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41,420,496 | https://en.wikipedia.org/wiki/Jean-Paul%20Delahaye | Jean-Paul Delahaye (born 29 June 1952 in Saint-Mandé Seine) is a French computer scientist and mathematician.
Career
Delahaye has been a professor of computer science at the Lille University of Science and Technology since 1988 and a researcher in the school's computer sciences lab since 1983. Since 1991 he has written a monthly column in Pour la Science, the French version of Scientific American, dealing with mathematical games and recreations, logic, and computer science. He is a contributing author of the online scientific journal Interstices and a science and mathematics advisor to the Encyclopædia Britannica.
Delahaye won the 1998 d'Alembert prize from the Société mathématique de France for his books and articles popularizing mathematics, especially for the book Le fascinant nombre Pi.
Works
Formal Methods in Artificial Intelligence, North-Oxford Academic, 1987,
Le fascinant nombre pi, Paris: Bibliothèque Pour la Science, 1997,
References
External links
Jean-Paul Delahaye at the Mathematics Genealogy Project
Jean-Paul Delahaye's home page
French mathematicians
French logicians
French computer scientists
Recreational mathematicians
Mathematics popularizers
Combinatorial game theorists
University of Paris alumni
1952 births
Living people
Lille University of Science and Technology alumni
French male non-fiction writers | Jean-Paul Delahaye | [
"Mathematics"
] | 270 | [
"Recreational mathematics",
"Recreational mathematicians"
] |
41,422,644 | https://en.wikipedia.org/wiki/SDSS%20J1106%2B1939 | SDSS J1106+1939 (SDSS J110644.95+193930.6) is a quasar, notable for its energetic matter outflow. It is the record holder for the most powerful matter outflow by a quasar. The engine is a supermassive black hole, pulling in matter at the rate of 400 solar masses per year and ejecting it at the speed of 8000 km/s. The outflow produces a luminosity of 1046 ergs. This makes the quasar more than two trillion times brighter than the Sun, one of the most luminous quasars on record. The quasar has the visual magnitude of about ~19, despite its extreme distance of 11 billion light years. The outflow of matter from the quasar produces about 1/20 of its luminosity.
References
Quasars
Supermassive black holes
SDSS objects
Leo (constellation) | SDSS J1106+1939 | [
"Physics",
"Astronomy"
] | 196 | [
"Black holes",
"Galaxy stubs",
"Unsolved problems in physics",
"Supermassive black holes",
"Astronomy stubs",
"Constellations",
"Leo (constellation)"
] |
41,422,923 | https://en.wikipedia.org/wiki/List%20of%20dust%20storms | This is a list of significant dust storms.
Notes
References
See also
Dust Bowl, a period of severe dust storms in the 1930s affecting the United States and Canada
Dust storms
Weather-related lists | List of dust storms | [
"Physics"
] | 39 | [
"Weather",
"Physical phenomena",
"Weather-related lists"
] |
41,423,071 | https://en.wikipedia.org/wiki/Bolshoi%20cosmological%20simulation | The Bolshoi simulation, a computer model of the universe run in 2010 on the Pleiades supercomputer at the NASA Ames Research Center, was the most accurate cosmological simulation to that date of the evolution of the large-scale structure of the universe.
The Bolshoi simulation used the now-standard ΛCDM (Lambda-CDM) model of the universe and the WMAP five-year and seven-year cosmological parameters from NASA's Wilkinson Microwave Anisotropy Probe team. "The principal purpose of the Bolshoi simulation is to compute and model the evolution of dark matter halos, thereby rendering the invisible visible for astronomers to study, and to predict visible structure that astronomers can seek to observe." “Bolshoi” is a Russian word meaning “big.”
The first two of a series of research papers describing Bolshoi and its implications were published in 2011 in the Astrophysical Journal. The first data release of Bolshoi outputs has been made publicly available to the world's astronomers and astrophysicists. The data include output from the Bolshoi simulation and from the BigBolshoi, or MultiDark, simulation of a volume 64 times that of Bolshoi. The Bolshoi-Planck simulation, with the same resolution as Bolshoi, was run in 2013 on the Pleiades supercomputer using the Planck satellite team's cosmological parameters released in March 2013. The Bolshoi-Planck simulation is currently being analyzed in preparation for publication and distribution of its results in 2014.
Bolshoi simulations continue to be developed as of 2018.
Contributors
Joel R. Primack's team at the University of California, Santa Cruz, partnered with Anatoly Klypin's group at New Mexico State University, in Las Cruces to run and analyze the Bolshoi simulations. Further analysis and comparison with observations by Risa Wechsler's group at Stanford University and others are reflected in the papers based on the Bolshoi simulations.
Rationale
A successful large-scale simulation of the evolution of galaxies, with results consistent with what is actually seen by astronomers in the night sky, provides evidence that the theoretical underpinnings of the models employed, i.e., the supercomputer implementations ΛCDM, are sound bases for understanding galactic dynamics and the history of the universe, and opens avenues to further research. The Bolshoi Simulation isn't the first large-scale simulation of the universe, but it is the first to rival the extraordinary precision of modern astrophysical observations.
The previous largest and most successful simulation of galactic evolution was the Millennium Simulation Project, led by Volker Springel. Although the success of that project stimulated more than 400 research papers, the Millennium simulations used early WMAP cosmological parameters that have since become obsolete. As a result, they led to some predictions, for example about the distribution of galaxies, that do not match very well with observations. The Bolshoi simulations use the latest cosmological parameters, are higher in resolution, and have been analyzed in greater detail.
Methods
The Bolshoi simulation follows the evolving distribution of a statistical ensemble of 8.6 billion particles of dark matter, each of which represents about 100 million solar masses, in a cube of 3-dimensional space about 1 billion light years on edge. Dark matter and dark energy dominate the evolution of the cosmos in this model. The dynamics are modeled with the ΛCDM theory and Albert Einstein's general theory of relativity, with the model including cold dark matter (CDM) and the Λ cosmological constant term simulating the cosmic acceleration referred to as dark energy.
The first 100 million years (Myr) or so of the evolution of the universe after the Big Bang can be derived analytically. The Bolshoi simulation was started at redshift z=80, corresponding to about 20 Myr after the Big Bang. Initial parameters were calculated with linear theory as implemented by the CAMB tools, part of the WMAP website. The tools provide the initial conditions, including a statistical distribution of positions and velocities of the particles in the ensemble, for the much more demanding Bolshoi simulation of the next approximately 13.8 billion years. The experimental volume thus represents a random region of the universe, so comparisons with observations must be statistical.
The Bolshoi simulation employs a version of an adaptive mesh refinement (AMR) algorithm called an adaptive refinement tree (ART), in which a cube in space with more than a predefined density of matter is recursively divided into a mesh of smaller cubes. The subdivision continues to a limiting level, chosen to avoid using too much supercomputer time. Neighboring cubes are not permitted to vary by too many levels, in the case of Bolshoi by more than one level of subdivision, to avoid large discontinuities. The AMR/ART method is well suited to model the increasingly inhomogeneous distribution of matter that evolves as the simulation proceeds. “Once constructed, the mesh, rather than being destroyed at each time step, is promptly adjusted to the evolving particle distribution.” As the Bolshoi simulation ran, the position and velocity of each of the 8.6 billion particles representing dark matter was recorded in 180 snapshots roughly evenly spaced over the simulated 13.8-billion-year run on the Pleiades supercomputer. Each snapshot was then analyzed to find all the dark matter halos and the properties of each (particle membership, location, density distribution, rotation, shape, etc.). All this data was then used to determine the entire growth and merging history of every halo. These results are used in turn to predict where galaxies will form and how they will evolve. How well these predictions correspond to observations provides a measure of the success of the simulation. Other checks were also made.
Results
The Bolshoi simulation is considered to have produced the best approximation to reality so far obtained for so large a volume of space, about 1 billion light years across. “Bolshoi produces a model universe that bears a striking and uncanny resemblance to the real thing. Starting with initial conditions based on the known distribution of matter shortly after the Big Bang, and using Einstein’s general theory of relativity as the ‘rules’ of the simulation, Bolshoi predicts a modern-day universe with galaxies lining up into hundred-million-light-year-long filaments that surround immense voids, forming a cosmic foam-like structure that precisely matches the cosmic web as revealed by deep galaxy studies such as the Sloan Digital Sky Survey. To achieve such a close match, Bolshoi is clearly giving cosmologists a fairly accurate picture of how the universe actually evolved.” The Bolshoi simulation found that the Sheth–Tormen approximation overpredicts the abundance of halos by a factor of for redshifts .
Support
This research was supported by grants from NASA and the National Science Foundation (U.S.) to Joel Primack and Anatoly Klypin, including massive grants of supercomputer time on the NASA Advanced Supercomputing (NAS) supercomputer Pleiades at NASA Ames Research Center. Hosting of the Bolshoi outputs and analyses at Leibniz Institute for Astrophysics Potsdam (AIP) is partially supported by the MultiDark grant from the Spanish MICINN Programme.
In popular culture
A visualization from the Bolshoi simulation was narrated in the National Geographic TV special Inside the Milky Way. The Icelandic singer-songwriter Björk used footage from the Bolshoi cosmological simulation in the performance of her musical number “Dark Matter” in her Biophilia concert.
References
References for figure
Mantz, A., Allen, S. W., Ebeling, H., & Rapetti, D. 2008, MNRAS, 387, 1179
Henry, J. P., Evrard, A. E., Hoekstra, H., Babul, A., & Mahdavi, A. 2009, ApJ,691, 1307
Vikhlinin, A., Kravtsov, A. V., Burenin, R. A., et al. 2009, ApJ, 692, 1060
Rozo, E., Rykoff, E. S., Evrard, A., et al. 2009, ApJ, 699, 768
External links
A. Klypin’s (NMSU) Bolshoi Cosmological Simulation Website
Bolshoi Movies
Physical cosmology
Cosmological simulation | Bolshoi cosmological simulation | [
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41,425,848 | https://en.wikipedia.org/wiki/NGC%201052 | NGC 1052 is an elliptical galaxy in the constellation Cetus. It was discovered on January 10, 1785 by the astronomer William Herschel. It is a member of the eponymous NGC 1052 Group.
Features
NGC 1052 is located at a distance of around 63 million light years from the Milky Way, and has a LINER-type active galactic nucleus which signals the intense starburst activity in the galaxy's center that were confirmed with observations with better resolution showing a number of star-forming regions and young star clusters.
NGC 1052 shows also two small jets emerging from its nucleus as well as a very extended disc of neutral hydrogen, far larger than the galaxy itself. Additionally, the stars and the ionized gas rotate along different axes. All these features suggesting a gas-rich galaxy collided and merged with it 1 billion years ago producing all the above features.
The shape of NGC 1052 is thought to be a triaxial ellipsoid. The longest axis of the ellipsoid is probably aligned at a position angle of −41°, which is the axis around which the ionized gas would be rotating.
A scale image of NGC 1052 and its satellite galaxies is available at the reference.
Central black hole
NGC 1052 hosts a rapidly rotating supermassive black hole with a mass of 154 million with a large magnetic field of 2.6 Tesla, which, according to astronomer Anne-Kathrin Baczko, the leader of the team that made this discovery, provides enough magnetic energy to power the previously mentioned twin relativistic jets.
This black hole is a promising target for imaging by the Event Horizon Telescope. The location of the black hole in NGC 1052 was by 2016 the most precisely known in the universe, with the exception of Sagittarius A*, the supermassive black hole found at the heart of our own galaxy.
See also
NGC 1052-DF2, a galaxy assumed to be associated with NGC 1052, and which appears to have little or no dark matter
NGC 1052-DF4, another galaxy assumed to be associated with NGC 1052, and which appears to have little or no dark matter
References
External links
Elliptical galaxies
1052
Cetus
LINER galaxies
010175 | NGC 1052 | [
"Astronomy"
] | 453 | [
"Cetus",
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] |
41,426,709 | https://en.wikipedia.org/wiki/Nafees%20Bin%20Zafar | Nafees Bin Zafar (born 1978) is a visual effects and computer graphics software engineer of Bangladeshi origin based in Los Angeles, United States. He is currently Principal Engineer at animation studio DreamWorks Animation. In 2008, he received an Academy Scientific and Technical Award in Scientific and Engineering Award (Academy Plaque) category for the development of the fluid simulation system at Digital Domain. , becoming the first person of Bangladeshi origin to win an Academy Award in any category. He also received an Academy Scientific and Technical Award in Technical Achievement Award (Academy Certificate) category in 2015 for the separate development of two large-scale destruction simulation systems based on Bullet.
Early life
Zafar was born in Dhaka, Bangladesh, and moved to Charleston, South Carolina with his family when he was 11. He studied at Dhaka Residential Model College till grade 6. He attended College of Charleston and graduated in software engineering. During that time, he studied 3D graphics using SGI computers at Virtual Reality South.
He is the son of Zafar Bin Bashar, a partner at Marcum & Kliegman, and Nafeesa Zafar, who resides in Long Island, New York. He is a great-grandson of the famous late Bangladeshi poet Golam Mostofa and grand-nephew of the famous Bangladeshi artist and puppeteer Mustafa Monwar.
Career
In February 2008, Zafar received an Academy Scientific and Technical Award for the development of the fluid simulation system at Digital Domain, which was used in the film Pirates of the Caribbean: At World's End.
He received the Scientific and Engineering Award along with his colleagues at Digital Domain, thus becoming the first person of Bangladeshi origin to win an Academy Award.
In February 2015, Zafar was again recognized by the Academy when he and his colleagues at Digital Domain received a Technical Achievement Award for their work on the Drop Destruction Toolkit, used to create visual effects in the film 2012. He is now Principal Engineer at DreamWorks Animation.
Filmography
Madagascar 3: Europe's Most Wanted (principal engineer)
Puss in Boots (senior software engineer)
Kung Fu Panda 2 (senior software engineer)
Megamind (senior production engineer)
Shrek Forever After (senior production engineer)
Percy Jackson & the Lightning Thief (software engineer)
The Seeker: The Dark Is Rising (visual effects: Digital Domain)
Pirates of the Caribbean: At World's End (technical developer)
Flags of Our Fathers (technical developer)
Stealth (software engineer)
The Croods (research and development principal engineer: DreamWorks Animation)
See also
DreamWorks Animation
References
External links
Nafees Bin Zafar: Linkedin profile
1978 births
Living people
Academy Award for Technical Achievement winners
College of Charleston alumni
Software engineers
People from Dhaka | Nafees Bin Zafar | [
"Engineering"
] | 543 | [
"Software engineering",
"Software engineers"
] |
41,427,670 | https://en.wikipedia.org/wiki/Strudel%20%28ice%29 | A strudel (plural: strudel) is a vertical hole in sea ice through which downward jet-like, buoyancy-driven drainage of flood water is thought to occur. This feature is less than a few tens of meters in size and typically occurs within 30 km from a river mouth, in the sea ice expanse that is fastened to the coastline (known as fast ice). Once the water that flooded the ice has completely drained off the ice surface, strudel become recognizable by a radial pattern of feeder channels that lead to the hole. They are elongated and irregularly spaced, with the larger ones up to several kilometers apart. Their distribution tends to be controlled by weak areas in the ice – in places, they line up along fractures or refrozen extensional cracks. The ice sheet where they occur may be 2 m in thickness, at water depths (below the ice) in the order of a few meters.
The term strudel is German, and designates a whirlpool, in reference to the water vortex that forms above these features during drainage. It has been suggested that this vortex could present a hazard for investigators wishing to study this phenomenon in the field, and that this would explain, at least partly, why little is known about strudel.
Formation
The formation of strudel is related to the break up of a frozen river during the melting season, where this river runs into a sea ice expanse. At that time, fresh water flows onto the fast ice with a progression rate of about 2–3 m/s, extending up to a few tens of kilometers away from the river mouth. Water depths above the ice surface may be up to a few meters. A strudel forms as a result of water carving its way through the ice sheet. Drainage is initiated through small openings or cracks in the ice resulting from the weight of the freshwater. Some are reportedly enlarged seal-breathing holes. Within a few days, the water drains off the ice. Drainage is driven by the buoyancy of the ice, not by the density difference between freshwater and sea water. The pressure difference responsible for that flow is a function of the ice thickness and the difference in unit weight between the ice and the water.
Strudel scours
Water gushing downward through strudel produces scour depressions in the seabed. This occurs at shallow water levels, within the two-meter bathymetry contour, and up to 8 meters. The depth of these depressions may reach 6 meters or more. This depends on a number of factors: seabed properties, water depth, flow velocity, flow duration and size and shape of the orifice. The width of individual strudel scours are generally in the order of 10–20 meters. An excavation rate of 2.5 km−2y−1 has been reported, as well as complete back filling by sediments within 2–3 years. Such rapid filling rates imply that most strudel scours are recent events. Strudel scours present risks to submarine pipelines if water action removes the soil from below a pipe segment such that it becomes a free span. The consequences include: vortex-induced oscillation, lateral buckling and overstress due to self-weight. Moreover, the presence of a pipeline may conceivably promote the generation of strudel because of the heat generated by this structure, which may thin and thus weaken the ice above it.
A distinction is made between strudel scours and ice scours. The former is the result of water action, as is the case for other types of scours (bridge and tidal scours); the latter, also called gouges, are produced by drifting ice and are most often linear features.
See also
Bridge scour
Fast ice
Seabed gouging by ice
Sea ice
Submarine pipeline
Tidal scour
References
Sea ice
Oceanography | Strudel (ice) | [
"Physics",
"Environmental_science"
] | 792 | [
"Physical phenomena",
"Earth phenomena",
"Applied and interdisciplinary physics",
"Sea ice",
"Hydrology",
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65,720,315 | https://en.wikipedia.org/wiki/Death%20regulator%20Nedd2-like%20caspase | Death regulator Nedd2-like caspase (Nc, Nedd2-like caspase or Dronc) was firstly identified and characterised in Drosophila in 1999 as a cysteine protease containing an amino-terminal caspase recruitment domain. At first, it was thought of as an effector caspase involved in apoptosis, but subsequent findings have proved that it is, in fact, an initiator caspase with a crucial role in said type of programmed cell death.
Structure
Caspase Dronc is a Drosophila melanogaster protein codified by the Dronc gene. It belongs to the cysteine-aspartic proteases family, as it is a protease enzyme that takes part in programmed cell death processes. It is composed of beta-sheet structures surrounded by alpha-helices, which is a common feature in the protein family. Caspases are formed by ensembled or single active heterodimers that come from the intra-chain proteolytic cleavage of inactive zymogens. This cleavage is coordinated by a specific initiator caspase (which undergoes adaptor-assisted self-activation) for each effector caspase. A common feature among initiator caspases is the presence of a long amino-terminal domain with intermolecular interaction motifs such as the caspase recruiting domain (CARD).
Five caspases have been identified in Drosophila. Two of these present long prodomains (structural domains of the caspases) and are considered to be initiator caspases (Dronc and DCP-2 / DREDD). The other three (DCP-1, DrICE and DECAY), which have short prodomains, act as effector caspases activated by initiator caspases. The uncleaved Dronc zymogen is only presented as a monomer, while the autocleaved protein forms a homodimer. It is presumed that its autocatalytic cleavage activates the protein by generating a dimerisation in which both monomers stabilise their active sites mutually. Caspase Dronc's active site is located between positions 271 and 318 of the protein sequence.
Genetics
The Dronc gene is located in the 3L chromosome of the fly, between the 9,968,479 bp and the 9,971,002 bp. It transcripts one single polypeptide and there are 66 reported alleles of the gene. Two mutations have been found in the positions 150 and 184, respectively. The Dronc protein has a length of 450 amino acids and a mass of 51,141 Da.
Human orthologs
Although most human caspases are considered orthologs of caspase Dronc, the one that resembles it the most is Caspase-2. However, Nedd2-like caspase is the functional homolog of mammalian Caspase-9.
Location
Due to its function and its mostly hydrophilic character, Dronc can be located in the apoptosome, the plasma membrane and the nucleus of the cell. Cells containing this protein have been found in the following structures of the Drosophila melanogaster: extended germ band embryo; eye disc; foregut primordium; germline cyst; and gut section.
Activation
The activation of caspases is a fundamental step required to execute apoptosis. Initiator caspases, such as Dronc, which is the only initiator caspase in Drosophila melanogaster, are activated through different mechanisms, the main one being autocleavage. Understanding how caspases are activated is a crucial element in order to come up with therapeutic treatments triggering specific caspases. For instance, it has been shown that mice missing or having inactivated caspase-9 present several neurological impairments and have a faulty response to cell damage. Just as caspase 9 in mammals, caspase Dronc is a protein that has a caspase activation and recruitment domain (CARD). It is the only Drosophila caspase presenting this domain: this can represent the possibility of establishing a valuable comparison between their activation or inhibition mechanisms.
Activation
Autocleavage
To activate zymogen at first, caspase Dronc autocleaves at residue E352 (Glu352, a glutamic acid residue). Autocleavage at this residue induces dimerization and stabilization of the active site. Autocleavage at E352 results in Pr1, which weighs 40kDa. One study showed that, in Drosophila melanogaster S2 cells, Dronc autocleavage is essential for the zymogen activation. Even though caspase Dronc goes through other processes which will be discussed later, Dronc autocleavage was found to be absolutely necessary to induce apoptosis, whereas other cell cofactors seemed to not be enough to induce activation of Dronc if it had not previously been autocleaved at residue E352. After autocleavage, catalytic activity of Dronc is drastically higher than that of the zymogen. However, these results seem to be contradictory with those of another study conducted in BG2 cells. This study concluded that autocleavage at residue E352, just as autocleavage at other sites such as E143, is not needed for Dronc to activate and, consequently, to induce apoptosis.
Processing by DrICE
Dronc can also be cleaved by the effector caspase DrICE, which is activated by caspase Dronc itself after autocleavage. However, it has also been suggested that caspases other than Dronc could activate DrICE. Even though uncleavable mutations of Dronc may have the ability to process caspase DrICE, it is autocleaved Dronc that processes caspase DrICE in Drosophila melanogaster cells. Cleavage of Dronc by DrICE occurs at residue D135 (Asp135, an aspartic acid residue). At the beginning of apoptosis, full-length Dronc and autocleaved Dronc, Pr1, are present and can be used as a substrate for DrICE processing. Cleavage at residue D135 can therefore result in two products: cleavage of Dronc Pr1 results in fully processed Dronc, whereas cleavage of full Dronc results in Pr2, which weights 36kDa. However, since Dronc Pr1 seems to be the most abundant during early stages of apoptosis, most caspase Dronc ends up being fully processed.
Interaction with apoptosome
In humans, initiator caspases such as Caspase-2 and Caspase-9 have a prodomain that cleaves caspases to a holoenzyme complex in order to activate the protein. These caspases have a caspase recruitment domain (CARD) that allows them to interact with Apaf-1. The Drosophila melanogaster Apaf-1 homolog, Dark, forms an oligomer with eight Dark chains when dATP is present. This complex is called the apoptosome. Dark, just as Apaf-1, has an N-terminal CARD domain that interacts with caspase Dronc, which is incorporated into this protein complex that will induce cell death.
Recruitment of Dronc by Dark seems to facilitate Dronc autocleavage at residue E352. Dark might not be enough on its own to activate caspase Dronc; it has been suggested that other factors could increase the activation of Dronc (and DrICE) through interaction with the apoptosome. However, in Drosophila melanogaster cells, Dark activity is necessary for normal execution of apoptosis.
Inhibition
Ubiquitylation
Activation of Dronc is also monitored by ubiquitylation. (see figure 2) Ubiquitylation is a modification that happens after protein translation: in this process, protein ubiquitin conjugates to a lysine residue. However, the exact mechanism of Dronc ubiquitylation remains partially unknown to this day. In Drosophila melanogaster cells, mono-ubiquitylation on residue K78 (located in the CARD domain) is carried in caspase Dronc. Ubiquitylation of this residue of the CARD domain, which interacts with the apoptosome during apoptosis, keeps Dronc from activating in the apoptosome and prevents apoptosis of the cell. Ubiquitylation by E3 ubiquitin ligase activity of Diap-1 negatively regulates Dronc activity. Even a partial decrease in ubiquitylation is already enough to importantly rise Dronc activity. Moreover, it has also been shown that K78 mono-ubiquitylation assumes an inhibitory role in Dronc's non-apoptotic capacities, which may not need its catalytic movement, but still being significant for the endurance of the fruit fly. In Drosophila melanogaster cells, caspase Dronc is ubiquitylated by Diap-1. Similarly, effector caspases Caspase-3 and Caspase-7 are monoubiquitylated by cIAP2 in vitro.
Diap-1
Inhibitor of Apoptosis Proteins (IAPs) are a family of proteins that act as endogenous inhibitors of apoptosis: they inhibit caspases. Diap-1 is the Drosophila melanogaster IAP that interacts with both Dronc and DrICE through IAP domains. Some studies have found that Diap-1 inhibits and degrades caspase Dronc, and impairment of Diap-1 interaction with Dronc would prevent the caspase from degrading.
Diap-1 regulates caspase activity in Drosophila melanogaster, thus making Dronc activation dependent on removing Diap-1. Diap-1 is the protein that inhibits both Dronc and DrICE, and prevents apoptosis from being executed. Removal of Diap-1 RNAi triggers caspase activation and, thus, apoptosis. Moreover, during apoptosis, removal of Diap-1 facilitates interaction between Dronc and Dark, which supports the fact that Diap-1 is charged of regulating and inhibiting caspase Dronc. In fact, during apoptosis, proteosomal degradation of Diap-1 takes place (and is necessary) right before cleavage and activation of caspases Dronc and DrICE. Finally, binding of Diap-1 seems to not be sufficient for Dronc inhibition; it seems that ubiquitylation the RING domain of Diap-1 is necessary for complete inhibition of Dronc.
Functions
Caspase Dronc has an essential catalytic activity. It is defined as a cysteine protease (or thiol protease), which means that a nucleophilic cysteine thiol forms a catalytic triad (Cys–His–Asn) at the active site of the enzyme that intercedes in the catalysis. The main function of this kind of endopeptidases is to catalyze the hydrolysis of peptide bonds in order to cleave proteins into smaller fragments (see figure 3). For that reason, Nedd2-like caspase is responsible for the activation of effector caspases. On the other hand, as a caspase, Dronc is fully involved in programmed cell death (PCD) processes, which have repercussions in regulative and reproductive functions of the Drosophila melanogaster.
Apoptotic functions
Apoptosis is an essential process for the development of multicellular organisms. Its role is to remove excess cells during development (e.g. sculpting the digits of vertebrates), as well as being responsible for detaching damaged, potentially dangerous, cells. Because of its extreme importance, this pathway has been shown to be vastly conserved throughout evolution. One event that is capable of triggering this type of programmed cell death is the activation of the JNK (c-Jun N-terminal kinase) signalling pathway, due to stress caused by chromosomal instability (CIN). The apoptosis pathway is regulated by caspases, a family of proteases that lead to the disassembling of the cell by cleaving protein targets following an aspartate residue. In response to certain apoptotic stimuli, the inactive caspases zymogens turn into active enzymes that start a cascade of caspases-induced proteolytic cleavage processes which culminate with the DNA decomposition and the cell death. Next, neighbouring cells or macrophages (often called apoptotic bodies) engulf whatever is left of the dwindled cell in order to minimize its effect on the surrounding ones, and at the same time to avoid inducing an immune response in the body. Studies link failure of apoptosis activation with the development of some types of cancer.
Specifically, in the context of the apoptotic signalling cascade, Dronc's role as an initiator caspase consists in the activation of effector caspases such as DrICE or Dcp-1. Nonetheless, Dronc has been found to be a surprisingly efficient catalyst, with a kinetic performance one hundred and eightyfold lesser than that of caspase-9. Hence, akin to caspase 9's behaviour, an adequate enzymatic activity might demand the formation of a holoenzyme complex involving close associations with Dark, Apaf-1's Drosophila ortholog.
Comparison of the main apoptotic machinery
The diagram (figure 4) shows functional homologues of apoptotic proteins (colour-coded correspondence) in Drosophila melanogaster and mammals.
A) Drosophila: In individuals of the Drosophila genus numerous signalling pathways in charge of regulating anti-IAPs Reaper, Hid, and Grim (RHG), Dark scaffold proteins, and Dronc initiator caspases. On the one hand, RHG expression causes the degradation of Diap-1, Inhibitors of apoptosis proteins (IAPs) and the release of Dronc initiator caspases. On the other hand, it allows it to associate with Dark scaffold proteins to form a functional apoptosome and activate the DrICE and Dcp-1 effector caspases. Both pathways are necessary to properly activate caspases and are coordinately regulated. Of note is the existence of the protein from a p35 baculovirus, which has the ability to suppress them, thus blocking the pathway.
B) Mammals: Among members of the class Mammalia, the balance between members of the pro- and anti-apoptotic Bcl-2 family is a key factor in the commitment to apoptosis by regulating the release of cytochrome and IAP antagonists of mitochondria. The binding of cyt c to Apaf-1 promotes apoptosome assembly, which in turn groups and activates caspase-9s. In the end, anti-IAPs release the IAPs proteins (mainly XIAPs).
Development (Metamorphosis)
Apoptosis can be triggered by extrinsic or intrinsic signals. Both of them occur in Drosophila during its development. For example, a higher concentration of ecdysones (common during the metamorphosis) leads cuticle deposition and larval moults, as well as puparium formation and histolysis of larval midgut. This hormone causes head evasion as well as cell death of larval salivary gland. It is thought that ecdysone induced apoptosis is regulated by the Caspase Dronc. This protein conducts Rpc- and Grim-induced apoptosis, but not Hid-. Regarding other developmental processes, apoptosis conducts the ratio of stem cell-like neuroblasts in the central nervous system.
Additionally, research shows that through the employment the iRNA (RNA interference) mechanism, budding Drosophila embryos have displayed a striking reduction of cell death processes, thus demonstrating that Dronc is important for programmed cell death during embryogenesis. The outcome of said experiments results lead to believe that D. melanogaster's initiator caspase plays an essential role in mediating PCD.
Accidental Cell Death and Compensatory Proliferation
Cell death during animal tissues development is rapidly compensated by cell divisions in a process called compensatory proliferation. The developing Drosophila imaginal disk has a very high regenerative capacity that is independent of the size control mechanism that governs the disk. It is not completely known how these phenomena are regulated, but it is thought that dying cells secrete mitogens that activate the reproduction of neighbouring cells, a process that would be regulated by apoptotic signalling pathway (in which Caspase Dronc is involved). This means that if cells were stimulated to undergo apoptosis, and at the same time artificially kept alive (e.g. by overexpressing the inhibitor of effector caspases, p35), neighbouring cells would be led to conduct uncontrollable compensatory proliferation. The fact that Dronc is insensitive to p35 inhibition has suggested that it could be required for compensatory proliferation, a hypothesis that was demonstrated in 2006.
Non-apoptotic functions
Promoting DNA damage signalling
In addition to its role in apoptosis and compensatory proliferation, Caspase Dronc promotes DNA damage signalling by facilitating γH2Av activity, a variation of histone H2Ax whose phosphorylation marks DNA damage and repairs it by recruiting DNA repair machinery. Thus, Dronc would be involved in both DDR and apoptosis depending on its availability and the needs of the organism.
Involvement in genetic pathologies
Cancer
Tissue homeostasis can be defined as the maintenance of a balance between cell division and PCD, resulting in the tissue in question maintaining a relatively constant number of cells. In case it gets disturbed, two things could happen. The first would be for the cells to die faster than they can divide, which would result in tissue atrophy. Alternatively, if programmed cell death were blocked in some of the cells, they would not die enough and would end up triggering carcinogenesis in the tissue. For this reason, apoptosis evasion has been identified as a key hallmark of cancer.
As previously mentioned, caspases have a decisive implication in the initiation and execution of apoptosis. Therefore, it is reasonable to think that at low levels they can cause decreased apoptosis and carcinogenesis. Somatic mutations in caspase-3 were detected at fairly low frequencies in certain human cancers, like colon and stomach cancer and non-Hodgkin's lymphoma (NHL). Furthermore, decreased caspase 9 (a human Dronc ortholog) expression has also been linked to 46% of colon cancers.
Alzheimer's disease
Caspase-2 could have an implication in neurodegenerative disorders such as Alzheimer's disease. Latest evidence has shown that Tau's Caspase-2 cleavage results in the decline of Alzheimer's memory function. Notably, Dronc-dependent Tau cleavage was also shown in an experiment that connected circadian rhythm and Alzheimer's disease. To boot, it was also discovered that Tau expression mediated by the initiator caspase in question could induce a rough eye phenotype due to degeneration of photoreceptor neurons of Drosophila melanogaster.
Oxidative stress and ageing
An experiment questioning the impact of apoptosis on ageing found that caspase-2-deficient mice displayed shortened life-span and elevated characteristics associated with ageing. Further research has established that caspase-2 plays a role in oxidative stress response, mitochondrial function regulation and metabolic pathways, which may be potential mechanisms through which said caspase regulates ageing. Concurrently, Dronc null mutant flies, also perished within a few days after hatching. In addition, another review has shown that aging flies have raised activated Dronc levels.
References
Further reading
Programmed cell death
Caspases | Death regulator Nedd2-like caspase | [
"Chemistry",
"Biology"
] | 4,356 | [
"Senescence",
"Programmed cell death",
"Signal transduction"
] |
65,721,728 | https://en.wikipedia.org/wiki/Rezvilutamide | Rezvilutamide (), sold under the brand name Ariane, is a nonsteroidal antiandrogen which is approved for the treatment of prostate cancer in China and is or was under development for the treatment of breast cancer. It is a selective androgen receptor antagonist with reduced brain distribution compared to the structurally related nonsteroidal antiandrogen enzalutamide. The drug was developed by Jiangsu Hengrui Medicine. Other structural analogues of rezvilutamide that are also used as antiandrogens besides enzalutamide include apalutamide and proxalutamide.
References
Benzonitriles
Diols
Hormonal antineoplastic drugs
Ketones
Imidazolidines
Nonsteroidal antiandrogens
Sulfur compounds
Trifluoromethyl compounds
Drugs developed by Jiangsu Hengrui | Rezvilutamide | [
"Chemistry"
] | 173 | [
"Ketones",
"Functional groups"
] |
65,722,968 | https://en.wikipedia.org/wiki/HAT-P-29 | HAT-P-29, also known as Muspelheim since 2019 (as part of the IAU's NameExoWorlds project), is a star about away. It is a G-type main-sequence star. The star's age of 2.2 billion years is less than half that of the Sun. HAT-P-29 is slightly enriched in heavy elements, having 35% more iron than the Sun.
A very faint 19th-magnitude stellar companion was detected in 2016 at a projected separation of 3.290″, but Gaia DR2 astrometry suggests that this is an unrelated background object.
Planetary system
In 2011 a transiting hot Jupiter planet, HAT-P-29b, was detected on a mildly eccentric orbit. The planet was named "Surt" by Denmark in 2019. The planetary orbit is likely aligned with the equatorial plane of the star, with a misalignment equal to 26 degrees.
In 2018, a transit-timing variation survey indicated additional planets with masses exceeding approximately half of Earth are absent in the system.
References
Perseus (constellation)
G-type main-sequence stars
Binary stars
Planetary systems with one confirmed planet
Planetary transit variables
J02123147+5146435 | HAT-P-29 | [
"Astronomy"
] | 256 | [
"Perseus (constellation)",
"Constellations"
] |
65,725,600 | https://en.wikipedia.org/wiki/Travoprost/timolol | Travoprost/timolol, sold under the brand name Duotrav among others, is a fixed-dose combination medication used for the treatment of glaucoma. It contains travoprost and timolol maleate.
It was approved for medical use in the European Union in April 2006.
References
External links
Combination drugs
Ophthalmology drugs | Travoprost/timolol | [
"Chemistry"
] | 78 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
65,727,526 | https://en.wikipedia.org/wiki/List%20of%20long%20species%20names | Living organisms are known by scientific names. These binomial names can vary greatly in length, and some of them can become very long depending on the meanings they try to convey. This list of longest species names lists the longest scientific binomials.
Species in this list are grouped by length of their name. Only binomials are considered, not subgenera, trinomial names of subspecies or infraspecific names. Family is given for each species (or the closest taxonomic rank if family is unassigned), with a short explanation. The shortest scientific species names can be found in the List of short species names.
73 letters
50 letters
44 letters
42 letters
40 letters
39 letters
38 letters
37 letters
36 letters
35 letters
References
Taxonomic lists | List of long species names | [
"Biology"
] | 155 | [
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists"
] |
65,728,131 | https://en.wikipedia.org/wiki/Transition%20metal%20carboxylate%20complex | Transition metal carboxylate complexes are coordination complexes with carboxylate (RCO2−) ligands. Reflecting the diversity of carboxylic acids, the inventory of metal carboxylates is large. Many are useful commercially, and many have attracted intense scholarly scrutiny. Carboxylates exhibit a variety of coordination modes, most common are κ1- (O-monodentate), κ2 (O,O-bidentate), and bridging.
Acetate and related monocarboxylates
Structure and bonding
Carboxylates bind to single metals by one or both oxygen atoms, the respective notation being κ1- and κ2-. In terms of electron counting, κ1-carboxylates are "X"-type ligands, i.e., a pseudohalide-like. κ2-carboxylates are "L-X ligands", i.e. resembling the combination of a Lewis base (L) and a pseudohalide (X). Carboxylates are classified as hard ligands, in HSAB theory.
For simple carboxylates, the acetate complexes are illustrative. Most transition metal acetates are mixed ligand complexes. One common example is hydrated nickel acetate, Ni(O2CCH3)2(H2O)4, which features intramolecular hydrogen-bonding between the uncoordinated oxygens and the protons of aquo ligands. Stoichiometrically simple complexes are often multimetallic. One family are the basic metal acetates, of the stoichiometry [M3O(OAc)6(H2O)3]n+.
Homoleptic complexes
Homoleptic carboxylate complexes are usually coordination polymers. But exceptions exist.
A molecular monocarboxylate is silver acetate, Ag2(OAc)2.
Molecular diacetates are more common. Several diacetates adopt the Chinese lantern structure. Well studied examples include the dimetal tetraacetates (M2(OAc)4) including rhodium(II) acetate, copper(II) acetate, molybdenum(II) acetate, and chromium(II) acetate. Platinum diacetate and palladium diacetate feature Pt4 and Pd3 cores, further illustrating the tendency of acetate ligands to stabilize multimetallic structures.
Mononuclear tricarboxylates include derivatives of 1-adamantanecarboxylic acid, which have the formula [M(O2CC10H11)3]− (M = Co, Ni, Zn). The carboxylates are bidentate.
Synthesis
Many methods allow the synthesis of metal carboxylates. From preformed carboxylic acid, the following routes have been demonstrated:
acid-base reactions:
protonolysis:
oxidative addition:
From preformed carboxylate, salt metathesis reactions are common:
Metal carboxylates can be prepared by carbonation of highly basis metal alkyls:
Reactions
A common reaction of metal carboxylates is their displacement by more basic ligands. Acetate is a common leaving group. They are especially prone to protonolysis, which is widely used to introduce ligands, displacing the carboxylic acid. In this way octachlorodimolybdate is produced from dimolybdenum tetraacetate:
Acetates of electrophilic metals are proposed to function as bases in concerted metalation deprotonation reactions.
