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70,463,339 | https://en.wikipedia.org/wiki/Genome%20India%20Project | Genome India Project (GIP) is a research initiative led by the Bangalore-based Indian Institute of Science's Centre for Brain Research and involves over 20 universities across the country in an effort to gather samples, compile data, conduct research, and create an ‘Indian reference genome' grid.
Background
The initiative is funded by Department of Biotechnology (DBT) to sequence at least 10,000 Indian genomes in phase 1. The goal of the research is to develop predictive diagnostic indicators for several high-priority diseases and other uncommon and genetic disorders. In phase 2, the project would collect genetic samples from patients with three broad categories - cardiovascular diseases, mental illness, and cancer.
Participating institutions
The list includes:
All India Institute of Medical Sciences, Jodhpur
Centre for Cellular and Molecular Biology
Centre for DNA Fingerprinting and Diagnostics
Institute of Genomics and Integrative Biology
Gujarat Biotechnology Research Centre, Gandhinagar
Indian Institute of Information Technology, Allahabad
Indian Institute of Science Education and Research, Pune
Indian Institute of Technology, Madras
Indian Institute of Technology, Delhi
Indian Institute of Technology Jodhpur
Institute of Bioresources And Sustainable Development, Imphal
Institute of Life Sciences, Bhubhaneswar
Mizoram University
National Centre for Biological Sciences
National Institute of Biomedical Genomics
National Institute of Mental Health and Neurosciences
Rajiv Gandhi Centre for Biotechnology
Sher-i-Kashmir Institute of Medical Sciences
References
Human genome projects
Genetics organizations | Genome India Project | [
"Biology"
] | 289 | [
"Human genome projects",
"Genome projects"
] |
70,463,551 | https://en.wikipedia.org/wiki/Subpsoromic%20acid | Subpsoromic acid is a depsidone with the molecular formula C17H12O8 which has been isolated from the lichen Ocellularia praestans.
References
Lichen products
Oxygen heterocycles
Carboxylic acids
Dioxepines
Heterocyclic compounds with 3 rings
Methoxy compounds
Lactones | Subpsoromic acid | [
"Chemistry"
] | 72 | [
"Carboxylic acids",
"Natural products",
"Functional groups",
"Lichen products"
] |
70,463,845 | https://en.wikipedia.org/wiki/Huawei%20Nova%208 | Huawei Nova 8 is a smartphone manufactured by Huawei. It is a part of Huawei Nova series. It was announced on August 5, 2021.
References
Nova 8
Mobile phones introduced in 2021
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording | Huawei Nova 8 | [
"Technology"
] | 54 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
74,702,517 | https://en.wikipedia.org/wiki/Dark%20taxon | In mycology, a dark taxon (: dark taxa; or dark fungus) is a taxon that does not appear to produce any observable morphological structure and that appears impossible to cultivate in laboratory conditions. Dark taxa are chiefly detected by DNA sequencing, and in particular environmental metabarcoding.
Dark taxa make up a paraphyletic group, with dark taxa appearing in every major fungal lineage. Dark taxa appear to make up a significant portion of extant fungal taxa. According to "the majority of the extant fungal diversity produces no distinguishing morphological structures that are visible or describable", and according to Martin Ryberg dark fungi "could well prove to be the dominant life style in the fungal kingdom".
The naming of dark taxa is not supported by the ICN as a type specimen requires direct observation.
References
Bibliography
Fungus taxa | Dark taxon | [
"Biology"
] | 170 | [
"Fungus stubs",
"Fungi",
"Fungus taxa"
] |
74,706,370 | https://en.wikipedia.org/wiki/Substance-based%20medical%20device | A substance based medical device is a medical device composed of substances or combinations of substances. They are typically differentiated from medication (drugs) in that they do not have pharmacological, immunological or metabolic mode of action but achieve their therapeutic effect through primarily physical means.
Examples
Examples of substance based medical devices include products for gastrointestinal relief like medicinal clay or simeticone-based products, as well as unmedicated nasal sprays, certain eye drops, dermal formulations, oral cough treatments, and other products for self-medication that often are available without a prescription.
Regulation
Substance-based medical devices encompass a varied array of products that fall under the purview of Regulation (EU) 2017/745 (MDR). Based on their intended purpose, they are classified according to rule 21 ("Devices composed of substances that are introduced via a body orifice or applied to the skin") of Annex VIII of the MDR .
References
Regulation of medical devices
Medical devices
Health care | Substance-based medical device | [
"Biology"
] | 205 | [
"Medical devices",
"Medical technology"
] |
74,707,919 | https://en.wikipedia.org/wiki/Raspberry%20Shake | Raspberry Shake is a Panama-based company that designs and manufactures personal seismic and infrasonic sensors, utilizing Raspberry Pi hardware.
History
Raspberry Shake was developed in the Chiriquí province under the Western Seismic Observatory of Panama which creates hardware and software for tectonic phenomena measurement.
While the origins of Raspberry Shake can be traced back to Western Seismic Observatory of Panama, it evolved into an independent company in 2020 when the trademark was registered.
In the years 2015 and 2016, Raspberry Shake began its initial forays into the development of seismic detection software and hardware with the creation of Raspberry Shake 1D. By the end of 2017, hardware and software improvements were added, resulting in the Raspberry Shake 3D Sensor, which brought the capability to capture waves vertically and horizontally. Through continuous development, the Raspberry Shake 4D sensor was launched in July 2017, featuring integrated accelerometers directly on the board.
In early 2018, the Raspberry Boom sensor focused on infrasonic detection was developed; that same year, technologies were combined with those of the Raspberry Shake 1D sensor to launch the Raspberry Shake & Boom, opening up possibilities for seismic and infrasonic detection in a single device.
Technology
The Raspberry Shake is a device that pairs with the Raspberry Pi to function as a personal seismograph. It incorporates a geophone which converts ground movements into electrical signals. An additional board amplifies and digitizes this signal, which is then processed by the Raspberry Pi.
The Raspberry Shake utilizes software similar to that used by the United States Geological Survey (USGS). As technology, particularly mini-computers like the Raspberry Pi, has evolved, the company introduced additional devices, including the sensor "Raspberry Shake 1D" with different detection capabilities.
References
Technology companies
Seismic magnitude scales
Seismology measurement
Earthquake engineering | Raspberry Shake | [
"Engineering"
] | 394 | [
"Earthquake engineering",
"Civil engineering",
"Structural engineering"
] |
74,709,289 | https://en.wikipedia.org/wiki/Oudemansiella%20furfuracea | Oudemansiella furfuracea is a species of mushroom.
Description
Found alone or gregariously from the buried deadwood of hardwoods
Range
Found in eastern North America, widely distributed east of the Rocky Mountains
Ecology
Found growing from the deadwood of hardwoods and occasionally directly from very well decayed logs and stumps.
Taxonomy
Oudemansiella furfuracea contains the following varieties:
Oudemansiella furfuracea var. bispora
Oudemansiella furfuracea var. furfuracea
References
Physalacriaceae
Fungus species | Oudemansiella furfuracea | [
"Biology"
] | 121 | [
"Fungi",
"Fungus species"
] |
74,710,562 | https://en.wikipedia.org/wiki/Ethics%20of%20Political%20Commemoration | The Ethics of Political Commemoration is a framework that seeks to improve remembrance of the past, so that it contributes to a better future. As a moral framework, it is adapted from the Just War tradition, reflecting that remembrance is often conducted with political – and sometimes coercive – intent. Examples of such remembrance includes public events, monuments, museums, street names, among many others.
The framework consists of eight criteria, organized under two subheadings, similar to the Just War theory. These criteria examine questions of merit and restraint when remembrance is mobilized for political purposes. The key idea of the framework is that ethical consideration of the Politics of memory needs to take multiple criteria into account.
Ius ad Memoriam
The Ius ad Memoriam considerations consist of four criteria, that closely mirror the Jus ad bellum criteria of the just war tradition.
Just Cause. Commemoration should look to memorialize that which is significant and most in need of redress. It does not need to establish a grievance in absolute terms.
Right Intention. Commemoration is an ethical undertaking if it contributes to a better future -- and much less so if it seeks to gain advantage over others.
Reasonable Chance of Success. Commemoration becomes unethical if it creates cycles of violence. This gives a special role to empirical social research, to understand the impact of planned commemoration on conflict and its transformation.
Legitimate Authority. Commemoration should speak for the experience of wider society in a compassionate way, rather than being used by elite groups to strengthen their authority over society.
Ius in Memoria
The Ius in Memoria are akin to Ius in Bello, in focusing more on the "how" of commemoration. It has four criteria:
Transcend the Collectives. Commemoration is seen as ethical if it encourages people to treat each other as individuals rather than group representatives.
Exit Circular Narratives. Commemoration should help people exit narratives that trap them in debilitating interpretative loops.
Assert Moral Autonomy. Groups should justify their actions in universal terms, rather than excusing transgressions with reference to what others have done.
Contained Unfathomability. Good commemoration should be precise with dates, locations and names to tether past trauma. Numerical aspects of trauma should typically be communicated in broad categories.
Proponents of the approach argue that taken together, the framework can constitute a comprehensive ethical approach or paradigm for commemoration. They concede that critiques of the just war tradition also apply to this moral framework, in that both pacifist and realist/revolutionary alternatives retain their validity.
Applications
The framework has been applied to a number of cases in various publications, including the Brijuni Museum to Tito; the Stalin Museum in Gori, Georgia; the Bolnisi Museum; the Cascade Memorial in Yerevan; the W. G. Sebald path in Wertach; and the argument has been put forward that the framework can be used also for healthcare institutions that have to deal with legacies of trauma.
In 2023, Mehdi Bchir and David Wood argued that the framework could help "foster a vision for the future" for Libya.
Origin
The framework was first presented at a seminar at Seton Hall University on April 15, 2021. The Ethics of Political Commemoration was also presented at Chatham House in October 2021. Subsequent publications set out the approach in more detail. The core of the framework was developed by Hans Gutbrod, a researcher based at Ilia State University. David Wood, who teaches at Seton Hall University, developed the application of the framework to conflict transformation.
References
Philosophy of law
Reconciliation
Peace mechanisms
Catholic social teaching
Thomas Aquinas
Memory | Ethics of Political Commemoration | [
"Biology"
] | 726 | [
"Just war theory",
"Behavior",
"Aggression"
] |
74,710,664 | https://en.wikipedia.org/wiki/Duan%20Huiling | Duan Huiling () is a Chinese mechanical engineer, specializing in interface mechanics, the interactions between fluids and solids, and the surface properties and elasticity of nanoscale structures. She is dean of engineering at Peking University.
Education and career
Duan studied mechanical engineering at Northeast Petroleum University, graduating with a bachelor's degree in 1995 and earning a master's degree in 1998. From 1998 to 2001 was a lecturer at the university. After returning to graduate study at Peking University, she completed a Ph.D. in solid mechanics in 2005.
She was a postdoctoral researcher at Cardiff University in the United Kingdom, supported by a Royal Society Postdoctoral Fellowship, and at the Institute of Nanotechnology of the Karlsruhe Research Center (FZK-INT, now part of the Karlsruhe Institute of Technology) in Germany, supported by an Alexander von Humboldt Fellowship. In 2007 she returned to China as an associate professor at Peking University, subsequently becoming full professor and, in 2014, Chang Jiang Chair Professor.
At Peking University, she chaired the Department of Mechanics and Engineering Science from 2013 to 2018, and was named dean of the College of Engineering in 2020.
Recognition
Duan was the 2009 recipient of the Sia Nemat-Nasser Early Career Award of the American Society of Mechanical Engineers, which elected her as a Fellow in 2020.
She is also a recipient of the Distinguished Young Scholars Award of the National Natural Science Foundation of China (2012), and was named a National Outstanding Young Female Scientist of China (2014) and National Outstanding Young Scholar of China (2015).
References
External links
Home page
Year of birth missing (living people)
Living people
Chinese mechanical engineers
Chinese women engineers
Nanotechnologists
Northeast Petroleum University alumni
Peking University alumni
Academic staff of Peking University
Fellows of the American Society of Mechanical Engineers | Duan Huiling | [
"Materials_science"
] | 360 | [
"Nanotechnology",
"Nanotechnologists"
] |
74,710,904 | https://en.wikipedia.org/wiki/Carcinomyces | Carcinomyces is a genus of fungi in the order Tremellales. Species are parasites of other fungi and produce anamorphic yeast states. Four species of Carcinomyces are recognized worldwide. The generic placement of a fifth species, Carcinomyces mycetophilus, is currently uncertain.
Taxonomy
History
Carcinomyces was introduced in 1982 by Franz Oberwinkler and Robert Bandoni for two species forming conspicuous, gelatinous galls on fruit bodies of the agaric, Gymnopus dryophilus. The genus was differentiated from Syzygospora and Christiansenia by its agaric hosts and, microscopically, by its lack of zygoconidia (twinned conidia). In 1986, James Ginns placed the genus in synonymy with Syzygospora. Molecular research, based on cladistic analysis of DNA sequences, has, however, shown that Syzygospora is polyphyletic (and hence artificial) and has accepted Carcinomyces as a separate, monophyletic (natural) genus, though no longer restricted to agaric hosts. Two recently described species are known only from their yeast states.
References
Tremellomycetes
Basidiomycota genera
Taxa named by Franz Oberwinkler
Taxa described in 1982
Yeasts | Carcinomyces | [
"Biology"
] | 272 | [
"Yeasts",
"Fungi"
] |
74,711,180 | https://en.wikipedia.org/wiki/Carcinomyces%20mycetophilus | Carcinomyces mycetophilus is a species of fungus in the class Tremellomycetes. It is a parasite, producing extensive, gelatinous galls on basidiocarps (fruit bodies) of its host, the agaric Gymnopus dryophilus. Its generic placement is currently uncertain, but morphologically it is close to the type species of Carcinomyces. It was first described by Charles Horton Peck from North America, where it is widespread and called Collybia jelly. It has also been recorded in continental Europe.
References
Tremellomycetes
Taxa named by Charles Horton Peck
Fungi described in 1875
Fungus species | Carcinomyces mycetophilus | [
"Biology"
] | 137 | [
"Fungi",
"Fungus species"
] |
74,711,248 | https://en.wikipedia.org/wiki/Lithium%20holmium%20fluoride | Lithium holmium fluoride is a ternary salt with chemical formula . At temperatures below 1.53 K, it is ferromagnetic described by the Ising model, but the interaction coefficients arise through superexchange. Above that temperature, it paramagnetizes. Even at 0 K, exhibits a quantum phase transition, aligning with an external magnetic field.
References
Further reading
Types of magnets
Fluorides | Lithium holmium fluoride | [
"Chemistry"
] | 90 | [
"Salts",
"Fluorides",
"Inorganic compounds",
"Inorganic compound stubs"
] |
74,712,348 | https://en.wikipedia.org/wiki/C23H28N4O3 | {{DISPLAYTITLE:C23H28N4O3}}
The molecular formula C23H28N4O3 (molar mass: 408.50 g/mol) may refer to:
Etonitazepipne (N-piperidino etonitazene)
Isotonitazepyne
Protonitazepyne | C23H28N4O3 | [
"Chemistry"
] | 75 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
74,712,392 | https://en.wikipedia.org/wiki/C18H25NO3 | {{DISPLAYTITLE:C18H25NO3}}
The molecular formula C18H25NO3 (molar mass: 303.40 g/mol) may refer to:
EA-3580
CAR-302,668
MDPEP | C18H25NO3 | [
"Chemistry"
] | 55 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
74,712,827 | https://en.wikipedia.org/wiki/Post-acute%20infection%20syndrome | Post-acute infection syndromes (PAISs) or post-infectious syndromes are medical conditions characterized by symptoms attributed to a prior infection. While it is commonly assumed that people either recover or die from infections, long-term symptoms—or sequelae—are a possible outcome as well. Examples include long COVID (post-acute sequelae of SARS-CoV-2 infection, PASC), Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and post-Ebola virus syndrome. Common symptoms include post-exertional malaise (PEM), severe fatigue, neurocognitive symptoms, flu-like symptoms, and pain. The pathology of most of these conditions is not understood and management is generally symptomatic.
Symptoms and signs
PAIS symptoms are often non-specific and similar despite diverse prior infections. Symptoms commonly included in definitions of PAIS include post-exertional malaise, severe fatigue, neurocognitive and sensory symptoms, flu-like symptoms, unrefreshing sleep, muscle pain, and joint pain. Symptoms can vary among affected people. Some PAIS symptoms are more specific. For example, eye problems are common in post-Ebola virus syndrome, and profound weakness is seen in post-polio syndrome and post-West Nile fevers.
Symptoms can be severe and debilitating, resulting in lowered quality of life or inability to work. The onset of symptoms may be delayed, often by decades in the case of post-polio syndrome, and their severity may fluctuate over time.
Causes
Pathogens associated with PAISs include SARS-CoV-2 (causing COVID-19), Ebolavirus, Dengue virus, poliovirus, SARS-CoV-1 (causing SARS), Chikungunya virus, Epstein–Barr virus (EBV), West Nile virus (WNV), Ross River virus (RRV), Coxsackie B, influenza A virus subtype H1N1, varicella zoster virus (VZV), Coxiella burnetii, Borrelia, and Giardia. However, the strength of evidence associating these pathogens with chronic illness varies.
The pathophysiology of most PAISs is poorly understood, but the overlap in symptoms despite disparate infectious triggers implies a possible shared pathology. For most conditions, no chronic infection has been detected.
Mechanism
The pathology of post-acute infections syndromes is not understood. The commonality in symptoms between illnesses may point to a common pathology. Major hypotheses include persistence of the original pathogen or its remnants, autoimmunity, chronic inflammation, reactivation of other latent infections, microbiome dysbiosis, or damage to organs, which may include the lungs, brain, kidneys, heart, or blood vessels.
Diagnosis
In the absence of tests for most PAISes, diagnosis is usually based on the patient's history, symptoms, and eliminating other potential causes. Available tests often fail to explain patients' symptoms, but this does not suggest they are not real. The complexity of diagnosing PAISes may lead to long delays in diagnosis.
Diagnostic criteria vary among illnesses, and have at times been the subject of intense debate. For example, several definitions of ME/CFS have been in use.
Classification
PAIS is a broad term describing conditions attributed to various infections, including long COVID, ME/CFS, post-Ebola virus syndrome, post-dengue fatigue syndrome, post-polio syndrome, post-SARS syndrome, post-chikungunya disease, Q fever fatigue syndrome, post-treatment Lyme disease syndrome (PTLDS), and symptoms observed after other infections lacking a specific name. Other known sequelae of infections include multisystem inflammatory syndrome in children (MIS-C), and subacute sclerosing panencephalitis (a deadly consequence of measles that can be delayed by years).
Management
Treatment options for most PAISes are limited. In general, the focus is on managing symptoms, and management strategies for ME/CFS may benefit patients with similar symptoms.
Prognosis
Some people with PAISs recover over a period ranging from weeks to years while others remain ill. Many studies have shown that symptoms can continue for at least several years until the studies' conclusion. Studies of PTLDS ran longer and found increased rates of symptoms for up to 27 years. In the case of ME/CFS prognosis is poor and the illness is lifelong for most.
Epidemiology
Data on epidemiology is limited by the lack of large, rigorous studies; and rates vary by infection. Mononucleosis is among the best studied, and available studies found that 7-9% had persistent symptoms 12 months after infection, and 4% had serious symptoms after 2 years. The British Office of National Statistics data on long COVID say that about 10% of people who had COVID-19 self-reported long COVID 6 months after infection, and about 7% reported long COVID with activity limitations. An Australian study of EBV, C. burnetii, and Ross River Virus found that 11% of participants met the criteria for ME/CFS at 6 months. Around 10-20% of people with SARS also experienced long-term effects.
History
While PAISs were described prior to the COVID-19 pandemic, the emergence of long COVID brought them increased attention.
Society and culture
PAISs cause a significant disease burden, but have received relatively little attention from scientists, potentially delaying the discovery of causes, diagnostic tests, and treatments. Infectious disease surveillance programs track acute illness but rarely track the health effects of PAISes. Many doctors are also unfamiliar with them, and may fail to take symptoms seriously.
Research
PAISs may have a common cause, and different hypotheses are being studied. Long COVID has increased the overall pace of research. Yale School of Medicine operates a research center, founded in 2023, that focuses on PAISs called the Center for Infection & Immunity.
See also
Postural orthostatic tachycardia syndrome, sometimes attributed to an infection
References
Infectious diseases
Diseases and disorders
Immunology
Neurology | Post-acute infection syndrome | [
"Biology"
] | 1,303 | [
"Immunology"
] |
74,714,115 | https://en.wikipedia.org/wiki/Rien%20Schuurhuis | Rien John Schuurhuis (born 12 August 1982) is a Dutch-born Vatican road cyclist and industrial design engineer who competed for the Vatican City in the 2022, 2023 and 2024 UCI Road World Championships. He was the first cyclist and athlete who represented the Vatican City as a regular scoring competitor.
Career
Schuurhuis started competing internationally for teams such as Oliver's Real Food Racing and Blank Inc Cycling Team under a Dutch sporting nationality.
In 2020 when he moved to Rome, he was "immediately drawn to the values and community spirit of Athletica Vaticana", and in 2021 he started competing for the Vatican City.
Major results
2015
N/A Tour de Perth
18th Melbourne-Warrnambool
33th Tour of Southland
2016
45th New Zealand Cycle Classic
65th Tour de Ijen
75th Tour de Flores
DNF Road race, Dutch National Road Race Championships
N/A Tour of the Great South Coast
N/A Tour of Gippsland
46th Jelajah Malaysia
2017
5th Tour of the Great South Coast
N/A Tour of the King Valley
2018
DNF Herald Sun Tour
DNF Road race, Dutch National Road Race Championships
N/A Tour Tahiti Nui
2nd Stage 1
N/A Tour of New Caledonia
2019
N/A Tour Tahiti Nui
1st Stage 2 and Stage 4
22nd Tour of New Caledonia
3rd Stage 6
2021
40th Time trial, Dutch National Road Race Championships
2022
11th Limburg Cycling Time Trial
DNF Road race, World Championships
2023
DNF Road race, World Championships
2024
DNF Road race, World Championships
Personal life
Schuurhuis was introduced to cycling at a young age saying he "could ride a bike before I could walk," due to the Cycling culture of the Netherlands.
Schuurhuis holds Dutch citizenship due to his birth, Australian citizenship as his wife Chiara Porro is Australian, and Vatican citizenship since he resides there and as his wife is the Australian Ambassador to the Holy See. He moved to Rome in 2020. He has two children, Thomas and George.
References
External links
Rien Schuurhuis at Eurosport
Rien Schuurhuis at World Cycling Stats
Rien Schuurhuis at Pro Cycling Stats
Rien Schuurhuis at First Cycling
Rien Schuurhuis at Sito del Ciclismo
1982 births
Living people
Vatican City cyclists
Dutch cyclists
People from Groningen (city)
21st-century Dutch people
Design engineering | Rien Schuurhuis | [
"Engineering"
] | 506 | [
"Design engineering",
"Design"
] |
74,714,147 | https://en.wikipedia.org/wiki/Carex%20secalina | Carex secalina, the rye sedge, is a species of flowering plant in the family Cyperaceae. It is native to central and eastern Europe, the Caucasus, Iran, Kazakhstan, and on to Siberia, and it has been introduced to the Russian Far East, Belgium, and New York State. It is usually found growing in saline, wet meadows, and so is pre-adapted to grow in ditches next to roads that are heavily salted in winter.
Subtaxa
The following varieties are accepted:
Carex secalina var. alpina – Iran
Carex secalina var. secalina – entire range
References
secalina
Halophytes
Flora of Middle Europe
Flora of Yugoslavia
Flora of Romania
Flora of Eastern Europe
Flora of the Caucasus
Flora of Iran
Flora of Afghanistan
Flora of Kazakhstan
Flora of West Siberia
Flora of Altai (region)
Flora of Tuva
Plants described in 1803 | Carex secalina | [
"Chemistry"
] | 184 | [
"Halophytes",
"Salts"
] |
74,714,157 | https://en.wikipedia.org/wiki/David%20Limebeer | David John Noel Limebeer (born 31 July 1952) is an electrical engineer and academic. He is an Emeritus Professor of Control Engineering at the University of Oxford and a Distinguished Professor at the University of the Witwatersrand. He is also an Emeritus Professorial Fellow at New College, Oxford.
Limebeer is known for his contributions in engineering dynamics, with his contributions spanning electrical machines, robust control theory, and vehicle dynamics. He has published numerous peer-reviewed articles and books, including Linear Robust Control (with Michael Green), and Dynamics and Optimal Control of Road Vehicles (with Matteo Massaro). He is the recipient of two South African Institute of Electrical Engineers Prizes and award certificates, the University of Hong Kong William Mong Distinguished Lecture prize, and the 2019 Honeywell International Medal from the Institute of Measurement and Control. He is A1 rated with the South African National Research Foundation.
Limebeer is a Fellow of the Royal Academy of Engineering,
the Institute of Electrical Engineers, the South African Academy of Engineering, the City and Guilds of London Institute, and is a Life Fellow of the Institute of Electrical and Electronics Engineers.
Education
Limebeer obtained his B.Sc.in engineering from the University of the Witwatersrand in 1974 and then attended the University of Natal from 1975 to 1980, where he received his M.Sc. in engineering and a PhD degree. From 1980 to 1984, he was a post-doctoral fellow at the University of Cambridge. He earned a D.Sc. in engineering from the University of London in 1992, and a MA degree from the University of Oxford in 2009 (conferred by resolution).
Career
Limebeer joined Imperial College London in 1984 as a lecturer in the Department of Electrical and Electronic Engineering, was promoted to Reader in 1989, Professor in 1993 and served as Head of the department between 1999 and 2008. He was Professor of Control Engineering at the University of Oxford between 2008 and 2019, where he was also a Professorial Fellow at New College (Oxford). Since 2019, he has been an Emeritus Professor of Control Engineering at the University of Oxford and an Emeritus Professorial Fellow at New College. Following his retirement and return to South Africa, where he held emeritus positions at the University of Pretoria and the University of Johannesburg. Since 2021 he has been serving as a Distinguished Professor at the University of the Witwatersrand.
Limebeer has acted as an expert witness in several product liability, accident investigation, and patent cases. He has also consulted for several Formula One, MotoGP and NASCAR teams.
He has held a number of editorial positions, including Associate Editor for Systems and Control Letters, an Editor for Automatica, and serves as an Editorial Board Member for Multibody System Dynamics.
Research
Limebeer's research covers both theoretical and applied contributions to control engineering and dynamic systems. These include contributions to the understanding and prevention of subsynchronous resonance (SSR) in electrical machines, robust control and the dynamics of road vehicles including bicycles, motorcycles, and Formula One and NASCAR specification race cars.
Subsynchronous resonance (SSR)
SSR is an electro-mechanical resonance phenomenon that occurs in alternating-current (AC) machines when series capacitor compensation is included in the motor’s power supply. Limebeer’s work includes the design, operation, and limitations of passive-SSR suppression filters. He also explored SSR in induction motors with series capacitor compensated feeders, this work revealed improved starting time and voltage regulation, with unstable speed bands in both single-cage, and deep-bar motors.
Robust control
Robust control aims to achieve adequate performance and/or stability in the presence of modelling errors. Having considered the central problem of finding low-order robust controllers in the 1980s, Limebeer established that low-order controllers exist; and also contributed to the solution of the optimal case. In the periodically time-varying case, he explored the robust control of a satellite in a three-dimensional "halo" orbit and introduced a quantifiable robust stability margin that maintains the orbit while also ensuring robust stability. Much of this work is summarized in the textbook Linear Robust Control (with M. Green).
Vehicle dynamics
Another aspect of Limebeer's research is his work on motorcycle and race car dynamics. Working with Robin S. Sharp, he developed computational methods for finding vehicle models, that were later made into the commercial software product BikeSim. Prompted by the introduction in 2014 of fuel-saving regulations into Formula One, he studied the use of optimal control in closed-circuit racing, emphasizing the optimal deployment of limited fuel sources, later work focused on tyre management, and three-dimensional track modelling. In 2021, he focused on modifying his Formula One work for use on highly banked NASCAR ovals. Some of his vehicle dynamics work is included in the textbook Dynamics and Optimal Control of Road Vehicles.
Awards and honors
1992 – Elected Fellow, Institute of Electrical and Electronics Engineers
1994 – Elected Fellow, Institute of Electrical Engineers
1997 – Elected Fellow, Royal Academy of Engineering
2002 – Elected Fellow, City and Guilds of London Institute
2018 – Life Fellow, Institute of Electrical and Electronics Engineers
2019 – Fellow, South African Academy of Engineering
2019 – Honeywell International medal, Institute of Measurement and Control
2022 – A1 Rating, The NRF (South Africa)
Bibliography
Selected Books
Selected articles
References
Living people
1952 births
Electrical engineers
Fellows of the IEEE
Fellows of the Royal Academy of Engineering
University of the Witwatersrand alumni
University of Natal alumni
Academics of the University of Cambridge
Academics of the University of Oxford
Alumni of Michaelhouse | David Limebeer | [
"Engineering"
] | 1,125 | [
"Electrical engineering",
"Electrical engineers"
] |
74,714,251 | https://en.wikipedia.org/wiki/X-ray%20diffraction%20computed%20tomography | X-ray diffraction computed tomography is an experimental technique that combines X-ray diffraction with the computed tomography data acquisition approach. X-ray diffraction (XRD) computed tomography (CT) was first introduced in 1987 by Harding et al. using a laboratory diffractometer and a monochromatic X-ray pencil beam. The first implementation of the technique at synchrotron facilities was performed in 1998 by Kleuker et al.
X-ray diffraction computed tomography can be divided into two main categories depending on how the XRD data are being treated, specifically the XRD data can be treated either as powder diffraction or single crystal diffraction data and this depends on the sample properties. If the sample contains small and randomly oriented crystals, then it generates smooth powder diffraction "rings" when using a 2D area detector. If the sample contains large crystals, then it generates "spotty" 2D diffraction patterns. The latter can be performed using also a letterbox, cone and parallel X-ray beam and yields 2D or 3D images corresponding to maps of the crystallites or "grains" present in the sample and their properties, such as stress or strain. There exist several variations of this approach including 3DXRD, X-ray diffraction contrast tomography (DCT) and high energy X-ray diffraction microscopy (HEDM)
X-ray diffraction computed tomography, often abbreviated as XRD-CT, typically refers to the technique invented by Harding et al. which assumes that the acquired data are powder diffraction data. For this reason, it has also been mentioned as powder diffraction computed tomography and diffraction scattering computed tomography (DSCT), however they both refer to the same method.
Data acquisition
XRD-CT employs a monochromatic pencil beam scanning approach and captures the diffraction signal in transmission geometry, producing a diffraction projection dataset. In this setup, the sample moves along an axis perpendicular to the beam's direction. It is illuminated with a monochromatic finely collimated or focused "pencil" X-ray beam. A 2D area detector then records the scattered X-rays, optimizing for best counting statistics and speed. Typically, the translational scan's size surpasses the sample's diameter, ensuring its full coverage at all assessed angles. The size of the translation step is commonly aligned with the X-ray beam's horizontal size. In a perfect scenario for any pencil-beam scanning tomographic method, the measured angles should match the number of translation steps multiplied by π/2, adhering to the Nyquist sampling theorem. However, this number can often be reduced in practice be equal to the number of translation steps without substantially compromising the quality of reconstructed images. The usual angular range spans from 0 to π.
Data reconstruction
In most studies, the predominant data reconstruction approach is the 'reverse analysis' introduced by Bleuet et al. where each sinogram is treated independently yielding a new CT image. Most often the filtered back projection reconstruction algorithm is employed to reconstruct the XRD-CT images. The outcome is an image in which every pixel, or more accurately voxel, equates to a local diffraction pattern. The reconstructed data can also be seen as a stack of 2D square images, where each image corresponds to an X-ray scattering angle.
Reconstruction artefacts
XRD-CT makes the following assumptions:
The sample is small and there are no significant parallax artefacts in the acquired diffraction data; when this assumption is not valid the reconstructed patterns contain a wide range of artefacts, such as inaccurate peak positions, peak shapes and even arteficial peak splitting
The acquired XRD data are powder diffraction-like and do not contain spotty data
The sample is not strongly absorbing the X-rays and there are no significant self-absorption problems in the acquired data
The chemistry of the sample is not changing significantly during the XRD-CT scan
In practise, one or more of these assumptions are not valid and the data suffer from artefacts. There are strategies to remove or significantly all of these artefacts:
Rather than employing the filtered back projection reconstruction algorithm to reconstruct the XRD-CT images, it is possible to use another reconstruction approach, termed "Direct Least Squares Reconstruction" (DLSR) to perform simultaneously peak fitting and tomographic reconstruction which takes into account the geometry of the experimental setup and yields parallax artefact-free reconstructed images. Performing a 0 to 2π XRD-CT scan instead of 0 to π can lead to reconstructed patterns with accurate peak position but not peak shape.
Spotty 2D XRD data acquired during the XRD-CT scan lead to streak or line artefacts in the reconstructed XRD-CT data; it is possible to remove or suppress these artefacts by applying filters during the azimuthal integration of the raw 2D diffraction patterns
The data can be corrected for self-absorption artefacts using an X-ray absorption-contrast CT scan of the same sample.
If the solid-state chemistry of the sample is changing during the XRD-CT scan, then other data acquisition approaches can be employed that can improve the temporal resolution of the method, such as the interlaced approach
Data analysis
Analyzing the local diffraction patterns can range from basic single-peak sequential batch fitting to a comprehensive one-step full-profile analysis, known as 'Rietveld-CT' (Wragg et al., 2015 ). The latter method stands out for its efficiency over the typical sequential method since it shares global parameters across all local models. Examples of these parameters include zero error and instrumental broadening, which enhance the refinement process's stability. To elaborate, each voxel in the restructured images is made up of a local model (like multi-phase scale factors, lattice parameters, and crystallite sizes) tailored to match the corresponding local diffraction pattern. This implies that only the overarching parameters are consistent across local models. However, the application of Rietveld-CT has been limited to small images, specifically those of 60 × 60 voxels, with the feasibility for larger images hinging on the computer memory available. Most often though full profile analysis of the local diffraction patterns is performed on a pixel-by-pixel or line-by-line basis using conventional XRD data analysis methods, such LeBail, Pawley and Rietveld. All these methods employ fitting based on the restructured diffraction patterns. Another approach which is also computational expensive is the DLSR which performs the tomographic data reconstruction and peak fitting in a single step. Regardless of the chosen analytical method, the final output comprises images filled with localized physico-chemical information. Each physico-chemical image corresponds to the refined parameters present in the local models, which might include maps that correspond to scale factors, lattice parameters, and crystallite sizes.
See also
X-ray diffraction
computed tomography
powder diffraction
3DXRD
synchrotron
References
Laboratory techniques in condensed matter physics
X-ray crystallography
X-ray computed tomography
1987 introductions | X-ray diffraction computed tomography | [
"Physics",
"Chemistry",
"Materials_science"
] | 1,480 | [
"X-ray crystallography",
"Crystallography",
"Condensed matter physics",
"Laboratory techniques in condensed matter physics"
] |
74,714,260 | https://en.wikipedia.org/wiki/Wonder%20Drug%20%28book%29 | Wonder Drug: The Secret History of Thalidomide in America and Its Hidden Victims is a nonfiction book authored by Jennifer Vanderbes and published by Random House in 2023. It tells the story of how Frances Oldham Kelsey of the Food and Drug Administration (FDA) found flaws in thalidomide research. Contrary to the initial opinion that the FDA declined the drug a license for morning sickness in pregnancy and the US was therefore spared the thalidomide scandal, Vanderbes claims that the drug was still widely distributed there in the late 1950s and 1960s. As a result, many more babies were affected by phocomelia than originally believed.
References
External links
Books about drugs
21st-century books
Books about physicians
2023 non-fiction books
Pharmaceutical industry | Wonder Drug (book) | [
"Chemistry",
"Biology"
] | 154 | [
"Pharmaceutical industry",
"Pharmacology",
"Life sciences industry"
] |
74,714,401 | https://en.wikipedia.org/wiki/Aspergillus%20aeneus | Aspergillus aeneus is a species of fungus in the genus Aspergillus in the Aenei section of the subgenus Nidulantes
References
aeneus
Fungi described in 1954
Fungus species | Aspergillus aeneus | [
"Biology"
] | 44 | [
"Fungi",
"Fungus species"
] |
74,714,771 | https://en.wikipedia.org/wiki/Scruffy%20dome | A scruffy dome is a steel grille that is placed over the inlet of a manhole, and is usually dome shaped. They function as a way for stormwater to enter the pipe network without allowing larger debris in, such as people or animals. Scruffy domes are usually placed in parks and wetlands, and are usually made with galvanised steel.
References
Civil engineering | Scruffy dome | [
"Engineering"
] | 78 | [
"Construction",
"Civil engineering",
"Civil engineering stubs"
] |
74,716,961 | https://en.wikipedia.org/wiki/Amir%20Siraj | Amir Siraj (born in 2000) is an American astrophysicist, pianist, and science and music communicator.
