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69,312,633 | https://en.wikipedia.org/wiki/Genome%20mining | Genome mining describes the exploitation of genomic information for the discovery of biosynthetic pathways of natural products and their possible interactions. It depends on computational technology and bioinformatics tools. The mining process relies on a huge amount of data (represented by DNA sequences and annotations) accessible in genomic databases. By applying data mining algorithms, the data can be used to generate new knowledge in several areas of medicinal chemistry, such as discovering novel natural products.
History
In the mid- to late 1980s, researchers have increasingly focused on genetic studies with the advancing sequencing technologies. The GenBank database was established in 1982 for the collection, management, storage, and distribution of DNA sequence data due to the increasing availability of DNA sequences. With the increasing number of genetic data, biotechnological companies have been able to use human DNA sequence to develop protein and antibody drugs through genome mining since 1992. In the late 1990s, many companies, such as Amgen, Immunec, Genentech were able to develop drugs that progressed to the clinical stage by adopting genome mining. Since the Human Genome Project was completed in the early 2000, researchers have been sequencing the genomes of many microorganisms. Subsequently, many of these genomes have been carefully studied to identify new genes and biosynthetic pathways.
Algorithms
As large quantities of genomic sequence data began to accumulate in public databases, genetic algorithms became important to decipher the enormous collection of genomic data. They are commonly used to generate high-quality solutions to optimization and search problems by relying on bio-inspired operators such as mutation, crossover and selection. The followings are commonly used genetic algorithms:
AntiSMASH (Antibiotics and Secondary Metabolite Analysis Shell) addresses secondary metabolite genome pipelines.
PRISM (Prediction Informatics for Secondary Metabolites) is a combinatorial approach to chemical structure prediction for genetically encoded nonribosomal peptides and type I and II polyketides.
SIM (Statistically based sequence similarity) method, such as FASTA or PSI-BLAST, infer orthologous homology.
BLAST (Basic local alignment search tool) is an approach for rapid sequence comparison.
Applications
Genome mining applies on the discovery of natural product by facilitating the characterization of novel molecules and biosynthetic pathways.
Natural product discovery
The production of natural products is regulated by the biosynthetic gene clusters (BGCs) encoded in the microorganism. By adopting genome mining, the BGCs that produce the target natural product can be predicted. Some important enzymes responsible for the formation of natural products are polyketide synthases (PKS), non-ribosomal peptide synthases (NRPS), ribosomally and post-translationally modified peptides (RiPPs), and terpenoids, and many more. Mining for enzymes, researchers can figure out the classes that BGCs encode and compare target gene clusters to known gene clusters. To verify the relation between the BGCs and natural products, the target BGCs can be expressed by suitable host through the use of molecular cloning.
Databases and tools
Genetic data has been accumulated in databases. Researchers are able to utilize algorithms to decipher the data accessible from databases for the discovery of new processes, targets, and products. The following are databases and tools:
GenBank database provides genomic datasets for analysis.
UCSC Genome Browser
AntiSMASH-DB allows comparing the sequences of newly sequenced BGCs against those of previously predicted and experimentally characterized ones.
BIG-FAM is a biosynthetic gene cluster family database.
DoBISCUIT is a database of secondary metabolite biosynthetic gene clusters.
MIBiG (Minimum Information about a Biosynthetic Gene cluster specification) provides a standard for annotations and metadata on biosynthetic gene clusters and their molecular products.
Interactive tree of life (iTOL) is a web-based tool for the display, manipulation and annotation of phylogenetic trees.
References
Medicinal chemistry
DNA
Mining | Genome mining | [
"Chemistry",
"Biology"
] | 826 | [
"Biochemistry",
"nan",
"Medicinal chemistry"
] |
69,313,038 | https://en.wikipedia.org/wiki/Lenovo%20ThinkPad%20X220 | The Lenovo ThinkPad X220 is a laptop computer from the ThinkPad series that was manufactured by Lenovo.
It uses a 12.5 inch IPS or TN display.
A tablet version was also released.
Modifications
The keyboard from the X220 has been retrofitted in a X230.
References
External links
Arch Linux wiki - X220
Thinkwiki.de - X220
McDonnellTech ThinkPad X220 Resources
Lenovo laptops | Lenovo ThinkPad X220 | [
"Technology"
] | 97 | [
"Computing stubs"
] |
69,313,236 | https://en.wikipedia.org/wiki/State%20violence | State violence is the use of force, intimidation, or oppression by a government or ruling body against the citizens within the jurisdiction of said state. This can be seen in a variety of forms, including military violence, settler colonialism, surveillance, immigration law, and other tactics used to express authority over a certain group. State violence can happen through law enforcement or military force, as well as through other branches of government and bureaucracy. State violence is typically justified under the pretense of maintaining law and order, or protecting borders. State violence can include prolonged conditions imposed on individuals that are upheld, unaddressed, or furthered by the state. For example, structural violence that lead to Flint, Michigan having lead-contaminated water may be considered state violence. U.S immigration laws are an additional example of structural violence.
Immigration policy
The effects of US immigration enforcement policies create difficulties for transnational families. The immigration policies also create a state of anxiety within immigrant communities. Individuals with familial ties and long-term residency in the US are forced to leave the country. Additionally, immigration policing policies are intended to capture criminals, yet they do not always target serious offenders. Many immigrants are arrested without warrants by local police, often due to status violations or minor traffic violations. Harm caused by immigration policies necessarily includes involvement of the state. The nature of the states involvement in structural violence is being critically evaluated.
Violence through policy
The passing of the Patriot Act (2001) and the subsequent formation of the Department of Homeland Security expanded the definition (status) of individuals deemed worthy for detention. Policymakers enact laws that reduce individuals to a status. The fear of family separation due to legal status causes ongoing stress for undocumented people, regardless of how long they have lived with their families.
Judicial violence and policing
The involvement of the state in law enforcement is frequently linked to the perpetration of violent behaviors, both on a systemic and personal level. Instances of such behaviors can range from the application of police force by officers, to extended periods of pretrial detention, excessively long prison sentences, and insufficient care provided to those who are incarcerated. These concerns tend to have a greater impact on communities of color. The policies implemented by law enforcement agencies, and the resulting imprisonment, can have a significant impact on various aspects of one's life
Mass incarceration
The United States' high rate of imprisonment represents a form of structural violence that disproportionately affects black Americans. Approximately 33% of black men in the U.S. have felony convictions which leads to disenfranchisement from the voting process. The more someone interacts with law enforcement, jail, and prison, the more they tend to believe that their place in society is predetermined. The consequences of continued imprisonment for them and other members of their community shape their views on the social structure.
Excessive use of force
The issue of excessive police violence is being critically examined as a public health concern. The location where excessive police violence occurs plays a significant role in policing. Police officers tend to use excessive force more frequently in low-income neighborhoods that are predominantly inhabited by people of color. Several factors influence the use of force, including gender, social status, and actual or perceived involvement in criminal activity.
Settler colonialism
Unlike colonialism, settler colonialism seeks to claim land that is already occupied by an indigenous group. Typically, settlers will establish settlements, displace the indigenous groups, and initiate governmental control over the region. During the 18th and 19th centuries, the United States advanced their settler colonial project with forced conversion, residential schools, and displacement of various indigenous communities. Residential schools, also referred to as boarding schools, were state funded and typically managed by churches. These schools took a central role in perpetrating state violence against the native population. While indigenous children were in these schools, they were discouraged from participating in their culture and were given Anglo names. The children were also subjected to abuse, exposed to illness, and isolated from their families. These practices were funded by the Indian Civilization Act Fund of March 3, 1819 and the Compulsory Indian Education Act approved by Congress in 1887.
Violence against indigenous women in the United States
Historically, native women's bodies have been destroyed to further the colonial project in the United States. Because of women's ability to reproduce, native women have been killed in an attempt to extinguish indigenous populations. This reproductive state violence is then continued into the 1970's when the state performed forced sterilizations on unknowing indigenous women.
State surveillance
Government surveillance is a tool used by government agencies to protect citizens from potential attacks from terrorists, extremists, or dissidents. Surveillance methods can include monitoring phone calls, video surveillance, or tracking internet usage. Although surveillance was designed to protect national security, it has the potential to perpetuate state violence.
While surveilling as an action is not inherently violent, it can encroach upon citizens' civil liberties and right to privacy. After the terrorist attacks on September 11, 2001, President George W. Bush signed the Patriot Act; this Act allowed for an expansion of surveillance by the government and law enforcement. In 2008, U.S. Congress passed the FISA Amendment Act that gave government agencies, such as the NSA, unfettered access to private communications of foreigners. Section 702 of the FISA Amendment Act allows for government agencies to collect information from private companies like AT&T, Google, and Facebook to target non- U.S. citizens. In some instances, this permission includes communications between a non-citizen and a U.S. citizen. The FBI has been known to use these databases to search for information on U.S. citizens in a process called “backdoor searches”. Although it is unclear who these searches have been used on, they could potentially be used to control populations, target activists, or profile minority groups. The misuse of surveillance to target civilians can amplify existing power imbalances and reinforce state violence.
References
Further reading
Violence
Human rights abuses | State violence | [
"Biology"
] | 1,229 | [
"Behavior",
"Aggression",
"Human behavior",
"Violence"
] |
69,314,196 | https://en.wikipedia.org/wiki/Bunyaviridae%20nonstructural%20S%20proteins | Bunyaviridae nonstructural S proteins (NSs) are synthesized by viral DNA/RNA and do not play a role in the replication or the viral protein coating. The nonstructural S segment (NSs) created by Bunyaviridae virus family, are able to interact with the human immune system, in order to increase their replication in infected cells. Understanding this mechanism can have global health impacts.
Inhibition pathways
Within the Bunyaviridae virus family, specifically phlebovirus genus, there has been multiple pathways of the inhibition of the immune response. NSs proteins are able to interact with interferon (INF) pathways, but the mechanism varies from virus to virus. The NSs protein in different viruses have been shown to differ in amino acid sequence by up to 85%.
Rift Valley Fever Virus (RVFV)
NSs protein is distributed throughout the cytoplasm and nucleus of the RVFV-infected cell. The protein created fiber-like substances within the nucleus. NSs in RVFV to the SAP30 region of DNA in the nucleus of the cell, which is an important promotor region of INF-b. Many other NSs proteins in the Bunyaviridae virus family do not function in this same way.
Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV)
Although the exact target of the SFTSV is unknown, many believe that the virus attacks human hemopoietic cells. It has been shown that upstream molecules of INFs are unchanged in infected cells, such as MAVS, TRAF6 and TRAF3. This suggests that INFs are still being produced, but they have no effect and are undetectable in people's blood serum. The NSs protein in SFTSV has been shown to interfere with TBK1 which is needed in the activation of both IRF and NF-κB pathways.
Uukuniemi virus (UUKV)
UUKV is a non-human pathogen that still creates a NSs protein. The NSs protein has only been shown to weakly interact with the 40s subunit of ribosomes and MAVS.
Arumowot virus (AMTV)
AMTV is another non-human pathogen and its NSs protein is quickly degraded by proteasomes, and therefore doesn't cause infection in humans.
References
Proteins | Bunyaviridae nonstructural S proteins | [
"Chemistry"
] | 490 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
69,314,250 | https://en.wikipedia.org/wiki/Retinomorphic%20sensor | Retinomorphic sensors are a type of event-driven optical sensor which produce a signal in response to changes in light intensity, rather than to light intensity itself. This is in contrast to conventional optical sensors such as charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) based sensors, which output a signal that increases with increasing light intensity. Because they respond to movement only, retinomorphic sensors are hoped to enable faster tracking of moving objects than conventional image sensors, and have potential applications in autonomous vehicles, robotics, and neuromorphic engineering.
Naming and history
The first so-called artificial retina were reported in the late 1980's by Carver Mead and his doctoral students Misha Mahowald, and Tobias Delbrück. These silicon-based sensors were based on small circuits involving differential amplifiers, capacitors, and resistors. The sensors produced a spike and subsequent decay in output voltage in response to a step-change in illumination intensity. This response is analogous to that of animal retinal cells, which in the 1920's were observed to fire more frequently when the intensity of light was changed than when it was constant. The name silicon retina has hence been used to describe these sensors.
The term retinomorphic was first used in a conference paper by Lex Akers in 1990. The term received wider use by Stanford Professor of Engineering Kwabena Boahen, and has since been applied to a wide range of event-driven sensing strategies. The word is analogous to neuromorphic, which is applied to hardware elements (such as processors) designed to replicate the way the brain processes information.
Operating principles
There are several retinomorphic sensor designs which yield a similar response. The first designs employed a differential amplifier which compared the input signal from of a conventional sensor (e.g. a phototransistor) to a filtered version of the output, resulting in a gradual decay if the input was constant. Since the 1980's these sensors have evolved into much more complex and robust circuits.
A more compact design of retinomorphic sensor consists of just a photosensitive capacitor and a resistor in series. The output voltage of these retinomorphic sensors, , is defined as voltage dropped across the resistor. The photosensitive capacitor is designed to have a capacitance which is a function of incident light intensity. If a constant voltage , is applied across this RC circuit it will act as a passive high-pass filter and all voltage will be dropped across the capacitor (i.e. ). After a sufficient amount of time, the plates of the capacitor will be fully charged with a charge on each plate, where is the capacitance in the dark. Since under constant illumination, this can be simplified to .
If light is then applied to the capacitor it will change capacitance to a new value: . The charge that the plates can accommodate will therefore change to , leaving a surplus / deficit of charge on each plate. The excess charge will be forced to leave the plates, flowing either to ground or the input voltage terminal. The rate of charge flow is determined by the resistance of the resistor , and the capacitance of the capacitor. This charge flow will lead to a non-zero voltage being dropped across the resistor and hence a non-zero . After the charge stops flowing the system returns to steady-state, all the voltage is once again dropped across the capacitor, and again.For a capacitor to change its capacitance under illumination, the dielectric constant of the insulator between the plates, or the effective dimensions of the capacitor, must be illumination-dependent. The effective dimensions can be changed by using a bilayer material between the plates, consisting of an insulator and a semiconductor. Under appropriate illumination conditions the semiconductor will increase its conductivity when exposed to light, emulating the process of moving the plates of the capacitor closer together, and therefore increasing capacitance. For this to be possible, the semiconductor must have a low electrical conductivity in the dark, and have an appropriate band gap to enable charge generation under illumination. The device must also allow optical access to the semiconductor, through a transparent plate (e.g. using a transparent conducting oxide).
Applications
Conventional cameras capture every part of an image, regardless of whether it is relevant to the task. Because every pixel is measured, conventional image sensors are only able to sample the visual field at relatively low frame rates, typically 30 - 240 frames per second. Even in professional high speed cameras used for motion picture, the frame rate is limited to a few 10's of thousands of frames per second for a full resolution image. This limitation could represent a performance bottleneck in the identification of high speed moving objects. This is particularly critical in applications where rapid identification of movement is critical, such as in autonomous vehicles.
By contrast, retinomorphic sensors identify movement by design. This means that they do not have a frame rate and instead are event-driven, responding only when needed. For this reason, retinomorphic sensors are hoped to enable identification of moving objects much more quickly than conventional real-time image analysis strategies. Retinomorphic sensors are therefore hoped to have applications in autonomous vehicles, robotics, and neuromorphic engineering.
Theory
Retinomorphic sensor operation can be quantified using similar techniques to simple RC circuits, the only difference being that capacitance is not constant as a function of time in a retinomorphic sensor. If the input voltage is defined as , the voltage dropped across the resistor as , and the voltage dropped across the capacitor as , we can use Kirchhoff's Voltage Law to state:
Defining the current flowing through the resistor as , we can use Ohm's Law to write:
From the definition of current, we can then write this in terms of charge, , flowing off the bottom plate:
where is time. Charge on the capacitor plates is defined by the product of capacitance, , and the voltage across the capacitor, , we can hence say:
Because capacitance in retinomorphic sensors is a function of time, cannot be taken out of the derivative as a constant. Using the product rule, we get the following general equation of retinomorphic sensor response:
or, in terms of the output voltage:
Response to a step-change in intensity
While the equation above is valid for any form of , it cannot be solved analytically unless the input form of the optical stimulus is known. The simplest form of optical stimulus would be a step function going from zero to some finite optical power density at a time . While real-world applications of retinomorphic sensors are unlikely to be accurately described by such events, it is a useful way to understand and benchmark the performance of retinomorphic sensors. In particular, we are primarily concerned with the maximum height of the immediately after the light has been turned on.
In this case the capacitance could be described by:
The capacitance under illumination will depend on . Semiconductors are known to have a conductance, , which increases with a power-law dependence on incident optical power density: , where is a dimensionless exponent. Since is linearly proportional to charge density, and capacitance is linearly proportional to charges on the plates for a given voltage, the capacitance of a retinomorphic sensor also has a power-law dependence on . The capacitance as a function of time in response to a step function, can therefore be written as:
where is the capacitance prefactor. For a step function we can re-write our differential equation for as a difference equation:
where is the change in voltage dropped across the capacitor as a result of turning on the light, is the change in capacitance as a result of turning on the light, and is the time taken for the light to turn on. The variables and are defined as the voltage dropped across the capacitor and the capacitance, respectively, immediately after the light has been turned on. I.e. is henceforth shorthand for , and is henceforth shorthand for . Assuming the sensor has been held in the dark for sufficiently long before the light is turned on, the change in can hence be written as:
Similarly, the change in can be written as
Putting these into the difference equation for :
Multiplying this out:
Since we are assuming the light turns on very quickly we can approximate . This leads to the following:
Using the relationship , this can then be written in terms of the output voltage:
Where we have defined the peak height as , since he peak occurs immediately after the light has been turned on.
The retinomorphic figure of merit, , is defined as the ratio of the capacitance prefactor and the capacitance of the retinomorphic sensor in the dark:
With this parameter, the inverse ratio of peak height to input voltage can be written as follows:
The value of will depend on the nature of recombination in the semiconductor, but if band-to-band recombination dominates and the charge density of electrons and holes are equal, . For systems where this is approximately true the following simplification to the above equation can be made:
This equation provides a simple method for evaluating the retinomorphic figure of merit from experimental data. This can be carried out by measuring the peak height, , of a retinomorphic sensor in response to a step change in light intensity from 0 to , for a range of values . Plotting as a function of should yield a straight line with a gradient of . This approach assumes that is linearly proportional to .
See also
Active-pixel sensor
Charge coupled device
Event camera
Neuromorphic engineering
Optical sensor
Photodiode
References
Image sensors
Semiconductors
Sensors | Retinomorphic sensor | [
"Physics",
"Chemistry",
"Materials_science",
"Technology",
"Engineering"
] | 2,023 | [
"Electrical resistance and conductance",
"Physical quantities",
"Semiconductors",
"Measuring instruments",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Sensors",
"Solid state engineering",
"Matter"
] |
61,415,748 | https://en.wikipedia.org/wiki/Exhalation%20delivery%20system | Exhalation delivery systems (EDS) deliver medications to the internal nose. Developed in 2006, EDS devices use the patient's exhaled breath to propel medication, such as steroids, into the nasal cavities. The method can deliver medication deeper into the nasal passages than intranasal sprays, and at a lower pressure than nasal irrigation methods.
Using EDS to deliver fluticasone (EDS-FLU) to patients with nasal polyps has been shown to reduce the need for surgery.
References
Respiratory therapy
Drug delivery devices
Dosage forms | Exhalation delivery system | [
"Chemistry"
] | 112 | [
"Pharmacology",
"Drug delivery devices"
] |
61,416,668 | https://en.wikipedia.org/wiki/Structured%20concurrency | Structured concurrency is a programming paradigm aimed at improving the clarity, quality, and development time of a computer program by using a structured approach to concurrent programming.
The core concept is the encapsulation of concurrent threads of execution (here encompassing kernel and userland threads and processes) by way of control flow constructs that have clear entry and exit points and that ensure all spawned threads have completed before exit. Such encapsulation allows errors in concurrent threads to be propagated to the control structure's parent scope and managed by the native error handling mechanisms of each particular computer language. It allows control flow to remain readily evident by the structure of the source code despite the presence of concurrency. To be effective, this model must be applied consistently throughout all levels of the program – otherwise concurrent threads may leak out, become orphaned, or fail to have runtime errors correctly propagated.
Structured concurrency is analogous to structured programming, which uses control flow constructs that encapsulate sequential statements and subroutines.
History
The fork–join model from the 1960s, embodied by multiprocessing tools like OpenMP, is an early example of a system ensuring all threads have completed before exit. However, Smith argues that this model is not true structured concurrency as the programming language is unaware of the joining behavior, and is thus unable to enforce safety.
The concept was formulated in 2016 by Martin Sústrik (a developer of ZeroMQ) with his C library libdill, with goroutines as a starting point. It was further refined in 2017 by Nathaniel J. Smith, who introduced a "nursery pattern" in his Python implementation called Trio. Meanwhile, Roman Elizarov independently came upon the same ideas while developing an experimental coroutine library for the Kotlin language, which later became a standard library.
In 2021, Swift adopted structured concurrency. Later that year, a draft proposal was published to add structured concurrency to Java.
Variations
A major point of variation is how an error in one member of a concurrent thread tree is handled. Simple implementations will merely wait until the children and siblings of the failing thread run to completion before propagating the error to the parent scope. However, that could take an indefinite amount of time. The alternative is to employ a general cancellation mechanism (typically a cooperative scheme allowing program invariants to be honored) to terminate the children and sibling threads in an expedient manner.
See also
Structured programming
References
External links
Notes on structured concurrency, or: Go statement considered harmful by Nathaniel J. Smith
Structured concurrency forum, cross-computer-language discussion of structured concurrency with participation by Sústrik, Smith, and Elizarov
FOSDEM 2019: Structured Concurrency, lightning talk by Martin Sustrik with links to some implementations
Programming paradigms
Concurrent computing | Structured concurrency | [
"Technology"
] | 564 | [
"Computing platforms",
"Concurrent computing",
"IT infrastructure"
] |
61,416,687 | https://en.wikipedia.org/wiki/Suranganie%20Dharmawardhane | Suranganie Dharmawardhane Flanagan is a Sri Lankan molecular biologist and biochemist. She is a professor of biochemistry at the University of Puerto Rico School of Medicine.
Education
In 1980, Dharmawardhane completed a B.S. at University of Colombo. She earned a M.S. at Northeastern University in 1984. She completed a Ph.D. at University of Massachusetts Amherst in 1987. Her dissertation was titled Light-stimulated transplasmalemma electron transport in oat mesophyll cells. She conducted postdoctoral training at Albert Einstein College of Medicine under .
Career
Dharmawardhane researched fibroblasts and leukocytes in the laboratory of at University of California, San Diego. From 1993 to 1997, Dharmawardhane was a senior research associate in the laboratory of in the department of immunology at Scripps Research. She was an assistant professor of molecular, cell, and developmental biology at the University of Texas at Austin (UT Austin) from 1998 to 2005. At UT Austin, Dharmawardhane collaborated with biomedical engineers to develop and design both whole body and microscopic fluorescence image analysis of breast cancer cells in mice. She was an associate professor first in the department of anatomy and cell biology (2005 to 2009) and later in the department of biochemistry (2009 to 2015) at University of Puerto Rico, Medical Sciences Campus (UPR-RCM). In 2015, Dharmawardhane became a tenured full professor and the graduate student coordinator in the department of biochemistry at UPR-RCM. She was an adjunct associate professor in the department of anatomy and cell biology at Universidad Central del Caribe.
Dharmawardhane transferred much of her research program in fluorescence imaging and breast cancer metastasis from UT Austin to University of Puerto Rico. Her laboratory researches breast cancer metastasis and the related molecular mechanisms of signal transaction. She also characterizes pharmacological and natural inhibitors of cancer metastasis. Dharmawardhane has experience with biochemical and molecular analysis of breast cancer cell therapeutics. She conducts much of her research with mouse models.
Dharmawardhane mentors researchers from the undergraduate level to assistant professors. She aims to help mentor women and minorities in biomedical research and academia.
References
External links
Year of birth missing (living people)
Living people
Place of birth missing (living people)
Alumni of the University of Colombo
Northeastern University alumni
University of Massachusetts Amherst alumni
Scripps Research faculty
University of Texas at Austin faculty
University of Puerto Rico faculty
Sri Lankan emigrants to the United States
Sri Lankan expatriate academics
Expatriate academics in the United States
Sri Lankan women scientists
Sri Lankan biochemists
Women molecular biologists
20th-century women scientists
20th-century biologists
20th-century chemists
21st-century women scientists
21st-century biologists
21st-century biochemists
Women biochemists | Suranganie Dharmawardhane | [
"Chemistry"
] | 571 | [
"Biochemists",
"Women biochemists"
] |
61,417,483 | https://en.wikipedia.org/wiki/Antimicrobial%20spectrum | The antimicrobial spectrum of an antibiotic means the range of microorganisms it can kill or inhibit. Antibiotics can be divided into broad-spectrum antibiotics, extended-spectrum antibiotics and narrow-spectrum antibiotics based on their spectrum of activity. Detailedly, broad-spectrum antibiotics can kill or inhibit a wide range of microorganisms; extended-spectrum antibiotic can kill or inhibit Gram positive bacteria and some Gram negative bacteria; narrow-spectrum antibiotic can only kill or inhibit limited species of bacteria.
Currently no antibiotic's spectrum can completely cover all types of microorganisms.
Determination
The antimicrobial spectrum of an antibiotic can be determined by testing its antimicrobial activity against a wide range of microbes in vitro . Nonetheless, the range of microorganisms which an antibiotic can kill or inhibit in vivo may not always be the same as the antimicrobial spectrum based on data collected in vitro.
