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67,525,771 | https://en.wikipedia.org/wiki/Galea%20%28botany%29 | A galea is an overhanging, helmet-shaped, part of the flower that protects the reproductive parts from precipitation, wind, or unwanted visitors. The galea is composed of one or more petals or sepals that have either fused or folded together. The name is taken from the same word for a Roman soldier's helmet.
The specific epithet galeatus(-a-um), galeiformis(-e), galeritus(-a-um) or galericulatus(-a-um) can be found in nomenclature, referring to a prominent helmet-shaped feature in the organism. There are several genera that have been named to reflect this characteristic: Galeandra, Galearia and Galearis.
References
Plant morphology
Plant reproduction | Galea (botany) | [
"Biology"
] | 155 | [
"Behavior",
"Plant reproduction",
"Plants",
"Reproduction",
"Plant morphology"
] |
67,525,912 | https://en.wikipedia.org/wiki/NGC%203608 | NGC 3608 is an elliptical galaxy located in the constellation Leo. It was discovered by William Herschel on March 14, 1784.
NGC 3608 is part of the Leo II Group of galaxies, including NGC 3605 and NGC 3607. It is approximately 13.0 billion years old. There is diffuse X-ray emission coming from this galaxy and NGC 3607, which suggests that the two may be merging.
NGC 3608 has a significant population of globular clusters. The population distribution is bimodal, with "red" and "blue" populations; the blue globular clusters form a majority. The blue globular clusters have a more extended distribution throughout the galaxy. Overall, the globular clusters are aligned along an axis that is not the same as the rest of the stars, which may be further evidence of galaxy interaction with NGC 3607.
A large structure of neutral hydrogen gas known as an H I region, about 130,000 light-years (40 kpc) across, exists some twelve arcminutes (corresponding to about 230,000 light-years, or 70 kpc) away from NGC 3608. It may be associated with the galaxy.
References
External links
Leo (constellation)
3608
Elliptical galaxies
034433 | NGC 3608 | [
"Astronomy"
] | 257 | [
"Leo (constellation)",
"Constellations"
] |
67,525,955 | https://en.wikipedia.org/wiki/Stable%20massive%20particles | Stable massive particles (SMPs) are hypothetical particles that are long-lived and have appreciable mass. The precise definition varies depending on the different experimental or observational searches. SMPs may be defined as being at least as massive as electrons, and not decaying during its passage through a detector. They can be neutral or charged or carry a fractional charge, and interact with matter through gravitational force, strong force, weak force, electromagnetic force or any unknown force.
If new SMPs are ever discovered, several questions related to the origin and constituent of dark matter, and about the unification of four fundamental forces may be answered.
Collider experiments
Heavy, exotic particles interacting with matter and which can be directly detected through collider experiments are termed as stable massive particles or SMPs. More specifically a SMP is defined to be a particle that can pass through a detector without decaying and can undergo electromagnetic or strong interaction with matter. Searches for SMPs have been carried out across a spectrum of collision experiments such as lepton–hadron, hadron–hadron, and electron–positron. Although none of these experiments have detected an SMP, they have put substantial constraints on the nature of SMPs.
ATLAS Experiment
During the proton–proton collisions with center of mass energy equal to 13 TeV at the ATLAS experiment, a search for charged SMPs was carried out. In this case SMPs were defined as particles with mass significantly more than that of standard model particles, sufficient lifetime to reach the ATLAS hadronic calorimeter and with measurable electric charge while it passes through the tracking chambers.
MoEDAL experiment
The MoEDAL experiment search for, among others, highly ionizing SMPs and pseudo-SMPs.
Non-collider experiments
In the case of the non-collider experiments, SMPs are defined as sufficiently long-lived particles which exist either as relics of the big bang singularity or are the products of secondary collisions, and are beyond the range of any conceivable accelerator experiment.
References
Hypothetical elementary particles
Particle physics
Exotic matter
Hypothetical particles | Stable massive particles | [
"Physics"
] | 424 | [
"Hypothetical particles",
"Matter",
"Unsolved problems in physics",
"Particle physics",
"Exotic matter",
"Hypothetical elementary particles",
"Physics beyond the Standard Model",
"Subatomic particles"
] |
67,525,994 | https://en.wikipedia.org/wiki/Medicine%20wheel%20%28symbol%29 | The modern Medicine Wheel symbol was invented as a teaching tool in about 1972 by Charles Storm, aka Arthur C. Storm, writing under the name Hyemeyohsts Storm, in his book Seven Arrows and further expanded upon in his book Lightningbolt. It has since been used by various people to symbolize a variety of concepts, some based on Native American religions, others newly invented and of more New Age orientation. It is also a common symbol in some pan-Indian and twelve-step recovery groups.
Recent invention
Charles Storm, pen name Hyemeyohsts Storm, was the son of a German immigrant who claimed to be Cheyenne; he misappropriated and misrepresented Native American teachings and symbols from a variety of different cultures, claiming that they were Cheyenne, such as some symbolism connected to the Plains Sun dance, to create the modern Medicine Wheel symbol around 1972. Anthropologist Alice Kehoe suspects that Storm took the idea of the medicine wheel from ahkoiyu, which are little model wheels used in games, and for decoration during rites by the Cheyenne, which were talked about in George Bird Grinnell's 19th century ethnography titled The Cheyenne Indians: Their History and Lifeways.
Subsequently Vincent LaDuke (a New Age spiritual leader going by the name Sun Bear), who was of Ojibwe descent, started also using the Medicine Wheel symbol, combining the basic concept with pieces of disparate spiritual practices from various Indigenous cultures, and adding elements of new age and occult spiritualism. LaDuke self-published a newsletter and several books, and formed a group of followers that he named the Bear Tribe, of which he appointed himself the medicine chief. For a fee, his mostly wealthy and white followers attended his workshops and retreats, joined his "tribe", and could buy titles and honours that are traditionally reserved for respected elders and knowledge keepers. For these activities LaDuke was denounced and picketed by the American Indian Movement.
Storm and LaDuke have been described as "plastic medicine men". They and others who have used the medicine wheel symbol to introduce their own ideas and concepts from other cultures into what they claim are Native American and First Nations teachings have been accused by traditional Natives and activists of harming and displacing traditional teachings for financial motives.
Symbolism
While some Indigenous groups that now use a version of the modern Medicine Wheel as a symbol have syncretized it with traditional teachings from their specific Native American or First Nations culture, and these particular teachings may go back hundreds, if not thousands of years, critics assert that the pan-Indian context it is usually placed in can too easily displace the unique, traditional teachings of sovereign tribes, bands and Nations, and in some cases even replace traditional ways with new age, fraudulent ones.
New Age writers tend to centre the idea of the medicine wheel as an individualistic tool of personal development, and use a stylized version with the circle divided into coloured quadrants, with various personal qualities assigned to the colours and quadrants. This redefinition is in stark contrast to the Indigenous view of ceremony and sacred sites being rooted in the community rather than the individual.
Syncretism within the symbol
Many of the concepts introduced into the symbolism of the medicine wheel are arguably not pan-Indigenous and many are not grounded in traditional Indigenous worldviews, though many have to come to view them as such since the advent of the medicine wheel symbol. The typical medicine wheel symbol is divided into four quadrants, each with an associated set of qualities, characteristics, and concepts, with many of these coming from non-Indigenous sources and blended with New Age ideas.
The four elements is a concept adopted from the Ancient Hindu beliefs of Pancha Bhuta and Ancient Greek philosophy of Empedocles.
The concepts of the four directions is not in accordance with many Indigenous worldviews that have six directions. Moreover, Cheyenne Elders and religious leaders do not typically teach cosmology by referring to the cardinal directions, as Storm did in his book. Rather, they explain cosmology by starting with the vertical, going through the divisions starting with Otatavoom (the Blue Sky-Space) and going to Nasthoaman (the Deep Earth). Moreover, the sacred cardinal directions in Cheyenne culture are closer to Northeast, Northwest, Southeast, and Southwest, not the North, South, East, and West as described by Storm.
Though some Indigenous North American cultures, such as the Arapaho, view life as having four stages, the Anishinaabe view life as having seven stages (according to the Miikaans Teaching) and the Eastern Cree have five stages.
Though some Indigenous nations have traditional beliefs about people with a different skin colour in their sacred stories, the division of humans into four races is not traditional or universal, but is instead founded in scientific racism and the racist views of early anthropology and biology, notably Carl Linnaeus' classifications as Americanus (red), Europeanus (white), Asiaticus (yellow), and Africanus (black).
The concept of the divisions of the mind, heart/spirit, body, and soul derive from the Ancient Greeks and Christian Neoplatonists.
Some Indigenous nations divide the year into four seasons, but the Cheyenne, which Storm based his book on, have six to eight seasons. Furthermore, the Gwich'in, the Ojibwe, the Cherokee, as well as nations in Virginia and most of the Southeastern US view the year as having five seasons. Some nations of the Pacific Northwest Coast, such as the Haida, divide the year into two seasons, while the Lakota and Kiowa have four seasons of unequal length, and the Woodland Cree have six seasons.
The concept of the year as a wheel can be found in the Wicca and Modern paganism calendar known as the Wheel of the Year, which was published prior to Storm's publishing of the modern Medicine Wheel symbol and concept.
Words for things like "Mother Earth" in Cree (okâwîmâwaskiy) are believed to be a contemporary concept from pan-Indigenous or new age influences because the word does not follow proper Cree grammar, and the classifications of mineral, plant, animal, and human does not fit into many Indigenous language structures.
Not all Indigenous nations use the same sacred medicines, as yucca, mescal, and peyote are also considered core sacred medicines by some nations, kinnikinnick was used ceremonially by some cultures, in addition to the more typically cited sage, cedar, sweet grass, and tobacco. Furthermore, not all Indigenous nations use the four medicines, such as the Coast Salish who traditionally did not use tobacco, and some Métis Elders who prefer tea and jam, and sometimes a blanket, to being offered tobacco.
Storm has the colours out of order for Cheyenne teachings: East should be red instead of yellow, South should be green not red, and the four colours are white, red, green, and black. Furthermore, the Cheyenne colours are not the vivid colours used by Storm, but rather earth tones.
The association of animals, commonly listed as bison, bear, wolf, and deer, (listed as buffalo, eagle, mouse, and bear in Storm's original description) with the quadrants is an example of diluted totemism. In Cheyenne culture, which Storm claimed to base the teachings on, the animal associated with the North is the albino bison, and the dragonfly, vovetass, is associated with both the North and the South because it changes colour during the summer, from green to white.
Though some of the concepts are founded in traditional Indigenous teachings, many are not and have resulted in confusion due to misinformation.
Criticism of the medicine wheel
Maliseet (Wolastoqiyik) academic Andrea Bear Nicholas argues that the broad adoption of the medicine wheel with little critical assessment and historical understanding of its fraudulent origins has effectively and almost totally displaced the unique oral traditions of many Indigenous nations. She views the medicine wheel as another example of ongoing colonial assault against Indigenous cultures, and has criticized academia for not doing more to protect traditional Indigenous cultures.
Co-founder and former president of the American Indian Historical Society, Rupert Costo, heavily criticized Storm's book Seven Arrows in which he introduced his medicine wheel concept, stating that Storm was "vulgarizing one of the most beautiful but least known religions of Man."
The Northern Cheyenne Tribal Council officially condemned Storm's book Seven Arrows, citing numerous inaccuracies, as did Cheyenne Elders such as Joe Little Coyote. The book's publisher, Harper and Row, paid US$7,500 in reparations (intended to be "all profits presently accrued to Seven Arrows as well as all future profits earned by it.") each to the Northern and Southern Cheyenne, and reclassified the book as fiction.
In reviewing Storm's book Seven Arrows, anthropologist John H. Moore criticized the book and how Storm inaccurately portrayed Cheyenne culture, skipping over important cultural details practised by Cheyenne cultural teachers, elevating minor elements of Cheyenne religion to undeserved major significance, dismissing cultural values, getting details mixed up, and adding things.
Both Storm and LaDuke have been criticized for commercializing and distorting Indigenous spirituality, including the medicine wheel.
Indigenous activists protested and distributed flyers at a lecture given by Storm in San Francisco in February 1995, with the bold title "STOP EXPLOITING THE SACRED TRADITIONS OF AMERICAN INDIAN PEOPLE!!!", which began by saying:
The flyer distributed at Storm's San Francisco lecture was accompanied by a document titled "American Indian International Tribunal Elder’s Statement" that concluded with "Our young people are getting restless. They have said they will take care of those who are abusing our ceremonies and sacred objects in their own way."
The Colorado chapter of the American Indian Movement confronted Sun Bear during one of his $500/head weekend-long "spiritual retreat".
Lakota leader Rick Williams has criticized Sun Bear's eclectic use of combined elements from different tribes, saying it creates a dangerous spiritual imbalance. He argues that every part of different Indigenous cultures' traditions serves a specific purpose, and that mixing elements between cultures will not only lead to the purposes being distorted and lost, but can potentially endanger the practitioner.
Anthropologist Alice Keheo writes that Native medicine wheel rites, along with other Indigenous observance of the cyclical patterns in nature and life, are one of the reasons Natives are stereotyped as more spiritual than non-Natives.
Distortions of Indigenous culture, and thus identity, using things like Storm and LaDuke's medicine wheel, is criticized as 'killing off' real Indigenous cultures and displacing them by fictional Indigenous identities and cultures. The denial of agency in dismissing the concerns, wishes, and traditional cultures of Indigenous people through popularizing such works as Seven Arrows is criticized as continuing the indignity of desecrating, mocking and abusing Indigenous traditional ceremonies and spiritual practices.
Ironically, as Bear Nicholas notes, objections and criticism about the medicine wheel symbol as a dangerous and false invented tradition are now condemned by many as disrespectful to tradition.
Variations
Among users of the medicine wheel symbol, variations exist. The axes of the medicine wheel might also be rotated to be vertical. The quadrants can be rotated into a different arrangement and the order of the colours can be different, depending on the community. Meanings and associations with the colours also vary between nations. Some Anishinaabe communities add a circle in the centre, often coloured green, to represent balance. The black quadrant is often replaced with a blue quadrant in some Cree and Ojibwe communities. Métis occasionally add a circle with the Métis flag or a green circle in the centre or use the symbol of a Red River cart wheel overlaid on the medicine wheel. Some versions of the medicine wheel consist of a hoop with two perpendicular axes connected to the hoop, and half of each axes and a connected quadrant of the hoop are coloured with the centre often left uncoloured. Some Christian groups have incorporated the Christian cross into the medicine wheel in a manner similar to the Celtic cross. In addition to the variations between Indigenous nations, there are also variations used within Indigenous nations, and not all Indigenous nations have adopted the medicine wheel, so care must be taken to not generalize.
Gallery
These examples are not a definitive list of medicine wheel designs and this is not an exhaustive list of the variations that exist. Variations exist between and within Indigenous nations, and no one design represents all Indigenous nations. These are provided as examples only.
See also
Dreamcatcher
The red road
Pan-Indianism
Pretendian
References
Native American culture
First Nations culture in Canada
Symbols
Native American cultural appropriation | Medicine wheel (symbol) | [
"Mathematics"
] | 2,581 | [
"Symbols"
] |
67,526,139 | https://en.wikipedia.org/wiki/Mamadou%20Gouro%20Sidibe | Mamadou Gouro Sidibe was born in Mali. He is an IT Engineer, computer scientist, innovator, and entrepreneur. He is the founder and developer of Lenali. Lenali is a social media application like Facebook, but uses voice-based technology in local African languages. He refers to himself as a Digital inclusive entrepreneur.
Career
Sidibe studied in Russia and France. He received a PhD in computer sciences from the University of Versailles in France. He worked ten years on research and development projects that was funded by the European Commission in computer networks and multimedia.
Sidibe started his own company in 2017 and developed the Lenali. The Lenali is a voice-based social network application that works with spoken language. It was initially developed into such languages as Bambara, Soninke, Songhay, Moore, Wolof, and French. The Lengai computer application is free.
Applications that Sidibe has developed are; Lenali, Gafe, and Kunko.
Lenali is a free vocal social media application (app) developed by Sidibe in 2017. It uses voice technology in local African languages and in French. It was developed for people who do not read or write. Features are voice tutorials, profiles, posts, picture posts, get voice instructions, create a profile, comments and GPS navigation calls. According to UNSCO Mali has a literacy rate of 40%. It allows smartphone users to communication using voice technology in their local languages.
Kunko is a computer application developed by Sidibe. It uses voice interaction in local languages to report COVID-19 suspected cases to contact institutions and authorized authorities. It uses sound, photos, voice mail, video posts, and a GPS navigator.
Gafe Digital is a standard and functional literacy application.
Sidibe is listed in the African Exponent 2018, Quartz Innovators list among the top 30 African Innovators.
References
External links
Interview with Mamadou Gouro Sidibe
Lenali - Gafe
Malian engineers
Living people
Computer scientists
Computer programmers
Malian businesspeople
Malian scientists
Year of birth missing (living people)
21st-century Malian people | Mamadou Gouro Sidibe | [
"Technology"
] | 430 | [
"Computer science",
"Computer scientists"
] |
67,526,365 | https://en.wikipedia.org/wiki/Gravitational%20contact%20terms | In quantum field theory, a contact term is a radiatively induced point-like interaction.
These typically occur when the vertex for the emission of a massless particle such as a photon, a graviton, or a gluon, is proportional to (the invariant momentum of the radiated particle).
This factor cancels the of the Feynman propagator, and causes the exchange of the massless particle to produce a point-like
-function effective interaction, rather than the usual
long-range potential. A notable example occurs in the weak interactions where a W-boson radiative correction to a gluon vertex produces a term, leading to
what is known as a "penguin" interaction. The contact term then generates a correction to the full action of the theory.
Contact terms occur in gravity when there are non-minimal interactions,
, or in Brans-Dicke Theory,
.
The non-minimal couplings are quantum equivalent to an "Einstein frame," with a pure Einstein-Hilbert action,
,
owing to gravitational contact terms. These arise classically from graviton exchange interactions.
The contact terms are an essential, yet hidden, part of the action and, if they are ignored, the Feynman diagram loops in different frames yield different results. At the leading order in including the contact terms is equivalent to performing a Weyl Transformation to remove the non-minimal couplings and taking the theory to the Einstein-Hilbert form. In this sense, the Einstein-Hilbert form of the action is unique and "frame ambiguities" in loop calculations do not exist.
References
Concepts in physics | Gravitational contact terms | [
"Physics"
] | 331 | [
"nan"
] |
67,527,532 | https://en.wikipedia.org/wiki/Photonic%20crystal%20sensor | Photonic crystal sensors use photonic crystals: nanostructures composed of periodic arrangements of dielectric materials that interact with light depending on their particular structure, reflecting lights of specific wavelengths at specific angles. Any change in the periodicity or refractive index of the structure can give rise to a change in the reflected color, or the color perceived by the observer or a spectrometer. That simple principle makes them useful colorimetric intuitive sensors for different applications including, but not limited to, environmental analysis, temperature sensing, magnetic sensing, biosensing, diagnostics, food quality control, security, and mechanical sensing. Many animals in nature such as fish or beetles employ responsive photonic crystals for camouflage, signaling or to bait their prey. The variety of materials utilizable in such structures ranging from inorganic, organic as well as plasmonic metal nanoparticles makes these structures highly customizable and versatile. In the case of inorganic materials, variation of the refractive index is the most commonly exploited effect in sensing, while periodicity change is more commonly exhibited in polymer-based sensors. Besides their small size, current developments in manufacturing technologies have made them easy and cheap to fabricate on a larger scale, making them mass-producible and practical.
Types and structures
Biosensors and integrated lab-on-a-chip
As properly designed photonic crystals exhibit high sensitivity, selectivity, stability, and their electricity-free operation if needed, they have become highly researched portable biological sensors. Developments in analysis, device miniaturization, fluidic design and integration have catapulted the development of integrated photonic crystal sensors in what is known as lab-on-a-chip devices of high sensitivity, low limit of detection, faster response time and low cost. A large range of analytes of biological interest such as proteins, DNA, cancer cells, glucose and antibodies can be detected with this kind of sensors, providing fast, cheap and accurate diagnostic and health-monitoring tools that can detect concentrations as low as 15 nM. Certain chemical or biological target molecules can be integrated within the structure to provide specificity.
Chemical sensors
As chemical analytes have their own specific refractive indices, they can fill porous photonic structures, altering their effective index and consequently their color in a finger-print like manner. On the other hand, they can alter the volume of polymer-based structures, resulting in a change in the periodicity leading to a similar end effect. In ion-containing hydrogels, their selective swelling results in their specificity. Applications in gaseous and aqueous environment have been studied to detect concentrations of chemical species, solvents, vapors, ions, pH and humidity. The specificity and sensitivity can be controlled by the appropriate choice of materials and their interaction with the analytes, that can achieve even label-free sensors. The concentration of chemical species in vapor or liquid phases as well as in more complex mixtures can be determined with high confidence.
Mechanical sensors
Different mechanical signals such as pressure, strain, torsion and bending can be detected with photonic crystal sensors. Commonly, they are based on the deformation-induced change in the lattice constants in flexible materials such as elastomeric composites or colloidal crystals, causing a mechano-chromic effect as they stretch or contract.
3D photonic crystals
Synthetic opals are three dimensional photonic crystals usually made of self-assembled nanospheres of diameters on the order of hundreds of nanometers, where the high refractive index material is that of the spheres and the low-index material is air or another filler. On the other hand, inverse opals are structures where the interstitial space between the spheres is filled with another material and the spheres are consequently removed, providing a larger free volume for faster diffusion of chemical species.
Photonic crystal fibers
Photonic crystal fibers are a special types of optical fibers that has contain air holes distributed in specific patterns around a solid or hollow core. Due to their high sensitivity, inherent flexibility, and small diameters, they can be used in a variety of situations requiring high robustness and portability. Compared to traditional optical fibers, they are highly birefringent with tailorable dispersion, limited loss and endless single-mode propagation for a long range of wavelengths and have a very fast sensing response.
2D gratings and slabs
One-dimensional slabs with two dimensional order cause by selective removal of material, creating a pattern of holes or grooves in an otherwise homogeneous material is a popular photonic crystal structure used in sensing.
Fabry-Pérot mirrors
Fabry-Pérot mirrors are planar photonic crystal where the periodicity is maintained only in the z-dimension. Sputtered porous inorganic sensors, spin-coated polymer sensors and self-assembled block-copolymers are a few of the commonly used planar 1D structures.
References
Photonics
Sensors | Photonic crystal sensor | [
"Technology",
"Engineering"
] | 1,008 | [
"Sensors",
"Measuring instruments"
] |
67,527,587 | https://en.wikipedia.org/wiki/TestOps | TestOps (or test operations) refers to the discipline of managing the operational aspects of testing within the software delivery lifecycle.
Software testing is an evolving discipline that includes both functional and non-functional testing. The first mention of this is regarded in March 2019 where, Ditmir Hasani, CEO of QA Tech consultancy is thought to have coined the term. Increasingly, software testing, especially in agile development processes is shifting to become more of a continuous testing process where software developers, quality engineers, manual testers, product owners, and more are involved in the quality process. As more people have become involved in the testing process and testing projects have grown, so too has the need to advance the discipline of software testing management and to manage the software quality processes, programmers, people, systems, and tests.
TestOps helps teams scale their teams, tests, and quality processes in and effectively.
Elements of test operations (TestOps)
TestOps involves several important disciplines that can be broken down into:
Planning — Helps identify how the software is going to be tested. What are the priorities for testing? How will it be tested? Who will do the testing? In addition, the planning phase should identify the environment for the tests. Will they be run in a test environment, or in production? Production data can be valuable to identify real user flows that help prioritize test cases. The outputs include identifying the type of tests to use, the test automation tools, the timing of the testing, the ownership of the testing at different phases, and the design and outputs of the tests.
Management — Test management includes the organization and governance of the team, the tools, the test environment, and the tests themselves. Tests follow a lifecycle pattern and must be managed whether they are in stages such as draft, active, or quarantine. TestOps helps ensure that the testing processes are efficient and scalable.
Control — As teams and tests grow in number and diversity, they naturally increase complexity. Change control processes such as pull requests, approvals on merges, collaboration tools, and ownership labeling can help ensure that changes to tests are properly approved.
Insights — The data and information you derive from your test automation systems should help inform operational as well as process transformation decisions. Operational information about your testing activities includes the test results (pass/fail), release readiness criteria, failure diagnostics, team testing productivity, test stability, and more. Information that can inform process improvements includes team and individual performance data, failure type trend analysis, test coverage mapping, and risk coverage analysis.
TestOps Features
DevOps integration — TestOps exists to ensure that the product development pipeline has all the testing frameworks and tools needed. It is common for QA engineers to rely on the pipelines that IT puts together without much input. TestOps changes this by owning test activities related to DevOps, allowing QA engineers and developers to have full ownership and visibility of the development pipeline, so they can tailor it to meet their needs.
Cloud integration — Integrating tests and test runs with cloud providers
Enhanced test planning — Automation is not effective if the entire codebase has to get tested every time a line of code is changed. TestOps provides a centralized platform that makes it easier for testers and developers to plan what tests to write, as well as identify what tests to run and when.
Test lifecycle management — Automated tests follow a lifecycle including creation, evaluation, active, and quarantine or removal. The status of the test should impact how it is treated in build automation systems like CI/CD.
Test version control — Processes that help ensure that changes to tests are properly reviewed and approved through capabilities like pull requests in code.
Real-time dashboards — Real-time results and status help the test teams understand the state of software releases and the work that needs to be done to create, approve, or run more tests.
TestOps vs. DevOps
DevOps is a broader, more inclusive concept that includes software feature planning, code development, testing, deployment, configuration, monitoring, and feedback. It was an attempt to integrate some of the disconnected toolchains. Testing is included in the broader DevOps methodology.
TestOps is not simply providing additional emphasis on testing. It is focused on operational aspects of testing that are necessary to ensure that testing, whether performed in development, production, or in its own testing phase, is well planned, managed, controlled, and provides insights to enable continuous improvement.
The siloed working mindset is aimed to be removed from activities such as continuous delivery, software testing (manual and automated testing), environment setups, infrastructure and log management, and built-in security enforcement.
References
Software testing | TestOps | [
"Engineering"
] | 948 | [
"Software engineering",
"Software testing"
] |
74,679,547 | https://en.wikipedia.org/wiki/Barnard%2092 | Barnard 92 (abbreviated to B92) is a dark nebula located in the Small Sagittarius Star Cloud. It was discovered by American astronomer Edward Emerson Barnard.
B92 was initially referred to as "the black hole," given its appearance, after it was first catalogued in 1913. It was later discovered to be a dark nebula, and the title is now misleading, as the name black hole is used in modern astrophysics to describe a region of spacetime in which gravity is too strong for light to escape.
References
Stellar astronomy
Dark nebulae
Sagittarius (constellation)
Carina–Sagittarius Arm
Astronomical objects discovered in 1913
Discoveries by Edward Emerson Barnard
Barnard objects | Barnard 92 | [
"Astronomy"
] | 142 | [
"Astronomy stubs",
"Constellations",
"Nebula stubs",
"Sagittarius (constellation)",
"Astronomical sub-disciplines",
"Stellar astronomy"
] |
74,679,603 | https://en.wikipedia.org/wiki/Polynesian%20Mythology%20%28book%29 | Polynesian Mythology and Ancient Traditional History of the New Zealand Race as Furnished by Their Priests and Chiefs is an 1855 collection of Māori mythology compiled and translated by Sir George Grey, then Governor-General of New Zealand, with significant assistance from Te Rangikāheke. The English edition is a translation of Ko ngā mahinga a ngā tūpuna Māori (The Deeds of the Ancestors), published in 1854, which was an expanded version of a manuscript entitled Ko ngā mōteatea, me ngā hakirara o ngā Māori (The Traditional Chants and Songs of the Māori) originally published in New Zealand in 1853.
Compilation from primary sources
In a preface to the book, George Grey writes that he felt he was unable to effectively communicate with Māori leaders and petitioners without speaking Te Reo Māori and understanding the references and allusions made in writings. Grey writes that he felt that translators were not able to adequately explain the context of allusions in written communications and that the additional delays to speaking meant that conversation was inevitably condensed in a way that made it harder to connect with people.
By 1849, a Māori tribal leader named Te Rangikāheke was working closely with him and teaching him Te Reo Māori. Te Rangikāheke compiled manuscripts about most aspects of Māori culture, including about myths and tribal history; these formed the basis for at least a quarter of Polynesian Mythology, though Grey introduced "alterations, combinations and omissions" and "did not acknowledge his debt."
Some stories, such as the legend of Hatupatu, are considered to be the sole work of Te Rangikāheke; the legend of Hinemoa consists of Te Rangikāheke's work interwoven with portions of the version of that story that Grey obtained directly from the inhabitants of Mokoia Island. Additional manuscript pages, including the legend of Kae and part of the Māui story, came from Hēnare Mātene Te Whiwhi. Parts of the manuscript can be attributed to a wealth of other contributors, including tribal leaders and some missionaries.
The way in which Grey compiled different versions of myths from different sources created a "patchwork which does not truly represent the traditions of any particular region." Nonetheless, the versions compiled can be considered reliable as "a wide range of tribal areas is represented" and "other things being equal, an informant who was born into the pre-contact culture, may be regarded as more reliable than one who knew the unaltered culture only by hearsay. Grey's informants or recorders were often people who had experienced life in a period relatively unaffected by European contact or who had access, in the persons of their fathers, or relatives of the father's generation, to informants who had lived in the pre-European situation."
Publication history
About the time that Te Rangikāheke joined Grey's household in 1848, Grey's collection of manuscripts was destroyed by a fire; this was one factor that made him decide to put his Māori texts into print. Robert Stokes, then the proprietor of the New Zealand Spectator and a political ally of Grey, was involved in the initial typesetting of manuscript pages in early 1851. By September of 1853, printing was complete of a 432-page Māori-language manuscript bearing the name Ko nga moteatea, me nga hakirara o nga Maori (a copy exists in the Auckland Public Library that includes a 96-page supplement, 18-page index, 2 pages of errata, and a preface), and Grey gave several copies to close associates before sailing to England at the end of 1853. In London, he had an expanded version of the Māori-language manuscript, including additional legends from Te Rangikāheke's manuscripts, printed and bound by Remnant and Edmonds under the name Ko Nga Mahinga a Nga Tupuna Maori.
While Grey's earlier publications had been smaller, the English translation of Polynesian Mythology was a considerably larger publication and a commercial venture. Publisher John Murray was a well established firm and footed the production costs in exchange for half the profit. The book was aimed at a Victorian audience, with illustrations included and source material excised for reasons of length, repetitive theme, and so as not to offend that audience; modern scholarship of the legend of Hinemoa and Tutānekai look at the relationship between Tutānekai and his Takatāpui Tiki in a queer light.
Summary of myths
The Children of Heaven and Earth
Originally, there was Rangi and Papa, the heavens and the earth, and they were tightly pressed together with their children in between them without light or space. Tūmatauenga, the god of war, suggested killing Rangi and Papa so that he and his brothers might have space, but Tānemahuta, the god of forests and birds and insects, suggested that instead they should separate the heavens from the earth. All of the brothers agreed to this except for Tāwhirimātea, the god of winds and storms, but the brothers were not able to do so until finally Tānemahuta placed his head in the earth and his feet against the sky and stood up.
In revenge for these actions, Tāwhirimātea waged war against his brothers. Tangaroa, the god of the ocean, fled to the sea, but his children Tūtewehiwehi, the father of reptiles, and Ikatere, the father of fish, disagreed about where to go, and so the fish ended up in the sea and the reptiles ended up on land. Rongomātāne, the god of cultivated plants, and Haumia-tikitiki, the god of uncultivated food, took refuge hidden within Papa, so Tāwhirimātea could not find them. Finally, Tāwhirimātea fought against Tūmatauenga, but Tūmatauenga stood firm and resisted his brother. Tūmatauenga then turned against his brothers because they had not helped him, so he sought out the food from all of his brothers' domains. His children increased and were mankind.
The Legend of Māui
Māui, the son of Taranga, was born prematurely and thrown into the sea wrapped in a tress of his mother's topknot; he is found by his ancestor Tama-nui-ki-te-Rangi, who nurses him to health. After introducing himself to his mother and brothers and living with them, he came to wonder where Taranga went to during the day. After investigating, he found that she disappeared into a cave, and so in the form of a pigeon, he flew down into the cave until he found his mother lying with her husband. His father Makeatutara took him into the water to be baptized, but Makeatutara in his haste skipped over a portion of the blessings, which he knew would mean that the gods would be sure to punish by causing Māui to die.
Māui takes food to his ancestor Muri-ranga-whenua, who recognises him as her descendant and gives him her jawbone by which he might work great enchantments. The first of these was to take his brothers and ensnare the sun so that it might move more slowly and give longer days. The next of these was to haul up a great fish from the depths of the sea with his enchanted fish-hook which became the North Island; although he told his brothers not to cut into it until he had appeased the gods, they did, so the fish thrashed around and created the mountainous geography.
Wanting to know where fire came from, Māui put out all the fires in the village so he would be sent to Mahuika to collect more. After extinguishing all bar one of her flaming fingernails, Mahuika grew angry at Māui and sent fire after him to destroy him, but Māui called out to Tāwhirimātea and Whaitiri-mātakataka, who sent rains to save him. Later, Māui quarrels with his brother-in-law Irawaru and turns him into the first dog. Distraught with grief, his sister Hinauri throws herself into the sea.
Māui returned to the land of his father, where he is told that because he was baptised incorrectly, he will die. Māui set out to defeat Hinenuitepō, the goddess of the night and of death, by climbing up through her womb and out through her mouth. Māui brought with him some birds as companions and instructed them not to laugh until he was almost out of her mouth, but the water wagtail could not help but laugh, and so Hinenuitepō woke up, closed her legs together, and killed Māui. As a result, humans are mortal.
The Legend of Tāwhaki
Tāwhaki on the way back from fishing with the brothers of his wife, Hinepiripiri, when they attack him and leave him for dead. Hinepiripiri finds him and saves him, and Tāwhaki departs with his family and warriors to build a fortified village atop a mountain. First, Tāwhaki gets revenge on those who attacked him by calling down floods of waters from the heavens. Next, Tāwhaki seeks revenge on the Ponaturi who had killed his father and imprisoned his mother, Urutonga. The Ponaturi live under the sea during the day and on the land at night, so Urutonga has Tāwhaki and his brother Karihi block up the windows to their house so that the Ponaturi will be tricked into staying above the sea after dawn, at which point the sun's rays can destroy them.
Having heard of his deeds and his beauty, Tangotango comes down from the heavens to see Tāwhaki and sleep with him; Tangotango bears him a daughter, but is offended by Tāwhaki and so returns to the heavens. Tāwhaki and Karihi set off for the heavens to find them again and find Matakerepō, their blind ancestor, counting taro roots. At first they trick her by taking the roots when she is not looking, but then Tāwhaki restores her sight to her, and she gives the brothers information about how they can ascend to the heavens by climbing hanging vines. Karihi tries first, but grabs a loose vine and very nearly dies, but Tāwhaki is able to climb a strong vine and reach the heavens. Once there, he disguises himself as an old slave and performs wonders until he reveals himself to his wife and daughter.
The Legend of Rupe
Hinauri, having thrown herself into the sea after Māui turned her husband into a dog, washes ashore at Wairarawa and is found by two brothers. Māuimua, also called Rupe, was unable to find her, so he journeyed to the tenth heaven and consulted with his ancestor Rehua, who directed him to Motutapu island, where Hinauri had been taken as wife to the superior chief Tinirau. Rupe arrives in the form of a pigeon just as Hinauri is about to give birth, and he takes her and her baby up to the heavens with him, but as they fly the placenta is accidentally dropped and eaten by a shark. Rupe and Hinauri live with Rehua in the heavens.
The Legend of Kae’s Theft of the Whale
Tinirau brings the magician Kae to his village to perform enchantments for his newborn son Tūhuruhuru. Kae arranges to be taken home on Tinirau's pet whale Tutunui, and once he reaches his village, he kills Tutunui and his village butcher and eat it. Tinirau and his wife smell the cooking whale over the sea and know what has happened, and while they want revenge, they know that a group of warriors arriving at Kae's village will be seen as a threat. Instead, a canoe of forty women go to Kae's village so as not to arouse suspicion. They have been told that they will recognise Kae by his overlapping teeth, so when they arrive they perform tricks to get everybody to laugh. Once they have found Kae, they perform enchantments to make everybody in Kae's village to sleep, and then they take Kae back to Tinirau, where he is slain.
The Legend of Tūwhakararo
Tūhuruhuru has many children, including Tūwhakararo and Mairatea. After her marriage, Tūwhakararo goes to visit Mairatea at the Āti Hāpai; a young woman there takes a liking to him, which angers the man she has been courting, and so Tūwhakararo is killed and eaten. Whakataupōtiki hears of this and takes warriors to get revenge, which he is able to do by disguising himself with charcoal and cutting his hair.
The Legend of Rātā
Rātā, the grandson of Tāwhaki, sets out to avenge the death of his father Wahieroa who was slain shortly after Rātā's birth. Rātā finds a man who tells him of Matuku-takotako, who killed his father and who rises from the earth every new moon. Rātā waits for the new moon and is able to kill Matuku as he washes his hair but is told that he will need to seek elsewhere to find Wahieroa's bones.
Rātā at first struggles to carve a canoe as spirits repair and regrow the tree he has felled to do so, but eventually the spirits help him and he takes 140 warriors with him to seek out the Ponaturi who have been using Wahieroa's bones to beat out incantations. Rātā learns the incantation and then slays the Ponaturi present and takes Wahieroa's bones. A thousand Ponaturi follow Rātā and his warriors back to their home and engage in a battle; at first 60 of the warriors are slain, but Rātā chants the incantation he learned and the warriors are returned to life.
Rātā takes Tongarautawhiri as a wife and their son is Tūwhakararo. Tūwhakararo takes Apakura as a wife, and their child is Whakatau, who is born when the god Rongotakawiu shapes Apakura's discarded apron into life. Whakatau is born in the sea, but eventually Apakura catches him flying a kite on the seashore, and Whakatau comes to live on land.
In an alternative, different version of the legend of the death of Tūwhakararo, Whakatau is approached for help by Hine-i-te-iwaiwa. He takes six warriors and goes to avenge Tūwhakararo, which he does by first goading the best warriors of the enemy to attack him and kills them one by one and then by sneaking into the house and collapsing it upon everybody.
The Legend of Toitehuatahi and Tamatekapua
Uenuku witnesses a dog owned by Houmaitawhiti and his sons Tamatekapua and Whakatūria eating a discarded bandage of his; in retaliation, Uenuku eats the dog. When Tamatekapua and Whakatūria come looking for the dog, they hear it barking from within Uenuku, so they steal pōporo fruit from his village as retaliation. When the villagers discover that their pōporo trees no longer have fruit on them, they lie in wait to find the people stealing from them; Tamatekapua manages to escape, but Whakatūria is caught and hung up in the longhouse to slowly die from the smoke. Tamatekapua visits his brother and at his suggestion, Whakatūria is able to escape by insulting the dancing of his captors and asking to demonstrate better dances. The war continues and Houmaitawhiti and Whakatūria are killed, but Tamatekapua survives.
The Legend of Poutini and Whaiapu
Ngāhoe is driven from Hawaiki by Hine-tū-a-hōanga and finds the island Aotearoa; he finds that it is full of Pounamu, and returns to Hawaiki to bring news of that. In Hawaiki there is much war, so a group of people choose to leave, and a group of large canoes are constructed to make the voyage.
The Voyage to New Zealand
Tamatekapua realises that his canoe, the Arawa, has no priest aboard, so tricks Ngātoroirangi and his wife Kearoa aboard and sets sail. Tama also steals away Whakaotirangi, the wife of Ruaeo; Roa' changes the evening stars and morning stars in response. On the voyage, Tama sleeps with Kearoa, and in anger Ngātoro calls up a whirlpool, leading to the loss of many provisions and some people, before he takes mercy and calms the seas again. Eventually, the canoe arrives at Whangaparāoa and discovers the coast full of red-flowered pōhutukawa and that they have landed near the Tainui.