Career
Astrophysics
Siraj earned bachelor's and master's degrees at Harvard University, and is currently pursuing his PhD at Princeton University. His research is primarily focused on interstellar objects, asteroids and comets, planetary system formation and evolution, supernovae, black holes, dark matter, and the search for life in the universe. Recently, he proposed the existence of unseen captured planets in the outer solar system. He discovered CNEOS 2014-01-08, the first known interstellar meteor, and as the director of interstellar object studies at the Galileo project, is involved with the search and discovery mission for interstellar objects. His research was named one of CNN's extraordinary cosmic revelations and moments in space exploration in 2022. He was the youngest scientist named to the Forbes 30 Under 30 list in 2021, and Astronomy magazine named him a rising star in astronomy in 2022. He also contributes to Scientific American.
Music
An active concert pianist, Siraj is a Young Steinway Artist and US Presidential Scholar in the Arts. He graduated from the New England Conservatory of Music with a master's degree in 2023. He has performed with Yo-Yo Ma at UNESCO and the United Nations General Assembly. He played at the Atlantic Council's Global Citizen Awards for Justin Trudeau, as well as at the GRAMMY Salute to Classical Music at Carnegie Hall, at The Cliburn and at the opening concert for the Swiss Alps Classics.
At the Aspen Center for Physics, he moderated a panel discussion that brought top composers and physicists together in conversation. In partnership with the National Park Foundation and From the Top, he established Music For The Parks.
References
Astrophysicists
2000 births
Living people
Harvard University alumni
Princeton University alumni
New England Conservatory alumni | Amir Siraj | [
"Physics"
] | 381 | [
"Astrophysicists",
"Astrophysics"
] |
74,717,534 | https://en.wikipedia.org/wiki/Health%20and%20Safety%20%28Safety%20Signs%20and%20Signals%29%20Regulations | The Health and Safety (Safety Signs and Signals) Regulations 1996 specify the safety signs within Great Britain, Northern Ireland has a similar law. It was issued as a transposition of the European directive 92/58/EEC and replaced The Safety Signs Regulations 1980. They consist of "traditional safety signs", such as prohibitory and warning signs, hand signals, spoken and acoustic signals and hazard marking.
Application
The regulations applies to the occupational health and safety within the territorial borders of Great Britain, also on offshore installations. It does not apply to the marking of dangerous goods and substances itself, only its storage or pipes, nor the regulation of road, rail, inland waterway, sea or air traffic, nor to signs used aboard of sea-going ships. For internal road traffic, traffic signs should be used.
The Regulations do not require the usage of safety signs and signals for third parties. However, it neither prohibits the usage for this purpose.
The Regulations require safety signage to be uniform and, as far as appropriate, without words, in order to be easily and fast understandable, without knowing the language.
Safety signs should only be used, if other measures of avoiding hazards failed. Also, if there is no risk, no safety signage should be used. Employees should regularly be instructed about the meaning of safety signs and signals. Employers are obligated to maintain the safety signage.
Relationship between the Regulations and BS EN ISO 7010
Minor differences between the prescribed signs and the installed signs are allowed, as long as the convey the same message. The Health and Safety Executive specifically allows the usage of BS EN ISO 7010 safety signs.
Structure
The Health and Safety (Safety Signs and Signals) Regulations 1996 consists of 8 articles and 3 schedules.
Schedule 1
Part I
As required in Annex I of the European directive 92/58/EEC, Schedule 1, Part I of the Reguations lays down a basic safety colour concept:
Part II
Schedule 1, Part II defines five types of signboards, as shown below. They are also covered by BS 5378, Part 1 and 3 from 1980 and 1982, which have been superseded by BS EN ISO 7010. Safety signs must contain only symbols, not text. However, supplementary text plates may be used. For fire exits, the running man symbol should be used. Fire safety signs in use before the Regulations were in place could be used until 24 December 1998.
Prohibitory signs
Warning signs
Mandatory signs
Emergency escape or first-aid signs
Fire-fighting signs
Part III
This part, Minimum requirements governing signs on containers and pipes, defines the marking for the transport or storage of dangerous material by pipes and in containers, originally within the scope of the European directives 67/548/EEC and 1999/45/EC, which are both replaced by Regulation (EC) No 1272/2008, the CLP Regulation. For marking, the warning signs of Part II should be used.
Part IV
The Minimum requirements for the identification and location of fire-fighting equipment specifies, that, additionally to the Fire-fighting signs of Part II, the equipment for fire-fighting and its location has to be marked red.
Part V
In this part, the Minimum requirements governing signs used for osbstacles and dangerous locations, and for marking traffic routes, requires hazardous places to be marked with either black and yellow or red and white markings. It also states that ways used for traffic have to be marked with either white or yellow stripes.
Part VI
Part VI, Minimum requirements for illuminated signs, requires illuminated signs to be single-coloured or to contain a symbol. If the latter is the case, it should comply with Part II. If a flashing light and a sound are used together, they have to be synchronized.
Part VII
This part, the Minimum requirements for acoustic signals, requires acoustic signals to be understandable and not harmful. If the acoustic signal is an fire alarm, it has to be continuing.
Part VIII
The Minimum requirements for verbal communication defines the use of language for safety purposes. It also defines coded words:
Part IX
Hand signals should only be given by one instructor. Other hand signals are also allowed, as specified in Schedule 2.
See also
Traffic Signs Regulations and General Directions, a similar Regulations for traffic signs
Globally Harmonized System of Classification and Labelling of Chemicals
References
External links
United Kingdom labour law
Statutory instruments of the United Kingdom
1996 in British law
Symbols
Pictograms | Health and Safety (Safety Signs and Signals) Regulations | [
"Mathematics"
] | 888 | [
"Symbols",
"Pictograms"
] |
74,717,897 | https://en.wikipedia.org/wiki/Cross-site%20leaks | Cross-site leaks, also known as XS-leaks, is an internet security term used to describe a class of attacks used to access a user's sensitive information on another website. Cross-site leaks allow an attacker to access a user's interactions with other websites. This can contain sensitive information. Web browsers normally stop other websites from seeing this information. This is enforced through a set of rules called the same-origin policy. Attackers can sometimes get around these rules, using a "cross-site leak". Attacks using a cross-site leak are often initiated by enticing users to visit the attacker's website. Upon visiting, the attacker uses malicious code on their website to interact with another website. This can be used by an attacker to learn about the user's previous actions on the other website. The information from this attack can uniquely identify the user to the attacker.
These attacks have been documented since 2000. One of the first research papers on the topic was published by researchers at Purdue University. The paper described an attack where the web cache was exploited to gather information about a website. Since then, cross-site leaks have become increasingly sophisticated. Researchers have found newer leaks targeting various web browser components. While the efficacy of some of these techniques varies, newer techniques are continually being discovered. Some older methods are blocked through updates to browsers. The introduction and removal of features on the Internet also lead to some attacks being rendered ineffective.
Cross-site leaks are a diverse form of attack, and there is no consistent classification of such attacks. Multiple sources classify cross-site leaks by the technique used to leak information. Among the well-known cross-site leaks are timing attacks, which depend on timing events within the web browser. Error events constitute another category, using the presence or absence of events to disclose data. Additionally, cache-timing attacks rely on the web cache to unveil information. Since 2023, newer attacks that use operating systems and web browser limits to leak information have also been found.
Before 2017, defending against cross-site leaks was considered to be difficult. This was because many of the information leakage issues exploited by cross-site leak attacks were inherent to the way websites worked. Most defences against this class of attacks have been introduced after 2017 in the form of extensions to the hypertext transfer protocol (HTTP). These extensions allow websites to instruct the browser to disallow or annotate certain kinds of stateful requests coming from other websites. One of the most successful approaches browsers have implemented is SameSite cookies. SameSite cookies allow websites to set a directive that prevents other websites from accessing and sending sensitive cookies. Another defence involves using HTTP headers to restrict which websites can embed a particular site. Cache partitioning also serves as a defence against cross-site leaks, preventing other websites from using the web cache to exfiltrate data.
Background
Web applications (web apps) have two primary components: a web browser and one or more web servers. The browser typically interacts with the servers via hyper text transfer protocol (HTTP) and WebSocket connections to deliver a web app. To make the web app interactive, the browser also renders HTML and CSS, and executes JavaScript code provided by the web app. These elements allow the web app to react to user inputs and run client-side logic. Often, users interact with the web app over long periods of time, making multiple requests to the server. To keep track of such requests, web apps often use a persistent identifier tied to a specific user through their current session or user account. This identifier can include details like age or access level, which reflect the user's history with the web app. If revealed to other websites, these identifiable attributes might deanonymize the user.
Ideally, each web app should operate independently without interfering with others. However, due to various design choices made during the early years of the web, web apps can regularly interact with each other. To prevent the abuse of this behavior, web browsers enforce a set of rules called the same-origin policy that limits direct interactions between web applications from different sources. Despite these restrictions, web apps often need to load content from external sources, such as instructions for displaying elements on a page, design layouts, and videos or images. These types of interactions, called cross-origin requests, are exceptions to the same-origin policy. They are governed by a set of strict rules known as the cross-origin resource sharing (CORS) framework. CORS ensures that such interactions occur under controlled conditions by preventing unauthorized access to data that a web app is not allowed to see. This is achieved by requiring explicit permission before other websites can access the contents of these requests.
Cross-site leaks allow attackers to circumvent the restrictions imposed by the same-origin policy and the CORS framework. They leverage information-leakage issues (side channels) that have historically been present in browsers. Using these side channels, an attacker can execute code that can infer details about data that the same origin policy would have shielded. This data can then be used to reveal information about a user's previous interactions with a web app.
Mechanism
To carry out a cross-site leak attack, an attacker must first study how a website interacts with users. They need to identify a specific URL that produces different Hyper Text Transfer Protocol (HTTP) responses based on the user's past actions on the site. For instance, if the attacker is trying to attack Gmail, they could try to find a search URL that returns a different HTTP response based on how many search results are found for a specific search term in a user's emails. Once an attacker finds a specific URL, they can then host a website and phish or otherwise lure unsuspecting users to the website. Once the victim is on the attacker's website, the attacker can use various embedding techniques to initiate cross-origin HTTP requests to the URL identified by the attacker. However, since the attacker is on a different website, the same-origin policy imposed by the web browser will prevent the attacker from directly reading any part of the response sent by the vulnerable website.
To circumvent this security barrier, the attacker can use browser-leak methods, to distinguish subtle differences between different responses. Browser leak methods are JavaScript, CSS or HTML snippets that leverage long-standing information leakage issues (side channels) in the web browser to reveal specific characteristics about a HTTP response. In the case of Gmail, the attacker could use JavaScript to time how long the browser took to parse the HTTP response returned by the search result. If the time taken to parse the response returned by the endpoint was low, the attacker could infer that there were no search results for their query. Alternatively, if the site took longer, the attacker could infer that multiple search results were returned. The attacker can subsequently use the information gained through these information leakages to exfiltrate sensitive information, which can be used to track and deanonymize the victim. In the case of Gmail, the attacker could make a request to the search endpoint with a query and subsequently measure the time the query took to figure out whether or not the user had any emails containing a specific query string. If a response takes very little time to be processed, the attacker can assume that no search results were returned. Conversely, if a response takes a large amount amount of time to be processed, the attacker infer that a lot of search results were returned. By making multiple requests, an attacker could gain significant insight into the current state of the victim application, potentially revealing private information of a user, helping launch sophisticated spamming and phishing attacks.
History
Cross-site leaks have been known about since 2000; research papers dating from that year from Purdue University describe a theoretical attack that uses the HTTP cache to compromise the privacy of a user's browsing habits. In 2007, Andrew Bortz and Dan Boneh from Stanford University published a white paper detailing an attack that made use of timing information to determine the size of cross-site responses. In 2015, researchers from Bar-Ilan University described a cross-site search attack that used similar leaking methods. The attack employed a technique in which the input was crafted to grow the size of the responses, leading to a proportional growth in the time taken to generate the responses, thus increasing the attack's accuracy.
Independent security researchers have published blog posts describing cross-site leak attacks against real-world applications. In 2009, Chris Evans described an attack against Yahoo! Mail via which a malicious site could search a user's inbox for sensitive information. In 2018, Luan Herrara found a cross-site leak vulnerability in Google's Monorail bug tracker, which is used by projects like Chromium, Angle, and Skia Graphics Engine. This exploit allowed Herrara to exfiltrate data about sensitive security issues by abusing the search endpoint of the bug tracker. In 2019, Terjanq, a Polish security researcher, published a blog post describing a cross-site search attack that allowed them to exfiltrate sensitive user information across high-profile Google products.
As part of its increased focus on dealing with security issues that depend on misusing long-standing web-platform features, Google launched XSLeaks Wiki in 2020. The initiative aimed to create an open-knowledge database about web-platform features that were being misused and analysing and compiling information about cross-site leak attacks.
Since 2020, there has been some interest among the academic security community in standardizing the classification of these attacks. In 2020, Sudhodanan et al. were among the first to systematically summarize previous work in cross-site leaks, and developed a tool called BASTA-COSI that could be used to detect leaky URLs. In 2021, Knittel et al. proposed a new formal model to evaluate and characterize cross-site leaks, allowing the researchers to find new leaks affecting several browsers. In 2022, Van Goethem et al. evaluated currently available defences against these attacks and extended the existing model to consider the state of browser components as part of the model. In 2023, a paper published by Rautenstrauch et al. systemizing previous research into cross-site leaks was awarded the Distinguished Paper Award at the IEEE Symposium on Security and Privacy.
Threat model
The threat model of a cross-site leak relies on the attacker being able to direct the victim to a malicious website that is at least partially under the attacker's control. The attacker can accomplish this by compromising a web page, by phishing the user to a web page and loading arbitrary code, or by using a malicious advertisement on an otherwise-safe web page.
Cross site leak attacks require that the attacker identify at least one state-dependent URL in the victim app for use in the attack app. Depending on the victim app's state, this URL must provide at least two responses. A URL can be crafted, for example, by linking to content that is only accessible to the user if they are logged into the target website. Including this state-dependent URL in the malicious application will initiate a cross-origin request to the target app. Because the request is a cross-origin request, the same-origin policy prevents the attacker from reading the contents of the response. Using a browser-leak method, however, the attacker can query specific identifiable characteristics of the response, such as the HTTP status code. This allows the attacker to distinguish between responses and gain insight into the victim app's state.
While every method of initiating a cross-origin request to a URL in a web page can be combined with every browser-leak method, this does not work in practice because dependencies exist between different inclusion methods and browser leaks. Some browser-leak methods require specific inclusion techniques to succeed. For example, if the browser-leak method relies on checking CSS attributes such as the width and height of an element, the inclusion technique must use an HTML element with a width and height property, such as an image element, that changes when a cross-origin request returns an invalid or a differently sized image.
Types
Cross-site leaks comprise a highly varied range of attacks for which there is no established, uniform classification. However, multiple sources typically categorized these attacks by the leaking techniques used during an attack. , researchers have identified over 38 leak techniques that target components of the browser. New techniques are typically discovered due to changes in web platform APIs, which are JavaScript interfaces that allow websites to query the browser for specific information. Although the majority of these techniques involve directly detecting state changes in the victim web app, some attacks also exploit alterations in shared components within the browser to indirectly glean information about the victim web app.
Timing attacks
Timing attacks rely on the ability to time specific events across multiple responses. These were discovered by researchers at Stanford University in 2007, making them one of the oldest-known types of cross-site leak attacks.
While initially used only to differentiate between the time it took for a HTTP request to resolve a response, research performed after 2007 has demonstrated the use of this leak technique to detect other differences across web-app states. In 2017, Vila et al. showed timing attacks could infer cross-origin execution times across embedded contexts. This was made possible by a lack of site isolation features in contemporaneous browsers, which allowed an attacking website to slow down and amplify timing differences caused by differences in the amount of JavaScript being executed when events were sent to a victim web app.
In 2021, Knittel et al. showed the Performance API could leak the presence or absence of redirects in responses. This was possible due to a bug in the Performance API that allowed the amount of time shown to the user to be negative when a redirect occurred. Google Chrome subsequently fixed this bug. In 2023, Snyder et al. showed timing attacks could be used to perform pool-party attacks in which websites could block shared resources by exhausting their global quota. By making the victim web app execute JavaScript that used these shared resources and then timing how long these executions took, the researchers were able to reveal information about the state of a web app.
Error events
Error events is a leak technique that allows an attacker to distinguish between multiple responses by registering error-event handlers and listening for events through them. Due to their versatility and ability to leak a wide range of information, error events are considered a classic cross-site leak vector.
One of the most-common use cases for error events in cross-site leak attacks is determining HTTP responses by attaching the event handlers onload and onerror event handlers to a HTML element and waiting for specific error events to occur. A lack of error events indicates no HTTP errors occurred. In contrast, if the handler onerror is triggered with a specific error event, the attacker can use that information to distinguish between HTTP content types, status codes and media-type errors. In 2019, researchers from TU Darmstadt showed this technique could be used to perform a targeted deanonymization attack against users of popular web services such as Dropbox, Google Docs, and GitHub that allow users to share arbitrary content with each other.
Since 2019, the capabilities of error events have been expanded. In 2020, Janc et al. showed by setting the redirect mode for a fetch request to manual, a website could leak information about whether a specific URL is a redirect. Around the same time, Jon Masas and Luan Herrara showed by abusing URL-related limits, an attacker could trigger error events that could be used to leak redirect information about URLs. In 2021, Knittel et al. showed error events that are generated by a subresource integrity check, a mechanism that is used to confirm a sub-resource a website loads has not been changed or compromised, could also be used to guess the raw content of an HTTP response and to leak the content-length of the response.
Cache-timing attacks
Cache-timing attacks rely on the ability to infer hits and misses in shared caches on the web platform. One of the first instances of a cache-timing attack involved the making of a cross-origin request to a page and then probing for the existence of the resources loaded by the request in the shared HTTP and the DNS cache. The paper describing the attack was written by researchers at Purdue University in 2000, and describes the attack's ability to leak a large portion of a user's browsing history by selectively checking if resources that are unique to a web page have been loaded.
This attack has become increasingly sophisticated, allowing the leakage of other types of information. In 2014, Jia et al. showed this attack could geo-locate a person by measuring the time it takes for the localized domain of a group of multinational websites to load. In 2015, Van Goethem et al. showed using the then-newly introduced application cache, a website could instruct the browser to disregard and override any caching directive the victim website sends. The paper also demonstrated a website could gain information about the size of the cached response by timing the cache access.
Global limits
Global limits, which are also known as pool-party attacks, do not directly rely on the state of the victim web app. This cross-site leak was first discovered by Knittel et al. in 2020 and then expanded by Snyder et al. in 2023. The attack to abuses global operating systems or hardware limitations to starve shared resources. Global limits that could be abused include the number of raw socket connections that can be registered and the number of service workers that can be registered. An attacker can infer the state of the victim website by performing an activity that triggers these global limits and comparing any differences in browser behaviour when the same activity is performed without the victim website being loaded. Since these types of attacks typically also require timing side channels, they are also considered timing attacks.
Other techniques
In 2019, Gareth Heyes discovered that by setting the URL hash of a website to a specific value and subsequently detecting whether a loss of focus on the current web page occurred, an attacker could determine the presence and position of elements on a victim website. In 2020, Knittel et al. showed an attacker could leak whether or not a Cross-Origin-Opener-Policy header was set by obtaining a reference to the window object of a victim website by framing the website or by creating a popup of the victim website. Using the same technique of obtaining window references, an attacker could also count the number of frames a victim website had through the window.length property.
While newer techniques continue to be found, older techniques for performing cross-site leaks have become obsolete due to changes in the World Wide Web Consortium (W3C) specifications and updates to browsers. In December 2020, Apple updated its browser Safari's Intelligent Tracking Prevention (ITP) mechanism, rendering a variety of cross-site leak techniques researchers at Google had discovered ineffective. Similarly, the widespread introduction of cache partitioning in all major browsers in 2020 has reduced the potency of cache-timing attacks.
Example
The example of a Python-based web application with a search endpoint interface implemented using the following Jinja template demonstrates a common scenario of how a cross-site leak attack could occur.
<html lang="en">
<body>
<h2>Search results</h2>
{% for result in results %}
<div class="result">
<img src="//cdn.com/result-icon.png" />
{% result.description %}
</div>
{% endfor %}
</body>
</html>
This code is a template for displaying search results on a webpage. It loops through a collection of results provided by a HTTP server backend and displays each result along with its description inside a structured div element alongside an icon loaded from a different website. The underlying application authenticates the user based on cookies that are attached to the request and performs a textual search of the user's private information using a string provided in a GET parameter. For every result returned, an icon that is loaded from a Content Delivery Network (CDN) is shown alongside the result.
This simple functionality is vulnerable to a cross-leak attack, as shown by the following JavaScript snippet.
let icon_url = 'https://cdn.com/result-icon.png';
iframe.src = 'https://service.com/?q=password';
iframe.onload = async () => {
const start = performance.now();
await fetch(icon_url);
const duration = performance.now() - start;
if (duration < 5) // loaded resource from cache
console.log('Query had results');
else
console.log('No results for query parameter');
};This JavaScript snippet, which can be embedded in an attacker-controlled web app, loads the victim web app inside an iframe, waits for the document to load and subsequently requests the icon from the CDN. The attacker can determine whether the icon was cached by timing its return. Because the icon will only be cached if and only if the victim app returns at least one result, the attacker can determine whether the victim app returned any results for the given query.
Defences
Before 2017, websites could defend against cross-site leaks by ensuring the same response was returned for all application states, thwarting the attacker's ability to differentiate the requests. This approach was infeasible for any non-trivial website. The second approach was to create session-specific URLs that would not work outside a user's session. This approach limited link sharing, and was impractical.
Most modern defences are extensions to the HTTP protocol that either prevent state changes, make cross-origin requests stateless, or completely isolate shared resources across multiple origins.
Isolating shared resources
One of the earliest methods of performing cross-site leaks was using the HTTP cache, an approach that relied on querying the browser cache for unique resources a victim's website might have loaded. By measuring the time it took for a cross-origin request to resolve an attacking website, one could determine whether the resource was cached and, if so, the state of the victim app. , most browsers have implemented HTTP cache partitioning, drastically reducing the effectiveness of this approach. HTTP cache partitioning works by multi-keying each cached request depending on which website requested the resource. This means if a website loads and caches a resource, the cached request is linked to a unique key generated from the resource's URL and that of the requesting website. If another website attempts to access the same resource, the request will be treated as a cache miss unless that website has previously cached an identical request. This prevents an attacking website from deducing whether a resource has been cached by a victim website.
Another, more developer-oriented feature that allows the isolation of execution contexts includes the Cross-Origin-Opener-Policy (COOP) header, which was originally added to address Spectre issues in the browser. It has proved useful for preventing cross-site leaks because if the header is set with a same-origin directive as part of the response, the browser will disallow cross-origin websites from being able to hold a reference to the defending website when it is opened from a third-party page.
As part of an effort to mitigate cross-site leaks, the developers of all major browsers have implemented storage partitioning, allowing all shared resources used by each website to be multi-keyed, dramatically reducing the number of inclusion techniques that can infer the states of a web app.
Preventing state changes
Cross-site leak attacks depend on the ability of a malicious web page to receive cross-origin responses from the victim application. By preventing the malicious application from being able to receive cross-origin responses, the user is no longer in danger of having state changes leaked. This approach is seen in defences such as the deprecated X-Frame-Options header and the newer frame-ancestors directive in Content-Security Policy headers, which allow the victim application to specify which websites can include it as an embedded frame. If the victim app disallows the embedding of the website in untrusted contexts, the malicious app can no longer observe the response to cross-origin requests made to the victim app using the embedded frame technique.
A similar approach is taken by the Cross-Origin Resource Blocking (CORB) mechanism and the Cross-Origin-Resource-Policy (CORP) header, which allows a cross-origin request to succeed but blocks the loading of the content in third-party websites if there is a mismatch between the content type that was expected and that which was received. This feature was originally introduced as part of a series of mitigations against the Spectre vulnerability but it has proved useful in preventing cross-origin leaks because it blocks the malicious web page from receiving the response and thus inferring state changes.
Making cross-origin requests stateless
One of the most-effective approaches to mitigating cross-site leaks has been the use of the SameSite parameter in cookies. Once set to Lax or Strict, this parameter prevents the browser from sending cookies in most third-party requests, effectively making the request stateless. Adoption of Same-Site cookies, however, has been slow because it requires changes in the way many specialized web servers, such as authentication providers, operate. In 2020, the makers of the Chrome browser announced they would be turning on SameSite=Lax as the default state for cookies across all platforms. Despite this, there are still cases in which SameSite=Lax cookies are not respected, such as Chrome's LAX+POST mitigation, which allows a cross-origin site to use a SameSite=Lax cookie in a request if and only if the request is sent while navigating the page and it occurs within two minutes of the cookie being set. This has led to bypasses and workarounds against the SameSite=Lax limitation that still allow cross-site leaks to occur.
Fetch metadata headers, which include the Sec-Fetch-Site, Sec-Fetch-Mode, Sec-Fetch-User and Sec-Fetch-Dest header, which provide information about the domain that initiated the request, details about the request's initiation, and the destination of the request respectively to the defending web server, have also been used to mitigate cross-site leak attacks. These headers allows the web server to distinguish between legitimate third-party, same-site requests and harmful cross-origin requests. By discriminating between these requests, the server can send a stateless response to malicious third-party requests and a stateful response to routine same-site requests. To prevent the abusive use of these headers, a web app is not allowed to set these headers, which must only be set by the browser.
See also
Cross origin resource sharing
Same origin policy
Cross-site scripting
Cross-site request forgery
References
Notes
Citations
Sources
Further reading
External links
Web security exploits
Internet privacy
Hacking (computer security)
Web browsers
Client-side web security exploits
Side-channel attacks | Cross-site leaks | [
"Technology"
] | 5,643 | [
"Computer security exploits",
"Web security exploits"
] |
74,718,016 | https://en.wikipedia.org/wiki/Carcinomyces%20polyporinus | Carcinomyces polyporinus is a species of fungus in the class Tremellomycetes. It is a parasite, growing in the hymenia of various poroid fungi, particularly species of Postia. Microscopically, it resembles a species of Tremella, but DNA research indicates that it belongs in a different family, the Carcinomycetaceae. It was first described by British mycologist Derek Reid from Scotland. It has also been recorded in continental Europe and North America.
References
Tremellomycetes
Taxa named by Derek Reid
Fungi described in 1970
Fungus species | Carcinomyces polyporinus | [
"Biology"
] | 121 | [
"Fungi",
"Fungus species"
] |
62,313,886 | https://en.wikipedia.org/wiki/MOWChIP-seq | MOWChIP-seq (Microfluidic Oscillatory Washing–based Chromatin ImmunoPrecipitation followed by sequencing) is a microfluidic technology used in molecular biology for profiling genome-wide histone modifications and other molecular bindings using as few as 30-100 cells per assay. MOWChIP-seq is a special type of ChIP-seq assay designed for low-input and high-throughput assays. The overall process of MOWChIP-seq is similar to that of conventional ChIP-seq assay except that the chromatin immunoprecipitation (ChIP) and washing steps occur in a small microfluidic chamber. MOWChIP-seq takes advantage of the capability of microfluidics for manipulating micrometer-sized beads. In the process, a packed bed of beads is formed to drastically increase the adsorption efficiency of chromatin fragments. An automated oscillatory washing is then used to remove nonspecific binding and impurity from the bead surface. Initial version of MOWChIP device contained only one microfluidic chamber. In the more recent demonstration, semi-automated MOWChIP device for running 8 parallel assays was presented.
Applications
MOWChIP-seq is enhanced and low-input ChIP-seq thus it applies to all molecular biology that can be probed using ChIP-seq. This includes analysis of histone modifications, RNA pol II binding, and transcription factor binding. Published MOWChIP-seq results include studies of various histone marks (H3K4me3, H3K27ac, H3K27me3, H3K9me3, H3K36me3, and H3K79me2)1,2.
Workflow of MOWChIP-seq
MOWChIP-seq requires a microfluidic system for running the ChIP and washing steps in a semi-automated fashion. The preparation of chromatin fragments from cells or nuclei and sequencing library using ChIP DNA is largely the same as in conventional ChIP-seq assays.
Data analysis
MOWChIP-seq produces ChIP-seq data with high quality that is comparable to those produced using large quantity of cells. Thus the data analysis is mostly identical to the analytical processes used in common ChIP-seq data analysis.
References
Biomedical engineering
Microfluidics | MOWChIP-seq | [
"Materials_science",
"Engineering",
"Biology"
] | 505 | [
"Biological engineering",
"Microfluidics",
"Microtechnology",
"Biomedical engineering",
"Medical technology"
] |
62,314,534 | https://en.wikipedia.org/wiki/Substrate%20presentation | In molecular biology, substrate presentation is a biological process that activates a protein. The protein is sequestered away from its substrate and then activated by release and exposure to its substrate. A substrate is typically the substance on which an enzyme acts but can also be a protein surface to which a ligand binds. In the case of an interaction with an enzyme, the protein or organic substrate typically changes chemical form. Substrate presentation differs from allosteric regulation in that the enzyme need not change its conformation to begin catalysis. Substrate presentation is best described for domain partitioning at nanoscopic distances (<100 nm).
Examples
Amyloid precursor protein
Amyloid precursor protein (APP) is cleaved by beta and gamma secretase to yield a 40-42 amino acid peptide responsible for amyloid plaques associated with Alzheimer's disease. The secretase enzymes are regulated by substrate presentation. The substrate APP is palmitoylated and moves in and out of GM1 lipid rafts in response to astrocyte cholesterol. Cholesterol delivered by apolipoprotein E (ApoE) drives APP to associate with GM1 lipid rafts. When cholesterol is low, the protein traffics to the disordered region and is cleaved by alpha secretase to produce a non-amylogenic product. The enzymes do not appear to respond to cholesterol, only the substrate moves.
Hydrophobicity drives the partitioning of molecules. In the cell, this gives rise to compartmentalization within the cell and within cell membranes. For lipid rafts, palmitoylation regulates raft affinity for the majority of integral raft proteins. Raft regulation is regulated by cholesterol signaling and spatial biology
Phospholipase D2
(PLD2) is a well-defined example of an enzyme activated by substrate presentation. The enzyme is palmitoylated causing the enzyme to traffic to GM1 lipid domains or "lipid rafts". The substrate of phospholipase D is phosphatidylcholine (PC) which is unsaturated and is of low abundance in lipid rafts. PC localizes to the disordered region of the cell along with the polyunsaturated lipid phosphatidylinositol 4,5-bisphosphate (PIP2). PLD2 has a PIP2 binding domain. When PIP2 concentration in the membrane increases, PLD2 leaves the GM1 domains and associates with PIP2 domains where it then gains access to its substrate PC and commences catalysis based on substrate presentation. Presumably, the enzyme is capable of catalyzing a reaction in a lipid raft but lacks a substrate for activity.
Inflammation
(ADAM17), also called TACE, is sequestered into lipid rafts away from its substrate, membrane bound tumor necrosis factor (mTNF). Cholesterol causes mTNF to cluster with ADAM17 in lipid rafts and shed soluble TNF (sTNF) which is an inflammatory cytokine.
Kinase Signaling
Receptor Tyrosine Kinases are cell surface receptors that bind to various polypeptide growth factors, cytokines, and hormones. Activation of RTKs is driven by palmitoylation and dimerization, a process facilitated by cholesterol within lipid rafts. Once dimerized, the receptor undergoes autophosphorylation, which triggers a subsequent phosphorylation cascade. This is a specific case where the substrate and the enzyme are the same molecule.
Protein Kinase C (PKC) is a class of enzymes that phosphorylates proteins. Its substrates are typically on the membrane surface where the enzyme is recruited by the lipid diacylglycerol. Thus a portion of PKC activation is through substrate presentation, i.e., by localization with its substrate on the membrane.
SARS-CoV-2
(Furin) (producing cell, replication). When cells are loaded with cholesterol furin traffics to GM1 lipid rafts where it is localized with the palmitoylated spike protein of SARS-CoV-2 and primes it for viral entry.
(ACE2) (target Cell, viral entry), the receptor for SARS-CoV-2 ACE2 traffics SARS-CoV-2 to GM1 lipid rafts where it is endocytosed and exposed to cathepsin for cleavage and optimal cells fusion. In low cholesterol ACE2 traffics the virus to TMPRSS2 which also cleaves and allows viral entry but through a putative surface mechanism that is much less efficient. The sensitivity of ACE2 to cholesterol is thought to contribute to less severe COVID19 symptoms in children.
Mechanisms of activation
Sequestration
Sequestration is the process of moving a molecule to a lipid raft. Within the plasma membrane, sequestration is primarily driven by packing of saturated lipid with cholesterol or phase separation at very small distances (< 100 nm). At a macroscopic level, organelles and vesicle can limit access of an enzyme with to substrate.
Sequestration can both elevate and reduce the concentration of a protein in proximity to its substrate. When the substrate is present within a lipid raft, sequestration leads to an increased concentration of the protein near the substrate. Conversely, if the substrate is excluded from a lipid raft, sequestration results in decreased interaction between the protein and the substrate, as seen with PLD2.
Either the substrate of the enzyme can move. Movement is typically the disruption of palmitate mediated localization or organelle trafficking. For proteins that are both palmitoylated and bind PIP2, increasing the concentration of PIP2 favors trafficking of the enzyme out of lipid rafts to PIP2. PIP2 is primarily polyunsaturated which causes the lipid to localize away from lipid rafts and allows the PIP2 to oppose palmitate mediated localization.
Regulation
Cholesterol
Cholesterol and polyunsaturated fatty acids (PUFAs) regulate lipid raft formation, hence the biological function of rafts. When saturated lipids and cholesterol increase in the membrane, lipid rafts increase their affinity for palmitoylated proteins. PUFAs have the opposite effect, they fluidize the membrane.
PUFAs
PUFAs may also increase the concentration of signaling lipids. The arachidonic acid, a very common PUFA in the brain, incorporates into PC and PIP2. Arachidonyl PC is a preferred substrate of PLD likely increasing the amount of PA in a cell. Regulation of raft function by cholesterol effectively regulates substrate presentation and the many palmitoylated proteins that utilize substrate presentation as a mechanism of activation. While speculative, the profound effect of cholesterol and PUFAs on human health is likely through physiological regulation of lipid raft function in cells.
Role in biology
Mechanosensation
Mechanical force (shear or swell) can independently disrupt the packing and resultant affinity of palmitate to lipid rafts. This disruption also causes PLD2 to favor trafficking to PIP2 domains. The mechanosensitive ion channel TREK-1 is released from cholesterol dependent lipid rafts in response to mechanical force. This has the effect of dampening pain.
Anaesthesia
Membrane-mediated anesthesia employs substrate presentation. General anesthetics propofol and inhaled anesthetics xenon, chloroform, isoflurane, diethyl ether disrupt lipid raft function and palmitate mediated localization of PLD2 to lipid rafts. Activation of PLD then activates TREK-1 channels. The membrane mediated PLD2 activation could be transferred to an anesthetic insensitive homolog TRAAK, rending the channel anesthetic sensitive.
References
Biological processes | Substrate presentation | [
"Biology"
] | 1,641 | [
"nan"
] |
62,314,663 | https://en.wikipedia.org/wiki/List%20of%20College%20and%20University%20Agricultural%20Engineering%20Departments | Below is a listing of known academic programs that offer bachelor's degrees (B.S. or B.S.E. or B.E / B.Tech) in what ABET terms "Agricultural Engineering", "Biosystems Engineering", "Biological Engineering", or similarly named programs. ABET accredits college and university programs in the disciplines of applied science, computing, engineering, and engineering technology.
The Americas
North America
Mexico, Central and South America
Europe
Asia
Oceania
Africa
External links
Bureau of Labor Statistics, Agricultural Engineering Education
https://www.bls.gov/ooh/architecture-and-engineering/agricultural-engineers.htm#tab-4
Engineering education
Agricultural Engineering Departments | List of College and University Agricultural Engineering Departments | [
"Engineering"
] | 146 | [
"Lists of engineering schools",
"Engineering universities and colleges"
] |
62,317,758 | https://en.wikipedia.org/wiki/Project%20Nightingale | Project Nightingale is a data storage and processing project by Google Cloud and Ascension, a Catholic health care system comprising a chain of 2,600 hospitals, doctors' offices and other related facilities, in 21 states, with tens of millions of patient records available for processing health care data. Ascension is one of the largest health-care systems in the United States with comprehensive and specific health care information of millions who are part of its system. The project is Google's attempt to gain a foothold into the healthcare industry on a large scale. Amazon, Microsoft and Apple Inc. are also actively advancing into health care, but none of their business arrangements are equal in scope to Project Nightingale.
History
In early 2019, Ascension began talks with Google about developing health aggregation software to store and search medical records. The two companies signed a Health Insurance Portability and Accountability Act (HIPAA) business associate agreement, which would allow Ascension to transfer patient data to Google Cloud, and would bar Google from using this data for purposes other than providing services to Ascension. Google first mentioned its project with Ascension in a July 2019 earnings call, which said the partnership was meant to "improve the healthcare experience and outcomes."
