching upwards to several megaparsecs across, far larger than the diameters of their host galaxies. In the case of Alcyoneus, the host galaxy does not host a quasar and is relatively quiescent, with spectral imaging from the Sloan Digital Sky Survey's 12th data release (SDSS DR12) suggesting a star formation rate of only 0.016 solar masses per year (). This classifies it as a low excitation radio source, with Alcyoneus obtaining most of its energy due to the relativistic process of the central galaxy's jet rather than radiation from its active galactic nucleus.
The central host galaxy of Alcyoneus has a stellar mass of 240 billion solar masses (), with its central supermassive black hole estimated to have a mass of million solar masses (); both typical for elliptical galaxies, but substantially lower than for similar galaxies generating giant radio sources.
It is currently unknown how Alcyoneus's radio emissions grew so large. One explanation proposes that the radio galaxy's cosmic web environment might be less dense than that of other giant radio galaxies, leading to a lower resistance to growth. In comparison to other known giant radio galaxies, Alcyoneus does not appear to have a particularly massive stellar population or central black hole, or particularly powerful jet streams.
See also
List of largest galaxies
Hercules A
Cygnus A
List of galaxies with notable features
Notes
References
Radio galaxies
Active galaxies
Astronomical radio sources
Lynx (constellation) | Alcyoneus (galaxy) | [
"Astronomy"
] | 792 | [
"Astronomical radio sources",
"Lynx (constellation)",
"Astronomical events",
"Constellations",
"Astronomical objects"
] |
70,089,080 | https://en.wikipedia.org/wiki/Network-In-a-Box | A Network-In-a-Box (NIB) is the combination of multiple components of a computer network into a single device (a 'box'), which are traditionally separated into multiple devices.
Examples
In 2021, the company Genie launched a 5G Network-In-a-Box to run as an on-premises service.
In August 2021, Tecore Networks launched a 5G Network-In-a-Box, which also supported 5G and LTE.
5G Network-in-a-Box systems are widely available for broadcasters, sports leagues, event organizers, public safety agencies and armed forces.
History
In 2014, an open-source hardware Network-In-a-Box based on OpenBTS was deployed in West-Papua, Indonesia.
References
Computer networking | Network-In-a-Box | [
"Technology",
"Engineering"
] | 160 | [
"Computer networking",
"Computer engineering",
"Computer network stubs",
"Computer science",
"Computing stubs"
] |
70,089,217 | https://en.wikipedia.org/wiki/Facebook%20content%20management%20controversies | Facebook and Meta Platforms have been criticized for their management of various content on posts, photos and entire groups and profiles. This includes but is not limited to allowing violent content, including content related to war crimes, and not limiting the spread of fake news and COVID-19 misinformation on their platform, as well as allowing incitement of violence against multiple groups.
Intellectual property infringement
Facebook has been criticized for having lax enforcement of third-party copyrights for videos uploaded to the service. In 2015, some Facebook pages were accused of plagiarizing videos from YouTube users and re-posting them as their own content using Facebook's video platform, and in some cases, achieving higher levels of engagement and views than the original YouTube posts. Videos hosted by Facebook are given a higher priority and prominence within the platform and its user experience (including direct embedding within the News Feed and pages), giving a disadvantage to posting it as a link to the original external source. In August 2015, Facebook announced a video-matching technology aiming to identify reposted videos, and also stated its intention to improve its procedures to remove infringing content faster. In April 2016, Facebook implemented a feature known as "Rights Manager", which allows rights holders to manage and restrict the upload of their content onto the service by third-parties.
Violent content
In 2013, Facebook was criticized for allowing users to upload and share videos depicting violent content, including clips of people being decapitated. Having previously refused to delete such clips under the guideline that users have the right to depict the "world in which we live", Facebook changed its stance in May, announcing that it would remove reported videos while evaluating its policy. The following October, Facebook stated that it would allow graphic videos on the platform, as long as the intention of the video was to "condemn, not glorify, the acts depicted", further stating that "Sometimes, those experiences and issues involve graphic content that is of public interest or concern, such as human rights abuses, acts of terrorism, and other violence. When people share this type of graphic content, it is often to condemn it. If it is being shared for sadistic pleasure or to celebrate violence, Facebook removes it." However, Facebook once again received criticism, with the Family Online Safety Institute saying that such videos "crossed a line" and can potentially cause psychological damage among young Facebook users, and then-Prime Minister of the United Kingdom David Cameron calling the decision "irresponsible", citing the same concerns regarding young users. Two days later, Facebook removed a video of a beheading following "worldwide outrage", and while acknowledging its commitment to allowing people to upload gory material for the purpose of condemnation, it also stated that it would be further strengthening its enforcement to prevent glorification. The company's policies were also criticized as part of these developments, with some drawing particular attention to Facebook's permission of graphic content but potential removal of breastfeeding images. In January 2015, Facebook announced that new warnings would be displayed on graphic content, requiring users to explicitly confirm that they wish to see the material.
War crimes
Facebook has been criticized for failing to take down violent content depicting war crimes in Libya. A 2019 investigation by the BBC found evidence of alleged war crimes in Libya being widely shared on Facebook and YouTube. The BBC found images and videos on social media of the bodies of fighters and civilians being desecrated by fighters from the self-styled Libyan National Army. The force, led by General Khalifa Haftar, controls a swathe of territory in the east of Libya and is trying to seize the capital, Tripoli. BBC Arabic found almost one hundred images and videos from Libya shared on Facebook and YouTube, in violation of their companies' guidelines. The UK Foreign Office said it took the allegations extremely seriously and is concerned about the impact the recent violence is having on the civilian population.
In 2017, a Facebook video of Libyan National Army (LNA) special forces commander Mahmoud al-Werfalli was uploaded showing him shooting dead three captured fighters. The video was then shared on YouTube over ten thousand times. The International Criminal Court used it as evidence to indict al-Werfalli for the war crime of murder. The BBC found the original video was still on Facebook two years after his indictment and also discovered videos showing the bodies of civilians being desecrated. These were taken in Ganfouda, a district of Benghazi which was under siege by the LNA between 2016 and 2017. More than 300 people, including dozens of children died during the siege. A video uncovered by BBC Arabic showed soldiers mocking a pile of corpses of dead civilians and trampling on bodies. Among them was a 77-year-old woman, Alia Hamza. Her son, Ali Hamza, had five family members killed in Ganfouda.
Ali Hamza told BBC Arabic, "I sent links to lawyers to send to the ICC in the Hague against Khalifa Haftar and his military commanders regarding the massacres of civilians", said Hamza. In the video, the LNA soldiers label the civilians as terrorists. Human rights lawyer and war crimes specialist Rodney Dixon QC reviewed the evidence BBC Arabic found. "If groups are using those platforms to propagate their campaigns then those platforms should seriously look at their role because they could then be assisting in that process of further crimes being committed", he said. After presenting our findings to Facebook they removed all the videos that show a suspected war crime taking place. However, they opted not to suspend any of the accounts which we found linked to the images. Erin Saltman, Facebook's policy manager for counterterrorism in Europe, Middle East and Africa, told BBC Arabic, "Sometimes there are very conflicting narratives of whether or not the victim is a terrorist, or whether it's a civilian over who's committing that act, we cannot be the pure arbiters of truth." But Facebook and YouTube's own community guidelines explicitly prohibit content that promotes or depicts acts of violence.
Facebook Live
Facebook Live, introduced in August 2015 for celebrities and gradually rolled out for regular users starting in January 2016, lets users broadcast live videos, with Facebook's intention for the feature to be presenting public events or private celebrations. However, the feature has been used to record multiple crimes, deaths, and violent incidents, causing significant media attention.
Facebook has received criticism for not removing videos faster, and Facebook Live has been described as a "monster [Facebook] cannot tame" and "a gruesome crime scene for murders". In response, CEO Mark Zuckerberg announced in May 2017 that the company would hire 3,000 moderators to review content and invest in tools to remove videos faster.
Pro-anorexia groups
In 2008, Facebook was criticized for hosting groups dedicated to promoting anorexia. The groups promoted dramatic weight loss programs, shared extreme diet tips, and posted pictures of emaciated girls under "Thinspiration" headlines. Members reported having switched to Facebook from Myspace, another social networking service, due to a perceived higher level of safety and intimacy at Facebook. In a statement to BBC News, a Facebook spokesperson stated that "Many Facebook groups relate to controversial topics; this alone is not a reason to disable a group. In cases where content is reported and found to violate the site's terms of use, Facebook will remove it."
Pro-mafia groups' case
In Italy in 2009, the discovery of pro-mafia groups, one of them claiming Bernardo Provenzano's sainthood, caused an alert in the country and brought the government to rapidly issue a law that would force Internet service providers to deny access to entire websites in case of refused removal of illegal contents. The amendment was passed by the Italian Senate and now needs to be passed unchanged by the Chamber of Deputies to become effective.
Facebook criticized the government's efforts, telling Bloomberg that it "would be like closing an entire railway network just because of offensive graffiti at one station", and that "Facebook would always remove any content promoting violence and already had a takedown procedure in place."
Trolling
On March 31, 2010, The Today Show ran a segment detailing the deaths of three separate adolescent girls and trolls' subsequent reactions to their deaths. Shortly after the suicide of high school student Alexis Pilkington, anonymous posters began trolling for reactions across various message boards, referring to Pilkington as a "suicidal CUSS", and posting graphic images on her Facebook memorial page. The segment also included an exposé of a 2006 accident, in which an eighteen-year-old student out for a drive fatally crashed her father's car into a highway pylon; trolls emailed her grieving family the leaked pictures of her mutilated corpse.
There have been cases where Facebook "trolls" were jailed for their communications on Facebook, particularly memorial pages. In Autumn 2010, Colm Coss of Ardwick, Britain, was sentenced to 26 weeks in jail under s127 of the Communications Act 2003 of Great Britain, for "malicious communications" for leaving messages deemed obscene and hurtful on Facebook memorial pages.
In April 2011, Bradley Paul Hampson was sentenced to three years in jail after pleading guilty to two counts of using a carriage service (the Internet) to cause offense, for posts on Facebook memorial pages, and one count each of distributing and possessing child pornography when he posted images on the memorial pages of the deceased with phalluses superimposed alongside phrases such as "Woot I'm dead".
Rape pages
A series of pro-rape and "rape joke" content on Facebook drew attention from the media and women's groups. Rape Is No Joke (RINJ), a group opposing the pages, argued that removing "pro-rape" pages from Facebook and other social media was not a violation of free speech in the context of Article 19 of the Universal Declaration of Human Rights and the concepts recognized in international human rights law in the International Covenant on Civil and Political Rights.
RINJ repeatedly challenged Facebook to remove the rape pages. RINJ then turned to advertisers on Facebook telling them not to let their advertising be posted on Facebook's 'rape pages'.
Following a campaign that involved the participation of Women, Action and the Media, the Everyday Sexism Project and the activist Soraya Chemaly, who were among 100 advocacy groups, Facebook agreed to update its policy on hate speech. The campaign highlighted content that promoted domestic and sexual violence against women, and used over 57,000 tweets and more than 4,900 emails to create outcomes such as the withdrawal of advertising from Facebook by 15 companies, including Nissan UK, House of Burlesque and Nationwide UK. The social media website initially responded by stating that "While it may be vulgar and offensive, distasteful content on its own does not violate our policies", but then agreed to take action on May 29, 2013, after it had "become clear that our systems to identify and remove hate speech have failed to work as effectively as we would like, particularly around issues of gender-based hate".
Child abuse images
In June 2015, the UK National Society for the Prevention of Cruelty to Children raised concerns about Facebook's apparent refusal when asked to remove controversial video material which allegedly showed a baby in emotional distress.
In March 2017, BBC News reported in an investigation that Facebook only removed 18 of the 100 groups and posts it had reported for containing child exploitation images. The BBC had been granted an interview with Facebook policy director Simon Milner under the condition that they provide evidence of the activity. However, when presented with the images, Facebook canceled the interview, and told the BBC that it had been reported to the National Crime Agency for illegally distributing child exploitation images (the NCA could not confirm whether the BBC was actually being investigated). Milner later stated to the BBC that the investigation had exposed flaws in its image moderation process that have since been addressed, and that all of the reported content was removed from the service.
According to data from the National Center for Missing & Exploited Children in 2020, there have been 20 million reported incidents of child sexual abuse material on Facebook. This accounted for 95% of total incidents recorded by the organization, while Google accounted for half a million incidents, Snapchat for 150,000 and Twitter for 65,000.
Objectification of women
In July 2017, GMA News reported that "a number" of secret Facebook groups that had been engaging in illegal activity of sharing "obscene" photos of women had been exposed, with the Philippine National Bureau of Investigation warning group members of the possibility of being liable for violating child pornography and anti-voyeurism laws. Facebook stated that it would remove the groups as violations of its community guidelines. A few days later, GMA News had an interview with one of the female victims targeted by one of the groups, who stated that she received friend requests from strangers and inappropriate messages. After reporting to authorities, the Philippine National Police's anti-cybercrime unit promised to take action in finding the accounts responsible. Senator Risa Hontiveros responded to the incidents with the proposal of a law that would impose "stiff penalties" on such group members, stating that "These people have no right to enjoy our internet freedom only to abuse our women and children. We will not allow them to shame our young women, suppress their right to express themselves through social media and contribute to a culture of misogyny and hate".
Violation of Palestinian human rights
According to the study commissioned by Meta and carried out by Business for Social Responsibility (BSR), Facebook and Instagram's policies during Israeli attacks on the Gaza Strip in 2021 harmed the fundamental human rights of Palestinians. The social media giant had denied Palestinian users their freedom of expression by erroneously removing their content. BSR's report is yet another indictment of the company's ability to police its global public square and to balance freedom of expression against the potential for harm in a tense international context.
Anti-Semitism
Facebook has been suspected of having a double standard when it comes to pages and posts regarding the Arab–Israeli conflict. When it comes to alleged incitement, Facebook has been accused of being unfair, removing only posts and pages that attack Palestinians, while turning a blind eye to similar posts that are violently antisemitic. The NGO Shurat Hadin-Israel Law Center conducted an experiment over the incitement issue, which sought to expose what it viewed as double standards regarding anti-Israel sentiment vis-a-vis the simultaneous launch of two Facebook pages: "Stop Palestinians" and "Stop Israel". Following the launch of the two nearly identical pages, the NGO posted hateful content simultaneously on both pages. Next, Shurat Hadin reported both faux-incitement pages to Facebook to see which, if either, would be removed. According to them, despite featuring nearly identical content, only one was removed from the online platform. They said the page inciting against Palestinians was closed by Facebook (on the same day that it was reported) for "containing credible threat of violence" which "violated our [Facebook's] community standards", but not the page inciting against Israelis. Shurat Hadin said that Facebook claimed that this page was "not in violation of Facebook's rules". Shurat Hadin's staged anti-Israel group "Stop Israel" still remains active on Facebook. ProPublica stated in September 2017 that a website was able to target ads at Facebook users who were interested in "how to burn Jew" and "Jew hater". Facebook removed the categories and said it would try to stop them from appearing to potential advertisers.
In March 2019, Facebook subsidiary Instagram declined to remove an anti-semitic image posted by right-wing conspiracy theorist Alex Jones, saying that it did not violate their community standards.
Incitement of violence against Israelis
Facebook has been accused of being a public platform that is used to incite violence. In October 2015, 20,000 Israelis claimed that Facebook was ignoring Palestinian incitement on its platform and filed a class-action suit demanding that Facebook remove all posts "containing incitement to murder Jews".
Israeli politicians have complained that Facebook does not comply or assist with requests from the police for tracking and reporting individuals when they share their intent to kill or commit any other act of violence on their Facebook pages. In June 2016, following the murder of Hallel Ariel, 13, by a terrorist who posted on Facebook, Israeli Minister of Public Security Gilad Erdan charged that "Facebook, which has brought a positive revolution to the world, has become a monster ... The dialogue, the incitement, the lies of the young Palestinian generation are happening on the Facebook platform." Erdan accused Facebook of "sabotaging the work of Israeli police" and "refusing to cooperate" when Israel police turns to the site for assistance. It also "sets a very high bar" for removing inciting content.
In July 2016, a civil action for $1 billion in damages was filed in the United States District Court for the Southern District of New York on behalf of the victims and family members of four Israeli-Americans and one US citizen killed by Hamas militants since June 2014. The victims and plaintiffs in the case are the families of Yaakov Naftali Fraenkel, a 16-year-old who was kidnapped and murdered by Hamas operatives in 2014; Taylor Force, a 29-year-old American MBA student and US Army veteran killed in a stabbing spree in Jaffa in 2016; Chaya Braun, a three-month-old thrown from her stroller and slammed into the pavement when a Hamas attacker drove his car into a light rail station in Jerusalem in an October 2014; 76-year-old Richard Lakin who was killed in the October 2015 shooting and stabbing attack on a Jerusalem bus; and Menachem Mendel Rivkin, who was seriously wounded in a January 2016 stabbing attack in Jerusalem. The plaintiffs claimed that Facebook knowingly provided its social media platform and communication services to Hamas in violation of provisions of US Anti-Terrorism laws which prohibits US businesses from providing any material support, including services, to designated terrorist groups and their leaders. The government of the United States has designated Hamas as a "Foreign Terrorist Organization" as defined by US law. The suit claims that Hamas "used and relied on Facebook's online social network platform and communications services to facilitate and carry out its terrorist activity, including the terrorist attacks in which Hamas murdered and injured the victims and their families in this case". The legal claim was rejected; the court found that Facebook and other social media companies are not considered to be the publishers of material users post when digital tools used by the company match content with what the tool identifies as interested consumers.
In August 2016, Israel's security service, the Shin Bet, reported that it had arrested nine Palestinians who had been recruited by the Lebanon-based Hezbollah terrorist organization. Operatives of Hezbollah in Lebanon and Gaza Strip recruited residents of the West Bank, Gaza and Israel through Facebook and other social media sites. After recruiting cell leaders on Facebook, Hezbollah and the recruits used encrypted communications to avoid detection, and the leaders continued to recruit other members. The terror cells received Hezbollah funding and planned to conduct suicide bombings and ambushes and had begun preparing explosive devices for attacks, said the security service, which claimed credit for preventing the attacks. The Shin Bet said it also detected multiple attempts by Hezbollah to recruit Israeli Arabs through a Facebook profile.
On October 16, 2023, singer and internet personality Dalal Abu Amneh was arrested by the Israeli Police for allegedly promoting hate speech and inciting violence on social media following a massacre perpetrated by Hamas on October 7, 2023.
In 2016, legislation was being prepared in Israel, allowing fines of 300,000 shekels for Facebook and other social media like Twitter and YouTube for every post inciting or praising terrorism that is not removed within 48 hours, and could possibly lead to further acts of terrorism.
Countermeasure efforts
In June 2017, Facebook published a blog post, offering insights into how it detects and combats terrorism content. The company claimed that the majority of the terrorism accounts that are found are discovered by Facebook itself, while it reviews reports of terrorism content "urgently", and, in cases of imminent harm, "promptly inform authorities". It also develops new tools to aid in its efforts, including the use of artificial intelligence to match terrorist images and videos, detecting when content is shared across related accounts, and developing technologies to stop repeat offenders. The company stated that it has 150 people dedicated to terrorism countermeasures, and works with governments and industries in an effort to curb terrorist propaganda. Its blog post stated that "We want Facebook to be a hostile place for terrorists."
Employee data leak
In June 2017, The Guardian reported that a software bug had exposed the personal details of 1,000 Facebook workers involved in reviewing and removing terrorism content, by displaying their profiles in the "Activity" logs of Facebook groups related to terrorism efforts. In Facebook's Dublin, Ireland headquarters, six individuals were determined to be "high priority" victims of the error, after the company concluded that their profiles were likely viewed by potential terrorists in groups such as ISIS, Hezbollah and the Kurdistan Workers' Party. The bug itself, discovered in November 2016 and fixed two weeks later, was active for one month, and had also been retroactively exposing censored personal accounts from August 2016. One affected worker had fled Ireland, gone into hiding, and only returned to Ireland after five months due to a lack of money. Suffering from psychological distress, he filed a legal claim against Facebook and CPL Resources, an outsourcing company, seeking compensation. A Facebook spokesperson stated that "Our investigation found that only a small fraction of the names were likely viewed, and we never had evidence of any threat to the people impacted or their families as a result of this matter", and Craig D'Souza, Facebook's head of global investigations, said: "Keep in mind that when the person sees your name on the list, it was in their activity log, which contains a lot of information ... there is a good chance that they associate you with another admin of the group or a hacker". Facebook offered to install a home-alarm monitoring system, provide transport to and from work, and counseling through its employee assistance program. As a result of the data leak, Facebook is reportedly testing the use of alternative, administrative accounts for workers reviewing content, rather than requiring workers to sign in with their personal profiles.
Fake news
Facebook has been criticized for not doing enough to limit the spread of fake news stories on their site, especially after the 2016 United States presidential election, which some have claimed Donald Trump would not have won if Facebook had not helped spread what they claim to have been fake stories that were biased in his favor. At a conference called Techonomy, Mark Zuckerberg stated in regards to Donald Trump, "There's a profound lack of empathy in asserting that the only reason why someone could have voted the way that they did is because they saw some fake news". Zuckerberg affirmed the idea that people do not stray from their own ideals and political leanings. He stated, "I don't know what to do about that" and, "When we started, the north star for us was: We're building a safe community".
Zuckerberg has also been quoted in his own Facebook post, "Of all the content on Facebook, more than 99 percent of what people see is authentic". In addition, The Pew Research Center, stated that "62% of Americans obtain some, or all, of their news on social media-the bulk of it from Facebook". The former editor at Facebook leaked inflammatory information about the websites' algorithm's pointing to certain falsehoods and bias by the news created within Facebook. Although Facebook initially denied claims of issues with fake new stories and their algorithms, they fired the entire trending team involved with a fake news story about Megyn Kelly being a "closeted liberal".
In 2016, Zuckerberg began to take steps to eliminate the prevalence of fake news on Facebook as a result of criticisms of Facebook's influence on the presidential election. Facebook initially partnered with ABC News, the Associated Press, FactCheck.org, Snopes and PolitiFact for its fact-checking initiative; as of 2018, it had over 40 fact-checking partners across the world, including The Weekly Standard. A May 2017 review by The Guardian found that Facebook's fact-checking initiatives of partnering with third-party fact-checkers and publicly flagging fake news were regularly ineffective, and appeared to be having minimal impact in some cases. In 2018, journalists working as fact-checkers for Facebook criticized the partnership, stating that it had produced minimal results and that the company had ignored their concerns.
Incitement of violence in Sri Lanka
In March 2018, the government of Sri Lanka blocked Facebook and other social media services in an effort to quell the violence in the 2018 anti-Muslim riots, with Harsha de Silva, the Deputy Minister for National Policies and Economic Affairs, tweeting: "Hate speech on Facebook is increasing beyond acceptable levels. Government will have to act immediately to save lives." Sri Lankan telecommunications minister Harin Fernando stated that Facebook had been too slow in removing content and banning users who were using its platforms to facilitate violence during the riots. In response, Facebook stated that it had increased the number of Sinhalese speakers it employs to review content.
In April 2019, during the aftermath of the Easter bombings, the Sri Lankan government blocked access to Facebook, Instagram and WhatsApp in an effort to stop the spread of misinformation that could lead to further violence.
Inclusion of Breitbart News as trusted news source
In October 2019, Facebook announced that Breitbart News, an American far-right news and opinion website, would be included as a "trusted source" in its Facebook News feature alongside sources like The New York Times and The Washington Post. The decision sparked controversy due to Breitbart News's status as a platform for the alt-right and its reputation for publishing misinformation. In October 2021, The Wall Street Journal reported that Facebook executives resisted removing Breitbart News from Facebook's News Tab feature to avoid angering Donald Trump and Republican members of Congress, despite criticism from Facebook employees. An August 2019 internal Facebook study had found that Breitbart News was the least trusted news source, and also ranked as low-quality, in the sources it looked at across the U.S. and Great Britain.
Disinformation regarding Persecution of Uyghurs
In February 2021, a Press Gazette investigation found that Facebook had accepted promotional content from Chinese state media outlets such as China Daily and China Global Television Network that spread disinformation denying the persecution of Uyghurs in China.