The Tainui makes it to the small port of Kawhia, and the Arawa makes it to Maketu, where Ruaeo has already arrived. Rua' pulls the Arawa ashore with the 140 men that came with him, and he reconnects with his wife. Whakaotirangi mentions Rua' to Tama, who starts beating her, so she leaves with Rua'. Rua' challenges Tama to a one-on-one fight and beats him, and departs with his men but not with Whakataotirangi. They continue to travel and name places after events that occurred there.
Īhenga claims the land around Lake Rotorua by trickery. Ngātoro climbs Mount Tongariro, but struggles to reach the top through the snow, so he prays to the gods of Hawaiki to send fire to him and they turn the mountain into a volcano. Raumati hears that the Arawa is laid up at Maketu, and so goes with his men to burn it; though some consider maintaining peace, as it was war that drove them out of Hawaiki in the first place, they decide to wage war against Raumati.
The Curse of Manaia
In Hawaiki, Manaia holds a large ceremony to remove tapu; his wife Kuiwai does not heat her oven hot enough and the food for after the ceremony is undercooked. Manaia beats Kuiwai for that, and curses her brother Ngātoroirangi saying that if she does so again, he would serve the flesh of her brother the same way. Kuiwai sends her daughter to New Zealand to warn Ngātoro before the winds can bring the curse to him; her daughter and her companions make their way to New Zealand and find Ngātoro, who cleanses himself of the curse, curses Manaia in return, and builds a new canoe and sail to Hawaiki. Once there, the men cover themselves in blood from beating their own noses and pretend to be corpses as if the curse has been made true, and then wage war on Manaia's village. Manaia manages to escape the slaughter, and eventually brings a host of warriors to attack Ngātoro at his fortified village on the island Motiti in the Bay of Plenty. Ngātoro convinces Manaia and his warriors to anchor off the shore and to fight in the morning, and then calls for winds and storms. Tāwhirimātea hearkens to the calls, and the host of Manaia are destroyed overnight.
The Legend of Hatupatu and His Brothers
Hatupatu's brothers Hānui, Hāroa, and Karika spend much time trapping birds, but never share the good food with him, so he steals into the storehouse and eats the preserved birds, covering his tracks by making enough trails and giving himself some light injuries and pretending a war party stole the birds. He is successful in this for a time, until his brothers suspect him and lie in wait to catch him, whereupon they kill him. Their parents, suspecting Hatupatu's brothers of killing him, send a spirit to find him and resurrect him.
Hatupatu is taken by a woman named Kurangaituku who spears birds with nothing but her lips and who eats nothing but raw food. He steals her riches and runs away with Kurangaituku in pursuit; he escapes when he jumps over the hot springs at Rotorua and she wades through them and is burned.
Hatupatu returns home to his parents, who shelter him in their storage cave and give him the best food. His brothers notice their food is getting worse, and so when they find Hatupatu again they try to kill him once more. Their father tells them to direct their anger better, and to get revenge on Raumati for destroying the Arawa.
The brothers head for Maketu; each of the elder brothers has three hundred forty soldiers at their command but Hatupatu has none, so he makes a band of warriors out of roots and plants and dresses him in his cloaks. Hatupatu gives a number of speeches to his mock warriors, each in a different garb, to convey the impression of being a number of war chiefs. Hatupatu's brothers' men are driven back in disarray until Hatupatu breaks the enemy's will by striking down a chief in single combat, at which point his men are able to strike down their enemies and Hatupatu is able to find and kill Raumati. The warriors cook the bodies of their enemies and devour them, and they smoke their heads to preserve them. Hatupatu's father, impressed by Hatupatu's killing of Raumati, elevates him above his brothers.
Legend of the Emigration of Turi
Uenuku kills and eats Turi's son, and so Turi gets revenge by doing the same to Uenuku. One evening, Rongorongo, Turi's wife, hears Uenuku singing in his house and ascertains that he intends to kill Turi, and so he gets a canoe named Aotea from his father in law.
Kupe had previously explored large parts of New Zealand, so when he hears Turi dragging his canoe and finds that he is intending to flee, he gives him advice about getting to New Zealand. Turi tricks his brother in law Tuau into coming with him on his canoe.
The canoe Aotea was carrying much important cargo, including some dogs. When the canoe starts to take on water, the crew stop at a small island in the middle of the ocean and refit the canoes; they also kill one of the dogs for good and the other one as a sacrifice, and in so doing remove all ill luck from the canoes.
The tribe loses one boat, when Potoru is convinced that he should sail west rather than east. Turi has a child born during the voyage. Eventually, they reach New Zealand at the Aotea Harbour, move to Pātea, and form the ancestors of the Whanganui and Ngāti Manu tribes.
Legend of the Emigration of Manaia, the Progenitor of the Ngāti Awa Tribes
In Hawaiki, Manaia has the men of the tribe of Tupenu come make spears for him while he goes fishing to feed them. While he is gone, the workmen assault his wife, Rongotiki, which Manaia discovers through the omen of catching a fish by its tail. Manaia seeks revenge by tricking the workmen into making spears too heavy to effectively use and slaughtering them in an ambush.
When news of the ambush spreads, Manaia's tribe starts to come under attack, so he decides to seek a new land. He makes the canoe Tokomaru seaworthy and sacrifices his brother-in-law, who would not travel with him. Manaia's dog smells land and jumps off the canoe, swimming to Aotea, where the tribe finds the carcass of a whale. Conflict between the first canoes to arrive leads Manaia to travel throughout the island, eventually settling at the mouth of the Waitara River.
The Story of Hinemoa
Hinemoa, admired for her beauty and noble birth, was the daughter of Umukaria, a chief of the Ngāti Unui-kara-hapu tribe. Tūtānekai, although born from an affair between Rangiuru and Tūwharetoa, was raised as Whakaue’s son alongside his half-siblings.
Hinemoa and Tūtānekai fell in love during tribal gatherings, although her family forbade her from marrying. Tūtānekai often played music with Tiki, his hoa takatāpui, from a balcony on Mokoia Island, and the sweet sounds of their instruments would reach Hinemoa across the waters of Lake Rotorua. Hinemoa and Tūtānekai secretly planned for Hinemoa to join him on the island.
To prevent her from going to Tūtānekai, Hinemoa's friends removed all the canoes from the shore of the lake, and so Hinemoa decided to swim across the lake. She used six large gourds as flotation devices and set off under the cover of darkness, guided only by the sound of Tūtānekai's music. Exhausted, she reached a hot spring on Mokoia Island, where she disguised herself and broke calabashes to draw out Tūtānekai.
Tūtānekai recognised Hinemoa by her voice, and took her back to his house to consummate their love. The next morning, the other residents of the village were amazed to find Hinemoa there and married to Tūtānekai. Tiki mourned at this, and so Tūtānekai suggested that his younger sister Tupa marry him.
The Story of Marutūāhu, the Son of Hotunui, and of Kahureremoa, the Daughter of Paka
Hotunui arrives in Kāwhia on the Tainui, but is falsely accused of stealing sweet potatoes, so departs for Hauraki, leaving behind his pregnant wife. When his son, Marutūāhu, comes of age, he seeks out Hotunui in Hauraki. Upon arrival, Marutūāhu and his slave encounter the two daughters of Te Whatu, the chief of Hauraki, and the younger and prettier of the two claims him as her future husband. Hotunio is overjoyed to see his son and welcomes him with a feast. Marutūāhu ends up marrying the younger sister, and his younger brother Te Paka marries the older one. Marutūāhu has three children, from whom descend Ngāti Rongoū, Ngāti Tamaterā, and Ngāti Whanaunga.
During his time in Hauraki, Marutūāhu learns of the insult given to his father by another tribe who had refused to share their fish him. To get revenge, Marutūāhu spends months preparing fishing nets and eventually invites the offending tribe to a feast, under the pretense of stretching the nets. The nearly thousand men, occupied with the task, are trapped in the nets and slaughtered by Marutūāhu and 140 men in an event known as "the feast of rotten wood."
Te Paka's daughter, Te Kahureremoa, reaches age for marriage at about the same time that a large party of visitors arrives from Aotea, and Te Paka arranges for her to marry the son of the chief from Aotea. Te Kahureremoa refuses to go with the tribe; when the chief returns with additional gifts she still refuses. Te Kahureremoa instead runs away to Takakōpiri, a great young chief that she has heard of, and marries him. She gives birth to a daughter from whom descend the principle chiefs of Ngāti Pāoa.
The Two Sorcerers
Kiki is a sorcerer that lives on the Waikato River of great power and killing ability; word of his skill reaches Tāmure, another skilled sorcerer from Kāwhia. Tāmure sets out by river with his daughter, and they manage to land without being seen. By having his daughter pretend to eat the food they are given and by reciting protective enchantments, Tāmure survives Kiki's enchantments and causes his death. Tāmure and his people escape by canoe, and deceive the villagers that pursue them.
The Magical Wooden Head
Puarata and Tautōhito dwell on the Sacred Mount with an enchanted head that bewitched all that dared approach their fortress, though many tried. Hakawau resolves to conquer it, and in a trance forsees that he will be able to. On the journey to the Sacred Mount, he repeats incantations to protect him, and he sends forth the spirits under his control to destroy the evil spirits of the fortress. Once in the fortress, he uses his sorcery to destroy all who resided within, including the sorcerer there.
The Art of Netting Learned by Kāhukura from the Fairies
Kāhukura visits Rangiaowhia; along the road, he finds a lot of mackerel on the side of the road, and determines from the small footprints that they were caught by fairies. That night he lies in wait for the fairies to return, and because he is of incredibly pale skin, he is able to join in with them in their fishing. Kāhukura delays them, and when the sun comes up and they can see that he is a man, they run away, leaving behind a net from which Kāhukura can learn their knotting patterns.
Te Kanawa’s Adventure with a Troop of Fairies
Te Kanawa is hunting kiwi with his dogs when his hunting party is set on by a troop of fairies. To attempt to amuse and please the fairies to save his life, he takes off his pounamu jewelry, and the fairies take similitudes of them and leave the people alone. In the morning, the hunting party leaves as soon as they are able.
The Loves of Takarangi and Raumahora
Raumahora is the daughter of Rangirarunga, a chief of the Taranaki tribe whose beauty was known to Takarangi, son of a chief of the Ngāti Awa tribe. The army of Ngāti Awa sieges the pā of Raumahora, but is not able to take it until the tribe starts to die of thirst. Rangirarunga appeals to Takarangi for water; Takarangi thinks that he would not like Raumahora to die of thirst, and so brings water. Raumahora likes the look of Takarangi, and takes him for a husband, ending the war.
Stratagem of Puhihuia’s Elopement with Te Ponga
Puhihuia is the chief's daughter in what is now Mount Eden; in old times, their tribe was at war with the tribes of Āwhitu and Waikato. Te Pongo, a young chief from Āwhitu visits Mount Eden, and is entranced by Puhihuia's dancing. He charms her with his dancing, and when they have an opportunity to talk they resolve to escape together. After a formal farewell, Puhihuia flees with Te Ponga and his men; her tribe attempts to pursue them but fails due to Te Ponga's sabotage of their canoes.
The History of Pāoa, the Ancestor of the Ngāti Pāoa Tribe
Pāoa, of the Ngāti Kahungunu tribe, goes on a journey after his wife leaves following a quarrel, but is unable to find her. He eventually settles in Waikato, remarries, and has children. He leaves his new wife for a slave, who he makes his slave wife, and his old slave returns to the principal wife and is prosperous with her. Pāoa is ashamed by his inability to provide for guests, and so departs again.
Pāoa settles in the village Mirimirirau on the Piako River, where he gains respect and is as a chief. His reputation spreads, and when a visiting party from his village visits Tukutuku, the unmarried daughter of a chiet, they carry back word that she is interested in Pāoa. Pāoa sets out to visit Tukutuku at her village, and though he is initially hesitant, Pāoa accepts Tukutuku's advances and they are wed. They journey through her lands, receiving gifts and admiration, and Tukutuku impresses Pāoa's people in his village.
Later, Pāoa, now old, wishes to visit his other children. Despite warnings from his youngest son Horowhenua, he goes and is detained by his first two sons. Horowhenua leads a rescue mission, resulting in a fierce battle; he kills his half-brothers, Toawhena and Toapoto, and brings Pāoa back to safety. Pāoa's descendants are the Ngāti Pāoa tribe.
Cultural impact
Polynesian Mythology was well received by the European public, with Grey receiving many letters of praise. In particular, the story of Hinemoa was popular enough to inspire Alfred Domett's novel Ranolf and Amohia, Nicholas Chevalier's painting Hinemoa, and New Zealand's first feature film in 1914.
Polynesian Mythology has been described as "one of the earliest published collections of Maori traditional material ... [and] also the most authoritative" and "an achievement unparalleled in Polynesian literature." Katharine Luomala wrote that the work "holds a place comparable to that of Malory’s ‘Morte d’Arthur’ in English literature. Sir George Grey is the Caxton to whom we owe gratitude for preserving this masterpiece.”
Scholarly critiques of Polynesian Mythology discusses the difficulties of constructing a single authentic version of the myths. Percy Smith reported that Te Rangikāheke "had never been educated as a priest, and consequently many old men of the Arawa tribe will tell you that his work is a pokanoa, or unauthorised proceeding, and not correct, inasmuch, as it leaves out much detail, and actions are frequently credited to the wrong individuals."
Additional critique grapples with ways in which George Grey himself interacted with the source material and contributors. Scholars note that Grey did not acknowledge in writing the contributions of any of the Māori sources that supplied him with manuscript pages (especially Te Rangikāheke), and that he made changes to those manuscripts that were not authentic to the tradition of the myths.
References
External links
Māori mythology
Mythology, Maori
Māori religion
Creation myths | Polynesian Mythology (book) | [
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] | 7,231 | [
"Cosmogony",
"Creation myths"
] |
74,680,004 | https://en.wikipedia.org/wiki/Vesta%20%28rocket%29 | The Vesta sounding rocket, conceived in 1962 by the Laboratoire de Recherches Balistiques et Aérodynamiques (LRBA), a specialized French Army research facility focused on liquid-propelled rocket development. The initial letter "V" in its name is derived from the city of Vernon.
It was the outcome of an initiative by CNES with the purpose of enabling transportation of more substantial experiments to greater altitudes than the Véronique sounding rocket, also created by the LRBA and in active service at the time.
Technical details
Operated by a 160 kN thrust engine using a combination of nitric acid and turpentine as propellants, the Vesta rocket was 10.2 meters tall with a diameter of 1 meter. Weighing 5.1 tons excluding its payload, Vesta had the capability to send a 500 kg to an altitude of 400 km.
Launches
Between 1965 and 1969 a total of five Vesta rockets were launched. These launches took place from both CIEES and Kourou. The first two launches primarily served as validation tests for the rocket's operation, whereas the subsequent three carried out scientific experiments.
A pig-tailed macaque named Martine was launched on March 7, 1967, and another named Pierette on March 13. These suborbital flights reached and , respectively. Martine became the first monkey to survive more than a couple of hours after flying above the international definition of the edge of space. (Ham and Enos, launched earlier by the United States, were chimpanzees).
See also
French space program
Véronique
Diamant
References
Sounding rockets of France
Experimental rockets
Animals in space | Vesta (rocket) | [
"Chemistry",
"Biology"
] | 337 | [
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] |
74,680,257 | https://en.wikipedia.org/wiki/Environmental%20Rights%20Action | Environmental Rights Action (ERA), sometimes referred to as Friends of Earth Nigeria, is a Nigerian advocacy non-governmental organization, with a focus on the environmental human right issues in Nigeria and protection of the human ecosystem. The organization which was established in 1993, is the Nigerian chapter of Friends of the Earth International. The goals of the organization is to help promote environmentally responsible government and communities in Nigeria. The top priority areas for the organization include advocating for waste and plastic policies and regulations, building coalitions and strengthening alliances, regional and international advocacy to expose the violations connected to industrial plantation companies, who are drivers of biodiversity loss at all levels of work.
Campaign and Project
Environmental Rights Action coordinated and hosted Oilwatch International, the Africa Tobacco Control Regional Initiative (ATCRI), the Nigerian Tobacco Control Alliance (NTCA). In addition, the organization is involved in Green Alliance Nigeria (GAN).
Awards and recognition
ERA have received the following awards and recognition:
2009 Bloomberg Awards for Global Tobacco Control
1998 Sophie Prize for excellence and courage in the struggle for environmental Justice
See also
Friends of the Earth, Inc. v. Laidlaw Environmental Services, Inc.
List of environmental organizations
Friends of the Earth (HK)
References
Anti-nuclear organizations
Environmental organizations established in 1993 | Environmental Rights Action | [
"Engineering"
] | 252 | [
"Nuclear organizations",
"Anti-nuclear organizations"
] |
74,680,574 | https://en.wikipedia.org/wiki/Is%20Mars%20Habitable%3F | Is Mars Habitable? A Critical Examination of Professor Percival Lowell's Book "Mars and Its Canals," with an Alternative Explanation is a 1907 non-fiction book by British naturalist Alfred Russel Wallace (1823–1913). The work is a followup to his previous work, Man's Place in the Universe (1903), which initially explored the potential for extraterrestrial life. Is Mars Habitable? follows a similar theme, but is more of a reply and refutation of the book Mars and Its Canals (1906) by astronomer Percival Lowell. Lowell famously argued that an advanced, intelligent civilization engineered Martian canals on the surface of the planet, a now-discredited idea. Wallace's book evaluates Lowell's theory, eventually concluding that Mars "is not only uninhabited by intelligent beings such as Mr. Lowell postulates, but is absolutely uninhabitable", a conclusion Wallace had already reached in Man's Place in the Universe. Historian Charles H. Smith refers to Wallace's book as one of the first works in the field of astrobiology.
See also
"The Things that Live on Mars" (1908)
References
Bibliography
Milner, Richard (November 4, 2011). "A Wet Red World? The Search for Water on Mars Goes On". Astrobiology Magazine. Space.com. Retrieved August 26, 2023.
Slotten, Ross A. (2004). The Heretic in Darwin's Court: The Life of Alfred Russel Wallace. Columbia University Press. .
Smith, Charles H. (2018). Is Mars Habitable? (S730: 1907). The Alfred Russel Wallace Page. Western Kentucky University. Retrieved August 26, 2023.
Wallace, Alfred R. (1907). Is Mars Habitable? A Critical Examination of Professor Percival Lowell’s Book 'Mars and its Canals,' with an Alternative Explanation. Macmillan.
Wallace, Alfred R. (January 27, 1908). "Letter to the Editor". The Daily News. no. 19303: 6f.
"Is Not Convinced of Life on Mars". ''The New York Times'. no. 18116: 3a-b. August 31, 1907.
1907 books
Mars in culture
Works by Alfred Russel Wallace
Books about extraterrestrial life | Is Mars Habitable? | [
"Astronomy"
] | 471 | [
"Astronomy book stubs",
"Astronomy stubs"
] |
74,680,802 | https://en.wikipedia.org/wiki/Clearance%20%28civil%20engineering%29 | In civil engineering, clearance refers to the difference between the loading gauge and the structure gauge in the case of railroad cars or trams, or the difference between the size of any vehicle and the width/height of doors, the width/height of an overpass or the diameter of a tunnel as well as the air draft under a bridge, the width of a lock or diameter of a tunnel in the case of watercraft. In addition, there is the difference between the deep draft and the stream bed or sea bed of a waterway.
For roadways and waterways, the clearance is typically specified as the width/height of a structure that the vehicle needs to pass instead of the difference between the vehicle and the structure.
Railways
In railways, clearance is the difference between the loading gauge and the structure gauge. A clearance standard is established using static rolling stock outline (static gauge) as the starting point. This is a cross-sectional outline of a maximum size rolling stock when it is not running. The standard then defines maximum kinematic rolling stock outline for when rolling stocks are running to account for suspension and lateral motion on the track. This is also known as "kinematic envelope". The standard also defines base operating standard for clearance which is larger than the kinematic envelope. This should be maximum outline of the normal rail operation and can only be infringed in special circumstances. The standard then adds another outline called maintenance intervention standard outline that larger than the base operating standard by defining a safety margin (contingency gap) from the kinematic envelope. When there is an infringement of this outline, a maintenance work is required to bring to clearance standard. This establishes the loading gauge. Finally, the standard includes structure outline or structure gauge, leaving a space between the loading gauge and structure gauge as clearance.
Roadways
Vertical clearance
In roadways, vertical clearance is the measurement from the ground or the road pavement to the bottom of overpasses or bridges.
American Association of State Highway Officials (AASHO) established Interstate Highway standards which included minimum vertical clearance of . The Department of Defense later informed that the clearance was not sufficient for national defense purposes and wanted the vertical clearance to be raised to . Eventually, the new standards were approved in 1960 to have the minimum vertical clearance of new structures to be . There were up to 2,650 existing overpasses in 1967 that were not in compliance with the new standards. The decision was made to only raise those 350 overpasses that served up to 95% of major military installations. Other overpasses were left to be reconstructed to the new minimum vertical clearance at later times.
Australia defines minimum vertical clearance based on types of roads. The minimum vertical clearance is for main roads and highways, and for other local roads with road authority approval. For high and very high clearance roads, the values are between and .
Eurocode 1: Actions on structures has a definition of "physical clearance" between roadway surface and the underside of bridge element. The code also defines the clearance that is shorter than the physical clearance to account for sag curves, bridge deflection and expected settlements) with a recommendation of minimum clearance of .
In Singapore, the minimum vertical clearance is . The clearance for overhead signs is and the clearance for the soffit or underside of overpasses is .
In South Africa and the southern region of Africa, the minimum vertical clearance of modern bridges is , although the legal height limit of road vehicles is still at .
United Kingdoms has a standard on minimum clearance of a public highway at . Any bridges that do not meet the clearance requirement are considered to be "low bridges" and they require to have signage to indicate the clearance.
Bridge and tunnel strikes
Bridge or tunnel strikes are collisions of vehicles with bridge or tunnel structures. These may involve over-height vehicles, or low vertical clearance bridges or tunnels. These accidents occur frequently and are a major issue worldwide. In United Kingdom, railway bridge strikes happen on an average of once every four and half hours with total of 1789 times in 2019. Several bridges being hit over 20 times in a single year. The total cost borne by the state was around £23 million. In Beijing,
China, 20% of all bridge damages are caused by bridge strikes. Texas Department of Transportation estimated in 2013 that an average cost to repair a bridge strike is US$180,000.
A high overpass bridge near St Petersburg, Russia, is known as the "Bridge of Stupidity" because it is often struck by vehicles despite many warning signs. In May 2018, after it was struck for the 150th time by a GAZelle truck, a birthday cake was presented to the bridge. This made national news.
Similarly, an overpass in Durham, North Carolina, US, was frequently struck by vehicles, and made the news a number of times until it was raised in 2019.
Infrared sensors, which trigger warning signs when a high vehicle approaches, were added to an underpass in Frauenfeld, Switzerland, only after several incidents.
A similar situation exists at an underpass on Guy Street in Montreal, which has a clearance of .
Horizontal clearance
In United States, the term "horizontal clearance" is used interchangeably with "lateral offset". This is the space from the edge of the roadway that is clear from vertical obstructions such as sign posts, utility poles, and fire hydrants. The horizontal clearance is used in urban environments where these objects are expected to be near roadways. The horizontal clearance are to prevent overhung elements such as side mirrors of large vehicles driven at the extreme edge of the roads to hit such objects. It also allows opening curbside doors of parked vehicles. Minimum horizontal clearance in US standard is . Horizontal clearance is not the same concept as clear zone which is used in non-urban highways.
Some countries have specific horizontal clearances from the edge of the roads for specific types of objects next to the roads. For example, India has horizontal clearance of for electrical and telecommunication poles, and for street light poles of roads with curbs. For roads without curbs, the clearance for that is given that the minimum clearance from the center line of the roads is .
For roadways that require passing under some structures such as tunnels, there are standards on the entire width of the roads known as horizontal curb-to-curb and wall-to-wall clearances. American Association of State Highway and Transportation Officials (AASHTO) recommends having minimum curb-to-curb clearance for two-lane highways of and wall-to-wall clearance of , while desired curb-to-curb clearance should be , and
wall-to-wall clearance should be .
For bike paths, there are two types of horizontal clearances. The first type is the horizontal clearance of any obstacles on the paths. An example is the use of bollards to prevent cars from entering bike paths. The horizontal clearance on the paths defines a minimum clearance of adjacent obstacles such as those bollards to allow clear flowing of bike traffic. Some European countries have that specification between and . The second type is horizontal clearance next to the paths. This clearance is a distance from the edge of the biking paths to any vertical obstacles such as poles, fences, and tree branches to prevent pedal or handlebar from hitting such obstacles. The clearance values may depend on the heights and types of the obstacles. For example, in Flanders, the horizontal clearance next to the paths for poles, lampposts and trees is , and for walls and fences is . The horizontal clearance from the edge of the path to the curb is based on curb heights. For curbs of heights up to , the horizontal clearance is , and for higher curbs, the clearance is .
Waterways
In waterways, "bridge span clearance" is a measurement from water surface to the underside of bridge span. The most conservative clearance uses the water level at the mean highest high water (MHHW), the average value of the highest high tide of a measurement period. This is known as "clearance below", "vertical clearance" and "charted height"
On other hand, the "overhead clearance" is a measurement from the top most part of a given vessel to the underside of the bridge. The "underkeel clearance" is the distance between the lowest part of a given vessel to the waterway bed.
The other type of clearances for the bridges is "clearance above" the bridge floor. This is the vertical clearances for road traffic on the bridge.
See also
Air draft
Engineering tolerance
Ground clearance
References
Engineering concepts
Approximations | Clearance (civil engineering) | [
"Mathematics",
"Engineering"
] | 1,716 | [
"Mathematical relations",
"Approximations",
"nan"
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74,683,393 | https://en.wikipedia.org/wiki/German%20Zoological%20Society | The German Zoological Society (German: Deutsche Zoologische Gesellschaft; DZG) is a learned society in Germany, founded in 1890 at Frankfurt am Main. It is registered as a non-profit organisation (German: eingetragene Verein) based in Munich.
Activities
The DZG represents German-speaking zoologists and corresponds with other regional and national zoological societies. It represents the interests of zoology among the scientific learned societies and can be consulted by politicians for advice. Membership is open to any zoologist or student of zoology; the DZG currently has about 1500 members. It organises an annual meeting, which until 2004 was held during the week of Pentecost. However, as many universities no longer have a recess during that period, since 2005 the date of the meeting has been decided by the host university.
The DZG publishes its own scientific journal, Frontiers in Zoology, founded in 2004. It is published in cooperation with the online publisher BioMed Central. The DZG formerly published the Zoologische Anzeiger and Zoologische Jahrbücher, since discontinued.
The DZG awards several prizes to support or recognise scientific work.
Karl Ritter von Frisch Medal
The Karl Ritter von Frisch Medal is a scientific prize of the DZG. The Medal has been awarded every two years since 1980, to scientists who have distinguished themselves through outstanding zoological work that integrates knowledge from numerous biological disciplines. It is the most prominent scientific prize for zoology in Germany, with an award sum of 10,000 Euros.
List of medallists: 1980 Franz Huber, behavioral science
1982 Werner Nachtigall, bionics
1984 Otto Kinne, marine ecology
1986 Martin Lindauer, behavioral science
1988 Thomas Eisner, biology and chemical ecology
1990 Gerhard Neuweiler, zoology, neuro- and sensory physiology
1992 Herbert Jäckle, biophysics
1994 Rüdiger Wehner, zoology and behavioral science
1996 Bert Hölldobler, behavioral science, socbiology, evolutionary ecology
1998 Peter Berthold, ornithology
2000 Walter J. Gehring, developmental biology and genetics
2002 Friedrich G. Barth, neurobiology
2004 Randolf Menzel, neurobiology
2006 Martin Heisenberg, neurobiology
2008 Gerhard Heldmaier, animal physiology
2010 (no award)
2012 Horst Bleckmann, neuro-, sensory, and behavioral physiology
2014 Charlotte Helfrich-Förster, neurobiology
2016 Diethard Tautz, molecular biology
2018 Stanislav N. Gorb, bionics
2021 Jürgen Heinze, evolutionary biology
2022 Thomas Bosch, developmental biology
Horst Wiehe Dissertation Prize
The Dissertation Prize of the Horst-Wiehe-Stiftung has been awarded every two years at the DZG Annual Meeting since 1991, to an outstanding doctoral or habilitation thesis on a zoological subject. The prize sum is 2000 Euros (formerly 4000 Deutsche Mark). 2021 Fabrizia Ronco (Universität Basel, CH)
2019 Manon Schweinfurth (University of St Andrews, UK)
2017 Markus Lambertz (Universität Bonn)
2015 Alexander Blanke (Hull, UK)
2013 Jan Clemens (Princeton, NJ)
2011 Joachim Haug (Universität Ulm)
2009 Sandra Steiger (Universität Freiburg)
2007 Lutz Fromhage (Universität Hamburg/Bristol)
2005 Martin Fanenbruck (Universität Bochum)
2003 Wolfgang Forstmeier (Universität Würzburg)
2001 Klaus Fischer (Universität Bayreuth)
1999 Sylvia Ortmann (Universität Marburg)
1997 Erhard Strohm (Würzburg)
1995 Thomas Lubjuhn (Bonn)
1993 Heike Hadrys (Braunschweig/Yale)
1991 Henning Schneider (Konstanz/Harvard)
Werner Rathmayer Prize
The Werner Rathmayer Prize is a special prize for original work in zoology, within the Jugend forscht competition for young scientists. It has been awarded annually since 2004. The recipient receives a prize of 500 Euros and free admission to the DZG Annual Meeting in the following year. 2021 Benjamin Palm (Heiligenhaus)
2019 Falco Eigner (Chemnitz)
2017 Stefan Kemmerich (Wipperfürth)
2016 Nora Siefert (Hannover)
2015 Thomas Lindner (Neumarkt in der Oberpfalz)
2014 Freia-Raphaella Lorenz (Bayreuth)
2013 Antonia Trede (Kiel)
2012 Linda Marx (Chemnitz)
2011 Miriam Kreß & Louise Hildebrand (Schlüchtern)
2010 Lisa Hallex (Freiberg)
2009 Jessica Oberheim (Bensheim)
2008 Johannes Dill (Dresden)
2007 Wieland Heim (Chemnitz)
2006 Markus Neumann (Chemnitz)
2005 Sascha Hoinkiss (Schwanewede)
2004 Daniel Schütz (Kemmern)
Presidents of the DZG
1890/91 Rudolf Leuckart (1822–1898)
1892/93 Franz Eilhard Schulze (1840–1921)
1894/95 Ernst Ehlers (1835–1925)
1896/97 Otto Bütschli (1848–1920)
1898/99 Franz Eilhard Schulze
1900/01 Hubert Ludwig (1852–1913)
1902/03 Carl Chun (1852–1914)
1904/05 Johann Wilhelm Spengel (1852–1921)
1906/07 Richard Hertwig (1850–1937)
1908/09 Ludwig von Graff (1851–1924)
1910/11 Friedrich Zschokke (1860–1936)
1912/13 Eugen Korschelt (1858–1946)
1914/15 Karl Heider (1856–1935)
1916/17 Max Braun (1850–1930)
1918/19 Willy Kükenthal (1861–1922)
1920/21 Ludwig Döderlein (1855–1936)
1922/23 Valentin Haecker (1864–1927)
1924/25 Hans Lohmann (1863–1934)
1926 Ludwig Rhumbler (1864–1939); from 1926 the President was replaced by their first deputy at the end of the year
1927 Richard Hesse (1868–1944)
1928 Karl von Frisch (1886–1982)
1929 Jan Versluys (1873–1939)
1930 Waldemar Schleip (1879–1948)
1931 Max Hartmann (1876–1962)
1932 Carl Zimmer (1873–1950)
1933 Fritz Baltzer (1884–1974), resigned his position because he was not a German citizen, replaced by Paul Buchner
1934 Paul Buchner (1886–1978)
1935 Ernst Matthes (1889–1958)
1936 Ernst Matthes left Germany on political grounds for Coimbra and was replaced by Wilhelm Josef Schmidt
1936/37 Wilhelm Joseph Schmidt (1884–1974)
1938/39 Albrecht Hase (1882–1962)
1940 Hermann Weber (1899–1956)
1941 Hans-Jürgen Stammer (1899–1968)
1942 Otto Mangold (1891–1962)
1943–45 Adolf Remane as acting president
1949/50 Albrecht Hase
1951/52 Wulf Emmo Ankel (1897–1983)
1953/54 Bernhard Rensch (1900–1990)
1955/56 Otto Koehler (1889–1974)
1957/58 Curt Kosswig (1903–1982)
1959/60 Alfred Kaestner (1901–1971)
1961/62 Friedrich Seidel (1897–1992)
1963/64 Adolf Remane (1898–1976)
1965/66 Manfred Gersch (1909–1981)
1967/68 Erich Reisinger (1900–1978)
1969/70 Martin Lindauer (1918–2008)
1971/72 Friedrich Schaller (1920–2018)
1973/74 Günther Osche (1926–2009)
1975/76 Ernst Florey (1927–1997)
1977/78 Dietrich Neumann (1931–2012)
1979/80 Johann Schwartzkopff (1918–1995)
1981/82 Jürgen Boeckh (1934–)
1983/84 Klaus Immelmann (1935–1987)
1985/86 Hans Schneider (1929–2023)
1987/88 Bernt Linzen (1931–1988)
1989/90 Werner Rathmayer (1937–2003)
1991/92 Hans-Rainer Duncker (1933–)
1993/94 Franz Huber (1925–2017)
1995/96 Klaus Peter Sauer (1941–2022)
1997/98 Gerhard Heldmaier (1941–)
1999/00 Albrecht Fischer (1937–)
2001/02 Gerhard Neuweiler (1935–2008)
2003/04 Barbara König (1955–)
2005/06 Diethard Tautz (1957–)
2007/08 Johann-Wolfgang Wägele (1953–)
2009/10 Wolf-Michael Weber (1954–)
2011/12 Hermann Wagner (1953–)
2013/14 Constance Scharff (1959–)
2015/16 Susanne Dobler (1956–)
2017/18 Stefan Richter (1964–)
2019/21 Jacob Engelmann
2022/23 Gabriele Uhl
Honorary members
Wulf Emmo Ankel
Carl Apstein
Walther Arndt
Hansjochem Autrum
Fritz Baltzer
Paul Buchner
Reinhard Dohrn
Ernst Ehlers
Manfred Gersch
Alexander Goette
Richard Goldschmidt
Hermann Grenacher
Karl Grobben
Ernst Hadorn
Ernst Haeckel
Max Hartmann
Albrecht Hase
Karl Heider
Wolf Herre
Konrad Herter
Richard Hertwig
Richard Hesse
Franz Huber
Otto Kinne
Eugen Korschelt
Curt Kosswig
Alfred Kühn
Robert Lauterborn
Rudolf Leuckart
Franz von Leydig
Martin Lindauer
Konrad Lorenz
Alexander Luther
Paul Mayer
Ernst Mayr
Günther Osche
Heinz Penzlin
Bernhard Rensch
Wilhelm J. Schmidt
Franz Eilhard Schulze
Johann Schwartzkopff
Friedrich Seidel
Hans Spemann
Karl von Frisch
Rüdiger Wehner
August Weismann
Wolfgang Wieser
Otto zur Strassen
Networking
The Society is a member of the Deutschen Nationalkomitee Biologie (DNK), representing the interests of life scientists in international organisations. It is also a member of the Verband Biologie, Biowissenschaften und Biomedizin in Deutschland e.V. (VBIO), which represents bioscientists in Germany.
Jena Declaration
→ main article: Jena Declaration
At its annual meeting in September 2019, the DZG approved and released the Jena Declaration, which stated that "the concept of [human] race is the result of racism, not its prerequisite." The Declaration was authored by Martin S. Fischer, Uwe Hoßfeld, Johannes Krause, and Stefan Richter.
The statement characterised the division of humanity into races as social and political stereotyping, resulting from and supported by an anthropological construct on the basis of arbitrarily chosen features like hair and skin colour. This construct has served to justify open and hidden racism and its consequences.
See also
Frankfurt Zoological Society
References
External links
Official website
Frontiers in Zoology
Jena Declaration
Zoology-related lists
Lists of scientists
1890 establishments
Zoology organizations | German Zoological Society | [
"Technology"
] | 2,271 | [
"Lists of scientists",
"Lists of people in STEM fields"
] |
74,683,745 | https://en.wikipedia.org/wiki/Resurgent%20function | The term resurgent function (from , to get up again) comes from French mathematician Jean Écalle's theory of resurgent functions and alien calculus. The theory evolved from the summability of divergent series (see Borel summation) and treats analytic functions with isolated singularities. He introduced the term in the late 1970s.
Resurgent functions have applications in asymptotic analysis, in the theory of differential equations, in perturbation theory and in quantum field theory.
For analytic functions with isolated singularities, the Alien calculus can be derived, a special algebra for their derivatives.
Definition
A -resurgent function is an element of , i.e. an element of the form from , where and is a -continuable germ.
A power series whose formal Borel transformation is a -resurgent function is called -resurgent series.
Basic concepts and notation
Convergence in :
The formal power series is convergent in if the associated formal power series has a positive radius of convergence. denotes the space of formal power series convergent in .
Formal Borel transform:
The formal Borel transform (named after Émile Borel) is the operator defined by
.
Convolution in :
Let , then the convolution is given by
.
By adjunction we can add a unit to the convolution in and introduce the vector space , where we denote the element with . Using the convention we can write the space as and define
and set .
-resummable seed:
Let be a non-empty discrete subset of and define .
Let be the radius of convergence of . is a -continuable seed if an exists such that and , and analytic continuation along some path in starting at a point in .
denotes the space of -continuable germs in .
Bibliography
Les Fonctions Résurgentes, Jean Écalle, vols. 1–3, pub. Math. Orsay, 1981-1985
Divergent Series, Summability and Resurgence I, Claude Mitschi and David Sauzin, Springer Verlag
"Guided tour through resurgence theory", Jean Écalle
References
Functional analysis | Resurgent function | [
"Mathematics"
] | 433 | [
"Functional analysis",
"Functions and mappings",
"Mathematical relations",
"Mathematical objects"
] |
74,686,427 | https://en.wikipedia.org/wiki/Mental%20health%20of%20LGBTQ%20people | People who are LGBT are significantly more likely than those who are not to experience depression, PTSD, and generalized anxiety disorder.
Risk factors and the minority stress model
The minority stress model takes into account significant stressors that distinctly affect the mental health of those who identify as lesbian, gay, bisexual, transgender, or another non-conforming gender identity. Some risk factors that contribute to declining mental health are heteronormativity, discrimination, harassment, rejection (e.g., family rejection and social exclusion), stigma, prejudice, denial of civil and human rights, lack of access to mental health resources, lack of access to gender-affirming spaces (e.g., gender-appropriate facilities), and internalised homophobia. The structural circumstance where a non-heterosexual or gender non-conforming individual is embedded in significantly affects the potential sources of risk. The compounding of these everyday stressors increase poor mental health outcomes among individuals in the LGBT community. Evidence shows that there is a direct association between LGBT individuals' development of severe mental illnesses and the exposure to discrimination.
In addition, there are a lack of access to mental health resources specific to LGBT individuals and a lack of awareness about mental health conditions within the LGBT community that restricts patients from seeking help.
Limited research
There is limited research on mental health in the LGBT community. Several factors affect the lack of research on mental illness within non-heterosexual and non-conforming gender identities. Some factors identified: the history of psychiatry with conflating sexual and gender identities with psychiatric symptomatology; medical community's history of labelling gender identities such as homosexuality as an illness (now removed from the DSM); the presence of gender dysphoria in the DSM-V; prejudice and rejection from physicians and healthcare providers; LGBT underrepresentation in research populations; physicians' reluctance to ask patients about their gender; and the presence of laws against the LGBT community in many countries. General patterns such as the prevalence of minority stress have been broadly studied.
There is also a lack of empirical research on racial and ethnic differences in mental health status among the LGBT community and the intersection of multiple minority identities.
Stigmatization of LGBT individuals with mental illness
There is a significantly greater stigmatization of LGBT individuals with more severe conditions. The presence of the stigma affects individuals' access to treatment and is particularly present for non-heterosexual and gender non-conforming individuals with schizophrenia.
Disorders
Anxiety
LGBT individuals are nearly three times more likely to experience anxiety compared to heterosexual individuals. Gay and bisexual men are more likely to have generalized anxiety disorder (GAD) as compared to heterosexual men.