Significance
Narrow-spectrum antibiotics have low propensity to induce bacterial resistance and are less likely to disrupt the microbiome (normal microflora). On the other hand, indiscriminate use of broad-spectrum antibiotics may not only induce the development of bacterial resistance and promote the emergency of multidrug-resistant organisms, but also cause off-target effects due to dysbiosis. They may also have side effects, such as diarrhea or rash. Generally, a broad antibiotic has more clinical indications, and therefore are more widely used. The Healthcare Infection Control Practices Advisory Committee (HICPAC) recommends the use of narrow-spectrum antibiotics whenever possible.
Examples
Broad-spectrum antibiotic: Ciprofloxacin, Doxycycline, Minocycline, Tetracycline, Imipenem, Azithromycin
Extended-spectrum antibiotic: Ampicillin
Narrow-spectrum antibiotic: Sarecycline, Vancomycin, Isoniazid
See also
Antibiotic
Methicillin-resistant Staphylococcus aureus (MRSA)
References
External links
Healthcare Infection Control Practices Advisory Committee (HICPAC)
Antibiotics
Clinical pharmacology | Antimicrobial spectrum | [
"Chemistry",
"Biology"
] | 444 | [
"Pharmacology",
"Biotechnology products",
"Clinical pharmacology",
"Antibiotics",
"Biocides"
] |
61,417,579 | https://en.wikipedia.org/wiki/Chromium%28II%29%20acetylacetonate | Chromium(II) acetylacetonate is the coordination compound with the formula Cr(O2C5H7)2. It is the homoleptic acetylacetonate complex of chromium(II). It is an air-sensitive, paramagnetic yellow brown solid. According to X-ray crystallography, the Cr center is square planar. In contrast to the triplet ground state for this complex, the bis(pyridine) adduct features noninnocent acac2- ligand attached to Cr(III).
See also
Chromium(III) acetylacetonate
References
Acetylacetonate complexes
Chromium complexes
Chromium–oxygen compounds
Chromium(II) compounds | Chromium(II) acetylacetonate | [
"Chemistry"
] | 160 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
61,417,641 | https://en.wikipedia.org/wiki/Gliese%20357 | GJ 357 (Gliese 357) is an M-type main sequence star with an unusually low star spot activity. It is located 31 light-years from the Solar System, in the Hydra constellation.
Planetary system
The star has three confirmed exoplanets in its orbit. One of these, Gliese 357 d, is considered to be a "super-Earth" within the circumstellar habitable zone.
Planets b and c are close to 3:7 mean-motion resonance. Presuming resonance chain extends to the outermost, cold, super-terrestrial Gliese 357 d and the resonances are simple, GJ 357 might have a more suitable planet for life with an approximate 27.5 day period and almost Earth's flux. Additionally, it might host a Mars-sized planet in 2:1 period ratio with GJ 357 c and 2:3 ratio with hypothetical HZ rocky planet.
References
Planetary systems with three confirmed planets
M-type main-sequence stars
0357
Hydra (constellation)
047103
562 | Gliese 357 | [
"Astronomy"
] | 217 | [
"Hydra (constellation)",
"Constellations"
] |
61,417,653 | https://en.wikipedia.org/wiki/Gliese%20357%20d | Gliese 357 d is an exoplanet, considered to be a "Super-Earth" within the circumstellar habitable zone of its parent star. The planet orbits Gliese 357, 31 light-years from the Solar System, The system is part of the Hydra constellation.
The planet was discovered by the TESS team and announced in July 2019. The data confirming the presence of the planet was uncovered in ground-based observation dating back to 1998 while confirming the TESS detection of Gliese 357 b, a “hot earth” that orbits much closer to the parent star. Even though Gliese 357 d is 20% closer to Gliese 357 than Earth is to the Sun, Gliese 357 is much smaller than the Sun. So it receives as much energy as Mars. As a result, it is estimated that the average temperature is -64°F (-53°C), but this temperature is survivable for humans; if there is a thick enough atmosphere, the actual temperature could be much higher. If humans traveled there using modern spacecraft, it would take them about 660,000 years to get there. The planet is 6.1 times more massive than Earth and 2.3 times Earth's size.
Footnotes
References
Exoplanets detected by radial velocity
Super-Earths
Exoplanets discovered in 2019
Hydra (constellation)
Super-Earths in the habitable zone
Exoplanets discovered by TESS | Gliese 357 d | [
"Astronomy"
] | 299 | [
"Hydra (constellation)",
"Constellations"
] |
61,419,992 | https://en.wikipedia.org/wiki/Eduard%20von%20Feuchtersleben | Eduard Freiherr von Feuchtersleben (30 July 1798 – 13 April 1857 ) was a Kraków-born mining engineer and writer.
Biography
Von Feuchtersleben was born in . His parents were Josephine (1772–1801) and Ernst von Feuchtersleben (1765–1834), an engineer from Hildburghausen. Eduard's half-brother was Baron Ernst von Feuchtersleben, son of Ernst von Feuchtersleben from his second marriage.
Josephine was the daughter of African-born Austrian Angelo Soliman (1721–1796) whose body was secretly claimed after his death by Austrian Emperor Francis II who had Abbé Eberl remove the skin and stuff it for display as an African "savage" in his cabinet of curiosities.
At least since 1817, Eduard von Feuchtersleben wrote small plays, essays and poetry, which were printed since 1822. Since 1832, he was employed as a mining engineer in salt production in Aussee.
Among Eduard's friends were Franz Grillparzer (1791–1872), Eduard von Bauernfeld (1802–90), Nikolaus Lenau (1802–50), and (1794–1859).
By his extensive enthusiasm for poetry in the romantic spirit, he encouraged his half-brother Ernst von Feuchtersleben to also deal with poetry. Eduard and Ernst von Feuchtersleben were deeply attached to each other, and Ernst dedicated some of his texts to the older half-brother. Ernst also campaigned for a complete edition of Eduard's works, but this project was never brought to fruition.
Eduard von Feuchtersleben never married and had no children. He died in in Bad Aussee.
References
1798 births
1857 deaths
Polish male writers
Mining engineers
Writers from Kraków
Eduard
Polish people of African descent | Eduard von Feuchtersleben | [
"Engineering"
] | 374 | [
"Mining engineering",
"Mining engineers"
] |
61,420,230 | https://en.wikipedia.org/wiki/Dorota%20Skowron | Dorota Maria Skowron is a scientist at the University of Warsaw. In 2019 she was part of the team that confirmed that the Milky Way galaxy was not flat. She is a member of the International Astronomical Union.
References
External links
Dorota Skowron's research works | University of Warsaw, Warsaw (UW) and other places
NASA ADS.
astro-ph.
Living people
Year of birth missing (living people)
University of Warsaw alumni
Academic staff of the University of Warsaw
Polish women academics
Polish women scientists
Place of birth missing (living people)
21st-century Polish astronomers
Women astronomers | Dorota Skowron | [
"Astronomy"
] | 122 | [
"Women astronomers",
"Astronomers"
] |
61,421,165 | https://en.wikipedia.org/wiki/Dibling | A dibling, a portmanteau of donor sibling, or donor-conceived sibling, or donor-sperm sibling, is one of two or more individuals who are biologically connected through donated eggs or sperm. This term is also commonly used in children biologically related through embryo donation. In tis instance, the children are full not half biological siblings. The term is not favored among some recipient parents, who prefer the use of half-sibling.
People born from anonymous or ID release sperm or egg donation are able to find half-siblings conceived using the same gamete donor online through the Donor Sibling Registry or by using commercially-available DNA test kits. DNA testing is more accurate because it relies on comparison of single-nucleotide polymorphisms instead of gamete donor identification numbers (which may be erroneous).
References
Fertility medicine
Sperm donation
Kinship and descent
Sibling | Dibling | [
"Biology"
] | 177 | [
"Behavior",
"Human behavior",
"Kinship and descent"
] |
61,421,514 | https://en.wikipedia.org/wiki/Hantz%20reactions | Hantz reactions are a class of pattern-forming precipitation reactions in gels implementing a reaction–diffusion system. The precipitation patterns are forming as a reaction of two electrolytes: a highly concentrated "outer" one diffuses into a hydrogel, while the "inner" one is dissolved in the gel itself. The colloidal precipitate which builds up the patterns is trapped by the gel and kept at the location where it is formed, similar to Liesegang rings.
The first representative of this class of reactions was the NaOH (outer electrolyte)+CuCl2 (inner electrolyte). Later the NaOH+AgNO3, the CuCl2+K3[Fe(CN)6], the NaOH+AlCl3, and the NH3+AgNO3 reactions in several hydrogels have also proved to show similar behavior. Precipitate patterns forming in these reactions are exceptionally rich. Besides the macroscopic shapes like layered structures, helices and cardioids, regular sheets of colloidal precipitate may also emerge with a periodicity even less than 20 micrometers (microscopic patterns).
Macroscopic patterns
The arrangement that best shows the sequence of events leading to the formation of macroscopic patters is the one in which the outer electrolyte penetrates in a thin gel sheet located between two glass plates. In this case, the diffusion front has a quasi-one-dimensional shape. If there are some impurities or obstacles in the gel, the precipitation may cease at these points, and the traveling precipitation front following the diffusion front will split. As the broken precipitation front advances, its active segments are getting shorter, resulting in triangle-like regions free of precipitate behind the front. The reason why the precipitation temporarily or permanently stops in these regions is that the oblique, passive edges of the precipitate act as a semipermeable membrane, blocking the diffusion of the outer electrolyte.
The mechanism behind the regression of the active front segments is not fully understood. It is believed that a diffusive intermediate compound forms at the active segments having reduced concentration at the sides, and a critical concentration is required for the precipitation to occur.
When the outer electrolyte is poured onto the top of a gel column in a glass tube, the diffusion front takes roughly the form of a disk. In this case, the precipitation fronts involved in pattern formation can perform more complicated motions, leading to more complex patterns that depend on the outer and inner electrolyte concentration. These include the formation of multi-armed helices, intermingled cardioids, Voronoi tessellations, so-called target patterns and other, even more complex shapes.
Microscopic patterns
In certain conditions, for example when the cation of the inner electrolyte is Cu2+ or Ag2+, regular sheets consisting of colloidal grains are formed. This phenomenon is especially striking when the reactions run in poly(vinyl)alcohol gels, and the speed of the precipitation front falls below about 0.3 μm/s. The finest microscopic patterns have been observed in the NaOH+AgNO3 reactions, where the periodicity dropped below 10 μm. The chemical mechanism of this pattern formation is not fully understood, but computer simulations based on phase separation described by the Cahn–Hilliard equation with a moving source front exhibit the most important properties of the building of the microscopic patterns. Defects may also be present in the regular microscopic sheets, which can even interact during the front propagation. These microscopic patterns have raised interest in different fields of micro and nanotechnology as well
See also
Diffusion-controlled reaction
Turing pattern
Belousov–Zhabotinsky reaction
References
External links
Liesegang banding
Macroscopic patterns, NaOH+CuCl2
Microscopic patterns, NaOH+CuCl2 and NaOH+AgCl2 in PVA gel
Helical precipitation patterns
Gels
Chemical reactions
Diffusion | Hantz reactions | [
"Physics",
"Chemistry"
] | 809 | [
"Transport phenomena",
"Physical phenomena",
"Diffusion",
"Colloids",
"nan",
"Gels"
] |
61,422,935 | https://en.wikipedia.org/wiki/Chroogomphus%20subfulmineus | Chroogomphus subfulmineus is a basidiomycete fungus in the family Gomphidiaceae, described as new to science in 2018.
This species is closely related to Chroogomphus fulmineus, but produces larger fruit bodies with generally duller colours, a deep yolk-yellow trama and an olivaceous stipe base. Microscopically, it has more narrow cystidia (av. range 13.8–14.8 μm) than C. fulmineus and broader spores (av. range 17.5–21.6 × 6.4–7.7 μm).
It is so far known from the island of Cyprus, Finland, and the United Kingdom.
References
Fungi described in 2018
Boletales
Fungi of Europe
Fungus species | Chroogomphus subfulmineus | [
"Biology"
] | 168 | [
"Fungi",
"Fungus species"
] |
61,423,208 | https://en.wikipedia.org/wiki/C25H40N7O17P3S | {{DISPLAYTITLE:C25H40N7O17P3S}}
The molecular formula C25H40N7O17P3S (molar mass: 835.609 g/mol) may refer to:
Crotonyl-CoA
Methacrylyl-CoA
Molecular formulas | C25H40N7O17P3S | [
"Physics",
"Chemistry"
] | 68 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,424,662 | https://en.wikipedia.org/wiki/Anderson%27s%20theorem%20%28superconductivity%29 | In the field of superconductivity, Anderson's theorem states that superconductivity in a conventional superconductor is robust with respect to (non-magnetic) disorder in the host material. It is named after P. W. Anderson, who discussed this phenomenon in 1959, briefly after BCS theory was introduced.
One consequence of Anderson's theorem is that the critical temperature Tc of a conventional superconductor barely depends on material purity, or more generally on defects. This concept breaks down in the case of very strong disorder, e.g. close to a superconductor-insulator transition. Also, it does not apply to unconventional superconductors. In fact, strong suppression of Tc with increasing defect scattering, thus non-validity of Anderson's theorem, is taken as a strong indication for superconductivity being unconventional.
References
Superconductivity | Anderson's theorem (superconductivity) | [
"Physics",
"Materials_science",
"Engineering"
] | 187 | [
"Physical quantities",
"Superconductivity",
"Materials science",
"Condensed matter physics",
"Electrical resistance and conductance"
] |
61,425,799 | https://en.wikipedia.org/wiki/C19H21N3S | {{DISPLAYTITLE:C19H21N3S}}
The molecular formula C19H21N3S (molar mass: 323.46 g/mol, exact mass: 323.1456 u) may refer to:
Cyamemazine, or cyamepromazine
Metiapine | C19H21N3S | [
"Chemistry"
] | 67 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,426,255 | https://en.wikipedia.org/wiki/C10H24N4 | {{DISPLAYTITLE:C10H24N4}}
The molecular formula C10H24N4 (molar mass: 200.330 g/mol, exact mass: 200.2001 u) may refer to:
Cyclam (1,4,8,11-tetraazacyclotetradecane)
Tetrakis(dimethylamino)ethylene (TDAE) | C10H24N4 | [
"Chemistry"
] | 89 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,426,720 | https://en.wikipedia.org/wiki/Myxomitodes | Myxomitodes (Greek "slime thread like") is a genus of problematic fossil from the Paleoproterozoic (1900 million years old) Stirling Range Formation of Western Australia, and is significant as a very old megascopic fossil, and thus eukaryote. It is a trace fossil and thus evidence of activity, rather than a body fossil.
Description
Myxomitodes stirlingensis are irregular markings on the surface of beds, with the superficial appearance of animal trails. They are problematic for such trails because of their great geological age. Unlike fossil trails made by slugs or worms, Myxomitodes flare and vary in width. Worm and slug trails are long, so generally run off the edges of rock slabs. Myxomitodes in contrast is short, with one end tapering and the other forming a bulbous structure.
Biological affinities
Myxomitodes stirlingensis is a problematic fossil of controversial biological affinities. At first it was interpreted as a trail of a soft-bodied worm-like animal, and then as a trail of wind blown bubbles. Later it was suggested to be a trace of a giant globular, marine amoeba, similar to Gromia. Discovery of a variety of paleosols associated with Myxomitodes suggests that it might have lived on land like dictyostelid slime molds. These are dispersed soil amoebae for most of their life cycle, but occasionally stream together to form a grex, or slug-like multicellular aggregate that moves a short distance to form a sporulating stalk. This explanation explains the flaring shape (from cellular aggregation), levees (from slime trail), short length (migration distance) and bulbous ends (base of sporulating stalk). However, the fossil is older than the oldest currently accepted amoebozoans, bringing this interpretation into doubt.
References
External links
Paleoproterozoic
Fossils of Australia
Controversial taxa
Trace fossils | Myxomitodes | [
"Biology"
] | 413 | [
"Biological hypotheses",
"Controversial taxa"
] |
61,426,879 | https://en.wikipedia.org/wiki/C23H29N3O2 | {{DISPLAYTITLE:C23H29N3O2}}
The molecular formula C23H29N3O2 (molar mass: 379.495 g/mol) may refer to:
Cymserine
Oxypertine
1P-LSD
Molecular formulas | C23H29N3O2 | [
"Physics",
"Chemistry"
] | 61 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,427,045 | https://en.wikipedia.org/wiki/C21H27N5 | {{DISPLAYTITLE:C21H27N5}}
The molecular formula C21H27N5 may refer to:
D75-4590
Mavorixafor | C21H27N5 | [
"Chemistry"
] | 39 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,427,060 | https://en.wikipedia.org/wiki/C23H22FNO4 | {{DISPLAYTITLE:C23H22FNO4}}
The molecular formula C23H22FNO4 may refer to:
ALX-1393
DAA-1106 | C23H22FNO4 | [
"Chemistry"
] | 41 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
63,611,729 | https://en.wikipedia.org/wiki/Spill%20%28book%29 | Spill is a 1991 fictional thriller by Les Standiford about a lethal biological weapon that has leaked from a crashed tanker truck in Yellowstone National Park. Agents of PetroDyne Corporation, the Denver-based chemical company responsible for manufacturing the banned agent, works with its co-conspirators in the government to cover up the incident. A Yellowstone National Park Ranger named Jack Fairchild finds himself in the middle of the coverup and does everything in his power to help his friends escape an assassin named Skanz.
Spill was dramatized in Virus, a 1996 film directed by Allan A. Goldstein and starring Brian Bosworth.
Plot
A lethal biological weapon has leaked from a crashed tanker truck in Yellowstone National Park. PetroDyne Chemical, the company manufacturing the substance banned by international treaty, sends the tanker from its headquarters in Denver to a storage facility in Idaho. The genetically engineered form of hemorrhagic fever has spilled into a waterway and has infected wildlife and humans in a popular camping area in the small town of West Yellowstone, Montana. The driver responsible for the spill has been paid by a rogue employee of the company to divert the shipment to the hills of Yellowstone.
Agents for PetroDyne work with local government officials who are aware of the transport of hazardous chemicals by the company to cover up the incident. The coverup involves finding any survivors of the spill, quarantining them, observing them, and even worse, allowing them to die and incinerating the bodies. The head of PetroDyne Corporation, a man named Schreiber who works at the company headquarters in Denver, directs a loyal employee named Alec Reisman and a half-mad hitman named Skanz to clean up the mess that was created.
Jack Fairchild is the Park Ranger who finds the truck driver who caused the spill, and other survivors, and must overcome all obstacles to free them from the grasp of PetroDyne’s security team.
Reception
The book received reviews from publications including Publishers Weekly, Kirkus Reviews, Library Journal, Chicago Tribune, and Los Angeles Times.
References
1991 American novels
1991 science fiction novels
Action novels
American novels adapted into films
Yellowstone National Park
Novels set in Montana | Spill (book) | [
"Biology"
] | 437 | [
"Biological weapons in popular culture",
"Biological warfare"
] |
63,611,863 | https://en.wikipedia.org/wiki/H3K36me | H3K36me is an epigenetic modification to the DNA packaging protein Histone H3, specifically, the mono-methylation at the 36th lysine residue of the histone H3 protein.
There are diverse modifications at H3K36, such as phosphorylation, methylation, acetylation, and ubiquitylation, which have many important biological processes. The methylation of H3K36 has particularly had effects in transcriptional repression, alternative splicing, dosage compensation, DNA replication and repair, DNA methylation, and the transmission of the memory of gene expression from parents to offspring during development.
Nomenclature
H3K36me2 indicates dimethylation of lysine 36 on histone H3 protein subunit:
Lysine methylation
This diagram shows the progressive methylation of a lysine residue. The mono-methylation (second from left) denotes the methylation present in H3K36me1.
Lysine methylation is the addition of a methyl group to the lysine of histone proteins. This occurs via histone lysine methyltransferase (HMTase) that utilize S-adenosylmethionine to specifically place the methyl group on histone Lys or Arg residues. So far, there have only been eight specific mammalian enzymes discovered that can methylate H3K36 in vitro and/or in vivo, all of which have identical catalytic SET domains but, different preferences for Lys36 residues in different methylation states.
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, which 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 wrapped around it. 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 remodeling complexes is interpreted by the cell and leads to the 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 come 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. The use of ChIP-sequencing revealed regions in the genome characterized by different banding. Different developmental stages were profiled in Drosophila as well, an emphasis was placed on histone modification relevance. A look into the data obtained led to the definition of chromatin states based on histone modifications. Certain modifications were mapped and enrichment was seen to localize in certain genomic regions. Five core histone modifications were found with each respective one being linked to various cell functions.
H3K4me3-promoters
H3K4me1- primed enhancers
H3K36me3-gene bodies
H3K27me3-polycomb repression
H3K9me3-heterochromatin
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.
Methods
The histone mark H3K36me can be detected in a variety of ways:
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.
Micrococcal Nuclease sequencing (MNase-seq) is used to investigate regions that are bound by well-positioned nucleosomes. The use of the micrococcal nuclease enzyme is employed to identify nucleosome positioning. Well-positioned nucleosomes are seen to have enrichment of sequences.
Assay for transposase accessible chromatin sequencing (ATAC-seq) is used to look into regions that are nucleosome-free (open chromatin). It uses hyperactive Tn5 transposon to highlight nucleosome localization.
See also
Histone methylation
Histone methyltransferase
Methyllysine
References
Methylation
Epigenetics
Post-translational modification | H3K36me | [
"Chemistry"
] | 1,171 | [
"Post-translational modification",
"Gene expression",
"Methylation",
"Biochemical reactions"
] |
63,612,550 | https://en.wikipedia.org/wiki/Systems%20Improved%20Numerical%20Differential%20Analyzer | The Systems Improved Numerical Differential Analyzer (acronym SINDA) is a commercially available software system developed by C&R Technologies that solves resistor-capacitor (R-C) network representations of physical problems governed by diffusion equations. The software was originally designed as a general thermal analyzer for the spacecraft and launch vehicle thermal community and is currently an integral part of the Thermal Desktop plugin for AutoCAD.
References
Physics software | Systems Improved Numerical Differential Analyzer | [
"Physics"
] | 89 | [
"Physics software",
"Computational physics stubs",
"Computational physics"
] |
63,612,800 | https://en.wikipedia.org/wiki/Farr%27s%20laws | Farr's law is a law formulated by Dr. William Farr when he made the observation that epidemic events rise and fall in a roughly symmetrical pattern. The time-evolution behavior could be captured by a single mathematical formula that could be approximated by a bell-shaped curve.
Background
In 1840, Farr submitted a letter to the Annual Report of the Registrar General of Births, Deaths and Marriages in England. In that letter, he applied mathematics to the records of deaths during a recent smallpox epidemic, proposing that:
"If the latent cause of epidemics cannot be discovered, the mode in which it operates may be investigated. The laws of its action may be determined by observation, as well as the circumstances in which epidemics arise, or by which they may be controlled."
He showed that during the smallpox epidemic, a plot of the number of deaths per quarter followed a roughly bell-shaped or "normal curve", and that recent epidemics of other diseases had followed a similar pattern.
References
Epidemiology
Statistical algorithms | Farr's laws | [
"Biology",
"Environmental_science"
] | 210 | [
"Virus stubs",
"Viruses",
"Epidemiology",
"Environmental social science"
] |
63,614,556 | https://en.wikipedia.org/wiki/Ethyl%203-bromopropionate | Ethyl 3-bromopropionate is the organobromine compound with the formula BrCH2CH2CO2C2H5. It is a colorless liquid and an alkylating agent. It is prepared by the esterification of 3-bromopropionic acid. Alternatively, it can be prepared by hydrobromination of ethyl acrylate, a reaction that proceeds in an anti-Markovnikov sense.
See also
Ethyl bromoacetate
References
Alkylating agents
Ethyl esters
Propionate esters
Organobromides
Reagents for organic chemistry | Ethyl 3-bromopropionate | [
"Chemistry"
] | 128 | [
"Alkylating agents",
"Reagents for organic chemistry"
] |
63,616,965 | https://en.wikipedia.org/wiki/Kevin%20Insik%20Hahn | Kevin Insik Hahn is a South Korean physicist who is an expert in the fields of nuclear physics and nuclear astrophysics. Since December 2019, he has been the director of the Center for Exotic Nuclear Studies at the Institute for Basic Science (IBS) in South Korea. He also holds an endowed professorship in the Department of Science Education at Ewha Womans University, where he has worked since 1999. In his research, he has worked on accelerator-based as well as non-accelerator-based experiments. His current research activities involve a number of accelerators around the world, including the RI Beam Factory (RIBF) at RIKEN, Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, and the soon-to-open Rare isotope Accelerator complex for ON-line experiment (RAON). During his tenure at Ewha Womans University, he promoted STEM/STEAM education by serving for multiple years as the director of the Advanced STEAM Teacher Education Center. He also wrote several physics textbooks for high school students and undergraduate students.
Education
Hahn obtained a B.S. in physics from University of California, Los Angeles (UCLA) in 1984. He then enrolled in Yale University and graduated with a M.S. in physics in 1989 and a Ph.D. in nuclear astrophysics in 1993. His doctoral thesis was on the reaction rates of 17F(p,γ)18Ne and 14O(α,p)17F and was supervised by Peter Parker.
Career
Hahn went to Caltech and worked for three years as a research fellow in the Kellogg Radiation Laboratory with Ralph Kavanagh. Relocating to Japan, he spent the next two years as a research fellow at RIKEN becoming an official RIKEN Fellow from 1996 to 1997. As a Fellow, he worked with Ishihara at the Radiation Laboratory at RIKEN and also worked closely with Motobayashi and Kubono. The next year he worked as a research professor in the University of Houston teaching an undergraduate course on electromagnetism and conducted hypernuclear experiments at Brookhaven National Laboratory and rare decay experiments. From 1999, he worked as a professor in the Department of Science Education, Ewha Womans University, Korea including as an invited chair professor. From 2014, he has worked as a visiting scholar with RAON and the IBS Center for Underground Physics where he worked with KIMS (dark matter search), AMoRE (double beta decay experiment), and the HPGe Array.
