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|---|---|---|---|---|---|---|
68,681,251 | https://en.wikipedia.org/wiki/Phosphide%20carbide | Phosphide carbides or carbide phosphides are compounds containing anions composed of carbide (C4−) and phosphide (P3−). They can be considered as mixed anion compounds. Related compounds include phosphide silicides, germanide phosphides, arsenide carbides, nitride carbides and silicide carbides.
In light rare earth phosphide carbides, the ethenide ion [C=C]4− exists. In these P and C2 are disordered, and they randomly substitute for each other, even though charge differs. Bonds between carbon and phosphorus are weak, and so these kinds of compounds do not contain a C-P bond, instead carbon or phosphorus stand by themselves.
Phosphide carbides can be made by heating a metal, red phosphorus and graphite powder together in a carbon crucible under an inert gas atmosphere.
List
References
Phosphides
Carbides
Mixed anion compounds | Phosphide carbide | [
"Physics",
"Chemistry"
] | 218 | [
"Ions",
"Matter",
"Mixed anion compounds"
] |
57,721,191 | https://en.wikipedia.org/wiki/Ecological%20Psychology%20%28journal%29 | Ecological Psychology is a quarterly peer-reviewed academic journal covering ecological psychology. It was established in 1989 and is published by Taylor & Francis. It is the official journal of the International Society for Ecological Psychology. The editor-in-chief since 2020 has been is Michael J. Richardson (Macquarie University, Sydney, Australia). According to the Journal Citation Reports, the journal has a current 5-year impact factor of 2.4, with a 5 year ranking average of 62 out of 152 journals in the category "Psychology, Experimental". Its major focus is on problems of perception, action, cognition, communication, learning, development, behavioural dynamics, and evolution in all species, to the extent that those problems are related to whole animal-environment systems. Human experimental psychology, developmental/social psychology, animal behavior, human factors, fine arts, communication, computer science, philosophy, physical education and therapy, speech, etc., can be considered as significant contributors.
References
External links
Ecology journals
Experimental psychology journals
Taylor & Francis academic journals
Quarterly journals
Academic journals established in 1989
English-language journals | Ecological Psychology (journal) | [
"Environmental_science"
] | 219 | [
"Environmental science journals",
"Ecology journals"
] |
57,721,868 | https://en.wikipedia.org/wiki/Mass-flux%20fraction | The mass-flux fraction (or Hirschfelder-Curtiss variable or Kármán-Penner variable) is the ratio of mass-flux of a particular chemical species to the total mass flux of a gaseous mixture. It includes both the convectional mass flux and the diffusional mass flux. It was introduced by Joseph O. Hirschfelder and Charles F. Curtiss in 1948 and later by Theodore von Kármán and Sol Penner in 1954. The mass-flux fraction of a species i is defined as
where
is the mass fraction
is the mass average velocity of the gaseous mixture
is the average velocity with which the species i diffuse relative to
is the density of species i
is the gas density.
It satisfies the identity
,
similar to the mass fraction, but the mass-flux fraction can take both positive and negative values. This variable is used in steady, one-dimensional combustion problems in place of the mass fraction. For one-dimensional ( direction) steady flows, the conservation equation for the mass-flux fraction reduces to
,
where is the mass production rate of species i.
References
Chemical properties
Dimensionless numbers of chemistry
Combustion | Mass-flux fraction | [
"Chemistry"
] | 229 | [
"Combustion",
"Dimensionless numbers of chemistry",
"nan"
] |
57,723,155 | https://en.wikipedia.org/wiki/NGC%201273 | NGC 1273 is a lenticular galaxy located about 245 million light-years away in the constellation Perseus. It was discovered by astronomer Heinrich d'Arrest on February 14, 1863 and is a member of the Perseus Cluster.
See also
List of NGC objects (1001–2000)
References
External links
Perseus Cluster
Perseus (constellation)
Lenticular galaxies
1273
12396
Astronomical objects discovered in 1863 | NGC 1273 | [
"Astronomy"
] | 88 | [
"Perseus (constellation)",
"Constellations"
] |
57,723,249 | https://en.wikipedia.org/wiki/List%20of%20engineering%20physics%20schools | Engineering physics (or engineering science) can be studied at the bachelors, masters and Ph.D. levels at many universities, typically offered in a partnership between engineering faculties and the departments of physics.
Canada
In Canada, the Canadian Engineering Accreditation Board is responsible for accrediting undergraduate engineering physics programs, graduate study in aerospace engineering is also available at several Canadian post-secondary institutions, though Canadian post-graduate engineering programs do not require accreditation.
University of Alberta - Engineering Physics
University of British Columbia - Engineering Physics
Carleton University - Engineering Physics
Dalhousie University - Engineering Physics
McMaster University - Engineering Physics
Queen's University - Engineering Physics
Royal Military College of Canada - Engineering Physics
University of Saskatchewan - Engineering Physics
Simon Fraser University - Engineering Science
University of Toronto - Engineering Science
Only undergraduate engineering programs in Canada are accredited, and this is done by the Canadian Engineering Accreditation Board.
References
Engineering education
Lists of engineering schools | List of engineering physics schools | [
"Engineering"
] | 182 | [
"Lists of engineering schools",
"Engineering universities and colleges"
] |
57,724,562 | https://en.wikipedia.org/wiki/Universal%20dielectric%20response | In physics and electrical engineering, the universal dielectric response, or UDR, refers to the observed emergent behaviour of the dielectric properties exhibited by diverse solid state systems. In particular this widely observed response involves power law scaling of dielectric properties with frequency under conditions of alternating current, AC. First defined in a landmark article by A. K. Jonscher in Nature published in 1977, the origins of the UDR were attributed to the dominance of many-body interactions in systems, and their analogous RC network equivalence.
The universal dielectric response manifests in the variation of AC Conductivity with frequency and is most often observed in complex systems consisting of multiple phases of similar or dissimilar materials. Such systems, which can be called heterogenous or composite materials, can be described from a dielectric perspective as a large network consisting of resistor and capacitor elements, known also as an RC network. At low and high frequencies, the dielectric response of heterogeneous materials is governed by percolation pathways. If a heterogeneous material is represented by a network in which more than 50% of the elements are capacitors, percolation through capacitor elements will occur. This percolation results in conductivity at high and low frequencies that is directly proportional to frequency. Conversely, if the fraction of capacitor elements in the representative RC network (Pc) is lower than 0.5, dielectric behavior at low and high frequency regimes is independent of frequency. At intermediate frequencies, a very broad range of heterogeneous materials show a well-defined emergent region, in which power law correlation of admittance to frequency is observed. The power law emergent region is the key feature of the UDR. In materials or systems exhibiting UDR, the overall dielectric response from high to low frequencies is symmetrical, being centered at the middle point of the emergent region, which occurs in equivalent RC networks at a frequency of :. In the power law emergent region, the admittance of the overall system follows the general power law proportionality , where the power law exponent α can be approximated to the fraction of capacitors in the equivalent RC network of the system α≅Pc.
Significance of the UDR
The power law scaling of dielectric properties with frequency is valuable in interpreting impedance spectroscopy data towards the characterisation of responses in emerging ferroelectric and multiferroic materials.
References
Dielectrics
Electric and magnetic fields in matter
Condensed matter physics
Electrical engineering
Electronic engineering | Universal dielectric response | [
"Physics",
"Chemistry",
"Materials_science",
"Technology",
"Engineering"
] | 524 | [
"Computer engineering",
"Phases of matter",
"Electric and magnetic fields in matter",
"Materials science",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Electrical engineering",
"Dielectrics",
"Matter"
] |
57,725,002 | https://en.wikipedia.org/wiki/ISO%209060 | ISO 9060, Specification and classification of instruments for measuring hemispherical solar and direct solar radiation, is an ISO standard for the classification of pyranometers and pyrheliometers.
References
09060
Meteorological instrumentation and equipment | ISO 9060 | [
"Technology",
"Engineering"
] | 52 | [
"Meteorological instrumentation and equipment",
"Measuring instruments"
] |
57,726,145 | https://en.wikipedia.org/wiki/IDPN%20%28chemical%29 | IDPN (3,3'-iminodipropanenitrile) is a neurotoxin with ototoxic and hepatotoxic effects. It causes irreversible movement disorder.
Ototoxicity
IDPN has been shown to kill vestibular hair cells, disrupting normal vestibular function, in rats, mice, guinea pigs, and frogs. In rodents, the loss of vestibular function results in balance-related deficits, including circling behavior, retropulsion, and head bobbing, as well as weight loss. Type I hair cells are more sensitive to IDPN toxicity than Type II hair cells. No regeneration of vestibular hair cells was observed, thus these effects can be considered to be irreversible.
IDPN has also been shown to kill cochlear hair cells, affecting auditory function. IDPN-induced hearing loss covered a broad range of frequencies.
References
Neurotoxins
Amines
Nitriles
Hepatotoxins | IDPN (chemical) | [
"Chemistry"
] | 217 | [
"Functional groups",
"Neurotoxins",
"Amines",
"Neurochemistry",
"Nitriles",
"Bases (chemistry)"
] |
57,726,150 | https://en.wikipedia.org/wiki/C9H12O | {{DISPLAYTITLE:C9H12O}}
The molecular formula C9H12O (molar mass: 136.19 g/mol, exact mass: 136.0888 u) may refer to:
Mesitol (2,4,6-trimethylphenol)
2-Phenyl-2-propanol
2,3,6-Trimethylphenol
Molecular formulas | C9H12O | [
"Physics",
"Chemistry"
] | 92 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
57,726,342 | https://en.wikipedia.org/wiki/McArthur%20Lake%20Wildlife%20Corridor | The McArthur Lake Wildlife Corridor (MLWC) is a wildlife corridor in northern Idaho, United States.
It links the wilderness areas of the Selkirk and Cabinet mountains, and is used by species such as grizzly bears that move between these areas. It also provides a wintering area for deer and other ungulates. A highway and two railway lines run through the corridor, with a strip of side roads, buildings and fences along the highway. The highway section running through the corridor has high rates of vehicle collisions with wildlife. There is limited opportunity for creating safe wildlife crossings due to the difficult terrain. Conservation groups have been active in obtaining easements on timber land to prevent further development in the corridor while allowing sustainable forestry.
Location
The McArthur Lake Wildlife Corridor forms a route between the Selkirk and Cabinet mountains, and is used by species such as grizzly bear, elk and wolverine to reach the Idaho Panhandle and the Kootenai National Forest.
The corridor connects the Selkirk and Cabinet-Yaak grizzly bear recovery zones.
It takes its name from McArthur Lake, which lies in the center of the corridor.
Highway 2/95 from Sandpoint to Bonners Ferry runs through the corridor.
The corridor is also crossed by the Union Pacific Railroad and the Burlington Northern Santa Fe Railway.
The corridor's concentration area extends along the highway for approximately .
Development for about on each side of the highway includes buildings, fences, roads and driveways.
The many access roads along this stretch of the highway make fencing difficult.
Environment
McArthur Lake Wildlife Corridor is in a scenic area of Idaho.
It contains conifer forests, forested or shrub wetlands and swamps, streams and rivers.
The high-quality cold water streams are home to the only populations of interior redband trout known in Idaho, and are key to recovery of the threatened bull trout.
Animals that migrate through the corridor include American black bear (Ursus americanus), Canada lynx (Lynx canadensis), elk (Cervus canadensis), gray wolf (Canis lupus), grizzly bear (Ursus arctos horribilis), moose (Alces americanus), white-tailed deer (Odocoileus virginianus) and wolverine (Gulo gulo).
The corridor supports six species that are federally listed or candidates to be considered threatened or endangered, and many others that are rare and sensitive.
As well as being a linkage area between the Selkirk and Cabinet Mountains the MLWC provides a winter range for moose and white-tailed deer.
In the spring and early summer it is a natal area for several species of ungulate, who are at risk as they move around and cross the highway.
In the summer it is more important for grizzlies.
In fall and winter it is a residence area for ungulates.
The corridor is known as an excellent area for hunting and fishing.
Hunters target elk, mule deer, moose, white-tailed deer, black bear, mountain lion, waterfowl and upland game birds.
The public also uses the corridor for hiking and berry picking.
Vehicle collisions
The area has the greatest number of collisions with wildlife in Idaho.
The animals move down to lower land in the winter, taking them to the Highway 95 area, called the "McArthur Killing Fields" by an employee of the Idaho Department of Transportation.
In the winter of 1996 northern Idaho received an exceptional of snow, which forced deer, elk and moose to move down to the area around Route 95.
The animals could easily cross the snow banks, but became confused and vulnerable on the icy highway.
At least 200 deer were killed by collisions with cars that winter, as well as a few moose and elk.
As of 2009 about 6,600 vehicles crossed the wildlife corridor daily on the highway.
It was the top place for wildlife collisions in the state, with 34 collisions in 2007.
Animals other than birds killed by vehicles are, in order of frequency, white-tailed deer, turtles, otter, moose, elk and wolverine.
At one stage there was funding for an underpass in the concentration area of the corridor, but for various reasons this was lost.
When the culvert at the McArthur Lake Dam on Deep Creek is replaced by a bridge, that would be used to provide a passageway for wildlife.
To the south of the culvert the topography and high water table make it difficult to install structures for wildlife crossings.
The National Fish and Wildlife Foundation (NFWF) under its Cabinet Yaak Wildlife Corridors program has given funding to The Nature Conservancy to provide safer passage of people and wildlife in the corridor.
In January 2012 the NWFW granted $99,268 towards the McArthur Lake Wildlife Safety Project, which would attempt to reduce collisions between wildlife and vehicles on Highway 95 near Bonners Ferry.
The Nature Conservancy was to match the Foundation funds, and to work with the Kootenai Valley Resource Initiative to implement the improvements, which would be selected based on cost-benefit analysis.
These could include wildlife fencing and systems to detect animals and alert motorists.
Protection efforts
In December 2010 it was reported that Walmart had donated $1 million to The Nature Conservancy to protect two recovery zones for grizzly bears and habitat for over twenty species of high conservation need in the McArthur Lake Wildlife Corridor.
On 11 July 2013 The U.S. Forest Service announced a $4.1 million award to acquire a conservation easement from Stimson Lumber Company within and adjoining the McArthur Lake Wildlife Corridor.
The checkerboard forest property was the largest single property in the MLWC to remain unprotected.
In September 2016 about of forest to the east of McArthur Lake between Sandpoint and Bonners Ferry was placed under conservation easements, which compensate landowners for limiting uses such as development and subdivision, but allow sustainable forestry to continue.
They would benefit wildlife, help local economies, improve water quality and support recreation.
Funding was by Forest Legacy Funds, which come from the Land and Water Conservation Fund.
This receives royalties from energy companies in return for permission to drill for oil and gas on the Outer Continental Shelf.
The Idaho Department of Lands (IDL) obtained the easements through partnership between the Molpus Woodlands Group, the Idaho Department of Fish and Game, The Nature Conservancy and the United States Forest Service.
In April 2018 it was announced that of forest near Bonners Ferry would be placed under conservation easements.
Half of the land was near Hall Mountain and half was in the McArthur Lake Wildlife Corridor east of McArthur Lake.
Public access for hunting, hiking and berry picking would still be allowed.
Notes
Sources
Ecological connectivity
Conservation projects in the United States
Animal migration | McArthur Lake Wildlife Corridor | [
"Biology"
] | 1,375 | [
"Ethology",
"Behavior",
"Animal migration"
] |
57,726,601 | https://en.wikipedia.org/wiki/Comparison%20matrix | In linear algebra, let be a complex matrix. The comparison matrix of complex matrix A is defined as
See also
Hurwitz-stable matrix
P-matrix
Perron–Frobenius theorem
Z-matrix
L-matrix
M-matrix
H-matrix (iterative method)
References
Matrices | Comparison matrix | [
"Mathematics"
] | 59 | [
"Matrices (mathematics)",
"Mathematical objects",
"Matrix stubs"
] |
57,726,619 | https://en.wikipedia.org/wiki/H-matrix%20%28iterative%20method%29 | In mathematics, an H-matrix is a matrix whose comparison matrix is an M-matrix. It is useful in iterative methods.
Definition: Let be a complex matrix. Then comparison matrix M(A) of complex matrix A is defined as where for all and for all . If M(A) is a M-matrix, A is a H-matrix.
Invertible H-matrix guarantees convergence of Gauss–Seidel iterative methods.
See also
Hurwitz-stable matrix
P-matrix
Perron–Frobenius theorem
Z-matrix
L-matrix
M-matrix
Comparison matrix
References
Matrices | H-matrix (iterative method) | [
"Mathematics"
] | 126 | [
"Matrices (mathematics)",
"Mathematical objects",
"Matrix stubs"
] |
57,726,900 | https://en.wikipedia.org/wiki/NGC%201274 | NGC 1274 is a compact elliptical galaxy located about 280 million light-years away in the constellation Perseus. NGC 1274 was discovered by astronomer Lawrence Parsons on December 4, 1875. It is a member of the Perseus Cluster.
See also
List of NGC objects (1001–2000)
References
External links
Perseus Cluster
Perseus (constellation)
Elliptical galaxies
1274
12413
Astronomical objects discovered in 1875
Discoveries by Lawrence Parsons | NGC 1274 | [
"Astronomy"
] | 91 | [
"Perseus (constellation)",
"Constellations"
] |
57,727,010 | https://en.wikipedia.org/wiki/David%20Silver%20%28roboticist%29 | David Silver was a student at MIT in the early 1970s, who was the primary developer of the Silver Arm, an improved robotic arm which was used for experimenting in mechanisms for fine motor control using motions similar to human hand and finger movements.
While still a high school student, prior to enrolling at MIT, Silver had frequented the Project MAC offices, and was taught to program in PDP-6 assembly language by some of the early hackers, who picked him up as a 'mascot' of their group. According to Steven Levy's book Hackers: Heroes of the Computer Revolution, his presence at the lab, and his being allowed to work on independent robotics projects, became a source of friction between the nascent Hacker group and the project's administrators.
See also
L. Peter Deutsch, another early MIT hacker who began with the Project MAC group's computers as a teen before enrolling at MIT, and who went on to develop several important software systems such as Ghostscript
Tom Knight, who would also join the MIT hackers while still underage, and went on to be a significant figure in the subsequent Lisp Machine projects.
References
Year of birth missing (living people)
Living people
American computer scientists
21st-century American engineers
American roboticists | David Silver (roboticist) | [
"Technology"
] | 255 | [
"Computing stubs",
"Computer specialist stubs"
] |
57,731,049 | https://en.wikipedia.org/wiki/Estriol%20dipropionate | Estriol dipropionate, or estriol 3,17β-dipropionate, is a synthetic estrogen and estrogen ester – specifically, the C3 and C17β dipropionate ester of estriol – which was first described in 1963 and was never marketed. Following a single intramuscular injection of 6.94 mg estriol dipropionate (equivalent to 5.0 mg estriol) in an oil solution, peak levels of estriol occurred after 0.83 days, an elimination half-life of 12.7 hours was observed, and estriol levels remained elevated for up to 4 days. For comparison, the duration of estriol was much shorter, while that of estriol dihexanoate was much longer.
See also
List of estrogen esters § Estriol esters
References
Abandoned drugs
Estriol esters
Propionate esters
Synthetic estrogens | Estriol dipropionate | [
"Chemistry"
] | 199 | [
"Drug safety",
"Abandoned drugs"
] |
57,731,093 | https://en.wikipedia.org/wiki/Estriol%20dihexanoate | Estriol dihexanoate, or estriol 3,17β-dihexanoate, is a synthetic estrogen and estrogen ester – specifically, the C3 and C17β dihexanoate ester of estriol – which was first described in 1963 and was never marketed. Following a single intramuscular injection of 8.90 mg estriol dihexanoate (equivalent to 5.0 mg estriol) in an oil solution, peak levels of estriol occurred after 2.1 to 3.4 days, an elimination half-life of 187 to 221 hours was observed, and estriol levels remained elevated for up to 20 to 50 days. For comparison, the durations of estriol and estriol dipropionate were far shorter.
See also
List of estrogen esters § Estriol esters
References
Abandoned drugs
Caproate esters
Estriol esters
Synthetic estrogens
Secondary alcohols | Estriol dihexanoate | [
"Chemistry"
] | 206 | [
"Drug safety",
"Abandoned drugs"
] |
57,731,238 | https://en.wikipedia.org/wiki/Estrone%20benzoate | Estrone benzoate, or estrone 3-benzoate, is a synthetic estrogen and estrogen ester – specifically, the C3 benzoate ester of estrone – which was first reported in 1932 and was never marketed. It led to the development in 1933 of the more active estradiol benzoate, the first estradiol ester to be introduced for medical use.
See also
List of estrogen esters § Estrone esters
References
Abandoned drugs
Benzoate esters
Estrone esters
Ketones
Sex hormone esters and conjugates
Synthetic estrogens | Estrone benzoate | [
"Chemistry"
] | 125 | [
"Ketones",
"Functional groups",
"Drug safety",
"Abandoned drugs"
] |
57,731,480 | https://en.wikipedia.org/wiki/Ethinylestradiol%20benzoate | Ethinylestradiol benzoate, or 17α-ethynylestradiol 3-benzoate, is a synthetic estrogen and estrogen ester – specifically, the C3 benzoate ester of ethinylestradiol – which was first described in the late 1930s and was never marketed.
See also
List of estrogen esters § Esters of other steroidal estrogens
References
Abandoned drugs
Ethynyl compounds
Benzoate esters
Tertiary alcohols
Estranes
Estrogen esters
Sex hormone esters and conjugates
Synthetic estrogens | Ethinylestradiol benzoate | [
"Chemistry"
] | 126 | [
"Drug safety",
"Abandoned drugs"
] |
57,731,485 | https://en.wikipedia.org/wiki/Spyce%20Kitchen | Spyce Kitchen or just Spyce was a robotic-powered restaurant which prepares food in "three minutes or less".
History
MIT mechanical engineering graduates Michael Farid, Brady Knight, Luke Schlueter and Kale Rogers developed the kitchen using seven autonomous work stations to prepare bowl-based meals using healthy ingredients such as kale, beans and grains. The four graduates wanted to make healthy meals more affordable, so they built the robotic technology and initially served the food to students at an MIT dining hall. The group received the $10,000 "Eat It" Lemelson-MIT undergraduate prize in 2016 as one of America's top two collegiate inventors in food technology.
The four then teamed up with chef Daniel Boulud to create the new menu for their restaurant. Prices started at $7.50 for an entire meal in a bowl at their first real branch, which opened on May 3, 2018, in Boston, Massachusetts. Referred to as the "Spyce Boys", the four founders were inspired by their experiences as hungry student athletes on tight budgets. Spyce Kitchen automated cooking units also clean up after cooking and dirtying the cooking apparatus.
Funding
Spyce raised $21 million in series A funding in September 2018, led by venture capital firms Maveron, Collaborative Fund, and Khosla Ventures.
Restaurants
Spyce operated and then shuttered two restaurants in the Greater Boston area. Their first restaurant was located at 241 Washington St in downtown Boston. Their second restaurant, which opened in February 2021, was located at 1 Brattle Square, in Harvard Square.
Acquisition by Sweetgreen and closure
In 2021, the company was acquired by Sweetgreen, a chain of salad restaurants.
Both Spyce restaurants were closed following the Sweetgreen acquisition, "to focus on developing technology for Sweetgreen restaurants". The downtown Boston location closed October 22, 2021, and the Harvard Square location closed February 18, 2022.
References
External links
Robotics
Robotic restaurants | Spyce Kitchen | [
"Engineering"
] | 399 | [
"Robotic restaurants",
"Robotics",
"Automation"
] |
57,731,730 | https://en.wikipedia.org/wiki/Ecological%20unit | Ecological units refer to specific levels or degrees of organization within ecological systems. The units that are most commonly used and discussed within ecological systems are those at the levels of individuals, populations, communities, and ecosystems. These terms help distinguish between very specific, localized interactions, such as those occurring at the individual or population level, and broader, more complex interactions that occur at the community and ecosystem levels, providing a framework for understanding ecological structure and processes at different scales.
These ecological units are foundational to the field of ecology as they define and identify the key components and relationships within ecological systems at the different levels—providing cohesion in conversation and research. Additionally, these terms and the concept of ecological units as a whole are intertwined in ecological theory, understanding biodiversity, conservation strategies, and more. However, these ecological units have been met with some disagreements over the inconsistencies in the exact terminology and its uses. Arguments over stem from conflicting views from four different areas:
Whether the units are defined statistically or via a network of interactions: Statistical definitions would mean that the ecological units are measured using measurable parameters, based on statistical values and criteria. A network of interactions entails that ecological units are defined by the relationships and dynamics between the organisms and environment.
Whether boundaries are drawn by topographical or process-related criteria: Topographical criteria means that the ecological boundaries are based on the physical and geographical features in the surroundings. Process-related criteria would focus on the ecological processes and interactions that occur at the level.
How high the required internal relationships are: This refers to the degree of intensity and complexity of the interactions and interconnectedness of the ecological unit.
Whether the ecological unit is perceived as a "real" entity or an abstraction by an observer: This argument debates if an ecological unit, despite having a name and loose definition, whether it is simply a measure for conceptual thought that helps in modeling, or whether it is definitive and seen as a concrete thing.
Summary
Individual
The most basic ecological unit is at the individual level. At this level, singular organisms in a single species are the focus of reference. Studying individuals can help reinforce concepts in their physiology and behavior. Additionally, single individuals can be outliers in many ways, such as genetic variation, which can lead to questions about what triggered this change and to see whether it spreads to the remainder of the population. It can be argued that studying individuals is insignificant and no concrete conclusions can be drawn about entire populations based on one individual. Regardless of this remark, individuals can still provide valuable insights into the broader dynamics of a species, as they offer a starting point for understanding the underlying processes of adaptation, survival, and reproduction.
Population
The next level is populations—this refers to all individuals in a single species. Studying populations is crucial for understanding interactions within a species, between species, and with the surrounding environment. It can also reveal similarities and differences between the same species in the same location or in different locations, helping to identify key variables that influence these variations. Changes within populations can often be attributed to some sort of survival pressure that is urging an evolutionary adaptation in order for the species to maintain itself. These pressures may include competition for resources, predation, climate changes, or disease outbreaks. By examining population dynamics, scientists can gain insights into how species adapt over time, predict future changes, and make informed decisions about conservation efforts or managing ecosystems.
Community
Community would follow population in terms of hierarchical largeness. Community would be the collective dynamics amongst species and the habitat in which they live in. Communities are most closely associated with habitats, which are more intimate than compared to ecosystems. Habitats signify a smaller, more specific region, while an ecosystem is a broader term that can encompass multiple habitats. An example of this could be that of the marine ecosystem which can be an umbrella term for all organisms living in oceanic conditions. However, a habitat in the Gulf of Maine varies widely that the one of the Great Barrier Reef, despite both of them falling under the marine ecosystem term. This also means that the communities, the organisms that exist in these two different habitats, also differ.
Ecosystems
The last ecological unit is ecosystems. Ecosystems encompass the diverse and complex conditions of the Earth, including both biotic and abiotic components. They often differ in geographic locations with respect to their position relative to the equator, relationship to altitude in which the location resides, seasonal trends, etc. Some examples of ecosystems include marine/aquatic ecosystems, rainforests, tundras, savannas, etc. As mentioned above, not all habitats or communities within the same ecosystem are exactly the same, despite sharing the broader ecosystem classification. However, they do tend to share significant characteristics, such as similar climate conditions, predominant plant species, and types of interactions among organisms. These common features enable ecosystems to function cohesively, supporting particular ecological processes like nutrient cycling, energy flow, and species interactions, while still exhibiting unique variations across different regions and environmental contexts.
References
Ecology | Ecological unit | [
"Biology"
] | 1,001 | [
"Ecology"
] |
57,733,812 | https://en.wikipedia.org/wiki/NGC%201270 | NGC 1270 is an elliptical galaxy located about 250 million light-years away in the constellation Perseus. It was discovered by astronomer Heinrich d'Arrest on February 14, 1863. NGC 1270 is a member of the Perseus Cluster and has an estimated age of about 11 billion years. However, Greene et al. puts the age of NGC 1270 at about 15.0 ± 0.50 Gy.
NGC 1270 has a supermassive black hole with an estimated mass of no more than 12 billion solar masses ().
Activity
Spectroscopy of NGC 1270 suggests that the galaxy contains a low-luminosity AGN (LLAGN).
NGC 1275 Group
NGC 1270 is a member of the NGC 1275 group (also known as LGG 88) which has at least 48 members, including NGC 1224, NGC 1267, NGC 1273, NGC 1275, NGC 1277, NGC 1279, IC 288, IC 294, IC 310, and IC 312.
See also
List of NGC objects (1001–2000)
NGC 1277
NGC 1271
References
External links
http://instrumentation.tamu.edu/publications/REU/KinematicsREU2015.pdf
Perseus Cluster
Perseus (constellation)
Elliptical galaxies
1270
12350
Astronomical objects discovered in 1863
2643
Active galaxies
Discoveries by Heinrich Louis d'Arrest | NGC 1270 | [
"Astronomy"
] | 285 | [
"Perseus (constellation)",
"Constellations"
] |
57,733,835 | https://en.wikipedia.org/wiki/Smother%20crop | A smother crop is a thick, rapidly growing crop that is used to suppress or stop the growth of weeds which have better root systems that help them compete with weeds for water and as a result, the root systems of weeds get weak. Meanwhile, the dense top growth of the smother crop suppresses the top growth of weeds. Effectively, smother crops successfully compete with weeds for vital resources (growth, space, water, light) and inhibit their germination and growth. Once the smother crop has served its purpose, it is ploughed under along with the weakened weeds, thus providing green fertilizer.
A good smother crop must compete strongly with weeds but minimally with the crop. Smother crops reduce dependence on chemical weed control, and are sometimes used in the transition to organic farming.
Secondary benefits of such crops include helping nitrogen fixation in soil (if legumes are used) and reducing soil erosion.
Alfalfa, hemp, rye, buckwheat, sorghum, Sudan grass, foxtail millet, sweetclover, marigold, silage corn are some examples of smother crops.
References
See also
Cover crop
Trap crop
Catch crop
Pest control
Agricultural terminology
Organic farming | Smother crop | [
"Biology"
] | 257 | [
"Pests (organism)",
"Pest control"
] |
57,733,913 | https://en.wikipedia.org/wiki/Cetobacterium | Cetobacterium is a Gram-negative, pleomorphic, non-spore-forming, rod-shaped and non-motile genus of bacteria from the family of Fusobacteriaceae.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).
See also
List of bacteria genera
List of bacterial orders
References
Further reading
Fusobacteriota
Bacteria genera | Cetobacterium | [
"Biology"
] | 105 | [
"Bacteria stubs",
"Bacteria"
] |
57,734,000 | https://en.wikipedia.org/wiki/Cetobacterium%20ceti | Cetobacterium ceti is a Gram-negative, and rod-shaped obligately anaerobic bacterium from the genus of Cetobacterium which has been isolated from sea mammals. Cetobacterium ceti represents a hitherto unknown line of descent peripherally associated to the fusobacteria and low G + C relatives. There is no growth of Cetobacterium ceti at 25°C or 45°C.
References
Fusobacteriota
Bacteria described in 1996 | Cetobacterium ceti | [
"Biology"
] | 109 | [
"Bacteria stubs",
"Bacteria"
] |
57,734,092 | https://en.wikipedia.org/wiki/Oppo%20Find%20X | The Oppo Find X is the 2018 flagship smartphone from the Oppo Find series and was launched on 19 June 2018 in Paris by Oppo. The Find X features a different design from traditional smartphones, as it has a mechanic pop-up camera. The phone has a screen to body ratio of 87%, the thinnest bezels in the market when it launched, and is considered the first "all screen" smartphone to be released.
Specifications
Hardware
It is powered by Qualcomm Snapdragon 845 processor, 8 GB of RAM, 256 GB of storage and operates on Android 8.1 (Oreo) which is Color OS customised. The pop up contains both the 25 MP front camera and dual 16 + 20 MP rear cameras. It also has a 3,730 mAh battery and is powered by VOOC fast wired charging. The Lamborghini edition of the phone comes with 512 GB storage and supports SuperVOOC fast wired charging which can charge from 0 to 100% in 35 minutes. According to Oppo, Find X will be its first phone to have global LTE compatibility which is crucial for the company to enter the European and North American market, the phone supports no fingerprint scanner to unlock the device and instead relies on facial recognition known as O-Face, which is done by the pop up taking as little as 0.5 s to pop up and unlock the phone. It is the first phone to feature an entirely virtualized (software-driven) proximity sensor, as there was no space on the front face to include such a physical sensor.
The selfie camera has 3D Smart Selfie Capture that can simulate various lighting effects for portrait lighting and it has an 3D OMoji feature while the dual rear camera can recognize 800 scenes in 20 scenarios (Food, Pets, Snow, etc.).
Software
Oppo Find X ships with Android 8.1 Oreo.
See also
Oppo phones
References
Android (operating system) devices
Mobile phones introduced in 2018
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued flagship smartphones
Oppo smartphones | Oppo Find X | [
"Technology"
] | 426 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
57,734,572 | https://en.wikipedia.org/wiki/Sneathia | Sneathia is a Gram-negative, rod-shaped, non-spore-forming and non-motile genus of bacteria from the family of Leptotrichiaceae. Species have been identified as pathogens associated with bacterial vaginosis.
Sneathia is named of the microbiologist H. A. Snaeth.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)
See also
List of bacteria genera
List of bacterial orders
References
Further reading
Fusobacteriota
Bacteria genera | Sneathia | [
"Biology"
] | 132 | [
"Bacteria stubs",
"Bacteria"
] |
57,734,923 | https://en.wikipedia.org/wiki/Pegvaliase | Pegvaliase, sold under the brand name Palynziq, is a medication used for the treatment of the genetic disease phenylketonuria (PKU). It is a phenylalanine (Phe)‑metabolizing enzyme. Chemically, it is a pegylated derivative of the enzyme phenylalanine ammonia-lyase that metabolizes phenylalanine to reduce its blood levels.
The most common adverse events include injection site reactions, joint pain, hypersensitivity reactions, headache, generalized skin reactions lasting at least 14 days, pruritus (itchy skin), nausea, dizziness, abdominal pain, throat pain, fatigue, vomiting, cough and, diarrhea.
It was approved by the US Food and Drug Administration (FDA) for use in the United States in 2018. The FDA considers it to be a first-in-class medication.
Medical uses
Pegvaliase is indicated to reduce blood Phe concentrations in adults with phenylketonuria who have uncontrolled blood Phe concentrations greater than 600 micromol/L on existing management.
Adverse effects
The FDA label for pegvaliase includes a boxed warning for anaphylaxis.
History
The safety and efficacy of pegvaliase were studied in two clinical trials in adult participants with PKU with blood phenylalanine concentrations greater than 600 μmol/L on existing management. Most PKU participants in the pegvaliase trials were on an unrestricted diet prior to and during the trials. The first trial was a randomized, open-label trial in participants treated with increasing doses of pegvaliase administered as a subcutaneous injection up to a target dose of either 20 mg once daily or 40 mg once daily. The second trial was an 8-week, placebo-controlled, randomized withdrawal trial in participants who were previously treated with pegvaliase. Participants treated with pegvaliase achieved statistically significant reductions in blood phenylalanine concentrations from their pre-treatment baseline blood Phe concentrations.
The FDA granted approval of Palynziq to BioMarin Pharmaceutical.
References
Drugs acting on the gastrointestinal system and metabolism
Recombinant proteins
Orphan drugs | Pegvaliase | [
"Biology"
] | 466 | [
"Recombinant proteins",
"Biotechnology products"
] |
71,592,369 | https://en.wikipedia.org/wiki/Carbohydrate%20Polymers | Carbohydrate Polymers is a peer-reviewed scientific journal that covers the entire scope of carbohydrate polymers and the research and exploitation of polysaccharides. The journal is published by Elsevier.
Abstracting and indexing
The journal is abstracted and indexed in several databases including:
Science Citation Index
Web of Science
Polymer Contents
According to the Journal Citation Reports, the journal has a 2022 impact factor of 11.2.
References
External links
Organic chemistry journals
Polymer science journals
Carbohydrate chemistry
Elsevier academic journals | Carbohydrate Polymers | [
"Chemistry",
"Materials_science"
] | 111 | [
"Organic chemistry journals",
"Polymer science journals",
"Carbohydrate chemistry",
"Polymer chemistry",
"Chemical synthesis",
"nan",
"Glycobiology"
] |
71,592,492 | https://en.wikipedia.org/wiki/7-Methylxanthine | 7-Methylxanthine (7-MX), also known as heteroxanthine, is an active metabolite of caffeine (1,3,7-trimethylxanthine) and theobromine (3,7-dimethylxanthine). It is a non-selective antagonist of the adenosine receptors. The compound may slow the progression of myopia (nearsightedness). It is under investigation for this purpose in children with myopia.
It is shown that systemic treatment with 7-MX appears to be efficient in retarding axial elongation and myopia progression among myopic children. The treatment is safe and without side effects, and may be continued until 18–20 years of age, when age-related cross-linking of collagen prevents further elongation of the eye. Additionally, further studies show that oral intake of 7-MX was associated with reduced myopia progression and reduced axial elongation in this sample of myopic children from Denmark. Randomized controlled trials are needed to determine whether the association is causal.
References
Adenosine receptor antagonists
Experimental drugs
Human drug metabolites
Ophthalmology drugs
Xanthines | 7-Methylxanthine | [
"Chemistry"
] | 257 | [
"Alkaloids by chemical classification",
"Xanthines",
"Human drug metabolites",
"Chemicals in medicine"
] |
71,592,725 | https://en.wikipedia.org/wiki/FAM177A1 | Family with sequence similarity 177 member A1 (FAM177A1) is a protein that in humans is encoded by the FAM177A1 gene, previously known as C14orf24. The other member of this family is FAM177B.
Function
FAM177A1 has been linked to immune system regulation and to neurogenesis.
Interactions
IntAct reports physical interactions between FAM117A1 and these other human proteins:
Aquaporin-6
Caspase 6
DPM3
ELOVL4
FATE1
JAGN1
LAMP2
PBX3
SGPL1
SH3GLB1
TMX2
References
External links
FAM177A1 Research Fund (for FAM177A1 Associated Disease) | FAM177A1 | [
"Chemistry"
] | 148 | [
"Biochemistry stubs",
"Protein stubs"
] |
71,592,942 | https://en.wikipedia.org/wiki/FAM177B | Family with sequence similarity 177 member B (FAM177B) is a protein that in humans is encoded by the FAM177B gene. The other member of this family is FAM177A1.