Incitement of human rights abuses in Myanmar
The chairman of the U.N. Independent International Fact-Finding Mission on Myanmar stated that Facebook played a "determining role" in the Rohingya genocide. Facebook has been accused of enabling the spread of Islamophobic content which targets the Rohingya people. The United Nations Human Rights Council has called the platform "a useful instrument for those seeking to spread hate".
The internet.org initiative was brought to Myanmar in 2015. Myanmar's relatively recent democratic transition did not provide the country with substantial time to form professional and reliable media outlets free from government intervention. Furthermore, approximately 1% of Myanmar's residents had internet access before internet.org. As a result, Facebook was the primary source of information and without verifiable professional media options, Facebook became a breeding ground for hate speech and disinformation. "Rumors circulating among family or friends' networks on Facebook were perceived as indistinguishable from verified news by its users." Frequent anti-Rohingya sentiments included high Muslim birthrates, increasing economic influence, and plans to takeover the country. Myanmar's Facebook community was also nearly completely unmonitored by Facebook, who at the time only had two Burmese-speaking employees.
In response, Facebook removed accounts which were owned by the Myanmar Armed Forces because they had previously used Facebook to incite hatred against the Rohingya people, and they were currently "engaging in coordinated inauthentic behavior." In February 2021, Facebook banned the Myanmar military from its platform and set up rules to ban Tatmadaw-linked businesses.
The Myanmar military was not the only account found to have incited violence. In a review undertaken by Facebook in 2018, Facebook "banned accounts and pages associated with Myanmar military personnel that were indicated by the UN as being directly responsible for the ethnic cleansing in Rakhine. The banned accounts had a widespread reach in the country, as they were followed by nearly 12 million accounts, which is about half of all Myanmar's Facebook users."
On 6 December 2021, approximately a hundred Rohingya refugees launched a $150 billion lawsuit against Facebook, alleging that it did not do enough to prevent the proliferation of anti-Rohingya hate speech because it was interested in prioritizing engagement. On 10 December 2021, sixteen Rohingya youth living in Cox's Bazar refugee camp made a complaint against Facebook to the Irish National Contact Point for the OECD Guidelines for Multinational Enterprises, alleging that Facebook had violated the guidelines, and owed them a remedy. The lead complainants in the case included members of Rohingya civil society group Arakan Rohingya Society for Peace and Human Rights (ARSPH). Mohibullah, who founded ARSPH, and had spearheaded efforts amongst camp-based Rohingya refugees to hold Facebook accountable, had been murdered just over two months before.
On 27 December 2023, hundreds of students from various universities in Aceh, Indonesia, such as: Abulyatama University, Bina Bangsa Getsempena University, and University of Muhammadiyah Aceh, stormed a shelter for Rohingya refugees and forced them out of a convention centre in the city of Banda Aceh, demanding they be deported. The students were seen kicking the belongings of the Rohingya men, women, and children who were seated on the floor and crying in fear. They were also seen burning tyres and chanting various anti-Rohingya slogans. The protest was believed to be caused by Facebook due to anti-Rohingya sentiments that spread through the app.
On 23 January 2025, Rohingya human rights activist and genocide survivor Maung Sawyeddollah filed a whistleblower lawsuit against Meta before the U.S. Securities and Exchange Commission (SEC). The lawsuit accused Meta of having mislead shareholders regarding its role in the Rohingya genocide in violation of U.S. securities law. The lawsuit was filed with the support of Amnesty International and the Open Society Foundations.
Blue tick
Facebook grants blue ticks to verified accounts of public personalities, brands, and celebrities (including politicians and artists). They have no policy in the cases where an individual who has a verified blue tick account is convicted in a serious criminal case. A 2018 case in India occurred where a politician was convicted and sentenced to 10 years in jail in a serious bribery criminal case but his Facebook page still continued to be verified.
Neo-Nazi and white supremacist content
From circa 2018 until March 27, 2019, Facebook's internal policy was to permit "white nationalist" content but not "white supremacist" content, despite advice stating there is no distinction. In practice, it hosted much white supremacist and neo-Nazi content. On March 27, 2019, Facebook backtracked and stated that white nationalism "cannot be meaningfully separated from white supremacy and organized hate groups".
In 2020 the Centre for Countering Digital Hate (CCDH) found Facebook was hosting a white supremacist network with more than 80,000 followers and links to the UK far-right. The CCDH said: "Facebook's leadership endangered public safety by letting neo-Nazis finance their activities through Facebook and Instagram ... Facebook was first told about this problem two years ago and failed to act."
COVID-19 misinformation
In February 2020, the Taiwanese Central News Agency reported that large amounts of misinformation had appeared on Facebook claiming the pandemic in Taiwan was out of control, the Taiwanese government had covered up the total number of cases, and that President Tsai Ing-wen had been infected. The Taiwan fact-checking organization had suggested the misinformation on Facebook shared similarities with mainland China due to its use of simplified Chinese characters and mainland China vocabulary. The organization warned that the purpose of the misinformation is to attack the government. The Epoch Times, an anti-Chinese Communist Party (CCP) newspaper affiliated with Falun Gong, has spread misinformation related to the COVID-19 pandemic in print and via social media including Facebook and YouTube.
In April 2020, rumors circulated on Facebook, alleging that the US Government had "just discovered and arrested" Charles Lieber, chair of the Chemistry and Chemical Biology Department at Harvard University for "manufacturing and selling" the novel coronavirus (COVID-19) to China. According to a report from Reuters, posts spreading the rumor were shared in multiple languages over 79,000 times on Facebook.
In January 2021, the Bureau of Investigative Journalism found that 430 Facebook pages – being followed by 45 million people – were spreading false information about COVID-19 or vaccinations. This was despite a promise by Facebook in 2020 that no user or company should directly profit from false information about immunization against COVID-19. A Facebook spokesman said the company had "removed a small number of the pages shared with us for violating our policies". In August 2021, Facebook said that an article raising concerns about potentially fatal effects of a COVID-19 vaccine was the top-performing link in the United States between January and March 2021, and that another site publishing COVID-19 misinformation was among its top 20 visited pages.
Marketplace illegal Amazon rainforest sales
In February 2021, BBC investigations revealed that Amazon rainforest plots on land reserved for indigenous people were being illegally traded on the Facebook Marketplace with the sellers admitting they do not have the land title. The BBC reported that Facebook were "ready to work with local authorities", but were unwilling to take independent action.
Incitement of ethnic massacres in Ethiopia
In February 2022, Facebook was accused by the Bureau of Investigative Journalism and The Observer of letting activists incite ethnic massacres in the Tigray War by spreading hate and misinformation. Following the report, a lawsuit against Meta was filed in December 2022 in the High Court of Kenya by the son of a Tigrayan academic murdered in November 2021 after receiving racist attacks on the platform.
2025 policy changes
In January 2025, ahead of the second presidency of Donald Trump, Meta Platforms announced a number of policy changes across all divisions—some effective immediately— regarding moderation. Among the changes, Facebook will discontinue internal fact-checking in favor of a "Community Notes" system similar to X, in which contextual addendums may be added to posts with agreement from other users. In addition, Meta relaxed certain moderation practices to focus more on severe and illegal content; these include relaxations of certain "Hateful Content" policies to comply with "mainstream discourse", including allowing the targeting of others by "protected characteristics" in connection to the spread of COVID-19, allowing "allegations of mental illness or abnormality when based on gender or sexual orientation, given political and religious discourse about transgenderism and homosexuality and common non-serious usage of words like 'weird.'", and allowing discussions in support of "gender-based limitations of military, law enforcement, and teaching jobs". The company cited ongoing concerns that its services censor "too much harmless content", and a desire to "[provide] people with information about what they’re seeing – and one that’s less prone to bias". Meta also announced that it would re-locate its Trust & Safety division to Texas and other locations to reduce bias. Mark Zuckerberg stated that the changes were to ensure "more speech and fewer [moderation] mistakes".
The changes have faced criticism—especially from journalists and LGBT rights advocates—for opening LGBT users of Meta services such as Facebook to homophobic and transphobic prejudice, with comparisons drawn to the changes in content policies enacted by Elon Musk after his acquisition of Twitter (X). Human Rights Campaign (HRC) president Kelley Robinson stated that "while we understand the difficulties in enforcing content moderation, we have grave concerns that the changes announced by Meta will put the LGBTQ+ community in danger both online and off." 404 Media reported that the changes have led to major internal dissent among Meta employees. Concurrently, Meta also quietly removed transgender and non-binary flag themes from Messenger, previously added in June 2021 and 2022 respectively for Pride Month.
See also
Censorship by Facebook
Criticism of Facebook
References
Facebook criticisms and controversies
Facebook
Facebook | Facebook content management controversies | [
"Technology"
] | 7,610 | [
"Criticisms of software and websites"
] |
70,090,072 | https://en.wikipedia.org/wiki/Sodium%20polydihydroxyphenylene%20thiosulfonate | Sodium polydihydroxyphenylene thiosulfonate (гипоксен, Hypoxen) is under laboratory studies in Russia as a potential regulator of cell metabolism. It is purported to affect mitochondrial function, though this has not been proven in any high-quality, peer-reviewed publications.
It is registered in Russia as an antihypoxic agent, but has not been subjected to any clinical trials meeting internationally accepted standards, and has no regulatory approval as a prescription drug outside Russia and some former Soviet states. Although called an "oxygen booster" in public media to imply its potential to "increase endurance and reduce fatigue", there is no scientific evidence it has this property, and it is not used in conventional cardiology as a therapy for treating heart disease.
Hypoxen is sold online without a prescription, mainly from Russian websites, and does not appear to be sold in health stores in the United States. Hypoxen is not listed on the prohibited substance list of the World Anti-Doping Agency. In 2017, the United States Anti-Doping Agency applied to have hypoxen banned from athletic competitions, but the ban was not implemented.
It has been identified in tests on athletes in competition, such as Kamila Valieva, a Russian figure-skater competing at the 2022 Winter Olympics, but is not itself banned in international competitions, as of 2022.
It is claimed to be a polymeric mixture containing between 2 and 6 repeat units of 2,4-dihydroxyphenylene with a thiosulphonate group joined at the end.
See also
Meldonium
Trimetazidine
List of Russian drugs
References
Russian drugs | Sodium polydihydroxyphenylene thiosulfonate | [
"Chemistry"
] | 349 | [
"Pharmacology",
"Pharmacology stubs",
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70,092,623 | https://en.wikipedia.org/wiki/Utroba%20Cave | The Utroba Cave, also known as Womb Cave, is a prehistoric cave sanctuary in Kardzhali Province, Bulgaria. Located in the Eastern Rhodupe Mountains near the Ilinista village, the cave resembles a human vulva and dates to the Thracian period. Historians believe that it was once used as a fertility shrine.
It is known in Bulgarian as (, , ) or (, , 'Womb Cave').
History
The cave is located 20 kilometers from the city of Kardzhali near the village of Ilinitsa and it dates to 480 BC. It is also referred to as "The Cave Womb" or "Womb Cave" because the entrance is the shape of a vulva. The inside of the cave resembles a uterus. Locally it is also called "The Blaring Rock". Researchers believe that the entrance to the cave was a slit, which was then widened by humans. The entrance to the cave is tall and wide and inside the cave there is a -tall altar which has been carved.
Archaeologist Nikolay Ovcharov believes that the cave and altar were used by the Thracians. There are several Thracian sanctuaries found in Bulgaria. Ovcharov believes that it was used as a fertility shrine for the Thracians. The "cult" places of the Thracians are usually located at the top of mountains and they have running water. There is also constantly flowing water at the Utroba Cave, which flows from the cave to the foothills.
There is an opening in the ceiling which allows the light into the cave. The light creates a phallus shape every day at noon, but it only reaches the altar on one day of the year. In the middle of the day at a certain time of year the light which is in the shape of a phallus penetrates deep into the cave all the way to the altar. In February or March the light takes the shape of a phallus and enters a hole at the altar: the light then flickers for 1-2 minutes. The penetrating and flickering light is thought to symbolize fertilization.
Even today, there are childless couples who go to the cave hoping it will help them conceive a child.
See also
Thracian religion
References
External links
Video of the Cave-Womb
Tourist attractions in Kardzhali Province
Landforms of Kardzhali Province
Prehistoric sites in Bulgaria
Caves of Bulgaria
Limestone caves
Human sexuality | Utroba Cave | [
"Biology"
] | 502 | [
"Human sexuality",
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"Human behavior",
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70,094,443 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20Z%20Fold%204 | The Samsung Galaxy Z Fold 4 (stylized as Samsung Galaxy Z Fold4, sold as Samsung Galaxy Fold 4 in certain territories) is a foldable smartphone that is part of the Samsung Galaxy Z series. It was announced at the August 2022 edition of Galaxy Unpacked alongside the Galaxy Z Flip 4. It was released on August 25, 2022. It is the successor to the Galaxy Z Fold 3.
Specifications
Design
The Z Fold 4's outer display and back panel use Gorilla Glass Victus+, whilst the foldable inner display is made of Samsung's proprietary "Ultra-Thin Glass" with two protective PET plastic layers covering it, the top of which is a replaceable screen protector.
The Z Fold 4 has an IPX8 ingress protection rating for water resistance, with dust resistance not being rated. The outer frame is constructed from aluminum, marketed as 'Armor Frame' by Samsung.
The Samsung Galaxy Z Fold 4 is available in four colors: Phantom Black, Beige, Graygreen and Burgundy.
Hardware
The Galaxy Z Fold 4 has two screens: its 6.2-inch external cover display and its foldable 7.6-inch inner display featuring support for the S Pen Pro and the S Pen Fold Edition, with both running at 120 Hz and including support for variable refresh rate to help maximize power efficiency.
Compared to the prior generation Z Fold 3, the inner display now has a slightly more square aspect ratio (~6:5 vs ~5:4) due to the external cover display being made moderately wider by about +3 mm; along with both it and the actual phone itself being made ever so slightly shorter. Both of these changes end up combining for a notably wider and thus closer to "traditional phone shaped" ~23.1:9 aspect ratio on the external cover display when it's folded as compared to the Fold 3's notably narrower ~24.5:9.
The device has 12 GB of RAM, and either 256 GB, 512 GB or 1 TB of UFS 3.1 flash storage, with no support for expanding the device's storage capacity via micro-SD cards.
The Z Fold 4 is powered by the Qualcomm Snapdragon 8+ Gen 1.
The device's included battery is a 4400 mAh dual-cell unit that fast charges via USB-C up to 25 W, or via wireless charging up to 15 W.
The Z Fold 4 features three rear cameras, including a 50 MP wide-angle camera, a 12 MP ultra-wide camera, and a 10 MP telephoto camera. The wide camera shares its sensor with the S22 and S22+, replacing the previous 12 MP sensor, and the telephoto camera has been upgraded from 2x to 3x optical zoom. It has two front-facing cameras, with a 10 MP camera on the cover display and a 4 MP under-display camera on the right half of the inner display which now has a less visibly apparent display covering with almost double the pixel density of the previous model.
Software
The Samsung Galaxy Z Fold 4 ships with Android 12L based One UI 4.1.
Gallery
References
External links
Samsung Galaxy
Foldable smartphones
Mobile phones introduced in 2022
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Mobile phones with 8K video recording
Flagship smartphones
Samsung smartphones
Discontinued flagship smartphones
Discontinued Samsung Galaxy smartphones | Samsung Galaxy Z Fold 4 | [
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] | 690 | [
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65,732,625 | https://en.wikipedia.org/wiki/Owl%20Scientific%20Computing | Owl Scientific Computing is a software system for scientific and engineering computing developed in the Department of Computer Science and Technology, University of Cambridge.
The System Research Group (SRG) in the department recognises Owl as one of the representative systems developed in SRG in the 2010s.
The source code is licensed under the MIT License and can be accessed from the GitHub repository.
The library is mostly designed and developed in the functional programming language OCaml. As a unique functional programming language, OCaml offers runtime efficiency, flexible module system, static type checking, intelligent garbage collector, and powerful type inference. Owl inherits these features directly from OCaml. With Owl, users can write succinct type-safe numerical applications in a concise functional language without sacrificing performance. It speeds up the development life-cycle, and reduces the cost from prototype to production use. The system serves as the de facto tool for computation intensive tasks in OCaml.
History
Owl was developed when Dr. Liang Wang was working as a Post-Doc in the OCaml Labs.
Owl originated from a research project which studied the design of synchronous parallel machines for large-scale distributed computing in July 2016.
Back then the libraries for numerical computing in OCaml ecosystem were very limited and the tooling was fragmented at that time. In order to test various analytical applications, many numerical functions had to be implemented, from very low level algebra and random number generators to the high level stuff like algorithmic differentiation and deep neural networks. These code snippets started accumulating. These functions were later taken out and wrapped into a standalone library named Owl.
Owl's architecture undertook at least a dozen of iterations in the beginning, and some of the architectural changes are quite drastic. After one-year intensive development, Owl was capable of doing many complicated numerical tasks (e.g. image classification). Dr. Liang Wang held a tutorial at the CUFP 2017 to demonstrate data science in OCaml.
In 2018, Prof. Richard Mortier gave a talk about Owl in the Alan Turing Institute.
To further promote OCaml and functional programming in data science, Owl provides abundant learning materials in the form of a details manual.
Design and features
Owl has implemented many advanced numerical functions atop of its implementation of n-dimensional arrays. Compared to other numerical libraries, Owl is unique in many perspectives, e.g. algorithmic differentiation and distributed computing have been included as integral components in the core system to maximise developers' productivity. The figure below gives a bird view of Owl's system architecture. The subsystem on the left part is Owl's Numerical system. The modules contained in this subsystem fall into three categories.
The first is core modules contains basic data structures, i.e., N-dimensional array (Ndarray) in both dense and sparse forms. The Ndarray module supports various number types: float32, float64, complex32, complex64, int16, int32, etc.
Also, the core module provide foreign function interfaces to other low level numerical libraries, such as CBLAS and LAPACK. These libraries are fully interfaced to the Linear Algebra module.
The second category is the classic analytics modules. This part contains basic mathematical and statistical functions, linear algebra, regression, optimisation, plotting, etc.
Advanced math and statistics functions such as statistical hypothesis testing and Markov chain Monte Carlo are also included.
As a core functionality, Owl provides the algorithmic differentiation (or automatic differentiation) and dynamic computation graph modules.
The highest level in the Owl architecture includes modules more advanced numerical applications such as neural network, natural language processing, data processing etc.
The Zoo system is used for efficient scripting and code sharing.
The modules in the second category, especially the algorithmic differentiation, make the code at this level quite concise.
The subsystem on the right is called Actor Subsystem which extends Owl's capability to parallel and distributed computing. The core idea is to transform a user application from sequential execution mode into parallel mode (using various computation engines) with minimal efforts. The method is to compose two subsystems together with functors to generate the parallel version of the module defined in the numerical subsystem.
Besides what have been mentioned in this figure, there are several other features in Owl. For example, the JavaScript and unikernel backends, integration with other frameworks such as TensorFlow and PyTorch, utilising GPU and other accelerator frameworks via symbolic graph, etc.
Research
The Owl project is research oriented, and supports research of numerical computing in multiple related topics. Some of its research topics are listed below.
Synchronous parallel distributed machine learning design. Owl is the first to propose using sampling to synchronise nodes in iterative algorithms. The work published on arxiv comes with solid mathematical proof. This idea proves to be advanced and was later proposed in top Machine Learning conferences.
One of the factors that contribute to the small code base of Owl is that it builds advanced analytical functions around the algorithmic differentiation. This idea was also proves to be popular and develops into the paradigm of Differentiable programming. It is now being used in popular numerical packages such as JuliaDiff.
Using the computation graph offers another dimension optimization to the computation in Owl. Besides, the computation graph also bridges Owl application and hardware accelerators such as GPU and TPU. Later, the computation graph becomes a de facto intermediate representation. Standards such as the Open Neural Network Exchange and Neural Network Exchange Format are now widely supported by various deep learning frameworks such as TensorFlow and PyTorch.
The idea of service-level composition and serving was investigated in the Zoo subsystem of Owl. The prototype demonstrates the streamlining various stages in the code development including composition, test, distribution, validation, and deployment. It is very similar to the later MLOps concepts. Recently this topic attracts attention in top system conferences such as OSDI.
As result of research following part of these directions, Owl produces several publications. In 2018, a paper titled Data Analytics Service Composition and Deployment on Edge Devices is accepted at the ACM SIGCOMM 2018 Workshop on Big Data Analytics and Machine Learning for Data Communication Networks.
Two talks are also accepted at the OCaml Workshop of the International Conference on Functional Programming 2019, on the topics of numerical ordinary differential equation solving,
and executing Owl computation on GPUs.
An internship in the OCaml Labs investigates the topic of image segmentation and related memory optimisation in Owl.
In 2022, the book <<OCaml Scientific Computing>> was published by Springer.
In 2023, the book <<Architecture of Advanced Numerical Analysis Systems: Designing a Scientific Computing System using OCaml>> was published by Apress.
See also
Array programming
List of numerical-analysis software
References
Free mathematics software
Numerical analysis software for Linux
Numerical programming languages
Array programming languages
Free science software
Numerical analysis software for macOS
Software using the MIT license | Owl Scientific Computing | [
"Mathematics"
] | 1,440 | [
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65,732,749 | https://en.wikipedia.org/wiki/H%C3%B6here%20Graphische%20Bundes-Lehr-%20und%20Versuchsanstalt | The Höhere Graphische Bundes-Lehr- und Versuchsanstalt (HGBLuVA) ("Higher Federal Institution for Graphic Education and Research"), now commonly known as "die Graphische", founded in 1888 in Vienna, is a vocational college for professions in visual communication and media technology in Austria.
History
Opening
Originally set up as a photographic research institute by the President of the Photographic Society, the graphic teaching and research institute (GLV) was created through the incorporation of the photographic school (a department for photographic reproduction processes connected to the Salzburg State Building School) and the Hörwarter general drawing school in Vienna. Since its foundation, it has made an important contribution to the establishment and development of the graphic professions.
According to a resolution of March 14, 1887, the City Council of Vienna made three floors of the municipal building in Vienna VII, Westbahnstraße 25, available to the former Schottenfelder Realschule for the establishment of a teaching and research institute for photography and reproduction processes. The k. k. Lehr- und Versuchsanstalt für Photographie und Reproductionsverfahren, founded and directed (1888–1923) by Josef Maria Eder, previously of the Technologische Gewerbemuseum (Museum of Applied Technology), for which he established a Section for Photography and Reproduction Techniques, and the Vienna State Trade School where, recently qualified as a university lecturer, he began teaching chemistry and physics in 1881.
It opened on March 1, 1888 with 108 students. In the next school year the number of students rose to 174. In 1890, Eder placed a Wothly solar camera (an early means of enlarging negatives) on the roof. In the context of the history of vocational schools and the applied arts, pioneering educational reforms in Austria from the 1870s created institutions like it outside the format of the classical university, it being a special variation on the “state trade school” (“Staats-Gewerbeschule”). Eder based his institution on earlier foreign models such as the Conservatoire des arts et métiers in Paris (founded 1794), that housed a museum of history and technology and hosted with evening lectures and demonstrations, with lectures in photography commencing in 1891.
From 1897 onwards the name Graphische Lehr- und Versuchsanstalt came into being . In 1906, Emperor Franz Joseph granted the school the designation “Imperial and Royal” in the title, and the Republic of Austria confirmed this distinction when the school's Federal Chancellery approved the use of the national coat of arms.
The beginnings
The GLV was instituted on August 27, 1887 "by the highest resolution to approve the activation of this teaching and research institute in Vienna on March 1, 1888". The aim of the institute was the “training of specialist photographers, retouchers, collotype printers, photolithographers, etc., the instruction of artists, scholars and technicians who want to learn photography as an auxiliary science, furthermore the testing of equipment, chemicals and the implementation of independent scientific investigations in the areas of Photochemistry and Related Subjects”.
The school consisted of two departments; the Institute for Photography and Reproduction Processes and the Research Institute, and in 1891 the Board of Book Printers and Type Founders pointed out the urgent need to add a department for book printers to the school. In 1897 an additional section for the book and illustration trade was opened, the school called "KK Graphische Lehr- und Versuchsanstalt" was then divided into four sections:
Section I: Institute for Photography and Reproduction (corresponds to the former Institute for Photography and Reproduction Processes)
Section II: College for the book and illustration trade
Section III: Research institute for photochemistry and graphic printing processes (corresponds to the original research institute)
Section IV: Collections: graphic collection, library and equipment collection
The first original lithographs by famous artists such as Luigi Kasimir and Tina Blau are thanks to the special course for lithography and lithography introduced in 1905 and 'algraphy' - a planographic printing process from an aluminum plate instead of the stone used in lithography - was first taught in Austria in 1896 at the GLV. The specialty course for lithography and lithography existed until 1913/14, after which a specialist course for xylography (wood engraving and woodcuts) was offered.