Attempts to prepare some carboxylate complexes, especially for electrophilic metals, often gives oxo derivatives. Examples include the oxo-acetates of Fe(III), Mn(III), and Cr(III). Pyrolysis of metal carboxylates affords acid anhydrides and the metal oxide. This reaction explains the formation of basic zinc acetate from anhydrous zinc diacetate.
In some cases, monodentate carboxylates undergo O-alkylation to give esters. Strong alkylating agents are required.
Other carboxylates
Many carboxylates form complexes with transition metals. Alkyl and simple aryl carboxylates behave similarly to the acetates. Trifluoroacetates differ in mononuclear complexes because it is usually monodentate, e.g. [Zn(κ2-O2CCH3)2(OH2)2] vs [Zn(κ1-O2CCF3)2(OH4)2].
Applications
Metal naphthenates and ethylhexanoates
Naphthenic acids, mixtures of long chain and cyclic carboxylic acids extracted from petroleum, form lipophilic complexes (often called salts) with transition metals. These metal naphthenates, have the formula M(naphthenate)2, or M3O(naphthenate)6, have diverse applications including synthetic detergents, lubricants, corrosion inhibitors, fuel and lubricating oil additives, wood preservatives, insecticides, fungicides, acaricides, wetting agents, thickening agent, and oil drying agents. Industrially useful naphthenates include those of aluminium, magnesium, calcium, barium, cobalt, copper, lead, manganese, nickel, vanadium, and zinc.< Illustrative is the use of cobalt naphthenate for the oxidation of tetrahydronaphthalene to the hydroperoxide.
Like naphthenic acid, 2-ethylhexanoic acid forms lipophilic complexes that are used in organic and industrial chemical synthesis. They function as catalysts in polymerizations as well as for oxidation reactions as oil drying agents.
Metal ethylhexanoates are referred to as metallic soaps.
Aminopolycarboxylates
A commercially important family of metal carboxylates are derived from aminopolycarboxylates, e.g., EDTA4-. Related to these synthetic chelating agents are the amino acids, which form large families of amino acid complexes. Two amino acids, glutamate and aspartate, have carboxylate side chains, which function as ligands for iron in nonheme iron proteins, such as hemerythrin.
Metal organic frameworks (MOFs)
Metal organic frameworks, porous, three-dimensional coordination polymers, are often derived from metal carboxylate clusters. These clusters, called secondary bonding units (SBU's), are often linked by the conjugate bases of benzenedi- and tri- carboxylic acids.
Reagents for organic synthesis
It has been claimed that "cobalt carboxylates are the most widely used homogeneous catalysts in industry" as they are used in the oxidation of p-xylene to terephthalic acid.
Palladium(II) acetate has been described as being "among the most extensively used transition metal complexes in metal-mediated organic synthesis". Many coupling reactions utilize this reagent, which is soluble in organic solvents and which contains a built-in Bronsted base (acetate).
Dirhodium tetrakis(trifluoroacetate) is widely used catalyst for reactions involving diazo compounds.
Related topics
transition metal oxalate complex
References
Ligands
Coordination chemistry
Salts of carboxylic acids | Transition metal carboxylate complex | [
"Chemistry"
] | 1,580 | [
"Salts of carboxylic acids",
"Ligands",
"Coordination chemistry",
"Salts"
] |
65,728,206 | https://en.wikipedia.org/wiki/Olivetolic%20acid | Olivetolic acid is an organic compound with the formula . Several isomers with this formula exist. Olivetolic acid can be viewed as a derivative of olivetol ( 1,3,5-, with a carboxylic acid group adjacent to the pentyl (C5H11) group. Olivetolic acid has attracted attention because it is an intermediate in the biosynthetic pathway of the cannabinoids, found in Cannabis sativa.
The ester dimer of olivetolic acid, anziaic acid, is found in lichen.
References
Resorcinols
Alkyl-substituted benzenes
Dihydroxybenzoic acids
Pentyl compounds | Olivetolic acid | [
"Chemistry"
] | 144 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
65,730,500 | https://en.wikipedia.org/wiki/Anne%20Tihon | Anne Tihon (born 1944) is a Belgian historian of science specializing in the history of astronomy, with works on Theon of Alexandria, Byzantine astronomy, and astronomical tables. She is a professor emerita in the Faculty of Philosophy, Arts and Letters of the Université catholique de Louvain.
Books
Tihon's books and critical editions include:
Barlaam de Seminara, Traités sur les éclipses de soleil de 1333 et 1337 [ Barlaam of Seminara's treatises on the solar eclipses of 1333 and 1337], with Joseph Mogenet and Daniel Donnet, Éditions Peeters, 1977
Le petit commentaire de Théon d'Alexandrie aux tables faciles de Ptolémée [The Little Commentary of Theon of Alexandria on Ptolemy's Handy Tables], Studi e Testi Roma, 1978
Le "Grand Commentaire" de Theon d'Alexandrie aux tables faciles de Ptolemee, Vatican Library, Vol. I (with Joseph Mogenet), 1985; Vols. II–III, 1991; Vol. IV, 1999
Études d'astronomie byzantine [Studies in Byzantine astronomy], Ashgate, 1994
Georges Gémiste Pléthon, Manuel d'astronomie Gemistus Pletho, Manual of astronomy], with Raymond Mercier, Academia Bruylant, 1998
Une version Byzantine du traité sur l'astrolabe du Pseudo-Messahalla [A Byzantine version of the Pseudo-Messahalla astrolabe treatise], with Régine Leurquin and Claudy Scheuren, Bruylant, 2001
Πτολεμαιου προχειροι κανονες: Les Tables Faciles de Ptolémée [Ptolomy's Handy Tables], Vols. Ia–Ib, with Raymond Mercier, Université catholique de Louvain, 2011
Conformément aux observations d'Hipparque : le Papyrus Fouad inv. 267A [In accordance with Hipparchus's observations: the Papyrus Fouad inv. 267A], with Jean-Luc Fournet and Raymond Mercier, Université catholique de Louvain, 2014
Recognition
Tihon became a corresponding member of the International Academy of the History of Science in 1986, and was raised to a full member in 2002.
References
Living people
20th-century Belgian historians
Belgian women historians
Historians of astronomy
Academic staff of the Université catholique de Louvain
1944 births
21st-century Belgian historians | Anne Tihon | [
"Astronomy"
] | 541 | [
"People associated with astronomy",
"Historians of astronomy",
"History of astronomy"
] |
65,731,439 | https://en.wikipedia.org/wiki/HAT-P-28 | HAT-P-28 is the primary of a binary star system about 1320 light-years away. It is a G-type main-sequence star. The star's age is older than the Sun's at 6.1 billion years. HAT-P-28 is slightly enriched in heavy elements, having a 130% concentration of iron compared to the Sun. Since 2014, the binary star system is suspected to be surrounded by a debris disk with a 6.1″(2500 AU) radius.
The red dwarf stellar companion was detected in 2015 at a projected separation of 0.972″ and confirmed in 2016 to be either bound or comoving.
Planetary system
In 2011 a transiting hot Jupiter planet b was detected on a nearly circular orbit. The planetary equilibrium temperature is 1384 K. No orbital decay was detected as in 2018, despite the close proximity of the planet to the host star.
References
Andromeda (constellation)
G-type main-sequence stars
Binary stars
Planetary systems with one confirmed planet
Planetary transit variables
J00520018+3443422 | HAT-P-28 | [
"Astronomy"
] | 219 | [
"Andromeda (constellation)",
"Constellations"
] |
55,905,013 | https://en.wikipedia.org/wiki/Jorge%20Nocedal | Jorge Nocedal (born 1950) is an applied mathematician, computer scientist and the Walter P. Murphy professor at Northwestern University who in 2017 received the John Von Neumann Theory Prize. He was elected a member of the National Academy of Engineering in 2020.
Nocedal specializes in nonlinear optimization, both in the deterministic and stochastic setting. The motivation for his current algorithmic and theoretical research stems from applications in image and speech recognition, recommendation systems, and search engines. In the past, he has also worked on equilibrium problems with application in robotics, traffics, and games, optimization applications in finance, as well as PDE-constrained optimization.
Biography
Nocedal was born and raised in Mexico. He obtained a B.Sc. in physics from the National University of Mexico in 1974. From 1974 to 1978, Nocedal studied at Rice University, where he obtained a PhD in mathematical sciences under the supervision of Richard A. Tapia. Prior to joining Northwestern University in 1983, Nocedal spent three years (1978–1981) as an assistant professor at the National University of Mexico and two years (1981–1983) as a research assistant at the Courant Institute of Mathematical Sciences at NYU. Nocedal joined the Electrical Engineering and Computer Sciences department at Northwestern University in 1983. He held this appointment until 2012, before joining the Industrial Engineering and Management Sciences department, where he served as the David and Karen Sachs Professor and Chair from 2013 to 2017.
Contributions
Nocedal is well-known for his research in nonlinear optimization, particularly for his work on L-BFGS and his textbook Numerical Optimization.
In 2001, Nocedal co-founded Ziena Optimization Inc. and co-developed the KNITRO software package. Nocedal was a chief scientist at Ziena Optimization Inc. from 2002 to 2012 before the company was subsequently bought by Artelys in 2015.
Awards and honors
Nocedal has won numerous awards in the fields of nonlinear optimization, applied mathematics and operations research. In 1998, he was an invited speaker to the International Congress of Mathematicians in Berlin. He was named an ISI Highly Cited Researcher in 2004. He received the George B. Dantzig Prize in 2012 and the Charles Broyden Prize in 2009. He was also named a SIAM Fellow in 2010. In 2017, he received the INFORMS John Von Neumann Theory Prize. Nocedal was elected a member of the National Academy of Engineering in 2020 for contributions to the theory, design, and implementation of optimization algorithms and machine learning software.
References
External links
Nocedal's home page at Northwestern
Department of Industrial Engineering and Management Sciences at Northwestern University
Publications from Google Scholar
1952 births
Rice University alumni
Applied mathematicians
Northwestern University faculty
20th-century Mexican mathematicians
21st-century Mexican mathematicians
Expatriate academics in the United States
Fellows of the Society for Industrial and Applied Mathematics
John von Neumann Theory Prize winners
Living people | Jorge Nocedal | [
"Mathematics"
] | 586 | [
"Applied mathematics",
"Applied mathematicians"
] |
55,906,423 | https://en.wikipedia.org/wiki/Gunda%20Georg | Gunda I. Georg is a chemist who is currently the Professor and Head of the Department of Medicinal Chemistry, Regents Professor, McKnight Presidential Chair, Robert Vince Endowed Chair at University of Minnesota and a former Co-Editor-in-Chief of American Chemical Society's Journal of Medicinal Chemistry. Her research interests are total synthesis and semisynthesis as well as evaluating biologically active agents. A cited expert in her field, she was elected to the American Association for the Advancement of Science in 1996 and inducted in the Medicinal Chemistry Hall of Fame in 2017. In 2019, she was announced as the 2020 winner and first woman to receive the Alfred Burger Award in Medicinal Chemistry (established by GlaxoSmithKline, now sponsored by Gilead). She along with chemists, Shameem Syeda and Gustavo Blanco, are leading researchers in male contraception. Dr Georg also works with her research groups to conduct research on Alzheimer's disease, epilepsy and cancer experimental therapeutics.
Education
She earned her B.S. in 1975 and Ph.D. in 1980 from Philipps Universitat Marburg.
Career
Georg is the Principal Investigator for a National Institutes of Health Center grant for the Contraceptive Discovery, Development and Behavioral Research Center funded from 2017 to 2021. The grant work is in five interdisciplinary groups that are working on the discovery and development of non-hormonal male contraceptive agents and the investigation of contraceptive use.
Georg's work is described in over 250 peer-reviewed publications and she holds a number of patents.
She co-authored a book with Lednicer and Mitscher (RIP).
Her medical contributions include polishing off Gamendazole, Lonidamine and Pregnenolyne derivatives.
Selected publications
Hawkinson, J. E.; Sinville, R.; Mudaliar, D.; Shetty, J.; Ward, T.; Herr, J. C.; Georg, G. I. Potent Pyrimidine and Pyrrolopyrimidine Inhibitors of Testis-Specific Serine/Threonine Kinase 2 (TSSK2). ChemMedChem 2017. .
Ayoub, A.; Hawk, M. L.; Herzig, R. J.; Wisniewski, A. J.; Gee, C. Zhu, J.-Y.; Berndt, N.; Scott, T. G.; Qi, J.; Jun, Q.; Bradner, J. E.; Ward, T. R.; Schönbrunn, E.; Georg, G. I.; Pomerantz, W. C. K. BET Bromodomain Inhibitors with One-step Synthesis Discovered from a Virtual Screen. J. Med. Chem. 2017, 60, 4805–4817.
Syeda, S. S.; Carlson, E. J.; Miller, M. R.; Francis, R.; David E. Clapham, D. E.; Lishko, P. V.; Hawkinson, J. E.; Hook, D.; Georg, G. I. The Fungal Sexual Pheromone Sirenin Activates the Human CatSper Channel Complex. ACS Chem. Biol. 2016, 11, 452–459.
Patil, S.; Lis, L. G.; Schumacher, R. J.; Norris, B. J.; Morgan, M. L.; Cuellar, R. A. D.; Blazar, B. R.; Suryanarayanan, R.; Gurvich, V. J.; Georg, G. I. Phosphonooxymethyl Prodrug of Triptolide: Synthesis, Physicochemical Characterization, and Efficacy in Human Colon adenocarcinoma and Ovarian Cancer. J. Med. Chem. 2015, 58, 9334–9344.
Syeda, S. S.; Jakkaraj, S.; Georg, G. I. Scalable synthesis of the BET bromodomain inhibitor JQ1. Tetrahedron Lett. 2015, 56, 3454–3457.
Coulup, S. K.; Huang, D. S.; Wong, H. L.; Georg, G. I. Identification of the Metabolic Profile of the α-Tubulin-binding Natural Product (-)-Pironetin. J. Med. Chem. 2019, 62, 1684–1689.
Jakkaraj, S. R.; Young, V. G.; Georg, G. I. Syntheses of PDE3A Inhibitor ORG9935 and Determination of the Absolute Stereochemistries of its Enantiomers by X-ray Crystallography. Tetrahedron 2018, 74, 2769–2774.
Miao, Z.; Guan, X.; Jiang, J.; Georg, G. I. BRDT Inhibitors for Male Contraceptive Drug Discovery: Current Status. In Targeting Protein-Protein Interactions by Small Molecules. Editors C. Sheng and G. I. Georg; Springer Nature Singapore; 2018, Chapter 11, pp 287–315.
Paulson,C. N.; Guan,X.; Ayoub,A. M.; Chan, A.; Karim, R. M.; Pomerantz,W. K. C.; Schönbrunn, E.; Georg,G. I.; Hawkinson, J. E.Design, Synthesis and Characterization of a Pan-BET Fluorescent Polarization Bromodomain Probe. ACS Med. Chem. Lett. 2018, 9, 1223–12229.
References
External links
Fellows of the American Association for the Advancement of Science
University of Minnesota faculty
21st-century American chemists
American Chemical Society
Living people
University of Marburg alumni
Year of birth missing (living people) | Gunda Georg | [
"Chemistry"
] | 1,235 | [
"American Chemical Society"
] |
55,906,881 | https://en.wikipedia.org/wiki/Cyborg%20data%20mining | Cyborg data mining is the practice of collecting data produced by an implantable device that monitors bodily processes for commercial interests. As an android is a human-like robot, a cyborg, on the other hand, is an organism whose physiological functioning is aided by or dependent upon a mechanical/electronic device that relies on some sort of feedback.
Implantable cybernetics and biomechatronics are on course to be proliferated among the global population within the twenty-first century as the markets for implantable electronics are already huge and growing. The global market for artificial cardiac pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) was approximately €8 billion in 2015, and is growing at 10% per year. Over 350 million people worldwide experience endemic diseases, diabetes, cardiac and renal failure, hearing disorders, and neurological disorders, thus making implantable technologies specific to these uses susceptible to increasingly higher demand. However, for the millions of cyborgs already equipped with body-enhancing technologies, namely PMs and ICDs, the data mining of these technologies pertains to broader topics of data sovereignty, data ownership rights, privacy and security, and medical research and development.
Implantable technologies and their general uses
According to European Directive 90/385/EEC, an "active implantable medical device" is any device that is intended to be used for human beings in the: 1) diagnosis, prevention, monitoring, treatment, or alleviation of disease or injury; 2) investigation, replacement, or modification of the anatomy or of a physiological process; and 3) control of conception. The implantable device is to be totally or partially introduced, surgically or medically, into the human body, and is intended to remain after the procedure.
According to one definition of the term cyborg, basic technologies, such as implantable medical devices, that humanity has physical attachments with have already made humans into cyborgs. These technologies are responsible for enhancing people's cognitive abilities, or more importantly, keeping them alive. The three most common implantable technologies are cochlear implants, PMs, and ICDs. Cochlear implants aid in the process of hearing, and are used by more than 200,000 patients worldwide. PMs and ICDs keep people alive through the measurement of bodily voltage levels, measurement of regular and irregular heartbeats, and the delivery of electric impulses when irregularities are sensed in order to keep the person alive. There are about 3 million people worldwide with pacemakers, and each year 600,000 pacemakers are implanted. The data collected from these technologies, however, is not owned by the person whose body the technology is in, but rather the company who owns the intellectual property to that technology, as well as other third-parties.
Intellectual property, data brokerage, and the third-party doctrine
Intellectual property and data brokerage
Companies are now able to mine the data exhaust from internet-enabled wearable and implantable technologies, such as medical and fitness tracking devices (Fitbit, Apple Watch Nike+, etc.), sensors, PMs, RFID (Radio Frequency Identification) microchips, and so forth. However, consumers in the U.S. do not have agency over their data due to current intellectual property law and the third-party doctrine. Intellectual property owners of the software, as well as the patented hardware and processes, of these devices acquire the data from the cyborg's bodily processes via these implantable devices, which become property of the owner, not the cyborg. Consumers surrender these massive pools of data via an End-User-License-Agreement (EULAs), terms of service agreements, and so forth. Companies then algorithmically arrange data, and consumers lose ownership of their data to the intellectual property owners and data brokerage firms to commodify, thus becoming a part of the larger Big Data economy. In a $300 billion-a-year industry, currently no legislation specific to the regulation of third-party data broker firms exists. Third-party data broker firms are not restricted by Federal Trade Commission regulations, including the Fair Credit Reporting Act, as well as the Gramm-Leach-Bliley Act. It is very difficult for consumers to opt-in and out of having data collected about them, whereby their data ownership rights become very limited.
Third-party doctrine
Under the third-party doctrine, an individual does not have a reasonable expectation of privacy with respect to information they voluntarily disclose to a third party. In the context of the PM, which monitors a patient's heartbeat, blood temperature, breathing, and heart electrical activity, this extracted data is voluntarily given to a third party, and thus subject to the third-party doctrine. The five largest PM manufacturers in the world are the U.S.’s Medtronic ($1.9 billion in global PM sales in 2013), St. Jude Medical (nearly $1 billion in global PM sales in 2013), and Boston Scientific ($514 million in global PM sales in 2013), Germany's Biotronik ($397 million in global PM sales in 2013), and Italy's Sorin Group ($219 million global PM sales in 2013). PM users have no agency over their data, nor over who has the ability to access it, and current laws impose no requirement for manufacturers to allow PM users access to their own data. The notable activist, Hugo Campo, has been fighting for the right to access the data collected by his own defibrillator for years without success due to the logic of PM data being covered by the third-party doctrine.
EU GDPR and cyborg data
In April 2016, the European Union tabled legislation for the General Data Protection Regulation (GDPR), which will replace the Data Protection Directive 95/46/EC of 1995, and comes into force on May 25, 2018. Internet-enabled wearable and future implantable technologies will fall under the purview of this legislation. The directive will implement tougher fines for non-compliance and breaches, and gives consumers more control over how their personal data is used. Some of these consumer rights are, but are not limited to, having the right:
To request data in monthly intervals;
To access any information a company holds on them;
To know why that data is being processed;
To know how long it is stored for;
To know who gets to see their data;
To demand that their data be deleted if it is no longer necessary to the purpose for which it was collected; and so forth
Surveillance and sousveillance
As cyborgs are comprehensive data subjects, they can also be used as a powerful instrument to facilitate surveillance and sousveillance through optical recording technology. Some data collection from cyborgs can be harmless, namely posting pictures to Facebook, or recording one's life experiences. However, cyborgs can serve as a means of surveillance on the overall populace via sousveillance. Sousveillance is the notion of a populace watching the state from below, whereby the notable University of Toronto professor and cyborg, Steve Mann, has advocated that sousveillant devices can “invert the panopticon” and challenge and balance the hypocrisy and corruption that is otherwise inherent in a surveillance-only society. Sousveillant technologies secure the cyborg and individuals, especially by deterring and documenting crime, but potentially infringes privacy on cyborgs and non-cyborgs as well. Google Glass, for example, is an optical recording device that presents concerns toward privacy in public. The ability for cyborgs to record everyday routines and interactions with others thus present the question of how society and laws are to respond to the advent of cyborgs being subjects and instruments of surveillance and sousveillance.
Public good
Data mined from bodily processes are able to help companies in their research and development endeavours in developing better technologies, and conducting invaluable medical research for identifying and managing various conditions. PMs and ICDs offered by major companies come with wireless capabilities that communicate with home transmitters, which then relay data to the physician, and thus allow for remote patient follow-up and monitoring. These systems for remote follow-up are used widely across the U.S. and Europe. Major PM and ICD producers have their own remote monitoring system networks, such as Biotronik's Home Monitoring, Medtronic's CareLink Network, Boston Scientific's Latitude Patient Management system, and St. Jude Medical's Merlin.net. The benefits of this data collection include a reduction of in-clinic visits, improved patient safety, increased patient satisfaction, and potential cost savings for consumers. The ability to remotely follow up because of PM and ICD data collection allows for tracking product performance in a large number of patients, and may allow earlier identification of issues with specific models.
The data collected from PMs and ICDs have the potential to facilitate critical medical research. Namely, Medtronic collects and analyzes the data generated by its pacemakers and defibrillators via the CareLink system. Medtronic is using the collected PM data and is working with researchers at Johns Hopkins Hospital and Washington University School of Medicine in order to help answer specific questions about heart disease, such as whether weak hearts cause arrhythmias or vice versa. Although this aspect of the technology is not widely proliferated yet, scientists and industry developers say that wireless devices could trigger an automatic treatment, which could range from electrical stimulation to the release of drugs.
References
Cybernetics
Cyborgs
Data mining | Cyborg data mining | [
"Biology"
] | 1,967 | [
"Cyborgs"
] |
55,907,189 | https://en.wikipedia.org/wiki/Hecke%20algebra | In mathematics, the Hecke algebra is the algebra generated by Hecke operators, which are named after Erich Hecke.
Properties
The algebra is a commutative ring.
In the classical elliptic modular form theory, the Hecke operators Tn with n coprime to the level acting on the space of cusp forms of a given weight are self-adjoint with respect to the Petersson inner product. Therefore, the spectral theorem implies that there is a basis of modular forms that are eigenfunctions for these Hecke operators. Each of these basic forms possesses an Euler product. More precisely, its Mellin transform is the Dirichlet series that has Euler products with the local factor for each prime p is the reciprocal of the Hecke polynomial, a quadratic polynomial in p−s. In the case treated by Mordell, the space of cusp forms of weight 12 with respect to the full modular group is one-dimensional. It follows that the Ramanujan form has an Euler product and establishes the multiplicativity of τ(n).
Generalizations
The classical Hecke algebra has been generalized to other settings, such as the Hecke algebra of a locally compact group and spherical Hecke algebra that arise when modular forms and other automorphic forms are viewed using adelic groups. These play a central role in the Langlands correspondence.
The derived Hecke algebra is a further generalization of Hecke algebras to derived functors. It was introduced by Peter Schneider in 2015 who, together with Rachel Ollivier, used them to study the p-adic Langlands correspondence. It is the subject of several conjectures on the cohomology of arithmetic groups by Akshay Venkatesh and his collaborators.
See also
Abstract algebra
Wiles's proof of Fermat's Last Theorem
Notes
References
Abstract algebra
Number theory
Modular forms | Hecke algebra | [
"Mathematics"
] | 384 | [
"Discrete mathematics",
"Algebra stubs",
"Abstract algebra",
"Number theory",
"Modular forms",
"Algebra"
] |
55,907,272 | https://en.wikipedia.org/wiki/Hecke%20algebra%20of%20a%20finite%20group | The Hecke algebra of a finite group is the algebra spanned by the double cosets HgH of a subgroup H of a finite group G. It is a special case of a Hecke algebra of a locally compact group.
Definition
Let F be a field of characteristic zero, G a finite group and H a subgroup of G. Let denote the
group algebra of G: the space of F-valued functions on G with the multiplication given by convolution. We write for the space of F-valued functions on . An (F-valued) function on G/H determines and is determined by a function on G that is invariant under the right action of H. That is, there is the natural identification:
Similarly, there is the identification
given by sending a G-linear map f to the value of f evaluated at the characteristic function of H. For each double coset , let denote the characteristic function of it. Then those 's form a basis of R.
Application in representation theory
Let be any finite-dimensional complex representation of a finite group G, the Hecke algebra is the algebra of G-equivariant endomorphisms of V. For each irreducible representation of G, the action of H on V preserves – the isotypic component of – and commutes with as a G action.
See also
Gelfand pair
References
Claudio Procesi (2007) Lie Groups: an approach through invariants and representations, Springer, .
Mark Reeder (2011) Notes on representations of finite groups, notes.
Algebras
Representation theory of Lie groups | Hecke algebra of a finite group | [
"Mathematics"
] | 323 | [
"Algebras",
"Mathematical structures",
"Algebraic structures"
] |
55,907,584 | https://en.wikipedia.org/wiki/TyrT%20operon | The tyrT operon is a series of genes encoding the tRNA for tyrosine in Escherichia coli. It is activated in response to amino acid starvation.
Components
The tyrT operon consists of an upstream activation sequence, the gene for the tyrosine tRNA called tRNA1Tyr, and an RNA called rtT RNA which has an unknown function.
Regulation
Transcription of the tyrT operon is activated by the stringent response. Binding of the FIS protein to the operon's upstream activation sequence tightly bends the DNA, promoting transcription.
References
Escherichia coli genes
Operons | TyrT operon | [
"Chemistry"
] | 127 | [
"Operons",
"Gene expression"
] |
55,907,709 | https://en.wikipedia.org/wiki/Cris%20Thomas | Cris Thomas (also known as Space Rogue) is an American cybersecurity researcher, white hat hacker, and award winning
best selling author. A founding member and researcher at the high-profile hacker security think tank L0pht Heavy Industries, Thomas was one of seven L0pht members who testified before the U.S. Senate Committee on Governmental Affairs (1998) on the topic of government and homeland computer security, specifically warning of internet vulnerabilities and claiming that the group could "take down the internet within 30 minutes".
Subsequently, Thomas pursued a career in Cyber Security Research while also embracing a public advocacy role as a cyber security subject-matter expert (SME) and pundit. Granting interviews and contributing articles, Space Rogue's advocacy has served to educate and advise corporations, government, and the Public about security concerns and relative risk in the areas of election integrity, cyber terrorism, technology, the anticipation of new risks associated with society's adoption of the Internet of things, and balancing perspective (risk vs. hype).
Career
Cyber Security
A founding member of the hacker think tank L0pht Heavy Industries, Thomas was the first of L0pht's members to leave following the merger of L0pht with @Stake in 2000, and the last to reveal his true name. Thomas was one of seven L0pht members who testified before the U.S. Senate Committee on Governmental Affairs (1999). Testifying under his internet handle, Space Rogue, the testimony of Thomas and other L0pht members served to inform the government of current and future internet vulnerabilities to which federal and public channels were susceptible. The testimony marked the first time that persons not under federal witness protection were permitted to testify under assumed names.
While at the L0pht Thomas created The Whacked Mac Archives and The Hacker News Network. In addition he released at least one security advisories detailing a flaw in FWB's Hard Disk Toolkit.
Thomas continued a career in Cyber Security Research at @Stake, Guardent, Trustwave (Spiderlabs), Tenable, and IBM (X-Force Red). Selected to serve as a panelist during a 2016 Atlantic Council cyber risk discussion series, and a webinar speaker for the National Science Foundation's WATCH series, Thomas has embraced a public advocacy role as a cyber security subject-matter expert (SME) and pundit, granting interviews and contributing articles to educate the public about security concerns and relative risk. Topics include election integrity, cyber terrorism, technology, password security, the anticipation of new risks associated with society's adoption of the Internet of things, and balancing perspective (risk vs. hype).
In response to a 2016 United States Government Accountability Office report revealing the nation's nuclear weapons were under the control of computers that relied on outdated 8" floppy disks, Thomas argued that the older computers, data storage systems, programming languages, and lack of internet connectivity would make it more difficult for hackers to access the systems, effectively reducing the vulnerability of the weapon control systems to hacking.
Following cyber security mega-breaches at Target, Home Depot, and the U.S. Office of Personnel Management, Thomas advocated for proactive implementation of basic security measures as the most effective means to thwart similar mega-threats. Bluntly stating that the gap between knowledge and implementation leaves companies and individuals at unnecessary risk, Thomas’ recommendation focused on simple measures that have been known for one to two decades, but which organizations have not implemented universally. Thomas had identified retail cyber security breaches, including that at FAO Schwarz, as early as 1999.
In 2017, at the Defcon hacker conference Thomas assisted with escorting Rep. Will Hurd (R) and Rep. Jim Langevin (D) around the conference area through the various villages.
At Defcon 27 in 2019 Thomas appeared on a panel with Rep. Langevin (D-RI), Rep. Lieu (D-CA), and former Rep. Jane Harman entitled "Hacking Congress: The Enemy of My Enemy Is My Friend."
During the panel Thomas was quoted as saying “It’s up to us as a community to engage with those people…to educate them”, "But Congress doesn't work that way; it doesn't work at the 'speed of hack'. If you're going to engage with it, you need to recognize this is an incremental journey” and “it takes 20 years to go from hackers in Congress to Congress at DEF CON”.
The Whacked Mac Archives
The Whacked Mac Archives was an FTP download site managed by Thomas with the world's largest collection of Apple Macintosh hacking tools. The total size of all the tools on the site was 20MB.
A CD copy of the contents of the FTP site was advertised for sale in 2600: The Hacker Quarterly.
Hacker News Network
Serving as Editor-in-Chief, Thomas founded and managed L0pht's online newsletter and website, known as the Hacker News Network (or simply Hacker News or HNN). Originally created to rapidly share discoveries about computer security, Hacker News also became a forum for users to post security alerts as vulnerabilities were identified. The publication grew, eventually supporting paid advertising and an audience that included technology journalists and companies with an interest in cybersecurity. The website can be seen in several background shots of the video "Solar Sunrise: Dawn of a New Threat" produced by the National Counterintelligence Center in 1999.
After L0pht's merger with @Stake in 2000, the Responsible disclosure-focused Hacker News Network was replaced with Security News Network.
Hacker News Network, after a decade offline, set for a launch on Jan. 11, 2010, with video reports about security, the last videos were published in 2011. Hacker News Network in 2018 redirects to spacerogue.net
CyberSquirrel1 (CS1)
In 2013, Thomas created the project CyberSquirrel1 as a satirical demonstration of the relative risk of Cyberwarfare attacks on critical infrastructure elements such as the North American electrical grid. Started as a Twitter feed, the CyberSquirrel1 project expanded to include a full website and CyberSquirrel Tracking Map; as the dataset grew, Attrition.org's Brian Martin (alias “Jared E. Richo” a/k/a Jericho) joined the project in 2014. CyberSquirrel1's results disrupted public perception regarding the prevalence of nation-based hacking cyberwarfare attacks, concluding that damage due to cyberwarfare (for example, Stuxnet) was "tiny compared to the cyber-threat caused by animals", referring to electrical disruptions caused by squirrels.
An archive containing the full data set and supporting material of the project was uploaded to the Internet Archive under the Creative Commons license on January 19, 2021.
Election Security
As the 2015-2016 alleged Russian interference in the 2016 United States elections unfolded, public and media interest in hacking and hackers increased. Leading up to the 2016 election, Thomas was interviewed for mainstream media productions, including CNBC's On the Money.
After the release of the Joint Analysis Report, Thomas called for expanded detail on Indicators of Compromise in Federal Joint Analysis Reports, indicating that increased transparency and IP address reporting were instrumental for enhancing security.
Prior to the 2018 election Thomas continued his advocacy speaking with CBS News and other outlets about securing our elections and the vulnerability of voting machines.
Books
In February 2023 Thomas released his first book, Space Rogue: How the Hackers Known as L0pht Changed the World.
Written as a personal memoir, the book detailed his childhood growing up in Maine, how he discovered the online world of BBS’s and met the other members of the hacker collective L0pht Heavy Industries. The book covers how the L0pht released security vulnerability information, created L0phtcrack, gained media recognition, and testified in front of Congress in 1998. The book also covers the L0pht’s transition to the security consultancy @Stake, and how the L0pht’s impact still ripples throughout the information security industry today.
The book spent several weeks in the Amazon top 10 in the Computer & Technology Biographies category and briefly hit number 1. The book was a finalist in the 2023 International Book Awards. and a winner of the 2023 National Indie Excellence Awards (NIEA).
References
External links
Cybersquirrel1 website & event tracking map
Space Rogue (Cris Thomas) personal website
L0pht
Living people
Hackers
Writers about computer security
American computer scientists
Year of birth missing (living people) | Cris Thomas | [
"Technology"
] | 1,781 | [
"Lists of people in STEM fields",
"Hackers"
] |
55,907,806 | https://en.wikipedia.org/wiki/IEEE%201849 | The IEEE STANDARD 1849-2016, IEEE Standard for eXtensible Event Stream (XES) for Achieving Interoperability in Event Logs and Event Streams, is a technical standard developed by the IEEE Standards Association. It standardizes "a language to transport, store, and exchange (possibly large volumes of) event data (e.g., for process mining)". In 2023, the standard has been revised in and superseded by the IEEE Standard 1849-2023.
Process mining aims to discover, monitor and improve processes by extracting knowledge from event logs representing actual process executions in a given setting. Process mining depends on the availability of accurate and unambiguous event logs, according to established standards. The purpose of this standard is to provide a generally acknowledged (W3C) XML format for the interchange of event data between information systems in many applications domains on the one hand and analysis tools for such data on the other hand. As such, this standard aims to fix the syntax and the semantics of the event data which, for example, is being transferred from the site generating this data to the site analyzing this data. As a result of this standard, if the event data is transferred using the syntax as described by this standard, its semantics will be well understood and clear at both sites.
IEEE 1849 was the second IEEE Standard Sponsored by the IEEE Computational Intelligence Society. The first was IEEE 1855.
IEEE Standard 1849-2023
The 2023 revision of the standard has been approved on the 5th of June 2023 and introduces the following changes:
new Micro, Software Event, Software Communication, Software Telemetry, and Artifact Lifecycle extensions
updated lists of tools supporting the standard, event logs using the standard, and publications that mention the standard
updated XES Schema definition, fixing a flaw related to the position of the log attributes
updated bibliography
References
External links
IEEE standards
Data management | IEEE 1849 | [
"Technology"
] | 379 | [
"Data management",
"Computer standards",
"IEEE standards",
"Data"
] |
55,907,997 | https://en.wikipedia.org/wiki/Ovulatory%20shift%20hypothesis | The ovulatory shift hypothesis holds that women experience evolutionarily adaptive changes in subconscious thoughts and behaviors related to mating during different parts of the ovulatory cycle. It suggests that what women want, in terms of men, changes throughout the menstrual cycle. Two meta-analyses published in 2014 reached opposing conclusions on whether the existing evidence was robust enough to support the prediction that women's mate preferences change across the cycle. A newer 2018 review does not show women changing the type of men they desire at different times in their fertility cycle.
Overview
The theory proposes that women's behavior may change during the most fertile time in their ovulatory cycle. At high fertility, the theory holds that women may become more physically active and avoid male relatives.
The hypothesis separately proposes that hormonal changes across the cycle cause women, when they are most likely to get pregnant, to be more attracted to traits in potential short-term male sexual partners that indicate high genetic quality, leading to greater reproductive success. It has been proposed that genetic traits like compatible major histocompatibility complex gene profiles are considered more attractive. Newer studies do not support female changes in desired reproductive partners when more fertile.
Estrus in humans
Most female mammals experience reproductive fertility cycles. They typically consist of a long period of low fertility, and a brief period of high fertility just prior to and including ovulation. In humans, this is called the ovulatory cycle, or menstrual cycle. The period of high fertility is also called the fertile window, and is the only time during the cycle when sex can result in conception.
Females of most mammalian species display hormonally-induced physical and behavioral signals of their fertility during the fertile window, such as sexual swellings and increased motivation to mate. Some species will not—or cannot—engage in sex at all outside of this window. This phase of sexual receptivity and proceptivity, estrus, is often referred to as being "in heat".
Human females, however, engage in sex throughout their ovulatory cycles, and even beyond their reproductive years. Additionally, they do not show obvious physical signals of high fertility. This has led many researchers to conclude that humans lost their estrus through evolution. It has been hypothesized that this could be due to the adaptive benefits of concealed ovulation and extended sexuality.
However, research has shown that human females may in fact experience subtle but distinct physiological, behavioral, and cognitive changes during the high-fertility phase of their ovulatory cycle, and that both men and other women can detect signals that indicate high-fertility in a woman, which may indicate that humans have retained an estrus-like state.
Evolution of ovulatory cycle shifts
Estrus evolved to facilitate reproduction and maximize reproductive success, or the success of passing on one's genes by producing offspring that are most likely to survive and reproduce themselves. The ovulatory shift hypothesis proposes that motivation and desire to mate should increase during the fertile window, and that females should seek and attract the best possible mate at their highest fertility. An ideal mate could have many qualities: resources to care for offspring, the physical ability and social status to protect a mate and offspring, a compatible personality for a long-term pair bond, etc. Evolutionary theory and sexual selection theory suggest that an organism's top priority should be to maximize survival and reproductive success. Thus, the ovulatory shift hypothesis proposes that women possess a dual sexuality, where during the fertile window, a woman should prioritize attracting and choosing a mate with the best genetic quality, or “good genes”, since this is the only time she can become pregnant and pass on heritable genetic qualities to her offspring. However, at low-fertility, a woman should prioritize a mate with "good parenting" traits, such as willingness and ability to invest in parenting, resources to devote to offspring, and compatibility for a long-term partnership. These differing traits are sometimes referred to as the "sexy cad" vs. the "good dad".
It has also been hypothesized that high-fertility preferences should be strongest when evaluating a short-term sexual partner, but low-fertility preferences should be strongest when evaluating a long-term relationship partner. A woman can gain the benefits of good genes through only a single sexual encounter, and good dad traits are only relevant for a long-term pair bond.
Some researchers have suggested that over evolutionary time, women may have maximized reproductive success by seeking good genes from an extra-pair copulation—cheating on their partner—at high fertility, while also maintaining a long-term pair bond with a partner who provides parenting resources for the offspring, sometimes called the dual strategy hypothesis. Of course, an optimal partner is one with both sexy cad and good dad traits, but such a man is statistically unlikely to be common. Thus, natural selection may have designed ancestral women to be opportunistic. If successful, a woman could gain the benefits of both high-quality genetics and high-quality parenting to give her offspring the best chance of survival. However, natural selection would not have favored men who desire to provide for offspring that do not share their genes, so this would have been a risky strategy.
