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66,452,617 | https://en.wikipedia.org/wiki/Leucoagaricus%20gaillardii | Leucoagaricus gaillardii is a species of fungus belonging to the family Agaricaceae.
It is native to Northern Europe.
References
Agaricaceae
Fungus species | Leucoagaricus gaillardii | [
"Biology"
] | 38 | [
"Fungi",
"Fungus species"
] |
66,452,710 | https://en.wikipedia.org/wiki/The%20Zoologist%27s%20Guide%20to%20the%20Galaxy | The Zoologist's Guide to the Galaxy. What Animals on Earth Reveal about Aliens – and Ourselves is a 2020 popular science book by the Cambridge University zoologist Arik Kershenbaum. It discusses the possible nature of life on other planets, based on the study of animal life on Earth.
The book argues that the evolutionary processes that are observed operating on Earth are universal, and a necessary requirement for the presence of complex life on any planet. As a result, many aspects of animal behavior are likely to be present in the equivalent lifeforms on alien planets. This includes certain features of social behavior, communication, and movement, the evolutionary origin of which on Earth is underpinned by universal processes.
The book has been praised by critics for its accessibility and engaging conversational tone, and described by Richard Dawkins as "A wonderfully insightful sidelong look at Earthly biology".
Author
Kershenbaum is a College Lecturer at Girton College, University of Cambridge, and an academic visitor at the Department of Zoology. He studies animal communication and particularly the vocal communication of wolves and dolphins.
Book
Context
Although the field of astrobiology usually investigates possibilities of simple lifeforms that may exist on alien planets, The Zoologist's Guide to the Galaxy considers the possibilities of complex life, and in particular, life that might be considered as animal life. The book begins by laying out the argument that evolution by natural selection is the only mechanism by which complex life can evolve. It then examines the implications of natural selection for life on other planets. The book ends by examining the question of whether humanity is a parochial Earth-centric concept, or whether intelligent alien life should also be considered human.
The book draws on the work of paleontologist Simon Conway Morris on convergent evolution, and on Universal Darwinism, popularised by Richard Dawkins.
Contents
1. Introduction
Sets out the basis of the claims made in the book, that observing animal life of Earth can tell us about the nature of life on other planets.
2. Form vs Function: What is Common Across Worlds?
Why natural selection is both a universal and predictable process, the existence and results of which are likely to be present on alien planets.
3. What are Animals and What are Aliens?
Examines the definition of animals, from the historical definitions derived from observation (e.g. Aristotle), to modern phylogenetic relationships. The book argues that a purely phylogenetic definition of what is an animal cannot be sufficient for classifying alien life.
4. Movement – Scuttling and Gliding Across Space
How the constrains of physics and mechanics combined with evolutionary laws to produce the movement strategies we see on Earth, and why many of these strategies (e.g. legs) are likely to exist on other planets too.
5. Communication Channels
The different ways that animals communicate: sound, vision, smell, and what might lead these same channels to be used by alien life to communicate.
6. Intelligence (Whatever That Is)
How different forms of intelligence evolved on Earth, and how similar intelligences might evolve on other planets.
7. Sociality – Cooperation, Competition and Teatime
The processes driving the evolution of social behavior are well understood, and, the book claims, are almost inevitably going to be driving alien sociality as well.
8. Information – A Very Ancient Commodity
Truth and lies, information about the environment and about oneself, are all under evolutionary pressure, and principles of game theory are universal enough to tell us what information aliens are likely to use.
9. Language – The Unique Skill
Humans are the only species on Earth that have a true language, but the processes that led to language evolution may be occurring on other worlds as well.
10. Artificial Intelligence – A Universe Full of Bots?
Some scientists (e.g. astronomer Seth Shostak) have proposed that alien life is more likely to be technological rather than biological. This chapter explores whether such artificial intelligence would also be subject to the laws of evolution.
11. Humanity, As We Know It
Drawing on the principles of the previous chapter, Kershenbaum emphasises that underlying similarities between life on Earth and that on other planets implies that the title of human should be more broadly applied than just being restricted to Homo sapiens.
12. Epilogue
Awards
BBC Science Focus magazine's 15 of the best space and astronomy books 2020
The Times Best science books of the year 2020
Reception
The Zoologist's Guide to the Galaxy was featured as one of the New York Times Editors' Choice of books.
Professor Lewis Dartnell, writing in The Times, summarised, "Pondering scientifically on the concept of the extraterrestrial, of universalities and alternatives, is to hold a full-length mirror up to ourselves. This allows us to deconstruct everything from our physiology to psychology, and so explore why humans are the way we are. To comprehend the alien is to know thyself."
In The Sunday Times, titled Using Darwinism to imagine what extraterrestrials may really be like James McConnachie wrote, "Arik Kershenbaum is a Cambridge zoologist who wants to prepare us for first contact. When we finally discover aliens, what might they be like?... Where much writing on astrobiology is joyously speculative, Kershenbaum is doggedly cautious, building his case from first evolutionary principles."
Primatologist Frans de Waal wrote, "If you don't want to be surprised by extraterrestrial life, look no further than this lively overview of the laws of evolution that have produced life on earth. Assuming these laws to be universal, Arik Kershenbaum predicts what alien organisms might look like."
References
External links
The Zoologist's Guide to the Galaxy on the Penguin Books website.
The Zoologist's Guide to the Galaxy reviewed on the University of Cambridge website.
2020 non-fiction books
Popular science books
Evolutionary biology
Astrobiology
Viking Press books | The Zoologist's Guide to the Galaxy | [
"Astronomy",
"Biology"
] | 1,208 | [
"Evolutionary biology",
"Origin of life",
"Speculative evolution",
"Astrobiology",
"Biological hypotheses",
"Astronomical sub-disciplines"
] |
66,453,544 | https://en.wikipedia.org/wiki/Lichenostigma%20cosmopolites | Lichenostigma cosmopolites is a species of lichenicolous fungus belonging to the family Phaeococcomycetaceae. It was described as new to science in 1999 by lichenologists Josef Hafellner and Vicent Calatayud. The fungus grows parasitically on Xanthoparmelia lichens. In India it has been reported from the thallus of Xanthoparmelia stenophylla.
It has cosmopolitan distribution.
References
Arthoniomycetes
Fungi described in 1999
Fungi of India
Taxa named by Josef Hafellner
Fungus species | Lichenostigma cosmopolites | [
"Biology"
] | 121 | [
"Fungi",
"Fungus species"
] |
66,454,771 | https://en.wikipedia.org/wiki/Laser%20sight | A laser sight is a device attached or integral to a firearm to aid target acquisition. Unlike optical and iron sights where the user looks through the device to aim at the target, laser sights project a beam onto the target, providing a visual reference point.
Although lasers in the visible part of the spectrum are most common, invisible infrared (IR) lasers may be used in conjunction with a night vision device. As they are offset from the barrel, laser sights need to be zeroed in, much like a conventional sight, so that the beam intercepts the point of impact at a chosen distance. Devices may include one or both types of laser, with some models also incorporating a rangefinder, flashlight, or IR illuminator. Laser sights may be attached to the existing sighting mechanism, the trigger guard, via a rail system, or can be integrated into replacement components such as the guide rod or grip plates. Some variants are also incorporated into other attachments such as foregrips.
Laser sights are primarily used by military and law enforcement, although have some civilian use for hunting and self defense. They are also found on some less-lethal weapons, such as Taser electroshock weapons.
History
The laser sight was first brought to market by Laser Products Corporation (today known as SureFire) in 1979. The design was patented in 1978 by Surefire founder Dr. John Matthews, a pioneer in the field of Photonics, and his business partner Ed Reynolds. The ruggedized helium-neon gas laser was custom built into the extended Pachmayr grip of a .357 Magnum Colt Trooper and fed by a rechargeable 12-volt battery. The popularity of this new product among SWAT and special forces led Laser Products Corp. to design and produce similar laser sights for other firearms employed by military and law enforcement such as the Colt M16, Remington 870, H&K MP5, and Ruger Mini-14.
Laser sights were popularized outside of military and law enforcement when Laser Products fitted The Terminator's iconic weapon, a .45 Longslide pistol, with a custom He-Ne laser. Today, most modern laser sights are solid-state lasers, as opposed to the original gas design. Modern weapon-mounted lasers and combat lights produced by SureFire continue to be widely used by the U.S. Military, its allies, and law enforcement.
Purpose
Benefits
Accuracy
The use of laser sights is associated with increased accuracy in general, increasing the probability of hitting the target especially in low light conditions. The projected dot speeds up target acquisition, decreasing the time required for the shooter to aim and fire, as well as decreasing the time necessary for follow-up shots. Laser sights also aid in point shooting, where the shooter relies on hand eye coordination rather than aiming with a traditional sight, this most often occurs and is taught when conducting CQM (close quarters marksmanship) or urban operations where engagement distances are less than , and the shooter is operating in confined spaces. This is of particular use when the user does not have time or is unable to obtain a proper sight picture before firing; for example, the use of ballistic shields or gas masks may obstruct access to the sights. Lasers also increase accuracy when shooting from an unconventional stance.
Training
Laser sights are also a useful training aid. They allow users to practice dry-fire drills while being able to see the point of impact: this has significant safety benefits. Training with laser sights has been shown to improve shooting skills faster, although both instructors and manufacturers recommended that users continue training without lasers to avoid becoming dependent on them.
Deescalation
By providing a visual indication of where the gun is aimed, laser sights add an extra factor of intimidation. Studies of law enforcement indicate that suspects faced with laser sights are significantly more likely to surrender, even if they themselves are armed.
Use with Night Vision Devices
IR (infrared) lasers can be used with night vision devices, as the bulk of a head-mounted night vision device makes aiming with iron sights or a conventional optic difficult. These lasers cannot be seen by the naked eye and are only visible when utilizing night vision devices. Some IR laser units, like the AN/PEQ-2, utilize two separate lasers: a narrow "aiming" laser and a more diffuse "illuminator". The aiming laser is used to estimate point of impact, while the illuminator is used to better visualize targets and the environment through the night vision device. However, even with laser sights, shot groupings are still inferior to those achieved in daytime, and the degree of improvement is highly dependent on correct set up of the system.
Drawbacks
Long range accuracy
Where a laser beam travels in a straight line, the path of a bullet gradually deviates after it leaves the barrel due to external forces such as gravity, wind, and even the rotation of the earth. This is a significant issue for long distance shooting; shorter range weapons such as handguns are less affected. Another related issue is that the beam widens over distance, meaning that instead of projecting a small dot, a much larger circle may be produced.
Visibility in bright light
Visibility of laser sights deteriorates in bright light. Green lasers are more effective in bright conditions, however they are more complex to produce so are often larger and more expensive than red lasers.
Aerial targets
Laser sights cannot be used for hunting flying game in the daylight, as neither the beam nor dot are visible. A further risk to aircraft is also an issue, as even civilian grade lasers are capable of hitting a plane from 2 miles away.
Batteries
Laser sights rely on batteries to work. As such, they require regular maintenance and may fail during use. Non-water resistant models also risk electrical damage through water ingress.
Added mass
As with all firearms attachments, laser sights add mass to the firearm. This is particularly significant for handguns, as many holsters aren't designed to accommodate them.
Risk of eye damage
Lasers can easily cause damage to the eyes. Visible lasers are unlikely to cause permanent damage due to the blink reflex, however IR lasers do not trigger this and thus pose a significant risk.
Revealing position
The use of laser sights poses a risk in tactical scenarios as they may reveal the user's location, although this can be mitigated by only turning on the laser when needed. An additional consideration for military and law enforcement is whether the enemy has night vision capabilities; if so, IR lasers will be visible to them.
Difficulty zeroing
Laser sights are somewhat more difficult to zero than conventional sighting systems. IR lasers in particular can take in excess of an hour to properly zero, depending on the methods used.
Boresights
Laser boresights differ from laser sights in that they are not intended, or capable, of being used at the same time as the firearm; instead, they are intended to aid in zeroing the firearm. A boresight is a laser in the shape of a cartridge. The user chambers a boresight of the appropriate calibre which projects a laser beam directly down the barrel, providing a visual indicator of the point of impact at a given range. The user then adjusts the sights until they align with the dot. Boresighting suffers from the same weakness as laser sights in that while the beam is straight, the path of the bullet curves; as such it is not a substitute for traditional zeroing, rather they serve to speed up the process.
Law
Restrictions on laser sights vary by jurisdiction. Another consideration is the legality of the laser itself: the power output of military and law enforcement issue devices often exceeds that permitted for civilian use.
U.S.
In the U.S. laser sights are mostly legal for self-defense purposes, however their use for hunting is more strictly regulated.
UK
UK firearms legislation does not mention accessories such as laser sights. There are no restrictions on using laser sights on rifles at a range.
Users
U.S. police
In a 2019 survey of US police officers, less than 13% used laser sights on duty, with only 32% saying that their agency permitted their use.
See also
AN/PEQ-2
AN/PEQ-15
AN/PEQ-16
AN/PEQ-6
Insight Technology
L3Harris
References
Firearm sights
Firearms
Firearm terminology
Firearm components
Military technology
Military electronics
Military equipment
21st-century military equipment
20th-century military equipment
Laser aiming modules | Laser sight | [
"Technology"
] | 1,688 | [
"Firearm components",
"Components"
] |
66,456,099 | https://en.wikipedia.org/wiki/Bassam%20Izzuddin | Bassam Izzuddin is an author, developer and professor of computational structural mechanics at the Department of Civil and Environmental Engineering at the Imperial College London where he is coordinator of three courses at advanced undergraduate and masters level. He is the founder and developer of ADAPTIC, an adaptive static and dynamic structural analysis program which has been developed to provide an efficient tool for the nonlinear analysis of steel and composite frames, slabs, shells and integrated structures.
In 2016, he won the IStructE award for the best research paper in structural mechanics.
References
Year of birth missing (living people)
Living people
English mechanical engineers
Computational physicists
Alumni of Imperial College London
American University of Beirut alumni
Academics of Imperial College London | Bassam Izzuddin | [
"Physics"
] | 141 | [
"Computational physicists",
"Computational physics"
] |
66,457,520 | https://en.wikipedia.org/wiki/Nitrospira%20inopinata | Nitrospira inopinata is a bacterium from the phylum Nitrospirota. This phylum contains nitrite-oxidizing bacteria playing role in nitrification. However N. inopinata was shown to perform complete ammonia oxidation to nitrate thus being the first comammox bacterium to be discovered.
N. inopinata was cultivated in enrichment culture. Initial inoculum was obtained in 2011 from microbial biofilm growing on metal surface of the pipe covered by hot water (56 °C, pH 7.5), which was raised from 1 200m deep oil exploration well. The well was located in Aushiger, North Caucasus, Russia. The growth in pure culture was achieved in 2017.
Genome of N. inopinata was released in 2015 represented by 3.3 Mbp, with 3 116 genes and 59.2% GC content. NCBI accession number is LN885086.
References
Nitrospirota
Nitrogen cycle
Bacteria described in 2015 | Nitrospira inopinata | [
"Chemistry"
] | 211 | [
"Nitrogen cycle",
"Metabolism"
] |
66,458,011 | https://en.wikipedia.org/wiki/DIN%2066303 | The German standard DIN 66303 is a character set standard, which is used for character encoding in computer systems. The standard DIN 66303 bears the title "Information Technology: 8-Bit-Code" and was established in November 1986 (DIN 66303:1986-11). The most recent edition is from June 2000 (DIN 66303:2000-06).
The character set of the 2000 edition (DIN 66303:2000-06) corresponds in layout and repertoire to the international standard ISO/IEC 8859-1. The still often-used forerunner DIN 66303:1986-11 specified two code pages, the General Reference Version of the 8-Bit-Code (, ARV8) and the German Reference Version of the 8-Bit-Code (, DRV8).
DRV8 is an extension of DIN 66003 (the German adaptation of ISO/IEC 646) with European characters, whereas ARV8 represents a re-arrangement of the DIN 66003 characters to their internationally used (ISO-8859-1 or DEC MCS) code points.
Tables for the 1986 edition
DIN 66303:1986-11 – German Reference Version of the 8-bit Code (DRV8)
The DRV8 code corresponds to ISO-8859-1 with certain characters swapped, such as to make it an extension of DIN 66003 as opposed to of ASCII.
DIN 66303:1986-11 – General Reference Version of the 8-Bit-Code (ARV8)
The name "ARV8" is associated with ISO-8859-1 without rearrangement. Shown below is the common subset of the Latin parts of ISO 8859, which corresponds to the definition of ARV8 in the 1986 edition of DIN 66303.
References
Character encoding
ISO/IEC 8859
66303 | DIN 66303 | [
"Technology"
] | 386 | [
"Natural language and computing",
"Character encoding"
] |
66,458,263 | https://en.wikipedia.org/wiki/Nitrospinota | Nitrospinota is a bacterial phylum. Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans. By oxidation of nitrite to nitrate they are important in the process of nitrification in marine environments.
Although the genus Nitrospina is an aerobic bacterium, it was shown to oxidize nitrite also in oxygen minimum zone of the ocean. Depletion of oxygen in such zones leads to preference of anaerobic processes such as denitrification and nitrogen loss through anammox. Nitrospina thus outweigh nitrogen loss by nitrification also in these oxygen depleted zones.
Among the cultivated isolates within the genus Nitrospina are Nitrospina gracilis and Nitrospina watsonii. Further genomes were resolved by culture-independent metagenome binning. The two Nitrospina species are, however, distantly related to environmentally abundant uncultured Nitrospinota. The two other strains were cultivated in 2020 each in the binary culture with alphaproteobacterial heterotroph. They are called "Candidatus Nitrohelix vancouverensis" and "Candidatus Nitronauta litoralis". "Nitrohelix vancouverensis" is closely related to uncultivated environmentally abundant Nitrospinota clades 1 and 2.
Taxonomy
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)
Phylum Nitrospinota Lücker et al. 2021
Class "Nitrospinia" Lücker et al. 2013
Order "Nitrospinales" Lücker et al. 2013
Family Nitrospinaceae Garrity, Bell & Lilburn 2006
Genus "Candidatus Nitrohelix" Mueller et al. 2021
"Ca. N. vancouverensis" Mueller et al. 2021
Genus "Candidatus Nitromaritima" Ngugi et al. 2016
Genus "Candidatus Nitronauta" Mueller et al. 2021
"Ca. N. litoralis" Mueller et al. 2021
Genus Nitrospina Watson & Waterbury 1971
N. gracilis Watson & Waterbury 1971
"N. watsonii" Spieck et al. 2014
References
Nitrogen cycle
Bacteria phyla
Bacteria | Nitrospinota | [
"Chemistry",
"Biology"
] | 505 | [
"Prokaryotes",
"Nitrogen cycle",
"Bacteria",
"Microorganisms",
"Metabolism"
] |
66,458,571 | https://en.wikipedia.org/wiki/Eutreptia | Eutreptia is a genus of Euglenozoa belonging to the family Eutreptiidae.
The genus was first described by Maximilian Perty in 1852.
The genus has cosmopolitan distribution.
Species:
Eutreptia globulifera Goor
Eutreptia lanowii Steuer
Eutreptia papillifera Péterfi
Eutreptia pascheri Skvortsov
Eutreptia pertyi Pringsheim
Eutreptia pyrenoidifera Matvienko
Eutreptia scotica Butcher
Eutreptia thiophila Skuja
Eutreptia viridis Perty
References
Euglenozoa | Eutreptia | [
"Biology"
] | 141 | [
"Algae stubs",
"Algae"
] |
66,458,637 | https://en.wikipedia.org/wiki/Eutreptiella | Eutreptiella is a genus of Euglenozoa belonging to the family Eutreptiidae.
The genus was first described by A. M. da Cunha in 1914.
The genus has cosmopolitan distribution.
Species:
Eutreptiella braarudii Throndsen
Eutreptiella cornubiense Butcher
Eutreptiella dofleinii (Schiller) Pascher
Eutreptiella elegans (Schiller) Pascher
Eutreptiella eupharyngea Moestrup & R.E.Norris
Eutreptiella gymnastica Throndsen
Eutreptiella hirudoidea Butcher
Eutreptiella marina A.M.da Cunha
Eutreptiella pascheri (Schiller) Pascher
Eutreptiella pomquetensis (McLachlan, Seguel & Fritz) Marin & Melkonian
References
Euglenozoa | Eutreptiella | [
"Biology"
] | 205 | [
"Algae stubs",
"Algae"
] |
66,459,527 | https://en.wikipedia.org/wiki/First-hop%20redundancy%20protocol | A first hop redundancy protocol (FHRP) is a computer networking protocol which is designed to protect the default gateway used on a subnetwork by allowing two or more routers to provide backup for that address; in the event of failure of an active router, the backup router will take over the address, usually within a few seconds. In practice, such protocols can also be used to protect other services operating on a single IP address, not just routers.
Examples of such protocols include (in approximate order of creation):
Hot Standby Router Protocol (HSRP) - Cisco's initial, proprietary standard developed in 1998
Virtual Router Redundancy Protocol (VRRP) - an open (albeit patent-encumbered) standard protocol based largely on Cisco's HSRP
Common Address Redundancy Protocol (CARP) - patent-free, unencumbered alternative to Cisco's HSRP and the IETF's VRRP, developed in October 2003
Extreme Standby Router Protocol (ESRP) - Extreme Networks' proprietary standard with fast failover and layer 2 protection
Gateway Load Balancing Protocol (GLBP) - a more recent proprietary standard from Cisco that permits load balancing as well as redundancy
Routed Split multi-link trunking (R-SMLT) - an Avaya redundancy protocol
NetScreen Redundancy Protocol (NSRP) - a Juniper Networks proprietary router redundancy protocol providing load balancing
Chassis Cluster Redundant Ethernet - a Juniper Networks proprietary Ethernet redundancy protocol, used on its SRX platform
Multi-active Gateway Protocol (MAGP) - a Mellanox proprietary protocol based on VRRP that allows active-active operation
References
Internet protocols | First-hop redundancy protocol | [
"Technology"
] | 349 | [
"Computing stubs",
"Computer network stubs"
] |
66,459,837 | https://en.wikipedia.org/wiki/Kepler-1638 | Kepler-1638 is a G-type main-sequence star located about 5,000 light years away in the constellation of Cygnus. One known exoplanet has been found orbiting the star: Kepler-1638b.As of January 2021, Kepler-1638 is the farthest star with a known exoplanet orbiting in the habitable zone.
Planetary system
Kepler-1638 b is an exoplanet in orbit of its star, Kepler-1638, located in the constellation Cygnus. It was confirmed in 2016 as part of a study statistically validating hundreds of Kepler planets. Based on the parameters in the discovery paper, the planet is a super-Earth, with a radius of , and a predicted mass of 4.16 Earths. It has an orbit of days in its system's habitable zone and orbits 0.745 AU from its star. It is the most distant known exoplanet that is considered potentially habitable.
However, these parameters were estimated before the first measurement of the host star's parallax was published as part of Gaia DR2 in 2018. The Gaia parallax suggests a distance of about , much farther than the pre-Gaia estimate of about . This revised distance results in a significantly larger estimate of the radius of the star, and thus of the planet, with a 2018 study finding a planetary radius of . This would make the planet an ice giant like Neptune, and thus not potentially habitable in an Earth-like sense.
References
See also
List of potentially habitable exoplanets
G-type main-sequence stars
Cygnus (constellation)
Planetary systems with one confirmed planet
Kepler objects of interest | Kepler-1638 | [
"Astronomy"
] | 345 | [
"Cygnus (constellation)",
"Constellations"
] |
66,460,551 | https://en.wikipedia.org/wiki/Presidential%20call%20button | Some presidents of the United States have had a call button in the Oval Office of the White House that could call aides. The earliest incarnation dates to 1881 or before, and the modern call button has been in a wooden box on the Resolute desk since at least the George W. Bush presidency (2001–2009).
History
Past call buttons and buzzers
Before the mid 1800's, a series of call bells was installed in the White House and used as a form of staff communication. This system was followed by a battery operated device, used by the President, that could be used to call on staff. The White House was wired for electricity in 1891 allowing for simple wired call-buttons.
An 1881 letter written by White House disbursing agent William H. Crook refers to an electric bell attached to president James Garfield's desk.
Betty C. Monkman notes in The White House: It's Historic Furnishings & First Families that the Treaty table, also known as the Grant Cabinet table, has the remains of a call button system still attached to it, but does not state when this system was used.
Lyndon Johnson had a series of buttons, or keys, to summon different drinks to the Oval Office, Cabinet Room, and "Little Lounge" (a room just next to the Oval Office). In the Oval Office the keys were on the table behind the president's desk. The four keys were for coffee, tea, Coca-Cola and Fresca; when pressed, a butler would fulfill the president's drink request.
During Johnson's presidency he was known for having extramarital affairs, with what Robert Dallek in his book Lone Star Rising: Lyndon Johnson and His Times called a harem of women. Ronald Kessler in his book Inside the Whitehouse describes multiple sexual encounters between Johnson and his secretaries in the Oval Office including one where his wife, Ladybird Johnson, walked in on Johnson and a secretary in the midst of having sex, leading to the installation of a buzzer system to warn him if Ladybird was on her way.
Modern call button
The modern call button sits in an approximately wooden box marked with a golden presidential seal and has been on the Resolute desk since at least the George W. Bush presidency. According to Richard Branson, President Obama repurposed it to order tea for his White House guests.
During Donald Trump's past and present presidency, when pressed, a signal summons a valet who brings a Diet Coke on a silver platter. At one time Walt Nauta had this job. Trump reportedly also used the button to request lunch, and to pull pranks on new visitors to the White House. Trump stated to one reporter that "everyone thinks it is [the nuclear button]" and that people "get a little nervous when I press that button."
In the first few days of Joe Biden's presidency, it was reported that he had the button removed; however, it appeared to return a few weeks later when a White House official told Politico that the button was back on the desk with an unspecified purpose. James Corden has said that Joe Biden has an "ice cream button" on his desk.
On January 20, 2025, Trump's Diet Coke button reportedly was back.
References
External links
Alarms
Furnishings of the White House | Presidential call button | [
"Technology"
] | 676 | [
"Warning systems",
"Alarms"
] |
66,460,710 | https://en.wikipedia.org/wiki/Kepler-277 | Kepler-277 is a large yellow star about away in the constellation of Lyra. It is 1.69 and 1.12 , with a temperature of 5946 K, a metallicity of -0.315 [Fe/H], and an unknown age. For comparison, the Sun has a temperature of 5778 K, a metallicity of 0.00 [Fe/H], and an age of about 4.5 billion years. The large radius in comparison to its mass and temperature suggest that Kepler-277 could be a subgiant star.
Planetary system
Kepler-277 hosts two exoplanets, detected in 2014 via the transit method. Named Kepler-277b and Kepler-277c, they are super-Earths, notable for their unusually high densities.
See also
List of stars in Lyra
References
Subgiant stars
Lyra
Planetary transit variables
Planetary systems with two confirmed planets
J19061996+3904379
1215 | Kepler-277 | [
"Astronomy"
] | 201 | [
"Lyra",
"Constellations"
] |
66,461,852 | https://en.wikipedia.org/wiki/Margarita%20del%20Val | Margarita del Val Latorre (born 1959) is a Spanish chemist, immunologist, and virologist. She coordinates the Salud Global ("Global Health") platform run by the Spanish National Research Council (CSIC).
Early life and education
Margarita del Val was born in Madrid in 1959 to the chemists Manuel del Val and Consuelo Latorre. del Val attended the Autonomous University of Madrid (UAM) starting in 1976, during the Transition. During this time, increasing protests on university grounds against the Francoist dictatorship culminated in all Spanish universities going on strike starting in 1973, which was ongoing when she arrived at the university. In the absence of any classes, del Val and other students read books and played games. One book she read described how proteins were made in cells, which influenced her decision to study biochemistry and she completed her thesis in 1985 under the supervision of .
Career
In the 1980s, del Val began working at the , a research institute at the UAM jointly run by the university and the CSIC. After completing her doctorate in 1986, she left for West Germany, spending two years at the Federal Research Centre for Virus Diseases of Animals in Tübingen, a now-defunct research institution of the Friedrich Loeffler Institute. She then spent three years at the University of Ulm. del Val returned to Spain in the 1990s, having developed an experimental vaccine design based on isolated T-cell epitopes. Afterwards, del Val stayed abroad at the National Institutes of Health in Bethesda, Maryland and McGill University in Montreal, before spending twenty years at the Carlos III Health Institute.
In April 2020, del Val helped set up and launch the Salud Global ("Global Health") program, a CSIC project facilitating COVID-19 research between over 300 Spanish research groups. del Val has provided her thoughts on Spain's experience with the COVID-19 pandemic and requested an investigation into Spain's handling of the pandemic.
Selected publications
Awards and honors
In 2015 del Val was named a corresponding academician of the Royal Academy of Pharmacy. In 2021 she received the "Medalla de Honor a los Valores Sociales" from Menéndez Pelayo International University for her work in Spain during the COVID-19 pandemic.
Personal life
del Val is married to the biologist Enrique J. de la Rosa, who she met at the UAM in 1977. She has a son and daughter.
References
Living people
Spanish scientists
Women biochemists
Women immunologists
Autonomous University of Madrid alumni
1959 births | Margarita del Val | [
"Chemistry"
] | 520 | [
"Biochemists",
"Women biochemists"
] |
66,462,192 | https://en.wikipedia.org/wiki/List%20of%20sea%20stacks%20in%20Scotland | This is a list of stacks in Scotland that are surrounded by the sea at high tide.
The highest stacks in Scotland are Stac an Armin and Stac Lee in the St Kilda archipelago and the Old Man of Hoy, Orkney. Some provide well known and challenging rock climbing routes. There are 275 or more stacks in the country; their names are influenced by the Norse, Gaelic and English languages. In Shetland, where there are over 100 stacks, the names are often from Norn, a local variant of Norse.
The sport of stack climbing did not take off until the mid-1960s with the exploits of Tom Patey and in July 1967 15 million people watched the climbing of the Old Man of Hoy live on BBC television. The idea was originally suggested by Patey who helped put together a team of six climbers who were filmed undertaking the ascent. This was described as connecting "an armchair audience with the elite of a sport subculture intent on conquering one of Britain's most spectacular geological treasures”. Following Patey's untimely death in 1970 development of the sport in Scotland largely ceased until the late 1980s and the arrival of Mick Fowler on the scene.
Definitions and etymology
Cleare (1974) defined stacks from a rock-climbing perspective using three criteria:
"A stack should be higher than it is wide in at least one of its planes.
Within reason there is no minimum height, except that if it is high enough to be worth climbing, then it's a stack.
A stack should have been formed by the action of the sea."
Mellor (2020) offers similar conditions: "a stack is an isolated cone, pinnacle or tower of rock entirely surrounded by the sea at high tide." He goes on to suggest that the difference between a stack and an island is that if the top is significantly wider in diameter than the height then it is an island, and that a stack should be at least high.
From a geological perspective a stack is a landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, formed by wave erosion. This definition excludes isolated steep-sided, rocky oceanic islets typically of volcanic origin, sometimes called "volcanic stacks". In the main listing below three different types of stack are identified:
Sea stacks
Outlying stacks, many of which are of volcanic origin
Wide stacks that fail Mellor's definition of height to summit diameter above but which either have "stack" in their name or are clearly a "tower of rock entirely surrounded by the sea".
There are numerous small pinnacles around the Scottish coast, many of them in remote locations. Such features are often not well-documented and the main list is thus confined to the larger and better known examples.
The word 'stack' is derived from the and is often rendered in the Norn of Shetland as stakk and in modern Gaelic as stac or the plural stacan.
Several descriptive names are used in more than one location. Examples include:
Gaada Stack, meaning "hole stack" and used to describe stacks that incorporate natural arches;
Moo Stack, of which there are at least four in Shetland;
Brough, which is cognate with meaning "fortification" and broch;
Castle, , is typically used for an isolated stack;
Ern, Norn for "eagle".
The name "stack" is however also sometimes appended to features other than sea stacks such as cliff-girt headlands and a number of such features are also listed below.
Distribution
Of the 275 stacks in Scotland identified by Mellor (2020) circa 110 are located around the coasts of Shetland of which 80 are around the coast of the Mainland. Most of the rest are found off the coasts elsewhere in the Highlands and Islands. He also lists 70 stacks in England, 10 in Wales and 55 off the island of Ireland.
Climbing history
The first stack climbers in Scotland were the residents of the now uninhabited islands of Hirta and Mingulay who were dependent on the bounty provided by seabirds. The first record of the recreational ascent of a sea stack in Scotland is likely that of Richard Manliffe Barrington, who climbed Stac Biorach in 1883. Sixteen years later Norman Heathcote and his sister Evelyn climbed Stac Lee. He wrote that Stac Lee was "not a difficult climb" and that two other women had also reached the summit.
Nonetheless, the main theme of the sport in the UK until the mid-1960s was "incidental stack climbing in pleasant and accessible locations". Yorkshireman Ian Clough ascended one of Macleod's Maidens on Skye in 1959 but the picture changed completely with the exploits of Tom Patey, (aka "Doctor Stack") whose day job was as a GP in Ullapool. He began with the Old Man of Stoer in 1966 and followed this up with ascents of Am Buachaille, the Old Man of Hoy and the Great Stac of Handa. After his death when descending The Maiden in 1970 "most Scottish stack explorations abruptly ceased".
There was then a hiatus of a dozen years as climbers began "putting up harder and harder lines on comfortable stacks until they felt strong enough to venture north again". In 1982 Arnis Strapcans put up a new route on the Old Man of Hoy. Two more routes were created on this stack in 1984 and with the arrival on the UK scene of Mick Fowler in 1985 events moved apace. He climbed the Old Man of Stoer in 1988 and numerous others over the next few years, "his most outrageous adventure" being on The Needle, another stack off the west coast of Hoy. His regular partners on these exploits were Andy Nisbett, Craig Jones and Jon Lincoln who made up the "famous four" completing, for example, the first ascent of The Runk in Shetland in May 1992.
Irishman Iain Miller made a solo second ascent of the Clett of Crura, South Ronaldsay in 1999 and since then has been involved in about 150 first ascents around Britain and Ireland. Nonetheless, in 2020 it was estimated that over 50 stacks around the British Isles have never been climbed.
In 2019 Red Széll became the first blind climber to ascend the three "Tom Patey stacks" of Am Buachaille, the Old Man of Stoer and the Old Man of Hoy. The 2020 film Climbing Blind documents the first blind lead of the Old Man of Hoy by Jesse Dufton. In 2024 Aden Thurlow, an 11-year-old boy, successfully lead climbs on Am Buachaillie and the Old Man of Stoer.
In 2023, by arrangement with the National Trust for Scotland, Stac Biorach was ascended again 130 years after Barrington became the first non-St Kildan to do so. Climber Robbie Phillips said it "was like walking in the footsteps, or climbing in the fingerprints, of the St Kildans. It's a testament to their bravery and mental fortitude; to climb onto that sea stack 70m above the raging Atlantic without even shoes is wild to imagine".
Main list
These are stacks which are well-known local landmarks greater than 15m in height, prominent rock climbing pinnacles, notable isolated stacks or are verified as being greater than in height.
Other stacks
This is a selection of the many other stacks in Scotland. All the below are included in Mellor (2020) except those with the symbol № which have been identified from Ordnance Survey maps and/or other sources as cited. According to Mellor there is no record of some of them having been climbed.
Sutherland
Stac na Faoileige, a 30m high stack off Handa
Am Bodach, 37m high by Cape Wrath
A’Chailleach, by Cape Wrath
Stac Thormaid, A' Mhòine
Geodha Brat East & West, A' Mhòine, 30 and 25m high respectively.
Puffin Stack, Melvich
Lady Bighouse Rock, 25m high
Caithness
Fort Rock by Scrabster
Clett Rock by Scrabster
The Stacks by Dunnet Head
Stack o' Brough, 35m high south of Wick №
South Stack, 44m high, south of Stack o' Brough №
Sinclair's Bay Stack
Stack of Ulbster
Roy Geo Stacks by Lybster
East coast
Cummingston Main Stack near the village of Cummingston in Moray
Logie Head Pinnacle near Cullen
Head of Garness near Macduff
The Tooth near MacDuff
The Molar near MacDuff
Dunbuy Rock, Cruden Bay
The Sugar Loaf, Cruden Bay
Berry’s Loup near Peterhead
Oldcastle near Peterhead
Long Slough Pinnacle south of Aberdeen
The Humpback south of Aberdeen
The Knapps Of Downies south of Portlethen
Brown Jewel near the village of Muchalls in Aberdeenshire №
May Craig, near Muchalls
Doonie Point, near Muchalls
Castle Rock Of Muchalls
Elephant Rock south of Montrose
Maiden Rock east of St Andrews
Wheat Stack, near Coldingham
The Souter, near Coldingham
Galloway
Burrow Head, 30m high near Isle of Whithorn
Monreith Stack
The Black Slab, Crammag Head, near Kirkmaiden
Witch Rock, Portpatrick, first ascended in 1899
Juniper Rock, northwest of Stranraer
Islay and Jura
American Monument Stacks, on the coast of The Oa, Islay
Impact Stack, near Loch Tarbert, Jura
Mull and environs
Castle Coefin, Lismore
Carsaig Stack, Mull
Stac Glas Bun Un Uisge, Mull
Croig, Mull
Quinish Poiunt, Mull
Stac an Aoineidh, Iona
Stac Leath, Iona
Stac Mhic Mhurchaid, Iona
Am Buchaille, Staffa
Dun Cruit, Lunga
Small Isles
The Spichean, Muck
Stac nam Faoileann, Rùm
Covenanter's Point Stack
Papadil Pinnacle, Rùm
Fist and Finger, Rùm
Harris Bay Stack, Rùm
An Coroghon, Canna
An t-Each, Canna
An Caraghon, Canna
Lorcail
Skye
Bob Bob Stack, Trotternish
Broken Needles, Trotternish
Stac Buidhe, Trotternish
Stac Laclainn, Trotternish
Stacan Gobblach, Trotternish
Rubha Hunish Stacks, Trotternish
Stack of Skudiburgh, Trotternish
Ru Idrigill Stack, Trotternish
Glen Lorgasdal Stacks, Duirinish
Stack a'Mheadhais, Minginish
Stac an Tuill, Minginish
Stac Suisnish, near Torrin
Fladda-chùain stacks
Outer Hebrides
Stac Shuardail, south of Knock, Lewis
Stac na Caoraich Lachduinne, Carloway
Stac a’Bhanain, Loch Roag
Stacan Neadacliv, near Uig
Stac na Berie, Uig
Stac Leathann, Uig
Stacageo, near Mealista
Haskeir Eagach
An Stac, off Eilean Leathan, Eriskay, although it is not clear there is a genuine sea stack here
Gèarum Beg, Mingulay
Gèarum Mòr, 51m high but arguably a precipitous islet rather than a true stack. In 1868 a wave washed over the top of it.
Na Gilleachan Ruadh at the northern tip of Mingulay, aka The Red Boy №
St Kilda
Sgarbhstac, Boreray from meaning "cormorant stack" №
Sgeir Mhòr, at the foot of the cliffs of Mullach Bi №
Sgeir Cùl an Rubha, on the western side of Dùn №
There is a small, unnamed stack east of Sgeir Cùl an Rubha and the headland of Giumachsgor №
Orkney
Stack of Kame, South Ronaldsay
Clett of Crura, South Ronaldsay
The Clett, South Rondaldsay
Stackabank, South Ronaldsay
Stack o'Roo, Birsay
Standard Rock, Birsay
Hemp Stack, south of Kirkwall
The Brough, Stronsay
Castle o' Burrian, Westray
Shetland islands
Fair Isle
Stacks of Wirrvie
Stacks of Skroo
Breiti Stack
Fogli Stack
Hundi Stack
West and East Burra
Stacks of Houssness at the south end of East Burra
Fugla Stack, a 33m high stack west of The Ward, West Burra
Clettnadel, a small stack just north of Fugla Stack
Kame of Riven Noup, a "wafer-like entity" north of Clettnadel. The name may mean "comb of the torn headland" and is the subject of a poem by Martha Morton from Brae.
