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68,500,116 | https://en.wikipedia.org/wiki/List%20of%20Chesapeake%20Bay%20rivers | This list of Chesapeake Bay rivers includes the main rivers draining into the Chesapeake Bay estuarine complex on the mid-Atlantic eastern coast of the United States, North America. The three largest rivers in order of both discharge and watershed area are the Susquehanna River, the Potomac River, and the James River. Other major rivers include the Rappahannock River, the Appomattox River (which flows into the lower James River), the York River (a combination of the Pamunkey and Mattaponi tributary rivers), the Patuxent River, and the Choptank River.
The entire Chesapeake Bay watershed includes portions of six states (New York, Pennsylvania, West Virginia, Maryland, Virginia, and Delaware) and the District of Columbia. The watershed of the entire Chesapeake Bay covers 165,760 km2 (approximately 64,000 mi2 or 41 million acres ). With an estuary water body area of only 11,600 km2 (4,479 mi2), the land-to-water ratio is about 14:1. Therefore, the rivers flowing into the Chesapeake Bay have a large influence on water quality in the estuary. The rivers flowing into the Chesapeake Bay act as sources of nutrients and sediments from land, which affect the health of the downstream estuary. The larger rivers cross the Atlantic seaboard fall line. Over time, many large cities emerged where these rivers cross the fall line as watermills allowed for the production of material goods. Colonial-era logging, farming, and later construction of mill dams have altered streams and trapped mud in much of the Chesapeake Bay watershed.
Largest rivers
[*] James values are the sums of flows and watershed areas of the James and Appomattox rivers.
[**] York values are the sums of flows and watershed areas of the Mattaponi and Pamunkey tributary rivers.
Other tributary rivers and tidal inlets
In addition to the largest rivers listed above, the following rivers drain directly into the Chesapeake Bay:
Eastern shore tributary rivers
Pocomoke River
Little Annemessex River
Big Annemessex River
Manokin River
Monie Creek
Wicomico River (Maryland eastern shore)
Nanticoke River
Transquaking River
Blackwater River (Maryland)
Honga River
Little Choptank River
Miles River
Front River
Wye River (Maryland)
Chester River
Sassafras River
Elk River (Maryland)
North East River
Principio Creek
Western shore tributary rivers
Swan Creek
Romney Creek
Bush River (Maryland)
Gunpowder River
Middle River (Maryland)
Back River (Maryland)
Patapsco River
Magothy River
Whitehall Creek (Maryland)
Severn River (Maryland)
South River (Maryland)
West River (Maryland)
Rhode River
St. Marys River (Maryland)
Little Wicomico River
Great Wicomico River
Piankatank River
East River (Virginia)
North River (Mobjack Bay)
Ware River (Virginia)
Severn River (Virginia)
Poquoson River
Back River (Virginia)
Hampton River
Elizabeth River (Virginia)
Lynnhaven River
See also
Atlantic Seaboard Fall Line
Atlantic seaboard watershed
Chesapeake Bay
Chesapeake Bay Program
Chesapeake Bay Foundation
Hydrology
List of rivers of the United States
List of rivers of Maryland
List of rivers of Virginia
Mid-Atlantic (United States)
Mississippi River System
:Category:Tributaries of the Chesapeake Bay
References
Chesapeake Bay watershed
Estuaries of the United States
Rivers of the United States
Hydrology lists | List of Chesapeake Bay rivers | [
"Environmental_science"
] | 683 | [
"Hydrology",
"Hydrology lists"
] |
68,500,212 | https://en.wikipedia.org/wiki/Immortality%20or%20Bust | Immortality or Bust is a 2019 feature documentary focusing on the 2016 U.S. presidential campaign of Transhumanist Party nominee Zoltan Istvan. Directed by Daniel Sollinger, it won two awards at film festivals - the Breakout Award at the 2019 Raw Science Film Festival and Best Biohacking Awareness Documentary at the GeekFest Toronto 2021. It is distributed by Gravitas Ventures.
Synopsis
Immortality or Bust explores the transhumanism movement and its major personalities as Zoltan Istvan drives his "Immortality Bus" across America.
The film begins with Istvan and his mother, Ilona Gyurko, mourning over the body of his father, Steven Gyurko. Months before his death, Istvan had been driving a 38-foot campaign bus shaped like a giant coffin in hopes of generating publicity for life extension science, which aims to overcome death with technologies such as genetic editing, robotic organs, and mind uploading.
Aboard the bus and featured in the documentary are embedded journalists from media such as The New York Times, The Verge, Vox, The Telegraph, and Der Spiegel.
The documentary explores biohacker gathering GrindFest, cryonics facility Alcor, Jacque Fresco's The Venus Project, and The Church of Perpetual Life, and virtual reality's Second Life via Terasem, among other places.
The documentary also features Istvan's visits with then Cyborg Party presidential candidate John McAfee, 2016 Libertarian presidential candidate Gary Johnson, and comedian Jimmy Dore. In the documentary Alex Jones and Fox News criticize Istvan's presidential campaign while Good Mythical Morning, underground group Anonymous offer support, and John Horgan at Scientific American offer support.
Immortality or Bust also focuses on Istvan's presidential campaign events, from California street demonstrations supporting transhumanism, to talks at Harvard University, to advocating for universal basic income, to delivering a Transhumanist Bill of Rights to the US Capitol. It also features Istvan's complex marriage to his wife and how his political ambitions affect his young children. The film concludes with Istvan's father voting for his son before he dies.
Cast
Zoltan Istvan
John McAfee
Gary Johnson
Alex Jones
Jimmy Dore
Max More
Jacque Fresco
William Falloon
John Horgan
Erica Orange
Rich Lee (biohacker)
Alexis Madrigal
Maitreya One (HipHop artist)
Criticism
Film Threat reviewer Chris Salce says Istvan mentions Jurassic Park themes too much in his transhumanism ideas, and that works against the overall message of the film.
References
External links
Official website
2019 films
2019 documentary films
American documentary films
Documentary films about technology
Documentary films about death
American independent films
Transhumanism
Futurology documentaries
2010s English-language films
2010s American films
English-language documentary films | Immortality or Bust | [
"Technology",
"Engineering",
"Biology"
] | 570 | [
"Genetic engineering",
"Transhumanism",
"Ethics of science and technology"
] |
68,500,274 | https://en.wikipedia.org/wiki/Morganite%20%28gem%29 | Morganite is an orange or pink variety of beryl and is also a gemstone. Morganite is mined in Brazil, Afghanistan, Mozambique, Namibia, the United States, and Madagascar.
Morganite has grown in popularity since 2010. Brides and CNN have listed it as a possible alternative to diamond for engagement rings.
Name
Following the discovery of a new locality for rose beryl in Madagascar in 1910, George Kunz proposed the name morganite at a meeting of the New York Academy of Sciences on 5 December 1910 to honour his friend and customer J.P. Morgan for his financial support for the arts and sciences, and his important gifts of gems to the American Museum of Natural History in New York and to the Museum of Natural History in Paris. Morgan was one of the most important gem collectors in the early 1900s – his collection was partly assembled by Tiffany and Company and their chief gemmologist, Kunz.
Morganite is also known as pink beryl, rose beryl, pink emerald, and "cesian (or caesian) beryl".
Characteristics
The pink color of morganite is attributed to Mn2+ ions. Morganite is pleochroic; when it is viewed down its crystallographic axis the color is more pink.
In comparison to emerald, morganite lacks inclusions and fractures, thus making it more durable than emerald.
History
Pink beryl of fine color and good sizes was first discovered on an island off the coast of Madagascar in 1910. It was also known, with other gemstone minerals, such as tourmaline and kunzite, at Pala, California. In December 1910, the New York Academy of Sciences named the pink variety of beryl "morganite" after financier J. P. Morgan.
On October 7, 1989, one of the largest gem morganite specimens ever uncovered, eventually called "The Rose of Maine", was found at the Bennett Quarry in Buckfield, Maine, US. The crystal, originally somewhat orange in hue, was long and about across, and weighed (along with its matrix) just over .
Before 2011, morganite was unknown in many jewelry stores. But, recently morganite has been increasing in popularity.
Value and popularity
According to a 2017 survey, morganite is the second most popular non-diamond stone, after sapphire. A single carat of morganite can cost about $300.
Morganite is one of the rarest members of the beryl family, second only to red beryl. Due to the scarcity of morganites, especially those of high quality, they tend to be among the most expensive per carat. Ones that are deep pink in color tend to be the most valuable.
References
Gemstones
Beryl group | Morganite (gem) | [
"Physics"
] | 553 | [
"Materials",
"Gemstones",
"Matter"
] |
68,502,608 | https://en.wikipedia.org/wiki/Nitrate%20nitrite | A nitrate nitrite, or nitrite nitrate, is a coordination complex or other chemical compound that contains both nitrite () and nitrate () anions. They are mixed-anion compounds, and they are mixed-valence compounds. Some have third anions. Many nitrite nitrate compounds are coordination complexes of cobalt. Such a substance was discovered by Wolcott Gibbs and Frederick Genth in 1857.
Production
Mercury(II) nitrate and potassium nitrate in water solution produce the salt tripotassium tetranitratomercurate(II) nitrate .
Properties
On heating, nitrate nitrites lose NO2 and NO and yield metal oxides.
Related
Other compounds having an element in two different anion states include the sulfate sulfites, the phosphate phosphites, arsenate arsenites and the selenate selenites.
List
References
Nitrates
Nitrites | Nitrate nitrite | [
"Chemistry"
] | 187 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,502,903 | https://en.wikipedia.org/wiki/NGC%206337 | NGC 6337, the Ghostly Cheerio or Cheerio Nebula, is a toroidal planetary nebula in the constellation Scorpius. It appears as a ring-shaped (annular) transparent nebula resembling a piece of the breakfast cereal Cheerios, hence the name. Filament and knots, and a faint shell surround the ring. Its magnitude is 11.90; its position in Scorpius is right ascension 17h 22m15.67s, declination -38° 29' 01.73". The Ghostly Cheerio has a redshift value of -0.000236.
There is convincing evidence that a binary nucleus exists at the center of the nebula, with masses of 0.6 and 0.3 M⊙, and a separation of ≤ 1.26 R⊙, indicating a probable common envelope phase. The Ghostly Cheerio's projected radial expansion is slow, averaging .
See also
List of NGC objects (6001–7000)
References
Scorpius
6337
Planetary nebulae | NGC 6337 | [
"Astronomy"
] | 209 | [
"Nebula stubs",
"Scorpius",
"Astronomy stubs",
"Constellations"
] |
68,502,959 | https://en.wikipedia.org/wiki/Tentai%20Show | Tentai Show (Japanese: 天体ショー tentai shō), also known by the names Tentaisho, Galaxies, Spiral Galaxies, or Sym-a-Pix, is a binary-determination logic puzzle published by Nikoli.
Rules
Tentai Show is played on a rectangular grid of squares. On the grid are dots representing stars, which can be found on the grid either on the center of a cell, an edge, or a corner.
The objective of the puzzle is to draw lines along the dashed lines to divide the grid into regions representing galaxies.
In the resulting grid, all galaxies must have 180° rotational symmetry and contain exactly one dot located at its center.
The colors of the dots do not affect the logic of the puzzle and can be ignored when solving. In puzzles with multiple colored dots, the regions of the finished grid may be colored with the corresponding dot colors to reveal a picture.
Solution Methods
Tentai Show puzzles can be solved using the following steps.
Draw walls between adjacent cells that contain a dot or a fraction of a dot. These cells must belong to different galaxies.
Draw walls around the dot according to rotational symmetry. Borders of the grid also count as walls.
Find cells in areas that are 'captured' by a dot. These are cells which cannot be reached by any other dot. These cells can only belong to the galaxy for that dot.
The above steps can be repeated until the puzzle is solved.
In more advanced puzzles, it may be necessary to consider the image of rotational symmetry. Find cells which only have one valid dot when considering its rotationally symmetric cell. A cell can belong to a galaxy if its symmetric cell can also belong to that galaxy.
History
The name of the puzzle, "Tentai Show", has a double meaning when interpreted in Japanese. "Ten" (点) stands for dot, while "tai shō" (対称) stands for symmetry. The Japanese word "Tentai" (天体) is used to refer to astronomical objects. When combined, "Tentai Show" can both mean rotational symmetry and astronomical show.
Computational Complexity
NP-Completeness
Determining whether a Tentai Show puzzle has a solution is known to be NP-complete. This was proven by Friedman (2002) by constructing puzzles equivalent to arbitrary Boolean circuits, which shows NP-completeness because of the Boolean satisfiability problem.
Fertin, Jamshidi, and Komusiewicz (2015) strengthened this result by proving the puzzle is NP-complete when all galaxies have size at most seven. The proof reduces the puzzle to Positive Planar 1-in-3-SAT, which is known to be NP-complete.
Demaine, Löffler, and Schmidt (2021) further strengthened this by proving NP-completeness even if all galaxies are restricted to be rectangles of sizes 1×1, 1×3, or 3×1.
They also showed that finding a minimal set of galaxies that exactly cover a given shape is NP-complete.
Solution Algorithms
Tentai Show puzzles can be solved in exponential time by going through all possible dissections of the grid and checking if it is a valid solution.
Fertin, Jamshidi, and Komusiewicz (2015) showed a polynomial-time algorithm that can solve the puzzle for various cases, such as: (a) when all galaxies have size at most two, (b) when all galaxies are squares, and (c) when all galaxies are trivially connected.
See also
List of Nikoli puzzle types
References
Logic puzzles
NP-complete problems
Japanese board games | Tentai Show | [
"Mathematics"
] | 731 | [
"NP-complete problems",
"Mathematical problems",
"Computational problems"
] |
68,503,642 | https://en.wikipedia.org/wiki/Research%20Policy%20%28journal%29 | Research Policy is a monthly peer-reviewed academic journal published by Elsevier on behalf of the Science Policy Research Unit. It was established by British economist Christopher Freeman in 1971 and is regarded as the leading journal in the field of innovation studies. It is listed as one of the 50 journals used by the Financial Times to compile its business-school research ranks.
Content
The journal covers a wide range of subjects such as technological change, R&D, management of knowledge, entrepreneurship, science policy, and multiple subfields relating to innovation studies (e.g., innovation economics, innovation management, technology innovation). It is a top-ranked or top-cited journal in the fields of business and economics, management, technology and innovation management (TIM), academic entrepreneurship, and technology assessment.
History
Based on research conducted by Joseph Schumpeter, Freeman worked to demonstrate the importance of innovation and R&D for economic development. From 1959 to 1966, Freeman worked at the National Institute of Economic and Social Research, where he carried out pioneering studies on industrial research. He played an important role in the development of the OECD's Frascati Manual. In 1966, Freeman founded the Science Policy Research Unit at the University of Sussex and became its first director. It became a global hub for innovation research and attracted scholars from across the world. Research Policy was established in 1971 with Freeman as editor-in-chief. In 1984, Keith Pavitt succeeded Freeman as the R.M. Phillips Professor of Science Policy and as the main editor of the journal, a post he would hold until his retirement in 2002.
Research Policy: X was Research Policys open access mirror journal that was discontinued in 2021.
Abstracting and indexing
The journal is indexed and abstracted in the following bibliographic databases:
According to the Journal Citation Reports, the journal has a 2022 impact factor of 7.2.
Notable studies
Notable studies published in the journal include:
References
Further reading
External links
Hybrid open access journals
Elsevier academic journals
Academic journals established in 1971
Innovation
Science and technology studies journals
Business and management journals | Research Policy (journal) | [
"Technology"
] | 423 | [
"Science and technology studies journals",
"Science and technology studies"
] |
68,503,678 | https://en.wikipedia.org/wiki/Actinium%28III%29%20nitrate | Actinium(III) nitrate is an inorganic compound, actinium salt of nitric acid with the chemical formula Ac(NO3)3. The compound looks like white substance, readily soluble in water.
Synthesis
Actinium nitrate can be obtained by dissolving actinium or actinium hydroxide in nitric acid.
Properties
Actinium(III) nitrate decomposes on heating above 600 °C:
This salt is used as a source of Ac3+ ions to obtain insoluble actinium compounds by precipitation from aqueous solutions.
References
Actinium compounds
Nitrates | Actinium(III) nitrate | [
"Chemistry"
] | 117 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,504,105 | https://en.wikipedia.org/wiki/Marine%20holobiont | The holobiont concept is a renewed paradigm in biology that can help to describe and understand complex systems, like the host-microbe interactions that play crucial roles in marine ecosystems. However, there is still little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them and their ecological consequences. The holobiont concept posits that a host and its associated microbiota with which it interacts, form a holobiont, and have to be studied together as a coherent biological and functional unit to understand its biology, ecology, and evolution.
History
The idea of holism started to regain popularity in biology when the endosymbiosis theory was first proposed by Konstantin Mereschkowski in 1905 and further developed by Ivan Wallin in 1925. Still accepted today, this theory posits a single origin for eukaryotic cells through the symbiotic assimilation of prokaryotes to form first mitochondria and later plastids (the latter through several independent symbiotic events) via phagocytosis (reviewed in Archibald, 2015). These ancestral and founding symbiotic events, which prompted the metabolic and cellular complexity of eukaryotic life, most likely occurred in the ocean.
Despite the general acceptance of the endosymbiosis theory, the term holobiosis or holobiont did not immediately enter the scientific vernacular. It was coined independently by the German Adolf Meyer-Abich in 1943, and by Lynn Margulis in 1990, who proposed that evolution has worked mainly through symbiosis-driven leaps that merged organisms into new forms, referred to as “holobionts”, and only secondarily through gradual mutational changes. However, the concept was not widely used until it was co-opted by coral biologists over a decade later. Corals and the dinoflagellate algae called Zooxanthellae are one of the most iconic examples of symbioses found in nature; most corals are incapable of long-term survival without the products of photosynthesis provided by their endosymbiotic algae. Rohwer et al. (2002) were the first to use the word holobiont to describe a unit of selection sensu Margulis for corals, where the holobiont comprised the cnidarian polyp (host), Zooxanthellae algae, various ectosymbionts (endolithic algae, prokaryotes, fungi, other unicellular eukaryotes), and viruses.
Although initially driven by studies of marine organisms, much of the research on the emerging properties and significance of holobionts has since been carried out in other fields of research: the microbiota of the rhizosphere of plants or the animal gut became predominant models and have led to an ongoing paradigm shift in agronomy and medical sciences. Holobionts occur in terrestrial and aquatic habitats alike, and several analogies between these ecosystems can be made. For example, in all of these habitats, interactions within and across holobionts such as induction of chemical defenses, nutrient acquisition, or biofilm formation are mediated by chemical cues and signals in the environment, dubbed infochemicals. Nevertheless, we can identify two major differences between terrestrial and aquatic systems. First, the physicochemical properties of water result in higher chemical connectivity and signaling between macro- and micro-organisms in aquatic or moist environments. In marine ecosystems, carbon fluxes also appear to be swifter and trophic modes more flexible, leading to higher plasticity of functional interactions across holobionts. Moreover, dispersal barriers are usually lower, allowing for faster microbial community shifts in marine holobionts. Secondly, phylogenetic diversity at broad taxonomic scales (i.e., supra-kingdom, kingdom and phylum levels), is higher in aquatic realms compared to land, with much of the aquatic diversity yet to be uncovered, especially marine viruses.
Russian Doll complexity
The boundaries of holobionts are usually delimited by a physical gradient, which corresponds to the area of local influence of the host, e.g., in unicellular algae the so-called phycosphere. However, they may also be defined in a context-dependent way as a Russian matryoshka doll, setting the boundaries of the holobiont depending on the interactions and biological functions that are being considered. Thus holobionts may encompass all levels of host-symbiont associations from intimate endosymbiosis with a high degree of co-evolution up to the community and ecosystem level; a concept referred to as "nested ecosystems" (see diagram).
In the diagram on the right, the host (blue circles), and associated microbes (all other shapes) including bacteria and eukaryotes that may be inside (i.e., endosymbiotic) or outside the host (i.e., ectosymbiotic) are connected by either beneficial (solid orange lines), neutral (solid blue lines) or pathogenic (dashed black lines) interactions, respectively. Changes from beneficial or neutral to pathogenic interactions are typical cases of dysbiosis. The different clusters are illustrated by the following examples: 1, a model holobiont in a stable physiological condition (e.g., in controlled laboratory condition); 2 and 3, holobionts changing during their life cycle or subjected to stress conditions—examples of vertically transmitted microbes are indicated by light blue arrows; 4 and 5, marine holobionts in the context of global sampling campaigns or long-term time series—examples of horizontal transmission of microbes and holobionts are illustrated by pink arrows.
Such a conceptual perspective raises fundamental questions not only regarding the interaction between the different components of holobionts and processes governing their dynamics, but also of the relevant units of selection and the role of coevolution. For instance, plant and animal evolution involves new functions co-constructed by members of the holobiont or elimination of functions redundant among them, and it is likely that these processes are also relevant in marine holobionts. Eugene Rosenberg et al. have argued that all animals and plants can be considered holobionts, and thus advocate the hologenome theory of evolution, suggesting that natural selection acts at the level of the holobiont and its hologenome. This interpretation of Margulis' definition of a holobiont considerably broadened fundamental concepts in evolution and speciation and has not been free of criticism, especially when applied at the community or ecosystem level. More recently, it has been shown that species that interact indirectly with the host can also be important in shaping coevolution within mutualistic multi-partner assemblages. Thus, the holobiont concept and the underlying complexity of holobiont systems should be better defined and further considered when addressing evolutionary and ecological questions.
Marine holobiont models
Environmental models: Within the animal kingdom, and in addition to corals and sponges, the discovery of deep-sea hydrothermal vents revealed symbioses of animals with chemosynthetic bacteria that have later been found in many other marine ecosystems and frequently exhibit high levels of metabolic and taxonomic diversity. In the SAR supergroup, in addition to well-known models such as diatoms, radiolarians and foraminiferans, both heterotrophic protist dwellers harboring endosymbiotic microalgae, are emerging as ecological models for unicellular photosymbiosis due to their ubiquitous presence in the world's oceans. Among the haptophytes, the cosmopolitan Emiliania huxleyi, promoted by associated bacteria, produces key intermediates in the carbon and sulfur biogeochemical cycles, making it an important model phytoplankton species. Finally, within the Archaeplastida, the siphonous green alga Bryopsis is an example of a model that harbors heterotrophic endosymbiotic bacteria, some of which exhibit patterns of co-evolution with their hosts.
Controlled bi- or trilateral associations: Only a few models, covering a small part of the overall marine biodiversity, are currently being cultivated ex-situ and can be used in fully controlled experiments, where they can be cultured aposymbiotically. The flatworm Symsagittifera roscoffensis, the sea anemone Exaiptasia, the upside-down jellyfish Cassiopea, and their respective intracellular green and dinoflagellate algae have, in addition to corals, become models for fundamental research on evolution of animal-algal photosymbiosis. In particular, the sea anemone Exaiptasia has been used to explore photobiology disruption and restoration of cnidarian symbioses. The Vibrio-squid model provides insights into the effect of microbiota on animal development, circadian rhythms, and immune systems/ The unicellular green alga Ostreococcus, an important marine primary producer, has been shown to exchange vitamins with specific associated bacteria. The green macroalga Ulva mutabilis has enabled the exploration of bacteria-mediated growth and morphogenesis including the identification of original chemical interactions in the holobiont. Although the culture conditions in these highly controlled model systems differ from the natural environment, these systems are essential to gain elementary mechanistic understanding of the functioning, the roles, and the evolution of marine holobionts.
Example holobionts
Influence on ecological processes
Work on model systems has demonstrated that motile and macroscopic marine holobionts can act as dissemination vectors for geographically restricted microbial taxa. Pelagic mollusks or vertebrates are textbook examples of high dispersal capacity organisms (e.g., against currents and through stratified water layers). It has been estimated that fish and marine mammals may enhance the original dispersion rate of their microbiota by a factor of 200 to 200,000 and marine birds may even act as bio-vectors across ecosystem boundaries. This host-driven dispersal of microbes can include non-native or invasive species as well as pathogens.
A related ecological function of holobionts is their potential to sustain rare species. Hosts provide an environment that favors the growth of specific microbial communities distinct from the surrounding environment (including rare microbes). They may, for instance, provide a nutrient-rich niche in the otherwise nutrient-poor surroundings.
Lastly, biological processes regulated by microbes are important drivers of global biogeochemical cycles. In the open ocean, it is estimated that symbioses with the cyanobacterium UCYN-A contribute about 20% to total N2 fixation. In benthic systems, sponges and corals may support entire ecosystems via their involvement in nutrient cycling thanks to their microbial partners, functioning as sinks and sources of nutrients. In particular the “sponge loop” recycles dissolved organic matter and makes it available to higher trophic levels in the form of detritus. In coastal sediments, bivalves hosting methanogenic archaea have been shown to increase the benthic methane efflux by a factor of up to eight, potentially accounting for 9.5% of total methane emissions from the Baltic Sea. This metabolic versatility is accomplished because of the simultaneous occurrence of disparate biochemical machineries (e.g., aerobic and anaerobic pathways) in individual symbionts, providing new metabolic abilities to the holobiont, such as the synthesis of specific essential amino acids, photosynthesis, or chemosynthesis. Furthermore, the interaction between host and microbiota can potentially extend the metabolic capabilities of a holobiont in a way that augments its resilience to environmental changes, or allow it to cross biotope boundaries (e.g., Woyke et al., 2006) and colonize extreme environments (Bang et al., 2018). Holobionts thus contribute to marine microbial diversity and possibly resilience in the context of global environmental changes and it is paramount to include the holobiont concept in predictive models that investigate the consequences of human impacts on the marine realm and its biogeochemical cycles.
Holobiont assembly and regulation
Two critical challenges partially addressed by using model systems are (1) to decipher the factors determining holobiont composition and (2) to elucidate the impacts and roles of the different partners in these complex systems over time. Some marine organisms such as bivalves transmit part of the microbiota maternally. In other marine holobionts, vertical transmission may be weak and inconsistent, whereas mixed modes of transmission (vertical and horizontal) or intermediate modes (pseudo-vertical, where horizontal acquisition frequently involves symbionts of parental origin) are more common. Identifying the factors shaping holobiont composition and understanding their evolution is highly relevant for marine organisms given that most marine hosts display a high specificity for their microbiota and even patterns of phylosymbiosis, despite a highly connected and microbe-rich environment.
During microbiota transmission (whether vertical or horizontal), selection by the host and/or by other components of the microbiome, is a key process in establishing or maintaining a holobiont microbial community that is distinct from the environment. The immune system of the host, e.g., via the secretion of specific antimicrobial peptides, is one way of performing this selection in both marine and terrestrial holobionts.
Another way of selecting a holobiont microbial community is by chemically mediated microbial gardening. This concept has been demonstrated for land plants, where root exudates manipulate microbiome composition. In marine environments, the phylogenetic diversity of hosts and symbionts suggests both conserved and marine-specific chemical interactions, but studies are still in their infancy. For instance, seaweeds can chemically garden beneficial microbes, facilitating normal morphogenesis and increasing disease resistance, and seaweeds and corals structure their surface-associated microbiome by producing chemoattractants and antibacterial compounds. There are fewer examples of chemical gardening in unicellular hosts, but it seems highly likely that similar processes are in place.
In addition to selection, ecological drift, dispersal and evolutionary diversification have been proposed as key processes in community assembly, but are difficult to estimate in microbial communities. The only data currently at our disposal to quantify these processes are the diversity and distribution of microbes. Considering the high connectivity of aquatic environments, differences in marine microbial communities are frequently attributed to a combination of selection and drift, rather than limited dispersal, a conclusion which in the future could be refined by conceptual models developed for instance for soil microbial communities.) Diversification is mainly considered in the sense of coevolution or adaptation to host selection, which may also be driven by the horizontal acquisition of genes. However, cospeciation is challenging to prove and only few studies have examined this process in marine holobionts to date, each focused on a restricted number of actors.
Perturbations in the transmission or the recruitment of the microbiota can lead to dysbiosis, and eventually microbial infections. Dysbiotic microbial communities are frequently determined by stochastic processes and thus display higher variability in their composition than those of healthy individuals. This observation in line with the "Anna Karenina principle", although there are exceptions to this rule. A specific case of dysbiosis is the so-called "Rasputin effect" where benign endosymbionts opportunistically become detrimental to the host due to processes such as reduction in immune response under food deprivation, coinfections, or environmental pressure. Many diseases are now interpreted as the result of a microbial imbalance and the rise of opportunistic or polymicrobial infections upon host stress. For instance in reef-building corals, warming destabilizes cnidarian-dinoflagellate associations, and some beneficial Symbiodiniacea strains switch their physiology and sequester more resources for their own growth at the expense of the coral host, leading to coral bleaching and even death.
Increasing our knowledge on the contribution of these processes to holobiont community assembly in marine systems is a key challenge, which is of particular urgency today in the context of ongoing global change. Moreover, understanding how the community and functional structure of resident microbes are resilient to perturbations remains critical to predict and promote the health of their host and the ecosystem. Yet, the contribution of the microbiome is still missing in most quantitative models predicting the distribution of marine macro-organisms, or additional information on biological interactions would be required to make the former more accurate.
References
Further references
Holobionts | Marine holobiont | [
"Biology"
] | 3,513 | [
"Symbiosis",
"Holobionts"
] |
68,505,120 | https://en.wikipedia.org/wiki/Fractional%20dose%20vaccination | Fractional dose vaccination is a strategy to reduce the dose of a vaccine to achieve a vaccination policy goal that is more difficult to achieve with conventional vaccination approaches, including deploying a vaccine faster in a pandemic, reaching more individuals in the setting of limited healthcare budgets, or minimizing side effects due to the vaccine.
Fractional dose vaccination exploits the nonlinear dose-response characteristics of a vaccine: If two persons can be vaccinated instead of one, but each one gets 2/3 of the protective efficacy, there is a net benefit at society scale for reducing the number of infections. If the healthcare budget is limited or only a limited amount of vaccine is available during the early phase of a pandemic, this can make a difference for the total number of infections.
Fractional dose vaccination uses a fraction of the standard dose of a regular vaccine that is administered by the same, or an alternative route (often subcutaneously or intradermally).
Fractional dose vaccination has been used or proposed in a number of relevant infectious poverty diseases including yellow fever, poliomyelitis, COVID-19.
Use
In the context of limited healthcare budgets
During the 2016 yellow fever outbreak in Angola and the Democratic Republic of the Congo, the WHO approved the use of fractional dose vaccination to deal with a potential shortage of vaccine. In August 2016, a large vaccination campaign in Kinshasa used 1/5 of the standard vaccine dose. In 2018 it was reported that fractional dose vaccination with 1/5 of the standard vaccine dose, administered intradermally, conferred protection for 10 years, as documented by a randomized clinical trial.
In Poliomyelitis, fractional dose vaccination has been shown to be effective while reducing overall cost, rendering polio vaccination available to more individuals.
In the Covid-19 pandemic
In a pandemic wave, fractional dose vaccination is considered to accelerate widespread access to vaccination when vaccine supply is limited:
In the COVID-19 pandemic, epidemiologic models predict a major benefit of personalized fractional dose vaccination strategies with certain vaccines in terms of case load, deaths, and shortening of the pandemic.
To reduce side effects
In some segments of the population, disease risk is lower but specific vaccine side effect risks may be increased. In such subpopulations, fractional dose vaccination might optimize the benefit-risk ratio of vaccination for an individuum and optimize the cost-benefit relation for society.
References
Vaccination | Fractional dose vaccination | [
"Biology"
] | 550 | [
"Vaccination"
] |
68,505,364 | https://en.wikipedia.org/wiki/Dysprosium%28III%29%20nitrate | Dysprosium(III) nitrate is an inorganic compound, a salt of dysprosium and nitric acid with the chemical formula Dy(NO3)3. The compound forms yellowish crystals, dissolves in water, forms a crystalline hydrate.
Synthesis
Anhydrous salt is obtained by the action of nitrogen dioxide on dysprosium(III) oxide:
The action of nitrogen dioxide on metallic dysprosium:
Physical properties
Dysprosium(III) nitrate forms yellowish crystals.
The anhydrous nitrate forms a crystalline hydrate in wet air with the ideal composition of , which melts in its own crystallization water at 88.6 °C.
All hydrates (anhydrous, pentahydrate, and hexahydrate) are soluble in water and ethanol, hygroscopic.
Chemical properties
Hydrated dysprosium nitrate thermally decomposes to form , and further heating produces dysprosium oxide.
Application
Dysprosium(III) nitrate is used as a catalyst.
References
Dysprosium compounds
Nitrates | Dysprosium(III) nitrate | [
"Chemistry"
] | 234 | [
"Nitrates",
"Oxidizing agents",
"Salts"
] |
68,505,526 | https://en.wikipedia.org/wiki/Americium%28III%29%20nitrate | Americium(III) nitrate is an inorganic compound, a salt of americium and nitric acid with the chemical formula Am(NO3)3. The compound is soluble in water and radioactive.
Synthesis
Reaction of americium and nitric acid:
8Am + 30HNO3 -> 8Am(NO3)3 + 3N2O + 15H2O
Chemical properties
Americium(III) nitrate thermally decomposes to form americium(III) oxide.
It forms crystal hydrates.
References
Americium compounds
Nitrates | Americium(III) nitrate | [
"Chemistry"
] | 118 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
68,507,328 | https://en.wikipedia.org/wiki/Norpsilocin | Norpsilocin, also known as 4-hydroxy-N-methyltryptamine (4-HO-NMT), is a tryptamine alkaloid recently discovered in 2017 in the psychedelic mushroom Psilocybe cubensis. It is hypothesized to be a dephosphorylated metabolite of baeocystin.
Norpsilocin was found to be a near full agonist of the 5-HT2A receptor and was found to be more potent than psilocin. It also has affinity for other serotonin receptors. Moreover, it has been found to cross the blood–brain barrier in animals and to have good metabolic stability similarly to psilocin.
Surprisingly however, norpsilocin failed to induce the head-twitch response, a behavioral proxy of psychedelic effects, in animals. Likewise, norbaeocystin and aeruginascin failed to induce the head-twitch response. Only psilocybin was effective in this regard. In any case, norbaeocystin showed antidepressant-like activity (forced swim test) similarly to psilocybin and fluoxetine in spite of its putative non-hallucinogenic nature. Norpsilocin itself was not tested in this assay.
Norpsilocin is being evaluated under the developmental code name PLZ-1017 for the possible treatment of pervasive developmental disorders in children.
See also
4-HO-NALT
4-Hydroxytryptamine
References
Experimental non-hallucinogens
Non-hallucinogenic 5-HT2A receptor agonists
Secondary amines
Tryptamine alkaloids | Norpsilocin | [
"Chemistry"
] | 348 | [
"Tryptamine alkaloids",
"Alkaloids by chemical classification"
] |
68,507,875 | https://en.wikipedia.org/wiki/Jellyfish%20Barge | The Jellyfish Barge is a floating greenhouse module that uses hydroponic agriculture and 70% less water compared to traditional agriculture. The barge is made of recyclable materials and uses solar distillation to collect 150 liters of saltwater daily and turn it into freshwater. 15% seawater is added back into the water to improve the mineral content and nutritional value of the crops. One module is approximately 70 square meters and can be used to grow between 1400 and 1600 plants per month. 120 units can be constructed on a hectare. The project was included as part of the Expo 2015 in Milan, Italy. The project was conceptualized by Stefano Mancuso and was financed by the Cassa di Risparmio di Firenze. The architects of the module are Antonio Girardi and Cristina Favretto.
References
Environmental mitigation
Hydroponics
Architectural design
Agricultural technology
External links
Jellyfish Barge | Jellyfish Barge | [
"Chemistry",
"Engineering"
] | 185 | [
"Environmental mitigation",
"Architectural design",
"Environmental engineering",
"Design",
"Architecture"
] |
68,508,065 | https://en.wikipedia.org/wiki/Corner%20house | Corner Houses () are a type of building located at the junction of two or three roads.
Hong Kong
Corner houses are buildings located at junctions. In Hong Kong, buildings must meet certain specifications, which is why corner houses are so common on Hong Kong Island and Kowloon.
Corner houses originate from the Composite Buildings of Hong Kong. They were popularized in the 1950s and the 1960s. Most corner houses are fourth-generation tong lau, featuring rounded corners and lines.
Antonio Hermenegildo Basto currently holds the record for the most corner buildings designed in Hong Kong.
Locations
Hong Kong Island: Wan Chai, Causeway Bay, Sai Ying Pun, Shau Kei Wan
Kowloon: Sham Shui Po, Mong Kok, Tai Kok Tsui, To Kwa Wan, Cheung Sha Wan
Styles
Hanging signs in large facades.
Units in round corners are known as large units.
Round buildings are built in a Bauhaus style.
Types
Notable buildings
Hong Kong
14 Nam Cheong Street (Boundary Street and Nam Cheong Street)
May Wah Building (Wan Chai Road and Johnston Road
Mido Cafe (Temple Street and Public Square Street
New Lucky House (Nathan Road and Jordan Road)
Chung Wui Mansion (Wan Chai Road, Fleming Road, and Johnston Road)
Hing Wah Mansion (Babington Path, Park Road, St Stephen's Lane, and Oaklands Path)
Taiwan
Hayashi Department Store
United States
Flatiron Building (NYC)
UK
The Cornerhouse, Nottingham
Cornerhouse (Demolished)
See also
Tong lau
Composite Building
References
Further reading
External links
Piece of Hong Kong's History: Composite Buildings》
Buildings and structures by type | Corner house | [
"Engineering"
] | 336 | [
"Buildings and structures by type",
"Architecture"
] |
68,508,470 | https://en.wikipedia.org/wiki/Holmium%28III%29%20nitrate | Holmium (III) nitrate is an inorganic compound, a salt of holmium and nitric acid with the chemical formula Ho(NO3)3. The compound forms yellowish crystals, dissolves in water, also forms crystalline hydrates.
Synthesis
Anhydrous salt is obtained by the action of nitrogen dioxide on holmium(III) oxide:
Effect of nitrogen dioxide on metallic holmium:
Reaction of holmium hydroxide and nitric acid:
Physical properties
Holmium(III) nitrate forms yellowish crystals.
Forms a crystalline hydrate of the composition Ho(NO3)3•5H2O.
Soluble in water and ethanol.
Chemical properties
Hydrated holmitic nitrate thermally decomposes to form and decomposes to holmium oxide upon subsequent heating.