Working mainly on silicon detector for the PHENIX collaboration, he and collaborators found evidence of the quark–gluon plasma, which can be made in small-scale collision systems. Working with colleagues, he participated in experiments confirming atomic nuclei with 34 neutrons are more stable than expected. Earlier experiments theorized this but had been unable to confirm it.
In late 2019, Hahn became the founding director of the IBS Center for Exotic Nuclear Studies. Divided into four groups; experimental nuclear astrophysics, experimental nuclear structure, experimental nuclear reaction and theoretical nuclear physics, research of the center uses rare isotope beams from overseas RI accelerators and later the Rare Isotope Science Project's (RISP) RAON accelerator in Korea, specifically RISP's KOrea Broad acceptance Recoil spectrometer and Apparatus (KOBRA) with a focus on discovering rare isotopes and investigating the origins of heavy elements. His work will help direct collaborations among universities and research groups studying rare isotope accelerator sciences in South Korea.
Awards and honors
2018: Outstanding faculty in research, Ewha Womans University
2017: Outstanding faculty in research, Ewha Womans University
2006: Outstanding faculty in research grant, Ewha Womans University
1996-1997: RIKEN Fellow
1993-current: Member, American Physical Society
Committee work
2019: International Advisory Committee for the 15th Symposium on Origin of Matter and Evolution of Galaxies (OMEG), Kyoto, Japan
2018–present: Board member of the RAON Users Association
2017: International Advisory Committee for the Symposium on Origin of Matter and Evolution of Galaxies (OMEG), Daejeon, Korea
2015-2016: Board member of the Korean Physical Society
2014-2018: Board member of Asian Nuclear Physics Association (ANPhA)
2013–present: Member of the RISP Scientific Program Advisory Committee
Selected publications
References
External links
Research Centers - Center for Exotic Nuclear Studies
Applied Nuclear Physics Lab
South Korean physicists
University of California, Los Angeles alumni
Yale University alumni
Academic staff of Ewha Womans University
California Institute of Technology faculty
Riken personnel
University of Houston alumni
Living people
Nuclear physicists
Institute for Basic Science
1962 births
South Korean scientists | Kevin Insik Hahn | [
"Physics"
] | 937 | [
"Nuclear physicists",
"Nuclear physics"
] |
63,617,960 | https://en.wikipedia.org/wiki/NGC%20538 | NGC 538 is a barred spiral galaxy in the constellation of Cetus. It is located about 250 million light-years from the Milky Way with a diameter of approximately 95,000 ly. NGC 538 was discovered by the American astronomer Lewis Swift in 1886.
NGC 538 is estimated to be about 2.5 billion years old.
See also
List of NGC objects (1–1000)
References
External links
Barred spiral galaxies
Cetus
0538
005275
00991
+00-04-130 | NGC 538 | [
"Astronomy"
] | 104 | [
"Cetus",
"Constellations"
] |
63,617,992 | https://en.wikipedia.org/wiki/NGC%20539 | NGC 539 is a barred spiral galaxy in the constellation of Cetus south. It is estimated to be 429 million light years from the Milky Way and has a diameter of approximately 200,000 ly. It was discovered on 31 October 1885 by American astronomer Francis Leavenworth.
See also
List of NGC objects (1–1000)
References
Barred spiral galaxies
Cetus
0539
005269
Discoveries_by_Francis_Leavenworth
-03-04-063
542-010
01229-1825 | NGC 539 | [
"Astronomy"
] | 108 | [
"Cetus",
"Constellations"
] |
63,618,028 | https://en.wikipedia.org/wiki/NGC%20543 | NGC 543 is an elliptical galaxy located around 324 million light-years away in the constellation Cetus. NGC 543 was discovered on October 31st, 1864 by Heinrich Louis d'Arrest. It is not known to have much star formation, and it is a member of the galaxy cluster Abell 194.
See also
List of NGC objects (1–1000)
References
External links
Elliptical galaxies
0543
Cetus
005311 | NGC 543 | [
"Astronomy"
] | 86 | [
"Cetus",
"Constellations"
] |
63,619,503 | https://en.wikipedia.org/wiki/Distilling%20ship | A distilling ship is a class of military ships, generally converted tankers, with the capability to convert salt water into fresh water. They were typically stationed at forward bases during conflict where they supported on-the-ground troops and front line naval units.
Kleinschmidt still
While steamships often used the heat in low-pressure steam exhausted from propulsion machinery to distill fresh water from seawater, that was relatively inefficient when the ship was not underway. Dr. R.V. Kleinschmidt developed a compression still while working at the Arthur D. Little Laboratories in Cambridge, Massachusetts. These stills were manufactured for the United States Navy by E. B. Badger and Sons of Boston. After these Kleinschmidt stills proved successful aboard diesel engined ships like submarines, destroyer escorts, and tank landing ships, several stills were placed aboard tankers built as distilling ships.
Seawater enters the evaporation chamber through two heat exchangers. The evaporation chamber has an electrical heating element used to initially heat the seawater during startup, and the resulting steam is run through a rotary compressor which increases the steam temperature while creating a vacuum over the seawater in the evaporation chamber to lower the boiling temperature of seawater. The compressed steam is then piped though the evaporation chamber as the primary source of heat so the heating element becomes unnecessary for sustained operation. The compressor maintains a pressure difference of approximately between the boiling seawater and condensing steam which translates to an approximate temperature difference of 5 °C (9 °F) across the tube walls within the evaporation chamber. Steam condensed while evaporating the seawater is removed as fresh water through one of the heat exchangers pre-heating the incoming seawater, and about twenty percent of the incoming seawater leaves the evaporation chamber as hot brine pumped overboard through another heat exchanger.
Operational experience
These ships frequently operated in tropical harbors where seawater contained appreciable quantities of pollutants. Some of these pollutants would be carried through the compressor as mist from the boiling seawater, and the temperature of the distillation process was inadequate to sterilize the fresh water. Some microorganisms carried through to the fresh water were pathogenic, while others colonized the ships' fresh water tanks using nutrients carried through the compressors to cause taste and odor problems making the water unpalatable. Microbial growth was rapid in the warm water of the tropics. The United States Navy crew would include a naval surgeon to test and maintain water quality.
A newly cleaned still would produce about 200 gallons of fresh water per gallon of diesel fuel powering the compressor, but accumulation of scale on the brine side of the steam pipes within the evaporation chamber and seawater heat exchanger would typically reduce efficiency to about 100 gallons of water per gallon of fuel after 700 hours of operation.
See also
References
Ship types
Distilling ships | Distilling ship | [
"Chemistry"
] | 602 | [
"Distilling ships",
"Distillation"
] |
63,619,636 | https://en.wikipedia.org/wiki/Remote%20point | In general topology, a remote point is a point that belongs to the Stone–Čech compactification of a Tychonoff space but that does not belong to the topological closure within of any nowhere dense subset of .
Let be the real line with the standard topology. In 1962, Nathan Fine and Leonard Gillman proved that, assuming the continuum hypothesis:
Their proof works for any Tychonoff space that is separable and not pseudocompact.
Chae and Smith proved that the existence of remote points is independent, in terms of Zermelo–Fraenkel set theory, of the continuum hypothesis for a class of topological spaces that includes metric spaces. Several other mathematical theorems have been proved concerning remote points.
References
General topology | Remote point | [
"Mathematics"
] | 149 | [
"General topology",
"Topology",
"Topology stubs"
] |
63,621,022 | https://en.wikipedia.org/wiki/Persulfidation | Persulfidation (also called sulfhydration) is a type of post-translational modification of proteins involving addition of a sulfur molecule onto a reactive thiol (-SH) group of a cysteine residue. Persulfidation occurs in plants, animals, and throughout all kingdoms. It is a redox mechanism that regulates diverse biological processes in hydrogen sulfide (H2S) signaling by regulating protein functions and/or subcellular localizations.
The added sulfur atom (or atoms) are in a chain (R-S-SH, R-S-S-SH. These sulfur chains are unstable and react readily, making identification and quantification difficult.
This modification can be reversed back into a thiol by exogenous chemical reducing agents such as dithiothreitol (DTT) or TCEP, biological reducing agents such as glutathione, and proteins such as thioredoxin or glutaredoxin.
References
Sulfur
Post-translational modification | Persulfidation | [
"Chemistry"
] | 207 | [
"Post-translational modification",
"Gene expression",
"Biochemical reactions"
] |
63,621,945 | https://en.wikipedia.org/wiki/Penning%E2%80%93Malmberg%20trap | The Penning–Malmberg trap (PM trap), named after Frans Penning and John Malmberg, is an electromagnetic device used to confine large numbers of charged particles of a single sign of charge. Much interest in Penning–Malmberg (PM) traps arises from the fact that if the density of particles is large and the temperature is low, the gas will become a single-component plasma. While confinement of electrically neutral plasmas is generally difficult, single-species plasmas (an example of a non-neutral plasma) can be confined for long times in PM traps. They are the method of choice to study a variety of plasma phenomena. They are also widely used to confine antiparticles such as positrons (i.e., anti-electrons) and antiprotons for use in studies of the properties of antimatter and interactions of antiparticles with matter.
Design and operation
A schematic design of a PM trap is shown in Fig. 1. Charged particles of a single sign of charge are confined in a vacuum inside an electrode structure consisting of a stack of hollow, metal cylinders. A uniform axial magnetic field is applied to inhibit positron motion radially, and voltages are imposed on the end electrodes to prevent particle loss in the magnetic field direction. This is similar to the arrangement in a Penning trap, but with an extended confinement electrode to trap large numbers of particles (e.g., ).
Such traps are renowned for their good confinement properties. This is due to the fact that, for a sufficiently strong magnetic field, the canonical angular momentum of the charge cloud (i.e., including angular momentum due to the magnetic field B) in the direction of the field is approximately
where is the radial position of the th particle, is the total number of particles, and is the cyclotron frequency, with particle mass m and charge e. If the system has no magnetic or electrostatic asymmetries in the plane perpendicular to , there are no torques on the plasma; thus is constant, and the plasma cannot expand. As discussed below, these plasmas do expand due to magnetic and/or electrostatic asymmetries thought to be due to imperfections in trap construction.
The PM traps are typically filled using sources of low energy charged particles. In the case of electrons, this can be done using a hot filament or electron gun. For positrons, a sealed radioisotope source and "moderator" (the latter used to slow the positrons to electron-volt energies) can be used. Techniques have been developed to measure the plasma length, radius, temperature, and density in the trap, and to excite plasma waves and oscillations. It is frequently useful to compress plasmas radially to increase the plasma density and/or to combat asymmetry-induced transport. This can be accomplished by applying a torque on the plasma using rotating electric fields [the so-called "rotating wall" (RW) technique], or in the case of ion plasmas, using laser light. Very long confinement times (hours or days) can be achieved using these techniques.
Particle cooling is frequently necessary to maintain good confinement (e.g., to mitigate the heating from RW torques). This can be accomplished in a number of ways, such as using inelastic collisions with molecular gases, or in the case of ions, using lasers. In the case of electrons or positrons, if the magnetic field is sufficiently strong, the particles will cool by cyclotron radiation.
History and uses
The confinement and properties of single species plasmas in (what are now known as) PM traps was first studied by John Malmberg and John DeGrassie. Confinement was shown to be excellent as compared to that for neutral plasmas. It was also shown that, while good, confinement is not perfect and there are particle losses.
Penning–Malmberg traps have been used to study a variety of transport mechanisms. Figure 2 shows an early study of confinement in a PM trap as a function of a background pressure of helium gas. At higher pressures, transport is due to electron-atom collisions, while at lower pressures, there is a pressure-independent particle loss mechanism. The latter (“anomalous transport”) mechanism has been shown to be due to inadvertent magnetic and electrostatic asymmetries and the effects of trapped particles. There is evidence that confinement in PM traps is improved if the main confinement electrode (blue in Fig. 1) is replaced by a series of coaxial cylinders biased to create a smoothly varying potential well (a “multi-ring PM trap”).
One fruitful area of research arises from the fact that plasmas in PM traps can be used to model the dynamics of inviscid two-dimensional fluid flows. PM traps are also the device of choice to accumulate and store anti-particles such as positrons and antiprotons. One has been able to create positron and antiproton plasmas and to study electron-beam positron plasma dynamics.
Pure ion plasmas can be laser-cooled into crystalline states. Cryogenic pure-ion plasmas are used to study quantum entanglement. The PM traps also provide an excellent source for cold positron beams. They have been used to study with precision positronium (Ps) atoms (the bound state of a positron and an electron, lifetime ≤ 0.1 μs) and to create and study the positronium molecule (Ps, ). Recently PM-trap-based positron beams have been used to produce practical Ps-atom beams.
Antihydrogen is the bound state of an antiproton and a positron and the simplest antiatom. Nested PM traps (one for antiprotons and another for positrons) have been central to the successful efforts to create, trap and to compare the properties of antihydrogen with those of hydrogen. The antiparticle plasmas (and electron plasmas used to cool the antiprotons) are carefully tuned with an array of recently developed techniques to optimize the production antihydrogen atoms. These neutral antiatoms are then confined in a minimum-magnetic-field trap.
See also
Penning trap
References
Particle traps | Penning–Malmberg trap | [
"Chemistry"
] | 1,308 | [
"Particle traps",
"Molecular physics"
] |
73,734,800 | https://en.wikipedia.org/wiki/Lambertella%20corni-maris | Lambertella corni-maris is a small ascomycete fungi. It grows in deciduous fruit areas, and causes postharvest Lambertella rot on apple fruits. The species also forms a mycoparasitism relationship with Monilinia fructigena. It is the type species of the genus Lambertella.
Taxonomy
Lambertella corni-maris was first described in 1918, and named for Lambert Gelbenegger. The genus Lambertella was created for the discovery of L. corni-maris.
Description
When found on apples or grown on rotting fruit in the lab, L. corni-maris forms apothecia. The apothecia are positively phototropic, though light does not affect growth. They vary in shape and color depending on maturity. They begin crateriform, then saucer-shaped, then flatten as they mature. They range from pale pink to dark brown, varied by location and age. Apothecia found on apples ranges from 1 to 5 mm, while those found on pears ranged from 1.5 to 7.5 mm.
Asci are shortly stalked, clavate, and inoperculate. The average size of asci is 100 x 7.5 μm. Asci contain eight ovoid spores, which begin colorless, and turn dark brown as they mature. Spores are unicellular and contain two vacuoles. Paraphyses are colorless, aseptate and unbranched, and numerous, either equal to or exceeding the number of asci.
Lambertella corni-maris has several unique features noted when grown on agar. Its most favorable medium contains glucose and peptone as sources of carbon and nitrogen. Optimum pH for growth is 4.4, though growth occurs from pH 1.6-8.3. The species tends to grow towards areas higher in acidity. It can grow in temperatures ranging from 5° to 30° C, and the optimum temperature is 20° C. No growth occurs at 30° C or above. While it is most often found on apples in the wild, under lab conditions it can cause disease on the fruits of pear, plum, quince, orange, lemon, as well as turnip and parsnip. It did not attack when inoculated in young wood of apple, pear, cherry, and plum.
Distribution
Lambertella corni-maris was first discovered in Austria on cherry fruits. It is distributed throughout western Europe, and has also been noted in Japan, and the Pacific northwest United States.
Postharvest rot and mycoparasitism
Lambertella corni-maris causes the disease postharvest rot, found most often on apples. Several proposed names for this disease are yellow rot, or Lambertella rot. It likely infects fruit through wounds that occur during harvest, as in the lab, non-wounded apples did not develop yellow rot. The excretion of the cell wall degrading enzyme pectinase allows L. corni-maris to attack fruits. It causes brown spongy lesions on apple fruits, and may also grow thick yellow mycelia.
Lambertella corni-maris displays antagonism to many species of fungi and bacteria. It can live alone as an apple fruit pathogen, but will also replace Monilinia species on fruit. L. corni-maris displays allelopathic activity against Monilinia fructigena, which is a species that causes brown rot on apples. In this interaction, L. corni-maris secretes the antibiotic lambertellols A and B. The lambertellols are produced both in the presence and absence of the host M. fructigena. Lambertellol production also increases under acidic conditions, or in the presence of M. fructigena, which has been found to make its surroundings acidic. Lambertellols A and B inhibit hyphal germination of M. fructigena. In acidic conditions, lambertellols A and B become stable, allowing them to diffuse towards the host. A and B then decompose into lambertellin, which inhibits the host and allows infection by L. corni-maris. This interaction has been reported to occur on potato sucrose agar and on apple fruits. The antagonistic biotic environment caused by L. corni-maris may have driven genetic divergence between Japanese and European strains of M. fructigena.
References
Helotiales
Fungus species | Lambertella corni-maris | [
"Biology"
] | 930 | [
"Fungi",
"Fungus species"
] |
73,735,462 | https://en.wikipedia.org/wiki/Anti-vaccine%20activism | Anti-vaccine activism, which collectively constitutes the "anti-vax" movement, is a set of organized activities expressing opposition to vaccination, and these collaborating networks have often sought to increase vaccine hesitancy by disseminating vaccine misinformation and/or forms of active disinformation. As a social movement, it has utilized multiple tools both within traditional news media and also through various forms of online communication. Activists have primarily (though far from entirely) focused on issues surrounding children, with vaccination of the young receiving pushback, and they have sought to expand beyond niche subgroups into national political debates.
Ideas that would eventually coalesce into anti-vaccine activism have existed for longer than vaccines themselves. Although various myths and conspiracy theories, alongside outright disinformation and misinformation, have been spread by the anti-vaccination movement and fringe doctors in a way that has significantly increased vaccine hesitancy (and altered public policy around the ethical, legal, and medical matters related to vaccines), no serious sense of hesitancy or of debate (in the broad sense) exists within mainstream medical circles about the benefits of vaccination. The scientific consensus in favor of vaccines is "clear and unambiguous". At the same time, however, the anti-vax movement has partially succeeded in distorting common understandings of science in popular culture.
Strategies and tactics
Arguments used
In a 2002 paper in the British Medical Journal, two medical historians suggested that the arguments made against the safety and effectiveness of vaccines in the late 20th century are similar to those of the early anti-vaccinationists. Both the 19th and 20th century arguments included "vaccine safety issues, vaccine failures, infringement of personal liberty, and an unholy alliance between the medical establishment and the government to reap huge profits for the medical establishment at the expense of the public." However, the authors only considered the use of "newspaper articles and letters, books, journals, and pamphlets to warn against the dangers of vaccination", and did not address the impact of the internet. Comments on YouTube videos during the COVID-19 pandemic clustered similarly around "concerns about side-effects, effectiveness, and lack of trust in corporations and government".
Misrepresentation
In some instances, anti-vaccine organizations have used names intended to sound non-partisan on the issue: e.g. National Vaccine Information Center (USA), Vaccination Risk Awareness Network (Canada), Australian Vaccination Network. In November 2013 the Australian Vaccination Network was ordered by the New South Wales Administrative Decisions Tribunal to change their name so that consumers are aware of the anti-vaccination nature of the group. Lateline reported that former AVN president Meryl Dorey "claimed she was a victim of hate groups and vested interests" in response to the ruling.
Information quality
Although physicians and nurses are still rated as the most trusted source for vaccine information, some vaccine-hesitant individuals report being more comfortable discussing vaccines with providers of complementary and alternative medical (CAM) treatments. With the rise of the internet, many people have turned online for medical information. In some instances, anti-vaccine activists seek to steer people away from vaccination and health-care providers and towards alternative medicines sold by certain activists.
Anti-vaccination writings on the internet have been argued to be characterized by a number of differences from medical and scientific literature. These include:
Promiscuous copying and reduplication.
Ignoring corrections, even when an initial report or data point is shown to be false.
Lack of references, difficulty in checking sources and claims.
Personal attacks on individual doctors.
A high degree of interlinkage between sites.
Dishonest or fallacious arguments.
For example, a 2020 study examined Instagram posts related to the HPV vaccine, which can prevent some types of cancer. Anti-vaccine posts were more likely than pro-vaccine posts to be sent by non-healthcare individuals, to include personal narratives, and to reference other Instagram users, links, or reposts. Anti-vaccine posts were also more likely to involve concealment or distortion, particularly conspiracy theories and unsubstantiated claims. In total, 72.3% of antivaccine posts made inaccurate claims, including exaggerating the risks of vaccines and minimizing risks of disease.
Disinformation tactics
A number of specific disinformation tactics have been noted in anti-vaccination messaging, including:
Asserting that the existence of the 1986 National Childhood Vaccine Injury Act implies that injury from vaccines is likely instead of very rare
Claiming to fail to access clinical trial data
Conspiracies theories alleging lies, trickery, cover-ups, and secret knowledge
Messages crafted for psychological appeal rather than truthfulness
Fake experts
Impossible expectations: claiming that anything less than 100% certainty in a scientific claim implies doubt, and that doubt means there is no consensus
Selective cherry-picking: using obscure or debunked sources while ignoring counter-evidence and scientific consensus
Shifting hypotheses: Continually introducing new theories about vaccines being harmful; moving to new claims when existing ones are shown to be false
Misrepresentation, false logic and illogical analogies
Personal attacks on critics, ranging from online criticism, publicly revealing personal details, and threats, to offline activities such as legal actions, targeting of employers, and violence
Targeting China's vaccine: During the pandemic, as retaliation for China's attempts to blame the United States for the pandemic, The Pentagon targeted China's Sinovac COVID-19 vaccine by spreading anti-vaccine misinformation in the Philippines.
Economics of vaccine disinformation
Information is more likely to be believed after repeated exposure. Disinformers use this illusory truth effect as a tactic, repeating false information to make it feel familiar and influence belief. Anti-vaccine activists have leveraged social media to develop interconnected networks of influencers that shape people's opinion, recruit allies, impact policy and monetize vaccine-related disinformation.
In 2022, the Journal of Communication published a study of the political economy underlying vaccine disinformation. Researchers identified 59 English-language "actors" that provided "almost exclusively anti-vaccination publications". Their websites monetized disinformation through appeals for donations, sales of content-based media and other merchandise, third-party advertising, and membership fees. Some maintained a group of linked websites, attracting visitors with one site and appealing for money and selling merchandise on others. Their activities to gain attention and obtain funding displayed a "hybrid monetization strategy". They attracted attention by combining eye-catching aspects of "junk news" and online celebrity promotion. At the same time, they developed campaign-specific communities to publicize and legitimize their position, similar to radical social movements.
Misrepresentation of the Vaccine Adverse Event Reporting System
In the United States, the Vaccine Adverse Event Reporting System (VAERS) is used to gather information on potential vaccine adverse reactions, but is susceptible to unverified reports, misattribution, underreporting, and inconsistent data quality. Raw, unverified data from VAERS has often been used by the anti-vaccine community to justify misinformation regarding the safety of vaccines; it is generally not possible to find out from VAERS data if a vaccine caused an adverse event, or how common the event might be.
Legal action
After Republicans gained a majority in the U.S. House of Representatives in January 2023, the House Judiciary Committee used legal action to oppose both disinformation research and government involvement in fighting disinformation. One of the projects targeted was the Virality Project, which has examined the spread of false claims about vaccines. The House Judiciary Committee sent letters, subpoenas, and threats of legal action to researchers, demanding notes, emails and other records from researchers and even student interns, dating back to 2015. Institutions subjected to such inquiries included the Stanford Internet Observatory at Stanford University, the University of Washington, the Atlantic Council's Digital Forensic Research Lab and the social media analytics firm Graphika. Researchers emphasized that they have academic freedom to study disinformation as well as freedom of speech to report their results.
Despite conservative claims that the government acted to censor speech online, "no evidence has emerged that government officials coerced the companies to take action against accounts". The actions of the House Judiciary Committee have been described as an "attempt to chill research,” creating a "chilling effect" through increased time demands, legal costs and online harassment of researchers.
Harassment
Persons undertaking efforts to counter vaccine misinformation, including public health experts who use social media, have been targeted for harassment by anti-vaccine activists. For example, Slovakian physician Vladimír Krčméry was a prominent member of the government advisory team during the COVID-19 pandemic in Slovakia, and was the first person in that country to receive a COVID-19 vaccine. Due to his prominent role in the vaccination campaign, Krčméry and his family became a target of anti-vaccine activists, who physically threatened him and his family.
In June 2023, Texas-based physician and researcher Peter Hotez tweeted his concerns about Robert F. Kennedy Jr. sharing misinformation about vaccines on Joe Rogan's podcast. Rogan, Kennedy, and Twitter owner Elon Musk asked Hotez to participate in a debate on the podcast. Upon declining the invitation, Hotez was harassed by their fans, with anti-vaccine activist Alex Rosen confronting him at his home.
In his book The Deadly Rise of Anti-science: A Scientist's Warning, Hotez describes how he and other scientists who publicly defend vaccines have been attacked on social media, harassed with threatening emails, intimidated, and confronted physically by opponents of vaccination. He attributes the increase in aggressiveness of the anti-vaccination movement to the influence of the extreme wing of the Republican Party. Hotez estimates that roughly 200,000 preventable deaths from COVID-19, mainly among Republicans, occurred in the US because of refusal to be vaccinated.
At the extreme end, opposition to vaccination has resulted in substantial violence against vaccinators. In Pakistan, "more than 200 polio team workers have lost their lives" (team members include not only vaccinators but police and security personnel) from "targeted killing and terrorism" while working on polio vaccination campaigns.
Countering anti-vaccine activism
Various efforts have been suggested and undertaken to address concerns about vaccines and counter anti-vaccine disinformation. Efforts include social media advertising campaigns, by public health organizations, in support of public health goals.
