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54,729,289 | https://en.wikipedia.org/wiki/Maryanthe%20Malliaris | Maryanthe Elizabeth Malliaris is a professor of mathematics at the University of Chicago, a specialist in model theory.
Early life and education
Malliaris is the daughter of Anastasios G. (Tassos) Malliaris, an economist at Loyola University Chicago, and Mary E. Malliaris, Professor of Information Systems at Loyola.
As an undergraduate at Harvard College, Malliaris wrote for the Harvard Crimson, contributed a biography of Polish sociologist Zygmunt Bauman to the Encyclopedia of Postmodernism, and worked for a startup called Zaps.
She graduated from Harvard in 2001 with a concentration in mathematics, and earned her PhD in 2009 from the University of California, Berkeley under the supervision of Thomas Scanlon. Her dissertation was Persistence and Regularity in Unstable Model Theory.
Research
In her dissertation and postdoctoral research, Malliaris studied unstable model theory and its connection, via characteristic sequences, to graph theoretic concepts such as the Szemerédi regularity lemma.
She is also known for two joint papers with Saharon Shelah connecting topology, set theory, and model theory.
In this work, Malliaris and Shelah used Keisler's order, a construction from model theory,
to prove the equality between two cardinal characteristics of the continuum, 𝖕 and 𝖙, which are greater than the smallest infinite cardinal and less than or equal to the cardinality of the continuum.
This resolved a problem in set theory that had been open for fifty years.
Their work also solved another problem that had been open almost as long, by characterizing the maximal theories in Keisler's order.
Awards and honors
Malliaris won a Kurt Gödel Research Prize in 2010 for her work in unstable model theory.
In 2017, she and Saharon Shelah shared the Hausdorff Medal of the European Set Theory Society for their joint papers.
She was an invited speaker at the 2018 International Congress of Mathematicians.
Selected publications
References
External links
Home page
Year of birth missing (living people)
Living people
21st-century American mathematicians
Model theorists
University of California, Berkeley alumni
University of Chicago faculty
The Harvard Crimson people
21st-century American women mathematicians
Hausdorff Medal winners | Maryanthe Malliaris | [
"Mathematics"
] | 444 | [
"Model theorists",
"Model theory"
] |
54,729,451 | https://en.wikipedia.org/wiki/NGC%203941 | NGC 3941 is a barred lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 40 million light years from Earth, which, given its apparent dimensions, means that NGC 3941 is about 40,000 light years across. It was discovered by William Herschel in 1787.
Characteristics
The galaxy has a counterrotating extended gas disk, which was possibly formed by a galaxy merger of accretion of gas with oppositely directed angular momentum. The disk has low velocity dispersion throughout, which suggests it has settled into equilibrium. The gas is found primarily in two rings. The inner appears almost circular in HI imaging, which may mean it is inclined ~20° or more with respect to the stellar disk, whereas the outer ring has approximately the same ellipticity with the stellar disk. The stellar disk is symmetric and there are evidence of weak spiral arms outside the primary bar. In the infrared Ks-band, the bar has ansae-type morphology and in the inner elliptical there is an inner disc showing two-armed spirals. Based on the fact that the spiral arms and the gas are rotating in different directions it has been suggested that the inner ionised gas and the outer HI gas are inclined, almost perpendicular to the stellar disk. The galaxy features also a secondary bar.
NGC 3941 is type 2 Seyfert galaxy. In the centre of the galaxy lies a supermassive black hole whose mass is estimated to be, based on velocity dispersion, 141 million (108.14) .
Supernova
One supernova has been observed in NGC 3941: SN 2018pv (Type Ia, mag 15.1) was discovered by Masaki Tsuboi on 3 February 2018. It reached magnitude 12.7, making it tied with SN 2018aoz for the brightest supernova of 2018.
Nearby galaxies
NGC 3941 forms a small galaxy group with NGC 3930 and UGC 6955, which is part of the Ursa Major Cluster.
References
External links
Barred lenticular galaxies
Ursa Major
3941
06857
37235 | NGC 3941 | [
"Astronomy"
] | 426 | [
"Ursa Major",
"Constellations"
] |
54,729,559 | https://en.wikipedia.org/wiki/RIK-210 | RIK-210 is a star located north of Scorpius. It is known for its mysterious dimming events. The dips are observed with stable period of 5.667 days, but their triangular shape is inconsistent with the planetary eclipses. Instead, the diffuse cloud on synchronous orbit may be responsible.
References
M-type stars
Scorpius
J16232454-1717270
Pre-main-sequence stars | RIK-210 | [
"Astronomy"
] | 93 | [
"Scorpius",
"Constellations"
] |
54,729,846 | https://en.wikipedia.org/wiki/Kentrophoros | Kentrophoros is a genus of ciliates in the class Karyorelictea. Ciliates in this genus lack a distinct oral apparatus and depend primarily on symbiotic bacteria for their nutrition.
Systematics
Kentrophoros is the sole genus in the family Kentrophoridae Jankowski 1980. The type species of the genus is K. fasciolatus Sauerbrey 1928, first described from the Bay of Kiel. Synonyms are Centrophorus Kahl 1931 (an illegitimate synonym because the name was already used for a genus of sharks) and Centrophorella Kahl 1935. Fifteen species of Kentrophoros have been formally described, although several of these names may be synonyms for the same species.
Description
The ciliates are long and ribbon-shaped, like other karyorelictean ciliates that live in the marine interstitial habitat. In some species, the cell body is folded or involuted into a tube or more elaborate shapes. The ventral side is ciliated, while the dorsal side is mostly unciliated except for a single "circle kinety" at the margin. The dorsal side is covered with a single layer of symbiotic bacteria. Kentrophoros lacks a distinct oral apparatus, although densely-spaced kinetids associated with fibers (nematodesmata) at the anterior part of the cell may be vestiges of the oral apparatus. The number and arrangement of nuclei within the cell are also variable between species. Some species have only one micronucleus and two macronuclei, but others can have multiple clusters of macro- and micronuclei, or so-called "composite nuclei" where each cluster of macro- and micronuclei is enclosed in another membrane.
Kentrophoros live in coastal marine sediments, where they prefer the interface between oxic and anoxic layers.
Symbiotic bacteria
The dorsal side of Kentrophoros is covered in a single layer of rod-shaped bacterial symbionts. These bacteria gain their energy from oxidizing sulfide, and unlike other sulfur-oxidizing symbionts, lack the genetic capacity to fix CO2 autotrophically into biomass; instead they appear to be entirely heterotrophic. The ciliates ingest the bacteria as their primary food source. This symbiosis has therefore been called a "kitchen garden" carried by the ciliates to feed themselves. The symbionts occupy about 50% of the total volume. They belong to a group in the Gammaproteobacteria for which the provisional name "Candidatus Kentron" has been proposed. Similar symbioses between eukaryotic hosts and sulfur-oxidizing bacteria include the ciliate Zoothamnium niveum, oligochaete worm Olavius algarvensis, and flatworm Paracatenula.
References
Karyorelictea
Chemosynthetic symbiosis
Ciliate genera | Kentrophoros | [
"Biology"
] | 625 | [
"Biological interactions",
"Chemosynthetic symbiosis",
"Behavior",
"Symbiosis"
] |
54,730,939 | https://en.wikipedia.org/wiki/Notch%20%28engineering%29 | In mechanical engineering and materials science, a notch refers to a V-shaped, U-shaped, or semi-circular defect deliberately introduced into a planar material. In structural components, a notch causes a stress concentration which can result in the initiation and growth of fatigue cracks. Notches are used in materials characterization to determine fracture mechanics related properties such as fracture toughness and rates of fatigue crack growth.
Notches are commonly used in material impact tests where a morphological crack of a controlled origin is necessary to achieve standardized characterization of fracture resistance of the material. The most common is the Charpy impact test, which uses a pendulum hammer (striker) to strike a horizontal notched specimen. The height of its subsequent swing-through is used to determine the energy absorbed during fracture. The Izod impact strength test uses a circular notched vertical specimen in a cantilever configuration. Charpy testing is conducting with U- or V-notches whereby the striker contacts the specimen directly behind the notch, whereas the now largely obsolete Izod method involves a semi-circular notch facing the striker. Notched specimens are used in other characterization protocols, such as tensile and fatigue tests.
Types of notches
The type of notch introduced to a specimen depends on the material and characterization employed. For standardized testing of fracture toughness by the Charpy impact method, specimen and notch dimensions are most often taken from American standard ASTM E23, or British standard BS EN ISO 148-1:2009. For all notch types, a key parameter in governing stress concentration and failure in notched materials is the notch tip curvature or radius.
Sharp tipped V-shaped notches are often used in standard fracture toughness testing for ductile materials, polymers and for the characterization of weld strength. The application of such notches for hard-steels is problematic due to sensitivity to grain alignment, which is why torsional testing may be applied for such materials instead.
A U notch is an elongated notch having a round notch-tip, being deeper than it is wide. This notch is also often referred to as C-notch, and is the most widely form of introduced notch, due to the repeatability of results obtained from notch specimens. Correlating U-Notch performance to V-Notch equivalent is challenging and is carried out on a case by case basis, there is no standardized correlation between performance values obtained with the two notch types.
A keyhole notch is typically considered as a slit ending in a hole of a given radius. This type of notch is most often considered in numerical models. Fracture toughness results obtained from keyhole notch testing are often higher than those obtained from V-notched or pre-cracked specimens.
See also
Charpy impact test
References
Fracture mechanics | Notch (engineering) | [
"Materials_science",
"Engineering"
] | 554 | [
"Structural engineering",
"Materials degradation",
"Materials science",
"Fracture mechanics"
] |
54,731,593 | https://en.wikipedia.org/wiki/NGC%204026 | NGC 4026 is an edge-on lenticular galaxy in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 4026 is about 80,000 light years across. It was discovered by William Herschel on April 12, 1789.
The galaxy hosts a supermassive black hole with estimated mass 108.33±0.109 (166-275 million) .
Nearby galaxies
NGC 4026 belongs to M109 Group, the largest subgroup of galaxies with the Ursa Major Cluster. In the vicinity of NGC 4026 lie some low surface brightness spiral galaxies, UGC 6917 (42 arcminutes from NGC 4026), UGC 6922 (26 arcminutes from NGC 4026) and UGC 6956 (10 arcminutes from NGC 4026).
NGC 4026 appears disturbed in HI imaging, with a filament extending southward. The mass of HI in NGC 4026 is below 0.71 × 108 M⊙. The total HI mass in NGC 4026, UGC 6956 and the HI filament is estimated to be 7.94 × 108 M⊙. This phenomenon has been studied and evidence implies the presence of tidal forces and tidal interactions between the galaxies.
References
External links
Lenticular galaxies
Ursa Major
4026
06985
37760
M109 Group | NGC 4026 | [
"Astronomy"
] | 287 | [
"Ursa Major",
"Constellations"
] |
54,731,628 | https://en.wikipedia.org/wiki/Arsonium | The arsonium cation is a positively charged polyatomic ion with the chemical formula . An arsonium salt is a salt containing either the arsonium () cation, such as arsonium bromide () and arsonium iodide (), which can be synthesized by reacting arsine with hydrogen bromide or hydrogen iodide. Or more commonly, as organic derivative such as the quaternary arsonium salts (CAS: , hydrate form) and the zwitterionic compound arsenobetaine.
References
Arsenic(−III) compounds
Cations | Arsonium | [
"Physics",
"Chemistry"
] | 118 | [
"Cations",
"Ions",
"Matter"
] |
54,732,770 | https://en.wikipedia.org/wiki/Genealogy%20of%20Ankhefensekhmet | The Genealogy of Ankhefensekhmet or Genealogy of the Memphite priestly elite (Berlin 23673) is an ancient Egyptian relief – sometimes referred to as a stela – normally identified as having been made during the 8th century BCE, under the reign of pharaoh Shoshenq V of the late 22nd Dynasty. A surviving block is kept at the Egyptian Museum of Berlin. The relief was issued by a priest called Ankhefensekhmet with the purpose of illustrating his own genealogy. The relief traces back Ankhefensekhmet's sequence of ancestors up to 64 generations before, with the earliest individual, Ptahemheb, identified by Ritner as being from the time of Nebhepetre (Mentuhotep II) of the 11th Dynasty and alternatively identified by Borchart as being from the time of Nebkaure Khety of the 10th Dynasty. On 25 occasions the genealogy also names the pharaoh or king who was ruling at the time.
Many of Ankhefensekhmet's ancestors bore the title of "Chief of master-craftsmen", more commonly referred as "High Priest of Ptah". Robert K. Ritner suggested that the mention of pharaohs of the Hyksos period (Apepi (3/5), the otherwise unknown Sharek (3/6) and Aaqen (3/12)) should reflect the continuity of the sequence of ancestors, rather than an acceptance of the Hyksos rule by the indigenous people of Egypt; in fact, the name Aaqen, which means "Valiant ass", looks like an intentional misspelling of "Strong of valour". Still earlier, Alan Gardiner also suggested that Aaqen may be a mocking name for Aaqenenre ("Great and strong is Ra"), which is one of Apepi's throne names.
Text
(1/1) The god's father of Ptah and prophet of Sekhmet, Ankhefensekhmet, son of
(1/2) the prophet of Sekhmet, Pahemnetjer, son of
(1/3) the prophet of Sekhmet, Pasherensekhmet, son of
(1/4) the prophet and chief of secrets of the sanctuary, Pahemnetjer, son of
(1/5) the prophet [...] in Letopolis, Sisekhmet, son of
(1/6) the prophet of Sekhmet, Pahemnetjer, son of
(1/7) the prophet and chief of secrets of the sanctuary, Iweefaenphtah, son of
(1/8) the prophet and chief of secrets of the sanctuary, Pahemnetjer, son of
(1/9) the prophet and chief of secrets of the sanctuary, Shedsunefertum, son of
(1/10) the prophet, Ankhefensekhmet, son of
(1/11) the chief of secrets of the sanctuary and prophet [...], Ashakhet II, son of
(1/12) the prophet, Pipi B, in the reign of king Psusennes I, son of
(1/13) the high priest of Ptah, Horsiese, in the reign of king Psusennes I, son of
(1/14) the high priest of Ptah, Pipi A, in the reign of king Psusennes I, son of
(1/15) the high priest of Ptah, Ashakhet I, in the reign of king Amenemnisu, son of [missing block(?)]
(2/1) the high priest of Ptah, Ptahemakhet, [...]
(2/2) the high priest of Ptah, Neferronpet, in the reign of king Ramesses II, son of
(2/3) the high priest of Ptah, Ptahemakhet, in the reign of king Ramesses II, son of
(2/4) the high priest of Ptah, [...]neshnet, in the reign of king Ramesses II, son of
(2/5) the god's father of Amun in Karnak, overseer of the works of Ramesses II, Ptahhotep, son of
(2/6) the high priest of Ptah, Netjerwyhotep, in the reign of king Seti I, son of
(2/7) the high priest of Ptah, Sokaremsaf, in the reign of king Seti I, son of
(2/8) the high priest of Ptah, Tiye, in the reign of king Horemheb, son of
(2/9) the god's father of Amun [in Kar]nak, Sokaremsaf, son of
(2/10) the god's father of Sekhmet, wab-priest of the king and god's father Ay, Ipu, son of
(2/11) the high priest of Ptah, Wermer, in the reign of king Amenhotep III, son of
(2/12) the high priest of Ptah, Pempanebes, in the reign of king Amenhotep III, son of
(2/13) the god's father and chief of secrets of Ptah, Nehememptah, son of
(2/14) the setem-priest of Ptah, the chief of seers, in the reign of king Thutmose III, son [missing block(?)]
(3/1) the god's father, Tiye, son of
(3/2) the high priest of Ptah, Paimired, in the reign of king Amenhotep I, son of
(3/3) the god's father and chief of secrets of Ptah, Tiye, son of
(3/4) the high priest of Ptah, Montu, in the reign of king Ahmose I, son of
(3/5) the god's father and chief of seers of Heliopolis, Hormaakheru, in the reign of king Apepi, son of
(3/6) the setem-priest of Ptah, Werhotep, in the reign of king Sharek, son of
(3/7) the god's father, Horsiese, son of
(3/8) the god's father, Irmer, son of
(3/9) the god's father, Kahap, son of
(3/10) the wab-priest and lector priest, Horemhotep, son of
(3/11) the god's father and chief of secrets of Ptah, Ptahemhat, son of
(3/12) the setem-priest of Ptah, Paser, in the reign of king Aaqen, son of
(3/13) the high priest of Ptah, Sermut(?), in the reign of king Ibi, son [of]
(3/14) [... son of]
(3/15) [... son of] [missing block(?)]
(4/1) the high priest of Ptah, Wehket, in the reign of king Senusret III, son of
(4/2) the god's father and prophet of Sobek, Sehetepibseneb, son of
(4/3) the high priest of Ptah, Nubkaure–ankh, in the reign of king Senusret III, son of
(4/4) the high priest of Ptah, Khakare–ankh, in the reign of king Amenemhat II, son of
(4/5) the high priest of Ptah, Sehetepibre–ankh, in the reign of king Senusret I, son of
(4/6) the god's father, overseer of the city and vizier, Netjerwyhotep, in the reign of king Amenemhat I, son of
(4/7) the god's father, overseer of craftsmen, and controller of every office of the king, Sokaremheb, son of
(4/8) [the...and] prophet of Satis lady of Ankhtawy, Nebneferu, son of
(4/9) the wab-priest and lector priest, Minemheb, son of
(4/10) the god's father, Ptahhotep, son of
(4/11) the god's father and chief of secrets of Ptah, Nehemen, son of
(4/12) the god's father and chief of secrets of Ptah, Minemhat, son of
(4/13) the high priest of Ptah, Ptahemheb, in the reign of king Mentuhotep II, son [of]
(4/14) [...son of] [missing block(?)]
See also
Stela of Pasenhor
References
Citations
Bibliography
External links
Ankhefensekhmet
Ankhefensekhmet
Ankhefensekhmet
Ankhefensekhmet
Ankhefensekhmet
Ancient Egyptian King lists
Egyptian inscriptions
Genealogy
Ptah | Genealogy of Ankhefensekhmet | [
"Biology"
] | 1,967 | [
"Phylogenetics",
"Genealogy"
] |
54,734,615 | https://en.wikipedia.org/wiki/Nephromyces | Nephromyces is a genus of apicomplexans that are symbionts of the ascidian genus Molgula (sea grapes).
Systematics
Nephromyces was first described in 1888 by Alfred Mathieu Giard as a chytrid fungus, because of its filamentous cells. He formally named three species, each corresponding to a different species of the host animal. Molecular phylogenetics later showed that Nephromyces are not actually fungi, but instead constitute a group within the Apicomplexa that is related to the Piroplasmida.
Species of Nephromyces
Nephromyces molgularum Giard, 1888
Nephromyces rosocovitanus Giard, 1888
Nephromyces sorokini Giard, 1888
Description
Nephromyces is found in the lumen of the renal sac of its host animals. The renal sac is a closed, fluid-filled structure that is derived from the epicardium during development. There are different cell types (at least seven in Nephromyces from Molgula manhattensis) which appear to be different life cycle stages, as the different types appear in a consistent sequence after initial infection of the host animal. However, in a mature infection, different stages simultaneously co-occur in the same host individual. They include filaments (trophic stages), spores, motile but non-flagellated cells, and biflagellated swarmer cells. The non-flagellated motile cells resemble the sporozoites of other apicomplexans, while the spores contain structures that resemble the rhoptries of the apical complex, another typical apicomplexan feature.
Symbiosis
Nephromyces is specific to the family Molgulidae, and has been found in species of Molgula and at least one other molgulid genus, Bostrichobranchus (B. pilularis). Every wild-collected adult Molgula animal examined has been found to contain Nephromyces, suggesting that it is a beneficial symbiont rather than a parasite; this makes Nephromyces an exception among apicomplexans, which are usually parasitic on their animal hosts. However, animals without Nephromyces can be obtained by spawning and raising them in filtered seawater. These symbiont-free animals have been used to study the Nephromyces life cycle. Nephromyces is released into surrounding seawater when its host dies, and cells of Nephromyces can remain alive and infective for at least 29 days outside of a host.
The renal sac organ where Nephromyces lives contains high concentrations of urate, a nitrogenous waste product. Activity of urate oxidase, an enzyme that breaks down urate, has been found in Nephromyces cells, hence they may be using the waste products from their host animal as a nitrogen source for themselves.
Intracellular bacteria have been found within cells of Nephromyces from Molgula manhattensis and M. occidentalis, making this a symbiosis within a symbiosis.
References
Apicomplexa genera
Symbiosis | Nephromyces | [
"Biology"
] | 692 | [
"Biological interactions",
"Behavior",
"Symbiosis"
] |
54,735,866 | https://en.wikipedia.org/wiki/MicroTCA | MicroTCA (short for Micro Telecommunications Computing Architecture, also: μTCA) is a modular, open standard, created and maintained by the PCI Industrial Computer Manufacturers Group (PICMG). It provides the electrical, mechanical, thermal and management specifications to create a switched fabric computer system, using Advanced Mezzanine Cards (AMC), connected directly to a backplane. MicroTCA is a descendant of the AdvancedTCA standard.
History
The rapid expansion of mobile telecommunications and their associated services (such as text messages) at the beginning of the millennium increased the demand of processing power in telecommunication systems. The existing "carrier grade" (see RAS) computing architectures were not fit to house the high performance processors of the time. In order to answer those demands, about 100 companies worked together in PICMG, resulting in the Advanced Telecommunications Architecture (AdvancedTCA, ATCA), published in 2002.
After the introduction of AdvancedTCA, a standard was developed, to cater towards smaller telecommunications systems at the edge of the network. This standard was geared towards a more compact, less expensive systems, without cutting back on reliability or data throughput. This standard, called MicroTCA, was ratified 2006.
MicroTCA systems migrated after its release into non-telecommunication sectors, like defence, avionics and science. This resulted in extensions to the base-standard, called modules.
Modules
MicroTCA.0
The base-specification for properties common to all other modules, ratified July 6, 2006. This includes:
Mechanical specifications, like possible dimensions of card cages, backplanes and supported AMC-modules
Electrical specifications, like power distribution and interface layout
Thermal specifications, like possible cooling layouts or available cooling power
Management specifications
A second revision of the base-specifications was ratified January 16, 2020, containing some corrections, as well as alterations, necessary to implement higher speed Ethernet fabrics, like 10GBASE-KR and 40GBASE-KR4.
MicroTCA.1
This module adds specifications for ruggedized systems, using forced air for cooling. Possible scenarios for MicroTCA.1-based systems include outside plant telecom, industrial and aerospace environments
MicroTCA.2
This module adds specifications for more stringent requirements with regards to temperature, shock, vibration and other environmental conditions. These specifications are geared towards use in outside plant telecom, machine and transport industry, as well as military airborne, shipboard and ground mobile equipment. MicroTCA.2 allows the use of air- and conduction-cooled AMC-modules.
MicroTCA.3
This module adds specifications for even more stringent requirements with regards to temperature, shock, vibration and other environmental conditions. These specifications are geared towards use in outside plant telecom, machine and transport industry, as well as military airborne, shipboard and ground mobile equipment. MicroTCA.3 requires the use of conduction-cooled AMC-modules.
MicroTCA.4
This module extends the AMC with a Rear Transition Module (RTM), increasing PCB-space and modularity. AMC and RTM are connected with a connector, located in zone 3, defined in MicroTCA.0. These specifications are geared towards use in large-scale scientific devices, like particle accelerators or telescopes.
Components of MicroTCA
Card Cage
The card cage (also: shelf, crate) houses all the other components and as such has two primary functions:
Provide mechanical stability to the other components
Ensure sufficient cooling
There exist a wide array of card cages. They usually differ in:
the type of modules they support (MTCA.0, MTCA.1, ...)
the number of slots they provide (typically between 2 and 12)
the architecture of the installed backplane (see below)
the cooling scheme they use (i.e. airflow front-to-back, bottom-to-top, side-to-side, conductive,...)
Backplane
The backplane is a printed circuit board, mounted directly into the card cage. It connects all other components of a MicroTCA system to each other and provides power, data access and management access to them.
Two types of power are distributed over the backplane, Management Power (+3.3 V) and Payload Power (+12 V). Unlike typical backplanes, where power is distributed to all components via a common "powerplane" in the PCB, on a MicroTCA backplane, Management and Payload Power are distributed to each component individually. While Management Power is provided to each module connected to a powered backplane, Payload Power has to be granted by the MicroTCA Carrier Hub (MCH), after ensuring that the module is MicroTCA-compatible.
The standard defines various communication buses, which the backplane can/should provide:
Gigabit Ethernet
IPMI
SATA
Fat pipe (can be used for PCIe, SRIO or 10G/40G Ethernet)
Point to Point Links
Clocks
JTAG
Cooling Unit
The Cooling Unit (CU) provides controlled air flow in air-flow-cooled card cages. It usually consists of an array of fans and a controller, which is connected to the backplane. The MicroTCA Carrier Hub (MCH) can read-out temperature sensors (if present) and fan speed, as well as change fan speed via IPMI. The Cooling Unit is usually fitted to a specific card cage. Some CUs are easily detachable (i.e. for cleaning or replacement), while other card cages come with integrated, non-detachable CUs.
Power Module
The Power Module (PM, also: Power Supply) converts the AC power from the power line to the +3.3 V Management Power (MP) and +12 V Payload Power (PP), both of which are DC. There exist a variety of power modules, which differ in:
form factor (i.e. double width, single width)
input voltage (110 V, 220 V, both)
output power (i.e. 600 W, 1000 W)
The power module senses the presence of a module in a slot via a specified pin in the module connector, and immediately provides that module with management power. Payload power is managed by the MicroTCA Carrier Hub (MCH), which communicates with the power module via IPMI.
The power module uses its own type of connector, and can thus only be installed into designated slots, which in turn can't carry any other type of module. Some card cages provide an additional power module slot for redundancy. In such a case, one slot is the primary, which will provide power by default, and the other one is secondary, providing power only, if the primary does not.
MicroTCA Carrier Hub
The MicroTCA Carrier Hub (MCH) is the central managing device of a MicroTCA card cage. It manages power distribution and cooling. It usually also provides Gigabit Ethernet and/or PCIe/Serial RapidIO switching. Some MCHs additionally provide clocking. As the name indicates, they are the hub of various star topologies (i.e. for Ethernet, PCIe) on the backplane and thus require dedicated slot(s). Some backplanes support two MCHs for redundancy. In this case there are two MCH slots, with one being designated primary, and one secondary.
Advanced Mezzanine Card
Advanced Mezzanine Card (AMC) is a standard for hot-plugable PCBs. It was originally developed to be used in AdvancedTCA systems. The standard specifies:
the dimensions of the PCB with two width variants (single, double) and three height variants (Compact, Mid-size, Full)
type, location and orientation of connectors (i.e. Zone 1, 2, 3)
There is a huge variation of functionalities, an AMC can fulfill:
Computing (i.e. a module with CPU, RAM, SSD and on-board graphics)
Storage (i.e. SSD carrier)
Graphics card
FPGA card (i.e. for signal processing)
FMC carrier
Digitizer card (Analog-Digital and Digital-Analog Conversion)
Clocking and Triggering
and others
Rear Transition Module (MTCA.4 only)
The Rear Transition Module (RTM) was added in the MicroTCA.4 standard. It is connected directly to an AMC via a connector, located in zone 3, requiring a double width AMC and RTM. An RTM has about the same dimensions, as an AMC, basically doubling the available PCB-space per slot in an MTCA.4 card cage. Its power is provided by the AMC. Thus an RTM can not operate on its own, but requires a paired AMC.
The zone 3 connector is electrically free configurable, making it possible, that a mechanically fitting AMC-RTM pair is electrically incompatible. To avoid damage due to that incompatibility, a mechanical code-pin was added to MTCA.4-compatible AMCs and RTMs, mechanically preventing the installation of an electrically incompatible RTM to an AMC.
The functionality of RTMs includes, but is not limited to:
RF-signal pre-/post-processing (i.e. filtering, Up-/Down-conversion, Vector De-/Modulation)
Digital signal pre-/post-processing
Clock-generation/-distribution
Device interfaces
Date storage
CPU (only MCH-RTM)
References
External links
MicroTCA.0 Standard Short Form
Helmholtz Innovation Lab at DESY, centered around MicroTCA: MicroTCA Technology Lab
Technical specifications
Telecommunications
PICMG standards | MicroTCA | [
"Technology"
] | 1,960 | [
"Information and communications technology",
"Telecommunications",
"nan"
] |
54,736,630 | https://en.wikipedia.org/wiki/NGC%204473 | NGC 4473 is an elliptical galaxy located about 50 million light-years away in the constellation of Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784. NGC 4473 has an inclination of about 71°. NGC 4473 is a member of a chain of galaxies called Markarian's Chain which is part of the larger Virgo Cluster of galaxies.
Globular clusters
NGC 4473 has an estimated population of 376 ± 97 globular clusters. The clusters may have formed from the result of multiple minor mergers that helped form the outer regions of the galaxy.
Counter–rotating features
NGC 4473 has two counter-rotating stellar discs embedded in the inner regions of the galaxy. They may have formed from the accretion of gas from outside the galaxy, or by the mergers of gas-rich galaxies.
Supermassive black hole
Using the HST and spectroscopic data from the ground to measure the motions of stars in the center of the galaxy, Douglas Richstone and colleagues at the University of Michigan have concluded that NGC 4473 has a supermassive black hole with an estimated mass of roughly 100 million solar masses (). Its diameter is estimated to be around 4.459 astronomical units (415 million mi).
See also
List of NGC objects (4001–5000)
Messier 87
M86
NGC 4550 - Lenticular galaxy in the Virgo Cluster experiencing counter-rotation
Gallery
References
External links
Elliptical galaxies
Coma Berenices
4473
Virgo Cluster
41228
7631
Astronomical objects discovered in 1784 | NGC 4473 | [
"Astronomy"
] | 321 | [
"Coma Berenices",
"Constellations"
] |
54,737,270 | https://en.wikipedia.org/wiki/WASP-121b | WASP-121b, formally named Tylos, is an exoplanet orbiting the star WASP-121. WASP-121b is the first exoplanet found to contain water in an extrasolar planetary stratosphere (i.e., an atmospheric layer in which temperatures increase as the altitude increases). WASP-121b is in the constellation Puppis, and is about 858 light-years from Earth.
Nomenclature
In August 2022, this planet and its host star were included among 20 systems to be named by the third NameExoWorlds project. The approved names, proposed by a team from Bahrain, were announced in June 2023. WASP-121b is named Tylos after the ancient Greek name for Bahrain, and its host star is named Dilmun after the ancient civilization.
Characteristics
WASP-121b is an ultra-hot Jupiter exoplanet with a mass about 1.16 times that of Jupiter and a radius about 1.75 times that of Jupiter. The exoplanet orbits WASP-121, its host star, every 1.27 days.
In 2019 a work by Hellard et al. discussed the possibility of measuring the Love number of transiting hot Jupiters using HST (Hubble Space Telescope)/STIS. A tentative measurement of for WASP-121b was published in the same work.
The planetary orbit is inclined to the equatorial plane of the star by 8.1°.
Atmospheric composition
A spectral survey in 2015 attributed , hot stratosphere absorption bands to water molecules, titanium(II) oxide (TiO) and vanadium(II) oxide (VO). Neutral iron was also detected in the stratosphere of WASP-121b in 2020, along with neutral chromium and vanadium. The detection claims of TiO and VO have since been disproved.
Reanalysis of collected spectral data was published in June 2020. Neutral magnesium, calcium, vanadium, chromium, iron, and nickel, along with ionized sodium atoms, were detected. However the low quality of available data precluded a positive identification of any molecular species, including water. The atmosphere appears to be significantly out of chemical equilibrium and possibly escaping. The strong atmospheric flows beyond the Roche lobe, indicating ongoing atmosphere loss, were confirmed in late 2020.
In 2021, the planetary atmosphere was revealed to be slightly more blue and less absorbing, which may be an indication of planetary weather patterns. By mid-2021, the presence of ions of iron, chromium, vanadium and calcium in the planetary atmosphere was confirmed. In 2022, ionized barium was also detected. By 2022, an absence of titanium in the planetary atmosphere was confirmed and attributed to the nightside condensation of highly refractory titanium dioxide.
Observations by HST from 2016-2019, published in 2024, confirmed variability in the atmosphere of WASP-121b.
Possible exomoon
The sodium detected via absorption spectroscopy around WASP-121b is consistent with an extrasolar gas torus, possibly fueled by a hidden exomoon resembling Io moon.
See also
List of exoplanet firsts
List of exoplanets discovered in 2015, including WASP-121b
SuperWASP
WASP-33b, another ultra-hot Jupiter
References
External links
SuperWASP Wide Angle Search for Planets: The Planets, SuperWASP.
Exoplanets discovered by WASP
Exoplanets discovered in 2015
Puppis
Hot Jupiters
Exoplanets with proper names | WASP-121b | [
"Astronomy"
] | 718 | [
"Puppis",
"Constellations"
] |
54,737,840 | https://en.wikipedia.org/wiki/3%CF%89-method | The 3ω-method (3 omega method) or 3ω-technique, is a measurement method for determining the thermal conductivities of bulk material (i.e. solid or liquid) and thin layers. The process involves a metal heater applied to the sample that is heated periodically. The temperature oscillations thus produced are then measured. The thermal conductivity and thermal diffusivity of the sample can be determined from their frequency dependence.
Theory
The 3ω-method can be accomplished by depositing a thin metal structure (generally a wire or a film) onto the sample to function as a resistive heater and a resistance temperature detector (RTD). The heater is driven with AC current at frequency ω, which induces periodic joule heating at frequency 2ω (since ) due to the oscillation of the AC signal during a single period.
There will be some delay between the heating of the sample and the temperature response which is dependent upon the thermal properties of the sensor/sample. This temperature response is measured by logging the amplitude and phase delay of the AC voltage signal from the heater across a range of frequencies (generally accomplished using a lock-in-amplifier).
Note, the phase delay of the signal is the lag between the heating signal and the temperature response. The measured voltage will contain both the fundamental and third harmonic components (ω and 3ω respectively), because the Joule heating of the metal structure induces oscillations in its resistance with frequency 2ω due to the temperature coefficient of resistance (TCR) of the metal heater/sensor as stated in the following equation:
,
where C0 is constant. Thermal conductivity is determined by the linear slope of ΔT vs. log(ω) curve. The main advantages of the 3ω-method are minimization of radiation effects and easier acquisition of the temperature dependence of the thermal conductivity than in the steady-state techniques. Although some expertise in thin film patterning and microlithography is required, this technique is considered as the best pseudo-contact method available. (ch23)
The process was first published by David Cahill and Robert Pohl in the April 1987 issue of the Physical Review in a paper titled "Thermal Conductivity of Amorphous Solids above the Plateau".
References
Materials testing
Heat conduction | 3ω-method | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 476 | [
"Materials testing",
"Heat conduction",
"Thermodynamics",
"Materials science"
] |
54,739,499 | https://en.wikipedia.org/wiki/List%20of%20sex-hormonal%20medications%20available%20in%20the%20United%20States | List of sex-hormonal medications available in the United States may refer to:
List of androgens/anabolic steroids available in the United States
List of estrogens available in the United States
List of progestogens available in the United States
See also
List of combined sex-hormonal preparations
List of steroids
List of steroid esters
References
Steroids
Sex-hormonal medications available in the United States | List of sex-hormonal medications available in the United States | [
"Chemistry"
] | 90 | [
"nan"
] |
54,740,174 | https://en.wikipedia.org/wiki/Bioinformatics%20Institute%20%28Singapore%29 | The Bioinformatics Institute (Abbreviation: BII) is one of the Biomedical Sciences Institutes of the Agency for Science, Technology and Research, (A*STAR). BII was originally founded in 2001 by Dr Rajagopal as a support unit for Bioinformatics and IT service management. However, since August 2007, it has been redefined as a biological research organisation upon the arrival of the current executive director, Dr Frank Eisenhaber. BII focuses on "computationally biology-driven life science research aimed at the discovery of biomolecular mechanisms."
BII also develops computer based research tools and performs experimental verifications in its own experimental facilities or by collaborating with appropriate groups.
BII is home to the journal Scientific Phone Apps and Mobile Devices with SpringerNature.
There are currently four research divisions in BII:
Biomolecular Sequence to Function
Biomolecular Modelling and Design
Imaging Informatics
Translational Research
Under Dr. Sebastian Maurer-Stroh, the team at BII quality-checked genomic sequences uploaded by various countries to the GISAID database that stores and shares COVID-19 virus data.
External links
References
Genetics or genomics research institutions
Bioinformatics
Research institutes in Singapore | Bioinformatics Institute (Singapore) | [
"Engineering",
"Biology"
] | 253 | [
"Bioinformatics",
"Biological engineering"
] |
54,740,937 | https://en.wikipedia.org/wiki/Late%20acceptance%20hill%20climbing | Late acceptance hill climbing, created by Yuri Bykov in 2008 is a metaheuristic search method employing local search methods used for mathematical optimization.
References
Metaheuristics | Late acceptance hill climbing | [
"Technology"
] | 37 | [
"Computing stubs",
"Computer science",
"Computer science stubs"
] |
54,741,842 | https://en.wikipedia.org/wiki/Nanoparticle%20deposition | Nanoparticle deposition refers to the process of attaching nanoparticles to solid surfaces called substrates to create coatings of nanoparticles. The coatings can have a monolayer or a multilayer and organized or unorganized structure based on the coating method used. Nanoparticles are typically difficult to deposit due to their physical properties.
Challenges
Nanoparticles can be made from different materials such as metals, ceramics and polymers. The stability of the nanoparticles can be an issue as nanoparticles have a tendency to lower their very high surface energy, which originates from their high surface-to-bulk ratio. Bare nanoparticles tend to stabilize themselves either by sorption of molecules from the surroundings or by lowering the surface area through coagulation and agglomeration. Usually the formation of these aggregates is unwanted. The tendency of a nanoparticle to coagulate can be controlled by modifying the surface layer. In a liquid medium, suitable ligand molecules are commonly attached to the nanoparticle surface, as they provide solubility in suitable solvents and prevent coagulation.
Deposition methods
There are multiple different coating methods available to deposit nanoparticles. The methods differ by their ability to control particle packing density and layer thickness, ability to use different particles and the complexity of the method and the instrumentation needed.
Langmuir-Blodgett
In the Langmuir-Blodgett method, the nanoparticles are injected at air-water interphase in a special Langmuir-Blodgett Trough. The floating particles are compressed closer to each other with motorized barriers which allow to control the packing density of the particles. After compressing the particles to the desired packing density, they are transferred on a solid substrate using vertical (Langmuir-Blodgett) or horizontal (Langmuir-Schaefer) dipping to create a monolayer coating. Controlled multilayer coatings can be made repeating the dipping procedure multiple times.
The benefits of the Langmuir-Blodgett method include a firm control over the packing density and the layer thickness achieved that have been shown to be better than with other methods, the ability to use different shapes and materials of substrates and particles and the possibility to characterize the particle layer during deposition for example a Brewster Angle Microscope. As a disadvantage, a successful Langmuir-Blodgett deposition requires optimization of multiple measurement parameters such as dipping speed, temperature and dipping packing density.
Dip coating and spin coating
The spin and dip coating methods are simple methods for nanoparticle deposition. They are useful tools especially in creating self-assembled layers and films where the packing density isn't critical. Accurate and vibration-free sample withdrawal speeds can be used to have control over the film thickness. Creating high density monolayers is typically very difficult since the methods are lacking the packing density control. Also, the volume of nanoparticle suspension required for both spin coating and dip coating is rather big which may be an issue when using expensive nanoparticle materials.
Other methods
Other possible deposition methods include methods utilizing particle self-assembly by solvent evaporation, doctor blade, chemical vapor deposition and transfer printing. Some of these methods like solvent evaporation are extremely simple but produce low-quality films. Other methods such as the chemical vapor deposition are effective for certain types of particles and substrates but are limited in particle types that can be used and require heavier instrumentation investments. Also hybrid methods such as combining self-assembly to Langmuir-Blodgett have been used.
Nanoparticle coating applications
Coatings and thin films made from nanoparticles are being used in various applications including displays, sensors, medical devices, energy storages and energy harvesting. Examples include
Using graphene oxide for applications in electronics
Using nanoparticles of metal oxides, carbon nanotubes and quantum dots in photovoltaics, displays and sensors
Using polymers and nanocomposites in nanolithographic patterning
Using nanoparticles to scatter light, creating new optical effects
See also
Langmuir-Blodgett
Dip coating
Spin coating
Nanoparticle
External links
Pdf: Fabricating Highly Organized Nanoparticle Thin Films
References
Nanoparticles
Coatings | Nanoparticle deposition | [
"Chemistry"
] | 877 | [
"Coatings"
] |
54,742,155 | https://en.wikipedia.org/wiki/Karun%20Thapa | Karun Thapa (Nepali: करुण थापा) born on 23 March 1965) is a Nepali IT expert, film editor, 3D animator, trainer, a well-known lyricist and Ghazal writer. Karun is known for his technological contribution to Nepali IT and media industry. He has contributed by introducing Devanagari fonts in computers, introducing AVID Digital Film Editing system in Nepal and introducing 3D animation in Nepal.
Early life and education
Karun Thapa was born in 1965 (BS 2022) in Beni to a Hindu family. Karun studied till class 3 in his village school called Dhaulagiri School. He stood first in Myagdi district in a scholarship exam, got scholarship and went to Budhanilkantha School in Kathmandu. After completing high school from Budhanilkantha School, Karun went to Amrit Science College (ASCOL) to complete his intermediate in science and graduation in Computer Science from Priyadarshini College.
Career
Karun Thapa started his career a software developer and a computer trainer. He started making business software for hotels, banks, business companies, etc. and started a computer training institute in 1988.
Thapa was the first person to develop Nepali (Devanagari) font on Apple IIe and Apple Macintosh computers. UNESCO nominated Thapa to participate in the Asian Federation of Natural Language Processing (AIT, Bangkok) 1992 and the Asia Pacific Regional Seminar on Information Technology and Newspaper Publishing in Madras (from 11–14 April 1995) in recognition to the font development done by him. He also developed Limbu (Srijunga) Script and Rai (Wambule Script) in 1994. He is mentioned in the history section in a book called History, Culture and Customs of Sikkim (J. R. Subba). Thapa introduced 3D animation in Nepal and he is the first 3D animator in Nepal.
Karun Introduced AVID film editing and digital cinema in Nepal.
Filmography
Awards
Winner
Achievements
Honours
Served as Jury Member
Jury Member for the following
References
External links
Living people
1965 births
20th-century engineers
20th-century male artists
20th-century Nepalese artists
20th-century Nepalese musicians
20th-century Nepalese male writers
20th-century songwriters
21st-century engineers
21st-century male artists
21st-century Nepalese artists
21st-century Nepalese musicians
21st-century Nepalese male writers
21st-century songwriters
Ghazal
Male songwriters
Musicians from Kathmandu
Nepalese animators
Nepalese engineers
Nepalese film editors
Nepalese lyricists
People from Myagdi District
Software engineers
Tribhuvan University alumni
Writers from Kathmandu | Karun Thapa | [
"Engineering"
] | 527 | [
"Software engineering",
"Software engineers"
] |
54,742,283 | https://en.wikipedia.org/wiki/NGC%202539 | NGC 2539 is an open cluster in the constellation Puppis, located at the north edge of the constellation. It was discovered by William Herschel on January 31, 1785. It is a moderately rich cluster and with little central concentration, with Trumpler class II1m.