Application
The compound is used for the production of ceramics and glass.
Also used to produce metallic holmium and as a chemical reagent.
References
Holmium compounds
Nitrates | Holmium(III) nitrate | [
"Chemistry"
] | 190 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
51,382,351 | https://en.wikipedia.org/wiki/John%20Scott%20Lillie | Sir John Scott Lillie (1790 – 29 June 1868) was an Anglo-Irish decorated officer of the British Army and Portuguese Army who fought in the Peninsular War (1808–1814). He was a landowner, entrepreneur and inventor. He was Deputy Lieutenant of the County of Middlesex and Chairman of the Middlesex Quarter Sessions, a freemason, a radical politician and supporter of the great Irish statesman Daniel O'Connell. He was an early antivivisectionist and writer.
Background
John Lillie was the eldest son of Philip Lillie Esq., of Drumdoe Castle, County Roscommon and his wife Alicia, née Stafford. One source gives his birth date as 1789. He was heir to properties in Roscommon, Dublin and Bath. The family were said to be related to the Duke of Portland through his mother, Henrietta daughter of General John Scott of Fife, but the connection has yet to be established. Lillie's sister, Alicia, married as his second wife, Hugh Mill Bunbury of Guyana; their daughter became a noted Carmelite nun, while their youngest son, Charles Thomas fought in the Crimean War and was promoted Colonel. Having completed his education, Lillie sought his fortune in the British army. On his return to civilian life, having been thrice wounded in the Peninsular War, Lillie married Louisa Sutherland (b. 1791), daughter of Capt. Andrew Sutherland RN, Commissioner of Gibraltar and his wife Louisa Colebrooke, on 22 January 1820 at St George's, Hanover Square, Middlesex. The Lillies had a daughter and three sons, the youngest of whom, George Arthur Howard, became a Buddhist while out in India as an officer.
Military career
Lillie joined the 6th Warwickshire Regiment of Foot in 1807 as an ensign. The following year he embarked under Sir Brent Spencer in first expeditionary force to Portugal for service in Barbary, Cadiz and the Tagus. He joined the Lusitanian Legion of the Portuguese Army in the rank of captain, when still only 19 years old, under the watchful eye of Lieutenant-General William Carr Beresford, who raised the famous élite corps of light infantry, the Caçadores. Having taken part in engagements in defence of Portugal, Lillie was promoted lieutenant in 1810. He fought at the Battle of Bussaco and took part in the retreat to the Torres Vedras Lines. In 1812 at the Battle of Salamanca, he was reputed to have personally seized the Colours of the 116th French Line Regiment during the struggle for Arapiles. As commander of the 7th Caçadores, he led his troops into the Battle of the Pyrenees, Battle of Nivelle (1813), Battle of Orthez (1814) and finally, the Battle of Toulouse (1814), where he was gravely wounded (for the third time) and left for dead for 48 hours on the battlefield. He was awarded the Decoration of The Lily by the French. By the British he was awarded the Army Gold Cross, (later) he was honoured with the Military General Service Medal. In Wellington's army his progression was somewhat slow; he left the Peninsular War in the rank of major and in 1816 he was knighted by patent. In the 1831 Coronation Honours, he was made a Companion of the Bath. Also that year, Pedro of Portugal, promoted him to the rank of major general in the Portuguese Army. By the time he took formal retirement from the British Army, in 1855, he had attained the rank of lieutenant colonel with the commensurate pension. He left a record of his experiences in the war.
The entrepreneur and inventor
Still employed by the Army, but too disabled to serve and so on half pay, and recently married, he was received into the Prince of Wales (Freemasonry) Lodge (1923). On 'sick leave', Sir John sought to apply his energy and experience in London society. In 1822, he had bought 'the Hermitage', a grand villa once owned by the dramatist, Samuel Foote, with a fourteen-acre estate at North End, in the Parish of Fulham in the County of Middlesex. At that time, his new neighbours, the Edwardes and the Gunters were engaged in catching up with the canal boom and the burgeoning transportation revolution. Lillie, who was already a shareholder in the Hammersmith Bridge project, next became a major investor and actor in the Kensington Canal company, a scheme eventually bitterly opposed by Lord Holland. His strategy was to link the new Hammersmith river crossing with the village of Brompton, further downriver and closer to London. For that purpose, he donated some of his land in 1825 for a new stretch of public highway, joining Crown Lane and North End Lane to Counter's Creek (which was then being developed into the Kensington Canal), and the new canal bridge, built by Gunter.
To service the canal and wharf construction on land that are today's Langtry Place, Rickett Street and Roxby Place, he laid out two further stretches of unmade road either side of the new highway, named initially as the Richmond Road. The unmade roads were eventually called Richmond Gardens – later Empress Place – and Seagrave Road in Fulham. Around 1830, he also built the 'North End Brewery' and tavern to the South of the highway, together with a maltings to the north on the shorter stretch, initially managed by a Miss Goslin. To commemorate his development of the area and as its original freeholder, the 1835 tavern became known as the "Lillie Arms" (now renamed 'The Lillie Langtry', after the actress and mistress, among others, of the Prince Of Wales). The Fulham stretch of Richmond Road and the canal bridge were eventually renamed Lillie Road and Lillie Bridge respectively. The canal project was dogged by financial difficulties and was an ill-considered venture, whose time had passed. It eventually gave way to the railways, as first one track was laid along the canal, and in the 1860s that was filled in and a second rail track put down.
Sir John Lillie decided to leave North End in 1837 and moved with his family to Chelsea in the County of Middlesex, where he occupied 12, Cheyne Walk, a 'noble' Georgian mansion, to which he made major structural additions. From there, he moved to Kensington, probably in the late 1840s, where he remained to the end of his days.
Patent holder
During his lifetime, Sir John Scott Lillie took out upwards of 30 patents for all manner of improvements ranging from mechanisms for kneading dough, tilling fields, the chemical composition of stucco to propulsion engines on land and in the water. In 1836, he designed a power unit intended for propelling carriages and barges for which he was granted a patent. His military background influenced his design of the 'Lillie Rifle battery' an early form of machine gun.
Aware of the challenges for transport caused by the transformation of open fields into industrialised areas, Lillie applied himself to the creation of durable street paving. He designed a system using layers of wood and asphalt to make it weather-proof and was granted a patent.
In 1863, he was a founding member of the 'Institute of Inventors' and took the chair at the first annual general meeting, styled as 'General Sir John Scott Lillie'.
The politician and activist
While living in North End, Fulham, Lillie took up civic duties. He was swept up in the debate over parliamentary reform. In 1831, with the accession of a new king, he published a pamphlet about the redistribution of power in Parliament and the curbing of corruption in the electoral system. He was connected with the Whig politician, John Byng, 1st Earl of Strafford. In January 1835 Sir John Lillie stood for election as a burgess in the borough (constituency) of King's Lynn in the County of Norfolk, but despite loud support, he only managed to come third. His Irish roots and connections led Lillie to an active interest in Catholic emancipation. He was a friend and supporter of Daniel O'Connell. In his role as magistrate, Sir John intervened in 1840 in the matter of 'non-restraint of lunatics' at Hanwell Asylum, where it was reported that a lax approach was leading to self-harm by some patients. The matter was taken up in the press and in The Lancet.
Even in advanced old age, Lillie took a stance against the cruel treatment of animals in experiments, witness his letter to The Lancet in January 1861. He was still writing to the press on the power of musketry in 1866. Sir John Lillie was widowed in May 1860, when his wife Dame Louisa died at Dover. He then married widow Elisabeth Hannah Carew on 26 June 1862 at the British Embassy in Paris. She survived him. He himself died at his residence in Norfolk Terrace, Kensington on 29 June 1868 and was buried at Brompton Cemetery, very close to his earlier efforts on behalf of transport development in Fulham.
Awards and honours
The Most Honourable Order of the Bath, CB (Great Britain)
Army Gold Cross, (Great Britain), for Pyrenees, three clasps, Nivelle, Orthez, Toulouse
Military General Service, (Great Britain) seven clasps, for Battle of Roliça, Battle of Vimeiro, Bussaco, Battle of Badajoz (1812), Battle of Salamanca, Battle of Vitoria and Battle of Nive
Order of the Tower and Sword, Knight's breast Badge (Portugal)
Commander's Cross for Five Actions (Portugal): Pyrenees, Nivelle, Nive, Orthez and Toulouse
Campaign Cross for 4 Years, (Portugal)
Decoration of the Lily, (France)
Honour for rescuing a boy from drowning
In 1827 Lillie was on board a paquet in the Thames when it was involved in a collision with the works by the Tower. The boat seems to have disintegrated and sank immediately, leaving passengers and crew in the water. Other craft were quickly despatched to rescue the luckless victims and Lillie, being a strong swimmer, assisted a nine-year-old boy who had been with the party and could not swim. They were both picked and taken to safety. For this act of bravery, Sir John Scott Lillie was honoured by the Royal Humane Society in January 1827.
Bibliography
Lillie, J.S. and Mayne, William. (2014) The Loyal Lusitanian Legion during the Peninsular War: The Campaign of Wellington's Portuguese Troops, 1809–11 published by Leonaur Ltd.
Lillie, Sir John Scott. An Historical Sketch of the Origin and Progress of Parliamentary Corruption, and of the evils arising therefrom; in order to prove the ... necessity of parliamentary reform, London: Effingham Wilson, 1831, 86 pages.
* Polytechnisches Journal. 63. Band, Jahrgang 1837, N.F. 13. Band, Hefte 1-6 komplett. (= 18. Jahrgang, 1.-6. Heft ). Eine Zeitschrift zur Verbreitung gemeinnüziger Kenntnisse im Gebiete der Naturwissenschaft, der Chemie, der Pharmacie, der Mechanik, der Manufakturen, Fabriken, Künste, Gewerbe, der Handlung, der Haus- und Landwirthschaft etc. Herausgegeben von Johann Gottfried und Emil Maximilian Dingler.
Polytechnisches Journal. Hrsg. v. Johann Gottfried Dingler, Emil Maximilian Dingler und Julius Hermann Schultes:
Published by Stuttgart in der J. G. Cotta'schen Buchhandlung (1837)., 1837 (in German) - includes Lillie's invention.
Items named after Lillie
Lillie Road (Fulham)
Lillie Bridge, rebuilt by rail engineer, Sir John Fowler, 1st Baronet, 1866
Lillie Bridge Grounds, athletics and cricket grounds in Fulham where a number of records were achieved
Lillie Rec, The Lillie Road Recreation Ground, a park at the junction with the Fulham Palace Road
Lillie Bridge Railway Depot, 1872, engineering workshop for London Underground
Lillie Hall, Seagrave Road, Fulham - briefly a roller-skating venue, then taken over by Charles Rolls (later of Rolls-Royce company) in 1903 as a car showroom (demolished)
The Lillie Arms 1835 public house in Lillie Road, now renamed after 'Lillie Langtry' (opposite the Arts and crafts public house 'the Prince of Wales' destined for demolition in 2016)
The Lillie Rifle battery
Sir John Lillie Primary School (Fulham)
See also
Napoleonic Wars
Arthur Wellesley, 1st Duke of Wellington
History of the British canal system
Radicals (UK)
John Byng, 1st Earl of Strafford
The Westminster Review
References and notes
1790 births
1868 deaths
Military personnel from County Roscommon
Portuguese generals
British Army personnel of the French Revolutionary Wars
British Army commanders of the Napoleonic Wars
Companions of the Order of the Bath
Recipients of the Army Gold Cross
People of the Peninsular War
British inventors
Mechanical engineers
Transport pioneers
English justices of the peace
Deputy lieutenants of Middlesex
Whig (British political party) politicians
Knights Bachelor
British Freemasons
19th-century British military personnel
Burials at Brompton Cemetery
Royal Warwickshire Fusiliers officers
Irish officers in the British Army
19th-century Irish landowners
British anti-vivisectionists
Irish anti-vivisectionists | John Scott Lillie | [
"Engineering"
] | 2,740 | [
"Mechanical engineers",
"Mechanical engineering"
] |
51,384,538 | https://en.wikipedia.org/wiki/JOrgan | jOrgan is a Java-based MIDI processor. It is free software for complex transmitting and dynamical modifying of MIDI messages on their way between MIDI encoders and MIDI decoders, through an own MIDI Programming Language MPL. It can be used as Virtual Pipe Organ (virtual organ console). Runs on Microsoft Windows, Linux and macOS operating systems.
Features
Sources:
use a graphical user interface
customize your disposition conveniently. Set your MIDI inputs and basic settings
execute arbitrary commands
utilize Creative soundcards specific features
embed a Fluidsynth sampler in jOrgan
conveniently configure LinuxSampler
import elements from different sources
Use a virtual keyboard
connect to Midi devices on other computers with LAN devices
show disposition information on an LCD
store combinations in a memory
merge MIDI devices
record and share your performances
connect stop action magnets (SAM) driven stop tabs with your disposition
work with Soundfonts
work with MIDI tools and utilities
External references
MIDI
Java (programming language) | JOrgan | [
"Technology"
] | 198 | [
"Computing stubs",
"Software stubs"
] |
51,386,092 | https://en.wikipedia.org/wiki/Certifying%20algorithm | In theoretical computer science, a certifying algorithm is an algorithm that outputs, together with a solution to the problem it solves, a proof that the solution is correct. A certifying algorithm is said to be efficient if the combined runtime of the algorithm and a proof checker is slower by at most a constant factor than the best known non-certifying algorithm for the same problem.
The proof produced by a certifying algorithm should be in some sense simpler than the algorithm itself, for otherwise any algorithm could be considered certifying (with its output verified by running the same algorithm again). Sometimes this is formalized by requiring that a verification of the proof take less time than the original algorithm, while for other problems (in particular those for which the solution can be found in linear time) simplicity of the output proof is considered in a less formal sense. For instance, the validity of the output proof may be more apparent to human users than the correctness of the algorithm, or a checker for the proof may be more amenable to formal verification.
Implementations of certifying algorithms that also include a checker for the proof generated by the algorithm may be considered to be more reliable than non-certifying algorithms. For, whenever the algorithm is run, one of three things happens: it produces a correct output (the desired case), it detects a bug in the algorithm or its implication (undesired, but generally preferable to continuing without detecting the bug), or both the algorithm and the checker are faulty in a way that masks the bug and prevents it from being detected (undesired, but unlikely as it depends on the existence of two independent bugs).
Examples
Many examples of problems with checkable algorithms come from graph theory.
For instance, a classical algorithm for testing whether a graph is bipartite would simply output a Boolean value: true if the graph is bipartite, false otherwise. In contrast, a certifying algorithm might output a 2-coloring of the graph in the case that it is bipartite, or a cycle of odd length if it is not. Any graph is bipartite if and only if it can be 2-colored, and non-bipartite if and only if it contains an odd cycle. Both checking whether a 2-coloring is valid and checking whether a given odd-length sequence of vertices is a cycle may be performed more simply than testing bipartiteness.
Analogously, it is possible to test whether a given directed graph is acyclic by a certifying algorithm that outputs either a topological order or a directed cycle. It is possible to test whether an undirected graph is a chordal graph by a certifying algorithm that outputs either an elimination ordering (an ordering of all vertices such that, for every vertex, the neighbors that are later in the ordering form a clique) or a chordless cycle. And it is possible to test whether a graph is planar by a certifying algorithm that outputs either a planar embedding or a Kuratowski subgraph.
The extended Euclidean algorithm for the greatest common divisor of two integers and is certifying: it outputs three integers (the divisor), , and , such that . This equation can only be true of multiples of the greatest common divisor, so testing that is the greatest common divisor may be performed by checking that divides both and and that this equation is correct.
See also
Sanity check, a simple test of the correctness of an output or intermediate result that is not required to be a complete proof of correctness
References
Algorithms
Error detection and correction
Software testing | Certifying algorithm | [
"Mathematics",
"Engineering"
] | 752 | [
"Software testing",
"Reliability engineering",
"Algorithms",
"Mathematical logic",
"Applied mathematics",
"Error detection and correction",
"Software engineering"
] |
51,386,599 | https://en.wikipedia.org/wiki/Library%20linked%20data | Library linked data (LLD) is the use of linked data standards by libraries. These standards are usually applied to bibliographic and authority data sets, with the hope of decreasing redundant cataloging work; and increasing visibility of library resources and interoperability with non-library systems.
Use cases
In 2010, Byrne and Goddard have written that the "killer [library linked data] example isn't out there yet," and warned that implementation work will be hampered if clear use cases don't exist.
Many groups have examined this issue, including the W3C Library Linked Data Incubator Group, the Bibliographic Framework Initiative, and the LD4L project.
Conferences
The Hochschulbibliothekszentrum des Landes Nordrhein-Westfalen and the German National Library of Economics sponsor the annual international Semantic Web in Libraries (SWIB) conference
See also
BIBFRAME
Resource Description and Access and RDA vocabularies
Universal Bibliographic Control
References
Library cataloging and classification
Metadata
Semantic Web
Open data | Library linked data | [
"Technology"
] | 216 | [
"Metadata",
"Data"
] |
51,387,412 | https://en.wikipedia.org/wiki/Zonal%20wavenumber | In meteorological applications, a zonal wavenumber or hemispheric wavenumber is the dimensionless number of wavelengths fitting within a full circle around the globe at a given latitude:
where λ is the wavelength, r = 6378 km is the Earth's radius, and is the latitude.
Zonal wavenumbers are typically counted on the upper level (say 500-millibar) geopotential maps by identifying troughs and ridges of the waves. Wavenumber 1 has one trough and one ridge, i.e. one wavelength fits 2π = 360°. Wavenumber 2 has two ridges and two troughs around 360°.
Wavenumber 0 corresponds to zonal (symmetric) flow. Wavenumbers 1–3 are called long waves and are often synonymous in meteorological literature with the mid-latitude planetary Rossby waves, while wavenumbers 4–10 are often referred to as "synoptic" waves. In the Northern Hemisphere, wavenumbers 1 and 2 are important for the time-mean circulation due to topography (Tibetan Plateau and Rocky Mountains), whereas in the Southern Hemisphere, tropical convection is responsible for the presence of mainly zonal wavenumber 3.
See also
Wavenumber
References
Atmospheric dynamics
Rates | Zonal wavenumber | [
"Chemistry"
] | 256 | [
"Atmospheric dynamics",
"Fluid dynamics"
] |
51,388,264 | https://en.wikipedia.org/wiki/Territorial%20Environmental%20Information%20System%20of%20the%20Colombian%20Amazon | The Territorial Environmental Information System of the Colombian Amazon SIAT-AC () has been defined as a process in which a set of institutions sets up agreements and common goals for the environmental information management of the Colombian Amazon. The agreements cover concepts, organization, data infrastructure, methodologies, protocols, and technological issues such as information networks, telecommunications, and access, organized by a network of individuals and entities to provide data and information products for regional decision makers to achieve sustainable development.
Purposes
SIAT-AC contributions range from environmental information management to knowledge generation, decision-making, and social participation for the sustainable development and management of the Colombian Amazon, by:
Helping to make the processes of occupying the Amazon territory environmentally and socially sustainable.
Organizing and properly distributing environmental information to support national and regional processes that affect the Colombian Amazon. These processes include: policy design, research, development, education, production and extraction of natural resources, environmental monitoring, environmental management, and construction of a regional vision.
Designing and establishing a network of institutions and individuals operating under agreements regarding environmental information management.
Promoting the assurance of permanent environmental data of the CA managed by SINA's entities.
Facilitating access to environmental information on the Colombian Amazon for all audiences.
Adapting, adopting or developing standards, protocols, technology solutions and processes to capture, generate, process, move, disclose and manage the generated information on the Colombian Amazon. Responding to the demand for environmental information on the Colombian Amazon.
References
Citations
Sources
Conceptual model - Territorial Environmental Information System of the Colombian Amazon SIAT-AC 2007
External links
SIAT-AC
Sinchi Amazonic Institute of Scientific Research (SINCHI)
Amazon basin
Information management
Environmental monitoring
Society of Colombia | Territorial Environmental Information System of the Colombian Amazon | [
"Technology"
] | 336 | [
"Information systems",
"Information management"
] |
51,388,487 | https://en.wikipedia.org/wiki/Traffic%20Electronic%20Control%20System%20%28Turkey%29 | Traffic Electronic Control System, locally known as TEDES, an acronym for "Trafik Elektronik DEnetleme Sistemi", is a monitoring and imaging system for traffic law enforcement used on some streets and highways in Turkey to ensure road safety.
TEDES equipment is an integrated speed camera, red light camera and automatic number plate recognition device. Mounted beside or over a road, it detects violations of traffic regulation such as speeding and red light running. Other capabilities of TEDES are monitoring of driving on emergency stopping lane and parking violations. The system is linked to an automated ticketing service.
Implementation
The legal infrastructure for TEDES was enacted on December 9, 2015, as a supplement to the Highways Traffic Law (Act #2918). For the implementation, municipalities are made responsible. TEDES measures are executed by the Turkish National Police in the name of the Ministry of the Interior and the Ministry of Finance. Municipalities receive 30% of the monthly revenues from the TEDES-related traffic fines for their expenses on installation and maintenance.
TEDES is an integral part of the public area CCTV system (KGYS "Kent Güvenlik Yönetim Sistemi", literally: "City Security Management System") when this is already installed in the related city.
Pilot experiment with TEDES started in Çerkezköy, Tekirdağ Province in November 2013. Other cities in the country implemented the system later with Ordu being the first in November 2015.
Ticketing
The information collected by TEDES is converted to an administrative penalty decision. A traffic ticket constituting a fine assessed against the owner of the vehicle is sent per mail to the owner's address accompanied by an image of the vehicle taken during the violation, which shows the vehicle registration plate. The fine for speeding is categorized in two as exceeding the speed limit between 10% and 30%, and more than 30%. Forced red light violation in order to enable emergency vehicles with right-of-way, such as ambulances, fire engines and police cars, pass through is not charged. According to a court order, traffic law violations of a vehicle assessed by TEDES within five minutes can be charged once only.
Arrival of the ticket per mail can take five to fifteen days. The existence of a ticket can be questioned online at the government's website by giving details of the related traffic registration certificate. The fine can be paid online at the website of the government's revenue administration.
Controversy
The income generated by ticketing the drivers is also shared with the municipalities where the system is commissioned. This generates incentive for municipalities to install TEDES on most abusive parts of the roads to increase the number of traffic violation tickets.
Road safety
It was reported that the number of traffic collisions at the TEDES-monitored intersections and fast lanes in Gaziantep declined by about 40% within two months of the implementation of TEDES in mid-April 2016. The average daily traffic law violation decreased from 3,500 in April 2016, to 1,500 in May and 1,200 in June of the same year. About 70% of the violations were speeding related.
References
External links
TEDES (Trafik Elektronik Denetleme Sistemi) website
2015 establishments in Turkey
Road safety in Turkey
Automatic number plate recognition
Law enforcement in Turkey
Road speed limit
Road traffic management
Traffic enforcement cameras | Traffic Electronic Control System (Turkey) | [
"Technology",
"Engineering"
] | 681 | [
"Measuring instruments",
"Traffic enforcement cameras"
] |
51,388,505 | https://en.wikipedia.org/wiki/Community%20respiration | Community respiration (CR) refers to the total amount of carbon-dioxide that is produced by individuals organisms in a given
community, originating from the cellular respiration of organic material. CR is an important ecological index as it dictates the amount
of production for the higher trophic levels and influence biogeochemical cycles.
CR is often used as a proxy for the biological activity of the microbial community.
Overview
The process of cellular respiration is foundational to the ecological index, community respiration (CR). Cellular respiration can be used to explain relationships between heterotrophic organisms and the autotrophic ones they consume. The process of cellular respiration consists of a series of metabolic reactions using biological material produced by autotrophic organisms, such as oxygen () and glucose (C6H12O6) to turn its chemical energy into adenosine triphosphate (ATP) which can then be used in other metabolic reactions to power the organism, creating carbon dioxide () and water () as a by-product. The overall process of cellular respiration can be summarized with, C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.
The ATP created during cellular respiration is absolutely necessary for a living being to function as it is the 'Energy currency" of the cell and none of the other metabolic functions could be sustained without it. The process of cellular respiration is an essential component of the Carbon Cycle, which tracks the recycling of carbon through the earth and atmosphere in various compounds such as: CO2 ,H2CO3, HCO3− ,C6H12O6 , CH4 to name a few.
The concentration of carbon dioxide in a given area can act as a proxy indicator for metabolic function of an individual, or individuals in that area. Since the process of cellular respiration consumes oxygen and produces carbon dioxide the amount of carbon dioxide can be used to infer the amount of oxygen used in the environment specifically for metabolic requirements. Since cellular respiration has been studied in depth across all taxa, research surrounding the process can have many further biological implications. Community respiration is a good example, but our data is low. More research needs to be done to further elucidate its usefulness as a ecological index.
Significance
Community respiration (CR) is an important ecological index used primarily in marine and freshwater aquatic ecosystems and is often tightly coupled with Gross Primary Production (GPP). Since CR is a measure of the total amount of CO2 that is produced by all the organisms in a community solely from cellular respiration it can be a useful tool in finding the amount of O2 which is used directly to fuel Cellular respiration. The elements can be isolated by using the Electron Transport System (ETS) as a respiratory index and measuring that, which would indicate the rate of cellular respiration. CR can be used in conjunction with other ecological indexes such as Dissolved oxygen concentration (DO), Gross Primary Production (GPP), Nutrient availability, Light availability and Temperature. Using CR as a measure of the total amount of Carbon dioxide that is produced by a community is useful to aid in our understanding of an ecosystems biogeochemical cycles. CR is also useful in understanding an ecosystems net balance and trophic levels
Using Dissolved oxygen as another ecological index to compare it to is one of the more useful applications of community respiration. Because global warming is so significant, it is of great concern to scientists. As ocean temperatures rise, the levels of dissolved oxygen drop from the subsequent oxygen loss by warmer water. GPP and CR will differ significantly because of their sensitivity to global warming.
See also
Microbial ecology
References
Ecology | Community respiration | [
"Biology"
] | 754 | [
"Ecology"
] |
51,388,622 | https://en.wikipedia.org/wiki/Hilscher%20netx%20network%20controller | The netX network controller family (based on ASICs), developed by Hilscher Gesellschaft für Systemautomation mbH, is a solution for implementing all proven Fieldbus and Real-Time Ethernet systems. It was the first Multi-Protocol ASIC which combines Real-Time-Ethernet and Fieldbus System in one solution. The Multiprotocol functionality is done over a flexible cpu sub system called XC. Through exchanging some microcode the XC is able to realize beside others a PROFINET IRT Switch, EtherCAT Slave, Ethernet Powerlink HUB, PROFIBUS, CAN bus, CC-Link Industrial Networks Interface.
The Hilscher netX family
Multiplex Matrix IOs (MMIO)
The Multiplex Matrix is a set of PINs which could be configured freely with peripheral functions. Options are CAN, UART, SPI, I2C, GPIOs**, PIOs and SYNC Trigger.
GPIOs
The GPIOs from Hilscher are able to generate Interrupts, could count level or flags, or could be connected to a timer unit to auto generate a PWM. The Resolution of the PWM is normally 10ns. In some netX ASICS is a dedicated Motion unit with a resolution if 1ns is available.
References
External links
Hilscher homepage
ASICS
Industrial automation
Computer networks
Industrial Ethernet
Industrial computing
CAN bus | Hilscher netx network controller | [
"Technology",
"Engineering"
] | 280 | [
"Industrial computing",
"CAN bus",
"Automation",
"Industrial engineering",
"Industrial Ethernet",
"Industrial automation"
] |
51,388,795 | https://en.wikipedia.org/wiki/Phycotechnology | Phycotechnology refers to the technological applications of algae, both microalgae and macroalgae.
Uses
Sewage reclamation
Currently micro-algae are being exploited for environmental protection as the species of Chlorella, Chlamydomonas, and Scenedesmus carry out selective uptake, accumulation and biodegradation of pollutants and thus help in remediation. They are used in biological reclamation of sewage since they can immobilize heavy metals from aquatic systems.
Insecticide
Microalgae can be used as biocontrol agents like 'Insect' a commercial bio-insecticide sold in USA, prepared from the dead biomass of diatom frustules.
Fuel creation
Algae are an excellent feed stock for green fuel as they are used for the production of biodiesel, bioethanol, biogasoline, biomethanol, biobutanol, and recently biohydrogen.
Healthcare
Microalgae are of significant use in healthcare. Chlorellin from the green microalga Chlorella is an effective antibiotic against Gram positive and Gram-negative bacteria.
Other uses
Algae is extremely useful in various fields. An example for natural phycotechnology is the converting of atmospheric nitrogen into bioaccessible nitrogenous compounds by diazotrophic cyanobacteria (blue-green algae). Species of cyanobacteria like Nostoc, Arthrospira (Spirulina) and Aphanizomenon are used as food and feed due to their easy digestibility and nutrient content. Species of Dunaliella provide products like glycerol, carotenoids, and proteins. Algal-produced proteins can be biofactories for the production of therapeutic substances.
References
Algae
Biotechnology
Agricultural technology
Algaculture | Phycotechnology | [
"Biology"
] | 373 | [
"Algaculture",
"Algae",
"nan",
"Biotechnology"
] |
51,389,390 | https://en.wikipedia.org/wiki/Antonia%20Ferr%C3%ADn%20Moreiras | Antonia Ferrín Moreiras (Ourense, 13 May 1914 – Santiago de Compostela, 6 August 2009) was a mathematician, professor and the first female Galician astronomer. Her main contributions to astronomy were works on stellar occultations by the moon, measures of double stars and astrometric measurements, as well as the determination of the passage of stars through two verticals. She accomplished all of this while she was working at the Observatory of the University of Santiago de Compostela (USC).
Before the Spanish Civil War, she obtained degrees in chemistry and pharmacy from the USC, earned her teaching diploma and studied Exact Sciences, the name for mathematics, for two years. She obtained her degree in mathematics in the Complutense University of Madrid some years later.
In 1963 she became the first Spanish woman to defend a thesis that addressed the issue of astronomy: Observaciones de pasos por dos verticales (in English, Observations of passages of stars through two verticals). This thesis was also the first defended in the Faculty of Mathematics of the USC.
Economic hardship forced her to study and work at the same time, but she earned scholarships that helped her reach her academic goals.
Biography
Early years
Antonia Ferrín Moreiras was born in Ourense on 13 May 1914, and was the third of four daughters. Contrary to the conventions of the time, and despite the limited economic resources of the family, her father, a mathematics teacher, wanted all his daughtersAntonia, Celsa, María and Pastora, to have access to higher-level studies, so the family moved to Santiago de Compostela in 1920.
Ferrín started school when she was seven years old and at only nine years old, she was ready to start high school. She did the Scientific Bachillerato, which is the stage of education for people over the age of 16 in Spain. After that, she studied the University Bachillerato, since admission to the university required the completion of this education stage, with twelve other girls.
Higher education and professional career
Ferrin started her higher education studies in the Faculty of Sciences of the USC, at a time when chemistry was the only major offered. Even though her father worked in the Faculty of Pharmacy, his income was not enough, so she obtained free tuition and scholarships. With such financial support, she could earn a degree in chemistry and the title of Schoolteacher in 1935.
She started working immediately after she graduated, but her first jobs were not paid. From 1934 to 1936, Ferrín worked as training assistant teacher of physics and mathematics in the Faculty of Sciences of the USC and as temporary assistant teacher in the Department of Science of the high school Arcebispo Xelmírez in Santiago de Compostela. At the same time, she was pursuing a pharmacy degree and the only two courses of Exact Sciences that the USC offered. In 1937, she started working as mathematics teacher in the orphan girls' school Nuestra Señora de los Remedios, a position she held until 1948.
In 1937, after the outbreak of the Spanish Civil War, she was sanctioned because of her political convictions, and an anonymous complaint lead to the opening of her file. As a result, she was removed from her duties as university teacher along with 45 other teachers. In 1940, however, she got her case reviewed, the sentence was revoked and she could teach again. After her removal, she restarted teaching at the university and sometimes she gave lessons in the girls' school until 1961.
During the academic year 1939–1940, Ferrin completed the prerequisite courses for the pharmacy degree. It was during this time that she met Ramón María Aller, the founder and director of the Astronomical Observatory of the USC, and the person who made it possible for her to become the first female Galician astronomer. In that observatory, Ferrín started to use the passage instrument and the refracting telescope, which allowed her to visualize the concealment of stars by the moon, the passage of stars through two verticals, or micrometric measurements of double stars. The results of these investigations were published in the Spanish magazine of astronomy, Urania. Ferrín recalled anecdotally that it was really cold while she was doing her research in the observatory. She never wore trousers because, according to her, it was a piece of clothing that "was not considered feminine and only the more daring movie actresses wore them on the big screen."
In 1950, she received a scholarship from the Spanish National Research Council to conduct research in the Astronomical Observatory of Santiago. This scholarship became a contract of research assistantship two years later. In the same year, she obtained a degree in mathematics from the Complutense University of Madrid, even though she was a guest student for the last three courses of the degree.
In 1953, she passed the civil service examinations for professor of mathematics in the Escuela de Magisterio of Santander. However, two years later, she transferred to the girls' school Isabel la Católica of Santiago.
From 1954 until 1956 she studied to earn a doctorate in astronomy in Madrid. In the meantime, she helped professor Vidal Abascal to create the degree in mathematics in the Faculty of Sciences of the USC, a feat accomplished in 1957. Ferrín became the first female professor of this faculty. During this time, she continued her research under the direction of Ramón María Aller.
The thesis that she defended in 1963 with the help of Aller, even though he was 80 years old, was probably her greatest accomplishment not only because it was the first read in the Faculty of Mathematics of the USC, but also the first one defended by a woman addressing the issue of astronomy in Spain. In 1963, she was appointed as full-time professor of mathematics in the Escuela de Magisterio Santa María in Madrid and she also worked as professor of mathematics in the degree of medicine for two years. In addition, she taught astronomy and celestial mechanics, she served in management, and sat on the selection boards. She also participated in the first international meetings of mathematics that were carried out in Spain.
However, in spite of her great professional career, being a woman sometimes stood in the way of her aspirations. For example, when Aller got sick in 1964, a substitute was needed so that Aller's chair of astronomy in the observatory could continue. Even though she applied for the public examination, she was excluded. She was considered as an applicant following a complaint, but the chair was declared void and the observatory deteriorated.
Ferrín retired in 1984.
Honors
On 24 May 2008, she was proclaimed as the patroness of the fiftieth anniversary of the Faculty of Mathematics of the USC.
Eponymous
Lecture room of the Faculty of Mathematics of the USC.
Award for the creation of education materials and resources with gender perspective in the University of Vigo.
References
2009 deaths
1914 births
20th-century Spanish mathematicians
20th-century Spanish astronomers
Women mathematicians
Women astronomers
Scientists from Galicia (Spain)
Complutense University of Madrid alumni | Antonia Ferrín Moreiras | [
"Astronomy"
] | 1,435 | [
"Women astronomers",
"Astronomers"
] |
51,389,757 | https://en.wikipedia.org/wiki/Lake%20Nyos%20disaster | On 21 August 1986, a limnic eruption at Lake Nyos in northwestern Cameroon killed 1,746 people and 3,500 livestock.
The eruption triggered the sudden release of about 100,000–300,000 tons of carbon dioxide (CO2). The gas cloud initially rose at nearly and then, being heavier than air, descended onto nearby villages, suffocating people and livestock within of the lake.
A degassing system has since been installed at the lake, with the aim of reducing the concentration of in the waters and therefore the risk of further eruptions. Along with the Lake Monoun disaster two years earlier, it is one of only two recorded limnic eruptions in history.
Eruption and gas release
What triggered the catastrophic outgassing is not known. Most geologists suspect a landslide, but some believe that a small volcanic eruption may have occurred on the bed of the lake. A third possibility is that cool rainwater falling on one side of the lake triggered the overturn. Others still believe there was a small earthquake, but because witnesses did not report feeling any tremors on the morning of the disaster, this hypothesis is unlikely. The event resulted in the supersaturated deep water rapidly mixing with the upper layers of the lake, where the reduced pressure allowed the stored to effervesce out of solution.
It is believed that about of gas was released. The normally blue waters of the lake turned a deep red after the outgassing, due to iron-rich water from the deep rising to the surface and being oxidised by the air. The level of the lake dropped by about a metre and trees near the lake were knocked down.
Scientists concluded from evidence that a column of water and foam formed at the surface of the lake, spawning a wave of at least that swept the shore on one side.
Since carbon dioxide is 1.5 times the density of air, the cloud hugged the ground and moved down the valleys, where there were various villages. The mass was about thick, and travelled downward at . For roughly , the gas cloud was concentrated enough to suffocate many people in their sleep in the villages of Nyos, Kam, Cha, and Subum. About 4,000 inhabitants fled the area, and many of these developed respiratory problems, lesions, and paralysis as a result of the gas cloud.
It is a possibility that other volcanic gases were released along with the , as some survivors reported a smell of gunpowder or rotten eggs, which indicates that sulfur dioxide and hydrogen sulfide were present at concentrations above their odour thresholds. However, was the only gas detected in samples of lake water, suggesting that this was the predominant gas released and as such the main cause of the incident.
Effects on survivors
Reporters in the area described the scene as "looking like the aftermath of a neutron bomb." One survivor, Joseph Nkwain from Subum, described himself when he awoke after the gases had struck:Following the eruption, many survivors were treated at the main hospital in Yaoundé, the country's capital. It was believed that many of the victims had been poisoned by sulphur-based gases. Poisoning by these gases would lead to burning pains in the eyes and nose, coughing and signs of asphyxiation similar to being strangled.
Interviews with survivors and pathologic studies indicated that victims rapidly lost consciousness and that death was caused by asphyxiation. At nonlethal levels, can produce sensory hallucinations, such that many people exposed to report the odor of sulfuric compounds when none are present. Skin lesions found on survivors represent pressure sores, and in a few cases exposure to a heat source, but there is no evidence of chemical burns or of flash burns from exposure to hot gases.
De-gassing
The scale of the disaster led to much study on how a recurrence could be prevented. Several researchers proposed the installation of degassing columns from rafts in the middle of the lake. The principle is to slowly vent the by lifting heavily saturated water from the bottom of the lake through a pipe, initially by using a pump, but only until the release of gas inside the pipe naturally lifts the column of effervescing water, making the process self-sustaining.