Best practices for combating vaccine mis- and disinformation include addressing issues openly, clearly identifying areas of scientific consensus and areas of uncertainty, and being sensitive to the cultural and religious values of communities. In countering anti-vaccine disinformation, both factual and emotional aspects need to be addressed.
Whether people will update a mistaken belief is complicated and involves psychological factors and social goals as well as accuracy of information. There is some evidence that both debunking and "pre-bunking" of disinformation can be effective, at least in the short term. Elements that may help to correct inaccurate information include: warning people before they are exposed to misinformation; high perceived credibility of message sources, affirmations of identity and social norms; graphical presentation; and focusing attention on clear core messages.
Alternative explanations of a situation need to fit plausibly into the original scenario and ideally indicate why the incorrect explanation was previously thought to be correct.
The cultivation of critical thinking, health and science awareness, and media literacy skills are all recommended to help people more critically assess the credibility of the information they see. People who seek out multiple reputable news sources at local and national levels are more likely to detect disinformation than those who rely on few sources from a particular viewpoint. Particularly on social media, beware of sensational headlines that appeal to emotion, fact-check information broadly (not just through your usual sources), and consider possible agendas or conflicts of interest of those relaying information.
Operation of social media
Other suggestions for countering anti-vaccine activism focus on changing the operation of social media platforms. Interventions such as accuracy nudges and source labeling change the context in which information is presented. For example, correct information can be directly presented to counter disinformation.
Other possibilities include flagging or removing misleading information on social media platforms. Research suggests that a majority of individuals in the United States would support the removal of harmful misinformation posts and the suspension of accounts. This position is less popular with Republicans than Democrats.
While private entities like Facebook, Twitter and Telegram could legally establish guidelines for moderation of information and disinformation on their platforms (subject to local and international laws) such companies do not have strong incentives to control disinformation or to self-regulate. Algorithms that are used to maximize user engagement and profits can lead to unbalanced, poorly sourced, and actively misleading information.
Criticized for its role in vaccine hesitancy, Facebook announced in March 2019 that it would provide users with "authoritative information" on the topic of vaccines. Facebook introduced several policies chosen to reduce the impact of anti-vaccine content, without actually removing it. These included reducing the ranking of anti-vaccine sources in searches and not recommending them; rejecting ads and targeted advertising that contained vaccine misinformation; and using banners to present vaccine information from authoritative sources. A study examined the six months before and after the policy changes. It found a moderate but significant decrease in the number of likes for anti-vaccine posts following the policy changes. Likes of pro-vaccine posts were unchanged. Facebook has been criticized for not being more aggressive in countering disinformation. In response to efforts to police misinformation, anti-vaccine communities on social media have adopted coded language to refer to vaccinated persons and the vaccines themselves.
Supply-side interventions reduce circulation of misinformation directly at their sources through actions such as application of social media policies, regulation, and legislation.
A study published in the journal Vaccine examined advertisements posted in the three months prior to the Facebook's 2019 policy changes. It found that 54% of the anti-vaccine advertisements on Facebook were placed by just two organizations, funded by well-known anti-vaccination activists. The Children's Health Defense / World Mercury Project chaired by Robert F. Kennedy Jr. and Stop Mandatory Vaccination, run by campaigner Larry Cook, posted 54% of the advertisements. The ads often linked to commercial products, such as natural remedies and books. Kennedy was suspended from Facebook in August 2022, but reinstated in June 2023.
In 2023, however, state governments that were politically aligned with anti-vaccine activists successfully sought a preliminary injunction to prevent the Biden Administration from seeking to pressure social media companies into fighting misinformation. The order issued by United States Court of Appeals for the Fifth Circuit "severely limits the ability of the White House, the surgeon general, [and] the Centers for Disease Control and Prevention... to communicate with social media companies about content related to Covid-19... that the government views as misinformation". In October 2023, this injunction was paused by the Supreme Court of the United States, pending further litigation.
Use of algorithms and data
Algorithms and user data can be used to identify selected subgroups who can then be provided with specialized content. This type of approach has been used both by anti-vaccine activists
and by health providers who hope to counter vaccine-related disinformation.
For example, in the United States, the CDC's Social Vulnerability Index (SVI) has been used to identify communities that have traditionally been under-served or are at elevated risk for infection, morbidity, and mortality. Programs have been developed in such communities to address disinformation and vaccine hesitancy.
Community engagement
Steps have been taken to counter anti-vaccine messaging by directly engaging with communities. Outreach efforts include call centers and texting campaigns, partnering with local community leaders, and holding community-based vaccine clinics. Creating digital and science literacy resources and distributing them via schools, libraries, municipal offices, churches and other community groups can help to counter misinformation in under-resourced communities.
The Black Doctors COVID-19 Consortium in Philadelphia is one example of a successful direct outreach initiative. Another is the New York State Vaccine Equity Task Force.
In line with the Strategic Advisory Group of Experts (SAGE)'s 3C's model, outreach to communities has focused on addressing mistrust and increasing Confidence, providing information to improve risk assessment (Complacency), and improving access to COVID-19 vaccines (Convenience). It has been necessary to counter disinformation in all three areas.
Recommendations for combating vaccine disinformation include increasing the presence of trusted health agencies and credible information on social media, partnering with social media platforms to promote evidence-based public health information, and identifying and responding to emerging concerns and disinformation campaigns.
Networked communities of public health officials and other stakeholders, connecting with the public through a variety of credible and trusted messengers, are recommended. Sharing of messages through such networks could help to debunk and counter highly networked and coordinated disinformation attacks.
A networked community approach would differ from the current model of US public health communication, which tends to rely on a single credible messenger (e.g. Anthony Fauci) and is susceptible to disinformation attacks. To deal with disinformation, community networks would need to address issues of liberty and human rights as well as vaccine safety, effectiveness and access. Networks could also help to show support for those attacked by anti-vaccine activists.
History
18th and 19th century
Ideas that would eventually coalesce into anti-vaccine activism have existed for longer than vaccines themselves. Some philosophical approaches (e.g. homeopathy, vitalism) are incompatible with the microbiological paradigm that explains how the immune system and vaccines work. Vaccine hesitancy and anti-vaccine activism exist within a broader context that involves cultural tradition, religious belief, approaches to health and disease, and political affiliation.
Opposition to variolation for smallpox (a predecessor to vaccination) was organized as early as the 1720s around the premise that vaccination was unnatural and an attempt to thwart divine judgment. Religious arguments against inoculation, the earliest arguments against vaccination, were soon advanced. For example, in a 1722 sermon entitled "The Dangerous and Sinful Practice of Inoculation", the English theologian Reverend Edmund Massey argued that diseases are sent by God to punish sin and that any attempt to prevent smallpox via inoculation is a "diabolical operation". It was customary at the time for popular preachers to publish sermons, which reached a wide audience. This was the case with Massey, whose sermon reached North America, where there was early religious opposition, particularly by John Williams. A greater source of opposition there was William Douglass, a medical graduate of Edinburgh University and a Fellow of the Royal Society, who had settled in Boston.
Vaccination itself was invented by British physician Edward Jenner, who published his findings on the efficacy of the practice for smallpox in 1798. By 1801, the practice had been widely endorsed in the scientific community, and by several world leaders. Philadelphia physician John Redman Coxe, noting that even then false accounts were circulated of negative effects of vaccination, wrote,
"Such are the falsehoods which impede the progress of the brightest discovery which has ever been made! But the contest is in vain! Time has drawn aside the veil which obstructed our knowledge of this invaluable blessing; and in the examples of the Emperor of Constantinople, of the Dowager Empress of Russia, and the King of Spain, we may date the downfall of further opposition."
Coxe's expectation of an end to opposition to vaccination proved premature, and through much of the nineteenth century, the principles, practices and impact of vaccination were matters of active scientific debate. The principles behind vaccination were not clearly understood until the end of the nineteenth century. The importance of hygiene in the preparation, storage, and administration of vaccines was not always understood or practiced. Reliable statistics on vaccine efficacy and side effects were difficult to obtain before the 1930s.
Anti-Compulsory Vaccination League
In the United Kingdom, the Compulsory Vaccination Act of 1853 required that every child be vaccinated within three or four months of birth. It set a precedent for the state regulation of physical bodies, and was fiercely resisted.
The following year, in 1854, John Gibbs published the first anti-compulsory-vaccination pamphlet, Our Medical Liberties.
By the 1860s, anti-vaccinationism in Britain was active in the working class, labor aristocracy, and lower middle class. It had become associated with alternative medicine and was part of a larger culture of social and political dissent that included both labor unions and religious dissenters.
In June 1867, the publication "Human Nature" campaigned in the United Kingdom against "The Vaccination Humbug", reporting that many petitions had been presented to Parliament against Compulsory Vaccination for smallpox, including from parents who alleged that their children had died through the procedure, and complaining that these petitions had not been made public. The journal reported the formation of the Anti-Compulsory Vaccination League "To overthrow this huge piece of physiological absurdity and medical tyranny", and quoted Richard Gibbs (a cousin of John Gibbs) who ran the Free Hospital at the same address as stating "I believe we have hundreds of cases here, from being poisoned with vaccination, I deem incurable. One member of a family dating syphilitic symptoms from the time of vaccination, when all the other members of the family have been clear. We strongly advise parents to go to prison, rather than submit to have their helpless offspring inoculated with scrofula, syphilis, and mania".
Notable members of the Anti-Compulsory Vaccination League included James Burns, George Dornbusch and Charles Thomas Pearce. After the death of Richard B. Gibbs in 1871, the Anti-Compulsory Vaccination League "languished" until 1876 when it was revived under the leadership of Mary Hume-Rothery and the Rev. W. Hume-Rothery. The Anti-Compulsory Vaccination League published the Occasional Circular which later merged into the National Anti-Compulsory Vaccination Reporter.
Anti-Vaccination Society of America
In the United States, many states and local school boards established immunization requirements, beginning with a compulsory school vaccination law in Massachusetts in 1855.
The Anti-Vaccination Society of America was founded in 1879, after a visit to the United States by British anti-vaccine activist William Tebb, and opposed compulsory smallpox vaccination for smallpox from the final decades of the 19th century through the 1910s. During this period, smallpox vaccination was the only form of vaccination that was widely practiced, and the society published a periodical opposing it, called Vaccination.
A series of American legal cases, beginning in various states and culminating with that of Henning Jacobson of Massachusetts in 1905, upheld the mandating of compulsory smallpox vaccination for the good of the public. The court ruled in Jacobson v. Massachusetts that "the liberty secured by the Constitution of the United States to every person within its jurisdiction does not import an absolute right in each person to be, at all times and in all circumstances, wholly freed from restraint. There are manifold restraints to which every person is necessarily subject for the common good".
London Society for the Abolition of Compulsory Vaccination
In 1880, William Tebb enlarged and reorganized the Anti-Compulsory Vaccination League in the UK with the formation of the London Society for the Abolition of Compulsory Vaccination, with William Young as secretary. The Vaccination Inquirer, established by Tebb in 1879, was adopted as the official organ of the Society. A series of fourteen "Vaccination Tracts" was begun by Young in 1877 and completed by Garth Wilkinson in 1879. William White was the first editor of the Vaccination Inquirer and after his death in 1885, he was succeeded by Alfred Milnes. Frances Hoggan and her husband authored an article for the Vaccination Inquirer in September 1883 which argued against compulsory vaccination. The London Society focused on lobbying parliamentary support in the 1880s and early 1890s. They gained support from several members of the House of Commons of which the most prominent was Peter Alfred Taylor, the member for Leicester, which was described as the "Mecca of antivaccination".
The National Anti-Vaccination League
The UK movement grew, and as the influence of the London Society overshadowed the Hume-Rotherys and it took the national lead, it was decided in February 1896 to re-form the Society as The National Anti-Vaccination League. Arthur Phelps was elected as president. In 1898, the league took on a school leaver named Lily Loat, who was elected as the league's Secretary by 1909. In 1906, George Bernard Shaw wrote a supportive letter to the National Anti-Vaccination League, equating methods of vaccination with "rubbing the contents of the dustpan into the wound".
Anti-Vaccination League of America
In 1908, the Anti-Vaccination League of America was created by Charles M. Higgins and industrialist John Pitcairn Jr., with anti-vaccination campaigns focused on New York and Pennsylvania. Members were opposed to compulsory vaccination laws. Higgins was the League's chief spokesman and pamphleteer. Historian James Colgrove noted that Higgins "attempted to overturn the New York State's law mandating vaccination of students in public schools". The League should not be confused with the Anti-Vaccination Society of America, that was formed in 1879. Higgins was criticized by medical experts for spreading misinformation and ignoring facts as to the efficacy of vaccination. The League dissolved after the death of Higgins in 1929.
20th century
Anti-vaccine activism ebbed for much of the twentieth century, but never completely vanished. In the UK, the National Anti-Vaccination League continued to publish new issues of its journal until 1972, by which time the global campaign for smallpox eradication through vaccination had made the disease so uncommon that compulsory vaccination for smallpox was no longer required in the United Kingdom.
New vaccines were developed and used against diseases such as diphtheria and whooping cough. In the UK, these were often introduced on a voluntary basis, without arousing the same kind of anti-vaccination response that had accompanied compulsory smallpox vaccination.
In the United States, numerous measles outbreaks occurred in the 1960s and 1970s, and were shown to be more frequent in states that lacked mandatory vaccination requirements. This led to calls in the 1970s for a national level vaccination requirement for children entering schools.
Joseph A. Califano Jr. appealed to state governors, and by 1980, all 50 states legally required vaccination for school entrance. Many of these laws allowed exemptions in response to lobbyists. In New York State, a 1967 law allowed exemptions from receiving polio vaccine for members of religious organizations such as Christian Scientists.
21st century
Lancet MMR autism fraud
Anti-vaccine activism in the 2000s regained prominence through exploratory research by Andrew Wakefield based on 12 selected cases. He then made claims about a link between the MMR vaccine and autism. These claims were subsequently extensively investigated and found to be false, and the original study turned out to be based on faked data. The scientific consensus is that there is no link between the MMR vaccine and autism, and that the MMR vaccine's benefits in preventing measles, mumps, and rubella greatly outweigh its potential risks.
The idea of an autism link was first suggested in the early 1990s and came to public notice largely as a result of the 1998 Lancet MMR autism fraud, which Dennis K Flaherty at the University of Charleston characterized as "perhaps the most damaging medical hoax of the last 100 years". The fraudulent research paper authored by Wakefield and published in The Lancet falsely claimed the vaccine was linked to colitis and autism spectrum disorders. The paper was retracted by Lancet in 2010 but is still cited by anti-vaccine activists.
The claims in the paper were widely reported, leading to a sharp drop in vaccination rates in the UK and Ireland. Promotion of the claimed link, which continued in anti-vaccination propaganda for the next three decades despite being refuted, was estimated to have led to an increase in the incidence of measles and mumps, resulting in deaths and serious permanent injuries. Following the initial claims in 1998, multiple large epidemiological studies were undertaken. Reviews of the evidence by the Centers for Disease Control and Prevention, the American Academy of Pediatrics, the Institute of Medicine of the US National Academy of Sciences, the UK National Health Service, and the Cochrane Library all found no link between the MMR vaccine and autism. Physicians, medical journals, and editors have described Wakefield's actions as fraudulent and tied them to epidemics and deaths.
An investigation by journalist Brian Deer found that Wakefield, the author of the original research paper linking the vaccine to autism, had multiple undeclared conflicts of interest, had manipulated evidence, and had broken other ethical codes. After a subsequent 2.5-year investigation, the General Medical Council ruled that Wakefield had acted "dishonestly and irresponsibly" in doing his research, carrying out unauthorized procedures for which he was not qualified, and acting with "callous disregard" for the children involved.
Wakefield was found guilty by the General Medical Council of serious professional misconduct in May 2010, and was struck off the Medical Register, meaning he could no longer practise as a physician in the UK.
The Lancet paper was partially retracted in 2004 and fully retracted in 2010, when Lancets editor-in-chief Richard Horton described it as "utterly false" and said that the journal had been deceived. In January 2011, Deer published a series of reports in the British Medical Journal, in which a signed editorial stated of the journalist, "It has taken the diligent scepticism of one man, standing outside medicine and science, to show that the paper was in fact an elaborate fraud." A 2011 journal article described the vaccine-autism connection as "the most damaging medical hoax of the last 100 years".
Wakefield continues to promote anti-vaccine beliefs and conspiracy theories in the United States.
In February 2015, Wakefield denied that he bore any responsibility for the measles epidemic that started at Disneyland among unvaccinated children that year. He also reaffirmed his discredited belief that "MMR contributes to the current autism epidemic". By that time, at least 166 measles cases had been reported. Paul Offit disagreed, saying that the outbreak was "directly related to Dr. Wakefield's theory".
Wakefield and other anti-vaccine activists were active in the American-Somali community in Minnesota, where a drop in vaccination rates was followed by the largest measles outbreak in the state in nearly 30 years in 2017.
The anti-vaccination movement was historically apolitical, but in the 2010s and 2020s the movement in the United States has increasingly targeted conservatives. As measles outbreaks increased, so did calls to eliminate exemptions from vaccine administration. As of 2015, 19 American states had suggested legislation to eliminate or increase the difficulty of exemptions, including California. Concurrently, American anti-vaccine activists reached out to libertarian and right-leaning groups such as the Tea Party movement to broaden their base. While earlier anti-vaccination activists focused on health impacts and safety of vaccines, recent themes increasingly involve philosophical arguments about liberty, medical freedom and parental rights.
With the growing anti-vaccine movement from the 2010s onwards, the United States has seen a resurgence of certain vaccine-preventable diseases. The measles virus lost its elimination status in the US as the number of measles cases continued to rise in the late 2010s with a total of 17 outbreaks in 2018 and 465 outbreaks in 2019 (as of April 4, 2019).
2019 measles outbreaks
Vaccine hesitancy led to declining rates of vaccination for measles, culminating in the 2019–2020 measles outbreaks. The most significant of these in proportion to national population was the 2019 Samoa measles outbreak.
In July 2018, two 12-month-old children died in Samoa after receiving incorrectly prepared MMR vaccinations. These two deaths were picked up by anti-vaccine groups and used to incite fear towards vaccination on social media, causing the government to suspend its measles vaccination programme for ten months, despite advice from the WHO. The incident caused many Samoan residents to lose trust in the healthcare system. UNICEF and the World Health Organization estimate that the measles vaccination rate in Samoa fell from 74% in 2017 to 34% in 2018, similar to some of the poorest countries in Africa.
In August 2019, an infected passenger on one of the more than 8,000 annual flights between New Zealand and Samoa probably brought the disease from Auckland to Upolu. A full outbreak of measles began on the island in October 2019 and continued for the next four months. As of January 6, 2020, there were over 5,700 cases of measles and 83 deaths, out of a Samoan population of 200,874. Over three percent of the population were infected. The cause of the outbreak was attributed to decreased vaccination rates, from 74% in 2017 to 31–34% in 2018, even though nearby islands had rates near 99%. a rate of 14.3 deaths per 1000 infected) and 5,520 cases (2.75% of the population) of measles in Samoa. Sixty-one out of the first 70 deaths were four years old and under, and all but seven were under 15. After the outbreak, anti-vaxxers employed racist tropes and misinformation to credit the scores of measles deaths to poverty and poor nutrition or even to the vaccine itself, but this has been discounted by the international emergency medical support that arrived in November and December. There was no evidence of acute malnutrition, clinical vitamin A deficiency, or immune deficiency as claimed by various anti-vaxxers.
COVID-19 pandemic activism
During the COVID-19 pandemic, anti-vaccine activists undertook various efforts to hinder people who wanted to receive the vaccines, with such activities occurring in countries including Australia, Israel, the United Kingdom, and the United States. These included attempts to physically blockade vaccination sites, and making false reservations for vaccination appointments to clog up vaccination booking systems. Protests were also organized by the activists to raise awareness for their cause.
In some instances, anti-vaccine rhetoric has been traced to state-sponsored internet troll activities designed to create social dissension. Worldwide, foreign disinformation campaigns have been associated with declining vaccination rates in target countries.
Anti-vaccine activism online both before and during the pandemic has been linked to extreme levels of falsehoods, rumors, hoaxes, and conspiracy theories.
Anti-vaccine activists have falsely claimed in social media posts that numerous deaths or injuries had to do with reactions to vaccines. In one highly publicized instance in early 2023, after Buffalo Bills football player Damar Hamlin experienced an in-game episode of commotio cordis, there was an increase in rhetoric and disinformation from figures such as Charlie Kirk and Drew Pinsky making unfounded claims about Hamlin's cardiac arrest and COVID-19 vaccines. In another 2023 incident, college basketball player Bronny James experienced cardiac arrest at the Galen Center at the University of Southern California, leading to assertions that this was a result of receiving a COVID-19 vaccine; it was later revealed that the episode had been caused by a congenital heart defect. Also, anti-vaccine activists believed Foo Fighters drummer Taylor Hawkins died in 2022 from the COVID-19 vaccine, while in actuality it was a drug overdose. In December 2023, The New York Times published a detailed investigation of the distortion and misrepresentation of the circumstances surrounding the death of 24-year-old George Watts Jr. by Robert F. Kennedy Jr. and other anti-vaccine activists. Some unvaccinated persons opposed to COVID-19 vaccination began referring to themselves in social media groups as "purebloods", a term historically connoting racial purity.
Prominent biomedical researcher Peter Hotez, asserted that he and other American scientists who publicly defend vaccines have been attacked on social media, harassed with threatening emails, intimidated, and confronted physically by opponents of vaccination. He further attributes the increase in aggressiveness of the anti-vaccination movement to the influence of the extreme wing of the Republican Party. Hotez estimates that roughly 200,000 preventable deaths from COVID-19, mainly among Republicans, occurred in the US because of refusal to be vaccinated. A 2023 study published in the Journal of the American Medical Association found "evidence of higher excess mortality for Republican voters compared with Democratic voters in Florida and Ohio after, but not before, COVID-19 vaccines were available to all adults in the US".
See also
Anti-vaccinationism in chiropractic
Big Pharma conspiracy theories
COVID-19 vaccine misinformation and hesitancy
Germ theory denialism
List of anti-vaccination groups
Oral polio AIDS hypothesis
Vaccine misinformation
Vaccines and autism
MMR vaccine and autism
Thiomersal and vaccines
References
Autism pseudoscience
Health-related conspiracy theories
Activism by issue | Anti-vaccine activism | [
"Technology"
] | 7,856 | [
"Health-related conspiracy theories",
"Science and technology-related conspiracy theories"
] |
73,738,893 | https://en.wikipedia.org/wiki/Golovinomyces%20orontii | Golovinomyces orontii is a species of fungus that causes powdery mildew disease and it is in the family Erysiphaceae. It is an obligate biotroph that infects plants in several families including Acanthaceae, Asteraceae, Brassicaceae, Cucurbitaceae, and Lamiaceae.
Taxonomy
Previously known as Erysiphe orontii, by Castagne (1851). It is now known by Golovinomyces orontii by Heluta (1988).
Description
Causes powdery mildew disease in multiple families including Acanthaceae, Asteraceae, Brassicaceae, Cucurbitaceae, etc. Conidia is produced on the surface of the infected plant and that as well as hyphal growth gives it its white powdery appearance. Conidia are dispersed through the wind, water droplets, and similar methods to nearby plants to start new infections. The mycelium is able to absorb nutrients through haustoria.
Disease symptoms
When Golovinomyces orontii infects its host plants, it causes a disease commonly known as powdery mildew. This gives the appearance of white, powdery sections on the surface of the plant. These powdery sections are caused by an abundance of conidia and mycelium. This can lead to deformation, discoloration, reduced growth, and death in the host plant
Lifecycle
The lifecycle begins when a conidia lands on the surface of a host plant. The conidia then develop germ tubes, forming an appressorium, that later forms into haustoria. These haustoria are used to siphon nutrients needed for growth.
Golovinomyces orontii completes a full life cycle within a few days. The fungus produces new conidia asexually, which are easily dispersed to nearby susceptible plants. These conidia can initiate new infections, leading to the spread of the disease.
Ascomata (chasmothecia) are rarely formed on most hosts. Chasmothecia may form under unfavorable conditions. Chasmothecia are resistant structures that protect the sexual spores (ascospores) of the fungus. They can remain viable for extended periods and serve as a means of survival until conditions become favorable again.
Management and control
The control of Golovinomyces orontii and powdery mildew diseases generally involves a combination of chemical and nonchemical strategies. Nonchemical strategies include; proper plant spacing, pruning and removing infected plant parts, avoiding overhead irrigation, improving ventilation, and crop rotation. Natural Fungicides by be used as well. In severe cases, fungicides can be applied, but it is important to minimize the environmental risk of these fungicides and the prevention of resistance. For many vegetable crops, sulfur, copper-based products, chlorothalonil, horticultural oil, potassium bicarbonate, and Bacillus subtilis can be used for powdery mildew control.
References
Fungal plant pathogens and diseases
Eudicot diseases
orontii
Fungus species | Golovinomyces orontii | [
"Biology"
] | 637 | [
"Fungi",
"Fungus species"
] |
73,739,952 | https://en.wikipedia.org/wiki/35%20Leonis | 35 Leonis (HIP 53019, HD 89010) is a spectroscopic binary star system located in the constellation of Leo, next to the star Zeta Leonis. It is located from Earth based upon parallax measurements. The system consists of a G-type star (yellow dwarf) and a red dwarf star. With an apparent magnitude of 5.97, it can be naked-eye visible only from dark skies.
Properties
35 Leonis was discovered to be a binary system in 2024, after analysis from Daniel Echeverri et al. using vortex fiber nulling, which is a technique for detecting and characterizing faint stellar companions that are close to their parent star. The team derived a visual separation of 56.9 milliarcseconds between both components using the CHARA array. Both stars are completing one orbit around each other every . The system classifies as a single-lined spectroscopic binary (SB1).