Mechanisms
Ovulatory cycle shifts are hypothesized to be regulated by sex hormones, primarily estradiol and progesterone, which become elevated at different times across the cycle. In particular, high levels of estradiol and low levels of progesterone, which peak at high fertility just prior to ovulation, have been shown to be correlated with several mating-related psychological changes. However, some studies have only found correlations with changes in estradiol. It is well-established that estradiol can act in the brain to produce other psychological and behavioral changes, and animal studies tend to show a link between sexual behavior and estrogen concentrations. Other hormones such as testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin have been studied as possible correlates, but most have produced little to no effect.
Changes in cognition and behavior across the ovulatory cycle
Numerous studies have demonstrated ovulatory cycle shifts in women's mating-related motivations, preferences, thoughts, and behaviors. The ovulatory shift hypothesis proposes that these shifts are designed by natural selection as evolutionary adaptations for selecting and attracting specific types of mates with high genetic quality when a woman is most likely to get pregnant.
Sexual desire
Some of the earliest studies on human ovulatory shifts explored whether women engage in more instances of sexual activity during high fertility, as this could indicate a human estrus-like state. While some studies have found increases in frequency of sexual activity at high fertility, larger studies have concluded that there is generally no difference in frequency of sexual activity across the ovulatory cycle, possibly due to the multitude of factors that affect the ability to engage in sex (e.g., access to a partner, partner's desire, time for engaging, etc.).
Researchers have subsequently explored whether sexual desire, rather than frequency of sexual activity, changes across the ovulatory cycle, as this would not be affected by practical barriers to engaging in sex. Several studies in this area have shown that women's sexual desire and masturbation behaviors do increase during the fertile window, although results have been mixed and depend on the type of sexual desire measured. For example, desire for uncommitted sex does not appear to track fertility.
Relationship satisfaction
While some studies have shown that fertile-phase women might be more attracted to, flirt more, and initiate sex more often with men who are not their partner, newer studies do not support the hypothesis that females change who they consider desirable reproductive partners when more fertile.
Women in relationships may tend to be more assertive and independent during the fertile phase.
Attraction and mate preferences
The ovulatory shift hypothesis proposes that women at high fertility should be most attracted to short-term sexual partners with physical and behavioral features that likely signal genetic fitness, or good genes.
Symmetry
Having symmetrical features may indicate that an individual possesses high-quality genes related to health, and that they developed in a stable environment with little disease or trauma. Studies have found that women rate faces of more symmetrical men as more attractive during high fertility, especially when evaluating them as short-term partners. It has also been demonstrated that women at high fertility are more attracted to the body odors of men with more facial and bodily symmetry. Although many studies and one meta-analysis have shown that fertility-moderated shifts in attraction to facial and bodily symmetry occur robustly, other reviews have concluded that the effect is small or non-existent.
Masculinity
In many species, more masculine and dominant males experience greater reproductive success. Masculine traits are produced during puberty by increasing amounts of testosterone. Testosterone is a known immunosuppressant, thus traits that reflect high levels of testosterone may indicate that a man possesses high-quality genes which allowed him to develop masculine features without experiencing any deleterious effects of high testosterone levels. Masculine traits include facial features like a strong jawline, bodily features like height, muscularity, and body hair, and vocal features like a deeper voice. While many studies have shown that women tend to be attracted to more masculine characteristics at high fertility, results have been mixed, and two meta-analyses have concluded that the effect is not robust.
Creativity
Charles Darwin first proposed that music, lacking a functional evolutionary explanation by natural selection, may be an instrument of sexual selection, just like a male peacock's extravagant feathers, which serve to attract a female. Similarly, humans may use artistic expressions as a display of good genetic qualities like creativity and intelligence.
Compatible genes
The major histocompatibility complex (MHC) is a suite of genes responsible for adaptive immune response and histocompatibility in an organism's cells. In animals, including mammals and other primates, MHC has been shown to play a role in MHC sexual selection, where organisms mate selectively with individuals who possess MHC alleles that are more dissimilar from their own. MHC has been shown to be responsible for changing the pheromone compositions of mice, causing mice with dissimilar MHC genes to have more attractive body odors. It has been hypothesized that this is a mechanism for creating genetic diversity, avoiding inbreeding, and creating offspring that are more resistant to pathogens. Some studies have shown that humans tend to form long-term partnerships with individuals who have more dissimilar MHC, and find the scent of MHC-dissimilar individuals more attractive, especially at high fertility. However, other studies have found little or no effect of MHC on mate preferences, and some have even shown a reverse effect, that people prefer partners with more similar MHC to their own. Several reviews and one meta-analysis on the human and primate literature regarding MHC have concluded that the effects of MHC similarity on attraction are not robust, but that humans are reliably attracted to individuals with more heterozygous, or diverse, MHC genotypes, regardless of whether they are similar to their own. However, it is unclear whether attraction to MHC heterozygosity changes across the ovulatory cycle.
Clothing and grooming
The ovulatory shift hypothesis proposes that women's behavior during the fertile phase should also reflect evolutionary adaptations for reproductive success. Fertile-phase women also spend more time on their appearance and tend to wear accessories like jewelry, makeup, or hairstyles that are perceived as trying to look more attractive. Additionally, several studies have demonstrated that women tend to purchase more products related to enhancing their appearance, attractive clothing, shoes, or accessories, during the fertile window.
Activity and food consumption
One of the earliest studies on ovulatory shifts found that female lab rats tend to run on their exercise wheels more during their fertile window. Subsequent research showed that a variety of species experience an increase in the frequency of spontaneous activity and motor behavior during estrus. Some studies on humans have shown a similar pattern: women walk more steps, as counted by a pedometer, during the high-fertility phase of their cycle. However, other research has found no difference in locomotion patterns across the ovulatory cycle, and many studies on activity across the cycle have small sample sizes and substantially differing methodologies, making it difficult to draw definitive conclusions. Despite a possible increase in activity, many studies have found that women consume fewer calories during their fertile phase. Some researchers have suggested that these changes in activity and food consumption may indicate that during estrus, women are motivated to focus more of their energy on mating-related behaviors like going out to meet new potential mates, instead of survival-related behaviors like seeking food.
Competitiveness with other women
Parental investment theory posits the idea that natural selection designed each sex to have different mating strategies based on how much investment the sex is required to devote to offspring for their survival. The sex that invests more in offspring should be more intersexually selective, or picky when choosing a sexual partner, because they have more time and resources to lose if they make a poor choice. The other sex should be more intrasexually competitive, or competitive with members of their same sex, in order to access and attract the more selective sex. In humans, as in all mammals, females are the sex that invests more in parenting, simply through the lengthy and taxing process of pregnancy and lactation, whereas males need only to contribute one act of sexual intercourse to pass on their genes. Thus, females are expected to be the more selective sex, and males are expected to be more competitive. However, unlike many species where males do not contribute to parenting at all, humans have highly dependent offspring, and a complex social structure that allows males to make significant and important investments in parenting effort. According to parental investment theory, this indicates that natural selection may have designed women to be somewhat competitive with other women for access to the best mates and potential fathers for their offspring.
Some studies have indicated that women engage in more competitive behaviors with other women when they are at high fertility. During the fertile window, women not using hormonal contraceptives self-report increased feelings of intrasexual competitiveness, describe other women as less attractive, and use more dehumanizing terms when talking about women, but not men. Women's choices to purchase more attractive or revealing clothing at high fertility are also increased when they are first shown a photograph of an attractive woman, but not photographs of men or unattractive women, suggesting clothing may not be chosen to attract men, but rather as a competitive display for other women. Additionally, some studies have used economic games to show that women are less likely to share resources or engage in cooperative bargaining with other women during the fertile window. Some researchers have noted that the reason why women should be more competitive during the fertile window is unclear.
The ovulatory shift hypothesis proposes that women should be seeking short-term sexual partners at peak fertility, but men can effectively have multiple sexual partners, so competition over one high-quality man should not be necessary. If women were competing for a long-term partner, there is no reason why they should be more competitive during the fertile window than any other time in their cycle.
Ovulatory cycle shifts
Hassleton and Gildersleeve (2011) wrote that both men and women can subconsciously detect cues to women's fertility that change across the ovulatory cycle. Some researchers have suggested that natural selection designed women to signal their fertility in order to attract a mate. Other researchers have proposed that women evolved to have concealed ovulation but they still "leak" subtle cues of their fertility, and men have evolved to detect these cues.
Body odor
During estrus, many species produce pheromones, or body odors that indicate to potential mates that one is in the fertile phase. While no specific human pheromones have been identified, humans may exhibit similar scent changes at high fertility. Body odors of high-fertility women not using hormonal contraceptives are rated in some studies as more attractive by both men and women. Vaginal odors from high-fertility women are also rated as more attractive than odors from the same women at low-fertility. Some studies have shown that men exposed to high-fertility body odors of women exhibit increases in testosterone, a feature associated with mating motivation and behavior, although other studies have failed to replicate this effect.
Physical attractiveness
Studies using facial photographs found that both men and women rate physical features of women at high fertility more attractive than when they are at low fertility and that facial attractiveness increases in fertile phase women. It has been hypothesized that this shift may be due to subtle changes in soft tissue symmetry that increase during high-fertility.
Vocal pitch
Studies have found that fertile phase women speak with a slightly higher vocal pitch. One study reported that recordings of women's voices in the fertile phase are rated, by both men and women, as more attractive than recordings by the same women during low fertility. However, these effect sizes are relatively small compared to other cues of ovulation.
Partner jealousy
Several studies have found that men in a relationship tend to be more protective and possessive of their partner when she is at peak fertility, as well as more jealous of any advances their partner might make on other men. One study found that after interacting with their partner during the fertile phase, men shown a photograph of an attractive man exhibit increased testosterone, which may be a competitive response.
Effects of hormonal contraception
Since it has been proposed that changes in hormone levels across the ovulatory cycle are the primary mechanisms that causes cycle shifts, some studies have explored the effects of hormonal contraception, like the pill, on both women's cycle shifts and other people's ability to detect cycle shifts.
Studies have reported that hormonal contraceptives weaken or eliminate cycle shifts entirely. It has been proposed that the synthetic hormones present in hormonal contraception that suppress ovulation also suppress the subsequent cognitive and behavioral changes found in naturally-cycling women. Other studies have stated that changes in synthetic hormones produce cycle shifts similar to effects produced by the real hormonal changes in naturally-cycling women.
Alternative hypotheses
Within-cycle vs. between-cycle shifts
While the ovulatory shift hypothesis proposes that adaptive changes in mating-related cognition and behavior occur within each ovulatory cycle, some researchers have posited a between-cycle shift theory. Many women experience regular anovulatory cycles, or non-fertile cycles where ovulation does not occur, therefore hormonal changes between ovulatory cycles may be a more reliable indicator of true fertility, as higher levels of estradiol are more likely to produce a fertile ovulatory cycle. Thus, some researchers have proposed that hormonal changes between cycles, primarily in elevated estradiol levels, are responsible for changes in mating-related cognition and behavior. Within-cycle shifts may be simply a byproduct of between-cycle shifts caused by elevated estradiol.
Meta-analyses and reviews
One meta-analysis and a review of the literature have been conducted on both published and unpublished data that support the claim of the ovulatory shift hypothesis that women experience changes in attraction preferences at high fertility. However, another meta-analysis and subsequent commentary concluded that the effect is not actually significant and may be a result of some studies using imprecise measurements of when women are in the fertile window, as well as publication bias. A review subsequently published also does not show women changing the type of men they desire at different times in their fertility cycle. Another study found no correlation between current fertility status and sociosexual attitudes and desires.
See also
References
Human evolution
Menstrual cycle
Evolutionary psychology
Evolutionary biology
Biological anthropology
Women and sexuality
Biological hypotheses | Ovulatory shift hypothesis | [
"Biology"
] | 4,118 | [
"Biological hypotheses",
"Evolutionary biology"
] |
55,909,465 | https://en.wikipedia.org/wiki/Andrea%20Goldsmith%20%28engineer%29 | Andrea Goldsmith is an American electrical engineer and the Dean of Engineering and Applied Science at Princeton University. She is also the Arthur LeGrand Doty Professor of Electrical Engineering at Princeton. She was previously the Stephen Harris Professor in the School of Engineering at Stanford University, as well as a faculty affiliate at the Stanford Neurosciences Institute. Her interests are in the design, analysis and fundamental performance limits of wireless systems and networks, and in the application of communication theory and signal processing to neuroscience. She also co-founded and served as chief technology officer of Plume WiFi and Quantenna Communications. Since 2021, she has been a member of the President’s Council of Advisors on Science and Technology (PCAST).
Early life and education
Goldsmith was raised in the San Fernando Valley, California. Her father Werner Goldsmith was a professor of mechanical engineering at UC Berkeley, and her mother Adrienne Goldsmith was an animator for cartoon shows, including The Rocky and Bullwinkle Show. Goldsmith earned her bachelor's degree in engineering math from the University of California, Berkeley, in 1986, and her MS and PhD in electrical engineering from UC Berkeley in 1991 and 1994, respectively. In the years between obtaining her bachelor's and PhD, she spent four years as a systems engineer at a Silicon Valley defense communications startup.
Work and academic career
Goldsmith started her academic career at the California Institute of Technology and was there for four years. She joined Stanford in 1999, becoming an associate professor in 2002 and a full professor in 2007. At Stanford, she has served as chair of the faculty senate, and on the school's task force on women and leadership. In 2006, she took a leave of absence from Stanford and co-founded Quantenna Communications, a company that produces silicon chipsets designed for high-speed, wireless high-definition video home networking. She served as chief technology officer of the startup until returning to Stanford in 2008. She was also a founder and CTO of Plume Wi-Fi, which was founded in 2014 and develops Wi-Fi technology. She joined Princeton in 2020 as Dean of Engineering and Applied Science at a pivotal time, where it is expected to grow its engineering faculty by 50%, build a new neighborhood with new buildings for all engineering departments and interdisciplinary institutes, and foster significantly more innovation, entrepreneurship, and partnerships with industry.
As an inventor and consultant, she has secured 29 patents. She has authored and co-authored several books, including Wireless Communication, MIMO Wireless Communications and Principles of Cognitive Radio. She has launched and led several multi-university research projects, including DARPA's ITMANET program, and she is a principal investigator in the National Science Foundation Center on the Science of Information.
In the IEEE, Goldsmith served on the board of governors for both the Information Theory and Communications societies. She has also been a distinguished lecturer for both societies, served as president of the IEEE Information Theory Society in 2009, founded and chaired the Student Committee of the IEEE Information Theory Society, and chaired the Emerging Technology Committee of the IEEE Communications Society. She chairs the IEEE Committee on Diversity and Inclusion.
She won the 2017 Women in Communications Engineering Mentorship Award from the IEEE Communications Society for her efforts in encouraging women in the fields of technology and engineering. In 2017, she was elected to the Academy of Arts and Sciences, and also to the National Academy of Engineering for contributions to adaptive and multiantenna wireless communications. Goldsmith won the 2020 Marconi Prize, generally recognized as the top prize in communications.
Awards
IEEE fellow for contributions to the development of adaptive techniques and the analysis of fundamental capacity limits for wireless communication systems in the year 2005.
National Academy of Engineering Gilbreth Lecture Award, 2002
Silicon Valley Business Journal Women of Influence Award, 2010
IEEE Communications Society Edwin H. Armstrong Achievement Award, 2014
Member, National Academy of Engineering, 2017–present
Member, American Academy of Arts and Sciences, 2017–present
Women in Communications Engineering (WICE) Mentorship Award, 2017
ACM Athena Lecturer Award, 2018
Marconi Prize, 2020
Publications
Books and book chapters
Entropy, Mutual Information, and Capacity for Markov Channels with General Inputs, T. Holliday, A. Goldsmith, P. Glynn, Stanford University Press, 2002
EE359 Wireless Communications, A. Goldsmith, Stanford University Press, 2002
Wireless Communications, A. Goldsmith, Cambridge University Press, 2005
MIMO Wireless Communications, E. Biglieri, Cambridge University Press, 2007
Principles of Cognitive Radio, A. Goldsmith, L. Greenstein, N. Mandayam, H.V. Poor, Cambridge University Press, 2012
Personal life
Goldsmith lives in Menlo Park, California, with her husband, scientist Arturo Salz, and their children.
External links
People of ACM.
Google Scholar, Andrea Goldsmith
Andrea Goldsmith Profile at Stanford University
References
Living people
American electrical engineers
Stanford University faculty
Local area networks
Wireless networking
American women computer scientists
American computer scientists
People from Menlo Park, California
Scientists from California
UC Berkeley College of Engineering alumni
California Institute of Technology faculty
Electrical engineering academics
Fellows of the American Academy of Arts and Sciences
Fellows of the Royal Academy of Engineering
Female fellows of the Royal Academy of Engineering
Stanford University Department of Electrical Engineering faculty
Engineers from California
Year of birth missing (living people)
American telecommunications engineers
American women academics
21st-century American engineers
21st-century American women engineers | Andrea Goldsmith (engineer) | [
"Technology",
"Engineering"
] | 1,070 | [
"Wireless networking",
"Computer networks engineering"
] |
55,909,655 | https://en.wikipedia.org/wiki/Lignosus%20cameronensis | Lignosus cameronensis is a species of poroid fungus in the family Polyporaceae. Its fruit bodies have a roughly circular brown cap measuring up to in diameter, supported by a muddy brown stipe up to long and thick. The pores on the cap underside are tiny, numbering two to four per millimetre.
Described as a new species in 2013, it is found in the tropical forests of Pahang, Malaysia. The specific epithet cameronensis refers to the type locality, the Cameron Highlands. The fungus fruit bodies are similar in appearance to those of Lignosus ekombitii, but differs in having smaller spores that typically measure 2.4–4.8 by 1.9–3.2 μm.
References
Polyporaceae
Fungi described in 2013
Fungi of Asia
Fungus species | Lignosus cameronensis | [
"Biology"
] | 163 | [
"Fungi",
"Fungus species"
] |
55,909,718 | https://en.wikipedia.org/wiki/Triangulane | A triangulane is a hydrocarbon consisting exclusively of a series of spiro-linked cyclopropane rings.
Triangulanes are named according to the rules of systematic nomenclature for spiro compounds. The pattern of their common names is "[n]triangulane", where n is the number of cyclopropane units. The simplest such chemical, [2]triangulane, is named spiro[2.2]pentane by systematic nomenclature. Chains consisting of four or more cyclopropane units—[4]triangulane and higher—can form chiral helices. This property is unusual for a molecule that contains no stereogenic atoms; the chiral nature is due to restricted mobility of the chain ends analogous to helicene molecules.
The rings can form a branched or cyclic patterns. For example, [3]rotane is a branched [4]triangulane; it consists of one additional cyclopropane attached to the central ring of a [3]triangulane chain.
References
Hydrocarbons
Cyclopropanes
Spiro compounds | Triangulane | [
"Chemistry"
] | 237 | [
"Organic compounds",
"Hydrocarbons",
"Spiro compounds"
] |
55,909,733 | https://en.wikipedia.org/wiki/Russian%20Engineer%20Troops | The Engineer Troops of the Russian Federation () are a Combat Arm and military administrative corps of the Russian Ground Forces of the Russian Federation designed to perform military engineering operations (combat actions), requiring special training of personnel and use of means of engineer equipment, as well as for damaging the enemy through application of engineer ammunition.
Origins
Imperial era
One of the first engineering units founded in the Russian Empire was the Pososhniye lyudi, a collective name for conscripts in the Imperial Russian Army called up for military service from each sokha unit. In the late 17th century, the first engineering training maneuvers were carried out under the patronage of Peter I. The day of the Engineering Forces is recognized as 21 January 1701, with on the opening of the School of the Pushkar Order. The first engineering schools were created in 1708 in Moscow and then in March 1719 in St. Petersburg. The terms of study at these schools ranged from 5 to 12 years. The Imperial Engineering Troops first took part in the Battle of Poltava, the Patriotic War of 1812, Crimean War from 1853 to 1856, and the First World War.
Soviet Engineer Troops
After the February Revolution and the Great October Socialist Revolution of 1917 the newly formed Red Army and Soviet Navy incorporated the sapper units of the former Imperial Russian Army and Navy in their structure. By 1919, pontoon and electrical battalions and a mine-blasting brigade were raised in time for the Civil War. 10 years later, the Engineering Troops of the USSR () were in much better shape and had a much better organization. During the Second World War, ten sapper armies operated, later reorganized into brigades. From the mid-1940s to the 1970s, Engineer-Sapper Companies (ISR) were located in Soviet Army regiments, divisions, and combined-arms armies. Due to miscalculations in planning by the Ministry of Defense of the Soviet Union, there was a shortage of engineering units serving in Afghanistan during the Soviet–Afghan War. In 1986, the Engineering Troops took part in the military response to the biological effects of the Chernobyl accident. After the collapse of the USSR in late 1991, the engineering troops were dissolved and its component units were absorbed by Russia and the newly formed armed forces of nations such as Ukraine, Belarus, Kazakhstan, and Armenia.
Modern history
The official holiday of the Engineering Troops was established by decree of President Boris Yeltsin on 18 September 1996. By order of the Minister of Defense on 23 September 1996, it was prescribed to celebrate the Day of Engineering Troops on January 21 annually.
Mission
In preparation and conduct of combined-arms operations (combat actions) the Engineer Troops perform, among others, the following tasks:
engineer reconnaissance of the enemy, terrain and objects;
construction (arrangement) of fortifications (trenches, ditches and communication trenches, shelters, bunkers, dugouts, tunnels, roadblocks, wire obstacles, defensive fighting positions etc.) and organization of field deployment of troops (residential, logistical, medical);
organisation of engineering obstacles to troop movement, including installation of mine fields, production of blasting, organisation of non-explosive anti-tank obstacles (anti-tank ditches, scarps/counterscarps, stakes, abatis etc.);
clearance of areas and facilities;
preparation and maintenance of traffic routes of troops;
creation and maintenance of ferries across water barriers, including construction of bridges;
extraction and purification of water in the battlefield
In addition, they are involved in countering the intelligence systems and homing of the enemy's weapons (camouflage), simulation of troops and facilities, providing misinformation and demonstrative actions to deceive the enemy as well as to eliminate or reduce the effects of enemy weapons of mass destruction.
In peacetime, the Engineer Troops have a number of important and socially significant tasks: they clean areas of explosive hazards, are involved in the response and liquidation of aftermath of man-made accidents and catastrophes, natural disasters, prevent destruction of bridges and waterworks during floating of ice, etc. Further development of the Engineer Troops is carried out through equipping them with qualitatively new, highly effective, versatile means of engineer equipment, built on the basis of standardised elements, blocks and modules, with a simultaneous decrease of the nomenclature samples of the same type for the intended purpose.
Structure
The Engineer Troops are composed of formations, units and subdivisions for various purposes: engineering-reconnaissance, field engineering, fencing, obstacle clearing, assault-and-traffic engineering, pontoon bridge (pontoon), assault-crossing, camouflage-engineering, technology-engineering, field water supplying ones and so on.
Composition
Directorate of the Commander of the Engineering Troops (Moscow)
1st Guards Engineer-Sapper Brigade (Murom, Western Military District)
11th Guards Engineer Brigade (Kamensk-Shakhtinsky, Southern Military District)
12th Guards Engineer Brigade (Ufa, Central Military District)
14th Guards Engineer Brigade (Vyatskoye, Khabarovsk Krai, Eastern Military District)
45th Guards Engineer Brigade (Murom, Western Military District)
28th Pontoon Bridge Brigade (Murom)
6th Engineer Regiment (Rostov) (1st GTA)
16th Engineer Regiment (Boguchar, 20th GCAA)
24th Engineer Regiment (Kyzyl, 41st GCAA)
30th Engineer Regiment (Kerro, Vsevolozhsky District, 6th CAA)
31st Engineer Regiment (Prokhladny, 58th GCAA)
32nd Engineer Regiment (Afipsky, 49th CAA)
33rd Engineer Regiment (Volgograd, 8th GCAA)
35th Engineer Regiment (Razdolnoe, Primorsky Krai, 5th GCAA)
39th Engineer Regiment (Kizner, 2nd GCAA)
40th Engineer Regiment (Ishim, 41st GCAA)
45th Separate Engineer-Camouflage Regiment (HQ located in Vladimir Oblast; Western Military District; in late 2020 reported at Inzhenernyy 1, 55.793785, 37.192298). Military Unit Number 58142. The regiment's formation was completed in June 2017; as well as the ability to quickly camouflage key facilities, it has "“inflatable models of tanks, guns, infantry fighting vehicles, PVO [air defense] systems, and other weapons systems."
Training centers
66th Interdepartmental Training Methodological Center of Engineering Troops (Nakhabino)
International Mine Action Center (Nakhabino)
187th Interspecific Regional Training Center for the Engineering Troops (Volzhsky),
210th Guards Interspecific Regional Training Center for the Engineering Troops (Kstovo)
Research institutes
Central Research and Testing Institute of Engineering Troops (Nakhabino)
Orthodox Choir and Engineering Troops Ensemble "For Faith and Fatherland"
Educational institutions
Military Engineering Academy
Military Institute (Engineering Troops) of the Combined Arms Academy of the Armed Forces of the Russian Federation
Military Engineering and Technical University
Tyumen Higher Military Engineering Command School named after Marshal of the Engineering Troops Alexey Proshlyakov
Commanders of the Engineering Troops
Colonel General Vladimir Kuznetsov (1992–1999)
Colonel General Nikolai Serdtsev (1999–2008)
Lieutenant General Yuri Balkhovitin (2008–2009)
Colonel Vladimir Prokopchik (interim) (2009–2010)
Lieutenant General Yuri Stavitsky (since July 2010)
References
(Rochan Consulting)
External links
Army units and formations of Russia
Military engineer corps
Engineering units and formations
Military units and formations established in the 1990s | Russian Engineer Troops | [
"Engineering"
] | 1,522 | [
"Engineering units and formations",
"Military engineering",
"Military engineer corps"
] |
55,910,667 | https://en.wikipedia.org/wiki/Erotic%20photography%20model | An erotic photography model or erotic model poses for sensual or erotic photography which is used in exhibitions, art galleries, books, magazines, calendars, as well in other formats, mostly internet, DVDs and magazines. Erotic models pose in an explicit manner, rather than in artistic or implied styles where not everything is shown. The model can pose nude or wear lingerie, swimsuits, etc. No qualifications are required to work as an erotic model beyond being of legal age. The themes used in erotic photoshoots can be diverse, and it is up to the model and photographer to determine what the shoot will entail, so the model has to be aware of their limits.
Erotic photography modelling is sometimes considered to be a type of sex work. It is often combined with other types of sex work as part of the gig economy. Examples include phone sex work, fetish modelling, webcam modelling, pornographic acting, erotic dancing, lap dancing, erotic massage, escorting, sex club hostessing, dominatrix work and sugar dating.
See also
Fetish model
Nude photography
Fine-art photography
Glamour photography
References
Model
Modeling (profession) | Erotic photography model | [
"Biology"
] | 229 | [
"Behavior",
"Sexuality stubs",
"Sexuality"
] |
55,911,046 | https://en.wikipedia.org/wiki/Non-Instrumental%20Movement%20Inhibition | Non-Instrumental Movement Inhibition (NIMI) is an aspect of body language when a person stops fidgeting because they are interested in what they are watching. For example, when a young child is rapt watching a cartoon, they often sit motionless with their mouth open; this motionlessness is NIMI. As such, it is a psychological phenomenon and a form of embodied behavior, where gestures and body movements reflect the thoughts and emotions in a person's mind. This phenomenon is different from almost all other body language because it interprets what does not happen (i.e. an absence of movement) rather than making an interpretation based on a specific gesture.
During NIMI, visual engagement or attention leads subconsciously to lower levels of fidgeting (and other non-instrumental movements).
The movements and actions that are inhibited during NIMI are non-strictly limited to fidgeting only. Non-Instrumental movements are bodily actions that are not related to the goal of the current task; for example, when in a classroom and the goal is to listen to a lecture, attentive listeners will not talk to their neighbors or make a call on their phone. Non-instrumental (unnecessary) movements include fidgeting, scratching, postural micromovements (e.g. sitting forward in a chair), certain emotional expressions (e.g. shrugging), and even breathing. To use breathing as an example, when a person watches a tense movie, they might momentarily stop regular breathing, and this pause is also an example of NIMI. NIMI is important for recognizing boredom
during human-robot interaction, human-computer interaction, computer-aided learning with automated tutoring systems, market research, and experience design.
Historical Evidence
The original observation that, in a seated audience, interest is associated with diminished fidgeting, and that boredom doubles the amount of human movement, was made by Francis Galton in 1885. Modern experiments suggesting that movement inhibition (and NIMI) were quantifiable and related to flow or interest were suggested by a series of papers regarding automated tutoring systems by Sidney D’Mello and colleagues. Using a non-visual task, Paul Seli and collaborators showed that increased episodes of mind wandering led to an increase in fidgeting, presumably because attention requires comparative stillness (maintaining that stillness is described as “a secondary task”). Nadia Bianchi-Berthouze and colleagues demonstrated that engagement in games (and human computer interaction) could lead to either increased movement or decreased movement, depending on the motivational nature of movement tasks involved with the accomplishment of the task. Harry Witchel and colleagues named the inhibitory phenomenon as NIMI, and demonstrated that the visual aspect of the human-computer interaction task was the most powerful contributor to the inhibitory effect on movement. They also demonstrated that, during individual human computer interaction in instrumentally identical reading comprehension tasks, interest itself was sufficient to diminish movement. This was reflected in experiments by Patrick Healy and colleagues in a seated audience at a dance performance.
Controversy
While it is known that frustration and restlessness can lead to increased movement during human computer interaction, it remains controversial as to whether NIMI that occurs during engagement is actually an inhibition of a baseline amount of physiologically required movement.
References
Emotion
Cognition
Attention | Non-Instrumental Movement Inhibition | [
"Biology"
] | 670 | [
"Emotion",
"Behavior",
"Human behavior"
] |
55,911,686 | https://en.wikipedia.org/wiki/Redmi%203 | Redmi 3 was an Android smartphone manufactured by Xiaomi released in January 2016. It had 5-inch HD IPS LCD (294 ppi density), and was powered by Qualcomm's Snapdragon 1.2GHz octa-core Qualcomm Snapdragon 616 processor, paired with 2GB of RAM. It runs on the Android operating system and is equipped with a non-removable 4100mAh battery.
It had a 13-megapixel primary camera, with a 5-megapixel front camera. The device came with MIUI 7, which is based on Android, and has an internal storage capacity of 16GB, which could be expanded via a microSD card up to 128GB. It supported dual-SIM with one Micro-SIM slot and the other as Nano-SIM slot.
It measured 139.30 x 69.60 x 8.50mm (height x width x thickness). The device offered several connectivity options, such as Wi-Fi 802.11 b/g/n, GPS, Bluetooth v4.10, Infrared, USB OTG, FM radio, Wi-Fi Direct, 3G, and 4G. Additionally, it was also equipped with several sensors, including an accelerometer, ambient light sensor, gyroscope, proximity sensor, and compass/magnetometer.
The Xiaomi Redmi 3 was later succeeded by its successor, the Redmi 3S.
References
3
Mobile phones introduced in 2016
Android (operating system) devices
Discontinued smartphones
Mobile phones with infrared transmitter | Redmi 3 | [
"Technology"
] | 324 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
55,912,118 | https://en.wikipedia.org/wiki/European%20Solar%20Physics%20Division | The European Solar Physics Division (ESPD) of the European Physical Society (EPS), is an organisation whose purpose is to promote solar physics and represent European scientists interested in the physics of the Sun. The ESPD is known mostly for its organisation of the European Solar Physics Meetings, which bring together European solar physicists and take place every three years.
Since 2017, the ESPD awards four prizes: the Zdeněk Švetka Senior Prize for outstanding contributions over an extended period of time to solar physics, the Giancarlo Noci Early Career Prize for outstanding contributions to solar physics from an Early career researcher, the Patricia Edwin PhD Prize for the best European PhD thesis in solar physics and the Kees Zwaan Inspirational Community Prize for services to the community.
History
In 1974, solar physicists in Europe recognised the need for common meetings and the "European Solar Meeting Organising Committee" was created, with the first European Solar Physics Meeting organised in 1975. This meeting was attended by more than 200 solar physicists (a remarkable number for the time), and during the meeting it was decided to proceed with the creation of a Solar Physics Section (SPS) as part of the Astronomy and Astrophysics Division of the EPS.
In 1990, the European Astronomical Society (EAS) was founded, and the SPS became a section of the Joint Astrophysics Division (JAD) of EPS and EAS. In 2009 the SPS became the European Solar Physics Division, an EPS division in its own right.
Meetings
The ESPD organises the European Solar Physics Meeting (ESPM), the largest meeting of solar physics in Europe. They are held every three years. The following European Solar Physics Meetings have taken place:
1975: ESPM-1, Florence, Italy
1978: ESPM-2, Toulouse, France
1981: ESPM-3, Oxford, United Kingdom
1984: ESPM-4, Noordwijkerhout, Netherlands
1987: ESPM-5, Titisee, Germany
1990: ESPM-6, Debrecen, Hungary
1993: ESPM-7, Catania, Italy
1996: ESPM-8, Thessaloniki, Greece
1999: ESPM-9, Florence, Italy
2002: ESPM-10, Prague, Czech Republic
2005: ESPM-11, Leuven, Belgium
2008: ESPM-12, Freiburg, Germany
2011: ESPM-13, Rhodes, Greece
2014: ESPM-14, Dublin, Ireland
2017: ESPM-15, Budapest, Hungary
2021: ESPM-16, virtual conference
2024: ESPM-17, Turin, Italy
Besides, the European Solar Physics Meeting, the ESPD has also been associated with the organisation of the China–Europe Solar Physics Meeting. The following meetings have taken place:
2016: 1st China–Europe Solar Physics Meeting, Kunming, China
2018: 2nd China-Europe Solar Physics Meeting, Hvar, Croatia
Summer Schools
The ESPD organises the ESPD Summer School in Solar Physics, every two years. The following ESPD Summer Schools have taken place
2024 ESPD Summer School on Energisation and heating in the solar plasma, Dubrovnik, Croatia
See also
List of astronomical societies
References
External links
ESPM-14
ESPM-15
ESPM-16
ESPM-17
1st China–Europe Solar Physics Meeting
2nd China–Europe Solar Physics Meeting
Astronomy in Europe
Astronomy organizations
Pan-European scientific societies
Physics organizations | European Solar Physics Division | [
"Astronomy"
] | 696 | [
"Astronomy organizations"
] |
55,912,265 | https://en.wikipedia.org/wiki/Lignosus%20tigris | Lignosus tigris is a species of poroid fungus in the family Polyporaceae. Its fruit bodies have a roughly circular, brown to ochre cap measuring up to in diameter, supported by a muddy-brown stipe up to long and thick. The honeycomb-like pores on the cap underside number 1–2 per millimetre.
Described as a new species in 2013 by mycologist Chon-Seng Tan, it is found in the tropical forests of Pahang, Malaysia. The specific epithet tigris alludes to the local folklore that the fungus originated from milk dripped onto the ground while a tigress fed her cubs. The fungus fruit bodies are similar in appearance to those of Lignosus sacer, but differs in having larger pores, and smaller spores that typically measure 2.5–5.5 by 1.8–3.6 μm.
References
Polyporaceae
Fungi described in 2013
Fungi of Asia
Fungus species | Lignosus tigris | [
"Biology"
] | 199 | [
"Fungi",
"Fungus species"
] |
55,912,405 | https://en.wikipedia.org/wiki/Lignosus%20dimiticus | Lignosus dimiticus is a species of poroid fungus in the family Polyporaceae found in Zaire. Its fruit body features a funnel-shaped cap up to in diameter and in the centre. The smooth, white stipe has a woody texture, and measures long and thick. Unlike other members of Lignosus, L. dimiticus has a dimitic hyphal system, as it lacks binding hyphae in its trama and context.
References
Polyporaceae
Fungi described in 1975
Fungi of Africa
Taxa named by Leif Ryvarden
Fungus species | Lignosus dimiticus | [
"Biology"
] | 118 | [
"Fungi",
"Fungus species"
] |
55,912,752 | https://en.wikipedia.org/wiki/Tomasz%20Robert%20Taylor | Tomasz Robert Taylor (born February 23, 1954) is a Polish-American theoretical physicist and faculty at Northeastern University in Boston, Massachusetts, United States of America. He obtained his PhD degree from the University of Warsaw, Poland in 1981 under the supervision of Stefan Pokorski. He is a descendant of John Taylor who originated from Fraserburgh in Scotland and emigrated to the Polish-Lithuanian Commonwealth c.1676.
He is known for his discovery, with Stephen Parke, of Parke–Taylor amplitudes, also known as maximally helicity violating (MHV) amplitudes; his pioneering use of supersymmetry for computing scattering amplitudes in quantum chromodynamics; his seminal work, with Ignatios Antoniadis, Edi Gava and Kumar Narain, on topological string amplitudes; his formulation, with Ignatios Antoniadis and Hervé Partouche, of the first four-dimensional quantum field theory with partial supersymmetry breaking; his extensive studies, with Stephan Stieberger, of superstring scattering amplitudes.
Honors
2009 Fellowship of the American Physical Society
2015 Membership in the Polish Academy of Learning
References
External links
MHV@30: Amplitudes and Modern Applications
Scientific publications of Tomasz Robert Taylor on INSPIRE-HEP
1954 births
Living people
Theoretical physicists
Mathematical physicists
People associated with CERN
People associated with Fermilab
Polish scientists
University of Warsaw alumni
Members of the Polish Academy of Learning | Tomasz Robert Taylor | [
"Physics"
] | 296 | [
"Theoretical physics",
"Theoretical physicists"
] |
55,912,876 | https://en.wikipedia.org/wiki/MyCujoo | MyCujoo was a video streaming platform providing live and on-demand broadcast of football matches, sports events, and highlights from around the world. Founded in 2014, and launched in 2015 by brothers Pedro and João Presa, and specialising in the long tail of football, MyCujoo provided a platform and channels for teams, leagues, and federations to broadcast their own content including streaming live merely by using a cellphone.
Customers included the Canadian Soccer Association, Jordan Football Association, Football Association of Indonesia,Myanmar National League, the Japan Women's Football League, Fluminense Football Club, the Football Association of Singapore, the Asian Football Confederation, the Bhutan Football Federation, the All Nepal Football Association, the Football Federation Islamic Republic of Iran, ADO Den Haag, US Soccer, the Football Association of Thailand, the Brazilian Football Confederation, the Oceania Football Confederation, the Lebanon Football Association, United Women's Soccer, Beach Soccer Worldwide (BSWW), National Independent Soccer Association, National Premier Soccer League, Federação Paulista de Futebol and Campeonato Brasileiro Série D.