The Wall Street Journal first reported on "Project Nightingale" on November 11, 2019, writing that doctors and patients had not been notified of the project and that 150 Google employees had access to patient data. Google Health chief David Feinberg responded to the report in a blog post, saying all employees with access to protected health information went through medical ethics training and were approved by Ascension.
The project raised privacy fears because of Google's involvement in other privacy controversies, like DeepMind's medical data-sharing controversy and a lawsuit against Google and the University of Chicago Medical Center for allegedly processing identifying medical records. Google Cloud executive Tariq Shaukat wrote that patient data gathered from the project "cannot and will not be combined with any Google consumer data."
Types of data
The data sharing includes patient names and their dates of birth, along with doctor diagnoses, lab results, and hospitalization records, amounting to access to complete electronic health records. Also included in the data sharing are addresses of the patient, family members, allergies, immunizations, radiology scans, medications, and medical conditions. After the patient checks in to the doctor's office, or hospital, or senior center - the doctor and nurse examination results are entered into a computer and uploaded to Google's cloud servers. At this point, the system is then used to suggest treatment plans, recommend replacement or removal of a doctor from the patient's health-care team, and administer policies on narcotics. Ascension, the company sharing data with Google, may also vary their billing according to treatment or procedures.
Investigations
Soon after The Wall Street Journal reported on Project Nightingale, The Guardian published an account from an anonymous whistleblower who worked on Project Nightingale. This person who raised concerns that patients could not opt in or out of having their records stored on Google's servers, and that the project may not be HIPAA compliant.
The United States Department of Health and Human Services (HHS) launched an inquiry into Google's partnership with Ascension. The investigation will be run by HHS' Office of Civil Rights. Director Roger Severino said, his office "would like to learn more information about this mass collection of individuals' medical records with respect to the implications for patient privacy under [the Health Insurance Portability and Accountability Act of 1996 or HIPAA]."
See also
Google Health
References
External links
Our Partnership with Ascension, Google Cloud blog post and FAQ
2019 establishments in the United States
2019 controversies in the United States
Healthcare in the United States
Catholic health care
Code names
Google Cloud
Electronic health records
Medical controversies in the United States
Projects established in 2019
Databases in the United States | Project Nightingale | [
"Technology"
] | 771 | [
"Electronic health records",
"Information technology"
] |
62,318,997 | https://en.wikipedia.org/wiki/H3K79me2 | H3K79me2 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the di-methylation at the 79th lysine residue of the histone H3 protein. H3K79me2 is detected in the transcribed regions of active genes.
Nomenclature
H3K79me2 indicates dimethylation of lysine 79 on histone H3 protein subunit:
Lysine methylation
This diagram shows the progressive methylation of a lysine residue. The di-methylation (third from left) denotes the methylation present in H3K79me2.
Histone modifications
The genomic DNA of eukaryotic cells is wrapped around special protein molecules known as Histones. The complexes formed by the looping of the DNA are known as chromatin. The basic structural unit of chromatin is the nucleosome: this consists of the core octamer of histones (H2A, H2B, H3 and H4) as well as a linker histone and about 180 base pairs of DNA. These core histones are rich in lysine and arginine residues. The carboxyl (C) terminal end of these histones contribute to histone-histone interactions, as well as histone-DNA interactions. The amino (N) terminal charged tails are the site of the post-translational modifications, such as the one seen in H3K36me3.
Epigenetic implications
The post-translational modification of histone tails by either histone modifying complexes or chromatin remodelling complexes are interpreted by the cell and lead to complex, combinatorial transcriptional output. It is thought that a Histone code dictates the expression of genes by a complex interaction between the histones in a particular region. The current understanding and interpretation of histones comes from two large scale projects: ENCODE and the Epigenomic roadmap. The purpose of the epigenomic study was to investigate epigenetic changes across the entire genome. This led to chromatin states which define genomic regions by grouping the interactions of different proteins and/or histone modifications together.
Chromatin states were investigated in Drosophila cells by looking at the binding location of proteins in the genome. Use of ChIP-sequencing revealed regions in the genome characterised by different banding. Different developmental stages were profiled in Drosophila as well, an emphasis was placed on histone modification relevance. A look in to the data obtained led to the definition of chromatin states based on histone modifications.
The human genome was annotated with chromatin states. These annotated states can be used as new ways to annotate a genome independently of the underlying genome sequence. This independence from the DNA sequence enforces the epigenetic nature of histone modifications. Chromatin states are also useful in identifying regulatory elements that have no defined sequence, such as enhancers. This additional level of annotation allows for a deeper understanding of cell specific gene regulation.
Three forms of H3K79 methylation (H3K79me1; H3K79me2; H3K79me3) are catalyzed by DOT1 in yeast or DOT1L in mammals. H3K79 methylation participates in the DNA damage response and has multiple roles in nucleotide excision repair and sister chromatid recombinational repair.
H3K79 dimethylation has been detected in the transcribed regions of active genes.
Methods
The histone mark H3K36me3 can be detected in a variety of ways:
1. Chromatin Immunoprecipitation Sequencing (ChIP-sequencing) measures the amount of DNA enrichment once bound to a targeted protein and immunoprecipitated. It results in good optimization and is used in vivo to reveal DNA-protein binding occurring in cells. ChIP-Seq can be used to identify and quantify various DNA fragments for different histone modifications along a genomic region.
2. Micrococcal Nuclease sequencing (MNase-seq) is used to investigate regions that are bound by well positioned nucleosomes. Use of the micrococcal nuclease enzyme is employed to identify nucleosome positioning. Well positioned nucleosomes are seen to have enrichment of sequences.
3. Assay for transposase accessible chromatin sequencing (ATAC-seq) is used to look in to regions that are nucleosome free (open chromatin). It uses hyperactive Tn5 transposon to highlight nucleosome localisation.
See also
Histone code
Histone methylation
Histone methyltransferase
Methyllysine
References
Epigenetics
Post-translational modification | H3K79me2 | [
"Chemistry"
] | 1,010 | [
"Post-translational modification",
"Gene expression",
"Biochemical reactions"
] |
62,319,439 | https://en.wikipedia.org/wiki/Jilly%20Juice | Jilly Juice is a quack pseudomedicine in the form of a fermented drink that is falsely claimed by its proponents to be able to cure an assortment of conditions, including cancer and autism spectrum disorders, as well as regenerate missing limbs, reverse the effects of aging, and "cure" homosexuality. No studies have proven any of these claims, nor has the Food and Drug Administration (FDA) approved the recipe. The juice, composed of water, salt, and fermented cabbage or kale, is falsely claimed to expunge Candida (a yeast) and parasitic worms. Scientific evidence has shown that this treatment is not only ineffective, but is also toxic with potentially deadly adverse effects.
Jilly Juice was conceived by Jillian Mai Thi Epperly, who has no medical or scientific background. She has garnered media scrutiny for her baseless claims that Jilly Juice can help treat medical conditions, and petitions and other efforts have been made to ban the product and its promotion from social media. Followers of Epperly have been dubbed members of a "poop cult", and by 2017, had formed a now-defunct Facebook group made up of over 58,000 members. In 2018, the Federal Trade Commission (FTC) warned Epperly that it is against the law to advertise a product's health benefits without proper scientific support.
Overview
Jilly Juice consists solely of water, salt, and room temperature fermented cabbage or kale. According to proponents, the recipe for Jilly Juice includes two cups of water, a tablespoon of pink or sea salt, and two cups of cabbage or kale. The recipe calls for the ingredients to then be thoroughly puréed in a blender, poured into a glass jar, covered with cheesecloth, and left to ferment at room temperature for three days. Jillian Mai Thi Epperly, the creator of Jilly Juice, has claimed that salt is a "positive element" for the immune system, and that cabbage contains important probiotics and nutrients. She has recommended that individuals start consuming two cups of Jilly Juice per day, and then gradually increase consumption of it to up to 16 cups a day.
Proponents of Jilly Juice have claimed that a variety of illnesses and conditions are the result of Candida, a yeast which they claim attracts parasites in one's body. According to Epperly, an abundance of Candida in the body can cause harmful bacteria to multiply, create holes in the intestine, and allow toxins from food to enter one's bloodstream—she refers to this process as "leaky gut syndrome", or increased intestinal permeability. Epperly recommends a restricted diet supplemented by consuming large quantities of Jilly Juice, which supposedly removes Candida and parasites from one's body by inducing diarrhea (these bouts of diarrhea have been referred to by Jilly Juice advocates as "waterfalls").
Along with supposedly expunging Candida and parasites from one's body, Jilly Juice has been claimed to be able to "cure" autism, cancer, and psoriasis, as well as regenerate missing limbs, impede or reverse the effects of aging, and "cure" homosexuality.
Efficacy and toxicity
Drinking Jilly Juice is wholly ineffective in treating any ailment, and can cause extreme dehydration and potentially fatal hypernatremia (salt intoxication). Joseph A. Schwarcz, director of McGill University's Office for Science and Society, has noted that the drink's dangerously high salt concentration can lead to hypertension. Poor fermentation of the drink could also lead to ill effects. David Seres, director of medical nutrition at Columbia University Medical Center, has called the claims of Jilly Juice proponents "absolutely dangerous nonsense".
In 2018, the Federal Trade Commission (FTC) warned Epperly about claims made regarding Jilly Juice in a letter that stated: "It is against the law to make health claims, whether directly or indirectly, through advertising or other means, without adequate scientific support at the time the claims are made, or to exaggerate the benefits of products or services you are promoting".
History
Origins
Jillian Mai Thi Epperly, the creator of Jilly Juice, was born in Vietnam. She moved to the United States in May 1975 before the age of two, where she was adopted by American parents. Her father worked in biotechnology, which she claims helped her to realize that the pharmaceutical industry is working with doctors to keep consumers addicted to medication. She met her husband online and moved to Ohio to live with him. She developed premenstrual dysphoric disorder (PMDD), and after being exposed to various conspiracy theories such as the anti-vaccination movement and the chemtrail conspiracy theory, she sought out alternative medicine to treat her PMDD.
Epperly claimed that in her online research of various diseases, she discovered that Candida or other fungi were "always a factor". She therefore concluded that Candida was responsible for a large number of diseases. Epperly began trying recipes for kombucha and pickles before deciding on fermented cabbage with a significant salt content. The result was a room temperature brew of water, salt, and fermented cabbage or kale. Epperly claims this mixture can treat a number of illnesses and conditions and has marketed it as "Jilly Juice".
Spread
Epperly began making Jilly Juice with cabbage and kale in October 2016, and by January 2017, she was posting videos related to the drink on her personal Facebook page. The videos garnered a following, leading to the creation of a Facebook group known as "Exposing the Lies Candida: Weaponized Fungus Mainstreaming Mutancy". Over the next few months, the group grew to include thousands of members. In the Facebook group, members would often post images of their bowel movements, comments about supposed parasites visible in said bowel movements, and videos of themselves drinking Jilly Juice, preparing Jilly Juice as an enema, or giving Jilly Juice orally to young children and infants.
In February 2017, after receiving backlash from groups opposed to the promotion and consumption of Jilly Juice, Epperly launched a website, Jillyjuice.com, and removed the Facebook group from public view. At its peak, the Facebook group had amassed over 58,000 members. Content on Jillyjuice.com, which includes private forums, can be accessed by paying $30 annually or $5 monthly. Epperly has also provided private phone consultations for $70 an hour.
In May 2018, Epperly appeared on the American talk show Dr. Phil. The show's host, Phil McGraw, called Epperly's claims regarding Jilly Juice "outrageous."
Death of Bruce Wilmot
In the summer of 2017, Bruce Wilmot, who was diagnosed with metastatic pancreatic cancer, began taking Jilly Juice. Wilmot's daughter Taylor described him as "emaciated", and stated that he "was drinking so much of it, he was basically starving himself. It was all coming out as diarrhea."
On July 20, 2017, about a month after he began drinking Jilly Juice, Bruce Wilmot died. Epperly responded to his death in a video by saying that Wilmot did not consume enough Jilly Juice, stating that he "really should have kept going", and that his medications, his consumption of pineapple juice, or the medical industry may have contributed to his death. Epperly later wrote that she "can't be held accountable" for deaths resulting from her product, and that "correlation does not mean causation."
Backlash
After Epperly's Facebook group grew in popularity, several other Facebook groups were created which opposed her and her followers' claims regarding Jilly Juice. A movement of Jilly Juice opponents, which has been described as "anti-juice", "anti-Jillian", and "anti-Epperly", has itself accrued thousands of adherents. Petitions on Change.org calling for Epperly and Jilly Juice to be banned from social media have also been created, and anti-Epperly advocates have reported her false health claims to the FDA, the FTC, the State Medical Board of Ohio, and the Ohio Attorney General's Office.
See also
Detoxification (alternative medicine)
Hypernatremia
James Morison (physician), who promoted strong laxatives as a cure-all during the 1800s
Rope worms
Notes
References
External links
Why Dr. Phil Says ‘Jilly Juice’ Creator’s Claims Are ‘Outrageous And Offensive’, Dr. Phil, 2018
Alternative cancer treatments
Alternative detoxification
Fermented drinks
Patent medicines
Sexual orientation change efforts
Autism pseudoscience | Jilly Juice | [
"Biology"
] | 1,818 | [
"Fermented drinks",
"Biotechnology products"
] |
62,319,702 | https://en.wikipedia.org/wiki/Cryptosporella%20suffusa | Cryptosporella suffusa is a species of fungus that causes canker in alder trees.
In 2003 in Alaska, many individual thinleaf alder trees (Alnus incana subsp. tenuifolia) were observed to be dying back, with hundreds or thousands of acres of riparian woodland being affected. Individual trunks and whole clumps were involved, dying within two weeks of the onset of the disease. The cause was found to be the fungus Cryptosporella suffusa, which may also have been responsible for a similar mass mortality of alders in the area in the 1950s. The affected trees seemed to be those suffering from stress, perhaps brought on by drought or resulting from defoliating insects such as the woolly alder sawfly.
References
Gnomoniaceae
Fungus species | Cryptosporella suffusa | [
"Biology"
] | 164 | [
"Fungi",
"Fungus species"
] |
62,319,780 | https://en.wikipedia.org/wiki/Bipolar%20magnetic%20semiconductor | Bipolar magnetic semiconductors (BMSs) are a special class of magnetic semiconductors characterized by a unique electronic structure, where valence band maximum (VBM) and conduction band minimum (CBM) are fully spin polarized in the opposite spin direction. BMSs can be described by three energy gaps, the spin-flip gap Δ2 in valence band (VB), band gap Δ1 and spin-flip gap Δ3 in conduction band (CB). Up to now, bipolar magnetic semiconductors, together with half-metal and spin gapless semiconductor, have been viewed as three important classes of spintronic materials.
Properties and potential applications
The proposal of bipolar magnetic semiconductor (BMS) is aimed to realize electrical control of carriers' spin orientation, which is a key scientific problem in developing high performance spintronics devices, since electric field can be easily applied locally, in contrast to magnetic field. In BMS, the carriers' spin orientation can be controlled simply by altering the sign of the applied gate voltage. Under zero gate voltage (VG = 0), BMS is semiconducting. Under negative gate voltages (VG < 0) which shift down the material's Fermi level (EF) into spin-flip gap Δ2 in valence band, BMS conducts with carriers fully spin up polarized, while the conducting carriers change to be fully spin down polarized when positive gate voltages (VG > 0) push the Fermi level (EF) up into spin-flip gap Δ3 in conduction band. BMS is expected to be applied as bipolar field effect spin filter and field effect spin valve, or entangled electron detectors and separators.
Materials developments
A number of BMS materials have been theoretically predicted, such as MnPSe3 nanosheets, Heusler alloys FeVXSi (X = Ti, Zr), double perovskites A2CrOsO6 (A=Ca, Sr, Ba) and DPP-based metal–organic framework. However, the experimental realization of electrical control of spin orientation in these materials still keeps a challenge and needs further experimental efforts.
References
Spintronics
Semiconductor material types | Bipolar magnetic semiconductor | [
"Physics",
"Chemistry",
"Materials_science"
] | 453 | [
"Semiconductor material types",
"Spintronics",
"Semiconductor materials",
"Condensed matter physics"
] |
62,321,302 | https://en.wikipedia.org/wiki/List%20of%20proposed%20Solar%20System%20probes | This is a list of proposed space probes that are planned to focus on the exploration of the Solar System, ordered by date of spacecraft launch. Launched probes are in the List of Solar System probes and the List of active Solar System probes.
Planned or scheduled missions
Proposed missions
Suspended missions
The following missions were suspended or cancelled because of political, budgetary, or other reasons. The spacecraft were already assembled at the time of suspension/cancellation, so these missions can be resumed.
See also
Timeline of Solar System exploration
List of space telescopes#To be launched
List of proposed space observatories
List of missions to the Moon#Future missions
List of missions to Venus#Future missions
List of missions to Mars#Future missions
List of missions to the outer planets#Future missions
List of minor planets and comets visited by spacecraft#Future visits
List of objects at Lagrange points#Future and proposed missions
List of heliophysics missions#Proposed missions
References
Solar System Exploration
Discovery and exploration of the Solar System
Solar System spacecraft | List of proposed Solar System probes | [
"Astronomy"
] | 205 | [
"History of astronomy",
"Solar System",
"Discovery and exploration of the Solar System"
] |
62,321,646 | https://en.wikipedia.org/wiki/BugsXLA | BugsXLA is a Microsoft Excel add-in that provides a graphical user interface for WinBUGS, OpenBUGS and JAGS, developed by Phil Woodward. BugsXLA allows a wide range of Bayesian models to be fitted to data stored in Excel using model statements similar to those used in R, SAS or Genstat. It has been used to analyse data in a variety of application areas, for example quality engineering, pharmaceutical research, organisational sciences and ecology. The primary purpose of BugsXLA is to reduce the learning curve associated with using Bayesian software. It does this by removing the need to know how to code in the BUGS language, how to create the other files needed, as well as providing reasonable default initial values and prior distributions.
References
External links
BugsXLA page
BugsXLA YouTube
Statistical software | BugsXLA | [
"Mathematics"
] | 169 | [
"Statistical software",
"Mathematical software"
] |
62,322,378 | https://en.wikipedia.org/wiki/Lactarius%20adhaerens | Lactarius adhaerens is a member of the large milk-cap genus Lactarius in the order Russulales. It is found in Madagascar, where it grows on decayed wood. The species was first described in 1938 by French botanist Roger Heim.
See also
List of Lactarius species
References
External links
adhaerens
Fungi described in 1938
Fungi of Madagascar
Fungus species | Lactarius adhaerens | [
"Biology"
] | 81 | [
"Fungi",
"Fungus species"
] |
62,323,650 | https://en.wikipedia.org/wiki/Journal%20of%20Infrastructure%20Systems | The Journal of Infrastructure Systems is a quarterly peer-reviewed scientific journal published by the American Society of Civil Engineers covering all aspects of civil engineering.
Abstracting and indexing
The journal is abstracted and indexed in Ei Compendex, Science Citation Index Expanded, ProQuest databases, Civil Engineering Database, Inspec, Scopus, and EBSCO databases.
References
External links
Civil engineering journals
American Society of Civil Engineers academic journals
English-language journals
Academic journals established in 1995 | Journal of Infrastructure Systems | [
"Engineering"
] | 98 | [
"Civil engineering journals",
"Civil engineering"
] |
62,324,537 | https://en.wikipedia.org/wiki/William%20S.%20Burnside | William Snow Burnside (20 December 1839 – 11 March 1920) was an Irish mathematician whose entire career was spent at Trinity College Dublin (TCD). He is chiefly remembered for the book The Theory of Equations: With an Introduction to the Theory of Binary Algebraic Forms (1881) and his long tenure as Erasmus Smith's Professor of Mathematics at TCD. He is sometimes confused with his rough contemporary, the English mathematician William Burnside.
William Snow Burnside was born at Corcreevy House, near Fivemiletown, Tyrone, to William Smyth Burnside (1810–1884, Chancellor of Clogher Cathedral) and Anne Henderson (1808–1881). He studied mathematics under George Salmon at TCD (BA 1861, MA 1866, Fellowship 1871), and taught there until his retirement in 1917. He served as Erasmus Smiths's Professor of Mathematics for many decades (1879–1913), and co-authored the influential 1881 book The Theory of Equations: With an Introduction to the Theory of Binary Algebraic Forms with his TCD colleague Arthur William Panton (1843–1906). It ran to at least 7 editions, and was reissued by Dover Books in 1960. TCD awarded him a DSc in 1891. He lived one and a half miles away from campus, on Raglan Road, and was allegedly "the last man to regularly arrive in College on horseback".
References
Alumni of Trinity College Dublin
Academics of Trinity College Dublin
Algebraists
19th-century Irish mathematicians
1839 births
1920 deaths
20th-century Irish mathematicians | William S. Burnside | [
"Mathematics"
] | 310 | [
"Algebra",
"Algebraists"
] |
62,324,970 | https://en.wikipedia.org/wiki/James%20L.%20Skinner | James L. Skinner (born August 17, 1953) is an American theoretical chemist. He is the Joseph O. and Elizabeth S. Hirschfelder Professor Emeritus at the University Wisconsin-Madison. Until 2024 he was a member of the Scientific Advisory Board of the Welch Foundation. Until 2020, Skinner was the Crown Family Professor of Molecular Engineering, professor of chemistry, director of the Water Research Initiative and deputy dean for faculty affairs of the Pritzker School of Molecular Engineering at the University of Chicago. Skinner is recognized for his contributions to the fields of theoretical chemistry, nonequilibrium statistical mechanics, linear and nonlinear spectroscopy of liquids, amorphous and crystalline solids, surfaces, proteins, and supercritical fluids. Skinner is the co-author of over 230 peer-reviewed research articles.
Education
Skinner received his A. B. in chemistry and physics, both with highest honors, from the University of California, Santa Cruz in 1975. He received a Ph.D. in chemical physics from Harvard University in 1979 where he was a recipient of an NSF Graduate Fellowship and studied under the guidance of Peter G. Wolynes. The following year Skinner spent as an NSF Postdoctoral Fellow at Stanford University, where he worked with Hans Andersen and Michael Fayer.
Career
Skinner joined the department of chemistry at Columbia University as an assistant professor of chemistry in 1981. He was promoted to associate professor in 1985 and became a professor of chemistry in 1986. In 1990, Skinner was appointed as the director of the Theoretical Chemistry Institute and became the Joseph O. and Elizabeth S. Hirschfelder Professor of Chemistry at the University of Wisconsin-Madison. From 2004 to 2007, Skinner served as the chair of the department of chemistry at the University of Wisconsin-Madison. In 2015–2016, he served on the University of Wisconsin Campus Planning Committee and the Academic Planning Council. Skinner resigned his position as the director of the Theoretical Chemistry Institute and retired from the University of Wisconsin-Madison in December 2016, where he currently holds the title of Joseph O. and Elizabeth S. Hirschfelder Professor Emeritus. In January 2017, Skinner joined the Institute for Molecular Engineering (now Pritzker School of Molecular Engineering) at the University of Chicago as the Crown Family Professor of Molecular Engineering. He also served as the director of the Water Research Initiative and deputy dean for faculty affairs at the Pritzker School of Molecular Engineering. In 2020, he moved back to his position at the University of Wisconsin.
Professional service
During his career Skinner has held multiple professional appointments. From 1993 to 1996, he was, consequently, the vice-chair, chair-elect, and chair of the theoretical subdivision of the physical division of the American Chemical Society and from 2000 to 2004 he was the vice-chair-elect, vice-chair, vice-chair and then chair of the Gordon Conference on Molecular Electronic Spectroscopy. In 2007, he was a member of the Committee of Visitors of the NSF Chemistry Division. From 2007 to 2010, Skinner was a member-at-large of the chemical physics division of the American Physical Society. From 2011 to 2014, he was the vice-chair, chair-elect, and the chair of chemical physics division of the American Physical Society. Since 2008 Skinner was a vice-chair and in 2014 he was the chair of American Conference on Theoretical Chemistry. While at the University of Chicago, Skinner actively participated in the University of Chicago-Argonne National Laboratory partnership by serving on the advisory board of the Midwest Integrated Center for Computational Materials in 2016. Since 2015, he is an active member of the scientific advisory board of the Welch Foundation. Since 2017, Skinner has been actively involved in the governance of the Telluride Science and Research Center (TSRC). From 2017 to 2019, he was a member of the board of directors of TSRC, becoming president of TSRC in 2018.
Editorial service
Skinner has served on editorial boards of several scientific journals, including Single Molecules (2000–2003), Journal of Physical Chemistry (2004–2006), Chemical Physics (2005–2009), and Molecular Physics (2008–2014). Skinner had a long-standing relationship with The Journal of Chemical Physics. In 1999, he joined the editorial board, and became an associate editor in 2009. Since 2015, Skinner served as a deputy editor of The Journal of Chemical Physics, retiring from his editorial service in 2019.
Honors and awards
Throughout his career Skinner has received numerous awards including the ACS Irving Langmuir Award in Chemical Physics (2012), ACS Division of Physical Chemistry Award in Theoretical Chemistry (2011), Hilldale Award in the Physical Sciences, University of Wisconsin-Madison (2015), Wisconsin Alumni Research Foundation (WARF) named professorship, University of Wisconsin Chancellor's Distinguished Teaching Award (2003), Pharmacia Teaching Award, department of chemistry, University of Wisconsin-Madison (2000), Phi Lambda Upsilon Fresenius Award (1989), Camille and Henry Dreyfus Teacher-Scholar Award (1984–89), National Science Foundation Presidential Young Investigator (1984–1989), National Science Foundation Postdoctoral Fellowship (1980–1981), and National Science Foundation Graduate Fellowship (1975–1978). Skinner is a member of the National Academy of Sciences (2012), American Academy of Arts and Sciences (2006), American Association for the Advancement of Science (2003). He is an Alfred P. Sloan Fellow (1984–88), Guggenheim Fellow (1993–94), Humboldt Foundation Senior Scientist (1993–97), Fellow of the American Chemical Society (2012) and American Physical Society (1997).
Named and distinguished lectures
Kistiakowsky Prize Lecture, Harvard University, 2019.
Rockwell Lecture, University of Houston, 2019.
Joe L. Franklin Memorial Lecture, Rice University, 2019.
A. D. Little Lectures, Massachusetts Institute of Technology, 2019.
Borden Lecture, University of Washington, 2019.
Daniel Kivelson Lecture, University of California Los Angeles, 2017.
Frontiers in Spectroscopy Lectures, Ohio State University, 2016.
Malcolm Dole Lectures in Physical Chemistry, Northwestern University, 2015.
Sessler Lecture, Stanford University, 2015.
E. U. Condon Lecture, University of Colorado Boulder, 2013.
Priestley Lecture, Pennsylvania State University, 2013.
Vasser Woolley Distinguished Lecture, Georgia Tech, 2013.
Hirschmann Visiting Professor Lectures, University of Pennsylvania, 2013.
TSRC R. Stephen Berry Lecture, Telluride CO, 2012.
University of Missouri Chancellor's Distinguished Visitor, 2012.
W. Albert Noyes, Jr. Memorial Lecturer, University of Rochester, 2008.
Bryan Earl Kohler Lecturer, University of California, Riverside, 2005.
Reilly Lecturer, University of Notre Dame, 2003.
Norman Hascoe Distinguished Lecturer, University of Connecticut, 1998.
Gerhard Closs Lecturer, University of Chicago, 1997.
Davidson Lecturer, University of Kansas, 1995.
References
External links
Research Group website at the University of Wisconsin-Madison.
Living people
Columbia University faculty
University of Wisconsin–Madison faculty
University of Chicago faculty
University of California, Santa Cruz alumni
Harvard University alumni
1953 births
American chemists
Theoretical chemists | James L. Skinner | [
"Chemistry"
] | 1,434 | [
"Theoretical chemists",
"American theoretical chemists"
] |
62,325,228 | https://en.wikipedia.org/wiki/Milnor%E2%80%93Wood%20inequality | In mathematics, more specifically in differential geometry and geometric topology, the Milnor–Wood inequality is an obstruction to endow circle bundles over surfaces with a flat structure. It is named after John Milnor and John W. Wood.
Flat bundles
For linear bundles, flatness is defined as the vanishing of the curvature form of an associated connection. An arbitrary smooth (or topological) d-dimensional fiber bundle is flat if it can be endowed with a foliation of codimension d that is transverse to the fibers.
The inequality
The Milnor–Wood inequality is named after two separate results that were proven by John Milnor and John W. Wood. Both of them deal with orientable circle bundles over a closed oriented surface of positive genus g.
Theorem (Milnor, 1958) Let be a flat oriented linear circle bundle. Then the Euler number of the bundle satisfies .
Theorem (Wood, 1971) Let be a flat oriented topological circle bundle. Then the Euler number of the bundle satisfies .
Wood's theorem implies Milnor's older result, as the homomorphism classifying the linear flat circle bundle gives rise to a topological circle bundle via the 2-fold covering map , doubling the Euler number.
Either of these two statements can be meant by referring to the Milnor–Wood inequality.
References
Differential geometry
Geometric topology | Milnor–Wood inequality | [
"Mathematics"
] | 275 | [
"Topology",
"Geometric topology"
] |
62,325,867 | https://en.wikipedia.org/wiki/Palmitate%20mediated%20localization | Palmitate mediated localization is a biological process that trafficks a palmitoylated protein to ordered lipid domains.
Biological function
One function is thought to cluster proteins to increase the efficiency of protein-protein interactions and facilitate biological processes. In the opposite scenario palmitate mediated localization sequesters proteins away from a non-localized molecule. In theory, disruption of palmitate mediated localization then allows a transient interaction of two molecules through lipid mixing. In the case of an enzyme, palmitate can sequester an enzyme away from its substrate. Disruption of palmitate mediated localization then activates the enzyme by substrate presentation.
Mechanism of sequestration
Palmitate mediated localization is integral to spatial biology; in particular, lipid partitioning and the formation of lipid rafts. Sequestration of palmitoylated proteins is regulated by cholesterol. Depletion of cholesterol with methyl-beta cyclodextrin disrupts palmitate mediated localization.
References
Biological processes | Palmitate mediated localization | [
"Biology"
] | 204 | [
"nan"
] |
64,572,169 | https://en.wikipedia.org/wiki/CYP52%20family | Cytochrome P450, family 52, also known as CYP52, is a cytochrome P450 family in fungi participate in the assimilation of alkanes and fatty acids, which the most ancient function was the oxidation of C4-C11 alkanes. The first gene identified in this family is the alkane-inducible cytochrome P450 (P450alk) gene from the yeast Candida tropicalis, with CYP Symbol CYP52A1.
References
Fungus genes
52
Protein families | CYP52 family | [
"Biology"
] | 112 | [
"Protein families",
"Fungi",
"Fungus genes",
"Protein classification"
] |
64,572,373 | https://en.wikipedia.org/wiki/Phase-space%20wavefunctions | Phase-space representation of quantum state vectors is a formulation of quantum mechanics elaborating the phase-space formulation with a Hilbert space. It "is obtained within the framework of the relative-state formulation. For this purpose, the Hilbert space of a quantum system is enlarged by introducing an auxiliary quantum system. Relative-position state and relative-momentum state are defined in the extended Hilbert space of the composite quantum system and expressions of basic operators such as canonical position and momentum operators, acting on these states, are obtained." Thus, it is possible to assign a meaning to the wave function in phase space, , as a quasiamplitude, associated to a quasiprobability distribution.
The first wave-function approach of quantum mechanics in phase space was introduced by Torres-Vega and Frederick in 1990 (also see). It is based on a generalised Husimi distribution.
In 2004 Oliveira et al. developed a new wave-function formalism in phase space where the wave-function is associated to the Wigner quasiprobability distribution by means of the Moyal product. An advantage might be that off-diagonal Wigner functions used in superpositions are treated in an intuitive way, , also gauge theories are treated in an operator form.
Phase space operators
Instead of thinking in terms multiplication of function using the star product, we can shift to think in terms of operators acting in functions in phase space.
Where for the Torres-Vega and Frederick approach the phase space operators are
with
and
And Oliveira's approach the phase space operators are
with
In the general case
and
with , where , , and are constants.
These operators satisfy the uncertainty principle:
Symplectic Hilbert space
To associate the Hilbert space, , with the phase space , we will consider the set of complex functions of integrable square, in , such that
Then we can write , with
where is the dual vector of . This symplectic Hilbert space is denoted by .
An association with the Schrödinger wavefunction can be made by
,
letting , we have
.
Then .
Torres-Vega–Frederick representation
With the operators of position and momentum a Schrödinger picture is developed in phase space
The Torres-Vega–Frederick distribution is
Oliveira representation
Thus, it is now, with aid of the star product possible to construct a Schrödinger picture in phase space for
deriving both side by , we have
therefore, the above equation has the same role of Schrödinger equation in usual quantum mechanics.
To show that , we take the 'Schrödinger equation' in phase space and 'star-multiply' by the right for
where is the classical Hamiltonian of the system. And taking the complex conjugate
subtracting both equations we get
which is the time evolution of Wigner function, for this reason is sometimes called quasiamplitude of probability. The -genvalue is given by the time independent equation
.
Star-multiplying for on the right, we obtain
Therefore, the static Wigner distribution function is a -genfunction of the -genvalue equation, a result well known in the usual phase-space formulation of quantum mechanics.
In the case where , worked in the beginning of the section, the Oliveira approach and phase-space formulation are indistinguishable, at least for pure states.
Equivalence of representations
As it was states before, the first wave-function formulation of quantum mechanics was developed by Torres-Vega and Frederick, its phase-space operators are given by
and
This operators are obtained transforming the operators and (developed in the same article) as
and
where .
This representation is some times associated with the Husimi distribution and it was shown to coincides with the totality of coherent-state representations for the Heisenberg–Weyl group.
The Wigner quasiamplitude, , and Torres-Vega–Frederick wave-function, , are related by
where and .
See also
Wigner quasiprobability distribution
Husimi Q representation
Quasiprobability distribution
Phase-space formulation
References
Quantum mechanics | Phase-space wavefunctions | [
"Physics"
] | 821 | [
"Theoretical physics",
"Quantum mechanics"
] |
64,572,404 | https://en.wikipedia.org/wiki/Matching%20polytope | In graph theory, the matching polytope of a given graph is a geometric object representing the possible matchings in the graph. It is a convex polytope each of whose corners corresponds to a matching. It has great theoretical importance in the theory of matching.
Preliminaries
Incidence vectors and matrices
Let G = (V, E) be a graph with n = |V| nodes and m = |E| edges.
For every subset U of vertices, its incidence vector 1U is a vector of size n, in which element v is 1 if node v is in U, and 0 otherwise. Similarly, for every subset F of edges, its incidence vector 1F is a vector of size m, in which element e is 1 if edge e is in F, and 0 otherwise.
For every node v in V, the set of edges in E adjacent to v is denoted by E(v). Therefore, each vector 1E(v) is a 1-by-m vector in which element e is 1 if edge e is adjacent to v, and 0 otherwise. The incidence matrix of the graph, denoted by AG, is an n-by-m matrix in which each row v is the incidence vector 1E(V). In other words, each element v,e in the matrix is 1 if node v is adjacent to edge e, and 0 otherwise.
Below are three examples of incidence matrices: the triangle graph (a cycle of length 3), a square graph (a cycle of length 4), and the complete graph on 4 vertices.
Linear programs
For every subset F of edges, the dot product 1E(v) · 1F represents the number of edges in F that are adjacent to v. Therefore, the following statements are equivalent:
A subset F of edges represents a matching in G;
For every node v in V: 1E(v) · 1F ≤ 1.
AG · 1F ≤ 1V.
The cardinality of a set F of edges is the dot product 1E · 1F . Therefore, a maximum cardinality matching in G is given by the following integer linear program: Maximize 1E · x
Subject to: x in {0,1}m
__ AG · x ≤ 1V.
Fractional matching polytope
The fractional matching polytope of a graph G, denoted FMP(G), is the polytope defined by the relaxation of the above linear program, in which each x may be a fraction and not just an integer:Maximize 1E · x
Subject to: x ≥ 0E
__ AG · x ≤ 1V.This is a linear program. It has m "at-least-0" constraints and n "less-than-one" constraints. The set of its feasible solutions is a convex polytope. Each point in this polytope is a fractional matching. For example, in the triangle graph there are 3 edges, and the corresponding linear program has the following 6 constraints: Maximize x1+x2+x3
Subject to: x1≥0, x2≥0, x3≥0.
__ x1+x2≤1, x2+x3≤1, x3+x1≤1.This set of inequalities represents a polytope in R3 - the 3-dimensional Euclidean space.
The polytope has five corners (extreme points). These are the points that attain equality in 3 out of the 6 defining inequalities. The corners are (0,0,0), (1,0,0), (0,1,0), (0,0,1), and (1/2,1/2,1/2). The first corner (0,0,0) represents the trivial (empty) matching. The next three corners (1,0,0), (0,1,0), (0,0,1) represent the three matchings of size 1. The fifth corner (1/2,1/2,1/2) does not represent a matching - it represents a fractional matching in which each edge is "half in, half out". Note that this is the largest fractional matching in this graph - its weight is 3/2, in contrast to the three integral matchings whose size is only 1.