In 1908 the graphic arts department was set up on the top floor of the neighbouring house at Westbahnstraße 27 connected by a spiral staircase still in existence in the courtyard at the current location on Leyserstraße.
Women in the graphic teaching and research institute
From 1908 women were also officially admitted. For the period from 1888 to 1918/19, a total of 718 female students at the Graphische are recorded in the largely preserved class lists. Due to changes and new requirements in the job description, the proportion of women continued to grow, so that in some classes it exceeded two thirds.
The Graphics Department
In 1916, the school statute was changed: all-day lessons with photography internship in the 1st and 2nd years as well as training for disabled people were introduced and a drawing school was added.
After the First World War, the school was renamed several times:
In 1919 the name was "Deutsch-Österreichische Graphische Lehr- und Versuchsanstalt"; changed in 1920 to "Staatliche Graphische Lehr- und Versuchsanstalt" and in 1923 to "Graphic Education and Research Institute".
The school in the time of National Socialism
The "annexation of Austria by Germany" resulted in organisational restructuring: semesters were introduced and the GLV was made a subordinate level of a university of the graphic arts administered in Leipzig.
In 1939 the school became a state graphic teaching and research institute . Up to this point, two thirds of all Austrian postage stamps had been designed and engraved in the Graphische.
Post-war period
In 1945 the period of study at the technical school was extended to four years. In 1948, “manual graphics” became “commercial graphics” followed by an honours year. In 1959, a department A was developed: a three-class specialist department for photography with a master class, and a department B: a specialist department for commercial graphics with four classes and an honours year.
Through further school reforms, the university entrance qualification was acquired with the completion of the now five-year course and honours qualification. In 1967, due to a lack of space, the Westbahnstrasse was moved to the new Carl Appel building in Leyserstrasse.
The new building, 1963
On May 22, 1963, the foundation stone of the new campus was laid in the 14th district in the Breitenseer Strasse, Leyserstrasse and Spallartgasse area (Kommandogebäude Theodor Körner). In 1967 the move to the new building began and in 1968 the official opening coincided with the 80th anniversary of the school.
In 1963/64 the first year of the five-year high school for reprography and printing technology began. There was also a four-year technical school.
With the advent of personal computers and their use in the graphics industry, change comes first in typesetting and later in image processing, and in 1984 the advent of desktop publishing brought a revolution that permanently challenged the distinction between photographer, typesetter, layout artist and printer.
In 1988, the Graphische celebrated its 100th anniversary. The rapid development of technology shaped school events in the 1980s, as did the rapid advance of offset printing - albeit at the expense of Letterpress printing. In reproduction technology, scanner technology for the production of colour separations displaced reprography.
Renovation, 2006
Due to renovation work on the building in Leyserstraße, the management and the photography, multimedia and graphics departments moved to an alternative location in Vienna's first district at Schellinggasse 13. After the work was completed, the school was relocated in February 2008.
Notable teachers and students
Maria Austria
Emma Bormann
Hans von Borsody
Josef Maria Eder
Tatjana Gamerith
Heidi Harsieber
Ernst Haas
Gottfried Helnwein
Anna Koppitz
Rudolf Koppitz
Felicitas Kuhn
Hans Larwin
Ludwig Michalek
Josef Mikl
Hermann Nitsch
Erwin Puchinger
Willy Puchner
Stefan Sagmeister
Rudolf Schwarzkogler
Wolf Suschitzky
Anton Velim
References
Further reading
Höhere Graphische Bundes-Lehr- und Versuchsanstalt. (2007). 100 Jahre Graphik-Design-Ausbildung an der Graphischen, Vienna : Graphische (German)
External links
Homepage der Graphischen Bundes-Lehr- und Versuchsanstalt
typographische gesellschaft austria
Penzing (Vienna)
Graphic design
Digital media
Schools in Vienna
Educational institutions established in 1888
1888 establishments in Austria
Media studies
Vocational education in Austria
Art schools in Austria
Photography in Austria | Höhere Graphische Bundes-Lehr- und Versuchsanstalt | [
"Technology"
] | 1,843 | [
"Multimedia",
"Digital media"
] |
65,733,135 | https://en.wikipedia.org/wiki/Krzysztof%20Stanek | Krzysztof Stanek (born 1968) is a Polish observational astrophysicist and Professor and University Distinguished Scholar at Ohio State University. He was named a University Distinguished Scholar in 2018. His research focus is on the explosive deaths of massive stars.
In 2022, Stanek was awarded a Guggenheim Fellowship. He won the Beatrice M. Tinsley Prize along with Christopher Kochanek in 2020 for their work on the All-Sky Automated Survey for Supernovae (ASAS-SN) project. He is a Fellow of the American Association for the Advancement of Science. He has also been the recipient of a Harvard-Smithsonian CfA Postdoctoral Fellowship, the Polish Astronomical Society Young Astronomer Award and a Hubble Postdoctoral Fellowship.
Selected articles
Books
References
Ohio State University faculty
American people of Polish descent
Fellows of the American Association for the Advancement of Science
Living people
1968 births | Krzysztof Stanek | [
"Astronomy"
] | 177 | [
"Astronomers",
"Astronomer stubs",
"Astronomy stubs"
] |
65,734,563 | https://en.wikipedia.org/wiki/PhTx-1 | PhTx-1 is a toxic fraction isolated from the venom of the Brazilian wandering spider Phoneutria nigriventer.
Composition and Target
PhTx-1 has as its main toxin PnTx-1, with a molecular mass of 8,594.6 Da, composed of 77 aminoacid residues, 14 of which are cysteines. PnTx-1, also known as Tx1, exerts an inhibitory effect on neuronal sodium channels (Nav1.2). This component is considered highly pathogenic for primates.
References
Toxicology
Ctenidae
Peptides
Sodium channel blockers | PhTx-1 | [
"Chemistry",
"Environmental_science"
] | 133 | [
"Biomolecules by chemical classification",
"Toxicology",
"Peptides",
"Molecular biology"
] |
65,735,565 | https://en.wikipedia.org/wiki/Cyclodipeptide%20synthases | Cyclodipeptide synthases (CDPSs) are a newly defined family of peptide-bond forming enzymes that are responsible for the ribosome-independent biosynthesis of various cyclodipeptides, which are the precursors of many natural products with important biological activities. As a substrate for this synthesis, CDPSs use two amino acids activated as aminoacyl-tRNAs (aa-tRNAs), therefore diverting them from the ribosomal machinery. The first member of this family was identified in 2002 during the characterization of the albonoursin biosynthetic pathway in Streptomyces noursei. CDPSs are present in bacteria, fungi, and animal cells.
History and research
From 2002, when the first description of a CDPSs was done, until now, the number of reported CDPSs in databases has experienced a significant growth (800 in June 2017). It is probable that these cyclopeptides are implicated in numerous biosynthetic pathways. However, their products’ diversity has not been very explored. The activity of 32 new CPDS has been described. This fact raises the number of experimentally characterized CDPS up to 100 (approximately). Moreover, this research has identified several consensus sequences associated to the formation of a specific cyclodipeptide, enhancing the predictive model of specificity of CDPS. This improved prediction method facilitates the deciphering of independent ways of CDPS.
Structure
CDPSs don’t have a specific structure, given each one has its own specific function, but they still have common architectures, such as a Rossmann-fold domain. CDPSs are monomers that have been found to display a strong structural similarity to the catalytic domains of class Ic aminoacyl tRNA synthetases: both these families, CDPSs and class Ic aaRSs, have a Rossmann-fold domain and their structures can be superimposed showing many structural analogies.
CDPSs characteristically feature a deep surface-accessible pocket bordered by the catalytic residues, which is where the catalysis of amide bond formation takes place. This structure is positioned similarly to the aminoacyl binding pocket in aaRSs, which leads to thinking that CDPSs evolved from class Ic aaRSs.
CDPSs and aaRSs present substantial differences though, such as the absence of ATP-binding motifs in CDPSs, given that these use, unlike aaRSs, amino acids that have already been activated.
Catabolic reaction: How do CDPSs synthesize cyclodipeptides?
It was firstly thought that nonribosomal peptide synthetases (NRPSs) were the responsible ones of CDPs construction, either through specific biosynthetic pathways or with the premature liberation of dipeptidyl intermediates meanwhile the elongation process was done. On account of AlbC discovery, an enzyme with the ability to specifically create CDP using loaded ARNt as substrates, it was disclosed that there was a second route for the cyclodipeptide production.
CDPSs' catalytic cycle begins with the binding of the first aa-tRNA, with its aminoacyl transferred onto a conserved serine residue to form an aminoacyl-enzyme intermediate. The second aa-tRNA interacts with this intermediate so that its aminoacyl is transferred to the aminoacyl-enzyme to form a dipeptidyl-enzyme intermediate. Finally, the dipeptidyl goes through an intramolecular cyclization leading to the final cyclodipeptide.
Classification
CDPSs can be divided into two distinct subfamilies named NYH and XYP, distinguished depending on the conserved residues within their respective active sites, which let experts predict their aminoacyl-tRNA substrates. Both subfamilies mainly differ in the first half of their Rossmann fold, this two structures correspond to two different structural solutions to facilitate the reactivity of the catalytic serine residue. Some NYH’s crystal structures have been identified. These CDPSs’ structure contain a Rossmann fold domain.
NYH form a larger group than XYP, therefore there is more information about them than about the XYP subfamily.
Biosynthesis
CDPS-encoding genes are found in genomic locations with genes encoding additional biosynthetic enzymes (CDPS DmtB1 is an example, encoded by the gene of dmt1 locus). These additional biosynthetic enzymes are for example: oxidoreductases, prenyltransferases, methyltransferases, or cyclases and some proteins as cytochrome P450s.
Applications
Recently bioinformatics are designing a way to predict CDPSs products to understand better how their catalytic process works. Moreover, research has brought to light a lot of chemical information about CDPSs pathways. Different projects can also create chemical diversity.
The importance of the cyclodipeptides production has attracted immense attention because of their properties, not only as antifungal or antibacterial but also as a biological target. That is why an important part of the pharmaceutical products contain CDPs.
See also
Cyclic peptide
Aminoacyl tRNA synthetase
Notes
In elongation reference, go for "Part of transcription of DNA into mRNA".
References
Enzymes
Chemical bonding | Cyclodipeptide synthases | [
"Physics",
"Chemistry",
"Materials_science"
] | 1,091 | [
"Chemical bonding",
"Condensed matter physics",
"nan"
] |
65,736,999 | https://en.wikipedia.org/wiki/List%20of%20sulfonamides | This is a list of sulfonamides used in medicine.
Antimicrobials
Short-acting
Sulfacetamide
Sulfadiazine
Sulfadimidine
Sulfafurazole (sulfisoxazole)
Sulfisomidine (sulfaisodimidine)
Sulfaguanidine
Intermediate-acting
Sulfamethoxazole
Sulfamoxole
Sulfanitran
Long-acting
Sulfadimethoxine
Sulfamethoxypyridazine
Sulfametoxydiazine
Ultra long-acting
Sulfadoxine
Sulfametopyrazine
Terephtyl
Sulfonylureas (anti-diabetic agents)
Acetohexamide
Carbutamide
Chlorpropamide
Glibenclamide (glyburide)
Glibornuride
Gliclazide
Glyclopyramide
Glimepiride
Glipizide
Gliquidone
Glisoxepide
Glicaramide
Tolazamide
Tolbutamide
Diuretics
Acetazolamide
Bumetanide
Chlorthalidone
Clopamide
Furosemide
Hydrochlorothiazide
Indapamide
Mefruside
Metolazone
Xipamide
Methazolamide
Anticonvulsants
Ethoxzolamide
Sultiame
Zonisamide
Dermatologicals
Mafenide
Antiretrovirals
Amprenavir (HIV protease inhibitor)
Darunavir (HIV protease inhibitor)
Delavirdine (non-nucleoside reverse transcriptase inhibitor)
Fosamprenavir (HIV protease inhibitor)
Tipranavir (HIV protease inhibitor)
Hepatitis C antivirals
Asunaprevir (NS3/4A protease inhibitor)
Beclabuvir (NS5B RNA polymerase inhibitor)
Dasabuvir (NS5B RNA polymerase inhibitor)
Grazoprevir (NS3/4A protease inhibitor)
Paritaprevir (NS3/4A protease inhibitor)
Simeprevir (NS3/4A protease inhibitor)
Stimulants
Azabon
NSAIDs
Apricoxib (COX-2 inhibitor)
Celecoxib (COX-2 inhibitor)
Parecoxib (COX-2 inhibitor)
Cardiac and Vasoactive Medications
Bosentan (endothelin receptor antagonist)
Dofetilide (class III antiarrhythmic)
Dronedarone (class III antiarrhythmic)
Ibutilide (class III antiarrhythmic)
Sotalol (β blocker)
Tamsulosin (α blocker)
Udenafil (PDE5 inhibitor)
Others
Brinzolamide (carbonic anhydrase inhibitor for glaucoma)
Dorzolamide (anti-glaucoma carbonic anhydrase inhibitor)
Famotidine (histamine H2 receptor antagonist)
Probenecid (uricosuric)
Sulfasalazine (anti-inflammatory agent and a DMARD)
Sumatriptan (antimigraine triptan)
References
External links
List of sulfonamides
Author of The Demon Under the Microscope, a history of the discovery of the sulfa drugs
A History of the Fight Against Tuberculosis in Canada (Chemotherapy)
Presentation speech, Nobel Prize in Physiology and Medicine, 1939
The History of WW II Medicine
"Five Medical Miracles of the Sulfa Drugs". Popular Science, June 1942, pp. 73–78.
A history of antibiotics
Disulfiram-like drugs
Hepatotoxins
Sulfonamides | List of sulfonamides | [
"Chemistry"
] | 757 | [
"Drug-related lists"
] |
65,737,896 | https://en.wikipedia.org/wiki/Advanced%20Therapy%20Medicinal%20Product | Advanced Therapy Medicinal Products, or ATMPs, are advanced therapeutic drugs that are based on cell therapy or gene therapy (sometimes in combination with a medical device - where they are then called a tissue engineered product). The criteria to which a drug must conform to be classified as an ATMP, are defined in Article 17 of Regulation (EC) No 1394/2007 by the European Commission.
References
Gene therapy
Drugs | Advanced Therapy Medicinal Product | [
"Chemistry",
"Engineering",
"Biology"
] | 84 | [
"Pharmacology",
"Products of chemical industry",
"Genetic engineering",
"Medicinal chemistry stubs",
"Chemicals in medicine",
"Gene therapy",
"Pharmacology stubs",
"Drugs"
] |
65,738,118 | https://en.wikipedia.org/wiki/Formularium%20Slovenicum | Formularium Slovenicum is Slovenian addendum to the European Pharmacopoeia. It promotes Slovenian pharmaceutical terminology and the regulations affecting the field of pharmacy in Slovenia. It has been regularly published by the Agency for Medicinal Products and Medical Devices of the Republic of Slovenia.
Slovenia does not have its own pharmacopoeia, i.e. a collection of monographs and other provisions containing legally binding regulations regarding the development, manufacture, and quality assessment of medicinal products and their ingredients as well as other information on medicinal products and their use. Since 1997, European Pharmacopoeia has been in force in the Republic of Slovenia. The alignment of provisions of the national law in the field of medicinal products and regulations at the level of the European Pharmacopoeia brought forward the need for Slovenian addendum to the European Pharmacopoeia. The committee for drafting the national addendum at the Office for Medicinal Products of the Slovenian Ministry of Health issued in June 1998 the first edition of Formularium Slovenicum. Several amendments and updated editions have followed, though the work of the committee preparing Formularium Slovenicum was interrupted between 2013 and 2018.
Formularium Slovenicum supplements European Pharmacopoeia standards and provides translations of titles, complete translations of the main monographs or their individual parts, and translations of general chapters. The chapter National monographs comprises interesting and useful monographs for Slovenian pharmacy practice that the European Pharmacopoeia does not include. It also includes the chapter Standard Terms for Pharrmaceutical Forms, Methods of Administration, and Containers. Formularium Slovenicum has an important role in the drafting, development, and promotion of Slovenian pharmaceutical terms.
Editions
The first edition has been followed by numerous amendments and updated editions:
1st edition – June 1998, six amendments
2nd edition – 2005, five amendments
3rd edition – 2011, two amendments
4th edition – August 2018, one amendment (solely online)
5th edition – August 2020 (solely online)
References
External links
Pharmacy in Slovenia
Pharmacology literature
Pharmaceutical terminology
Drug safety | Formularium Slovenicum | [
"Chemistry"
] | 419 | [
"Pharmacology",
"Drug safety",
"Pharmacology literature"
] |
65,738,271 | https://en.wikipedia.org/wiki/Agency%20for%20Medicinal%20Products%20and%20Medical%20Devices%20of%20the%20Republic%20of%20Slovenia | Agency for Medicinal Products and Medical Devices of the Republic of Slovenia (; acronym: JAZMP) is a regulatory agency of the Republic of Slovenia competent for medicinal products and medical devices. It was created on 1 January 2007 through the merger of the Agency for Medicinal Products and Medical Devices (, ) and the Institute for Pharmacy and Testing of Medicinal Products – Ljubljana (, ), and as the new entity took over all the rights and obligations of both its predecessors. It is an independent regulatory body competent for medicinal products and medical devices in the fields of human medicine and veterinary medicine, its purpose being protection of public health in the fields of medicinal products and medical devices.
See also
Formularium Slovenicum
References
External links
Medical and health organizations based in Slovenia
Organizations established in 2007
Pharmacy in Slovenia
National agencies for drug regulation
Regulation of medical devices | Agency for Medicinal Products and Medical Devices of the Republic of Slovenia | [
"Chemistry"
] | 167 | [
"National agencies for drug regulation",
"Drug safety"
] |
65,738,568 | https://en.wikipedia.org/wiki/Almost%20open%20map | In functional analysis and related areas of mathematics, an almost open map between topological spaces is a map that satisfies a condition similar to, but weaker than, the condition of being an open map.
As described below, for certain broad categories of topological vector spaces, surjective linear operators are necessarily almost open.
Definitions
Given a surjective map a point is called a for and is said to be (or ) if for every open neighborhood of is a neighborhood of in (note that the neighborhood is not required to be an neighborhood).
A surjective map is called an if it is open at every point of its domain, while it is called an if each of its fibers has some point of openness.
Explicitly, a surjective map is said to be if for every there exists some such that is open at
Every almost open surjection is necessarily a (introduced by Alexander Arhangelskii in 1963), which by definition means that for every and every neighborhood of (that is, ), is necessarily a neighborhood of
Almost open linear map
A linear map between two topological vector spaces (TVSs) is called a or an if for any neighborhood of in the closure of in is a neighborhood of the origin.
Importantly, some authors use a different definition of "almost open map" in which they instead require that the linear map satisfy: for any neighborhood of in the closure of in (rather than in ) is a neighborhood of the origin;
this article will not use this definition.
If a linear map is almost open then because is a vector subspace of that contains a neighborhood of the origin in the map is necessarily surjective.
For this reason many authors require surjectivity as part of the definition of "almost open".
If is a bijective linear operator, then is almost open if and only if is almost continuous.
Relationship to open maps
Every surjective open map is an almost open map but in general, the converse is not necessarily true.
If a surjection is an almost open map then it will be an open map if it satisfies the following condition (a condition that does depend in any way on 's topology ):
whenever belong to the same fiber of (that is, ) then for every neighborhood of there exists some neighborhood of such that
If the map is continuous then the above condition is also necessary for the map to be open. That is, if is a continuous surjection then it is an open map if and only if it is almost open and it satisfies the above condition.
Open mapping theorems
Theorem: If is a surjective linear operator from a locally convex space onto a barrelled space then is almost open.
Theorem: If is a surjective linear operator from a TVS onto a Baire space then is almost open.
The two theorems above do require the surjective linear map to satisfy topological conditions.
Theorem: If is a complete pseudometrizable TVS, is a Hausdorff TVS, and is a closed and almost open linear surjection, then is an open map.
Theorem: Suppose is a continuous linear operator from a complete pseudometrizable TVS into a Hausdorff TVS If the image of is non-meager in then is a surjective open map and is a complete metrizable space.
See also
(also known as the Banach–Schauder theorem)
References
Bibliography
Topological vector spaces | Almost open map | [
"Mathematics"
] | 700 | [
"Topological vector spaces",
"Vector spaces",
"Space (mathematics)"
] |
65,738,713 | https://en.wikipedia.org/wiki/Marie%20Andr%C3%A9%20Destarac | Marie André Destarac Eguizabal (born 25 February 1981) is a Guatemalan scientist who specializes in engineering, electronics and robotics. Her goal is to apply her engineering knowledge and expertise in medicine projects. In 2015, Destarac received an MIT award named "Innovators under 35 in Central America" an acknowledgement by the MIT Technology Review magazine. She was the only woman to get the award. It's an active member of the Organization For Women In Science For The Developing World, chapter Guatemala (OWSD GT) executing and planning events to decrease the gender gap, so girls and women can study careers in STEM.
Early life and education
Marie André Destarac is daughter of Rodolfo Destarac and María Eguizabal. She studied electronic engineering in Universidad del Valle de Guatemala. In 2013 she received a master's degree in Robotics and Automation from the Technical University of Madrid with a scholarship she received from the Education, Culture and Sports Minister of Spain. In 2018, she received a Ph.D. in Robotics by the Technical University of Madrid by the Industrial Ph.D. scholarships program with the support of the Ministry of Economy and Competitiveness (MINECO) of Spain.
Career
Since 2005, Destarac works in research projects in Guatemala, Japan and Spain, her field of work is automation, robotics and medical devices development, she's been a professor at her alma mater Universidad del Valle de Guatemala, teaching computer science, engineering and electronics. She was also the coordinator of innovation research projects to support students to get their Bachelor's degree. Destarac worked as Senior robotics engineer at Aura Innovative Robotics, a startup company from Spain, committed to develop medical devices, later Destarac was hired by the Spanish National Research Council as a postdoctoral researcher.
Destarac currently works as a project manager for the ATLAS pediatric exoskeleton at Madrid, Spain, focusing on device optimization and coordinating and supervising rehabilitation sessions with children using the exoskeleton and the impact of using robotics on children with walking impairment diseases. Destarac runs the human walking analysis laboratory at the Robotics and Automation Center at CSIC.
Robotics and health
Destarac has research the creation of exoskeletons to help treat shoulder and elbow injuries as part of her Ph.D. studies. She's focused on creating a 3D simulation that replicates the muscular behavior and shows injured zones, the importance of this simulator lies on allowing doctors to test treatment thru simulation and then apply to patients, Destarac is also working on building adaptive control systems for exoskeleton rehabilitation, these systems intelligently and in real time adapt the response of the exoskeleton to the needs of the patient.
Published papers
Scientific
Manuel Cardona, Marie André Destarac and Cecilia E. García. “Exoskeleton Robots for Rehabilitation: State of the Art and Future Trends”. IEEE 37th Central America and Panama Convention (CONCAPAN XXXVII), Managua, Nicaragua, 2017, pp. 1–6.
Ricardo Espinoza Gomez, Marie André Destarac, Manuel N. Cardona Gutierrez, Jorge Garcia Montaño, María Camila Sierra Herrera, Rafael Acebron Lopez, Lisandro Jose Puglisi and Cecilia Garcia Cena. “ORTE Exoskeleton: Actuation System Dimensioning and Selection”. IEEE 37th Central America and Panama Convention (CONCAPAN XXXVII), Managua, Nicaragua, 2017, pp. 1–6.
Ricardo Espinoza, Marie André Destarac, Jorge García, Rafael Acebrón, Lisandro Puglisi y Cecilia García. “ORTE-Sistema Robotizado para la rehabilitación del miembro superior”. Libro de actas de las Jornadas Nacionales de Robótica 2017. M. Mellado, A. Sánchez y E. Bernabeu (Eds.) Editorial CEA-IFAC, España, 2017, artículo 32. .