Characteristics
The diameter of the cluster based on the location of possible members is estimated to be 7.4 parsecs (24 light years). The core radius of the cluster is 1.98 parsecs (6.5 light years), while the tidal radius is 15.2 parsecs (50 light years) and represents the average outer limit of NGC 2539, beyond which a star is unlikely to remain gravitationally bound to the cluster core.
151 stars, probable members of the cluster, are located within the central part of the cluster and 455 probable members are located within the angular radius of the cluster. 19 Puppis, visible near the edge of the cluster is a foreground star. The turn-off mass of the cluster is at 3.1 . The metallicity of the cluster is 0.14, higher than the solar one. The age of the cluster has been estimated to be as high as 630 myrs.
Mermilliod and Mayor studied 11 red giants within the cluster, the brightest of which was mag 9.509 and of spectral type K5I-II, and two non-members. Three of this stars were found to be spectrographic binaries, while further studies indicated that one of them is a triple system. Two more are suspected double stars. Further studies revealed seven variable stars, 5 eclipsing binaries, one delta Scuti variable and one gamma Doradus variable, with the gamma Doratus variable star membership being questionable. From the eclipsing binaries, one is field star and in a further study one more eclipsing binary (specifically a W Ursae Majoris variable) was found to lie at the background.
References
External links
2539
Puppis
Open clusters | NGC 2539 | [
"Astronomy"
] | 410 | [
"Puppis",
"Constellations"
] |
76,262,220 | https://en.wikipedia.org/wiki/Zodletone%20Mountain | Zodletone Mountain (with spelling variant Zadletone Mountain, occasionally also called Mount Zodletone) is a mountain in the United States. It is located in eastern Kiowa County just west of neighboring Caddo County in the southwestern part of the state of Oklahoma (about 120 miles from Oklahoma City). On the northern slope of the mountain is the sulfide-rich and strictly anaerobic artesian Zodletone Spring with a National Science Foundation (NSF) microbial observatory.
Description
Zodletone Mountain rises approximately 500 meters (or 1640 feet) above sea level and 75 meters (or 229 feet) above the surrounding terrain. At its base, the mountain is approximately 1.9 kilometers (or 1.18 miles) wide. Located in the Anadarko Basin, the land surrounding Zodletone Mountain is predominantly flat. As a result, the mountain is a prominent feature in the landscape. It is nearly entirely encircled by grassland and several lakes are situated in the region. Zodletone Mountain is the northernmost link of the Slick Hills Range. The highest point in the area is Bally Mountain, which stands at 1866.8 feet above sea level and is located 2.73 miles south of Mount Zodletone. The population density of Zodletone Mountain is very low, with only about 2 inhabitants per square kilometer (247.105 acres). The ZIP Code delivery area is OK 73062. The nearest major city, Carnegie, is located 8.88 miles northeast of Zodletone Mountain.
Climate
The climate in this region is humid and subtropical, with an average temperature of 18°C/64.4°F. The hottest month is July, with 32°C/89.6°F average, while the coldest is January, with an average temperature of 2°C/35.6°F. The average annual rainfall is 783 millimeters/30.826 inches, with the wettest month being April, with 104 millimeters/4.094 inches of rain, and the driest being January, with only 25 millimeters/0.984-inch.
Directions
Follow Oklahoma 58 south of Carnegie for 6.83 miles. Then, turn west on a dirt road for 2.98 miles and continue south for about half a mile until you reach a white two-story farmhouse to obtain a visitor's permit (as of 1988).
Zodletone Spring
Located on the northern slope of Mount Zodletone, the Zodletone Spring is an artesian spring that features a National Science Foundation (NSF) microbial observatory. First described by Havens in 1983, the spring is a sulfide-rich and strictly anaerobic hydrocarbon seep that operates at low temperatures. The spring discharges approximately 2.11 gallons per minute over a distance of about 22 yards, where the water flows north over Stinking Creek into nearby Saddle Mountain Creek. The spring is a closed area of approximately 1 square meter filled with biomass and soft sediments to a depth of at least 6 inches. The spring water has a sulfide content of 8–10 mmol/L and contains 1.0–1.5 mmol of zero valent sulfur. The salinity, measured by the concentration of sodium chloride, is around 0.7–1.0%, which is significantly less than seawater (approximately 3.5%). These measurements, in the mats formed by the microbes, increase to 2–5%, and in the soil they can reach up to 25–30% at a depth of 2 in and 12 in, respectively. The hydrocarbons detected in high concentrations are short-chain alkanes, such as methane, ethane, and propane.
Since 2001, a team of scientists from the University of Oklahoma (OU) and Oklahoma State University (OSU) has been researching the microbial community (microbiome) at the Zodletone spring.
This spring is an intriguing research site for geologists and environmental microbiologists due to a variety of factors. The high sulfide and methane content of the spring water creates a diverse microbial mat environment along its course down the mountain, displaying unique geochemical and microbial processes.
A list of the minerals encountered there can be found at mindat.org. This environment shares many similarities with the conditions that existed on Earth almost two billion years ago when there was no oxygen in the atmosphere, and methane was abundant. Frequent sulfur reactions were likely to have occurred. Therefore, the spring and spring stream ecosystem provides an opportunity to study the biology and geochemistry of early Earth. Therefore, the investigations focus on the role of microorganisms, particularly bacteria and archaea, in hydrocarbon (petroleum) and sulfur metabolism, as well as micro-eukaryotes (eukaryotic microbes such as protists and microfungi).
Bacteria
Both known and new groups of bacteria were identified in the sample. These groups include Chlorobia (green sulfur bacteria), Chloroflexi (green non-sulfur bacteria), Planctomycetes (with isolate Zi62), Cyanobacteria (specifically order Oscillatoria), Saccharibacteria (formerly known as TM7, here with extremely high diversity), Parcubacteria (also known as OD1, with isolate ZFos45e05), the Microgenomates group (OP11), and Absconditabacteria (SR1). In addition, new bacterial phyla, Candidate division CSSED10-310 (provisional name), with its species Candidate division CSSED10-310 bacterium, and Ca. Krumholzibacteriota, with its species Ca. K. zodletonense, were found in the spring.
Archaea
Among the Archaea, Crenarchaeota were found in addition to an unexpected occurrence of Halobacteria (Euryarchaeota) in several places in spring, despite the fact that the water salinity is too low for them (although not in the mats and soil, as seen above). The following were identified:
the genera Haloferax (with species H. sulfurifontis) and Halogranum from the order Haloferacales;
the genera Haladaptatus (with species H. paucihalophilus) and Halosarcina from the order Halobacteriales.
Another archaeal group found at Zodleton Spring is that of the Asgard archaea, including:
AMARA-1 sp016933055 (GTDB) with Ca. Lokiarchaeota archaeon isolate Zod_Metabat.1044 (NCBI);
Ca. Thorarchaeota archaeon isolate Zod_maxbin.0292; MAG: Candidatus Krumholzibacterium zodletonense isolate 171, whole genome shotgun sequencing project;
Ca. Heimdallarchaeota archaeon isolate Zod_Metabat.460.
Asgard archaea, particularly the Heimdall archaea, are considered potential candidates for illustrating the origin in the evolution of complex cellular organisms, or eukaryotes, in a process known as eukaryogenesis.
Protists and microfungi
The study unequivocally identified several protist groups, such as Cercozoa, Alveolata, and Stramenopile, among the microbial eukaryotes. The majority of the stramenopiles were classified as either belonging to the genus Cafeteria (order Bicosoecida) or the order Labyrinthulida (mucilages), despite their previous association with marine habitats.
The majority of the fungal sequences observed belong to ascomycete yeasts of the Saccharomycetales order or are closely related to basidiomycete yeasts from the Tremellales order. In addition, they found sequences from one of the Ustilaginomycetes (fire fungi) and a new group of fungi provisionally designated as LKM (also known as Zeuk1), named after the strain LKM11 from Lac Pavin (France).
Viruses
As of mid-January 2023, research on the Viruses in the Zodletone Spring ecosystem is still limited. However, the RNA sequence EMS013, which possibly belongs to the genus Cystovirus, along with two other examples, suggest the presence of RNA bacteriophages. The presence of protists from the genus ’’Cafeteria’’ suggests the possibility of the presence of accompanying viruses, such as the DNA giant virus [[Cafeteria roenbergensis virus|Cafeteria roenbergensis virus’’ (CroV)]].
Bibliography
.
Elshahed, Mostafa S.; Senko, John M.; Najar, Fares Z.; Kenton, Stephen M.; Roe, Bruce A.; Dewers, Thomas A.; Spear, John R.; Krumholz, Lee R. (September 2003). "Bacterial Diversity and Sulfur Cycling in a Mesophilic Sulfide-Rich Spring". Applied and Environmental Microbiology. 69 (9): 5609–5621. doi:10.1128/AEM.69.9.5609-5621.2003.
Elshahed, Mostafa S.; Youssef, Noha H.; Luo, Qingwei; Najar, Fares Z.; Roe, Bruce A.; Sisk, Tracy M.; Bühring, Solveig I.; Hinrichs, Kai-Uwe; Krumholz, Lee R. (August 2007). "Phylogenetic and Metabolic Diversity of Planctomycetes from Anaerobic, Sulfide- and Sulfur-Rich Zodletone Spring, Oklahoma". Applied and Environmental Microbiology. 73 (15): 4707–4716. doi:10.1128/AEM.00591-07.
Hahn, C. Ryan; Farag, Ibrahim F.; Murphy, Chelsea L.; Podar, Mircea; Elshahed, Mostafa S.; Youssef, Noha H. (2022-04-26). Sousa, Filipa L.; Schleper, Christa M. (eds.). "Microbial Diversity and Sulfur Cycling in an Early Earth Analogue: From Ancient Novelty to Modern Commonality". mBio. 13 (2). doi:10.1128/mbio.00016-22.
Krishnamurthy, Siddharth R.; Janowski, Andrew B.; Zhao, Guoyan; Barouch, Dan; Wang, David (24 March 2016). "Hyperexpansion of RNA Bacteriophage Diversity". PLOS Biology. 14 (3): e1002409. doi:10.1371/journal.pbio.1002409.
Luo, Qingwei; Krumholz, Lee R.; Najar, Fares Z.; Peacock, Aaron D.; Roe, Bruce A.; White, David C.; Elshahed, Mostafa S. (October 2005). "Diversity of the Microeukaryotic Community in Sulfide-Rich Zodletone Spring (Oklahoma)". Applied and Environmental Microbiology. 71 (10): 6175–6184. doi:10.1128/AEM.71.10.6175-6184.2005. ISSN 0099-2240.
Lynch, Erin A.; Langille, Morgan G. I.; Darling, Aaron; Wilbanks, Elizabeth G.; Haltiner, Caitlin; Shao, Katie S. Y.; Starr, Michael O.; Teiling, Clotilde; Harkins, Timothy T.; Edwards, Robert A.; Eisen, Jonathan A.; Facciotti, Marc T. (2012-07-24). "Sequencing of Seven Haloarchaeal Genomes Reveals Patterns of Genomic Flux". PLOS ONE. 7 (7): e41389. doi:10.1371/journal.pone.0041389. ISSN 1932-6203.
Savage, Kristen N.; Krumholz, Lee R.; Gieg, Lisa M.; Parisi, Victoria A.; Suflita, Joseph M.; Allen, Jon; Philp, R. Paul; Elshahed, Mostafa S. (2010-03-19). "Biodegradation of low-molecular-weight alkanes under mesophilic, sulfate-reducing conditions: metabolic intermediates and community patterns: n-Propane and n-pentane degradation by sulfate reducers". FEMS Microbiology Ecology. 72 (3): 485–495. doi:10.1111/j.1574-6941.2010.00866.x.
Spain, Anne M.; Elshahed, Mostafa S.; Najar, Fares Z.; Krumholz, Lee R. (2015-09-22). "Metatranscriptomic analysis of a high-sulfide aquatic spring reveals insights into sulfur cycling and unexpected aerobic metabolism". PeerJ. 3: e1259. doi:10.7717/peerj.1259. ISSN 2167-8359.
Yadav, Archana; Hahn, C. Ryan; S. Elshahed, Mostafa; H. Youssefa, Noha (1 July 2021). "Five Metagenome-Assembled Genomes of the Rare Phylum CSSED10-310 from Zodletone Spring (Oklahoma, USA)". Microbiology Resource Announcement''. 10 (26).
Notes
References
External links
Zodletone Mountain (Kiowa) Map, Weather and Photos. Getamap.net
Zodletone Mountain Panorama. PeakVisor
National Science Foundation
State of Oklahoma
Kiowa County
University of OklahomaMicrobial Ecology and Environmental Genomics Laboratory
Oklahoma State University
Mostafa Elshahed, Michael Morrison: Microbial Ecology and Environmental Genomics Laboratory.
Suzanne Coveley, Mostafa S. Elshahed, Noha H. Youssef: Response of the rare biosphere to environmental stressors in a highly diverse ecosystem (Zodletone spring, OK, USA). In: PeerJ, Band 3, e1182, 20. August 2015; doi:10.7717/peerj.1182.
GeoNames
Landforms of Kiowa County, Oklahoma
Microbiology
Ecology | Zodletone Mountain | [
"Chemistry",
"Biology"
] | 3,029 | [
"Microbiology",
"Ecology",
"Microscopy"
] |
76,263,052 | https://en.wikipedia.org/wiki/NGC%20730 | NGC 730 is a star located in the Pisces constellation discovered on 7 November 1885, appearing around the celestial equator being partially visible to both hemispheres during specific times of the year.
See also
List of NGC objects (1–1000)
Pisces (constellation)
References
0730
Pisces (constellation)
Astronomical objects discovered in 1885 | NGC 730 | [
"Astronomy"
] | 70 | [
"Pisces (constellation)",
"Constellations"
] |
76,266,658 | https://en.wikipedia.org/wiki/Why%20Men%20Don%27t%20Iron | Why Men Don't Iron is British three-part documentary series shown on Channel 4 in June 1998, about sex differences in cognition, caused by differences in male-female neurochemistry, and elementary reward systems in the human brain.
Production
The series was produced by Jim Meyer and Anne Moir, and originated by Bill Moir. The titles were made by Triffic Films. It was made by Quality Time Television. The series was first broadcast on 23 June 1998.
A book on the series was published in 1999 by Anne Moir, .
Episodes
Episode 1
Learning the Difference
Amanda Smith, and her husband, tried to overcome biological sex differences with her children, but it never took hold; boys chose mechanical toys, girls chose painting; girls, from an early age, were more conscientious when learning; neurobiologist Roger Gorski conducted sex difference developmental biology experiments with rodents; the congenital adrenal hyperplasia (CAH) condition; a teenage girl has a concentration span of fifteen minutes, a teenage boy has five minutes; a comprehensive secondary school in north Essex, where teenagers are given a psychological test by psychologist Ernie Govier of the University of East London; doctor Bennett Shaywitz and his wife Sally Shaywitz; psychologist Michael O'Boyle of Iowa State University; psychologist Gina Grimshaw and pre-natal testosterone differences; at school, eight times as many boys than girls are expelled; four times as many girls than boys study foreign languages at A-level; former headteacher Alan Davison believed that boys learned differently; teacher Sue Moss; English teacher Jenny Fincken.
Episode 2
The Brain at Work
The two sexes tend to choose much different jobs; the British engineering industry had a fifteen-year campaign to recruit women, with limited, if any, success; engineer Carolina Bartram; her parents nor her teachers scarcely approved of her wanting to become an engineer; nine out of ten nurses are women; Canadian Helen Fisher (anthropologist) believed that women had better people skills; the dichotic listening test; two out of three dentists were men, but nearly all dental nurses are women; 99% of all electricians are men; the UK Giant Vegetable Championships in Spalding, Lincolnshire; only one woman takes part; the Westminster Warriors compete in men's basketball against the Solent Stars; all of the world's top chess players, except one, were men; Fulham F.C. loses to Grimsby Town F.C. 2–0; stock trader Peter Matthews, who raced cars; some men became neurologically addicted to seeking danger, sensation seeking; psychologist Prof Marvin Zuckerman and the neurotransmitters dopamine, linked to direct pleasure seeking, and serotonin, which inhibited recklessness and impulsiveness; men had lower levels of enzyme MAO than women, which biochemically inhibited risk-taking, by regulating the amounts of dopamine and serotonin.
See also
Body Story, also made by Channel 4 in 1998
History of evolutionary psychology
Problem gambling, a risk-taking addiction
References
External links
1998 British television series debuts
1998 British television series endings
1990s British documentary television series
British documentary television series about science
Channel 4 documentary series
Developmental genetics
Documentary television series about neuroscience
Evolutionary psychology
Genetics in the United Kingdom
Sex differences in psychology
Works about genetics
Works about neurochemistry
Works about psychology | Why Men Don't Iron | [
"Chemistry"
] | 679 | [
"Neurochemistry",
"Works about biochemistry",
"Works about neurochemistry"
] |
76,268,064 | https://en.wikipedia.org/wiki/Electrofreezing | Electrofreezing is the tendency of a material to solidify upon being exposed to an external electric field. Electrofreezing was initially introduced by Dufour in 1892. Examples are the electrofreezing of liquid ammonia supposed to be naturally occurring during electrical storms in Jupiter-like planets, and ice χ supposedly being a form of high pressure ice.
Depending on the material, freezing occur only at certain field intensities, above which electric fields are strong enough to induce chemical reactions.
References
Physical phenomena
Phase transitions | Electrofreezing | [
"Physics",
"Chemistry"
] | 103 | [
"Physical phenomena",
"Phase transitions",
"Phases of matter",
"Critical phenomena",
"Statistical mechanics",
"Physical chemistry stubs",
"Matter"
] |
76,268,455 | https://en.wikipedia.org/wiki/Edward%20W.%20Packel | Edward Wesler Packel (born July 23, 1941) is an American mathematician, game theorist, theoretical computer scientist, and expert on the use of Wolfram Mathematica in teaching mathematics. His 1981 book The Mathematics of Games and Gambling won the 1986 Beckenbach Book Prize.
Early life and education
Edward W. Packel was born on July 23, 1941 in Philadelphia, Pennsylvania. His parents were Israel Packel (1907–1987) and Reba Wesler Packel (1909–1995), who had three sons and no daughters. In 1959 Edward Packel matriculated at Amherst College and graduated there in 1963 with a B.A. in mathematics. At Amherst, he played soccer.
In autumn 1963 he became a graduate student at Massachusetts Institute of Technology (M.I.T.), where he graduated in 1967 with a Ph.D. in mathematics. His Ph.D. thesis Some Results on (C0) Semigroups and the Cauchy Problem was supervised by Gilbert Strang .
Career
From 1967 to 1971 Packel was an assistant professor of mathematics at Reed College. As a mathematician on the staff of the Chicago metropolitan area's Lake Forest College, he was an assistant professor from 1971 to 1975, an associate professor from 1975 to 1982, and a full professor from 1982 until his retirement as professor emeritus in 2013. At Lake Forest College, he was director of the computer center from 1972 to 1973 and chair of the department of mathematics and computer science department from 1986 to 1996. At Columbia University he held a part-time appointment as a senior lecturer in computer science from 1983 to 1985. He is the author or co-author of several books and more than 35 refereed articles.
Packel was a visiting associate at California Institute of Technology (Caltech) for the academic year 1977–1978 and again in spring 1980. He held appointments a visiting professor for the academic year 1989–1990 at Berkeley's Mathematical Sciences Research Institute (MSRI), for the academic year 1996–1997 at Australia's University of Sydney, and in autumn 2003 at Harvey Mudd College in Claremont, California. As a consultant, he has taught courses in Mathematica for Wolfram Research, conducted workshops for the Rocky Mountain Mathematics Consortium on consulting for business, and worked on various consultations related to topics related to gambling. His consulting activities related to gambling include probability calculations and computer simulations for new games involving chance, aspects of slot machine developments, and project management for machines that play poker against people.
Personal life and avocations
In May 1968, Edward Packel married Doreen Humphreys. They divorced in 1979 after becoming the parents of three daughters, Amanda, Laura, and Lisa. Laura Packel became an epidemiologist and expert in family planning and reproductive health. In July 1980 Edward Packel married Kathryn Helen Dohrmann, whose father was a Lutheran pastor. There is a son Adrian from Edward Packel's second marriage. At Lake Forest College, Kathryn Dohrmann is an assistant professor of psychology, emerita.
Edward Packel helped to establish the Lake Forest/Lake Bluff Running Club, where he and his wife Kathryn participated together in running. In 2001, Edward set a new record time in the mile run for Illinois runners in his age group. He also enjoys golf — in August 2005 he won $180 at the Lake County Senior Invitational at Lake Bluff Golf Club.
Selected publications
Articles
1983
Books
Writing team: John B. Fink, Bonnie Gold, Robert A. Messer, and Edward W. Packel; xiii+165 pages; illustrated. Book cover & title page at maa.org
References
1941 births
Living people
American computer scientists
American education writers
American gambling writers
20th-century American mathematicians
21st-century American mathematicians
Game theorists
Reed College alumni
Massachusetts Institute of Technology alumni
Reed College faculty
Lake Forest College faculty | Edward W. Packel | [
"Mathematics"
] | 778 | [
"Game theorists",
"Game theory"
] |
76,269,130 | https://en.wikipedia.org/wiki/United%20Nations%20Resource%20Management%20System | The United Nations Resource Management System (UNRMS) is a voluntary global standard for managing natural resources sustainably. It is based on the United Nations Framework Classification for Resources (UNFC). UNRMS aims to support the Sustainable Development Goals (SDGs) by providing a comprehensive framework and methodology for resource progression, policy development, and financing.
Background
UNRMS is a sustainable resource management system developed by the United Nations Economic Commission for Europe (UNECE). It was created to address unsustainable resource supply and use patterns to mitigate environmental and societal impacts while ensuring long-term resource availability. The UNRMS was initiated in 2017 and goes beyond classification, offering a holistic approach to resource management. It promotes technologies for efficient resource discovery, recovery, and processing. The UNRMS is a significant step towards harmonizing economic, environmental, and social objectives in resource utilization.
Objectives and goals
UNRMS is a sustainable management framework that aims to enhance resource efficiency and reduce environmental impact. It is designed to promote a circular economy by considering resources as interconnected elements of a broader ecosystem. The system supports stakeholders in adopting sustainable practices across various resource sectors, contributing to achieving SDGs and ensuring responsible production and use of natural resources for present and future generations.
Framework and methodology
UNRMS framework is based on 12 fundamental principles and 54 requirements. It uses a unique methodology that assesses resources based on their environmental, social, and economic viability, technical feasibility and confidence in estimates. This approach is a sustainable pathway for resource progression, considering its impact on society and the environment. The methodology promotes high-impact technologies for efficient resource discovery, recovery, and processing, intending to advance sustainable resource management practices that can be adapted to various types of resources and geographical contexts.
The fundamental principles of UNRMs are:
State rights and responsibilities in the management of resources
Responsibility to the planet
Integrated management of resources
Social engagement
Service orientation
Comprehensive resource recovery
Value addition
Circularity
Health and safety
Innovation
Transparency
Continuous strengthening of core competencies and capabilities.
Application and coverage
UNRMS extends its application across diverse resources, including minerals, petroleum, renewable energy, nuclear and anthropogenic resources, geological storage and groundwater. It is a versatile tool for stakeholders, encompassing governments, industries, and civil society, to manage resources that align with sustainable development goals. UNRMS's coverage is not limited to isolated sectors but spans a region's entire resource base, promoting an integrated approach to resource management that supports policy development, technological advancement, and sustainable financing.
Various regions have adopted UNRMS to improve the sustainability of their natural resource management, aligning with global sustainability goals and climate agreements. Assessments have demonstrated the effectiveness of the UNRMS by identifying gaps in existing resource management systems and providing actionable recommendations for improvements, thereby proving its utility in enhancing sustainable development practices. UNRMS has proven effective at the sub-national level by providing a comprehensive framework that guides regions in enhancing their resource management systems, leading to improved sustainability and adherence to global environmental standards.
See also
United Nations Framework Classification for Resources
Pan African Resource Reporting Code
References
Minerals
Natural resource management
Petroleum
Renewable energy
Resource economics
Resource extraction
External links
UNRMS in UNECE Website
Environmental standards
United Nations Framework Convention on Climate Change | United Nations Resource Management System | [
"Chemistry"
] | 655 | [
"Petroleum",
"Chemical mixtures"
] |
76,269,454 | https://en.wikipedia.org/wiki/Decauville%20factory%20in%20Aulnay-sous-Bois | The Decauville factory in Aulnay-sous-Bois (previously known as Société Lilloise, or colloquially La Lilloise) produced prefabricated narrow gauge railway track and rolling stock from 1914 to the 1950s in Aulnay-sous-Bois, France.
History
The factory belonged to Etablissements Decauville ainé, a French manufacturer focussing on the production and sales of narrow gauge railway material. It was located on a piece of land that Decauville had acquired in 1914 in the Seine-Saint-Denis department of the Île-de-France region in the north-eastern suburbs of Paris. It focussed on tippers, i.e. V skip railway wagons and roadworthy dump trucks.
The factory was renamed to Société Industrielle d'Aulnay in 1946, enabling the company to win a major contract. At the factory Aulnay the last Decauville steam locomotives were built for the lignite mines of Yugoslavia.
References
Decauville
Dump trucks
Defunct rolling stock manufacturers of France
Aulnay-sous-Bois | Decauville factory in Aulnay-sous-Bois | [
"Engineering"
] | 221 | [
"Engineering vehicles",
"Dump trucks"
] |
76,269,627 | https://en.wikipedia.org/wiki/Puff-puff%20%28onomatopoeia%29 | is an onomatopoeia that conveys a woman's breasts being rubbed in someone's face. It was first coined by Akira Toriyama, creator of Dragon Ball and lead artist of Dragon Quest, both of which featured it. In Dragon Quest, it appears in multiple games as a service a character may receive. It has been featured in a non-sexual way in Dragon Quest as well through methods such as having two Slimes being used to simulate the act, or by swapping the performer for a man, which has been criticized for lacking consent by critics. It has been censored in most games in the Dragon Quest series in English until Dragon Quest XI. Multiple video games in other series include the puff-puff scene or make references to it, including 3D Dot Game Heroes, Yakuza: Like a Dragon, Final Fantasy XIV, and Dragon Ball Xenoverse.
History
Puff-puff is an onomatopoeia for the sound of a woman's breasts being rubbed in another person's face. The term was first used to convey this act by Dragon Ball creator and Dragon Quest artist Akira Toriyama, having been originally featured in the Dragon Ball manga. It was featured in the first Dragon Quest game as a service offered by a woman in the town of Kol in exchange for money. In addition to being a service offered by certain characters, some characters are able to use it as a special technique in battle, such as Jessica Albert from Dragon Quest VIII in order to make enemies "swoon" over her. It was also featured in the mobile game Dragon Quest Walk as a technique.
The "puff-puff" scene has been depicted in the Dragon Quest series in various ways, including women tricking the protagonist. Most puff-puff sessions in the series do not involve women's breasts; in both Dragon Quest II and Dragon Quest III, a woman tricks the player into having it performed by a man. In Dragon Quest VIII, a woman performs a "puff-puff" massage using two Slimes, while Dragon Quest IX: Sentinels of the Starry Skies depicts the character's face being rubbed between two sheep's rear ends. Dragon Quest XI features multiple such scenes, including bungee jumping, a makeup session, and a session where it was performed by a man. The mobile game Dragon Quest Walk features a recreation of the puff-puff scene from the first Dragon Quest. It has also been featured outside Dragon Quest video games, such as a Line sticker and a Puff-Puff Room offered as a reward in a Dragon Quest III-themed escape room.
Censorship
The scene has been censored outside of Japan in multiple Dragon Quest games as well as in Dragon Ball. Dragon Quest III replaces it with a fortune teller, while Dragon Quest IV and Dragon Quest VI changes it to the non-sexual "Pufpuf therapy" and a makeup session respectively. The "Puff-Puff" technique used by Jessica and other characters was changed to be called "Pattycake". When asked by GamesRadar+ about the absence of "puff-puff" scenes from the Dragon Quest series outside Japan, Dragon Quest VI producer Noriyoshi Fujimoto expressed disappointment that these scenes could affect the games' age rating, thus causing them change the scenes to be more subtle in English. The English version of Dragon Quest XI did not have the puff-puff scenes censored.
Impact
The scene has been a running joke in the Dragon Quest series. Inside Games writer Sushishi commented that, since being able to chat with the player's partner characters was not a feature yet by Dragon Quest III, the "puff-puff" scene was a valuable character interaction experience. IGN writer Jared Petty was critical of the depiction of a "puff-puff" scene in Dragon Quest XI where it turns out that a man performed the "puff-puff", arguing that it was not funny and had issues with consent. A writer for The Independent was also critical of its use, feeling that the "puff-puff" scenes in the game were forced in for "cheap, innocuous laughs" and criticized the scene discussed by Jared Petty for similar reasons. Author Daniel Andreyev discussed the various depictions of the act in the series, specifically how it evolved over time and manifested in Dragon Quest XI. He argued that its use contributes to a feeling of nostalgia, particularly for 1980s Japanese pop culture.
It has been referenced in multiple video games, including 3D Dot Game Heroes and Yakuza: Like a Dragon. In Like a Dragon, the game calls it "nigi-nigi", coming from the verb nigiru, meaning to grasp or grip. It is also called "honk-honk" in the sequel Like a Dragon: Infinite Wealth. The "puff-puff" scene is featured in Final Fantasy XIV as part of their Dragon Quest X collaboration. It also appeared in Dragon Ball Xenoverse as a gesture that can be performed by the character Master Roshi. A t-shirt with the words "puff puff" printed on it was released as part of a set of t-shirts by Zozotown, which were based on the Dragon Ball character Bulma.
See also
Cultural impact of Dragon Ball
Notes
References
Anime and manga terminology
Breast
Dragon Ball
Dragon Quest
Japanese sex terms
Onomatopoeia
Sex industry
Video game censorship
Video game terminology
Women-related neologisms | Puff-puff (onomatopoeia) | [
"Technology"
] | 1,094 | [
"Computing terminology",
"Video game terminology"
] |
76,270,623 | https://en.wikipedia.org/wiki/Two%20Hulls%20House | The Two Hulls House is a residential property in Port Mouton, Nova Scotia, Canada. The project was designed by Architect Brian Mackay-Lyons and concluded its construction in 2011.
Context
The form of the Two Hulls House draws inspiration and its name from its two extended pavilions at the front of the building which was designed to resemble the upturned hulls of a boat. Brian Mackay-Lyons' inspiration was acclaimed from his connection with boats as he grew up diverting himself in and around beached boats off the coast of his home in Arcadia. The House consists of courtyards that were designed by Brian to be habitable all year round as they provide protected spaces from the elements. and allow its inhabitants to more easily connect with the homes' natural surroundings.
Architectural design
The building is situated on the edge of a small hill on the coastline of a beach littered with stone till and bedrock. The two hulls of the building are oriented to soar over the glaciated landscape and towards the waterfront.
Layout
The two Cantilevered pavilions of the building are placed asymmetrically as the left hull juts out slightly farther toward the shoreline than the right. The two cantilevered pavilion function as a day and night pavilion. The day pavilion houses rooms such as the Living Room and Office, and the Night pavilion houses the more private spaces such as the bedrooms and bathrooms, and the two pavilions are joined by a foyer that houses more commonly frequented spaces such as the Kitchen.
Structure and material
The house is built with a steel frame and a wooden board cladding with concrete piers. It is built in such a way as to provide an adequate amount of room to prevent any water from high tides or rough waves from reaching and eventually damaging the building. The dual-hull configuration was designed to have it better blend into its environment and complement the maritime feel of the area rather than detract from it.
Sustainability
The intent was to create a sustainable living space. Integrating natural ventilation systems and rainwater harvesting is part of the architectural composition, reflecting Brian MacKay-Lyons' eco-friendly approach. With the addition of these features, Brian sought to minimize the ecological footprint of their project. Some of the features include:
Strategically positioned glazing and openings for harnessing natural lighting.
Each pavilion's tall end features floor-to-ceiling windows that let in enough natural light to minimize the need for artificial lighting, and the narrow buildings' cross ventilation system does away with the need for air conditioning.
Passive solar heating.
Rainwater harvesting.
Awards and distinctions
2011 North American Wood Design Citation
2011 Canadian Architect Award of Excellence
2011 Nova Scotia Lieutenants Governor's Medal of Excellence
2012 Architectural Record, Record Houses Award
2012 Azure Magazine, AZ People's Choice Design Award
2014 Mies Crown Hall America's Prize, Nominated
2014 Architizer Awards, People's Choice Award
2016 AIA, International Region Honor Award for Open International
2018 Governor General's Medal for Architecture
References
Buildings and structures in Queens County, Nova Scotia
Sustainable architecture
Buildings and structures completed in 2011 | Two Hulls House | [
"Engineering",
"Environmental_science"
] | 618 | [
"Sustainable architecture",
"Environmental social science",
"Architecture"
] |
76,275,170 | https://en.wikipedia.org/wiki/Beat%20Keller | Beat Keller (born 14 September 1958) is a Swiss molecular biologist and professor of plant molecular biology at the University of Zurich. He is known for his research on disease resistance in cereals.
Life
Keller studied biology at the University of Basel from 1978 to 1982. His dissertation dealt with shape-determining proteins of the bacteriophage capsid T4: The role of gene products 67 and 68. In 1985 he began a postdoctoral fellowship at the Biozentrum of the University of Basel. In 1986, he continued his training as a molecular biologist with an EMBO Longterm Fellowship at the Salk Institute for Biological Studies in San Diego, where he worked in the plant biology research group of Christopher John Lamb. In 1989, Keller returned to Switzerland and founded a plant biotechnology group at the Swiss Federal Research Station for Agronomy (today Agroscope). The group, which specialized in cereal genetics, disease resistance and molecular markers, was headed by Keller until 1997. In 1995, he became a lecturer at ETH Zurich and in 1997 accepted an appointment as Professor of Molecular Plant Biology at the University of Zurich.
From 1997 to 2014, he was Director of the Institute of Plant Biology at the University of Zurich and from 2002 to 2006 and from 2016 to 2018 Chairman of the Department of Biology. From 2000 to 2006, Keller was Vice President of the Swiss Academy of Sciences (SCNAT) and is codirector of the research program "Evolution in Action". From 2014 to 2022, he was a member of the Research Council of the Swiss National Science Foundation. He is a member of the National Academy of Agricultural Sciences, India, and was admitted as a member of the section Agricultural and Nutritional Sciences of the
German National Academy of Sciences Leopoldina on 23 June 2015.
Scientific contribution
Beat Keller's research focuses on the molecular basis of disease resistance in the cereals wheat, maize, barley and rye. This involves characterizing genes that are responsible for the formation of specific immune receptors. This included the isolation of the first resistance genes against fungal diseases in wheat and against leaf spot disease in maize. In 2021, novel resistance genes were identified in wheat against powdery mildew and wheat leaf rust. In addition, an important quantitative resistance gene, Lr34, was isolated, which is used intensively in wheat cultivation worldwide and has a novel resistance mechanism. Modified resistance genes were tested in field trials (www.protectedsite.ch) in transgenic wheat and barley plants.
In complementary research directions, the molecular mechanisms of the evolution of the powdery mildew pathogen in its adaptation to new host species were identified and the molecules of the pathogen recognized by immune receptors were characterized. The work on the wheat genome within the framework of the International Wheat Genome Sequencing Consortium led to the production of the first high-quality wheat genome sequence.
Publications
Publication list Google Scholar
See also
Wheat: Disease resistance
External links
Membership at the German National Academy of Sciences Leopoldina
„Sexual reproduction only second choice for powdery mildew“, Max Planck Institute for Plant Breeding Research, July 2013
Welcome to Beat Keller's group, University of Zurich
References
1958 births
Molecular biologists
University of Zurich
Swiss biologists
Living people
Academic staff of ETH Zurich | Beat Keller | [
"Chemistry"
] | 648 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
76,276,064 | https://en.wikipedia.org/wiki/John%20W.%20Dold | John William Dold (also known as Bill Dold) is an emeritus professor in the department of mathematics in the University of Manchester, a specialist in the field of Fluid Mechanics and Combustion. He was the founder of the journal Combustion Theory and Modelling.
Biography and research
John attended school at the Christian Brothers College, Bulawayo in Zimbabwe. He completed his bachelors (1971–1974) at the University of Zimbabwe and his doctoral degree (1976–1979) at the Cranfield University under the supervision of John Frederick Clarke. He obtained a master's degree (1971–1974) in area studies at the University of London.
He then joined the faculty of the mathematics department at the University of Bristol and then joined the faculty of mathematics department at the University of Manchester in 1995. In 1997, he along with Mitchell D. Smooke, founded the journal Combustion Theory and Modelling. He also worked at Greater Manchester Fire and Rescue Service from 2010 to 2013. He served as the vice president of SIAM United Kingdom and Republic of Ireland Section from 1998 to 1999. He also served as the editor for Combustion Theory and Modelling and SIAM Journal on Applied Mathematics.
John Dold has made significant contributions in theoretical combustion science, particularly in areas related to partially premixed combustion, fire, ignition, detonations and also in the field of fluid mechanics and wate waves. Kerr–Dold vortex, an exact solution of Navier–Stokes equations is named after him,
Books
See also
Moshe Matalon
Paul Clavin
John Frederick Clarke
Amable Liñán
Forman A. Williams
Gregory Sivashinsky
John D. Buckmaster
References
External links
Homepage
Fluid dynamicists
Alumni of the University of London
Alumni of Cranfield University
Living people
Academics of the University of Manchester
Zimbabwean mathematicians
Year of birth missing (living people) | John W. Dold | [
"Chemistry"
] | 367 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
76,276,121 | https://en.wikipedia.org/wiki/Model%20collapse | Model collapse is a phenomenon where machine learning models gradually degrade due to errors coming from uncurated training on the outputs of another model, including prior versions of itself. Such outputs are known as synthetic data.
Shumailov et al. coined the term and described two specific stages to the degradation: early model collapse and late model collapse. In early model collapse, the model begins losing information about the tails of the distribution – mostly affecting minority data. Later work highlighted that early model collapse is hard to notice, since overall performance may appear to improve, while the model loses performance on minority data. In late model collapse, the model loses a significant proportion of its performance, confusing concepts and losing most of its variance.
Mechanism
Using synthetic data as training data can lead to issues with the quality and reliability of the trained model. Model collapse occurs for three main reasons – functional approximation errors, sampling errors, and learning errors. Importantly, it happens in even the simplest of models, where not all of the error sources are present. In more complex models the errors often compound, leading to faster collapse.
Disagreement over real-world impact
Some researchers and commentators on model collapse warn that the phenomenon could fundamentally threaten future generative AI development: As AI-generated data is shared on the Internet, it will inevitably end up in future training datasets, which are often crawled from the Internet. If training on "slop" (large quantities of unlabeled synthetic data) inevitably leads to model collapse, this could therefore pose a difficult problem.
However, recently, other researchers have disagreed with this argument, showing that if synthetic data accumulates alongside human-generated data, model collapse is avoided. The researchers argue that data accumulating over time is a more realistic description of reality than deleting all existing data every year, and that the real-world impact of model collapse may not be as catastrophic as feared.
An alternative branch of the literature investigates the use of machine learning detectors and watermarking to identify model generated data and filter it out.
Mathematical models of the phenomenon
1D Gaussian model
In 2024, a first attempt has been made at illustrating collapse for the simplest possible model — a single dimensional normal distribution fit using unbiased estimators of mean and variance, computed on samples from the previous generation.
To make this more precise, we say that original data follows a normal distribution , and we possess samples for . Denoting a general sample as sample at generation , then the next generation model is estimated using the sample mean and variance:
Leading to a conditionally normal next generation model . In theory, this is enough to calculate the full distribution of . However, even after the first generation, the full distribution is no longer normal: It follows a variance-gamma distribution.
To continue the analysis, instead of writing the probability density function at each generation, it is possible to explicitly construct them in terms of independent random variables using Cochran's theorem. To be precise, and are independent, with and , following a Gamma distribution. Denoting with Gaussian random variables distributed according to and with random variables distributed with , it turns out to be possible to write samples at each generation as
and more generally
Note, that these are not joint distributions, as and depend directly on , but when considering on its own the formula above provides all the information about the full distribution.
To analyse the model collapse, we can first calculate variance and mean of samples at generation . This would tell us what kind of distributions we expect to arrive at after generations. It is possible to find its exact value in closed form, but the mean and variance of the square root of gamma distribution are expressed in terms of gamma functions, making the result quite clunky. Following, it is possible to expand all results to second order in each of , assuming each sample size to be large. It is then possible to show that
And if all sample sizes are constant, this diverges linearly as :
This is the same scaling as for a single dimensional Gaussian random walk. However, divergence of the variance of does not directly provide any information about the corresponding estimates of and , particularly how different they are from the original and . It turns out to be possible to calculate the distance between the true distribution and the approximated distribution at step , using the Wasserstein-2 distance (which is also sometimes referred to as risk):
This directly shows why model collapse occurs in this simple model. Due to errors from re-sampling the approximated distribution, each generation ends up corresponding to a new step in a random walk of model parameters. For a constant sample size at each generation, the average distance from the starting point diverges, and in order for the end distribution approximation to be accurate, or for the distance to be finite, the sampling rate needs to increase superlinearly, i.e. one needs to collect increasingly more samples over time, perhaps quadratically. However, even in that case the expected distance after steps remains non-zero and the only case in which it does in fact end up being zero is when sampling is infinite at each step. Overall, this only shows us how far on average one ends up from the original distribution, but the process can only "terminate", if the estimated variance at a certain generation becomes small enough, effectively turning the distribution into a delta function. This is shown to occur for a general gaussian model in the subsection below. Empirical investigation has confirmed this theoretical analysis.
N-D Gaussian model
Furthermore, in the case of multidimensional model with fully synthetic data, exact collapse can be shown.
Linear regression
In the case of a linear regression model, scaling laws and bounds on learning can be obtained.
Statistical language model
In the case of a linear softmax classifier for next token prediction, exact bounds on learning with even a partially synthetic dataset can be obtained.
Impact on large language models
In the context of large language models, research found that training LLMs on predecessor-generated text — language models are trained on the synthetic data produced by previous models — causes a consistent decrease in the lexical, syntactic, and semantic diversity of the model outputs through successive iterations, notably remarkable for tasks demanding high levels of creativity.
See also
Generation loss
Generative artificial intelligence
Notes
References
Generative artificial intelligence | Model collapse | [
"Engineering"
] | 1,279 | [
"Artificial intelligence engineering",
"Generative artificial intelligence"
] |
76,276,578 | https://en.wikipedia.org/wiki/Chrompodellid | Chrompodellids are a clade of single-celled protists belonging to the Alveolata supergroup. It comprises two different polyphyletic groups of flagellates: the colpodellids, phagotrophic predators, and the chromerids, photosynthetic algae that live as symbionts of corals. These groups were independently discovered and described, but molecular phylogenetic analyses demonstrated that they are intermingled in a clade that is the closest relative to Apicomplexa, and they became collectively known as chrompodellids. Due to the history of their research, they are variously known in biological classification as Chromerida or Colpodellida (ICZN)/Colpodellales (ICN).
Description and life cycle
Chrompodellids are a clade of unicellular protists containing two functionally different groups: the photosynthetic "chromerids" and the predatory phagotrophic "colpodellids". Like other Alveolata, they present tubular mitochondrial cristae and highly flattened cortical alveoli with microtubules underneath. They exhibit a conoid-like structure similar to that of apicomplexans, with an apical complex, a micropore and a rostrum. They live as flagellates with two anisokont (i.e. differently sized) flagella that are heterodynamic (i.e. move in different patterns). Some species exhibit thin mastigonemes in their anterior flagellum, while others bear bulbs. Some species are capable of forming cysts.
