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72,678,994 | https://en.wikipedia.org/wiki/Chung%20K.%20Law | Chung King Law (;born 31 August 1947;also known as Ed Law) is a Chinese-born American scientist and a Robert H. Goddard professor at Princeton University. He is a specialist in the combustion science.
Career and research
Law received his bachelors and masters degree, respectively from University of Alberta and University of Toronto. He completed his PhD in 1973 under the supervision of Forman A. Williams at University of California San Diego. He worked at the General Motors Research Laboratories for two years and briefly at the Princeton University before joining the faculty at the Northwestern University in 1976. He joined the faculty of University of California Davis in 1984 and left in 1988, to join the faculty at Princeton University, where he is currently the Robert H. Goddard professor.
Law has made several contributions to the combustion field, especially, in connection with droplet dynamics and burning, laminar flame speed and stretched flames, chemical mechanism reduction.
Books
Honors and awards
Law holds many honors and awards. He is an elected fellow of ASME (1989), AIAA (1992), APS (2006), the American Academy of Arts and Sciences (2010), the American Association for the Advancement of Science (2012), Combustion Institute (2018). He is an elected member of the US National Academy of Engineering (2002). He is a past president of the Combustion Institute (2000-2004).
Silver Combustion Medal (1990) from The Combustion Institute
Alfred C. Egerton Gold Medal (2006) from The Combustion Institute
Pendray Aerospace Literature Award (2004) from AIAA
The journal Combustion and Flame issued a special issue commemorating Law's 70th birthday in 2018.
References
External links
1947 births
University of Toronto alumni
Fluid dynamicists
Living people
University of California, San Diego alumni
Fellows of the Combustion Institute
Fellows of the American Physical Society
University of Alberta alumni | Chung K. Law | [
"Chemistry"
] | 372 | [
"Fellows of the Combustion Institute",
"Combustion",
"Fluid dynamicists",
"Fluid dynamics"
] |
72,679,277 | https://en.wikipedia.org/wiki/Amanita%20orientigemmata | Amanita orientigemmata, is a species of agaric fungus in the family Amanitaceae native to northeastern, northwestern and southern China, India and Japan, first described by Zhu L. Yang & Yoshimichi Doi in 1999.
Description
It is characterized by its yellowish to yellow pileus with white or dirty-white volval remnants that are felted to patchy, sometimes pyramidal. Its annulus is fragile and fugacious; sometimes volval remnants remain on the stipe base. Basidiospores are broadly ellipsoid, clamps exist as well. It has been involved in at least one non-lethal case of psycho-neurological poisoning in China.
References
External links
orientigemmata
Fungi of Asia
Fungi described in 1999
Fungus species | Amanita orientigemmata | [
"Biology"
] | 161 | [
"Fungi",
"Fungus species"
] |
72,679,381 | https://en.wikipedia.org/wiki/Amanita%20viscidolutea | Amanita viscidolutea is a species of agaric fungus in the family Amanitaceae native to Brazil.
Taxonomy
The species was first described by Menolli, Capelari & Baseia in 2009.
Description
Amanita viscidolutea has a yellow pileus of in diameter, plane to depressed, with distinct striate white margin and yellowish-white patches of universal veil at center. Lamellae are free, yellowish-white, truncate to rounded-truncate. The stipe is tall and about wide, yellowish-white and exannulate, with bulb-shaped remnants of universal veil encircling stipe base. It has a pleasant aroma. Basidiospores are inamyloid.
Distribution and habitat
Native to Brazil, this species is solitary to subgregarious, and grows in sandy soil. It is associated and thus possibly in mycorrhizal symbiosis with Coccoloba and Guapira species.
Conservation
It is listed as a vulnerable species on IUCN Red List. Given its habitat, it is threatened by deforestation.
References
viscidolutea
Fungi of Brazil
Fungi described in 2009
Fungus species | Amanita viscidolutea | [
"Biology"
] | 247 | [
"Fungi",
"Fungus species"
] |
72,679,468 | https://en.wikipedia.org/wiki/Amanita%20rimosa | Amanita rimosa is a species of agaric fungus in the family Amanitaceae native to Hunan, first described by P. Zhang & Zhu L. Yang in 2010. Like other Phalloideae amanitas, it is lethally toxic. A distinctive feature of A. rimosa is its rimose pileus, caused by slightly gelatinized upper layer of the pileipellis, which is a rare structure among other Amanita species.
Ingestion can result in fatal liver damage due to amatoxins.
External links
References
rimosa
Fungi of Asia
Fungi described in 2010
Deadly fungi
Fungus species | Amanita rimosa | [
"Biology"
] | 130 | [
"Fungi",
"Fungus species"
] |
72,681,937 | https://en.wikipedia.org/wiki/Amira%20Abdelrasoul | Amira Abdelrasoul is a researcher and associate professor at the Department of Chemical and Biological Engineering at the University of Saskatchewan, where she is the principal investigator of the Hemodialysis Membrane Science and Nanotechnology Research Centre. She is also a membrane technology leader in Canada, and her interdisciplinary research program focuses on solving existing hemodialysis system problems.
Early years and education
Amira Abdelrasoul received her Bachelor of Science in Chemical Engineering from Alexandria University, Egypt. She then completed a Master of Science from Kuwait University, Kuwait, and went on to receive her PhD from Ryerson University (currently Toronto Metropolitan University), Canada, where she completed postdoctoral research. She is also a licensed professional engineer at Professional Engineers of Ontario (PEO) and Association of Professional Engineers and Geoscientists of Saskatchewan (APEGS).
Career
Abdelrasoul started her career as a research assistant at the American Engineering Consultants ARAMCO in 2000. She joined Kuwait Polyurethane Industry as a R&D polymer process engineer in 2002. Later, she served as a research and teaching assistant at the Department of Chemical Engineering at the College of Engineering and Petroleum, Kuwait, from 2005 to 2008. During this time, she joined Kuwait Institute for Scientific Research as a research assistant in 2006. In 2008, she started working as a product development engineer at J Composites Inc, Canada.
Abdelrasoul became a teaching assistant at Ryerson University in 2011 while simultaneously pursuing a PhD. In 2015, she got promoted to the position of lecturer at the Department of Chemical Engineering at Ryerson, where she was also a postdoctoral research associate.
In 2017, Abdelrasoul joined the University of Saskatchewan's chemical and biological engineering department as an assistant professor and was promoted to associate professor in July 2022. She is the principal investigator of the Hemodialysis Membrane Science and Nanotechnology Research Centre at the University of Saskatchewan.
In 2019, she was an early career investigator in the Canadian Institutes of Health Research (CIHR) Peer Review Committee for the Project Grant Competition. In 2020, Abdelrasoul co-chaired the Exploration Multidisciplinary Review Panel of New Frontiers in Research Fund (NFRF) of Social Sciences and Humanities Research Council.
Abdelrasoul is also an associate member of numerous educational and research institutes, including the Biomedical Engineering Division at University of Saskatchewan, Global Institute for Water Security at the University of Saskatchewan, Gwenna Moss Centre for Teaching and Learning at the University of Saskatchewan, Yeates School of Graduate Studies at the Toronto Metropolitan University, and the Kidney Health and Disease (M3K) Committee. In addition she is a member of M3K Organizing Committee for the second pan-Canadian Molecules and Mechanisms Mediating Kidney Health and Disease (M3K) Meeting in Montreal, Canada in 2023.
Since 2018, Abdelrasoul has been a part of the Membrane Technology Design Projects Client at the University of Toronto for Engineering Strategies and Practice Course (ESP) APS112 and APS113. She joined Scientific Reports as an editorial board member in 2022.
Abdelrasoul also achieved a teaching portfolio with a University Teaching Development Professional Program (UTDP) accredited by SEDA (Staff and Educational Development Association) in the United Kingdom. She is a licensed Instructional Skills and Educational Development Facilitator and a Fellow of the Staff and Educational Development Association (FSEDA).
She has launched the Women in Engineering (WIE) chapter in the Chemical and Biological Engineering Department at the University of Saskatchewan, and she has been the WIE chair since 2018 to support and lead WIE undergraduate and graduate students; to support equity, diversity, and inclusion; and to mentor female student to build skills and reach crucial milestones.
Hemodialysis membrane research
At University of Saskatchewan, Abdelrasoul initiated and incepted the first hemodialysis membrane research program in Canada. Her interdisciplinary research program focuses on solving existing hemodialysis problems, decreasing morbidity and mortality rates of hemodialysis patients, increasing the quality of life of kidney failure patients, and decreasing the high costs to the healthcare system in Canada and beyond that are normally attributed to hemodialysis and its shortcomings. Abdelrasoul was on the top list of the first NFRF competition of 2018 exploration for her interdisciplinary, international, high-risk/high-reward and fast-breaking research funded by the Social Sciences and Humanities Research Council.
Abdelrasoul has pioneered the use of customized gold nanoparticles to label and track the movement of specific blood proteins through hemodialysis membranes, which has proven to be a significant advance towards achieving more biocompatible dialysis membranes. The work she has done has led to groundbreaking advances in hemodialysis membrane science and technology. For example, one recent study was the first to be able to predict the inflammation that patients may experience after a dialysis session. With the new information she has gathered through her work at CLS, she is now able to create new designs and membrane materials to be tested in dialysis applications. Abdelrasoul's research program progress was featured in The Conversation Canada in April 2022. She has been interviewed by CTV Your Morning and CTV News. In 2022, she was invited to deliver a lecture on the life/ nephrology campus in Germany.
She is an active member of the Saskatchewan Centre for Patient-Oriented Research (SCPOR). She is working with dialysis patients and conducting targeted knowledge mobilization initiatives to facilitate sharing of the findings of her research program in non-academic mediums and with stakeholders. This work is partially funded by the Saskatchewan Health Research Foundation (SHRF) to further develop research directions toward patient outcomes.
Her team was the first in Canada to conduct in-depth studies of the chemical and physical characteristics of hemodialysis membranes used in Canadian hospitals. Her team also worked on modeling membrane characteristics and clinical practices to predict inflammation in dialysis patients. This work is now expanding to consider how different membranes and practices affect patients of different sexes, genders, and races, and with different medical histories. Abdelrasoul is working on synthesizing new and improved hemodialysis membranes. This direction will lead to new membranes that are more compatible with patient blood, and thus will enhance their quality of life and address a critical health and economic problem in Canada.
Her team has developed a theoretical model using computer simulations of molecule interactions to gain insight the interaction between blood proteins and the HD membranes currently used in hospitals. Abdelrasoul's recent work at the CLS has led to groundbreaking advances in HD membrane science and technology. For the first time, her research has directly linked the characteristics of the commercial membranes used in Canada to patient side effects.
App for dialysis patients
Abdelrasoul worked with Push Interactions and funding from the Saskatchewan Health Research Foundation to develop an app through which dialysis patients can share their experiences.
Publications
Articles
Abdelrasoul has authored and co-authored numerous research articles.
Books
She authored Biomimetic and Bioinspired Membranes for New Frontiers in Sustainable Water Treatment Technology Book (2017). She is also the editor of Advances in Membrane Technologies (2020).
Honours and awards
Abdelrasoul received multiple academic excellence awards throughout her academic journey from Alexandria University, Kuwait University, and Ryerson University for her academic achievements. Abdelrasoul received the Governor General's Academic Gold Medal in 2015, the most prestigious academic award in Canada, for achieving the highest academic standing in her PhD degree program. She was also granted multiple scholarships due to her outstanding academic record, including Queen Elizabeth QEII GSST, Ryerson Graduate Scholarship, and Ontario Graduate Scholarship twice.
Abdelrasoul received the Best Poster Presentation Award at the Membrane Technology Conference, Orlando, USA, in 2015. She was a recipient of the Norman Esch Engineering Innovation and Entrepreneurship Award twice in 2015 and 2016 for pitching innovative membranes for engineering entrepreneurship startups. She was awarded C. Ravi Ravindran Outstanding Doctoral Thesis Award by Ryerson University in 2015 for her doctoral dissertation. This award recognizes the excellence of the doctoral dissertation from the points of originality, contribution to better understanding of the theory, philosophy, science, practice interrelationship, application of theory and impact on society, industry and environment.
In 2019, she was nominated for the Young Investigator Award by the Journal of Membranes and the Canadian Journal of Chemical Engineering Lectureship Award by the Canadian Society for Chemical Engineering (CSChE). Abdelrasoul was a recipient of the Good Fellow Faculty Travel Award from the University of Saskatchewan in 2019.
Later in 2021, she was nominated for Emerging Star in Chemical Engineering Research and Design Journal. She was also nominated for the Best Supervisor Award twice in 2021 and 2022 and received Best Clinical Paper Award at Life and Health Sciences Research Expo held at the University of Saskatchewan in 2021.
In 2021, Abdelrasoul received Dean's Remote Teaching recognition for her excellence in teaching in the College of Engineering at the University of Saskatchewan. She was named an Outstanding Women Researcher in Chemical Engineering by the Journal of Chemical Engineering Research and Design in 2022. She has also received the Young Investigator Excellence Award by the Canadian Light Source (CLS) Synchrotron, 2022.
Selected media
2023: Global News with Jeffrey Meskens- Saskatoon-developed app connects dialysis patients to experts and others
2023: Global News – University of Saskatchewan Research team developing breakthrough membrane renal material
2023: Usask News- Groundbreaking USask research identifies key blood protein target for improving dialysis
2023: Global News with Jeffrey Meskens – USask research could make kidney dialysis a lot more comfortable for patients
2023: TEDx – Wearable Kidney: Revolutionizing Kidney Failure
2023: CJWW Radio- Another step closer to more effective dialysis for kidney patients
2022: CTV Your Morning Live with Anne-Marie Mediwake – 'We are getting closer': Canadian research team develops tool to minimize dialysis complications
2022: Actualites Canada- Une Équipe De Recherche De La Saskatchewan Vise À Réduire Les Complications De La Dialyse
2022: USask News-Abdelrasoul honoured with two research awards
2022: Education News Canada- Abdelrasoul honoured with two research awards
2022: The Conversation Canada- Hemodialysis: New research could vastly improve this life-sustaining treatment for kidney failure patients
2022: Medical Express-New research could vastly improve hemodialysis,
2022: National Post – Hemodialysis: New research could vastly improve this life-sustaining treatment for kidney failure patients
2022: Phys.Org-A new coating to protect kidney failure patients on dialysis
2022: SaskToday-Synchrotron research focus on reducing dialysis side effects
2022: Global News TV- Abdelrasoul was interviewed by Emily Simmonds, Global News TV
2022: CLS News – Scientists develop new coating to protect kidney failure patients on dialysis
2021: CTV Morning Live with Mike Ciona – Live interview with Amira Abdelrasoul
2021: Saskatchewan Health Research Foundation-Meet the Researcher - Dr. Amira Abdelrasoul, University of Saskatchewan
2021: Pattison Media- Abdelasoul was interviewed by Alice McFarlane, Pattison Media
2021: SaskToday – Dairy discovery could improve dialysis design for kidney failure patients
2021: CLS News – Dairy discovery could improve dialysis design for kidney failure patients
2019: CTV Saskatoon Live- U of S team working on artificial, wearable kidney
2019: Saskatoon StarPhoenix – U of S research team aims to develop world's first wearable kidney
2019: EurekAlert – World's first wearable kidney goal of USask-led research team
2019: Battlefords News-Optimist – World's first wearable kidney the goal of USask-led research team
2019: Toronto Sun- Research team aims to develop world's first wearable kidney
2019: USask News – World's first wearable kidney the goal of USask-led research team
2019: Medical Magazin -Wearables: World's first wearable kidney
2017: Ryerson News- An innovative portable water solution
2016: Ryerson News- Inspirational faculty meets innovative research
References
Canadian women chemists
Canadian chemical engineers
Women chemical engineers
Living people
Year of birth missing (living people)
Alexandria University alumni | Amira Abdelrasoul | [
"Chemistry"
] | 2,562 | [
"Women chemical engineers",
"Chemical engineers"
] |
72,682,245 | https://en.wikipedia.org/wiki/Harvester%20%28HCI%29 | Harvester is a cloud native hyper-converged infrastructure (HCI) open source software. Harvester was announced in 2020 by SUSE.
On 1 December 2020, SUSE acquired Rancher Labs who makes a product called Rancher that manages kubernetes clusters. As of v0.3.0 rancher supports integration with harvester to provide a "single pane of glass" (central web GUI) to manage both your infrastructure and workloads.
Harvester Overview
Architecture
Bare Metal
Harvester is a type 1 hypervisor designed to be deployed on bare metal servers. It can be manually installed using a ISO disk or USB install, or installed over the network via a PXE Boot server such as IPXE.
OS
Harvester uses the Elemental Toolkit to create a minimal cloud-init version of SUSE Linux Enterprise Micro 5.3 to provide an immutable Linux distribution to remove as much OS maintenance as possible.
Virtualization
Kubevirt is used on top of kubernetes to provide virtualization support. This allows harvester to run virtual machines as a kubernetes workload. Harvester provides most basic features provided by other hypervisors such as ESXi, Proxmox VE and XCP-NG / Citrix XenServer. As of v1.1.0 PCI Device passing is supported as an experimental feature, allowing PCI devices on the hypervisor host to be passed directly to a VM. Devices not in use directly by the hypervisor can be used. This is useful for passing a GPU for GPU-Accelerated Computing or NVMe storage for IOPS sensitive use cases like databases.
See also
Dell EMC VxRail
Cisco HyperFlex
VMware
Rancher Labs
References
External links
Hyper-converged infrastructures
Free software programmed in Go
Linux software
Software using the Apache license | Harvester (HCI) | [
"Technology"
] | 387 | [
"Hyper-converged infrastructures",
"IT infrastructure"
] |
72,683,201 | https://en.wikipedia.org/wiki/Ralucca%20Gera | Ralucca Michelle Gera (née Muntean) is an American mathematician specializing in graph theory, including graph coloring, dominating sets, and spectral graph theory. Her interests also include personalized learning in mathematics education. She is a professor of mathematics at the Naval Postgraduate School.
Education and career
Gera was an undergraduate at Western Michigan University, graduating Phi Beta Kappa and with honors in mathematics in 1999. She remained at Western Michigan University for her doctoral studies, completing a PhD in 2005 under the supervision of Ping Zhang; her dissertation was Stratification and Domination in Graphs and Digraphs.
She has been a faculty member at the Naval Postgraduate School since 2005, and became a full professor there in 2018. She served as Associate Provost For Graduate Education from 2018 to 2021, and at the same time served as the founding director of the Teaching and Learning Commons at the Naval Postgraduate School
Recognition
In 2016, the Naval Postgraduate School gave Gera their Richard W. Hamming Excellence in Teaching Award.
References
External links
Home page
Year of birth missing (living people)
Living people
American mathematicians
American women mathematicians
Graph theorists
American mathematics educators
Western Michigan University alumni
Naval Postgraduate School faculty | Ralucca Gera | [
"Mathematics"
] | 233 | [
"Mathematical relations",
"Graph theory",
"Graph theorists"
] |
72,683,214 | https://en.wikipedia.org/wiki/Oppidum%20of%20Moulay | Excavations took place at the oppidum de Moulay or oppidum du Mesnil, an oppidum in the commune of Moulay in the Mayenne in the Pays de la Loire region between 1972 and 1975, when the commune was subdivided. The excavation of the first rampart uncovered suggestions an area of 12 hectares, as well as a number of artifacts now exhibited at the Musée archéologique départemental de Jublains. On 26 May 1986, the site was declared a .
In 2004, road construction in Moulay and Mayenne uncovered a second rampart 1,200 meters long. The total area of the enclosure is 135 hectares, making it one of the ten largest oppida in France and the largest on the Armorican Massif. An 11-hectare excavation ended in June 2011.
Location
The location of Moulay favored settlement there. At the confluence of the Mayenne and the Aron rivers, whose rugged valleys outline a trapezoid, it apparently guarded access to a ford over the Mayenne.
First excavations
The site has long been known as "Camp de César", (Caesar's Camp), even though a preliminary excavation between 1972 and 1975 determined that its origins were Gaulish. It also brought to light a murus gallicus type defensive wall surrounding an area of twelve hectares.
First rampart
The first rampart, 370 m long, initially was six meters high and 20 meters wide, preceded by a ditch. To the north, a postern gate with a dry stone wall three meters thick overlooks the site.
Inside the first wall
Excavations inside the first wall found little beyond hearths and a few sparse items. Some of these were linked to bronze handicrafts: molds for bracelets and lapilli. Also, a lovely pottery vase decorated with cordons was discovered, of a type known in Armorica, and whose clay came from present-day Lamballe. Apart from the furniture, dated to the end of the Gaulish era, wattle and daub elements have been found.
More than 200 grindstones were discovered 800 meters from the first enclosure, dating from the late La Tène period.
Discovery of the second enclosure
A diagnostic excavation in 2004 prior to the construction of a detour identified a second rampart 1,000 m from the first, also known as the rempart du Petit Mesnil, a murus gallicus, 2.50 m high. The estimated footprint of the oppidum was revised upward to 135 hectares, and the site seemed related to the barred spur type, with multiple bars.
Excavation
A team of 29 archeologists took over. The archeological work at the oppidum was to finish up in mid-2011 then for another eight months excavate two farms.
The second phase of the excavations st this site was authorized and funded in part through the framework of the French 2008-2009 economic stimulus plan.
Excavations
The oppidum was no doubt the capital of the Aulerques Diablintes in the 1
first and second century BCE. Besides the oppodium wall, two Gaulish farms have been identified, one in Moulay, the other in Aron. Preliminary results of excavation indicate but do not quite prove the hypothesis of a densely occupied space, of 80 hectares or possibly even larger,
The oppidum is organised orthogonally into residential neighborhoods and artisanal and religious land uses. The residential enclosures mostly consist of a house and a storehouse, and are delimited by ditches. An artisanal and commercial quarter occupied the centre of the oppidum enclosure.
Water supply points and a sewer network have been uncovered. The space between the first and second walls may have been caused by an expansion of the settlement in the 1st century BCE. No trace of destruction, violence or sudden abandonment explains the depopulation of this site, in the centre of a territory as large as a modern département, surrounded by secondary centers such as Entrammes and Jublains.
Interpretation
The dating and function of the first enclosure are difficult to understand, particularly with respect to its relationship to the second; perhaps a matter for future research.
The site was abandoned in the Roman era in favor of Jublains; there is no evidence of violence or a fire. The site was developed in a planned manner, which implies a local élite. Moulay constitutes the largest fortified settlement in the area, according to E. Le Goff. Surrounded by secondary centers, among which may have been Jublains, Moulay also seemed to Le Goff to have been the heart of a powerful political system.
Notes and references
Oppida
Gallo-Roman culture
Excavations
History of Mayenne
Fortifications
Military camps
Roman Gaul
Prehistoric France
Archaeology of France
Armorica
Roman roads in Gaul | Oppidum of Moulay | [
"Engineering"
] | 978 | [
"Fortifications",
"Military engineering"
] |
72,683,786 | https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%20problem | The Earth–Moon problem is an unsolved problem on graph coloring in mathematics. It is an extension of the planar map coloring problem (solved by the four color theorem), and was posed by Gerhard Ringel in 1959. An intuitive form of the problem asks how many colors are needed to color political maps of the Earth and Moon, in a hypothetical future where each Earth country has a Moon colony which must be given the same color. In mathematical terms, it seeks the chromatic number of biplanar graphs. It is known that this number is at least 9 and at most 12.
The Earth–Moon problem has been extended to analogous problems of coloring maps on any number of planets. For this extension the lower bounds and upper bounds on the number of colors are closer, within two of each other. One real-world application of the Earth–Moon problem involves testing printed circuit boards.
Formulation and history
In the map coloring problem, finitely many simply connected regions in the Euclidean plane or a topologically equivalent space, such as countries on the surface of the Earth, are to be colored so that, when two regions share a boundary of nonzero length, they have different colors. It can be transformed into a graph coloring problem by making a vertex for each region and an edge for each two neighboring regions, producing a planar graph whose vertices are to be colored. Corresponding to the requirement that adjacent regions should have different colors, adjacent vertices (the two endpoints of any edge) should have different colors. According to the four color theorem, the resulting planar graph (or any planar graph) can be colored using at most four different colors, no matter how many regions are given.
In 1959, Gerhard Ringel published a book on colorings of surfaces, surveying the results at the time on the four color problem and the Heawood conjecture on coloring maps on non-planar surfaces such as the torus and Klein bottle. Both had been long-conjectured but were unsolved at the time. Ringel himself later proved the Heawood conjecture in a 1968 paper with J. W. T. Youngs; the four-color theorem evaded proof until 1976. Another topic of Ringel's book was a result of Percy John Heawood from 1890, on the "empire problem": coloring maps in which each empire has some number of distinct regions on the Earth (a home country and colonies). As Heawood showed for , and Ringel later proved with Jackson in 1984 for , colors are necessary and sufficient. Perhaps inspired by this problem and the dawn of the space age, Ringel included the Earth-Moon problem in his book as a variant of the empire problem in which the colonies are on the Moon rather than on the Earth. In a formulation of Martin Gardner, the colonies are instead on Mars.
In Ringel's Earth–Moon problem, each country on the Earth has a corresponding colony on the surface of the Moon, that must be given the same color. These colonies may have borders that are completely different from the arrangement of the borders on the Earth. The countries must be colored, using the same color for each country and its colony, so that when two countries share a border either on the Earth or on the Moon they are given different colors. Ringel's problem asks: how many colors are needed to guarantee that the countries can all be colored, no matter how their boundaries are arranged? Ringel proved that the number of colors needed was at least 8 and at most 12, conjecturing that 8 was the correct answer.
Again, one can phrase the same question equivalently as one in graph theory, with a single vertex for each pair of a country and its colony, and an edge for each adjacency between countries or colonies. As in the planar case, after this transformation, it is the vertices that must be colored, with different colors for the endpoints of each edge. The graphs that result in this version of the problem are biplanar graphs, or equivalently the graphs of thickness two: their edges can be partitioned into two subsets (the edges coming from Earth adjacencies and those coming from Moon adjacencies) such that the corresponding two subgraphs are both planar. In mathematical terms, Ringel's problem asks for the maximum chromatic number of biplanar graphs.
Bounds
A biplanar graph on vertices has at most edges (double the number that a planar graph can have), from which it follows from the degree sum formula that it has at least one vertex with at most 11 neighbors. Removing this vertex, coloring the remaining graph recursively, and then using the smallest-numbered unused color for the removed vertex leads to a coloring with at most 12 colors; this is the greedy coloring for a degeneracy ordering of the graph. Therefore, biplanar graphs require at most 12 colors.
An example of a biplanar graph requiring 9 colors can be constructed as the join of a 6-vertex complete graph and a 5-vertex cycle graph. This means that these two subgraphs are connected by all possible edges from one subgraph to the other. The resulting graph has 11 vertices, and requires 6 colors for the complete subgraph and 3 colors for the cycle subgraph, giving 9 colors overall. This construction, by Thom Sulanke in 1974, disproved the conjecture of Ringel that 8 colors would always suffice. Subsequently, an infinite family of biplanar 9-critical graphs (minimal graphs that require nine colors) has been constructed.
Despite a lack of further progress on the problem, in 2018 Ellen Gethner conjectured that the correct number of colors for this problem is 11. She suggests several candidates for 10-chromatic biplanar graphs, including the graph obtained as the strong product of a cycle graph with a clique, and the graph obtained by removing any vertex from . These graphs can be shown to require 10 colors, because they have no independent set large enough to be the largest color class in a coloring with fewer colors. Additionally, they meet the bounds on the number of edges a biplanar graph can have. However, a representation of them as biplanar graphs (or Earth–Moon maps) remains elusive.
Application
One application of colorings of biplanar graphs involves testing printed circuit boards for short circuits. The electrical conductors within these boards include crossings, but (for double-sided printed circuit boards) their adjacencies can be assumed to form a biplanar graph. After coloring this graph, short circuits between adjacent conductors can be detected by adding extra circuitry to connect all conductors with the same colors to each other and testing for connections between pairs of different colors. With some care, this idea can be used to reduce the number of tests needed per circuit to only four.
Generalizations
Various generalizations of the problem have also been considered, including versions of the problem with more than two planets or with countries that can have more than one region per planet. Maps with one planet and multiple regions per country give Heawood's empire problem. Maps with more than two planets but only one region per planet correspond to graphs whose thickness is at most equal to the number of planets. For these graphs, more precise (although still incomplete) results are known. For the graphs of thickness , and the corresponding -planet maps, the chromatic number is at most by the same degeneracy argument used in the Earth–Moon problem. As well, for , a complete graph with vertices has thickness , showing some of these graphs require colors. Thus, in this case, the upper and lower bounds are within two colors of each other.
References
External links
Graph coloring
Unsolved problems in graph theory | Earth–Moon problem | [
"Mathematics"
] | 1,591 | [
"Unsolved problems in mathematics",
"Graph coloring",
"Graph theory",
"Unsolved problems in graph theory",
"Mathematical relations",
"Mathematical problems"
] |
72,684,114 | https://en.wikipedia.org/wiki/SU%20Cygni | SU Cygni is a triple star system in the northern constellation of Cygnus, abbreviated SU Cyg. The primary component of the system is a classical Cepheid variable with a period of 3.84559 days. The changing luminosity of this star causes the system to vary in brightness from a peak apparent visual magnitude of 6.44 down to magnitude 7.22 over the course of its cycle. The distance to this system is approximately 3,000 light years based on parallax measurements, and is the most accurate distance among Cepheids. It is a member of the Turner 9 open cluster of stars.
The variable luminosity of this star was announced by G. Müller and G. Kempf in 1898. The following year, M. Luizet determined a period of 3.846 days. In 1906, the radial velocity of this star was found to be variable by J. D. Maddrill, with its cycle matching the luminosity period but trailing in phase by half a day. By 1916 it was classified as a Cepheid variable, with spectrographic studies showing that the spectral type varied over the course of each cycle. It ranged from a class of A6 near peak luminosity down to F7 at minimum.
A companion star, designated component B, was detected photometrically by B. F. Madore in 1977, with the colors suggesting a B-type main-sequence star with a class of B6–7V. This finding was supported by observations of J. D. Fernie in 1979, who determined a class of B6V. In 1984, M. Imbert measured an orbital period of 549.2 days for the pair, with an orbital eccentricity (ovalness) of 0.35. Ultraviolet observations with the IUE spacecraft in 1985 showed that the companion is a close binary system with a period of 4.7 days. The members of this pair have classes of B8 and A0. In 1998, the B-type companion was found to be a chemically peculiar HgMn star.
There is a candidate comoving companion star located at an angular separation of to the west of SU Cyg. It is an A-type main-sequence star with a class of A2V. This star does not appear to be gravitationally bound to SU Cyg.
References
Further reading
F-type supergiants
Classical Cepheid variables
B-type main-sequence stars
A-type main-sequence stars
Mercury-manganese stars
Triple star systems
Cygnus (constellation)
7518
Durchmusterung objects
186688
97150
Cygni, SU | SU Cygni | [
"Astronomy"
] | 546 | [
"Cygnus (constellation)",
"Constellations"
] |
74,098,232 | https://en.wikipedia.org/wiki/Mantamonas%20vickermani | Mantamonas vickermani is a species of marine heterotrophic flagellates described in 2021. It belongs to the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs.
Description
Like other Mantamonas species, M. vickermani are heterotrophic unicellular protists with one anterior and one posterior flagellum in each cell. The transcriptome of Mantamonas vickermani is estimated to be 21 megabases long, with 9,561 unique proteins.
Ecology
Mantamonas vickermani was isolated from a marine sediment sample collected in 2014 from the shallow marine lagoon , in the Mljet National Park on the island of Mljet, Croatia.
References
Protists described in 2021
Podiata | Mantamonas vickermani | [
"Biology"
] | 167 | [
"Eukaryotes",
"Eukaryote stubs"
] |
74,098,497 | https://en.wikipedia.org/wiki/Rubidium%20permanganate | Rubidium permanganate is the permanganate salt of rubidium, with the chemical formula .
Preparation
Rubidium permanganate can be formed by the reaction of potassium permanganate and rubidium chloride:
Properties
Physical
Rubidium permanganate is soluble in water with a solubility of 6.03 g/L at 7 °C, 10.6 g/L at 19 °C, and 46.8 g/L at 60 °C. Its crystal structure is orthorhombic, the same as caesium permanganate, ammonium permanganate and potassium permanganate.
Chemical
Similar to potassium permanganate, the two-step decomposition of rubidium permanganate leads to the formation of rubidium manganate intermediates. It breaks down into manganese dioxide, rubidium oxide and oxygen. The decomposition temperature is between 200 and 300 °C. Drift-away oxygen caused an 8% mass loss in the product.