As another example, in the 4-cycle there are 4 edges. The corresponding LP has 4+4=8 constraints. The FMP is a convex polytope in R4. The corners of this polytope are (0,0,0,0), (1,0,0,0), (0,1,0,0), (0,0,1,0), (0,0,0,1), (1,0,1,0), (0,1,0,1). Each of the last 2 corners represents matching of size 2, which is a maximum matching. Note that in this case all corners have integer coordinates.
Integral matching polytope
The integral matching polytope (usually called just the matching polytope) of a graph G, denoted MP(G), is a polytope whose corners are the incidence vectors of the integral matchings in G.
MP(G) is always contained in FMP(G). In the above examples:
The MP of the triangle graph is strictly contained in its FMP, since the MP does not contain the non-integral corner (1/2, 1/2, 1/2).
The MP of the 4-cycle graph is identical to its FMP, since all the corners of the FMP are integral.
The matching polytopes in a bipartite graph
The above example is a special case of the following general theorem:G is a bipartite graph if-and-only-if MP(G) = FMP(G) if-and-only-if all corners of FMP(G) have only integer coordinates.This theorem can be proved in several ways.
Proof using matrices
When G is bipartite, its incidence matrix AG is totally unimodular - every square submatrix of it has determinant 0, +1 or −1. The proof is by induction on k - the size of the submatrix (which we denote by K). The base k = 1 follows from the definition of AG - every element in it is either 0 or 1. For k>1 there are several cases:
If K has a column consisting only of zeros, then det K = 0.
If K has a column with a single 1, then det K can be expanded about this column and it equals either +1 or -1 times a determinant of a (k − 1) by (k − 1) matrix, which by the induction assumption is 0 or +1 or −1.
Otherwise, each column in K has two 1s. Since the graph is bipartite, the rows can be partitioned into two subsets, such that in each column, one 1 is in the top subset and the other 1 is in the bottom subset. This means that the sum of the top subset and the sum of the bottom subset are both equal to 1E minus a vector of |E| ones. This means that the rows of K are linearly dependent, so det K = 0.
As an example, in the 4-cycle (which is bipartite), the det AG = 1. In contrast, in the 3-cycle (which is not bipartite), det AG = 2.
Each corner of FMP(G) satisfies a set of m linearly-independent inequalities with equality. Therefore, to calculate the corner coordinates we have to solve a system of equations defined by a square submatrix of AG. By Cramer's rule, the solution is a rational number in which the denominator is the determinant of this submatrix. This determinant must by +1 or −1; therefore the solution is an integer vector. Therefore all corner coordinates are integers.
By the n "less-than-one" constraints, the corner coordinates are either 0 or 1; therefore each corner is the incidence vector of an integral matching in G. Hence FMP(G) = MP(G).
The facets of the matching polytope
A facet of a polytope is the set of its points which satisfy an essential defining inequality of the polytope with equality. If the polytope is d-dimensional, then its facets are (d − 1)-dimensional. For any graph G, the facets of MP(G) are given by the following inequalities:
x ≥ 0E
1E(v) · x ≤ 1 (where v is a non-isolated vertex such that, if v has only one neighbor u, then {u,v} is a connected component of G, and if v has exactly two neighbors, then they are not adjacent).
1E(S) · x ≤ (|S| − 1)/2 (where S spans a 2-connected factor-critical subgraph.)
Perfect matching polytope
The perfect matching polytope of a graph G, denoted PMP(G), is a polytope whose corners are the incidence vectors of the integral perfect matchings in G. Obviously, PMP(G) is contained in MP(G); In fact, PMP(G) is the face of MP(G) determined by the equality:1E · x = n/2.Edmonds proved that, for every graph G, PMP(G) can be described by the following constraints:1E(v) · x = 1 for all v in V (-- exactly one edge adjacent to v is in the matching)
1E(W) · x ≥ 1 for every subset W of V with |W| odd (-- at least one edge should connect W to V\W). These constraints are called odd cut constraints.
x ≥ 0EUsing this characterization and Farkas lemma, it is possible to obtain a good characterization of graphs having a perfect matching. By solving algorithmic problems on convex sets, one can find a minimum-weight perfect matching.
See also
Stable matching polytope
References
External links
The matching polytope, by Michael Goemans
The matching polytope, by Jan Vondrak
The matching polytope, by Vincent Jost
Matching (graph theory)
Polytopes | Matching polytope | [
"Mathematics"
] | 2,186 | [
"Matching (graph theory)",
"Mathematical relations",
"Graph theory"
] |
64,573,180 | https://en.wikipedia.org/wiki/AirPods%20Max | AirPods Max are wireless Bluetooth over-ear headphones designed by Apple, and released on December 15, 2020. They are Apple's highest-end option in the AirPods lineup, sold alongside the base model AirPods and mid-range AirPods Pro.
The main changes of the AirPods Max over the mid-range AirPods Pro are the over-ear design with larger speakers, inclusion of Apple's Digital Crown (found on the Apple Watch), more color options, and longer battery life.
Overview
Apple announced AirPods Max on December 8, 2020 via a press release, and released them on December 15, 2020. AirPods Max features an over-ear headphone design.
AirPods Max have an H1 chip in each ear cup, which is also found in the second-generation AirPods and first-generation AirPods Pro. AirPods Max, like the AirPods Pro, come with Apple's Active Noise Cancellation technology for blocking outside noise, and Transparency mode for listening to sounds around users. The "Digital Crown", similar to that of the Apple Watch, allows users to play or pause audio, control volume, skip tracks, control phone calls, and activate Siri. Proximity sensors automatically detect when they are on a user's head and play or pause audio accordingly. Spatial audio uses built-in gyroscopes and accelerometers to track movement of the user's head and provide what Apple describes as a "theater-like" experience.
Apple claims 20 hours of battery life, with five minutes of charging delivering 1.5 hours of listening time. AirPods Max are charged via the Lightning port. The Lightning port can also be used for line-in audio, with Apple selling cables with USB-A, USB-C and 3.5mm headphone ends.
AirPods Max are bundled with a Smart Case for storing. The Smart Case includes magnets that switch AirPods Max to low-power mode.
AirPods Max are available in five colors: Space Gray, Silver, Sky Blue, Green, and Pink. Users can select from these five colors separately for the ear cushions and external chassis for a total of 25 color combinations (or 125 if using two different ear cushion colors).
Updated AirPods Max were released on September 20, 2024. They feature USB-C charging and new colors: Midnight, Starlight, Blue, Purple, and Orange.
Compatibility
AirPods Max are compatible with any device that supports Bluetooth, including Android and Windows devices, although certain features such as Siri require an Apple device running iOS 14.3, iPadOS 14.3, watchOS 7.2, tvOS 14 or macOS Big Sur.
Criticism
The AirPods Max Smart Case's design has been mocked by technology reviewers, along with users on Twitter for its resemblance to that of a bra or purse. Reporter Daniel Piper of Creative Bloq states: "If we're not entirely convinced by the design of the AirPods Max themselves, we're utterly baffled by that of their charging 'Smart Case'. The shape resembles, well, lots of things, from handbags to body parts."
Numerous people have reported that condensation can build up near the drivers of the closed-back headphones after prolonged use under the removable ear cups. It has been suspected that the major cause is its full-metal body that naturally has temperature-dependent thermal conductivity.
See also
References
Headphones
IPhone accessories
Apple Inc. peripherals
Products introduced in 2020 | AirPods Max | [
"Technology"
] | 715 | [
"IPhone accessories",
"Components"
] |
64,573,476 | https://en.wikipedia.org/wiki/List%20of%20Netflix%20India%20originals | Netflix India is an Indian subsidiary of the American global internet streaming on-demand media provider Netflix that distributes a number of content called "originals" (films, series, miniseries, etc.) along with acquired content, it is creating quite a niche especially among Indian youngsters, with award winning film director Vipin Agnihotri also working on three projects, latest one being Do Patti & CTRL. It was launched in January 2016.
This article gives a list of originals produced or distributed by Netflix India. Netflix's first originals for India was Love per Square Foot and Sacred Games (both released on 2018).
TV shows
Scripted
Unscripted
Docuseries
Reality
Talk Show
Kids and family
Co-productions
Continuations
Films
Feature films
Documentaries
Interactive special
Stand-up comedy specials
Specials
Series/collections
Exclusive international distribution
TV shows
Films
See also
List of Amazon India originals
List of Hotstar original films
List of Disney+ Hotstar original programming
List of SonyLIV original programming
List of ZEE5 original programming
JioCinema
Notes
References
External links
Netflix Originals current list on Netflix (based on geolocation)
Netflix original programming
Netflix
Netflix
India originals
India originals
Internet-related lists
India originals | List of Netflix India originals | [
"Technology"
] | 238 | [
"Computing-related lists",
"Internet-related lists"
] |
64,574,512 | https://en.wikipedia.org/wiki/Rita%20Casadio | Rita Casadio is an Adjunct Professor of Biochemistry/Biophysics in the Department of Pharmacy and Biotechnology at the University of Bologna.
Career
She earned her degree in physics at the University of Bologna, Italy. In 1987, she began her academic career as an assistant professor of biophysics at the University of Bologna, later becoming a full professor of biochemistry/biophysics in 2001. Her research primarily focuses on membrane and protein biophysics, as well as computer modeling of biological processes, including protein folding, stability and interactions.
She has authored more than 500 scientific papers and held key roles in various editorial and organizational positions within the field of bioinformatics.
Her work in machine learning has been used for protein structure prediction and methods from her group have been highly ranked in international competitions, such as the Critical Assessment of protein Structure Prediction (CASP) and the Critical Assessment of Function Annotation (CAFA).
Awards and honours
She was elected a Fellow of the International Society for Computational Biology (ISCB) in 2020 for outstanding contributions to the fields of computational biology and bioinformatics.
See also
ELIXIR
References
External links
Living people
Italian bioinformaticians
Academic staff of the University of Bologna
Year of birth missing (living people)
21st-century women scientists
Women biochemists
Computational biologists
Women computational biologists | Rita Casadio | [
"Chemistry"
] | 266 | [
"Biochemists",
"Women biochemists"
] |
64,574,584 | https://en.wikipedia.org/wiki/Quenching%20%28astronomy%29 | In astronomy, quenching is the process in which star formation shuts down in a galaxy. A galaxy that has been quenched (with little active star formation) is called a quiescent galaxy. Several possible astrophysical mechanisms have been proposed that could lead to quenching, which either result in a lack of cold molecular gas, or a decrease in how efficiently stars can form from molecular gas.
Quenching mechanisms
Active supermassive black holes
Evidence suggests that active supermassive black holes may drive quenching. The strong jets of some active supermassive black holes may heat up cold gas, thus suppressing star formation.
Environmental quenching
Several proposed galaxy quenching mechanisms rely on the environment a galaxy is situated in. One example of this is when a galaxy passes through a dense intracluster or intergalactic medium. The motion of the galaxy through this medium creates a ram pressure force which can strip gas away from the galaxy. Through this mechanism, known as ram pressure stripping, galaxies can be depleted of gas.
Galaxy Mergers
Inflows of gas from galaxy mergers can activate supermassive black holes within galaxies, thereby resulting in quenching via feedback from active galactic nuclei jets. Merger events can also trigger rapid bursts of star formation. This rapid star formation can lead to high rates of events like supernovae, which disrupt cold gas. This quenched state is sometimes called a post-starburst galaxy.
Morphological quenching
In morphological quenching, a galaxy’s evolution from a disk to a spheroid can reduce the efficiency of star formation over time, leading to lowered rates of star formation.
Reionization
In the Epoch of Reionization, the first generation of stars heated gas throughout the universe. This process is thought to have quenched some smaller dwarf galaxies with small cold gas reservoirs.
Quenching and galaxy evolution
The process of quenching is connected to the observed dichotomy between massive galaxies of red elliptical galaxies, which have little active star formation, and blue spiral galaxies, with active star formation. One common evolutionary path on the galaxy color–magnitude diagram may start with a blue spiral galaxy with much star formation. The black hole at its center may start growing rapidly, and somehow start quenching the galaxy, which relatively quickly transitions through the "green valley", ending up more red.
References
Star formation
Galaxies
Supermassive black holes | Quenching (astronomy) | [
"Physics",
"Astronomy"
] | 490 | [
"Black holes",
"Galaxies",
"Unsolved problems in physics",
"Supermassive black holes",
"Astronomical objects"
] |
64,575,689 | https://en.wikipedia.org/wiki/SIGRed | SIGRed (CVE-2020-1350) is a security vulnerability discovered in Microsoft's Domain Name System (DNS) implementation of Windows Server versions from 2003 to 2019.
To exploit the vulnerability, an unauthenticated attacker sends malicious requests to a Windows DNS server. If exploited, the vulnerability could allow an attacker to run arbitrary code on a Domain Controller in the context of the Local System Account.
In Microsoft's advisory of the issue, the vulnerability was classified 'wormable' and was given a CVSS base score of 10.0.
It has been the subject of a Department of Homeland Security emergency directive, instructing all government agencies to deploy patches or mitigations for it in 24 hours.
The vulnerability was discovered by Check Point Software Technologies and publicly disclosed on July 14, 2020.
References
Computer security exploits | SIGRed | [
"Technology"
] | 171 | [
"Computer security exploits"
] |
64,576,705 | https://en.wikipedia.org/wiki/CYP55%20family | Cytochrome P450, family 55, also known as CYP55, is a cytochrome P450 family in fungi supposed to derived from horizontal gene transfer of Actinomycetes CYP105 family member in the ancestor of all Dikarya (Ascomycota and Basidiomycota). The first gene identified in this family is the CYP55A1 from Fusarium oxysporum encoding the NADPH dependent reductase of nitrous oxide ().
References
Fungus genes
55
Protein families | CYP55 family | [
"Biology"
] | 114 | [
"Protein families",
"Fungi",
"Fungus genes",
"Protein classification"
] |
64,577,329 | https://en.wikipedia.org/wiki/Committee%20for%20Veterinary%20Medicinal%20Products | The Committee for Veterinary Medicinal Products (CVMP) is the European Medicines Agency's committee responsible for elaborating the agency's opinions on all issues regarding veterinary medicines.
See also
Committee for Medicinal Products for Human Use
References
External links
Health and the European Union
Veterinary organizations
Pharmacy
Animal health
Animal husbandry
Medicated feed | Committee for Veterinary Medicinal Products | [
"Chemistry",
"Biology"
] | 66 | [
"Animal health",
"Pharmacology",
"Animals",
"Pharmacy"
] |
64,577,573 | https://en.wikipedia.org/wiki/MACHO%20catalyst | In homogeneous catalysis, MACHO catalysts are metal complexes containing MACHO ligands, which are of the type HN(CH2CH2PR2)2, where R is typically phenyl or isopropyl. Complexes with ruthenium(II) and iridium(III) have received much attention for their ability to hydrogenate polar bonds such as those in esters and even carbon dioxide. The catalysts appear to operate via intermediates where the amine proton and the hydride ligand both interact with the substrate. The Ru-MACHO catalyst have been commercialized for the synthesis of 1,2-propanediol from bio-derived methyl lactate.
See also
1,5-Diaza-3,7-diphosphacyclooctanes, phosphine amine ligands used in hydrogen evolution
Noyori asymmetric hydrogenation, another family of amine-phosphine catalysts
Shvo catalyst, a related bifunctional catalyst for hydrogen transfer
References
Homogeneous catalysis
Chelating agents
Diphosphines
Hydrido complexes
Chloro complexes | MACHO catalyst | [
"Chemistry"
] | 232 | [
"Catalysis",
"Chelating agents",
"Homogeneous catalysis",
"Process chemicals"
] |
64,577,716 | https://en.wikipedia.org/wiki/Adultery%20laws | Adultery laws are the laws in various countries that deal with extramarital sex. Historically, many cultures considered adultery a very serious crime, some subject to severe punishment, especially in the case of extramarital sex involving a married woman and a man other than her husband, with penalties including capital punishment, mutilation, or torture. Such punishments have gradually fallen into disfavor, especially in Western countries from the 19th century. In countries where adultery is still a criminal offense, punishments range from fines to caning and even capital punishment. Since the 20th century, criminal laws against adultery have become controversial, with most Western countries repealing them.
Most countries that criminalize adultery are those where the dominant religion is Islam, and several sub-Saharan African Christian-majority countries. Notable exceptions to this rule are the Philippines and 17 U.S. states (as well as Puerto Rico) although adultery charges are rare in the United States.
However, even in jurisdictions that have decriminalised adultery, adultery may still have legal consequences, particularly in jurisdictions with fault-based divorce laws, where adultery can constitute a ground for divorce and may be a factor in property settlement, the custody of children, the denial of alimony, etc. Adultery is not a ground for divorce in jurisdictions which have adopted a no-fault divorce model, but may still be a factor in child custody and property disputes.
The criminal status of adultery has attracted criticism, especially where there are violent penalties. The head of the United Nations expert body charged with identifying ways to eliminate laws that discriminate against women or are discriminatory to them in terms of implementation or impact, Kamala Chandrakirana, has stated that: "Adultery must not be classified as a criminal offence at all". A joint statement by the United Nations Working Group on discrimination against women in law and in practice states that: "Adultery as a criminal offence violates women’s human rights".
In Muslim countries that follow Sharia law for criminal justice, the punishment for adultery may be stoning. There are fifteen countries in which stoning is authorized as lawful punishment, though in recent times it has been legally carried out only in Iran and Somalia.
Countries which follow very strict versions of Sharia law in their criminal systems include Saudi Arabia, Iran, Brunei, Afghanistan, Sudan, Pakistan, 12 of Nigeria's 36 states (in Northern Nigeria) and Qatar; although these laws are not necessarily enforced. Al-Shabaab, a jihadist fundamentalist group based in East Africa (mainly Somalia) and Yemen also implements an extreme form of Sharia.
Punishment
In jurisdictions where adultery is illegal, punishments vary from fines (for example in the US state of Rhode Island) to caning in parts of Asia. In fifteen countries the punishment includes stoning, although in recent times it has been legally enforced only in Iran and Somalia. Most stoning cases are the result of mob violence, and while technically illegal, no action is usually taken against perpetrators. Sometimes such stonings are ordered by informal village leaders who have de facto power in the community. Adultery may have consequences under civil law even in countries where it is not outlawed by the criminal law. For instance it may constitute fault in countries where the divorce law is fault based or it may be a ground for tort.
In some jurisdictions, the "intruder" (the third party) is punished, rather than the adulterous spouse. For instance act 266 of the Penal Code of South Sudan reads: "Whoever, has consensual sexual intercourse with a man or woman who is and whom he or she has reason to believe to be the spouse of another person, commits the offence of adultery [...]". Similarly, under the adultery law in India (Section 497 of the Indian Penal Code, until overturned by the Supreme Court in 2018) it was a criminal offense for a man to have consensual sexual intercourse with a married woman, without the consent of her husband (no party was criminally punished in case of adultery between a married man and an unmarried woman).
Asia
Southwest Asia
In Southwest Asia, adultery has attracted severe sanctions, including the death penalty. In some places, such as Saudi Arabia, the method of punishment for adultery is stoning to death. Proving adultery under Muslim law can be a very difficult task as it requires the accuser to produce four eyewitnesses to the act of sexual intercourse, each of whom should have a good reputation for truthfulness and honesty. The criminal standards do not apply in the application of social and family consequences of adultery, where the standards of proof are not as exacting. Sandra Mackey, author of The Saudis: Inside the Desert Kingdom, stated in 1987 that in Saudi Arabia, "unlike the tribal rights of a father to put to death a daughter who has violated her chastity, death sentences under Koranic law [for adultery] are extremely rare."
In regions of Iraq and Syria under ISIL, there have been reports of floggings as well as execution of people who engaged in adultery. The method of execution was typically by stoning. ISIL would not merely oppose adultery but also oppose behavior that from their point of view could lead to adultery, such as women not being covered, people of the opposite sex socializing with one another, or even female mannequins in store windows.
China
In China, punishments for adultery were differentiated based on gender of the spouse until 1935. Adultery is no longer a crime in the People's Republic of China, but is a ground for divorce. It is illegal to commit adultery with the spouse of a servicemember in the People's Liberation Army.
Taiwan
In Taiwan, adultery was a criminal offense before 2020. The law was challenged in 2002 when it was upheld by the Constitutional Court. Arguments were heard again by the court in March 2020, and the court ruled the law unconstitutional on 29 May 2020. Twelve of fifteen justices issued a concurring opinion, two others concurred in part, and one dissented. The Legislative Yuan amended the on 31 May 2021, removing the article criminalizing adultery entirely.
During Qing rule in Taiwan (1683 to 1895), the husband or his relatives could bring charges. The standard sentence was ninety lashes for each of the accused. The woman could be sold or divorced. The matter could be settled out of court, with bodily harm to the accused or assorted punishments affecting his social standing. Under Japanese rule, only the husband could bring charges. The accused could be sentenced to two years imprisonment. Wife selling became illegal, although private settlements still occurred.
India
On 27 September 2018, the Supreme Court of India ruled Section 497 of the Indian Penal Code, the law which criminalized adultery, as unconstitutional. Before 2018, adultery was defined as sex between a man and a woman without the consent of the woman's husband. The man was prosecutable and could be sentenced for up to five years (even if he himself was unmarried) whereas the married woman couldn't be jailed. Men have called the law gender discrimination in that women cannot be prosecuted for adultery and the National Commission of Women has criticized the British era law of being anti-feminist as it treats women as the property of their husbands and has consequently recommended deletion of the law or reducing it to a civil offense. Extramarital sex without the consent of one's partner can be a valid grounds for monetary penalty on government employees, as ruled by the Central Administrative Tribunal.
Japan
Adultery was a crime in Japan until 1947.
South Korea
In 2015, South Korea's Constitutional Court overturned the country's law against adultery. Previously, adultery was criminalized in 1953, and violators were subject to two years in prison, with the aim of protecting women from divorce. The law was overturned because the court found that adultery is a private matter in which the state should not intervene.
Pakistan
In Pakistan, adultery is a crime under the Hudood Ordinance, promulgated in 1979. The Ordinance sets a maximum penalty of death. The Ordinance has been particularly controversial because it requires a woman making an accusation of rape to provide extremely strong evidence to avoid being charged with adultery herself. A conviction for rape is only possible with evidence from no fewer than four witnesses. In recent years high-profile rape cases in Pakistan have given the Ordinance more exposure than similar laws in other countries. Similar laws exist in some other Muslim countries, such as Saudi Arabia and Brunei.
Philippines
Adultery is a crime in the Philippines. In the Philippines, the law differentiates based on the gender of the spouse. A wife can be charged with adultery, while a husband can only be charged with the related crime of concubinage, which is more loosely defined (it requires either keeping the mistress in the family home, or cohabiting with her, or having sexual relations under scandalous circumstances). There are currently proposals to decriminalize adultery in the Philippines.
Europe
Adultery is no longer a crime in any European country.
Adultery in English law was not a criminal offence in secular law from the later twelfth century until the seventeenth century. It was punishable under ecclesiastical law from the twelfth century until jurisdiction over adultery by ecclesiastical courts in England and Wales was abolished in England and Wales (and some British territories of the British Empire) by the Matrimonial Causes Act 1857. However, in English and Welsh common law of tort it was possible from the early seventeenth century for a spouse to prosecute an adulterer for damages on the grounds of loss of consortium until the Law Reform (Miscellaneous Provisions) Act 1970. Adultery was also illegal under secular statute law for the decade in which the Commonwealth (Adultery) Act (1650) was in force.
Among the last European countries to decriminalise adultery were Italy (1969), West Germany (1969), Malta (1973), Luxembourg (1974), France (1975), Spain (1978), Portugal (1982), Greece (1983), Belgium (1987), Switzerland (1989), and Austria (1997).
In Romania adultery was a crime until 2006, though the crime of adultery had a narrow definition, excluding situations where the other spouse encouraged the act or when the act happened at a time the couple was living separate and apart; and in practice prosecutions were extremely rare.
In Turkey, adultery laws were held to be invalid in 1996/1998 because the law was deemed discriminatory as it differentiated between women and men. In 2004, there were proposals to introduce a gender-neutral adultery law. The plans were dropped, and it has been suggested that the objections from the European Union played a role.
Before the 20th century, adultery was often punished harshly. In Scandinavia, in the 17th century, adultery and bigamy were subject to the death penalty, although few people were actually executed. Examples of women who have been executed for adultery in Medieval and Early Modern Europe include Maria of Brabant, Duchess of Bavaria (in 1256), Agnese Visconti (in 1391), Beatrice Lascaris di Tenda (in 1418), Anne Boleyn (in 1536), and Catherine Howard (in 1542). The enforcement of adultery laws varied by jurisdiction. In England, the last execution for adultery is believed to have taken place in 1654, when a woman named Susan Bounty was hanged.
The European Court of Human Rights (ECHR) has had the opportunity to rule in recent years on several cases involving the legitimacy of firing a person from their job due to adultery. These cases dealt with people working for religious organizations and raised the question of the balancing of the right of a person to respect for their private life (recognized in the EU) and the right of religious communities to be protected against undue interference by the State (recognized also in the EU). These situations must be analyzed with regard to their specific circumstances, in each case. The ECtHR had ruled both in favor of the religious organization (in the case of Obst) and in favor of the fired person (in the case of Schüth).
Latin America
Until the 1990s, most Latin American countries had laws against adultery. Adultery has been decriminalized in most of these countries, including Paraguay (1990), Chile (1994), Argentina (1995), Nicaragua (1996), Dominican Republic (1997), Brazil (2005), and Haiti (2005). In some countries, adultery laws have been struck down by courts on the ground that they discriminated against women, such as Guatemala (1996), where the Guatemalan Constitutional Court struck down the adultery law based both on the Constitution's gender equality clause and on human rights treaties including CEDAW; and Venezuela in 2016. The adultery law of the Federal Criminal Code of Mexico was repealed in 2011.
Australia
Adultery is not a crime in Australia. Under federal law enacted in 1994, sexual conduct between consenting adults (18 years of age or older) is their private matter throughout Australia, irrespective of marital status. Australian states and territories had previously repealed their respective adultery criminal laws. Australia changed to no-fault divorce in 1975, abolishing adultery as a ground for divorce.
Canada
Adultery is not a crime in Canada. It has never been defined as a criminal offence within the Criminal Code, which was enacted in 1892, nor is it considered an offence at common law.
United States
The United States is one of few industrialized countries to have laws criminalizing adultery. In the United States, laws vary from state to state. Until the mid-20th century, most U.S. states (especially Southern and Northeastern states) had laws against fornication, adultery or cohabitation. These laws have gradually been abolished or struck down by courts as unconstitutional.
State criminal laws against adultery are rarely enforced. Federal appeals courts have ruled inconsistently as to whether these laws are unconstitutional (especially after the 2003 Supreme Court decision Lawrence v. Texas) and as of 2019 the Supreme Court has not ruled directly on the issue.
As of 22 November 2024, adultery remains a crime in 16 states and the Commonwealth of Puerto Rico but prosecutions are rare. Pennsylvania abolished its fornication and adultery laws in 1973. States which have decriminalised adultery in recent years include West Virginia (2010), Colorado (2013), New Hampshire (2014), Massachusetts (2018), Utah (2019), Idaho (2022), Minnesota (2023), and New York (2024). The District of Columbia repealed its adultery law in 2003. When passing the District of Columbia Organic Act of 1801, the 6th United States Congress extended all of the criminal laws of Maryland and Virginia to the respective territory within the District that each state had ceded to the federal government under Article I, Section VIII, and adultery had been an indictable offense in Maryland since the passage of a provincial law in 1715.
The last conviction for adultery in Massachusetts was in 1983 and held that the statute was constitutional and that "no fundamental personal privacy right implicit in the concept of ordered liberty guaranteed by the United States Constitution bars the criminal prosecution of such persons [adulterers]."
Today, adultery laws are mostly found in the conservative southern states.
In general, 3 US states criminalize it as a felony (Oklahoma, Michigan, and Wisconsin) and 13 states along with Puerto Rico criminalize it as a misdemeanor. Punishments range from as little as a $10 fine in Maryland (despite being technically a criminal offense, not a civil one) to a fine of up to $10,000 and jail time of up to 3.5 years in Wisconsin and a fine of up to $5,000 and jail time of up to 5 years in Michigan.
List of the statutes:
Alabama (Alabama Revised Statutes, § 13a-13-2)
Arizona (Arizona Revised Statutes, § 13–1408)
Florida (Florida Statutes, § 798.01)
Georgia (Official Code of Georgia Annotated, § 16–6–19)
Illinois (Illinois Compiled Statutes, § 720-5-11/35)
Kansas (Kansas Statutes Annotated, § 21–5511)
Maryland (Annotated Code of Maryland, § 10–5–501)
Michigan (Michigan Compiled Laws, §§ 750.29-32)
Mississippi (Unannotated Mississippi Code, § 97–29–1)
North Carolina (North Carolina General Statutes, § 14–26–184)
North Dakota (North Dakota Century Code, § 12.1-20-09)
Oklahoma (Oklahoma Statutes Annotated, §§ 21–871–872)
Rhode Island (Rhode Island General Laws, § 11–6–2)
South Carolina (South Carolina Code of Laws, §§ 16-15-60-16-15-80)
Virginia (Virginia Code Annotated, § 18–2–365)
Wisconsin (Wisconsin Statutes, § 944.16)
Puerto Rico (Puerto Rico Laws, § 33–4758)
2 of these statutes (of Mississippi and North Carolina) refer to fornication as well and thus also by definition ban any extramarital sex altogether.
1 of these statutes (of Michigan) considers cohabitation between ex-spouses after their divorce as falling under the crime of adultery.
Below is the list of the specific anti-fornication statutes (in states where there's an offense of fornication and where it's a separate offence):
Georgia (Official Code of Georgia Annotated, § 16–6–8)
Illinois (Illinois Compiled Statutes, § 720-5/11-40)
North Dakota (North Dakota Century Code, § 12.1-20-08) (note: even though the crime is called "fornication", it only refers to having sex with minors or having sex in public. It doesn't target private consensual sex between adults, so in practice this law is irrelevant; it's only listed here for the sake of completeness because the crime is called "fornication" under the North Dakotan law)
Below is the list of the specific anti-cohabitation statutes (in states where there's an offense of cohabitation and where it's a separate offence):
Massachusetts (Massachusetts General Laws, § 208–40) (note: criminalizes cohabitation between 2 ex-spouses after divorce as adultery. But since the Massachusettsan criminal anti-adultery statute was repealed in 2018 and there's no punishment for it anymore, in practice this law is an irrelevant legislative remnant with no function)
Oklahoma (Oklahoma Statutes Annotated, § 43–123) (criminalizes cohabitation between 2 ex-spouses after divorce as adultery)
Mississippi (Unannotated Mississippi Code, § 93–5–29) (criminalizes cohabitation between 2 ex-spouses after divorce as adultery)
In the U.S. military, adultery is a potential court-martial offense, falling under the General article (Art. 134). The Manual for Courts-Martial defines (para. 99) "Extramarital sexual conduct" as being:
"Elements.(1) That the accused wrongfully engaged in extramarital conduct as described in subparagraph c.(2) with a certain person; (2) That, at the time, the accused knew that the accused or the other person was married to someone else; and (3) That, under the circumstances, the conduct of the accused was either: (i) to the prejudice of good order and discipline in the armed forces; (ii) was of a nature to bring discredit upon the armed forces; or (iii) to the prejudice of good order and discipline in the armed forces and of a nature to bring discredit upon the armed forces". As such, extramarital sex is not automatically an offense, it must be conducted under such circumstances that it is prejudicial to the armed forces. The law on adultery was revised in 2019 in order to include same-sex encounters in the offense.
The enforceability of adultery laws in the United States is unclear following Supreme Court decisions since 1965 relating to privacy and sexual intimacy of consenting adults. However, occasional prosecutions do occur.
Six U.S. states (Hawaii, North Carolina, Mississippi, New Mexico, South Dakota, and Utah) allow the possibility of the tort action of alienation of affections (brought by a deserted spouse against a third party alleged to be responsible for the failure of the marriage). In a highly publicized case in 2010, a woman in North Carolina won a $9 million suit against her husband's mistress.
Laws against adultery in colonial America were very harsh. Despite this, there is only one known execution for adultery in American history: it occurred in the Colony of Massachusetts in 1643, when the married 18 year old Mary Latham and her extramarital lover James Britton were executed.
Criticism of adultery laws
Political arguments
Laws against adultery have been named as invasive and incompatible with principles of limited government (see Dennis J. Baker, The Right Not to be Criminalized: Demarcating Criminal Law's Authority (Ashgate) chapter 2). Much of the criticism comes from libertarianism, the consensus among whose adherents is that government must not intrude into daily personal lives and that such disputes are to be settled privately rather than prosecuted and penalized by public entities. It is also argued that adultery laws are rooted in religious doctrines; which should not be the case for laws in a secular state.
Opponents of adultery laws regard them as painfully archaic, believing they represent sanctions reminiscent of nineteenth-century novels. They further object to the legislation of morality, especially a morality so steeped in religious doctrine. Support for the preservation of the adultery laws comes from religious groups and from political parties who feel quite independent of morality, that the government has reason to concern itself with the consensual sexual activity of its citizens … The crucial question is: when, if ever, is the government justified to interfere in consensual bedroom affairs?
Discrimination against women
Opponents of adultery laws argue that these laws maintain social norms which justify violence, discrimination and oppression of women; in the form of state sanctioned forms of violence such as stoning, flogging or hanging for adultery; or in the form of individual acts of violence committed against women by husbands or relatives, such as honor killings, crimes of passion, and beatings. UN Women has called for the decriminalization of adultery. A Joint Statement by the United Nations Working Group on discrimination against women in law and in practice in 2012, stated:
The United Nations Working Group on discrimination against women in law and in practice is deeply concerned at the criminalization and penalization of adultery whose enforcement leads to discrimination and violence against women.
Concerns exist that the existence of "adultery" as a criminal offense (and even in family law) can affect the criminal justice process in cases of domestic assaults and killings, in particular by mitigating murder to manslaughter, or otherwise proving for partial or complete defenses in case of violence. These concerns have been officially raised by the Council of Europe and the UN in recent years. The Council of Europe Recommendation Rec(2002)5 of the Committee of Ministers to member states on the protection of women against violence states that member states should: (...) "57. preclude adultery as an excuse for violence within the family". UN Women has also stated in regard to the defense of provocation and other similar defenses that "laws should clearly state that these defenses do not include or apply to crimes of 'honour', adultery, or domestic assault or murder."
Use of limited resources
An argument against the criminal status of adultery is that the resources of the law enforcement are limited, and that they should be used carefully; by investing them in the investigation and prosecution of adultery (which is very difficult) the curbing of serious violent crimes may suffer.
Consent as the basis of sexual offenses legislation
Human rights organizations have stated that legislation on sexual crimes must be based on consent, and must recognize consent as central, and not trivialize its importance; doing otherwise can lead to legal, social or ethical abuses. Amnesty International, when condemning stoning legislation that targets adultery, among other acts, has referred to "acts which should never be criminalized in the first place, including consensual sexual relations between adults". Salil Shetty, Amnesty International's Secretary General, said: "It is unbelievable that in the twenty-first century some countries are condoning child marriage and marital rape while others are outlawing abortion, sex outside marriage and same-sex sexual activityeven punishable by death." The My Body My Rights campaign has condemned state control over individual sexual and reproductive decisions; stating "All over the world, people are coerced, criminalized and discriminated against, simply for making choices about their bodies and their lives".
References
Family law
Human sexuality
Extramarital relationships | Adultery laws | [
"Biology"
] | 5,086 | [
"Human sexuality",
"Behavior",
"Sexuality",
"Human behavior"
] |
64,581,314 | https://en.wikipedia.org/wiki/Terbium%28IV%29%20fluoride | Terbium(IV) fluoride is an inorganic compound with a chemical formula TbF4. It is a white solid that is a strong oxidizer. It is also a strong fluorinating agent, emitting relatively pure atomic fluorine when heated, rather than the mixture of fluoride vapors emitted from cobalt(III) fluoride or cerium(IV) fluoride.
Preparation
Terbium(IV) fluoride can be produced by the reaction between very pure terbium(III) fluoride and xenon difluoride, chlorine trifluoride or fluorine gas:
2 TbF3 + F2 → 2 TbF4
Properties
Terbium(IV) fluoride hydrolyzes quickly in hot water, producing terbium(III) fluoride and terbium oxyfluoride (TbOF). Heating terbium(IV) fluoride will cause it to decompose into terbium(III) fluoride and predominantly monatomic fluorine gas.
TbF4 → TbF3 + F•↑
The reaction will produce the mixed valence compound Tb(TbF5)3, which has the same crystal form as Ln(HfF5)3.
Terbium(IV) fluoride can oxidize cobalt trifluoride into cobalt tetrafluoride:
TbF4 + CoF3 → TbF3 + CoF4↑
It can fluoronate [60]fullerene at 320–460 °C.
When terbium(IV) fluoride reacts with potassium chloride and fluorine, it can produce the mixed valence compound KTb3F12. A mixture of rubidium fluoride, aluminium fluoride and terbium(IV) fluoride produces Rb2AlTb3F16.