Starting from 1995, feasibility studies were successfully conducted, and the first permanent degassing tube was installed at Lake Nyos in 2001. Two additional pipes were installed in 2011. In 2019 it was determined that the degassing had reached an essentially steady state and that a single one of the installed pipes would be able to self-sustain the degassing process into the future, indefinitely maintaining the at a safe level, without any need for external power.
Similar danger suspected at Lake Kivu
Following the Lake Nyos disaster, scientists investigated other African lakes to see if a similar phenomenon could happen elsewhere. In 2005, Lake Kivu in the Democratic Republic of the Congo, 2,000 times larger than Lake Nyos, was also found to be supersaturated, and geologists found evidence that outgassing events around the lake happened about every thousand years.
However, a study undertaken in 2018 and released in 2020 found flaws in the 2005 study, including a possible bias in the conversion of concentrations to partial pressures, to an overestimation of concentrations, or to a problem of calibration of sensors at high pressure. The 2020 study found that when these errors were accounted for, the risk of a gas eruption at Lake Kivu did not seem to be increasing over time.
See also
Lake Monoun
List of natural disasters by death toll
References
External links
Google Earth view of the area around Lake Nyos
1986 natural disasters
1986 in Cameroon
Natural disasters in Cameroon
20th-century volcanic events
Gas explosions
August 1986 events in Africa
Volcanic tsunamis
1986 disasters in Africa | Lake Nyos disaster | [
"Chemistry"
] | 1,172 | [
"Natural gas safety",
"Gas explosions"
] |
51,389,836 | https://en.wikipedia.org/wiki/Desulfohalobium | Desulfohalobium is a Gram negative, anaerobic, sulfate-reducing, moderately halophilic and rod-shaped bacterial genus from the family of Desulfovibrionaceae.
See also
List of bacterial orders
List of bacteria genera
References
Further reading
Bacteria genera
Halophiles
Desulfovibrionales | Desulfohalobium | [
"Biology"
] | 66 | [
"Bacteria stubs",
"Bacteria"
] |
51,390,952 | https://en.wikipedia.org/wiki/Time%20in%20Tunisia | Time in Tunisia is given by a single time zone, officially denoted as Central European Time (CET; UTC+01:00). Tunisia adopted WAT on 12 April 1911, and does not observe daylight saving time, though previously it has.
Daylight saving time
Tunisia previously observed daylight saving time – advancing the clock forward one hour – between 1939 and 1945, 1977 and 1978, 1988 and 1990, and finally between 2006 and 2008.
IANA time zone database
In the IANA time zone database, Tunisia is given one zone in the file zone.tab – Africa/Tunis. "TN" refers to the country's ISO 3166-1 alpha-2 country code. Data for Tunisia directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
List of time zones by country
List of UTC time offsets
References
External links
Current time in Tunisia at Time.is
Time in Tunisia at TimeAndDate.com
Time by country
Geography of Tunisia
Time in Africa | Time in Tunisia | [
"Physics"
] | 209 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
51,392,611 | https://en.wikipedia.org/wiki/Marco%20Antonio%20Cuevas | Marco Antonio Cuevas Cruz (November 18, 1933 – February 2, 2009) son of Angel Rafael Cuevas del Cid and Maria Soledad Cruz Sierra. He had three brothers: Marta Cuevas del León, Rafael Cuevas del Cid and José Rodolfo Cuevas Cruz. He studied at Colégio de Infantes and the Liceo Guatemala, where he graduated as valedictorian. In 1955 he represented Guatemala in the second Pan American Games, having won the gold medal in rowing competitions, along with his team.
Born Antigua Guatemala, he studied civil engineering at the University of San Carlos of Guatemala (USAC). At that time, he worked at the General Directorate of Roads and the Institute of Development of Municipal Works (INFOM), where he met Engineer Raul Aguilar Batres, great precursor of planning in Guatemala, who urged him to undertake graduate studies in urban planning. He attended the program led by Yale University, based in Lima, Peru, from 1960 to 1963. Upon his return to Guatemala in 1965, he continued to work in the INFOM as the first graduate in Urban Planning in the history of Guatemala. He then introduced urban planning methods that were used to make more effective the execution of public works and created the Center for Urban and Regional Studies (CEUR) USAC, where he taught until 1978, when he was appointed as the first manager of the Guatemalan Railroads, after its nationalization during the government of Julio César Méndez Montenegro.
Between 1970 and 1994, with a team of professionals, developed several master plans for the cities of Rio de Janeiro, Brazil, Santa Cruz, Bolivia, San Pedro Sula, Honduras, Nairobi, Kenya and Guatemala (1972–2000). In 1986, as part of the activities of the Centre for Political Studies (CEDEP), he participated in the drafting of the new Constitution of Guatemala and, in the same year, was in charge of the formation of the new electoral system in the first election of a civilian government during the internal armed conflict of Guatemala (1959–1996). In the 1960s he served as a member of the Board of the Faculty of Engineering of the USAC. From 1990 to 2007 he led the development of several low-cost housing projects, having introduced innovative concepts for planning and financing. At the same time, he developed the first plan for territorial ordering, at the national level, in Guatemala. He died on February 2, 2009.
The National Library of Guatemala inaugurated in 2016 a special room that houses the private collection of books on urban planning that belonged to Marco Antonio Cuevas.
See also
Raul Aguilar Batres
Bibliography
People from Guatemala City
Civil engineers
1933 births
2009 deaths
Guatemalan engineers | Marco Antonio Cuevas | [
"Engineering"
] | 544 | [
"Civil engineering",
"Civil engineers"
] |
41,340,447 | https://en.wikipedia.org/wiki/Spectator%20ligand | In coordination chemistry, a spectator ligand is a ligand that does not participate in chemical reactions of the complex. Instead, spectator ligands (vs "actor ligands") occupy coordination sites. Spectator ligands tend to be of polydentate, such that the M-spectator ensemble is inert kinetically. Although they do not participate in reactions of the metal, spectator ligands influence the reactivity of the metal center to which they are bound. These ligands are sometimes referred to as ancillary ligands.
Several different classes of ligand exist that can be considered spectator ligands. A few examples include trispyrazolylborates (Tp), cyclopentadienyl ligands (Cp), and many chelating diphosphines such as 1,2-bis(diphenylphosphino)ethane ligands (dppe). Varying the substituents on the spectator ligands greatly influences the solubility, stability, electronic, and steric properties of the metal complex. In the area of platinum-based antineoplastic agents, spectator (and nonspectator) ligands greatly affect efficacy.
References
Coordination chemistry
Organometallic chemistry | Spectator ligand | [
"Chemistry"
] | 248 | [
"Organometallic chemistry",
"Coordination chemistry"
] |
41,340,805 | https://en.wikipedia.org/wiki/KryoFlux | KryoFlux is a hardware and software solution for preserving software on floppy disks. It was developed by the Software Preservation Society.
Overview
KryoFlux consists of a small hardware device, which is a software-programmable FDC system that runs on small ARM-based devices that connects to a floppy disk drive and a host PC over USB, and software for accessing the device. KryoFlux reads "flux transitions" from floppy disks at a very fine resolution. It can also read disks originally written with different bit cell widths and drive speeds, with a normal fixed-speed drive. The software is available for Microsoft Windows, Mac OS and Linux. The KryoFlux controller plugs into a standard USB port, and allows normal PC floppy disk drives to be plugged into it.
Because the device operates on data bits at the lowest possible level with very precise timing resolution, it allows modern PCs to read, decode and write floppy disks that use practically any data format or method of copy protection to aid in digital preservation. It has been tested successfully with many generations of floppy disk drive including 8", 5.25", 3.5" and 3" mechanisms, and dozens of disk formats including numerous schemes originally designed to prevent software piracy, allowing the preservation (typically to an image file stored on hard disk or other modern media) of programs and data that will inevitably succumb to data degradation as the original physical media deteriorates and becomes unreadable over time. The image files produced may be rewritten to fresh disk media or, more commonly, used with software emulations of the original systems.
When reading old disks (especially those stored in non-climate controlled environments for long periods) there are a number of problems that can arise, including weakening of the magnetic field storing the data, deterioration of the binder holding the metal particles to the plastic disk surface, friction issues preventing the disk rotating freely in its outer protective sleeve, and issues caused by physical misalignment of the drive that originally wrote the disk or the one being used to read it. Users have detailed various techniques to aid in the recovery of data stored on such marginal disks.
References
External links
Digital preservation
Floppy disk computer storage | KryoFlux | [
"Technology"
] | 451 | [
"Computing stubs",
"Software stubs"
] |
41,341,065 | https://en.wikipedia.org/wiki/Methylphosphonic%20acid | Methylphosphonic acid is an organophosphorus compound with the chemical formula CH3P(O)(OH)2. The phosphorus center is tetrahedral and is bonded to a methyl group, two OH groups and an oxygen. Methylphosphonic acid is a white, non-volatile solid that is poorly soluble in organic solvent but soluble in water and common alcohols.
Preparation
Methylphosphonic acid can be prepared from triethylphosphite by first using a Michaelis-Arbuzov reaction to generate the phosphorus(V) centre:
CH3Cl + P(OC2H5)3 → CH3PO(OC2H5)2 + C2H5Cl
The resulting dialkylphosphonate is then treated with chlorotrimethylsilane before hydrolysis of the siloxyphosphonate to generate the desired product.
CH3PO(OC2H5)2 + 2 Me3SiCl → CH3PO(OSiMe3)2 + 2 C2H5Cl
CH3PO(OSiMe3)2 + 2H2O → CH3PO(OH)2 + 2 HOSiMe3
The reaction pathway proceeds via the siloxyphosphonate intermediate due to the difficulty in directly hydrolysing dialkylphosphonates. Katritzky and co-workers published a one-pot synthesis of methylphosphonic acid in 1989.
References
Phosphonic acids
Organic compounds with 1 carbon atom | Methylphosphonic acid | [
"Chemistry"
] | 312 | [
"Organic compounds",
"Organic compounds with 1 carbon atom"
] |
41,341,108 | https://en.wikipedia.org/wiki/Hakk%C4%B1%20%C3%96gelman | Hakkı Boran Ögelman (July 8, 1940 – September 4, 2011) was a Turkish physicist and astrophysicist. He was an expert on gamma ray astronomy, the physics of neutron stars, and solar energy and worked on several key topics in modern astrophysics. He made many contributions to high energy astrophysics. In his early professional career he engaged in the SAS-II Small Gamma Ray Astronomy Satellite experiment development, data analysis, and first detection and imaging of our universe in gamma rays with his NASA colleagues, as well as in other fields of physics. His main interests in the field of astrophysics were the study of gamma ray astronomy and compact objects such as neutron stars and pulsars. Ögelman worked at NASA's Goddard Space Flight Center, Middle East Technical University (METU) in Ankara, Turkey, Çukurova University in Adana, Turkey, Max Planck Institute (MPI) at Garching, Germany and the University of Wisconsin.
First years
Hakkı Ögelman was born in Ankara, Turkey, on July 8, 1940. His father was Salehettin Ögelman, a lawyer, and his mother was Vedya Özlem Ögelman, a school teacher.
Education
Hakkı Ögelman attended Robert College in Istanbul, receiving his baccalaureate in 1957, then went to the United States to further his education. He received his B.A. in physics from DePauw University in June 1960 and his M.Sc. and Ph.D. from Cornell University in 1963 and 1966, respectively. He married a DePauw classmate, Ivy White.
Early career
After his 1966 graduation from Cornell, Ögelman did one year of postdoctoral research at the University of Sydney, Australia. He then worked at Goddard Space Flight Center from September 1967 to January 1970 as National Academy of Sciences Research Associate.
Turkey and METU
In February 1970 Ögelman decided to return to Turkey, so that he could contribute his experimental research and teaching capabilities to his country. He was hired as an associate professor in the Middle East Technical University (METU) Physics Department, and was appointed department chairman that same year. He started an experimental High Energy Astrophysics group specializing in gamma ray astronomy—at the time, a fledgling new field—and took on graduate students for the group's M.Sc. and Ph.D. programs. Ögelman also started a new solar energy group to train graduate students to address Turkey's energy needs. Additionally, he worked with the METU's Carbon-14 Dating Group, led by Yeter Güksü, a physics department colleague who would later become his second wife.
During Ögelman's time at METU, his astrophysics group's major projects used data of NASA's SAS-II (Second Small Astronomy Satellite) gamma ray telescope. With this group and his former NASA colleagues, Ögelman co-authored several critical papers on gamma ray astronomy published using the SAS II data. Their work covered the premiere satellite based detection of gamma rays from celestial objects, the observation of galactic gamma ray emission from compact objects including the Crab Nebula, and the discovery of Geminga.
The SAS II gamma ray telescope's successful results during the 1970s brought gamma ray astronomy of age and established it as the newest astrophysics field. Under Ögelman's leadership, his group carried out actual data analysis at METU with graduate and undergraduate students, and contributed significantly to the SAS II project's success. By that time the once-fledgling field of gamma ray astronomy had since grown into a major science utilizing numerous other space-based and balloon-born telescopes, and many important discoveries have been made extending astronomy to the high energy region.
In 1973 Ögelman took a leave of absence from METU to complete his army service. In 1974 he took a sabbatical leave of absence to serve as a National Academy of Sciences Senior Research Associate at the Goddard Space Flight Center in Greenbelt, Maryland, working with his colleagues at NASA's Gamma Ray Astronomy Group led by Dr. Carl E. Fichtel. Ögelman returned to METU in 1975, becoming a full professor in 1976.
In 1977, at the invitation of the president of Çukurova University (CÜ) in Adana, Turkey, Ögelman took another leave of absence and with three of his METU colleagues (and, later, some of his graduate and post graduate students from METU, who formed the core of the new Physics Department) moved to Çukurova to start and establish its Faculty of Arts and Sciences. Becoming the founding Dean of the faculty, he decided to take students without delay, and the group started classes in barracks. Eventually, Ögelman arranged for funding from the Ford Foundation and the USAID to start a modern research laboratory in the campus. He also took an interest in the local economy and needs of the people, and encouraged the faculty to research in fields with most benefit to the region. One of the most important topics to address at that time concerning physics was Turkish society's energy needs. Ögelman gave priority to solar energy research in the Physics Department because in the Çukurova region there is plenty of sunshine throughout the year. To this end, as he had at METU, he started research in solar energy, building Turkey's first energy efficient solar house and a solar pond. Ögelman left Çukurova in 1982 to return to METU but continued working with his previous students as colleagues on astrophysics.
From July 1983 to July 1985, Ögelman again took a leave of absence from METU, spending the period as a guest scientist at the Max Planck Institute for Extraterrestrial Physics (MPE) in Munich, Germany. Ögelman then became a resident scientist at MPE and worked there from July 1985 to January 1991. He started working on X-ray data of the Einstein and Exosat satellites. After the launch of the hugely successful ROSAT (Röntgensatellit - German X-Ray Satellite) Observatory (June 1, 1990 – February 12, 1999) led by Principal Investigator (PI) Joachim Trümper at MPE and developed through a cooperative program between Germany, the United States, and the United Kingdom, Ögelman became one of the main investigators with this satellite. ROSAT performed the first all sky surveys with imaging telescopes, leading to the discovery of 125,000 X-ray and 479 EUV sources. In addition the diffuse galactic X-ray emission was mapped with unprecedented angular resolution (< 1 arcmin). Most of the mission time was devoted to pointed observations at selected targets. In total 4,580 PSPC (Position Sensitive Proportional Counter) and 4482 HRI fields were covered with observation times between ~ 2,000 sec and ~ 1 Million sec. 700 Scientists (PIs) from 24 countries were involved in these pointed observations. The total number of ROSAT based publications is 4787, with 54,9 % in referred journals (status August 2001). Ögelman took part in the analysis of ROSAT data from the beginning and published some of his most exciting research work.
In 1983 he proposed X-ray observations of a classical nova in outburst (GQ Mus) with Exosat. The nova turned to be a luminous X-ray source in the lowest range of X-ray energy (called "supersoft") proving the thermonuclear burning on the surface of a white dwarf, thought to be the cause of the outburst. With ROSAT Ögelman and collaborators could establish that novae in outburst are among the most luminous sources in the X-ray sky.
In 1988 Ögelman was awarded Turkey's highest scientific honor, the Sedat Simavi Prize. In 1991, he received the Turkish Scientific and Technical Research Council Prize. He represented Turkey on international science councils and co-operations, and served on NASA committees and working groups. He was instrumental in the 1991 establishment of the TÜBİTAK National Observatory. Around this time Ögelman's second marriage ended. He began seeing and subsequently married an Italian astronomer, Marina Orio; they spent the remainder of his life together.
University of Wisconsin
At Max Planck, Ögelman had met the University of Wisconsin astrophysicist Prof. William F. "Jack" Fry, who would become a good friend and mentor. Fry returned to the University of Wisconsin from MPE with an interest in building up the Wisconsin astrophysics program by adding a high energy astrophysics group to complement the astroparticle and neutrino group. He persuaded Hakkı Ögelman to join the Wisconsin faculty, first as a visiting professor from January 1991 to September 1992, and, then, from the end of 1992, as a full-time professor. One of Ögelman's METU students, Prof. A. Baha Balantekin, was already at Wisconsin University Physics Department, having arrived in 1986. (Balantekin served as department chairman between 2008 and 2011.)
During Ögelman's tenure at Wisconsin, he continued to pursue his interest in compact objects, and published roughly sixty papers on the subject between 1991 and 1998. As time passed and experiments became larger and more institutional, Ögelman devoted an increasing amount of time to data analysis and worked on analyzing the data from major X-ray missions such as the ROSAT Telescope, Beppo-SAX, and the Chandra X-ray Observatory.
While at Wisconsin, Ögelman visited METU, Sabancı University and Çukurova University in Turkey nearly every summer. He visited and worked with his former graduate students Profs. Ümit Kızıloğlu Mehmet Emin Özel, Akif Esendemir, Solen Balman and with İlhami Yeğingil at Çukurova—all of whom had become professors by this time—and also with Prof. Altan Baykal. Ögelman especially spent significant amount of time with Prof. Ali Alpar at Sabancı University, a private university in Istanbul on pulsar research and jointly publishing several papers, which he considered to be some of his best work. Ögelman also took part and/or organized several scientific symposiums, conferences meetings with his colleagues in Turkey.
In 1997, Ögelman suffered a major stroke. His life was saved by the intervention and treatment of University of Wisconsin doctors. He returned to work after his recovery and carried on working on his research but at a slower pace. Life was difficult for him because his movement was limited. In the spring of 2011, Ögelman's declining health forced his retirement.
Personal life
Ögelman loved music, literature and sports. He was a competitive wrestler in college and a black belt in judo. Ögelman in his later years also turned his robust intellect and attention to exploring sustainable solutions to the changing climate and the world's evolving energy needs. He was an active member of the Union of Concerned Scientists. Ögelman enjoyed time and travel with his three sons and a daughter-in-law, Kenan Ögelman of Austin, Texas, Nedim and Laura Ögelman of Purcellville, Virginia, and Roberto Ögelman of Madison, Wisconsin, and two grandsons; Anders and Soren Ögelman, of Purcellville, Virginia.
Hakkı Ögelman died on September 4, 2011. In his memory, the Turkish Astronomical Society established the Hakkı Ögelman Summer Schools, to "offer intense summer training to undergraduate and graduate students of astronomy from all over Turkey, in physics, computation and other subjects related to research in astronomy." The Turkish Philanthropy Funds coordinates international contributions to this project.
Academic history
Member of NASA's High Energy Astrophysics Management Operations Working Group (1995 forward)
Member of the Turkish Academy of Sciences (1994 forward)
Executive Committee member of the High Energy Astrophysics Division of the High Energy Astrophysics Division of the American Astronomical Society (1993–95)
Board member of the Astronomy and Astrophysics Division of the European Physics Society (1983–91)
Member of the Space Science Council of the European Science Foundation (1979–86)
Science Council member of the Turkish Science and Technology Research Council (TÜBITAK) (1976–83)
Executive Council member of the European Science Foundation (1980–83)
A member of the European Physical Society, the Turkish Physical Society, the American Astronomical Society, and the International Astronomical Union
Consultant, Scientific and Technical Research Council of Turkey (1993–94)
Professor, Department of Physics, University of Wisconsin September (1991–2011)
Scientist, Max-Planck Institut für Extraterrestrische Physik Garching bei München, F.R. Germany (July 1985-January 1991)
Guest Scientist, Max-Planck Institut für Extraterrestrische Physik Garching bei München, F.R. Germany (on leave from METU, Ankara) (July 1983 - July 1985)
Professor, Physics Department, Middle East Technical University (METU) Ankara, Turkey (February 1970 - July 1985)
Dean, Faculty of Basic Sciences, Çukurova University, Adana, Turkey (on leave from METU, Ankara) (September 1978 - June 1981)
National Academy Sciences Senior Research Associate at Goddard Space Flight Center (on leave from METU, Ankara) (September 1974 - September 1975)
National Academy Sciences Research Associate at Goddard Space Flight Center (September 1967 - January 1970)
Awards, prizes and honors
Sedat Simavi Prize, 1988
Turkish Scientific and Technical Research Council Science Prize, 1991
Selected publications
References
Further reading
Ögelman, Hakkı (2002). Personal website Compact Objects at Wisconsin website
1940 births
2011 deaths
Astrophysicists
Cornell University alumni
DePauw University alumni
Academic staff of Middle East Technical University
Recipients of TÜBİTAK Science Award
Robert College alumni
Turkish emigrants to the United States
Turkish physicists
University of Wisconsin–Madison faculty
Academic staff of Çukurova University | Hakkı Ögelman | [
"Physics"
] | 2,799 | [
"Astrophysicists",
"Astrophysics"
] |
41,341,441 | https://en.wikipedia.org/wiki/K-trivial%20set | In mathematics, a set of natural numbers is called a K-trivial set if its initial segments viewed as binary strings are easy to describe: the prefix-free Kolmogorov complexity is as low as possible, close to that of a computable set. Solovay proved in 1975 that a set can be K-trivial without being computable.
The Schnorr–Levin theorem says that random sets have a high initial segment complexity. Thus the K-trivials are far from random. This is why these sets are studied in the field of algorithmic randomness, which is a subfield of Computability theory and related to algorithmic information theory in computer science.
At the same time, K-trivial sets are close to computable. For instance, they are all superlow, i.e. sets whose Turing jump is computable from the Halting problem, and form a Turing ideal, i.e. class of sets closed under Turing join and closed downward under Turing reduction.
Definition
Let K be the prefix-free Kolmogorov Complexity, i.e. given a string x, K(x) outputs the least length of the input string under a prefix-free universal machine. Such a machine, intuitively, represents a universal programming language with the property that no valid program can be obtained as a proper extension of another valid program. For more background of K, see e.g. Chaitin's constant.
We say a set A of the natural numbers is K-trivial via a constant b ∈ if
.
A set is K-trivial if it is K-trivial via some constant.
Brief history and development
In the early days of the development of K-triviality, attention was paid to separation of K-trivial sets and computable sets.
Chaitin in his 1976 paper mainly studied sets such that there exists b ∈ with
where C denotes the plain Kolmogorov complexity. These sets are known as C-trivial sets. Chaitin showed they coincide with the computable sets. He also showed that the K-trivials are computable in the halting problem. This class of sets is commonly known as sets in arithmetical hierarchy.
Robert M. Solovay was the first to construct a noncomputable K-trivial set, while construction of a computably enumerable such A was attempted by Calude, Coles and other unpublished constructions by Kummer of a K-trivial, and Muchnik junior of a low for K set.
Developments 1999–2008
In the context of computability theory, a cost function is a computable function
For a computable approximation of set A, such a function measures the cost c(n,s) of changing the approximation to A(n) at stage s. The first cost function construction was due to Kučera and Terwijn. They built a computably enumerable set that is low for Martin-Löf-randomness but not computable. Their cost function was adaptive, in that the definition of the cost function depends on the computable approximation of the set being built.
A cost function construction of a K-trivial computably enumerable noncomputable set first appeared in Downey et al.
We say a set A obeys a cost function c if there exists a computable approximation of A,
K-trivial sets are characterized by obedience to the Standard cost function, defined by
where
and is the s-th step in a computable approximation of a fixed universal prefix-free machine .
Sketch of the construction of a non-computable K-trivial set
In fact the set can be made promptly simple. The idea is to meet the prompt simplicity requirements,
as well as to keep the costs low. We need the cost function to satisfy the limit condition
namely the supremum over stages of the cost for x goes to 0 as x increases. For instance, the standard cost function has this property. The construction essentially waits until the cost is low before putting numbers into to meet the promptly simple requirements. We define a computable enumeration such that
. At stage s> 0 , for each e < s, if has not been met yet and there exists x ≥ 2e such that and , then we put x into and declare that is met. End of construction.
To verify that the construction works, note first that A obeys the cost function since at most one number enters A for the sake of each requirement. The sum S is therefore at most
Secondly, each requirement is met: if is infinite, by the fact that the cost function satisfies the limit condition, some number will eventually be enumerated into A to meet the requirement.
Equivalent characterizations
K-triviality turns out to coincide with some computational lowness notions, saying that a set is close to computable. The following notions capture the same class of sets.
Lowness for K
We say that A is low for K if there is b ∈ such that
Here is prefix-free Kolmogorov complexity relative to oracle .
Lowness for Martin-Löf-randomness
A is low for Martin-Löf-randomness if whenever Z is Martin-Löf random, it is already Martin-Löf random relative to A.
Base for Martin-Löf-randomness
A is a base for Martin-Löf-randomness if A is Turing reducible to Z for some set Z that is Martin-Löf random relative to A.
More equivalent characterizations of K-triviality have been studied, such as:
Lowness for weakly-2-randomness;
Lowness for difference-left-c.e. reals (notice here no randomness is mentioned).
Developments after 2008
From 2009 on, concepts from analysis entered the stage. This helped solving some notorious problems.
One says that a set Y is a positive density point if every effectively closed class containing Y has positive lower Lebesgue density at Y. Bienvenu, Hölzl, Miller, and Nies showed that a ML-random is Turing incomplete iff it is a positive density point. Day and Miller used this for an affirmative answer to the ML-cupping problem: A is K-trivial iff for every Martin-Löf random set Z such that A⊕Z compute the halting problem, already Z by itself computes the halting problem.
One says that a set Y is a density-one point if every effectively closed class containing Y has Lebesgue density 1 at Y. Any Martin-Löf random set that is not a density-one point computes every K trivial set by Bienvenu, et al. Day and Miller showed that there is Martin-Löf random set which is a positive density point but not a density one point. Thus there is an incomplete such Martin-Löf random set which computes every K-trivial set. This affirmatively answered the covering problem first asked by Stephan and then published by Miller and Nies. For a summary see L. Bienvenu, A. Day, N. Greenberg, A. Kucera, J. Miller, A. Nies, and D. Turetsky.
Variants of K-triviality have been studied:
Schnorr trivial sets where the machines have domain with computable measure.
strongly jump traceable sets, a lowness property of sets far inside K-triviality.
References
Computability theory
Algorithmic information theory | K-trivial set | [
"Mathematics"
] | 1,531 | [
"Computability theory",
"Mathematical logic"
] |
41,341,760 | https://en.wikipedia.org/wiki/OpenPHACTS | Open PHACTS (Open Pharmacological Concept Triple Store) was a European initiative public–private partnership between academia, publishers, enterprises, pharmaceutical companies and other organisations working to enable better, cheaper and faster drug discovery. It has been funded by the Innovative Medicines Initiative, selected as part of three projects to "design methods for common standards and sharing of data for more efficient drug development and patient treatment in the future".
Partnerships
A total of 27 partners were involved including:
Academia: Maastricht University, University of Santiago de Compostela, University of Vienna, University of Manchester, University of Bonn, Swiss Institute of Bioinformatics, European Bioinformatics Institute, Vrije Universiteit of Amsterdam, Technical University of Denmark, University of Hamburg
Pharmaceutical companies: Pfizer, Merck KGaA, Eli Lilly and Company, Novartis, GlaxoSmithKline, AstraZeneca
Other companies: ChemSpider, Biovia, Eagle Genomics, Entagen
Publishers: Royal Society of Chemistry, Thomson Reuters
Drug discovery
The Open Pharmacological Space created by the consortium intended to support open innovation and in-house non-public drug discovery research by removing bottlenecks in drug development. Resources from the project are publicly available on GitHub.
To reduce the barriers to drug discovery in industry, academia and for small businesses, the Open PHACTS consortium built the Open PHACTS Discovery Platform. This platform was freely available, integrating pharmacological data from a variety of information resources and providing tools and services to question this integrated data to support pharmacological research.
References
Information technology organizations based in Europe
Drug discovery
Medical databases | OpenPHACTS | [
"Chemistry",
"Biology"
] | 343 | [
"Life sciences industry",
"Medicinal chemistry",
"Drug discovery"
] |
41,342,771 | https://en.wikipedia.org/wiki/OpenLMI | OpenLMI (abbreviated from Open Linux Management Infrastructure) provides a common management infrastructure for Linux systems. Available operations include configuration of various operating system parameters and services, hardware components configuration, and monitoring of system resources. Services provided by OpenLMI can be accessed both locally and remotely, using multiple programming languages and standardized APIs.
Project's source code is distributed under the GNU Lesser General Public License (LGPL) and Simplified BSD License.
Overview
OpenLMI distinguishes agents, controllers and client applications:
OpenLMI agents perform the actual operations; they are installed and run on managed Linux systems.
OpenLMI controllers manage the OpenLMI agents.
Client applications talk to the OpenLMI controllers through well-defined interfaces and language bindings, which are based on open industry standards for the management of remote systems.
Thus, instead of delivering a complete management solution, OpenLMI provides low-level functions and APIs that can be used by, or integrated into, various management platforms, applications or configuration scripts.
OpenLMI extends the already existing Linux infrastructure by providing management agents which also perform system configuration tasks, in addition to monitoring and reporting functions. By exporting those operations through standard-based interfaces, and by providing agents performing the actual operations, OpenLMI creates a management framework that various applications can use both for system configuration, and for monitoring resources and performance. Usage targets for OpenLMI include bare-metal production servers, on which it can perform initial configurations through a set of predefined "recipes".
, implemented agents primarily perform operations related to storage, networking and local user accounts. Plans exist to expand the variety of implemented agents, aiming at providing complete coverage of Linux management and configuration tasks.
The OpenLMI's source code is licensed under the GNU Lesser General Public License (LGPL) and Simplified BSD License (also known as the FreeBSD License).
Architecture
Based on their placement and usage role, OpenLMI architecture contains two major components: management modules (also known as agents), and management tools. A set of management modules is installed and running on each of the managed systems, performing the configuration and monitoring tasks. Management tools are running on a management system, performing aggregation of the collected monitoring data, and dispatching the requests to management modules. The agents are talking to the outside world through an OpenLMI Object Broker, which is also known as a controller. This object request broker provides a standard-based communications protocol, handles the security and access control, and provides deployment methods for the agents.
Each agent implements an object model that specifies the attributes (information), methods (functions), and associations (links to other objects). Through the controller, this object model is interoperably made available to client applications. While it is possible to build all required logic into an agent, the general approach is to use and invoke existing Linux tools; for example, OpenLMI's network agent uses the NetworkManager, and the storage agent uses the Blivet storage library.
The actual communication protocol is using XML data transferred over HTTPS. While it is possible to use XML directly, a set of client libraries provides native interfaces for a number of programming languages; client libraries supplied by OpenLMI provide support for C, C++, Python and Java. These interfaces are implemented as language bindings to the operations in underlying system agents, with all supplied libraries providing the same feature sets. Support for command-line interface (CLI) utilities is also provided.
Internally, OpenLMI is based on the Distributed Management Task Force (DMTF) Common Information Model (CIM), with internal functions exposed in form of CIM namespaces. A few open-source CIM clients are available, as an additional way for using data and operations exported through OpenLMI.
Agents
OpenLMI agents, also called providers, do the actual work. OpenLMI distribution includes a set of standard management agents, and also includes a set of development resources required for developing new agents. Standard OpenLMI agents, , are the following:
Storage
Storage Agent configures and manages local and remote storage. The ability to enumerate (discover) and configure local storage devices is built-in. As of December 2013, remote storage devices can be configured, with no support for their discovery or provisioning. Thus, remote storage must be already provisioned using other approaches, and the resulting logical unit number (LUN) made available to this agent. Support for provisioning of remote storage is planned for future releases.
Networking
Networking Agent configures and manages network interface controllers (NICs) and Linux networking configuration in general. It has the ability to enumerate (discover) and configure devices, including configuration of IPv4 and IPv6 addresses, default gateways, DNS servers, management of static routes, and configuration of interfaces bridging and bonding.
System Services
System Services Agent performs the management operations associated with the system services and underlying background processes, by exposing the ability for services to be, for example, started, stopped or restarted through the standard OpenLMI interface. This agent also has the ability to enumerate (discover) available system services, using the systemd's D-Bus interface.
User Accounts
User Accounts Agent configures and manages local user accounts, local user groups, groups membership, and accounts parameters such as the default shell, home directory, password, and password expiration. This agent also has the ability to enumerate (discover) available local user accounts and local user groups.
Software
Software Agent configures and manages software packages on a managed system. It has the ability to list the software installed on a system, install new software, update existing software, and remove installed software. It also has the ability to verify integrity of installed packages and their files, while using all configured repositories.
Hardware
Hardware Agent manages hardware components, providing detailed information on their presence and associated configurations. Provided information includes the CPU-related data (number of cores, clock and FSB speeds, cache sizes, etc.), system memory (size, speed, available memory slots, installed modules, etc.), physical asset data (chassis info, available ports and slots, etc.), battery (available capacity, running voltage, etc.), and PCI devices and bridges (available buses, IDs of devices, device vendors, etc.)
Logging
Journald Agent provides access to logging records through the standard OpenLMI interface. It is a client of systemd's journald service, accessing the journald records in several ways and providing a way to store new log records. Journald, as a structured logging system, stores supplemental information along each record, making it easier to find and extract information from the resulting log files.
Performance CoPilot
Performance CoPilot Agent provides access to various system statistics and performance monitoring data collected by the Performance Co-Pilot (PCP) service running locally on a monitored host. PCP is capable of providing monitoring data for various services, including web, email and database servers, and virtualization environments. Collected data may have any type of value, including integers, strings, floating point numbers, and arbitrary composite data structures.
Comparison
OpenLMI is different from other configuration management systems like Puppet or Bcfg2, in a way that OpenLMI does not require details of the system configuration to be already known in order for appropriate configuration recipes to be created. This nature of the OpenLMI may provide advantages in case initial configuration is to be performed on a broader variety of systems having different hardware configurations.
Reception
Red Hat Enterprise Linux 7.0 includes support for OpenLMI since the first beta release of this Linux distribution, which was made available on December 11, 2013. Fedora 20, released on December 17, 2013, also includes support for OpenLMI.
See also
Bcfg2
Comparison of open-source configuration management software
Puppet
Simple Network Management Protocol (SNMP)
References
External links
OpenLMI API documentation
OpenLMI development resources
Distributed Management Task Force (DMTF)
Configuration management
Linux configuration utilities | OpenLMI | [
"Engineering"
] | 1,666 | [
"Systems engineering",
"Configuration management"
] |
41,343,013 | https://en.wikipedia.org/wiki/UNC-5 | UNC-5 is a receptor for netrins including UNC-6. Netrins are a class of proteins involved in axon guidance. UNC-5 uses repulsion to direct axons while the other netrin receptor UNC-40 attracts axons to the source of netrin production.
Discovery of netrins
The term netrin was first used in a study done in 1990 in Caenorhabditis elegans and was called UNC-6. Studies performed on rodents in 1994 have determined that netrins are vital to guidance cues. The vertebrate orthologue of UNC-6, netrin-1 was determined to be a key guidance cue for axons moving toward the ventral midline in the rodent embryo spinal cord. Netrin-1 has been identified as a critical component of embryonic development with functions in axon guidance, cell migration, morphogenesis and angiogenesis. The most recent studies have found that there are 5 types of netrins expressed in animals. Ectotopic expression of UNC-5 can result in short or long range repulsion.
Axon guidance
The guidance of axons to their targets in the developing nervous system is believed to involve diffusible chemotropic factors secreted by target cells. Floor plate cells at the ventral midline of the spinal cord secrete a diffusible factor or factors that promotes the outgrowth of spinal commissural axons and attracts these axons in vitro. Recent studies indicate that several axon guidance mechanisms are highly conserved in all animals, whereas others, though still conserved in a general sense, show strong evolutionary divergence at a detailed mechanistic level. Expression of UNC-6 netrin and its receptor UNC-5 is required for guiding pioneering axons and migrating cells in C. elegans. Netrins are axon guidance molecules that transmit their activity through 2 different receptors. The function of UNC-5 is to repel axons while the other receptor UNC-40 (or Deleted in Colorectal Cancer) attracts axons to the source of UNC-6 production. Methods such as antibody staining, transgene expression and microarray analysis have confirmed that UNC-5 is expressed in DA9 motor neurons. Eight pairs of chemosensory neurons in Caenorhabditis elegans take up fluorescein dyes entering through the chemosensory organs. When filled with dye, the processes and cell bodies of these neurons can be examined in live animals by fluorescence microscopy. Using this technique five genes were identified: unc-33, unc-44, unc-51, unc-76, and unc-106. These genes we found to affect the growth of the amphid and phasmid axons in mutants.
Cell migration
There are three phases in hermaphrodite distal tip cell migration in Caenorhabditis elegans which are distinguished by the orientation of their movements which alternate between anteroposterior and dorsoventral axes. Experimentation has shown that UNC-5 is coincident with the second migration phase and that premature expression will result in turning in a UNC-6 dependent manner. This also demonstrates the mechanism that regulates UNC-5 is critical for UNC-6 netrin guidance cue responsiveness. Although it normally guides axons along the dorsoventral axis, UNC-40 can be co-opted with SAX-3 to affect cell migrations along the anterior posterior axis. VAB-8 protein is identified as an upstream regulator for UNC-40 and identifies the mechanism for polarity in axon and cell migration.