Stack of Sandwick has an arch is and is located west of Bridge End, West Burra
Vaila
Gaada Stacks
Humla Stack
Papa Stour
Lyra Skerry Stack
Galti Stacks
The Foot
Snolda Stack №
Vementry and Muckle Roe
Swaba Stack, Vementry
Murbie Stacks, in the southwest of Muckle Roe
Riding Stack, north of Murbie Stacks
The Spindle, north of Riding Stack, off West Hill of Ham №
Da Kist, off Moo Ness №
Muckle Roe Stack, off Tame Holm
Swabi Stack 46m high in the northwest of Muckle Roe
Fetlar
Stack of Birrier
Stacks of Scambro
Furra Stacks
Stackan Longa
Bratta Stack
Stack of Grunnigeo
The Clett №
Yell
Ern Stack on the west coast is not a sea stack - see below.
Sweinna Stack, north of Scattalands on the west coast
Horns of the Roe, north of Sweinna Stack
Whale Geo Stacks, north of Horns of the Roe
Aastack, north of Whale Geo Stacks
Stacks of Stuis, at the entrance of Whale Firth
Aastack, south of Baagi Stack
Baagi Stack, south of Whilkie Stack
Whilkie Stack, by Gloup Holm
Eagle Stack, by Gloup Holm
Stack of the Horse, Burravoe
Unst
As with elsehere on Shetland the profusion of offshore islets and stacks create definitional problems. For example, The Greing north of Urda Stack is 53m high and is steeply sloping on one side and perpendicular cliffs on the other so not included. The name "stack" is also sometimes used for a headland, e.g. Sothers Stack, Hermaness or the nearby 55m high Humla Stack, which are included in Mellor's list of possible candidates or for rocky islets that come nowhere near meeting the definitions above e.g. Breiwick Stack, which is more of a skerry.
Lamba Stack, a small stack north of Belmont
Sinna Stack, west of Baltasound
Gamli Stack, north of Sinna Stack
Skate Stack, northwest of Gamli Stack
Stacks of Poindie, north of Skate Stack
Tonga Stack, off the Tonga headland west of Burrafirth
Longa Stacks, close to Tonga Stack
Neapna Stack, north of Longa Stacks, possibly exceeding 50m №
Tooa Stack, north of Neapna Stack №
Stackins-hocka, offshore from Tooa Stack.
Stackingro, off the west coast of Hermaness
Flodda Stack, north of Stackingro
Urda Stack, 35m high near the northern tip of Hermaness №
Burra Stack, with a natural arch and 44m high, north of Urda Stack
Wilna Stack, at the northern tip of Hermaness №
Wurs Stack, Hermaness, a small stack next to an unnamed skerry
Root Stacks, small stacks at the head of Burra Firth
Holey Kame, a 29m stack northeast of Burrafirth №
Tooral Stack, a 27m stack north of Holey Kame №
Hinda Stack, a 21m stack north of Tooral Stack №
Whida Stack, Brei Wick, northeast of RAF Saxa Vord - two stacks one of which reaches 34m №
Gerva Stacks, east of Brei Wick - two stacks one of which reaches 31m №
Cudda Stack, a small stack near the headland of North Coos, north of Nor Wick
Stack of Louin, east of Norwick
Stack of Russalore, west of Stack of Louin
North Stane, 28m high and east of the village of Saxa Vord №
Ship Stack, south of North Stane
Hagmark Stack, 21m high and south of Ship Stack
Muckle Flugga
Muckle Flugga comes equipped with a lighthouse but has had "many ascents"
Little Flugga reaches 31m №
Vesta Skerry reaches 48m №
Foula
Gaada Stack
Da Stacs o' Logat
Rippack Stack
Shetland mainland
Northmavine
Moo Stack, off Esha Ness
Stack of Sumra, Ronas Voe
Galti Stack, just off The Faither, Ronas Voe
Point of Quida-stack, Ronas Voe
Gruna Stack and Little Gruna Stacks, north of Ronas Voe
Galti Stack, east of Uyea
Out Shuna Stack, west of Uyea
Yellow Stack, 45m high at Point of Fethaland
Stuack, Point of Fethaland
Bark Stack, Point of Fethaland
Ramna Stacks, north of Point of Fethaland
Outer Stack, north of Ramna Stacks
Stack of Stavgeo, Yell Sound
Stack of the Rettuvie, Yell Sound
Stack of the Crubb, Yell Sound
The Castle, Yell Sound
Trolla Stack, Yell Sound
Nesting and South Mainland
Ura Stack, near the farm of Neap
Fru Stack, off Moul of Eswick
Hoo Stack, about a mile offshore from Moul of Eswick
Stacks of Vatsland, north of Gremista, Lerwick
Holm of Noss - unnamed stack c. 50m high.
Punds Stack off Ness of Trebister, south of Lerwick
Quarff Stack, by Quarff
Coall Head Stacks, south of Quarff
Stack of Okraquoy, near Falddabister
Stack of Billyageo, off No Ness, south of Mousa
Stack of the Brough, Boddam
Stack of Otter Geo, east of Sumburgh Airport
Broad Stack, west of Sumburgh Airport
Ripack Stack, close to Broad Stack
Landvillas, Wick of Shunni
Clocki Stack, northwest of Loch of Spiggie
Wester Wick
Moo Stack, south of Skeld
Berga Stack, Sil Wick №
Skerry of the Wick, 35m high №
Westwick Stacks, including Gro Stack in the bay of Wester Wick
Grossa Stack, Wester Wick №
The Cutter, a 31m ascent
Groni Stack, a 46m stack just north of The Cutter №
Burga Stacks, southwest of Culswick
Seli Stack, northwest of Culswick in Gruting Voe
Walls and Sandness
Lang Stack, a 50m stack northwest of Dales
West Stack, west of Mid Walls
Rusna Stacks, at the entrance to Vaila Sound
Litla Stack, in the Bay of Deepdale
West Burra Firth
Lang Stack, off Snarra Ness
Galta Stack
Swaaba Stack №
Turl Stack, east of Isle of West Burrafirth
St Magnus Bay (north)
Gordi Stack, south of Hillswick, which is 50m high
Oe Stack, south of the Isle of Nibon
Moo Stack, north of Eina Stack
Eina Stack, 30m high, northwest of Mavis Grind
Places called "stack" etc. that are not sea stacks
Stac Pollaidh is a hill in Sutherland
Erne Stack on Muckle Roe is "connected to the shore by a thin neck".
Ern Stack, Yell is a prominent feature with twin towers of white rock first climbed in 1980. It is also the last recorded nesting site of the Eurasian sea eagle in Shetland. However it is not sea-encircled.
The Old Man of Storr is an inland pinnacle on Skye.
Leac Mhina Stack (Ledge of Mina Stack) is a headland on the east coast of Hirta facing Mina Stack.
Stac a’ Langa is a narrow promontory at the foot of the cliffs of eastern Hirta.
Stac Dhomhnuill Chaim, Mangersta, is circa 50m high but joined to Lewis by a narrow spine of rock.
Stack of the Ship, which is attached to St Ninian's Isle by a "a knife-edged arête".
See also
Geography of Scotland
Notes
Footnotes
References
Dictionaries
Am Faclair Beag: An English – Scottish Gaelic dictionary incorporating Dwelly Faclair.com. Retrieved 27 March 2024.
John J. Graham's Shetland Dictionary. Shetlanddialect.org. Retrieved 25 March 2024.
Rocks
Islands of Scotland
Climbing areas of Scotland | List of sea stacks in Scotland | [
"Physics"
] | 4,351 | [
"Rocks",
"Physical objects",
"Matter"
] |
66,462,982 | https://en.wikipedia.org/wiki/WASP-75 | WASP-75 is a F-type main-sequence star about 980 light-years away. The star is much younger than the Sun at approximately . WASP-75 is similar to the Sun in its concentration of heavy elements.
Planetary system
In 2013 a transiting hot Jupiter planet b was detected on a tight, circular orbit, and the planet was confirmed in 2018. Its equilibrium temperature is .
References
Aquarius (constellation)
F-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
J22493256-1040320
BD-11 5929 | WASP-75 | [
"Astronomy"
] | 118 | [
"Constellations",
"Aquarius (constellation)"
] |
66,464,094 | https://en.wikipedia.org/wiki/Non-personal%20data | Non-Personal Data (NPD) is electronic data that does not contain any information that can be used to identify a natural person. Thus, it can either be data that has no personal information to begin with (such as weather data, stock prices, data from anonymous IoT sensors); or it is data that had personal data that was subsequently pseudoanonymized (for example, identifiable strings substituted with random strings) or anonymized (such as by irreversibly removing all personal data). NPD is part of the overall Data Governance Strategy of a region or country. While personal data are covered by Data Protection Legislation such as GDPR, other kinds of data would fall under the scope of NPD Regulation.
Importance of Non-personal Data
It has been pointed out that the future is data-driven. What this means is that much of the present innovation taking place in domains such as Machine Learning and Artificial Intelligence is fueled by data, which is needed for calibrating the complex models (comprising neural network-based as well as other kinds). The larger the volume, diversity and quality of the data, the higher is the quality of the model, leading to better predictions and explanations.
However, there is a flip-side to data availability. The newly-emerging awareness of privacy and the consequent need for powerful Data Protection Regulations (such as GDPR) makes it increasingly difficult or impossible to obtain data in the quantities required. This is a contradiction, and the only way out would be to remove all personal data from data sets (either by Data anonymization or Pseudonymization coupled with noise injection, at which point it becomes NPD.
Therefore, many innovation-friendly countries are coming out with regulatory regimes that would ensure that personal data is protected, while, at the same time, non-personal data can be extracted from personal data so that innovation is fostered. In other words, NPD 'unlocks' value that was locked away in data sets that have personally-identifiable information. It is expected that multiple NPD data sets will begin to be available on free or commercial basis from different providers once the regulations are in place.
Emerging Regulatory Frameworks
Non-Personal Data has significant uses that may be economic, social, political or security-related. Several countries and regions are in the process of regulating the use of NPD. In May 2019, the European Union operationalized its Regulation of the Free Flow of NPD. India announced a nine-member expert committee to make recommendations on the regulation of NPD in 2019, which published its first report in mid-2020. The report was opened for public comments, after which it was revised and published in December 2020.
Objectives of the Proposed Indian NPD Regulatory Framework
The following were the objectives of the proposed Indian regulation as per the revised report:
Sovereignty: India has rights over the data of India, its people and organisations.
Benefit India: Benefits of data must accrue to India and its people.
Benefits the world: Innovation, new models and algorithms for the world.
Privacy: Misuse, reidentification and harms must be prevented.
Simplicity: The regulations should be simple, digital and unambiguous.
Innovation and entrepreneurship: The data should be freely available for innovation and entrepreneurship in India.
Concerns
The major concern in the use of NPD is if there are techniques (statistical or AI-based) by which multiple data sets can be used to extract personally-identifiable data.
References
Data | Non-personal data | [
"Technology"
] | 706 | [
"Data management",
"Data"
] |
67,969,619 | https://en.wikipedia.org/wiki/Metyltetraprole | Metyltetraprole is a quinone outside inhibitor fungicide sold under the brand name Pavecto by its inventor, Sumitomo Chemical. It is the only tetrazolinone fungicide and the only one in the Fungicide Resistance Action Committee's subgroup 11A.
Development
Metyltetraprole was developed specifically to find an a.i. with the same mode of action (a QI) but with sufficiently different chemistry as to avoid "critical" QI resistance increasing around the world.
Target pathogens
Metyltetraprole is highly effective against Alternaria triticina.
Resistance
Developed because of increasing resistance to the main group of QIs. See Development above.
Cross-resistance
It does not suffer cross-resistance with the resistance against 11 conferred by the cytochrome b mutation G143A. Cross-resistance against F129L is unassessed.
Binding Mode
The structure of the tetrazolinone pharmacophore is very similar to the triazolone pharmacophore of an inhibitor developed by AgoEva, for which the binding mode has been elucidated in the structure deposited as 3L73 in the protein databank.
References
Fungicides
Tetrazoles
4-Chlorophenyl compounds
Pyrazoles | Metyltetraprole | [
"Biology"
] | 270 | [
"Fungicides",
"Biocides"
] |
67,971,710 | https://en.wikipedia.org/wiki/University%20of%20Toronto%20School%20of%20the%20Environment | The School of the Environment at the University of Toronto is a trans-disciplinary academic unit that acts as a hub for the study of the environment, sustainability and climate change, offering undergraduate and graduate programs, along with joint programs with many disciplinary departments across the University. According to Maclean's Magazine, the School ranks second for environmental science programs in Canada. The School's research focusses on knowledge mobilization on a range of environmental issues, addressing questions of how to integrate scientific knowledge with local, community-based, and Indigenous knowledge to address global environmental crises such as Climate Change. The School is also home to many activist student groups advocating for environmental action.
History
The current School of the Environment traces its history to three institutes at the University of Toronto. In 1959, the Great Lakes Institute was founded by Prof George Burwash Langford to study the impacts of pollution on the Great Lakes, and the geologist Roger E. Deane served as its first director. In 1971, under the directorship of physicist Don Misener, this became the Institute for Environmental Studies, and offered the University's first graduate programs in environmental studies. For many years, the Institute operated a field station at Baie Du Doré on the shores of Lake Huron, and a research ship, the HCMS Porte Dauphine. Independently, Innis College established an undergraduate Environmental Studies program in 1978, with courses taught by environmental activists such as NDP Leader Jack Layton and Ontario's first Environmental Commissioner, Eva Ligeti. A third unit, the undergraduate Division of the Environment was established in 1991 by the Faculty of Arts and Science, to administer degree programs in environmental studies.
In 2005, all three units were merged to form the Centre for Environment (CfE), under the directorship of the environmental philosopher Prof Ingrid Stefanovic. The Centre was then renamed as the School of the Environment in 2012. The inaugural director of the School was the atmospheric physicist, Professor Kim Strong.
Academics
Undergraduate programs
The School offers major and minor programs in both Environmental Studies and Environmental Science, as well as a range of interdisciplinary minor programs to be taken in conjunction with other majors across the Faculty of Arts and Science. It also offers a Certificate in Sustainability.
Graduate programs
The School offers two collaborative specialization programs, in Environmental Studies and in Environment and Health. These can be taken by graduate students enrolled in any program at the University of Toronto. In 2021, the School launched a 12-month thesis-based Masters of Environment and Sustainability.
Faculty
The School's 18 faculty members mainly hold joint appointments with a variety of discipline-based departments at the University of Toronto, spanning the physical sciences, social sciences, and humanities. The School also has 141 graduate faculty members who hold appointments in other departments, and contribute to teaching in the School's graduate programs.
Notable faculty include:
Miriam Diamond
Dianne Saxe
Kim Strong
Research
Research at the School spans a broad range of areas, including using the University campus itself as a Living Lab for sustainability, policies needed to tackle climate change, the study of persistent toxins in the environment and their impact on human health, and the role of cycling in urban transportation policy.
References
External links
University of Toronto
University departments in Canada
Environmental organizations based in Canada
Environmental research institutes
Environmental science
Environmental studies institutions in Canada | University of Toronto School of the Environment | [
"Environmental_science"
] | 656 | [
"nan",
"Environmental research institutes",
"Environmental research"
] |
67,972,165 | https://en.wikipedia.org/wiki/Colin%20Ratledge | Colin Ratledge (born 9 October 1936) is a British biochemist who was Professor of Microbial Biochemistry at the University of Hull from 1983 to 2004.
He was educated at Bury High School, and graduated from University of Manchester with a BSc in 1957 and a PhD in 1962. He joined the University of Hull as a lecturer in 1967 and was head of the Department of Biochemistry there from 1986 to 1988.
He was editor of Biotechnology Letters from 1996 to 2017. He received the Stephen Chang Award from the American Oil Chemists' Society in 2011. In 2015 the Colin Ratledge Center for Microbial Lipids opened at Shandong University of Technology. He was awarded an honorary doctorate from Ben-Gurion University of the Negev in 2018.
He has an h-index of 58 according to Semantic Scholar.
References
1936 births
Living people
Alumni of the University of Manchester
Academics of the University of Hull
Fellows of the Royal Society of Chemistry
Fellows of the Royal Society of Biology
British academic journal editors | Colin Ratledge | [
"Chemistry"
] | 200 | [
"Biochemistry stubs",
"Biochemists",
"Biochemist stubs"
] |
67,973,010 | https://en.wikipedia.org/wiki/Praseodymium%28III%29%20oxalate | Praseodymium(III) oxalate is an inorganic compound, a salt of praseodymium metal and oxalic acid, with the chemical formula C6O12Pr2. The compound forms light green crystals that are insoluble in water. It also forms crystalline hydrates.
Preparation
Praseodymium(III) oxalate can be prepared from the reaction of soluble praseodymium salts with oxalic acid:
Properties
Praseodymium(III) oxalate forms crystalline hydrates (light green crystals): Pr2(C2O4)3•10H2O. The crystalline hydrate decomposes stepwise when heated:
Uses
Praseodymium(III) oxalate is used as an intermediate product in the synthesis of praseodymium. It is also applied to colour some glasses and enamels. If mixed with certain other materials, the compound paints glass intense yellow.
References
Inorganic compounds
Praseodymium(III) compounds
Oxalates | Praseodymium(III) oxalate | [
"Chemistry"
] | 213 | [
"Inorganic compounds"
] |
67,973,838 | https://en.wikipedia.org/wiki/KICTANet | KICTANet Trust is a multistakeholder think tank for Information and communications technology policy formulation whose work spans Stakeholder engagement, capacity building, research, and policy advocacy. The network was initially designed to welcome multistakeholder participation due to the ‘perceived strength and effectiveness in joint collaborative policy advocacy activities, which would be based on pooling skills and resources,’ as opposed to wasting resources in ‘competing, overlapping advocacy’. Its operating slogan was, ‘let’s talk, though we may not agree’. Tina James, who worked with CATIA when it supported the creation of KICTANet, points out: ‘the creation of KICTANet was just the right process at the right time.'
With government and other stakeholders apparently relying on it, KICTANet therefore continued after the ICT policy was adopted, leading to ‘quite a lot of successes’ like the 2010 Kenya ICT Master Plan, as well as the regulatory approval of M-Pesa and Voice over Internet Protocol (VOIP) services in the country. It also, for instance, participated in discussions that led to the drafting and passing of the National Cybersecurity Strategy (2014) and coordinated public participation in consultations like the 2014 African Union Convention on Cybersecurity. By managing a website and mailing list with over 1000 participants from diverse stakeholder groups, it has been described as ‘the biggest convener of ICT stakeholders in Kenya’.
Over the years, KICTAnet has contributed to the development of various ICT laws in Kenya, among them the Kenya Information & Communications Act 2013, Kenya Data Protection Act 2019, Kenya Computer Misuse & Cybercrimes Act 2018, Kenya ICT Policy 2006, Kenya ICT Policy 2019, and the Kenya Data Protection Policy 2019. KICTANet's work has accelerated the uptake of ICTs in the African region and contributed to the achievement of the Sustainable Development Goals.
KICTANet has played a major advocacy role in the liberalization of the voice of the internet, and such other processes as the Freedom of Information Bills, the Independent Communications Commission of Kenya Bill, and the Media Council Bill.
KICTANet has been the convener of the Kenya IGF and the East African IGF. It was also one of the organizers of the global IGF held in Nairobi, Kenya in 2011.
Structure
In 2016, KICTANet was registered as a Trust governed by a board of Trustees which includes a convenor (Chief Executive Officer), a chair, a treasurer, and a secretary. The current convenor and Chief Executive Officer is Ms Grace Githaiga.
References
Information and communications technology
Think tanks based in Kenya | KICTANet | [
"Technology"
] | 536 | [
"Information and communications technology"
] |
67,974,589 | https://en.wikipedia.org/wiki/Indian%20burn | An Indian burn, also known as a snake bite or Chinese burn in the UK and Australia, is a pain-inducing prank, where the prankster grabs onto the victim's forearm or wrist, and starts turning the skin away from themselves with one hand, and with another hand towards themselves, causing an unpleasant burning sensation to the skin. The prank is popular in a school setting.
Terminology
The prank is known by various different names in the United States, such as Indian sunburn or Indian rug burn, and also as Chinese wrist burn, and as the snake bite. In countries such as the United Kingdom and Australia, it is known as a Chinese burn. In Mexico, it is known as an . In Sweden, it is called ("a thousand needles"). In Netherlands, it is called ("barbed wire") and in Germany it is called ("stinging nettle"). In Afrikaans it is called a "donkie byt" which translates to "donkey bite."
Variations
A variation of the prank can be done with a yarn that can be rubbed against the skin in a similar manner when starting fire in a small and dried haystack.
Criticism
Some Native Americans disapprove the use of the term Indian burn, including other vocabulary starting with the prefix "Indian-", such as Indian corn, Indian summer and Indian giver, among others.
Statistics
According to a poll carried out in the United Kingdom, with a sample size of 1,844 adults, 27% recalled receiving Indian burns in secondary school.
See also
List of practical joke topics
Wedgie
References
Abuse
Harassment and bullying
Pain
Practical jokes
Suffering
Native American topics | Indian burn | [
"Biology"
] | 335 | [
"Behavior",
"Abuse",
"Harassment and bullying",
"Aggression",
"Human behavior"
] |
67,975,103 | https://en.wikipedia.org/wiki/Copper%28II%29%20oxalate | Copper(II) oxalate are inorganic compounds with the chemical formula . The value of x can be 0, 0.44, and 1. Two of these species are found as secondary minerals (degradation of minerals), whewellite (monohydrate) and moolooite (0.44 hydrate). The anhydrous compound has been characterized by X-ray crystallography. Many transition metal oxalate complexes are known.
Copper(II) monooxalates are practically insoluble in all solvents. They are coordination polymers.
Synthesis
Copper(II) oxalate can be produced by precipitation from acidified aqueous copper(II) salts and oxalic acid.
Reactions
Upon heating to 130 °C, the hydrated copper(II) oxalates convert to the anhydrous cupric oxalate. Further heating at higher temperatures under an atmosphere of hydrogen gives copper metal, suitable as a reagent.
The hydrates bind Lewis bases.
Hydrated copper(II) oxalate reacts with alkali metal oxalates and ammonium oxalate to give bis(oxalato)cuprate:
Uses
Copper oxalate is used as a catalyst for organic reactions, as a stabilizer for acetylated polyformaldehyde.
Related compounds
Cuprous oxalates.
References
Inorganic compounds
Copper compounds
Oxalates | Copper(II) oxalate | [
"Chemistry"
] | 286 | [
"Inorganic compounds"
] |
67,975,444 | https://en.wikipedia.org/wiki/List%20of%20SonyLIV%20original%20programming | SonyLIV is an Indian subscription video on-demand over-the-top Internet streaming platform that has distributed a number of original streaming television shows, including original series, specials and films.
SonyLIV original productions also include licensing or co-producing content from international broadcasters for exclusive broadcast in India and other territories. which is also branded as SonyLIV original content.
LIV originals
These include the TV shows, Mini-Series and films that are partly or fully distributed by SonyLIV, some of which are also produced and co-produced with other digital labs and labelled as an original content.
TV shows
Films
Exclusive programming
These include the exclusive digital streaming rights of the TV shows and films sold to SonyLIV by their respective production companies.
TV shows
Documentaries
Films
Exclusive international distribution
TV shows
See also
Sony Pictures Networks India
List of Amazon India originals
List of Hotstar original films
List of Disney+ Hotstar original programming
List of Netflix India originals
List of ZEE5 original programming
JioCinema
References
External links
List of Sonyliv Originals
Internet streaming services
Lists of television series by network
Lists of television series by streaming service
Video on demand services
Internet-related lists | List of SonyLIV original programming | [
"Technology"
] | 232 | [
"Computing-related lists",
"Internet-related lists"
] |
67,976,248 | https://en.wikipedia.org/wiki/HD%2033266 | HD 33266 (HR 1675) is a solitary star in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 6.17, making it faintly visible to the naked eye. Located 481 light years away, it is approaching the Sun with a heliocentric radial velocity of .
HD 33266 is an A-type star with 2.45 times the mass of the Sun and 3.14 times the radius of the Sun. It shines at from its photosphere at an effective temperature of 8,952 K, giving it a white glow. Due to HD 33266 being an Am star, it spins slowly with a projected rotational velocity of at an age of 340 million years. Its metallicity − elements heavier than helium − is at solar level.
Note
References
Camelopardalis
A-type stars
33266
024313
1675
Durchmusterung objects | HD 33266 | [
"Astronomy"
] | 185 | [
"Camelopardalis",
"Constellations"
] |
67,976,870 | https://en.wikipedia.org/wiki/Onyema%20Ogbuagu | Onyema Eberechukwu Ogbuagu (born June 20, 1978) is an American-born infectious diseases physician, educator, researcher, and clinical trial investigator, who was raised and educated in Nigeria. He is an associate professor at Yale School of Medicine in New Haven, CT and is the director of the Yale AIDS Program clinical trials unit. His research contributions have focused on HIV/AIDS prevention and COVID-19 vaccination and treatment clinical trials. He switched his focus at the beginning of the 2019 COVID pandemic and participated as a principal investigator (PI) on the Pfizer-BioNtech COVID-19 vaccine trials and the Remdesivir SIMPLE trial in 2020 and 2021. In pursuit of his global health component of his career, Ogbuagu also supports postgraduate physician medical education programs in low and middle income countries in sub-Saharan Africa in Rwanda (2013–2018) and Liberia (2017 to date) as well as HIV treatment programs in Liberia (2018 to date).
In his role as public health educator, he has worked to increase public understanding of mRNA vaccines. Ogbuagu has also worked to decrease vaccine hesitancy. He has been a co-author on 43 scholarly articles, according to the National Library of Medicine. According to Google Scholar, one article he co-authored on Remdesivir and its use for Covid that appeared in JAMA was cited 504 times. Ogbuagu was selected as the commencement speaker for Yale School of Medicine's class of 2021.
Early life and education
Onyema Ogbuagu and an identical twin brother, Chibuzo Ogbuagu II, were born to Chibuzo and Stella Ogbuagu. Nigerian doctoral students attending Yale University and University of Pennsylvania, respectively, when their twins were born. The couple had graduated in the 1974 from the University of Nigeria, Nsukka, where Stella was valedictorian. The family returned to Nigeria when Onyema and Chibuzo were five years old.
Before their recent retirement, Onyema's father was vice-chancellor of Abia State University, Nigeria, and his mother was a professor of sociology and a former deputy vice-chancellor of the same institution.
Onyema Ogbuagu attended Auntie Margaret International Primary School in Calabar, and obtained his secondary education at Federal Government College, Okigwe, Imo State, Nigeria (1988 to1994), graduating at 15. He graduated from the College of Medical Sciences, University of Calabar, Nigeria in 2014. He completed his medical internship at the Ebonyi State University Teaching Hospital in Abakaliki, Nigeria. He then returned to the United States, where he interned at the Elmhurst campus of Icahn School of Medicine at Mount Sinai. Ogbuagu completed his residency and chief residency at Mount Sinai in 2010.
Ogbuagu completed an infectious diseases fellowship at Yale School of Medicine in 2012 and assumed a faculty position as an assistant professor in the same year. Currently, he is an associate professor of medicine in the Department of Internal Medicine, Section of Infectious Diseases.
Personal life
Ogbuagu is married to Grace Igiraneza Ogbuagu. She is a nephrologist and member of the International Nephrology Society.
Career
Ogbuagu is an HIV/AIDS physician and leads a clinical trials program at Yale that conducts research on infectious diseases. He has been the principal investigator on pharmacokinetic, phase 2 and 3 safety and efficacy trials of novel antiviral compounds for HIV in addition to his recent work on COVID-19 vaccinations and therapeutics.
He is a clinician at Yale Medicine, the medical practice of Yale School of Medicine, and sees patients at Yale New Haven Hospital's Nathan Smith Clinic.
Ogbuagu trains physicians in Liberia and Rwanda. He has been a visiting professor to the National University of Rwanda since 2012, where he mentors medical residents and junior faculty and assists them in conducting clinical research projects that have local importance such as HIV/AIDS and antimicrobial resistance. In Liberia, he is program director of Yale's Office of Global Health's efforts to support Internal Medicine residency training. He trained the first infectious disease fellow in Liberia.
COVID-19 and HIV/AIDS research
At the beginning of the COVID-19 pandemic, Ogbuagu shifted his focus from AIDS/HIV research and patient care to lead vaccine trials for COVID-19 at the Yale Center for Clinical Investigation where he was a PI on the Pfizer-BioNtech COVID-19 mRNA vaccine trial arms at Yale in adults as well as the pediatric studies for12-15 year-olds and 6 month to 11 year olds. The adult Pfizer BioNtech vaccine received emergency use authorization in the United States from the Food and Drug Administration (FDA) in 2020 and full FDA approval in 2021. There were approximately 150 sites for the Pfizer BioNtech mRNA trial, each led by a principal investigator.
Ogbuagu was also a PI for the second Phase 2b Sanofi-Glaxo Smith Klein novel COVID-19 vaccination candidate. He was also the Yale site PI for COVID treatment studies including the Remdesivir SIMPLE moderate and Severe trials.
Previous to this clinical trial work, he researched pharmacokinetic, phase 2 and 3 safety and efficacy trials of novel antiviral compounds (HIV), and conducted HIV prevention trials.
Awards
In 2015, Ogbuagu elected as a Fellow of the American College of Physicians. In 2017, He received the Steve Huot Faculty Award for Dedication and Excellence from Yale School of Medicine's Internal Medicine Primary Care Program.
In 2014 and in 2019, he received the Gerald H. Friedland prize for outstanding international research presentation by the Connecticut Infectious Diseases Society. On February 18, 2020, he also received an award from the Rwanda College of Physicians for his contribution in the fight against infectious diseases.
Publications
Tuan J, Spichler-Moffarah A, Ogbuagu O. A new positive SARS-CoV-2 test months after severe COVID-19 illness: reinfection or intermittent viral shedding? BMJ Case Rep. 2021 Feb 4;14(2):e240531. doi: 10.1136/bcr-2020-240531. PMID 33542020; PMCID: PMC8098910.
Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, Perez JL, Pérez Marc G, Moreira ED, Zerbini C, Bailey R, Swanson KA, Roychoudhury S, Koury K, Li P, Kalina WV, Cooper D, Frenck RW Jr, Hammitt LL, Türeci Ö, Nell H, Schaefer A, Ünal S, Tresnan DB, Mather S, Dormitzer PR, Şahin U, Jansen KU, Gruber WC; C4591001 Clinical Trial Group. Safety and Efficacy of the BNT162b2 mRNA COVID-19 Vaccine. N Engl J Med. 2020 Dec 31;383(27):2603-2615. doi: 10.1056/NEJMoa2034577. Epub 2020 Dec 10. PMID 33301246; PMCID: PMC7745181.
Edelman EJ, Moore BA, Calabrese SK, Berkenblit G, Cunningham CO, Ogbuagu O, Patel VV, Phillips KA, Tetrault JM, Shah M, Blackstock O. Preferences for implementation of HIV pre-exposure prophylaxis (PrEP): Results from a survey of primary care providers. Prev Med Rep. 2019 Oct 21;17:101012. doi: 10.1016/j.pmedr.2019.101012. PMID 31890474; PMCID: PMC6926349.
Spinner CD, Gottlieb RL, Criner GJ, Arribas López JR, Cattelan AM, Soriano Viladomiu A, Ogbuagu O, Malhotra P, Mullane KM, Castagna A, Chai LYA, Roestenberg M, Tsang OTY, Bernasconi E, Le Turnier P, Chang SC, SenGupta D, Hyland RH, Osinusi AO, Cao H, Blair C, Wang H, Gaggar A, Brainard DM, McPhail MJ, Bhagani S, Ahn MY, Sanyal AJ, Huhn G, Marty FM; GS-US-540-5774 Investigators. Effect of Remdesivir vs Standard Care on Clinical Status at 11 Days in Patients With Moderate COVID-19: A Randomized Clinical Trial. JAMA. 2020 Sep 15;324(11):1048-1057. doi: 10.1001/jama.2020.16349. PMID 32821939; PMCID: PMC7442954.
Ogbuagu O, Marshall BDL, Tiberio P, Ogunbajo A, Barakat L, Montgomery M, Almonte A, Wray T, Williams EC, Edelman EJ, Chan PA. Prevalence and Correlates of Unhealthy Alcohol and Drug Use Among Men Who Have Sex with Men Prescribed HIV Pre-exposure Prophylaxis in Real-World Clinical Settings. AIDS Behav. 2019 Jan;23(1):190-200. doi: 10.1007/s10461-018-2260-9. PMID 30145707; PMCID: PMC7020905.
Rutledge R, Madden L, Ogbuagu O, Meyer JP. HIV Risk perception and eligibility for pre-exposure prophylaxis in women involved in the criminal justice system. AIDS Care. 2018 Oct;30(10):1282-1289. doi: 10.1080/09540121.2018.1447079. Epub 2018 Mar 11. PMID 29527934; PMCID: PMC6085161.
Kambutse I, Igiraneza G, Ogbuagu O. Perceptions of HIV transmission and pre-exposure prophylaxis among health care workers and community members in Rwanda. PLoS One. 2018 Nov 26;13(11):e0207650. doi: 10.1371/journal.pone.0207650. Erratum in: PLoS One. 2019 Feb 22;14(2):e0212933. PMID 30475841; PMCID: PMC6261021.
References
1978 births
Living people
21st-century African-American scientists
21st-century American physicians
Fellows of the American College of Physicians
Yale School of Medicine faculty
University of Calabar alumni
American infectious disease physicians
American people of Nigerian descent
Vaccinologists
21st-century African-American academics
21st-century American academics | Onyema Ogbuagu | [
"Biology"
] | 2,337 | [
"Vaccination",
"Vaccinologists"
] |
67,977,408 | https://en.wikipedia.org/wiki/Transition%20metal%20oxalate%20complex | Transition metal oxalate complexes are coordination complexes with oxalate (C2O42−) ligands. Some are useful commercially, but the topic has attracted regular scholarly scrutiny. Oxalate (C2O42-) is a kind of dicarboxylate ligand. As a small, symmetrical dinegative ion, oxalate commonly forms five-membered MO2C2 chelate rings. Mixed ligand complexes are known, e.g., [Co(C2O4)(NH3)4]κ+.
Examples
Homoleptic complexes
Homoleptic oxalato complexes are common, e.g., those with the formula [M(κ2-C2O4)3]n-: M = V(III), Mn(III), Cr(III), Tc(IV), Fe(III), Ru(III), Co(III), Rh(III), Ir(III). These anions are chiral (D3 symmetry), and some have been resolved into their component enantiomers. Some early metals form tetrakis complexes of the type [M(κ2-C2O4)4]n- M = Nb(V), Zr(IV), Hf(IV), Ta(V),
The Δ and Λ enantiomorphs of have been separated.
Oxalate is often a bridging ligand forming bi- and polynuclear complexes with (κ2,κ'2-C2O4)M2 cores. Illustrative binuclear complexes are [M2(C2O4)5]2- M = Fe(II) and Cr(III)
Mixed ligand complexes
Whereas homoleptic complexes are easier to describe, far more abundant are complexes with oxalate and other ligands. Many metals form polynuclear complexes with oxalate and water. In ferric oxalate, , one oxalate is bonded through all four oxygen atoms and another oxalate binds through only two oxygen atoms, in both cases bridging. "Durrant's salt" contains the anionic complex .
Reactions and applications
Metal oxalate complexes are photoactive, degrading with loss of carbon dioxide. This reaction is the basis of the technique called actinometry. Ferrioxalate undergoes photoreduction. The iron centre is reduced (gains an electron) from the +3 to the +2 oxidation state, while an oxalate ion is oxidised to carbon dioxide:
2 []3− + hν → 2 []2− + 2 +
The redox reaction has been used to access unusual complexes. UV-irradiation of Pt(C2O4)(PPh3)2 gives derivatives of Pt0(PPh3)2.
Metal oxalates with the stoichiometry 1:1 are often insoluble. This fact provides a way to separate metal ions from solutions, including extract of ores. Combustion of metal oxalates gives metal oxides.
Natural occurrence
The minerals moolooite and antipinite are examples of naturally occurring copper oxalates. They arise from the weathering of other copper ores. A few other oxalate-containing minerals are known.
See also
Transition metal carboxylate complex
Oxalatonickelate
References
Ligands
Oxalato complexes | Transition metal oxalate complex | [
"Chemistry"
] | 706 | [
"Ligands",
"Coordination chemistry"
] |
67,977,435 | https://en.wikipedia.org/wiki/4-PrO-DMT | 4-Propionoxy-N,N-dimethyltryptamine (4-PrO-DMT, or O-Propionylpsilocin) is a synthetic psychedelic drug from the tryptamine family with psychedelic effects, and is believed to act as a prodrug for psilocin. It produces a head-twitch response in mice. It has been sold online as a designer drug since May 2019. It was first identified as a new psychoactive substance in Sweden, in July 2019. A number of related derivatives have been synthesized as prodrugs of psilocin for medical applications.
Recreational use
Dosage
4-PrO-DMT is reported to be orally psychoactive substance and while dosage effects have been studied in mice, its effects and longevity on humans has not been formally studied. The effects of 4-PrO-DMT are similar to those of psilocin (4-HO-DMT), as it acts as a prodrug.
Pharmacology
Pharmacodynamics
4-PrO-DMT is theorized to be a serotonergic psychedelic, and is partial agonist of the 5-HT1D, 5-HT1B and 5-HT1A serotonin receptors.
Toxicity
Very little data about the toxicity or pharmacology of 4-PrO-DMT is known. Its chemical structure and pharmacological activity are similar to psilacetin, a compound which isn't associated with compulsive use or physical dependence. However, due to lack of research and data, it cannot be definitively concluded that its pharmacological actions in the human body do not differ from those of psilacetin. To date, there have been no reported deaths from 4-PrO-DMT.
See also
4-HO-DMT
4-AcO-DMT
5-MeO-DMT
FT-104
Psilocybin
References
Psychedelic tryptamines
Dimethylamino compounds
Entheogens
Serotonin receptor agonists
Prodrugs
Designer drugs
Esters | 4-PrO-DMT | [
"Chemistry"
] | 433 | [
"Esters",
"Functional groups",
"Prodrugs",
"Organic compounds",
"Chemicals in medicine"
] |
67,978,181 | https://en.wikipedia.org/wiki/First%20Call%20Resolution | First Call Resolution or First Contact Resolution (FCR) is a metric that measures a call center's performance for resolving customer interactions on the first call or contact, eliminating the need for follow-up contacts. FCR is one of the most-watched metrics and considered the most important call center industry metric. Ideally, the FCR definition means no repeat calls or contacts are required from the initial call or contact reason from a customer perspective.
The difference between First Call Resolution and First Contact Resolution is the contact channels measured for FCR (e.g., interactive voice response, chat, email, website, call center). The First Call Resolution metric name measures FCR for a call center. The First Contact Resolution metric name measures FCR for any contact channel.
There are numerous external and internal methods for measuring FCR. Internal methods measuring operational performance include agent logging, speech analytics, quality monitoring, reopened issues, and counting repeat call volume. External methods measuring FCR and customer satisfaction include post-call surveys. "No Repeat Calls" in a given timeframe and "Post-Call Survey" FCR measurement methods have not only been used for over two decades but continue to be the most popular methods used by call centers for measuring FCR.
Ideally, FCR is determined based on the perspective of the customer. This is because the customer's opinion is what matters the most as the customer is the only one who is going to know whether their issue was resolved.
Overview
The origins of FCR started in an inbound call center. Originally, the FCR rate was measured only on voice calls but has expanded to all contact channels (e.g., email, interactive voice response, chat, website, call center, social media). The FCR metric has been used in the call center industry for over 25 years and continues to be a prevalent call center metric.
Nearly a decade ago, the start of customer relationship management ended the old days of "measure everything that moves". Call centers have a wide range of available statistics and data to analyze customer experience (CX). Top call centers realize that to be successful, they must find the metrics that truly impact CX and reveal the key insights. Research suggests that no single key performance indicator (KPI) has a bigger impact on customer satisfaction than FCR; customer satisfaction drops an average of 15% (top box response) with each callback a customer must make to a call center.