35 Leonis the Flamsteed designation. Other designations for this system include HD 89010 from the Henry Draper Catalogue, HIP 53019 from the Hipparcos Catalogue and HR 4030 from the Bright Star Catalogue.
35 Leonis A
The main component, 35 Leonis A, is currently a main-sequence star that is evolving into a subgiant, based on its spectral class of G1.5V-IV. It has 34% more mass than the Sun, 2.12 times the radius of the Sun, and irradiates four times more luminosity than it. The effective temperature of 35 Leonis A is , which gives it the typical hue of a G-type star. The age of the star is around 5.25 billion years, which is around 14% older than the Solar System.
35 Leonis B
The secondary component, 35 Leonis B, is a red dwarf star. The mass of 35 Leonis B is estimated at , based on a mass of for the primary and a mass ratio of 0.11. An effective temperature of and an upper limit in the rotational velocity of are derived from the vortex fiber nulling's parameters. Other characteristics, such as the radius and luminosity, are unknown.
Notes
References
Spectroscopic binaries
Leo (constellation)
Henry Draper Catalogue objects
Hipparcos objects
Bright Star Catalogue objects
G-type subgiants
Durchmusterung objects | 35 Leonis | [
"Astronomy"
] | 487 | [
"Leo (constellation)",
"Constellations"
] |
73,740,195 | https://en.wikipedia.org/wiki/NGC%204747 | NGC 4747 is a barred spiral galaxy located in the constellation Coma Berenices. It is located at a distance of about 35 million light years from Earth, which, given its apparent dimensions, means that NGC 4747 is about 35,000 light years across. It was discovered by William Herschel on April 6, 1785. It is included in the Atlas of Peculiar Galaxies in the interior absorption category.
The galaxy is a member of the Coma I Group, which is part of the Local Supercluster. NGC 4747 is interacting with neighboring spiral galaxy NGC 4725, with its spiral arms showing indications of warping. The pair have an angular separation of , which corresponds to a projected linear separation of . A close approach between NGC 4747 and the more massive NGC 4725 that took place 320 million years before observed created tidal plumes in NGC 4747.
A short tidal plume extends from NGC 4747 toward NGC 4725, to the south-west, and one more pronounced towards the north-east, with a length of 8 arcminutes. The optical north-east plume has also a hydrogen counterpart, which is offset by 50 degrees from the visual counterpart. Two knots, possibly star clusters, are visible in the northeast plume, that could become tidal dwarf galaxies, as they appear to be massive enough to be self-gravitating.
The star formation rate of the galaxy is estimated to be 0.13 solar masses per year.
References
External links
NGC 4747 on SIMBAD
Barred spiral galaxies
Peculiar galaxies
Coma I Group
Coma Berenices
4747
08005
43586
159
Discoveries by William Herschel | NGC 4747 | [
"Astronomy"
] | 329 | [
"Coma Berenices",
"Constellations"
] |
73,740,819 | https://en.wikipedia.org/wiki/Candida%20haemulonii | Candida haemulonii is a yeast fungal pathogen that is known to cause infections in humans. C. haemulonii is an emerging opportunistic pathogen that is found in hospitals and healthcare settings. Infections are difficult to treat because the fungus has resistance to antifungal agents. Since its emergence, little research has been conducted on this fungus. However, in recent years, research has been conducted to help identify the various properties of C. haemulonii.
Taxonomy
The fungus was first classified as Torulopsis haemuli in 1962. In 1978, the fungus became classified as Candida haemulonii.
Morphology
Oval cells are present at a microscopic level. The fungus has the ability to switch from a filamentous phenotype to a yeast phenotype given temperature differences. This allows the fungus to survive within different environments at different temperatures.
Habitat
Since the fungus has yeast properties, it has the ability to survive in soil and water. The fungus has been present in various outbreaks around the globe, including in hospitals within patients where the fungus has increased resistance to antifungals. This indicates its ability to survive and reside in human bodies. As well, it is an indication it can survive on non-living surfaces. Due to the fungus's ability to switch phenotypes given the temperature, it is implied that the fungus can survive within a wide temperature range in order to adapt to the external environment and continue to survive.
Geographical distribution and outbreaks
There have been an increased number of global outbreaks where this strain of fungus was found. The original locations of the fungus is reported to have been the Atlantic Ocean. Researchers noted that they found traces of the fungus on the skin of dolphins and the seawater of the coast of Portugal.
A study in 2001 reported that the fungus was associated with an epidemic in a laboratory maintained colony in the Czech Republic.
A study in 2015 reported how the fungus was found in patients in Brazilian hospitals. This study reported antifungal multi-resistant properties.
Recent studies around 2020 report C. haemulonii as an opportunistic pathogen in hospitals across the United States.
The fungus has been reported in diverse regions around the world. This would corroborate how the species has properties that allow it to adapt to different temperatures in different environments because each of the mentioned regions have climates that are distinct from one another.
Medical relevance
Amphotericin B, fluconazole, and itraconazole are antifungal agents that have been used against C. haemulonii in immunocompromised patients. The fungus was reported to be resistant to these antifungal agents. In addition, the fungus is resistant to azoles and echinocandins, which are also antifungal drugs.
The fungus is reported to have a tendency to cause chronic lower extremity wounds. The fungus is also more likely to negatively impact diabetic patients. The fungus has been isolated from the nails of diabetic patients. It has also been associated with toe ulcers and renal failure.
A study delved into how the case fatality rate of C. haemulonii is 83.33%. Immunological studies showed that the species stimulated genes involved in proinflammatory cytokine group, indicating the species can impact the inflammatory pathway.
References
haemulonii
Pathogenic microbes
Fungal pathogens of humans
Fungus species | Candida haemulonii | [
"Biology"
] | 711 | [
"Fungi",
"Fungus species"
] |
73,741,133 | https://en.wikipedia.org/wiki/Synthetic%20exosome | Exosomes are small vesicles secreted by cells that play a crucial role in intercellular communication. They contain a variety of biomolecules, including proteins, nucleic acids and lipids, which can be transferred between cells to modulate cellular processes. Exosomes have been increasingly acknowledged as promising therapeutic tool and delivery platforms due to unique biological properties.
Biocompatibility: Exosomes are naturally occurring particles in body, which makes them highly biocompatible and less likely to activate immune response.
Targeting ability: Exosomes are assembled to express specific proteins or peptides, allowing them to target specific cells or tissues.
Natural cargo carries: Exosomes can naturally transport a variety of biomolecules, including proteins, RNA and DNA, which can be used for therapeutic purposes.
However, due to exosomes being small in size (30-150 nm), present in various biological fluids (such as blood, urine, saliva), sensitivity to environmental factors (such temperature, pH), complexity of drug loading efficiency, there are challenges associated with isolation, purification, delivery and drug payload.
While application of exosomes is still in its early stages, approaches are being explored to produce exosome-like nanovesicles (ELNs or artificial exosomes) to overcome these challenges.
ELNs are a type of engineered exosomes designed to modify the structure and enhance the function of natural exosomes. The content of ELNs can be highly-customized to match with various medical needs, allowing for more precise control over their properties compared to natural exosomes. Additionally, ELNs can be modified with selectively expressed functional groups on the surface to enhance its targeting and uptake by cells or tissues. For example, ELNs can be engineered to enhance their stability in fluids, to target specific cell types, such ascytosol of brain cells. Further, ELNs could consistently deliver cargo mRNA with therapeutic catalase mRNA to the brain, attenuating neurotoxicity and neuroinflammation.
Above all, ELNs' properties can be tailored by researchers for specific applications with precise controlling. ELNs hold great potential as a novel approach to meet medical needs, including immunologic therapy, anti-tumor, anti-aging and regeneration.
References
Synthetic biology | Synthetic exosome | [
"Engineering",
"Biology"
] | 475 | [
"Synthetic biology",
"Molecular genetics",
"Biological engineering",
"Bioinformatics"
] |
73,741,430 | https://en.wikipedia.org/wiki/Landau-Mignotte%20bound | In algebra, a Landau-Mignotte bound (sometimes only referred to as Mignotte's bound) is one of a family of inequalities concerning a univariate integer polynomial f(x) and one of its factors h(x). A basic version states that the coefficients of h(x) are bounded independently of h(x) by an exponential expression involving only the degree and coefficients of f(x), i.e. only depending on f(x).
It has applications in computer algebra where these bounds can give a priori estimates on the run time and complexity of algorithms.
Basic version
For such that divides denote by resp. the sum of the absolute values of the coefficients of resp. and let be the degree of , then
Notation
will be univariate complex polynomials which later will be restricted to be integer polynomials, i.e. in . Explicitly
are the degrees, the leading coefficients are .
Define norms by considering the coefficients as vectors, explicitly
By the fundamental theorem of algebra has roots (with multiplicity). Set the Mahler measure of to be
Similarly define , , etc.
Landau's inequality and other basic properties
Landau proved in 1905 a key inequality linking the Mahler measure of a polynomial to its Euclidean norm.
In general norms obey the following inequalities
The Mahler measure satisfies which for non-trivial integer polynomials implies . See also Lehmer's conjecture.
The Mahler measure is multiplicative, i.e. if then
Mignotte's bound
Mignotte used Landau's inequality in 1974 to prove a basic version of the following bounds in the notation introduced above.
For complex polynomials in , if divides then
and individual coefficients obey the inequalities
If additionally and are integer polynomials in then and if is additionally monic then even . In these cases one can simplify by omitting the fraction. Including products in the analysis we have the following theorem.
Let such that divides then
Using Stirling's formula applied to binomial coefficients we get asymptotically a slight improvement when using binomial coefficients
From the bounds on the individual coefficients one can deduce the following related bound.
If is reducible then it has a non-trivial factor of degree such that
Combining this with Stirling's formula to replace the binomial coefficients leads to more explicit versions.
While the upper bounds that are independent of and only depend on are of great theoretical interest and aesthetic appeal, in practical application one has usually information about the degree of . This is why the sharper bounds that additionally depend on are often more relevant.
Sharpness of bounds
Cyclotomic polynomials
For the cyclotomic polynomials is an irreducible divisor of degree , Euler's totient function. In this case
and it is custom to denote . A result of Vaugn states for infinitely many positive integers
a superpolynomial bound in the degree .
Comparing with Mignotte's bound and using Stirling's formula as well as bounds for Euler's totient function we get for infinitely many
This leaves a gap between Mignotte's upper bound and what is known to be attained through cyclotomic polynomials. Cyclotomic polynomials cannot close this gap by a result of Bateman that states
for every for all sufficiently large positive integers we have
Also note that despite the superpolynomial growth of Vaugn's lower bound in practice looking at examples of cyclotomic polynomials the coefficients of are far smaller than Mignotte's bound.
A family of polynomials with exponential growth in the coefficients of its factors
Abbot gives the following example related to cyclotomic polynomials. Set
and consider for positive integers
Note that the degrees are resp. . Abbot shows that asymptotically for large we have
Using Mignotte's bound in the version
we compare
Ignoring the root terms leads to
Abbot claims that
An exhaustive search in low degrees suggests that this family of factorizations is close to extremal.
While there is still an exponential gap between the example and Mignotte's bound, the example shows that exponential growth is the right order for such a general bound.
Note that Abbot also compares Mignotte's bound with other types of bounds and gives examples where Mignotte's bound is best and examples where other bounds are better.
Also note that, while the cyclotomic polynomials from the previous section are irreducible factors, the factors have many factors themselves. Abbot speculates
The examples [...] compel any ideal “irreducible single factor bound” to grow with degree, though the rate of growth appears to be much slower than for single factor bounds valid for any (suitably scaled) factorization in . This suggests that such an ideal single factor bound could be very much smaller than the currently known ones.
Generalizations
Usually the Mignotte bounds are only stated for complex or integer polynomials. They are equally valid for any subring , in particular when considering only monic polynomials for which .
Any abstract number field and its ring of integers can be considered a subring of , however there can be multiple embeddings which are inequivalent with respect to absolute values. The Mignotte bounds are abstract and general enough that they hold independent of the chosen embedding. This may be taken as a hint that they are not as tight as possible in principle, as can indeed be seen from competing bounds that are sometimes better.
Applications
In computer algebra when doing effective computations with integer polynomials often the following strategy is applied. One reduces a polynomial modulo a suitable prime number to get , solves a related problem over instead of which is often simpler, and finally uses Hensel lifting to transfer the result for back to .
Hensel lifting is an iterative process and it is in general not clear when to stop it. The Landau-Mignotte bounds can supply additional a priori information that makes it possible to give explicit bounds on how often Hensel lifting has to be iterated to recover the solution for from a solution for .
In particular this can be applied to factoring integer polynomials or for computing the gcd of integer polynomials. Although effective, this approach may not be the most efficient, as can be seen in the case of factoring.
See also
Mignotte's separation bound
References
Inequalities | Landau-Mignotte bound | [
"Mathematics"
] | 1,306 | [
"Binary relations",
"Mathematical relations",
"Inequalities (mathematics)",
"Mathematical problems",
"Mathematical theorems"
] |
73,741,832 | https://en.wikipedia.org/wiki/Jargonness | Jargonness is a piecewise mathematical function mapping the frequencies of a word's appearance in scientific and contemporary English corpora to a parameter quantifying the word's association with scientific jargon - the "jargonness" of that word. It is expressed mathematically as:
In the above equation, stands for the frequency of a word's appearance in a general English-language corpus and stands for its frequency in a scientific corpus.
Method of use
Both the frequencies ( and ) must be determined and then substituted in the above equation to calculate the word's jargonness. In case a word has no mention in the general English corpus, 3 is taken as its jargonness as suggested by the second part of the equation. Noticing that the logarithm in the first part of the equation is a common one (to the base 10), this simply means that the word is assumed to be a thousand times more likely to appear in a scientific text than a non-scientific one.
Examples of corpora
The corpora that have most commonly been employed to determine the frequencies mentioned above are the following:
Professional English Research Consortium Corpus (for scientific vocabulary; 17 million words)
British National Corpus (for common vocabulary; 97 million words)
References
Computational linguistics
Scientific terminology | Jargonness | [
"Technology"
] | 259 | [
"Natural language and computing",
"Computational linguistics"
] |
73,741,953 | https://en.wikipedia.org/wiki/NGC%207172 | NGC 7172 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 110 million light years from Earth, which, given its apparent dimensions, means that NGC 7172 is about 100,000 light years across. It was discovered by John Herschel on September 23, 1834.
Characteristics
NGC 7172 is a spiral galaxy that is seen edge-on. A thick dark dust lane runs across the galaxy, obscuring the nucleus of the galaxy. The galaxy appears in deep photographs to be tidally distorted, and a diffuse tail is extending towards the north-west.
Nucleus
The nucleus of NGC 7172 was originally considered to be normal, but later observations revealed that it emitted X-rays and was a powerful infrared source, which exhibited variation. These findings indicated that NGC 7172 has an active galactic nucleus which is obstructed in optical wavelengths. The nucleus was classified as a type 2 Seyfert galaxy in the optical, but observations in other wavelengths suggest it is type 1 Seyfert galaxy. The source of activity of the nucleus is an accretion disk around a supermassive black hole. The mass of the supermassive black hole in the centre of NGC 7172 is estimated to be based on the MBH–σ⋆ relation or based on the X-ray scaling method.
NGC 7172 has been found to exhibit variability in X-rays. As observed by the Advanced Satellite for Cosmology and Astrophysics (ASCA), the galaxy exhibited short term variability of about 30% in the time scale of hours, which is common for Seyfert I galaxies. It also exhibits long term variability, as it dimmed three to four times between 1995 and 1996. This was also observed by BeppoSAX. The FeKα line appeared constant when observed with BeppoSAX, but appeared to variate by a factor of two by ASCA, and thus it is associated with an accretion disk. The hard X-ray spectrum appears similar to that of a Seyfert I galaxy, indicating that the nucleus is seen though a Compton-thin absorber.
In infrared observations of the nucleus dominates the spectrum of the active nucleus, with 3.4-μm carbonaceous dust absorption detected, but no 3.3-μm PAH emission, indicating that the nucleus is obstructed. A strong obsurption feature is observed, probably the 9.7-μm silicate dust absorption line. X-rays and mid-infrared have similar absorption columns. It is possible that an outflow towards the southwest is detected in radiowaves.
Nearby galaxies
NGC 7172 is part of the Hickson Compact Group 90. NGC 7172 lies 6 arcminutes north of the core of the compact group, which is comprised by the elliptical galaxies NGC 7173, and NGC 7174, and disturbed spiral galaxy NGC 7176; these three galaxies lie within 6 arcminutes from each other.
The compact group is surrounded by a more loose group, with 19 galaxies of similar redshift within 1.5 degrees from the core group. Garcia identified as members of this group the galaxies NGC 7154, ESO 404- 12, NGC 7163, ESO 466- 36, ESO 466- 46, ESO 404- 27, NGC 7187, IC 5156, ESO 404- 39, and ESO 466- 51. Other nearby galaxies include NGC 7135 and its group, NGC 7204, and NGC 7208.
See also
NGC 4388 - a similar active galaxy
References
External links
NGC 7172 on SIMBAD
Spiral galaxies
Peculiar galaxies
Seyfert galaxies
Piscis Austrinus
7172
67387
Discoveries by John Herschel
Astronomical objects discovered in 1834 | NGC 7172 | [
"Astronomy"
] | 793 | [
"Piscis Austrinus",
"Constellations"
] |
73,742,058 | https://en.wikipedia.org/wiki/Pestalotiopsis%20pauciseta | Pestalotiopsis pauciseta is an endophytic fungi isolated from the leaves of several medicinal plants in tropical climates. Pestalotiopsis pauciseta is known for its role in medical mycology, having the ability to produce a chemical compound called paclitaxel (taxol). Taxol is the first billion-dollar anticancer drug, notably the fungal-taxol produced by Pestalotiopsis pauciseta was determined to be comparable to standard taxol.
Taxonomy
Pestalotiopsis pauciseta was initially described by Pier Andrea Saccardo as Pestalotia pauciseta in 1914, and was later changed to the genus Pestalotiopsis by authors Chen, Y.X.; Wei, G. in 1993.
Description
Pestalotiopsis pauciseta has amphigenous pustules, which can range from globose to lenticular in shape, usually black, scattered and hemispherical (80-200μm). Conidiomata are eustromatic, cupulate, can be found separated or confluent, and are initially dark brown in color when immersed. After immersion, conidiomata are erumpent, thick walled, and irregularly dehisce.
Habitat/distribution
Many species of Pestalotiopsis are saprobes in soil, degraders of plant matter, or organisms growing upon rotting wild fruits. Others are plant pathogens or occupy plant leaves and twigs as endophytes. Species of Pestalotiopsis have been repeatedly isolated as saprobes from dead leaves, bark, and twigs. Species have been isolated from polluted stream water and are associated with the deterioration of wood, paper, fabrics, and decay of wool. The genus Pestalotiopsis are known as plant pathogens; P. pauciseta isolated as endophytes, likely has endophytic and pathogenic stages.
Bioactivity
Fungal-taxol is an anticancer compound that has been developed into a medication used to treat ovarian, lung, breast, and head and neck cancers. The UV absorption spectrum of taxol isolated from Pestalotiopsis pauciseta VM1 was similar to that of standard taxol with maximum absorption at 235 nm and 232 nm.
More than 130 unique compounds have been isolated from various species of Pestalotiopsis. Antifungal, anticancer, antimicrobial, and antitumor activities are some of the most significant bioactivities of secondary metabolites isolated from this genus. It is suspected that P. pauciseta is one of many fungal plant endophytes that has the ability to produce bioactive compounds that are originally from their host plant.
References
pauciseta
Fungus species | Pestalotiopsis pauciseta | [
"Biology"
] | 564 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
73,742,436 | https://en.wikipedia.org/wiki/Pixel%20Watch%202 | The Pixel Watch 2 is a Wear OS smartwatch designed, developed, and marketed by Google as part of the Google Pixel product line. It serves as the successor to the first-generation Pixel Watch.
The Pixel Watch 2 was officially announced on October 4, 2023, at the annual Made by Google event, and was released in the United States on October 12.
History
In May 2023, 9to5Google reported that Google intended to release a successor to the Pixel Watch, a Wear OS–powered smartwatch, in October. Two codenames for the watch, believed to be in reference to the Wi-Fi and cellular models, were later discovered to be "Eos" and "Aurora". Three models were approved by the Federal Communications Commission (FCC) in August, while the Eos model was listed on the Google Play Console device catalog for developers. After previewing the watch in September, Google officially announced the Pixel Watch 2 on October 4, alongside the Pixel 8 and Pixel 8 Pro, at the annual Made by Google event. Pre-orders became available the same day, before being released in 30 countries on October 12. The watch suffered from significant shipping delays at the online Google Store.
Specifications
Design
Visually, the Pixel Watch 2 is near-identical to its predecessor, save a "slightly redesigned haptic crown". Six new families of watch faces were made available at launch. It is available in four case–band color pairs:
Hardware
The Pixel Watch 2 is made of recycled aluminum, a departure from the original Pixel Watch's stainless steel watch frame. Google stated that the change was made to make the watch lighter and more comfortable for users. It is powered by Qualcomm's Snapdragon SW5100 system-on-chip (SoC), a departure from its predecessor's Samsung Exynos chip. The watch's new circular sensor array consists of several new sensors. A multipath heart rate sensor boasts more accurate readings; a skin temperature sensor tracks sleep but not menstruation; while an electrodermal activity sensor detects sweat beads to assess the wearer's mood. The Pixel Watch 2 is not compatible with the first generation's proprietary magnetic charger, instead requiring a newer and faster one.
Software
The Pixel Watch 2 shipped with Wear OS 4.0. Like its predecessor, the watch features heavy Fitbit integration, given Google's acquisition of the company in 2021. New personal safety features include emergency location sharing, Safety Check, and Safety Signal.
Reception
In her review for The Verge, Victoria Song praised the Pixel Watch 2's improvements from the first-generation on all fronts, especially battery life, as did Yahoo! Finance reviewer Daniel Howley and Digital Spy reviewer Jason Murdock. Julian Chokkattu of Wired concurred, writing, "I get a watch that actually comes with everything I wish the original did out of the box. Hooray!" Matthew Miller of ZDNET highlighted the watch's deep Fitbit integration and safety features, but was ambivalent toward its small size. Will Greenwald of PCMag praised the watch's design, performance, and health features, while Mark Knapp of IGN called it "elegant and performant" but "still not a killer". CNN Underscored's Max Buondonno and TheStreet Jason Cipriani hailed its health, performance, and battery life enhancements. Writing for The Guardian, Samuel Gibbs appreciated the improved performance and battery life but was disappointed with the lack of advanced health features and ability to be repaired. Engadget Cherlynn Low was conflicted, commending Google's efforts to close the gap between other smartwatches but still finding it mediocre overall; Inverse Raymond Wong agreed, calling it "a better smartwatch, but not the best". Elizabeth de Luna of Mashable described the watch as "playing catch-up to the Apple Watch", while Robert Leedham of GQ thought it was the ideal smartwatch for those indifferent toward smartwatches.
References
External links
Made by Google 2023 (archived)
Computer-related introductions in 2023
Google hardware
Google Pixel
Smartwatches
Wear OS devices | Pixel Watch 2 | [
"Technology"
] | 859 | [
"Wear OS devices",
"Smartwatches"
] |
73,742,543 | https://en.wikipedia.org/wiki/Pixel%208 | The Pixel 8 and Pixel 8 Pro are a pair of Android smartphones designed, developed, and marketed by Google as part of the Google Pixel product line. They serve as the successors to the Pixel 7 and Pixel 7 Pro, respectively. Visually, the phones resemble their respective predecessors, with incremental upgrades to their displays and performance. Powered by the third-generation Google Tensor system-on-chip, Google placed heavy emphasis on their artificial intelligence–powered features, especially in the realm of generative AI and photo editing.
The Pixel 8 and Pixel 8 Pro were officially announced on October 4, 2023, at the annual Made by Google event and were released in the United States on October 12. They received generally positive reviews from critics, who praised both the hardware and software despite their modest upgrades. The phones' AI features, Google's historic promise of seven years of software updates, and the Pro model's unconventional inclusion of a temperature sensor received significant attention and was heavily scrutinized, drawing mixed reactions.
History
In May 2023, 9to5Google reported that Google intended to launch the Pixel 8 and Pixel 8 Pro in late 2023. The phones were approved by the Federal Communications Commission (FCC) in August of that year. After previewing the phones in September, Google officially announced the phones on October 4, alongside the Pixel Watch 2, at the annual Made by Google event. Pre-orders became available the same day, and the phones became available in 21 countries on October 12. Google hardware chief Rick Osterloh announced later that month that the company would begin manufacturing its Pixel phones in India beginning in 2024 with the Pixel 8, following Apple's lead with the iPhone 15 series. Bloomberg News reported that Dixon Technologies and Foxconn were among the top contenders for the job.
Specifications
Design
The Pixel 8 and Pixel 8 Pro are visually similar to the Pixel 7 and Pixel 7 Pro, respectively, with minor refinements such as a flatter screen, more rounded corners, and softer edges. The Pro model also features a matte finish. They were each available in three colors, with a fourth "Mint" color added in January 2024:
Hardware
The Pixel 8 has a FHD+ 1080p OLED display at 428 ppi with a pixel resolution and a 20:9 aspect ratio, while the Pixel 8 Pro has a QHD+ 1440p LTPO OLED display at 489 ppi with a pixel resolution and a 20:9 aspect ratio. The Pixel 8 has a variable refresh rate of 60–120 Hz, while the Pixel 8 Pro has variable refresh rate of 1–120 Hz. Both phones contain a wide and a ultrawide rear camera, with the Pixel 8 Pro featuring an additional 48 megapixel telephoto 5× optical zoom rear camera. The front camera on both phones contains a 10.5 megapixel ultrawide lens. As with the Pixel 7 series, the Face Unlock facial recognition system is enabled by software and the front camera, but adds support for secure biometric authentication.