According to the company, beginning with its inaugural partnership with FC Zürich Frauen, MyCujoo grew from streaming 56 games in 2015 to over 300 by the end of the first quarter in 2017, and by the end of the year approximately 4,200 games had been broadcast from 60 countries with roughly 40 million viewers. Since its partnership with the AFC launched in 2016 there have been 1,544 matches streamed from AFC member association territories, reaching nearly 19 million viewers in over 122 countries. In October 2018, the company was the subject of an Amazon Studios documentary, and in November 2018 was described by the Financial Times as one of Europe's 100 digital champions.
In January 2019, it was announced that MyCujoo had concluded a five year agreement with the International Hockey Federation to provide a dedicated OTT solution, and had been the subject of investment from Sapphire Ventures.
In November 2020, both MyCujoo's direct to consumer live football streaming platform and business to business streaming MyCujoo Live Services were acquired by Eleven Sports, and in June 2021 the direct to consumer platform transformed into a global live and on-demand sports and entertainment platform. In July 2023, ELEVEN's global OTT was discontinued, ending MyCujoo's position as a direct to consumer streaming platform.
In September 2022, Eleven Sports, was acquired by direct-to-consumer live football streaming platform DAZN.
References
External links
ELEVEN Sports (Global) on YouTube
DAZN
Association football websites
Streaming media systems | MyCujoo | [
"Technology"
] | 530 | [
"Streaming media systems",
"Telecommunications systems",
"Computer systems"
] |
55,914,590 | https://en.wikipedia.org/wiki/Dunlap%20Institute%20for%20Astronomy%20%26%20Astrophysics | The Dunlap Institute for Astronomy and Astrophysics at the University of Toronto is an astronomical research centre.
The institute was founded in 2008 with the help of endowed gifts to the University of Toronto from David M. Dunlap and J. Moffat Dunlap, using the proceeds from the sale of the David Dunlap Observatory. The Dunlap Institute is allied with and co-located with the University of Toronto's Department of Astronomy & Astrophysics and with the Canadian Institute for Theoretical Astrophysics, and no longer has any association or connection to the David Dunlap Observatory.
Research
Astronomers at the Dunlap Institute investigate a variety of topics including:
the structure of the Milky Way Galaxy
cosmic magnetic fields
cosmic explosions
the large scale structure in the universe
Dark Energy
the Cosmic Microwave Background
Technology & Instrumentation
Telescope, instrumentation and software projects with leadership from Dunlap scientists include:
The Dragonfly Telephoto Array, which comprises many telephoto lens and is designed to detect dim astronomical objects. Dragonfly was co-designed by the U of T's Roberto Abraham and Yale's Pieter van Dokkum.
The Canadian Hydrogen Intensity Mapping Experiment (CHIME)
The South Pole Telescope, designed to study the Cosmic Microwave Background from its location at the South Pole
The Gemini InfraRed Multi-Object Spectrograph (GIRMOS), to be deployed on the Gemini South telescope in Chile in 2024
The Canadian Initiative for Radio Astronomy Data Analysis (CIRADA), which is producing advanced data products for the CHIME, ASKAP and VLA radio telescopes, and which is a pilot project for a Canadian Square Kilometre Array data centre.
Training
At the Dunlap's annual Introduction to Astronomical Instrumentation Summer School, undergraduate and graduate students from around the world attend lectures and labs. Undergraduate students also pursue summer research projects at the Dunlap Institute's Summer Undergraduate Research Program.
Public outreach
The Dunlap Institute runs many public outreach events including:
Astronomy on Tap TO
SpaceTime
Cool Cosmos (part of the International Year of Astronomy in 2009)
Transit of Venus viewing (2012)
Toronto Science Festival (in partnership with U of T Science Engagement) (2013)
Dunlap Prize Lecture featuring Neil deGrasse Tyson (2014)
Supermoon Lunar Eclipse viewing (2015)
Partial Solar Eclipse viewing (2017)
Planet gazing parties, in partnership with the Royal Astronomical Society of Canada
Directors
2010 - 2012: James R. Graham
2012 – 2015: Peter Martin (Acting/Interim)
2015 – present: Bryan Gaensler
References
University of Toronto
Astronomy institutes and departments
Astrophysics research institutes | Dunlap Institute for Astronomy & Astrophysics | [
"Physics",
"Astronomy"
] | 521 | [
"Astronomy organizations",
"Astrophysics research institutes",
"Astrophysics",
"Astronomy institutes and departments"
] |
55,914,847 | https://en.wikipedia.org/wiki/NGC%20684 | NGC 684 is a spiral galaxy approximately 135 million light-years away from Earth in the constellation of Triangulum. It was discovered by William Herschel on October 26, 1786. Edward Swift, Lewis' son, found this galaxy again on 18 Jan 1890 while "searching for Swift's Comet." and it was reported as a new object in list IX-6.
One supernova has been observed in NGC 684: SN2021ass (typeII, mag. 18.1).
See also
Spiral galaxy
List of NGC objects (1–1000)
Triangulum (constellation)
References
External links
SEDS
Spiral galaxies
Triangulum
684
006759
IC objects
Astronomical objects discovered in 1786
Discoveries by William Herschel
+04-05-017 | NGC 684 | [
"Astronomy"
] | 159 | [
"Triangulum",
"Constellations"
] |
55,915,558 | https://en.wikipedia.org/wiki/ZTE%20Max%20Duo | The ZTE Max Duo LTE is a phablet smartphone designed, developed, and marketed by ZTE. The phone was released in August 2015.
Specifications
General specs
Software
The ZTE Max Duo runs Android Lollipop 5.1.1 launched in 2014.
See also
List of Android devices
ZTE
List of ZTE products
ZTE Blade
References
External links
Official website
Phablets
Android (operating system) devices
Mobile phones introduced in 2015 | ZTE Max Duo | [
"Technology"
] | 92 | [
"Crossover devices",
"Phablets"
] |
55,915,676 | https://en.wikipedia.org/wiki/Journal%20of%20Comparative%20Physiology%20A | The Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology is a bi-monthly peer-reviewed scientific journal covering the intersection of ethology, neuroscience, and physiology. It was founded in 1924 by Karl von Frisch and Alfred Kühn under its German title Zeitschrift für vergleichende Physiologie. To indicate its global orientation, it changed its name to Journal of Comparative Physiology in 1972. Reflecting the trend toward specialization in the sciences, it split into two daughter journals, 'A' and 'B', in 1976. The editor-in-chief is Günther K.H. Zupanc (Northeastern University).
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 2.1.
References
External links
Ethology journals
Physiology journals
Neuroscience journals
Academic journals established in 1984
Monthly journals
English-language journals
Springer Science+Business Media academic journals | Journal of Comparative Physiology A | [
"Biology"
] | 213 | [
"Ethology",
"Behavior",
"Ethology journals"
] |
55,915,817 | https://en.wikipedia.org/wiki/NGC%20498 | NGC 498 is a lenticular galaxy located about 260 million light-years away from Earth, in the constellation Pisces. NGC 498 was discovered by astronomer R. J. Mitchell on October 23, 1856.
NGC 498 is a member of the NGC 507 Group which is part of the Perseus–Pisces Supercluster.
See also
Lenticular galaxy
List of NGC objects (1–1000)
References
External links
Lenticular galaxies
Pisces (constellation)
0498
5059
Astronomical objects discovered in 1856
Discoveries by R. J. Mitchell (astronomer)
Perseus-Pisces Supercluster | NGC 498 | [
"Astronomy"
] | 132 | [
"Pisces (constellation)",
"Constellations"
] |
44,285,917 | https://en.wikipedia.org/wiki/Local%20adaptation | Local adaptation is a mechanism in evolutionary biology whereby a population of organisms evolves to be more well-suited to its local environment than other members of the same species that live elsewhere. Local adaptation requires that different populations of the same species experience different natural selection. For example, if a species lives across a wide range of temperatures, populations from warm areas may have better heat tolerance than populations of the same species that live in the cold part of its geographic range.
Definition
More formally, a population is said to be locally adapted if organisms in that population have evolved different phenotypes than other populations of the same species, and local phenotypes have higher fitness in their home environment compared to individuals that originate from other locations in the species range. This is sometimes called 'home site advantage'. A stricter definition of local adaptation requires 'reciprocal home site advantage', where for a pair of populations each out performs the other in its home site. This definition requires that local adaptation result in a fitness trade-off, such that adapting to one environment comes at the cost of poorer performance in a different environment. Before 2004, reciprocal transplants sometimes considered populations locally adapted if the population experienced its highest fitness in its home site vs the foreign site (i.e. compared the same population at multiple sites, vs. multiple populations at the same site). This definition of local adaptation has been largely abandoned after Kawecki and Ebert argued convincingly that populations could be adapted to poor-quality sites but still experience higher fitness if moved to a more benign site (right panel of figure).
Testing for local adaptation
Testing for local adaptation requires measuring the fitness of organisms from one population in both their local environment and in foreign environments. This is often done using transplant experiments. Using the stricter definition of reciprocal home site advantage, local adaptation is often tested via reciprocal transplant experiments. In reciprocal transplants, organisms from one population are transplanted into another population, and vice versa, and their fitness is measured (see figure). If local transplants outperform (i.e. have higher fitness than) the foreign transplants at both sites, the local populations are said to be locally adapted. If local adaptation is defined simply as a home site advantage of one population (local sources outperform foreign sources at a common site), it can be tested for using common garden experiments, where multiple source populations are grown in a common site, as long as one of the source populations is local to that site.
Transplant experiments have most often been done with plants or other organisms that do not move. However, evidence for rapid local adaptation in mobile animals has been gathered through transplant experiments with Trinidadian guppies.
Frequency of local adaptation
Several meta-analyses have attempted to quantify how common local adaptation is, and generally reach similar conclusions. Roughly 75% of transplant experiments (mostly with plants) find that local populations outcompete foreign populations at a common site, but less than 50% find the reciprocal home site advantage that defines classic local adaptation. Exotic plants are locally adapted to their invasive range as often and as strongly as native plant are locally adapted, suggesting that local adaptation can evolve relatively rapidly. However, biologists likely test for local adaptation where they expect to find it. Thus these numbers likely reflect local adaptation between obviously differing sites, rather than the probability than any two randomly-selected populations within a species are locally adapted.
Drivers of local adaptation
Any component of the environment can drive local adaptation, as long as it affects fitness differently at different sites (creating divergent selection among sites), and does so consistently enough for populations to evolve in response. Seminal examples of local adaptation come from plants that adapted to different elevations or to tolerate heavy metals in soils. Interactions among species (e.g. herbivore-plant interactions) can also drive local adaptation, though do not seem to be as important as abiotic factors, at least for plants in temperate ecosystems. Many examples of local adaptation exist in host-parasite systems as well. For instance, a host may be resistant to a locally-abundant pathogen or parasite, but conspecific hosts from elsewhere where that pathogen is not abundant may have no evolved no such adaptation.
Effects of Gene Flow on Local Adaptation
Gene flow can completely prevent local adaptations in populations by increasing the amount of genetic material exchanged which can than lower the frequency of alleles associated with the specific local adaptation. However gene flow can also introduce beneficial alleles to a population, which increases the amount of genetic variation, therefore strengthening the likelihood of local adaptations. Gene flow is the transfer of genetic information from one population to another, mainly through migration of organisms or their genetic material. It is possible for genetic material such as pollen or spores that can travel via wind, water or being brought by an animal, to reach an isolated population.
The role gene flow plays in local adaptation is complex because gene flow can reduce the likelihood of local adaptation in a population since gene flow is genetic material from different populations mixing frequently, which makes populations genetically more similar which is the opposite of local adaptation. The level of gene flow impacts its effects on local adaptation, high gene flow tends to reduce local adaptation whereas low gene flow can increase local adaptation. High gene flow is when there is a lot of new genetic material entering the population often and low gene flow is when a population occasionally gets new genetic material. Populations with extensive local adaptations are the most impacted by high gene flow; in such cases where high gene flow occurs in populations with local adaptations it has negative effects such as reducing or removing the adaptation.
Populations with local adaptation can be isolated from other populations however complete isolation is not necessary, gene flow can play a role in populations developing local adaptations. Gene flow allows for the introduction of new beneficial alleles into populations where it was not previously present; if these end up being extremely beneficial to the population they were introduced to, this may allow organisms to locally adapt. Further, local adaptation can happen under gene flow if recombination at genes connected to or controlling the adapted trait is reduced.
Field Observations
Paper Wasps: Parasite & Host Relationship
The effect of high gene flow on local adaptation in populations co-evolving with a parasite is of particular interest because parasites are known to specialize on a given host. Populations of coevolving wasps were studied, a type of paper wasps (Polistes biglumis) and the parasite wasp (Polistes atrimandibularis) that preys on it, the parasite essentially takes over the nest of the host and begins to reproduce, eventually taking over the host’s nest. The specific type of parasitism taking place between these two wasp species is social parasitism, meaning one species gets another species to raise its young; social parasitism is known to impact genetic diversity of the host populations. A specific local adaptation of the P. biglumis is having a small number of offspring and putting more energy towards defenses against potential intruders, which would help prevent the parasitic wasp from entering the nest.
Looking at different local populations with similar levels of gene flow is particularly important because the presence of local adaptations in some populations but not others could suggest factors other than gene flow and selective pressure from parasites are causing the differences. Further, regional populations with varying levels of gene flow allows us to get a better idea of how gene flow at the local population level within these regions contributes to local adaptations at the regional level. The Alps were chosen as the area for the wasp study because the elevation of the mountains separate regional and local populations; resulting in multiple local populations of both host and parasite at different elevations and regions. For example, wasps on the same mountain but at different elevations do interbred so gene flow is occurring between local populations. In addition, there are also more isolated regional populations of both host wasp and parasitic wasp on completely different mountains that do not interbreed with other regional populations. DNA microsatellites, a type of genetic marker, were used to study the differences between local populations, to compare to regional populations, in an attempt to see how gene flow was impacting their genetics. What's very important to note is that gene flow is taking place between wasp populations to the same degree; all local populations in the same region have the same amount of gene flow. Meaning that one host population does not have more exposure to different additional genetic material than another host population at a different elevation.
The wasp study found that significant local adaptation only took place in different regional populations, rather than different local populations, for instance higher and lower elevation populations on the same side of the mountain did not have significant differences. But populations in different regions, on the other side of the mountain, a completely different mountain, did have significant differences. Results from the DNA microsatellites showed that the out of the regional wasp populations, the most isolated regional population was the most different from other regional populations. This evidence supports the idea that some level of isolation is needed in order for local adaptations to occur within populations, further supporting the idea that high levels of gene flow do not produce local adaptations.
Experimental Evidence
Fruit Flies
Experimental data suggests limited gene flow will produce the most local adaptations and high gene flow will cause populations to hybridize. There was study done on fruit flies (Drosophila melanogaster) to see if adaptive potential was increased in populations that were previously isolated and then experienced different levels of gene flow, or complete hybridization between two populations of previously isolated fruit flies. Experiments introducing different levels of gene flow and complete hydration of D. melanogaster populations showed that limited gene flow (in comparison to high gene flow or full hybridization) was actually what produced the greatest number of beneficial alleles within the fruit fly population.
See also
References
Evolutionary biology | Local adaptation | [
"Biology"
] | 1,968 | [
"Evolutionary biology"
] |
44,286,896 | https://en.wikipedia.org/wiki/Growth%20curve%20%28statistics%29 | The growth curve model in statistics is a specific multivariate linear model, also known as GMANOVA (Generalized Multivariate Analysis-Of-Variance). It generalizes MANOVA by allowing post-matrices, as seen in the definition.
Definition
Growth curve model: Let X be a p×n random matrix corresponding to the observations, A a p×q within design matrix with q ≤ p, B a q×k parameter matrix, C a k×n between individual design matrix with rank(C) + p ≤ n and let Σ be a positive-definite p×p matrix. Then
defines the growth curve model, where A and C are known, B and Σ are unknown, and E is a random matrix distributed as Np,n(0,Ip,n).
This differs from standard MANOVA by the addition of C, a "postmatrix".
History
Many writers have considered the growth curve analysis, among them Wishart (1938), Box (1950) and Rao (1958). Potthoff and Roy in 1964; were the first in analyzing longitudinal data applying GMANOVA models.
Applications
GMANOVA is frequently used for the analysis of surveys, clinical trials, and agricultural data, as well as more recently in the context of Radar adaptive detection.
Other uses
In mathematical statistics, growth curves such as those used in biology are often modeled as being continuous stochastic processes, e.g. as being sample paths that almost surely solve stochastic differential equations. Growth curves have been also applied in forecasting market development. When variables are measured with error, a Latent growth modeling SEM can be used.
Footnotes
References
Analysis of variance
Statistical forecasting
Multivariate time series
Ordinary differential equations
Exponentials
Biostatistics
Growth curves | Growth curve (statistics) | [
"Mathematics"
] | 358 | [
"E (mathematical constant)",
"Exponentials"
] |
44,287,236 | https://en.wikipedia.org/wiki/Continued%20process%20verification | Continued process verification (CPV) is the collection and analysis of end-to-end production components and processes data to ensure product outputs are within predetermined quality limits. In 2011 the Food and Drug Administration published a report outlining best practices regarding business process validation in the pharmaceutical industry. Continued process verification is outlined in this report as the third stage in Process Validation.
Its central purpose is to ensure that processes are in a constant state of control, thus ensuring final product quality. Central to effective CPV is a method with which to identify unwanted process inconsistencies in order to execute corrective or preventive measures. Once quality standards are set in place they must be monitored with regular frequency to confirm those parameters are being met. Continued process verification not only helps protect consumers from production faults, but business also see benefits in implementing a CPV program. Should product outputs not match target standards it can be very costly to investigate the problem source without existing CPV data.
Vital components of continued process verification
An alert system to identify process malfunctions that lead to deviations from quality standards.
A framework for gathering and analyzing data of final product quality and process consistency. Analysis should include source materials consistency and manufacturing equipment condition; and data should be collected in a format that allows for long-term trend analysis as well as intra-production quality analysis.
Continued review of quality qualification standards and process reliability. Departures from any predetermined standards should be flagged for review by trained personnel and appropriate measures undertaken to restore end-to-end quality standards.
Data collection and analysis
Crucial in effective CPV implementation is an appropriate data collection procedure. Data must allow for statistical analytics and trend analysis of process consistency and capability. A correctly implemented procedure will minimize overreactions to individual production outlier events and guarantee genuine process inconsistency are detected. While production variability can sometimes be obvious and even casually identified the FDA recommends using statistical tools to quantitatively detect problems and identify root causes. Initially, continued process verification should be based on quality standards established in the design phase. After a period of time variations can be detected by identifying deviation from historical data using statistical tools. Furthermore, these same tools can also be used to identify opportunities to optimize processes that may pre-emptively increase quality reliability.
References
Further reading
BPOG, 2014, Continued Process Verification: An Industry Position Paper with Example Plan © 2014, BPOG - Biophorum Operations Group. Retrieved 26 August 2015.
Software testing
Formal methods
Software quality
Enterprise modelling
Quality management
Business process | Continued process verification | [
"Engineering"
] | 512 | [
"Systems engineering",
"Software testing",
"Enterprise modelling",
"Software engineering",
"Formal methods"
] |
44,287,480 | https://en.wikipedia.org/wiki/NGC%2072 | NGC 72 is a barred spiral galaxy estimated to be about 320 million light-years away in the constellation of Andromeda. It was discovered by R. J. Mitchell in 1855 and its magnitude is 13.5.
References
External links
0072
001204
Andromeda (constellation)
18551007
Spiral galaxies | NGC 72 | [
"Astronomy"
] | 66 | [
"Andromeda (constellation)",
"Constellations"
] |
44,287,490 | https://en.wikipedia.org/wiki/NGC%2073 | NGC 73 is an intermediate spiral galaxy estimated to be about 350 million light-years away in the constellation of Cetus. It was discovered by Lewis A. Swift from the USA in 1886 and its apparent magnitude is 13.7.
References
External links
0073
001211
Cetus
18861021
Discoveries by Lewis Swift
Intermediate spiral galaxies | NGC 73 | [
"Astronomy"
] | 69 | [
"Cetus",
"Constellations"
] |
44,287,506 | https://en.wikipedia.org/wiki/NGC%2075 | NGC 75 is a lenticular galaxy estimated to be about 260 million light-years away in the constellation of Pisces. It was discovered by Lewis A. Swift from the USA in 1886 and its magnitude is 13.2.
References
External links
0075
001255
Pisces (constellation)
18861022
Lenticular galaxies | NGC 75 | [
"Astronomy"
] | 68 | [
"Pisces (constellation)",
"Constellations"
] |
44,287,538 | https://en.wikipedia.org/wiki/NGC%2076 | NGC 76 is a lenticular galaxy estimated to be about 320 million light-years away in the constellation of Andromeda. It was discovered by Guillaume Bigourdan from France in 1884 and its magnitude is 13.1.
References
External links
0076
001267
Andromeda (constellation)
18840922
Lenticular galaxies | NGC 76 | [
"Astronomy"
] | 69 | [
"Andromeda (constellation)",
"Constellations"
] |
44,290,263 | https://en.wikipedia.org/wiki/Mutual%20shaping | Mutual shaping suggests that society and technology are not mutually exclusive to one another and, instead, influence and shape each other. This process is a combination of social determinism and technological determinism. The term mutual shaping was developed through science and technology studies (STS) in an attempt to explain the detailed process of technological design. Mutual shaping is argued to have a more comprehensive understanding of the development of new media because it considers technological and social change as directly affecting the other.
Comparison of TD and SD
Technological determinism (TD), coined by Thorstein Veblen, suggests that technology is the primary catalyst for change in society. Following this theory, the development and implementation of technology is beyond the control of society as it is pervasive in all elements of our lives. Once a technology has been created its influence on society is an inevitable, predetermined path. Technological deterministic view suggests that technology is the cause of societal change, which shapes humans and their environments. An example that supports technological determinism is the development of the printing press that accelerated the Protestant Reformation.
In contrast, social determinism (SD), popularized by social theorists Karl Marx and Emile Durkheim, purports that social structure is the driving factor towards change in society. Following this view, society is the governing force that determines social behaviour, and technology is created and adapted based on society's wants and needs. Social determinism has been observed as response to technological determinism and explains that it is social and environmental factors which determine how technology is used and progresses.
Both TD and SD are cause-and-effect theories suggesting that technology and society are mutually exclusive. The theory of mutual shaping suggests that technology design is a result of a synthesis of TD and SD. It sees technology and society working together to facilitate change. Society changes as a direct result of the implementation of technology that has been created based on society's wants and needs. They function collectively to shape one another.
Examples
Technology innovations have long been tied to social changes. The move to an industrial society from an agricultural society meant that people had to adjust their social interactions. Agricultural societies have a few, distant and long-term relationships with people, while industrial societies have more casual, short-term relationships.
Technological innovations also don't work in isolation from social change and vice versa. For example, while the telephone was initially invented as an extension of the telegraph, with a focus on business, the telephone quickly became a popular way for people to chat socially. Telephone companies then began to make innovations to enhance social interactions.
In social networks
Mutual shaping is exemplified through the integration of online social networking platforms into daily life. They are a communications technology designed to complement pre-existing methods of communication, such as the phone or in-person conversations, that have become more convenient and/or affordable than their predecessors. TD would argue that these communication technologies have directly influenced our networking capabilities due to their accessibility. Without them we would not be able to conduct business or maintain friendships over long distances. SD would argue that these platforms were created as a result of a need to facilitate communication over long distances. Mutual shaping supports both of these arguments, believing that the two cannot be separated. Social networking platforms display how technology and society are inextricably linked as they work together towards the advancement of one another, exemplifying the theory of mutual shaping.
The Negative Impact
The impact of mutual shaping has not always been positive. When the printing press was first introduced, many were worried about the information overload it might cause. Recently, Internet addiction, or problematic internet use (PIU), has become a widespread issue. PIU can cause lack of sleep due to internet usage as well as increasing the risk for certain physical ailments like eyestrain. Smartphones allow for endless amounts of information to be accessible in the pockets of its users. However, the social stigma around smartphone use has centered around how technology addiction can lead to increased stress and anxiety for the users.
Push-Pull-Thinking
Push-Pull-Thinking can be understood by the application of how new technology is created. When new demand for a product is the driving factor behind its creation then it is the "pulled" method, while when a new technology enters the market with new possibilities for application or innovation then it is the "push method."
Examples
According to Michael Haddad, it's easier to understand an example of Push-Pull-Thinking where technology is the driving factor as one from an engineering or research and development background. Sony's Walkman personal stereo cassette player has also been stated as an example of a technology push where there was no market need.
In cases of Push-Pull-Thinking, where demand is the driving factor, the needs or requirements of society or market its best to take a market research approach to innovation. Innovations regarding safety are often seen as pulled innovations with car airbags and new medical advancements are usually listed as examples.
References
Determinism
Science and technology studies
Philosophy of technology | Mutual shaping | [
"Technology"
] | 1,018 | [
"Philosophy of technology",
"Science and technology studies"
] |
44,290,296 | https://en.wikipedia.org/wiki/Toric%20stack | In algebraic geometry, a toric stack is a stacky generalization of a toric variety. More precisely, a toric stack is obtained by replacing in the construction of a toric variety a step of taking GIT quotients with that of taking quotient stacks. Consequently, a toric variety is a coarse approximation of a toric stack. A toric orbifold is an example of a toric stack.
See also
Stanley–Reisner ring
References
Algebraic geometry | Toric stack | [
"Mathematics"
] | 100 | [
"Fields of abstract algebra",
"Algebraic geometry"
] |
44,290,318 | https://en.wikipedia.org/wiki/Russula%20campinensis | Russula campinensis is a neotropical species in the genus Russula. This species is highly different from most other known Russula species in that it has very small (2–17 mm), pleurotoid fruitbodies that develop on tree trunks in up to 2 m elevation from the forest floor. It was described as Lactarius campinensis from Brazil (Amazonas) by Rolf Singer. T.W. Henkel, M.C. Aime and S.L. Miller later found this species in tropical rainforest of the Pakaraima Mountains, Guyana, and showed with molecular phylogenetic methods that it belongs to Russula. Although forming fruitbodies on wood, R. campinensis is a root-symbiotic ectomycorrhizal species and has been observed in Guyana associated with Dicymbe altsonii and D. jenzenii trees in the legume subfamily Caesalpinioideae.
See also
List of Russula species
References
External links
Tropical Fungi – Russula campinensis
campinensis
Fungi described in 1985
Taxa named by Rolf Singer
Fungus species | Russula campinensis | [
"Biology"
] | 229 | [
"Fungi",
"Fungus species"
] |
44,290,443 | https://en.wikipedia.org/wiki/List%20of%20edible%20plants%20and%20mushrooms%20of%20southeast%20Alaska | Southeast Alaska has an unusual climate that allows a large number of edible plant and edible mushroom species to grow. The area consists primarily of the Tongass National Forest, which is a temperate rainforest. This rainforest has plenty of precipitation and the temperature remains relatively constant, therefore many plant and fungi species flourish there. On a geological time scale, fairly recently during the Little Ice Age, glaciers were abundant in southeast Alaska. The ice age's last maximum ended about 10,000 years ago. Once the glaciers retreated, they left behind nutrient-rich sediments. These nutrients in the soil enriched the ecosystem of the area.
Tlingit use
Historically the Tlingit people of the Pacific Northwest foraged off of the land. The Tlingit cuisine included everything from whales to deer, and from clams to plants. Often the Tlingit people included in their diet many edible items from the surrounding native vegetation along with what ever seafood and wild game they were able to find. Hunting and fishing expeditions were not always successful, in which case, meals were made using the local berries, fungus, and seaweed. Because winters were long and cold in the Pacific Northwest, the Tlingit people used preserving methods in order to be able to use the gathered vegetation all winter long. Many of the edible plants that are consumed today in southeast Alaska are eaten because of the knowledge passed down from many generations of Tlingit.
Berries
Fungi
The temperate rainforest of the Tongass National Forest often produces a great amount of mushrooms in the summer and fall months. Fungi can be used for dyeing natural fibers and as a food source. In the ecosystem, Fungi cycle nutrients, aggregate soil, retain water, and are a source of food for many animals. There are many kinds of fungi, including Chanterelles, Boletes, Morels, and Puffballs.
Limits on harvesting
Generally speaking individuals are permitted to harvest mushrooms in the Tongass National Forest without a special license. However, it is expected that harvesters help protect the natural resources from damage. For commercial harvest, a permit is required. Harvesters must check with a local forest ranger to make sure all harvesting is legal.
Many species of mushrooms and berries can be poisonous, but look similar to the edible species. Harvesting the entire mushroom allows for easier identification as does taking note of the surroundings where the fungus was found. All harvested mushrooms need to be cooked, not eaten raw.
References
Alaska,southeast
Flora of Alaska
Edible,Alaska,southeast
Pacific temperate rainforests
Tlingit
Alaska-related lists | List of edible plants and mushrooms of southeast Alaska | [
"Biology"
] | 508 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
44,290,512 | https://en.wikipedia.org/wiki/Multifurca%20furcata | Multifurca furcata is a rare mushroom-forming fungus in the genus Multifurca. It was originally described as a Lactarius species in 1918 and was moved to the new genus Multifurca in 2008. With the genus Lactarius it shares the exudation of milk-like latex; however, it is microscopically and molecularly distinct. It has been found very infrequently, with currently known localities in the United States, Mexico, Costa Rica, and China.
References
External links
Russulales News / Multifurca furcata
Russulales
Fungi described in 1918
Fungus species | Multifurca furcata | [
"Biology"
] | 128 | [
"Fungi",
"Fungus species"
] |
44,291,025 | https://en.wikipedia.org/wiki/Beach%20advisory | A beach advisory is a warning given by a local government to avoid swimming in a body of water. Beach advisories do not automatically close bodies of water to swimmers but instead function as a warning to swimmers against swimming at a particular site.
Beach advisories are issued after unsafe levels of Enterococcus are detected at sample sites along a body of water, often resulting from high levels of fecal matter in the water. One source of waste pollution and subsequent increase in enteroccus concentration may come from migrating birds. Enterococcus bacteria is not harmful by itself, but it indicates harmful bacteria is in the water. These types of bacteria can cause gastrointestinal illnesses, resulting in vomiting and diarrhea. They may also cause upper respiratory illness as well as skin infections at an open wound.
Beach advisories are also issued after chemical spills. Beach advisories are often issued after rain advisories because high amounts of rain can cause contaminated streamflow from flooding to enter a body of water and contaminate the swimming area.
Reasons for Beach Advisories
Enterococcus
Enterococcus is a large genus of lactic acid phylum Firmicutes Fecal enterococci inhabit gastrointestinal tract of animals. Therefore, having abnormally high indicators of fecal enterococcus in bodies of water correlates directly to fecal contamination (Domingo et al., 2003). Domingo also suggests that using the TaqMan-based approach can detect Enterococcus in environmental waters. This method may be performed in the span of a few hours, making it an efficient system that local governments may rely on, while issuing a beach advisory. Another method to detect large numbers of enterococcus in water is an agar-based growth media incubated under standard aerobic conditions. While conducting various tests involving selective as well as non-selective methods, cultures of enterococcus are isolated in brass and earthen vessels for up to 48 hours (Chhibber et al., 2007). Enterococcus may cause an array of illnesses, varying from cellulitis, prostatitis, diverticulitis, urinary tract infections (UTI), endocarditis as well intra-abdominal infections (Bush, 2013).
Cellulitis
The Mayo Clinic defines cellulitis as a common but potentially serious bacterial skin infection (2015). Symptoms of cellulitis include skin swelling, tenderness, redness and skin feeling hot. Cellulitis does not usually spread from person to person, but may enter the body by cracks or breaks in the skin. Cellulitis usually appears on the lower parts of the legs but may spread anywhere on the body. Cellulitis begins by affecting merely the surface of the skin, but may migrate to the tissues, affecting lymph nodes and eventually the bloodstream. If left untreated, the spreading infection may become life-threatening. It is crucial that one seeks medical treatment if the previously mentioned symptoms occur.
Prostatitis
Enterococcus may also cause prostatitis. Prostatitis is the swelling and inflammation of the prostate gland that is located below men's bladders. Prostatitis can cause painful or difficult urination. Other symptoms may also include pain in the groin, pelvic area and flu-like symptoms. It is important to seek medical attention immediately once experiencing one or more of the symptoms. Prostatitis may be treated by taking antibiotics, but left untreated may cause medical complications concerning the prostate.
Diverticulitis
Diverticula are small pouches that form in the lining of the digestive system, generally in the lower part of the large intestine. Although there are a small number of implications, there may be swelling of one or more of the pouches. This may lead to infections and can cause extreme abdominal pain, fever, nausea and irregular bowel movements (Mayo Clinic, 2015). Simply resting and taking antibiotics can treat diverticulitis, although serious cases may require surgery.
Escherichia coli (E. coli)
Escherichia coli, or E. coli is a bacterium that can be found in many warm-blooded animals, which includes, humans, livestock, wildlife and birds (government of Manitoba). Escherichia coli does not usually cause illness by itself, but when it contaminates large numbers, the level of illness raises. E. coli is expelled into the environment via fecal matter. According to the Public Health Agency of Canada (2015), drinking contaminated water or drinking contaminated food may contract E. coli infections. E. coli may also be spread from one person to another. Symptoms may include nausea, diarrhea, vomiting and severe stomach cramps. Symptoms may appear anywhere from 3 to 10 days after ingestion of the bacteria.
There has been a study in Manitoba concerning the elevated E. coli numbers in Lake Winnipeg. The Interim Report of the Manitoba Water Stewardship, 2009 explains reasons for elevated Escherichia coli in Lake Winnipeg Beaches (Williamson et al., 2009). The Interim Report shows the correlation of high counts of Escherichia coli in the Lake with large discharge of sewage from the City of Winnipeg, run-offs from livestock operations into Lake Winnipeg. The lake had issued countless amounts of beach advisories to the public once it was noticed that irregular amounts of E. coli was found in the water. Studies had proved that the high number of E. coli in bathing water was partially due to wind-induced water level changes and that the majority of it originated from animal sources as opposed to human activity.
Urinary Tract Infection (UTI)
A Urinary Tract Infection is an infection that involves any part of the urinary system, being the kidneys, urethra, bladder, or ureters. Although women are more susceptible to getting UTI's, men may also develop them. The infection causes pain while urinating, the urge to urinate often, and pelvic pain. UTIs may be caused by Escherichia coli, which as mentioned above, may be found in bodies of water at the time of beach advisories. Generally, UTIs can be treated with antibiotics that are prescribed by a doctor.
Illnesses
Swimmer's itch
Swimmer's itch is a skin condition that occurs to people who partake in open-water activities. Swimmer's itch may happen in any body of water in the world and is not exclusive to one specific region. The condition involves the cercarial dermatitis to penetrate the skin, while dying in the epidermis, causing the itching sensation (Blankespoor et al., 2004). Beach advisories may be put in place if there is an outbreak of swimmer's itch, but its importance in the public health sector is still unknown. Outbreaks and reoccurring beach advisories may influence vacationers to travel elsewhere although its severity is still in question.
Notes
References
Bush, M. Larry, & Perez, T. Maria. (2013). Enterococcus Infections. Merck Manual, Professional Version. Retrieved from http://www.merckmanuals.com/professional/infectious-diseases/gram-positive-cocci/enterococcal-infections
Mayo Clinic Staff. (2015, February 11). Diseases and Conditions. [Website]. Retrieved from http://www.mayoclinic.org/diseases-conditions/cellulitis/basics/definition/con-20023471
Public Health Agency of Canada. (2015). E. Coli. Retrieved from http://www.phac-aspc.gc.ca/fs-sa/fs-fi/ecoli-eng.php
Santo, D. J. W., Siefring, S. C., & Haugland, R. A. (January 1, 2003). Real-time PCR method to detect Enterococcus faecalis in water. Biotechnology Letters, 25, 3, 261–5.
S J Corbett, G L Rubin, G K Curry, and D G Kleinbaum. The health effects of swimming at Sydney beaches. The Sydney Beach Users Study Advisory Group. American Journal of Public Health, December 1993: Vol. 83, No. 12, pp. 1701-1706.
Tandon, P., Chhibber, S., & Reed, R. H. (January 1, 2007). Survival & detection of the faecal indicator bacterium Enterococcus faecalis in water stored in traditional vessels. The Indian Journal of Medical Research, 125, 4, 557–566.
Verbrugge, L. M., Rainey, J. J., Reimink, R. L., & Blankespoor, H. D. (January 1, 2004). Prospective study of swimmer's itch incidence and severity. The Journal of Parasitology, 90, 4, 697–704.
Williamson, D. A., & Manitoba. (2004). Principal factors affecting Escherichia coli at Lake Winnipeg beaches, Manitoba, Canada: Interim report. Winnipeg: Manitoba Water Stewardship.
Advisory, beach
Safety
Natural hazards
Warning systems | Beach advisory | [
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44,291,266 | https://en.wikipedia.org/wiki/Calcium%20imaging | Calcium imaging is a microscopy technique to optically measure the calcium (Ca2+) status of an isolated cell, tissue or medium. Calcium imaging takes advantage of calcium indicators, fluorescent molecules that respond to the binding of Ca2+ ions by fluorescence properties. Two main classes of calcium indicators exist: chemical indicators and genetically encoded calcium indicators (GECI). This technique has allowed studies of calcium signalling in a wide variety of cell types. In neurons, action potential generation is always accompanied by rapid influx of Ca2+ ions. Thus, calcium imaging can be used to monitor the electrical activity in hundreds of neurons in cell culture or in living animals, which has made it possible to observe the activity of neuronal circuits during ongoing behavior.
Chemical indicators
Chemical indicators are small molecules that can chelate calcium ions. All these molecules are based on an EGTA homologue called BAPTA, with high selectivity for calcium (Ca2+) ions versus magnesium (Mg2+) ions.
This group of indicators includes fura-2, indo-1, fluo-3, fluo-4, Calcium Green-1.
These dyes are often used with the chelator carboxyl groups masked as acetoxymethyl esters, in order to render the molecule lipophilic and to allow easy entrance into the cell. Once this form of the indicator is in the cell, cellular esterases will free the carboxyl groups and the indicator will be able to bind calcium. The free acid form of the dyes (i.e. without the acetoxymethyl ester modification) can also be directly injected into cells via a microelectrode or micropipette which removes uncertainties as to the cellular compartment holding the dye (the acetoxymethyl ester can also enter the endoplasmic reticulum and mitochondria). Binding of a Ca2+ ion to a fluorescent indicator molecule leads to either an increase in quantum yield of fluorescence or emission/excitation wavelength shift. Individual chemical Ca2+ fluorescent indicators are utilized for cytosolic calcium measurements in a wide variety of cellular preparations. The first real time (video rate) Ca2+ imaging was carried out in 1986 in cardiac cells using intensified video cameras. Later development of the technique using laser scanning confocal microscopes revealed sub-cellular Ca2+ signals in the form of Ca2+ sparks and Ca2+ blips. Relative responses from a combination of chemical Ca2+ fluorescent indicators were also used to quantify calcium transients in intracellular organelles such as mitochondria.
Calcium imaging, also referred to as calcium mapping, is also used to perform research on myocardial tissue. Calcium mapping is a ubiquitous technique used on whole, isolated hearts such as mouse, rat, and rabbit species.