Formation
Growth
An experiment was performed to determine if UNC-5 is required for localization of presynaptic components in DA9. When testing the effect of unc-5::intron::unc-5 transgene on a mislocalization defect in UNC-5 mutant animals at 25 °C a significant rescue of the mislocalization defect was observed. In mutant animals, ventral and dorsal migrations are disrupted but longitudinal movements are unaffected. They discovered that this rescue does not occur at 16 °C because the transgene fails to produce UNC-5 at that temperature. This is relevant because is shows that the mislocalization defect is due to a change in temperature at the L4 larval stage which occurs after DA9 is fully developed. This suggests that UNC-5 is only required for the early outgrowth phase to guide axons. UNC-5 presents a novel function in maintaining polarized localization of GFP::RAB-3 independently of early polarization and guidance. When testing directly for whether UNC-6 netrin provides information for localization of presynaptic components an interesting discovery was made. The egl-20::unc-6 transgene creates an enlarged asynaptic zone of the DA9 dorsal axon. They further observed that the enlarged asynaptic domain is restored partly in UNC-5 which demonstrates that UNC-5 acts cell autonomously in DA9 in order to mediate ectopic UNC-6 exclusion of presynaptic components. The UNC-6 gradient is high ventrally and low dorsally and encompasses the dendrite and ventral axon of DA9. UNC-6 was recently found to cause the initial polarization of the C. elegans hermaphrodite specific neuronal cell body. The findings of this experiment suggest that UNC-6 and UNC-5 coordinate two different functions in DA9 and that the netrin is expressed after axon guidance is complete. Extracellular cues such as Wnt fibroblast growth factor can promote synapse formation, contradicting the traditional view of synapse formation from contact between synaptic partners to trigger the assembly of synaptic components. Inhibitory factors such as UNC-5 play essential roles in the formation and maintenance of synaptic components.
Adult expression
In a study done in rat spinal cords, increased netrin-1, UNC-5 homologue levels were observed compared to lower levels measured in the embryo. From this study multiple mRNA transcripts were detected by northern blot analysis. This finding suggests that netrin receptors could be encoded by alternatively spliced mRNAs. During embryonic development only one splice variant is detected while there are two in the adult model. The results of these findings suggest that UNC-5 homologues make up a primary method of netrin-1 signal transduction in the adult spinal cord. This shows that netrin-1 plays a major role in the adult brain and has the potential for therapeutic applications.
Plasticity
Similar to growth cone guidance, synapse formation is cued by UNC-5 through a UNC-6 gradient that repels the dorsal axon migration. Dendritic filopodia extend from the dendritic shaft during synaptogenesis and appear as though they are reaching out for a presynaptic axon. Despite the appearance of attaching to an axon, cell signaling is still required for complete synaptic formation. An experiment was performed to determine the role of UNC-5 in axonal growth after spinal cord injury. The netrin is expressed by neurons in the corticospinal and rubrospinal projections, and by intrinsic neurons of the spinal cord both before and after the injury. When testing in vitro UNC-5 receptor bodies are taken from the spinal cord to neutralize netrin-1 in myelin. This increases the neurite outgrowth from UNC-5 expressing spinal motor neurons.
UNC-129
UNC-129 is a ligand in the transforming growth factor family in C. elegans which encodes transforming growth factor β (TGF-β). Like UNC-6 it guides pioneer axons along the dorsoventral axis of C. elegans. TGF-β is expressed only in dorsal rows of body wall muscles and not ventral. Ectotopic expression of UNC-129 from the muscle results in disrupted growth cone and cell migrations. This shows that UNC-129 is responsible for mediating expression of dorsoventral polarity required for axon guidance. Recent findings have shown that UNC-129 is also responsible for long range repulsive guidance of UNC-6. This mechanism enhances UNC-40 signaling while inhibiting UNC-5 alone. This causes an increase in sensitivity in growth cones to UNC-6 as they travel up the UNC-129 gradient. UNC-129 mediates expression of dorsoventral polarity information required for axon guidance and guided cell migrations in Caenorhabditis elegans.
Dendritic self avoidance
Recently it was found that dendrites do not overlap and actively avoid each other because cell specific membrane proteins trigger mutual repulsion. In the absence of UNC-6 signaling however, dendrites failed to repel each other. This finding supports the idea that UNC-6 is critical for axon and dendritic guidance in the developmental stage. It is also known that self avoidance requires UNC-6 but not a UNC-6 graded signal. A ventral to dorsal UNC-6 gradient is not required for expression and dendritic self avoidance is independent of such a gradient. UNC-6 that binds to UNC-40 takes on different properties and functions as a short range guidance cue.
Vertebrate laminins
Netrins share the same terminal structure with vertebrate laminins but appear minimally related. The basement membrane assembly across species, Vertebrate laminin-1 (α1β1γ1) and laminin-10 (α5β1γ1), like the two Caenorhabditis elegans laminins, are embryonically expressed and are essential for basement membrane assembly. During the basement assembly process laminins anchor to the cell surface through their G domains after polymerizing through their LN domains. Netrins are involved in heterotropic LN domain interactions during this process which suggests that although similar in structure, the functions of the two families are different.
Applications
Tumorigenesis
Netrin-1 and its receptors DCC and UNC-5 show a new mechanism for induction or suppression regulation of apoptosis. Evidence shows that this signaling pathway in humans is frequently inactivated. During the last 15 years, controversial data has failed to firmly establish whether DCC is indeed a tumour suppressor gene. However, the recent observations that DCC triggers cell death and is a receptor for netrin-1, a molecule recently implicated in colorectal tumorigenesis. The established role of DCC and netrin-1 during organization of the spinal cord could be viewed as a further challenge to the position that DCC inactivation might play a significant role in tumorigenesis. Recent observations on DCC's functions in intracellular signaling have renewed interest in the potential contribution of DCC inactivation to cancer. Data shows that, when engaged by netrin ligands, DCC may activate downstream signaling pathways and in settings where netrin is absent or at low levels, DCC can promote apoptosis. The binding of netrin-1 to its receptors inhibits the tumor suppressor p53 dependent apoptosis. Such receptors share the property of inducing apoptosis in the absence of ligand, hence creating a cellular state of dependence on the ligand. Thus, netrin-1 may not only be a chemotropic factor for neurons but also a survival factor. This discovery shows that netrin-1 receptor pathways play an important role in tumorigenesis.
Schwann cells
A study was performed to determine the effect of netrin-1 on schwann cell proliferation. Unc5b is the sole receptor expressed in RT4 schwannoma cells and adult primary Schwann cells, and netrin-1 and Unc5b are found to be expressed in the injured sciatic nerve. It was also found that the netrin-1-induced Schwann cell proliferation was blocked by the specific inhibition of Unc5b expression with RNAi. These data suggests that netrin-1 could be an endogenous trophic factor for Schwann cells in the injured peripheral nerves.
See also
Netrin
Neural development
Axon guidance
Pioneer axon
Neural development in humans
Human brain development timeline
References
Further reading
Receptors
Single-pass transmembrane proteins | UNC-5 | [
"Chemistry"
] | 2,604 | [
"Receptors",
"Signal transduction"
] |
41,343,156 | https://en.wikipedia.org/wiki/Migration%20of%20marine%20species%20in%20the%20Northern%20Atlantic%20Ocean | Due to the warming of the Atlantic Ocean caused by climate change, many species of fish are beginning to shift north towards cooler waters within their temperature range. Tropical species are being found outside their normal range and into more northern waters causing an array of ecological, economic, and fishery management problems.
Research
William Cheung, a professor at the University of East Anglia, in the Sea Around Us Project at the University of British Columbia concluded that the oceans were warming at an average of per decade and at per decade in tropical waters. However, the north-east Atlantic has been warming at a rate of per decade. Cheung and his colleagues were able to get these estimates by using the mean temperature of catch. They used data from 990 species within 52 marine ecosystems from 1970-2006. Using fisheries data and computer models, Cheung was able to estimate the shift of species. Species are migrating north at an average rate of per decade. The study predicted that there will be a 60% shift of species towards northern waters within the next 41 years.
Species shifting north
Atlantic surf clams that were once common off the coasts of Delaware, Virginia, and Maryland are now rare, but are now more common in deeper waters off the coast of New England.
Red Mullet that were common in the Mediterranean are now found in the North Sea off the Coast of Great Britain and Norway.
Species of Triggerfish and Grouper from the Gulf of Mexico are now being caught in Mid-Atlantic waters.
Lionfish native to the western Pacific are invasive species in the Gulf of Mexico but are now being found off the coast of North Carolina.
Potential issues
The Northern Shrimp population may decline in the future. The shrimp larvae hatching period is dependent upon certain temperatures. Once the larvae hatch, they feed on an annual algal bloom. There is a strong correlation between the larvae hatching and when the algal bloom occurs. The changing ocean temperature may result in a mismatch in time with the larvae and algal bloom which could cause a decline in the Northern shrimp population.
The Red mullet migration into the northern Atlantic could catalyze the decline of cod. Red mullet could outcompete Cod, eventually replacing the species. Emily Pidgeon, the senior director of strategic marine initiatives at Conservation International, stated that the worldwide cod population could decrease by almost half by 2050.
References
Animal migration
Biota of the Atlantic Ocean | Migration of marine species in the Northern Atlantic Ocean | [
"Biology"
] | 480 | [
"Biota of the Atlantic Ocean",
"Behavior",
"Animal migration",
"Ethology",
"Biota by sea or ocean"
] |
41,344,078 | https://en.wikipedia.org/wiki/Phialemonium%20curvatum | Phialemonium curvatum is a pathogenic fungus in the phylum Ascomycota. The genus was created to accommodate taxa intermediate to Acremonium and Phialophora. This genus is characterized by its abundance of adelophialides and few discrete phialides with no signs of collarettes. Specifically, P. curvatum is characterized by its grayish white colonies and its allantoid conidia. Phialemonium curvatum is typically found in a variety of environments including air, soil, industrial water and sewage. Furthermore, P. curvatum affects mainly immunocompromised and is rarely seen in immunocompetent people. The species has been known to cause peritonitis, endocarditis, endovascular infections, osteomyelitis as well as cutaneous infections of wounds and burns.
Description and identification
Phialemonium curvatum was first described by W. Gans et McGinnis in 1983. It is noted as being pigmented although it lacks dark pigmentation. The colony appearance is flat and glabrous with a white turning yellow appearance surrounded by a yellow pigment surrounding the colony. Conidia of P. curvatum are uniformly cylindrical to bean-shaped with their length ranging from 3.5–6.0 μm and their width varying from 1.0–1.4 μm. A key feature of P. curvatum is its lack of chlamydoconidia, distinguishing it from P. obovatum. As well, the phialides of P. curvatum have poorly defined to absent collarettes with their dimensions varying from 1–7 x 0.5–1.0 μm. Phialemonium curvatum can grow at temperatures between 10–36 °C. Another way of identifying P. curvatum is through the use of PCR and DNA sequencing of the internal transcribed spacer (ITS). By incubating a suspected culture in a GEPD medium at 30 °C, a culture can be grown to allow for the isolation and extraction of genomic DNA. Then through the use ITS1 primers and ITS4, the samples can be amplified, sequenced and analyzed to allow for the identification of P. curvatum.
Pathogenicity
Arthritis
Case studies have shown that P. curvatum is capable of causing arthritis. The source of the infection has often been traced to a penile or intra-articular injection of a corticosteroid. The course of treatment has been to prescribe the patient with amphotericin B and voriconazole.
Endocarditis
Phialemonium curvatum rarely causes heart infections, however immunosuppressed patients are far more likely to become infected due to their lower immune function. Endocarditis is an infection of the heart valves and P. curvatum has been linked to this infection through penile injections or through the transplantation of a prosthetic aortic valve. In the case of endocarditis, P. curvatum forms a mass on the heart valve which if left untreated can lead to the impairment of the heart valve and in turn cause a brain infract and consequently death. The key to treating endocarditis caused by P. curvatum is to treat the patient as soon as possible with antifungal medications such as amphotericin B and voriconazole.
Endophthalmitis
Phialemonium curvatum has been found to be capable of causing endophthalmitis particularly in immune compromised patients. Endophthalmitis is an inflammatory response typically due to an infection of the intraocular cavities. In reference specifically to P. curvatum, hypopyon (an accumulation of pus) as well as vitreous opacities are visible in patients with endophthalmitis. Reported sources of infection can include self intracavernous injections to treat erectile dysfunction as well as phacoemulsification. Histological findings documented in the case study by Weinberger et al. include: necrotizing granulomata, chronic lymphocytic infiltration and fine septate hyphae. Treatment options vary depending on the severity of the infection however, treatment usually consists of antifungal medication such as amphotericin B. Furthermore, the patient may undergo a cataract extraction (if present) and a pars plana vitrectomy. If the patient remains unresponsive to the treatment, then enucleation of the infected eye may be necessary.
Peritonitis
Phialemonium curvatum has been known to peritonitis, which is a phaeohyphomycosis affecting the peritoneal cavity, and is responsible for 1-10% of infections in patients undergoing peritoneal dialysis. This type of phaeohyphomycosis is associated with a high morbidity and mortality rate. To treat patients with this type of infection, they are put on antifungal medications such as: amphotericin B, ketoconazole, flucytosine and fluconazole until repeated peritoneal fluid cultures show no fungal growth.
Subcutaneous infection
The subcutaneous infection caused by P. curvatum commences by forming a small cyst, less than one centimeter in diameter, which is not normally fixed to the skin. As the mass enlarges, the middle of the cyst is filled with purulent material containing most of the fungal hyphae (some hyphae may also be present on the wall of the cyst). As the cyst continues to grow, the mass becomes more dense and can eventually ulcerate. This type of granulomatous infection caused by P. curvatum is characterized by the presence of a number of Langhan-type giant cells, fibroblasts, macrophages surrounded by lymphocytes, as well as a decrease in the number of polymorphonuclear leukocytes. At the centre of the granulomata, it is also possible to identify microabscesses, collagen tissue as well as necrotic debris caused by the fungal hyphae. The typical course of treatment is to surgically remove the cyst and may include antifungal medications.
Other infections
Phialemonium curvatum is known to cause vascular infection in patients undergoing hemodialysis. One of the sources of contamination was found to be contaminated water; other sources may have been renal grafts and bone marrow transplants. There was a report of P. curvatum affecting the lower spine and respiratory system and causing an abscess with purulent material in the middle. The course of treatment included antifungal medications, such amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole and caspofungin, as well as removal of the cyst.
References
Fungi described in 1983
Sordariales
Fungus species | Phialemonium curvatum | [
"Biology"
] | 1,473 | [
"Fungi",
"Fungus species"
] |
41,344,354 | https://en.wikipedia.org/wiki/Melomics109 | Melomics109 is a computer cluster located at Universidad de Málaga used to create digital music. It is part of the Spanish Supercomputing Network, and has been designed to increase the computational power provided by Iamus. Powered by Melomics' technology, the composing module of Melomics109 is able to create and synthesize music in a variety of musical styles. This music has been made freely accessible to everyone. The cluster consists of three cabinets with customized front panels.
Album
0music is the first album composed and interpreted by Melomics109. It was launched in July 2014, and was released in audio (MP3) and editable format (MIDI), under CC0 (public domain) licensing.
External links
Melomics home page
Melomics page at University of Malaga (Spain)
References
Cluster computing
Music technology
Artificial intelligence art
One-of-a-kind computers
Spanish Supercomputing Network | Melomics109 | [
"Technology"
] | 185 | [
"Computing stubs"
] |
41,344,532 | https://en.wikipedia.org/wiki/Myricanone | Myricanone is a cyclic diarylheptanoid isolated from the bark of Myrica rubra (Myricaceae).
References
Diarylheptanoids
Macrocycles
O-methylated natural phenols
Cyclophanes
Ketones
Biphenyls
Methoxy compounds | Myricanone | [
"Chemistry"
] | 64 | [
"Ketones",
"Organic compounds",
"Functional groups",
"Macrocycles"
] |
41,344,820 | https://en.wikipedia.org/wiki/KIF6 | Kinesin family member 6 is a protein that in humans is encoded by the KIF6 gene. This gene encodes a member of the kinesin family of proteins. Members of this family are part of a multisubunit complex that functions as a microtubule motor in intracellular organelle transport.
References
Further reading
Proteins | KIF6 | [
"Chemistry"
] | 71 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
41,344,870 | https://en.wikipedia.org/wiki/Open%20licence%20%28French%29 | The Licence Ouverte / Open Licence is a French open license published on October 18, 2011 by for open data from the State of France. The license was designed to be compatible with Creative Commons Licenses, Open Government License, and the Open Data Commons Attribution License. Information released under the Open License may be re-used with attribution, such as a URL or other identification of the producer. The Open License is used by the city of Bordeaux, France to release data sets.
References
External links
License Ouverte by Etalab
Open data
Licensing
2012 introductions
Copyright licenses | Open licence (French) | [
"Technology"
] | 119 | [
"Computing stubs"
] |
41,345,251 | https://en.wikipedia.org/wiki/Horrible%20Histories%20%282009%20TV%20series%29 | Horrible Histories is a multi-award-winning British children's live-action historical and musical sketch comedy television series, based on the bestselling book series by Terry Deary. The show focuses on the dark, gruesome or scatological aspects of British and other Western world history, spanning from the Stone Age to the post-World War II era. Now in its 11th series, it is produced for CBBC by Lion Television. It was produced in association with Citrus Television from series 3 to 5. The series began airing in 2009, with more than 160 episodes over the 11 series. It changed format and cast in 2015.
Original cast members include Mathew Baynton, Simon Farnaby, Jim Howick, Martha Howe-Douglas, Dominique Moore, Laurence Rickard and Ben Willbond. Current cast includes Tom Stourton, Jessica Ransom, Richard David-Caine, James McNicholas, Harrie Hayes, Emily Lloyd-Saini, Ethan Lawrence, Paul G Raymond, Timmika Ramsay, and Inel Tomlinson. Celebrity guest stars include Rowan Atkinson, Gemma Whelan, Sanjeev Bhaskar, Rob Delaney, Meera Syal, Rose Ayling-Ellis, The League of Gentlemen, Rosie Jones, David Baddiel, Rob Rinder and Fred Sirieix.
In 2024, Horrible Histories marked 15 years on air, during which there have been 11 series, multiple specials and spin-offs, a feature film, and two sold-out BBC Proms. Accolades including nine BAFTAs, and a British Comedy Award – the only children's show to win one. It also was awarded the Best TV Sketch Show at the Comedy.co.uk awards in 2020, 2021 and 2023. Internationally, Horrible Histories won two Rose d'Or for Best Children's programme, the Prix Jeunesse Special Award for Best Children's Show of the last 50 years, an International Emmy Award for Best Kids Factual, and a Banff Rockie Award.
Background
Horrible Histories is based on the British children's historical-comedy book series by Terry Deary, first published by Scholastic UK in 1993 and since expanded into a multimedia franchise. The books and subsequent spin-off materials are intended to pique young children's interest in history via short, factually based but humorously told anecdotes highlighting aspects of the subject not usually covered in more traditional educational sources.
LionTV executive producer Richard Bradley, whose company had previously produced several adult history-themed programmes and whose son was a fan of the Horrible Histories books, was the initial driving force behind a new TV adaptation. Deary was initially skeptical, having had a negative experience with the 2001 animated series, which had only loosely incorporated his concept. He finally agreed to the new project on the condition that it be explicitly "horrible, funny and true". While disclaiming any active role in developing the subsequent series, he would eventually contribute to the writing as well as appearing in several small roles.
The producers were determined that the show be respectful of audience expectations for the Horrible Histories brand, maintaining its familiar visual style and content as far as possible. Early concepts for bringing it to the screen involved framing or interpretive devices, including a ghostly train carrying children into the past, or a wizard storyteller to act as their guide. Eventually Bradley with producer/director Dominic Brigstocke concluded that the material was strong enough to stand on its own, so they developed, in consultation with CBBC executives, a live-action sketch-comedy showcase. Once the writing was underway, the producers further discovered that sticking as closely as possible to the historical truth made it easier for them to find the humour within it. They then introduced a comedy style relying on parodies of familiar modern media conventions as a means of making these historical details more immediately accessible.
To do the material full justice, Brigstocke and series producer Caroline Norris used their industry contacts to put together a creative team consisting mostly of veterans of the adult UK comedy community. The BBC readily agreed to this cross-demographic experiment. They also approved the adoption—insofar as was possible in a programme aimed at young children—of the core franchise precept of "history with the nasty bits left in", which frequently involved "gross-out"-style bodily function humour and comic violence.
The new creative team, while avoiding references aimed specifically at adults, was determined not to adapt the humour to children or otherwise patronise their audience. Instead, they sought to make the best use possible of the material. Norris said that her goal was "to make a show that people would say was too good for children... we started out with really high ambitions." To that end, adult historical satires such as Blackadder and the Monty Python films were shown at the first writers' meeting to demonstrate the proposed tone, and these influences would be visible throughout the show's run.
Once the first series had aired and it was realised that the overall approach was working well, the creative team built on and significantly expanded the scope of the comedy elements for the second. This trend continued through each subsequent series. The net result was a show that immediately appealed to young children while also gaining the increasing respect—and viewership—of older audiences.
Format
The divisions by historical era or civilisation in the book series are carried over in the TV show, focusing on events in or directly affecting Great Britain and (to a lesser extent) the larger Western world. The Inca and Aztec empires are also featured in later series. Sketches are grouped under these divisions, named as in the books, beginning with the Savage Stone Age and including among others the Cut-throat Celts, Awful Egyptians, Groovy Greeks, Rotten Romans, Smashing Saxons, Vicious Vikings, Measly Middle Ages, Terrible Tudors, Slimy Stuarts, Gorgeous Georgians, Vile Victorians and Frightful First World War. The timeline for the most part ended at the Woeful Second World War. During the fifth and final series the show featured a handful of significant post-World War II (or "Troublesome Twentieth Century") events, including the civil rights movement and the Space Race between the US and the USSR. The most recent event referenced was the 1969 Apollo 11 Moon landing.
Each named division has its own title card that appears before each sketch (or group of sketches) set in that era or civilisation, along with a short introductory animation featuring a period-appropriate character. Throughout each sketch, small pop-up signs are used to affirm the truth (or otherwise) of any particularly implausible-seeming concepts mentioned onscreen. The live-action material is intercut with short animated sketches, quizzes and interludes with puppet "host" Rattus Rattus (performed by John Eccleston), who addresses the viewer directly as a presenter, commenting on and clarifying the factual basis behind the humour. Rattus also occasionally holds up pop-up signs himself during sketches.
Sketches were filmed en masse and then cut into episodes by the producers based on creative rather than chronological or other educational considerations, in the manner of a more traditional sketch-comedy series. They often fall under a recurring banner—usually with its own short title sequence—but otherwise vary widely in length, visual style and approach. Many are recognisable parodies of other popular media or celebrities, in formats ranging from spoof commercials to mock TV shows, newscasts, magazines, video games and film trailers. Notable parody inspirations included Masterchef, Wife Swap, Come Dine with Me, Gogglebox and The Apprentice. "Horrible Histories Movie Pitch", in which historical figures pitch their life stories to a panel of Hollywood producers played by League of Gentlemen actors Mark Gatiss, Steve Pemberton and Reece Shearsmith, used the format of a former commercial campaign for Orange's cinema reminders to turn mobiles off.
The show also created several popular recurring characters and concepts, notably "Stupid Deaths", in which a skeletal, platinum-blond Grim Reaper amuses himself while processing souls for admittance to the afterlife by forcing candidates from throughout history to relate the embarrassing details of their demise. HHTV News' Bob Hale and his eccentric-but-erudite in-studio reports provide a broader picture on historical events (such as the Wars of the Roses and the French Revolution), in a style reminiscent of presenter Peter Snow. The "Shouty Man", a parody of a typically ebullient infomercial host (like Barry Scott), pitches unusual historical products.
Music
Original music plays a significant role in the show and its popularity; "Music from Horrible Histories" was chosen as the 2011 theme of the BBC Proms' annual children's concert. Alongside various short intro themes and commercial jingles, each episode and each special contains at least one longer comedy song centred around a particular historical figure or theme and performed by the cast in appropriate character.
In the first series, the songs generally had no particular satirical slant, and were often intercut with sketches from the same era. However, after the creative team noted the critical and popular success of the major exception ("Born 2 Rule", which featured King Georges I–IV performing in the style of a boyband) the decision was taken from the second series onwards to continue in that vein. Historical concepts were matched to a diverse range of modern musical references, and the results were showcased as self-contained music video parodies. The thirteenth episode of the second and each subsequent series was retooled as a "Savage Songs" special, featuring a compilation of that series' outstanding videos.
The songs have since become among the most critically and popularly acclaimed elements of the show, especially among its adult audience. Commentators cite the apt cleverness of the various historical/musical parody match-ups, and the complexity and skill with which the musical elements are executed. Principal composer Richie Webb confirms that the songs became more sophisticated as a result of the show's increasing popularity with older viewers, as well as the demands of increased visibility online. Many of the videos have earned standalone popularity on YouTube.
The videos tend to run about three minutes, with two significant exceptions. "The Monarchs' Song", from the third series, lists all of the British monarchs since William the Conqueror, using a Chas & Dave-inspired cumulative format. The creative team wrote the song to challenge the show's young audience, after noting that the same youngsters had been inspired to memorise lyrics to previous songs. "We're History", styled as a grand finale for the show's final episode, uses stock footage from across the show's run to revisit every major era it ever featured in turn.
Content and educational value
No formal educational method was applied to the production, and no attempt was made to follow the official UK National Curriculum for primary school history. The show's creators were acutely aware of educational possibilities, but—in line with Deary's overall mandate for the franchise—saw their basic role as popularising history, inspiring further curiosity about the academic subject rather than attempting to teach it seriously. The show's effectiveness in this respect was endorsed by historical scholars, including presenter Dan Snow. Writing in The Independent, Gerard Gilbert notes that Horrible Histories is part of an extensive British black-comedy tradition not only in adult but also in children's programming. In later series, as usable material from the books began to run out, there was a progression towards more sophisticated, adult sketches in terms of both creativity and educational content, as the show began relying on material that their younger viewers would be less familiar with.
Throughout, emphasis was placed on meshing comedy with the demands of historical accuracy, as defined by the mainstream scholarly consensus on the topic. This stance sometimes encompassed traditionally accepted if not actually well-documented anecdotes, such as those involving Caligula. All the material used on the show was vetted by production assistant and self-described "tyrannical pedant" Greg Jenner during both writing and filming; he says that he has counted only eight errors out of more than 4,000 facts presented over the course of the show's run. Costuming and makeup were likewise painstakingly recreated based on primary historical sources where available.
When an error was discovered, the effort was made to correct it whenever possible. This process is perhaps most noticeable in the evolution of a song featuring the four Hanoverian King Georges: lyrics in the original 2009 video incorrectly saying that George I had "died on the loo" were correctly reassigned to George II for the song's reprise at the show's 2011 BBC Prom concert.
Taking cues from what Deary describes as his "seriously subversive" attitude towards the mainstream British history education model meant that the show inevitably incorporated sociopolitical comment. Perhaps most explicitly, Scots-Jamaican nurse Mary Seacole was deliberately championed in both a sketch and later song as a forgotten heroine in the shadow of Florence Nightingale. The activities of African-American activists Harriet Tubman and Rosa Parks were also showcased, as was ex-slave boxer Bill Richmond. According to Norris, a desire to include more women's stories was hampered by the traditionally male-dominated viewpoint of historical records. The show did make an attempt to counteract this by giving showcase songs to the British women's suffrage movement and women's work on the British homefront during World War II, and wherever possible highlighting strong-willed, dynamic female figures, including Queen Victoria, Elizabeth I and Boudicca. Religious controversies, class divisions, the ethics of conquest, and labour conditions were likewise touched on.
The association with a proven and popular children's brand focusing on potentially sensitive subjects enabled the TV series to deflect any serious controversy regarding the same subjects, as they had demonstrably already been presented to children without any ill effects. Senior writer Steve Punt said that there were in fact very few complaints regarding the initial series' content, adding that "everyone was very relieved". The producers did consider some topics intrinsically unsuited for an irreverent comic treatment, as for instance the Holocaust or the harsher details of slavery, and avoided them accordingly. Norris has described her personal criteria for age suitability as whether she would be nervous watching it with a ten-year-old. While BBC executives in large part were willing to concede the requirements of reflecting historical realities, some topics, notably suicide, needed careful handling to avoid potentially negative impact on younger viewers. The show sometimes acknowledged particularly emotive subject matter (the World War I Christmas truce, for example) by following up the sketch not with a joke, but a more sombre elaboration of the less comedic details.
Production
The TV series used the Horrible Histories brand, logo and associated trademarks under licence from publisher Scholastic Books. It was produced for the BBC by LionTV and Citrus Television, with post-production being handled by Platform Post Production. Under series producer Norris and directors Brigstocke, Steve Connelly and Chloe Thomas, each series of thirteen episodes took approximately one year to produce. The process included several months of research into the historical facts, two to three months of writing, eight weeks of filming both on location and at London's Twickenham Studios, and three to four months of post-production.
At first the sketches were derived almost exclusively from the books, whose multimedia approach, consisting of short anecdotes interspersed with cartoons, diaries, newspaper articles and recipes, proved easily adaptable to the screen either as raw material or creative inspiration. In later series, as usable material from the books and other obvious sources began to run out, concepts were drawn from more standard historical texts under Jenner's supervision. He and fellow researchers read through many different studies and picked out suitably quirky, intriguing snippets, which were then pitched to the writers for development.
Inspiration for the music videos came from many different sources, and input from all members of the show's creative team was encouraged. With the exception of "A Gorgeous Georgian Lady", adapted by Deary from his book Gorgeous Georgians, all songs were original to the series. Once Jenner and Norris had finalised the subject matter and music genre, lyrics were commissioned from the writing team, usually Dave Cohen. These were rewritten as needed under Norris' supervision to ensure as much factual information as possible was included. Webb then composed and recorded each song's instrumental track at Noisegate Studios, hewing as closely as possible to the style of the genre or artist in question. The finished vocal and backing tracks were later returned to Noisegate for post-production by Webb and colleague Matt Katz.
The 2D animated sequences were directed by Tim Searle of Baby Cow Animation, based on Martin Brown's illustrations for the books. They were voiced by Jon Culshaw and Jess Robinson along with various regular cast members. Video game-styled sketches were achieved using a mix of 3D animation and live-action green-screen footage. Properties frequently were modified foodstuffs, with melted chocolate bars standing in for excrement and soup for vomit.
Each series debuted in the UK in April or May from 2009 to 2013, and on international channels including Canada's BBC Kids, the United States' Discovery Kids, Malaysia's NTV7, the Philippines' GMA Network, and Australia's ABC3. Six special episodes, comprising a mix of new and existing material around a single theme, were broadcast in the UK. "Horrible Christmas" (aired in 2010) was followed by a "Sport Special" (July 2012, to coincide with the 2012 London Olympic Games) and a "Scary Special" (autumn 2012, themed around Halloween). "Ridiculous Romance" (themed around Valentine's Day) aired in February 2014; the "Frightful First World War Special" aired later the same year, as part of the BBC's commemoration of the 100th anniversary of the outbreak of World War I.
In autumn 2011, the BBC edited footage from the show's summer Prom concert into an hour-long TV special ("Horrible Histories' Big Prom Party"), featuring specially shot linking sketches. In addition, standalone sketches hosted by Stephen Fry, as well as a special "Bob Hale Report", were produced as part of the 2012 Sport Relief benefit programme. In the same year, several sketches were commissioned as part of the BBC's live television coverage of the Diamond Jubilee of Elizabeth II, to be performed on Tower Bridge, but due to time constraints only one was aired.
The producers decided to cease full-time production after the fifth series, citing concerns around the increasing difficulty in finding suitable historical material. However, the possibility of further specials marking important historical or holiday milestones has been discussed.
In 2015, the BBC announced that the Horrible Histories concept would be revived in a new format, focusing on the life and times of a single historical figure per episode. The rebooted series was again developed by LionTV and will involve a largely all-new production team and cast, while still retaining Jenner as lead historical consultant and many of the original series's writers. In addition, original stars Farnaby and Howick will return in limited roles.
Cast
The cast members were recruited from sketch and character comedy, having previously had roles in Gavin & Stacey, Peep Show, The Thick of It and The Mighty Boosh TV series among others. Several of the writers and researchers also occasionally appeared in front of the camera, including Punt, Jenner, George Sawyer and Susie Donkin, while actors Mathew Baynton and Ben Willbond sometimes contributed to the writing. Laurence Rickard was recruited solely as a writer, but found himself part of both the senior writing staff and starring cast after creating the character of Bob Hale, whose extended, convoluted monologues proved impossible to hand over to anyone else.
Individual sketches and songs were cast by the production team, sometimes acting on input from the show's stable of performers themselves. While certain roles naturally lent themselves to a particular actor, Norris said that confidence in the entire cast's ability was such that the producers also experimented with casting against type. The demands of filming thirteen episodes' worth of material in the same timeframe as a standard six-episode sketch show, while coping with the many complex makeup and wardrobe changes required, resulted in casting also being partially dependent on the logistics of moving a performer from one character to another. Recurring characters were if at all possible played by the actor who had originated the part, leading to the development of several signature roles, as for example Baynton's Charles II, Jim Howick's Shouty Man, Rickard's Bob Hale, Willbond's Henry VIII, Martha Howe-Douglas's Elizabeth I, Simon Farnaby's Death and Sarah Hadland's Queen Victoria.
The performers were allowed to improvise provided that they maintained factual accuracy. Howick said that improvisation was actually often necessary due to the rapid-fire pace of filming, which left very little time to prepare for individual roles. On the other hand, both Rickard and Baynton suggest this enforced spontaneity may have ultimately worked to enhance the comedy, not least by preventing the jokes from becoming over-rehearsed.
Six performers (Baynton, Howick, Rickard, Willbond, Howe-Douglas and Farnaby) were credited as main or starring cast throughout the show's run; a seventh, Sarah Hadland, left after the second series but returned with an "also starring" credit for the fourth and fifth. The initial sextet appeared from Series 2 onwards as the standard face of the show at premieres and other press opportunities, and performed as a troupe for such peripheral events as the show's BBC Prom concert. They became a particularly close-knit group both personally and professionally. Eventually this led them to continue working together after Horrible Histories ceased full-time production, creating, writing and starring in the TV series Yonderland, feature film comedy Bill and TV series Ghosts.
The supporting cast varied considerably by series. Those performers with additional speaking parts are listed below:
Puppeteer John Eccleston, operates the puppet rat host, Rattus Rattus, whilst also supplying his voice. Scott Brooker performs additional puppetry. Jon Culshaw, Jess Robinson, and Dave Lamb provide various additional voice-overs and narration throughout the series.
The show has attracted several special guest stars. In the fourth series, Gatiss, Shearsmith and Pemberton of The League of Gentlemen joined the show, playing the panel of Hollywood producers for the "Movie Pitch" sketches. Shearsmith said, "Mark and I independently thought it was just a brilliant show that works on a number of levels ... There's not a weak link in the team here and it's an honour to be asked to be part of it". Other featured guests included:
Meera Syal (Series 1, Storyteller in "Twisted Fairytales")
Alexei Sayle (Series 2, Arabic healer, "Historical Hospital")
Tanni Grey-Thompson (Series 3, herself, field reporter for "HHTV Sport")
David Baddiel (Series 2 & 3, storyteller Vincenzo Larfoff, "Scary Stories")
Chris Addison (Series 4, two different "Historical Apprentice" candidates)
Amir Khan and Jermain Defoe (Series 4, as themselves in Sport Relief sketches)
Al Murray (Series 5, various roles, notably the drummer for the Smiths-inspired Charles Dickens music video)
Reception
Horrible Histories was immediately, and almost universally, greeted with critical enthusiasm. On its debut, Alice-Azania Jarvis of The Independent described the show as "fun, filthy and genuinely engaging, in a peer-to-peer way." Harry Venning in The Stage approved the "seriously funny, beautifully performed and endlessly inventive sketches" along with "plenty of crowd-pleasing fart and poo gags." By the second series, the show's cross-generational appeal was beginning to attract significant attention from adult media. Naomi West of The Daily Telegraph characterised the first series as "boundary-pushing", suggesting that "the bold decision to approach the series in the same way as an adult show has been the key to its success ... [it] delivers more laughs than most post-watershed comedies." James Delingpole in The Spectator likewise recommended the show to viewers of all ages, saying that "Even though there are vast quantities of entirely gratuitous fart, bottom and wee wee jokes, the cumulative effect—bizarrely—is one of dumbing up rather than down." Discussing the first two series in The Guardian, television writer Jesse Armstrong said that "Hit shows are very difficult to achieve. You need to have everything just right—that's what's so terrifying. But Horrible Histories has a great cast and brilliant writers. They're also blessed with great source material. The tone is perfect and it is done in a non-patronising, engaging way".
Clare Heal of the Daily Express, in her review of the third series, praised the show's "spot-on spoofs of modern telly" and agreed that "There's no particular target audience but pretty much anyone of any age will find something in there for them". Kerrie Mills of PopMatters rated the first three series 9/10, opining that the show "does also provide evidence, edgewise between the falling bodily fluids, of a sharp comic intelligence ... in fact, it might just be one of the most successful original comedy shows to appear in years." Stephen Kelly of The Guardian argued that the fourth series had definitively transcended its roots to become not just "the best show on children's television—it's one of the smartest comedies on TV", performed by an "astonishing cast ... so superb that even special guest stars such as Chris Addison can look slightly out of their depth." In an article discussing the League of Gentlemen troupe's appearance in the same series, the Radio Times''' Gareth McLean agreed that "despite nominally being a children's programme, Horrible Histories is one of the best sketch comedies on TV", adding that "ultimately, comedy performers relish [the] madcap, sometimes deliciously silly exuberance, which, thanks to the show's razorsharp writing, educates as well as entertains." Graeme Virtue of The Scotsman called the League's reunion a "coup" for the series: "While Gatiss's American accent was pretty duff, the bickering spark between the three Gentlemen remained."
Sarah Dempster of The Guardian said that "Four years into its ingenious 'making history look less crap' operation ... HH remains true to its aim, with meticulously harvested historical data + roaringly well-observed pop culture pastiches = seemingly infinite heritage lolz." Writing in The Independent, Grace Dent commended the cast in particular, saying that the show "has the distinct feel of a group of bright, young, erudite, writery-actory sparks having a tremendously good time." Venning of The Stage reiterated his praise of the show, adding that "it also has the courage to tackle potentially controversial events head on", specifically citing the song featuring the Civil Rights Movement activist Rosa Parks as retelling her story in a "clever, concise and accessible way without trivialising it." In 2016, Margaret Lyons of The New York Times praised the series as "deeply silly", "frequently hilarious", and, "very consistent".