Colpodellids
Colpodellids, represented by the genera Colpodella, Alphamonas, Voromonas and Chilovora, are free-living predatory phagotrophic flagellates. They live as biflagellated single cells, 5–20 μm in length, with an open conoid and rhoptries used to hunt. They present genetic sequences of non-photosynthetic plastids, evidence of their phototroph ancestry.
Some species, considered ectoparasites, do not ingest prey cells, but rather fully or partially "suck" their contents, a process known as myzocytosis, common among alveolates. They feed on bacteria and other protozoa, such as bodonids, chrysomonads, bicosoecids, percolomonads and ciliates. After feeding, they internalize their flagella, become cysts and divide into tetrads, similarly to the development of zoospores in Chromera. The cells conjugate after leaving the cyst, which could imply a sexual stage.
Chromerids
Chromerids, represented by the genera Chromera and Vitrella, are photosynthetic protists, and are thus considered algae. They exist in association with corals. For most of their life cycle, they live as round (coccoid) brownish immobile vegetative cells called autospores, surrounded by a thick resistant cell wall. They contain one chloroplast in each cell, with chlorophyll a, violaxanthin, and β-carotene.
The two genera are markedly different from each other, both in phylogeny and life cycles. Chromera autospores are 5–7 μm in diameter. They asexually reproduce through binary division to develop autosporangia, which in turn harbor 2–4 autospores under an additional membrane. They also form zoosporangia, up to 15 μm in diameter, capable of generating 2–10 flagellated zoospores that strongly resemble colpodellids. This dispersal process is similar to the schizogony of apicomplexans. Sexual reproduction has not been observed. Under adverse environmental conditions, they form resistant cysts that remain viable for years. Similarly to apicomplexans, they undergo closed mitosis, without dissolving the nuclear envelope. In addition, Chromera produces high amounts of an exclusive type of isofucoxanthin.
Vitrella autospores, by contrast, start measuring 3 μm and grow up to 40 μm before transforming into sporangia that generate dozens of autospores or zoospores. There are two types of Vitrella zoospores: one is generated by budding from the mother cell and exhibits flagella outside the cytoplasm, the other develops axonemes and flagella within their cytoplasm and are ejected from the mother cell after maturing, though both types lack a pseudo-conoid. Some zoospores fuse, possibly representing a sexual stage in the life cycle. In addition, Vitrella produces vaucheriaxanthin.
Evolution
Chrompodellids are the closest living relatives of the apicomplexan parasites, which evolved from a photosynthetic myzozoan ancestor, making chromerids the last remaining photosynthetic members of an otherwise parasitic clade within Alveolata. The apicomplexans, chrompodellids, perkinsids and dinoflagellates constitute the clade Myzozoa, characterized by the apical complex and plastids derived from an event of secondary endosymbiosis with a red alga. The photosynthetic ability of these plastids was eventually lost in apicomplexans, colpodellids, perkinsids and other groups that transitioned into a predatory or parasitic lifestyle. The following cladogram summarizes alveolate relationships and the internal relationships among most genera within the chrompodellid clade (chromerids marked with asterisks):
Systematics
Taxonomic history
In 1993, protozoologist Thomas Cavalier-Smith described the order Colpodellida (under the ICZN, later regularized as Colpodellales in accordance to the ICN) to contain what he considered one of the "most primitive flagellate apicomplexans", the genus Colpodella. This order was introduced in the class Apicomonadea along with the Perkinsida. Cavalier-Smith treats this class as a member of the phylum Apicomplexa, while "true" apicomplexans are united under the name Sporozoa. Although the inclusion of colpodellids within apicomplexans was not supported by other authors, phylogenetic studies demonstrated that they were sister clades.
The first chromerid alga, Chromera velia, was discovered and isolated from Australian corals in 2001. It was described in 2008 as the first member of a new phylum Chromerida, followed by Vitrella brassicaformis in 2012. They showed morphological resemblance to colpodellids and other myzozoans. In the following years, phylogenetic studies reported the evolutionary proximity between colpodellids and chromerid algae. This was supported by the discovery of retained vestigial plastids in some colpodellid species. In 2015 there was strong support for a clade containing the two groups, phylogenetically mixed with each other, which rendered both as polyphyletic. The clade was given the provisional name "chrompodellids", later referred to as Chrompodellida by posterior studies.
Between 2004 and 2017, Cavalier-Smith retained the classification scheme of Apicomonadea, from which he excluded Perkinsida, leaving only colpodellids and chromerids across multiple orders. In addition, several genera of flagellates were added on the basis of morphological data: Algovora, Microvorax and Dinomonas. Due to lacking molecular data, these genera have been excluded from later classifications. Two genera, Chilovora and Alphamonas, were eventually rejected in his classification, but later revisions by other authors maintain them as independent genera supported by molecular data.
The treatment of chrompodellids as a subgroup of Apicomplexa, under the name of Apicomonadea, was rejected by the International Society of Protistologists. In a 2019 revision of eukaryotic classification, protistologists emended the previous name Colpodellida to contain all chrompodellids, and treated it as a direct subgroup of Alveolata, independent from Apicomplexa. Later, phycologists advocated for this treatment as a separate phylum, and regularized it under the name of Chromerida or Chromeridophyta, composed of a single class Chromeridophyceae and a single order Colpodellales, in accordance to the nomenclatural rules of the ICN. However, other authors consider them a subgroup of the phylum Myzozoa, together with apicomplexans, perkinsozoans and dinoflagellates.
Classification
As of 2023, chrompodellids are divided into four families and seven genera:
Family Alphamonaceae
Alphamonas
Family Chromeraceae
Chromera
Family Colpodellaceae
Chilovora
Colpodella
Voromonas
Family Vitrellaceae
Vitrella
Incertae sedis: Piridium (sister group to Vitrella but not formalized as a member of Vitrellaceae)
References
Alveolata
Microbiology
Microorganisms
Protista
Algae | Chrompodellid | [
"Chemistry",
"Biology"
] | 1,928 | [
"Algae",
"Protists",
"Microbiology",
"Microscopy",
"Eukaryotes",
"Microorganisms"
] |
76,276,799 | https://en.wikipedia.org/wiki/Foliosum | The botanical Latin word foliosum is a specific epithet used in the name of several species. The word "foliosum" comes from the Latin "foliosus" which refers to a leaf.
Flowering plants
The following list consists of flowering plant species names given by the Royal Botanic Garden Kew's Plants of the World Online.
Other plants
The following list consists of non-flowering plant species names given by Flora of North America and the Global Biodiversity Information Facility.
Marine animals
The following list consists of marine animal names given by the World Register of Marine Species.
See also
Foliosa
Foliosus
Foliatus
Foliaceus
Notes
References
Set index articles on organisms | Foliosum | [
"Biology"
] | 137 | [
"Set index articles on organisms"
] |
56,260,940 | https://en.wikipedia.org/wiki/Fluorenylmethyloxycarbonyl%20protecting%20group | The fluorenylmethoxycarbonyl protecting group (Fmoc) is a base-labile amine protecting group used in organic synthesis, particularly in peptide synthesis. It is popular for its stability toward acids and hydrolysis and its selective removal by weak bases, such as piperidine, without affecting most other protecting groups or sensitive functional groups. Fmoc protection is especially advantageous in solid-phase peptide synthesis (SPPS), where its compatibility with other reagents and ease of removal streamline synthesis workflows. Upon deprotection, Fmoc yields a byproduct (Dibenzofulvene) that can be monitored by UV spectroscopy, allowing for efficient reaction tracking.
Protection & Formation
Fmoc-carbamate is frequently used as a protecting group for primary and secondary amines, where the Fmoc group can be introduced by reacting the amine with fluorenylmethyloxycarbonyl chloride (Fmoc-Cl), e.g.:
The other common method for introducing the Fmoc group is through 9-fluorenylmethylsuccinimidyl carbonate (Fmoc-OSu), which may itself be obtained by the reaction of Fmoc-Cl with the dicyclohexylammonium salt of N-hydroxysuccinimide.
Reacting with 9-fluorenylmethyloxycarbonyl azide (itself made by reacting Fmoc-Cl with sodium azide) in sodium bicarbonate and aqueous dioxane is also a method to install Fmoc group.
Because the fluorenyl group is highly fluorescent, certain UV-inactive compounds may be reacted to give the Fmoc derivatives, suitable for analysis by reversed phase HPLC. Analytical uses of Fmoc-Cl that do not use chromatography may be limited by the requirement that excess Fmoc-Cl be removed before an analysis of fluorescence.
Cleavage & Deprotection
The Fmoc group is rapidly removed by base. Piperidine is usually preferred for Fmoc group removal as it forms a stable adduct with the dibenzofulvene byproduct, preventing it from reacting with the substrate.
Role in Peptide Synthesis
The use of Fmoc as a temporary protecting group for amine at the N-terminus in solid phase synthesis is very widespread for Fmoc/tBu approach, because its removal with piperidine does not disturb the acid-labile linker between the peptide and the resin. A typical SPPS Fmoc deprotection is performed with a solution of 20% piperidine in N,N-dimethylformamide (DMF).
Common deprotection cocktails for Fmoc during SPPS
20% piperidine in DMF (Fmoc group has an approximate half life of 6 seconds in this solution)
5% piperazine, 1% DBU and 1% formic acid in DMF. This method avoids the use of strictly controlled piperidine. No side product was observed for a peptide with 9 residues synthesized with this method.
References
External links
Biochemistry methods
Protecting groups | Fluorenylmethyloxycarbonyl protecting group | [
"Chemistry",
"Biology"
] | 648 | [
"Biochemistry methods",
"Functional groups",
"Reagents for organic chemistry",
"Biochemistry",
"Protecting groups"
] |
56,261,151 | https://en.wikipedia.org/wiki/CO%20stripping | In electrochemistry, CO stripping is a special process of voltammetry where a monolayer of carbon monoxide already adsorbed on the surface of an electrocatalyst is electrochemically oxidized and thus removed from the surface. A well-known process of this type is CO stripping on Pt/C electrocatalysts in which the electrooxidation peak occurs somewhere between 0.5 to 0.9 V depending on the characteristics and structural properties of the specimen.
Principle
Some metals, such as platinum, readily adsorb carbon monoxide, which is usually undesirable as it results in catalyst poisoning.
However, the strong affinity of CO to such catalysts also presents an opportunity: since carbon monoxide is a small molecule with a strong affinity to the catalyst, a large enough amount of CO will adsorb to the entire available surface area of the catalyst. That, in turn, means that by evaluating the amount of CO adsorbed, the catalyst's available surface area can be indirectly measured.
That surface area - also known as "real surface area" or "electrochemically active surface area" - can be measured by electrochemically oxidizing the adsorbed carbon monoxide, as the charge expended in oxidizing CO is directly proportional to the amount of CO adsorbed on the surface and therefore, the surface area of the catalyst.
Usage
CO stripping is one of the methods used to determine the electrochemically active surface area of electrodes and catalysts that irreversibly adsorb carbon monoxide, most notably ones containing platinum and other transition metals.
References
Separation processes
Electroanalytical methods
Electrochemistry | CO stripping | [
"Chemistry"
] | 344 | [
"Electroanalytical chemistry",
"Separation processes",
"Electrochemistry",
"nan",
"Electroanalytical methods"
] |
56,263,767 | https://en.wikipedia.org/wiki/Sleep%20deprivation%20in%20higher%20education | Sleep deprivation – the condition of not having enough sleep – is a common health issue for students in higher education. This issue has several underlying and negative consequences, but there are a few helpful improvements that students can make to reduce its frequency and severity.
On average, university students get 6 to 6.9 hours of sleep every night. Based on the Treatment for Sleep Disorders, the recommended amount of sleep needed for college students is around 8 hours. According to Stanford University's Department for the Diagnosis, 68% of college students aren't getting the sleep they need. The main causes of sleep deprivation include poor sleep hygiene, biology, use of technology, and use of drugs. The effects can damage the student's GPA, relationships, focus and memory, and emotional and mental health. Students may face depression, anxiety, and difficulty maintaining their relationships in a healthy manner. There are many possible solutions to combat sleep deprivation including improving bedroom environment, reducing exposure to blue light, and taking naps during the day.
Background
The term sleep deprivation can be defined as having a lack of sleep that does not support daytime awareness. In most literature, sleep deprivation is further categorized into either acute sleep deprivation or chronic partial sleep deprivation. Chronic partial sleep deprivation is a form of sleep deprivation caused when one obtains some but inadequate sleep. Acute sleep deprivation is more widely known as the scenario in which one is awake for 24 hours or longer.
From student reports, 70.65% of students are sleep deprived and 50% of college students exhibit daytime sleepiness. Additionally, only 4% of students obtain 7 hours of sleep or more. The average was 5.7 hours of sleep and students on average pull 2.7 "all-nighters" per month. Note that "all-nighters" is the term used when one does not sleep throughout the entire night.
Causes
Sleep hygiene
Inadequate sleep hygiene is one reason why college students specifically experience sleep deprivation. Sleep hygiene is defined as habits or practices that allow for healthy amounts of sleep on a daily basis. Good sleep hygiene habits include keeping a consistent sleep schedule, having a quiet sleep environment, avoiding the consumption of caffeine after lunch, and minimizing alcohol consumption before bed. A study published in 2018 on the Journal of Clinical Sleep Medicine found that over the course of 8 weeks, college students that partook in sleep hygiene education had improved sleep quality. Being consistent in these habits can lead to increased daytime energy level, improved mood, enhanced immune system function, and decreased stress. With college students, consistency is often hard; this idea is very prevalently shown in regard to sleep hygiene. Late night studying, meetings, roommates, socializing/social events, etc. all can cause a student's sleep schedule and environment to be inconsistent on a day-to-day basis and allow an opportunity for disruptions such as alcohol before bed.
Technology
Using technology before falling asleep can affect a student's sleep pattern. The blue light that is emitted from the screens of cell phones, computers, and other devices stops the production of melatonin, a hormone that controls the sleep-wake cycle of the circadian rhythm. This reduction of the amount of melatonin produced makes it harder to fall and stay asleep. The National Sleep Foundation conducted a poll in 2011 and reported that approximately 90% of Americans used technology in the hour before bed. The poll noted that young adults and teenagers, such as college students, were more likely to use cell phones, computers, and video game consoles than other adults. Furthermore, 22% of participants reported going to sleep with cell phone ringers on in their bedroom and 10% reported awakenings in at least a few nights per week due to their cell phones' ringers. Among those with the cell phone ringers on, being awakened by their cell phone was directly correlated to difficulty sustaining sleep.
According to Elizabeth B. Dowdell and Brianne Q. Clayton, sleep-deprived college students performed significantly worse on cognitive skills than peers who had adequate. Furthermore, the sleep-deprived students were not aware of the extent to which sleep deprivation negatively affects their ability to complete cognitive tasks. Research has shown that individuals with excessive technology use in the bedroom have later bedtimes and tend to sleep later in the morning. The reliance on technology in the bedroom, which should be associated only with sleep, creates difficulty separating waking and sleeping activities. When measuring the amount of sleep during the week compared to the weekend, students with four or more technological devices in their bedroom had significantly less sleep compared to those with three or fewer devices. Since many students do not utilize the do not disturb mode or silence their phones at night, each notification and alert from their phones disrupts their sleep in terms of quality and duration.
Circadian rhythm
Several recent studies have shown that adolescents undergo a change in their circadian rhythm which shifts sleep times later into the night. This change seems to occur during puberty, extending well into adulthood. The delay in sleep cycles clashes with the structured early morning schedules of students due to early classes or work; thus, the total amount of sleep time is greatly reduced. This imbalance in circadian rhythm can lead to extremely harmful affects on students' learning and memory processes as well. This is largely in part because circadian rhythm has a "master clock" that is located in the same part of the brain that is responsible for forming memories, learning, and emotions. There has been a push in many educational systems for a later start time to help increase the available time for sleep in adolescents due to these biological changes. Additionally, many college students have jobs that increase the length of time they spend awake. Some may have class most of the day then work most of the night, or vice versa. Either one of these would be enough to change their already-established circadian rhythm, resulting in feeling sleepy when they should be awake and wide-awake when they should be asleep.
Scheduling
Many college students have variable day-to-day class schedules that change one's daily routine. Additionally, many college campuses offer late night social activities that can begin as late as 10 pm. These activities are crucial for college students because they allow socialization and bonding with one another, which may boost one's mood. Similarly, many organizations such as fraternities and sororities on college campuses hold events and fundraisers that often occur late and/or throughout the night, and are often mandatory obligations. Having to work or attend an event in the middle of the night can cause someone's sleep schedule to be disrupted for the entire day and possibly into the next day. Some students may have to go to class most of the day then work most of the night, or vice versa. Even beyond that, students have to find a way to balance scheduling time for normal friends, family, and any other relationships. On top of this, many students live with roommates and/or near neighbors that might not adhere to the same sleep schedule, thus disrupting theirs. All of this doesn't even include extra activities like appointments, meetings, etc. that take up even more of the day.
Stimulants
Stimulants increase the time it takes to fall asleep as well as suppress REM (rapid eye movement) sleep states. Those who use stimulants report worse sleep qualities, like increased sleep onset latency and reduced sleep efficiency due to stimulants' ability to block dopamine reuptake, stimulate dopamine release, or both. Through a study conducted within 119 colleges and universities across the US, 6.9% of stimulants used present a lifetime prevalence for students, potentially meaning a lifetime prevalence of sleep disruption. Men are more likely to use stimulants, caffeine, and energy drinks, though women are more likely to use stimulants solely for the purpose of energy. Non-prescribed use of stimulants can increase the use of alcohol, cocaine, and marijuana.
Caffeine
A study from the University of Kentucky showed that more than 78% of college freshmen consume above the recommended amount of caffeine each day. One-tenth of the US population already suffers from insomnia, and in turn caffeine is often used as a countermeasure for the side effects associated with this lack of sleep. However, consuming large amounts of caffeine (versus consuming light or no caffeine) is associated with higher insomnia symptoms and daytime sleepiness. In a study from the Henry Ford Hospital's Sleep and Research Center and Wayne State College of Medicine, they discovered that caffeine consumed within six hours of bedtime can significantly disrupt sleep. Participants in this study who consumed caffeine right before bedtime, three hours before bedtime, and six hours before bedtime all experienced a shorter night's sleep, lower sleep quality, and spent more time awake at night.
College students often drink coffee as their source of caffeine. 2-4 cups of coffee at night can increase the time it takes to fall asleep to nearly twice the normal amount. The average time takes to fall asleep is roughly 6.3 minutes, but with caffeine this time is increased to 12.1 minutes. Energy drinks are also a widely used form of caffeine due to their wide availability and evolving promises to meet all kinds of needs, such as improved academic or mental performance. The caffeine in energy drinks are what is primarily responsible for the increase of energy. Each drink varies widely between 45–500 mg of caffeine. 34% of 18-24-year-olds consume energy drinks regularly. 67% of users consume energy drinks to compensate for the lack of sleep. Additionally, energy drinks are associated with the higher risk of alcohol, drug, and stimulant usage, as well as increased insomnia symptoms, specifically in people with higher levels of baseline anxiety.
Adderall
Adderall is a drug that affects the central nervous system and is prescribed to individuals with attention deficit hyperactivity disorder (ADHD) and/or narcolepsy. This drug is commonly misused by college students as a "study drug," although research suggests that stimulants are more efficient at correcting shortfalls than enhancing performance. Adderall is a highly abused substance among students in higher education because it prevents the reuptake of dopamine, allowing college students to stay up all day or night and remain alert. The effects of recreational use are exhaustion and an accumulation of "sleep debt." When you sleep fewer hours than your body needs, you acquire this "sleep debt," which adds up over time and negatively impacts your health. The effects of this debt can be loss of focus, difficulty processing and storing new information, and eventually as debt accumulates, hypertension, diabetes mellitus, coronary heart disease, obesity, and cardiovascular diseases. Furthermore, frequent use of adderall during the day and night can lead to extended sleep deprivation and insomnia.
Alcohol
College students who consume moderate to severe amounts of alcohol are increasingly likely to face lower quality of sleep. However, 11.6% of students use alcohol as a sleep aid. A study published in Behavioral Sleep Medicine showed that significant alcohol use can lead to "lower sleep duration, greater sleep schedule irregularity, bedtime delay, weekend oversleeping, and sleep-related impairment." Furthermore, increasing alcohol consumption may lead to the student falling asleep faster, but facing significant sleep disturbance. Alcohol use decreases REM sleep, so a student who consumes alcohol may sleep for the normal 7–8 hours, but the sleep quality will be lower than an individual who was sober. Additionally, consumption of alcohol can increase the chances of developing obstructive sleep apnea. Roughly 4 out 5 college students drink alcohol. 40% of men and women reported binge drinking 4-5 drinks in a row within the past 2 weeks. Even binge drinking once can actually alter the gene that regulates sleep, resulting in sleep disturbance.
Effects
Physical
Sleep cycles
Irregular sleep schedules can cause negative impacts on learning, memory, and performance. The dual process theory determines that certain types of memory depend on specific sleep states, like REM and NREM (Non-Rem) states. REM sleep deprivation can reduce sleep-induced improvement such as visual perception, thus influencing how one learns. REM sleep occurs every 90–120 minutes, which is roughly 4-5 times a night. REM periods of sleep increase in time with every cycle. Thus, when college students sleep less, they do not attain the last 1-2 REM cycles and in turn that affects their procedural memory.
Attention and memory
Even if a student is staying awake in class, their ability to truly pay attention is severely diminished. 23.2% of students who do not get enough sleep every night report that they have trouble being able to concentrate on things. Scientists have found that sleep deprivation leads to lower alertness and concentration, resulting in becoming confused more easily. Because of this, the ability to perform tasks requiring complex thought or logical reasoning is diminished. Not being able to concentrate or think logically in class may cause the student to struggle on learning the material, which can in turn lead to increased sleep deprivation from spending more time on homework.
Lack of sleep also affects the formation of memories. Studies show REM sleep is involved in creating memories related to complex information and "students not getting enough sleep will have trouble committing their classes material to memory and learn slower". Forgetfulness is another symptom of sleep deprivation which can be immensely harmful, especially during an exam when memory is crucial. Without adequate sleep, the neurons "can no longer function to coordinate information properly, and students lose the ability to access previously learned information." A study of graduate pharmacy students showed 81.7% of students failed to get 7 hours of sleep on the night before an examination.
Drowsiness
Sleep deprivation causes drowsiness, which can affect students in higher education. Drowsiness can affect students in their classes and poses a risk for those who commute by car to their college campuses. Many students commute by car to their classes from their homes; at the Ohio State University, close to 30% of students commute. Individuals with less than 6 hours of sleep are the most likely to fall asleep at the wheel and with the average university students getting that amount of sleep, the dangers are a real factor for students. Once a student makes it to class, sleep deprivation will affect their ability to stay awake throughout the class. Over 50% of students have fallen asleep in class.
Eating
Less sleep can lead to weight gain and obesity due to decreases in the body's energy expenditure and ability to stop eating once full. When sleeping, leptin levels rise, telling the brain that our body's energy reserves are adequate and we do not need to eat more (i.e suppresses appetite). Without sleep, this level cannot rise, allowing ghrelin to rise instead and rather appetite is increased. Combining this with the already inadequate diets of college students due to time and monetary constraints can combine to result in weight gain in college students. Weight gain in first year college students is a well known phenomenon called the "Freshman 15" in the US or the "Fresher Five" in Australia or New Zealand.
Emotional
Mental health
Insufficient sleep affects students mood by increasing irritability and negatively affecting their emotions. Research shows that sleep deprivation increases amygdala activity which is linked to negative emotions like anger and rage. This can make coping with even minor stressors more difficult and negatively impact our ability to accurately perceive the world. Anxiety is another symptom of sleep loss experienced by students. Lack of sleep amplifies anxiety in people who already experience increased levels of worry. A survey of college students in 2018 showed 63% of students felt "overwhelming anxiety." Depression has also been linked to sleeplessness. In a study of 1,000 young adults those with sleep issues were four times more likely to develop depression. These symptoms are two-directional. Anxiety and depression have been shown to cause sleeplessness, meaning these symptoms can be compound.
Relationships
The effects of sleeplessness also affect relationships among college students. An Ohio State University study showed that couples that obtained less than 7 hours of sleep interacted in a more hostile way. They also are less successful at resolving conflicts when they do come up. This is an effect from the irritability and impaired decision-making exhibited by students with sleep deprivation. Sleep deprivation also has been shown to reduce feelings of gratitude, which is an integral part of a healthy relationship. Similarly, it can also increase feelings of loneliness and rejection, even if it is not the reality of the relationship.
Mood
Sleep deprivation has been found to affect mood as well. This effect is most pronounced in those that are consistently partially sleep deprived, which is the case for many college students. A meta-analysis of several studies regarding sleep deprivation suggests that the effects of partial sleep deprivation are underestimated. Sleep problems and/or sleep deprivation have been shown to decrease functional emotional regulation and impair emotion generation. It can also decrease our levels of empathy and ability to react, making us more prejudiced when tired.
Academic
GPA
Inadequate sleep has been shown to affect student's GPA by up to a .02 drop for every night of the week a student sleeps poorly. Students who obtained 9 hours or more of sleep received a GPA of 3.24. Meanwhile those who had 6 hours or more of sleep received a 2.74 GPA. Among first-year university students, their GPA decreases by 0.115-0.132 for every hour that their sleep schedule is shortened. The effects of poor sleep are similar to that of binge drinking or abusive relationships on students' GPA along with their likeliness to drop one or more classes. The previously mentioned symptoms of inadequate sleep contribute to the drop in GPA. Consequences span from lack of focus to decreased motivation which leads to less hours of studying.
Students with sleep disorders are more likely to not perform well academically. Students with a GPA of 2.0 or lower were at a higher risk for sleep disorders. 30% of those who received positive results for obstructive sleep apnea were at risk for academic failure. Obstructive sleep apnea has shown to influence cognitive function in both children and adults. Other sleep disorders also present a higher risk for academic failure: 22% of those with insomnia, 21% with restless leg syndrome/periodic limb movement disorder, 26% with circadian rhythm sleep disorder, and 21% with hypersomnia.
Social withdrawal
Sleep deprivation may lead to social withdrawal due to increased feelings of loneliness and social isolation. The less sleep we get, the less we want to socially interact. However, social interaction is an important part of the lives of students in higher education to remain emotionally stable. Intrapersonal distress and self-reported loneliness have been linked to worse sleep quality. Over 64% of students in a 2017 study surveying 48,000 college students stated that they had felt lonely in the past year. Loss of sleep leads to a neural behavioral phenotype of social withdrawal and loneliness that can be easily perceived by others, in turn making one more lonely. The lack of social interaction has also been linked to higher levels of anxiety and depression, which can negatively affect students. Social withdrawal also negatively affects college students’ social lives because when they feel drowsy they are less likely to seek out new experiences, which is an integral part of a student's time in higher education.
Possible improvements
Establishing circadian rhythm
Circadian rhythm is our bodies’ system that internally monitors and regulates sleep and waking hours in a 24-hour period. Sleeping a consistent number of hours will reduce feelings of drowsiness throughout the day, especially due to the large amount of sleep necessary for students. Going to sleep at a consistent time and having a consistent routine can also be just as important as sleeping the same number of hours each night. Avoiding excess daytime napping, especially in the afternoon, is also a big part of a schedule that can help maintain regular circadian rhythm. Students with consistent sleeping schedules had better grades on average than students with irregular sleep schedules according to a study conducted by Brigham and Women's Hospital. Since circadian rhythm is a full 24-hour rhythm, it can also be beneficial to keep a regular meal and exercise schedule throughout the day. These schedule changes may impact circadian rhythm, and will take time for your body to adjust to.
Most modern technology with screens emit blue light, which has the ability to impact and shift circadian rhythms by tricking the body's response to normal changes in light. As stated previously, exposure to blue light has the ability to suppress melatonin, a hormone that helps prepare our body for sleep. Exposure in the early evening causes a delay to release that melatonin and therefore impacts our bodies' circadian rhythm by shifting it back. However, there are melatonin receptor agonists and melatonin supplements available that can be used to help establish a routine and get quality sleep. Additionally, caffeine, alcohol, nicotine, and medication with certain non-drowsy ingredients should be limited, especially near bedtime.
Naps
Napping can be an emergency measure used to help improve performance in the short term as well as supplement missing hours of sleep. Naps can have several purposes, most commonly to either prevent sleepiness or recover from sleepiness when working on a task. Naps should be 60 to 90 minutes for the greatest benefits but any longer may result in affecting a person's circadian rhythm. After napping, a person can wake with sleep inertia, where a person feels groggy or disoriented after waking.
Naps have positive short term effects, especially in improving performance and attention. A study conducted at the University of California, Riverside showed that participants performed similarly on an exam after a 90-minute nap compared to a full eight hours of sleep. Similarly, NASA conducted a study involving its pilots, where even a minimal 30 to 40-minute nap improved pilot's "performance by 34% and their alertness by 54%". In another study done by Lau, Alger and Fishbein showed that students who took a nap after studying were more likely to retain and recall what was learned. Both longer and short naps aided in memory retention of material.
Improving bedroom environment
Students can improve their bedroom environments to enhance how fast they fall asleep and better their sleep quality. Studies have shown that outside noise from traffic, students in dorms near them, or warmer temperatures within the bedroom negatively affect sleep. Another negative factor is the presence of outside light, which tricks our brain into thinking it is nearing daytime. It is possible for students to control these factors by changing the thermostat, blocking out sound, and darkening the bedroom. Harvard Medical School recommends keeping the bedroom between 60 and , using a white noise maker or earplugs, and using heavy "black-out" curtains or an eye mask to create the ideal environment.
References
Students, college
Sleep deprivation | Sleep deprivation in higher education | [
"Biology"
] | 4,703 | [
"Behavior",
"Sleep",
"Sleeplessness and sleep deprivation"
] |
56,263,791 | https://en.wikipedia.org/wiki/Trevor%20McDougall | Trevor John McDougall is an Australian physical oceanographer specialising in ocean mixing and the thermodynamics of seawater. He is Emeritus Scientia Professor of Ocean Physics in the School of Mathematics and Statistics at the University of New South Wales, Sydney, Australia, and is Past President of the International Association for the Physical Sciences of the Oceans (IAPSO) of the International Union of Geodesy and Geophysics.
Education
After attending Unley High School in Adelaide, South Australia, McDougall went to St Mark's College (University of Adelaide) and graduated from the University of Adelaide in Mechanical Engineering in 1973. He obtained a Doctor of Philosophy in 1978 from the University of Cambridge and a Graduate Diploma in Economics from the Australian National University in 1982.
Research and career
McDougall undertook his PhD studies in the Department of Applied Mathematics and Theoretical Physics and St John's College, Cambridge of the University of Cambridge where he was supervised by Professors Stewart Turner and Paul Linden. In 1978 he returned to Australia on a Queen's Fellowship in Marine Science at the Research School of Earth Sciences, Australian National University (ANU). After five years at ANU he was appointed to CSIRO in Hobart as a physical oceanographer. Since 2012 he has been Scientia Professor of Ocean Physics in the School of Mathematics and Statistics at the University of New South Wales, Sydney.
McDougall's research in physical oceanography has provided insight to how seawater mixes under different conditions, which is important for understanding climate change. The ocean and the atmosphere play roughly equal roles in transporting heat from the equatorial region to the poles, and McDougall's research is concerned with how the ocean reduces the equator-to-pole temperature differences, thus making Earth habitable.
McDougall is known for developing, together with David Jackett, an algorithm for defining neutral density surfaces. These are the surfaces along which swirling ocean eddies — that are 10–500 kilometres wide and persist for many months — mix. The rate of turbulent mixing in the ocean is a factor of ten million times stronger along "density" surfaces than in the direction across these surfaces. The accurate modelling of the ocean’s role in climate relies on being able to accurately define and evaluate these surfaces. McDougall has also made significant contributions to incorporating the concepts of mixing and heat into ocean models.
He was president of the International Association for the Physical Sciences of the Oceans (IAPSO) of the International Union of Geodesy and Geophysics from 2019-2023 and is past president for 2023-2027. He chaired the working group of SCOR and IAPSO that developed the international standard definitions of the thermodynamic properties of seawater, humid air, and ice (TEOS-10, Thermodynamic Equation of Seawater - 2010), which were adopted by the Intergovernmental Oceanographic Commission in 2009.
Awards and honours
McDougall was elected a Fellow of the Royal Society in 2012. He is also a fellow of the Australian Academy of Science (1997), the CSIRO (2007), the Australian Meteorological and Oceanographic Society (2004), the Institute of Physics (UK) (2012), the Royal Society of New South Wales (2015), the American Geophysical Union (2018), and the International Union of Geodesy and Geophysics (2023). His other awards include:
Alfred Wegener Medal, 2025, awarded by the European Geosciences Union to honour a scientist who has achieved exceptional international standing in atmospheric, hydrological or ocean sciences
2023 NSW Scientist of the Year, awarded by the Premier of New South Wales, Australia.
Prime Minister's Prize for Science, 2022, For his discovery of four new ocean mixing processes and his work to define the thermodynamic properties of seawater
Prize of Excellence, Werner Petersen Foundation, Germany, 2018.
Companion of the Order of Australia in 2018 for eminent service to science, and to education, particularly in the area of ocean thermodynamics, as an academic, and researcher, to furthering the understanding of climate science, and as a mentor of young scientists.
New South Wales Premier's Prize for Excellence in Mathematics, Earth Sciences, Chemistry and Physics, 2017.
John Conrad Jaeger Medal 2015, awarded by the Australian Academy of Science.
Henry Houghton chair for visiting senior earth scientists, Massachusetts Institute of Technology, 2015
Australian Laureate Fellowship, 2015, awarded by the Australian Research Council
Royal Society of Tasmania Medal 2013, awarded by the Royal Society of Tasmania.
Prince Albert I Medal, 2011, awarded by the International Association for the Physical Sciences of the Oceans (IAPSO) of the IUGG for outstanding contributions to the advancement of the physical and/or chemical sciences of the ocean.
Anton Bruun Medal, awarded by the Intergovernmental Oceanographic Commission, 2009.
A.G. Huntsman Award for Excellence in the Marine Sciences, presented by the Royal Society of Canada, 2005.
Centenary Medal, 2001. For service to Australian society and science in marine science.
M. R. Banks Medal, awarded by the Royal Society of Tasmania, 1998.<ref name = "Banks"
Humboldt Prize, given by the Alexander von Humboldt Foundation, Germany, 1997.
David Rivett Medal, awarded to a CSIRO Scientist who is less than 40 years old, 1992.
Frederick White Prize, awarded by the Australian Academy of Science, 1988.
J. T. Knight Prize, 1976, awarded by the University of Cambridge.
South Australian Engineering Design Award, with Dr Garry L. Brown, awarded by Engineers Australia, 1975.
References
External links
Trevor McDougall's UNSW webpage
Australian oceanographers
Australian fellows of the Royal Society
Fellows of the Australian Academy of Science
Fellows of the Royal Society
Fellows of the Royal Society of New South Wales
Fellows of the Institute of Physics
Humboldt Research Award recipients
Academic staff of the University of New South Wales
Fluid dynamicists
Physical oceanographers
1952 births
People from Hobart
Living people
Scientists from Adelaide
Academics from Sydney
Australian National University alumni
University of Adelaide alumni
Alumni of the University of Cambridge
Alumni of St John's College, Cambridge
CSIRO people
Companions of the Order of Australia
Fellows of the American Geophysical Union
People educated at Unley High School | Trevor McDougall | [
"Chemistry"
] | 1,277 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
56,263,862 | https://en.wikipedia.org/wiki/Xi%20Yin | Xi Yin (; born December 1983 ) is a Chinese-American theoretical physicist.
Biography
Yin was accepted to University of Science and Technology of China in 1996, at the age of 12, and completed the (then) 5-year bachelor program in 2001. He gained a PhD at Harvard University in 2006, under the supervision of Andrew Strominger. He was a Junior Fellow at the Harvard Society of Fellows, and a Visiting Member at the Institute for Advanced Study. He joined the Harvard faculty in 2008, and is now a Professor of Physics.
Yin is a recipient of NSF CAREER Award, Sloan Research Fellowship, and New Horizons in Physics Prize. He is a Simons Investigator, and a principal investigator of the Simons Bootstrap Collaboration.
Yin ran the Boston marathon three times, and completed the Leadville Trail 100 Run in 2011.
References
External links
Personal website
1983 births
Living people
21st-century American physicists
21st-century Chinese scientists
Chinese emigrants to the United States
Harvard Graduate School of Arts and Sciences alumni
Harvard Faculty of Arts and Sciences faculty
People from Zhuzhou
Scientists from Hunan
Theoretical physicists
University of Science and Technology of China alumni | Xi Yin | [
"Physics"
] | 231 | [
"Theoretical physics",
"Theoretical physicists"
] |
56,265,185 | https://en.wikipedia.org/wiki/Compensation%20%28cytometry%29 | In cytometry, compensation is a mathematical correction of a signal overlap between the channels of the emission spectra of different fluorochromes.
The photons emitted by fluorochromes have different energies and wavelengths and as flow cytometers use photomultiplier tubes (PMT) in order to convert the photons into electrons, the detector can register the signal from more than one fluorochrome. This creates a signal overlap (spillover) which cannot be removed by the optical system and has to be corrected electronically. The compensation can be done through different flow cytometry software such as Flowjo, Flowlogic, Kaluza etc. The first data compensation was done in 1977 by Michael Loken et al. during a two colour experiment, where mouse splenocytes were stained with fluorescein and rhodamine.
Spillover
When one cell is marked by two or more fluorochromes, the added brightness of one fluorochrome to the other creates significant background noise and affects the strength of the signal. This is called a spillover. The physical overlap between the different emission spectra of fluorochromes can activate different receptors than the ones intended for the given wavelength. The ability to correct this stems from the fact, that the overlap is a linear function, so the measured signal can be averaged and thus corrected. This correction is called compensation.
Compensation is necessary in order to be able to differentiate between populations of cells. This is done by measuring the spectral overlap of the different fluorochromes and using the measured values to create a matrix. The matrix is then inverted and gives the actual compensation values. The flow cytometer then uses these values to correct the overlap in each detector for each colour.
References
External links
https://web.archive.org/web/20041205055418/http://cyto.mednet.ucla.edu/Protocols/flow.htm
http://www.bioinformin.net/cytometry/compensation.php
https://www.bdbiosciences.com/documents/Compensation_Multicolor_TechBulletin.pdf
https://bitesizebio.com/13696/introduction-to-spectral-overlap-and-compensation-flow-cytometry-protocol/
http://www.abcam.com/protocols/fluorescence-compensation-in-flow-cytometry
1977 introductions
1977 in science
Flow cytometry | Compensation (cytometry) | [
"Chemistry",
"Biology"
] | 519 | [
"Flow cytometry"
] |
56,266,699 | https://en.wikipedia.org/wiki/Biological%20Magnetic%20Resonance%20Data%20Bank | The Biological Magnetic Resonance Data Bank (BioMagResBank or BMRB) is an open access repository of nuclear magnetic resonance (NMR) spectroscopic data from peptides, proteins, nucleic acids and other biologically relevant molecules. The database is operated by the University of Wisconsin–Madison and is supported by the National Library of Medicine. The BMRB is part of the Research Collaboratory for Structural Bioinformatics and, since 2006, it is a partner in the Worldwide Protein Data Bank (wwPDB).
The repository accepts NMR spectral data from laboratories around the world and, once the data is validated, it is available online at the BMRB website. The database has also an ftp site, where data can be downloaded in the bulk. The BMRB has two mirror sites, one at the Protein Database Japan (PDBj) at Osaka University and one at the Magnetic Resonance Research Center (CERM) at the University of Florence in Italy. The site at Japan accepts and processes data depositions.
Content
NMR spectral values and derived information
The bulk of the data deposited at the BMRB consists of over 11,900 entries containing 1H, 13C, 15N and 31P assigned chemical shifts and coupling constants of peptides, proteins and nucleic acids. Other derived data like residual dipolar couplings (RDC), relaxation parameters, NOE values, order parameters and hydrogen exchange rates are also available. The database contains also a smaller amount of NMR data from carbohydrates, cofactors and ligands. These data are crossreferenced to 3D structures in the PDB when available. The NMR data are provided in the NMR-STAR file format and a number of format conversion tools are available at the site to convert files from NMR-STAR to other formats.
NMR restraints grid
The NMR restraints grid contains NMR restraints data from over 2500 proteins and nucleic acids collected from PDB depositions. The grid is constructed as four subsets of data:
The original NMR data: This subset contains data as found in depositions from the PDB. The data are in various different file formats and contain information about interatomic distances, dihedral angles and RDC restraints.
Parsed restraints data: Most of the entries in the original data subset have been parsed into the NMR-star file format facilitating its access and use. This subset contains over 9,400 entries.
Converted restraints data (DOCR): Over 500 entries in the parsed subset have been converted to make the atom nomenclature consistent with the corresponding atomic coordinates.
Filtered restraints data (FRED): The data in the DOCR were filtered to remove duplicates, redundancies, inconsistencies and values that do not contribute to structure calculations.
Time-domain data
The BMRB has archived sets of raw time-domain data collected from NMR experiments carried out to calculate restraints and chemical shifts in peptides, proteins and nucleic acids. This collection contains over 200 entries and in many cases the pulse-sequences and the acquisition parameters used are also available.
NMR spectral data from metabolomic compounds
The BMRB hosts a database containing NMR spectral data from hundreds of metabolomic compounds. For most compounds, 1H NMR, 13C NMR, 13C 90o DEPT, 13C 135o DEPT, 1H-1H TOCSY and 1H-13C HSQC are available.
NMR statistics
The BMRB provides a collection of NMR statistical data, including chemical shift distributions for individual atoms in amino acids, ribonucleotides and deoxyribonucleotides. The data are presented as interactive histograms and density plots.
Searches
The BMRB query Grid Interface
The BMRB Query Grid Interface, allows to search the database by molecule type (peptide, protein, DNA, RNA, etc.), by data type (1H chemical shift, 13C chemical shift, coupling constant, etc.), by PDB ID number and by BMRB accession number.
FASTA search
The BMRB site also contains a FASTA search page where the database can be searched for matching nucleotide or peptide sequences.
Search Archive page
From the Search Archive page, it is possible to carry out searches by accession number, author, title, molecule name, and by ID number from other common databases. An Advanced Search option allows to carry out queries using a variety of search parameters like: entry information, citations, molecular assembly, experimental descriptions, NMR parameters, etc. The page contains also links to restraints and metabolomics searches
Restraints search
The NMR restraints grid can be searched by PDB or BMRB number, and also by specific kinds of restraints, like torsion angle, distance, residual dipolar coupling, etc.
Metabolomics search
Through the metabolomics search page. the database can be searched for specific compounds by name, molecular formula, molecular weight, ID number and molecular structure. It can be searched for entries with specific experimental conditions (solvent or field strength). The interface allows also to search for compounds with matching 1D or 2D NMR spectral peak lists.