Genetically encoded calcium indicators
Genetically encoded calcium indicators (GECIs) are powerful tools useful for in vivo imaging of cellular, developmental, and physiological processes. GECIs do not need to be acutely loaded into cells; instead the genes encoding for these proteins can be introduced into individual cells or cell lines by various transfection methods. It is also possible to create transgenic animals expressing the indicator in all cells or selectively in certain cellular subtypes. GECIs are used to study neurons, T-cells, cardiomyocytes, and other cell types. Some GECIs report calcium by direct emission of photons (luminescence), but most rely on fluorescent proteins as reporters, including the green fluorescent protein GFP and its variants (eGFP, YFP, CFP).
Of the fluorescent reporters, calcium indicator systems can be classified into single fluorescent protein (FP) systems, and paired fluorescent protein systems. Camgaroos were one of the first developed variants involving a single protein system. Camgaroos take advantage of calmodulin (CaM), a calcium binding protein. In these structures, CaM is inserted in the middle of yellow fluorescent protein (YFP) at Y145. Previous mutagenesis studies revealed that mutations at this position conferred pH stability while maintaining fluorescent properties, making Y145 an insertion point of interest. Additionally, the N and C termini of YFP are linked by a peptide linker (GGTGGS). When CaM binds to Ca2+, the effective pKa is lowered, allowing for chromophore deprotonation. This results in increased fluorescence upon calcium binding in an intensiometric fashion. Such detection is in contrast with ratiometric systems, in which there is a change in the absorbance/emission spectra as a result of Ca2+ binding. A later developed single-FP system, dubbed G-CaMP, also invokes circularly permuted GFP. One of the termini is fused with CaM, and the other termini is fused with M13 (the calmodulin binding domain of myosin light kinase) The protein is designed such that the termini are close in space, allowing for Ca2+ binding to cause conformational changes and chromophore modulation, allowing for increased fluorescence. G-CaMP and its refined variants have nanomolar binding affinities. A final single protein variant is the CatchER, which is generally considered to be a lower affinity indicator. Its calcium binding pocket is quite negative; binding of the cation helps to shield the large concentration of negative charge and allows for recovered fluorescence.
In contrast to these systems are paired fluorescent protein systems, which include the prototypical Cameleons. Cameleons consist of two different fluorescent proteins, CaM, M13, and a glycylglycine linker. In the absence of Ca2+, only the donor blue-shifted fluorescent protein will be fluorescent. However, a conformational change caused by calcium binding repositions the red-shifted fluorescent protein, allowing for FRET (Förster resonance energy transfer) to take place. Cameleon indicators produce a ratiometric signal (i.e. the measured FRET efficiency depends on the calcium concentration). Original variants of cameleons were originally more sensitive to Ca2+ and were acid quenched. Such shortcomings were abrogated by Q69K and V68L mutations. Both of these residues were close to the buried anionic chromophore and these mutations probably hinder protonation, conferring greater pH resistance.
Of growing importance in calcium detection are near-IR (NIR) GECIs, which may open up avenues for multiplexing different indicator systems and allowing deeper tissue penetration. NIR GECIs rely on biliverdin-binding fluorescent proteins, which are largely derived from bacterial phytochromes. NIR systems are similar to inverse pericams in that both experience a decrease in fluorescence upon Ca2+ binding. RCaMPs and RGECOs are functional at 700+ nm, but are quite dim. A Cameleon analog involving NIR FRET has been successfully constructed as well.
A special class of GECIs are designed to form a permanent fluorescent tag in active neurons. They are based on the photoswitchable protein Eos which turns from green to red through photocatalyzed (with violet light) backbone cleavage. Combined with the CaM, violet light photoconverts only neurons that have elevated calcium levels. SynTagMA is a synapse-targeted version of CaMPARI2.
While fluorescent systems are widely used, bioluminescent Ca2+ reporters may also hold potential because of their ability to abrogate autofluorescence, photobleaching [no excitation wavelength is needed], biological degradation and toxicity, in addition to higher signal-to-noise ratios. Such systems may rely on aequorin and the luciferin coelenterazine. Ca2+ binding causes a conformational change that facilitates coelenterazine oxidation. The resultant photoproduct emits blue light as it returns to the ground state. Colocalization of aequorin with GFP facilitates BRET/CRET (Bioluminescence or Chemiluminescence Resonance Energy Transfer), resulting in a 19 - 65 brightness increase. Such structures can be used to probe millimolar to nanomolar calcium concentrations. A similar system invokes obelin and its luciferin coelenteramide, which may possess faster calcium response time and Mg2+ insensitivity than its aqueorin counterpart. Such systems can also leverage the self-assembly of luciferase components. In a system dubbed “nano-lantern,” the luciferase RLuc8 is split and placed on different ends of CaM. Calcium binding brings the RLuc8 components in close proximity, reforming luciferase, and allowing it to transfer to an acceptor fluorescent protein.
To minimize damage to the visualized cells, two-photon microscopy is often invoked to detect the fluorescence from the reporters. The use of near-IR wavelengths and minimization of axial spread of the point function allows for nanometer resolution and deep penetration into the tissue. The dynamic range is often determined from such measurements. For non-ratiometric indicators (typically single protein indicators), it is the ratio of the fluorescence intensities obtained under Ca2+ saturated and depleted conditions, respectively. However, for ratiometric indicators, the dynamic range is the ratio of the maximum FRET efficiency ratio (calcium saturated) to the minimum FRET efficiency ratio (calcium depleted). Yet another common quantity used to measure signals produced by calcium concentration fluxes is the signal-to-baseline ratio (SBR), which is simply the ratio of the change in fluorescence (F - F0) over the baseline fluorescence. This can be related to the SNR (signal to noise ratio) by multiplying the SBR by the square root of the number of counted photons.
A special class of genetically encoded calcium indicators are designed to form a permanent fluorescent tag in active neurons. They are based on the photoswitchable protein mEos which turns from green to red when illuminated with violet light. Combined with the calcium sensor calmodulin, violet light photoconverts only neurons that have elevated calcium levels. SynTagMA is a synapse-targeted version of CaMPARI2.
Usage
Regardless of the type of indicator used, the imaging procedure is generally very similar. Cells loaded with an indicator, or expressing it in the case of a GECI, can be viewed using a fluorescence microscope and captured by a Scientific CMOS (sCMOS) camera or CCD camera. Confocal and two-photon microscopes provide optical sectioning ability so that calcium signals can be resolved in microdomains such as dendritic spines or synaptic boutons, even in thick samples such as mammalian brains. Images are analyzed by measuring fluorescence intensity changes for a single wavelength or two wavelengths expressed as a ratio (ratiometric indicators). If necessary, the derived fluorescence intensities and ratios may be plotted against calibrated values for known Ca2+ levels to measure absolute Ca2+ concentrations. Light field microscopy methods extend functional readout of neural activity capabilities in 3D volumes.
Methods such as fiber photometry, miniscopes and two-photon microscopy offer calcium imaging in freely behaving and head-fixed animal models.
References
Further reading
Cell imaging | Calcium imaging | [
"Chemistry",
"Biology"
] | 2,323 | [
"Cell imaging",
"Microscopy"
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44,291,624 | https://en.wikipedia.org/wiki/Billings%20Refinery%20%28Par%20Pacific%29 | The Billings Refinery is an American oil refinery located in Billings, Montana, owned and operated by Par Pacific Holdings which took over operations from ExxonMobil on June 1, 2023. ExxonMobil previously announced on October 20, 2022, that it would sell the refinery to Par Pacific with the sale expected to complete in the second quarter of 2023.
The complex is capable of refining of crude oil per day.
See also
List of oil refineries
References
External links
Energy infrastructure in Montana
Buildings and structures in Billings, Montana
Oil refineries in the United States | Billings Refinery (Par Pacific) | [
"Chemistry"
] | 117 | [
"Petroleum",
"Petroleum stubs"
] |
44,291,735 | https://en.wikipedia.org/wiki/Laurel%20Refinery | The Laurel Refinery is a petroleum refinery located in Laurel, Montana. The refinery is currently owned and operated by CHS Inc.
References
External links
CHS website
Energy infrastructure in Montana
Buildings and structures in Yellowstone County, Montana
Oil refineries in the United States | Laurel Refinery | [
"Chemistry"
] | 53 | [
"Petroleum",
"Petroleum stubs"
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44,292,528 | https://en.wikipedia.org/wiki/Same-sex%20intimacy | Same-sex intimacy is a relationship between two friends of the same sex that has many components of a sexually intimate relationship (e.g. self-disclosures, emotional expressiveness, unconditional support, physical contact and trust), but not necessarily sexual intimacy or sexual contact. The term can apply to the exploration of sexuality outside the home, as well as to the physical activities shared between two friends.
See also
Cross-sex friendship
References
Friendship | Same-sex intimacy | [
"Biology"
] | 92 | [
"Behavior",
"Sexuality stubs",
"Sexuality"
] |
44,293,086 | https://en.wikipedia.org/wiki/Galvanic%20corrosion | Galvanic corrosion (also called bimetallic corrosion or dissimilar metal corrosion) is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte. A similar galvanic reaction is exploited in primary cells to generate a useful electrical voltage to power portable devices. This phenomenon is named after Italian physician Luigi Galvani (1737–1798).
A similar type of corrosion caused by the presence of an external electric current is called electrolytic corrosion.
Overview
Dissimilar metals and alloys have different electrode potentials, and when two or more come into contact in an electrolyte, one metal (that is more reactive) acts as anode and the other (that is less reactive) as cathode. The electropotential difference between the reactions at the two electrodes is the driving force for an accelerated attack on the anode metal, which dissolves into the electrolyte. This leads to the metal at the anode corroding more quickly than it otherwise would and corrosion at the cathode being inhibited. The presence of an electrolyte and an electrical conducting path between the metals is essential for galvanic corrosion to occur. The electrolyte provides a means for ion migration whereby ions move to prevent charge build-up that would otherwise stop the reaction. If the electrolyte contains only metal ions that are not easily reduced (such as Na+, Ca2+, K+, Mg2+, or Zn2+), the cathode reaction is the reduction of dissolved H+ to H2 or O2 to OH−.
In some cases, this type of reaction is intentionally encouraged. For example, low-cost household batteries typically contain carbon-zinc cells. As part of a closed circuit (the electron pathway), the zinc within the cell will corrode preferentially (the ion pathway) as an essential part of the battery producing electricity. Another example is the cathodic protection of buried or submerged structures as well as hot water storage tanks. In this case, sacrificial anodes work as part of a galvanic couple, promoting corrosion of the anode, while protecting the cathode metal.
In other cases, such as mixed metals in piping (for example, copper, cast iron and other cast metals), galvanic corrosion will contribute to accelerated corrosion of parts of the system. Corrosion inhibitors such as sodium nitrite or sodium molybdate can be injected into these systems to reduce the galvanic potential. However, the application of these corrosion inhibitors must be monitored closely. If the application of corrosion inhibitors increases the conductivity of the water within the system, the galvanic corrosion potential can be greatly increased.
Acidity or alkalinity (pH) is also a major consideration with regard to closed loop bimetallic circulating systems. Should the pH and corrosion inhibition doses be incorrect, galvanic corrosion will be accelerated. In most HVAC systems, the use of sacrificial anodes and cathodes is not an option, as they would need to be applied within the plumbing of the system and, over time, would corrode and release particles that could cause potential mechanical damage to circulating pumps, heat exchangers, etc.
Examples
A common example of galvanic corrosion occurs in galvanized iron, a sheet of iron or steel covered with a zinc coating. Even when the protective zinc coating is broken, the underlying steel is not attacked. Instead, the zinc is corroded because it is less "noble". Only after it has been consumed can rusting of the base metal occur. By contrast, with a conventional tin can, the opposite of a protective effect occurs: because the tin is more noble than the underlying steel, when the tin coating is broken, the steel beneath is immediately attacked preferentially.
Statue of Liberty
A spectacular example of galvanic corrosion occurred in the Statue of Liberty when regular maintenance checks in the 1980s revealed that corrosion had taken place between the outer copper skin and the wrought iron support structure. Although the problem had been anticipated when the structure was built by Gustave Eiffel to Frédéric Bartholdi's design in the 1880s, the insulation layer of shellac between the two metals had failed over time and resulted in rusting of the iron supports. An extensive renovation was carried out with replacement of the original insulation with PTFE. The structure was far from unsafe owing to the large number of unaffected connections, but it was regarded as a precautionary measure to preserve a national symbol of the United States.
Royal Navy and HMS Alarm
In 1681, Samuel Pepys (then serving as Admiralty Secretary) agreed to the removal of lead sheathing from English Royal Navy vessels to prevent the mysterious disintegration of their rudder-irons and bolt-heads, though he confessed himself baffled as to the reason the lead caused the corrosion.
The problem recurred when vessels were sheathed in copper to reduce marine weed accumulation and protect against shipworm. In an experiment, the Royal Navy in 1761 had tried fitting the hull of the frigate HMS Alarm with 12-ounce copper plating. Upon her return from a voyage to the West Indies, it was found that although the copper remained in fine condition and had indeed deterred shipworm, it had also become detached from the wooden hull in many places because the iron nails used during its installation "were found dissolved into a kind of rusty Paste". To the surprise of the inspection teams, however, some of the iron nails were virtually undamaged. Closer inspection revealed that water-resistant brown paper trapped under the nail head had inadvertently protected some of the nails: "Where this covering was perfect, the Iron was preserved from Injury". The copper sheathing had been delivered to the dockyard wrapped in the paper which was not always removed before the sheets were nailed to the hull. The conclusion therefore reported to the Admiralty in 1763 was that iron should not be allowed direct contact with copper in sea water.
US Navy littoral combat ship Independence
Serious galvanic corrosion has been reported on the latest US Navy attack littoral combat vessel the USS Independence caused by steel water jet propulsion systems attached to an aluminium hull. Without electrical isolation between the steel and aluminium, the aluminium hull acts as an anode to the stainless steel, resulting in aggressive galvanic corrosion.
Corroding lighting fixtures
The unexpected fall in 2011 of a heavy light fixture from the ceiling of the Big Dig vehicular tunnel in Boston revealed that corrosion had weakened its support. Improper use of aluminium in contact with stainless steel had caused rapid corrosion in the presence of salt water. The electrochemical potential difference between stainless steel and aluminium is in the range of 0.5 to 1.0V, depending on the exact alloys involved, and can cause considerable corrosion within months under unfavorable conditions. Thousands of failing lights would have to be replaced, at an estimated cost of $54 million.
Lasagna cell
A "lasagna cell" is accidentally produced when salty moist food such as lasagna is stored in a steel baking pan and is covered with aluminium foil. After a few hours the foil develops small holes where it touches the lasagna, and the food surface becomes covered with small spots composed of corroded aluminium. In this example, the salty food (lasagna) is the electrolyte, the aluminium foil is the anode, and the steel pan is the cathode. If the aluminium foil touches the electrolyte only in small areas, the galvanic corrosion is concentrated, and corrosion can occur fairly rapidly. If the aluminium foil was not used with a dissimilar metal container, the reaction was probably a chemical one. It is possible for heavy concentrations of salt, vinegar or some other acidic compounds to cause the foil to disintegrate. The product of either of these reactions is an aluminium salt. It does not harm the food, but any deposit may impart an undesired flavor and color.
Electrolytic cleaning
The common technique of cleaning silverware by immersion of the silver or sterling silver (or even just silver plated objects) and a piece of aluminium (foil is preferred because of its much greater surface area than that of ingots, although if the foil has a "non-stick" face, this must be removed with steel wool first) in a hot electrolytic bath (usually composed of water and sodium bicarbonate, i.e., household baking soda) is an example of galvanic corrosion. Silver darkens and corrodes in the presence of airborne sulfur molecules, and the copper in sterling silver corrodes under a variety of conditions. These layers of corrosion can be largely removed through the electrochemical reduction of silver sulfide molecules: the presence of aluminium (which is less noble than either silver or copper) in the bath of sodium bicarbonate strips the sulfur atoms off the silver sulfide and transfers them onto and thereby corrodes the piece of aluminium foil (a much more reactive metal), leaving elemental silver behind. No silver is lost in the process.
Prevention
There are several ways of reducing and preventing this form of corrosion:
Electrically insulate the two metals from each other. If they are not in electrical contact, no galvanic coupling will occur. This can be achieved by using non-conductive materials between metals of different electropotential. Piping can be isolated with a spool of pipe made of plastic materials, or made of metal material internally coated or lined. It is important that the spool be a sufficient length to be effective. For reasons of safety, this should not be attempted where an electrical earthing system uses the pipework for its ground or has equipotential bonding.
Metal boats connected to a shore line electrical power feed will normally have to have the hull connected to earth for safety reasons. However the end of that earth connection is likely to be a copper rod buried within the marina, resulting in a steel-copper "battery" of about 0.5 V. Additionally, the hull of each boat is connected to the hull of all other boats, resulting in further "batteries" between propellers (which may be made of bronze) and steel hulls, which may cause corrosion of the expensive propellers. For such cases, the use of a galvanic isolator is essential, typically two semiconductor diodes in series, in parallel with two diodes conducting in the opposite direction (antiparallel). This device is inserted in the protective earth connection between the hull and the shoreline protective conductor. This prevents any current in the protective conductor while the applied voltage is less than 1.4 V (i.e. 0.7 V per diode), but allows a full current in the case of an electrical fault. There will still be a very minor leakage of current through the diodes, which may result in slightly faster corrosion than normal.
Ensure there is no contact with an electrolyte. This can be done by using water-repellent compounds such as greases, or by coating the metals with an impermeable protective layer, such as a suitable paint, varnish, or plastic. If it is not possible to coat both, the coating should be applied to the more noble, the material with higher potential. This is advisable because if the coating is applied only on the more active material, in case of damage to the coating there will be a large cathode area and a very small anode area, and for the exposed anodic area the corrosion rate will be correspondingly high.
Using antioxidant paste is beneficial for preventing corrosion between copper and aluminium electrical connections. The paste consists of a lower nobility metal than aluminium or copper.
Choose metals that have similar electropotentials. The more closely matched the individual potentials, the smaller the potential difference and hence the smaller the galvanic current. Using the same metal for all construction is the easiest way of matching potentials.
Electroplating or other plating can also help. This tends to use more noble metals that resist corrosion better. Chrome, nickel, silver and gold can all be used. Galvanizing with zinc protects the steel base metal by sacrificial anodic action.
Cathodic protection uses one or more sacrificial anodes made of a metal which is more active than the protected metal. Alloys of metals commonly used for sacrificial anodes include zinc, magnesium, and aluminium. This approach is commonplace in water heaters and many buried or immersed metallic structures.
Cathodic protection can also be applied by connecting a direct current (DC) electrical power supply to oppose the corrosive galvanic current. (See .)
Galvanic series
All metals can be classified into a galvanic series representing the electrical potential they develop in a given electrolyte against a standard reference electrode. The relative position of two metals on such a series gives a good indication of which metal is more likely to corrode more quickly. However, other factors such as water aeration and flow rate can influence the rate of the process markedly.
Anodic index
The compatibility of two different metals may be predicted by consideration of their anodic index. This parameter is a measure of the electrochemical voltage that will be developed between the metal and gold. To find the relative voltage of a pair of metals it is only required to subtract their anodic indices.
To reduce galvanic corrosion for metals stored in normal environments such as storage in warehouses or non-temperature and humidity controlled environments, there should not be more than 0.25V difference in the anodic index of the two metals in contact. For controlled environments in which temperature and humidity are controlled, 0.50V can be tolerated. For harsh environments such as outdoors, high humidity, and salty environments, there should be not more than 0.15V difference in the anodic index. For example: gold and silver have a difference of 0.15V, therefore the two metals will not experience significant corrosion even in a harsh environment.
When design considerations require that dissimilar metals come in contact, the difference in anodic index is often managed by finishes and plating. The finishing and plating selected allow the dissimilar materials to be in contact, while protecting the more base materials from corrosion by the more noble. It will always be the metal with the most negative anodic index which will ultimately suffer from corrosion when galvanic incompatibility is in play. This is why sterling silver and stainless steel tableware should never be placed together in a dishwasher at the same time, as the steel items will likely experience corrosion by the end of the cycle (soap and water having served as the chemical electrolyte, and heat having accelerated the process).
Electrolytic corrosion
The term "electrolytic corrosion" is most frequently used to indicate corrosion caused by electric current applied to the metal from external sources. The mechanism of this corrosion is essentially the same as for the galvanic corrosion.
See also
Corrosion
Galvanic anode
Galvanic isolation in electrical/electronic circuits
Galvanic series
Galvanization
References
Sources
External links
Corrosion | Galvanic corrosion | [
"Chemistry",
"Materials_science"
] | 3,121 | [
"Metallurgy",
"Electrochemistry",
"Materials degradation",
"Corrosion"
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44,293,221 | https://en.wikipedia.org/wiki/Auston%20switch | An Auston switch (also known as a photoconductive switch) is an optically gated antenna that is commonly used in the generation and detection of pulsed terahertz radiation. It is named after the physicist David H. Auston who first developed the technology at Bell Labs in the 1960s.
Working
An Auston switch consists of a transmission line antenna with a gap that is bridged by a semiconductor. For terahertz generation, a DC bias voltage is applied across the antenna. When light from a pulsed laser with femtosecond pulses is focused on the gap, it excites charge carriers into the semiconductor's conduction band, which are subsequently accelerated by the bias voltage. The induced acceleration from the photocurrent causes the charge carriers to radiate in terahertz frequencies, generating a pulse lasting several picoseconds.
For use as a terahertz detector, the switch consists of the same geometry but without the applied bias voltage. Instead, the incident terahertz pulse itself provides the bias field for the charge carriers during the interval when the switch is activated by the (much shorter) laser pulse. The induced photocurrent can then be amplified and measured. To map the entire span of the terahertz pulse, the time delay between the femtosecond pulses at generation and detection can be varied.
References
Terahertz technology
Optical devices
Optoelectronics | Auston switch | [
"Physics",
"Materials_science",
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"Terahertz technology"
] |
44,293,494 | https://en.wikipedia.org/wiki/Gum%2015 | Gum 15 is a nebula from the Gum catalog, located in the constellation of Vela, about 3,000 light-years from Earth. It is shaped by aggressive winds flowing from the stars within and around it. The bright star in the center of the nebula is HD 74804, a double star.
References
H II regions
Vela (constellation) | Gum 15 | [
"Astronomy"
] | 73 | [
"Nebula stubs",
"Vela (constellation)",
"Astronomy stubs",
"Constellations"
] |
44,294,824 | https://en.wikipedia.org/wiki/Proterra%20%28earthen%20architecture%20project%29 | Proterra is an Ibero American organization promoting earthen architecture. It was initially founded as a four-year project of CYTED in 2001, but continued to become a UNESCO WHEAP partner in 2012.
References
Architecture organizations
Organizations established in 2001
UNESCO | Proterra (earthen architecture project) | [
"Engineering"
] | 53 | [
"Architecture organizations",
"Architecture"
] |
44,294,882 | https://en.wikipedia.org/wiki/Joshua%20Dobbs | Robert Joshua Dobbs (born January 26, 1995) is an American professional football quarterback for the San Francisco 49ers of the National Football League (NFL). He played college football for the Tennessee Volunteers, and was selected by the Pittsburgh Steelers in the fourth round of the 2017 NFL draft. Dobbs has been a member of eight NFL teams during his career, including as the starter for the Tennessee Titans, Arizona Cardinals, and Minnesota Vikings.
Early life
Dobbs was born and raised in Alpharetta, Georgia, the son of Stephanie and Robert Dobbs. His mother retired from United Parcel Service (UPS) as a region manager in corporate human resources, and his father retired as a senior vice president for Wells Fargo. Dobbs has alopecia areata, an autoimmune disease causing hair loss, which began when he was transitioning from elementary to junior high school.
Dobbs started playing football when he was five years old. He attended Wesleyan School and then Alpharetta High School. As a senior with the Alpharetta Raiders football team, he threw for 3,625 yards with 29 touchdowns. Dobbs was rated a three-star recruit by Rivals.com and a four-star by Scout.com. He originally committed to Arizona State University to play college football, but in February 2013, he changed his commitment to the University of Tennessee.
College career
2013 season
As a true freshman at the University of Tennessee in 2013, Dobbs played in five games with four starts after starter Justin Worley suffered an injury in a loss against the #1 Alabama Crimson Tide at Bryant–Denny Stadium. Dobbs came into the game and completed 5 of 12 passes for 75 yards. He made his first career start against the #10 Missouri Tigers at Faurot Field. He completed 26 of 42 passes for 240 yards in the 31–3 loss, which was the most passing yards in a freshman debut since 2004 (Erik Ainge (118) and Brent Schaefer (123) against the UNLV Rebels). After a 55–23 loss to the #7 Auburn Tigers and a 14–10 loss to the Vanderbilt Commodores, Dobbs put together a solid performance against the Kentucky Wildcats at Commonwealth Stadium. In the 27–14 victory, Dobbs threw his first two career touchdown passes and had a 40-yard rushing touchdown. Overall, he completed 72 of 121 passes for 695 yards with two touchdowns and six interceptions and also rushed for 189 yards and a touchdown in his true freshman season.
2014 season
Dobbs competed with Worley (a senior) and Nathan Peterman (a sophomore), to be Tennessee's starter for the 2014 season. Worley was announced the starter, but Dobbs took over as the starter in November after Worley was injured in a 34–3 loss to the #3 Ole Miss Rebels at Vaught–Hemingway Stadium. Although Dobbs was not pushed into action immediately after the injury, in the following week against #4 Alabama Crimson Tide, Peterman was named the starter, but he was relieved quickly by Dobbs. Dobbs performed well in the 34–20 defeat by recording 192 passing yards and two rushing touchdowns against the Crimson Tide. Against South Carolina, Dobbs had a breakout performance against the Gamecocks at Williams–Brice Stadium. In the 45–42 comeback win in overtime, Dobbs had 301 passing yards, two passing touchdowns, 166 rushing yards, and three rushing touchdowns. Against the Kentucky Wildcats at Neyland Stadium, Dobbs had 297 passing yards, three passing touchdowns, 48 rushing yards, and one rushing touchdown in the 50–16 victory. Dobbs and team helped Tennessee reach their first bowl game since the 2010 season. Dobbs was named the 2015 TaxSlayer Bowl MVP in Tennessee's 45–28 victory over Iowa. In the game, Dobbs passed for 129 yards and one touchdown and rushed for 76 yards and two touchdowns. Dobbs threw for 1,206 yards with nine touchdowns and six interceptions during his sophomore season. He finished the 2014 season with 469 yards rushing and eight rushing touchdowns in just six games. Dobbs received two Offensive Player of the Week honors from the Southeastern Conference (SEC), both of which came from his combined passing and rushing performances for over 400 yards in each game.
2015 season
Dobbs entered the 2015 season as Tennessee's starting quarterback. He started and appeared in all 12 regular season games and the bowl game. To open Tennessee's season on September 5, Dobbs recorded 205 passing yards, two passing touchdowns, 89 rushing yards, and one rushing touchdown against the Bowling Green Falcons in a 59–30 win at Nissan Stadium in Nashville, Tennessee. In a double overtime 31–24 loss to the #19 Oklahoma Sooners in the Tennessee 2015 home opener, Dobbs had 125 passing yards, one passing touchdown, 12 rushing yards, and one rushing touchdown. In a 28–27 loss to SEC East rival Florida at Ben Hill Griffin Stadium, Dobbs had a season-high 136 rushing yards and had a 58-yard receiving touchdown thrown by teammate wide receiver Jauan Jennings on a trick play. Dobbs's touchdown reception against Florida was the first reception by a Tennessee quarterback since Peyton Manning caught a 10-yard pass from running back Jamal Lewis in 1997 against Arkansas. Against the rival #19 Georgia Bulldogs, Dobbs had a season-high 312 yards passing and three touchdowns to go along with 118 rushing yards and two touchdowns. His efforts in the game led Tennessee to their first win over the Bulldogs since 2009. Against the #8 Alabama Crimson Tide in their annual rivalry game, Dobbs had 171 yards passing and one passing touchdown in the narrow 19–14 loss at Bryant–Denny Stadium. Against rival South Carolina, Dobbs passed for 255 yards and two touchdowns in the 27–24 home victory. Dobbs led Tennessee to a 9–4 record, which was the most wins for the Tennessee program since 2007. The 2015 season culminated with a 45–6 victory over the #12 Northwestern Wildcats in the 2016 Outback Bowl. In the bowl game, Dobbs had two rushing touchdowns.
2016 season
Dobbs entered the 2016 season as Tennessee's starting quarterback in his final season of collegiate eligibility. He started and appeared in all 12 regular season games and the bowl game. Dobbs started the season with a solid performance in a home game against Appalachian State. In the 20–13 overtime win, Dobbs had 192 yards passing but fumbled on the goal line; the ball was recovered by teammate and running back Jalen Hurd to give Tennessee the go-ahead score. In the 2016 Pilot Flying J Battle at Bristol, Dobbs threw three passing touchdowns to go along with two rushing touchdowns. In a 38–28 comeback victory over the #19 Florida Gators, Dobbs had 319 yards passing, four passing touchdowns, 80 rushing yards, and a rushing touchdown to lead the Volunteers to their first win over the Gators since 2004. Against #25 Georgia, Dobbs had 230 yards passing, three passing touchdowns, and a rushing touchdown to win 34–31. Dobbs's last touchdown was a Hail Mary throw to wide receiver Jauan Jennings as time expired. The winning play is referenced by many as the "Dobbs-Nail Boot". With the victory, Tennessee was 5–0 with Dobbs as quarterback and ranked as high as top 10 in some polls. In a double overtime 45–38 loss to the #8 Texas A&M Aggies at Kyle Field, Dobbs had a season-high 398 passing yards and one passing touchdown. In addition, he caught a receiving touchdown from Jauan Jennings, his second career receiving touchdown. Dobbs continued solid performances over the rest of the season: he had five touchdowns, 223 passing yards and 190 rushing yards in a 63–37 win over Missouri and 340 passing yards in a 45–34 loss against Vanderbilt at Vanderbilt Stadium. Despite his play, Tennessee faded from their 5–0 start to finish 8–4.
In the final game of his Tennessee career, Dobbs led the Volunteers past the #24 Nebraska Cornhuskers by a score of 38–28 in the 2016 Music City Bowl at Nissan Stadium in Nashville. He had 291 passing yards, one passing touchdown, 11 rushes for 118 yards, and three rushing touchdowns. Dobbs was named the MVP of the game.
Dobbs led Tennessee to a second consecutive 9–4 record. Tennessee's 18 wins with Dobbs at the helm were the most for the school over a two-year span since 2006–2007.
Dobbs majored in aerospace engineering during his time at the University of Tennessee. The university presented him with the 2017 Torchbearer Award, the highest honor for an undergraduate student, which recognizes accomplishments in the community and academics. Dobbs was heralded as possessing a perfect 4.0 grade point average and being named to the SEC Academic Honor Roll.
Dobbs was inducted into Omicron Delta Kappa at Tennessee in 2016.
College statistics
Professional career
Pre-draft
Dobbs received an invitation to the Senior Bowl and was named the starting quarterback for the South. He finished the game completing 12-of-15 pass attempts for 102 passing yards and an interception, as the South defeated the North 16–15. The majority of NFL draft experts and analysts projected him to be a fourth to fifth round pick. NFL analyst Mike Mayock projected him to be selected in the second round and NFL.com projected him to be drafted in the third round. After attending the NFL Scouting Combine, he was ranked the seventh best quarterback in the draft by ESPN, the ninth best quarterback by Sports Illustrated, and NFLDraftScout.com ranked him the eighth best quarterback in the draft. He attended Tennessee's Pro Day and scripted his own set of plays; 19 other teammates also participated in Tennessee's Pro Day. He held workouts for six teams: the Kansas City Chiefs, Tennessee Titans, Carolina Panthers, San Diego Chargers, Pittsburgh Steelers, and New Orleans Saints.
Pittsburgh Steelers (first stint)
The Steelers selected Dobbs in the fourth round (135th overall) of the 2017 NFL draft. He was the seventh quarterback selected, and the Steelers also drafted his former Tennessee and Senior Bowl teammate, cornerback Cameron Sutton. He replaced Zach Mettenberger following the draft. On May 22, 2017, the Steelers signed Dobbs to a four-year, $2.95 million contract with a signing bonus of $554,295. He was named the starter for the Steelers' pre-season opener against the New York Giants. After two starts and four appearances during the pre-season, Dobbs spent his entire rookie season behind incumbent starter Ben Roethlisberger and long-term backup Landry Jones.
Dobbs made his NFL regular season debut on October 7, 2018, in a 41–17 Steelers win against the Atlanta Falcons, as on the final play of the game, he kneeled down. On November 4, 2018, in a 23–16 Steelers Week 9 victory against the Baltimore Ravens, Dobbs completed a 22-yard pass to JuJu Smith-Schuster, after stepping in for Ben Roethlisberger, who got injured on the previous play. In Week 14, against the Oakland Raiders, Dobbs once again stepped in for Roethlisberger, who suffered a rib injury. He finished 4-of-9 for 24 yards and one interception in the 24–21 loss. Overall, in the 2018 season, he appeared in five games and went 6-of-12 for 43 yards and one interception.
Jacksonville Jaguars
On September 9, 2019, Dobbs was traded to the Jacksonville Jaguars for a fifth-round pick in the 2020 NFL draft. Dobbs was traded after Mason Rudolph won the backup job for the Steelers, and Jaguars' quarterback Nick Foles sustained a broken clavicle during the season opener and was placed on injured reserve.
While in Jacksonville, Dobbs participated in an internship at NASA's Kennedy Space Center.
On September 5, 2020, Dobbs was waived by the Jaguars.
Pittsburgh Steelers (second stint)
On September 6, 2020, Dobbs was claimed off waivers by the Steelers, his former team. He re-signed with the Steelers on a one-year contract on April 19, 2021.
On August 31, 2021, Dobbs was placed on injured reserve.
Cleveland Browns (first stint)
On April 9, 2022, Dobbs signed a one-year, $1 million deal with the Cleveland Browns. He was waived on November 28, 2022, after Deshaun Watson returned from suspension.
Detroit Lions
On December 5, 2022, Dobbs was signed to the practice squad of the Detroit Lions.
Tennessee Titans
On December 21, 2022, Dobbs was signed by the Titans off the Lions practice squad.
On December 29, with Ryan Tannehill out for the season with an injury and rookie Malik Willis underperforming, Dobbs was named the starter for the Titans Week 17 matchup against the Dallas Cowboys. In his first NFL start, Dobbs completed 20-of-39 passes for 232 yards, his first career touchdown pass, and an interception in the 27–13 loss.
On January 2, head coach Mike Vrabel announced that Dobbs would start the Week 18 matchup against the Jaguars. Needing a win to clinch the division, Dobbs completed 20-of-29 passes for 179 yards to go with a touchdown and an interception. Despite leading for most of the game, Dobbs was sacked from behind by Jaguars safety Rayshawn Jenkins and fumbled the ball, with the Jaguars returning it 37 yards for the go-ahead touchdown with under three minutes to go. The Titans lost 20–16, ultimately costing them a playoff spot.
Cleveland Browns (second stint)
On March 23, 2023, Dobbs signed with the Browns.
Arizona Cardinals
During the 2023 preseason, on August 24, Dobbs was traded to the Arizona Cardinals along with a seventh-round pick in the 2024 NFL draft, in exchange for a fifth-round pick in the 2024 Draft. Dobbs entered the 2023 NFL season as the starting quarterback for the Cardinals, as Kyler Murray started the season on injured reserve.
On September 24, Dobbs led the Cardinals to their first win of the season in an upset over the Cowboys 28–16. At the time, the Cowboys were undefeated at 2–0. This would be Cardinals' only win with Dobbs as starter, going 1–7 through eight games before being traded to the Vikings. He finished his tenure as the Cardinals’ quarterback with 1,569 passing yards, eight passing touchdowns, and five interceptions, as well as 258 rushing yards and three rushing touchdowns.
Minnesota Vikings
After the Minnesota Vikings' starting quarterback Kirk Cousins suffered a season-ending Achilles injury, the Cardinals traded Dobbs, along with a conditional seventh-round pick, to the Vikings in exchange for a sixth-round pick on October 31.
On November 5 against the Falcons, Dobbs entered the game after new starting quarterback Jaren Hall left the game with a concussion. Dobbs had not taken a single practice repetition for the Vikings, and had to rehearse his cadence with the team's offensive linemen during the game. Dobbs threw for 158 yards and scored three total touchdowns in a 31–28 come-from-behind victory. He became the first quarterback in NFL history to record three touchdowns in consecutive games while playing for different teams and was named as the NFC player of the week for his performance. Dobbs during this time received increased media attention for his journeyman career and sudden unexpected success. His nickname "The Passtronaut," referring to Dobbs' background in aerospace engineering, first appeared in October 2023 and gained prominence during this period.
After losses to the Denver Broncos and the Chicago Bears, Dobbs was benched in the second half of the Vikings' Week 14 game against the Las Vegas Raiders after completing 10-of-23 passes for 63 yards and scoring no points for Minnesota through three quarters. After backup quarterback Nick Mullens led the Vikings to a game-winning drive in the fourth quarter, which resulted in a 3–0 victory, the team announced that Mullens would be the starter moving forward, and Dobbs was relegated to backup. He was later demoted to the third-string quarterback after head coach Kevin O'Connell announced that Jaren Hall would backup Mullens.
San Francisco 49ers
On March 19, 2024, Dobbs signed a one-year contract with the San Francisco 49ers.
Dobbs spent the majority of the season as the third-string quarterback behind Brock Purdy and Brandon Allen. He saw his first snaps of the season in Week 17 against the Detroit Lions after Purdy departed late in the fourth quarter with an injury. In his absence, Dobbs threw for 35 yards and ran for a seven-yard touchdown as the 49ers lost 40–34. With Purdy injured, the 49ers named Dobbs their starter for their final game of the season against the Cardinals.
NFL career statistics
Personal life
Dobbs is a Christian. He has spoken about the most important day in his life by saying, "That’s the day I got baptized and went public with the decision of shedding my old life and putting on the new and starting a relationship with Jesus Christ. The day will come that I won't be a part of any football team. But the decision I made during my sophomore year in high school — to be a part of Team Jesus — I'll be a part of that team for the rest of my life, and for all eternity."
Dobbs is the founder of the ASTROrdinary Dobbs Foundation.
Dobbs is an advocate for awareness about alopecia, a hair loss condition that personally affects him.
Dobbs' cousin, Parker Washington, is a wide receiver for the Jaguars.
References
External links
San Francisco 49ers bio
Tennessee Volunteers bio
1995 births
Living people
Aerospace engineers
American football quarterbacks
Arizona Cardinals players
Cleveland Browns players
Detroit Lions players
Jacksonville Jaguars players
Minnesota Vikings players
People with autoimmune disease
Pittsburgh Steelers players
Players of American football from Fulton County, Georgia
San Francisco 49ers players
Sportspeople from Alpharetta, Georgia
Tennessee Titans players
Tennessee Volunteers football players | Joshua Dobbs | [
"Engineering"
] | 3,696 | [
"Aerospace engineers",
"Aerospace engineering"
] |
44,295,168 | https://en.wikipedia.org/wiki/Multifurca%20zonaria | Multifurca zonaria is a species of mushroom-forming fungus in the genus Russulaceae. Originally described from Thailand as a Russula species in 2003, it was moved to the newly created genus Multifurca in 2008.