The call center industry average for FCR using the external FCR measurement method of a post-call survey is 70% which means that 30% of customers must call back about the same call reason for the average call center. An FCR rate considered good is 70% to 75%. FCR rates can also vary by industry, call complexity, and segment. Research shows that 60% of companies measuring FCR for 1+ years report a 1% to 30% improvement in their performance.
FCR is an indicator of improving customer journey metrics (e.g., customer satisfaction), operating cost metrics (e.g., cost per call for resolution), and business outcome metrics (e.g., Net Promoter Score®, Net Retention Index). For example, research shows for every 1% improvement in FCR, there is a 1% improvement in customer satisfaction. Research also shows for every 1% improvement in FCR increases transactional Net Promoter Score® by 1.4 points. When FCR performance is low or high, so are the performances of customer satisfaction and referrals and a reduction in cost and customer defections.
Research shows that majority (93%) of customers expect their call to be resolved on the first call. Why does FCR stand out with all the possible ways of viewing call center performance? It gives insight into a call center interaction through the customers' perspective. Most people do not enjoy making repeated calls or contacts to address issues because they want to resolve their calls on the first call.
There are a number of challenges in measuring first call resolution. The challenge still exists today as to how to define and measure FCR accurately, effectively, and efficiently. Since defining and measuring FCR is open for interpretation, there is no consistent process to measure this critically important KPI. Some call centers report 90 to 95 percent FCR rates, yet it raises a red flag when FCR is that high. Perhaps the calls being resolved should not be handled by phone initially, as the customer's call could have been resolved using a self-serve contact channel.
Criticism
Many call center leaders consider the FCR metric difficult to measure because it is complex. There is no internal FCR measurement industry standard, which hinders the accuracy of the FCR measurement and the benchmarking of FCR against other call centers. Internal FCR measurement uses no repeat call in a given time frame criteria for determining an organization’s FCR rate. This approach can overstate the FCR rate by 10% to 20% higher than the external FCR measurement (e.g., post-call survey).
Even though call center leaders have identified FCR as a critical KPI, there is some question about what exactly constitutes a "resolved call." Some call centers consider a call resolved if the agent didn't need to transfer it. Other call centers determine if a call is resolved if there is no follow-up work needed by the customer after the call. Internal FCR is determined based on whether the customer called back for the same issue within 1 to 30 days. Determining the appropriate callback time can be difficult, and as a result, there is no industry standard for internal FCR measurement, making the FCR rate less accurate for benchmarking against other call centers.
References
Customer relationship management
Metrics
Customer service | First Call Resolution | [
"Mathematics"
] | 1,178 | [
"Quantity",
"Metrics"
] |
67,978,504 | https://en.wikipedia.org/wiki/Nori%20%28company%29 | Nori Inc. was a technology company based in Seattle, Washington, that closed in 2024. The company's main business is a carbon marketplace focused on soil-carbon sequestration and pays farmers who adopt regenerative agriculture practices which may contribute to carbon sequestration.
History and funding
Nori was founded in 2017 by Paul Gambill.
In 2018, Nori raised $145,548 on Republic's crowdfunding platform when its CEO, Gambill pitched Nori on an episode of Meet the Drapers, starring venture capitalist Tim Draper and his family.
In 2020, Nori raised $4 million from several investors.
In February, 2022 Nori raised $7 million in a Series A round led by M13 and Toyota Ventures.
In April 2023, Nori laid off 10 employees due to "changing market conditions." Several months later, the company hired Matt Trudeau as its new CEO and raised an additional $6.25 million in funding. Gambill then transitioned to the title of Chief Product Officer and ended his tenure with the company in March 2024, although staying as a member of its board.
Products and services
Nori has created a platform where carbon removal suppliers can get paid by carbon removal buyers. Nori specifically focuses on the growth of financial incentives and the supply of carbon removal offsets, not reduction or avoidance offsets.
Nori sells the Regenerative Tonne™ (formerly "Nori Carbon Removal Tonnes” or “NRTs”) on its trading platform to represent one tonne of carbon dioxide () that has been removed from the atmosphere into for a minimum of 10 years. Nori's RTs are generated from agricultural projects that can store carbon dioxide in soil as of April 2021. These soil projects are broadly called regenerative agriculture practices. Nori is developing a financial instrument to assist growers in enhancing carbon dioxide sequestration in their soils, with potential benefits including climate change mitigation, drought tolerance, reduced surface runoff pollution, and improved soil health.
In December 2023, Nori launched the Net Zero Tonne™, a blended credit that mixes soil carbon sequestration with durable removal like direct air capture.
Early adopters
In early 2020, Maryland farmer Trey Hill became the first seller in Nori's marketplace. He was paid over $115,000 for practices that, over the preceding few years, had sequestered over 8,000 tons of carbon in the soil. Buyers included Shopify Inc., Arizona State University, and individuals looking to remove carbon.
In November 2020, Iowa farmer Kelly Garrett sold 5,000 carbon removals through Nori's carbon removal marketplace platform and Locus Agricultural Solutions. The buyer of the carbon credits was Shopify Inc, who used the carbon removal credits to help negate emissions from transporting goods sold on the Black Friday/Cyber Monday weekend.
References
Carbon capture and storage
Sustainable agriculture
Organizations based in Washington (state) | Nori (company) | [
"Engineering"
] | 601 | [
"Geoengineering",
"Carbon capture and storage"
] |
67,979,114 | https://en.wikipedia.org/wiki/Christian%20Happi | Christian Happi is a Professor of Molecular Biology and Genomics in the Department of Biological Sciences and the Director of the African Centre of Excellence for Genomics of Infectious Diseases, both at Redeemer’s University. He is known for leading the team of scientists that used genomic sequencing to identify a single point of infection from an animal reservoir to a human in the Ebola outbreak in West Africa. His research focus is on infectious diseases, including malaria, Lassa fever, Ebola virus disease, HIV, and SARS-CoV-2.
Early life and education
Professor Happi was born in Sangmélima, Cameroon, fourth of eight children. He graduated from the University of Yaounde, Cameroon, in 1993 with a Bachelor of Science in Biochemistry with honors. He obtained his PhD from the University of Ibadan, Nigeria, in 2000 and went on to Harvard University as a Postdoctoral Fellow from 2000 to 2003. He subsequently worked at Harvard University as a Research Scientist from 2004 to 2007. He became an adjunct Professor at Harvard University School of Public Health between 2007–2011.
Research and career
Happi has led several public health sequencing efforts in Africa. His team rapidly sequenced Nigeria’s first Ebola case, and up to 20 cases a day throughout the outbreak. He sequenced Lassa fever strains in a 2018 outbreak, helping researchers to conclude that the Lassa fever outbreak was due to spread by rats, rather than a mutation which had made it easier to spread between people. He also played significant roles in genomics efforts such as 1000 Genomes Project and H3Africa. More recently he has led efforts for SARS-CoV-2 in Nigeria.
In 2020 he gave a TED talk called A virus detection network to stop the next pandemic.
Awards and honors
His awards and honors include;
2020 Bailey K. Ashford Medal
2019 HUGO African Prize
2011 & 2012, ExxonMobil Malaria Leadership Fellow
2011, Merle A. Sande Health Leadership Award
2010, Scholarship to Second Annual Course on Point-of-Care Diagnostics for Global Health, University of Washington Seattle (USA)
2010, Boroughs Wellcome and Bill & Melinda Gates Awards, Genome Epidemiology Meeting (GEM), Wellcome Trust Conference Centre, Hinxton (UK)
2009 – 2014, Wellcome Trust Research Grant Award
2009, European Union-Developing Countries Clinical Trials Partnership (EDCTP) Senior Research Fellowship Award (The Hague, Netherlands)
2008, Chair, Scientific Advisory Committee Africa Health Research Organization (AHRO) (Ghana)
2007, Turner Biosciences Research Award (USA)
2005 – 2008, Plasmodium falciparum Pathogenesis and Applied Genomics Research Award, World Bank/UNICEF/WHO/TDR
2004, Chair, Molecular Parasitology session, 50th Annual Meeting and Anniversary of the ASTMH, Philadelphia, Pennsylvania, USA
2003 – 2005, Member of the International Scientific Committee of the 4th MIM Pan African conference on Malaria (Cameroon)
1999, Best Postgraduate Student, PIMRAT, College of Medicine, University of Ibadan, Ibadan, Nigeria
1998, Wellcome Trust Award to the 1st Gordon Conference on Malaria (Oxford, UK)
1995, Best International Postgraduate Student, International Student association (ISA), University of Ibadan, Nigeria
1994 – 1997, Organization of African Unity (OAU) Research and Training Scholarship
1988 – 1993, Cameroon Government Scholarship
Personal life
He is married and has three children.
References
Living people
Year of birth missing (living people) | Christian Happi | [
"Chemistry"
] | 718 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
67,979,210 | https://en.wikipedia.org/wiki/Selene%20%28supercomputer%29 | Selene is a supercomputer developed by Nvidia, capable of achieving 63.460 petaflops, ranking as the fifth fastest supercomputer in the world, when it entered the list. Selene is based on the Nvidia DGX system consisting of AMD CPUs, Nvidia A100 GPUs, and Mellanox HDDR networking. Selene is based on the Nvidia DGX Superpod, which is a high performance turnkey supercomputer solution provided by Nvidia using DGX hardware. DGX Superpod is a tightly integrated system that combines high performance DGX compute nodes with fast storage and high bandwidth networking. It aims to provide a turnkey solution to high-demand machine learning workloads. Selene was built in three months and is the fastest industrial system in the US while being the second-most energy-efficient supercomputing system ever.
Selene utilizing 1080 AMD Epyc CPUs and 4320 A100 GPUs is used to train BERT, the natural language processor, in less than 16 seconds, which usually takes most smaller systems about 20 minutes to execute. IEEE Spectrum reported that as per December 2021 among all the commercially available supercomputing systems Selene topped all the results of MLPerf benchmark, which is the benchmark developed by the consortium of artificial intelligence developers from academia, research labs, and industry aiming to unbiasedly evaluate the training and inference performance for hardware, software, and services used for AI.
Selene is deployed by the Argonne National Laboratory to research different ways to end the coronavirus. It has been used to tackle problems around the concepts of protein docking and quantum chemistry, which are vital to developing an understanding of the coronavirus and a potential cure for it.
Nvidia used Selene to train its GauGAN2 AI model, which is used in Nvidia Canvas software to create art using artificial intelligence, using 10 million landscape images for training. GauGAN2 AI model uses segmentation mapping, inpainting, and text-to-image generation in a single model to create art.
See also
Computer science
Computing
Top500
References
External links
Nvidia's blog on Selene website
GPGPU supercomputers | Selene (supercomputer) | [
"Technology"
] | 474 | [
"Computing stubs",
"Computer hardware stubs"
] |
67,979,239 | https://en.wikipedia.org/wiki/Lakes380 | Lakes380 – Our Lakes' Health: past, present, future is a New Zealand limnology research project focussed on determining the health, wellness and history of about 10 per cent of New Zealand's 3800 lakes, by collecting surface water, sediment samples and sediment cores and using many different techniques including environmental DNA (eDNA), and other core scanning methods to analyze them. By drawing on both traditional Māori knowledge and biophysical science, it was intended to provide a public resource to assist the development of restoration and management plans for these lakes. The project is jointly led by GNS Science and the Cawthron Institute and works with a wide range of New Zealand and international participants and partners. It was initially a five-year (2017–2022) programme, funded by an Endeavour Fund grant from the Ministry of Business, Innovation and Employment.
Description
In the "Public Statement", as part of the funding application, it was noted that there was a lack of scientific knowledge about the health of approximately 95% of New Zealand lakes and an effective way to gain information would be to examine sediment cores to uncover their environmental history using the latest techniques such as eDNA and high-resolution scanning. The data would characterise current lake health, explore rates and drivers of change over the last 1000 years and provide a deeper understanding to inform the restorations of the ecological vitality of the lakes.
It was proposed that the data from this project would be used by "government agencies to undertake strategic assessments of water quality and health risk, prioritise mitigation strategies, characterise biodiversity, assess the distribution and impact of invasive species, and inform environmental policy. Regional councils, iwi/hapū and other communities will use this new knowledge to assist in setting informed and achievable restoration aspirations".
The project acknowledged the importance of building a close working relationship with iwi and hapū, drawing on the knowledge of Māori as a result of their historical relationships with the lakes.
Research team
The team is co-led by Susie Wood (Cawthron Institute) and Marcus Vandergoes (GNS Science) and has experts with a range of scientific expertise from universities and research organisations in New Zealand and overseas. It is supported by a Science, Advice and Implementation Group to provide guidance on strategy, quality and performance and prioritization of research directions. The project also has national and international collaborators and is in partnership with over 20 New Zealand organisations.
Aims
Obtain a nationwide health overview for about 10% (380) of New Zealand's lakes.
Collaborate with iwi and hapū to learn from their knowledge of the lakes to inform "joint aspirations for environmental reconstructions".
Collate data for use by government agencies, regional councils and communities to develop plans to restore and protect lakes.
Methodology
Lake bottom sediment and water samples and sediment cores were gathered from New Zealand lakes, with the samples then analysed using a range of methods to determine what lived in the lake, its current health, and to explore how and why the health of the lake had changed. Susie Wood explained that the sediments build up over time in a lake and hold a record of the lake and its surrounding catchment, and using a range of scientific techniques allowed the team to "recreate hundreds of years of history...like a storybook, going back in time". Marcus Vandergoes from GNS Science, said the cores were stored and scanned in a specially-built facility where the analysis of the samples of the material showed past, current and future ecological and environmental change. He noted that some samples were sent to institutions around the world to be analysed and half of each core was stored at −20 °C.
In the introduction to a presentation at European Geosciences Union's General Assembly in 2021, members of the research team explained the difference between the traditional paleolimnological methods of gathering data on sediments and the application of environmental DNA techniques. While Lakes380 used both methods, a key part of the project involved using 16S rRNA gene metabarcoding to explore how the microbial community had changed, particularly with regard to human intervention. It was stated that combining these molecular methods with "hyperspectral scanning and pollen data" increased the understanding of when and why these changes occurred.
There was a significant social science aspect to the project, including public access to lakes. In this subproject, the team aimed to "evaluate legal and practical access to lakes in the Lakes380 dataset for members of the public ... [with the lakes] ... selected based on geographic spread, altitude, species, catchment land cover, and cultural significance". It was shown that 33% of the lakes had good access while 28% could not be legally accessed due to private property issues. The importance of this work has been noted because "barriers to access lakes leads to the loss of lake knowledge, stories, cultural practices and enables lake degradation".
Regional sampling
In 2019, Lakes380 scientists gathered data from four lowland shallow lakes in the Southland region with a goal of using data to improve understanding of the current and historical conditions in the lakes.
In 2020, around 26 lakes in Waikato were sampled in a campaign regarded by Wood as the largest work of this sort ever in the region. Vandergoes said that each sample would provide important information about the nature and causes of how the lakes had changed. He explained that "Lake sediments are natural archives that continuously record environmental history, providing measures of current and historical Aquatic ecosystems and water quality."
During the same field sampling campaign, Lakes380 joined with a team from the University of Waikato to gather samples from three lakes to determine the effect of prehistoric earthquake activity and provide information on the potential risk to the city of Hamilton in 2020. The study established that lake sediments in the area included layers of volcanic ash (tephra) and that five layers of this in the cores showed possible signs of liquefaction, indicating that there may have been previously unrecognised earthquakes in the Hamilton lowlands over the past 20,000 years. Professor Lowe from Waikato University said that although Hamilton was known for having a low to moderate earthquake risk, this may now need to be revised, and "by studying the nature of the tephra layers using CT scanning and geotechnical methods, we aim to calculate the intensity of shaking and develop a new understanding of seismic hazard in and around Hamilton".
On 1 July 2020, the Otago Daily Times reported that samples collected from Queenstown lakes had revealed history going back thousands of years, providing what the University of Otago paleoclimatologist Chris Moy said was important information about how climate, environment and ecosystems in the area had changed over time. The sediment cores were analysed at the University of Otago, and other lakes in the region were also sampled.
Sampling was undertaken of lakes in the Rotorua area in 2019 and 2021 to gather evidence on how the arrival of humans and the eruption of Mount Tarawera in 1886 had impacted the ecosystems. As of February 2021, the findings had shown the bacterial communities within Lake Okataina had not returned to their pre-eruption state, and that in most of the lakes, there had been an increase of algae – possibly due to changes in land use and the introduction of other animals and plants. Nicki Douglas, Te Arawa Trust Environmental Manager, said that although alarming, the results were expected and the information could be used to enforce better biosecurity to protect the lakes as taonga for future generations.
Lake Rotoiti, in the Tasman region, has been noted by Wood as one of the most "pristine" in the country and she felt that the research, by working on lakes like this showed the importance of protecting the lake.
Working with tangata whenua
The Lakes380 project built in-depth relationships with iwi in the Wairarapa and Rangitikei districts as part of weaving together traditional knowledge, science and local history, and worked on a joint website to encourage conversations about the wellbeing of Wairarapa lakes. Environment manager Rawiri Smith of Ngāti Kahungunu ki Wairarapa, said the lake stories had provoked changes in thinking and behaviour based on "common humanity rather than through confirmation or enforcement", and Charlotte Šunde of the Cawthron Institute noted that "digital storytelling like this is a fairly new and very effective way of bringing lake stories to a wide audience, reaching far beyond the impact of scientific publications".
As the Lakes380 team travelled around Aotearoa, they worked closely with iwi in each region. For example in 2019, Lakes380 scientists collaborated with Ngāti Kurī to study the health of the lakes in Northland, which had dune lakes that were highly threatened aquatic habitats. Harry Burkhardt, the chair of the Ngāti Kuri Trust, said the project would help to get systems in place that will "protect the area's unique biodiversity and enhance the iwi's relationship with the natural world".
In May 2021, Ngāti Apa ki te Rā Tō, as mana whenua and kaitiaki of Nelson lakes, welcomed people to an information session to share knowledge of the work being done by Lakes380. Ngāti Apa ki te Rā Tō shared stories of their connections with the lakes, and the Lakes380 team showed how sediment cores are collected and how they allow the history of lakes to be explored.
When Ngāti Kahungunu ki Wairarapa launched a programme in August 2023 with the aim of understanding the water quality and diversity of Lake Wairapapa combining "scientific techniques and mātauranga Māori", they involved the Cawthron Institute and GNS Science to continue work they had done previously with Lakes380 that had provided information on the drivers of degradation of other lakes in the area. Scanning of sediment cores in these lakes showed how the water quality had changed historically [providing] "time-stamped data including what animals, plants, algae, and insects were present in and around the lake in each period and how changes in land use and management practices around the lake might have impacted the water quality." Examples from the time of post-European settlement included the effect of the burning of beech and podocarp forest causing layers of charcoal in the cores and introduced perch and trout, said by a leader of the team, [to have] "caused a big shift in the communities of bacteria that lived in the lake, indicating these fish are a major driver of the severe cyanobacterial blooms the lake [experienced] most summers." Ra Smith, the Environmental Manager for the iwi, said the ultimate goal was for "Lake Wairarapa to obtain its own tino rangatiratanga – or flourishing growth within its own ecosystem."
Educational opportunities
In 2019, the Partnership Through Collaboration Trust collaborated with scientists from Lakes380 and created a series of workshops for students. For the workshops held in Whanganui, the key learning points were: how to collect and assess a sediment core; understanding what cyanobacteria are and how they can be managed; and the use of environmental DNA to measure the biodiversity of lakes. Learning the traditional knowledge of Māori of the lakes was facilitated by Mike Paki who represented local iwi. Another workshop involved lake sediment analysis in Rotorua where students were taught how environmental DNA is utilised to gather data from sediment samples, and what the different layers in the core represent, for example, the grey ash that is believed to have come from the eruption of Mount Tarawera in 1886.
Lakes380 supported a number of university students. As part of her studies toward gaining a Master of Science, McKayla Holloway, from Victoria University and an employee of the Cawthron Institute, visited Lake Troup in Doubtful Sound to work as a part of the Lakes380 team gathering samples. The work proved challenging because of boulders below the surface of the lake, but Holloway said it was a "mission to find out the secret lives of New Zealand's lakes ... [that are] ... used for recreation as well as a source of drinking water, irrigation, and electricity generation ... [and] .. provide essential habitat for our freshwater species and have high cultural significance".
Amy Bridges, a student at Victoria University of Wellington, worked with the Lakes380 team to follow up on oral histories which suggested that two lakes may have been affected by tsunamis in the past. Samples from Lake Whakaki in Hawke's Bay were not able to be dated because they were a mixture of reeds and shells. While those from Lake Moawhitu on D'Urville Island didn't show direct proof of tsunami, the work done was acknowledged as being useful for future research that could look at the grain sizes to figure out possible causes of this mixing. Bridges said, "it is still possible that a tsunami did occur, so further research focusing on sediment from other parts of the lake could provide more insight".
As a result of a partnership with GNS Science, BLAKE, a New Zealand organisation established in recognition of Sir Peter Blake, awarded an Ambassador Programme to Soltice Morrison, noting that she would work with Lakes380 and "learn about environmental reconstruction and monitoring techniques and contribute to the effort to understand the health of New Zealand's lakes through time to the present day ... [assisting with] ... the field collection and laboratory analytics teams".
Related awards
In the Queen's Birthday Honours 2021, Emeritus Professor Carolyn Burns CBE from Otago University was awarded Dame Companion of the New Zealand Order of Merit for services to ecological research. Burns was involved with the Lakes380 project in their Science, Advice and Implementation Group. She had also used the samples collected by the Lakes380 team, to study the factors that allowed two invasive species of Daphnia to spread into some New Zealand lakes, concluding from the evidence, that "it's looking as though dispersal might be related to distance to the nearest road – how accessible lakes are to humans".
Gallery
References
External links
Susie Wood on Radio 95bFM
Lakes380 project – Taranaki sites
Images of all lakes in the project
Interactive site showing interim results
Research in New Zealand
Environmental science
Water
Water management
Water pollution
Water supply | Lakes380 | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 2,912 | [
"Hydrology",
"Water pollution",
"nan",
"Environmental engineering",
"Water",
"Water supply"
] |
67,979,652 | https://en.wikipedia.org/wiki/GI%20Tauri%20and%20GK%20Tauri | GK Tauri is a young T Tauri-type pre-main sequence star in the constellation of Taurus about away, belonging to the Taurus Molecular Cloud.
System
The stars GK Tauri and GI Tauri form a wide binary system, with the projected separation between components being 1700 AU. The secondary component's orbit is not very eccentric, with a periastron of at least 890 AU.
GK Tauri was originally believed to have a close stellar companion WDS J04336+2421Ab. However, it was found to be an unrelated background star according to Gaia data.
Properties
Both members of the binary system are medium-mass objects still contracting towards the main sequence and accreting mass, with the primary GK Tauri being close to entering the main sequence.
Protoplanetary system
Both stars are surrounded by compact protoplanetary disks, although the reason for the small disk sizes is not clear. GK Tauri's spectrum indicates a possible gap in the protoplanetary disk and a planet orbiting within the gap, with a semimajor axis of 2.4 AU.
References
Binary stars
T Tauri stars
Circumstellar disks
Taurus (constellation)
J04333456+2421058
Tauri, GI
Hypothetical planetary systems | GI Tauri and GK Tauri | [
"Astronomy"
] | 266 | [
"Taurus (constellation)",
"Constellations"
] |
67,980,734 | https://en.wikipedia.org/wiki/Imperial%20College%20Computing%20Engine | ICCE I and ICCE II were digital computers built at the Imperial College Department of Mathematics in the post-war period.
Computing engines
ICCE I
The first Imperial College Computing Engine, ICCE I, was constructed by Sidney Michaelson, Tony Brooker and Keith Tocher in the Department of Mathematics at Imperial College London in the late 1940s and early 1950s. It was a relay based machine which gave relatively slow but highly reliable service. Its current whereabouts are unknown.
ICCE II
ICCE II was constructed by Sidney Michaelson, Keith Tocher and Manny Lehman in the early 1950s. This valve based machine was never completed. ICCE II was taken by Keith Tocher to British Steel. Its current whereabouts are unknown.
Influence on other machines
ICCE I and II influenced the design of SABRAC, the computer constructed in Israel by The Israeli MoD Scientific Department.
Project termination
In 1956/7, the project was forcibly terminated. Staff dispersed. In 1951 Tony Brooker had left to join the Computing Machine Laboratory at the University of Manchester. Keith Tocher took ICCE II and went to work at British Steel, Sidney Michaelson went to the University of Edinburgh and founded the Computer Unit which subsequently became the Department of Computer Science, now the school of informatics. Manny Lehman ultimately joined the Israeli MoD Scientific Department which subsequently became Rafael.
See also
Wilks MV and Stringer LJB, Micro-Programming and the Design of the Control Circuits in an Electronic Computer, Proc. Camb. Phil. Soc., vol 49, no. 2, 1953
Tocher KD, Classification and Design of Operation Codes for Automatic Computers, Proc. IEE, 103B, Supplement 1, Apr. 1956
Tocher KD and Lehman MM, A Fast Parallel Arithmetic Unit, Proc. IEE 103B, Supplement 3, Apr. 1956, pp. 520 - 527
Lehman MM, Parallel Arithmetic Units and Their Control, PhD Thesis, University of London, Feb. 1957, 160pps.+
Lehman MM, Short-Cut Multiplication and Division in Automatic Binary Digital Computers with Special Reference to a New Multiplication Process, Proc. IEE, vol 105, Part B, No 23, Sept 1958, pps. 496 - 504
Tocher KD, Techniques of Multiplication and Division for Automatic Binary Computers, Quart. J. of Mechanics and Appl. Maths., v. 11, p. 3, 1958, pps. 364 - 384
http://www.macs.hw.ac.uk/~greg/icce/
References
British
Computers designed in the United Kingdom
Electro-mechanical_computers
History of computing in the United Kingdom | Imperial College Computing Engine | [
"Technology"
] | 544 | [
"History of computing",
"History of computing in the United Kingdom"
] |
65,210,660 | https://en.wikipedia.org/wiki/Sylvie%20Cloutier | Sylvie Cloutier is a Canadian scientist. She is a specialist in molecular genetics at Agriculture and Agri-Food Canada's Ottawa Research and Development Centre and an adjunct professor at the University of Ottawa. She has co-led two Genome Canada Large Scale Applied Research projects of $11M each and has been involved in over 110 published research papers and made contributions to many books.
Early life and education
Cloutier was born and raised near Quebec City. She attended Laval University to complete her undergraduate degree. She completed a Master of Science in Biotechnology at the University of Guelph, and her PhD at the University of Montreal, studying molecular genetics.
Career
Cloutier worked for the Canadian Food Inspection Agency (CFIA) in 1987 to inspect fields of certified seeds. She spent a brief time as a lecturer at the University of Montreal teaching a class on tissue culture in 1992. She also taught a graduate course on molecular genomics at the University of Manitoba in 2004. Cloutier is currently an adjunct professor for the University of Ottawa.
Cloutier began her Career at Agriculture and Agri-Food Canada (AAFC) in Winnipeg in 1996. Her research focused primarily on flax and wheat. In 2014 she was given the opportunity to join AAFC’s Eastern Cereal and Oilseed Research Centre (ECORC) in Ottawa after the closing of the Cereal Research Center in Winnipeg. With this change, her research focus shifted to wheat pre-breeding in particular rust diseases, the wheat midge insect, and continuing her work on epigenetics. In her career, Sylvie has been involved in over 110 published research papers and has contributed to numerous books.
Some of her current projects include the construction of physical maps of important seed quality traits, identification of wheat disease resistance genes, map-based cloning and sequencing of the wheat leaf rust resistance gene Lr1, and molecular genetics of the leaf rust pathosystem through gene expression profiling using microarrays. She currently co-leads the Genome Canada project “4DWheat: Diversity, Domestication, Discovery and Delivery” which aims to harness the genetic diversity from wild relatives through de novo sequencing of Aegilops species, annotation, transcriptomics, comparative analysis and high-throughput phenotyping. 4DWheat will apply the latest genomic strategies and focus on two major challenges: enhancing yield and managing producer risk to important diseases. Wheat is the most important crop for global food security, so meeting the challenge of increasing wheat production to match the growing demand is of high importance.
Honours and awards
Rosemary Davis award by Farm Credit Canada in recognition of her leadership in Agriculture (March 2013)
References
Agriculture and Agri-Food Canada
Canadian geneticists
Université Laval alumni
University of Guelph alumni
Université de Montréal alumni
Molecular geneticists
Year of birth missing (living people)
Living people
Scientists from Quebec
20th-century Canadian women scientists
21st-century Canadian women scientists
Canadian women geneticists | Sylvie Cloutier | [
"Biology"
] | 598 | [
"Molecular geneticists",
"Molecular genetics"
] |
65,210,891 | https://en.wikipedia.org/wiki/Vantage%20sensitivity | Vantage sensitivity is a psychological concept related to environmental sensitivity, initially developed by Michael Pluess and Jay Belsky. It describes individual differences in response to positive experiences and supportive environmental influences. According to vantage sensitivity, people differ considerably in their sensitivity to positive aspects of the environment, with some people benefitting particularly strongly from positive experiences such as parental care, supportive relationships, and psychological interventions, whereas others tend to respond less or not at all.
Background
The concept of vantage sensitivity is related to other theories of environmental sensitivity such as differential susceptibility according to which some people are more sensitive than others to both negative and positive experiences. Vantage sensitivity provides a specific theoretical perspective and terminology to describe individual differences in response to exclusively positive experiences.
According to vantage sensitivity theory, people who benefit from positive experiences display vantage sensitivity as a function of vantage sensitivity factors (i.e., genetic, physiological, or psychological traits) whereas those who benefit less show vantage resistance due to the presence of vantage resistance factors (or the absence of vantage sensitivity factors). Differences in vantage sensitivity are considered to reflect neurobiological differences in the central nervous system, which are influenced by genetic as well as environmental factors.
Evidence
A growing number of studies provide empirical evidence for individual differences in vantage sensitivity across a wide range of established sensitivity markers, including genetic, physiological, and psychological ones.
Genetic markers
Several studies report that differences in response to positive experiences are associated with genetic sensitivity. For example, Keers et al. created a polygenic score for environmental sensitivity based on thousands of gene variants and found that children with higher genetic sensitivity responded more strongly to higher quality of psychological treatment.
Physiological markers
Studies suggest that a higher physiological reactivity to stress (indicated by cortisol) is associated with a stronger positive response to positive influences. For instance, a study testing the efficacy of exposure-based psychotherapy, a type of psychological treatment that is used with people suffering from panic disorders and agoraphobia, found that people whose cortisol response was higher during exposure were also more likely to recover faster and benefit more from the treatment.
Psychological markers
A number of studies have shown that children who score high on the Highly Sensitive Child (HSC) scale, a psychometric tool designed to measure sensitivity, respond more positively to psychological interventions. For example, Nocentini et al. conducted a randomised controlled trial to investigate whether sensitivity was associated with greater response to a school-based anti-bullying intervention. Results indicated that sensitive children benefitted significantly more from the positive effects of the intervention. Vantage sensitivity has also been found to influence the socio-emotional well-being of young people in school. The wellbeing of sensitive adolescents increased in response to positive changes in the school environment. In adults, high sensitivity has been found to predict a greater response to positive pictures and increased leader-rated employee task performance.
Related concepts
Diathesis-stress model
Differential susceptibility
Environmental sensitivity
Gene-environment interaction
Highly sensitive person
Sensory processing sensitivity
References
Environmental sensitivity
Developmental psychology | Vantage sensitivity | [
"Biology"
] | 606 | [
"Behavioural sciences",
"Behavior",
"Developmental psychology"
] |
65,214,425 | https://en.wikipedia.org/wiki/Hexaphosphabenzene | Hexaphosphabenzene is a valence isoelectronic analogue of benzene and is expected to have a similar planar structure due to resonance stabilization and its sp2 nature. Although several other allotropes of phosphorus are stable, no evidence for the existence of has been reported. Preliminary ab initio calculations on the trimerisation of leading to the formation of the cyclic were performed, and it was predicted that hexaphosphabenzene would decompose to free with an energy barrier of 13−15.4 kcal mol−1, and would therefore not be observed in the uncomplexed state under normal experimental conditions. The presence of an added solvent, such as ethanol, might lead to the formation of intermolecular hydrogen bonds which may block the destabilizing interaction between phosphorus lone pairs and consequently stabilize . The moderate barrier suggests that hexaphosphabenzene could be synthesized from a [2+2+2] cycloaddition of three molecules. Currently, this is a synthetic endeavour which remains to be conquered.
Synthesis
Isolation of hexaphosphabenzene was first achieved within a triple-decker sandwich complex in 1985 by Scherer et al. Amber coloured, air-stable crystals of [{(η5-Me5C5)Mo}2(μ,η6-P6)] are formed by reaction of with excess in dimethylbenzene, albeit with a yield of approximately 1%. The crystal structure of this complex is a centrosymmetric molecule, and both five-membered rings as well as the central bridge-ligand ring are planar and parallel. The average P–P distance for the hexaphosphabenzene within this complex is 2.170 Å.
Thirty years later, Fleischmann et al. improved the synthetic yield of [{(η5-Me5C5)Mo}2(μ,η6-P6)] up to 64%. This was achieved by increasing the reaction temperature of the thermolysis of with to approximately 205 °C in boiling diisopropylbenzene, thus favouring the formation of [{(η5-Me5C5)Mo}2(μ,η6-P6)] as the thermodynamic product.
Several analogues of this triple‐decker complex where the coordinating metal and η5-ligand has been varied have also been reported. These include triple‐decker complexes for Ti, V, Nb, and W, whereby the synthetic method is still based on the originally reported thermolysis of with .
Electron count
If one regards the planar ring as a 6π electron donor ligand, then [{(η5-Me5C5)Mo}2(μ,η6-P6)] is a triple-decker sandwich complex with 28 valence electrons. If , similar to C6H6, is taken as a 10π electron donor, a 32 valence electron count may be obtained. In most triple-decker complexes with an electron count ranging from 26 to 34, the structure of the middle ring is planar ([{(η5-Cp)M}2(μ,η6-P6)] with M = Mo, Sc, Y, Zr, Hf, V, Nb, Ta, Cr, and W). In the 24 valence electron [{(η5-Cp)Ti}2(μ,η6-P6)] complex, however, a distortion is observed, and the ring is puckered.
Calculations have concluded that completely filled 2a*and 2b* orbitals in 28 valence electron complexes lead to a planar symmetrical middle ring. In 26 valence electron complexes, the occupancy of either 2a*or 2b* results in in-plane or bisallylic distortions and an asymmetric planar middle ring. The puckering of in 24 valence electron complexes is due to the stabilization of 5a, as well as that conferred by the tetravalent oxidation state of Ti in [{(η5-Cp)Ti}2(μ,η6-P6)].
Reactivity
One-electron oxidation
The reactivity of [{(η5- Me5C5)Mo}2(μ,η6-P6)] toward silver and copper monocationic salts of the weakly coordinating anion [Al{OC(CF3)3}4]− ([TEF]) was studied by Fleischmann et al. in 2015. Addition of a solution of Ag[TEF] or Cu[TEF] to a solution of [{(η5- Me5C5)Mo}2(μ,η6-P6)] in chloroform results in oxidation of the complex, which can be observed by an immediate colour change from amber to dark teal. The magnetic moment of the dark teal crystals determined by the Evans NMR method is equal to 1.67 μB, which is consistent with one unpaired electron. Accordingly, [{(η5- Me5C5)Mo}2(μ,η6-P6)]+ is detected by ESI mass spectrometry.
The crystal structure of the teal product shows that the triple‐decker geometry is retained during the one‐electron oxidation of [{(η5- Me5C5)Mo}2(μ,η6-P6)]. The Mo—Mo bond length of the [{(η5- Me5C5)Mo}2(μ,η6-P6)]+ cation is 2.6617(4) Å; almost identical to the bond length determined for the unoxidized species at 2.6463(3) Å. However, the P—P bond lengths are strongly affected by the oxidation. While the P1—P1′ and P3—P3′ bonds are elongated, the remaining P—P bonds are shortened compared to the average P—P bond length of about 2.183 Å in the unoxidized species. Therefore, the middle deck of the 27 valence electron [{(η5- Me5C5)Mo}2(μ,η6-P6)]+ complex can best be described as a bisallylic distorted P6 ligand, intermediate between the 28 valence electron complexes with a perfectly planar symmetrical ring, and those with 26 valence electrons displaying a more amplified in-plane distortion. Density functional theorem (DFT) calculations confirm that this distortion is due to depopulation of the P bonding orbitals upon oxidation of the triple-decker sandwich complex.
Cu[TEF] & Ag[TEF]
To avoid oxidation of [{(η5- Me5C5)Mo}2(μ,η6-P6)], further reactions were performed in toluene to decrease the redox potential of the cations. This resulted in a bright orange coordination product upon reaction with copper, although a mixture also containing the dark teal oxidation product was obtained upon reaction with silver.
Single‐crystal X‐ray analysis reveals that this product displays a distorted square‐planar coordination environment around the central cation through two side‐on coordinating P—P bonds. The Ag—P distances are approximately 2.6 Å, whereas the Cu—P distances are determined to be approximately 2.4 Å. The P—P bonds are therefore elongated to 2.2694(16) Å and 2.2915(14) Å upon coordination to copper and silver, respectively, whilst the remaining P—P bonds are unaffected.
In another experiment Cu[TEF] is treated with [{(η5- Me5C5)Mo}2(μ,η6-P6)] in pure toluene and the solution shows the bright orange color of the complex cation [Cu([{(η5- Me5C5)Mo}2(μ,η6-P6)])2]+. However, analysis of crystals from this solution reveals a distorted tetrahedral coordination environment around Cu. The resulting Cu—P distances are somewhat shorter than their counterparts discussed above. The coordinating P—P bonds are a little longer, which is attributed to less steric crowding in the tetrahedral coordination geometry around the Cu center.
The successful isolation of [Cu([{(η5- Me5C5)Mo}2(μ,η6-P6)])2]+ either as its tetrahedral or square‐planar isomer is therefore achievable. DFT calculations show that the enthalpy for the tetrahedral to square‐planar isomerization is positive for both metals, with the tetrahedral coordination being favored. When entropy is taken into account, small positive values for Cu+ and larger, but negative, values for Ag+ are observed. This means that the tetrahedral geometry is predominant for Cu+, but a significant percentage of the complexes adopt a square‐planar geometry in solution. For Ag+, the equilibrium is shifted significantly to the right side, which is presumably why a tetrahedral coordination of [{(η5- Me5C5)Mo}2(μ,η6-P6)] and Ag+ has not yet been observed.
Examination of the crystal packing reveals that these products are layered compounds that crystallize in the monoclinic C2/c space group with alternating negatively charged layers of the [TEF] anions and positively charged layers of isolated [M([{(η5- Me5C5)Mo}2(μ,η6-P6)])2]+ complexes. The layers lie inside the bc plane, alternate along the a axis, and do not form a two‐dimensional network.
Tl[TEF]
The treatment of [{(η5- Me5C5)Mo}2(μ,η6-P6)] with Tl[TEF] in chloroform gives an immediate color change from amber to a deep red. The crystal structure reveals a trigonal pyramidal coordination of the thallium cation, Tl+, by three side‐on coordinating P—P bonds of the P6 ligands. Two of these P6 ligands show shorter and uniform Tl—P distances of 3.2–3.3 Å with P—P bonds elongated to about 2.22 Å, whilst the third unit shows an unsymmetrical coordination with long Tl—P distances of approximately 3.42 and 3.69 Å and no P—P bond elongation.
Although the environment of Tl+ is distinctly different from that of Cu+ and Ag+, their structures are related by the two‐dimensional coordination network that propagates inside the bc plane. Crucially, whilst Cu+ and Ag+ form layered structures with isolated [M([{(η5- Me5C5)Mo}2(μ,η6-P6)])2]+ complex cations, there is a statistical distribution of the Tl+ cations inside the two‐dimensional coordination, which shows further interconnection of the P6 ligands to form an extended 2D network that could be regarded as a supramolecular analogue of graphene.