Depression
Individuals who identify as non-heterosexual or gender non-conforming are more likely to experience depressive episodes and suicide attempts than those who identify as heterosexual. Based solely on their gender identity and sexual orientation, LGBT individuals face stigma, societal bias, and rejection that increase the likelihood of depression. Gay and bisexual men are more likely to have major depression and bipolar disorder than heterosexual men.
Transgender youth are nearly four times more likely to experience depression, as compared to their non-transgender peers. Compared to LGBT youth with highly accepting families, LGBT youth with less accepting families are more than three times likely to consider and attempt suicide. As compared to individuals with a level of certainty in their gender identity and sexuality (such as LGB-identified and heterosexual students), youth who are questioning their sexuality report higher levels of depression and worse psychological responses to bullying and victimization. Transgender youth who report higher feelings of internalized transphobia are found to be more likely to meet the diagnostic criteria for depression. On the other hand, those who report their perceived physical appearance are consistent with their internal gender identity are less likely to be diagnosed with depression.
31% of LGBT older adults report depressive symptoms. LGBT older adults experience LGBT stigma and ageism that increase their likeliness to experience depression.
Post-traumatic stress disorder
LGBT individuals experience higher rates of trauma than the general population, the most common of which include intimate partner violence, sexual assault and hate violence. Compared to heterosexual populations, LGBT individuals are at 1.6 to 3.9 times greater risk of probable PTSD. One-third of PTSD disparities by sexual orientation are due to disparities in child abuse victimization.
Suicide
As compared to heterosexual men, gay and bisexual men are at a greater risk for suicide, attempting suicide, and dying of suicide. In the United States, 29% (almost one-third) of LGBT youth have attempted suicide at least once. Compared to heterosexual youth, LGBT youth are twice as likely to feel suicidal and over four times as likely to attempt suicide. Transgender individuals are at the greatest risk of suicide attempts. One-third of transgender individuals (both in youth and adulthood) has seriously considered suicide and one-fifth of transgender youth has attempted suicide.
LGBT youth are four times more likely to attempt suicide than heterosexual youth. Youth who are questioning their gender identity and/or sexuality are two times more likely to attempt suicide than heterosexual youth. Bisexual youth have higher percentages of suicidality than lesbian and gay youth. As compared to white transgender individuals, transgender individuals who are African American/black, Hispanic/Latinx, American Indian/Alaska Native, or Multiracial are at a greater risk of suicide attempts. 39% of LGBT older adults have considered suicide.
Substance abuse
In the United States, an estimated 20-30% of LGBT individuals abuse substances. This is higher than the 9% of the U.S. population that abuse substances. In addition, 25% of LGBT individuals abuse alcohol compared to the 5-10% of the general population. Lesbian and bisexual youth have a higher percentage of substance use problems as compared to sexual minority males and heterosexual females. However, as young sexual minority males mature into early adulthood, their rate of substance use increases. Lesbian and bisexual women are twice as likely to engage in heavy alcohol drinking as compared to heterosexual women. Gay and bisexual men are less likely to engage in heavy alcohol drinking as compared to heterosexual men.
Substance use such as alcohol and drug use among LGBT individuals can be a coping mechanism in response to everyday stressors like violence, discrimination, and homophobia. Substance use can threaten LGBT individuals' financial stability, employment, and relationships.
Eating disorders
The average age for developing an eating disorder is 19 years old for LGBT individuals, compared to 12–13 years old nationally. In a national survey of LGBTQ youth conducted by the National Eating Disorders Association, The Trevor Project and the Reasons Eating Disorder Center in 2018, 54% of participants indicated that they had been diagnosed with an eating disorder. An additional 21% of surveyed participants suspected that they had an eating disorder.
Various risk factors may increase the likelihood of LGBT individuals experiencing disordered eating, including fear of rejection, internalised negativity, post-traumatic stress disorder (PTSD) or pressure to conform with body image ideals within the LGBT community.
42% of men who experience disordered eating identify as gay. Gay men are also seven times more likely to report binge eating and twelve times more likely to report purging than heterosexual men. Gay and bisexual men also experience a higher prevalence of full-syndrome bulimia and all subclinical eating disorders than their heterosexual counterparts.
Research has found lesbian women to have higher rates of weight-based self-worth and proneness to contracting eating disorders compared to gay men. Lesbian women also experience comparable rates of eating disorders compared to heterosexual women, with similar rates of dieting, binge eating and purging behaviours. However, lesbian women are more likely to report positive body image compared to heterosexual females (42.1% vs 20.5%).
Transgender individuals are significantly more likely than any other LGBT demographic to report an eating disorder diagnosis or compensatory behaviour related to eating. Transgender individuals may use weight restriction to suppress secondary sex characteristics or to suppress or stress gendered features.
There is limited research regarding racial differences within LGBT populations as it relates to disordered eating. Conflicting studies have struggled to ascertain whether LGBT people of colour experience similar or varying rates of eating disorder proneness or diagnosis.
Coping mechanisms
Each individual has its own way to deal with difficult emotions and situations. Oftentimes, the coping mechanism adopted by a person, depending on whether they are safe or risky, will impact their mental health. These coping mechanisms tend to be developed during youth and early-adult life. Once a risky coping mechanism is adopted, it is often hard for the individual to get rid of it.
Safe coping-mechanisms, when it comes to mental disorders, involve communication with others, body and mental health caring, support and help seeking.
Because of the high stigmatization they often experience in school, public spaces and society in general, the LGBT community, and more especially the young people among them are less likely to express themselves and seek for help and support, because of the lack of resources and safe spaces available for them to do so. As a result, LGBT patients are more likely to adopt risky coping mechanisms then the rest of the population.
These risky mechanisms involve strategies such as self-harm, substance abuse, or risky sexual behavior for many reasons, including; "attempting to get away from or not feel overwhelming emotions, gaining a sense of control, self-punishment, nonverbally communicating their struggles to others." Once adopted, these coping mechanisms tend to stick to the person and therefore endanger even more the future mental health of LGBT patients, reinforcing their exposure to depression, extreme anxiety and suicide.
See also
Healthcare and the LGBTQ community
Suicide among LGBTQ people
References
LGBTQ and health
LGBT and | Mental health of LGBTQ people | [
"Biology"
] | 1,958 | [
"Mental disorders",
"Behavior",
"Human behavior"
] |
62,279,536 | https://en.wikipedia.org/wiki/Electrostatic%20septum | An electrostatic septum is a dipolar electric field device used in particle accelerators to inject or extract a particle beam into or from a synchrotron. In an electrostatic septum, basically an electric field septum, two separate areas can be identified, one with an electric field and a field free region. The two areas are separated by a physical wall that is called the septum. An important feature of septa is to have a homogeneous field in the gap and no field in the region of the circulating beam.
The basic principle
Electrostatic septa provide an electric field in the direction of extraction, by applying a voltage between the septum foil and an electrode. The septum foil is very thin to have the least interaction with the beam when it is slowly extracted. Slowly means over millions of turns of the particles in the synchrotron. The orbiting beam generally passes through the hollow support of the septum foil, which ensures a field free region, as not to affect the circulating beam. The field free region is achieved by using the hollow support of the septum and the septum foil itself as a Faraday cage. The extracted beam passes just on the other side of the septum, where the electric field changes the direction of the beam to be extracted. The septum separates the gap field between the electrode and the foil from the field free region for the circulating beam.
Electrostatic septa are always sitting in a vacuum tank to allow high electric fields, since the vacuum works as an insulator between the septum and high voltage electrode. To allow precise matching of the septum position with the circulation beam trajectory, the septum is often fitted with a displacement system, which allows parallel and angular displacement with respect to the circulating beam. Great difficulty lies in the choice of materials and the manufacturing techniques of the different components.
In the figure a typical cross section of an electrostatic septum is shown. The septum foil and its support are marked in blue, while the electrode is marked in red. In the lower part of the figure the electric field E is shown as it could be measured on the axis indicated as a dotted line in the cross section. The field free region is inside the support of the septum foil. The electric field E in the gap between the septum foil and the electrode is homogeneous on the axis and is equal to:
Where V is the voltage applied to the electrode and d is the distance between the septum foil and
the electrode.
Typical technical specifications
Typical device specifications are listed below.
Electrode length: 500 – 3000 mm
Gap width: variable between 10 – 35 mm
Septum thickness: 0.1 mm
Vacuum: (10−9 to 10−12 mbar range)
Electric field strength: up to 15 MV/m
Voltage: up to 300 kV
Septum materials: Molybdenum foil, Tungsten Rhenium alloy wires, Tungsten Rhenium alloy ribbons
Electrode materials: stainless steel, anodised aluminium or titanium for extreme low vacuum applications
Bakeable up to 200 °C for low vacuum applications
Power supplied by high voltage Cockcroft–Walton generator
References
Electrostatic Septum
Accelerator physics | Electrostatic septum | [
"Physics"
] | 639 | [
"Applied and interdisciplinary physics",
"Accelerator physics",
"Experimental physics"
] |
62,279,569 | https://en.wikipedia.org/wiki/John%20Rodenburg | John Marius Rodenburg is emeritus professor in the Department of Electronic and Electrical Engineering at the University of Sheffield. He was elected a Fellow of the Royal Society (FRS) in 2019 for "internationally recognised... work on revolutionising the imaging capability of light, X-ray and electron transmission microscopes".
Education
Rodenburg was educated at University of Exeter where he was awarded a Bachelor of Science degree in Physics with Electronics. He moved to the Cavendish Laboratory to complete his PhD on the detection and interpretation of electron diffraction patterns which was awarded by the University of Cambridge in 1986.
Career and research
Rodenburg worked until 1999 in the University of Cambridge as a University Research Fellow of the Royal Society. He is currently emeritus professor in the Department of Electronics and Electrical Engineering at the University of Sheffield.
His research interests have mostly been in improving the resolution and other capabilities of electron, X-ray and optical microscopy by processing diffraction patterns instead of using lenses. He has innovated many key developments in the diffractive imaging method called ptychography.
In 2006, Rodenburg co-founded Phase Focus Limited, which uses ptychography to image live cells to improve cancer drug design. He served as a director and Chief Scientific Officer from 2006 to 2015.
Awards and honours
Rodenburg was elected a Fellow of the Royal Society (FRS) in 2019.
Personal
Rodenburg is married to the material scientist Professor Conny Rodenburg, and is the brother of the voice coach and writer Patsy Rodenburg
References
Fellows of the Royal Society
1960 births
Living people
Academics of the University of Sheffield
Alumni of the University of Exeter
Alumni of the University of Cambridge
British materials scientists
Microscopists
English physicists | John Rodenburg | [
"Chemistry"
] | 340 | [
"Microscopists",
"Microscopy"
] |
62,280,237 | https://en.wikipedia.org/wiki/Electronics%20prototyping | In electronics, prototyping means building an actual circuit to a theoretical design to verify that it works, and to provide a physical platform for debugging it if it does not. The prototype is often constructed using techniques such as wire wrapping or using a breadboard, stripboard or perfboard, with the result being a circuit that is electrically identical to the design but not physically identical to the final product.
Open-source tools like Fritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such as Arduino also simplify the task of programming and interacting with a microcontroller. The developer can choose to deploy their invention as-is using the prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product.
A technician can quickly build a prototype (and make additions and modifications) using these techniques, but for volume production it is much faster and usually cheaper to mass-produce custom printed circuit boards than to produce these other kinds of prototype boards. The proliferation of quick-turn PCB fabrication and assembly companies has enabled the concepts of rapid prototyping to be applied to electronic circuit design. It is now possible, even with the smallest passive components and largest fine-pitch packages, to have boards fabricated, assembled, and even tested in a matter of days.
Boards
Breadboard
Perfboard
Stripboard
References
P
Prototypes | Electronics prototyping | [
"Engineering"
] | 300 | [
"Electronic engineering",
"Electronic circuits"
] |
62,285,440 | https://en.wikipedia.org/wiki/Scandinavium%20goeteborgense | Scandinavium (named after the region in Northern Europe) is a genus of Gram-negative, facultative anaerobic, oxidase-negative, rod-shaped, motile bacteria of the family Enterobacteriaceae. It contains a single species, Scandinavium goeteborgense (named after the Swedish city of Gothenburg). The type strain of the species is S. goeteborgense CCUG 66741T = CECT 9823T = NCTC 14286T and its genome sequence is publicly available in DNA Data Bank of Japan, European Nucleotide Archive and GenBank under the accession number LYLP00000000.
References
Enterobacteriaceae
Bacteria described in 2020 | Scandinavium goeteborgense | [
"Biology"
] | 152 | [
"Bacteria stubs",
"Bacteria"
] |
62,285,602 | https://en.wikipedia.org/wiki/Multi-agent%20reinforcement%20learning | Multi-agent reinforcement learning (MARL) is a sub-field of reinforcement learning. It focuses on studying the behavior of multiple learning agents that coexist in a shared environment. Each agent is motivated by its own rewards, and does actions to advance its own interests; in some environments these interests are opposed to the interests of other agents, resulting in complex group dynamics.
Multi-agent reinforcement learning is closely related to game theory and especially repeated games, as well as multi-agent systems. Its study combines the pursuit of finding ideal algorithms that maximize rewards with a more sociological set of concepts. While research in single-agent reinforcement learning is concerned with finding the algorithm that gets the biggest number of points for one agent, research in multi-agent reinforcement learning evaluates and quantifies social metrics, such as cooperation, reciprocity, equity, social influence, language and discrimination.
Definition
Similarly to single-agent reinforcement learning, multi-agent reinforcement learning is modeled as some form of a Markov decision process (MDP). For example,
A set of environment states.
One set of actions for each of the agents .
is the probability of transition (at time ) from state to state under joint action .
is the immediate joint reward after the transition from to with joint action .
In settings with perfect information, such as the games of chess and Go, the MDP would be fully observable. In settings with imperfect information, especially in real-world applications like self-driving cars, each agent would access an observation that only has part of the information about the current state. In the partially observable setting, the core model is the partially observable stochastic game in the general case, and the decentralized POMDP in the cooperative case.
Cooperation vs. competition
When multiple agents are acting in a shared environment their interests might be aligned or misaligned. MARL allows exploring all the different alignments and how they affect the agents' behavior:
In pure competition settings, the agents' rewards are exactly opposite to each other, and therefore they are playing against each other.
Pure cooperation settings are the other extreme, in which agents get the exact same rewards, and therefore they are playing with each other.
Mixed-sum settings cover all the games that combine elements of both cooperation and competition.
Pure competition settings
When two agents are playing a zero-sum game, they are in pure competition with each other. Many traditional games such as chess and Go fall under this category, as do two-player variants of modern games like StarCraft. Because each agent can only win at the expense of the other agent, many complexities are stripped away. There's no prospect of communication or social dilemmas, as neither agent is incentivized to take actions that benefit its opponent.
The Deep Blue and AlphaGo projects demonstrate how to optimize the performance of agents in pure competition settings.
One complexity that is not stripped away in pure competition settings is autocurricula. As the agents' policy is improved using self-play, multiple layers of learning may occur.
Pure cooperation settings
MARL is used to explore how separate agents with identical interests can communicate and work together. Pure cooperation settings are explored in recreational cooperative games such as Overcooked, as well as real-world scenarios in robotics.
In pure cooperation settings all the agents get identical rewards, which means that social dilemmas do not occur.
In pure cooperation settings, oftentimes there are an arbitrary number of coordination strategies, and agents converge to specific "conventions" when coordinating with each other. The notion of conventions has been studied in language and also alluded to in more general multi-agent collaborative tasks.
Mixed-sum settings
Most real-world scenarios involving multiple agents have elements of both cooperation and competition. For example, when multiple self-driving cars are planning their respective paths, each of them has interests that are diverging but not exclusive: Each car is minimizing the amount of time it's taking to reach its destination, but all cars have the shared interest of avoiding a traffic collision.
Zero-sum settings with three or more agents often exhibit similar properties to mixed-sum settings, since each pair of agents might have a non-zero utility sum between them.
Mixed-sum settings can be explored using classic matrix games such as prisoner's dilemma, more complex sequential social dilemmas, and recreational games such as
Among Us, Diplomacy and
StarCraft II.
Mixed-sum settings can give rise to communication and social dilemmas.
Social dilemmas
As in game theory, much of the research in MARL revolves around social dilemmas, such as prisoner's dilemma, chicken and stag hunt.
While game theory research might focus on Nash equilibria and what an ideal policy for an agent would be, MARL research focuses on how the agents would learn these ideal policies using a trial-and-error process. The reinforcement learning algorithms that are used to train the agents are maximizing the agent's own reward; the conflict between the needs of the agents and the needs of the group is a subject of active research.
Various techniques have been explored in order to induce cooperation in agents: Modifying the environment rules, adding intrinsic rewards, and more.
Sequential social dilemmas
Social dilemmas like prisoner's dilemma, chicken and stag hunt are "matrix games". Each agent takes only one action from a choice of two possible actions, and a simple 2x2 matrix is used to describe the reward that each agent will get, given the actions that each agent took.
In humans and other living creatures, social dilemmas tend to be more complex. Agents take multiple actions over time, and the distinction between cooperating and defecting is not as clear cut as in matrix games. The concept of a sequential social dilemma (SSD) was introduced in 2017 as an attempt to model that complexity. There is ongoing research into defining different kinds of SSDs and showing cooperative behavior in the agents that act in them.
Autocurricula
An autocurriculum (plural: autocurricula) is a reinforcement learning concept that's salient in multi-agent experiments. As agents improve their performance, they change their environment; this change in the environment affects themselves and the other agents. The feedback loop results in several distinct phases of learning, each depending on the previous one. The stacked layers of learning are called an autocurriculum. Autocurricula are especially apparent in adversarial settings, where each group of agents is racing to counter the current strategy of the opposing group.
The Hide and Seek game is an accessible example of an autocurriculum occurring in an adversarial setting. In this experiment, a team of seekers is competing against a team of hiders. Whenever one of the teams learns a new strategy, the opposing team adapts its strategy to give the best possible counter. When the hiders learn to use boxes to build a shelter, the seekers respond by learning to use a ramp to break into that shelter. The hiders respond by locking the ramps, making them unavailable for the seekers to use. The seekers then respond by "box surfing", exploiting a glitch in the game to penetrate the shelter. Each "level" of learning is an emergent phenomenon, with the previous level as its premise. This results in a stack of behaviors, each dependent on its predecessor.
Autocurricula in reinforcement learning experiments are compared to the stages of the evolution of life on Earth and the development of human culture. A major stage in evolution happened 2-3 billion years ago, when photosynthesizing life forms started to produce massive amounts of oxygen, changing the balance of gases in the atmosphere. In the next stages of evolution, oxygen-breathing life forms evolved, eventually leading up to land mammals and human beings. These later stages could only happen after the photosynthesis stage made oxygen widely available. Similarly, human culture could not have gone through the Industrial Revolution in the 18th century without the resources and insights gained by the agricultural revolution at around 10,000 BC.
Applications
Multi-agent reinforcement learning has been applied to a variety of use cases in science and industry:
AI alignment
Multi-agent reinforcement learning has been used in research into AI alignment. The relationship between the different agents in a MARL setting can be compared to the relationship between a human and an AI agent. Research efforts in the intersection of these two fields attempt to simulate possible conflicts between a human's intentions and an AI agent's actions, and then explore which variables could be changed to prevent these conflicts.
Limitations
There are some inherent difficulties about multi-agent deep reinforcement learning. The environment is not stationary anymore, thus the Markov property is violated: transitions and rewards do not only depend on the current state of an agent.
Further reading
Stefano V. Albrecht, Filippos Christianos, Lukas Schäfer. Multi-Agent Reinforcement Learning: Foundations and Modern Approaches. MIT Press, 2024. https://www.marl-book.com
Kaiqing Zhang, Zhuoran Yang, Tamer Basar. Multi-agent reinforcement learning: A selective overview of theories and algorithms. Studies in Systems, Decision and Control, Handbook on RL and Control, 2021.
References
Reinforcement learning
Multi-agent systems
Deep learning
Game theory | Multi-agent reinforcement learning | [
"Engineering"
] | 1,888 | [
"Artificial intelligence engineering",
"Multi-agent systems"
] |
62,285,853 | https://en.wikipedia.org/wiki/Pierre%20Sina%C3%BF | Pierre Sinaÿ, born on April 11, 1938, in Aulnay-sous-Bois (Seine-et-Oise), is a French organic chemist.
Biography
After studying at the École nationale supérieure des industries chimiques de Nancy from 1958 to 1961, he obtained a doctorate under the supervision of Professor Serge David in 1966 and continued for two years at Harvard University in Massachusetts (United States) as a post-doctoral researcher with Professor Roger W. Jeanloz. He then entered the University of Orléans in 1969 as a professor, where he was Director of the Institute of Organic and Analytical Chemistry from 1978 to 1987. He then became Professor of Chemistry in 1986 at the Université Pierre-et-Marie-Curie, where he then headed the Laboratory of Selective Processes in Organic and Bioorganic Chemistry in the Department of Chemistry at the École normale supérieure. He then became Professor Emeritus at Sorbonne University in 2006 and joined the Paris Institute of Molecular Chemistry.
Scientific work
Pierre Sinaÿ's scientific work focuses on the chemistry of carbohydrates and the understanding of the role of oligosaccharides in the living world. In the mid-1970s, Pierre Sinaÿ discovered and developed an effective method for oligosaccharide synthesis known as imidate glycosylation. This, by now allowing access to increasingly complex carbohydrate structures, is not unrelated to the development of glycobiology, the aim of which is to decode the meaning of this third alphabet of saccharides, which is in addition to that of proteins and nucleic acids. He synthesized the antigenic determinants of substances in human blood groups and then synthesized a complexly structured pentasaccharide representing the active site of heparin responsible for its antithrombotic effect. This last achievement demonstrates for the first time, without any ambiguity, the molecular basis of such an activity, commonly used in hospital medicine. This breakthrough in glyco-chemistry has led to the concept of conformational flexibility, which is crucial in heparinology. First materialized by the use of nuclear magnetic resonance, this concept was studied in detail using the chemical synthesis of constrained sugars adopting unconventional conformations. Pierre Sinaÿ has also discovered and developed a whole series of conceptually new reactions. Selective examples include the synthesis of spiroorthoesters by using selenium chemistry, the development of organometallic chemistry of anomeric carbon, the pioneering synthesis of C-disaccharides, electrochemical glycosylation and, more recently, a novel functionalization of cyclodextrins through a kind of molecular microsurgery in which aluminium derivatives are said to be the scalpel. For the first time, the existence of the glycosyl cation, an intermediate conventionally postulated during glycosylation reactions, could be formally demonstrated through chemistry in a superacid environment. A 4-volume book covers many aspects of carbohydrate chemistry and biology.
Awards and honours
Achille Le Bel Grand Prize of the French Chemical Society (1979)
Pierre Desnuelle Prize from the French Academy of sciences (1996)
Medal of the Berthelot Foundation (1996)
Claude S. Hudson Award in Carbohydrate Chemistry from the American Chemical Society (2007)
Elected Correspondent of the French Academy of sciences (1996)
Honorary doctorate from the University of Lisbon (2005)
Elected member of the French Academy of sciences (2003)
Haworth Memorial Reading and Haworth Medal from the Royal Society of Chemistry (Great Britain, 2011).
Associate Member of the National Academy of Pharmacy (2016).
Chevalier of the Légion d'honneur and Commandeur of the Palmes Académiques.
References
1938 births
20th-century French chemists
Members of the French Academy of Sciences
Living people
21st-century French chemists
People from Seine-Saint-Denis
Academic staff of the University of Orléans
Academic staff of Pierre and Marie Curie University
Sorbonne University
Organic chemists
Knights of the Legion of Honour
Commandeurs of the Ordre des Palmes Académiques | Pierre Sinaÿ | [
"Chemistry"
] | 843 | [
"Organic chemists",
"French organic chemists"
] |
62,286,468 | https://en.wikipedia.org/wiki/GraphBLAS | GraphBLAS () is an API specification that defines standard building blocks for graph algorithms in the language of linear algebra. GraphBLAS is built upon the notion that a sparse matrix can be used to represent graphs as either an adjacency matrix or an incidence matrix. The GraphBLAS specification describes how graph operations (e.g. traversing and transforming graphs) can be efficiently implemented via linear algebraic methods (e.g. matrix multiplication) over different semirings.
The development of GraphBLAS and its various implementations is an ongoing community effort, including representatives from industry, academia, and government research labs.
Background
Graph algorithms have long taken advantage of the idea that a graph can be represented as a matrix, and graph operations can be performed as linear transformations and other linear algebraic operations on sparse matrices. For example, matrix-vector multiplication can be used to perform a step in a breadth-first search.
The GraphBLAS specification (and the various libraries that implement it) provides data structures and functions to compute these linear algebraic operations. In particular, GraphBLAS specifies sparse matrix objects which map well to graphs where vertices are likely connected to relatively few neighbors (i.e. the degree of a vertex is significantly smaller than the total number of vertices in the graph). The specification also allows for the use of different semirings to accomplish operations in a variety of mathematical contexts.
Originally motivated by the need for standardization in graph analytics, similar to its namesake BLAS, the GraphBLAS standard has also begun to interest people outside the graph community, including researchers in machine learning, and bioinformatics. GraphBLAS implementations have also been used in high-performance graph database applications such as RedisGraph.
Specification
The GraphBLAS specification has been in development since 2013, and has reached version 2.1.0 as of December 2023. While formally a specification for the C programming language, a variety of programming languages have been used to develop implementations in the spirit of GraphBLAS, including C++, Java, and Nvidia CUDA.
Compliant implementations and language bindings
There are currently two fully-compliant reference implementations of the GraphBLAS specification. Bindings assuming a compliant specification exist for the Python, MATLAB, and Julia programming languages.
Linear algebraic foundations
The mathematical foundations of GraphBLAS are based in linear algebra and the duality between matrices and graphs.
Each graph operation in GraphBLAS operates on a semiring, which is made up of the following elements:
A scalar addition operator ()
A scalar multiplication operator ()
A set (or domain)
Note that the zero element (i.e. the element that represents the absence of an edge in the graph) can also be reinterpreted. For example, the following algebras can be implemented in GraphBLAS:
All the examples above satisfy the following two conditions in their respective domains:
Additive identity,
Multiplicative annihilation,
For instance, a user can specify the min-plus algebra over the domain of double-precision floating point numbers with GrB_Semiring_new(&min_plus_semiring, GrB_MIN_FP64, GrB_PLUS_FP64).
Functionality
While the GraphBLAS specification generally allows significant flexibility in implementation, some functionality and implementation details are explicitly described:
GraphBLAS objects, including matrices and vectors, are opaque data structures.
Non-blocking execution mode, which permits lazy or asynchronous evaluation of certain operations.
Masked assignment, denoted , which assigns elements of matrix to matrix only in positions where the mask matrix is non-zero.
The GraphBLAS specification also prescribes that library implementations be thread-safe.
Example code
The following is a GraphBLAS 2.1-compliant example of a breadth-first search in the C programming language.
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include "GraphBLAS.h"
/*
* Given a boolean n x n adjacency matrix A and a source vertex s, performs a BFS traversal
* of the graph and sets v[i] to the level in which vertex i is visited (v[s] == 1).
* If i is not reachable from s, then v[i] = 0 does not have a stored element.
* Vector v should be uninitialized on input.
*/
GrB_Info BFS(GrB_Vector *v, GrB_Matrix A, GrB_Index s)
{
GrB_Index n;
GrB_Matrix_nrows(&n,A); // n = # of rows of A
GrB_Vector_new(v,GrB_INT32,n); // Vector<int32_t> v(n)
GrB_Vector q; // vertices visited in each level
GrB_Vector_new(&q, GrB_BOOL, n); // Vector<bool> q(n)
GrB_Vector_setElement(q, (bool)true, s); // q[s] = true, false everywhere else
/*
* BFS traversal and label the vertices.
*/
int32_t level = 0; // level = depth in BFS traversal
GrB_Index nvals;
do {
++level; // next level (start with 1)
GrB_apply(*v, GrB_NULL, GrB_PLUS_INT32,
GrB_SECOND_INT32, q, level, GrB_NULL); // v[q] = level
GrB_vxm(q, *v, GrB_NULL, GrB_LOR_LAND_SEMIRING_BOOL,
q, A, GrB_DESC_RC); // q[!v] = q ||.&& A; finds all the
// unvisited successors from current q
GrB_Vector_nvals(&nvals, q);
} while (nvals); // if there is no successor in q, we are done.
GrB_free(&q); // q vector no longer needed
return GrB_SUCCESS;
}
See also
Basic Linear Algebra Subprograms (BLAS)
LEMON Graph Library
References
External links
GraphBLAS Forum
Numerical linear algebra
Numerical software
Graph description languages | GraphBLAS | [
"Mathematics"
] | 1,349 | [
"Graph theory",
"Mathematical relations",
"Numerical software",
"Graph description languages",
"Mathematical software"
] |
62,286,836 | https://en.wikipedia.org/wiki/Histopathologic%20diagnosis%20of%20dermatitis | Histopathology of dermatitis can be performed in uncertain cases of inflammatory skin condition that remain uncertain after history and physical examination.
Sampling
Generally a skin biopsy:
For punch biopsies, a size of 4 mm is preferred for most inflammatory dermatoses.
Panniculitis or cutaneous lymphoproliferative disorders: 6 mm punch biopsy or skin excision.
A superficial or shave biopsy is regarded as insufficient.
Fixation
Generally: Buffered 4% formaldehyde.
In suspected immunologic disease: Fixation for immunofluorescence, with for example Michel's solution. For details, see immunofluorescense of skin tissues
Staining
Generally 3 sections for H&E staining and one section with periodic acid Schiff (PAS)
If suspected bacterial and fungal microorganisms, consider Gram stain and Gomori methenamine silver stain.
Microscopic evaluation
One approach is to classify into mainly either of the following, primarily based on depth of involvement:
Epidermis, papillary dermis, and superficial vascular plexus:
Vesiculobullous lesions
Pustular dermatosis
Non vesicullobullous, non-pustular
With epidermal changes
Without epidermal changes. These characteristically have a superficial perivascular inflammatory infiltrate, and can be classified by type of cell infiltrate:
Lymphocytic (most common)
Lymphoeosinophilic
Lymphoplasmacytic
Mast cell
Lymphohistiocytic
Neutrophilic
Continue in corresponding section:
Non vesicullobullous, non-pustular lesions with epidermal changes
Spongiotic dermatitis
It is characterized by epithelial intercellular edema.
In addition to above, an unspecific spongiotic dermatitis can be consistent with nummular dermatitis, dyshidrotic dermatitis, Id reaction, dermatophytosis, miliaria, Gianotti-Crosti syndrome and pityriasis rosea.
Interface dermatitis
These are sorted into either:
Interface dermatitis with vacuolar change
Interface dermatitis with lichenoid inflammation
Interface dermatitis with vacuolar change
An interface dermatitis with vacuolar alteration, not otherwise specified, may be caused by viral exanthems, phototoxic dermatitis, acute radiation dermatitis, erythema dyschromicum perstans, lupus erythematosus and dermatomyositis.
Interface dermatitis with lichenoid inflammation
Interface dermatitis with lichenoid inflammation, not otherwise specified, can be caused by lichen planus-like keratosis, lichenoid actinic keratosis, lichenoid lupus erythematosus, lichenoid GVHD (chronic GVHD), pigmented purpuric dermatosis, pityriasis rosea, and pityriasis lichenoides chronica. Unusual conditions that can be associated with a lichenoid inflammatory cell infiltrate are HIV dermatitis, syphilis, mycosis fungoides, urticaria pigmentosa, and post-inflammatory hyperpigmentation. In cases of post-inflammatory hyperpigmentation, it is important to exclude potentially harmful mimics such as a regressed melanocytic lesion or lichenoid pigmented actinic keratosis.
Psoriaform dermatitis
Examining multiple deeper levels is recommended if initial cuts do not correlate well with the clinical history.
Psoriaform dermatitis typically displays:
Regular epidermal hyperplasia, elongation of the rete ridges, hyperkeratosis, and parakeratosis.
Usually:A superficial perivascular inflammatory infiltrate
Often: Thinning of epidermal cells overlying the tips of dermal papillae (suprapapillary plates), and dilated, tortuous blood vessels within these papillae
Further histopathologic diagnosis is performed by the following parameters:
Non vesicullobullous, non-pustular lesions without epidermal changes
Lymphocytic infiltrate
Lymphoeosinophilic infiltrate
Lymphoplasmacytic infiltrate
Mastocytosis
Lymphohistiocytic infiltrate
These include bacterial infections including leprosy, and the sample should therefore be stained with Ziel-Neelsen, acid fast stains, Gomori methenamine silver, PAS, and Fite stains. If negative, an unspecific lymphohistocytic dermatosis may be caused by drug reactions and viral infections.
Neutrophilic infiltrate
Multinucleated giant cells
Foreign bodies indicate a foreign body granuloma.
Specific forms of multinucleated giant cells include the Touton giant cell, which contains a ring of nuclei surrounding a central homogeneous cytoplasm, with foamy cytoplasm surrounding the nuclei. The central cytoplasm (surrounded by the nuclei) may be both amphophilic and eosinophilic.
Notes
Reference list
Sources
Dermatitis
Histopathology | Histopathologic diagnosis of dermatitis | [
"Chemistry"
] | 1,080 | [
"Histopathology",
"Microscopy"
] |
62,287,040 | https://en.wikipedia.org/wiki/Design%20Cities%20%28UNESCO%29 | UNESCO's Design Cities project is part of the wider Creative Cities Network. The Network launched in 2004, and has member cities in seven creative fields. The other fields are: Crafts and Folk Art, Music, Film, Gastronomy, Literature, and Media Arts.
Criteria for UNESCO Design Cities
To be approved as a Design City, cities need to meet a number of criteria set by UNESCO.
Designated UNESCO Design Cities share similar characteristics such as having an established design industry; cultural landscape maintained by design and the built environment (architecture, urban planning, public spaces, monuments, transportation); design schools and design research centers; practicing groups of designers with a continuous activity at a local and national level; experience in hosting fairs, events and exhibits dedicated to design; opportunity for local designers and urban planners to take advantage of local materials and urban/natural conditions; design-driven creative industries such as architecture and interiors, fashion and textiles, jewelry and accessories, interaction design, urban design, sustainable design.
There are 40 Cities of Design:
See also
City of Crafts and Folk Arts
City of Film
City of Gastronomy
City of Literature
City of Music
City of Media Arts
References
UNESCO
Design
Lists of cities | Design Cities (UNESCO) | [
"Engineering"
] | 239 | [
"Design"
] |
62,287,478 | https://en.wikipedia.org/wiki/Shuram%20excursion | The Shuram excursion, or Shuram-Wonoka excursion, is a change in δ13C, or in the ratio of carbon-13 to carbon-12, taking place during the Ediacaran Period. The exact time period of the excursion is debated among scholars, beginning around 573 Ma and ending around 562 or 551 Ma. It was first noticed in the Wonoka Formation in South Australia in 1990 and later in the Clemente Formation of Mexico in 1992 and the Shuram Formation in Oman in 1993. It is the largest negative δ13C excursion in Earth history, and recovery took 50 million years, although the apparent magnitude of the excursion may be distorted due to meteoric water diagenesis.
It is not known what caused the excursion. The Shuram excursion may have played a role in sparking the rise of animals that resulted later in the Cambrian explosion. The oxygen-consuming Ediacara biota experienced a radiation during the isotopic excursion as a response to the transient surplus of oxidants. Microbial blooms of oxygenic phototrophs regulated the recovery of the carbon cycle from the isotopic excursion.
References
Ediacaran
Isotope excursions | Shuram excursion | [
"Chemistry"
] | 238 | [
"Isotope excursions",
"Isotopes"
] |
62,288,336 | https://en.wikipedia.org/wiki/The%20Carpentries | The Carpentries is a nonprofit organization that teaches software engineering and data science skills to researchers through instructional workshops. The Carpentries is made up of three programs areas: Software Carpentry, Data Carpentry and Library Carpentry.
The Carpentries workshops have been run internationally, including workshops at the Smithsonian Institution, the Australian Research Data Commons, CERN, and in Antarctica.
History
Software Carpentry workshops began in 1998 as week-long training courses by Brent Gorda and Greg Wilson. at Los Alamos National Laboratory. The Software Carpentry Foundation was formed in 2014 alongside the sibling foundation, Data Carpentry. These organizations were merged in 2018 to form what is now known as The Carpentries. In 2018, Library Carpentry became the third lesson program of The Carpentries.
Workshops
Carpentries workshops are two-day workshops led by volunteer instructors who have been certified through the organization's training program. Content covered in a standard workshop includes using the command line and an introduction to a programming language such as R or Python. Workshops under the Data Carpentry program focus on specific subject domains, such as life sciences or social sciences.
A Software Carpentry workshop is designed as an active learning and collaborative experience. The lesson content is hands-on with practice following instructors live coding, while helpers are ready to assist students and keep the class pace. Training covers the core skills needed to be productive in a small research team. Tutorials in the lesson alternate with practical exercises, where collaboration is attempted. There is a collaborative document where the learning process is constructed.
Lessons
Stable lessons
All lesson content under The Carpentries curriculum are licensed openly under Creative Commons licenses.
Before being adopted as an official Carpentries lesson, new lessons go through a series of stages designed to ensure they are sufficiently documented to be teachable by instructors outside of the initial author group.
The Carpentries shares The Carpentries Community Developed Lessons (there are three core topics: the Unix shell, version control with Git, and a programming language (Python or R). Curricula for these lessons in English and Spanish (select lessons only) and also Data Carpentry's lessons.
Community developed lesson
The Carpentries community has a collaborative and open process for lesson development and to sharing teaching materials. The Carpentries incubator contains lessons developed by community members. These lessons follow a life cycle that begins with pre-alpha, where only the concept is offered, and ends with beta, where the lesson is taught in a workshop by instructors other than the authors. There are 4 stages: pre-alpha, alpha, beta, and stable.
Pre-alpha is the draft from the initial lesson idea. Alphas goal is to collect and incorporate feedback from learners and co-instructor. The two lessons in beta stages are Reproducible Computational Environments using Containers and Data Harvesting for Agriculture.
Carpentries incubator has approximately 30 lessons available in alpha stage, ranging from a spreadsheet to a database through Python for Humanities and Metagenomics. There is another main way for community members to share lessons material: The CarpentriesLab, which is a repository for high-quality, peer-reviewed, short-format, lessons that use the teaching approach and lesson design from The Carpentries. It is also possible to get peer-review on the content of a lesson by submitting it to The Incubator through Carpentries.
The lessons from both Carpentries Incubator and CarpentriesLab can be taught in meetups, classes or as complements to a standard two-day Carpentries workshop.
Other language lessons
The Carpentries community has developed Spanish versions of its core lessons which are the Unix shell, version control with Git and R as a programming language.
Funding
The Carpentries is fiscally sponsored by Community Initiatives and funded through a combination of memberships, workshop fees, grants and donations. The Carpentries has over 70 member organizations, including the Software Sustainability Institute, the National Institute of Standards and Technology, New Zealand eScience Infrastructure, and Compute Canada.
Library Carpentry was seed funded in 2015 by a small grant from the Software Sustainability Institute. In November 2017, the Library Carpentry program received a supplemental Institute of Museum and Library Services grant, in partnership with the California Digital Library, valued at $249,553.
In November 2019, the Chan Zuckerberg Initiative and the Gordon and Betty Moore Foundation announced a joint award of $2.65 million for The Carpentries.
References
1998 establishments in California
Organizations established in 2014
Non-profit organizations based in California
Educational organizations based in the United States
Information technology organizations | The Carpentries | [
"Technology"
] | 952 | [
"Information technology",
"Information technology organizations"
] |
62,288,792 | https://en.wikipedia.org/wiki/Electronic%20badge | An electronic badge (or electronic conference badge) is a gadget that is a replacement for a traditional paper-based badge or pass issued at public events. It is mainly handed out at computer (security) conferences and hacker events. Their main feature is to display the name of the attendee, but due to their electronic nature they can include a variety of software. The badges were originally a tradition at DEF CON, but spread across different events.
Examples
Hardware
SHA2017 badge, which included an e-ink screen and an ESP32
Card10 for CCCamp2019
Electromagnetic Field Camp badge
Software
The organization badge.team has developed a platform called "Hatchery" to publish and develop software for several badges.