The phones are powered by the third-generation Google Tensor system-on-chip (SoC), marketed as "Google Tensor G3", and the Titan M2 security co-processor. The OLED display, marketed as "Actua" and "Super Actua" on the Pixel 8 and Pixel 8 Pro, respectively, boasts "better color accuracy and higher brightness". The Pro model also features a temperature sensor on its rear camera bar, an unconventional feature for a smartphone. It was launched with its use on humans pending approval from the Food and Drug Administration. The Pixel 8 and Pixel 8 Pro were among the first phones on the market to support Wi-Fi 7, the latest wireless standard.
Software
The Pixel 8 and Pixel 8 Pro shipped with Android 14 at launch, coinciding with the stable release of Android 14 on the Android Open Source Project (AOSP), along with version 9.1 of the newly renamed Pixel Camera app. It will receive seven years of major OS upgrades, with support extending to 2030, a significant extension compared to previous generations that places the Pixel on par with Apple's typical support lifetime for iPhones. Google also stated that it would stock spare parts for the devices for seven years. Wired and The Verge noted that these two commitments were potentially linked to California's impending right to repair act requiring companies to provide support for devices costing $100 or more for seven years.
As with previous Pixel smartphones, artificial intelligence and software advancements took center stage during the Made by Google launch event. New camera features announced include Best Take, an upgraded Magic Eraser, Night Sight Video, Magic Editor, Audio Magic Eraser, and Real Tone on video. Exclusive to the Pixel 8 Pro were Video Boost and manual "Pro" camera controls, although the latter was only artificially restricted to the Pro model via software.
As part of Google's ongoing response to OpenAI's ChatGPT, Google also announced Assistant with Bard, a new version of the Google Assistant virtual assistant that integrates the company's recently introduced Bard chatbot. Other generative AI features included improved call screening, faster voice typing, grammar suggestions on Gboard, upgrades to the Recorder app, and a new magnifier app. The Pixel 8 Pro was touted as the first piece of hardware to run Google's generative AI large language models fully on-device, with Gemini Nano later being integrated into both models.
Marketing
On launch day, Google partnered with X Corp. to include an Easter egg on X, formerly known as Twitter, when users searched the hashtag #GooglePixel. In November 2023, Google set up a "Google Pixel Experience Space" pop-up store in Taiwan to showcase the Pixel 8 and Pixel 8 Pro. In continuation of Google's multi-year sponsorship of the NBA, the Pixel 8's "Built Different" advertising campaign spanned the NBA's 2023–2024 season. A series of commercials, produced in collaboration with Robot Agency, featured numerous NBA athletes and personalities such as Jimmy Butler, Giannis Antetokounmpo, Thanasis Antetokounmpo, Chiney Ogwumike, Flau'jae Johnson, Jamad Fiin, Chris Brickley, Cameron Look, Richard Jefferson, and Crissa Jackson. Google also collaborated with The New York Times to capture street-style video for the publication's "Style Outside" column.
To promote the introduction of the "Mint" color in January 2024, Google partnered with street artist Ricardo Gonzalez to paint over a Pixel 8 billboard in New York City. In February 2024, Google released a commercial titled "Javier in Frame" which advertised the Pixel 8's Guided Frame feature, ahead of its airing during Super Bowl LVIII. Directed by Adam Morse and telling the story of a blind man named Javier who uses Guided Frame to "document important moments in his life", the 60-second commercial marked Google's third Super Bowl spot in a row to market the Pixel.
Reception
Critical response
In early reactions, three aspects particularly piqued commentators' interest: the Pixel 8 Pro's temperature sensor, Google's promise of seven years of updates, and the heavy emphasis on AI. The temperature sensor drew varied reactions: some found it a potentially useful novelty, while others were bewildered and dismissed it as a strange gimmick. The response to Google's seven-year pledge was similarly divided: several journalists welcomed the move, hailing it as astonishing and monumental; others questioned whether Google would fulfill its promise.
The Washington Post Chris Velazco opined that the phones reflected "a deepening obsession with AI", with The Verge Jon Porter describing the launch event as "a parade of AI", observing that the phrase "AI" had been invoked over fifty times. As the Pixel 8 was "the first mainstream phone to bake generative AI directly into the photo creation process at no extra cost", computer science professor Ren Ng at the University of California, Berkeley described it as a pivotal milestone in the area of imagery. Nicole Nguyen of The Wall Street Journal raised concerns with the implications of the Pixel 8's photo editing features, fearing that it could lead to an influx in "fauxtography", the malicious manipulation of photographs. The AI features themselves received mixed responses. Writing for Wired, Julian Chokkattu expressed excitement that these features, hitherto limited to those proficient with image or video editing software, were now being made accessible to a wider audience; Ben Sin of XDA Developers found them "fun and scary". Porter felt that some of the features showcased were unnecessary, concluding that Google was continuing to attempt to reassert its position as a leader in AI after ChatGPT's meteoric rise earlier that year had caught Google executives off-guard. Also writing for The Verge, Allison Johnson described the features as "complicated and messy", while her colleague Jay Peters contemplated the question, "What is a photo?"
Reviews were largely positive, though Mashable observed a prevalent discontent with the phones' battery life, temperature sensor, and higher prices. Writing for The Guardian, Samuel Gibbs praised the phones' affordability and build quality, while Digital Spy Jason Murdock highlighted their cameras, performances, and displays. Chokkattu was thoroughly impressed by the phones' AI features, but was less pleased with the battery life and Face Unlock system. PCMag Iyaz Akhtar echoed these sentiments, while June Wan of ZDNET and Daniel Howley of Yahoo! Finance also emphasized the usefulness of AI. Marques Brownlee thought the phones were a mixed bag, finding the AI features a hit-or-miss. CNN Underscored reviewer Max Buondonno offered glowing praise of both phones. The Verge Allison Johnson was more skeptical, finding the AI features "useful [but] troubling", lamenting the higher prices, and questioning Google's seven-year-update promise. Mark Knapp of IGN appreciated the phones' modest hardware and performance upgrades, but felt they were inferior to Samsung's latest Android phones. Ron Amadeo of Ars Technica commended Google for abandoning curved screens in favor of a flat one, as well as praising its commitment to Tensor and software updates; however, he lambasted the Pro's temperature sensor as "embracing the worst of junky smartphone gimmicks". Forbes staff writer Rebecca Isaacs deemed the phones "a solid choice for casual users".
Commercial reception
Ryan Reith, an analyst at the International Data Group, predicted that Google could achieve higher sales numbers "if supported by strong marketing", considering its emphasis on AI. An opinion piece published in the Financial Times was headlined: "Price, not AI, will lift [the] Pixel's market share". Multiple publications have labeled the phones Google's latest subdued effort to compete with Apple's dominant iPhone sales.
References
Further reading
External links
Pixel 8
Pixel 8 Pro
Made by Google 2023 (archived)
Android (operating system) devices
Flagship smartphones
Google hardware
Google Pixel
Mobile phones introduced in 2023
Mobile phones with 4K video recording
Mobile phones with multiple rear cameras | Pixel 8 | [
"Technology"
] | 2,291 | [
"Flagship smartphones"
] |
73,742,783 | https://en.wikipedia.org/wiki/Cherry%20Hill%20%28model%20engineer%29 | Cherry Mavis Hill, MBE (née Hinds, 16 November 1931 – 4 December 2024) was an English model engineer known for her detailed scale models of steam vehicles. Hill won the Duke of Edinburgh award nine times, the Bradbury Winter Memorial Trophy eight times, and was awarded an MBE (Member of the British Empire) by the Queen of England, and other awards.
Life and work
Cherry Hill was born in Malvern, Worcestershire, England, on 16 November 1931. Her father, George Hinds, was an agricultural machinery manufacturer who began mentoring her when she showed enthusiasm for metalworking. In the Hinds household workshop, she learned machining skills and built her first models, including a scooter, warships, and aircraft. In that phase, Cherry received special mention for her Sunderland flying boat model in a model-making contest. While continuing her development as a model maker, she completed a BSC in maths at the University of St Andrews. During her 60-year model engineering career, Hill built nearly 20 detailed scale models of steam vehicles, including Victorian models, which each took her approximately 7,000 hours to make. The parts in the models were all made from her metal stock, and the engines are fully operational. Additionally, her engines were made from scratch, every nut and bolt was made in her workshop, and a complete model took 7 years to make. Cherry Hill is considered to be one of the greatest model engineers ever due to her success in competitions.
An article written about her by the Craftsmanship Museum says that, "The uncompromising craftsmanship exhibited in Cherry’s work is a result of her attitude. She never accepts anything less than perfection." As her career progressed past its early stages, Hill started building unusual models, many of which were insufficiently documented or had no existing original copies. Due to the scarce information frequently taken from patent applications, Hill often had to use her design skills to overcome missing information and shortcomings in the original designs in order to make fully functioning models. Her favorite model was the Blackburn agricultural engine of 1863. Hill needed to be resourceful and imaginative in various critical components, including the crankshaft, valve chest and eccentrics, boiler, steering, and front suspension. The models made at the beginning of Hill's career were given to family and friends, but she donated her more recent ones to the Institution of Mechanical Engineers.
In addition to her acclaimed work as a model engineer, Cherry Hill also worked as a machinery designer for her family business McConnell-Hinds who made innovative hop-picking machinery. Cherry was also an inventor and had had several patents awarded to her, including the well known Crypton Synchro-check carburettor balancer (produced commercially by AC Delco), an air flowmeter device used for setting and balancing multiple carburettors on car and motorcycle engines. An expert on obscure 19th-century engineers, Hill explained that ‘Everyone has heard of Brunel and Stephenson, but there were a lot of very clever people in the background. I'm just interested in these people and how they thought about engineering.’
Models
In the 1950s, Cherrie Hill began working on the Stuart Turner No 9 early 20th-century steam engine. She was ‘thrilled to bits’ after 18 months of work because she achieved her goal of getting the engine to work. The model won her a bronze medal at the International Model Engineering Exhibition. After that, she built an Allchin Royal Chester traction engine. Thanks to her father's suggestion, the model was built in a scale of 1:16, which was important because it became the scale she used in later models. The model won her a silver medal at the exhibition. However, Hill wasn’t satisfied and spent 7 years improving it after locating the full-size machine near Tonbridge, England. Later, she built a Stuart D10, a Burrell showman’s engine, and a red 1905 Merryweather fire engine, which got her on the cover of Model Engineer magazine along with the Allchin, increasing Hill’s recognition among model engineering enthusiasts. These were praised due to their obscurity, complexity, difficulty, and rarity.
Cherry Hill’s Blackburn agricultural engine of 1857 was a model based on a design made when traction engines were in their early development, and many were impractical. The plans for the Blackburn were insufficient, so Hill had to create her own design to make it work. That model won a gold medal at the Bradbury Winter Memorial Trophy and a Duke of Edinburgh’s Award. Another exceptional model was the 1862 Gilletts & Allatt traction engine, partly because Hill designed and patented her own traction engine. It also won a gold medal, a Bradbury Winter Memorial Trophy, and The Duke of Edinburgh’s Award. A notable project of Cherry’s later years is the Nathaniel Grew ice locomotive, which was used in Russia to carry cargo across frozen lakes and rivers in the 1860s. It is made completely from steel, and the sled blades were constructed using conventional machining rather than CNC. Many of Cherry Hill’s award-winning models are exhibited at the Institution of Mechanical Engineers in London, England.
Personal life
Ivor Hill, also a model engineer, first saw Cherry on the cover of the 1968 Model Engineer magazine; he was so enamored that he declared, ‘I’m going to marry that girl’. He successfully courted her, and they were married and lived in the U.S. until his death. Cherry Hill died in Malvern on 4 December 2024, at the age of 93. She was survived by her sisters, Charmian and Rosalie, as well as their children.
Awards
Sir Henry Royce Trophy for the Pursuit of Excellence (1989 and 1995).
MBE (Member of the British Empire) award (2000).
Elected Companion of the Institution of Mechanical Engineers (2004).
Honorary member of the Society of Model and Experimental Engineers (2004).
Awarded nine different gold medals at the annual Model Engineer Exhibition in London.
Awarded the Bradbury Winter Memorial Trophy eight times.
Awarded the Aveling Barford Cup twice.
Crebbin Memorial Trophy.
Awarded the Championship Cup three times.
Awarded The Duke of Edinburgh's Award nine times.
Joe Martin Foundation Craftsman of the Year Award (2017).
References
External links
The Remarkable Mechanical Models of Cherry Hill
1931 births
2024 deaths
Alumni of the University of St Andrews
Model makers
Model engineers
People from Malvern, Worcestershire
Members of the Order of the British Empire | Cherry Hill (model engineer) | [
"Physics"
] | 1,317 | [
"Model makers"
] |
73,742,916 | https://en.wikipedia.org/wiki/Luisa%20Verdoliva | Annalisa (Luisa) Verdoliva (born 1972) is an Italian engineer whose research concerns image processing and digital forensics of multimedia data, including the detection of deepfakes and other AI-generated imagery. She is a professor in the Department of Industrial Engineering at the University of Naples Federico II, where she directs the Multimedia Forensics Lab.
Verdoliva was born in 1972, and earned a laurea in telecommunications engineering from the University of Naples Federico II. She chaired the IEEE Information Forensics and Security Technical Committee from 2021 to 2022, and was named to a government task force on fake news in 2020.
She was named an IEEE Fellow, in the 2021 class of fellows, "for contribution to multimedia forensics".
References
External links
Home page
1972 births
Living people
Italian engineers
Italian women engineers
Telecommunications engineers
University of Naples Federico II alumni
Academic staff of the University of Naples Federico II
Fellows of the IEEE | Luisa Verdoliva | [
"Engineering"
] | 188 | [
"Telecommunications engineering",
"Telecommunications engineers"
] |
73,743,242 | https://en.wikipedia.org/wiki/Mass%20media%20use%20by%20the%20Islamic%20State | IS is known for its extensive and effective use of propaganda. It uses a version of the Muslim Black Standard flag and developed an emblem which has clear symbolic meaning in the Muslim world.
Videos by IS are commonly accompanied by nasheeds (chants), notable examples being the chant Dawlat al-Islami Qamat, which came to be viewed as an unofficial anthem of IS, and Salil al-Sawarim.
Traditional media
Al-Furqan Foundation for Media Production
In November 2006, shortly after the group's rebranding as the "Islamic State of Iraq", it established the Al-Furqan Foundation for Media Production (), which produces CDs, DVDs, posters, pamphlets, and web-related propaganda products and official statements. It is the primary media production house of the Islamic State and responsible for production of major media releases, including the statements of the spokesman and leader of the group.
It was founded by the Iraqi man Dr Wa'il al-Fayad, known as Abu Muhammad al-Furqan. He got his name "al-Furqan" from his role in founding this media house, which was named after the 25th sura of the Quran Al-Furqan. It is the oldest media production house for the Islamic State, being founded in November 2006 to release media for the Islamic State of Iraq. The earliest release indexed by the SITE Intelligence Group is on 21 November 2006, documenting the storming of a police station in the Iraqi town of Miqdadiyah.
Al-Furqan is considered to be a considerable innovation in jihadist media, with Kavkaz Center describing it as "a milestone on the path of jihad, a distinguished media that takes the great care in the management of the conflict with the crusaders and their tails and to expose the lies in the crusader's media."
In October 2007, the Long War Journal reported on United States Army raids targeting al-Furqan media cell members across Iraq, including in Mosul and Samarra. Between August 2013 and March 2014 they released the 22 part series Messages from the Land of Epic Battles. On 2 September 2014 SITE Intelligence Group discovered the beheading video called A Second Message to America, about the death of Steven Sotloff.
Since then, Al-Furqan has released videos of their operations across Iraq and Syria, as well as execution videos directed to governments around the world. In April 2019, Al-Furqan released a video Interviewing Abu Bakr al-Baghdadi, which is their last video as of today.
Al-Furqan also produces media in the form of audio, which consists mostly of recordings of IS leaders and spokesmen giving speeches, as well as producing a single nasheed under their name called "Ya Allah Al-Jannah" (O Allah, (we ask you for) Paradise), sung by now-dead member of IS, Uqab Al-Marzuqi.
Ajnad Foundation for Media Production
It began to expand its media presence in 2013 with the formation in March of a second media wing, Al-I'tisam Media Foundation, and another IS media foundation, the Ajnad Foundation for Media Production (; muasasat ajnād lil'īntāj al'ilāmī), established in January 2014, which specialises in acoustics production for nasheeds with no music, as to adhering to the prohibition of music instruments in Islam, and Qur'anic recitation.
The organization notably starts its career around in August 20, 2013, when the Islamic State started gaining territory. After Al-Furqan used the nasheed "Ya Dawlatal Islam, Ya Dawlatal Iqdam" as the sole intro for its 22-part series, the famous nasheed "Ummati Qad Laha Fajrun", one of the first nasheeds made by the Ajnad Foundation appeared in the last 2 parts of the series. Later on, the nasheed "Ya Dawlatal Islam, Ya Dawlatal Iqdam" would be recorded once again by Ajnad, featuring a brand-new melody and minor alteration of the original lyrics, as well as being sung by Maher Meshaal.
Ajnad Foundation would once again rise to fame when Al-Furqan released Saleel As-Sawarim 4 in 2014, which documents IS operations in Iraq and Syria, as well as premiering the famous nasheed Saleel As-Sawarim. Another nasheed, called Qariban Qariba (Soon, Soon) would be released, often played alongside the group’s more unusual executions, including the burning of a Jordanian pilot, the burning of a Turkish and a Kurdish soldier, an execution where several prisoners of war were put into a car then shot with a rocket, and another execution where several prisoners would be drowned in a cage. Since then, more famous nasheeds would be released by Ajnad until its hiatus during 2020, when the last known nasheed released by then is "Gharibun Dammani Sha'uthul-Bawadi".
In the beginning, munshideen (singers) like Al-Mo'taz bil-'Aziz sang for the foundation. Uqab Al-Marzuqi sang 3 nasheeds, 2 recorded under Ajnad and another under Al-Furqan. After his death, Ajnad released a nasheed to commemorate him.
Some of the known later Ajnad munshideen (singers) are Abu Yasser, who produced more than 40 nasheeds under the labels of Al-Ma'sadah, As-Siddiq, Masami' Al-Khayr Media Centre(s) (all affiliated with Al-Qaeda) and Ajnad Foundation. Khilad Al-Qahtani is also a symbol for Ajnad, as he produced more than 10 nasheeds which is frequently used by IS media centers, as well as getting the honor of being mentioned by Abu Bakr Al-Baghdadi in an interview with Al-Furqan Media Production. Maher Meshaal is another Internet-famous munshid who emigrated to the Islamic State from Saudi Arabia in 2013, and sang for Ajnad until his killing in 2015. Abul Hasan Al-Muhajir also was a munshid and the narrator for most Ajnad intros; as with other organizations, before he was promoted to spokesman of the Islamic State. Abu Hamzah al-Qurashi, the spokesman for the Islamic State until his demise in 2021 also produced around 15 nashids during his Ajnad career. Others like Abu Ghuraba' Al-Yamani, Abu Bara' Al-Madani, Nimr Al-Muhajir and others are also IS members that emigrated and joined the organization; though their career is not as famed as other munshids. As of now, some of the munshids still remain anonymous to this day.
Ajnad Foundation also produces full Qur'an recitations, which are recited by Abul-Hasan al-Hasani, Abu 'A'ishah, and other unknown people. They have produced 114 Surahs in the recitation of Hafs 'An Asim, and Surah Al-Ra'd in Warsh 'An Nafi'.
On 4 May 2016 Al-Battar Foundation (IS-supporter media) launched an application on Android called "Ajnad" that allows its users to listen to the songs of the Ajnad Foundation on their mobile phones. The foundation has many singers, the most famous of whom are Abu Yasir and Abul-Hasan al-Muhajir.
al-Hayat Media Center
In mid-2014, ISIL established the al-Hayat Media Center, which targets Western audiences and produces material in English, German, Russian, Urdu, Indonesian, Turkish, Bengali, Chinese, Bosnian, Kurdish, Uyghur, and French. When ISIL announced its expansion to other countries in November 2014 it established media departments for the new branches, and its media apparatus ensured that the new branches follow the same models it uses in Iraq and Syria. Then FBI Director James Comey said that ISIL's "propaganda is unusually slick," noting that, "They are broadcasting... in something like 23 languages".
In July 2014, al-Hayat began publishing a digital magazine called Dabiq, in a number of different languages including English. According to the magazine, its name is taken from the town of Dabiq in northern Syria, which is mentioned in a hadith about Armageddon. Al-Hayat also began publishing other digital magazines, including the Turkish language Konstantiniyye, the Ottoman word for Istanbul, the French language Dar al-Islam, and the Russian language Istok (). By late 2016, these magazines had apparently all been discontinued, with Al-Hayat's material being consolidated into a new magazine called Rumiyah (Arabic for Rome).
Asdaa Foundation
Like the Ajnad Foundation, the Asdaa Foundation () or Asedaa Foundation also produces Anasheed (Islamic chants). Some of their Anasheed is used in IS's execution videos, a popular one is their human slaughterhouse execution video released during the time of Eid Al-Adha in 2016. The background nasheed they used was "We Came To Spread Terror Everywhere", produced by the Asdaa Foundation.
The foundation is the closest counterpart to Ajnad in producing Islamic State nasheeds, only difference being Ajnad is directly linked to the Islamic State while Asdaa is only classified as a "supporter organization" (munaser/munasera). One of its munshids, Abu Hafs is a renowned munshid who sings around 70 nasheeds, who as well works with Ajnad Foundation in some instances.
Another Yemeni munshid, Abu Musab Al-Adani, worked temporarily with Asdaa Foundation before defecting back to AQAP, from which he previously defected from.
al-Azaim Foundation for Media Production
al-Azaim Foundation for Media Production, run by Islamic State in Khorasan Province, publishes Voice of Khorasan magazine, which covers political and religious topics and also attempts to recruit and incite followers to carry out attacks (anti-Taliban narratives). Islamic State in Hind Province (Hind Wilayah) publishes Voice of Hind magazine, propaganda which encourages Indian Muslims to be recruited and wage jihad, and carry out attacks in the country. It was first published in 2020, and it also supports global warfare against Taliban in Afghanistan.
I'lam Foundation
I'lam Foundation, announced in 2018, is an online multilingual platform mostly used by the Islamic Movement of Uzbekistan, specifically the Tajikistan region of the organization, and the IS–K. In May 2021 it launched al-Hijrateyn, a weekly podcast which presents news, statistics and commentary from the Al-Naba newsletter, it focuses on solutions to moral dilemmas as interpreted by the Islamic State.
IS, in a mid-March 2020 Al-Naba article, described the fearful reaction to COVID-19 as a divinely wrought "painful torment" against Western "crusader nations". An early February article praised God for the same against Iran's Shiites and China.
Along with Fahras and al-Ru'ud (al-Raud Media Archive), these propaganda repositories connected with channels designed to lure online audiences to hotspots of pro-IS communication, a method of designing and maintaining propaganda distribution networks.
At-Taqwa Media Foundation
At-Taqwa Media Foundation is an IS-sympathizer/supporter outlet which has published about targeting attacks in the Arabian Peninsula and specifically during the 2022 FIFA World Cup.
Networks
The group also runs a radio network called Al-Bayan, which airs bulletins in Arabic, Russian and English and provides coverage of its activities in Iraq, Syria and Libya. Huroof is an app created by the Office of Zeal, an Islamic State controlled agency, in order to teach kids Arabic, and to recruit young children into becoming Islamic State soldiers.
Social media
IS's use of social media has been described by one expert as "probably more sophisticated than [that of] most US companies". It regularly uses social media, particularly Twitter, to distribute its messages. The group uses the encrypted instant messaging service Telegram to disseminate images, videos and updates.
The group is known for releasing videos and photographs of executions of prisoners, whether beheadings, bombings, shootings, caged prisoners being burnt alive or submerged gradually until drowned. Journalist Abdel Bari Atwan described IS's media content as part of a "systematically applied policy". The escalating violence of its killings "guarantees" the attention of the media and public.
Along with images of brutality, IS presents itself as "an emotionally attractive place where people 'belong', where everyone is a 'brother' or 'sister'". The "most potent psychological pitch" of IS media is the promise of heavenly reward to dead jihadist fighters. Frequently posted in their media are dead jihadists' smiling faces, the Muslim 'salute' of a 'right-hand index finger pointing heavenward' (pointiong towards where Allah is), and testimonies of happy widows. IS has also attempted to present a more "rational argument" in a series of videos hosted by the kidnapped journalist John Cantlie. In one video, various current and former US officials were quoted, such as the then US President Barack Obama and former CIA Officer Michael Scheuer.
It has encouraged sympathisers to initiate vehicle-ramming and attacks worldwide.
References
Mass media issues
Media bias | Mass media use by the Islamic State | [
"Technology"
] | 2,827 | [
"Computing and society",
"Social media"
] |
73,744,261 | https://en.wikipedia.org/wiki/Actinomucor%20elegans | Actinomucor elegans was originally described by Schostakowitsch in Siberia in 1898 and reevaluated by Benjamin and Hesseltine in 1957. Commonly found in soil and used for the commercial production of tofu and other products made by soy fermentation. Its major identifying features are its spine-like projections on the sporangiophore and its ribbon-like hyphal structure when found in the tissue of a host.
Taxonomy
The Actinomucor genus has many shared similarities with the genus Mucor. The specific differences lie in the branched hyphae of Actinomucor that give rise to rhizoids and sporangiophores. In terms of its differences from other similar genera, the limited growth of hyphae and the variation in the structure of columella and sporangiophores give Actinomucor multiple differentiable characteristics to other genera.