Jahn–Teller distortion
Despite the triple-decker sandwich complex {(η5-Me5C5)Mo}2(μ,η6-P6) containing a demonstrably planar P6 ring with equal P—P bond lengths, theoretical calculations reveal that there are at least 7 non-planar P6 isomers lower in energy than the planar benzene-like D6h structure. In increasing order of energy these are: benzvalene, prismane, chair, Dewar benzene, bicyclopropenyl, distorted benzene, and benzene.
A pseudo Jahn–Teller effect (PJT) is responsible for distortion of the D6h benzene-like structure into the D2 structure, which occurs along the e2u doubly degenerate mode as a result of vibronic coupling of the HOMO − 1 (e2g) and LUMO (e2u): e2g ⊗ e2u = a1u ⊕ a2u ⊕ e2u. The distorted structure is calculated to lie just 2.7 kcal mol−1 lower in energy than the D6h structure. If the uncomplexed structure were to be successfully synthesized, the aromaticity of the benzene-like P6 structure would not be sufficient to stabilize the planar geometry, and the PJT effect would result in distortion of the ring.
Isomers
Adaptive Natural Density Partitioning (AdNDP) is a theoretical tool developed by Alexander Boldyrev that is based on the concept of the electron pair as the main element of chemical bonding models. It can therefore recover Lewis bonding elements such as 1c–2e core electrons and lone pairs, 2c–2e objects which are two-center two-electron bonds, as well as delocalized many-center bonding elements with respect to aromaticity.
The AdNDP analysis of the seven representative low-lying P6 structures reveal that these are well described by the classical Lewis model. A lone pair on each phosphorus atom, a two-center-two-electron (2c–2e) σ-bond in every pair of adjacent P atoms, and an additional 2c–2e π-bond between adjacent 2-coordinated P atoms are found, with occupation numbers (ON) of all these bonding elements above 1.92 |e|.
The chemical bonding in the chair structure is unusual. Based on fragment orbital analysis, it was concluded that two linkages between the two P3 fragments are of the one-electron hemibond type. The AdNDP analysis reveals a lone pair on each P atom and six 2c–2e P—P σ-bonds. One 3c–2e π-bond in every P3 triangle was revealed with the user-directed form of the AdNDP analysis, as well as a 4c–2e bond responsible for bonding between the two P3 triangle, confirming that this isomer cannot be represented by a single Lewis structure, and requires a resonance of two Lewis structures, or can be described by a single formula with delocalized bonding elements.
Both the D6h benzene-like structure, as well as the D2 isomer of P6 is similar to the reported AdNDP bonding pattern of the C6H6 benzene molecule: 2c–2e σ-bond and lone pairs, as well as delocalized 6c-2e π-bonds. The distortion due to the PJT effect therefore does not significantly disturb the bonding picture.
Suppression
The planar P6 hexagonal structure D6h is a second-order saddle point due to the pseudo-Jahn–Teller effect (PJT), which leads to the D2 distorted structure. Upon sandwich complex formation the PJT effect is suppressed due to filling of the unoccupied molecular orbitals involved in vibronic coupling in P6 with electron pairs of Mo atoms. Specifically, from molecular orbital analysis it was determined that, upon complex formation, the LUMO in the isolated P6 structure is now occupied in the triple-decker complex as a result of the appreciable δ-type M → L back-donation mechanism from the occupied dx2–y2 and dxy atomic orbitals of the Mo atom into the partially antibonding π molecular orbitals of P6, thus restoring the high symmetry and planarity of P6.
References
Phosphorus
Sandwich compounds
Inorganic chemistry
Solid-state chemistry
Hypothetical chemical compounds
Aromatic compounds
Six-membered rings | Hexaphosphabenzene | [
"Physics",
"Chemistry",
"Materials_science"
] | 3,308 | [
"Aromatic compounds",
"Hypotheses in chemistry",
"Sandwich compounds",
"Organic compounds",
"Theoretical chemistry",
"Condensed matter physics",
"Hypothetical chemical compounds",
"nan",
"Organometallic chemistry",
"Solid-state chemistry"
] |
65,214,756 | https://en.wikipedia.org/wiki/5%2C6-Dihydro-5%28%CE%B1-thyminyl%29thymine | 5,6-Dihydro-5(α-thyminyl)thymine is a DNA pyrimidine dimer photoproduct produced when DNA in bacterial spores is exposed to ultraviolet light. In bacteria, this DNA base dimer deforms the structure of DNA, so endospore forming bacteria have an enzyme called spore photoproduct lyase that repairs this damage.
Laboratory synthesis
5,6-Dihydro-5(α-thyminyl)thymine can also be synthesized in a laboratory by reacting 5-hydroxymethyluracil and 6-aminothymine yielding 5,6-dihydro-6-imino-5-(α-thyminyl)thymine. When hydrogen is added in a reduction then 5,6-dihydro-5(α-thyminyl)thymine is the product.
References
Pyrimidinediones
Dimers (chemistry) | 5,6-Dihydro-5(α-thyminyl)thymine | [
"Chemistry",
"Materials_science"
] | 197 | [
"Dimers (chemistry)",
"Polymer chemistry"
] |
65,215,912 | https://en.wikipedia.org/wiki/H%C3%A9l%C3%A8ne%20Perrin | Hélène Perrin (born 1972) is a French physicist working on quantum gas at Laser Physics Laboratory of Université Sorbonne Paris Nord and CNRS, where she is a research director and leads the Bose-Einstein Condensate group.
Education and career
Hélène Perrin studied physics and engineering at the Ecole Polytechnique after studying at Lycée Louis-le-Grand, and pursued a master's degree in quantum physics at Ecole Normale Superieure, before pursuing a doctorate within Claude Cohen-Tannoudji's group on the topic of ultracold atoms, which she completed in 1998. She then joined the French Alternative Energies and Atomic Energy Commission as a postdoctoral fellow before becoming a CNRS staff scientist in 1999.
References
External links
1972 births
Living people
Quantum physicists
French physicists
French women physicists
École Polytechnique alumni
Research directors of the French National Centre for Scientific Research | Hélène Perrin | [
"Physics"
] | 180 | [
"Quantum physicists",
"Quantum mechanics"
] |
65,216,787 | https://en.wikipedia.org/wiki/Otomefud%C5%8Dhara%20Tile%20Kiln | The is an archaeological site with the ruins of an early Nara period kiln, located in the city of Oyama, Tochigi Prefecture in the northern Kantō region of Japan. It was designated a National Historic Site of Japan in 1978.
Overview
roof tiles made of fired clay were introduced to Japan from Baekche during the 6th century along with Buddhism. During the 570s under the reign of Emperor Bidatsu, the king of Baekche sent six people to Japan skilled in various aspects of Buddhism, including a temple architect. Initially, tiled roofs were a sign of great wealth and prestige, and used for temple and government buildings. The material had the advantages of great strength and durability, and could also be made at locations around the country wherever clay was available.
The Otomefudōhara site is located at the western end of a plateau that extends along the left bank of the Omoi River, a tributary of the Watarase River that flows through the west of Oyama city. The ruins of four tile kilns were confirmed by a survey in 1976 lined up on the northern slope of the plateau, along with a clay excavation pit and the foundations of workshops. All of the kilns are anagama-style kilns, and traces of ash spread 80 meters east-west and 30 meters north-south in the valley in front of the ruins. The site has been known for centuries as a location where roof tile shards could be found. The presence of kiln ruins was conformed in 1977 and an excavation survey was conducted over 5 years from 1988.
Excavations found 66 roof tiles in a number of styles, including a style similar to Hakuho period tiles, and tiles with arabesque decorations. These same types of tiles have been excavated from the nearby Shimotsuke Yakushi-ji temple ruins and the Shimotsuke Kokubun-ji ruins.
The unearthed artifacts are stored and displayed in the adjacent Oyama City Museum, and the site was opened to the public as the Otome Kawaranosato Park, the first historic park in Oyama, in 1998. The site is about a 7 minute walk from Mamada Station on the JR East Tohoku Main Line.
See also
List of Historic Sites of Japan (Tochigi)
References
External links
Tochigi Tourist Information home page
Oyama City home page
Oyama, Tochigi
Historic Sites of Japan
History of Tochigi Prefecture
Shimotsuke Province
Nara period
Japanese pottery kiln sites | Otomefudōhara Tile Kiln | [
"Chemistry",
"Engineering"
] | 509 | [
"Kilns",
"Japanese pottery kiln sites"
] |
65,216,890 | https://en.wikipedia.org/wiki/Lewis%20acidic%20antimony%20compounds | Among pnictogen group Lewis acidic compounds, unusual lewis acidity of Lewis acidic antimony compounds have long been exploited as both stable conjugate acids of non-coordinating anions ( and ), and strong Lewis acid counterparts of well-known superacids (magic acids, fluoroantimonic acid). Also, Lewis-acidic antimony compounds have recently been investigated to extend the chemistry of boron because of the isolobal analogy between the vacant p orbital of borane and σ*(Sb–X) orbitals of stiborane, and the similar electronegativities of antimony (2.05) and boron (2.04).
Origin of acidity
σ*(Sb–X), where X describes substituents on antimony, contributes to the Lewis acidity of antimony compounds in two ways: donor–acceptor orbital interaction and electrostatic interaction. These two contributions to the Lewis acidity have been evaluated. Both contributions are studied by calculations, and the acidities of theses compounds are quantified by the Gutmann–Beckett method, Hammett acidity function, pKa, and fluoride ion affinity (FIA). FIA is defined as the amount of energy released upon binding a fluoride ion in the gas phase. The FIA of two popular strong Lewis acids, BF3 and B(C6F5)3, are respectively.
Donor–acceptor orbital overlap
Since Lewis adducts are formed by dative bond between Lewis bases and Lewis acids, the orbital overlap between the Lewis base and σ*(Sb–X) orbital is the source of the acidity. According to Gabbaï et al., NBO analysis of the Sb(C6F5)3P(O)Ph3 adduct indicates a donor-acceptor interaction between lp(O) and σ*(Sb–C6F5).
Lowering the LUMO (σ*(Sb–X)) energy increases the Lewis acidity. For example, Sb(C6H5)3 has a higher LUMO energy (−0.55 eV) and weaker FIA (59 kcal/mol) than Sb(C6F5)3 (−1.76 eV and 89 kcal/mol).
Electrostatic interaction
Partial positive charges on the surface of antimony compounds interact with partial negative charges. For example, Sb(C6F5)3(o-O2C6Cl4) has a more positively charged site than Sb(C6F5)3 as shown in its electrostatic potential map, corresponding to higher Lewis acidity (the FIA of Sb(C6F5)3(o-O2C6Cl4) and Sb(C6F5)3 are 116 and 89 kcal/mol, respectively).
Structure of Lewis acidic antimony compounds
Lewis acidic antimony complexes with a variety of oxidation states and coordination numbers are known. Several salient examples are introduced below.
3-coordinate Sb(III)
Although stibanes have a lone pair electrons, their antibonding orbitals with electron-withdrawing substituents renders them Lewis acidic. Sb(C6F5)3 (3) has three σ*(Sb–C6F5) orbitals and three Lewis acidic sites. However, as shown in the electrostatic potential map of Sb(C6F5)3, only one site is accessible to Lewis bases due to the asymmetric arrangement of the three aryl rings.
In [Sb(tol)(Cp*)]2+ (1), the η5-Cp* binding mode is confirmed using IBO analysis. In the solid state structure, the Sb-C bond distances between Sb and carbons in the Cp* ring are 2.394(4) to 2.424(4) Å, but the Sb–C bond distances with the toluene are 2.993(5) to 3.182(5) Å. This longer Sb–toluene distance implies toluene lability in solution.
Sb2(o-catecholate)2(μ-O) (2) had been predicted that a Lewis base would bind to two antimony centers in a bridging manner. However, it was observed that 2 binds with halide anions in various ratios (3:1, 2:1, 1:1, 1:2, 1:3). Cozzolono et al. suggested three reasons for its complex binding mode. First, rotational freedom around the bridge oxygen disrupts the Lewis base binding between two antimony centers. Second, intramolecular interactions between oxygen at catecholate and antimony competes with external Lewis base binding. Third, a high-polarity nucleophilic solvent, dimethylsulfoxide, is required to dissolve 2 due to the solubility and the solvent is also able to bind at antimony.
3-coordinate Sb(V)
[SbPh3]2+ (4) was not isolated. Instead, its Lewis adducts, [SbPh3(OPPh3)2]2+ and [SbPh3(dmap)2(OTf)]+, were isolated. In the trigonal bipyramidal [SbPh3(OPPh3)2]2+, two OPPh3 are located in axial positions and the Sb–O bond distance (2.102(2) Å) is similar to the sum of the covalent radii of Sb and O (2.05 Å). In the distorted octahedral [SbPh3(dmap)2(OTf)]+, the Sb–N distance with the dmap (2.222(2) Å) is shorter than reported N–Sb+ distances. This bond distance implies Lewis adduct formation. In addition, a reaction between dmap and [SbPh3(OPPh3)2]2+ forms [SbPh3(dmap)2(OTf)]+. The experimental results indicate that [SbPh3]2+ is the Lewis acidic counterpart of these adducts.
4-coordinate Sb(V)
Tetrahedral stibonium cations also show Lewis acidity. Since [Sb(C6F5)4]+ (5) forms an adduct with triflate, the cation can be isolated as a [Sb(C6F5)4][B(C6F5)4] salt. Short Sb–C bond distances of 2.095(2) Å and a tetrahedral space group in the crystal proves that isolated [Sb(C6F5)4]+ is completely free of external electron donors. This cationic antimony Lewis acid shows strong acidity: firstly, [Sb(C6F5)4]+ abstracts fluoride anion from weakly coordinating anions, , and secondly, the acidity measured by the Gutmann–Beckett method of [Sb(C6F5)4]+ (5) is comparable with that of the B(C6F5)3 adduct in CH2Cl2 (76.6 ppm).
SbPh3(Ant)+ (6) (where Ant is 9-anthryl) was isolated as triflate salt. 6 has a tetrahedral structure like 5. In a solid state structure of a fluoride adduct, AntPh3SbF, the incoming fluoride occupies the axial position of a trigonal bipyramidal structure, and the sterically-demanding anthryl is located at the equatorial site.
5-coordinate Sb(V)
Neutral Sb(V) complexes are also Lewis acids. Compounds 7, 8 and 11 share the structure of spirocyclic stiborane. The LUMO of 8 mainly has its lobe at the antimony atoms and it renders 8 Lewis acidic. In detail, the LUMO can be assigned to as localized orbital on stiborafluorene moiety with larger nodes at the 9-position (Sb). Thus, Lewis bases bind towards trans to biphenylene and its fluoride adducts are asymmetric: 8·F− has two enantiomers and 7·F− has two diastereomers and four enantiomers.
A bisantimony complex (9) is synthesized starting from xanthene. 9 has C2 symmetry and the Sb–Sb distance is 4.7805(7) Å. Both antimony(V) centers have distorted square pyramidal geometry with the geometry index τ5 = 0.08. The base planes of the antimony centers meet face to face and this geometry allows 1:1 binding with F−, unlike 2.
Trends in acidity
Inductive effect
Introduction of electron-withdrawing substituents on antimony results in increased acidity. For example, intramolecular donor–acceptor interactions of two stiboranes, o-C6H4(PPh2)[SbPh2(O2C6Cl4)] and o-C6H4(PPh2)[Sb(C6F5)2(O2C6Cl4)], have been analyzed by AIM. AIM analysis of electron density at the bond critical point (bcp) and delocalization index indicates that electron-withdrawing substituents on Sb(V) lead to an increased P–Sb bonding covalency.
{| class="wikitable"
|+AIM analysis of the intramolecular donor-acceptor interactions of two stiboranes
!P-Sb bonding
!o-C6H4(PPh2)(Sb(C6F5)2(O2C6Cl4)
!o-C6H4(PPh2)(Sb(C6H5)2(O2C6Cl4)
|-
|Electron density at the bcp (e/rBohr3)
|0.054
|0.035
|-
|Delocalization index
|0.38
|0.24
|}
Bisantimony compounds vs mono-antimony compounds
A bisantimony complex (9) is a stronger Lewis acid than a monoantimony compound (8) because both Lewis acidic sites cooperatively contribute to the Lewis base binding. The electrostatic potential map of 9 shows positive charges on the Sb centers facing each other.
This cooperativity is supported by the Sb-(μ-F)-Sb moiety in solid state structure of F− binding bisantimony compound 9.
Reactions
Fluoride anion sensor
The 9-anthryltriphenylstibonium cation (5) shows weak fluorescent emission (Φ = 0.7%), but a corresponding fluoride adduct, fluorostiborane, shows a strong anthryl-based emission at 427 nm (Φ = 9.5% in CHCl3). Owing to its stability in water, 5 could in principle be used as an aqueous fluoride sensor. Fluoride-selective electrodes were developed by using Lewis acidic antimony compounds as ionophores.
Catalysis
Strongly acidic antimony compounds catalyze organic transformations such as the transfer hydrogenation and the Ritter reaction.
Tetraarylstibonium cations catalyze cycloadditions between epoxides and CO2 or isocyanate to produce oxazolidinones.
Lewis acidic antimony compounds can act as Z-type ligands. Owing to the strong σ-accepting ability of dicationic Sb ligand, a gold-antimony complex can catalyze styrene polymerization and hydroamination after being activated by AgNTf2.
See also
Antimony
Organoantimony chemistry
Superacid
References
Pnictogens
Anions
Chemistry | Lewis acidic antimony compounds | [
"Physics",
"Chemistry"
] | 2,495 | [
"Ions",
"Matter",
"Anions"
] |
65,219,139 | https://en.wikipedia.org/wiki/Radium%20sulfate | Radium sulfate (or radium sulphate) is an inorganic compound with the formula RaSO4 and an average molecular mass of 322.088 g/mol. This white salt is the least soluble of all known sulfate salts. It was formerly used in radiotherapy and smoke detectors, but this has been phased out in favor of less hazardous alternatives.
Properties
Radium sulfate crystallizes in a solid in the same structure as barium sulfate. It forms crystals in the orthorhombic crystal system, with a unit cell of dimensions a = 9.13 b=5.54 and c = 7.31 Å. The unit cell volume is 369.7 Å3. Distance from the radium ion to oxygen is 2.96 Å and the sulfur to oxygen bond length in the sulfate ion is 1.485 Å. In this compound the ionic radius of the radium ion is 1.66 Å, and it is in ten coordination.
Radium sulfate can form solid solutions with the sulfates of strontium, barium or lead.
References
Radium compounds
Sulfates | Radium sulfate | [
"Chemistry"
] | 223 | [
"Sulfates",
"Salts"
] |
65,220,528 | https://en.wikipedia.org/wiki/Transcription-translation%20coupling | Transcription-translation coupling is a mechanism of gene expression regulation in which synthesis of an mRNA (transcription) is affected by its concurrent decoding (translation). In prokaryotes, mRNAs are translated while they are transcribed. This allows communication between RNA polymerase, the multisubunit enzyme that catalyzes transcription, and the ribosome, which catalyzes translation. Coupling involves both direct physical interactions between RNA polymerase and the ribosome ("expressome" complexes), as well as ribosome-induced changes to the structure and accessibility of the intervening mRNA that affect transcription ("attenuation" and "polarity").
Significance
Bacteria depend on transcription-translation coupling for genome integrity, termination of transcription and control of mRNA stability. Consequently, artificial disruption of transcription-translation coupling impairs the fitness of bacteria. Without coupling, genome integrity is compromised as stalled transcription complexes interfere with DNA replication and induce DNA breaks. Lack of coupling produces premature transcription termination, likely due to increased binding of termination factor Rho. Degradation of prokaryotic mRNAs is accelerated by loss of coupled translation due to increased availability of target sites of RNase E. It has also been suggested that coupling of transcription with translation is an important mechanism of preventing formation of deleterious R-loops. While transcription-translation coupling is likely prevalent across prokaryotic organisms, not all species are dependent on it. Unlike Escherichia coli, in Bacillus subtilis transcription significantly outpaces translation, and coupling consequently does not occur.
Mechanisms
Translation promotes transcription elongation and regulates transcription termination. Functional coupling between transcription and translation is caused by direct physical interactions between the ribosome and RNA polymerase ("expressome complex"), ribosome-dependent changes to nascent mRNA secondary structure which affect RNA polymerase activity (e.g. "attenuation"), and ribosome-dependent changes to nascent mRNA availability to transcription termination factor Rho ("polarity").
Expressome complex
The expressome is a supramolecular complex consisting of RNA polymerase and a trailing ribosome linked by a shared mRNA transcript. It is supported by the transcription factors NusG and NusA, which interact with both RNA polymerase and the ribosome to couple the complexes together. When coupled by transcription factor NusG, the ribosome binds newly synthesized mRNA and prevents formation of secondary structures that inhibit transcription. Formation of an expressome complex also aids transcription elongation by the trailing ribosome opposing back-tracking of RNA polymerase. Three-dimensional models of ribosome-RNA polymerase expressome complexes have been determined by cryo-electron microscopy.
Ribosome-mediated attenuation
Ribosome-mediated attenuation is a gene expression mechanism in which a transcriptional termination signal is regulated by translation. Attenuation occurs at the start of some prokaryotic operons at sequences called "attenuators", which have been identified in operons encoding amino acid biosynthesis enzymes, pyrimidine biosynthesis enzymes and antibiotic resistance factors. The attenuator functions via a set of mRNA sequence elements that coordinate the status of translation to a transcription termination signal:
A short open reading frame encoding a "leader peptide"
A transcription pause sequence
A "control region"
A transcription termination signal
Once the start of the leader open reading frame has been transcribed, RNA polymerase pauses due to folding of the nascent mRNA. This programmed arrest of transcription gives time for translation of the leader peptide to commence, and transcription to resume once coupled to translation. The downstream "control region" then modulates the elongation rate of either the ribosome or RNA polymerase. The factor determining this depends on the function of the downstream genes (e.g. the operon encoding enzymes involved in the synthesis of histidine contains a series of histidine codons is the control region). The role of the control region is to modulate whether transcription remains coupled to translation depending on the cellular state (e.g. a low availability of histidine slows translation leading to uncoupling, while high availability of histidine permits efficient translation and maintains coupling). Finally, the transcription terminator sequence is transcribed. Whether transcription is coupled to translation determines whether this stops transcription. The terminator requires folding of the mRNA, and by unwinding mRNA structures the ribosome elects the formation of either of two alternative structures: the terminator, or a competing fold termed the "antiterminator".
For amino acid biosynthesis operons, these allow the gene expression machinery to sense the abundance of the amino acid produced by the encoded enzymes, and adjust the level of downstream gene expression accordingly: transcription occurring only if the amino acid abundance is low and the demand for the enzymes is therefore high. Examples include the histidine (his) and tryptophan (trp) biosynthetic operons.
The term "attenuation" was introduced to describe the his operon. While it is typically used to describe biosynthesis operons of amino acids and other metabolites, programmed transcription termination that does not occur at the end of a gene was first identified in λ phage. The discovery of attenuation was significant as it represented a regulatory mechanism distinct from repression. The trp operon is regulated by both attenuation and repression, and was the first evidence that gene expression regulation mechanisms can be overlapping or redundant.
Polarity
"Polarity" is a gene expression mechanism in which transcription terminates prematurely due to a loss of coupling between transcription and translation. Transcription outpaces translation when the ribosome pauses or encounters a premature stop codon. This allows the transcription termination factor Rho to bind the mRNA and terminate mRNA synthesis. Consequently, genes that are downstream in the operon are not transcribed, and therefore not expressed. Polarity serves as mRNA quality control, allowing unused transcripts to be terminated prematurely, rather than synthesized and degraded.
The term "polarity" was introduced to describe the observation that the order of genes within an operon is important: a nonsense mutation within an upstream gene effects the transcription of downstream genes. Furthermore, the position of the nonsense mutation within the upstream gene modulates the "degree of polarity", with nonsense mutations at the start of the upstream genes exerting stronger polarity (more reduced transcription) on downstream genes.
Unlike the mechanism of attenuation, which involves intrinsic termination of transcription at well-defined programmed sites, polarity is Rho-dependent and termination occurs at variable position.
Discovery
The potential for transcription and translation to regulate each other was recognized by the team of Marshall Nirenberg, who discovered that the processes are physically connected through the formation of a DNA-ribosome complex. As part of the efforts of Nirenberg's group to determine the genetic code that underlies protein synthesis, they pioneered the use of cell-free in vitro protein synthesis reactions. Analysis of these reactions revealed that protein synthesis is mRNA-dependent, and that the sequence of the mRNA strictly defines the sequence of the protein product. For this work in breaking in the genetic code, Nirenberg was jointly awarded the Nobel Prize in Physiology or Medicine in 1968. Having established that transcription and translation are linked biochemically (translation depends on the product of transcription), an outstanding question remained whether they were linked physically - whether the newly synthesized mRNA released from the DNA before it is translated, or if can translation occur concurrently with transcription. Electron micrographs of stained cell-free protein synthesis reactions revealed branched assemblies in which strings of ribosomes are linked to a central DNA fibre. DNA isolated from bacterial cells co-sediment with ribosomes, further supporting the conclusion that transcription and translation occur together. Direct contact between ribosomes and RNA polymerase are observable within these early micrographs. The potential for simultaneous regulation of transcription and translation at this junction was noted in Nirenberg's work as early as 1964.
References
Gene expression
RNA | Transcription-translation coupling | [
"Chemistry",
"Biology"
] | 1,656 | [
"Gene expression",
"Molecular genetics",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
65,220,906 | https://en.wikipedia.org/wiki/Alpha%20beta%20barrel | An alpha/beta barrel is a protein fold formed by units composed of a short α-helix followed by two anti-parallel β-strands, followed by an α-helix and a β-strand; the three β-strands form a β-sheet that runs parallel to the barrel and the α-helix is in the outside of the barrel but does not contact the α-helices of the other repeats like in TIM barrels.
The protein structures known for this fold come proteins from the eukaryotic and archaeal initiation factor 6 family, namely the Methanococcus jannaschii aIF6 and Saccharomyces cerevisiae eIF6, and from the eIF6 from Dictyostelium discoideum.
These alpha/beta barrels are commonly occurring motifs constructed from repetitions of the beta-alpha-beta loop motif. This alpha/beta barrel is a domain of pyruvate kinase enzyme.
References
Protein structure
Protein folds
Protein tandem repeats
Protein domains | Alpha beta barrel | [
"Chemistry",
"Biology"
] | 205 | [
"Protein tandem repeats",
"Protein classification",
"Protein domains",
"Structural biology",
"Protein structure"
] |
65,221,049 | https://en.wikipedia.org/wiki/Technetium%28III%29%20chloride | Technetium trichloride is an inorganic compound of technetium and chlorine with the formula TcCl3.
Preparation and properties
Two polymorphs of technetium trichloride are known. The α-polymorph is prepared as a black solid from ditechnetium(III) tetraacetate dichloride and hydrogen chloride at 300 °C. It has a bioctahedral structure, consisting of triangular Tc3Cl9 units with C3v symmetry, with each Tc atom coordinated to two Tc neighbors and five chloride ligands (Tc-Tc bond length 2.44 angstrom). The Tc-Tc distances are indicative of double bonded Tc atoms. Tc3Cl9 is isostructural to its rhenium homologue, trirhenium nonachloride.
β-TcCl3 is obtained by the reaction between technetium metal and chlorine gas. Its structure consists of infinite layers of edge-sharing octahedra, similar to MoCl3 and ReCl3, with distances that also indicate metal-metal bonding. It is less stable than α-TcCl3 and slowly transforms into it.
References
Technetium compounds
Metal halides
Chlorides | Technetium(III) chloride | [
"Chemistry"
] | 254 | [
"Chlorides",
"Inorganic compounds",
"Metal halides",
"Salts"
] |
65,221,847 | https://en.wikipedia.org/wiki/Oiticica%20oil | Oiticica oil is a light-yellowish oil obtained from the seeds of oiticica tree (Microdesmia rigida) which grows mainly in Brazil.
Extraction and appearance
Oiticica oil is generally obtained from the kernels by crushing, pressing and expelling at high temperatures (210-220 °C) to prevent its polymerization. The raw oil is yellowish, turning brown after oxidation. It has also an unpleasant smell and taste, which limits its use in food and cosmetics applications.
Usage
Oiticica oil is used in industrial oil paints and varnishes as a substitute for tung oil, either alone or mixed with linseed oil and sesame oil to achieve even better results.
Composition
The fat components of oiticica oil are polyunsaturated α-licanic acid (46 – 78% of total), saturated fat mainly palmitic and stearic acids (together, 11%), monounsaturated as oleic acid (4 – 12%).
References
Waxes
Vegetable oils
Cosmetics chemicals | Oiticica oil | [
"Physics"
] | 211 | [
"Materials",
"Matter",
"Waxes"
] |
65,221,944 | https://en.wikipedia.org/wiki/O-mustard | O-mustard (T) is a vesicant chemical weapon, a type of mustard gas, with around three times the toxicity of the original sulfur mustard. It was developed in England in the 1930s as a thickener for mustard gas to make it more persistent when used in warm climates. A mixture of 60% sulfur mustard and 40% O-mustard also has a lower freezing point than pure sulfur mustard, and was given the code name HT. O-mustard is a Schedule I substance under the Chemical Weapons Convention.
See also
Bis(chloromethyl) ether
HN3 (nitrogen mustard)
Lewisite
Selenium mustard
Sesquimustard
References
Sulfur mustards
Blister agents
Chloroethyl compounds | O-mustard | [
"Chemistry"
] | 151 | [
"Blister agents",
"Chemical weapons"
] |
65,223,554 | https://en.wikipedia.org/wiki/Ridge%20function | In mathematics, a ridge function is any function that can be written as the composition of an univariate function , that is called a profile function, with an affine transformation, given by a direction vector with shift .
Then, the ridge function reads
for .
Coinage of the term 'ridge function' is often attributed to B.F. Logan and L.A. Shepp.
Relevance
A ridge function is not susceptible to the curse of dimensionality, making it an instrumental tool in various estimation problems. This is a direct result of the fact that ridge functions are constant in directions:
Let be independent vectors that are orthogonal to , such that these vectors span dimensions.
Then
for all .
In other words, any shift of in a direction perpendicular to does not change the value of .
Ridge functions play an essential role in amongst others projection pursuit, generalized linear models, and as activation functions in neural networks. For a survey on ridge functions, see. For books on ridge functions, see.
References
Functions and mappings | Ridge function | [
"Mathematics"
] | 204 | [
"Mathematical analysis",
"Functions and mappings",
"Mathematical relations",
"Mathematical objects"
] |
65,223,668 | https://en.wikipedia.org/wiki/Ernest%20Harold%20Baynes | Ernest Harold Baynes (1868–1925) was an American naturalist and writer. He was instrumental in bringing to public attention the near demise of songbirds and of the bison. He founded the American Bison Society, of which President Teddy Roosevelt was honorary chairman. He was "the closest thing New England, and the world for that matter, will ever get to a real-life Doctor Dolittle; all sorts of New England birds and animals–foxes, wolves, chickadees, bears and bison were known to roam around and in and out of his house."
Origins
He was born on 1 May 1868 at Calcutta, West Bengal in India, a son of John Baynes a British inventor, by his wife Helen Augusta Nowill Baynes In the 1870s, after his father had failed at running a textiles company in Calcutta, the family moved to New York, where John set up the Baynes Tracery and Mosaic Co., which produced etched memorial tablets, among other products. He patented manufacturing processes with the tastemaker Lockwood de Forest, and Baynes tablets survive at Grace Church in Newark, the Battell Chapel and Norfolk Library in Norfolk, Connecticut, and the Cleveland Soldiers' and Sailors' Monument. John claimed (without proof) to have invented "photo-modeling", a technique for using light to carve sculpture. Ernest's siblings included Lillian Baynes Griffin, a British-born American journalist and photographer, and John R. Baynes, a metal etcher and photographer.
Career
He received his early education in England and aged 11 moved with his parents to Bronx Park, New York. He graduated as valedictorian of his high school class and subsequently attended the College of the City of New York. In the 1890s he started publishing articles on nature and wildlife in various newspapers. "Without the constraints of scholarly publishing, he became a wildlife showman through his articles and appearances."
Bison conservation
In 1904 he was appointed conservator of the Corbin Park buffalo reserve on the edge of the Blue Mountain Forest in New Hampshire, by Austin Corbin Jr. (d.1938), whose father the banker and railroad entrepreneur Austin Corbin (1827-1896) had established it. Known as the "Blue Mountain Forest Association", it was a limited membership proprietary hunting club, the park of which comprised in the towns of Cornish, Croydon, Grantham, Newport and Plainfield. Corbin Sr. imported bison from Oklahoma, Montana, Wyoming, Manitoba and Texas and donated bison to other American zoos and preserves. He also imported exotic species from Europe and Canada, including wild boar from the Black Forest of Germany. Having been purchased by a syndicate of hunters in 1944, the park survives in 2020, surrounded by a chain-link fence, as a non-profit organization with a membership of about 30 wealthy game hunters, and is referred to as the "millionaires hunt club", said to be "the most exclusive game preserve in the United States". The herd of bison, however, was destroyed in the 1940s following an outbreak of brucellosis, and the main species preserved and hunted are elk and boar.
From a natural level of 60 million in America, the bison population had been reduced by human activity to just 1,000 by the 1890s, and in 1904 160 of these animals lived within Corbin Park. In about 1906 Baynes conducted a survey into surviving numbers of American bison, and found that 2,039 existed, 325 in the wild (25 in the USA, 300 in Canada), and 1,714 in captivity (1,109 in the USA, 175 in Canada and 130 in Europe, 300 elsewhere). After 15 years of work and campaigning by Baynes, the national bison herd had increased to 20,000. He was famous for his tame bison and for driving around the park in a carriage pulled by a pair of bison War Whoop and Tomahawk, trained by him in an effort to promote the usefulness of the breed as draught animals. Baynes commented, "Of all the works of the late Mr. Austin Corbin, the preservation of that herd of bison was the one that would earn his country's deepest gratitude. His experiment led to the founding of the American Bison Society and was connected, directly or otherwise, with the formation of some of our national parks."
Bird conservation
He campaigned against wild birds being killed for their plumage. In 1913 he established one of the earliest bird sanctuaries (the Meriden Bird Club) at his home at Meriden, New Hampshire, which occasion was marked by a play being performed there in 1914 written by poet Percy MacKaye and called Sanctuary: A Bird Masque, with actors dressed in bird costumes, including Baynes himself in the role of "Shy, the Naturalist". Amongst the audience was President Woodrow Wilson. Baynes' activity is believed to have maintained the political appetite to ban the importation of bird feathers, included within the Underwood Tariff bill then being debated in Congress. The play was performed across the country and helped to fuel the bird-protection movement developing in the 1910s.
Vivisection
Baynes investigated vivisection and the claims of anti-vivisectionists. He visited laboratories where experiments were carried out and came to the unexpected conclusion that little pain had been inflicted on the animals which he believed was insignificant in comparison to the relief from pain the research had given humans.
He authored the article "The Truth about Vivisection" for the Woman's Home Companion in July, 1921. In this article, Baynes supported vivisection and critiqued the arguments of anti-vivisectionists. Baynes publicly declared himself a supporter of vivisection which caused great controversy. He was attacked by anti-vivisection organizations as a fake humanitarian and a supporter of animal cruelty. Baynes received much abusive mail from a threatening nature. Walter Hadwen for the American Anti-Vivisection Society wrote a rebuttal to Baynes' article, stating it was filled with misinformation. However, Baynes received support from W. W. Keen, Henry Cantwell Wallace, Frederic Augustus Lucas and many other academics and doctors.
Baynes defended vivisection for developing methods of disease prevention. In 1923, he authored a pamphlet Vivisection and Modern Miracles.
Death
He died aged 56 on January 21, 1925, at his home "Sunset Ridge", Meriden, Sullivan County, New Hampshire, US. His ashes were scattered on Croydon Mountain near his home, which event is commemorated on a local monument inscribed: Here were scattered the ashes of Ernest Harold Baynes, lover of animals and men, and loved of them. May 1, 1868, January 21, 1925.
In Popular Culture
Earnest Harold Baynes appears in Annie Hartnett's novel, Unlikely Animals. Also going by Harold, he appears as a ghost to the protagonist Emma Starling's father, Clive. His writings depicting relationships with the animals in his home also appear frequently, symbolizing a new section of the novel.
Selected publications
Wild Bird Guests: How to Entertain Them (1915)
The Truth About Vivisection (1921)
Polaris, the Story of an Eskimo Dog (1922)
Vivisection and Modern Miracles (1923)
The Sprite: The Story of a Red Fox (1924)
The Book of Dogs: An Intimate Study of Mankind's Best Friend (with Louis Agassiz Fuertes)
Animal Heroes of the Great War (1925)
Three Young Crows, and Other Bird Stories (1927)
Jimmie: The Story of a Black Bear Cub (1929)
War Whoop and Tomahawk: The Story of Two Buffalo Calves (1929)
Wild Life in the Blue Mountain Forest, revised and edited by Raymond Gorges, foreword by Austin Corbin, with illustrations from photographs by the author and Louise Birt Baynes (1931).
References
Further reading
1868 births
1925 deaths
19th-century American naturalists
20th-century American naturalists
American conservationists
American nature writers
American male non-fiction writers
Vivisection activists
British people in colonial India
British emigrants to the United States | Ernest Harold Baynes | [
"Chemistry"
] | 1,637 | [
"Vivisection activists",
"Vivisection"
] |
65,225,457 | https://en.wikipedia.org/wiki/Elena%20Kazimirtchak-Polonska%C3%AFa | Olena Ivanivna Kazymyrchak-Polonska (21 November 1902 – 30 August 1992) was a Ukrainian astronomer and member of the International Astronomical Union, who studied the motion of comets and their orbital evolution. Asteroid 2006 Polonskaya was named in her honor.
Life
In 1928, she graduated from University of Lviv. In 1923, she participated in the first meeting of the Russian Student Christian Movement in Czechia. From 1926 to 1928 she was an active member of this movement and its leader for Poland and Belarus. She acted as editor of the religious political journal At the Borderline. She participated in apologetic summer courses in Paris founded by Archpriest Sergei Bulgakov, her spiritual father. From 1932 to 1934, she was an assistant at the Astronomical Observatory of the University of Warsaw.
In 1936, she married Leon Kazimierczak, an ichthyologist at Warsaw University, and in May 1937, their son Sergei (named after Sergei Bulgakov) was born. During World War II, she worked as senior scientist at the Department of Astronomy in Lviv and moved to Warsaw in 1944. During the Warsaw Uprising in 1944, she became separated from her husband who was brought to a camp near Vienna as war prisoner. In 1945, she made a very bold and crucial decision for her later life: As an Orthodox, she decided to return to Russia, although the Soviet Union was totalitarian at that time. She first lived in Kherson (in today's Ukraine) where her son died of meningitis in July 1948.
From 1945, she taught mathematics and astronomy at the Kherson State University. In 1948, she became a researcher, then a senior researcher at the Institute of Theoretical Astronomy of the Academy of Sciences of the Soviet Union. In November 1951, she was dismissed from work. In 1952, due to her religious belief and missionary activities, she was arrested on suspicion of "espionage", and held from January to August, by the USSR State Security Committee. She was acquitted and released.
From 1953 to 1956 she was an associate professor at the Department of Higher Mathematics of the K. D. Ushynsky South Ukrainian National Pedagogical University. In 1964 she became a member of the International Astronomical Union. From 1967 to 1985, she helped organize All-Union and international astronomical seminars and symposia. From 1976 to 1978, she was the head of the scientific group on the dynamics of small bodies at the Astronomical Council of the Academy of Sciences of the Soviet Union. Polonskaïa studied in-depth the Leonids, a prolific meteor shower.
In 1970, Elena became an active member Polish–Soviet Friendship Society and in 1972, an honorary member of the USSR Institute of Blind People; in particular, she participated in the publication of works in mathematics and programming in Braille script. In the years after 1970, she organized in her home two secret circles for working with young people and adults, reading the gospels and lecturing on apologetics, patristics, history of the Church and various other theological topics.