References | FAM177B | [
"Chemistry"
] | 47 | [
"Biochemistry stubs",
"Protein stubs"
] |
71,594,556 | https://en.wikipedia.org/wiki/Lattice%20Boltzmann%20methods%20for%20solids | The Lattice Boltzmann methods for solids (LBMS) are a set of methods for solving partial differential equations (PDE) in solid mechanics. The methods use a discretization of the Boltzmann equation(BM), and their use is known as the lattice Boltzmann methods for solids.
LBMS methods are categorized by their reliance on:
Vectorial distributions
Wave solvers
Force tuning
The LBMS subset remains highly challenging from a computational aspect as much as from a theoretical point of view. Solving solid equations within the LBM framework is still a very active area of research. If solids are solved, this shows that the Boltzmann equation is capable of describing solid motions as well as fluids and gases: thus unlocking complex physics to be solved such as fluid-structure interaction (FSI) in biomechanics.
Proposed insights
Vectorial distributions
The first attempt of LBMS tried to use a Boltzmann-like equation for force (vectorial) distributions. The approach requires more computational memory but results are obtained in fracture and solid cracking.
Wave solvers
Another approach consists in using LBM as acoustic solvers to capture waves propagation in solids.
Force tuning
Introduction
This idea consists of introducing a modified version of the forcing term: (or equilibrium distribution) into the LBM as a stress divergence force. This force is considered space-time dependent and contains solid properties
,
where denotes the Cauchy stress tensor. and are respectively the gravity vector and solid matter density.
The stress tensor is usually computed across the lattice aiming finite difference schemes.
Some results
Force tuning has recently proven its efficiency with a maximum error of 5% in comparison with standard finite element solvers in mechanics. Accurate validation of results can also be a tedious task since these methods are very different, common issues are:
Meshes or lattice discretization
Location of computed fields at elements or nodes
Hidden information in software used for finite element analysis comparison
Non-linear materials
Steady state convergence for LBMS
Notes
References
Biomechanics
Fluid dynamics
Thermodynamics | Lattice Boltzmann methods for solids | [
"Physics",
"Chemistry",
"Mathematics",
"Engineering"
] | 413 | [
"Biomechanics",
"Dynamical systems",
"Chemical engineering",
"Mechanics",
"Thermodynamics",
"Piping",
"Fluid dynamics"
] |
71,594,825 | https://en.wikipedia.org/wiki/Parmotrema%20tinctorum | Parmotrema tinctorum is a lichen which belongs to the Parmotrema genus. The lichen is as known as the Palm Ruffle Lichen and is listed as secure by the Nature Conservatory.
Description
Grows to around 3–30 cm in diameter with board dull smooth slightly shiny gray lobes that are 10–20 mm wide. The underside is black with naked brown areas with a central collection of simple rhizines.
Habitat and range
Global distribution with a majority of samples being located in North America and Europe.
Chemistry
Compounds derived from Parmotrema tinctorum have been found to have anti-cancer properties.
Environmental monitoring
Parmotrema tinctorum has been identified and used as a candidate for monitoring air pollution.
See also
List of Parmotrema species
References
Lichen species
tinctorum | Parmotrema tinctorum | [
"Biology"
] | 168 | [
"Fungus stubs",
"Fungi"
] |
71,595,386 | https://en.wikipedia.org/wiki/Omega%20Octantis | Omega Octantis, (latinized from ω Octantis), is a solitary, bluish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.87, allowing it to be faintly seen with the naked eye. Based on the object's parallax measurements, it is estimated to be 328 light years distant. However, it is drifting closer with a heliocentric radial velocity .
Omega Octantis has a stellar classification of B9.5 V, indicating that it is a main-sequence star between the B9 and A0 classes. Helmut A. Abt & Nidia I. Morrell gave a slightly updated class of B9.5 Vs, which includes sharp (narrow) absorption lines in Omega Octantis' spectrum due to slow rotation. It has a mass 2.54 times that of the Sun and is calculated to be 197 million years old, having completed 40% of its main sequence lifetime. It has a luminosity of , which comes from a radius of and an effective temperature of . In 2012, George A. Gontcharov calculated a solar metallicity for Omega Octantis, and it is spinning modestly with a projected rotational velocity of . The slow rotation is consistent with the spectral classification from Abt & Morell (1995).
References
B-type main-sequence stars
Octans
Octantis, Omega
Octantis, 23
PD-84 00490
131596
074296
5557 | Omega Octantis | [
"Astronomy"
] | 313 | [
"Octans",
"Constellations"
] |
71,595,967 | https://en.wikipedia.org/wiki/Walter%20H.%20Waddell | Walter H. Waddell is a retired ExxonMobil Chemical senior research associate and consultant to the tire and rubber industry with expertise in silica technology, rubber compounding, butyl polymer applications and tire aging. Since 2015 he has served on the technical committee of the International Tire Exhibition & Conference (ITEC) for Tire Manufacturing.
Education
Waddell received his BS in Chemistry at University of Illinois Chicago in 1969 and his PhD from University of Houston in 1973. He held a postdoctoral research position at Columbia University until 1975.
Career
Waddell's first professional post was as an associate professor of chemistry at Carnegie-Mellon University. In 1983 he joined Goodyear research as a section head. In 1990 he joined PPG Industries as a senior scientist developing silica technology. In 1996 he joined ExxonMobil as a senior research associate in specialty Polymers Technology, retiring in 2015. Following his retirement, he has consulted on rubber technology for Cheng Shin Rubber Industrial Co. Ltd. Oriental Silicas Corp. and Smithers. He holds an appointment as an adjunct professor at Beijing University of Chemical Technology. Since 2015 he has served on the technical committee of the International Tire Exhibition & Conference (ITEC) for Tire Manufacturing.
Awards and recognition
1993 - Sparks–Thomas award
2003 - Melvin Mooney Distinguished Technology Award from the ACS Rubber Division
2020 - Harold Herzlich Distinguished Technology Achievement Medal
References
Polymer scientists and engineers
20th-century American engineers
Year of birth missing (living people)
Living people
ExxonMobil people
Tire industry people | Walter H. Waddell | [
"Chemistry",
"Materials_science"
] | 309 | [
"Polymer scientists and engineers",
"Physical chemists",
"Polymer chemistry"
] |
71,597,444 | https://en.wikipedia.org/wiki/Cambodian%20mat | A Cambodian mat also known as a kantael (Khmer: កន្ទេល) is a woven mat made from palm or reed in Cambodia. The Cambodian mat consists of an ordinary mat, below which are fixed pads of strongly packed cotton, with the help of a special loom. They are specific to the Khmer people.
History
Mats have been woven in Cambodia since Angkorian times, as evidenced by carvings on the bas-relief of Angkor Wat.
When the French missionary Charles-Émile Bouillevaux, after being the first Frenchmen to discover Angkor Wat, traveled to the Eastern bank of the Mekong and encountered the Bunong people, he considered it an honour to be invited to sit on a Cambodian mat.
During his exploration trip in the 1880s, the French anthropologist Edouard Maurel acknowledged that there was something unique to the Cambodian mat, which he took as evidence of the luxury of the once flourishing Khmer civilization:
Auguste Pavie during his exploration of Cambodia, noticed that the King of Cambodia himself could sit on this type of Cambodian mat.
At the end of the XIXth century, the Cambodian mat was seen as the model for all the straw mats across Asia. Thus, French explorers in Vietnam refer to these straw mats as "Cambodian mats" while explorers in Yunnan described the beads of Chinese peasants as made of three planks on wooden trestles covered with rice straw and a Cambodian mat on top.
The French protectorate of Cambodia promoted the export of Cambodian mats. The Cambodian mat was promoted as "a fine and neat article" which attracted the attention of Japanese merchants at the Hanoi Exhibition in 1903; it was often sold in Saigon stuffed with kapok. Rather than Picot camp beds which were heavy and difficult to carry around in Indochina, the French colonialists recommended the use of Cambodian mats when travelling in French Indochina.
Unfortunately, woven plant mats have been largely supplanted by colored plastics mats imported from Thailand and Vietnam since 1981.
Since the beginning of the 21st century, weavers have learned how to dye and design patterns such as lanterns, pineapple eyes, grids, and strings.
In 2017, the French Cultural Center in Cambodia organized a itinerant exhibition called Mats and Table towels (Nattes et Nappes) which saw table cloths and sitting mats as two distinctive elements of France and Cambodia respectively.
The Cambodia Sedge Mats Business Association (CSMA) was set up to work as a trade organisation and promote Cambodian mats on the national and international markets. As of 2022, the Cambodian mats remain widely popular within the country and natural mats are preferred to nylon mats.
Production
The region of Cambodia best-known for mat weaving is the Mekong floodplain, especially around Lvea Aem district. Mats are usually a cottage industry woven by craftswomen sitting on mats in their private homes. The most popular mats in Cambodia are made of mangrove fan palm. While they are more rare, Cambodian mats can also be made of wicker and rattan (tbanh kanchoeur) made from dryandra trees. Reeds are usually grown on the edge of rice fields for making mats when the water recedes from the lake behind their village during the dry season when weaving is done from January to May.
Cambodian mats can be made from a variety of sedges, rattan and leaves such as grey sedge, rice sedge, red nut sedge, cool mat, Calamus viminalis or Khmer rattan, mangrove fan palm, palm leaves, banana leaves, talipot palm leaves, sago palm leaves and water hyacinth.
Mangrove palm tree mats: kantael pa'au
The mangrove palm tree first needs to be cut and divided into three sections: one is the central spine, and the two other is the soft wings on both sides. The fiber is then split and flattened. The shell is peeled off, and only the soft thread remains. They are then dried in the sun for a whole day and collected in bundles in the shade. Water is sprayed regularly to prevent the fiber from drying out and twisting. The threads are then sorted apart, with the long threads apart for weaving mats.
Red mats: kantael krahom
Red mats or kantael krahom are a kind reed mat woven from the bark of the red nut sedge known in Khmer as kravanh chruk. Craftsmen cut the reeds into small pieces of one meter length before dying the fibers of the cuttings by dipping them in red, white, green and yellow according to their preferred color. Cambodian red mats were exported and sold in Vietnam at least since the 19th century. Red mats are usually weaved with white reeds that are not diked at one top side to identify its orientation as it would be inconvenient that the head lay were the feet have trodden. It is a secondary source of income for Cambodian farmers who can add up to 2000 US dollars to the yearly revenue by weaving these red mats.
Water hyacinth mats: kantael komplaok
In recent years, Khmer people have also made mats for tableware and sleeping from dried water hyacinth. In fact, the plant, despite its beauty is fast-growing and often clogs waterways on the Tonle Sap. While its soft texture has made it popular, its durability is limited.
Use
Cambodian mats are an important piece of furniture in all Cambodian homes where such furniture is usually limited. Traditionally, palm mats were used both for as a sleeping mattress and a tablecloth on which families sit while they share their meals.
Mats are commonly laid out for guests and are important building materials for homes, and they are often used as wedding gifts.
During religious ceremonies, Cambodian people do not usually sit on chairs or bare floors but rather on mat-covered floors.
While these Cambodian mats were for family use, they have become popular among urban Khmer people and foreign tourists for decoration.
Literature
The French author Claude Farrère refers often to the Cambodian mat in Les Petites Allées, Le Quadrille des Mers de Chine, and La Sonate à la Mer, as an exotic reference to the colonial fantasm, which can also be found in the novel Lélie, fumeuse d'opium published under pseudonym and illustrated with pin-up illustrations of nude and semi-nude women by Raphael Kirchner.
References
External links
Interior design
Khmer folklore
Straw products
Units of area | Cambodian mat | [
"Mathematics"
] | 1,304 | [
"Quantity",
"Units of area",
"Units of measurement"
] |
71,601,495 | https://en.wikipedia.org/wiki/Lingzi | (), also called (), refers to a traditional Chinese ornament which uses long pheasant tail feather appendages to decorate some headdress in , Chinese opera costumes. In Chinese opera, the not only decorative purpose but are also used express thoughts, feelings, and the drama plot. They are typically used on the helmets of warriors, where a pair of pheasant feathers extensions are the indicators that the character is a warrior figure; the length of the feathers, on the other hand, is an indicator of the warrior's rank. The are generally about five or six feet long. Most of the time, are used to represent handsome military commanders.
Origins
It is suggested that the use of originated from the (), a form of used by the military officials since the ancient times. Similar headgear decorated with pairs of worn the military can be seen in paintings dating to the Ming dynasty.
Wuguan
During the Warring States period, King Wuling of Zhao adopted the policy and a -style which looks similar to the conical hat of the Scythian was adopted. King Wuling's -style was less pointy than the actual Scythian hat and he decorated his hat with a marten tail to denote his noble status. The King of Qin later give the -style of King Wuling to his servant as an insult to King Wuling after the latter had destroyed the regime of the Zhao state.
King Huiwen of Zhao later wore the same -style as his father, King Wuling; and therefore this type of was named (). Many years later, the evolved into the military cap called .
By the Han dynasty, a decorated with pheasant feathers became known as () and was used by the military officials of the Han dynasty. The was first worn in the state of Zhao to distinguish military officers during the Warring States period. The was possibly itself derived from the -style adopted by King Wuling through policy. The snow pheasant () was a symbolism of martial valour and courage due to its association with the snow pheasant which would fight its opponent until death.
Skills and manipulation
The skills required to manipulate the two pheasant feathers are known as . These skills include shaking and swinging; sometimes the are shaken with one hand but sometimes two hands are used. The skills of are used by many roles; however, they are especially used in the role.
When combined the movements of the head and body of the actor, the movement of the express the feelings and dispositions of the character, which include the expression of surprise, hatred, happiness, and frivolity.
See also
Chinese opera
– Chinese opera costume
Hanfu
Guzhuang
Gallery
Notes
References
Chinese traditional clothing
Chinese opera
Costume design | Lingzi | [
"Engineering"
] | 557 | [
"Costume design",
"Design"
] |
71,602,244 | https://en.wikipedia.org/wiki/COVID-19%20proxalutamide%20trial%20in%20Brazil | In the wake of the global COVID-19 pandemic, several lines of research targeted the development of a pharmaceutical treatment or cure for the disease. One of those researches involved a clinical trial that took place in Brazil and was led by Brazilian endocrinologist Flávio Cadegiani.
Background
In the beginning of the pandemic, it was believed that men were generally more prone to the illness than women and as a result of that, some researchers explored human male hormone blockers, also known as antiandrogens, as a treatment. The trial led by Cadegiani looked at the experimental prostate cancer and antiandrogen proxalutamide, and people from the Brazilian region of Amazon were recruited as patients in the study, given the surge in Covid-19 cases in that region in the early months of the COVID-19 pandemic in Brazil which would, according to the study's author, favor the accuracy of the research.
Brazilian president Jair Bolsonaro backed the unproven use of proxalutamide drug to treat Covid-19 as well as he previously did with ivermectin and hydroxychloroquine, both of which are also unproven treatments for the virus.
Method
A total of 645 patients with Covid-19 were administered proxalutamide at nine hospitals in the Brazilian Amazon region. When they were first admitted to hospital, none required mechanical ventilation at the start of the study. The care consisted of medicines such as enoxaparin, colchicine, methylprednisolone, dexamethasone, or antibiotic therapy as necessary and some of them were given unproven Covid-19 treatments drugs such as ivermectin. Altogether, 317 patients received proxalutamide and 328 a placebo. Brazilian National Health Council (CNS) later reported such treatment was prescribed by doctors in a private hospital network as if it were an established medical treatment, despite it was approved only for clinical trial studies. The number of people who were given the drug was also larger than the number approved for the trial.
The trial, which was not peer-reviewed, reported that the 14 day recovery rate of patients was 81.4% with proxalutamide and 35.7% with placebo. Jesem Orellana, an epidemiologist who closely watched the effects of the gamma variant of Covid-19 on the Amazon region at Brazil's leading public health institute Fiocruz, said "the reported results would be a miracle — if they were true" adding that "everything about this trial is suspicious and is anything but clinical and randomised".
Aftermath
Brazil's National Ethics Commission on Research (CONEP) found that 200 people died after undergoing the study and at least 40 deaths were hidden in the study's conclusions. The consent form handed to the study's patients omitted the risk of birth defects and other potential injuries from the procedures, according to the commission. It was later reported that the patients, some of which were hospitalised in intensive care units at the time, trusted the doctors participating in the study because they were desperate for a Covid-19 treatment or cure for their relatives or themselves, as the region was hit the hardest in the world at the time the study was being conducted and the entire local healthcare system had collapsed due to a major surge in Covid-19 cases.
After the study's preprint was published in June 2021, several scientists warned it was deeply flawed and a Brazilian research ethics commission opened an investigation into it. Science Magazine also reported that Applied Biology, a Californian hair loss company, where Cadegiani is a clinical director, teamed up with Kintor Pharmaceuticals, proxalutamide's manufacturer based in China. Additionally, UNESCO office for Latin America and Caribbean found the way the study was conducted is "alarming" and that several gross ethics violations were committed. It said the study could be one of the gravest ethical scientific misconduct in the region's history and urged an investigation into the case.
On September 2, 2021, Brazil's health regulator Anvisa suspedend the prescription, usage and importation of proxalutamide in the country, and opened a separate probe about the study. On September 3, 2021, a criminal complaint was filed before Brazil's Public Prosecutor office in order to investigate the actions taken during the study as well as the consequences of it, including the patients deaths.
On June 27, 2022, academic journal Frontiers in Medicine retracted the mentioned study it had initially published in July 2021. Similarly, the BMJ Case Reports journal labeled another article based on the same study and authored by Cadegiani as an "expression of concern". On August 25, 2022, Brazilian Federal Police carried out several search and seizure warrants against public officials, doctors and researchers who led proxalutamide trials in the Brazilian southern state of Rio Grande do Sul and elsewhere in the country. Although no names of the suspects targeted by the operation were revealed, Cadegiani said on his social media that his house and clinic were raided by the police.
In August 2022 Brazilian Federal prosecutors charged two researchers who ran the medical trial in two separate civil lawsuits as well as three hospital officials who reportedly aided them. The defendants can be fined in at least R$10 million (about US$1,917,582) in both suits if convicted.
See also
Scientific misconduct
Patient abuse
Unethical human experimentation
Covid-19 pandemic in Brazil
References
COVID-19 pandemic in Brazil
Scientific misconduct incidents
Scientific misconduct | COVID-19 proxalutamide trial in Brazil | [
"Technology"
] | 1,156 | [
"Scientific misconduct",
"Ethics of science and technology"
] |
71,604,473 | https://en.wikipedia.org/wiki/Zwackhiomyces%20calcariae | Zwackhiomyces calcariae is a species of lichenicolous fungus in the family Xanthopyreniaceae. It was first formally described in 1896 by French lichenologist Camille Flagey, as Arthopyrenia calcariae. Josef Hafellner and Nikolaus Hoffmann transferred it to the genus Zwackhiomyces in 2000. The fungus is parasitic on lichens in genus Aspicilia.
References
Xanthopyreniaceae
Fungi described in 1896
Lichenicolous fungi
Fungus species | Zwackhiomyces calcariae | [
"Biology"
] | 109 | [
"Fungi",
"Fungus species"
] |
71,605,007 | https://en.wikipedia.org/wiki/Toyota%20L-series%20%28HSD%29%20Transmission | Toyota Motor Corporation's L-series of HybridSynergyDrive (HSD) transmissions (not to be confused the 4 and 5 speed manual L-series Toyota transmissions) are hybrid gearboxes containing 2 electric motors, one for driving the wheels and one for controlling the ratio between the engine and the electric drive motor, as well as an optional 2 or 4 speed planetary transmission attached to the end of the HSD device OR a conventional automatic transmission that uses an electric drive motor instead of a torque converter for additional vehicle propulsion.
Toyota L110 / L110f
The L110 transmission is used in the Lexus GS450h 2006-2020 and the AWD L110f variant is used in the 2007-2016 LS600h / LS600hl.
There are two motors contained inside the L110 transmission's HSD: MG2 which is connected to the output of the and MG1 which is connected between MG2 and the internal combustion engine. MG1 varies the connection between the engine and the wheels. Both MG1 and MG2 are 3 phase motors powered by an inverter connected to an Ni-MH battery back. The L110f housing includes an LF1A TORSEN LSD transfer. For more information please see: Hybrid vehicle drivetrain.
The L110/f contains a 2 speed Ravigneaux gear set for reducing the final ratio from the HSD to the wheels, the vehicle uses the first gear to get moving under purely electric power from MG2, before moving into second gear. If the ICE is on, then the transmission will switch to gear 2, therefore first gear is only used to get the car moving under electric power.
The L110 transmission utilises both a mechanical, engine driven oil pump and an electric oil pump for use when the ICE is off. The L110 utilises a "sequential shiftmatic system" simulating 8 different fixed gear ratios selectable by the driver.
Toyota L210
The L210 transmission is used in the Lexus RC300h, GS300h and IS300h. It features an EV only mode where the car can run purely from electric power, similar to the L110f. The L210 has a maximum power output of with a peak torque of .
The L210 optionally came with a 6-step sequential gear change function selectable by paddles on the steering wheel.
The IS300h pairs the L210 with a 650 Volt, 192 cell NiMH battery pack.
Toyota L310 / L310f
The L310 transmission is used in the LC500h and LS500h and Crown Hybrid paired with the 8GR-FXS engine. The L310f AWD variant is used in the AWD LS500h. The L310/f is paired with Li-ion batteries in the LC/LS.
It combines a hybrid power split device with a 4-speed planetary gearset and comes with 10 pre-programmed shifts to simulate a tiptronic transmission.
Simulated Ratios:
First Gear: 4.701:1
Second Gear: 3.5:1
Third Gear: 2.801:1
Fourth Gear: 2.241:1
Fifth Gear: 1.793:1
Sixth Gear: 1.436:1
Seventh Gear: 1.197:1
Eight Gear: 0.998:1
Ninth Gear: 0.767:1
Tenth Gear: 0.58:1
Which are derived from the following physical ratios in the 4 speed transmission:
First Gear: 3.538:1
Second Gear: 1.888:1
Third Gear: 1.000:1
Fourth Gear: 0.650:1
L4xxx
FR/4WD Transmission
L4A0E
10-speed automatic Transmission
Applications (calendar years):
2021-present Toyota Tundra 3.4LTT Hybrid RWD
Gear ratios:
L4A0F
10-speed automatic Transmission
Applications (calendar years):
2021-present Toyota Tundra 3.4LTT Hybrid 4WD
Gear ratios:
References
Toyota transmissions
Lexus
Hybrid powertrain
Engine technology | Toyota L-series (HSD) Transmission | [
"Technology"
] | 859 | [
"Engine technology",
"Engines"
] |
71,605,294 | https://en.wikipedia.org/wiki/UGC%202369 | UGC 2369 is a pair of galaxies and interacting galaxies in the constellation Aries, about 424 million light-years away. The two galaxies are called UGC 2369N and UGC 2369S.
A tenuous bridge of gas, dust and stars can be seen connecting the two galaxies, created when they pulled material out into space across the diminishing divide between them. Interaction between galaxies is not an uncommon event, however, two similarly sized ones merging is rare. The images released by NASA show both the galaxies distorting as they pulled closer. In the images, a thin bridge of gas, dust and stars can also be seen. The ridge was developed when the gap between both of the galaxies started diminishing.
See also
Mice Galaxies
NGC 4302
Antennae Galaxies
References
Interacting galaxies
02369
Aries (constellation) | UGC 2369 | [
"Astronomy"
] | 172 | [
"Aries (constellation)",
"Constellations"
] |
71,606,024 | https://en.wikipedia.org/wiki/Lamp%20cord%20trick | In topology, a branch of mathematics, and specifically knot theory, the lamp cord trick is an observation that two certain spaces are homeomorphic, even if one of the components is knotted. The spaces are , where is a hollow ball homeomorphic to and a tube connecting the boundary components of . The name comes from R. H. Bing's book "The Geometric Topology of 3-manifolds".
References
Lucien Grillet, La Conjecture de Smith en faible régularité.
Knot theory | Lamp cord trick | [
"Mathematics"
] | 100 | [
"Geometry",
"Geometry stubs"
] |
71,607,646 | https://en.wikipedia.org/wiki/Betty%20Lindsay | Betty Lindsay (Minnie Elizabeth Barclay Lindsay) (9 October 1897 – 11 January 1953) was an early professional civil engineer working in Albania and, in 1921, may have been only the second female engineering graduate (after Elizabeth Georgeson in 1919) of the University of Edinburgh.
Early life and education
Betty Lindsay was born in China but her family returned to Scotland when she was three years old. Her father, Edward John Lindsay was a banker. Both her parents died by 1913 so she went to live with her uncle in Evie, Orkney. In 1921 she obtained a BSc in mechanical engineering from the University of Edinburgh (she had also been awarded a second-class certificate of merit in mechanical engineering during her studies). In her career, however, she worked mainly as a civil engineer. From 1922 to 1925 she worked for William Tawse Ltd as an engineering assistant.
Work in Albania
Lindsay was a Scottish member of the Women's Engineering Society and in 1926 its journal, The Woman Engineer, reported that she had volunteered for an anti-malarial mission to Albania, which also included female doctors, a nurse and a driver. The mission had been organised by Lady Carnarvon; she had established schools, hospitals and clinics in Albania after the death in 1923 of her son, Aubrey Herbert, who had been a leading advocate of Albanian independence. The article noted that having arrived at the State Hospital, Valona (Vlorë), on 21 March that year, she undertook duties which ‘at present consist of organising and supervising the work of draining, ditching and filling in pits, etc., and in clipping for and examining mosquito larvae’.
Lindsay remained in Albania until the outbreak of the Second World War in 1939, working on anti-malarial civil engineering projects throughout the country, and with the Rockefeller Foundation Malarial control engineer, Frederick W. Knipe, and International Health Board ecologist Dr Lewis W. Hackett.
Later life
She then returned to the UK and became a technical translator for the Air Ministry, where she remained working, latterly as Chief Translator, until her death in 1953. She was buried in the family grave in Edinkillie, Morayshire.
Sources
1897 births
1953 deaths
20th-century Scottish women engineers
20th-century Scottish engineers
Women's Engineering Society
20th-century British women engineers
Alumni of the University of Edinburgh
Malariologists
Civil engineers
Scottish civil engineers
People from Orkney | Betty Lindsay | [
"Engineering"
] | 485 | [
"Civil engineering",
"Civil engineers"
] |
71,608,073 | https://en.wikipedia.org/wiki/Lanz%20HL | The Lanz HL, also known as Lanz Bulldog HL and Lanz Bulldog HL 12, is an agricultural machine and tractor made by Heinrich Lanz & Co. OHG. It was developed by German engineer Fritz Huber and is the first Lanz tractor to feature the "Bulldog" Akroyd engine. Thus, it is the first series production Lanz Bulldog. The Lanz HL was introduced at the 1921 DLG agriculture fair in Leipzig and stayed in production until 1927. In total, more than 6,000 units were made. The HL Bulldog engine was also sold as a stationary engine; this article primarily describes the HL agricultural tractor.
Technical description
The Lanz HL is an agricultural machine that resembles, in its default configuration, an agricultural tractor. Nonetheless, the Lanz HL was not primarily designed as a tractor; it is rather a self-propelled farm implement motor. Various different versions were made, with rubber or steel wheels. It uses a frameless design with the rear axle flange-mounted to a housing shaped like a "hull" that spans to the tractor's front. This "hull" contains the water tank for the cooling system and a toolbox. The rear axle is a live 90°-portal-type beam axle with a single-speed reduction gearbox and a differential gearbox; the front axle – that the "hull"-shaped housing sits atop on – is a dead boogie axle that does not have steering knuckles.
The Lanz HL has a worm-and-sector steering system and a conventional steering wheel. The engine is top flange-mounted to the "hull". Torque is sent to a pulley and torque take-off disc that can be engaged or disengaged through a simple lever-operated jaw-type clutch. From the pulley and torque take-off disc, torque can either be sent to a farm implement through a belt, or to the rear axle's reduction gearbox through a chain. This means that the drive chain has to be uninstalled when the Lanz HL is to be used as a farm implement motor. In its original configuration, the Lanz HL has no gearboxes other than the rear axle's reduction and differential gearboxes, which limits its top speed to 4.2 km/h. From 1923, Lanz offered an additional shiftable gearbox as a factory option. This gearbox has two speeds and has to be shifted while the vehicle is standing still. Due to the engine's design, it can run either clockwise or counterclockwise, which eliminates the need for a dedicated reverse gear or reverse gearbox. With the two-speed gearbox, speeds of up to 12 km/h, either forward or reverse, are possible. The brakes are simple shoe brakes that act directly on the wheels' treads.
The engine is a single-cylinder, two-stroke Akroyd engine designed by German engineer Fritz Huber (hence the name "HL", Huber Lanz). It is named the "Bulldog" engine because of its ignition device's characteristic appearance that bears resemblance to a bulldog. The Bulldog engine of the HL has intake ports instead of valves and uses simple evaporative cooling. The water vapour leaves the engine through the exhaust of the engine. With its bore of 190 mm and its stroke of 220 mm it displaces cm3. The rated power output is 12 PS (ca. 9 kW) at 420/min. Later versions of the same engine were also offered with 15 PS (ca. 11 kW) at 500/min for stationary applications. The Bulldog engine can burn a huge variety of liquid fuels, most notably cheap fuel oils. The fuel is sprayed into the ignition device – an uncooled portion of the cylinder head – where it vapourises and eventually gradually combusts. Thus, the engine needs no carburetor like Otto engines, and no high compression like Diesel engines (in the Bulldog engine, the compression is ε≤5). Prior to starting the engine, the ignition device has to be brought to ignition temperature using a blow torch. The engine is then flywheel-started by hand.
External links
References
Tractors | Lanz HL | [
"Engineering"
] | 862 | [
"Engineering vehicles",
"Tractors"
] |
71,609,397 | https://en.wikipedia.org/wiki/Voice%20over%20NR | Voice over New Radio or Voice over 5G (acronym VoNR or Vo5G) is a high-speed wireless communication standard for voice services over 5G networks, utilizing mobile phones, data terminals, IoT devices, and wearables. Like 4G networks, 5G does not natively support voice calls traditionally carried over circuit-switched technology. Instead, voice communication is transmitted over the IP network, similar to IPTV services. To address this, Voice over NR (VoNR) is implemented, allowing voice calls to be carried over the 5G network using the same packet-switched infrastructure as other IP-based services, such as video streaming and messaging.
Similar to how VoLTE enables voice calls on 4G networks, VoNR (Vo5G) serves as the 5G equivalent for voice communication, but it requires a 5G standalone (SA) network to function. VoNR offers better voice quality than its 4G predecessor, primarily due to the inherent lower latency of 5G NR, allowing for faster call setup and improved overall communication. Additionally, VoNR removes the LTE anchor, enabling the voice call to stay entirely within the 5G network.
VoNR (Vo5G) calls are generally charged at the same rate as other calls, and to make a VoNR call, the device, its firmware, and the mobile telephone provider must all support the service and work together in the specific area.
See also
Voice over LTE
Video over NR (ViNR)
IMT-2020 – the International Telecommunication Union standards
List of 5G NR networks
References
External links
What is 5G VoNR?
Standalone 5G vs. Non-Standalone 5G
5G | ShareTechnote
5G (telecommunication)
Mobile technology
Telecommunications-related introductions in 2021
Voice over IP | Voice over NR | [
"Technology"
] | 362 | [
"Mobile technology stubs",
"nan"
] |
64,324,340 | https://en.wikipedia.org/wiki/Slayton%20A.%20Evans%20Jr. | Slayton A. Evans Jr. (May 17, 1943 – March 24, 2001) was an American chemist and professor at the University of North Carolina, Chapel Hill. He was a leading researcher into organophosphorus chemistry. His research led to a greater understanding of the functions of organophosphate compounds and innovations in methods to produce chemical compounds for pharmaceutical drugs.
Early life and education
Slayton Alvin Evans Jr. was born on May 17, 1943, in Chicago, Illinois, to Corine M. Thompson Evans and Slayton A. Evans, Sr. Months later, his father was called to serve in World War II. When Slayton was three years old, the family moved to Meridian, Mississippi, where they lived in a segregated public housing project and his father worked at a J. C. Penney store. Slayton's interest in chemistry began early, when he was given a chemistry set. In addition, a small microscope allowed him to study various plant specimens and insects. Evans and his two younger siblings enrolled at a segregated primary school run by the Roman Catholic Church, and later he attended St. Joseph's High School. In 1957, when Evans was in the ninth grade, news of the artificial satellite Sputnik inspired him to learn about rocketry and attempt to build his own. While he was given permission by the nuns at his school to buy chemicals to make rocket fuel, he had to make his own powdered charcoal. He built six rockets, two of them achieving liftoff.
Evans helped pay for his school tuition by mowing lawns and during eighth grade he was a junior assistant janitor at his elementary school. Later he worked in the high school cafeteria. In his third year of high school, he considered going into the Air Force, but was too tall for flight training. However, he took several competitive examinations and was the recipient of an academic scholarship to Tougaloo College where he also received an athletic scholarship for basketball. He enrolled at Tougaloo in 1961.
By the end of his first year, Evans had top marks in chemistry in his class. He got a summer job working for the pharmaceutical company Abbott Laboratories in Chicago where he was tasked first with creating chemical compounds from raw materials, and later with identifying the stages of chemical reactions. Evans graduated from Tougaloo with a Bachelor of Science in chemistry in 1965. Evans was encouraged to attend graduate school, though he didn't know how to pay for it. He briefly attended the Illinois Institute of Technology before transferring to Case Western Reserve University in Cleveland, Ohio, where he was offered a research assistant position in the chemistry department. In his first year, he received a draft notice to go to the Vietnam War. University officials contacted the draft board and explained that Evans' research was crucial to the war effort. He was researching a medicine to treat schistosomiasis, a disease caused by parasitic flatworms that are common in Southeast Asia. He completed his coursework in 1969 and received his Ph.D. in chemistry in early 1970.
Research and academic career
Evans took a postdoctoral fellowship at the University of Texas at Arlington for the 1970–1971 academic year, followed by second fellowship at the University of Notre Dame in Indiana, where he worked with the organic chemist Ernest L. Eliel studying stereochemistry. Upon the completion of the fellowship, he was invited to be a research instructor at Dartmouth College in 1972, though they did not have the laboratory equipment he required to continue his research. Evans then joined the faculty of the University of North Carolina at Chapel Hill as an assistant professor of chemistry in 1974. He was the first African-American chemistry professor at the university. After 10 years at Chapel Hill, Evans became a full professor, and in 1992 was honored with a Kenan Professor chair.
Evans was a leading researcher in the field of organophosphorus chemistry, authoring more than 85 scientific articles on organosulfur and organophosphorus chemistry. His research led to a deeper understanding of the functions of organophosphate compounds and innovations in methods to produce chemical compounds for pharmaceutical drugs. Evans was inspired by William Standish Knowles, who in 1968 developed a method of asymmetric hydrogenation, which Evans used to develop alternative asymmetric synthesis methods as a way to produce single stereoisomers. Evans started experimenting with organophosphorus chemistry in 1970, developing a process using phosphorus atoms of organophosphate compounds as agents to produce specific stereoisomers. He also devised a method of asymmetric synthesis to synthesize alpha-amino phosphonic acids by adding phosphorus to sulfimides.
At the University of North Carolina Evans assembled a research team of undergraduates, graduate students, and postdoctoral fellows from around the world. In the 1980s, a Ford Foundation Fellowship allowed him to create ties between his research team and a research group at the Paul Sabatier University in France, where he spent a full sabbatical year. Later, with the help of a Fulbright Fellowship, he built ties with groups in Mexico, Poland, Germany, Greece, and Russia.
Evans championed recruiting minority applicants to UNC-Chapel Hill, while on the national front, he served on committees of the American Chemical Society, the National Institutes of Health, the National Science Foundation, and was chair of the U.S. National Committee of the International Union of Pure and Applied Chemistry. He also served on a council that advised the National Institute of General Medical Sciences.
Selected publications
Awards and recognition
1994 — Tanner Award for Teaching Excellence
1995 — NSF Special Creativity Award in Organophosphorus Chemistry
1998 — ACS Award for Encouraging Disadvantaged Students into Careers in the Chemical Sciences
Chancellor's Award for Excellence in Undergraduate Education
Howard University Outstanding Achievement Award
Personal life
Evans married Tommie Johnson in 1967. They had two children. Evans died on March 24, 2001, in Chapel Hill. The Slayton A. Evans Jr. Memorial Lecture Fund and the Slayton Evans Research Award were both named in his honor post-humously.
References
1943 births
2001 deaths
20th-century American chemists
African-American chemists
Case Western Reserve University alumni
Dartmouth College faculty
Stereochemists
Tougaloo College alumni
University of North Carolina at Chapel Hill faculty
20th-century African-American scientists
Chemists from Illinois | Slayton A. Evans Jr. | [
"Chemistry"
] | 1,275 | [
"Stereochemistry",
"Stereochemists"
] |
64,324,611 | https://en.wikipedia.org/wiki/Gauge%20theory%20%28mathematics%29 | In mathematics, and especially differential geometry and mathematical physics, gauge theory is the general study of connections on vector bundles, principal bundles, and fibre bundles. Gauge theory in mathematics should not be confused with the closely related concept of a gauge theory in physics, which is a field theory that admits gauge symmetry. In mathematics theory means a mathematical theory, encapsulating the general study of a collection of concepts or phenomena, whereas in the physical sense a gauge theory is a mathematical model of some natural phenomenon.
Gauge theory in mathematics is typically concerned with the study of gauge-theoretic equations. These are differential equations involving connections on vector bundles or principal bundles, or involving sections of vector bundles, and so there are strong links between gauge theory and geometric analysis. These equations are often physically meaningful, corresponding to important concepts in quantum field theory or string theory, but also have important mathematical significance. For example, the Yang–Mills equations are a system of partial differential equations for a connection on a principal bundle, and in physics solutions to these equations correspond to vacuum solutions to the equations of motion for a classical field theory, particles known as instantons.
Gauge theory has found uses in constructing new invariants of smooth manifolds, the construction of exotic geometric structures such as hyperkähler manifolds, as well as giving alternative descriptions of important structures in algebraic geometry such as moduli spaces of vector bundles and coherent sheaves.