Marie André Destarac, Cecilia E. García Cena, Adrián Mérida Martínez, Luis J. Monge Chamorro and Roque Saltarén Pazmiño. “Analysis of the influence of external actuators on the glenohumeral joint movements”. Advances in Automation and Robotics Research in Latin America. I. Chang, J. Baca, H. A. Moreno, I. G. Carrera and M. Cardona (Eds.) Springer International Publishing, 2017, pp. 71–82. .
Jorge García Montaño, Cecilia E. García Cena, Luis J. Monge Chamorro, Marie André Destarac and Roque Saltarén Pazmiño. “Mechanical Design of a Robotic Exoskeleton for Upper Limb Rehabilitation”. Advances in Automation and Robotics Research in Latin America. I. Chang, J. Baca, H. A. Moreno, I. G. Carrera and M. Cardona (Eds.) Springer International Publishing, 2017, pp. 297–308. .
Marie André Destarac, Cecilia E. García Cena and Roque Saltarén Pazmiño. “Simulation of the Length Change in Muscles during the Arm Rotation for the Upper Brachial Plexus Injury”. Converging Clinical and Engineering Research on Neurorehabilitation II. J. Ibáñez, J. Gonzalez-Vargas, J.M. Azorín, M. Akai and J. L. Pons (Eds.) Springer International Publishing, 2016, vol. 15, pp. 1263–1268. .
Luis J. Monge, Cecilia E. García Cena, Marie André Destarac and Roque Saltarén Pazmiño. “Simulation of Rehabilitation Therapies for Brachial Plexus Injury under the Influence of External Actuators”. Converging Clinical and Engineering Research on Neurorehabilitation II. J. Ibáñez, J. Gonzalez-Vargas, J.M. Azorín, M. Akai and J. L. Pons (Eds.) Springer International Publishing, 2016, vol. 15, pp. 1043–1047. .
Marie André Destarac, Cecilia E. García Cena, Roque Saltarén Pazmiño and Rafael Aracil. Kinematic and Kinetic simulation of Upper Brachial Plexus Injury in the Arm Rotation. Open Conference on Future Trends in Robotics. R. Fernández and H. Montes (Eds.) Consejo Superior de Investigaciones Científicas, mayo 2016, pp. 11–18. .
Luis J. Monge, Marie André Destarac, Cecilia E. García Cena and Santiago Hernández. Modelling and Simulation of servomotors for a Rehabilitation Exoskeleton. Open Conference on Future Trends in Robotics. R. Fernández and H. Montes (Eds.) Consejo Superior de Investigaciones Científicas, mayo 2016, pp. 29–36. .
Marie André Destarac, Cecilia E. García Cena, Roque Saltarén Pazmiño, Mónica J. Reyes Urbina, Javier López López and Ricardo Espinoza Gómez. Modeling and Simulation of Upper Brachial Plexus Injury. IEEE Systems Journal (Q1). .
Cecilia E. García Cena, Roque Saltarén Pazmiño, Marie André Destarac, Edgar Loranca Vega, Ricardo Espinoza Gómez and Rafael Aracil Santonja. Skeletal Modeling, Analysis and Simulation of Upper Limb of Human Shoulder under Brachial Plexus Injury. Advances in Intelligent Systems and Computing ROBOT 2013, Advances in Robotics. M.A. Armada et al. (Eds.). New York Springer-Verlag, 2013, vol.1, pp. 195–207.
Donald Wise, Otto Benavides and Marie André Destarac. Using video conferencing for international teaching. IEEE 63rd Annual Conference International Council for Educational Media (ICEM), pp. 1–13, Oct. 2013.
Donald Wise, Otto Benavides and Marie André Destarac. A Case Study linking the US to Central America. TechTrends: Linking Research & Practice to Improve Learning, vol. 57, no.1, pp. 26–30. Springer US, Boston, Ene. 2013.
Johanna Viau Colindres. Corey Rountree, Marie Andre Destarac, Yiwen Cui, Manuel Perez Valdez, Mario Herrera Castellanos, Yvette Mirabal, Garrett Spiegel, Rebecca Richards-Kortum and Maria Oden. Prospective Randomized Controlled Study Comparing Low-Cost LED and Conventional Phototherapy for Treatment of Neonatal Hyperbilirubinemia. Journal of Tropical Pediatrics (Q3), vol.58, no.3, pp. 178–183, Jun. 2012.
Gerardo Martínez, Luis Reina, Mario Valdeavellano, Carlos Esquit and Marie Destarac. ANIMA: Non-Conventional Brain Computer Interfaces in Robot Control through Electroencephalography and Electrooculography: Motor Module. Proceedings of the Ninth Latin American and Caribbean Conference for Engineering and Technology (LACCEI 2011), Issue 206, Aug. 2011.
Luis F. Reina, Gerardo Martínez, Mario Valdeavellano, Marie Destarac and Carlos Esquit. “ANIMA: Non-Conventional Brain Computer Interfaces in Robot Control through Electroencephalography and Electrooculography: ARP Module” in Advances in Pattern Recognition MCPR 2010, LNCS 6256. J.A. Carrasco-Ochoa et al. (Eds.). New York: Springer-Verlag Berlin Heidelberg, 2010, pp. 71–79.
C. Tercero, E. Tijerino, S. Ikeda, H. Oura, T. Fukuda, M. Destarac, K. Sekiyama, M. Negoro and I.Takahashi. Feedback Control with Hybrid Pump for Realistic Human Blood Pressure Reconstruction. Proceedings of the 9th International IFAC Symposium on Robot Control, pp. 511–6, Sept. 2009.
C. Tercero, E. Tijerino, S. Ikeda, H. Oura, T. Fukuda, M. Destarac, K. Sekiyama, M. Negoro and I.Takahashi. Bomba híbrida para la simulación de la presión arterial humana. Revista de la Universidad del Valle de Guatemala, No. 19, pp. 9–14, Ago. 2009.
Columnist
Desmitificando la robótica, Guatemala 2014. DiarioDigital
La eternidad del Antiguo Egipto, Guatemala, 2014. DiarioDigital
El robot que tardó un minuto en venderse. Guatemala, 2015. DiarioDigital
Una cita con la robótica. Guatemala 2016. DiarioDigital
Honors and awards
Award “Artífices de cambio: las mujeres en la innovación y la creatividad” scientific branch, Cámara de Comercio Americana, AmCham (April 2018).
Award “Guatemaltecos Ilustres” orator category, Seguros Universales de Guatemala (September 2017).
Award “Innovadores menores de 35-Centroamérica”, MIT Technology Review Spanish Edition (November 2015).
Speaker at TEDx-UVG “Ideas que valen ORO” (October 2015).
Nominee “Guatemalteca Ilustre” scientific branch, Seguros Universales, Guatemala (July 2015).
Award "Oficina Nacional de la Mujer del área metropolitana" medal by Guatemala government. (2021)
References
Academic staff of Universidad del Valle de Guatemala
Guatemalan scientists
Guatemalan women scientists
Human-based computation
1981 births
Living people
Technical University of Madrid alumni | Marie André Destarac | [
"Technology"
] | 2,467 | [
"Information systems",
"Human-based computation"
] |
65,740,015 | https://en.wikipedia.org/wiki/List%20of%20set%20identities%20and%20relations | This article lists mathematical properties and laws of sets, involving the set-theoretic operations of union, intersection, and complementation and the relations of set equality and set inclusion. It also provides systematic procedures for evaluating expressions, and performing calculations, involving these operations and relations.
The binary operations of set union () and intersection () satisfy many identities. Several of these identities or "laws" have well established names.
Notation
Throughout this article, capital letters (such as and ) will denote sets. On the left hand side of an identity, typically,
will be the leftmost set,
will be the middle set, and
will be the rightmost set.
This is to facilitate applying identities to expressions that are complicated or use the same symbols as the identity.
For example, the identity
may be read as:
Elementary set operations
For sets and define:
and
where the is sometimes denoted by and equals:
One set is said to another set if Sets that do not intersect are said to be .
The power set of is the set of all subsets of and will be denoted by
Universe set and complement notation
The notation
may be used if is a subset of some set that is understood (say from context, or because it is clearly stated what the superset is).
It is emphasized that the definition of depends on context. For instance, had been declared as a subset of with the sets and not necessarily related to each other in any way, then would likely mean instead of
If it is needed then unless indicated otherwise, it should be assumed that denotes the universe set, which means that all sets that are used in the formula are subsets of
In particular, the complement of a set will be denoted by where unless indicated otherwise, it should be assumed that denotes the complement of in (the universe)
One subset involved
Assume
Identity:
Definition: is called a left identity element of a binary operator if for all and it is called a right identity element of if for all A left identity element that is also a right identity element if called an identity element.
The empty set is an identity element of binary union and symmetric difference and it is also a right identity element of set subtraction
but is not a left identity element of since
so if and only if
Idempotence and Nilpotence :
Domination/Absorbing element:
Definition: is called a left absorbing element of a binary operator if for all and it is called a right absorbing element of if for all A left absorbing element that is also a right absorbing element if called an absorbing element. Absorbing elements are also sometime called annihilating elements or zero elements.
A universe set is an absorbing element of binary union The empty set is an absorbing element of binary intersection and binary Cartesian product and it is also a left absorbing element of set subtraction
but is not a right absorbing element of set subtraction since
where if and only if
Double complement or involution law:
Two sets involved
In the left hand sides of the following identities, is the eft most set and is the ight most set.
Assume both are subsets of some universe set
Formulas for binary set operations , and
In the left hand sides of the following identities, is the eft most set and is the ight most set. Whenever necessary, both and should be assumed to be subsets of some universe set , so that
De Morgan's laws
De Morgan's laws state that for
Commutativity
Unions, intersection, and symmetric difference are commutative operations:
Set subtraction is not commutative. However, the commutativity of set subtraction can be characterized: from it follows that:
Said differently, if distinct symbols always represented distinct sets, then the true formulas of the form that could be written would be those involving a single symbol; that is, those of the form:
But such formulas are necessarily true for binary operation (because must hold by definition of equality), and so in this sense, set subtraction is as diametrically opposite to being commutative as is possible for a binary operation.
Set subtraction is also neither left alternative nor right alternative; instead, if and only if if and only if
Set subtraction is quasi-commutative and satisfies the Jordan identity.
Other identities involving two sets
Absorption laws:
Other properties
Intervals:
Subsets ⊆ and supersets ⊇
The following statements are equivalent for any
Definition of : if then
and are disjoint (that is, )
(that is, )
The following statements are equivalent for any
There exists some
Set equality
The following statements are equivalent:
If then if and only if
Uniqueness of complements: If then
Empty set
A set is empty if the sentence is true, where the notation is shorthand for
If is any set then the following are equivalent:
is not empty, meaning that the sentence is true (literally, the logical negation of " is empty" holds true).
(In classical mathematics) is inhabited, meaning:
In constructive mathematics, "not empty" and "inhabited" are not equivalent: every inhabited set is not empty but the converse is not always guaranteed; that is, in constructive mathematics, a set that is not empty (where by definition, " is empty" means that the statement is true) might not have an inhabitant (which is an such that ).
for some set
If is any set then the following are equivalent:
is empty (), meaning:
for every set
for every set
for some/every set
Given any the following are equivalent:
Moreover,
Meets, Joins, and lattice properties
Inclusion is a partial order:
Explicitly, this means that inclusion which is a binary operation, has the following three properties:
Reflexivity:
Antisymmetry:
Transitivity:
The following proposition says that for any set the power set of ordered by inclusion, is a bounded lattice, and hence together with the distributive and complement laws above, show that it is a Boolean algebra.
Existence of a least element and a greatest element:
Joins/supremums exist:
The union is the join/supremum of and with respect to because:
and and
if is a set such that and then
The intersection is the join/supremum of and with respect to
Meets/infimums exist:
The intersection is the meet/infimum of and with respect to because:
if and and
if is a set such that and then
The union is the meet/infimum of and with respect to
Other inclusion properties:
If then
If and then
Three sets involved
In the left hand sides of the following identities, is the eft most set, is the iddle set, and is the ight most set.
Precedence rules
There is no universal agreement on the order of precedence of the basic set operators.
Nevertheless, many authors use precedence rules for set operators, although these rules vary with the author.
One common convention is to associate intersection with logical conjunction (and) and associate union with logical disjunction (or) and then transfer the precedence of these logical operators (where has precedence over ) to these set operators, thereby giving precedence over
So for example, would mean since it would be associated with the logical statement and similarly, would mean since it would be associated with
Sometimes, set complement (subtraction) is also associated with logical complement (not) in which case it will have the highest precedence.
More specifically, is rewritten so that for example, would mean since it would be rewritten as the logical statement which is equal to
For another example, because means which is equal to both and (where was rewritten as ), the formula would refer to the set
moreover, since this set is also equal to (other set identities can similarly be deduced from propositional calculus identities in this way).
However, because set subtraction is not associative a formula such as would be ambiguous; for this reason, among others, set subtraction is often not assigned any precedence at all.
Symmetric difference is sometimes associated with exclusive or (xor) (also sometimes denoted by ), in which case if the order of precedence from highest to lowest is then the order of precedence (from highest to lowest) for the set operators would be
There is no universal agreement on the precedence of exclusive disjunction with respect to the other logical connectives, which is why symmetric difference is not often assigned a precedence.
Associativity
Definition: A binary operator is called associative if always holds.
The following set operators are associative:
For set subtraction, instead of associativity, only the following is always guaranteed:
where equality holds if and only if (this condition does not depend on ). Thus
if and only if
where the only difference between the left and right hand side set equalities is that the locations of have been swapped.
Distributivity
Definition: If are binary operators then if
while if
The operator if it both left distributes and right distributes over
In the definitions above, to transform one side to the other, the innermost operator (the operator inside the parentheses) becomes the outermost operator and the outermost operator becomes the innermost operator.
Right distributivity:
Left distributivity:
Distributivity and symmetric difference
Intersection distributes over symmetric difference:
Union does not distribute over symmetric difference because only the following is guaranteed in general:
Symmetric difference does not distribute over itself:
and in general, for any sets (where represents ), might not be a subset, nor a superset, of (and the same is true for ).
Distributivity and set subtraction
Failure of set subtraction to left distribute:
Set subtraction is distributive over itself. However, set subtraction is left distributive over itself because only the following is guaranteed in general:
where equality holds if and only if which happens if and only if
For symmetric difference, the sets and are always disjoint.
So these two sets are equal if and only if they are both equal to
Moreover, if and only if
To investigate the left distributivity of set subtraction over unions or intersections, consider how the sets involved in (both of) De Morgan's laws are all related:
always holds (the equalities on the left and right are De Morgan's laws) but equality is not guaranteed in general (that is, the containment might be strict).
Equality holds if and only if which happens if and only if
This observation about De Morgan's laws shows that is left distributive over or because only the following are guaranteed in general:
where equality holds for one (or equivalently, for both) of the above two inclusion formulas if and only if
The following statements are equivalent:
that is, left distributes over for these three particular sets
that is, left distributes over for these three particular sets
and
Quasi-commutativity:
always holds but in general,
However, if and only if if and only if
Set subtraction complexity: To manage the many identities involving set subtraction, this section is divided based on where the set subtraction operation and parentheses are located on the left hand side of the identity. The great variety and (relative) complexity of formulas involving set subtraction (compared to those without it) is in part due to the fact that unlike and set subtraction is neither associative nor commutative and it also is not left distributive over or even over itself.
Two set subtractions
Set subtraction is associative in general:
since only the following is always guaranteed:
If
with equality if and only if
One set subtraction
Set subtraction on the left, and parentheses on the
Set subtraction on the left, and parentheses on the
where the above two sets that are the subjects of De Morgan's laws always satisfy
Set subtraction on the right, and parentheses on the
Set subtraction on the right, and parentheses on the
Three operations on three sets
Operations of the form :
Operations of the form :
Operations of the form :
Other simplifications
Other properties:
If then
If then
if and only if for any belongs to of the sets
Symmetric difference ∆ of finitely many sets
Given finitely many sets something belongs to their symmetric difference if and only if it belongs to an odd number of these sets. Explicitly, for any if and only if the cardinality is odd. (Recall that symmetric difference is associative so parentheses are not needed for the set ).
Consequently, the symmetric difference of three sets satisfies:
Cartesian products of finitely many sets
Binary distributes over and and and
The binary Cartesian product ⨯ distributes over unions, intersections, set subtraction, and symmetric difference:
But in general, ⨯ does not distribute over itself:
Binary of finite
Binary of finite
Difference of finite
and
Finite of differences
Symmetric difference and finite
In general, need not be a subset nor a superset of
Arbitrary families of sets
Let and be indexed families of sets. Whenever the assumption is needed, then all indexing sets, such as and are assumed to be non-empty.
Definitions
A or (more briefly) a refers to a set whose elements are sets.
An is a function from some set, called its , into some family of sets.
An indexed family of sets will be denoted by where this notation assigns the symbol for the indexing set and for every index assigns the symbol to the value of the function at
The function itself may then be denoted by the symbol which is obtained from the notation by replacing the index with a bullet symbol explicitly, is the function:
which may be summarized by writing
Any given indexed family of sets (which is a function) can be canonically associated with its image/range (which is a family of sets).
Conversely, any given family of sets may be associated with the -indexed family of sets which is technically the identity map
However, this is a bijective correspondence because an indexed family of sets is required to be injective (that is, there may exist distinct indices such as ), which in particular means that it is possible for distinct indexed families of sets (which are functions) to be associated with the same family of sets (by having the same image/range).
Arbitrary unions defined
If then which is somethings called the (despite being called a convention, this equality follows from the definition).
If is a family of sets then denotes the set:
Arbitrary intersections defined
If then
If is a family of sets then denotes the set:
Nullary intersections
If then
where every possible thing in the universe vacuously satisfied the condition: "if then ". Consequently, consists of in the universe.
So if and:
if you are working in a model in which there exists some universe then
otherwise, if you are working in a model in which "the class of all things " is not a set (by far the most common situation) then is because consists of , which makes a proper class and a set.
Assumption: Henceforth, whenever a formula requires some indexing set to be non-empty in order for an arbitrary intersection to be well-defined, then this will automatically be assumed without mention.
A consequence of this is the following assumption/definition:
A of sets or an refers to the intersection of a finite collection of sets.
Some authors adopt the so called , which is the convention that an empty intersection of sets is equal to some canonical set. In particular, if all sets are subsets of some set then some author may declare that the empty intersection of these sets be equal to However, the nullary intersection convention is not as commonly accepted as the nullary union convention and this article will not adopt it (this is due to the fact that unlike the empty union, the value of the empty intersection depends on so if there are multiple sets under consideration, which is commonly the case, then the value of the empty intersection risks becoming ambiguous).
Multiple index sets
Distributing unions and intersections
Binary ⋂ of arbitrary ⋃'s
and
If all are pairwise disjoint and all are also pairwise disjoint, then so are all (that is, if then ).
Importantly, if then in general, (an example of this is given below). The single union on the right hand side be over all pairs The same is usually true for other similar non-trivial set equalities and relations that depend on two (potentially unrelated) indexing sets and (such as or ). Two exceptions are (unions of unions) and (intersections of intersections), but both of these are among the most trivial of set equalities (although even for these equalities there is still something that must be proven).
: Let and let Let and let Then Furthermore,
Binary ⋃ of arbitrary ⋂'s
and
Importantly, if then in general, (an example of this is given above). The single intersection on the right hand side be over all pairs
Arbitrary ⋂'s and arbitrary ⋃'s
Incorrectly distributing by swapping ⋂ and ⋃
Naively swapping and may produce a different set
The following inclusion always holds:
In general, equality need not hold and moreover, the right hand side depends on how for each fixed the sets are labelled; and analogously, the left hand side depends on how for each fixed the sets are labelled. An example demonstrating this is now given.
Example of dependence on labeling and failure of equality: To see why equality need not hold when and are swapped, let and let and Then
If and are swapped while and are unchanged, which gives rise to the sets and then
In particular, the left hand side is no longer which shows that the left hand side depends on how the sets are labelled.
If instead and are swapped while and are unchanged, which gives rise to the sets and then both the left hand side and right hand side are equal to which shows that the right hand side also depends on how the sets are labeled.
Equality in can hold under certain circumstances, such as in , which is the special case where is (that is, with the same indexing sets and ), or such as in , which is the special case where is (that is, with the indexing sets and swapped).
For a correct formula that extends the distributive laws, an approach other than just switching and is needed.
Correct distributive laws
Suppose that for each is a non-empty index set and for each let be any set (for example, to apply this law to use for all and use for all and all ). Let
denote the Cartesian product, which can be interpreted as the set of all functions such that for every Such a function may also be denoted using the tuple notation where for every and conversely, a tuple is just notation for the function with domain whose value at is both notations can be used to denote the elements of
Then
where
Applying the distributive laws
: In the particular case where all are equal (that is, for all which is the case with the family for example), then letting denote this common set, the Cartesian product will be which is the set of all functions of the form The above set equalities and , respectively become:
which when combined with implies:
where
on the left hand side, the indices range over (so the subscripts of range over )
on the right hand side, the indices range over (so the subscripts of range over ).
: To apply the general formula to the case of and use and let for all and let for all
Every map can be bijectively identified with the pair (the inverse sends to the map defined by and this is technically just a change of notation). Recall that was
Expanding and simplifying the left hand side gives
and doing the same to the right hand side gives:
Thus the general identity reduces down to the previously given set equality :
Distributing subtraction over ⋃ and ⋂
The next identities are known as De Morgan's laws.
The following four set equalities can be deduced from the equalities - above.
In general, naively swapping and may produce a different set (see this note for more details).
The equalities
found in and are thus unusual in that they state exactly that swapping and will change the resulting set.
Commutativity and associativity of ⋃ and ⋂
Commutativity:
Unions of unions and intersections of intersections:
and
and if then also:
Cartesian products of arbitrarily many sets
Intersections of
If is a family of sets then
Moreover, a tuple belongs to the set in above if and only if for all and all
In particular, if and are two families indexed by the same set then
So for instance,
and
Intersections of products indexed by different sets
Let and be two families indexed by different sets.
Technically, implies
However, sometimes these products are somehow identified as the same set through some bijection or one of these products is identified as a subset of the other via some injective map, in which case (by abuse of notation) this intersection may be equal to some other (possibly non-empty) set.
For example, if and with all sets equal to then and where , for example, is identified as a subset of through some injection, such as maybe for instance; however, in this particular case the product actually represents the -indexed product where
For another example, take and with and all equal to Then and which can both be identified as the same set via the bijection that sends to Under this identification,
Binary distributes over arbitrary and
The binary Cartesian product ⨯ distributes over arbitrary intersections (when the indexing set is not empty) and over arbitrary unions:
Distributing arbitrary over arbitrary
Suppose that for each is a non-empty index set and for each let be any set (for example, to apply this law to use for all and use for all and all ). Let
denote the Cartesian product, which (as mentioned above) can be interpreted as the set of all functions such that for every .
Then
where
Unions of
For unions, only the following is guaranteed in general:
where is a family of sets.
Example where equality fails: Let let let and let Then More generally, if and only if for each at least one of the sets in the -indexed collections of sets is empty, while if and only if for each at least one of the sets in the -indexed collections of sets is not empty.
However,
Difference of
If and are two families of sets then:
so for instance,
and
Symmetric difference of
Functions and sets
Let be any function.
Let be completely arbitrary sets. Assume
Definitions
Let be any function, where we denote its by and denote its by
Many of the identities below do not actually require that the sets be somehow related to 's domain or codomain (that is, to or ) so when some kind of relationship is necessary then it will be clearly indicated.
Because of this, in this article, if is declared to be "," and it is not indicated that must be somehow related to or (say for instance, that it be a subset or ) then it is meant that is truly arbitrary.
This generality is useful in situations where is a map between two subsets and of some larger sets and and where the set might not be entirely contained in and/or (e.g. if all that is known about is that ); in such a situation it may be useful to know what can and cannot be said about and/or without having to introduce a (potentially unnecessary) intersection such as: and/or
Images and preimages of sets
If is set then the is defined to be the set:
while the is:
where if is a singleton set then the or is
Denote by or the or of which is the set:
Saturated sets
A set is said to be or a if any of the following equivalent conditions are satisfied:
There exists a set such that
Any such set necessarily contains as a subset.
Any set not entirely contained in the domain of cannot be -saturated.
and
The inclusion always holds, where if then this becomes
<li> and if and satisfy then
Whenever a fiber of intersects then contains the entire fiber. In other words, contains every -fiber that intersects it.