References
Computer hardware
Hacker culture | Electronic badge | [
"Technology",
"Engineering"
] | 150 | [
"Computer engineering",
"Computer hardware",
"Computer systems",
"Computer science",
"Computers"
] |
62,288,906 | https://en.wikipedia.org/wiki/Living%20DNA | Living DNA is a UK-based company that specialises in DNA testing and analysis whose head office is in the UK with facilities in the USA and Denmark. The service is to provide deep ancestry details from all around the world, using a unique process of analysis and using linked DNA. It is one of the major DNA testing services in the world. The company conducts three types of DNA analyses: autosomal, Y-chromosome and mitochrondrial. However, while the DNA test results provide information about the origins of a person, genealogy, i.e. finding relatives in historic time, is not yet part of the company's portfolio.
History and partnership
In 2016, Living DNA was co-founded by Tricia Nicholson and husband-and-wife team, David Nicholson and Hannah Morden-Nicholson, in Frome, Somerset, England. The company began after extensive research and work along with a team of around 100 genealogists around the world. In 1999 Nicholson founded another company, DNA Worldwide, which he has been running since.
In July 2018, Living DNA announced and signed a partnership agreement with Findmypast, also a British genealogy company. By working together, their mission was to provide an extensive and detailed family roots and history. Unfortunately, this partnership ended in 2023.
In 2019, Living DNA was reported to provide, for each DNA sample tested, recent (less than 80,00 years) ethnic breakdown for 80 regions in the world with the UK broken down in to 21 regions. They also provided insight into female and paternal (for males) heritage going back about 200,000 years showing migration patterns out of Africa.
DNA privacy concerns
Research published in the scientific journal eLife by geneticist Michael Edge from the University of California uncovered security concerns with customers DNA data held online by the smaller genealogy companies, including Living DNA. It was found that hackers using creative means could easily exploit these upload-based services. Biostatistician Sharon Browning from the University of Washington said that if consumers "care about their DNA's privacy, then they shouldn't upload [their DNA] to these databases."
Critics and reviews
Living DNA has gotten a positive review from PCWorld. Tech Radar commented that "..the vagueness of some of its results combined with its relatively high price mean it doesn’t stand out from the crowd."
After getting DNA tests results from three different companies to know if his "dad's family came from Russia", David Gewirtz says, "the results I got back from Ancestry and 23andMe were shocking and upsetting would be an understatement." However, "the results from Living DNA were substantially different and led to some fascinating insights that were actually really cool, rather than painful."
Controversy surrounding key people
Director Hannah Morden-Nicholson, stepped down from the Frome Chamber of Commerce committee in early 2019 after being associated with a locally established "cult" Universal Medicine. This followed on from a BBC investigation into the "socially harmful" group. Co-director David Nicholson is also dedicated to the sect and its leader’s teachings, and ex-director and co-founder Tricia Nicholson declares a 'lifelong family friendship' with the sect's leader.
References
External links
Company listing at the International Society for Genetic Genealogy Wiki
Ancestry DNA Testing Reviews for LivingDNA
British genealogy websites
Companies based in Somerset
Genetic genealogy companies
Online companies of the United Kingdom
Applied genetics
Biotechnology companies of the United Kingdom
Biotechnology companies established in 2016
Biological databases
Privately held companies of England
2016 establishments in England
British companies established in 2016 | Living DNA | [
"Biology"
] | 727 | [
"Bioinformatics",
"Biological databases"
] |
62,289,071 | https://en.wikipedia.org/wiki/Rebag | Rebag is a New York-based retail platform, established in 2014, that operates both online and through brick-and-mortar stores. It specializes in the buying, trading, and selling of luxury handbags, accessories, watches, fine jewelry, shoes, and select apparel.
History
Rebag was established in 2014 by CEO Charles Albert Gorra under the parent company Trendly Incorporated. It functions as a digital and brick-and-mortar retail platform where customers can engage in the buying and selling of luxury designer handbags, accessories, watches, fine jewelry, shoes, and select apparel.
Rebag's inventory encompasses approximately 99 luxury brands, including well-known names such as Louis Vuitton, Hermès, Chanel, Prada, Cartier, Tiffany & Co., Rolex, Rick Owens, Maison Margiela, Christian Louboutin, and Gucci. Customers have the option to shop either online or in-store.
Since its establishment in 2014, the company has secured approximately $52 million in venture capital funding, with leading investors including General Catalyst, Novator, and FJ Labs.
In 2024, the company launched a pay now, buy later membership program.
Locations
Based in New York City, Rebag currently manages nine brick-and-mortar stores. These include four in New York City (Soho, Madison Avenue, Westfield World Trade Center, and The Shops at Columbus Circle), two in the Los Angeles metro area (Beverly Hills and Westfield Santa Anita), two in Miami (Brickell City Centre and Dadeland Mall) and one in Greenwich, Connecticut.
The initial location in Soho, NYC, was initially conceived as a pop-up but later transitioned into a permanent flagship location. The design of the physical locations was orchestrated by Red Antler.
Another standalone store, known as Rebag Bar, was opened in NYC to adapt to changes in customer shopping behavior during the pandemic. At Rebag Bar, customers have the opportunity to swiftly sell their pre-owned luxury goods and browse for secondhand items.
Products
CLAIR by Rebag
An acronym for the Comprehensive Luxury Assessment Index for Resale, CLAIR is a data-driven evaluation software tool developed and launched by Rebag in 2019. It is designed to provide instant valuation of both new and pre-owned luxury handbags. It has been likened to the "Kelley Blue Book of Resale."
Rebag Infinity
Rebag Infinity is a program offered by Rebag that enables customers to purchase a bag and use it for up to six months. After this period, customers can exchange the bag for store credit, which is valued at a minimum of 70 percent of the bag's original purchase price. This credit can then be applied towards the purchase of a new bag.
Trade
Rebag provides the Trade option, which enables customers to buy and sell pre-owned luxury handbags, watches, accessories, fine jewelry, shoes, and select apparel. Through this option, customers can trade their once-loved items for credit, which can be applied towards their purchase on the same day.
Awards
One of Fast Company’s 10 Most Innovative Retail Companies of 2021
Glossy 2021 Award for Fashion Retailer of the Year
Nominations
2019 Glossy Awards - Best Breakthrough Startup, Fashion
Accolades
''Instyles "Best Places to Resell Designer Handbags Online"
Town & Country’s "10 Best Ethical and Sustainable Fashion and Accessory Brands"
Who What Wear's "Best Resale Sites to Know"
W Magazine'''s "The 10 Best Online Vintage Shopping Sites"Fast Companys "The 10 most innovative style companies of 2020"
References
American companies established in 2014
Retail companies established in 2014
Internet properties established in 2014
Online retailers
Online marketplaces of the United States
E-commerce | Rebag | [
"Technology"
] | 755 | [] |
62,289,299 | https://en.wikipedia.org/wiki/Pavel%20Winternitz | Pavel Winternitz (July 25, 1936 – February 13, 2021) was a Canadian Czech-born mathematical physicist. He completed undergraduate studies at Prague University
and received a doctorate from Leningrad University (Ph.D. 1962) under the supervision of J. A. Smorodinsky.
His research is on integrable systems and symmetries.
He was a member of the Mathematical Physics group at the Centre de recherches mathématiques (CRM), a national research centre in mathematics at the Université de Montréal and Professor in the Department of Mathematics and Statistics at Université de Montréal.
His work has had a strong impact in several domains of mathematical physics, and his publications are very widely cited.
In 2001, he was recipient of the CAP-CRM Prize in Theoretical and Mathematical Physics
.
In 2018, he was recipient of the Wigner medal.
He died on 13 February 2021.
References
External links
Centre de recherches mathématiques
P Winternitz publications in Google Scholar
Canadian physicists
Mathematical physicists
Theoretical physicists
Canadian mathematicians
Scientists from Prague
20th-century Canadian physicists
21st-century Canadian scientists
1936 births
20th-century Canadian mathematicians
2021 deaths | Pavel Winternitz | [
"Physics"
] | 235 | [
"Theoretical physics",
"Theoretical physicists"
] |
62,290,105 | https://en.wikipedia.org/wiki/Serre%27s%20inequality%20on%20height | In algebra, specifically in the theory of commutative rings, Serre's inequality on height states: given a (Noetherian) regular ring A and a pair of prime ideals in it, for each prime ideal that is a minimal prime ideal over the sum , the following inequality on heights holds:
Without the assumption on regularity, the inequality can fail; see scheme-theoretic intersection#Proper intersection.
Sketch of Proof
Serre gives the following proof of the inequality, based on the validity of Serre's multiplicity conjectures for formal power series ring over a complete discrete valuation ring.
By replacing by the localization at , we assume is a local ring. Then the inequality is equivalent to the following inequality: for finite -modules such that has finite length,
where = the dimension of the support of and similar for . To show the above inequality, we can assume is complete. Then by Cohen's structure theorem, we can write where is a formal power series ring over a complete discrete valuation ring and is a nonzero element in . Now, an argument with the Tor spectral sequence shows that . Then one of Serre's conjectures says , which in turn gives the asserted inequality.
References
Commutative algebra | Serre's inequality on height | [
"Mathematics"
] | 253 | [
"Fields of abstract algebra",
"Commutative algebra"
] |
62,292,920 | https://en.wikipedia.org/wiki/Vera%20Rubin%20Early%20Career%20Prize | The Vera Rubin Early Career Prize is named after Vera Rubin and is awarded by the Division on Dynamical Astronomy of the American Astronomical Society. The prize recognizes excellence in dynamical astronomy. Recipients must have received their doctorate no more than ten years prior.
Winners
See also
List of astronomy awards
References
Astronomy prizes
American Astronomical Society
Early career awards | Vera Rubin Early Career Prize | [
"Astronomy",
"Technology"
] | 67 | [
"Science and technology awards",
"Science award stubs",
"Astronomy prizes",
"Astronomy stubs"
] |
62,293,001 | https://en.wikipedia.org/wiki/Inverse%20depth%20parametrization | In computer vision, the inverse depth parametrization is a parametrization used in methods for 3D reconstruction from multiple images such as simultaneous localization and mapping (SLAM). Given a point in 3D space observed by a monocular pinhole camera from multiple views, the inverse depth parametrization of the point's position is a 6D vector that encodes the optical centre of the camera when in first observed the point, and the position of the point along the ray passing through and .
Inverse depth parametrization generally improves numerical stability and allows to represent points with zero parallax. Moreover, the error associated to the observation of the point's position can be modelled with a Gaussian distribution when expressed in inverse depth. This is an important property required to apply methods, such as Kalman filters, that assume normality of the measurement error distribution. The major drawback is the larger memory consumption, since the dimensionality of the point's representation is doubled.
Definition
Given 3D point with world coordinates in a reference frame , observed from different views, the inverse depth parametrization of is given by:
where the first five components encode the camera pose in the first observation of the point, being the optical centre, the azimuth, the elevation angle, and the inverse depth of at the first observation.
References
Bibliography
Computer vision | Inverse depth parametrization | [
"Engineering"
] | 273 | [
"Artificial intelligence engineering",
"Packaging machinery",
"Computer vision"
] |
70,428,261 | https://en.wikipedia.org/wiki/2022%20United%20Nations%20Biodiversity%20Conference | The 2022 United Nations Biodiversity Conference of the Parties (COP15) to the UN Convention on Biological Diversity (CBD) was a conference held in Montreal, Canada, which led to the international agreement to protect 30% of land and oceans by 2030 (30 by 30) and the adoption of the Kunming-Montreal Global Biodiversity Framework.
History
The conference was originally scheduled to be held in October 2020, but was delayed due to the COVID-19 pandemic. It was rescheduled to be held in April 2022 in Kunming, China, but was postponed again, for a fourth time due to China's zero-COVID policy, to the third quarter of 2022 according to the UN secretariat office on March 29. In May 2022, China requested Canada to assume the host responsibility. The Canadian Minister of Environment and Climate Change Steven Guilbeault met with representatives from the High Ambition Coalition in early June 2022 and these representatives asked Canada to host COP15. The Prime Minister of Canada Justin Trudeau approved the proposal. In June 2022, the UN secretariat for the Convention on Biological Diversity and China's environment ministry said in separate statements that the meeting would be held in December 2022 in Montreal, Canada, where the secretariat is based, though China would remain the president of the summit. This arrangement is consistent with previous practices of moving the meeting to a different country, such as the 2017 United Nations Climate Change Conference (Fiji held the presidency while Germany organized the meeting for practical purpose) and the 2019 United Nations Climate Change Conference (Chile maintained the presidency despite the meeting being moved to Spain due to political instability in Chile). While the host countries of previous COPs had one to two years to organize the conference, Canada had just five months to prepare for the arrival of 18,000 delegates from 196 CBD member states, non-governmental organizations, industry groups and academia.
This is the second time Montreal served as the host city for a UN Conference of Parties meeting, the first time being the COP11 climate change conference in 2005. Montreal also played host to the negotiations for the Montreal Protocol.
Development
Lead-up
Several cities signed the "Montreal Pledge" in advance of the conference to commit to protect biodiversity in their cities through 15 actions.
Negotiations and adoption
During the talks, divisions remained on numerous issues as the conference went into its final days, such as disputes over the funding for conservation efforts. There was also discussion that protections for marine biodiversity could be dropped completely. An op-ed published in The Guardian in mid-December criticized the proceedings as being very slow and lacking urgency.
On December 19, almost every country on earth signed onto the agreement which includes protecting 30% of land and oceans by 2030 (30 by 30) and 22 other targets intended to reduce biodiversity loss. When the agreement was signed only 17% of land territory and 10% of ocean territory were protected. The agreement includes protecting the rights of indigenous peoples and changing the current subsidy policy to a one better for biodiversity protection. However, it makes a step backward in protecting species from extinction in comparison to the Aichi Targets. Some countries said the agreement does not go far enough to protect biodiversity, and that the process was rushed. Only the United States and the Holy See did not join it. The absence of the United States signature weakened the agreement. However, the country helped to reach the agreement, strongly advanced some of the targets mentioned in it, especially 30 by 30, nationally and internationally and is a major donor to biodiversity protection issues.
Content
In addition to protecting 30% of land and oceans by 2030, the agreement includes also recovering 30% of earth degraded ecosystems and increasing funding for biodiversity issues. Other targets for the year 2030 include cutting overconsumption and waste, reducing food waste by 50%, and completely stop harming ecosystems that are strongly important for biodiversity. There are also 4 targets for the year 2050 which includes increasing the area of natural ecosystems, restoring their integrity and normal functioning, reducing tenfold the human caused extinction rate, and protecting traditional knowledge.
COP15 adopted a comprehensive package of 6 items:
L25: Kunming-Montreal Global Biodiversity Framework (GBF)
L26: Monitoring framework for the Kunming-Montreal Global Biodiversity Framework
L27: Mechanisms for planning, monitoring, reporting and review
L28: Capacity-building and development and technical and scientific cooperation
L29: Resource mobilization
L30: Digital sequence information on genetic resources.
The advocacy of the UNCBD Women's Cacus and its members
led to a Rio Convention for the first time in its 30-year history to adopt a stand-alone target, Target 23, on gender equality in the Kunming-Montreal Global Biodiversity Framework.
See also
Global Assessment Report on Biodiversity and Ecosystem Services
2024 United Nations Biodiversity Conference
References
External links
COP15: The UN Biodiversity Conference
The 15th Conference of Parties (COP15) to the Convention on Biological Diversity (CBD) official documents
Biodiversity
History of Kunming
United Nations conferences on the environment
Convention on Biological Diversity
2022 in the environment
Events postponed due to the COVID-19 pandemic
2022 in international relations
Events in Montreal
Diplomatic conferences in Canada
China and the United Nations
Canada and the United Nations
December 2022 events in Canada
2022 in Quebec | 2022 United Nations Biodiversity Conference | [
"Biology"
] | 1,065 | [
"Convention on Biological Diversity",
"Biodiversity"
] |
70,431,253 | https://en.wikipedia.org/wiki/WHL0137-LS | WHL0137-LS, also known as Earendel, is a star located in the constellation of Cetus. Discovered in 2022 by the Hubble Space Telescope, it is the earliest and most distant known star, at a comoving distance of 28 billion light-years (8.6 billion parsecs). The previous farthest known star, MACS J1149 Lensed Star 1, also known as Icarus, at a comoving distance of , was discovered by Hubble in 2018. Stars like Earendel can be observed at cosmological distances thanks to the large magnification factors afforded by gravitational lensing, which can exceed 1,000. Other stars have been observed through this technique, such as Godzilla.
Observation
Earendel's discovery by the Hubble Space Telescope was reported on 30March 2022. The star was detectable due to gravitational lensing caused by the presence of the galaxy cluster WHL0137-08 between it and the Earth, concentrating the light from the star. Computer simulations of the lensing effect suggest that Earendel's brightness was magnified between one thousand and forty thousand times. The dates of Hubble's exposure to the star's light were 7June 2016, 17July 2016, 4November 2019, and 27November 2019.
The star was nicknamed Earendel by the discoverers, derived from the Old English name for 'morning star' or 'rising light'. Eärendil is also the name of a half-elven character in one of J. R. R. Tolkien's books, The Silmarillion, who travelled through the sky with a radiant jewel that appeared as bright as a star. NASA astronomer Michelle Thaller confirmed that the reference to Tolkien was intentional. The star's host galaxy, WHL0137-zD1, was nicknamed "Sunrise Arc", because gravitational lensing distorted its light into a long crescent.
Further observations by Hubble and the James Webb Space Telescope have been proposed to better define the properties of the star. James Webb's higher sensitivity is expected to allow the analysis of Earendel's stellar spectra and determine whether it is actually a single star. The spectral analysis would reveal the presence of elements heavier than hydrogen and helium, if any.
On 30 July 2022, an image of Earendel was captured by the James Webb Space Telescope during its first imaging campaign of the star.
On 8August 2023, the colors of Earendel were detected, and an image was captured by both the Hubble and Webb telescopes. Based on Webb's NIRCam data, Earendel is a "massive B-type star more than twice as hot as our Sun, and about a million times more luminous". Webb's observations, particularly through the Near-Infrared Camera, revealed intriguing details, including hints of a cooler, redder companion star. This discovery offers insights into the universe's distant past, mirroring the early stages of galactic evolution.
Physical properties
The light detected from Earendel was emitted 900 million years after the Big Bang. The star has been determined to have a redshift, meaning the light from Earendel reached Earth 12.9 billion years later. Due to the expansion of the universe, the star's observed position is now 28 billion light-years away. The previous most distant star, MACS J1149 Lensed Star 1, has a redshift of 1.49, and is now 14.4 billion light-years away.
If it is a single star, Earendel has a temperature of 13,000 – 16,000 K and a luminosity of 631,000 – 3,981,000 , depending on the magnification. It is possible that Earendel might not be a single star as the spectral energy distribution of Earendel has a strong Balmer break, which is characteristic of stars with temperatures below 13,000 K and a blue UV slope which is present in stars with temperatures above 20,000 K. It is possible that Earendel is a binary with two components, where one is more luminous and much hotter (34,000 K) than the other one (9,000 K). Due to the limited amount of data, the parameters are not well constrained. If two stars are in the system, they could have different magnifications, which makes the parameters even more uncertain.
See also
List of star extremes
List of the most distant astronomical objects
Nature timeline
References
20220330
Cetus
Hubble Space Telescope
Intergalactic stars
Luminous blue variables
Extragalactic stars | WHL0137-LS | [
"Astronomy"
] | 956 | [
"Cetus",
"Constellations"
] |
70,432,824 | https://en.wikipedia.org/wiki/Diselenolene%20metal%20complexes | 1,2-Diselenolene metal complexes are a class of coordination compounds homologous to 1,2-dithiolene metal complexes and formally deriving from ene-1,2-diselenolato ligands.
1,2-Diselenolene (DSE) is a versatile ligand that forms complexes with various transition metals. The term refers to the metal complexes containing at least one five-membered heterocyclic molecule that contains two adjacent selenium atoms in a planar, anti-aromatic ring system.
One of the earliest examples of DSE metal complexes was reported by Davison and Shawl. Since then, several other transition metals such as palladium, platinum, gold, and nickel have been shown to form complexes with DSE.
The synthesis of DSE metal complexes is typically achieved by the reaction of a DSE proligand with a metal precursor in the presence of a suitable reducing agent. The choice of reducing agent depends on the oxidation state of the metal ion and the desired redox properties of the complex.
The characterization of DSE metal complexes is typically performed by a combination of spectroscopic and electrochemical techniques. Infrared and Raman spectroscopy can be used to identify the vibrational modes of the ligand and the metal-ligand bonds. X-ray crystallography can provide valuable information about the molecular structure and bonding in the complex. Electrochemical techniques such as cyclic voltammetry and differential pulse voltammetry can be used to determine the redox properties of the complexes.
The electronic properties of DSE metal complexes can be tuned by varying the metal center and the substitution pattern on the DSE ligand. For example, the replacement of one or both selenium atoms with sulfur or tellurium can alter the electronic properties of the complex. The substitution of alkyl or aryl groups on the DSE ligand can also affect the redox properties and stability of the complex.
In recent years, there has been growing interest in the use of DSE metal complexes as catalysts for organic transformations. For example, the palladium complex [Pd(DSE)2] has been shown to be an effective catalyst for the Suzuki-Miyaura cross-coupling reaction. The platinum complex [Pt(DSE)2] has been used as a catalyst for the oxidation of alcohols and the reduction of nitroarenes. The unique electronic properties of DSE metal complexes make them promising candidates for catalytic applications in a wide range of organic transformations.
In addition to their potential applications in catalysis, DSE metal complexes also exhibit interesting optoelectronic properties. For example, the palladium complex [Pd(DSE)2] has been shown to exhibit photoluminescence in the solid state. The gold complex [Au(DSE)2] has been used as a building block for the construction of luminescent materials. The unique electronic properties of DSE metal complexes make them promising candidates for applications in optoelectronics and photonics.
Non-innocence
In addition to the unique structural and electronic properties of 1,2-diselenolene metal complexes, their behavior as redox-active ligands has also been a subject of recent investigation. The term "non-innocent" has been used to describe ligands that undergo changes in oxidation state or electronic configuration upon coordination to a metal center, which can dramatically impact the reactivity and properties of the resulting complex.
Several studies have demonstrated the non-innocence of 1,2-diselenolene ligands in their metal complexes. For example, the coordination of a 1,2-diselenolene ligand to a metal center can result in significant changes in the ligand's redox potential. In some cases, the ligand can become reduced upon coordination, leading to the formation of metal-ligand radical species. These radicals can then participate in a variety of redox processes, including the oxidation or reduction of other ligands or substrates.
Non-innocent behavior has also been observed in the reactivity of 1,2-diselenolene metal complexes towards small molecules such as O2 and CO2. In some cases, coordination of these molecules to the metal center can induce changes in the electronic structure of the 1,2-diselenolene ligand, leading to the formation of reactive intermediates. These intermediates can then participate in a range of chemical reactions, including the activation of O2 for selective oxidation reactions.
In addition to their redox and reactivity properties, 1,2-diselenolene metal complexes have also been investigated for their potential applications in areas such as catalysis, materials science, and electronics. For example, the unique electronic and optical properties of these complexes have led to their use as building blocks for the development of new organic electronic materials, such as OLEDs and solar cells.
Furthermore, the non-innocence of 1,2-diselenolene ligands has been exploited for the development of novel catalytic systems. For instance, the use of 1,2-diselenolene-based ligands in transition metal catalysts has been shown to improve the selectivity and activity of a variety of catalytic reactions, including olefin polymerization and cross-coupling reactions.
Overall, the combination of unique structural and electronic properties, as well as non-innocent behavior, make 1,2-diselenolene metal complexes a promising class of compounds for a wide range of applications in chemistry and materials science. Continued investigation into the fundamental properties and reactivity of these compounds is likely to lead to further discoveries and innovations in these fields.
References
Selenium compounds
Heterocyclic compounds
Transition metal compounds | Diselenolene metal complexes | [
"Chemistry"
] | 1,157 | [
"Organic compounds",
"Heterocyclic compounds"
] |
70,433,138 | https://en.wikipedia.org/wiki/Plastic%20degradation%20by%20marine%20bacteria | Plastic degradation in marine bacteria describes when certain pelagic bacteria break down polymers and use them as a primary source of carbon for energy. Polymers such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) are incredibly useful for their durability and relatively low cost of production, however it is their persistence and difficulty to be properly disposed of that is leading to pollution of the environment and disruption of natural processes. It is estimated that each year there are 9-14 million metric tons of plastic that are entering the ocean due to inefficient solutions for their disposal. The biochemical pathways that allow for certain microbes to break down these polymers into less harmful byproducts has been a topic of study to develop a suitable anti-pollutant.
Adaptive pressures
With the increasing presence of plastics in the environment, certain species of bacteria have evolved to degrade plastics into harmless by-products. Since the 20th century, microbes have evolved to degrade plastics, as the global production of plastics steadily increased from 2 million metric tons to 380 million metric tons per year. A study performed in 2021, led by Jan Zrimec of the National Institute of Biology in Slovenia, was able to isolate 30,000 non-redundant enzyme homologues from more than 200 million genes in DNA samples obtained from the environment capable of degrading 10 different types of plastics.
The results showcased the impact of plastic pollution on the microbial environment and the tendency of microbes to adapt to a rapidly changing situation. A strong correlation can be seen between the microbial potential to degrade plastics and the content of global plastic pollution. Of the 30,000 enzyme homologues isolated, 12,000 were found in samples from the ocean. Region-specific analyses show that plastic degrading enzymes were found in high concentrations in deeper areas of the ocean where plastic pollution was more common.
Metabolism
Diversity
With over 5000 grades of plastic polymers and variations in coatings such as flame retardants and pigments, diverse plastic polymer substrates suggest the existence of very heterogenous metabolic processes in plastic degradation. Dynamic ocean conditions ranging in humidity, temperature, UV irradiation, pH, wind, and waves, create varied growth conditions for bacteria and increase the possibility of diversified plastic degradation metabolisms.
Mechanisms
As a developing topic, few studies have characterized the metabolic and biochemical mechanisms involved in the degradation of plastic by marine microbes. A limited number of plastic degradation pathways in marine microbes have been extensively studied. It is important to note that although several metabolic processes in plastic degradation have been well-documented, these processes are likely not representative of the microbial population capable of plastic degradation. Additionally, reaction times of plastic biodegradation metabolisms are poorly understood and are estimated to range between 1–400 hours in the marine environment.
Polyethylene (PE)
Bacteria capable of polyethylene degradation have been described to utilize oxygenase to initiate biodegradation. The formation of alcohol groups through oxygenase makes polyethylene more labile for degradation. The hydrophilic properties of polyethylene polymers increase as the material experiences degradation and oxidation, which causes polyethylene to become less recalcitrant. Lipases, esterase, endopeptidases, and other extracellular enzymes then further degrade the polyethylene polymers. The role of laccase in polyethylene degradation by Rhodococcus ruber is well-documented as an important enzyme for biodegradation. Alkane hydroxylase is thought to play a similar role in pseudomonas species capable of polyethylene degradation. Once enzymes degrade polyethylene polymers into oligomers, microbial cells uptake the molecules through either Major Facilitator Superfamily proteins or ATP binding cassettes. The polyethylene oligomers are converted into Acetyl-CoA and succinyl-CoA and enter the tricarboxylic acid cycle, and eventually the respiratory chain to produce ATP.
Polyethylene Terephthalate (PET)
Aromatic rings in the structure of polyethylene terephthalate pose challenges for microbial biodegradation. Despite the challenge of degrading aromatic rings, several microbes are documented to use polyethylene terephthalate as a sole energy and carbon source. Microbes that utilize PET degradation first adhere to the substrate surface and release enzymes such as hydrolases and cutinases. Following the activity of enzymes like MHETase, molecules from PET degradation are taken up by active transport into bacterial cells. As demonstrated in Figure 2, transported PET molecules consist of terephthalic acid and ethylene glycol, monomers of PET. Certain microbes can use these monomers as their primary carbon source leading to PET degradation. The most relevant pathways related to the degradation of the monomer ethylene glycol are the acetaldehyde/ethanol pathway and the glyoxylic acid pathway. The glyoxylic acid pathway is commonly studied in the Pseudomonas genus as many species such as P. putida are known to be highly capable of degrading polyethylene in aquatic environments. Following a series of chemical processes, the terephthalic acid is converted into 4-carboxy-2-hydroxymuconic, which is a precursor molecule to the TCA cycle and eventually converted into pyruvate and oxaloacetate. Several bacterial species in Betaproteobacteria, Myxococcota (formerly included in Deltaproteobacteria), and Gammaproteobacteria are capable of PET Biodegradation.
Polystyrene (PS)
Polystyrene consists of molecules with both strong hydrophobicity and a high molecular weight. Bacteria that are capable of degrading this molecule are documented to release monooxygenases to initiate the oxidization of polystyrene molecules. Following the monooxygenase step, the polystyrene molecule is transformed into phenylacetic acid during the upper pathway of styrene metabolism. Phenylacetic acid is first converted into phenylacetyl-coA, and later acetyl-CoA and succinyl-CoA after a series of enzymatic reactions. Acetyl-CoA and succinyl-CoA then enter the tricarboxylic acid cycle. Several Rhodococcus ruber strains are capable of polystyrene biodegradation.
Polyhydroxyalkanoate (PHA)
Polyhydroxyalkanoate (PHA) is a polyester that is naturally produced by various microorganisms in response to nutrient limitation and environmental stress. Although polyhydroxyalkanoates have a microbial origin and are often exploited for commercial use, the polymer is also biodegraded by several species of bacteria. Polyhydroxyalkanoate biodegradation is reported to occur in various environments including marine habitats. The biodegradation process of polyhydroxyalkanoate varies between bacterial species that both produce and degrade polyhydroxyalkanoate, and species that only degrade polyhydroxyalkanoate. Species that cannot produce polyhydroxyalkanoate but are capable of polyhydroxyalkanoate degradation initiate hydrolysis of the substrate externally with ectoenzymes that yield hydroxybutyrate. The resulting oligomers cross bacterial membranes through passive diffusion in a form that can directly enter β-oxidation to yield acetyl-CoA. The resulting acetyl-CoA then enters the TCA cycle. Several bacterial species in the genera Gracilibacillus, Enterobacter, and Bacillus are capable of polyhydroxyalkanoate biodegradation.
Challenges
Literature frequently discusses the biological constraints that organisms must overcome to degrade plastic. Features that make plastic challenging to degrade include long-chain polymers, high molecular weight, hydrophobicity, and crystallinity. Although hydrocarbons found in plastic are potential sources of carbon and energy for bacteria, the lack of essential nutrients like nitrogen in plastic make it insufficient to support microbial growth without additional nutrient sources.
Species
Impact
According to the National Ocean Service, it is estimated that there are 8 million metric tons of plastic in the ocean. Ocean plastic affects many marine species in the form of whole plastic and micro plastics. Since the discovery of bacteria that can feed on plastic, there has been hope that these microbes could help clean the ocean of plastic, but Ramani Narayan, a professor in chemical engineering at Michigan State University says that this viewpoint misses the point. Moreover, after Kale et al. performed an extensive review of all data available on these bacteria, they have found that there are currently no practical industrial applications of these microbes in environments to make a substantial impact on the plastic problem in the ocean. This can be attributed to findings that have found the rate of degradation by these microbes to be low, even when optimized in laboratory settings. Hence, researchers at the University of Portsmouth have been working on genetically engineering these bacteria to be more efficient at degrading the plastic.
Genetic engineering
Scientists are working on genetically engineering Ideonella sakaiensis to break down PET plastic at a faster rate in order to make it a viable option to help recycle plastic. Researchers at the University of Portsmouth have discovered that mixing PETase with a second enzyme called MHETase has created an “enzyme cocktail” that degrades PET plastic at 6 times the rate it did before. In an interview done by Bloomberg QuickTake, Professor John McGeehan, who worked with the team at the University of Portsmouth to make this discovery, spoke of the possibility to create an enzyme powder that could be distributed across plastic recycling facilities to break down plastics to their constituent components, Ethylene Glycol and Terephthalic Acid. These building blocks could then be used to make new plastics, which would create a more efficient and effective way of recycling plastics. However, Dr. Hermann J. Heipieper from the Helmholtz Center for Environmental Research does not see this as a viable option due to the high bond strength found in plastic.
Another major part of the research being done on microbial environmental remediation involves manipulating the genomes of specific microbes to increase their metabolic power. For example, in Pseudomonas putida, scientists have engineered a strain to overexpress glc and glcDEF, operons that contain genes coding for enzymes that convert toxic intermediates into the next substrates in the pathway. This would allow plastic monomers such as ethylene glycol to be converted into high-value chemicals such as medium-chain-length polyhydroxyalkanoates (mcl-PHA). As a natural bioplastic, PHAs have similar properties to synthetic plastics and are biodegradable as well as nontoxic making them useful for biomedical applications. Its utility even extends to its potential for the production of hydrocarbon jet fuel if further chemically catalyzed.
Genetically engineered bacteria also do not have a practical application in the ocean, yet, according to the Ocean Conservatory group. Dr. Naryan believes that releasing genetically engineered bacteria into the ocean ecosystems could be irresponsible and have many negative side effects on the ecosystem. As the Ocean Conservatory group states, the solution to the plastic problem does not lie in genetically engineered bacteria, but rather decreasing the plastic input into the ocean and increasing collection and recycling efforts.
With these potential limitations in mind, a deeper comparison of the pros and cons of engineering microbes for plastic degradation should be conducted. As mentioned, one problem in environmental remediation of plastics is that only 30% of plastics are collected to be recycled. Without efficient collection in the first place, the high energy cost of enzymatic recycling would be more burdening than the amount of waste it would break down. Another problem includes the fact that this may not be applicable at a wide scale since enzymes have a short half-life so engineered organisms may not remain catalytically active for long enough to be effective. On the other hand, to fix unpredictable enzyme-polymer interactions, there has been development of new techniques such as computational tools to visualize the 3-D interactions between plastics and enzymes. Thus, engineered microbes can remain as a hopeful solution for plastic remediation.
Toxicity of degradation products
A study was performed to understand the toxicity of the degradation of polythene bags and cups by P. aeruginosa, Streptomyces sp., Aspergillus niger, Staphylococcus aureus, and Rhizopus sp. The study found carbon dioxide gas to be the main byproduct of the degradation process of polythene by the bacteria mentioned before. However, the particles produced as a byproduct of PE bio-degradation had negative impacts on the production of polysaccharides, proteins, and nutrient uptake in roots of plants. Another study performed by Aswale focused on how biodegraded polythene affected seed germination in plants. It found that biodegraded polythene was correlated with a decrease in percentage of seed germination, indicating that the byproducts of the breakdown could have negative effects on the seed health.
Food web biomagnification
As seen in Figure 4, food web biomagnification refers to the process by which concentrations of contaminants increase as the trophic levels increase. In terms of plastic, this means when plankton eat plastic, then fish eat the plankton, and larger fish eat that fish, the amount of plastic accumulates in the largest fish. Therefore, removing plastic from the system at the bacteria level would prevent the plastic from bioaccumulating in larger fish. However, as mentioned above, these bacteria are not very efficient at degrading plastic, and therefore do not have the capabilities to create a substantial impact on this problem.
See also
Plastisphere
References
Ocean pollution
Plastivores | Plastic degradation by marine bacteria | [
"Chemistry",
"Biology",
"Environmental_science"
] | 2,927 | [
"Organisms by adaptation",
"Ocean pollution",
"Plastivores",
"Water pollution"
] |
70,433,574 | https://en.wikipedia.org/wiki/Phacopsis%20australis | Phacopsis australis is a species of lichenicolous (lichen-dwelling) fungus in the family Parmeliaceae. It is found in a few locations in South Africa, where it grows on the thalli of several species of the leafy lichen genus Xanthoparmelia. Unlike other members of genus Phacopsis, the fungus does not induce the formation of galls in its host.
Taxonomy
The fungus was formally described as a new species in 2002 by lichenologists André Aptroot and Dagmar Triebel. The type specimen was collected from a farm in the Droekloof Mountains (Willowmore, Cape Province) at an altitude of . Here it was found growing on Paraparmelia molybdiza, a foliose (leafy) and saxicolous (rock-dwelling) lichen that is now known as Xanthoparmelia molybdiza.
Description
Phacopsis australis grows superficially (i.e., on the surface) on the thallus of its host. Unlike other members of the genus Phacopsis, it is cecidogenous, meaning it does not cause the formation of galls in the host. Its apothecia are dark brown to black, range from sessile to slightly immersed in the thallus, and measure 0.2–0.4 mm in diameter. The hypothecium (the tissue in the apothecium immediately below the subhymenium) is hyaline (colourless) to pale brown, measuring about 20–60 μm thick. The ascospores are ellipsoid to fusiform (spindle-shaped) and contain oil droplets; they typically measure 12–15 by 5.5–7 μm with a 0.5 μm-thick spore wall.
Known hosts for Phacopsis australis are all from the genus Xanthoparmelia: X. annexa, X. molybdiza, X. conspersa and X. incerta.
Lecanora lasalliae is quite similar in appearance to Phacopsis australis, but this lookalike lacks algae in its excipulum (the rim of tissue around the apothecia), and has larger ascospores.
Distribution
Phacopsis australis is only known from a few collections, in Cape Province and in the Drakensberg region of KwaZulu-Natal. Although one of its hosts, X. conspersa, has a cosmopolitan distribution with many specimens having been studied, the fungus has not been recorded occurring out of South Africa.
References
Parmeliaceae
Fungi described in 2002
Lichenicolous fungi
Taxa named by André Aptroot
Fungi of Africa
Taxa named by Dagmar Triebel
Fungus species | Phacopsis australis | [
"Biology"
] | 586 | [
"Fungi",
"Fungus species"
] |
70,435,983 | https://en.wikipedia.org/wiki/LY3372689 | Ceperognastat (LY3372689) is a drug candidate molecule under investigation to treat Alzheimer's disease. It targets the enzyme O-GlcNAcase. Its result is to reduce formation of tau protein tangles.
A molecule containing radioactive fluorine was used with a PET scan to show that ceperognastat binds in the human brain.
Ceperognastat was discovered via a high-throughput screening campaign followed by further optimization.
Eli Lilly and Company is recruiting subjects for a clinical trial. Some hospitals in Australia: St Vincent's Hospital, Sydney
Hornsby Ku-Ring-Gai Hospital, The Prince Charles Hospital, The Queen Elizabeth Hospital, Adelaide, Box Hill Hospital, and Delmont Private Hospital are involved. Results of the trial were expected by June 2024. Primary completion of the study occurred on 9th July 2024, with full completion expected in August 2024. In an investor call, it was disclosed that ceperognastat missed the primary endpoint of improvement on the Integrated Alzheimer's Disease Rating Scale. The detailed results of this study are expected to be disclosed at a conference in late 2024.
Chemical
The molecule contains three rings: thiazole, piperidine and oxadiazole. Other functional groups included are an ether, acetamide, and a fluoride.
References
Oxadiazoles
Thiazoles
Piperidines
Acetamides
Ethers
Organofluorides | LY3372689 | [
"Chemistry"
] | 301 | [
"Organic compounds",
"Functional groups",
"Ethers"
] |
70,436,716 | https://en.wikipedia.org/wiki/Citrate%E2%80%93malate%20shuttle | The citrate-malate shuttle is a series of chemical reactions, commonly referred to as a biochemical cycle or system, that transports acetyl-CoA in the mitochondrial matrix across the inner and outer mitochondrial membranes for fatty acid synthesis. Mitochondria are enclosed in a double membrane. As the inner mitochondrial membrane is impermeable to acetyl-CoA, the shuttle system is essential to fatty acid synthesis in the cytosol. It plays an important role in the generation of lipids in the liver (hepatic lipogenesis).
The name of the citrate-malate shuttle is derived from the two intermediates – short-lived chemicals that are generated in a reaction step and consumed entirely in the next – citrate and malate that carry the acetyl-CoA molecule across the mitochondrial double membrane.
The citrate–malate shuttle is present in humans and other higher eukaryotic organisms and is closely related to the Krebs cycle. The system is responsible for the transportation of malate into the mitochondrial matrix to serve as an intermediate in the Krebs cycle and the transportation of citrate into the cytosol for secretion in Aspergillus niger, a fungus used in the commercial production of citric acid.