History
Gauge theory has its origins as far back as the formulation of Maxwell's equations describing classical electromagnetism, which may be phrased as a gauge theory with structure group the circle group. Work of Paul Dirac on magnetic monopoles and relativistic quantum mechanics encouraged the idea that bundles and connections were the correct way of phrasing many problems in quantum mechanics. Gauge theory in mathematical physics arose as a significant field of study with the seminal work of Robert Mills and Chen-Ning Yang on so-called Yang–Mills gauge theory, which is now the fundamental model that underpins the standard model of particle physics.
The mathematical investigation of gauge theory has its origins in the work of Michael Atiyah, Isadore Singer, and Nigel Hitchin on the self-duality equations on a Riemannian manifold in four dimensions. In this work the moduli space of self-dual connections (instantons) on Euclidean space was studied, and shown to be of dimension where is a positive integer parameter. This linked up with the discovery by physicists of BPST instantons, vacuum solutions to the Yang–Mills equations in four dimensions with . Such instantons are defined by a choice of 5 parameters, the center and scale , corresponding to the -dimensional moduli space. A BPST instanton is depicted to the right.
Around the same time Atiyah and Richard Ward discovered links between solutions to the self-duality equations and algebraic bundles over the complex projective space . Another significant early discovery was the development of the ADHM construction by Atiyah, Vladimir Drinfeld, Hitchin, and Yuri Manin. This construction allowed for the solution to the anti-self-duality equations on Euclidean space from purely linear algebraic data.
Significant breakthroughs encouraging the development of mathematical gauge theory occurred in the early 1980s. At this time the important work of Atiyah and Raoul Bott about the Yang–Mills equations over Riemann surfaces showed that gauge theoretic problems could give rise to interesting geometric structures, spurring the development of infinite-dimensional moment maps, equivariant Morse theory, and relations between gauge theory and algebraic geometry. Important analytical tools in geometric analysis were developed at this time by Karen Uhlenbeck, who studied the analytical properties of connections and curvature proving important compactness results. The most significant advancements in the field occurred due to the work of Simon Donaldson and Edward Witten.
Donaldson used a combination of algebraic geometry and geometric analysis techniques to construct new invariants of four manifolds, now known as Donaldson invariants. With these invariants, novel results such as the existence of topological manifolds admitting no smooth structures, or the existence of many distinct smooth structures on the Euclidean space could be proved. For this work Donaldson was awarded the Fields Medal in 1986.
Witten similarly observed the power of gauge theory to describe topological invariants, by relating quantities arising from Chern–Simons theory in three dimensions to the Jones polynomial, an invariant of knots. This work and the discovery of Donaldson invariants, as well as novel work of Andreas Floer on Floer homology, inspired the study of topological quantum field theory.
After the discovery of the power of gauge theory to define invariants of manifolds, the field of mathematical gauge theory expanded in popularity. Further invariants were discovered, such as Seiberg–Witten invariants and Vafa–Witten invariants. Strong links to algebraic geometry were realised by the work of Donaldson, Uhlenbeck, and Shing-Tung Yau on the Kobayashi–Hitchin correspondence relating Yang–Mills connections to stable vector bundles. Work of Nigel Hitchin and Carlos Simpson on Higgs bundles demonstrated that moduli spaces arising out of gauge theory could have exotic geometric structures such as that of hyperkähler manifolds, as well as links to integrable systems through the Hitchin system. Links to string theory and Mirror symmetry were realised, where gauge theory is essential to phrasing the homological mirror symmetry conjecture and the AdS/CFT correspondence.
Fundamental objects of interest
The fundamental objects of interest in gauge theory are connections on vector bundles and principal bundles. In this section we briefly recall these constructions, and refer to the main articles on them for details. The structures described here are standard within the differential geometry literature, and an introduction to the topic from a gauge-theoretic perspective can be found in the book of Donaldson and Peter Kronheimer.
Principal bundles
The central objects of study in gauge theory are principal bundles and vector bundles. The choice of which to study is essentially arbitrary, as one may pass between them, but principal bundles are the natural objects from the physical perspective to describe gauge fields, and mathematically they more elegantly encode the corresponding theory of connections and curvature for vector bundles associated to them.
A principal bundle with structure group , or a principal -bundle, consists of a quintuple where is a smooth fibre bundle with fibre space isomorphic to a Lie group , and represents a free and transitive right group action of on which preserves the fibres, in the sense that for all , for all . Here is the total space, and the base space. Using the right group action for each and any choice of , the map defines a diffeomorphism between the fibre over and the Lie group as smooth manifolds. Note however there is no natural way of equipping the fibres of with the structure of Lie groups, as there is no natural choice of element for every .
The simplest examples of principal bundles are given when is the circle group. In this case the principal bundle has dimension where . Another natural example occurs when is the frame bundle of the tangent bundle of the manifold , or more generally the frame bundle of a vector bundle over . In this case the fibre of is given by the general linear group .
Since a principal bundle is a fibre bundle, it locally has the structure of a product. That is, there exists an open covering of and diffeomorphisms commuting with the projections and , such that the transition functions defined by satisfy the cocycle condition
on any triple overlap . In order to define a principal bundle it is enough to specify such a choice of transition functions, The bundle is then defined by gluing trivial bundles along the intersections using the transition functions. The cocycle condition ensures precisely that this defines an equivalence relation on the disjoint union and therefore that the quotient space is well-defined. This is known as the fibre bundle construction theorem and the same process works for any fibre bundle described by transition functions, not just principal bundles or vector bundles.
Notice that a choice of local section satisfying is an equivalent method of specifying a local trivialisation map. Namely, one can define where is the unique group element such that .
Vector bundles
A vector bundle is a triple where is a fibre bundle with fibre given by a vector space where is a field. The number is the rank of the vector bundle. Again one has a local description of a vector bundle in terms of a trivialising open cover. If is such a cover, then under the isomorphism
one obtains distinguished local sections of corresponding to the coordinate basis vectors of , denoted . These are defined by the equation
To specify a trivialisation it is therefore equivalent to give a collection of local sections which are everywhere linearly independent, and use this expression to define the corresponding isomorphism. Such a collection of local sections is called a frame.
Similarly to principal bundles, one obtains transition functions for a vector bundle, defined by
If one takes these transition functions and uses them to construct the local trivialisation for a principal bundle with fibre equal to the structure group , one obtains exactly the frame bundle of , a principal -bundle.
Associated bundles
Given a principal -bundle and a representation of on a vector space , one can construct an associated vector bundle with fibre the vector space . To define this vector bundle, one considers the right action on the product defined by and defines as the quotient space with respect to this action.
In terms of transition functions the associated bundle can be understood more simply. If the principal bundle has transition functions with respect to a local trivialisation , then one constructs the associated vector bundle using the transition functions .
The associated bundle construction can be performed for any fibre space , not just a vector space, provided is a group homomorphism. One key example is the capital A adjoint bundle with fibre , constructed using the group homomorphism defined by conjugation . Note that despite having fibre , the Adjoint bundle is neither a principal bundle, or isomorphic as a fibre bundle to itself. For example, if is Abelian, then the conjugation action is trivial and will be the trivial -fibre bundle over regardless of whether or not is trivial as a fibre bundle. Another key example is the lowercase a adjoint bundle constructed using the adjoint representation where is the Lie algebra of .
Gauge transformations
A gauge transformation of a vector bundle or principal bundle is an automorphism of this object. For a principal bundle, a gauge transformation consists of a diffeomorphism commuting with the projection operator and the right action . For a vector bundle a gauge transformation is similarly defined by a diffeomorphism commuting with the projection operator which is a linear isomorphism of vector spaces on each fibre.
The gauge transformations (of or ) form a group under composition, called the gauge group, typically denoted . This group can be characterised as the space of global sections of the adjoint bundle, or in the case of a vector bundle, where denotes the frame bundle.
One can also define a local gauge transformation as a local bundle isomorphism over a trivialising open subset . This can be uniquely specified as a map (taking in the case of vector bundles), where the induced bundle isomorphism is defined by
and similarly for vector bundles.
Notice that given two local trivialisations of a principal bundle over the same open subset , the transition function is precisely a local gauge transformation . That is, local gauge transformations are changes of local trivialisation for principal bundles or vector bundles.
Connections on principal bundles
A connection on a principal bundle is a method of connecting nearby fibres so as to capture the notion of a section being constant or horizontal. Since the fibres of an abstract principal bundle are not naturally identified with each other, or indeed with the fibre space itself, there is no canonical way of specifying which sections are constant. A choice of local trivialisation leads to one possible choice, where if is trivial over a set , then a local section could be said to be horizontal if it is constant with respect to this trivialisation, in the sense that for all and one . In particular a trivial principal bundle comes equipped with a trivial connection.
In general a connection is given by a choice of horizontal subspaces of the tangent spaces at every point , such that at every point one has where is the vertical bundle defined by . These horizontal subspaces must be compatible with the principal bundle structure by requiring that the horizontal distribution is invariant under the right group action: where denotes right multiplication by . A section is said to be horizontal if where is identified with its image inside , which is a submanifold of with tangent bundle . Given a vector field , there is a unique horizontal lift . The curvature of the connection is given by the two-form with values in the adjoint bundle defined by
where is the Lie bracket of vector fields. Since the vertical bundle consists of the tangent spaces to the fibres of and these fibres are isomorphic to the Lie group whose tangent bundle is canonically identified with , there is a unique Lie algebra-valued two-form corresponding to the curvature. From the perspective of the Frobenius integrability theorem, the curvature measures precisely the extent to which the horizontal distribution fails to be integrable, and therefore the extent to which fails to embed inside as a horizontal submanifold locally.
The choice of horizontal subspaces may be equivalently expressed by a projection operator which is equivariant in the correct sense, called the connection one-form. For a horizontal distribution , this is defined by where denotes the decomposition of a tangent vector with respect to the direct sum decomposition . Due to the equivariance, this projection one-form may be taken to be Lie algebra-valued, giving some .
A local trivialisation for is equivalently given by a local section and the connection one-form and curvature can be pulled back along this smooth map. This gives the local connection one-form which takes values in the adjoint bundle of . Cartan's structure equation says that the curvature may be expressed in terms of the local one-form by the expression
where we use the Lie bracket on the Lie algebra bundle which is identified with on the local trivialisation .
Under a local gauge transformation so that , the local connection one-form transforms by the expression
where denotes the Maurer–Cartan form of the Lie group . In the case where is a matrix Lie group, one has the simpler expression
Connections on vector bundles
A connection on a vector bundle may be specified similarly to the case for principal bundles above, known as an Ehresmann connection. However vector bundle connections admit a more powerful description in terms of a differential operator. A connection on a vector bundle is a choice of -linear differential operator
such that
for all and sections . The covariant derivative of a section in the direction of a vector field is defined by
where on the right we use the natural pairing between and . This is a new section of the vector bundle , thought of as the derivative of in the direction of . The operator is the covariant derivative operator in the direction of . The curvature of is given by the operator with values in the endomorphism bundle, defined by
In a local trivialisation the exterior derivative acts as a trivial connection (corresponding in the principal bundle picture to the trivial connection discussed above). Namely for a local frame one defines
where here we have used Einstein notation for a local section .
Any two connections differ by an -valued one-form . To see this, observe that the difference of two connections is -linear:
In particular since every vector bundle admits a connection (using partitions of unity and the local trivial connections), the set of connections on a vector bundle has the structure of an infinite-dimensional affine space modelled on the vector space . This space is commonly denoted .
Applying this observation locally, every connection over a trivialising subset differs from the trivial connection by some local connection one-form , with the property that on . In terms of this local connection form, the curvature may be written as
where the wedge product occurs on the one-form component, and one composes endomorphisms on the endomorphism component. To link back to the theory of principal bundles, notice that where on the right we now perform wedge of one-forms and commutator of endomorphisms.
Under a gauge transformation of the vector bundle , a connection transforms into a connection by the conjugation . The difference where here is acting on the endomorphisms of . Under a local gauge transformation one obtains the same expression
as in the case of principal bundles.
Induced connections
A connection on a principal bundle induces connections on associated vector bundles. One way to see this is in terms of the local connection forms described above. Namely, if a principal bundle connection has local connection forms , and is a representation of defining an associated vector bundle , then the induced local connection one-forms are defined by
Here is the induced Lie algebra homomorphism from , and we use the fact that this map induces a homomorphism of vector bundles .
The induced curvature can be simply defined by
Here one sees how the local expressions for curvature are related for principal bundles and vector bundles, as the Lie bracket on the Lie algebra is sent to the commutator of endomorphisms of under the Lie algebra homomorphism .
Space of connections
The central object of study in mathematical gauge theory is the space of connections on a vector bundle or principal bundle. This is an infinite-dimensional affine space modelled on the vector space (or in the case of vector bundles). Two connections are said to be gauge equivalent if there exists a gauge transformation such that . Gauge theory is concerned with gauge equivalence classes of connections. In some sense gauge theory is therefore concerned with the properties of the quotient space , which is in general neither a Hausdorff space or a smooth manifold.
Many interesting properties of the base manifold can be encoded in the geometry and topology of moduli spaces of connections on principal bundles and vector bundles over . Invariants of , such as Donaldson invariants or Seiberg–Witten invariants can be obtained by computing numeral quantities derived from moduli spaces of connections over . The most famous application of this idea is Donaldson's theorem, which uses the moduli space of Yang–Mills connections on a principal -bundle over a simply connected four-manifold to study its intersection form. For this work Donaldson was awarded a Fields Medal.
Notational conventions
There are various notational conventions used for connections on vector bundles and principal bundles which will be summarised here.
The letter is the most common symbol used to represent a connection on a vector bundle or principal bundle. It comes from the fact that if one chooses a fixed connection of all connections, then any other connection may be written for some unique one-form . It also comes from the use of to denote the local form of the connection on a vector bundle, which subsequently comes from the electromagnetic potential in physics. Sometimes the symbol is also used to refer to the connection form, usually on a principal bundle, and usually in this case refers to the global connection one-form on the total space of the principal bundle, rather than the corresponding local connections forms. This convention is usually avoided in the mathematical literature as it often clashes with the use of for a Kähler form when the underlying manifold is a Kähler manifold.
The symbol is most commonly used to represent a connection on a vector bundle as a differential operator, and in that sense is used interchangeably with the letter . It is also used to refer to the covariant derivative operators . Alternative notation for the connection operator and covariant derivative operators is to emphasize the dependence on the choice of , or or .
The operator most commonly refers to the exterior covariant derivative of a connection (and so is sometimes written for a connection ). Since the exterior covariant derivative in degree 0 is the same as the regular covariant derivative, the connection or covariant derivative itself is often denoted instead of .
The symbol or is most commonly used to refer to the curvature of a connection. When the connection is referred to by , the curvature is referred to by rather than . Other conventions involve or or , by analogy with the Riemannian curvature tensor in Riemannian geometry which is denoted by .
The letter is often used to denote a principal bundle connection or Ehresmann connection when emphasis is to be placed on the horizontal distribution . In this case the vertical projection operator corresponding to (the connection one-form on ) is usually denoted , or , or . Using this convention the curvature is sometimes denoted to emphasize the dependence, and may refer to either the curvature operator on the total space , or the curvature on the base .
The Lie algebra adjoint bundle is usually denoted , and the Lie group adjoint bundle by . This disagrees with the convention in the theory of Lie groups, where refers to the representation of on , and refers to the Lie algebra representation of on itself by the Lie bracket. In the Lie group theory the conjugation action (which defines the bundle ) is often denoted by .
Dictionary of mathematical and physical terminology
The mathematical and physical fields of gauge theory involve the study of the same objects, but use different terminology to describe them. Below is a summary of how these terms relate to each other.
As a demonstration of this dictionary, consider an interacting term of an electron-positron particle field and the electromagnetic field in the Lagrangian of quantum electrodynamics:
Mathematically this might be rewritten
where is a connection on a principal bundle , is a section of an associated spinor bundle and is the induced Dirac operator of the induced covariant derivative on this associated bundle. The first term is an interacting term in the Lagrangian between the spinor field (the field representing the electron-positron) and the gauge field (representing the electromagnetic field). The second term is the regular Yang–Mills functional which describes the basic non-interacting properties of the electromagnetic field (the connection ). The term of the form is an example of what in physics is called minimal coupling, that is, the simplest possible interaction between a matter field and a gauge field .
Yang–Mills theory
The predominant theory that occurs in mathematical gauge theory is Yang–Mills theory. This theory involves the study of connections which are critical points of the Yang–Mills functional defined by
where is an oriented Riemannian manifold with the Riemannian volume form and an -norm on the adjoint bundle . This functional is the square of the -norm of the curvature of the connection , so connections which are critical points of this function are those with curvature as small as possible (or higher local minima of ).
These critical points are characterised as solutions of the associated Euler–Lagrange equations, the Yang–Mills equations
where is the induced exterior covariant derivative of on and is the Hodge star operator. Such solutions are called Yang–Mills connections and are of significant geometric interest.
The Bianchi identity asserts that for any connection, . By analogy for differential forms a harmonic form is characterised by the condition
If one defined a harmonic connection by the condition that
the then study of Yang–Mills connections is similar in nature to that of harmonic forms. Hodge theory provides a unique harmonic representative of every de Rham cohomology class . Replacing a cohomology class by a gauge orbit , the study of Yang–Mills connections can be seen as trying to find unique representatives for each orbit in the quotient space of connections modulo gauge transformations.
Self-duality and anti-self-duality equations
In dimension four the Hodge star operator sends two-forms to two-forms, , and squares to the identity operator, . Thus the Hodge star operating on two-forms has eigenvalues , and the two-forms on an oriented Riemannian four-manifold split as a direct sum
into the self-dual and anti-self-dual two-forms, given by the and eigenspaces of the Hodge star operator respectively. That is, is self-dual if , and anti-self dual if , and every differential two-form admits a splitting into self-dual and anti-self-dual parts.
If the curvature of a connection on a principal bundle over a four-manifold is self-dual or anti-self-dual then by the Bianchi identity , so the connection is automatically a Yang–Mills connection. The equation
is a first order partial differential equation for the connection , and therefore is simpler to study than the full second order Yang–Mills equation. The equation is called the self-duality equation, and the equation is called the anti-self-duality equation, and solutions to these equations are self-dual connections or anti-self-dual connections respectively.
Dimensional reduction
One way to derive new and interesting gauge-theoretic equations is to apply the process of dimensional reduction to the Yang–Mills equations. This process involves taking the Yang–Mills equations over a manifold (usually taken to be the Euclidean space ), and imposing that the solutions of the equations be invariant under a group of translational or other symmetries. Through this process the Yang–Mills equations lead to the Bogomolny equations describing monopoles on , Hitchin's equations describing Higgs bundles on Riemann surfaces, and the Nahm equations on real intervals, by imposing symmetry under translations in one, two, and three directions respectively.
Gauge theory in one and two dimensions
Here the Yang–Mills equations when the base manifold is of low dimension is discussed. In this setting the equations simplify dramatically due to the fact that in dimension one there are no two-forms, and in dimension two the Hodge star operator on two-forms acts as .
Yang–Mills theory
One may study the Yang–Mills equations directly on a manifold of dimension two. The theory of Yang–Mills equations when the base manifold is a compact Riemann surface was carried about by Michael Atiyah and Raoul Bott. In this case the moduli space of Yang–Mills connections over a complex vector bundle admits various rich interpretations, and the theory serves as the simplest case to understand the equations in higher dimensions. The Yang–Mills equations in this case become
for some topological constant depending on . Such connections are called projectively flat, and in the case where the vector bundle is topologically trivial (so ) they are precisely the flat connections.
When the rank and degree of the vector bundle are coprime, the moduli space of Yang–Mills connections is smooth and has a natural structure of a symplectic manifold. Atiyah and Bott observed that since the Yang–Mills connections are projectively flat, their holonomy gives projective unitary representations of the fundamental group of the surface, so that this space has an equivalent description as a moduli space of projective unitary representations of the fundamental group of the Riemann surface, a character variety. The theorem of Narasimhan and Seshadri gives an alternative description of this space of representations as the moduli space of stable holomorphic vector bundles which are smoothly isomorphic to the . Through this isomorphism the moduli space of Yang–Mills connections gains a complex structure, which interacts with the symplectic structure of Atiyah and Bott to make it a compact Kähler manifold.
Simon Donaldson gave an alternative proof of the theorem of Narasimhan and Seshadri that directly passed from Yang–Mills connections to stable holomorphic structures. Atiyah and Bott used this rephrasing of the problem to illuminate the intimate relationship between the extremal Yang–Mills connections and the stability of the vector bundles, as an infinite-dimensional moment map for the action of the gauge group , given by the curvature map itself. This observation phrases the Narasimhan–Seshadri theorem as a kind of infinite-dimensional version of the Kempf–Ness theorem from geometric invariant theory, relating critical points of the norm squared of the moment map (in this case Yang–Mills connections) to stable points on the corresponding algebraic quotient (in this case stable holomorphic vector bundles). This idea has been subsequently very influential in gauge theory and complex geometry since its introduction.
Nahm equations
The Nahm equations, introduced by Werner Nahm, are obtained as the dimensional reduction of the anti-self-duality in four dimensions to one dimension, by imposing translational invariance in three directions. Concretely, one requires that the connection form does not depend on the coordinates . In this setting the Nahm equations between a system of equations on an interval for four matrices satisfying the triple of equations
It was shown by Nahm that the solutions to these equations (which can be obtained fairly easily as they are a system of ordinary differential equations) can be used to construct solutions to the Bogomolny equations, which describe monopoles on . Nigel Hitchin showed that solutions to the Bogomolny equations could be used to construct solutions to the Nahm equations, showing solutions to the two problems were equivalent. Donaldson further showed that solutions to the Nahm equations are equivalent to rational maps of degree from the complex projective line to itself, where is the charge of the corresponding magnetic monopole.
The moduli space of solutions to the Nahm equations has the structure of a hyperkähler manifold.
Hitchin's equations and Higgs bundles
Hitchin's equations, introduced by Nigel Hitchin, are obtained as the dimensional reduction of the self-duality equations in four dimensions to two dimensions by imposing translation invariance in two directions. In this setting the two extra connection form components can be combined into a single complex-valued endomorphism , and when phrased in this way the equations become conformally invariant and therefore are natural to study on a compact Riemann surface rather than . Hitchin's equations state that for a pair on a complex vector bundle where , that
where is the -component of . Solutions of Hitchin's equations are called Hitchin pairs.
Whereas solutions to the Yang–Mills equations on a compact Riemann surface correspond to projective unitary representations of the surface group, Hitchin showed that solutions to Hitchin's equations correspond to projective complex representations of the surface group. The moduli space of Hitchin pairs naturally has (when the rank and degree of the bundle are coprime) the structure of a Kähler manifold. Through an analogue of Atiyah and Bott's observation about the Yang–Mills equations, Hitchin showed that Hitchin pairs correspond to so-called stable Higgs bundles, where a Higgs bundle is a pair where is a holomorphic vector bundle and is a holomorphic endomorphism of with values in the canonical bundle of the Riemann surface . This is shown through an infinite-dimensional moment map construction, and this moduli space of Higgs bundles also has a complex structure, which is different to that coming from the Hitchin pairs, leading to two complex structures on the moduli space of Higgs bundles. These combine to give a third making this moduli space a hyperkähler manifold.
Hitchin's work was subsequently vastly generalised by Carlos Simpson, and the correspondence between solutions to Hitchin's equations and Higgs bundles over an arbitrary Kähler manifold is known as the nonabelian Hodge theorem.
Gauge theory in three dimensions
Monopoles
The dimensional reduction of the Yang–Mills equations to three dimensions by imposing translational invariance in one direction gives rise to the Bogomolny equations for a pair where is a family of matrices. The equations are
When the principal bundle has structure group the circle group, solutions to the Bogomolny equations model the Dirac monopole describing a magnetic monopole in classical electromagnetism. The work of Nahm and Hitchin shows that when the structure group is the special unitary group solutions to the monopole equations correspond to solutions to the Nahm equations, and by work of Donaldson these further correspond to rational maps from to itself of degree where is the charge of the monopole. This charge is defined as the limit
of the integral of the pairing over spheres in of increasing radius .
Chern–Simons theory
Chern–Simons theory in 3 dimensions is a topological quantum field theory with an action functional proportional to the integral of the Chern–Simons form, a three-form defined by
Classical solutions to the Euler–Lagrange equations of the Chern–Simons functional on a closed 3-manifold correspond to flat connections on the principal -bundle . However, when has a boundary the situation becomes more complicated. Chern–Simons theory was used by Edward Witten to express the Jones polynomial, a knot invariant, in terms of the vacuum expectation value of a Wilson loop in Chern–Simons theory on the three-sphere . This was a stark demonstration of the power of gauge theoretic problems to provide new insight in topology, and was one of the first instances of a topological quantum field theory.
In the quantization of the classical Chern–Simons theory, one studies the induced flat or projectively flat connections on the principal bundle restricted to surfaces inside the 3-manifold. The classical state spaces corresponding to each surface are precisely the moduli spaces of Yang–Mills equations studied by Atiyah and Bott. The geometric quantization of these spaces was achieved by Nigel Hitchin and Axelrod–Della Pietra–Witten independently, and in the case where the structure group is complex, the configuration space is the moduli space of Higgs bundles and its quantization was achieved by Witten.
Floer homology
Andreas Floer introduced a type of homology on a 3-manifolds defined in analogy with Morse homology in finite dimensions. In this homology theory, the Morse function is the Chern–Simons functional on the space of connections on an principal bundle over the 3-manifold . The critical points are the flat connections, and the flow lines are defined to be the Yang–Mills instantons on that restrict to the critical flat connections on the two boundary components. This leads to instanton Floer homology. The Atiyah–Floer conjecture asserts that instanton Floer homology agrees with the Lagrangian intersection Floer homology of the moduli space of flat connections on the surface defining a Heegaard splitting of , which is symplectic due to the observations of Atiyah and Bott.
In analogy with instanton Floer homology one may define Seiberg–Witten Floer homology where instantons are replaced with solutions of the Seiberg–Witten equations. By work of Clifford Taubes this is known to be isomorphic to embedded contact homology and subsequently Heegaard Floer homology.
Gauge theory in four dimensions
Gauge theory has been most intensively studied in four dimensions. Here the mathematical study of gauge theory overlaps significantly with its physical origins, as the standard model of particle physics can be thought of as a quantum field theory on a four-dimensional spacetime. The study of gauge theory problems in four dimensions naturally leads to the study of topological quantum field theory. Such theories are physical gauge theories that are insensitive to changes in the Riemannian metric of the underlying four-manifold, and therefore can be used to define topological (or smooth structure) invariants of the manifold.
Anti-self-duality equations
In four dimensions the Yang–Mills equations admit a simplification to the first order anti-self-duality equations for a connection on a principal bundle over an oriented Riemannian four-manifold . These solutions to the Yang–Mills equations represent the absolute minima of the Yang–Mills functional, and the higher critical points correspond to the solutions that do not arise from anti-self-dual connections. The moduli space of solutions to the anti-self-duality equations, , allows one to derive useful invariants about the underlying four-manifold.
This theory is most effective in the case where is simply connected. For example, in this case Donaldson's theorem asserts that if the four-manifold has negative-definite intersection form (4-manifold), and if the principal bundle has structure group the special unitary group and second Chern class , then the moduli space is five-dimensional and gives a cobordism between itself and a disjoint union of copies of with its orientation reversed. This implies that the intersection form of such a four-manifold is diagonalisable. There are examples of simply connected topological four-manifolds with non-diagonalisable intersection form, such as the E8 manifold, so Donaldson's theorem implies the existence of topological four-manifolds with no smooth structure. This is in stark contrast with two or three dimensions, in which topological structures and smooth structures are equivalent: any topological manifold of dimension less than or equal to 3 has a unique smooth structure on it.
Similar techniques were used by Clifford Taubes and Donaldson to show that Euclidean space admits uncountably infinitely many distinct smooth structures. This is in stark contrast to any dimension other than four, where Euclidean space has a unique smooth structure.
An extension of these ideas leads to Donaldson theory, which constructs further invariants of smooth four-manifolds out of the moduli spaces of connections over them. These invariants are obtained by evaluating cohomology classes on the moduli space against a fundamental class, which exists due to analytical work showing the orientability and compactness of the moduli space by Karen Uhlenbeck, Taubes, and Donaldson.
When the four-manifold is a Kähler manifold or algebraic surface and the principal bundle has vanishing first Chern class, the anti-self-duality equations are equivalent to the Hermitian Yang–Mills equations on the complex manifold . The Kobayashi–Hitchin correspondence proven for algebraic surfaces by Donaldson, and in general by Uhlenbeck and Yau, asserts that solutions to the HYM equations correspond to stable holomorphic vector bundles. This work gave an alternate algebraic description of the moduli space and its compactification, because the moduli space of semistable holomorphic vector bundles over a complex manifold is a projective variety, and therefore compact. This indicates one way of compactifying the moduli space of connections is to add in connections corresponding to semi-stable vector bundles, so-called almost Hermitian Yang–Mills connections.
Seiberg–Witten equations
During their investigation of supersymmetry in four dimensions, Edward Witten and Nathan Seiberg uncovered a system of equations now called the Seiberg–Witten equations, for a connection and spinor field . In this case the four-manifold must admit a SpinC structure, which defines a principal SpinC bundle with determinant line bundle , and an associated spinor bundle . The connection is on , and the spinor field . The Seiberg–Witten equations are given by
Solutions to the Seiberg–Witten equations are called monopoles. The moduli space of solutions to the Seiberg–Witten equations, where denotes the choice of Spin structure, is used to derive the Seiberg–Witten invariants. The Seiberg–Witten equations have an advantage over the anti-self-duality equations, in that the equations themselves may be perturbed slightly to give the moduli space of solutions better properties. To do this, an arbitrary self-dual two-form is added on to the first equation. For generic choices of metric on the underlying four-manifold, and choice of perturbing two-form, the moduli space of solutions is a compact smooth manifold. In good circumstances (when the manifold is of simple type), this moduli space is zero-dimensional: a finite collection of points. The Seiberg–Witten invariant in this case is simply the number of points in the moduli space. The Seiberg–Witten invariants can be used to prove many of the same results as Donaldson invariants, but often with easier proofs which apply in more generality.
Gauge theory in higher dimensions
Hermitian Yang–Mills equations
A particular class of Yang–Mills connections are possible to study over Kähler manifolds or Hermitian manifolds. The Hermitian Yang–Mills equations generalise the anti-self-duality equations occurring in four-dimensional Yang–Mills theory to holomorphic vector bundles over Hermitian complex manifolds in any dimension. If is a holomorphic vector bundle over a compact Kähler manifold , and is a Hermitian connection on with respect to some Hermitian metric . The Hermitian Yang–Mills equations are
where is a topological constant depending on . These may be viewed either as an equation for the Hermitian connection or for the corresponding Hermitian metric with associated Chern connection . In four dimensions the HYM equations are equivalent to the ASD equations. In two dimensions the HYM equations correspond to the Yang–Mills equations considered by Atiyah and Bott. The Kobayashi–Hitchin correspondence asserts that solutions of the HYM equations are in correspondence with polystable holomorphic vector bundles. In the case of compact Riemann surfaces this is the theorem of Narasimhan and Seshadri as proven by Donaldson. For algebraic surfaces it was proven by Donaldson, and in general it was proven by Karen Uhlenbeck and Shing-Tung Yau. This theorem is generalised in the nonabelian Hodge theorem by Simpson, and is in fact a special case of it where the Higgs field of a Higgs bundle is set to zero.
Exceptional holonomy instantons
The effectiveness of solutions of the Yang–Mills equations in defining invariants of four-manifolds has led to interest that they may help distinguish between exceptional holonomy manifolds such as G2 manifolds in dimension 7 and Spin(7) manifolds in dimension 8, as well as related structures such as Calabi–Yau 6-manifolds and nearly Kähler manifolds.
String theory
New gauge-theoretic problems arise out of superstring theory models. In such models the universe is 10 dimensional consisting of four dimensions of regular spacetime and a 6-dimensional Calabi–Yau manifold. In such theories the fields which act on strings live on bundles over these higher dimensional spaces, and one is interested in gauge-theoretic problems relating to them. For example, the limit of the natural field theories in superstring theory as the string radius approaches zero (the so-called large volume limit) on a Calabi–Yau 6-fold is given by Hermitian Yang–Mills equations on this manifold. Moving away from the large volume limit one obtains the deformed Hermitian Yang–Mills equation, which describes the equations of motion for a D-brane in the B-model of superstring theory. Mirror symmetry predicts that solutions to these equations should correspond to special Lagrangian submanifolds of the mirror dual Calabi–Yau.
See also
Gauge theory
Introduction to gauge theory
Gauge group (mathematics)
Gauge symmetry (mathematics)
Yang–Mills theory
Yang–Mills equations
References
Differential geometry
Mathematical physics | Gauge theory (mathematics) | [
"Physics",
"Mathematics"
] | 8,831 | [
"Applied mathematics",
"Theoretical physics",
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64,325,880 | https://en.wikipedia.org/wiki/Galilei-covariant%20tensor%20formulation | The Galilei-covariant tensor formulation is a method for treating non-relativistic physics using the extended Galilei group as the representation group of the theory. It is constructed in the light cone of a five dimensional manifold.
Takahashi et al., in 1988, began a study of Galilean symmetry, where an explicitly covariant non-relativistic field theory could be developed. The theory is constructed in the light cone of a (4,1) Minkowski space. Previously, in 1985, Duval et al. constructed a similar tensor formulation in the context of Newton–Cartan theory. Some other authors also have developed a similar Galilean tensor formalism.
Galilean manifold
The Galilei transformations are
where stands for the three-dimensional Euclidean rotations, is the relative velocity determining Galilean boosts, a stands for spatial translations and b, for time translations. Consider a free mass particle ; the mass shell relation is given by .
We can then define a 5-vector,
,
with .
Thus, we can define a scalar product of the type
where
is the metric of the space-time, and .
Extended Galilei algebra
A five dimensional Poincaré algebra leaves the metric invariant,
We can write the generators as
The non-vanishing commutation relations will then be rewritten as
An important Lie subalgebra is
is the generator of time translations (Hamiltonian), Pi is the generator of spatial translations (momentum operator), is the generator of Galilean boosts, and stands for a generator of rotations (angular momentum operator). The generator is a Casimir invariant and is an additional Casimir invariant. This algebra is isomorphic to the extended Galilean Algebra in (3+1) dimensions with , The central charge, interpreted as mass, and .
The third Casimir invariant is given by , where is a 5-dimensional analog of the Pauli–Lubanski pseudovector.
Bargmann structures
In 1985 Duval, Burdet and Kunzle showed that four-dimensional Newton–Cartan theory of gravitation can be reformulated as Kaluza–Klein reduction of five-dimensional Einstein gravity along a null-like direction. The metric used is the same as the Galilean metric but with all positive entries
This lifting is considered to be useful for non-relativistic holographic models. Gravitational models in this framework have been shown to precisely calculate the Mercury precession.
See also
Galilean group
Representation theory of the Galilean group
Lorentz group
Poincaré group
Pauli–Lubanski pseudovector
References
Rotational symmetry
Quantum mechanics
Representation theory of Lie groups | Galilei-covariant tensor formulation | [
"Physics"
] | 549 | [
"Theoretical physics",
"Quantum mechanics",
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64,326,265 | https://en.wikipedia.org/wiki/Bunker%20quantity%20survey | A bunker quantity survey (BQS), also known as a bunker quantity audit or simply a bunker survey, is a quantitative examination and assessment of fuel oil (bunker fuel) transferred from one party to another.
In the maritime industry, a BQS is conducted when a supply vessel (typically a bunker barge or shore tank) delivers fuel oil to a recipient vessel (typically a commercial marine vessel) as an audit to the transaction between the buyer and the seller. Alternatively, in certain cases, a BQS may also be conducted when the buyer/seller roles are reversed, as seen with "debunkering" operations, for example.
A BQS is a commonly used loss control tool to track significant variances of cargo quantities between the supplier and receiver. Since bunker fuel is often the largest financial cost driver to the operation of a vessel, a BQS is considered a critical service to ensure correct quantities of fuel are delivered.
Purpose
Due to the dynamic location of vessels, particularly those involved in maritime transport, the physical transfer of fuel (bunkering) often takes place thousands of miles from each party's contracting offices. As such, neither the buyer nor seller is usually present to witness the physical transfer and procedures involved, thus any quantity or procedural dispute is often futile and inconclusive. When such disputes arise, they can create unnecessary protests, legal fees, demurrage, loss of management time, and loss of good will for all stakeholders. A BQS performed by an impartial party can alleviate many of the stressors involved in the purchase and sale of bunker fuel, and ensure both parties are treated fairly from a financial standpoint.
Methods
While the specific methods of measuring liquid hydrocarbons, and subsequently a BQS, can vary based on circumstances such as location, available equipment, and accessibility, the general principals converge to certain key procedures. While each BQS provider may vary within the methodology, the underlying procedures typically involve measuring the cargo volumes and temperatures on both the supplying and receiving vessels before and after the cargo transfer.
Assessments
Quantitative
Quantitative assessments in bunker quantity surveys involve physical, measurable, and quantifiable variables of bunker fuel and delivery. These aspects revolve around temperature, density, volume, and their respective methods of calculation. The quantitative assessment of fuel quantity audits and surveys are typically what one would expect from a BQS, as such variables can be both physically measured and independently verified. Most BQS services focus primarily, and often exclusively, on the quantitative aspects, as they focus on the general principles of thermodynamics and follow international standardized methods, thus can often be referenced without protest by both parties.
Qualitative
As a relatively newer method in quantity based surveys, qualitative assessments in BQS focus more on the conditional and dependent aspects of each operation. Such methods focus on human error, local regulations and procedures, and financial cost drivers and ratios. These methods are often used in conjunction with the quantitative assessments mentioned earlier to provide a more holistic survey as opposed to a strict quantity inspection. Qualitative assessments are used primarily when the BQS is requested by one party only (as opposed to both), and focus on reducing operational costs for the client.
Importance
While a BQS is not always a legal requirement when taking bunker fuel, the service plays an important role in managing the continuity of relationships between fuel suppliers and consumers. Depending on where the fuel transfer operation takes place, different global ports have varying concerns when pertaining to the quantity of fuel delivered. While out right pilferage may be a common practice in some ports, thus citing an essential need for a BQS, procedural concerns may also warrant a BQS in ports where pilferage is not as common. Regardless of specific operational needs, BQS services are typically held in high regard as the cost to perform the surveys are often a small and insignificant cost relative to the overall cost of the fuel.