Total reaction:
Uses
In qualitative analysis, rubidium permanganate is used as a reagent to detect perchlorate ions. It is produced as an intermediate from rubidium nitrate and potassium permanganate and precipitates with existing perchlorate ions as RbClO4·RbMnO4 mixed crystal.
References
Rubidium compounds
Permanganates | Rubidium permanganate | [
"Chemistry"
] | 279 | [
"Oxidizing agents",
"Permanganates"
] |
74,099,038 | https://en.wikipedia.org/wiki/NGC%204253 | NGC 4253 is a barred spiral galaxy located in the constellation Coma Berenices. It is located at a distance of about 185 million light years from Earth, which, given its apparent dimensions, means that NGC 4253 is about 65,000 light years across. It was discovered by William Herschel on February 3, 1788. It is a Seyfert galaxy.
Characteristics
The NGC 4253 is a barred galaxy with thick bar, while the arms form a ring. Marquez et al. suggested that the galaxy has a secondary bar perpendicular to the main bar, although that could be an artifact due to the presence of strong dust lanes and no inner bar is visible in images by WFPC2 F606W of the Hubble Space Telescope. There is evidence of star formation along the dust lanes in the leading egde of the bar, especially at the east half.
The nucleus of NGC 4253 has been found to be active and it has been categorised as a narrow line type I Seyfert galaxy. The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 5506 is estimated to be 1–13 × based on reverberation mapping of the hydrogen lines, based on time lag spectra, and based on X-ray variations.
The nucleus emits X-rays. The X-rays have been found to vary in intensity, exhibiting quasi-periodic oscillation, although this phenomenon appears to be transient. The variability was found by ROSAT X-ray satellite. The intensity varied by a factor of 3 every 6,450 seconds (about 1.8 hours) based on observations by XMM-Newton in 2005, while in 2000 that period was estimated to be 4,200 seconds. It has been suggested that the source of the oscillation lies at the inner part of the accretion disk.
The galaxy has been found to host a maser and is a compact source in radiowaves.
Nearby galaxies
NGC 4253 belongs to a galaxy group known as LGG 276. Other members of this group includes the galaxies NGC 4131, NGC 4134, NGC 4169, NGC 4174, NGC 4175, NGC 4185, NGC 4196, NGC 4132, MCG 5-29-24, MCG 5-29-35, UGC 7221, and UGC 7294. NGC 4245 lies at a projected distance of 16.5 arcminuntes.
See also
NGC 4593 – a similar barred galaxy which hosts an active nucleus
NGC 5506 – another similar Seyfert galaxy
References
External links
NGC 4253 on SIMBAD
Barred spiral galaxies
Ring galaxies
Seyfert galaxies
Coma Berenices
4253
07344
Markarian galaxies
39525
Discoveries by William Herschel
Astronomical objects discovered in 1788 | NGC 4253 | [
"Astronomy"
] | 598 | [
"Coma Berenices",
"Constellations"
] |
74,100,836 | https://en.wikipedia.org/wiki/Process%20safety%20management | Process safety management (PSM) is a practice to manage business operations critical to process safety. It can be implemented using the established OSHA scheme or others made available by the EPA, AIChE's Center for Chemical Process Safety, or the Energy Institute.
PSM schemes are organized in 'elements'. Different schemes are based on different lists of elements. This is a typical list of elements that may be reconciled with most established PSM schemes:
Commit to process safety
Process safety culture
Compliance with standards
Process safety competency
Workforce involvement
Stakeholder outreach
Understand hazards and risks
Process knowledge and documentation management
Hazard identification and risk analysis
Manage risk
Operating procedures
Safe work practices (e.g. a permit-to-work system)
Asset integrity management
Contractor management
Training and performance assurance
Management of change
Operational readiness
Conduct of operations
Emergency management
Learn from experience
Incident investigation
Process safety metrics and performance measurement
Auditing
Management review and continuous improvement
References
Further reading
Process safety
Management by type | Process safety management | [
"Chemistry",
"Engineering"
] | 191 | [
"Chemical process engineering",
"Safety engineering",
"Process safety"
] |
74,101,225 | https://en.wikipedia.org/wiki/Acetone%20hydrazone | Acetone hydrazone (isopropylidenehydrazine) is the product of condensation of acetone and hydrazine, as typical for hydrazone formation. It is an intermediate in the synthesis of .
Acetone hydrazone can be produced on large scale by reaction of acetone azine with hydrazine, a more convenient reaction than direct reaction of acetone and hydrazine. Likewise, it is susceptible to disproportionation to revert to acetone azine and hydrazine, especially in the presence of water.
The chemical is one of the metabolic products of the antihypertensive pharmaceutical hydralazine, and itself also have antihypertensive effects.
References
Hydrazones | Acetone hydrazone | [
"Chemistry"
] | 147 | [
"Functional groups",
"Organic compounds",
"Hydrazones",
"Organic compound stubs",
"Organic chemistry stubs"
] |
74,102,918 | https://en.wikipedia.org/wiki/Pure%204D%20N%20%3D%201%20supergravity | In supersymmetry, pure 4D supergravity describes the simplest four-dimensional supergravity, with a single supercharge and a supermultiplet containing a graviton and gravitino. The action consists of the Einstein–Hilbert action and the Rarita–Schwinger action. The theory was first formulated by Daniel Z. Freedman, Peter van Nieuwenhuizen, and Sergio Ferrara, and independently by Stanley Deser and Bruno Zumino in 1976. The only consistent extension to spacetimes with a cosmological constant is to anti-de Sitter space, first formulated by Paul Townsend in 1977. When additional matter supermultiplets are included in this theory, the result is known as matter-coupled 4D supergravity.
Flat spacetime
To describe the coupling between gravity and particles of arbitrary spin, it is useful to use the vielbein formalism of general relativity. This replaces the metric by a set of vector fields indexed by flat indices such that
In a sense the vielbeins are the square root of the metric. This introduces a new local Lorentz symmetry on the vielbeins , together with the usual diffeomorphism invariance associated with the spacetime indices . This has an associated connection known as the spin connection defined through , it being a generalization of the Christoffel connection to arbitrary spin fields. For example, for spinors the covariant derivative is given by
where are gamma matrices satisfing the Dirac algebra, with . These are often contracted with vielbeins to construct which are in general position-dependent fields rather than constants. The spin connection has an explicit expression in terms of the vielbein and an additional torsion tensor which can arise when there is matter present in the theory. A vanishing torsion is equivalent to the Levi-Civita connection.
The pure supergravity action in four dimensions is the combination of the Einstein–Hilbert action and the Rarita–Schwinger action
Here is the Planck mass, , and is the Majorana gravitino with its spinor index left implicit. Treating this action within the first-order formalism where both the vielbein and spin connection are independent fields allows one to solve for the spin connections equation of motion, showing that it has the torsion . The second-order formalism action is then acquired by substituting this expression for the spin connection back into the action, yielding additional quartic gravitino vertices, with the Einstein–Hilbert and Rarita–Schwinger actions now being written with a torsionless spin connection that explicitly depends on the vielbeins.
The supersymmetry transformation rules that leave the action invariant are
where is the spinorial gauge parameter. While historically the first order and second order formalism were the first ones used to show the invariance of the action, the 1.5-order formalism is the easiest for most supergravity calculations. The additional symmetries of the action are general coordinate transformations and local Lorentz transformations.
Curved spacetime
The four dimensional super-Poincare algebra in Minkowski spacetime can be generalized to anti-de Sitter spacetime, but not to de Sitter spacetime, since the super-Jacobi identity cannot be satisfied in that case. Its action can be constructed by gauging this superalgebra, yielding the supersymmetry transformation rules for the vielbein and the gravitino.
The action for AdS supergravity in four dimensions is
where is the AdS radius and the second term is the negative cosmological constant . The supersymmetry transformations are
While the bilinear term in the action appears to be giving a mass to the gravitino, it still belongs to the massless gravity supermultiplet. This is because mass is not well-defined in curved spacetimes, with no longer being a Casimir operator of the AdS super-Poinacre algebra. It is however conventional to define a mass through the Laplace–Beltrami operator, in which case particles within the same supermultiplet have different masses, unlike in flat spacetimes.
See also
N = 8 supergravity
References
Supersymmetric quantum field theory
Theories of gravity | Pure 4D N = 1 supergravity | [
"Physics"
] | 881 | [
"Supersymmetric quantum field theory",
"Theoretical physics",
"Theories of gravity",
"Supersymmetry",
"Symmetry"
] |
74,103,466 | https://en.wikipedia.org/wiki/Cerium%20monoselenide | Cerium monoselenide is an inorganic compound with the chemical formula CeSe. It exists in the form of Ce3+Se2−(e−).
Preparation
Cerium monoselenide can be obtained by reducing cerium selenide with metallic sodium at 600 °C (or calcium at 1000 °C):
Ce2Se3 + 2Na → 2CeSe + Na2Se
The reduction of cerium selenide by cerium dihydride can also produce cerium monoselenide:
Ce2Se3 + CeH2 → 3 CeSe + H2↑
Properties
Like many other rare earth monochalcogenides, Cerium monoselenide has metallic-type electrical conductivity and a NaCl-type crystal structure.
References
Cerium(III) compounds
Selenides
Rock salt crystal structure
Electrides | Cerium monoselenide | [
"Chemistry"
] | 174 | [
"Electron",
"Electrides",
"Salts"
] |
74,104,056 | https://en.wikipedia.org/wiki/The%20Sun%20%28Golub%20and%20Pasachoff%20book%29 | The Sun is a 2017 popular science book by Leon Golub and Jay Pasachoff. It describes the current scientific understanding of the structure of the Sun and its influence on Earth's processes. The book contains numerous illustrations, as well as tips on observing the Sun and related astronomical phenomena. It was published in the Kosmos series, which is dedicated to various objects of the Solar System.
Authors
Leon Golub is a senior astrophysicist at the Smithsonian Astrophysical Observatory. Jay M. Pasachoff (1943–2022) was the Field Memorial Professor of Astronomy at Williams College. He was also the director of the Hopkins Observatory and the head of the International Astronomical Union’s Working Group on Solar Eclipses. Pasachoff authored The Peterson Field Guide to the Stars and Planets and co-authored The Cosmos: Astronomy in the New Millennium. Golub and Pasachoff have previously published two popular books on the study of the Sun: The Solar Corona and Nearest Star: The Surprising Science of Our Sun.
Contents
In The Sun, Golub and Pasachoff explore the composition, nature, and significance of the Sun. They provide an account of the history of solar astronomy and discuss the advancements made by scientists. The book covers various aspects of the Sun, including sunspots, their magnetic properties, and their connection to solar activity. The authors also delve into the composition of the Sun's interior, discussing seismic waves and ongoing nuclear fusion processes. They describe valuable insights provided by solar eclipses and observations from space. Furthermore, the book explores the Sun's radiation and solar particles and their effects on Earth. The book features visually appealing images that enhance the understanding of the Sun.
The authors take an unconventional approach by using specific images as the central focus of discussions on various solar phenomena. They emphasize the interconnectedness of scientific research and highlight the interrelationships between natural subjects. Golub and Pasachoff rely on visual representation, incorporating photographic images, visualizations, and spectra. Safety measures for observing the Sun are presented in Appendix I, while Appendices II and III respectively elaborate on observing the Sun during eclipses and from space. The book concludes with a recommended reading list, which includes both popular and technical literature, to encourage further exploration.
Reception
Reviewers have generally praised the book. The short review in Nature states that the authors present a comprehensive scientific overview of the Sun, shedding light on various solar phenomena. They describe the book as "beautifully illustrated, history-rich, and up to date." A review in American Scientist describes the book as "intriguing, accessible, and technically detailed."
In a detailed review in BBC Sky at Night magazine, Mark Townley notes that the book is distinguished by its use of simple language, making it easily readable for non-experts. He states that the authors convey complex concepts through relatable analogies from everyday science. The evolution of scientific understanding is presented through a historical account, departing from the mathematical equations often found in other books on the subject. The reviewer points out that the book could have been improved by providing a detailed description of safe observing techniques and that the authors overemphasize outdated and unsafe methods, such as using a smoked glass or a DVD. In summary, Townley concludes that the book is particularly suitable for beginners seeking a greater understanding of the Sun and its broader influences, and he recommends it to readers.
References
Astronomy books
2017 non-fiction books
Reaktion Books books
American non-fiction books | The Sun (Golub and Pasachoff book) | [
"Astronomy"
] | 710 | [
"Astronomy books",
"Works about astronomy"
] |
74,104,164 | https://en.wikipedia.org/wiki/Hardy%20distribution | In probability theory and statistics, the Hardy distribution is a discrete probability distribution that expresses the probability of the hole score for a given golf player. It is based on Hardy's (Hardy, 1945) basic assumption that there are three types of shots:
good ,
bad and
ordinary ,
where the probability of a good hit equals , the probability of a bad hit equals and the probability of an ordinary hit equals . Hardy further assigned
a value of 2 to a good stroke,
a value of 0 to a bad stroke and
a value of 1 to a regular or ordinary stroke.
Once the sum of the values is greater than or equal to the value of the par of the hole, the number of strokes in question is equal to the score achieved on that hole. A birdie on a par three could then have come about in three ways: , and , respectively, with probabilities , and .
Definitions
Probability mass function
A discrete random variable is said to have a Hardy distribution, with parameters , and if it has a probability mass function given by:
if m is odd
and
if m is even
with
and
where
is the par of the hole ()
is the golf hole score () if is even
is the golf hole score () if is odd
is the probability of a good shot ()
is the probability of a bad shot () and ()
The moment generating function is given by:
if m is odd
and
if m is even
with
and
Each raw moment and each central moment can be easily determined with the moment generating function, but the formulas involved are too large to present here.
Hardy distribution for a par three, four and five
For a par three:
For a par four:
Note the resemblance with . For a par five:
Note the resemblance with the formulas for and .
History
When trying to make a probability distribution in golf that describes the frequency distribution of the number of strokes on a hole, the simplest setup is to assume that there are only two types of strokes:
A good stroke with a probability of
A bad stroke with a probability of .
while
a good shot then gets the value 1 and
a bad shot gets the value 0.
Once the sum of the shot values equals the par of the hole, that is the number of strokes needed for the hole.
It is clear that with this setup, a birdie is not possible. After all, the smallest number of strokes one can get is the par of the hole. Hardy (1945) probably realized that too and then came up with the idea not to assume that there were just two types of strokes: good and bad , but three types:
good with probability
bad with probability
ordinary with probability .
In fact, Hardy called a good shot a supershot and a bad shot a subshot. Minton later called Hardy's supershot an excellent shot and Hardy's subshot a bad shot . In this article, Minton's excellent shot is called a good shot . Hardy came up with the idea of three types of shots in 1945, but the actual derivation of the probability distribution of the hole score was not given until 2012 by van der Ven.
Hardy assumed that the probability of a good stroke was equal to the probability of a bad stroke, namely . This was confirmed by Kang:
In retrospect, Hardy might well have been right, as the data in Table 2 in van der Ven (2013) show. This table shows the estimated - and -values for holes 1-18 for rounds 1 and 2 of the 2012 British Open Championship. The mean values were equal to 0.0633 and 0.0697, respectively. Later Cohen (2002) introduced the idea that and should be different. Kang says about this:
For the Hardy distribution the values of and may be different.
Goodness of fit
The Hardy distribution gives the probability distribution of a single player's hole score. It takes several observations to perform a goodness-of-fit test (see Goodness of fit test) to check whether the Hardy distribution applies or not. This can be done with a single individual by having the individual play the same hole multiple times. Goodness-of-fit tests assume pure replications (see Replication (statistics)). This means that there should be no change in the player's golfing ability during repeated play of the hole. For example, there should not be an ongoing learning process (see Learning). Such effects cannot really be ruled out. One way around this problem is to use multiple players who can be assumed to have approximately the same golf proficiency. Such players are the participants in professional golf tournaments (see PGA Tour). Before using a goodness-of-fit test, it should first be checked that the participants indeed have approximately the same golf proficiency. This can be done separately for each hole by using, for example, the Pearson correlation coefficient between the hole score on the first day and the second day of a tournament. If there are no systematic differences (see Classical test theory) between players, the correlation (see Correlation) between the score achieved on Day 1 on a hole and the score achieved on Day 2 on that hole will not differ significantly (see Statistical significance) from zero. This can be easily tested statistically. In a study by van der Ven, the results of a goodness-of-fit test of the Hardy distribution were reported using the hole-by-hole scores from the 2012 Open Championship played at the St Andrews Golf Club. The distribution has been tested separately for each hole. Pearson's chi-squared test was used to determine whether the observed sample frequencies of the hole scores differed significantly from the expected frequencies according to the Hardy distribution. The fit between observed and expected frequencies was generally very satisfactory.
References
Notes
Probability distributions | Hardy distribution | [
"Mathematics"
] | 1,152 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
74,105,771 | https://en.wikipedia.org/wiki/High%20Meadows%20Environmental%20Institute | High Meadows Environmental Institute (HMEI, formerly the Princeton Environmental Institute, PEI) at Princeton University in Princeton, New Jersey is an interdisciplinary center for environmental research that studies effects of and solutions to climate change and other environmental threats.
The International Center for Climate Governance named the Princeton Environmental Institute the second-highest climate change think tank in the global category for 2012,
following the Belfer Center for Science and International Affairs.
The High Meadows Environmental Institute is an interdisciplinary center for environmental research that includes over 120 researchers from 29 departments. Researchers study the causes and impacts of climate change and other key environmental issues involving energy, food, water, and biodiversity. Long-term projects include the Carbon Mitigation Initiative, the Center for Biocomplexity, and the Integrated Ground Water Modeling Center. Grand Challenges and other initiatives focus on climate change and infectious disease, food and the environment, ecohydrology, urban resilience, and sustainable development.
History
The Princeton Environmental Institute was founded in 1994 as part of a broader initiative led by university president Harold T. Shapiro, to make Princeton a center for addressing global environmental challenges. Shapiro met with Tom Barron, Robert H. Socolow and Henry S. Horn in 1992 to discuss the university's possible direction. Shapiro then formed a faculty committee which recommended the creation of the Princeton Environmental Institute. In December 1995, the Institute moved into the newly-renovated Guyot Hall.
The founding director of the institute in 1994 was Simon Levin.
François M. M. Morel held the position of Director twice, first between 1998 and 2004.
Ignacio Rodríguez-Iturbe, who served as acting director of the institute in 2002, founded the field of ecohydrology.
Stephen W. Pacala was Acting Director of the Princeton Environmental Institute from 2005 to 2006, and Director from 2006 to 2014. François M. M. Morel returned for a second time as Director from 2014-2017.
The Director of the institute from 2017-2021 was Michael Celia, the Theodora Shelton Pitney Professor of Environmental Studies and professor of civil and environmental engineering at Princeton.
As of July 2021, the Director became Gabriel Vecchi.
In 2000, the institute established the Carbon Mitigation Initiative (CMI) in partnership with BP. The Carbon Mitigation Initiative has identified eight major carbon mitigation strategies or "wedges" for reducing human-based carbon emissions.
In 2014, with funding from the National Science Foundation (NSF), the institute established the Southern Ocean Carbon and Climate Observations and Modeling project (SOCCOM), to study the Southern Ocean's role in climate regulation.
In 2019, the institute received $2.5 million in federal funding to study resilience and sustainability in urban food systems.
In 2020, the Institute received a gift to create the Thomas A. and Currie C. Barron Family Biodiversity Research Challenge Fund to support research on the preservation of species and ecosystems.
The Princeton Environmental Institute was renamed as the High Meadows Environmental Institute, following a gift from Judy and Carl Ferenbach III's High Meadows Foundation in 2020.
The High Meadows Environmental Institute (HMEI) is projected to move to a new building at Princeton in early 2025.
References
Environmental research institutes
Research institutes in New Jersey
Environmental organizations based in New Jersey
Environmental organizations established in 1994
Research institutes established in 1994
1994 establishments in New Jersey
Science and technology in New Jersey
Think tanks based in the United States
Princeton University | High Meadows Environmental Institute | [
"Environmental_science"
] | 688 | [
"Environmental research institutes",
"Environmental research"
] |
74,108,772 | https://en.wikipedia.org/wiki/Delandistrogene%20moxeparvovec | Delandistrogene moxeparvovec, sold under the brand name Elevidys, is a recombinant gene therapy used for the treatment of Duchenne muscular dystrophy. It is designed to deliver into the body a gene that leads to production of Elevidys micro-dystrophin that contains selected domains of the dystrophin protein present in normal muscle cells. It is an adeno-associated virus vector-based gene therapy that is given by intravenous infusion (slow injection into a vein).
The most commonly reported side effects include vomiting, nausea, acute liver injury, pyrexia (fever), and thrombocytopenia (abnormally low platelet count in the blood).
Delandistrogene moxeparvovec was approved for medical use in the United States in June 2023. It was developed by Sarepta Therapeutics, together with Roche, and is manufactured by Catalent.
Medical uses
Delandistrogene moxeparvovec is indicated for the treatment of ambulatory and non-ambulatory individuals four years of age and older with Duchenne muscular dystrophy with a confirmed mutation in the Duchenne muscular dystrophy gene.
Delandistrogene moxeparvovec is designed to deliver into the body a gene that leads to production of Elevidys micro-dystrophin, a shortened protein (138 kDa, compared to the 427 kDa dystrophin protein of normal muscle cells) that contains selected domains of the dystrophin protein present in normal muscle cells. FDA states that the conditional approval is based on detection of successful gene expression; evidence of clinical improvement is still pending.
In the phase 3 randomized clinical trial published in Nature Medicine, Elevidys AAV gene therapy for Duchenne muscular dystrophy failed to show statistically significant motor function improvement. The study included 125 ambulatory male patients aged 4-8 years (63 in therapy group, 62 in placebo group). Mean motor function assessment score changes were 2.57 points in the Elevidys group and 1.92 points in the placebo group, with a non-significant difference of 0.65 points at the 52-week endpoint.
History
The accelerated US Food and Drug Administration (FDA) approval of delandistrogene moxeparvovec was based on data from a randomized clinical trial that established that delandistrogene moxeparvovec increased the expression of the Elevidys micro-dystrophin protein observed in delandistrogene moxeparvovec-treated individuals aged four to five years with Duchenne muscular dystrophy.
Society and culture
Economics
Initial pricing was announced at for a single treatment which is expected to last a lifetime.
References
External links
Biotechnology
Approved gene therapies
Medical treatments
Muscle stabilizers
Muscle protectors | Delandistrogene moxeparvovec | [
"Biology"
] | 622 | [
"nan",
"Biotechnology"
] |
74,109,565 | https://en.wikipedia.org/wiki/GB%20stroke-based%20order | The GB stroke-based order, full name GB13000.1 Character Set Chinese Character Order (Stroke-Based Order) (GB13000.1字符集汉字字序（笔画序）规范), is a standard released by the State Language Commission of China in 1999. It is the current national standard for stroke-based sorting, and has been applied to the arrangement of the List of Commonly Used Standard Chinese Characters (通用规范汉字表), and the new versions of Xinhua Zidian and Xiandai Hanyu Cidian, etc.
GB13000.1 is a Chinese national standard equivalent to the international standard of the Chinese character set of ISO/IEC 10646:1993, or Unicode 1.1. It is a large character set of 20,902 Chinese characters used in China, Japan and Korea (CJK).
The standard of GB stroke-based order includes two parts: (a) the sorting rules, and (b) a table with all the CJK characters of GB13000.1 Character Set sorted in standard stroke-based order.
Sorting rules
The rules for sorting Chinese characters are as follows.
1. Rule of stroke counts
First, compare the numbers of strokes of the two Chinese characters to be sorted. If they are different, the one with less strokes is put before the one with more strokes. For example, character 十(2 strokes) is before 干 (3), 沛 (7) before 泣 (8), 爱 (10) before 愛 (13).
The strokes of a character are usually counted by the stroke order, to avoid missing or re-counting some of the strokes. For example, the stroke order of traditional Chinese character 愛 (love) is "㇓㇔㇔㇓㇔㇇㇔㇟㇔㇔㇓㇇㇏", altogether 13 strokes.
2. Rule of stroke orders
When the number of strokes of the two Chinese characters are the same, their corresponding strokes are compared pair by pair according to stroke order to make order of the characters. The strokes of Chinese characters are divided into five groups: 1. heng (héng, 横, horizontal; this group include primary stroke ㇐ and secondary stroke ㇀), 2. shu (shù, 竖, vertical, including primary 丨 and secondary 亅), 3. pie (piě, 撇, left falling, only stroke 丿, no secondary), 4. dian (diǎn, 点, dot, including primary 丶 and secondary ㇏), and 5. zhe (乛, fold, including primary 乛, and secondary ㇕, ㇅, ㇎, ㇡, ㇋, ㇊, ㇍, ㇈, ㇆, ㇌, ㇗, ㇞, ㇉, ㇙, ㇄, ㇟, ㇜, ㇛, ㇁, ㇢, ㇂, etc.). A stroke of group heng is before a stroke of group shu, group shu is before group pie, group pie is before group dian, and group dian is before group zhe. This is the so-called heng-shu-pie-dian-zhe (横竖撇点折) stroke group order.
For example, both characters 二 and 十 have two strokes, and both start with stroke 一. The second stroke of 二 is again 一 of the heng group, while the second stroke in 十 is 丨 of the shu group. According to the heng-shu-pie-dian-zhe order, heng is before shu, hence character 二 is before 十. Similarly, we have: 十 before 厂, 乃 before 又, and 义 before 叉.
In China Mainland, there are two currently effective standards for stroke orders. One is the Stroke Orders of the Commonly-used Standard Chinese Characters (通用规范汉字笔顺规范), with stroke order of each character represented in specific strokes, e.g., 好: ㇛㇓㇐㇇㇚㇐. The other is GB13000.1 Character Set Chinese Character Stroke Orders (GB13000.1字符集汉字笔顺规范), with stroke orders represented in the five group numbers, e.g., 好: 531521.
In Taiwan, there is the standard of Handbook of Stroke Orders of Standard Commonly-used Chinese Characters (常用國字標準字體筆順手冊)
3. Rules of primary-secondary strokes
When the number of strokes and the stroke orders of two Chinese characters are the same, compare the primary and secondary strokes pair by pair by stroke orders according to the following rules.
3.1 The primary and secondary stroke forms of the heng, shu and dian groups
The primary stroke form comes before the secondary stroke forms. The order of stroke forms in each group is defined as follows.
Primary stroke form 一 is before secondary stroke ㇀, primary 丨 before secondary 亅, primary 丶 before secondary strokes in the order of ㇏ 乁 乀. For example, 子 is before 孑, 干 before 于, and 夕 before 久.
3.2 The primary and secondary stroke forms of the zhe group
First, sort according to the number of turning points, the stroke with fewer turning points is before the ones with more turning points. For example: 山 (stroke order:㇑㇗㇑) is before 巾 (㇑㇆㇑), because their first stroke are the same, and the second stroke of 山 is ㇗ (with one turning point) while the second stroke of 巾 (i.e.,㇆) has two turning points. Other examples are: 化 is before 仉, and 刀 before 乃.
When the number of turning points are the same, then sort according to the heng-shu-pie-dian order of the starting segments of the two zhe strokes. For example: 幻 and 乣, the last strokes of the characters (㇆ and ㇟) both have 2 turning points, but ㇆ starts with segment 一 while ㇟ starts with 丨. Therefore, 幻 comes before 乣. Similarly, we have 云 before 弌.
When the number of turning points and the starting segment are the same, sort according to the segments after the turning point in the heng-shu-pie-dian order. For instance: 凡 and 及. The second strokes ㇈ and ㇋ both start with 一. but after the first turning points, the second stroke segment of ㇈ is ㇑, while in ㇋ it is ㇓. ㇑ is before ㇓, hence 凡 is before 及.
4. Rules of stroke combinations
When the number of strokes, stroke orders, and primary and secondary strokes are the same, compare the combinations of strokes.
The combinational relationships of strokes are divided into separation, connection and intersection. Separation is before connection, and connection before intersection. For example, character 八 is before 人, and 人 is before 乂.
When they are both connected, sort according to the modes of connection. Head-head connected strokes go before tail-head connected strokes, tail-head connected before tail-tail connected, and tail-tail connected before body connected. For example, 目 is before 且, where the last stroke 一 of 且 is in body connection. If both characters are in body connection, then sort according to the strokes being connected in the order of heng-shu-pie-dian-zhe, for example, 人 is before 入.
When there is only a difference in the location of strokes separation between the two characters, upper part separation is before lower part separation, and left-right separation is before up-down separation. For example: 玊 is before 玉, and 埒 is before 埓.
When two characters differ only in the proportion of stroke length, the short-long proportion is before long-short proportion. Such as: 未 is before 末, 土 before 士.
5. Rules of structures
If two characters have the same number of strokes, stroke orders, primary and secondary strokes, and stroke combinations, they are ordered according to their (component) structures. A character in left-right structure is before a character in up-down structure, the left-center-right structure is before the up-middle-bottom structure, and the up-down structure is before the surrounding structure. For example: 旼 is before 旻, 嚻 is before 囂, and 旮 is before 旭. When the structures are the same, but the sizes of the whole characters are different, the smaller character comes first. Such as, 口 is before 囗.
Chinese characters should be sorted based on their real forms, employing the sorting rules one by one in the previous order. Make sure that a rule is used only when sorting can not be fulfilled by the rules before it, until all characters are properly ordered.
The sorting rules for the GB13000.1 Chinese Characters Set are applicable to other character sets as well. When the characters increase, the rules can be increased accordingly, and the character orders of different character sets can be kept compatible with each other.
Table of the GB13000.1 Character Set in stroke-based order
In this table (Chinese name: GB13000.1字符集汉字字序表), all the 20,902 CJK (China, Japan and Korea) Chinese characters are sorted in standard order, covering over 700 A4 pages. Each character is represented by an entry, with the contents of: "serial number, Chinese character, number of strokes, stroke order, and Unicode, etc". For example, the entry of character 札 is “407, 札, 5, 12345, 672D”.
Stroke order is in numerical form of 1, 2, 3, 4, 5 representing the five groups of heng, shu, pie, dian and zhe respectively. A sample of the first two pages of the table can be found on the Web .
To look up a character (such as character 福, blessing, good fortune） in the table, use the sorting rules in the same order. First, according to Rule 1, count the number of strokes (福, ㇔㇇㇑㇔㇐㇑㇕㇐㇑㇕㇐㇑㇐, has 13 strokes), then turn to a page with characters of 13 strokes (all characters are first sorted by stroke counts). Secondly, convert the stroke order to the digital form (福, ㇔(4) ㇇(5) ㇑(2) ㇔(4) ㇐(1) ㇑(2) ㇕(5) ㇐(1) ㇑(2) ㇕(5) ㇐(1) ㇑(2) ㇐(1), 4524125125121), then look up the target character with that stroke order among the characters of the stroke count (福 is on page 425 of the book, character number 12197). Among the 13-stroke characters, only "禊 福 禋 禖" start with 45241. That means only checking the first 5 strokes will reduce the search range to 4 characters, from which you can quickly find the target character without checking more strokes. And a skillful student can directly compare the groups of strokes between two characters stroke by stroke until the target is found.
Comments
Radical-based sorting, sound-based sorting, four-corner sorting and stroke-based sorting are the methods commonly used in modern Chinese dictionaries. Among them, stroke-based sorting is usually used in all the other methods to improve their performance: in radical-based sorting to sort the index of radicals, the characters in each radical family, as well as the index of characters difficult to look up; in sound-based sorting to sort homophone characters; in four-corner sorting to sort characters of the same code. That means stroke-based sorting is indispensable for Chinese lexicography.
GB13000.1 Character Set Chinese Character Order (Stroke-Based Order) has greatly improved the accuracy of stroke-based ordering by adding more layers of sorting rules, making it possible to sort large character set with high accuracy without support from other sorting methods. But the involvement of many layers (or tiers) of rules and comparisons make word lookup very time-consuming.
The best thing is to use only one tier of sorting only, like what happens in the English alphabetical sorting. Or at most use two tiers for accurate sorting, while making sure that the user can look up a character or word conveniently with the first layer only. To this end, a new comer has made a quite good contribution: The YES method is a simplified stroke-based sorting method free of stroke counting and grouping. And it has been successfully applied to the indexing of all the characters in Xinhua Zidian (新华字典) and Xiandai Hanyu Cidian (现代汉语词典), as well as the 20,902 Unicode CJK characters.