Explicitly: whenever is such that then
In both this statement and the next, the set may be replaced with any superset of (such as ) and the resulting statement will still be equivalent to the rest.
The intersection of with a fiber of is equal to the empty set or to the fiber itself.
Explicitly: for every the intersection is equal to the empty set or to (that is, or ).
For a set to be -saturated, it is necessary that
Compositions and restrictions of functions
If and are maps then denotes the map
with domain and codomain
defined by
The denoted by is the map
with defined by sending to that is,
Alternatively, where denotes the inclusion map, which is defined by
(Pre)Images of arbitrary unions ⋃'s and intersections ⋂'s
If is a family of arbitrary sets indexed by then:
So of these four identities, it is that are not always preserved. Preimages preserve all basic set operations. Unions are preserved by both images and preimages.
If all are -saturated then be will be -saturated and equality will hold in the first relation above; explicitly, this means:
If is a family of arbitrary subsets of which means that for all then becomes:
(Pre)Images of binary set operations
Throughout, let and be any sets and let be any function.
Summary
As the table below shows, set equality is guaranteed for of: intersections, set subtractions, and symmetric differences.
Preimages preserve set operations
Preimages of sets are well-behaved with respect to all basic set operations:
In words, preimages distribute over unions, intersections, set subtraction, and symmetric difference.
Images preserve unions
Images of unions are well-behaved:
but images of the other basic set operations are since only the following are guaranteed in general:
In words, images distribute over unions but not necessarily over intersections, set subtraction, or symmetric difference. What these latter three operations have in common is set subtraction: they either set subtraction or else they can naturally as the set subtraction of two sets:
If then where as in the more general case, equality is not guaranteed. If is surjective then which can be rewritten as: if and
Counter-examples: images of operations not distributing
If is constant, and then all four of the set containments
are strict/proper (that is, the sets are not equal) since one side is the empty set while the other is non-empty. Thus equality is not guaranteed for even the simplest of functions.
The example above is now generalized to show that these four set equalities can fail for any constant function whose domain contains at least two (distinct) points.
: Let be any constant function with image and suppose that are non-empty disjoint subsets; that is, and which implies that all of the sets and are not empty and so consequently, their images under are all equal to
The containment is strict:
In words: functions might not distribute over set subtraction
The containment is strict:
The containment is strict:
In words: functions might not distribute over symmetric difference (which can be defined as the set subtraction of two sets: ).
The containment is strict:
In words: functions might not distribute over set intersection (which can be defined as the set subtraction of two sets: ).
What the set operations in these four examples have in common is that they either set subtraction (examples (1) and (2)) or else they can naturally as the set subtraction of two sets (examples (3) and (4)).
Mnemonic: In fact, for each of the above four set formulas for which equality is not guaranteed, the direction of the containment (that is, whether to use ) can always be deduced by imagining the function as being and the two sets ( and ) as being non-empty disjoint subsets of its domain. This is because equality fails for such a function and sets: one side will be always be and the other non-empty − from this fact, the correct choice of can be deduced by answering: "which side is empty?" For example, to decide if the in
should be pretend
that is constant and that and are non-empty disjoint subsets of 's domain; then the hand side would be empty (since ), which indicates that should be (the resulting statement is always guaranteed to be true) because this is the choice that will make
true.
Alternatively, the correct direction of containment can also be deduced by consideration of any constant with and
Furthermore, this mnemonic can also be used to correctly deduce whether or not a set operation always distribute over images or preimages; for example, to determine whether or not always equals or alternatively, whether or not always equals (although was used here, it can replaced by ). The answer to such a question can, as before, be deduced by consideration of this constant function: the answer for the general case (that is, for arbitrary and ) is always the same as the answer for this choice of (constant) function and disjoint non-empty sets.
Conditions guaranteeing that images distribute over set operations
Characterizations of when equality holds for sets:
For any function the following statements are equivalent:
is injective.
This means: for all distinct
(The equals sign can be replaced with ).
(The equals sign can be replaced with ).
(The equals sign can be replaced with ).
(The equals sign can be replaced with ).
Any one of the four statements (b) - (e) but with the words "for all" replaced with any one of the following:
"for all singleton subsets"
In particular, the statement that results from (d) gives a characterization of injectivity that explicitly involves only one point (rather than two): is injective if and only if
"for all disjoint singleton subsets"
For statement (d), this is the same as: "for all singleton subsets" (because the definition of "pairwise disjoint" is satisfies vacuously by any family that consists of exactly 1 set).
"for all disjoint subsets"
In particular, if a map is not known to be injective then barring additional information, there is no guarantee that any of the equalities in statements (b) - (e) hold.
An example above can be used to help prove this characterization. Indeed, comparison of that example with such a proof suggests that the example is representative of the fundamental reason why one of these four equalities in statements (b) - (e) might not hold (that is, representative of "what goes wrong" when a set equality does not hold).
Conditions for f(L⋂R) = f(L)⋂f(R)
Characterizations of equality: The following statements are equivalent:
The left hand side is always equal to (because always holds).
If satisfies then
If but then
Any of the above three conditions (i) - (k) but with the subset symbol replaced with an equals sign
Sufficient conditions for equality: Equality holds if any of the following are true:
is injective.
The restriction is injective.
is -saturated; that is,
is -saturated; that is,
or equivalently,
or equivalently,
or equivalently,
In addition, the following always hold:
Conditions for f(L\R) = f(L)\f(R)
Characterizations of equality: The following statements are equivalent:
Whenever then
The set on the right hand side is always equal to
This is the above condition (f) but with the subset symbol replaced with an equals sign
Necessary conditions for equality (excluding characterizations): If equality holds then the following are necessarily true:
or equivalently
or equivalently,
Sufficient conditions for equality: Equality holds if any of the following are true:
is injective.
The restriction is injective.
or equivalently,
is -saturated; that is,
or equivalently,
Conditions for f(X\R) = f(X)\f(R)
Characterizations of equality: The following statements are equivalent:
is -saturated.
Whenever then
where if then this list can be extended to include:
is -saturated; that is,
Sufficient conditions for equality: Equality holds if any of the following are true:
is injective.
is -saturated; that is,
Conditions for f(L∆R) = f(L)∆f(R)
Characterizations of equality: The following statements are equivalent:
and
and
and
The inclusions and always hold.
If this above set equality holds, then this set will also be equal to both and
and
Necessary conditions for equality (excluding characterizations): If equality holds then the following are necessarily true:
or equivalently
Sufficient conditions for equality: Equality holds if any of the following are true:
is injective.
The restriction is injective.
Exact formulas/equalities for images of set operations
Formulas for f(L\R) =
For any function and any sets and
Formulas for f(X\R) =
Taking in the above formulas gives:
where the set is equal to the image under of the largest -saturated subset of
In general, only always holds and equality is not guaranteed; but replacing "" with its subset "" results in a formula in which equality is guaranteed:
From this it follows that:
If then which can be written more symmetrically as (since ).
Formulas for f(L∆R) =
It follows from and the above formulas for the image of a set subtraction that for any function and any sets and
Formulas for f(L) =
It follows from the above formulas for the image of a set subtraction that for any function and any set
This is more easily seen as being a consequence of the fact that for any if and only if
Formulas for f(L⋂R) =
It follows from the above formulas for the image of a set that for any function and any sets and
where moreover, for any
if and only if if and only if if and only if
The sets and mentioned above could, in particular, be any of the sets or for example.
(Pre)Images of set operations on (pre)images
Let and be arbitrary sets, be any map, and let and
(Pre)Images of operations on images
Since
Since
Using this becomes and
and so
(Pre)Images and Cartesian products Π
Let and for every let
denote the canonical projection onto
Definitions
Given a collection of maps indexed by define the map
which is also denoted by This is the unique map satisfying
Conversely, if given a map then
Explicitly, what this means is that if
is defined for every then the unique map satisfying: for all or said more briefly,
The map should not be confused with the Cartesian product of these maps, which is by definition is the map
with domain rather than
Preimage and images of a Cartesian product
Suppose
If then
If then
where equality will hold if in which case and
For equality to hold, it suffices for there to exist a family of subsets such that in which case:
and for all
(Pre)Image of a single set
Containments ⊆ and intersections ⋂ of images and preimages
Equivalences and implications of images and preimages
Intersection of a set and a (pre)image
The following statements are equivalent:
Thus for any
Sequences and collections of families of sets
Definitions
A or simply a is a set whose elements are sets.
A is a family of subsets of
The of a set is the set of all subsets of :
Notation for sequences of sets
Throughout, will be arbitrary sets and and will denote a net or a sequence of sets where if it is a sequence then this will be indicated by either of the notations
where denotes the natural numbers.
A notation indicates that is a net directed by which (by definition) is a sequence if the set which is called the net's indexing set, is the natural numbers (that is, if ) and is the natural order on
Disjoint and monotone sequences of sets
If for all distinct indices then is called a or simply a .
A sequence or net of set is called or if (resp. or ) if for all indices (resp. ).
A sequence or net of set is called (resp. ) if it is non-decreasing (resp. is non-increasing) and also for all indices
It is called if it is non-decreasing or non-increasing and it is called if it is strictly increasing or strictly decreasing.
A sequences or net is said to denoted by or if is increasing and the union of all is that is, if
It is said to denoted by or if is increasing and the intersection of all is that is, if
Definitions of elementwise operations on families
If are families of sets and if is any set then define:
which are respectively called , , () , , and the / The regular union, intersection, and set difference are all defined as usual and are denoted with their usual notation: and respectively.
These elementwise operations on families of sets play an important role in, among other subjects, the theory of filters and prefilters on sets.
The of a family is the family:
and the is the family:
Definitions of categories of families of sets
The following table lists some well-known categories of families of sets having applications in general topology and measure theory.
A family is called , , or in if and
A family is called if
A family is said to be:
(resp. ) if whenever then (respectively, ).
(resp. ) if whenever are elements of then so is their intersections (resp. so is their union ).
(or ) if whenever then
A family of sets is called a/an:
if and is closed under finite-intersections.
Every non-empty family is contained in a unique smallest (with respect to ) −system that is denoted by and called
and is said to have if and
if is a family of subsets of that is a −system, is upward closed in and is also , which by definition means that it does not contain the empty set as an element.
or if it is a non-empty family of subsets of some set whose upward closure in is a filter on
is a non-empty family of subsets of that contains the empty set, forms a −system, and is also closed under complementation with respect to
is an algebra on that is closed under countable unions (or equivalently, closed under countable intersections).
Sequences of sets often arise in measure theory.
Algebra of sets
A family of subsets of a set is said to be if and for all all three of the sets and are elements of
The article on this topic lists set identities and other relationships these three operations.
Every algebra of sets is also a ring of sets and a π-system.
Algebra generated by a family of sets
Given any family of subsets of there is a unique smallest algebra of sets in containing
It is called and it will be denote it by
This algebra can be constructed as follows:
If then and we are done. Alternatively, if is empty then may be replaced with and continue with the construction.
Let be the family of all sets in together with their complements (taken in ).
Let be the family of all possible finite intersections of sets in
Then the algebra generated by is the set consisting of all possible finite unions of sets in
Elementwise operations on families
Let and be families of sets over
On the left hand sides of the following identities, is the eft most family, is in the iddle, and is the ight most set.
Commutativity:
Associativity:
Identity:
Domination:
Power set
If and are subsets of a vector space and if is a scalar then
Sequences of sets
Suppose that is any set such that for every index
If decreases to then increases to
whereas if instead increases to then decreases to
If are arbitrary sets and if increases (resp. decreases) to then increase (resp. decreases) to
Partitions
Suppose that is any sequence of sets, that is any subset, and for every index let
Then and is a sequence of pairwise disjoint sets.
Suppose that is non-decreasing, let and let for every Then and is a sequence of pairwise disjoint sets.
See also
Notes
Notes
Proofs
Citations
References
.
Courant, Richard, Herbert Robbins, Ian Stewart, What is mathematics?: An Elementary Approach to Ideas and Methods, Oxford University Press US, 1996. . "SUPPLEMENT TO CHAPTER II THE ALGEBRA OF SETS".
Stoll, Robert R.; , Mineola, N.Y.: Dover Publications (1979) . "The Algebra of Sets", pp 16—23.
External links
Operations on Sets at ProvenMath
Articles containing proofs
Basic concepts in infinite set theory
Basic concepts in set theory
Families of sets
Functions and mappings
Isomorphism theorems
Mathematical identities
Mathematics-related lists
Mathematical relations
Operations on sets
Set theory
Theorems in the foundations of mathematics | List of set identities and relations | [
"Mathematics"
] | 8,442 | [
"Predicate logic",
"Mathematical objects",
"Combinatorics",
"Families of sets",
"Basic concepts in set theory",
"Mathematical problems",
"Theorems in the foundations of mathematics",
"Mathematical analysis",
"Set theory",
"Mathematical logic",
"Basic concepts in infinite set theory",
"Algebra"... |
65,740,102 | https://en.wikipedia.org/wiki/Philippine%20Taxonomic%20Initiative | The Philippine Taxonomic Initiative (PTI) is a private Philippine research institute and non-profit organization founded in 2018, located in the Philippines.
Publications
Publications:
M.R.B. Altamirano, M.C.D. Malay, & R.A.A. Bustamante. Check List 18(4): 829-837 (2022). New distribution record of Habenaria gibsonii var. foetida Blatt. & McCann (Orchidaceae, Orchidoideae) from Panay Island, Philippines, with notes on allied taxa, ecology, and conservation
C.J.P. Dela Cruz, S.R. Concepcion, & Y.P. Ang. Taiwaniana 67(2): 223‒228 (2022). Begonia francisabuidii, (section Baryandra, Begoniaceae) a new species endemic to Albay, Luzon Island, Philippines
J.A. Mansibang, & T.L.P. Senarillos. Philippine Journal of Science, 151(1), 497-501 (2022). Naked-faced Spiderhunter (Arachnothera clarae): a Flower Visitor and a Potential Pollinator of the Genus Aeschynanthus
R.A.A. Bustamante, & P.B. Pelser. Blumea 67 (1): 15–19 (2022). A new Philippine species of Ridsdalea (Rubiaceae, Ixoroideae) from karst vegetation in Palawan
L.M. Camangeg, W. Cabanillas, M.N. Tamayo, V.C. Mangussad, Y.P. Ang, & M.A.K. Pranada. Gardens’ Bulletin Singapore, 73, 399-412 (2021). Two endemic new species of Begonia (Begoniaceae) from Palawan, Philippines
L.M. Magtoto, M.N. Tamayo, L. Udasco, Jr., & R.A.A. Bustamante. Phytotaxa, 525(4), 295(300) (2021). Ardisia kalimbahin (Primulaceae, Myrsinoideae), a new species from the Philippines
K.R.F. Mazo, J. Mansibang, L.G. Aribal, & M.N. Tamayo. Webbia. Journal of Plant Taxonomy and Geography 76(2), 203-212 (2021). You ‘Sau’ Me! A new species and a rediscovery in the genus Saurauia (Actinidiaceae) from Zamboanga Peninsula, Mindanao Island, Philippines
R.A.A. Bustamante, C. Claudel, J.C. Altomonte, L. Udasco Jr., & M.N. Tamayo. Nordic Journal of Botany, 39(8) (2021). Amorphophallus minimus (Araceae), a new species from the montane forest of Nueva Ecija, Luzon island, Philippines
K.R.F. Mazo, L.G. Aribal, R.A.A. Bustamante, & Y.P. Ang. Phytotaxa, 516(1), 101–107 (2021). Begonia tinuyopensis (sect. Petermannia, Begoniaceae), a new species from Zamboanga Del Norte, Philippines
M.N. Tamayo, R.A.A. Bustamante, & P. Fritsch. PhytoKeys, 179, 145–154 (2021). Vaccinium exiguum (Ericaceae, Vaccinieae), a new species from the ultramafic summit of Mt. Victoria, Palawan Island, Philippines
P.B. Pelser, F. Brambach, J. Mansibang, H. Schaefer, R. Kiew, & J.F. Barcelona. Blumea 66 pp96–100 (2021). New combinations and names for some Philippine vascular plants
D.P. Buenavista, Y.P. Ang, M.A.K. Pranada, D.S. Salas, E. Mollee & M. McDonald. Phytotaxa 497 (2021). Begonia bangsamoro (Begoniaceae, section Petermannia), a new species from Mindanao island, the Philippines
S.M. Olimpos & J. Mansibang. Phytotaxa 487 (2021). Aeschynanthus rejieae (Gesneriaceae), a new species of lipstick vine from Tawi-Tawi, Philippines
A.J.L. Saavedra, & K.M.E. Pitogo. Philippine Journal of Science (2021). Richness and Distribution of Orchids (Orchidaceae) in the Forests of Mount Busa, Sarangani, Southern Mindanao, Philippines
D. Tandang, T. Reyes Jr., R.A.A. Bustamante, J. Callado, E. Tadiosa, E. Agoo, & S. P. Lyon. Phytotaxa 477 (2020). Corybas boholensis (Orchidaceae): A New Jewel Orchid Species from Bohol Island, Central Visayas, Philippines
P. Quakenbush, P.L. Malabrigo Jr., A.G.A. Umali, A.B. Tobia, L.M. Camangeg, Y. P. Ang, & R.A.A. Bustamante. Systematic Botany (2020). Notes on the Medinilla (Melastomataceae) of Palawan, Philippines, Including Two New Species: M. simplicymosa and M. ultramaficola.
R.A.A. Bustamante, J. Mansibang, W. Hetterschied, & M.N. Tamayo. Nordic Journal of Botany e02982(2020) 2. Amorphophallus caudatus (Thomsonieae, Araceae) a new species from Camarines Norte, Luzon island, the Philippines
R.A.A. Bustamante, M.N. Tamayo, & W. Hetterschied, Webbia 75 (2020) 288. Rediscovery of a lost type: solving the mysterious identity of A. longispathaceus Engl. & Gehrm. (Araceae)
M.G. Rule, Y.P. Ang, R.R. Rubite, R. Docot, R. Bustamante, & A. Robinson, Phytotaxa 470 (2020) 226. Begonia makuruyot (Begoniaceae, section Baryandra), a new species from Surigao del Norte Province, Philippines
R.A.A. Bustamante, D. Tandang, M.A. Pranada, & Y.P. Ang, Phytotaxa 458 (2020) 217. Begonia truncatifolia (Begoniaceae, Sect. Baryandra) A new species from Palawan Island, The Philippines.
M.N. Tamayo, M.A. Pranada, & R.A.A. Bustamante. Phytotaxa 455 (2020) 241. Dendrochilum ignisiflorum (Coelogyneae, Orchidaceae), A new species from Luzon island, Philippines.
Y.P. Ang, D. Tandang, R.R. Rubite, & R.A.A. Bustamante. Phytotaxa 455 (2020) 197. Begonia beijnenii (Batyandra, Begoniaceae), A new species from San Vicente, Palawan, The Philippines
Y.P. Ang, D. Tandang, J.M. Agcaoilli, & R.A.A. Bustamante. Phytotaxa 453 (2020) 245. Begonia cabanillasii (section Baryandra, Begoniaceae) a new species from el nido, Palawan, The Philippines
D. Tandang, R.A.A. Bustamante, U.F. Ferreras, U.F. Hadsall, S. Pim-Lyon, & A.S. Robinson. Phytotaxa 446 (2020) 136. Corybas circinatus (Orchidaceae) A new species from Palawan, The Philippines.
R.V.A. Docot, L.C.P. Santiago, H. Funakoshi, & N.F. Lam. Edinburgh Journal of Botany, 77(3), 377–390 (2020).Two new species of Boesenbergia (Zinginberaceae) from Palawan, Philippines
R.R. Rubite, M. Irabagon, D. Palacio, Y.P. Ang, & R.A.A. Bustamante. Phytotaxa 439 (2020) 291. Begonia caramoanensis (Begoniaceae) A new species from camarines sur, Philippines.
J.M. Agacoilli, J. Barcelona, & P.B. Pelser. Phytotaxa 435 (2020) 26. Melastoma malabituin (Melastomaceae): A new species from northern Luzon, Philippines
J. Tandang, E. Galindon, F. Tadiosa, V. Coritico, Amoroso, Lagunday, R.A.A. Bustamante, D. Pennys, & P. Fritsch. PhytoKeys 139:91-97 (2020) . Dilochia deleoniae (Orchidaceae), A new species from Mindanao, Philippines
W.L.A. Hetterscheid, M.P. Medecilo, J.R.C. Callado, & A. Galloway. Blumea 65, 2020: 1–9. New species of Amorphophallus (Araceae) in the Philippines and an updated key
J. van Beijnen & E.D. Jose. The Palawan Scientist, 12 (2020). Botanical observations from a threatened riverine lowland forest in Aborlan, Palawan, Philippines
A.S. Robinson, S. Zamudio, & R. Caballero. Phytotaxa 423 (2019) 22. Nepenthes erucoides (Nepenthaceae), An ultramaficous micro-endemic from Dinagat islands province, Northern Mindanao, Philippines
R.V.A. Docot, N.P. Mendez, & C.B.M. Domingo. Gardens’ Bulletin Singapore 71 (2019) 448. A new species of hornstedia and a new species record of Globba (Zingiberaceae) from Palawan, Philippines
References
External links
Philippine Taxonomic Initiative
Taxonomy (biology) organizations
Organizations based in the Philippines | Philippine Taxonomic Initiative | [
"Biology"
] | 2,310 | [
"Taxonomy (biology) organizations",
"Taxonomy (biology)"
] |
65,740,475 | https://en.wikipedia.org/wiki/Pekada | Pekada (), or pekadaya, are the decorative wooden pillar heads/brackets at the top of a stone or wooden column (or a pilaster), known as kapa, supporting a beam or dandu. It is a unique feature of Kandyan architecture.
The pekada is a cubic intermediate structural element in joinery and the interface between a beam and a column, which transfers the load from the roof to the ground. It is a separately carved
capital or bracket which intervenes between a pillar and a beam which it is to carry. The pekada is made of two pieces, fitting together, and when these are crossed together, the four faced bracket is completed; the top of the pillar itself is mortised into the bracket through the centre of the parts crossed. This form of arrangement allows a certain amount of flexibility whilst maintaining the structural stability of the beam and pillar. Pekada provides a method of transferring lateral as well as vertical loads of beams (especially when they cross at right angles) to pillars without inducing high local stresses at the connection points.
Pekadas date from the Gampola period (1341-1415) but were more predominantly used during the Kandyan period (1591–1815).
Pekadas can be still seen clearly in Ambalama (wayside rest structures), the Magul Maduwa or Royal Audience Hall in Kandy and the Embekka Devalaya (built during the reign of King Rajadhi Rajasingha). They are designed to be viewed from below and feature traditional pendant (inverted) lotus or binara mala motifs, often with the figure of a dancer in the downward face of the flower or a bird in place of the petals. Pekadas have also been used on more modern buildings such as the Trinity College Chapel, where they have been carved out of Gummalu, a local hardwood and the Lake House building, where they are constructed out of concrete.
See also
Kandyan roof
Madol Kurupawa
Further reading
References
External links
Timber framing
Buddhist architecture
Vernacular architecture
Indigenous architecture
Architecture in Sri Lanka | Pekada | [
"Technology"
] | 432 | [
"Structural system",
"Timber framing"
] |
65,740,749 | https://en.wikipedia.org/wiki/Sinai%E2%80%93Ruelle%E2%80%93Bowen%20measure | In the mathematical discipline of ergodic theory, a Sinai–Ruelle–Bowen (SRB) measure is an invariant measure that behaves similarly to, but is not an ergodic measure. In order to be ergodic, the time average would need to be equal the space average for almost all initial states , with being the phase space. For an SRB measure , it suffices that the ergodicity condition be valid for initial states in a set of positive Lebesgue measure.
The initial ideas pertaining to SRB measures were introduced by Yakov Sinai, David Ruelle and Rufus Bowen in the less general area of Anosov diffeomorphisms and axiom A attractors.
Definition
Let be a map. Then a measure defined on is an SRB measure if there exist of positive Lebesgue measure, and with same Lebesgue measure, such that:
for every and every continuous function .
One can see the SRB measure as one that satisfies the conclusions of Birkhoff's ergodic theorem on a smaller set contained in .
Existence of SRB measures
The following theorem establishes sufficient conditions for the existence of SRB measures. It considers the case of Axiom A attractors, which is simpler, but it has been extended times to more general scenarios.