References
External links
Russulales
Fungi described in 2003
Fungi of Thailand
Fungus species | Multifurca zonaria | [
"Biology"
] | 64 | [
"Fungi",
"Fungus species"
] |
44,295,354 | https://en.wikipedia.org/wiki/Multifurca%20roxburghii | Multifurca roxburghii is a species of mushroom-forming fungus in the genus Russulaceae. Found in Himachal Pradesh, India, where it associates with chir pine (Pinus roxburghii). It was described as new to science in 2008, then under the name "M. roxburghiae", which is now considered an orthographic variant.
References
External links
Russulales
Fungi described in 2008
Fungi of Asia
Fungus species | Multifurca roxburghii | [
"Biology"
] | 96 | [
"Fungi",
"Fungus species"
] |
51,473,136 | https://en.wikipedia.org/wiki/Rolapitant | Rolapitant (INN, trade name Varubi in the US and Varuby in the European Union) is a drug originally developed by Schering-Plough and licensed for clinical development by Tesaro, which acts as a selective NK1 receptor antagonist (antagonist for the NK1 receptor). It has been approved as a medication for the treatment of chemotherapy-induced nausea and vomiting (CINV) after clinical trials showed it to have similar or improved efficacy and some improvement in safety over existing drugs for this application.
Medical uses
Rolapitant is used in combination with other antiemetic (anti-vomiting) agents in adults for the prevention of delayed nausea and vomiting associated with initial and repeat courses of emetogenic cancer chemotherapy, including, but not limited to, highly emetogenic chemotherapy. The approved antiemetic combination consists of rolapitant plus dexamethasone and a 5-HT3 antagonist.
Contraindications
Under the US approval, rolapitant is contraindicated in combination with thioridazine, whose inactivation could be inhibited by rolapitant. Under the European approval, it is contraindicated in combination with St. John's Wort, which is expected to accelerate inactivation of rolapitant.
Side effects
In studies comparing chemotherapy plus rolapitant, dexamethasone and a 5-HT3 antagonist to chemotherapy plus placebo, dexamethasone and a 5-HT3 antagonist, most side effects had comparable frequencies in both groups, and differed more between chemotherapy regimens than between rolapitant and placebo groups. Common side effects included decreased appetite (9% under rolapitant vs. 7% under placebo), neutropenia (9% vs. 8% or 7% vs. 6%, depending on the kind of chemotherapy), dizziness (6% vs. 4%), indigestion and stomatitis (both 4% vs. 2%).
Overdose
Up to eightfold therapeutic doses have been given in studies without problems.
Interactions
Rolapitant moderately inhibits the liver enzyme CYP2D6. Blood plasma concentrations of the CYP2D6 substrate dextromethorphan have increased threefold when combined with rolapitant; and increased concentrations of other substrates are expected. The drug also inhibits the transporter proteins ABCG2 (breast cancer resistance protein, BCRP) and P-glycoprotein (P-gp), which has been shown to increase plasma concentrations of the ABCG2 substrate sulfasalazine twofold and the P-gp substrate digoxin by 70%.
Strong inducers of the liver enzyme CYP3A4 decrease the area under the curve of rolapitant and its active metabolite (called M19); for rifampicin, this effect was almost 90% in a study. Inhibitors of CYP3A4 have no relevant effect on rolapitant concentrations.
Pharmacology
Pharmacodynamics
Both rolapitant and its active metabolite M19 block the NK1 receptor with high affinity and selectivity: to block the closely related receptor NK2 or any other of 115 tested receptors and enzymes, more than 1000-fold therapeutic concentrations are necessary.
Pharmacokinetics
Rolapitant is practically completely absorbed from the gut, independently of food intake. It undergoes no measurable first-pass effect in the liver. Highest blood plasma concentrations are reached after about four hours. When in the bloodstream, 99.8% of the substance are bound to plasma proteins.
It is metabolized by the liver enzyme CYP3A4, resulting in the major active metabolite M19 (C4-pyrrolidine-hydroxylated rolapitant) and a number of inactive metabolites. Rolapitant is mainly excreted via the feces (52–89%) in unchanged form, and to a lesser extent via the urine (9–20%) in form of its inactive metabolites. Elimination half-life is about seven days (169 to 183 hours) over a wide dosing range.
Chemistry
The drug is used in form of rolapitant hydrochloride monohydrate, a white to off-white, slightly hygroscopic crystalline powder. Its maximum solubility in aqueous solutions is at pH 2–4.
References
External links
Antiemetics
CYP2D6 inhibitors
NK1 receptor antagonists
Trifluoromethyl compounds
Spiro compounds
Drugs developed by GSK plc
Gamma-lactams
Pyrrolidones
Piperidines | Rolapitant | [
"Chemistry"
] | 978 | [
"Organic compounds",
"Spiro compounds"
] |
51,474,451 | https://en.wikipedia.org/wiki/Menger%20space | In mathematics, a Menger space is a topological space that satisfies a certain basic selection principle that generalizes σ-compactness. A Menger space is a space in which for every sequence of open covers of the space there are finite sets such that the family covers the space.
History
In 1924, Karl Menger
introduced the following basis property for metric spaces:
Every basis of the topology contains a countable family of sets with vanishing
diameters that covers the space. Soon thereafter,
Witold Hurewicz
observed that Menger's basis property can be reformulated to the above form using sequences of open covers.
Menger's conjecture
Menger conjectured that in ZFC every Menger metric space is σ-compact.
A. W. Miller and D. H. Fremlin
proved that Menger's conjecture is false, by showing that there is,
in ZFC, a set of real numbers that is Menger but not σ-compact.
The Fremlin-Miller proof was dichotomic, and the set witnessing the failure
of the conjecture heavily depends on whether a certain (undecidable) axiom
holds or not.
Bartoszyński and Tsaban
gave a uniform ZFC example of a Menger subset of the real line that is not σ-compact.
Combinatorial characterization
For subsets of the real line, the Menger property can be characterized using continuous functions into the Baire space .
For functions , write if for all but finitely many natural numbers . A subset of is dominating if for each function there is a function such that . Hurewicz proved that a subset of the real line is Menger iff every continuous image of that space into the Baire space is not dominating. In particular, every subset of the real line of cardinality less than the dominating number is Menger.
The cardinality of Bartoszyński and Tsaban's counter-example to Menger's conjecture is
.
Properties
Every compact, and even σ-compact, space is Menger.
Every Menger space is a Lindelöf space
Continuous image of a Menger space is Menger
The Menger property is closed under taking subsets
Menger's property characterizes filters whose Mathias forcing notion does not add dominating functions.
References
Properties of topological spaces
Topology | Menger space | [
"Physics",
"Mathematics"
] | 472 | [
"Properties of topological spaces",
"Space (mathematics)",
"Topological spaces",
"Topology",
"Space",
"Geometry",
"Spacetime"
] |
51,474,724 | https://en.wikipedia.org/wiki/CL%20J1001%2B0220 | CL J1001+0220 is, as of 2016, the most distant known galaxy cluster. Discovered in 2016 by the Chandra X-ray Observatory in conjunction with the ESO's UltraVISTA telescope and the Atacama Large Millimeter Array, it has a redshift of z=2.506, placing it at a distance of 11.1 billion light-years from Earth. The galaxy cluster appears to be undergoing the transformation from a galaxy cluster that is still forming, a proto-cluster, to a mature cluster, and it is the first such cluster observed in this stage of its evolution.
The cluster consists of seventeen galaxies, and nine of the eleven massive galaxies closest to its center are starburst galaxies which together are forming new stars at the rate of about 3,400 solar masses () per year. In contrast, the Milky Way produces only the equivalent of one solar mass per year, so these galaxies at the core of the cluster are producing stars at a rate three thousand times greater than the Milky Way on average. Other galaxy clusters at ten billion light years and closer have far less star formation, and this suggests that star formation slows down in large galaxies within clusters after the galaxies have already come together during the development of a galaxy cluster.
References
Galaxy clusters
Starburst galaxies | CL J1001+0220 | [
"Astronomy"
] | 266 | [
"Galaxy clusters",
"Sextans",
"Astronomical objects",
"Constellations"
] |
51,474,972 | https://en.wikipedia.org/wiki/Coal%20bin | A coal bin, coal store or coal bunker is a storage container for coal awaiting use or transportation. This can be either in domestic, commercial or industrial premises, or on a ship or locomotive tender, or at a coal mine or processing plant.
Domestic coal bunkers are associated with the use of coal in open fires or for solid-fuel central heating. Free-standing bunkers were commonly made of wood or concrete and are currently sold in materials including plastic or galvanised metal. Coal bins or bunkers could also form an outhouse or be partly or fully underground.
Coal bins form or formed part of industrial plants, and were found on steam ships.
See also
Tender (rail)
References
Semi-subterranean structures
Bin | Coal bin | [
"Engineering"
] | 148 | [
"Architecture stubs",
"Architecture"
] |
51,476,095 | https://en.wikipedia.org/wiki/Green%20earth | Green earth, also known as terre verte and Verona green, is an inorganic pigment derived from the minerals celadonite and glauconite. Its chemical formula is .
First used by the ancient Romans, green earth has been identified on wall paintings at Pompeii and Dura-Europos. The Renaissance painter and writer Cennino Cennini claimed that “the ancients never gilded except with this green” being used as a bole, or undercoating. In the Middle Ages one of its best-known uses was in the underpainting of flesh tones.
Green earths have been rather confusingly referred to as "verda terra" or "terra verde di Verona", which scholars have assumed incorrectly referred to Veronese green, which is actually an emerald green pigment much used in the 18th century. SEM/EDAXS data have demonstrated that it is possible to discriminate between these two sources of celadonite in Roman wall paintings through the presence of trace elements. Spectroscopically, therefore, the analytical challenge is to differentiate between the green earths celadonite and glauconite, and perhaps chlorite, and the copper-containing malachite and verdigris, with the added ability to recognize the presence of haematite, Egyptian blue, calcite, dolomite, and carbon which have been added to change the colour tones.
High quality deposits can be found in England, France, Cyprus, Germany and at Monte Baldo near Verona in Italy. The color ranges from neutral yellow green to pale greenish gray to dark matte olive green.
See also
List of inorganic pigments
References
Inorganic pigments | Green earth | [
"Chemistry"
] | 346 | [
"Inorganic pigments",
"Inorganic compounds"
] |
51,477,097 | https://en.wikipedia.org/wiki/Kindara | Kindara is a femtech company headquartered in Colorado that develops apps that help women identify their fertile window. The products are used for women trying to get pregnant, or women who want to track their menstrual cycle for overall health. Their latest product, Priya Fertility and Ovulation Monitor, maximizes a woman's chance of getting pregnancy by identifying her most fertile days.
Overview
Kindara was founded in 2011 by husband-and-wife team Will Sacks and Kati Bicknell. The company launched its free mobile application in 2012. Kindara's mobile application allows women to track signs of fertility, such as basal body temperature, cervical fluid, and the position of the cervix to determine when ovulation is occurring. Kindara also sells a thermometer, Wink, which records basal body temperature and syncs automatically to the Kindara fertility application.
References
Medical technology
Women's health
Companies based in Boulder, Colorado
Fertility awareness
Mobile applications | Kindara | [
"Biology"
] | 199 | [
"Biotechnology stubs",
"Medical technology stubs",
"Medical technology"
] |
51,477,178 | https://en.wikipedia.org/wiki/Approximate%20group | In mathematics, an approximate group is a subset of a group which behaves like a subgroup "up to a constant error", in a precise quantitative sense (so the term approximate subgroup may be more correct). For example, it is required that the set of products of elements in the subset be not much bigger than the subset itself (while for a subgroup it is required that they be equal). The notion was introduced in the 2010s but can be traced to older sources in additive combinatorics.
Formal definition
Let be a group and ; for two subsets we denote by the set of all products . A non-empty subset is a -approximate subgroup of if:
It is symmetric, that is if then ;
There exists a subset of cardinality such that .
It is immediately verified that a finite 1-approximate subgroup is the same thing as a genuine subgroup. Of course this definition is only interesting when is small compared to (in particular, any subset is a -approximate subgroup). In applications it is often used with being fixed and going to infinity.
Examples of approximate subgroups which are not groups are given by symmetric intervals and more generally arithmetic progressions in the integers. Indeed, for all the subset is a 2-approximate subgroup: the set is contained in the union of the two translates and of . A generalised arithmetic progression in is a subset in of the form , and it is a -approximate subgroup.
A more general example is given by balls in the word metric in finitely generated nilpotent groups.
Classification of approximate subgroups
Approximate subgroups of the integer group were completely classified by Imre Z. Ruzsa and Freiman. The result is stated as follows:
For any there are such that for any -approximate subgroup there exists a generalised arithmetic progression generated by at most integers and containing at least elements, such that .
The constants can be estimated sharply. In particular is contained in at most translates of : this means that approximate subgroups of are "almost" generalised arithmetic progressions.
The work of Breuillard–Green–Tao (the culmination of an effort started a few years earlier by various other people) is a vast generalisation of this result. In a very general form its statement is the following:
Let ; there exists such that the following holds. Let be a group and a -approximate subgroup in . There exists subgroups with finite and nilpotent such that , the subgroup generated by contains , and with .
The statement also gives some information on the characteristics (rank and step) of the nilpotent group .
In the case where is a finite matrix group the results can be made more precise, for instance:
Let . For any there is a constant such that for any finite field , any simple subgroup and any -approximate subgroup then either is contained in a proper subgroup of , or , or .
The theorem applies for example to ; the point is that the constant does not depend on the cardinality of the field. In some sense this says that there are no interesting approximate subgroups (besides genuine subgroups) in finite simple linear groups (they are either "trivial", that is very small, or "not proper", that is almost equal to the whole group).
Applications
The Breuillard–Green–Tao theorem on classification of approximate groups can be used to give a new proof of Gromov's theorem on groups of polynomial growth. The result obtained is actually a bit stronger since it establishes that there exists a "growth gap" between virtually nilpotent groups (of polynomial growth) and other groups; that is, there exists a (superpolynomial) function such that any group with growth function bounded by a multiple of is virtually nilpotent.
Other applications are to the construction of expander graphs from the Cayley graphs of finite simple groups, and to the related topic of superstrong approximation.
Notes
References
Group theory
Geometric group theory
Additive combinatorics | Approximate group | [
"Physics",
"Mathematics"
] | 809 | [
"Geometric group theory",
"Group actions",
"Additive combinatorics",
"Combinatorics",
"Group theory",
"Fields of abstract algebra",
"Symmetry"
] |
51,477,367 | https://en.wikipedia.org/wiki/The%20Climate%20Mobilization | The Climate Mobilization (TCM) is a grassroots environmental advocacy group working toward large-scale political action against global warming. It believes that the crisis of climate change requires a national economic effort on the scale of the American mobilization of the home front during World War II., in order to transform the USA economy speedily.
TCM was founded by Margaret Klein Salamon to confront climate change denial and build the political will necessary to achieve the rapid and just transformation of the physical economy and society at large, delivering an integrated package of solutions for a regenerative, zero emissions and safe-climate economy, geared toward reversing global warming and the sixth mass extinction of species as rapidly as possible.
History
Since at least 2008, public figures like environmental analyst Lester Brown, former vice president Al Gore, author and energy expert Joseph J. Romm, New York Times columnist Thomas Friedman, writer Naomi Klein, and climate activist Bill McKibben have called for governmental climate action on the scale of the World War II mobilization to rapidly reduce greenhouse gas emissions. In 2011, the heads of leading environmental organizations including 350.org, Sierra Club, Greenpeace, Friends of the Earth, and Rainforest Action Network signed a letter to Presidents Barack Obama and Hu Jintao calling for a "wartime-like mobilization" by the governments of the United States and China to cut carbon emissions 80% (based on 2006 levels) by 2020. However, environmental groups in the United States never organized politically for such an ambitious goal.
The Climate Mobilization was launched in September 2014, before the People's Climate March in New York City, specifically to organize politically around the concept of a rapid, World War II-scale government mobilization against climate change. Margaret Klein Salamon, Ezra Silk and allies developed a pledge-based movement-building strategy in which signers agree to vote for political candidates who have signed the pledge over those who have not. The Climate Mobilization's "Pledge to Mobilize" calls on the United States government to commence a World War II-scale mobilization against climate change in order to decrease net greenhouse gas emissions 100% by 2025, deploy a system of removing greenhouse gases (GHG) from the atmosphere with wartime speed, and make reducing net GHGs 100% globally, with the same swiftness, a top political priority.
Throughout 2015, citizen activists in California, Iowa and elsewhere in the U.S. began rallying for World War II-scale national climate mobilization, and spreading the Climate Mobilization pledge to local political candidates.
In January 2016, The Climate Mobilization sponsored a "Climate Emergency Caucus" in Des Moines before the Iowa caucuses, which simulated the state's 2016 Democratic presidential primary caucus. Former U.S. Senator Tom Harkin spoke on behalf of candidate Hillary Clinton, and climate advocates Jane Kleeb, founder of Bold Nebraska, and Iowa politician and radio host Ed Fallon spoke on behalf of candidate Bernie Sanders. Sanders won 67% of the vote, reinforcing the perception that voters highly concerned about climate change strongly preferred Sanders over Clinton, and that climate voters were a key voting bloc contributing to his competitiveness in Iowa and later primary states. Throughout his presidential campaign, Sanders discussed fighting climate change "in military terms", saying at one point during a debate against Clinton that "if we approach this as if we were at war", the U.S. could be up to the challenge, as it was during World War II.
In April 2016, The Climate Mobilization organized a "die-in" outside the United Nations building in New York City during the signing of the COP 21 Paris Agreement, meant to protest what the group called the agreement's inadequacy in relation to the scale of the threat of climate change. TCM deputy director Ezra Silk called the agreement "historic in the sense that the Munich Agreement was historic—a catastrophic act of appeasement meant to maintain business-as-usual arrangements." He explained: "It's widely recognized that this agreement is not even close to what is needed... It doesn't really convey a sense of urgency [so] we wanted to sort of inject some reality into the discussion. We need to go on to an emergency war footing like right now ... The climate is already dangerous, we're already in an emergency. It is understood within the climate movement that this is the kind of approach that is needed. It's just considered politically unrealistic. Our goal is to change the political possibility."
In July 2016, the national platform committee of the Democratic Party of the United States approved an amendment submitted by Climate Mobilization activist Russell Greene committing the party to a World War II-scale international mobilization against climate change: "We believe the United States must lead in forging a robust global solution to the climate crisis. We are committed to a national mobilization, and to leading a global effort to mobilize nations to address this threat on a scale not seen since World War II. In the first 100 days of the next administration, the President will convene a summit of the world's best engineers, climate scientists, policy experts, activists, and indigenous communities to chart a course to solve the climate crisis."
Politicians who have signed the Climate Mobilization pledge include San Luis Obispo mayor Heidi Harmon, Des Moines mayor Frank Cownie; Iowa State Rep. Dan Kelley; Iowa State Senator and U.S. Senate candidate Rob Hogg; New York State Senate candidate Debbie Medina; and U.S. congressional candidates Peter Jacob of New Jersey, and Tim Canova, Darren Soto, and Alina Valdes of Florida.
Advisory board
TCM's advisory board includes:
Laura Dawn, former MoveOn.org creative director
Paul Gilding, former Greenpeace International director
Richard Heinberg, journalist and Post Carbon Institute senior fellow
Marshall Herskovitz, film producer
Dr. Michael E. Mann, climate scientist
Adam McKay, producer, director, screenwriter of films such as The Big Short
Jamila Raqib, director of the Albert Einstein Institution
Gus Speth, environmental lawyer
David Spratt and Philip Sutton, coauthors of Climate Code Red
Lise Van Susteren, psychiatrist and environmental activist
Rev. Lennox Yearwood Jr. of the Hip Hop Caucus
See also
War economy
Mass production of equipment during World War 2
Large-scale plant propagation
References
External links
Climate change organizations based in the United States
Emissions reduction
Environmental policies organizations
International climate change organizations
Non-profit organizations based in New York City
Political organizations based in the United States
Politics of climate change
Environmental organizations established in 2014 | The Climate Mobilization | [
"Chemistry"
] | 1,332 | [
"Greenhouse gases",
"Emissions reduction"
] |
51,477,838 | https://en.wikipedia.org/wiki/Consumer%20culture | Consumer culture describes a lifestyle hyper-focused on spending money to buy material or goods. It is often attributed to, but not limited to, the capitalist economy of the United States. During the 20th century, market goods came to dominate American life, and for the first time in history, consumerism had no practical limits. Consumer culture has provided affluent societies with alternatives to tribalism and class war.
Consumer culture began to increase rapidly during the extreme economic growth of the Roaring Twenties. The challenge for the future is to find ways to revive the valid portion of the culture of constraint and control the overpowering success of the twentieth century.
Types of culture
Social scientists Arthur Berger, Aaron Wildavsky, and Mary Douglas have suggested that there are four political and consumer cultures possible in a democratic society: hierarchical/elitist, individualist, egalitarian, and fatalist.
Hierarchical/Elitist: Someone with the belief that a system or society should be ruled, dominated, or otherwise controlled by a group of individuals determined to be of higher standing than others.
Individualist: Someone who puts the needs of the individual before the needs of others.
Egalitarian: Someone that believes that peoples' needs and rights should be equal, fair, and cared for.
Fatalist: Someone with the belief that future events are inevitable, and thus there is little to no point in attempting to alter them.
Mass market theory
Advertising and strategies
To improve the effectiveness of advertisements, people of various age groups are employed by marketing companies to increase the understanding of the beliefs, attitudes, and values of the targeted consumers.
A quote by Shah states that "The sophistication of advertising methods and techniques has advanced, enticing and shaping and even creating consumerism and needs where there has been none before".
Anthropologist Richard R. Wilk has written about bottled water and the consumerist basis it has in society. The base point of this article is to point out how water is free, and it is abundant, but over time it has become a point of marketing. The debate has always existed if there is a real difference in taste between bottled water and tap water. When it comes down to it, during many blind tastes, people cannot even tell which was tap and which was bottled, and more often than not tap water won for better taste. Water has always been regarded as a pure substance and has connections in many religions. Throughout history, it has been shown that control over water is equivalent to control over untamed nature, and this has been shown in movies as well. To build on this idea, Wilk points out how having bottled water enforces the idea of this control over nature and the need that humans have for water. To further enforce this idea of natural and pure water, a 1999 report by the National Resources Defense Council found that many water companies use words like “pure” and “pristine” to aid in marketing. Wilk explains that it is more than just the marketing of it being pure, but that people want bottled water because they know the source. Public water comes from an anonymous source and Wilk concludes that the home is an extension of ourselves, so why would we want to bring an unknown specimen into our home? This is where the bottled water preference comes in, according to Wilk, because people can trace it back to where it came from. In addition to this idea, many brands and companies have started marketing water toward specific needs like special water for women, kids, athletes, and so on. This increases competition between brands and takes away from customers being able to choose what water they want. This is due to the larger companies being able to make more connections and pay the expensive fee to be sold on the shelves. Wilk concludes that since it is hard to trust either, it comes down to which is distrusted least.
Industrial Revolution
Wage work
Before the Industrial Revolution, the home was a place where men and women produced, consumed, and worked. The men were highly valued workers, such as barbers, butchers, farmers, and lumbermen who brought income into the house. The wives of these men completed various tasks to save money which included, churning butter, fixing clothes, and tending the garden. This system created an equal value for all of the jobs and tasks in a community. Once the Industrial Revolution began, there was no such thing as equal and high valued work in a mass production industry. The only value these workers had were the wage they made. That meant the wives lost their value at home and had to start working for a living. This new system created the thought of everyone being replaceable.
Life of the worker
The life of a worker was a challenging one. Working 12 to 14-hour days, 6 days a week, and in a dangerous environment. The worst part was the infrequency of pay or not being paid at all. At times, employers paid their workers in script pay, non-U.S. currency, or even in-store credit.
See also
References
Consumer behaviour | Consumer culture | [
"Biology"
] | 1,014 | [
"Behavior",
"Consumer behaviour",
"Human behavior"
] |
51,478,216 | https://en.wikipedia.org/wiki/Increased%20limit%20factor | Increased limit factors or ILFs are multiplicative factors that are applied to premiums for "basic" limits of coverage to determine premiums for higher limits of coverage. They are commonly used in casualty insurance pricing.
Overview
Often, limited data is available to determine appropriate charges for high limits of insurance. In order to price policies with high limits of insurance adequately, actuaries may first determine a "basic limit" premium and then apply increased limits factors. The basic limit is a lower limit of liability under which there is a more credible amount of data.
For example, basic limit loss costs or rates may be calculated for many territories and classes of business. At a relatively low limit of liability, such as $100,000, there may be a high volume of data that can be used to derive those rates. For higher limits, there may be a credible volume of data at the countrywide level but not much data available for individual territories or classes. Increased limit factors can be derived at the countrywide level (or some other broad grouping) and then applied to the basic limit rates to arrive at rates for higher limits of liability.
Formula
An increased limit factor (ILF) at limit L relative to basic limit B can be defined as
where ALAE is the allocated loss adjustment expense provision, ULAE is the unallocated loss adjustment expense provision, and RL is the risk load provision.
An indemnity-only ILF can be expressed as
Often, frequency is assumed to be independent of the policy limit, in which case the formula can be simplified to
The expected severity at each limit is often referred to as "limited average severity," or LAS.
Examples
In the United States, many insurers use ILFs published by the Insurance Services Office, a division of Verisk.
References
Further reading
External links
Actuarial science | Increased limit factor | [
"Mathematics"
] | 371 | [
"Applied mathematics",
"Actuarial science"
] |
51,478,252 | https://en.wikipedia.org/wiki/Thinx | Thinx is a New York–based company that sells period underwear, an undergarment designed to be as absorbent as traditional feminine hygiene products. Since 2022, Kimberly-Clark has had a majority stake in the business.
History
Thinx was founded in 2011 by Antonia Saint Dunbar, Miki Agrawal, and Radha Agrawal. In 2018, Thinx released a new line called (BTWN), which offers period underwear for teens and tweens. In June 2019, Thinx released Thinx Air, a quick-drying version of its underwear. As of 2021, Thinx has released its first activewear collection, which includes leggings, cycle shorts, training shorts, and leotards that are available in multiple colors. The four-piece collection functions like other Thinx underwear, but the gusset design is longer and shaped differently to accommodate active lifestyles. Miki Agrawal stepped down as CEO in 2017, after a former employee alleged that she had engaged in inappropriate office behavior. Maria Molland took over as CEO, and under her leadership, Thinx was placed on shelves in Target and Walmart.
In 2019, Kimberly-Clark made a minority investment in Thinx, and in February 2022, it acquired a majority stake in the company. In May 2022, Maria Molland stepped down as CEO, and the company appointed Meghan Davis as its new CEO.
Lawsuits
In 2020, lawsuits were filed against Thinx alleging misleading marketing following an independent test of the company's products that revealed the presence of per- and polyfluoroalkyl substances (PFAS), a type of chemical found in consumer products and linked to numerous long-term health risks. The lawsuits called into question whether Thinx marketing claim that its products were "organic, sustainable and nontoxic" was deceptive. In May 2022, the lawsuits were combined into a proposed class action, and the company reached a settlement in the case in November. In January 2023, the terms of the settlement were announced to consumers, which included no admission of wrongdoing and the company agreeing to pay up to US$5 million to consumers. Thinx also put out a statement alleging that PFAS are not part of the product design and going forward, it would ensure PFAS are not added to its products.
On January 29, 2024, CEO Meghan Davis announced on a company-wide Zoom call that 95 of the 109 staff members would be losing their jobs on May 1. Five of the laid-off employees were offered positions as employees of Kimberly-Clark, Thinx's parent company.
Products
Thinx underwear comes in a range of styles from boyshorts to thongs and includes two patented technologies. One is to absorb different amounts of blood, and the other absorbs different amounts of urine. The underwear has been reported as being antimicrobial, moisture-wicking, absorbent, and leak resistant. In 2019, Thinx launched Thinx Super, which is a double-absorbency product that claims to hold up to four tampons' worth of flow. The underwear cost about $35 per pair. Thinx introduced a pair that cost $17 in order to better compete with new lines of period underwear from large brands like Aerie and Hanes.
Marketing
Thinx earned a reputation for its controversial ads. In October 2015, Outfront Media rejected Thinx's subway advertisements due to the fact that the ads used the word "period" and included suggestive visuals of food. Following a social media outcry, the ads were finally allowed to be shown. In 2016, Thinx received attention for featuring trans male models in its ads for period underwear. In November 2016, Thinx launched an ad referencing the Donald Trump Access Hollywood tape. The San Francisco subway banned the ads due to the use of the word "pussy". In November 2017, they created a "PMS truck", a truck visiting three cities, allowing visitors to step inside to shop for Thinx products and talk with brand representatives regarding period health. In 2019, Thinx rolled out a national ad campaign featuring a young boy getting his first period with the tagline: "What if we all had periods?" and subsequent campaigns focused on reducing period stigma by showcasing men. These ads were banned by several TV networks including CBS for being "too graphic".
After 2019, employees noticed that Thinx's marketing direction changed, featuring fewer images of people in underwear, and treating periods like something to hide. In 2022, a television showed a mom starting to demonstrate tampon use to her daughter before a sister interrupts the scene with Thinx underwear, saying "Mom won't have to show you how to use them." Employees felt that Thinx's advertising no longer destigmatized menstruation.
Reception
TIME named Thinx period panties as one of the best inventions of 2015. Fast Company named Thinx one of the most innovative companies of 2017, pointing to founder Agrawal's promotional campaigns and her application of "high-tech merchandise, considered design, and a rule-breaking philosophy" to launches of new products.
In 2019 Thinx leaders signed a letter condemning the abortion bans being put into place across the country.
See also
Menstrual cup
Period underwear
Tampon
Lunapads
Pantyliners
References
External links
Thinx Official Website
Feminine hygiene
Feminine hygiene brands
Menstrual cycle
Personal hygiene products
Incontinence | Thinx | [
"Biology"
] | 1,116 | [
"Incontinence",
"Excretion"
] |
51,479,731 | https://en.wikipedia.org/wiki/Methaniazide/thioacetazone | Methaniazide/thioacetazone, sold under the brand name Neothetazone, is an antibiotic combination of methaniazide (neotizide) and thioacetazone that is or was very commonly used in the treatment of tuberculosis. It has been implicated as a cause of gigantomastia in a single 1970 case report, and, along with D-penicilliamine, bucillamine, ciclosporin, and indinavir, is one of the only drugs to have been associated with gigantomastia.
See also
Conteben
Isoniazid
References
Antibiotics
Combination antibiotics
Anti-tuberculosis drugs | Methaniazide/thioacetazone | [
"Biology"
] | 137 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
51,481,292 | https://en.wikipedia.org/wiki/Samsung%20Gear%20S3 | The Samsung Gear S3 is a Tizen-based circular smartwatch developed by Samsung Electronics. It was released on 18 November 2016.
There are two models of the Gear S3, Classic and Frontier. The Classic has a silver watch case and black leather band, while the Frontier has a black watch case and rubber band. Both are rated IP68 (water resistant) and have GPS and heart rate monitor sensors. One notable feature is that the bezel ring rotates as part of the user interface, although users can also navigate by swiping the screen and/or using the two buttons on the side.
The Gear S3's successor, the Samsung Galaxy Watch, was released 9 August 2018.
Comparison of models
The "LTE" models are further divided into sub-models depending on the target country and Service Provider cellular infrastructure available.
See also
Samsung Galaxy
References
External links
Official page
New Tizen 3.0 Update Now Available For Samsung Gear S3
Tizen-based devices
Products introduced in 2016
Smartwatches
Samsung wearable devices | Samsung Gear S3 | [
"Technology"
] | 212 | [
"Smartwatches"
] |
51,483,280 | https://en.wikipedia.org/wiki/Sustainable%20Urban%20Mobility%20Plan | A Sustainable Urban Mobility Plan (SUMP) is a planning concept applied by local and regional authorities for strategic mobility planning. It encourages a shift towards more sustainable transport modes and supports the integration and balanced development of all modes. A SUMP is instrumental in solving urban transport problems and reaching local and higher-level environmental, social, and economic objectives. Sustainable Urban Mobility Plans are defined as "a strategic plan designed to satisfy the mobility needs of people and businesses in cities and their surroundings for a better quality of life. It builds on existing planning practices and takes due consideration of integration, participation, and evaluation principles.”
European policy background
In 2009, the European Commission first adopted the Action Plan on Urban Mobility, which proposes measures to encourage and help local, regional and national authorities in achieving their goals for sustainable urban mobility. Also the 2011 Transport White Paper “Roadmap to a Single European Transport Area - Towards a competitive and resource efficient transport system” advises cities to develop Sustainable Urban Mobility Plans. The European Commission adopted the Urban Mobility Package “Together towards competitive and resource-efficient urban mobility” in December 2013. Sustainable urban mobility planning is emphasized in the Urban Mobility Package alongside urban freight distribution, urban access regulations, deployment of intelligent transportation system (ITS) solutions in urban areas and road traffic safety. In its annex, the Urban Mobility Package includes a comprehensive definition and explanation of the SUMP concept which was developed based on a discussion and exchange process between planning experts and stakeholders across the European Union.
Now, Sustainable Urban Mobility Planning is Europe's de facto urban transport planning concept. Since the publication of the Urban Mobility Package in 2013, the concept of Sustainable Urban Mobility Plans has been widely taken up across Europe and internationally.
SUMP Guidelines
The Guidelines for Developing and Implementing a Sustainable Urban Mobility Plan (or SUMP Guidelines) are the result of an intense one-year stakeholder engagement process, coordinated by main authors Rupprecht Consult and led by a special editorial board, which includes DG MOVE, the CIVITAS SUMP projects, Eltis, INEA, DG REGIO, JASPERS, and leading mobility researchers. The Guidelines have been developed and validated in close cooperation with the SUMP community of European cities. By involving several major city networks closely in the update, special care was taken to include feedback from all types of cities and regions. The Guidelines are based on the eight Sustainable Planning Principles and describe all phases of a Sustainable Urban Mobility Plan from Phase 1: Preparation & Analysis, Phase 2: Strategy development, Phase 3: Measure Planning to Phase 4: Implementation & Monitoring. The phases are subdivided into different steps, each explained with best practice examples from cities, instruments and tools to support the process, tasks and a checklist for planners.
The main document is complemented by an Annex which includes a Glossary, a comprehensive checklist and over 50 detailed good practice examples.
Objectives and aims
A Sustainable Urban Mobility Plan addresses all modes and forms of urban and regional transport. It aims to provide sustainable and high-quality transport and mobility in the agglomeration and enhance its accessibility. Instead of addressing the needs of the administrative area only, a SUMP regards the entire urban area including its commuter hinterland. A SUMP integrates technical, infrastructure, policy, and soft measures to improve performance and cost-effectiveness. It aims to meet the basic mobility needs of all users. The SUMP concept emphasizes aspects of participatory planning, vertical and horizontal integration, and mechanisms for monitoring, evaluation and quality control.
See also
Sustainability
Sustainable transport
Transportation planning
Alternatives to car use
Local transport plans
Sustainable city (includes a section on Transportation)
Participatory planning
Complete streets
Bicycle-friendly
Walkability
Road traffic safety
External links
EC urban mobility
Eltis
Civitas
CH4LLENGE
References
Sustainable transport | Sustainable Urban Mobility Plan | [
"Physics"
] | 763 | [
"Physical systems",
"Transport",
"Sustainable transport"
] |
51,484,404 | https://en.wikipedia.org/wiki/Meizu%20MX4%20Ubuntu%20Edition | The Meizu MX4 Ubuntu Edition is a smartphone designed and produced by the Chinese manufacturer Meizu, which runs on Ubuntu Touch. It is a previous phablet model of the MX series, representing an alternative edition of the MX4. It is Meizu's first commercially available Ubuntu Touch device and the second commercially available phone with Ubuntu Touch overall. It was unveiled at the Mobile World Congress in March 2015.
History
In November 2014, Meizu and Canonical signed a cooperation agreement, which set the starting point for Meizu to release devices running on Ubuntu Touch.
In February 2015, Meizu confirmed that there will be an Ubuntu Touch-based version of the Meizu MX4 and that it will be showcased at Mobile World Congress 2015.
At the Mobile World Congress in March 2015, Meizu has presented the Meizu MX4 Ubuntu Edition, which is an alternative version of the MX4 running on Ubuntu Touch, becoming the second commercially available device on this platform.
Release
The Meizu MX4 Ubuntu Edition was released through an invite-only system on the European market on June 25, 2015.
Features
Ubuntu Touch
The MX4 Ubuntu Edition is running Ubuntu Touch, which is a mobile operating system based on the Ubuntu linux distribution developed by Canonical. Its goal is to provide a free and open-source mobile operating system and deliver a different approach to user experience by focusing on so-called “scopes” instead of traditional apps.
Hardware and design
The technical specifications and outer appearance of the MX4 Ubuntu Edition is identical with the Meizu MX4. The Meizu MX4 Ubuntu Edition features a MediaTek MT6595 system-on-a-chip with an array of four ARM Cortex-A17 and four Cortex-A7 CPU cores, a PowerVR G6200 GPU and 3 GB of RAM.
The MX4 Ubuntu Edition is only available in with 16 GB of internal storage and with a champagne gold body.
The body of the MX4 Ubuntu Edition features a metal frame and measures x x and weighs . It has a slate form factor, being rectangular with rounded corners.
The MX4 Ubuntu Edition features a 5.36-inch AMOLED multi-touch capacitive touchscreen display with a FHD resolution of 1152 by 1920 pixels. The pixel density of the display is 403 ppi.
In addition to the touchscreen input and the front key, the device has volume/zoom control buttons and the power/lock button on the right side, a 3.5mm TRS audio jack on the top and a microUSB (Micro-B type) port on the bottom for charging and connectivity.
The Meizu MX4 Ubuntu Edition has two cameras. The rear camera has a resolution of 20.7 MP, a ƒ/2.2 aperture, a 5-element lens, laser-aided phase-detection autofocus and an LED flash. The front camera has a resolution of 2 MP, a ƒ/2.0 aperture and a 4-element lens.
Reception
The MX4 Ubuntu Edition received generally positive reviews.
ZDNet gave the MX4 a rating of 8.0 out of 10 possible points and mentioned that “the Meizu MX4 Ubuntu Edition offers a number of high-end hardware features at relatively low cost”.
TechRadar stated that “Ubuntu Phone has plenty of potential” and praised the build quality, design and powerful specifications of the device.
See also
Meizu
Meizu MX4
Meizu PRO 5 Ubuntu Edition
Comparison of smartphones
References
External links
Official product page Meizu
Official product page Ubuntu
Ubuntu Touch devices
Mobile phones introduced in 2015
Meizu smartphones
Mobile phones with 4K video recording
Discontinued flagship smartphones | Meizu MX4 Ubuntu Edition | [
"Technology"
] | 815 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
51,484,732 | https://en.wikipedia.org/wiki/Catalan%20Institute%20of%20Nanoscience%20and%20Nanotechnology | The Catalan Institute of Nanoscience and Nanotechnology (ICN2) is a Spanish foundation for interdisciplinary research in nanoscience and nanotechnology. Located on the campus of the Autonomous University of Barcelona (UAB), the institute also offers education programs, training to researchers and services to industry and the scientific community. It is integrated in the research centers organization of the Generalitat de Catalunya (CERCA).