Historical accuracy
Most criticism of the show revolves around the accuracy and presentation of its factual content. The TV series, like the books, has been used by educators as a classroom aid and was endorsed by UK Education Secretary Michael Gove as useful for spotlighting "neglected periods of history." However, writing after the final episode, Simon Hoggart in The Spectator noted that "There has been some whipped-up controversy about Horrible Histories", adding that "where the books make a rudimentary attempt to teach history as a series of interconnected events, the television show is basically gags, chiefly about defecation, gluttony, murder and torture. It's quite amusing, though whether it will pique an interest in the subject, or—as some say—merely encourage children to learn more about defecation, gluttony, murder and torture, we cannot know."
More specifically, in September 2014, responding to a complaint from the Nightingale Society, the BBC Trust determined that the show had breached editorial guidelines in the sketch highlighting the controversy surrounding Mary Seacole's role in nursing history. In this sketch, Florence Nightingale says that she rejected the Jamaican-born Seacole's application to Nightingale's Crimean nursing corps because it was open to "British girls" only. This was held to be imputing racially discriminatory motives to Nightingale—and thus implying them to be historical fact—without sufficient proof. In response, the BBC pulled the sketch from their website and announced it would be removed from future showings of the episode.
In a 20th-anniversary retrospective of the franchise in The Telegraph, David Horspool, the history editor of the Times Literary Supplement, defended the show's overall viewpoint, saying, "There's no particular reason why grown-up historians shouldn't like Horrible Histories too ... They simplify, and they have a definite point of view, but all historians are guilty of that to some degree." He further said that "Getting children interested in the past isn't necessarily easy, and Horrible Histories does it extremely effectively—and those who come to history because it's fun seem far more likely to stay with it in the long run." Writing for entertainment website DorkAdore, Anna Lowman added that "Terry Deary had the fine idea of getting kids into history by giving the facts a human face and a joke or two ... The producers of the CBBC show have perfectly transferred Deary's ethos to television."
The recut for BBC1 with Fry as host drew particular criticism as to whether its educational methods were suited to an adult demographic. History Today editor Paul Lay called the idea "frightening". Historian and Labour Party MP Tristram Hunt, while admitting that he had not yet actually seen the programme, voiced his concerns that the show's content was not "challenging and stimulating" enough for the BBC, adding that "For children, Horrible Histories is an exciting aid to engage with the guts and gore of the past, but there are more sophisticated, populist ways of getting people involved in history than this. I'm in favour of populism, but there has to be a bit of depth to it."
Other critics have taken a more lenient view. Historian and television presenter Dan Snow described the show's modus operandi as "one step above Blackadder, but that's fine ... it plays to stereotypes, but it's fantastic as entry-level history." Writing in The Independent, Tom Sutcliffe noted that "As a grown-up you might quibble with the fact that they don't always distinguish between things that genuinely are true and the things that people would like to be (sadly, there's no hard evidence that Aeschylus was brained by a tortoise dropped by an overflying eagle)", but added that "children and adults alike should enjoy the gleefully anachronistic way in which the information is presented." Dent in The Guardian, while conceding what she called the show's "frankly slapdash, dumbed-down approach to history", also argued that "in Horrible Histories there are always serious messages lurking amid the silliness."
Ratings
In its debut week of 15 June 2009, the show topped the UK children's TV viewing figures with 191,000 viewers. The first series reached a viewing peak of 50% of UK children aged 6–12, while the second was watched by 34% of UK children aged 6–12, or 1.6 million total. Throughout its run, the show routinely ranked at or near the top of the CBBC ratings, reaching a peak of 548,000 viewers for Episode 10 of Series 5.
Awards and nominations
Awards and nominations for Horrible Histories include several BAFTA Children's Awards, two British Comedy Awards and a Rose d'Or Award for Best Children's Programme. It is the first children's programme to win a British Comedy Award and four successive children's BAFTAs for Best Comedy. In 2013 the show was also named in a Radio Times poll of all-time greatest British children's TV series, and was ranked at No. 8 in a similar Top 50 list presented later the same year by Channel Five.
DVD and online releases
All five series of the original show, plus the "Scary (Halloween) Special", "Ridiculous Romance" & the "Frightful First World War Special" and "Horrible Christmas" have been released on Region 2 DVD by 2entertain for the BBC, both individually and as boxed sets. As of 2023, "Horrible Histories' Big Prom Party" & the "Sport Special" have yet to receive a home video release.
Each series, as well as the "Scary Special" and "Sport Special", are also available for download from the UK iTunes store. As of February 2014, all episodes from Series 1–3 were available for download to American audiences on Amazon.com "Instant Video" service.
Spin-offs
In 2011, a spinoff game show, Horrible Histories: Gory Games, was launched on CBBC. Likewise coproduced by Lion TV and Citrus, the show was co-hosted by Dave Lamb with puppet Rattus Rattus and includes cameos from many of the parent show's cast. As of 2013, the show had aired three full series. For summer 2011, the show was repackaged for adult Sunday-night audiences as Horrible Histories with Stephen Fry, a six-part "best of" compilation for BBC One. The show featured a selection of sketches and songs from the first two series chosen by the producers of the parent show, with Fry replacing the puppet rat as presenter.
2015 revival and specials
In 2015, the series returned with a new cast in a revised format, starring Jalaal Hartley, Tom Stourton and Jessica Ransom. Episodes centred around the life of one prominent historical figure played by an established comedy actor. In 2016 a seventh series began with just three specials before the full season in 2017. The three specials marked anniversaries through the year: 400 years since Shakespeare died, the BBCs 'Love to Read' campaign and 350 years since the Great Fire of London.
FilmsBill, a BBC comedy film based loosely around the early life of William Shakespeare, was released on 18 September 2015. Though not officially related to the series, the film reunited and starred the original core performers of Horrible Histories in starring roles.
Altitude Film Entertainment and Citrus Films produced a film adaptation directed by Dominic Brigstocke set in Roman Britain, titled Horrible Histories: The Movie – Rotten Romans''. It was released 26 July 2019. The original cast of the TV series were not involved, although members of the revival cast were. The film received mostly positive reviews, earning a 69% approval score on Rotten Tomatoes.
Notes
References
External links
"Yonderlanders: Celebrating the collective art of Mathew Baynton, Simon Farnaby, Martha Howe-Douglas, Jim Howick, Laurence Rickard, and Ben Willbond"
Interview with Greg Jenner
2020 Greg Jenner interview
2000s British children's television series
2000s British television sketch shows
2009 British television series debuts
2010s British children's television series
2010s British television sketch shows
2014 British television series endings
BBC children's television shows
BBC television sketch shows
British children's comedy television series
British children's education television series
British television shows based on children's books
British television shows featuring puppetry
British television series with live action and animation
CBBC original programming
Television series by BBC Studios
Children's sketch comedy
Depictions of Caligula on television
Depictions of Cleopatra on television
British English-language television shows
Horrible Histories
British surreal comedy television series
Television series by All3Media
Cultural depictions of Charles II of England
Cultural depictions of William Shakespeare
Cultural depictions of Philip II of Spain
Cultural depictions of Aristotle
Cultural depictions of Elagabalus
Cultural depictions of Guy Fawkes
Cultural depictions of Richard I of England
Depictions of Mark Antony on television
Depictions of Augustus on television
Cultural depictions of Charles I of England
Cultural depictions of James VI and I
Cultural depictions of Nicholas II of Russia
Cultural depictions of George II of Great Britain
Cultural depictions of Isaac Newton
Cultural depictions of Peter III of Russia
Cultural depictions of Francis I of France
Cultural depictions of Johannes Gutenberg
Cultural depictions of the Wright brothers
Television series about personifications of death
Cultural depictions of William the Conqueror
Cultural depictions of George III
Cultural depictions of James II of England
Cultural depictions of Ramesses II
Cultural depictions of Elizabeth I
Cultural depictions of Queen Victoria on television
Cultural depictions of Empress Matilda
Cultural depictions of Joan of Arc
Cultural depictions of Boudica
Cultural depictions of Mary Shelley
Depictions of Mary, Queen of Scots on television
Cultural depictions of George IV
Depictions of Nero on television
Cultural depictions of Winston Churchill
Cultural depictions of Prince Albert of Saxe-Coburg and Gotha
Cultural depictions of Horatio Nelson
Cultural depictions of Napoleon
Cultural depictions of Wilhelm II
Cultural depictions of Martin Luther
Cultural depictions of George V
Cultural depictions of Diogenes
Cultural depictions of Arthur Wellesley, 1st Duke of Wellington
Cultural depictions of Henry V of England
Cultural depictions of Pompey
Cultural depictions of Paul Revere
Cultural depictions of Henry VIII
Cultural depictions of Alexander the Great
Depictions of Julius Caesar on television
Cultural depictions of George I of Great Britain
Cultural depictions of Louis XVI
Cultural depictions of William Wallace
Cultural depictions of Lord Byron
Cultural depictions of Henry Ford
Cultural depictions of Mary I of England
Cultural depictions of Nell Gwyn
Cultural depictions of Florence Nightingale
Cultural depictions of Nefertari
Cultural depictions of Oliver Cromwell
Cultural depictions of Rosa Parks
Cultural depictions of Marie Antoinette
Cultural depictions of Lady Jane Grey
Cultural depictions of Richard III of England
Cultural depictions of Blackbeard
Cultural depictions of Marcus Licinius Crassus
Cultural depictions of Henry II of England | Horrible Histories (2009 TV series) | [
"Astronomy"
] | 7,839 | [
"Cultural depictions of Isaac Newton",
"Cultural depictions of astronomers"
] |
41,345,437 | https://en.wikipedia.org/wiki/Predictive%20intake%20modelling | Predictive intake modelling uses mathematical modelling strategies to estimate intake of food, personal care products, and their formulations.
Definition
Predictive intake modelling seeks to estimate intake of products and/or their constituents which may enter the body through various routes such as ingestion, inhalation and absorption.
Predictive intake modelling can be applied to determine trends in food consumption and product use for the purpose of extrapolation.
Applications
A predictive intake modelling approach is used to estimate voluntary food intake (VFI) by animals where their eating habits cannot be exactly measured. For humans, predictive intake modelling is used to make estimations of intake from foods, pesticides, cosmetics and inhalants as well as substances that can be contained in these like nutrients, functional ingredients, chemicals and contaminants.
Predictive intake modelling has applications in public health, risk assessment and exposure assessment, where estimating intake or exposure to different substances can influence the decision making process.
Predictive intake modelling strategies
Regression approach
The regression analysis approach is based on estimations through extrapolation or interpolation where there is a cause-and-effect relationship found by data fitting. These trends tend to be phenomenological.
Mechanistic modelling approach
A mechanistic modelling approach is one where a model is derived from basic theory. Examples of these include compartmental models which can be used to describe the circulation and concentration of airborne particles in a room or household for estimating intake of inhalants.
Population-based approach
A population-based approach tracks consumer intake from individual members of a sample population over time. Mathematical models are used to combine these habits and practices databases with separate databases on product or food formulation to estimate intake or exposure for the sample population. Moreover, survey weights may be applied to each subject in the study based on their age, demographic and location allowing the sample of subjects to correctly represent an entire population, and thus estimate intake for that population.
Probabilistic modelling approach
Probabilistic models are based on the Monte Carlo method where distributions of data from various sources are randomly sampled from to calculate percentile statistics. Such probabilistic techniques typically utilise product or consumption survey data from a sample population combined with distributions of substances that may be found within those foods or products. For example, The Food and Drug Administration (FDA) suggest that the estimation of intake of substances in food can be probabilistically conducted through food consumption surveys (NHANES/CSFII) from sample populations combined with distributions of substance concentration data to calculate the Estimated Daily Intake. The European Food Safety Authority (EFSA) funded the Monte Carlo Risk Assessment (MCRA) tool to estimate usual intake exposure distributions based on statistical models which utilise the EFSA Comprehensive Database, which contains detailed food consumption survey data. EFSA also funded Creme Global to develop a model and databases of European food consumption on which statistical models can be run to assess intake and exposure on a pan-European basis.
See also
Predictive modelling
Exposure science
Exposure Assessment
References
Mathematical modeling | Predictive intake modelling | [
"Mathematics"
] | 618 | [
"Applied mathematics",
"Mathematical modeling"
] |
41,346,435 | https://en.wikipedia.org/wiki/C9H6O6 | {{DISPLAYTITLE:C9H6O6}}
The molecular formula C9H6O6 may refer to:
Hemimellitic acid (benzene-1,2,3-tricarboxylic acid)
Trimellitic acid (benzene-1,2,4-tricarboxylic acid)
Trimesic acid (benzene-1,3,5-tricarboxylic acid)
Molecular formulas | C9H6O6 | [
"Physics",
"Chemistry"
] | 95 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
41,348,152 | https://en.wikipedia.org/wiki/FreeCast | FreeCast, Inc. is an American digital media distribution company headquartered in Orlando, Florida. The company offers streaming media accessible via web browsers.
History
FreeCast was founded in 2011 by William Mobley, who also serves as the CEO of the company. In its early years, FreeCast operated as a search engine for web video content, actively locating and categorizing a significant volume of new videos daily across 5000 categorized channels. Additionally, the company introduced a Facebook app that allowed users to watch video programming directly from their Facebook page.
Primary product of the company is Rabbit TV, which is a web-based virtual library of entertainment media created in collaboration with A. J. Khubani's company, Telebrands. In 2012, the company, in partnership with Telebrands, transformed its service into a physical device known as Rabbit TV. This product was subsequently sold through major U.S. retailers in the form of a USB stick, providing users with access to a web-based guide interface.
Rabbit TV functions by aggregating links to various digital media sources, including TV shows, news broadcasts, live sporting events, movies, music, and radio stations. Following the achievement of one million paid subscribers, FreeCast announced plans for further Rabbit TV development, including enhancements such as increased social media integration, compatibility with multiple devices, and the introduction of a la carte programming packages.
References
External links
Official website
Internet properties established in 2011
Companies based in Orlando, Florida
Video on demand services
Streaming television
Streaming media systems | FreeCast | [
"Technology"
] | 312 | [
"Streaming media systems",
"Telecommunications systems",
"Computer systems"
] |
41,348,307 | https://en.wikipedia.org/wiki/Cardy%20formula | In physics, the Cardy formula gives the entropy of a two-dimensional conformal field theory (CFT). In recent years, this formula has been especially useful in the calculation of the entropy of BTZ black holes and in checking the AdS/CFT correspondence and the holographic principle.
Using results by J. L. Cardy, the following entropy formula can be derived:
Here is the central charge, is the product of the total energy and radius of the system, and the shift of is related to the Casimir effect. These data emerge from the Virasoro algebra of this CFT. The proof of the above formula relies on modular invariance of a Euclidean CFT on the torus.
The Cardy formula is usually understood as counting the number of states of energy of a CFT quantized on a circle. To be precise, the microcanonical entropy (that is to say, the logarithm of the number of states in a shell of width ) is given by
in the limit . This formula can be turned into a rigorous bound.
In 2000, E. Verlinde extended this to certain strongly-coupled (n+1)-dimensional CFTs. The resulting Cardy–Verlinde formula was obtained by studying a radiation-dominated universe with the Friedmann–Lemaître–Robertson–Walker metric
where R is the radius of a n-dimensional sphere at time t. The radiation is represented by a (n+1)-dimensional CFT. The entropy of that CFT is then given by the formula
where Ec is the Casimir effect, and E the total energy. The above reduced formula gives the maximal entropy
when Ec=E, which is the Bekenstein bound. The Cardy–Verlinde formula was later shown by Kutasov and Larsen to be invalid for weakly interacting CFTs. In fact, since the entropy of higher dimensional (meaning n>1) CFTs is dependent on exactly marginal couplings, it is believed that a Cardy formula for the entropy is not achievable when n>1.
See also
BTZ black hole
AdS/CFT correspondence
Holographic principle
Conformal field theory
References
Quantum gravity
Conformal field theory | Cardy formula | [
"Physics"
] | 453 | [
"Quantum gravity",
"Unsolved problems in physics",
"Physics beyond the Standard Model"
] |
41,348,328 | https://en.wikipedia.org/wiki/Girish%20Sant | Girish Sant was a noted energy analyst held in high esteem as an energy policy commentator from India. He co-founded the non-governmental organisation Prayas in Pune, India. His analytical inputs helped shape India's energy policy over the decades of the 1990s and 2000s. He was considered an effective team builder and mentored several energy researchers and activists.
Formative years
Girish spent his childhood in Thane, and joined IIT Mumbai in 1982 for BTech in Chemical engineering. After completing BTech in 1986, he also completed Masters in Energy Systems in 1988 from IIT.
Girish's years in IIT Mumbai brought out his leadership, team building and mountaineering skills. He was an accomplished mountaineer and rock climber, and made important rock climbing ascents with fellow mountaineers including the first ever climb of the Konkan Kada. He was an active member of the IIT Mountaineering Club and also the Institute Mountaineering Secretary during 1985–86.
During his stay at IIT, particularly during his Masters study, Girish started thinking about full-time work in a field of direct social relevance along with friends – Ajit Gaunekar and Aniruddha Ketkar. He started interacting with Subodh Wagle, then research fellow at Center for Technology Alternatives for Rural Areas, with whom he explored appropriate technologies, rural society and related developmental paradigms.
Entry to the energy sector
By 1988, when Girish completed Masters in energy systems, he developed a clear idea that he wanted to work for the betterment of society and not for personal prosperity, using his professional skills on issues related to energy. He relocated to Pune and initially worked as a lecturer in an engineering college, undertook sporadic energy audit and industrial consultancy projects and then worked at Systems Research Institute. This was a period of exploration along with other like-minded friends – Shripad Dharmadhikary, Sanjeevani and Vinay Kulkarni – that brought him closer to people's movements, particularly the NBA.
During this period he came across the Development Focused End Use Oriented (DEFENDUS) approach to power sector planning developed by Prof. Amulya Kumar N. Reddy. Subsequent interactions with Prof. Reddy shaped his thinking and work in the energy sector in the early period. By this time, Girish started working with Shantanu Dixit who continued to be his colleague for the rest of his life. Analytical motivation from DEFENDUS, along with the support of friends and a scholarship from Dr. Ashok Gadgil, led to his first major work on development of a least cost plan for Maharashtra. Development of the least cost plan, its dissemination to various quarters and subsequent responses from power sector actors and activists contributed to his understanding of the energy sector and the broader political economy and institutional dynamics of the sector in India.
This was also the time of reforms for the power sector in India, which witnessed entry of projects such as Dabhol Power Company built by Enron. Girish, Subodh and Shantanu were able to see the long term implications of such projects and reforms for the Indian power sector and economy at large. Realising the need to de-mystify such complex projects and to highlight their implications for people of the state and the country, they worked relentlessly to unravel the complex power purchase agreement of Enron and communicate the devastating impact of the project to activists and the wider community. These early experiences shaped his vision for the power sector as well as his strategic and substantive approach to work in the energy sector.
Formation of prayas, institution building and approach to policy analysis
In 1994, his work in the energy sector evolved into the formation of Prayas, Initiatives in Health, Energy, Learning and Parenthood along with Sanjeevani and Vinay Kulkarni.
Girish believed in and ensured teamwork and democratic working of the group. Under his leadership, the Energy Group within Prayas (PEG), which started with three people, expanded to a team of over 15 researchers from a variety of backgrounds. Girish had the ability to connect with a wide range of professionals, which attracted senior researchers as well as young engineers to join Prayas.
Girish was particular about encouraging intellectual and substantive growth of colleagues, and supported new initiatives in the form of Resources and Livelihoods group of Prayas as well as academic interests of young researchers. Girish paid meticulous attention to the internal processes within Prayas and ensured that proper procedures were followed. Many peers and friends of Girish consider his institution building abilities as important a contribution and achievement as his substantive work in the energy sector. Girish assisted the likes of Sucheta Dalal, then a columnist in the Times of India, in understanding the controversial Dabhol power project and the Enron India scam that they unearthed.
Girish emphasised the need to be agile and to undertake strategic interventions in the sector. High quality and in-depth analysis, comprehensive approach, and prioritising interests of disadvantaged sections became the hallmark of his work and he successfully cultivated these principles across PEG. He believed that improving governance in infrastructure sectors like energy has the dual advantage of improving lives of the poor as well as saving public money that can then be spent on other services such as education. He successfully motivated and actively supported many young researchers to take up the task of policy advocacy in the energy sector based on public interest analysis.
In spite of several accomplishments and achieving an important stature in the energy sector in India, Girish remained humble and self-effacing, as is reflected in many of the tributes on his memorial webpage and in the Smriti Grantha (or Collection of Memoirs). He was mild mannered and soft-spoken, even when trying to convince someone holding a contrary opinion. This quality endeared him to many in the sector resulting in increased impact.
Interventions in the electricity sector
Girish was known in the energy sector for his use of high quality analysis to expose inadequacies of conventional planning and projects that result out of such a process. Under his guidance, PEG undertook techno-economic analysis of three large hydro-electric projects, Sardar Sarovar and Maheshwar in India and Bujagali in Uganda. The group analysed Sardar Sarovar and Maheshwar projects and highlighted inefficiencies therein, proposing several techno-economically feasible and socially desirable alternatives. Analysis of Bujagali Hydroelectric Power Station brought out inflated capital costs and one-sided nature of the power purchase agreement and led to renegotiation of the contract.
The wave of independent power producers in the 1990s was followed by State Electricity Board (SEB) reforms supported by the World Bank and Asian Development Bank, starting from Orissa in 1996. Under these reforms unbundling the SEB into generation, transmission and distribution companies, setting up a regulatory commission and gradually privatising the distribution was presented as the solution to all problems in power sector. PEG was the first to prepare a public interest critique of the Orissa model of reforms in 1998 and the role of Multi-lateral Development Banks, arguing that democratising governance is the key to addressing the power sector crisis, rather than focusing only on infusing capital or changing ownership.
PEG realised that the fight against unjust, inefficient projects needs to be started at the macro-level planning stage itself. Experience of disseminating least cost plan and struggle against Enron project, highlighted the influence of political economy on decision making and underscored the need for improving governance through enhanced transparency, accountability and participation (TAP) in the energy sector decision making. These insights have since guided the group's work in the energy sector and led to the group undertaking early interventions in improving the newly emerging independent regulatory commissions. Girish provided strategic guidance on the initial idea of bringing together a transnational network of civil society groups, called the Electricity Governance Initiative, that would work together to advance the principles of transparent, inclusive and accountable governance of electricity.
Girish was keen that analysis is followed by actual interventions aimed at pro-people changes. Accordingly, PEG actively engaged with several state as well as central regulatory commissions, with the aim of making regulatory process more transparent, accountable, participatory and helped serve the public interest more effectively. Subsequent to enactment of Electricity Act 2003, PEG was actively involved in giving inputs to national policies such as National Electricity Policy, Tariff Policy and Competitive Bidding Guidelines. This analysis of the Indian power sector and its role in the regulatory process was acknowledged by many in the sector.
Work beyond the electricity sector
Since 2006, Girish focused more on macro issues of resource availability, utilisation, and growing importance of global climate debate on India's energy policy. In 2009, he co-authored a report, 'An Overview of India's Energy Trends', highlighting important differences in energy production and consumption trends of India, US, European Union and China. Based on this work, he was invited to make presentations at high level meetings at COP15 at Copenhagen and at The Center for Clean Air Policy, Washington, D.C. He was India's representative at a UN workshop on non-Annex 1 NAMAs.
Subsequently, he was one of India's representatives in the BASIC Expert Group (an informal energy expert group formed by BASIC governments) that worked towards developing greater understanding of energy use in BASIC countries and for evolving common approach to climate negotiation. All these efforts and analysis contributed to strengthening India's position in the global discourse on climate change and energy, and also helped shape the domestic policy discourse.
On the domestic front, while welcoming the investment in renewable energy (RE), Girish suggested measures to improve effectiveness and equity in RE expansion. He was instrumental in making a case for setting up a National Wind Energy Mission, which is scheduled to begin in 2014.
Search for innovative solutions to vexed problems was another characteristic of Girish. This search led to a unique and novel concept for improving efficiency of commonly used domestic appliances. Though Girish and several other researchers had pointed out that energy efficiency of commonly used domestic appliances is very poor and using most efficient appliances instead of these inefficient appliances will lead to savings of thousands of MWs, a workable large scale solution to achieve this transformation was elusive. Girish, along with colleagues at Prayas, developed a concept called 'Super-Efficient Equipment Program – SEEP' under which nominal incentives are provided to appliance manufacturers to bring super-efficient equipment into the market. He successfully convinced Government of India and Planning Commission officials of the benefits of implementing such a program. Under this program, which will be launched in 2014 as part of the 12th Five Year Plan, it is expected that over five million 'super-efficient' fans, which consume half the electricity of normal fans, will be sold in the market. This approach is also being adopted at the global level under the auspices of the Clean Energy Ministerial.
Girish was also part of several official committees, such as Planning Commission's working groups for 11th and 12th five-year plans, Planning Commission's Steering Committee on Energy, the Supreme Court appointed Committee on Solid Waste Disposal, and Planning Commission's Expert Group on Low Carbon Strategies for Inclusive Growth.
Death
Girish died on 2 February 2012 in New Delhi due to cardiac arrest.
A committee consisting of people from within and outside Prayas was formed to manage activities organised in Girish's memory and "to further his work of independent analysis and advocacy to promote public interest issues in the energy sector". These activities include an annual memorial lecture organised in Pune and a fellowship for young researchers pursuing public interest research and advocacy.
Membership in policy related committees
Member, BASIC Expert Group (2011–12)
Convener Transport Working Group, of The Expert Group appointed by The Planning Commission (India) in 2010, to work out the 'Low Carbon Strategy for Inclusive Growth'
Member, World Bank Expert Committee to review West Bengal Power Sector Reforms (2008)
Member, 'Working Group on Power' for formulation of XIth five-year plan for the National Planning Commission (India) (2006–07)
Member, Expert Group, convened by Secretary of Power (Government of India) to seek "radical" policy suggestions (2006)
Member Expert Group on "Financing access to basic utilities for all" formed by the Friedrich Ebert Foundation in co-operation with the Financing for Development Office, June 2006.
Member, Expert Committee appointed by The Supreme Court of India for evaluating 'Waste to Energy projects from Municipal Solid Waste', appointed through Ministry of Non-Conventional Energy Sources (2005–06)
Member, Central Advisory Committee of Central Electricity Regulatory Commission (India), since 1998 till 2010
Member, State Advisory Committee of Maharashtra Electricity Regulatory Commission, since 1999 till 2010
Member, 'Consultative Group on Power & Energy' of Planning Commission (India) for review of energy sector performance in the Xth plan
Member, Advisory Committee, ADB Policy Research Network to strengthen policy reforms – Infrastructure Development for Poverty Reduction: Priorities, Constraints and Strategies (2004–05)
Member, Western Regional Energy Committee Confederation of Indian Industries (CII) (2003 and 2004)
Member Advisory Committee, Distribution Reforms Upgrade Management (DRUM) program of Government of India and USAID (2003)
Member, Study Group on Benefits of Sardar Sarovar Dam Project, Government of Maharashtra (2001)
Member, Task Force to review Narmada Dams, Government of M.P. (1998)
Member, International team of civil society to review status of rehabilitation of project affected persons at by Coal mines and Thermal plants at Singrauli (UP) (1995)
Recognition
Dr. T. N. Khoshoo Memorial Award in 'Conservation, Environment and Development' for year 2010, – Ashoka Trust for Research in Ecology and the Environment (Bangalore)
'Best Energy Alumni' – Energy Department, IIT Bombay (2008).
'Life Time Achievement – Encouragement Award' – Workers' and Engineers' union of Power utility in Maharashtra (2003), which he accepted on behalf of Prayas (energy group)
As a student, received citation for 'Exceptional Contribution Award' for enhancing Mountaineering activity at IIT Bombay.
'Annual Girish Sant Memorial Lecture' – IIT Bombay
Dedication of the book "Churning the Earth"
References
Businesspeople from Maharashtra
IIT Bombay alumni
Energy engineers
1966 births
2012 deaths
People from Thane
Indian environmentalists | Girish Sant | [
"Engineering"
] | 2,916 | [
"Energy engineering",
"Energy engineers"
] |
41,348,442 | https://en.wikipedia.org/wiki/Windows%20Hardware%20Error%20Architecture | Windows Hardware Error Architecture (WHEA) is an operating system hardware error handling mechanism introduced with Windows Vista SP1 and Windows Server 2008 as a successor to Machine Check Architecture (MCA) on previous versions of Windows. The architecture consists of several software components that interact with the hardware and firmware of a given platform to handle and notify regarding hardware error conditions. Collectively, these components provide: a generic means of discovering errors, a common error report format for those errors, a way of preserving error records, and an error event model based up on Event Tracing for Windows (ETW).
WHEA "builds on the PCI Express Advanced Reporting to provide more detailed information about system errors and a common reporting structure."
WHEA allows third-party software to interact with the operating system and react to certain hardware events. For example, when a new CPU is added to a running system—a Windows Server feature known as Dynamic Hardware Partitioning—the hardware error component stack is notified that a new processor was installed.
In contrast, Linux supports the ACPI Platform Error Interface (APEI) which is introduced in ACPI 5.0.
See also
Machine-check exception (MCE)
Reliability, availability and serviceability (RAS)
RAMS (reliability, availability, maintainability and safety)
High availability (HA)
Blue screen of death
References
Windows components
Windows Vista
Windows Server 2008
Computer errors | Windows Hardware Error Architecture | [
"Technology"
] | 278 | [
"Computer errors"
] |
41,349,488 | https://en.wikipedia.org/wiki/Tienstra%20formula | The Tienstra formula is used to solve the resection problem in surveying, by which the location of a given point is determined by observations of angles to known landmarks from the unknown point.
Author
(1895-1951) was a professor of the Delft university of Technology where he taught the use of barycentric coordinates in solving the resection problem. It seems most probable that his name became attached to the procedure for this reason, though when, and by whom, the formula was first proposed is unknown.
Method
The resection problem consists in finding the location of an observer by measuring the angles subtended by lines of sight from the observer to three known points. Tienstra’s formula provides the most compact and elegant solution to this problem.
Where:
References
Further reading
Ansermet A (1910) "Eine Auflösung des Rückwärtseinschneidens". Zeitschrift des Vereins Schweiz. Konkordatsgeometer, Jahrgang 8, pp. 88–91
External links
3-Point Resection Solver Using Tienstra's Method
Surveying
Euclidean plane geometry | Tienstra formula | [
"Mathematics",
"Engineering"
] | 233 | [
"Surveying",
"Planes (geometry)",
"Euclidean plane geometry",
"Civil engineering"
] |
41,351,260 | https://en.wikipedia.org/wiki/Federal%20Commission%20for%20the%20Protection%20against%20Sanitary%20Risk | The Federal Commission for Protection against Health Risks (in Spanish, Comisión Federal para la Protección contra Riesgos Sanitarios, Cofepris) is a regulatory body of the Mexican government. It is a decentralized organ of (and supervised by) the Mexican Secretariat of Health, and is responsible for regulating a variety of health related topics in Mexico, including food safety, pharmaceutical drugs, medical devices, organ transplants, and environmental protection.
References
See also
Food and Drug Administration (Similar organization in the United States)
Health Canada (Similar organization in Canada)
Medical and health organizations based in Mexico
National agencies for drug regulation | Federal Commission for the Protection against Sanitary Risk | [
"Chemistry"
] | 131 | [
"National agencies for drug regulation",
"Drug safety"
] |
41,351,364 | https://en.wikipedia.org/wiki/Flotation%20of%20flexible%20objects | Flotation of flexible objects is a phenomenon in which the bending of a flexible material allows an object to displace a greater amount of fluid than if it were completely rigid. This ability to displace more fluid translates directly into an ability to support greater loads, giving the flexible structure an advantage over a similarly rigid one. Inspiration to study the effects of elasticity are taken from nature, where plants, such as black pepper, and animals living at the water surface have evolved to take advantage of the load-bearing benefits elasticity imparts.
History
In his work "On Floating Bodies", Archimedes famously stated:
While this basic idea carried enormous weight and has come to form the basis of understanding why objects float, it is best applied for objects with a characteristic length scale greater than the capillary length. What Archimedes had failed to predict was the influence of surface tension and its impact at small length scales.
More recent works, such as that of Keller, have extended these principles by considering the role of surface tension forces on partially submerged bodies. Keller, for instance, demonstrated analytically that the weight of water displaced by a meniscus is equal to the vertical component of the surface tension force.
Nonetheless, the role of flexibility and its impact on an object's load-bearing potential is one that did receive attention until the mid-2000s and onward. In an initial study, Vella studied the load supported by a raft composed of thin, rigid strips. Specifically, he compared the case of floating individual strips to floating an aggregation of strips, wherein the aggregate structure causes portions of the meniscus (and hence, resulting surface tension force) to disappear. By extending his analysis to consider a similar system composed of thin strips of some finite bending stiffness, he found that this later case in fact was able support a greater load.
A well known work in the area of surface tension aided flotation was the analysis of water strider locomotion along the surface of water. Using the idea of flexible structures, Ji et al. re-examined this problem by considering the compliance of a water strider leg. By modeling the leg as a compliant structure that deforms at the water surface (rather than pierce it), Ji was able to ascertain what added benefit this flexibility has in supporting the insect. Other studies on the water strider have examined the ways in which flexibility can affect wetting properties of the leg.
Another track of research has been to investigate how exactly the interaction between liquid and a compliant object leads to the resulting deformation. In one example, such analysis has been extended to explain the difficulty in submerging hairs in a fluid. These works focus on behavior near the contact line, and consider what role non-linear effects such as slippage play.
Physical explanation of phenomena
In a liquid solution, any given liquid molecule experience strong cohesive forces from neighboring molecules. While these forces are balanced in the bulk, molecules at the surface of the solution are surrounded on one side by water molecules and on the other side by gas molecules. The resulting imbalance of cohesive forces along the surface results in a net "pull" toward the bulk, giving rise to the phenomena of surface tension.
When a hydrophobic object of weight is placed on the surface of water, its weight begins deforming the water line. The hydrophobic nature of the object means that the water will attempt to minimize contact due to an unfavorable energy tradeoff associated with wetting. As a result, surface tension attempts to pull back on the water line in order to minimize contact with the hydrophobic object and retain a lowest energy state. This action by the surface to pull back on the depressed water interface is the source of a capillary force, which acts tangentially along the contact line and thereby gives rise to a component in the vertical direction. An attempt to further depress the object is resisted by this capillary force until the contact line reaches a vertical position located about two capillary lengths below the undisturbed water line. Once this occurs, the meniscus collapses and the object sinks.
The more fluid a floating object is able to displace, the greater the load it is able to bear. As a result, the ultimate payoff of flexibility is in determining whether or not a bent configuration results in an increased volume of displaced water. As a flexible object bends, it penetrates further into the water and increases the total fluid displaced above it. However, this bending action necessarily forces the cross-section at the water line to decrease, narrowing the column of displaced water above the object. Thus, whether or not bending is advantageous is ultimately given by a tradeoff of these factors.
Mathematical model: flotation of hinged plates
Two rigid plates connected by a torsional spring
The following analysis is taken largely from the work of Burton and Bush, and offers some mathematical insight into the role that flexibility plays in improving load-bearing characteristics of floating objects.
Consider two plates of infinite width, thickness , and length that are connected by a torsional spring with spring constant per unit width . Furthermore, let be the angle between a plate and the horizontal, and the from where the meniscus meets the plate to the horizontal. The distance from the undisturbed water line to the plate's outer edge is . The density of water is , the density of air is considered negligible, and the plate density, , shall be varied. All systems naturally assume a configuration that minimizes total energy. Thus, the goal of this analysis is to identify the configurations (i.e., values of and ) that result in a stable equilibrium for a given value of .
For a total system energy of , it is natural to distinguish sub-components:
: Work done on the system
: System potential energy
In defining , there are several associated components:
is the work done on the interface by hydrostatic pressure
is the work done on the plates by hydrostatic pressure
is the work done on the plates by gravitational force
is the work done on the plates by surface tension forces
Similarly, the system potential energy, , is taken to be composed of two terms:
is the surface energy of the water/air interface
is the energy stored in the torsional spring and is equal to
There are two ways in which the system energy can change by an incremental amount. The first is a translation of the center of mass of the plates by some distance . The second is an incremental change, in the hinge angle. Such a change will induce a new moment.
As mentioned, the system will seek the orientation that minimizes in order to find point of stable equilibrium. Writing out these terms more explicitly:
Here, is the equation air/water interface, is the incremental displacement of the interface, and is the surface tension of water.
For a given value of , stable equilibrium configurations are identified as being those values of and that satisfy
Taken in a different light, these conditions can be seen as identifying and that result in zero net force and zero net torque for a given .
Analytical results for maximum load
Defining non-dimensional plate length , non-dimensional plate edge depth , and non-dimensional load , Burton and Bush derived the following analytical results:
The equations for and give the configuration parameters that give the maximum value of . For further insight, it is helpful to examine various regimes of the non-dimensional plate length, .
Case 1: Small scale β << H
When the characteristic plate length is much smaller than the characteristic plate edge depth, the effects of gravity, surface tension, and spring energy become dominant. In this limiting case, it turns out that flexibility does not improve load-bearing capabilities of the plates; indeed, the optimal configuration is a flat plate. Since the plate length is so much smaller than the displacement from the undisturbed water line, the extra fluid displaced by bending a rigid plate is outweighed by the loss of fluid in the column above the plate.
Case 2: Mid scale β ~ H
In this regime, flexibility may or may not improve load-bearing capabilities of the plates. The two characteristics lengths are of comparable dimension, so particular values for each determine whether or not additional fluid displaced through bending exceeds fluid lost through the narrowing of the column.
Case 3: Large scale β >> H
In this regime, the benefit of flexibility is most pronounced. The characteristic plate length is significantly longer than the characteristic depth to which the plate is submerged beneath the water line. As a result, the narrowing column above the plate is negligible, which the additional displacement of water due to bending is significant.
Extensions to continuously deformable body
To relate this mathematical to physical systems, the above analysis can be extended to continuously deformable bodies. Generalizing the equations of the two plate system allows one to write a corresponding set of equations for the case of a continuously deformable plate. This continuously deformable plate is composed of sub-plates, where similar force and torque equilibrium conditions described before must be satisfied for each sub-plate. Such analysis reveals that for a highly compliant 2D structure with a characteristic length much greater than the capillary length, the shape bearing the highest load is a perfect semi-circle. As stiffness increases, the semi-circle is deformed to shapes with lower curvature.