See also
Chinese character strokes
Stroke-based sorting
Modern Chinese characters
Notes
References
Chinese character collation
Chinese character components | GB stroke-based order | [
"Technology"
] | 2,593 | [
"Components",
"Chinese character components"
] |
74,109,941 | https://en.wikipedia.org/wiki/ADB-5%27Br-PINACA | ADB-5'Br-PINACA (5'-Br-ADB-PINACA) is an indazole-3-carboxamide based synthetic cannabinoid receptor agonist that has been sold as a designer drug. It was first identified in Abu Dhabi in September 2022 but has subsequently been found in the US and Europe. While formal pharmacology studies have not yet been carried out, ADB-5'Br-PINACA is believed to be a highly potent synthetic cannabinoid with similar potency to compounds such as MDMB-FUBINACA and 5F-ADB, which have been responsible for numerous fatal and non-fatal drug overdoses, consistent with previously reported compounds from the patent literature showing bromination of the indazole ring at the 5-, 6-, or 7- positions to increase potency over the unsubstituted analogues. ADB-5'Br-PINACA is the 5'-bromo analog of ADB-PINACA.
Synthesis
ADB-5'Br-PINACA can be synthesized from a "half finished" synthesis precursor known as ADB-5-Br-INACA, related to MDMB-5Br-INACA.
Legality
ADB-5'Br-PINACA is not specifically scheduled in the United States at the federal level as of October 20, 2023 but may be considered illegal under the federal analogue act if intended for consumption as a structural analog of the Schedule I cannabinoid ADB-PINACA.
See also
6-Bromopravadoline
ADB-PINACA
ADB-5'F-BUTINACA
ADMB-3TMS-PRINACA
ADSB-FUB-187
MDMB-5'Br-INACA
MDMB-5'Br-BUTINACA
References
Cannabinoids
Designer drugs
Bromoarenes
Amides
Tert-butyl compounds
Indazolecarboxamides | ADB-5'Br-PINACA | [
"Chemistry"
] | 407 | [
"Amides",
"Functional groups"
] |
74,110,097 | https://en.wikipedia.org/wiki/Kleene%20equality | In mathematics, Kleene equality, or strong equality, () is an equality operator on partial functions, that states that on a given argument either both functions are undefined, or both are defined and their values on that arguments are equal.
For example, if we have partial functions and , means that for every :
and are both defined and
or and are both undefined.
Some authors are using "quasi-equality", which is defined like this:
where the down arrow means that the term on the left side of it is defined.
Then it becomes possible to define the strong equality in the following way:
References
Computability theory
Equivalence (mathematics) | Kleene equality | [
"Mathematics"
] | 134 | [
"Computability theory",
"Mathematical logic"
] |
74,112,422 | https://en.wikipedia.org/wiki/1%2C2-Dimorpholinoethane | 1,2-Dimorpholinoethane is an organic chemical and specifically a nitrogen-oxygen heterocyclic compound. At room temperature it is a solid with a melting point of 75 °C. It has two tertiary amines in the same molecule meaning it is ideal for use as a polyurethane catalyst. It has the CAS Registry Number 1723-94-0 and is TSCA and REACH registered and on EINECS with the number 217-026-5. The IUPAC name is 4-(2-morpholin-4-ylethyl)morpholine and the chemical formula C10H20N2O2.
Synonyms
Section reference.
4,4'-Ethylenedimorpholine
4,4'-(Ethane-1,2-diyl)bismorpholine
Morpholine, 4,4'-(1,2-ethanediyl)bis-
1,2-Di-N-morpholinylethane
Morpholine,4,4'-(1,2-ethanediyl)bis-
Morpholine, 4,4'-ethylenedi-
Uses and synthesis
As the molecule has two tertiary nitrogen atoms in the molecule, the substance finds use as a catalyst for polyurethane including PU foams.
1,2-Dimorpholinoethane has been used to make transition metal complexes. As there are two nitrogen atoms in the molecule it acts as a bidentate ligand in these complexes. These complexes have then be used in antibacterial applications.
Toxicity
The toxicity of the compound and tertiary amines in general has been studied and published.
References
Catalysis
Heterocyclic compounds with 2 rings
Tertiary amines
4-Morpholinyl compounds | 1,2-Dimorpholinoethane | [
"Chemistry"
] | 377 | [
"Catalysis",
"Chemical kinetics"
] |
74,112,797 | https://en.wikipedia.org/wiki/Protosterol%20biota | The protosterol biota is a group of organisms found in fossilized fats that comprised aquatic protosterol-producing bacteria and ancient deep-branching stem-group eukaryotes from 1.6 to 0.8 billion years ago. These organisms were more complex than today's bacteria and they predate the last common ancestors of all modern eukaryotes. Perhaps they hunted their own species, since they were predators, as they fed on other bacteria. They were present in large numbers in the aquatic environments of the seas and seriously affected the Earth's ecosystem at the time. These microorganisms adapted to the much lower oxygen levels of the era and are also thought to have produced protosteroids.
The experts from the Australian National University and the University of Bremen found fossils of fats that were formed 1.6 billion years ago. They found the fossils in the Barney Creek Formation in Northern Australia, near Borroloola, which was covered by seawater. In the findings, the researchers noticed chemical signals that suggested that the molecules may have come from an ancestor of the last common eukaryotic ancestor from which fungi, plants and animals all evolved. The research revealed that eukaryotes already existed on Earth 1.6 billion years ago.
References
Precambrian paleobiotas
Proterozoic life
Precambrian fossils
Paleoproterozoic
Fossils of Australia | Protosterol biota | [
"Biology"
] | 287 | [
"Precambrian paleobiotas",
"Prehistoric biotas"
] |
74,113,016 | https://en.wikipedia.org/wiki/Welkom%20mining%20explosion | At least 31 people are suspected to have died in a methane gas explosion at a disused gold mine in South Africa around the third week of May in 2023.
The Department of Mineral Resources and Energy (DMRE) reported late on that the miners had died in a mining shaft at the abandoned Virginia mine in Welkom, Free State. The miners, believed to be foreign nationals from Lesotho who were there mining illegally, may have died on or around .
Background
The mine, previously owned by Harmony Gold, had last been operational during the 1990s. Most of the victims were from the district of Berea in Lesotho.
Initial reports
Gwede Mantashe, South African minister of mineral resources and energy, stated that Harmony had noted that there was dust coming out of the ventilation shaft on , which they believe was the day of the disaster, but had not suspected anything because the mine was closed. Mantashe also stated that Harmony was informed of the incident on , via the consulate of Lesotho.
The foreign ministry of Lesotho informed the South African high commissioner in Maseru of the disaster on , after family members of some of the victims had reported them missing.
Investigation
Harmony considers the incident a criminal matter, and has been helping with an investigation. At the time the DMRE first publicized the incident, they had determined that the level of methane in Shaft 5, where the victims had died, was very high, preventing the safe retrieval of the other bodies. Three bodies had previously been retrieved by other miners.
Response
Makhabane Peete, a traditional chief of the district, stated that the affected families only sought the retrieval and repatriation of the bodies.
See also
2009 Harmony Gold mine deaths
Notes
References
2023 disasters in South Africa
2023 mining disasters
Explosions in 2023
Gas explosions
Explosions in South Africa
Gold mining disasters
History of the Free State (province)
Illegal mining
May 2023 events in South Africa
Mining disasters in South Africa | Welkom mining explosion | [
"Chemistry"
] | 394 | [
"Natural gas safety",
"Gas explosions"
] |
74,113,390 | https://en.wikipedia.org/wiki/Periplocin | Periplocin is a plant-derived glycoside whereby the sugar moiety is linked to a steroid. It can be extracted from cortex periplocae (CPP), the dry root of Periploca sepium.
CPP's healing activities have long been recognized in traditional Chinese medicine where it has been used to treat rheumatoid arthritis. Scientific studies of CPP have identified over 100 components of which periplocin has been a major focus both for its toxicity as well as for its potential beneficial pharmaceutical effects. Besides the cardiac glycosides with periplocin as its main constituent, the CPP contains different C21-steroidal glycosides such as periplocodides and pregnene derivatives, fatty acids, volatile oils, terpenes, and others.
Higher doses of periplocin are toxic as a cardiac glycoside.
Potential medical applications of periplocin are focused on these areas:
Anti-inflammatory effects. Periplocin and its derivatives have shown anti-inflammatory effects.
Antitumor activity. A number of in vivo and in vitro studies suggest that periplocin inhibits tumor growth. Studies show both inhibition of growth as well as induction of apoptosis.
Cardiotonic activity. Traditional use includes an application for heart failure. Structure and function of cardiac muscle were improved in rats.
Periplocin's metabolites, periplocymarin and periplogenin, have also shown some pharmacological effects.
Potential senolytic activity was suggested by an AI structural analysis of over 4,000 chemicals in 2013.
References
Plant toxins
Cardiac glycosides
Steroids | Periplocin | [
"Chemistry"
] | 356 | [
"Chemical ecology",
"Plant toxins"
] |
74,113,779 | https://en.wikipedia.org/wiki/Protosteroid | A protosteroid or primordial fat is a lipid precursor, which can be transformed during subsequent biochemical reactions and finally become steroid. The protosteroids are biomarkers that are produced by ancient eukaryotes belonged to the microorganisms in the protosterol biota. The intermediate compounds created by these eukaryotes while making crown sterol molecules.
For the first time, the German biochemist and Nobel laureate Konrad Emil Bloch thought that instead of today's sterols, earlier life forms could have used chemical intermediates in their cells. He called these intermediates protosteroids. Later researchers synthesized protosteroids called lanosterol, cycloartenol, and 24-methylene cycloartenol. Then researchers from the Australian National University and the University of Bremen found protosteroids in rocks that formed 1.6 billion years ago in the Barney Creek Formation in Northern Australia. The researchers also found derivatives that matched the pattern produced by 24-methylene cycloartenol in 1.3-billion-year-old rocks.
References
Precambrian fossils
Fossils of Australia
Lipids
Biomarkers
Sterols | Protosteroid | [
"Chemistry",
"Biology"
] | 246 | [
"Organic compounds",
"Biomolecules by chemical classification",
"Biomarkers",
"Lipids"
] |
68,304,037 | https://en.wikipedia.org/wiki/NGC%207544 | NGC 7544 is a lenticular galaxy located in the constellation Pisces. It was discovered by the astronomer Albert Marth on November 18, 1864.
References
External links
Pisces (constellation)
7544
Lenticular galaxies | NGC 7544 | [
"Astronomy"
] | 47 | [
"Pisces (constellation)",
"Constellations"
] |
68,305,758 | https://en.wikipedia.org/wiki/Urey%E2%80%93Bigeleisen%E2%80%93Mayer%20equation | In stable isotope geochemistry, the Urey–Bigeleisen–Mayer equation, also known as the Bigeleisen–Mayer equation or the Urey model, is a model describing the approximate equilibrium isotope fractionation in an isotope exchange reaction. While the equation itself can be written in numerous forms, it is generally presented as a ratio of partition functions of the isotopic molecules involved in a given reaction. The Urey–Bigeleisen–Mayer equation is widely applied in the fields of quantum chemistry and geochemistry and is often modified or paired with other quantum chemical modelling methods (such as density functional theory) to improve accuracy and precision and reduce the computational cost of calculations.
The equation was first introduced by Harold Urey and, independently, by Jacob Bigeleisen and Maria Goeppert Mayer in 1947.
Description
Since its original descriptions, the Urey–Bigeleisen–Mayer equation has taken many forms. Given an isotopic exchange reaction , such that designates a molecule containing an isotope of interest, the equation can be expressed by relating the equilibrium constant, , to the product of partition function ratios, namely the translational, rotational, vibrational, and sometimes electronic partition functions. Thus the equation can be written as: where and is each respective partition function of molecule or atom . It is typical to approximate the rotational partition function ratio as quantized rotational energies in a rigid rotor system. The Urey model also treats molecular vibrations as simplified harmonic oscillators and follows the Born–Oppenheimer approximation.
Isotope partitioning behavior is often reported as a reduced partition function ratio, a simplified form of the Bigeleisen–Mayer equation notated mathematically as or . The reduced partition function ratio can be derived from power series expansion of the function and allows the partition functions to be expressed in terms of frequency. It can be used to relate molecular vibrations and intermolecular forces to equilibrium isotope effects.
As the model is an approximation, many applications append corrections for improved accuracy. Some common, significant modifications to the equation include accounting for pressure effects, nuclear geometry, and corrections for anharmonicity and quantum mechanical effects. For example, hydrogen isotope exchange reactions have been shown to disagree with the requisite assumptions for the model but correction techniques using path integral methods have been suggested.
History of discovery
One aim of the Manhattan Project was increasing the availability of concentrated radioactive and stable isotopes, in particular 14C, 35S, 32P, and deuterium for heavy water. Harold Urey, Nobel laureate physical chemist known for his discovery of deuterium, became its head of isotope separation research while a professor at Columbia University. In 1945, he joined The Institute for Nuclear Studies at the University of Chicago, where he continued to work with chemist Jacob Bigeleisen and physicist Maria Mayer, both also veterans of isotopic research in the Manhattan Project. In 1946, Urey delivered the Liversidge lecture at the then-Royal Institute of Chemistry, where he outlined his proposed model of stable isotope fractionation. Bigeleisen and Mayer had been working on similar work since at least 1944 and, in 1947, published their model independently from Urey. Their calculations were mathematically equivalent to a 1943 derivation of the reduced partition function by German physicist Ludwig Waldmann.{{efn|Bigeleisen & Mayer (1947) contains the addendum:}}
Applications
Initially used to approximate chemical reaction rates, models of isotope fractionation are used throughout the physical sciences. In chemistry, the Urey–Bigeleisen–Mayer equation has been used to predict equilibrium isotope effects and interpret the distributions of isotopes and isotopologues within systems, especially as deviations from their natural abundance. The model is also used to explain isotopic shifts in spectroscopy, such as those from nuclear field effects or mass independent effects. In biochemistry, it is used to model enzymatic kinetic isotope effects. Simulation testing in computational systems biology often uses the Bigeleisen–Mayer model as a baseline in the development of more complex models of biological systems. Isotope fractionation modeling is a critical component of isotope geochemistry and can be used to reconstruct past Earth environments as well as examine surface processes.
See also
Timeline of the Manhattan Project
Isotope-ratio mass spectrometry
Hydrogen isotope biogeochemistry
Notes
References
External links
Biochemistry methods
Biogeochemistry
Chemical oceanography
Earth system sciences
Equations
Isotopes
Manhattan Project
University of Chicago | Urey–Bigeleisen–Mayer equation | [
"Physics",
"Chemistry",
"Mathematics",
"Biology",
"Environmental_science"
] | 902 | [
"Biochemistry methods",
"Environmental chemistry",
"Mathematical objects",
"Isotopes",
"Equations",
"Chemical oceanography",
"Biogeochemistry",
"Nuclear physics",
"Biochemistry"
] |
68,306,965 | https://en.wikipedia.org/wiki/Immortality%20Bus | The Immortality Bus is a 1978 Wanderlodge that has been made to appear as a 38-foot brown coffin.
The bus was used by Zoltan Istvan and various other transhumanist activists during his 2016 US presidential campaign to deliver a Transhumanist Bill of Rights to the US Capitol and to promote the idea that death can be conquered by science. The nearly four-month journey of the art vehicle from San Francisco to Washington, DC in 2015 had embedded journalists and documentarians, including those from The New York Times, Der Spiegel, The Verge, The Telegraph, and others.
On board the bus were drones, virtual reality gear, a 4-foot robot named Jethro Knights, biohacking equipment, posters about transhumanism, and nootropics for riders to try. An open invitation to anyone in America was made to travel on the bus. The Immortality Bus has become one of the most widely recognized life extension activist projects and has been featured in several documentaries and articles on the history of the life extensionist movement.
Journey
After a successful crowd funding campaign of $27,380 on Indiegogo, Zoltan Istvan bought the 1978 Wanderlodge in Sacramento, California. In his front yard in Mill Valley, California, he and his team converted the bus into an art vehicle that resembled a 38-foot casket, including plastic flowers on top.
The Immortality Bus left the San Francisco Bay Area on September 5, 2015. It headed to Tehachipi, California where it attended GrindFest, and riders of the bus, including Vox’s Dylan Matthews and Zoltan Istvan were implanted with microchips. From there the bus headed to Las Vegas, then San Diego, and then Arizona to visit life extension group People Unlimited and the Alcor cryonics facility.
After visiting Alcor the bus traveled to Texas for campaign events and then went to Arkansas to protest against marijuana prohibition. It stopped at events in Mississippi before illegally entering a megachurch in Alabama where activists handed out pamphlets on transhumanism. In Alabama it also visited the historic Freedom Riders museum, where Zoltan argued that cyborg rights will be another upcoming civil rights battle.
In Charlotte, North Carolina, John McAfee (then the Presidential candidate of the Cyber Party) visited the bus and debated Zoltan Istvan.
The Immortality Bus team later made speeches at Florida's Church of Perpetual Life (co-founded by William Faloon), and Zoltan lectured using his avatar in Second Life as part of a virtual event with Terasem.
In its final stages, the bus traversed up the eastern seaboard before arriving on November 14, 2015, to the US Capitol. On the steps of the Supreme Court, Zoltan Istvan wrote the original Transhumanist Bill of Rights before posting it on the US Capitol on November 15. Improved versions of the Transhumanist Bill of Rights have since been made via internet crowdsourcing organized by the Transhumanist Party, with version 2.0 published in 2017 and version 3.0 published in 2018.
After the journey
Once a relatively unknown candidate, the Immortality Bus and the media coverage it generated helped Zoltan Istvan place 4th (behind John McAfee, Gary Johnson, and Jill Stein) in an iQuanti survey of Google searches of all Presidential candidates not Democratic or Republican.
In a feature article on the bus, The New York Times Magazine called the Immortality Bus “the great brown sarcaphogaus of the American Highway. It was a methaphor of life itself.” Short video stories of the Immortality Bus were made by The Atlantic, CNET, BuzzFeed, Vocativ, RT, and Australia's Viceland.
Pulitzer Prize winning journalist Jonathan Weiner wrote that the journey of the Immortality Bus is modeled after Ken Kesey and the Merry Pranksters famous cross country bus trip, which helped inspire a generation of activists. The Immortality Bus is the subject of the closing chapter of the Wellcome Prize winning book by Mark O’Connel, To Be a Machine, and also the subject of a chapter in Radicals by Jamie Bartlett.
The documentary Immortality or Bust , which focused on the Immortality Bus campaign, won the breakout award at the 2019 Raw Science Film Festival in Los Angeles as well as the Best Biohacking Awareness Award at the 2021 GeekFest Toronto. Independent distributor Gravitas picked up the documentary and the film is available on iTunes and Amazon Prime.
The bus is currently parked in long-term storage in Virginia, and Zoltan Istvan is working to donate the bus to a museum that will use it to promote life extension.
Criticism
Some transhumanists were dismayed with the amount of media attention the Immortality Bus received. They believed it was a stunt and sent a frivolous message about the seriousness of the life extension movement. Other transhumanists countered that such activism helps grow the movement and raise awareness. USA Today called the bus "a morbid Oscar Meyer Wienermobile".
External links
http://www.immortalitybus.com/
References
Transhumanism
Individual buses
Art vehicles
Decorated vehicles
Customised buses
Life extension | Immortality Bus | [
"Technology",
"Engineering",
"Biology"
] | 1,055 | [
"Genetic engineering",
"Transhumanism",
"Ethics of science and technology"
] |
68,307,066 | https://en.wikipedia.org/wiki/Giuseppe%20Palazzotto | Giuseppe Palazzotto (1702 – 1764) was an Italian architect, active in Catania, Sicily. He used a Baroque style, and was employed extensively during the flurry of reconstruction, after the 1693 Sicily earthquake which nearly flattened his native city.
Giuseppe helped design the church and monastery of San Giuliano, Santa Chiara, Sant'Agostino, Palazzo Zappala, Palazzo del Senato, and the Palazzo Biscari.
References
1706 births
1764 deaths
People from Catania
18th-century Italian architects | Giuseppe Palazzotto | [
"Engineering"
] | 107 | [
"Architecture stubs",
"Architecture"
] |
68,307,189 | https://en.wikipedia.org/wiki/Jean%20Lynch-Stieglitz | Jean Lynch-Stieglitz is a paleoceanographer known for her research on reconstructing changes in ocean circulation over the last 100,000 years.
Education and career
An interest in the natural world, combined with the logic of science and math, attracted Lynch-Stieglitz to science and after a summer at the Duke University Marine Laboratory she decided on a career in physical oceanography. In 1986, she earned B.S. degrees in physics and geology from Duke University and for two years she worked as an oceanographer at the Pacific Marine Environmental Laboratory. From 1988 until 1989 she worked at the Maryland Science Center and as a programmer at Johns Hopkins University before moving to Columbia University where she earned an M.A. (1991) and Ph.D. (1995) in geological sciences. After two years as a postdoctoral scholar at Woods Hole Oceanographic Institution, in 1996 she returned to New York where she joined the faculty of the Lamont–Doherty Earth Observatory. In 2004, Lynch-Stieglitz moved to the Georgia Institute of Technology where she was promoted to professor in 2010.
From 2012 to 2015, Lynch-Stieglitz was the Editor of Earth and Planetary Science Letters.
In 2015 Lynch-Stieglitz was elected a fellow of the American Association for the Advancement of Science "for bringing physical oceanography approaches to the study of transient circulation changes during ice ages, providing a window into the ocean’s interaction with today’s climate change."
Research
Lynch-Stieglitz's research links the ocean and climate over the past 100,000 years. She has used carbon isotopes in benthic foraminifera to reconstruct air-sea exchange in carbon isotopes, changes in the movement of deep water masses, and Antarctic Intermediate Water in the transitions between glacial and interglacial periods. In the Atlantic Ocean, she has examined movement of the Gulf Stream during the Last Glacial Maximum and linked changes in the Atlantic meridional overturning circulation and to rapid changes in climate. Her research also extends to regions where ice alters the exchange of carbon dioxide between atmosphere and ocean in glacial periods, and work in the Pacific Ocean where she has examined sea surface temperatures from the Last Glacial Maximum to the present.
Selected publications
Awards and honors
Kavli Frontiers of Science Fellow, National Academy of Sciences (1998)
Fellow, American Association for the Advancement of Science (2015)
Cesare Emiliani Lecturer, American Geophysical Union (2018)
Fellow, American Geophysical Union (2019)
References
External links
Duke University alumni
Columbia Graduate School of Arts and Sciences
Georgia Tech faculty
Fellows of the American Geophysical Union
Women oceanographers
American climatologists
Geochemists
Year of birth missing (living people)
Living people
Lamont–Doherty Earth Observatory people | Jean Lynch-Stieglitz | [
"Chemistry"
] | 557 | [
"Geochemists"
] |
68,307,248 | https://en.wikipedia.org/wiki/Margaret%20Torn | Margaret Torn is an ecologist at Lawrence Berkeley National Laboratory known for her research on carbon cycling, especially with respect to the interactions between soils and the atmosphere.
Education and career
Torn grew up in Marin county and worked in the family's food business, the Torn Ranch, where they handled nuts and dried fruits. She started college at the College of Marin before transferring to University of California, Berkeley. She earned a B.S. (1984), an M.S. (1990), and a Ph.D. (1994) from the University of California, Berkeley. From 1994 until 1998, Torn was a postdoctoral fellow at University of California Irvine and Stanford University. In 1998, she joined the Earth Sciences Division at Lawrence Berkeley National Laboratory, and was promoted to senior scientist in 2013. Beginning in 2018, she is also an adjunct professor at the University of California, Berkeley. In 2015 she received an honorary doctorate from the University of Zurich.
In 2017, Torn was named a fellow of the American Geophysical Union who cited her as follows:
Research
Torn's research combines observational data and experimental manipulations to examine the impact of changing climate conditions on the carbon cycle, with a focus on the interactions between soils and atmosphere. Torn has experimentally warmed soils and then measured the impact of changing conditions on gas fluxes from the soils. She works on the factors controlling the release of greenhouse gases from the tundra in the north slope of Alaska, how climate change impacts the severity of forest fires, the carbon sequestered in fungi found in soils, and the decomposition of black carbon using archived soil samples from Russia. One theme in her research is assessing the factors that govern the persistence of organic carbon in soil.
Selected publications
Awards and honors
Presidential Early Career Award for Scientists and Engineers (2003)
Fellow, American Geophysical Union (2017)
Berkeley Lab Director's award for exception achievement in science (2017)
References
External links
, October 13, 2011
Fellows of the American Geophysical Union
University of California, Berkeley alumni
Lawrence Berkeley National Laboratory people
American climatologists
Soil scientists
Women ecologists
Biogeochemists
Year of birth missing (living people)
Living people
Recipients of the Presidential Early Career Award for Scientists and Engineers
Women soil scientists | Margaret Torn | [
"Chemistry"
] | 450 | [
"Geochemists",
"Biogeochemistry",
"Biogeochemists"
] |
68,308,315 | https://en.wikipedia.org/wiki/Violuric%20acid | Violuric acid is an organic compound with the formula HON=C(CONH)2CO. It crystallizes as white or off-white monohydrate. The compound has attracted attention because its salts are deeply colored.
Reactions
It readily deprotonated to give salts of the anion [ON=C(CONH)2CO]−, which are often deeply colored.
Preparation
It was prepared by Adolf Baeyer by reaction of barbituric acid with nitrous acid. It can also be produced by condensation of alloxan with hydroxylamine. as typical for forming the oxime of other carbonyl compounds.
Analytical reagents
Violuric acid and many of its derivatives, such as thiovioluric acid, 1,3-dimethylvioluric acid, and diphenylthiovioluric acid, have historically been used as analytical reagents for spectrophotometric determination and titration of various metals and metal-ions. It was also used as a novel staining/spraying agent for inorganic paper chromatography to identify and separate metals based on color. Most derivatives of violuric acid will also typically form brightly colored salts with most metals and nitrogen bases.
Because of the characteristic and diverse colors that violuric acid forms with alkali metals, it has been used photometrically to determine the amount of sodium in blood serum.
References
Barbiturates
Nitroso compounds
Oximes | Violuric acid | [
"Chemistry"
] | 311 | [
"Functional groups",
"Oximes"
] |
68,310,852 | https://en.wikipedia.org/wiki/Nitride%20chloride | A chloride nitride is a mixed anion compound containing both chloride (Cl−) and nitride ions (N3−). Another name is metallochloronitrides. They are a subclass of halide nitrides or pnictide halides.
The group 4 element chloride nitrides can be intercalated by alkali metals that supply extra electrons, and other molecules such as from solvents like tetrahydrofuran, yielding layered substances that are superconductors. A superconductor transition temperature Tc of 25.5K has been achieved.
Production
Nitride chlorides may be produced by heating metal nitrides with metal chlorides. The ammonolysis process heats a metal chloride with ammonia. A related method heats a metal or metal hydride with ammonium chloride. The nitrogen source could also be an azide or an amide.
List
References
Chlorides
Nitrides
Mixed anion compounds | Nitride chloride | [
"Physics",
"Chemistry"
] | 200 | [
"Matter",
"Chlorides",
"Inorganic compounds",
"Mixed anion compounds",
"Salts",
"Ions"
] |
68,312,748 | https://en.wikipedia.org/wiki/Papposaurus | Papposaurus is an extinct genus of proterogyrinid embolomere which lived in the Mississippian (early Carboniferous) of Scotland. It is known from a single species, Papposaurus traquiairi, which is based on an isolated femur discovered in ironstone near Loanhead. Though originally compared closely to reptiles, subsequent study has revealed closer similarity to basal embolomeres such as Proterogyrinus and Archeria. With such limited remains, Papposaurus may not be a valid genus. The femur was redescribed in 1986 by T. R. Smithson, who considered Papposaurus traquairi a nomen vanum possibly synonymous with Proterogyrinus scheelei.
References
Embolomeres
Nomina dubia
Serpukhovian life
Mississippian sarcopterygians of Europe
Fossil taxa described in 1914 | Papposaurus | [
"Biology"
] | 185 | [
"Biological hypotheses",
"Nomina dubia",
"Controversial taxa"
] |
68,312,817 | https://en.wikipedia.org/wiki/Right%20to%20repair | Right to repair is a legal right for owners of devices and equipment to freely modify and repair products such as automobiles, electronics, and farm equipment. Right to repair may also refer to the social movement of citizens putting pressure on their governments to enact laws protecting a right to repair.
Common obstacles to repair include requirements to use only the manufacturer's maintenance services, restrictions on access to tools and components, and software barriers.
Proponents for this right point to the benefits in affordability, sustainability, and availability of critical supplies in times of crisis.
Impacts
While initially driven majorly by automotive consumers protection agencies and the automotive after sales service industry, the discussion of establishing a right to repair not only for vehicles but for any kind of electronic product gained traction as consumer electronics such as smartphones and computers became universally available causing broken and used electronics to become the fastest growing waste stream. Today it's estimated that more than half of the population of the western world has one or more used or broken electronic devices at home that are not introduced back into the market due to a lack of affordable repair.
In addition to the consumer goods, healthcare equipment repair access made news at the start of the COVID-19 pandemic in 2020, when hospitals had trouble getting maintenance for some critical high-demand medical equipment, most notably ventilators.
The pandemic has also been credited with helping to grow the right-to-repair movement since many repair shops were closed. The Economist also cites the expectation that owners of products should be able to repair them as a sense of moral justice or property rights. Those fighting against planned obsolescence have also taken note of when repair costs exceeds replacement costs because the companies that created the product have retained a monopoly on its repair, driving up prices.
Definition
Right to repair refers to the concept that end users of technical, electronic or automotive devices should be allowed to freely repair these products. Some notable aspects of a product include:
the device should be constructed and designed in a manner that allows repairs to be made easily;
end users and independent repair providers should be able to access original spare parts and necessary tools (software as well as physical tools) at fair market conditions;
repairs should, by design, be possible and not be hindered by software programming; and
the repairability of a device should be clearly communicated by the manufacturer.
Some goals of the right to repair are to favor repair instead of replacement, and make such repairs more affordable leading to a more sustainable economy and reduction in electronic waste.
Repair-friendly design
The use of glue or proprietary screws can make repairs more difficult. In general, proprietary parts and accessories can make products more difficult to repair, such as Apple's "Lightning" charging ports and adapters, which require a non-standard process to repair, leading the European Union to standardize charging ports for small devices, requiring all devices to use USB-C.
Accessible spare parts and tools
Parts and tools needed to make repairs, should be available to everyone, including consumers.
Software
Parts pairing is when a company does not allow parts to be swapped without a password that they provide to preferred technicians. New ways to lock devices like part pairing (components of a device are serialized and can not be swapped against others) became increasingly popular among manufacturers, including digital rights management. Using approved parts can increase the cost of the repair, leading many consumers to speed up their upgrade cycle to a new device.
In addition to access to software updates, the ability to install third-party software is also mentioned as a major goal, which would, for example, allow some devices to be adapted over time.
Transparency
Manuals and design schematics should be freely available and help consumers know how to repair their devices.
History
The strategy to continuously change products to create continuous demand for the latest generation was pursued at a large scale by General Motors executive Alfred P. Sloan. GM overtook Ford as the biggest American automaker and planned obsolescence with annual variants of a product became widely adopted across industries in the American economy, eventually becoming adopted by Ford by 1933.
The car industry was at the forefront of establishing the concept of certified repair: starting from the 1910s, Ford established certified dealerships and service networks to promote parts made by Ford instead of independent repair shops and often after-sales parts. Ford also pushed for standardized pricing among certified repair shops, making flat fees mandatory even for different repairs. The combination of annual updates to cars and components made it more difficult for independent repair shops to maintain a stock of parts.
A couple of court cases have required products with repaired or refurbished components to be labeled as "used."
In 1947, a business owner was refurbishing old spark plugs and reselling them. However, he was reselling them under a trademarked name. This led to a lawsuit that provided the framework for legislation that would provide a right to resell repaired or refurbished items, as long as they were labelled correctly.
Champion Spark Plug Co. v. Sanders provided the basis of FTC guidelines which provides an uninfringeable right to resell repaired or refurbished items as long as they were labeled as such. The decision also provided the framework for trademark guidelines regarding the resale of used goods under a trademarked namesake.
FTC guidelines Title 16, Chapter I, Subchapter B, Part 20 provides guidance and regulations on the labeling of items that have been “rebuilt”, “refurbished”, or “re-manufactured” in order to prevent unfair competitive advantage in selling components in the automobile industry. This guideline hence allowed businesses the ability to repair items, for resale later.
Some manufacturers shifted towards more repairable designs. Apple, which rose quickly to become one of the largest computer manufacturers, sold the first computers with circuit board descriptions, easy-to-swap components, and clear repair instructions.
Copyright with regard to computer software source code also became a front on the limitation of repairability. In the U.S., the Digital Millennium Copyright Act of 1998 prohibits repairs unless granted an exception, and has been used to block repairs as software became more common in a range of devices and appliances.