The institute is governed by a Board of Trustees, formed by: the Generalitat de Catalunya, the Consejo Superior de Investigaciones Científicas (CSIC) and the Universidad Autónoma de Barcelona (UAB). It has been a Severo Ochoa center of excellence in 2014 and 2018.
History
The ICN2 was founded in 2003 as "Instituto Catalán de Nanotecnología" (ICN). In 2006 began the collaboration with the Consejo Superior de Investigaciones Científicas (CSIC). It was then that the Catalan Institute of Nanoscience and Nanotechnology (ICN2) was created. Since 2012 the center has been managed by Pablo Ordejón.
In 2011 CSIC members joined the ICN's board of trustees. In 2013 the ICN adopted its current name, Catalan Institute of Nanoscience and Nanotechnology (ICN2). A new headquarters was built on the UAB campus and the building was inaugurated in 2014.
Research
Research at the ICN2 is carried out by the following multi-disciplinary research groups:
The ICN2 has a Research Support Division with three units: instrumentation, electron microscopy, nanomaterials growth.
It has runs training programs for researchers in nanotechnology including studentships, doctoral and post-doctoral positions. It also provides custom training courses for technicians, R&D personnel and administrative personnel.
The Institute promotes the commercial exploitation and dissemination of the results of its research, through collaboration with local and international companies. l. The institute is also involved in spinoff companies and provides a range of facilities and services to support research and innovation carried out by its partners.
Organization & Leadership
The ICN2 is led by its director, Prof. Pablo Ordejón,
Research is led by 18 group leaders.The ICN2's strategic research programs are reviewed and evaluated by an independent Scientific Advisory Board (SAB) made up of international scientists with experience in nanoscience and nanotechnology from the public and private sectors.
Awards
In 2014, the ICN2 was accredited as a 'Severo Ochoa Centre of Excellence' by the Spanish Ministry of Economy and Competitiveness for the period 2014-2018, in recognition of the ICN2's international scientific impact, potential for attracting international talent and its contribution to the transfer and dissemination of knowledge to society. The award was renewed in 2018 for the 2018-2022 period.
Outreach
ICN2 participates in educational programs at school, such as NanoEduca, and in the community with seminars and workshops that bring scientists together with business people and politicians. Its research results are published in the media. They also organize discussion forums.
Scientific Output
During 2018, ICN2 researchers produced 172 indexed publications with an average impact factor of 8.86. Specifically, 136 of these articles were published in first-quartile journals, while 77 appeared in first-decile journals.
References
Nanotechnology institutions
International research institutes
Science and technology in Spain
Autonomous University of Barcelona
Scientific organisations based in Spain
Research institutes in Europe
Research institutes in Catalonia | Catalan Institute of Nanoscience and Nanotechnology | [
"Materials_science"
] | 727 | [
"Nanotechnology",
"Nanotechnology institutions"
] |
51,486,243 | https://en.wikipedia.org/wiki/Stone%20Village%20Historic%20District | The Stone Village Historic District encompasses a distinctive collection of stone buildings on Vermont Route 103 in Chester, Vermont, United States. Dating to the first half of the 19th century are a remarkable concentration of buildings constructed in a regionally distinctive snecked ashlar technique brought to the area by Scottish masons. The district was listed on the National Register of Historic Places in 1974.
Description and history
In the early 1830s, skilled masons from Scotland came to central Vermont to work on building projects there. A number of these, mainly from the Aberdeen area, were experienced in snecked ashlar construction, in which plates of stone are affixed to a rubblestone wall. This type of construction is generally rare in the United States, and is found on about 50 surviving buildings in the state of Vermont. The highest concentration of them is on the north side of Chester Depot village, lining Vermont Route 103, and is known locally as the Stone Village.
Two Scottish masons, brothers Alison and Wiley Clark, came to the town of Chester in 1832 to work on large factory building (now no longer standing). In 1834, Doctor Ptolmey Edson hired the brothers to build his house, which was the first snecked ashlar structure in the village. It was followed by a series of other buildings, most of which are residences. The church and district school were also built of stone, possibly due to the influence of Dr. Edson, who sat on their respective building committees. Most of the houses are either Cape-style houses of stories or two-story structures, in either case with some Greek Revival styling in the trim details. Thirteen of the seventeen buildings in the district are stone; the other four date to a similar time period (roughly 1830–50). One building, a large wood-frame tavern house at the northern end of the district, was destroyed by fire in 2012.
See also
National Register of Historic Places listings in Windsor County, Vermont
References
Historic districts on the National Register of Historic Places in Vermont
National Register of Historic Places in Windsor County, Vermont
Greek Revival architecture in Vermont
Historic districts in Windsor County, Vermont
Chester, Vermont
Scottish-American culture in Vermont
Stonemasonry | Stone Village Historic District | [
"Engineering"
] | 443 | [
"Construction",
"Stonemasonry"
] |
51,486,292 | https://en.wikipedia.org/wiki/Sony%20Xperia%20XZ | The Sony Xperia XZ is an Android smartphone manufactured and marketed by Sony. Part of the Xperia X series, the device was announced to the public along with the Xperia X Compact at a press conference held at the annual IFA event on September 1, 2016. The Xperia XZ was first released in Taiwan on September 30, 2016, with worldwide sales starting with the United Arab Emirates on October 1 and the United States the following day; its home country Japan only started sales on November 2, 2016.
The device is described by Expert Reviews as the "true successor" of the Xperia Z5 and the whole Xperia Z series, and was succeeded Xperia Z5 Premium and Xperia X Performance as Sony's flagship. It is succeeded by the Xperia XZs and the flagship Sony Xperia XZ Premium.
It is also one of the first smartphones manufactured by Sony to utilize USB-C connectivity for charging and data transfer. Compared to its predecessors, the rear camera of the Xperia XZ now has laser autofocus, a first for Sony, built-in alongside the hybrid contrast/phase detection autofocus also found on the previous flagship. It also the first Sony device to sport an RGBC-IR color sensor to assist the image sensor in capturing accurate colors, temperature and white balance and the first smartphone to feature a five-axis digital image stabilization system for capturing blur-free photos and videos. The phone also has an IP68 rating, with it being dust and water resistant.
Specifications
Hardware
The Xperia XZ's design consists of 3 different materials that seamlessly blend together in what Sony calls "Loop Surface": a nylon frame, scratch-resistant front glass and an aluminium alloy metal back. The rear cover of the device is made from an aluminium alloy marketed as ALKALEIDO, a trademark by Kobe Steel, specifically engineered to complement the smartphone's premium design with a material "that has an extra shine and a feeling of depth". The device's front side is covered in Gorilla Glass to protect it from scratches and high drops. Also up front are dual front-firing stereo speakers, one on top along with the front selfie camera, ambient light and proximity sensors and notification LED, and the other one at the bottom bezel.
The Xperia XZ's dimensions are in height, with a width of and a depth of and weighs approximately . The device brings back the 1080p IPS LCD display with a pixel density of 424 ppi that started with the Xperia Z2 but with a brand new panel, featuring Sony's TRILUMINOS™ display and X-Reality for mobile technology. It is powered by a quad-core Qualcomm Snapdragon 820 (MSM8996) chipset with 4 custom Kryo processors (2 × 2.15 GHz and 2 × 1.6 GHz), 3 GB of RAM and relies on the Adreno 530 clocked at 624 MHz for graphics rendering. The device also has an internal storage of 32 GB for the single-SIM variant and 64 GB for the dual-SIM variant, both with microSD card expansions up to 256 GB (in a hybrid slot for the dual-SIM variant).
The Xperia XZ antennas support up to a maximum of LTE Category 9 speeds with a maximum theoretical downlink speed of 450-500 Mbit/s using 3CA, excluding the SOV34 model whose maximum theoretical downlink 3CA speed is limited to maximum 370 Mbit/s.
Connectivity and Features
Unlike some recently released smartphones from competing brands, the Xperia XZ doesn't abandon the standard 3.5 mm audio jack in favor of wireless substitutes. It does, however, have LDAC, an audio coding technology developed by Sony, that enables the transmission of 24bit/96 kHz High-Resolution (Hi-Res) audio content over Bluetooth at up to 990 kbit/s, three times faster than conventional audio streaming codecs, to compatible audio devices. It also has the standard set of connectivity options like Bluetooth 4.2 LE with aptX, NFC, dual-band Wi-Fi with Wi-Fi Direct, DLNA and hotspot, GPS and A-GPS, GLONASS and BDS. Like its predecessors, it has an IP rating of IP68, making the Xperia XZ dust proof and water resistant for over 1.5 meters and 30 minutes under water. The device also feature a fingerprint sensor embedded into the power button that can be used to unlock the phone and secure it from unauthorized access. This feature is disabled by default in the US.
Battery
The Xperia XZ is powered by a non-removable 2900 mAh battery, with a USB-C connector for charging and data transfer, one of the first two Sony smartphones to have one, the other one being the Xperia X Compact. It has QuickCharge 3.0 support and Qnovo adaptive charging technology built-in. This allows the device to monitor the cell's electrochemical processes in real time and adjust charging parameters accordingly to minimize cell damage and extend the battery cell's lifespan. It also comes with Battery Care, a Sony proprietary feature, that controls the charging process of the phone by learning and recognizing the user's charging patterns, preventing the phone from damaging the battery's cells from excessive heat due to overcharging. For example, when charging overnight, Battery Care stops the initial charge to 90 percent and then continue charging until full where it left off the next day.
Camera
The rear camera of the Xperia XZ features a new multi-aspect 24.8 MP Sony Exmor RS image sensor, officially named as Sony IMX300. Similar to the Xperia Z5 series, the Xperia X and Xperia X Performance, it has 23 megapixels with a sensor size of 1/2.3 inch and a f/2.0 aperture. Sony introduces the Triple Image Sensing technology with the Xperia XZ, comprised by the Image sensing (CMOS sensor with PDAF), Distance sensing (Laser AF sensor) and Color sensing (RGBC-IR sensor) systems. It features a hybrid autofocus that utilizes phase detection to lock focus on a subject within 0.03 seconds, also same with the Xperia Z5. It also includes phase and contrast detection along with predictive motion tracking, both working together to adjust the right amount of contrast accurately and significantly reduce blur and image shift caused by shaky hands.
The Xperia XZ, for the first time, includes a laser autofocus sensor alongside the hybrid/PDAF in tracking and locking focus on an object faster than regular autofocus modes, and an RGBC-IR (RedGreenBlueClear-InfraRed) color sensor that assists the white balance function of the camera by providing additional data about the light conditions of the environment, thus improving the color accuracy of the image. It also has an upgraded SteadyShot with Intelligent Auto in addition to the 5-axis image stabilization. The front selfie camera has a 13-megapixel sensor with 22 mm and 90-degree wide-angle lens, making it the highest-resolution front-facer on a flagship Sony device.
The device also has 4K resolution video recording capabilities like the Xperia Z5. Similar to the Sony α7 II camera, the Xperia XZ features five-axis digital image stabilization, a first for a smartphone, that helps in producing smooth video with less camera shake and improved image quality in low light environments. This technology improves the image and video produced by detecting camera shake, such as angular motion consisting of pitch and yaw, shift shakes which consists of X and Y axis shifts and (rotational shake) by correcting the effects detected, shifting the lens to reduce visible image blur and shift shake.
Software
The Sony Xperia XZ launches with Android 6.0 Marshmallow out of the box, with Sony's custom interface and software. On December 1, 2016, along with the Xperia X Performance and a few other Xperia devices, Sony announced that the Xperia XZ would receive an update to Android 7.0 Nougat. Just a day after, the Android 7.0 update has officially rolled out.
References
External links
Official white paper
Official white paper (Dual SIM)
Android (operating system) devices
Discontinued flagship smartphones
Sony smartphones
Mobile phones introduced in 2016
Mobile phones with 4K video recording | Sony Xperia XZ | [
"Technology"
] | 1,748 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
51,487,006 | https://en.wikipedia.org/wiki/Chemistry%20of%20wetland%20dredging | Wetland chemistry is largely affected by dredging, which can be done for a variety of purposes. Wetlands are areas within floodplains with both terrestrial and aquatic characteristics, including marshes, swamps, bogs, and others. It has been estimated that they occupy around 2.8x106 km2, about 2.2% of the Earth’s surface, but other estimates are even higher. It has also been estimated to have a worth of $14.9 trillion and are responsible for 75% of commercial and 90% of recreational harvest of fish and shellfish in the United States. Wetlands also hold an important role in water purification, storm protection, industry, travel, research, education, and tourism. Being heavily used and traveled through, dredging is common and leads to continuation of long-term damage of the ecosystem and land loss, and ultimately a loss in industry, homes, and protection.
Wetlands undergo different chemical reactions depending on a variety of parameters, including salinity and pH. Redox reactions have a major effect on wetland ecosystems, as they depend heavily on salinity, pH, oxygen availability, and others. Common redox reactions in wetland include carbon, nitrogen, and sulfur transformations. Fluctuations in water flow and flooding can change the abundance of the oxidized or reduced species depending on the environment. Increased flooding and water flow can also change the availability of nutrients to local species. The further the wetlands change from their original states, the more difficult rebuilding land becomes. The types of mitigation efforts also change depending on the chemistry, so an understanding of the change is required for effective mitigation.
Wetlands
Definition
Wetlands are areas of land submerged in water near both terrestrial and aquatic systems. They are highly diverse and are classified by the United States Fish and Wildlife Service into five categories: "The term wetland includes a variety of areas that fall into one of five categories: (1) areas with hydrophytes and hydric soils, such as those commonly known as marshes, swamps, and bogs; (2) areas without hydrophytes but with hydric soils - for example, flats where drastic fluctuation in water level, wave action, turbidity, or high concentration of salts may prevent the growth of hydrophytes; (3) areas with hydrophytes but nonhydric soils, such as margins of impoundments or excavations where hydrophytes have become established but hydric soils have not yet developed; (4) areas without soils but with hydrophytes such as the seaweed-covered portion of rocky shores; and (5) wetlands without soil and without hydrophytes, such as gravel beaches or rocky shores without vegetation".
Wetlands can also be classified based on salinity, a type of classification often referenced in research where salinity is a major factor. These classifications are often referred to in parts per thousand (ppt) and include freshwater (0–2 ppt), intermediate (2–10 ppt), brackish (10–20 ppt), and saltwater (20+ ppt).
Importance of wetlands
Wetlands are sources of extreme biodiversity and ecological benefit. They contain a multitude of species of plants and animals, including 79 species classified as rare, threatened, or endangered. An estimate by the U.S. Fish and Wildlife Service indicates that wetlands provide for, directly and indirectly, up to 43% of federally threatened or endangered species. Wetlands are the leading producer of oysters, 50% of the shrimp crop, 75% of the alligator harvest, 27% of the oil and gas, and the largest port complex in the United States. The world’s wetlands have an estimated worth of $14.9 trillion.
Wetlands also provide for disaster protection, including surge protection from hurricanes, as they and barrier islands help to break down the power of a storm before it reaches mainland. They also provide flood relief, as they are able to hold about three-acre feet (one million gallons) of water. This holding of water allows for rejuvenation of ecosystems, as new sediment is able to settle. Flooding also affects factors such as root penetration, soil temperature, conductivity, and bulk density.
Wetlands are highly effective at removing pollutants and excess nutrients due to the slow water flow and absorption by the plant systems. This has been shown to be effective in the removal of nitrogen and phosphorus, the major nutrients involved in "dead zones". They are also major sinks for heavy metals and sulfur.
Dredging
Dredging is the removal of sediment, plant species, and debris from an aquatic area. Industry, travel, and recreation throughout wetlands often requires the dredging of canals, especially by oil industry to get out to their offshore drills through coastal wetlands. Canals widen after being dredged because of the increased water flow and loss of plant life, both attributing to increased erosion. It is estimated that there are of canals south of the Intracoastal Waterway, not including Lake Pontchartrain and Lake Maurepas, and that canals alone attribute to of land loss per year in the United States. The permits required to dredge these canals include stipulations of refilling, but these are not often enforced. John M. Barry, along with a group of private lawyers and coastal experts, filed a lawsuit in 2013 against 97 corporations who had violated their permits in Louisiana’s coastal wetlands in response to this. It is referred to as "the most ambitious environmental lawsuit ever" by the New York Times and has been met with political resistance.
Wetland dredging chemistry
Wetlands are dynamic systems that undergo a variety of chemical reactions depending greatly on the specific physicochemical properties of the area, such as temperature, pressure, dissolved organic matter, pH, salinity, and dissolved gases (CO2 and O2). The qualities that have the largest effect are salinity and pH. An increase in flooding (a result of dredging) increases the salinity of wetlands, as it allows saltwater to intrude, neutralizes the pH, and provides more anaerobic soil conditions. The conditions then effect the nutrient availability and redox reactions.
Redox reactions
Redox reactions are highly influential in wetland soil chemistry through transformations including those of carbon, sulfur, nitrogen. The abundance of oxygen changes the abundance of oxidized or reduced states of each compound. Areas of higher oxygen availability (aerobic) tend towards oxidized states and areas of low oxygen availability (anaerobic) tend towards reduced states. The abundance of each type results in a different ecosystem, as the plants and animals of the wetlands require specific conditions for their growth. Common wetland redox reactions include:
2NO3− +10e− +12H+ → N2 +6H2O
SO4 +8e− +9H+ → HS− +4H2O
CO2 +8e− +8H+ → CH4 + 2H2O
MnO2 +2e− +4H+ → Mn2+ + 2H2O
Fe(OH)3 +e− +3H+ → Fe3+ + 3H2O
Dredging allows for an increased flow of water through wetlands, causing anaerobic soil conditions. This change in wetland type results in a change in redox state for each reaction undergone and thus changes the plant species available to grow in those areas. The redox potential (Eh) can help to show the relationship of the redox reactions through the Nernst equation:
Eh=E0-(RT/nF)ln([Reductants]a/[Oxidants]b[H+]b)
This equation allows for the calculation of the extent of reaction between two redox systems and can be used, for example, to decide whether a particular reaction will go to completion or not.
An example of a change in these circumstances affecting the wetland system is in the transformation of pyrite (FeS2) through the reduction of SO42− (found in seawater).
Fe(OH)3 + e− + H+ → Fe(OH)2 + H2O
SO42− + 6e− + 8H+ → S + 4H2O
S + 2e− + 2H+ → H2S
Fe(OH)2 + H2S → FeS + 2H2O
FeS + S → FeS2 (pyrite)
The drainage of the resulted pyrite then results in oxidation to ferric hydroxide and sulfuric acid, causing extreme acidity (pH < 2).
Nutrient availability
Increased flooding also allows for saltwater intrusion, changing the salinity levels and killing off species of plants that normally grew and changing available nutrient, chemical, and oxygen levels as well. An increase in salinity leads to higher sulfate concentrations and higher sulfide emissions, and higher toxicity. It also results in a reduction of sulfur availability to plant species as it precipitates with trace metals such as zinc and copper. An example of this is ferrous sulfide (FeS), which gives wetland soils their black color and is the source of sulfur commonly found in coal deposits.
Flooding also results in pH neutralization of generally acidic (with exceptions) wetlands. Acidic wetlands inhibit denitrification, thus flooding allows denitrification to occur, resulting in a loss of gaseous nitrogen forms to the atmosphere. The reaction is shown below:
5C6H12O6 +24NO3− +24H+ → 30CO2 +12N2 +42H2O
Anaerobic soil conditions brought on by flooding allows for precipitation of phosphates with ferric iron and aluminum (acidic soils) or calcium and magnesium (basic soils) resulting in phosphorus being unavailable for uptake in plant species.
Importance of wetland chemistry
As the environment is altered through physical means (dredging), the occurring reactions change resulting in a decrease of the availability of nutrients and chemical species to plant species and the ecosystem. This then further changes the physical environment as these species are no longer able to survive. The loss of species then results in further changes to the chemical environment, as they are no longer present to remove excess nutrients. This also changes the physical environment further as the lack of survival of plant species results in open land and increased erosion. The change of the chemical environment also affects the mitigation techniques to be applied for rebuilding of wetlands as the survival of plant species that could potentially be planted depends on the chemical environment, and changes must be monitored for effective mitigation to take place.
References
Geochemistry
Wetlands
Dredging | Chemistry of wetland dredging | [
"Chemistry",
"Environmental_science"
] | 2,171 | [
"Hydrology",
"Wetlands",
"nan"
] |
51,487,086 | https://en.wikipedia.org/wiki/Cattle%20urine%20patches | Urine patches in cattle pastures generate large concentrations of the greenhouse gas nitrous oxide through nitrification and denitrification processes in urine-contaminated soils. Over the past few decades, the cattle population has increased more rapidly than the human population. Between the years 2000 and 2050, the cattle population is expected to increase from 1.5 billion to 2.6 billion. When large populations of cattle are packed into pastures, excessive amounts of urine soak into soils. This increases the rate at which nitrification and denitrification occur and produce nitrous oxide. Currently, nitrous oxide is one of the single most important ozone-depleting emissions and is expected to remain the largest throughout the 21st century.
Nitrous oxide environmental impacts
Nitrous oxide is a greenhouse gas with a global warming potential 298 times that of carbon dioxide. Global warming potential is a way to compare global warming impacts of different gases relative to carbon dioxide emissions. Since nitrous oxide has such a high global warming potential, it is able to warm the earth more effectively compared to other greenhouse gases. Although generally unreactive in the troposphere, nitrous oxide is destroyed during photolysis or reactions with excited oxygen atoms and catalyzes the destruction of ozone in the stratosphere. The net loss of ozone molecules occurs in a series of photochemical reactions represented below:
Destruction of stratospheric ozone leaves the biosphere vulnerable to penetrating rays of ultraviolet radiation. Exposure to high amounts of ultraviolet radiation can affect the environment by affecting productivity of crops the human population depends on for food.
Cattle urine composition
Nitrogen concentration of cattle urine varies between approximately 3.0 and 10.5 g/L. Although many nitrogenous constituents are involved in the chemical make-up of cattle urine, urea is dominant. Urea concentration represents 52.0% to 93.5% of total urinary nitrogen and is dependent upon the amount of dietary protein consumed by cattle. Through a process known as ureolysis, the enzyme urease completely hydrolyzes urea to ammonia within one to two days of being excreted and soaked into soils. This reaction is outlined below:
(NH2)2CO + 2H2O -> NH3 + NH4+ + HCO3-
Ammonia is the key product of this reaction that goes on to fuel nitrification.
The role of the nitrogen cycle in urine-contaminated soils
Nitrification and denitrification are two microbial processes that are part of the nitrogen cycle. While denitrification contributes to the bulk production of nitrous oxide, small amounts are also produced during nitrification. When specific environmental factors are met, both processes will occur more quickly and produce higher emissions of nitrous oxide. For example, soils with relatively high temperatures and water-filled pore spaces ranging from 60 to 80% are required for peak performances of both processes.
Nitrification
Nitrification will occur once ammonia becomes readily available in urine-contaminated soils. Ammonia is oxidized into nitrite and nitrate via nitrifying bacteria. Nitrification is chemically-expressed in two distinct steps as shown below:
Step 1
Step 1 details the oxidation of ammonia into nitrite via ammonia-oxidizing bacteria. The most frequent genus of bacteria identified as being the facilitator of this step is Nitrosomonas. These bacteria will produce small quantities of nitrous oxide from produced nitrite in a side reaction. Nitrous oxide emissions increase as soil pH concentration increases or becomes more basic.
NH3 + O2 -> NO2- + 3H+ + 2e-
Step 2
Step 2 details the oxidation of nitrite to nitrate via nitrite-oxidizing bacteria. The most frequent genus of bacteria identified as being the facilitator of this step is Nitrobacter. While no quantities of nitrous oxide are produced in this step, the resulting nitrate is used to fuel denitrification.
NO2- + H2O -> NO3- + 2H+ +2e-
Denitrification
Denitrification is the process that produces the most nitrous oxide. Denitrification involves the reduction of nitrites and nitrates produced during nitrification into nitrous oxide by denitrifying bacteria. Nitrous oxide is subsequently reduced to dinitrogen, the key product of the nitrogen cycle. Nitrous oxide is merely a free obligatory intermediate and is not a major product. Different strains of denitrifying bacteria utilize unique pathways in order to perform denitrification. While these pathways differ from each other, the substrates and products of this process remain the same. Below are two proposed schemes carried out by common denitrifying bacteria:
Scheme 1
NO2^- -> \underset{\overset{\displaystyle \uparrow}{\displaystyle NO}}{N2O} -> N_2
Scheme 1 details the denitrification process by Paracoccus denitrificans and Pseudomonas aeruginosa denitrifying bacteria.
Scheme 2
Scheme 2 represents the denitrification process by Pseudomonas stutzeri. In the above formula, (X) represents a common mononitrogen intermediate such as nitrogen monoxide.
Efforts to lessen environmental impacts
Research suggests lessening the concentrations of nitrous oxide entering the stratosphere will serve to enhance recovery of the damaged stratospheric ozone layer.
Biochar
The incorporation of biochar into soil has been investigated to reduce nitrous oxide emissions from ruminant urine patches. Biochar is a carbon-rich compound manufactured from the thermal decomposition of organic matter in oxygen-deprived conditions at relatively low temperatures. Biochar serves to reduce nitrous oxide emissions by altering nitrogen transformation rates in urine-contaminated soils. Detailed field data such as seasonal effects and repeated soil exposure are still lacking and research on this subject is ongoing. However, nitrous oxide emissions have been demonstrated as being reduced by 50 and 80% following the incorporation of biochar into affected soils.
Organic agriculture
Organic agriculture has shown decreased nitrous oxide emissions through limiting the number of cattle present per hectare of pasture. A decreased number of cattle in one hectare leads to less nitrogenous constituents deposited into the soil at one time and strains the occurrence of nitrification and denitrification. This in turn limits the total amount of nitrous oxide that can be produced.
References
Cattle pastures
Cattle
Agricultural land | Cattle urine patches | [
"Biology"
] | 1,343 | [
"Urine",
"Excretion",
"Animal waste products"
] |
51,487,091 | https://en.wikipedia.org/wiki/Adsorbable%20organic%20halides | Adsorbable organic halides (AOX) is a measure of the organic halogen load at a sampling site such as soil from a land fill, water, or sewage waste. The procedure measures chlorine, bromine, and iodine as equivalent halogens, but does not measure fluorine levels in the sample.
Background
Utilization of halogen containing materials in processes such as water treatment, bleaching, or even general synthesis to create the final product, generates a number of organic halides. These organic halides are released in wastewater from the oil, chemical, and paper industries, and find their way to the consumer and eventually to a landfill or oceanic dumps. Within the soil, the halo compounds resist degradation and often react with metal ions, resulting in non-degradable metal complexes, increasing soil toxicity and accumulating in the food chain of aquatic organisms. Up to 2000 ppm of these bio-accumulative organic chlorides were detected in fat of fish from the waters where bleaching effluents were disposed by paper mills, where a 2% water concentration is considered toxic for the fish. While strict regulations from the government have reduced the high level of past emissions, these compounds find their way to water sources through improper consumer disposal of items that contain chlorinated compounds. The presence of any organic halides in natural water has been considered an indication of contamination with xenobiotics. Once in water, the naturally occurring fulvic acids and humic acids can lead to formation of mutagenic compounds such as halogenated furanone MX (Z-3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone). Consumption of these mutagenic compounds could cause several abnormalities in development and reproduction in humans through long half-lives and mimicking hormone receptors. For example, compounds like dioxins can inhibit the actions of sex hormones by binding to steroid receptors along with causing long lasting cell disruption in several tissues.
Determination
Persistent organic pollutants such as dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenols, dioxins, are all assessed in AOX analysis. Generally, the higher the amount of chlorine in an organic compound, the more toxic it is considered. While there are several biochemical or electrochemical methods to remove organic halides, AOX has been preferred due to its low cost of operation and simplicity of design.
In a lab, the determination of AOX parameter consists of adsorption of organic halides from the sample on to an activated carbon. The activated carbon can be powdered or granular and adsorbed using microcolumns or a batch process, if the samples are rich in humic acids. Vigorous shaking is often employed in the event of a batch process to favor the adsorption of organic halide on to the activated carbon due to its electronegativity and presence of lone pairs. The inorganic halides that are also adsorbed are washed away using a strong acid such as nitric acid. The carbon with adsorbed organic halide is obtained by filtration, after which the filter containing the carbon is burnt in the presence of oxygen. While combustion of hydrocarbon part of the compounds form CO2 and H2O, halo acids are formed from the halogens. These haloacids are absorbed into acetic acid. Subsequent use of microcolumetric titration, an electrochemical quantification method, provides the AOX content in the sample. Using the dilution ratio, the total AOX content at the location can be estimated. Alternatively, the chlorinated compounds in the sample can be determined by using pentane extraction followed by capillary gas chromatography and electron capture (GC-ECD). The organic carbon that was remaining after the nitric acid purge can be analyzed using UV-persulfate wet oxidation followed by Infrared-detection (IR). Several other analytical techniques such as high performance liquid chromatography (HPLC) could also be implemented to quantify AOX levels. The general adsorption procedure is given below:
Where is the activated carbon and is any organic halide.
is the organic halide - activated carbon complex that can be filtered out.
Treatment
Physical separation
In water treatment plants, organic halides are adsorbed using GAC or PAC in agitated tanks. The loaded carbon is separated using a membrane made out of materials like polypropylene or cellulose nitrate. Measuring the AOX levels into and out of the treatment zone shows a drop in organic halide concentrations. Some processes use a two-step GAC filtration to remove AOX precursors, and thus reduce the amount of AOX in treated waters. A two step filtration process consists of two GAC filters in series. The first filter is loaded with exhausted GAC, while the second filter is loaded with fresh GAC. This set up is preferred for its increased efficiency and higher throughput capacity. The GAC is replaced cyclically and the extracted organic halide-carbon mixture is then sent for subsequent biological or chemical treatment such as ozonation to regenerate the GAC. Often, these chemical treatments, while effective, pose economical challenges to the treatment plants.
Biological treatment
A more economically attractive option for treatment of the organic halides is through utilization of biological agents. Recently, bacteria (Ancylobacter aquaticus), fungi (Phanerochaete chrysosporium and Coiriolus versicolor), or synthetic enzymes have been used in the degradation of chlorinated organic compounds. The microorganisms degrade halocompounds using either aerobic or anaerobic processes. The mechanisms of degradation include utilization of the compound as carbon source for energy, cometabolite, or as an electron acceptor. Note that enzymatic or microbial action could be regulated through feedback inhibition-the final product in the series inhibits a reaction in the process. An example of a microbe that can degrade AOX is shown below in Figures 1 and 2.
A sample dechlorination of chlorinated aliphatic hydrocarbons (CAHs) such as perchloroethylene (PCE) by Dehalococcoides ethenogenes has been illustrated above. PCE is one of the highly chlorinated CAHs with no known microorganisms capable of aerobic degradation. The high electronegative character of PCE renders oxidizing agent capabilities through accepting electrons by co-metabolism or dehalorespiration. In a co-metabolism, the reduction of PCE is made feasible by the utilization of a primary metabolite for carbon and energy source. In dehalorespiration, the electron transfer from oxidation of small molecules (H2 is the major source; but, glucose, acetate, formate, and methanol can also be used) to PCE generates energy required for the bacterial growth. The hydrogen involved in this mechanism is often a product of another process such as fermentation of simple molecules like sugars or other complex molecules like fatty acids. Moreover, due to competition from methanogens for H2, low H2 concentrations are favored by dechlorinating bacteria, and is often established through slow-release fermentation compounds such as fatty acids and decaying bacterial biomass. While several enzymes and electron carriers are involved in process, two enzymes perform the dechlorination reactions–PCE reductive dehydrogenase (PCE-RDase) and TCE reductive dehydrogenase (TCE-RDase). The PCE-RDase is normally found freely in cytoplasm while the TCE-RDase is found attached to the exterior cytoplasmic membrane. These enzymes normally utilize a metal ion cluster like Fe-S cluster to complete electron transfer cycle. Hydrogen is oxidized to generate two protons and two electrons. The removal of first chloride, which is performed by PCE-RDase, reduces PCE into TCE by reductive dehalogenation, where a hydride replaces the chlorine. The chloride lost from PCE gains the two electrons and the proton that accompanies them to form HCl. TCE can be reduced to cis-dichloroethene (cis-DCE) by either PCE-RDase or TCE-RDase. Subsequent reductions to vinyl chloride (VC) and ethylene are performed by TCE-RDase. The dechlorination of PCE to cis-DCE is faster and thermodynamically more favorable than dechlorination of cis-DCE to VC. The transformation of VC to ethylene is the slowest step of the process and hence limits the overall rate of the reaction. The rate of reductive dechlorination is also directly correlated with the number of chlorine atoms, and as such, it decreases with a decreasing number of chlorine atoms. In addition, while several groups of bacteria such as Desulfomonile, Dehalobacter, Desulfuromonas...etc. can perform the dehalogenation of PCE to TCE, only the Dehalococcoides group can perform the complete reductive dechlorination from PCE to ethene.
In addition to dechlorination of CAHs, microbes have also been reported to act on chlorinated aromatic hydrocarbons. An example of a reaction where aromatic AOX content has been reduced is demonstrated in figure 2 above. While little is known about the dehalogenation mechanisms of polyhalogenated phenols (PHPs) and polyhalogenated benzenes (PHBs), regioselectivity for halide location on the aromatic ring was observed. This regioselectivity is however dominated by both redox potentials for the reaction and the microbe's familiarity to the reaction. Moreover, due to the specificity of most microbes along with complex aromatic structures, in order to achieve a complete dehalogenation, a mixture of more than one species of bacteria and/or fungi (often known as a consortium) is utilized. The reaction in figure 2 shows the reductive debromination of 2,4,6-tribromophenol (2,4,6-TBP) by Ochrabactrum. Based on the relative degradation of the molecule along with analytical results, it has been postulated that degradation of 2,4,6-TBP proceeds through debromination of ortho-bromine in the first step by a dehalogenase to yield 2,4-dibromophenol (2,4-DBP). Since there are two ortho bromines, debromination of either ortho carbons would yield the same product . Other species such as Pseudomonas galthei or Azotobacter sp. showed preference for para-halide over the meta- or ortho -halides. For example, the Azotobacter sp. degrades 2,4,6-trichlorophenol (2,4,6-TCP) into 2,6-dichlorohydroquinone due to TCP-4-monooxygenase selectivity differences between ortho- and para-halide. These differences in regioselectivity between the species can be attributed to the specificity of the 3-dimensional enzyme structure and its hindrance from steric interactions. It has been postulated that a proton lost by the phenol group of 2,4,6-TBP resulting in the formation of a negatively charged halo-phenolate ion. Subsequent attack of the para-carbon with a hydride anion from NAD(P)H in a nucleophilic attack manner and resonance rearrangement results in substitution of bromine with hydride and formation of 2,4-DBP. Subsequent steps in a similar pattern yield 2-bromophenol, and phenol in the final step. Phenol can be metabolized by microorganisms to make methane and carbon dioxide or can be extracted easier than AOXs.
Related terms
Organic halides, extractable organic halides (EOX), and total organic halides (TOX) are related content for this topic. EOX provides information on how halides can be extracted using a solvent while TOX provides information about the total organic halide content in the sample. This value can be used to estimate biochemical oxygen demand (BOD) or chemical oxygen demand (COD), a key factor in estimating the required oxygen to burn the organic compounds to estimate the percentage of AOX’s and Extractable organic halides.
References
Environmental chemistry | Adsorbable organic halides | [
"Chemistry",
"Environmental_science"
] | 2,688 | [
"Environmental chemistry",
"nan"
] |
62,858,002 | https://en.wikipedia.org/wiki/Pamela%20E.%20Harris | Pamela Estephania Harris (born November 28, 1983) is a Mexican-American mathematician, educator and advocate for immigrants. She is currently a professor at the University of Wisconsin-Milwaukee in Milwaukee, Wisconsin, was formerly an associate professor at Williams College in Williamstown, Massachusetts and is co-founder of the online platform Lathisms. She is also an editor of the e-mentoring blog of the American Mathematical Society (AMS).
Early life and career
Harris first emigrated with her family from Mexico to the United States when she was 8 years old. They returned to Mexico, before eventually settling in Wisconsin when Harris was 12. Because she was undocumented, she could not attend university. Instead, she studied at the Milwaukee Area Technical College, where she earned two associate degrees in two and a half years. After she married a US citizen and her immigration status changed, she transferred to Marquette University, where she obtained a bachelor's degree in mathematics. She went on to complete her master's degree and in 2012 a PhD at the University of Wisconsin-Milwaukee. Her Ph.D. dissertation was advised by Jeb F. Willenbring. Harris was a Project NExT (New Experiences in Teaching) fellow in 2012. She was a Davies Research Fellow at the United States Military Academy, and, in 2016, joined the faculty at Williams College where she was an associate professor. In 2022, she joined the faculty at the University of Wisconsin-Milwaukee as an associate professor.
Harris studies algebraic combinatorics, in particular the representation of Lie algebras. In order to understand this representation she studies vector partition functions, in particular Kostant's partition function. She is also interested in graph theory and number theory. In 2016 she co-founded an online platform called 'Lathisms' which aims to promote the contributions of Latinxs and Hispanics in the Mathematical Sciences. In 2020 she co-authored the book "Asked and Answered: Dialogues On Advocating For Students of Color in Mathematics". Harris, along with Aris Winger, run a podcast, Mathematically Uncensored, through the Center for Minorities in the Mathematical Sciences. Starting in October 2020, they discussed current issues in mathematics that minorities encounter.
Recognition
In 2020, Harris was selected as part of the inaugural class of Karen EDGE Fellows. In 2019, Harris won the Mathematical Association of America Henry L. Alder Award for Distinguished Teaching by a Beginning College or University Mathematics Faculty Member, for her mentorship towards undergraduate research and for being a "fierce advocate for a diverse and inclusive mathematics community." She further received the early career Faculty Mentor Award from the Council of Undergraduate Research in the Mathematics and Computer Sciences Division. She was a 2022 winner of the Deborah and Franklin Haimo Awards for Distinguished College or University Teaching of Mathematics.
She gave one of the Mathematical Association of America Invited Addresses at the 2019 Joint Mathematics Meetings. In 2019 she was a featured speaker at the national conference of the Society for the Advancement of Chicanos/Hispanics and Native Americans in Science (SACNAS). She was named a Fellow of the American Mathematical Society, in the 2022 class of fellows, "for contributions to algebraic combinatorics, for mentorship of undergraduate researchers, and for contributions to a more equitable and inclusive mathematical community". In 2022 she will become a fellow of the Association for Women in Mathematics, "For exceptional leadership in establishing programs and mentoring networks that support, encourage, and advance women and underrepresented minorities in the mathematical sciences; and for contributions through public speaking that create positive systemic change in the culture and climate of the mathematics profession."
In 2018 Harris was featured in the book Power in Numbers: The Rebel Women of Mathematics.