This initial look at continuously deformable bodies represents an initial stab into a very complicated problem. With the groundwork laid here in this analysis, it is likely that future works will implement this general ideology in a finite element approach. Doing so will allow much closer simulation of real world phenomena and will aid in determining how effects of elasticity can aid in the design of robots, instruments, and other devices that operate along the water line.
Examples in nature
Ants
Several species of ants including fire ants, formica and red imported fire ant, have developed adaptation to survive floods that threaten the colony. While individual fire ants are hydrophobic and flounder at the waters surface, large groups of ants can link together to form a temporary living clump, known as raft, and float along the waterline for as many as 12 days until reaching dry land. These clumps can include as many as 100,000 individual ants while the queen and larvae are evacuated from the flooding colony sitting upon this living raft. Ants clumped in this way will recognize different fluid flow conditions and adapt their behavior accordingly to preserve the raft's stability.
The importance of flexibility in this self-assembled ant raft is several fold. The extra weight-bearing that flexibility imparts is vital as hungry fish will swim along the underside of the raft and eat at many of the members. Furthermore, as waves travel along the water surface, the ant raft's flexibility allows it to effectively "roll" with the wave and minimize disturbances it would otherwise cause for a similar but rigid structure.
Aquatic vegetation
Among aquatic vegetation, the lily pad is perhaps the most recognizable, commonly associated with ponds and lakes. Their flexibility allows for increased loads, enabling them to support animals, such as frogs, many times their own weight.
Some aquatic flowers, such as the daisy Bellis perennis, use compliance as a survival mechanism. Such flowers have roots that extend down to the underlying soil, anchoring the flower to the surface of the water. When flooding occurs, the petals pull inward and deform the water line, shielding the genetic material in the core. Some flowers are even known to completely close up into a shell in this fashion, trapping air inside.
References
Fluid dynamics
Concepts in physics | Flotation of flexible objects | [
"Physics",
"Chemistry",
"Engineering"
] | 2,342 | [
"Piping",
"Chemical engineering",
"nan",
"Fluid dynamics"
] |
41,351,700 | https://en.wikipedia.org/wiki/Weak%20evolutionarily%20stable%20strategy | A weak evolutionarily stable strategy (WESS) is a more broad form of evolutionarily stable strategy (ESS). Like ESS, a WESS is able to defend against an invading "mutant" strategy. This means the WESS cannot be entirely eliminated from the population.
The definition of WESS is similar to ESS. Any strategy s is a weakly evolutionarily stable strategy (WESS) if for any strategy s*≠s:
(i) u(s, s) > u(s*, s) or
(ii) u(s, s) = u(s*, s) and u(s, s*) ≥ u(s*, s*).
One example of WESS, in a prisoner's dilemma, is Tit-for-tat (a strategy that cooperates in the first interaction and then reciprocates the other player's action from the previous turn in all other iterations).
References
Evolutionary game theory | Weak evolutionarily stable strategy | [
"Mathematics"
] | 208 | [
"Game theory",
"Evolutionary game theory"
] |
41,351,768 | https://en.wikipedia.org/wiki/Imidoyl%20chloride | Imidoyl chlorides are organic compounds that contain the functional group RC(NR')Cl. A double bond exist between the R'N and the carbon centre. These compounds are analogues of acyl chloride. Imidoyl chlorides tend to be highly reactive and are more commonly found as intermediates in a wide variety of synthetic procedures. Such procedures include Gattermann aldehyde synthesis, Houben-Hoesch ketone synthesis, and the Beckmann rearrangement. Their chemistry is related to that of enamines and their tautomers when the α hydrogen is next to the C=N bond. Many chlorinated N-heterocycles are formally imidoyl chlorides, e.g. 2-chloropyridine, 2, 4, and 6-chloropyrimidines.
Synthesis and properties
Imidoyl halides are synthesized by combining amides and halogenating agents. The structure of the carboxylic acid amides plays a role in the outcome of the synthesis. Imidoyl chloride can be prepared by treating a monosubstituted carboxylic acid amide with phosgene.
RC(O)NHR’ + COCl2 → RC(NR’)Cl + HCl + CO2
Thionyl chloride is also used.
Imidoyl chlorides are generally colorless liquids or low-melting solids that are sensitive to both heat and especially moisture. In their IR spectra these compounds exhibit a characteristic νC=N band near 1650–1689 cm−1. Although both the syn and anti configurations are possible, most imidoyl chlorides adopt the anti configuration.
Reactivity
Imidoyl chlorides react readily with water, hydrogen sulfide, amines, and hydrogen halides. Treating imidoyl chlorides with water forms the corresponding amide:
RC(NR’)Cl + H2O → RCONHR’ + HCl
Aliphatic imidoyl chlorides are more sensitive toward hydrolysis than aryl derivatives. Electron-withdrawing substituents decrease the reaction rate. Imidoyl chlorides react with hydrogen sulfide to produce thioamides:
RC(NR’)Cl + H2S → RC(S)NHR’ + HCl
When amines are treated with imidoyl chlorides, amidines are obtained.
RC(NR’)Cl + 2R”NH2 → RC(NR’)NHR” + R”NH3Cl
When R' ≠ R", two isomers are possible.
Upon heating, imidoyl chlorides also undergo dehydrohalogenation to form nitriles:
RC(NR’)Cl → RC≡N + R’Cl
Treatment of imidoyl chloride with hydrogen halides, such as HCl, forms the corresponding iminium chloride cations:
RC(NR’)Cl + HCl → [RC(NHR’)Cl]+Cl−
Applications
Imidoyl chlorides are useful intermediates in the syntheses of several compounds, including imidates, thioimidates, amidines, and imidoyl cyanides. Most of these syntheses involve replacing the chloride with alcohols, thiols, amines, and cyanates, respectively. Imidoyl chlorides can also undergo Friedel-Crafts reactions to install an imine groups on aromatic substrates. If the nitrogen of the imidoyl chloride has two substituents, the resulting chloroiminium ion is vulnerable to attack by aromatic rings without the need for a Lewis acid to remove the chloride first. This reaction is called the Vilsmeier–Haack reaction, and the chloroiminium ion is referred to as the Vilsmeier reagent. After attaching the iminium ion to the ring, the functional group can later be hydrolyzed to a carbonyl for further modification. The Vilsmeier-Haack reaction can be a useful technique to add functional groups to an aromatic ring if the ring contains electron-withdrawing groups, which make using the alternative Friedel-Crafts reaction difficult.
Imidoyl chlorides can be easily halogenated at the α carbon position. By treating imidoyl chlorides with hydrogen halide, will cause all α hydrogens to be replaced with the halide. This method can be an effective way to halogenate many substances. Imidoyl chlorides can also be used to form peptide bonds by first creating amidines and then allowing them to be hydrolyzed to the amide. This approach may prove to be a useful route to synthesizing synthetic proteins.
Imidoyl chlorides can be difficult to handle. Imidoyl chlorides react readily with water, which makes any attempt to isolate and store them for long periods of time difficult. Further, imidoyl chlorides tend to undergo self-condensation at higher temperatures if the imidoyl chloride has an α CH group. At even higher temperatures, the chlorine of the imidoyl chloride tends to be eliminated, leaving the nitrile. Because of these complications, imidoyl chlorides are typically prepared and used immediately. More stable intermediates are being sought, with substances such as imidoylbenzotriazoles being suggested.
References
Functional groups
Organochlorides | Imidoyl chloride | [
"Chemistry"
] | 1,092 | [
"Functional groups"
] |
52,916,384 | https://en.wikipedia.org/wiki/Ion%20interaction%20chromatography | Ion interaction chromatography (ion-pair chromatography) is a laboratory technique for separating ions with chromatography. In this technique ions are mixed with ion pairing reagents (IPR). The analyte combines with its reciprocal ion in the IPR, this corresponds to retention time. Often organic salts are selected to pair with solute(s). The formation of this pair affects the interaction of the pair with the mobile phase and the stationary phase.
See also
Ion association
Intimate ion pair
References
Chromatography | Ion interaction chromatography | [
"Chemistry"
] | 112 | [
"Chromatography",
"Separation processes",
"Analytical chemistry stubs"
] |
52,918,006 | https://en.wikipedia.org/wiki/IEEE%20Computer%20Science%20and%20Engineering%20Undergraduate%20Teaching%20Award | The IEEE Computer Science & Undergraduate Teaching Award is a Technical Field Award of the IEEE that was established by the IEEE Computer Society in 1999. It is presented for outstanding contributions to undergraduate computer science education through teaching and service.
The award nomination requires a minimum of 3 endorsements.
Recipients of this award receive a certificate, and honorarium.
Recipients
The recipients of the IEEE Computer Science & Engineering Undergraduate Teaching Award include the following people:
2017: Sven Koenig
2016: Mark Sherriff
2015: Henry C.B. Chan
2014: Elizabeth Gerber
2013: Robert J. Fornaro
2012: Mark Guzdial
2011: Benjamin Hescott
2010: No Award
2009: Judy Robertson
2008: Elizabeth L. Burd
2007: Darrin M. Hanna
2006: No Award
2005: No Award
2004: No Award
2003: Sally Fincher
2002: Alan Clements
2001: Steven S. Skiena, and David G. Meyer
2000: No Award
1999: Joseph L. Zachary, and Bruce W. Weide and Timothy J. Long
References
Computer Science and Engineering Undergraduate Teaching Award
Computer science education | IEEE Computer Science and Engineering Undergraduate Teaching Award | [
"Technology"
] | 220 | [
"Science and technology awards",
"Computer science education",
"Computer science",
"Science award stubs"
] |
52,918,493 | https://en.wikipedia.org/wiki/Kim%20Il%20Sung%20and%20Kim%20Jong%20Il%20badges | Kim Il Sung and Kim Jong Il badges are lapel pins with portraits depicting either one or both of the Eternal Leaders of North Korea, Kim Il Sung and Kim Jong Il. The badges have been common since the late 1960s, and are produced by the Mansudae Art Studio. There are more than 20 different designs, some of which are more common than others. Common examples include red flag-shaped pins depicting either Eternal President Kim Il Sung or Eternal General Secretary Kim Jong Il, smaller circular pins with the same portraits on white backgrounds (often with silver or gold edging), and larger flag-shaped pins depicting both leaders.
The badges were inspired by Chairman Mao badges worn by Chinese revolutionaries and citizens during the rule of Mao Zedong. Unlike their Chinese counterparts, which were never compulsory to wear, the North Korean badges have been an important part of North Korean attire for most of their history. As such, they are culturally more important than Mao badges ever were, and are a key part of North Korea's cult of personality. According to Jae-Cheon Lim, the badges are:
History
The inspiration for the badges were Chairman Mao badges worn by the Chinese during the Cultural Revolution, although North Korean propaganda attributes the idea to Kim Jong Il. It has been suggested by high-ranking defector Hwang Jang-yop that the Kapsan faction incident in 1967 triggered the systematic intensification of Kim Il Sung's cult of personality in general and the introduction of the badges in particular.
Badges bearing the portrait of Kim Il Sung first appeared in the late 1960s when the Mansudae Art Studio started making them for Workers' Party of Korea cadres, who started wearing them after the Kapsan faction incident. Mass-production followed in November 1970, after a decree by Kim Il Sung. The very first badges with portraits were produced by the party's Propaganda and Agitation Department. This batch of badges featured "a stern-looking portrait of Kim Il Sung with his mouth firmly closed". They were called "Party Badges" because only party officials would wear them, but ordinary North Koreans could also illegally buy them in hopes of a higher social status. These badges were made a mandatory part of the attire of every North Korean from Kim's 60th birthday on 15 April 1972 onward, when they came in three classes: for party members, one for adults, and one for students. Most would start wearing one from there on, and by 1980 virtually everyone wore the badges. The Kim Il Sung badge was redesigned after his death to feature a smiling portrait.
Badges bearing the portrait of Kim Jong Il appeared in 1982, and many started to wear one alongside their Kim Il Sung badges. The first badge containing both Kim Il Sung and Kim Jong Il appeared in the 1980s, but is different from the present double badge reserved for security services cadres. Kim Jong Il badges were discontinued in the 1990s following his alleged remark: "How can I be presented on the same level as our sole 'sun', Kim Il Sung?". In 1992, in time for Kim Jong Il's 50th birthday, a pin with his face only reappeared. It, too, was unpopular due to his known reluctance to be elevated to the level of his father. Kim Jong Il badges began to be worn more widely only around the year 2000, with a renewed design, and badges featuring both Kims only recently.
The round designs were the oldest types. The very first round design in 1953 featured Kim Il Sung's side profile in military uniform, much like their Chinese counterparts. Kim's face from the front began to be used in the 1980s. Rectangular badges appeared in the 1970s and were at first reserved for those working in state security organizations. The flag-shaped badges began to be made in the early 1980s. They featured a symbol related to a party, state, or youth organization. The one bearing the emblem of the Workers' Party became the most popular.
After the death of Kim Jong Il in December 2011, party officials started to wear the Kim Jong Il badge next to the Kim Il Sung one. Then, in April 2012, the double badge was reintroduced in its current form.
In June 2024, in photographs from the 10th plenum of the WPK Central Committee, badges depicting only Kim Jong Un were first seen on the jackets of officials, although they had previously depicted previous leaders of the state.
Badges with both leaders have been used by people traveling between regions as an item for bartering in the North Korean gray market. Previously, methamphetamine was used for bartering before various crackdowns made the practice hard. Badges eventually replaced drugs despite falling prices. In Pyongyang, too, where money and prized items are in short supply, the badges have value.
Wearing
Virtually all North Koreans wear the badges. North Koreans begin wearing the badges at 16 years old. The badges are placed above their Korean Children's Union badges.
Respect for the badges is enshrined in the Ten Principles for the Establishment of a Monolithic Ideological System, which mandate that they "must be treated with reverence and protected with utmost care". If someone is caught outside their home without a badge, they are faced with explaining themselves at the next mutual criticism session. The badges are given to eligible North Koreans for free, and are acquired through one's workplace or school. Losing, or selling, a badge results in one having to prove that they have lost the badge without a malicious intent before they are given a new one. Lacking a badge has also been associated with transgression because sometimes people who professed "anti-Kim" behavior had their badges confiscated.
A North Korean may own several different badges that they have obtained at different stages of their life, two or three on average, but some have many more.
Badges are known to have been sold to tourists at the Kim Il Sung and Kim Jong Il foundation building in Pyongyang for a 100 Euro 'donation', and after receiving permission and help of a local. Badges have been smuggled out of the country for sale and can be found in Chinese cities in particular, although selling them is illegal in China as well. Both authentic and counterfeit badges are sold in Tumen, Yanbian. Most badges found outside of the country are counterfeits, such as those regularly on sale in Dandong.
The badges are worn on inner garments only, either on the lapel or a shirt, but not on outwear coats. Usually, the badges are worn on the left side of a garment, over the heart. There are atypical ways of wearing the badges that are considered fashionable by North Koreans, the youth in particular. Schoolchildren and teenagers use the badges to "perk up" their uniforms. One such way is to wear the badge at the very edge of one's garment, for which children of upper-class families in Pyongyang in particular are known.
Although it is mandatory and obligatory to wear a badge, North Korean officials sometimes claim that it is done out of pure loyalty. The badges are not worn on some occasions such as entering places of worship.
North Koreans traveling or working abroad almost never wear the badges when not on official business.
Types
The badges are designed and made by the Mansudae Art Studio.
The badges come in different shapes and sizes. Unlike in China, where Chairman Mao badges were diverse because their production was not overseen by the government, North Korean badges have relatively little variation. All in all, there are more than 20 different designs. The size, shape, colouring, and type of metal of the design is indicative of the social status and institutional affiliations of the person wearing it. For instance, party youths wear large round badges, whereas common people wear smaller round badges.
While most badges only feature a portrait of Kim Il Sung, there are two exceptions. The most prestigious type has both Kim Il Sung and Kim Jong Il — there are three designs that feature them both: one with the two against a red banner; one with them over a North Korean flag (without a star) worn by high-ranking Chongryon; and one with them on a smaller, more curved flag with the words (meaning "Youth Potential") written under the portraits — this badge is worn by some members of the Socialist Patriotic Youth League. No other designs feature both leaders. The design is reserved to high-level Workers' Party of Korea officials only. It is so rare that seeing one "can send many a minor North Korean bureaucrat into a stupor". The other exception is badges with the portrait of Kim Jong Il only. They are worn by security services cadres and are also considerably rare.
Depending on the badge, the leader is depicted in a Western suit, military attire, or some other type of clothing.
Before Kim Jong Un was confirmed as Kim Jong Il's successor and Kim Jong Chol was groomed as the country's next leader, a limited set of Kim Jong Chol badges were reportedly made and given to cabinet, party, and army officials. Since the Tenth Plenary Meeting of the 8th Central Committee of the Workers' Party of Korea, certain party officials were seen wearing Kim Jong Un badges to the exclusion of the traditional Kim Il Sung and Kim Jong Il badge.
See also
Chairman Mao badge
Culture of North Korea
Kim Il Sung and Kim Jong Il portraits
List of things named after Kim Il Sung
Orders and medals of North Korea
Songbun
Juche ideology
References
Works cited
External links
Photos of a private collection at Reuters
Photo of a collection at Magnum Photos
Badges
Culture of North Korea
Kim Il Sung
Cultural depictions of Kim Jong Il
1967 introductions
Kim family (North Korea) | Kim Il Sung and Kim Jong Il badges | [
"Mathematics"
] | 1,957 | [
"Symbols",
"Badges"
] |
52,918,729 | https://en.wikipedia.org/wiki/2%2C5-Dimethoxy-p-cymene | 2,5-Dimethoxy-p-cymene, or thymohydroquinone dimethyl ether, is a phytochemical found in the essential oils of plants within the family Asteraceae. These essential oils, which contain the compound as a major component of the oil, have antifungal, antibacterial, and insecticidal properties.
Natural occurrence
2,5-Dimethoxy-p-cymene occurs in a variety of different plants' essential oils. Examples include:
Ayapana triplinervis (92.8%)
Apium leptophyllum (50.7 to 80.24%)
Cyathocline purpurea (57.4%)
Arnica montana (32.6%)
Laggera crispata (32.2%)
Blumea perrottetiana (30.0%)
Eupatorium capillifolium (20.8%)
Sphaeranthus indicus (18.2%)
Limbarda crithmoides (16.4)
Bubonium imbricatum (16.2%)
Chemical synthesis
2,5-Dimethoxy-p-cymene can be synthesized from carvacrol by aromatic halogenation followed by nucleophilic substitution with sodium methoxide and Williamson ether synthesis using methyl iodide.
See also
Thymoquinone
References
Hydroquinone ethers
Fungicides
Insecticides
Alkyl-substituted benzenes
Isopropyl compounds
Methoxy compounds | 2,5-Dimethoxy-p-cymene | [
"Biology"
] | 324 | [
"Fungicides",
"Biocides"
] |
52,918,746 | https://en.wikipedia.org/wiki/Proteobiotics | Proteobiotics are natural metabolites which are produced by fermentation process of specific probiotic strains. These small oligopeptides were originally discovered in and isolated from culture media used to grow probiotic bacteria and may account for some of the health benefits of probiotics.
Several genera of probiotic bacteria are known to produce proteobiotics, including Lactococcus spp., Pediococcus spp. Lactobacillus spp. and Bifidobacterium spp.
Mode of action
Recent studies have explored mode of action of proteobiotics and their potential benefits in maintaining the ratio of beneficial bacteria, lowering bacterial imbalance, and improving gut function. However, any of the statements based on research have not been evaluated by the US Food and Drug Administration.
Unlike other molecules produced by probiotic bacteria, such as organic acids and bacteriocins, proteobiotics are natural metabolites which interfere with quorum sensing, the cell-to-cell communications which occur between bacterial cells, mainly by interfering with the LuxS quorum sensing system. These quorum-sensing systems allow bacteria to respond to changes in their environment and play a role in the ability of pathogens to evade host defence mechanisms. By interfering with quorum sensing, proteobiotics inhibit the cascade of events leading to adhesion to, and invasion of, host cells. This is achieved through reduced expression of specific virulence genes (typically found on pathogenicity islands) that facilitate the infection process. Specifically, proteobiotics inhibit virulence genes involved in toxin production, biofilm formation, cell adhesion and invasion. In enterohemorrhagic E. coli and Salmonella spp., genes associated with Type 3 Secretion Systems seem to be the main targets.
The degree to which proteobiotics can reduce virulence-gene expression depends on the pathogen and the source of the proteobiotics. Lactobacillus acidophilus-derived proteobiotics down-regulate virulence genes in enterohemorrhagic Escherichia coli, Clostridioides difficile, Salmonella Typhimurium, Listeria monocytogenes and Campylobacter jejuni. Whereas those produced by Bifidobacterium spp. have been shown to impact virulence gene expression in Campylobacter jejuni, enterohemorrhagic Escherichia coli, Clostridioides difficile, Clostridium perfringens, and Salmonella Typhimurium.
References
Anti-infective agents
Peptides
Bacteriology
Probiotics | Proteobiotics | [
"Chemistry"
] | 566 | [
"Biomolecules by chemical classification",
"Anti-infective agents",
"Molecular biology",
"Chemicals in medicine",
"Peptides"
] |
52,918,977 | https://en.wikipedia.org/wiki/AIS%20station | AIS receiver station receive telegrams from near by vessels via VHF data (about 162 MHz) and sending it to Automatic identification system to be recorded and used for vessel tracking and other purpose.
References
See also
GPS Exchange Format
Related standards
NMEA 0183
NMEA 2000
NMEA OneNet, a future standard based on Ethernet
Electronic navigation
Navigational equipment
Technology systems | AIS station | [
"Technology",
"Engineering"
] | 74 | [
"Systems engineering",
"Technology systems",
"nan"
] |
52,918,982 | https://en.wikipedia.org/wiki/List%20of%20microquasars | This is a list of all known microquasars:
1
1E 1740,7-2942
4
4U1630-47
C
Cygnus X-1
Cygnus X-3 (V1521)
CI Cam
G
GRS 1915+105
GRO J1655-40
GX339-4
K
KS1731-260
L
LS I +61 303
LS 5039
S
Scorpius X-1
SS 433
V
V404 Cygni
V4641 Sgr
V691 CrA
X
XMMU J004243.6+412519
XTE J1118+480
XTE J1550-564
See also
List of quasars
References
microquasars | List of microquasars | [
"Astronomy"
] | 154 | [
"Astronomy-related lists",
"Astronomical objects",
"Lists of astronomical objects"
] |
52,920,368 | https://en.wikipedia.org/wiki/Qstack | Qstack is a cloud management platform developed by GreenQloud, a cloud computing software company founded in Reykjavik, Iceland in February 2010. Qstack enables its users to manage multiple clouds and hybrid deployments through a single self-service portal.
Qstack is in continuous development, incorporating developments within infrastructure, cloud, and application management solutions. The next release of Qstack is slated for June 2017.
History
In 2014 when Jonsi Stefansson joined as CEO, Greenqloud pivoted its operational focus to development of Qstack with beta launch in the fall of 2015, and began offering support, technical services and certifications for the software.
Features
Qstack is hypervisor agnostic (KVM, VMware, Hyper-V) and can manage private clouds in multiple locations as well as AWS, Azure, and EC2-compatible public clouds from its user interface. Qstack combines proprietary software with open-source components, and the company claims to harden them to meet the strict security standards often required by enterprise deployments. Qstack features VM templates for Windows, Linux, and other operating systems. It also features full SSH/RDP access to instances, virtual routers, firewalls, and load balancers built into the interface.
Reception
In a 2015 review, IDG columnist J. Peter Bruzzese praised Qstack’s user interface for its ease-of-use and clean look.
References
Cloud infrastructure
Cloud computing
Cloud computing providers
Virtual machines | Qstack | [
"Technology"
] | 312 | [
"Cloud infrastructure",
"IT infrastructure"
] |
52,920,749 | https://en.wikipedia.org/wiki/Acceleration%20%28special%20relativity%29 | Accelerations in special relativity (SR) follow, as in Newtonian Mechanics, by differentiation of velocity with respect to time. Because of the Lorentz transformation and time dilation, the concepts of time and distance become more complex, which also leads to more complex definitions of "acceleration". SR as the theory of flat Minkowski spacetime remains valid in the presence of accelerations, because general relativity (GR) is only required when there is curvature of spacetime caused by the energy–momentum tensor (which is mainly determined by mass). However, since the amount of spacetime curvature is not particularly high on Earth or its vicinity, SR remains valid for most practical purposes, such as experiments in particle accelerators.
One can derive transformation formulas for ordinary accelerations in three spatial dimensions (three-acceleration or coordinate acceleration) as measured in an external inertial frame of reference, as well as for the special case of proper acceleration measured by a comoving accelerometer. Another useful formalism is four-acceleration, as its components can be connected in different inertial frames by a Lorentz transformation. Also equations of motion can be formulated which connect acceleration and force. Equations for several forms of acceleration of bodies and their curved world lines follow from these formulas by integration. Well known special cases are hyperbolic motion for constant longitudinal proper acceleration or uniform circular motion. Eventually, it is also possible to describe these phenomena in accelerated frames in the context of special relativity, see Proper reference frame (flat spacetime). In such frames, effects arise which are analogous to homogeneous gravitational fields, which have some formal similarities to the real, inhomogeneous gravitational fields of curved spacetime in general relativity. In the case of hyperbolic motion one can use Rindler coordinates, in the case of uniform circular motion one can use Born coordinates.
Concerning the historical development, relativistic equations containing accelerations can already be found in the early years of relativity, as summarized in early textbooks by Max von Laue (1911, 1921) or Wolfgang Pauli (1921). For instance, equations of motion and acceleration transformations were developed in the papers of Hendrik Antoon Lorentz (1899, 1904), Henri Poincaré (1905), Albert Einstein (1905), Max Planck (1906), and four-acceleration, proper acceleration, hyperbolic motion, accelerating reference frames, Born rigidity, have been analyzed by Einstein (1907), Hermann Minkowski (1907, 1908), Max Born (1909), Gustav Herglotz (1909), Arnold Sommerfeld (1910), von Laue (1911), Friedrich Kottler (1912, 1914), see section on history.
Three-acceleration
In accordance with both Newtonian mechanics and SR, three-acceleration or coordinate acceleration is the first derivative of velocity with respect to coordinate time or the second derivative of the location with respect to coordinate time:
.
However, the theories sharply differ in their predictions in terms of the relation between three-accelerations measured in different inertial frames. In Newtonian mechanics, time is absolute by in accordance with the Galilean transformation, therefore the three-acceleration derived from it is equal too in all inertial frames:
.
On the contrary in SR, both and depend on the Lorentz transformation, therefore also three-acceleration and its components vary in different inertial frames. When the relative velocity between the frames is directed in the x-direction by with as Lorentz factor, the Lorentz transformation has the form
or for arbitrary velocities of magnitude :
In order to find out the transformation of three-acceleration, one has to differentiate the spatial coordinates and of the Lorentz transformation with respect to and , from which the transformation of three-velocity (also called velocity-addition formula) between and follows, and eventually by another differentiation with respect to and the transformation of three-acceleration between and follows. Starting from (), this procedure gives the transformation where the accelerations are parallel (x-direction) or perpendicular (y-, z-direction) to the velocity:
or starting from () this procedure gives the result for the general case of arbitrary directions of velocities and accelerations:
This means, if there are two inertial frames and with relative velocity , then in the acceleration of an object with momentary velocity is measured, while in the same object has an acceleration and has the momentary velocity . As with the velocity addition formulas, also these acceleration transformations guarantee that the resultant speed of the accelerated object can never reach or surpass the speed of light.
Four-acceleration
If four-vectors are used instead of three-vectors, namely as four-position and as four-velocity, then the four-acceleration of an object is obtained by differentiation with respect to proper time instead of coordinate time:
where is the object's three-acceleration and its momentary three-velocity of magnitude with the corresponding Lorentz factor . If only the spatial part is considered, and when the velocity is directed in the x-direction by and only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered, the expression is reduced to:
Unlike the three-acceleration previously discussed, it is not necessary to derive a new transformation for four-acceleration, because as with all four-vectors, the components of and in two inertial frames with relative speed are connected by a Lorentz transformation analogous to (, ). Another property of four-vectors is the invariance of the inner product or its magnitude , which gives in this case:
Proper acceleration
In infinitesimal small durations there is always one inertial frame, which momentarily has the same velocity as the accelerated body, and in which the Lorentz transformation holds. The corresponding three-acceleration in these frames can be directly measured by an accelerometer, and is called proper acceleration or rest acceleration. The relation of in a momentary inertial frame and measured in an external inertial frame follows from (, ) with , , and . So in terms of (), when the velocity is directed in the x-direction by and when only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered, it follows:
Generalized by () for arbitrary directions of of magnitude :
There is also a close relationship to the magnitude of four-acceleration: As it is invariant, it can be determined in the momentary inertial frame , in which and by it follows :
Thus the magnitude of four-acceleration corresponds to the magnitude of proper acceleration. By combining this with (), an alternative method for the determination of the connection between in and in is given, namely
from which () follows again when the velocity is directed in the x-direction by and only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered.
Acceleration and force
Assuming constant mass , the four-force as a function of three-force is related to four-acceleration () by , thus:
The relation between three-force and three-acceleration for arbitrary directions of the velocity is thus
When the velocity is directed in the x-direction by and only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered
Therefore, the Newtonian definition of mass as the ratio of three-force and three-acceleration is disadvantageous in SR, because such a mass would depend both on velocity and direction. Consequently, the following mass definitions used in older textbooks are not used anymore:
as "longitudinal mass",
as "transverse mass".
The relation () between three-acceleration and three-force can also be obtained from the equation of motion
where is the three-momentum. The corresponding transformation of three-force between in and in (when the relative velocity between the frames is directed in the x-direction by and only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered) follows by substitution of the relevant transformation formulas for , , , , or from the Lorentz transformed components of four-force, with the result:
Or generalized for arbitrary directions of , as well as with magnitude :
Proper acceleration and proper force
The force in a momentary inertial frame measured by a comoving spring balance can be called proper force. It follows from (, ) by setting and as well as and . Thus by () where only accelerations parallel (x-direction) or perpendicular (y-, z-direction) to the velocity are considered:
Generalized by () for arbitrary directions of of magnitude :
Since in momentary inertial frames one has four-force and four-acceleration , equation () produces the Newtonian relation , therefore (, , ) can be summarized
By that, the apparent contradiction in the historical definitions of transverse mass can be explained. Einstein (1905) described the relation between three-acceleration and proper force
,
while Lorentz (1899, 1904) and Planck (1906) described the relation between three-acceleration and three-force
.
Curved world lines
By integration of the equations of motion one obtains the curved world lines of accelerated bodies corresponding to a sequence of momentary inertial frames (here, the expression "curved" is related to the form of the worldlines in Minkowski diagrams, which should not be confused with "curved" spacetime of general relativity). In connection with this, the so-called clock hypothesis of clock postulate has to be considered: The proper time of comoving clocks is independent of acceleration, that is, the time dilation of these clocks as seen in an external inertial frame only depends on its relative velocity with respect to that frame. Two simple cases of curved world lines are now provided by integration of equation () for proper acceleration:
a) Hyperbolic motion: The constant, longitudinal proper acceleration by () leads to the world line
The worldline corresponds to the hyperbolic equation , from which the name hyperbolic motion is derived. These equations are often used for the calculation of various scenarios of the twin paradox or Bell's spaceship paradox, or in relation to space travel using constant acceleration.
b) The constant, transverse proper acceleration by () can be seen as a centripetal acceleration, leading to the worldline of a body in uniform rotation
where is the tangential speed, is the orbital radius, is the angular velocity as a function of coordinate time, and as the proper angular velocity.
A classification of curved worldlines can be obtained by using the differential geometry of triple curves, which can be expressed by spacetime Frenet-Serret formulas. In particular, it can be shown that hyperbolic motion and uniform circular motion are special cases of motions having constant curvatures and torsions, satisfying the condition of Born rigidity. A body is called Born rigid if the spacetime distance between its infinitesimally separated worldlines or points remains constant during acceleration.
Accelerated reference frames
Instead of inertial frames, these accelerated motions and curved worldlines can also be described using accelerated or curvilinear coordinates. The proper reference frame established that way is closely related to Fermi coordinates. For instance, the coordinates for an hyperbolically accelerated reference frame are sometimes called Rindler coordinates, or those of a uniformly rotating reference frame are called rotating cylindrical coordinates (or sometimes Born coordinates). In terms of the equivalence principle, the effects arising in these accelerated frames are analogous to effects in a homogeneous, fictitious gravitational field. In this way it can be seen, that the employment of accelerating frames in SR produces important mathematical relations, which (when further developed) play a fundamental role in the description of real, inhomogeneous gravitational fields in terms of curved spacetime in general relativity.
History
For further information see von Laue, Pauli, Miller, Zahar, Gourgoulhon, and the historical sources in history of special relativity.
1899 Hendrik Lorentz derived the correct (up to a certain factor ) relations for accelerations, forces and masses between a resting electrostatic systems of particles (in a stationary aether), and a system emerging from it by adding a translation, with as the Lorentz factor:
, , for by ();
, , for by ();
, , for , thus longitudinal and transverse mass by ();
Lorentz explained that he has no means of determining the value of . If he had set , his expressions would have assumed the exact relativistic form.
1904 Lorentz derived the previous relations in a more detailed way, namely with respect to the properties of particles resting in the system and the moving system , with the new auxiliary variable equal to compared to the one in 1899, thus:
for as a function of by ();
for as a function of by ();
for as a function of by ();
for longitudinal and transverse mass as a function of the rest mass by (, ).
This time, Lorentz could show that , by which his formulas assume the exact relativistic form. He also formulated the equation of motion
with
which corresponds to () with , with , , , , , and as electromagnetic rest mass. Furthermore, he argued, that these formulas should not only hold for forces and masses of electrically charged particles, but for other processes as well so that the earth's motion through the aether remains undetectable.
1905 Henri Poincaré introduced the transformation of three-force ():
with , and as the Lorentz factor, the charge density. Or in modern notation: , , , and . As Lorentz, he set .
1905 Albert Einstein derived the equations of motions on the basis of his special theory of relativity, which represent the relation between equally valid inertial frames without the action of a mechanical aether. Einstein concluded, that in a momentary inertial frame the equations of motion retain their Newtonian form:
.
This corresponds to , because and and . By transformation into a relatively moving system he obtained the equations for the electrical and magnetic components observed in that frame:
.
This corresponds to () with , because and and and . Consequently, Einstein determined the longitudinal and transverse mass, even though he related it to the force in the momentary rest frame measured by a comoving spring balance, and to the three-acceleration in system :
This corresponds to () with .
1905 Poincaré introduces the transformation of three-acceleration ():
where as well as and and .
Furthermore, he introduced the four-force in the form:
where and and .
1906 Max Planck derived the equation of motion
with
and
and
The equations correspond to () with
, with and and , in agreement with those given by Lorentz (1904).
1907 Einstein analyzed a uniformly accelerated reference frame and obtained formulas for coordinate dependent time dilation and speed of light, analogous to those given by Kottler-Møller-Rindler coordinates.
1907 Hermann Minkowski defined the relation between the four-force (which he called the moving force) and the four acceleration
corresponding to .
1908 Minkowski denotes the second derivative with respect to proper time as "acceleration vector" (four-acceleration). He showed, that its magnitude at an arbitrary point of the worldline is , where is the magnitude of a vector directed from the center of the corresponding "curvature hyperbola" () to .
1909 Max Born denotes the motion with constant magnitude of Minkowski's acceleration vector as "hyperbolic motion" (), in the course of his study of rigidly accelerated motion. He set (now called proper velocity) and as Lorentz factor and as proper time, with the transformation equations
.
which corresponds to () with and . Eliminating Born derived the hyperbolic equation , and defined the magnitude of acceleration as . He also noticed that his transformation can be used to transform into a "hyperbolically accelerated reference system" ().
1909 Gustav Herglotz extends Born's investigation to all possible cases of rigidly accelerated motion, including uniform rotation.
1910 Arnold Sommerfeld brought Born's formulas for hyperbolic motion in a more concise form with as the imaginary time variable and as an imaginary angle:
He noted that when are variable and is constant, they describe the worldline of a charged body in hyperbolic motion. But if are constant and is variable, they denote the transformation into its rest frame.
1911 Sommerfeld explicitly used the expression "proper acceleration" () for the quantity in , which corresponds to (), as the acceleration in the momentary inertial frame.
1911 Herglotz explicitly used the expression "rest acceleration" () instead of proper acceleration. He wrote it in the form and which corresponds to (), where is the Lorentz factor and or are the longitudinal and transverse components of rest acceleration.
1911 Max von Laue derived in the first edition of his monograph "Das Relativitätsprinzip" the transformation for three-acceleration by differentiation of the velocity addition
equivalent to () as well as to Poincaré (1905/6). From that he derived the transformation of rest acceleration (equivalent to ), and eventually the formulas for hyperbolic motion which corresponds to ():
thus
,
and the transformation into a hyperbolic reference system with imaginary angle :
.
He also wrote the transformation of three-force as
equivalent to () as well as to Poincaré (1905).
1912–1914 Friedrich Kottler obtained general covariance of Maxwell's equations, and used four-dimensional Frenet-Serret formulas to analyze the Born rigid motions given by Herglotz (1909). He also obtained the proper reference frames for hyperbolic motion and uniform circular motion.
1913 von Laue replaced in the second edition of his book the transformation of three-acceleration by Minkowski's acceleration vector for which he coined the name "four-acceleration" (), defined by with as four-velocity. He showed, that the magnitude of four-acceleration corresponds to the rest acceleration by
,
which corresponds to (). Subsequently, he derived the same formulas as in 1911 for the transformation of rest acceleration and hyperbolic motion, and the hyperbolic reference frame.
References
Bibliography
; First edition 1911, second expanded edition 1913, third expanded edition 1919.
In English:
Historical papers
External links
Mathpages: Transverse Mass in Einstein's Electrodynamics, Accelerated Travels, Born Rigidity, Acceleration, and Inertia, Does A Uniformly Accelerating Charge Radiate?