Data deposition
The BMRB accepts depositions from research groups around the world. Deposition of data containing only NMR spectral data (with no coordinates data) is carried out through the BMRB site using the ADIT-NMR deposition system. The types of data accepted include: NMR spectral parameters, relaxation data, and kinetic and thermodynamic data. Data must be entered in the NMR-STAR format, conversion from other common formats can be carried out using the STARch file converter provided at the site. The site also contains an NMR-STAR template generator which produces formatted tables where NMR data can be entered. NMR time-domain data is uploaded separately via ftp. The BMRB encourages depositors to validate their NMR data before deposition, using one of the validation tools available at the BMRB site, to check for inconsistencies and errors. . Once the data is deposited, it is checked for completeness, consistency and annotated, links to other databases are added and a BMRB accession number is generated. Deposition of data containing NMR and coordinates data is done through the OneDep deposition system of the wwPDB. Once the data is validated and accepted, it receives PDB and BMRB accession numbers.
References
External links
Biological Magnetic Resonance Data Bank website
Worldwide Protein Data Bank website
Biological databases
Public domain databases
Online databases
United States National Library of Medicine
University of Wisconsin–Madison | Biological Magnetic Resonance Data Bank | [
"Biology"
] | 1,370 | [
"Bioinformatics",
"Biological databases"
] |
56,267,432 | https://en.wikipedia.org/wiki/Facebook%20malware | The social media platform and social networking service Facebook has been affected multiple times over its history by intentionally harmful software. Known as malware, these pose particular challenges both to users of the platform as well as to the personnel of the tech-company itself. Fighting the entities that create these is a topic of ongoing malware analysis.
Types of malware and notable incidents
Attacks known as phishing, in which an attacker pretends to be some trustworthy entity in order to solicit private information, have increased exponentially in the 2010s and posed frustrating challenges. For Facebook in particular, tricks involving URLs are common; attackers will maliciously use a similar website such as http://faceb0ok.com/ instead of the correct http://facebook.com/, for example. The 11th International Conference on Detection of Intrusions and Malware, and Vulnerability Assessment (DIMVA), held in July 2014, issued a report condemning this as one of the "common tricks" that mobile computing users are especially vulnerable to.
In terms of applications, Facebook has also been visually copied by phishing attackers, who aim to confuse individuals into thinking that something else is the legitimate Facebook log-in screen.
In 2013, a variant of the "Dorkbot" malware caused alarm after spreading through Facebook's internal chat service. With suspected efforts by cybercriminals to harvest users' passwords affecting individuals from nations such as Germany, India, Portugal, and the United Kingdom. The antivirus organization Bitdefender discovered several thousand malicious links taking place in a twenty-four hour period, and contacted the Facebook administration about the problem. While the infection was contained, its unusual nature sparked interest given that the attackers exploited a flaw in the file-sharing site MediaFire to proliferate phony applications among victims' Facebook friends.
The real computer worm "Koobface", which surfaced in 2008 via messages sent through both Facebook and MySpace, later became subject to inflated, grandiose claims about its effects and spread to the point of being an internet hoax. Later commentary claimed a link between the malware and messages about the Barack Obama administration that never actually existed. David Mikkelson of Snopes.com discussed the matter in a fact-checking article.
On 26 July 2022, researchers at WithSecure discovered a cybercriminal operation that was targeting digital marketing and human resources professionals in an effort to hijack Facebook Business accounts using data-stealing malware.They dubbed the campaign as 'Ducktail' and found evidence to suggest that a Vietnamese threat actor has been developing and distributing the malware with motives appeared to be purely financially driven.
Responses
Individual efforts
In the same vein as actions by Google and Microsoft, the company's administration has been willing to hire "grey hat" hackers, who have acted legally ambiguously in the past, to assist them in various functions. Programmer and social activist George Hotz (also known by the nickname "GeoHot") is an example.
Bug Bounty Program
On July 29, 2011, Facebook announced an effort called the "Bug Bounty Program" in which certain security researchers will be paid a minimum of $500 for reporting security holes on Facebook's website itself. The company's official page for security researchers stated, "If you give us a reasonable time to respond to your report before making any information public and make a good faith effort to avoid privacy violations, destruction of data, and interruption or degradation of our service during your research, we will not bring any lawsuit against you or ask law enforcement to investigate you." The effort attracted notice from publications such as PC Magazine, which noted that individuals must not just be the first to report the security glitch but must also find the problem native to Facebook (rather than an entity merely associated with it such as FarmVille).
Targeting of specific users
In late 2017, Facebook systematically disabled accounts operated by North Koreans in response to that government's use of state-sponsored malware attacks. Microsoft did similar actions. The North Korean government had attracted widespread condemnation in the U.S. and elsewhere for its alleged proliferation of the "WannaCry" malware. Said computer worm affected over 230,000 computers in over 150 countries throughout 2017.
See also
Facebook
Criticism of Facebook
History of Facebook
Issues involving social networking services
Privacy concerns of Facebook
Malware
Browser hijacking
Computer worm
Malware analysis
Mobile malware
Phishing
Security engineering
References
Malware
Malware | Facebook malware | [
"Technology"
] | 904 | [
"Malware",
"Computer security exploits"
] |
56,268,838 | https://en.wikipedia.org/wiki/Mary%20Stella%20Edwards | Mary Stella Edwards (1898–1989) was an English painter, creator of dioramas and poet.
Biography
Mary Stella Edwards was born in Hampstead in 1898, the daughter of Robert Cromwell Edwards an architect. She grew up at 12 Fairfield Avenue, in Staines, Middlesex (now part of Surrey).
Edwards studied art at the Royal College of Art and The Regent Street Polytechnic (now part of the University of Westminster) where she met fellow student Judith Ackland. They became life partners and used a tiny cabin, a former fisherman's store, dating from the mid-19th century, at Bucks Mills as their studio from 1924 until Ackland's death in 1971.
Together with Ackland, Edwards produced dioramas, Ackland made all the models (she invented a method called "Jackanda" to make the models), and Edwards painted their backdrops. The town of Windsor commissioned these dioramas to celebrate the town's history, and they are now at the Windsor & Royal Borough Museum.
Edwards was also a poet and published several volumes throughout her life. She published her first book of poetry Time and Chance in 1926 with the Hogarth Press of Leonard Woolf and Virginia Woolf; Gilbert Murray, philologist, wrote the introduction. The London antique dealer Maggs Bros Ltd has a copy Edwards dedicated to Irish publisher and book collector Alan Clodd, who in 1967 published her works with his Enitharmon Press. Individual poems subsequently appeared in Thomas Moult's The Best Poems of 1930, Art, Prose and Poetry, The Contemporary Review and The Living Age. She also published poetry between 1962 and 1964 in Literary Criticism Teaching edited by Margaret Willy for the Oxford University Press. In 1968 she published A Truce with Time and in 1978 Before and After, with poems in memory of her late partner, Judith Ackland: these poems, according to May Sarton, "express the long-standing affection and solidarity of these two remarkable women and give strength to make unbearable bearable". The volume was published by Enitharmon Press, as did Years Between (1982) and A Further Harvest (1985) with unpublished poems from the period between 1932 and 1984.
Edwards also illustrated books, mostly children's books, painted or drew the frontispiece and designed dust covers. Examples include: The Normal Saturday Fairy Book (1924), The Grand Buffalo (1926), From Track to Highway. A Book of British Roads (1935), Worzel Gummidge Or the Scarecrow of Scatterbrook (1936), Miss Milligan Comes Out (1937), The Muddle-Headed Postman and Other Stories (1937), The Giant Who Made Mistakes (1938) and The Dogs at Abbey Lodge (1937). In addition, she designed - as well as Nina Hamnett, among others - an envelope for the literary journal Coterie, in which the Sitwells, Huxley, Eliot and others published texts; critics thought the cover was too reminiscent of Beardsley.
Edwards' book covers from 1922 to 1938 include illustrations for authors such as Douglas Jerrold, Countess Barcynska, Henryk Sienkiewicz, Anatole France, Rufus King, G.B. Stern, Peggy Wood. After Ackland's death, Edwards closed The Cabin at Bucks Mill and moved to live with her family in Staines. She died in 1989.
Exhibitions
The Boston Marriage of Judith Ackland and Mary Stella Edwards: watercolourists and diorama makers, 20th Annual Lesbian Lives Conference, 15–16 February 2013, Brighton
Legacy
Mary Stella Edwards donated a collection of her own and Ackland's work, dating from 1913 and 1965, to Burton Art Gallery and Museum in Bideford. Other works by Ackland and Edwards are held by the Victoria and Albert Museum, the Museum of London, Amgueddfa Cymru – Museum Wales and Abbot Hall Art Gallery in Kendal, Westmorland.
Bucks Mills Cabin, originally managed by the Ackland-Edwards Charitable Trust, passed to The National Trust in 2004. It is a Grade II listed building under the Planning Act 1990 as amended for its special architectural or historic interest. As agreed with the Ackland-Edwards Charitable Trust, it is an artist–in–residence summer home and occasionally open to public. Listed in 2017, the Cabin was one of Historic England's properties to be given listed status as part of a "queer histories" project.
References
1893 births
1989 deaths
20th-century English women artists
20th-century English LGBTQ people
Alumni of the Royal College of Art
Alumni of the University of Westminster
Artists from London
People from Hampstead
English LGBTQ painters
People from Staines-upon-Thames
People from Torridge District | Mary Stella Edwards | [
"Physics"
] | 965 | [
"Model makers"
] |
56,269,979 | https://en.wikipedia.org/wiki/Vulnerable%20waters | Vulnerable waters refer to geographically isolated wetlands (GIWs) and to ephemeral and intermittent streams. Ephemeral and intermittent streams are seasonally flowing and are located in headwater position. They are the outer and smallest stems of hydrological networks. Isolated wetlands are located outside floodplain and show poor surface connection to tributaries or floodplains. Geographically isolated wetlands encompass saturated depressions that are the result of fluvial, aeolian, glacial and/or coastal geomorphological processes. They may be natural landforms or the result of human interventions. Vulnerable waters represent the major proportion of river networks.
These water bodies show vulnerability to natural and human disturbances because they are poorly hydrologically connected, and they are often located in the gray zone of countries and states' protected water regulatory frameworks. In the US, the protection status of GIWs and ephemeral/intermittent streams in regard to the Clean Water Act is being revised. In the context of European Union (EU) Water Framework Directive (WFD), small headwater streams are neglected, especially in agricultural setting.
These water bodies play an essential hydrological and ecological role at the local-to catchment scale. They control storage of water, sediment in the drainage network, increase sediment filtering and biochemical transformation. Furthermore, vulnerable waters contribute to increases in landscape biodiversity as they serve as refuge to endemic species and conduits for migration. Headwater streams and isolated wetlands shows hydrological and ecological connectivity through intermittent surface processes and groundwater processes.
Definition, types and distribution of vulnerable waters
Ephemeral and intermittent headwater streams
Headwater streams refer to the smallest channels of a river network, where streamflow begins. They are considered first- to third-order streams in the Strahler 's stream classification system. The designation of intermittent and ephemeral stream refers to the continuum of streamflow within a year. An ephemeral stream flows episodically, following a precipitation event, while an intermittent stream flow continuously during a portion of the year. In both cases, the drying of the channel results from the local water table declining below the bed surface. The majority of ephemeral and intermittent streams are in headwater positions, but in lowland settings, small tributaries along the river network can be ephemeral or intermittent.
Geographically-isolated wetlands (GIWs)
Geographically isolated wetlands (GIWs) are wetlands entirely surrounded by uplands. GIWs receive water from adjacent uplands and precipitation. However, no stream of any type supplies water to GIWs. Despite GIWs having poor hydrological connectivity with stream networks, they can exhibit subsurface connectivity or even temporary surface-water outflows toward other wetlands or streams. GIWs lacking complete surface or subsurface hydrological connectivity with any water body will lose water mainly by evapotranspiration or to groundwater that is not connected to a stream network. Despite the absence of hydrological connectivity, they can exhibit biological and chemical connectivity with fluvial systems.
Non-floodplain wetlands
GIWs that are hydrologically connected (by subsurface connection or temporary surface connection) can be considered non-floodplain wetlands. Non-floodplain wetlands are located outside floodplains and display a unidirectional hydrological connectivity with streams, meaning the water is flowing only toward streams located at lower elevations. Hydrological connectivity between non-floodplain wetlands and streams occurs through surface or subsurface processes. Surface connections can be ephemeral and intermittent streams.
Morphological classification
In the US, the natural types of GIWS are: prairie pothole wetlands, playas, Nebraska's Rainwater Basin and Sandhills wetlands, West Coast vernal pools, sinkhole wetlands, Carolina bays, intradunal and interdunal wetlands, desert springs, endorheic basin in the Great Basin, and kettle-hole in glaciated regions.
Non-floodplain wetlands are classified in three categories which include GIWs: depressional wetlands, slope wetlands and flats wetlands. Depressional wetlands occur in topographic depressions with or without surface outlets. Depressional wetlands include kettle holes, potholes, vernal pools, playas lake and Carolina bays. Slope wetlands are located along hillslopes and are mainly recharged by groundwater inputs. Fens are the usual type of slope wetlands. Flats wetlands occur on large flat areas like interfluve, dried lake bottoms or large floodplain terraces. Large playas are a type of mineral soil-dominated flats. Flats wetlands can also be formed from organic soils, like peatbogs.
GIWs and non-floodplain wetlands can emerge from one or a combination of geomorphological processes: aeolian (potholes, playas, Rainwater basin, Carolina Bays, interdunal wetlands), (peri-)glacial (kettle, fens), karstic (sinkholes) and lacustrine (Carolina Bays, endorheic basin).
Relative abundance of vulnerable waters
Ephemeral and intermittent headwater streams and GIWs display the shortest drainage area and stream length, but together they can represent the major proportion of river networks and watersheds.
In the U.S., headwater streams represent more than 60% of the river network length and geographically isolated wetlands encompass about 16% of freshwater resources. In 17 states, there are streams with an intermittent-stream-length-over-total-length's ratio higher than 82%. North Dakota, South Dakota and Minnesota are the three states with the most hectares of geographically isolated wetlands. Many studies report that actual maps of U.S. hydrographic network underestimate the distribution of headwater streams
The approximate length of first to third order streams in the world is respectively 45 660 000, 22 061 000 and 10 660 100 km, and they represent the dominant Strahler' order of streams in the world.
Vulnerable water legal status
The legal status of ephemeral and intermittent headwater streams and GIWs differ from one legislation to another.
United States
In the US, Environmental Protection Agency (EPA) has, since 1972, the responsibility to regulate the waters of the United States, under the Clean Water Act (CWA). The Clean Water Act, introduced by president Richard Nixon, made clear that continental waters should be "swimmable and fishable" for the American public. That was a great step toward protection of riverine habitats and improvement of water quality.
Because of the U.S Constitution, the federal government can only protect interstate waters that is used for navigation, which is defined as the "waters of the United States" (WOTUS). From 1972 to 2015, the EPA defined WOTUS as:
"`[...] traditional navigable waters, interstate waters (including interstate wetlands), all other waters that could affect interstate or foreign commerce, impoundments of waters of the United States, tributaries, the territorial seas, and adjacent wetlands" (CWA, (33 CFR 328.3; 40 CFR 122.2)
The CWA defined wetlands as:
"[...] areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas." (CWA, section 404).
The definition of WOTUS was challenged in court several times, especially regarding the integration of isolated wetlands, but until the years 2000, the U.S. Federal Court stood by the initial definition saying that floodplain wetlands are bound to the streams they are adjacent to. Then, In 2001, a judgement ruled that isolated wetlands are not comprised in the WOTUS definition because they do not show "significant nexus" with navigable streams. In 2006, in the Rapanos vs. United States case, further confusion was created concerning the WOTUS definition. No majority decision was obtained, as two main opinions divided the judges. The first one, defended by Justice Antonin Scalia, was that the scope of the CWA only included permanent streams and wetlands with a significant surface connections with navigable streams. The second opinion, led by Justice Anthony Kennedy, was that waters have a significant nexus with navigable waters if they are significantly affecting their chemical, physical, and biological integrity.
The definition of WOTUS is actually under revision. The United States President, Donald Trump, signed the executive Order 13778 (82 FR 12495, March 3, 2017), asking the EPA and United States Army Corps of Engineers Corps to review the definition of WOTUS in a manner that is consistent with Justice Antonin Scalia's opinion. This opinion calls for protection of permanent waters and wetlands showing surface connections to relatively permanent waters, which exclude GIWS, and ephemeral/intermittent streams.
European Union
In the European Union (EU), since 2000, the Water Framework Directive (WFD) aims to achieve a number of objectives to improve water quality of lakes, rivers and coastal areas. Key objectives are general protection of the aquatic ecosystem, protection of drinking water resources, and protection of swimmable waters. These objectives are realized through river management measures at basin scale. The WFD requires the delineation of water bodies that will be targeted for specific diagnosis and management measures. The smallest area range considered to identify those water bodies is 10 to 100 km square. Due to their small size, headwater streams are not usually identified as one of the water bodies targeted by the WFD and, therefore, become more vulnerable to human activities.
Ecological functions
The U.S. Environmental Protection Agency (EPA) classifies headwater streams (including ephemeral/intermittent streams) and GIWs' ecological functions in five categories: source, sink, refuge, transformation and lag functions. These functions depend on the level of connectivity (hydrological, sedimentological, biological) in-between the sub-components of a river system (channel, floodplain, wetlands). Many functions are common among streams riverine wetlands and non-floodplain wetlands. Many more studies have been conducted on the role of headwater streams compared to GIWs.
Source function
Headwaters streams and GIWs represent the dominant sources of material and energy in river networks. They export water, sediment, nutrients, organic debris and organisms from the upland areas to the downstream portion of the river network.
Headwater streams are the dominant source of water in a river network. They supply water downstream that is essential to aquatic habitats. They contribute to flooding, and in doing so transfer sediments and nutrients to adjacent riverine habitats. Headwater streams are also typically erosion zones. They collect sediment from bank erosion and from colluvium in mountainous areas. Sediment inputs from headwater streams influence the dynamic equilibrium between runoff discharge and transport capacity, responsible for aggradation and degradation of channels. Headwater streams also collect wood, organic matter, nutrients and fine particles through erosion and flooding of riverine wetlands. Headwater streams provide rich-nutrient waters that benefit micro-organisms, like algae and invertebrates. For example, it was demonstrated that first-order streams contribute to 40% of nitrogen reaching fourth and fifth-order streams. It was also demonstrated that headwater streams are sources of invertebrates that benefit the whole food chain downstream: salmonidae are a good example of species that benefit. Headwater streams supply organic matter downstream that is essential to physical and biological processes throughout the river network. They also deliver wood logs and wood debris that exert an influence over channel morphology, runoff velocity and on the spatial distribution of ecological habitats.
GIWs can be the source of headwater streams. GIWs can provide the major proportion of stream's water in dry period. However, the process of water transfer from a GIWs to a stream is depending on antecedent moisture conditions prevailing in the GIWs. Under saturated conditions, GIWs will supply water to other downstream water bodies, including streams. There are abundant and diverse microbial populations in GIWs. Low pH, low salinity and presence of organic matter create favorable conditions for the development of sulfate-reducing bacteria. These bacteria are responsible for the production of methylmercury. GIWs are thus source of methylmercury, and other dissolved organic compounds and acids that can be transported downstream by temporary surface flows. Despite the fact the methylmercury is a particularly toxic pollutant, dissolved organic matter is a major source of energy for aquatic organisms located downstream in the river network.
Sink function
Sink function refers to the overall net import of energy and materials from the stream to the riparian environment or outside the stream network.
In natural settings, many exchanges of water occur between headwater streams and their riparian environments. Bed friction and friction with the riparian surface during overbank flows result in a net loss of flow energy, especially in mountainous streams with coarse bed loads. It results in net decrease of the erosion capacity of the stream in its downstream section. In the riparian zone, friction and shallow water depth contributes to decreases in flow velocity and to the deposition of suspended sediments. Meanwhile, a net loss of water from the flooded riparian environment to the atmosphere can occur through evaporation or by transpiration of vegetation. Intake of nitrogen by bacteria, as runoff water charged with nutrient penetrates the hyporheic zone, is another demonstration of headwater stream's sink function. Knight et al. (2010) determined that riverine wetlands acting as buffer are the most effective tool to mitigate the effect of non-point sources of pollution to streams.
GIWs, like riverine wetlands, can intercept nutrients and other pollutants from point-sources (ex. ditches, drainage pipes) or from diffuse (non-point) sources (ex. leaching from agricultural fields). Processes involved in capturing nutrients are various and include: the process of denitrification, phosphorus retention through plant assimilation and sorption or sedimentation processes. Removal of nutrients by GIWs has a great influence over water quality in stream networks. A study by Dierberg and Brezonik (1984) demonstrated that a forested non-floodplain wetland was responsible for removing 95% of phosphorus, nitrate, ammonium and total nitrogen after human sewage was applied. Under low-saturated conditions, GIWs will store water instead of releasing it. Storage of water and subsequent evapotranspiration will result in an overall loss of water for the stream network.
Refuge function
Refuge function refers to providing favorable conditions for many aquatic and terrestrial lifeforms.
Headwater streams and their riverine wetlands offer shelters from predation, drying, and extreme temperatures to many organisms. They provide habitats that are essential for the completion of a portion or of the full life cycle of fish species, macro-invertebrates, mammals, bird and amphibian species. Riverine wetlands display a mosaic of habitats due to the spatial heterogeneity of hydrological and morphological processes. The diversity of habitats and the abundance of food (see Source function) make riverine wetlands ideal feeding, breeding and shelter sites for fish species, amphibians and macroinvertebrates. Riverine wetlands also shelter a high diversity of plant species. Overbank flows within the floodplain are used by plants to disseminate their seeds In return, living organisms contribute to the spatial and temporal complexity of fluvial systems which is essential to maintaining a high level of connectivity between the streams and their riverine environment. For example, dams building by beaver create pools along headwater streams that eventually become suitable fish habitats and increase groundwater surface water interactions.
GIWs have been identified as breeding site for birds, fish species, mammals (muskrats, otters), amphibians and reptiles. Fish species benefit from the temporary rise of water levels and creation of surface connections to migrate from GIWs to streams or others wetlands. Mammals and bird species serve as transport vectors for the dissemination of plants seeds, algae and invertebrates.
Transformation function
Transformation function refers to the biogeochemical processing of organic and non-organic elements.
Nutrients entering headwater streams undergo many cycles of transformation through biological and chemical processes (absorption by algae, digestion by a fish, uptake by bacteria etc.). The cycling of nutrients through different forms and different compartments of the fluvial system is called “nutrient spiraling”. Organic matter will also undergo cycle of transformation in headwater streams, mainly through respiration by organisms and microbes. Other processes of transformation of organic matter, like dead leaves, include immersion, physical abrasion and photodegradation. The exchanges of water through the hyporheic zone of headwater streams can also mediate the form and mobility of pollutants, hereby decreasing pollutant concentrations downstream. In riverine wetlands, a lot of transformation processes occur in which nutrients and other compounds are lost to the atmosphere or sequestered in the soil or vegetation.
Transformation of elemental mercury to methylmercury is performed by microbial communities living in acidic wetlands (see Source function). Methylmercury is a toxic form of mercury that is very mobile and that accumulates in the food chain. Denitrification is another transformation process occurring in GIWs.
Lag function
Lag function refers to the transient storage of energy and materials. Because they are the dominant sources of water in stream network, headwater streams and wetlands have a great impact on the frequency, duration and magnitude of downstream transfer of materials and energy. The intensity of the lag function is correlated to the abundance and diversity of local storage components (wetlands, alluvial aquifers, stream banks and floodplains) and to the level of connectivity between these components.
In headwaters streams, flowing water interacts with channel bedforms, stream banks and vegetation. These interactions result in reduced flow velocity and transient storage of groundwater, which lessen the flood's magnitude during heavy precipitation events. On the other end, during the dry season, the transient storage and delayed transfer of groundwater to the stream will maintain a minimum baseflow essential for aquatic species. The same process applies for sediments, nutrients and organic matter being transported downstream from the upper areas of a watershed and being temporarily stored in the floodplain, including riverine wetlands. Living organisms present in headwater streams contribute to delaying the downstream transfer of sediments, nutrients and organic matter through consumption, assimilation, and bioconsolidation.
Transient storage of water in GIWs contributes to a delay in input of precipitation water to streams or other connected water bodies. Such a function secures the base flow of streams and contributes to recharging local and regional aquifers, especially during dry periods Transient storage in GIWs contributes also to lessening flood magnitude during heavy precipitation events or during melt periods. In contrast, because storage capacity is largely determined by antecedent moisture conditions, a saturated GIWs will convey water downstream rapidly, which could increase flood magnitude. Following this idea, GIWs can also reduce base flow, through storage and evapotranspiration, when saturation conditions are low.
References
Bodies of water
Wetlands | Vulnerable waters | [
"Environmental_science"
] | 3,895 | [
"Hydrology",
"Wetlands"
] |
56,269,992 | https://en.wikipedia.org/wiki/Environmental%20gentrification | Environmental, ecological or green gentrification is a process in which cleaning up pollution or providing green amenities increases local property values and attracts wealthier residents to a previously polluted or disenfranchised neighbourhood. Green amenities include green spaces, parks, green roofs, gardens and green and energy efficient building materials. These initiatives can heal many environmental ills from industrialization and beautify urban landscapes. Additionally, greening is imperative for reaching a sustainable future. However, if accompanied by gentrification, these initiatives can have an ambiguous social impact. More specifically, in certain cases the introduction of green amenities might lead to (1) the physical displacement of low income households due to soaring housing costs, and/or (2) the cultural, social, and political displacement of long-time residents. First coined by Sieg et al. (2004), environmental gentrification is a relatively new concept, although it can be considered as a new hybrid of the older and wider topics of gentrification and environmental justice. Social implications of greening projects specifically with regards to housing affordability and displacement of vulnerable citizens. Greening in cities can be both healthy and just.
Definition
Environmental gentrification is the process by which efforts to improve urban environments, such as enhancing green spaces or reducing pollution, increase property values and living costs, often displacing lower-income residents and attracting wealthier populations. The introduction of green spaces in urban areas has historically led to increases in property values, which can displace long-term residents. This process, referred to as environmental gentrification, occurs when low-income residents are priced out of their neighborhoods as a result of urban green space developments and the lack of housing development for additional people who wish to live in the area. Environmental gentrification is commonly understood as the process in which urban green space improvements lead to the displacement of lower-income communities, although the exact definition remains a topic of debate. Green gentrification is closely related to urban planning and climate mitigation efforts. Strategies such as installing shade structures, green walls, green roofs, and water features are often implemented to combat the urban heat island effect. However, these improvements can lead to higher property values and subsequent displacement. Studies have shown a correlation between the creation of urban green spaces and increases in housing prices when there is inadequate housing supply to meet local or regional demand. For instance, property prices around the High Line in New York City increased by 35% with the current renovations, while prices near Chicago's Bloomingdale Trail rose by 13.8% to 48.2% with the implementation of the newly constructed greenery.
Gentrification
Gentrification is a process whereby a neighborhood is transformed in order to cater to a wealthier home buyer or investor. The process often takes place in working-class neighborhoods that are inhabited by low-income residents. Real-estate development such as luxury condominiums or the transformation of old factories into trendy lofts, attract wealthier investors. As the process progresses, low-income residents are pushed out or to the outskirts of the neighborhood as real-estate and rent prices are increased due to demand. Also, as middle-class residents enter the neighbourhood surrounding businesses transform to accommodate desires. Gentrification has often been promoted by local governments through policies that promote 'urban renewal.' Generally, the process is considered to benefit the local economy and improve neighborhoods.
Three phases of gentrification in North America have been recognized:
1960s–1970s – A process led by the government, which hoped to reinvest capital to the inner city.
1970s – Widespread in big cities and spreading to smaller towns across North America. An example is the promotion of art communities such as Soho Manhattan to attract residents and investors.
1990s – Extensive large-scale development increased in scale and complexity through public-private partnerships.
As wealthier citizens have started to demand green amenities, cities have shifted their focus to marrying urban redevelopment with green initiatives all of which follow a similar process. Some of these initiatives can be seen through changes in various infrastructure, people changing their means of transportation to things such as biking and walking, as well as the displacement of people, all of which may lead to the gentrification of a neighborhood.
Urban planning and sustainability
Sustainability is used by governments and developers to promote green initiatives and urban green space. Originally growing from the promotion of sustainable development in developing countries, sustainability gained global recognition following the 1992 United Nations Earth Summit, which introduced the 17 Sustainable Development Goals (SDGs). The concept of sustainability is based on achieving a balance between three pillars: economy, environment, and social equity. However, implementing this balance in practice remains challenging. Criticism arises on how well urban sustainability efforts promote social equity, as many development projects do not account for the impact that economic growth has on the existing community.
The social equity aspect of sustainability focuses on enabling local communities to participate in decision-making processes and benefit from development projects. Public participation is intended to ensure that the needs and concerns of local residents are met. The redevelopment of brownfield sites, including post-industrial areas and abandoned lots, has become a key element of large-scale urban greening projects. These sites, which are often located near downtown areas or waterfronts, typically require environmental remediation and are supported by economic incentives from various governmental bodies. These redevelopments frequently promote sustainability through urban planning mechanisms like new urbanism, which emphasizes the creation of cities that are livable, self-sustaining, cooler, and walkable.
Cities and individuals are increasingly responding to ecological challenges through eco-friendly planning and initiatives. Cities such as Chicago, with the Bloomingdale Trail (606), and New York City, with The High Line, have introduced green spaces into densely populated areas to enhance greenery and provide urban green spaces. According to estimates from the United Nations, around 54% of the world's population currently lives in urban areas, with this figure expected to rise to 66% by 2050. Cities can be understood as functioning like metabolic organisms, extracting, using, and disposing of resources over time. The study of urban environments can reveal patterns of spatial inequality, such as the observed negative correlation between the provision of green spaces and the presence of African-American and Hispanic populations in the United States. Green spaces in these neighborhoods are often less maintained and policed, while those in more affluent areas tend to support activities for wealthier residents, to maintain a certain social order.
Gentrification and environmental justice in the United States
Environmental gentrification is a topic that intersects with environmental justice. The areas that are redeveloped with the intent of adding more environmentally friendly parks and greenspaces, are generally selected because the neglected property that can be purchased for a lower cost. With the purchase of cheaper property and land, the intent to renovate and fix up these properties with the intent to eventually make a profit is clear. These properties are often in zones that are predominantly occupied by people of racial and ethnic minority, and were strategically zoned in areas more susceptible and proximal to toxic waste disposal as well as other types of contamination. Despite these disproportionate effects, it does not appear to influence the actions of the Environmental Protection Agency (EPA) in terms of determining priority for interventions. As neighborhoods are cleaned up through Superfund cleanup programs, there are noticeable changes that have the tendency to follow, such as an increased number of people that move to the area, with more financial resources and higher levels of education. As people with more financial resources move in, the previous residents are slowly pushed out as the costs of living become less affordable in comparison to before the development and gentrification of the area. Typically these neighborhoods are overtaken by a greater white population, resulting in the whitewashing of a neighborhood. As neighborhoods gain more of a white population, there are increased instances of citizen-based policing of the youth, such as not only profiling, but also the baseless calling of law enforcement, disproportionately targeting people of color. It has been seen that in larger plans to develop various areas, nonprofit organizations that focus on park development and greenspaces are relied upon, and due to their lack of specialty with the development of infrastructure, the consequences of gentrification such as the lack of affordable housing went ignored as parks were built.
Urban green spaces are areas that are in an open space with the looks of a natural environment with greenery and at times water features.Green spaces do promote an aesthetically pleasing look and physical activity amongst people in the community, which promotes physical and mental well-being. Green gentrification is applied to green spaces based on the accessibility of these improvements. Green spaces, such as parks and fields, can be placed in an unsafe neighborhood or a neighborhood that is disproportionately wealthy area, when there are areas with little to no green areas. Moreover, the lack of green spaces in low income, urban areas green gentrification due to these communities at present struggling with financial matters. The promotion of green areas has a positive effect on the communities, and the imbalance of greenery in wealthy versus low-income areas exhibits environmental injustice. Studies have shown green spaces in urban areas to have an effect on climate and health risks by lowering local temperature and improving air quality.
Examples
Barcelona
Sant Martí District
A 15-year study (1990–2005) examined the social impacts or enhancing urban green spaces across the city of Barcelona. During the 1990s and 2000s, 18 new urban green parks were added to the city planning agenda. First and foremost, as Barcelona was awarded the 1992 Olympic Games, the city prepared for the event through numerous urban developments which influenced a transformation of public spaces. Previously, the city had been concerned with providing urban parks for the purpose of socializing and exercising. However, as the Olympics were swiftly approaching, urban planners and city governments took the opportunity to develop green spaces for mega-events. These new types of spaces prioritize the aesthetic features of urban green space in an effort to attract tourists and offer memorable landscapes. The legacy of mega-event urban parks can be observed in three notable parks around the city – Parc del Port Olimpic, Parc del Poblenou and Parc de Diagnol Mar. All three of these parks have shifted neighborhood demographics towards greater affluence.
The city of Barcelona released its plan for sustainability titled Barcelona Green Infrastructure and Biodiversity Plan 2020. This document does not contain plans for housing affordability or social impacts that are a result from large-scale development. Diagonal Mar project provides an example of the green initiatives being coupled with large-scale urban redevelopment on a previous brownfield site. Historically, the area was an industry hub as it is located near the Mediterranean Sea. The Diagonal Mar project includes luxury condominiums, three hotels, three office buildings, a shopping mall nested within an urban green space. The project has been criticized for not considering local input into planning as lacking spaces for social interactions for citizens.
Studies suggest that green gentrification has occurred in correspondence with park development in the Sant Marti district. Using neighborhood measurements of wealth, the authors suggest that demographic shifts of the neighborhood have taken place at an alarming rate 1990–2005. Moreover, areas surrounding parks have experienced clear indicators of these changes as there has been an increase in: residents with a bachelor's degree, residents from the global North, household income or home sale and an overall decrease in the population of residents 65 and older living alone.
New York City
The High Line
The High Line is a 1.45-mile-long (2.33 km) an elevated public park that was constructed on a historic freight line along the west side of Manhattan in New York City. Previous to its redevelopment, the High Line represented the deterioration of New York's industry, the neighborhood of alongside the High Line, Chelsea, had frequent delinquency. Since the 1980s the city government has attempted to tear it down. In response, activists ventured to save the High Line and proposed that it could be returned to the community as a provision of public good. As the High Line was acquired by the CSX Transportation Inc. in 1999, community board meetings provided an avenue for alternative uses to be proposed. At around the same time, Joshua David and Robert Hammond formed a non-profit they called Friends of the High Line with the main goal of to acquiring public and private funds to save the bridge from demolition. Notable celebrities – Edward Norton, Martha Stewart and Kevin Bacon provided financial support for the project. Friends of the High Line presented a redevelopment strategy to the Bloomberg administration, suggesting that the bridge could be converted into a public park, arguing that this would provide economic benefits to the surrounding neighborhood and generate substantial tax revenues. The Bloomberg administration accepted the initiative, and Mayor Bloomberg provided a statement of support by stating, "The Board's ruling is a great win for all New Yorkers. It allows us to implement our plans to preserve this valuable historic resource, create a much needed public open space and strengthen our city's economy."
Evidence that this project has ignited gentrification can be observed through the soaring real estate prices as well as types of activities that are being attracted to the High Line and its surrounding areas. In just two years, there has been a production of $2 billion real-estate construction which has contributed an additional $900 million in tax revenues. Additionally, the relocation of Whitney Museum of American Art nearby sheds light on the popularity of the park.
The High Line, although presented as a public park, privileges certain users and activities. Friends of the High Line allow for only certain types of vendors as well as provides private security guards. Visitors of the High Line can enjoy artisanal foods, micro-brewed beer and browse up-scaled art merchant booths. The promotion of economic growth and certain types of consumption coupled with surveillance results in the neoliberalization of this public spaces. The High Line, although a famous icon for the city, may fall short of providing open spaces and benefits for all citizens to use and enjoy. Instead it more closely resembles a place of spatial 'privilege' where claims to public space are dominated by upper-class citizens.
Concurrently in 2007, the Bloomberg administration released the PlaNYC 2030: A Greater, Greener New York which aimed to combat climate change through expanding sustainability measured with 132 initiatives. One goal highlights the social pillar of sustainability by having a goal that every citizen in the city will have a green space within a 10-minute walking distance from their home.
Vancouver
False Creek
The traditional urban layout of Vancouver was reminiscent of a small town. Grid-iron patterned streets were lined with single-family dwellings, businesses could be found along main streets and industry was concentrated along shorelines and inlets. The 1960s ushered in a shift towards higher densities through high rise residential buildings in the downtown core. In the 1980s, redevelopment of brownsites (former industrial areas) for condominium development in the False Creek region was a result of it being the site for Expo 1986. Previously, this area was the heartland of industry and had begun to deteriorate as industry shifted. After the Expo, the site was acquired by Hong Kong billionaire Li Ka-Shing for $320 million and a numerous residential luxury developments followed suite. These developments promoted a tone of sustainability that were supported through planning documents such as Livable Region Strategic Planning (1996). Urban planning strategies such as smart growth stressed environmental goals could be achieved through the provision of walkable and mixed-use urban areas which would reduce urban sprawl. Critiques of smart growth highlight the equity aspects of the strategy, as it often ignores low-income residents. Housing affordability became an issue during 2001–2007 as the price for a typical two-bedroom in the west end of Vancouver shifted from $260,000 to $650,000. In 2008, the city council accepted EcoDensity as a solution to housing affordability which promoted further densification of downtown and surrounding neighbourhoods. EcoDensity is the solution to housing affordability rather than provision of social housing. A number of towers were constructed in the downtown Eastside displaced approximately 4,000 low-income residents from June 2007 – January 2008. Critiques of EcoDensity suggest that the strategy does not account for enough citizen input in planning measures.
Vancouver has become one of the most popular cities in the world to live as it offers breathtaking mountain views and access to numerous beaches. As Vancouver was awarded the 2010 Winter Olympics, which led to the development of "Millenium Water" along the South Eastern portion of False Creek which became the site for the Olympic Athlete Village. This project boasted European-styled walkways, green roofs and sustainability characteristics. No low-income housing was provided with this project and one-bedroom condos starting price was $500,000. In an effort to reduce ecological impacts, the project promoted a habitat restoration project whereby leftover dirt was used to create an island for bird nesting. In 2006, water squatters, people living in boats in False Creek waters, were evicted in an effort to clean up the area. The False Creek redevelopment was advertised as a park-like nature for new residents and tourists and promoted as a space for leisure. Scholars suggest that there is a disconnect between the promotion of environmental discourses and issues of equity which results in a class conflict over space in the city. Although Vancouver is a highly desirable place to live, the promotion of sustainability through policies ignores provision of much needed affordable housing allocations.
References
Gentrification
Urban planning | Environmental gentrification | [
"Engineering"
] | 3,560 | [
"Urban planning",
"Architecture"
] |
56,272,178 | https://en.wikipedia.org/wiki/Carbon%20budget | A carbon budget is a concept used in climate policy to help set emissions reduction targets in a fair and effective way. It examines the "maximum amount of cumulative net global anthropogenic carbon dioxide () emissions that would result in limiting global warming to a given level". It can be expressed relative to the pre-industrial period (the year 1750). In this case, it is the total carbon budget. Or it can be expressed from a recent specified date onwards. In that case it is the remaining carbon budget.
A carbon budget that will keep global warming below a specified temperature limit is also called an emissions budget or quota, or allowable emissions. Apart from limiting the global temperature increase, another objective of such an emissions budget can be to limit sea level rise.
Scientists combine estimates of various contributing factors to calculate the carbon budget. The estimates take into account the available scientific evidence as well as value judgments or choices.
Global carbon budgets can be further sub-divided into national emissions budgets. This can help countries set their own emission goals. Emissions budgets indicate a finite amount of carbon dioxide that can be emitted over time, before resulting in dangerous levels of global warming. The change in global temperature is independent of the source of these emissions, and is largely independent of the timing of these emissions.
To translate global carbon budgets to the country level, a set of value judgments have to be made on how to distribute the remaining carbon budget over all the different countries. This should take into account aspects of equity and fairness between countries as well as other methodological choices. There are many differences between nations, such as population size, level of industrialisation, historic emissions, and mitigation capabilities. For this reason, scientists are attempting to allocate global carbon budgets among countries using various principles of equity.
Definition
The IPCC Sixth Assessment Reports defines carbon budget as the following two concepts:
"An assessment of carbon cycle sources and sinks on a global level, through the synthesis of evidence for fossil fuel and cement emissions, emissions and removals associated with land use and land-use change, ocean and natural land sources and sinks of carbon dioxide (CO2), and the resulting change in atmospheric CO2 concentration. This is referred to as the global carbon budget."; or
"The maximum amount of cumulative net global anthropogenic CO2 emissions that would result in limiting global warming to a given level with a given probability, taking into account the effect of other anthropogenic climate forcers. This is referred to as the total carbon budget when expressed starting from the pre-industrial period, and as the remaining carbon budget when expressed from a recent specified date."
Global carbon budgets can be further divided into national emissions budgets, so that countries can set specific climate mitigation goals.
An emissions budget may be distinguished from an emissions target, as an emissions target may be internationally or nationally set in accordance with objectives other than a specific global temperature and are commonly applied to the annual emissions in a single year as well.
Estimations
Recent and currently remaining carbon budget
Several organisations provide annual updates to the remaining carbon budget, including the Global Carbon Project, the Mercator Research Institute on Global Commons and Climate Change (MCC) and the CONSTRAIN project. In March 2022, before formal publication of the "Global Carbon Budget 2021" preprint, scientists reported, based on Carbon Monitor (CM) data, that after COVID-19-pandemic-caused record-level declines in 2020, global emissions rebounded sharply by 4.8% in 2021, indicating that at the current trajectory, the carbon budget for a ⅔ likelihood for limiting warming to 1.5 °C would be used up within 9.5 years.
In April 2022, the now reviewed and officially published The Global Carbon Budget 2021 concluded that fossil emissions rebounded from pandemic levels by around +4.8% relative to 2020 emissions – returning to 2019 levels.
It identifies three major issues for improving reliable accuracy of monitoring, shows that China and India surpassed 2019 levels (by 5.7% and 3.2%) while the EU and the US stayed beneath 2019 levels (by 5.3% and 4.5%), quantifies various changes and trends, for the first time provides models' estimates that are linked to the official country GHG inventories reporting, and suggests that the remaining carbon budget at 1. Jan 2022 for a 50% likelihood to limit global warming to 1.5 °C (albeit a temporary exceedence is to be expected) is 120 GtC (420 Gt) – or 11 years of 2021 emissions levels.
This does not mean that likely 11 years remain to cut emissions but that if emissions stayed the same, instead of increasing like in 2021, 11 years of constant GHG emissions would be left in the hypothetical scenario that all emissions suddenly ceased in the 12th year. (The 50% likelihood may be describable as a kind of minimum plausible deniability requirement as lower likelihoods would make the 1.5 °C goal "unlikely".) Moreover, other trackers show (or highlight) different amounts of carbon budget left, such as the MCC, which as of May 2022 shows "7 years 1 month left" and different likelihoods have different carbon budgets: a 83% likelihood would mean 6.6 ±0.1 years left (ending in 2028) according to CM data.
In October 2023 a group of researchers updated the carbon budget including the CO2 emitted at 2020-2022 and new findings about the role of reduced presence of polluting particles in the atmosphere. They found we can emit 250 GtCO2 or 6 years of emissions at current level starting from January 2023, for having a 50% chance to stay below 1.5 degrees. For reaching this target humanity will need to zero CO2 emissions by the year 2034. To have a 50% chance of staying below 2 degrees humanity can emit 1220 Gt or 30 years of emissions at current level.