In the 1980s, she took religious vows and became a nun choosing the path of "monasticism in the world". She worked on the biblical studies and the history of the Russian Church, writing original works and translations. She was fluent in Polish, French and German. In her last years, she almost completely lost her eyesight but, having an excellent memory, she gave a series of lectures on the life and work of Archpriest Sergey Bulgakov. She died on 30 August 1992. She was buried in the cemetery of astronomers at the Pulkovo Observatory.
Awards and honors
In 1969, she won the for her research on short period comets and their orbital evolution.
Asteroid 2006 Polonskaya, discovered by Nikolai Chernykh at the Crimean Astrophysical Observatory on 22 September 1973, was named after her. The official was published by the Minor Planet Center on 1 September 1978 ().
References
1902 births
1992 deaths
Astrometry
University of Lviv alumni
Academic staff of the University of Warsaw
Academic staff of K. D. Ushinsky South Ukrainian National Pedagogical University | Elena Kazimirtchak-Polonskaïa | [
"Astronomy"
] | 836 | [
"Astrometry",
"Astronomical sub-disciplines"
] |
65,225,861 | https://en.wikipedia.org/wiki/Dicke%20model | The Dicke model is a fundamental model of quantum optics, which describes the interaction between light and matter. In the Dicke model, the light component is described as a single quantum mode, while the matter is described as a set of two-level systems. When the coupling between the light and matter crosses a critical value, the Dicke model shows a mean-field phase transition to a superradiant phase. This transition belongs to the Ising universality class and was realized in cavity quantum electrodynamics experiments. Although the superradiant transition bears some analogy with the lasing instability, these two transitions belong to different universality classes.
Description
The Dicke model is a quantum mechanical model that describes the coupling between a single-mode cavity and two-level systems, or equivalently spin-1/2 degrees of freedom. The model was first introduced in 1973 by K. Hepp and E. H. Lieb. Their study was inspired by the pioneering work of R. H. Dicke on the superradiant emission of light in free space and named after him.
Like any other model in quantum mechanics, the Dicke model includes a set of quantum states (the Hilbert space) and a total-energy operator (the Hamiltonian). The Hilbert space of the Dicke model is given by (the tensor product of) the states of the cavity and of the two-level systems. The Hilbert space of the cavity can be spanned by Fock states with photons, denoted by . These states can be constructed from the vacuum state using the canonical ladder operators, and , which add and subtract a photon from the cavity, respectively. The states of each two-level system are referred to as up and down and are defined through the spin operators , satisfying the spin algebra . Here is the reduced Planck constant and indicates a specific two-level system.
The Hamiltonian of the Dicke model is
Here, the first term describes the energy of the cavity and equals to the product of the energy of a single cavity photon (where is the cavity frequency), times the number of photons in the cavity, . The second term describes the energy of the two-level systems, where is the energy difference between the states of each two-level system. The last term describes the coupling between the two-level systems and the cavity and is assumed to be proportional to a constant, , times the inverse of the square root of the number of two-level systems. This assumption allows one to obtain a phase transition in the limit of (see below). The coupling can be written as the sum of two terms: a co-rotating term that conserves the number of excitations and is proportional to and a counter-rotating term proportional to , where are the spin ladder operators.
The Hamiltonian in Eq. assumes that all the spins are identical (i.e. have the same energy difference and are equally coupled to the cavity). Under this assumption, one can define the macroscopic spin operators , with , which satisfy the spin algebra, . Using these operators, one can rewrite the Hamiltonian in Eq. as
This notation simplifies the numerical study of the model because it involves a single spin-S with , whose Hilbert space has size , rather than spin-1/2, whose Hilbert space has size .
The Dicke model has one global symmetry,
Because squares to unity (i.e. if applied twice, it brings each state back to its original state), it has two eigenvalues, and . This symmetry is associated with a conserved quantity: the parity of the total number of excitations, , where
This parity conservation can be seen from the fact that each term in the Hamiltonian preserves the excitation number, except for the counter-rotating terms, which can only change the excitation number by . A state of the Dicke model is said to be normal when this symmetry is preserved, and superradiant when this symmetry is spontaneously broken.
Related models
The Dicke model is closely related to other models of quantum optics. Specifically, the Dicke model with a single two-level system, , is called the Rabi model. In the absence of counter-rotating terms, the model is called Jaynes-Cummings for and Tavis-Cummings for . These two models conserve the number of excitations and are characterized by a symmetry. The spontaneous breaking of this symmetry gives rise to a lasing state (see below).
The relation between the Dicke model and other models is summarized in the table below
Superradiant phase transition
Early studies of the Dicke model considered its equilibrium properties. These works considered the limit of (also known as the thermodynamic limit) and assumed a thermal partition function, , where is the Boltzmann constant and is the temperature. It was found that, when the coupling crosses a critical value , the Dicke model undergoes a second-order phase transition, known as the superradiant phase transition.
In their original derivation, Hepp and Lieb neglected the effects of counter-rotating terms and, thus, actually considered the Tavis-Cummings model (see above). Further studies of the full Dicke model found that the phase transition still occurs in the presence of counter-rotating terms, albeit at a different critical coupling.
The superradiant transition spontaneously breaks the parity symmetry, , defined in Eq. . The order parameter of this phase transition is . In the thermodynamic limit, this quantity tends to zero if the system is normal, or to one of two possible values, if the system is superradiant. These two values correspond to physical states of the cavity field with opposite phases (see Eq. and, correspondingly, to states of the spin with opposite components). Close to the superradiant phase transition, the order parameter depends on as . This dependence corresponds to the mean-field critical exponent .
Mean-field description of the transition
The simplest way to describe the superradiant transition is to use a mean-field approximation, in which the cavity field operators are substituted by their expectation values. Under this approximation, which is exact in the thermodynamic limit, the Dicke Hamiltonian of Eq. becomes a sum of independent terms, each acting on a different two-level system, which can be diagonalized independently. At thermal equilibrium (see above), one finds that the free energy per two-level system is
The critical coupling of the transition can be found by the condition , leading to
For , has one minimum, while for , it has two minima. In the limit of one obtains an expression for the critical coupling of the zero-temperature superradiant phase transition, .
Semiclassical limit and chaos
Semiclassical limit
A phase space for the Dicke model in the symmetric atomic subspace with may be constructed by considering the tensor product of the Glauber coherent states
where is the displacement operator and is the photon vacuum Fock state, and the SU(2) coherent states
where is the rotation operator in the Bloch sphere, and is the state with all atoms in their ground state. This yields a four-dimensional phase space with canonical coordinates and .
A classical Hamiltonian is obtained by taking the expectation value of the Dicke Hamiltonian given by Eq. under these states,
In the limit of , the quantum dynamics given by the quantum Hamiltonian of Eq. and the classical dynamics given by Eq. coincide. For a finite system size, there is a classical and quantum correspondence that breaks down at the Ehrenfest time, which is inversely proportional to .
Quantum chaos
The Dicke model provides an ideal system to study the quantum-classical correspondence and quantum chaos.
The classical system given by Eq. is chaotic or regular depending on the values of the parameters , , and and the energy . Note that there may be chaos in both the normal and superradiant regimes.
It was recently found that the exponential growth rate of the out-of-time-order correlator coincides with the classical Lyapunov exponents in the chaotic regime and at unstable points of the regular regime. In addition, the evolution of the survival probability (i.e. the fidelity of a state with itself at a later time) of initial coherent states highly delocalized in the energy eigenbasis is well-described by random matrix theory, while initial coherent states strongly affected by the presence of quantum scars display behaviors that break ergodicity.
Open Dicke model
The Dicke model of Eq. assumes that the cavity mode and the two-level systems are perfectly isolated from the external environment.
In actual experiments, this assumption is not valid: the coupling to free modes of light can cause the loss of cavity photons and the decay of the two-level systems (i.e. dissipation channels).
It is worth mentioning, that these experiments use driving fields (e.g. laser fields) to implement the coupling between the cavity mode and the two-level systems.
The various dissipation channels can be described by adding a coupling to additional environmental degrees of freedom.
By averaging over the dynamics of these external degrees of freedom one obtains equations of motion describing an open quantum system.
According to the common Born-Markov approximation, one can describe the dynamics of the system with the quantum master equation in Lindblad form
Here, is the density matrix of the system, is the Lindblad operator of the decay channel , and the associated decay rate. When the Hamiltonian is given by Eq. , the model is referred to as the open Dicke model.
Some common decay processes that are relevant to experiments are given in the following table:
In the theoretical description of the model, one often considers the steady state where . In the limit of , the steady state of the open Dicke model shows a continuous phase transition, often referred to as the nonequilibrium superradiant transition. The critical exponents of this transition are the same as the equilibrium superradiant transition at finite temperature (and differ from the superradiant transition at zero temperature).
Superradiant transition and Dicke superradiance
The superradiant transition of the open Dicke model is related to, but differs from, Dicke superradiance.
Dicke superradiance is a collective phenomenon in which many two-level systems emit photons coherently in free space. It occurs if the two-level systems are initially prepared in their excited state and placed at a distance much smaller than the relevant photon's wavelength. Under these conditions, the spontaneous decay of the two-level systems becomes much faster: the two-level systems emit a short pulse of light with large amplitude. Under ideal conditions, the pulse duration is inversely proportional to the number of two-level systems, , and the maximal intensity of the emitted light scales as . This is in contrast to the spontaneous emission of independent two-level systems, whose decay time does not depend on and where the pulse intensity scales as .
As explained above, the open Dicke model rather models two-level systems coupled to a quantized cavity and driven by an external pump. In the normal phase, the intensity of the cavity field does not scale with the number of atoms , while in the superradiant phase, the intensity of the cavity field is proportional to .
The scaling laws of Dicke superradiance and of the superradiant transition of the Dicke model are summarized in the following table:
Experimental realizations
The simplest realization of the Dicke model involves the dipole coupling between two-level atoms in a cavity. In this system, the observation of the superradiant transition is hindered by two possible problems: (1) The bare coupling between atoms and cavities is usually weak and insufficient to reach the critical value , see Eq. . (2) An accurate modelling of the physical system requires to consider terms that according to a no-go theorem, may prevent the transition. Both limitations can be circumvented by applying external pumps on the atoms and creating an effective Dicke model in an appropriately rotating frame.
In 2010, the superradiant transition of the open Dicke model was observed experimentally using neutral Rubidium atoms trapped in an optical cavity.
In these experiments, the coupling between the atoms and the cavity is not achieved by a direct dipole coupling between the two systems.
Instead, the atoms are illuminated by an external pump, which drives a stimulated Raman transition.
This two-photon process causes the two-level system to change its state from down to up, or vice versa, and emit or absorb a photon into the cavity.
Experiments showed that the number of photons in the cavity shows a steep increase when the pump intensity crosses a critical threshold.
This threshold was associated with the critical coupling of the Dicke model.
In the experiments, two different sets of physical states were used as the down and up states. In some experiments, the two states correspond to atoms with different velocities, or momenta: the down state had zero momentum and belonged to a Bose-Einstein condensate, while the up state had a momentum equal to sum of the momentum of a cavity photon and the momentum of a pump photon. In contrast, later experiments used two different hyperfine levels of the Rubidium atoms in a magnetic field. The latter realization allowed the researchers to study a generalized Dicke model (see below). In both experiments, the system is time-dependent and the (generalized) Dicke Hamiltonian is realized in a frame that rotates at the pump's frequency.
Generalized model and lasing
The Dicke model can be generalized by considering the effects of additional terms in the Hamiltonian of Eq. . For example, a recent experiment realized an open Dicke model with independently tunable rotating and counter-rotating terms. In addition to the superradiant transition, this generalized Dicke model can undergo a lasing instability, which was termed inverted lasing or counter-lasing. This transition is induced by the counter-rotating terms of the Dicke model and is most prominent when these terms are larger than the rotating ones.
The nonequilibrium superradiant transition and the lasing instability have several similarities and differences. Both transitions are of a mean-field type and can be understood in terms of the dynamics of a single degree of freedom. The superradiant transition corresponds to a supercritical pitchfork bifurcation, while the lasing instability corresponds to a Hopf instability. The key difference between these two types of bifurcations is that the former gives rise to two stable solutions, while the latter leads to periodic solutions (limit cycles). Accordingly, in the superradiant phase the cavity field is static (in the frame of the pump field), while it oscillates periodically in the lasing phase.
See also
Jaynes–Cummings model
Superradiance
Superradiant phase transition
Cavity quantum electrodynamics
Open quantum system
Lasing
Dicke state
References
Quantum optics | Dicke model | [
"Physics"
] | 3,099 | [
"Quantum optics",
"Quantum mechanics"
] |
65,226,368 | https://en.wikipedia.org/wiki/Noffkarkys | Noffkarkys ("net of Noffke") is a genus of problematic fossil first found in the Ediacaran (550 million years old) Grant Bluff Formation of Central Mount Stuart, Northern Territory, Australia, and another prostrate frond-like fossil. The genus was named in honor of Nora Noffke.
Description
Noffkarkys is an Ediacaran fossil frond with a fine pattern of rhombic quilts radiating from the base which does not include a rounded holdfast. Like other Ediacaran frond such as Trepassia which also lacks a holdfast, Noffkarkys may have lived prone on the substrate. The fine quilting extends deep into the matrix from the upper side as seen in petrographic thin sections.
Biological affinities
Noffkarkys is a problematic fossil like many Ediacaran genera, and is one of the few vendobionts that persisted into the Cambrian Affinities may be with sea pens or lichens.
References
Ediacaran life
Fossil taxa described in 2020
Controversial taxa | Noffkarkys | [
"Biology"
] | 222 | [
"Biological hypotheses",
"Controversial taxa"
] |
65,226,978 | https://en.wikipedia.org/wiki/Slavic%20creation%20myth | The Slavic creation myth is a cosmogonic myth in Slavic mythology that explains how the world was created, who created it, and what principles guide it. This myth, in its Christianized form, survived until the nineteenth and twentieth century in various parts of the Slavdom in chronicles or folklore. In the Slavic mythology there are three versions of this myth: the first version is the so-called earth-diver myth, which intertwines two main motifs: the dualistic motif – the cooperation of God and the Devil (that is, the "good god" and the "bad god") is required to create the world, and the oceanic motif – the pre-existence water, where the seed of the Earth comes from; the second version speaks about the origin of the universe and the world from the Cosmic Egg and the World Tree; the third one about creation from a dismemberment of a primordial being.
Creation of the world
Creation by diving
The myth that has been preserved from Poland comes from the Sieradz Land and was written down in 1898:
In the Russian and Ukrainian variants, the devil retains some of the sand created under the tongue, and when the Earth begins to grow, the sand bursts out his mouth. This myth was written by the Russian slavist Alexander Afanasyev, who was one of the first researchers to study Russian folklore in 1859:
The dualistic creation myth by "evil god" diving has 24 credentials in Balto-Slavic areas and 12 credentials in Finno-Ugric areas. The Bulgarian myth does not mention the Devil's catastrophe, but it develops the theme of creation by the formula "by God's and my power", and the Devil, who twice reversed the order of the formula, could not reach the bottom until the third time he pronounced the formula correctly, reached the bottom.
The Moldavian variant also ends with the expansion of the Earth and the Transylvanian Romani extended the dualistic motif by punishing the devil by the bull and the Tree of Life, from which the people were formed. Only in a myth from Slovenia God goes to the bottom of the waters on His own. In another version of the myth, the Devil tries to push God into the sea to become the only creator – first he pushes him east, then west, south and north, but the land always expands. Annoyed by this fact, the Devil awakens God and tells him that it is time to bless the Earth, since it has grown so big. God suits him: "Once you carried me four ways to the water to throw me into it, you drew a cross with me, and this is how I blessed the earth myself." Then God goes to the Heavens and Devil, who attacked him, was thrown down into the abyss by lightning.
Seemingly, the consecration of the earth seems to be a Christian motif, but this motif is used in myths to set directions and exists in other mythologies: according to the Maidu, the Earth Maker descended into the cosmic center of the world and there he met a Coyote (a trickster figure), who after the creation of the world went to sleep. The Earth Maker stretched the Earth from the south, through the west, to the north, and when the Coyote woke up, he stretched the Earth to the east. When the Earth Maker was left alone, he went around the Earth, staggering a full circle, fixing (in one version of the myth) the Earth to cardinal directions with stone hooks. For some Indian tribes, therefore, determining the directions of the world is a religious activity and for this reason, the Mexican Huicholas interpret Christian sign of the cross as an imitation of the Indian myth. For the Slavs, therefore, "consecration to the Earth" is the structuring of the universe and the designation of the directions of the Earth, and the extension of the point state "to infinity". Yet another myth says that the Earth grows all the time and God, who is left alone, does not know how to stop it. So God sends a bee to overhear the Devil. The Devil, laughing at God, says to himself: a stupid God does not know that you have to take some stick, draw the sign of the cross and say "Enough of this Earth!" When the Devil saw a bee running away on his shoulder, he tried to catch it, but it ran away from him, so he cursed her master: "May he who sent you here eat your dung," and God, who heard this, ordered the bee to produce honey from now on. A myth from Dobrzyń Land says that the Devil tells the duck to steal some earth from God, and when she was returning with the earth in her beak, she was captured by a hawk, who started choking her, and from the earth that fell out of her beak, mountains were created. For the creation of the world or of a being, the cooperation of God and the Devil is always required, who are endowed with equal power.
Researchers also identify Slavic gods who hide under the Christian terms God and Devil. The Slavic word for God Bog or Boh was used by Christian missionaries as an equivalent of the Latin Deus and the Greek Theos because it corresponded meaningfully to the notion of a supernatural being, but in the Slavic religion, Bog always appears in compound names, i.e. Daž-bog, Stri-bog, Cherno-bog, or in names i.e. Boži-dar, Bohu-mil, Bogu-slav, etc., so most probably God was not a proper name for the figure mentioned in the myths of creation. When interpreting the figure of God, the text of Procopius on the religion of the Slavs may be helpful:
, analyzing the folk image of the Christian God, indicates that God sits in heaven, sends rains in anger, shoots lightning at evil spirits, rules predatory animals and fate. These features indicate a god-thunderer, and therefore most likely Perun was replaced by God. Perun is one of the oldest Indo-European gods and is descended from the Proto-Indo-European storm god *perkʷunos. His name probably means literally the "Striking One" (compare Proto-Slavic *pьrati - "to beat, to hit"). The core *perkʷ means oak (cf. Latin querqus - "oak") - a sacred tree dedicated to Perun. In Ruthenian chronicles, he is presented as gray-haired, which would distinguish him from the Celtic Taranis, Germanic Thor or Hindu Indra as war gods, and made him resemble Roman Jupiter and Greek Zeus as rulers. However, according to some researchers, such as Henryk Łowmiański, the description of God rather points to Svarog. The Devil is interpreted as Veles, the god of the underworld. In Primary Chronicle, the Ruthenians, when making an alliance with the Greeks, swear on Perun and Veles, which may suggest that Veles' power was comparable to that of Perun. In Polish (and in some other Slavic languages too), just as Perun (Piorun) was devalued to the piorun "lightning", so Veles was devalued to the veles "devil, demon" in Czech. In South Slavic folklore, St. Elijah, the Christianized Perun, is often opposed to St. Nicholas, the Christianized Veles. The creation myth also fits Chernobog (lit. "Black God") and Belobog (lit. "White God"), who were to be worshiped by the Polabian Slavs:
This myth may come from some ancient substrate, perhaps pre-European, assimilated by the Slavs and subjected to further transformations. This myth could also be perpetuated under the influence of the Persian antithetical couple Ahura Mazda and Ahriman, who left their mark in various syncretic religions. Bogomil's influence was also suggested: the followers of this religion claimed that the main drama of creation was the conflict between two brothers: the older Satanael (the suffix -el adds the divine element to Devil) and the younger Jesus (Savaof – the Word = Logos-Christ) – Satanael created the world and man, and God sent him the Word in the form of Jesus to save them. In the 16th century Legend of the Tiberian Sea, God, when he hovered over the water, saw Satanael as a water bird and ordered him to dive into the sea. According to the critics of this theory, it has serious shortcomings: the full text of this myth does not appear in any Bogomil texts, and this myth does not exist in areas dominated by Bogomilism, also in Western Europe, where the Cathars influenced the local folklore. This myth, however, existed in the territories of Poland, Ukraine and Belarus, where the Bogomil faith never reached.
Creation from the Cosmic Egg
The myth in which the creation of the world from the Cosmic Egg or World Egg can be found in the Carpathian carol also written down by Afanasayev:
This carol contains three elements: the first one is two pigeons sitting on an oak tree, the second one is the catching of sand and stones by birds, the third is the creation of the world. Two pigeons, birds, hens or bees sitting in the crown of the tree is a popular motif among the Slavs – it represents the World Tree. In folklore, the World Tree stands in the "navel of the world", it is supposed to be heavy, tall and with a wide leaf. In a similar preserved myth, God throws his staff into the water, which then changes into a tree. On its branch, God and the Devil sit down to take the world out of the water. The relationship of this prayer with the World Egg is indicated by the "fine sand" from which the "black earth" and the "blue stones" from which the heaven and the celestial objects are made. This corresponds to the widespread myths of the Cosmic Egg, which is broken down in the creative act, and from whose lower shell the Earth is formed, and from whose upper shell the Heavens are formed.
Vladimir Toporov also points to the existence of this myth in Russian fairy tales. In these fairy tales, the hero, looking for a princess, travels through three kingdoms, and after defeating three vipers, the kingdoms are reduced to three eggs.
Fairy-tale eggs are generally submerged in water and their extraction and breaking up creates a "kingdom" – a world in fairy tongue. Also, the triple of egg-kingdoms is not accidental – it corresponds to the tripartite division of the world in Indo-European mythologies into Heaven (Vyraj), Earth and the Underworld (Nav). In Dobrzyń Land, it was directly believed that the world was created from an egg lying on a giant tree and the story of the princess from the egg, which the prince was to marry, was preserved: she was tricked by a witch into a duck that was killed, whose blood then grew into an apple tree. From Slovenia the myth has survived, where God sends a rooster to Earth, who lays an egg from which seven rivers are poured:
There were also riddles in Poland that pointed to the egg: "There is a world. And in this world there is a yellow flower" or "There is a white world. And in this world a yellow flower".
Creation from dismemberment
Another kind of creation myth has survived: the creation of the world from a dismembered first human or another being. Polish scholar Stanislaw Schayer recalled the text from the Dove Book, which was a collection of oral stories of the clergy, the following story: a great book fell from heaven, in which the history of being was written; kings ask tsar David to read it, but the book is too big, but David, inspired by the Holy Spirit, will answer three questions; the first one concerns the creation of the world:
In four variants, the last three lines replace the text:
This myth is most likely not a Christian influence, but Slavic phraseology has been Christianized, probably under the influence of the apocryphal Book of Enoch, in which the same was done with the Iranian myth, which in turn could have been the source of the Russian myth. A similar motif is present in other Indo-European myths: in Hindu mythology a society was formed from the body of Purusha – the first man: Brahmins from the mouth, warriors from the shoulders, peasants from the hips, shudras from the feet; in Scandinavia this being was Ymir and in Iran Gayōmart.
Functioning of the world
The world is sustained by animals or fish. In the myth described by Afanasayev, the world is sustained by whales: at first there were seven of them, but three are gone and four are left. Then one died and three are left and therefore the world is crooked. A similar myth, where the fall of one of the "pillars of the world" causes a catastrophe, occurs, for example, in China. Such a decomposition of the original seven: 3 + 1 + 3 can testify to the multiplicity of worlds - three were before ours and three will be after ours. A similar motif exists among Hopi Indians or in the doctrine of the five worlds of Bambara. The world, in order not to break, is wrapped around it is the Zmiy or Zmiya (Viper). This can mean a constant threat from one of the creators. A similar theme exists in Nordic mythology (Jörmungandr).
The dome of the world was made of stone, sometimes of silicon, which explained the formation of lightning, or of blue gemstone, which is a symbol of the stated time. The dome, especially in the Western Slavs, was based on a "pillar". (a kind of Axis Mundi – Cosmic Tree) running from the Pole Star, which rotates the whole vault. The location of the contact between the pillar and the vault and the ground had specific characteristics: these places were called the zabka (frog) or sierdzeń (gudgeon pin), which is connected to the constellation of the Great and Little Wagon.
In the Slavs, the souls of the dead travelled to the Undergrounds via a bridge - at night it was the Milky Way and during the day it was a rainbow. In the materials collected by such a Milky Way is called the Way of the Soul, the Way of the [blue] Army and it was spilled with stardust. The other Axis Mundi connecting the worlds was the Tree of the Family, connected to the dziady – the deceased's name is also his identity, and it lasts until someone mentions his name, until his name is forgotten and he joins the nameless group of souls. The souls already in the afterlife return to Earth in the rays of the sun.
For the Slavs, Cosmic Trees could function as Cosmic Mountains. Mountains were often treated as magical places, temples were built on them or rituals were performed there. The mountains such as Ślęża, Kyiv Hill or Bald Mountain were especially popular, the Montenegrins called Durmitor mountain "the Blue Column", and the Slovaks considered Kriváň as a sacred mountain. In Kievan Rus' it was believed that "the high mountain of Triglav appeared first from the water".
References
Bibliography
Further reading
Slavic mythology
Creation myths | Slavic creation myth | [
"Astronomy"
] | 3,204 | [
"Cosmogony",
"Creation myths"
] |
65,227,440 | https://en.wikipedia.org/wiki/Likewise%2C%20Inc. | Likewise, Inc., is an American technology startup company which provides a social networking service for finding and saving content recommendations for movies, TV shows, books, and podcasts. A team of ex-Microsoft employees founded Likewise in October 2017 with financial investment from Microsoft co-founder Bill Gates.
The company is led by CEO Ian Morris and now has a team of about 35 employees. Its headquarters operates in Bellevue, Washington. As of July 2020, 1 million users have joined the platform.
History
Ideation (October 2017)
In 2017, former Microsoft Communications Chief Larry Cohen came up with the idea for Likewise in Bill Gates’ private office, Gates Ventures. Cohen currently serves as Gates Ventures’ CEO and managing partner.
Cohen collaborated with colleagues Michael Dix and Ian Morris to co-found what would become Likewise, with Morris as its CEO. Gates funded the company's early development.
The company developed its platform in stealth mode before launching publicly in October 2018. Gates served as the “ultimate beta tester” during development, giving his input on the app's design, and remains an active user and advisor.
Release (October 2018)
Likewise officially released its platform in the US and Canada on October 3, 2018.
Growth (2020 COVID-19 Pandemic)
Likewise experienced accelerated growth alongside the COVID-19 pandemic. From March 2020 to July 2020, the platform's monthly active users tripled in numbers. The company reached one million users in July 2020.
Applications
Mobile
Likewise is available as a mobile app for the Android and iOS mobile operating systems. Users receive recommendations from the Likewise algorithm, people they follow, and the Likewise editorial team.
Likewise TV
In October 2019, the company launched its Apple TV app called Likewise TV. The television app organizes shows across streaming services under one watchlist. On July 20, 2020, Likewise TV expanded to Android TV and Amazon Fire TV users.
References
External links
Likewise website
2017 establishments in Washington (state)
Software companies based in Washington (state)
IOS software
Software companies established in 2017
Software development
Software companies of the United States
Web applications
Cloud applications | Likewise, Inc. | [
"Technology",
"Engineering"
] | 422 | [
"Software engineering",
"Computer occupations",
"Software development"
] |
65,228,866 | https://en.wikipedia.org/wiki/Hexafluorobutadiene | Hexafluorobutadiene is an organofluorine compound with the formula (CF2=CF)2. A colorless gas, it has attracted attention as an etchant in microelectronics. It is the perfluoroanalogue of butadiene.
It can be prepared by coupling of C2 compounds such as from chlorotrifluoroethylene or bromotrifluoroethylene. Routes from C4 species have also been demonstrated. For example, an early synthesis involved Zn-induced dechlorination of 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane.
Hexafluorobutadiene dimerizes via a [2+2] process at 150 °C to give perfluorinated divinylcyclobutanes.
See also
Hexafluoro-2-butyne, an isomer of C4F6
Hexafluorocyclobutene, an isomer of C4F6
Hexachlorobutadiene
References
Fluorocarbons
Monomers
Dienes | Hexafluorobutadiene | [
"Chemistry",
"Materials_science"
] | 256 | [
"Monomers",
"Polymer chemistry"
] |
75,161,417 | https://en.wikipedia.org/wiki/Finite%20subgroups%20of%20SU%282%29 | In applied mathematics, finite subgroups of are groups composed of rotations and related transformations, employed particularly in the field of physical chemistry. The symmetry group of a physical body generally contains a subgroup (typically finite) of the 3D rotation group. It may occur that the group with two elements acts also on the body; this is typically the case in magnetism for the exchange of north and south poles, or in quantum mechanics for the change of spin sign. In this case, the symmetry group of a body may be a central extension of the group of spatial symmetries by the group with two elements. Hans Bethe introduced the term "double group" (Doppelgruppe) for such a group, in which two different elements induce the spatial identity, and a rotation of may correspond to an element of the double group that is not the identity.
The classification of the finite double groups and their character tables is therefore physically meaningful and is thus the main part of the theory of double groups. Finite double groups include the binary polyhedral groups.
In physical chemistry, double groups are used in the treatment of the magnetochemistry of complexes of metal ions that have a single unpaired electron in the d-shell or f-shell. Instances when a double group is commonly used include 6-coordinate complexes of copper(II), titanium(III) and cerium(III). In these double groups rotation by 360° is treated as a symmetry operation separate from the identity operation; the double group is formed by combining these two symmetry operations with a point group such as a dihedral group or the full octahedral group.
Definition and theory
Let be a finite subgroup of SO(3), the three-dimensional rotation group. There is a natural homomorphism of SU(2) onto SO(3) which has kernel . This double cover can be realised using the adjoint action of SU(2) on the Lie algebra of traceless 2-by-2 skew-adjoint matrices or using the action by conjugation of unit quaternions. The double group is defined as . By construction, is a central subgroup of and the quotient is isomorphic to . Thus is a central extension of the group by , the cyclic group of order 2. Ordinary representations of are just mappings of into the general linear group that are homomorphisms up to a sign; equivalently, they are projective representations of with a factor system or Schur multiplier in . Two projective representations of are closed under the tensor product operation, with their corresponding factor systems in multiplying. The central extensions of by also have a natural product.
The finite subgroups of SU(2) and SO(3) were determined in 1876 by Felix Klein in an article in Mathematische Annalen, later incorporated in his celebrated 1884 "Lectures on the Icosahedron": for SU(2), the subgroups correspond to the cyclic groups, the binary dihedral groups, the binary tetrahedral group, the binary octahedral group, and the binary icosahedral group; and for SO(3), they correspond to the cyclic groups, the dihedral groups, the tetrahedral group, the octahedral group and the icosahedral group. The correspondence can be found in numerous text books, and goes back to the classification of platonic solids. From Klein's classifications of binary subgroups, it follows that, if a finite subgroup of SO(3), then, up to equivalence, there are exactly two central extensions of by : the one obtained by lifting the double cover ; and the trivial extension .
The character tables of the finite subgroups of SU(2) and SO(3) were determined and tabulated by F. G. Frobenius in 1898, with alternative derivations by I. Schur and H. E. Jordan in 1907 independently. Branching rules and tensor product formulas were also determined. For each binary subgroup, i.e. finite subgroup of SU(2), the irreducible representations of are labelled by extended Dynkin diagrams of type A, D and E; the rules for tensoring with the two-dimensional vector representation are given graphically by an undirected graph. By Schur's lemma, irreducible representations of are just irreducible representations of multiplied by either the trivial or the sign character of . Likewise, irreducible representations of that send to are just ordinary representations of ; while those which send to are genuinely double-valued or spinor representations.
Example. For the double icosahedral group, if is the golden ratio with inverse , the character table is given below: spinor characters are denoted by asterisks. The character table of the icosahedral group is also given.
{| class="wikitable"
|+ Character table: double icosahedral group
|-
! ||1||12C2[5]||12C3[5]||1C4[2]||12C5[10]||12C6[10] || 20C7[3] || 20C8[6] || 30C9[4]
|-
!
||1||1||1||1||1||1||1||1||1
|-
!
||3||||||3||||||0||0||−1
|-
!
||3||||||3||||||0||0||−1
|-
!
||4||−1||−1||4||−1||−1||1||1||0
|-
!
||5||0||0||5||0||0||−1||−1||0
|-
!
|| 2 || || || −2 || || || −1 || 1 || 0
|-
!
|| 2 || || || −2 || || || −1 || 1 || 0
|-
!
|| 4 || −1 || −1 || −4 || −1 || −1 || 1 || 0 || −1
|-
!
|| 6 || 1 || 1 || −6|| −1||−1|| 0|| 0 || 0
|}
{| class="wikitable"
|+ Character table: icosahedral group
! || 1 || 20C2[3] || 15C3[2] || 12C4[5] || 12C5[5]
|-
!
|| 1 || 1 || 1 || 1 || 1
|-
!
|| 3 || 0 || −1 || ||
|-
!
|| 3 || 0 || −1 || ||
|-
!
|| 4 || 1 || 0 || −1 || −1
|-
!
|| 5 || −1 || 1 || 0 || 0
|}
The tensor product rules for tensoring with the two-dimensional representation are encoded diagrammatically below:
The numbering has at the top and then below, from left to right, , , , , , , , and . Thus, on labelling the vertices by irreducible characters, the result of multiplying by a given irreducible character equals the sum of all irreducible characters labelled by an adjacent vertex.
The representation theory of SU(2) goes back to the nineteenth century and the theory of invariants of binary forms, with the figures of Alfred Clebsch and Paul Gordan prominent. The irreducible representations of SU(2) are indexed by non-negative half integers . If is the two-dimensional vector representation, then = S2j , the th symmetric power of , a -dimensional vector space. Letting be the compact group SU(2), the group acts irreducibly on each and satisfies the Clebsch-Gordan rules:
In particular for > 0, and By definition, the matrix representing in is just S2j ( ). Since every is conjugate to a diagonal matrix with diagonal entries and (the order being immaterial), in this case S2j ( ) has diagonal entries , , ... , , . Setting this yields the character formula
Substituting , it follows that, if has diagonal entries then
The representation theory of SU(2), including that of SO(3), can be developed in many different ways:
using the complexification Gc = SL(2,C) and the double coset decomposition Gc = B ⋅ w ⋅ B ∐ B, where B denotes upper triangular matrices and ;
using the infinitesimal action of the Lie algebras of SU(2) and SL(2,C) where they appear as raising and lowering operators , , of angular momentum in quantum mechanics: here E = , F = E* and H = [E, F] so that [H, E] = 2E and [H, F] = −2F;
using integration of class functions over SU(2), identifying the unit quaternions with 3-sphere and Haar measure as the volume form: this reduces to integration over the diagonal matrices, i.e. the circle group T.
The properties of matrix coefficients or representative functions of the compact group SU(2) (and SO(3)) are well documented as part of the theory of special functions: the Casimir operator commutes with the Lie algebras and groups. The operator can be identified with the Laplacian , so that on a matrix coefficient of , .
The representative functions form a non-commutative algebra under convolution with respect to Haar measure . The analogue for a finite subgroup of of SU(2) is the finite-dimensional group algebra C[] From the Clebsch-Gordan rules, the convolution algebra is isomorphic to a direct sum of matrices, with and . The matrix coefficients for each irreducible representation form a set of matrix units. This direct sum decomposition is the Peter-Weyl theorem. The corresponding result for C[] is Maschke's theorem. The algebra has eigensubspaces or , exhibiting them as direct sum of , summed over non-negative integers or positive half-integers – these are examples of induced representations. It allows the computations of branching rules from SU(2) to , so that can be decomposed as direct sums of irreducible representations of .
History
Georg Frobenius derived and listed in 1899 the character tables of the finite subgroups of SU(2), the double cover of the rotation group SO(3). In 1875, Felix Klein had already classified these finite "binary" subgroups into the cyclic groups, the binary dihedral groups, the binary tetrahedral group, the binary octahedral group and the binary icosahedral group. Alternative derivations of the character tables were given by Issai Schur and H. E. Jordan in 1907; further branching rules and tensor product formulas were also determined.
In a 1929 article on splitting of atoms in crystals, the physicist H. Bethe first coined the term "double group" (Doppelgruppe), a concept that allowed double-valued or spinor representations of finite subgroups of the rotation group to be regarded as ordinary linear representations of their double covers. In particular, Bethe applied his theory to relativistic quantum mechanics and crystallographic point groups, where a natural physical restriction to 32 point groups occurs. Subsequently, the non-crystallographic icosahedral case has also been investigated more extensively, resulting most recently in groundbreaking advances on carbon 60 and fullerenes in the 1980s and 90s. In 1982–1984, there was another breakthrough involving the icosahedral group, this time through materials scientist Dan Shechtman's remarkable work on quasicrystals, for which he was awarded a Nobel Prize in Chemistry in 2011.
Applications
Magnetochemistry
In magnetochemistry, the need for a double group arises in a very particular circumstance, namely, in the treatment of the magnetic properties of complexes of a metal ion in whose electronic structure there is a single unpaired electron (or its equivalent, a single vacancy) in a metal ion's d- or f- shell. This occurs, for example, with the elements copper, silver and gold in the +2 oxidation state, where there is a single vacancy in the d-electron shell, with titanium(III) which has a single electron in the 3d shell and with cerium(III) which has a single electron in the 4f shell.
In group theory, the character , for rotation, by an angle , of a wavefunction for half-integer angular momentum is given by
where angular momentum is the vector sum of spin and orbital momentum, . This formula applies with angular momentum in general.
In atoms with a single unpaired electron the character for a rotation through an angle of is equal to . The change of sign cannot be true for an identity operation in any point group. Therefore, a double group, in which rotation by is classified as being distinct from the identity operation, is used.
A character table for the double group D4′ is as follows. The new operation is labelled R in this example.
The character table for the point group D4 is shown for comparison.
{| class="wikitable"
|+ Character table: double group D4′
|-
!D'4 || || ||C4||C43||C2||2C2′||2C2″
|-
! ||E ||R ||C4R||C43R||C2R||2C2′R||2C2″R
|-
!A1′
||1||1||1||1||1||1||1|1
|-
!A2′
||1||1||1||1||1||1|−1||−1
|-
!B1′
||1||1||−1||−1||1||1||−1
|-
!B'2
||1||1||−1||−1||1||−1||1
|-
!E1′
||2||−2||0||0||−2||0||0
|-
!E2′
||2||−2||√2||−√2||0||0||0
|-
!E3′
||2 ||−2 ||−√2||√2 ||0 ||0 ||0
|}
{| class="wikitable"
|+ Character table: point group D4
|-
! D4 || E || 2 C4 || C2 || 2 C2′ || 2 C2
|-
! A1
|| 1 || 1 || 1 || 1 || 1 +
|-
! A2
|| 1 || 1 || 1 || −1 || −1
|-
! B1
|| 1 || −1 || 1 || 1 || −1
|-
! B2
|| 1 || −1 || 1 || −1 || 1
|-
! E
|| 2 || 0 || −2 || 0 || 0
|-
|}
In the table for the double group, the symmetry operations such as C4 and C4R belong to the same class but the header is shown, for convenience, in two rows, rather than C4, C4R in a single row.
Character tables for the double groups T′, O′, Td′, D3h′, C6v′, D6′, D2d′, C4v′, D4′, C3v′, D3′, C2v′, D2′ and R(3)′ are given in , and .
The need for a double group occurs, for example, in the treatment of magnetic properties of 6-coordinate complexes of copper(II). The electronic configuration of the central Cu2+ ion can be written as [Ar]3d9. It can be said that there is a single vacancy, or hole, in the copper 3d-electron shell, which can contain up to 10 electrons. The ion 2+ is a typical example of a compound with this characteristic.
Six-coordinate complexes of the Cu(II) ion, with the generic formula [CuL6]2+, are subject to the Jahn–Teller effect so that the symmetry is reduced from octahedral (point group Oh) to tetragonal (point group D4h). Since d orbitals are centrosymmetric the related atomic term symbols can be classified in the subgroup D4.