To prevent refilling of empty ink cartridges, manufacturers had started placing microchips counting fill levels and usage, rendering refills difficult or impossible. Reselling and refurbishing products was confirmed to be legal by the Supreme Court in 2017 in Impression Prods., Inc. v. Lexmark Int'l, Inc.. As of 2022, complaints about the longevity and repairability of printers remains.
In the early 2000s, the automotive industry defeated the first proposal of a right to repair bill for the automotive sector. While the National Automotive Service Task Force (NASTF), an organization supported by the automotive industry, established an online directory for accessing manufacturer information and tools in 2001, a study conducted by the Terrance Group found that around 59% of independent repair services continued to struggle to get access to diagnostic tools and parts from manufacturers. The share of electronic components in the total bill of materials for a car also rose from 5% in the 1970s to over 22% in 2000. The increasing hybridization of cars brought the need of special tools that a manufacturer only shared with authorized repair services.
A trend towards right to repair in automotive and other industries gained traction with more proposed laws and court decisions. While initially driven by automotive consumers protection agencies and the automotive after-sales service industry, the discussion of establishing a right to repair for any kind of industrially produced device gained traction as consumer electronics such as smartphones and computers became widely used, alongside advanced computerized integration in farming equipment. The movement was also backed by climate change activists aiming to reduce e-waste.
The first successful implementation of a right to repair came when Massachusetts passed the United States' first right to repair law for the automotive sector in 2012, which required automobile manufacturers to sell the same service materials and diagnostics directly to consumers or to independent mechanics as they used to provide exclusively to their dealerships. As a result, major automobile trade organizations signed a Memorandum of Understanding in January 2014 using the Massachusetts law as the basis of their agreement for all 50 states starting in the 2018 automotive year.
Companies like Apple, John Deere, and AT&T have lobbied against Right to Repair bills, and created a number of "strange bedfellows" from high tech and agricultural sectors on both sides of the issue, according to Time. The tech industry has lobbied in opposition through groups like TechNet, the Entertainment Software Alliance ("ESA"). The Association of Equipment Manufacturers ("AEM") and their dealership counterparts the Equipment Dealers Association's 2018 Statement of Principles became the subject of media backlash when in January 2021 the promised means to make complete repairs had not been visibly available.
In late 2017, users of older iPhone models discovered evidence that recent updates to the phone's operating system, iOS, were throttling the phone's performance. This led to accusations that Apple sabotaged the performance of older iPhones to compel customers to buy new models more frequently. Apple disputed this assumed intention, stating instead that the goal of the software was to prevent overtaxing older lithium-ion batteries, which have degraded over time, to avoid unexpected shutdowns of the phone. Furthermore, Apple allowed users to disable the feature in an iOS update but advised against it. Additionally, Apple allowed users of affected iPhones to obtain service to replace batteries in their phones for a reduced cost of service ( compared to ) for the next six months. However, the "right to repair" movement argued that the best outcome would be Apple allowing consumers to purchase third-party batteries and possess the instructions to replace it at a lower cost.
In April 2018, the Federal Trade Commission sent notice to six automobile, consumer electronics, and video game console manufacturers, later revealed through a Freedom of Information Act request to be Hyundai, Asus, HTC, Microsoft, Sony, and Nintendo, stating that their warranty practices may violate the Magnuson-Moss Warranty Act. The FTC specifically identified that informing consumers that warranties are voided if they break a warranty sticker or seal on the unit's packaging, use third-party replacement parts, or use third-party repair services is a deceptive practice, as these terms are only valid if the manufacturer provides free warranty service or replacement parts. Both Sony and Nintendo released updated warranty statements following this notice.
In April 2018, US Public Interest Research Group issued a statement defending Eric Lundgren over his sentencing for creating the ‘restore disks’ to extend the life of computers.
In 2018, the exemption for making software modifications to "land-based motor vehicles" was expanded to allow equipment owners to engage the services of third parties to assist with making changes. These changes were endorsed by the American Farm Bureau Federation. In its 2021 recommendations, the Library of Congress further extend the exemption, with favorable right-to-repair considerations for automobiles, boats, agricultural vehicles, and medical equipment, as well as modifying prior rules related to other consumer goods.
Senator Elizabeth Warren, as part of her campaign for president, laid out plans for legislation related to agriculture in March 2019, stated her intent to introduce legislation to affirm the right to repair farm equipment, potentially expanding this to other electronic devices.
In August 2019, Apple announced a program where independent repair shops may have the ability to buy official replacement parts for Apple products. Several operators became Authorized under their "IRP" program but many smaller repair operators avoided the option due to legally onerous burdens.
In the 2010s the trend of making one's repairs to devices spread from the east into the Western Europe. In July 2017, the European Parliament approved recommendations that member states should pass laws that give consumers the right to repair their electronics, as part of a larger update to its previous Ecodesign Directive from 2009 which called for manufacturers to produce more energy-efficient and cleaner consumer devices. The ability to repair devices is seen by these recommendations as a means to reduce waste to the environment. With these recommendations, work began on establishing the legal Directive for the EU to support the recommendations, and from which member states would then pass laws to meet the Directive. One of the first areas of focus was consumer appliances such as refrigerators and washing machines. Some were assembled using adhesives instead of mechanical fasteners which made it impossible for consumers or repair technicians from making non-destructive repairs. The right-to-repair facets of appliances were a point of contention and lobbying between European consumer groups and appliance manufacturers. Ultimately, the EU passed legislation in October 2019 that required manufacturers of appliances to be able to supply replacement parts to professional repairmen for ten years from manufacture. The legislation did not address other facets related to right-to-repair, and activists noted that this still limited the consumer's ability to perform their own repairs. Sweden also offers tax breaks for people who repair their own goods.
The EU also has directives toward a circular economy which are aimed toward reducing greenhouse gas emissions and other excessive wastes through recycling and other programs. A 2020 "Circular Economy Action Plan" draft included the electronics right to repair for EU citizens to allow device owners to replace only malfunctioning parts rather than replace the entire device, reducing electronics waste. The Action Plan included additional standardization that would aid toward rights to repair, such as common power ports on mobile devices.
In the midst of the COVID-19 pandemic, where medical equipment became critical for many hospitals, iFixit and a team of volunteers worked to publish and make accessible the largest known collection of manuals and service guides for medical equipment, using information crowdsourced from hospitals, medical institutions and sites like Frank's Hospital Workshop. iFixit had found, like with consumer electronics, some of the more expensive medical equipment had used means to make non-routine servicing difficult for end-users and requiring authorized repair processes.
2020 Massachusetts Question 1 passed to update the previous measure on automobile repair to include electronic vehicle data. Before it could come into effect, in June 2023, the federal National Highway Traffic Safety Administration instructed manufacturers to ignore the 2020 Massachusetts law, asserting it was preempted by federal law because opening telematics to other organizations could make cars more vulnerable to computer hackers. (Both claims are disputed by Massachusetts in the lawsuit.)
In May 2021, the Federal Trade Commission (FTC) issued a report "Nixing the Fix" to Congress that outlined issues around corporations' policies that limit repairs on consumer goods that it considered in violation of trade laws, and outlined steps that could be done to better enforce this. This included self-regulation by the industries involved, as well as expansion of existing laws such as the Magnuson-Moss Warranty Act or new laws to give the FTC better enforcement to protect consumers from overzealous repair restrictions.
In July 2021, the Biden administration issued an executive order to the FTC and the Department of Agriculture to widely improve access to repair for both consumers and farmers. The executive order to the FTC included instructions to craft rules to prevent manufacturers from preventing repairs performed by owners or independent repair shops. About two weeks later, the FTC voted unanimously to enforce the right to repair as policy and to look to take action against companies that limit the type of repair work that can be done at independent repair shops.
Apple announced in November 2021 that it would be allowing consumers to order parts and make repairs on Apple products, initially with iPhone 12 and 13 devices but eventually rolling out to include Mac computers. Reception to the program has been mixed, with Right to Repair advocate Louis Rossmann seeing the program as a step in the right direction, but criticized the omission of certain parts, and the need to input a serial number before ordering parts.
In 2021, France created a repairability scoring system that took inspiration from iFixit's scorecard. France expressed its intent to merge it into a 'Durability index' that also considers how long items are expected to last.
In 2022, Apple started enabling customers to repair batteries and screens. Additionally, Apple has prevented companies from repairing or refurbishing Apple's products without their permission. These action have irritated consumers who believe Apple is against the right to repair.
In 2022, Framework Computer, Adafruit, Raspberry Pi, among other computer systems, started sharing 3D-printable models for replacement parts.
On December 28, 2022, New York Governor Kathy Hochul signed into law the Digital Fair Repair Act, nearly seven months after it had passed the state senate. The law established the right of consumers and independent repairers to get manuals, diagrams, and original parts from manufacturers, although The Verge, Engadget, and Ars Technica noted that the bill was made less vigorous by way of last-minute changes that provided exceptions to original equipment manufacturers. It will apply to electronic devices sold in the state in 2023.
John Deere announced in January 2023 that it was signing a memorandum of understanding with the American Farm Bureau Federation agreeing that American farmers had the right to repair their own equipment or have it serviced at independent repair shops in the United States. Consumers and independent repair centers would still be bound against divulging certain trade secrets, and cannot tamper or override emission control settings, but are otherwise free to repair as they see fit.
In 2023, three business professors cautioned that right-to-repair laws by themselves, could have unintended consequences including incentivizing companies to create cheaper products that are lower-cost and less repairable or durable, or raise the initial sale price of the item.
The U.S. Copyright Office, as part of the tri-annual review of exemptions for the Digital Millennium Copyright Act, approved an exemption for bypassing technical controls for retail-level commercial food preparation equipment for the purposes of repair and maintenance. Notoriously, the inability for third-party repairs of such equipment had been the cause of numerous McDonald's ice cream machines being out-of-service, as the manufacturer, Taylor Company, had only allowed themselves to repair these machines.
Enacted legislation
United States
European Union
Adopted on May 30, 2024, the European Union's Right to Repair Directive (R2RD) requires manufacturers to offer repair services that are both efficient and affordable, while also making sure consumers are aware of their repair rights. Previously, the right to repair in the EU was regulated by the Sale of Goods Directive and the different product-specific Commission Regulations provided under the Ecodesign Directive.
See also
Decompilation
Do it yourself
Open-design movement
Open source
Patch (computing)
Unofficial patch
Repair Café
Repair monopoly
Reverse engineering
Take-back system
Tool library
References
External links
Repair.org - website of the Repair Association (US-based group of mostly smaller repair professionals and firms that support Right to Repair policies)
Pirg.org/campaigns/right-to-repair - website for the U.S. Public Interest Research Group's (PIRG's) right to repair campaign. US PIRG is a leading advocate for right to repair legislation at both the state and federal level.
Repair.eu - website of the Right to Repair Europe Coalition, which represents over 170 organizations from 27 European countries. It includes environmental NGOs and repair actors such as community repair groups, social economy actors, spare parts distributors, self-repairers, repair and refurbishing businesses.
iFixit.com - website for iFixit's right to repair campaign page. iFixit is a leading source of online information regarding device repair and a leading advocate for right to repair laws.
Consumer protection
Intellectual property law
Maintenance
Mechanical engineering
Prevention
Product lifecycle management
Rights
Consumer electronics | Right to repair | [
"Physics",
"Engineering"
] | 3,994 | [
"Maintenance",
"Applied and interdisciplinary physics",
"Mechanical engineering"
] |
68,313,171 | https://en.wikipedia.org/wiki/Lichenopeltella%20cladoniarum | Lichenopeltella cladoniarum is a species of fungus belonging to the class Dothideomycetes. It has been found growing on the podetia of Cladonia arbuscula in Bulgan district, Mongolia and Yamanashi prefecture in Japan.
References
Dothideomycetes
Fungi described in 1995
Fungi of Asia
Lichenicolous fungi
Fungus species | Lichenopeltella cladoniarum | [
"Biology"
] | 76 | [
"Fungi",
"Fungus species"
] |
68,313,686 | https://en.wikipedia.org/wiki/Lichenopeltella%20uncialicola | Lichenopeltella uncialicola is a species of fungus belonging to the class Dothideomycetes. The species was discovered in Iceland in 2010 where it was found growing on Cladonia uncialis. Since then, it has been found on a different host species, Cladonia rangiferina, in North-Korea, Italy Austria, and Greenland.
References
Dothideomycetes
Fungi described in 2010
Fungi of Iceland
Fungi of Europe
Fungus species | Lichenopeltella uncialicola | [
"Biology"
] | 94 | [
"Fungi",
"Fungus species"
] |
68,313,984 | https://en.wikipedia.org/wiki/Lichenoconium%20pyxidatae | Lichenoconium pyxidatae is a species of lichenicolous fungus belonging to the class Dothideomycetes. It has a Holarctic distribution being found in Alaska and various parts of Russia, including Siberia, Franz Josef Land, Novaya Zemlya and Wrangel Island.
Host species
Lichenoconium pyxidatae is known to infect numerous host species. It has a preference to growing on the podium of Cladonia lichens. Known host species include:
Cladonia chlorophaea (sensu lato)
Cladonia coniocraea
Cladonia deformis
Cladonia macroceras
Cladonia macrophylla
Cladonia pocillum
Cladonia pyxidata
Cladonia rangiferina
some unidentified Cladonia species
References
Dothideomycetes
Fungi described in 1900
Fungus species
Fungi of North America
Fungi of Russia | Lichenoconium pyxidatae | [
"Biology"
] | 180 | [
"Fungi",
"Fungus species"
] |
68,314,015 | https://en.wikipedia.org/wiki/Chemical%20finishing%20of%20textiles | Chemical finishing of textiles refers to the process of applying and treating textiles with a variety of chemicals in order to achieve desired functional and aesthetic properties. Chemical finishing of textiles is a part of the textile finishing process where the emphasis is on chemical substances instead of mechanical finishing. Chemical finishing in textiles also known as wet finishing. Chemical finishing adds properties to the treated textiles. Softening of textiles, durable water repellancy and wrinkle free fabric finishes are examples of chemical finishing.
Finish
Textile finishing is the process of converting the loom state or raw goods into a useful product, which can be done mechanically or chemically. Finishing is a broad term that refers to a variety of physical and chemical techniques and treatments that finish one stage of textile production while also preparing for the next. Textile finishing can include aspects like improving surface feel, aesthetic enhancement, and adding advanced chemical finishes. A finish is any process that transforms unfinished products into finished products. This includes mechanical finishing and chemical applications which alter the composition of treated textiles (fiber, yarn or fabric.)
Mechanical finishes
Mechanical finish refers to machine finishes such as embossing, heat setting, Sanforizing, shearing, luster imparting, surface finishes, and glaze finishes.
Chemical finishes
Chemical finishes are chemicals that may alter the properties of the treated fabrics. Finishes may vary from aesthetic to special purposes. Examples of chemical finishes are:
Fabric softeners impart soft hand feel to the treated fabrics.
Silk surfacing a surface finishing of cotton to obtain an appearance similar to silk.
Plissé is chemical finish in which the fabrics are treated with sodium hydroxide to obtain a puckering effect.
Deweighting, or weight reduction, is a treatment for polyester to make it like silk. The treatment peels the surface and reduces the fiber weight and strength while making them softer and finer. Additionally, the treatment enhances the absorbency of the treated substrates.
Purpose
Finishing makes the textiles attractive and more useful. The finishing process adds essential properties to the treated textiles and enhances the serviceability of the products.
Serviceability in textiles includes aesthetics, comfort, durability, care and protection attributes.
Performance chemical finishes
"Special purpose finishes" or ''performance finishes'' improve the performance of textiles for a specific end-use. Performance finishes are not a new concept; oilcloth is the first known coated fabric. Boiled linseed oil is used to make oilcloth. Boiled oils have been used from the year 200 AD. Performance finishing contributes to a variety of areas. The following are some examples of special-purpose finishes:
Flame retardant finishes based on inorganic, organophosphorus, halogenated organic and nitrogen-based compounds make the treated fabric fire retarding; i.e., the fabric inhibits or suppresses the combustion process to improve safety.
Durable water repellent finishes provide water repellancy to the treated fabrics.
Wrinkle-resistant fabrics are treated fabrics with wrinkle-free finishes.
In manufacturing of pristine clothes.
Self cleaning fabrics with lotus effect.
Medical textiles are endowed with protecting properties such as body fluid resistance and an antimicrobial surface for use in personal protective equipment including aprons, coverall and gowns for healthcare workers treating infectious diseases such as COVID-19.
Coated fabrics are used for transportation, industrial application, geotextile, and military use.
Application
Chemical finishes can be applied in three different ways: exhaust applications, coating, and padding.
Coating
The coating is an application of chemical substances on the surface of fabric that is to be made functional or decorative. Coating is attained by applying a thin layer of a functional chemical, compound, or polymer on the substrate's surface. Coatings use less material than other types of applications, such as exhaust or padding.
Nanomaterials
Advances in chemical finishes include application of nanomaterials.
Chemical hazards
Certain chemical finishes contain potential hazards to health and the environment. Perfluorinated acids are considered to be hazardous to human health by the US Environmental Protection Agency.
See also
Wet process engineering
Performance (textiles)
References
Textiles
Textile techniques
Textile chemistry
Textile treatments | Chemical finishing of textiles | [
"Chemistry"
] | 837 | [
"nan"
] |
68,314,588 | https://en.wikipedia.org/wiki/YSES%202%20b | YSES 2 b is an exoplanet orbiting the star YSES 2 (TYC 8984-2245-1) in the constellation of Musca. It was discovered through direct imaging by Bohn et al. in 2021. The planet is unusually far from its young host star.
Its year is 1176.5 Earth years, and its semi-major axis is 114 AU. Its mass is Jupiter masses, its radius is unknown, and its temperature is unknown.
YSES 2, the host star, is a young, Sun-like star. It is approximately 360 ly from Earth in Scorpius-Centaurus Association. Its age is 14 million years.
References
Gas giants
Exoplanets detected by direct imaging
Exoplanets discovered in 2021
Musca
Scorpius–Centaurus association | YSES 2 b | [
"Astronomy"
] | 170 | [
"Musca",
"Constellations"
] |
68,315,561 | https://en.wikipedia.org/wiki/List%20of%20alternative%20nonmetal%20classes | In chemistry, after nonmetallic elements such as silicon, chlorine, and helium are classed as either metalloids, halogens, or noble gases, the remaining unclassified nonmetallic elements are hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur and selenium.
The nonmetallic elements are sometimes instead divided into two to seven alternative classes or sets according to, for example, electronegativity; the relative homogeneity of the halogens; molecular structure; the peculiar nature of hydrogen; the corrosive nature of oxygen and the halogens; their respective groups; and variations thereupon.
Classification science
Classes provided an economy of description and are beneficial to structuring knowledge and understanding of science. The distinction between classes is not absolute. Boundary overlaps can occur as outlying elements in each class show or begin to show less-distinct, hybrid-like, or atypical properties. As expressed by Nelson:
"…care needs to be taken to remember that…[this classification scheme] is only an approximation, and can only be used as a rough guide to the properties of the elements. Provided that this is done, however, it constitutes a very useful classification, and although purists often despise it because of its approximate nature, the fact is that practising chemists make a great deal of use of it, if only subconsciously, in thinking of the chemistry of different elements."
Two classes
Rudakiya. The nonmetals are simply classified according to their inclination to form chemical compounds. The halogens are not distinguished.
Three classes
Wulfsberg. The nonmetals are divided based on a loose correlation between electronegativity and oxidizing power. Very electronegative nonmetals have electronegativity values over 2.8; electronegative nonmetals have values of 1.9 to 2.8.
Bettelheim et al. The nonmetals are distinguished based on the molecular structures of their most thermodynamically stable forms in ambient conditions. Polyatomic nonmetals form structures or molecules in which each atom has two or three nearest neighbours (carbon: Cx; phosphorus: P4; sulfur: S8; selenium: Sex); diatomic nonmetals form molecules in which each atom has one nearest neighbour (hydrogen: H2; nitrogen: N2; oxygen: O2; fluorine: F2; chlorine: Cl2; bromine: Br2; iodine: I2); and the monatomic noble gases exist as isolated atoms (helium, neon, argon, krypton, xenon, radon) with no fixed nearest neighbour. This gradual reduction in the number of nearest neighbours corresponds (approximately) to a reduction in metallic character. A similar progression is seem among the metals. Metallic bonding tends to involve close-packed centrosymmetric structures with a high number of nearest neighbours. Post-transition metals and metalloids, sandwiched between the true metals and the nonmetals, tend to have more complex structures with an intermediate number of nearest neighbours
Four classes
Field & Gray. Hydrogen is placed by itself on account of it being "so different from all other elements". The remaining nonmetals are divided into nonmetals, halogens, and noble gases, with the unnamed class being distinguished by including nonmetals with relatively strong interatomic bonding, and the metalloids being effectively treated as a third super-class alongside metals and nonmetals.
Dinwiddle. A variant of Field & Gray in which carbon, nitrogen, oxygen, phosphorus, sulfur, and selenium are classified as carbon and other nonmetals.
Vernon. The nonmetals are divided into four classes that complement a four-fold division of the metals, with the noble metals treated as a subset of the transition metals. The metalloids are treated as chemically weak nonmetals, in a manner analogous to their chemically weak frontier metal counterparts.
Five classes
Dupasquier. Noble gases were not known in 1844 when this classification arrangement was published. Hydrogen, carbon, nitrogen and oxygen were grouped together on account of their occurrence in living things. Phosphorus, sulfur and selenium were characterised as being solid; volatile at an average temperature between 100 degrees and red heat; and combustible and flammable.
Myers et al. Metalloids are labeled as semiconductors and carbon, nitrogen, oxygen, phosphorus, sulfur, selenium as other nonmetals.
Dingle. Hydrogen is again placed by itself on account of its uniqueness. The remaining nonmetals are divided into metalloids, nonmetals, (referred to as "quintessential nonmetals"), halogens, and noble gases. Since the metalloids abut the post-transition or "poor" metals, they might be renamed as "poor non-metals".
Six or seven classes
Generic. After the relevant nonmetals are classified as either noble gases or halogens, the remainder are considered on a group-by-group basis. This results in six or seven sets of nonmetals, depending on the treatment of boron, which in some cases is regarded as a metalloid. The size of the group 14 set, and the sets of nonmetal pnictogens, chalcogens, and halogens will vary depending on how silicon, germanium, arsenic, antimony, selenium, tellurium, and astatine are treated. In some cases, the 2p nonmetals carbon, nitrogen, and oxygen, and other nonmetals are considered sufficiently different from their heavier congeners to warrant separate treatments.
Notes
References
Citations
Bibliography
Berkowitz J 2012, The stardust revolution: The new story of our origin in the stars, Prometheus Books, Amherst, New York,
Bettelheim FA, Brown WH, Campbell MK, Farrell SO 2010, Introduction to general, organic, and biochemistry, 9th ed., Brooks/Cole, Belmont California,
Catling DC 2013, Astrobiology: A very short introduction, Oxford University Press, Oxford,
Challoner J 2014, The elements: The new guide to the building blocks of our universe, Carlton Publishing Group,
Crawford FH 1968, Introduction to the science of physics, Harcourt, Brace & World, New York
Cressey 2010, "Chemists re-define hydrogen bond", Nature newsblog, accessed 23 August 2017
Cronyn MW 2003, "The prope
Dingle A 2017, The elements: An encyclopedic tour of the periodic table, Quad Books, Brighton,
Dinwiddle R, Lamb H, Franceschetti DR & Viney M (eds) 2018, How science works, Dorling Kindersley, London
Dupasquier A 1844, Traité élémentaire de chimie industrielle, Charles Savy Juene, Lyon
Field SQ & Gray T 2011, Theodore Gray's elements vault, Black Dog & Leventhal Publishers, New York,
Gargaud M, Barbier B, Martin H & Reisse J (eds) 2006, Lectures in astrobiology, vol. 1, part 1: The early Earth and other cosmic habitats for life, Springer, Berlin,
Government of Canada 2015, Periodic table of the elements, accessed 30 August 2015
Ivanenko NB, Ganeev AA, Solovyev ND & Moskvin LN 2011, "Determination of trace elements in biological fluids", Journal of Analytical Chemistry, vol. 66, no. 9, pp. 784–799 (784),
Jones BW 2010, Pluto: Sentinel of the Outer Solar System, Cambridge University, Cambridge,
Jorgensen CK 2012, Oxidation numbers and oxidation states, Springer-Verlag, Berlin,
Myers RT, Oldham KB & Tocci S 2004, Holt Chemistry, teacher ed., Holt, Rinehart & Winston, Orlando,
Nelson PG 2011, Introduction to Inorganic Chemistry: Key Ideas and their Experimental Basis, Ventus Publishing ApS
Rudakiya DM & Patel Y, "Bioremediation of metals, metalloids, and nonmetals", in Panpatte DG & Jhala YK (eds), in Microbial Rejuvenation of Polluted Environment, vol. 2, Springer Nature, Singapore, pp. 33–50,
Vernon RE 2020, "Organising the metals and nonmetals," Foundations of Chemistry, pp. 1−17, (open access)
Wang et al. 2020, "Understanding the uniqueness of the 2p-elements in the Periodic Table," Chemistry - A European Journal, vol. 26, no. 67,
Metalloids
Halogens
Noble gases | List of alternative nonmetal classes | [
"Materials_science"
] | 1,797 | [
"Noble gases",
"Nonmetals"
] |
68,315,701 | https://en.wikipedia.org/wiki/Aba%C3%A1 | An abaá or abahá (from the Fang language, abáá 'house of the word') is a longhouse located in cities and towns of Equatorial Guinea, especially those of the Fang ethnic group. The abaá has an official, religious and leisure function; In it, activities of all kinds are carried out, cooking, celebrating and men meet to make relevant decisions for the entire community. It is considered a symbolic place of unity and solidarity, and the supreme traditional head of the abaá is called "abbá".
Formerly, in the center of the house a sacred column, decorated with reliefs called àbòm-àbàà, used to be placed. The abaá was located at both ends of the town to act as a guard house; the alarm was raised with a drum (hollow trunk) called 'nkúú that according to the rhythm of the touches could communicate complex messages, and could even be heard from neighboring towns, transmitting information from one side of the valley to the other. Today, these practices are less and less common, and the abaá is built in the center of the town. The construction and maintenance of the abaá are also done in common.
The Fang, also called Betí, Pahouin, Pangwe or Pamue, are one of the majority ethnic groups in the country. Fang women are not allowed to enter the abaá, unless they serve food or testify in litigation.
The word "abaá" is one of the thirty of Equatorial Guinean origin in the Dictionary of the Royal Spanish Academy. They were incorporated into it in 2013, which defines the abaá as a "communal house". The other ethnic groups in the country have equivalent communal centers. They are known as mwebe in Ndowé, mpa in Bisío, riebapuá or wedja bohôté in Bubi and vidyil in Fá d'Ambó. In Spanish it is frequently called "House of the Word", a name that spread during colonial times.
References
Culture of Equatorial Guinea
Houses
Indigenous architecture
Vernacular architecture
Wooden buildings and structures | Abaá | [
"Technology"
] | 424 | [
"Structural system",
"Houses"
] |
68,319,397 | https://en.wikipedia.org/wiki/Social%20audio | Social audio is a subclass of social media that designates social media platforms that use audio as their primary channel of communication. This can include text messages, podcasts, tools for recording and editing audio in addition to virtual audio rooms. Still in an evolutionary state, different companies that develop social audio products are still trying to figure out what works for their users, and what doesn't.
History
In March 2020, Alpha Exploration Co. launched a social audio application called Clubhouse on the iOS platform. The app has led to the emergence of a new social media segment known as social audio. Soon realizing the potential of this segment, a handful of companies came out with their social audio solutions as standalone products or as an expansion to their current products. Clubhouse being the pioneer in this segment, all competitors eventually adapted its features to their products.
In October 2020, Betty Labs launched their social audio app Locker Room for iOS.
In November 2020, Twitter announced that it would develop a social audio feature on its platform.
In December 2020, Telegram introduced the social audio feature Voice Chats in its app. In the month, Twitter began beta testing its social audio feature known as Spaces with iOS users on their platform.
In February 2021, Facebook announced plans to add social audio functionality to its app.
In March 2021, Twitter has started beta testing Spaces with Android users on their platform. In that month, The Telegram released Voice Chat 2.0. On March 26, 2021, Slack CEO Stewart Butterfield was in a Clubhouse session moderated by PressClub when he announced that Slack would soon roll out a social audio feature. Late that month, Spotify purchased Betty Labs and announced its intention to rename the Locker Room app. On March 31, 2021, Discord introduced its social audio feature called Stage Channels.
In April 2021, The Facebook NPE team launched a social audio product called Hotline in closed beta, requiring a Twitter account to login. In the month, Reddit announced a social audio feature called Reddit Talk for their subreddit communities.
On May 3, 2021, Twitter Spaces released globally. On May 9, 2021, Clubhouse has launched a beta version of the Android app for users in the US, with worldwide access scheduled for a later date. Later, on May 21, 2021, Clubhouse became available worldwide for Android users.
On June 16, 2021, Spotify released its social audio app Spotify Greenroom on Android (early access) and iOS. On June 21, 2021, Facebook has released its social audio feature known as Live Audio Rooms to users based in the United States. The company said it would deploy the feature globally in the coming months. On June 30, 2021, Slack started rolling out its social audio solution named Slack Huddles for paid customers.
On July 21, 2021, Clubhouse app released its first gold build.
Common features
Chat rooms in which users can converse through shared audio recordings, typically in real-time.
Traditional text and rich-media-based chat.
List of platforms
Sound Branch
In 2016, Sean Gilligan launched the social audio application Sound Branch. The app supports various platforms, including the web, iOS, Android, Alexa, and Google Assistant, making it accessible for users worldwide. Sound Branch allows users to create and share short audio clips, fostering community interaction through voice. It is available globally at soundbranch.com and for private sites at soundbran.ch.
Sound Branch aims to revolutionize social audio by integrating voice technology into everyday communication, making it easier for users to connect and share experiences through sound.
Telegram Voice Chats
In December 2020, Telegram introduced the social audio feature Voice Chats in its app. Later, In March 2021, Telegram released Voice Chat 2.0. It allows unlimited participants and conversation recording.
Discord Stages
On March 31, 2021, Discord introduced its social audio feature called Stage Channels.
Facebook Live Audio Rooms and Podcasts
In April 2021, The Facebook NPE team launched a product called Hotline in closed beta, requiring a Twitter account to login. It offers a room where only some people can speak while others listen. Also, speakers can turn on video.
On June 21, 2021, Facebook has released its social audio feature known as Live Audio Rooms and Podcasts to users based in the United States. The company said it would deploy the feature globally in the coming months. It enables users to participate in the rooms with a maximum of 51 people (1 host and 50 speakers) onstage and an unlimited number of listeners. Also, provide access to a podcast library for its users.
Reddit Talk
In April 2021, Reddit announced a social audio feature called Reddit Talk for their subreddit communities.
Twitter Spaces
On May 3, 2021, Twitter added a social audio feature named Spaces to its platform. It allows users to engage in rooms with a maximum of 13 people (1 host, 2 co-hosts, and 10 speakers) onstage and an unlimited number of listeners.
Spaces is much further ahead in development than Clubhouse, with integration into the Twitter API that enables app integration. In July 2021, Twitter announced a 'Voice Transformer' feature that would work in Spaces to change your voice. Twitter also poached Clubhouse's exclusive NFL deal with 20 official NFL Spaces scheduled for the 2021-22 season.
Spotify Greenroom
On June 16, 2021, Spotify released its social audio app Spotify Greenroom. Greenroom has built-in recording and integrates into both Spotify and Anchor.fm. This integration allows podcasters to record rooms and upload directly to podcast for distribution. It also notifies Spotify listeners when a verified artist is live in Greenroom.
Greenroom can currently accommodate up to 1000 people in a room.
Slack Huddles
On June 30, 2021, Slack started rolling out its social audio solution named Slack Huddles for paid customers. It can take up to 50 participants at a time.
References
Collaborative projects
Social networks | Social audio | [
"Technology"
] | 1,199 | [
"Computing and society",
"Social media"
] |
68,319,645 | https://en.wikipedia.org/wiki/NGC%203605 | NGC 3605 is an elliptical galaxy located in the constellation Leo. It was discovered on March 14, 1784, by the astronomer William Herschel.
A relatively low-mass galaxy, it is a member of the Leo II Group of galaxies, including NGC 3607 among others.