References
Petroleum
Shipping | Bunker quantity survey | [
"Chemistry"
] | 810 | [
"Petroleum",
"Chemical mixtures"
] |
64,326,647 | https://en.wikipedia.org/wiki/Chloride%20sulfite | A chloride sulfite or sulfite chloride is a chemical compound that contains chloride and sulfite anions (SO32− Cl−). The known compounds of this type are all late transition metal sulfito complexes. Chlorine may be present as a ligand (chloro) or as an ion (chloride). The sulfito ligand can connect to the metal atom by way of an oxygen, or a sulfur atom. It can also link to the metal atom using two oxygen atoms as a bidentate ligand.
Chloride sulfites are not to be confused with the chlorosulfites, which are compounds containing the SO2Cl− ion or -SO2Cl group in organic compounds, where it is also called chlorosulfinate. The chlorosulfates also have the formula SO3Cl− as a single ion, whereas chloride sulfites have three negative charges.
The mercury complex with formula ClHgSO3− is found in the acid gas scrubbers that purify pollution from smokestacks. However it decomposes and does not capture mercury in this application. This complex can form an ammonium salt: ammonium chlorosulfitomercurate(II) NH4[ClHgSO3], which decomposes over 130°C. The salt is formed from mercuric chloride and ammonium sulfite water solutions.
List
References
Transition metal compounds
Sulfites
Chlorides | Chloride sulfite | [
"Chemistry"
] | 299 | [
"Chlorides",
"Inorganic compounds",
"Salts"
] |
64,329,231 | https://en.wikipedia.org/wiki/Beet%20pseudoyellows%20virus | Beet pseudoyellows virus (BPYV) is a species of virus in the genus Crinivirus.
The virus was first recognised by James E. Duffus of the United States Department of Agriculture, and reported in 1975 under the title 'A new type of whitefly-transmitted disease – a link to the aphid-transmitted viruses'. Beet (Beta vulgaris) in a research greenhouse unexpectedly presented symptoms characteristic of the aphid-vectored virus Beet yellows virus, despite no aphids being present. Instead, greenhouse whiteflies (Trialeurodes vaporariorum) were present and determined to be the vector. The presumed new species of virus was designated 'Beet pseudo-yellows virus' (note the hyphen, omitted in the currently accepted name). Further investigation revealed the virus typically causes stunting, interveinal yellowing, and/or chlorotic spotting in its hosts, and that at least an additional 36 species of plants from various families are susceptible to infection.
Images
References
External links
Image and general information at Seminis
Images at Texas A&M AgriLife Extension
Rfam entry for 3'-terminal pseudoknot of BPYV
Crinivirus | Beet pseudoyellows virus | [
"Biology"
] | 249 | [
"Virus stubs",
"Viruses"
] |
64,330,536 | https://en.wikipedia.org/wiki/Uoma%20Beauty | Uoma Beauty is an American beauty company founded by Nigerian-born Sharon Chuter. Headquartered in Los Angeles, the company focuses on inclusive beauty. In 2019, the company launched 108 products for the face, lips and eyes, including fifty-one shades of foundation in six custom formulas, at ULTA Beauty stores around the country.
History
In late April 2019, Sharon Chuter launched a collection of 108 products with Uoma Beauty. Chuter moved the headquarters from London to Los Angeles.
Uoma was inspired by the Igbo word OMA, meaning beautiful. Sharon Chuter said, “The U in front is shortened from Umu – So it should be umu-oma which means beautiful people, but it’s such a long word and hard to brand so we went with UOMA...".
After an e-commerce launch, the brand appeared at ULTA Beauty and Selfridges after Chuter met representatives of the stores at a conference and via a friend respectively. During the Coronavirus pandemic in 2020, the company took part in the BeautyUnited campaign which focused on supporting front-line workers.
During the George Floyd protests in 2020, Chuter created an initiative called "Pull Up for Change" and coupled it with the hashtag #pulluporshutup on social media. The challenge was for other beauty brands to release the exact number of Black employees at their companies on the corporate and executive level, instead of just piggybacking off a trending hashtag. Since the challenge was released brands such as Kylie Cosmetics, ULTA, L'Oreal and Sephora have released demographic data on their employees and executives. The challenge has also ventured outside of the beauty industry, publishing lists from Facebook Google, Netflix, etc.
In May 2023, Sharon Chuter stepped down as CEO of Uoma Beauty and announced Cyndi Isgrig, former president of Dermstore, would serve as interim CEO.
Collaborations
For the launch of the "Black Magical Carnival Collection", the company partnered Jackie Aina and Patrick Starrr to promote it.
References
Cosmetics
English brands
Cosmetics companies of the United States
Beauty stores
Cosmetics brands
History of cosmetics
Companies based in Los Angeles
American companies established in 2019
E-commerce | Uoma Beauty | [
"Technology"
] | 455 | [
"Information technology",
"E-commerce"
] |
64,332,082 | https://en.wikipedia.org/wiki/2-Methoxyestriol | 2-Methoxyestriol (2-MeO-E3) is an endogenous estrogen metabolite. It is specifically a metabolite of estriol and 2-hydroxyestriol. It has negligible affinity for the estrogen receptors and no estrogenic activity. However, 2-methoxyestriol does have some non-estrogen receptor-mediated cholesterol-lowering effects.
See also
2-Methoxyestradiol
2-Methoxyestrone
4-Methoxyestradiol
4-Methoxyestrone
References
Estranes
Ethers
Hypolipidemic agents
Human metabolites
Hydroxyarenes
Sterols | 2-Methoxyestriol | [
"Chemistry"
] | 151 | [
"Organic compounds",
"Functional groups",
"Ethers"
] |
64,332,252 | https://en.wikipedia.org/wiki/2-Methoxyestradiol%20disulfamate | 2-Methoxyestradiol disulfamate (developmental code STX-140; also known as 2-methoxyestradiol 3,17β-O,O-bis(sulfamate)) is a synthetic, oral active anti-cancer medication which was previously under development for potential clinical use. It has improved potency, low metabolism, and good pharmacokinetic properties relative to 2-methoxyestradiol (2-MeO-E2). It is also a potent inhibitor of steroid sulfatase, the enzyme that catalyzes the desulfation of steroids such as estrone sulfate and dehydroepiandrosterone sulfate (DHEA-S).
2-Methoxyestradiol disulfamate exhibits anti-angiogenic activity and induction of cell cycle arrest and apoptosis in human tumor xenografts, with clinical potential for hormone–independent tumors. Some of this activity stems from tubulin binding at the colchicine site and disruption of interphase microtubules. 2-Methoxyestradiol disulfamate is highly active in tumors that are resistant to chemotherapy.
In xenograft models of breast and prostate cancer complete cures were achieved after oral treatment with 2-methoxyestradiol disulfamate and drug-resistant tumors also shrank in size after oral treatment. Conventional treatments for hormone-independent cancers targeting tubulin are associated with side effects, such as neurotoxicity, and can only be given infrequently and intravenously. 2-Methoxyestradiol disulfamate is more effective on the same tumors, blocks metastatic spread without the peripheral neuropathy associated with current clinical anticancer drugs.
See also
Steroid sulfatase § Inhibitors
References
Abandoned drugs
Angiogenesis inhibitors
Antineoplastic drugs
Estranes
Ethers
Human metabolites
Microtubule inhibitors
Steroid sulfatase inhibitors | 2-Methoxyestradiol disulfamate | [
"Chemistry",
"Biology"
] | 413 | [
"Angiogenesis",
"Drug safety",
"Functional groups",
"Organic compounds",
"Angiogenesis inhibitors",
"Ethers",
"Abandoned drugs"
] |
64,332,510 | https://en.wikipedia.org/wiki/4-Fluoroestradiol | 4-Fluoroestradiol (4-FE2) is a synthetic estrogen and a derivative of estradiol which was never marketed. It is specifically the 4-fluoro analogue of estradiol. 4-Fluoroestradiol has 180 ± 43% of the affinity of estradiol for the estrogen receptor of rat uterine cytosol and shows potent uterotrophic activity similar to that of estradiol in mice and rats. It has been labeled with fluorine-18 (18F) for potential use in medical imaging.
See also
16α-Fluoroestradiol
References
Abandoned drugs
Secondary alcohols
Estranes
Fluoroarenes
Hydroxyarenes
Synthetic estrogens | 4-Fluoroestradiol | [
"Chemistry"
] | 149 | [
"Drug safety",
"Abandoned drugs"
] |
64,332,676 | https://en.wikipedia.org/wiki/4-Methoxyestriol | 4-Methoxyestriol (4-MeO-E3) is an endogenous estrogen metabolite. It is the 4-methyl ether of 4-hydroxyestriol and a metabolite of estriol and 4-hydroxyestriol. 4-Methoxyestriol has very low affinities for the estrogen receptors. Its relative binding affinities (RBAs) for estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) are both about 1% of those of estradiol. For comparison, estriol had RBAs of 11% and 35%, respectively.
See also
2-Methoxyestradiol
2-Methoxyestriol
2-Methoxyestrone
4-Methoxyestradiol
4-Methoxyestrone
References
Estranes
Ethers
Human metabolites
Hydroxyarenes | 4-Methoxyestriol | [
"Chemistry"
] | 195 | [
"Organic compounds",
"Functional groups",
"Ethers"
] |
64,333,437 | https://en.wikipedia.org/wiki/Mac%20transition%20to%20Apple%20silicon | The Mac transition to Apple silicon was the process of switching the central processing units (CPUs) of Apple's line of Mac computers from Intel's x86-64 processors to Apple-designed Apple silicon ARM64 processors.
Apple CEO Tim Cook announced a "two-year transition plan" to Apple silicon on June 22, 2020. The first Macs with Apple-designed systems on a chip were released that November; the last, the Mac Pro, was released in June 2023, completing the transition in three years.
The transition was the third time Apple had switched the Macintosh to a new instruction set architecture. The first was from the Motorola 68000 series to PowerPC chips in 1994, and the second was from PowerPC to Intel processors using the x86 architecture in 2006.
Background
The first Mac, introduced in 1984, was the original Macintosh, which was based on the Motorola 68000 architecture. Apple evaluated several possibilities for different processors in the early 1990s, switching in 1994 to the PowerPC family that was co-developed by Apple, IBM, and Motorola. In 2005, it switched again to Intel 32-bit and 64-bit x86. In 2011, Mac OS X Lion dropped support for Macs with 32-bit processors; in 2019, macOS Catalina dropped support for 32-bit Intel apps. Supported 64-bit Intel systems can still boot the latest versions of macOS .
The genesis of the third switch began in 1985, when Acorn's ARM architecture was spotted by Apple's Advanced Technology Group (ATG), an internal research laboratory. The ATG thought it might replace the MOS 6502 of the Apple II range or the 68000 of the original Macintosh, or become the basis of a tablet device, under Paul Gavarini and Tom Pittard, in a project labelled Möbius. A partnership was established with Acorn Computers, and VLSI in 1990, and work began on a chip for small devices. The first Apple products with an ARM system on a chip were the 1993 Newton personal digital assistant, the 2001 iPod, and the 2007 iPhone. Apple has designed its own custom ARM chips since 2009, which it has since used in its iPhone, iPad, iPod, Apple TV, Apple Watch, AirPods, Beats, AirPort Time Capsule and HomePod products. Between October 2016 and August 2020, Intel-based Macs with Apple-designed ARM co-processors were released.
In the 2010s, media reports documented Apple's frustrations and challenges with the pace and quality of Intel's technology development. Apple reportedly had trouble with Intel modems for iPhones in 2017 due to technical issues and missed deadlines. Meanwhile, a 2018 report suggested that Intel chip issues prompted a redesign of the MacBook. In 2019, Apple blamed Intel processor shortages for a decline in Mac sales. In June 2020, former Intel principal engineer François Piednoël said Intel's "abnormally bad" quality assurance in its Skylake processors, making Apple "the number one filer of problems in the architecture", helped Apple decide to migrate. Intel CTO Mike Mayberry countered that quality assurance problems may arise at large scale from any CPU vendor.
History
Early involvement with ARM
In 1983, Acorn Computers started working on a project to design its own CPU architecture and instructions set, called the Acorn RISC Machine (ARM). In 1985, Apple's Advanced Technology Group worked with Acorn to create an experimental prototype, code-named Mobius, to replace the Apple II, using a modified ARM processor. The project was cancelled but Apple again partnered with Acorn when it needed a low-power, efficient processor for its future Newton PDA. In 1990, a new joint-venture was created between Acorn, Apple and VLSI Technology with the goal of pursuing the development of the ARM processor. The company was named Advanced RISC Machines Ltd, becoming the new meaning of the ARM acronym. One of the first designs of the new company would be the ARM610 SoC, initially for Apple, that allowed the Endianness to be swapped, increased the address space from 26 bit (64 MB) to 32 bit (4 GB), and modified the memory management unit. Apple held a 43% stake in the company, which was reduced to 14.8% in 1999.
Switch from PowerPC to Intel
In 2005 and 2006, Apple moved its Macintosh computers from IBM's PowerPC CPUs to Intel's x86 CPU architecture. At his 2005 WWDC keynote address, Steve Jobs said that continuing to use PowerPC processors, which consumed more energy than Intel chips, would prevent Apple from making better workstation computers and laptops. "As we look ahead, we can envision some amazing products we want to build...And we don't know how to build them with the future PowerPC roadmap", Jobs said. In addition, he admitted that Mac OS X was being ported to the Intel architecture since as early as 2001.
By June 2006, only Apple's high-end desktop computer and server products were still using PowerPC processors. The hardware transition was completed when Intel-based Mac Pros and Xserve computers were announced in August 2006 and shipped by the end of the year.
Apple ceased support for booting on PowerPC as of Mac OS X 10.6 "Snow Leopard in August 2009, three years after the transition was complete. Support for PowerPC applications via Rosetta was dropped from macOS in 10.7 "Lion" in July 2011, five years after the transition was complete.
Processor development
In 2008, Apple bought processor company P.A. Semi for million. At the time, it was reported that Apple bought P.A. Semi for its intellectual property and engineering talent. CEO Steve Jobs later claimed that P.A. Semi would develop system-on-chips for Apple's iPods and iPhones. Following the acquisition, Apple signed a rare "Architecture license" with ARM, allowing the company to design its own core, using the ARM instruction set. The first Apple-designed chip was the A4, released in 2010, which debuted in the first-generation iPad, then in the iPhone 4. Apple subsequently released a number of products with its own processors.
Rumors of Apple shifting Macintosh to custom-designed ARM processors began circulating in 2011, when SemiAccurate predicted it would happen by mid-2013. In 2014, MacRumors reported that Apple was testing an ARM-based Mac prototype with a large Magic Trackpad. In 2018, Bloomberg reported that Apple was planning to use its own chips based on the ARM architecture beginning in 2020.
The Apple A12X Bionic processor used in the iPad Pro (3rd generation) reportedly roughly matched the performance of Intel's Core i7 processor used in the MacBook Pro at the time.
In the months and weeks leading up to Apple's 2020 WWDC, multiple media reports anticipated an official announcement of the transition during the event.
Transition process
2020
Apple announced its plans to shift the Macintosh platform to Apple silicon at WWDC in June 2020. The entire transition of the Macintosh product line was expected to take "about two years", with the first ARM-based Macs released by the end of 2020. Similar language was used during Apple's 2005–2006 transition to Intel, which actually took about one year.
All Apple apps included with macOS Big Sur are compatible with x86-64 and ARM architectures. Many third-party apps are similarly being made dual-platform, including prominent software packages such as Adobe Photoshop and Microsoft Word.
To enable x86-native software to run on new ARM-based Macs, Apple embedded Rosetta 2 dynamic binary translation software in Big Sur. Universal binary 2 enabled application developers to support both x86-64 and ARM64.
To enable developers to create software for ARM-based Macs before they went on sale, Apple introduced the Universal App Quick Start Program, which allowed developers to pay $500 to rent a Developer Transition Kit (DTK), a computer built around the A12Z chip originally used in the iPad Pro (4th generation) and housed in a Mac Mini case.
In November 2020, Apple announced the Apple M1, its first ARM-based system on a chip to be used in Macs, alongside updated models of the Mac Mini, MacBook Air and 13-inch MacBook Pro based on it.
2021
In April 2021, Apple released a redesigned 24-inch iMac based on the M1 to replace the 21.5-inch Intel model.
In October 2021, Apple announced the M1 Pro and M1 Max, and updated 14-inch and 16-inch MacBook Pro models based on them. The M1 Pro and M1 Max use integrated Apple-designed GPUs, replacing the integrated and discrete GPUs supplied by Intel and AMD, and lack support for external GPUs. Apple discontinued all of their Intel-based laptops following the announcement.
2022
In March 2022, Apple announced the Mac Studio, a new high-end compact desktop model that uses the M1 Ultra, a dual-SoC configuration of two M1 Max chips. Apple concurrently discontinued the 27-inch Intel-based iMac, leaving the Mac Pro and Core i5/i7 Mac Mini as the last Intel-based Macs. Senior vice president of hardware engineering John Ternus confirmed the development of an Apple Silicon-based Mac Pro.
2023
In January 2023, Apple announced updated Mac Mini models based on the M2 and M2 Pro, and discontinued the previous Intel Core i5/i7 model, leaving the Mac Pro as the last Intel-based Mac.
On June 5, 2023, Apple announced an Apple silicon Mac Pro based on the M2 Ultra chip during the 2023 Worldwide Developers Conference keynote. The Intel Mac Pro, the last Mac with an Intel processor, was discontinued, officially marking the end of sales of Intel-based Macs and completing the "two-year transition" to Apple silicon almost three years after it was announced, or two years and seven months between the release of the first Apple silicon Mac and discontinuation of the last Intel Mac.
Impact
In June 2020, tech analyst Daniel Newman estimated that Apple accounted for $1.5 billion to $3.0 billion (about 2% to 4%) of Intel's annual revenue, and only 6.9% to 12% of the PC market in the United States and 7% globally. Some speculated that Apple's move away from Intel chips could prompt other customers to do the same. CNET speculated that the transition might reduce Apple's component costs.
Users and developers
Apps created for the iOS platform can run natively on ARM-powered Macs.
The transition could restrict or even eliminate hobbyist "Hackintosh" computers, which use commodity PC hardware to run macOS, in violation of license restrictions.
The Boot Camp software, which enables Intel-based Macs to natively run Microsoft Windows in an Apple-supported dual booting environment, is not implemented on Apple silicon-based Macs. , Apple said it has "no plans to direct boot into Windows" on ARM-based Macintosh computers. Apple's senior vice president of software engineering Craig Federighi suggested that virtualization technology is a viable alternative: "Purely virtualization is the route... Hypervisors can be very efficient, so the need to direct boot shouldn't really be the concern."
As of 2022, Parallels Desktop for Mac preloads an ARM64 version of Windows 11 onto Apple Silicon-based Macs, and can also run ARM64 Windows 10 and Linux. Microsoft officially endorses the use of Parallels Desktop for Mac to run Windows 11.
Reception
Before Apple released M1 Macs, Wired expressed skepticism that Apple's designers could use smartphone-related processors to drive a Mac Pro. It also questioned Apple's vague commitment to allow Intel binaries to run on ARM-based Macs "for years to come" and wondered which upcoming version of macOS would cease to support Intel Macs.
Laurent Giret remarked that Apple might "succeed where Microsoft has failed" due to Apple's "tight integration" of hardware and software, and a vast collection of applications that can already run on the new platform.
When systems containing M1 processors were released, they received near-universal acclaim for their high speed and low energy consumption.
Timeline
June 22, 2020: Apple announced its plans to shift the Macintosh platform to Apple silicon at WWDC. Apple introduces the Universal App Quick Start Program, which allowed developers to pay $500 to rent a Developer Transition Kit (DTK), a computer built around the A12Z chip originally used in the iPad Pro (4th generation) and housed in a Mac Mini case.
November 11, 2020, Apple announced the Apple M1, its first ARM-based system on a chip to be used in Macs. M1 versions of the Mac Mini, MacBook Air and 13-inch MacBook Pro are announced, replacing their Intel counterparts.
April 24, 2021, Apple released a 24-inch iMac based on the M1, replacing the 21.5-inch Intel iMac.
October 26, 2021, Apple announced the M1 Pro and M1 Max, and updated 14-inch and 16-inch MacBook Pro models based on them, replacing their Intel counterparts. Apple discontinued all of their Intel-based laptops following the announcement.
March 8, 2022, Apple announced the Mac Studio, a new high-end desktop model that uses the M1 Ultra, replacing the 27-inch Intel iMac. Senior vice president of hardware engineering John Ternus confirmed the development of an Apple Silicon-based Mac Pro.
January 17, 2023, Apple announced updated Mac Mini models based on the M2 and M2 Pro, replacing the Intel Core i5/i7 models.
June 5, 2023: "Transition Complete" - Apple announced an Apple silicon Mac Pro based on the M2 Ultra chip during the 2023 Worldwide Developers Conference keynote, replacing the Intel Mac Pro.
June 5, 2028: Intel hardware will reach "vintage" status after having been discontinued five years prior, ending most of Apple's service and parts support for Intel hardware.
June 5, 2030: Intel hardware will reach "obsolete" status after having been discontinued seven years prior, ending all of Apple's service and parts support for Intel hardware.
See also
Mac transition to Intel processors
Apple silicon
Fat binary
References
Macintosh platform | Mac transition to Apple silicon | [
"Technology"
] | 2,939 | [
"Computing platforms",
"Macintosh platform"
] |
64,333,687 | https://en.wikipedia.org/wiki/Marion%20McQuillan | Marion McQuillan (30 October 1921 – 24 June 1998) was a British metallurgist who specialised in the engineering uses for titanium and its alloys. She researched jet engine metals and was on the first team to research titanium for the Royal Aircraft Establishment Farnborough (RAE).
Biography
Marion Katherine Blight was born in Watford in 1921. Her mother worked in domestic service while her father was a shop assistant. McQuillan attended Wycombe High School before getting a scholarship to Henrietta Barnett’s School. McQuillan went to University in 1939 where she graduated from Girton College, Cambridge with a degree in metallurgy and natural sciences. She got her first job in 1942 in the Royal Aircraft Establishment Farnborough (RAE) in 1942. McQuillan researched jet engine metals and was a member of the first team to research titanium.
In 1946 she travelled through Germany and Austria as member of one of the many teams sent by the British Intelligence Objectives Sub-Committee, collecting technical information from universities, research establishments and factories.
She also worked at the Atomic Energy Research Establishment at Harwell, working on some of the early metallurgical problems of nuclear energy. From 1948-1951 she was at the Australian Royal Aircraft Establishment in Melbourne.
McQuillan returned to the UK where she began to work for ICI Metals (also known as IMI), in the Titanium Alloy Research Department where, within two years later she was head of the section. With her husband McQuillan published the seminal book “Titanium” in 1956. During the 1960s McQuillan registered 8 titanium alloy patents. In 1967 McQuillan was appointed technical director of the New Metals Division and by 1978 she became the first woman managing director of Imperial Metal Industries subsidiary, Enots.
Publications
Jun 1943. Further report on the use of aged chromate baths to specification DTD 911, Bath iii (30 minute hot chromate bath). Petch M K. RAE MR7147(A). Met/RTN/22
Feb 1944. Variations in corrosion properties over magnesium alloy sheet. Jones E R W Petch M K. RAE MR6858. Met/RTN/21, also in J. Inst. Metals, Nov. I946
Feb 1944. Protection of magnesium alloy sheet to specification DTD 118 by a modified form of the I.G. acid dip (bath iv of specification.DTD 911). Petch M K. RAE MR7588. Met/RTN/23
Mar 1944. Protection of magnesium alloys against corrosion by electrolytic chromate films. Petch M K. RAE MR3726(D). Met/RTN/17
Nov 1944. The protection of magnesium alloy components against corrosion by sprayed coatings of "Thickal" Latex. Petch M K. RAE MR7290. Met/RTN/22
1949. Some Observations on the Behaviour of Platinum/Platinum-Rhodium Thermocouples at High Temperatures. M K McQuillan. Journal of Scientific Instruments, Volume 26, Number 10
1956. Titanium - Metallurgy of the Rarer Metals – 4. by McQuillan MK.; Publisher: London, Butterworths, 1956.
1956. Titanium. McQuillan, A. D.; McQuillan, M. K.; Castle, J. G.Physics Today, vol. 9, issue 10, p. 24. Publication Date: 00/1956
1956. Titanium. Alan Dennis McQuillan; Marion Katharine McQuillan. Publisher: New York : Academic Press ; London : Butterworths Scientific Publications, 1956.
1957. Titanium. Alan D MacQuillan; Marion Katharine Macquillan. Publisher: London Butterworth [1957]
1958. Titan. Alan Denis McQuillan; Marion Katharine McQuillan; Sergej Georgievič Glazunov; Leonid Pavlovič Lužnikov.Language: Russian . Publisher: Moskva : Gosudarstvennoe Naučno-Tehničeskoe Izdatel'stvo Literatury po Černoj i Cvetnoj Metallurgii, 1958.
1978. McQuillan, Marion. Graduate Engineers in Production. Cranfield Inst of Tech, 1978.
1979. Graduate myth. Production Engineer (Volume: 58 , Issue: 4 , April 1979 )
Patents
GB772534A Improvements in or relating to titanium base alloys
CH457874A Verfahren zur Wärmebehandlung einer Titanlegierung
GB929931A Titanium-base alloys and their heat treatment
US3007824A Method of heat treating a ti-be alloy
US3118828A Electrode structure with titanium alloy base
FI35168A Sätt att framställa en elektrod
DE1112838B Verfahren zum Oberflaechenhaerten von (ª‡ú½ª‰) Ti-Legierungen
Awards
McQuillan was awarded the Rosenhain Medal in 1965. She was on the Interservices Metallurgical Research Council until 1989 and in 1967 served as vice-president of the Institute of Metals. In 1968 she was fundamental to the First International Conference on Titanium in London.
Personal life
She married fellow metallurgist Norman Petch whom she met in Cambridge but they divorced in 1944. She went on to marry metallurgist, Alan Dennis McQuillam in 1947. Her husband died in 1987. McQuillan died in Gloucestershire in 1998.
References
1921 births
1998 deaths
People from Watford
Metallurgists
People from Gloucestershire
People educated at Wycombe High School | Marion McQuillan | [
"Chemistry",
"Materials_science"
] | 1,163 | [
"Metallurgists",
"Metallurgy"
] |
64,334,237 | https://en.wikipedia.org/wiki/Subtraction%20game | In combinatorial game theory, a subtraction game is an abstract strategy game whose state can be represented by a natural number or vector of numbers (for instance, the numbers of game tokens in piles of tokens, or the positions of pieces on board) and in which the allowed moves reduce these numbers. Often, the moves of the game allow any number to be reduced by subtracting a value from a specified subtraction set, and different subtraction games vary in their subtraction sets. These games also vary in whether the last player to move wins (the normal play convention) or loses (misère play convention). Another winning convention that has also been used is that a player who moves to a position with all numbers zero wins, but that any other position with no moves possible is a draw.
Examples
Examples of notable subtraction games include the following:
Nim is a game whose state consists of multiple piles of tokens, such as coins or matchsticks, and a valid move removes any number of tokens from a single pile. Nim has a well-known optimal strategy in which the goal at each move is to reach a set of piles whose nim-sum is zero, and this strategy is central to the Sprague–Grundy theorem of optimal play in impartial games. However, when playing only with a single pile of tokens, optimal play is trivial (simply remove all the tokens in a single move).
Subtract a square is a variation of nim in which only square numbers of tokens can be removed in a single move. The resulting game has a non-trivial strategy even for a single pile of tokens; the Furstenberg–Sárközy theorem implies that its winning positions have density zero among the integers.
Fibonacci nim is another variation of nim in which the allowed moves depend on the previous moves to the same pile of tokens. On the first move to a pile, it is forbidden to take the whole pile, and on subsequent moves, the amount subtracted must be at most twice the previous amount removed from the same pile.
Wythoff's game is played by placing a chess queen on a large chessboard and, at each step, moving it (in the normal manner of a chess queen) towards the bottom side, left side, or bottom left corner of the board. This game may be equivalently described with two piles of tokens, from which each move may remove any number of tokens from one or both piles, removing the same amount from each pile when both piles are reduced. It has an optimal strategy involving Beatty sequences and the golden ratio.
Theory
Subtraction games are generally impartial games, meaning that the set of moves available in a given position does not depend on the player whose turn it is to move. For such a game, the states can be divided up into -positions (positions in which the previous player, who just moved, is winning) and -positions (positions in which the next player to move is winning), and an optimal game playing strategy consists of moving to a -position whenever this is possible. For instance, with the normal play convention and a single pile of tokens, every number in the subtraction set is an -position, because a player can win from such a number by moving to zero.
For normal-play subtraction games in which there are multiple numbers, in which each move reduces only one of these numbers, and in which the reductions that are possible from a given number depend only on that number and not on the rest of the game state, the Sprague–Grundy theorem can be used to calculate a "nim value" of each number, a number representing an equivalent position in the game of nim, such that the value of the overall game state is the nim-sum of its nim-values. In this way, the optimal strategy for the overall game can be reduced to the calculation of nim-values for a simplified set of game positions, those in which there is only a single number. The nim-values are zero for -positions, and nonzero for -positions; according to a theorem of Tom Ferguson, the single-number positions with nim-value one are exactly the numbers obtained by adding the smallest value in the subtraction set to a -position. Ferguson's result leads to an optimal strategy in multi-pile misère subtraction games, with only a small amount of change from the normal play strategy.
For a subtraction game with a single pile of tokens and a fixed (but possibly infinite) subtraction set, if the subtraction set has arbitrarily large gaps between its members, then the set of -positions of the game is necessarily infinite. For every subtraction game with a finite subtraction set, the nim-values are bounded and both the partition into -positions and -positions and the sequence of nim-values are eventually periodic. The period may be significantly larger than the maximum value in the subtraction set, but is at most . However, there exist infinite subtraction sets that produce bounded nim-values but an aperiodic sequence of these values.
Complexity
For subtraction games with a fixed (but possibly infinite) subtraction set, such as subtract a square, the partition into P-positions and N-positions of the numbers up to a given value may be computed in time . The nim-values of all numbers up to may be computed in time where denotes the size of the subtraction set (up to ) and denotes the largest nim-value occurring in this computation.
For generalizations of subtraction games, played on vectors of natural numbers with a subtraction set whose vectors can have positive as well as negative coefficients, it is an undecidable problem to determine whether two such games have the same P-positions and N-positions.
See also
Grundy's game and octal games, generalizations of subtraction games in which a move may split a pile of tokens in two
Notes
References
Combinatorial game theory | Subtraction game | [
"Mathematics"
] | 1,273 | [
"Recreational mathematics",
"Game theory",
"Combinatorial game theory",
"Combinatorics"
] |
64,336,144 | https://en.wikipedia.org/wiki/C19H26O4 | {{DISPLAYTITLE:C19H26O4}}
The molecular formula C19H26O4 (molar mass: 318.407 g/mol, exact mass: 318.1831 u) may refer to:
2-Methoxyestriol (2-MeO-E3)
4-Methoxyestriol (4-MeO-E3)
Molecular formulas | C19H26O4 | [
"Physics",
"Chemistry"
] | 86 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
64,336,253 | https://en.wikipedia.org/wiki/Transistor%20aging | Transistor aging (sometimes called silicon aging) is the process of silicon transistors developing flaws over time as they are used, degrading performance and reliability, and eventually failing altogether. Despite the name, similar mechanisms may affect transistors made of any kind of semiconductor. Manufacturers compensate for this (as well as manufacturing defects) by running chips at slower speeds than they are initially capable of (underclocking).
Causes
The main causes of transistor aging in MOSFETs are electromigration and charge trapping.
Electromigration is the movement of ions caused by momentum from the transfer of electrons in the conductor. This results in degradation of the material, causing intermittent glitches that are very difficult to diagnose, and eventual failure.
Charge trapping is related to time-dependent gate oxide breakdown, and manifests as an increase in resistance and threshold voltage (the voltage needed for the transistor to conduct), and a decrease in drain current. This degrades the chip performance over time, until ultimately the thresholds collapse. Charge trapping occurs in several ways:
Hot carrier injection (HCI) is where electrons gain enough energy to leak into the oxide, becoming trapped there and possibly damaging it.
Random telegraph noise (RTN) can also result, where the drain current fluctuates between several discrete levels, and is worsened with increasing temperature.
Bias temperature instability (BTI) is where charge leaks into the oxide when voltage is applied to the gate, even with no current flowing through the transistor. When the voltage is removed from the gate, the charges gradually dissipate between milliseconds or hours.
Charge trapping was determined by John Szedon and Ting L. Chu to be a viable means of storing digital information, and was developed into the SONOS, MirrorBit, and 3D NAND flash memory technologies (charge trap flash).
See also
High-temperature operating life
Reliability (semiconductor)
Underclocking
Raptor Lake § Instability and degradation issue
References
Transistors
Semiconductor device defects | Transistor aging | [
"Technology"
] | 415 | [
"Technological failures",
"Semiconductor device defects"
] |
65,800,149 | https://en.wikipedia.org/wiki/List%20of%20plant%20genus%20names%20with%20etymologies%20%28D%E2%80%93K%29 | Since the first printing of Carl Linnaeus's Species Plantarum in 1753, plants have been assigned one epithet or name for their species and one name for their genus, a grouping of related species. Many of these plants are listed in Stearn's Dictionary of Plant Names for Gardeners. William Stearn (1911–2001) was one of the pre-eminent British botanists of the 20th century: a Librarian of the Royal Horticultural Society, a president of the Linnean Society and the original drafter of the International Code of Nomenclature for Cultivated Plants.
The first column below contains seed-bearing genera from Stearn and other sources as listed, excluding those names that no longer appear in more modern works, such as Plants of the World by Maarten J. M. Christenhusz (lead author), Michael F. Fay and Mark W. Chase. Plants of the World is also used for the family and order classification for each genus. The second column gives a meaning or derivation of the word, such as a language of origin. The last two columns indicate additional citations.
Key
Latin: = derived from Latin (otherwise Greek, except as noted)
Ba = listed in Ross Bayton's The Gardener's Botanical
Bu = listed in Lotte Burkhardt's Index of Eponymic Plant Names
CS = listed in both Allen Coombes's The A to Z of Plant Names and Stearn's Dictionary of Plant Names for Gardeners
G = listed in David Gledhill's The Names of Plants
St = listed in Stearn's Dictionary of Plant Names for Gardeners
Genera
See also
Glossary of botanical terms
List of Greek and Latin roots in English
List of Latin and Greek words commonly used in systematic names
List of plant genera named for people: A–C, D–J, K–P, Q–Z
List of plant family names with etymologies
Notes
Citations
References
See http://creativecommons.org/licenses/by/4.0/ for license.
Further reading
Available online at the Perseus Digital Library.
Available online at the Perseus Digital Library.
Systematic
Gardening lists
Glossaries of biology
Greek words and phrases
Systematic
Etymologies,D
Genus names with etymologies (D–K)
Systematic
Taxonomy (biology)
Wikipedia glossaries using tables | List of plant genus names with etymologies (D–K) | [
"Biology"
] | 477 | [
"Lists of plants",
"Plants",
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists",
"Glossaries of biology"
] |
65,800,799 | https://en.wikipedia.org/wiki/SAE%20J3105 | SAE J3105 is a recommended practice for automated connection devices (ACD) that mate chargers with battery electric buses and heavy-duty vehicles. The practice is maintained by the SAE International with the formal title "Electric Vehicle Power Transfer System Using Conductive Automated Connection Devices Recommended Practice", and was first issued in January 2020. It covers the general physical, electrical, functional, testing, and performance requirements for automated conductive DC power transfer systems intended for heavy duty vehicles, focusing primarily on transit buses.
J3105 defines a common automated conductive charging system architecture so that any vehicle selecting one of the supplemental specific ACD implementations can use any charger that complies with that specific implementation, regardless of manufacturer, similar to how the earlier IEC 62196, SAE J1772, and SAE J3068 standards define the characteristics for a manually-plugged electric vehicle supply equipment interface.
History
SAE formed the Medium and Heavy-Duty Vehicle Conductive Charging Task Force in 2016 to develop a recommended practice for heavy-duty electric vehicle conductive charging. Participants in the Task Force included transit bus manufacturers (Gillig, New Flyer, Nova Bus, Proterra), charger manufacturers (ABB, Heliox, Opbrid, Siemens, Toshiba), interface manufacturers (Furrer+Frey, SCHUNK, Stäubli, Stemmann), electric utilities (EPRI, SMUD, SCE), transit operators (APTA, CTA, King County Metro, LACMTA, NYCTA), and interested parties (ANL, CalStart, CEC, CTE).
The Task Force first published the SAE J3068 recommended practice in 2018, building on work from existing international standards for charging using three-phase AC power. J3068 defines a manual Type 2 connector that can be used for both AC charging or DC charging up to 1000 V.
General design characteristics
Transit operators may use opportunity charging to extend the range of electric buses while stopped on a layover. This is in contrast to depot charging, where the buses are charged at a common garage or storage facility while out of service. An ACD system may be used for both opportunity and depot charging. For instance, the Schiphol Airport bus depot has overhead chargers at both 30 kW (depot charging) and 450 kW (opportunity charging) for its all-electric bus fleet.
J3105 defines two current levels of DC charging, with supply voltage from 250 to 1000 V:
Up to 600 A (350 kW)
Up to 1200 A (1200 kW)
These levels are mutually compatible; for instance, a Level 1 vehicle could connect to a Level 2 charger and would receive an appropriate amount of power. Specific requirements for the charging station and communication are governed by IEC 61851-23 and ISO 15118.
When a vehicle approaches a charger, wireless communications via IEEE 802.11n will pair the vehicle and charger. The initial communication will be used to guide the vehicle's driver to an appropriate position so the connection can be made, and communications will go through the Control Pilot interface after the vehicle is connected.
Only four interface connections are defined by J3105. The specific physical interfaces are defined in the supplemental recommended practices.