To a first approximation spin–orbit coupling can be ignored and the magnetic moment is then predicted to be , the so-called spin-only value. However, for a more accurate prediction spin–orbit coupling must be taken into consideration. This means that the relevant quantum number is , where .
When J is half-integer, the character for a rotation by an angle of radians is equal to minus the character for rotation by an angle . This cannot be true for an identity in a point group. Consequently, a group must be used in which rotations by are classed as symmetry operations distinct from rotations by an angle . This group is known as the double group, D4′.
With species such as the square-planar complex of the silver(II) ion [AgF4]2− the relevant double group is also D4′; deviations from the spin-only value are greater as the magnitude of spin–orbit coupling is greater for silver(II) than for copper(II).
A double group is also used for some compounds of titanium in the +3 oxidation state. Compounds of titanium(III) have a single electron in the 3d shell. The magnetic moments of octahedral complexes with the generic formula [TiL6]n+ have been found to lie in the range 1.63–1.81 B.M. at room temperature. The double group O′ is used to classify their electronic states.
The cerium(III) ion, Ce3+, has a single electron in the 4f shell. The magnetic properties of octahedral complexes of this ion are treated using the double group O′.
When a cerium(III) ion is encapsulated in a C60 cage, the formula of the endohedral fullerene is written as .
Free radicals
Double groups may be used in connection with free radicals. This has been illustrated for the species CH3F+ and CH3BF2+ which both contain a single unpaired electron.
See also
McKay graph
ADE classification
Molecular symmetry
Point group
Space group
Notes
References
Further reading
(web site)
Group theory
Molecular physics
Theoretical chemistry
Materials science | Finite subgroups of SU(2) | [
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75,161,466 | https://en.wikipedia.org/wiki/NGC%203353 | NGC 3353 is an Intermediate spiral galaxy located in the constellation of Ursa Major. Its velocity with respect to the cosmic microwave background is 1108 ± 12km/s, which corresponds to a Hubble distance of . In addition, four non-redshift measurements give a distance of . NGC 3353 was discovered on March 18, 1790, by William Herschel, a German born British astronomer.
NGC 3353 is a galaxy whose nucleus shines in the ultraviolet range. It is listed in the Markarian catalogue as Mrk 35.
NGC 3264 Group
NGC 3353 is part of the NGC 3264 group (also known as LGG 201), which includes at least five other members: NGC 3206, NGC 3220, NGC 3264, UGC 5848, and UGCA 211.
See also
List of NGC objects (3001–4000)
References
External links
3353
Ursa Major
Intermediate spiral galaxies
032103
17900318
Discoveries by William Herschel
035
+09-18-022
05860
10422+5613 | NGC 3353 | [
"Astronomy"
] | 219 | [
"Ursa Major",
"Constellations"
] |
75,161,560 | https://en.wikipedia.org/wiki/Herzberger%20Quader | The Herzberger Quader is a solid dissection puzzle invented by German mathematics teacher Gerhard Schulze.
It was named after his home-town Herzberg, and Quader is the latin-derived German word for a rectangular cuboid.
Design
The Herzberger Quader consists of a set of all possible polycubes from dicube to tetracubes.
The eleven pieces together have 40 unit cubes and thus can be stored in a 2 × 4 × 5 box.
Possible problems
Besides stowing the Herzberger Quader in its box there are a lot of figures that can be built using all parts. Various subsets can be used to form a 3 × 3 × 3 cube, one of them is the famous Soma cube.
Much more demanding tasks ask for the number of all different possibilities to arrange the initial parts in a certain figure. Or proofs are to be given for which figures can be realized or not realized with which polycubes.
History
Author of the Herzberger Quader is Oberstudienrat Gerhard Schulze (1919–1995), who was intensively engaged in mathematical games during his extracurricular activities in the years 1982–1994.
On the occasion of the 800th anniversary of his hometown Herzberg in 1984, the Herzberger Quader was produced for the first time and thus made known to a broad public.
Today, the Herzberger Quader is suggested to be used in the context of mathematics education.
References
Mechanical puzzles | Herzberger Quader | [
"Mathematics"
] | 308 | [
"Recreational mathematics",
"Mechanical puzzles"
] |
75,163,919 | https://en.wikipedia.org/wiki/SN%202004et | SN 2004et is a bright type IIP supernova that occurred in the spiral galaxy NGC 6946 (The Fireworks Galaxy), about 22 million light years away from Earth. The star that made the supernova was falsely identified to be a yellow supergiant but was then identified to be a type red supergiant of 13.8 solar masses. It was discovered alongside SN 2017eaw. SN 2004et showed some rebrightening about 1,000 days after the initial supernova probably due to ejecta of circumstellar material or thermal echo. SN 2004et was one of the most luminous type IIP supernovae ever recorded and characterized.
Discovery
SN 200et was discovered in 2004 and observed until 2009 by using the Spitzer InfarRed Array Camera, a ultra sensitive infrared space telescope that is used to study planets, stars, asteroids, comets, and galaxies.
References
Supernovae
Cygnus (constellation)
Astronomical objects discovered in 2004 | SN 2004et | [
"Chemistry",
"Astronomy"
] | 202 | [
"Supernovae",
"Cygnus (constellation)",
"Astronomical events",
"Constellations",
"Explosions"
] |
75,164,026 | https://en.wikipedia.org/wiki/Bandh%20Baretha | Bandh Baretha is a freshwater man-made wetland and wildlife sanctuary covering an area of 10 square kilometers. It is located approximately 50 kilometers south of Bharatpur city, in the Bayana tehsil of Bharatpur, India. This sanctuary serves as a significant winter resort for migratory birds and plays a crucial role in storing drinking water for the region.
The sanctuary is situated near the small river Kakund, which enters the south-western border of Bayana tehsil from the Karauli side. Here, the river's waters are held in the Baretha reservoir. During low rainfall years, the population of water birds increases, making it a large, permanent, and legally protected wetland.
Bundh Baretha is home to a diverse avian population, with a total of 67 water bird species, including six globally threatened species. It is an essential refuge for birds, especially when adverse conditions prevail in the nearby Keoladeo National Park wetlands. The aquatic vegetation in this sanctuary is similar to that found in Keoladeo National Park, further highlighting its ecological significance.
References
Bharatpur, Rajasthan
Wetlands of India
Constructed wetlands | Bandh Baretha | [
"Chemistry",
"Engineering",
"Biology"
] | 231 | [
"Bioremediation",
"Constructed wetlands",
"Environmental engineering"
] |
75,164,134 | https://en.wikipedia.org/wiki/Tropical%20Modernism | Tropical Modernism, or Tropical Modern is a style of architecture that merges modernist architecture principles with tropical vernacular traditions, emerging in the mid-20th century. This movement responded to the unique climatic and cultural conditions of tropical regions, primarily in Asia, Africa, Latin America, and the Pacific Islands. Pioneering architects like Geoffrey Bawa in Sri Lanka, and Charles Correa in India balanced modern architectural techniques with traditional building practices of their respective regions. Tropical Modernism's legacy continues to influence contemporary architectural practices, especially in the quest for sustainable design solutions in tropical climates.
Historical development
Tropical Modernism originated in the mid-20th century, a period marked by post-war modernization and decolonization, which saw emerging national identities across the Global South. The movement was a response to the modernist architectural approaches of the time, aiming to adapt them to the unique environmental and cultural contexts of tropical regions.
Origins and early pioneers
The early pioneers of Tropical Modernism include architects like Geoffrey Bawa in Sri Lanka, whose work demonstrated a profound understanding of the local climate and culture, blending modernist principles with traditional vernacular architecture. Similarly, architects like Charles Correa in India contributed to the movement by integrating modern architectural forms with traditional Indian architectural elements.
Post-war modernization
The post-war era saw a surge in modernization efforts across many tropical countries. The need for new infrastructure and urban development provided a fertile ground for the adaptation and evolution of modernist architectural principles in tropical contexts.
Decolonization and national identity
The period of decolonization in many tropical regions contributed to the rise of Tropical Modernism, as emerging nations sought to express their newly found national identities through architecture. The movement became a means to reflect a blend of modernity and tradition in architectural designs.
Regional variations and evolution
Tropical Modernism manifested differently across various regions, reflecting the unique cultural, political, and environmental conditions of each area. In West Africa, for instance, the movement was intertwined with political power and national identity. Similarly, in regions like Latin America and Southeast Asia, Tropical Modernism evolved to reflect the distinct vernacular traditions and modernization agendas.
Characteristics
Tropical Modernism is characterized by its seamless integration of modernist principles with tropical vernacular architectures. The style places a significant emphasis on environmental responsiveness, often characterized by extensive use of local materials, passive cooling strategies, and a strong indoor-outdoor connection.
Environmental responsiveness
A defining characteristic of Tropical Modernism is its responsiveness to the local climate. The design approach often incorporates passive cooling strategies, such as natural ventilation, shading, and water features, to mitigate the harsh tropical climate. Buildings designed in this style are typically oriented to maximize natural ventilation and minimize solar heat gain, thereby reducing the reliance on mechanical cooling systems.
Use of local materials
The use of local materials is a hallmark of Tropical Modernism, reflecting a commitment to sustainability and a respect for local traditions. Materials such as timber, stone, and thatch are commonly used, often in innovative ways that reflect both modernist and traditional craftsmanship.
Indoor-outdoor connection
One of the quintessential features of Tropical Modernism is the blurring of indoor and outdoor spaces to promote natural ventilation and a sense of openness. This is often achieved through the use of large openings, verandas, courtyards, and other transitional spaces, which encourage the flow of air and the extension of living spaces into the landscape.
Architectural elements
Tropical Modernism often incorporates architectural elements that are characteristic of the local vernacular, such as pitched roofs, wide eaves, and raised floor levels, which are adapted to modernist sensibilities. The juxtaposition of modern and traditional elements creates a distinctive architectural language that reflects a synthesis of global modernist trends with local building traditions.
Notable practitioners
Tropical Modernism has been significantly shaped by a number of architects who melded modern architectural principles with tropical vernacular designs. Some notable practitioners include:
Maxwell Fry and Jane Drew. This couple of British architects were active in British West Africa (Ghana, Nigeria, Gambia and Sierra Leone), where they used new construction methods and innovative techniques of climate control (e.g., adjustable louvers, wide eaves and brises soleils). They drew international attention to the principles of modernism as applied to the tropical context through the establishment of the Department of Tropical Architecture at the Architectural Association in 1954 and through their influntial book Tropical Architecture in the Humid Zone (1956).
Geoffrey Bawa: A Sri Lankan architect known for pioneering Tropical Modernism. His work exemplifies the integration of modernist design principles with the traditional architectural elements of Sri Lanka, creating a unique, locally adapted style of modern architecture.
Vladimir Ossipoff: Known as the “master of Hawaiian architecture,” Ossipoff’s work prominently features the elements of Tropical Modernism. His designs emphasize natural ventilation, indoor-outdoor integration, and the use of local materials to create buildings suited for Hawaii’s climate.
Charles Correa: An Indian architect who significantly contributed to Tropical Modernism by integrating modern architectural forms with traditional Indian architectural elements. His design for the Gandhi Smarak Sangrahalaya in Ahmedabad is a notable example.
Lúcio Costa and Oscar Niemeyer: These Brazilian architects were instrumental in the development of Tropical Modernism in Brazil, with their design for the city of Brasília showcasing modernist architectural principles adapted to the tropical climate.
Exemplary projects
Tropical Modernism is epitomized in various projects that showcase the movement's key characteristics of environmental responsiveness, use of local materials, and indoor-outdoor connectivity. Here are some exemplary projects:
Kandalama Hotel, Sri Lanka: Designed by Geoffrey Bawa, this hotel is a quintessential example of Tropical Modernism. Its design incorporates the natural landscape, local materials, and modern architectural principles.
Liljestrand House, Hawaii: Designed by Vladimir Ossipoff, this house exemplifies the seamless integration of indoor and outdoor spaces, a hallmark of Tropical Modernism.
Gandhi Smarak Sangrahalaya, Ahmedabad, India: This museum, designed by Charles Correa, reflects the principles of Tropical Modernism with its use of local materials, passive cooling techniques, and integration of indoor and outdoor spaces.
Palácio do Planalto, Brasília, Brazil: Designed by Lúcio Costa and Oscar Niemeyer, this presidential palace showcases Tropical Modernism with its modernist design adapted to the tropical climate.
The Salk Institute, La Jolla, California: Although not located in a tropical region, the design by Louis Kahn incorporates key principles of Tropical Modernism.
Pearl Bank Apartments, Singapore: Designed by Tan Cheng Siong, this residential high-rise is a hallmark of Tropical Modernism in Southeast Asia.
Faculty of Architecture Building, Khon Kaen University, Thailand: This building is an example of how Tropical Modernism can be integrated into educational infrastructure.
Regional variations
Tropical Modernism, though rooted in modernist architectural principles, has been diversified and enlivened by its interaction with various regional vernacular traditions. Below are some regional variations:
Hawaii: In Hawaii, the style became prominent through the works of architects like Vladimir Ossipoff, who blended Modernism with local vernacular styles. His designs highlighted the importance of environmental responsiveness and cultural sensitivity, which are now considered as seminal examples of Tropical Modernism in the Pacific region.
West Africa: The style was also adapted in West Africa where it was used as a tool to assert a modern identity post-independence. Architects such as Maxwell Fry and Jane Drew utilized Tropical Modern principles to design buildings suited to the local climate while embodying a modern aesthetic.
Brazil: In Brazil, architects like Paulo Mendes da Rocha gained international recognition for sustainable designs embodying Tropical Modernism. This regional variant emphasized functionality, aesthetic appeal, and incorporation of natural elements, reflecting a synthesis of Modernism and "Brasilidade" or Brazilian-ness.
Criticism and colonial legacy
Tropical Modernism has faced criticism for its colonial roots, particularly in regions such as West Africa. Initially, this architectural style was employed by colonial powers, representing a form of colonial imposition, especially in British West Africa. The design principles of Tropical Modernism were largely tailored to cater to the comfort of colonial administrators, fostering a notion of a more productive colonial subject to counter calls for independence. Despite its Eurocentric beginnings, post-independence leaders like Kwame Nkrumah recognized the potential of Tropical Modernism for nation-building, intertwining it with Pan-African ideologies to foster a sense of national identity and progress.
Perspectives surrounding Vladimir Ossipoff and Tropical Modernism in Hawaii are nuanced. Ossipoff, often dubbed as the "master of Hawaiian architecture," played a pivotal role in bringing the essence of Tropical Modernism to the Hawaiian Islands. His work is known for its environmental sensitivity, cultural contextualization, and appropriateness to Hawaii's unique landscape characteristics, portraying a harmonious blend between modern architectural principles and local cultural and geographic contexts. He was known for his conviction-driven, no-nonsense approach towards architecture, waging what he called a "war on ugliness," which was brought on by dismal architectural design and rampant over-development in the Hawaiian Islands.
However, it's essential to note that the term "Tropical Modernism" itself, as a broader movement beyond Ossipoff's work, has faced criticisms for potentially carrying colonial or Eurocentric undertones, especially when applied in non-Western contexts like Africa. Critics argue that the movement, while aiming to blend modernist and local vernacular architectures, might inadvertently perpetuate a form of architectural colonialism or exhibit a Eurocentric bias, often by dismissing or undervaluing local architectural traditions in favor of modernist principles.
Contemporary relevance
The contemporary relevance of Tropical Modernism lies in its ability to address climate-related challenges inherent to tropical regions. Several aspects underscore its modern-day significance:
Sustainable development: Approximately 50% of the world's population resides in the tropical belt, where the fastest-growing cities are located, along with 70% of the forests that help contain CO2 emissions. The principles of Tropical Modernism are crucial for designing coherent and adapted architecture in these regions, recognizing the values of tropicality along with its specificities.
Environmental responsiveness: The style emphasizes passive design elements to achieve thermal comfort, an approach that is critical in tropical climates characterized by high temperatures and humidity. Features such as sunshades, overhangs, and the use of local materials contribute to energy efficiency and environmental sustainability.
Regional architectural expressions: The resurgence of regional architectures, including Tropical Modernism, is noted in international architectural discourse. This style allows for the exploration of regionalized aesthetics, encouraging reflective design practices that contemplate environmental and human contingencies. It challenges the globalized mainstream architectural aesthetics, promoting a more contextual and thoughtful architectural practice.
See also
Modern architecture
Vernacular architecture
Sustainable architecture
New Khmer Architecture
References
1950s architecture
20th-century architectural styles
Modernist architecture
Sustainable architecture
Low-energy building
Sustainable development
Postcolonialism | Tropical Modernism | [
"Engineering",
"Environmental_science"
] | 2,196 | [
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75,164,769 | https://en.wikipedia.org/wiki/Diabetes%20self-management | Diabetes self-management refers to the ongoing process in which individuals with diabetes actively participate in managing their condition through lifestyle choices, medication adherence, blood glucose monitoring, and education, aimed at maintaining optimal blood sugar levels and preventing complications.
Diabetes is a chronic disease affecting over 537 million adults worldwide in 2021 and predicted to reach 643 million people by 2030. It is a global health burden and improving the health outcomes for people with diabetes is critical to reducing the economic and human burden of diabetes. Self-management is the cornerstone for successful health outcomes in diabetes patients as there is a positive association between self-management behaviour and care outcomes. Self-management stresses the importance of the role of an individual and their responsibility in developing skilled behaviours to manage one's own illness.
Self-management activities
Healthcare organisations are increasingly focusing on providing diabetes self-management education and support programs to enable diabetes patients to effective self-management. Diabetes patients face daily challenges due to the impact of their decisions on their health outcomes. Diabetes self-management helps diabetes patients to make better decisions and change their behaviour to achieve better outcomes. Diabetes self-management activities mainly consist of seven self-care behaviours. They are healthy eating, monitoring indicators of diabetes, physical activity, taking medication, healthy coping, and problem-solving.
Foot care
Diabetes patients with peripheral neuropathy and peripheral artery disease are at risk of developing foot ulcers and infection. Poor knowledge about self-care increases the risk of amputation. Adoption of suitable preventative measures and early treatment of diabetic foot problems are important components of diabetes foot care. Good knowledge and practice regarding diabetes foot care can reduce the risk of foot complications and amputation. Regular examination of the foot is one of the fundamental steps to modifying the foot risk factors thereby reducing the risk of ulceration and amputation. Footwear tailored to the specific pathology of the patient can enable conservative management of the foot including debridement of the callus. Appropriate footwear can reduce abnormal pressure, reduce the rate of formation callus and ulcers and protect the foot from external trauma.
Blood glucose monitoring
Regular monitoring of blood glucose and optimal glucose control is a major part of diabetes self-management. Diabetes patients need to be capable of testing blood sugar at home at the recommended frequency. Frequent self- monitoring of blood glucose and record keeping is key to identifying the possibility of hypoglycemia. Diabetes patients should be able to know how to respond when blood sugar levels are too high or too low.
Medication
Effective medication is the cornerstone of the proper treatment of diseases. Many patients fail to take the medication as prescribed and many patients prematurely discontinue their medication. Poor medication adherence in patients with diabetes is a costly public health challenge in many healthcare systems. Non-adherence to medication leads to poor treatment outcomes and the progression of diseases and complications. The medication adherence of type 1 and type 2 diabetes patients assessed using self-report, pill counts, electronic monitoring devices and medication possession ratio found that the medication adherence rates ranged from 31% to 87%. The medication adherence of diabetes patients is also measured by persistence which is defined by the proportion of patients who remained in treatment for a predetermined period and the mean number of days till discontinuation of treatment. The persistence rates ranged from 16% to 63% at 12 months and ranged from 29% to 70%.
Physical activity
Physical activity has a favourable influence on the health and well-being of diabetes patients as it achieves physiological changes, including improved overall glycemic control, liver insulin sensitivity, muscle glucose uptake and utilisation and overcomes the metabolic abnormalities related to type 2 diabetes. Diabetes patients can undertake light to moderate physical activity. The type of physical activity that can be performed by diabetes patients needs to be determined after consultations with health care providers. The physical activities recommended for diabetes patients include brisk walking, recreational games and leisure time activities. The most benefit of physical activity happens in the early progression of the disease.
Healthy eating habits
A healthy diet is one component of the management of diabetes. Dietary self-care behaviours include eating a low-saturated-fat diet making choices based on the glycemic index of food and controlling the amount of carbohydrates in food. Sticking to the eating plan and following the diet plan when eating from a restaurant or when feeling stressed is a major challenge for diabetes patients.
Recommended practices and specific behaviors
Understanding the levels (recommended practices) and patterns (specific behaviors) of primary daily diabetes self-management from a heterogeneous sample population is essential to devise suitable interventions to enhance the daily diabetes management of diabetes patients. Many of the diabetes self-management data involve only a small and highly selected sample, which does not represent the minorities and disadvantaged communities. The study conducted on a heterogeneous sample of population including minorities found that self-management levels increase with age. The same study found that retired individuals and homemakers have better self-management than employed individuals.
Barriers to effective self-management
Diabetes patients need to actively self-manage their diseases in everyday life for good diabetes outcomes. However, there are certain barriers to the effective day-to-day management of the disease. This section identified the main barriers to the effective self-management of diabetes.
Financial constraints
Financial constraints or poverty is a barrier to effective self-management as it prevents access to food, healthcare, medication and information. The most significant impact of lack of financial resources is on the food consumption pattern, resulting in a vicious cycle of high carbohydrate consumption and hyperglycaemia. Diabetes patients with limited financial resources often report that they find it difficult to purchase adequate food and it becomes impossible to buy different food for the family. Financial difficulties cause diabetes care to become a problem of least importance as they have more pressing needs such as feeding the family and repaying loans. When it comes to buying medicines for diabetes management, people from poor financial backgrounds choose food over medicine. To save costs, people from poor economic backgrounds alter the prescribed dosage of medication and medication is often taken with diabetes complications or the development of co-morbid illness.
Norms and belief system
The attitude towards self-care behaviour is influenced by the local belief systems and social norms. Patients who attribute diabetes control to god are less likely to self-manage and control their sugar intake. A study found that subjective norms attributed to 49% of the variance in the intent to perform diabetes-related self-management.
An individual's and their family's beliefs about diabetes influence how they make sense of their disease and make efforts to manage their illness. For example, individuals who are not adhering to the dietary intake shared the view that their decision to not follow the required dietary pattern is because they believe that their family, friends and peers would not approve of their diet. Inadequate family support and cultural beliefs prevent diabetes patients from adhering to a diet with low-saturated fatty acids. In Subsaharan Africa, diabetes patients face social stigma from family and community members from diabetes and diabetes-related self-management requirements which prevent diabetes-related self-care. A study found that when there is diabetes that runs in the family, it becomes a family affair and participants normalise and downplay the seriousness of the disease.
Gender-based family roles prevent adhering to the medication. In a study, woman responsible for house duties were found to have inadequate time to visit health facilities resulting in their ignoring their health care needs such as diabetes management.
Low knowledge
Diabetes knowledge has a significant influence on the self-care and glycemic control of a diabetes patient. The lower knowledge about diabetes can affect diabetes management. Studies have found that patient's lack of knowledge and poor self-care practice is increasing the severity of diabetes every year. The level of education is a factor that has a positive correlation with self-care knowledge.
Stigma
Family support is highly beneficial for effective self-care. Diabetes-related stigma leads to a lack of family support and poor diabetes-related self-management behaviours.
Inadequate support
Diabetes patients expressed dissatisfaction with the attitude of healthcare professionals as they directly wrote prescription and directions without a proper conversation with the patients. This prevents patients from asking lingering questions about their health conditions and management.
Inadequate coordination between the health care providers and diabetes patients is a major barrier to properly implementing the care guidelines. Lack of collaboration and coordination leads to information conflict affecting the quality of self-management. The diabetes patients who were identified to develop healthy diabetes management habits had a supportive patient-provider relationship. People from economically disadvantaged backgrounds can have limited access to care which is one reason for inadequate coordination between healthcare providers and patients.
Role of healthcare professionals
Healthcare professionals play a crucial role in diabetes self-management. Diabetes patients rely on health care professionals to obtain information and support in developing an individualised self-management plan. Self-management goals and recommendations given by health care professionals were identified to have a significant positive impact on the eating habits and physical activity of diabetes patients. Lack of proper emphasis on self-management may suggest to diabetes patients that self-management is either less important or even unimportant for diabetes management.
References
Diabetes
Medicine | Diabetes self-management | [
"Biology"
] | 1,851 | [
"Medicine"
] |
75,165,357 | https://en.wikipedia.org/wiki/Groq | Groq, Inc. is an American artificial intelligence (AI) company that builds an AI accelerator application-specific integrated circuit (ASIC) that they call the Language Processing Unit (LPU) and related hardware to accelerate the inference performance of AI workloads.
Examples of the types AI workloads that run on Groq's LPU are: large language models (LLMs), image classification, anomaly detection, and predictive analysis.
Groq is headquartered in Mountain View, CA, and has offices in San Jose, CA, Liberty Lake, WA, Toronto, Canada, London, U.K. and remote employees throughout North America and Europe.
History
Groq was founded in 2016 by a group of former Google engineers, led by Jonathan Ross, one of the designers of the Tensor Processing Unit (TPU), an AI accelerator ASIC, and Douglas Wightman, an entrepreneur and former engineer at Google X (known as X Development), who served as the company’s first CEO.
Groq received seed funding from Social Capital's Chamath Palihapitiya, with a $10 million investment in 2017 and soon after secured additional funding.
In April 2021, Groq raised $300 million in a series C round led by Tiger Global Management and D1 Capital Partners. Current investors include: The Spruce House Partnership, Addition, GCM Grosvenor, Xⁿ, Firebolt Ventures, General Global Capital, and Tru Arrow Partners, as well as follow-on investments from TDK Ventures, XTX Ventures, Boardman Bay Capital Management, and Infinitum Partners. After Groq’s series C funding round, it was valued at over $1billion, making the startup a unicorn.
On March 1, 2022, Groq acquired Maxeler Technologies, a company known for its dataflow systems technologies.
On August 16, 2023, Groq selected Samsung Electronics foundry in Taylor, Texas to manufacture its next generation chips, on Samsung's 4-nanometer (nm) process node. This was the first order at this new Samsung chip factory.
On February 19, 2024, Groq soft launched a developer platform, GroqCloud, to attract developers into using the Groq API and rent access to their chips. On March 1, 2024 Groq acquired Definitive Intelligence, a startup known for offering a range of business-oriented AI solutions, to help with its cloud platform.
Groq raised $640 million in a series D round led by BlackRock Private Equity Partners in August 2024, valuing the company at $2.8 billion.
Language Processing Unit
Groq's initial name for their ASIC was the Tensor Streaming Processor (TSP), but later rebranded the TSP as the Language Processing Unit (LPU).
The LPU features a functionally sliced microarchitecture, where memory units are interleaved with vector and matrix computation units. This design facilitates the exploitation of dataflow locality in AI compute graphs, improving execution performance and efficiency. The LPU was designed off of two key observations:
AI workloads exhibit substantial data parallelism, which can be mapped onto purpose built hardware, leading to performance gains.
A deterministic processor design, coupled with a producer-consumer programming model, allows for precise control and reasoning over hardware components, allowing for optimized performance and energy efficiency.
In addition to its functionally sliced microarchitecture, the LPU can also be characterized by its single core, deterministic architecture. The LPU is able to achieve deterministic execution by avoiding the use of traditional reactive hardware components (branch predictors, arbiters, reordering buffers, caches) and by having all execution explicitly controlled by the compiler thereby guaranteeing determinism in execution of an LPU program.
The first generation of the LPU (LPU v1) yields a computational density of more than 1TeraOp/s per square mm of silicon for its 25×29 mm 14nm chip operating at a nominal clock frequency of 900 MHz. The second generation of the LPU (LPU v2) will be manufactured on Samsung's 4nm process node.
Performance
Groq emerged as the first API provider to break the 100 tokens per second generation rate while running Meta’s Llama2-70B parameter model.
Groq currently hosts a variety of open-source large language models running on its LPUs for public access. Access to these demos are available through Groq's website. The LPU's performance while running these open source LLMs has been independently benchmarked by ArtificialAnalysis.ai, in comparison with other LLM providers. The LPU's measured performance is shown in the table below:
See also
Central processing unit
Graphics processing unit
References
External links
Computer companies of the United States
Companies based in California
Companies based in Sunnyvale, California
Companies based in Silicon Valley
Computer hardware companies
Semiconductor companies of the United States
Fabless semiconductor companies
Electronics companies established in 2016
2016 establishments in California | Groq | [
"Technology"
] | 1,047 | [
"Computer hardware companies",
"Computers"
] |
75,165,446 | https://en.wikipedia.org/wiki/Gaia%20Pigino | Gaia Pigino is the Associate Head of the Structural Biology Research Center and Leader of the "Pigino Group" at the Human Technopole in Milan, Italy.
Education
Gaia Pigino studied Natural Science at the University of Siena in Italy, finishing with a Diploma in 2002. From 2003 to 2007, she earned her Ph.D., working in the Department of Evolutionary Biology at the University of Siena, supervised by Prof Fabio Bernini and Prof Claudio Leonzio.
Career and research
From 2007 to 2009, Gaia Pigino was employed at the Laboratory of Cryotechniques for Electron Microscopy in the Department of Evolutionary Biology of the University of Siena, under the guidance of Prof. Pietro Lupetti. she continued her postgraduate studies, also attending the prestigious Physiology course at the Marine Biological Laboratory (MBL) in Woods Hole (Massachusetts, USA). Subsequently, Gaia Pigino worked with Prof. Takashi Ishikawa at the ETH Zurich from 2009 to 2011 and then at the Paul Scherrer Institute from 2011 to 2012.
From 2012 to 2021, Gaia Pigino was a Research Group Leader at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany.
Since 2021, Gaia Pigino has been the Associate Head of the Structural Biology Research Center and Leader of the "Pigino Group" at the Human Technopole in Milan, Italy.
Her research group operates at the intersection of structural and molecular cell biology, utilizing the most current methodologies from both areas to investigate the structure and dynamics of molecular machines that participate in the assembly and function of motile and primary cilia. Their overarching objective is to comprehend the fundamental molecular mechanisms of ciliary functions, as well as their malfunctions in ciliopathies.
Gaia Pigino is an internationally well-known biologist. Hence, she is frequently invited to workshops, seminars and conferences in the field.
Awards and honours
2017 Journal of Cell Science - Cell scientist to watch
2018 in annual meeting ASCB | EMBO she was awarded “The Keith R. Porter Fellow Award for Cell Biology 2018”
2019 - German Research Foundation (DFG) grant
2019–2024 - European Research Council (ERC) Consolidator Grant "CiliaTubulinCode"
2022 - Appointed "EMBO Member"
References
Living people
Microscopists
European Research Council grantees
University of Siena alumni
Year of birth missing (living people) | Gaia Pigino | [
"Chemistry"
] | 493 | [
"Microscopists",
"Microscopy"
] |
75,166,884 | https://en.wikipedia.org/wiki/Margot%20Dorenfeldt | Margot Dorenfeldt (1895–1986) was the first woman to graduate from Norwegian Institute of Technology (1919) and specialized in inorganic chemistry and electrochemistry. She published several papers in radiochemistry.
Biography
She was the daughter of Lauritz J. Dorenfeldt (1863–1932), an engineer who was educated in Berlin, and the granddaughter of businessman Lauritz Dorenfeldt Jenssen (1837–1899). Her mother was Aagot Bødtker (1869–1963). Margot was born 2 October 1895 in Worms, Germany, when her family was there; her father was working on assignment as technical director of a cellulose factory.
Margot Dorenfeldt was the second woman to enroll at the Norwegian Institute of Technology (NTH) after Aslaug Urbye (who enrolled in 1910, but never completed her studies). In 1919, Dorenfeldt became the first woman to graduate from NTH. While in college, she was active in student debates and made critical comments about her fellow engineers and their record of participation in social politics.
Career
Dorenfeldt found her first job in 1920 as an assistant at the chemistry laboratory at Royal Frederick University (now University of Oslo). A few months later, she was promoted to a secretary-like position, from which she could perform research and teach. Soon she was investigating the atomic weight of chlorine while working with the radiochemist and associate professor Ellen Gleditsch, who had previously worked with Marie Curie in Paris. Dorenfeldt helped publish their results in English, German and French.
In 1922, the university granted Dorenfeldt a scholarship so she could study at the Collège de France in Paris. While there she met and married a fellow Norwegian and changed her name to Margot Dorenfeldt Holtan. She published research using her married name as well as her maiden name.
As a wife and mother of two, Margot attended to her family but continued working in the field as a part-time secretary and chemist and, according to her own records, she also published scientific work with her husband. Throughout her life, she remained close to her father and his business interests and she took a government position in 1946 and then became an association board member from which she could help protect the interests of his pulp and paper businesses.
Personal life
She was married on 23 February 1923 in Paris to Norwegian engineer Eugen Nannestad Holtan (1893–1959).
References
1895 births
1986 deaths
Norwegian chemists
Nuclear chemists
Norwegian women chemists
20th-century Norwegian women scientists
Women chemists | Margot Dorenfeldt | [
"Chemistry"
] | 531 | [
"Nuclear chemists"
] |
75,166,991 | https://en.wikipedia.org/wiki/Wrexham%20Police%20Station%20%281973%E2%80%932020%29 | The Wrexham Police Station () was a police station housed in a tall brutalist building, located on Bodhyfryd in Wrexham, Wales. Constructed in 1973 and demolished in 2020, the tower was the tallest building in Wrexham, overtaking St Giles' Church. The building served as a North Wales Police divisional headquarters and Wrexham's police station.
Concerns over maintenance costs and the overall state of the building were raised in 2011. North Wales Police vacated the building in 2019. It was rejected for listed status by Cadw and in November 2020 was demolished in a controlled explosion, amid a national lockdown. Police officers relocated to Llay HQ and to a smaller station near the Wrexham Library. A Lidl supermarket has been built on the site.
Description
The station was built in the Brutalist architecture style between 1973 and 1975. It was designed by Eric Langford Lewis, the county architect, and Stuart Brown, the assistant county architect. The building was ten-storeys, and built with an re-enforced concrete frame clad containing pre-cast corrugated concrete panels. The building's defining aspect was its cantilevered tower which emerged from the building's central stalk. The tower was tall, and contained the main offices, briefing and interview rooms, and the Special Branch's highly specialised accommodation. When opened, the tower became Wrexham's tallest building, overtaking the tower of St Giles' Church. The building served as the divisional headquarters of North Wales Police until replaced by a facility in Llay, as well as Wrexham's police station, since replaced by a smaller one near Wrexham library.
Its Brutalist architecture style made it difficult for some to like, described once as a "monstrosity". Cadw, the Welsh Government's historic environment service in a letter explaining its refusal to list the building, said it was a "rare and unusual (possibly unique) example of slab and podium design in Wales which makes an expressive architectural statement", but that "in the handling of form, materials and design, the building does not compare favourably with other buildings of similar design which are notably more sophisticated and elegant". North Wales Police and Crime Commissioner, Arfon Jones acknowledged that the tower defined the skyline of Wrexham for an era but said he could not get "very sentimental about the old HQ" and "always thought it was a bit of a dump".
History
Construction of the building began in 1973, and it opened in 1975. The building served as an integral part of the Bodhyfryd site alongside the Wrexham Memorial Hall, Wrexham Law Courts and Waterworld. The police station replaced the old Wrexham city centre police station, which was housed in County Buildings, now the Wrexham County Borough Museum.
In 2011, North Wales Police expressed concerns that the building could no longer be used, as it was very expensive to maintain. The cost of maintaining the building over the next ten years was estimated to be £6 million, and the police force had suggested that "it is likely the tower will be removed", hinting at a possible demolition of some form. At the same time, the police station in Mold, Flintshire was also under review and was recommended to remain open while the Wrexham station's future remained uncertain. The force later announced it would build a new facility in Llay, on the outskirts of Wrexham. No decision was made at the time on what the existing building should become, but only that it was "no longer suitable" and "no longer fit for purpose" for the police force to use, due to the building's poor aging facilities and high maintenance costs. In 2012, the police force cut opening times at its police stations, including in Wrexham, to save money.
A pair of peregrine falcons nested on the tower roof for a number of years and a webcam monitored several chicks being hatched and fledged. The falcons had been relocated by August 2015 when the building was proposed for demolition.
Proposals for demolition
It was originally set to be demolished in August 2016. Its proposed demolition raised concerns that the adjacent buildings, which form Wrexham's "civic area", namely a magistrates' court, Wrexham Waterworld, Wrexham Memorial Hall, the local cenotaph and the Crown Buildings would also be under review. However, the recent abandonment by the council to demolish Waterworld, had been argued to have quelled fears of a "mass land sell off", although concerns remained over the possibility of moving the courts to Mold, and a councillor's disapproval of the police station site being turned into homes. In November 2016, the building was put up for sale, with the expectation it would be vacated by 2018.
The police station closed in January 2019, and police services temporarily relocated to Crown Buildings on Chester Street. A smaller police station opened in May 2019 conjoined with the Wrexham Library building, and a larger police headquarters facility opened in Llay in November 2018.
In February 2019, Cadw, the Welsh Government's historic environment service responsible for listed buildings in Wales, reviewed a request for the listing of the building to protect it from demolition. Police and Crime Commissioner, Arfon Jones, stated that if the building was not demolished, the proposed sale of the site to supermarket chain Lidl would fall through, negatively impacting police funding in North Wales. Jones had written a joint-statement, with the North Wales Police chief constable Carl Foulkes, to Jason Thomas, the Welsh Government's director for Culture, Tourism and Sport asking for clarity on the possible listing. Cadw confirmed the building would not be listed and so the demolition could proceed. Local people were split on the issue, some calling it an "iconic building" of Wrexham, while others stated it was an "eyesore".
Demolition
The planned demolition of the building was approved in March 2020. Removal of the tower's electrical equipment started in July 2020. Parts of the building were demolished through to October 2020, while the rest, including the tower, was demolished on 1 November 2020 in a controlled explosion streamed online during Wales' national lockdown. Some local roads were closed during the demolition. The demolition was featured in the TV show Scrap Kings.
Site
The entire site was expected to sell for £1.5 million, and be available for homes, retail outlets and a hotel. In January 2017, the council announced it was assessing bids for the site. In August 2018, Lidl submitted an application to open a store on the site. The council conducted a retail assessment into the need for a new supermarket and later stated that Lidl had successfully demonstrated the need for a new store. Concerns raised by neighbouring supermarket Asda over an excessive increase in traffic in the area were dismissed by planners, who stated the estimated five per cent increase was not significant and nor would a planned drive-through coffee shop increase traffic or have an impact on pollution. The council planning committee later unanimously approved the scheme.
Nine months prior to the demolition, a petition was submitted opposing the redevelopment of the site for a supermarket. The petition did not suggest alternatives, but criticised the redevelopment and stated that the data used to gauge demand for a new supermarket was outdated. Some of those signing the petition proposed a walk-in hospital or an indoor ski centre, while others said there were already too many supermarkets in the town. By October 2020, shortly before the full demolition, 365 people had signed the petition. Nonetheless, a Lidl supermarket was built on the site. The proposal for a drive-through coffee shop was not followed through.
References
Buildings and structures in Wrexham
1973 establishments in Wales
2020 disestablishments in Wales
Police stations in Wales
Demolished buildings and structures in Wales
Buildings and structures completed in 1973
Buildings and structures demolished in 2020
Buildings and structures demolished by controlled implosion | Wrexham Police Station (1973–2020) | [
"Engineering"
] | 1,570 | [
"Buildings and structures demolished by controlled implosion",
"Architecture"
] |
75,167,447 | https://en.wikipedia.org/wiki/Urban%20forest%20inequity | Urban forest inequity, also known as shade inequity or tree canopy inequity, is the inequitable distribution of trees, with their associated benefits, across metropolitan areas. This phenomenon has a number of follow-on effects, including but not limited to measurable impacts on faunal biodiversity and the urban heat island effect. Urban heat inequity occurs when intra-urban heat islands, with their associated negative physical and emotional health consequences, are more common and more intense in lower-income communities.
Potential solutions to urban forest inequity include but are not limited to investment in marginalized communities, tree-planting initiatives, and more. Examples of urban forest inequity can be seen in various cities across the world.