References
attribution: This article was translated from the Chinese article :zh:四氟化铽
Terbium compounds
Fluorides
Lanthanide halides | Terbium(IV) fluoride | [
"Chemistry"
] | 429 | [
"Fluorides",
"Salts"
] |
64,581,680 | https://en.wikipedia.org/wiki/Whitewater%20Interactive%20System%20Development%20with%20Object%20Models | Wisdom (Whitewater Interactive System Development with Object Models) is a software development process and method to design software-intensive interactive systems. It is based on object modelling, and focuses human-computer interaction (HCI) in order to model the software architecture of the system i.e. it is architecture-centric. The focus on HCI while being architecture-centric places Wisdom as a pioneer method within human-centered software engineering. Wisdom was conceived by Nuno Nunes and first published in the years 1999-2000 in order to close the gaps of existing software engineering methods regarding the user interface design.
Notably, the Wisdom method identifies for each use case the tasks of the user, the interaction spaces of the user interface, and the system responsibilities that support that user activity, which are complemented with the data entities used in each case, completing a usable software architecture, an MVC model. The Wisdom model clarifies the relation between the human and the computer-based system, allows rationalization over the software artifacts that must be implemented, therefore facilitating effort affection for a software development team.
From Wisdom, other relevant contributions were derived targeting the enhancement of software development based on the Wisdom model, such as: CanonSketch, Hydra Framework Cruz's
Another relevant contribution is related to effort estimation of software development, the iUCP method, which is based in traditional UCP method leveling the estimation based on the predicted user interface design. A comparison study was carried out using both methods, revealing that there is positive effect in the usage of iUCP when compared to UCP when considering the user interface design, a recurrent situation in nowadays software systems development.
References
Object models
Computer architecture
Software architecture
Software frameworks
Software development process
fa:توسعه سیستم تعاملی Whitewater | Whitewater Interactive System Development with Object Models | [
"Technology",
"Engineering"
] | 370 | [
"Computers",
"Computer engineering",
"Computer architecture"
] |
64,582,118 | https://en.wikipedia.org/wiki/CYP53%20family | Cytochrome P450, family 53, also known as CYP53, is a cytochrome P450 monooxygenase family in fungi related to hydrocarbon assimilation. They are distributed in both Ascomycota and Basidiomycota, could be used as anti-fungal drug target. The first gene identified in this family is the CYP53A1 from Aspergillus niger encoding the Benzoate 4-monooxygenase (bphA).
References
Fungus genes
53
Protein families | CYP53 family | [
"Biology"
] | 108 | [
"Protein families",
"Fungi",
"Fungus genes",
"Protein classification"
] |
64,582,503 | https://en.wikipedia.org/wiki/Hong%20Kong%20Academy%20of%20Engineering%20Sciences | The Hong Kong Academy of Engineering (HKAE), formerly Hong Kong Academy of Engineering Sciences, is an engineering science institution based in Hong Kong. It aims on encouraging and maintaining distinction in the field of engineering with useful resolution, and to promote the development of the science, art and practice of engineering for the social well-being.
History
The Academy was established on 13 September 1994, by Sir S.Y. Chung, Prof. Yau-Kai Cheung, Sir Charles K. Kao and other engineering scholars in Hong Kong.
References
External links
HKAES Website
Professional associations based in Hong Kong
National academies of engineering
Learned societies of Hong Kong
1994 establishments in Hong Kong | Hong Kong Academy of Engineering Sciences | [
"Engineering"
] | 135 | [
"National academies of engineering"
] |
64,583,610 | https://en.wikipedia.org/wiki/Reversible%20solid%20oxide%20cell | A reversible solid oxide cell (rSOC) is a solid-state electrochemical device that is operated alternatively as a solid oxide fuel cell (SOFC) and a solid oxide electrolysis cell (SOEC). Similarly to SOFCs, rSOCs are made of a dense electrolyte sandwiched between two porous electrodes. Their operating temperature ranges from 600°C to 900°C, hence they benefit from enhanced kinetics of the reactions and increased efficiency with respect to low-temperature electrochemical technologies.
When utilized as a fuel cell, the reversible solid oxide cell is capable of oxidizing one or more gaseous fuels to produce electricity and heat. When used as an electrolysis cell, the same device can consume electricity and heat to convert back the products of the oxidation reaction into valuable fuels. These gaseous fuels can be pressurized and stored for a later use. For this reason, rSOCs are recently receiving increased attention due to their potential as an energy storage solution on the seasonal scale.
Technology description
Cell structure and working principle
Reversible solid oxide cells (rSOCs), as solid oxide fuel cells, are made of four main components: the electrolyte, the fuel and oxygen electrodes, and the interconnects.
The electrodes are porous layers that favor the reactants diffusion inside their structure and catalyze electrochemical reactions. In the single technologies like SOFCs and SOECs, the electrodes serve a single purpose, hence they are called with their specific names. The anode is where the oxidation reaction occurs, while the cathode is where the reduction reaction takes place. In reversible solid oxide cells, on the other hand, both modalities can occur alternatively in the same device. For this reason, the generic names of fuel electrode and oxygen electrode are preferred instead. On the fuel electrode the reactions involving the fuel oxidation (SOFC modality) or the reduction of the products to produce the fuel (SOEC modality) takes place. On the oxygen electrode, oxygen reduction (SOFC modality) or oxygen ions oxidation to form oxygen gas (SOEC modality) takes place.
State-of-the-art materials for rSOCs are those used for SOFCs. The most common fuel electrodes are made by a mixture of nickel, that serves as electronic conductor, and yttria-stabilized zirconia (YSZ), a ceramic material characterized by high conductivity to oxygen ions at elevated temperature. The most popular oxygen electrode materials are lanthanum strontium cobalt ferrite (LSCF) and lanthanum strontium chromite (LSC), perovskite materials able to catalyze oxygen reduction and oxide ion oxidation reactions.
The electrolyte is a solid-state layer placed between the two electrodes. It is an electric insulator, it is impermeable to gas flow but permeable to oxygen ions flow. Hence, the main properties of this component are the high ion conductivity and the low electrical conductivity. When the rSOC is operated in SOFC mode, oxygen ions flow from the oxygen electrode to the fuel electrode, where the fuel oxidation occurs. In SOEC mode, the reactants are reduced in the anode with the production of oxygen ions, which flow towards the oxygen electrode. The most widespread material for electrolytes is YSZ.
The interconnects are usually made of metallic materials. They provide or collect the electrons involved in the electrochemical reactions. In addition, they are shaped internally with gas channels to distribute the reactants over the cell surface.
Polarization curve
The most common tool to characterize the performances of a reversible solid oxide cell is the polarization curve. In this chart, the current density is related to operating voltage of the cell. The usual convention is the one of positive current density for the fuel cell operation, and negative current density for the electrolysis operation. When the rSOC electrical circuit is not closed and no current is extracted or supplied to the cell, the operating voltage is the so-called open circuit voltage (OCV). If the composition of the gas in the fuel electrode and the oxygen electrode are the same for both modalities, the polarization curve for the SOEC mode and the SOFC have the same OCV. When some current density is extracted or supplied to the cell, the operating voltage starts to diverge from the OCV. This phenomenon is due to the polarization losses, which depend on three main phenomena:
the activation losses, predominant at very low current densities;
the ohmic losses, increasing linearly with the current density;
the concentration losses, occurring at very high current density, when the reactants inside the electrode get depleted.
The sum of the polarization losses takes the name of overpotential.
Other than the open circuit voltage, another fundamental theoretical voltage can be defined. The thermoneutral voltage depends on the enthalpy of the overall reaction taking place in the rSOC and the number of charges that are transferred within the electrochemical reactions. Its relationship with the operating voltage gives information about the heat demand or generation inside the cell.
During the electrolysis operation:
if , the reaction is endothermic;
if , the reaction is exothermic.
The fuel cell operation, instead, is always exothermic.
Chemistry
Various chemistries can be considered when dealing with reversible solid oxide cells, which in turn can influence their operating conditions and overall efficiency.
Hydrogen
When hydrogen and steam are considered as reactants, the overall reaction takes this form:
H2 + 1/2 O2 <=> H2O
where the forward reaction occurs during SOFC mode, and the backward reaction during SOEC mode. On the fuel electrode, hydrogen oxidation (forward reaction) takes in SOFC mode and water reduction (backward reaction) takes plain SOEC mode:
H2 + O^2- <=> H2O + 2e-
On the oxygen electrode, oxygen reduction (forward reaction) occurs in SOFC mode and oxide ions oxidation (backward reaction) occurs in SOEC mode:
O2 +2e- <=> O^2-
The thermoneutral voltage for steam electrolysis is equal to 1.29 V.
Carbonaceous reactants
Differently than low-temperature electrochemical technologies, rSOCs can process also carbon containing species with reduced risk of catalyst poisoning. Methane can be internally reformed on the Ni particles to produce hydrogen, similarly to what happens in steam reforming reactors. Subsequently, the produced hydrogen can undergo the electro-oxidation. Moreover, when working in SOEC modality, water and carbon dioxide can be co-electrolyzed to generate hydrogen and carbon monoxide to form syngas mixtures with various composition.
The reactions taking place on the oxygen electrode are the same considered for the hydrogen/steam case. Even if characterized by much slower kinetics with respect to the one involving hydrogen and steam, the direct electro-oxidation of carbon monoxide (forward reaction) or the direct electro-reduction of carbon dioxide (backward reaction) can be considered as well:
CO + 1/2 O2 <=> CO2
The thermoneutral voltage of the CO2 electrolysis is equal to 1.48 V.
One useful way to depict the cycling between SOFC and SOEC mode of the rSOC operation with carbonaceous reactants is the C-H-O ternary diagram. Each point in the diagram represents a gas mixture with a different number of carbon, hydrogen or oxygen atoms. When dealing with the operation on reversible solid oxide cells, three distinct regions can be distinguished in the graph. For different operating conditions (i.e., different temperature and pressure), distinct boundary lines between these regions can be drawn. The three regions are:
the carbon deposition region: gas mixtures lying in this region are characterized by compositions that are prone to carbon deposition on the fuel electrode;
the fully oxidized region: this region is characterized by gas mixtures that are fully oxidized, hence they cannot be used as fuels in the rSOC;
the operating region: this region is characterized by gas mixtures that are suitable for the rSOC operation.
In the operating region, the fuel mixture and the exhaust mixture can be depicted. These two points are connected by a line which runs through points characterized by a constant H/C ratio. In fact, during the rSOC operation in both modalities, the gases on the fuel electrode exchange with the oxygen electrode only oxygen atoms, while hydrogen and carbon are confined inside the fuel electrode. During the SOFC operation, the composition of the gas in the fuel electrode moves towards the boundary line of the fully oxidized region, increasing its oxygen content. During SOEC operation, on the other hand, the gas mixture evolves away from the fully oxidized region towards the carbon deposition region, while reducing its oxygen content.
Ammonia
An alternative and promising chemistry for rSOCs is that one involving ammonia conversion to hydrogen and nitrogen. Ammonia has great potential as hydrogen carrier, due to its higher volumetric density with respect to hydrogen itself, and it can be directly fed to SOFCs. It has been demonstrated that ammonia-fed SOFCs operate through successive ammonia decomposition and hydrogen oxidation:
2NH3 -> N2 + 3H2
H2 + O^2- -> H2O + 2e-
Ammonia decomposition has been demonstrated to be slightly more efficient than simple hydrogen oxidation, confirming the great potential of ammonia as a fuel other than an energy carrier.
Unfortunately, ammonia cannot be directly synthesized on the fuel electrode of a rSOC, because the equilibrium reaction
N2 + 3H2 <=> 2NH3
is completely shifted towards the left at their higher than 600°C working temperature. For this reason, for clean ammonia production, hydrogen production via electrolysis must be coupled with nitrogen production from air with hydrogen oxidation and subsequent water separation.
rSOC systems for energy storage
Reversible solid oxide cells are receiving increased attention as energy storage solutions for the weekly or the monthly scale. Other technologies for large scale electrical storage such as pumped-storage hydroelectricity and compressed air energy storage are characterized by geographical limitations. On the other hand, Li-ion batteries suffer from limited discharge capabilities. In this regard, hydrogen storage is a promising alternative, since the produced fuel can be compressed and stored for months. Among all hydrogen technologies, rSOCs are definitely the best candidates for producing and converting back hydrogen into electricity. Due to their high operating temperature, they are characterized by higher efficiency, compared to technologies like PEM fuel cells or PEM electrolyzers. Moreover, the possibility to operate both the fuel oxidation and the electrolysis on the same device is beneficial on the capacity factor of the system, helping at reducing its specific investment cost.
Roundtrip efficiency
When dealing with rSOCs, the most important parameter to consider is the roundtrip efficiency, which is a measure of the efficiency of the system considering both the charge (SOEC) and discharge (SOFC) preocesses. The roundtrip efficiency for the single cell can be defined as:
where is the charge supplied or consumed during the reactions, and is the operating voltage. If the assumption of no current or reactants leakage is made, the exchanged charges during the reactions can be assumed to be equal. Then, the roundtrip efficiency can be written as:
To maximize the roundtrip efficiency, the two operating voltages must be as close as possible. This condition can be achieved by operating the rSOC with low current densities in both modalities. In SOFC mode this is easily pursuable, while in SOEC mode a too low voltage may lead to an endothermic operation. If the operating voltage in SOEC mode is lower than the thermoneutral voltage, additional heat sources at high temperature are needed to sustain the reaction. These could come from waste industrial heat or from nuclear reactors. If not easily accessible, though, electrical heating is necessary. This can be supplied by external additions or by operating the cell with an operating voltage higher than the thermoneutral one. Both solutions, though, would inevitably lower the roundtrip efficiency of the rSOC. For this reason, in reversible operation, the thermoneutral voltage poses significant limitations in achieving high roundtrip efficiencies.
On the other hand, the thermoneutral voltage is greatly affected by the reaction chemistry. It has been demonstrated that increasing the yield of methane in the electrolysis operation can substantially decreases the thermoneutral voltage and heat demand of the reaction. For conventional electrolyzers (operating at atmospheric pressure and 750°C), the methane content in the products is very low. It can be increased effectively by lowering the operating temperature to 600°C and increasing the operating pressure up to 10 bar. For example, the thermoneutral voltage is equal to 1.27 V at 750°C and 1 bar, while it becomes equal to 1.07 V at 600°C and 10 bar. In these conditions, the rSOC can even be operated in exothermic mode at reduced voltages, permitting to produce additional heat at high temperature. This result becomes very helpful in the design of high efficiency rSOC systems for energy storage purposes.
System configurations
Single reversible solid oxide cells can be arranged in series to form stacks. Single stacks can be then arranged in modules to reach power capabilities in the order of kilowatts or megawatts.
One of the most challenging aspects in designing large rSOC systems for energy storage purposes is the thermal integration. When the rSOC is operated in electrolysis mode, thermal power is needed for the operation of the system. Thermal power must be provided at two different temperature levels. Heat is needed for water operation, and additional heat at high temperature may be needed if the SOEC modality is endothermic. The latter requirement can be avoided if the rSOC is operated with an exothermic reaction in SOEC modality, with a negative effect on the roundtrip efficiency. On the other hand, when the rSOC is operated in fuel cell mode, the reaction is characterized by a high exothermicity. A number of works in the scientific literature have proposed the exploitation of a Thermal energy storage (TES) to ease the thermal integration of the system.
Excess heat from the SOFC operation can be recovered and stored in a TES, and later used for the SOEC operation. Thermal energy storage typologies and heat transfer fluids that have been considered for this purpose are those used for Concentrated solar power (CSP) technologies. Diathermic oil can be used to store heat at relatively low temperature (for instance, 180°C) and exploited for water evaporation. Alternatively, phase-change materials characterized by high fusion points can be used to store heat at high temperature and enable the endothermic operation in the electrolysis mode. In this case, usually, rSOCs operate at different temperature levels in the two modalities (for example, 850°C in SOFC mode and 800°C in SOEC mode).
If carbonaceous chemistries are employed, the beneficial effect of methane synthesis inside the cell can be exploited to reduce the heat request of the electrolysis mode. In this regard, systems operating at high pressure and lower temperature (20 bar and 650°C) have been proposed to reduce or even eliminate the thermal power requirement of the rSOC system. Alternatively, the production of methane can be favored in external reactors. The methanation reaction is exothermic and favored at low temperature.
CO + 3H2 <=> CH4 + H2O .
The syngas that produced by the co-electrolysis can undergo a further reaction in one or multiple methanation reactors to produce methane and generate low-temperature heat for water evaporation. In addition, the formation of methane in such systems may be beneficial to the size of the tanks used for storing the fuels. In fact, methane is characterized by a higher volumetric energy density than hydrogen in the gaseous form.
When computing the roundtrip efficiencies of rSOC systems, the definition must take into account the net electric consumption (or additional electric production) of other components inside the system. The set of these component is regarded as balance of plant (BOP), and may comprehend pumps, compressors, expanders or fans, needed for fluid circulation and processing inside the system. Therefore, the system roundtrip efficiency can be defined as:
where:
is the electric power produced in SOFC mode;
is the electric power consumed in SOEC mode;
is the net electric power consumption (negative) or production (positive) by the BOP in FC mode;
is the net electric power consumption (negative) or production (positive) by the BOP in EC mode.
The roundtrip efficiencies achievable with rSOC systems operating with steam and hydrogen can reach values in the order of 60%. On the other hand, systems exploiting the beneficial effects of methane formation, either inside the rSOC or in external reactors, can reach rountrip efficiencies in the order of 70% and beyond.
See also
High temperature electrolysis
Solid oxide fuel cell
Solid oxide electrolyzer cell
Power-to-gas
Energy storage
Grid energy storage
Thermal energy storage
Hydrogen technologies
References
Electrochemistry
Energy conversion
Electrolysis
Hydrogen economy
Hydrogen technologies
Energy storage | Reversible solid oxide cell | [
"Chemistry"
] | 3,583 | [
"Electrochemistry",
"Electrolysis"
] |
64,583,833 | https://en.wikipedia.org/wiki/Montgomery%20Reservoir | Montgomery Reservoir lies high in Colorado's Mosquito Range near Hoosier Pass a few miles north of Alma, Colorado. The reservoir sits at an altitude of . It is owned by Colorado Springs Utilities and delivers water to Colorado Springs, Colorado for municipal use. Built in 1957, the reservoir stores water from the Middle Fork South Platte River and from a tunnel that brings water from the Blue River on the west side of the continental divide.
Transbasin diversion
Most of the water entering the reservoir comes through the Hoosier Tunnel which collects water from the Blue River watershed on the west side of the continental divide and conveys it to the east side, an instance of a transbasin diversion. Because the reservoir lies near the top of the headwaters of the Middle Fork South Platte River, the watershed above the dam is rather small — only in size, so its catchment basin is limited. Thus the chief source of the lake's water is the Hoosier Tunnel.
The reservoir is drained by the Blue River Pipeline, a long pipeline that flows by gravity to the Colorado Springs Utilities-owned North and South Catamount reservoirs on the slopes of Pikes Peak. From there, the water is treated and delivered to municipal water customers in Colorado Springs.
Dam
Montgomery Dam is a rockfill structure. It is approximately long and high. When it was built, the dam was sealed with an asphalt concrete facing.
References
Montgomery Reservoir
Bodies of water of Park County, Colorado
United States local public utility dams
Interbasin transfer | Montgomery Reservoir | [
"Environmental_science"
] | 306 | [
"Hydrology",
"Interbasin transfer"
] |
51,927,914 | https://en.wikipedia.org/wiki/Pulsar%20%28film%29 | Pulsar is a 2010 Belgian techno-thriller film directed by Alex Stockman and starring Matthias Schoenaerts.
Plot
Samuel works in Brussels as a pharmaceutical delivery man. His girlfriend, Mireille, moves to New York to intern at a prestigious architecture firm. After her departure, Sam's computer is hacked. The mysterious hacker seems intent on messing up Samuel's life and his relationship with Mireille. Sam starts to suspect his neighbors and gets obsessed with WiFi-rays.
Cast
Matthias Schoenaerts as Samuel Verbist
Tine Van den Wyngaert as Mireille Leduc
Andrea Bardos as Schoonmaakster
Leah Chanmugam as Buurmeisje
Liesje De Backer as Liesbet
Jessica De Baere as Ellen
Josse De Pauw as Vader
References
External links
Official website
2010 films
Belgian drama films
Belgian mystery films
Belgian romance films
Techno-thriller films
Films about computing
Films about the Internet
2010s Dutch-language films
2010s English-language films
2010s French-language films
Films set in Brussels
Films set in Belgium
Films shot in Belgium
Belgian thriller films
2010 thriller films
2010 drama films
2010 multilingual films
Belgian multilingual films
2010s Belgian films
English-language thriller films | Pulsar (film) | [
"Technology"
] | 249 | [
"Works about computing",
"Films about computing"
] |
51,931,358 | https://en.wikipedia.org/wiki/Lm%CE%B1TX3 | LmαTX3 is an α-scorpion toxin from Lychas mucronatus. that inhibits fast inactivation of voltage gated sodium-channels (VGSCs).
Etymology
The LmαTX3 toxin derives the first part of its name from the source of the venom (Lychas mucronatus, 'Lm') , the middle part due to its nature as an α-scorpion toxin ('αTX'), and the last part as a reflection of the binding to receptor site 3 the toxin acts upon.
Sources
LmαTX3 is a toxin expressed and secreted by the venom gland of Lychas mucronatus, a scorpion from the family Buthidae found in China, Laos, Thailand and other regions of Asia.
Chemistry
Scorpion toxins targeting VGSGs (also called NaTX) are usually polypeptides composed of 61–76 amino acids cross-linked by four disulfide bridges. LmαTX3 consists of the same disulfide bridge pattern and conserved residues as sodium channel-specific modulators, thus suggesting its modulating effect on sodium channels. Analysis of the amino acid sequence in cDNA previously acquired of the Lychas mucronatus showed that LmαTX3 contained 21 residues in their signal peptides, and 62 residues in their mature peptides (the peptide remaining after the cleaving of the signal peptide).
Modelling of the 3D structure of LmαTX3 showed a typical cysteine-stabilized α-helix/β-sheet motif (CSαβ motif), with the α-helix stabilized by two disulfide bridges to one strand of the β sheet. Similar to other α-scorpion toxins, LmαTX3 presented with potential functional residues in the conversed NC-domains (Lys1, Lys8, Lys 51, Asn53, Ile54 and Lys57) and the Core-domains (Arg14, Lys23, Arg39 and Lys 42). Therefore, there are strong suggestions that LmαTX3 falls under the NaTX type of channels.
The molecular weight of LmαTX3 is 9.2 kDa.
Target
Electrophysiological experiments have evaluated the effect of recombinant LmαTX3 on the following four types of sodium channels:
rNav1.2: expressed at high levels in the central nervous system
mNav1.4: mostly found in adult skeletal muscles
hNav1.5: mostly found in embryonic and denervated skeletal muscle and heart muscle
hNav1.7: primarily in the peripheral nervous system
LmαTX3 inhibits fast inactivation of these types of sodium channels. It modulates the inactivation of mNav1.4 and hNav1.5 channels more potently than of hNav1.7 channels and especially rNav1.2 channels, similar to LmαTX5.
Mode of Action
The α-toxins can inhibit the fast inactivation of VGSGs. Based on its homology to other members of the α-scorpion toxin family, LmαTX3 most likely blocks receptor site 3, which is located on the extracellular loop of sodium channels which connects the S3 and S4 segments on domain IV. Site 3 toxins prevent a component of outward gating charge movement associated with channel inactivation, it is likely that they are able to slow inactivation by preventing the outward movement of the DIV S4 segment, hence making fast inactivation difficult and prolonging the action potential. In this sense, scorpion α-toxins can be considered gating-modifier toxins.
Toxicity
Currently, there is no LmαTX3-specific knowledge of the toxic effect. Generally, scorpion α-toxins prolong the action potentials of excitable cells. These toxins can kill organisms by inducing paralysis and arrhythmia.
References
Toxins
Ion channel toxins
Scorpion toxins | LmαTX3 | [
"Environmental_science"
] | 850 | [
"Toxins",
"Toxicology"
] |
51,931,956 | https://en.wikipedia.org/wiki/SHTX | SHTX is a toxin derived from the sea anemone Stichodactyla haddoni; there are four different subtypes, SHTX I, II, III and IV. SHTX I, II and III can paralyze crabs by acting on potassium channels, while SHTX IV works on sodium channels, and is lethal to crabs.
Sources
SHTX I, II, III and IV are toxins derived from the sea anemone Stichodactyla haddoni.
Chemistry
SHTX I and II consist of 28 amino acids. SHTX I and II have been classified as members of the type IV potassium channel toxin family. The protein sequences of SHTX I and II differ only at amino acid position 6, where the SHTX I protein contains a hydroxyproline and SHTX II contains a proline. SHTX I contains two disulfide bridges between Cys-7 and -19 and between Cys-10 and -25., whereas most peptide toxins derived from sea anemones have three disulfide bridges. Because of the extensive homology between SHTX I and II, it is plausible that SHTX II will share the location of the disulfide bridges. SHTX I and II also share homology with Am I, a toxin isolated from the sea anemone Antheopsis maculata. These proteins have the same positions of cysteines in their amino acid sequences, which points towards a comparable structure. Am I is toxic to crabs and is lethal in high doses (LD50 830 μg/kg), but the target of this toxin is still unknown.
The protein SHTX III is a Kunitz-type protease inhibitor, with a length of 62 amino acids. It shows homology to other members of the Kunitz-type protease inhibitor family and the highest similarity is shown with AEPI-I, a toxin derived from the sea anemone Actinia equina.
SHTX IV is composed of 48 amino acids and is a member of the type 2 sea anemone sodium channel toxin family. The protein shares homology with the other members of this family, especially with the toxin Rp II from the sea anemone Radianthus paumotensis. The amino acid glycine at the C-terminus of the SHTX IV protein is deleted after completing translation. As a result, the mature protein has an amidated lysine at its C-terminus instead of a glycine.
Target
SHTX II acts on voltage-gated potassium channels and was reported to be approximately 50 times less potent than 125I-a-dendrotoxin to synaptosomal membranes, with an IC50 of 270 nM. The affinity and target of SHTX I has not been assessed yet, however, due to the similarities of SHTX I with SHTX II in both sequence and crab paralyzing activity, it is considered to show the same affinity to potassium channels as SHTX II.
SHTX III is known to be a Kunitz-type protease inhibitor and a potassium (Kv1.2) channel blocker. It was reported to be approximately 110 times less potent than 125I-a-dendrotoxin to synaptosomal membranes, with an IC50 of 650 nM.
SHTX IV is a type 2 sea anemone sodium channel toxin and shows 91% sequence overlap with Rp II from the sea anemone R. paumotensis. The affinity of SHTX IV to sodium channels has not been studied yet. However, the affinity of the toxin would most likely depend on the species, the issue and state of innervation it is exposed to.
Mode of action
The modes of action of SHTX I and II are currently unknown.
SHTX III has a Kunitz-domain and therefore has a protease inhibitor. In sea anemones, it has been suggested that these protease inhibitors are to protect the toxins injected to the prey and contribute to the paralysis. It also works on potassium (Kv1.2) channels as a blocker, the precise mechanism is still unknown.
SHTX IV is a type 2 sea anemone sodium channel toxin, of which the mode of action has not been studied yet. However, due to the high similarity in its sequence with Rp II it might be possible that it shares the same effect, which is prolonging the inactivation of the sodium channel.
Toxicity
SHTX I, II, III and IV are tested on crabs to reveal their paralytic activity (ED50) and lethal activity (LD50). SHTX I, II and III are not lethal to crabs, but they induce paralysis. The values of ED50 are 430 μg/kg for SHTX I and II and 183 μg/kg for SHTX III. However, SHTX IV can be lethal to crabs, with an estimated LD50 of 93 μg/kg.
Contact with the sea anemone S. haddoni can induce an anaphylactic shock.
Treatment
No specific treatment is available for intoxication with SHTX I, II, III or IV. In addition, it is not known what the specific symptoms of an intoxication with one of these toxins are in humans, since the effects of these toxins have only been tested on crabs.
References
Neurotoxins
Ion channel toxins
Sea anemone toxins | SHTX | [
"Chemistry"
] | 1,145 | [
"Neurochemistry",
"Neurotoxins"
] |
51,932,910 | https://en.wikipedia.org/wiki/Pinnatoxin | Pinnatoxins are paralytic chemical compounds that inhibit neuronal and muscle-type nicotinic acetylcholine receptors. Although first discovered in shellfish, they are produced by the peridinoid dinoflagellate Vulcanodinium rugosum. Eight subtypes, designated pinnatoxin A-H, have been described.
Discovery and distribution
Pinnatoxins are neurotoxins named after the genus Pinna, a group of bivalve molluscs, in reference to their original isolation from members of the group, Pinna attenuata and later Pinna muricata. The causative organism producing the toxin was later identified as the dinoflagellate Vulcanodinium rugosum. The presence of the toxin has been identified in various locations, including the Pacific Ocean, the Persian Gulf, the Mediterranean sea, waters near Canada, Scandinavia, and South China, and in water samples in Ireland.
Chemistry
Pinnatoxins are part of the cyclic imine group of marine toxins. This group currently consists of pinnatoxins, pteriatoxins, spirolides, gymnodimines, spiro-prorocentimine and portimine. Eight different types of pinnatoxins have been described, named pinnatoxin A to H.
All the pinnatoxins contain several key structural elements. The structure of pinnatoxin is composed of a cyclic imine (A ring) spirolinked to a cyclohexene ring (G ring), a dispiro 6,5,6 tricyclic ketal at C12-C23 (rings B, C, D), a bridged bicyclic ketal at C25-C30 (rings E, F) and a 27-membered macrocyclic ring spanning C5-C31.
Table: molecular formula and molecular weight of pinnatoxins
Target
Pinnatoxin A, G, E and F display a high-affinity antagonism for the neuronal α7 and muscle α12βϒδ nicotine acetylcholine receptors (nAChRs). The affinity of pinnatoxins for nAChR subtypes is the result of a selectivity mechanism: the bulky bridged EF-ketal ring, specific for pinnatoxins, is able to interact with the sequence-variable loop F of the nAChRs.
The inhibitory potency of pinnatoxin A depends on the nAChR subtype. It has the following ranking in selectivity: α7> α12βϒδ>α4β2. Pinnatoxin A has a 300-fold greater potency toward the α7 than to the α4β2 nAChR. Furthermore, the blocking of α7 appears to be irreversible.
Pinnatoxin G shows no selectivity between the two neuronal subtypes α7 en α4β2 nAChRs. In contrast, pinnatoxin G interacts with 25-fold higher affinity than pinnatoxin A on the muscle-type nAChR. So the selectivity rank ordering of pinnatoxin G is α12βϒδ> α7 > α3β2 α4β2. Pinnatoxin E and F have the same order of selectivity for these receptors, although they differ in their potency. The rank order of potency at all receptors is F>G>E.
Mode of action
Pinnatoxins are potent inhibitors of neuronal and muscle type nicotine acetylcholine receptors (nAChRs). They block the nAChR through adherence to the receptor binding site. Different subregions of the pinnatoxin molecule have multiple anchoring points in the receptor-binding site, through which they dictate the tight binding between the opposing loops C and F at the nAChR subunit interface.
When pinnatoxin G and F are bound to the nAChR, they can both reduce or even abolish the amplitude of miniature endplate potentials and nerve-evoked endplate potentials. They do not have an effect on the firing frequency or resting membrane potential. This is characteristic of a postsynaptic mechanism of action.
Toxicity
As of today, no pinnatoxin or cyclic imine has been linked to human poisoning. The toxic effects of pinnatoxin E-H have, however, been examined on female Swiss albino mice.
The symptoms exhibited by mice exposed to a lethal dose of pinnatoxin by intraperitoneal injection are very similar between pinnatoxin E, F, G and H. The symptoms start off with a period of hyperactivity until 10–20 minutes after injection, when an abrupt decrease in activity occurs. In the case of pinnatoxin H injection, mice become immobile instead of hyperactive. During this decrease in activity/occurrence of immobility, abdominal breathing and extension of the hind legs are observed. In some cases, mice suffer from slight exophthalmia. After this period, during which the respiration rate remains normal, the respiration rate declines rapidly within a 2 to 3-minute time interval. Death is preceded by a brief period of running movements, the occurrence of cyanosis and severe exophthalmos. The time between dosing and death varies between 14 and 50 minutes.
Apart from the greater time to onset of inactivity and abdominal breathing at lethal doses (25–40 minutes), and the time to death (approximately 1.3 hours), the symptoms after pinnatoxin E, F or G admission by gavage do not differ much from admission by intraperitoneal injection. In contrast, the time to death after admission of pinnatoxin H by intraperitoneal injection or gavage did not differ.
The behavioural abnormalities observed in mice after a sublethal dose start off with a hyperactive or immobile period shortly after toxin admission, and end with a full recovery. Furthermore, none of the toxins described above lead to aberrant behaviour or abnormal appearance during a subsequent 14-day observation period, nor do they result in any atypical observations at necropsy. However, the symptoms after the hyperactive/immobile period until full recovery, differ between the pinnatoxins:
After pinnatoxin E dosing, mice become very lethargic, achieving full recovery within an hour.
A sublethal pinnatoxin F dosing results in immobility, without full recovery until 2–3 hours after toxin admission.
A sublethal pinnatoxin H dosing results in immobility as well, with full recovery after an unspecified time span.
9–13 minutes after pinnatoxin G admission, mice become very lethargic and show an abdominal breathing pattern, while the respiration rate remains normal. Full recovery occurs within 2 hours.
References
Ion channel toxins
Neurotoxins
Invertebrate toxins
Cyclohexenes
Azepines
Spiro compounds
Tetrahydropyrans
Tetrahydrofurans | Pinnatoxin | [
"Chemistry"
] | 1,474 | [
"Organic compounds",
"Neurochemistry",
"Neurotoxins",
"Spiro compounds"
] |
51,933,137 | https://en.wikipedia.org/wiki/Microbial%20cell%20factory | Microbial cell factory is an approach to bioengineering which considers microbial cells as a production facility in which the optimization process largely depends on metabolic engineering. MCFs is a derivation of cell factories, which are engineered microbes and plant cells. In 1980s and 1990s, MCFs were originally conceived to improve productivity of cellular systems and metabolite yields through strain engineering. A MCF develops native and nonnative metabolites through targeted strain design. In addition, MCFs can shorten the synthesis cycle while reducing the difficulty of product separation.
History
Prior to MCFs, scientists employed traditional engineering techniques to produce various commodities. These methodologies include modifying metabolic pathways, eliminating enzymes, or the balancing of ATP to drive metabolic flux. However, when these approaches were applied for industrial productions, they could not withstand the industrial environments that consisted of toxins and fluctuating temperatures. Ultimately, the techniques were never able to scale up and output bio-products that were obtained in the laboratory.
Thus, MCFs were developed by using a heterogenous biosynthesis pathway in a microbial host. As a host, MCFs take in various substrates and convert them into valuable compounds. These products can range from fuels, chemical, food ingredients, to pharmaceuticals.
Structure
Cell Wall
In microbial cells, the cell walls are either Gram-positive or Gram-negative. These outcomes are based on the Gram Stain test. Gram-positive cell walls have thick peptidoglycan layer and no outer lipid membrane while Gram-negative bacteria have a thin peptidoglycan layer and an outer lipid membrane. Although a thick Gram-positive cell wall is advantageous, it is easier to attack as the peptidoglycan layer absorbs antibiotics and cleaning products. A Gram-negative cell wall is more resistant to such attacks and more difficult to destroy.
Membrane
The membrane of microbial cells are bilayers, composed of phospholipids. The phospholipids may range in chain length to branching. Ultimately, the phospholipid will determine the membrane properties, such as fluidity and charge, that will regulate the interactions with nearby proteins. In addition, the membrane oversees the development of the cell's morphology and cell sizes. Escherichia coli is often utilized a base line to differentiate and define the membrane of MCFs.
Nucleoid
The nucleoid forms an irregular shaped region within a prokaryote cell, containing all or majority of the genetic material to reproduce. The nucleoid controls the activity of the MCF and reproduction of itself and products.
Current Developments
Current methods of programming MCFs utilize strain engineering, which rely on random mutagenesis. In addition, the conventional techniques are labor-intensive, timely, and difficult to analyze. This has led many scientific trials to utilize genomic editing tools to improve MCFs, such as ZFNs, TALENs, and CRISPR. These approaches allow genetic manipulation and analysis, specifically creating double stranded breaks within a genome sequence.
ZFNs
Zinc-finger nucleases (ZFNs) were the first genomic editing tool to be able to target any genomic site. By inducing a double-stranded break, ZFNs can facilitate targeted editing. However, when employed to reinforce MCFs, ZFNs have an unusual low success rate. In various trials, the ZFNs were unable to obtain a three-finger array or the triplet was unable to be assembled into a new sequence. Thus, incorporation of ZFNs into MCFs has remained strenuous and costly.
TALENs
Transcription activator-like effector nucleases (TALENs) work in a similar manner to ZFNs, but TALENs are based on fusion proteins. TALENs have been applied to numerous MCFs, such as yeast and zebrafish. Many developments has explored fairyTALE, a liquid phase synthesis TALEN platform, to create nucleases, activators, and repressors for MCFs. Although TALENs have fewer obstacles than ZFNs, they are still troublesome as assembling large quantities of repeats into an array remains a significant problem.