DC Power (+)
DC Power (–)
Ground / Protective Earth
Control Pilot
Specific charging implementations
J3105 includes three supplemental recommended practices for specific ACD implementations:
J3105-1 "Infrastructure-Mounted Cross Rail Connection" (or "Cross rail"): the overhead charging station extends contacts down on a pantograph to meet roof-mounted vehicle rails
J3105-2 "Vehicle-Mounted Pantograph Connection" (or "Bus up"): the vehicle extends a pantograph up from its roof to meet overhead charging station contacts
J3105-3 "Enclosed Pin and Socket Connection": the charging station extends a pin horizontally into a vehicle's roof-mounted socket
The physical characteristics are described in the specific ACD implementations. Each of the recommended practices for specific ACD implementations includes the conductor dimensions and spacing, and the required alignment and connection procedure.
A small amount of misalignment is tolerated, depending on the specific implementation:
Notes
Cross rail (J3105-1)
In the cross rail ACD implementation (officially, "Infrastructure-mounted Cross Rail Connection"), a curbside charging station includes an overhead structure overhanging the street. After the bus pulls up to the charging station, contacts are lowered from the overhead charger on a pantograph and connect to rails mounted on the forward roof of the bus.
The cross rail implementation is marketed commercially as OppCharge (opportunity charging) and the OppCharge consortium, led by Volvo Buses, includes several bus and charging infrastructure manufacturers. The first OppCharge station was deployed at the end of 2016 in Bertrange, Luxembourg by ABB for hybrid buses built by Volvo. In the United States, the first OppCharge stations were deployed in 2019 by New Flyer Infrastructure Solutions as on-route chargers for the New York City Transit Authority along its M42 route.
Bus up (J3105-2)
The bus up ACD implementation (officially, "Vehicle-mounted Pantograph Connection") also uses an overhead charger, but the charging contacts remain fixed in place while the bus extends a pantograph up from its roof to meet the charger. The charging contacts are on the underside of a long hooded enclosure to facilitate the bus and charger contact connection.
The bus up implementation has been adopted by VDL Bus & Coach using chargers provided by Heliox, with both companies based in The Netherlands. The charging depots at Schiphol Airport were the largest electric bus charger installation in Europe when they were completed in 2018, including 23 450 kW opportunity chargers and 84 30 kW depot chargers from Heliox, servicing a fleet of 100 VDL Citea SLFA articulated buses equipped with bus-up pantographs. Heliox also introduced a dual-interface system compatible with both top-down (J3105-1) and bus-up (J3105-2) vehicles in 2018.
Pin and socket (J3105-3)
In the pin and socket ACD implementation (officially, "Enclosed Pin and Socket Connection"), a pin is inserted horizontally from a curbside charging station into a socket with a guiding funnel on the roof of the vehicle.
The pin and socket implementation was developed by Stäubli, who market it as the Quick Charging Connector (QCC). QCC has been implemented on a test basis at ports in Hamburg (6 charging stations and 25 automated guided vehicles [AGV]) and Singapore (3 stations and 22 AGVs). In addition, the Port of Long Beach has announced its intentions to convert an existing fleet of 33 diesel-powered tractors to battery-electric drivetrains, which will include the installation of charging stations. The quantity of charging stations, built by Tritium and fitted with the Stäubli QCC system, will be sufficient to allow all 33 tractors to be charged simultaneously. The Long Beach charger installation was completed in December 2023.
Rejected implementation
A fourth ACD implementation ("Infrastructure-Mounted Blade Connection" or "Blade") was part of the preliminary development, but marketing was discontinued during development of the J3105 standard and the Blade implementation was not included in the initial issue.
Blade
The blade ACD implementation ("Infrastructure-mounted Blade Connection") is similar to the cross rail implementation, as both use an overhead charging device with a passive vehicle contact. However, in the blade implementation, a funnel-like "scoop" on the roof of the bus is used to mechanically guide the charger shoe onto a "blade" charging contact at the rear roof of the bus. The blade implementation is slower to engage than the cross rail, but the docking process to mate the vehicle to the charger is more automated.
The blade implementation was developed by Proterra for its line of battery-electric buses. Proterra offered royalty-free access to its patented design starting in 2016. Despite this, the blade design was not adopted by other manufacturers and the blade implementation was eventually dropped from J3105 during development, some time after 2018. Proterra has since adopted J3105-1 (pantograph-down) or J3105-2 (pantograph-up) charging systems for newer buses.
Notes
References
External links
SAE Medium and Heavy Duty Vehicle Conductive Charging Task Force
Charging stations
International Electrotechnical Commission
Mains power connectors
Plug-in hybrid vehicle industry
Automotive standards | SAE J3105 | [
"Engineering"
] | 1,789 | [
"Electrical engineering organizations",
"International Electrotechnical Commission"
] |
65,801,823 | https://en.wikipedia.org/wiki/BD-07%20436 | BD-07 436, also known as WASP-77 since 2012, is a binary star system about 344 light-years away. The star's components appears to have a different age, with the secondary older than 9 billion years, while the primary's age is 5 billion years. The BD-07 436 system's concentration of heavy elements is similar to the Sun. Its stars display moderate chromospheric activity, including x-ray flares.
The primary is a G-type main-sequence star, BD-07 436A (WASP-77A). The star is rotating rapidly, being spun up by the tides raised by the giant planet WASP-77Ab on its close orbit. The secondary is a K-type main-sequence star BD-07 436B orbiting at a distance of 461 AU.
Planetary system
In 2012 a transiting hot Jupiter planet b was detected on a very tight, circular orbit. The planet may have an extended gaseous envelope and is losing mass. Its equilibrium temperature is 1715 K,the nightside temperature measured in 2019 is 1786 K, and dayside planetary temperature measured in 2020 is 1842 K.
Water vapour was detected on the planetary dayside of WASP-77Ab, indicating C/O ratio similar to solar or even lower.
References
Cetus
G-type main-sequence stars
K-type main-sequence stars
Binary stars
Planetary systems with one confirmed planet
Planetary transit variables
J02283722-0703384
Durchmusterung objects | BD-07 436 | [
"Astronomy"
] | 318 | [
"Cetus",
"Constellations"
] |
65,803,419 | https://en.wikipedia.org/wiki/T.%20Mark%20Harrison | T. Mark Harrison is an American isotope geochemist based in California. He is Distinguished Professor of Geochemistry in the Department of Earth, Planetary and Space Sciences, University of California – Los Angeles.
Education
A native of Vancouver, Canada, Harrison received his B.Sc. (Hons.) from the University of British Columbia, in 1977. His Ph.D. research from 1978 to 1980 developing 40Ar/39Ar thermochronology was conducted under the supervision of Prof. Ian McDougall at the Australian National University.
Academic life
Following a postdoctoral fellowship at the Carnegie Institution of Washington, Harrison spent 8 years on the faculty of the department of geological sciences at the State University of New York at Albany rising from assistant to full professor. In 1989, he moved to UCLA, where he served as chair of the department of earth and space sciences from 1997 to 2000 becoming a distinguished professor in 2003. He took leave from UCLA to take up an appointment as university professor and director of the Research School of Earth Sciences at the Australian National University from 2001 to 2006. He returned to UCLA in 2006 to take up Directorship of the Institute of Geophysics and Planetary Physics until 2011.
Awards
Harrison received the Presidential Young Investigator Award of the National Science Foundation in 1985, the Outstanding Young Alumnus Award of the University of British Columbia in 1988, the Norman L. Bowen Award of the American Geophysical Union in 1995, the Outstanding Contributions in Geoscience Research award from the Department of Energy in 1996, and the Arthur L. Day Medal of the Geological Society of America in 2009. In 2021 Harrison was awarded the Walter Bucher medal of the American Geophysical Union, and in 2023 the Dodson Prize of the International standing Committee on Thermochronology.
He is a Fellow of the American Geophysical Union (1996), the Geochemical Society (2007), the European Association of Geochemistry (2007), and Geological Society of Australia (2007). He is member of both the Australian Academy of Science and the U.S. National Academy of Science and an Einstein Professor of the Chinese Academy of Sciences.
Research interests
Harrison has published over 260 papers and books on a range of topics including the evolution of the Tibet-Himalaya orogenic system, geochemical kinetics, the origin and transport of magmas, geochronology, interpretive models for heat and mass flow, evolution of petroleum reservoirs and geothermal systems, and investigations of the very early Earth, including documenting the earliest evidence of oceans, continents, plate tectonics, and life. He is the co-author of the monograph Geochronology and Thermochronology by the 40Ar/39Ar Method (1999) and author of Hadean Earth (2020). His publications have attracted over 60,000 citations and correspond to an H-index value of 117.
References
Living people
American geochemists
University of California, Los Angeles faculty
University of British Columbia alumni
Australian National University alumni
1952 births | T. Mark Harrison | [
"Chemistry"
] | 604 | [
"Geochemists",
"American geochemists"
] |
65,803,478 | https://en.wikipedia.org/wiki/WASP-72 | WASP-72 (also known as CD-30 1019 and officially named Diya) is the primary of a binary star system. It is an F7 class dwarf star, with an internal structure just on the verge of the Kraft break. It is orbited by a planet WASP-72b. The age of WASP-72 is younger than the Sun at 3.55 billion years.
The primary seems to have UV-opaque matter in the line-of-sight, which may originate from atmosphere escaping from WASP-72b or from an unknown object in the interstellar medium. WASP-72 was named Diya in 2019.
A faint stellar companion WASP-72B was discovered in 2020 at a projected separation of 281 AU. It may still be a false positive, with a probability of 0.02%.
Planetary system
The transiting hot Jupiter exoplanet orbiting WASP-72 was discovered by WASP in 2012. The planetary orbit is well aligned to the equatorial plane of the star, with misalignment equal to . Despite the close proximity of the planet to the parent star, orbital decay was not detected as of 2020. The planetary equilibrium temperature is 2210 K, compatible with the measured dayside temperature of 2098 K.
WASP-72b was named "Cuptor" in 2019 by Mauritian amateur astronomers as part of the NameExoWorlds contest.
References
F-type main-sequence stars
Planetary systems with one confirmed planet
Binary stars
Planetary transit variables
Fornax
J02440959-3010085
Durchmusterung objects | WASP-72 | [
"Astronomy"
] | 321 | [
"Constellations",
"Fornax",
"Astronomy organizations",
"Wide Angle Search for Planets"
] |
65,804,492 | https://en.wikipedia.org/wiki/Pressure%20bag%20moulding | Pressure bag moulding is a process for moulding reinforced plastics. This process is related to vacuum bag molding.
Procedure
A solid female mold is used along with a flexible male mold. The reinforcement is placed inside the female mold with just enough resin to permit the fabric to stick in place (wet lay-up). A measured amount of resin is then liberally brushed indiscriminately into the mold and the mold is then clamped to a machine that includes the male flexible mold. Then, the flexible male membrane is inflated with heated compressed air or possibly steam. The female mold can also be heated. Excess resin is forced out along with trapped air. Due to the lower cost of unskilled labor, this method is used extensively in the production of composite helmets. For a helmet bag moulding machine, cycle times vary from 20 to 45 minutes, but if the molds are heated, the finished shells require no further curing.
References
Composite materials
Composite material fabrication techniques | Pressure bag moulding | [
"Physics"
] | 202 | [
"Materials",
"Composite materials",
"Matter"
] |
65,804,516 | https://en.wikipedia.org/wiki/Autoclave%20moulding | Autoclave moulding is an advanced composite manufacturing process.
Procedure
It is a process that uses a two-sided mould set that forms both surfaces of the panel. On the upper side is a flexible membrane made from silicone or an extruded polymer film such as nylon and on the lower side is a rigid mould. Reinforcement materials can be placed manually or robotically. They involve continuous fibre forms fashioned into textile constructions. Usually, they are pre-impregnated with the resin in the form of prepreg fabrics or unidirectional tapes. In some situations, a film of resin is placed upon the lower mould, and dry reinforcement is placed above. The upper mould is installed, and the vacuum is applied to the mould cavity. The assembly is placed into an autoclave. This process is generally performed at both elevated pressure and elevated temperature. The use of elevated pressure facilitates a high fibre volume fraction and low void content for maximum structural efficiency.
References
Composite materials
Composite material fabrication techniques | Autoclave moulding | [
"Physics"
] | 208 | [
"Materials",
"Composite materials",
"Matter"
] |
65,804,540 | https://en.wikipedia.org/wiki/Resin%20transfer%20moulding | Resin transfer moulding (RTM) is a process for producing high performance composite components.
Procedure
It is a process using a rigid two-sided mould set that forms both surfaces of the panel. Usually, the mould is formed from aluminum or steel, but sometimes composite molds are used. The two sides fit together to make a mould cavity. The distinctive feature of resin transfer moulding is that the reinforcement materials are placed into this cavity, and before the introduction of the matrix material, the mould set is closed. Resin transfer moulding involves numerous varieties which differ in the mechanics of how the resin is introduced to the reinforcement in the mould cavity. These variations include everything from the RTM methods used in out of autoclave composite manufacturing for high-tech aerospace components to vacuum infusion (for resin infusion see also boat building) to vacuum assisted resin transfer moulding (VARTM). This method can be done at either ambient or elevated temperature and is suitable for manufacturing high-performance composite components in medium volumes (1,000s to 10,000s of parts).
References
Composite materials
Composite material fabrication techniques | Resin transfer moulding | [
"Physics"
] | 234 | [
"Materials",
"Composite materials",
"Matter"
] |
65,804,611 | https://en.wikipedia.org/wiki/List%20of%20spyware%20programs | This is a list of spyware programs.
These common spyware programs illustrate the diversity of behaviours found in these attacks. Note that as with computer viruses, researchers give names to spyware programs which may not be used by their creators. Programs may be grouped into "families" based not on shared program code, but on common behaviors, or by "following the money" of apparent financial or business connections. For instance, a number of the spyware programs distributed by Claria are collectively known as "Gator". Likewise, programs that are frequently installed together may be described as parts of the same spyware package, even if they function separately.
Spyware programs
CoolWebSearch, a group of programs, takes advantage of Internet Explorer vulnerabilities. The package directs traffic to advertisements on Web sites including coolwebsearch.com. It displays pop-up ads, rewrites search engine results, and alters the infected computer's hosts file to direct DNS lookups to these sites.
FinFisher, sometimes called FinSpy is a high-end surveillance suite sold to law enforcement and intelligence agencies. Support services such as training and technology updates are part of the package.
Gator, replaced banner ads on web sites with its own
GO Keyboard, virtual Android keyboard apps (GO Keyboard - Emoji keyboard and GO Keyboard - Emoticon keyboard), transmit personal information to its remote servers without explicit users' consent. This information includes user's Google account email, language, IMSI, location, network type, Android version and build, and device's model and screen size. The apps also download and execute a code from a remote server, breaching the Malicious Behavior section of the Google Play privacy policies. Some of these plugins are detected as Adware or PUP by many Anti-Virus engines, while the developer, a Chinese company GOMO Dev Team, claims in the apps' description that they will never collect personal data including credit card information. The apps with about 2 million users in total were caught spying in September 2017 by security researchers from AdGuard who then reported their findings to Google.
Hermit is a toolkit developed by RCS Lab for government agencies to spy on iOS and Android mobile phones.
HuntBar, aka WinTools or Adware.Websearch, was installed by an ActiveX drive-by download at affiliate Web sites, or by advertisements displayed by other spyware programs—an example of how spyware can install more spyware. These programs add toolbars to IE, track aggregate browsing behavior, redirect affiliate references, and display advertisements.
Internet Optimizer, also known as DyFuCa, redirects Internet Explorer error pages to advertising. When users follow a broken link or enter an erroneous URL, they see a page of advertisements. However, because password-protected Web sites (HTTP Basic authentication) use the same mechanism as HTTP errors, Internet Optimizer makes it impossible for the user to access password-protected sites.
Spyware such as Look2Me hides inside system-critical processes and start up even in safe mode. With no process to terminate they are harder to detect and remove, which is a combination of both spyware and a rootkit. Rootkit technology is also seeing increasing use, as newer spyware programs also have specific countermeasures against well known anti-malware products and may prevent them from running or being installed, or even uninstall them.
Movieland, also known as Moviepass.tv and Popcorn.net, is a movie download service that has been the subject of thousands of complaints to the Federal Trade Commission (FTC), the Washington State Attorney General's Office, the Better Business Bureau, and other agencies. Consumers complained they were held hostage by a cycle of oversized pop-up windows demanding payment of at least $29.95, claiming that they had signed up for a three-day free trial but had not cancelled before the trial period was over, and were thus obligated to pay. The FTC filed a complaint, since settled, against Movieland and eleven other defendants charging them with having "engaged in a nationwide scheme to use deception and coercion to extract payments from consumers."
Onavo Protect is used by Facebook to monetize usage habits within a privacy-focused environment, and was criticized because the app listing did not contain a prominent disclosure of Facebook's ownership. The app was removed from the Apple iOS App Store. Apple deemed it a violation of guidelines barring apps from harvesting data from other apps on a user's device.
Pegasus is spyware for iOS and Android mobile phones developed by NSO Group which received widespread publicity for its use by government agencies.
Zwangi redirects URLs typed into the browser's address bar to a search page at www.zwangi.com, and may also take screenshots without permission.
Programs distributed with spyware
Kazaa
Morpheus
WeatherBug
WildTangent
Programs formerly distributed with spyware
AOL Instant Messenger (AOL Instant Messenger still packages Viewpoint Media Player, and WildTangent)
DivX
FlashGet
magicJack
References
Spyware
Spyware
Types of malware
Rogue security software
Computer network security
Online advertising
Espionage techniques
Espionage devices
Identity theft
Security breaches
Deception | List of spyware programs | [
"Technology",
"Engineering"
] | 1,081 | [
"Cybersecurity engineering",
"Lists of software",
"Computing-related lists",
"Computer networks engineering",
"Computer network security"
] |
65,804,770 | https://en.wikipedia.org/wiki/Telephone%20game%20%28game%20theory%29 | The Telephone game is an example of a coordination game potentially having more than one Nash equilibrium proposed by David Lewis. The game was based on a convention in Lewis's home town of Oberlin, Ohio that when a telephone call was cut off then the caller would redial the callee.
Equilibrium analysis
This game involves two players in a town having a telephone service with only one telephone line that cuts callers off after a set period of time (e.g., five minutes) if their call is not completed. Assuming one player (the caller) calls a second player (the callee) and is cut-off, then the players will have two potential strategies - wait for the other to dial them back, or redial to call the other. If both players wait, then no call will be completed, resulting in zero benefit to either player. If both players call each other, then they will get a busy signal, again, resulting in zero benefit to either party. In a simple case where the cost of calling is negligible then it is equally optimal for both parties for one of the caller and the callee to wait whilst the other redials (represented as a benefit of 10 for both parties in Fig. 1) and as such this is a pure coordination game.
In a more complex version of the game (Fig. 2), if the cost of calling is high, then the players will prefer the waiting strategy with its resulting deadlock. If one player calls and the other waits then the player that waits will receive a benefit (say, 6) and the player that calls will receive a lesser benefit as they have to pay the cost of the call (say, 3). In this case there are two potential Nash equilibria.
References
Non-cooperative games | Telephone game (game theory) | [
"Mathematics"
] | 363 | [
"Game theory",
"Non-cooperative games"
] |
65,805,395 | https://en.wikipedia.org/wiki/Vits%C5%93 | Vitsœ, formerly known as Vitsœ-Zapf or Vitsœ & Zapf, is a British furniture company, originally German, known for its collaboration with Dieter Rams. Its furniture is widely known as a German design classic. The 620 system is currently used in the German Chancellery.
History
The company Vitsœ + Zapf was founded in Frankfurt am Main, Germany in 1959 by Danish furniture dealer Niels Vitsœ and German industrial designer Otto Zapf to produce furniture designed by Dieter Rams, who was already working for the consumer products company, Braun. Rams produced numerous furniture designs for Vitsœ, including the 606 Universal Shelving System and the 620 Chair programme. Otto Zapf left the company in 1969 and it was renamed simply ‘Vitsœ’.
Following several years of financial difficulties, the company was rescued by managing director Mark Adams in the 1990s, and moved production to the United Kingdom. In 2017 Vitsœ moved its workshop to a new HQ and production building, purpose-built out of wood and glass in Royal Leamington Spa, in central England.
Products
Vitsœ produces and sells the 606 Universal Shelving System (introduced in 1960) and the 620 Chair, both designed by Rams.
Design critic Spencer Bailey described the system as "one of the most—if not the most—functional and well-built designs I can think of."
References
External links
Vitsœ Website
Furniture companies of Germany
Manufacturing companies established in 1959
Furniture companies
1959 establishments in West Germany
Design companies established in 1959
Industrial design | Vitsœ | [
"Engineering"
] | 315 | [
"Industrial design",
"Design engineering",
"Design"
] |
65,807,245 | https://en.wikipedia.org/wiki/Black-box%20obfuscation | In cryptography, black-box obfuscation was a proposed cryptographic primitive which would allow a computer program to be obfuscated in a way such that it was impossible to determine anything about it except its input and output behavior. Black-box obfuscation has been proven to be impossible, even in principle.
Impossibility
The unobfuscatable programs
Barak et al. constructed a family of unobfuscatable programs, for which an efficient attacker can always learn more from any obfuscated code than from black-box access.
Broadly, they start by engineering a special pair of programs that cannot be obfuscated together. For some randomly selected strings of a fixed, pre-determined length , define one program to be one that computes
and the other program to one that computes
(Here, interprets its input as the code for a Turing machine. The second condition in the definition of is to prevent the function from being uncomputable.)
If an efficient attacker only has black-box access, Barak et al. argued, then the attacker only has an exponentially small chance of guessing the password , and so cannot distinguish the pair of programs from a pair where is replaced by some program that always outputs "0". However, if the attacker has access to any obfuscated implementations of , then the attacker will find with probability 1, whereas the attacker will always find unless (which should happen with negligible probability). This means that the attacker can always distinguish the pair from the pair with obfuscated code access, but not black-box access. Since no obfuscator can prevent this attack, Barak et al. conclude that no black-box obfuscator for pairs of programs exists.
To conclude the argument, Barak et al. define a third program to implement the functionality of the two previous:
Since equivalently efficient implementations of can be recovered from one of by hardwiring the value of , Barak et al. conclude that cannot be obfuscated either, which concludes their argument.
Impossible variants of black-box obfuscation and other types of unobfuscable programs
In their paper, Barak et al. also prove the following (conditional to appropriate cryptographic assumptions):
There are unobfuscatable circuits.
There is no black-box approximate obfuscator.
There are unobfuscatable, secure, probabilistic private-key cryptosystems.
There are unobfuscatable, secure, deterministic digital signature schemes.
There are unobfuscatable, secure, deterministic message authentication schemes.
There are unobfuscatable, secure pseudorandom functions.
For many protocols that are secure in the random oracle model, the protocol becomes insecure if the random oracle is replaced with an artificial cryptographic hash function; in particular, Fiat-Shamir schemes can be attacked.
There are unobfuscatable circuits in TC0 (that is, constant-depth threshold circuits).
There are unobfuscatable sampling algorithms (in fact, these cannot be obfuscated approximately).
There is no secure software watermarking scheme.
Weaker variants
In their original paper exploring black-box obfuscation, Barak et al. defined two weaker notions of cryptographic obfuscation which they did not rule out: indistinguishability obfuscation and extractability obfuscation (which they called "differing-inputs obfuscation".) Informally, an indistinguishability obfuscator should convert input programs with the same functionality into output programs such that the outputs cannot be efficiently related to the inputs by a bounded attacker, and an extractability obfuscator should be an obfuscator such that if the efficient attacker could relate the outputs to the inputs for any two programs, then the attacker could also produce an input such that the two programs being obfuscated produce different outputs. (Note that an extractability obfuscator is necessarily an indistinguishability obfuscator.)
, a candidate implementation of indistinguishability obfuscation is under investigation. In 2013, Boyle et al. explored several candidate implementations of extractability obfuscation.
References
Software obfuscation
Cryptographic primitives
Unsolvable puzzles | Black-box obfuscation | [
"Mathematics",
"Technology",
"Engineering"
] | 875 | [
"Cybersecurity engineering",
"Mathematical problems",
"Software obfuscation",
"Unsolvable puzzles"
] |
65,807,728 | https://en.wikipedia.org/wiki/Herbert%20L.%20Strauss | Herbert Leopold Strauss (March 26, 1936–December 2, 2014) was an American chemist who specialized in spectroscopy. His family fled Nazi Germany and eventually immigrated to New York, where he graduated from Columbia University. He spent the entirety of his career at the University of California, Berkeley.
Early life and education
Herbert Leopold Strauss, who went by "Herb", was born on March 26, 1936, in Aachen, Germany to parents Joan and Charles Strauss. He had a younger brother, Walter. The Strauss family escaped Germany in 1939, arriving in England. While in London, Herbert Strauss was temporarily placed in an orphanage, where he became seriously ill from bronchitis and nearly died. The family eventually immigrated to Kew Gardens, Queens in New York City. There, his father worked as a real estate agent and his mother worked in a clothing store. Strauss received both a bachelor's degree (1957) and a PhD (1960) in chemistry from Columbia University.
Career
Upon finishing his PhD, he spent a year conducting post-doctoral research at the University of Oxford. The first teaching position he accepted was at the University of California, Berkeley; he would remain at UC Berkeley for the rest of his career. He specialized in spectroscopy, using Fourier-transform infrared spectroscopy to determine the traits of various molecules. He also employed Raman spectroscopy and neutron spectroscopy "to study the rotations and vibrations of molecular hydrogen embedded in various systems".
From 1976 to 2000, he was the editor of the Annual Review of Physical Chemistry. From 1995–2008, he was the Associate Dean of Undergraduate Affairs. He officially retired from Berkeley in 2003, though continued to teach until shortly before his death.
Awards and honors
In 1976, he was elected as a fellow to the American Physical Society. In 1994, he won both the Bomem-Michelson Prize for Spectroscopy and the Lippincott Award for Vibrational Spectroscopy. In 2003 he received the Berkeley Citation and Berkeley Faculty Service Award.
Personal life and death
In 1957, he met Carolyn North Cooper at a church in Manhattan during a midnight mass, despite both being Jewish. He and Carolyn had three children together. He enjoyed cycling, and commuted to and from campus each day via bicycle. Strauss died on December 2, 2014, at his home in Berkeley, California, at the age of 78.
References
1936 births
2014 deaths
People from Aachen
Jewish emigrants from Nazi Germany to the United Kingdom
Jewish emigrants from Nazi Germany to the United States
Spectroscopists
Columbia College (New York) alumni
University of California, Berkeley faculty
Annual Reviews (publisher) editors
Fellows of the American Physical Society
Columbia Graduate School of Arts and Sciences alumni | Herbert L. Strauss | [
"Physics",
"Chemistry"
] | 535 | [
"Physical chemists",
"Spectrum (physical sciences)",
"Analytical chemists",
"Spectroscopists",
"Spectroscopy"
] |
65,809,631 | https://en.wikipedia.org/wiki/Polina%20Anikeeva | Polina Olegovna Anikeeva (born 1982) is a Russian-born American materials scientist who is a Professor of Material Science & Engineering as well as Brain & Cognitive Sciences at the Massachusetts Institute of Technology (MIT). She also holds faculty appointments in the McGovern Institute for Brain Research and Research Laboratory of Electronics at MIT. Her research is centered on developing tools for studying the underlying molecular and cellular bases of behavior and neurological diseases. She was awarded the 2018 Vilcek Foundation Prize for Creative Promise in Biomedical Science, the 2020 MacVicar Faculty Fellowship at MIT, and in 2015 was named a MIT Technology Review Innovator Under 35.
Early life and education
Anikeeva was born in Saint Petersburg, Russia (then Leningrad, Soviet Union), the daughter of mechanical engineers. At 12, Anikeeva was admitted to the Physical-Technical High School. She studied biophysics at St. Petersburg State Polytechnic University, where she worked under the guidance of Tatiana Birshtein, a polymer physicist at the Institute of Macromolecular Compounds of the Russian Academy of Sciences. During her undergraduate studies she also completed an exchange program at ETH Zurich where she learned to analyze the structure of proteins using nuclear magnetic resonance spectroscopy.
After graduating in 2003, Anikeeva spent a year working in the Physical Chemistry Division at Los Alamos National Laboratory where she developed photovoltaic cells based on quantum dots (QDs). In 2004, she enrolled in the Materials Science and Engineering Ph.D. program at MIT and joined Vladimir Bulović's laboratory of organic electronics. While a graduate student, she was the lead author on a seminal paper that reported a method for generating QD light-emitting devices with electroluminescence tunable over the visible spectrum (460 nm to 650 nm). Her doctoral research was commercialized by the display industry, and acquired by a manufacturer that eventually became part of Samsung.
Research and career
Anikeeva moved to Stanford University and was appointed to Karl Deisseroth's neuroscience laboratory as a postdoctoral scholar, where she created devices for optical stimulation and recording from brain circuits. The Deisseroth laboratory pioneered Optogenetics, a technique that utilizes light-sensitive ion channels such as Channelrhodopsins to modulate neuronal activity. Anikeeva worked on combining tetrodes, electronic modalities used to record neuronal activity, with optical waveguides to create optetrodes. In Deisseroth’s lab, Anikeeva found a way to improve upon the fiber-optic probes they were using. Through her version, she incorporated multiple electrodes, allowing them to better capture neuronal signals. These optoelectronic devices could be used to record the electrical activity invoked by light delivered through the waveguide.
Anikeeva returned to Cambridge, Massachusetts as an AMAX Career Development Assistant Professor at MIT in 2011. The Anikeeva laboratory, which is also referred to as Bioelectronics@MIT, engineers tools to study and control the nervous system. By pursuing wireless technologies, Anikeeva's group has demonstrated techniques that use magnetic fields and injected nanoparticles to activate cells within mice brains.
Anikeeva's work emphasizes probing the brain with softer materials while integrating several functions into one device. Her research centers around creating a much less invasive way of stimulating brain cells. Her laboratory has two primary research priorities. The first is using the thermal drawing technique, a process originally developed for applications such as fiber optics and textiles, to create flexible polymer, fiber-based neural interfaces. In 2015, Anikeeva and co-workers first reported these flexible neural interfaces, which are also referred to as neural probes, and demonstrated that they could combine optical, electronic, and microfluidic modalities into a single implantable device for chronic interrogation of the nervous system. These fibers are a more advanced and scalable technology than their optetrode precursors. Since then, Anikeeva and her students have created more advanced neural interfaces that can be customized at their NeuroBionics lab and include materials such as photoresists and hydrogels.
Anikeeva's second main research theme is using magnetic fields to wirelessly modulate neuronal activity. Unlike light, which has a limited penetration depth in biological tissues due to attenuation, weak alternating magnetic fields (AMFs) have minimal coupling to biological tissues due to tissues' low conductivity and negligible magnetic permeability. In 2015, Anikeeva and her students demonstrated in a key paper published in Science that magneto-thermal stimulation with magnetic nanomaterials could be used for wireless deep brain stimulation. Follow up studies from the Anikeeva laboratory then extended this concept to stimulate mechanosensitive channels. Anikeeva and her colleagues have also shown that these magnetic nanomaterials can additionally be used to trigger drug delivery, hormone release, and for stimulating acid-sensing ion channels.
Current research
Anikeeva's recent work explores the brain-gut interface, advancing the fundamental neuroscience of brain-organ communication. While her previous work centered around the central nervous system, Anikeeva is now exploring communication from the peripheral nervous system.
Particularly intrigued by the signals exchanged between the brain and nervous system, Anikeeva initially focused on understanding how sensory cells in the gut influence the brain and body through neuronal communication and hormone release. Now, Anikeeva emphasizes the reciprocal communication between the body and brain involving their two-way interaction. Her team continues to regulate and explore functions that had previously been attributed solely to central neural control.
In May 2023, Anikeeva co-founded and became the scientific advisor of the NeuroBionics lab. Her first device contains 6 tungsten microelectrodes, an optical channel for optogenetics and fiber photometry, and a fluidic channel.
During the BrainMind Special Forum on Neuromodulation + BCI + AI in June 2024, Anikeeva explained how traditional sharp materials are dangerous when injected into the brain’s soft tissues. To address this, Anikeeva’s team draws inspiration from the flexibility and signal transmission capabilities of natural nerves. Anikeeva's team is already designing stiff fibers that could be threaded into the brain, as well as more delicate, rubbery fibers that are still sturdy enough for the digestive track. Much of Anikeeva's recent work emphasizes the interconnectedness of the brain and body, noting that many neurological conditions also involve gastrointestinal (GI) symptoms. However, developing therapies concerning these disorders has proven a recent challenge as it is difficult to deliver them across the blood-brain barrier. Anikeeva's recent work on magnetic stimulation has raised the possibility to avoid the barrier altogether. Her future projects aim to investigate the interplay between digestive health and these neurological conditions.
TEDx talks
Anikeeva has given TEDx talks where she discusses the technologies invented in her laboratory and neural interfaces more broadly.
"Rethinking the Brain Machine Interface," TEDxCambridge (2015). She discussed her work on neuroprosthetics and brain-machine interfaces, emphasizing her approach to match the brain's mechanical complexity through minimally-invasive materials.
"Why You Shouldn't Upload Your Brain to a Computer," TEDxCambridgeSalon (2018). She explained the distinctions between the human brain and artificial intelligence, proposing them to collaborate.
Awards and honors
2013 National Science Foundation CAREER Award
2013 National Academy of Engineering Frontiers of Engineering Symposium
2013 DARPA Young Faculty Award (YFA)
2013 Sanofi Biomedical Innovation Award
2014 Dresselhaus Foundation Inaugural Award
2014 Outstanding Faculty Undergraduate Research (UROP) Mentor, MIT
2015 Junior Bose Teaching Award, School of Engineering, MIT
2015 MIT Technology Review Top Innovators Under 35
2016 National Institutes of Health Funded Award in Multi-Site Non-Invasive Magnetothermal Excitation and Inhibition of Deep Brain Structures
2017 SPIE Women in Optics planner
2018 Vilcek Prize for Creative Promise in Biomedical Science
2019 MITx Prize for Teaching and Learning in MOOCs
2020 Margaret MacVicar Faculty Fellowship
2021 National Institutes of Health Director's Pioneer Award for Fusion of Nanomagnetic and Viral Tools to Interrogate Brain-Body Circuits
Selected publications
References
1982 births
Living people
American biotechnologists
Women biotechnologists
American materials scientists
Women materials scientists and engineers
Los Alamos National Laboratory personnel
Scientists from Saint Petersburg
Russian emigrants to the United States
Peter the Great St. Petersburg Polytechnic University alumni
MIT School of Engineering alumni
MIT School of Engineering faculty | Polina Anikeeva | [
"Materials_science",
"Technology",
"Biology"
] | 1,757 | [
"Women materials scientists and engineers",
"Women biotechnologists",
"Materials scientists and engineers",
"Biotechnologists",
"Women in science and technology"
] |
65,810,090 | https://en.wikipedia.org/wiki/NGC%204848 | NGC 4848 is a barred spiral galaxy in the constellation Coma Berenices. It is circa 340 million light-years from Earth, which, given its apparent dimensions, means that NGC 4848 is about 170,000 light years across. It was discovered by Heinrich d'Arrest on April 21, 1865. It is considered part of the Coma Cluster, which is in its northwest part. The galaxy has been stripped of its gas as it passed through the cluster.
Characteristics
NGC 4848 is a spiral galaxy viewed nearly edge-on that is classified as SBab by de Vaucouleurs. Its nucleus is active, and it has been categorised as an HII region. A number of bright HII regions form a ring around the nucleus with a radius of 5–10 arcseconds. The star formation rate is estimated to be 9 per year based on the H-alpha, ultraviolet, infrared and radio luminosity.
The galaxy distribution of hydrogen gas is asymmetrical and forms a tail pointing away from the cluster center. The tail has projected dimensions of 62.5 by 18.5 kpc and an estimated hydrogen mass of . The tail was probably formed as a result of ram pressure as the galaxy passed through the Coma Cluster and its intergalactic medium at a speed of about 1,330 km/s, starting 200 million years ago according to Fossati et al., while a previous study indicated a timeline of 400 million years. The lost hydrogen is estimated to comprise two thirds of the original hydrogen content of the galaxy. A few star-forming regions, probably HII regions, are in the tail.
A dwarf galaxy may cross the disk of NGC 4848; however, its mass is too low to be a source of the hydrogen tail.
See also
NGC 4921, a spiral galaxy in the Coma Cluster that has lost its hydrogen
References
External links
Barred spiral galaxies
Coma Cluster
Coma Berenices
4848
08082
44405
Galaxies discovered in 1865
Astronomical objects discovered in 1865
Discoveries by Heinrich Louis d'Arrest
+05-31-039 | NGC 4848 | [
"Astronomy"
] | 425 | [
"Coma Berenices",
"Constellations"
] |
65,810,190 | https://en.wikipedia.org/wiki/Neural%20Engine | Neural Engine is a series of AI accelerators designed for machine learning by Apple. The first SoC including Neural Engine is Apple A11 Bionic for iPhone 8, 8 Plus and iPhone X introduced in 2017. Since then, all Apple A series SoCs have Neural Engine. In 2020, Apple introduced the Apple M1 for Mac and all Apple M series SoCs have Neural Engine.
Apple has stated the Neural Engine in the M4 can perform 38 trillion operations per second (TOPS), an improvement over the 18 TOPS in the M3.
Applications
The Neural Engine is used for real-time AI-driven applications such as Face ID, Siri, and augmented reality (AR). It also handles computational photography features, including Smart HDR and Night Mode, by processing vast amounts of sensor data for real-time image enhancements.
Energy efficiency and privacy
The Neural Engine also provides high energy efficiency, allowing real-time AI tasks to be performed with minimal battery consumption. Its on-device processing ensures that sensitive tasks such as facial recognition and voice commands are handled locally, enhancing privacy by keeping user data secure.
Developer tools
The Neural Engine is fully integrated with Apple’s Core ML framework, which allows developers to run machine learning models on-device. This integration supports applications like object recognition, natural language processing, and gesture detection, giving developers the tools to harness AI power efficiently.
References
Application-specific integrated circuits
AI accelerators
Coprocessors
Computer optimization
Gate arrays | Neural Engine | [
"Technology",
"Engineering"
] | 294 | [
"Computer engineering",
"Computer performance",
"Gate arrays",
"Application-specific integrated circuits",
"Computer optimization"
] |
65,810,863 | https://en.wikipedia.org/wiki/Positioning%20theory | Positioning theory is a theory in social psychology that characterizes interactions between individuals. "Position" can be defined as an alterable collection of beliefs of an individual with regards to their rights, duties, and obligations. "Positioning" is the mechanism through which roles are assigned or denied, either to oneself or others. The theory describes malleable roles and storylines that determine the boundaries of future acts and the meanings of what people say and do. The theory expands upon the work of psychologist Lev Vygotsky, especially his theory of zone of proximal development (ZPD). It emphasizes the interdependence of positions, speech and other acts, and storylines that arise from them; a change in any one aspect affects the other two. The theory provides a framework to understand a person's specific behavior by considering social, individual, and moral factors.