Mechanism
Structure of mitochondria
All cells need energy to survive. Mitochondria is a double-membrane structure in the body cell that generates and transports essential metabolic products. The three layers of this structure are the outer membrane, intermembrane space, and inner membrane. The space inside the mitochondria is called the mitochondrial matrix, while the region outside is the cytosol. The outer membrane allows most small molecules to pass through. In contrast, the inner membrane transports specific molecules only, which is impermeable to many substances. Therefore, a shuttle is required for the transportation of molecules across the inner membrane. It acts as a pump to drive the substances from the inner membrane to the outside.
Component of system
On the surface of cells, there are many proteins. Some proteins are involved in recognition, attachment, or transportation. The citrate-malate shuttle system consists of citrate shuttle and malate shuttle, which are carrier proteins. Carrier proteins are present on the cell surface. They transport different molecules across the mitochondria. In this system, the substances being transported are malate and citrate.
The starting material is acetyl-CoA. It is a molecule that is involved in ATP synthesis, protein metabolism, and lipid metabolism. As the inner membrane is not permeable to this molecule, acetyl-CoA needs to be converted into other products for effective transport. It is also the first step of the reaction.
Movement of citrate and malate
The process occurs in two cellular locations: the cytosol and the mitochondria matrix. A cycle is formed by the system, ensuring that the conversion between acetylene, oxaloacetate, citrate, and malate can continue without the need for foreign molecule addition.
It involves six major steps:
Step 1
An acetyl group of acetyl-CoA combines with oxaloacetate to form citrate, releasing the coenzyme group (CoA) in the mitochondrial matrix.
Step 2
The citrate binds to citrate transporters.
The shuttle delivers the citrate from the inner membrane to the intermembrane space.
There is a net movement of the citrate from the intermembrane space to the cytosol across the outer membrane, following the concentration gradient.
Step 3
Using ATP as energy, citrate is broken down into the acetyl group and oxaloacetate.
The acetyl group joins the coenzyme in the cytosol, forming acetyl-CoA.
Step 4
Oxaloacetate is reduced by NADH to malate in the cytosol, releasing free electrons.
Step 5
The malate is transported by the malate shuttle, moving from the cytosol to the matrix.
Step 6
The malate is oxidized by NAD+ (the oxidizing agent) to oxaloacetate again, releasing NADH. The replenishment of oxaloacetate can be achieved. The oxaloacetate can react with the acetyl-CoA in the first step, completing a cycle.
Function
The citrate-malate shuttle allows the cell to produce fatty acid with excess acetyl-CoA for storage. The principle is similar to that of insulin, which turns excess glucose in the body into glycogen for storage in the liver cells and skeletal muscles, so that when there is a lack of energy intake, the body could still provide itself with glucose by breaking down glycogen. The citrate-malate shuttle enables more compact storage of chemical energy in the body in the form of fatty acid by transporting acetyl-CoA into the cytosol for fatty acid and cholesterol synthesis. The lipids produced can then be stored so that they can be used in the future.
Acetyl-CoA is generated in the mitochondrial matrix from two sources: pyruvate decarboxylation in glycolysis and the breakdown of fatty acids through β-oxidation, which are both essential pathways of energy production in humans. Pyruvate decarboxylation is the step that connects glycolysis and the Krebs cycle and is regulated by the pyruvate dehydrogenase complex when blood glucose levels are high. Otherwise, fatty acid β-oxidation occurs, and acetyl-CoA is required to generate ATP through the Krebs cycle. In a subject with defective citrate-malate shuttle, acetyl-CoA in mitochondria cannot exit into the cytosol. Fatty acid synthesis is hence hindered, and the body would not be able to store excess energy as efficiently as a normal subject.
In addition, improper functioning of the citrate-malate shuttle can result in disruption of the Krebs cycle.
Linkage to Krebs cycle
The Krebs cycle, also known as the TCA cycle or Citric Acid cycle, is a biochemical pathway that facilitates the breakdown of glucose in a cell. Both citrate and malate involved in the citrate-malate shuttle are necessary intermediates of the Krebs cycle. Usually, oxaloacetate in the Krebs cycle is generated from the carboxylation of pyruvate in the mitochondrion; however, malate generated in the cytosol can also enter the mitochondrion through the transport protein located in the inner mitochondrial membrane to directly join the Krebs cycle.
The mitochondrial transport proteins are encoded by the SLC25 gene in humans and facilitate the transportation of various metabolites, including citrate and malate, in the Krebs cycle. These transport proteins control the flow of metabolites in and out of the inner mitochondrial membrane, which is impermeable to most molecules. They connect the carbohydrate metabolism of the Krebs cycle to fatty acid synthesis in lipogenesis by catalyzing the transportation of acetyl-CoA out of the mitochondrial matrix into the cytosol, which is done in the form of citrate export from the mitochondria to the cytosol. Cytosolic citrate, meaning citrate in the cytosol, is a key substrate for the generation of energy. It releases acetyl-CoA and provides NADPH for fatty acid synthesis, and, in subsequent pathways, generates NAD+ for glycolysis. Citrate also activates acetyl-CoA carboxylase, an enzyme that is essential in the fatty acid synthesis pathway.
Citrate-malate shuttle might partly or completely replace the function of the Krebs cycle in cancer cell metabolism.
Association with cancer
Alternate metabolic pathway in cancer cell
Recent study proposed that the citrate–malate shuttle may contribute to sustaining cancer cells through a β-oxidation-citrate–malate shuttle metabolic pathway. In normal cells, β-oxidation produces acetyl-CoA which enters the Krebs cycle to produce ATP, and β-oxidation cannot continue if the Krebs cycle is impaired and acetyl-CoA accumulates. However, cancer cells may carry out continuous β-oxidation by connecting it to the citrate–malate shuttle. The new metabolic pathway consists of mitochondrial transport proteins and several enzymes, including ATP-citrate lyase (ACLY) and malate dehydrogenases 1 and 2 (MDH1 and MDH2). The proposed metabolic pathway may explain the Warburg effect – that cancer cells produce energy through a suboptimal pathway – and hypoxia in cancer.
The energy efficiency of this pathway is 3.76 times less than the normal β-oxidation Krebs cycle pathway, only producing 26 moles instead of 98 moles of ATP from 1 mole of palmitate.
It is still unsure whether this pathway exists in cancer cells. Factors preventing this pathway from occurring includes lipotoxicity of palmitate and stearate.
Liver cancer
Role of liver
The liver contains metabolic active tissues as it is responsible for detoxification, protein and carbohydrate metabolism. Therefore, It needs a lot of energy to function and contains abundant mitochondria. Any abnormalities in mitochondria would affect liver metabolism. If the liver does not work properly, it may produce excess metabolites, leading to accumulation; in contrast, it may also fail to produce certain chemicals. As a result, the imbalance of metabolites may lead to liver cancer development, i.e. hepatocarcinogenesis.
Cancer cells
The growth and development of normal cells follow a cycle in a controlled and ordered manner. When they are damaged, they will die through a process called apoptosis. However, apoptosis is disrupted in cancer cells, allowing them to divide and grow uncontrollably, potentially invading other tissues or organs. They will not undergo the normal death process of body cells.
Hepatocellular carcinoma (HCC) is a prevalent type of liver cancer that accounts for over 80% of cases. It is lethal cancer due to the remarkable drug tolerance, spread potential and high chance of relapse. Scientists have carried out many kinds of research in finding out the risk factors of HCC progression.
Risk factors
Metabolic disorder is one of the causes of liver cancer. Mitochondria is responsible for oxidation using NAD+, which is produced in Step 4 of the citrate–malate shuttle system. In high obesity or insulin resistance (diabetes) patients, their body contains large amounts of fatty acid, the shuttle system might not generate sufficient NAD+ to metabolize the fat efficiently. They also exhibit a low NAD+ level. Thus, it is more likely for obesity or diabetes patients to develop liver cancer.
Moreover, overloading of mitochondria may occur. There is an increase in reactive oxygen species level in the liver. Those species are highly reactive and would attack liver cells. They can damage the DNA strands. Cells with DNA damage may divide abnormally. They might grow into cancer cells, resulting in HCC.
Another risk factor is mutations and overexpressed citrate–malate shuttle. A high frequency mutated gene in a wide range of cancers, Ras oncogene, has a significantly close association to HCC. Many HCC patients carry this gene. They also have abnormal citrate–malate shuttle. The research of Dalian Medical University shows that there is a noticeable increase in the HCC patients’ citrate and malate levels, suggesting the possibility of higher activity of citrate–malate shuttle. This mechanism is effective when TCA cycle activity is low. The shuttle also helps the production of fatty acid and lactic acid.
In liver cancer cells, the TCA cycle is blocked, causing accumulation of excess pyruvate. It is a signal of the body defense mechanism. Normally, the cancer cells would die under a high pyruvate level. However, the overexpressed citrate–malate shuttle can remove the excessive pyruvate. In this situation, the natural cell death of liver tumor will not occur. The cancer cells can keep growing.
In addition, high shuttle activity is linked to increase in fatty acid generation. It is also a risk factor of HCC.
Genetics and evolution
Mitochondrial diseases
Mitochondrial diseases are usually caused by mutation in mitochondrial DNA. These genes regulate different proteins synthesis, including carrier proteins and certain enzymes.
The replication of mitochondrial DNA follows binary fission. In this process, 1 set of genes would divide into 2 sets. The mitochondrial gene of children is inherited from their mother only. If there are any genetic defects or mutations in the mother’s mitochondrial DNA, it would be inherited by the children. If those changes in genes can cause mitochondrial diseases, the children have a 100% possibility of acquiring the diseases.
For the malate-oxaloacetate shuttle, 4 major genes are involved. They are PMDH1, MDH, PMDH2, mMDH1. PMDH-1 and PMDH-2 encode two different enzymes that provide NAD+ for the oxidation of malate. In addition, MDH and mMDH1 encode for an enzyme that directly oxidizes malate.
Importance
SLC25 is a gene that is essential for the synthesis of a wide range of mitochondrial transporters, such as citrate shuttle. Mutations in this gene can result in dysfunctional mitochondria. This leads to significant decrease in the energy production of our body cells, causing severe metabolic diseases. It can cause severe symptoms in organs or tissues that have high energy demand. These organs include the liver, brain, heart, kidneys. They require abundant functional mitochondria to function. Mitochondrial disorders caused by defective or reduced SLC25 gene expression can cause diseases, such as CAC deficiency, HHH syndrome, AGC2 deficiency (CTLN2/NICCD), , Congenital Amish microcephaly, Early epileptic encephalopathy, AAC1 deficiency, PiC (isoform A) deficiency, AGC1 deficiency, Neuropathy with striatal necrosis, and Congenital sideroblastic anaemia.
In addition, SLC25 gene is crucial for the survival of organisms because of its high frequency in the genomics of different organisms. It indicates that this gene is favourable for the survival of a species in response to the environmental features, so it is preserved and passed along the generation. In other words, the gene is positively selected for evolution. Not only is SLC25 gene found in humans, but also in other animals, or even microorganisms like bacteria and viruses. It shows that this gene is conserved among different species. This might provide evidence for the significance and essentiality of the gene in the survival of organisms.
References
Biochemical reactions
Citric acid cycle
Metabolism
de:Citrat-Shuttle | Citrate–malate shuttle | [
"Chemistry",
"Biology"
] | 3,122 | [
"Carbohydrate metabolism",
"Biochemical reactions",
"Cellular processes",
"Biochemistry",
"Metabolism",
"Citric acid cycle"
] |
70,437,163 | https://en.wikipedia.org/wiki/Wicklowia%20aquatica | Wicklowia aquatica is a freshwater fungus species in the genus Wicklowia that is found in Florida and Costa Rica. Wicklowia aquatica produces the depsidone compound folipastatin.
References
Pleosporales
Fungi described in 2010
Fungi of Florida
Fungi of Central America
Fungi without expected TNC conservation status
Fungus species | Wicklowia aquatica | [
"Biology"
] | 74 | [
"Fungi",
"Fungus species"
] |
70,440,763 | https://en.wikipedia.org/wiki/Phacopsis%20lethariellae | Phacopsis lethariellae is a species of lichenicolous (lichen-dwelling) fungus in the family Parmeliaceae. It was formally described as a new species in 1995 by Josef Hafellner and Gerhard Rambold. The type specimen was collected by the first author from La Fortaleza (La Gomera) at an altitude of , where it was found growing on the thallus of the lichen Lethariella intricata. It causes formations of galls, which also creates a torsion on the thallus. It has dark brown to black apothecia that are typically 0.3–0.5 mm in diameter, with a convex disc. Its ascospores are ellipsoid to ovoid, measuring 11–13 by 6–7 μm. The fungus, known to occur only in the Canary Islands, is named after the genus of its host.
References
Parmeliaceae
Fungi described in 1995
Fungi of the Canary Islands
Taxa named by Josef Hafellner
Fungus species
Taxa named by Gerhard Rambold | Phacopsis lethariellae | [
"Biology"
] | 218 | [
"Fungi",
"Fungus species"
] |
70,440,972 | https://en.wikipedia.org/wiki/Large%20Integrated%20Flexible%20Environment | The Large Integrated Flexible Environment (LIFE) is an inflatable space habitat design currently being developed by Sierra Space. The proposed Orbital Reef commercial space station would include multiple LIFE habitats.
Development
In September 2022 Sierra Space completed a successful sub-scale Ultimate Burst Pressure test of a LIFE prototype. A second successful test was completed later that year, exceeding NASA certification requirements. On 22 January 2024 the company announced a successful full scale burst test, exceeding safety margins by 27%.
Pathfinder
As soon as the end of 2026, before using LIFE as part of Orbital Reef, Sierra Space is proposing to launch a “pathfinder” version of LIFE as a standalone space station.
See also
List of space stations
References
Space stations | Large Integrated Flexible Environment | [
"Astronomy"
] | 146 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
70,441,044 | https://en.wikipedia.org/wiki/Macro-creatine%20kinase | Macro-creatine kinase (macro-CK) is a macroenzyme, an enzyme of high molecular weight and prolonged half-life found in human serum. It is one of the most common macroenzymes. Macro-CK type 1 is a complex formed by one of the creatine kinase isoenzyme types, typically CK-BB, and antibodies; typically IgG, sometimes IgA, rarely IgM. Macro-CK type 2 is formed from mitochondrial CK polymer.
Macro-CK type 1 has been associated with autoimmune and other chronic conditions. Macro-CK type 2 has been associated with malignancy.
Macro-CK has been implicated as a source of interference in interpretation of medical labs.
References
Blood tests
Chemical pathology | Macro-creatine kinase | [
"Chemistry",
"Biology"
] | 156 | [
"Biochemistry",
"Blood tests",
"Chemical pathology"
] |
73,294,620 | https://en.wikipedia.org/wiki/Indium%20perchlorate | Indium perchlorate is the inorganic compound with the chemical formula . The compound is an indium salt of perchloric acid.
Synthesis
Dissolving indium hydroxide in perchloric acid:
Physical properties
Indium(III) perchlorate forms colorless crystals. It is soluble in water and ethanol.
The compound forms a hydrate , that melts in its own crystallization water at 80 °C.
The octahydrate is easily soluble in ethanol and acetic acid.
References
Perchlorates
Oxidizing agents
Indium compounds | Indium perchlorate | [
"Chemistry"
] | 112 | [
"Perchlorates",
"Redox",
"Oxidizing agents",
"Salts"
] |
73,295,978 | https://en.wikipedia.org/wiki/Burnt%20Village | Burnt village is an oil-on-canvas painting by Finnish painter Albert Edelfelt completed in 1879.
The painting depicts an imaginary scene from the time of the Cudgel War of 1596–1597, a peasant uprising in Finland, which was then part of the Kingdom of Sweden. In the painting, a Finnish peasant family has fled their home village, which has been burnt down by a military force. The creator Albert Edelfelt donated the painting to Cygnaeus Gallery in Helsinki, Finland, where it is on display.
Edelfelt made a study in oils for the painting in 1878–79.
Study
References
1879 paintings
Paintings by Albert Edelfelt
Paintings in the Ateneum
Paintings of people
Oil on canvas paintings
Destruction of buildings
War paintings | Burnt Village | [
"Engineering"
] | 154 | [
"Destruction of buildings",
"Architecture"
] |
73,298,723 | https://en.wikipedia.org/wiki/Red%20Sea%20brine%20pool%20microbiology | The Red Sea and its extensions of the Gulf of Suez and the Gulf of Aqaba contain the largest recorded concentration of deep-sea brine pools on the planet. These pools have many features that make them uninhabitable to almost all organisms on the planet, yet certain communities of microbes thrive within these extreme environments that have temperatures ranging from 2.0 °C to 75 °C. The Red Sea brine pools have extreme salt concentrations and varying compositions of nutrients and other chemicals that directly affect their microbiomes. There are approximately 25 individual pools in the region, some of which are closely clustered together in groups, leading to their undetermined classification of names. The brine pools originate from hydrothermal vents, the shifting of tectonic plates, and the accumulation of water with properties that make it unsuitable for mixing, leading to its accumulation within faults and divots in the sea floor. Atlantis II Deep, Discovery Deep, and the Kebrit are the most investigated and researched brine pools within the Red Sea. Additionally, many microbial species form beneficial symbiotic relationships with organisms living and feeding in proximity to the pools. These relationships allow for the study of specialized adaptations of microbes to brine pool environments.
List
In addition to the originally-discovered warm brine pools, recent discoveries have found four smaller warm brine pools named the NEOM Brine Pools located in the Gulf of Aqaba. Furthermore, multiple cold seeps have been identified in the Red Sea (the Thuwal Cold Seeps), consisting of two individual pools. Three of these Red Sea brine pools are unnamed, as they are small and potentially extensions of other nearby larger pools.
Viral diversity
Composition
The virus community within the many Red Sea brine pools is largely unexplored. However, with the use of metagenomics, viral communities of the Atlantis II Deep, Discovery Deep, and the Kebrit Deep reveal diverse and distinct viruses within and between the brine pools. Across all three brine pools, double-stranded DNA (dsDNA) are the most dominant viruses. Of the dsDNA viruses investigated, Caudovirales are the most abundant across all three brine pools. Low abundances of Phycodnaviridae and trace amounts of Iridoviridae are also present within the brine-seawater interfaces, and thus may be indicative of a "pickling" effect rather than a host-specific presence.
Stratification of viral communities
Viral species tend to follow their bacterial-host population dynamics. Bacterial and archaeal composition and abundance differ between specific layers of the brine pool, including the overlying brine seawater, the brine-water interface, the brine-pool sediments, and direct brine waters. As a result, the viral community within the brine pools of the Red Sea are stratified across the brine-seawater interface. The Kebrit Deep's brine-seawater interface upper layer is dominated by marine bacteria-infecting viruses, relative to the lower layer brine-seawater interface which is dominated by haloviruses and halophages.
Role of viruses
Deep-sea marine viruses maintain the diversity and abundance of the microbial community, recycling and supplying essential nutrients and biomolecules, and regulating the biogeochemical cycling. In deep, anoxic environments such as the Red Sea brine pools, viral infection of prokaryotes releases cellular DNA. Extracellular DNA released through infection supplies highly labile biomolecules in these water conditions limited by external input supporting microbial communities. Through lysogenic viral infection and horizontal gene transfer, the viral community in the Red Sea brine pools contribute to microbial DNA repair, nucleotide metabolism, and the evolutionary adaptations of the microbial community.
Bacterial and archaeal diversity and adaptations
The Red Sea brine pools were once thought to be inhospitable to life. However, extremophiles have adapted to these environments through the development of novel enzymes and metabolic pathways.
The various brine pools contain somewhat similar diversities of microbes; however, due to the different characteristics of each brine pool, distinct microbe compositions are seen. Similarly to the Gulf of Mexico brine pools, the Red Sea brine pool experiences stratification within each distinct brine pool. Therefore, as a result of the stratification, varying physical and chemical properties occur with respect to depth, ensuing a transition in the microbial community with respect to depth.
Moreover, the stratification causes sharp brine-seawater interfaces, with typically-steep gradients in salinity, temperature, density, oxygen, and pH. These distinct interfaces between layers of well-mixed water are characteristic of liquids that are stabilized by salt but destabilized by heating from below. Heat at the bottom of these stable salinity gradients causes double-diffusive convection events.
Specific bacterial composition
Deep-sea anoxic brines (referred to as DHABs, deep hypersaline anoxic basins) are developed by a process of re-dissolving of evaporitic sediments buried at shallow depths, tectonic ejection of the interstitial brine reacted with the evaporites, or by hydrothermal phase separation.
These are examples of various types of bacteria (Table 1) under the brine pools:
Influence of stratification
Stratification within and around water layers is a characteristic of brine pools due to the highly saline environment. Specifically, in the Red Sea, as a result of this stratification in the deep sea brine pools, microbial communities are subject to differences their vertical distribution and composition. For example, through the use of metagenomics and pyrosequencing, the microbial communities of two deeps (Atlantis II and Discovery) were investigated with respect to vertical distribution. In terms of archaeal communities, both deeps showed similar composition having the upper layer (20–50 m) enriched in Halobacteriales, and as salt concentration increased and oxygen decreased, Desulfurococcales tended to dominate due to physiological adaptations. The bacterial composition in the upper layer consisted of Cyanobacteria due to the presence of light. Deeper in the water column, Proteobacteria, specifically the gamma-subdivision group (orders Thiotrichales, Salinisphaerales, Chromatiales, and Alteromonadales) were found to dominate the more extreme conditions.
The stratification within the Red Sea Brine Pools therefore allows for a complex composition of the microbial community with depth. Due to the variability between each brine pool, this would account for differences in taxa at each location and at each depth.
Bacterial enzymes
Extremozymes are very prominent in Red Sea brine pools as they have the ability to be able to catalyze reactions under harsh environments.
In general, extremozymes can be separated into categories depending on habitats, such as those that can resist extremes of cold (psychrophiles), heat (thermophiles and hyperthermophiles), acidity (acidophiles), alkalinity (alkaliphiles), and salinity (halophiles). Red Sea brine pools are subject to host a polyextremophilic microbiological community providing the environment with a source of extremozymes.
Moreover, most of the extremozymes are classified into three classes of enzymes: oxidoreductases, transferases, and hydrolases; these are important in terms of metabolic processes for the organisms within this habitat as well as for potential applications.
Symbiotic Relationships
Several anoxic, high-salinity deep-sea basins in the Red Sea generate notably sharp interfaces that produce a variety of physicochemical gradients. By acting as a particle trap for organic and inorganic elements from saltwater, brine pools have the ability to significantly increase the supply of nutrients and the possibility for bacterial growth. On the other hand, halophilic bacteria are required to evolve specific structures to survive the brine pool habitat. For example, halophilic enzymes have a higher proportion of acidic amino acid residues than non-halophilic homologues. These bacterias accumate high concentrations of KCl in their cytoplasms, which reach saturation.
Potential applications for enzymes
Recently, twelve enzymes have been detected in the Red Sea brine pools (Atlantis II Deep, Discovery Deep, and Kebrit Deep) with specific biochemical properties that are promising in their potential applications. The microbes that inhabit the hot, hypersaline, anoxic, and toxic-metal-contaminated Red Sea brine pools produce or accumulate microbial enzymes known as extremozymes allowing life to survive. The chemical and physical properties, in addition to the stability of the extremozymes, provides potential uses in areas including industrial, biotechnical, and pharmaceutical disciplines.
The different enzymes can be attributed to the different organisms that live within each brine pool due to the environments' variable conditions. The Kebrit Deep, one of the smallest Red Sea brine pools, is at 21-23 °C not considered a hot brine. Other characteristics include a pH of 5.2, an 84-m-thick brine layer, and high levels of hydrogen sulfide. The Atlantis II Deep is among the largest Red Sea brine pools and has high temperatures (~68 °C), a pH of 5.3, and high metal content. While Discovery Deep is similar to Atlantis II Deep, it has differences in metal content and is less extreme overall.
Recent discoveries and future implications
The Thuwal cold seeps were accidentally discovered in the Red Sea at about 850m deep on 7 May 2010 by a remotely-operated vehicle. The scientists were conducting a continental slope survey of the Red Sea as part of the KAUST Red Sea Expedition 2010. These cold seeps occur along the tectonically-active continental margin within the Red Sea where hypersaline brine seeps out of the seabed and associates with brine pool formations. The Thuwal cold seeps are considered "cold" due to their cooler temperature (about 21.7 °C) relative to other brine pools found within the Red Sea.
Cold seeps are a component of deep sea ecosystems where chemosynthetic bacteria acting as the base of this community use the methane and hydrogen sulfide in seep water as their energy source. The microbial community acts as a base of the food chain for an ecosystem of organisms that helps sustain and feed bottom- and filter-feeders such as bivalves.
Discovery of NEOM Brine Pools
During a 2020 research expedition, with the use of bathymetry and geophysical observations, four complex brine pools were discovered in the northern Gulf of Aqaba, which had not yet been known to harbor brine pools. The discovery consisted of three small brine pools less than 10 m2 and another pool that was 10,000 m2 which were given the name NEOM Brine Pools. The NEOM Brine Pools are distinct from other Red Sea brine pools as they are located much closer to the shore. Due to the brine pools' location at 2 km offshore, they are subject to sediment shed and as a result can preserve geophysical properties that could potentially give insight to historical tsunamis, flash floods, and earthquakes that may have occurred in the Gulf Aqaba.
Within these NEOM brine pools, stratification of the overlaying water, the interface, and the brine water caused stratification of microbial diversity. The upper layer consisted of aerobic microbes such as Gammaproteobacteria, Thaumarchaeota Alphaproteobacteria, and Nitrospira. In the deeper convective layers of the NEOM pools, sulfate-reducing and methanogenic microorganisms were more abundant, given the anaerobic conditions.
References
Microorganisms
Biological oceanography
Marine biology
Marine microorganisms
Wikipedia Student Program | Red Sea brine pool microbiology | [
"Biology"
] | 2,492 | [
"Marine microorganisms",
"Microorganisms",
"Marine biology"
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73,299,039 | https://en.wikipedia.org/wiki/Grammonus%20opisthodon | Grammonus opisthodon, the bighead brotula, is a species of fish known from South Africa.
Description
This fish has an eel-like body with a rounded head. It is dark brown in colour with small brown spots on the head. The dorsal, anal and caudal fins are translucent and continuous with many fine rays. They have no spiny rays. The largest known specimen was long.
Distribution and habitat
This fish is known from two nearby sites off the coast of the Eastern Cape of South Africa. It has been found at a depth of at Port Alfred and the Storms River Mouth.
Conservation
Only two specimens have been collected - one prior to 1934 and a second in the early 1980s.This species is currently listed as data deficient by the IUCN as very little is known about it.
References
Fish described in 1934
Fish of South Africa
Data deficient species | Grammonus opisthodon | [
"Biology"
] | 178 | [
"Biota by conservation status",
"Data deficient species"
] |
73,302,567 | https://en.wikipedia.org/wiki/Design%20Guild | The Design Guild, also known as the Auckland Design Guild, formed in Auckland in June 1949 for the promotion of good design, was a short-lived professional body for designers in New Zealand.
Background
The Guild emerged just over a year after the publication of New Zealand Design Review in Wellington in April 1948, and soon after the New Zealand lecture tour of industrial designer and president of the Society of Industrial Artists (SIA) in Britain, Milner Gray, in April 1949, arranged by the British Council in Australia and New Zealand.
Gray's lecture, The Industrial Design Profession in Great Britain, touched on the design organisations there. Amongst these, the most complete effort to organise the profession had been that of the Society of Industrial Artists formed in 1930, "to establish for designers a status comparable with that of the architect and the engineer." And on that path, "in 1936 the Royal Society of Arts singled out a limited number of designers of high eminence and bestowed on them a diploma carrying the right to use the affix R.D.I. (Royal Designer for Industry). This is often called 'the blue ribbon' of the profession…"
Several New Zealanders in Britain had attained Royal Designer for Industry status—Keith Murray amongst the first in 1936 and Brian O'Rorke in 1939.
At the Guild's inaugural luncheon in Auckland in June 1949, Cyril Knight, Dean of the Faculty of Architecture at Auckland University College, affirmed that: "The Guild is an organisation formed to bring together designers in various fields and to publicise good design." He reminded some 200 present members that: "This country is full of shoddy goods, shoddy houses, shoddy cities and the implements we use, the very tools of trade, are shoddy too," created on the excuse that they will "do the job". In pursuit of "gracious living", he concluded: "Thus it may be said that in activities large and small there is room for good design and reason too, for a forum to talk about it, to demonstrate and explain how the pattern of life based upon good design can offer great happiness to mankind."
The Free Lance, 27 July 1949, also observed that:
… numbers of returned servicemen members who, having seen something of fine architecture and design during overseas service, now feel the lack of these things in their own country. They are keen to support any movement which will help the Dominion to demand and attain a higher standard.
The work of a number of members was presented in a private four-day "get-together" exhibition for designers of all types, on the first floor of Edson's Building, 270 Queen Street, in August. The chairman, architect Alan Rigby, explained: "As New Zealanders we can make many things that suit New Zealand better than things made in London or New York", and "Getting together like this helps us find the common approach we need." Then, responding to public demand, the Guild opened it to the public. Rigby responded: "We were amazed. People kept calling us up asking if they could bring a dozen guests along." Amongst the exhibitors, Gifford Jackson, a design draughtsman at Fisher & Paykel, had designed washing machine components, brand logos and commercial refrigeration equipment, as well as appliance store and milk bar layouts before joining D. J. Davis Ltd to design photographic equipment. Jackson's freelance projects included an anchor and toys. Typography was represented by Robert Lowry and Ronald Holloway. Clifton Firth combined commercial art and photography. Monthly meetings at the Guild's two-storied suite of rooms, lectures, public exhibitions and articles in a proposed co-sponsored Design Review magazine were to follow.
The Design Guild, however, didn't last the year. Peter Parsons later commented: "With the best intentions in the world the movement was too theoretical. For instance considerable time was devoted to ruling out any commercial aspect to an exhibition of members' work. Four members resigned and formed a partnership of designers and Jackson left New Zealand to become quite a successful industrial designer on his own account in New York." If there was another lesson, it left some participants aware of the effect of meteoric public relations, and subsequent falls.
Design organisations emerged in following years—Visual Arts Association (VAA) in Dunedin in 1952, the Design Association of New Zealand (DANZ) in Christchurch in 1959, and New Zealand Society of Industrial Designers (NZSID) in Auckland in 1959.
Further reading
References
Design institutions
New Zealand design
Learned societies of New Zealand
Organizations established in 1949
Arts organizations established in 1949 | Design Guild | [
"Engineering"
] | 942 | [
"Design",
"Design institutions"
] |
73,305,281 | https://en.wikipedia.org/wiki/Green%20solvent | Green solvents are environmentally friendly chemical solvents that are used as a part of green chemistry. They came to prominence in 2015, when the UN defined a new sustainability-focused development plan based on 17 sustainable development goals, recognizing the need for green chemistry and green solvents for a more sustainable future. Green solvents are developed as more environmentally friendly solvents, derived from the processing of agricultural crops or otherwise sustainable methods as alternatives to petrochemical solvents. Some of the expected characteristics of green solvents include ease of recycling, ease of biodegradation, and low toxicity.
Examples
Water
Although not an organic solvent, water is an attractive solvent because it its non-toxic and renewable. It is a useful solvent in many industrial processes. Traditional organic solvents can sometimes be replaced by aqueous preparations. Water-based coatings have largely replaced standard petroleum-based paints for the construction industry; however, solvent-based anti-corrosion paints remain among the most used today.
Supercritical water (SCW) is obtained at a temperature of 374.2 °C and a pressure of 22.05 MPa. It behaves as a dense gas with a dissolving power equivalent to that of organic solvents of low polarity. However, the solubility of inorganic salts in SCW is radically reduced. SCW is used as a reaction medium, especially in oxidation processes for the destruction of toxic substances such as those found in industrial aqueous effluents. The use of supercritical water has two main technical challenges, namely corrosion and salt deposition.
Supercritical carbon dioxide
Supercritical carbon dioxide (CO2) is the most commonly used supercritical fluid because of its relatively easy to use. Temperatures above 31 °C and pressures above 7.38 MPa are sufficient to obtain supercriticality, at which point it behaves as a good nonpolar solvent.
Alcohols and esters
Ethanol is used in toiletries, cosmetics, some cleaners and coatings. . Bioethanol, made industrially by fermentation of sugars, starch, and cellulose is widely available. Biobutanol (butyl alcohol, various isomers) is also produced by fermentation of sugars. Tetrahydrofurfuryl alcohol (THFA) is a specialty solvent that may be obtained from hemicellulose.
Ethyl lactate, made from lactic acid obtained from corn starch, is notably used as a mixture with other solvents in some paint strippers and cleaners. Ethyl lactate has replaced solvents such as toluene, acetone, and xylene in some applications.
Lipid-derived solvents
Lipids (triglycerides) themselves can be used as solvents, but are mostly hydrolyzed to fatty acids and glycerol (glycerin). Fatty acids can be esterified with an alcohol to give fatty acid esters, e.g., FAMEs (fatty acid methyl esters) if the esterification is performed with methanol. Usually derived from natural gas or petroleum, the methanol used to produce FAMEs can also be obtained by other routes, including gasification of biomass and household hazardous waste. Glycerol from lipid hydrolysis can be used as a solvent in synthetic chemistry, as can some of its derivatives.
Deep eutectic solvents
Deep eutectic solvents (DES) have low melting points, can be cheap, safe and useful in industries. One example is octylammonium bromide/decanoic acid (molar ratio of [1:2]) has a lower density compared to water of 0.8889 g.cm−3, up to 1.4851 g.cm−3 for choline chloride/trifluoroacetamine [1:2]. Their miscibility is also composition-dependent.
A mixture whose melting point is lower than that of the constituents is called an eutectic mixture. Many such mixtures can be used as solvents, especially when the melting-point depression is very large, hence the term deep eutectic solvent (DES). One of the most commonly used substances to obtain DES is the ammonium salt choline chloride. Smith, Abbott, and Ryder report that a mixture of urea (melting point: 133 °C) and choline chloride (melting point: 302 °C) in a 2:1 molar ratio has a melting point of 12 °C.
Natural deep eutectic solvents (NADES) are also a research area relevant to green chemistry, being easy to produce from two low-cost and well-known ecotoxicity components, a hydrogen-bond acceptor, and a hydrogen-bond donor.
Terpenes
Solvents in a diverse class of natural substances called terpenes are obtained by extraction from certain parts of plants. All terpenes are structurally presented as multiples of isoprene with the gross formula (C5H8)n.
D-limonene, a monoterpene, is one of the best known solvents in this class, as is turpentine.
D-limonene is extracted from citrus peels while turpentine is obtained from pine trees (sap, stump) and as a by-product of the Kraft paper-making process (Sell, 2006).
Turpentine is a mixture of terpenes whose composition varies according to its origin and production method. In Canada and the United States, a range of mass concentrations of 40 to 65% α-pinene, 20 to 35% β-pinene, and 2 to 20% d-limonene are found.
α-pinene can replace n-hexane for the extraction of vegetable oil, and as a substitute solvent for extracting molecules such as carotenoids used as food additives.
Turpentine, formerly used as a solvent in organic coatings, is now largely replaced by petroleum hydrocarbons. Nowadays, it is mainly used as a source of its constituents, including α-pinene and β-pinene.
Ionic liquids
Ionic liquids are molten organic salts that are generally fluid at room temperature. Frequently used cationic liquids, include imidazolium, pyridinium, ammonium and phosphonium. Anionic liquids include halides, tetrafluoroborate, hexafluorophosphate, and nitrate. Bubalo et al. (2015) argue that ionic liquids are non-flammable, and chemically, electrochemically and thermally stable. These properties allow for ionic liquids to be used as green solvents, as their low volatility limits VOC emissions compared to conventional solvents. The ecotoxicity and poor degradability of ionic liquids has been recognized in the past because the resources typically used for their production are non-renewable, as is the case for imidazole and halogenated alkanes (derived from petroleum). Ionic liquids produced from renewable and biodegradable materials have recently emerged, but their availability is low because of high production costs.
Switchable solvents
Bubbling CO2 into water or an organic solvent results in changes to certain properties of the liquid such as its polarity, ionic strength, and hydrophilicity. This allows an organic solvent to form a homogeneous mixture with the otherwise immiscible water. This process is reversible, and was developed by Jessop et al. (2012) for potential uses in synthetic chemistry, extraction and separation of various substances. The degree of how green switchable solvents are is measured by the energy and material savings it provides; thus, one of the advantages of switchable solvents is the potential reuse of solvent and water in post-process applications.
Solvents from waste materials
First-generation biorefineries exploit food-based substances such as starch and vegetable oils. For example, corn grain is used to make ethanol. Second-generation biorefineries use residues or wastes generated by various industries as feedstock for the manufacture of their solvents. 2-Methyltetrahydrofuran, derived from lignocellulosic waste, would have the potential to replace tetrahydrofuran, toluene, DCM, and diethyl ether in some applications. Levulinic acid esters from the same source would have the potential to replace DCM in paint cleaners and strippers.
Used cooking oils can be used to produce FAMEs. Glycerol, obtained as a byproduct of the synthesis of these, can in turn be used to produce various solvents such as 2,2-dimethyl-1,3-dioxolane-4-methanol, usable as a solvent in the formulation of inks and cleaners.
Fusel oil, an isomeric mixture of amyl alcohol, is a byproduct of ethanol production from sugars. Green solvents derived from fusel oil such as isoamyl acetate or isoamyl methyl carbonate could be obtained. When these green solvents are used to manufacture nail polishes, VOC emissions report a minimum reduction of 68% compared to the emissions caused by using traditional solvents.
Petrochemical solvents with green characteristics
Due to the high price of new sustainable solvents, in 2017, Clark et al. listed twenty-five solvents that are currently considered acceptable to replace hazardous solvents, even if they are derived from petrochemicals.
These include propylene carbonate and dibasic esters (DBEs). Propylene carbonate and DBEs have been the subject of monographs on solvent substitution. Propylene carbonate and two DBEs are considered green in the manufacturer GlaxoSmithKline's (GSK) Solvent Sustainability Guide, which is used in the pharmaceutical industry. Propylene carbonate can be produced from renewable resources, but DBEs that have appeared on the market in recent years are obtained as by-products of the synthesis of polyamides, derived from petroleum. Other petrochemical solvents are variously referred to as green solvents, such as halogenated hydrocarbons like parachlorobenzotrifluoride, which has been used since the early 1990s in paints to replace smog-forming solvents.
Siloxanes are compounds known in industry in the form of polymers (silicones, R-SiO-R'), for their thermal stability and elastic and non-stick properties. The early 1990s saw the emergence of low molecular weight siloxanes (methylsiloxanes), which can be used as solvents in precision cleaning, replacing stratospheric ozone-depleting solvents.
A final category of petrochemical solvents that qualify as green involves polymeric solvents. The International Union of Pure and Applied Chemistry defines the term "polymer solvent" as "a polymer that acts as a solvent for low-molecular weight compounds". In industrial chemistry, polyethylene glycols (PEGs, H(OCH2CH2)nOH) are one of the most widely used polymeric solvent families. PEGs, with molecular weights below 600 Da, are viscous liquids at room temperature, while heavier PEGs are waxy solids.
Soluble in water and readily biodegradable, liquid PEGs have the advantage of negligible volatility (< 0.01 mmHg or < 1.3 Pa at 20 °C). PEGs are synthesized from ethylene glycol and ethylene oxide, both of which are petrochemical-derived molecules, though ethylene glycol from renewable sources (cellulose) is commercially available.
Physical properties
The physical properties of solvents are important in identifying the solvent used according to the reaction conditions. In particular, their dissolution properties make it possible to assess the use of a particular solvent for a chemical reaction, such as an extraction or a washing. Evaporation is also important to consider, as it can be indicative of the potential volatile organic compound (VOC) emissions.
The following table shows selected properties of green solvents in each category:
Other categories of green solvent have additional properties that preclude their usage in various applications:
Fatty acid methyl esters have been investigated and compared to fossil diesel. At 20 °C or 40 °C, those solvents have a lower density than water at 4 °C (temperature in which the water is the densest):
: from 0.9079 (acetate) to 0.8488 (arachidate);
: from 0.9338 (acetate) to 0.8663 (pentadecanoate).