References
External links
Leo (constellation)
3605
Elliptical galaxies
034415 | NGC 3605 | [
"Astronomy"
] | 71 | [
"Leo (constellation)",
"Constellations"
] |
68,319,760 | https://en.wikipedia.org/wiki/Regeln%20f%C3%BCr%20die%20alphabetische%20Katalogisierung | The or RAK (also known as , translating as: Rules for alphabetical cataloging) are a bibliographic cataloging set of rules. The RAK rules appeared for the first time in 1976 and became the dominant set of rules in Germany and Austria in the 1980s.
The theoretical model on which the RAK rules were based on are the "Paris Principles" (PP), drawn up in 1961 at a conference of the International Federation of Library Associations and Institutions (IFLA). The International Standard Bibliographic Description (ISBD), which has existed since 1971, formed the further basis for the RAK.
Like their counterpart from the English-speaking world, the Anglo-American Cataloging Rules (AACR), the RAK rules are very complex and, despite their suitability for creating electronic library catalogs, they are still strongly oriented towards card catalogs. Forms of headings in the original language of the medium to be cataloged and a priority of purely formal decision-making criteria, for example when a corporation is chosen as the main entry, are characteristic for RAK.
Since 2015, the RAK is being replaced by the international Resource Description and Access (RDA) set of rules.
History
The first edition of the RAK appeared in 1976 in the German Democratic Republic (GDR/DDR) and a year later in the Federal Republic of Germany (FRG/BRD). They formed the long-awaited replacement of the outdated (PI) (English: Prussian instructions), introduced in 1899 and expanded by DIN 1505 in 1932.
The development of a fundamentally renewed revision called RAK2 was discontinued in the course of the discussion about switching to AACR2. The successor to AACR2 is the Resource Description and Access (RDA) set of rules.
The RAK family of rules
Originally there was only one uniform RAK edition with alternative regulations for different requirements or library types. Due to the different requirements, the alternative regulations were recorded in different sets of rules for scientific libraries (RAK-WB) and public libraries (RAK-ÖB), and further regulation works for special types of media were developed:
The (RAK-WB) (English: Rules for Alphabetical Cataloging in Scientific Libraries) apply to scientific libraries and were published in 1983. The second edition from 1994 was updated in 1995, 1996, 1998 and 2002 through add-on deliveries. The current version dates from 2006 and will no longer be updated in view of the imminent replacement of the RAK by RDA. From 1993, the RAK-WB appeared as loose-leaf edition.
The (RAK-ÖB) (English: Rules for Alphabetical Cataloging in Public Libraries) are used in public libraries.
Various special regulations have been drawn up for certain forms of media:
The (RAK-Musik) (English: Rules for the alphabetical cataloging of editions of musical works) in a revised edition from 2003 apply to music (printed music, music sound carriers, etc.).
For media which are not books (images, sound media, microforms, etc.), the (RAK-NBM) (English: Rules for the alphabetical cataloging of non-book materials) apply. The last update of the loose-leaf edition took place in 2006.
(English: RAK maps), published in 1987, are used for cartographic materials (maps, aerial photographs, plans, etc.).
DIN standards
The formal cataloging rules are specified in DIN 1505:
— withdrawn in 2007 without replacement
— replaced 2013 by ISO 690
— withdrawn without replacement
References
Further reading
(12 pages)
(NB. Letter to the editor Willi Bredemeier on review of book "Rote Bibliotheken" by Hans-Peter Müller in Open Password #724 (2020-03-19), #727 (2020-03-26), #731 (2020-03-31).)
External links
http://d-nb.info/986402338/34 RAK-WB
Archival science
Metadata
Metadata standards
Library cataloging and classification | Regeln für die alphabetische Katalogisierung | [
"Technology"
] | 845 | [
"Metadata",
"Data"
] |
68,322,445 | https://en.wikipedia.org/wiki/Schlagwortkatalog | or SWK (English: Keyword catalog) is a German word for a library catalog that lists the publications according to descriptor keywords and thus allows selective thematic searches for literature. A keyword is understood to be a natural language expression that reproduces the content of the publication as briefly but precisely as possible. Complex content can be described using a syntactical keyword chain, a combination of several individual keywords (example: Uganda / child / soldier / experience report). The sub-keywords are not only used for targeted research, but also allow catalog users to see whether the document found is relevant to their search. While earlier keyword catalogs were kept as an independent card catalog, the search option for keywords is integrated in modern OPACs.
Rules for keyword cataloging
The (English: Rules for subject headings cataloging) (RSWK), up to the third edition in 2016 still called (English: Rules for the subject headings catalog), are used in universal academic libraries and public libraries, and with restrictions also in special libraries in Germany, Austria, and in German-speaking parts of Switzerland and Italy (South Tyrol) for verbal subject cataloguing of bibliographical contents. In addition, there is an index of the keywords available, the (SWD), which has been incorporated into the (GND) in 2012.
See also
Documentation
Subject indexing (keywording)
Authority file
Systematics
MAB-SWD
References
Further reading
Metadata
Library cataloging and classification
Library catalogues | Schlagwortkatalog | [
"Technology"
] | 315 | [
"Metadata",
"Data"
] |
66,888,952 | https://en.wikipedia.org/wiki/Chemical%20sensor%20array | A chemical sensor array is a sensor architecture with multiple sensor components that create a pattern for analyte detection from the additive responses of individual sensor components. There exist several types of chemical sensor arrays including electronic, optical, acoustic wave, and potentiometric devices. These chemical sensor arrays can employ multiple sensor types that are cross-reactive or tuned to sense specific analytes.
Overview
Definition
Sensor array components are individual sensors, which are selected based on their individual sensing properties (ie. method of detection, specificity for a particular class of analyte and molecular interaction). Sensor components are chosen to respond to as many analytes as possible; so, while the sensitivity and selectivity of individual sensor components vary, the sensors have an additive effect by creating a nonselective fingerprint for a particular analyte when combined into an array architecture. Recognition of fingerprints enables detection of analytes in mixtures. Chemical sensor arrays differ from other multianalyte tests such as a urinalysis stick assay which utilizes multiple, specific sensor materials for targeted detection of analytes in a mixture; instead, chemical sensor arrays rely on cross-reactivity of individual sensor components to generate fingerprints based on the additive responses of sensor components to the target analyte.
Comparison to other chemical sensors
Single sensor devices sense target analytes based on physical, optical, and electronic properties. Some sensors contain specific molecular targets to afford strong and specific binding with a particular analyte; however, while this approach is specific, complex mixture impact sensor performance. Several of these complex mixtures include odors and vapors exhaled from the lungs. Individual chemical sensors often utilize controlled sensing environments, and variations in ambient conditions (e.g., temperature and humidity) can interfere with sensor performance. Chemical sensor arrays employ pattern recognition of combinatorial responses of cross-reactive sensor components to enable sensing of a diverse array of mixtures in a variety of conditions. Chemical sensor arrays are often noted as mimicking the five senses—audition, gustation, olfaction, somatosensation, and vision—because the combinatorial responses to the different array components of a particular analytes create fingerprints for specific analytes or mixtures using both targeted molecular interactions and pattern recognition.
History
The history of chemical sensor arrays is closely linked with the development of other chemical sensor technologies, with research in the area of electronic chemical sensors picking up in the 1960s with the demonstration of metal-oxide semiconductor sensors capable of sensing analyses such as oxygen. Humans are capable of identifying and discerning between an estimated 10,000 scents or more, while only possessing 400 olfactory receptors. Signal processing in the brain of individual array component responses of olfactory receptors results in pattern recognition for discrimination of a particular scent. One of the design aims of many chemical sensor arrays is to mimic the performance of olfaction to design an electronic nose integrated with a variety of materials. Combining chemical sensor arrays with pattern recognition methods mimics biological sensory recognition methods. See Figure 1. Commercially available electronic nose systems exist and are used in the food industry for quality control. Current research efforts demonstrate the introduction of the electronic nose principle into environmental monitoring and medicine both as commercial instruments as well as in consumer-grade wearable electronic devices. At the center of chemical sensor arrays is the principle that different analytes will interact differently with a variety of materials. As such, any sort of material may be used in a sensor array, so long as it responds differently to different analytes or mixtures. From this idea, cross-reactive sensor arrays have been the focus of chemical sensor array development for their broad compatibility with the compounds as components of mixtures.
Array signal processing
The signal(s) coming from an array sensor must be processed and compared with already-known patterns. Many techniques are useful in processing array data including principal component analysis (PCA), least square analysis, and more recently training of neural networks and utilization of machine learning for pattern development and identification. Machine learning has been a more recent development for generation and recognition of patterns for chemical sensor array data. The method of data analysis chosen depends on a variety of factors including sensing parameters, desired use of the information (quantitative or qualitative), and the method of detection which can be classified under four major types of chemical sensor array: electronic, optical, acoustic wave, and electrochemical sensor arrays.
Electronic chemical sensor arrays
The first type of chemical sensor array relies on modulation of an electronic signal for signal acquisition. This type of chemical sensor array often utilizes a semiconductive material such as metal-oxide semiconductors, conductive polymers, nanomaterials, or framework materials such as metal-organic and covalent-organic frameworks. One of the simplest device architectures for an electronic chemical sensor is a chemiresistor, and other architectures include capacitors and transistors; these materials have a resistance which can be altered through physisorption or chemisorption of target molecules and thus a measurable signal as a change in electrical current, capacitance, or voltage.
Metal-oxide semiconductors in electronic chemical sensor arrays
Metal-oxide semiconductors were first reported in the 1960s as a chemiresistor sensor for single-analyte detection of organic vapors. The first commercially available chemiresistive sensors utilized metal-oxide semiconductors for the detection of carbon monoxide. Although most known for their use in carbon monoxide detectors, metal-oxide semiconductors are capable of sensing other analytes through strategic tuning of their composition. The high operating temperature required to operate these sensors make these semiconductors inefficient and cross-reactive particularly with water.
In the 1990s, several researchers at the University of Warwick created the first cross-reactive (non-selective) metal-oxide semiconductor sensor array integrated with pattern recognition software for sensing and distinguishing organic vapors, including acetone, ethanol, methanol, and xylene, in multianalyte mixtures. This electronic nose system was known as the Warwick Nose, and combined commercially available tin- and silicon-oxide semiconductors into an array format for gas sensing, see Figure 2. Current efforts are advancing the format of metal-oxide semiconductor arrays using microfabrication techniques to enable smaller array designs and integration of signal processing components into each array component. These microdevices have shown promise with lowered limits of detection and enhanced ability to distinguish volatile organic compounds and carbon monoxide with arrays containing different numbers of device, and these systems also reduce the amount of sensor material with thin films of metal-oxides. Sensitivity of sensors has also been shown to be influenced by changing the ratio of the metal within each device and data processing utilized least square analysis.
Another example of metal-oxide semiconductors is arrays of metal-oxide semiconductor field effect transistors (MOSFET), which consist of a catalytically active gate metal (such as palladium) over a silicon dioxide layer on a p-type silicon base with n-doped channels adjacent to the gate, and they have been used to sense hydrogen, ammonia, and ethanol. These MOSFETs through adsorbed-analyte modulating the semiconductor gate work function, which causes changes in voltage across the device. MOSFETs are highly tunable but remain limited by their cross-reactivity, and high operating temperatures.
Intrinsically conductive polymers in electronic chemical sensor arrays
Several intrinsically conductive polymers of interest include polyacetylene, polythiophene, and polyaniline, and others may be made conductive through processes including chemical doping. The principle chemistry underlying the electronic sensing mechanism of conductive polymers is modulation of the conductivity of these polymers upon changes to their physical structure (swelling) resulting from interactions with analytes (mainly through absorption). An advantage of using conductive polymers in sensor arrays is that there is synthetic access of a vast library of polymers. As a result, conductive polymers are a promising alternative to metal-oxide semiconductors because a greater number of sensors with different functionalities may be used to design a more robust array tailored for specific applications. Monomer identity, polymerization conditions, and device fabrication methods impact both the morphological and chemical properties of conductive polymers, which also contributes to the greater variety of possible array components which may be designed. The limitations of conductive polymer arrays are similar to those of single sensor analogs in that the signal transduction pathways through the polymer material are poorly understood and both struggle to sense non-polar species due to minimal adsorption to the polymer. Several commercially available systems are available and are used in food analysis and sensing of volatile organic compounds; however, progress to advance chemiresistive sensor arrays utilizing conductive polymers has decreased as other materials and sensing methods have been developed.
Nanomaterials in electronic chemical sensor arrays
Development of novel nanomaterials such as graphene, carbon nanotubes, and 2D and 3D framework materials have been reported as new classes of materials for applications in electronic chemical sensor arrays. For graphene and carbon nanotubes, surface functionalization via covalent or non-covalent modification, and edge site defects are utilized as sites for host-guest interactions. One such example is single-walled carbon nanotubes modified with various metalloporphyrins to enable discrimination of volatile organic compounds.
Conductive framework materials in electronic chemical sensor arrays
Conductive framework materials have similar mechanisms for sensing; however these materials may be designed with installed active sites tuned for a specific molecular interaction. Bimetallic metallophthalocyanine metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have shown promise in single device chemiresistors at sensing hydrogen sulfide, ammonia, and nitric oxide. The development of these materials as chemiresistors allows for strategic design of arrays capable of targeted molecular interactions, which can be employed to develop array components tailored to sensing specific compounds. Computational research of several MOFs has also focused on optimizing which combinations of MOFs are best suited for sensing particular components in various mixtures. The focus on curation of framework array components demonstrated the opportunity to design robust sensor arrays experimentally and computationally.
Mixed-material electronic chemical sensor arrays
Efforts have been made to overcome the specific limitations of different classes of materials suited for use in electronic chemical sensor arrays by combining sensors fabricated with different materials into one array. One example of these is metal-oxide nanowires coated in thin films of MOFs, which have been reported to have enhanced sensing performance over sensors made with the individual materials. Carbon black-polymer blends have also shown enhanced analyte discrimination and array-element signals to afford enhanced detection of volatile organic compounds both across a variety of classes, as well as within the same class.
Molecularly imprinted polymers have also been integrated into array formats and shown utility as the imprinting process enables molecularly imprinted polymer arrays to be tailors to specific analytes.
Optical/colorimetric chemical sensor arrays
Separate from electronic chemical sensor arrays are optical chemical sensor arrays which probe chemical interactions between target analytes and a sensing material with light (ultraviolet, visible, infrared). Generally, optical sensors probe chemical interactions with light through a variety of quantifiable methods including absorbance, diffraction, fluorescence, refraction, and scattering. Generally, fluorescence sensors show greater sensitivity than other optical methods. Optical sensors consist of a light source, wavelength filter(s), a sample, and a detector, with variations in sensor design based on the method used. Similar to the electronic nose, optical chemical sensor arrays have been categorized under the umbrella topic of optoelectronic nose and similarly operate by developing fingerprints for specific compounds and using pattern recognition to identify those components in mixture. Figure 2. shows the principles underlying colorimetric and fluorometric sensor arrays. Chemical interactions with dyes result in changes to light being detected in an optical sensor.
Optical sensors require selective interaction with analytes and two components are required: a probe material, and a chromo- or fluorophore. Cross-reactive optical and fluorescence arrays require strategic consideration of molecular interactions between probes and analytes. Much like electrical chemical sensor arrays, optical chemical sensor arrays face challenges in sensing in the presence of competing analytes such as water. Consideration of host-guest interactions allows an array to probe a variety of molecular features because integration of ‘promiscuous sensors’ (non-selective) such as optically active polymers permit non-discriminate sensing of a variety of compounds primarily based on hydrophobicity, and so-called ‘monogamous’ sensors with exclusive binding to a particular analyte (much like a lock-and-key design) will enhance specificity and applicability of a colorimetric sensor array. Regardless of the type of sensing probe, there are five major types of intermolecular interaction which lead to a measurable colorimetric change to a material.
Brønsted-Lowry acid-base interactions in colorimetric chemical sensor arrays
Brønsted-Lowry acid-base interactions such as those of dyes commonly used as pH indicators are one of the earliest methods for colorimetric sensing. Since the early 20th century, natural dyes such as 7-hydroxyohenoxazone (litmus) and anthocyanin oxonium dye have been used both as pH indicators and colorimetric sensors. Many other chromophores with Brønsted-Lowry acid-base functionality have been developed such azo dyes, nitrophenols, phthaleins, and sulfonphthaleins. The Brønsted-Lowry acid-base functionality of these chromophores relates to specific chemical moieties within their structures and their corresponding pKa. Color changes resulting from protonation/deprotonation events may be broadly defined as intermolecular interactions with an acid or base of a particular strength and/or concentration.
Lewis acid-base interactions in colorimetric chemical sensor arrays
While Brønsted-Lowry acid-base interactions are sensitive to a broad range of compounds, Lewis acid and base interactions comprise some of the most sensitive set of intermolecular interactions relevant to colorimetric chemical sensor arrays. The selectivity of Lewis acid and base interactions in chemical sensing are underscored by the fact that the most pungent of odors arise from Lewis bases (thiols, phosphines, amines) and the metal cation-containing olfactory receptors utilized to sense them at some of the lowest concentrations of all molecular motifs in biology use Lewis acid receptors. Lewis acid dyes (namely metals cations with an open-coordination site) are used in biological olfaction for sensing. As such, Lewis acids such as metalloporphyrins are of particular interest to researchers developing colorimetric sensor because of their strong Lewis acid-base interactions.
Other interactions in colorimetric chemical sensor arrays
File:Cyranose 320 Labelled.jpg
A variety of other reversible molecular interactions have been shown to produce color changes upon interaction with analytes. These include redox active chromo- and fluorophores which undergo specific color changes at different applied potentials. There also exists a variety of dyes such as merocyanine and azobenzene which show color changes based on the polarity of their environment. A‘push-pull’mechanism of electron density through these systems through intermolecular interactions results in augmentation of their dipole moments between ground and excited states, which manifests as observable changes to optical transition. Nanomaterials development has allowed for surface modification of certain dyes (especially redox active dyes) to afford high sensitivity due to larger surface area-to-volume ratio resulting for more active sites for analyte interaction with dyes.
Colorimetric chemical sensor array fabrication
Unlike the materials used in electronic chemical sensor arrays, in which direct interaction between the sensing material and an analyte leads to signal transduction as a change in conductivity or voltage, fabrication of colorimetric sensor arrays requires consideration of both analyte-substrate interaction and transduction of the optical signal. One method for colorimetric sensor array fabrication involves preparation of microspheres by suspending dyes into an inert, and transparent matrix. These microspheres are then incorporated into fiber optics. Other methods for fabricating colorimetric sensor arrays include printing of array fluor- and colorimetric dyes (either directly or in a nanoporous matrix) onto various substrates including paper, silica gel, or porous polymer membranes.
Inclusion of digital imaging and or illumination of optical chemical sensor array elements allows for rapid, real-time signal transduction of colorimetric data measurements in real-time of colorimetric and fluorescent data from microsphere or plated sensors. Detectors can process specific wavelengths of light, or employ RGB image processing programs to analyze data obtained from direct imaging of a sensor array. Much like electronic chemical sensor arrays, optical chemical sensor arrays are being miniaturized using microfabrication techniques to increase the applicability. Recent advancements in optical chemical sensor arrays have resulted in sensor arrays being directly integrated into flatbed scanners and mobile electronics such as smart phones (through microplate fabrication). These microplate arrays enable colorimetric analysis of complex mixtures in a variety of phases with applications in identification of toxic industrial chemicals using cross-reactive nanoporous pigments, cancer diagnosis using an array of gold nanoparticle-green fluorescent proteins, and development and assessment of combinatorial libraries of metal-dye complexes as sensors themselves.
Other types of chemical sensor arrays
Although less common, there are two other classifications of devices with demonstrated functionality as chemical sensor arrays. These include wave devices and electrochemical sensors.
Wave devices as chemical sensor arrays
There are several major types of wave devices including acoustic wave devices, thickness shear mode resonators (TSM), and quartz crystal microbalances. These devices oscillate at known frequencies and their frequencies of oscillation are modulated by changes in the mass of the device. These devices may be modified with the plurality of the materials already discussed as being useful materials in chemical sensor array. All of these materials are marked by the broad compatibility of their intermolecular interactions as well as selective interactions to a variety of compounds, which when combined together allow for fingerprint detection of compounds in mixtures.
Modification of wave devices with materials such as micromachined metal-oxide cantilevers coated in polymer films enable enhanced detection of mixtures of volatile organic compounds as well as hydrogen gas and mercury vapor. Bulk and surface acoustic wave devices have used in higher order sensors in which the sensing material gives rise to multiple modes for signal transduction, such as electrical and optical; additionally the same wave devices have also been used to create virtual chemical sensor arrays, in which data from one sensor component is further processed. A chemical sensor array of surface-modified quartz crystal microbalances with a variety of materials including copper phthalocyanine, single- and multi-walled carbon nanotubes was shown as a promising electronic nose for gas sensing when machine learning algorithms were employed for data processing.
Electrochemical sensor arrays
Another class of devices usable in chemical sensor arrays are electrodes. Commonly, electrochemical-based sensors are referred to as electronic tongues. Surface modification of an electrode in a multielectrode system allows for targeting of specific molecular interactions. Semipermeable membrane materials allows for electrodes to be made into sensors through their ability to selectively oxidize or reduce target analytes. One example includes, the use of an array of semipermeable membrane sensors made from potentiometric polymers like poly(vinyl chloride) have demonstrated their ability to monitor nitrate, nitrite, and ammonium concentrations in aqueous solution. Both voltametric and potentiometric methods have been developed, and this technique is an active area of research not only for multianalyte analysis of aqueous solutions such as cerebrospinal fluid, but also differentiation of redox products in electrochemical reactions.
Examples of chemical sensor arrays with real-world uses
There exists a diversity of well-understood, and emerging research focused on developing chemical sensor arrays for a variety of applications. Analytical devices integrated with a chemical sensor array have been proposed as diagnostic tests for cancer, bacterial infections based on fingerprint analysis of exhaled breath, as well as for food and product quality control. A few examples include:
Clinical trial of a chemical sensor array device made with gold nanoparticles linked with different organic ligands capable of detecting COVID-19 infections.
The WOLF eNose is a commercially available system of chemical sensor arrays using both electronic and colorimetric sensors for the detection of volatile organic compounds, and it has been employed for detection of urinary tract infection-causing bacteria.
The Cyranose 320 Electronic Nose is a commercially available chemical sensor array fabricated from 32 black carbon-polymer sensors capable of identifying six bacteria that cause eye infections with 96% accuracy, see Figure 4.
References
Sensors
Materials science
Arrays | Chemical sensor array | [
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66,891,425 | https://en.wikipedia.org/wiki/List%20of%20ZEE5%20original%20films | ZEE5 is an Indian on-demand Internet streaming media provider run by Zee Entertainment Enterprises. It was launched in India on 14 February 2018 with content in 12 languages. The service has distributed a number of original programs, including original series, specials, miniseries, documentaries and films.
Feature films
Zee Plex
On 2 October 2020, Zee launched a PVOD and Pay-per-view service called Zee Plex for its streaming service ZEE5, and various DTH services in India.
Indian
International
Short films
Footnotes
References
External links
Internet-related lists | List of ZEE5 original films | [
"Technology"
] | 111 | [
"Computing-related lists",
"Internet-related lists"
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66,893,619 | https://en.wikipedia.org/wiki/Vaccine-associated%20enhanced%20respiratory%20disease | Vaccine-associated enhanced respiratory disease (VAERD), or simply enhanced respiratory disease (ERD), is an adverse event where an exacerbated course of respiratory disease occurs with higher incidence in the vaccinated population than in the control group. It is a barrier against vaccine development that can lead to its failure.
Immunologically, VAERD is characterized with an exaggerated Th2 response and eosinophilic pulmonary infiltrations. It may result from antibody-mediated complement activation followed by weak neutralization.
Historical instances of the phenomenon were seen in vaccine candidates for respiratory syncytial virus (RSV), SARS-CoV, Middle East Respiratory Syndrome (MERS), and some influenza strains. Thus, COVID-19 vaccine clinical research involved monitoring for VAERD because the vaccine target, SARS-CoV-2, belongs to the same viral subfamily as SARS-CoV and MERS. The effect was not shown in phase III clinical trials for Tozinameran or for the Moderna vaccine.
References
Vaccination
Drug-induced diseases | Vaccine-associated enhanced respiratory disease | [
"Chemistry",
"Biology"
] | 225 | [
"Drug-induced diseases",
"Vaccination",
"Drug safety"
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66,895,075 | https://en.wikipedia.org/wiki/Pestov%E2%80%93Ionin%20theorem | The Pestov–Ionin theorem in the differential geometry of plane curves states that every simple closed curve of curvature at most one encloses a unit disk.
History and generalizations
Although a version of this was published for convex curves by Wilhelm Blaschke in 1916, it is named for and , who published a version of this theorem in 1959 for non-convex doubly differentiable () curves, the curves for which the curvature is well-defined at every point. The theorem has been generalized further, to curves of bounded average curvature (singly differentiable, and satisfying a Lipschitz condition on the derivative), and to curves of bounded convex curvature (each point of the curve touches a unit disk that, within some small neighborhood of the point, remains interior to the curve).
Applications
The theorem has been applied in algorithms for motion planning. In particular it has been used for finding Dubins paths, shortest routes for vehicles that can move only in a forwards direction and that can turn left or right with a bounded turning radius. It has also been used for planning the motion of the cutter in a milling machine for pocket machining, and in reconstructing curves from scattered data points.
References
Theorems in differential geometry
Theorems about circles
Theorems about curves
Curvature (mathematics) | Pestov–Ionin theorem | [
"Physics",
"Mathematics"
] | 263 | [
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66,895,257 | https://en.wikipedia.org/wiki/HD%20193322 | HD 193322 (HR 7767) is a group of six stars which appear to be at least loosely bound into a system in the constellation Cygnus. The stars comprise the core of the young open cluster Collinder 419 (Cr 419), which contains a total of 51 known stars. Another prominent member of the cluster is the eclipsing binary star (HD 228911). The cluster lies at a distance of about and its stars are only a few million years old.
System
HD 193322A
The brightest and most massive component, HD 193322A, is a triple star system and emits 89% of the system's visible light. It is composed of Aa and Ab on an eccentric 44-year orbit. The binary Ab itself consists of stars Ab1 and Ab2 on a orbit. The total mass of the system HD193233A has been calculated to be , although the individual stellar masses give a smaller total.
HD 193222Aa has spectral class O9Vnn, indicating a main-sequence star with highly-broadened absorption lines due to rapid rotation. HD 193322Ab1 has spectral class O8.5III, although its derived physical properties suggest it may actually be on the main sequence. Its companion HD 193322Ab2 is a main-sequence star of spectral class B2.5. The Ab pair may have a combined mass and brightness greater than Aa.
HD 193322B
HD 193322B is a single B-type main-sequence star separated from HD 193322A by 2.76 arcseconds on the sky, which puts them at least 2,780 astronomical units (AU) apart. Making several assumptions, the orbital period would be about 11 thousand years. HD 193322B produces 11% of the visible light emitted by the six-star system.
Other components
The components HD 193322C and HD 193322D are late B-class main sequence stars, respectively and from the central star. It is unclear if the two are gravitationally bound to the system. HD 193322D is a suspected Lambda Boötis star.
References
Cygnus (constellation)
Binary stars
B-type main-sequence stars
6
O-type main-sequence stars
7767
193322
100069
BD+40 4103
J20180697+4043554
O-type giants | HD 193322 | [
"Astronomy"
] | 482 | [
"Cygnus (constellation)",
"Constellations"
] |
66,896,520 | https://en.wikipedia.org/wiki/Gougerotin | Gougerotin is a water-soluble pyrimidine-based antibiotic which is produced by the bacteria Streptomyces graminearus and Streptomyces gougerotii. Gougerotin is named after the dermatologist Henri-Eugène Gougerot. Gougerotin has activity against Gram-positive and Gram-negative bacteria as well as against viruses.
References
Further reading
Gougerotin | Gougerotin | [
"Biology"
] | 90 | [
"Antibiotics",
"Biocides",
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66,900,050 | https://en.wikipedia.org/wiki/ALESS%20073.1 | ALESS 073.1 is an old spiral galaxy 12 billion light years away from Earth. The discovery was published in February 2021 in the journal Science. It has challenged the way astronomers understand galaxies and galaxy formation.
Observation
The galaxy was reported in a study conducted by a team of astronomers led by Dr. Federico Lelli at Cardiff University. The team used the Atacama Large Millimeter/submillimeter Array (ALMA) telescope, currently the largest radio telescope in the world, to observe the galaxy in its adolescence. The publication of the study of ALESS 073.1 includes “one of the sharpest, direct images of a primordial galaxy ever produced which allowed the team to undertake a detailed study of its internal structure," according to Cardiff University.
Distance
ALESS 073.1 is about 12 billion light years away from Earth. Due to its distance away from Earth, the light being shown is from when the universe was only 10% of its current age.
Characteristics
Like all galaxies, ALESS 073.1 is composed of gas, dark matter, and dust. It is made from stars that are held together by gravity.
ALESS 073.1 is estimated to have formed 12 billion years ago, just 1.2 billion years after the Big Bang. The image of the galaxy seen now gives an image of it during its early years. However, the physical characteristics of the galaxy indicate that the galaxy is much older than its features indicate. ALESS 073.1 exhibits features normally attributed to mature galaxies, such as spiral arms that extend from its center. In this way, it has similar features to spiral galaxies. It also has a rotating disk and a bulge, characteristics found in mature galaxies. This is contrary to the previous understanding of newer galaxies being chaotic, without a particular shape or structure. Over billions of years, young galaxies slow down and stabilize. This creates the distinctive features that are associated with mature galaxies.
The core of ALESS 073.1 hints at the presence of a supermassive black hole, since it is producing more energy than is typical for stars.
Scientific implications
The galaxy's young features, while displaying mature features, challenges scientists’ understanding of galaxy formation. However, more images and information are needed to indicate if this can be observed from other galaxies.
The massive bulge of ALESS 073.1 also puts features typically associated with mature galaxies into question. A bulge is a group of stars that are clustered together at the center of the galaxy. Bulges were generally thought to be a prominent feature of mature galaxies. It was thought that these bulges formed slowly over a long period of time through the merging of smaller galaxies. However, the discovery of ALESS 073.1's bulge indicates that they are able to be formed much quicker than previously thought. Approximately half of ALESS 073.1's stars were found to be present in the bulge.
References
Spiral galaxies
Fornax
Stellar evolution
Cardiff University
Black holes
Radio telescopes | ALESS 073.1 | [
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66,900,757 | https://en.wikipedia.org/wiki/Data%20collaboratives | Data collaboratives (sometimes called “corporate data philanthropy”) are a form of collaboration in which participants from different sectors—including private companies, research institutions, and government agencies—can exchange data and data expertise to help solve public problems.
Types
Data collaboratives can take many forms. They can be organized as:
Public Interfaces: Private firms publish select data assets to be public for use by external parties. Firms typically present this information as Application Programming Interfaces (APIs) or data platforms.
Trusted Intermediary: Private sector firms share data with partners from public, civil society actors, and academia. Data can be brokered by third parties, who provide valuable data under fixed terms and time limits to non-private organizations. It can also be run through third-party analytics, which shares data with data stewards to run analysis and share those findings with external actors, providing the outcomes of the data without exposing the sensitive information.
Data Pooling: Multi-sectoral stakeholders join “data pools” to share data resources. Public data pools allow partners to openly access and independently use the data, while private data pools limit access and contribution to the information.
Research and Analysis Partnership: Organizations share data and "proprietary data assets" with public and academic institutions to analyze and advance a public objective. Through these data transfers and data fellowships, access to and terms for use of data are highly controlled.
Prizes and Challenges: Organizations make data available to qualified applicants through competition for innovative use or platform design to add value to the firm. Open innovation competitions, like LinkedIn’s Economic Graph Challenge, allow for open and broader use of data by many independent users, while selective innovation challenges give limited data access, narrowing the scope of its application to a specific situation. Oftentimes, competition members are bound to data responsibility guidelines.
Intelligence Generation: Companies use data to build shareable tools and release them for public use. Although no formal, direct cross-sector sharing occurs, it lays the foundation for knowledge transfer and a culture of open, data-driven analysis.
Reasons for data collaboratives
The big data boom has demonstrated the power of data to inform and design public projects in an accountable and iterative manner. However, unequal access to certain data across sectors limits the ability of groups to find, access, or be made aware of valuable information, hindering social innovation. Data collaboratives create networks that bridge access and knowledge gaps by bringing different sectors together to share data to address social challenges.
The GovLab argues data collaboratives wherein a private sector data holder shares data with other groups tend to be motivated by a desire for:
Reciprocity: Sharing data with others can guide mutually beneficial business decisions.