Carbon budget in gigatonnes and factors
The finding of an almost linear relationship between global temperature rise and cumulative carbon dioxide emissions has encouraged the estimation of global emissions budgets in order to remain below dangerous levels of warming. Since the pre-industrial period (year 1750) to 2019, approximately 2390 Gigatonnes of (Gt ) has already been emitted globally.
Scientific estimations of the remaining global emissions budgets/quotas differ due to varied methodological approaches, and considerations of thresholds. Estimations might not include all amplifying climate change feedbacks, although the most authoritative carbon budget assessments as summarised by the IPCC do account explicitly for these. Scientists assess the size of remaining carbon budgets using estimates of:
past warming caused by human activities,
the amount of warming per cumulative unit of CO2 emissions (also known as the Transient Climate Response to cumulative Emissions of carbon dioxide, or TCRE),
the amount of warming that could still occur once all emissions of CO2 are halted (known as the Zero Emissions Commitment), and
the impact of Earth system feedbacks that would otherwise not be covered.
The estimates vary according to the global temperature target that is chosen, the probability of staying below that target, and the emission of other non- greenhouse gases (GHGs). This approach was first applied in the 2018 Special report on Global Warming of 1.5 °C by the IPCC, and was also used in its 2021 Working Group I Contribution to the Sixth Assessment Report.
Carbon budget estimates depend on the likelihood or probability of avoiding a temperature limit, and the assumed warming that is projected to be caused by non- emissions. These estimates assume non- emissions are also reduced in line with deep decarbonisation scenarios that reach global net zero emissions. Carbon budget estimates thus depend on how successful society is in reducing non- emissions together with carbon dioxide emissions. Scientists estimated that remaining carbon budgets can be 220 Gt higher or lower depending on how successful non- emissions are reduced.
National emissions budgets
Carbon budgets are applicable to the global level. To translate these global carbon budgets to the country level, a set of value judgments have to be made on how to distribute the total and remaining carbon budget. In light of the many differences between nations, including but not limited to population, level of industrialisation, national emissions histories, and mitigation capabilities, scientists have made attempts to allocate global carbon budgets among countries using methods that follow various principles of equity. Allocating national emissions budgets is comparable to sharing the effort to reduce global emissions, underlined by some assumptions of state-level responsibility of climate change. Many authors have conducted quantitative analyses which allocate emissions budgets, often simultaneously addressing disparities in historical GHG emissions between nations.
One guiding principle that is used to allocate global emissions budgets to nations is the principle of "common but differentiated responsibilities and respective capabilities" that is included in the United Nations Framework Convention on Climate Change (UNFCCC). This principle is not defined in further detail in the UNFCCC but is broadly understood to recognize nations' different cumulative historical contributions to global emissions as well as their different development stages. From this perspective, those countries with greater emissions during a set time period (for example, since the pre-industrial era to the present) are the most responsible for addressing excess emissions, as are countries that are richer. Thus, their national emissions budgets have to be smaller than those from countries that have polluted less in the past, or are poorer. The concept of national historical responsibility for climate change has prevailed in the literature since the early 1990s and has been part of the key international agreements on climate change (UNFCCC, the Kyoto Protocol and the Paris Agreement). Consequently, those countries with the highest cumulative historical emissions have the most responsibility to take the strongest actions and help developing countries to mitigate their emissions and adapt to climate change. This principle is recognized in international treaties and has been part of the diplomatic strategies by developing countries, that argue that they need larger emissions budgets to reduce inequity and achieve sustainable development.
Another common equity principle for calculating national emissions budgets is the "egalitarian" principle. This principle stipulates individuals should have equal rights, and therefore emissions budgets should be distributed proportionally according to state populations. Some scientists have thus reasoned the use of national per-capita emissions in national emissions budget calculations. This principle may be favoured by nations with larger or rapidly growing populations, but raises the question whether individuals can have a right to pollute.
A third equity principle that has been employed in national budget calculations considers national sovereignty. The "sovereignty" principle highlights the equal right of nations to pollute. The grandfathering method for calculating national emissions budgets uses this principle. Grandfathering allocates these budgets proportionally according to emissions at a particular base year, and has been used under international regimes such as the Kyoto Protocol and the early phase of the European Union Emissions Trading Scheme (EU ETS) This principle is often favoured by developed countries, as it allocates larger emissions budgets to them. However, recent publications highlight that grandfathering is unsupported as an equity principle as it "creates 'cascading biases' against poorer states, is not a 'standard of equity'". Other scholars have highlighted that "to treat states as the owners of emission rights has morally problematic consequences".
Pathways to stay within carbon budget
The steps that can be taken to stay within one's carbon budget are explained within the concept of climate change mitigation.
See also
Global Carbon Project
References
External links
Global Carbon Project
The CONSTRAIN Project - 4-year project (2020 to 2024) funded by European Union Horizon 2020
Greenhouse gas emissions
Environmental science
Climate change mitigation | Carbon budget | [
"Chemistry",
"Environmental_science"
] | 2,371 | [
"Greenhouse gases",
"Greenhouse gas emissions",
"nan"
] |
56,273,710 | https://en.wikipedia.org/wiki/NGC%20516 | NGC 516 is a lenticular galaxy located in the constellation of Pisces. It was discovered on September 25, 1862 by Heinrich d'Arrest.
See also
Lenticular galaxy
List of NGC objects (1–1000)
Pisces (constellation)
References
External links
SEDS
0516
00946
005148
+01-04-048
18620925
NGC 516
NGC 516
Discoveries by Heinrich Louis d'Arrest | NGC 516 | [
"Astronomy"
] | 90 | [
"Pisces (constellation)",
"Constellations"
] |
56,274,386 | https://en.wikipedia.org/wiki/List%20of%20codes%20used%20in%20the%20World%20Geographical%20Scheme%20for%20Recording%20Plant%20Distributions | The World Geographical Scheme for Recording Plant Distributions (WGSRPD) is a biogeographical system developed by the international Biodiversity Information Standards (TDWG) organization, formerly the International Working Group on Taxonomic Databases. The system provides clear definitions and codes for recording plant distributions at four scales or levels, from "botanical continents" down to parts of large countries. Current users of the system include the International Union for Conservation of Nature (IUCN), and the Germplasm Resources Information Network (GRIN). Plants of the World Online uses Kew's data sources, and hence also uses the WGSRPD for distributions.
Codes
The table is arranged in the systematic order used in the WGSRPD. The levels used in the scheme are:
Nine botanical continents; the code consists of a single digit
Regions – each botanical continent is divided into between two and ten sub-continental regions; a two-digit code is used for regions, in which the first digit is the continent
Areas or "botanical countries" – most regions are subdivided into units, generally equating to a political country, but large countries may be split or outlying areas omitted; a three-letter code is used for areas
"Basic recording units" – the lowest level is only used for very large "botanical countries", subdividing them into states, provinces or islands on purely political grounds; the full code is made up of a two-letter code appended to the corresponding area code
See also
Biogeography
Phytochorion
Phytogeography
Wikipedia categories for flora distributions using the World Geographical Scheme for Recording Plant Distributions
Flora categories with a WGSRPD code
References
External links
Biogeography
World Geographical Scheme for Recording Plant Distributions | List of codes used in the World Geographical Scheme for Recording Plant Distributions | [
"Biology"
] | 349 | [
"Biogeography"
] |
56,274,829 | https://en.wikipedia.org/wiki/Yuan%20Chengye | Yuan Chengye (; 1924–2018) was a Chinese organic chemist.
Yuan was born in Shangyu, Zhejiang province in 1924. He graduated from the National College of Pharmacy (now China Pharmaceutical University) in 1948 and received a Degree for Candidate for D.Sc from the All-Union Research Institute of Pharmaceutical Chemistry, in Moscow in 1955. He worked at the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences after returning to China. He led a research team for nuclear fuel extractants since 1958. In 1997, he was elected an academician of the Chinese Academy of Sciences. He died on 9 January 2018.
References
1924 births
2018 deaths
Chemists from Zhejiang
China Pharmaceutical University alumni
Members of the Chinese Academy of Sciences
Chinese organic chemists
People from Shangyu
Scientists from Shaoxing | Yuan Chengye | [
"Chemistry"
] | 159 | [
"Organic chemists",
"Chinese organic chemists"
] |
51,956,258 | https://en.wikipedia.org/wiki/C12H14N4O4S | {{DISPLAYTITLE:C12H14N4O4S}}
The molecular formula C12H14N4O4S (molar mass: 310.33 g/mol, exact mass: 310.0736 u) may refer to:
Sulfadimethoxine
Sulfadoxine | C12H14N4O4S | [
"Chemistry"
] | 68 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
51,956,597 | https://en.wikipedia.org/wiki/Agmata | Agmata is a proposed extinct phylum of small animals with a calcareous conical shell. They were originally thought to be cephalopods or annelid worms. The living animals filled up to five-sixths of their shell with laminae, angled layers composed of grains of quartz or calcium carbonate detritus from the environment cemented together, with larger grains near the shell wall and smaller grains near the center. A very fine tube ran through the center of the shell. The grains may be of quartz or calcium carbonate, but are of specific shapes and materials that are rare in the surrounding rock. Though the body of the living animal is not preserved, it had to be able to find, choose, and retrieve rare grains from its environment to build the laminae.
The phylum's name comes from the Greek word for "fragments", referring to these fine fragments and grains of detritus. It was proposed by the paleontologist and geologist (1928–2006) in 1977 to house the agglutinating Early Cambrian fossils Salterella and Volborthella, with the Middle Cambrian Ellisell yochelsoni later included. The poorly known Middle Cambrian fossil Vologdinella was also considered for inclusion, as it has superficial resemblance to the Agmata, but was later excluded from the group.
Currently, the phylum contains only one family, Salterellidae; a second family, Volborthellidae, was originally included but later became a synonym of the former. No orders, classes or superfamilies are used within the phylum, despite the order "Volborthellida" being previously proposed for Volborthella before the phylum's own proposal. The reasoning for this was that taxa of these ranks were not seen as necessary in a phylum with very few genera.
The genera within the group are clearly different: Salterella had a pointed shell made of calcium carbonate with a thin outer layer and a thick inner layer, and secreted a calcium carbonate cement to hold its grains in place. Volborthella was the older genus, had a blunter shell with a shallower opening, and cemented grains in place with organic material that also may have formed the outside surface of the shell.
Fossils are found in large numbers in some areas. Paleontologists have offered several different ideas of how these animals lived: filter-feeding with the points of the shells embedded in the substrate, grazing actively like snails, or lying on their sides on the substrate. Volborthella is found in silt and clay deposits, and apparently lived on tidal mudflats. Attempts to reconcile these genera as members of any other group have been rejected due to basic differences in structure, but not all paleontologists accept them as a phylum; Jones (2007) considers the shell an agglutinating test parallel to that of foraminifers. Yochelson considered Agmata to be complex multicellular animals.
References
Cambrian fossil record
Animal phyla
Controversial taxa | Agmata | [
"Biology"
] | 620 | [
"Biological hypotheses",
"Controversial taxa"
] |
51,959,005 | https://en.wikipedia.org/wiki/Fast%20sweeping%20method | In applied mathematics, the fast sweeping method is a numerical method for solving boundary value problems of the Eikonal equation.
where is an open set in , is a function with positive values, is a well-behaved boundary of the open set and is the Euclidean norm.
The fast sweeping method is an iterative method which uses upwind difference for discretization and uses Gauss–Seidel iterations with alternating sweeping ordering to solve the discretized Eikonal equation on a rectangular grid. The origins of this approach lie in the paper by Boue and Dupuis. Although fast sweeping methods have existed in control theory, it was first proposed for Eikonal equations by Hongkai Zhao, an applied mathematician at the University of California, Irvine.
Sweeping algorithms are highly efficient for solving Eikonal equations when the corresponding characteristic curves do not change direction very often.
References
See also
Fast marching method
Numerical differential equations
Partial differential equations
Hyperbolic partial differential equations | Fast sweeping method | [
"Mathematics"
] | 195 | [
"Applied mathematics",
"Applied mathematics stubs"
] |
51,960,138 | https://en.wikipedia.org/wiki/Retardation%20time | Retardation is the delayed response to an applied force or stress, which can be described as "delay of the elasticity".
Ideal elastic materials show an immediate deformation after applying a jump-like stress, and an immediate reformation after removing the stress afterwards in the jump-like form again. For viscoelastic samples, this elastic behaviour occurs with a certain time delay.
The term "relaxation time" has been described. It is used in combination with tests presetting the strain (deformation) or strain rate (shear rate), e.g., when performing relaxation tests.
On the other hand, the term "retardation time" is used for tests when presetting the stress, e.g., when performing creep tests.
See also
Creep-testing machine
References
Rheology | Retardation time | [
"Physics",
"Chemistry"
] | 164 | [
"Classical mechanics stubs",
"Classical mechanics",
"Rheology",
"Fluid dynamics"
] |
51,960,491 | https://en.wikipedia.org/wiki/C%20band%20%28infrared%29 | In infrared optical communications, C-band (C for "conventional") refers to the wavelength range 1530–1565 nm, which corresponds to the amplification range of erbium doped fiber amplifiers (EDFAs). The C-band is located around the absorption minimum in optical fiber, where the loss reaches values as good as 0.2 dB/km, as well as an atmospheric transmission window (see figures). The C-band is located between the short wavelengths (S) band (1460–1530 nm) and the long wavelengths (L) band (1565–1625 nm). It includes the 50 GHz-spaced DWDM ITU channels 16 (1564.68 nm, 191.6 THz) to 59 (1530.33 nm, 195.9 THz).
References
Infrared
Optical communications | C band (infrared) | [
"Physics",
"Engineering"
] | 177 | [
"Optical communications",
"Telecommunications engineering",
"Spectrum (physical sciences)",
"Electromagnetic spectrum",
"Infrared"
] |
51,960,492 | https://en.wikipedia.org/wiki/C%20band%20%28IEEE%29 | The C band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4.0 to 8.0 gigahertz (GHz). However, the U.S. Federal Communications Commission C band proceeding and auction, designated 3.7–4.2 GHz as C band. The C band is used for many satellite communications transmissions, some cordless telephones, as well as some radar and weather radar systems.
The C band contains the 5.725 - 5.875 GHz ISM band allowing unlicensed use by low power devices, such as garage door openers, wireless doorbells, and baby monitors. A very large use is by the high frequency (5.2 GHz) band of Wi-Fi (IEEE 802.11a) wireless computer networks. These are the most widely used computer networks in the world, used to allow laptops, smartphones, printers and TVs to connect to the internet through a wireless router in home and small office networks, and access points in hotels, libraries, and coffee shops.
Use in satellite communication
The communications C band was the first frequency band that was allocated for commercial telecommunications via satellites. The same frequencies were already in use for terrestrial microwave radio relay chains. Nearly all C-band communication satellites use the band of frequencies from 3.7 to 4.2 GHz for their downlinks, and the band of frequencies from 5.925 to 6.425 GHz for their uplinks. Note that by using the band from 3.7 to 4.0 GHz, this C band overlaps somewhat with the IEEE S band for radars.
The C-band communication satellites typically have 24 radio transponders spaced 20 MHz apart, but with the adjacent transponders on opposite polarizations such that transponders on the same polarization are always 40 MHz apart. Of this 40 MHz, each transponder utilizes about 36 MHz. The unused 4.0 MHz between the pairs of transponders act as guard bands for the likely case of imperfections in the microwave electronics.
One use of the C band is for satellite communication, whether for full-time satellite television networks or raw satellite feeds, although subscription programming also exists. This use contrasts with direct-broadcast satellite, which is a completely closed system used to deliver subscription programming to small satellite dishes that are connected with proprietary receiving equipment.
The satellite communications portion of the C band is highly associated with television receive-only satellite reception systems, commonly called "big dish" systems, since small receiving antennas are not optimal for C band. Typical antenna sizes on C-band-capable systems range from 6 to 12 feet (1.8 to 3.5 meters) on consumer satellite dishes, although larger ones also can be used. For satellite communications, the microwave frequencies of the C band perform better under adverse weather conditions in comparison with the Ku band (11.2–14.5 GHz), microwave frequencies used by other communication satellites. Rain fade the collective name for the negative effects of adverse weather conditions on transmission is mostly a consequence of precipitation and moisture in the air.
Other uses of C-band frequencies
The C band also includes the 5.8 GHz ISM band between 5.725 and 5.875 GHz, which is used for medical and industrial heating applications and many unlicensed short-range microwave communication systems, such as cordless phones, baby monitors, and keyless entry systems for vehicles. The C-band frequencies of 5.4 GHz band [5.15 to 5.35 GHz, 5.47 to 5.725 GHz, or 5.725 to 5.875 GHz, depending on the region of the world] are used for Wi-Fi wireless computer networks in the 5 GHz spectrum.
C-Band Alliance
The C-Band Alliance was an industry consortium of four large communications satellite operators in 2018–2020.
In response to a Notice of Proposed Rulemaking of July 2018 from the US Federal Communications Commission (FCC) to make the 3.7 to 4.2 GHz spectrum available for next-generation terrestrial fixed and mobile broadband
services, the C-Band Alliance (CBA) was established in September 2018 by the four satellite operators—Intelsat, SES, Eutelsat and Telesat—that provide the majority of C-band satellite services in the US, including media distribution reaching 100 million US households. The consortium made a proposal to the FCC to act as a facilitator for the clearing and repurposing of a 200 MHz portion of C-band spectrum to accelerate the deployment of next generation 5G services, while protecting incumbent users and their content distribution and data networks in the US from potential interference.
The C-Band Alliance lobbied for a private sale, but the FCC and some members of Congress wanted an auction. In November 2019, the FCC announced that an auction was planned, which took place in December 2020. Cable operators wanted to be compensated for the loss of 200 MHz, which would not include a guard band of 20 MHz to prevent interference.
By late 2019, the commercial alliance had weakened. Eutelsat formally pulled out of the consortium in September 2019 over internal disagreements. By February 2020, it became even less of a factor in C-band spectrum reallocation as Intelsat pulled out of the alliance and communicated to the FCC that the C-Band Alliance was dead. Among other claims, Intelsat argued that it was obvious that the FCC was already treating each satellite operator individually and that it therefore made business sense for each company to respond to the FCC from its own commercial perspective.
One of the major members of the C-Band Alliance, Intelsat, filed for bankruptcy on 14 May 2020, just before the new 5G spectrum auctions were to take place, with over in total debt. Public information showed that the company had been considering bankruptcy protection from at least as early as February 2020.
Differences in frequency range by geographic area
Slight variations in the assignments of C-band frequencies have been approved for use in various parts of the world, depending on their locations in the three ITU radio regions. Note that one region includes all of Europe and Africa, plus all of Russia; a second includes all of the Americas, and the third region includes all of Asia outside of Russia, plus Australia and New Zealand. This latter region is the most populous one, since it includes China, India, Pakistan, Japan, and Southeast Asia.
Amateur radio
The Radio Regulations of the International Telecommunication Union allow amateur radio operations in the frequency range 5.650 to 5.925 GHz, and amateur satellite operations are allowed in the ranges 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links. This is known as the 5-centimeter band by amateurs and the C band by AMSAT.
Particle accelerators
Particle accelerators may be powered by C-band RF sources. The frequencies are then standardized at 5.996 GHz (Europe) or 5.712 GHz (US), which is the second harmonic of S band.
Nuclear fusion experiments
Several tokamak fusion reactors use high-power C-band RF sources to sustain the toroidal plasma current. Common frequencies include 3.7 GHz (Joint European Torus, WEST (formerly Tore Supra)), 4.6 GHz (Alcator C, Alcator C-Mod, EAST, DIII-D), 5 GHz (KSTAR, ITER) and 8 GHz (Frascati Tokamak Upgrade).
Aeronautical radionavigation service
The band 4.2–4.4 GHz is currently allocated to the aeronautical radionavigation service (ARNS) on a primary worldwide basis. RR No. 5.438 notes specifically that this band is reserved exclusively for radar altimeter installed on board aircraft and for the associated transponders on the ground.
Cellular telephony
In February 2020, the U.S. Federal Communications Commission adopted rules for the C band at 3.7–4.2 GHz that allocated the lower 280 megahertz of the band, at 3.7–3.98 GHz, for terrestrial wireless use. Existing satellite operators will have to repack their operations into the upper 200 megahertz of the band, from 4.0 to 4.2 GHz, and there is a 20-megahertz guard band at 3.98–4.0 GHz.
Licenses to use the 3.7–3.98 GHz band were auctioned in December 2020. Verizon, AT&T and T-Mobile are main winners of the auction. Verizon, AT&T, and T-Mobile spent approximately $45 billion, $23 billion, and $9 billion respectively during the auction.
In December 2021, Boeing and Airbus called on the US government to delay the rollout of new 5G phone service that uses C band due to concern of the interference with some sensitive aircraft instruments, especially radio altimeters operating at 4.2–4.4 GHz. On January 18, 2022, Verizon and AT&T announced that they would delay their C-band 5G rollout near airports in response to those concerns.
References
External links
The VSAT Installation Manual Video Presentation shows examples of the arrangement of the Feed for c-band polarization requirements
VSAT Installation Manual with explanation of c-band polarization requirements for a VSAT
Microwave bands
Satellite broadcasting | C band (IEEE) | [
"Engineering"
] | 1,930 | [
"Telecommunications engineering",
"Satellite broadcasting"
] |
51,967,771 | https://en.wikipedia.org/wiki/Norhydrocodone | Norhydrocodone is the major metabolite of the opioid analgesic hydrocodone. It is formed from hydrocodone in the liver via N-demethylation predominantly by CYP3A4. Unlike hydromorphone, a minor metabolite of hydrocodone, norhydrocodone is described as inactive. However, norhydrocodone is actually an agonist of the μ-opioid receptor with similar potency to hydrocodone, but has been found to produce only minimal analgesia when administered peripherally to animals. This is likely due to poor blood-brain-barrier and thus central nervous system penetration.
See also
Norbuprenorphine
Norbuprenorphine-3-glucuronide
Normorphine
Noroxymorphone
References
4,5-Epoxymorphinans
Ketones
Opioid metabolites | Norhydrocodone | [
"Chemistry"
] | 196 | [
"Ketones",
"Functional groups"
] |
51,967,958 | https://en.wikipedia.org/wiki/Noroxycodone | Noroxycodone is the major metabolite of the opioid analgesic oxycodone. It is formed from oxycodone in the liver via N-demethylation predominantly by CYP3A4. Noroxycodone binds to and activates the μ-opioid receptor (MOR) similarly to oxycodone, although with one-third of the affinity of oxycodone and 5- to 10-fold lower activational potency. However, although a potent MOR agonist, noroxycodone poorly crosses the blood-brain-barrier into the central nervous system, and for this reason, is only minimally analgesic in comparison.
See also
Norbuprenorphine
Norbuprenorphine-3-glucuronide
Norhydrocodone
Normorphine
Noroxymorphone
References
4,5-Epoxymorphinans
Ketones
Opioid metabolites | Noroxycodone | [
"Chemistry"
] | 209 | [
"Ketones",
"Functional groups"
] |
51,967,982 | https://en.wikipedia.org/wiki/Paleostress%20inversion | Paleostress inversion refers to the determination of paleostress history from evidence found in rocks, based on the principle that past tectonic stress should have left traces in the rocks. Such relationships have been discovered from field studies for years: qualitative and quantitative analyses of deformation structures are useful for understanding the distribution and transformation of paleostress fields controlled by sequential tectonic events. Deformation ranges from microscopic to regional scale, and from brittle to ductile behaviour, depending on the rheology of the rock, orientation and magnitude of the stress, etc. Therefore, detailed observations in outcrops, as well as in thin sections, are important in reconstructing the paleostress trajectories.
Inversions require assumptions in order to simplify the complex geological processes. The stress field is assumed to be spatially uniform for a faulted rock mass and temporally stable over the concerned period of time when faulting occurred in that region. In other words, the effect of local fault slip is ignored in the variation in small-scale stress field. Moreover, the maximum shear stress resolved on the fault surface from the known stress field and the slip on each of the fault surface has the same direction and magnitude. Since the first introduction of the methods by Wallace and Bott in the 1950s, similar assumptions have been used throughout the decades.
Fault slip analysis
Conjugate fault system
Anderson was the first to utilize conjugate fault systems in interpreting paleostress, including all kinds of conjugate faults (normal, reverse and strike-slip). Regional conjugate fault can be better understood by comparison to a familiar rock mechanics experiment, i.e. the Uniaxial Compressive Strength (UCS) Test. Basics of their mechanisms are similar except the principal stress orientation applied is rotated from perpendicular to parallel to the ground. The conjugate fault model is a simple way to obtain approximate orientations of stress axes, due to the abundance of such structure in the upper brittle crust. Therefore, a number of studies have been carried out by other researchers in assorted structural settings and by correlating with other deformation structures.
Nonetheless, further development revealed the deficiency of the model:
1. Important geometrical properties absent in practical situation
The geometrical properties of conjugate faults are indicative of the sense of stress, but they may not appear in the actual fault patterns.
Slickenside lineations normal to fault plane intersection
Symmetrical sense of motion that gives the obtuse angle in the direction of lengthening
Relation between the intersecting angle of fault planes and mechanical properties, with reference to information from rock mechanics experiments in lab
2. Observed fault patterns are far more sophisticated
There are often oblique pre-existing faults, planes of weaknesses or striations to the fault slip, which do not belong to the conjugate fault sets. Neglecting this considerable amount of data would cause error in analysis.
3. Neglecting the stress ratio (Φ)
This ratio provides the relative magnitude of the intermediate stress (σ2) and thus determines the shape of the stress ellipsoid. However, this model does not give an account on the ratio, save for some specific cases.
Reduced stress tensor
This method was established by Bott in 1959, based on the assumption that direction and sense of slip occurs on the fault plane are the same with those of the maximum resolved shear stress, hence, with known orientations and senses of movements on abundant faults, a particular solution T (the reduce stress tensor) is attained. It gives more comprehensive and accurate results in reconstructing paleostress axes and determining the stress ratio (Φ) than the conjugate fault system. The tensor works by solving for four independent unknowns (three principal axes and Φ) through mathematical computation of observations of faults (i.e. attitude of faults and lineations on fault planes, direction and sense of slip, and other tension fractures).
This method follows four rigorous steps:
Data Analysis
Computation of Reduced Stress Tensor
Minimization
Check of Results
Data analysis
Reconstruction of paleostress requires large amount of data to attain accuracy, so it is essential to organize the data in comprehensible format prior to any analysis.
1) Fault Population Geometry
Attitude of fault planes and slickensides is plotted on rose diagrams, such that the geometry is visible. This is particularly useful when the sample size is enormous, it provides the full picture of the region of interest.
2) Fault Motion
Fault movement is resolved into three components (as in 3D), which are vertical transverse, horizontal transverse and lateral components, by trigonometric relation with the measured dips and trends. Net slip is shown more clearly which paves the way to understanding the deformation.
3) Individual Fault Geometry
Fault planes are represented by lines in stereonets (equal area lower hemisphere projection), while rakes on them are indicated by dots sitting on the lines. It helps to visualize the geometrical distribution and possible symmetry among individual faults.
4) P (pressure) and T (tension) Dihedra
This is a concluding step of compiling all the data and check their mechanical compatibility, also could be seen a preliminary step in determining major paleostress orientations. As this is a simple graphical representation of the fault geometry (being the boundaries of dihedra) and sense of slip (shortening direction indicated by black and extension depicted by grey), while it is able to provide good constraints on the orientation of principal stress axes.
The approximation is built upon the assumption that the orientation of maximum principal stress (σ1) most probably passes through the greatest number of P-quadrants. Since fault plane and auxiliary plane perpendicular to striations are considered the same in this method, the model can be directly applied to focal mechanisms of earthquakes. Nonetheless, due to the same reason, this method cannot provide accurate determination of paleostress, as well as the stress ratio.
Determination of paleostress
Reduced stress tensor
Stress tensor can be considered as a matrix with nine components being the nine stress vectors acting on a point, in which the three vectors along the diagonal (highlighted in brown) represent the principal axes.
The reduced stress tensor is a mathematical computation approach to determining the three principal axes and the stress ratio, totally four independent unknowns, calculated as eigenvectors and eigenvalue respectively, so that this method is more complete and accurate than the mentioned graphical approaches.
There are a number formulations that can reach the same final results but with distinctive features:
(1) ,
where , such that . This tensor is defined by setting σ1, σ2 and σ3 as 1, Φ and 0 (highlighted in pink) respectively, due to choosing and as the mode of reduction. The advantage of this formulation is the direct correspondence to stress orientation, thus the stress ellipsoid, and the stress ratio.
(2)
This formulation is a deviator, which requires more computation to obtain information of the stress ellipsoid despite maintaining a symmetry in mathematical context.
Minimization
Minimization aims to reduce the differences between the computed and observed slip directions of fault planes by choosing a function to proceed the least square minimization. Here are a few examples of the functions:
(1)
The very first function used in fault slip analysis does not account on the sense of individual slip, which means altering the sense of a single slip does not affect the result. However, individual sense of motion is an effective reflection of orientation of stress axes in real situation. Hence, S1 is the simplest function but include the importance of sense of individual slip.
(2)
S2 is derived from S1 based on variation in computational process.
(3)
S3 is an improved version of the previous model in two aspects. Regarding the efficiency in computation, which is particularly significant in long iterative processes like this, tangent of angles is preferred to cosine. Moreover, to deal with anomalous data (e.g. faults initiated by another event, error in data collection etc.), an upper limit of the value of the functions of angle could be set to filter deviated data.
(4)
S4 resembles S2 except the unit vector parallel to shear stress is substituted by the predicted shear stress. Therefore, it still produces similar results as other methods, although its physical meaning is less well justified.
Checking results
The reduced stress tensor should best (hardly perfectly) describe the observed orientations and senses of movement on diversified fault planes in a rock mass. Therefore, by reviewing the fundamental principle of interpreting paleostress from the reduced stress tensor, an assumption is recognized: every fault slip in the rock mass is induced homogeneously by a common stress tensor. This implies the variation in stress orientation and ratio Φ within a rock mass is overlooked yet always present in practical case, due to interaction between discontinuities at any scale.
Hence, the significance of this effect has to be examined to test the validity of the method, by considering the parameter: the difference between the measured slickenside lineation and the theoretical shear stress. The average angular deviation is insignificant when compared with the total of instrumental (measuring tools) and observation (unevenness of fault surfaces and striae) errors in majority of the cases.
In conclusion, the reduced stress tensor method is validated when
sample size is large and representative (homogeneous data sets with a range of fault orientations),
sense of motion of is noted,
minimization of angular difference is emphasized when choosing functions (mentioned in section above), and
rigorous computation takes place.
Limitation
Quantitative analyses cannot stand alone without careful qualitative field observations. The above described analyses are to be carried out after the overall geologic framework is understood e.g. number of paleostress systems, chronological order of successive stress patterns. Also, consistency with other stress markers e.g. stylolites and tension fractures, is required to justify the result.
Examples of application
Cambrian Eriboll Formation sandstones west of the Moine Thrust Zone, NW Scotland
Baikal region, Central Asia
Alpine foreland, Central Northern Switzerland
Grain boundary piezometer
A piezometer is an instrument used in the measurement of pressure (non-directional) or stress (directional) from strain in rocks at any scale. Referring to the paleostress inversion principle, rock masses under stress should exhibit strain at both macroscopic and microscopic scale, while the latter is found at the grain boundaries (interface between crystal grains at the magnitude below 102μm). Strain is revealed from the change in grain size, orientation of grains or migration of crystal defects, through a number of mechanisms e.g. dynamic recrystallization (DRX).
Since these mechanisms primarily depend on flow stress and their resulted deformation is stable, the strained grain size or grain boundary are often used as an indicator of paleostress in tectonically active regions such as crustal shear zones, orogenic belts and the upper mantle.
Dynamic recrystallization (DRX)
Dynamic recrystallization is one of the crucial mechanisms in reducing grain size in shear setting. DRX is defined as a nucleation-and-growth process because
local grain boundary bulging (BLG)(mechanisms of nucleation)
subgrain rotation (SGR)(mechanisms of nucleation)
grain boundary migration (GBM)(mechanisms of grain growth),
are all present in the deformation. This evidence is commonly found in quartz, a typical piezometer, from ductile shear zones. Optical microscope and transmission electron microscope (TEM) are usually utilized in observing the sequential occurrence of subgrain rotation and local grain boundary bulging, and measuring recrystallized grain size. The nucleation process is triggered at boundaries of existing grains only when materials have been deformed to particular critical values.
Grain boundary bulging (BLG)
Grain boundary bulging is the process involving the growth of nuclei at the expense of existing grains and then formation of a 'necklace' structure.
Subgrain rotation (SGR)
Subgrain rotation is also known as in-situ recrystallization without considerable grain growth. This process happens steadily over the strain history, thus the change in orientation is progressive but not abrupt as grain boundary bulging.
Therefore, grain boundary bulging and subgrain rotation are differentiated as discontinuous and continuous dynamic recrystallization respectively.
Theoretical models
Static energy-balance model
The theoretical basis of grain size piezometry was first established by Robert J. Twiss in late 1970s. By comparing free dislocation energy and grain boundary energy, he derived a static energy balance model applicable to subgrain size . Such relation has been represented by an empirical equation between normalized value of grain size and flow stress, which is universal for various materials:
,
d is the average grain size;
b is the length of the Burgers vector;
K is a non-dimensional temperature-dependent constant, which is typically in the order of 10;
μ is the shear modulus;
σ is the flow stress.
This model does not account for the persistently transforming nature of microstructures seen in dynamic recrystallization, so its inability in determination of recrystallized grain size has led to the latter models.
Nucleation-and-growth models
Unlike the previous model, these models consider the sizes of individual grains vary temporally and spatially, therefore, they derive an average grain size from an equilibrium between nucleation and grain growth. The scaling relation of the grain size is as follows:
,
where d is the mode of logarithmic grain size, I is the nucleation rate per unit volume, and a is a scaling factor.
Upon this basic theory, there are still plenty of arguments on the details, which are reflected in the assumptions of the models, so there are various modifications.
Derby–Ashby model
Derby and Ashby considered boundary bulging nucleation at grain boundary in determining the nucleation rate (Igb), which opposes to the intracrystalline nucleation suggested by the prior model. Thus this model describes the microstructures of discontinuous DRX (DDRX):
.
Shimizu model
Because of a contrasting assumption that subgrain rotation nucleation in continuous DRX (CDRX) should be considered for the nucleation rate, Shimizu has come up with another model, which has also been tested in laboratory:
.
Simultaneous operation of dislocation and diffusion creeps
Field boundary model
In the above models, one of the vital factors, especially when the grain size is reduced substantially through dynamic recrystallization, is neglected. The surface energy becomes more significant when grains are sufficiently small, which converts the creep mechanism from dislocation creep to diffusion creep, thus the grains start to grow. Therefore, the determination of the boundary zone between fields of these two creep mechanisms matter to know when the recrystallized grain size tends to stabilize, as to supplement the above model. The difference between this model and the previous nucleation-and-growth models lies within the assumptions: the field boundary model assumes that grain size reduces in the dislocation creep field, and enlarges in the diffusion creep field, but it is not the case in the previous models.
Common piezometers
Quartz is abundant in the crust and contains creep microstructures that are sensitive to deformation conditions in deeper crust. Before starting to infer flow stress magnitude, the mineral has to be calibrated carefully in laboratory. Quartz has been found to exhibit different piezometer relations during different recrystallization mechanisms, which are local grain boundary migration (dislocation creep), subgrain rotation (SGR) and the combination of these two, as well as at different grain size.
Other common minerals used for grain size piezometers are calcite and halite, that have gone through syn-tectonic deformation or manual high-temperature creep, which also demonstrate difference in piezometer relation for distinct recrystallization mechanisms.
References
Further reading
Angelier, J., 1994, Fault slip analysis and paleostress reconstruction. In: Hancock, P.L. (ed.), Continental Deformation. Pergamon, Oxford, p. 101–120.
Célérier, B., Etchecopar, A., Bergerat, F., Vergely, P., Arthaud, F., Laurent, P., 2012. Inferring stress from faulting: From early concepts to inverse methods. Tectonophysics, Crustal Stresses, Fractures, and Fault Zones: The Legacy of Jacques Angelier 581, 206–219.
Pascal, C., 2021. Paleostress Inversion Techniques: Methods and Applications for Tectonics, Elsevier, 400 p. https://www.elsevier.com/books/paleostress-inversion-techniques/pascal/978-0-12-811910-5
Ramsay, J.G., Lisle, R.J., 2000. The Techniques of Modern Structural Geology. Volume 3: Applications of continuum mechanics in structural geology (Session 32: Fault Slip Analysis and Stress Tensor Calculations), Academic Press, London.
Yamaji, A., 2007. An Introduction to Tectonophysics: Theoretical Aspects of Structural Geology (Chapter 11: Determination of Stress from Faults), Terrapub, Tokyo. http://www.terrapub.co.jp/e-library/yamaji/
Structural geology
Deformation (mechanics) | Paleostress inversion | [
"Materials_science",
"Engineering"
] | 3,570 | [
"Deformation (mechanics)",
"Materials science"
] |
51,970,331 | https://en.wikipedia.org/wiki/D%20band%20%28waveguide%29 | The waveguide D band is the range of radio frequencies from 110 GHz to 170 GHz in the electromagnetic spectrum, corresponding to the recommended frequency band of operation of the WR6 and WR7 waveguides. These frequencies are equivalent to wavelengths between 2.7 mm and 1.8 mm. The D band is in the EHF range of the radio spectrum.
References
Radio spectrum | D band (waveguide) | [
"Physics"
] | 77 | [
"Radio spectrum",
"Spectrum (physical sciences)",
"Electromagnetic spectrum"
] |
51,973,048 | https://en.wikipedia.org/wiki/PSR%20J0337%2B1715 | PSR J0337+1715 is a millisecond pulsar discovered in a Green Bank Telescope drift-scan survey from 2007. It is spinning nearly 366 times per second, 4200 light years away in the constellation Taurus. It is the first pulsar found in a stellar triple system. It is co-orbiting very closely with another star, a 0.2 solar-mass white dwarf, with a period of 1.6 days. There is a second white dwarf further out (within one astronomical unit) which is orbiting both the pulsar and the inner white dwarf, and has an orbit with a period of 327 days and a mass of 0.4 solar masses. The fact that the pulsar is part of a triple system provides an opportunity to test the nature of gravity and the strong equivalence principle, with a sensitivity several orders of magnitude greater than before.
Results were published in 2018 showing that if there is any departure from the equivalence principle it is no more than three parts per million at 95% confidence level, improved to two parts per million in 2020.
Planetary system
In 2022 evidence for a small planet with a mass comparable to that of the Moon on a wide orbit was found. In 2024, a study refined our knowledge of the planet's physical and orbital properties, finding that its mass is approximately , or about 30% that of the Moon, making it one of the least massive known objects outside the solar system. Its orbital parameters have been more thoroughly established, showing that it is on a slightly eccentric orbit lasting 3,310 days (or just over 9 years) which is also severely inclined relative to the plane of the triple system's orbit, suggesting it may have arrived there via influence from a Kozai mechanism.
Since PSR J0337+1715 (AB) b's orbit is relatively stable (for at least 100 million years), it may possibly be the last surviving member of a population of small objects which were formed after the progenitor of the pulsar in this system became a red supergiant, engulfing one of the two other stars and creating a common envelope between it and said star. The engulfed star was slowed down from the common envelope gas, transferring its orbital energy to that gas, causing it to expand and be expelled from the star, settling into a circumbinary disk where many small objects condensed from this gas. Of those, only PSR J0337+1715 (AB) b is still present, as all the others were on less stable orbits which likely got them ejected from the system or crashing into one of the stars.
References
01
Taurus (constellation)
Astronomical objects discovered in 2014
Triple star systems
Pulsars
White dwarfs
Astronomical objects discovered in 2022 | PSR J0337+1715 | [
"Astronomy"
] | 565 | [
"Taurus (constellation)",
"Constellations"
] |
51,974,242 | https://en.wikipedia.org/wiki/Drama%20annotation | Drama annotation is the process of annotating the metadata of a drama. Given a drama expressed in some medium (text, video, audio, etc.), the process of metadata annotation identifies what are the elements that characterize the drama and annotates such elements in some metadata format. For example, in the sentence "Laertes and Polonius warn Ophelia to stay away from Hamlet." from the text Hamlet, the word "Laertes", which refers to a drama element, namely a character, will be annotated as "Char", taken from some set of metadata. This article addresses the drama annotation projects, with the sets of metadata and annotations proposed in the scientific literature, based markup languages and ontologies.
Drama across media and genres
Drama encompasses different media and languages, ranging from Greek tragedy and musical drama to action movies and video games: despite their huge differences, these examples share traits of the cultural construct that we recognise as drama. drama can be considered as a form of intangible cultural heritage, since it is characterised by an evolving nature, with form and function that change in time: for example, consider the difference between the Greek tragedy Oedipus and the modernist play Six Characters in Search of an Author. The exponential spread of drama in contemporary culture has led Martin Esslin to forge the definition of “dramatic media", i.e. media that display characters performing live actions, such as theatre, cinema and videogames.
The discrete manifestations of drama are documented in different media, including text, score, video, audio, etc. The dramatic content underlying these manifestation, however, does not depend on the specific medium: take, for example, the Arden edition of the written drama of Hamlet and Laurence Olivier's movie Hamlet, two examples of the drama heritage which share the same drama content despite the differences of the media support. The annotation of the content of media that convey dramatic content requires the use of an annotation schema expressed in a formal language, which makes the annotation comparable, and, possibly, machine readable.
The first attempts at attaching content metadata to media concerned text documents and were carried out by using markup languages, such as XML, which allow embedding content tags into the document text. With the advent of the Semantic Web project, descriptive tools have evolved towards the use of ontologies, thanks to the languages and resources provided by the Semantic Web project. In particular, semantic annotation relies on the use of the Resource Description Framework language, specifically designed to described Web content of any type.
The semantic annotation of drama consists of representing the knowledge about drama in a machine-readable format to serve the task of annotating the dramatic content coherently across different media and languages, abstracting at the same time from the technicalities of signals and text encoding. The annotation of dramatic content across media and genres is a way to preserve, compare and study the nature of drama and of its manifestations. Moreover, the availability of content metadata about drama is a precondition for a range of generative tasks that range from automatising the generation of drama to supporting human creativity in this task.
Story and Drama Annotation through markup languages and linguistic schemata
Story annotation consists of annotating the content of narratives. In most cases, this effort is undertaken with the goal of constructing corpora of annotated narratives, or story corpora, finalised at the study of the relationship between the linguistic expression of the story in the narrative and its content.
In the last decade, to a number of research initiatives especially oriented to the description of story and characters. For example, consider the Narrative Knowledge Representation Language (NKRL) and the DramaBank project, specifically oriented to the representation of story content in natural language texts.
The annotation of narrative texts has been prompted and influenced by two main lines of research. On the one side, the tradition of knowledge representation in AI has contributed the conceptual tools for describing the content of stories, with languages that span from scripts [Schank 1975] to frames.
The linguistic counterpart of this line of research has resulted in resources situated at the lexical-semantic level (such as FrameNet and at the interface between syntax and semantics (such as PropBank, which offer tools for representing the connection between the expression of the narrative through the text and the narrative content itself). For example, the Story Workbench tool encompasses a layered annotation scheme, which uses these resources for the multi-layer annotation of narratives. On the other side, the annotation of narratives has benefited from the trend, established during the last three decades, of representing the content of documents in a machine-readable form. With the advent of markup languages such as Text Encoding Initiative (TEI) for encoding text in digital form and annotating their structure, the use of markup has soon become the standard in text annotation projects.