Their kinematic viscosity depends if they are saturated or unsaturated or even the temperature. At 40 °C, for saturated FAMEs, it goes from 0.340 (acetate) to 6.39 (nonadecanoate), and for unsaturated FAMEs, it goes from 5.61 for the stearate to 7.21 for the erucate.
Their dielectric constant decreases as their alkyl chain gets longer. For example, acetate has a tiny alkyl chain and has a dielectric constant of ε40= 6.852 and ε40= 2.982 for the nonadecanoate.
The properties of switchable solvents are caused by the strength of their conjugate acid's pKa and octanol-water partition coefficient ratio Kow. They must have a pKa above 9.5 to be protonated by carbonated water and also a log(Kow) between 1.2 and 2.5 to be switchable, otherwise they will be hydrophilic or hydrophobic. These properties depend on the volumetric ratio of the compound compared to water. For example, N,N,N-Tributylpentanamidine is a switchable solvent, and for a volumetric ratio of compound to water of 2:1, it has a log(Kow)= 5.99, which is higher than 2.5.
Ionic liquids with low melting points are associated with asymmetric cations, and liquids with high melting point are associated with symmetric cations. Additionally, if they have branched alkyl chains, they will have a higher melting point. They are more dense than water, ranging from 1.05 to 1.64 g·cm−3 at 20 °C and from 1.01 to 1.57 at 90 °C.
Applications
Some green solvents, in addition to being more sustainable, have been found to have more efficient physicochemical properties or reaction yields than when using traditional solvents. However, the results obtained are for the most part observations from experiments on particular green solvents and cannot be generalized. The effectiveness of a green solvent is quantified by calculating the "E factor", which is a ratio of waste materials to desired product produced through a process.
Organic synthesis
Green solvent efficiency has mainly been proven in extractions and separations in comparison to traditional solvents.
Supercritical CO2 is largely used in the food industry as an extraction solvent. Among other processes like flavoring agents, fragrances, essential oils, or lipid extraction from plants, sc-CO2 is a green substitute to dichloromethane in coffee decaffeination, avoiding the use of a hazardous solvent and additional synthesis steps. Sc-CO2 can also apply to polymerization reactions, specifically in PTFE formation to manipulate monomers safely and avoid explosive reactions of peroxide with dioxygen. Although the original process involves water, a green solvent itself, sc-CO2 allows less waste materials.
In deep eutectic solvents, observations report that the higher the solvent's hydrophobicity, the higher the extraction efficiency of neonicotinoids from aqueous solutions, although the exact trend has not been established yet. Additionally, the creation of a biphasic system is easier to achieve. In 2015, several hydrophobic DES composed of highly hydrophobic hydrogen bond donors were reported, one of them being decanoic acid with a quaternary ammonium salt, and a fatty acid as a hydrogen bond acceptor.
The pharmaceutical industry intends to substitute their solvents for greener options, emphasized as solvent use in active substance synthesis is important, which aggrandizes solvents with a high boiling point. Solvent must generally be evaporated at the end of a chemical reaction, hence the insistence on low-boiling solvents in order to minimize the energy required for its removal by distillation.
Industrial chemistry
Ethyl lactate has uses in cleaning metal surfaces, removing greases, oils, adhesives and solid fuels. They are included in aqueous preparations used for industrial degreasing, coatings, adhesives and inks.
Fatty acid methyl esters (FAMEs) have been used as a reactive diluent in coatings for continuous metal strip coating (e.g., the interior coating of food cans), reducing the amount of volatile solvent in this type of coating and lowering its overall toxicity.
Tetrahydrofurfuryl alcohol (THFA) mixtures with other green solvents are studied for their cleaning properties. As an example, the mixture of THFA with FAME and ethyl lactate has been patented as a paint stripper.
Ionic liquids particularly have applications in electrodeposition. Their relevance as green solvents is further enhanced by the emergence of production methods based on renewable and biodegradable resources.
Solvent manufacturers also provide industrial companies with databases to propose green alternative solvent mixtures to those originally used in industrial processes with similar efficiency and reaction yield. However, environmental and safety requirements are not always considered in these suggestions.
Safety
The use of green solvents is increasingly preferred because of their lower environmental impact. These solvents still present dangers for human health as well as for the environment. However, for a number of green solvents, their impact is still unclear, or at least, not categorized yet.
Listed here is selected information from the safety data sheets of common green solvents:
Solvents derived from carbohydrates
For ethanol, the American Conference of Governmental Industrial Hygienists, shortened ACGIH, advises a short-term exposure limit of 1000 ppm to avoid irritating the respiratory tract.
The French National Agency for Food, Environmental, and Occupational Health Safety (ANSES) has recommended a short-term occupational exposure limit value of 100 mg/m3 for butan-1-ol, a solvent used in paints, cleaners, and degreasers, in order to prevent irritation of the mucous membranes of the eyes and upper airways. Since 1998, the ACGIH has suggested an 8-hour exposure limit value (ELV) of 20 ppm of butan-1-ol to prevent irritation of the upper respiratory tract and eyes.
Male rats exposed to THFA develop reproductive toxicity. Moreover, it has an impact on fetal and embryonic development in rats. The American Industrial Hygiene Association suggested an ELV of 2 ppm for THFA to prevent testicular degeneration in 1993 based on the No-observed-effect level of two subchronic investigations in rats and dogs
Deep eutectic solvents
DES components, according to Wazeer, Hayyan, and Hadj-Kali, are typically non-toxic and biodegradable. According to Hayyan et al., the DES they investigated were more harmful to the small crustacean artemia than each of their individual components, which could be attributed to synergy. The abbreviation NADES refers to DES that contain only materials sourced from renewable resources. Compared to other DES, these would typically be less hazardous.
Legislation
Due to the recency of green solvent development, few laws related to their regulation have been developed beyond standard workplace safety precautions already in place, and laws that enforce the use of green solvents have not been widespread.
References
Green chemistry | Green solvent | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 4,118 | [
"Green chemistry",
"Chemical engineering",
"Environmental chemistry",
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73,307,706 | https://en.wikipedia.org/wiki/Sodium%20p-toluenesulfonate | Sodium p-toluenesulfonate is an organic compound with the formula . It is white, water-soluble solid. It is produced by the neutralization toluenesulfonic acid with sodium hydroxide. It is also a common product from the reactions of sodium-based reagents with toluenesulfonates.
Heating this salt in strong base results in desulfonation, giving, after acid workup, p-cresol.
References
Sulfonyl groups
Leaving groups
Sulfonates | Sodium p-toluenesulfonate | [
"Chemistry"
] | 107 | [
"Substituents",
"Leaving groups",
"Functional groups",
"Sulfonyl groups"
] |
73,307,948 | https://en.wikipedia.org/wiki/Photoconductance%20decay | Photoconductance decay or Photoconductivity decay (PCD or PC), is a non-destructive analytical technique used to measure the lifetime of minority charge carriers in a semiconductor, especially in silicon wafers. The technique studies the transient photoconductivity of a semiconductor sample during or after it is illuminated by a light pulse. Electron–hole pairs are first generated by the light pulse, and the photoconductivity of the sample declines as the carriers recombine.
PCD is an important characterisation step in determining the quality and expected performance of wafers before they are used to fabricate devices such as integrated circuits or solar cells. It is one of the most common methods of determining carrier lifetimes.
PCD uses a fast light source (e.g. a xenon flash lamp) to excite the test sample, causing free carriers to be generated. Excess carriers in the material cause it to become more conductive, and thus the number of excess carriers () can be measured over time by measuring the material conductivity. Conductivity can be measured through non-contact methods, such as through microwave reflectance, or inductive or capacitive coupling. A higher effective lifetime of minority charge carriers indicate that they can remain mobile in the wafer for a long time period before undergoing recombination.
History
Characterisation of minority carrier lifetimes through measurement of photoconductance decay was a technique used by Bell Laboratories as early as 1954 on silicon and germanium wafers during investigation of carrier trapping. A detailed method for measuring PCD was published soon after by MIT Lincoln Laboratory in 1955. A standard method for PCD was described in ATSM standards in 1971 for measurement of minority carrier lifetimes. A new method for Quasi-steady-state photoconductance measurements was described in 1996 by Ronald Sinton.
Theory
The difference in dark and excited photoconductivity of the wafer is typically measured through monitoring of the voltage across the induction coil beneath the wafer. This yields a conductance that is spatially averaged over the coil area. Conductance can be related to the excess carrier generation by;
where and are excess electrons and holes, and are the electron and hole mobilities respectively, is the wafer thickness and is the elementary charge. It can be assumed that as electrons and holes are always generated in pairs.
When the conductance is obtained, the average can be calculated from the semiconductor parameters;
Depending on the expected lifetime of the material relative to the illumination decay characteristics of the flash lamp, there are several modes that can be used for PCD measurements.
The generalised equation for effective lifetimes as a function of the excess carrier density is given by;
where is the generation rate as measured by a photodetector. The generalised case can be used regardless of the wafer lifetime or flash lamp.
Alternatively, the limiting cases of this function can be exploited in either quasi-transient or quasi-steady-state photoconductance (QSS-PC) measurements.
Transient PCD is used when the of the material is expected to exceed the flash duration, and the PCD measurement is taken after the light source has completely decayed. In this case, is assumed to be 0, and Equation () can be reduced to;
For materials in which the effective lifetime is expected to be shorter than the flash lamp decay time, carriers are assumed to be continuously generated (i.e. at steady state), and therefore . Therefore, Equation () can be reduced to;
The case to be used is determined experimentally. The effective lifetimes is then calculated through curve fitting of the function and evaluated at a specified minority carrier density set-point, typically (see figure).
Applications
Recombination through the Shockley–Read–Hall (SRH) method is associated with the density of defects (such as contaminant atoms, dangling bonds, crystal grain boundaries, mechanical damage, etc.) in the semiconductor which "trap" charge carriers, leading to reduced lifetimes. Thus PCD can be used to infer the purity or passivation quality of the wafer. In solar cell production, this is particularly useful when estimating the performance of a precursor early in its manufacturing stage. Charge carriers that recombine cannot be used for photocurrent extraction, therefore for higher solar cell efficiency it is desirable to have a higher effective lifetime.
The minority carrier lifetime is also related to the open-circuit voltage of a solar cell, and therefore can be used to infer an implicit current–voltage characteristic of the finished solar cell.
Lifetimes measurements from PCD can be used to quantitatively calibrate spatially-resolved lifetimes measurements from Photoluminescence (PL) imaging. Minority carrier lifetimes are higher when there are fewer trap defects, and in the absence of SRH recombination, radiative recombination becomes more dominant. After excitation, radiatively recombining carriers emit nearly monochromatic light at the band gap energy of the semiconductor sample. For silicon, the energy is 1.12eV (in infrared) which can be captured by a CCD camera. Areas of the image with higher PL counts are inferred to have proportionately higher lifetimes.
See also
Transient photocurrent
References
Semiconductor technology | Photoconductance decay | [
"Materials_science"
] | 1,092 | [
"Semiconductor technology",
"Microtechnology"
] |
73,308,571 | https://en.wikipedia.org/wiki/Sodium%20benzenesulfonate | Sodium benzenesulfonate is an organic compound with the formula . It is white, water-soluble solid, It is produced by the neutralization benzenesulfonic acid with sodium hydroxide. It is also a common ingredient in some detergents. The compound typically crystallizes from water as the monohydrate.
Heating this salt in strong base results in desulfonation, giving, after acid workup, phenol This reaction was at one time, the principal route to phenol.
References
Sulfonyl groups
Leaving groups
Sulfonates | Sodium benzenesulfonate | [
"Chemistry"
] | 118 | [
"Substituents",
"Leaving groups",
"Functional groups",
"Sulfonyl groups"
] |
73,310,262 | https://en.wikipedia.org/wiki/Earnings%20at%20risk | Earnings at risk (EaR) and the related cash flow at risk (CFaR)
are measures reflecting the potential impact of market risk on the income statement and cash flow statement respectively, and hence the risk to the institution's return on assets and, ultimately, return on equity.
EaR measures the impact on net interest income due to movements in foreign exchange and interest rates; while CFaR measures possible shortfalls in cash flow due to these.
Both are calculated under simulation as for Value at Risk.
References
Mathematical finance
Financial risk modeling
Market risk
Monte Carlo methods in finance
Capital management
Financial management | Earnings at risk | [
"Mathematics"
] | 118 | [
"Applied mathematics",
"Mathematical finance"
] |
73,310,959 | https://en.wikipedia.org/wiki/Lanthanum%20oxalate | Lanthanum oxalate is an inorganic compound, a salt of lanthanum metal and oxalic acid with the chemical formula .
Synthesis
Reaction of soluble lanthanum nitrate with an excess of oxalic acid:
2La(NO3)3 + 3(COOH)2 -> La2(C2O4)3 + 6HNO3
Also, a reaction of lanthanum chloride with oxalic acid:
2LaCl3 + 3H2C2O4 -> La2(C2O4)3 + 6HCl
Physical properties
Lanthanum(III) oxalate forms colorless crystals that are poorly soluble in water.
The compound forms various crystallohydrates •n, where n = 1, 2, 3, 7, and 10.
The crystallohydrates decompose when heated.
References
Inorganic compounds
Oxalates | Lanthanum oxalate | [
"Chemistry"
] | 178 | [
"Inorganic compounds"
] |
66,049,979 | https://en.wikipedia.org/wiki/Nemmers%20Prize%20in%20Medical%20Science | The Mechthild Esser Nemmers Prize in Medical Science, established in 2016, is awarded every other year by Northwestern University Feinberg School of Medicine. The recipient is "a physician-scientist whose body of research exhibits outstanding achievement in their discipline as demonstrated by works of lasting significance". The winner is determined by a jury of biomedical scientists and receives $350,000. The award is one of five Nemmers Prizes awarded by the University, created as a gift to Northwestern by the late brothers Erwin Esser Nemmers and Frederic Esser Nemmers.
Nominations for the 2024 award are being accepted through November 1, 2023.
Awardees
The following recipients have received this award:
2016: Huda Zoghbi, MD
2018: Stuart Orkin, MD
2020: Not awarded
2022: Jeremy Nathans, MD, PhD
2024: Jeffrey I. Gordon
See also
List of medicine awards
References
Northwestern University's web page describing the origin of the Prize and biographical notes on Nemmers
Northwestern University's web page describing the Nemmers Prize in Medical Science
Northwestern University | Nemmers Prize in Medical Science | [
"Technology"
] | 225 | [
"Science and technology awards",
"Science award stubs"
] |
66,052,328 | https://en.wikipedia.org/wiki/Kaynemaile%20Architectural%20Mesh | Kaynemaile is a chainmail fabric consisting of polycarbonate interlinked rings connected together by liquid-state assembly to form a flexible mesh sheet. It is made from polycarbonate and used in the architecture and design industry. It was invented by Kayne Horsham in 2004.
History
The first prototypes of Kaynemaile were created within Weta Workshop's Creatures, Armor and Weapons department for The Lord of The Rings movie trilogy. Real metal chainmail was identified as too heavy for the actors to wear or do stunts. Kaynemaile was created as a chainmail fabric that looked and moved like real chainmail, but without the weight, made of polycarbonate resin rings with no joints or seams in the links. The material was created by a team of New Zealand based chainmail technicians manually interconnect millions of polypropylene (PP) rings and used electroplating process to apply silver on the outside. The result produced the realistic looking chainmail armor used throughout the movies. The new chainmail rings were incorporated into the costume design of characters such as Aragorn and Boromir, the Gondorian race and Rohan armies, and many of the Orcs. The chainmail was nicknamed “Kayne's-mail” by Viggo Mortensen.
Mass production
A company, Kaynemaile Ltd, was co-founded in 2006 by Kayne Horsham and Robyn Downham to streamline the process and make it commercially available, as architectural mesh. Its creation is now automated through a liquid-state injection molding fabrication process.
The mesh is used for to form large architectural building wraps, 3D shapes or seamless screens. It has been used as a lightweight, reflective, permeable membrane for buildings.
RE/8™ Bio-circular Architectural Mesh
In 2023, Kaynemaile changed its mesh material to one that is bio-circular. Named RE/8 Bio-circular Architectural Mesh, the new material is composed of a carbon neutral polycarbonate by Covestro, a producer of advanced polymers.
Awards
Fast Company Innovation by Design Awards 2024, Honoree in categories: Biodesign, Circular Design, Materials
Architizer A+ Awards 2024, Jury Winner in Building Envelopes, Cladding & Roofing
Architizer A+ Awards 2024, Popular Choice Winner in Sustainable Design
Architectural Record Products of the Year 2023, Winner in Building Systems and Components in recognition of its full-scale sustainability initiatives
The Wellington Gold Awards 2023, Winner Global Gold
Civil + Structural Engineer YEA Award 2022, Winner in Environmental / Sustainability category
Architizer A+ Awards 2020, Product Winner in Facades, Building Envelopes & Cladding
Architecture MasterPrize 2019, Winner in Building Envelope & Construction Materials
Wellington Gold Awards 2018, Finalist Global Gold
NYCxDesign Award 2017, Best Architectural Product
designEX Award 2014, Best New Innovative Product
New Zealand Plastics Industry Design Award 2008, Gold
Designpreis Halle Award 2008, Nominee
iF Design Award 2007, Discipline: Material
References
The Lord of the Rings (film series)
Materials
New Zealand design | Kaynemaile Architectural Mesh | [
"Physics"
] | 633 | [
"Materials",
"Matter"
] |
66,053,187 | https://en.wikipedia.org/wiki/DGS%20Mastodon | DGS Mastodon was a dredge, operated by the Government of Canada, keeping shipping channels clear in British Columbia. She was ordered in 1909, from the Scottish shipyard William Simons and Company, and commissioned on May 13, 1911.
From 1912 to 1917 she was employed widening Vancouver's first narrows, expanding the safe shipping channel from to .
In 1942 she was transferred to the Royal Canadian Navy. In 1946 she was sold to Imperial Oil, who then sold her to International Petroleum Company Limited, of Callao, Peru. In 1963 she was scrapped, in Lima, Peru.
References
Dredges
Mastodon | DGS Mastodon | [
"Engineering"
] | 125 | [
"Dredges",
"Mining equipment"
] |
66,053,843 | https://en.wikipedia.org/wiki/Gamma%2060%20wind%20turbine | The Gamma 60 wind turbine, a 1.5 MW two-bladed upwind horizontal axis wind turbine, was installed by Wind Energy Systems Taranto S.p.A. (WEST) at Alta Nurra, Sardinia, Italy in April 1992. Founded on original research and development work by NASA and Hamilton Standard (then a division of United Technologies Corporation), the Gamma 60 wind turbine was the world's first variable speed wind turbine with a teetering hinge.
The Gamma 60 wind turbine was commissioned to assess the feasibility and performance of power regulation through yaw control, rather than industry-standard blade pitch control, including broad range variable speed in a two-bladed teetering hinge wind turbine.
The WEST Gamma 60 wind turbine project team included Hamilton Standard, ENEL, Aeritalia, Finmeccanica (now Leonardo), ENEA (Italy), and Sulzer.
Three Gamma turbines were manufactured, and one was erected and successfully tested from 1992 - 1997 on the Mediterranean island of Sardinia. Commercialization of the Gamma 60 prototype was planned, including a conditional investment for 10 Gamma turbines by a US utility, but legal disputes and contractual claims between WEST and ENEL, the privatization of ENEL, and tumbling oil prices in 1998 resulted in the program's cancellation.
Overview
The Gamma 60 wind turbine's technology stems from Glidden Doman’s flexible two-bladed turbine system design that is compliant with the forces of nature rather than resistant to them. Doman, along with noted German-born aerospace engineer Kurt Hohenemser (a partner and confidant of the well-known German airplane and helicopter designer Anton Flettner), maintained that a flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces of nature was more suitable for producing electricity than the rigid industry standard three-bladed airplane type wind turbine rotors that, by design, can only be constructed to resist the forces of nature.
Gamma's robust design simplicity, which supports higher turbine rotation speeds, achieves lower torque, lower fatigue, a lighter drive train, and a longer life due to the teetering hub technology. The Gamma 60's teetering hub technology works in conjunction with an innovative yaw power control system that eliminates blade pitch control mechanisms.
Gamma's teetering hub, which adds a degree of freedom to the turbine, dramatically reduces torque required to yaw the nacelle and greatly reduces the loads on the blades, drivetrain, and nacelle. The Gamma 60 was designed for high wind power output, long life, low investments, and reduced maintenance costs to satisfy the requirements of electricity utilities.
History of Development
Evolution of the Gamma 60 wind turbine can be traced back to World War II when Sikorsky Aircraft (now owned by Lockheed Martin, but then a division of United Technologies Corporation) hired American engineer Glidden Doman to address helicopter structural and dynamic problems including blade failures. Igor Sikorsky developed and flew the first successful helicopter in the United States during 1939.
Doman founded one of America's original six helicopter companies (Doman Helicopters, Inc.) after making major contributions to the use of Sikorsky helicopters during World War II. Doman's initial helicopter, the LZ-1A - a Sikorsky R-6 converted to a Doman rotor and control system, first flew in 1947. The LZ-1A was followed in development by the LZ-4 in 1950. Doman Helicopters' most prominent achievement was the Doman LZ-5/YH-31 eight-place helicopter, which received FAA certification on December 30, 1955. The unique feature of this helicopter was its hinge-less but gimbaled, tilting rotor hub that greatly reduced stress and vibration in the blades and in the whole helicopter.
Two-bladed, teetering hinge rotor designs have been used extensively in helicopters, most notably in numerous models and many thousands of helicopters built by the Bell Helicopter company. The Bell 47, with its distinctive "soap bubble" cockpit canopy windshield, was used in the Korean War (e.g. MEDEVAC missions, in M*A*S*H series, and one is on display at the Museum of Modern Art in New York) and the Bell 204 was used extensively in the Vietnam War.
Bell's two-bladed rotor with a teetering hinge and Doman Helicopters' four-bladed rotor with a gimbaled hinge, offered similar benefits in reducing stresses in the rotor blades and preventing much of the stress from being transmitted to the fuselage. Glidden Doman believed that the four-bladed rotor was smoother during a helicopter's forward flight, but since wind turbines are not involved in forward flight, the two-bladed wind turbine design offered the same benefits with greater simplicity. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5/YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut.
NASA Research & Development
Glidden Doman was one of the first to transfer knowledge of helicopter rotor dynamics technology to wind turbines. In 1973, the Middle East oil embargo escalated interest in wind energy technology development. From 1974 - 1981, the NASA Glenn Research Center, formerly the Lewis Research Center in Cleveland, Ohio, initiated a US wind energy program for the development of utility-scale horizontal axis wind turbines.
A 1975 National Science Foundation (NSF) contract provided Glidden Doman with funding to explore wind turbine structural dynamics with the objective to eliminate the possibility of wind turbine blade failures due to turbulence. Boeing's MOD-2 with the Doman-conceived flexible design, two-bladed wind turbine with a teetering hinge, became a flagship achievement in this 7-year NASA managed wind energy program for the U.S. Department of Energy and the U.S. Department of the Interior.
Two-bladed wind turbines
WTS-4
In 1978, Glidden Doman was hired by Hamilton Standard to design wind turbines. In 1982, Hamilton Standard installed the WTS-4, a 4.2 MW two-bladed wind turbine in Medicine Bow, Wyoming. . The WTS-4, the first 4 MW wind turbine installed anywhere in the world, was a downwind horizontal-axis wind turbine with a teetering hub, soft steel tower, and pitch power control. This turbine was fabricated for the U.S. Department of Interior, Bureau of Reclamation, by United Technologies’ Hamilton Standard division as a potential forerunner of a number of wind turbines to be installed at Medicine Bow, Wyoming in a long-range plan to integrate wind power with hydroelectric power.
WTS-3
After an intense competition involving 5 European consortium competitors, the team of Hamilton Standard and the Swedish shipyard Karlskronavarvet (now Saab Kockums) was awarded a contract to develop the WTS-3, a two-bladed, downwind, horizontal-axis wind turbine rated at 3 MW. In 1983, Karlskronavarvet installed the WTS-3 in the town of Maglarp, Sweden. The WTS-3, which was developed in cooperation with US based Hamilton Standard, also featured a soft steel tower that has become the standard for multi-MW wind turbines.
Hamilton Standard’s contribution to this program was the overall system design, the mechanical design of the rotor and pitch change system, and fabrication of the blades. The WTS-3 (50 Hz) and WTS-4 (60 Hz) were essentially the same turbine (i.e. filament winding blades, mechanical-hydraulic pitch mechanism system, teetering hinge, and soft tower) with different fixed speeds. This turbine was decommissioned in 1993 after it generated 37 GWh during it 11 years of operation, at the time, a world record for wind turbines.
WTS-75/Näsudden I
The other bid winner was Karlstads Mekaniska Werkstad KMW (also known as Kamewa), which proposed a 75 m, two-bladed, upwind turbine with a beveled gear that enabled placing the asynchronous generator inside the tower rather than the nacelle. In 1984, the WTS-75, a 2 MW wind turbine, started operations in Näsudden on the south coast of Gotland, Sweden. As was the case with the WTS-3, a number of components of the WTS-75 wind turbine had to be repaired or modified within the first years of operation. The WTS-75, like most other multi-MW wind turbines during its era, did not have a teetering hinge and had a stiff tower that was made of concrete, which was considerably thicker than soft steel towers.
The stiff WTS-75 system design without damping was problematic, possibly contributing to the cracks that appeared in the steel beams of the blades. Cracks in the blades were repaired by welding but ultimately, in 1988, the operation had to be halted after a crack appeared close to the hub in one of the blades. In 1991, main turbine components were dismantled but the concrete tower was left and reused for the Näsudden II.
The WTS-4 was the most powerful wind turbine to have operated onshore in the US and it held the world record for power output for over 20 years. Toward the end of the WTS-4 project, NASA provided Doman with funding to explore broad range variable speed. The outcome of Doman's work was a strong patent in his name and the conclusion that such a variable speed system (i.e. the Gamma turbine) should be developed.
After an extensive due diligence review, Enel (Italy's largest utility) and Aeritalia bought a license from United Technologies and moved Glidden Doman to Italy where the Gamma 60 technology was designed and demonstrated under Wind Energy Systems Taranto SpA (WEST).
Gamma 60 Project
Gamma, the Italian acronym for WEST's (Wind Energy Systems Taranto SpA) project - “Advanced Multi Megawatt Wind Generator” (Generatore Anemoelettrico Multi Megawatt Avanzato), began in 1986 and explored all available technology to create a turbine design optimized for economic performance. In this program, Glidden Doman applied his latest thinking to a new machine, considerably improved over the WTS-4 and WTS-3 machines he had designed for installation in Wyoming and Sweden respectively. Under Doman's leadership a team of Italian engineers designed the Gamma 60 turbine. The Gamma 60 wind turbine adopted the upwind configuration and variable speed concept from the WTS-75, the filament winding blade technology from the WTS-4 and WTS-3, and the teetering hinge with elastomeric material from Glidden Doman’s helicopter technology. Based on direct and indirect experiences spanning 50 years, Doman concluded that upwind turbine configuration is better than downwind from a loading standpoint and that zero Delta three angle is important for rotor stability.
The Gamma 60 was the world's first variable speed wind turbine with a teetering hinge. A primary objective of the Gamma 60 project was to test power control of a two-bladed teetering hinge turbine by yawing the rotor rather than pitching the blades.
Gamma’s technology is based on Doman’s design philosophy of compliance with the forces of nature in its teetered hub, flexible tower, and broad-range variable-speed power train rather than resistance to these forces, which is prevalent in 3-bladed Danish turbine designs. Doman’s work was further inspired by German aerospace engineer Kurt Hohenemser who declared that wind turbines should be two-bladed, fixed pitch, and controlled by yawing to achieve the highest reliability. Dr. Hohenemser, along with his mentor Anton Flettner, developed helicopters for the U.S. military after being among the first German immigrants in the United States after World War II.
Gamma’s turbine consists of two blades which are rigidly interconnected with each other through the hub, but there is a teetering hinge between the hub and the shaft. The resulting free teetering of the rotor eliminates certain greatly variable aerodynamic forces on the blades that would otherwise occur. It also precludes any significant vibratory forces reaching the rotor shaft, the nacelle, or the tower.
Glidden Doman successfully replicated the benefits associated with the four-bladed helicopter rotor with a gimbal hinge, while also recognizing advantages inherent in two-bladed helicopter rotors, in the development of the Gamma 60 two-bladed rotor with a teetering hinge.
The 1.5 MW Gamma 60 HAWT started operating at Alta Nurra, Sardinia, Italy in July 1992. Power from the Gamma 60 turbine is controlled by yawing the rotor, a maneuver made possible by the load alleviation resulting from the soft-system design. Features including the teetering hinge that eliminate major vibratory loading, allow a Gamma system to be very lightweight and yet have essentially infinite fatigue life. The teetering hinge, along with the lower shaft torque due to higher running speed, leads to a very lightweight system.
Broad range variable speed allows Gamma to operate at rotational speeds proportional to the wind speed. This allows the Gamma turbine to be noticeably quiet when the wind is moderate and to run faster under high wind conditions.
Since there are no blade pitch control mechanisms in the rotating system, the Gamma turbine’s reliability and maintainability are superior. Moreover, Gamma has important intrinsic safety values that come from the simplicity of its features and from the rotor which is designed to be unharmed even in case of a free running overspeed under the most severe load case. In fact, because a Gamma system feels no ill effects from turbulence even at high running speed, there is no need to set a cutout speed at which it must be shut down.
NASA recognized the accomplishments of Gamma by featuring it with a detailed description in ASME publication “Wind Turbine Technology: Fundamental Concepts in Wind Turbine Engineering” edited by David A. Spera.
Gamma 60 Design Data
Sources:
Project Investment
The total investment amount for the Gamma 60 wind turbine project, ITL ₤39,000 million (US$30 million), was provided in two tranches. On October 10, 1986, a contract in the amount of ITL ₤20,000 million ITL (US$15.385 million) contract was signed between Aeritalia, Fiat Aviazione, and ENEA (Italy) to develop the Gamma 60. On March 12, 1987, a contract in the amount of ITL £19,000 million (US$14.615 million) was signed between Aeritalia, Fiat Aviazione, and Enel to uprate and improve the Gamma 60 with 2 Gamma 2000 (2 MW) wind turbines.
Funding for the Gamma 60 project contracts was provided by Enel - ITL ₤15,000 million (US$11.538 million); ENEA (Italy) – ITL ₤10,500 million (US$8.077 million); the European Community – ITL ₤10,500 million (US$8.077 million); and industrial partners – ITL ₤3,000 million (US$2.308 million). As participants in the project team, ENEA (Italy) provided research and development; Hamilton Standard contributed with system design, control software, and blade manufacturing; Sulzer fabricated the shaft and yaw drives, Finmeccanica (via Ansaldo) manufactured the generator and control system. Enel’s role, in addition to being a customer for the electricity produced, was in technological supervision of Gamma 60’s development, operation of the Gamma 60; Enel was also earmarked to install and operate the Gamma 2000 (2 MW) turbines. On July 03, 1990, Aeritalia, after acquiring Fiat Aviazione, transferred the ownership of its wind turbine business to Wind Energy Systems Taranto SpA (WEST).
Project Milestones
The WEST Gamma 60 prototype was installed at Alta Nurra, Sardinia, Italy in April 1992 and was followed by its very first grid connection in June 1992. After commissioning, the operation of the turbine gradually increased in terms of rated power, until 1500 kW was reached in August 1994.
Source:
Through October 1, 1997, the Gamma 60 produced to the grid 4,390 hours (generator hours) and 1,318 MWh as illustrated in the table below.
Project Conclusions
In 1997, Silvestro Caruso, an Italian nuclear mechanical engineer who was assigned by Finmeccanica (now Leonardo SpA) for an independent review of the Gamma 60 turbine concluded, with Glidden Doman and the design review team, that Gamma technology has great potential. Further development to reduce costs (optimized blade molds and filament winding upgrades) and improve performance (increased maintainability, more reliability & redundancy in the electrical and electronic field) were identified targets for industrialized Gamma wind turbines. The WEST team, under the leadership of Glidden Doman, successfully replicated the benefits associated with the four-bladed helicopter rotor with a gimbal hinge, while also recognizing advantages inherent in two-bladed helicopter rotors, in the development of the Gamma 60 two-bladed rotor with a teeter hinge and yaw power control.
The scope of the Gamma 60 project contract between WEST and ENEL was to test the Gamma 60 yaw control system and to uprate the resulting prototype to 2 MW with improvements to make the wind turbine suitable for commercial production. However, WEST manufactured the Gamma 2000 turbines just like the Gamma 60, only increasing the running speed without any improvements. Plans to commercialize the prototype were well underway prior to the end of the Gamma 60 project. ENEA (Italy), since the beginning with the partially fabricated two Gamma 2000 turbines, requested that WEST continue with its commitment for development and production of large utility-scale wind turbines. Additionally, a US utility, after reviewing a cost saving study and price quotation, requested to buy a set of 10 Gamma wind turbines under the condition that the units would not be left “orphaned” by West. However, Finmeccanica could not guarantee this commitment because it considered the business too unprofitable due to depressed oil prices in 1998. Commercialization plans for the Gamma 60 prototype were halted, including a conditional investment for 10 Gamma turbines by a US utility, because of legal disputes and contractual claims between WEST and Enel, the privatization of Enel, and tumbling oil prices in 1998.
Post Gamma 60 Project Development
In 2004, Glidden Doman and Silvestro Caruso decided to acquire from Finmeccanica (through Ansaldo) the rights for the Gamma technology, along with the technical documentation and two yet to be completed 2 MW Gamma turbines. For this acquisition, along with other shareholders, they founded and launched Gamma Ventures, Inc.
After some revisions in corporate structures and plans, the Gamma rights were eventually transferred to a new company, Seawind Ocean Technology B.V., which is working on placing turbines with Gamma type rotors (Seawind 6-126 and Seawind 12-225) on self-installing concrete offshore floating wind turbine support structures, aiming to do so in numerous locations around the world.
See also
NASA wind turbines
Offshore wind power
Variable speed wind turbine
Floating wind turbine
Wind power
References
External links
Wind turbine manufacturers
Floating wind turbines
Wind power companies
Italian companies established in 1986
Renewable resource companies established in 1986 | Gamma 60 wind turbine | [
"Engineering"
] | 4,002 | [
"Floating wind turbines",
"Offshore engineering"
] |
66,053,979 | https://en.wikipedia.org/wiki/Gate%20capacitance | In electronics, gate capacitance is the capacitance of the gate terminal of a field-effect transistor (FET). It can be expressed as the absolute capacitance of the gate of a transistor, or as the capacitance per unit area of an integrated circuit technology, or as the capacitance per unit width of minimum-length transistors in a technology.
In generations of approximately Dennard scaling of metal-oxide-semiconductor FETs (MOSFETs), the capacitance per unit area has increased inversely with device dimensions. Since the gate area has gone down by the square of device dimensions, the gate capacitance of a transistor has gone down in direct proportion with device dimensions. With Dennard scaling, the capacitance per unit of gate width has remained approximately constant; this measurement can include gate–source and gate–drain overlap capacitances. Other scalings are not uncommon; the voltages and gate oxide thicknesses have not always decreased as rapidly as device dimensions, so the gate capacitance per unit area has not increased as fast, and the capacitance per transistor width has sometimes decreased over generations.
The intrinsic gate capacitance (that is, ignoring fringing fields and other details) for a silicon-dioxide-insulated gate can be calculated from thin-oxide capacitance per unit area as:
where:
is the gate area
is the thin-oxide capacitance per unit area, where
is the relative permittivity of silicon dioxide
is the vacuum permittivity
is the oxide thickness.
References
Semiconductor technology | Gate capacitance | [
"Materials_science"
] | 344 | [
"Semiconductor technology",
"Microtechnology"
] |
66,054,232 | https://en.wikipedia.org/wiki/WASP-58 | WASP-58 is a binary star system comprising a G-type main-sequence star and a red dwarf about 955 light-years away. WASP-58 is slightly depleted in heavy elements, having 80% of the solar abundance of iron. WASP-58 is much older than the Sun at 12.80 billion years.
Lithium was detected in the stellar spectrum of WASP-58A, making the star anomalous for its advanced age.
A multiplicity survey in 2015 did detect a red dwarf stellar companion at a projected separation of 1.281″ to WASP-58A, and it was confirmed to be gravitationally bound in 2016.
Planetary system
In 2012 a transiting hot Jupiter planet b was detected on a tight, circular orbit around the primary star WASP-58A.
Planetary equilibrium temperature is .
References
Lyra
Solar analogs
G-type main-sequence stars
Binary stars
Planetary systems with one confirmed planet
Planetary transit variables
J18184825+4510192 | WASP-58 | [
"Astronomy"
] | 198 | [
"Lyra",
"Constellations"
] |
66,054,581 | https://en.wikipedia.org/wiki/Feng%20Yunhe | Feng Yunhe (1898/ April 1900 – 14 December 1988) was a Chinese scientist who worked in the Chinese government from 1949–1954 as the Minister of Textile Industry. Alongside Shi Liang and Li Dequan, who were appointed the same year, she was the first female cabinet minister in China (not counting He Xiangning, who served prior to unification). Feng Yunhe was an expert in ramie fibre. She was one of the founders of the China National Democratic Construction Association, one of the eight legally recognised minor political parties in the People's Republic of China. She was the first woman on record to earn a PhD in chemical engineering in the United States.
Early life and education
Feng Yunhe hailed from Lijin, Shandong Province in China. She attended primary and secondary school at the Jinan Girls' Junior Normal School and the Beijing Girls' Higher Normal School. In 1920 she was admitted to the United States to study chemical engineering at Ohio State University, where she received her master's degree in 1928 and her doctorate in chemical engineering in 1931, making her the first woman to obtain a doctoral degree in chemical engineering in the United States. Whilst in America, she was known as Yun Hao Feng or Ruth Feng. In 1930 she and Mary Bucher were members of the American Institute of Chemical Engineers Student Chapter in Ohio, the first cohort group to allow female membership.
Career
After graduating, she returned to China and taught at Yanjing University, where she went to the University of Berlin, Germany in 1933 to conduct research on rayon and invented the first rayon made from grass fibres, returning to China in 1936 to serve as a commissioner of the Central Economic Commission. In 1938 she moved to Chongqing to set up the Southwest Chemical Industry Manufacturing Factory, where she conducted research on ramie processing and eventually spun out the "Cloud Silk", known as Yunsi fiber. In 1949, she attended the First Plenary Session of the Chinese People's Political Consultative Conference.
After the founding of the People's Republic of China, Feng Yunhe became an advisor to the Ministry of Textile Industry and Deputy Director of the Guangdong Chemical Research Institute, and in 1951, she began researching the chemical denaturation of ramie fibres, which was successful after five years of experiments. During the Cultural Revolution, she was branded as a "reactionary academic authority". After the end of the Cultural Revolution, she became a consultant to the Shanghai Textile Industry Bureau's Wool and Hemp Textile Industry Company and joined the Chinese Communist Party in 1979. She was awarded the invention prize by the State Science and Technology Commission in 1981 for the development of a large number of ramie fibre sulphonation denaturation products in Shanghai, and was a technical advisor to Hubei Province on textile technology from 1984.
Political positions
Feng Yunhe was a member of the First to Third National People's Congress, a member of the Standing Committee of the Fifth National Committee of the Chinese People's Political Consultative Conference and a member of the Sixth National Committee of the Chinese People's Political Consultative Conference.
Feng Yunhe died in Guangzhou in on 14 December 1988 at the age of 89.
References
1898 births
1988 deaths
Members of the China Democratic League
Women government ministers of China
20th-century Chinese politicians
20th-century Chinese women politicians
Ohio State University College of Engineering alumni
Women engineers
Chinese women engineers
Chemical engineers
Chinese Communist Party politicians from Shandong | Feng Yunhe | [
"Chemistry",
"Engineering"
] | 686 | [
"Chemical engineering",
"Chemical engineers"
] |
66,054,739 | https://en.wikipedia.org/wiki/Vermitechnology | Vermitechnology is an overarching term for the following subtopics:
Vermifiltration: A process for purifying effluent that utilises earthworms (also called vermidigestion)
Vermicomposting: Utilising earthworms for composting organic material
Vermiculture: the commercial rearing of earthworms to be used for other processes e.g. fishing
Vermitechnology includes the study and commercial application of technologies that utilise earthworms for degrading waste organic materials for sanitation and agricultural re-use. Organic wastes degraded and stabilised by earthworms include those suspended or dissolved in water and also solid organic material.