Theorem 1: Let be a diffeomorphism with an Axiom A attractor . Assume that this attractor is irreducible, that is, it is not the union of two other sets that are also invariant under . Then there is a unique Borelian measure , with , characterized by the following equivalent statements:
is an SRB measure;
has absolutely continuous measures conditioned on the unstable manifold and submanifolds thereof;
, where is the Kolmogorov–Sinai entropy, is the unstable manifold and is the differential operator.
Also, in these conditions is a measure-preserving dynamical system.
It has also been proved that the above are equivalent to stating that equals the zero-noise limit stationary distribution of a Markov chain with states . That is, consider that to each point is associated a transition probability with noise level that measures the amount of uncertainty of the next state, in a way such that:
where is the Dirac measure. The zero-noise limit is the stationary distribution of this Markov chain when the noise level approaches zero. The importance of this is that it states mathematically that the SRB measure is a "good" approximation to practical cases where small amounts of noise exist, though nothing can be said about the amount of noise that is tolerable.
See also
Quasi-invariant measure
Krylov–Bogolyubov theorem
Gibbs measure
Notes
References
Ergodic theory | Sinai–Ruelle–Bowen measure | [
"Mathematics"
] | 554 | [
"Ergodic theory",
"Dynamical systems"
] |
65,741,913 | https://en.wikipedia.org/wiki/Introduction%20to%20Solid%20State%20Physics | Introduction to Solid State Physics, known colloquially as Kittel, is a classic condensed matter physics textbook written by American physicist Charles Kittel in 1953. The book has been highly influential and has seen widespread adoption; Marvin L. Cohen remarked in 2019 that Kittel's content choices in the original edition played a large role in defining the field of solid-state physics. It was also the first proper textbook covering this new field of physics. The book is published by John Wiley and Sons and, as of 2018, it is in its ninth edition and has been reprinted many times as well as translated into over a dozen languages, including Chinese, French, German, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Romanian, Russian, Spanish, and Turkish. In some later editions, the eighteenth chapter, titled Nanostructures, was written by Paul McEuen. Along with its competitor Ashcroft and Mermin, the book is considered a standard textbook in condensed matter physics.
Background
Kittel received his PhD from the University of Wisconsin–Madison in 1941 under his advisor Gregory Breit. Before being promoted to professor of physics at UC Berkeley in 1951, Kittel held several other positions. He worked for the Naval Ordnance Laboratory from 1940 to 1942, was a research physicist in the US Navy until 1945, worked at the Research Laboratory of Electronics at MIT from 1945 to 1947 and at Bell Labs from 1947 to 1951, and was a visiting associate professor at UC Berkeley from 1950 until his promotion.
Henry Ehrenreich has noted that before the first edition of Introduction to Solid State Physics came out in 1953, there were no other textbooks on the subject; rather, the young field's study material was spread across several prominent articles and treatises. The field of solid state physics was very new at the time of writing and was defined by only a few treatises that, in the Ehrenreich's view, expounded rather than explained the topics and were not suitable as textbooks.
Content
The book covers a wide range of topics in solid state physics, including Bloch's theorem, crystals, magnetism, phonons, Fermi gases, magnetic resonance, and surface physics. The chapters are broken into sections that highlight the topics.
Reception
Marvin L. Cohen and Morrel H. Cohen, in an obituary for Kittel in 2019, remarked that the original book "was not only the dominant text for teaching in the field, it was on the bookshelf of researchers in academia and industry throughout the world", though they did not provide any time frame on when it may have been surpassed as the dominant text. They also noted that Kittel's content choices played a large role in defining the field of solid-state physics.
The book is a classic textbook in the subject and has seen use as a comparative benchmark in the reviews of other books in condensed matter physics. In a 1969 review of another book, Robert G. Chambers noted that there were not many textbooks covering these topics, as "since 1953, Kittel's classic Introduction to Solid State Physics has dominated the field so effectively that few competitors have appeared", noting that the third edition continues that legacy. Before continuing, the reviewer noted that the book was too long for some uses and that less thorough works would be welcome.
Several notable reviews of the first edition were published in 1954, including Arthur James Cochran Wilson, Leslie Fleetwood Bates, and Kenneth Standley, among others.
Gwyn Owain Jones reviewed the book in 1955.
The second edition of the book was reviewed by Robert W. Hellwarth in 1957 and Leslie Fleetwood Bates, among others.
The third edition of the book also received reviews, including one by Donald F. Holcomb.
A German translation of the book has also received several reviews.
Publication history
Original editions
Reprints
Foreign translations
See also
List of textbooks on classical mechanics and quantum mechanics
List of textbooks in electromagnetism
References
External links
1953 non-fiction books
1956 non-fiction books
1967 non-fiction books
1971 non-fiction books
1976 non-fiction books
1986 non-fiction books
1996 non-fiction books
2005 non-fiction books
2018 non-fiction books
Physics textbooks
Condensed matter physics | Introduction to Solid State Physics | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 847 | [
"Phases of matter",
"Condensed matter physics",
"Matter",
"Materials science"
] |
65,742,191 | https://en.wikipedia.org/wiki/Bilibili%20Video%20Satellite | Bilibili Video Satellite was launched by Long March 11 on Yellow Sea waters on 15 September 2020. It was China's first custom-made satellite by Chinese internet company Bilibili. The satellite was developed by Chang Guang Satellite Technology Corporation.
Mission
Bilibili vice chairman and COO Li Ni (李旎) said in 2020 that the satellite would be able to access remote sensing video and could be used to make popular science videos, which was to include science, technology, humanities and other aspects to encourage the younger generation to remain curious and explore. Farther into the future, the satellite is planned to also customize filming missions for Bilibili users, using the satellite to take orbital photos of the Earth.
Specifications
The satellite was equipped with two high-performance payload cameras, intended to obtain color video images with resolution better than covering an area of .
History
On 11 May 2020, the initial satellite was transported to Jiuquan Satellite Launch Center. In June 2020, Bilibili announced that the satellite was to have been launched in late June, saying it was "a Children's Day gift". In the event, the launch was delayed.
On 10 July 2020, the initial Bilibili Video Satellite satellite was launched from the Jiuquan Center by the first Kuaizhou 11 rocket. However, the rocket flew abnormally and failed to reach orbit. Bilibili said then that the satellite launch program would continue.
In September 2020, another satellite was launched by a Long March 11 from the Yellow Sea and successfully reached orbit.
See also
Jilin-1
References
Earth observation satellites of China
Commercial Earth imaging satellites
Satellite video | Bilibili Video Satellite | [
"Astronomy"
] | 332 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
65,742,751 | https://en.wikipedia.org/wiki/Microsoft%20Ancient%20Lands | Microsoft Ancient Lands is a 1994 "infotainment" multimedia software title, part of the Microsoft Home series, covering the ancient civilizations of Egypt, Greece, and Rome. It featured 21 animations and video sequences and 5 hours of video, and allowed users to learn about aspects of life like cooking and working.
In 1995, a computer lab was available at Andover Elementary School with Microsoft products including Ancient Lands.
The Chicago Times felt the title would appeal to teachers and parents who wanted children to be interested in history and culture. The Washington Post thought it is easy to be wrapped up in the title's wealth of information. PC Mag wrote the title could inspire children to visit a museum.
References
Ancient Lands
Multimedia software
Infotainment | Microsoft Ancient Lands | [
"Technology"
] | 147 | [
"Multimedia",
"Multimedia software"
] |
65,742,970 | https://en.wikipedia.org/wiki/Clara%20Lim-Sylianco | Clara Y. Lim-Sylianco (18 August 1925 – 23 July 2013) was a Filipino chemist who was granted the title of National Scientist of the Philippines in 1994. Lim-Sylianco's research focused on mutagens, antimutagens, and bio-organic mechanisms. She has published articles, books, and monographs in organic chemistry, biochemistry, genetic toxicology, and molecular nutrition. Also an educator, Lim-Sylianco has written books that are used as reference texts in college chemistry courses in the Philippines.
Education
Lim-Sylianco received an associate degree for the pre-medicine program at Silliman University in 1947. However, she switched out of the Medicine track shortly after to pursue a bachelor's degree in chemistry, where she graduated as magna cum laude in 1949. Lim-Sylianco then pursued a master's in Chemistry at University of the Philippines in 1949. There, she worked as a research assistant until 1951 and later took on an instructor role until she graduated in 1953. After receiving a Fulbright scholarship, she went to the United States to pursue her doctoral studies in biochemistry and organic chemistry at the University of Iowa. She was a research assistant in the university's Department of Pediatrics from 1953 to 1955 and a research fellow in the Department of Biochemistry from 1955 to 1957.
Career and research
Lim-Sylianco moved back to teach at the chemistry and biochemistry departments of the University of the Philippines in 1957. From 1970 to 1973, she served as a consultant for the National Institute of Science and Technology. Lim-Sylianco was a prolific researcher, making contributions to several fields such as environmental mutagens and anti-mutagens, biochemical nutrition, bioorganic mechanisms, and mutagenicity of Philippine medical plants (trilaurin, trilinolein, etc.). In 1989, she became a member of the International Advisory Committee on Anti-mutagens. She was also dedicated to chemical education and wrote textbooks on organic chemistry and molecular biochemistry that were adopted nationally. These include: Principle of Organic Chemistry, 5th ed., 1975; Modern Biochemistry, 1976; Monograph Series on Molecular Biochemistry: Nucleic Acids, Protein, Carbohydrates, Lipids, 1974; Laboratory Manual in Organic Chemistry, 1965; and Laboratory Manual in Biochemistry, 1961.
Awards and recognition
In 1958, she became a Fellow of the Royal Society.
In 1977, she received the Gregario Y. Zara Award.
From 1974 to 1977, she was the University of the Philippines Endowment Professional Chair in Chemistry.
She was recognized as a National Scientist of the Philippines in 1994.
References
1925 births
2013 deaths
Organic chemists
National Scientists of the Philippines
Filipino chemists
Filipino women chemists
20th-century Filipino women scientists
Fellows of the Royal Society of Chemistry
People from Negros Oriental
Silliman University alumni
University of the Philippines alumni
University of Iowa alumni
Academic staff of the University of the Philippines | Clara Lim-Sylianco | [
"Chemistry"
] | 595 | [
"Organic chemists"
] |
65,743,208 | https://en.wikipedia.org/wiki/Diffusion%20Inhibitor | The Diffusion Inhibitor is the first known attempt to build a working fusion power device. It was designed and built at the National Advisory Committee for Aeronautics' (NACA) Langley Memorial Aeronautical Laboratory beginning in the spring of 1938. The basic concept was developed by Arthur Kantrowitz and his boss, Eastman Jacobs. They deliberately picked a misleading name to avoid the project being detected by NACA's headquarters in Washington, D.C., as they believed it would immediately be cancelled if their superiors learned of it.
In overall terms, the device was very similar to the toroidal magnetic confinement fusion reactor designs that emerged in the 1950s and 60s, with a strong physical resemblance to the z-pinch and tokamak devices. The major difference was that it used radio waves to heat the plasma while using the magnetic field for confinement alone, not compression. After several early experiments which showed no sign of high-energy releases, NACA director George William Lewis happened into the lab and immediately shut it down.
History
In 1936, Arthur Kantrowitz, a recent physics graduate from Columbia University, joined NACA's Langley Memorial Aeronautical Laboratory. In early 1938 he read an article that noted Westinghouse had recently purchased a Van de Graaff generator and concluded the company was beginning research into nuclear power, following the footsteps of Mark Oliphant who demonstrated fusion of hydrogen isotopes in 1932 using a particle accelerator. His direct supervisor, Eastman Jacobs, also expressed an interest in the concept when Kantrowitz showed him the article.
Kantrowitz began canvassing the literature and came across Hans Bethe's paper in Reviews of Modern Physics about the known types of nuclear reactions and Bethe's speculations on the ones taking place in stars, work that would lead to the Nobel Prize in Physics. This led Kantrowitz to consider the concept of heating hydrogen to the temperatures seen inside stars, with the expectation that one could build a fusion reactor. The easiest reaction in the list was deuterium-deuterium, but having only been discovered in 1932, the supply of deuterium was extremely limited. A pure hydrogen-hydrogen reaction was selected instead, although this would require much higher temperatures to work.
Kantrowitz's idea was to use radio frequency signals to heat a plasma, in the same way that a microwave oven uses radio signals to heat food. The system did not have to use microwave frequencies, however, as the charged particles in a plasma will efficiently absorb a wide range of frequencies. This allowed Kantrowitz to use a conventional radio transmitter as the source, building a 150 W oscillator for the purpose.
In order to produce any detectable level of fusion reactions, the system would have to heat the plasma to about 10 million degrees Celsius, a temperature that would melt any physical container. At these temperatures, even the atoms of the fuel itself break up into a fluid of separate nuclei and electrons, a state known as a plasma. Kantrowitz concluded the simplest solution was to use magnetic fields to confine the plasma because plasmas are electrically charged so their movement can be controlled by magnetic fields.
When placed within a magnetic field, the electrons and protons of a hydrogen plasma will orbit around the magnetic lines of force. This means that if the plasma were within a solenoid, the field would keep the particles confined away from the walls but they would be free to travel along the lines and out the ends of the solenoid. At fusion temperatures, the particles are moving at the equivalent of thousands of miles per hour, so this would happen almost instantly. Kantrowitz came to the conclusion that many others did: The simple solution is to bend the solenoid around into a circle so the particles would flow around the resulting ring-shaped toroidal enclosure.
Jacobs approached the lab's director, George W. Lewis, to arrange a small amount of funding, explaining that such a system might one day be used for aircraft propulsion. To disguise the actual purpose from NACA leadership, they called it the "Diffusion Inhibitor". Lewis agreed to provide $5,000 (). The torus was wound with copper magnet cables which were cooled by water, and for a power source, they connected it to the motor circuits of a wind tunnel Jacobs had built. The idea was to measure the resulting fusion reactions by their X-rays, which are emitted from very hot objects.
Because the city's power supply was limited, the wind tunnel was only allowed to operate late at night or early morning and for no more than half an hour at maximum power. Using film developed for taking dental x-rays as their detector, the two fired up the machine but found no signal. Believing the problem was that the radio oscillator didn't have enough power, they tried again while manually holding in the circuit breakers to supply more current. Again, nothing appeared on the film. They concluded that something was causing the plasma to be lost from the center of the reactor, but did not have an obvious solution.
No further experiments were carried out. Shortly after the first runs, Lewis visited the lab, listened to Jacobs's explanation of the system, and immediately shut it down.
It would later be understood that the simple torus design does not correctly confine a plasma. When a solenoid is bent around into a circle, the magnets ringing the container end up being spread apart from each other on the outside circumference. That results in the field being weaker on the outside of the container than the inside. This asymmetry causes the plasma to drift away from the center, eventually hitting the walls.
References
Citations
Bibliography
Fusion power
Fusion reactors | Diffusion Inhibitor | [
"Physics",
"Chemistry"
] | 1,148 | [
"Nuclear fusion",
"Fusion reactors",
"Fusion power",
"Plasma physics"
] |
61,912,781 | https://en.wikipedia.org/wiki/Underwater%20Association | The Underwater Association (UA) was a research association focused on the conduct of research underwater by diving scientists and archaeologists. It was established by a group of UK scientists in Malta in 1966 to assist in the organisation and publication of British diving science. Membership grew to over 400, with approximately one third joining from outside the UK. From 1972 to 1979 the UA published a Code of Practice for scientific diving. This was expanded in 1987 and 1990 to form the UNESCO Code of practice. Membership declined in the late 1980s, and the UA merged with the Society for Underwater Technology in 1992.
Background
The Underwater Association grew out of the popularity of scuba sports diving clubs in British universities in the 1950s and 60s. Diving became popular after the introduction of the first successful and safe open-circuit scuba set, the Aqua-Lung, in the 1940s, and clubs were established in many British universities from 1957 onwards. Members of these clubs, and of research institutions, used scuba diving to pursue various scientific projects under water. Some projects involved the study of diver physiology and psychology, while others made use of diving to study marine biology, underwater archaeology, geology, physics and other topics. Members of the Cambridge University Underwater Exploration Group and Imperial College London were particularly active. They ran expeditions to Malta in the early 1960s, and enjoyed close cooperation with the Royal Navy which provided compressed air and a recompression chamber. In 1965 five different scientific diving teams were active in Malta. The different teams were organised as follows: The Cambridge University Malta Expedition 1965, an undergraduate group studying diurnal behaviour in marine invertebrates (winners of the first ever Duke of Edinburgh/British Sub-Aqua Club award for diving science); and a group from Oxford University, studying mainly algae and geology. There was also a Vision Group from various institutions, studying the visibility of underwater objects and the perception of size and distance, a group led by John Woods from the Physics Department Imperial College London studying thermocline instability; and a Helium Group, led by Nic Flemming from Cambridge University, studying the psychological and ergonomic efficiency of divers breathing heliox and air at a depth of 60 m. In total, 32 divers were involved in these projects. The groups shared many facilities and a conference was organised to present the results in late 1965, with the papers published in 1966. After this publication, the group established an association as a company limited by guarantee and which was registered as a charitable organization.
Establishment of the Underwater Association
The Underwater Association for Malta 1966 was established under that name in 1966 to assist in the organisation and publication of British diving science. The first organising committee consisted of John N. Lythgoe (Institute of Ophthalmology, London), John D. Woods (Physics Department, Imperial College, London), Nicholas C. Flemming (Pembroke College, Cambridge), Anthony Larkum (Botany, Cambridge), Andrew E. Dorey (Zoology, Bristol), Christopher C. "Bill" Hemmings (Fisheries Laboratory, Aberdeen). Bill Hemmings was appointed the first Chair. Subsequent Chairs were Nic Flemming, John Lythgoe and Richard Pagett. As the Association expanded and broadened its range of international recruitment, the name was shortened to the Underwater Association. After a few years the use of Malta as a central base for multiple projects was abandoned, and the Association expanded its objectives to promote underwater science at any location, attracting one third of its membership from outside the UK. The Underwater Association corresponded and collaborated with equivalent voluntary bodies in other countries, especially the American Academy of Underwater Sciences in the USA. The methods and goals of the Underwater Association helped equivalent bodies to develop in South Africa and Australia.
Symposia and UA publications
The UA held its first symposium in 1965 to discuss the results of that year's expeditions. It took place in the Physics Department of Imperial College London, on 29 October. The resulting papers, and those of symposia from 1966 to 1969, were published in booklet form. The proceedings volumes were reviewed in maritime research journals for the information of other marine scientists. Woods and Lythgoe in 1971 and Drew, Lythgoe and Woods in 1976 also published books on underwater science with contributions from members of the UA and elsewhere. The Association also published a newsletter several times each year, circulated by post, which was an essential component of its success in the days before digital communications. Edward Drew and Helen Ross were newsletter editors for much of this time. Copies of most of the UA publications on the proceedings of symposia are held by the library of the National Oceanography Centre, Southampton.
Typical publications in different disciplines
The Underwater Association provided a vehicle for marine scientists who used diving to pool experiences, learn different techniques, experiment with different breathing gas mixtures and diving gear, and to publish their results in a way that emphasised the effectiveness of diving, as well as the skills needed to work efficiently underwater. This achievement coexisted with routine publishing in the mainstream single-discipline refereed journals that demonstrate the high quality of the research. Published papers by Members in the Proceedings volumes and other academic journals included research on diving medicine, psychology, marine biology, fisheries, marine geology, marine physics, archaeology, and oceanographic engineering. The Underwater Association enabled many young marine scientists to develop their careers at a time when diving was not a common research method. The following selected citations illustrate some significant papers in the disciplines of Marine Physics, Psychology of perception, Geoarchaeology, Archaeology, Marine botany, Marine algae, Marine zoology, the psychology of memory in different environments, and diving physiology.
Role in development of UK Codes of Practice for Scientific Diving
During the early 1970s there were increasing numbers of accidents to divers operating commercially in the North Sea oil fields. The UK Health and Safety Executive (HSE) published a consultative document on proposed new regulations for divers at work in 1978, and new statutory regulations came into force in 1981. These were updated in 1997. The Underwater Association, whose members had an accident-free safety record, published an advisory Code of Practice for Scientific Diving in 1972, which was revised and updated in 1974, after which it was adopted as the standard for the Natural Environment Research Council (NERC) and other governmental research diving organisations. This code was circulated internationally, which led to the convening of a UNESCO committee of the Intergovernmental Oceanographic Commission, whose purpose was to publish an international version, compatible with the safety laws in many countries.
NERC, a UK government agency which employed marine scientists in several institutes, adopted the UA Code of Practice and co-published it through several editions (Code in references).The Royal Geographical Society Expedition Advisory Centre recommended the UA Code for use in diving research projects (Palmer).The UA Code helped in the negotiations with the HSE, firstly to obtain Exemptions for Scientific Diving (HSE), and later to create new regulations for specialised diving groups through supervisory Approved Codes of Practice such as the Scientific and archaeological diving projects: Diving at work regulations 1997. The negotiations on safety also led to the formation of the Scientific Diving Supervisory Committee as an advisory body for UK governmental research groups. Reciprocal standards of training and safety for scientific diving were also agreed throughout European agencies and national bodies.
Merger with the Society for Underwater Technology
The Underwater Association performed a vital role in the early stages of scientific diving, but ceased to function in 1992. The situation had changed since the 1960s, when it was very difficult for diving scientists to share expertise, and scientific papers in narrow-discipline journals seldom mentioned the use of diving. Before the days of digital search engines, it was hard to assess the scope of underwater observations, or to learn from the experimental techniques of other researchers. The best way to develop underwater research was to organise national and international meetings, and to publish the proceedings. When digital media and citation indices increased, academics preferred to publish in journals specific to their own disciplines rather than in general diving publications, and they did not need to attend meetings devoted to diving science. Diving for research purposes had become a common practice. As membership declined, a merger with the Society for Underwater Technology (SUT) was organised by John Bevan.
References
Marine biology
Scientific organizations established in 1966
Underwater diving organizations
Scientific organizations disestablished in the 1990s | Underwater Association | [
"Biology"
] | 1,672 | [
"Marine biology"
] |
61,914,077 | https://en.wikipedia.org/wiki/Russell%20Marcus | Russell Marcus is a philosopher specializing in philosophy of mathematics and the pedagogy of philosophy. He is Chair of Philosophy at Hamilton College and president of the American Association of Philosophy Teachers.
Education and career
Prior to his work in philosophy, Marcus taught mathematics and other subjects at high schools in New York City and Costa Rica. He received his bachelor of arts in philosophy at Swarthmore College in 1988. He received his doctorate from the Graduate Center of the City University of New York in 2007, where he wrote his dissertation "Numbers without Science". While at graduate school, he taught philosophy and mathematics at Queens College, Hofstra University and the College of Staten Island. He began teaching at Hamilton College in 2007, later setting up the Hamilton College Summer Program in Philosophy. He gained tenure in 2016 and was appointed Chair of Philosophy in 2020. In 2020, he won the American Philosophical Association's Prize for Excellence in Philosophy Teaching which "recognizes a philosophy teacher who has had a profound impact on the student learning of philosophy in undergraduate and/or pre-college settings", being cited as an "important scholar of teaching and learning in philosophy" for his summer program and "inventive team-based pedagogies and exemplary scaffolded assignments".
Books
References
Further reading
Year of birth missing (living people)
Living people
Philosophers of mathematics
Philosophers of education
Hamilton College (New York) faculty
CUNY Graduate Center alumni
Swarthmore College alumni | Russell Marcus | [
"Mathematics"
] | 292 | [
"Philosophers of mathematics"
] |
61,915,261 | https://en.wikipedia.org/wiki/Vital%20effects | Vital effects are biological impacts on geochemical records. Many marine organisms, ranging from zooplankton (e.g. foraminifera) to phytoplankton (e.g diatoms) to reef builders (e.g. coral), create shells or skeletons from chemical compounds dissolved in seawater. This process, which is also called biomineralization, therefore records the chemical signature of seawater during the time of shell formation. However, different species have different metabolism and physiology, causing them to create their shells in different ways. These biological distinctions cause species to record slightly different chemical signatures in their shells; these differences are known as vital effects.
Importance to scientific research
Vital effects are relevant to study because of their influence on paleoclimatic interpretations. Scientists study the isotopic composition of marine organisms’ shells that have been preserved in marine sediment in order to reconstruct past environmental conditions. The earliest example of this work is using oxygen isotopes from the calcium carbonate (CaCO3) in belemnites to reconstruct paleotemperatures. It is important to understand vital effects because they affect how paleoclimatic data are interpreted, which influences how scientists predict future impacts of climate change.