In particular, projects such as Narrative Knowledge Representation Language (NKRL) leveraged the use of markup languages for the representation of the narrative content of text, revamping the use of frames into the emerging scenario of media indexing and retrieval. More recently, as part of the more general effort of constructing resources for the automation of language processing and generation, Elson has proposed a template based language for describing the narrative content of text documents, with the goal of creating a corpus of annotated narrative texts, called DramaBank project. In recent years, the annotation of narrative text has evolved towards minimal schemata targeted at grasping the regularities of written and oral narratives at the discourse level. These initiatives, however, rooted in narrative theories, tend to focus on the realization of narratives though a specific medium, i.e., text, leaving behind the universal elements of dramatic narration that go behind the expressive characteristics of each medium.
Story and drama annotation through computational ontologies
Mostly oriented to the indexing and retrieval of media, ontologies, and vocabularies have appeared that support the representation of the content of media according to a shared semantics, available across the Web. In particular, semantic resources such as VERL (the Video Event Representation Language and LODE (Linked Open Description of Events) provide structured description of events that can be applied to the description of incidents in stories. In the paradigm of Linked Data, these resources become the infrastructure for content-based applications in the field of media: for example, consider the project EventMedia, where different vocabularies have been aligned with automatic methods to create an illustrated catalog of media representing events.
A media-independent model of story is provided by the OntoMedia ontology, exploited across different projects (such as the Contextus Project to annotate the narrative content of different media objects, ranging from written literature to comics and TV fiction. This project encompasses some concepts, such the notion of character, that are relevant for the description of drama, but, being mainly focused on the representation of events and the order in which they are exposed in media for cross-media comparison, it lacks the capability of representing the core notions of drama. In the field of cultural heritage dissemination, the StorySpace ontology, an ontology of story, supports museum curators in linking the content of artworks through stories, with the ultimate goal of enabling the generation of user tailored content retrieval.
A line of research has tackled the use of logical representations to describe stories, with the goal of creating generative systems that leverage the axiomatization of narrative structures. Finally, some scholars have created representational tools for specific narrative theories, ranging from literary structuralism to scriptwriting practices
References
External links
Story Workbench tool
Contextus Project
Drammar project wiki
Metadata | Drama annotation | [
"Technology"
] | 1,595 | [
"Metadata",
"Data"
] |
51,975,023 | https://en.wikipedia.org/wiki/Mailvelope | Mailvelope is free software for end-to-end encryption of email traffic inside of a web browser (Firefox, Chromium or Edge) that integrates itself into existing webmail applications ("email websites"). It can be used to encrypt and sign electronic messages, including attached files, without the use of a separate, native email client (like Thunderbird) using the OpenPGP standard.
The name is a portmanteau of the words "mail" and "envelope". It is published together with its source code under the terms of version 3 of the GNU Affero General Public License (AGPL). The company Mailvelope GmbH runs the development using a public code repository on GitHub. Development is sponsored by the Open Technology Fund and Internews.
Similar alternatives had been Mymail-Crypt and WebPG.
Features
Mailvelope equips webmail applications with OpenPGP functionality. Support for several popular providers like Gmail, Yahoo, Outlook on the web and others are preconfigured.
The webmail software Roundcube senses and supports Mailvelope as of version 1.2 from May 2016, as well as most (self-hosted) webmail clients. For Chromium/Chrome there's the possibility to install from an authenticated source using the integrated software extension manager "Chrome Web Store". In addition, Mailvelope is also available for Firefox and Microsoft Edge as an add-on.
Mailvelope works according to the OpenPGP standard, a public-key cryptosystem first standardized in 1998 and is written in JavaScript. On preset or user-authorized web pages it overlays the page with its control elements, which are optically distinguished as being separate from the web application by a surrounding security-background. This background can be customized to detect impersonations. For encryption it relies on the functionality of the program library OpenPGP.js, a free JavaScript Implementation of the OpenPGP standard. By running inside a separate inline frame, its code is executed separately from the web application and should prevent it from accessing clear text message contents.
The integration of Mailvelope via an API, developed in collaboration with United Internet, allows deeper integration between the webmail service and Mailvelope components. Thus, the setup and generation of a key pair can be done directly in the webmailer using a wizard. Mailvelope manages all OpenPGP keys locally in the browser. Since version 3.0, a local GnuPG installation can be included in Mailvelope's key management, allowing users to use native applications if desired.
History and usage
Thomas Oberndörfer started developing Mailvelope in spring 2012 with the first public version 0.4.0.1 released on August 24. The global surveillance disclosure raised questions about the security of private and business email communication. At the time, e-mail encryption with OpenPGP was considered too complicated to use. Moreover, the webmail services that were particularly popular with private individuals did not offer any end-to-end encryption functions. This led to various mentions of Mailvelope in the press as a possible solution to this problem.
Mario Heiderich and Krzysztof Kotowicz of Cure53 did a security audit on an alpha version from 2012/2013. Among other things, the separation from the web application and its data structures was improved based on its findings. In February 2014, the same group analysed the library OpenPGP.js which Mailvelope is based on. Version 0.8.0, released the following April, adopted the resulting fixes and added support for message signing. In May 2014, iSEC Partners published an analysis of the Firefox extension. Version 1.0.0 was published on August 18, 2015.
In April 2015, De-Mail providers equipped their services with a default disabled option for end-to-end encryption based on Mailvelope, but it could only be used in combination with Mobile TAN or the German electronic identity card. The new version of the extension was released in May 2015.
In August 2015, the email services of Web.de and GMX introduced support for OpenPGP encryption and integrated Mailvelope into their webmail applications for that. According to the company's own information, this option to encrypt e-mails in this way was available to around 30 million users.
A 2015 study examined the usability of Mailvelope as an example of a modern OpenPGP client and deemed it unsuitable for the masses. They recommended integrating assistant functionality, sending instructive invitation messages to new communication partners, and publishing basic explanatory texts. The Mailvelope-based OpenPGP system of United Internet integrates such functionality and its usability earned some positive mentions in the press, particularly the offered key synchronization feature. A usability analysis from 2016 found it to still be "worthy of improvement" ("verbesserungswürdig"), though, and mentioned "confusing wording" ("irritierende Formulierungen"), missing communication of the concept, bad password recommendations, missing negative dissociation of the more prominent modus that features only transport encryption, plus insufficient support for key authenticity checking (to thwart man-in-the-middle attacks).
Mailvelope was enhanced in 2018/19 as part of a BSI initiative. Overall, the "key management was simplified, and security of the software improved." All security vulnerabilities in the Mailvelope source code, as well as in the OpenPGP.js program library used, brought to light by a security audit conducted by SEC Consult were closed. According to the BSI, one goal of the project was also to enable website operators to offer contact forms in the future to securely encrypt messages from the user's browser to the recipient. The import of new keys would be HTTPS-encrypted using the WKD (Web Key Directory) protocol.
References
External links
Software add-ons
Cryptographic software
Free software programmed in JavaScript
Free Firefox WebExtensions | Mailvelope | [
"Mathematics"
] | 1,278 | [
"Cryptographic software",
"Mathematical software"
] |
51,975,796 | https://en.wikipedia.org/wiki/New%20England%20water%20resource%20region | The New England water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers.
The New England region, which is listed with a 2-digit hydrologic unit code (HUC) of 01, has an approximate size of , and consists of 11 sub-regions, which are listed with the 4-digit HUCs 0101 through 0111.
This region includes the drainage within the United States that ultimately discharges into: (a) the Bay of Fundy; (b) the Atlantic Ocean within and between the states of Maine and Connecticut; (c) Long Island Sound north of the New York-Connecticut state line; and (d) the Riviere St. Francois, a tributary of the Saint Lawrence River. The region includes all of Maine, New Hampshire and Rhode Island, and parts of Connecticut, Massachusetts, New York, and Vermont.
List of water resource subregions
See also
List of rivers of the United States
Water resource region
References
External links
Lists of drainage basins
Drainage basins
Watersheds of the United States
Regions of the United States
Resource
Water resource regions | New England water resource region | [
"Environmental_science"
] | 270 | [
"Hydrology",
"Drainage basins"
] |
64,584,571 | https://en.wikipedia.org/wiki/Dinickel%20boride | Dinickel boride is a chemical compound of nickel and boron with formula . It is one of the borides of nickel.
The formula "" and the name "nickel boride" are often used for a nickel-boron catalyst obtained by reacting nickel salts with sodium borohydride. However, that product is not a well-defined compound, and its bulk formula is closer to (sic).
Synthesis
Dinickel boride can be obtained (together with other nickel borides) by heating sodium borohydride with powdered nickel metal up to 670 °C in a closed vessel, so that the released hydrogen creates a pressure of up to 3.4 MPa. The main reactions can be summarized as
2 ↔ 2NaH +
2Ni + 2 + NaH ↔ + 3 + 2 + Na
but other reactions occur, yielding other borides.
See also
Trinickel boride
References
Borides
Nickel compounds | Dinickel boride | [
"Chemistry"
] | 194 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
64,585,819 | https://en.wikipedia.org/wiki/Insulin%20degludec/insulin%20aspart | Insulin degludec/insulin aspart, sold under the brand name Ryzodeg, is a fixed-dose combination medication for the treatment of diabetes mellitus. It contains insulin degludec and insulin aspart. It is given as an injection under the skin in the abdominal wall (at the front of the waist), upper arm or thigh.
The most frequently reported side effect is hypoglycemia (low blood glucose levels).
It was approved for medical use in the European Union in January 2013, and in Australia in November 2017.
Medical uses
Insulin degludec/insulin aspart is indicated for the treatment of diabetes mellitus in adults, adolescents and children from the age of two years.
Insulin degludec and insulin aspart are slightly different from human insulin. The differences mean that insulin degludec is absorbed more slowly by the body. This means it has a long duration of action. Meanwhile, insulin aspart is absorbed faster by the body than human insulin, and therefore it starts to work as soon as it is injected and has a short duration of action.
References
Human proteins
Insulin receptor agonists
Peptide hormones
Peptide therapeutics
Recombinant proteins | Insulin degludec/insulin aspart | [
"Biology"
] | 253 | [
"Recombinant proteins",
"Biotechnology products"
] |
64,586,299 | https://en.wikipedia.org/wiki/Assault%20Engineering%20Brigades | Assault Engineering Brigades () or Storm Engineer-Sapper Brigades were formations of the Reserve of the Supreme High Command of the Red Army, being notable for their service during the Second World War. These brigades were designed to storm settlements and to break through heavily fortified enemy lines. These units are commonly abbreviated as ShISBr (), and are occasionally referred to as "armoured infantry" or "cuirass infantry" ().
History
Sapper-engineering assault units were formed in 1943. By 30 May of that year, the formation of the first 15 brigades was completed. Most of these units were formed from existing combat battalions, well-proven in battle. In August 1943, assault engineer-sapper brigades arrived at the front. These were each composed of:
Brigade Command (40 people)
Command Company (87 people)
Motorized Engineer-Scout Company (101 people)
5 Assault Engineer-Sapper Battalions (388 people each)
Light Bridging and Crossing Equipment Crew (36 people)
During the formations of assault engineering brigades, all soldiers over 40 years of age were reassigned. The most distinctive piece of individual equipment used by soldiers of the assault engineering brigades was the SN-42 () steel breastplate.
In December 1943, a procedure was developed for the combat utilization of assault formations. Assault brigades were sent into battle to facilitate key breakthroughs in fortified defensive lines by means of combat engineering and sapping. Success in battle hinged on close coordination with infantry, armoured, mechanized, and artillery units. As soldiers of the assault brigades were not equipped with heavy small arms or their own artillery, they were immediately withdrawn after a successful breakthrough in the enemy lines to limit casualties.
In the spring of 1944 the assault engineering brigades were supplied with ROKS-3 flamethrowers. The 1st, 2nd, 4th, 10th, and 2nd Guards assault engineer-sapper brigades were supplemented with engineer-tank regiments including PT-3 () mine flails and OT-34 flamethrower tanks, each composed of three companies with 20 combat vehicles per company.
By May 1945, the brigades pushed through the city of Konigsberg (now Kaliningrad), with the city falling in a matter of days.
Over the course of the Second World War 20 assault engineer-sapper brigades were formed, performing admirably in combat operations, and especially distinguishing themselves in the storming of cities, which was their intended purpose.
Legacy
Combat engineers are one of the branches of the Red Army that are given special reverence. In 2015 and 2020, a formation of soldiers dressed in the uniforms of engineer assault brigades took part in the Moscow Victory Day Parade on Red Square. During a national ceremony at the Capul de pod Șerpeni Memorial Complex in August 2019, Russian Defence Minister Sergey Shoigu ceremonially handed to Moldovan Defence Minister Pavel Voicu the military banners of the 14th Assault Engineering and Combat Brigade, which until that point, was kept at the Central Armed Forces Museum in Russia.
Structure
1st Guards Assault Engineering Sapper Brigade
1st Assault Engineering and Sapper Brigade
2nd Assault Engineering and Combat Engineer Brigade
3rd Assault Engineering and Combat Engineer Brigade
4th Assault Engineering and Sapper Brigade
5th Assault Engineering and Combat Engineer Brigade
6th Assault Engineering and Combat Engineer Brigade
7th Assault Engineering and Sapper Brigade
8th Assault Engineering and Sapper Brigade
9th Assault Engineering and Combat Engineer Brigade
10th Assault Engineering and Combat Engineer Brigade
11th Assault Engineering and Sapper Brigade
12th Assault Engineering and Combat Engineer Brigade
13th Assault Engineering and Combat Engineer Brigade
14th Assault Engineering and Combat Engineer Brigade
15th Assault Engineering and Combat Engineer Brigade
16th Assault Engineering and Combat Engineer Brigade
17th Assault Engineering and Combat Engineer Brigade
18th Assault Engineering and Sapper Brigade
19th Assault Engineering and Sapper Brigade
See also
Sapper army
Pososhniye lyudi
References
Red Army units and formations of World War II
Engineering units and formations | Assault Engineering Brigades | [
"Engineering"
] | 773 | [
"Engineering units and formations",
"Military engineering"
] |
64,586,749 | https://en.wikipedia.org/wiki/Oxford%E2%80%93AstraZeneca%20COVID-19%20vaccine | The Oxford–AstraZeneca COVID19 vaccine, sold under the brand names Covishield and Vaxzevria among others, is a viral vector vaccine for the prevention of COVID-19. It was developed in the United Kingdom by Oxford University and British-Swedish company AstraZeneca, using as a vector the modified chimpanzee adenovirus ChAdOx1. The vaccine is given by intramuscular injection. Studies carried out in 2020 showed that the efficacy of the vaccine is 76.0% at preventing symptomatic COVID-19 beginning at 22 days following the first dose and 81.3% after the second dose. A study in Scotland found that, for symptomatic COVID-19 infection after the second dose, the vaccine is 81% effective against the Alpha variant (lineage B.1.1.7) and 61% against the Delta variant (lineage B.1.617.2).
The vaccine is stable at refrigerator temperatures and has a good safety profile, with side effects including injection-site pain, headache, and nausea, all generally resolving within a few days. More rarely, anaphylaxis may occur; the UK Medicines and Healthcare products Regulatory Agency (MHRA) has 268 reports out of some 21.2million vaccinations . In very rare cases (around 1 in 100,000 people), the vaccine has been associated with an increased risk of blood clots when in combination with low levels of blood platelets (embolic and thrombotic events after COVID-19 vaccination). According to the European Medicines Agency, as of 4 April 2021, a total of 222 cases of blood clots had been recorded among 34 million people who had been vaccinated in the European Economic Area (a percentage of 0.0007%).
On 30 December 2020, the vaccine was first approved for use in the UK vaccination programme, and the first vaccination outside of a trial was administered on 4 January 2021. The vaccine has since been approved by several medicine agencies worldwide, such as the European Medicines Agency (EMA), and the Australian Therapeutic Goods Administration (provisional approval in February 2021), and was approved for an Emergency Use Listing by the World Health Organization (WHO). More than 3billion doses of the vaccine were supplied to countries worldwide. Some countries have limited its use to elderly people at higher risk for severe COVID-19 illness due to concerns over the very rare side effects of the vaccine in younger individuals.
The vaccine is no longer in production. AstraZeneca withdrew its marketing authorizations for the vaccine from the European market in March 2024, and worldwide by May 2024.
Medical uses
The Oxford–AstraZeneca COVID19 vaccine is used to provide protection against infection by the SARS-CoV-2 virus in order to prevent COVID-19 in adults aged 18 years and older. The medicine is administered by two doses given by intramuscular injection into the deltoid muscle (upper arm). The initial course consists of two doses with an interval of 4 to 12 weeks between doses. The World Health Organization (WHO) recommends an interval of 8 to 12 weeks between doses for optimal efficacy.
, there is no evidence that a third booster dose is needed to prevent severe disease in healthy adults.
Effectiveness
Preliminary data from a study in Brazil with 61 million individuals from January to June 2021, indicate that the effectiveness against infection, hospitalization and death is similar between most age groups, but protection against all these outcomes is significantly reduced in those aged 90 year of age or older, attributable to immunosenescence.
A vaccine is generally considered effective if the estimate is ≥50% with a >30% lower limit of the 95% confidence interval. Effectiveness is generally expected to slowly decrease over time.
Preliminary data suggest that the initial two-dose regimen is not effective against symptomatic disease caused by the Omicron variant from the 15th week onwards. A regimen of two doses of the Oxford–AstraZeneca vaccine followed by a booster dose of the Pfizer–BioNTech or the Moderna vaccine is initially about 60% effective against symptomatic disease caused by Omicron, then after 10 weeks the effectiveness drops to about 35% with the Pfizer–BioNTech and to about 45% with the Moderna vaccine. The vaccine remains effective against severe disease, hospitalization and death.
Contraindications
The Oxford–AstraZeneca COVID-19 vaccine should not be administered to people who have had capillary leak syndrome.
Adverse effects
The most common side effects in the clinical trials were usually mild or moderate and got better within a few days after vaccination.
Vomiting, diarrhoea, fever, swelling, redness at the injection site and low levels of blood platelets occurred in less than 1 in 10 people. Enlarged lymph nodes, decreased appetite, dizziness, sleepiness, sweating, abdominal pain, itching and rash occurred in less than 1 in 100 people.
An increased risk of the rare and potentially fatal thrombosis with thrombocytopenia syndrome (TTS) has been associated with mainly younger female recipients of the vaccine. Analysis of VigiBase reported embolic and thrombotic events after vaccination with Oxford–AstraZeneca, Moderna and Pfizer vaccines, found a temporally related incidence of 0.21 cases per 1 million vaccinated-days.
Anaphylaxis and other allergic reactions are known side effects of the Oxford–AstraZeneca COVID-19 vaccine. The European Medicines Agency (EMA) has assessed 41 cases of anaphylaxis from around 5million vaccinations in the United Kingdom.
Capillary leak syndrome is a possible side effect of the vaccine.
The European Medicines Agency (EMA) listed Guillain-Barré syndrome as a very rare side effect of the Oxford–AstraZeneca COVID-19 vaccine and added a warning in the product information.
Additional side effects include tinnitus (persistent ringing in the ears), paraesthesia (unusual feeling in the skin, such as tingling or a crawling sensation), and hypoaesthesia (decreased feeling or sensitivity, especially in the skin).
Pharmacology
The Oxford–AstraZeneca COVID-19 vaccine is a viral vector vaccine containing a modified, replication-deficient chimpanzee adenovirus ChAdOx1, containing the full‐length codon‐optimised coding sequence of SARS-CoV-2 spike protein along with a tissue plasminogen activator (tPA) leader sequence. The adenovirus is called replication-deficient because some of its essential genes required for replication were deleted and replaced by a gene coding for the spike protein. However, the HEK 293 cells used for vaccine manufacturing, express several adenoviral genes, including the ones required for the vector to replicate. Following vaccination, the adenovirus vector enters the cells and releases its genes, in the form of DNA, which are transported to the cell nucleus; thereafter, the cell's machinery does the transcription from DNA into mRNA and the translation into spike protein. The approach to use adenovirus as a vector to deliver spike protein is similar to the approach used by the Johnson & Johnson COVID-19 vaccine and the Russian Sputnik V COVID-19 vaccine.
The protein of interest is the spike protein, a protein on the exterior of the virus that enables SARS-type coronaviruses to enter cells through the ACE2 receptor. Following vaccination, the production of coronavirus spike protein within the body will cause the immune system to attack the spike protein with antibodies and T-cells if the virus later enters the body.
Manufacturing
To manufacture the vaccine the virus is propagated on HEK 293 cell lines and then purified multiple times to completely remove the cell culture.
The vaccine costs around to per dose to manufacture. On 17 December 2020, a tweet by the Belgian Budget State Secretary revealed that the European Union (EU) would pay () per dose, The New York Times suggesting the lower price might relate to factors including investment in vaccine production infrastructure by the EU.
the vaccine active substance (ChAdOx1-SARS-COV-2) was being produced at several sites worldwide, with AstraZeneca claiming to have established 25 sites in 15 countries. The UK sites at that time were Oxford and Keele, with bottling and finishing in Wrexham. Other sites at that time included the Serum Institute of India at Pune. The Halix site at Leiden was approved by the EMA on 26 March 2021, joining three other sites approved by the EU.
History
The vaccine arose from a collaboration between Oxford University's Jenner Institute and Vaccitech, a private company spun off from the university, with financing from Oxford Sciences Innovation, Google Ventures, and Sequoia Capital, among others. The first batch of the COVID-19 vaccine produced for clinical testing was developed by Oxford University's Jenner Institute and the Oxford Vaccine Group in collaboration with Italian manufacturer Advent Srl located in Pomezia. The team is led by Sarah Gilbert, Adrian Hill, Andrew Pollard, Teresa Lambe, Sandy Douglas and Catherine Green.
Early development
In February 2020, the Jenner Institute agreed a collaboration with the Italian company Advent Srl for the production of a batch of 1,000 doses of a vaccine candidate for clinical trials. Originally, Oxford intended to donate the rights to manufacture and market the vaccine to any drugmaker who wanted to do so, but after the Gates Foundation urged Oxford to find a large company partner to get its COVID-19 vaccine to market, the university backed off of this offer in May 2020. The UK government then encouraged Oxford to work with AstraZeneca, a company based in Europe, instead of Merck & Co., a US-based company (The Guardian reported the initial partner was the German-based Merck Group instead). Government ministers also had concerns that a vaccine manufactured in the US would not be available in the UK, according to anonymous sources in The Wall Street Journal. Financial considerations at Oxford and spin-out companies may have also played a part in the decision to partner with AstraZeneca.
An initially not-for-profit licensing agreement was signed between the university and AstraZeneca PLC, in May 2020, with 1billion doses of potential supply secured, with the UK reserving access to the initial 100million doses. Furthermore, the US reserved 300million doses, as well as the authority to perform Phase III trials in the US. The collaboration was also granted of UK government funding, and of US government funding, to support the development of the vaccine. In June 2020, the US National Institute of Allergy and Infectious Diseases (NIAID) confirmed that the third phase of trials for the vaccine would begin in July 2020. On 4 June, AstraZeneca announced that the COVAX program for equitable vaccine access managed by the WHO and financed by CEPI and GAVI had spent $750m to secure 300million doses of the vaccine to be distributed to low-income or under-developed countries.
Preliminary data from a study that reconstructed funding for the vaccine indicates that funding was at least 97% public, almost all from UK government departments, British and American scientific institutes, the European Commission and charities.
Clinical trials
In July 2020, AstraZeneca partnered with IQVIA to accelerate the timeframe for clinical trials being planned or conducted in the US. On 31 August, AstraZeneca announced that it had begun enrolment of adults for a US-funded, 30,000-subject late-stage study.
Clinical trials for the vaccine candidate were halted worldwide on 8 September, as AstraZeneca investigated a possible adverse reaction which occurred in a trial participant in the UK. Trials were resumed on 13 September after AstraZeneca and Oxford, along with UK regulators, concluded it was safe to do so. AstraZeneca was later criticised for refusing to provide details about potentially serious neurological side effects in two trial participants who had received the experimental vaccine in the UK. While the trials resumed in the UK, Brazil, South Africa, Japan and India, the US did not resume clinical trials of the vaccine until 23 October. This was due to a separate investigation by the Food and Drug Administration surrounding a patient illness that triggered a clinical hold, according to the US Department of Health and Human Services (HHS) Secretary Alex Azar.
The results of the COV002 phase II/III trial showed that immunity lasts for at least one year after a single dose.
Results of Phase III trial
On 23 November 2020, the first interim data was released by Oxford University and AstraZeneca from the vaccine's ongoing Phase III trials. The interim data reported a 70% efficacy, based on combined results of 62% and 90% from different groups of participants who were given different dosages. The decision to combine results from two different dosages was met with criticism from some who questioned why the results were being combined. AstraZeneca responded to the criticism by agreeing to carry out a new multi-country trial using the lower dose, which had led to the 90% claim.
The full publication of the interim results from four ongoing Phase III trials on 8 December allowed regulators and scientists to begin evaluating the vaccine's efficacy. The December report showed that at 21 days after the second dose and beyond, there were no hospitalisations or severe disease in those who received the vaccine, compared to 10 cases in the control groups. The rate of serious adverse events was balanced between the active and control groups, which suggested that the active vaccine did not pose safety concerns beyond a rate experienced in the general population. One case of transverse myelitis was reported 14 days after the second-dose was administered as being possibly related to vaccination, with an independent neurological committee considering the most likely diagnosis to be of an idiopathic, short-segment, spinal cord demyelination. The other two cases of transverse myelitis, one in the vaccine group and the other in the control group, were considered to be unrelated to vaccination.
A subsequent analysis, published on 19 February 2021, showed an efficacy of 76.0% at preventing symptomatic COVID-19 beginning at 22 days following the first dose, increasing to 81.3% when the second dose is given 12 weeks or more after the first. However, the results did not show any protection against asymptomatic COVID-19 following only one dose. Beginning 14 days following timely administration of a second dose, with different duration from the first dose depending on trials, the results showed 66.7% efficacy at preventing symptomatic infection, and the UK arm (which evaluated asymptomatic infections in participants) was inconclusive as to the prevention of asymptomatic infection. Efficacy was higher at greater intervals between doses, peaking at around 80% when the second dose was given at 12 weeks or longer after the first. Preliminary results from another study with 120 participants under 55 years of age showed that delaying the second dose by up to 45 weeks increases the resulting immune response and that a booster (third) dose given at least six months later produces a strong immune response. A booster dose may not be necessary, but it alleviates concerns that the body would develop immunity to the vaccine's viral vector, which would reduce the potency of annual inoculations.
On 22 March 2021, AstraZeneca released interim results from the phase III trial conducted in the US that showed efficacy of 79% at preventing symptomatic COVID-19 and 100% efficacy at preventing severe disease and hospitalisation. The next day, the National Institute of Allergy and Infectious Diseases (NIAID) published a statement countering that those results may have relied on "outdated information" that may have provided an incomplete view of the efficacy data. AstraZeneca later revised its efficacy claim to be 76% after further review of the data. On 29 September 2021, AstraZeneca shows of 74% efficacy rate in the US trial.
Single dose effectiveness
A study on the effectiveness of a first dose of the Pfizer–BioNTech or Oxford–AstraZeneca COVID-19 vaccines against COVID-19 related hospitalisation in Scotland was based on a national prospective cohort study of 5.4million people. Between 8 December 2020 and 15 February 2021, 1,137,775 participants were vaccinated in the study, 490,000 of whom were given the Oxford–AstraZeneca vaccine. The first dose of the Oxford–AstraZeneca vaccine was associated with a vaccine effect of 94% for COVID-19-related hospitalisation at 28–34 days post-vaccination. Combined results (all vaccinated participants, whether Pfizer–BioNTech or Oxford–AstraZeneca) showed a significant vaccine effect for prevention of COVID-19-related hospitalisation, which was comparable when restricting the analysis to those aged ≥80 years (81%). The majority of the participants over the age of 65 were given the Oxford–AstraZeneca vaccine.
Nasal spray
On 25 March 2021, the University of Oxford announced the start of a phase I clinical trial to investigate the efficacy of an intranasal spray method.
Approvals
The first country to issue a temporary or emergency approval for the Oxford–AstraZeneca vaccine was the UK. The Medicines and Healthcare products Regulatory Agency (MHRA) began a review of efficacy and safety data on 27 November 2020, followed by approval for use on 30 December 2020, becoming the second vaccine approved for use in the national vaccination programme. The BBC reported that the first person to receive the vaccine outside of clinical trials was vaccinated on 4 January 2021.
The European Medicines Agency (EMA) began review of the vaccine on 12 January 2021, and stated in a press release that a recommendation could be issued by the agency by 29 January, followed by the European Commission deciding on a conditional marketing authorisation within days. On 29 January 2021, the EMA recommended granting a conditional marketing authorisation for AZD1222 for people 18 years of age and older, and the recommendation was accepted by the European Commission the same day. Prior to approval across the EU, the Hungarian regulator unilaterally approved the vaccine instead of waiting for EMA approval. In October 2022, the conditional marketing authorisation was converted to a standard one.
On 30 January 2021, the Vietnamese Ministry of Health approved the AstraZeneca vaccine for use, becoming the first vaccine to be approved in Vietnam. The vaccine has since been approved by a number of non-EU countries, including Argentina, Bangladesh, Brazil, the Dominican Republic, El Salvador, India, Israel, Malaysia, Mexico, Nepal, Pakistan, the Philippines, Sri Lanka, and Taiwan regulatory authorities for emergency usage in their respective countries.
South Korea granted approval of the AstraZeneca vaccine on 10 February 2021, thus becoming the first vaccine to be approved for use in that country. The regulator recommended the two-shot regimen be used in all adults, including the elderly, noting that consideration is needed when administering the vaccine to individuals over 65 years of age due to limited data from that demographic in clinical trials. On the same day, the World Health Organization (WHO) issued interim guidance and recommended the AstraZeneca vaccine for all adults, its Strategic Advisory Group of Experts also having considered use where variants were present and concluded there was no need not to recommend it.
In February 2021, the government and regulatory authorities in Australia (16 February 2021) and Canada (26 February 2021) granted approval for temporary use of the vaccine.
On 19 November 2021, the vaccine was approved for use in Canada.
Suspensions
South Africa
On 7 February 2021, the vaccine rollout in South Africa was suspended. Researchers from the University of the Witwatersrand released interim, non-peer-reviewed data that suggested the AstraZeneca vaccine provided minimal protection against mild or moderate disease infection among young people. The BBC reported on 8 February 2021 that Katherine O'Brien, director of immunisation at the WHO, felt it was "really plausible" the AstraZeneca vaccine could have a "meaningful impact" on the Beta variant (lineage B.1.351), particularly in preventing serious illness and death. The same report also indicated the Deputy Chief Medical Officer for England Jonathan Van-Tam said the Witwatersrand study did not change his opinion that the AstraZeneca vaccine was "rather likely" to have an effect on severe disease from the Beta variant. The South African government subsequently cancelled the use of the AstraZeneca vaccine.
European Union
In March 2021, Austria suspended the use of one batch of vaccine after two people had blood clots after vaccination, one of whom died. In total, four cases of blood clots have been identified in the same batch of 1million doses. Although no causal link with vaccination has been shown, several other countries, including Denmark, Norway, Iceland, Bulgaria, Ireland, Italy, Spain, Germany, France, the Netherlands and Slovenia also halted the vaccine rollout over the following days while waiting for the EMA to finish a safety review triggered by the cases.
In April 2021, the EMA concluded its safety review and concluded that unusual blood clots with low blood platelets should be listed as very rare side effects while reaffirming the overall benefits of the vaccine. Following this announcement EU countries have resumed use of the vaccine with some limiting its use to elderly people at higher risk for severe COVID-19 illness.
In March 2021, the Norwegian government temporarily suspended the vaccine's use, awaiting more information regarding potential adverse effects. Then, in April, the Norwegian Institute of Public Health recommended to the government to permanently suspended vaccination with AstraZeneca due to the "rare but severe incidents with low platelet counts, blood clots, and haemorrhages," since in the case of Norway, "the risk of dying after vaccination with the AstraZeneca vaccine would be higher than the risk of dying from the disease, particularly for younger people." At the same time, the Norwegian government announced their decision to wait for a final decision and to establish an expert group to provide a broader assessment on the safety of the AstraZeneca and Janssen vaccines. In May, the expert committee also recommended suspending the use of both vaccines. Finally, in May —two months after the initial suspension— the Prime Minister of Norway announced that the government decided to completely remove the AstraZeneca vaccine from the Norwegian Coronavirus Immunisation Programme, and people who have had the first will be offered another coronavirus vaccine for their second dose.
In March 2021, the German Ministry of Health announced that the use of the vaccine in people aged 60 and below should be the result of a recipient-specific discussion, and that younger patients could still be given the AstraZeneca vaccine, but only "at the discretion of doctors, and after individual risk analysis and thorough explanation".
In April, the Danish Health Authority suspended use of the vaccine. The Danish Health Authority said that it had other vaccines available, and that the next target groups being a lower-risk population had to be "[weighed] against the fact that we now have a known risk of severe adverse effects from vaccination with AstraZeneca, even if the risk in absolute terms is slight."
A 2021 study found that the decisions to suspend the vaccine led to increased vaccine hesitancy across the West, even in countries that did not suspend the vaccine.
In October 2022, the conditional marketing authorisation was converted to a standard one.
Despite the continued authorisation, most EU countries stopped the administration of the vaccine by end of 2021. After an initial quick uptake, the number of doses administered remained at 67 Million since October 2021.
AstraZeneca withdrew its marketing authorization for the vaccine from the European Union in March 2024.
Canada
On 29 March 2021, Canada's National Advisory Committee on Immunization (NACI) recommended that distribution of the vaccine be suspended for patients below the age of 55; NACI chairwoman Caroline Quach-Thanh stated that the risk of blood clots was higher in younger patients, and that NACI needed to "evolve" its recommendations as new data becomes available. Most Canadian provinces subsequently announced that they would follow this guidance. there had been three confirmed cases of blood clotting tied to the vaccine in Canada, out of over 700,000 doses administered in the country.
Beginning 18 April 2021, amid a major third wave of the virus, several Canadian provinces announced that they would backtrack on the NACI recommendation and extend eligibility for the AstraZeneca vaccine to residents as young as 40 years old, including Alberta, British Columbia, Ontario, and Saskatchewan. Quebec also extended eligibility to residents 45 and older. The NACI guidance was a recommendation which did not affect the formal approval of the vaccine by Health Canada for all adults over 18; it stated on 14 April 2021 that it had updated its warnings on the vaccine as part of an ongoing review, but that "the potential risk of these events is very rare, and the benefits of the vaccine in protecting against COVID-19 outweigh its potential risks."
On 23 April 2021, citing the current state of supplies for mRNA-based vaccines and new data, NACI issued a recommendation that the vaccine could be offered to patients as young as 30 years old if benefits outweighed the risks, and the patient did "not wish to wait for an mRNA vaccine".
Beginning 11 May 2021, multiple provinces announced that they would suspend use of the AstraZeneca vaccine once again, citing either supply issues or the blood clotting risk. Some provinces stated that they planned to only use the AstraZeneca vaccine for outstanding second doses. On 1 June 2021, NACI issued guidance, citing the safety concerns as well as European studies showing an improved antibody response, recommending that an mRNA vaccine be administered as a second dose to patients that had received the AstraZeneca vaccine as their first dose.
Indonesia
In March 2021, Indonesia halted the rollout of the vaccine while awaiting more safety guidance from the World Health Organization, and then resumed using the vaccine on 19 March.
Australia
In June 2021, Australia revised its recommendations for the rollout of the vaccine, recommending that the Pfizer Comirnaty vaccine be used for people aged under 60 years if the person has not already received a first dose of AstraZeneca COVID-19 vaccine. The AstraZeneca COVID-19 vaccine can still be used in people aged under 60 years where the benefits are likely to outweigh the risks for that person, and the person has made an informed decision based on an understanding of the risks and benefits in consultation with a medical professional.
Malaysia
After initially approving the use of the AstraZeneca vaccine, Malaysian health authorities removed the vaccine from the country's mainstream vaccination programme due to public concerns about its safety in late April 2021. The AstraZeneca vaccines was distributed in designated vaccination centres, with the public being allowed to register for the vaccine on a voluntary basis. All 268,800 doses of the initial batch of the vaccine were fully booked in three and a half hours after the registration opened for residents of the state of Selangor and the Federal Territory of Kuala Lumpur. A second batch of 1,261,000 doses was offered to residents of the states of Selangor, Penang, Johore, Sarawak, and the Federal Territory of Kuala Lumpur. A total of 29,183 doses were reserved for previously waitlisted registrants, and 275,208 doses were taken up by senior citizens during a grace 3-day period. The remaining 956,609 doses were then offered to those aged 18 and above, and was completely booked within an hour.
On 10 May 2024, Health Minister Dzulkefly Ahmad announced that the Malaysian Government would continue to offer care to individuals suffering from adverse effects of COVID-19 vaccines including the AstraZeneca vaccine. He also confirmed that the Malaysian Government had data on adverse effects caused by COVID-19 vaccines and methods for treating the side effects. On 13 May, Deputy Health Minister Lukanisman Awang Sauni confirmed that the Malaysian Government would release a report on the AstraZeneca vaccine's adverse effects later in the week.
Safety review
In March 2021, the European Medicines Agency (EMA) stated that there is no indication that vaccination has been the cause of the observed clotting issues, which were not listed as side effects of the vaccine. At the time, according to the EMA, the number of thromboembolic events in vaccinated people was no higher than that seen in the general population. , 30 cases of events of thromboembolism events had been reported among the almost 5million people vaccinated in the European Economic Area. The UK's MHRA also stated that after more than 11million doses administered, it had not been confirmed that the reported blood clots were caused by the vaccine and that vaccinations would not be stopped. On 12 March 2021 the WHO stated that a causal relationship had not been shown and that vaccinations should continue. AstraZeneca confirmed on 14 March 2021 that after examining over 17million people who have been vaccinated with the vaccine, no evidence of an increased risk of blood clots in any particular country was found. The company reported that , across the EU and UK, there had been 15 events of deep vein thrombosis and 22 events of pulmonary embolism reported among those given the vaccine, which is much lower than would be expected to occur naturally in a general population of that size.
In March 2021, the German Paul-Ehrlich Institute (PEI) reported that out of 1.6million vaccinations, seven cases of cerebral vein thrombosis in conjunction with a deficiency of blood platelets had occurred. According to the PEI, the number of cases of cerebral vein thrombosis after vaccination was statistically significantly higher than the number that would occur in the general population during a similar time period. These reports prompted the PEI to recommend a temporary suspension of vaccinations until the EMA had completed their review of the cases.
The World Health Organization (WHO) issued a statement on 17 March, regarding the AstraZeneca COVID-19 vaccine safety signals, and still considers the benefits of the vaccine to outweigh its potential risks, further recommending that vaccinations continue. On 18 March, the EMA announced that out of the around 20million people who had received the vaccine, general blood clotting rates were normal, but that it had identified seven cases of disseminated intravascular coagulation, and eighteen cases of cerebral venous sinus thrombosis. A causal link with the vaccine was not proven, but the EMA said it would conduct further analysis and recommended informing people eligible for the vaccine of the fact that the possibility it may cause rare clotting problems had not been disproven. The EMA confirmed that the vaccine's benefits outweighed the risks. On 25 March, the EMA released updated product information.
According to the EMA, 100,000 cases of blood clots occur naturally each month in the EU, and the risk of blood clots was not statistically higher in the vaccinated population. The EMA noted that COVID-19 itself causes an increased risk of the development of blood clots, and as such the vaccine would lower the risk of the formation of blood clots even if the 15 cases' causal link were to be confirmed. Italy resumed vaccinations after the EMA's statement, with most of the remaining European countries following suit and resuming their AstraZeneca inoculations shortly thereafter. To reassure the public of the vaccine's safety, the British and French Prime Ministers, Boris Johnson and Jean Castex, had themselves vaccinated with it in front of the media shortly after the restart of the AstraZeneca vaccination campaigns in the EU.
In April 2021, the EMA issued its direct healthcare professional communication (DHPC) about the vaccine.
The DHPC indicated that a causal relationship between the vaccine and blood clots (thrombosis) in combination with low blood platelets (thrombocytopenia) was plausible and identified it as a very rare side effect of the vaccine. According to the EMA these very rare adverse events occur in around 1 out of 100,000 vaccinated people.
Further development
Efficacy against variants
A study published in April 2021 by researchers from the COVID-19 Genomics United Kingdom Consortium, the AMPHEUS Project, and the Oxford COVID-19 Vaccine Trial Group indicated the Oxford–AstraZeneca vaccine showed somewhat reduced efficacy against infection with the Alpha variant (lineage B.1.1.7), with 70.4% efficacy in absolute terms against Alpha versus 81.5% against other variants. Despite this, the researchers concluded that the vaccine remained effective at preventing symptomatic infection from this variant and that vaccinated individuals infected symptomatically typically had shorter duration of symptoms and less viral load, thereby reducing the risk of transmission. Following the identification of notable variants of concern, concern arose that the E484K mutation, present in the Beta and Gamma variants (lineages B.1.351 and P.1), could evade the protection given by the vaccine. In February 2021, the collaboration was working to adapt the vaccine to target these variants, with the expectation that a modified vaccine would be available "in a few months" as a "booster" given to people who had already completed the two-dose series of the original vaccine.
In June 2021, AstraZeneca published a press release confirming undergoing Phase II/III trials of an AZD2816 COVID-19 variant vaccine candidate. The new vaccine would be based on the current Vaxzevria adenoviral vector platform but modified with spike proteins based on the Beta (B.1.351 lineage) variant. Phase II/III trials saw 2849 volunteers participating from UK, South Africa, Brazil and Poland with parallel dosing of both the current Oxford-AstraZeneca vaccine and the variant vaccine candidate. By September 2021, AZD2816 vaccine candidate is still undergoing Phase II/III trials with intent to switch to this vaccine if approved by government regulators. Particularly the government of Thailand, with delivery of additional 60 million doses of AstraZeneca COVID-19 Vaccine agreed for 2022.
Heterologous prime-boost vaccination
In December 2020, a clinical trial was registered to examine a heterologous prime-boost vaccination course consisting of one dose of the Oxford–AstraZeneca vaccine followed by Sputnik Light based on the Ad26 vector 29 days later.
After suspensions due to rare cases of blood clots in March 2021, Canada and several European countries recommended receiving a different vaccine for the second dose. Despite the lack of clinical data on the efficacy and safety of such heterologous combinations, some experts believe that doing so may boost immunity, and several studies have begun to examine this effect.
In June 2021, preliminary results from a study of 463 participants showed that a heterologous prime-boost vaccination course consisting of one dose of the Oxford–AstraZeneca vaccine followed by one dose of the Pfizer–BioNTech vaccine produced the strongest T cell activity and an antibody level almost as high as two doses of the Pfizer-BioNTech vaccine. The reversal of the order resulted in T cell activity at half the potency and one-seventh the antibody levels, the latter still five times higher than two doses of Oxford–AstraZeneca. The lowest T cell activity was observed in homologous courses, when both doses were of the same vaccine.
In July 2021, a study of 216 participants found that a heterologous prime-boost vaccination course consisting of one dose of the Oxford–AstraZeneca vaccine followed by one dose of the Moderna vaccine produced a similar level of neutralizing antibodies and T cell responses with increased spike-specific cytotoxic T cells compared to a homologous course consisting of two doses of the Moderna vaccine.