References
Annelids
Soil biology | Vermitechnology | [
"Biology"
] | 154 | [
"Soil biology"
] |
66,055,386 | https://en.wikipedia.org/wiki/WASP-57 | WASP-57 is a single G-type main-sequence star about 1310 light-years away. WASP-57 is depleted in heavy elements, having 55% of the solar abundance of iron. WASP-57 is much younger than the Sun at 0.957 billion years.
A multiplicity survey in 2015 did not detect any stellar companions to WASP-57.
Planetary system
In 2012 a transiting hot Jupiter planet b was detected on a tight, circular orbit around WASP-57.
Planetary equilibrium temperature is .
References
Libra (constellation)
G-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
J14551682-0203275 | WASP-57 | [
"Astronomy"
] | 138 | [
"Libra (constellation)",
"Constellations"
] |
66,055,636 | https://en.wikipedia.org/wiki/WASP-54 | WASP-54, also known as BD+00 3088, is a binary star system about 825 light-years away. The primary, WASP-54A, is a F-type main-sequence star, accompanied by the red dwarf WASP-54B on a wide orbit. WASP-54 is depleted in heavy elements, having 55% of the solar abundance of iron. The age of WASP-54 is slightly older than the Sun's at 6.9 billion years.
A multiplicity survey in 2017 did detect a red dwarf stellar companion WASP-54B 5.7″ away from WASP-54A. The companion was proven to be co-moving in 2020.
Planetary system
In 2012 a transiting hot Jupiter planet b was detected on a tight, mildly eccentric orbit around WASP-54A.
Planetary equilibrium temperature is .
References
Virgo (constellation)
F-type main-sequence stars
Binary stars
Planetary systems with one confirmed planet
Planetary transit variables
J13414903-0007410
Durchmusterung objects | WASP-54 | [
"Astronomy"
] | 213 | [
"Virgo (constellation)",
"Constellations"
] |
66,056,365 | https://en.wikipedia.org/wiki/Speibecken | A Speibecken or Kotzbecken is a basin for people to vomit into. These sinks are installed in some bars, restaurants and student fraternities in German-speaking countries as well as in bars in Vietnam.
The Speibecken is often a large ceramic bowl installed at waist height with handles for the user to hold onto and a shower head to flush the unit. They are encountered more often in men's facilities than in women's.
In Germany and Austria they have become associated with the heavy drinking traditions of student fraternities. They have also been provided at supervised injection sites for drug users.
Names
Speibecken comes from the German speien ("to spit" but also "to vomit") and Becken ("bowl, basin"). The term also has the meaning of the traditional spittoon, used by tobacco chewers or in dentist's surgeries. In some parts of Austria and Germany they are known as Kotzbecken (from kotzen, "to puke"). In Vietnam they are called bồn ói [nôn], meaning "puke sink".
Speibecken are nicknamed Papst ("pope") often said to be because people must bow their heads to use them. In some German-speaking regions vomiting is known as papsten ("poping"). The shower head fixed nearby to flush the Speibecken is also nicknamed "large white telephone".
References
Bathroom equipment
Plumbing
Vomiting | Speibecken | [
"Engineering"
] | 310 | [
"Construction",
"Plumbing"
] |
66,056,960 | https://en.wikipedia.org/wiki/Bamlanivimab | Bamlanivimab is a monoclonal antibody developed by AbCellera Biologics and Eli Lilly as a treatment for COVID-19. The medication was granted an emergency use authorization (EUA) by the US Food and Drug Administration (FDA) in November 2020, and the EUA was revoked in April 2021.
Bamlanivimab is an IgG1 monoclonal antibody (mAb) directed against the spike protein of SARS-CoV-2. The aim is to block viral attachment and entry into human cells, thus neutralizing the virus, and help preventing and treating COVID-19.
Bamlanivimab emerged from the collaboration between Lilly and AbCellera to create antibody therapies for the prevention and treatment of COVID-19.
Bamlanivimab is also used as part of the bamlanivimab/etesevimab combination that was granted an EUA by the FDA.
In June 2021, the US Office of the Assistant Secretary for Preparedness and Response (ASPR) paused distribution of bamlanivimab and etesevimab together, and etesevimab alone (to pair with existing supply of bamlanivimab), due to the increase of circulating variants.
Studies
Bamlanivimab has been studied in several trials. Some initial results on bamlanivimab seemed promising, with one review saying that it "decrease[s] viral load when given early on in the course of SARS-CoV-2 infection and favourably impact[s] clinical outcomes for patients with mild-to-moderate COVID-19". However, further results have not shown any clinically relevant benefit.
Animal trials
An initial trial tested bamlanivimab in rhesus monkeys. Administration of the drug reduced SARS-CoV-2 replications in the upper and lower respiratory tract of monkeys.
Human trials
BLAZE-1 Trial
The Blocking Viral Attachment and Cell Entry with SARS-CoV-2 Neutralizing Antibodies (BLAZE-1) trial was sponsored by the drug's developer Eli Lilly. The drug was tested in SARS-CoV-2 patients who did not require hospitalization. While an interim analysis suggested reduced ER visits and hospitalizations, this difference was not statistically significant in the final analysis. A subsequent analysis demonstrated superior efficacy of a combination of bamlanivimab and etesevimab compared to placebo.
ACTIV-2 Trial
This study is sponsored by the NIH, examining bamlanivimab administration to SARS-CoV-2 patients in the outpatient setting. The study is ongoing and no data have been released yet.
ACTIV-3 Trial
This study specifically examined bamlanivimab in hospitalized COVID-19 patients without severe illness (e.g. end organ damage); these patients were also receiving the standard of care at the time including supportive care, remdesivir, supplemental oxygen, and dexamethasone as indicated. Enrollment was stopped early due to futility; bamlanivimab was not found to increase sustained recovery (90 days), and did not change pulmonary function. The study was funded by Operation Warp Speed.
Authorization
On 7 October 2020, Eli Lilly and Company submitted a request for an Emergency Use Authorization (EUA) to the U.S. Food and Drug Administration (FDA) for LY-CoV555 monotherapy in higher-risk people who have been diagnosed with mild-to-moderate COVID-19. This authorization was largely done on the basis of the interim BLAZE-1 results showing possible benefit. However, further data obtained after the EUA was granted have not shown any clinically relevant benefit from bamlanivimab.
On 9 November 2020, bamlanivimab was granted an emergency use authorization by the US Food and Drug Administration (FDA) for the treatment of mild-to-moderate COVID-19 in adults and adolescents. Bamlanivimab is authorized for people with positive results of direct SARS-CoV-2 viral testing who are twelve years of age and older weighing at least , and who are at high risk for progressing to severe COVID-19 or hospitalization. This includes those who are 65 years of age or older, or who have certain chronic medical conditions.
On 16 April 2021, the FDA revoked the emergency use authorization (EUA) that allowed for the investigational monoclonal antibody therapy bamlanivimab, when administered alone, to be used for the treatment of mild-to-moderate COVID-19.
Bamlanivimab/etesevimab
On 9 February 2021, the FDA issued an emergency use authorization (EUA) for bamlanivimab and etesevimab administered together for the treatment of mild to moderate COVID-19 in people twelve years of age or older weighing at least who test positive for SARS‑CoV‑2 and who are at high risk for progressing to severe COVID-19. The authorized use includes treatment for those who are 65 years of age or older or who have certain chronic medical conditions.
On 1 February 2021, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) started rolling reviews of data on the use of the monoclonal antibodies casirivimab/imdevimab, bamlanivimab/etesevimab, and bamlanivimab for the treatment of COVID-19. On 29 October 2021, Eli Lilly withdrew bamlanivimab and etesevimab from the European Medicines Agency rolling review process.
Deployment
On 28 October 2020, Eli Lilly and Company announced that it had struck a deal with the US government to supply 300,000 vials of bamlanivimab 700 mg for million.
Society and culture
Names
Bamlanivimab is the international nonproprietary name (INN).
References
Antiviral drugs
Experimental monoclonal antibodies
COVID-19 drug development | Bamlanivimab | [
"Chemistry",
"Biology"
] | 1,236 | [
"Antiviral drugs",
"COVID-19 drug development",
"Biocides",
"Drug discovery"
] |
66,056,968 | https://en.wikipedia.org/wiki/International%20Conference%20of%20Women%20Engineers%20and%20Scientists | ICWES (International Conference of Women Engineers and Scientists) is an international conference for engineers and scientists. Established in 1964, it takes place every 3–4 years in countries around the world.
Since 1999, the conference has been organised by the International Network of Women Engineers and Scientists (INWES), which was founded at the World Conference on Science (Budapest, Hungary) in 1999. The first conference took place in New York City, USA in 1964, the second followed in 1967 in Cambridge, UK. Since then meetings have taken place in Turin, Italy (1971); Cracow, Poland (1975); Rouen, France (1978); Mumbai, India, (1981); Washington DC, USA (1984); Abidjan, Ivory Coast (1988); Warwick, UK (1991); Budapest, Hungary (1996); Chiba, Japan (1999); Ottawa, Canada (2002); Seoul, Korea (2005); Lille, France (2008); Adelaide, Australia (2011); Los Angeles, USA (2014); New Delhi, India (2017). ICWES 18 was postponed due to the Covid pandemic and took place in Coventry, UK, in 2021. ICWES 19 was hosted in Aotearoa, New Zealand in 2023.
ICWES I - New York City
The first ICWES conference took place in New York City, United States of America in 1964 and was organised by the American Society of Women Engineers (SWE). Beatrice Hicks was Conference Director and Ruth Shafer was Operations Chairman. The Technical Program was managed by Margaret R. Fox and the PR by Elsie Eaves. The theme of the conference was on developing engineering and scientific talent for the future.
There were 493 listed attendees from 35 different countries, including Lillian Gilbreth, Beatrice Hicks, Grace Hopper, Ayyalasomayajula Lalitha, and Isabel Hardwich. The conference received funding from the National Science Foundation, the Asia Foundation, the Engineers Joint Council, as well as other companies and individual donations. Included in the conference programme was a trip to the New York's World Fair, which was taking place at the same time. The conference proceedings published a message sent to the conference from Lyndon B. Johnson, which stated that 'in focusing on the untapped potential and ability of talented women to participate in these professional activities, you and your colleagues are performing a distinguished service in our society'.
Talks and statements were given by a variety of women from different countries, including Lillian Gilbreth (USA), Ira Rischowski (UK), Isabel Hardwich (UK), Cicely Thompson (UK) Jacqueline Juillard (Switzerland), Dorothy Mizoguchi (Japan), Ilse Knott-ter Meer (West Germany), Olwen Wooster (Australia), Maria Telkes (US), Anna Amour (Italy) and Francisca Fernández-Hall, a civil engineer and Guatemalan ambassador to Israel.
ICWES II - Cambridge
The second ICWES conference was organised by the United Kingdom's Women's Engineering Society (WES) and took place in Cambridge, England in 1967. The themes of the conference were the application of technology to solve world food problems and the question of women's representation in engineering and science across the world. There were 309 listed attendees from 35 different countries, with attendees including Ghanaian zoologist Leticia Obeng, Ugandan engineer Miriam Muwanga, Japanese geochemist Katsuko Saruhashi, American aeronautical engineer Katherine Stinson, Betty Lou Bailey who worked for General Electric Company and engineer and journalist Elsie Eaves and Indian mechanical engineer Ila Ghose and K. K. Khubchandani. Nigerian physicists Deborah Ajakaiye and Ebun Adegbohungbe also attended. In The Woman Engineer – journal of WES – Leticia Obeng commented on the atmosphere of the conference: 'The change from the serious talks in the Chemistry Laboratory Hall to the gay atmosphere at the pre-banquet reception was a vivid demonstration of the adaptability of the human female to varying conditions.' British attendees included engineers Isabel Hardwich, Ira Rischowski (who was accommodation secretary), Rose Winslade, Cicely Thompson, and Hettie Bussell. No delegates attended from Russia due to the Six-Day War.
ICWES III - Turin
The third International Conference of Women Engineers and Scientists was held in Turin, Italy ( 30 August - 5 September 1971), organised by Dr Anna Amour and AIDIA (the Italian Association for Women in Engineering and Architecture), and supported by the late Dr. Emma Strada. Attendees included Erna Hamburger, Letitia Obeng, Nicole Becarud, Deborah Ajakaiye, Ebun Oni (née Adegbohungbe), Olive Salembier, Azarmidokht Arjangi, May Maple, Hettie Bussell, Irene Ryan, Peggy Hodges, Elizabeth Laverick, Daphne Jackson, Grace Hopper, Veronica Milligan.<ref></ref and Elsie Eaves.ref></ref>
ICWES IV - Cracow
Cracow, Poland (1975)
ICWES V - Rouen
The fifth International Conference of Women Engineers and Scientists was held 4–8 September 1978 in Rouen, France, under the auspices of the Cercle Des Femmes Ingenieurs, led by their President, Nicole Becarud. It was attended by over 200 delegates from 35 countries.
ICWES VI - Mumbai
Mumbai, India (1981)
ICWES VII - Washington DC
Washington DC, USA (1984)
ICWES VIII - Abidjan
Abidjan, Ivory Coast (1988)
ICWES IX - Warwick
Warwick, UK (1991)
ICWES X - Budapest
Budapest, Hungary (1996)
ICWES XI - Chiba
Chiba, Japan (1999);
ICWES XII - Ottawa
Ottawa, Canada (2002)
ICWES XIII - Seoul
Seoul, South Korea (2005)
ICWES XIV - Lille
Lille, France (2008)
ICWES XV - Adelaide
Adelaide, Australia (2011)
ICWES XVI - Los Angeles
Los Angeles, USA (2014)
ICWES XVII - New Delhi
ICWES17 was held on 5–7 October 2017 in New Delhi, India, hosted by WISE-India, with nearly 300 attendees from 18 countries and four continents.
ICWES XVIII - Coventry, UK
ICWES18 was held in Coventry in 2021.
ICWES XVIX - New Zealand
ICWES19 was held in 2023.
References
Women in engineering
International conferences
Engineering conferences
Science conferences
Women in science and technology
Women's conferences
1964 establishments | International Conference of Women Engineers and Scientists | [
"Technology"
] | 1,349 | [
"Women in science and technology"
] |
66,059,371 | https://en.wikipedia.org/wiki/Thomas%20Albrecht | Thomas Albrecht is an American radiochemist specializing in the chemistry and physics of transuranium elements. He is jointly appointed as a University Distinguished Professor at the Colorado School of Mines in Golden, Colorado, and Director of the Nuclear Science & Engineering Center and as a scientist at Idaho National Laboratory.
Education and career
Thomas Albrecht received his undergraduate education in chemistry at Southwest Minnesota State University, during which time he also performed research at Texas A&M with J. P. Fackler on gold chemistry and Ron Caple on organometallic chemistry at the University of Minnesota-Duluth via REU-NSF programs. He received his doctorate in inorganic chemistry in 1997 from Northwestern University under James Ibers where he studied the synthesis, structures, and reactivity of transition metal polychalcogenides. Following a postdoctoral position at the University of Illinois in 1998 with J. R. Shapley on metal-fullerene chemistry, he became an assistant professor at Auburn University later that year, transitioning to associate professor in 2002 and full professor in 2007. While at Auburn, he built a large program dedicated to understanding the chemistry and physics of f-block compounds. He opened the first new transuranium laboratory in decades in the U.S. while at Auburn, and continued this theme as the Frank M. Freimann Chair at the University of Notre Dame from 2009 to 2012. He moved to Florida State University in 2012 to become the first Gregory R. Choppin Chair in Chemistry. In 2022 he joined the faculty at the Colorado School of Mines in Golden, Colorado, and was a part of the inaugural group of University Distinguished Professors.
Research
Prof. Albrecht directs a research group at the Colorado School of Mines in radio- and nuclear chemistry as well as the chemistry and physics of critical materials. In 2016 he received federal funding from the U.S. Department of Energy through the Office of Basic Energy Sciences as part of the Energy Frontier Research Center program to establish the Center for Actinide Science & Technology (CAST), a multi-institution research center dedicated to advancing our understanding of how electronic structure and bonding control the properties of radioactive materials, with focus on alleviating the environmental impacts of nuclear power and the Cold War.
His research focuses on the use of synthetic, crystallographic, and spectroscopic techniques and quantum chemical simulation to better understand the nature of bonding and physical properties in lanthanides and actinides complexes. Prof. Albrecht is particularly known for his research on the chemistry of highly radioactive and scarce heavy actinides such as berkelium and californium.
Awards and honors
In 2019 Prof. Albrecht was awarded the Glenn T. Seaborg Award in Nuclear Chemistry for outstanding contributions to nuclear and radiochemistry at the American Chemical Society meeting in Orlando, Florida. The focus of this award was his group's discovery of a fundamental break in the chemistry of actinides that begins at californium. His group is responsible for the majority of transuranium single crystal structures and was the first to apply the use of microdiffraction techniques to compounds of these elements. His team was also the first to report the single crystal structure of a berkelium compound. He was in 2015 elected as a fellow of the Royal Society of Chemistry for contributions including his pioneering work on californium. In 2018, Prof. Albrecht was elected a fellow of the American Association for the Advancement of Science and was the preceptor for the ACS Nobel Signature Prize for Graduate Education in Chemistry. He has delivered a number of important endowed lectures throughout the world including the Gerhard and Lisolette Closs Memorial Lecture at the University of Chicago and the George Fischer Baker Lecture at Cornell University. In 2024, he was awarded the M. J. Buerger Award for contributions of exceptional distinction in areas of interest to the American Crystallographic Association.
Select publications
SH Cho, B Ma, SBT Nguyen, JT Hupp, TE Albrecht-Schmitt, A metal–organic framework material that functions as an enantioselective catalyst for olefin epoxidation (2006), Chemical communications, Issue 24, Pages 2563-2565
L Zhu, D Sheng, C Xu, X Dai, MA Silver, J Li, P Li, Y Wang, Y Wang, Identifying the Recognition Site for Selective Trapping of 99TcO4– in a Hydrolytically Stable and Radiation Resistant Cationic Metal–Organic Framework, (2017) Journal of the American Chemical Society
References
Radiochemistry
20th-century American chemists
Living people
Southwest Minnesota State University alumni
Northwestern University alumni
University of Notre Dame faculty
21st-century American chemists
Colorado School of Mines faculty
Florida State University faculty
Auburn University faculty
Fellows of the Royal Society of Chemistry
Fellows of the American Association for the Advancement of Science
1971 births | Thomas Albrecht | [
"Chemistry"
] | 972 | [
"Radioactivity",
"Radiochemistry"
] |
66,060,006 | https://en.wikipedia.org/wiki/Rystad%20Energy | Rystad Energy is an independent energy research and business intelligence company headquartered in Oslo, Norway. It is the biggest independent energy consultancy in Norway, and a world-leading analysis company for the energy sector. The company provides mainly oil and gas analyzes, but the share of renewable energy and carbon emission analyzes has increased continuously. Its main market is New York. In addition to oil, oil services and finance companies, its customers include institutions such as OPEC, the International Energy Agency, and the World Bank.
Rystad was founded in 2004 by Jarand Rystad, a Norwegian physicist and earlier consultancy partner for McKinsey. The company specializes in analysis of global energy issues, and has the sole comprehensive database for production data, engineering and financing of all oil and gas fields and deposits in the world. It also has developed similar databases for a wide range of segments within fossil and renewable energy production and related energy equipment and services sectors.
The company is owned by its founder and CEO Jarand Rystad with minority shares owned by senior staff of the company. Jarand Rystad is described by Financial Times as "one of the most cited petroleum analysts in the industry".
Rystad Energy is headquartered in Oslo and has global offices in Houston, Singapore, Dubai, Houston, New York, London, Aberdeen, Moscow, Istanbul, Rio de Janeiro, Singapore, Tokyo, Kuala Lumpur, Beijing, Bangalore, Stavanger, Sydney, and Perth.
In 2019, Rystad's revenue was 331 million Norwegian krone and operating profit was 8.3 million krone.
In April 2021, Rystad predicted that due to COVID-19 and energy transition oil demand will peak at in 2026.
It has also said that at least US$3 trillion investment into exploration and development of of new oil resources would be required to meet the oil demand in 2050.
References
Energy research institutes
Research and analysis firms
Energy consultancies
Norwegian companies established in 2004
Multinational companies headquartered in Norway | Rystad Energy | [
"Engineering"
] | 397 | [
"Energy research institutes",
"Energy organizations"
] |
66,060,622 | https://en.wikipedia.org/wiki/Tetsuo%20Nozoe | Tetsuo Nozoe (野副 鉄男, 16 May 1902 – 4 April 1996) was a Japanese organic chemist. He is known for the discovery of hinokitiol, a seven-membered aromatic compound, and studying non-benzenoid aromatic compounds.
Early life and career
Tetsuo Nozoe was born on 16 May 1902 in Sendai to Juichi Nozoe, a lawyer and one-time member of the National Diet, and Toyo Nozoe. Tetsuo's family was Buddhist except of his mother who was a devout Christian. Tetsuo had three sisters and seven brothers, and he was the sixth child in the family. He started doing chemical experiments at home since his junior high school days. Although his parents wanted him to become a medical doctor, and even sent him for premedical classes, he proceeded his education with chemistry. After graduating from high school in Sendai, he entered the Department of Chemistry at Tohoku Imperial University in 1920. In university, he studied organic chemistry under Riko Majima, a leading scientist in organic chemistry in Japan.
In 1926, after graduation he moved to Taihoku, Formosa, where he started working as a researcher at the Camphor Research Laboratories of the Monopoly Bureau and then at the Department of Chemical Industry of the Central Research Institute, both under Government-General of Taipei. In Formosa, Tetsuo was studying the structures of natural compounds, such as saponins, sapogins, sapogenins, triterpenoids and glycosides, especially in plants found locally. In 1937, with the help of ultraviolet–visible spectroscopy he predicted the correct structures for oleanolic acid and hederagenin, common sapogenins. In the same year he became a professor of chemistry at Taihoku Imperial University. The scope of his research in those times included also studying constituents of wool wax and those of other animal skin waxes. He discovered lanolinic acids and agnolinic acids, groups of unusual branched chain fatty acids.
One of the most popular works of Tesuo Nozoe was the research on the chemical constituents of taiwanhinoki (Chamaecyparis taiwanensis, Taiwan cypress), a coniferous tree native to Taiwan. The natural resistance of this and other tree species belonging to Cupressaceae family to fungal wood decay prompted Japanese researchers to study the chemical components of these trees. Nenokichi Hirao, a Japanese chemist, derived a dark-red pigment from hinoki oil and called hinokitin in 1926. Tetso's research led to discovery of a new series of chemical compounds, non-benzoniod aromatic compounds, including hinokitiol. He obtained hinokitiol from hinokitin, and showed that hinokitin is an iron complex of hinokitiol, (C10H11O2)3Fe. It was first published in 1936 in a special issue of the Bulletin of the Chemical Society of Japan. After three more years of work in Formosa following the World War II, Tetsuo returned to Japan. As a professor at Tohoku University, he continued his work on hinokitiol. Later in 1948, Holger Erdtman, a Scottish organic chemist, reported isolation of three isomeric monoterpenoids (α-, β-, and γ-thujaplicin) from Thuja plicata (Western red cedar) in his paper published in Nature. After correspondence, both Tetsuo and Holger found that hinokitiol is identical to β-thujaplicin and has a tropolone structure. Tetsuo Nozoe and Holger Erdtman became lifelong friends. In 1951, Nozoe got an opportunity to publish his work on hinokitiol and its derivatives in Nature. He also studied chemical characteristics of tropones, tropolones, other troponoids, and azulenes.
Personal life
Tetsuo Nozoe was married to Kyoko Horiuchi and had four children – one son and three daughters. Tetsuo died of cancer on 4 April 1996.
He was collecting autographs and tributes from famous chemists all over the world, including at least 32 Nobel laureates, and had collected more than 4,000 signatures and comments in his note books. Tetsuo's autograph books, of 1,179 pages, are kept in the archives in Tohoku University.
His son Shigeo, daughter Yoko, grandson and granddaughters also studied chemistry. Shigeo Nozoe was also a professor of chemistry at Tokohu University.
Awards and honors
Order of the Sacred Treasure, 6th class (1940)
Majima Award for Organic Chemistry of the Chemical Society of Japan (1944)
Order of the Sacred Treasure, 5th class (1944)
Order of the Sacred Treasure, 4th class (1945)
Asahi Prize (1952)
Japan Academy Award (1953)
Order of Culture (1958)
Person of Cultural Merit (1958)
Dark-blue Ribbon Medal and Imperial Cup of the Government of Japan (1967)
Order of the Sacred Treasure, 1st class (1972)
Cultural Medal of the Republic of China (1979)
August Wilhelm von Hofmann Memorial Medal of the German Chemical Society (1981)
Special Award of the Society of Synthetic Organic Chemistry of Japan (1984)
Honorary membership
Honorary Member, Chinese Chemical Society (1962)
Foreign Member, Royal Swedish Academy of Sciences (1972)
Honorary Member, Japan Pharmaceutical Association) (1973)
Honorary Member, Chemical Society of Japan (1977)
Honorary Member, Japan Society for Bioscience, Biotechnology, and Agrochemistry (1977)
Honorary Member, Swiss Chemical Society (1977)
Member, Japan Academy (1977)
Honorary Member, Society of Synthetic Organic Chemistry of Japan (1990)
Honorary citizenship
Honorary Citizen of Sendai (1959)
Honorary Citizen of Taipei (1983)
Selected bibliography
See also
Hinokitiol
Thujaplicin
Tohoku Imperial University
References
Further reading
External links
The Nozoe Autograph Books
野副鉄男 Tetsuo Nozoe | Chem-Station (ケムステ)
Japanese organic chemists
20th-century Japanese chemists
1902 births
1996 deaths
Members of the Royal Swedish Academy of Sciences | Tetsuo Nozoe | [
"Chemistry"
] | 1,288 | [
"Organic chemists",
"Japanese organic chemists"
] |
66,062,517 | https://en.wikipedia.org/wiki/Borate%20nitrate | Borate nitrates are mixed anion compounds containing separate borate and nitrate anions.
List
References
Nitrates
Borates
Mixed anion compounds | Borate nitrate | [
"Physics",
"Chemistry"
] | 30 | [
"Matter",
"Mixed anion compounds",
"Nitrates",
"Salts",
"Oxidizing agents",
"Ions"
] |
66,063,175 | https://en.wikipedia.org/wiki/HD%2049268 | HD 49268 (HR 2505) is a solitary star in the southern circumpolar constellation Volans. It has an apparent magnitude of +6.49, placing it near the limit of naked eye visibility. Parallax measurements place the object at a distance of 456 light years; it is receding with a heliocentric radial velocity of .
The stellar classification of HD 49268 is K1 III CNII, indicating that it is an ageing red giant with a strong over-abundance of cyano radical in its stellar atmosphere. It has 136% the mass of the Sun but expanded to 10.77 times its girth. It is radiating 60 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of , giving it an orange hue. HD 49268 is slightly metal enriched with an iron abundance 117% that of the Sun and is believed to be a member of the thick disk population. It spins leisurely with a projected rotational velocity that is lower than .
HD 49268 has two faint companions listed in the Washington Double Star Catalogue: a tenth magnitude star away; and a 13th magnitude star away. Both are unrelated background stars.
References
K-type giants
Volans
CD-71 00357
049268
031977
2505
Volantis, 2
CN stars | HD 49268 | [
"Astronomy"
] | 275 | [
"Volans",
"Constellations"
] |
66,063,366 | https://en.wikipedia.org/wiki/Epsilon%20Mensae | Epsilon Mensae, Latinized to ε Mensae, is a single star in the southern circumpolar constellation Mensa. It has an apparent magnitude of 5.52, making it faintly visible to the naked eye under ideal conditions. The object has a heliocentric radial velocity of , meaning it is receding from the Solar System, and is estimated to be 454 light years away.
Epsilon Mensae has a stellar classification of K2/3 III — intermediate between a K2 and K3 giant star. It has 115% the mass of the Sun and an enlarged radius of . It shines at 170 times the luminosity of the Sun from its photosphere at an effective temperature of , giving it an orange glow. Epsilon Mensae has a metallicity 49% that of the Sun and is believed to be a member of the young disk population. It spins leisurely with a projected rotational velocity of about .
References
Mensa (constellation)
Mensae, Epsilon
036039
2919
060816
K-type giants
Mensae, 43
PD-78 265 | Epsilon Mensae | [
"Astronomy"
] | 227 | [
"Mensa (constellation)",
"Constellations"
] |
66,063,501 | https://en.wikipedia.org/wiki/WASP-52 | WASP-52 is a K-type main-sequence star about 570 light-years away. It is older than the Sun at billion years, but it has a similar fraction of heavy elements.
The star has prominent starspot activity, with 3% to 14% of the stellar surface covered by areas 575 K cooler than the rest of the photosphere.
A multiplicity survey in 2015 did not detect any stellar companions. The star was named Anadolu in 2019 by Turkish astronomers as part of the NameExoWorlds contest.
Planetary system
In 2012 a transiting hot Jupiter planet, WASP-52b, was detected in a tight, circular orbit. The planet was named Göktürk by Turkish astronomers in December 2019. The planet has a small measured temperature difference between dayside (1481 K) and nightside (1224 K). Planetary orbit is well aligned with the equatorial plane of the star, the misalignment being 5.47°.
Search for transit timing variation did not result in detection of additional planets in system as in 2021.
A transmission spectrum taken in 2020 has revealed the presence of hydrogen, sodium and potassium, although the sodium and potassium lines may be attributable to volcanically active moons of the gas giant, not the planet itself. The atmosphere has no high winds and relatively low-lying clouds, indicating it is not significantly enriched by heavy elements. No signs of the planetary atmosphere escaping to space were detected in 2020, but updated measurement in 2022 showed signs of helium escape, consistent with mass loss rate of 0.5% per billion years.
References
Pegasus (constellation)
K-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
J23135873+0845405
Anadolu | WASP-52 | [
"Astronomy"
] | 362 | [
"Pegasus (constellation)",
"Constellations"
] |
51,893,358 | https://en.wikipedia.org/wiki/List%20of%20internet%20service%20providers%20in%20Canada | This is an alphabetical list of notable internet service providers in Canada.
Among Canada's biggest internet service providers (ISP) are Bell, Rogers, Telus, and Shaw—with the former two being the largest in Ontario, and the latter two dominating western provinces.
List
Former ISPs
Craig Wireless
Internex Online
Look Communications
Mountain Cablevision
Persona Communications — acquired by Eastlink
Rush Communications Ltd.
See also
Internet in Canada
Telecommunications in Canada
List of companies of Canada
References
Internet
Internet service providers in Canada | List of internet service providers in Canada | [
"Technology"
] | 102 | [
"Computing-related lists",
"Internet-related lists"
] |
51,893,792 | https://en.wikipedia.org/wiki/Bierrum | Bierrum is a British civil engineering and construction company, that has built all of Britain's concrete cooling towers at the country's power stations since 1965.
History
Bierrum was founded by Hans Bierrum (or Hans Bjerrum), a Danish civil engineer that was born in Hellerup and had competed in the 1920 Summer Olympics in Belgium. Upon its establishment on 26 September 1927, the company was based at Victoria Street in London. Its first contract was at the former Shoreham Power Station; the first cooling tower was built in 1931. Bierrum became a limited company in 1938, and relocated to Harrow, then Sudbury Hill. Bierrum and Partners Ltd (00339806) was founded on 30 April 1938.
Hans Bjerrum passed away during 1979. Five years earlier, Hans' son, Roger, had been appointed as chairman of Bierrum. During 1991, the company acquired rival firm Pendrich out of receivership, rescuing 30 jobs in the process.
Throughout the 1990s and early 2000s, Bierrum introduced numerous means of improving safety for working at heights, including the Spider platform for the demolition of tall chimneys.
In September 2003, the company ran out of money, its fiscal circumstances having been troubled by a downturn in the power sector, legal action, and difficulties related to a project in Turkey. One year later, it was reformed as Bierrum International, through employees Gary Eastman and Bob Sutton. It became part of Beroa Technology Group GmbH (BTG) of Ratingen-Lintorf, North Rhine-Westphalia, Germany.
Presently, the company is named Dominion Bierrum and has been owned by Global Dominion Access of Bilbao since 2014, which was owned by CIE Automotive.
Structure
From January 1957, the company was headquartered at 167 Imperial Drive in Rayners Lane, an office building which it built for its own use. The company depot was at Smallford in Hertfordshire.
In 1981, Bierrum was based at Barwythe Hall at Studham near Dunstable.
It is headquartered in Central Bedfordshire, around one mile east of the M1, close to the Greensand Ridge Walk.
Projects
Bierrum has designed and built cooling towers (køletårn in Danish) and chimneys nationally and internationally. The firm demolishes chimneys incrementally using its Bierrum Rig.
Bierrum also built cement works, such as Ketton Cement Works in 1961, water towers, such as at North Walsham in 1954, and oil refinery chimneys.
In 1972, the firm built the 850 ft chimney of Grain Power Station, the tallest freestanding structure in South East England, completed in March 1975, requiring 38,100 tonnes of reinforcing steel and concrete.
Spinnaker Tower in Portsmouth, built by slip forming and climbing formwork (jumpform); the company ran out of money during construction in September 2003.
In 2016, it removed and rebuilt the iconic four chimneys of Battersea Power Station, in conjunction with contractor Skanska, and consultant engineer Buro Happold
Incidents
On the afternoon of Saturday 16 November 1958, 34 year old Edward Charles Burgess, of Goldenhill Rd in Fenton, fell 60 ft at Drakelow Power Station, and died on the morning of Sunday 17 November at Burton General Hospital
When building the Associated Portland Cement works at Westbury, Wiltshire in 1962, 22 year old steel erector, Winston Toms, fell 85 ft to his death
In April 1968, 55 year old Roman Mitchell, of Windsmoor St in Stoke, fell 40 ft to his death on the Rugeley B Power Station cooling tower number 8
See also
J. L. Eve Construction, built other UK electricity transmission infrastructure
Denmark–United Kingdom relations
Arup Group
Institute of Demolition Engineers, based in Kent
:Category:Construction and civil engineering companies of Denmark
References
External links
Science Museum
British companies established in 1938
Central Bedfordshire District
Chimneys in the United Kingdom
Companies based in Bedfordshire
Companies based in the London Borough of Harrow
Construction and civil engineering companies of the United Kingdom
Cooling towers
Demolition
Denmark–United Kingdom relations
1938 establishments in England
Construction and civil engineering companies established in 1938 | Bierrum | [
"Engineering"
] | 834 | [
"Construction",
"Demolition"
] |
51,893,947 | https://en.wikipedia.org/wiki/WR%20137 | WR 137 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus.
WR 137, together with WR 134 and WR 135, was one of three stars in Cygnus observed in 1867 to have unusual spectra consisting of intense emission lines rather than the more normal continuum and absorption lines. These were the first members of the class of stars that came to be called Wolf-Rayet stars (WR stars) after Charles Wolf and Georges Rayet who discovered their unusual appearance. It is a member of the carbon sequence of WR stars, indicated by the lack of nitrogen lines and the strength of carbon emission. WR 137 has a spectrum with CIII emission weaker than CIV and OV weaker still, leading to the assignment of a WC7 spectral type. The spectrum also shows emission lines of HeII and OIV.
WR 137 is a binary system, with an O9 main sequence or giant companion. The two stars orbit every thirteen years in a mildly eccentric orbit, and there is an episode of dust production near periastron. The inclination of the orbit is uncertain, most likely near 67° but with some analyses suggesting values around 23°. The O star is visually brighter and more massive, but the WR star dominates the spectrum and has a higher bolometric luminosity. Visible in the spectrum are absorption lines and some narrow emission lines, each thought to originate from the secondary star. The line profiles suggest a decretion disc around the star, produced by its rapid rotation, which would make it the only known system containing a WR star and an Oe star.
WR 137 is about a degree away from WR 135 and the two are believed to lie at approximately the same distance from Earth within the Cygnus OB3 association. Its properties are uncertain because of the presence of the hot luminous companion. A pseudo-fit of the combined spectrum yielded a temperature of 56,000 K, a luminosity of , and a radius of . A more typical radius for a WC7 star would be , implying a hotter temperature.
Evolutionary modelling of the WR 137 pair suggest an initial mass for the primary of and for the secondary of , with an age of 4.1 million years. The initial orbital period would have been around 1,580 days. Around have been transferred from the primary to the secondary.
References
External links
Wolf-Rayet shells showing a spectrum of WR 135
WR134 Ring Nebula with WR 135 visible in the top left corner
Cygnus (constellation)
Wolf–Rayet stars
Cygni, V1679
099769
192641
Durchmusterung objects
Spectroscopic binaries
O-type main-sequence stars | WR 137 | [
"Astronomy"
] | 550 | [
"Cygnus (constellation)",
"Constellations"
] |
51,897,188 | https://en.wikipedia.org/wiki/Roivant%20Sciences | Roivant Sciences Ltd. is an American multinational healthcare company focused on applying technology to drug development and building subsidiary life sciences and health technology companies. It was founded in 2014 by Vivek Ramaswamy and is currently headed by CEO Matt Gline. Roivant maintains its headquarters in New York City as well as major offices in the biotech hubs of Boston and Basel.
History
Vivek Ramaswamy founded Roivant in 2014. Ramaswamy's initial strategy was to in-license drug candidates and create subsidiaries focused on distinct therapeutic areas. This strategy expanded to include developing earlier stage drug candidates and platform technologies. Roivant is a parent company to over a dozen subsidiaries ranging from Immunovant, a majority-owned public company focused on autoimmune diseases, to privately held Dermavant Sciences, a commercial-stage company focused on medical dermatology.
Roivant also develops healthcare technologies through its business unit Roivant Health. Roivant built and launched Datavant, which allows healthcare institutions to share data, and was merged with Coix to become a US$7 billion company. Roivant's technology portfolio also includes Lokavant, which integrates clinical trial data to identify and mitigate risks in pharmaceutical development. In 2017, Roivant partnered with the private equity arm of Chinese state-owned CITIC Group to form Sinovant. As of 2019, Roivant had over 40 investigational drugs in development in 14 therapeutic areas across its family of companies.
At the end of 2019, Roivant formed a $3 billion partnership with Sumitomo Dainippon Pharma and transferred its ownership stake in five of its subsidiaries: Myovant Sciences, Urovant Sciences, Enzyvant Therapeutics, Altavant Sciences, and Spirovant Sciences, which now sit under Sumitovant Biopharma. The deal included the option for Sumitomo to acquire up to six additional subsidiaries.
In April 2020, Roivant dosed the first patient in a clinical study evaluating gimsilumab in COVID-19 patients for the prevention and treatment of acute respiratory distress syndrome (ARDS). Additionally, in April, Datavant announced that its technology is being used to create a pro bono COVID-19 research database to help public health and policy researchers combat the pandemic.
In January 2021, Ramaswamy stepped down as CEO. Matt Gline, previously the company's chief financial officer, became CEO. In February 2021, Roivant acquired Silicon Therapeutics, a small-molecule drug designer and computational physics platform, for $450 million in Roivant equity. In October 2021, Roivant merged with special-purpose acquisition company Montes Archimedes Acquisition Corp. to become listed on the Nasdaq.
In June 2022, Roivant and Pfizer unveiled Priovant Therapeutics. Priovant was established in September 2021 through a transaction between Roivant and Pfizer, in which Pfizer licensed oral and topical brepocitinib's global development rights and US and Japan commercial rights to Priovant. Pfizer holds a 25% equity ownership interest in Priovant. Brepocitinib is a potential first-in-class dual, selective inhibitor of TYK2 and JAK1; in all five placebo-controlled studies completed to date, oral brepocitinib generated statistically significant and clinically meaningful results. Later that year in December 2022, Roivant and Pfizer announced their third partnership to create a new Vant focused on developing TL1A drug candidates for inflammatory and fibrotic diseases. As of February 2023, Roivant's reported market cap was over $6 billion.
Axovant, owned by Roivant's Sio Gene Therapies, which failed testing in the end, has been accused of being a pump-and-dump scheme.