CRISPR
Clustered regularly interspaced palindromic repeats (CRISPR) and its associated proteins (Cas) has become one of the most popular genome editing tools due to its efficiency and low cost. The CRISPR/CAS9 has been utilized to enhance MCFs to produce yeast, bacteria, and E.coli. When optimizing yeast, CRISPR/CAS9 promoting S.pyogenes has been found to be the most influential strategy. For E.coli, studies have determined a strategy preventing genome instability to be the most robust metabolic engineering approach regardless of the specific methodology.
Large-Scale Application
The most significant advantage of MCFs is the ability to be utilized in industrial environments with minimal limitations. Through metabolic engineering, MCFs rely on innovative strategic tools for the development and optimization of metabolic and gene regulatory networks for efficient production. Going from lab to large scale development involves consideration of three factors: product yield, productivity, and the product titre. A common dilemma however is the trade-off between product yield and productivity. If a company maximizes productivity, they will ultimately lower their product yield and vice versa.
To combat this issue, strategies have been developed to maximize all three factors. One of the most common techniques is utilizing fed-batch culture. Fed-batch culture is, in the broadest sense, defined as an operational technique in biotechnological processes where one or more nutrients (substrates) are fed (supplied) to the bioreactor during cultivation and in which the product(s) remain in the bioreactor until the end of the run. Another method is utilizing continuous cultivation strategy. The premise behind continuous cultivation is to maintain a steady-state cell metabolism over long periods of times. By having multiple approaches for MCF, companies may customize each process to their specific product(s).
Commercialization
The commercialization of MCFs has ranged from chemical to biofuels.
References
Biological engineering | Microbial cell factory | [
"Engineering",
"Biology"
] | 1,244 | [
"Biological engineering"
] |
51,933,157 | https://en.wikipedia.org/wiki/NGC%20272 | NGC 272 is an open cluster (rather an L-shaped asterism) located in the constellation Andromeda. It was discovered on August 2, 1864, by Heinrich d'Arrest.
References
External links
0272
18640802
Andromeda (constellation)
Open clusters | NGC 272 | [
"Astronomy"
] | 59 | [
"Andromeda (constellation)",
"Constellations"
] |
51,933,204 | https://en.wikipedia.org/wiki/NGC%20273 | NGC 273 is an edge-on lenticular galaxy in the constellation Cetus. It was discovered on September 10, 1785, by William Herschel.
References
External links
17850910
Cetus
0273
002959
Lenticular galaxies
Discoveries by William Herschel | NGC 273 | [
"Astronomy"
] | 55 | [
"Cetus",
"Constellations"
] |
51,933,299 | https://en.wikipedia.org/wiki/Limbatustoxin | Limbatustoxin (LbTX; α-KTx 1.4), is an ion channel toxin from the venom of the Centruroides limbatus scorpion. This toxin is a selective blocker of BK channels, calcium-activated potassium channels.
Etymology and source
Limbatustoxin is purified from the venom of the Centruroides limbatus, a bark scorpion that lives in Central America.
Chemistry
Limbatustoxin (LbTX; α-KTx 1.4) is a 37-amino acid peptide, which belongs to the α-KTx 1.x subfamily, a group of short peptides consisting of 36-37 amino acid residues and three disulfide bridges. LbTX displays 57% sequence homology with charybdotoxin and 70% sequence homology with iberiotoxin. LbTX contains a β-sheet formed by three anti-parallel β-strands on one side of the molecule and a helix on the other side. This structure is important for binding to BK channels.
Target and mode of action
Limbatustoxin is highly selective for calcium-activated potassium channels, also called maxi-K channels, slo1 or BK (big potassium) channels. These channels play an important role in the excitability of neurons and the control of muscle contractions. Residues on β-sheet face of the helix as well as residues in the turn between the helix and the second anti-parallel strand and in the second and third strands of the β-sheet are critical for the binding of the toxin to the BK channel. When binding to the channel, limbatustoxin is known to block and inhibit the function of the BK channel. It seems likely that limbatustoxin modifies the gating mechanism of the channel, because the toxin binds to the β-subunit of the channel, which has a modulating function on the gating of the channel. Based on the 70% homology with iberiotoxin, it seems likely that the limbatustoxin selectively inhibits the current through the BK channel by decreasing probability of opening and the time that the channel is open.
Toxicity
The venom causes local burning pain and systemic symptoms, such as parasthesias, flushing, hypertension and wheezing. It is not considered dangerous to humans.
References
Ion channel toxins
Scorpion toxins
Toxins | Limbatustoxin | [
"Environmental_science"
] | 486 | [
"Toxins",
"Toxicology"
] |
51,933,345 | https://en.wikipedia.org/wiki/Kalkitoxin | Kalkitoxin, a toxin derived from the cyanobacterium Lyngbya majuscula, induces NMDA receptor mediated neuronal necrosis, blocks voltage-dependent sodium channels, and induces cellular hypoxia by inhibiting the electron transport chain (ETC) complex 1.
Natural sources
Kalkitoxin is an ichthyotoxin, derived from the cyanobacterium Lyngbya majuscula which covers sections of the coral reef. It typically forms mini-blooms and produces several metabolites, such as kalkitoxin, curacin-A and antillatoxin. Kalkitoxin has been found and purified near the coasts of Curaçao and Puerto Rico.
Structure and reactivity
Kalkitoxin is a lipopeptide toxin with a molecular weight of 366.604Da. Its chemical formula is C21H38N2OS. The structure contains two double bonds, a 2,4-disubstituted thiazoline ring system, and an additional carbonyl-group. These four groups each provide a degree of unsaturation, which causes kalkitoxin to have four degrees of unsaturation. The structure contains 5 chiral centers, one of which is due to a substituent of the thiazoline ring, and the other four are due to methine groups along the aliphatic carbon chain, which are tertiary carbon atoms bearing three single carbon bonds and one hydrogen. The four methyl groups (each at a methine chiral center), the structure's overall stereochemistry, and the N-methyl group all contribute to the toxicity of kalkitoxin.
Structure determination
The structure of kalkitoxin was first determined by characterizing six partial structures which were subsequently connected to yield the total structure. This investigation was largely carried out through various NMR experiments. Structure (a) is a sec-butyl group, indicated by characteristic deshielding of its central methine group due to the adjacent carbonyl. Structure (b) contains this carbonyl group, and an adjacent tertiary methylated nitrogen atom, constituting a tertiary amide group. Since this is a tertiary amide, it exists in a cis/trans mixture, which underlies the two conformations of kalkitoxin. Structure (c) is a string of two methylene groups, then a methine group bearing a high-field methyl group. The next two groups identified (d,e) are identical and opposing strings of CH2-CH-CH3, however the left grouping's methylene protons experience greater deshielding, due to their proximity to the adjacent imine. Deshielding is an effect of a nearby electronegative atom withdrawing electron density from a given atom nucleus, eliciting an increased chemical shift as measured by NMR.
The final partial structure consists of a thiazoline ring with a terminal alkene substituent, as determined by electron ionization mass spectrometry (EI-MS) and 13C NMR. The chemical shifts of ring carbons adjacent to the sulfur and nitrogen heteroatoms were compared to 13C NMR data from model compounds. This allowed for the determination of these heteroatoms' locations in the ring, and subsequently the existence of the thiazoline ring itself. With these partial structures established, their connectivity was evaluated via HMBC spectroscopy, a 2D NMR technique which allows for the determination of heteronuclear J-coupling values for nonadjacent carbons and protons. This allows for the spatial relation of specific carbon and hydrogen atoms within a structure to be determined.
Stereochemistry
Kalkitoxin has five chiral centers, one of which is the ring carbon to which the terminal alkene is coordinated, with the remaining four occurring at tertiary carbon atoms along the aliphatic chain originating from the imine nitrogen. The total stereochemistry of natural (+)-kalkitoxin is 3R,7R,8S,10S,2′R. For this determination, 3JCH values by a variation of the HSQMBC pulse technique, a type of HMBC spectroscopy, and 3JHH values by exclusive correlation spectroscopy (E.COSY). These methods use NMR to evaluate the spin-spin coupling constants which directly relate to the dihedral angle of the atoms being analyzed, allowing for the determination of chirality. This was used to determine the stereochemistry of chiral centers at C7, C8, and C10. Because C7 and C8 are adjacent stereocenters, these techniques allowed for immediate determination of their relative stereochemistry, however C10 is separated from C8 by C9, which carries two diastereotopic protons. This allows for the determination of relative stereochemistry of C8 and C10 to the C9 protons through [[J-coupling \ 3J coupling]] values, so as to relate the relative stereochemistry of C8 to C10. These methods yielded a relative stereochemistry of 7R, 8S, 10S for the aliphatic chain stereocenters. Stereochemistry at C3 was determined by Marfey's analysis, wherein the compound was ozonized and subsequently hydrolyzed to obtain cysteic acid from the thiazoline ring and attached terminal alkene. Marfey's analysis indicated this amino acid derivative was L-cysteic acid, indicating R absolute stereochemistry at C3. The absolute stereochemistry of the total molecule was determined by synthesizing the possible configurations of the already determined relative chiralities, and comparison of these to natural Kalkitoxin via 13C NMR shift differences, revealing the natural (+)-kalkitoxin stereochemistry to be 3R,7R,8S,10S,2′R.
Structure-activity relationship
The structure-activity relationship (SAR) of a molecule is the connection between the structural moieties within the compound, and how those specific structures directly contribute to the extent and character of the molecule's biological activity. Kalkitoxin exhibits potent cytotoxicity which relies on the complete thiazoline ring for its action. Kalkitoxin analogs lacking the complete thiazoline ring exhibit on the order of 1000-fold decreased toxicity to solid tumor cell lines. This indicates the thiazoline ring structure is a crucial component of kalkitoxin's mechanism of cytotoxicity. The necessity of the stereochemistry exhibited in natural (+)-kalkitoxin decreases moving towards the chiral centers in the core of the molecule, while the more terminal chiral centers and amide methyl group are increasingly crucial for toxicity. In a study which assayed for the toxicity of kalkitoxin and various analogs against brine shrimp, the analogs which experienced the least significant loss of potency were epimers at either C8 or C10. This indicates that C8 and C10 chiralities in natural (+)-kalkitoxin are the least critical for toxic biological activity. It is apparent that C10 chirality is less critical than C8, because the epimer of (+)-kalkitoxin at C10 is more potent than the epimer at C8. Furthermore, the removal of the C10 methyl group has a smaller impact on potency than does epimerization of C7, supporting the trend of decreased SAR correlation at core chiral centers on the aliphatic chain. Epimerization at C3, the attachment point of the terminal alkene to the thiazoline ring, further decreases potency of kalkitoxin, in agreement with the thiazoline ring and overall conformation of the leftmost segment of the molecule being critical for bioactivity. Finally, replacement of the tertiary amide with a secondary amide eliminates any observable toxicity, so this structure is crucial in the mechanism of kalkitoxin toxicity.
Synthesis
Wu et al. synthesis
This effort was the first total synthesis of (+)-kalkitoxin, and served the purpose of deducing the specific stereochemistry of natural kalkitoxin. This synthesis began from an alcohol bearing the proper chirality at C8 and C10 found in (+)-kalkitoxin, and carried a dimethylphenylsiloxy (DPSO) group positioned beta to C8, and a terminal alkene positioned alpha to C10. Hydroboration of this alkene gives the resulting alcohol, which is converted to an azide, which is the position at which (R)-2-methylbutyric acid is coupled to produce the sec-butyl group and amide group. The amide is subsequently methylated, finalizing the tertiary amide which has been shown to be so crucial for kalkitoxin toxicity. O-Desilylation and oxidation of the resulting alcohol produce an acceptor for a Horner-Wadsworth-Emmons reaction, wherein a carbonyl and an alpha-methylated phosphonate react to produce an alkene. In this case, a beta-keto phosphonate bearing an (R)-phenylglycine-derived auxiliary group was ligated to the molecule. This group is lost in asymmetric conjugate addition of an (R)-amino alcohol, which, through two cyclodehydration steps using Wipf's oxazoline-thiazoline interconversion protocol, produces the thiazoline ring.
White et al. synthesis
The second total synthesis of (+)-kalkitoxin was only 16 steps and gave a 3% overall yield. A major aspect by which this differs from the first total synthesis of (+)-kalkitoxin is that rather than using a Horner-Wadsworth-Emmons reaction to ligate a phosphonate carrying the 4-phenyl-2-oxazolidinone, an organocopper conjugate addition reaction was used instead. This was done specifically by connecting the organocopper species to a 4-phenyl-2-oxazolidinone carrying an (S)-N-trans-crotonyl group through a 1,4-nucleophilic addition to the α,β-unsaturation of the crotonyl group. This method is advantageous because it allows for stereoselectivity of the resulting 1,3-dimethyl configuration during the larger sequential introduction of the methyl substituents at the C7, C8 and C10 chiral centers.
Another point of diversion between these two syntheses is the number of carbons separating the keto-auxiliary group from the chiral center at C7. This group was separated by one carbon from C7 in the first total synthesis, so the keto-auxiliary moiety could be converted to a carboxylic acid, in anticipation of addition of the amino alcohol immediately thereafter. In this synthesis, this keto-auxiliary group is directly adjacent to C7, necessitating a one carbon homologation, before construction of the thiazoline ring. This was achieved through reductive bond cleavage of the auxiliary group to a primary alcohol and oxidation to the corresponding aldehyde, Wittig reaction using an ylide carrying a methoxy group to produce an enol ether, hydrolysis to the aldehyde and finally oxidation to produce the carboxylic acid.
Balieu et al. synthesis
This synthesis differentiates itself in that it takes an "assembly line" synthesis approach, as opposed to the conventional iterative synthetic approach taken in previous syntheses which normally necessitate functional-group interconversions and repetitive purifications for aliphatic chain extensions, such as the one found in kalkitoxin. This novel approach is achieved through the use of reagent-controlled chain extension of a boronic ester, which relies on a spontaneous 1,2-migration after formation of an intermediate compound incorporating a newly added lithiated benzoate ester building block.
This allows for control of chirality at each addition by selecting the chirality of each benzoate ester added. Furthermore, this avoids repetitive interconversion and purification steps normally required for repeat chain extensions, which increases yield and efficiency and decreases labor. This synthesis capitalized on this technique by producing the core aliphatic chain as a single large fragment, and coupled this fragment to the chiral sec-butyl group bearing a carboxylic acid. The opposing amino thioether fragment was synthesized separately, and then adjoined and subsequently cyclized following the procedure devised by White et al. In total, this synthesis requires only 7 steps if the initial homologation series is counted as one step.
Published on Nature : Burns, M., Essafi, S., Bame, J. et al. Assembly-line synthesis of organic molecules with tailored shapes. Nature 513, 183–188 (2014). https://doi.org/10.1038/nature13711
Targets
Kalkitoxin may activate the NMDA receptor. It also blocks the voltage-gated sodium channel and the electron transport chain (ETC) complex 1. It remains unknown how exactly kalkitoxin binds to the voltage-gated sodium channel. Neurotoxin sit 1 and 2 have been ruled out as possible binding sites, whereas neurotoxin site 7 is suggested as binding site for kalkitoxin. This is probable, because there is inhibition of the channel by kalkitoxin when deltamethrin, which has positive allosteric effects, is present. This could be because molecular determinants for binding are similar in kalkitoxin and deltamethrin.
Mode of action
Kalkitoxin induces delayed neuronal necrosis in cerebellar granule cells of the rat. This neuronal necrosis proved to be NMDA-receptor mediated. These receptors are normally activated by glutamate and other excitotoxic compounds and can induce neuronal necrosis. It is not yet known if the toxin induces necrosis directly or via the release of excitotoxic compounds.
Secondly, kalkitoxin blocks voltage-gated sodium channels, thereby inhibiting Ca2+ release that normally occurs when the voltage-gated sodium channel is activated, in a concentration dependent matter. Calcium release has been shown to induce lactate dehydrogenase (LDH) production. The amount of LDH is a measure for neuronal cell death. In the presence of kalkitoxin there is also a concentration-dependent inhibition of neuronal cell death and LDH production (9). The mechanism behind this inhibition is still unknown.
Thirdly, kalkitoxin blocks the electron transport chain (ETC) complex 1, one of the protein complexes involved in mitochondrial respiration. By blocking the ETC complex 1, kalkitoxin potently inhibits hypoxia-inducible factor-1 (HIF-1) activation. HIF-1 is a transcription factor, which enhances the expression of genes that increase oxygen availability, as well as genes that decrease oxygen consumption. Inhibition of HIF-1, which is one of the main effects of kalkitoxin, thus induces cellular hypoxia.
Toxicity
Kalkitoxin is ichthyotoxic to goldfish (Carassius auratus, LC50: 700nM) and to aquatic crustacean brine shrimp (Artemia salina, LC50: 150-180nM ). Kalkitoxin also has been shown to have delayed neurotoxic effects on cerebellar granule cells of the rat (LC50: 3,86nM).
Therapeutic research
Many efforts to discover cancer therapeutic drugs focus on the screening of novel biomolecules produced and isolated from various plants and animals. These isolated molecules are screened via in-vitro assays to measure their effects in standardized paradigms designed to select for the desired therapeutic effect. Kalkitoxin was originally isolated from Lyngbya majuscula as an effort to collect new molecules for testing as antitumor or antifungal agents. One of the first tests of kalkitoxin tumor-selective cytotoxicity used an in-vitro assay to test solid tumor selectivity of kalkitoxin's previously demonstrated cytotoxicity against the human colon cell line HCT-116. The assay measured the extent of differential cytotoxicity of kalkitoxin and various analogous structures by observing differential cytotoxicity against solid tumor cells, and either non-solid tumor cells such as leukemia cells or normal cells. This test yielded promising results, as kalkitoxin exhibited preferential cytotoxicity for the solid tumor cell test conditions (Colon 38, and HCT-116 cells) as compared to the non-solid tumor and normal cell conditions.
Kalkitoxin exerts this cytotoxic effect through inhibition of the mitochondrial electron transport chain complex 1. This causes the inhibition of hypoxia-induced HIF-1 activation, which is crucial in solid tumor cancers because hypoxia drives tumor angiogenesis, leading to worsening disease stages and increased resistance to treatment. HIF-1 is a transcription factor which induces expression of genes promoting oxygen availability and decreasing oxygen consumption, the effect of which counteracts cellular hypoxia. Therefore, kalkitoxin's HIF-1 inhibitory ability positions it as a potentially promising molecule to counteract the progression of some solid tumor cancers by blocking the tumor proliferative response to hypoxia. The caveat to kalkitoxin's promising anti-proliferative properties is its neurotoxic effects. At concentrations comparable to those required for tumor-selective cytotoxicity, kalkitoxin induces cell death when applied to rat cerebellar granule neurons (CGN) in culture. Kalkitoxin acts as an N-methyl-D-aspartate (NMDA) receptor agonist, and induces cytotoxicity in cultured rat CGNs at delayed time points. Therefore, this effect must be taken into account when considering kalkitoxin or its chemical derivatives for use as a therapeutic option.
References
Ion channel toxins
Cyanotoxins
Neurotoxins | Kalkitoxin | [
"Chemistry"
] | 3,868 | [
"Neurochemistry",
"Neurotoxins"
] |
51,934,343 | https://en.wikipedia.org/wiki/Photopharmacology |
History
Photopharmacology is an emerging multidisciplinary field that combines photochemistry and pharmacology. Built upon the ability of light to change the pharmacokinetics and pharmacodynamics of bioactive molecules, it aims at regulating the activity of drugs in vivo by using light. The light-based modulation is achieved by incorporating molecular photoswitches such as azobenzene and diarylethenes or photocages such as o-nitrobenzyl, coumarin, and BODIPY compounds into the pharmacophore. This selective activation of the biomolecules helps prevent or minimize off-target activity and systemic side effects. Moreover, light being the regulatory element offers additional advantages such as the ability to be delivered with high spatiotemporal precision, low to negligible toxicity, and the ability to be controlled both qualitatively and quantitatively by tuning its wavelength and intensity.
Though photopharmacology is a relatively new field, the concept of using light in therapeutic applications came into practice a few decades ago. Photodynamic therapy (PDT) is a well-established clinically practiced protocol in which photosensitizers are used to produce singlet oxygen for destroying diseased or damaged cells or tissues. Optogenetics is another method that relies on light for dynamically controlling biological functions especially brain and neural. Though this approach has proven useful as a research tool, its clinical implementation is limited by the requirement for genetic manipulation. Mainly, these two techniques laid the foundation for photopharmacology. Today, it is a rapidly evolving field with diverse applications in both basic research and clinical medicine which has the potential to overcome some of the challenges limiting the range of applications of the other light-guided therapies.
Figure 1. Schematic representation of the mechanism of (a) photopharmacology (b) photodynamic therapy, and (c) optogenetics.
The discovery of natural photoreceptors such as rhodopsins in the eye inspired the biomedical and pharmacology research community to engineer light-sensitive proteins for therapeutic applications. The development of synthetic photoswitchable molecules is the most significant milestone in the history of light-delivery systems. Scientists are continuing with their efforts to explore new photoswitches and delivery strategies with enhanced performance to target different biological molecules such as ion channels, nucleic acid, and enzyme receptors. Photopharmacology research progressed from in vitro to in vivo studies in a significantly short period of time yielding promising results in both forms. Clinical trials are underway to assess the safety and efficacy of these photopharmacological therapies further and validate their potential as an innovative drug delivery approach.
Mechanism of action
Molecular photoswitches are utilized in the field of photopharmacology, where the energetics of a molecule can be reversibly controlled with light to achieve spatial and temporal resolution of a particular effect. Photoswitches may function by undergoing photoisomerization through which light is used to conformationally adapt a molecule to a biological site, or through an environmental effect where an external factor such as a solvent effect or hydrogen bonding can selectively allow or quench an emissive state within a molecule. To visualize photophysical processes, a useful depiction is the Jablonski diagram. This is a diagram which depicts electronic and vibrational energy levels within a molecule as vertical levels and shows the possible relaxation pathways from excited states. Typically, the ground state is referred to as S0, and is drawn at the bottom of the figure with nearby vibrational excitations just above it. An absorption will promote an electron into the S1 state at any vibrational energy level, or into a higher order excited state if the absorbed energy has enough magnitude. The excited state can then undergo internal conversion which is the electronic relaxation to a lower state with the same vibrational energetics or vibrational relaxation within a state. This may be followed by an intersystem crossing wherein the electron undergoes a spin flip, or a radiative or nonradiative decay back to the ground state.
One example of an organic compound that undergoes photoisomerization is azobenzene. The structure is two phenyl rings joined with a N=N double bond and is the simplest aryl azo compound. Azobenzene and its derivatives have two accessible absorbance bands: the S1 state from a n-π* transition which can be excited into using blue light, and the S2 state from a π-π* transition that can be excited into using ultraviolet light. Azobenzene and its derivatives have two isomers, trans and cis. The trans isomer, having the phenyl rings on opposite sides of the azo double bond, is the thermally preferred isomer as there is less stereoelectronic distortion and more delocalization present. However, excitation of the trans isomer to the S2 state facilitates a shift to the cis isomer. The S1 absorption is associated with a conversion back to the trans isomer. In this way, azobenzene and its derivatives can act as reversible stores of energy by maintaining a strained configuration in the cis isomer. Modifications of the substituents on azobenzene allow the energetics of these absorptions to be tuned, and if they are engineered such that the two absorption bands overlap a single wavelength of light can be used to flip between them. There are a number of similar photoswitches which isomerize between E and Z configurations across an azo group (for instance, azobenzene and azopyrazole) or an ethylene bridge (for instance, stilbene and hemithioindigo).
Alternatively, photoswitches may themselves be emissive and exhibit environmental control over their properties. One such example is a class of ruthenium polypyridyl coordination complexes. Typically they contain two bidentate bipyridine or phenanthroline ligands and an extended phenanthroline-phenazine bidentate ligand such as dipyrido[3,2-a:2,3-c]phenazine (dppz). These complexes have an accessible metal to ligand charge transfer excited state (1MLCT) which undergoes rapid intersystem crossing to a 3MLCT state due to the strong spin-orbit coupling of the ruthenium center. These excited states are localized on the extended ligand phenazine nitrogens, and emission occurs from the 3MLCT state. Hydrogen bonding interactions such as the presence of water around these nitrogen atoms stabilizes the 3MLCT state, quenching the emission process. Thus, by controlling whether an aqueous or otherwise protic polar solvent is present, emissive behaviors can be “turned on/off”, and alternation between “bright states” and “dark states” is facilitated. This light switch behavior makes these and similar complexes of recent interest in photopharmacological applications such as photodynamic therapy.
Molecules
As previously mentioned, photopharmacology relies on the use of molecular photoswitches being incorporated into the structure of biologically active molecules which allows their potency to be controlled optically. They are introduced into the structure of bioactive compounds via insertion, extension, or bioisosteric replacement. These incorporations can be supported by structural considerations of the molecule or SAR (structure-activity relationship) analysis to determine the optimal position. Some examples of photoswitchable molecules commonly used in photopharmacology are azobenzenes, diarylethenes, and photocages.
Azobenzenes
Azobenzenes are a class of photoswitchable molecules and are used in photopharmalogical applications for their reversible photoisomerization, as described in the previous section. An example of a photoswitchable molecule that uses azobenzene is phototrexate. Phototrexate is an inhibitor of human dihydrofolate reductase and is an analogue of methotrexate, a chemotherapy agent. When in its photoactive cis form, phototrexate has been shown to be a potent antifolate and is relatively inactive when in the trans form. The azologization, or incorporation of azobenzene, of methotrexate allows for control of cytotoxic activity and is considered a step forward in developing targeted anticancer drugs with localized efficacy.
Diarylethenes
Diarylethene photoswitches have reversible cyclization and cycloreversion reactions that are photoinduced. They are a class of compounds that have aromatic functional groups bonded to each end of a carbon-carbon double bond. An example of this class of molecule that is used in photopharmacology is stilbene. Under the influence of light, stilbene switches between its two isomers (E and Z).
Figure 4. Figure showing stilbene isomerizations under light from E to Z.
Diarylethenes have been shown to have some advantages over the more researched azobenzenes switches, such as thermal irreversibility, high photoswitching efficiency, favorable cellular stability, and low toxicity. Diarylethenes have been shown to have promise in fields other than photopharmacology as well. These fields include optical data storage, optoelectronic devices, supramolecular self-assembly and anti-counterfeiting.
Photocages
A class of substances known as photocages contain “photosensitive groups, also known as 'photoremovable protecting groups", from which target substances are released upon exposure to specific wavelengths of light”. The photosensitive groups physically and chemically protect the target from being released until the molecule undergoes photoreaction. Due to these interactions with light, they are commonly used molecules in photopharmacology. More recently, they have played an important role in photoactivated chemotherapy (PACT). In PACT, photocages utilize a photoremovable protecting group that protects cytotoxic drugs until the bond is cleaved via light interaction and the cytotoxic drug is released. Some well-known photocages include “o-nitrobenzyl derivatives, coumarin derivatives, BODIPY, xanthene derivatives, quinone and diarylenes derivatives”. However, there are limitations with using photocages in clinical applications as there are not many PPGs that can be used in vivo. This is due to PPG-payload conjugates needing to have acceptable solubility and biological inertness for biocompatibility and the need for efficient uncaging above 600 nm.
Figure 5. Example of a photocage release system activated by NIR.
Application
Photopharmacology, the use of light to control the activity of drugs, has emerged as a promising approach to drug delivery and therapy. By harnessing the power of light, researchers can achieve precise control over drug release and activation, offering new possibilities for targeted and personalized treatments. This subsection explores the application of photopharmacology in drug delivery, focusing on recent advancements and potential clinical applications.
In one study, researchers designed HDAC inhibitors which can be activated or deactivated with light, providing precise therapeutic control. This approach could reduce the side effects of traditional chemotherapy by targeting inhibitors to specific body areas, potentially leading to more effective and personalized cancer treatments.
In another study, the researchers developed a strategy to attach a photoswitchable group to a common antibiotic; ciprofloxacin. By attaching the photoswitchable group, researchers can control the activity of ciprofloxacin with light. This approach could potentially lead to new ways of treating bacterial infections, with the ability to switch the antibiotic's activity on and off as needed.
In this paper an in vitro protocol to test different light wavelengths on human cancer cell lines is developed, finding that blue light most effectively inhibited cell growth. This suggests that photopharmacology could offer new cancer treatment options by targeting specific light wavelengths to modulate drug activity in tumor cells.
Another application of photopharmacology is developing a luminescent photoCORM grafted on carboxymethyl chitosan, which, when exposed to light, releases carbon monoxide (CO) to induce apoptotic death in colorectal cancer cells, demonstrating precise control over CO release for targeted cancer therapy.
Researchers developed a toolbox of photoswitchable antagonists that can interact with GPCRs, a class of proteins involved in various cellular processes. By using light to switch the activity of these antagonists, researchers can control the interaction between the antagonists and GPCRs in real time. This approach allows for precise modulation of GPCR activity, which could lead to new insights into cellular signaling pathways and potential therapeutic applications.
In another application by using light to control the assembly of nanopores, researchers can potentially regulate the flow of ions or molecules through these nanopores. This approach could have applications in various fields, including sensing, drug delivery, and nanotechnology.
Another paper reports on the use of photopharmacology to control drug activity; multifunctional fibers in the study deliver light and drugs to specific body areas. Implanted fibers activate light-responsive drugs, altering their structure, and offering precise drug delivery for conditions needing exact timing or dosage.
In another study, ligands were designed to switch their binding mode to G-quadruplex DNA upon exposure to visible light. This method could potentially modulate the activity of G-quadruplex DNA, crucial in gene expression and telomere maintenance, offering new therapeutic avenues, particularly in cancer treatment. The study underscores photopharmacology's promise in targeting specific DNA structures, suggesting G-quadruplex DNA as a viable target for future photopharmacological interventions.
Another study developed photoactivatable antibody-photoCORM conjugates targeting human ovarian cancer cells, releasing CO upon light exposure to diminish cell viability. This approach offers precise cancer cell targeting while minimizing harm to healthy tissue, showcasing the potential of photopharmacology in cancer therapy.
In another paper, a photoactivatable compound that binds to and modulates the activity of the CRY1 protein, regulating the mammalian circadian clock, was developed. By using light to control the compound's activity, researchers can potentially treat circadian rhythm disorders and related health conditions by modulating the function of CRY1. Photopharmacology involves using light to control the activity of drugs.
In another application researchers used photopharmacology to control drug release and focus on a drug interacting with tubulin, visualizing its release in real time with time-resolved serial crystallography. This technique offers insights into drug-tubulin interactions and demonstrates the potential for designing drugs with precise actions.
Future directions
The future of photopharmacology holds immense promise. It has the potential to revolutionize conventional drug therapy offering new avenues for precision medicine, treating neurological disorders, and in the field of oncology and ophthalmology. Additionally, it holds promise for the field of regenerative medicine where photoswitches can be used to modulate the activity of signaling pathways for targeted tissue repair and regeneration.
Photopharmacology will continue to grow and expand with the new discoveries and advances happening in other related fields such as synthetic chemistry, biology, nanotechnology, pharmacology, and bioengineering. While the potential of photopharmacology is vast, some challenges must be addressed to make it a clinical reality. One challenge is the development of stable and biocompatible photoswitches that are selective for their target receptors without cross-activity. It is particularly important that these photoswitchables have their absorbance bands fall within the wavelength range of 650 nm to 900 nm. Hence, optimum molecular designing of photoswitches is required to achieve the characteristics mentioned above and desired level of performance. At present, photopharmacology uses a rational drug design approach based on studying the structure-activity relationship, however, a phenotypic screening for photoswitchable drugs could also be beneficial.
In order to achieve good spatial-temporal control over drug activity there should be a significant difference between the activity of isomers. However, understanding the structural changes during the biological effects induced by photoswitching is limited. This scarcity of knowledge is also a challenge for the growth of this field, as it hampers the optimization of the activity and potency of the isomers to obtain the expected outcomes during applications.
The biggest challenge in photopharmacology is finding appropriate and effective ways to deliver light to deep tissues in the body and tissues avoiding issues such as scattering and absorption. Various strategies have been attempted in this regard, one being the development of photoswitchable ligands that respond to deep-tissue penetrating wavelengths like red or infrared light. Moreover, some recent preclinical studies have spurred the development of wireless, compact or injectable, and remotely controllable devices capable of delivering light to neural tissues with minimal damage. There are novel optofluidic systems that can simultaneously regulate both drug delivery and light activity at specific sites. Although external delivery of light is the most preferred method, the use of internal exogenous light sources such as luminescent compounds where light would be delivered directly at the site of action. This could avoid the issues related to light penetration and also enhance the degree of selectivity. In addition, this creates the opportunity to use photopharmacology as a theranostic approach that combines targeted drug delivery and molecular imaging.
References
Chemistry
Medical treatments
Medicinal chemistry
Pharmacology | Photopharmacology | [
"Chemistry",
"Biology"
] | 3,673 | [
"Biochemistry",
"Pharmacology",
"nan",
"Medicinal chemistry"
] |
51,934,751 | https://en.wikipedia.org/wiki/Amanita%20longipes | Amanita longipes is a small mushroom species of the Amanita genus. It feeds on decaying leaves of some woods and can be found around the Appalachian Mountains. It is a food source for various insects.
Description
Cap
The cap is typically around wide, is hemispheric at first then becoming broadly convex to plano-convex, occasionally also slightly depressed in center; white, pallid grayish-brown or grayish buff over disk in age, surface dull and tacky at first and becoming shiny.
Gills
The gills are usually narrowly adnate, sometimes with a decurrent line, close, whitish, becoming grayish-cream on drying, with white, floccose remnants of partial veil on edges, narrow, broad, sometimes anastomosing; the short gills are truncate to rounded truncate to attenuate to attenuate in steps, plentiful, of diverse lengths, unevenly distributed.
Stem
The stem is × , white, and tapers upward slightly to a flaring apex. The stem is decorated with easily removed, floccose material especially in upper portion; the flesh of the stem usually does not take on a color when bruised. The flesh is white, occasionally graying in damaged areas, with a firmly stuffed central cylinder, up to 7 mm wide. The ring is fibrous-floccose and rapidly evanescent. Volval remnants are absent from the bulb and the stem base or difficult to distinguish.
Toxicity
One guide lists this species' edibility as unknown but doubtful. It should be avoided as many species of the genus are deadly.
References
longipes
Fungus species | Amanita longipes | [
"Biology"
] | 337 | [
"Fungi",
"Fungus species"
] |
51,935,121 | https://en.wikipedia.org/wiki/International%20Conference%20on%20Applications%20and%20Theory%20of%20Petri%20Nets%20and%20Concurrency | Petri Nets, the International Conference on Applications and Theory of Petri Nets and Concurrency is an academic conference organized annually by the Petri net community. The conference was first organized in 1980 Strasbourg, France
Since then the conference has been organized annually. The Petri Nets Steering Committee is responsible for the conference, including selection of organisers, PC members, invited speakers, tutorials and workshops, etc.
History
1980 Strasbourg, France
1981 Bad Honnef, Germany
1982 Varenna, Italy
1983 Toulouse, France
1984 Aarhus, Denmark
1985 Espoo, Finland
1986 Oxford, UK
1987 Zaragoza, Spain
1988 Venice, Italy
1989 Bonn, Germany
1990 Paris, France
1991 Aarhus, Denmark
1992 Sheffield, UK
1993 Chicago, USA
1994 Zaragoza, Spain
1995 Torino, Italy
1996 Osaka, Japan
1997 Toulouse, France
1998 Lisbon, Portugal
1999 Williamsburg, USA
2000 Aarhus, Denmark
2001 Newcastle upon Tyne, UK
2002 Adelaide, Australia
2003 Eindhoven, The Netherlands
2004 Bologna, Italy
2005 Miami, USA
2006 Turku, Finland
2007 Siedlce, Poland
2008 Xi'an, China
2009 Paris, France
2010 Braga, Portugal
2011 Newcastle upon Tyne, UK
2012 Hamburg, Germany
2013 Milano, Italy
2014 Tunis, Tunisia
2015 Brussels, Belgium
2016 Toruń, Poland
2017 Zaragoza, Spain
2018 Bratislava, Slovakia
2019 Aachen, Germany
2020 Paris (online), France
2021 Paris, France
See also
The list of computer science conferences contains other academic conferences in computer science.
The topics of the conference cover the field of theoretical computer science.
References
External links
Petri Nets World
Petri Nets Steering Committee
38th Annual International Petri Nets Conference, Zaragoza, Spain, June 2017
40th Annual International Petri Nets Conference, Aachen, Germany, June 2019
42nd Annual International Petri Nets Conference, Paris, France, June 2020
LNCS Transactions on Petri Nets and Other Models of Concurrency (ToPNoC)
Theoretical computer science conferences
Recurring events established in 1980 | International Conference on Applications and Theory of Petri Nets and Concurrency | [
"Technology"
] | 383 | [
"Computing stubs",
"Computer conference stubs"
] |
51,935,228 | https://en.wikipedia.org/wiki/Kalicludine | Kalicludine (AsKC) is a blocker of the voltage-dependent potassium channel Kv1.2 found in the snakeslocks anemone Anemonia viridis (Anemonia sulcata), which it uses to paralyse prey.