There are three orders of positioning based on how positions are assumed: first-, second- and third-order positioning. Positioning can also be classified into various types depending on the specifics of the situation; these include self, other, tacit, intentional, interactive, reflexive, moral, personal, indirect, and malignant positioning. Positioning theory originated in the 1990s from Positioning: the discursive production of selves, which looked to solve a problem that arose "out of a discussion about the problems inherent in the use of the concept of role in developing a social psychology of selfhood". Since its inception, Positioning theory has been developed further with contributions from Bronwyn Davies, Rom Harré, Luk Van Langenhove, and Fathali Moghaddam. The theory has provided a structure for social discourse analysis, and it has been used to study various social situations. Its application has extended into fields such as education, anthropology, communication, and political science.
Overview
Positioning theory provides a framework to comprehend why individuals choose to act with one specific behavior or a narrowed set of behaviors out of the many possible behaviors before them. "Positions" are a collection of specific beliefs that individuals have in context of rights, duties and obligations. They are open to change (compared to "roles" which are fixed) and constitute a basic foundation in helping an individual determine how to behave in a certain way. "Positioning" pertains to the mechanisms by which roles are assigned, appropriated or denied; it also involves the forms in which individuals build themselves and others through discursive activities, such as oral and written expression, usage of language, speech, and other actions based on normative and moral systems. The opportunities for people to act depend on numerous other people. In order to perform tasks, individuals use their own cognitive capabilities as well as the capabilities of others.
Researchers have studied the narratives used by individuals to position themselves and others. These studies specifically look at how positions are assumed by individuals (for themselves and others) based on their interpretation of "rights" (what a person is owed by others) and "duties" (what a person owes to others). The theory involves conventions of speech and action that are changeable, questionable, and short-lived. This is in contrast to role theory, in which roles are relatively fixed and static. The theory can be used to investigate how an individual constructs their story, and therein their sense of self, the social acts (including speech) represented in and through their story, and the positions that they reveal.
Relation to Lev Vygotsky's theories
Rom Harré and Fathali Moghaddam suggest that positioning theory adds to the work of earlier theorists like Lev Vygotsky. Positioning theory is explicitly consistent with Vygotskian approaches to learning and teaching, and is applicable to educational research with its emphasis on individual and social attributes. Vygotsky theorized that positive social support can lead to an individual attaining higher mental functioning. In Vygotsky's zone of proximal development (ZPD), a learner can increase their performance on tasks when given support by adults or when collaborating with their peers. Harré and Moghaddam explain that positioning theory can fill the "gap" in Vygotsky's work by emphasizing the variability of positions that come about in a group that might be supporting that learner.
Positioning theory highlights the individual and knowledge of the participants in the education context. In such contexts, role and position can seem to overlap and many see positioning as another way of explaining someone's role. The constructs are quite different, as a role is static and a position changes depending on the context. Davies and Harré explain this difference with an example of the role of a "mother". There is a general understanding of the role that a mother plays in someone's life, but what is missing is the internalized understanding of "mother" to each individual person that plays that role. That is, each person has a unique lived experience that affects his or her position. One may anticipate becoming a mother, or one may never be in this position. Additionally, the person could have a strong or poor relationship with their own mother. There is a history of narratives out of each lived experience that determine one's position towards the idea of "mother". This can be applied in educational contexts when looking at the difference between the "role" of a teacher as opposed to the "position" of a teacher.
Individual and social attributes
The positioning triangle
A diagram can be used to explain the social significance of positioning acts. All corners of the triangle are intertwined; in other words, if one part of the triangle changes, then the other parts change (e.g., changing the storyline would affect both the position and speech-act). Harré and Luk Van Langenhove explain that what people can do is a function of "the capacities of people to do certain things", "the restrictions imposed upon people to do certain things", and "the intentions that people have to do certain things."
Position
Harré and Moghaddam expand upon the idea that position has both social and individual components. Harré describes "position" as "a cluster of short-term disputable rights, obligations and duties" of a person in various social contexts. These rights, duties and obligations are carried through by the characteristics and personality traits of the individual. Traditions and customs are vital sources in the formation of positions. In sum, a position establishes what an individual is authorized to say or do.
Speech and other acts
Each socially meaningful action, intended movement, or speech should be seen as an act of significance. Jumping is an example of an intended action. An individual may be performing this action to jump over an object, follow a physical education instructor, exercise, or model the movement for another person to copy. This action is only important if it is identified under rules for accepted moral or social behaviors, and given meaning under the context in which it is performed. An appropriate situation (for instance, a class of physical education) and meaningful and relevant actions (for example, an instructor showing how to jump) must come prior to the action performed (jumping by the student). There will also be consequences to the performed action (such as being graded on their ability to jump). While one speech act cannot cause another speech act to take place, it can lead to the development of storylines where new positions and other speech acts occur, and can give meaning and accountability to those other speech acts.
Storyline
As a result of speech and other acts, storylines are developed. These social episodes come about as an individual and those around them contribute to a pattern of narratives. The storylines can be seen as who has or does not have a right or a duty to act, and how they may act. When explaining a story, one's position may result in alluding to themselves as a hero, whereas another individual may have a different storyline that positions the same person as a villain. Hence, a change in the storyline could alter the initial positions of the involved individuals. Whilst individuals are conversing with one another, they can use narratives or storylines to have their actions and words be purposeful and significant to themselves as well as others.
Moral dimension
All social structures can be seen as moral orders that set forward rules for acceptable behavior. Speech acts create and activate moral orders. The capacity of individuals to act independently is derived from possibilities for them to behave against certain moral orders or to establish new moral orders. When an individual performs an action, they develop a personal moral order (e.g., justifying one's own behavior that one would otherwise deem as irresponsible or inappropriate). Personal moral orders can sometimes be seen as stronger than moral orders that are set in place for all people to follow.
Social situations
Positioning theory brings about the analysis of any social situation as it relates to these three notions:
There are many cultural, legal and institutional moral orders that are pre-determined and assign positions to the individuals (actors). These positions bring about powers and rights that are given to these individuals.
There are expanding and emerging storylines that make up a local moral order where the beginning positions can be confirmed or transformed.
There are personal moral orders of the individuals involved that impact what they will do and say, like refuting and accepting pre-determined positions or the positions developed through conversation.
Personhood
Positioning theory focuses on two aspects of personhood:
Embodied self: Singular, continuous and self-identical. It is the unity and continuity of a person's point of view and their actions in various contexts.
Self concept: Beliefs that individuals have about themselves, their moral qualities, their abilities, their fears, and their life. This expands into the sub-concepts of autobiographical self and social self.
A. Autobiographical self: A form of narrative self-understanding. Autobiographical selves can alter from story to story because of differences based on the audience and the situation in which the person is discussing their story.
B. Social self: The qualities and traits that an individual displays when they have interactions with others. A person's social self will vary based on context.
Types of positioning
Orders of positioning
First-order positioning refers to the position an individual assumes, independent of any influence. Second-order positioning refers to changes in first-order positioning from interactions with others in a social environment. In third-order positioning, individuals outside the social environment are influenced by previous social interactions and assume positions based on what they have observed.
Self and other positioning
Self positioning includes how a person positions themselves, while other positioning is how an individual positions others. They are codependent; in order to position oneself, positions of others would need to be defined, and vice versa.
Tacit and intentional positioning
Tacit positioning is involved in everyday interactions, usually of the first order of positioning, and unintentional in nature. It constitutes what has been inherently learnt and internalized over time. Intentional positioning includes positions that are consciously assumed; depending on the end goal of the assumed position, it can be classified into four parts:
Deliberate self positioning: A person assumes a specific position with the intention of portraying something in a particular manner, regardless of its factual accuracy, in order to achieve a specific outcome or strategy.
Forced self positioning: This occurs in response to an external event and is more of an obligatory response compared to a deliberate one. For example, an individual positions themselves in a particular way in response to an annual performance appraisal.
Deliberate positioning of others: In this type of positioning, an individual deliberately positions others to accomplish an underlying goal. Deliberate positioning of others can happen with or without the target individual or individuals present in the social environment. A speaker including their audience in their speech is an example for the former, while gossiping would be an instance of the latter.
Forced positioning of others: This occurs when there are external factors present which require an individual to assume specific positions for others. For instance, a person under oath in a trial is required by law to assume positions of others.
Interactive and reflexive positioning
Interactive positioning is exhibited when a person or a group of people position another person based on their behavior and what they say. Reflexive positioning is the positioning of oneself in response to others. Davies and Harré use an example of an interaction between a student and a principal to illustrate both concepts: when a student is caught wearing a hat in the school, the principal asks the student to take it off, but the student refuses to do so and receives a two-day suspension. The principal engaged in interactive positioning toward the student when he asked the student to remove his hat and positioned him as rebellious. The student demonstrated reflexive positioning when he refused to comply. Davies and Harré suggested that storylines or positions that arise from specific interactions can sometimes carry forward to unrelated storylines in the future (for instance, the student may continue to be positioned as rebellious by the principal in future interactions that are unrelated to the past interaction).
Moral and personal positioning
Moral positioning occurs when one behaves in accordance with the rights, duties, and obligations of their role. These positions may be in the form of professor-student, parent-child, or grocery clerk-customer; a particular role results in an individual acting and responding in a certain way. Personal positioning happens based on one's individual properties and life experiences, and does not conform to a generic or expected role. For instance, a person who has studied the law might represent himself in court even without a law degree.
Indirect positioning
Indirect positioning can be seen as the use of characteristics to position an individual, favorably or unfavorably, with relation to oneself and one's own group desires. An example of this could be positioning oneself as "stupid", which might restrict that person from correcting their cognitive performance (pertaining to specific tasks) beyond a certain level. This could also be positioning someone as "irresponsible", which could result in that individual being excluded by their social group from taking on tasks which would require a certain level of responsibility. Harré and Moghaddam use an example of indirect positioning in regard to a leader of a nation being used to position the overall nation itself (e.g., Europe using the phrase "The Cowboy President" in reference to George W. Bush while also indirectly positioning the United States as an ignorant nation).
Malignant or malevolent positioning
Malignant or malevolent positioning is when the discourse about an individual causes others to portray that person in a negative light and treat them poorly as a result. One may hold a critical view of a person with a disability, for example, while being unaware of this biased perspective.
History
Positioning theory originated from gender studies in the 1980s. Bronwyn Davies, professor of education at the University of Western Sydney, drew from feminist scholars to expand upon subjectivity, storyline, and narrative in positioning theory. Subsequently, Rom Harré, Luk Van Langenhove, and Fathali Moghaddam contributed to development of the theory in its early stages. Harré and Van Langenhove introduced conceptual refinements to the theory, including differences between first- and second-order positions, moral and personal positioning, tacit and intentional positioning, as well as self and other positioning.
The theory has become a framework for social discourse analysis and is used to study various social situations. Although the theory is rooted in social psychology, it has been used in fields like education, anthropology, communication studies, workplace agency, political identity studies, and public relations and strategic communication.
See also
Cultural-historical activity theory
Social constructionism
Social constructivism
References
Behavioral concepts
Interpersonal communication
Social constructionism | Positioning theory | [
"Biology"
] | 3,170 | [
"Behavior",
"Behavioral concepts",
"Behaviorism"
] |
65,810,916 | https://en.wikipedia.org/wiki/BD%2B00%20316 | BD+00 316 is an ordinary star with a close-orbiting planetary companion in the equatorial constellation of Cetus. It is also known as WASP-71 since 2019; BD+00 316 is the stellar identifier from the Bonner Durchmusterung catalogue. With an apparent visual magnitude of 10.56, it is too faint to be visible to the naked eye. This star is located at a distance of 1,160 light-years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 7.7 km/s.
This is classified as an F-type star with a stellar classification of F8. It is more than double the diameter of the Sun with 1.5 times the Sun's mass. The star is younger than the Sun at about 3.6 billion years, yet is already evolving away from the main sequence. BD+00 316 is enriched in heavy elements, having 140% of the solar abundance of iron. Imaging surveys in 2015 and 2020 failed to find any stellar companions for BD+00 316.
The star was named Mpingo by Tanzanian amateur astronomers in 2020 as part of the NameExoWorlds contest, after the mpingo tree (Dalbergia melanoxylon) whose wood is a type of ebony used in musical instruments.
Planetary system
In 2012 a transiting superjovian planet, designated component b, was detected on a tight, circular orbit. The planetary orbit is well aligned with the equatorial plane of the star, the misalignment angle being equal to −1.9°. Its equilibrium temperature is 2,016.1 K.
The planet was named Tanzanite by Tanzanian amateur astronomers in 2020 as part of the NameExoWorlds contest, after the mineral also known as tanzanite.
References
F-type stars
Planetary systems with one confirmed planet
Planetary transit variables
Cetus
J01570320+0045318
Durchmusterung objects
Mpingo | BD+00 316 | [
"Astronomy"
] | 416 | [
"Cetus",
"Constellations"
] |
65,811,071 | https://en.wikipedia.org/wiki/Hunter%20Lab | Hunter Lab (also known as Hunter L,a,b) is a color space defined in 1948 by Richard S. Hunter.
It was designed to be computed via simple formulas from the CIEXYZ space, but to be more perceptually uniform. Hunter named his coordinates L, a and b.
Hunter Lab was a precursor to CIELAB, created in 1976 by the International Commission on Illumination (CIE), which named the coordinates for CIELAB as L*, a*, b* to distinguish them from Hunter's coordinates.
Formulation
L is a correlate of lightness and is computed from the Y tristimulus value using Priest's approximation to Munsell value:
where Yn is the Y tristimulus value of a specified white object. For surface-color applications, the specified white object is usually (though not always) a hypothetical material with unit reflectance that follows Lambert's law. The resulting L will be scaled between 0 (black) and 100 (white); roughly ten times the Munsell value. Note that a medium lightness of 50 is produced by a luminance of 25, due to the square root proportionality.
a and b are termed opponent color axes. a represents, roughly, Redness (positive) versus Greenness (negative). It is computed as:
where Ka is a coefficient that depends upon the illuminant (for D65, Ka is 172.30; see approximate formula below) and Xn is the X tristimulus value of the specified white object.
The other opponent color axis, b, is positive for yellow colors and negative for blue colors. It is computed as:
where Kb is a coefficient that depends upon the illuminant (for D65, Kb is 67.20; see approximate formula below) and Zn is the Z tristimulus value of the specified white object.
Both a and b will be zero for objects that have the same chromaticity coordinates as the specified white objects (i.e., achromatic, grey, objects).
Approximate formulas for Ka and Kb
In the previous version of the Hunter Lab color space, Ka was 175 and Kb was 70. Hunter Associates Lab discovered that better agreement could be obtained with other color difference metrics, such as CIELAB (see above) by allowing these coefficients to depend upon the illuminants. Approximate formulae are:
which result in the original values for Illuminant C, the original illuminant with which the Lab color space was used.
As an Adams chromatic valence space
Adams chromatic valence color spaces are based on two elements: a (relatively) uniform lightness scale and a (relatively) uniform chromaticity scale. If we take as the uniform lightness scale Priest's approximation to the Munsell Value scale, which would be written in modern notation as:
and, as the uniform chromaticity coordinates:
where ke is a tuning coefficient, we obtain the two chromatic axes:
and
which is identical to the Hunter Lab formulas given above if we select and . Therefore, the Hunter Lab color space is an Adams chromatic valence color space.
References
Color space
1948 introductions | Hunter Lab | [
"Mathematics"
] | 658 | [
"Color space",
"Space (mathematics)",
"Metric spaces"
] |
65,812,954 | https://en.wikipedia.org/wiki/Tobias%20Feilner | Tobias Christoph Feilner (19 May 1773, Weiden in der Oberpfalz - 7 April 1839, Berlin) was a German master potter. He also manufactured bricks, terracotta, molded stones and masonry heaters.
Biography
He was the third of ten children born to the master potter and city councilor, Philipp Heinrich Feilner. He learned the pottery trade from his father and left home in 1791, initially settling in Mannheim. There, he met his great uncle, , who had been Director of the Frankenthal Porcelain Factory since 1775. The knowledge thus gained enabled him to find work at the faience factories in
Alzey, Rheinhessen and Kurmainz. From 1792 to 1793, he worked for the master potter, Christian Leberecht Thomas, in Dresden.
With the assistance of Friedrich Abraham Wilhelm von Arnim (1767–1812), the Prussian Ambassador to Saxony, he was able to find a permanent position with Gottfried Höhler (1744-1812), who ran a furnace workshop in Berlin. He started there as a modeller, but was soon promoted to technical Foreman. In 1804, Feilner received a Royal Patent for an encaustic painting technique; used to create precise decorations on pottery and tiles. Höhler then made him a partner; leaving the business entirely in 1809. Following Höhler's death, the company became his.
In 1817, he expanded the company with a new factory building, and increased his workforce to 120 employees. He began producing terracotta in 1819. His products were used on the Friedrichswerder Church, the Old Palace, and the Church of Peace, Potsdam. Together with Karl Friedrich Schinkel, he developed a type of masonry heater that became standard in Germany by the middle of the 19th century. His heaters may still be seen at Schloss Tegel and Schloss Friedenstein, among many others. Some were sold in London, Rome and St. Petersburg. Until 1850, his company was the largest manufacturer of heaters in Germany. He was the teacher of another well known master potter, Ernst March. As a member of numerous trade and commercial organizations, he was also involved in civic affairs.
He married Charlotte Sophie Pausewang in 1800 and they had five children. Only two daughters survived to adulthood, however. One of them, Amalie, married the sculptor Ludwig Wilhelm Wichmann, who provided Feilner with numerous models for his terracotta work.
He died at the age of sixty-five and was interred at the . His grave has not been preserved. In 1848, on the initiative of King Frederick William IV, the street where his factory was located was renamed the "Feilnerstraße".
References
Further reading
Jan Mende: "Feilner nach Feilner. Die Tonwarenfabrik unter den Nachfolgern Tobias Feilners". In: Jahrbuch Stiftung Stadtmuseum Berlin. 9, Berlin 2003, pps.167–184.
Jan Mende: "Eisen und Terrakotta. Technische und künstlerische Parallelen". In: Charlotte Schreiter, Albrecht Pyritz (Eds.): Berliner Eisen. Die Königliche Eisengießerei Berlin. Zur Geschichte eines preußischen Unternehmens. Hannover 2007, , pps.171–186.
Jan Mende: Die Tonwarenfabrik Tobias Chr. Feilner in Berlin. Kunst und Industrie im Zeitalter Schinkels. Berlin/München 2013,
External links
1773 births
1839 deaths
German potters
Brick manufacturers
Terracotta
Manufacturer of architectural terracotta
People from Weiden in der Oberpfalz
18th-century German artisans | Tobias Feilner | [
"Engineering"
] | 779 | [
"Manufacturer of architectural terracotta",
"Architecture"
] |
65,813,793 | https://en.wikipedia.org/wiki/List%20of%20Solanales%20of%20South%20Africa | Solanales is an order of flowering plants, included in the asterid group of dicotyledons. The anthophytes are a grouping of plant taxa bearing flower-like reproductive structures. They were formerly thought to be a clade comprising plants bearing flower-like structures. The group contained the angiosperms - the extant flowering plants, such as roses and grasses - as well as the Gnetales and the extinct Bennettitales.
23,420 species of vascular plant have been recorded in South Africa, making it the sixth most species-rich country in the world and the most species-rich country on the African continent. Of these, 153 species are considered to be threatened. Nine biomes have been described in South Africa: Fynbos, Succulent Karoo, desert, Nama Karoo, grassland, savanna, Albany thickets, the Indian Ocean coastal belt, and forests.
The 2018 South African National Biodiversity Institute's National Biodiversity Assessment plant checklist lists 35,130 taxa in the phyla Anthocerotophyta (hornworts (6)), Anthophyta (flowering plants (33534)), Bryophyta (mosses (685)), Cycadophyta (cycads (42)), Lycopodiophyta (Lycophytes(45)), Marchantiophyta (liverworts (376)), Pinophyta (conifers (33)), and Pteridophyta (cryptogams (408)).
Four families are represented in the literature. Listed taxa include species, subspecies, varieties, and forms as recorded, some of which have subsequently been allocated to other taxa as synonyms, in which cases the accepted taxon is appended to the listing. Multiple entries under alternative names reflect taxonomic revision over time.
Convolvulaceae
Family: Convolvulaceae,
Astripomoea
Genus Astripomoea:
Astripomoea malvacea (Klotzsch) A.Meeuse, indigenous
Astripomoea malvacea (Klotzsch) A.Meeuse var. malvacea, indigenous
Astrochlaena rotundata Pilg. accepted as Astripomoea rotundata (Pilg.) A.Meeuse
Bonamia
Genus Bonamia:
Bonamia schizantha (Hallier f.) A.Meeuse, accepted as Seddera schizantha Hallier f.
Bonamia velutina Verdc. indigenous
Calystegia
Genus Calystegia:
Calystegia sepium (L.) R.Br. not indigenous, naturalised
Calystegia soldanella (L.) R.Br. ex Roem. & Schult. not indigenous, naturalised
Convolvulus
Genus Convolvulus:
Convolvulus arvensis L. not indigenous, naturalised, invasive
Convolvulus aschersonii Engl. indigenous
Convolvulus bidentatus Bernh. ex C.Krauss, endemic
Convolvulus boedeckerianus Peter, endemic
Convolvulus capensis Burm.f. endemic
Convolvulus capensis Burm.f. var. bowieanus (Rendle) A.Meeuse, accepted as Convolvulus capensis Burm.f. present
Convolvulus capensis Burm.f. var. plicatus (Desr.) Baker, accepted as Convolvulus capensis Burm.f. present
Convolvulus dregeanus Choisy, endemic
Convolvulus farinosus L. indigenous
Convolvulus galpinii C.H.Wright, endemic
Convolvulus indicus Burm.f. accepted as Ipomoea indica (Burm.f.) Merr. present
Convolvulus malabaricus L. accepted as Hewittia malabarica (L.) Suresh, present
Convolvulus multifidus Thunb. endemic
Convolvulus natalensis Bernh. ex Krauss, indigenous
Convolvulus natalensis Bernh. ex Krauss var. transvaalensis (Schltr.) A.Meeuse, accepted as Convolvulus natalensis Bernh. ex Krauss, present
Convolvulus ocellatus Hook.f. indigenous
Convolvulus ocellatus Hook.f. var. ocellatus, indigenous
Convolvulus ocellatus Hook.f. var. ornatus (Engl.) A.Meeuse, accepted as Convolvulus ocellatus Hook.f. var. ocellatus, present
Convolvulus sagittatus Thunb. indigenous
Convolvulus sagittatus Thunb. subsp. grandiflorus (Hallier f.) A.Meeuse var. graminifolius, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. subsp. grandiflorus (Hallier f.) A.Meeuse var. grandiflorus, accepted as Convolvulus sagittatus Thunb.
Convolvulus sagittatus Thunb. subsp. grandiflorus (Hallier f.) A.Meeuse var. linearifolius, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. subsp. sagittatus var. hirtellus, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. subsp. sagittatus var. namaquensis, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. subsp. sagittatus var. phyllosepalus, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. subsp. sagittatus var. ulosepalus, accepted as Convolvulus sagittatus Thunb. present
Convolvulus sagittatus Thunb. var. aschersonii (Engl.) Verdc. accepted as Convolvulus aschersonii Engl. present
Convolvulus sublobatus L.f. accepted as Hewittia malabarica (L.) Suresh, present
Convolvulus thunbergii Roem. & Schult. indigenous
Cuscuta
Genus Cuscuta:
Cuscuta africana Willd. endemic
Cuscuta angulata Engelm. endemic
Cuscuta appendiculata Engelm. endemic
Cuscuta australis R.Br. indigenous
Cuscuta bifurcata Yunck. endemic
Cuscuta campestris Yunck. not indigenous, naturalised, invasive
Cuscuta cassytoides Engelm. indigenous
Cuscuta epithymum Murray, not indigenous, naturalised
Cuscuta gerrardii Baker, endemic
Cuscuta hyalina Roth, indigenous
Cuscuta kilimanjari Oliv. indigenous
Cuscuta kilimanjari Oliv. var. kilimanjari, indigenous
Cuscuta natalensis Baker, endemic
Cuscuta nitida Choisy, endemic
Cuscuta planiflora Ten. indigenous
Cuscuta planiflora Ten. var. madagascarensis (Yunck.) Verdc. indigenous
Cuscuta planiflora Ten. var. planiflora, indigenous
Cuscuta suaveolens Ser. not indigenous, naturalised, invasive
Dichondra
Genus Dichondra:
Dichondra micrantha Urb. not indigenous, naturalised
Evolvulus
Genus Evolvulus :
Evolvulus alsinoides (L.) L. indigenous
Evolvulus alsinoides (L.) L. var. linifolius (L.) Baker, accepted as Evolvulus alsinoides (L.) L. present
Evolvulus nummularius (L.) L. indigenous
Falkia
Genus Falkia:
Falkia oblonga Bernh. ex C.Krauss, indigenous
Falkia repens Thunb. endemic
Hewittia
Genus Hewittia:
Hewittia malabarica (L.) Suresh, indigenous
Hewittia sublobata (L.f.) Kuntze, accepted as Hewittia malabarica (L.) Suresh, present
Ipomoea
Genus Ipomoea:
Ipomoea adenioides Schinz, indigenous
Ipomoea adenioides Schinz var. adenioides, indigenous
Ipomoea alba L. not indigenous, naturalised, invasive
Ipomoea albivenia (Lindl.) Sweet, indigenous
Ipomoea aquatica Forssk. indigenous
Ipomoea arachnosperma Welw. accepted as Ipomoea dichroa Choisy, present
Ipomoea atherstonei Baker, accepted as Ipomoea oblongata E.Mey. ex Choisy, present
Ipomoea bathycolpos Hallier f. endemic
Ipomoea bathycolpos Hallier f. var. sinuatodentata Hallier f. accepted as Ipomoea bathycolpos Hallier f. present
Ipomoea bisavium A.Meeuse, endemic
Ipomoea bolusiana Schinz, indigenous
Ipomoea bolusiana Schinz var. pinnatipartita Verdc. accepted as Ipomoea bolusiana Schinz, present
Ipomoea cairica (L.) Sweet, indigenous
Ipomoea cairica (L.) Sweet var. cairica, indigenous
Ipomoea carnea Jacq. subsp. fistulosa (Mart. ex Choisy) D.F.Austin, not indigenous, naturalised, invasive
Ipomoea chloroneura Hallier f. indigenous
Ipomoea congesta R.Br. accepted as Ipomoea indica (Burm.f.) Merr. present
Ipomoea consimilis Schulze-Menz, indigenous
Ipomoea coptica (L.) Roth ex Roem. & Schult. indigenous
Ipomoea coscinosperma Hochst. ex Choisy, indigenous
Ipomoea crassipes Hook. indigenous
Ipomoea crassipes Hook. var. crassipes, indigenous
Ipomoea crispa (Thunb.) Hallier f. endemic
Ipomoea dichroa Choisy, indigenous
Ipomoea eriocarpa R.Br. indigenous
Ipomoea ficifolia Lindl. indigenous
Ipomoea fistulosa Mart. ex Choisy, accepted as Ipomoea carnea Jacq. subsp. fistulosa (Mart. ex Choisy) D.F.Austin, not indigenous, naturalised
Ipomoea gracilisepala Rendle, indigenous
Ipomoea hackeliana (Schinz) Hallier f. indigenous
Ipomoea hederifolia L. not indigenous, cultivated, naturalised, invasive
Ipomoea hochstetteri House, indigenous
Ipomoea holubii Baker, indigenous
Ipomoea indica (Burm.f.) Merr. not indigenous, naturalised, invasive
Ipomoea involucrata P.Beauv. indigenous
Ipomoea involucrata P.Beauv. var. involucrata, indigenous
Ipomoea lapathifolia Hallier f. indigenous
Ipomoea lapathifolia Hallier f. var. lapathifolia, indigenous
Ipomoea magnusiana Schinz, indigenous
Ipomoea magnusiana Schinz var. eenii (Rendle) A.Meeuse, accepted as Ipomoea magnusiana Schinz, present
Ipomoea mauritiana Jacq. indigenous
Ipomoea nil (L.) Roth, not indigenous, naturalised
Ipomoea oblongata E.Mey. ex Choisy, indigenous
Ipomoea obscura (L.) Ker Gawl. indigenous
Ipomoea obscura (L.) Ker Gawl. var. fragilis (Choisy) A.Meeuse, accepted as Ipomoea obscura (L.) Ker Gawl. var. obscura, present
Ipomoea obscura (L.) Ker Gawl. var. obscura, indigenous
Ipomoea oenotherae (Vatke) Hallier f. indigenous
Ipomoea oenotherae (Vatke) Hallier f. var. oenotherae, indigenous
Ipomoea oenotheroides (L.f.) Raf. ex Hallier f. indigenous
Ipomoea ommanneyi Rendle, indigenous
Ipomoea papilio Hallier f. indigenous
Ipomoea pellita Hallier f. indigenous
Ipomoea pes-caprae (L.) R.Br. indigenous
Ipomoea pes-caprae (L.) R.Br. subsp. brasiliensis (L.) Ooststr. indigenous
Ipomoea pes-tigridis L. indigenous
Ipomoea pes-tigridis L. var. pes-tigridis, indigenous
Ipomoea pileata Roxb. indigenous
Ipomoea plebeia R.Br. indigenous
Ipomoea plebeia R.Br. subsp. africana A.Meeuse, indigenous
Ipomoea purpurea (L.) Roth, not indigenous, naturalised, invasive
Ipomoea quinquefolia Hochst. ex Hallier f. var. purpurea Hallier f. accepted as Ipomoea hochstetteri House
Ipomoea robertsiana Rendle, endemic
Ipomoea shirambensis Baker, indigenous
Ipomoea simplex Thunb. indigenous
Ipomoea sinensis (Desr.) Choisy, indigenous
Ipomoea sinensis (Desr.) Choisy subsp. blepharosepala (Hochst. ex A.Rich.) Verdc. ex A.Meeuse, indigenous
Ipomoea stenosiphon Hallier f. indigenous
Ipomoea suffruticosa Burch. indigenous
Ipomoea tenuipes Verdc. indigenous
Ipomoea transvaalensis A.Meeuse, indigenous
Ipomoea wightii (Wall.) Choisy, indigenous
Ipomoea wightii (Wall.) Choisy var. wightii, indigenous
Ipomoea woodii N.E.Br. accepted as Stictocardia laxiflora (Baker) Hallier f. present
Jacquemontia
Genus Jacquemontia:
Jacquemontia tamnifolia (L.) Griseb. indigenous
Merremia
Genus Merremia:
Merremia kentrocaulos (C.B.Clarke) Rendle, indigenous
Merremia malvaefolia Rendle, endemic
Merremia palmata Hallier f. indigenous
Merremia pinnata (Hochst. ex Choisy) Hallier f. indigenous
Merremia pterygocaulos (Choisy) Hallier f. indigenous
Merremia tridentata (L.) Hallier f. subsp. angustifolia (Jacq.) Ooststr. var. angustifolia, accepted as Xenostegia tridentata (L.) D.F.Austin & Staples subsp. angustifolia (Jacq.) Lejoly & Lisowski, present
Merremia verecunda Rendle, indigenous
Paralepistemon
Genus Paralepistemon:
Paralepistemon shirensis (Oliv.) Lejoly & Lisowski, indigenous
Poranopsis
Genus Poranopsis:
Poranopsis paniculata (Roxb.) Roberty, not indigenous, cultivated, naturalised
Seddera
Genus Seddera:
Seddera capensis (E.Mey. ex Choisy) Hallier f. indigenous
Seddera suffruticosa (Schinz) Hallier f. indigenous
Stictocardia
Genus Stictocardia:
Stictocardia laxiflora (Baker) Hallier f. indigenous
Stictocardia laxiflora (Baker) Hallier f. var. woodii (N.E.Br.) Verdc. accepted as Stictocardia laxiflora (Baker) Hallier f. present
Stictocardia woodii (N.E.Br.) Hallier f. accepted as Stictocardia laxiflora (Baker) Hallier f. present
Turbina
Genus Turbina:
Turbina holubii (Baker) A.Meeuse, accepted as Ipomoea holubii Baker, present
Turbina oblongata (E.Mey. ex Choisy) A.Meeuse, accepted as Ipomoea oblongata E.Mey. ex Choisy, present
Turbina oenotheroides (L.f.) A.Meeuse, accepted as Ipomoea oenotheroides (L.f.) Raf. ex Hallier f. present
Turbina robertsiana (Rendle) A.Meeuse, accepted as Ipomoea robertsiana Rendle, present
Turbina shirensis (Oliv.) A.Meeuse, accepted as Paralepistemon shirensis (Oliv.) Lejoly & Lisowski, present
Turbina stenosiphon (Hallier f.) A.Meeuse, accepted as Ipomoea stenosiphon Hallier f. present
Turbina suffruticosa (Burch.) A.Meeuse, accepted as Ipomoea suffruticosa Burch. present
Xenostegia
Genus Xenostegia:
Xenostegia tridentata (L.) D.F.Austin & Staples, indigenous
Xenostegia tridentata (L.) D.F.Austin & Staples subsp. angustifolia (Jacq.) Lejoly & Lisowski, indigenous
Montiniaceae
Family: Montiniaceae,
Montinia
Genus Montinia:
Montinia caryophyllacea Thunb. indigenous
Solanaceae
Family: Solanaceae,
Atropa
Genus Atropa:
Atropa solanacea L. accepted as Solanum guineense L. indigenous
Brugmansia
Genus Brugmansia:
Brugmansia arborea (L.) Lagerh. not indigenous, cultivated, naturalised
Capsicum
Genus Capsicum:
Capsicum annuum L. not indigenous, naturalised
Capsicum annuum L. var. aviculare (Dierb.) D'Arcy & Eshbaugh, accepted as Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill, not indigenous, cultivated
Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill, not indigenous, naturalised
Capsicum frutescens L. not indigenous, naturalised
Capsicum hispidum Dunal var. glabriusculum Dunal, accepted as Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill, unconfirmed
Capsicum indicum Dierb. var. aviculare Dierb. accepted as Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill
Cestrum
Genus Cestrum:
Cestrum aurantiacum Lindl. not indigenous, naturalised, invasive
Cestrum elegans (Brongn.) Schltdl. not indigenous, naturalised, invasive
Cestrum laevigatum Schltdl. not indigenous, naturalised, invasive
Cestrum parqui L'Her. not indigenous, naturalised, invasive
Cyphomandra
Genus Cyphomandra:
Cyphomandra betacea (Cav.) Sendtn. accepted as Solanum betaceum Cav. not indigenous, naturalised
Cyphomandra sp. accepted as Solanum sp.
Datura
Genus Datura:
Datura ferox L. not indigenous, naturalised, invasive
Datura innoxia Mill. accepted as Datura innoxia Mill. not indigenous, naturalised, invasive
Datura innoxia Mill. not indigenous, naturalised
Datura metel L. not indigenous, naturalised
Datura stramonium L. not indigenous, naturalised, invasive
Lycium
Genus Lycium:
Lycium acutifolium E.Mey. ex Dunal, endemic
Lycium afrum L. endemic
Lycium amoenum Dammer, indigenous
Lycium arenicola Miers, indigenous
Lycium bosciifolium Schinz, indigenous
Lycium cinereum Thunb. indigenous
Lycium cordatum Mill. accepted as Carissa bispinosa (L.) Desf. ex Brenan, indigenous
Lycium ferocissimum Miers, indigenous
Lycium gariepense A.M.Venter, indigenous
Lycium grandicalyx Joubert & Venter, indigenous
Lycium hantamense A.M.Venter, indigenous
Lycium hirsutum Dunal, indigenous
Lycium horridum Thunb. indigenous
Lycium mascarenense A.M.Venter & A.J.Scott, indigenous
Lycium oxycarpum Dunal, endemic
Lycium pilifolium C.H.Wright, indigenous
Lycium prunus-spinosa Dunal, accepted as Lycium cinereum Thunb. present
Lycium pumilum Dammer, indigenous
Lycium schizocalyx C.H.Wright, indigenous
Lycium shawii Roem. & Schult. indigenous
Lycium strandveldense A.M.Venter, indigenous
Lycium tenue Willd. endemic
Lycium tetrandrum Thunb. indigenous
Lycium villosum Schinz, indigenous
Nicandra
Genus Nicandra:
Nicandra physalodes (L.) Gaertn. not indigenous, naturalised, invasive
Nicotiana
Genus Nicotiana:
Nicotiana glauca Graham, not indigenous, naturalised, invasive
Nicotiana longiflora Cav. not indigenous, naturalised
Nicotiana tabacum L. not indigenous, naturalised
Nierembergia
Genus Nierembergia:
Nierembergia hippomanica Miers var. glabriuscula Dunal, accepted as Nierembergia hippomanica Miers var. violacea Millan, cultivated
Nierembergia hippomanica Miers var. violacea Millan, not indigenous, naturalised
Nierembergia linariifolia Graham var. glabriuscula (Dunal) Cocucci & Hunz. accepted as Nierembergia hippomanica Miers var. violacea Millan, not indigenous, naturalised
Physalis
Genus Physalis:
Physalis angulata L. not indigenous, naturalised, invasive
Physalis minima L. not indigenous, naturalised
Physalis peruviana L. not indigenous, cultivated, naturalised, invasive
Physalis philadelphica Lam. not indigenous, naturalised
Physalis viscosa L. not indigenous, naturalised, invasive
Salpichroa
Genus Salpichroa:
Salpichroa origanifolia (Lam.) Baill. not indigenous, cultivated, naturalised
Solanum
Genus Solanum:
Solanum acanthoideum Drege ex Dunal, accepted as Solanum dasyphyllum Schumach. & Thonn. indigenous
Solanum aculeastrum Dunal, indigenous
Solanum aculeatissimum Jacq. not indigenous, naturalised
Solanum africanum Mill. endemic
Solanum aggerum Dunal, accepted as Solanum africanum Mill. indigenous
Solanum aggregatum Jacq. accepted as Solanum guineense L. indigenous
Solanum aggregatum Jacq. var. bachmannii (Dammer) Bitter, accepted as Solanum guineense L. indigenous
Solanum albotomentosum C.H.Wright, accepted as Solanum catombelense Peyr.