Examples
Foraminifera
Foraminifera are widely used for paleoclimatic and paleoceanographic research because of the oxygen isotopes in their calcium carbonate shells. Oxygen isotopes, or δ18O, are used to interpret past temperature and ice volume. Foraminifera also incorporate trace amounts of boron in their shells, which is used to reconstruct past pH. Foraminiferal isotopic composition is affected by factors such as algal symbionts or species-specific physiology. The influence of such vital effects can be determined via culture experiments.
Coral
Similar to foraminifera shells, the isotopic composition of coral skeletons is used to reconstruct past temperature, CO2 concentrations, and pH. Vital effects arise from algal symbionts and biological responses to changes in conditions such as pH. Again, culture experiments are used to quantify vital effects and calibrate the use of coral isotopic composition as a proxy.
Diatoms
Diatoms can also be used to study oxygen isotopes and are especially useful in regions of the ocean where foraminifera do not preserve in marine sediments. One example of vital effects in diatoms is a difference in δ18O between two different species, Coscinodiscus marginatus and Coscinodiscus radiatus, which is attributed to their difference in size.
References
Geochemistry | Vital effects | [
"Chemistry"
] | 543 | [
"nan"
] |
61,915,279 | https://en.wikipedia.org/wiki/OneZoom | The OneZoom Tree of Life Explorer is a web-based phylogenetic tree software. It aims to map the evolutionary connection of all known life. As of 2023 it includes over 2.2 million species.
Organisation
OneZoom was originally invented by James Rosindell and is a charity registered in London. It is sponsored by individuals such as Richard Dawkins.
Tree of Life Explorer
The design is based on the pythagoras tree; beside a default spiral design there are other options, such as polytomy.
Leaves and nodes provide links to other websites, such as Wikipedia, Encyclopedia of Life or the NCBI taxonomy browser. The leaves representing single species are colour-coded according to their IUCN extinction risk, with red indicating a threatened species, black representing a recently extinct species, and grey representing species with unknown extinction risk.
See also
List of phylogenetic tree visualization software
References
External links
OneZoom Tree of Life Explorer
Interview with Luke Harmon in Utah Public Radio
Charities based in London
Phylogenetics software
Visualization software
Tree of life (biology)
Educational charities based in the United Kingdom
International charities | OneZoom | [
"Biology"
] | 223 | [
"Tree of life (biology)"
] |
61,915,503 | https://en.wikipedia.org/wiki/Clock%20of%20Flowing%20Time | The Clock of Flowing Time () is a high water clock extending over three floors in the Berlin Europa-Center. The clock was designed by the French artist Bernard Gitton and set up in 1982.
The water clock displays the time by filling glass spheres with brightly colored liquid, in a cycle that repeats every 12 hours. The whole system is controlled by a pendulum swinging in the lower half of the clock.
References
External links
Official web page (archived in January 2019)
colored liquid video
Individual clocks
Water clocks
Buildings and structures in Charlottenburg-Wilmersdorf
Clocks in Germany
1982 establishments in West Germany | Clock of Flowing Time | [
"Physics"
] | 120 | [
"Spacetime",
"Physical quantities",
"Time",
"Time stubs"
] |
61,916,414 | https://en.wikipedia.org/wiki/Benthic-pelagic%20coupling | Benthic-pelagic coupling are processes that connect the benthic zone and the pelagic zone through the exchange of energy, mass, or nutrients. These processes play a prominent role in both freshwater and marine ecosystems and are influenced by a number of chemical, biological, and physical forces that are crucial to functions from nutrient cycling to energy transfer in food webs.
Description
The benthic and pelagic zones are interconnected through nutrient (nitrogen, phosphorus, and silicate) exchange from the sediment that help fuel phytoplankton primary production in the water column, which in turn, provide organic substrate for regeneration in sediments by microbes and macrofauna. These exchanges have seasonal variability as temperature and light conditions that drive primary production and sedimentation patterns change. Accumulation of nutrients during winter months generally results in a strong peak in phytoplankton production in spring followed by a peak in sedimentation. In the summer, pelagic recycling of primary production is more efficient and sedimentation generally lower.
The depth of an aquatic ecosystem is a key factor for benthic-pelagic exchanges because it determines the proximity and degree of interactions between the two environments. Coupling is stronger in shallow waters, such as in lakes and in coastal areas because primary productivity is generally higher in these areas where a higher amount of fresh organic matter from either photosynthesis or fecal matter can reach the bottom to fuel benthic fauna, which in turn remineralize and respire organic matter that supplies essential nutrients for primary production at the surface. Stratification of the water column, whether by temperature or salinity, also regulates the degree of exchange between benthic and pelagic habitats.
Oxygen concentrations and biological interactions, such as predation and competition, will also influence benthic community structure and biomass. For example, benthic macrofauna, such as polychaetes and bivalves, are important food sources for demersal fish, including commercially important species such as flatfish and cod.
Mechanisms
Organism movement
Diel vertical migrations (DVM) of fishes, zooplankton, and larger invertebrates, such as cephalopods and jellyfish, from the surface to the bottom can transfer nutrients and detritus from the pelagic zone to the benthos. Zooplankton, for example, vertically transport items such as organic carbon, nutrients, parasites, and food resources throughout the water column. Particulates (fecal pellets) and dissolved organic carbon produced by these organisms in the water column constitute marine snow, which supports microbial production at the benthos in what is known as the 'biological pump.'
These daily migrations are along a vertical gradient were movements are typically downward by day and an upward at night in response to several factors, such as predator avoidance, food availability, and light intensity.
Movement driven by life-history stages and feeding patterns also plays a role in benthic-pelagic coupling. Many aquatic organisms inhabit have both pelagic and benthic life stages, such as benthic macrofauna that have pelagic larval stages before settling on the sediment. Organisms who occupy both benthic and pelagic habitats as part of their life history help maintain adult populations and community structure, and serve as inputs essential for ecological interactions such as predation, competition, and parasitism.
Sediment-dwelling organisms are also involved in benthic-pelagic coupling by disturbing the sediment to feed on organic matter trapped between sediment grains or to hide from predators. This is known as bioturbation, which stimulates mineralization of organic matter and the release of nutrients (Hansen et al. 1998; Lohrer et al. 2004; D’Andrea and DeWitt 2009), thereby affecting the growth of phytoplankton in the pelagic zone (Welsh 2003). Bioturbation by macrofauna affects sediment permeability and water content, destabilizes chemical gradients, subducts organic matter, and influences rates of remineralization and inorganic nutrient flux.
Collectively, these outcomes are essential to habitat productivity and overall ecosystem function.
Trophic interactions
How organisms interact will also determine the degree of benthic-pelagic coupling. These interactions will differ based largely on the species involved. In both freshwater and marine ecosystems, there are benthic organisms that are preyed upon by both demersal and pelagic fish during various life stages. Benthic organisms can also prey upon pelagic species. Benthic suspension feeders, such as bivalves, can exert considerable grazing
pressure on phytoplankton and microzooplankton. Thus, benthic and pelagic fauna can act as habitat couplers by consuming resources originating from either the water column or the sediment.
On rocky intertidal shores, the effects of nearshore currents on phytoplankton and sea star propagules influence the benthic community structure of mussels and predation pressure by sea stars.
Detritivores inhabiting benthic areas derive energy from sinking pelagic detritus and are then consumed by either benthic or pelagic predators, impacting community structure.
Benthic and pelagic domains are further linked by pelagic predators such as tuna and swordfish feeding also on demersal resources, while pelagic preys such as sardines and anchovies may feed demersal predators.
Biogeochemical cycling
The benthic biogeochemical processes are essentially driven by pelagic processes, fueled by the deposition of pelagic material (e.g., organic matter, calcium carbonate). In response, sediments transform the deposited material (such as through degradation and dissolution) back into nutrients available for uptake in the water column.
Part of those products becomes available for bacterial and phytoplankton production that ultimately may sink to the seafloor to fuel the benthic communities again.
Anthropogenic and climate change impacts
Anthropogenic pressures regulate benthic–pelagic coupling directly and indirectly through their effects on the physical (e.g., salinity, oxygen, temperature) and biological (e.g., species, communities, functional traits) components of ecosystems. In coastal and estuarine
ecosystems, climate change, nutrient loading, and fishing have been shown to have direct effects on benthic–pelagic coupling with clear consequences for ecosystem function. For example, increased water temperatures in Narragansett Bay have caused shifts in the timing and a decrease in the magnitude of phytoplankton blooms. This has decreased the deposition of organic material to the benthos and ultimately reduced inorganic nutrient release from the sediment.
Projected changes in nutrients and salinity could have negative effects on the distribution and productivity of mussels and diminish their role in benthic–pelagic exchange. Overall, eutrophication results in an increase in phytoplankton biomass and blooms, altered phytoplankton community structure, and a decrease in benthic primary production.
See also
Marine food web
References
Marine biology | Benthic-pelagic coupling | [
"Biology"
] | 1,462 | [
"Marine biology"
] |
61,920,052 | https://en.wikipedia.org/wiki/Hammer%20Mill%20at%20Dob%C5%99%C3%ADv | The water Hammer Mill (also Upper Hammer Mill, in Czech also Hořejší lub) at Dobřív near Rokycany is a unique technical monument commemorating the 500-year-old tradition of iron processing in this region of the Czech Republic. Within the Czech Republic, it is considered the most important building of its kind. It is the first technical monument in the Plzeň Region, that was declared a national cultural monument in 2010.
The monument is owned by Plzeň Region and administered by the Museum of West Bohemia in Plzeň.
History
The present brick building was constructed at the beginning of the 19th century in the place of older wooden hammer mills from 1658 and 1701. The rich machinery is dated back to the 19th century. Originally, the hammer mill was used to refine blast-furnace raw iron and to produce bar forgings. After the development of later steel industry technologies, the hammer mill changed over to production of heavy forged tools in the late 1860s. In the second half of the 20th century, the production was stopped in the hammer mill and in the ironworks beneath it. The hammer mill became a museum exposition to document the old ways of industrial production
Description
The hammer stands in close proximity to the dam of Huťský pond. The adjacent drive feeds water through a wooden trough to the water wheels that drive the hammering equipment through the transmission system. Originally the iron-mill had five water wheels, today three are functional.
The mill hall dimensions are 32×12 meters. In the interior there are forges, hammers of various sizes, grinding machines, bending machine, drills, presses and various tools. Water wheels power not only the equipment for the production of forged tools, but also the electricity generator. Each water wheel has an output of about 8 kW.
Present
When visiting the exposition it is possible to see how the mill works. While the fire in the forge is burning, and the wheels are spinning the museum guide, a blacksmith, operates a small tail hammer and on the anvil will forge a beautiful nail with a rounded head for the visitor, the same, which is custom-made for historic buildings today. Curious visitors interested in forging can learn a blacksmith's craft in an accelerated course, where they will learn to forge under a small iron-mill.
Reconstruction
In 2011 the iron-mill completed a major repair of the water drive at cost of 11 million CZK. Aged deposits of mud caused the water to stand in the drive and the technical equipment of the hammer mill was out of order. Therefore, it was necessary to completely mud about 900 meters long drive and solidify the banks.
In 2017 the West Bohemian Museum in Plzeň has received financial support (10 millions CZK) from the Integrated Regional Development Fund for the national monument revitalization. The project, scheduled for 2018-19, will restore the technical equipment, some dating from the 19th century. The permanent exposition on the history of the iron-mill, but also on the history of mining and processing of iron ore in the Brdy region will be expanded as well. Both activities date back to the 14th century, when the Rosenberg family founded the first smelters here.
Recognition
The hammer mill is a remarkable technical monument of this type with full equipment proving the original handicraft production commemorating the 500-year tradition of metallurgy in the Brdy region. It was declared a cultural monument in 1958 and a national cultural monument in 2010. It has been part of the Dobřív village monument zone since 1995.
In 2010 the Czech National Bank issued a 2500 CZK commemorative gold coin as part of the Industrial Heritage Sites series. The coin was designed by Jaroslav Veselák.
References
National cultural monuments of the Czech Republic
Buildings and structures in the Czech Republic
Mill museums in the Czech Republic
Hammer mills
Tourist attractions in the Czech Republic
Rokycany District | Hammer Mill at Dobřív | [
"Chemistry"
] | 782 | [
"Metallurgical facilities",
"Hammer mills"
] |
61,920,776 | https://en.wikipedia.org/wiki/Catalytic%20resonance%20theory | In chemistry, catalytic resonance theory was developed to describe the kinetics of reaction acceleration using dynamic catalyst surfaces. Catalytic reactions occur on surfaces that undergo variation in surface binding energy and/or entropy, exhibiting overall increase in reaction rate when the surface binding energy frequencies are comparable to the natural frequencies of the surface reaction, adsorption, and desorption.
History
Catalytic resonance theory is constructed on the Sabatier principle of catalysis developed by French chemist Paul Sabatier. In the limit of maximum catalytic performance, the surface of a catalyst is neither too strong nor too weak. Strong binding results in an overall catalytic reaction rate limitation due to product desorption, while weak binding catalysts are limited in the rate of surface chemistry. Optimal catalyst performance is depicted as a 'volcano' peak using a descriptor of the chemical reaction defining different catalytic materials. Experimental evidence of the Sabatier principle was first demonstrated by Balandin in 1960.
The concept of catalytic resonance was proposed on dynamic interpretation of the Sabatier volcano reaction plot. As described, extension of either side of the volcano plot above the peak defines the timescales of the two rate-limiting phenomena such as surface reaction(s) or desorption. For binding energy oscillation amplitudes that extend across the volcano peak, the amplitude endpoints intersect the transiently accessible faster timescales of independent reaction phenomena. At the conditions of sufficiently fast binding energy oscillation, the transient binding energy variation frequency matches the natural frequencies of the reaction and the rate of overall reaction achieves turnover frequencies greatly in excess of the volcano plot peak. The single resonance frequency (1/s) of the reaction and catalyst at the selected temperature and oscillation amplitude is identified as the purple tie line; all other applied frequencies are either slower or less efficient.
Theory
The basis of catalytic resonance theory utilizes the transient behavior of adsorption, surface reactions, and desorption as surface binding energy and surface transition states oscillate with time. The binding energy of a single species, i, is described via a temporal functional including square or sinusoidal waves of frequency, fi, and amplitude, dUi:
Other surface chemical species, j, are related to the oscillating species, i, by the constant linear parameter, gamma γi-j:
The two surface species also share the common enthalpy of adsorption, delta δi-j. Specification of the oscillation frequency and amplitude of species i and relating γi-j and δi-j for all other surface species j permits determination of all chemical surface species adsorption enthalpy with time.
The transition state energy of a surface reaction between any two species i and j is predicted by the linear scaling relationship of the Bell–Evans–Polanyi principle which relates to the surface reaction enthalpy, ΔHi-j, to the transition state energy, Ea, by parameters α and β with the following relationship:
The oscillating surface and transition state energies of chemical species alter the kinetic rate constants associated with surface reaction, adsorption, and desorption. The surface reaction rate constant of species i converting to surface species j includes the dynamic activation energy:
The resulting surface chemistry kinetics are then described via a surface reaction rate expression containing dynamic kinetic parameters responding to the oscillation in surface binding energy:
,
with k reactions with dynamic activation energy. The desorption rate constant also varies with oscillating surface binding energy by:
.
Implementation of dynamic surface binding energy of a reversible A-to-B reaction on a heterogeneous catalyst in a continuous flow stirred tank reactor operating at 1% conversion of A produces a sinusoidal binding energy in species B as shown. In the transition between surface binding energy amplitude endpoints, the instantaneous reaction rate (i.e., turnover frequency) oscillates over an order of magnitude as a limit cycle solution.
Implications for Chemistry
Oscillating binding energies of all surface chemical species introduces periodic instances of transient behavior to the catalytic surface. For slow oscillation frequencies, the transient period is only a small quantity of the oscillation time scale, and the surface reaction achieves a new steady state. However, as the oscillation frequency increases, the surface transient period approaches the timescale of the oscillation, and the catalytic surface remains in a constant transient condition. A plot of the effective catalytic rate of a reaction with respect to applied oscillation frequency identifies the 'resonant' frequency for which the transient conditions of the catalyst surface match the applied frequencies. The catalytic rate at the resonance frequency exists above the Sabatier volcano plot maximum of a static system with average reaction rates as high as five orders of magnitude faster than that achievable by conventional catalysis.
Surface binding energy oscillation also occurs to different extent with the various chemical surface species as defined by the γi-j parameter. For any non-unity γi-j system, the asymmetry in the surface energy profile results in conducting work to bias the reaction to a steady state away from equilibrium. Similar to the controlled directionality of molecular machines, the resulting ratchet (device) energy mechanism selectively moves molecules through a catalytic reaction against a free energy gradient.
Application of dynamic binding energy to a surface with multiple catalytic reactions exhibits complex behavior derived from the differences in the natural frequencies of each chemistry; these frequencies are identified by the inverse of the adsorption, desorption, and surface kinetic rate parameters. Considering a system of two parallel elementary reactions of A-to-B and A-to-C that only occur on a surface, the performance of the catalyst under dynamic conditions will result in varying capability for selecting either reaction product (B or C). For the depicted system, both reactions have the same overall thermodynamics and will produce B and C in equal amounts (50% selectivity) at chemical equilibrium. Under normal static catalyst operation, only product B can be produced at selectivities greater than 50% and product C is never favored. However, as shown, the application of surface binding dynamics in the form of a square wave at varying frequency and fixed oscillation amplitude but varying endpoints exhibits the full range of possible reactant selectivity. In the range of 1-10 Hertz, there exists a small island of parameters for which product C is highly selective; this condition is only accessible via dynamics.
Mechanisms of Efficient Dynamic Catalysts
Dynamic catalysts that undergo forced variation of free energy surface during a catalytic reaction are called 'programmable catalysts.' Perturbation of the active site with strain, light, or condensed charge modulates the binding energy of adsorbates and transition states to alter the rate, selectivity, and conversion of a catalytic reaction. New opportunities exist with dynamic catalysts and oscillating free energy surfaces not possible with conventional static active sites. However, these opportunities require energy input to modulate the catalyst, raising the issue of efficiency of a programmable catalyst.
A programmable catalyst oscillating between strong and weak binding energies exhibits positive scaling between reaction intermediates; B* and A* both weaken and strengthen in binding energy simultaneously. Under strong binding conditions, A* readily reacts over the transition state to form B*. For weaking catalyst binding conditions, B* readily desorbs to form B(g), as A(g) immediately adsorbs as A* to restart the catalytic cycle. An efficient programmable catalyst converts molecules from reactants to products with every oscillation of binding energy of the active site, such that most active sites on the catalyst surface produce a product molecule for every catalytic oscillation cycle. Of key importance is the height of the transition state barrier in the weak-binding catalyst state; a high barrier creates a ratchet mechanism, whereby B* is prohibited from reacting backwards to A*.
The efficiency of a programmable catalyst can be determined by the metric of the turnover efficiency (ηTOE). The turnover efficiency compares the difference between the time-averaged dynamic turnover frequency of the reaction (TOFdyn) and the steady state turnover frequency (TOFss) to the applied catalytic oscillation frequency, fapp.
Highly efficient programmable catalysts will exhibit turnover efficiencies close to unity (ηTOE ~ 1), indicating that there is parity between the applied frequency and the catalytic turnover frequency.
Of fundamental importance are mechanisms that lead to a reduction in the turnover efficiency. One such catalytic mechanism is the leaky programmable catalyst mechanism. On these dynamic free energy surfaces, the adsorbed surface reactant A* readily reacts to form surface product B* in the strong-binding catalyst state. However, in the weak-binding catalyst state, B* readily reacts backwards to reform A* rather than desorbing to form B(g) in the gas phase. This yields an inefficient programmable catalyst, whereby most input energy to modulate the catalyst between states results in heat generation as molecules interconvert between A* and B*. Programmable catalysts exhibiting the leaky ratchet phenomenon exhibit time-averaged turnover frequencies far from parity with the applied catalytic oscillation frequency, resulting in low turnover efficiency.
An alternative programmable catalytic mechanism leading to reduced turnover efficiency derives from the extent of the surface that participates in the overall reaction. When the programmable catalyst switches to the strong-binding state, A* reacts to B* and equilibrates. However, for systems with comparable free energy of A* and B* in the strong binding state, only a fraction of reactant A* is converted to B*. In this case, only a fraction of surface active sites desorb B* to form B(g) when the catalyst switches to the weak-binding state. Adsorbates of A* that change in binding energy between modulating catalyst states consume energy and release heat without completing the catalytic cycle, yielding an inefficient programmable catalyst.
High turnover efficiency is critical for efficient use of a programmable catalyst. The two key mechanisms leading to lower efficiency, the leaky ratchet and low participating surface mechanisms, can significantly reduce the time-averaged catalytic rate, even orders of magnitude lower than the applied catalyst oscillation frequency.
Characteristics of Dynamic Surface Reactions
Catalytic reactions on surfaces exhibit an energy ratchet that biases the reaction away from equilibrium. In the simplest form, the catalyst oscillates between two states of stronger or weaker binding, which in this example is referred to as 'green' or 'blue,' respectively. For a single elementary reaction on a catalyst oscillating between two states (green & blue), there exists four rate coefficients in total, one forward (k1) and one reverse (k−1) in each catalyst state. The catalyst switches between catalyst states (j of blue or green) with a frequency, f, with the time in each catalyst state, τj, such that the duty cycle, Dj is defined for catalyst state, j, as the fraction of the time the catalyst exists in state j. For the catalyst in the 'blue' state:
The bias of a catalytic ratchet under dynamic conditions can be predicted via a ratchet directionality metric, λ, that can be calculated from the rate coefficients, ki, and the time constants of the oscillation, τi (or the duty cycle). For a catalyst oscillating between two catalyst states (blue and green), the ratchet directionality metric can be calculated:
For directionality metrics greater than 1, the reaction exhibits forward bias to conversion higher than equilibrium. Directionality metrics less than 1 indicate negative reaction bias to conversion less than equilibrium. For more complicated reactions oscillating between multiple catalyst states, j, the ratchet directionality metric can be calculated based on the rate constants and time scales of all states.
The kinetic bias of an independent catalytic ratchet exists for sufficiently high catalyst oscillation frequencies, f, above the ratchet cutoff frequency, fc, calculated as:
For a single independent catalytic elementary step of a reaction on a surface (e.g., A* ↔ B*), the A* surface coverage, θA, can be predicted from the ratchet directionality metric,
Experiments and Evidence
Catalytic rate enhancement via dynamic perturbation of surface active sites has been demonstrated experimentally with dynamic electrocatalysis and dynamic photocatalysis. Those results may be explained in the framework of catalytic resonance theory but conclusive evidence is still lacking:
In 1978, the electro-oxidation of formic acid on a platinum electrode was studied under the application of constant potentials and square-wave pulsed potentials. The latter was found to enhance the current density (and thus catalytic activity) by up to 20 times compared to the potentiostatic conditions, with the optimal wave amplitude and frequency of 600 mV and 2000 Hz, respectively. In 1988, the oxidation of methanol on a platinum electrode was conducted under pulsed potentials between 0.4 and 1.18 V, resulting in an average current almost 100 times higher than the steady-state current at 0.4 V.
Using the formic acid electro-oxidation reaction, oscillation of the applied electrodynamic potential between 0 and 0.8 volts accelerated the formation rate of carbon dioxide more than an order of magnitude higher (20X) than what was achievable on platinum, the best existing catalyst. The maximum catalytic rate was experimentally observed at a frequency of 100 Hz; slower catalytic rates were observed at higher and lower electrodynamic frequencies. The resonant frequency was interpreted as the oscillation between conditions favorable to formic acid decomposition (0 V) and conditions favorable to form CO2 (0.8 V).