Etymology
"Kali", abbreviated from the Latin word "kalium", equals potassium. "Cludine" means to block or to enclose, as it is derived from the Latin verb "cludere".
Source, family and homology
Kalicludine (uniprot ID: Q9TWG0) is also known as KappaPI-actitoxin-Avd3b or as Kunitz-type serine protease inhibitor kalicludine-1. Thus, kalicludines are part of the Kunitz-type inhibitor superfamily. The Kunitz-type scaffold is found both in inhibitors of proteolytic enzymes and in toxins. Other members of this superfamily are the pancreatic trypsin inhibitors (BPTI), which are potent Kunitz-type protease inhibitors, and dendrotoxins. Kalicludine has 40% homology with BPTIs. The most represented sequences of this group corresponds with kalicludine-3 and kalicludine-4, a recently found polypeptide.
A. sulcata kalicludines include AsKC1, AsKC2, and AsKC3., which are related to Bunodosoma granulifera toxin k (BgK) and Stichodactyla helianthus toxin k (ShK). A different, less abundant, protein is AsKC1a, which has a supplementary residue at the C-terminus when compared with kalicludine-1. Furthermore, a level of amino acid sequence identity and similarity of ≥43% and ≥50% was found between both A. sulcata Kunitz-type protease inhibitors SA5 II, SA5 III and AsKC1 – AsKC15.
Kalicludine has 48% identity with the amyloid A4 homologue, which is implicated in Alzheimer's disease.
Structure
The kalicludine isotoxins have similar molecular size and a similar biological function. They contain three amino acid residues that are important for trypsin binding: Lys-15, Ala-16, and Ile-19 in BPTI. AsKCs have a replacement at position 19 (Ile → Pro), which results in less inhibitory action than BPTI.
Mode of action
Kalicludine is stored in nematocysts or located in extracellular regions. It is known to be a dual-function toxin, able to inhibit both the serine protease trypsin (Kd=30 nM) and the voltage-gated potassium channels Kv1.2/KCNA2 (IC50=2800 nM). Kalicludines and dendrotoxins compete for binding to these Kv channels.
The kalicludine sequence is homologous to the sequence of dendrotoxins, in particular DTX 1 (dendrotoxin 1), potent blockers of Kv channels. Kalicludines have from 38 to 42% homologies with DTX. Both kalicludines and dendrotoxins increase the release of acetylcholine and enhance the duration of action potentials (AP).
Toxicity and symptoms
Kv channel blocking dendrotoxins, and thus possibly also kalicludines, often lead to overstimulation of the cholinergic system, and subsequently to neuromuscular block and cardiovascular depression.
References
Ion channel toxins
Neurotoxins | Kalicludine | [
"Chemistry"
] | 770 | [
"Neurochemistry",
"Neurotoxins"
] |
51,935,974 | https://en.wikipedia.org/wiki/Hockey-stick%20identity | In combinatorics, the hockey-stick identity, Christmas stocking identity, boomerang identity, Fermat's identity or Chu's Theorem, states that if are integers, then
The name stems from the graphical representation of the identity on Pascal's triangle: when the addends represented in the summation and the sum itself are highlighted, the shape revealed is vaguely reminiscent of those objects (see hockey stick, Christmas stocking).
Formulations
Using sigma notation, the identity states
or equivalently, the mirror-image by the substitution , and by using the identify :
Proofs
Generating function proof
Let . Then, by the partial sum formula for geometric series, we find that
.
Further, by the binomial theorem, we also find that
.
Note that this means the coefficient of in is given by .
Thus, the coefficient of in the left hand side of our first equation can be obtained by summing over the coefficients of from each term, which gives
Similarly, we find that the coefficient of on the right hand side is given by the coefficient of in , which is
Therefore, we can compare the coefficients of on each side of the equation to find that
Inductive and algebraic proofs
The inductive and algebraic proofs both make use of Pascal's identity:
Inductive proof
This identity can be proven by mathematical induction on .
Base case
Let ;
Inductive step
Suppose, for some ,
Then
Algebraic proof
We use a telescoping argument to simplify the computation of the sum:
Combinatorial proofs
Proof 1
Imagine that we are distributing indistinguishable candies to distinguishable children. By a direct application of the stars and bars method, there are
ways to do this. Alternatively, we can first give candies to the oldest child so that we are essentially giving candies to kids and again, with stars and bars and double counting, we have
which simplifies to the desired result by taking and , and noticing that :
Proof 2
We can form a committee of size from a group of people in
ways. Now we hand out the numbers to of the people. We can then divide our committee-forming process into exhaustive and disjoint cases based on the committee member with the lowest number, . Note that there are only people without numbers, meaning we must choose at least one person with a number in order to form a committee of people. In general, in case , person is on the committee and persons are not on the committee. The rest of the committee can then be chosen in
ways. Now we can sum the values of these disjoint cases, and using double counting, we obtain
See also
Pascal's identity
Pascal's triangle
Leibniz triangle
Vandermonde's identity
Faulhaber's formula, for sums of arbitrary polynomials.
References
External links
On AOPS
On StackExchange, Mathematics
Pascal's Ladder on the Dyalog Chat Forum
Theorems in combinatorics
Algebraic identities
Articles containing proofs
Factorial and binomial topics | Hockey-stick identity | [
"Mathematics"
] | 620 | [
"Factorial and binomial topics",
"Theorems in combinatorics",
"Algebraic identities",
"Combinatorics",
"Theorems in discrete mathematics",
"Articles containing proofs",
"Mathematical identities"
] |
51,937,029 | https://en.wikipedia.org/wiki/Oilfield%20scale%20inhibition | Oilfield scale inhibition is the process of preventing the formation of scale from blocking or hindering fluid flow through pipelines, valves, and pumps used in oil production and processing. Scale inhibitors (SIs) are a class of specialty chemicals that are used to slow or prevent scaling in water systems. Oilfield scaling is the precipitation and accumulation of insoluble crystals (salts) from a mixture of incompatible aqueous phases in oil processing systems. is a common term in the oil industry used to describe solid deposits that grow over time, blocking and hindering fluid flow through pipelines, valves, pumps etc. with significant reduction in production rates and equipment damages. Scaling represents a major challenge for flow assurance in the oil and gas industry. Examples of oilfield scales are calcium carbonate (limescale), iron sulfides, barium sulfate and strontium sulfate. Scale inhibition encompasses the processes or techniques employed to treat scaling problems.
Background
The three prevailing water-related problems that upset oil companies today are corrosion, gas hydrates and scaling in production systems. The reservoir water has a high composition of dissolved minerals equilibrated over millions of years at constant physicochemical conditions. As the reservoir fluids are pumped from the ground, changes in temperature, pressure and chemical composition shift the equilibria and cause precipitation and deposition of sparingly soluble salts that build up over time with the potential of blocking vital assets in the oil production setups. Scaling can occur at all stages of oil/gas production systems (upstream, midstream and downstream) and causes blockages of well-bore perforations, casing, pipelines, pumps, valves etc. Severe scaling issues have been reported in Russia and certain North Sea production systems.
Types of scales
Two main classifications of scales are known; inorganic and organic scales and the two types are mutually inclusive, occurring simultaneously in the same system, referred to as mixed scale. Mixed scales may result in highly complex structured scales that are difficult to treat. Such scales require aggressive, severe and sometimes costly remediation techniques. Paraffin wax, asphaltenes and gas hydrates are the most often encountered organic scales in the oil industry. This article focuses on the simplest and common form of scales encountered; inorganic scales.
Inorganic scale
Inorganic scales refer to mineral deposits that occur when the formation water mixes with different brines such as injection water. The mixing changes causes reaction between incompatible ions and changes the thermodynamic and equilibrium state of the reservoir fluids. Supersaturation and subsequent deposition of the inorganic salts occur. The most common types of inorganic scales known to the oil/gas industry are carbonates and sulfates; sulfides and chlorites are often encountered.
While the solubility of most inorganic salts (NaCl, KCl, ...) increases with temperature (endothermic dissolution reaction), some inorganic salts such as calcium carbonate and calcium sulfate have also a retrograde solubility, i.e., their solubility decreases with temperature. In the case of calcium carbonate, it is due to the degassing of CO2 whose solubility decreases with temperature as is the case for most of the gases (exothermic dissolution reaction in water). In calcium sulfate, the reason is that the dissolution reaction of calcium sulfate itself is exothermic and therefore is favored when the temperature decreases (then, the dissolution heat is more easily evacuated; see Le Chatelier's principle). In other terms, the solubility of calcium carbonate and calcium sulfate increases at low temperature and decreases at high temperature, as it is also the case for calcium hydroxide (portlandite), often cited as a didactic case study to explain the reason of retrograde solubility.
Calcium carbonate scale
Water, noted for its high solvation power can dissolve certain gases such as carbon dioxide (CO2) to form aqueous CO2(aq). Under the right conditions of temperature and/or pressure, H2O and CO2(aq) molecules react to yield carbonic acid (H2CO3) whose solubility increases at low temperature and high pressure. The slightest changes in pressure and temperature dissolves H2CO3(aq) in water according to equation (3) to form hydronium and bicarbonate (HCO3−(aq)) ions.
CO2(aq) + H2O(l) ↔ H2CO3(aq)
H2CO3(aq) ↔ H+(aq) + HCO3−(aq)
2 HCO3−(aq) ↔ CO32−(aq) + H2O(l) + CO2(g)
Ca2+(aq) + CO32−(aq) ↔ CaCO3(s)
The two reactions (2) and (4) describe the equilibrium between bicarbonate ions (HCO3−), which are highly soluble in water and calcium carbonate (CaCO3) salt. According to Le Chatelier's principle, drilling operations and extraction of the oil from the well bore decreases the pressure of the formation and the equilibrium shifts to the right (3) to increase the production of CO2 to offset the change in pressure. After years of oil production, wells may experience significant pressure drops resulting in large CaCO3 deposits as the equilibrium shifts to offset the pressure changes.
Sulfate scales
Sulfates of Group (II) metal ions (M2+), generally decrease in solubility down the group. The most difficult scales to remove are those of Barium sulfate because of its high insolubility forming very hard scale deposits. A general representation of the reaction is summarized in reaction:
5. M2+(aq) + SO42−(aq) → MSO4(s)
Sulfate scale usually forms when formation water and injected seawater mix together. The relationship between these and the degree of supersaturation is crucial in estimating the amount of sulfate salts that will precipitate in the system. Seawater has a high concentration of sulfate ions and mixing with formation water with many Ca2+ and other M2+ ions in the formation water. Severe problems with sulfate scale are common in reservoirs where seawater has been injected to enhance oil recovery.
Due to its relatively high solubility in water, Calcium sulfate is the easiest sulfate scale to remove chemically as compared to strontium and barium sulfate. Scale crystals are initially dispersed in production systems until accumulation of stable crystals of insoluble sulfates and scale growth occur at nucleation centers. Uneven pipeline surfaces and production equipment such as pumps and valves cause rapid scale growth to levels that can block pipelines.
The scaling-tendency of an oil-well can be predicted based on the prevailing conditions such as pH, temperature, pressure, ionic strength and the mole fraction of CO2 in the vapor and aqueous phases. For instance the saturation index for CaCO3 scale is calculated using the formula;
Fs= {[Ca2+][CO32−]}/Ksp
Where Fs is the scale saturation ratio, defined as the ratio of the activity product to the solubility product of the salt. Activity is defined as the product of the activity coefficients and the concentrations of Ca2+ and SO42− ions. The ionic strength is a measure of the concentration of the dissociated ions dissolved in water also called as “total dissolved solids” (TDS).
Scale remediation
Different oilfield scale remediation techniques are known but majority are based on three basic themes:
Sulfate ion sequestering from sea injection waters
Chemical or mechanical Scale removal/dissolution
Application of Scale Inhibitors (SIs) for scale prevention
The first two methods may be used for short-term treatment and effective for mild-scaling conditions, however, continuous injection or chemical scale squeeze treatment with SIs have been proven over the years to be the most efficient and cost-effective preventative technique.
Scale inhibitors
Scale inhibitors are specialty chemicals that are added to oil production systems to delay, reduce and/or prevent scale deposition. acrylic acid polymers, maleic acid polymers and phosphonates have been used extensively for scale treatment in water systems due to their excellent solubility, thermal stability and dosage efficiency. In the water treatment industry, the major classes of SIs have inorganic phosphate, organophosphorous and organic polymer backbones and common examples are PBTC (phosphonobutane-1,2,4-tricarboxylic acid), ATMP (amino-trimethylene phosphonic acid) and HEDP (1-hydroxyethylidene-1,1-diphosphonic acid), polyacrylic acid (PAA), phosphinopolyacrylates (such as PPCA), polymaleic acids (PMA), maleic acid terpolymers (MAT), sulfonic acid copolymers, such as SPOCA (sulfonated phosphonocarboxylic acid), polyvinyl sulfonates. Two common oilfield mineral SIs are Poly-Phosphono Carboxylic acid (PPCA) and Diethylenetriamine- penta (methylene phosphonic acid) (DTPMP).
Inhibition of calcium carbonate scale deposition and crystal studies of its polymorphs have been conducted. Different SIs are designed for specific scaling conditions and biodegradability properties. The inhibitor molecules essentially bind ions in aqueous phase of production fluids that could potentially precipitate as scales. For instance, to bind positively charged ions in the water, anions must be present in the inhibitor molecular backbone structure and vice versa. Group (II) metal ions are commonly sequestered by SIs with the following functionalities;
- Phosphonate ions (-PO3H−)
- Phosphate ions (-OPO3H−)
- Phosphonate ions (-PO2H−)
- Sulphonate ions (-SO3−)
- Carboxylate ions (-CO2−)
A SI with a combination of two or more of these functional groups is more efficient in managing scale problems. Usually the sodium salts of the carboxylic derivatives are synthesized as the anionic derivatives and are known to be the most effective due to their high solubilities. Interactions of these functional groups tend to prevent the crystal growth sites using dissociated or un-dissociated groups. The dissociation state is determined by the pH of the system, hence knowledge of the pKa values of the chemicals are important for different pH environments. Again, the inhibition efficiency of the SI depends on its compatibility with other production chemicals such as corrosion inhibitors.
Environmental considerations
Generally, the environmental impacts of SIs are complicated further by combination of other chemicals applied through exploratory, drilling, well-completion and start-up operations. Produced fluids, and other wastes from oil and gas operations with high content of different toxic compounds are hazardous and harmful to human health, water supplies, marine and freshwater organisms. For instance trails of increased turbidity resulting from oil and gas exploratory activities on the eastern shelf of Sakhalin in Russia have been reported with consequential adverse effects on salmon, cod and littoral amphipods.
Efforts to develop more environmentally friendly SIs have been made since the late 1990s and an increasing number of such SIs are becoming commercially available. Recent environmental awareness over the past 15 years has resulted in the production and application of more environmentally friendly SIs, otherwise called 'Green Scale Inhibitors' (GSI). These GSIs are designed to have reduced bio-accumulating and high biodegradability properties and therefore reduce pollution of the waters around oil production systems. Phosphate ester SIs, commonly employed for treating calcium carbonate scales are known to be environmentally friendly but poor inhibition efficiency. Release of SIs containing Nitrogen and Phosphorus distorts the natural equilibrium of the immediate water body with adverse effects on aquatic life.
Another alternative, polysaccharide SIs meet the requirements for environmentally friendly materials; they contain no Phosphorus or Nitrogen and are noted for their non-toxic, renewable, and biodegradable properties. Carboxymethyl inulin (CMI), which is isolated from the roots of Inula helenium has been used in oil exploration and its very low toxicity and crystal growth inhibition power has been reported for treating calcite scales. Examples of poorly biodegradable SIs such as the amino-phosphonate and acrylate-based SIs are being phased-out by stringent environmental regulations as demonstrated in the North sea by Norway zero discharge policy.
Another modern alternative to SI use for environmental protection is the development of materials or coatings that intrinsically resist formation of inorganic scale to begin with. A variety of strategies can be used to accomplish this aim, including engineering of wettability properties and engineering of epitaxial properties to prevent mineral growth or to make minerals easier to remove following growth. Recent work has demonstrated that some classes of hydrophobic and superhydrophobic surfaces can cause self-ejection of scale grown during evaporation
References
Petroleum industry
Chemistry
Engineering | Oilfield scale inhibition | [
"Chemistry"
] | 2,721 | [
"Petroleum industry",
"Petroleum",
"Chemical process engineering"
] |
51,948,073 | https://en.wikipedia.org/wiki/2014%20UZ224 | is a trans-Neptunian object and possible dwarf planet orbiting in the scattered disc of the outermost Solar System. , it is approximately from the Sun, and will slowly decrease in distance until it reaches its perihelion of 38 AU in 2142. The discoverers have nicknamed it "DeeDee" for "Distant Dwarf".
was discovered by a team led by David Gerdes using data collected by the large camera Dark Energy Camera (DECam). It has a diameter of ~ and reflects just 13 percent of the sunlight that hits it. Since the numbering of in May 2019, may be the largest unnumbered object in the Solar System as of July 2024 (though see ). The earliest known precovery observations of were taken at the Mauna Kea Observatory on 15 October 2006.
Orbit
It orbits the Sun once every approximately 1,100 years and is the second farthest object from the Sun with a stable orbit. Its perihelion is almost as close as Pluto’s aphelion and will reach it on the 22nd of May in 2142.
Numbering and naming
As of 2024, this minor planet has neither been numbered nor named by the Minor Planet Center.
See also
List of Solar System objects most distant from the Sun
List of Solar System objects by greatest aphelion
References
External links
2014 UZ224 ("DeeDee") Fact Sheet
Minor planet object articles (unnumbered)
20140819 | 2014 UZ224 | [
"Physics",
"Astronomy"
] | 297 | [
"Concepts in astronomy",
"Unsolved problems in astronomy",
"Possible dwarf planets"
] |
51,952,557 | https://en.wikipedia.org/wiki/Attract-kill%20pattern | An attract-kill pattern is essentially a biological interaction between plant roots and pathogens where plants entice pathogens towards their roots, to ultimately neutralize them. This has been seen to have an important role in the suppression of diseases such as Phytophthora in intercropping systems.
An example of this process can be seen in recent research from Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China where they indicated that maize roots attracted the zoospores of Phytophthora capsici and inhibited their motility while also causing cystospores lysis. The phenomenon has been found in various interactions between roots of non-host plant and Phytophthora.
Mechanism
The attract- kill pattern entails plants having to rely on chemical signals or pheromone's to lure pathogens towards their roots. Following the arrival of a given pathogen plants either immobilize or lyse the incoming pathogen to prevent their ability to infect a given host plant. Maize roots for example attract zoospores of Phytophthora capsici and inhibited their motility to prevent the infection of host plant species
Pest Management
Reducing the amount of pesticides used in the environment is the major motivation for uncovering the successfulness of methods such as attract-kill. The attract-kill method is used in pest management and eradication of invasive species. This method combines sex pheromone and a killing agent such as a pathogen or insecticide to lure large numbers of pests to a specific area to ultimately eradicate them. Atrracts used to lure and then kill pests are commonly either crude baits or synthetic semiochemicals. This method is highly effective in controlling small, low-density, isolated populations. Thus, it is compelling for long-term pest management.
References
Li C, He X, Zhu S, et al. Crop diversity for yield increase[J]. PLoS ONE, 2009, 4(11):e8049.
Li X, Wang X, Dai C, et al. Effects of intercropping with Atractylodes lancea and application of bio-organic fertiliser on soil invertebrates, disease control and peanut productivity in continuous peanut cropping field in subtropical China[J]. Agroforestry systems, 2014, 88(1): 41–52.
Yang M, Zhang Y, Qi L, et al. Plant-plant-microbe mechanisms involved in soil-borne disease suppression on a maize and pepper intercropping system[J]. PLoS ONE, 2014,9(12): e115052.
Ding X, Yang M, Huang H, et al. Priming maize resistance by its neighbors: activating 1,4-benzoxazine-3-ones synthesis and defense gene expression to alleviate leaf disease[J]. Frontiers in Plant Science, 2015, 6.
El-Sayed, A. M., D. M. Suckling, J. A. Byers, E. B. Jang, and C. H. Wearing. 2009. “Potential of ‘Lure and Kill’ in Long-Term Pest Management and Eradication of Invasive Species.” Journal of Economic Entomology 102 (3): 815–35. .
Gregg, Peter C.; Del Socorro, Alice P.; Landolt, Peter J. (2018-01-07). "Advances in Attract-and-Kill for Agricultural Pests: Beyond Pheromones". Annual Review of Entomology. 63: 453–470. doi:10.1146/annurev-ento-031616-035040. ISSN 1545-4487. PMID 29058978.
Manuel Campos, Thomas W. Phillips, Attract-and-Kill and Other Pheromone-Based Methods to Suppress Populations of the Indianmeal Moth (Lepidoptera: Pyralidae), Journal of Economic Entomology, Volume 107, Issue 1, 1 February 2014, Pages 473–480, https://doi.org/10.1603/EC13451
Plant ecology
Maize diseases
Phytophthora
Phytopathology | Attract-kill pattern | [
"Biology"
] | 869 | [
"Plant ecology",
"Plants"
] |
51,952,938 | https://en.wikipedia.org/wiki/BP%20Crucis | BP Crucis (x-ray source GX 301-2) is an X-ray binary system containing a blue hypergiant and a pulsar.
System
BP Crucis is considered as the optical counterpart to the X-ray source GX 301-2. The system consists of a massive hypergiant star and a neutron star in an eccentric 41.5 day orbit. The distance is likely to be between three and four thousand parsecs. It is heavily reddened and has a K-band infrared magnitude of 5.72.
There is a mass transfer from the hypergiant to the pulsar which occurs via a dense accretion disc. This produces a cyclotron effect with electron energies of 37 and 48 keV.
Variability
The system shows both optical and x-ray variability. Although no eclipses are observed, the x-ray luminosity varies during the orbit with large x-ray flares being observed during periastron passages. The system is an optical variable showing brightness changes of up to 0.08 magnitudes at visible wavelengths. These have been attributed to ellipsoidal variations as the hypergiant rotates and to α Cygni variability. There is an intrinsic pseudo-period of 11.9 days as well as small variations corresponding to the orbital period. That X-ray emission comes not from the neutron star itself, but rather represent a radiation re-emitted by optically thick accretion shell.
Properties
BP Crucis is around 43 times as massive as the Sun, it is also one of the most luminous stars known in the Galaxy, with an estimated bolometric luminosity of around 470,000 times that of the Sun and a radius 70 times that of the Sun.
The neutron star appears to belong to the "high mass" variety being at least . It is very likely to have a mass less than as the theoretical maximum mass based on the equation of state for a neutron star. The pulsar has a spin period of 685 seconds, but shows relatively large spindown rates thought to be due to its strong magnetic field, and also occasional spinups due to interaction with the accretion disk. It is calculated that a slowly spinning neutron star could be spun up to the current rotation rate by accretion in only ten years.
References
External links
Swift/BAT transient monitor results
Crux
B-type hypergiants
Emission-line stars
Crucis, BP
J12263756-6246132
Rotating ellipsoidal variables
X-ray binaries
Pulsars | BP Crucis | [
"Astronomy"
] | 525 | [
"Crux",
"Constellations"
] |
51,953,424 | https://en.wikipedia.org/wiki/FK1012 | FK1012 is a dimer consisting of two molecules of tacrolimus (FK506) linked via their vinyl groups. It is used as a research tool in chemically induced dimerization applications. FK1012 is a chemical inducer of dimerization (CID) which makes the protein capable of dimerization or oligomerization of fusion proteins containing one or more FKBP12 domains. It is used in pharmacology to act as a mediator in the formation of FK506 dimer. FK506 binding proteins (FKBPs) do not normally form dimers but can be caused to dimerize in the presence of FK1012. Genetically engineered proteins based on FKBPs can be used to manipulate protein localization, signaling pathways and protein activation.
References
Further reading
Macrolides
Dimers (chemistry)
Heterocyclic compounds with 3 rings
Piperidines
Tetrahydropyrans
Cyclohexanols
Methoxy compounds | FK1012 | [
"Chemistry",
"Materials_science"
] | 201 | [
"Dimers (chemistry)",
"Polymer chemistry"
] |
51,954,801 | https://en.wikipedia.org/wiki/Appium | Appium is an open source automation tool for running scripts and testing native applications, mobile-web applications and hybrid applications on Android or iOS using a webdriver.
History
Appium was originally developed by Dan Cuellar in 2011 under the name "iOSAuto", written in the C# programming language. The program was open-sourced in August 2012 using the Apache 2 license. In January 2013, Sauce Labs agreed to fund Appium's development and motivated its code to be rewritten using Node.js.
Appium won the 2014 Bossie award of InfoWorld for the best open source desktop and mobile software. Appium was also selected as an Open Source Rookie of the Year by Black Duck Software.
In October 2016, Appium joined the JS Foundation. Initially as a mentor program, it graduated in August 2017.
References
External links
Automation software
Software testing tools
Unit testing frameworks | Appium | [
"Engineering"
] | 182 | [
"Automation software",
"Automation"
] |
63,231,005 | https://en.wikipedia.org/wiki/Convexity%20%28algebraic%20geometry%29 | In algebraic geometry, convexity is a restrictive technical condition for algebraic varieties originally introduced to analyze Kontsevich moduli spaces in quantum cohomology. These moduli spaces are smooth orbifolds whenever the target space is convex. A variety is called convex if the pullback of the tangent bundle to a stable rational curve has globally generated sections. Geometrically this implies the curve is free to move around infinitesimally without any obstruction. Convexity is generally phrased as the technical condition
since Serre's vanishing theorem guarantees this sheaf has globally generated sections. Intuitively this means that on a neighborhood of a point, with a vector field in that neighborhood, the local parallel transport can be extended globally. This generalizes the idea of convexity in Euclidean geometry, where given two points in a convex set , all of the points are contained in that set. There is a vector field in a neighborhood of transporting to each point . Since the vector bundle of is trivial, hence globally generated, there is a vector field on such that the equality holds on restriction.
Examples
There are many examples of convex spaces, including the following.
Spaces with trivial rational curves
If the only maps from a rational curve to are constants maps, then the pullback of the tangent sheaf is the free sheaf where . These sheaves have trivial non-zero cohomology, and hence they are always convex. In particular, Abelian varieties have this property since the Albanese variety of a rational curve is trivial, and every map from a variety to an Abelian variety factors through the Albanese.
Projective spaces
Projective spaces are examples of homogeneous spaces, but their convexity can also be proved using a sheaf cohomology computation. Recall the Euler sequence relates the tangent space through a short exact sequence
If we only need to consider degree embeddings, there is a short exact sequence
giving the long exact sequence
since the first two -terms are zero, which follows from being of genus , and the second calculation follows from the Riemann–Roch theorem, we have convexity of . Then, any nodal map can be reduced to this case by considering one of the components of .
Homogeneous spaces
Another large class of examples are homogenous spaces where is a parabolic subgroup of . These have globally generated sections since acts transitively on , meaning it can take a bases in to a basis in any other point , hence it has globally generated sections. Then, the pullback is always globally generated. This class of examples includes Grassmannians, projective spaces, and flag varieties.
Product spaces
Also, products of convex spaces are still convex. This follows from the Künneth theorem in coherent sheaf cohomology.
Projective bundles over curves
One more non-trivial class of examples of convex varieties are projective bundles for an algebraic vector bundle over a smooth algebraic curvepg 6.
Applications
There are many useful technical advantages of considering moduli spaces of stable curves mapping to convex spaces. That is, the Kontsevich moduli spaces have nice geometric and deformation-theoretic properties.
Deformation theory
The deformations of in the Hilbert scheme of graphs has tangent space
where is the point in the scheme representing the map. Convexity of gives the dimension formula below. In addition, convexity implies all infinitesimal deformations are unobstructed.
Structure
These spaces are normal projective varieties of pure dimension
which are locally the quotient of a smooth variety by a finite group. Also, the open subvariety parameterizing non-singular maps is a smooth fine moduli space. In particular, this implies the stacks are orbifolds.
Boundary divisors
The moduli spaces have nice boundary divisors for convex varieties given by
for a partition of and the point lying along the intersection of two rational curves .
See also
Stable curve
Moduli space
Gromov–Witten invariant
Quantum cohomology
Moduli of curves
References
External links
Gromov-Witten Classes, Quantum Cohomology, and Enumerative Geometry
Notes on Stable Maps and Quantum Cohomology
Algebraic geometry | Convexity (algebraic geometry) | [
"Mathematics"
] | 824 | [
"Fields of abstract algebra",
"Algebraic geometry"
] |
63,231,678 | https://en.wikipedia.org/wiki/2%2C2%27-Dipyridylamine | 2,2′-Dipyridylamine is an organic compound with the formula (C5H4N)2NH. It consists of a pair of 2-pyridyl groups (C5H4N) linked to a secondary amine. The compound forms a range of coordination complexes. Its conjugate base, 2,2′-dipyridylamide, forms extended metal atom chains.
Formation
2,2′-Dipyridylamine can be formed by heating pyridine with sodium amide. Alternatively, 2-aminopyridine can be heated with 2-chloropyridine over barium oxide.
References
2-Aminopyridines
Chelating agents | 2,2'-Dipyridylamine | [
"Chemistry"
] | 148 | [
"Chelating agents",
"Process chemicals"
] |
63,232,700 | https://en.wikipedia.org/wiki/Chiara%20Daraio | Chiara Daraio is an Italian-American materials scientist and acoustical engineer. She is the G. Bradford Jones Professor of Mechanical Engineering and Applied Physics at the California Institute of Technology.
Contributions
Daraio's research develops new materials that combine intriguing chemical composition with a designed architecture at the micro- and macro-scales. Some of her contributions include a version of Newton's cradle that can generate "sound bullets"—sound waves focused tightly enough to disrupt matter; walls filled with ball bearings that can pass sound in only one direction; 3d-printed self-assembling rolling robots; solar panels for space missions made of a shape-memory polymer that unfolds in sunlight; and heat-sensitive artificial skin made out of pectin for both robotic and prosthetic uses. Her work has applications in soft robotics, medical devices, and vibration absorption.
Education and career
Daraio earned her undergraduate degree, or laurea, in mechanical engineering from the Marche Polytechnic University in 2001, and a Ph.D. in materials science and engineering in 2006 from the University of California, San Diego. Her dissertation, Design of materials: Configurations for enhanced phononic and electronic properties, was jointly supervised by Professors Sungho Jin and Vitali F. Nesterenko.
She joined the California Institute of Technology (Caltech) faculty in 2006, and has remained there since with a leave from 2013 to 2016, to take a chair of Mechanics and Materials at ETH Zurich. At Caltech, she was initially in the Aeronautics and Applied Physics department, where she was promoted to full professor in 2010; she then moved to the Department of Mechanical Engineering and Applied Physics in 2016. She currently serves as the G. Bradford Jones Professor in the Division of Engineering and Applied Science and serves as the Caltech Director of the NSF Center to Stream Healthcare in Place (C2SHIP).
Recognitions
In 2018, Daraio won the UC San Diego Mechanical and Aerospace Engineering Outstanding Alumna Award, "for outstanding achievements in mechanical metamaterials and materials science".
Daraio received a Presidential Early Career Award for Scientists and Engineers (PECASE) from President Obama in 2012.
She was elected as a Sloan Research Fellow in 2011.
In 2010, Popular Science recognized Daraio as one of its “Brilliant 10” and she received an ONR Young Investigator Award.
She won the NSF CAREER award in 2009.
Daraio also won the Felice De Carli Medal of the Italian Metallurgical Society in 2006, and the Richard von Mises Prize of the Gesellschaft für Angewandte Mathematik und Mechanik in 2008.
References
External links
Daraio Research Group
Year of birth missing (living people)
Living people
American acoustical engineers
American materials scientists
Italian materials scientists
Women materials scientists and engineers
University of California, San Diego alumni
California Institute of Technology faculty
Recipients of the Presidential Early Career Award for Scientists and Engineers | Chiara Daraio | [
"Materials_science",
"Technology"
] | 594 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
63,233,180 | https://en.wikipedia.org/wiki/Darvadstrocel | Darvadstrocel, sold under the brand name Alofisel, is a medication used to treat complex perianal fistulas in adults with non-active/mildly active luminal Crohn's disease when fistulas have shown an inadequate response to at least one conventional or biologic therapy. It contains mesenchymal stem cells from fat tissue of adult donors.
It was approved for use in the European Union in March 2018. The approval was spearheaded by data published in the ADMIRE-CD trial. Darvadstrocel was withdrawn from the EU market in December 2024.
It was approved for use in Japan by Japan's Ministry of Health, Labour and Welfare (MHLW) in September 2021.
Medical use
Darvadstrocel has been approved by the European Union for the treatment of adults with complex Crohn's perianal fistulas after conventional or biological medications have not worked.
Mechanism of action
Darvadstrocel works by reducing inflammation and facilitating the growth of tissue in the fistula tract.
History
ADMIRE-CD
The ADMIRE-CD trial was a phase III trial that assessed the safety and efficacy of darvadstrocel vs. placebo in adults with complex perianal fistulas with Crohn's disease. The study randomized a total of 212 patients. 107 patients were given darvadstrocel and 105 patients were given placebo.
After one year, the study found darvadstrocel to be effective in closing external fistula openings, compared to placebo. Patients taking darvadstrocel had a combined remission of 56.3% and clinical remission of 59.2%. The placebo controls had a combined remission of 38.6% and clinical remission of 41.6%.
INSPECT
Published in 2022, the INSPECT study is a retrospective study that evaluated the long-term effectiveness and safety of darvadstrocel in patients with perianal fistulas in Crohn's disease that were treated in the ADMIRE-CD trial. The study data showed that darvadstrocel or the maintenance treatment used can have long term clinical remission in patients.
ADMIRE-CD II
Society and culture
Legal status
Darvadstrocel is approved for medical use in the European Union, Israel, Switzerland, Serbia, the United Kingdom, and Japan. Darvadstrocel was withdrawn from the European Union market in December 2024.
References
Further reading
External links
Orphan drugs
Stem cells
Withdrawn drugs | Darvadstrocel | [
"Chemistry"
] | 515 | [
"Drug safety",
"Withdrawn drugs"
] |
63,233,486 | https://en.wikipedia.org/wiki/1942%20Herefordshire%20TRE%20Halifax%20crash | V9977 was an Handley Page Halifax II that had been sent to the Telecommunications Research Establishment (TRE) at RAF Defford to be used as a flying testbed for the H2S radar.
On the afternoon of 7 June 1942, one of its Rolls-Royce Merlin engines caught fire and led to the aircraft crashing near the England-Wales border, killing all eleven crew-members. Among the dead was Alan Blumlein of EMI, who was well known as the inventor of stereophonic sound recording and the 405-line television system used in the UK until 1985.
Investigators determined that improper engine maintenance/assembly procedures caused the accident. It remains the deadliest crash in the history of military test flight in the UK.
History
Construction
V9977 was an early model Halifax II, which introduced the more powerful Merlin XX engine and a number of other detail changes over the original model.
Chosen for H2S
At a meeting on 23 December 1941, the Secretary of State for Air, Archibald Sinclair, directed the TRE should direct their work on H2S radar towards the new four-engine bombers, Shorts Stirling, Handley Page Halifax and Avro Lancaster. Immediately thereafter, Philip Dee, B J O'Kane and Geoffrey Hensby visited the Aeroplane and Armament Experimental Establishment at Boscombe Down to examine the available aircraft and concluded that the Halifax had the best possibilities for mounting the scanner in different locations for testing.
On 1 January 1942, Bernard Lovell received orders from Albert Rowe, director of the TRE, to take over the direction of H2S. Three days later he visited Handley Page with Bob King, a TRE fitter who was well acquainted with the installation of test systems on a variety of aircraft, and Whitaker from Nash & Thompson, who were building the scanner system. They had collectively planned for the radar to be installed in a large long radome under the aircraft.
They were met at the factory by a team of high-ranking members of the Halifax design team, including the chief designer, who was outraged at the idea of installing a huge radar scanner on a design built to be as fast as possible while carrying a huge bombload. The TRE team replied that it would be better to place a few bombs on the target than a huge load in a field, but could not explain much beyond that as they were under orders not to give away any details of the system. It is not recorded what arguments may have occurred within the company, but the direction from Prime Minister Churchill giving H2S the highest national priority overrode any complaints.
V9977 landed at RAF Hurn on 27 March 1942 already modified with the perspex radome. The electronics had been assembled at Leeson House as early as January and was being tested in Bristol Blenheim V6000. A second example was fit to V9977 by 27 March, awaiting the new hydraulic scanner from Nash & Thompson which arrived on 16 April. After some debugging, the system was operational the next day, but performed very poorly, with towns becoming visible at only from an altitude of 8,000 ft.
It was during this period that plans were made to move the TRE away from its exposed location on the English south coast to a more inland location. After considerable searching, Malvern was finally selected and the TRE moved en masse in May 1942. Their experimental aircraft moved from Hurn to RAF Defford. Further work on the system continued to improve the effective range, and by early June they were achieving .