Research and Insights: Sharing data can spark new and innovative approaches to issues.
Reputation and Public Relations: Sharing data, especially to advance public issues, can bolster the image and reputability of a firm, attracting new socially-conscious clients, talent, and followers.
Revenue Generation: Corporate data can be sold to data collaboratives, generating novel revenue streams.
Regulatory Compliance: Data collaboratives can help corporations advance transparency and trust by establishing and following data sharing protocols.
Responsibility and Corporate Philanthropy: Data collaboratives allow businesses to drive meaningful corporate social responsibility programs.
Data collaboratives can help respond to service delivery and emergency preparedness and disaster response problems. Robert Kirkpatrick, Director of UN Global Pulse noted that “the lack of innovation [in these sectors have] resulted in a failure to protect the public from what turns out to be preventable harms.”
Incentives for private sector participation
According to The GovLab, data collaboratives can provide five main benefits for public problems:
Situational awareness and response: recent, robust, and quality data from private or public sectors can help governments and civil society better mobilize in crisis and emergency situations. For instance, the Mobile Data, Environmental Extremes, and Population Project (MDEEP) is a collaboration between international organizations and telecommunications companies in Bangladesh to build “large-scale population displacement models to understand population movement related to natural disasters.”
Public service design and delivery: Access to previously inaccessible datasets can enable more accurate modelling of public service design and guide service delivery in a targeted, evidence-based manner. For example, collaborative use of datasets by governments, international organizations, aid groups, and private telecommunications carriers during the 2014 Ebola outbreak helped track and trace the virus.
Knowledge creation and transfer: Utilizing a larger number of and more diverse datasets can fill knowledge gaps to better respond to the problem at hand. The All of Us Research Program, created by the Obama administration in 2015, allows participants to share their health data to a secure system, which is then aggregated and anonymized for researchers to study and advance medical science.
Prediction and forecasting: Data from the past allows for informed prediction in the future, allowing groups to identify problems and respond more quickly. Leveraging search engine query data, researchers identified search terms, times, demographics that correlated with suicidal ideation across Indian youth.
Impact assessment and evaluation: Access to additional datasets can help organizations monitor and evaluate the effectiveness of policies and iteratively adapt programs for better service delivery. For example, the US Food and Drug Administration’s Sentinel Initiative used anonymized patient information sourced through the TriNetX Live USA Network to assess how many adults hospitalized for COVID-19 experienced or succumbed to thrombosis-related complications.
Examples
From 2017 to 2019, the percentage of companies entering data-related partnerships rose from 21% to 40%. A growing share of business competitors are also deciding to connect their data—jumping from 7% to 17%. In a 2019 report, the World Economic Forum and McKinsey estimated that connecting data across institutional and geographic boundaries could create roughly $3 trillion annually in economic value by 2020.
The following is an illustrative (but not exhaustive) list of some data collaboratives:
AI4BetterHearts: A global data cooperative established by the Novartis Foundation and Microsoft to improve cardiovascular health with the aim of using AI and data analytics to tackle heart disease.
The Chicago Data Collaborative: An effort by newsrooms, academics, and non-profit organizations to source data from public agencies, organize and document the data, and link it for a better and comprehensive understanding of the criminal justice system.
The Counter Trafficking Data Collaborative: A data collaborative working to curb human trafficking through data contributed by various countries and is maintained by the International Organization for Migration (IOM) and Polaris.
CubeIQ: An offline intelligence and measurement company helping marketers understand the true impact of their cross-channel advertising in the offline world. Their “Data For Good” program provides access to anonymous, privacy-compliant location data for academic research and humanitarian initiatives related to human mobility.
Data Collaborative for Justice: A project at the John Jay College that leverages community data to research the operations of the criminal justice system and create informed and transparent frameworks for criminal justice reform.
The Health Data Collaborative: A multi-agency, multilateral effort active in five African countries that provides a collaborative platform to leverage technical and financial resources at all levels alongside country-owned strategies and plans for collecting, storing, analyzing, and using data to improve health outcomes, with specific focus on UN SDG targets and communities that are left behind.
International Network for Data on Impact and Government Outcomes (INDIGO): An initiative of the Government Outcomes Lab (GO Lab) at the Blavatnik School of Government at the University of Oxford that builds an interdisciplinary network of data stewards to address social problems collaboratively.
InfoSum: A UK based company that enables a decentralized and trusted data ecosystem to enable companies to do more with customer data without actually sharing the data.
The Mobility Data Collaborative: A partnership among mobility operators, data aggregators, public agencies, academia and others to provide solutions and common framework to ensure safe, equitable and livable streets for all.
Water Data Collaborative: Works towards their mission to grow and maintain an inclusive community of water scientist data generators to provide data that enable the protection and restoration of our nation’s waterways.
Risks, challenges, and ethical considerations
Data collaboratives have significant challenges related to data security, data privacy, commercial risk, reputational concerns and regulatory uncertainty. In addition, there exist concerns about the lack of trust among individuals, institutions and governments.
Risks
Commercial Risks: “Corporations are concerned about brand reputation, data rights and the disclosure of proprietary or commercially sensitive information.”
Security Risks: Vulnerable data structures, lacking security expertise and processes can put all members of a data collaborative at risk.
Regulatory Risks: Fragmented legal and regulatory frameworks hinder data sharing across sectors and sovereign borders. Varying definitions of privacy and data holder rights exposes data holders to significant compliance risks and liabilities.
Privacy and Ethical Risks: Collaborative data use can expose individual identities, infringing on privacy and security. Additionally, protecting vulnerable populations from discrimination and human rights violations through the sharing of non-personal but demographically identifiable data is often a major issue.
Mitigating privacy protection issues
Privacy preserving computation (PPC) presents data in forms that can be shared, analyzed, and operated on by multiple stakeholders without the raw information. To do so, PPC seeks to control the environment within which the data is operated on (Trusted Execution Environment) and strips the data of identifying traits (Differential Privacy). Protecting the data via Homomorphic Encryption techniques, PPC allows users to execute operations and see their outcomes without exposing the source data. Through secure Multi-Party Computation, different groups can combine data to work in a decentralized and collaborative manner.
PPC techniques are already being leveraged by governments and large corporations. In 2015, the Estonian government worked with the private firm, Sharemind, to analyze tax and education records through Multi-Party Computation for the Private Statistics Project. An external audit by the European Commission PRACTICE project found that the Private Statistics Project did not expose any personal data.
In 2019, Google released its Private Join and Compute protocol to open-source, allowing users to use Homomorphic Encryption and Multi-Party Computation. In the same year, ten pharmaceutical companies formed the Melloddy consortium to use blockchain technology to train a drug discovery algorithm via shared data.
Mitigating power asymmetries
Power imbalances can occur when stronger parties manipulate, exclude, or pressure weaker members of the data collaborative. From a classical viewpoint, power refers to the influence a person or group has over another. Examining collaborative governance, Dave Egan, Evan E. Hjerpe, and Jesse Abrams suggest a three-phased approach to power: power over refers to the ability to control the behavior of others, power for looks at the ability to authorize the participation of stakeholders, and power to considers the ability to measure another entity’s ability to realize its goals.
Power imbalances can arise from disparities in authority, resources, legitimacy or trust between parties. The more actors in the data collaborative or more incentives of data use, the increased likelihood for conflicting interests. Oftentimes, data is viewed as an organizational asset, and opening it up to new uses by others means relinquishing control over the data and ceding this autonomy to the collaborative, resulting in the “control and generativity challenge.” Data stewards can help reduce the power imbalances by reducing bias influences, follow operating procedures, and provide issue resolution and remediation.
See also
Big Data
Data sharing
Open collaboration
Dispersed knowledge
Digital collaboration
Mass collaboration
Open innovation
References
External links
Data
Sharing
Data management
Data publishing
Open access (publishing)
Open data
Open science | Data collaboratives | [
"Technology"
] | 2,351 | [
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66,901,307 | https://en.wikipedia.org/wiki/RNA%20timestamp | An RNA timestamp is a technology that enables the age of any given RNA transcript to be inferred by exploiting RNA editing. In this technique, the RNA of interest is tagged to an adenosine rich reporter motif that consists of multiple MS2 binding sites. These MS2 binding sites recruit a complex composed of ADAR2 (adenosine deaminase acting on RNA catalytic 2 domain) and MCP (MS2 capsid protein). The binding of the ADAR2 enzyme to the RNA timestamp initiates the gradual conversion of adenosine to inosine molecules. Over time, these edits accumulate and are then read through RNA-seq. This technology allows us to glean cell-type specific temporal information associated with RNA-seq data, that until now, has not been accessible.
Background
The advent of RNA-sequencing (RNA-seq) in 2009 allowed for a deeper look into the biology of unique cell types by allowing researchers to examine the presence and quantity of RNA in a sample at any given time. The ability for analysis of the transcriptome has revealed valuable information about cellular differences and transcriptional changes between cell types. Further, RNA-seq has provided insights into examining alternative gene splicing, post-transcriptional modification and fusion genes – all of which would go undetected with genome analysis alone. The missing piece of the puzzle is understanding temporally when genes are expressed in a cell. RNA-seq requires the destruction of the cell, thus only revealing the transcriptome at a single moment. Understanding expression times and patterns of genes transcription would create a deeper understanding of the roles of genes and how regulation of expression timing could be affecting cellular processes and possible dysregulation could be contributing to disease development.
In recent years, there have been other technologies created with the end goal of determining the age of RNA transcripts within a given cell. For example, TimeLapse-seq, SLAM-seq as well as measuring RNA velocity which is the instantaneous change in cell state from unspliced transcripts. However, these methods were only able to reveal the age of transcripts at a fixed time point and failed to measure transcript age from more than one transcriptional pulse. While this information has importance, the ability to capture the dynamic transcriptional changes within a cell remained elusive.
The research groups of Edward Boyden at MIT and Fei Chen at Harvard, both in Cambridge, Massachusetts, U.S.A, developed RNA timestamps, a new (2020) method that allows the age chosen transcripts in a cell to be inferred. This technology provides the means to understand cellular biology at a new level and deepen our understanding of cellular processes and transcriptional regulation. Further, the use of RNA timestamps does not require lysis of the cell which is an undeniable advantage. This allows timestamps to have the unique availability to suggest information from multiple transcriptional pulses throughout the cellular development rather than being limited to a fixed time point.
Methods
A RNA timestamp is a repetitive reporter RNA motif that gradually undergoes adenosine to inosine (A-to-I) edits. RNA timestamps are specifically designed to be arrays of adenosine-rich sequences with MS2 binding sites, which are stem loops in the editing region of the timestamps. An RNA timestamp can be tagged to a RNA of interest, thus new RNA timestamps will be generated with transcriptional pulses of the gene of interest.
ADAR is an important enzyme in this technology as it edits adenosine to inosine (A-to-I). RNA timestamps use a genetically engineered version of this enzyme: ADAR2cd (human adenosine deaminase acting on RNA 2 catalytic domain). The ADAR2cd enzyme is targeted to specifically bind to MS2 sites, through fusion with the MS2 capsid protein (MCP). ADAR2cd thus binds to tagged RNA and causes A-to-I edits that accumulate over time. Adenosine is the main substrate of ADAR, so the adenosine rich sequences that flank the MS2 binding sites provide an excellent mechanism to facilitate A-to-I edits.
From here, high-throughput sequencing can be used to collect the information from the RNA timestamps. Sequencing will reveal A-to-I changes as adenosine-to-guanine mutations because inosine is non-conventional in RNA. This allows for temporal information about the RNA of interest to be incorporated into RNA-seq experiments.
Algorithmically, the age of the timestamped RNA can be inferred by estimating the total number of adenosine-to-inosine edits on the mRNA transcripts. This allows for inferall of transcript age with hour-scale accuracy.
Since multiple timestamped RNA transcripts are produced in the cells by a specific promoter, a transcriptional program was developed that uses a gradient descent algorithm to describe the number of timestamps generated as a function of time. This helps with determining the source of the time point for the RNA timestamps and the accuracy of the algorithm increased with the number of RNAs. Further, this reveals the time point at which the specific promoter was active.
RNA timestamp experiments were first experimentally validated in HEK293T cells that expressed the ADAR variant along with time stamped RNA under the control of tetracycline response element (TRE) induced by doxycycline. From these experiments, it was shown that the age of multiple RNA transcripts can be accurately determined (with a 95% confidence interval of 2.7±0.4h).
Applications
Current
As part of their proof of concept experiments, the researchers showed that timestamps can be used in primary hippocampal neuron cell culture to infer the c-fos response from KCl activation of neural activity.
This technology was also shown to have the potential to determine transcriptional events in individual cells. Timestamps can be read out when used in combination with high throughput single-cell droplet based methods thus allowing RNA timestamps to be used for applications like ordering of mRNAs based on the timing of transcriptional processes based on cell type, and determining whether a specific promoter was active.
Future
RNA timestamp technology provides a novel means to understand cellular transcription. Only a few months after this technology was described, Dr. Michael Gilhooey and colleagues in England discussed RNA timestamps as an interesting new perspective to apply to their research on inherited optic neuropathies. This suggests diverse potential applications of RNA timestamps, and perhaps it will be beneficial to better understanding transcriptional changes in human diseases, as alluded to by Dr. Gilhooey.
Further, the researchers suggested that perhaps timestamps could be calibrated to be used in in vivo experiments. The researchers have also suggested a potential mechanism using a virus to deliver the RNA reporter to target cells in vivo. This could provide a revolutionary mechanism to track expression dynamics during development or recording responses to stimuli in vivo. However, for now, timestamps are limited to in vitro experiments.
Limitations
Despite the many advantages of this method, there are some caveats of RNA timestamping worth mentioning:
Only RNAs that are tagged with the timestamps can be read through this technique
The timestamping technique would yield different results with RNAs having varying half lives. The researchers hope to create a mechanism in which faster editing could be possible: this would be beneficial for RNA with shorter half lives and improve the resolution to a time point more precise than hours
Genetic engineering is required to tag the promoter of interest
The researchers are unsure if the calibration in one system, for example cell culture, could be utilized to decode information obtained from other systems, like in vivo.
In more complex and slower transcriptional processes, the transcriptional programming algorithm would need thousands of timestamped RNAs to decode the original timepoints. This might prove to be laborious and expensive.
References
Gene expression
Genetic engineering
RNA | RNA timestamp | [
"Chemistry",
"Engineering",
"Biology"
] | 1,667 | [
"Biological engineering",
"Gene expression",
"Genetic engineering",
"Molecular genetics",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
66,901,729 | https://en.wikipedia.org/wiki/Iain%20Stewart%20%28physicist%29 | Iain William Stewart is a Canadian-American theoretical nuclear and particle physicist at the Massachusetts Institute of Technology, where he is the Otto and Jane Morningstar Professor of Science and the current Director of the MIT Center for Theoretical Physics (CTP). He is best known for his work on effective field theories and for developing the Soft Collinear Effective Theory (SCET).
Biography
Stewart attended college at the University of Manitoba, where he received his B.Sc. with Joint Honors in Physics and Mathematics and M.Sc. in Theoretical Physics in 1994 and 1995, respectively, and won the Governor General’s Silver Medal for highest standing in his graduating class. He wrote his master’s thesis under the supervision of Peter Blunden.
Stewart then moved to the California Institute of Technology for four years, earning his Ph.D. in Theoretical Physics in 1999 under the supervision of Mark Wise. He then held a postdoctoral position at the University of California, San Diego until 2002 and a research assistant professorship at the University of Washington, Seattle for a year, before moving to the MIT Department of Physics in 2003, where he earned tenure in 2009. He became director of the MIT Center for Theoretical Physics in 2019 and was promoted to a named professorship in 2021.
Research and teaching
Stewart “designs and applies effective field theories to describe physics at collider experiments and to explore the structure of quantum field theory.” Effective field theory is a technique used to circumvent the difficulty of carrying out calculations and approximations related to elementary particle physics, when the calculations involves working with quantities of vastly different magnitudes. Stewart is perhaps best known for developing the Soft Collinear Effective Theory (SCET) in the early 2000’s, which helps physicists analyze interactions between energetic quarks and gluons that are soft (low energy) or collinear (traveling in a similar direction).
He has also made major contributions to other areas of theoretical nuclear and particle physics, including the use of Euclidean distributions in lattice QCD, the use of SCET in collider physics and B physics, non-relativistic QED and QCD, and indirect detection methods for dark matter.
In addition to his research, Stewart engages in teaching and mentoring activities. He has supervised dozens of undergraduates, graduate students, and postdoctoral fellows, many of whom have gone on to faculty positions at universities and national labs. He developed a free online course on Effective Field Theory through the platform EdX, as well as a new MIT course, Classical Mechanics III. In 2015 MIT awarded him the Buechner Faculty Teaching Award.
Honors
Erwin Schrodinger Visiting Professor, University of Vienna, City of Vienna (2016)
MIT Buechner Faculty Teaching Award (2015)
Simons Investigator of the Simons Foundation (2014)
Fellow of the American Physical Society (2013)
Friedrich Wilhelm Bessel Research Award from the Humboldt Foundation (2008)
Sloan Fellowship (2004)
Outstanding Junior Investigator Award, US Department of Energy (2003)
Governor General's Silver Medal (1994)
References
MIT Center for Theoretical Physics faculty
Canadian physicists
Canadian emigrants to the United States
University of Manitoba alumni
California Institute of Technology alumni
University of California, San Diego people
University of Washington faculty
Fellows of the American Physical Society
Sloan Research Fellows
Theoretical physicists
Particle physicists
Nuclear physicists
21st-century American physicists
Year of birth missing (living people)
Living people | Iain Stewart (physicist) | [
"Physics"
] | 682 | [
"Theoretical physics",
"Particle physicists",
"Particle physics",
"Theoretical physicists"
] |
77,134,553 | https://en.wikipedia.org/wiki/VVD-118313 | VVD-118313 is a chemical compound which acts as a potent and selective negative allosteric modulator of JAK1, and was developed for research into the treatment of inflammatory diseases, especially chronic inflammation involved in the development of cancer.
See also
Deucravacitinib
References
Non-receptor tyrosine kinase inhibitors
Piperidines
Chloroarenes
Pyrrolidines
Sulfones
Carboxamides | VVD-118313 | [
"Chemistry"
] | 90 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Sulfones",
"Pharmacology stubs"
] |
77,134,850 | https://en.wikipedia.org/wiki/Brepocitinib | Brepocitinib (PF-06700841) is a drug which acts as a dual inhibitor of JAK1 and TYK2, and was developed for the treatment of plaque psoriasis.
See also
Deucravacitinib
Zasocitinib
References
Non-receptor tyrosine kinase inhibitors
Janus kinase inhibitors
Organofluorides
Cyclopropyl compounds
Pyrimidines
Pyrazoles
Secondary amines
Diazabicyclooctanes | Brepocitinib | [
"Chemistry"
] | 105 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,134,945 | https://en.wikipedia.org/wiki/Izencitinib | Izencitinib (TD-1473) is a drug which acts as a pan-Janus kinase inhibitor, binding with high affinity at all three subtypes JAK1, JAK2 and JAK3. It is taken orally and was developed to be gut selective with minimal absorption into the rest of the body, allowing targeting of inflammatory bowel disease but with reduced side effects compared to other similar drugs.
See also
Delgocitinib
Tofacitinib
References
Non-receptor tyrosine kinase inhibitors
Tropanes
Pyrazoles
Naphthyridines
Nitriles | Izencitinib | [
"Chemistry"
] | 125 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs",
"Nitriles"
] |
77,134,996 | https://en.wikipedia.org/wiki/Gusacitinib | Gusacitinib (ASN002) is an investigational drug which acts as a pan-Janus kinase inhibitor, binding with similar affinity at JAK1, JAK2, JAK3 and TYK2, and also inhibiting spleen tyrosine kinase (SYK). It is taken orally and was developed for the treatment of eczema and dermatitis.
See also
Delgocitinib
Izencitinib
Tofacitinib
References
Non-receptor tyrosine kinase inhibitors
Piperidines
Anilines
Nitriles
Pyrimidopiperidines | Gusacitinib | [
"Chemistry"
] | 127 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs",
"Nitriles"
] |
77,135,106 | https://en.wikipedia.org/wiki/Ropsacitinib | Ropsacitinib (PF-06826647) is a drug which is an orally active, selective tyrosine kinase 2 (TYK2) inhibitor. It has been researched for various autoimmune inflammatory conditions, primarily plaque psoriasis.
See also
Brepocitinib
Deucravacitinib
References
Tyrosine kinase inhibitors
Pyrazoles
Pyrazolopyrazines
Cyclobutanes
Nitriles | Ropsacitinib | [
"Chemistry"
] | 100 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs",
"Nitriles"
] |
77,135,154 | https://en.wikipedia.org/wiki/Zimlovisertib | Zimlovisertib (PF-06650833) is a drug which acts as a selective inhibitor of the enzyme Interleukin-1 receptor-associated kinase 4 (IRAK-4). It has antiinflammatory effects and has been trialed for various indications including hidradenitis suppurativa and treatment of COVID-19 infection, and while it has not been adopted into clinical use it continues to be used for research in this area.
See also
Emavusertib
References
Interleukin-1 receptor-associated kinase 4 inhibitors
Amides
Methoxy compounds
Pyrrolidones
Ethers
Organofluorides
Isoquinolines | Zimlovisertib | [
"Chemistry"
] | 147 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Ethers",
"Pharmacology stubs",
"Amides"
] |
77,135,221 | https://en.wikipedia.org/wiki/Emavusertib | Emavusertib (CA-4948) is a drug which acts as a selective inhibitor of the enzyme Interleukin-1 receptor-associated kinase 4 (IRAK-4) and was developed for the treatment of some forms of cancer.
See also
Zimlovisertib
References
Interleukin-1 receptor-associated kinase 4 inhibitors
Pyridines
Pyrrolidines
4-Morpholinyl compounds
Oxazoles
Carboxamides
Oxazolopyridines | Emavusertib | [
"Chemistry"
] | 104 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,135,692 | https://en.wikipedia.org/wiki/Hibernation%20factor | A hibernation factor is a protein used by cells to induce a dormant state by slowing or halting the cellular metabolism. This can occur during periods of stress, randomly in order to allocate "designated survivors" in a population, or when bacteria cease growth (enter stationary phase). Hibernation factors can do a variety of things, including dismantling cellular machinery and halting gene expression, but the most important hibernation factors bind to the ribosome and halt protein production, which consumes a large fraction of the energy in a cell.
Ribosome hibernation
Ribosome hibernation occurs when ribosome hibernation factors bind to the ribosome and halt protein production. Ribosome hibernation is almost ubiquitous in bacteria, as well as in the plastids of plants, and may also be present in eukaryotes. Ribosome hibernation factors can simply inactivate ribosomes (RaiA, Balon), link pairs into inactive dimers called 100S ribosomes (RMF and HPF), or interfere at various stages of the translation cycle (RsfS, YqjD, SRA, and EttA). One indicator of ribosome hibernation is the presence of a large number of 100S ribosomes, which can constitute up to 60% of the ribosomes in a cell at a time.
RMF, RaiA, and HPF
Three proteins, RMF, RaiA, and HPF, are only found in the large class of bacteria gammaproteobacteria. RMF (Ribosome modulation factor) is a small protein, typically produced under nutrient starvation and stress conditions, that is the main factor in the formation of 100S ribosomes. During the formation process, RMF binds together 70S (standard) ribosomes to form 90S ribosome dimers. These 90S dimers are converted by HPF (hibernation promoting factor) to form mature 100S dimers. A third protein, RaiA (ribosome-associated inhibitor A) is thought to both inactivate 70S ribosomes alone and stabilize them, preventing them from being converted into 100S ribosomes. Most non-gammaproteobacteria, as well as some plant plastids, instead contain a HPF homologue that can form 100S ribosomes by itself.
Balon
Balon (Spanish "ball", after homologue Pelota) is a hibernation factor protein found in the cold-adapted bacterium Psychrobacter urativorans. The protein was discovered accidentally by a researcher who unintentionally left a sample of P. urativorans in an ice bucket for too long, cold-shocking it, through subsequent cryo-EM scans of the organism's ribosomes. Unlike other factors, Balon can bind to the ribosome while protein production is in process. This is important for rapid response to stress because in some cells, protein production can take up to 20 minutes to complete. Balon does this by rather than physically blocking the A site of the ribosome, as other hibernation factors do, binding near to but not across the channel, allowing it to attach to the ribosome independent of whether protein production is taking place. Genetic relatives of Balon have been found in 20% of bacterial genomes catalogued in public databases, but are absent from Escherichia coli and Staphylococcus aureus, the most widely used models for cellular dormancy.
RsfS
RsfS (Ribosome silencing factor S) inhibits translation by preventing the 30S and 50S subunits of the ribosome from binding to each other again after they split during ribosome recycling. It has also been suggested to be a ribosome biogenesis factor rather than a hibernation factor.
SRA
SRA (Stationary-phase-induced Ribosome-Associated protein) is not well understood as of 2018. It is a small protein of 45 amino acids and is tightly associated with the 30S ribosomal subunit. It increases from an average of 0.1 molecules per ribosome to 0.4 per ribosome during the transition to stationary phase and remains so for several days.
YqjD
YqjD is an inner membrane protein specific to stationary phase. It binds to 70S and 100S ribosomes and has been proposed as of 2018 to mediate the localization (moving) of hibernating ribosomes to the cell membrane. While cells lacking YqjD do not have altered growth rates of ribosome composition, artificially high levels of it quickly halts growth depending on the protein's ribosome-binding capability.
EttA
EttA (Energy-dependent translational throttle A) is an ATP-binding protein of the ABC-F family which is thought to modulate translation rate based on the energy level of a cell. When ADP (degraded ATP, indicating low energy) levels are high, the protein inhibits ribosome activity, allowing translation at high ATP levels. EttA interferes specifically after the formation of the first peptide bond in the new protein and before the first translocation step induced by EF-G.
References
Molecular biology
Metabolism | Hibernation factor | [
"Chemistry",
"Biology"
] | 1,096 | [
"Biochemistry",
"Cellular processes",
"Metabolism",
"Molecular biology"
] |
77,137,103 | https://en.wikipedia.org/wiki/PKS%201148-001 | PKS 1148-001 also known as UM 458 and 4C -00.47, is a quasar located in the constellation of Virgo. Its redshift is 1.979, estimating the object to be located 10.2 billion light-years from Earth.
Using interplanetary scintillations and very-long-baseline interferometry it was determined that the radio source associated with the quasar has an apparent size of 0.1 arcseconds. A one-sided jet has been observed in the milliarcsecond scale. The most accepted theory for the creation of radio jets is the presence of a supermassive black hole which accretes material.
References
Quasars
4C objects
Blazars
Virgo (constellation)
Supermassive black holes
037034
Starburst galaxies
Active galaxies | PKS 1148-001 | [
"Physics",
"Astronomy"
] | 180 | [
"Black holes",
"Unsolved problems in physics",
"Supermassive black holes",
"Virgo (constellation)",
"Constellations"
] |
77,138,130 | https://en.wikipedia.org/wiki/Prince%20Chaldean | Prince Chaldean (also known as Chaldean 854 and Chaldean 637) is a Percheron gray stallion, known for his very long, abundant mane. Born in the Perche region of France in 1877, he was exported as a youngster to the United States, where he was briefly owned by Mark Wentworth Dunham, who sold him a few months later to Mr. Babcock in Wisconsin. Chaldean became a popular local breeding stallion.
He earned his nickname "Prince Chaldean" when he toured with the Ringling Brothers Circus from 1892 onwards. He was presented as the most beautiful and heaviest Percheron horse ever to arrive in the United States. One of his daughters, the mare Isis 1744, is the dam of three famous stallions, Primus 5705, Horus 6491, and Ilderim 10356.
History
Chaldean was born in 1877 in the department of Eure-et-Loir, France. He was imported as a young foal by the famous horse owner and breeder Mark Wentworth Dunham, to his stud in the town of Wayne, Illinois in the USA, the same year. His coat color was black.
Property of Babcock
In February 1878, it was acquired by a man named H. A. Babcock (according to the U.S. Register and the Breeder's Gazette), residing in Neenah, Wisconsin. However, author Jean-Léo Dugast attributes the name Geo Babcock to its owner, specifying that he resides in Appleton. Chaldean was bred from the age of 43. Babcock testified that his horse had "never been beaten in a show ring". By 1890, while still owned by Babcock, Chaldean's coat color had changed to gray.
Circus career
The stallion first took part in Ringling Brothers circus shows in 1892, which presented him as the heaviest and most handsome Percheron ever exported to the USA, under the name "Prince Chaldean, The Percheron Beauty ". Contextualizing all shows involving physically challenged circus animals, including the Ringling Brothers circus, skeptical investigator Joe Nickell notes that these animals were often integrated into sideshows (entresorts), shows presented separately from the main tent, based on capturing the audience's interest through bon mots. Numerous animals with physical peculiarities, including horses, were exhibited in the great American circus shows of the period.
Prince Chaldean, for example, was exhibited in Wisconsin in 1892. For the occasion, the Ringling Brothers circus distributed press releases to the local American press, promoting the horse's appearance; at the same time, it distributed another press release promoting "the biggest hippopotamus in the world".
Description
Chaldean is a Percheron horse. This stallion is best known for his very long, abundant mane. It reached a length of over 2.20 m (7 feet 4 inches) in 1890, according to its second owner Babcock. This feature was described in the Breeder's Gazette as "out of the ordinary". His mane was measured at 9 feet and two inches (2 meters and 80 centimeters) two years later, in 1892, his tail being the same length.
His weight exceeded 1,800 pounds (810 kg) in 1892.
He is registered as a black-coated horse in the Stud-book percheron, but the Breeder's Gazette and author Jean-Léo Dugast report, based on the study of iconographic documents, that he was more likely gray, his color having gradually changed after his birth.
Origins
There is disagreement about Chaldean's origins. The French Studbook (1883), the American Percheron Studbook (1888) and the Breeder's Gazette of 1890 all report him as the son of a stallion named Coco, himself a son of Coco II 714. This makes Chaldean a grandson of Coco II 714. Author Jean-Léo Dugast states that his father was the stallion Coco II 714.
His mother is a daughter of Superior 730.
The Ringling brothers describe him as a "noble" animal with an "impeccable pedigree".
Descent and homage
Chaldean is said to have been a very popular sire, producing between 75 and 90 foals a year. All his foals would be gray, whatever the color of the mom.
One of his daughters, registered in the American Percheron Studbook, is the mare Isis 1744, dam of Primus 5705, Horus 6491, and Ilderim 10356, the latter presented by H.C. Farnum and awarded third prize at the Detroit International Show in 1890.
In 1889, American illustrator Lou Burk drew Chaldean to illustrate the cover of an issue of the Breeder's Gazette, published on May 28, 1890. This illustration is described as being very accurate with the horse used as a model.
See also
Percheron
Draft horse
References
Bibliography
Individual horses
Circuses
Breeding | Prince Chaldean | [
"Biology"
] | 1,032 | [
"Behavior",
"Breeding",
"Reproduction"
] |
77,139,118 | https://en.wikipedia.org/wiki/Eleven-dimensional%20supergravity | In supersymmetry, eleven-dimensional supergravity is the theory of supergravity in the highest number of dimensions allowed for a supersymmetric theory. It contains a graviton, a gravitino, and a 3-form gauge field, with their interactions uniquely fixed by supersymmetry. Discovered in 1978 by Eugène Cremmer, Bernard Julia, and Joël Scherk, it quickly became a popular candidate for a theory of everything during the 1980s. However, interest in it soon faded due to numerous difficulties that arise when trying to construct physically realistic models. It came back to prominence in the mid-1990s when it was found to be the low energy limit of M-theory, making it crucial for understanding various aspects of string theory.
History
Supergravity was discovered in 1976 through the construction of pure four-dimensional supergravity with one gravitino. One important direction in the supergravity program was to try to construct four-dimensional supergravity since this was an attractive candidate for a theory of everything, stemming from the fact that it unifies particles of all physically admissible spins into a single multiplet. The theory may additionally be UV finite. Werner Nahm showed in 1978 that supersymmetry with spin less than or equal to two is only possible in eleven dimensions or lower. Motivated by this, eleven-dimensional supergravity was constructed by Eugène Cremmer, Bernard Julia, and Joël Scherk later the same year, with the aim of dimensionally reducing it to four dimensions to acquire the theory, which was done in 1979.
During the 1980s, 11D supergravity was of great interest in its own right as a possible fundamental theory of nature. This began in 1980 when Peter Freund and Mark Ruben showed that supergravity compactifies preferentially to four or seven dimensions when using a background where the field strength tensor is turned on. Additionally, Edward Witten argued in 1981 that eleven dimensions are also the minimum number of dimensions needed to acquire the Standard Model gauge group, assuming that this arises as subgroup of the isometry group of the compact manifold.