Physics FAQ: Acceleration in Special Relativity, The Relativistic Rocket
Special relativity
Special relativity | Acceleration (special relativity) | [
"Physics",
"Mathematics"
] | 3,785 | [
"Physical quantities",
"Acceleration",
"Quantity",
"Special relativity",
"Theory of relativity",
"Wikipedia categories named after physical quantities"
] |
52,920,806 | https://en.wikipedia.org/wiki/International%20Society%20for%20Invertebrate%20Morphology | International Society for Invertebrate Morphology (ISIM) was founded during the 1st International Congress on Invertebrate Morphology, in Copenhagen, August 2008. The objectives of the society are to promote international collaboration and provide educational opportunities and training on invertebrate morphology, and to organize and promote the international congresses of invertebrate morphology, international meetings and other forms of scientific exchange.
Meetings
ICIM 1 (2008) University of Copenhagen, Denmark
ICIM 2 (2011) Harvard University, Cambridge Massachusetts, USA
ICIM 3 (2014) Humboldt-Universität zu Berlin, Germany
ICIM 4 (2017) Lomonosov Moscow State University, Russia ()
ICIM 5 (2022), Vienna, Austria
ICIM 6 (2025), Chile
References
External links
https://icim5-2020.univie.ac.at/
Biology societies
Morphology (biology) | International Society for Invertebrate Morphology | [
"Biology"
] | 186 | [
"Morphology (biology)"
] |
52,921,086 | https://en.wikipedia.org/wiki/Uragan-2M | Uragan-2M (U-2M, ) is a stellarator (magnetic plasma confinement, controlled thermonuclear fusion experiment) installed at the Institute of Plasma Physics National Science Center, which is part of the Kharkiv Institute of Physics and Technology (IFS KIPT) in Kharkiv, Ukraine. It was the largest stellarator (torsatron) in Europe until the construction of Wendelstein 7-X.
Specifications
Uragan-2M is a medium-sized stellarator with reduced helical corrugations. The unit has a torus radius of , a plasma radius of up to , and a toroidal magnetic field of up to .
See also
Controlled thermonuclear fusion
References
Further reading
Stellarators
Nuclear research institutes
Plasma physics facilities | Uragan-2M | [
"Physics",
"Engineering"
] | 168 | [
"Nuclear research institutes",
"Nuclear organizations",
"Plasma physics",
"Plasma physics stubs",
"Plasma physics facilities"
] |
52,921,789 | https://en.wikipedia.org/wiki/Land%20consumption | Land consumption as part of human resource consumption is the conversion of land with healthy soil and intact habitats into areas for industrial agriculture, traffic (road building) and especially urban human settlements. More formally, the EEA has identified three land consuming activities:
The expansion of built-up area which can be directly measured;
the absolute extent of land that is subject to exploitation by agriculture, forestry or other economic activities; and
the over-intensive exploitation of land that is used for agriculture and forestry.
In all of those respects, land consumption is equivalent to typical land use in industrialized regions and civilizations.
Since often aforementioned conversion activities are virtually irreversible, the term land loss is also used. From 1990 to 2000, of open space were consumed in the U.S. In Germany, land is being consumed at a rate of more than every day (~ per 10 years). In European Union, land take is estimated approximately about to 1.2 million hectares in 21 EU countries over the period 1990–2006.
Land loss can also happen due to natural factors, like erosion or desertification - nevertheless most of those can also eventually be tracked back to human activities. Another slightly different interpretation of the term is the forced displacement or compulsory acquisition of a native people or settlers from their original land due to land grabbing, etc. Again, in most cases, this will be due to economic reasons like search for profitable investment and commodification of natural resources.
Reducing global land loss, which progresses at an alarming rate, is vital since the land footprint, the area required both domestically and abroad to produce the goods and services consumed by a country or region, can be much larger than the land actually used or even available in the country itself.
While land prices have surged in the first few years of the 21st century, land consumption economy still lacks environmental full-cost accounting to add the long-term costs of environmental degradation.
Consequences of land consumption
The major effects of land conversion for economic growth are:
Land degradation
Habitat loss – built-up areas support only particularly adapted species
Soil degradation – loss or contamination of top soil by civilization waste and general pollution
Soil compaction – buildings, heavy machinery and vehicle traffic compact the soil to a degree that macrobiotic soil life is eradicated
Impervious surfaces – asphalt and concrete seal off the soil from the atmosphere and disrupt natural water and biogeochemical cycles
See also
Land reclamation
Land rehabilitation
Land restoration
Land use
References
Land use
Ecology
Environmental issues with soil
Human impact on the environment | Land consumption | [
"Biology",
"Environmental_science"
] | 504 | [
"Environmental soil science",
"Environmental issues with soil",
"Ecology"
] |
52,922,245 | https://en.wikipedia.org/wiki/Correlative%20light-electron%20microscopy | Correlative light-electron microscopy (CLEM) is the combination of an optical microscope – usually a fluorescence microscope – with an electron microscope. In an integrated CLEM system, the sample is imaged using an electron beam and an optical light path simultaneously. Traditionally, samples would be imaged using two separate microscopy modalities, potentially at different facilities and using different sample preparation methods. Integrated CLEM is thus considered to be beneficial because the methodology is quicker and easier, and it reduces the chance of changes in the sample during the process of data collection. Overlay of the two images is thus performed automatically as a result of the integration of two microscopes.
This technique is used in order to obtain information at different length scales: the electron microscope provides high-resolution information down to the nano-scale, while the fluorescence microscope highlights the regions of interest. CLEM is used for various disciplines in the life sciences, including neuroscience, tissue research, and protein research.
Fluorescence microscope
In preparation for imaging with a fluorescence microscope, different methods can be used, such as fluorophores or dyes, immunolabeling, and genetically encoded fluorescent proteins. Different fluorescent labels can be used in order to highlight multiple regions of interest in the sample. Recently Kumar et al. combined FRET based molecular tension measurements with cryo-electron microscopy to study how force on talin (a focal adhesion protein which directly links integrins to actin) is related to actin organization. Regions of high talin tension have highly aligned and linear filamentous actin while regions of low tension have less well-aligned actin structure.
Electron microscope
The electron microscope is used to obtain structural information at the nano-scale. Unlike an optical microscope, an electron microscope is able to surpass the diffraction limit of light. This is because the wavelength of accelerated electrons is much shorter than the wavelength of visible light.
References
Further reading
Electron microscopy | Correlative light-electron microscopy | [
"Chemistry"
] | 398 | [
"Electron",
"Electron microscopy",
"Microscopy"
] |
52,923,339 | https://en.wikipedia.org/wiki/WR%209 | WR 9 is a spectroscopic binary in the constellation Puppis consisting of a Wolf-Rayet star and a class O star. It is around 12,000 light years away.
WR 9 is a binary with two components in a circular 14-day orbit. The Wolf-Rayet component is often identified as the primary because it dominates the spectrum with its broad emission lines, although it is less massive, less luminous, and less visually bright than its companion. The companion is an approximately O7 star.
The spectrum is dominated by broad emission lines, those of CIV being the strongest, followed by HeII. CIII lines are seen but much weaker. OV lines are also stronger than CIII. The classification is usually given as WC4, although it has previously been assigned as WC5. By comparison, the absorption lines of the secondary star are narrower and weaker, although at blue and shorter wavelengths they become stronger than the WR lines. The spectral type of the secondary can be set at O7. The luminosity class cannot be determined clearly, although it has been suggested to be a supergiant. The Wolf-Rayet star shows no hydrogen in its spectrum and is thought to be hydrogen-free. It is calculated to consist of 42% helium and 58% heavier elements, mostly carbon and oxygen.
WR 9 is listed as an eclipsing binary in the General Catalogue of Variable Stars, as well as having the more irregular brightness changes frequently seen in Wolf Rayet stars. The total amplitude is only 0.04 magnitudes. The eclipses are so shallow because only the atmosphere of the WR star eclipses the O star on each orbit.
References
Puppis
Wolf–Rayet stars
Durchmusterung objects
063099
Spectroscopic binaries
Puppis, V443
037876
O-type stars | WR 9 | [
"Astronomy"
] | 376 | [
"Puppis",
"Constellations"
] |
52,923,676 | https://en.wikipedia.org/wiki/Hedgehog%20pathway%20inhibitor | Hedgehog pathway inhibitors, also sometimes called hedgehog inhibitors, are small molecules that inhibit the activity of a component of the Hedgehog signaling pathway. Due to the role of aberrant Hedgehog signaling in tumor progression and cancer stem cell maintenance across cancer types, inhibition of the Hedgehog signaling pathway can be a useful strategy for restricting tumor growth and for preventing the recurrence of the disease post-surgery, post-radiotherapy, or post-chemotherapy. Thus, Hedgehog pathway inhibitors are an important class of anti-cancer drugs.
At least three Hedgehog pathway inhibitors have been approved by the Food and Drug Administration (FDA) for cancer treatment. These include vismodegib and sonidegib, both inhibitors of Smoothened (SMO), which are being used for the treatment of basal cell carcinoma. Arsenic trioxide, an inhibitor of GLI transcription factors, is being used for the treatment of acute promyelocytic leukemia. In addition, multiple other Hedgehog pathway inhibitors are in different phases of clinical trials.
Overview of the Hedgehog signaling pathway
The classical Hedgehog signaling pathway involves glycoproteins that are secreted by cells into the intercellular space. Multiple such glycoproteins have been characterized: Sonic Hedgehog (Shh), Indian Hedgehog (Ihh), and Desert Hedgehog (Dhh). Among these, Shh is the most potent. It binds and inactivates the transmembrane protein Patched1 (PTCH1). In the absence of Shh, PTCH1 inhibits the activity of Smoothened (SMO), another transmembrane protein. Upon the inactivation of PTCH1 by Shh, glioma-associated (GLI) transcription factors enter the nucleus and activate the expression of multiple genes including Myc, Bcl-2, NANOG, and SOX2. Targets of GLIs include genes involved in cell proliferation, apoptosis, angiogenesis, epithelial-mesenchymal transition, and self-renewal of stem cells.
In addition to the canonical pathway described above, some alternate pathways related to Shh signaling have also been reported. One example is the activation of SMO without the subsequent entry of GLI transcription factors into the nucleus. Another, better characterized pathway is the activation of GLIs independent of Shh or PTCH1 / SMO. This alternate mode of triggering the activity of GLIs is common in cancer cells. Oncogenes such as KRAS can activate the GLIs in the absence of Shh signaling. Transcriptional activity of GLIs is also upregulated upon the knockdown of p53, a tumor-suppressor gene often lost during cancer progression.
Role of Hedgehog signaling in cancer
As mentioned above, targets of the Hedgehog signaling pathway include genes involved in cell proliferation, apoptosis, angiogenesis, epithelial-mesenchymal transition, and self-renewal of stem cells. Dysregulation of all these cellular processes has been reported across cancer types. Abnormal control of these processes in cancer cells is often a consequence of dysregulated Shh signaling.
The first major breakthrough in understanding the role of Shh signaling in cancer progression was the discovery that mutations in the PTCH1 gene, which codes for the PTCH1 protein, were responsible for Gorlin syndrome. Gorlin syndrome is an autosomal dominant disorder characterized by developmental abnormalities and increased risk of developing basal cell carcinoma or medulloblastoma. Mutations in the PTCH1 gene can lead to the abnormal activation of GLI transcriptional activity which in turn promotes tumor development and progression. Overexpression of Shh ligand has been reported in multiple cancer types including pancreatic, colorectal, prostate, and gliomas. This can lead to the activation of GLI transcriptional activity in the cell over-secreting Shh (autocrine signaling) or in neighboring cells (paracrine signaling). Further, Shh ligands can stimulate the production of growth factors by stromal cells present in the tumor microenvironment. These growth factors, in turn, promote the growth, survival, and proliferation of cancer cells.
Aberrant Shh signaling has also been implicated in the maintenance of cancer stem cells (CSCs). In chronic myeloid leukemia and breast cancer, inhibition of Shh signaling has been shown to reduce stem cell propagation and renewal. In pancreatic and colorectal cancer, Shh signaling in CSCs drives epithelial-mesenchymal transition and, ultimately, cancer metastasis. CSCs exhibit increased potential for self-renewal, differentiation, and for starting secondary tumors at distant organ sites. CSCs also exhibit mechanisms that drive resistance to chemotherapies and radiotherapy. As a result, while chemotherapy and radiotherapy are often successful in eliminating the bulk of the tumor (which consists of non-CSCs), CSCs that are left behind can lead to tumor recurrence. Thus, via its role in CSC maintenance, Shh signaling contributes towards the failure of anti-cancer therapies.
Mechanism of action
Given the role of Shh signaling in promoting tumor progression and in the failure of anti-cancer therapies, the Hedgehog signaling pathway is an important therapeutic target for restricting tumor progression and to prevent disease recurrence post-treatment. Different parts of the Hedgehog signaling pathway may be targeted to abrogate the activation of pathways that promote tumor progression.
SMO Inhibitors
Inhibition of the transmembrane protein Smoothened (SMO) prevents the induction of GLI transcriptional activity upon exposure of cancer cells to Shh ligands. Loss of induction of GLIs upon activation of Shh signaling inhibits the ability of Shh signaling to promote tumor progression and cancer stem cell maintenance. Therefore, SMO has been a primary target in the development of Hedgehog pathway inhibitors. Two such inhibitors, Sonidegib and Vismodegib have been approved by the Food and Drug Administration (FDA) for treating basal cell carcinoma. Multiple other SMO inhibitors are in active clinical trials.
GDC-0449 (vismodegib / Erivedge)
Vismodegib was created by Roche / Genentech / Curis. It directly binds to SMO, preventing GLI activation. In January 2012, it became the first Hedgehog pathway inhibitor to be approved by the FDA for the treatment of any cancer. Vismodegib is currently used for the treatment of metastatic basal cell carcinoma (BCC) in adults. It is also used for treating patients with locally advanced BCC who are not candidates for surgery or radiation therapy. However, it has been shown that cancer cells in BCC patients can develop resistance to vismodegib via mutations in the SMO protein which prevents the binding of the drug to SMO. Effectiveness of vismodegib as a monotherapy and in combination with other chemotherapies is currently being tested in multiple clinical trials across cancer types, including medulloblastoma, small cell lung cancer, pancreatic cancer, intracranial meningioma, recurrent glioblastoma, and acute myeloid leukemia.
LDE-225 (erismodegib / sonidegib / Odomzo)
Sonidegib was created by Novartis. It is a SMO antagonist that can induce arrest of cell division and promote apoptosis in cancer cells. Sonidegib has been effective in limiting the invasive potential of multiple cancer types including glioblastoma, prostate cancer, and renal cell carcinoma. It received FDA approval in July 2015 and is being used for the treatment of BCC that has recurred post-surgery or post-radiation therapy. Sonidegib can also be used in BCC patients who are not candidates for surgery or radiation therapy. Effectiveness of this drug in other cancer types including hematological malignancies is currently being tested in multiple clinical trials.
Other SMO inhibitors currently under clinical trial include IPI-926 (saridegib), BMS-833923 / XL139 (developed by Bristol-Myers Squibb / Exelexis), PF-04449913 (glasdegib; developed by Pfizer), and LY2940680 (taladegib; developed by Eli Lilly and Company).
GLI inhibitors
GLI transcription factors are the terminal effectors of the Hedgehog signaling pathway. Thus, inhibition of GLIs abrogates the ability of Hedgehog signaling to trigger processes that contribute towards tumor progression and recurrence. Since the transcriptional activity of GLIs can be activated via alternate pathways, independent of SMO, GLIs are an important therapeutic target in the development of Hedgehog pathway inhibitors for cancer treatment.
GANTs
GANTs, or GLI inhibitors, were discovered at the National Cancer Institute. GANT-58 and GANT-61 have both been shown to inhibit the GLI-mediated activation of genes. GANT-61 effectively reduced the DNA-binding affinity of GLI1 and GLI2 in multiple cancer cell lines, including rhabdomyosarcoma, osteosarcoma, neuroblastoma, and ovarian cancer.
Arsenic trioxide (ATO)
Arsenic Trioxide (ATO) directly binds to GLI1 and GLI2 and inhibits the expression of target genes of the Hedgehog signaling pathway, thereby promoting cancer cell apoptosis and reducing cancer cell growth. ATO has been approved by the FDA for the treatment of acute promyelocytic leukemia. Further, it has been shown to be effective in restricting the growth of malignant pleural mesothelioma, malignant rhabdosarcoma, prostate cancer, and colon cancer cell lines. ATO has also been shown to inhibit cancer stem cell maintenance in pancreatic cancer. Several clinical trials, ranging from Phase I to Phase IV, are currently underway to test the effectiveness of ATO in both solid tumors and hematological malignancies.
Shh inhibitors
Sonic Hedgehog (Shh) is the most potent of the three Hedgehog ligands. Inhibition of Shh expression and activity can thus be an effective way of restricting Hedgehog signaling-mediated tumor progression. RU-SKI 43 inhibits the activity of SHHat, an enzyme that catalyzes the palmitoylation of Shh. Since palmitoylation is essential for the activity of Shh, inhibition of SHHat by RU-SKI 43 inhibits Shh signaling in cancer cells. 5E1, a monoclonal antibody against Shh, has been shown to inhibit medulloblastoma growth in mouse models. 5E1 also restricts the proliferation of pancreatic cancer cells in mice. While shown to be effective in the lab, both these Shh inhibitors are yet to make their way to human trials.
References
Hedgehog signaling pathway | Hedgehog pathway inhibitor | [
"Chemistry"
] | 2,281 | [
"Hedgehog signaling pathway",
"Signal transduction"
] |
52,923,863 | https://en.wikipedia.org/wiki/Glasdegib | Glasdegib, sold under the brand name Daurismo, is a medication for the treatment of newly-diagnosed acute myeloid leukemia (AML) in adults older than 75 years or those who have comorbidities that preclude use of intensive induction chemotherapy. It is taken by mouth and is used in combination with low-dose cytarabine.
The recommended dose of glasdegib is 100 mg orally once daily on days 1 to 28 in combination with cytarabine 20 mg subcutaneously twice daily on days 1 to 10 of each 28-day cycle in the absence of unacceptable toxicity or loss of disease control.
The most common adverse reactions are anemia, fatigue, hemorrhage, febrile neutropenia, musculoskeletal pain, nausea, edema, thrombocytopenia, dyspnea, decreased appetite, dysgeusia, mucositis, constipation, and rash.
It is a small molecule inhibitor of sonic hedgehog, which is a protein overexpressed in many types of cancer. It inhibits the sonic hedgehog receptor smoothened (SMO), as do most drugs in its class.
History
Glasdegib was approved for medical use in the United States in December 2018.
FDA approval was based on a multicenter, open-label, randomized study (BRIGHT AML 1003, NCT01546038) that included 115 subjects with newly-diagnosed AML who met at least one of the following criteria: a) age 75 years or older, b) severe cardiac disease, c) baseline Eastern Cooperative Oncology Group performance status of 2, or d) baseline serum creatinine >1.3 mg/dL. Subjects were randomized 2:1 to receive glasdegib, 100 mg daily, with LDAC 20 mg subcutaneously twice daily on days 1 to 10 of a 28-day cycle (N=77) or LDAC alone (N=38) in 28-day cycles until disease progression or unacceptable toxicity. The trial was conducted in United States, Canada and Europe.
Efficacy was established based on an improvement in overall survival (date of randomization to death from any cause). With a median follow-up of 20 months, median survival was 8.3 months (95% CI: 4.4, 12.2) for the glasdegib + LDAC arm and 4.3 months (95% CI: 1.9, 5.7) for the LDAC alone arm and HR of 0.46 (95% CI: 0.30, 0.71; p=0.0002).
Glasdegib was granted priority review and orphan drug designation by the U.S. Food and Drug Administration (FDA). It was granted orphan drug designation by the European Medicines Agency (EMA) in October 2017.
Glasdegib was approved for medical use in the European Union in June 2020.
References
External links
Antineoplastic drugs
Benzimidazoles
Nitriles
Orphan drugs
Drugs developed by Pfizer
Piperidines
Teratogens
Ureas | Glasdegib | [
"Chemistry"
] | 656 | [
"Functional groups",
"Organic compounds",
"Teratogens",
"Nitriles",
"Ureas"
] |
52,923,904 | https://en.wikipedia.org/wiki/Karyorelict%20nuclear%20code | The karyorelictid nuclear code (translation table 27) is a genetic code used by the nuclear genome of the Karyorelictea ciliate Parduczia sp. This code, along with translation tables 28 and 31, is remarkable in that every one of the 64 possible codons can be a sense codon. Translation termination probably relies on context, specifically proximity to the poly(A) tail.
The code (27)
AAs = FFLLSSSSYYQQCCWWLLLAPPPPHHQQRRRRIIIMTTTTNNKKSSRRVVVVAAAADDEEGGGG
Starts = --------------*--------------------M----------------------------
Base1 = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG
Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG
Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), and Valine (Val, V).
Differences from the standard code
See also
List of all genetic codes: translation tables 1 to 16, and 21 to 31.
The genetic codes database.
References
Molecular genetics
Gene expression
Protein biosynthesis | Karyorelict nuclear code | [
"Chemistry",
"Biology"
] | 580 | [
"Protein biosynthesis",
"Gene expression",
"Molecular genetics",
"Biosynthesis",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
52,925,755 | https://en.wikipedia.org/wiki/C21H29ClO3 | {{DISPLAYTITLE:C21H29ClO3}}
The molecular formula C21H29ClO3 (molar mass: 364.90616 g/mol) may refer to:
Clogestone, or chlormadinol
Clostebol acetate
Hydromadinone
Molecular formulas | C21H29ClO3 | [
"Physics",
"Chemistry"
] | 69 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
52,926,101 | https://en.wikipedia.org/wiki/G-10%20%28material%29 | G-10 or garolite is a high-pressure fiberglass laminate, a type of composite material. It is created by stacking multiple layers of glass cloth, soaked in epoxy resin, then compressing the resulting material under heat until the epoxy cures. It is manufactured in flat sheets, most often a few millimeters thick.
G-10 is very similar to Micarta and carbon fiber laminates, except that glass cloth is used as filler material. (Note that the professional nomenclature of "filler" and "matrix" in composite materials may be somewhat counterintuitive when applied to soaking textiles with resin.)
G-10 is the toughest of the glass fiber resin laminates and therefore the most commonly used.
Properties
G-10 is favored for its high strength, low moisture absorption, and high level of electrical insulation and chemical resistance. These properties are maintained not only at room temperature but also under humid or moist conditions. It was first used as a substrate for printed circuit boards, and its designation, G-10, comes from a National Electrical Manufacturers Association standard for this purpose.
Decorative uses
Decorative variations of G-10 are produced in many colors and patterns and are especially used to make handles for knives, grips for firearms and other tools. These can be textured (for grip), bead blasted, sanded or polished. Its strength and low density make it useful for other kinds of handcrafting as well.
Structural uses
G-10 is used to reinforce the edges of fiberglass coated wood. It is used to protect the point-of-contact on many such items. During ordinary use it is the G-10 that takes the brunt of the blow. In such applications it is meant to be replaced as it wears. G-10 is also used as a 3D-Printer build surface.
G-10 is also commonly used as a material for durable knife and gun handles and grips.
Hazards
G-10 is safe to handle absent extreme conditions.
Hazards can result from cutting or grinding the material, as glass and epoxy dust are well known to contribute to respiratory disorders and may increase the risk of developing lung cancer. For any work of this kind, the work space should be appropriately ventilated and masks or respirators worn.
Epoxy resin is flammable and, once ignited, will burn vigorously, giving off poisonous gases. For this reason, materials such as FR-4 containing flame retardant additives have replaced G-10 in certain applications.
See also
Bakelite
References
Printed circuit board manufacturing
Fibre-reinforced polymers
Fiberglass | G-10 (material) | [
"Chemistry",
"Materials_science",
"Engineering"
] | 533 | [
"Fiberglass",
"Electronic engineering",
"Polymer chemistry",
"Electrical engineering",
"Printed circuit board manufacturing"
] |
52,926,103 | https://en.wikipedia.org/wiki/Histone%20Database | The Histone Database is a comprehensive database of histone protein sequences including histone variants, classified by histone types and variants, maintained by National Center for Biotechnology Information. The creation of the Histone Database was stimulated by the X-ray analysis of the structure of the nucleosomal core histone octamer followed by the application of a novel motif searching method to a group of proteins containing the histone fold motif in the early-mid-1990. The first version of the Histone Database was released in 1995 and several updates have been released since then.
Current version of the Histone Database - HistoneDB 2.0 - with variants - includes sequence and structural annotations for all five histone types (H3, H4, H2A, H2B, H1) and major histone variants within each histone type. It has many interactive tools to explore and compare sequences of different histone variants from various organisms. The core of the database is a manually curated set of histone sequences grouped into 30 different variant subsets with variant-specific annotations. The curated set is supplemented by an automatically extracted set of histone sequences from the non-redundant protein database using algorithms trained on the curated set. The interactive web site supports various searching strategies in both datasets: browsing of phylogenetic trees; on-demand generation of multiple sequence alignments with feature annotations; classification of histone-like sequences and browsing of the taxonomic diversity for every histone variant.
References
Proteins
Protein databases | Histone Database | [
"Chemistry"
] | 311 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
52,926,238 | https://en.wikipedia.org/wiki/Tetradentate%20ligand | In chemistry, tetradentate ligands are ligands that bind four donor atoms to a central atom to form a coordination complex. This number of donor atoms that bind is called denticity and is a method of classifying ligands.
Tetradentate ligands are common in nature in the form of chlorophyll, which has a core ligand called chlorin, and heme, which has a core ligand called porphyrin. They are responsible for the colour observed in plants and humans. Phthalocyanine is an artificial macrocyclic tetradentate ligand that is used to make blue and green pigments.
Shape
Tetradentate ligands can be classified by the topology of the connections between donor atoms. Common forms are linear (also called sequential), ring or tripodal. A tetrapodal ligand that is also tetradentate has four legs with donor atoms and a bridgehead that is not a donor. Upon binding with a central atom, there are several arrangements possible (known as geometric isomers).
Linear ligands
A linear tetradentate ligand has the four donor atoms in a line and each subsequent donor is connected by one of three bridges. Such a ligand bound to a metal in tetrahedral coordination can only connect in one way, though if the ligand is unsymmetrical then there are two chiral arrangements. A linear tetradentate ligand can also bind to a metal in square planar coordination in one way, where anticlockwise or clockwise arrangements are equivalent.
Linear ligands in octahedral coordination
A linear tetradentate ligand has its donor atoms arranged along or in a chain so that each adjacent donor atom has to be adjacent on the central atom. This arrangement leads to three stereochemical outcomes, and the four donor groups can be co-equatorial. This geometry is called trans because the remaining unoccupied positions on the octahedron are mutually trans (opposite). When the two internal donor atoms are pyramidal (such as the secondary amines in trien or EDDA), two diastereomers for the trans arrangement are determined by the relative stereochemistry of these centers. Typically these donors are mutually trans, resulting in a chiral complex of C2-symmetric complexes. This arrangement is illustrated by complexes of the Trost ligand.
The ligand can bend so that one donor atom is at the pole and the remaining three are on the equator of the central atom. This is called cis-β (beta). The remaining octahedral positions are cis (adjacent) to each other. The triangles of coordinating atoms and the central atom have two coplanar atoms, and one perpendicular atom. This arrangement is chiral, so there are two possible mirror images. The arrangement where the chain goes down and clockwise is termed lambda, Λ, and where it goes down and anticlockwise is called delta, Δ. If the chain is not symmetrical, then different isomers can be produced by the end of the ligand that has the bend. If three donor atoms are the same at one end of the chain, the mer- and fac- prefixes used for tridentate ligands can be used. If the three donor atoms are arranged on a meridian, β-mer- is used; if the three donor atoms are arranged on the face of an octahedron, β-fac is used.
The chain can have two bends, with one donor at a pole, two on the equator and one at the opposite pole. None of the triangles of coordinating atoms and the central atom are coplanar. This is termed cis-alpha (α). This arrangement is chiral, so there are two possible mirror images. The arrangement where the chain goes down and clockwise and down is termed lambda, Λ, and where is goes down and anticlockwise and down is called delta (Δ).
Tripodal ligands
Tripodal tetradentate ligands have a donor atom connected via three chains to other donor atoms. The top of the tripod is called the apex, and a donor atom in that position is apical, or also known as the bridging atom. The other three donor atoms are on the "feet" of the tripod. Tripodal tetradentate ligands can have three identical chains attached to an atom (such as nitrogen, phosphorus, or arsenic) in tertiary arrangement. Molecules containing phosphorus, or arsenic donor atoms remain stiff at the P or As and can hold their shape, unlike nitrogen compounds which rapidly racemize. If all the feet of the tripod are symmetrical and identical to each other, there will be only one way to attach in an octahedral coordination. However, there are two non-equivalent positions left on the central atom, so if two different monodentate ligands or an unsymmetrical bidentate ligand attaches, there will be two possible isomers. If the feet differ, there are more isomers. When two feet are the same, and one is different there are three arrangements, two of which are enantiomers of each other. When there are three different legs, there are six possible isomers, but two are enantiomers of another pair and two are symmetric.
Atoms with five coordinate positions are usually trigonal bipyramidal or square pyramid geometry. A symmetric tripodal tetradentate ligand can form two isomers on a square pyramid, depending on whether the bridging donor is on the apex or the base of the pyramid. The extra vacant position on the square pyramid is on the base. Square pyramidal coordination tends to occur where a six-member ring is formed with the bridgehead, bridge, feet donor atom and central atom. The longer leg (with three bridging atoms) connects to the apex of the pyramid, and symmetry is lost.
For the trigonal bipyramid, the tripod shaped ligand has its most symmetrical position with the bridging donor at one of the apexes, and the feet of the tripod are arranged around the base, leaving a vacant position at the opposite apex, resulting in C3v symmetry. Trigonal bipyramidal coordination tends to occur where five member rings are formed with the bridgehead, bridge, feet donor atoms and central atom.
In four coordination a tripodal ligand would fill all the positions available, the geometry is trigonal pyramid. The shape is distorted from the tetrahedron due to the non-symmetry of the tripod.
Classification
In addition to shape, tetradentate ligands can be classified by the ligating atoms on the ligand. For linear ligands the order can be given. The ligand may have a negative charge when it is in a complex with the central atom. This may develop through the loss of hydrogen ions when the substance is dissolved.
One further characteristic is the size of the rings formed by the central metal with two donor atoms and the intervening chain of the ligand. Usually these rings have five or six members, but sometimes seven atoms. For ring shaped ligands, the total number of atoms in the ring is important, as it is a determiner of the hole size for the central atom. Each additional atom in the ring enlarges the hole radius from 0.1 to 0.15 Å.
Ligands are also characterized by charge. Tetradentate ligands can be neutral so that the charge of the whole complex is the same as the central atom. A tetradentate monoanionic (TMDA) ligand has one donor atom with a negative charge. A tetradentate dianionic ligand has a double negative charge, and tetradentate trianionic ligands have a triple negative charge. The maximal charge is on tetradentate tetraanionic ligands, which can stabilize metals in high oxidation states, however such ligands also have to resist oxidation by the highly oxidizing metal centre.
List
Biomolecules
Heme is a heterocyclic macrocycle ring shaped tetradentate ligand. It is an important molecule in red blood cells.
Chlorophyll comes in several forms and is important in plant photosynthesis. Bacteria may use variants called bacteriochlorophylls.
References
Ligands
Tetradentate ligands | Tetradentate ligand | [
"Chemistry"
] | 1,707 | [
"Ligands",
"Coordination chemistry"
] |
52,926,589 | https://en.wikipedia.org/wiki/Polycentric%20networks | In public policy a polycentric network is a group of distinct local, regional, or national entities that work co-operatively towards a common goal. Proponents claim that such networks can better adapt to changing issues collectively than individually, thus providing network participants better results from relevant efforts.
Urban contexts
Robert Kloosterman and Bart Lambregts define polycentric urban regions as collections of historically distinct jurisdictions that are administratively and politically independent. These jurisdictions are in close proximity and well connected through infrastructure. The literature on polycentric urban regions is limited and unconsolidated, so diverse concepts exist. Evert Meijers claimed that polycentric network are especially prominent in Europe.
Rural polycentric networks are nearly non-existent. Urban polycentric networks draw heavily on economic network theories. According to Meijers, “individual cities in these collections of distinct but proximally-located cities relate to each other in a synergetic way, making the whole network of cities more than the sum of its parts”.
Implementation
Polycentric networks have different spatial characteristics, reflecting a micro, meso, or macro-level of connections in a given region. These different scales allow flexible and convertible networks for spatial planning in complex regions and systems.
Micro-level: intra-urban or intra-regional aspects within a certain city region. The emphasis at this level is “urban functional and economic complementarities” which make “cooperation and improved links” major engines of regional economic performance and “promote integrated spatial development strategies for city clusters”.
Meso-level: inter-metropolitan issues within a delimited area. The emphasis at this level is very similar to the micro-level, with added specialization.
Macro-level: inter-metropolitan issues on a continental or global scale. At the macro level polycentricism is considered to be “a useful alternative model to enhance regional development more evenly across the European territory”.
Metropolitan areas
In metropolitan areas, the scale and intensity of collaboration is a key determinant of whether or not polycentric networks function properly. Metropolitan planning organizations (MPOs) have given researchers a unique opportunity to study the scale and intensity of collaboration. A 2015 study of 381 MPOs in the United States, found a direct link between the MPO's scale and performance. The study concluded that more intense MPO collaboration across both vertical and horizontal stakeholders improved performance. The study found that MPOs that focused more on vertical collaboration (between the state and higher-up agencies) saw a decrease in their perceived performance. The study looked at 15 indicators including condition of transportation network, mobility for disadvantaged populations, air quality, highway congestion, public participation, extent of coordination and stakeholder involvement, satisfaction among general public, satisfaction among local stakeholders, compliance with federal and state rules, transportation systems security, accessibility, reliability, and safety, travel demand model accuracy and project implementation.
Future polycentric networks
Researcher Perry Yang claimed that the future for polycentric networks lies in sustainability. Yang conducted research in Singapore around cities' push for greater sustainability. With globalization and the separation of land come split ecosystems and habitat changes to build infrastructure for human development. A big issue for sustainability is how to minimize human environmental impact while thriving as a species.
Yang’s research explored Singapore's growth over time. He noted that this growth was largely industrial and revolved around rapid mass transit (MRT), which connects areas of the island. The general shift seen in Singapore can be seen as the impact of polycentric networks throughout the island with the implementation of rezoning policies. From 1986 to 1994, much rezoning occurred due to changes in land use policy. Yang found that transit and raw materials are central to growth in rapidly developing areas and argued that Singapore is a good example of a polycentric urban form, but may not be adequate to establish an urban sustainability model.
See also
Economics of networks
Supply chain collaboration
References
Networks
Urban planning in Singapore
Natural resource management
Transport and the environment
Zoning
Metropolitan areas
Community development
Environmental impact assessment
Economic integration
Cityscapes
Travel
Spatial planning
Urban planning | Polycentric networks | [
"Physics",
"Engineering"
] | 817 | [
"Travel",
"Transport and the environment",
"Zoning",
"Physical systems",
"Transport",
"Construction",
"Urban planning",
"Architecture"
] |
52,926,775 | https://en.wikipedia.org/wiki/Minimum%20bias%20event | Minimum bias (MB) events are inelastic events selected by a high-energy experiment's loose (minimum bias) trigger with as little bias as possible. MB events can include both non-diffractive and diffractive processes although the precise definition and relative contributions vary among experiments and analyses. Quite often the beam hadrons ooze through each other and fall apart without any hard collisions occurring in the event. MB event is not the same as the underlying event (UE), which consists of particles accompanying a hard scattering. The density of particles in the UE in jet events is found to be roughly a factor of two greater than that in MB in proton-proton collisions at the Tevatron and the LHC.
References
Particle physics
Scattering
Large Hadron Collider | Minimum bias event | [
"Physics",
"Chemistry",
"Materials_science"
] | 161 | [
"Condensed matter physics",
"Scattering",
"Particle physics",
"Nuclear physics"
] |
42,748,548 | https://en.wikipedia.org/wiki/Hellenophilia | Hellenophilia is the idea that all western science began in Greek tradition. This is discussed in length by David Pingree in his address to colleagues. Hellenophilia is a way of thought that allows those who look into the history of science to be blinded to science born in other cultures. Pingree states, in explanation of the term that "a Hellenophile suffers from a form of madness that blinds him or her to historical truth" (Pingree, 1992, p. 554) He continues by explaining the main symptoms of Hellenophilia "the first of these is that the Greeks invented science; the second is that they discovered a way to truth, the scientific method, that we are now successfully following; the third is that the only real sciences are those that began in Greece; and the fourth (and last?) is that the true definition of science is just that which scientists happen to be doing now, following a method or methods adumbrated by the Greeks, but never fully understood or utilized by them" (Pingree, 1992, p. 555).
An anthropological etiology of Greek innovation in natural science is advanced by sociologist Michael G. Horowitz in "The Scientific Dialectic of Ancient Greece and the Cultural Tradition of Indo-European Speakers" (Journal of Indo-European Studies, 24(3-4):409-19 [1996]).
Although Hellenophilia relates directly to the history of science, it is important to look at it through aspects of history that lend to the habit, other than the symptoms listed by Pingree. One of these habits, as described by David C. Lindberg is looking at the history of science as starting with writing in fully syllabic systems. According to Lindberg the beginning of syllabic writing was around 1500 B.C. However, fully alphabetic writing was apparent in Greece in 800 B.C. (Linberg, 2007, p. 10).
References
Admiration of foreign cultures
Greek nationalism
History of science | Hellenophilia | [
"Technology"
] | 410 | [
"History of science",
"History of science and technology"
] |
42,748,943 | https://en.wikipedia.org/wiki/NGC%2067 | NGC 67 is an elliptical galaxy located in the constellation Andromeda that was discovered on October 7, 1855, by R. J. Mitchell, who described it as "extremely faint, very small, round". The galaxy belongs to the NGC 68 group, which also contains the galaxies NGC 68, NGC 69, NGC 70, NGC 71, NGC 72, and possibly NGC 74.