In December 2023, Roche completed the acquisition of Telavant from Roivant for a purchase price of $7.1 billion upfront and a near-term milestone payment of $150 million.
Subsidiaries and former subsidiaries
As of April 2020, the company's subsidiaries include:
Affivant
Covant
Datavant
Genevant, created to work on RNA-based therapeutics
Hemovant
Immunovant, launched in July 2018 to develop therapies for autoimmune diseases, with lead candidate IMVT-1401 being developed for the treatment of myasthenia gravis, Graves' ophthalmopathy and warm antibody autoimmune hemolytic anemia
Kinevant, a clinical-stage biopharmaceutical company developing new medicines for rare autoimmune and inflammatory diseases
Lokavant, which is focused on improving clinical trial monitoring
Priovant
Psivant
The following subsidiaries were previously a part of Roivant, but were included as part of a strategic transaction with Sumitomo Dainippon Pharma which closed in December 2019:
Altavant Sciences, which is developing a treatment for pulmonary arterial hypertension
Dermavant, focused on developing therapeutics in medical dermatology, with lead candidate tapinarof in development for the treatment of psoriasis and atopic dermatitis Organon & Co. agreed to acquire Dermavant in a deal worth up to $1.2 billion, including a $175 million upfront payment.
Enzyvant Therapeutics, which is focused on developing therapies for rare enzyme deficiencies
Myovant Sciences, founded in partnership with Takeda Pharmaceutical Company to develop medicines for women's health and prostate cancer
Spirovant, which focused on developing gene therapies for cystic fibrosis.
Urovant, which is developing lead candidate vibegron, licensed from Merck & Co.
Roivant is a major shareholder of Datavant, which was co-founded with Travis May to link disparate healthcare datasets. In October 2020, Datavant announced it raised funds from Roivant alongside Transformation Capital, Johnson & Johnson, and Cigna.
In June 2018, Roivant laid off 67 employees and reassigned 130 to subsidiaries.
In March 2020, Roivant announced it is developing gimsilumab, an anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF) monoclonal antibody to prevent and treat acute respiratory distress syndrome (ARDS) in patients with COVID-19. In April 2020, Roivant started the administration of gimsilumab to COVID-19 patients in the United States.
Funding
The company received millions of dollars from hedge funds such as QVT in the early days of its existence. Later, it was able to raise US$200 million, with help from NovaQuest Capital Management.
Notes
References
External links
Companies listed on the Nasdaq
Pharmaceutical companies established in 2014
Life sciences industry
Multinational companies
Special-purpose acquisition companies | Roivant Sciences | [
"Biology"
] | 1,409 | [
"Life sciences industry"
] |
51,898,110 | https://en.wikipedia.org/wiki/Homological%20stability | In mathematics, homological stability is any of a number of theorems asserting that the group homology of a series of groups is stable, i.e.,
is independent of n when n is large enough (depending on i). The smallest n such that the maps is an isomorphism is referred to as the stable range.
The concept of homological stability was pioneered by Daniel Quillen whose proof technique has been adapted in various situations.
Examples
Examples of such groups include the following:
Applications
In some cases, the homology of the group
can be computed by other means or is related to other data. For example, the Barratt–Priddy theorem relates the homology of the infinite symmetric group agrees with mapping spaces of spheres. This can also be stated as a relation between the plus construction of and the sphere spectrum. In a similar vein, the homology of is related, via the +-construction, to the algebraic K-theory of R.
References
Algebraic topology
Algebraic K-theory | Homological stability | [
"Mathematics"
] | 202 | [
"Fields of abstract algebra",
"Topology",
"Algebraic topology"
] |
51,898,340 | https://en.wikipedia.org/wiki/Technical%20Construction%20Archive%20%28Albania%29 | The Central Technical Construction Archive (AQTN) was established on July 26, 1993 in Tirana, Albania. It gathered technical construction projects of former institutes (ISP, N.GJ.GJ, ISPUK, ISPUN, ISPU) which belonged to Albania's former Ministry of Construction fund, materials from the Municipality of Tirana and KRRTSH decisions. AQTN's documentary archive has over 45,000 files and 556,000 pages, with the first document dating back to 1911 "Reconstruction of Buna Bridge". The main task of the archive is to preserve, maintain and manage the technical documentation in the field of construction to meet the requirements of private and public entities for technical documentation at its disposal.
See also
List of archives in Albania
References
Archives in Albania
1993 establishments in Albania
Architecture in Albania
Construction standards
Technical communication
Government agencies established in 1993
Business and industry archives | Technical Construction Archive (Albania) | [
"Engineering"
] | 186 | [
"Construction",
"Construction standards"
] |
51,898,884 | https://en.wikipedia.org/wiki/Fear%20of%20trains | The fear of trains is anxiety and fear associated with trains, railways, and railway travel.
Psychoanalysis
Psychonalysts, starting from Sigmund Freud, associated sensations towards travel by train with sexuality. In 1906, Freud wrote that the link between railway travel and sexuality derives from the pleasurable sensation of shaking during the travel. Therefore, in the event of repression of sexuality the person will experience anxiety when confronted with railway travel. Karl Abraham interpreted the fear of the uncontrollable motion of a train as a projection of the fear of uncontrolled sexuality. Wilhelm Stekel (1908) also associated train phobia with rocking sensation, but in addition to libido repression, he associated it with the embarrassment with the reminiscences of the rocking sensation of the early childhood.
Other considerations
Freud himself was suffering a kind of train anxiety, as he confessed in a number of letters. He used the term "Reiseangst" for it, which literally means "fear of travel" but it was recognized it was primarily associated with the travel by train, and some translators translated Freud's "Reiseangst" as "railroad phobia" However Freud's anxiety was not classified as a "true" phobia, since once the travel started, the anxiety disappeared, and in fact, Freud traveled much and liked it.
Regardless of sexuality, since early days various authors associated the uncontrollable movement of the train with the fear of derailment, or a catastrophe.
Another source of fear in the early days of railway travel was travelers' isolation from the outside world, as well as the confinement in a small compartment, rendering a person who became sick or subject to crime, helpless. "...The loudest screams are swallowed up by the roar of the rapidly revolving wheels...". This kind of fear, as well as actual crimes committed in trains, were often a matter of newspaper publications of the times. After a number of prominent cases this fear was elevated to the level of collective psychosis. Public fear about rail travel was heightened after British surgeon John Eric Erichsen described a post-traumatic diagnosis known as railway spine or "Erichsen's disease". People diagnosed with this had no obvious injury and were rejected as fake. Nowadays it is known that traffic accidents may cause post-traumatic stress disorder.
Alternative names and etymology
It has been variously called "train phobia", "railroad phobia", "dread of railway travel", etc. The German term "Eisenbahnangst" used, e.g., by Sigmund Freud was literally converted into Greek as "siderodromophobia" (Eisen = sideron = iron, Bahn = dromos = way, Angst = phobos = fear). In cases when this anxiety exceeds the social norms of a realistic fear, this anxiety may be classified as a specific phobia about trains. Campbell's Psychiatric Dictionary puts the fear of trains under the "vehicle phobia", together with fears of boats, airplanes, automobiles, and other forms of transportation.
Cultural references
A 1913 short story Terror by Jun'ichirō Tanizaki is a first-person narrative of a young man suffering of the morbid fear of travel in trains and streetcars. Tanizaki uses the German word Eisenbahnkrankheit, "railroad sickness".
See also
Other travel-related anxieties include:
Fear of air travel
Fear of sea travel
Driving phobia
Other transport-related disorders include:
Transport tetany in animals, also known as "railroad disease" or "railroad sickness"
Travel sickness in humans; in the late 1800s a "railroad sickness" (:de:Eisenbahnkrankheit) was frequently diagnosed
References
External links
The Victorian Belief That a Train Ride Could Cause Instant Insanity - Atlas Obscura
Early Trains Were Thought to Make Women's Uteruses Fly Out | Mental Floss
Phobias
Freudian psychology
Trains | Fear of trains | [
"Technology"
] | 821 | [
"Trains",
"Transport systems"
] |
51,899,244 | https://en.wikipedia.org/wiki/Kumeyaay%20astronomy | Kumeyaay astronomy or cosmology (Kumeyaay: My Uuyow, "sky knowledge") comprises the astronomical knowledge of the Kumeyaay people, a Native American group whose traditional homeland occupies what is now Southern California in the United States and adjacent parts of northern Baja California in Mexico. A deeply rooted cosmological belief system was developed and followed by the Kumeyaay civilization based on this knowledge including the computing of time (Kumeyaay Mat’taam).
The first evidence of astronomical observations and visual registration was discovered in the El Vallecito archeological zone. The "Men in a square" rupestric painting located at El Diablito area of El Vallecito depicted a square that aligns with sunlight on the Fall equinox. These paintings were made by the Kumeyaay people, possibly during nomadic travels. Kumeyaay sand paintings and rock art modeled the passage of the sun, moon, and constellations.
Observation areas were made by the Kumeyaay to watch and register astronomical events. However many were destroyed by vandals before protection measures were instituted.
Astronomical objects
Hatotkeur (Spine of the Sky) - Milky Way
Constellations:
See also
Cultural astronomy
References
External links
San Diego Museum of Man
Astronomy-related lists
History of astronomy
Kumeyaay
Archaeoastronomy | Kumeyaay astronomy | [
"Astronomy"
] | 280 | [
"Astronomy-related lists",
"Archaeoastronomy",
"Astronomical sub-disciplines",
"History of astronomy"
] |
51,902,843 | https://en.wikipedia.org/wiki/Population%20health%20policies%20and%20interventions | Population health, a field which focuses on the improvement of the health outcomes for a group of individuals, has been described as consisting of three components: "health outcomes, patterns of health determinants, and policies and interventions". Policies and Interventions define the methods in which health outcomes and patterns of health determinants are implemented. Policies which are helpful "improve the conditions under which people live". Interventions encourage healthy behaviors for individuals or populations through "program elements or strategies designed to produce behavior changes or improve health status".
Policies and interventions are needed due to the inequalities amongst populations and the inconsistent way care is administered. Policies can include "necessary community and personal social and health services" as well as taxes on alcohol and soft drinks and implement smoking cessation policies. Interventions can include therapeutic or preventative health care and may also include actions taken by the individual or by someone on behalf of the individual. The application of population health is determined by the policies and interventions which can be implemented within an organization, city, state or country.
Common methodology
Countries, states, provinces and providers across the globe are shifting towards better systems to respond to inconsistent health outcomes, mitigate decreasing margins and replace outdated methods such as fee-for-service health delivery. Payment model reforms, including the Accountable Care Organization (ACO), provide roadmaps for healthcare reform and drive many of its constituents towards more effective and innovative means for improving health outcomes. Population health management is a common approach for resolving these challenges but it involves new methods, tools, systems and implementations to correct inefficiencies and improve health outcomes.
Population health tools and computer systems include data exchange, large datasets, and advanced software which are used to supply data scientists and research teams with appropriate information which can then be used by policy makers and change agents. This method helps to set policies around population health as well as intervention strategies which are then used to respond to the needs of a population.
Policies and policymakers
Policy for population health "sets priorities" and are a "guide to action to change what would otherwise occur". Policies are based on "social sciences of sociology, economics, demography, public health, anthropology, and epidemiology" and determine how outcomes can be accomplished are implemented at various levels. Such guides determine laws, policies, and ordinances and are defined by policymakers. Examples of policies include "smoking bans, excise taxes on cigarettes and alcohol, seat belt laws, water fluoridation, and restaurant menu labeling". They may be applied to a commercial establishment such as a restaurant, business workplace or within a city or state level. Policies should be evidence based and require academic studies or research to support the approach. This will assure that the appropriate measures needed for each demographic are promoted to encourage the necessary intervention practices which can be applied to each population or to the nation as a whole.
Policymakers can be classified as both private and public and are defined as someone who is in a position of authority to implement health policies. A public policy maker could be a government official and a private policymaker could be a business owner or administrator. Policymakers are influenced by, and can also be, change agents. Change agents include "legislators in Washington, an attorney general, regulators at the FDA, an advocacy group or other organizations that clearly have influence".
Political strategy
The goal for any political strategies surrounding population health is to "improve chances of success for policy adoption and implementation". Such strategies include the creation of funds to support initiatives and the construction of strategies which limit conflicts of interest in the implementation of public policy.
Tobacco control
A political strategy implemented to limit the sale and exposure to tobacco products and restrict the tobacco company's ability to benefit politically from charitable donations is the creation of the World Health Framework Convention on Tobacco Control (FCTC) treaty. The legally binding document is supported by numerous countries, government/nongovernment agencies and provides the necessary power to prevent negative influences on population health policies.
Interventions
Interventions in population health "shift the distribution of health risk by addressing the underlying social, economic and environmental conditions" and are implemented through "programs or policies designed and developed in the health sector, but they are more likely to be in sectors elsewhere, such as education, housing or employment". They are aimed at reducing such things as childhood obesity, cardiovascular disease, smoking and mental health issues throughout society. The means in which interventions are devised is through extensive research and contributions from medical scientists, researchers, and medical professionals. They are implemented by but are not limited to educators, practicing physicians, business administrators and mental health professionals.
Approaches and implementations
A typical approach includes assessing the conditions and possible improvements which can be made within the social determinants that have been identified. Each approach is handled at a state or health plan level.
One example was a workplace in China which implemented policies and interventions for their staff to fight depression. By recognizing the importance of mental health, they were able to reduce depression and improve job satisfaction across the company. The company published its research and findings to promote "enterprises taking more responsibility for the provision of mental health services to their employees".
Another example was the implementation of a smoking cessation program to the province of Ontario. Studies were performed on weekly visit rates to psychiatric emergency departments before and after the implementation. The result was a "15.5% reduction in patient visits for patients with a primary diagnosis of psychotic disorder".
Inequalities and variance of implementation
As is the common understanding of population health, health inequalities, defined as a "generic term used to designate differences, variations, and disparities in the health achievements of individuals and groups", must be considered to correctly implement the most effective policies and interventions. Based on a population and its socioeconomic, geographic, ethnicity and other factors, policies and interventions may vary. Policies implemented for one population may be less effective and more costly than it would be for another similar population. For example, US policies tend to be more costly than European and have less impact. Research has shown that in some instances, "Americans had worse outcomes than their international peers" and also had "the lowest life expectancy at birth of the countries studied".
See also
Population health
Community health
Economic inequality
Health disparities
Health impact assessment
Inequality in disease
List of countries by income equality
Social determinants of health
Sin tax
Sugary drinks tax
WHO Framework Convention on Tobacco Control (FCTC)
References
Further reading
Agafonow, Alejandro (2018). Setting the bar of social enterprise research high. Learning from medical science, Social Science & Medicine Vol 214, October, Pages 49–56, DOI: 10.1016/j.socscimed.2018.08.020
External links
http://www.improvingpopulationhealth.org/blog/policies-and-programs.html
Demography
Global health
Health economics
Social classes | Population health policies and interventions | [
"Environmental_science"
] | 1,394 | [
"Demography",
"Environmental social science"
] |
51,902,988 | https://en.wikipedia.org/wiki/Coverage%20%28genetics%29 | In genetics, coverage is one of several measures of the depth or completeness of DNA sequencing, and is more specifically expressed in any of the following terms:
Sequence coverage (or depth) is the number of unique reads that include a given nucleotide in the reconstructed sequence. Deep sequencing refers to the general concept of aiming for high number of unique reads of each region of a sequence.
Physical coverage, the cumulative length of reads or read pairs expressed as a multiple of genome size.
Genomic coverage, the percentage of all base pairs or loci of the genome covered by sequencing.
Sequence coverage
Rationale
Even though the sequencing accuracy for each individual nucleotide is very high, the very large number of nucleotides in the genome means that if an individual genome is only sequenced once, there will be a significant number of sequencing errors. Furthermore, many positions in a genome contain rare single-nucleotide polymorphisms (SNPs). Hence to distinguish between sequencing errors and true SNPs, it is necessary to increase the sequencing accuracy even further by sequencing individual genomes a large number of times.
Ultra-deep sequencing
The term "ultra-deep" can sometimes also refer to higher coverage (>100-fold), which allows for detection of sequence variants in mixed populations. In the extreme, error-corrected sequencing approaches such as Maximum-Depth Sequencing can make it so that coverage of a given region approaches the throughput of a sequencing machine, allowing coverages of >10^8.
Transcriptome sequencing
Deep sequencing of transcriptomes, also known as RNA-Seq, provides both the sequence and frequency of RNA molecules that are present at any particular time in a specific cell type, tissue or organ. Counting the number of mRNAs that are encoded by individual genes provides an indicator of protein-coding potential, a major contributor to phenotype. Improving methods for RNA sequencing is an active area of research both in terms of experimental and computational methods.
Calculation
The average coverage for a whole genome can be calculated from the length of the original genome (G), the number of reads (N), and the average read length (L) as . For example, a hypothetical genome with 2,000 base pairs reconstructed from 8 reads with an average length of 500 nucleotides will have 2× redundancy. This parameter also enables one to estimate other quantities, such as the percentage of the genome covered by reads (sometimes also called breadth of coverage). A high coverage in shotgun sequencing is desired because it can overcome errors in base calling and assembly. The subject of DNA sequencing theory addresses the relationships of such quantities.
Physical coverage
Sometimes a distinction is made between sequence coverage and physical coverage. Where sequence coverage is the average number of times a base is read, physical coverage is the average number of times a base is read or spanned by mate paired reads.
Genomic coverage
In terms of genomic coverage and accuracy, whole genome sequencing can broadly be classified into either of the following:
A draft sequence, covering approximately 90% of the genome at approximately 99.9% accuracy
A finished sequence, covering more than 95% of the genome at approximately 99.99% accuracy
Producing a truly high-quality finished sequence by this definition is very expensive. Thus, most human "whole genome sequencing" results are draft sequences (sometimes above and sometimes below the accuracy defined above).
References
Molecular biology
DNA sequencing | Coverage (genetics) | [
"Chemistry",
"Biology"
] | 688 | [
"Biochemistry",
"Molecular biology techniques",
"DNA sequencing",
"Molecular biology"
] |
51,903,429 | https://en.wikipedia.org/wiki/NGC%20269 | NGC 269 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on November 5, 1836 by John Herschel.
References
External links
0269
Open clusters
Small Magellanic Cloud
Tucana | NGC 269 | [
"Astronomy"
] | 53 | [
"Tucana",
"Constellations"
] |
51,903,451 | https://en.wikipedia.org/wiki/NGC%20270 | NGC 270 is a lenticular galaxy in the constellation Cetus. It was discovered on December 10, 1798 by William Herschel.
References
External links
0270
Lenticular galaxies
Cetus
002938
Discoveries by William Herschel
-02-03-027 | NGC 270 | [
"Astronomy"
] | 53 | [
"Cetus",
"Constellations"
] |
51,903,477 | https://en.wikipedia.org/wiki/NGC%20271 | NGC 271 is a barred spiral galaxy in the constellation Cetus. It was discovered on October 1, 1785 by William Herschel.
References
External links
0271
17851001
Cetus
Barred spiral galaxies
002949
Discoveries by William Herschel
+00-03-012 | NGC 271 | [
"Astronomy"
] | 57 | [
"Cetus",
"Constellations"
] |
51,905,555 | https://en.wikipedia.org/wiki/ProbOnto | ProbOnto is a knowledge base and ontology of probability distributions. ProbOnto 2.5 (released on January 16, 2017) contains over 150 uni- and multivariate distributions and alternative parameterizations, more than 220 relationships and re-parameterization formulas, supporting also the encoding of empirical and univariate mixture distributions.
Introduction
ProbOnto was initially designed to facilitate the encoding of nonlinear-mixed effect models and their annotation in Pharmacometrics Markup Language (PharmML) developed by DDMoRe, an Innovative Medicines Initiative project. However, ProbOnto, due to its generic structure can be applied in other platforms and modeling tools for encoding and annotation of diverse models applicable to discrete (e.g. count, categorical and time-to-event) and continuous data.
Knowledge base
The knowledge base stores for each distribution:
Probability density or mass functions and where available cumulative distribution, hazard and survival functions.
Related quantities such as mean, median, mode and variance.
Parameter and support/range definitions and distribution type.
LaTeX and R code for mathematical functions.
Model definition and references.
Relationships
ProbOnto stores in Version 2.5 over 220 relationships between univariate distributions with re-parameterizations as a special case, see figure. While this form of relationships is often neglected in literature, and the authors concentrate one a particular form for each distribution, they are crucial from the interoperability point of view. ProbOnto focuses on this aspect and features more than 15 distributions with alternative parameterizations.
Alternative parameterizations
Many distributions are defined with mathematically equivalent but algebraically different formulas. This leads to issues when exchanging models between software tools. The following examples illustrate that.
Normal distribution
Normal distribution can be defined in at least three ways
Normal1(μ,σ) with mean, μ, and standard deviation, σ
Normal2(μ,υ) with mean, μ, and variance, υ = σ^2 or
Normal3(μ,τ) with mean, μ, and precision, τ = 1/υ = 1/σ^2.
Re-parameterization formulas
The following formulas can be used to re-calculate the three different forms of the normal distribution (we use abbreviations i.e. instead of etc.)
Log-normal distribution
In the case of the log-normal distribution there are more options. This is due to the fact that it can be parameterized in terms of parameters on the natural and log scale, see figure.
The available forms in ProbOnto 2.0 are
LogNormal1(μ,σ) with mean, μ, and standard deviation, σ, both on the log-scale
LogNormal2(μ,υ) with mean, μ, and variance, υ, both on the log-scale
LogNormal3(m,σ) with median, m, on the natural scale and standard deviation, σ, on the log-scale
LogNormal4(m,cv) with median, m, and coefficient of variation, cv, both on the natural scale
LogNormal5(μ,τ) with mean, μ, and precision, τ, both on the log-scale
LogNormal6(m,σg) with median, m, and geometric standard deviation, σg, both on the natural scale
LogNormal7(μN,σN) with mean, μN, and standard deviation, σN, both on the natural scale
ProbOnto knowledge base stores such re-parameterization formulas to allow for a correct translation of models between tools.
Examples for re-parameterization
Consider the situation when one would like to run a model using two different optimal design tools, e.g. PFIM and PopED. The former supports the LN2, the latter LN7 parameterization, respectively. Therefore, the re-parameterization is required, otherwise the two tools would produce different results.
For the transition following formulas hold
.
For the transition following formulas hold
.
All remaining re-parameterisation formulas can be found in the specification document on the project website.
Ontology
The knowledge base is built from a simple ontological model. At its core, a probability distribution is an instance of the class thereof, a specialization of the class of mathematical objects. A distribution relates to a number of other individuals, which are instances of various categories in the ontology. For example, these are parameters and related functions associated with a given probability distribution. This strategy allows for the rich representation of attributes and relationships between domain objects. The ontology can be seen as a conceptual schema in the domain of mathematics and has been implemented as a PowerLoom knowledge base. An OWL version is generated programmatically using the Jena API.
Output for ProbOnto are provided as supplementary materials and published on or linked from the probonto.org website. The OWL version of ProbOnto is available via Ontology Lookup Service (OLS) to facilitate simple searching and visualization of the content. In addition the OLS API provides methods to programmatically access ProbOnto and to integrate it into applications. ProbOnto is also registered on the BioSharing portal.
ProbOnto in PharmML
A PharmML interface is provided in form of a generic XML schema for the definition of the distributions and their parameters. Defining functions, such as probability density function (PDF), probability mass function (PMF), hazard function (HF) and survival function (SF), can be accessed via methods provided in the PharmML schema.
Use example
This example shows how the zero-inflated Poisson distribution is encoded by using its codename and declaring that of its parameters (‘rate’ and ‘probabilityOfZero’). Model parameters Lambda and P0 are assigned to the parameter code names.
<Distribution>
<po:ProbOnto name="ZeroInflatedPoisson1">
<po:Parameter name="rate">
<ct:Assign>
<ct:SymbRef symbIdRef="Lambda" />
</ct:Assign>
</po:Parameter>
<po:Parameter name="probabilityOfZero">
<ct:Assign>
<ct:SymbRef symbIdRef="P0" />
</ct:Assign>
</po:Parameter>
</po:ProbOnto>
</Distribution>
To specify any given distribution unambiguously using ProbOnto, it is sufficient to declare its code name and the code names of its parameters.
More examples and a detailed specification can be found on the project website.
See also
List of probability distributions
Ontology (computer science)
Relationships among probability distributions
Web Ontology Language
References
External links
Leemis chart
Ultimate Univariate Probability Distribution Explorer – most likely the largest, free collection of univariate distributions and their features.
UncertML
Probability distributions | ProbOnto | [
"Mathematics"
] | 1,412 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
51,905,688 | https://en.wikipedia.org/wiki/ExPace | ExPace (ExPace Technology Corporation; also called CASIC Rocket Technology Company) is a Chinese state-owned space rocket company, based in Wuhan, Hubei, China. Its corporate compound is located at the Wuhan National Space Industry Base space industrial park. ExPace is a wholly owned subsidiary of missileer China Aerospace Science and Industry Corporation (CASIC), a Chinese state-owned company, and serves as its commercial rocket division. ExPace is focused on small satellite launchers to low Earth orbit. ExPace was established in February 2016. ExPace was founded as a Chinese commercial launch vehicle company.
Kuaizhou launch vehicles
ExPace's line of Kuaizhou (KZ; ) launch vehicles use solid rocket motors, thus being available all the time once built, without need to fuel the rockets. The Kuaizhou (Fast Vessel) launch vehicles are based on Chinese ASAT and BMD mid-course interceptor launch vehicles. Development on the KZ launch vehicles started in 2009. ExPace charges about US$10,000/kg for launches.
Kuaizhou 1 (KZ-1):
to SSO;
First launch: 25 September 2013;
Kuaizhou 1A:
to LEO;
First launch: 9 January 2017;
Kuaizhou 11 (KZ-11):
diameter; payload fairing; lift-off mass; to LEO; to SSO; US$10,000/kg;
First launch: 10 July 2020.
Marketplace
The first commercial space launch company in China, China Sanjiang Space Group Co., another subsidiary of CASIC, is planning it first launch for 2017, using ExPace's KZ-11 launch vehicle. The KZ-11 launch vehicle has launched but failed to reach orbit on 10 July 2020.
ExPace is in competition with several other Chinese space rocket startups, being LandSpace, Galactic Energy, LinkSpace, i-Space, OneSpace and Deep Blue Aerospace.
See also
LandSpace
LinkSpace
OneSpace
References
External links
Aerospace companies of China
Commercial launch service providers
Companies based in Wuhan
Transport companies established in 2016
Chinese companies established in 2016 | ExPace | [
"Astronomy"
] | 431 | [
"Rocketry stubs",
"Astronomy stubs"
] |
51,905,821 | https://en.wikipedia.org/wiki/Data%20exhaust | Data exhaust or exhaust data is the trail of data left by the activities of an Internet or other computer system users during their online activity, behavior, and transactions. This is part of a broader category of unconventional data that includes geospatial, network, and time-series data and may be useful for predictive analytics. Every visited website, clicked link, and even hovering with a mouse is collected, leaving behind a trail of data. An enormous amount of often raw data are created, which can be in the form of cookies, temporary files, logfiles, storable choices, and more. This information can help to improve the online experience, for example through customized content. It can be used to improve tracking trends and studying data exhaust also improves the user interface and the layout design. On the other hand, they can also compromise privacy, as they offer a valuable insight into the user's habits. For example, as the world's most popular website, Google, uses this data exhaust to refine the predictive value of their products.
The data that is collected by companies is often information that does not seem immediately useful. Although the information is not used by the company right away, it can be stored for future use or sold to someone else who can use the information. The data can help with quality control, performance, and revenue. Unlike primary content, these data are not purposefully created by the user, who is often unaware of their very existence. A bank for example would consider as primary data information concerning the sums and parties of a transaction, whilst secondary data might include the percentage of transactions carried out at a cash machine instead of a real bank.
Medical exhaust data
Most medical devices emit some form of exhaust data, such as many pacemakers, dialysis machines, and cameras used during surgery. The majority of this data is never captured, and is primarily abandoned after the surgery is completed, or the device makes its next routine check. Some issues have arisen regarding the use of the data captured by devices like pacemakers. This can lead to larger issues surrounding the use of this exhaust data. Using electronic health records (EMR) for research poses a large number of challenges, the most prevalent being the amount of data there is. This surplus of data is too much for people to sort through and analyze, thus creating a need for algorithms.
Solutions
Although data exhaust is not a new concept, the ubiquity of Internet-enabled gadgetry has exacerbated the scope and impacts of our passive digital trail. The collection and distribution of data thus generated is not illegal, but there are steps that must be taken to ensure that the use of this data is ethical. In order to ensure privacy of users, when the information is sold it can be anonymized. Also, users can be given the opportunity to opt-out of the selling of their information if they choose. Lastly, to build trust, websites can update their privacy policies so that they include all the data they will be collecting about the user.
See also
Alternative data
References
Data management
Internet privacy | Data exhaust | [
"Technology"
] | 626 | [
"Data management",
"Computing stubs",
"Data"
] |
51,905,980 | https://en.wikipedia.org/wiki/Environmental%20Development | Environmental Development is a quarterly peer-reviewed academic journal covering environmental science and policy published by Elsevier. In January 2018, Natarajan Ishwaran became the new editor-in-chief. He succeeded Eleanor Milne (Colorado State University, now Subject Editor for Climate Change) EIC from July 2015. The founding editor was Theo Beckers (Tilburg University).
The journal is associated with the Scientific Committee on Problems of the Environment (SCOPE) and is abstracted and indexed in the Emerging Sources Citation Index and Scopus.
References
External links
Environmental science journals
Elsevier academic journals
Academic journals established in 2012
Quarterly journals
English-language journals | Environmental Development | [
"Environmental_science"
] | 129 | [
"Environmental science journals",
"Environmental social science stubs",
"Environmental social science",
"Environmental science journal stubs"
] |
51,906,100 | https://en.wikipedia.org/wiki/Ts15 | Ts15 (Tityustoxin-15; α-KTx 21.1) is produced by the Brazilian yellow scorpion Tityus serrulatus. It targets voltage-gated potassium channels, primarily the subtypes Kv1.2 and Kv1.3.
Sources
Ts15 can be isolated from the venom of Tityus serrulatus, otherwise known as the Brazilian yellow scorpion. It is the deadliest scorpion toxin in Brazil, with a lethality rate of 0.15%. Ts15 is only one of many neurotoxins that can be found in the venom of Tityus serrulatus.
Chemistry
Ts15 is a peptide with a length of 36 amino acids, which are crosslinked by three disulfide bridges. The 27th position in the amino acid sequence undergoes N-linked glycosylation. Ts15 is a scorpion short toxin. The rest of the structure of the toxin remains unknown so far. Due to its low structural similarity to other members of the α-family (<30%), it cannot be easily compared to them.
Target
Kv channels are the main targets of Ts15. While other members of the α-family generally target both Kv channels and sodium channels (Nav channels), Ts15 only targets Kv channels. It mainly targets Kv1.2 and Kv1.3: it blocks the channel's current by 73% and 50% respectively. When all targeted channels are compared, Ts15 has the highest affinity for Kv1.2 channels. Besides these channels, Ts15 also targets Shaker IR channels, Kv1.6 channels and the Kv2.1 channels. The effects of Ts15 are voltage-independent, meaning it can bind to a channel in any state of activation, and they also are reversible.
Toxicity and treatment
Toxicity
The LD50 of Ts15 is unknown. The symptoms caused solely by Ts15 have not been studied extensively. However, Ts15 is known to block the Kv1.3 channels on autoreactive effector memory T-cells. The binding of the toxin triggers immunosuppression, by decreasing the calcium influx into the cell.
Treatment
In general, a sting by Tityus serrulatus is treated with scorpion antivenom serum, named Soro antiscorpionico. A human antibody fragment, serrumab, neutralises most of the venom. However, this antibody works on the entire venomous cocktail of the scorpion. Information about treating Ts15 alone is currently unavailable.
References
Neurotoxins
Ion channel toxins
Scorpion toxins | Ts15 | [
"Chemistry"
] | 533 | [
"Neurochemistry",
"Neurotoxins"
] |
51,906,281 | https://en.wikipedia.org/wiki/LGA%203647 | LGA 3647 is an Intel microprocessor compatible socket used by Xeon Phi x200 ("Knights Landing"), Xeon Phi 72x5 ("Knights Mill"), Skylake-SP, Cascade Lake-SP, and Cascade Lake-W microprocessors.
The socket supports a 6-channel memory controller, non-volatile 3D XPoint memory DIMMs, Intel Ultra Path Interconnect (UPI), as a replacement for Quick Path Interconnect (QPI), and 100G Omni-Path interconnect and also has a new mounting mechanism which does not use a lever to secure it in place but the CPU cooler's pressure and its screws to secure it in place.
Variants
There are two sub-versions of this socket with differences also in the ILM (Independent Loading Mechanism, pitch of center screws changed slightly and a more visible one being that the guiding pins are in other corners). The processor socket and the matching notches on the processor are at different location, preventing insertion of an incompatible processor and preventing use of the wrong heatsink in a system. The more common P0 variant has two sub-options for heatsink mounting – designated as square ILM and narrow ILM, choice of which depends on the server and mainboard design (likely based on space constraints).
LGA3647-0 (socket P0) used for Skylake-SP and Cascade Lake-SP processors
LGA3647-1 (socket P1) used for Xeon Phi x200 processors
References
Intel CPU sockets | LGA 3647 | [
"Technology"
] | 326 | [
"Computing stubs"
] |
64,547,372 | https://en.wikipedia.org/wiki/Knowledge%20engine | A knowledge engine is part of a decision-support system that combines data with data models and inference rules to provide an interface for people who want to make decisions or discover related data. It may involve automatically extracting and structuring knowledge from less-structured sources, using these models and rules.
History
In the late 1990s, the Decision Support Group at the University of Fribourg developed a model for decision support software. This described the interface between data and models on one hand, and graphical interfaces for exploring them and making decisions on the other, as a knowledge engine. They also developed a mathematical modeling language, LPL, in concert with that work.
With the rise of the semantic web, natural language processing, and topical knowledge bases, a number of other analytical tools have been categorized as knowledge engines, including in genomics (KnowEnG), modeling human action (PaStaNet), and speeding up general-purpose question answering.
General-purpose search and discovery tools such as Wolfram Alpha have also described themselves as knowledge engines.
See also
Knowledge engineering
Knowledge engineer
References
Knowledge engineering | Knowledge engine | [
"Technology",
"Engineering"
] | 219 | [
"Systems engineering",
"Knowledge engineering",
"Computer science stubs",
"Computer science",
"Computing stubs"
] |
64,547,519 | https://en.wikipedia.org/wiki/Transition%20metal%20isocyanide%20complexes | Transition metal isocyanide complexes are coordination compounds containing isocyanide ligands. Because isocyanides are relatively basic, but also good pi-acceptors, a wide range of complexes are known. Some isocyanide complexes are used in medical imaging.
Scope of isocyanide ligands
Several thousand isocyanides are known, but the coordination chemistry is dominated by a few ligands. Common isonitrile ligands are methyl isocyanide, tert-butyl isocyanide, phenyl isocyanide, and cyclohexylisocyanide.
Isocyanides are electronically similar to CO, but for most R groups, isocyanides are superior Lewis bases and weaker pi-acceptors. Trifluoromethylisocyanide is the exception, its coordination properties are very similarly to those of CO.
Because the CNC linkage is linear, the cone angle of these ligands is small, so it is easy to prepare polyisocyanide complexes. Many complexes of isocyanides show high coordination numbers, e.g. the eight-coordinate cation . Very bulky isocyanide ligands are also known, e.g. C6H3-2,6-Ar2-NC (Ar =aryl).
Di- and triisocyanide ligands are well developed, e.g., (CH2)n(NC)2. . Usually steric factors force these ligands to bind to two separate metals, i.e., they are binucleating ligands. Chelating diisocyanide ligands require elaborate backbones.
Synthesis
Because of their low steric profile and high basicity, isocyanide ligands often install easily, e.g. by treating metal halides with the isocyanide. Many metal cyanides can be N-alkylated to give isocyanide complexes.
Reactions
Typically, isocyanides are spectator ligands, but their reduced and oxidized complexes can prove reactive by virtue of the unsaturated nature of the ligand
Cationic complexes are susceptible to nucleophilic attack at carbon. In this way, the first metal carbene complexes where prepared. Because isocyanides are both acceptors and donors, they stabilize a broader range of oxidation states than does CO. This advantage is illustrated by the isolation of the homoleptic vanadium hexaisocyanide complex in three oxidation states, i.e., [V(CNC6H3-2,6-Me2)6]n for n = -1, 0, +1.
Because isocyanides are more basic donors ligands than CO, their complexes are susceptible to oxidation and protonation. Thus, is easily protonated, whereas its counterpart is not:
Fe(CNR)5 + H+ → [HFeL5]+
Fe(CO)5 + H+ → no reaction
Some electron-rich isocyanide complexes protonate at N to give aminocarbyne complexes:
LnM-CNR + H+ → [LnM≡CN(H)R]+
Isocyanides sometimes insert into metal-alkyl bonds to form iminoacyls.
Structure and bonding
Isocyanide complexes often mirror the stoichiometry and structures of metal carbonyls. Like CO, isocyanides engage in pi-backbonding. The M-C-N angle provides some measure of the degree of backbonding. In electron-rich complexes, this angle is usually deviates from 180°. Unlike CO, cationic and dicationic complexes are common. RNC ligands are typically terminal, but bridging RNC ligands are common. Bridging isocyanides are always bent. General trends can be appreciated by inspection of the homoleptic complexes of the first row transition metals.
Homoleptic complexes
IR spectroscopy
The νC≡N band in isocyanides is intense in the range of 2165–2110 cm−1. The value of νC≡N is diagnostic of the electronic character of the complex. In complexes where RNC is primarily a sigma donor ligand, νC≡N shifts to higher energies vs free isocyanide. Thus, for , νC≡N = 2152, 2120 cm−l. In contrast, for the electron-rich species Fe2(CNEt)9, νC≡N = 2060, 1920, 1701, 1652 cm−l.
See also
Cyanometalate - coordination compounds containing cyanide ligands (coordinating via C)
Transition metal nitrile complexes - coordination compounds containing nitrile ligands, which are isomers of isonitriles
References
Coordination complexes
Isocyanides | Transition metal isocyanide complexes | [
"Chemistry"
] | 1,005 | [
"Isocyanides",
"Coordination chemistry",
"Functional groups",
"Coordination complexes"
] |
64,547,529 | https://en.wikipedia.org/wiki/Mark%20and%20space | Mark and space are terms used in telecommunications to describe two different signal states of a communications signal, generally at the physical layer of a communications system. The terms derive from the early days of the electric telegraph system, where the marking state would cause a mark to be output on paper, and the spacing state would create no mark.
The terms would continue to be used in systems such as RS-232, with similar conventions, that "mark" would be encoded by a negative voltage (or current flow), and "space" by a positive voltage (or no current flow). In such systems, the line is typically left in the "mark" state when idle.
"Mark" is generally identified with the binary digit "1" and "space" with the binary digit "0".
See also
Baud
Break key
Laws of Form
Morse code
References
Telecommunication theory | Mark and space | [
"Technology"
] | 176 | [
"Computing stubs",
"Computer science",
"Computer science stubs"
] |
64,547,814 | https://en.wikipedia.org/wiki/Bruno%20Oberle | Bruno Oberle is a Swiss environmental scientist and economist. He is currently the president of the WRF, World Resources Forum.
Biography
Oberle was born in St. Gallen, Switzerland on 12 October 1955, and grew up in Locarno and Zürich. He took biology and environmental sciences at ETH Zurich and obtained his PhD.
Oberle was Professor at the École Polytechnique Fédérale de Lausanne, Chair of the Green Economy and Resource Governance program at the École Polytechnique Fédérale de Lausanne, and is a former director of the Swiss Federal Office for the Environment and State Secretary for the Environment. Presently, he is Director General of the International Union for Conservation of Nature.
References
1955 births
Living people
Academic staff of the École Polytechnique Fédérale de Lausanne
Environmental scientists
People associated with the International Union for Conservation of Nature
People from the canton of St. Gallen
Swiss civil servants
ETH Zurich alumni | Bruno Oberle | [
"Environmental_science"
] | 187 | [
"Environmental scientists"
] |
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