Solanum americanum Mill. not indigenous, naturalised, invasive
Solanum anguivi Lam. indigenous
Solanum aranoideum Dammer, accepted as Solanum supinum Dunal
Solanum auriculatum Aiton, accepted as Solanum mauritianum Scop.
Solanum bachmannii Dammer, accepted as Solanum guineense L. indigenous
Solanum bansoense Dammer subsp. sanaganum Bitter, accepted as Solanum terminale Forssk.
Solanum betaceum Cav. not indigenous, naturalised, invasive
Solanum bifurcatum Hochst. ex A.Rich. accepted as Solanum terminale Forssk.
Solanum bifurcum Hochst. ex Dunal, accepted as Solanum terminale Forssk.
Solanum bojeri Dunal, accepted as Solanum campylacanthum Hochst. ex A.Rich.
Solanum bracteatum Thunb. accepted as Solanum africanum Mill. indigenous
Solanum burbankii Bitter, accepted as Solanum retroflexum Dunal, indigenous
Solanum burchellii Dunal, indigenous
Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum campylacanthum Hochst. ex A.Rich. subsp. panduriforme (Drege ex Dunal) J.Samuels, accepted as Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum capense L. indigenous
Solanum capense L. subsp. quercilobum Bitter, accepted as Solanum capense L.
Solanum capense L. var. evectistellatum Bitter, accepted as Solanum capense L. indigenous
Solanum capense L. var. sodomaeodes (Kuntze) Bitter, accepted as Solanum sodomaeodes Kuntze, indigenous
Solanum capense L. var. tomentosum C.H.Wright, accepted as Solanum capense L. indigenous
Solanum capense L. var. uniradiatum Bitter, accepted as Solanum sodomaeodes Kuntze, indigenous
Solanum capense L. var. wilmsii (Dammer) Bitter, accepted as Solanum sodomaeodes Kuntze, indigenous
Solanum capsicoides All. not indigenous, naturalised
Solanum catombelense Peyr. indigenous
Solanum chenopodioides Lam. not indigenous, naturalised, invasive
Solanum chondropetalum Dammer, accepted as Solanum tettense Klotzsch
Solanum chrysotrichum Schltdl. not indigenous, naturalised, invasive
Solanum ciliatum Lam. accepted as Solanum capsicoides All. not indigenous
Solanum coccineum Jacq. accepted as Solanum tomentosum L. indigenous
Solanum crassifolium Lam. accepted as Solanum africanum Mill. indigenous
Solanum damarense Bitter, accepted as Solanum humile Lam.
Solanum dasyphyllum Schumach. & Thonn. indigenous
Solanum dasyphyllum Schumach. & Thonn. var. natalense Bitter, accepted as Solanum dasyphyllum Schumach. & Thonn. indigenous
Solanum dasypodum St.-Lag. accepted as Solanum guineense L. indigenous
Solanum dasypus Drege ex Dunal, accepted as Solanum guineense L. indigenous
Solanum dasypus E.Mey. accepted as Solanum guineense L. indigenous
Solanum delagoense Dunal, accepted as Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum delagoense Dunal subsp. transvaalense Bitter, accepted as Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum denudatum Bitter, accepted as Solanum humile Lam.
Solanum didymanthum Dunal, accepted as Solanum rubetorum Dunal, indigenous
Solanum didymanthum Dunal var. plurifolium Dunal, accepted as Solanum rubetorum Dunal, indigenous
Solanum didymanthum Dunal var. spinosa C.H.Wright, accepted as Solanum rubetorum Dunal, indigenous
Solanum dinteri Bitter, accepted as Solanum capense L.
Solanum diplocincinnum Dammer, accepted as Solanum tettense Klotzsch
Solanum dregei Dunal, accepted as Solanum capense L.
Solanum duplosinuatum Klotzsch, accepted as Solanum dasyphyllum Schumach. & Thonn.
Solanum elaeagnifolium Cav. not indigenous, naturalised, invasive
Solanum exasperatum Drege ex Dunal, accepted as Solanum africanum Mill. indigenous
Solanum galpinii Bitter, accepted as Solanum rubetorum Dunal, indigenous
Solanum geniculatum Drege ex Dunal, accepted as Solanum africanum Mill. indigenous
Solanum giftbergense Dunal, accepted as Solanum humile Lam. indigenous
Solanum giganteum Jacq. indigenous
Solanum goetzei Dammer, indigenous
Solanum gracile Dunal, accepted as Solanum chenopodioides Lam. not indigenous
Solanum guineense L. endemic
Solanum heterandrum Pursh, accepted as Solanum rostratum Dunal
Solanum humile Lam. indigenous
Solanum incanum L. subsp. horridescens Bitter, accepted as Solanum lichtensteinii Willd. indigenous
Solanum incanum L. var. lichtensteinii Bitter, accepted as Solanum lichtensteinii Willd. indigenous
Solanum incanum L. var. subexarmatum (Dunal) Bitter, accepted as Solanum lichtensteinii Willd. indigenous
Solanum inconstans C.H.Wright, accepted as Solanum terminale Forssk.
Solanum indicum L. var. suprastrigulosum Bitter, accepted as Solanum anguivi Lam. indigenous
Solanum jasminoides Paxton, accepted as Solanum laxum Spreng. not indigenous, naturalised
Solanum kibweziense Dammer, accepted as Solanum tettense Klotzsch
Solanum koniortodes Dammer, accepted as Solanum tettense Klotzsch
Solanum kwebense N.E.Br. ex C.H.Wright, accepted as Solanum tettense Klotzsch, indigenous
Solanum kwebense N.E.Br. ex C.H.Wright var. acutius Bitter, accepted as Solanum tettense Klotzsch
Solanum kwebense N.E.Br. ex C.H.Wright var. chondropetalum (Dammer) Bitter, accepted as Solanum tettense Klotzsch
Solanum kwebense N.E.Br. ex C.H.Wright var. luederitzii (Schinz) Bitter, accepted as Solanum tettense Klotzsch
Solanum kwebense N.E.Br. ex C.H.Wright var. majorifrons Bitter, accepted as Solanum tettense Klotzsch
Solanum laciniatum Aiton, not indigenous, cultivated, naturalised, invasive
Solanum laxum Spreng. not indigenous, naturalised
Solanum leucophaeum Dunal, accepted as Solanum supinum Dunal, indigenous
Solanum lichtensteinii Willd. indigenous
Solanum linnaeanum Hepper & P.-M.L.Jaeger, indigenous
Solanum litoraneum A.E.Gonç. indigenous
Solanum longipes Dunal, accepted as Solanum africanum Mill. indigenous
Solanum luederitzii Schinz, accepted as Solanum tettense Klotzsch
Solanum lycopersicum L. not indigenous, cultivated, naturalised, invasive
Solanum lycopersicum L. var. cerasiforme (Alef.) Voss, accepted as Solanum lycopersicum L. not indigenous, cultivated, naturalised, invasive
Solanum lyratifolium Dammer, accepted as Solanum supinum Dunal
Solanum macowanii Fourc. accepted as Solanum capsicoides All. not indigenous
Solanum macrocarpon L. not indigenous, cultivated
Solanum mauritianum Scop. not indigenous, naturalised, invasive
Solanum merkeri Dammer, accepted as Solanum campylacanthum Hochst. ex A.Rich.
Solanum miniatum Bernh. ex Willd. accepted as Solanum villosum Mill. subsp. miniatum (Bernh. ex Willd.) Edmonds, not indigenous
Solanum moestum Dunal, accepted as Solanum rubetorum Dunal, indigenous
Solanum molle Burm.f. accepted as Solanum tomentosum L. indigenous
Solanum monotanthum Dammer, accepted as Solanum zanzibarense Vatke
Solanum monticolum Dunal, accepted as Solanum guineense L. indigenous
Solanum multiglandulosum Bitter, accepted as Solanum humile Lam.
Solanum multiglandulosum Bitter var. multiarmatum Bitter, accepted as Solanum humile Lam.
Solanum namaquense Dammer, accepted as Solanum capense L. indigenous
Solanum nigrum L. not indigenous, naturalised
Solanum niveum Vahl, accepted as Solanum giganteum Jacq. indigenous
Solanum nodiflorum Jacq. accepted as Solanum americanum Mill. not indigenous
Solanum omahekense Dammer, accepted as Solanum campylacanthum Hochst. ex A.Rich.
Solanum omitiomirense Dammer, accepted as Solanum campylacanthum Hochst. ex A.Rich.
Solanum panduriforme Drege ex Dunal, accepted as Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum pentheri Gand. accepted as Solanum campylacanthum Hochst. ex A.Rich. indigenous
Solanum plousianthemum C.H.Wright var. rhodesianum (Dammer) Bitter, accepted as Solanum terminale Forssk.
Solanum plousianthemum Dammer, accepted as Solanum terminale Forssk.
Solanum pseudocapsicum L. not indigenous, naturalised, invasive
Solanum pulverulentum L. accepted as Solanum tomentosum L.
Solanum quadrangulare Thunb. ex L.f. accepted as Solanum africanum Mill. indigenous
Solanum quadrangulare Thunb. ex L.f. var. crassifolium (Lam.) Bitter, accepted as Solanum africanum Mill. indigenous
Solanum quadrangulare Thunb. ex L.f. var. glabrum Dammer, accepted as Solanum africanum Mill. indigenous
Solanum quadrangulare Thunb. ex L.f. var. integrifolium Dunal, accepted as Solanum africanum Mill. indigenous
Solanum quadrangulare Thunb. ex L.f. var. sinuato-angulatum Dunal, accepted as Solanum africanum Mill. indigenous
Solanum rangei Dammer, accepted as Solanum burchellii Dunal
Solanum rautanenii Schinz, accepted as Solanum catombelense Peyr.
Solanum renschii Vatke, accepted as Solanum tettense Klotzsch, indigenous
Solanum retroflexum Dunal, indigenous
Solanum rhodesianum Dammer, accepted as Solanum terminale Forssk.
Solanum rigescens Jacq. accepted as Solanum humile Lam. indigenous
Solanum rigescens Jacq. var. didymanthum (Dunal) Bitter, accepted as Solanum rubetorum Dunal, indigenous
Solanum rigescens Jacq. var. horridus Bitter, accepted as Solanum rubetorum Dunal, indigenous
Solanum rigescens Jacq. var. nanum Dunal, accepted as Solanum rubetorum Dunal, indigenous
Solanum rigescens Jacq. var. parvibaccatum Bitter, accepted as Solanum humile Lam. indigenous
Solanum rigescens Jacq. var. rubetorum (Dunal) Bitter, accepted as Solanum rubetorum Dunal, indigenous
Solanum rigescentoides Hutch. accepted as Solanum humile Lam.
Solanum rogersii S.Moore, accepted as Solanum sisymbriifolium Lam. not indigenous
Solanum rostratum Dunal, not indigenous, naturalised
Solanum rubetorum Dunal, endemic
Solanum sarrachoides Sendtn. not indigenous, naturalised
Solanum schaeferi Dammer, accepted as Solanum burchellii Dunal
Solanum seaforthianum Andrews, not indigenous, naturalised, invasive
Solanum seaforthianum Andrews var. disjunctum O.E.Schulz, accepted as Solanum seaforthianum Andrews, not indigenous, naturalised
Solanum sempervirens Mill. accepted as Solanum guineense L. indigenous
Solanum sisymbriifolium Lam. not indigenous, naturalised, invasive
Solanum sodomaeodes Kuntze, indigenous
Solanum sparsiflorum Dammer, accepted as Solanum catombelense Peyr.
Solanum subexarmatum Dunal, accepted as Solanum lichtensteinii Willd. indigenous
Solanum subrectemunitum Bitter, accepted as Solanum humile Lam.
Solanum supinum Dunal, indigenous
Solanum supinum Dunal var. aranoideum (Dammer) Bitter, accepted as Solanum supinum Dunal
Solanum supinum Dunal var. leucophaeum (Dunal) Bitter, accepted as Solanum supinum Dunal, endemic
Solanum supinum Dunal var. lyratifolium (Dammer) Bitter, accepted as Solanum supinum Dunal
Solanum supinum Dunal var. rehobothense Bitter, accepted as Solanum supinum Dunal
Solanum tenuiramosum Dammer, accepted as Solanum tettense Klotzsch
Solanum terminale Forssk. indigenous
Solanum terminale Forssk. subsp. inconstans (C.H.Wright) Heine, accepted as Solanum terminale Forssk.
Solanum terminale Forssk. subsp. sanaganum (Bitter) Heine, accepted as Solanum terminale Forssk.
Solanum tettense Klotzsch, indigenous
Solanum tettense Klotzsch var. renschii (Vatke) A.E.Gonç. accepted as Solanum tettense Klotzsch, indigenous
Solanum tomentosum L. indigenous
Solanum tomentosum L. subsp. pauciaculeolatum Bitter, accepted as Solanum rubetorum Dunal, indigenous
Solanum tomentosum L. var. brevifrons Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. burchellii (Dunal) Wright, accepted as Solanum burchellii Dunal, indigenous
Solanum tomentosum L. var. coccineum (Jacq.) Willd. accepted as Solanum tomentosum L. endemic
Solanum tomentosum L. var. integrifolium Flanagan & Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. longiarmatum Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. megalocarpum Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. mollissimum Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. scabriusculum Bitter, accepted as Solanum tomentosum L. indigenous
Solanum tomentosum L. var. sublyratum Bitter, accepted as Solanum tomentosum L. indigenous
Solanum torreanum A.E.Gonç. indigenous
Solanum torvum Sw. not indigenous, naturalised
Solanum triflorum Nutt. not indigenous, naturalised, invasive
Solanum tuberosum L. not indigenous, naturalised
Solanum umtuma Voronts. & S.Knapp, endemic
Solanum upingtoniae Schinz, accepted as Solanum tettense Klotzsch
Solanum urosepalum Dammer, accepted as Solanum rubetorum Dunal, indigenous
Solanum usaramense Dammer, indigenous
Solanum vagans C.H.Wright, accepted as Solanum zanzibarense Vatke, indigenous
Solanum viarum Dunal, not indigenous, naturalised
Solanum villosum Mill. not indigenous, naturalised
Solanum villosum Mill. subsp. miniatum (Bernh. ex Willd.) Edmonds, not indigenous, naturalised
Solanum villosum Mill. subsp. villosum, not indigenous, naturalised
Solanum wilmsii Dammer, accepted as Solanum sodomaeodes Kuntze, indigenous
Solanum zanzibarense Vatke, indigenous
Solanum zanzibarense Vatke var. vagans (C.H.Wright) Bitter, accepted as Solanum zanzibarense Vatke, indigenous
Withania
Genus Withania:
Withania somnifera (L.) Dunal, indigenous
Sphenocleaceae
Family: Sphenocleaceae,
Sphenoclea
Genus Sphenoclea:
Sphenoclea zeylanica Gaertn. indigenous
References
Biodiversity of South Africa
Solanales | List of Solanales of South Africa | [
"Biology"
] | 9,045 | [
"Biodiversity",
"Biodiversity of South Africa"
] |
65,813,948 | https://en.wikipedia.org/wiki/Societal%20effects%20of%20negligible%20senescence | The societal effects of negligible senescence considers a scenario where negligible senescence is achieved on a societal wide level in humans. There is much controversy about the realistic timeline of such a scenario. The predictions vary in time starting from 2037 till later than the 21st century. The effects of negligible senescence has a profound impact on economy, climate, demographics and impacts social structures. The baseline scenario ceteris paribus of negligible senescence is more population growth while a larger healthier labor force would spur economic growth.
Definition and characteristics
Senescence is defined as the gradual deterioration of functional characteristics. The word senescence can either refer to cellular senescence or to senescence of a whole organism. Negligible senescence is therefore defined as the lack of senescence or a very small amount of senescence. Which implies that mortality and morbidity from most causes is eliminated. The term was introduced by biogerentologist Caleb Finch to denote organisms that do not exhibit evidence of biological aging and was further popularized by gerontologist Aubrey de Grey.
Proximity of a negligible senescence society
The timeline wherein humanity will achieve a negligible senescence scenario is unclear. For instance, in the Worldbank projections of demographics until 2050 death rate per 1,000 is increasing year-on-year thus implying no projection of negligible senescence before 2050. Although visionaries like Yuval Noah Harari do mention the possibility of a negligible senescence society Noah also remarks that he seems this is not likely to happen in the 21st century. Only a few people have publicly announced that they deem negligible senescence likely in the 21st century, such as Aubrey de Grey, founder of the SENS Research Foundation.
Societal impact
Demographics
The impact of negligible senescence on worldwide demographics is widely accepted;. Coale noted that a shift toward near-immortality would have the same long-term impact on population growth as a 10% increase in the fertility rate. As the death rate per thousand people will drop from roughly 10 per thousand (1% per year) to near zero this would thus add an extra 1% population growth each year.
Although aging populations in population pyramids result in "constructive" pyramids which are narrowed at the bottom, this might not necessarily be the case in the aging population in a negligible senescence scenario. Depending on the total fertility rate (TFR) all three different shapes of population pyramids can be observed.
Many questions still remain regarding demographic predictions in negligible senescence scenario's. The TFR has steadily decreased from 5 in 1950–1955 to around 2.5 in 2010–2015. The impact of negligible senescence on future TFR is unclear as there might be a reduced sense of self"replacement". However, this might be offset by no biological limitations on having an unlimited number of children (delay or complete eradication of menopause) which in turn may or may not occur with negligible senescence. Furthermore, the age of mothers might increase or stay stable depending on a myriad of factors thus impacting TFR.
Economics
The impact of negligible senescence on the economy is multi-faceted. Many developed countries face population ageing due to demographic transition whereas in the least developed countries people of old age only resembles a small part of the total population. Therefore, the development of negligible senescence therapies have profoundly different effects on the economies of countries with different demographic characteristics.
From a worldwide perspective eliminating senescence has a massive effect on the economy. As current productivity losses for employers in the US alone is calculated at 225.8 billion annually the impact can be large. Furthermore, changes in pension plans might enable unlimited perpetual productivity after childhood ceteris paribus and thus eliminating the 'Aged dependency ratio' in the equation of dependency ratios. These effects are partly offset with the costs of providing negligible senescence therapies.
Life in a negligible senescence society
As philosopher Nick Bostrom mentioned in his story "The Fable of the Dragon-Tyrant" referring to the end of senescence: "And in the coming days... I believe we have some reorganization to do!". Humankind has experienced senescence for all its history. Therefore, major challenges are necessarily to fill the void the lack of senescence has now left behind. However, he does not substantiate this any further into practical measures.
See also
Timeline of senescence research
Aging brain
Pro-aging trance
References
Senescence
Biological evolution
Immortality | Societal effects of negligible senescence | [
"Chemistry",
"Biology"
] | 930 | [
"Senescence",
"Metabolism",
"Cellular processes"
] |
65,814,387 | https://en.wikipedia.org/wiki/NGC%202188 | NGC 2188 is a barred spiral galaxy in the constellation Columba. It is located at a distance of circa 25 million light years from Earth, which means that the galaxy, given its apparent dimensions is about 50.000 light years long. It was discovered by John Herschel on January 9, 1836.
NGC 2188 is a spiral galaxy seen edge-on from the viewpoint of Earth as the centre and spiral arms of the galaxy are tilted away from us, with only the very narrow outer edge of the galaxy's disc visible to us. The true shape of the galaxy was identified by studying the distribution of the stars in the inner central bulge and outer disc and by observing the stars' colours. The galaxy is close enough that its stars can be resolved. The brightest of them have an apparent magnitude of about 21.
When imaged in HI, the galaxy appears asymmetrical, maybe due to a recent interaction. The hydrogen gas is more abundant in one end of the galaxy and extends over 4 kpc away from the galactic plane. Other features visible are some filaments and a superbubble with a diameter of 15 arcseconds. The filaments have been associated with a HII region located in the galactic halo. The total hydrogen mass of the galaxy is estimated to be , while it is of low metallicity.
NGC 2188 has been found to have three smaller companions, HIPASS J0607-34, ESO364-029, and KK 55.
References
External links
Barred spiral galaxies
Dwarf spiral galaxies
Columba (constellation)
2188
18536
Magellanic spiral galaxies | NGC 2188 | [
"Astronomy"
] | 331 | [
"Columba (constellation)",
"Constellations"
] |
62,014,670 | https://en.wikipedia.org/wiki/Virtual%20Viking%20%E2%80%93%20The%20Ambush | Virtual Viking – The Ambush is a 2019 short film directed by Erik Gustavson, using volumetric video capture to create one of the first films in virtual reality. Produced for The Viking Planet centre in Oslo, Norway, the film is part of a wider exhibition of the lives of Norse seafarers and uses a number of VR headsets to enable visitors to experience a Viking longship in the heat of battle.
Plot
Skald recounts the story of how he was captured, in his youth, during an unsuccessful Viking raid.
Cast
Murray McArthur as Skald
Luke White as Ulf
Wolfie Hughes as Grim
Christopher Rogers as Trym
Ross O'Hennessy as Viking
Awards and nominations
At the Aesthetica Short Film Festival 2019, Virtual Viking – The Ambush was awarded Best VR Film.
References
External links
2019 films
Norwegian short films
Old Norse-language films
Head-mounted displays
Video game accessories
Virtual reality | Virtual Viking – The Ambush | [
"Technology"
] | 181 | [
"Video game accessories",
"Components"
] |
62,015,338 | https://en.wikipedia.org/wiki/Strasbourg%20Institute%20of%20Material%20Physics%20and%20Chemistry | The Strasbourg Institute of Material Physics and Chemistry (IPCMS—) is a joint research unit (UMR 7504) between the French National Center for Scientific Research (CNRS) and the University of Strasbourg. It was founded in 1987 and is located in the district of Cronenbourg in Strasbourg, France.
History
The IPCMS was born from a reflection initiated in the early eighties on the need to refocus and coordinate research in the physics and chemistry of condensed matter and materials. In the context of the then emerging Materials Center in Strasbourg, a first reorganization project for condensed matter physics was formalized in 1983. Then, in the same years, the strategic importance of materials for innovation is recognized, justifying the extension of the initial project to chemists, to constitute the backbone of the future institute by bringing together physicists and chemists on the objective of designing and studying new materials (metals, ceramics, ...) for their electronic properties (magnetic, optical, dielectric, etc.). CNRS-ULP-EHICS joint unit, the IPCMS is officially created in 1987 with François Gautier as Director and Jean-Claude Bernier as deputy director. Originally located on five different sites of the University of Strasbourg, it was in 1994 that members of the IPCMS were grouped together in the current building on the Campus of Cronenbourg. The IPCMS is then organized into five research groups around three types of materials - polymers and organic materials, metallic materials, ceramics and inorganic materials - and two topics of study: nonlinear optics and optoelectronics on one hand, surfaces and interfaces on the other hand.
Research
The multi-disciplinary nature of the IPCMS is expressed by leading activities in spin electronics, magnetism, ultra-fast optics, electron microscopy and local probes, biomaterials as well as in the synthesis and characterization of functional organic, inorganic or hybrid materials. All scales are considered from the isolated molecule to organized nanostructures on surfaces and single or two-dimensional objects, up to nano-devices. To carry out these studies, the institute has an important instrumental park for the fabrication and characterization of materials at all scales. The developments are also based on recognized theoretical skills. The projects LabEX NIE and EquipEX UNION and UTEM that the IPCMS directs reflect the recognized position of the laboratory. Located on the Campus of Cronenbourg, IPCMS is affiliated with the institutes of physics and chemistry of the CNRS as well as the Faculty of Physics and Engineering, it is also affiliated with the European School of Chemistry, Polymers and Materials (ECPM), Télécom Physique Strasbourg, and the Faculty of Chemistry of the University of Strasbourg. The IPCMS is very attached to maintain strong links with the industrial laboratories carrying out research in its fields of competence.
Departments
The IPCMS now employs a staff of 240 including about 80 researchers and teacher-researchers and 60 technical and administrative engineers, whose activities are divided into five departments:
Department of Inorganic Materials Chemistry (DCMI)
Department of Organic Materials (DMO)
Department of Magnetism of NanoStructured Objects (DMONS)
Department of Ultrafast Optics and Nanophotonics (DON)
Department Surfaces and Interfaces (DSI)
Awards
In 2008 Jean-Yves Bigot receives the CNRS silver medal, in 2009 he is also the recipient of an Advanced Grant ATOMAG from the European Research Council (ERC), and in February 2016 he received the Jean Ricard Award from the Société Française de Physique (SFP).
In 2013 Guillaume Schull is a laureate of the ERC Consolidated APOGEE.
July 2019, Ovidiu Ersen is the winner of the Grand Prize Raimond Castaing of the Société Francaise des Microscopies.
See also
Institut Charles Sadron
Hubert Curien Multi-disciplinary Institute
Notes
References
External links
Department pages:
DCMI website
DMO website
DMONS website
DON website
DSI website
Physics research institutes
Chemistry organizations
Nanomaterials
Research institutes in France
University of Strasbourg
1987 establishments in France
Educational institutions established in 1987
Buildings and structures in Strasbourg
French UMR | Strasbourg Institute of Material Physics and Chemistry | [
"Chemistry",
"Materials_science"
] | 851 | [
"Nanotechnology",
"Nanomaterials",
"nan"
] |
62,016,002 | https://en.wikipedia.org/wiki/SS584 | SS 584 (also known as Multi-Tier Cloud Security (MTCS)) is an information security standard, published by Singapore Standards. The standard was last revised in 2020.
SS 584 specifies a Management system for Cloud Security, to three levels. Organizations that meet the requirements may be certified by an accredited certification body following successful completion of an audit.
Rationale
Although most Cloud Service Providers are certified to ISO 27000, the ISO standard does not focus on the unique risks arising from provisioning via the Cloud. Smaller customers also have difficulty assessing if a CSP's ISMS is sufficient for their needs, as ISO 27001 is risk-based, and may vary significantly between implementations. This may be a barrier to adoption by SMEs, who would like a simpler way to decide if a CSP meets their needs.
To encourage adoption of Cloud Services, the then IDA established a series of groups in 2012 to produce a standard that CSPs could certify to. The standard would have multiple levels of security assurance:
Tier 1: Designed for non-business critical data and system, with baseline security controls to address security risks and threats in potentially low impact information systems using cloud services (e.g.: Web site hosting public information)
Tier 2: Designed to address the need of most organizations running business critical data and systems through a set of more stringent security controls to address security risks and threats in potentially moderate impact information systems using cloud services to protect business and personal information (e.g.: Confidential business data, email, CRM – customer relation management systems)
Tier 3: Designed for regulated organizations with specific requirements and more stringent security requirements. Industry specific regulations may be applied in addition to these controls to supplement and address security risks and threats in high impact information systems using cloud services (e.g.: Highly confidential business data, financial records, medical records)
Note that the standard interchangeably uses the terms "tiers" and "levels".
History of SS 584
SS584:2013 was issued in 2013, and the program was initially administered by IDA.
In 2015, the standard was revised (SS 584:2015). At this time, Accreditation was handed over to the Singapore Accreditation Council, a division of Enterprise Singapore, in line with other Singapore Standards.
As of late 2019, the standard is being revised again, with inputs from industry, and a new version will be issued in Oct 2020.
Certification
CSPs that wish to have their services certified must classify each into IaaS, PaaS, or SaaS. They also decide to which level they wish to demonstrate compliance (Tier 1, 2, or 3).
For compliance to Level 3, the CSP must be certified to ISO/IEC 27001.
CSPs must obtain the services of an Accredited Certification Body, who will audit the management system of the CSP for compliance to SS 584. The CB will then issue a Certificate attesting to this, usually valid for three years. Annual Surveillance Audits are required.
A list of Services and CSPs certified is available. Examples of Certified CSPs include IBM and AWS.
Overseas Acceptance
Although the standard is not an International standard, as the first national standard to address Cloud Security, it has seen acceptance outside Singapore. In particular, the Korean RSEFT regulations recognise SS 584 as meeting most of the requirements for CSPs.
Documents from Datamation and CloudwatchHUB describe the international use and impact of this standard.
See also
Cyber security standards
ISO/IEC 27001
Singapore Standard (regulatory policy)
References
Information assurance standards | SS584 | [
"Technology"
] | 722 | [
"Computer standards",
"Information assurance standards"
] |
62,016,308 | https://en.wikipedia.org/wiki/UVA%20method | The UVA method (fr. Méthode des Unités de Valeur Ajoutée - the Value-added Unit Method) is an accounting and decision-making tool, based on calculating the cost of sales. Unlike management accounting, which calculates product margins, the UVA method calculates the result (profit or loss) generated by each sale. The UVA method relies on a very detailed analysis of all costs related to products, customers, orders, and deliveries. It introduces the notion of a single measure unit (the UVA), which applies to all the operations in the company. The method relies on an equivalent-based approach.
Origins of the UVA Method
The UVA method is an upgrade of the GP method., which traces back to the works of Georges Perrin (1891–1958), a French engineer and a graduate of the Ecole Centrale. In 1953, he presented his product costing method, based on the introduction of a measure unit – the GP –, which was distinct from currency, and which allowed one to express the entire production of a company. The GP unit stands for the effort that the company needs to make in order to produce a representative good (a basic item). The validity of the method relies on the principle of the occult constants, postulated by Georges Perrin, according to which the relationships between the production efforts made to produce various goods remain stable over time.
Jean Fiévez and Robert Zaya from the Les Ingénieurs Associés (LIA) consulting office, took it to the next level. In 1995, its name changed into the Value-added Unit Method (UVA). As against the GP method, which focused only on product costing, the UVA method looks into most about every operation in the company.
Basic Concepts of the UVA Method
The UVA method relies on a highly detailed analysis of all value-producing processes, which involves both product-related processes and customer-related ones.
The whole added-value production of a business is measured with the help of one unit: the UVA. The idea of using a measure unit that would be shared by all the company's operations is based on the fact that only companies that make a single product know its cost perfectly (namely, the result of total expenses divided by the number of units produced). The introduction of the UVA changes every company into a “mono-product” one
By analysing all of its processes, the company can envisage “determining its results per sale”. This is the main objective of the UVA method, since a transaction/sale (which translates into an invoice) concentrates all the efforts carried out through the company's various operations. This is clearly a new approach to management, in which one asks oneself whether a transaction between the company and its customer results in profit or loss. The customer is therefore at the centre of the decision-making mechanism. When the customer buys something for a given sum, has the company earned or lost money? Each sale contributes to the overall result of the company. The result of a sale is the difference between the cashed amount and the cost of the sale. The aggregated results of all sales constitute the company's EBIT (earnings before interest and taxes).
The question of precision in costing is linked to the presence of indirect costs. By placing the sale at the centre of the analysis, the UVA method does away with direct/indirect costs, because from a sale viewpoint, all costs are direct: sold products, transport, order processing, invoicing, etc. Thanks to that approach, the UVA method provides a high result precision.
The method presents two cost axes: product costs and customer costs. Product costs include design, processing, raw materials, production, control, storage, post-sale service, etc. Everything that the company has had to do to sell its products (or services) falls under the customer costs. Customer costs include market research, order processing, order preparation, shipment, invoicing, etc.
About 90 to 95 percent of resources fall under two categories of costs: products and customers. The rest of the costs have to do with the internal operation of the business: general management, financial accounting, etc.
Product costs have two distinct components: the cost of the value added by the company and the cost of integrated purchases. Integrated purchases (essentially, the raw materials required to produce a good) are called Product-specific Expenses (PSE), according to the UVA method. They can be found in the nomenclatures, so they are easy to calculate.
Customer costs, too, have two distinct components: the cost of the added value and the Customer-specific Expenses (CSE). The CSE may include the commission to the representative, the customer rebate, or the price paid to the carrier. These are costs that are determined directly.
The UVA method focuses on a precise calculation of the added value.
All the added value that the business produces is measured by a single unit: the UVA.
Main Notions
The UVA method introduces a certain number of specific notions :
Attributable expenses
They are expenses that can be attributed to the entries without any key of arbitrary allocation; they represent the use of resources by the entries.
The main attributable expenses are the following:
Direct and indirect labour. This includes salaries, social contributions, cost of personnel service, and fringe benefits (accommodation, car, transportation tickets, etc.).
Consumables. In an office, they generally include the telephone, the IT equipment, the office supplies, etc., and in a workshop: the electric power, the compressed air, the lubricants, etc.
Maintenance (spare parts and labour);
Depreciation – calculated on the basis of the replacement value of the equipment, its expected lifespan, and the annual number of operating hours;
Area-related expenses include building depreciation or rent, maintenance and cleaning, heating, light, insurance, and others.
Cost of a Sale
The cost of a sale is the sum of product costs and customer costs incurred by the company in order to carry out the sale.
Index of a UVA Entry
The index of a UVA entry is the ratio between its rate and the basic rate.
In other words, the index of a UVA entry is given by its use of resources, expressed in added value units.
Process
The process (or sequence of operations) is a succession of activities that are carried out in association with a UVA entry, within a given timeframe. The concept of UVA entry allows one to define every process that they identify in a business – without making a distinction between the manufacturing processes and any other process that generate added value (management, marketing, etc.), but rather viewing them as a sequence of operations carried out at the UVA entries during a given timeframe.
Profitability Curve
The profitability curve of the sales is a curve that represents the aggregated turnover (invoice by invoice) on its abscissa and the result rate (the result as a percentage of the turnover) on its ordinate. The invoices are classified in ascending order of the result rate.
The profitability curve shows a summarised structure of the result that the company has obtained during a given time period. It emphasises the heterogeneity of the transaction results obtained by the business. The company's global result may be positive, but the results of the sales that make it up will be highly-variable. One distinguishes four categories of sales: highly-deficient sales – the so-called “hemorrhagic” ones (which have a result rate below –20 percent), deficient sales (going from –20 to 0 percent), profitable sales (0 to 20 percent), and the so-called dangerously profitable sales (of over 20 percent). The graph displays a sales profit curve in its canonical form. Turnover percentages may vary a lot from one category to another; on the other hand, result variation is common in all companies. In addition to the base curve that groups all sales together, one may plot out curves to represent a higher level of data aggregation. A sale that is represented by an invoice is in fact a “foundation brick” that enables one to form various types of groups. For instance, by grouping together all the invoices per customer, one obtains a customer profitability curve.
Profit curve in canonical form
Rate of UVA Entry
The rate of a UVA entry is the sum of the resources that have been used per unit of work. It includes labour, depreciation, floor space used, consumables, maintenance, etc. To calculate it, one must add up the unit expenses attributable to the entry.
Result of a sale
The result of a sale is the difference between the amount paid and the cost of the sale.
UVA – Added Value Unit
The added value unit (1 UVA) represents the use of resources required to carry out a typical process within the company's activity: generally speaking, it is the manufacturing of an item (in the case of a processing company) and execution of a service (in the case of a service company). The process is called basic process, and its rate will be the basic rate. By definition, the added-value unit corresponds to the amount of resources that have been used and which are required to carry out the basic process (producing a good or performing a service).
To calculate the current monetary cost of the unit, it is enough to divide the expenses that were incurred during a specific period of time by the number of UVAs produced during that period (UVAP). The product-specific expenses and customer-specific expenses (PSE and CSE) are deducted from the cost amount (C) provided by the general accounting, because these expenses are taken into account directly.
UVA Equivalent of a Process
The UVA equivalent of a process is given by its use of resources, expressed in added value units.
By multiplying the index of every UVA entry involved in a process execution by the usage time thereof, one obtains its use of resources (expressed in UVA) during that process. The sum of these uses constitutes the UVA equivalent of the process.
UVA Entry
The UVA entry comprises all the material and human resources needed to carry out an operation, which are used in a clearly-defined technical and economic framework. In other words, a UVA entry is by definition a homogeneous package of resource uses. UVA entries are present in every company operation.
To do a precise analysis of a company's operations, one needs to start by reviewing all of its work entries. The number of UVA entries depends on the size and structure of the analysed company and may range from a few dozen to several hundred.
Implementation of the UVA Method
The implementation of the UVA method is composed of two phases : construction and exploitation
Construction
The construction of the UVA method comprises the following steps:
inventory of UVA entries
analysis of attributable expenses
calculating the rate of the UVA entries
choosing the UVA unit
calculating the indices of the UVA entries
describing the sequence of operations
calculating the UVA equivalents of processes
Exploitation
To exploit the method means:
to measure the added-value production, expressed as UVA
to calculate the UVA cost
to calculate the costs of products, customers, and sales
to calculate the results of each sale
to plot out profitability curves
Fields of application
The UVA method can be applied in industrial, service and distribution enterprises which can be described as a repetitive process network in production, administration, logistic etc. In contrast to companies that work by individual projects.
The best results can be obtained for heterogeneous, complexe entreprises what means commercialising many different products and having many clients.
Advantages and limitations
precision of calculations and detail of results
simplicity and ease of use
time-consuming process of method construction
relatively few documented applications
Innovations of the UVA Method
The UVA method is not a method of cost allocation. In management accounting, one “cuts up” the whole (= the company) into “pieces” (sections/centres of analysis/activities). Then in the same way, all the expenses are discharged/allocated to each portion that was cut out. This approach may be described as “cost allocation” [as done in traditional bookkeeping]. It is a top-down approach. With the UVA method, one does the reverse – a re-composition: at a micro-scale (namely, at the level of one sale), one identifies each and every element that has helped carry out the sale. Then by adding up all the sale transactions, one recomposes almost all the resources of the company. The only resources that are not allocated directly here are those that are associated with the internal management processes; however, they are to be found in the cost of each transaction, via the UVA cost. This is a bottom-up approach.
The UVA method regards the company as a network of processes. The method makes a precise analysis of all these processes. The novelty of the UVA method is to analyse not only the processes related to sold products, but also the ones related to served customers.
According to the UVA method, the object of the costing is the sale, not the product. Thanks to this new way of viewing things, product-related costs that were indirect now become direct, as from the viewpoint of a sale, all costs are direct: the cost of sold products, the freight cost, the cost of order processing and invoicing, etc. The difference between the amount that is invoiced to the customer and the cost of the sale gives the result: profit or loss. The UVA method is the only one that allows one to calculate the profitability of each sale.
The profitability curve is one of the most valuable indicators provided by the UVA method. It has been made possible by choosing to view the sale as a cost object. The curve can be plotted out, since one calculates the profitability of each invoice. Thanks to the profitability curve, the account managers determine the structure of the company's result and can make precisely-targeted decisions.