Target galaxy controversy
Mitchell's position locates the observed galaxy between an E3 elliptical and an E5 elliptical on the edge of the galaxy group, and each elliptical has been interpreted as the original and secondary. Wikisky lists the round galaxy as the primary and the elongated as PGC 138159, the Deep-Sky Objects browser lists the elongated as NGC 67, NED lists the same galaxy as both NGC 67 and NGC 67a. Courtney Seligman's NGC object database argues, however, that since the location offset of NGC 67 is similar to that of the other galaxies in the group, that the elongated galaxy is likely the observed object, and that the rounder NGC 67a was listed as a star by Mitchell.
References
External links
0067
01185
Elliptical galaxies
18551007
Andromeda (constellation) | NGC 67 | [
"Astronomy"
] | 247 | [
"Andromeda (constellation)",
"Constellations"
] |
42,753,276 | https://en.wikipedia.org/wiki/Bougainvillea%20%C3%97%20buttiana | Bougainvillea × buttiana is a flowering plant, a garden hybrid of Bougainvillea glabra and Bougainvillea peruviana.
Growing to tall by broad, It is an evergreen vine, with thorny stems and tiny trumpet shaped white flowers, usually appearing in clusters surrounded by three showy bright magenta-rose papery bracts. The leaves are ovate and dark green.
This plant can be grown in a warm temperate or subtropical environment where the temperature does not fall below freezing (), against a south-facing wall in full sun. Numerous cultivars have been developed, of which the following have gained the Royal Horticultural Society's Award of Garden Merit:
'Miss Manila'
'Mrs Butt'
'Poulton's Special'
References
External links
Birmingham botanical gardens
Nyctaginaceae
Hybrid plants | Bougainvillea × buttiana | [
"Biology"
] | 172 | [
"Hybrid plants",
"Plants",
"Hybrid organisms"
] |
42,753,284 | https://en.wikipedia.org/wiki/Rakut%20Sitelu | Rakut Sitelu is a kinship system of the Karo people of Indonesia. There are three titles in the rakut sitelu, namely kalimbubu (bride´s family), sembuyak or senina (parents), and anak beru (groom´s family).
References
Karo people
Kinship and descent | Rakut Sitelu | [
"Biology"
] | 71 | [
"Behavior",
"Human behavior",
"Kinship and descent"
] |
42,753,316 | https://en.wikipedia.org/wiki/Main%20theorem%20of%20elimination%20theory | In algebraic geometry, the main theorem of elimination theory states that every projective scheme is proper. A version of this theorem predates the existence of scheme theory. It can be stated, proved, and applied in the following more classical setting. Let be a field, denote by the -dimensional projective space over . The main theorem of elimination theory is the statement that for any and any algebraic variety defined over , the projection map sends Zariski-closed subsets to Zariski-closed subsets.
The main theorem of elimination theory is a corollary and a generalization of Macaulay's theory of multivariate resultant. The resultant of homogeneous polynomials in variables is the value of a polynomial function of the coefficients, which takes the value zero if and only if the polynomials have a common non-trivial zero over some field containing the coefficients.
This belongs to elimination theory, as computing the resultant amounts to eliminate variables between polynomial equations. In fact, given a system of polynomial equations, which is homogeneous in some variables, the resultant eliminates these homogeneous variables by providing an equation in the other variables, which has, as solutions, the values of these other variables in the solutions of the original system.
A simple motivating example
The affine plane over a field is the direct product of two copies of . Let
be the projection
This projection is not closed for the Zariski topology (nor for the usual topology if or ), because the image by of
the hyperbola of equation is which is not closed, although is closed, being an algebraic variety.
If one extends to a projective line the equation of the projective completion of the hyperbola becomes
and contains
where is the prolongation of to
This is commonly expressed by saying the origin of the affine plane is the projection of the point of the hyperbola that is at infinity, in the direction of the -axis.
More generally, the image by of every algebraic set in is either a finite number of points, or with a finite number of points removed, while the image by of any algebraic set in is either a finite number of points or the whole line It follows that the image by of any algebraic set is an algebraic set, that is that is a closed map for Zariski topology.
The main theorem of elimination theory is a wide generalization of this property.
Classical formulation
For stating the theorem in terms of commutative algebra, one has to consider a polynomial ring over a commutative Noetherian ring , and a homogeneous ideal generated by homogeneous polynomials (In the original proof by Macaulay, was equal to , and was a polynomial ring over the integers, whose indeterminates were all the coefficients of the)
Any ring homomorphism from into a field , defines a ring homomorphism (also denoted ), by applying to the coefficients of the polynomials.
The theorem is: there is an ideal in , uniquely determined by , such that, for every ring homomorphism from into a field , the homogeneous polynomials have a nontrivial common zero (in an algebraic closure of ) if and only if
Moreover, if , and is principal if . In this latter case, a generator of is called the resultant of
Hints for a proof and related results
Using above notation, one has first to characterize the condition that do not have any non-trivial common zero. This is the case if the maximal homogeneous ideal is the only homogeneous prime ideal containing Hilbert's Nullstellensatz asserts that this is the case if and only if contains a power of each or, equivalently, that for some positive integer .
For this study, Macaulay introduced a matrix that is now called Macaulay matrix in degree . Its rows are indexed by the monomials of degree in and its columns are the vectors of the coefficients on the monomial basis of the polynomials of the form where is a monomial of degree One has if and only if the rank of the Macaulay matrix equals the number of its rows.
If , the rank of the Macaulay matrix is lower than the number of its rows for every , and, therefore, have always a non-trivial common zero.
Otherwise, let be the degree of and suppose that the indices are chosen in order that The degree
is called Macaulay's degree or Macaulay's bound because Macaulay's has proved that have a non-trivial common zero if and only if the rank of the Macaulay matrix in degree is lower than the number to its rows. In other words, the above may be chosen once for all as equal to .
Therefore, the ideal whose existence is asserted by the main theorem of elimination theory, is the zero ideal if , and, otherwise, is generated by the maximal minors of the Macaulay matrix in degree .
If , Macaulay has also proved that is a principal ideal (although Macaulay matrix in degree is not a square matrix when ), which is generated by the resultant of This ideal is also generically a prime ideal, as it is prime if is the ring of integer polynomials with the all coefficients of as indeterminates.
Geometrical interpretation
In the preceding formulation, the polynomial ring defines a morphism of schemes (which are algebraic varieties if is finitely generated over a field)
The theorem asserts that the image of the Zariski-closed set defined by is the closed set . Thus the morphism is closed.
See also
Elimination of quantifiers
Macaulay's resultant
Gröbner basis
References
Algebraic geometry | Main theorem of elimination theory | [
"Mathematics"
] | 1,106 | [
"Theorems in algebraic geometry",
"Theorems in geometry"
] |
42,753,823 | https://en.wikipedia.org/wiki/Earthquake%20environmental%20effects | Earthquake environmental effects are the effects caused by an earthquake, including surface faulting, tsunamis, soil liquefactions, ground resonance, landslides and ground failure, either directly linked to the earthquake source or provoked by the ground shaking.
These are common features produced both in the near and far fields, routinely recorded and surveyed in recent events, very often remembered in historical accounts and preserved in the stratigraphic record (paleo earthquakes). Both surface deformation and faulting and shaking-related geological effects (e.g., soil liquefaction, landslides) not only leave permanent imprints in the environment, but also dramatically affect human structures. Moreover, underwater fault ruptures and seismically triggered landslides can generate tsunami waves.
EEE represent a significant source of hazard, especially (but not exclusively) during large earthquakes. This was observed for example during more or less catastrophic seismic events recently occurred in very different parts of the world.
Earthquake environmental effects are divided into two main types:
Primary effects: which are the surface expression of the seismogenic source (e.g., surface faulting), normally observed for crustal earthquakes above a given magnitude threshold (typically =5.5–6.0);
Secondary effects: mostly this is the intensity of the ground shaking (e.g., landslides, liquefaction, etc.).
The importance of a tool to measure earthquake Intensity was already outlined early in the 1990s. In 2007 the Environmental Seismic Intensity scale (ESI scale) was released, a new seismic intensity scale based only on the characteristics, size and areal distribution of earthquake environmental effects.
A huge amount of data about associated with modern, historical and paleoearthquakes worldwide, an infrastructure developed in the framework of the INQUA TERPRO Commission on Paleoseismology and Active Tectonics.
See also
Earthquake light
Electromagnetic field
Richter scale
References
External links
INQUA TERPRO Commission on Paleoseismology and Active Tectonics
Earthquake engineering | Earthquake environmental effects | [
"Engineering"
] | 407 | [
"Earthquake engineering",
"Civil engineering",
"Structural engineering"
] |
42,754,539 | https://en.wikipedia.org/wiki/X%20Centauri | x Centauri can refer to two different stars:
x1 Centauri, HR 4712
x2 Centauri, HR 4724
See also
χ Centauri
Centaurus
Centauri, x | X Centauri | [
"Astronomy"
] | 44 | [
"Centaurus",
"Constellations"
] |
42,754,799 | https://en.wikipedia.org/wiki/NGC%2068 | NGC 68 is a lenticular galaxy, and the central member of the NGC 68 group, in the constellation Andromeda. The galaxy was discovered on September 11, 1784, by William Herschel, who observed the NGC 68 group as a single object and described it as "extremely faint, large, 3 or 4 stars plus nebulosity". As such, his reported location is between NGC 68, NGC 70, and NGC 71. By the time Dreyer looked at the galaxies to add to the NGC catalog, however, he was able to tell that the single galaxy observed by Herschel was in fact 3 adjacent galaxies, and cataloged them as NGC 68, NGC 70, and NGC 71.
References
External links
0068
01187
00170
+05-01-065
Lenticular galaxies
17840911
Andromeda (constellation)
Discoveries by William Herschel | NGC 68 | [
"Astronomy"
] | 180 | [
"Andromeda (constellation)",
"Constellations"
] |
42,754,865 | https://en.wikipedia.org/wiki/Teri%20W.%20Odom | Teri W. Odom is an American chemist and materials scientist. She is the chair of the chemistry department, the Joan Husting Madden and William H. Madden, Jr. Professor of Chemistry, and a professor of materials science and engineering at Northwestern University. She is affiliated with the university's International Institute for Nanotechnology, Chemistry of Life Processes Institute, Northwestern Initiative for Manufacturing Science and Innovation, Interdisciplinary Biological Sciences Graduate Program, and department of applied physics.
Education
Odom attended Stanford University, where she earned a BS in chemistry, was elected to Phi Beta Kappa, and received the Standford's Marsden Memorial Prize for Chemistry Research (1996). She obtained her PhD in chemical physics from Harvard University in 2001 under the guidance of Charles M. Lieber, then conducted post-doctoral research at Harvard with George M. Whitesides from 2001 to 2002.
Career
Odom joined Northwestern University's department of chemistry in 2002 and became the department chair in 2018. In 2010, she became the founding chair of the Noble Metal Nanoparticles Gordon Research Conference Between 2016 and 2018, she was associate director of the International Institute for Nanotechnology. Odom has worked on the editorial advisory boards of ACS Nano, Bioconjugate Chemistry, Materials Horizons, Annual Review of Physical Chemistry Natural Sciences, Nano Futures, and Accounts of Chemical Research. Odom became an inaugural associate editor for Royal Society of Chemistry's Chemical Science journal in 2009, a position she held until 2013. She was on the editorial advisory board of Nano Letters beginning in 2010 and became editor-in-chief in 2019. In 2013, she became a founding Executive Editor for ACS Photonics.
Research interests
Research in the Odom group focus on controlling materials at 100 nm scale and investigating their size and shape-dependent properties. Odom group has developed parallel, multi-scale pattering tools to generate hierarchical, anisotropic, and 3D hard and soft materials with applications in imaging, sensing, wetting and cancer therapeutics. As a result of Odom's nanofabrication tools, she has developed flat optics that can manipulate light at the nanoscale and beat the diffraction limit and tunable plasmon-based lasers. Odom also conducts research into nanoparticle-cell interactions using new biological nanoconstructs that offer imaging and therapeutic functions due to their shape (gold nanostar).
Personal life
Odom's husband Brian, now a physicist and astronomer at Northwestern University, piqued her interest in science by introducing her to the double-slit experiment while they were dating. He encouraged her to pursue undergraduate summer research, an experience that inspired her to continue studying physics and chemistry.
Awards and recognition
1996-1999 - National Science Foundation Predoctoral Fellow, Harvard University
2001 - International Union of Pure and Applied Chemistry Young Chemists award for thesis
2001-2002 - National Research Service Award Postdoctoral Fellow, Harvard University
2002 - Research Corporation's Research Innovation Award
2002 - Dow Teacher-Scholar Award, inaugural recipient
2003 - American Chemical Society's Victor K. LaMer Award
2003 - David and Lucile Packard Foundation Fellow
2004 - National Science Foundation CAREER Award
2004 - MIT Technology Review Top 100 Innovators
2005 - Cottrell Scholar Award
2005 - DuPont Young Investigator Award
2005 - Alfred P. Sloan Research Fellow
2006 - ExxonMobil Solid State Chemistry Faculty Fellow
2007 - Rohm and Haas New Faculty Award
2008 - Phi Lambda Upsilon's National Fresenius Award
2008 - National Institutes of Health Director's Pioneer Award
2009 - Materials Research Society Outstanding Young Investigator Award
2010 - Institute for Defense Analyses's Defense Sciences Study Group (one year)
2011 - Radcliffe Institute for Advanced Study Fellow, Harvard University
2014 - Royal Society of Chemistry Fellow
2014 - Blavatnik Awards for Young Scientists Finalist
2014 - International Precious Metals Institute's Carol Tyler Award
2016 - Materials Research Society Fellow
2016 - Blavatnik Awards for Young Scientists Finalist
2017 - ACS Nano Lectureship Award
2017 - United States Department of Defense Vannevar Bush Faculty Fellow
2018 - American Physical Society Fellow
2018 - Research Corporation Cottrell Scholar TREE Award
2018 - Optica Senior Member
2020 - Royal Society of Chemistry's Centenary Prize
2020 - American Academy of Arts and Sciences Fellow
2020 - American Chemical Society's Award in Surface Chemistry
2022 - American Institute for Medical and Biological Engineering Fellow
2022 - American Chemical Society's Crano Memorial Lecture (Akron Section) at Malone University
2022 - American Association for the Advancement of Science Fellow
References
External links
Northwestern Chemistry Faculty bio
The Odom Research Group
Living people
21st-century American chemists
American materials scientists
Northwestern University faculty
Stanford University alumni
Harvard University alumni
American women chemists
Women materials scientists and engineers
1970s births
American women academics
Solid state chemists
21st-century American women scientists
Fellows of the American Physical Society
Nanophysicists
American nanotechnologists
Sloan Research Fellows
Radcliffe fellows
Fellows of the Royal Society of Chemistry
Fellows of the American Academy of Arts and Sciences
Fellows of the American Institute for Medical and Biological Engineering
Fellows of the American Association for the Advancement of Science | Teri W. Odom | [
"Chemistry",
"Materials_science",
"Technology"
] | 1,027 | [
"Solid state chemists",
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
42,756,061 | https://en.wikipedia.org/wiki/Cycada%20%28compatibility%20layer%29 | Cycada (formerly known as Cider, and Chameleon before) is a compatibility layer that aims to allow applications designed for iOS to run unmodified on the Android operating system. The method uses compile-time adaptation to run unmodified code with minimal implementation effort.
The project was revealed in a conference paper by computer science researchers at Columbia University. The project enables iOS applications to adapt to Android's kernel and programming libraries.
A video released shows that many applications work, including the iOS version of Yelp, Apple's iBooks software and 3D benchmarks using OpenGL. Consequent to the release of the white paper, hardware GPS support was added to the software.
Unlike many other compatibility layers (such as WINE or Darling), Cycada works at the kernel level, as opposed to at user space.
Cycada is not a simple APK file, and modifies the entire Linux kernel.
It is unknown whether the project will be released.
The original name “Cider” was most likely a play on WINE, another compatibility layer named after an alcoholic drink.
Since lead developer Jeremy Andrus left for a job on the Darwin kernel at Apple, the project has been headed by Jason Nieh. Work on the project has still continued following this related to graphics in 2017.
Similar projects
In December of 2022, Internet user Martijn de Vos, also known as devos50 has reverse engineered this device to successfully create a QEMU emulation of this device, running iPhone OS 1.0.
touchHLE is a compatibility layer (referred to as a “high-level emulator”) for Windows and macOS made by Andrea "hikari_no_yume" in early 2023. The emulator was only able to run one software, Super Monkey Ball. She says that fans will have to "be patient" for anything else to emulate. It uses code translation along with CPU emulation when necessary, and specifically stated that she does not want to be compatible with 64 bit software.
ipasim is a compatibility layer that provides native execution for iOS apps to run on Windows based on code translations and WinObjC.
QEMU-t9080, also known as TruEmu is an iPhone 11 emulated in QEMU for the purpose of security research and cannot boot past the Apple Logo.
Notes
1.Cider is an alcoholic drink made from apples.
See also
WinObjC
References
Compatibility layers
Computing platforms
Free system software
Linux emulation software
2014 software | Cycada (compatibility layer) | [
"Technology"
] | 519 | [
"Mobile software stubs",
"Mobile technology stubs",
"Computing platforms"
] |
42,756,265 | https://en.wikipedia.org/wiki/Multiscale%20tomography | Multiscale tomography (or multi-length scale tomography) is a form of tomography spanning large orders of magnitude in resolution, often utilizing many different forms of tomography together to do so. The forms of tomography combined in the process depend on what is being studied and the details needed. Each form of tomography has an optimal range of optical resolution that it can function across, but many modern materials and applications need information beyond the range of a single form of tomography. Combining this information using many forms of tomography can help provide a holistic view of the system being looked at, and is important for computer simulations.
References
Tomography
Microscopy
X-ray computed tomography
Synchrotron-related techniques
Electron microscopy | Multiscale tomography | [
"Chemistry"
] | 149 | [
"Electron",
"Electron microscopy",
"Microscopy"
] |
42,756,649 | https://en.wikipedia.org/wiki/Bring%20your%20own%20operating%20system | Bring your own operating system (BYOOS) or Bring Your Own Image (BYOI) relates to the practice of providing PC computers, usually without internally installed disks, so users can bring their own operating system (commonly on USB pen drives) and use the supplied hardware with the operating system of their choice.
BYOOS has been made possible thanks to the ability to create USB pen drives and other external storage devices with 'live' operating system images containing all the necessary drivers to allow boot up and operation on any compatible computer.
Bootable versions of Linux were available by 1993. In 2012, Microsoft Windows 8 Enterprise Edition followed, by introduced Windows To Go functionality to allow the operating system to boot and run from mass storage devices such as USB flash drives thus enabling BYOOS in the Windows family of operating system similar to that of a Linux live CD/DVD.
By allowing users to bring their own operating system there are significant cost savings to be made by organisations who commonly have many on-site users and are obliged to provide them with computer hardware to allow them to perform specific tasks as there is no longer a need to install a hard drive in each computer. Upgrading and maintaining many PC computers has also become easier as companies only need to supply users with new pen drives containing the operating system boot images rather than having to re-image every PC with the latest build of the operating system thus eliminating upgrade costs.
As users can take the USB devices containing their version of the operating system around with them employees can boot up their home computer with the same USB stick so it has exactly the same software environment as they use in their place of work thus enabling employees to work at home exactly the same as they would in the office.
The introduction of cloud based storage, means portable operating systems are free of the need to store data locally. The unbundling of the office application data and other user data from the drives containing the operating systems has been a key factor in making BYOOS possible.
References
See also
BYOD
System administration
Operating system technology | Bring your own operating system | [
"Technology"
] | 408 | [
"Information systems",
"System administration"
] |
54,246,896 | https://en.wikipedia.org/wiki/Stem%20cell%20secretome | The stem cell secretome (also referred to as the stromal cell secretome) is a collective term for the paracrine soluble factors produced by stem cells and utilized for their inter-cell communication. In addition to inter-cell communication, the paracrine factors are also responsible for tissue development, homeostasis and (re-)generation. The stem cell secretome consists of extracellular vesicles, specifically exosomes, microvesicles, membrane particles, peptides and small proteins (cytokines). The paracrine activity of stem cells, i.e. the stem cell secretome, has been found to be the predominant mechanism by which stem cell-based therapies mediate their effects in degenerative, auto-immune and/or inflammatory diseases. Though not only stem cells possess a secretome which influences their cellular environment, their secretome currently appears to be the most relevant for therapeutic use.
Extracellular Vesicles
The Extracellular Vesicles are small partials that are normally discharged and have boundaries that are formed by a lipid bilayer. Although cells can replicate, extracellular vesicle is not able to. In the extracellular vesical, things that consist of the stem cell secretome and are being packed are organelles, mRNA, miRNA, and proteins. Exosomes are discharged from the extracellular vesicles, which are found in biological fluid. Biological fluid like the cerebrospinal fluid, which can be used for treatment. Most impotently, exosomes can be found in between the eukaryotic organism's cell, also known as the tissue matrix.
Research
Stem Cell therapies, here referred to as therapies employing non-hematopoietic, mesenchymal stem cells, have a wide range of potential therapeutic benefits for different diseases, most of which are currently investigated in clinical trials. Stem cell therapies can benefit as a regenerative medicine for patients that have or been diagnosed with disease that affect the mid part of the brain, strokes and heart disease, joint disease and injuries to the spinal cord. Therapeutic properties of stem cells are mainly attributed to their secretome, which has been shown to modulate several biological processes in vitro and in vivo, such as cell proliferation, survival, differentiation, immunomodulation, anti-apoptosis, angiogenesis and stimulation of tissue adjacent cells. This is contrary to the historic hypothesis that stem cell migration and transdifferentiation is the primary mechanism of effect of stem cell injection therapies.
The most commonly used type of stem cells for therapeutic use are human (autologous) Mesenchymal Stem Cells, hMSCs. hMSCs’ secretome is one of the most widely researched secretome profile. The secretomes of other cell types, for example dendritic cells, are also being investigated for therapeutic use.
Studies of hMSCs aimed for examining their regenerative capacities for putative treatment of neurodegenerative diseases have demonstrated that hMSCs are able to secrete important neuroregulatory molecules, such as: brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), insulin growth factor 1 (IGF-1), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-β), glial-derived neurotrophic factor (GDNF), fibroblast growth factor 2 (FGF-2), stem cell factor (SCF), granulocyte colony-stimulating factor (G-CSF) and stromal cell-derived factor (SDF-1) both in vitro and in vivo. All of these molecules have been shown to have beneficial effects towards the treatment of neurodegenerative diseases.
With regard to orthopaedic conditions such as arthritis, the paracrine factors of stem cell-based therapies appeared to be responsible for the majority of regenerative effects. Extracellular vesicles have a prominent role in the development of joints and in the regulation of the intra-articular homeostasis. In the case of arthritis, this homeostasis is disrupted due to different reasons. Hypothetically, one reason may be related to the accumulation of senescent cells and their associated secretory phenotype. The secretome of (mesenchymal) Stem Cells have a positive effects on reestablishing the intra-articular homeostasis and stimulating regeneration by different growth factors, cytokines and miRNA that are contained within the extracellular vesicles of the secretome.
As a consequence, efforts have been made to synthesize specific stem cell secretomes efficiently, in vitro. In general, stem cells become activated and produce higher amounts of secretome in response to external stress (for example, by damaged tissues in vivo). As such, the main preconditioning mechanism to induce secretome (extracellular vesicles) production are stress-inducing methods, most prominently anoxia and hypoxia, but also pharmacological, physical or cytokine-related methods that force the cells to produce secretome in vitro. This approach is also known as cell-free stem cell therapy.
It has been hypothesized that future therapies aiming at generating a (specific) secretome with a defined profile, and optimized concentrations of paracrine factors will yield a better, more reliable and controlled outcome as compared to previous approaches that rely solely on injecting (mesenchymal) stem cells into the body and hope that their paracrine (or trans differentiation) capacity will have beneficial effects in the body. However, the controlled therapeutic use of the stem cell secretome demands high-quality standardization of isolation and analysis techniques to yield reproducible secretome preparations.
Various pharmaceutical companies and clinical institutions have started to develop protocols for the in vitro extraction of specific secretome profiles from autologous mesenchymal stem cells, as well as for the clinical use of secretome as a novel therapeutic for numerous diseases, either as a private pay procedure or within clinical trials. Even though these treatments are in compliance with the regulatory framework in Europe under certain conditions as of May 2017, there is yet no evidence for their proven efficacy in human clinical trials, besides singular case reports. Therefore, at the moment, the clinical use of stem cell secretome is experimental, and it is mainly based on in-vitro and animal data. One potential application of autologous stem cell secretome has been in veterinary medicine, as commercialized by a Russian company, T-Helper Cell Technologies in 2017 under the name Reparin-Helper.
References
Omics
Stem cell research | Stem cell secretome | [
"Chemistry",
"Biology"
] | 1,405 | [
"Stem cell research",
"Bioinformatics",
"Omics",
"Translational medicine",
"Tissue engineering"
] |
54,247,317 | https://en.wikipedia.org/wiki/Appian%20Corporation | Appian Corporation is an American cloud computing and enterprise software company headquartered in McLean, Virginia, part of the Dulles Technology Corridor. The company sells a platform as a service (PaaS) for building enterprise software applications. It is focused on low-code development, process mining, business process management, and case management markets in North America, Europe, the Middle East and Southeast Asia.
History
Founding and early growth: 1999–2013
Appian was founded in 1999 by Michael Beckley, Robert Kramer, Marc Wilson and Matthew Calkins, who is CEO.
In 2001, the company developed Army Knowledge Online, regarded at the time as “the world's largest intranet."
In 2005, the company expanded into financial services and other private markets. It became known for its low-code platform.
In 2010, Appian Cloud was accredited with Federal Information Security Management Act (FISMA) low-level security by the U.S. Education Department. In 2013, it received FISMA Moderate Authorization and Accreditation from the General ices Administration (GSA).
Secondary investments and Nasdaq: 2014–2017
In 2014, the company received $37.5 million in secondary investments from New Enterprise Associates, which was paid out to shareholders. In 2015, transportation company Ryder began using the Appian apps instead of paper processing during the checkout process and internally for truck maintenance records.
On May 25, 2017, Appian became a publicly traded company, trading as APPN on the NASDAQ Global Exchange.
Process mining and artificial intelligence: 2018–present
In May 2019, Appian released Appian AI, enabling artificial intelligence capabilities on its platform. In March 2020, the company updated the platform's Artificial intelligence and robotic process automation capabilities.
In 2022, Appian started highlighting the importance of low-code tools in improving environmental, social & corporate governance (ESG). The company stressed that embedding these tools within operational processes makes it easier for companies to integrate ESG data sources, adapt to regulations, and remain in control of auditability.
In March, Horizon Power, a Western Australian energy utility, wanted to transfer from manual process to automation and started using Appian's low-code platform to improve internal workflows and processes.
April 2022, process mining, first available in January, was fully integrated into all Appian products. This resulted in process mining, low-code/no-code workflows, and automation working as a single solution. That same month, Appian started the free #lowcode4all program to help provide access to low-code education and certification for developers. Participants complete a low-code curriculum and the Appian Certified Associate Developer exam, receive access to hiring recruiters through Appian's partner network, and get job search skills support.
In May 2022, Appian was awarded $2.04 billion in damages against Pegasystems Inc. Pegasystems was found guilty of hiring a developer to spy on Appian, stealing trade secrets in an operation Pegasystems referred to as "Project Crush." Pega is appealing the verdict and the company will not be required to begin paying the judgment until all avenues of appeal have been exhausted. In February 2023, Pega filed an appeal asking the court to overturn the previous judgement and either rule in Pega's favor or order a new trial. March 29, 2023, Appian filed a rebuttal and 8K.
Acquisitions
On January 7, 2020, Appian announced acquisition of Novayre Solutions SL, developer of the Jidoka robotic process automation (RPA) platform.
In August 2021, Appian acquired the process mining company Lana Labs. The company's applications help companies discover the work patterns being used within their organization by looking through system logs for common actions and sequences.
See also
Business process automation
Business process management
Low-code development platform
No-code development platform
References
Information technology companies of the United States
Cloud computing providers
Cloud applications
Enterprise software
Business process management
2017 initial public offerings
Companies listed on the Nasdaq
Companies based in McLean, Virginia
Cloud platforms
Software companies of the United States
Software companies based in Virginia | Appian Corporation | [
"Technology"
] | 846 | [
"Cloud platforms",
"Computing platforms"
] |
54,247,342 | https://en.wikipedia.org/wiki/Zeldovich%20mechanism | Zel'dovich mechanism is a chemical mechanism that describes the oxidation of nitrogen and NOx formation, first proposed by the Russian physicist Yakov Borisovich Zel'dovich in 1946. The reaction mechanisms read as
{N2} + O <->[k_1] {NO} + {N}
{N} + O2 <->[k_2] {NO} + {O}
where and are the reaction rate constants in Arrhenius law. The overall global reaction is given by
{N2} + {O2} <->[k] 2NO
The overall reaction rate is mostly governed by the first reaction (i.e., rate-determining reaction), since the second reaction is much faster than the first reaction and occurs immediately following the first reaction. At fuel-rich conditions, due to lack of oxygen, reaction 2 becomes weak, hence, a third reaction is included in the mechanism, also known as extended Zel'dovich mechanism (with all three reactions),
{N} + {OH} <->[k_3] {NO} + {H}
Assuming the initial concentration of NO is low and the reverse reactions can therefore be ignored, the forward rate constants of the reactions are given by
where the pre-exponential factor is measured in units of cm, mol, s and K (these units are incorrect), temperature in kelvins, and the activation energy in cal/mol; R is the universal gas constant.
NO formation
The rate of NO concentration increase is given by
N formation
Similarly, the rate of N concentration increase is
See also
Zeldovich–Liñán model
References
Combustion
Reaction mechanisms
Chemical reactions
Chemical kinetics
Pollutants | Zeldovich mechanism | [
"Chemistry"
] | 355 | [
"Reaction mechanisms",
"Chemical reaction engineering",
"Combustion",
"nan",
"Physical organic chemistry",
"Chemical kinetics"
] |
54,247,835 | https://en.wikipedia.org/wiki/Biosolarization | Biosolarization is an alternative technology to soil fumigation used in agriculture. It is closely related to biofumigation and soil solarization, or the use of solar power to control nematodes, bacteria, fungi and other pests that damage crops. In solarization, the soil is mulched and covered with a tarp to trap solar radiation and heat the soil to a temperature that kills pests. Biosolarization adds the use of organic amendments or compost to the soil before it is covered with plastic, which speeds up the solarization process by decreasing the soil treatment time through increased microbial activity. Research conducted in Spain on the use of biosolarization in strawberry fruit production has shown it to be a sustainable and cost effective option. The practice of biosolarization is being used among small agricultural operations in California. Biosolarization is a growing practice in response to the need for methods for organic soil solarization. The option for more widespread use of biosolarization is being studied by researchers at the Western Center for Agricultural Health and Safety at the University of California at Davis in order to validate the effectiveness of biosolarization in commercial agriculture in California, where it has the potential to greatly reduce the use of conventional fumigants. Biosolarization can also use as organic waste management practice. Recent studies showed the potential of food industrial residues as soil amendments that can improve the efficiency of biosolarization.
References
Soil science
Soil contamination
Biocides
Pest control techniques
Agricultural terminology | Biosolarization | [
"Chemistry",
"Biology",
"Environmental_science"
] | 312 | [
"Environmental chemistry",
"Biocides",
"Soil contamination",
"Toxicology"
] |
54,247,987 | https://en.wikipedia.org/wiki/Skeletocutis%20microcarpa | Skeletocutis microcarpa is a species of poroid fungus in the family Polyporaceae that is found in Venezuela. It was reported as a new species by mycologists Leif Ryvarden and Teresa Iturriaga. The type collection was made in January 1997, in Yutajé (Amazonas State), where it was found growing on the bark of a living tree. The fruit bodies of this fungus are in the form of small brown caps measuring up to 8 mm wide and long by 4 mm thick. Its spores are smooth, ellipsoid, hyaline, and measure 3–3.3 by 2 μm.
References
Fungi described in 2003
Fungi of Venezuela
microcarpa
Fungus species | Skeletocutis microcarpa | [
"Biology"
] | 151 | [
"Fungi",
"Fungus species"
] |
54,248,271 | https://en.wikipedia.org/wiki/Glow-discharge%20optical%20emission%20spectroscopy | Glow-discharge optical emission spectroscopy (GDOES) is a spectroscopic method for the quantitative analysis of metals and other non-metallic solids. The idea was published and patented in 1968 by Werner Grimm from Hanau, Germany.
Ordinary atomic spectroscopy can be used to determine the surface of a material, but not its layered structure. In contrast, GDOES gradually ablates the layers of the sample, revealing the deeper structure.
GDOES spectroscopy can be used for the quantitative and qualitative determination of elements and is therefore a method of analytical chemistry.
Process
The metallic samples are used as a cathode in a direct current plasma. From the surface, the sample is removed in layers by sputtering with argon ions. The removed atoms pass into the plasma by diffusion. Photons are emitted with excited waves and have characteristic wavelengths which are recorded by means of a downstream spectrometer and subsequently quantified.
When using a high-frequency alternating voltage for plasma generation and the corresponding construction of the glow discharge source, non-metallic samples can also be examined.
Various instruments are used as sensors. Photomultipliers can detect the slightest traces and also high concentrations of the sensor-specific element. By means of charge-coupled device, a complete element spectrum can be measured with the appropriate layer thickness.
Applications
Glow discharge spectroscopy is an established method for the characterization of steels and varnishes. Recent developments relate to the analysis of porous electrodes from lithium-ion batteries.
Further reading
R.Kenneth Marcus, José Broekaert: Glow Discharge Plasmas in Analytical Spectroscopy Wiley,
Thomas Nelis, Richard Payling,: Glow Discharge Optical Emission Spectroscopy - A Practical Guide
References
External links
Glow Discharges, Glow Discharge Laboratory
GDOES Theory with excellent illustrations
Emission spectroscopy | Glow-discharge optical emission spectroscopy | [
"Physics",
"Chemistry"
] | 363 | [
"Emission spectroscopy",
"Spectroscopy",
"Spectrum (physical sciences)"
] |
54,248,486 | https://en.wikipedia.org/wiki/Multivalued%20treatment | In statistics, in particular in the design of experiments, a multi-valued treatment is a treatment that can take on more than two values. It is related to the dose-response model in the medical literature.
Description
Generally speaking, treatment levels may be finite or infinite as well as ordinal or cardinal, which leads to a large collection of possible treatment effects to be studied in applications. One example is the effect of different levels of program participation (e.g. full-time and part-time) in a job training program.
Assume there exists a finite collection of multi-valued treatment status with J some fixed integer. As in the potential outcomes framework, denote the collection of potential outcomes under the treatment J, and denotes the observed outcome and is an indicator that equals 1 when the treatment equals j and 0 when it does not equal j, leading to a fundamental problem of causal inference. A general framework that analyzes ordered choice models in terms of marginal treatment effects and average treatment effects has been extensively discussed by Heckman and Vytlacil.
Recent work in the econometrics and statistics literature has focused on estimation and inference for multivalued treatments and ignorability conditions for identifying the treatment effects. In the context of program evaluation, the propensity score has been generalized to allow for multi-valued treatments, while other work has also focused on the role of the conditional mean independence assumption. Other recent work has focused more on the large sample properties of an estimator of the marginal mean treatment effect conditional on a treatment level in the context of a difference-in-differences model, and on the efficient estimation of multi-valued treatment effects in a semiparametric framework.
References
Applied mathematics
Design of experiments
Statistical theory
Industrial engineering
Systems engineering
Statistical process control
Quantitative research
Experiments
Pharmacodynamics
Toxicology | Multivalued treatment | [
"Chemistry",
"Mathematics",
"Engineering",
"Environmental_science"
] | 370 | [
"Pharmacology",
"Systems engineering",
"Toxicology",
"Statistical process control",
"Pharmacodynamics",
"Applied mathematics",
"Industrial engineering",
"Engineering statistics"
] |
54,248,511 | https://en.wikipedia.org/wiki/Synestia | A synestia is a hypothesized rapidly spinning doughnut-shaped mass of vaporized rock. The term was coined in 2017 by Sarah T. Stewart-Mukhopadhyay, taken from Hestia, goddess of the hearth, combined with syn- meaning together. In computer simulations of giant impacts of rotating objects, a synestia can form if the total angular momentum is greater than the co-rotational limit. Beyond the co-rotational limit, the velocity at the equator of a body would exceed the orbital velocity.
In the case of a synestia, the result is an inner region rotating at a single rate with a loosely connected torus orbiting beyond it. Synestias also have differences in the mantles, both thermally and in their composition, from previous terrestrial evolution models due partially to a lower interior pressure.
Composition
A synestia is composed of three primary components: the innermost area called the corotating region, a middle area called the transition region, and the area farthest out, known as the disk-like region. The corotating region rotates as a solid body. It is characterized by hot vapor and high entropy levels, as well as higher angular velocities.
The transition region is generally a continuous change between the corotating region and ring-like region. Here, in most simulations, the angular velocity and temperature follow a smooth gradient, both decreasing with radius. The temperature gradient is created by the mixture of hot vapor from the inner regions with colder condensed material from farther out. Given time this equilibrates into solely a vapor. This transitions into the disk-like region whose appearance can vary dramatically with different initial conditions for angular momentum, mass, and entropy.
Giant-impact hypothesis
According to studies, synestia was an early-stage process for the formation of the Earth and Moon within the giant-impact hypothesis. In that model, a synestia formed following a collision with an object of high energy and high angular momentum. The synestia's surface temperatures are constrained by the boiling point of rock, around ).
As the resulting synestia cooled by radiating heat to space, magma droplets formed in its outer layers and then rained inward over a period of tens of years, causing the synestia to contract.
Mass remaining outside the Roche limit of the inner region accreted to form moonlets, and subsequently combined to form the Moon. The Earth re-formed later, once the synestia had cooled sufficiently to fall within the co-rotational limit. By this model, the Moon's having formed within a cloud of vapor that originated from the Earth is why its isotopic ratios are similar to those of the Earth. The later formation of the Earth (after the synestia cooled) accounts for its having accreted more volatile elements than the Moon.
Notes and references
External links
Rotation
Types of planet
Hypothetical bodies of the Solar System | Synestia | [
"Physics"
] | 599 | [
"Physical phenomena",
"Astronomical hypotheses",
"Astronomical myths",
"Classical mechanics",
"Rotation",
"Motion (physics)",
"Hypothetical astronomical objects",
"Astronomical objects"
] |
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