References
External links
Personal webpage
Curriculum vitae
Meet a Mathematician! Video interview
21st-century American women mathematicians
21st-century Mexican educators
Mexican mathematicians
Mexican women mathematicians
Williams College faculty
University of Wisconsin–Milwaukee faculty
21st-century American mathematicians
Combinatorialists
1983 births
Living people
Marquette University alumni
University of Wisconsin–Milwaukee alumni
Mexican emigrants to the United States
Fellows of the American Mathematical Society
21st-century Mexican women educators
Mexican scientists | Pamela E. Harris | [
"Mathematics"
] | 836 | [
"Combinatorialists",
"Combinatorics"
] |
62,858,326 | https://en.wikipedia.org/wiki/Dichlorodiethyl%20sulfone | Dichlorodiethyl sulfone (or mustard sulfone) is an oxidation product of mustard gas. It has the formula (ClCH2CH2)2SO2. Although it is irritating to the eyes, it is not nearly as bad as mustard gas (dichlorodiethyl sulfide).
Structure
The all-trans arrangement is predicted by Hartree-Fock computational methods to be the most stable conformer.
Reactions
When refluxed with aqueous sodium hydroxide, oxygen replaces the chlorine, and an 1,4-oxathiane ring is formed, p-oxathiane-4,4-dioxide. When treated with sodium carbonate, a weaker base, bis-(hydroxyethyl)sulfone is the major product formed. In comparison the dehydrochlorination of the sulfoxide is much slower.
References
Sulfones
Organochlorides | Dichlorodiethyl sulfone | [
"Chemistry"
] | 193 | [
"Sulfones",
"Functional groups"
] |
62,858,445 | https://en.wikipedia.org/wiki/Serre%27s%20theorem%20on%20a%20semisimple%20Lie%20algebra | In abstract algebra, specifically the theory of Lie algebras, Serre's theorem states: given a (finite reduced) root system , there exists a finite-dimensional semisimple Lie algebra whose root system is the given .
Statement
The theorem states that: given a root system in a Euclidean space with an inner product , and a base of , the Lie algebra defined by (1) generators and (2) the relations
,
,
,
.
is a finite-dimensional semisimple Lie algebra with the Cartan subalgebra generated by 's and with the root system .
The square matrix is called the Cartan matrix. Thus, with this notion, the theorem states that, given a Cartan matrix A, there exists a unique (up to an isomorphism) finite-dimensional semisimple Lie algebra associated to . The construction of a semisimple Lie algebra from a Cartan matrix can be generalized by weakening the definition of a Cartan matrix. The (generally infinite-dimensional) Lie algebra associated to a generalized Cartan matrix is called a Kac–Moody algebra.
Sketch of proof
The proof here is taken from and .
Let and then let be the Lie algebra generated by (1) the generators and (2) the relations:
,
, ,
.
Let be the free vector space spanned by , V the free vector space with a basis and the tensor algebra over it. Consider the following representation of a Lie algebra:
given by: for ,
, inductively,
, inductively.
It is not trivial that this is indeed a well-defined representation and that has to be checked by hand. From this representation, one deduces the following properties: let (resp. ) the subalgebras of generated by the 's (resp. the 's).
(resp. ) is a free Lie algebra generated by the 's (resp. the 's).
As a vector space, .
where and, similarly, .
(root space decomposition) .
For each ideal of , one can easily show that is homogeneous with respect to the grading given by the root space decomposition; i.e., . It follows that the sum of ideals intersecting trivially, it itself intersects trivially. Let be the sum of all ideals intersecting trivially. Then there is a vector space decomposition: . In fact, it is a -module decomposition. Let
.
Then it contains a copy of , which is identified with and
where (resp. ) are the subalgebras generated by the images of 's (resp. the images of 's).
One then shows: (1) the derived algebra here is the same as in the lead, (2) it is finite-dimensional and semisimple and (3) .
References
Theorems about algebras
Lie algebras | Serre's theorem on a semisimple Lie algebra | [
"Mathematics"
] | 576 | [
"Algebra stubs",
"Algebra"
] |
62,858,962 | https://en.wikipedia.org/wiki/Shigeru%20Nakayama | Shigeru Nakayama (中山茂) (1928–2014) was a Japanese historian of science.
Life
Nakayama was born in 1928, in Amagasaki, and brought up there. He survived the Hiroshima atom bomb of 1945. He left Hiroshima Higher School in 1948, and graduated from Tokyo University with a degree in mathematical astronomy in 1951.
As a graduate student, Nakayama was a Fulbright scholar. He worked with Thomas Kuhn and then Joseph Needham. Besides those two scholars, he regarded Kiyosi Yabuuti (1906–2000) as one of his teachers. At Harvard in the late 1950s, he met fellow graduate student Nathan Sivin, with whom he worked for many decades.
Nakayama was on the staff of Tokyo University from 1960 to 1989. As Professor Emeritus, he was at Kanagawa University.
Nakayama died in Tokyo on Saturday 10 May 2014.
Works
Japanese Studies in the History of Astronomy (1962)
A History of Japanese Astronomy: Chinese Background and Western Impact (1969)
Characteristics of scientific development in Japan (1977)
Academic and scientific traditions in China, Japan, and the West (1984)
Science, Technology, and Society in Postwar Japan (1991)
A Social History of Science and Technology in Contemporary Japan: The Occupation Period, 1945-1952 (2001), with Kunio Goto and Hitoshi Yoshioka
A Social History of Science and Technology in Contemporary Japan: Road to Self-Reliance, 1952-1959 (2005), with Kunio Goto and Hitoshi Yoshioka
A Social History of Science and Technology in Contemporary Japan: Transformation period, 1970-1979 (2006)
The Orientation of Science and Technology: A Japanese View (2009)
Notes
1928 births
2014 deaths
20th-century Japanese historians
Historians of astronomy
Hibakusha
21st-century Japanese historians | Shigeru Nakayama | [
"Astronomy"
] | 370 | [
"People associated with astronomy",
"Historians of astronomy",
"History of astronomy"
] |
62,859,875 | https://en.wikipedia.org/wiki/Living%20building%20material | A living building material (LBM) is a material used in construction or industrial design that behaves in a way resembling a living organism. Examples include: self-mending biocement, self-replicating concrete replacement, and mycelium-based composites for construction and packaging. Artistic projects include building components and household items.
History
The development of living building materials began with research of methods for mineralizing concrete, that were inspired by coral mineralization. The use of microbiologically induced calcite precipitation (MICP) in concrete was pioneered by Adolphe et al. in 1990, as a method of applying a protective coating to building façades.
In 2007, "Greensulate", a mycelium-based building insulation material was introduced by Ecovative Design, a spin off of research conducted at the Rensselaer Polytechnic Institute. Mycelium composites were later developed for packaging, sound absorption, and structural building materials such as bricks.
In the United Kingdom, the Materials for Life (M4L) project was founded at Cardiff University in 2013 to "create a built environment and infrastructure which is a sustainable and resilient system comprising materials and structures that continually monitor, regulate, adapt and repair themselves without the need for external intervention." M4L led to the UK's first self-healing concrete trials. In 2017 the project expanded into a consortium led by the universities of Cardiff, Cambridge, Bath and Bradford, changing its name to Resilient Materials 4 Life (RM4L) and receiving funding from the Engineering and Physical Sciences Research Council. This consortium focuses on four aspects of material engineering: self-healing of cracks at multiple scales; self-healing of time-dependent and cycling loading damage; self-diagnosis and healing of chemical damage; and self-diagnosis and immunization against physical damage.
In 2016 the United States Department of Defense's Defense Advanced Research Projects Agency (DARPA) launched the Engineered Living Materials (ELM) program. The goal of this program is to "develop design tools and methods that enable the engineering of structural features into cellular systems that function as living materials, thereby opening up a new design space for building technology... [and] to validate these new methods through the production of living materials that can reproduce, self-organize, and self-heal." In 2017 the ELM program contracted Ecovative Design to produce "a living hybrid composite building material... [to] genetically re-program that living material with responsive functionality [such as] wound repair... [and to] rapidly reuse and redeploy [the] material into new shapes, forms, and applications." In 2020 a research group at the University of Colorado, funded by an ELM grant, published a paper after successfully creating exponentially regenerating concrete.
Self-replicating concrete
Self-replicating concrete is produced using a mixture of sand and hydrogel, which are used as a growth medium for synechococcus bacteria to grow on.
Synthesis and fabrication
The sand-hydrogel mixture from which self-replicating concrete is made has a lower pH, lower ionic strength, and lower curing temperatures than a typical concrete mix, allowing it to serve as a growth medium for the bacteria. As the bacteria reproduce they spread through the medium, and biomineralize it with calcium carbonate, which is the main contributor to the overall strength and durability of the material. After mineralization the sand-hydrogel compound is strong enough to be used in construction, as concrete or mortar.
The bacteria in self-replicating concrete react to humidity changes: they are most active - and reproduce the fastest - in an environment with 100% humidity, though a drop to 50% does not have a large impact on the cellular activity. Lower humidity does result in a stronger material than high humidity.
As the bacteria reproduce, their biomineralization activity increases; this allows production capacity to scale exponentially.
Properties
The structural properties of this material are similar to those of Portland cement-based mortars: it has an elastic modulus of 293.9 MPa, and a tensile strength of 3.6 MPa (the minimum required value for Portland-cement based concrete is approximately 3.5 MPa); however it has a fracture energy of 170 N, which is much less than most standard concrete formulations, which can reach up to several kN.
Uses
Self-replicating concrete can be used in a variety of applications and environments, but the effect of humidity on the properties of the end material (see above) means that the application of the material must be tailored to its environment. In humid environments the material can be used as to fill cracks in roads, walls and sidewalks, sipping into cavities and growing into a solid mass as it sets; while in drier environments it can be used structurally, due to its increased strength in low-humidity environments.
Unlike traditional concrete, the production of which releases massive amounts of carbon dioxide to the atmosphere, the bacteria used in self-replicating concrete absorb carbon dioxide, resulting in a lower carbon footprint.
This self-replicating concrete is not meant to replace standard concrete, but to create a new class of materials, with a mixture of strength, ecological benefits, and biological functionality.
Calcium carbonate biocement
Biocement is a sand aggregate material produced through the process of microbiologically induced calcite precipitation (MICP). It is an environmentally friendly material which can be produced using a variety of stocks, from agricultural waste to mine tailings.
Synthesis and fabrication
Microscopic organisms are the key component in the formation of bioconcrete, as they provide the nucleation site for CaCO to precipitate on the surface. Microorganisms such as Sporosarcina pasteurii are useful in this process, as they create highly alkaline environments where dissolved inorganic carbon (DIC) is present at high amounts. These factors are essential for microbiologically induced calcite precipitation (MICP), which is the main mechanism in which bioconcrete is formed. Other organisms that can be used to induce this process include photosynthesizing microorganisms such as microalgae, cyanobacteria, and sulphate reducing bacteria (SRB) such as Desulfovibrio desulfuricans.
Calcium carbonate nucleation depends on four major factors:
Calcium concentration
DIC concentration
pH levels
Availability of nucleation sites
As long as calcium ion concentrations are high enough, microorganisms can create such an environment through processes such as ureolysis.
Advancements in optimizing methods to use microorganisms to facilitate carbonate precipitation are rapidly developing.
Properties
Biocement is able to "self-heal" due to bacteria, calcium lactate, nitrogen, and phosphorus components that are mixed into the material. These components have the ability to remain active in biocement for up to 200 years. Biocement like any other concrete can crack due to external forces and stresses. Unlike normal concrete however, the microorganisms in biocement can germinate when introduced to water. Rain can supply this water which is an environment that biocement would find itself in. Once introduced to water, the bacteria will activate and feed on the calcium lactate that was part of the mixture. This feeding process also consumes oxygen which converts the originally water-soluble calcium lactate into insoluble limestone. This limestone then solidifies on surface it is lying on, which in this case is the cracked area, thereby sealing the crack up.
Oxygen is one of the main elements that cause corrosion in materials such as metals. When biocement is used in steel reinforced concrete structures, the microorganisms consume the oxygen thereby increasing corrosion resistance. This property also allows for water resistance as it actually induces healing, and reducing overall corrosion. Water concrete aggregates are what are used to prevent corrosion and these also have the ability to be recycled. There are different methods to form these such as through crushing or grinding of the biocement.
The permeability of biocement is also higher compared to normal cement. This is due to the higher porosity of biocement. Higher porosity can lead to larger crack propagation when exposed to strong enough forces. Biocement is now roughly 20% composed of a self healing agent. This decreases its mechanical strength. The mechanical strength of bioconcrete is about 25% weaker than normal concrete, making its compressive strength lower. Organisms such as Pesudomonas aeruginosa are effective in creating biocement. These are unsafe to be near humans so these must be avoided.
Uses
Biocement is currently used in applications such as in sidewalks and pavements in buildings. There are ideas of biological building constructions as well. The uses of biocement are still not widespread because there is currently not a feasible method of mass-producing biocement to such a high extent. There is also much more definitive testing that needs to be done to confidently use biocement in such large scale applications where mechanical strength can not be compromised. The cost of biocement is also twice as much as normal concrete. Different uses in smaller applications however include spray bars, hoses, drop lines, and bee nesting. Biocement is still in its developmental stages however its potential proves promising for its future uses.
Mycelium composites
Mycelium composites are materials that are based on mycelium – the mass of branching, thread-like hyphae produced by fungi. There are several ways to synthesize and fabricate mycelium composites, lending to different properties and use cases of the finish product. Mycelium composites are economical and sustainable.
Synthesis and fabrication
Mycelium-based composites are usually synthesised by using different kinds of fungi, especially mushrooms. An individual microbe of fungi is introduced to different types of organic substances to form a composite. The selection of fungal species is important for creating a product with specific properties. Some of the fungal species that are used to make composites are G. lucidum, Ganoderma sp. P. ostretus, Pleurotus sp., T. versicolor, Trametes sp., etc. A dense network is formed when the mycelium of the microbe of fungi degrades and colonises the organic substance. Plant waste is a common organic substrate that is used in mycelium-based composites. Fungal mycelium is incubated with a plant waste product to produce sustainable alternatives mostly for petroleum-based materials. The mycelium and organic substrate need time to incubate properly and this time is crucial as it is the period that these particles interact together and bind to form a dense network and hence form a composite. During this incubation period, mycelium uses essential nutrients such as carbon, minerals, and water from the waste plant product. Some of the organic substrate components include cotton, wheat grains, rice husks, sorghum fibres, agricultural waste, sawdust, bread particles, banana peel, coffee residue, etc. The composites are synthesised and fabricated using different techniques such as adding carbohydrates, altering fermentation conditions, using different fabrication technology, altering post-processing stages, and modifying genetics or biochemicals to form products with certain properties. Fabrication of most of the mycelium composites are by using plastic molds, so the mycelium can be grown directly into the desired shape. Other fabrication methods include laminate skin mold, vacuum skin mold, glass mold, plywood mold, wooden mold, petri dish mold, tile mold, etc. During fabrication process, it is essential to have a sterilised environment, a controlled environment condition of light, temperature (25-35 °C) and humidity around 60-65% for the best results. One way to synthesise a mycelium based composite is by mixing different composition ratios of fibers, water and mycelium together and putting in a PVC molds in layers while compressing each layer and letting it incubate for couple of days. Mycelium based composites can be processed in foam, laminate and mycelium sheet by using processing techniques such as later cutting, cold and heat compression, etc. Mycelium composites tend to absorb water when they are newly fabricated, therefore this property can be changed by drying the product.
Properties
One of the advantages about using mycelium based composites is that properties can be altered depending on fabrication process and the use of different fungus. Properties depend on type of fungus used and where they are grown. Additionally, fungi has an ability to degrade the cellulose component of the plant to make composites in a preferable manner. Some important mechanical properties such as compressive strength, morphology, tensile strength, hydrophobicity, and flexural strength can be modified as well for different use of the composite. To increase the tensile strength, the composite can go through heat pressing. The properties of a mycelium composite are affected by its substrate; for example, a mycelium composite made out of 75 wt% rice hulls has a density of 193 kg/m3, while 75 wt% wheat grains has 359 kg/m3. Another method to increase the density of the composite would be by deleting a hydrophobin gene. These composites also have the ability of self-fusion which increases their strength. Mycelium based composites are usually compact, porous, lightweight and a good insulator. The main property of these composites is that they are entirely natural, therefore sustainable. Another advantage of mycelium based composites is that this substance acts as an insulator, is fireproof, nontoxic, water-resistant, rapidly growing, and able to bond with neighboring mycelium products. Mycelium-based foams (MBFs) and sandwich components are two common types of composite. MBFs are the most efficient type because of their low density property, high quality, and sustainability. The density of MBFs can be decreased by using substrates that are smaller than 2 mm in diameter. These composites have higher thermal conductivity as well.
Uses
One of the most common use of mycelium based composites is for the alternatives for petroleum and polystyrene based materials. These synthetic foams are usually used for sustainable design and architecture products. The use of mycelium based composites are based on their properties. There are several bio-sustainable companies
Further applications
Beyond the use of living building materials, the application of microbially induced calcium carbonate precipitation (MICP) has the possibility of helping remove pollutants from wastewater, soil, and the air. Currently, heavy metals and radionuclei provide a challenge to remove from water sources and soil. Radionuclei in ground water do not respond to traditional methods of pumping and treating the water, and for heavy metals contaminating soil, the methods of removal include phytoremediation and chemical leaching do work; however, these treatments are expensive, lack longevity in effectiveness, and can destroy the productivity of the soil for future uses. By using ureolytic bacteria that is capable of CaCO3 precipitation, the pollutants can move into the calc-be structure, thereby removing them from the soil or water. This works through substitution of calcium ions for pollutants that then form solid particles and can be removed. It's reported that 95% of these solid particles can be removed by using ureolytic bacteria. However, when calcium scaling in pipelines occurs, MICP cannot be used as it is calcium-based. Instead of calcium, it is possible to add a low concentration of urea to remove up to 90% of the calcium ions.
Another further application involves a self-constructed foundation that forms in response to pressure through the use of engineering bacteria. The engineered bacteria could be used to detect increased pressure in soil, and then cement the soil particles in place, effectively solidifying the soil. Within soil, pore pressure consists of two factors: the amount of applied stress, and how quickly water in the soil is able to drain. Through analyzing the biological behavior of the bacteria in response to a load and the mechanical behavior of the soil, a computational model can be created. With this model, certain genes within the bacteria can be identified and modified to respond a certain way to a certain pressure. However, the bacteria analyzed in this study was grown in a highly controlled lab, so real soil environments may not be as ideal. This is a limitation of the model and study it originated from, but it still remains a possible application of living building materials.
References
Construction
Building materials | Living building material | [
"Physics",
"Engineering"
] | 3,424 | [
"Building engineering",
"Construction",
"Materials",
"Building materials",
"Matter",
"Architecture"
] |
62,860,232 | https://en.wikipedia.org/wiki/Zoe%20Pikramenou | Zoe Pikramenou is Professor of Inorganic Chemistry and Photophysics at the University of Birmingham, where she is the first female professor in the chemistry department.
Education and career
Pikramenou graduated in 1987 with a B.Sc. in Chemistry from the University of Athens in Greece. She then moved to Michigan State University where she worked in the lab of Daniel G. Nocera, graduating with a Ph.D. in Chemistry in 1993. She then conducted post-doctoral studies at University of Strasbourg in France as a Marie Curie and Collège de France fellow working with Nobel prize-winner Jean-Marie Lehn. She became a lecturer at the University of Edinburgh in 1995, then was appointed to the University of Birmingham in 2000.
Research
Pikramenou is a inorganic chemist with experience in nanotechnology and photophysics, who has researched lanthanide luminescent complexes. Recent research has investigated how gold nanorods could be applied to treat cancerous cells in the body. This research is in partnership with the Canadian company Sona Nanotech Inc. Pikramenou has researched other applications of gold nanoparticles, including their use in tracking blood flow in capillary networks. She was part of a team that developed iridium-coated gold nanoparticles, significant because they have a longer lifetime of use. She has co-investigated platelet nodules, using microscopy.
Another medical application of Pikramenou's nanoparticle research includes the application of coated silica particles to treat sensitive teeth. As part of her doctoral research at Michigan State University, Pikramenou invented a nanoparticle bucket, which lights up when in contains a particular compound. This kind of microscopic bucket is described as a supramolecule.
Coated nanoparticles patent
In 2017, Pikramenou and her co-researcher Nicola J Rogers, were granted a patent to protect their invention of a new process of combining at least one metal complex and a surfactant.
Awards
2012 - Leverhulme Trust Research Fellowship
2007 - EPSRC Discipline Hopping Award with Chemical Engineering
2000 - The Aventis Scientia Europea Prize, Aventis Foundation and French Academy of Sciences for collaborative work with Physicist and Biologist
References
External links
The Zoe Pikramenou Photophysics Group
Professor Pikramenou's Inaugural Lecture
Michigan State University alumni
British nanotechnologists
Academics of the University of Birmingham
Year of birth missing (living people)
Living people
British women engineers
Women chemical engineers
21st-century women engineers
Women bioengineers
Place of birth missing (living people)
Nationality missing | Zoe Pikramenou | [
"Chemistry"
] | 527 | [
"Women chemical engineers",
"Chemical engineers"
] |
62,860,439 | https://en.wikipedia.org/wiki/Regular%20numerical%20predicate | In computer science and mathematics, more precisely in automata theory, model theory and formal language, a regular numerical predicate is a kind of relation over integers. Regular numerical predicates can also be considered as a subset of for some arity . One of the main interests of this class of predicates is that it can be defined in plenty of different ways, using different logical formalisms. Furthermore, most of the definitions use only basic notions, and thus allows to relate foundations of various fields of fundamental computer science such as automata theory, syntactic semigroup, model theory and semigroup theory.
The class of regular numerical predicate is denoted , and REG.
Definitions
The class of regular numerical predicate admits a lot of equivalent definitions. They are now given. In all of those definitions, we fix and a (numerical) predicate of arity .
Automata with variables
The first definition encodes predicate as a formal language. A predicate is said to be regular if the formal language is regular.
Let the alphabet be the set of subset of . Given a vector of integers , it is represented by the word of length whose -th letter is . For example, the vector is represented by the word .
We then define as .
The numerical predicate is said to be regular if is a regular language over the alphabet . This is the reason for the use of the word "regular" to describe this kind of numerical predicate.
Automata reading unary numbers
This second definition is similar to the previous one. Predicates are encoded into languages in a different way, and the predicate is said to be regular if and only if the language is regular.
Our alphabet is the set of vectors of binary digits. That is: . Before explaining how to encode a vector of numbers, we explain how to encode a single number.
Given a length and a number , the unary representation of of length is the word over the binary alphabet , beginning by a sequence of "1"'s, followed by "0"'s. For example, the unary representation of 1 of length 4 is .
Given a vector of integers , let . The vector is represented by the word such that, the projection of over its -th component is . For example, the representation of is . This is a word whose letters are the vectors , and and whose projection over each components are , and .
As in the previous definition, the numerical predicate is said to be regular if is a regular language over the alphabet .
A predicate is regular if and only if it can be defined by a monadic second order formula , or equivalently by an existential monadic second order formula, where the only atomic predicate is the successor function .
A predicate is regular if and only if it can be defined by a first order logic formula , where the atomic predicates are:
the order relation ,
the predicate stating that a number is a multiple of a constant , that is .
Congruence arithmetic
The language of congruence arithmetic is defined as the est of Boolean combinations, where the atomic predicates are:
the addition of a constant , with an integral constant,
the order relation ,
the modular relations, with a fixed modular value. That is, predicates of the form where and are fixed constants and is a variable.
A predicate is regular if and only if it can be defined in the language of congruence arithmetic. The equivalence with previous definition is due to quantifier elimination.
Using recursion and patterns
This definition requires a fixed parameter . A set is said to be regular if it is -regular for some .
In order to introduce the definition of -regular, the trivial case where should be considered separately. When , then the predicate is either the constant true or the constant false. Those two predicates are said to be -regular (for every ). Let us now assume that . In order to introduce the definition of regular predicate in this case, we need to introduce the notion of section of a predicate.
The section of is the predicate of arity where the -th component is fixed to . Formally, it is defined as . For example, let us consider the sum predicate . Then is the predicate which adds the constant , and is the predicate which states that the sum of its two elements is .
The last equivalent definition of regular predicate can now be given. A predicate of arity is -regular if it satisfies the two following conditions:
all of its sections are -regular,
there exists a threshold such that, for each vectors with each , .
The second property intuitively means that, when number are big enough, then their exact value does not matter. The properties which matters are the order relation between the numbers and their value modulo the period .
Using recognizable semigroups
Given a subset , let be the characteristic vector of . That is, the vector in whose -th component is 1 if , and 0 otherwise. Given a sequence of sets, let .
The predicate is regular if and only if for each increasing sequence of set , is a recognizable submonoid of .
Definition of non regular language
The predicate is regular if and only if all languages which can be defined in first order logic with atomic predicates for letters and the atomic predicate are regular. The same property would hold for the monadic second order logic, and with modular quantifiers.
Reducing arity
The following property allows to reduce an arbitrarily complex non-regular predicate to a simpler binary predicate which is also non-regular.
Let us assume that is definable in Presburger Arithmetic. The predicate is non regular if and only if there exists a formula in which defines the multiplication by a rational . More precisely, it allows to define the non-regular predicate for some .
Properties
The class of regular numerical predicate satisfies many properties.
Satisfiability
As in previous case, let us assume that is definable in Presburger Arithmetic. The satisfiability of is decidable if and only if is regular.
This theorem is due to the previous property and the fact that the satisfiability of is undecidable when and .
Closure property
The class of regular predicates is closed under union, intersection, complement, taking a section, projection and Cartesian product. All of those properties follows directly from the definition of this class as the class of predicates definable in .
Decidability
It is decidable whether a predicate defined in Presburger arithmetic is regular.
Elimination of quantifier
The logic considered above admit the elimination of quantifier. More precisely, the algorithm for elimination of quantifier by Cooper does not introduce multiplication by constants nor sums of variable. Therefore, when applied to a it returns a quantifier-free formula in.
References
Automata (computation)
Theoretical computer science | Regular numerical predicate | [
"Mathematics"
] | 1,423 | [
"Theoretical computer science",
"Formal languages",
"Mathematical logic",
"Applied mathematics"
] |
62,861,062 | https://en.wikipedia.org/wiki/National%20Sewerage%20Program | The National Sewerage Program was an Australian federal program under the Whitlam and Fraser governments established to provide funding for the expansion of municipal sewerage systems. At the time Australia was lagging behind other developed nations and, as of the commencement of the program in 1972, 17.2% of the Australian population were not connected to sewerage. Even in major population centers like Sydney and Melbourne, there was a backlog of over 318,000 homes waiting to be connected to municipal sewerage systems. The program was administered by the newly formed Department of Urban and Regional Development, and over AUD$330 million of funding was allocated to be distributed to individual states and territories over ten years. Over the life of the program the sewerage connection backlog was reduced by 30% to 40%. The program was abolished in 1977 by the incumbent Fraser government. Consequently, many communities struggled to connect to sewerage for decades afterwards.
References
Engineering projects
Public policy in Australia
1972 establishments in Australia
1977 disestablishments in Australia
Sewerage infrastructure in Australia | National Sewerage Program | [
"Engineering"
] | 212 | [
"nan"
] |
62,861,843 | https://en.wikipedia.org/wiki/NGC%20560 | NGC 560 is a lenticular galaxy in the constellation Cetus. It is estimated to be about 250 million light-years from the Milky Way and has a diameter of approximately 150,000 light years. It is part of the Abell 194 galaxy cluster. NGC 560 was discovered on October 1, 1785 by the German-British astronomer William Herschel.
One supernova has been observed in NGC 560: SN 2024pnw (type Ia, mag. 18.3).
See also
List of NGC objects (1–1000)
References
External links
560
Lenticular galaxies
Cetus
Discoveries by William Herschel
005430 | NGC 560 | [
"Astronomy"
] | 128 | [
"Cetus",
"Constellations"
] |
62,861,893 | https://en.wikipedia.org/wiki/NGC%20570 | NGC 570 is a barred spiral galaxy. It is located in the Cetus constellation about 250 million light-years from the Milky Way. It was discovered by the American astronomer George Mary Searle in 1867.
One supernova has been observed in NGC 570: SN2021qwh (typeIa, mag. 18.45).
See also
List of NGC objects (1–1000)
References
External links
570
Barred spiral galaxies
Cetus
Discoveries by George Searle
005539
+00-04-162
01061 | NGC 570 | [
"Astronomy"
] | 109 | [
"Cetus",
"Constellations"
] |
62,862,012 | https://en.wikipedia.org/wiki/Institute%20of%20Physics%20Awards | The Institute of Physics awards numerous prizes to acknowledge contributions to physics research, education and applications. It also offers smaller specific subject-group prizes, such as for PhD thesis submissions.
Bilateral awards
The Max Born Medal and Prize is awarded yearly by the German Physical Society and the Institute of Physics in memory of the German physicist Max Born. The prize recognizes "outstanding contributions to physics" and is awarded to physicists based in Germany and in the UK or Ireland in alternate years.
The Fernand Holweck Medal and Prize is awarded jointly by the French and British Physical Societies for distinguished work in any aspect of physics that is ongoing or has been carried out within the 10 years preceding the award.
The Harrie Massey Medal and Prize is awarded biennially jointly by the Institute of Physics and by The Australian Institute of Physics.
The Giuseppe Occhialini Medal and Prize is awarded to physicists in alternating years who work in Italy (even dated years) or the UK or Ireland (odd dated years).
Business awards
The Katharine Burr Blodgett Medal and Prize is a gold medal awarded annually for outstanding contributions to the organisation or applications of physics to a physicist in an industrial or commercial context in any sector.
The Dennis Gabor Medal and Prize is a prize awarded for distinguished contributions to the application of physics in an industrial, commercial or business context.
The Clifford Paterson Medal and Prize is awarded for exceptional early career contributions to the application of physics.
The Lee Lucas Award
The Business Innovation Award
The Business Start-Up Award
The Apprentice Award
The Apprenticeship Employer Award
Education awards
The Lawrence Bragg Medal and Prize
First awarded in 1967, is a gold medal for outstanding and sustained contributions to physics education. Previous winners are:
1967 Donald McGill (posthumously)
1969 John Logan Lewis
1971 George Robert Noakes
1973 Jon Michael Ogborn and Paul Joseph Black
1975 William Albert Coates
1977 Edward John Wenham
1979 Margaret Maureen Hurst
1981 Geoffrey Edward Foxcroft
1983 Charles Alfred Taylor
1985 Eric Malcolm Rogers
1986 Wilfred Llowarch
1987 James Turnbull Jardine
1988 Anthony P French
1989 J Goronwy Jones
1990 John Marden Osborne
1991 Kevin William Keohane
1992 J Colin Siddons
1993 Christopher Anthony Butlin
1994 Cyril Isenberg
1995 Bryan Reginald Chapman
1996 Brenda Margaret Jennison
1997 Timothy David Robert Hickson
1998 Maurice George Ebison
1999 Averil Mary Macdonald
2000 Frank Russell Stannard
2001 George Marx
2002 Robert Lambourne and Michael Harry Tinker
2003 Ian Lawrence
2004 Elizabeth Swinbank
2005 Ken Dobson
2006 Derek Raine
2007 Philip Britton
2008 Robin Millar
2009 Becky Parker
2010 Peter Campbell
2011 Philip Harland Scott
2012 Katherine Blundell
2013 Bob Kibble
2014 Peter Vukusic
2015 Paula Chadwick
2016 Stuart Farmer
2017 Mary Whitehouse
2018 Bobby Acharya
2019 Mark Warner and Lisa Jardine-Wright
2020 Nicholas St John Braithwaite
2022 Eilish McLoughlin
2024 Stephen Blundell
The Marie Curie-Sklodowska Medal and Prize
Established in 2016, is awarded for "distinguished contributions to physics education and to widening participation within it."
The Daphne Jackson Medal and Prize
Established in 2016, is awarded "for exceptional early career contributions to physics education and to widening participation within it."
The Teacher of Physics Award
Since 1986, celebrates the success of secondary school physics teachers who have raised the profile of physics and science in schools.
The Technician Award
To recognise the experience of technicians and their contribution to physics
The Goronwy Jones prize
Awarded to the top-scoring A-level candidate in Physics in Wales.
Outreach awards
The Kelvin Medal and Prize is a gold medal instigated in October 1994 in recognition of the importance of promoting public awareness of the place of physics in the world, of its contributions to the quality of life and its advancement of an understanding of the physical world and the place of humanity within it.
The Lise Meitner Medal and Prize, established in 2016, is awarded for "distinguished contributions to public engagement within physics."
The Mary Somerville Medal and Prize
Research awards
The Isaac Newton Medal and Prize is a gold medal awarded annually to any physicist, regardless of subject area, background or nationality, for outstanding contributions to physics. It is accompanied by a prize of £1000, and the recipient is invited to give the Newton lecture.
The Paul Dirac Medal and Prize is a gold medal awarded for outstanding and sustained contributions to theoretical physics.
The Michael Faraday Medal and Prize is a gold medal awarded annually for outstanding contributions to experimental physics to a physicist of international reputation in any sector.
The Richard Glazebrook Medal and Prize, established in 1965, is a gold medal awarded for "outstanding and sustained contributions to leadership in a physics context."
The John William Strutt, Lord Rayleigh Medal and Prize, established in 2008, is awarded biennially in odd-numbered years, for distinguished research in theoretical, mathematical or computational physics.
The Sam Edwards Medal and Prize is awarded for distinguished contributions in soft matter physics
The Rosalind Franklin Medal and Prize is awarded for distinguished contributions to physics applied to the life sciences
The Nevill Mott Medal and Prize is awarded for distinguished contributions to condensed matter physics
The David Tabor Medal and Prize is awarded for distinguished contributions to surface or nanoscale physics.
The Cecilia Payne-Gaposchkin Medal and Prize is awarded for plasma or space physics
The Edward Appleton Medal and Prize is awarded for distinguished research in environmental, earth or atmospheric physics. Originally named after Charles Chree, it was established in 1941 and is currently awarded in even-dated years.
The Thomas Young Medal and Prize is awarded biennially in odd-numbered years, for distinguished research in the field of optics, including physics outside the visible region.
The Joseph Thomson Medal and Prize, established in 2008, is awarded biennially, in even-numbered years, for distinguished research in atomic physics (including quantum optics) or molecular physics.
The Ernest Rutherford Medal and Prize, awarded biennially in even-numbered years, was instituted in 1966, replacing the Rutherford Memorial Lecture. The award recognises distinguished research in nuclear physics or nuclear technology and is named in honour of Lord Rutherford of Nelson.
The James Chadwick Medal and Prize is awarded "for distinguished contributions to particle physics."
The Fred Hoyle Medal and Prize is awarded for distinguished contributions to astrophysics or cosmology
The Peter Mansfield Medal and Prize is awarded for medical physics
The James Joule Medal and Prize is awarded for applied physics
The James Clerk Maxwell Medal and Prize is awarded annually (previously between 1962 and 1970, every two years) to recognize outstanding early-career contributions to theoretical physics.
The Henry Moseley Medal and Prize is awarded for exceptional early career contributions to experimental physics
The Jocelyn Bell Burnell Medal and Prize was originally known as the 'Very Early Career Female Physicist Award'
The Simon Memorial Prize
Service to the IOP awards
The President's Medal can be given to both physicists and non-physicists who have provided meritorious services in various fields of endeavour which were of benefit to physics in general and the Institute in particular.
The Phillips Award is awarded for distinguished service to the Institute of Physics.
See also
Institute of Physics
List of physics awards
References
External links
Science and technology in the United Kingdom
Institute of Physics
Physics awards
Awards of the Institute of Physics
Lists of science and technology awards
Lists of awards by awarding entity | Institute of Physics Awards | [
"Technology"
] | 1,458 | [
"Science and technology awards",
"Lists of science and technology awards",
"Physics awards"
] |
62,862,874 | https://en.wikipedia.org/wiki/Dirac%20Medal%20%28ICTP%29 | The Dirac Medal of the ICTP is given each year by the International Centre for Theoretical Physics (ICTP) in honour of physicist Paul Dirac. The award, announced each year on 8 August (Dirac's birthday), was first awarded in 1985.
An international committee of distinguished scientists selects the winners from a list of nominated candidates. The Committee invites nominations from scientists working in the fields of theoretical physics or mathematics.
The Dirac Medal of the ICTP is not awarded to Nobel Laureates, Fields Medalists, or Wolf Prize winners.
However, several Dirac Medallists have subsequently won one of these awards.
The medallists receive a prize of US$5,000.
Recipients
See also
List of physics awards
List of awards named after people
References
Physics awards
Awards established in 1985 | Dirac Medal (ICTP) | [
"Technology"
] | 161 | [
"Science and technology awards",
"Physics awards"
] |
62,863,498 | https://en.wikipedia.org/wiki/Elena%20Besley | Elena Besley (née Bichoutskaia) is a British scientist who is Professor of Theoretical and Computational Chemistry at the University of Nottingham. She holds a Royal Society Wolfson Fellowship and is Associate Editor of Nano Letters.
Early life and education
Besley studied physics at Saint Petersburg State University and graduated with a Master of Science (MSci) degree in physics in 1993. In 2000, she completed a joint honours PhD in physics and mathematics at Saint Petersburg State University under the supervision of Alexander Devdariani and joined Queen's University Belfast on a NATO–Royal Society fellowship.
Research and career
Between 2000 and 2007, Besley had postdoctoral research appointments at the University of Nottingham, the University of Sussex, and the University of Cambridge. In 2007 Besley was awarded a Royal Society Relocation Fellowship at the University of Nottingham and a Visiting Academic Research Fellowship at the Australian National University, Canberra.
At the University of Nottingham, Besley was appointed to Lecturer in Theoretical and Computational Chemistry in 2011, followed by promotion to Associate Professor in 2014, and to Professor of Theoretical and Computational Chemistry in 2015. Besley is featured in an expert database for Outstanding Female Scientists and Scholars “AcademiaNet: Profiles of Leading Women Scientists”.
Her research includes the development of theoretical and computational methods for the prediction of materials properties; computational modelling of the behaviour, properties and manipulation of nanomaterials; investigations into the electrostatic interactions and self-assembly of materials; gas storage and interactions in porous solids. She has investigated how the electron beams of transmission electron microscopes interact with materials.
Awards and honours
1996 UNESCO Anniversary Award “for distinguished success in study and scientific activities”
2000 Royal Society NATO Postdoctoral Fellowship
2007 Royal Society UK Relocation Fellowship
2008 EPSRC Career Acceleration Fellowship
2012 New Directions for EPSRC Research Leaders Award
2013 ERC Consolidator Grant
2017 Fellow of the Royal Society of Chemistry
2021 Royal Society Leverhulme Trust Senior Research Fellowship
Select publications
Her publications include:
References
Living people
Year of birth missing (living people)
Academics of the University of Nottingham
Saint Petersburg State University alumni
Fellows of the Royal Society of Chemistry
Academics of Queen's University Belfast
Academics of the University of Sussex
Women materials scientists and engineers
British materials scientists
Computational chemists | Elena Besley | [
"Chemistry",
"Materials_science",
"Technology"
] | 443 | [
"Computational chemists",
"Computational chemistry",
"Theoretical chemists",
"Materials scientists and engineers",
"Women materials scientists and engineers",
"Women in science and technology"
] |
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