References
Accounting systems | UVA method | [
"Technology"
] | 2,922 | [
"Information systems",
"Accounting systems"
] |
62,016,838 | https://en.wikipedia.org/wiki/Nanako%20Shigesada | is a Professor Emeritus at Nara Women's University in Japan, most notable for her work in the fields of mathematical biology and theoretical ecology. Her established career in academia has seen many of her journals published to acclaim, as well as contributing to the education of researchers at Kyoto University and Doshisha University. Shigesasda has served as the Research Supervisor for the Basic Research Program PRESTO in the research area "Innovative Models of Biological Processes and its Development", supported by the Japan Science and Technology Agency from 2007-2013. She has also served as Secretary General and President for The Japanese Society for Mathematical Biology. In 2013, she was awarded the Akira Okubo Prize.
Career
In the 1970s Shigesasda was an active member of Mumay Tansky, a group composed of Shigesasda and colleagues Ei Teramoto, Hiroshi Ashida, Hisao Nakajima, Kohkichi Kawasaki, and Norio Yamamura. The group, organised by Teramoto, published papers on structure, stability and efficiency of ecosystems.
In 1979, Shigesada focused on the observational study of the spatial distribution of ant lions by ecologist Masaaki Morisita. She studied the concept of the structures of experience and consciousness (phenomenology) with regards to environmental density and the degree to which a habitat might be unfavourable. She introduced a model that combined population pressure, due to mutual interference between individuals, with environmental potential. Shigesasda extended Morisita's work, explaining how coexistence of competing species can arise through spatial segregation.
In the last twenty years, Shigesada studied pine wilt disease which is caused by the pinewood roundworm with a pine sawyer beetle as vector. Through the study of population dynamics, she estimated beetle densities and parameter values, finding that there is a threshold host density above which the disease can spread, and that the minimum density critically depends on the eradication rate.
Notable works
References
Living people
Year of birth missing (living people)
Academic staff of Kyoto University
Academic staff of Doshisha University
Mathematical and theoretical biology
21st-century Japanese biologists | Nanako Shigesada | [
"Mathematics"
] | 437 | [
"Applied mathematics",
"Mathematical and theoretical biology"
] |
62,017,767 | https://en.wikipedia.org/wiki/Superplan | Superplan was a high-level programming language developed between 1949 and 1951 by Heinz Rutishauser, the name being a reference to "" (i.e. computation plan), in Konrad Zuse's terminology designating a single program.
The language was described in Rutishauser's 1951 publication (i.e. Automatically created Computation Plans for Program-Controlled Computing Machines).
Superplan introduced the keyword as for loop, which had the following form ( being an array item):
Für i=base(increment)limit: + addend =
See also
Compiler
Translator
References
Further reading
(77 pages)
Programming languages created in 1949
Procedural programming languages
Non-English-based programming languages
Swiss inventions
Heinz Rutishauser
Konrad Zuse
1940s establishments in Switzerland | Superplan | [
"Technology"
] | 162 | [
"Non-English-based programming languages",
"Natural language and computing"
] |
62,018,822 | https://en.wikipedia.org/wiki/Betty%20Sullivan | Betty Julia Sullivan (31 May 1902 — 25 December 1999) was an American biochemist between the 1920s and 1940s at Russell Miller Milling Company. In 1947, Sullivan began her executive career as research director and vice-president for Russell Miller until the company became part of Peavey Company in 1958. After the merger, Sullivan remained in her executive roles before leaving in 1967 to co-start an agribusiness consulting company. While working at Experience Inc., Sullivan became director of the company in 1975 and retired in 1992. During her career, Sullivan was the first woman to receive the Osbourne Medal from the American Association of Cereal Chemists, in 1948. In 1954, Sullivan was awarded the Garvan–Olin Medal from the American Chemical Society.
Early life and education
On May 31, 1902, Sullivan was born in Minneapolis, Minnesota. Sullivan attended the University of Minnesota for her Bachelor of Science in 1922. She is of Irish ancestry. In the mid-1920s, Sullivan left the United States and completed a master's degree at the University of Paris in 1925. The following year, she conducted research at the Pasteur Institute in 1926. In 1935, Sullivan returned to the University of Minnesota for a Doctor of Philosophy in biochemistry and a minor degree in organic chemistry. Sullivan wrote her Bachelor of Science thesis on the chemical reactions in pinene and her PhD thesis about the lipids found in wheat.
Career
In 1922, Sullivan started her chemistry career as a lab assistant for the Russell Miller Milling Company in 1922. While at Russell Miller, Sullivan was promoted to head chemist in 1927 and research director in 1947. While researching the food chemistry of wheat and flour, Sullivan simultaneously held the position of vice-president. After Russell Miller became a part of Peavey Company in 1958, Sullivan continued her research and executive positions with Peavey while worked in food processing to create new products. When Sullivan left Peavey in 1967, she co-created an agribusiness consulting company called Experience Inc. During her time with Experience Inc. Sullivan held various positions including president in 1969 and director in 1975 before her 1992 retirement.
Awards and honors
In 1948, Sullivan became the first woman to be awarded the Osbourne Medal by the American Association of Cereal Chemists. Sullivan was also awarded the Garvan–Olin Medal in 1954 by the American Chemical Society.
Death
On 25 December 1999, Sullivan died in Bloomington, Minnesota.
References
1902 births
1999 deaths
Recipients of the Garvan–Olin Medal
American women chemists
Food chemists
20th-century American women
20th-century American chemists
University of Paris alumni
Chemists from Minnesota | Betty Sullivan | [
"Chemistry"
] | 525 | [
"Food chemists",
"Food chemistry"
] |
62,019,988 | https://en.wikipedia.org/wiki/Surface%20Neo | The Surface Neo is an unreleased dual-touchscreen 2-in-1 PC that was unveiled by Microsoft on October 2, 2019. Slated to be part of the Microsoft Surface family of devices, the Surface Neo was designed to be used in various "postures" for different use cases and multitasking scenarios involving its screens, and feature Windows 10X—a variant of Windows 10 designed exclusively for dual-screen devices. However, as of December 2023, over four years after the Surface Neo was announced, it is still unreleased, likely rendering it vaporware.
The Surface Neo was expected to be launched in late-2020, alongside a range of other Windows 10X devices from third-party manufacturers. In May 2020, Microsoft postponed the release of Windows 10X-based dual-screen devices in favor of launching it with single-screen devices instead. This did not come to fruition, and Microsoft eventually cancelled Windows 10X outright in May 2021, with aspects of 10X repurposed for the mainstream Windows 11. Its sister device, the Android-based Surface Duo, was released in September 2020.
Background
Microsoft had first envisioned a dual-touchscreen device with its Courier concept, while rumors surfaced in 2017 of a similar project codenamed "Andromeda"—a foldable device which would use electronic paper displays.
During a Surface hardware event on October 2, 2019, Microsoft unveiled a pair of dual-touchscreen devices—the Android-based Surface Duo smartphone, and the Surface Neo. Codenamed "Santorini", head of Windows Client Experiences Joe Belfiore explained that "we saw an opportunity both at Microsoft and with our partners to fill in some of the gaps in [laptop and tablet] experiences and offer something new". Microsoft unveiled an accompanying operating system known as Windows 10X, and stated that the OS, as well as dual-screen devices from Microsoft and other OEM partners, would be released in late-2020.
Specifications
Hardware
Microsoft did not provide any specific information on the specifications of the Surface Neo, except that all Windows 10X devices launching in 2020 would use Intel "Lakefield" processors. Prototypes of the Neo reportedly used an Intel Core i5-L16G7 processor with 8 GB of RAM, and had dual 9-inch 1440p displays.
Software
The Surface Neo was planned to run Windows 10X, an edition of Windows 10 designed exclusively for dual-touchscreen and folding devices. It featured noticeable changes to the Windows user interface, including a centered taskbar, and an updated Start menu using a grid of pinned applications (as opposed to Windows 10's existing "live tiles"). It also contained architectural differences, including having Win32 software running within a sandbox environment for security reasons, and to control power consumption (with apps automatically paused after a period of inactivity).
The OS was designed to respond to various "postures", such as spanning an application across both screens like a book, using separate applications on the two screens, standing up with a wireless external keyboard ("portable all-in-one"), or like a laptop—with the lower screen dedicated to a virtual keyboard or partially covered by a physical keyboard accessory. In both cases, the portion of the lower screen not used by the keyboard would contain the "Wonder Bar" (comparable to the "touch bar" of MacBook Pro laptops of the era), which could be used for functions such as an emoji picker, note taking, or video. It could also be used like a laptop touchpad.
Vice President of Experiences and Devices Joe Belfiore stated that Windows 10X was "evolving the core of Windows 10", and that Microsoft was "working to take the best of the applications that people need and use most — things like Mail, Calendar, and PowerPoint — and bring them over to dual screens in a way that creates flexible and rich experiences that are unique to this OS and devices".
Aborted release
In May 2020, amid the COVID-19 pandemic, Microsoft changed its plans for Windows 10X; chief product officer for Microsoft Windows and Office Panos Panay announced that Microsoft and its partners planned to launch Windows 10X with only single-screen devices, stating that "we need to focus on meeting customers where they are now", and would "continue to look for the right moment, in conjunction with our OEM partners, to bring dual-screen devices to market". However, this did not occur, and Windows 10X was ultimately cancelled the following year. Aspects of the OS were eventually incorporated into Windows 11.
Microsoft released the Surface Neo's Android counterpart, the Surface Duo, in September 2020, but the Neo was quietly shelved, with no confirmation from Microsoft beyond the postponement of dual-screen devices and the cancellation of its planned operating system. Reports from testers indicated that the Neo felt cramped to use in a laptop posture due to its 9-inch displays, and that the prototype models were prone to overheating.
In a 2022 interview, Microsoft chief product officer Panos Panay stated of devices such as the Surface Neo that "Whether it’s two screens or a foldable, I do think these are realities to the future of products being made, no doubt. Or a rollable for that matter, a rollable screen. It’s maybe not something I’ve decided on, but for sure how do we serve the form factor that’s going to adapt to the person I think is the way to think about it."
Timeline
References
Microsoft Surface
Vaporware | Surface Neo | [
"Technology"
] | 1,135 | [
"Computer industry",
"Vaporware"
] |
62,020,761 | https://en.wikipedia.org/wiki/Microcracks%20in%20rock | Microcracks in rock, also known as microfractures and cracks, are spaces in rock with the longest length of 1000 μm and the other two dimensions of 10 μm. In general, the ratio of width to length of microcracks is between 10−3 to 10−5.
Due to the scale, microcracks are observed using microscope to obtain their basic characteristics. Microcrack formation provides insights into the strength and deformation behavior of rocks. Experimental and numerical results both play an important role in studying microcracks, especially their kinematics and dynamics. Microcracks in rock have been studied to understand geologic problems such as the early stage of earthquakes and fault formation. In engineering, microcracks in rock have been linked to underground engineering problems, such as deep geological repository.
Types
In general, microcracks in rock can be subdivided into four groups:
Grain boundary cracks: microcracks are along the grain boundary.
Intragranular cracks: microcracks are within a grain. In addition, intragranular cracks along a cleavage plane are cleavage cracks.
Intergranular cracks: microcracks are along the boundaries of two or more grains.
Transgranular cracks: microcracks are across the grains or are across the grains from a grain boundary. They are the most abundant in rock specimens in the experiment.
Characteristics
The characteristics of microcracks are orientation, length, width, aspect ratio, number, and density. These characteristics have been tried to be explained by mathematical functions. For example, distribution of microcrack lengths away from the fault has been described by lognormal or exponential distributions.
Orientation
The orientations of microcracks are random in unstressed rock. Once a rock has been stressed, the microcracks will have a trend of orientations more or less parallel to the maximum applied stress or the fault strike. For example, the average orientation of microcracks of stressed Westerly granite is 30° to the fault strike.
Length, width, and aspect ratio
In a thin section, the observed length and width may not necessarily be the true length and width of a microcrack in three dimensions. The aspect ratio is the ratio of width to length. It is generally10−3 to 10−5. The crack length increases with increasing maximum applied stress, resulting in a decrease in the aspect ratio.
Number and density
Density of microcracks can be either the number of microcracks per unit area or per grain or the microcrack length per unit area. Densities of microcracks near a fault are dramatically high, but they decrease rapidly within a few mineral grains away from a fault.
Formation mechanism
Microcracks in rock can be induced by the applied stress or temperature.
Mechanically induced
A microcrack is formed when the stresses exceed the local strength of grains. The strength of materials is the ability to resist an applied load so that failure will not occur. The intrinsic properties of rock such as mineralogical heterogeneity give diverse types of mechanically induced microcracking. The following mechanisms have strong correlations to the locations that allow stress concentration in grain-scale.
Twin induced microcracking: stresses are concentrated at twin lamella.
Kink band and deformation lamellae associated microcracking: kink bands and deformation lamella can become a zone for stored strain energy to be concentrated.
Cleavage separations: cleavage planes are the weaknesses in crystals. Therefore, stresses are likely to be concentrated on these weakness planes first.
Microcracking from stress concentrations at grain boundaries: the contacts between grain boundaries provide space for stresses to be concentrated, especially tensile stresses.
Microcracking from stress concentrations around cavities: pre-existing cracks and pores within a grain allow stress concentration. This kind of stress concentration depends on the orientation and geometry of these pre-existing microcavity, as well as the mechanical properties of the surrounding material.
Elastic mismatches induced microcracking: each mineral type has its own elastic property. When two distinct minerals have a good contact between their boundaries, the applied stress will pull the stiffer mineral's boundary away from the contact. Therefore, the formed microcracks in the stiffer mineral are extensional cracks.
Grain translations and rotations: in crystalline rock, sliding along grain boundaries can be induced from deviatoric stresses, resulting grain boundary cracks. In clastic rock, the grains may be rotated by neighbor grains, forming cracks in the cement or along the grain boundary.
Thermally induced
Thermally induced microcracking refers to microcrack formation due to thermal effects. Heating or cooling can cause thermal expansion or contraction between grains, respectively. Minerals with different thermo-elastic properties have different reactions to cooling or heating, resulting in microcrack formation. Also, thermal gradients at internal boundaries of grains may also allow stress concentration, thus forming microcracks.
Evolution
The evolution of microcracks has been studied through experiment. When force is applied to a rock sample, microcracks initially form randomly in space. They then become more and more localized and intense with continuous loading. This phenomenon is called the crack localization. A theory of failure helps to explain the evolution of microcracks with increased loading:
The formation of microcracks starts at pre-existing microcracks.
The newly formed microcracks grow in size individually.
The number of growing microcracks also increases.
The growing microcracks starts interaction as more and more cracks form and grow.
The growth of the microcracks suddenly becomes intense and localized, leading to macroscopic failure.
After failure, the overall microcrack density increases near the fault and decreases rapidly away from the fault. In addition, the density of transgranular cracks increases near the fault, whereas the density of grain boundary cracks is lower. Connecting locally dense crack regions, crack arrays, and grain boundary eventually forms a macrocrack.
Before forming a fault, there is a fracture process zone (FPZ). It is a region of microcracks near the tip of a rock failure. It is associated with the crack localization and related to energy dissipation. The size of a fracture process zone is related to the specimen size. The larger the specimen size, the large the size of the fracture process zone. This relationship no longer exists when the specimen size is larger than a certain size.
The heterogeneity of rock makes the microcracking behavior much more complicated than other simple materials. Factors controlling microcracking behavior still have been identified and studied:
Rock type and composition: rock types can be classified into crystalline rocks including igneous rocks and metamorphic rocks, as well as sedimentary rocks including clastic and chemical sedimentary rocks. For example, many studies show that quartz content of a rock has a great impact on the number of microcracks.
Pre-existing weaknesses: they are already in rock, for example, cleavage planes of minerals, pores, and cracks.
Stress state: the state of a rock experiencing the stresses.
Recovery
In addition to microcracks formation, microcracks in rock can be recovered either by microcrack closure or microcrack healing. Microcrack recovery will directly cause a decrease in permeability of rock.
Microcrack closure
It can be either caused by increase in the applied stress or decrease in the effective stress. For example, microcracks perpendicular to the maximum stress direction will close. However, in nature, parts of a microcrack can be in different directions. For this reason, it will result in incomplete closure that some parts of the microcrack are closed while some parts are still open.
Microcrack healing
It is driven by transportation of chemical fluid in microcracks. For example, healing of microcracks in quartz is activated by temperature. Healing in quartz becomes fast when the temperature is above 400 °C. The rate of healing also depends on the crack sizes. The smaller the cracks, the faster the healing.
Influence
Microcracks affect the properties of rock including stiffness, strength, elastic modulus, permeability, fracture toughness, and elastic wave velocity.
Methodology to study microcracks
Studies of microcracks are focused on their distributions of the characteristics and microcracking behavior. Many experiments to study microcracks in rock have been conducted in the past decades, whereas numerical study also has been widely used to study microcracks in recent years because of the technology development. These studies have been used to compare with natural conditions.
Experimental study
Experimental study is to analyze the rock specimens that have been subjected to applied stress in laboratory. There are two popular methods to study microcracks. Observation of thin section using microscope is to obtain the distributions of microcrack lengths, widths and aspect ratios, numbers and densities, as well as orientations. Another method is using acoustic emission to detect and monitor microcrack growth. Experimental results can help scientists develop numerical models, such as simulation of fracture pattern growth.
Many experiments on rock fracture mechanism have been done in laboratory, but these experiments may have different requirement of specimen configuration and loading scheme. They are the two important factors controlling microcracking behavior such as microcrack development.
Specimen configuration
Specimen configuration refers to the dimensions of a specimen and its man-made crack. Rock samples are usually obtained from rock cores. Therefore, cylinder shape, chevron-bend shape, and semi-circular-bend shape (SCB) are the common specimen shapes used in experimental study. For example, a semi-circular bend specimen has a man-made crack, called a notch. It is used to control the morphology of rock fracture. Two notch types can be induced: a straight-through notch or a chevron notch. A straight-through notch semi-circular-bend (SNCCB) specimen has a flat-ended notch, whereas a chevron notch semi-circular-bend (CNSCB) specimen has a V-shaped opening to the air.
Loading scheme
In fracture mechanics, there are three types of loading modes to make a crack able to propagate. They are mode I (opening), mode II (in-plane shear), and mode III (out-plane shear). These loading modes can be achieved by the designed loading scheme. Mode I fractures are the most common microcracks in rock in natural.
Acoustic emission
An acoustic emission (AE) is a high-frequency elastic wave. It is generated from microcrack formations, and is correlated to rapid microcrack growth. Acoustic emission sensors are attached to the surface of the specimen. They collect the signals generated during microcrack formation. The data can be used to describe the microcrack behavior. Noted that one detected acoustic emission event is not necessary to be one microcrack formation.
The types of data collected from acoustic emission sensors are:
Acoustic emission count and acoustic emission count rate: the acoustic emission count is the number of acoustic emission events detected, whereas the acoustic emission count rate is the acoustic emission count per unit time.
Acoustic emission waveform: an acoustic emission waveform includes the delay time, threshold level, triggered time, duration time, and maximum amplitude.
These two types of data imply the following information:
Event counting: acoustic emission counting events over time can be compared with measured quantity, such as stress and strain.
Source location: the source location of an acoustic emission event can be obtained from multiple measurement of waveforms of the same acoustic emission event.
Energy release and the Gutenberg-Richter relation: it is used to describe a relationship between magnitudes of earthquakes and their numbers, but it is also representative of the acoustic emission energy if more sensors have been used.
Source mechanism: if the polarity of the initial P wave motion has been recorded at several sensors, source mechanism can be analyzed from a fault plane solution .
Limitation
Observation of microcracks under microscope: microcracks sometimes are difficult to be distinguished. For example, it is difficult to distinguish intergranular cracks from intragranular cracks. It is also difficult to tell whether it is single transgranular crack or a multi-intragranular cracks that are connected. Also, the length of an intergranular crack may include the lengths of grain boundary cracks. The lengths and widths of microcracks are recorded from a two dimensional perspective. It may not totally reflect their true dimensions.
Variations of experimental results from different specimen configuration and loading scheme: there are several specimen configurations and loading schemes. Using different configuration and loading scheme, fracture properties of the same rock including microcrack behavior can be various. The most suitable specimen configuration and loading scheme are still on debate.
Numerical study
Numerical study is used to help understanding the complicated rock mechanics problems. Four types of models using in modelling microcracks in rock are particle-based models, block-based models, grain-based models, and node-based models. Since grain-based models can consider all types of microcrack, they are good at understanding microcracking behavior.
Geological implication
Experimental study of microcracks provides insights into faulting and microcracks formation in nature. Microcracks studies with CL and fluid-inclusion studies are able to reconstruct the growth of fractures from microcracks. Population of microcracks is useful to distinguish whether the detachment is due to landslide or tectonic in origin. The fracture process zone (FPZ) can be used to understand the permeability of fault zones which controls fluid flow. Therefore, microcracks can be useful for assessing the stress history or fluid movement history of rock. Acoustic emission from microcrack growth may help to understand earthquakes.
Implications of underground engineering problems
Microcracks can affect the thermal and transport properties of rock. Studies of microcracks in rock provide an important insights into underground engineering problems as follows:
Deep geological repository
A deep geological repository is an underground repository for radioactive waste disposal, such as nuclear fuel. It is at depth of hundred metres in a stable rock mass. Deep geological repositories are all over the world, such as the United States (WIPP) and Finland (Olkiluoto Nuclear Power Plant).
Geothermal reservoir
A geothermal reservoir is one of the three components of a geothermal system that acts an energy source. It is a porous and permeable rock mass so that convection of trapped hot water and steam and recharge of heat supply can occur. The ideal geothermal reservoir is a highly permeable, fractured rock matrix.
Hydrocarbon reservoir
A hydrocarbon reservoir is an underground reservoir that keeps hydrocarbons trapped inside. Reservoir rocks have high porosity and permeability while the surrounding rocks that act as barriers have low permeability. Therefore, hydrocarbons that exist as liquid and/or gas can only stay in the reservoir rocks.
Underground storage of CO2
Underground storage of CO2 is a solution to remove CO2 in the atmosphere. It is composed of porous rocks surrounded by nonporous rocks so that it can trap the CO2 for a long time. A depleted oil and gas reservoir that is out of energy source is one of the examples used for underground storage.
See also
Fracture (geology)
Fracture mechanics
Acoustic emission
References
Petrology
Rock mechanics
Fracture mechanics | Microcracks in rock | [
"Materials_science",
"Engineering"
] | 3,160 | [
"Structural engineering",
"Materials degradation",
"Materials science",
"Fracture mechanics"
] |
62,023,753 | https://en.wikipedia.org/wiki/Gulf%20Conformity%20mark | Gulf Conformity mark, also known as G-mark is a certification mark used to indicate products that conform to all technical regulations of the Gulf Cooperation Council. It means that the G-marked products meet all requirements of the corresponding technical regulations and have passed all conformity assessment procedures. The mark was introduced in 2009.
References
Certification marks | Gulf Conformity mark | [
"Mathematics"
] | 68 | [
"Symbols",
"Certification marks"
] |
62,023,816 | https://en.wikipedia.org/wiki/Cornelius%20de%20Vos | Cornelius de Vos or de Vois or Devosse (fl. 1565-1585), was a Dutch or Flemish mine entrepreneur and mineral prospector working in England and Scotland. He was said to have been a "picture-maker" or portrait artist. De Vos is known for gold mining in Scotland and founding saltworks at Newhaven near Edinburgh.
Career
In 1558 Cornelius de Vos was in London, and married Helen, the widow of a butcher, Nicholas Howe, and John Gylmyne. He was recorded as a member of the French church in Farringdon in 1568.
De Vos was granted rights to mine and make copperas and alum in England on the Isle of Wight and in Devon by letters patent in 1564, and pursued mining concessions in Ireland. According to his rival for Irish mining rights, William Humfrey, Cornelius de Vos obtained patents for mine drainage methods previously granted to Burchard Kranich. He worked for James Blount, 6th Baron Mountjoy at Canford Cliffs in Dorset, with little success.
Searching for Scottish gold
Cornelius de Vos was a shareholder in the English Company of Mines Royal. He went prospecting for gold in Crawford Muir in Scotland in 1566. There was already competition, Mary, Queen of Scots and Lord Darnley had granted a concession to three Edinburgh burgesses, James Carmichael the warden of the mint, Master James Lyndsay, and Andrew Stevenson, while the mint-master John Acheson and John Aslowan were already working in Wanlockhead and Glengonnar.
In October 1566 Cornelius de Vos arrived in Keswick in Cumbria with an English and a Scottish partner (whose names are unknown). He brought a sample of sand in a napkin from the Scottish gold fields, found by a woman worker washing for gold, a "mayde of Scotlande". The German miners at Keswick tested the sample and told him the sand was rich in gold. The supervisor at Keswick, Thomas Thurland, noted this as suspicious activity, possibly against his or Company interests, and reported it to William Cecil. Thurland also wrote to Queen Elizabeth in alarmist terms about "secret practices with merchant strangers and by some foreign princes to have of the Scottish queen (Mary, Queen of Scots) the mines in Crawford Moor nigh adjoining to your majesty's west borders", mines he hoped to work himself. Thurland was in a partnership with a German miner, Daniel Houghstetter or Hechstetter, between 1565 and 1577, with 24 investors.
The Company of Mines Royal tried to get an interest in Scottish gold mining and panning from Mary, Queen of Scots. Meanwhile, Cornelius de Vos and his business partners, two London merchants Anthony Hickman and John Achillay, gained a permit to work salt at Newhaven from Mary and the Earl of Bothwell shortly after their marriage in May 1567. These salt works were revived by Eustachius Roche in 1592.
De Vos was awarded a traditional 19 year "tack" of the gold mines by Regent Moray in 1568. Cornelius appeared before the Privy Council of Scotland on 4 March 1568 to register his exclusive contract to work all the gold and silver mines in Scotland. He was obliged to start work before June 1569. If any lead, tin, or copper was found he was to extract it and pay the profits to the Scottish crown. For every hundred ounces of native gold or silver he was to pay eight ounces to the treasury, and four ounces for any metal that needed to be refined. He set up his own joint-stock company to recover the gold. Cornelius however still lacked knowledge of chemistry and mineralogy and, as reported by George Nedham, again had to send one of his workers, a Dutch miner called Rennius, to Daniel Hechstetter at Keswick to assay samples of sand.
Digging at Crawford Moor continued, but Regent Morton was unhappy with the contract. In June 1574 Morton went to Crawford Moor in person to see the workings and set miners to work. Cornelius de Vos approached the English ambassador Henry Killigrew in August 1574 with a message for William Cecil about the mines, presumably seeking investment and sponsorship. On 7 February 1575 Morton lent £500 to Cornelius de Vos and his three German or "Almain" partners, Abraham Peterson, Johnne Kelliner, and Helias Clutene.
In June 1575 Morton wrote to James MacGill of Nether Rankeillour, who was now Lord Clerk Register, who had witnessed the 1568 contract. He described the terms of his contract as "captious and doubtful in many points and nothing to the king's profit". Soon after, the mining concession was granted to one of de Vos' partners Abraham Peterson in February 1576.
In 1580, although he had lost his political power, Morton received gold which was coined to the value of £678, possibly connected with mining. The goldmining concession was given to Thomas Foulis in 1594.
In London his relationship with Margriete van der Eertbrugghe came into scrutiny by the Dutch Church in October 1570. In 1573 he is known to have written letters to the Mayor of London, Lionel Duckett, and others via his cousin Arnold. As he is linked with the painter Arnold van Bronckorst in Stephen Atkinson's story, it has been suggested that this Arnold was the same person.
A "Cornelis Clewtinge de Vos" , Dutchman, was buried at St Nicholas Acons in London on 11 December 1586, who was perhaps this mining entrepreneur. The name "Clewtinge" seems to be the surname of Helias Clutene, the partner of Cornelius in 1575. Mine entrepreneurs in Scotland of the next generation included George Douglas of Parkhead, George Bowes, and Bevis Bulmer.
Stephen Atkinson's account of Cornelius de Vos in Scotland
In 1619 an English gold prospector Stephen Atkinson wrote a kind of historical prospectus for gold mining in Scotland. This includes the story of "Master Cornelius" or "Cornelius Devosse". Atkinson described Cornelius Devosse as "a most cunning picture maker, and excellent in art for the trial of mineral and mineral stones", although the archival record of his activity shows that he lacked lapidary or chemical knowledge and no other source mentions him as portrait painter. According to Atkinson, the painter Nicholas Hilliard invested in the Scottish gold mine with another painter Arnold Bronckhorst. The historian Elizabeth Goldring dates Hilliard's involvement to the years 1573 or 1574.
Atkinson's narrative seems in part based on hearsay but he describes using a "book of record" of Cornelius de Vos' mining operation at Crawford Moor and a record of the works of George Bowes. This seems to have been an account of wages. Atkinson says that he himself had worked with Daniel Hechstetter, the miner who Cornelius de Vos had consulted at Keswick. He wrote that Nicholas Hilliard, then still alive, would confirm that he also lost money in the venture.
Atkinson states that Cornelius de Vos went into Scotland with a recommendation from Elizabeth I of England, was given permission to prospect and found rich ore, which describes the events of October 1566. He gives the names of four partners in the enterprise; the Earl of Morton, "Robert Bellenden (Secretary of Scotland)" perhaps intending John Bellenden (Lord Justice Clerk), Abraham Peterson a Dutch man residing in Edinburgh, and James Reid an Edinburgh burgess.
Cornelius de Vos and his partners raised capital and he was given a commission by Regent Moray, (in March 1568). Atkinson says that Cornelius had 120 men at work and employed men and women, "lads and lasses, idle men and women", who had been begging before. Most of the gold was bought by the Scottish mint for coins. The mines were apparently worked by sub-contractors. Atkinson mentions a Scottish workman John Gibson of Crawford town who worked at "Glengaber Water" (Glengonnar), who he claims to have met, and another Dutch miner, Abraham Grey, who he found in the records. Grey, known as "Grey Beard", worked at Wanlockhead, (and sometimes said to be the same person as Abraham Peterson). Regent Morton had a basin made of Wanlockhead gold and presented it to the king of France, apparently to advertise Scotland's mineral wealth.
Atkinson takes up the subject of Cornelius de Vos again, as a story from the reign of Elizabeth, "some forty years past", after describing his own recent personal involvement with Scottish gold, Hilderston silver, and John Murray of the Bedchamber. In this version, a young Cornelius persuaded his friend the painter Nicholas Hilliard to join his Scottish goldmining venture. Hilliard sent his associate, Arnold Bronckhorst, a painter and mineralogist, into Scotland. Hilliard's efforts and influence secured a patent for Cornelius de Vos, (perhaps meaning a letter of recommendation from Elizabeth to Morton). Atkinson then describes Cornelius de Vos exporting gold ore for assay. Arnold Bronckhorst was intended to be the agent for selling the gold to Scottish mint in Edinburgh but failed to secure a contract. He was, however, appointed to be the royal portrait painter.
Bronckhorst was officially appointed as royal painter in Scotland in 1581, a few years after the goldmining events Atkinson described. However, portraits made during the years of Morton's regency have been attributed to him. Several of the individuals named by Atkinson appear in the record. Abraham Peterson, the partner and successor of Cornelius de Vos, was a Dutch or Flemish metal worker or artist, as well as a mining entrepreneur, who worked in the Scottish mint and designed coins for Regent Morton, including placks and bawbees in April 1576. James Reid, who Atkinson identified as a partner of Cornelius de Vos, stood security with James Skathowie of the Canongate for the £500 loan from Regent Morton in 1575. Cornelius never repaid this loan, and after Morton was executed in 1581, Reid and Skathowie's heirs were liable to repay the money to the Earl of Lennox.
References
External links
Contract to Cornelius de Vos and partners to make salt, signed by Mary, Queen of Scots and her husband James Hepburn, Duke of Orkney
BBC News: Mary Queen of Scots documents found at Museum of Edinburgh
Mining engineers
Gold mines in Scotland
Flemish metallurgists | Cornelius de Vos | [
"Chemistry",
"Engineering"
] | 2,191 | [
"Metallurgists",
"Mining engineering",
"Flemish metallurgists",
"Mining engineers"
] |
62,023,864 | https://en.wikipedia.org/wiki/Riverbank%20Publications | The Riverbank Publications is a series of pamphlets written by the people who worked for millionaire George Fabyan in the multi-discipline research facility he built in the early 20th century near Chicago. They were published by Fabyan, often without author credit. The publications on cryptanalysis, mostly written by William Friedman, with contributions from Elizebeth Smith Friedman and others, are considered seminal in the field. In particular, Publication 22 introduced the Index of Coincidence, a powerful statistical tool for cryptanalysis.
List of publications on cryptography
The Riverbank Publications dealt with many subjects investigated at the laboratories. The ones dealing with cryptography began with number 15,
and consists of:
15, A Method of Reconstructing the Primary Alphabet From a Single One of the Series of Secondary Alphabets, 1917
16, Methods for the Solution of Running-Key Ciphers, 1918
17, An Introduction to Methods for the Solution of Ciphers, 1918
18, Synoptic Tables for the Solution of Ciphers and A Bibliography of Cryptographic Literature, 1918
19, Formulae for the Solution of Geometrical Transposition Ciphers, written with Capt. Lenox R. Lohr, 1918
20, Several Machine Ciphers and Methods for their Solution, 1918
21, Methods for the Reconstruction of Primary Alphabets, written with Elizebeth Smith Friedman, 1918
22, The Index of Coincidence and Its Applications in Cryptography, imprint L. Fournier, Paris, 1922
50, The production and detection of messages in concealed writing and images, by H. O. Nolan, 1918
75, Memorization Methods: Specifically Illustrated in Respect to Their Applicability to Codes and Topographic Material, by H. O. Nolan, 1919,
Except as noted, the above publications were written by William F. Friedman and were published by George Fabyan's Riverbank Laboratories in Geneva, Illinois.
References
Cryptography books
World War I-related lists
Cryptographic attacks
Riverbank Laboratories | Riverbank Publications | [
"Technology"
] | 393 | [
"Cryptographic attacks",
"Computer security exploits"
] |
62,024,401 | https://en.wikipedia.org/wiki/3-Methyluridine | The chemical compound 3-methyluridine, also called N3-methyluridine, is a pyrimidine nucleoside (abbreviated m3U). In living organisms it is present as RNA modification which has been detected in 23S rRNA of archaea, 16S and 23S rRNA of eubacteria, and 18S, 25S, and 28S of eukaryotic ribosomal RNAs.
See also
5-Methyluridine
References
Nucleosides
Pyrimidinediones | 3-Methyluridine | [
"Chemistry"
] | 109 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
62,025,272 | https://en.wikipedia.org/wiki/Gabronite | Gabronite or Gabbronite is a former name for a mineral found in Norway, no longer widely used. It describes a form of scapolite or nepheline.
Current views
Mindat.org defines the term "Gabbronite" as:
Old discredited name, has been referred to as both Scapolite and Nepheline. [Clark, 1993, 249 - "Hey's Mineral Index - 3rd Edition"]
Wiktionary defines "Gabbronite" as "A compact variety of scapolite, resembling gabbro."
The term is sometimes used in modern geological descriptions. Thus a description of the Matamec Ecological Reserve in Quebec, Canada says, "Elsewhere, igneous rock is composed of anorthosite, gabronite and granite."
A web search is likely to show a polished mostly-black stone used in jewelry.
Descriptions
William Phillips (1773–1828) lists the mineral under SILEX, and describes it as follows:
According to Parker Cleaveland (1780–1858) the mineral is probably a variety of Fettstein.
Cleaveland defines it as follows:
Webster's 1828 English Dictionary gives:
GA'BRONITE, n. A mineral, supposed to be a variety of fettstein. It occurs in masses, whose structure is more or less foliated, or sometimes compact. Its colors are gray, bluish or greenish gray, and sometimes red.
Armand Dufrénoy (1792–1857) describes the mineral as:
Gabronite. – This mineral, found only in Arendal in Norway, is found in an amorphous mass, with a compact or hard lamellar texture... The École des Mines possesses a sample in which I have been able to recognize not only that the angles are straight, but that there is a diagonal cleavage at an angle of about 135°; from which it follows that the prism is square, as in wernérite [common scapolite]: the shine of gabronite is fat and oily. Its color is dirty gray, greenish gray; it barely scratches glass: its specific gravity is 2.74. The composition of gabronite, which I will give in a few lines, departs from that of wernérite by the great quantity of soda it contains. This circumstance induced M. Beudant to associate it with nepheline; but the six-sided prism form of this latter species is opposed to this association.
See also
Gabbronorite
Notes
Sources
Gemstones
Silicon compounds | Gabronite | [
"Physics"
] | 531 | [
"Materials",
"Gemstones",
"Matter"
] |
62,025,667 | https://en.wikipedia.org/wiki/AAindex | AAindex is a database of amino acid indices, amino acid mutation matrices, and pair-wise contact potentials. The data represent various physicochemical and biochemical properties of amino acids and pairs of amino acids.
See also
Proteinogenic amino acid
References
External links
Official AAindex website
Biological databases | AAindex | [
"Biology"
] | 63 | [
"Bioinformatics",
"Biological databases"
] |
62,025,870 | https://en.wikipedia.org/wiki/Non-Euclidean%20surface%20growth | In the field of surface growth, there are growth processes that result in the surface of an object changing shape over time. As the object grows, its surface may change from flat to curved, or change curvature. Two points on the surface may also change in distance as a result of deformations of the object or accretion of new matter onto the object. The shape of the surface and its changes can be described in terms of non-Euclidean geometry and in particular, Riemannian geometry with a space- and time-dependent curvature.
Examples of non-Euclidean surface growth are found in the mechanics of growing gravitational bodies, propagating fronts of phase transitions, epitaxial growth of nanostructures and additive 3D printing, growth of plants, and cell motility
References
Further reading
A. V. Manzhirov and S. A. Lychev, Mathematical modeling of additive manufacturing technologies, in: Proceedings of the World Congress on Engineering 2014, Lecture Notes in Engineering and Computer Science (IAENG, London, UK, 2014), 2, pp. 1404–1409.
A. D. Drozdov, Viscoelastic Structures: Mechanics of Growth and Aging (Academic Press, New York, 1998).
Non-Euclidean geometry
Surface science | Non-Euclidean surface growth | [
"Physics",
"Chemistry",
"Materials_science",
"Mathematics"
] | 259 | [
"Geometry",
"Condensed matter physics",
"Surface science",
"Geometry stubs"
] |
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