The concept of implementing periodic illumination to improve the quantum yield of a typical photocatalytic reaction was first introduced in 1964 by Miller et al. In this work, they showed enhanced photosynthetic efficiency in the conversion of CO2 to O2 when the algal culture was exposed to periodic illumination in a Taylor vortex reactor. Sczechowski et al. later implemented the same approach for heterogeneous photocatalysis in 1993, where they demonstrated 5-fold increment in photoefficiency of formate decomposition by cycling between light and dark conditions with periods of 72 ms and 1.45 s respectively. They hypothesized that upon illumination of the catalyst, there is a critical illumination time during which absorbed photons generate oxidizing species (hvb+) on the surface of the catalyst. The generated species or their intermediates go on to react with substrates on the surface or in the bulk. During dark period, adsorption, desorption, and diffusion generally occurs in the absence of photons. After a critical recovery period in the dark, the photocatalyst can efficiently use photons again when photons are reintroduced. A summary of work involving “dynamic” photocatalysis was provided by Tokode et al. in 2016.
Dynamic promotion of methanol decomposition was demonstrated on 2 nm Pt nanoparticles using pulsed light. The rate acceleration to form H2 relative to static illumination was attributed to the selective weakening of adsorbed carbon monoxide, thereby also increasing the quantum efficiency of applied light.
In 2021, Sordello et al. experimentally demonstrated a 50% increase of the quantum yield for the Hydrogen Evolution Reaction (HER) over Pt/TiO2 nanoparticles via formic acid photoreforming under Controlled Period Illumination (CPI).
Implementation of catalyst dynamics has been proposed to occur by additional methods using oscillating light, electric potential, and physical perturbation.
References
Catalysis
Chemical kinetics
Chemical reactions
Chemical processes
Chemical reaction engineering
Reaction mechanisms
Physical organic chemistry | Catalytic resonance theory | [
"Chemistry",
"Engineering"
] | 3,248 | [
"Catalysis",
"Reaction mechanisms",
"Chemical reaction engineering",
"Chemical engineering",
"Chemical processes",
"nan",
"Physical organic chemistry",
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"Chemical kinetics"
] |
61,920,919 | https://en.wikipedia.org/wiki/Pseudoalgebra | In algebra, given a 2-monad T in a 2-category, a pseudoalgebra for T is a 2-category-version of algebra for T, that satisfies the laws up to coherent isomorphisms.
See also
Operad
Notes
References
Further reading
External links
https://ncatlab.org/nlab/show/pseudoalgebra+for+a+2-monad
https://golem.ph.utexas.edu/category/2014/06/codescent_objects_and_coherenc.html
Adjoint functors
Abstract algebra
Category theory | Pseudoalgebra | [
"Mathematics"
] | 132 | [
"Functions and mappings",
"Mathematical structures",
"Category theory stubs",
"Mathematical objects",
"Fields of abstract algebra",
"Mathematical relations",
"Category theory",
"Abstract algebra",
"Algebra"
] |
61,921,244 | https://en.wikipedia.org/wiki/Gigant%20%28manga%29 | Gigant (stylized in all caps) is a Japanese manga series written and illustrated by Hiroya Oku. It was serialized in Shogakukan's manga magazine Big Comic Superior from December 2017 to September 2021, with its chapters collected in ten volumes. The series follows pornographic actress Chiho "Papico" Johansson, who gains the ability to grow into a giant. With the support of aspiring film maker Rei Yokoyamada, she uses her power to protect Tokyo from attacking giants. In North America, the series is licensed in English by Seven Seas Entertainment, who has released the volumes in print since 2020.
Plot
Rei Yokoyamada, a teenager aspiring to become a film maker, learns that the pornographic actress Chiho "Papico" Johansson lives near him. Chiho is shunned by her family and neighbors because of her job, but develops a friendship with Rei. Chiho finds an injured old man wearing a helmet and underwear. When she tries to help him, he attaches a device to her wrist that does not come off, before transforming into a doll. Chiho discovers that the device lets her grow into a giant with incredible strength and durability, and shrink back to her regular size, though the growth only applies to her body, tearing her clothing and leaving her naked. Chiho's insecure and abusive boyfriend Ryuji returns home while she demonstrates her growth power for Rei, and assumes she is cheating on him; she uses her giant power to stop him from assaulting Rei, and Ryuji leaves, ending their relationship. Eventually, Chiho and Rei begin dating.
During this, a website called Enjoy the End becomes popular, where users can vote on proposed events, and the winners become reality regardless of how impossible they should be. These include a rain of excrement; a famous actor running naked through Shinjuku; the death of a celebrity rumored to be a murderer; and an earthquake. Following one request, a gigantic god of destruction descends on Tokyo, demolishing buildings and killing many. At the same time, another gigantic monster attacks New York, and is fought by a gigantic man. Rei's family takes refuge underground, and Chiho uses her giant power to fight and kill the god.
The police identify Chiho as the giant woman, and arrest her on suspicion of criminal insurrection. She faces execution, but is granted amnesty after more giants and three more gods appear, who she manages to kill. After it becomes known that Chiho, now a celebrity, is dating a highschool student, she loses entertainment industry opportunities and they decide to put their relationship on hold. Meanwhile, the United States drops a nuclear bomb on Honolulu to stop giants ravaging North America.
A group of time travelers from 2135, dressed like the old man and with similar growth powers, find Chiho, and tell her that two artificial intelligences, Socrates and Plato, were created in 2019 and leaked onto the internet, and, connecting to a Chinese satellite, built a gigantic facility in space from debris; using its machinery, including a bio-printer, the AIs operated Enjoy the End to understand humanity. By 2135, Socrates and Plato have drastically reduced the human population, which is why the group traveled to 2019 to destroy them.
Media
Manga
Gigant, written and illustrated by Hiroya Oku, was serialized in Shogakukan's manga magazine Big Comic Superior from December 8, 2017. to September 24, 2021. Shogakukan collected its chapters in ten volumes, released from May 30, 2018, to December 28, 2021.
In July 2019, Seven Seas Entertainment announced the license of the manga for English language release in March 2020.
Volumes
Related media
Shogakukan published a drawn gravure set featuring Chiho in a bikini in 2019, and a photo set featuring gravure model cosplaying in Chiho's t-shirt and a bikini in 2020.
Reception
The series has performed well commercially, with over one million volumes in circulation by July 2020. By December 2020, the manga had 1.2 million copies in circulation.
References
Further reading
External links
Fiction about size change
Science fiction anime and manga
Seinen manga
Seven Seas Entertainment titles
Shogakukan manga | Gigant (manga) | [
"Physics",
"Mathematics"
] | 862 | [
"Fiction about size change",
"Quantity",
"Physical quantities",
"Size"
] |
61,921,373 | https://en.wikipedia.org/wiki/C2H4OS | {{DISPLAYTITLE:C2H4OS}}
The molecular formula C2H4OS (molar mass: 76.11 g/mol, exact mass: 75.9983 u) may refer to:
Ethylene episulfoxide
Thioacetic acid | C2H4OS | [
"Chemistry"
] | 60 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,921,897 | https://en.wikipedia.org/wiki/Wake-equalising%20duct | A wake-equalising duct is a ship hull appendage mounted in the inflow region of a screw propeller intended to realign and adjust the velocity of the wake at the inflow to the propeller disc. Wake velocity may be straightened out, given contra-rotational swirl, accelerated, or a combination of these effects, all of which can improve propeller efficiency, giving either higher thrust or reducing power requirement for the same thrust.
Structure
The wake-equalising duct is a static flow modifier attached to the hull upstream of the propeller within the wake. It may be made of a single circular section duct directly ahead of the propeller, with fixed internal and/or external fins to impart rotational changes to the wake flow, or as two semicircular ducts mounted further forwards, one on each side of the hull, aligned to provide the desired flow modification. The duct(s) may be eccentrically mounted to include mainly the thickest part of the wake. This offset would usually be above the centre of the shaft.
Function
There are four components to the wake modification.
The wake is accelerated by the shape of the duct to be closer to the free-stream velocity of water over the rest of the propeller disc.
The direction of flow is aligned more closely with the free stream inflow.
A contra-rotational swirl may be induced, which will reduce outflow vorticity.
Flow separation at the afterbody may be reduced, which can reduce the thrust-deduction factor
These have the effect of increasing the efficiency of the propeller as it is working in a more uniform flow, and less energy is lost to hub vortex. The more uniform inflow conditions can also significantly reduce propeller blade vibration.
Fuel savings of up to 12% have been claimed. The system has the greatest benefit on hulls where the inflow conditions are inherently more disturbed.
Versions
The Becker Mewis Duct is a version based on an eccentric annular nozzle fitted between the hull and the propeller, supported by a number of flow directing radial vanes, each of which is angled to optimise inflow direction. The design is patented and has been in use since 2009.
The Schneekluth Wake Equalising Duct is a version using two semicircular nozzles, one on each side of the hull, centred above the shaft centreline, and angled to provide contra-rotational outflow swirl.
References
Naval architecture
Shipbuilding
Marine propulsion | Wake-equalising duct | [
"Engineering"
] | 492 | [
"Naval architecture",
"Marine propulsion",
"Shipbuilding",
"Marine engineering"
] |
61,922,068 | https://en.wikipedia.org/wiki/Unmanned%20store | An unmanned store is a retail concept in which there are no service personnel and no cashiers in the store. These stores can range from simple roadside stalls with a lockbox for payments to more sophisticated setups where transactions are handled through mobile applications and monitored by technology. Unlike an automated convenience store, the unmanned store concept may or may not rely on technology like smartphone-related systems and artificial intelligence to operate.
While the modern concept of unmanned stores has gained global attention, the idea of unmanned retail has existed in Japan for decades in the form of small, rural stalls known as Mujin Hanbai (無人販売). These traditional stalls, often found in rural areas, operate on an honor system where customers leave payment in a designated container.
History
Early examples
In January 2016, a 24-hour unmanned convenience store opened in Viken, Sweden. Customers use a smartphone app to enter the store, scan items, and receive a monthly bill. The store, designed to serve people needing essentials during off-hours, is monitored by security cameras, and the owner restocks the shelves.
Japan
In Japan, unmanned retail has a long tradition, particularly in the form of small, rural stalls called Mujin Hanbai. These stalls, often owned by local farmers, operate on an honor system where customers take products and leave payment in a designated container. This form of unmanned store is prevalent in rural areas and is known for its simplicity and reliance on community trust.
Other developments
Japan's Lawson announced in December 2017 that it would introduce unmanned stores that year. The Signature concept store in South Korea opened on May 16 on the 31st floor of Lotte World Tower, the tallest building in Seoul. On January 29, 2018, Taiwan also launched 7-11's first unmanned store X-STORE.
Description
Unmanned stores can take various forms. The simplest models are small stalls or roadside stands where customers leave payment in a lockbox or container based on the honor system. In more advanced models, unmanned stores may use technology such as artificial intelligence camera systems and machine algorithms to monitor customer movements and transactions. These stores may track which items customers pick up or return, automatically adding or removing them from a virtual shopping cart. In all cases, unmanned stores eliminate the need for staff, relying instead on customer honesty or technology to manage transactions.
See also
Automated retail
Automated convenience store
References
Retail formats | Unmanned store | [
"Technology"
] | 476 | [
"Information systems",
"Self-service"
] |
54,339,873 | https://en.wikipedia.org/wiki/The%20Space%20Observatory%20%28Observatoire%20de%20l%27Espace%29 | The Observatoire de l’Espace (Space Observatory) is a cultural laboratory created in 2000 by CNES (the French Space Agency) to promote a new vision of outer space, different from that of popular science. Space has a major influence on people's perceptions and imagination. The Observatoire de l’Espace introduces artists to the activities of the CNES and paves the way for any kind of space-inspired creations. Those creations strongly connected to space art are thereafter shared with the wider audience.
Programs
As a cultural laboratory, the Observatoire de l’Espace has a specific methodology: the goal is to share space-related items and innovations with artists, in order to inspire new creations. Two programmes have been developed following this process.
Cultural studies of Space Program
For many years, the Observatoire de l’Espace has been developing a cultural story of outer space by building an inventory of everything created on Earth about outer space. It resulted in a wide classification: space instruments (for example satellite prototypes), audio and video items (documentaries, video archives...), works of art inspired by outer space, laboratories and other space related buildings, and all kinds of everyday life objects.
The Observatoire de l’Espace is also welcoming researchers in human sciences and art history as well as building partnerships with research laboratories to foster works about Space in those fields.
An academic blog called Humanités spatiales (Space humanities) was also created in 2015. This website is dedicated to analysis and dialogue for researchers who are interested in space activities and its cultural representations. All this work can be used by artists as a basis for new creations.
The Spatial Creation and Imagination Program
The Observatoire de l’Espace fosters space-related artistic creation through its programme called "Création et Imaginaire spatial" (Spatial creation and imagination) which enables artists to benefit from an off-site residency. Various immersive ways to discover the space field are suggested to the artists: interviews with space experts, scientific data and documentation, access to places where spatial activities take place (laboratories, technical or industrial centers...), participation in scientists seminaries or even weightlessness flights aboard the Airbus Zero-G. Many creations arise from this programme: from literature to contemporary art and from performing arts to contemporary music. Many cultural events are organized by the Observatoire de l’Espace in order to present those creations but they are also displayed in many cultural places
.
Events
Sideration festival
The Sideration festival takes place every year in March at the CNES’ headquarters in Paris. Since 2011, it enables a deep immersion in Space and imagination through an eclectic programme: theatre, music, video, cinema, visual arts, readings and even real or fictional science stories. Every year, the CNES’ headquarters become a large art-science stage where about 30 artists have the opportunity to exhibit their space related productions. Those creations are often the result of a strong collaboration with the artists through the « off-site » residency programme, the sharing of studies about space or through calls for submissions regarding the journal Espace(s).
Nuit Blanche (All-nighter)
One opportunity for the Observatoire de l’Espace to organize an exhibition is for the Nuit Blanche which is an annual all night long, cultural, free arts festival. Since 2014, the Observatoire de l’Espace has called for artistic projects dealing with Space history. Selected archives are given to artists in order to widen their imagination or to be the core material of their creations. Archives and creations are both exhibited during the Nuit Blanche at the CNES’ headquarter.
The journal Espace(s)
The journal Espace(s) is an semi-annual journal dedicated to literature and a large variety of creations (typography, performing arts, comic strip, music, poetry...). It gathers texts dealing with a chosen theme linked with Space (Dreams, revolt, revolution, or Obsession and fascination). About thirty authors contribute to each issue. This collection is written under the format of laboratory books in order to mix up both literary and scientific universes. The works of the Spatial creation and imagination programme, made by the artists in residency, also have their place in the journal.
References
CNES
Space art | The Space Observatory (Observatoire de l'Espace) | [
"Astronomy"
] | 888 | [
"Space art",
"Outer space"
] |
54,341,339 | https://en.wikipedia.org/wiki/Andr%C3%A9%20Lagarrigue | André Lagarrigue (1924 – 14 January 1975) was a French particle physicist. Being the initiator of the Gargamelle experiment at CERN, his work was of paramount importance in the discovery of neutral currents — the first experimental indication of the existence of the Z0 boson. This major discovery was a step towards verification of the electroweak theory, today a pillar of the Standard Model.
Career and research
Born in Aurillac, France, André Lagarrigue was admitted to École Polytechnique in Paris in 1945, specializing in the field of weapons engineering. However, while still a student at École Polytechnique he was attracted to the field of experimental physics, and participated in an experiment designed to determine the mass of the muon using a cloud chamber. In 1952 he achieved a doctorate from the Sorbonne University on the experimental properties of muon decay. Between 1954 and 1955 he spent a sabbatical year at Berkeley, where he learnt of the experimental possibilities using particle accelerators such as the Bevatron. After his return to France and École Polytechnique, he turned his focus towards bubble chambers, becoming renowned for his work on heavy liquid bubble chambers in a time where most physicist worked with hydrogen bubble chambers. Hydrogen bubble chambers would provide a pure proton target and consequently better measurements. The heavy liquid bubble chambers would however be cheaper and provide a high density of the target, suitable for neutrino detection, since neutrinos have a very small cross-section.
Together with collaborators he constructed several heavy liquid bubble chambers at École Polytechnique. The first chamber built was called BP1, a propane bubble chamber of 1 liter. They first used scattering at small angles, from light coming from the back of the chamber. They then tried to use side illumination at 90°, like in a cloud chamber. This method turned out to be efficient, and was later used in the Gargamelle experiment. A second, bigger chamber, BP2, built for experiments at Saclay, contained 20 liters of a mixture of propane and methyl iodide. He went on to develop BP3.
After attending a conference in 1963, on the newest developments in the field of neutrino physics, Lagarrigue came up with the idea to construct a heavy liquid chamber for detection of neutrinos — an idea that would earn him the nickname father of Gargamelle. He wrote the first published proposal for Gargamelle, dated 10 February 1964, and gathered a collaboration consisting of seven laboratories: École Polytechnique Paris, RWTH Aachen, ULB Bruxelles, Istituto di Fisica dell'Università di Milano, LAL Orsay, University College London and CERN. During the next years he led the collaboration to many important discoveries, amongst others that of the neutral currents in both leptonic and hadronic events, and the experimental proof of the fractional charges of the quarks. Gargamelle turned out to be one of the most significant experiments in the history of CERN.
In 1964 he became professor at the University of Orsay. In 1969 he became director of Orsay Linear Accelerator Laboratory, a position he held until his untimely death in 1975. Lagarrigue died of a heart attack, while leaving one of his courses at the University of Orsay.
Awards and honors
In 1975 Lagarrigue was the second recipient of the Prize Ampère, awarded annually by the French Academy of Science.
A prize named in Lagarrigue's honor, The André Lagarrigue Prize, issued by the French Physics Society on the occasion of the 50th jubilee of Orsay Linear Accelerator Laboratory, is awarded annually to a senior experimental physicist working in France.
An auditorium at École Polytechnique in Paris is named in his honor.
Lagarrigue has a street named after him at CERN, in the Prévessin site, and a square in the Meyrin site
References
Further reading
List of publications by André Lagarrigue, INSPIRE
Memorial lectures for André Lagarrigue, Paris March 1975
Morellet, Daniel, "Lagarrigue André - (1924-1925)", Encyclopædia Universalis (in French)
1924 births
1975 deaths
People associated with CERN
Experimental physicists
French physicists
Particle physicists
Members of the French Academy of Sciences
École Polytechnique alumni
University of Paris alumni | André Lagarrigue | [
"Physics"
] | 901 | [
"Particle physicists",
"Particle physics"
] |
54,342,619 | https://en.wikipedia.org/wiki/Central%20Basin%20Spreading%20Center | Central Basin Spreading Center (CBSC), formerly Central Basin Fault, is a seafloor spreading center of the West Philippine Basin. It is a long, NW-SE-trending structure that is considered to have been the spreading center of the West Philippine Basin (WPB) from the Eocene to the middle Oligocene. It is a remnant spreading center, meaning that it is no longer active. However, it still displays many of the features that are characteristic of spreading centers, such as a rift valley, axial ridges, and abyssal hills. The CBSC is divided into two segments: the eastern segment and the western segment. The eastern segment is characterized by slow-spreading features, such as a deep rift valley and nodal basins. The western segment is characterized by fast-spreading features, such as overlapping spreading centers and volcanic axial ridges.
The CBSC is also associated with a number of other features, including oceanic plateaus and seamount chains. These features suggest that the CBSC formed in a complex tectonic environment, possibly involving a mantle plume. The study of the CBSC provides important insights into the formation and evolution of marginal basins. Marginal basins are small ocean basins that are formed on the margins of continents or island arcs. The CBSC is a good example of a marginal basin that formed through seafloor spreading.
References
Oceanography | Central Basin Spreading Center | [
"Physics",
"Environmental_science"
] | 278 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics"
] |
54,344,129 | https://en.wikipedia.org/wiki/NGC%207032 | NGC 7032 is a spiral galaxy located about 140 million light-years away in the constellation Pavo. It has an estimated diameter of 71,370 light-years. NGC 7032 was discovered by astronomer John Herschel on July 20, 1835.
See also
NGC 5055
List of NGC objects (7001–7840)
References
External links
Unbarred spiral galaxies
Pavo (constellation)
7032
66427
Astronomical objects discovered in 1835 | NGC 7032 | [
"Astronomy"
] | 91 | [
"Constellations",
"Pavo (constellation)"
] |
54,344,374 | https://en.wikipedia.org/wiki/Trithiapentalene | Trithiapentalene is an organic bicyclic molecule containing two sulfur heterocycles. Its 10-π aromatic structure is similar to naphthalene. There has been a literature dispute about whether the connectivity among the three sulfur atoms is a case of rapid tautomerization between two valence tautomers or a 3-center 4-electron bond.
The reactions have been little studied. It forms a dinickel complex upon reaction with bis(allyl)nickel.
See also
Dithiolium salt
References
Sulfur heterocycles
Aromatic compounds
Heterocyclic compounds with 2 rings | Trithiapentalene | [
"Chemistry"
] | 125 | [
"Organic compounds",
"Aromatic compounds"
] |
54,344,382 | https://en.wikipedia.org/wiki/Comparison%20of%20Samsung%20Galaxy%20S%20smartphones | The following is a comparative list of smartphones belonging to smartphones in the Samsung Galaxy S series line of devices, using the Android operating system. This table is primarily intended to show the differences between the model families of phones in the Galaxy S series. The list only covers unlocked and international devices.
Galaxy S
Galaxy S2
Galaxy S3
Galaxy S4
Galaxy S5
Galaxy S6
Galaxy S7
Galaxy S8
Galaxy S9
Galaxy S10
Galaxy S20
Galaxy S21
Galaxy S22
Galaxy S23
Galaxy S24
References for comparison table
See also
Comparison of Samsung Galaxy Note smartphones
Comparison of smartphones
References
Galaxy S Series
S Series
Android (operating system) devices
Samsung Galaxy S
Samsung Galaxy S smartphones | Comparison of Samsung Galaxy S smartphones | [
"Technology"
] | 142 | [
"Computing comparisons"
] |
54,344,475 | https://en.wikipedia.org/wiki/Econom%C3%ADa%20Feminista | Economía Feminista, in English: Feminist Economics, is an Argentine digital media, focused on disclosure and creation of economics information about the gender gap. The media is managed by Mercedes D`Alessandro, Magalí Brosio, Violeta Guitart and Agurtzane Urrutia.
Concept
Economía Femini(s)ta, is a portmanteau of feminista and minita. It attempts to end stereotypes about women. It was created in 2015 and its goal is to be a source of economic data to help to display economic differences by gender, especially in Argentina.
Awards
Economía Feminista was awarded the Lola Mora prize in 2016 for the best digital media by Dirección General de la Mujer, promoted by Buenos Aires city's Legislature.
Sources
Digital media
Feminist blogs | Economía Feminista | [
"Technology"
] | 165 | [
"Multimedia",
"Digital media"
] |
54,344,713 | https://en.wikipedia.org/wiki/National%20Philanthropy%20Day | National Philanthropy Day is an annual observance on November 15 that is designated by the Association of Fundraising Professionals (AFP) to celebrate charitable activities in the form of donated financial, in-kind, and volunteering support.
It is celebrated with blog postings by AFP that highlight outstanding charitable activities, as well as luncheons and awards throughout the United States, as well as other places in North and South America, by different AFP chapters.
History
The Association of Fundraising Professionals' (AFP) National Philanthropy Day was created in 1986 by philanthropist Douglas Freeman of Orange County, California, and formalized by then-U.S. President Ronald Reagan, who signed a proclamation recognizing November 15 as National Philanthropy Day in the US.
In 2012, the Government of Canada signed the National Philanthropy Day Act into law, declaring November 15 as the annual celebration of National Philanthropy Day as well.
Overview
National Philanthropy Day is registered with the United States Patent and Trademark Office and the U.S. Department of Commerce. The official National Philanthropy Day song, "Now More Than Ever," was written by Marvin Hamlisch. The day has been celebrated by AFP chapters across the US, including San Diego, California, Toledo, Ohio, Chattanooga, Tennessee, and Detroit, Michigan.
See also
Association for Leaders in Volunteer Engagement
Association for Volunteer Administration
Global Youth Service Day
Good Deeds Day
International Council of Voluntary Agencies
International Volunteer Day
International Year of Volunteers
Join Hands Day
List of awards for volunteerism and community service
Make A Difference Day
Mandela Day
MLK Day of service
Mitzvah Day
National Public Lands Day (USA)
NetDay
Random Acts of Kindness Day
September 11 National Day of Service (9/11 Day)
Sewa Day
World Kindness Day
References
External links
Official Website
November observances
Philanthropy
Observances in the United States
Observances in Canada
Philanthropy in the United States
Philanthropy in Canada | National Philanthropy Day | [
"Biology"
] | 378 | [
"Philanthropy",
"Behavior",
"Altruism"
] |
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