Society and culture
The Oxford University and AstraZeneca collaboration was seen as having the potential as being a low-cost vaccine with no onerous storage requirements. A series of events including a deliberate undermining of the AstraZeneca vaccine for geopolitical purposes by both the EU and EU member states including miscommunication, reports of supply difficulties (responsibility of which were due to the EU mis-handling vaccine procurement) misleading reports of inefficacy and adverse effects as well as the high-profile European Commission–AstraZeneca COVID-19 vaccine dispute, have been a public relations disaster for both Brussels and member states, and in the opinion of one academic has led to increased vaccine hesitancy.
In April 2021, the vaccine was a key component of the WHO backed COVAX (COVID-19 Vaccines Global Access) program, with the WHO, the EMA, and the MHRA continuing to state that the benefits of the vaccine outweigh any possible side effects.
About 69million doses of the Oxford–AstraZeneca COVID-19 vaccine were administered in the EU/EEA from authorization to 26 June 2022.
Economics
Agreements for access to vaccines began being signed in May 2020, with the UK having priority for the first 100million doses if trials proved successful, with the final agreement being signed at the end of August.
On 21 May 2020, AstraZeneca agreed to provide 300million doses to the US for , implying a cost of per dose. An AstraZeneca spokesman said the funding also covers development and clinical testing. It also reached a technology transfer agreement with the Mexican and Argentinean governments and agreed to produce at least 400million doses to be distributed throughout Latin America. The active ingredients would be produced in Argentina and sent to Mexico to be completed for distribution. In June 2020, Emergent BioSolutions signed a deal to manufacture doses of the AstraZeneca vaccine specifically for the US market. The deal was part of the Trump administration's Operation Warp Speed initiative to develop and rapidly scale production of targeted vaccines before the end of 2020. Catalent would be responsible for the finishing and packaging process.
On 4 June 2020, the WHO's COVAX (COVID-19 Vaccines Global Access) facility made initial purchases of 300million doses from the company for low- to middle-income countries. Also, AstraZeneca and Serum Institute of India reached a licensing agreement to independently supply 1billion doses of the Oxford University vaccine to middle- and low-income countries, including India. Later in September, funded by a grant from the Bill and Melinda Gates Foundation, the COVAX program secured an additional 100 million doses at US$3 per dose.
On 27 August 2020, AstraZeneca concluded an agreement with the EU, to supply up to 400million doses to all EU and select European Economic Area (EEA) member states. The European Commission took over negotiations started by the Inclusive Vaccines Alliance, a group made up of France, Germany, Italy, and the Netherlands, in June 2020.
On 5 November 2020, a tripartite agreement was signed between the government of Bangladesh, the Serum Institute of India, and Beximco Pharma of Bangladesh. Under the agreement Bangladesh ordered 30million doses of Oxford–AstraZeneca vaccine from Serum through Beximco for $4 per shot. On the other hand, Indian government has given 3.2 million doses to Bangladesh as a gift which were also produced by Serum. But Serum supplied only 7 million doses from the tripartite agreement in the first two months of the year. Bangladesh was supposed to receive 5 million doses per month but not received shipments in March and April. As a result, rollout of vaccine has been disrupted by supply shortfalls. The situation became complicated when the second dose of 1.3 million citizens is uncertain as India halts exports. Not getting the second dose at the right time is likely to reduce the effectiveness of the vaccination program. In addition, several citizens of Bangladesh have expressed doubts about its effectiveness and safety. Bangladesh is looking for alternative vaccine sources because India isn't supplying the vaccine according to the timeline of the deal.
Thailand's agreement in November 2020 for 26million doses of vaccine would cover 13million people, approximately 20% of the population, with the first lot expected to be delivered at the end of May. The public health minister indicated the price paid was $5 per dose; AstraZeneca (Thailand) explained in January 2021 after a controversy that the price each country paid depended on production cost and differences in supply chain, including manufacturing capacity, labour and raw material costs. In January 2021, the Thai cabinet approved further talks on ordering another 35million doses, and the Thai FDA approved the vaccine for emergency use for 1year. Siam Bioscience, a company owned by Vajiralongkorn, will receive technological transfer and has the capacity to manufacture up to 200million doses a year for export to ASEAN.
Also in November, the Philippines agreed to buy 2.6million doses, reportedly worth around million (approximately per dose). In December 2020, South Korea signed a contract with AstraZeneca to secure 20million doses of its vaccine, reportedly equivalent in worth to those signed by Thailand and the Philippines, with the first shipment expected as early as January 2021. , the vaccine remains under review by the South Korea Disease Control and Prevention Agency. AstraZeneca signed a deal with South Korea's SK Bioscience to manufacture its vaccine products. The collaboration calls for the SK affiliate to manufacture AZD1222 for local and global markets.
On 7 January 2021, the South African government announced that they had secured an initial 1million doses from the Serum Institute of India, to be followed by another 500,000 doses in February, however the South African government subsequently cancelled the use of the vaccine, selling its supply to other African countries, and switched its vaccination program to use the Janssen COVID-19 vaccine.
On 22 January 2021, AstraZeneca announced that in the event the European Union approved the COVID-19 Vaccine AstraZeneca, initial supplies would be lower than expected due to production issues at Novasep in Belgium. Only 31million of the previously predicted 80million doses would be delivered to the EU by March 2021. In an interview with Italian newspaper La Repubblica, AstraZeneca's CEO Pascal Soriot said the delivery schedule for the doses in the EU was two months behind schedule. He mentioned low yield from cell cultures at one large-scale European site. Analysis published in The Guardian also identified an apparently low yield from bioreactors in the Belgium plant and noted the difficulties in setting up this form of process, with variable yields often occurring. As a result, the EU imposed export controls on vaccine doses; controversy erupted as to whether doses were being diverted to the UK and whether deliveries to Northern Ireland would be disrupted.
On 24 February 2021, a shipment of the vaccine to Accra, Ghana, via COVAX made it the first country in Africa to receive vaccines via the initiative.
In early 2021, the Bureau for Investigative Journalism found that South Africa had paid double the rate for the European Commission, while Uganda paid triple.
According to the Higher Education Statistics Agency data, Oxford received a US$176 million windfall on vaccine in the 2021-22 academic year.
Brand names
The vaccine is marketed under the brand name Covishield by the Serum Institute of India. The name of the vaccine was changed to Vaxzevria in the European Union on 25 March 2021. Vaxzevria, AstraZeneca COVID‐19 Vaccine, and COVID-19 Vaccine AstraZeneca are manufactured by AstraZeneca.
Research
, the AZD1222 development team were working on adapting the vaccine to be more effective in relation to newer SARS-CoV-2 variants; redesigning the vaccine being the relatively quick process of switching the genetic sequence of the spike protein. Manufacturing set-up and a small scale trial are also required before the adapted vaccine might be available in autumn.
References
Further reading
External links
"An oral history of Oxford/AstraZeneca: 'Making a vaccine in a year is like landing a human on the moon'". The Guardian
Adenoviridae
Drugs developed by AstraZeneca
British COVID-19 vaccines
Products introduced in 2020
Vaccine controversies
Viral vector vaccines
Withdrawn drugs | Oxford–AstraZeneca COVID-19 vaccine | [
"Chemistry",
"Biology"
] | 9,255 | [
"Vaccination",
"Withdrawn drugs",
"Drug safety",
"Vaccine controversies"
] |
64,586,800 | https://en.wikipedia.org/wiki/NGC%20600 | NGC 600 is an emission-line galaxy in the constellation Cetus. It was discovered by William Herschel on 10 September 1785. The galaxy has a diameter of 70,000 light-years. It is also approximately 90 million light-years from the Milky Way.
See also
List of NGC objects
List of NGC objects (1–1000)
References
External links
600
-01-05-007
005777
Cetus
Barred spiral galaxies
Galaxies discovered in 1785
Discoveries by William Herschel | NGC 600 | [
"Astronomy"
] | 99 | [
"Cetus",
"Constellations"
] |
64,586,975 | https://en.wikipedia.org/wiki/CYP119A1 | Cytochrome P450 family 119 subfamily A member 1 (abbreviated CYP119A1) is an Archaeal Cytochrome P450 enzyme originally from the thermophillic archea Sulfolobus solfataricus. Because this enzyme usually has the maximum activity at high temperature and low activity at room temperature, it is often used in the study of enzyme catalytic mechanism.
References
Cytochrome P450
Archaeal genes | CYP119A1 | [
"Biology"
] | 94 | [
"Archaea",
"Archaeal genes"
] |
64,588,739 | https://en.wikipedia.org/wiki/C3H2Cl6 | {{DISPLAYTITLE:C3H2Cl6}}
The molecular formula C3H2Cl6 (molar mass: 250.766 g/mol, exact mass: 247.8288 u) may refer to:
1,1,1,3,3,3-Hexachloropropane
1,1,2,2,3,3-Hexachloropropane | C3H2Cl6 | [
"Chemistry"
] | 91 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
64,589,237 | https://en.wikipedia.org/wiki/Christopher%20Chetsanga | Christopher J. Chetsanga (born 1935 in Murehwa, Rhodesia) is a prominent Zimbabwean scientist who is a member of the African Academy of Sciences and The World Academy of Sciences. He discovered two enzymes involved in DNA repair. He has also held various academic administrative posts like Vice-Chancellor, Director and Dean.
Biography
Chetsanga was born in Murewa, Zimbabwe on 22 August 1935, and was baptised in 1948. In his youth, he was educated at Nhowe Mission, and went on to study at University of California, Berkeley where he received his BSc in 1965. Chetsanga also studied for a period at Pepperdine University. In 1969, he received his MSc and PhD in biochemistry and molecular biology from University of Toronto before becoming a post doctoral fellow at Harvard University between 1969 and 1972. Between 1972 and 1983 he became a professor at the University of Michigan, then in 1983 he left to become the senior lecturer in Biochemistry for University of Zimbabwe. In 1990, President Robert Mugabe awarded him President’s Award for Distinguished Contribution to Science and Technology. Has also awarded the Order of the Star of Zimbabwe. He is presently the vice chancellor at Zimbabwe Ezekiel Guti University.
In 2004, when the Zimbabwe Academy of Sciences was formed, Chetsanga was appointed the first president of the academy. Chetsanga advocated the use of genetically modified food sources as a possible solution for food shortages in Africa in 2020.
Scientific Achievements
Chetsanga has discovered two enzymes involved in the repair of damaged DNA: firstly, formamidopyrimidine DNA glycosylase, which removes damaged 7-methylguanine from DNA (1979), and secondly, purine imidazole-ring cyclase, which re-closes imidazole rings of guanine and adenine damaged by x-irradiation (1985).
According to Chetsanga, his research focus in his scientific career has been on DNA and RNA structural and functional details as they relate to cellular metabolism and disease development.
Select publications
References
External links
Brief Curriculum Vitae, University of Zimbabwe, Department of Biochemistry
Zimbabwean scientists
1935 births
Living people
Biochemists
People from Mashonaland East Province
University of California alumni
Pepperdine University alumni
University of California, Berkeley alumni
University of Toronto alumni
University of Michigan faculty
Academic staff of the University of Zimbabwe
Fellows of the African Academy of Sciences
Fellows of the Zimbabwe Academy of Sciences | Christopher Chetsanga | [
"Chemistry",
"Biology"
] | 489 | [
"Biochemistry",
"Biochemists"
] |
64,589,821 | https://en.wikipedia.org/wiki/CYP710%20family | Cytochrome P450, family 710, also known as CYP710, is a plant cytochrome P450 monooxygenase family, the proteins encoded by its family members are mainly sterol 22-desaturase, which was widely distributed in plants, and take participate in Phytosteroidogenesis. CYP710 family is considered to be the plant orthologous of fungi CYP61 family, which is lost in animal. The CYP61/CYP710 ancestor gene diverged from a gene duplication of ancestor CYP51 in early eukaryotes
References
Plant genes
710
Protein families | CYP710 family | [
"Biology"
] | 137 | [
"Protein families",
"Protein classification"
] |
64,591,279 | https://en.wikipedia.org/wiki/The%20Machine%20in%20Neptune%27s%20Garden | The Machine in Neptune's Garden: Historical Perspectives on Technology and the Marine Environment is a 2004 book edited by Helen M. Rozwadowski and David K. van Keuren. The book takes its name from Leo Marx's influential book The Machine in the Garden. It is a product of the Maury III conference on the history of oceanography held in Monterey, California in 2001. It argues the centrality of technology to the acquisition of knowledge of the oceans and contains ten thematically linked essays on the indispensable role of technology in the history of ocean science. It "demonstrate[s] that historians of science and technology should pay more attention to the history and historiography of oceanography." It is the most prominent work combining the history of technology, environmental history, and history of ocean sciences, and it is considered a foundational work in history of technology of the oceans and in the history of the marine environment.
Contents
The book contains an introduction by Keith R. Benson and editors Helen M. Rozwadowski and David K. van Keuren, and ten chapters by historians of science and technology. The volume is dedicated to historian of science Philip F. Rehbock, who had died in 2002.
1. "Gauging Science and Technology in the Early Victorian Era" by Michael S. Reidy
2. "Mathematics in Neptune's Garden: Making the Physics of the Sea Quantitative, 1876-1900" by Eric L. Mills
3. "Fashioning Naval Oceanography: Columbus O'Donnell Iselin and American Preparation for War 1940-1941" by Gary E. Weir
4. "'A Wonderful Oceanographic Tool': The Atomic Bomb, Radioactivity and the Development of American Oceanography" by Ronald Rainger
5. "Choosing between Centers of Action: Instrument Buoys, El Niño, and Scientific Internationalism in the Pacific, 1957-1983" by Gregory T. Cushman
6. "Breaking New Ground: The Origins on Scientific Ocean Drilling" by David K. van Keuren
7. "An Eye into the Sea: The Early Development of Fisheries Acoustics in Norway, 1935-1960" by Vera Schwach
8. "From Civilian Plantonologist to Navy Oceanographer: Mary Sears in World War II" by Kathleen Broome Williams
9. "Modeling Neptune's Garden: The Chesapeake Bay Hydraulic Model, 1965-1984" by Christine Keiner
10. "Engineering, Imagination, and Industry: Scripps Island and Dreams for Ocean Science in the 1960s" by Helen M. Rozwadowski
References
2004 non-fiction books
History of science and technology
Environmental history
Environmental non-fiction books
Maritime history
Naval history
Oceanography | The Machine in Neptune's Garden | [
"Physics",
"Technology",
"Environmental_science"
] | 549 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics",
"History of science and technology"
] |
64,591,593 | https://en.wikipedia.org/wiki/Rescuer%20%28genocide%29 | During a genocide, a rescuer or helper is someone who tries to help the genocide victims survive. In many cases, they are motivated by altruism and/or humanitarianism. The best-studied example of this phenomenon is the rescue of Jews during the Holocaust.
See also
Perpetrators, victims, and bystanders
Rescue of Roma during the Porajmos
References
Further reading
Bibliography of genocide studies
Genocide studies
Altruism | Rescuer (genocide) | [
"Biology"
] | 87 | [
"Behavior",
"Altruism"
] |
64,593,287 | https://en.wikipedia.org/wiki/Parbelos | The parbelos is a figure similar to the arbelos but instead of three half circles it uses three parabola segments. More precisely the parbelos consists of three parabola segments, that have a height that is one fourth of the width at their bases. The two smaller parabola segments are placed next to each other with their bases on a common line and the largest parabola is placed over the two smaller ones such that its width is the sum of the widths of the smaller ones (see graphic).
The parbelos has a number of properties which are somewhat similar or even identical to the properties of the Arbelos. For instance, the following two properties are identical to those of the arbelos:
The arc length of the outer parabola is equal to the sum of the arc lengths of the inner parabolas.
In a nested arbelos construction with the inner parabola segments being arbeloses themselves the two innermost parabola segments being adjacent to the cusp of the outer arbelos are congruent, that is of equal size.
The quadrilateral formed by the inner cusp and the midpoints of the three parabola arcs is a parallelogram the area of which relates to the area of the parbelos as follows:
The four tangents at the three cusps of the parabola intersect in four points, which form a rectangle being called the tangent rectangle. The circumcircle of the tangent rectangle intersects the base side of the outer parabola segment in its midpoint, which is the focus of the outer parabola. One diagonal of the tangent rectangle lies on a tangent to the outer parabola and its common point with it is identical to its point of intersection with perpendicular to the base at the inner cusp. For the area of the tangent rectangle the following equation holds:
References
Further reading
Emmanuel Tsukerman: "Solution of Sondow’s Problem: A Synthetic Proof of the Tangency Property of the Parbelos". In: The American Mathematical Monthly**, Vol. 121, No. 5 (May 2014), pp. 438-443
Antonio M. Oller-Marcén: "The f-belos". In: Forum Geometricorum'', 13 (2013), pp. 103–111 (online copy)
Viktorija Ternar: Arbelos, parabelos in f-belos (master thesis, University of Maribor, 2015)
Geometric shapes | Parbelos | [
"Mathematics"
] | 514 | [
"Geometric shapes",
"Mathematical objects",
"Geometric objects"
] |
64,593,371 | https://en.wikipedia.org/wiki/The%20Oyster%20Question | The Oyster Question: Scientists, Watermen, and the Maryland Chesapeake Bay since 1880 is a 2009 book by Christine Keiner. It examines the conflict between oystermen and scientists in the Chesapeake Bay from the end of the nineteenth century to the present, which includes the period of the so-called "Oyster Wars" and the precipitous decline of the oyster industry at the end of the twentieth century. The book engages the myth of the "Tragedy of the Commons" by examining the often fraught relationship between local politics and conservation science, arguing that for most of the period Maryland's state political system gave rural oystermen more political clout than politicians and the scientists they appointed and allowing oystermen to effectively manage the oyster bed commons. Only towards the end of the twentieth century did reapportionment bring suburban and urban interests more political power, by which time they had latched on to oystermen as elements of the area's heritage and incorporated them and the oysters into broader conservation efforts. An important theme is the "intersection[] of scientific knowledge with experiential knowledge in the context of use," in that Keiner "treats the knowledge of the Chesapeake Bay’s oystermen alongside that of biologists." "Through her analysis, Keiner effectively reframes how environmental historians have analyzed histories of common resources and provides a working model for integrating historical and ecological information to bridge the histories of science and environmental history."
Awards
The book won the 2010 Forum for the History of Science in America Prize. It shared the 2010 Maryland Historical Trust's Heritage Book Award, and received an Honorable Mention for the Frederick Jackson Turner Award from the Organization of American Historians in 2010.
References
2009 non-fiction books
History of science and technology
Environmental non-fiction books
Maritime history
Oceanography
Environmental history of the United States | The Oyster Question | [
"Physics",
"Technology",
"Environmental_science"
] | 369 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics",
"History of science and technology"
] |
64,593,665 | https://en.wikipedia.org/wiki/Plane%E2%80%93plane%20intersection | In analytic geometry, the intersection of two planes in three-dimensional space is a line.
Formulation
The line of intersection between two planes and where are normalized is given by
where
Derivation
This is found by noticing that the line must be perpendicular to both plane normals, and so parallel to their cross product (this cross product is zero if and only if the planes are parallel, and are therefore non-intersecting or entirely coincident).
The remainder of the expression is arrived at by finding an arbitrary point on the line. To do so, consider that any point in space may be written as , since is a basis. We wish to find a point which is on both planes (i.e. on their intersection), so insert this equation into each of the equations of the planes to get two simultaneous equations which can be solved for and .
If we further assume that and are orthonormal then the closest point on the line of intersection to the origin is . If that is not the case, then a more complex procedure must be used.
Dihedral angle
Given two intersecting planes described by and , the dihedral angle between them is defined to be the angle between their normal directions:
References
Euclidean geometry
Computational physics
Geometric algorithms
Geometric intersection
Planes (geometry) | Plane–plane intersection | [
"Physics",
"Mathematics"
] | 254 | [
"Planes (geometry)",
"Infinity",
"Mathematical objects",
"Computational physics"
] |
63,241,541 | https://en.wikipedia.org/wiki/9%20Cygni | 9 Cygni is a binary star system in the northern constellation of Cygnus. 9 Cygni is its Flamsteed designation. The two stars have a combined magnitude of 5.39, so it can be seen with the naked eye under good viewing conditions. Parallax measurements made by Gaia put the star at a distance of around () away.
The two stars of 9 Cygni are a G-type giant and an A-type star. Both stars are over twice as massive as the Sun. They orbit once every 4.56 years, separated with a semi-major axis of . However, the eccentricity is high, at 0.82. The primary is a red clump giant, a star on the cool end of the horizontal branch fusing helium in its core. The secondary star has begun to evolve off the main sequence; it is sometimes classified as a giant star and sometimes as a main-sequence star.
References
See also
Spectroscopic binary
G-type giants
A-type main-sequence stars
Binary stars
Cygnus (constellation)
Durchmusterung objects
Cygni, 9
184759
096302
7441 | 9 Cygni | [
"Astronomy"
] | 237 | [
"Cygnus (constellation)",
"Constellations"
] |
63,241,811 | https://en.wikipedia.org/wiki/Pyrrole%E2%80%93imidazole%20polyamides | Pyrrole–imidazole polyamides (PIPs) are a class of polyamides have the ability to bind to minor grooves found in the DNA helix. Scientists are experimenting with it as a drug-delivery mode that can switch genes on and off, as well as epigenetic modification in gene therapy.
References
Gene therapy | Pyrrole–imidazole polyamides | [
"Engineering",
"Biology"
] | 72 | [
"Biotechnology stubs",
"Gene therapy",
"Genetic engineering"
] |
63,243,022 | https://en.wikipedia.org/wiki/David%20Soudry | David Soudry (born 1956) is a professor of mathematics at Tel Aviv University working in number theory and automorphic forms.
Career
Soudry was born in 1956. He received his PhD in mathematics from Tel Aviv University in 1983 under the supervision of Ilya Piatetski-Shapiro. From 1983 to 1984, he was a member of the Institute for Advanced Study. He is a professor of mathematics at Tel Aviv University.
Research
Together with Stephen Rallis and David Ginzburg, Soudry wrote a series of papers about automorphic descent culminating in their book The descent map from automorphic representations of GL(n) to classical groups. Their automorphic descent method constructs an explicit inverse map to the (standard) Langlands functorial lift and has had major applications to the analysis of functoriality. Also, using the "Rallis tower property" from Rallis's 1984 paper on the Howe duality conjecture, they studied global exceptional correspondences and found new examples of functorial lifts.
Selected publications
References
External links
20th-century Israeli mathematicians
21st-century Israeli mathematicians
Number theorists
Living people
Date of birth missing (living people)
Place of birth missing (living people)
Tel Aviv University alumni
Academic staff of Tel Aviv University
Institute for Advanced Study visiting scholars
1956 births | David Soudry | [
"Mathematics"
] | 262 | [
"Number theorists",
"Number theory"
] |
63,243,143 | https://en.wikipedia.org/wiki/Dihua%20Jiang | Dihua Jiang (, born 1958) is a Chinese-born American mathematician. He is a professor of mathematics at the University of Minnesota working in number theory, automorphic forms, and the Langlands program.
Early life and education
In 1958, Jiang was born in the Lucheng District of Wenzhou, Zhejiang. He studied at Wenzhou No. 3 Middle School before studying at Zhejiang Normal University, where he received his bachelor's degree in mathematics in 1982. He received a master's degree from East China Normal University in 1987 and a PhD in mathematics from Ohio State University in 1994 under the supervision of Stephen Rallis.
Career
Jiang joined the faculty at the Department of Mathematics at the University of Minnesota in 1998 and became a full professor in 2004.
Awards
Jiang was a recipient of a Sloan Research Fellowship and was inducted as a Fellow of the American Mathematical Society in 2019.
Selected publications
Degree 16 standard L-function of GSp(2)×GSp(2). Mem. Amer. Math. Soc. 123 (1996), no. 588, viii+196 pp.
With Ilya Piatetski-Shapiro: Arithmeticity of discrete subgroups and automorphic forms. Geom. Funct. Anal. 8 (1998), no. 3, 586–605.
With Wee Teck Gan and Nadya Gurevich: Cubic unipotent Arthur parameters and multiplicities of square integrable automorphic forms. Invent. Math. 149 (2002), no. 2, 225-265.
With David Soudry: The local converse theorem for SO(2n+1) and applications. Annals of Mathematics (2) 157 (2003), no. 3, 743-806.
With David Ginzburg and Stephen Rallis: On the nonvanishing of the central value of the Rankin-Selberg L-functions. J. Amer. Math. Soc. 17 (2004), no. 3, 679–722.
On the fundamental automorphic L-functions of SO(2n+1). Int. Math. Res. Not. 2006, Art. ID 64069, 26 pp.
With Jian-Shu Li and Shou-Wu Zhang: Periods and distribution of cycles on Hilbert modular varieties. Pure Appl. Math. Q. 2 (2006), no. 1, Special Issue: In honor of John H. Coates. Part 1, 219–277.
With Binyong Sun and Chen-Bo Zhu: Uniqueness of Bessel models: the Archimedean case. Geom. Funct. Anal. 20 (2010), no. 3, 690–709.
Automorphic integral transforms for classical groups I: Endoscopy correspondences. Automorphic forms and related geometry: assessing the legacy of I. I. Piatetski-Shapiro, 179–242, Contemp. Math., 614, Amer. Math. Soc., Providence, RI, 2014.
With Chufeng Nien and Shaun Stevens: Towards the Jacquet conjecture on the local converse problem for p-adic GLn. J. Eur. Math. Soc. (JEMS) 17 (2015), no. 4, 991–1007.
With Lei Zhang: Arthur parameters and cuspidal automorphic modules of classical groups. Annals of Mathematics (2) 191 (2020), no. 3, 739-827.
With Baiying Liu and Bin Xu: A reciprocal branching problem for automorphic representations and global Vogan packets. J. Reine Angew. Math. 765 (2020), 249–277.
References
External links
1958 births
Living people
20th-century Chinese mathematicians
21st-century American mathematicians
Date of birth missing (living people)
East China Normal University alumni
Educators from Wenzhou
Fellows of the American Mathematical Society
Mathematicians from Zhejiang
Number theorists
Ohio State University College of Arts and Sciences alumni
Place of birth missing (living people)
University of Minnesota faculty
Zhejiang Normal University alumni | Dihua Jiang | [
"Mathematics"
] | 825 | [
"Number theorists",
"Number theory"
] |
63,243,147 | https://en.wikipedia.org/wiki/BRL-37344 | BRL-37344 is a drug which acts as a selective agonist of the β3 adrenergic receptor, which has been investigated for various biomedical research applications but never developed for clinical use.
References
Substituted amphetamines | BRL-37344 | [
"Chemistry"
] | 50 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
63,245,755 | https://en.wikipedia.org/wiki/One-way%20wave%20equation | A one-way wave equation is a first-order partial differential equation describing one wave traveling in a direction defined by the vector wave velocity. It contrasts with the second-order two-way wave equation describing a standing wavefield resulting from superposition of two waves in opposite directions (using the squared scalar wave velocity). In the one-dimensional case it is also known as a transport equation, and it allows wave propagation to be calculated without the mathematical complication of solving a 2nd order differential equation. Due to the fact that in the last decades no general solution to the 3D one-way wave equation could be found, numerous approximation methods based on the 1D one-way wave equation are used for 3D seismic and other geophysical calculations, see also the section .
One-dimensional case
The scalar second-order (two-way) wave equation describing a standing wavefield can be written as:
where is the coordinate, is time, is the displacement, and is the wave velocity.
Due to the ambiguity in the direction of the wave velocity, , the equation does not contain information about the wave direction and therefore has solutions propagating in both the forward () and backward () directions. The general solution of the equation is the summation of the solutions in these two directions:
where and are the displacement amplitudes of the waves running in and direction.
When a one-way wave problem is formulated, the wave propagation direction has to be (manually) selected by keeping one of the two terms in the general solution.
Factoring the operator on the left side of the equation yields a pair of one-way wave equations, one with solutions that propagate forwards and the other with solutions that propagate backwards.
The backward- and forward-travelling waves are described respectively (for ),
The one-way wave equations can also be physically derived directly from specific acoustic impedance.
In a longitudinal plane wave, the specific impedance determines the local proportionality of pressure and particle velocity :
with = density.
The conversion of the impedance equation leads to:
A longitudinal plane wave of angular frequency has the displacement .
The pressure and the particle velocity can be expressed in terms of the displacement (: Elastic Modulus):
for the 1D case this is in full analogy to stress in mechanics: , with strain being defined as
These relations inserted into the equation above () yield:
With the local wave velocity definition (speed of sound):
directly(!) follows the 1st-order partial differential equation of the one-way wave equation:
The wave velocity can be set within this wave equation as or according to the direction of wave propagation.
For wave propagation in the direction of the unique solution is
and for wave propagation in the direction the respective solution is
There also exists a spherical one-way wave equation describing the wave propagation of a monopole sound source in spherical coordinates, i.e., in radial direction. By a modification of the radial nabla operator an inconsistency between spherical divergence and Laplace operators is solved and the resulting solution does not show Bessel functions (in contrast to the known solution of the conventional two-way approach).
Three-dimensional case
The one-way equation and solution in the three-dimensional case was assumed to be similar way as for the one-dimensional case by a mathematical decomposition (factorization) of a 2nd order differential equation. In fact, the 3D One-way wave equation can be derived from first principles: a) derivation from impedance theorem and b) derivation from a tensorial impulse flow equilibrium in a field point. It is also possible to derive the vectorial two-way wave operator from synthesis of two one-way wave operators (using a combined field variable). This approach shows that the two-way wave equation or two-way wave operator can be used for the specific condition ∇c=0, i.e. for homogeneous and anisotropic medium, whereas the one-way wave equation resp. one-way wave operator is also valid in inhomogeneous media.
Inhomogeneous media
For inhomogeneous media with location-dependent elasticity module , density and wave velocity an analytical solution of the one-way wave equation can be derived by introduction of a new field variable.
Further mechanical and electromagnetic waves
The method of PDE factorization can also be transferred to other 2nd or 4th order wave equations, e.g. transversal, and string, Moens/Korteweg, bending, and electromagnetic wave equations and electromagnetic waves.
See also
References
Geophysics
Wave mechanics
Acoustics
Sound
Continuum mechanics | One-way wave equation | [
"Physics"
] | 930 | [
"Physical phenomena",
"Applied and interdisciplinary physics",
"Continuum mechanics",
"Classical mechanics",
"Acoustics",
"Waves",
"Wave mechanics",
"Geophysics"
] |
63,248,124 | https://en.wikipedia.org/wiki/Claudina%20Rodrigues-Pousada | Claudina Rodrigues-Pousada was a Portuguese researcher in biochemistry. She was a research student at the Gulbenkian Institute of Science until 1973 and at the Institute of Physico-Chemical Biology (IBPC), Paris from 1973 to 1979 and Paris Diderot University. In 1979 she completed her PhD studies and in 1976 was employed by the Calouste Gulbenkian Foundation as an adjoint researcher at the Gulbenkian Institute of Science; in 1984 she was a senior researcher until 31 December 1999. In 2000 she moved to the Institute of Technology Chemical Biology as an invited full professor, where she launched the Genomics and Stress laboratory. She worked with yeast to examine how the fungi reacts to environmental stressors, such as Iron, Arsenic, and Nitric oxide, and thus how these stressors regulate cellular homeostasis.
Early life and education
Rodrigues-Pousada was born in 1941 in Tadim, Portugal, and died on 2 March 2021 in Lisbon.
She graduated from the University of Porto with a degree in Pharmacy in 1968, though she started in Mathematics. She was awarded her PhD in Biochemistry from the Institute of Physical and Chemical Biology.
Awards and honors
In 1994 she was elected as a member of EMBO.
In 2009 Dr. Rodrigues-Pousada was awarded her university's "Figure of the Year" award.
In 2010 she received the Seeds of Science award.
In 2011 she was elected a Fellow of the American Association for the Advancement of Science.
References
External links
Her lab's ResearchGate profile
French biochemists
Portuguese biochemists
Women biochemists
21st-century chemists
French women chemists
French women biologists
21st-century biologists
1941 births
Fellows of the American Association for the Advancement of Science
Academic staff of Paris Diderot University
Living people
University of Porto alumni | Claudina Rodrigues-Pousada | [
"Chemistry"
] | 375 | [
"Biochemists",
"Women biochemists"
] |
53,459,481 | https://en.wikipedia.org/wiki/Alexander%20Butlerov%20Chemistry%20Institute | Alexander Butlerov Chemistry Institute (former name Chemical Faculty of Kazan State University) — structural unit of Kazan (Volga region) Federal University, carries out research, development and academic activity in the area of basic and applied chemistry.
History
The experience in chemistry research in Kazan University dates back to its foundation: the first chemical laboratories were opened at the departments of «Chemistry and metallurgy» and «Technology and science related to trade and factories» nearly after the University foundation.
Scientific works of chemists – Karl K. Klaus, Nikolay N. Zinin, Alexander M. Butlerov, Vladimir V. Markovnikov, Alexander M. Zaitsev, Eugeny E. Wagner, Alexander E. Arbuzov, Boris A. Arbuzov, Arcady N. Pudovik, Vladimir S. Abramov. – laid the foundation of Kazan School of Chemistry. In 1933 as a result of reorganization of Soviet Universities, Faculty of Chemistry in Kazan University was opened. On April 21, 2003 according to the decision of the Academic Council of Kazan State University the Chemistry Institute named after Butlerov was established by merging of Research Institute named after A.M. Butlerov and Chemical Faculty of Kazan University. Scientists worked at the Chemical Institute, left a deep trace in the history of science. Butlerov formulated the Theory of chemical structure in 1858. 1841 is famous for development of methods for industrial production of synthetic aniline by Zinin. In 1844 Klaus discovered and studied chemical element ruthenium – the single element that was discovered in Russia. Markovnikov has discovered the rule of regioselective addition of acid and water to multiple bonds, on the contrary – Zaitsev – the cleavage of the molecules of acids and water with the formation of unsaturated compounds. Arbuzov, Arbuzov, Pudovik, and Abramov are also widely known in organic and organoelement chemistry.
Deans
Feoktist I. Bogoyavlenskiy (1933–1935)
Vasiliy V. Evlampiev (1935–1939)
Faizi F. Faizyllin (1958–1960)
Boris A. Arbuzov (1941–1950)
Arkadiy N. Pudovik (1950–1958)
Faizi F. Faizyllin (1958–1960)
Vera F. Toropova (1960–1965)
Alexander I. Kostromin (1965–1968)
Alexander I. Konovalov (1968–1972)
Irina V. Konovalova (1972–1987)
Galina A. Chmutova (1987–1992)
Nikolai A. Ulakhovich (1992–2000)
Vladimir I. Galkin (since 2000– until present)
Structure of the institute
Departments
Department of Analytical Chemistry
Department of High Molecular and Organoelement Compounds
Department of Inorganic Chemistry
Department of Organic Chemistry
Department of Physical Chemistry
Department of Chemical Education
Department of Environmental Chemistry
Department of Applied Chemistry
Department of Stereochemistry
Divisions
Division for Analytical Chemistry
Division for Inorganic Chemistry and Coordination chemistry
Division for Organic Chemistry
Division for Physical Chemistry
Division for Organoelement Compounds
Division for Stereochemistry
Division for Applied Chemistry
Division for Environmental Chemistry
Areas of research activity
Department of Analytical Chemistry
Division of analytical chemistry and laboratory of bio-electrochemical biosensor research function in this department. The division conducts research in the area of methods of electrochemical analysis using chemically modified electrodes and biosensors. The head of the department is Professor Gennady A. Evtyugin, doctor of Science in chemistry.
The Department conducts research in the following fields:
development of chemically modified electrodes for determining oxidation of organic compounds;
design of enzyme and DNA sensors for determination of biologically significant compounds – toxins, metabolites, pesticides;
immunochemical analysis;
employing of the new methods of coulometric and voltammetric determination of antioxidant – vitamins, food additives, drugs and group estimation of food products and other complex objects on the content of these compounds;
potentiometric sensors based on macrocyclic receptors for group and individual determination of inorganic and organic ions;
determining of DNA damage and creation of hybrid materials by inclusion of DNA and metal nanoparticles;
synthesis and characteristics of various organophosphorus compounds – phosphine oxides, amino phosphonates, phosphabetains which are applied in the purification of membrane technologies and selective concentration of metal ions, as well as a part of ion-selective electrodes.
The department maintains contact with many academic institutes and leading universities in Russia and abroad: Moscow State University, Kazan National Research University, Comenius University (Slovakia), University of Rome Tor Vergata (Italy). Postgraduate students and young staff of the department regularly participate in traineeship and international and domestic research projects provided by the RFBR, Russian Ministry of Education and Science and academic exchange programs. Staff of the department are actively participate in preparation and releasing of collective monographs "Problems of Analytical Chemistry" (published by "Science") series, reflecting their own experience in solving analytical problems in related fields, such as medicine and pharmacy.
Department of High Molecular and Organoelement Compounds
Subject of research: synthesis of organophosphorous and organoelement compounds, study of their spatial and electronic structure, intramolecular electronic interactions, reaction capacity and mechanism of reactions. Arkady N. Pudovik corresponding member of Russian Academy of Science worked at this department since its opening (1948) until his death (February 2006) he was the founder of the department of High Molecular and Organoelement Compounds and held the position of Head of department until 1987. Current head of the Department – Corresponding Member of the Academy of Sciences of the Republic of Tatarstan, Professor Vladimir I. Galkin, doctor of Science in chemistry.
The Department conducts research in the following fields:
theoretical and experimental study of relationship of structure and reaction capacity of phosphorus compounds of different coordination and other derivatives of intransitive elements; development of effective methods for synthesis of new substances;
receive and study of a new generation of bioactive, complexable, extraction, ionophoric, membrane transport and other practically useful substances on the basis of polyfunctional compounds of phosphorus;
directed synthesis of physiologically active substances for human and veterinary medicine based on biomimetic approach;
study of stereoselective processes involving organic, organoelement and coordination compounds;
use of metal complex compounds for chemo- and regioselective catalytic and stoichiometric functionalization of organic compounds that do not exhibit reactivity and / or selectivity hydrophosphoryl compounds in conditions of classical synthesis of organophosphorus compounds.
Department of Inorganic Chemistry
Department trains specialist in the areas of inorganic and coordination chemistry, provides courses on disciplines “General chemistry” and “Inorganic chemistry” for chemical, biological, geographical, geological, environmental and physical faculties. Within specialization “Inorganic chemistry” lectures on chemistry of complex compounds, synthesis of inorganic compounds, theory of solutions, optical and electrochemical methods of research of balance in solutions magnetochemistry and radio frequency spectroscopy of coordination compounds, balance in heterogeneous inorganic systems, theory of symmetry in coordination chemistry, supramolecular inorganic chemistry and inorganic chemistry clusters. In addition to the general course of inorganic chemistry, chemists of the faculty have courses in metrology, basics of bioinorganic chemistry, anthropogenic systems and environmental risks, environmental chemistry, computers in chemical calculations and many others. Head of the Department – Professor Rustem R. Amirov, doctor of Science in chemistry.
The department develops research work. The main aim of research implemented – development of new approaches to study of composition, stability structure of coordination metal compounds in various condensed mediums, kinetics and mechanisms of fast reactions of substitution and synthesis of compounds with desired properties. Thermodynamics of formation reactions and structure of coordination metal compounds with various organic ligands, including bioactive ligands has been studied. Regularities of solvation reactions ligand, proton and electron exchange in solutions of coordination compounds were set. On the grounds of basic studies a number of compounds with high anti-tumor activity were synthesized.
The Department conducts research in the following fields:
study of complex formation in supramolecular systems – organized ensembles surfactants and macrocyclic ligands;
study of coordination compounds of iron (III) and manganese (II) for magnetic resonance imaging;
obtaining new types of hybrid organic-inorganic functional materials based on nanoscale hyperbranched structures.
Results of these studies are of basic value in the area of coordination chemistry, bioinorganic chemistry, chemistry of nanomaterials, pharmaceutical chemistry. Proposed model and physio-chemical basis of self-assembly of nanoscale of hyperbranched polymers, set new approaches to understanding the mechanisms of gene transfection and targeted drug delivery.
Department of Organic Chemistry
The Department works at the intersection of organic chemistry (chemistry of natural products, chemistry of macrocyclic compounds, chemistry of elementorganic compounds), supramolecular chemistry (solution and self-process chemistry) and molecular biology. The head of the Department is Professor Igor S. Antipin, a corresponding member of the Russian Academy of Science, Doctor of Chemistry. The Department conducts research in the following fields:
creating non-viral transfection agents, developing preparations for biotechnological production and gene therapy;
creating new programmable materials based on hybrid nanoparticles for medicine and biochemistry;
developing direct synthesis methods, studying structure and properties of new sulphur derivatives of five-membered oxygen- and nitrogen-containing heterocycles;
searching for chemo-, region- and stereo-selective thiating and aminating reactions with the view to create new antimicrobial agents based on studied heterocycles;
developing new principles of pathogenic microflora control in collaboration with biologists. New organic synthesis methods are developed here, as well.
Department of Physical Chemistry
At the present time the Department promotes various scientific fields, running the whole gamut of base branches of classical physical chemistry: thermodynamics, kinetics, electrochemistry, catalysis, sorption processes. As the subjects of research, organic compounds unite all the aforesaid research areas. Over the last years staff members of the Department of Physical Chemistry made reports at conferences in many countries of the world: Canada, Poland, Republic of South Africa, Italy, Germany, Portugal, Czech Republic, USA, Ireland, Croatia, Spain, Sweden, Japan, Brazil. The head of the Department is Professor Boris N. Solomonov, Doctor of Science in Chemistry.
The Department conducts research in the following fields:
physical chemistry of supramolecular systems studying intermolecular interactions between gaseous matters and solid sorbents;
thermodynamics of the processes forming clathrates of supramolecular receptors and organic compounds;
studying thermal stability of supramolecular receptors and inclusion compounds formed of them; studying receptor properties of nanoscale layers of supramolecular receptors;
developing new methods for studying pressure effect on reactivity and thermodynamics of organic reactions;
designing new commercial catalysts for petrochemical synthesis with the help of nanotechnologies among others;
studying physical and chemical principles of protein functioning in non-aqueous media;
studying spatial and electronic structure of organic and organoelement compounds;
developing new methods of electrochemical synthesis of organic compounds;
fundamental challenges in: intermolecular interactions in organic nonelectrolyte solutions, thermodynamic phase transitions.
Department of Chemical Education
The Department was founded in 1934 in Kazan Teachers’ Institute to educate future teachers of chemistry. In November, 2011 the Department of Chemical Education became a structural unit of A. M. Butlerov Institute of Chemistry of Kazan (Volga Region) Federal University. Educational research was combined with fundamental and applied research in chemistry.
International, All-Russian and regional research-to-practice conferences on chemical education organized by the Department are of the utmost interest. The Department has received letters of gratitude from school principals for instructing students in research and methodology in their preparation for teaching practice. Today 3 Doctors of Science and 5 Doctors of Philosophy are involved in the educational and bringing-up process at the Department. Since 2010 teachers have been retrained in the field of “Teacher of Chemistry”.The head of the Department is Suria I. Gilmanshina, Doctor of Philosophy in Chemistry, Doctor of Science in Education.
The Department conducts research in the following fields:
thio-phosphorylated derivatives of resorcinols and calixarenes;
studying thio-phosphorylated unsaturated compounds using petrochemical and wood-chemical feedstock;
generation and theoretical study of phosphabetains and their derivatives (phosphonium salts, carboxyl-containing metal complexes);
searching for liquid growth-boosting fertilizer compounds based on microelements.