The main area of study was understanding how 11D supergravity compactifies down to four dimensions. While there are many ways to do this, depending on the choice of the compact manifold, the most popular one was using the 7-sphere. However, a number of problems were quickly identified with these approaches which eventually caused the program to be abandoned. One of the main issues was that many of the well-motivated manifolds could not yield the Standard Model gauge group. Another problem at the time was that standard Kaluza–Klein compactification made it hard to acquire chiral fermions needed to build the Standard Model. Additionally, these compactifications generally yielded very large negative cosmological constants which could be hard to remove. Lastly, quantizing the theory gave rise to quantum anomalies which were difficult to eliminate. Some of these problems can be overcome with more modern methods which were unknown at the time. For example, chiral fermions can be acquired by using singular manifolds, using noncompact manifolds, utilising the end-of-world 9-brane of the theory, or by exploiting string dualities that relate the 11D theory to chiral string theories. Similarly, the presence of branes can also be used to build larger gauge groups.
Due to these issues, 11D supergravity was abandoned in the late 1980s, although it remained an intriguing theory. Indeed, in 1988 Michael Green, John Schwartz, and Edward Witten wrote of it that
In 1995, Edward Witten discovered M-theory, whose low-energy limit is 11D supergravity, bringing the theory back into the forefront of physics and giving it an important place in string theory.
Theory
In supersymmetry, the maximum number of real supercharges that give supermultiplets containing particles of spin less than or equal to two, is 32. Supercharges with more components result in supermultiplets that necessarily include higher spin states, making such theories unphysical. Since supercharges are spinors, supersymmetry can only be realized in dimensions that admit spinoral representations with no more than 32 components, which only occurs in eleven or fewer dimensions.
Eleven-dimensional supergravity is uniquely fixed by supersymmetry, with its structure being relatively simple compared to supergravity theories in other dimensions. The only free parameter is the Planck mass, setting the scale of the theory. It has a single multiplet consisting of the graviton, a Majorana gravitino, and a 3-form gauge field. The necessity of the 3-form field is seen by noting that it provides the missing 84 bosonic degrees of freedom needed to complete the multiplet since the graviton has 44 degrees of freedom while the gravitino has 128.
Superalgebra
The maximally-extended algebra for supersymmetry in eleven dimensions is given by
where is the charge conjugation operator which ensures that the combination is either symmetric or antisymmetric. Since the anticommutator is symmetric, the only admissible entries on the right-hand side are those which are symmetric on their spinor indices, which in eleven dimensions only occurs for one, two, and five spacetime indices, with the rest being equivalent up to Poincaré duality. The corresponding coefficients and are known as quasi-central charges. They aren't regular central charges in the group theoretic sense since they are not Lorentz scalars and so do not commute with the Lorentz generators, but their interpretation is the same. They indicate that there are extended objects that preserve some amount of supersymmetry, these being the M2-brane and the M5-brane. Additionally, there is no R-symmetry group.
Supergravity action
The action for eleven-dimensional supergravity is given by
Here gravity is described using the vielbein formalism with an eleven-dimensional gravitational coupling constant and
The torsion-free connection is given by , while is the contorsion tensor. Meanwhile, is the covariant derivative with a spin connection , which acting on spinors takes the form
where . The regular gamma matrices satisfying the Dirac algebra are denote by , while are position-dependent fields. The first line in the action contains the covariantized kinetic terms given by the Einstein–Hilbert action, the Rarita–Schwinger equation, and the gauge kinetic action. The second line corresponds to cubic graviton-gauge field terms along with some quartic gravitino terms. The last line in the Lagrangian is a Chern–Simons term.
The supersymmetry transformation rules are given by
where is the supersymmetry Majorana gauge parameter. All hatted variables are supercovariant in the sense that they do not depend on the derivative of the supersymmetry parameter . The action is additionally invariant under parity, with the gauge field transforming as a pseudotensor . The equations of motion for this supergravity also have a rigid symmetry known as the trombone symmetry under which and .
Special solutions
There are a number of special solutions in 11D supergravity, with the most notable ones being the pp-wave, M2-branes, M5-branes, KK-monopoles, and the M9-brane. Brane solutions are solitonic objects within supergravity that are the low-energy limit of the corresponding M-theory branes. The 3-form gauge field couples electrically to M2-branes and magnetically to M5-branes. Explicit supergravity solitonic solutions for the M2-branes and M5-branes are known.
M2-branes and M5-branes have a regular non-degenerate event horizon whose constant time cross-sections are topologically 7-spheres and 4-spheres, respectively. The near-horizon limit of the extreme M2-brane is given by an geometry while for the extreme M5-brane it is given by . These extreme-limit solutions preserve half of the supersymmetry of the vacuum solution, meaning that both the extreme M2-branes and the M5-branes can be seen as solitons interpolating between two maximally supersymmetric Minkowski vacua at infinity, with an or horizon, respectively.
Compactification
The Freund–Rubin compactification of 11D supergravity shows that it preferentially compactifies to seven and four dimensions, which led to it being extensively studied throughout the 1980s. This compactification is most easily achieved by demanding that the compact and noncompact manifolds have a Ricci tensor that is proportional to the metric, meaning that they are Einstein manifolds. One additionally demands that the solution is stable against fluctuations, which in anti-de Sitter spacetimes requires that the Bretenlohner–Freedman bound is satisfied. Stability is guaranteed if there is some unbroken supersymmetry, although there also exist classically stable solutions that fully break supersymmetry.
One of the main compactification manifolds studied was the 7-sphere. The manifold has 8 Killing spinors, meaning that the resulting four dimensional theory has supersymmetry. Additionally, it also results in an gauge group, corresponding to the isometry group of the sphere. A similar widely studied compactification was using a squashed 7-sphere, which can be acquired by embedding the 7-sphere in a quaternionic projective space, with this giving a gauge group of .
A key property of 7-sphere Kaluza-Klein compactifications is that their truncation is consistent, which is not necessarily the case for other Einstein manifolds besides the 7-torus. An inconsistent truncation means that the resulting four dimensional theory is not consistent with the higher dimensional field equations. Physically this needs not be a problem in compactifications to Minkowski spacetimes as the inconsistent truncation merely results in additional irrelevant operators in the action. However, most Einstein manifold compactifications are to anti-de Sitter spacetimes which have a relatively large cosmological constant. In this case irrelevant operators can be converted to relevant ones through the equation of motion.
Related theories
While eleven-dimensional supergravity is the unique supergravity in eleven dimensions at the level of an action, a related theory can be acquired at the level of the equations of motion, known as modified 11D supergravity. This is done by replacing the spin connection by one that is conformally related to the original. Such a theory is inequivalent to standard 11D supergravity only in spaces that are not simply connected. An action for a massive 11D theory can also be acquired by introducing an auxiliary nondynamical Killing vector field, with this theory reducing to massive type IIA supergravity upon dimensional reduction. This is not a proper eleven-dimensional theory since the fields explicitly do not depend on one of the coordinates, but it is nonetheless useful for studying massive branes.
Dimensionally reducing 11D supergravity to ten dimensions gives rise to type IIA supergravity, while dimensionally reducing it to four dimensions can give supergravity, which was one of the original motivations for constructing the theory. While eleven-dimensional supergravity is not UV finite, it is the low energy limit of M-theory. The supergravity also receives corrections at the quantum level, where these corrections sometimes playing an important role in various compactification mechanisms.
Unlike for supergravity in other dimensions, an extension to eleven dimensional anti-de Sitter spacetime does not exist. While the theory is the supersymmetric theory in the highest number of dimensions, the caveat is that this only holds for spacetime signatures with one temporal dimension. If arbitrary spacetime signatures are allowed, then there also exists a supergravity in twelve dimensions with two temporal dimensions.
Notes
References
Supersymmetric quantum field theory
Theories of gravity
String theory | Eleven-dimensional supergravity | [
"Physics",
"Astronomy"
] | 2,488 | [
"Astronomical hypotheses",
"Supersymmetric quantum field theory",
"Theoretical physics",
"Theories of gravity",
"String theory",
"Supersymmetry",
"Symmetry"
] |
77,141,018 | https://en.wikipedia.org/wiki/Lolamicin | Lolamicin is an experimental antibiotic. It targets Gram-negative bacteria without significantly affecting typical gut microbes. Lolamicin was discovered by a team led by Paul Hergenrother at the University of Illinois Urbana-Champaign and was first reported in 2024.
In a mouse model of bacterial infection, lolamicin was found to be especially effective against Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae.
Lolamicin works by interfering with the lipoprotein transport system of Gram-negative bacteria.
References
Antibiotics
Pyrazoles
Pyridines
Benzonitriles
Aromatic ethers | Lolamicin | [
"Biology"
] | 135 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
77,141,187 | https://en.wikipedia.org/wiki/CHZ868 | CHZ868 is a drug which acts as a Janus kinase inhibitor selective for the JAK2 subtype. It was one of the first Janus kinase inhibitors developed, originally for the treatment of leukemia and related blood cancers, and while it did not get approved for clinical use, it is still used for research in the area.
See also
Fedratinib
Pacritinib
References
Non-receptor tyrosine kinase inhibitors
Janus kinase inhibitors
Fluoroarenes
Anilines
Benzimidazoles
Pyridines
Acetamides
Guanidines | CHZ868 | [
"Chemistry"
] | 116 | [
"Pharmacology",
"Guanidines",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs"
] |
77,142,193 | https://en.wikipedia.org/wiki/FERC%20Order%20490 | FERC Order 490 was a final rule by the Federal Energy Regulatory Commission to amend its regulations concerning the abandonment of certain sales and purchases of natural gas under Section 7(b) the Natural Gas Act (NGA) where the underlying contract has expired. It was enacted on April 12, 1988. The following year, an environment of more deregulation took place with the enactment of Natural Gas Wellhead Decontrol Act of 1989.
Rationale for the rule
The goal of the order was to allow more affordable natural gas for the consumer. Gas from a producer going to a national pipeline would have the ability to switch to a regional pipeline. Contracts with high prices could be abandoned, which would lower prices for the consumer as a result.
Prior to the rule, gas that was dedicated to an interstate pipeline or similar customer could not sell the gas to anyone else until FERC found that "abandonment is required by the public convenience and necessity" under Section 7(b) of the NGA. The logic was the right to abandon contracts on interstate pipelines could allow gas to regional pipelines, if needed.
Criticism
In Corinne B. Grace v. El Paso Natural Gas Company, FERC made the following statement:Order No. 490 was never intended to be an unconstrained grant of regulatory authority to interstate pipelines to terminate and abandon small producer contracts, subject only to later judicial review of the contract expiration dispute. At a minimum, the Commission should investigate the types of serious allegations presented here by the complainant and render a decision based on the substantive merits. As a practical matter, in the absence of such investigation, many small producers effectively will have no remedy of any kind in the event of such alleged pipeline conduct, because a contract lawsuit will be financially burdensome, if not impossible. Consequently, I urge the Commission to reconsider this policy.
References
Energy regulatory authorities
Energy law
Energy policy | FERC Order 490 | [
"Environmental_science"
] | 383 | [
"Environmental social science",
"Energy policy"
] |
77,142,648 | https://en.wikipedia.org/wiki/PH-797804 | PH-797804 is a drug which acts as a selective inhibitor of the enzyme p38 mitogen-activated protein kinase (p38 MAPK). It has antiinflammatory effects and has been researched for the treatment of inflammatory lung conditions such as chronic obstructive pulmonary disease and COVID-19. While it has not been adopted for clinical use, it remains widely used in research.
See also
NJK14047
Pamapimod
References
Benzamides
2-Pyridones
Fluoroarenes
Bromoarenes
Aromatic ethers | PH-797804 | [
"Chemistry"
] | 119 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,142,695 | https://en.wikipedia.org/wiki/NJK14047 | NJK14047 is a drug which acts as a selective inhibitor of the enzyme p38 mitogen-activated protein kinase (p38 MAPK). It has antiviral and antiinflammatory effects and was originally developed as a potential treatment for inflammatory lung conditions such as influenza. Subsequent research has also shown promise for various other conditions in which inflammation plays a role, including Alzheimer's disease, asthma, arthritis and psoriasis.
See also
Pamapimod
PH-797804
References
Benzamides
Benzophenones
Glycerols
Cyclopropyl compounds | NJK14047 | [
"Chemistry"
] | 124 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,142,795 | https://en.wikipedia.org/wiki/Pamapimod | Pamapimod is an investigational drug which is being evaluated for the treatment of autoimmune diseases. It is a p38 mitogen-activated protein kinase inhibitor. It has been evaluated in a phase 2 clinical trial for the treatment of rheumatoid arthritis, but was found not to be effective. It has subsequently been investigated as a possible treatment for osteoarthritis.
See also
NJK14047
PH-797804
References
Pyridopyrimidines
Fluoroarenes
Aromatic ethers
Diols
Secondary amines | Pamapimod | [
"Chemistry"
] | 117 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,142,804 | https://en.wikipedia.org/wiki/Metric%20projection | In mathematics, a metric projection is a function that maps each element of a metric space to the set of points nearest to that element in some fixed sub-space.
Formal definition
Formally, let X be a metric space with distance metric d, and let M be a fixed subset of X. Then the metric projection associated with M, denoted pM, is the following set-valued function from X to M:Equivalently:The elements in the set are also called elements of best approximation. This term comes from constrained optimization: we want to find an element nearer to x, under the constraint that the solution must be a subset of M. The function pM is also called an operator of best approximation.
Chebyshev sets
In general, pM is set-valued, as for every x, there may be many elements in M that have the same nearest distance to x. In the special case in which pM is single-valued, the set M is called a Chebyshev set. As an example, if (X,d) is a Euclidean space (Rn with the Euclidean distance), then a set M is a Chebyshev set if and only if it is closed and convex.
Continuity
If M is non-empty compact set, then the metric projection pM is upper semi-continuous, but might not be lower semi-continuous. But if X is a normed space and M is a finite-dimensional Chebyshev set, then pM is continuous.
Moreover, if X is a Hilbert space and M is closed and convex, then pM is Lipschitz continuous with Lipschitz constant 1.
Applications
Metric projections are used both to investigate theoretical questions in functional analysis and for practical approximation methods. They are also used in constrained optimization.
External links
Do projections onto convex sets always decrease distances?
References
Approximation theory
Metric spaces | Metric projection | [
"Mathematics"
] | 371 | [
"Mathematical structures",
"Approximation theory",
"Space (mathematics)",
"Metric spaces",
"Mathematical relations",
"Approximations"
] |
77,143,022 | https://en.wikipedia.org/wiki/Defeng%20Sun | Defeng Sun (Chinese name: 孙德锋) is a Chinese applied mathematician and operations researcher. He holds the position of Chair Professor of Applied Optimization and Operations Research, and has been serving as the Head of Department of Applied Mathematics in The Hong Kong Polytechnic University (PolyU) since 2019. Sun had been the President of The Hong Kong Mathematical Society in 2020-2024.
Education
Sun received his Ph.D. degree in 1995 from Chinese Academy of Sciences in Beijing, after obtaining his bachelor’s and Master’s degree from Nanjing University in 1989 and 1992, respectively.
Research
Sun’s research interests lie in the broad areas of non-convex continuous optimization and machine learning including mathematical theory, algorithmic developments and real-world applications.
In 2006, he solved the long-standing open question of characterizing the strong regularity of nonlinear semidefinite programming (SDP) problems.
Sun was awarded the triennial 2018 Beale-Orchard-Hays Prize for Excellence in Computational Mathematical Programming by Mathematical Optimization Society jointly with his collaborators for the work on software SDPNAL/SDPNAL+ for general purpose large scale semidefinite programming problems
Awards
He was named a SIAM Fellow in 2020 , for "contributions to algorithms and software for conic optimization, particularly matrix optimization", and Fellow of China Society for Industrial and Applied Mathematics in 2020 "for contributions to the field of industrial and applied mathematics"
He received the RGC Senior Research Fellowship for his project "Nonlinear Conic Programming: Theory, Algorithms and Software" by Hong Kong's University Grants Committee in 2022/23.
References
External links
The Hong Kong Mathematical Society
Applied mathematicians
Year of birth missing (living people)
Living people
21st-century Chinese mathematicians
Academic staff of Hong Kong Polytechnic University
Nanjing University alumni
Fellows of the Society for Industrial and Applied Mathematics | Defeng Sun | [
"Mathematics"
] | 365 | [
"Applied mathematics",
"Applied mathematicians"
] |
77,143,999 | https://en.wikipedia.org/wiki/Huijiwiki | Huijiwiki () is a Chinese-language wiki farm based on MediaWiki, launched in February 2015 by MediaWiki user SerGawen and wiki developer Reasno. The creators formerly operated the Chinese language edition of Wikia's A Song of Ice and Fire Wiki. It allows users to apply for and create wikis about a particular topic on its platform. It is currently developed and maintained by Beijing Carmen Jeno Network Technology Co., Ltd. and has more than 100,000 registered users. It is the world's fourth-largest MediaWiki-powered web platform (measured by the number of pages) and the second-largest MediaWiki farm overall.
Currently, Huijiwiki has over 400 hosted sites and close to 10 million edits have been made.
History
One of the founders, Gao Anh, has always been fond of researching all kinds of worldviews and American dramas and games, and is an administrator of the A Song of Ice and Fire Chinese Wiki, which is hosted on the wiki farm Wikia. However, Wikia's outdated style, excessive limitations, poor Chinese language support, and blocking by the People's Republic of China kept him wondering why there wasn't a wiki farm in mainland China. On the other hand, Gao Aung, who was already in his fourth year of work, began to feel bored with his job, which was planning for a handheld game. He told another administrator of the A Song of Ice and Fire Chinese Wiki, Gu Xi, about his idea of "making a wikia by himself". After a conversation, Gu Xi chose to go back to his country and work with Gao Aang to make a "wikia in China".
On January 19, 2022, Huijiwiki was mistakenly thought to be closed because the owner forgot to renew the server.
References
External links
Free-content websites
MediaWiki websites
Wiki farms
Wikis
Chinese websites | Huijiwiki | [
"Technology"
] | 405 | [
"Computing stubs",
"World Wide Web stubs"
] |
77,144,455 | https://en.wikipedia.org/wiki/PKS%201402%2B044 | PKS 1402+044 is a quasar located in the constellation of Virgo. It has a redshift of 3.207, estimating the object to be located 11.3 billion light-years away from Earth.
Characteristics
PKS 1402+044 is classified as a broad absorption-line quasar (BAL QSO) observed by Sloan Digital Sky Survey with a flat-spectrum radio source. It is also classified a blazar, a type of active galaxy and such produces a powerful astrophysical jet that is shot out into the depths of intergalactic space.
The blazar is known to be in its quiescent state, but it shows repeated periods of outbursts that are visible throughout the electromagnetic spectrum. According to observations from Gamma-Ray Blazar Survey and Fermi Gamma-Ray Space Telescope, PKS 1402+044 is found optically variable with >6σ significance, γ-ray detected and more Compton dominated than high synchrotron peaked (HSP) BL Lac objects.
Through radio imaging by researchers, the quasar is core-dominated with fluctuating radio emission and radio morphology found smaller in comparison of steep-spectrum quasars. The quasar is radio-loud with straightened jet magnetic fields along its source axis and a lobe field found to have a misaligned orientation.
References
Quasars
Virgo (constellation)
Blazars
Supermassive black holes
Active galaxies
2827828
SDSS objects
BL Lacertae objects | PKS 1402+044 | [
"Physics",
"Astronomy"
] | 315 | [
"Black holes",
"Unsolved problems in physics",
"Supermassive black holes",
"Virgo (constellation)",
"Constellations"
] |
77,144,783 | https://en.wikipedia.org/wiki/PrivateBin | PrivateBin is a self-hosted and open-source pastebin software. PrivateBin is a text hosting service that deletes pasted text, after a visit. It can be configured to not delete the paste after first view, at which point there is an option of commenting and replying to the paste, like in a forum. All pastes on PrivateBin are encrypted with a password. The encryption is both during transport and at rest.
PrivateBin was forked from ZeroBin.
Features
PrivateBin also supports:
QR code generation from URLs for sharing
Language selection
File upload support
Syntax highlighting with prettify.js
Markdown support
Expiry after first visit or certain time.
References
2016 software
Free software programmed in PHP
Free software programmed in JavaScript
File sharing
File sharing services
Web applications
Web hosting
Text | PrivateBin | [
"Technology"
] | 172 | [
"Computing stubs",
"Software stubs"
] |
77,145,895 | https://en.wikipedia.org/wiki/Armstrong%20process | The Armstrong process is used to refine titanium. Its output is particle-sized dust which can be sprayed into pattern-molds. It was patented in 1999. The output of this process has a "coral-like morphology", which differs from the traditional outputs like "spherical gas-atomized powder, mechanically crushed angular particles, or the titanium sponge morphology created during the Kroll process."
History
The Armstrong process was patented in 1999.
In 2016 a paper by MacDonald et al. told that the Armstrong powder was produced directly from the reduction of Titanium tetrachloride "in a continuous liquid loop", and cost only "11-24 USD/kg", or roughly an order of magnitude higher than the price of steel.
Description
The reducing agent for the Armstrong process is sodium, which is liquefied and introduced in a combined stream with titanium tetrachloride.
{TiCl4} + 4{Na} ->[98~^{\circ}\mathrm{C}]{Ti} + 4{NaCl}
References
Industrial processes
Metallurgical processes
Titanium processes
Materials science
1999 introductions
20th-century inventions
American inventions | Armstrong process | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 238 | [
"Applied and interdisciplinary physics",
"Metallurgical processes",
"Metallurgy",
"Materials science",
"Titanium processes",
"nan"
] |
77,147,021 | https://en.wikipedia.org/wiki/Hyaluromycin | Hyaluromycin is a member of the rubromycin family of antibiotics that inhibits the hydrolysis of hyaluronic acid by hyaluronidase. It has been isolated from cultures of Streptomyces hyaluromycini.
References
Naphthofurans
Pyranochromenes
Cyclopentenes
Carboxamides
Spiro compounds
Polyols
Ketones
Methoxy compounds | Hyaluromycin | [
"Chemistry"
] | 87 | [
"Ketones",
"Organic compounds",
"Functional groups",
"Spiro compounds"
] |
77,147,096 | https://en.wikipedia.org/wiki/List%20of%20inventoried%20hardwoods%20in%20the%20United%20States | Silvics of North America (1991), a forest inventory compiled and published by the United States Forest Service, includes many hardwood trees. It superseded Silvics of Forest Trees of the United States (1965), which was the first extensive American tree inventory. A variety of statistics on all of these trees are maintained by the National Plant Data Team of the US Department of Agriculture.
Hardwood from North American trees has a variety of commercial uses, including in furniture, carpentry, tools and musical instruments. Some timber is milled for plywood, wood veneer and construction framing, including structural support beams and studs. Logs can be fashioned into posts and poles. Less sturdy timber is often ground and processed into pulpwood, principally for papermaking. Resins from sap yield wood tar, turpentine or other terpenes. Some resins and other tree products contain dangerous toxins (not generally listed below). Much of the economic value of trees comes from orchards and ornamental uses.
Key
POWO: Plants of the World Online
States west of the Mississippi River: AK Alaska AR Arkansas AZ Arizona CA California CO Colorado HI Hawaii IA Iowa ID Idaho KS Kansas LA Louisiana MN Minnesota MO Missouri MT Montana ND North Dakota NE Nebraska NM New Mexico NV Nevada OK Oklahoma OR Oregon SD South Dakota TX Texas UT Utah WA Washington WY Wyoming
These are often divided up into:
The Western states: AK AZ CA CO HI ID MT NM NV OR UT WA WY
The South Central states: AR LA OK TX
The Midwestern states west of the Mississippi (including MN, which is mostly west or north of the river), also called the western Midwest: IA KS MN MO ND NE SD
States east of the Mississippi: AL Alabama CT Connecticut DE Delaware FL Florida GA Georgia IL Illinois IN Indiana KY Kentucky MA Massachusetts MD Maryland ME Maine MI Michigan MS Mississippi NC North Carolina NH New Hampshire NJ New Jersey NY New York OH Ohio PA Pennsylvania RI Rhode Island TN Tennessee VA Virginia VT Vermont WI Wisconsin WV West Virginia
These are often divided up into:
New England: CT MA ME NH RI VT
The Mid-Atlantic: DE MD NJ NY PA VA WV
The Southeast: AL FL GA KY MS NC SC TN
The Midwestern states east of the Mississippi, also called the eastern Midwest: IL IN MI OH WI
Hardwoods
See also
List of inventoried conifers in Canada
List of inventoried conifers in the United States
Notes
Citations
References
See their terms-of-use license.
Hardwood forest plants
Forests of the United States
Inventoried hardwoods in the United States
Taxonomic lists (species) | List of inventoried hardwoods in the United States | [
"Biology"
] | 528 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
77,148,171 | https://en.wikipedia.org/wiki/Lactarius%20aurantiacus | Lactarius aurantiacus is a species of mushroom in the family Russulaceae and is commonly referred to as the orange milkcap. The common English name "orange milkcap" can also refer to other similar species of fungi, such as Lactarius subflammeus.
Description
L. aurantiacus is a mycorrhizal mushroom that varies in colour from a vibrant orange to a light orangish brown. Its cap is convex with a slightly depressed centre and ranges from 1 to 5 centimetres in diameter. The texture of it is said to be smooth and glossy. The mushroom grows from 2.5cm to 6.5cm tall.
Additionally, like all other species of milkcaps, L. aurantiacus produces a milky latex when bruised or cut.
The mushroom's gills are spaced apart slightly and are a light pink or orange in colour. Its stem is approximately 5-12mm in diameter and has no ring.
Habitat and distribution
This species of macro fungi is mainly found in Europe but has also been sighted in certain parts of Asia and North America. They grow either alone or in small groups.
L. aurantiacus grows in acidic soils near pine, spruce, and sometimes birch trees in forests. It creates a mycorrhizal relationship with one or more of the trees that are around it.
Similar species
Lactarius fulvissimus
Lactarius subflammeus (also commonly called "orange milkcap")
References
aurantiacus
Fungi of Europe
Fungus species | Lactarius aurantiacus | [
"Biology"
] | 315 | [
"Fungi",
"Fungus species"
] |
71,202,585 | https://en.wikipedia.org/wiki/Micropsalliota%20albofelina | Micropsalliota albofelina is a basidiomycete mushroom native to tropical evergreen forests in Vietnam. It was collected in Bù Gia Mập National Park in 2011 and described in 2021. This mushroom has white, tiny basidiomes, the entire surface of which is covered by thin hairs. This species is the first generic report for Vietnam.
Etymology
The specific epithet albofelina comes from Latin (albus, "white" + felis "cat") referring to the surface of basidiomes that resembles white feline fur.
Description
The whole basidiome of M. albofelina is pure white when fresh, discolouring to brown when dry. The pileus is up to 5 mm in diameter, convex, the surface of it is covered by white hairs. The gills are free, with 1–2 series of lamellulae. The stipe is up to 29 mm tall by 1.5 mm wide, cylindrical, without a ring. The spores are 5.5–7.5 by 3.5–4 μm, ellipsoid in form, with apical thickening. The basidia are 12.5–17.5 by 6.5–8 μm, clavate with 4 sterigmata. The cheilocystidia are 33–34.5 by 10–13 μm, irregularly lecythiform, capitate, with a long, narrow and fragile neck.
References
Agaricaceae
Fungi of Asia
Flora of Vietnam
Fungi described in 2021
Fungus species | Micropsalliota albofelina | [
"Biology"
] | 320 | [
"Fungi",
"Fungus species"
] |
71,202,789 | https://en.wikipedia.org/wiki/HD%20193721 | HD 193721 (HR 7785) is an astrometric binary in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.77, allowing it to be faintly seen with the naked eye. Parallax measurements place the system 760 light years away from the Solar System and it is currently receding with a heliocentric radial velocity .
HD 193721 has a stellar classification of G6/8 II — intermediate between a G6 and 8 bright giant. At present it has 3.49 times the mass of the Sun, but has expanded to 24.4 times its girth. It shines with a luminosity of from its enlarged photosphere at an effective temperature of , giving a yellow hue. HD 193721 is metal deficient with an iron abundance 71% that of the Sun and spins leisurely with a projected rotational velocity of .
The system has an companion designated CPD −81°900. The object has a spectral classification of F8 and is located along a position angle of (as of 1998). CPD −81°900 is a foreground object, having a higher parallax and different proper motion.
References
G-type bright giants
Octans
Astrometric binaries
Double stars
193721
PD-81 00901
101427
7785
Octantis, 47 | HD 193721 | [
"Astronomy"
] | 275 | [
"Octans",
"Constellations"
] |
71,203,723 | https://en.wikipedia.org/wiki/Nissim%20Calderon%20%28scientist%29 | Nissim Calderon (1 April 1933 – 24 February 2020) was a Goodyear executive and scientist, noted for his introduction of olefin metathesis in 1967. His work on olefin metathesis led to the 2005 Nobel Prize in Chemistry.
Education
Calderon earned his MS in Chemistry from Hebrew University in 1958. In 1962, he completed his PhD in Polymer science at the University of Akron.
Personal
Calderon was born in Jerusalem on 1 April 1933, the son of Jacob and Rina (Behar) Calderon. Calderon married Rivka Rapoport on July 26, 1961. They had two children.
Career
Calderon joined Goodyear Tire and Rubber Company in 1962. In 1967, he was promoted to Section Head of Elastomers Research Division. In 1983, he became manager of tire materials research. In 1998, he retired as Vice President. Dr. Calderon held this position as an officer of the company for twelve years until his retirement. Under Calderon's stewardship, Goodyear entered into four major CRADA programs with Sandia National Laboratories, focused on the development of modeling tools for predicting composite performance.
Awards
1994 – Carl-Dietrich Medal by DKG, the German Rubber Society
2020 – Charles Goodyear Medal of the Rubber Division of the American Chemical Society. Because Calderon passed away before the award ceremony, the award was accepted on his behalf by longtime collaborator and friend Adel Halasa. During his remarks, Halasa – an Arab originally from Jordan – said of Calderon: "Jewish and Arab, harmoniously we worked together as friends forever. Only in America. Here's what happened. He said to me, 'I love this country.' I said to him, 'I love this country.' Because both of us can sit down and eat lunch together. Only in America."
References
1933 births
2020 deaths
Polymer scientists and engineers
Jewish scientists
Scientists from Jerusalem
Tire industry people
Goodyear Tire and Rubber Company people | Nissim Calderon (scientist) | [
"Chemistry",
"Materials_science"
] | 389 | [
"Polymer scientists and engineers",
"Physical chemists",
"Polymer chemistry"
] |
71,204,216 | https://en.wikipedia.org/wiki/Upsilon%20Octantis | Upsilon Octantis (Upsilon Oct), Latinized from υ Octantis, is a solitary star in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude of 5.75 and is located 343 light years away from the Solar System. However, it is receding with a heliocentric radial velocity of .
Upsilon Oct has a stellar classification of K0 III, indicating that it is a red giant. At present it has 2.12 times the mass of the Sun but has expanded to 10.3 times its girth. It shines with a luminosity of from its enlarged photosphere at an effective temperature of , giving a yellowish orange hue when viewed at night. Upsilon Oct has a solar metallicity, with an iron abundance equivalent to the Sun's. It spins leisurely with a poorly-constrained projected rotational velocity of .
References
K-type giants
Octans
Octantis, Upsilon
Octantis, 71
PD-86 00406
211539
111196
8505 | Upsilon Octantis | [
"Astronomy"
] | 226 | [
"Octans",
"Constellations"
] |
71,208,584 | https://en.wikipedia.org/wiki/Zinc%20in%20biology | Zinc is an essential trace element for humans and other animals, for plants and for microorganisms. Zinc is required for the function of over 300 enzymes and 1000 transcription factors, and is stored and transferred in metallothioneins. It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all enzyme classes.
In proteins, zinc ions are often coordinated to the amino acid side chains of aspartic acid, glutamic acid, cysteine and histidine. The theoretical and computational description of this zinc binding in proteins (as well as that of other transition metals) is difficult.
Roughly grams of zinc are distributed throughout the human body. Most zinc is in the brain, muscle, bones, kidney, and liver, with the highest concentrations in the prostate and parts of the eye. Semen is particularly rich in zinc, a key factor in prostate gland function and reproductive organ growth.
Zinc homeostasis of the body is mainly controlled by the intestine. Here, ZIP4 and especially TRPM7 were linked to intestinal zinc uptake essential for postnatal survival.