Definitions
Urban forests
Urban forests are areas of land covered by trees or other vegetation located in and around places of intensive human influence, particularly metropolitan, urban areas such as cities. Urban forests, though present on both public and private land, typically are found on public spaces due to the predominance of street trees noted by researcher Steven Strom. Urban forests are recognized for their significant role in mitigating the impacts of climate change, exemplified by their role in mitigating heat and flood risks and their contribution to green infrastructure is seen as a nature-based solution for climate change adaptation and mitigation. Trees and vegetation absorb and store rainwater during heavy rainfall events, reducing flood risk, and capture carbon dioxide from the atmosphere as part of climate change mitigation efforts. Additionally, urban forests are also important in maintaining the biodiversity of an urban area, particularly the avifauna (birds) of the area. These characteristics of urban forests help contribute to the creation of healthy, resilient, and sustainable cities in a cost-effective manner.
Urban forest inequity
Urban forest inequity is a phenomenon in which the distribution of and access to trees and nature is inequitable in urban areas. It is thought to be an example of environmental injustice, as it disproportionately impacts marginalized communities. Numerous studies, including a 2017 meta-analysis done by researchers Ed Gerrish and Shannon Lea Watkins, have found a positive relationship between income and urban forest coverage. This introduces the concept of the luxury effects, which explains how the disparities in urban forest cover coincide with socio-economic and historical factors. The luxury effect illustrates how wealthier areas tend to exhibit higher biodiversity, reflecting the influence of socioeconomic factors and education levels in shaping the quantity and quality of green spaces in a given area. Moreover, inequitable distribution of greenery in urban areas may restrict an equal distribution of the benefits of urban forests, which include reducing stress and anxiety, cultivating a safe community, emotional fulfillment, mitigating the effects of global warming, and more. For instance, canopy cover quantity in an area can diminish the urban heat island effect and increase carbon sequestration from the atmosphere. Various historical, cultural, and institutional factors contribute to the perceived inequities in urban forestry management and inequitable distribution of urban greenery. A 2022 paper published in the International Journal of Environmental Research and Public Health found that vulnerable residents of an urban area, particularly lower-income residents and those who live further from urban forests and green space, are particularly susceptible to the urban heat island effect. There are examples of urban forest inequity in cities globally, some of which are listed below.
Associated problems
Environmental justice and spatial justice are two ideologies associated with the problems presented by urban forest inequity, and these ideologies seek to understand the disproportionate quality of life due to uneven environmental or spatial conditions and benefits. Problems commonly associated with urban forest inequity include but are not limited to the urban heat island effect, public health concerns, and the inequitable distribution of environmental benefits. In a 2022 paper, socio-spatial inequalities specialist Bernard Bret and geographer Sophie Moreau described environmental justice and spatial justice as two concepts defined by an interconnectedness between geographical space and quality of life. The U.S. Environmental Protection Agency has found that inequities are most often visible along the lines of “income, race, color, or national origin.” For example, South Africa historically has treated minority populations unequally, particularly by means of racial segregation, perhaps most clearly evident in the South African apartheid that occurred for the greater part of the twentieth century. Researchers in South Africa in a 2018 report found correlations between an increased risk of cancer and chemical poisoning, as well as of respiratory diseases like asthma, are of a much greater likelihood in marginalized communities that are negatively affected by environmental and spatial injustice, because individuals there may be more often be at risk of exposure to dangerous pollutants in water or in the air.
The U.S. E.P.A. defines the urban heat island effect as a phenomenon where urban areas experience higher temperatures than surrounding areas. Air temperature inside urban areas can be about 1–3°C or 1–7°F higher than rural or surrounding air temperatures, on average. This is due to a variety of reasons, which include but are not limited to lower albedo on urban surfaces, anthropogenic heat released from buildings and vehicles, and reduced areas of evapotranspiration. Asphalt and concrete, surfaces that are more common in urban areas, have a higher albedo than surfaces such as trees, grass, or snow. In addition, evapotranspiration is a powerful cooling process, and the relatively reduced amount of greenery in urban areas compared to rural areas contributes to the urban heat island effect. Without urban forests, the cooling mechanisms of high albedo and evapotranspiration do not work to cool the geographic area. Additionally, the E.P.A. has found that lower-income communities and those of color are particularly susceptible to the phenomenon known as intra-urban heat islands, which is due, in part, to historical redlining. As urban forests help combat urban heat islands and intra-urban heat islands, redlining contributes to this instance of environmental injustice.
Examples
Some cities have historically faced problems concerning urban forest inequity. They may have a disproportionate amount of green space in higher-income communities or face criticism from those who advocate for environmental justice. Beijing, China is one of those examples, demonstrated by the lack of accessibility to green spaces compared to gated communities. Research was published in the journal Environment and Planning B: Urban and City Analytics with data from the Beijing Green Spaces System Planning which found that higher-income gated communities had more access to green spaces than lower-income residential communities and that the urban planning was not meeting the demand for public parks and playgrounds in the densely populated regions of the city.
New York City is another example of a city that has historically faced challenges with urban forest inequity. Because of the urban heat island effect, concrete in the city draws more heat and raises temperatures, so more shade coverage is needed to protect inhabitants. A 2023 editorial written for the New York Daily News found that many neighborhoods in the city lack shade protection and may subsequently face temperatures “20 to 45 degrees hotter than those with more shade,” and these are typically lower-income communities. Moreover, researchers have often cited Chicago as another U.S. city facing difficulties in mitigating urban forest inequity. The city is actively trying to combat the lack of greenery and pollution they are facing through planting trees across different neighborhoods.
In 2021, a paper published in the International Journal of Environmental Research and Public Health worked to identify which regions in Delhi, India were experiencing high levels of urban heat, and consequently if they had sufficient green space or areas with urban forestry of some kind. According to the researchers, the results “documented how the spatial distribution of heat and greenspace relates to the spatial distribution of social vulnerability at the ward level in Delhi.” Rafael Fernandez-Alvarez of Arizona State University conducted similar research on Mexico City, Mexico pertaining to the distribution of green public spaces for inhabitants. The researchers found that these spaces are often biased against marginalized populations. The evidence showed that they mostly exist in the wealthy areas of the capital city, while the more populated lower-income communities lacked green public spaces.
Potential solutions
Efforts to address urban forest inequity must effectively combat both environmental and spatial injustice in addition to urban heat islands. Some argue this may include activists and policymakers engaging directly with marginalized communities, public investment in underserved neighborhoods, and tighter government restrictions regarding land use and pollution concerns. A 2023 article published in the National League of Cities offered several potential solutions to combat urban heat islands, which included but are not limited to: increasing green space by planting trees along streets or sidewalks, converting existing roof spaces to green roofs, replacing normal pavement with sustainable alternatives, subsidies for planting trees, and active engagement of low-income communities, among others.
Furthermore, a potential solution to address this issue is the implementation of tree-planting initiatives. These initiatives aim to provide resources and support to historically underserved areas, thereby contributing to a more equitable urban environment. However, it is important to recognize that simply planting trees in low canopy-covered areas may not be sufficient to combat this environmental inequity. Initiatives must adhere to specific practices aligned with urban forest management objectives to ensure the creation of an equitable urban environment.
Moreover, it is important to consider the potential impacts of tree-planting initiatives before their implementation, as they may unintentionally contribute to environmental gentrification. Studies have shown that within a 10-meter buffer of the newly planted street trees, properties tend to experience a notable increase in value, indicating a positive correlation between planting street trees and property values. However, it is worth noting that the rise in property values may not always translate to benefits for underserved communities. To counter eco-gentrification, there are some key practices for tree-planting initiatives to follow, which are described by Sousa-Silva et al. (2023) and Haffner (2015), including integrating initiatives with long-term management strategies, creating community engagement, and introducing changes gradually.
MillionTreesNYC
An example of a tree-planting initiative that is currently ongoing is the Million Tree Initiative. New York City is an example of a city who implemented this initiative in recent years. The city launched the MillionTreesNYC initiative in 2007, which is now recognized as one of the largest and greatest-funded tree-planting initiatives in the United States. This initiative was a collaboration between the New York City Parks Department and the NY Restoration Project (NYPR), resulting in the successful planting of one million trees across five boroughs of New York City in less than a decade. Guided by considerations of health and socioeconomic factors, the initiative targeted neighbourhoods with the greatest lack of trees, aiming to improve urban canopy coverage by 20%. NYPR, a local non-profit organization, actively engaged the community in the planting and maintenance of the newly planted trees. This initiative was supported by collaborations with external partners and had help from volunteers around the city. After the initiative successfully planted one million trees across five boroughs, plans were made to update the street tree census and offer a user-friendly public map of trees to increase community involvement and create a culture of tree stewardship. MillionTreesNYC serves as a notable example of effectively increasing canopy cover in historically underserved areas, inspiring similar efforts in other cities, including Los Angeles.
See also
Environmental justice
Million Tree Initiative
Redlining
Right to a healthy environment
Spatial justice
U.S. Environmental Protection Agency
Urban ecology
Urban forest
Urban heat island
Urban reforestation
References
External links
Heat Islands
The Inequitable Distribution of Urban Trees
Urban forests in Chicago
MillionTreesNYC
Environmental design
Environmental justice
Environmental social science concepts
Environmentalism
Forestry and the environment
Social inequality
Sustainable urban planning
Urban forests
Urban planning | Urban forest inequity | [
"Engineering",
"Environmental_science"
] | 2,441 | [
"Environmental design",
"Environmental social science concepts",
"Urban planning",
"Design",
"Environmental social science",
"Architecture"
] |
75,167,954 | https://en.wikipedia.org/wiki/Scalar%20control | Scalar control of an AC electrical motor is a way to achieve the variable speed operation by manipulating the supply voltage or current ("magnitude") and the supply frequency while ignoring the magnetic field orientation inside the motor. Scalar control is based on equations valid for a steady-state operation and is frequently open-loop (no sensing except for the current limiter). The scalar control has been to a large degree replaced in high-performance motors by vector control that enables better handling of the transient processes. Low cost and simplicity keeps the scalar control in the majority of low-performance motors, despite inferiority of its dynamic performance; vector control is expected to become universal in the future.
Types
The variants of the scalar control include open-loop control and closed-loop control.
Open-loop
The most common approach makes the voltage V proportional to frequency f (so called V/f control, V/Hz control, Constant Volts/Hertz, CVH). Advantage of the V/f variant is in keeping the magnetic flux inside the stator constant thus maintaining the motor performance across the range of speeds. A voltage boost at low frequencies is typically employed to compensate for the resistance of the coils.
An open-loop V/f control works well in applications with near-constant load torque and gradual changes in rotational speed. The controllers implementing this method are sometimes called general purpose AC drives.
Closed-loop
If sensors are utilized (closed-loop configuration) for better/faster transitional response, the common approach uses a rotational speed sensor (so called closed-loop V/Hz control). The speed error is passed through the proportional-integral controller to create the accumulated slip difference that is combined with the direct reading of the speed sensor into a frequency control signal.
In a torque-control variant (TC, not to be confused with the direct torque control a.k.a. DTC), the motor torque is held constant in the steady-state, this requires a current sensor. Frequency and flux (voltage or current, depending on the type of the drive) control signals are decoupled, with the flux control driven by the flux estimate, and the frequency control driven by the torque estimate and speed sensor data. The increased performance comes at the cost of additional complexity and associated potential stability issues.
References
Sources
Electric motors | Scalar control | [
"Technology",
"Engineering"
] | 472 | [
"Electrical engineering",
"Engines",
"Electric motors"
] |
75,168,010 | https://en.wikipedia.org/wiki/PSR%20J1747%E2%88%922958 | PSR J1747-2958 is a young, weak, nonthermal radio pulsar with a rotation period of 98.8 ms (milliseconds). The pulsar moves at a supersonic speed through the interstellar medium forming an unusual nonthermal nebula around it. This nebula around PSR J1747-2958 is also called the "Mouse nebula" or "G359.23-0.82" and it is a axisymmetric nebula.
Discovery
This object was discovered in February 7, 2008, with a 58 ks exposure.
Reference
Pulsars
Astronomical objects discovered in 2008
Sagittarius (constellation) | PSR J1747−2958 | [
"Astronomy"
] | 135 | [
"Sagittarius (constellation)",
"Constellations"
] |
75,168,205 | https://en.wikipedia.org/wiki/Solaris%20%28solar%20power%29 | SOLARIS is a space-based solar power (SBSP) proposal of the European Space Agency (ESA).
The proposal calls for an in-orbit demonstration in approximately 2030, the first operational station in geostationary orbit by 2040 with subsequent stations added afterwards. Each modular solar panel would be almost one 1km wide, with ground receiving antennas about 6km wide each, generating up to a petawatt of power. The program is estimated to be able to supply between a 7th and a 3rd of Europe's current power demand, or 10% of its predicted demand by 2050.
At its November 2022 ministerial council meeting ESA sought funding of a three-year study into the proposal. Having successfully received that approval, in 2023 it commissioned Arthur D. Little and Thales Alenia Space Italy to independently develop "concept studies" for commercial-scale SBSP plants. The "economic, political, and technological feasibility" of continuing the project will be re-assessed at the next ministerial council, in 2025.
In preparation for the 2022 three-year study request, ESA separately commissioned consulting firms Frazer-Nash (UK) and Roland Berger (Germany) assess the potential of the scheme to support the European policy goal of a net-zero carbon economy by 2050:
Criticisms of SOLARIS and other SBSP schemes, even by their proponents, include challenges in at least three areas: whether it is possible to build the technology and logistics required to launch, remotely-assemble, and operate massive satellites; the "policy implications associated with beaming power from space"; and whether it is affordable. Important factors in increasing the feasibility of the proposal has been the recent rapidly decrease in launch cost, as well as advances in robotic manufacturing and wireless energy transfer. A 2022 tests in Germany for the SOLARIS program demonstrated the ability to wirelessly beam power across a distance of 36m, however there is "still a way to go" before it is possible to achieve the same from the distance of geostationary orbit. Earlier in the same year, both the China Academy of Space Technology and the NASA Office of Technology, Policy and Strategy had each approved studies and tests in components of similar schemes.
References
External links
ESA Project homepage
FAQ covering economic, technical, safety, and environmental issues.
Video explanation
Solar power
Solar power and space
Space technology
Space-based economy
European Space Agency programmes | Solaris (solar power) | [
"Astronomy"
] | 484 | [
"Space technology",
"Outer space"
] |
75,168,592 | https://en.wikipedia.org/wiki/Tremella%20brasiliensis | Tremella brasiliensis is a species of fungus in the family Tremellaceae. It produces yellow, lobed to firmly foliaceous, gelatinous basidiocarps (fruit bodies) and is parasitic on other fungi on dead branches of broad-leaved trees. It was originally described from Brazil.
Taxonomy
Tremella brasiliensis was first published in 1895 by German mycologist Alfred Möller as a variety of the superficially similar European species Tremella lutescens (now regarded as a synonym of Tremella mesenterica). It was raised to species level by American mycologist Curtis Gates Lloyd in 1922.
Description
Fruit bodies are gelatinous, whitish to yellow to bright orange-yellow, up to 3 cm (1.5 in) across, and lobed to frondose. Microscopically, the basidia are tremelloid (ellipsoid, with oblique to vertical septa), 4-celled, 25 to 45 by 12 to 30 μm. The basidiospores are globose, smooth, 14 to 20 μm across.
Similar species
Tremella mesenterica, described from Europe but reported from South America, is similarly coloured but has smaller basidia and smaller, ellipsoid spores (10 to 16 by 6 to 9.5 μm). Naematelia aurantia, described from North America but reported from South America, is also bright yellow but is a parasite of Stereum fruit bodies (amongst which it typically occurs) and also has much smaller basidia and spores (5.5 to 9 by 4.5 to 7 μm).
Elsewhere, Tremella philippinensis is equally large-spored and was considered conspecific by Roberts & Spooner. It was originally described as a whitish species or possibly pale yellow, but its status is uncertain. Tremella grandibasidia, described from North America, is another large-spored, yellow species of uncertain status.
Habitat and distribution
Tremella brasiliensis is a parasite on lignicolous fungi, but its host species is unknown. It is found on dead, attached or fallen branches of broad-leaved trees.
The species was described from Brazil and has also been reported from Panama and Costa Rica. Bandoni & Ginns considered that collections from Japan also represented Tremella brasiliensis. Roberts & Spooner treated the species as a synonym of Tremella philippinensis and recorded the latter from Brunei and Australia.
References
brasiliensis
Fungi described in 1895
Fungi of South America
Fungus species | Tremella brasiliensis | [
"Biology"
] | 531 | [
"Fungi",
"Fungus species"
] |
75,169,465 | https://en.wikipedia.org/wiki/IC%202486 | IC 2486 is a Sbc-type spiral galaxy that is located in the constellation of Leo. Other catalog identifiers include PGC 26982, UGC 5062, and LEDA 26982. It is located 638 million light years from Earth and has a diameter of about 160,000 thousand light-years. IC 2486 was discovered by Stéphane Javelle in May 1903.
References
Spiral galaxies
Leo (constellation)
2486
05062
+05-23-006
026982
026982 | IC 2486 | [
"Astronomy"
] | 114 | [
"Leo (constellation)",
"Constellations"
] |
75,169,585 | https://en.wikipedia.org/wiki/IRAS%2006076-2139 | IRAS 06076-2139 is a pair of unusual interacting galaxies located in the constellation of Lepus about 538 million light years from Earth, making it a local universe type galaxy. The two galaxies are fairly close to each other at just 200,000 light years. These two galaxies are interacting and rushing by each other at a speed of 2 million kilometers (1,243,000 miles) per hour. Due to their speed, they are unlikely to merge with each other.
References
Interacting galaxies
Lepus (constellation) | IRAS 06076-2139 | [
"Astronomy"
] | 109 | [
"Lepus (constellation)",
"Galaxy stubs",
"Astronomy stubs",
"Constellations"
] |
75,169,914 | https://en.wikipedia.org/wiki/2MASX%20J16270254%2B4328340 | 2MASX J16270254+4328340 (also known as SDSS J162702.56+432833.9 or PGC 3087775) is a pair of old, local universe merging/interacting elliptical galaxies that are located in the constellation of Hercules about 500 million light years away from Earth. The two galaxies have gravitationally thrown out millions of stars in long tails. The two galaxies are heading into their old age where star formation starts to stop and the galaxy starts to die.
The galaxy has a central blue region. This central blue region are the result of many young blue-white stars being formed as a result of the galactic merging event.
References
2MASS objects
Hercules (constellation)
J162702.56+432833.9
Interacting galaxies | 2MASX J16270254+4328340 | [
"Astronomy"
] | 167 | [
"Hercules (constellation)",
"Constellations"
] |
75,169,953 | https://en.wikipedia.org/wiki/Olivetti%20Valentine | The Olivetti Valentine is a portable, manual typewriter manufactured and marketed by the Italian company, Olivetti, that combined the company's Lettera 32 internal typewriter mechanicals with signature red, glossy plastic bodywork and matching plastic case. Designed in 1968 by Olivetti's Austrian-born consultant, Ettore Sottsass (father of the Memphis Group), who was assisted by Perry A. King and Albert Leclerc, the typewriter was introduced in 1969 and was one of the earliest and most iconic plastic-bodied typewriters.
Despite being an expensive, functionally limited and somewhat technically mediocre product which failed to find success in the marketplace, the Valentine "subverted the status quo" of typewriter design, captured the zeitgeist of post-'68 counterculture, and ultimately became a celebrated international icon, largely on account of its expressive design.
The Valentine is featured in the permanent collections of the Metropolitan Museum of Art, Museum of Modern Art, and Cooper Hewitt, Smithsonian Design Museum in New York; London's Design Museum and Victoria and Albert Museum; the Powerhouse Museum in Sydney; as well as the Triennale di Milano in Milan.
Poet Giovanni Giudici, who was employed with Olivetti, described the Valentine as "a Lettera 32 disguised as a sixties girl." Over time, Sottsass himself – who thought of the Valentine as the Bic Biro/Cristal of typewriters, his oggetto rosso – would tire of its design, calling it "too obvious, a bit like a girl wearing a very short skirt and too much make-up."
Design and development
Olivetti originally conceived the Valentine as a response to the early 1960s flood of inexpensive pragmatically designed manual typewriters from Japan, such as those from Brother and Silver Seiko.
Believing design should not merely be functional but also sensual and emotionally appealing, Sottsass prototyped his ideas in (an early trademarked polypropylene), proposing a very basic but boldly colored and highly affordable design: eliminating lower case letters, exposing its ribbon caps and forgoing a bell for the right hand margin. Sottsass lavished cost-effective and attentive details throughout the design, going so far as to carefully resolve in sketch studies, the negative space around each carriage end.
Olivetti resisted, pushing for more features that would ultimately make the typewriter relatively expensive. Olivetti insisted on more expensive color-impregnated, impact-resistant injection-molded ABS plastic, rather than the prototype's Moplen, as well as both upper and lower case capability and the right margin bell. Following these disagreements, Sottsass distanced himself from the project, despite having largely completed the design as well as its launch advertising campaign. His colleagues, British designer Perry King with Canadian Albert Leclerc, completed the work.
The design itself was surprising and non-conformist, largely deconstructing what would typically be the typewriter's bodywork, revealing elements normally concealed, using 'floating keys' and a body-colored plastic 'rail' ahead of the spacebar, visually detached from the typewriter's main body. Sottsass cited the orange nipples and pink breasts in Tom Wesselmann's paintings of nudes as inspiration for the Valentine's orange ribbon caps; he chose the bright red color to emphasize casual creativity rather than the serious monotony of office work.
At a time when most typewriter cases featured elaborate zippers and bulky suitcase designs, Sottsass proposed an inexpensive injection-molded, color-matched plastic sleeve with softly rounded corners and a textured-finish that could mate to the typewriter's plastic bodywork; the rear "plate" of the typewriter became the top of the case, locking onto the typewriter itself via two black rubber straps/tabs on opposite ends of the case, thus allowing the Valentine to be carried like a briefcase. The case could likewise serve as a trash can or light duty stool when the typewriter was in use. Art historian Deborah Goldberg said a designer expending so much attention on the typewriter case was itself radical.
Details included black plastic keys and white lettering; orange plastic ribbon spool caps, silver metal return arm and paper guide; twin chrome, rabbit-ear style paper supports; black rubber feet; red plastic swing handle at back of typewriter, as well as integral raised "Valentine" lettering along the front and "olivetti" at the rear plate. At introduction, the user manual was printed on a set of small "tags" held together with a loop of string, with cheeky phrasing describing the main functions, accompanied by simple black and white illustrations.
Over the course of production, design revisions included enlarging the orange ribbon caps, and adding two prominent dimples at the top of the bodywork, to help prevent scuffing when removing the typewriter or returning it to its case.
Though often called la rossa portatile (the red portable), the Valentine was also subsequently manufactured in very small numbers in white, blue and green, respectively for Italy, France and Germany.
A number of similar typewriters either preceded or closely emulated the Valentine's design. Notably, the Valentine shared numerous features (including its bold red color, floating black keys, and ABS typewriter body with a pronounced rear plate that mated to a plastic sleeve case) with the Monpti typewriter, designed by Stefan Lengyel in 1968 (the same year the Valentine was designed) for Zbrojovka Brno NP in Vyškov, Czechoslovakia. Furthermore, industrial designer Carl Wilhelm Sundberg (Netherlands, 1910–1982), working for Sperry Rand Corporation, patented a plastic-bodied typewriter in 1963 without specifying ABS for the company's forthcoming, red typewriter, the Remington Starfire. On March 31, 1972, Antares SPA of Milan registered a US trademark for the Antares Lisa, a typewriter with a similar deconstructionist design (floating keys, floating spacebar, with visually detached body-colored "rail" ahead of the spacebar). This was ultimately marketed in the US as the Montgomery Ward Model 22.
Over the course of time, Sottsass saw the design as cloying and came to openly resent the Valentine, saying: "I worked sixty years of my life, and it seems the only thing I did is this fucking red machine. And it came out a mistake. It was supposed to be a very inexpensive portable, to sell in the market like [a disposable pen] ... then the people at Olivetti said you cannot sell this."
Advertising and sales
Sottsass wanted the Valentine to have its own distinct image, that would "prevail over the global image of Olivetti." Together, they committed to creating the market for the Valentine, prioritizing the demographic that might appreciate the typewriter's design statement as a leisure item, as much if not more than its mechanical specification. It would appeal to "young people or people with a youthful sensibility, open to the appeal of the new and fashionable," the advertisements for the Valentine portraying "a desire to be creative and take risks."
Olivetti conducted extensive market research. In Olivetti's marketing statement at the Valentine's introduction, Sottsass noted:
Since they asked us to think about designing the ad(s) for this product as well, we tried to do something that represented and explained these ideas, and we went to put the Valentine in as many places as possible to see how it behaved and what was happening around it and we took a lot of photographs.
So after a while we came into possession of a large documentation, a sort of reportage of the journey made among people by an object instead of a person, and it didn't even go that bad, because everyone was quite happy to play with this Valentine and to be together with her and for the rest she too, this red object, ended up blending in quite well with the things that already exist in the world, the natural things and the artificial things that make this great confusion in which we live.
The launch advertising ultimately used a range of graphic artists: Sottsass himself along with Roberto Pieraccini, , , Tadaaki Kanasashi, Tesro Itoh, Yoshitaro Isaka, George Leavitt, Graziella Marchi, Adrianus Van Der Elst and Milton Glaser, playing off the painting The Death of Procris (circa 1495) by Piero di Cosimo, depicted the Valentine in a renaissance setting with a dog, suggesting that "it, too, was man’s best friend."
The Valentine was positioned as a mass consumer product that anyone could use anywhere. Large posters were posted on city streets, in subways and railway; radio spots announced its arrival along with advertisements in popular magazines. Olivetti also commissioned a series of short, avant garde video advertising spots (available on Youtube) to be played before movies, during the previews, including: Woman with cigar; Write From the Heart; Woman in Space; Young Japanese; Boy with Motorcycle; Young Hippies; Pinball; and The Red Portable.
At Olivetti's 1969 presentation, Sottsass announced, "the portable, today, becomes an object that one carries with him like one wears a jacket, shoes, or hat; I mean those things that we pay attention to and don't pay attention to; things that come and go, things that we tend to demystify more and more".
The Valentine was formally introduced on Valentine's Day 1969 to a largely unreceptive market. Production took place initially in Italy, then later in Spain and Mexico. At introduction in the United States the Valentine retailed for $259, when a Royal Mercury metal bodied ultra-portable retailed for $49. While Olivetti had projected sales in the millions, the Valentine managed sales in the few tens of thousands; it was initially retired and only returned to production by popular demand.
In popular culture
Brigitte Bardot was photographed with a Valentine; in 1970 Richard Burton and Elizabeth Taylor were photographed at Heathrow Airport carrying a Valentine; and the Valentine was used by the main character in Stanley Kubrick’s A Clockwork Orange (1971). Braun-Designer Dieter Rams owned a Valentine. It appeared in the 2007 film The Witnesses.
In 1999, in its home town of Ivrea, the Olivetti Historical Archive mounted an exhibition honouring the 30th Anniversary of the Valentine, titled Rosso, Rosso Valentine, subsequently replicated in Milan, Prague, Budapest, Genoa and Turin.
In 2016, David Bowie's Valentine typewriter sold at an auction at Sotheby's in London for £45,000, against a presale estimate of £300–£500.
In 2017, Peter Olivetti, great grandson of Camillo Olivetti, founder of the Olivetti corporation, created a tribute to the Valentine as a bicycle, using the 100th anniversary Cento tubeset created by the Italian company, Columbus. It featured details recalling the typewriter: the color, the three small dots of color recalling the typewriters ribbon selection, and an orange dot on the pump recalling the ribbon caps.
See also
Olivetti typewriters (all models)
Olivetti S.p.A.
References
Explanatory notes
External links
Olivetti website
Collections in Motion: Valentine Typewriter (Brief film by the Cooper Hewitt, Smithsonian Design Museum)
La Valentine della Olivetti: Macchina da scrivere icona del design (Rai Cultura television programme with Ettore Sottsass)
Typewriters
Valentine
Industrial design
1960s in Italy
Products introduced in 1969
Pop art
Italian design
Design history
Product design
Collection of the Museum of Modern Art (New York City)
Collection of the Metropolitan Museum of Art
Collection of the Victoria and Albert Museum
Collection of the Powerhouse Museum
Articles containing video clips | Olivetti Valentine | [
"Engineering"
] | 2,462 | [
"Industrial design",
"Design engineering",
"Design history",
"Product design",
"Design"
] |
75,170,113 | https://en.wikipedia.org/wiki/Blue%20Nugget | Blue Nugget (also called BN) galaxies are a type of distant galaxy that only existed in the early universe. Blue nugget galaxies are small but high mass galaxies undergoing mass bursts of star formation, making many large, bright blue stars. As their stellar population evolves and ages, blue nugget galaxies transition into red nugget galaxies.
"Blue" derives from their blue coloration and "Nugget" derives from their small size.
Examples of Blue Nugget galaxies:
KIDS J232940-340922
KIDS J122456+005048
References
Galaxies | Blue Nugget | [
"Astronomy"
] | 122 | [
"Galaxies",
"Astronomical objects"
] |
75,170,881 | https://en.wikipedia.org/wiki/KIDS%20J232940-34092 | KIDS J232940-34092 is a massive quadruple lens compact post-blue nugget type galaxy that is located at Redshift 0.38, meaning it is located about 5.2 billion light years from Earth. It has an Einstein cross effect, an effect where light from a distant galaxy comes across a region of spacetime that is warped (gravitational lensed) by a massive galaxy in the lights path. It was discovered along with KIDS J122456+005048, another blue nugget galaxy with a Einstein cross.
The galaxy has a evolved stellar population of very little stellar formation. This was discovered due to the galaxy's prominent absorption features.
Reference
Galaxies discovered in 2020
Pisces (constellation) | KIDS J232940-34092 | [
"Astronomy"
] | 154 | [
"Pisces (constellation)",
"Galaxy stubs",
"Astronomy stubs",
"Constellations"
] |
75,170,937 | https://en.wikipedia.org/wiki/Garden%20Island%20Tunnel%20System | The Garden Island Tunnel System, also known as Garden Island tunnels, Garden Island Tunnel Complex and Potts Point Tunnels, is a former tunnel warfare system in Garden Island, Sydney, Australia. Used in World War II by the Royal Australian Navy in 1941, the tunnels were dug from sandstone beneath Potts Point after the Japanese attacked Pearl Harbor, to shelter the men working at the naval base from air raids. Some of the tunnels feature names such as Petticoat Lane (named after London's landmark), North-West Passage and Lambeth Walk.
The tunnel system featured a power station, a command centre, offices and air raid shelters. Today, the tunnels and chambers are used for electrical wiring and communications.
History
Construction
Four days after the Japanese air-raided Pearl Harbor on December 7, 1941, excavation began on the tunnels in Potts Point. The tunnel system was approved at an estimated cost of £15,150. After Sydney's shelling in June 1942, this pushed the exigent to excavate the five interlinked tunnels and multiple chambers underneath the base's northern point. A second tunnel system that runs all the way to Kings Cross exists, but little is known about it.
The Garden Island tunnels are perfectly straight, resembling a wild west mine, and concrete-lined with dented cuts into the rock for stretcher-bearing, casualty clearing stations, backup generators, telephone exchange, bathrooms and toilet facilities, some of which are located in the northernmost bunker. Other tunnels were constructed to store pumping valves at the Captain Cook Graving Dock.
World War II
In early 1941, former prime minister of Australia and minister for the navy, Billy Hughes, stated that he did not want to alarm people by having them think Sydney was about to be bombarded. Hughes organized over a hundred of brodie helmets for the air raid officers and as well as training them in case if a chemical warfare were to occur. A pit constructed in the 1800s would have been used to store provisions if the island were to be sieged.
In December 1941, due to concerns that an aerial attack on Sydney could follow the Pearl Harbor bombing, the five tunnels were constructed to provide an airstrike shelter for the 2,500 waterfront staff at Garden Island Naval Base, in case the Royal Australian Navy base that lies there were attacked. The tunnel system would have been able to protect the workers on Garden Island from 70 tons of bombs dropped within 24 hours. Though the tunnels did not provide room for the public population, as civilians could have sought cover in the proximate railway stations of Sydney. The tunnels were also used to transport guns and ammunition from one side of the island to the other side.
The demand for protection from air attack became more serious in 1942, when Japan occupied Singapore on 15 February, and attacked Darwin on 19 February, and eventually, on 31 May, when three Japanese midget submarines entered and attacked the Sydney Harbour.
Post-war
In the 1960s, there still existed some tables, papers on walls and old telephones, but the tunnel complex became abandoned and the roof timber set either decayed or it got consumed by termites. In the 1970s, the tunnels were renovated with new steel roof supports and concrete after the fleecy sandstone walls and timber struts became weathered. Today, the tunnels are primarily used for storage and to provide fuel and communication lines at the naval base.
Upgrade
As of October 2023, the defense base in the tunnels is going through a half-a-billion dollar, three-year infrastructure upgrade. The warship wharves have been adjusted, in addition to replacement of a fuel tank for the ships and improvement to the island's structure that includes fuel, electricity, sewerage and water, which run through the tunnels. A part of Petticoat Lane, which was used to insulate boilers and pipage on ships, is gated off with a warning sign that indicates the presence of asbestos.
See also
Sydney Harbour defences
Bradleys Head Fortification Complex
Georges Head Battery
Middle Head Fortifications
References
Tunnels in Sydney
Tunnel warfare
Tunnels completed in 1941
Forts in New South Wales
History of Sydney
Buildings and structures in Sydney
Former military installations in New South Wales
World War II sites in Australia
Sydney in World War II
Bunkers in Oceania | Garden Island Tunnel System | [
"Engineering"
] | 855 | [
"Military engineering",
"Tunnel warfare"
] |
75,171,040 | https://en.wikipedia.org/wiki/Dead%20disk | A dead disk galaxy is a type of galaxy that is no longer able to form new stars. These galaxies are usually massive yet compact, fast spinning disk shaped galaxies. Most of these galaxies stopped forming new stars billions of years ago when the universe was relatively young in age. These types of galaxies are thought to have been formed by an early phase of intense star birth and evolved into a local elliptical galaxy, like that seen in our modern universe.
These types of galaxies challenge astronomers' view of the evolution of galaxies and the chronology of the universe, as they expect to find a more chaotic universe, with many merging galaxies and balls of chaotic stars; instead, dead disk galaxies are flat disks with very little or no stellar formation.
References
Galaxies | Dead disk | [
"Astronomy"
] | 148 | [
"Galaxies",
"Astronomical objects"
] |
75,172,586 | https://en.wikipedia.org/wiki/CB%20130-3 | CB 130-3 (also known as LDN 507) is a dense carbon-chain rich molecular cloud located in the constellation of Serpens about 253 light years (200 pc) away from Earth. Objects like CB 130-3 form many new stars through stellar formation. The central dense areas are dark orange clouds surrounded by a light blue haze of gas. The central dense cloud of gas blocks out background light from stars entirely.
Reference
Molecular clouds | CB 130-3 | [
"Astronomy"
] | 92 | [
"Constellations",
"Serpens"
] |
75,173,601 | https://en.wikipedia.org/wiki/Susan%20Murabana | Susan Murabana Owen is a Kenyan astronomer. The co-founder of Travelling Telescope, she is known for her efforts to promote science, technology, engineering and mathematics in Africa, particularly among girls.
Early life and education
Murabana grew up in Nairobi, Kenya, and studied sociology and economics at the city's Catholic University of Eastern Africa. In 2011, she graduated with a master's degree in astronomy from James Cook University in Australia, having studied online. Murabana has cited African American astronaut Mae Jemison and Kenyan environmentalist Wangari Maathai as her heroes.
Astronomy career
Voluntary work
Murabana first became interested in space when she was in her twenties, when her uncle invited her to attend a science outreach programme in Mumias, Kakamega County, facilitated by Cosmos Education. She subsequently became a volunteer for the organisation, and later went on to work with the International Astronomical Union's Global Hands-on Universe programme.
Travelling Telescope
In 2013, Murabana met her future husband, Daniel "Chu" Owen, at the November 2013 solar eclipse at Lake Turkana in the Kenyan Rift Valley. Owen had previously established Travelling Telescope, in which he had travelled around his home country, the United Kingdom, allowing the public to look at space through his telescope. In 2014 and 2015, Travelling Telescope was relaunched in Kenya as a social enterprise aiming to educate poor and remote communities about science and astronomy. The organisation raises money by holding private events, such as the annual Shooting Star Safari in Samburu County during the Perseids meteor shower, as well as providing astronomy services to private schools and safari lodges. The money is subsequently used to provide free outreach work to state schools and remote communities throughout Kenya.
Travelling Telescope's outreach work includes using Sky-Watcher Flextubes to allow people to see planets including Jupiter, Mars, Saturn and Venus; the Orion and Trifid nebulae; and the Pinwheel and Andromeda galaxies. The organisation has an inflatable planetarium, and in 2020 established the Nairobi Planetarium, East Africa's first permanent planetarium, constructed out of bamboo. Murabana has also run space camps in Nairobi.
During the COVID-19 pandemic, Travelling Telescope received funding from the Airbus Foundation to establish online classes in astronomy, rocketry and robotics for African schoolchildren.
Other work
Murabana has served as a national advisor for Kenya at Universe Awareness; the African representative on the International Planetarium Association; and as a board member for World Space Week. She is also the president of the African Planetarium Association, which aims to establish more permanent planetariums around the continent.
In 2021, Murabana was named as a Space4Women mentor, as part of the United Nations' women in STEM programming.
Recognition
In 2020, Murabana and Travelling Telescope was awarded the Europlanet Award for Science Engagement. Her work has been featured in BBC News, Deutsche Welle and the Christian Science Monitor.
References
Living people
Scientists from Nairobi
21st-century Kenyan women scientists
Women astronomers
Catholic University of Eastern Africa alumni
James Cook University alumni
21st-century astronomers
Year of birth missing (living people) | Susan Murabana | [
"Astronomy"
] | 641 | [
"Women astronomers",
"Astronomers"
] |
75,173,883 | https://en.wikipedia.org/wiki/Cadmium%20azide | Cadmium azide is an inorganic chemical compound with the formula . It is composed of the cadmium cation () and the azide anions ().
Properties
Cadmium azide is colorless and crystalline powder. It is highly sensitive to pressure, and is explosive akin to most other azides. It has a high temperature resistance, and also possesses good detonation ability. Because of this, cadmium azide is expected to be applicable within microinitiating systems.
References
azide
cadmium | Cadmium azide | [
"Chemistry"
] | 105 | [
"Explosive chemicals",
"Azides",
"Inorganic compounds",
"Inorganic compound stubs"
] |
61,475,383 | https://en.wikipedia.org/wiki/BEAMA | BEAMA, formerly the British Electrotechnical and Allied Manufacturers' Association, is a trade association for energy infrastructure companies in the United Kingdom.
History
The organisation was established in 1902 as the National Electrical Manufacturers' Association before changing its name to the British Electrotechnical and Allied Manufacturers' Association in 1911.
The first director was Daniel Nicol Dunlop, also chairman of the first World Power Conference (now the World Energy Council) in 1924.
A collection of the organisation's records for the period 1905 to 1986 is held in the Modern Records Centre of the University of Warwick covering the subjects of trolley buses, electric welding, electric railroads, the electric industries, and the training of electrical engineers.
Activities
BEAMA lobbies on behalf of energy infrastructure companies in the United Kingdom.
Selected publications
The Electrical Industry of Great Britain (1929)
See also
Hugh Quigley
References
External links
1902 establishments in the United Kingdom
Trade associations based in the United Kingdom
Business organisations based in London
Electrical engineering organizations | BEAMA | [
"Engineering"
] | 195 | [
"Electrical engineering",
"Electrical engineering organizations"
] |
61,475,631 | https://en.wikipedia.org/wiki/Biorheology%20%28journal%29 | Biorheology is a scientific journal in the field of biorheology, the study of the deformation and flow properties (rheology) of biological fluids, published by IOS Press. It is published quarterly since 2018. It was established in 1962 by founding editors A.L. Copley and G.W. Scott Blair.