The crash
On the weekend of 6 and 7 June, Lovell and the team met with Alan Blumlein and two of his associates from EMI to examine the system with an eye to beginning production. After the EMI team left to return to their hotel, Lovell flew in V9977 and received strong returns from Gloucester, Cheltenham and several other towns at previously invisible ranges.
The EMI team decided they should see this for themselves, and took off in V9977 at about 2:50 pm on the 7th heading for the Bristol Channel. At 4:20 pm the aircraft was seen over the Forest of Dean with its outboard starboard engine on fire. Shortly after, the left wing broke off and the aircraft rolled over and crashed in a field on the Courtfield estate in Lydbrook near Welsh Bicknor on the north side of the River Wye. All aboard were killed.
News of the crash did not reach Defford until 7:35. At 9 pm, Lovell and O'Kane were driven to the site to retrieve the top secret cavity magnetron from the wreckage.
Investigations
Due to the secret nature of the aircraft, for many years the only information available on the crash was a single index card at the Ministry of Defence that stated the accident occurred when the crew attempted to restart a failed engine which then set on fire. The extinguishers did not work and it appeared that the bottles had not been filled, and it was suggested they might have been delivered empty and never checked. They postulated that they attempted to restart the engine in order to supply power for "special equipment to enable experiment to be continued". The lack of detail led Blumlein's wife and Isaac Shoenberg, head of EMI's research division, to suspect sabotage.
In the 1980s, members of the Royal Radar Establishment, which had taken over the TRE in 1953, began their own investigation. This was led by W.H. Sleigh, who retired in 1984 and spent the next year meticulously following up every lead. Among the bits of evidence was a series of interviews with the witness to the crash, who narrowly missed being hit by the aircraft, and a former Rolls-Royce engineer who had examined the engine after the crash.
While the pilot was experienced, he was new to the Halifax with only 13 hours on the type. The rest of the crew were all inexperienced. There were several design flaws with the early Halifax that also contributed to the crash; the fuel valves to the engines were on the wrong side of a fireproof bulkhead, as were the extinguisher bottles. Additionally, the controls to cut off fuel to the engines were placed in a difficult to reach position far behind the cockpit.
But the primary reason for the accident was a change that was made by Rolls-Royce shortly after V9977 entered service. Rolls had noticed that the tappet valves on the engine tended to work loose in service, which was potentially dangerous. In order to keep them in the proper locations, they had begun to install the valves with slightly less clearance in order that they would reach the proper location in service. This was easily accomplished in the factory, but for existing engines the lock nuts holding the valves in place had to be removed, 48 on each engine, the valve adjusted, and the nuts re-tightened.
This procedure was applied to V9977 shortly before its fatal flight. One of the nuts on the engine had not been properly tightened and came loose in flight. The valve began to work its way loose and eventually broke off. This allowed the fuel-air mixture entering the engine to flow into the area under the rocker cover and catch on fire. Although the engine failed, the propeller kept it rotating, operating the fuel pumps and continuing to spray new fuel into the fire.
The fire eventually worked its way back through the fuel lines and into the main fuel tanks. The flight engineer had to cut off the fuel supply using the controls in the fuselage, but never made it. The fire apparently broke out at an altitude of 15,000 feet, more than enough to bail out, but no one left the aircraft. It is suggested that the crew had parachutes but the observers did not, so they decided to remain with the aircraft and perform a forced landing. They almost made it; the aircraft did not break up until about 350 feet.
Sleigh sent a copy of his investigation to Lovell in September 1985, who included passages in his 1991 book, Echos of War.
Memorials
The site today is a few metres north of Herefordshire-Gloucestershire boundary, north of the B4234; the Wye Valley Walk passes close by.
A memorial was built next to the site, with a memorial service on 10 June 2019; the memorial was mostly due to an employee of the Hereford Times, with help from the EMI Archive Trust.
Victims
Seven RAF personnel were killed plus Alan Blumlein and three other radar scientists.
See also
1942 in the United Kingdom
List of accidents and incidents involving military aircraft (1940–1942)
Francis Jones (physicist) and Alec Reeves, who developed OBOE
References
Citations
Bibliography
External links
Accident report
Herefordshire TRE Halifax crash
Herefordshire TRE Halifax crash
Herefordshire TRE Halifax crash
Herefordshire TRE Halifax crash
Herefordshire TRE Halifax crash
Accidents and incidents involving Royal Air Force aircraft
Herefordshire TRE Halifax crash
Aviation accidents and incidents in England
History of electronic engineering
History of telecommunications in the United Kingdom
Military history of Herefordshire
Radar pioneers
River Wye
Science and technology in Herefordshire
Telecommunications in World War II
World War II British electronics | 1942 Herefordshire TRE Halifax crash | [
"Engineering"
] | 1,838 | [
"Electronic engineering",
"History of electronic engineering"
] |
63,236,535 | https://en.wikipedia.org/wiki/Accelerator%20neutrino | An accelerator neutrino is a human-generated neutrino or antineutrino obtained using particle accelerators, in which beam of protons is accelerated and collided with a fixed target, producing mesons (mainly pions) which then decay into neutrinos. Depending on the energy of the accelerated protons and whether mesons decay in flight or at rest it is possible to generate neutrinos of a different flavour, energy and angular distribution. Accelerator neutrinos are used to study neutrino interactions and neutrino oscillations taking advantage of high intensity of neutrino beams, as well as a possibility to control and understand their type and kinematic properties to a much greater extent than for neutrinos from other sources.
Muon neutrino beam production
The process of the muon neutrino or muon antineutrino beam production consists of the following steps:
Acceleration of a primary proton beam in a particle accelerator.
Proton beam collision with a fixed target. In such a collision secondary particles, mainly pions and kaons, are produced.
Focusing, by a set of magnetic horns, the secondary particles with a selected charge: positive to produce the muon neutrino beam, negative to produce the muon anti-neutrino beam.
Decay of the secondary particles in flight in a long (of the order of hundreds meters) decay tunnel. Charged pions decay in more than 99.98% into a muon and the corresponding neutrino according to the principle of preserving electric charge and lepton number:
→ + , → +
It is usually intended to have a pure beam, containing only one type of neutrino: either or . Thus, the length of the decay tunnel is optimised to maximise the number of pion decays and simultaneously minimise the number of muon decays, in which undesirable types of neutrinos are produced:
→ + + , → + +
In most of kaon decays the appropriate type of neutrinos (muon neutrinos for positive kaons and muon antineutrinos for negative kaons) are produced:
→ + , → + , (63.56% of decays),
→ + + , → + + , (3.35% of decays),
however, decays into electron (anti)neutrinos, is also a significant fraction:
→ + + , → + + , (5.07% of decays).
Absorption of the remaining hadrons and charged leptons in a beam dump (usually a block of graphite) and in the ground. At the same time neutrinos unimpeded travel farther, close the direction of their parent particles.
Neutrino beam kinematic properties
Neutrinos do not have an electric charge, so they cannot be focused or accelerated using electric and magnetic fields, and thus it is not possible to create a parallel, mono-energetic beam of neutrinos, as is done for charged particles beams in accelerators. To some extent, it is possible to control the direction and energy of neutrinos by properly selecting energy of the primary proton beam and focusing secondary pions and kaons, because the neutrinos take over part of their kinetic energy and move in a direction close to the parent particles.
Off-axis beam
A method that allows to further narrow the energy distribution of the produced neutrinos is the usage of the so-called off-axis beam. The accelerator neutrino beam is a wide beam that has no clear boundaries, because the neutrinos in it do not move in parallel, but have a certain angular distribution. However, the farther from the axis (centre) of the beam, the smaller is the number of neutrinos, but also the distribution of energy changes. The energy spectrum becomes narrower and its maximum shifts towards lower energies. The off-axis angle, and thus the neutrino energy spectrum, can be optimised to maximize neutrino oscillation probability or to select the energy range in which the desired type of neutrino interaction is dominant.
The first experiment in which the off-axis neutrino beam was used was the T2K experiment
Monitored and tagged neutrino beams
A high level of control of neutrinos at the source can be achieved by monitoring the production of charged leptons (positrons, muons) in the decay tunnel of the neutrino beam. Facilities that employ this method are called monitored neutrino beams. If the lepton rate is sufficiently small, modern particle detectors can time-tag the charged lepton produced in the decay tunnel and associate this lepton to the neutrino observed in the neutrino detector. This idea, which dates back to the 1960s, has been developed in the framework of the tagged neutrino beam concept but it has not been demonstrated, yet. Monitored neutrino beams produce neutrinos in a narrow energy range and, therefore, can employ the off-axis technique to predict the neutrino energy by measuring the interaction vertex, that is the distance of the neutrino interaction from the nominal beam axis. An energy resolution in the 10-20% range has been demonstrated in 2021 by the ENUBET Collaboration.
Neutrino beams in physics experiments
Below is the list of muon (anti)neutrino beams used in past or current physics experiments:
CERN Neutrinos to Gran Sasso (CNGS) beam produced by Super Proton Synchrotron at CERN used in OPERA and ICARUS experiments.
Booster Neutrino Beam (BNB) produced by the Booster synchrotron at Fermilab used in SciBooNE, MiniBooNE and MicroBooNE experiments.
Neutrinos at the Main Injector (NuMI) beam produced by the Main Injector synchrotron at Fermilab used in MINOS, MINERνA and NOνA experiments.
K2K neutrino beam produced by a 12 GeV proton synchrotron at KEK in Tsukuba used in K2K experiment.
T2K neutrino beam produced by the Main Ring synchrotron at J-PARC in Tokai used in T2K experiment.
Notes
Further reading
External links
Accelerator neutrinos - Fermilab
Accelerator physics
Neutrinos | Accelerator neutrino | [
"Physics"
] | 1,322 | [
"Applied and interdisciplinary physics",
"Accelerator physics",
"Experimental physics"
] |
63,236,652 | https://en.wikipedia.org/wiki/Kr00k | Kr00k (also written as KrØØk) is a security vulnerability that allows some WPA2 encrypted WiFi traffic to be decrypted. The vulnerability was originally discovered by security company ESET in 2019 and assigned on August 17th, 2019. ESET estimates that this vulnerability affects over a billion devices.
Discovery
Kr00k was discovered by ESET Experimental Research and Detection Team, most prominently ESET security researcher Miloš Čermák.
It was named Kr00k by Robert Lipovský and Štefan Svorenčík. It was discovered when trying variations of the KRACK attack.
Initially found in chips made by Broadcom and Cypress, similar vulnerabilities have been found in other implementations, including those by Qualcomm and MediaTek.
Patches
The vulnerability is known to be patched in:
iOS 13.2 and iPadOS 13.2 - October 28th, 2019
macOS Catalina 10.15.1, Security Update 2019–001, and Security Update 2019-006 - October 29th, 2019
Vulnerable devices
During their research, ESET confirmed over a dozen popular devices were vulnerable.
Cisco has found several of their devices to be vulnerable and are working on patches. They are tracking the issue with advisory id cisco-sa-20200226-wi-fi-info-disclosure.
Known vulnerable devices include:
Amazon Echo 2nd gen
Amazon Kindle 8th gen
Apple iPad mini 2
Apple iPhone 6, 6S, 8, XR
Apple MacBook Air Retina 13-inch 2018
Asus wireless routers (RT-AC1200G+, RT-AC68U), but fixed in firmware Version 3.0.0.4.382.5161220 during March 2020
Google Nexus 5
Google Nexus 6
Google Nexus 6P
Raspberry Pi 3
Samsung Galaxy S4 (GT-I9505)
Samsung Galaxy S8
Xiaomi Redmi 3S
References
Computer security exploits
Hardware bugs
Wi-Fi
Computer-related introductions in 2019
Telecommunications-related introductions in 2019 | Kr00k | [
"Technology"
] | 418 | [
"Wireless networking",
"Wi-Fi",
"Computer security exploits"
] |
63,237,399 | https://en.wikipedia.org/wiki/NGC%20995 | NGC 995 is a lenticular galaxy located in the constellation Andromeda about 178 million light years from the Milky Way. It was discovered by the French astronomer Édouard Stephan on 8 December 1871.
See also
List of NGC objects (1–1000)
References
0995
02118
+07-06-044
Lenticular galaxies
Andromeda (constellation)
010008
Astronomical objects discovered in 1871
Discoveries by Édouard Stephan | NGC 995 | [
"Astronomy"
] | 88 | [
"Andromeda (constellation)",
"Constellations"
] |
63,237,439 | https://en.wikipedia.org/wiki/NGC%20990 | NGC 990 is an elliptical galaxy located in the constellation Aries about 153 million light-years from the Milky Way. It was discovered by the German - British astronomer William Herschel in 1786.
See also
List of NGC objects (1–1000)
References
0990
Discoveries by William Herschel
Elliptical galaxies
Aries (constellation)
009890 | NGC 990 | [
"Astronomy"
] | 71 | [
"Aries (constellation)",
"Constellations"
] |
63,237,563 | https://en.wikipedia.org/wiki/NGC%20810 | NGC 810 is an unbarred elliptical galaxy located in the constellation Cetus, approximately 360 million light-years from the Milky Way. It was discovered by the French astronomer Édouard Stephan in 1871.
NGC 810 is currently in a merger event. It is interacting with the galaxy SDSS J020529.28+131503.5.
See also
List of NGC objects (1–1000)
References
Cetus
Elliptical galaxies
0810
007965
Discoveries by Édouard Stephan
Astronomical objects discovered in 1871 | NGC 810 | [
"Astronomy"
] | 105 | [
"Cetus",
"Constellations"
] |
63,239,548 | https://en.wikipedia.org/wiki/IBM%20ThinkPad%20570 | The IBM ThinkPad 570 is a notebook series from the ThinkPad line by IBM.
Models
Comparison
References
External links
Thinkwiki.de - 570
ThinkPad 570
570
Computer-related introductions in 1999 | IBM ThinkPad 570 | [
"Technology"
] | 41 | [
"Computing stubs",
"Computer hardware stubs"
] |
63,239,716 | https://en.wikipedia.org/wiki/IBM%20ThinkPad%20750 | The IBM ThinkPad 750 is a series of notebook computers from the ThinkPad series manufactured by IBM.
Features
The 750 series included support for Cellular digital packet data. They also included the pop-up keyboard. The RAM could be expanded with an IC DRAM Card that contained ICs from Hitachi.
Models
750
750C
750Cs
750P
750Ce
Comparison
Reception
A review of the 750C by the Los Angeles Times noted the excellent screen and the keyboard that be lifted up. It also noted the high price.
References
External links
Thinkwiki.de - 750
ThinkPad 750
750
Computer-related introductions in 1993 | IBM ThinkPad 750 | [
"Technology"
] | 124 | [
"Computing stubs",
"Computer hardware stubs"
] |
63,241,107 | https://en.wikipedia.org/wiki/Cognitive%20opening | A cognitive opening is a concept in social movement theory defined as a moment in which a catalytic event, sometimes a personal crisis or socioeconomic pressure, makes a person receptive to new ways of thinking because life changes challenge previously accepted beliefs, prompting a re-assessment of world views.
It is described as a potential stage towards radicalization. The catalytic event can be personal, such as a death in the family or a crime, or broader, such as being confronted by discrimination, socioeconomic crisis, or political repression directly as an individual or as a member of a group.
The origin of the concept is credited to Quintan Wiktorowicz's 2005 book, Radical Islam Rising: Muslim Extremism in the West.
References
Cognitive psychology
Social movements | Cognitive opening | [
"Biology"
] | 153 | [
"Behavioural sciences",
"Behavior",
"Cognitive psychology"
] |
68,907,373 | https://en.wikipedia.org/wiki/Impact%20of%20the%20COVID-19%20pandemic%20on%20the%20telehealth%20industry | Before the COVID-19 pandemic, telehealth adoption was gradually increasing. With the outbreak of COVID-19 in early 2020, healthcare professionals reduced in-person visits to minimize exposure. This led to an increase in the use of telemedicine. with a concomitant increase in publications. (The new reference is “Gonzalez JN, Axiotakis LG Jr, Yu VX, Gudis DA, Overdevest JB. Practice of Telehealth in Otolaryngology: A Scoping Review in the Era of COVID-19. Otolaryngol Head Neck Surg. 2022 Mar;166(3):417-424.. doi: 10.1177/01945998211013751. Epub 2021 May 18”). Telehealth has since remained widely utilized in healthcare services.
Growth in the industry
Telehealth companies have witnessed substantial growth in their business operations since the onset of the pandemic, evident in the significant rise in both patient volume and financial prosperity. For instance, within a short span between February and March 2020, telehealth claims at the Blue Cross Blue Shield of Massachusetts escalated by an astounding 3,500%. NYU Langone Health's telehealth platform swiftly expanded by integrating over 1,300 new healthcare providers during the pandemic, highlighting the industry's meteoric surge. The COVID-19 outbreak facilitated an unprecedented reach for telehealth companies.
The burgeoning influx of new clientele has notably propelled companies such as Teladoc, which has successfully capitalized on this burgeoning market potential. Evidently, Teladoc's stock valuation in 2020 soared year to date by an impressive 168%, while the industry's second-largest player, Amwell, went public on September 17, 2020. Collectively, the top 60 virtual health companies experienced a substantial surge in total revenue, elevating from $3 billion in 2019–2020 to $5.5 billion in 2020–2021, marking an impressive 83% increase. This growth has notably attracted significant interest from venture capitalists and other investors seeking to partake in the burgeoning telehealth industry's expansion during the pandemic. Venture capital funding for telehealth companies in the initial quarter of 2020 surged to $788 million, a figure more than threefold compared to the funds raised in the corresponding period of 2019. Additionally, telehealth startups experienced a staggering year-over-year increase of 1,818% in funding during 2020.
Growth in usage rate
In 2020, over 50% of all outpatient care was being delivered completely virtually at its peak during the pandemic. The number of patients using telehealth has grown from 11% in 2019 to around 46% in 2021. Analysts believe that this growth will be somewhat sustained due to the pandemic allowing telehealth to overcome its biggest obstacle, which was its lack of awareness among patients and providers. Millions of patients and providers have now used telehealth to fulfill part of their healthcare needs, and some evidence suggests telehealth contributes to similar outcomes and patient satisfaction. Not only has telehealth become known among the public, but providers have also had extremely positive interactions with these services. 57% of providers view telehealth more favorably than before the pandemic and 64% of providers are more comfortable with using telehealth platforms. Patients from various demographic locations have given positive reviews on telehealth services due to which telehealth/ telemedicine appears to paint a bright future for the industry.
Potential barriers to growth
Lower usage rate
The weekly average of daily telehealth visits has been declining since April 2020. In April, the visits were peaking at around two thousand per week and they have dropped to around five hundred a week in June 2020. Experts believe that the high peaks of telehealth usage during the pandemic will come down even more and that it is unrealistic to believe that this peak in usage will become the new norm.
Cross-state practice
Most states require that the healthcare professional, that is using telehealth, have a form of license to practice in that state regardless of whether they are located in the state. Cross-state practice issues can inhibit the growth of the telehealth market due to it affecting the staff composition at these companies. These companies will have to make sure that they have professionals that are licensed in the states that the patients are from in order to service the patients. This could inhibit the growth of the industry since these companies have to allocate a certain number of workers to be in each region instead of just having certain types of healthcare professionals.
Coverage and reimbursement issues
Medicare, Medicaid, and commercial payers all have a unique set of rules and criteria for coverage and reimbursements for telehealth services. Lawyers believe that these rules and criteria can be inconsistent at times and can be not fully comprehensive. These unique rules and inconsistencies could potentially add another layer of complexity for providers to have to go through in order to get paid for their services.
IT and security issues
Experts believe that telehealth services hinge upon the success of their IT services. These services include software security, software compliance, and data interoperability. Constructing and maintaining these IT services can be expensive and can be hard to fund due to competition. With the growing number of potential patients, these startup companies could require funding to expand their IT services. Without this expansion, these companies could have lower service quality and put at risk the data and privacy of their consumers.
Another IT-related issue involves technicality, where patients or caregivers have problems accessing telehealth services due to various technical challenges. During the COVID-19 pandemic, one study found that 36% of cancellations or rescheduling of appointments was due to technical challenges before or during the appointment.
Provider-patient relationships
States require that patients and healthcare professionals to establish a relationship. This relationship was normally established when the patient met the provider in-person. This requirement has evolved in some states to focus more on the existence of several factors such as the patient's medical history or the provider's affirmative acts.
Requirements for in-person examinations
A major limitation to telemedicine is the absence of in-person examinations. Complaints requiring urgent assessments will require immediate office visits. Postponements, however, may safely be delayed in most circumstances.
The new reference for all three of these statements is “Strohl MP, Dwyer CD, Ma Y, Rosen CA, Schneider SL, Young VN. Implementation of Telemedicine in a Laryngology Practice During the COVID-19 Pandemic: Lessons Learned, Experiences Shared. J Voice. 2022 May;36(3):396-402. doi: 10.1016/j.jvoice.2020.06.017. Epub 2020 Jun 23.
Remote prescribing
Some states require that an in-person examination happen before allowing for the remote prescribing of drugs. Other states allow remote prescribing without an in-person visit, however there needs to be an interaction via a face-to-face video call. All states do not allow for remote prescribing of drugs if the patient only submitted an online questionnaire.
Telemental health
Due to lockdowns or ‘stay at home’ orders, at the start of the COVID-19 pandemic, mental health services in high-income countries were able to adapt existing service provision to telemental health care. Estimates suggest that between 48% and 100% of service users who were already receiving care at the start of the pandemic were able to continue their mental health care using remote methods. Some face-to-face appointments still took place if necessary.
During the pandemic telemental health care (mostly phone and video calls) was effective and viewed as acceptable by the majority of clinicians and service users for use in an emergency situation. However both groups had concerns regarding the longer term use of telemental health care. For example, clinicians identified concerns including difficulties with medication appointments, concerns around engaging and assessing new patients, and finding it harder to assess some physical indicators of mental health status remotely. Service users identified barriers including a lack of private space at home to access during their sessions or access to technology.
The rates of telemental health use seem to have declined as COVID-19 restrictions were loosened, indicating that face-to-face care might be preferable for some service users and clinicians.
Future opportunities
Lower cost to patients and healthcare facilities
Telehealth often results in significantly lower costs and time commitments than traditional in-person meetings. At the University of Michigan, a study found that on average patients travel a total of 110 miles to attend a clinic visit. Many patients are forced to make a day out of this large time commitment and are forced to take time off work and incur child care costs. By using telehealth, patients can meet with their doctors from anywhere without the need to take time off of work. Telehealth can provide cost savings to hospitals and healthcare offices. Since some portion of patients would be meeting online with their doctors, the need for large waiting rooms would be reduced. This will allow healthcare facilities to be smaller which will result in cost savings due to less overhead being spent on rooms and facilities for patients that do not need to be seen in person.
Substance abuse treatment
In July 2021, telehealth made up 30% of substance abuse treatment. Experts believe that there could be substantial growth potential in substance abuse treatment for the telehealth industry. Telehealth is convenient for patients and makes it easy for them to get the help that they need. Telehealth has also been linked to higher treatment retention. Studies have found that when telehealth video conferencing was incorporated into outpatient treatment programs, 88% of the patients kept their appointments as compared to only 77% that had solely in-person appointments. Due to these benefits there is a potential for telehealth to increase their market share of the substance abuse segment of healthcare.
Tele rheumatology
In February 2021, 17% of outpatient and office visit claims relating to rheumatology were done through telehealth. Clinicians believe that telehealth could play a role in the treatment of rheumatoid arthritis and other symptoms associated with arthritis. Even though clinicians believe that telehealth does not improve diagnosing rheumatologic conditions, they believe that telehealth can help with managing the pain of rheumatoid arthritis. Clinicians consider gout, rheumatoid arthritis, fibromyalgia, and osteoarthritis as the most appropriate to manage using telehealth. Although clinicians believe that the use of tele rheumatology is dependent on the phase of care, they believe that it is vital to increasing the access of care for patients with arthritis.
Present/future usage rate
As of July 2021, telehealth usage has stabilized at a level 38 times higher than before the pandemic. Telehealth usage rate across all specialties has stabilized to around 13% to 17%. While the usage rate has gone down since its peak during the pandemic, experts believe that telehealth will still play a major role in healthcare. Experts predict that at least 20-30% of all healthcare will be provided through telehealth in 2021 and beyond.
Future market size
Analysts are predicting a high amount of growth in the telehealth industry in the United States and globally. In the United States, there are predictions that around $250 billion of Medicare, Medicaid, and Commercial OP could become virtualized, which would represent 20% of the total market share. Research analysts believe that the global market size of the telehealth industry will grow from $62.45 billion in 2020 to over $475.50 billion by 2026.
References
Telehealth
2020 in health
Impact of the COVID-19 pandemic on science and technology
2021 in health
Impact of the COVID-19 pandemic on other health issues | Impact of the COVID-19 pandemic on the telehealth industry | [
"Technology"
] | 2,553 | [
"History of science and technology",
"Impact of the COVID-19 pandemic on science and technology"
] |
68,909,566 | https://en.wikipedia.org/wiki/List%20of%20organisms%20named%20after%20famous%20people%20%28born%201900%E2%80%931949%29 | In biological nomenclature, organisms often receive scientific names that honor a person. A taxon (e.g., species or genus; plural: taxa) named in honor of another entity is an eponymous taxon, and names specifically honoring a person or persons are known as patronyms. Scientific names are generally formally published in peer-reviewed journal articles or larger monographs along with descriptions of the named taxa and ways to distinguish them from other taxa. Following rules of Latin grammar, species or subspecies names derived from a man's name often end in -i or -ii if named for an individual, and -orum if named for a group of men or mixed-sex group, such as a family. Similarly, those named for a woman often end in -ae, or -arum for two or more women.
This list is part of the List of organisms named after famous people, and includes organisms named after famous individuals born between 1 January 1900 and 31 December 1949. It also includes ensembles (including bands and comedy troupes) in which at least one member was born within those dates; but excludes companies, institutions, ethnic groups or nationalities, and populated places. It does not include organisms named for fictional entities, for biologists, paleontologists or other natural scientists, nor for associates or family members of researchers who are not otherwise notable; exceptions are made, however, for natural scientists who are much more famous for other aspects of their lives, such as, for example, Japanese emperors Hirohito and Akihito.
Sir David Attenborough was formerly included in this section of the list as one of these exceptions, since despite his formal training as a natural scientist, he is more widely known to the public as a documentary filmmaker. However, due to the high number of taxa named after him (over 50 as of 2022), he has been removed; his patronyms can be found in the List of things named after David Attenborough and his works.
Organisms named after famous people born earlier than 1900 can be found in:
List of organisms named after famous people (born before 1800)
List of organisms named after famous people (born 1800–1899)
Organisms named after famous people born later than 1949 can be found in:
List of organisms named after famous people (born 1950–present)
The scientific names are given as originally described (their basionyms): subsequent research may have placed species in different genera, or rendered them taxonomic synonyms of previously described taxa. Some of these names are unavailable in the zoological sense or illegitimate in the botanical sense due to senior homonyms already having the same name.
List (people born 1900–1949)
See also
List of bacterial genera named after personal names
List of rose cultivars named after people
List of taxa named by anagrams
List of organisms named after the Harry Potter series
Notes
References
Named after celebrities 1900
Taxonomy (biology)
Organisms 1900
Organisms 1900
Organisms 1900
Taxonomic lists | List of organisms named after famous people (born 1900–1949) | [
"Biology"
] | 595 | [
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists"
] |
68,909,966 | https://en.wikipedia.org/wiki/Elizabeth%20Kujawinski | Elizabeth Kujawinski is an American oceanographer who is Senior Scientist at the Woods Hole Oceanographic Institution, where she works as Program Director of the Center for Chemical Currencies of a Microbial Planet. Her research considers analytical chemistry, chemical oceanography, microbiology and microbial ecology. She is interested in what controls the composition of organic materials in aquatic systems.
Early life and education
Kujawinski was an undergraduate student at Massachusetts Institute of Technology (MIT). She was awarded the undergraduate teaching award from the Department of Chemistry. She moved to the Woods Hole Oceanographic Institution (WHOI) as a doctoral researcher, where she worked in chemical oceanography. Her doctoral research considered the effect of protozoan grazers on polychlorinated biphenyl cycling. After graduating Kujawinski joined the Ohio State University as a postdoctoral scholar.
Research and career
Kujawinski joined the faculty at Barnard College in 2002, and held an adjunct position at Columbia University. She spent two years at Barnard College before being awarded a National Science Foundation CAREER Award and returning to the Woods Hole Oceanographic Institution.
In an effort to understand how cellular metabolism impacts biogeochemical cycles, Kujawinski studies intra- and extracellular metabolic profiles. This information allows Kujawinski to identify which factors influence microbial interactions and the transformation of dissolved organic matter. Marine organic matter comprises carbon compounds that contain heteroatoms such as oxygen, nitrogen and sulphur. She makes use of high-resolution mass spectrometry and automated high through-put methods to analyze the low molecular waste organic materials in seawater. The majority of this organic matter is found deep within the ocean, where it serves as an energy source for microorganisms. Kujawinski is interested in the interplay between marine organisms releasing organic matter and organic matter serving as a food source for microorganisms. For example, Kujawinski identified that dihydrocypropanesulfonate and N-Acetyltaurine are released into the ocean by Phytoplankton and later removed by bacteria. She works alongside the Bermuda Institute of Ocean Sciences to establish which chemical compounds are produced by microorganisms. She is also interested in how these microorganisms evolve and how they interact via zooplankton and viruses.
Kujawinski worked on the Deepwater Horizon oil spill. During the ten years after the spill, Kujawinski analyzed what had been learnt in the time following the disaster. She found that the oil spill had helped scientists learn how bacteria are degrading fossil fuels released within the ocean, how the sun catalyzes the breakdown of crude oil, the impact of dispersants and how different parts of the ecosystem recovered.
Kujawinski was appointed Director of the National Science Foundation Center for Chemical Currencies of a Microbial Planet in 2021. The Center looks to understand the behaviour of bioreactive molecules and ocean microbes.
Selected publications
See also
Outline of oceanography
References
Living people
American oceanographers
American women oceanographers
Massachusetts Institute of Technology alumni
Barnard College faculty
Columbia University faculty
Year of birth missing (living people)
21st-century American scientists
21st-century American earth scientists
21st-century American women scientists
Chemical oceanography | Elizabeth Kujawinski | [
"Chemistry"
] | 668 | [
"Chemical oceanography"
] |
68,912,680 | https://en.wikipedia.org/wiki/BF%20Orionis | BF Orionis is a young Herbig Ae/Be star in the constellation of Orion about away, within the Orion Nebula. It is the most massive star of the small birth cluster of four stars.
Properties
BF Orionis is a Herbig Ae/Be star variable similar to UX Orionis. It is still accreting mass, producing about 2 through the release of gravitational energy, and is surrounded by a massive, optically thick protoplanetary disk of 0.005 visible nearly edge-on. The brightness of the star is strongly variable, with irregular deep minima down to 13th magnitude. The variations are suspected to be partly caused by a brown dwarf or massive planet embedded in the protoplanetary disk, together with very large comets.
Unlike typical Herbig Ae/Be stars, 90-95% of which do not have detectable magnetic fields, BF Orionis has a fairly strong longitudinal magnetic field of −144 gauss. It also has small (0.11 magnitude) short-period, single-mode pulsations of the Delta Scuti type.
References
Herbig Ae/Be stars
Circumstellar disks
Orion (constellation)
J05371326-0635005
026403
Orionis, BF
Delta Scuti variables
Algol variables
A-type bright giants
A-type giants | BF Orionis | [
"Astronomy"
] | 272 | [
"Constellations",
"Orion (constellation)"
] |
68,913,516 | https://en.wikipedia.org/wiki/Cosworth%20GPV8 | The GPV8 is a 3.5-litre and 3.8-litre, naturally-aspirated V8 engine, originally designed, developed and produced by Cosworth, for the Lotus T125 open-wheel sports car. The initial 3.5-litre V8 produced at 9800 rpm, and at 7600 rpm. The rev limit of the engine is 10,300 rpm; and can be temporarily raised to 10,800 rpm with a push-to-pass button feature. The enlarged 3.8-litre V8 is more powerful, producing at 9600 rpm, and at 7600 rpm, with a redline of 10,000 rpm. The engine's power density is between and per litre.
Unlike formula cars, the engine has been manufactured for durability, longevity, and reliability, with the engine able to withstand more than
on premium 98-octane pump gas.
Applications
Lotus T125
References
External links
FZED
Gasoline engines by model
Engines by model
Cosworth
V8 engines | Cosworth GPV8 | [
"Technology"
] | 205 | [
"Engines",
"Engines by model"
] |
68,913,529 | https://en.wikipedia.org/wiki/Jean-Michel%20Basquiat%20%28Warhol%29 | Jean-Michel Basquiat is a painting created by American artist Andy Warhol in 1982. Warhol made multiple silkscreen portraits of artist Jean-Michel Basquiat using his "piss paintings."
History
In 1979, Jean-Michel Basquiat approached Warhol in a restaurant and sold him a postcard. Basquiat later went to Warhol's Factory and sold him some of the painted sweatshirts he was selling. "I just wanted to meet him, he was an art hero of mine," Basquiat recalled.
By 1982, Basquiat made the transition from graffiti artist to one of the leading figures in the Neo-expressionism movement. Bruno Bischofberger became Basquiat's art dealer and gave him a one-man show at his Zurich gallery in September 1982. Bischofberger also represented Warhol and arranged a lunch meeting between the two artists on October 4, 1982. Warhol documented the meeting in a diary entry, which was posthumously published in The Andy Warhol Diaries (1989):Down to meet Bruno Bischofberger (cab $7.50). He brought Jean-Michel Basquiat with him. He's the kid who used the name "Samo" when he used to sit on the sidewalk in Greenwich Village and paint T-shirts, and I'd give him $10 here and there…He's just one of those kids who drove me crazy. He's black but some people say he's Puerto Rican so I don't know. And then Bruno discovered him and now he’s on Easy Street. He's got a great loft on Christie Street. He was a middle-class Brooklyn kid—I mean, he went to college and things—and he was trying to be like that, painting in the Greenwich Village. And so had lunch for them and then I took a Polaroid and he went home and within two hours a painting was back, still wet, of him and me together. And I mean, just getting to Christie Street must have taken an hour. He told me his assistant painted it.This meeting established a friendship between them, "Warhol the established master of Pop Art, and Basquiat, the brash wunderkind of the New York art scene. Basquiat created the painting Dos Cabezas (1982) based on one of the Polaroids Warhol took of them, and Warhol created multiple portraits of Basquiat from a Polaroid he took of him. One portrait is part of the permanent collection of The Andy Warhol Museum in Pittsburgh.American businessman Peter Brant, a major collector of both Warhol and Basquiat, owned one of the portraits. In November 2021, Brant sold his portrait at Christie's 20th Century Evening Sale for $40 million.
Technique
Jean-Michel Basquiat was created using a complex tracing and silkscreening process, using layers of colors of silkscreen ink on top of a background of acrylic polymer paint, applied to a 40-by-40-inch canvas. It is also one of Warhol's "piss paintings," meaning the colors were oxidized by evaporating urine.
Warhol began experimenting with urine in the early 1960s, and in 1978 he "developed the piss-painting technique as a way of introducing a random element—an ironic paraphrase of the hero of Abstract Expressionism, Jackson Pollock, with his drip technique."
Warhol coated the canvas with copper paint and either he or an assistant urinated directly onto the canvas. Warhol wrote in his diary that he preferred the "contributions" of his assistant Ronnie Cutrone "because he takes a lot of vitamin B so the canvas turns a really pretty color when it’s his piss."
References
1982 paintings
Paintings by Andy Warhol
Jean-Michel Basquiat
Paintings of African-Americans
Cultural depictions of American people
Portraits of men
20th-century portraits
Portraits by American artists
Urine | Jean-Michel Basquiat (Warhol) | [
"Biology"
] | 810 | [
"Urine",
"Excretion",
"Animal waste products"
] |
68,915,325 | https://en.wikipedia.org/wiki/BlimE%21 | BlimE! (Stylization of "bli med!", Norwegian for "join in!") is a friendship campaign hosted by the Norwegian Broadcasting Corporation with the slogan "Say hello! Be a friend! Join in". The primary purpose is to inspire children to see each other, care for each other and include each other.
The campaign consists of a song and a corresponding dance that is performed simultaneously by approximately 400,000 children every year. Although the actual effect of the campaign is debated, it is generally agreed that it does support a sense of community by providing common experiences among children.
In 2018, BlimE Day was Friday 21 September. The song was "BlimE" by Freddy Kalas. The following year, BlimE day was Friday 6 September, with the song "Mer enn god nok" by Stina Talling. The army participated with a dance video of its own that received a lot of attention on the internet and in the media and the 2019 edition was named the editorial event of the year during the media awards 2019 under the auspices of the Media Companies National Association.
It was introduced in 2010, and has since then been an annual event. In 2020, It was extended to an international event named #SayHi , hosted by broadcasters from 13 different countries.
In 2021, the campaign was supplemented with cross-disciplinary learning resources for primary schools focusing on ethical dilemmas and social competences.
References
External links
Homepage at NRK
Learning resource page at NRK
Dance events
Friendship
Kindness | BlimE! | [
"Biology"
] | 311 | [
"Behavior",
"Human behavior",
"Kindness"
] |
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