In humans, the biological roles of zinc are ubiquitous. It interacts with "a wide range of organic ligands", and has roles in the metabolism of RNA and DNA, signal transduction, and gene expression. It also regulates apoptosis. A review from 2015 indicated that about 10% of human proteins (~3000) bind zinc, in addition to hundreds more that transport and traffic zinc; a similar in silico study in the plant Arabidopsis thaliana found 2367 zinc-related proteins.
In the brain, zinc is stored in specific synaptic vesicles by glutamatergic neurons and can modulate neuronal excitability. It plays a key role in synaptic plasticity and so in learning. Zinc homeostasis also plays a critical role in the functional regulation of the central nervous system. Dysregulation of zinc homeostasis in the central nervous system that results in excessive synaptic zinc concentrations is believed to induce neurotoxicity through mitochondrial oxidative stress (e.g., by disrupting certain enzymes involved in the electron transport chain, including complex I, complex III, and α-ketoglutarate dehydrogenase), the dysregulation of calcium homeostasis, glutamatergic neuronal excitotoxicity, and interference with intraneuronal signal transduction. L- and D-histidine facilitate brain zinc uptake. SLC30A3 is the primary zinc transporter involved in cerebral zinc homeostasis.
Enzymes
Zinc is an efficient Lewis acid, making it a useful catalytic agent in hydroxylation and other enzymatic reactions. The metal also has a flexible coordination geometry, which allows proteins using it to rapidly shift conformations to perform biological reactions. Two examples of zinc-containing enzymes are carbonic anhydrase and carboxypeptidase, which are vital to the processes of carbon dioxide () regulation and digestion of proteins, respectively.
In vertebrate blood, carbonic anhydrase converts into bicarbonate and the same enzyme transforms the bicarbonate back into for exhalation through the lungs. Without this enzyme, this conversion would occur about one million times slower at the normal blood pH of 7 or would require a pH of 10 or more. The non-related β-carbonic anhydrase is required in plants for leaf formation, the synthesis of indole acetic acid (auxin) and alcoholic fermentation.
Carboxypeptidase cleaves peptide linkages during digestion of proteins. A coordinate covalent bond is formed between the terminal peptide and a C=O group attached to zinc, which gives the carbon a positive charge. This helps to create a hydrophobic pocket on the enzyme near the zinc, which attracts the non-polar part of the protein being digested.
Signalling
Zinc has been recognized as a messenger, able to activate signalling pathways. Many of these pathways provide the driving force in aberrant cancer growth. They can be targeted through ZIP transporters.
Other proteins
Zinc serves a purely structural role in zinc fingers, twists and clusters. Zinc fingers form parts of some transcription factors, which are proteins that recognize DNA base sequences during the replication and transcription of DNA. Each of the nine or ten ions in a zinc finger helps maintain the finger's structure by coordinately binding to four amino acids in the transcription factor.
In blood plasma, zinc is bound to and transported by albumin (60%, low-affinity) and transferrin (10%). Because transferrin also transports iron, excessive iron reduces zinc absorption, and vice versa. A similar antagonism exists with copper. The concentration of zinc in blood plasma stays relatively constant regardless of zinc intake. Cells in the salivary gland, prostate, immune system, and intestine use zinc signaling to communicate with other cells.
Zinc may be held in metallothionein reserves within microorganisms or in the intestines or liver of animals. Metallothionein in intestinal cells is capable of adjusting absorption of zinc by 15–40%. However, inadequate or excessive zinc intake can be harmful; excess zinc particularly impairs copper absorption because metallothionein absorbs both metals.
The human dopamine transporter contains a high affinity extracellular zinc binding site which, upon zinc binding, inhibits dopamine reuptake and amplifies amphetamine-induced dopamine efflux in vitro. The human serotonin transporter and norepinephrine transporter do not contain zinc binding sites. Some EF-hand calcium binding proteins such as S100 or NCS-1 are also able to bind zinc ions.
Nutrition
Dietary recommendations
The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for zinc in 2001. The current EARs for zinc for women and men ages 14 and up is 6.8 and 9.4 mg/day, respectively. The RDAs are 8 and 11 mg/day. RDAs are higher than EARs so as to identify amounts that will cover people with higher-than-average requirements. RDA for pregnancy is 11 mg/day. RDA for lactation is 12 mg/day. For infants up to 12 months, the RDA is 3 mg/day. For children ages 1–13 years, the RDA increases with age from 3 to 8 mg/day. As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of zinc the adult UL is 40 mg/day (lower for children). Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs).
The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For people ages 18 and older, the PRI calculations are complex, as the EFSA has set higher and higher values as the phytate content of the diet increases. For women, PRIs increase from 7.5 to 12.7 mg/day as phytate intake increases from 300 to 1200 mg/day; for men, the range is 9.4 to 16.3 mg/day. These PRIs are higher than the U.S. RDAs. The EFSA reviewed the same safety question and set its UL at 25 mg/day, which is much lower than the U.S. value.
For U.S. food and dietary supplement labeling purposes, the amount in a serving is expressed as a percent of Daily Value (%DV). For zinc labeling purposes, 100% of the Daily Value was 15 mg, but on May 27, 2016, it was revised to 11 mg. A table of the old and new adult daily values is provided at Reference Daily Intake.
Dietary intake
Animal products such as meat, fish, shellfish, fowl, eggs, and dairy contain zinc. The concentration of zinc in plants varies with the level in the soil. With adequate zinc in the soil, the food plants that contain the most zinc are wheat (germ and bran) and various seeds, including sesame, poppy, alfalfa, celery, and mustard. Zinc is also found in beans, nuts, almonds, whole grains, pumpkin seeds, sunflower seeds, and blackcurrant.
Other sources include fortified food and dietary supplements in various forms. A 1998 review concluded that zinc oxide, one of the most common supplements in the United States, and zinc carbonate are nearly insoluble and poorly absorbed in the body. This review cited studies that found lower plasma zinc concentrations in the subjects who consumed zinc oxide and zinc carbonate than in those who took zinc acetate and sulfate salts. For fortification, however, a 2003 review recommended cereals (containing zinc oxide) as a cheap, stable source that is as easily absorbed as the more expensive forms. A 2005 study found that various compounds of zinc, including oxide and sulfate, did not show statistically significant differences in absorption when added as fortificants to maize tortillas.
Deficiency
Nearly two billion people in the developing world are deficient in zinc. Groups at risk include children in developing countries and the elderly with chronic illnesses. In children, it causes an increase in infection and diarrhea and contributes to the death of about 800,000 children worldwide per year. The World Health Organization advocates zinc supplementation for severe malnutrition and diarrhea. Zinc supplements help prevent disease and reduce mortality, especially among children with low birth weight or stunted growth. However, zinc supplements should not be administered alone, because many in the developing world have several deficiencies, and zinc interacts with other micronutrients. While zinc deficiency is usually due to insufficient dietary intake, it can be associated with malabsorption, acrodermatitis enteropathica, chronic liver disease, chronic renal disease, sickle cell disease, diabetes, malignancy, and other chronic illnesses.
In the United States, a federal survey of food consumption determined that for women and men over the age of 19, average consumption was 9.7 and 14.2 mg/day, respectively. For women, 17% consumed less than the EAR, for men 11%. The percentages below EAR increased with age. The most recent published update of the survey (NHANES 2013–2014) reported lower averages – 9.3 and 13.2 mg/day – again with intake decreasing with age.
Symptoms of mild zinc deficiency are diverse. Clinical outcomes include depressed growth, diarrhea, impotence and delayed sexual maturation, alopecia, eye and skin lesions, impaired appetite, altered cognition, impaired immune functions, defects in carbohydrate utilization, and reproductive teratogenesis. Zinc deficiency depresses immunity, but excessive zinc does also.
Despite some concerns, western vegetarians and vegans do not suffer any more from overt zinc deficiency than meat-eaters. Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soy foods, nuts, peas, and seeds. However, phytates in many whole-grains and fibers may interfere with zinc absorption and marginal zinc intake has poorly understood effects. The zinc chelator phytate, found in seeds and cereal bran, can contribute to zinc malabsorption. Some evidence suggests that more than the US RDA (8 mg/day for adult women; 11 mg/day for adult men) may be needed in those whose diet is high in phytates, such as some vegetarians. The European Food Safety Authority (EFSA) guidelines attempt to compensate for this by recommending higher zinc intake when dietary phytate intake is greater. These considerations must be balanced against the paucity of adequate zinc biomarkers, and the most widely used indicator, plasma zinc, has poor sensitivity and specificity.
Soil availability and remediation
Zinc can be present in six different forms in soil namely; water soluble zinc, exchangeable zinc, organically bound zinc, carbonate bound zinc, aluminium and manganese oxide bound zinc and residual fractions of zinc.
In toxic conditions, species of Calluna, Erica and Vaccinium can grow in zinc-metalliferous soils, because translocation of toxic ions is prevented by the action of ericoid mycorrhizal fungi.
Agriculture
Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils. Zinc-deficient soil is cultivated in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas. Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide (zinc phosphide), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.
Biodegradable implants
Zinc (Zn), alongside Magnesium (Mg) and Iron (Fe), constitutes one of the three families of biodegradable metals. Zinc, as an abundant trace element, ranks sixth among all the essential metallic elements crucial for sustaining life within the human body. Zinc exhibits an intermediate biodegradation rate, falling between that of Fe (relatively slow) and Mg (relatively high) which positions it as a promising material for use in biodegradable implants.
References
Bibliography
Biological systems
Biology and pharmacology of chemical elements
Dietary minerals
Nutrition
Physiology
Biology | Zinc in biology | [
"Chemistry",
"Biology"
] | 2,905 | [
"Pharmacology",
"Properties of chemical elements",
"Physiology",
"Biology and pharmacology of chemical elements",
"nan",
"Biochemistry"
] |
71,208,595 | https://en.wikipedia.org/wiki/Molybdenum%20in%20biology | Molybdenum is an essential element in most organisms. It is most notably present in nitrogenase which is an essential part of nitrogen fixation.
Mo-containing enzymes
Molybdenum is an essential element in most organisms; a 2008 research paper speculated that a scarcity of molybdenum in the Earth's early oceans may have strongly influenced the evolution of eukaryotic life (which includes all plants and animals).
At least 50 molybdenum-containing enzymes have been identified, mostly in bacteria. Those enzymes include aldehyde oxidase, sulfite oxidase and xanthine oxidase. With one exception, Mo in proteins is bound by molybdopterin to give the molybdenum cofactor. The only known exception is nitrogenase, which uses the FeMoco cofactor, which has the formula Fe7MoS9C.
In terms of function, molybdoenzymes catalyze the oxidation and sometimes reduction of certain small molecules in the process of regulating nitrogen, sulfur, and carbon. In some animals, and in humans, the oxidation of xanthine to uric acid, a process of purine catabolism, is catalyzed by xanthine oxidase, a molybdenum-containing enzyme. The activity of xanthine oxidase is directly proportional to the amount of molybdenum in the body. An extremely high concentration of molybdenum reverses the trend and can inhibit purine catabolism and other processes. Molybdenum concentration also affects protein synthesis, metabolism, and growth.
Mo is a component in most nitrogenases. Among molybdoenzymes, nitrogenases are unique in lacking the molybdopterin. Nitrogenases catalyze the production of ammonia from atmospheric nitrogen:
The biosynthesis of the FeMoco active site is highly complex.
Molybdate is transported in the body as MoO42−.
Human metabolism and deficiency
Molybdenum is an essential trace dietary element. Four mammalian Mo-dependent enzymes are known, all of them harboring a pterin-based molybdenum cofactor (Moco) in their active site: sulfite oxidase, xanthine oxidoreductase, aldehyde oxidase, and mitochondrial amidoxime reductase. People severely deficient in molybdenum have poorly functioning sulfite oxidase and are prone to toxic reactions to sulfites in foods. The human body contains about 0.07 mg of molybdenum per kilogram of body weight, with higher concentrations in the liver and kidneys and lower in the vertebrae. Molybdenum is also present within human tooth enamel and may help prevent its decay.
Acute toxicity has not been seen in humans, and the toxicity depends strongly on the chemical state. Studies on rats show a median lethal dose (LD50) as low as 180 mg/kg for some Mo compounds. Although human toxicity data is unavailable, animal studies have shown that chronic ingestion of more than 10 mg/day of molybdenum can cause diarrhea, growth retardation, infertility, low birth weight, and gout; it can also affect the lungs, kidneys, and liver. Sodium tungstate is a competitive inhibitor of molybdenum. Dietary tungsten reduces the concentration of molybdenum in tissues.
Low soil concentration of molybdenum in a geographical band from northern China to Iran results in a general dietary molybdenum deficiency, and is associated with increased rates of esophageal cancer. Compared to the United States, which has a greater supply of molybdenum in the soil, people living in those areas have about 16 times greater risk for esophageal squamous cell carcinoma.
Molybdenum deficiency has also been reported as a consequence of non-molybdenum supplemented total parenteral nutrition (complete intravenous feeding) for long periods of time. It results in high blood levels of sulfite and urate, in much the same way as molybdenum cofactor deficiency. Since pure molybdenum deficiency from this cause occurs primarily in adults, the neurological consequences are not as marked as in cases of congenital cofactor deficiency.
A congenital molybdenum cofactor deficiency disease, seen in infants, is an inability to synthesize molybdenum cofactor, the heterocyclic molecule discussed above that binds molybdenum at the active site in all known human enzymes that use molybdenum. The resulting deficiency results in high levels of sulfite and urate, and neurological damage.
Excretion
Most molybdenum is excreted from the human body as molybdate in the urine. Furthermore, urinary excretion of molybdenum increases as dietary molybdenum intake increases. Small amounts of molybdenum are excreted from the body in the feces by way of the bile; small amounts also can be lost in sweat and in hair.
Excess and copper antagonism
High levels of molybdenum can interfere with the body's uptake of copper, producing copper deficiency. Molybdenum prevents plasma proteins from binding to copper, and it also increases the amount of copper that is excreted in urine. Ruminants that consume high levels of molybdenum suffer from diarrhea, stunted growth, anemia, and achromotrichia (loss of fur pigment). These symptoms can be alleviated by copper supplements, either dietary or injection. The effective copper deficiency can be aggravated by excess sulfur.
Copper reduction or deficiency can also be deliberately induced for therapeutic purposes by the compound ammonium tetrathiomolybdate, in which the bright red anion tetrathiomolybdate is the copper-chelating agent. Tetrathiomolybdate was first used therapeutically in the treatment of copper toxicosis in animals. It was then introduced as a treatment in Wilson's disease, a hereditary copper metabolism disorder in humans; it acts both by competing with copper absorption in the bowel and by increasing excretion. It has also been found to have an inhibitory effect on angiogenesis, potentially by inhibiting the membrane translocation process that is dependent on copper ions. This is a promising avenue for investigation of treatments for cancer, age-related macular degeneration, and other diseases that involve a pathologic proliferation of blood vessels.
In some grazing livestock, most strongly in cattle, molybdenum excess in the soil of pasturage can produce scours (diarrhea) if the pH of the soil is neutral to alkaline; see teartness.
References
Biological systems
Biology and pharmacology of chemical elements
Dietary minerals
Biology
Nutrition
Physiology | Molybdenum in biology | [
"Chemistry",
"Biology"
] | 1,468 | [
"Pharmacology",
"Properties of chemical elements",
"Physiology",
"Biology and pharmacology of chemical elements",
"nan",
"Biochemistry"
] |
71,209,614 | https://en.wikipedia.org/wiki/BusKill | BusKill is an open-source hardware and software project that designs computer kill cords to protect the confidentiality of the system's data from physical theft. The hardware designs are licensed CC BY-SA and the software is licensed GPLv3. BusKill cables are available commercially from the official website or through authorized distributors.
The name BusKill is an amalgamation of "Bus" from USB and "Kill" from kill cord.
History
The first computer kill cord was built by Michael Altfield in 2017.
The term "BusKill" was coined by Altfield in January 2020 when publishing the first BusKill build and udev usage instructions (Linux-only), and it was ported by cyberkryption from Linux to Windows a couple weeks later. The project's official website launched the following month.
The first OS X version of the BusKill app was released in May 2020 by Steven Johnson.
A cross-platform rewrite of the software based on Kivy was released in August 2020 with support for Linux, OS X, and Windows.
In December 2021, Alt Shift International OÜ ran a crowdfunding campaign to manufacture BusKill cables on Crowd Supply. The campaign raised $18,507 by January 2022.
Hardware
The BusKill cable is a kill cord that physically tethers a user to their computer with a USB cable.
One end of the cable plugs into a computer. The other end of the cable is a carabiner that attaches to the user.
In the middle of the cable is a magnetic breakaway coupler, to allow the cable to be safely separated at any angle without physically damaging the computer or the user.
A 3D-printable hardware BusKill cable is currently under development.
Software
The BusKill project maintains a cross-platform GUI app that can either lock the screen or shutdown the computer when the cable's connection to the computer is severed and the app is in the "armed" state.
Use
If the computer is separated from the user, then a magnetic breakaway in the cable causes a USB hotplug removal event to execute a trigger in the app.
The trigger executed by the BusKill cable's removal can lock the screen, shutdown, or securely erase the LUKS header and master encryption keys within a few seconds of the cable's separation.
If combined with full disk encryption, then these triggers can be used to ensure the confidentiality of data or be used as a counter-forensics device.
See also
Dead man's switch
USBKill
Tails (operating system)
List of data-erasing software
List of free and open-source software packages
References
External links
Software using the GNU General Public License
Free and open-source software
Free software programmed in Python
Anti-forensic software
Computer security software
Security software
Windows security software
MacOS security software
Linux security software
Cross-platform software
USB | BusKill | [
"Engineering"
] | 573 | [
"Cybersecurity engineering",
"Computer security software"
] |
71,209,771 | https://en.wikipedia.org/wiki/Cobalt%20in%20biology | Cobalt is essential to the metabolism of all animals. It is a key constituent of cobalamin, also known as vitamin B, the primary biological reservoir of cobalt as an ultratrace element. Bacteria in the stomachs of ruminant animals convert cobalt salts into vitamin B, a compound which can only be produced by bacteria or archaea. A minimal presence of cobalt in soils therefore markedly improves the health of grazing animals, and an uptake of 0.20 mg/kg a day is recommended because they have no other source of vitamin B.
Proteins based on cobalamin use corrin to hold the cobalt. Coenzyme B12 features a reactive C-Co bond that participates in the reactions. In humans, B12 has two types of alkyl ligand: methyl and adenosyl. MeB12 promotes methyl (−CH3) group transfers. The adenosyl version of B12 catalyzes rearrangements in which a hydrogen atom is directly transferred between two adjacent atoms with concomitant exchange of the second substituent, X, which may be a carbon atom with substituents, an oxygen atom of an alcohol, or an amine. Methylmalonyl coenzyme A mutase (MUT) converts MMl-CoA to Su-CoA, an important step in the extraction of energy from proteins and fats.
Although far less common than other metalloproteins (e.g. those of zinc and iron), other cobaltoproteins are known besides B12. These proteins include methionine aminopeptidase 2, an enzyme that occurs in humans and other mammals that does not use the corrin ring of B12, but binds cobalt directly. Another non-corrin cobalt enzyme is nitrile hydratase, an enzyme in bacteria that metabolizes nitriles.
Cobalt deficiency
In humans, consumption of cobalt-containing vitamin B12 meets all needs for cobalt. For cattle and sheep, which meet vitamin B12 needs via synthesis by resident bacteria in the rumen, there is a function for inorganic cobalt. In the early 20th century, during the development of farming on the North Island Volcanic Plateau of New Zealand, cattle suffered from what was termed "bush sickness". It was discovered that the volcanic soils lacked the cobalt salts essential for the cattle food chain. The "coast disease" of sheep in the Ninety Mile Desert of the Southeast of South Australia in the 1930s was found to originate in nutritional deficiencies of trace elements cobalt and copper. The cobalt deficiency was overcome by the development of "cobalt bullets", dense pellets of cobalt oxide mixed with clay given orally for lodging in the animal's rumen.
References
Biological systems
Biology and pharmacology of chemical elements
Dietary minerals
Nutrition
Physiology
Biology | Cobalt in biology | [
"Chemistry",
"Biology"
] | 574 | [
"Pharmacology",
"Properties of chemical elements",
"Physiology",
"Biology and pharmacology of chemical elements",
"nan",
"Biochemistry"
] |
71,211,543 | https://en.wikipedia.org/wiki/Yasuyuki%20Tanaka | Prof. Yasuyuki Tanaka (1935 - 1 May 2009) was a Tokyo University of Agriculture and Technology professor noted for elucidating the molecular structure of natural rubber, and for his work in synthetic rubber.
Tanaka received his M.S. (1961) and Ph.D. degrees from Osaka University in the chemistry of structural characterization of elastomers and synthesis of copolymers. After receiving his doctorate, he worked in industry at the Japan Synethic Rubber Company for 12 years. In 1973, he joined the Tokyo University of Agriculture and Technology from which he retired as a professor at the Division of Applied Chemistry in the Faculty of Technology in 2000. He joined the faculty of Chulalongkorn University in 1999 and Mahidol University in 2001.
Tanaka showed that natural rubber is a kind of long-chain telechelic polymer with peptide and phospholipid terminal groups. This was confirmed by the synthesis of model cis- 1,4-polyisoprenes.
Tanaka established a practical method for producing deproteinized natural rubber. Deproteinized natural rubber is free from allergens. His process was applied to the production of allergy-free condoms and gloves.
In 1998 the French Academy of Science awarded Tanaka the "Lavoisier Medal" for his work on the biosynthesis mechanism of natural rubber. In 1999, Tanaka received the Best Research Award from the Society of Rubber Industry, Japan, for his work on the preparation and application of deproteinized natural rubber.
Tanaka was the 2001 recipient of the Charles Goodyear Medal.
The Tanaka Rubber Science and Technology Award was created after his death to support exceptional researchers in rubber science and technology including the disciplines of chemistry, biology, physics, or engineering.
External links
2001 Interview with Yasuyuki Tanaka
References
Polymer scientists and engineers
Japanese chemists | Yasuyuki Tanaka | [
"Chemistry",
"Materials_science"
] | 375 | [
"Polymer scientists and engineers",
"Physical chemists",
"Polymer chemistry"
] |
71,212,159 | https://en.wikipedia.org/wiki/Jean-Marie%20Massoubre | Jean Marie Massoubre (23 November 1921 - 23 August 2020) was a Michelin engineer associated with the early development of the radial tire. He was later in his career on the board of directors of Michelin.
Massoubre received his education in chemistry from ENSIC. During the school year 1943-1944, he received a research allowance to work as a Practical Work Monitor in physical chemistry. The allowance was renewed for the year 1944-1945, but Massoubre resigned as of 1 October 1944.
Massoubre was an R & D coordinator at Michelin. Over his career he received many patents for tire technology. He was elected to the Board of Directors on November 21, 1986. He was re-elected to the Board of Directors on December 15, 1989, and elected Honorary Chairman of the Board of Directors on November 13, 1992.
Massoubre was the 1976 recipient of the Colwyn Medal. He was the 1989 recipient of the Charles Goodyear Medal.
References
Polymer scientists and engineers
1921 births
2020 deaths
Tire industry people
Michelin people | Jean-Marie Massoubre | [
"Chemistry",
"Materials_science"
] | 213 | [
"Polymer scientists and engineers",
"Physical chemists",
"Polymer chemistry"
] |
71,214,116 | https://en.wikipedia.org/wiki/Tramadol/paracetamol | Tramadol/paracetamol, also known as tramadol/acetaminophen and sold under the brand name Ultracet among others, is a fixed-dose combination medication used for the treatment of moderate to severe pain. It contains tramadol, as the hydrochloride, an analgesic; and paracetamol an analgesic. It is taken by mouth.
References
Combination analgesics | Tramadol/paracetamol | [
"Chemistry"
] | 91 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
71,214,358 | https://en.wikipedia.org/wiki/Exportadora%20de%20Sal%20S.A. | Exportadora de Sal S.A. (abbreviated as ESSA) is a company dedicated to salt production through solar evaporation of sea water in the Ojo de Liebre Lagoon, Baja California Sur, Mexico. Founded in 1954 by American shipping businessman Daniel K. Ludwig, it is currently partially owned by the Mexican government and Mitsubishi. It is one of the largest sea-salt extraction and processing operations in the world.
History
Rudimentary extraction of the natural salt deposits formed by the flooding and subsequent evaporation of the low parts of the Ojo de Liebre Lagoon (also known as Scammon's Lagoon) had been ongoing for several decades. American shipping magnate Daniel K. Ludwig obtained a concession from the Mexican government, formally starting the company on April 7, 1954. That date is also the official founding date of the town of Guerrero Negro, which was created to house workers for the new company and grew around it. Ludwig bought the interest of British companies who were the first to exploit the saltworks commercially, and by 1963 he had invested US$63 million, reaching an annual salt production output of in the 1970s. The project became the largest salt works facility in the world and included the construction of a deep-water port to ship the salt in Puerto Morro Redondo, Cedros Island. The company diked the shallow tidal flats around Ojo de Liebre lagoon, creating multiple artificial evaporating ponds, eventually covering an area of about .
In the 1960s Japanese corporation Mitsubishi became the main customer of ESSA and purchased the entire company in 1973 for US$18 million, taking over operations. It is possible that Ludwig's decision to sell was motivated by rumors of a potential expropriation of the company by the centralist government of President Luis Echeverría (1970-1976). In 1976 a new mining law forced Mitsubishi to sell 26% of its stock to the Mexican government, after it had previously sold 25%. Since then ESSA has was jointly owned by the Mexican government (51%) and Mitsubishi (49%), with the company holding exclusive rights to sell the salt. As of 2014 Exportadora de Sal S.A. was referred as the largest salt works, salt producer and exporter in the world, with an yearly output of 8 million tons, constituting around half of Japan's salt imports. Salt exported by ESSA is mainly used in the chemical industry for the production of caustic soda, chlorine and sodium carbonate.
After Gregorio Cavazos Rodríguez quit as ESSA's general director in March 2022, serving in the role for a year, Raúl Franco Morones was named director.
In February 2024 the Mexican government under president López Obrador paid 1,500 million pesos to buy the remaining 49% percent ownership from Mitsubishi. One analysis questioned the economic and commercial benefits to Mexico and characterized the transaction as political and media maneuvering. Even though Mitsubishi initially announced that it would continue to buy salt from ESSA, local media reported later on July that the Japanese corporation was not satisfied with the negotiation and stopped the salt purchases. Due to a reduction in sales more than 5 million tons of salt accumulated in the ports of Chaparrito and Morro Redondo by November 2024, a situation which caused uncertainty, economic hardship and tensions with the salt workers union due to the possibility of layoffs. Further difficulties were caused by machinery malfunction due to obsolescence and lack of maintenance.
Operations
Sea water is pumped into the collection ponds for initial evaporation, with the brine solution moved afterwards to crystallization ponds to finish drying up. The resulting mineral salt is transported in large dumping trucks to Chaparrito Port near Guerrero Negro to be cleaned and loaded into barges. These barges can carry up to of salt to Morro Redondo, where it is inspected, stored and finally exported in ocean-going vessels.
Corruption controversies
Jorge Humberto López Portillo, general director of ESSA from July 2013 to December 2014, was prosecuted for irregularities such as purchasing a new barge for US$27.2 million and signing 30-year contracts with Packsys for residual brine treatment, both actions taken without administrative committee authorization. Packsys sued for breach of contract, but ESSA, represented by law firm O'Melveny, got the case dismissed. López Portillo was banned from civil service for ten years although he contested this and claimed innocence and political persecution. Fellow Institutional Revolutionary Party member Abel Salgado Peña formally requested that López Portillo be expelled from the party due to the accusations of corruption.
In January 2019 Nonato Antonio Avilés Rocha was named by President Andres Manuel López Obrador as ESSA's general director. Avilés Rocha quit in January 2021, after it was found that he gave contracts to companies owned by his cousins and nephews, increased executive salaries above approved limits, signed off unjustified expenses and paid for services that were not provided. Irregular salt sales were also detected.
Environmental impact
In 1994, seeking to increase its production output, ESSA proposed an expansion of its facilities into the nearby San Ignacio Lagoon which is part of El Vizcaíno Biosphere Reserve, a whale and migratory bird sanctuary. After Serge Dedina, founder of Wildcoast, exposed these plans, a opposition campaign was carried out by prominent intellectuals, artists, and several NGOs such as the Natural Resources Defense Council in the United States and the Group of 100 in Mexico. Poet and activist Homero Aridjis, leader of the Group of 100, denounced the potential impact of the project, such as salinity reduction due to the extraction of 462 million metric tons of water from the lagoon, affecting plant and animal life. The opposition effort was successful, culminating with Mexican President Ernesto Zedillo announcing in March 2000 the abandonment of the project.
In 1998 CorpWatch accused Mitsubishi of greenwashing due to "their ongoing public relations initiative to convince the world that it is environmentally benign, as well as socially and economically desirable to establish the largest industrial salt evaporation facility in the world in a lagoon that is the last pristine calving ground of the California gray whale". In 1999 conservation groups including Greenpeace Mexico submitted a formal accusation to the Mexican government against ESSA for environmental law violations. The increased death of green sea turtles (Chelonia mydas) at Ojo de Liebre lagoon has been potentially linked to the dumping of bitterns by ESSA.
A dispute concerning the disposal of the residual brine solution arose between ESSA, local people and environmental activists. Following exhortations from the Mexican Congress, in 2019 the company invested 200 million pesos in a new pumping system to dispose of the residual brine.
References
External links
Mitsubishi's corporate video about ESSA
Mexican companies established in 1954
Mitsubishi companies
Salt production
Companies based in Baja California Sur | Exportadora de Sal S.A. | [
"Chemistry"
] | 1,398 | [
"Salt production",
"Salts"
] |
71,215,326 | https://en.wikipedia.org/wiki/Thom%27s%20first%20isotopy%20lemma | In mathematics, especially in differential topology, Thom's first isotopy lemma states: given a smooth map between smooth manifolds and a closed Whitney stratified subset, if is proper and is a submersion for each stratum of , then is a locally trivial fibration. The lemma was originally introduced by René Thom who considered the case when . In that case, the lemma constructs an isotopy from the fiber to ; whence the name "isotopy lemma".
The local trivializations that the lemma provide preserve the strata. However, they are generally not smooth (not even ). On the other hand, it is possible that local trivializations are semialgebraic if the input data is semialgebraic.
The lemma is also valid for a more general stratified space such as a stratified space in the sense of Mather but still with the Whitney conditions (or some other conditions). The lemma is also valid for the stratification that satisfies Bekka's condition (C), which is weaker than Whitney's condition (B). (The significance of this is that the consequences of the first isotopy lemma cannot imply Whitney’s condition (B).)
Thom's second isotopy lemma is a family version of the first isotopy lemma.
Proof
The proof is based on the notion of a controlled vector field. Let be a system of tubular neighborhoods in of strata in where is the associated projection and given by the square norm on each fiber of . (The construction of such a system relies on the Whitney conditions or something weaker.) By definition, a controlled vector field is a family of vector fields (smooth of some class) on the strata such that: for each stratum A, there exists a neighborhood of in such that for any ,
on .
Assume the system is compatible with the map (such a system exists). Then there are two key results due to Thom:
Given a vector field on N, there exists a controlled vector field on S that is a lift of it: .
A controlled vector field has a continuous flow (despite the fact that a controlled vector field is discontinuous).
The lemma now follows in a straightforward fashion. Since the statement is local, assume and the coordinate vector fields on . Then, by the lifting result, we find controlled vector fields on such that . Let be the flows associated to them. Then define
by
It is a map over and is a homeomorphism since is the inverse. Since the flows preserve the strata, also preserves the strata.
See also
Ehresmann's fibration theorem
Thom–Mather stratified space
Tame topology
Note
References
External links
https://mathoverflow.net/questions/23259/thom-first-isotopy-lemma-in-o-minimal-structures
Differential topology
Lemmas
Stratifications | Thom's first isotopy lemma | [
"Mathematics"
] | 610 | [
"Mathematical theorems",
"Stratifications",
"Topology stubs",
"Topology",
"Differential topology",
"Mathematical problems",
"Lemmas"
] |
71,216,482 | https://en.wikipedia.org/wiki/Triacetylmethane | Triacetylmethane is the organic compound with the formula . It is a colorless liquid that is soluble in organic solvents and in alkaline water. It readily forms an enolate. The enolate forms a variety of metal complexes related to the metal acetylacetonates.
References
Triketones
Chelating agents
Tridentate ligands
3-Hydroxypropenals
Enols | Triacetylmethane | [
"Chemistry"
] | 82 | [
"Enols",
"Chelating agents",
"Functional groups",
"Process chemicals"
] |
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