Morphology
Mycelial growths of A. elegans have a high number of rhizoids branching out of each individual growth. On portions of growth that lack opposite rhizoids, aseptate hyphal growths with clear sporangiophores that are found with extreme variability in length and width. These hyphal structures grow out in whorled structures with growth terminating in the development of sporangiophores. The sporangia are oval to spherical in shape and 17–50 μm in diameter. The walls of the sporangia possess prominent spine-like projections, which is a major identifier of this specific fungus. The coloration of colonies of this fungi is white to cream-colored with an abundance of aerial mycelium. Cultures allowed to develop for a longer period of time (greater than 48 hours) change to become yellowish to buff color with increased aerial mycelium development and tight interweaving of these mycelia. When this fungus is found in a human host the structure is explained to be similar to the genus Mucor, but with unique ribbon-like hyphal structures and irregular branching and thickness.
Human pathogen
Identified as an arising human fungal pathogen the recorded instances of mucormycosis due to A. elegans are limited to four cases. The invasion mechanisms found for A. elegans are through spore inhalation or entry from ruptures in the skin. This pathogen is highly-deadly when found in an immunocompromised individual, and can develop into a serious infection for immunocompetent individuals as well. Immunocompromised patients are affected worse by infection due to their immune system being unable to stop the germination of fungal spores resulting in there being no mechanism to slow the colonization once this pathogen is introduced. In all cases involving immunocompromised individuals, the relatively large visible location of necrosis seemed to be the first indicator of an invasion. It is thought that these necrotic areas are indicative of the place on the body in which inoculation occurred. A. elegans as a pathogen is categorized as a mucormycosis-causing fungus, and because of this, the current leading treatment for this type of pathogen is the removal of necrotic tissue in an effort to remove the fungal elements from the body. The severity of infection from A. elegans is due to its propensity for invasion of the vascular system and hematogenous dispersion ultimately leading to necrosis of tissue. To limit the suffering, discomfort, or expiration of a patient infected with this pathogen an early suspicion of this specific fungi needs to be established. Early identification is important as it limits the time for the fungi to colonize the host before doctors can gather infected tissue to isolate and culture the fungi to confirm its presence in the patient. Because of this pathogen's relative rarity, the time required to correctly identify the pathogen is usually not rapid enough resulting in high mortality rates of individuals infected.
Fermentation of food products
Tofu
Mold fermentation in the production of tofu utilizes A. elegans. Through fermentation, A. elegans breaks down large macromolecules and converts them into simple fatty acids, amino acids, or sugars resulting in increased digestibility for humans. Ultimately increasing the functional and nutritional properties of tofu.
Sufu
Another use of A. elegans is for the fermentation processing of sufu pehtze. A. elegans is specifically proficient for the production because it possesses important enzymes for the fermentation process and results in nutritional improvements of the food. Specific enzymes that add marketable aspects to this product include glutaminase which increases palatability, and α-galactosidase which reduces flatulence in people consuming the product.
Debittering soy protein hydrolysates
Actinomucor elegans is utilized for its debittering ability as well. Protein hydrolysates, such as whey and casein protein mixes all utilize proteolytic enzyme treatment to achieve heightened nutritional value, but paired with these nutritional improvements commonly comes a bitter taste. The bitter taste results from the amount and structure of hydrophobic amino acids formed in peptides. When paired with alcalase, A. elegans results in increased hydrolysis of amino acids in protein hydrolysates. Specifically, this hydrolysis occurs by A. elegans acting as an exopeptidase increasing the rate of hydrolysis resulting in a decrease of bitterness.
Plastic degradation
To combat the white pollution caused by worldwide plastic waste many biodegradable products are now made out of polylactic acids (PLA) or polybutylene adipate-co-terephthalate (PBAT). Lipases secreted by A. elegans were found to be the second most proficient at expediting the full breakdown of these compounds. When a coculture of the most proficient dissolver of these compounds Pseudomonas mendocina and the second-most proficient A. elegans it resulted in a substantially higher degradation rate than either fungus could achieve individually. In the observed physical structure of this relationship, it was found that P. mendocina was attached to the mycelia of A. elegans. This synergy resulted in a higher degradation rate because A. elegans possesses a large hyphal network resulting in larger colonization of the molecule, which increased the number of colonization sites for P. mendocina resulting in the superior degrading of the molecule. From a biochemical standpoint, the degradation occurred because the lipases of A. elegans and the proteases of P. mendocina catalyzed the ester bonds of the PLA/PBAT molecules. This finding shows that there is an efficient added degradation mechanism available to be employed if products formed out of PBAT/PLA become more widespread lowering the chances for waste buildup and decreasing the harmful effect of plastics in the environment by having the ability for its full degradation to be done quickly.
References
Mucoraceae
Fungus species | Actinomucor elegans | [
"Biology"
] | 1,452 | [
"Fungi",
"Fungus species"
] |
73,745,018 | https://en.wikipedia.org/wiki/Rhenium%20tetraiodide | Rhenium tetraiodide is a binary chemical compound of rhenium and iodide with the chemical formula .
Synthesis
Rhenium tetraiodide can be obtained via the reduction of perrhenic acid with hydrogen iodide:
Physical properties
Rhenium tetraiodide forms black solid substance which is soluble in acetone and ether. Hydrolyzed by water, hygroscopic.
Chemical properties
Rhenium tetraiodide is hydrolyzed by water:
Rhenium tetraiodide decomposes when heated:
References
Rhenium(IV) compounds
Iodides | Rhenium tetraiodide | [
"Chemistry"
] | 132 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
73,745,644 | https://en.wikipedia.org/wiki/Massive%20precut%20stone | Massive-precut stone is a modern stonemasonry method of building with load-bearing stone. Precut stone is a DFMA construction method that uses large machine-cut dimension stone blocks with precisely defined dimensions to rapidly assemble buildings in which stone is used as a major or the sole load-bearing material.
A key technique of massive-precut stone ("MP stone") is to specify precut stone to precise dimensions that match the architect's plan for rapid construction, typically using a crane. The blocks may be numbered so that the masons can follow the plan procedurally. The use of massive stone blocks has several benefits, listed below.
Massive-precut stone construction was originally developed by Fernand Pouillon in postwar period who referred to the method as "pierre de taille" or "pré-taille" stone. It became possible through innovations by Pouillon and Paul Marcerou, a masonry engineer at a quarry in Fontvieille, to adapt high-precision saws from the timber industry to quarrying and stone sawing.
Massive-precut stone is also known as "prefabricated stone", "pre-sized stone", "megalithic" construction, "massive stone", or simply "mass stone". However these terms have various namespace conflicts with other stonemasonry techniques like synthetic stone, cosmetic (non-loadbearing) precut stone, and/or older methods of massive handworked stonemasonry. MP stone has a close affiliation with tensioned stone as compatible methods of modern load-bearing stonemasonry. Similarly, massive-precut stone (aka mass stone) has a connection to mass timber as allied low-carbon construction methods using traditional structural materials in a new context.
Since 1948, MP stone buildings have been constructed in France, Algeria, Iran, Switzerland, Palestine, United Kingdom, Spain, and India. The re-adoption of MP stone inspired architecture critic Rowan Moore to speculate that "It's conceivable, indeed, that the era of concrete will prove only an interlude in the far longer history of stone."
Design features of massive-precut stone
MP stone is defined by five design attributes. These differentiate MP stone from both traditional stonemasonry and modern non-load-bearing and/or non-DFMA stone methods.
Load bearing. This distinguishes MP stone from cosmetic precut stone, which is used for cladding decoration.
Massive blocks. Using massive dimensions has three critical benefits: (1) minimizing cuts, which lowers cost and shortens production time, (2) increases the thermal mass of walls for temperature regulation in the building, and (3) makes use of crane construction, thereby lowering manual labor, shortening assembly time, reducing mortar, labor, and cost.
Precise offsite dimension cuts. Precutting can be done at the quarry, or at a masonry workshop by sawyer and banker masons. The precision amounts to a form of prefabrication, such that the masons do not have to make adjustments onsite, and construction is an assembly process. Precise interfaces also reduce the amount of mortar required.
Machine fabrication and assembly. Unlike traditional stonemasonry, cutting (saws) and assembly (cranes) is primarily done with machines.
Design for manufacturing and assembly. The architect will design the building to specify each ashlar's dimensions. Blocks are to be designed to be as modular as possible, ideally with a handful of different shapes. Reducing the types of shape simplifies manufacture. Pouillon was able to build large housing projects faster and cheaper than the competition, in part due to his DFMA process. "Exactly how Pouillon brought the 2,635 apartments of the 1959 Résidence du Parc in Meudon-la-Forêt (1959) online in record time and at less-than-market prices remains a mystery no-one seems to want to see solved." – Graham McKay.
Types of massive-precut stone construction
There are three implementations of massive-precut stone.
Massive-precut monolithic ashlars. Blocks cut precisely on four to six sides, used to assemble walls, lintels over windows and doors, and in flat arches. The first major use of this variation was in the La Tourette and Vieux-Port redevelopment projects.
End-shaped massive-precut monoliths. Quarry-finished dimension stone blocks with precisely shaped ends for assembly into post-and-lintel frameworks. The first implementation of this method was in the 15 Clerkenwell Close building, completed 2017.
Massive-precut cyclopean concrete blocks. Developed by IBAVI in Mallorca, rough stones are placed in a mold and saturated with concrete. The concrete is sawn into massive ashlars for crane assembly. Enables reuse of rough plum stones from traditional stone masonry. The first documented architectural use of precut cyclopean concrete blocks was in a social housing project on Mallorca in the early 2020s.
Tensioned stone. Stone beams and columns can be strengthened by drilling a duct that is threaded with a tension cable. After assembly with grout, the cables are tensioned using standard pre-stressing jacks. Both pre- and post tensioned stone can be used.
MP stone is typically used in conjunction with other materials, notably for floors, as unreinforced stone is unsuitable for tensile spans. It has most often been used together with reinforced concrete floors, but plans are in place to use it with cross-laminated timber floors, and post-tensioned stone floors. Reinforcing massive precut stone with post-tensioning reinforcement would make it strong enough to substitute for reinforced concrete in a wide range of applications.
In 2024, UK industry group the Stone Collective formed to promote construction with stone, and advance education in this area.
Benefits of massive-precut stone construction
MP stone construction has five key advantages over non-massive stone and brick masonry, concrete, wood, and other conventional construction methods.
Specific benefits of massive-precut stone construction
Build speed. The use of precisely cut and numbered ashlars, combined with crane-assisted assembly, significantly reduces construction time compared to traditional stone masonry techniques. Compared to concrete construction, MP stone is faster as there is only a limited setting wait time.
Simplicity. Amin Taha compares a stone-clad concrete column with a stone column. The former demands multiple layers: steel, concrete, fireproofing, waterproofing, stone cladding, and the fixtures connecting them; all require the various specialized workers for installation. The latter is a block of stone that is installed by masons using a crane and mortar.
Design efficiency. Simplicity improves design efficiency, enabling architects to generate and iterate building designs quickly. Use of DFMA and modularity improves the chance of project success.
Labor Efficiency. The use of cranes and a well-organized construction plan reduces the labor required, lowering costs and reducing the wait time for skilled mason availability.
Cost reduction. Compared to brick masonry or smaller ashlars, using larger stone blocks (and thereby minimizing sawing and fixer-masonry costs,) means that the overall expense of constructing a building can be reduced.
General advantages of stone construction
Environmental Benefits. The use of a material with lower embedded carbon contributes to a more sustainable building process, minimizing the environmental impact. Lower carbon emissions: load-bearing stone construction emits around 1/10th the carbon as a comparable concrete building. As 80% of energy is non-grid fossil fuel, and construction is respoinsible for 8% of carbon emissions, the replacement of coal-burning concrete production with lower-energy dimension-stone production could have a substantial impact on net-zero goals. "Imagine: we currently crush, burn and chemically mix limestone to make cement for concrete that then has 40 per cent of the strength of its original strength, needing steel to reinforce it. Why do we use concrete then?"
Durability. Buildings constructed using massive precut stone maintain the inherent durability and longevity of stone construction, offering long-lasting and low-maintenance structures. Historically, load-bearing stone is the most durable construction method. An engineering analysis of a 20-storey unreinforced MP-stone tower has suggested this method has good seismic resilience: "With regard to the current Algerian seismic design regulation, the results obtained in terms of time period, frequency, storey drifts and displacements showed that the… [Diar Es Saada massive precut stone]… tower can be considered as an earthquake-resistant building fulfilling the required structural safety conditions."
Aesthetics. Compared to concrete and other materials, massive precut stone construction yields visually striking and distinctive buildings that showcase the natural beauty of stone. There is a trend away from artificial stone products due to their fake image. “People increasingly want the authentic beauty and inconsistencies of natural stone; imitation ceramic tiles include realistic veins but have a repeat pattern like wallpapers, so you can tell quickly that they're fake.”
Reusability. When a building has reached the end of its usefulness, rectilinear ashlars are easily reused as spolia in new construction.
Thermal Performance. As with traditional stone construction, massive precut stone buildings benefit from excellent thermal mass, helping to regulate indoor temperatures and reduce energy consumption for heating and cooling.
Fire resistance. Compared to wood and other products, stone has far superior fire resistance, so requires little or no additional fireproofing.
Controversies around massive-precut stone
MP stone has been ignored and/or resisted by mainstream architects, engineers, and developers.
Belief that dimension stone is too expensive for non-luxury load-bearing construction. Depending on the context, this may be true if quarries are not developed for large precision blocks. However, in the early 2020s quarries in France and Italy were able to furnish cost-effective precision-cut stone. Amin Taha of Groupwork points out that using stone directly obviates the use of fireproofing, waterproofing, stone (or other) cladding, associated fixtures, and cuts labor costs, while simplifying design and design iterations.
Claim that MP stone cannot be safely used for tall structures. This view is contradicted by two 70-yo towers standing >50 m, located at 2 Rue Saint Laurent, Marseille; and Diar Es Saada, Algiers, the latter of which is close to a fault. Also the stone towers of cathedrals that have lasted for centuries, and ancient tall stone structures—like the 48-m Pont du Gard—that have stood for millennia.
Unsuitability of MP stone for long spans, including floors. Due to its poor tensile strength, stone cannot be used for long spans, so (unlike reinforced concrete), architects and builders must switch modes during design and construction of horizontal and vertical components. MP stone can be used in conjunction with concrete floors, manufactured timber panels, and post-tensioned stone flooring units.
The mainstream modernists, who were focused on concrete, steel, and other new materials, disliked the continuity with the old world that MP stone represented. This disregard for stone in fact violated Louis Sullivan's maxim that "form follows function".
Following the construction of 15 Clerkenwell Close, the quarry finishes on the blocks was opposed by a local councilmember due to claims about heritage style and aesthetics. Ironically the use of load-bearing rusticated stone is an ancient style and the use of limestone was specifically appropriate to the site, which was the site of a limestone Norman abbey.
In many nations, quarries produce aggregate, and/or dimension stone is only produced for cosmetic veneers, not structural purposes. This means that the most abundant natural construction resource is inaccessible to most of the world's population. This explains why the method has been used most extensively in France, where the quarrymasters and other stonemasons are knowledgeable in load-bearing stone. The presence of heritage stonemasons in many regions suggests that there is the potential to restore structural stonemasonry in many countries.
There is the perception that stone quarries are destructive to the environment. This position ignores the fact that concrete and steel each require multiple quarries and mines, along with intensive carbon release due to extraction and heating.
History of massive-precut stone
The history of construction with stone goes back thousands of years, to before the age of the pyramids, however these constructions used muscle energy to cut stones, typically with considerable fixer stonemasonry on site. In modern architecture, stone had been used in a number of contexts, even prior to the development of the massive-precut method.
In the 19th Century, architect Louis Sullivan used load-bearing stone walls in the Auditorium Building (1889) in Chicago. In the 20th century, most modern architects pivoted to steel and concrete construction. Nevertheless, even modernists used load-bearing stone in some projects, e.g. Le Corbusier included stone walls in Villa de Mandrot (1931), Maison Henfel (1934), and Villa Le Sextant (1935). Some of the Prairie School architects, including Frank Lloyd Wright, used stone in houses. Wright houses that use stone include Fallingwater (1935), the Mrs. Clinton Walker House, and his own houses Taliesin (1925) and Taliesin West (1937). Another Prairie-School architect, Walter Burley Griffin, used stone in the Joshua Melson house (1912) and site-quarried, load-bearing sandstone in his Castlecrag suburban development (from 1922), a technique that aimed to enable the mass production of housing from the local Sydney bedrock.
After these efforts to include stone into modern construction, the large-scale use of massive precut stone was pioneered by Fernand Pouillon (1912-1986), a French architect who was active in post-war reconstruction. Starting in the 1940s, his innovative approach to stone led to the development of numerous noteworthy projects, with a particular focus on apartment complexes. Throughout his long career, Pouillon played a crucial role in the development and popularization of massive precut stone construction techniques. His pioneering work laid the foundation for subsequent architects to build upon and innovate, leading to the resurgence and expansion of this construction method in modern architecture.
MP stone in the 20th century: Pouillon
Fernand Pouillon, French Wikipedia
In the post-war era, Pouillon—first in Auguste Perret's firm and then through his own office—designed and completed MP-stone buildings that held tens of thousands of apartments, in France and Algeria. In post-war France, there was a huge demand for new urban housing, but cement and steel were relatively expensive; machine-cut limestone represented a plentiful, economical building material.
Mid-century precut stone. Precut stone for modern architecture was pioneered by Fernand Pouillon in the post-war period in France, Algeria, and Iran. The method was made possible by a collaboration with Paul Marcerou, a masonry engineer at a quarry in Fontvieille "This new technique consisted of adapting machines used to form steel and wood to cut stone. As a result of this technique it became possible to mine and shape the blocks of the Fontvielle quarry very finely, which allowed for a particular building technique, named ‘ready-made’ or ‘prefabricated’ stone by Pouillon.".
1940s: Pouillon began experimenting with the use of machines to cut stone, adapting technologies initially designed for steel and wood processing. This new technique enabled the precise shaping of stone blocks from the Fontvielle quarry. The signature development from this time was the design and construction of La Tourette in the reconstruction of the Vieux-Port of Marseille, in collaboration with André Devin, Eugène Beaudoin, and Auguste Perret. A landmark development in this project was the construction of the first MP stone skyscraper, 2 Rue Saint-Laurent, a 16-storey apartment building.
1950s: Pouillon designed and constructed various housing projects in France using his prefabricated stone technique, such as the Meissonier housing project in Aix-en-Provence, which showcased the speed and efficiency of his construction method. He worked in Paris, building several large housing developments of architectural merit.
Algeria, 1950s-1970s: Pouillon was invited by the colonial government to bring his work to Algeria, to address their housing crisis. He designed several major housing projects in Algiers, such as Diar es-Saâda (730 units), Diar el Mahçoul (900 units) and Climat de France (3500 units), that latter of which was "the backdrop of the concluding scenes of the 1966 film The Battle of Algiers". Although these projects utilized French stone, they demonstrated the adaptability of his technique to a different region. One notable building of this era was the Tower of Diar es-Saâda, a 20-storey unreinforced MP stone skyscraper, which has stood undamaged for 70 years in a seismically active region.
Can Lis, 1973. The modernist architect Jørn Utzon built his house Can Lis on Mallorca from local marés sandstone. The use of quarry-precut stone in standardized, large ashlars for a modern design is considered a masterpiece, and can be said to be a major work built in MP stone. Both Utzon and Burley Griffin, two architects who won competitions for major Australian projects, built seaside sandstone houses after being removed from their competition projects.
Gilles Perraudin's revival of MP stone
Throughout the 70s, 80s and much of the 90s, mass stone was largely forgotten. In these post-Pouillon years, there were no practicing architects constructing modernist stone buildings, with the notable exception of Utzon's second stone house Can Feliz, completed in 1994. The legacy of architects like Le Corbusier and the other mainstream modernists left the focus on reinforced concrete. In the modern context, stone became associated with heritage buildings and decorative cladding of concrete.
The Vauvert Winery, 1998. Lyon-based French architect Gilles Perraudin embraced Pouillon's technique, starting with the construction of the Vauvert Winery. The winery used stone from a quarry close to Pont du Gard. A difference from Pouillon was the use of MP stone in a dry-stone (mortar-free) "trilithic," trabeated system. Eventually this building, Perraudin's other MP stone projects, and the architect's hands-on course in stone architecture would inspire renewed interest in massive precut stone construction, with a particular focus on social housing.
MP stone in the 2010s: renaissance
Apartments in Cornebarrieu, 2011. Completion of a sustainable MP stone building with 20 social-housing units in Cornebarrieu, France, designed by Perraudin. The first MP stone housing project since Pouillon was active, and led to additional phases, resulting in 104 units total. "The project followed several key principles: North-south oriented housing for proper ventilation during summer; Use of 40 cm thick structural massive stone for better high thermal inertia and summer comfort; Unprocessed and unpainted materials: solid wood window frames and shutters left untreated to age naturally; walls without plaster. Constructed with a social housing budget of €1,150/sqm (m2), this project demonstrated the modernity of stone construction, perfectly suited to today's housing demands. Massive stone allows for quick, relatively dry construction with minimal site disturbance and reduced assembly time. The stone's properties of thermal inertia, phase shift, and hygrothermal regulation make it a healthy and durable material. Recycling is limited to deconstruction and reuse of stones in their original form."
2013. House in Croix Rousse, Lyon, France. Perraudin Architects.
In Palestine in 2015, AAU Anastas architects complete the Toulkarem Courthouse, which uses MP stone with concrete.
Mixed-used building, London. In 2017, Groupwork completed 15 Clerkenwell Close, an innovative building that used massive precut stone in a post-and-lintel exoskeleton design. Unlike the Vauvert winery's triliths, the partially dimensioned blocks were left with quarry finishes except for critical contact points. The quarry-hewn approach yields a saving in dimension sawing, while facilitating precise, modular assembly with minimal or no modification during construction. The use of end-precut blocks is the first major innovation since Pouillon, as it further reduces the cost of dimension cuts, while retaining DFMA approach and modularity. The three quarry finishes (sawn, drilled, and ripped) caused controversy in the neighbourhood for years, but conversely was given city and national awards by RIBA in 2018, and shortlisted for the Stirling Prize in 2021. The building cost was £2,325 per sqm, with a contract value of £4.65m.
Social housing, Paris, 2017. In Paris' 11th district, 92 Rue Oberkampf was designed by Barrault Pressacco architects in a contemporary interpretation of Hausmannian style. Completed in 2017, the development was built using abundant limestone from the Paris Basin; 92 Rue Oberkampf demonstrated the feasibility of infill urban housing development with stone, and helped pave the way for the numerous French MP stone housing projects in the subsequent years. The building cost €3.2m for 1280 sqm, €2500 per sqm.
Plainfaing Tourist Office, France; completed in 2019, designed by Studiolada, made from pink sandstone.
In the 2010s, the housing institute of the Balearic Islands (IBAVI) started a programme to build >1000 apartments from mostly local materials. Inspired by Jørn Utzon's Can Lis and Can Feliz, they implemented a program of using precut local marés sandstone for construction. As of 2022, they had built hundreds of apartments from MP stone, and pioneered a number of novel techniques, including the implementation of stone barrel vaults for social housing, use of a fast-setting cement mixture that allows laying several courses per day, and cyclopean concrete blocks. Projects include the Salvador Espriu social-housing development in Palma de Mallorca.
In 2018 and 2019, Barrault Pressacco, an architecture firm organized an exhibition at Pavillon de l'Arsenal and published a booklet, both titled 'Pierre: Révéler la ressource, explorer le matériau' (Stone: Revealing the Resource, Exploring the Material), in which they describe the process of quarrying limestone, particularly in the Paris region, and describe the various mass-stone social-housing projects completed or ongoing in France at that time.
MP stone in the 2020s: wider adoption
The most recent MP stone housing typically uses a combination of materials, usually concrete plinths and internal structure, with load-bearing stone facades. Following the work by Perraudin and Barrault Presacco, a range of French architects adopted this method and applied it to projects across France.
2020-2021. The French government announced plans for a sustainability law mandating that new public buildings must be constructed with at least 50% timber or other natural materials. This was part of overall policy to reduce embodied carbon in new construction, a regulation that favors building with low-carbon materials like stone.
2020. Designed by architect Jean-Christophe Quinton, a building at 12 Rue Jean-Bart in Paris' 6th district was cimpleted. The project features 8 social housing units and an extension of a nursery. With its vertical openings and limestone facade, the building subtly blends into the typical Parisian street while maintaining a contemporary presence.
2020. A group of building experts published the Stone Tower Research Project showing that construction of a 30-storey skyscraper office block with a combination of an MP-stone load-bearing exoskeleton and post-tensioned stone flooring panels would cost less than the same building in concrete. In conjunction with cross-laminated timber, the stone skyscraper would be carbon negative.
2020. Massive-precut stone was featured prominently in "The New Stone Age", an exhibition at The Building Centre.
2020. Architect Raphaël Gabrion designed a sustainable building at 52 Rue des Cévennes in Paris' 15th district, comprising 9 social housing units. The design employs load-bearing massive stone on the building's periphery and an interior structure of concrete columns and slabs. The massive stone offers the advantage of total, non-destructive disassembly.
2021. In Plan-les-Ouates, Switzerland, 68 apartments completed. Designed by the Perraudin Archiplein Consortium, planning started in 2016 for 8,000 m2 of floor space over eight floors in two towers, costing €24,000,000 excl. VAT (€3,000 per sqm).
2021. Architects Denis Eliet and Laurent Lehmann completed an apartment building in MP stone. Located near the Chantiers station in Versailles, the development has 16 units, a floor space of 5,000 m2 and primarily features cut stone as its main construction material.