Teaching process
The following majors are currently offered to students:
04.03.01 Chemistry, Bachelor's degree program;
04.05.01 Fundamental and Applied Chemistry, Specialist Degree program;
04.04.01 Chemistry, Master's degree program;
44.03.01 Pedagogical Education, Bachelor's degree program.
The following master's degree programs are offered by the Institute in the academic year 2015–2016:
“Chemoinformatics and Molecular Simulation”;
“Chemistry of Supramolecular Nano- and Biosystems”;
“Methods of Analytical Chemistry”;
“Physical-Chemical Methods in Chemistry”;
“Petrochemistry and Catalysis”.
Total number of students taking Bachelor, Specialist and master's degree programs is 472 (as of January, 2016).Departments of the Institute of Chemistry educate postgraduates in the following majors:
02.00.01 – Inorganic Chemistry;
02.00.02 – Analytical Chemistry;
02.00.03 – Organic Chemistry;
02.00.04 – Physical Chemistry;
02.00.08 – Chemistry of Organoelement Compounds.
There are two dissertation councils functioning in the Institute of Chemistry for thesis defence in chemical sciences:
Д 212.081.03 under the Federal State Autonomous Institution of Higher Education “Kazan (Volga Region) Federal University”; majors allowed for defence:
02.00.01 – Inorganic Chemistry;
02.00.08 – Chemistry of Organoelement Compounds;
Chairman of the Council is Professor Vladimir I. Galkin, Doctor of Chemistry;
Д 212.081.30 under the Federal State Autonomous Institution of Higher Education “Kazan (Volga Region) Federal University”; majors allowed for defence:
02.00.02 – Analytical Chemistry;
02.00.03 – Organic Chemistry;
Chairman of the Council is Professor Igor S. Antipin, Doctor of Chemistry.
Institute infrastructure
The main building of the Institute is located at the intersection of Kremlyovskaya and Lobachevskaya streets. This four-story building built in 1953 in the style of Soviet neoclassicism under the guidance of architect A.G. Bikchentaev. The building of the museum of Kazan chemical school is located in the campus of the main university building, built in the 1830s in a classical style under the guidance of architect M.P. Corinfskiy.
In 2015 construction of a large laboratory building in the campus of Alexander Butlerov Institute of Chemistry was finished. The 7-storey building housed classrooms and laboratories of departments of Alexander Butlerov Institute of Chemistry, Institute of Geology and Petroleum Technologies, Institute of Physics. The building was constructed with the support of the President of Tatarstan R.N. Minnikhanov and PSC "TAIF".
Museum of Kazan School of Chemistry
The museum is located in a small two-storey building where laboratory of physics (on the first floor) and chemical laboratory (on the second floor) was designed. It was the first chemical laboratory of Kazan University. The first professor was N.N. Zinin, who studied abroad and learned new method of teaching chemistry and began to apply it in Kazan University. This method combined practical and lecture classes that is still familiar to students.
There are no usual stalls and stands in the museum. It is a memorial laboratory of the 19th century which includes Butlerov's lecture room, a library, the laboratory itself, a hall for exhibiting chemical preparations and laboratory equipment of 19–20th centuries, and the study of the head of the laboratory (Butlerov's study).
Nowadays in the main hall of the museum lectures and seminars and defence of master's and doctoral theses are conducted. In the side rooms you may observe modern laboratories.
Interesting facts
Alexander Butlerov Institute of Chemistry trains students for school chemical Olympiads of the Republic of Tatarstan and the Russian Federation. At various times, professors of the Institute of Chemistry headed Russian teams at International School Chemistry Olympiad among them were Andrey N. Vedernikov, Arkady I. Kuramshin and Igor A. Sedov;
The old building of the Alexander Butlerov Institute of Chemistry since it was built in 1953, was not only a laboratory building of chemical faculty of Kazan University, at different times, it also placed historical-philological faculty of Kazan University, military department, some rooms were used as a hostel for young teachers and graduate students of the University.
References
Kazan Federal University
Research institutes in Russia
Research institutes in the Soviet Union
Chemical research institutes
Research institutes established in 1941
1941 establishments in the Soviet Union | Alexander Butlerov Chemistry Institute | [
"Chemistry"
] | 3,587 | [
"Chemical research institutes"
] |
53,464,494 | https://en.wikipedia.org/wiki/Chronocinematograph | Chronocinematograph is an astronomical instrument consisting of a film camera, chronometer and chronograph. The device records images using a more precise timetable for observing an eclipse. It was invented in 1927 by a Polish astronomer, mathematician and geodesist Tadeusz Banachiewicz for observing total solar eclipses. During the same year, Banachiewcz used his device for solar observations in Lapland (Sweden), then in USA (1932) and Greece, Japan and Siberia (1936).
The invention enhanced the precision for determining the time of an eclipse, due to more precisely timed photos of Baily's beads, and quantifying the duration of totality. This could not have been observed as closely as before due to the brightness of the sun.
References
Astronomical instruments | Chronocinematograph | [
"Astronomy"
] | 166 | [
"Astronomical instruments"
] |
53,464,560 | https://en.wikipedia.org/wiki/Cameron%20Prize%20for%20Therapeutics%20of%20the%20University%20of%20Edinburgh | The Cameron Prize for Therapeutics of the University of Edinburgh is awarded by the College of Medicine and Veterinary Medicine to a person who has made any highly important and valuable addition to practical therapeutics in the previous five years. The prize, which may be awarded biennially, was founded in 1878 by Andrew Robertson Cameron of Richmond, New South Wales, with a sum of £2,000. The University's senatus academicus may require the prizewinner to deliver one or more lectures or to publish an account on the addition made to practical therapeutics. A list of recipients of the prize dates back to 1879.
Cameron Prize Recipients
See also
List of medicine awards
Notes
References
British lecture series
British science and technology awards
Medical lecture series
Medicine awards
University of Edinburgh
1879 establishments in Scotland
Recurring events established in 1879 | Cameron Prize for Therapeutics of the University of Edinburgh | [
"Technology"
] | 160 | [
"Science and technology awards",
"Medicine awards"
] |
53,465,035 | https://en.wikipedia.org/wiki/Kalamos%20Island%20biological%20field%20station | The Kalamos Island biological field station is a research station located in the island Kalamos, in the Ionian Sea, in Western Greece. It is situated in the core of the inner Ionian marine protected area, site GR22220003 of the Natura 2000 network. The marine area is additionally protected under the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS).
Activities
The station is a base for year-round research activities in ecology, ecosystem management and sustainability issues such as permaculture. It was created as part of the Kalamos and Kastos sustainable development program of Terra Sylvestris, a non-governmental non profit organization that established the program in order to bring about sustainable development through rewilding in the area of the Island of Kalamos, Kastos and adjacent smaller islands and their marine environment.
The station conducts and facilitates a wide variety of research projects, ranging from biodiversity conservation to environmental justice to permaculture. The biological field station is also the base for the volunteer and internship programs of Terra Sylvestris, which enables people from all over the world to participate in the activities of Terra Sylvestris in the area and specifically the biological field station. The station is a member of the Organization of Biological Field Stations and the Global Ecovillage Network. The research station provides facilities for students as well as other visiting researchers and practitioners in the fields of ecology and biodiversity conservation to participate in or conduct projects in scientific research, ecosystem monitoring and ecosystem management.
Gallery
References
External links
Terra Sylvestris non governmental organisation
Natura 2000 sites
Biological stations
Nature conservation in Europe
Environmental research
Fisheries science
Forest research institutes
Lefkada (regional unit)
Marine conservation
Research stations
Science and technology in Greece | Kalamos Island biological field station | [
"Environmental_science"
] | 366 | [
"Environmental research"
] |
53,465,807 | https://en.wikipedia.org/wiki/Sh%202-297 | Sh 2-297 (also known as Sharpless 297) is an emission nebula in the constellation Canis Major.
The region was catalogued in 1959 in the extended seconded edition of the Sharpless catalogue. This area is part of the Canis Major OB1 Association, and is a very active area of new star formation.
Studies in 1988 found that the bright star illuminating the nebula was 8th magnitude HD 53623 / HIP 34178 with spectral class B1II/III. Later in 2004 it was shown that there was embedded a cold but massive Young Stellar Object or YSO within Sh 2-297 near the edge of one of the dark rifts. This object has been observed in the far-infrared, but it is so deeply embedded in an interstellar cloud that it is undetectable in shorter wavelength observations such as the Two Micron All Sky Survey (2MASS), leading it to be originally named "Unidentified young stellar object 1" or UYSO-1. It was further revealed that this unseen stellar source produces a carbon monoxide (CO) bipolar outflow with a total mass of solar masses, while the surrounding extended envelope weighs –. Some 96 other YSOs have been discovered to be part of Sh-297, having a mean age of one million years and range in masses between and . Many variable stars are also assigned with this nebula complex, including the three brightest: MW Ori, TT Ori and V559 Ori.
Distance is estimated between 1.0 and 1.4 kpc. (3,300–4,600 ly.), averaging 1.2 kpc. or 3,900 ly.
History of observation
This region was catalogued as part of the major clustering of reflection nebula as CMa R1 by van den Bergh in 1966. Reflection nebulas were identified on blue plates of the Palomar Sky Survey, with positive confirmation made by checking nebulosity on the red plates. It was again later catalogued as LBN 1037 or LBN 225.27-02.42
See also
IC 2177
Southern celestial hemisphere
References
Reflection nebulae
Star-forming regions
Sharpless objects
Canis Major | Sh 2-297 | [
"Astronomy"
] | 444 | [
"Canis Major",
"Constellations"
] |
53,465,841 | https://en.wikipedia.org/wiki/Apix%2C%20Florida | Apix, Florida was a former rocket testing facility created as part of Project Suntan during the Space Race, including a fake town in Palm Beach County, Florida, the primary feature of which was an alleged fertilizer plant set among the surrounding swamplands. Very little details have been revealed about the rocket testing facility.
Background and overview
Background
Starting in 1945, there was heavy research into hydrogen as a fuel source. The Air Force wanted to create a faster plane for spying than the U-2.
Overview and Alleged Location
In 1956, Pratt and Whitney along with the United States Air Force decided to buy a 10 square mile piece of land in Western Palm Beach County, and development plans included a main street called Hawthorn Road surrounded by housing plats (lots).
Apix was alleged to exist several miles west of Jupiter, near the intersection of the western terminus of West Indiantown Road and State Road 710 on the Beeline Highway. Apix never had a downtown area, post office, population, or government. Apix appeared on some contemporary maps from 1959 and 1960; one map listed "Apix" alongside location markers for the Pratt & Whitney plant, William R. Gwinn Airport, and Palm Beach Racetrack.
Security
At the time, the western part of Palm Beach County was sparsely populated. Authorities said it was a fertilizer producing town to cover up the operation so that residents would not be suspicious. The name Apix meant Air Products Inc, Experimental. There was also commercial protection to make sure that potential speculators and buyers stayed clear. Land nearby was also platted and had a census marker. Pratt & Whitney bought 9,000 acres near what would today be the J.W. Corbett Wildlife Refuge. For buyers to not know it was United Aircraft (now United Technologies) a third party had bought a ranch and gave it to the Florida Game and Fresh Water Fish Commission which then was given to the U.S. Air Force.
Testing
The project's main goal was to test liquid hydrogen as a fuel source for rockets which had been in interest of the United States government since the late 1940s. Apix was part of what was called Project Suntan that was carried out in extreme secrecy from 1956–1958. The plant could liquefy Hydrogen at approximately rate of a half a ton a day, costing $6.2 million a day ($53,580,135.23 in 2017) and would be transported in an underground pipeline to a testing facility. A second plant was built in 1959 and had a capacity of 30 tons and cost about $27 million. In February 1959 the managers had decided that transporting liquid hydrogen in the underground pipeline took too much energy and decided to close it. Instead, they decided to ship hydrogen in insulated tanks on the Beeline Highway.
Present
As of 2024, Pratt & Whitney still has an active campus on site, along with Aerojet Rocketdyne.
References
Science and technology in Florida
Palm Beach County, Florida
NASA | Apix, Florida | [
"Astronomy"
] | 601 | [
"Rocketry stubs",
"Astronomy stubs"
] |
53,466,077 | https://en.wikipedia.org/wiki/Brain%20Electrical%20Oscillation%20Signature%20Profiling | Brain Electrical Oscillation Signature Profiling (BEOSP or BEOS) is an EEG technique by which a suspect's participation in a crime is detected by eliciting electrophysiological impulses.
It is a non-invasive, scientific technique with a degree of sensitivity and a neuro-psychological method of interrogation which is also referred to as 'brain fingerprinting'.
History
The methodology was developed by Champadi Raman Mukundan (C. R. Mukundan), a Neuroscientist, former Professor & Head of Clinical Psychology at the National Institute of Mental Health and Neurosciences (Bangalore, India), while he worked as a Research Consultant to TIFAC-DFS Project on 'Normative Data for Brain Electrical Activation Profiling'.
His works are based on research that was also formerly pursued by other scientists at American universities, including J. Peter Rosenfeld, Lawrence Farwell and Emanuel Donchin.
Principle
The human brain receives millions of arrays of signals in different modalities, all through the waking periods. These signals are classified and stored in terms of their relationship perceived as function of experience and available knowledge base of an individual, as well as new relationship produced through sequential processing. The process of encoding happens primarily when the individual directly participates in an activity or experiences it.
It is considered secondary, when the information is obtained from a secondary source viz. books, conversations, hearsay etc. in which there is no primary experiential component and the brain deals mainly with conceptual aspects.
Primary encoding is deep-seated and has specific source memory in terms of time and space of occurrence of experience, as individual himself/herself has shared or participated in the experience/act/event at certain time in his/her life at a certain place.
It is found that when the brain of an individual is activated by a piece of information of an event in which he/she has taken part, the brain of the individual will respond differently from that of a person who has received the same information from secondary sources (non-experiential).
BEOSP is based on this principle, thereby intending to demonstrate that the suspect who have primary encoded information of those who have participated in the suspected events will show responses indicating firsthand (personally acquired) knowledge of the event.
Procedure
Pretest interview with the suspect in BEOSP
The suspect is acquainted with BEOSP test procedure
Informed consent is obtained
Ideally, no questions are to be asked while conducting the test; rather, the subject is simply provided with the probable events/scenarios in the aftermath of which, the results are analyzed to verify if the brain produces any experiential knowledge, which is essentially the recognition of events disclosed. This way, all fundamental rights are protected, as neither there are no questions that are being asked or any answers reciprocated.
Applications
University of Pennsylvania conducted a research along with the Brigham & Women's Hospital (Boston, Massachusetts), Children's Hospital Boston & the University Hospital of Freiburg, Germany which determined that Gamma Oscillations in the brain could help distinguish false memories from the real ones. Their analysis concluded that in the retrieval of truthful memories, as compared to false, human brain creates an extremely distinct pattern of gamma oscillations, indicating a recognition of context based information associated with a prior experience.
Criticism
India’s Novel Use of Brain Scans in Courts Is Debated as featured on The New York Times
India’s Judges Overrule Scientists on ‘Guilty Brain’ Tech as discussed over Wired (magazine)
See also
Polygraph
Criminal profiling
External links
Forensic psychology
Physiological instruments
Forensic equipment
Neurophysiology
Psychology controversies
Lie detection
Fringe science | Brain Electrical Oscillation Signature Profiling | [
"Technology",
"Engineering"
] | 749 | [
"Physiological instruments",
"Measuring instruments"
] |
53,466,285 | https://en.wikipedia.org/wiki/NGC%207552 | NGC 7552 (also known as IC 5294) is a barred spiral galaxy in the constellation Grus. It is at a distance of roughly 60 million light years from Earth, which, given its apparent dimensions, means that NGC 7552 is about 75,000 light years across. It forms with three other spiral galaxies the Grus Quartet.
Observation history
NGC 7552 was discovered on 7 July 1826 by James Dunlop. John Herschel added it to the General Catalogue of Nebulae and Clusters as number 3977. However, Lewis Swift reported the galaxy independently on 22 October 1897, at right ascention 9 arcseconds off the location of the galaxy and it was included in Index Catalogue as IC 5294.
Structure
NGC 7552 is a barred spiral galaxy, with two spiral arms forming an outer pseudo-ring. The galaxy is seen nearly face on, at an inclination of ~ 28°.
The one arm is more prominent and the less prominent arm shows no clear continuation with the bar. The bar is dusty, and four huge HII regions are detected in it. The disk features numerous scattered HII regions in an asymmetric pattern. The total infrared luminosity of the galaxy is , and thus is categorised as a luminous infrared galaxy.
The SIMBAD database lists NGC7552 as a Seyfert I Galaxy, i.e. it has a quasar-like nucleus with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, the host galaxy is clearly detectable.
Starburst ring
In 1994, Forbes et al. observed a partial starburst ring with 1 kpc radius at Br-gamma with various hot spots. They also detected a small-scale molecular bar and a large reservoir of molecular material, however, no evidence of current activity was detected at the nucleus. The ring is more than 100 parsecs wide.
The ring is brighter north of the nucleus and there is inhabited by the younger star populations. Brandl et al. detected in near- and mid-infrared nine prominent structures within the ring they identified as star clusters with stellar ages ranging between 5.5 Myr and 6.3 Myr. These clusters account for the 75% of the bolometric luminosity of the starburst ring, with total luminosity of the clusters 2.1 × 1010 L⊙.
Numerous supernova remnants have been observed in the ring. Further observations of the galaxy in radio waves showed that NGC 7552 contains three star forming rings of radii 1.0 kpc, 1.9 kpc, and 3.4 kpc as observed by the Very Large Array at 46.9 MHz and the Australia Telescope Compact Array.
Supernova
One supernova has been observed in NGC 7552: SN 2017bzc (type Ia, mag. 12.8) was discovered by Stuart Parker as part of the Backyard Observatory Supernova Search on 7 march 2017.
Galaxy group
NGC 7552 belongs in NGC 7582 group, also known as the Grus group. Other members of the group include the spiral galaxies NGC 7599, NGC 7590, and NGC 7582, which along with NGC 7552 form the Grus Quartet. A large tidal extension of HI reaches from NGC 7582 to NGC 7552, which is indicative of interactions between the group members, yet NGC 7552 does not have highly disturbed morphology.
See also
NGC 1672 - a similar-looking barred spiral galaxy
List of NGC objects (7001–7840)
References
External links
Barred spiral galaxies
Ring galaxies
Luminous infrared galaxies
Grus (constellation)
7552
IC objects
070884
291-G012
Astronomical objects discovered in 1826
Discoveries by James Dunlop
Discoveries by John Herschel
Galaxies discovered in 1826
-07-47-028
23134-4251
Seyfert galaxies | NGC 7552 | [
"Astronomy"
] | 793 | [
"Grus (constellation)",
"Constellations"
] |
53,467,456 | https://en.wikipedia.org/wiki/Peter%20T.%20Cummings | Peter T. Cummings is an Australian-American chemical engineer, currently the John R. Hall Professor of Chemical Engineering and associate dean for research for the school of engineering at Vanderbilt University. He formerly held positions at the University of Virginia and the University of Tennessee, Knoxville.
Between 1994 and 2013, Cummings was associated with the Oak Ridge National Laboratory (ORNL). He was one of the four researchers who wrote the proposal to establish ORNL's Center for Nanophase Materials Sciences Division (CNMS). From 2007 to 2013, he served as the principal scientist for the CNMS.
His research interests include statistical mechanics, computational materials engineering, and theoretical nanoscience using molecular modeling techniques such as molecular dynamics and Monte Carlo simulations.
References
1954 births
Living people
University of Melbourne alumni
University of Newcastle (Australia) alumni
Australian chemical engineers
American chemical engineers
Vanderbilt University faculty
Chemical engineering academics
Fellows of the American Physical Society | Peter T. Cummings | [
"Chemistry"
] | 183 | [
"Chemical engineering academics",
"Chemical engineers"
] |
62,331,147 | https://en.wikipedia.org/wiki/Jean-Marc%20Egly | Jean-Marc Egly (born 27 December 1945), is a French molecular biology researcher specialising in the field of transcription. Research Director at Inserm, he was also Chairman of the Scientific Council of the ARC from 2006 to 2011. He is a member of the French Academy of sciences.
Biography
Jean-Marc Egly obtained his doctorate in chemistry in 1971 and a second in biochemistry in 1976 at the Louis-Pasteur University in Strasbourg. In 1985, he became Inserm research director at the IGBMC in Strasbourg, founded by Pierre Chambon. In 1995, he was commissioned by the Secrétaire d'état à la Recherche, Elisabeth Dufourcq, to carry out a mission and prepare a report advocating the creation of the Great Sequencing of the Genome in Evry. In 2005, he was elected a member of the French Academy of sciences. He is also a member of the Scientific Council of the Parliamentary Office for the Assessment of Scientific and Technological Choices (OPECST).
Scientific contributions
Jean-Marc Egly's work focused mainly on describing the mechanisms of transcription at the level of type II RNA polymerase.
Distinctions
2002: Research Prize of the Allianz-Institut de France Foundation.
2004: Grand Prix de la recherche médicale de l'Inserm
2006: Chevalier of the Légion d'honneur
2014: Officier of the Légion d'honneur
References
1945 births
Living people
21st-century French biologists
Inserm directors
Members of the French Academy of Sciences
Molecular biologists
Officers of the Legion of Honour
University of Strasbourg alumni | Jean-Marc Egly | [
"Chemistry"
] | 323 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
62,331,378 | https://en.wikipedia.org/wiki/Markov%20constant | In number theory, specifically in Diophantine approximation theory, the Markov constant of an irrational number is the factor for which Dirichlet's approximation theorem can be improved for .
History and motivation
Certain numbers can be approximated well by certain rationals; specifically, the convergents of the continued fraction are the best approximations by rational numbers having denominators less than a certain bound. For example, the approximation is the best rational approximation among rational numbers with denominator up to 56. Also, some numbers can be approximated more readily than others. Dirichlet proved in 1840 that the least readily approximable numbers are the rational numbers, in the sense that for every irrational number there exists infinitely many rational numbers approximating it to a certain degree of accuracy that only finitely many such rational approximations exist for rational numbers. Specifically, he proved that for any number there are infinitely many pairs of relatively prime numbers such that if and only if is irrational.
51 years later, Hurwitz further improved Dirichlet's approximation theorem by a factor of , improving the right-hand side from to for irrational numbers:
The above result is best possible since the golden ratio is irrational but if we replace by any larger number in the above expression then we will only be able to find finitely many rational numbers that satisfy the inequality for .
Furthermore, he showed that among the irrational numbers, the least readily approximable numbers are those of the form where is the golden ratio, and . (These numbers are said to be equivalent to .) If we omit these numbers, just as we omitted the rational numbers in Dirichlet's theorem, then we can increase the number to 2. Again this new bound is best possible in the new setting, but this time the number , and numbers equivalent to it, limits the bound. If we don't allow those numbers then we can again increase the number on the right hand side of the inequality from 2 to /5, for which the numbers equivalent to limit the bound. The numbers generated show how well these numbers can be approximated; this can be seen as a property of the real numbers.
However, instead of considering Hurwitz's theorem (and the extensions mentioned above) as a property of the real numbers except certain special numbers, we can consider it as a property of each excluded number. Thus, the theorem can be interpreted as "numbers equivalent to , or are among the least readily approximable irrational numbers." This leads us to consider how accurately each number can be approximated by rationals - specifically, by how much can the factor in Dirichlet's approximation theorem be increased to from 1 for that specific number.
Definition
Mathematically, the Markov constant of irrational is defined as . If the set does not have an upper bound we define .
Alternatively, it can be defined as where is defined as the closest integer to .
Properties and results
Hurwitz's theorem implies that for all .
If is its continued fraction expansion then .
From the above, if then . This implies that if and only if is not bounded. In particular, if is a quadratic irrational number. In fact, the lower bound for can be strengthened to , the tightest possible.
The values of for which are families of quadratic irrationalities having the same period (but at different offsets), and the values of for these are limited to Lagrange numbers. There are uncountably many numbers for which , no two of which have the same ending; for instance, for each number where , .
If where then . In particular if then .
The set forms the Lagrange spectrum. It contains the interval where F is Freiman's constant. Hence, if then there exists irrational whose Markov constant is .
Numbers having a Markov constant less than 3
Burger et al. (2002) provides a formula for which the quadratic irrationality whose Markov constant is the nth Lagrange number:
where is the nth Markov number, and is the smallest positive integer such that .
Nicholls (1978) provides a geometric proof of this (based on circles tangent to each other), providing a method that these numbers can be systematically found.
Examples
Markov constant of two numbers
Since ,
As because the continued fraction representation of is unbounded.
Numbers αn having Markov constant less than 3
Consider ; Then . By trial and error it can be found that . Then
See also
Irrationality measure
Lagrange number
Continued fraction
Lagrange spectrum
References
Continued fractions
Diophantine approximation | Markov constant | [
"Mathematics"
] | 930 | [
"Continued fractions",
"Mathematical relations",
"Diophantine approximation",
"Approximations",
"Number theory"
] |
62,331,996 | https://en.wikipedia.org/wiki/Nikolai%20Ivanov%20%28entrepreneur%29 | Nikolai Ivanovich Ivanov (; April 8, 1836 – February 13, 1906) was a Russian businessman operating out of Tashkent, Russian Turkestan. He was known as the largest and most successful entrepreneur and commerce advisor in Tashkent, owning multiple distilleries and breweries in Tashkent and other Central Asian cities.
Early life
Born the son of a small merchant from Orenburg, Ivanov began his career in business at the age of fifteen as an errand boy. Thanks to his abilities, Ivanov rose up the ranks without graduating from school. He worked at the Yenisei gold mines, and was working independently by 1865, performing government contracts in Turkestan.
Business career
Ivanov was interested in chemical enterprises. He owned plants in Tashkent that produced artificial ice and mineral water, as well as distilleries of vodka. In 1874, Ivanov was the first person in Tashkent to set up production of beer. The reputation of his "sixth brewery" was high until the end of the 20th century owing to the high quality of his products.
Having bought the Degress estate near Tashkent, Ivanov organized winemaking events there and began to produce vintage wines. Pre-Russian Revolution wine tasters enjoyed Ivanov's wines, particularly the brand of Semilion, Sultani, Muscat and Siabchashma. Ivanov's various factories operated out of many cities in Turkestan.
Ivanov owned a company that mined "Dragomirovsky Coal", and between the years of 1882 and 1895, before the construction of the Tashkent Railway, he controlled the Tashkent postal station, Terekli Station (1.4 thousand kilometers long), the only transport station connecting Turkestan with the Russian heartland.
Ivanov was known as the largest producer of high-quality vodka in Turkestan. His factories carried out full production cycles. In 1882, Ivanov was approached by German chemist Wilhelm Pfaff with a proposal to organize santonin production in Shymkent, as the city was near the Arys river valley, where santonin could be extracted naturally from plants. Ivanov built the Savinkov-Ivanov Chemical-Pharmaceutical Plant, and heavy equipment was carried from Altona, Hamburg to Shymkent through Orenburg on camel-drawn wagons with specially designed wheels and axels. The plant started production in 1882. It is now known as Chimfarm JSC, a prominent pharmaceutical company in Kazakhstan. As the santonin was shipped to Japan, India, Germany and England, the plant became known around the world.
In Ivanov's Turkestan enterprises, owned by his firm, 2700 workers were employed. In 1881, Ivanov established the Central Asian Commercial Bank. For many decades, Ivanov was looked up to as an elder by businesspeople in Tashkent, receiving the honorary title of Commerce Advisor. He was given several awards for his success. Ivanov was also known for the fact that he donated much money to the Russian Orthodox Church for the construction and arrangement of churches, charity houses, shelters and other structures.
Family
Ivanov was married to Alexandra Petrovna Ivanova (December 14, 1845 - August 13, 1913, Tashkent). He had 3 sons - Ivan, Vasily, and Alexander, as well as a daughter, Olga Nikolaevna Ivanova. These children were the owners of the firm Heirs of Commerce Advisor N. I. Ivanov, having inherited their father's enterprises. Olga (later married to Orenburg merchant Nikifor Prokofievich Savinkov) (died October 27, 1915) was the co-owner of the santonin factory in Shymkent and the first female chemical engineer and pharmacist in Russian Turkestan.
Legacy
Ivanov's summer residence near Tashkent was transformed into a Russian Orthodox cemetery after his death. The cemetery is now known as the Botkin Cemetery for the street it is located on. It is the largest memorial, cultural and historical complex in Tashkent. Near the Temple to Alexander Nevsky on the territory of the Botkin Cemetery is Ivanov's grave.
References
Businesspeople from Tashkent
1836 births
1906 deaths
Chemical industry
Businesspeople from the Russian Empire
People from Orenburg
Businesspeople in the drink industry | Nikolai Ivanov (entrepreneur) | [
"Chemistry"
] | 886 | [
"nan"
] |
62,332,908 | https://en.wikipedia.org/wiki/Journal%20of%20Architectural%20Engineering | The Journal of Architectural Engineering is a quarterly peer-reviewed scientific journal published by the American Society of Civil Engineers covering all aspects of engineering design, planning, construction, and operation of buildings, including building systems; structural, mechanical, and electrical engineering; acoustics; environmental quality; lighting; and sustainability.
Abstracting and indexing
The journal is indexed in Ei Compendex, Emerging Sources Citation Index, ProQuest databases, Civil Engineering Database, Inspec, Scopus, and EBSCO databases.
References
External links
Civil engineering journals
American Society of Civil Engineers academic journals
Academic journals established in 1995
Architecture journals
English-language journals | Journal of Architectural Engineering | [
"Engineering"
] | 129 | [
"Civil engineering journals",
"Civil engineering"
] |
62,335,894 | https://en.wikipedia.org/wiki/Tris%28trimethylsilyl%29methane | Tris(trimethylsilyl)methane is the organosilicon compound with the formula (tms)3CH (where tms = (CH3)3Si). It is a colorless liquid that is highly soluble in hydrocarbon solvents.
Trisyl chemistry
Reaction of tris(trimethylsilyl)methane with methyl lithium gives tris(trimethylsilyl)methyllithium, called trisyllithium:
(tms)3CH + CH3Li → (tms)3CLi + CH4
Trisyllithium is useful in Petersen olefination reactions:
(tms)3CLi + R2CO → (tms)2C=CR2 + tmsOLi
Trisyllithium is also a source of the bulky trisyl ligand. Some tris(trimethylsilyl)methyl derivatives are far more stable than less substituted derivatives. For example, is a well-behaved tellurol. is a rare example of a robust organothallium(I) compound.
See also
Tris(trimethylsilyl)silane
References
Carbosilanes
Trimethylsilyl compounds | Tris(trimethylsilyl)methane | [
"Chemistry"
] | 248 | [
"Functional groups",
"Trimethylsilyl compounds"
] |
62,336,765 | https://en.wikipedia.org/wiki/Annoyance%20factor | An annoyance factor (or nuisance or irritation factor), in advertising and brand management, is a variable used to measure consumers' perception level of annoyance in an ad, then analyzed to help evaluate the ad's effectiveness. The variable can be observed or inferred and is a type that might be used in factor analyses. An annoyance effect (or nuisance or irritation effect) is a reference to the impact or result of an annoying stimulus, which can be a strategic aspect of an advertisement intended to help a message stick in the minds of consumers. References to annoyance effects have been referred to as annoyance dynamics. While the words "factor" and "effect", as used in the behavioral sciences, have different meanings, in casual vernacular, they have been used interchangeably as synonymous. A more general or umbrella term would simply be advertising annoyance.
History
Comment on advertising in 1850 associated some practices (disparagingly) with begging.
Measuring annoyance factors
The discipline of identifying and measuring annoyance in quantitative research became prevalent around 1968, an outgrowth of the quantitative revolution in social sciences that began in the 1950s. Before that, use and assessment – theoretical and applied (pre-testing, case studies, etc.) – was mostly qualitative (even simply intuitive or anecdotal); although the literature, since 1968, has been a mix of qualitative and quantitative. Identifying, testing, and evaluating annoyance factors is both cross-disciplinary and interdisciplinary. Activity includes psychology, sociology, anthropology, semiotics, economics, management science, and (since the advent of the information revolution about 1992) many fields related to information technology and engineering.
Generally, annoyance from an ad can be identified in three areas:
content
execution
placement
Annoyance in ad production and placement
Setting aside advances in technology, the interdisciplinary fields involved in production phases of broadcast media (including digital online) that deal with advertising annoyance – including film (videography), music, art, design, and copy – have remained relatively similar since the dawn of broadcasting.
Applications
An annoyance stimulus can be (a) a desired marketing strategy or (b) an unavoidable, albeit inherent mix of attributes of a marketing message to weigh and balance or minimize. Traditional annoyance stimuli might feature repetitive phrases or repetitive ads or an annoying communicator. Annoyance stimuli – whether nuanced, subtle, or overt – might involve creating an unpleasant sound, such as a bad jingle – one that consumers can't get out of their heads. In the Northeastern United States, specifically the New York and Philadelphia metropolitan areas, the Mister Softee jingle, officially titled "Jingle and Chimes", is both loved and hated. It sticks in people's heads. The New York Times characterized it as "exquisitely Pavlovian, triggering salivation or shrieking – sometimes both at once." In the same article, the New York Times asserted that "it is the textbook embodiment of an earworm: once heard, never forgotten."
Generally, broadcast and streaming advertising is annoying. Exceptions might include product placement – which avoids interruptions. Advertisers commonly try to appeal to positive emotions – and, with a careful mix of various gradations of annoyance(s), appealing to those emotions can be achieved. Nonetheless, the goal is to etch a message in the minds of consumers without turning them off. Capital outlay for the use of it can be relatively expensive for major consumer product companies and the research behind it, sophisticated.
Annoyance stimuli – visual or auditory or perceptual – can be in any combination of loudness, repetition, length On television, radio, print media, packaging, product displays, billboards, mail, telemarketing (especially robocalls), the internet – including email, and mobile devices, e.g.:
banners
pop-ups
floating ads
interstitials
prevideo (skip and no-skip)
autoplay video
skyscrapers
large rectangles
sponsored social media content
digital on-screen graphic
also direct-to-consumer ads (especially pharmaceuticals), call to action marketing, and false ads.
The annoyance stimuli of some ad campaigns might be so subtle that, initially, it is unnoticeable, but over time, highly noticeable. For instance, Folgers Coffee, which was acquired by Procter & Gamble in 1963, ran high frequency ads on TV and in print from 1965 to 1986 featuring "Mrs. Olson", portrayed by actress Virginia Christine (1920–1996). Some consumers initially perceived her messages as pleasant, but over time, annoying – as some research found. Yet, the annoyance technique was a successful brand-strengthening strategy. Under P&G, Folgers became the number one coffee brand in America. The target market of P&G's high-frequency campaign became multipronged. Consumers who infrequently watched TV were likely to see the message at least once (an effective reach strategy) – while those who binge-watched, even if annoyed, might still choose Folgers, if for no other reason, because the name is etched in their minds (an effective weight strategy). Although interruptions are annoying – whether high-frequency or long run-slots – the disruptions caused by the interruptions are most often intentional efforts to redirect the attention of viewers with the aim of sharpening their focus. Primetime TV (as of 2019) has breaks that run back-to-back 30-second ads for as long as 6-minute intervals.
Annoyance factor thresholds
When advertisers intentionally use annoyance stimuli, they strive to know annoyance thresholds (compare to anxiety thresholds) and carefully monitor them. Crossing thresholds can adversely affect brands and consumer behavior. For example, TV channel surfing – especially in eras following the emergence of remote controls, is a concern for advertisers and program producers. To mitigate viewer drift from surfing, programmers strategically place ads just moments in front of the apex of a plot device or rising action or climax or conclusion or in the midst of suspense – leaving viewers hanging. It doesn't significantly deter channel surfing, but it does lure surfers back. Strategic timing, however, is not commonly deployed in internet broadcasts. For example, a YouTube re-broadcast of CNN news might simply insert ad interruptions in random spots. Another way that major TV networks attempt to mitigate viewer drift from surfing is to synchronize ad-breaks with those of other networks so that their respective ads run at the same time; when a viewer switches to another channel during a commercial break, they will be switching to another advertisement. In some situations, the same sponsor will air an ad simultaneously on one or more of the other channels.
Advertising in premium venues or platforms (where consumers have already paid) – movie theaters, cable TV, satellite radio – are routine and generally accepted. Any associated annoyance factors, even perceptions of bait-and-switch, are dismissed by consumers as negative albeit long-standing unavoidable economic realities of the respective industries.
Email spam, universally accepted as an annoyance factor threshold breach, can be effective from a statistical perspective. However, since 1998, when unsolicited political bulk email first became widespread, legal analyst Seth Grossman pointed out (in 2004) that state and federal governments increasingly have regulated unsolicited commercial email, but political spam had almost uniformly been exempted. Grossman averred that politicians apparently did not feel a need to regulate political spam, their argument being that they would never use spam, due to the annoyance factor.
Challenges of minimizing avoidance of longer ads
For DVR-TiVo users, studies have shown that short ads, 5 seconds, are more effective than 30-second (and longer) ads – due to the annoyance factor of longer ads. The problem, however, is whether programmers can sell 5-second ads instead of 30-second (and longer) ads, with similar pricing – especially considering the challenge of consistently producing effective 5-second ads.
Annoyance factors that influence ad avoidance
Perceived intrusiveness
Perceived informativeness
Ad utilities
High-pressure advertising (hard sell, as contrasted by soft sell)
Questionable and polarized advertising, including pharmaceuticals (patent medicine, including off-label use), firearms, political campaigns, tobacco
Annoying albeit effective ads
Some ads are deliberately annoying. Some are cute or funny, but, for some, wear thin over time. "Memorable, but not always effective"
North America
Mascots
The Aflac Duck
The Band, FreeCreditScore.com
Betty White, Snickers
Dusty the Dusthole, Clark County, Nevada
Energizer Bunny
Erin Esurance
Flo, Progressive
Go-Gurt independent child, Yoplait
The King, Burger King
Foghorn Leghorn, as used by GEICO
GEICO gecko
GEICO Cavemen
HeadOn
Kia Soul Hamsters
Mayhem, Allstate
Mr. Opportunity, Honda
Mr. Six, Six Flags
Peggy, Discover Card
Poppin' Fresh, Pillsbury
Jingles
"Jingles and Chimes," Mister Softee
(audio via YouTube)
Phrases
Exhibit of an annoyance factor analysis table
Factor analysis of perceptual items and attitude measures in online advertising:
Academicians Kelli S. Burns, PhD, and Richard J. Lutz, PhD, surveyed online users in 2002. In doing so, they chose six online ad formats: (i) banners, (ii) pop-ups, (iii) floating ads, (iv) skyscrapers, (v) large rectangles, and (vi) interstitials.
To develop perceptual factors, ratings of the 15 perceptual items for all six on-line ad formats were run through principal components analysis with varimax rotation. The authors inferred – from a scree plot – a possible three-factor solution. The first three factors accounted for over 68% of the total variance. The remaining 12 reflected no more than 5% of the variance, each. The first of the seven tables in their paper, Table 1 (below), shows the loadings of the factors generated through principal component extraction and varimax rotation.
Performing arts analogy
Using annoyances as disruptive devices in advertising to help messages sink-in can be analogous to jarring devices used in performing arts. For example, in the Alvin Ailey American Dance Theater December 6, 2019, premier of Greenwood at City Center in New York, Donald Byrd (born 1949), the choreographer, described his work as "theater of disruption" "it disrupts our thinking about things, especially, in particular, things around race." The dance performance addresses a 1921 racist mob attack in Tulsa's then segregated Greenwood District, which, at the time, was one of the country's most affluent African American communities, known as "America's Black Wall Street."
See also
The following subjects may address certain aspects or fall within the scope of annoyance dynamics.
General
Ad tracking
Advertising
Advertising adstock
Advertising campaign
Advertising media selection
Advertorial
Ambient media
Audience measurement
Attack marketing
Campaign advertising
Cause marketing
Celebrity branding
Clutter
Comparative advertising
Conquesting
Content marketing
Customer engagement
Database marketing
Demographic targeting
Direct marketing
Engagement marketing
Event marketing
Frequency capping
Global advertising
Guerrilla marketing
In-flight advertising
Integrated marketing communications
Interruption science
Marketing communications
Marketing buzz
Mind share
Mobile billboard
Multichannel marketing
Music in advertising
Native advertising
Out-of-home advertising (OOH)
People meter
Perceptual mapping
Positioning
Promotional mix
Puffery
Targeted advertising
Broadcast
Bumper
Commercial skipping
Gross rating point
Radio advertisement
Skinny bundle
Television advertisement
TV-online hybrid
Over-the-top media services (OTT)
Virtual advertising
Illicit, malicious, or misleading
Browser hijacking
False advertising
Malvertising
Trick banner
Internet and mobile
Ad exchange
Ad blocking
Admail
Banner blindness
Behavioral retargeting
Clickbait (or Chumbox)
Contextual advertising
Conversion marketing
Cost per action
Cost-per-click
Cost per lead
Display advertising
Dynamic ad insertion
Freemium
Geotargeting
Mobile marketing
Mobile phone content advertising
Online advertising
Opt-in email
PPM (Pay per 1000 impressions)
Run of network
Search engine marketing
Share of voice
Surround sessions
Sticky content
Video advertising
Viewable Impression
Viral marketing
Psychology
Racial stereotyping in advertising
Sensory branding
Sex in advertising
Shock advertising
Research and criticism
Advertising research
Criticism of advertising
Notes and references
Notes
References
{{Reflist|30em|refs=
<ref name="NYTs 1981 Aug 26">
Academic and/or peer reviewed references
Business terms
Consumer behaviour
Consumer theory
Types of marketing
Advertising techniques
Marketing techniques
Promotion and marketing communications
Advertising
Television advertising
Online advertising
Digital marketing
Film and video terminology
Television terminology
Internet terminology
Audience measurement
Market research | Annoyance factor | [
"Technology",
"Biology"
] | 2,570 | [
"Computing terminology",
"Behavior",
"Internet terminology",
"Consumer behaviour",
"Human behavior"
] |
62,337,170 | https://en.wikipedia.org/wiki/Necuno | The Necuno is a phone-like mobile device exclusively manufactured in Finland. The device is designed with a focus on enhancing security and user privacy by omitting the cellular modem, which prevents its use on conventional mobile phone networks. Instead it offers VOIP via a peer-to-peer encrypted communication platform called Ciphra. Standard cellular connectivity is planned for later versions.
The Necuno is mostly open-source, apart from an isolated firmware blob without access to the main memory, used in the Wi-Fi driver for regulatory reasons. The device uses Plasma Mobile by default, but it can run a variety of open-source mobile operating systems. It also has an ethernet port.
See also
Comparison of open-source mobile phones
References
Mobile Linux
Linux-based devices
Open-source mobile phones
Peer-to-peer computing | Necuno | [
"Technology"
] | 173 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
62,338,287 | https://en.wikipedia.org/wiki/Hills%20mechanism | The Hills mechanism is a phenomenon that occurs when a binary star system is disrupted by a supermassive black hole.
Tidal forces from the black hole cause one of the stars to be captured by it, and fall into an orbit around it. The other star is thrown away from the black hole at very high speeds. The phenomenon was proposed by astronomer Jack Hills in 1988 and confirmed in 2019, when an example of such a jettisoned star was observed. This ejected star, namely S5-HVS1, an A-type main-sequence star, notable as the fastest star detected as of November 2019, has been determined to be traveling at nearly four million miles an hour (more specifically, , almost 0.6% of the speed of light) away from the galactic core of the Milky Way.
References
See also
Penrose process | Hills mechanism | [
"Astronomy"
] | 170 | [
"Stellar astronomy stubs",
"Astronomy stubs"
] |
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