It is currently edited by Herbert H. Lipowsky (Penn State University) and Brian M. Cooke (Australian Institute of Tropical Health and Medicine).
References
Rheology
Physics journals
Biology journals
IOS Press academic journals
Quarterly journals
Academic journals established in 1962 | Biorheology (journal) | [
"Chemistry"
] | 120 | [
"Rheology",
"Fluid dynamics"
] |
61,475,737 | https://en.wikipedia.org/wiki/List%20of%20named%20differential%20equations | Differential equations play a prominent role in many scientific areas: mathematics, physics, engineering, chemistry, biology, medicine, economics, etc. This list presents differential equations that have received specific names, area by area.
Mathematics
Ablowitz-Kaup-Newell-Segur (AKNS) system
Clairaut's equation
Hypergeometric differential equation
Jimbo–Miwa–Ueno isomonodromy equations
Painlevé equations
Picard–Fuchs equation to describe the periods of elliptic curves
Schlesinger's equations
Sine-Gordon equation
Sturm–Liouville theory of orthogonal polynomials and separable partial differential equations
Universal differential equation
Algebraic geometry
Calabi flow in the study of Calabi-Yau manifolds
Complex analysis
Cauchy–Riemann equations
Differential geometry
Equations for a minimal surface
Liouville's equation
Ricci flow, used to prove the Poincaré conjecture
Tzitzeica equation
Dynamical systems and Chaos theory
Rabinovich–Fabrikant equations
Mathematical physics
General Legendre equation
Heat equation
Laplace's equation in potential theory
Poisson's equation in potential theory
Ordinary Differential Equations (ODEs)
Bernoulli differential equation
Cauchy–Euler equation
Riccati equation
Hill differential equation
Riemannian geometry
Gauss–Codazzi equations
Physics
Astrophysics
Chandrasekhar's white dwarf equation
Lane-Emden equation
Emden–Chandrasekhar equation
Hénon–Heiles system
Classical mechanics
Electromagnetism
Bloch equations
Continuity equation for conservation laws
Maxwell's equations
Poynting's theorem
Fluid dynamics and hydrology
General relativity
Einstein field equations
Friedmann equations
Geodesic equation
Mathisson–Papapetrou–Dixon equations
Schrödinger–Newton equation
Materials science
Ginzburg–Landau equations in superconductivity
London equations in superconductivity
Poisson–Boltzmann equation in molecular dynamics
Nuclear physics
Radioactive decay equations
Plasma physics
Gardner equation
Hasegawa–Mima equation
KdV equation
Kuramoto–Sivashinsky equation
Vlasov equation
Quantum mechanics and quantum field theory
Dirac equation, the relativistic wave equation for electrons and positrons
Gardner equation
Klein–Gordon equation
Knizhnik–Zamolodchikov equations in quantum field theory
Nonlinear Schrödinger equation in quantum mechanics
Schrödinger's equation
Schwinger–Dyson equation
Yang-Mills equations in gauge theory
Thermodynamics and statistical mechanics
Boltzmann equation
Continuity equation for conservation laws
Diffusion equation
Heat equation
Kardar-Parisi-Zhang equation
Kuramoto–Sivashinsky equation
Liñán's equation as a model of diffusion flame
Maxwell relations
Zeldovich–Frank-Kamenetskii equation to model flame propagation
Waves (mechanical or electromagnetic)
D'Alembert's wave equation
Eikonal equation in wave propagation
Euler–Poisson–Darboux equation in wave theory
Helmholtz equation
Engineering
Electrical and Electronic Engineering
Chua's circuit
Liénard equation to model oscillating circuits
Nonlinear Schrödinger equation in fiber optics
Telegrapher's equations
Van der Pol oscillator
Game theory
Differential game equations
Mechanical engineering
Euler–Bernoulli beam theory
Timoshenko beam theory
Nuclear engineering
Neutron diffusion equation
Optimal control
Linear-quadratic regulator
Matrix differential equation
PDE-constrained optimization
Riccati equation
Shape optimization
Orbital mechanics
Clohessy–Wiltshire equations
Planar reentry equations
Signal processing
Filtering theory
Kushner equation
Zakai equation
Rudin-Osher-Fatemi equation in total variation denoising
Transportation engineering
Law of conservation in the kinematic wave model of traffic flow theory
Chemistry
Allen–Cahn equation in phase separation
Cahn–Hilliard equation in phase separation
Chemical reaction model
Brusselator
Oregonator
Master equation
Rate equation
Streeter–Phelps equation in water quality modeling
Biology and medicine
Population dynamics
Arditi–Ginzburg equations to describe predator–prey dynamics
Kolmogorov–Petrovsky–Piskunov equation (also known as Fisher's equation) to model population growth
Lotka–Volterra equations to describe the dynamics of biological systems in which two species interact
Economics and finance
Linguistics
Replicator dynamics in evolutionary linguistics
Military strategy
Lanchester's laws in combat modeling
References
Differential equations
named differential equations | List of named differential equations | [
"Mathematics"
] | 874 | [
"Mathematical objects",
"Differential equations",
"Equations",
"Mathematical tables",
"Lists of equations"
] |
61,476,013 | https://en.wikipedia.org/wiki/Clean%20Energy%20Institute | The Clean Energy Institute (CEI) is a research institute at the University of Washington. Founded in 2013, the institute maintains several facilities across the university's Seattle campus and supports renewable energy technology research, education, entrepreneurship, and outreach. The institute is under the direction of Daniel T. Schwartz.
History and operations
The Clean Energy Institute is based in the Molecular Engineering and Sciences building at the University of Washington's Seattle campus. It was founded in 2013 with a $6 million grant from the state of Washington for the purposes of supporting solar power and energy storage research and development. This includes research projects led by the university's own academic labs, private companies, and the government.
The institute's primary research facility is the Washington Clean Energy Testbeds (WCET), which opened in 2017 and was funded by an additional $8 million state grant approved by governor Jay Inslee. Located next to University Village near the main campus, the facility allows both academic and private sector users to rent lab space, utilize testing equipment, and consult staff for assistance in their research projects. Equipment at the WCET include battery device testers, solar simulators and solar cell testers, a systems integration lab where users can test devices under real-time or simulated power grids to evaluate energy generation and storage strategies, and a roll-to-roll printer which GeekWire described as "one of the most advanced roll-to-roll systems in the world."
The institute also maintains the Research Training Testbed, which is located in the Nanoengineering and Sciences Building on the university's main campus.
Research
The Clean Energy Institute's main research areas include battery and solar photovoltaic technology as well as grid management. The institute has supported projects relating to perovskites, which have often focused on improving the material properties of thin-film perovskite cells as well as exploring the use of high-throughput manufacturing processes for producing such devices.
Future expansion
In 2018, the state of Washington allocated $20 million to construct a new building on the west side of the UW's Seattle campus called the Center for Advanced Materials and Clean Energy Technologies (CAMCET). The CAMCET building will ultimately house the Clean Energy Institute and the Washington Clean Energy Testbeds as well as the Northwest Institute for Materials Physics, Chemistry, and Technology, and it will include lab and office space for research and collaboration. Construction is scheduled to begin in late 2020, and the building is expected to open by the year 2023.
References
External links
Clean Energy Institute
University of Washington
Energy research institutes
2013 establishments in Washington (state)
Renewable energy in the United States
Research institutes established in 2013 | Clean Energy Institute | [
"Engineering"
] | 544 | [
"Energy research institutes",
"Energy organizations"
] |
61,478,558 | https://en.wikipedia.org/wiki/Army%20Special%20Operations%20Brigade | The Army Special Operations Brigade, previously called the Specialised Infantry Group, is a formation of the British Army, initially created as a result of the Army 2020 Refine reorganisation, intended to train foreign forces. Its name and role was adapted after the Defence in a Competitive Age reforms, to a unit that not only trains partner nations, but also fights alongside them in "complex high-threat environments".
History
Specialised Infantry Group
The group was formed to work alongside partner forces, a role which has similarities to that of the US Army Security Force Assistance Brigades. Initially formed in October 2017 with the 4th Battalion, The Rifles (4 Rifles) and Royal Scots Borderers, 1st Battalion, Royal Regiment of Scotland (1 Scots). in July 2018, the 2nd Battalion, Princess of Wales' Royal Regiment was added to the Group. and in January 2019, a fourth battalion, the 2nd Battalion, Duke of Lancaster's Regiment, was added and this was followed by the 3rd Battalion, The Royal Gurkha Rifles in 2020.
In February 2018, 4 Rifles deployed for the first time to Kuwait to work with the Kuwait Army and Kuwait National Guard. R Company, It also trained the Afghan Army and forces in Iraq and Afghanistan. In July 2018, C Company from the 2 PWRR was dispatched to Nigeria, where 1 Scots also trained the Nigerian Army for their fight against Boko Haram.
Army Special Operations Brigade
In August 2021 the group was re-designated as the Army Special Operations Brigade, with the four battalions of the newly created Ranger Regiment and two reinforcement companies of the Royal Gurkha Rifles along with 255 Signal Squadron under command, and 1 Squadron Honourable Artillery Company attached to provide long-range surveillance patrols.
The mentoring and training role that was previously undertaken by the Specialised Infantry Group, will be taken on by a new brigade, formed through the conversion of 11th Infantry Brigade, into the 11th Security Force Assistance Brigade.
The inaugural Brigade Commander was Brigadier Angus Fair DSO* OBE who formerly commanded the Specialised Infantry Group.
By 2024, the brigade had been transferred from the disbanded 6 (UK) Division to Field Army Troops.
Structure
Former Structure (2021)
The structure of the Specialised Infantry Group in March 2021 was as follows:
Group Headquarters at Saint Omer Barracks, Aldershot Garrison
Royal Scots Borderers, 1st Battalion, Royal Regiment of Scotland (1 SCOTS), at Palace Barracks, Belfast
2nd Battalion, Princess of Wales's Royal Regiment (2 PWRR), at Keogh Barracks, Mytchett
2nd Battalion, Duke of Lancaster's Regiment (2 LANCS), at Elizabeth Barracks, Pirbright Camp
4th Battalion, The Rifles (4 RIFLES), at Normandy Barracks, Aldershot Garrison
3rd Battalion, The Royal Gurkha Rifles (3 RGR), at Aldershot Garrison
Future Structure (2030)
The future structure of the brigade (by 2030) will be:
Brigade Headquarters at Saint Omer Barracks, Aldershot Garrison
255 Signal Squadron, Royal Corps of Signals, at Swinton Barracks, Perham Down (Aldershot from 2027)
1st Battalion, Ranger Regiment (1 RANGER), at Palace Barracks, Belfast
2nd Battalion, Ranger Regiment (2 RANGER), at Keogh Barracks, Mytchett
F (Falklands) Company, The Royal Gurkha Rifles
3rd Battalion, Ranger Regiment (3 RANGER), at Elizabeth Barracks, Pirbright Camp
4th Battalion, Ranger Regiment (4 RANGER), at Normandy Barracks, Aldershot Garrison
G (Coriano) Company, The Royal Gurkha Rifles
Joint Counter Terrorist Training and Advisory Team, at Risborough Barracks, Shorncliffe Army Camp
1 Squadron, Honourable Artillery Company will provide Special Patrols to the Brigade.
See also
11th Security Force Assistance Brigade – British Army formation taking on the role of the former Spec Inf Gp.
Security Force Assistance Brigade – American equivalent to 11th Security Force Assistance Brigade and Special Operations Brigade.
References
External links
Army Special Operations Brigade
Infantry brigades of the British Army
Military units and formations established in 2017
Future Soldier | Army Special Operations Brigade | [
"Engineering"
] | 816 | [
"Military projects",
"Future Soldier"
] |
61,478,670 | https://en.wikipedia.org/wiki/Compact%20Toroidal%20Hybrid | The Compact Toroidal Hybrid (CTH) is an experimental device at Auburn University that uses magnetic fields to confine high-temperature plasmas. CTH is a torsatron type of stellarator with an external, continuously wound helical coil that generates the bulk of the magnetic field for containing a plasma.
Background
Toroidal magnetic confinement fusion devices create magnetic fields that lie in a torus. These magnetic fields consist of two components, one component points in the direction that goes the long way around the torus (the toroidal direction), while the other component points in the direction that is the short way around the torus (the poloidal direction). The combination of the two components creates a helically shaped field. (You might imagine taking a flexible stick of candy cane and connecting the two ends.) Stellarator type devices generate all required magnetic fields with external magnetic coils. This is different from tokamak devices where the toroidal magnetic field is generated by external coils and the poloidal magnetic field is produced by an electrical current flowing through the plasma.
The CTH device
The main magnetic field in CTH is generated by a continuously wound helical coil. An auxiliary set of ten coils produces a toroidal field much like that of a tokamak. This toroidal field is used to vary the rotational transform of the confining magnetic field structure. CTH typically operates at a magnetic field of 0.5 to 0.6 tesla at the center of the plasma. CTH can be operated as a pure stellarator, but also has ohmic heating transformer system to drive electrical current in the plasma. This current produces a poloidal magnetic field that, in addition to heating the plasma, changes the rotational transform of the magnetic field. CTH researchers study how well the plasma is confined while they vary the source of rotational transform from external coils to plasma current.
The CTH vacuum vessel is made of Inconel 625, which has a higher electrical resistance and lower magnetic permeability than stainless steel.
Plasma formation and heating is achieved using 14 GHz, 10 kW electron cyclotron resonance heating (ECRH). A 200 kW gyrotron has recently been installed on CTH. Ohmic heating on CTH has an input power of 100 kW.
Operations
Plasmas electron temperatures are typically up to 200 electronvolts with electron densities up to 5 m−3.
Plasmas last between 60 ms and 100 ms
It takes 6 min-7 min to store enough energy to power the magnet coils
Subsystems
The following gives a list of subsystems needed for CTH operation.
a set of 10 GE752 motors with attached 1-ton flywheels to store energy and produce currents for magnetic field generation
two 18 GHz klystrons for Electron cyclotron resonance heating
gyrotron for 2nd harmonic Electron cyclotron resonance heating
a 2 kV, 50 μF capacitor bank and a 1 kV, 3 F capacitor bank to power the ohmic system
a 640 channel data acquisition system
Diagnostics
The CTH has a large set of diagnostics to measure properties of plasma and magnetic fields. The following gives a list of major diagnostics.
4-channel Interferometer for electron density measurements
two color soft-X-ray camera for tomography and temperature profile
soft x-ray spectrometer
hard x-ray detector
Coils for measuring Mirnov oscillations in the plasma
Rogowski coils for determining plasma current
Passive spectroscopy for temperature and density measurements, and tungsten erosion diagnostic measurements
Langmuir probe (triple)
V3FIT
V3FIT is a code to reconstruct the equilibrium between the plasma and confining magnetic field in cases where the magnetic field is toroidal in nature, but not axisymmetric as is the case with tokamak equilibria. Because stellarators are non-axisymmetric, the CTH group uses the V3FIT and VMEC codes for reconstructing equilibria. The V3FIT code uses as inputs the currents in the magnetic confinement coils, the plasma current, and data from the various diagnostics such as the Rogowski coils, SXR cameras, and interferometer. The output of the V3FIT code includes the structure of the magnetic field, and profiles of the plasma current, density, and SXR emissivity. Data from the CTH experiment was and continues to be used as a testbed for the V3FIT code which has also used for equilibrium reconstruction on the Helically Symmetric eXperiment (HSX), Large Helical Device (LHD), and Wendelstein 7-X (W7-X) stellarators, and the Reversed-Field eXperiment (RFX) and Madison Symmetric Torus (MST) reversed field pinches.
Goals and major achievements
CTH has made and continues to make fundamental contributions to the physics of current carrying stellarators. CTH researchers have studied disruption limits and characterizations as a function of the externally applied rotational transform (due to external magnet coils) for:
Low safety factor (low-q) tokamak-like disruption avoidance
Vertical displacement events (VDEs)
Ongoing experiments
CTH students and staff work on a number of experimental and computational research projects. Some of these are solely in house while others are in collaboration with other universities and national laboratories in the United States and abroad. Current research projects include:
Density limit studies as a function of the vacuum rotational transform
Using spectroscopic techniques to measure tungsten erosion with the DIII-D group
Measuring plasma flows with a Coherence Imaging system on CTH and on the W-7X stellarator
Heavy ion transport studies on the W-7X stellarator
Studying transition regions between fully ionized and neutrally dominated plasmas
Implementation of a 4th channel for the interferometer system
2nd harmonic electron cyclotron resonance heating with a gyrotron
History
CTH is the third torsatron device to be built at Auburn University. Previous Magnetic Confinement Devices built at the university were:
The Auburn Torsatron (1983–1990)
The Auburn Torsatron had an l=2, m=10 helical coil. The vacuum vessel had a major radius was Ro = 0.58 m with a minor radius of av=0.14 m. The magnetic field strength was |B| ≤ 0.2 T and plasmas were formed with ECRH using a 2.45 GHz magnetron taken from a microwave oven. The Auburn Torsatron was used to study basic plasma physics and diagnostics, and magnetic surface mapping techniques
The Compact Auburn Torsatron (1990–2000)
The Compact Auburn Torsatron (CAT) had two helical coils, an l=1,m=5 and an l=2,m=5 whose currents could be controlled independently. Varying the relative currents between the helical coils modified the rotational transform. The vacuum vessel major radius was Ro = 0.53 m with a plasma minor radius of av=0.11 m. The steady state magnetic field strength was |B| 0.1 T. CAT plasmas were formed with ECRH using a low ripple, 6 kW, 2.45 GHz magnetron source. CAT was used to study magnetic islands, magnetic island minimization, and driven plasma rotations
Other Stellarators
Below is a list of other Stellarators in the US and around the world:
Wendelstein 7-X in Greifswald Germany
The Large Helical Device (LDH) in Japan
The National Compact Stellarator Experiment (NCSX) - A device designed and partially built at Princeton Plasma Physics Laboratory (PPPL)
The Helically Symmetric Experiment at the University of Wisconsin - Madison
The Hybrid Illinois Device for Research and Applications (HIDRA) experiment at the University of Illinois
The Columbia Non-neutral Torus (CNT) at Columbia University in New York
The Heliotron J experiment in Japan
The TJ-II in Spain
The Stellarator of Costa Rica (SCR-1)
Uragan-2M in Ukraine
References
External links
CTH website
Physics Department
Auburn University
Plasma physics facilities
Stellarators
Auburn University | Compact Toroidal Hybrid | [
"Physics"
] | 1,680 | [
"Plasma physics facilities",
"Plasma physics"
] |
61,478,925 | https://en.wikipedia.org/wiki/Cat%20exercise%20wheel | A cat exercise wheel is a large wheel on which a cat either runs on or walks on for exercise or play. A cat wheel looks like a large hamster wheel: the wheel turns due to the weight of the cat as it walks. A wheel can be used for enrichment or to exercise high-energy indoor cats.
Indoor cats
Many pet cats are kept in homes or small apartments, and do not have opportunities to run outdoors or otherwise exercise a considerable amount, as they are generally not leash-trained or let outside. A cat wheel can assist cats in maintaining a healthy weight and body condition, as well as providing mental stimulation and a form of play.
See also
Cat toys
Behavioral enrichment
Treadwheel
References
External links
Article from ASPCA's Virtual Pet Behaviorist on cat toys
Opportunities, prerequisites, pros and cons (in German)
Hazards of cat toys (ASPCA)
Cat behavior
Cat equipment
Play (activity)
Toys
Animal welfare
Wheels | Cat exercise wheel | [
"Biology"
] | 195 | [
"Play (activity)",
"Behavior",
"Human behavior"
] |
61,479,470 | https://en.wikipedia.org/wiki/NGC%204305 | NGC 4305 is a dwarf spiral galaxy located about 100 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer John Herschel on May 2, 1829. Although considered to be a member of the Virgo Cluster, its high radial velocity and blue luminosity suggest it is in fact a background galaxy. The galaxy has a nearby major companion; NGC 4306.
NGC 4305 exhibits well-defined, smooth spiral arms which terminate well outside its central bulge. This spiral structure appears to have been induced by a tidal interaction with NGC 4306. Such a tidal interaction would also explain its deficiency in neutral hydrogen gas (HI).
References
External links
4305
040030
Virgo (constellation)
Astronomical objects discovered in 1829
Dwarf spiral galaxies
07432
Virgo Supercluster
Interacting galaxies | NGC 4305 | [
"Astronomy"
] | 166 | [
"Virgo (constellation)",
"Constellations"
] |
61,479,719 | https://en.wikipedia.org/wiki/The%20Mammoth%20Dictionary%20of%20Symbols | The Mammoth Dictionary of Symbols is a reference work by Nadia Julien published by Robinson in 1996.
Contents
The Mammoth Dictionary of Symbols posits the two premises that symbols as a concept are now obsolete, and that symbols are actually material objects.
Reception
Tim Smith reviewed The Mammoth Dictionary of Symbols for Arcane magazine, rating it a 3 out of 10 overall. Smith comments that "Definitions such as: 'There is a tradition that says that swallows receive the souls of dead kings', or: 'Footwear is an indispensable item of dress in temperate regions', further undermine this as a reference work. That said, it could make a decent enough bog-read if only so you can fill in the gaps yourself."
References
1996 non-fiction books
Reference works
Symbols | The Mammoth Dictionary of Symbols | [
"Mathematics"
] | 157 | [
"Symbols"
] |
61,479,732 | https://en.wikipedia.org/wiki/C6H15O3P | {{DISPLAYTITLE:C6H15O3P}}
The molecular formula C6H15O3P (molar mass: 166.157 g/mol, exact mass: 166.0759 u) may refer to:
Diisopropylphosphite
Triethyl phosphite | C6H15O3P | [
"Chemistry"
] | 68 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,479,903 | https://en.wikipedia.org/wiki/C14H23NO2 | {{DISPLAYTITLE:C14H23NO2}}
The molecular formula C14H23NO2 (molar mass: 237.343 g/mol) may refer to:
2CE-5iPrO
2,5-Dimethoxy-4-isopropylamphetamine
2,5-Dimethoxy-4-propylamphetamine
Molecular formulas | C14H23NO2 | [
"Physics",
"Chemistry"
] | 84 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,481,280 | https://en.wikipedia.org/wiki/Pholiota%20squarrosoides | Pholiota squarrosoides is a species of mushroom in the family Strophariaceae. It is similar to the species Pholiota squarrosa. There are differing accounts on whether the mushroom is edible.
Description
This mushroom grows in crowded clusters, with caps up to in diameter and stems up to in length. The caps are convex at first, becoming flattened with age, and are sticky when wet. They are yellowish-brown with prominent cone-shaped, tawny scales which are crowded together near the centre. The gills are closely packed, yellow at first becoming rusty-brown later. The stem is the same colour as the cap and is covered with small scales. Near the top it bears a cottony yellowish ring which flares out. The spores are brown. It is difficult to distinguish this species from Pholiota squarrosa, but that mushroom has a greenish tinge to the gills and is never sticky.
Edibility
The species was reported as edible "with caution" by Kent and Vera McKnight, but that it can be confused with the poisonous P. squarrosa. Mycologist Alexander H. Smith wrote that it is the best edible species in its genus. Orson K. Miller Jr. and Roger Phillips regard it as edible, but a description provided by the University of Arkansas states that it is not.
Habitat
The species can commonly be found in late summer in the Great Lakes states, the Pacific Northwest, and eastern North America. Its habitat is on the bark of hardwood trees. It is rarely found in Europe, but the first specimen in Poland was discovered in 2010 in the southwestern part of the country. The Poland discovery happened at the Łężczok Nature Reserve near the town of Racibórz. The mushroom might also be found in the temperate regions of Asia. Although the mushroom is considered a saprophyte, rather than a parasite, it can cause the wood to degrade rapidly. In the Great Lakes region, it decays logs of the trees Acer saccharum and Tilia glabra.
References
Strophariaceae
Fungi of North America
Fungi of Europe
Fungus species | Pholiota squarrosoides | [
"Biology"
] | 435 | [
"Fungi",
"Fungus species"
] |
61,481,498 | https://en.wikipedia.org/wiki/Perspective%20geological%20correlation | Geological perspective correlation is a theory in geology describing geometrical regularities in the layering of sediments. Seventy percent of the Earth's surface are occupied by sedimentary basins – volumes consisted of sediments accumulated during million years, and alternated by long interruptions in sedimentation (hiatuses). The most noticeable feature of the rocks, which filled the basins, is layering (stratification). Stratigraphy is a part of Geology that investigates the phenomenon of layering. It describes the sequence of layers in the basin as consisted of stratigraphic units. Units are defined on the basis of their lithology and have no clear definition. Geological Perspective Correlation (GPC) is a theory that divided the geological cross-section in units according strong mathematical rule: all borders of layers in this unit obey the law of perspective geometry.
Sedimentation layers are mainly created in shallow waters of oceans, seas, and lakes. As new layers are deposited the old ones are sinking deeper due to the weight of accumulating sediments. The content of sedimentary layers (lithological and biological), their order in the sequence, and geometrical characteristics keep records of the history of the Earth, of past climate, sea-level and environment. Most knowledge about the sedimentary basins came from exploration drilling when searching for oil and gas. The essential feature of this information is that each layer is penetrated by the wells in a number of scattered locations. This raises the problem of identifying each layer in all wells – the geological correlation problem The identification is based on comparison of 1) physical and mineralogical characteristics of the particular layer (lithostratigraphy), or 2) petrified remnants in this layer (biostratigraphy). The similarity of layers is decreasing as the distance between the cross-sections increases that leads to ambiguity of the correlation scheme that indicates which layers penetrated at different locations belong to the same body (see A). To improve the results geologists take in consideration the spatial relations between layers, which restricted the number of acceptable correlations. The first restriction was formulated in XVII century: the sequence of layers is the same in any cross-section. The second one was discovered by Haites in 1963: In an undisturbed sequence of layers (strata) the thicknesses (H1 and H2) of any layer observed in two different locations obey the law of perspective geometry, i.e. the perspective ratio K = H1/H2 is the same for all layers in this succession. This theory attracted attention around the world., and particularly in Russia The theory is also a basis of the method of graphical correlation in biostratigraphy widely used in oil and coal industries.
Overview
The geometry is the main lead to natural resources exploration.For example, the oil geologists are looking for permeable layers of particular geometry, which allows keeping the oil in place (for instance, the domed shape anticlinal trap). The ore geologists are looking for faults in the sediments – the ways, which deliver the melted mantle materials to the upper crust. Knowledge about underground geometry of the sedimentary basins comes from geological observations, geophysical measurements and from drilling. Drilling gives the most detailed information about the position, thickness, physical, chemical and biological characteristics of each layer, but the point is that each well presents all this information in one location on the layer. Because the geometry of a layer can be very complicated it becomes a difficult problem and requires a significant number of drilled wells.
The challenge is identifying in each well the interval that belongs to the same layer now or in the past (see A). To do this geologists use all available characteristics of the layer. Only after this it is possible to begin the recovery of the geometry of the layer (to be more precise – the geometry of the top and bottom surfaces of the layer). This procedure is called geological correlation, and the results are presented as acorrelation scheme (A). It is natural that at the beginning of the exploration, when the number of wells is small, the correlation scheme contains expensive mistakes.
Basics of geological correlation
The Danish scientist Nicolas Steno (1638–1686) is credited with three principles of sedimentation
superposition: in undeformed stratigraphic sequences the oldest strata will be at the bottom of the succession,
original horizontality: layers of sediment are originally deposited horizontally,
lateral continuity: layers of sediments initially extend laterally in all directions.
The principles 1 allows defining the temporary relations between neighboring geological bodies, the principle 2 organizes the geometrical pattern of the succession of layers, the principle 3 helps uniting the parts of the layer found in separated geological cross-sections.
Practical correlation has a lot of difficulties: fuzzy borders of the layers, variations in composition and structure of the rocks in the layer, unconformities in the sequence of layers, etc. This is why errors in correlation schemes are not seldom. When the distances between available cross-sections are decreasing (for example, by drilling new wells) the quality of correlation is improving, but meanwhile the wrong geological decisions could be made that increases the expenses of geological projects. From Steno's principle of initial horizontality follows that the top borders of the layers (tops) were initially flat, and remained flat until the complete succession stays undisturbed by subsequent tectonic movements, but no regularities about the geometric relations between these flat surfaces in the succession were known. The first to shed light on the problem was Canadian geologist Binner Heites: in 1963 he published the Geological Perspective Correlation hypothesis. Perspective geological correlation is a theory that establishes strong geometrical restrictions on the geometry of the layers in sedimentary deposits.
Perspective geometry in undisturbed succession of layers
In 1963 the Canadian geologist Binner Heites discovered a strong regularity of the layering in sedimentary basins: the thicknesses of layers within each stratigraphic unit are governed by the law of perspective correspondence. It means that in undisturbed succession on the correlation scheme the straight lines drawn through the border points of the same layer in two cross-sections intersect in one point – center of perspectivity (see B).
For geological purposes more convenient geometrical presentation of perspective relations is the correlation plot proposed by Jekhowsky (see C): the depths of the layer's borders in one geologic cross-section are plotted along axis h′ (h1′, h2′, h3′,...), and the position of the same layers in another cross-section are plotted along axis h′′ (h1′′, h2′′, h3′′, ...). Points 1, 2, 3 ... with coordinates (h1′, h1′′), (h2′, h2′′), and (h3′, h3′′), accordingly, are called correlation points, and a curve drawn through these points, a correlation line. Black dots (connectors) represent the relative position of correlated borders on the plot. When the layers geometry satisfies the conditions of perspective correspondence the correlation line is a straight line. In the particular case of parallel layers the inclination of the correlation line is 450.
The Perspective Geological Correlation also states that
each sedimentary basin consists of a number of stratigraphic units (sequence of layers without unconformities), and
in each unit the relations between the thicknesses of the layers in two cross-sections satisfy the perspective geometry conditions with individual ratios K.
Heites also concludes that all strata in each unit were governed by the same rate of deposition, and their borders are synchronous time-planes. Each layer has different thicknesses in different locations, but they lasted equally long. It was a significant input in chronostratigraphy.
The following are consequences of the basic statements:
In different stratigraphic horizons the slopes of the correlation lines are different.
If two adjacent sections have the same slope then both sections belong to the same stratigraphic horizon. The gap between the lines indicates a fault.
If on the correlation line that presents the undisturbed stratigraphic succession one correlation point doesn't fit the line it means thata) the correlation of the tops of the corresponding layer is wrong, or b) lithologic replacement.
Connections to traditional lithostratigraphy
The Perspective Geological Correlation is well grounded in traditional geology. The method of convergence maps serves for determining the structure of the layer based on the known structure of the layers lying above. It is based on the assumption that the layers are close to parallel. Convergence map shows lines of equal distance (isopach lines) between key layer and target layer. If the layers are parallel the distance between these layers is constant, the structures of both layers are identical, and to determine depths of the target horizon it is enough to get only one deep well, which reached the target layer. But in reality such conditions are extremely rare. In reality restoring the geometry of the target horizon demands a number of deep wells in the area. In this case the standard procedure for calculating the distance between the target layer and key layer in any point in the area is linear interpolation between the known wells. The reliability of the result (the geometrical structure of the target horizon) is estimated by the analysis of the trend of the distances between key horizon and target horizon (isopachs): if the trend is regular, for example, the distances are monotonically changing in one direction, it is a sign of reliability of the reconstruction. In the simplest case the surface of the target horizon is a plain in general position, and the linear interpolation gives the correct result. The assumptions of the convergence method are consequences of the perspective correlations theory, so, the method obtains the theoretical background. The theory also gave an additional criteria for the validity of the reconstructed surface. It defines the stratigraphic interval where layers were deposited without interruption, and where the layers' thicknesses satisfy the law of perspective geometry.The convergence maps deliver the correct result only when the layers belong to such stratigraphic unit.
Testing
The description of the theory was supplied by a number of cases in support of the theory.
The plot (D) shows the correlation plot for two wells in Alberta (Canada): Innisfail 15-8-35-1W5 and Innisfail 7-33-25-lW5 . The cross-section of Innisfail field contains a middle Proterozoic to Paleocene sedimentary succession in excess of 6 km in thickness. The graph shows that the relations between thicknesses of all corresponding layers in these two cross-sections are located on the straight line, i.e. submit to the law of geometrical perspective with the same perspective ratio K. The markers are from conventional correlation scheme.The deviation of the correlation points from the straight line is about 5 feet on average. .
The plot (E) demonstrates that Perspective Geological Correlation works at long distances as well. The plot shows the correlation between two wells in Canada 300 miles apart (Saskatchewan and Manitoba) in Silur-Ordovician carbonates (the tilt angle 530 corresponds to K = 1.6).
The first review of Heites' publication appeared at 1964 in Russia. It describes in the details the hypothesis and estimates very high its potential. The idea attracted the programmers working on automation of correlation on computers: the known rules of correlation were fuzzy, and it was impossible to formalize them and transform them into algorithms. The restrictions of the geometry of layering observed by Heites allowed compensating the lack of nonformal human knowledge.
A group of Russian scientists (Guberman, Ovchinnikova, Maximov) positively tested Heites' hypothesis in different oil-bearing province using the computer program (in Central Asia, Volga-Ural province, West and East Siberia, and Russian Platform). For example, see plot (F). The activity of this group continued in 2000th, and covers new geological provinces around the globe Canada, Kansas, Louisiana, South Welsh. O. Karpenko demonstrated an effective use of perspective correlation in resolving very practical problems of oil exploration. The law of perspective accordance allowed to discover the boundaries of changing the paleotectonic regime in the thin-layered sedimentary rocks, while the regular correlation technic didn't work. At the example of Rubanivsk gas field author demonstrated that the Dashava deposits of Precarpathian External Zone depression can be divided into number of zones of stable sediment accumulation in different conditions. Some zones correlate with the intervals of enhanced gas flow rate.
These works show that
the hypothesis is correct in the wide variety of geological conditions,
it works at long distances,
it can serve as a solid test for stratigraphic schemes made by geologists,
it reviles the unconformity of layers as small as 1° (G–I), and faults with the amplitude of displacement as small as 1–2 m (G–II),
the number of correctly correlated tops in the stratigraphic unit without unconformities has to be not less than three, and as bigger is this number the bigger is the reliability of the result,
it is an instrument for correcting the mistakes.
Since the publication of Heites' theory in 1963 it was republished in a number of reviews on quantitative methods of correlation (including automatic correlation). Some of the reports (Hansen, Salin, Barinova) demonstrate that the perspective correlation allowed to achieve better reconstruction of the geological structure at the early stages of geological exploration. Hansen describes the controversial history of investigating the complicated Patapsco formation in Maryland and Virginia (USA), and claims that “an adaptation of Heites' (1963) technique of perspective correlation is used to subdivide the Patapsco Formation into consistently defied mapping units”. Salin was able to simplify the stratigraphic description of Khatyr depression (Siberia) by applying perspective correlation. Barinova analysed the structure of Osipovichy gas underground storage (East Europe)) by automatic correlation program baswed on Haites principles. Because of the high resolving power of the method it was recognized the existence of a number of geological faults that break the leakproofness. Because of small displacements of the faults they were not found by the traditional methods of correlation, and rejected by the geological service of the project. Very soon after the storage started functioning significant leakage of gas was recognized
Extension to biostratigraphy
In 1964 Shaw proposed the method of correlating fossiliferous stratigraphic profiles using the two-axis graph (H). The markers on each axis are the observed depths of lowest (FAD) and highest (LAD) occurrences of a specially defined group of fossils (taxa). The appearances/ disappearances of taxa are regarded as synchronous and used as markers of correlation. When projected on a graph, the corresponding points of two compared profiles form the Line of Correlation (LOC). Shaw showed that the ideal LOC consists of linear segments (H). Such conditions occur when the number of collected fossils is big, and one can be sure that the material covers the complete range of fossils appearance, and FADs and LADs can be accurately determined. In the reality, some sampled ranges will be shorter than true ranges, and this can disturb the linearity of the LOC.
In every stratigraphic interval correlated ends of the range (FAD or LAD) belong to the same time surface, and in each geological cross-section (well or outcrop) this interval has identical duration but different thickness. It means that accumulation rates (thickness-to-duration ratio = tg β) are different in different locations. From the fact that the relation of durations of the units and their thicknesses are linear follows that in the limits of the linear section of LOC all strata have the same accumulation rate.
The reliability and accuracy of Shaw's method have been tested by Edwards, using a computer simulation on hypothetical data sets, and by Rubel and Pak in terms of the formal logic and stochastic theory.
The graphical correlation became a very important tool of stratigraphy in coal and oil industries.
In 1988 Nemec showed the equivalence of Haites' perspective correlation, and Shaw's graphical correlation
Sedimentation model
Based on the theory of perspective correlation in 1986 S. Guberman proposed a model of the process of sedimentation According Haites’ theory in the given sedimentary basin in each stratigraphic unit the condition of perspective correspondence are satisfied in any pair of wells. From this follows that the tops and bases of the layers in this stratigraphic unit satisfy the conditions of perspective correspondence in 3-D space (K). Any three points of a plane define the complete plane. It means that if in three wells the thicknesses of layers belonging to the same stratigraphic unit are known, then the thicknesses of these layers can be calculated for any location in the basin. Accordingly, if the structure of the top border of the stratigraphic unit is known, the structure of any other border in this unit can be calculated.
The model of creating such sophisticated geometrical pattern is based on the first Steno's principle: the strata are originally horizontal, i.e. are planes. It occurs in the shallow waters due to the turbulence of the undersurface layer of water. The second Steno's principle, which indicates the creation of a series of sedimentary layers lying on top of each others, supposes the subsidence of the basin. The sinking of the basin follows the strong geometrical restrictions: the tectonic bloc, which carry the basin, is rotating around the straight line parallel to the water surface, and located onshore (L). As a result, until the moment of main tectonic disturbance all borders of the layers remain flat and the geometrical inter-relations are described as perspective correspondence. In the future the tectonic movements will distort the shape of the layers – the borders will no more be planes, but in majority of cases the changes are smooth and the perspective relations are maintained.
This model allows specifying some geological terms. The Steno's horizontality principle has to state: the top surface of the sediments is horizontal.The conformity is a fundamental notion in stratigraphy. Until now this term is used in two different meanings: a surface between two stratigraphic sequances, and the relationship between two stratigraphic units. Sometimes both were used in the same paragraph (see, page 84).Perspective correlation principle allows to define the notion of conformity: sequence of layers that obey the conditions of geometrical perspective is a unit of conformity. Two neighboring units of conformity are in relation of unconformity.
Here is an example that shows that the borders of undisturbed stratigraphic unit in the Middle Carboniferous (Volga-Ural oil province, Russia) initially were plains. In the central part of the area (about 100 km in diameter) were chosen three wells at distances of 10 – 15 km.. The three tops of the stratigraphic unit in the three wells are points in 3D space with coordinates x, y, z, where x and y are present the position of the well on the surface (M), and z is the thickness of the stratigraphic unit in this location. They determine the top plain of the unit as it was at the time of its creation. The three bases determine the bottom plane of the unit at it was at the same time. This allowed calculating the thickness of the stratigraphic unit at any point in the area. Because the area was well enough drilled the calculated numbers can be compared with the real numbers. The average difference equals 2%.
References
Geology
Stratigraphy
Sediments
Sedimentary basins
Geometry | Perspective geological correlation | [
"Mathematics"
] | 4,063 | [
"Geometry"
] |
61,481,971 | https://en.wikipedia.org/wiki/C2H10B2 | {{DISPLAYTITLE:C2H10B2}}
The molecular formula C2H10B2 (molar mass: 55.72 g/mol, exact mass: 56.0969 u) may refer to:
1,1-Dimethyldiborane
1,2-Dimethyldiborane | C2H10B2 | [
"Chemistry"
] | 70 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,482,165 | https://en.wikipedia.org/wiki/C34H24N6Na4O16S4 | {{DISPLAYTITLE:C34H24N6Na4O16S4}}
The molecular formula C34H24N6Na4O16S4 (molar mass: 992.80 g/mol, exact mass: 991.9723 u) may refer to:
Direct Blue 1
Direct Blue 15 | C34H24N6Na4O16S4 | [
"Chemistry"
] | 71 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
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