2021. The 6th edition of the French 21st Natural Stone Construction Prize, titled "Construire en Pierre Naturelle au XXIe Siècle" (Building with Natural Stone in the 21st Century) awarded prizes exclusively to projects using load-bearing stone construction.
2021. The Rajkumari Ratnavati Girls School, Jaisalmer, India; designed by Diana Kellogg and built in local golden sandstone precut in Jaisalmer's stonemasonry district.
2021. Eight social housing units in Gignac-la-Nerthe, France, designed, by Atelier Régis Roudil Architectes.
2022. "L’Îlot fertile" was designed by TVK architects and completed in 2022 by Bouygues Construction subsidiary Linkcity. Located in the 19th district of Paris, the development has a floor space of 35,200 m2; stone and concrete were used as the main construction materials.
2022. Perraudin and WYSWYG architects completed construction of their design of a mixed-used MP stone building in Lyon.
In December 2023, France 2 covered the resurgence of stone construction.
MP stone in planning and under construction
In 2023, a covered market in Saint-Dizier, France, designed by Studiolada, was completed.
For completion in 2023, Vincent Lavergne Architecture Urbanisme and Atelier WOA designed an apartment building 'Le Metropolitan' at 37 Rue de Lisbonne in Rosny-sous-Bois, France. This development consists of 270 housing units (including 43 social-housing units), 8 shops, and a parking facility. The building materials used for this project include cut stone from Carrières Violet in Nogent-sur-Oise, wood, and concrete. This project is one of dozens of load-bearing stone apartment buildings being built by the Verrecchia group.
Due for completion in 2024, A 10-storey MP stone building at 317 Finchley Road, London is a collaboration between architect Amin Taha of Groupwork and engineer Steve Webb. The building will use massive Sicilian basalt stones with precut ends for post-and-lintel construction.
In 2021, Barrault Pressacco announced they had won a competition to build 58 apartments in Paris 13, with a design for a 50-m mass-stone building.
In 2022, Groupwork won the competition for a housing project in Castle Park, Bristol, with a proposal that includes a low-carbon 30-storey tower from MP stone and wood. If completed, it would become the tallest massive-stone skyscraper, exceeding Pouillon's 20-storey 1953 tower in Diar es-Saâda, Algeria.
In 2022, Eric Parry Architects submitted plans for a six-storey office block using loadbearing stone and CLT in north London.
As of 2024, Groupe Pichet is preselling apartments in a stone building "Reflets de Pierres" planned for Ferney-Voltaire, designed by Perraudin.
See also
References
External links
"The New Stone Age exhibition with Steve Webb, Pierre Bidaud and Amin Taha" | Massive precut stone | [
"Engineering"
] | 5,836 | [
"Construction",
"Stonemasonry"
] |
73,746,398 | https://en.wikipedia.org/wiki/Boletus%20patrioticus | Boletus patrioticus, also known as the patriotic bolete is a basidiomycete mushroom, of the genus Boletus in the family Boletaceae. Its name comes from its coloration (red skin, white flesh, blue bruising) resembling the flag of the United States.
It is not recommended to eat, tasting sour and being likely inedible when blue.
Morphology
Cap
The cap is 3 to 13 cm in diameter, initially convex in shape, before becoming broadly convex to plane as it ages; The surface is dry with small hair, olive initially and then pinkish to dark red. The thick flesh is pale yellowish to pinkish red and does stain blue when bruised.
Pores
The pores are pale yellow when young, becoming olive yellow, bluing when bruised.
Stipe
From 2.5 to 10 cm long; 1-2 cm thick, dry, solid; rosy red on the upper part and olive on the bottom.
Spore print
The spore print is olive brown.
Spores
Subfusiform, smooth, deep golden brown, 10-13 x 4-5.5 μm
Habitat and distribution
Forms mycorrhiza with hardwoods, especially oak and hickory; fruits in grassy areas, single, scattered, in summer and fall; ranging from North Carolina to Florida (south range) and to Ohio and Texas (west range).
References
External links
patrioticus
Fungi described in 1998
Fungi of North America
Fungus species | Boletus patrioticus | [
"Biology"
] | 294 | [
"Fungi",
"Fungus species"
] |
73,746,969 | https://en.wikipedia.org/wiki/CII%2010070 | The CII 10070 is a discontinued computer system from the French company CII. It was part of the first series of computers manufactured in the late 1960s under Plan Calcul.
The 10070 is a rebadged Scientific Data Systems (SDS) Sigma 7. In addition to the Sigma software, a new operating system was developed by teams from INRIA.
The 10070 is optimized for scientific calculation. It has 32-bit words, byte addressing, and 16 index registers. It can handle both batch processing, and time-sharing. It also has as a standard feature, similar to virtual memory except that it is only intended for instant memory-to-memory remapping for performance reasons, with no support for managing swapping to disk. This is managed by the time-sharing monitor.
The 10070 served as the basis for the design of the Iris 50 and Iris 80 series, which were entirely manufactured by CII.
Software
Operating systems
The CII 10070 runs several SDS and locally developed operating systems:
BPM (Batch Processing Monitor), single-stream batch processing system with independent tasks, called symbionts, to process card and printer inputs and outputs. This system was supplied by SDS.
BTM time sharing system from SDS.
Siris 7 from CII, a version of Siris 8 for the Iris 80.
An experimental system, Ésope, was developed at IRIA.
Languages and utilities
Most of the software for the 10070 also came from SDS:
Fortran IV H compiler
Symbol (assembly language)
Metasymbol, a more powerful assembler
COBOL compiler
PL/I compiler
Sort
CII Document retrieval system: Mistral
See also
CII Iris 50
CII Iris 80
SDS Sigma series
Notes
References
External links
System description from the Bull Teams Federation (machine-translated to English).
Picture of a CII 10070 at CERN
Scientific Data Systems The Sigma Family: Introducing Sigma from Scientific Data Systems. 1967
SDS Sigma 7 technical information Sigma 7 technical information
Mainframe computers
History of computing in France
Computers designed in France | CII 10070 | [
"Technology"
] | 425 | [
"History of computing",
"History of computing in France"
] |
73,747,009 | https://en.wikipedia.org/wiki/Precipitate-free%20zone | In materials science, a precipitate-free zone (PFZ) refers to microscopic localized regions around grain boundaries that are free of precipitates (solid impurities forced outwards from the grain during crystallization). It is a common phenomenon that arises in polycrystalline materials (crystalline materials with stochastically-oriented grains) where heterogeneous nucleation of precipitates is the dominant nucleation mechanism. This is because grain boundaries are high-energy surfaces that act as sinks for vacancies, causing regions adjacent to a grain boundary to be devoid of vacancies. As it is energetically favorable for heterogeneous nucleation to occur preferentially around defect-rich sites such as vacancies, nucleation of precipitates is impeded in the vacancy-free regions immediately adjacent to grain boundaries
History
Pioneering studies on the theory and experimental observation of PFZs were made in the 1960s.
Effect on material properties
PFZs are detrimental to the mechanical properties of materials. In particular, PFZs degrade the material's hardness, because the lack of precipitates in PFZs lead to these regions having fewer pinning sites. Dislocation motion – a condition necessary to cause a material to yield – will require an appreciably lower applied shear stress in PFZs, and consequently these locally weak zones will lead to plastic deformation. The width of PFZs have also been found to be negatively correlated with intergranular fracture
PFZs also accelerate pitting corrosion and stress corrosion cracking, significantly reducing the usable life of these materials in chemically aggressive environments.
Techniques to minimize
It has been shown that PFZs can be minimized by quenching. First, quenching increases undercooling, favoring homogeneous nucleation in PFZs as it lowers the nucleation energy barrier even in the absence of potent nucleation sites. Additionally, low temperatures also lead to a reduction in diffusion rates, minimizing the loss of vacancies and premature growth of grain boundary precipitates. However, since diffusion rates at low temperatures are suppressed, the aging time (time taken for treatment to yield a desired grain size) would be long. Therefore, one processing technique to circumvent this is to increase the temperature slightly once a sufficient number of homogeneous nucleation sites have been formed.
Another technique to minimize PFZs is to introduce impurity elements, as they strongly interact with vacancies and allow for a more even distribution of vacancies in the material. One example would be to introduce Mg in Al alloys
Cyclic strengthening (CS), a process wherein a material is mechanically pushed and pulled repeatedly at room temperature, creates fine precipitates that is homogeneously distributed throughout the microstructure. It has been suggested as an alternative to conventional, precipitate hardened alloys as this process achieves strengthening effects without introducing PFZs.
References
Materials science | Precipitate-free zone | [
"Physics",
"Materials_science",
"Engineering"
] | 627 | [
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
73,747,903 | https://en.wikipedia.org/wiki/Terminal%20concentrator | Terminal concentrators, also known as terminal multiplexers, were hardware devices used to multiplex multiple serial terminals to a single hardware computer connection. Examples of terminal multiplexers were the IBM 3299 and the terminal multiplexers made by Gandalf Technologies.
References
See also
Concentrator
Modem sharing device
Computer terminals | Terminal concentrator | [
"Technology"
] | 69 | [
"Computing stubs"
] |
73,748,541 | https://en.wikipedia.org/wiki/Chroogomphus%20ochraceus | Chroogomphus ochraceus is a species of fungus from the family Gomphidiaceae. Known for its close association with conifer trees–especially pines, it is often referred to as the "pine spike" or "spike cap" fungus. C. ochraceus was originally identified as a species limited to the Pacific Northwest because of its display of distinct yellowish colors, but recent research has concluded that this species is widespread across North America and that it is genetically distinct from Chroogomphus rutilus, which is limited to Europe.
Taxonomy
Although colloquially referred to as a "mushroom", Chroogomphus species fall into the order Boletales, and are only considered "agaricoids" (fungi with mushroom-like fruiting structures).
The classification of Chroogomphus ochraceus has been the topic of debate over recent years. Originally, the European species C. rutilus was thought to be distributed across Europe as well as most of North America. C. ochraceus was thought to be limited to the Pacific Northwest because of the vivid yellowish colors it can produce in that environment. However, recent investigation has found that what has previously been called Chroogomphus rutilus in the United States is genetically distinct from individuals from Europe. Furthermore, C. ochraceus strains from the Pacific Northwest were found to be capable of producing the same colors typical of other species of Chroogomphus if given the right conditions.
It is now consensus that Chroogomphus rutilus is the European species, and Chroogomphus ochraceus is the American species. Individuals previously called C. rutilus in North America are now called C. ochraceus. Another American species, Chroogomphus vinicolor appears superficially similar, but features thick-walled cystidia compared to C. ochraceus''' more brittle cystidia.
Description Chroogomphus species are recognizable for their deep brown to apricot-orange hues. The pileus (cap) of C. ochraceus forms with a conical shape when young, and usually flattens out into a table-top shape–sometimes with a small depression in the center– at maturity where it typically measures 3–9 cm across. The decurrent gills extend from the edge of the cap all the way to the stipe, growing thicker as they extend down, typical of other gilled boletes. Stipe grows thicker at the base, does not bruise when cut, and does not have a distinctive scent.
Spores are thin-walled and somewhat elliptical, measuring 15–24 x 5–8 μm. Spore mass appearing dull gray-black when observed macroscopically.
Habitat, ecology, and distribution
This species is found all across North America and Hispaniola, reaching into Canada at the north end of its distribution and reaching to Mexico at the southern end. It is known to fruit throughout summer and early fall during cool weather, but can fruit through the winter in areas of Coastal California. It fruits in small clusters.
It was originally thought that since Chroogomphus species are so closely associated with conifer trees, that the two organisms shared a mycorrhizal relationship. Now it is understood that Chroogomphus are likely a parasite of other boletes, Suillus species, that are associated with conifers themselves.
Edibility
It is consensus that Chroogomphus ochraceus, along with the other North American Chroogomphus'' species, are edible. However, it has no distinct scent or flavor, and is therefore less desirable as a culinary fungus.
References
Boletales
Fungi of North America
Fungi of Mexico
Fungus species | Chroogomphus ochraceus | [
"Biology"
] | 765 | [
"Fungi",
"Fungus species"
] |
67,900,481 | https://en.wikipedia.org/wiki/Angular%20correlation%20function | The angular correlation function is a function which measures the projected clustering of galaxies, due to discrepancies between their actual and expected distributions. The function may be computed as follows: , where represents the conditional probability of finding a galaxy, denotes the solid angle, and is the mean number density. In a homogeneous universe, the angular correlation scales with a characteristic depth.
References
Galaxy clusters
Equations of astronomy | Angular correlation function | [
"Physics",
"Astronomy"
] | 82 | [
"Galaxy clusters",
"Galaxy stubs",
"Concepts in astronomy",
"Astronomy stubs",
"Equations of astronomy",
"Astronomical objects"
] |
67,901,308 | https://en.wikipedia.org/wiki/Venus%20Emissivity%20Mapper | The Venus Emissivity Mapper (VEM) is a spectrometer for mapping the surface composition of Venus through a distinct number of atmospheric spectral windows. It will be one of the two payloads onboard the VERITAS mission, and will also be the VenSpec-M channel of the EnVision mission's spectrometer suite.
Overview
While Earth and Venus are similar in many aspects, they evolved very differently and currently have distinct surface and atmospheric environments. Where Earth's surface has liquid water and supports life, Venus experiences a mean surface temperature of over 400 °C, and a carbon dioxide rich atmosphere with a surface pressure of about 92 times that of Earth at sea-level.
Little is known about Venus' surface composition. The dense atmosphere and its cloud layers are mostly opaque to visible and infrared radiation, making remote sensing a challenge. As light travels through the atmosphere, it is attenuated by absorption and scattering, and it is blurred by the emissions of the atmosphere itself. Observations of Venus have shown that the surface can be observed through a number of narrow infrared bands. Using this technique Venus Express was able to observe fresh basalt, pointing towards recent volcanic activity on the surface.
The spectral windows were at the edge of Venus Express' VIRTIS instrument's sensitive spectral range. VIRTIS also experienced thermal drifts and had issues with stray-light. This was because VIRTIS was not designed for ground mapping, yet it allowed for a proof-of-concept leading to VEM's design. VEM will be the first instrument in orbit around Venus focussed solely on these spectral bands, allowing for a complete mapping of the surface composition and surface redox states.
VEM was selected for NASA's VERITAS mission and for ESA's EnVision mission in June 2021. The principal investigator is Jörn Helbert, and the instrument is built by the DLR in Berlin.
Goal
The goal of this instrument is to obtain a full mapping of the rock types, their iron content, and their redox states from orbit. Laboratory measurements have shown that a 4% difference in relative emissivity is sufficient to distinguish between the different rock types, and potentially identify their weathering states. This is thus the design driver for the instrument. An identification of the ground composition based on measured spectra is only possible once a spectral library representing the surface conditions of Venus is available, which has been in the works at the Planetary Spectroscopy Laboratory at DLR. By continuously monitoring the surface, it will be possible to further constrain the current volcanic activity. In addition to that, any surface information will contribute towards understanding the past evolution of Venus leading up to its current state.
Description
History and heritage
Spectral windows have been used by several space-based (Venus Express, Galileo and Cassini) and ground-based missions to study Venus. While these mostly represented proof of concepts, they gave rise to the idea for the Venus Emissivity Mapper, which is building on the flight heritage of all the aforementioned missions, especially so on VIRTIS and VMC aboard Venus Express. VEM was first put forward as part of the EnVision mission proposal in 2010. At the same time, the first Venus-analogue measurements began surfacing, making it possible to derive surface compositions from the measured Venus emissivities. EnVision's initial proposal was not accepted, and so the design was iterated upon so that a new proposal could be made in 2014 and again in 2016. ESA selected it for an in-depth design study in 2018 and three years later, ESA declared EnVision — with VEM (VenSpec-M) aboard — the fifth M-class Cosmic Vision mission.
The Venus Emissivity Mapper was also submitted to the NASA Discovery Program as part of the VERITAS proposal in 2014. It was initially selected for Phase A funding but not chosen for flight. In 2019, an updated proposal was submitted to the Discovery Program, once more receiving Phase A funding. Two years later, in June 2021, the announcement about VERITAS' official selection was made public.
Building onto the heritage of previous missions, all subsystems have a TRL level of at least 6, thereby giving VEM an overall TRL of 6.
Science
Observations will be made at night measuring the emissivity signal from the surface.
Typically, igneous rocks are identified by their sodium, potassium, and silicon content. However these elements lack observable features in the 1 μm spectral band. Instead, transition metals (primarily Fe), and their spectral features in the relevant windows, will be used to characterise the surface composition. This map of iron content will then, with topological data, be used to generate a map of inferred rock types.
In order for these measurements to be absolute rather than relative, the measurements are to be calibrated using the data gathered by the Venera landers when overflying their landings zones.
Design
VEM is a multispectral imaging instrument, operating as a pushbroom scanner. It consists of the following subsystems: The optical sub-system (VEMO), the Instrument Controller (VEMIC), the power supply (VEMPS), and the two-stage baffle (VEMBA). The development approach is analogue to what was successfully done when designing MERTIS. This means that one starts with a breadboard, moves on to a lab prototype, follows that up by an engineering prototype, and finally reaches the full qualification model. Along the way, risks are constantly identified and mitigated.
Optics (VEMO)
The optics sub-system is a three lens system, provided by LESIA, Observatoire de Paris, France. First, a telescope with an aperture of 8 mm and a focal length of 40.5 mm projects the scene on the filter array. From there, it is then imaged on the focal plane through two more lenses with a combined magnification factor of 0.4. The optics have a total transmittance of 0.88, not taking into account the filters. The focal plane array (VEMFPA) consists of a Xenics XSW-640 InGaAs detector, which has a resolution of 640x512 pixel, a FOV of 30°×45°, a pixel pitch of 20 μm, and a pixel FOV of 0.07°×0.07°. The imaging electronics unit used is LM98640QML-SP from Texas Instruments. InGaAs detectors have been used in deep space successfully over many years, making it a safe choice. This specific unit is currently in use on the ExoMars Trace Gas Orbiter.
The filter array is provided by CNES Toulouse, France. Narrow-band filters takes care of only transmitting the spectral region of interest. Based on the 4% relative emissivity that is needed to differentiate between the different rock types, the signal-to-noise ratio (SNR) for each band is derived by running the respective radiative transfer model. The bands and their required SNRs are found in the following table:
Instrument controller (VEMIC)
The instrument controller is the interface between the internal units and the spacecraft. It handles and processes all the data, and controls the subsystem. The system used in VEM is taken from MERTIS, with only the interfaces needing adaptation to comply with VEM.
Power system (VEMPS)
The main power draw is coming from the focal plane array and the instrument controller. This sub-system is heavily based upon the MERTIS PSU, as the latter is already flight-proven. The main part of the PS is a DC/DC converter from the Interpoint SMRT series, which is supplemented by external LC-filters and some additional specialised circuitry.
Baffle (VEMBA)
To keep stray- and sunlight out, a two-stage baffle is employed. The front part is mainly a screen to protect the spacecraft, while the back part is the one taking care of the stray-light. The baffle aims to reduce stray light to a factor of at least 10−5.
Signal optimisations
Atmospheric effects
When looking at the spectral bands presented earlier, one can see that next to the six bands used for mineralogical measurements, eight more are present. Those additional bands are used to correct for the various effects altering the signal between the surface of Venus and the measuring spacecraft. By measuring the atmosphere on its own, the effects of it and the varying conditions it introduces can be considered. The same is done for stray-light, for which three dedicated channels are used.
Signal-to-noise ratio
As the integration time for a satellite in orbit can hardly be optimised, a few other techniques are applied to get the highest possible signal-to-noise performance. Those improvements are:
Oversampling during one dwell time (for slow orbits)
Discrete Time-Delayed Integration (TDI)
Spatial binning (macro-pixels)
Once applied, even for an orbit altitude of 8000 km, the SNR required to reach the necessary accuracy is theoretically attained with margins of more than 100% for all bands. For orbit altitudes around 250 km, the SNR is close to 10 times better than the one obtained at 8000 km. A laboratory prototype showed potential for a later SNR performance of well over 1000.
Reducing uncertainties
By optimising the detector for the relevant wavelengths, and by making use of the additional spectral ranges, the effects of atmosphere and stray-light are accounted for, thereby significantly lowering the uncertainty in the measurements — as described above. The uncertainties are further reduced by having an overlapping ground coverage (to take care of short-term atmospheric variability), and repeated measurements (to reduce error due to uncertainty in water vapour content, cloud opacity, and surface window radiance).
References
Spacecraft instruments
Spectrometers | Venus Emissivity Mapper | [
"Physics",
"Chemistry"
] | 2,020 | [
"Spectrometers",
"Spectroscopy",
"Spectrum (physical sciences)"
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67,902,375 | https://en.wikipedia.org/wiki/Self-supervised%20learning | Self-supervised learning (SSL) is a paradigm in machine learning where a model is trained on a task using the data itself to generate supervisory signals, rather than relying on externally-provided labels. In the context of neural networks, self-supervised learning aims to leverage inherent structures or relationships within the input data to create meaningful training signals. SSL tasks are designed so that solving them requires capturing essential features or relationships in the data. The input data is typically augmented or transformed in a way that creates pairs of related samples, where one sample serves as the input, and the other is used to formulate the supervisory signal. This augmentation can involve introducing noise, cropping, rotation, or other transformations. Self-supervised learning more closely imitates the way humans learn to classify objects.
During SSL, the model learns in two steps. First, the task is solved based on an auxiliary or pretext classification task using pseudo-labels, which help to initialize the model parameters. Next, the actual task is performed with supervised or unsupervised learning.
Self-supervised learning has produced promising results in recent years, and has found practical application in fields such as audio processing, and is being used by Facebook and others for speech recognition.
Types
Autoassociative self-supervised learning
Autoassociative self-supervised learning is a specific category of self-supervised learning where a neural network is trained to reproduce or reconstruct its own input data. In other words, the model is tasked with learning a representation of the data that captures its essential features or structure, allowing it to regenerate the original input.
The term "autoassociative" comes from the fact that the model is essentially associating the input data with itself. This is often achieved using autoencoders, which are a type of neural network architecture used for representation learning. Autoencoders consist of an encoder network that maps the input data to a lower-dimensional representation (latent space), and a decoder network that reconstructs the input from this representation.
The training process involves presenting the model with input data and requiring it to reconstruct the same data as closely as possible. The loss function used during training typically penalizes the difference between the original input and the reconstructed output (e.g. mean squared error). By minimizing this reconstruction error, the autoencoder learns a meaningful representation of the data in its latent space.
Contrastive self-supervised learning
For a binary classification task, training data can be divided into positive examples and negative examples. Positive examples are those that match the target. For example, if training a classifier to identify birds, the positive training data would include images that contain birds. Negative examples would be images that do not. Contrastive self-supervised learning uses both positive and negative examples. The loss function in contrastive learning is used to minimize the distance between positive sample pairs, while maximizing the distance between negative sample pairs.
An early example uses a pair of 1-dimensional convolutional neural networks to process a pair of images and maximize their agreement.
Contrastive Language-Image Pre-training (CLIP) allows joint pretraining of a text encoder and an image encoder, such that a matching image-text pair have image encoding vector and text encoding vector that span a small angle (having a large cosine similarity).
InfoNCE (Noise-Contrastive Estimation) is a method to optimize two models jointly, based on Noise Contrastive Estimation (NCE). Given a set of random samples containing one positive sample from and negative samples from the 'proposal' distribution , it minimizes the following loss function:
Non-contrastive self-supervised learning
Non-contrastive self-supervised learning (NCSSL) uses only positive examples. Counterintuitively, NCSSL converges on a useful local minimum rather than reaching a trivial solution, with zero loss. For the example of binary classification, it would trivially learn to classify each example as positive. Effective NCSSL requires an extra predictor on the online side that does not back-propagate on the target side.
Comparison with other forms of machine learning
SSL belongs to supervised learning methods insofar as the goal is to generate a classified output from the input. At the same time, however, it does not require the explicit use of labeled input-output pairs. Instead, correlations, metadata embedded in the data, or domain knowledge present in the input are implicitly and autonomously extracted from the data. These supervisory signals, extracted from the data, can then be used for training.
SSL is similar to unsupervised learning in that it does not require labels in the sample data. Unlike unsupervised learning, however, learning is not done using inherent data structures.
Semi-supervised learning combines supervised and unsupervised learning, requiring only a small portion of the learning data be labeled.
In transfer learning, a model designed for one task is reused on a different task.
Training an autoencoder intrinsically constitutes a self-supervised process, because the output pattern needs to become an optimal reconstruction of the input pattern itself. However, in current jargon, the term 'self-supervised' often refers to tasks based on a pretext-task training setup. This involves the (human) design of such pretext task(s), unlike
the case of fully self-contained autoencoder training.
In reinforcement learning, self-supervising learning from a combination of losses can create abstract representations where only the most important information about the state are kept in a compressed way.
Examples
Self-supervised learning is particularly suitable for speech recognition. For example, Facebook developed wav2vec, a self-supervised algorithm, to perform speech recognition using two deep convolutional neural networks that build on each other.
Google's Bidirectional Encoder Representations from Transformers (BERT) model is used to better understand the context of search queries.
OpenAI's GPT-3 is an autoregressive language model that can be used in language processing. It can be used to translate texts or answer questions, among other things.
Bootstrap Your Own Latent (BYOL) is a NCSSL that produced excellent results on ImageNet and on transfer and semi-supervised benchmarks.
The Yarowsky algorithm is an example of self-supervised learning in natural language processing. From a small number of labeled examples, it learns to predict which word sense of a polysemous word is being used at a given point in text.
DirectPred is a NCSSL that directly sets the predictor weights instead of learning it via typical gradient descent.
Self-GenomeNet is an example of self-supervised learning in genomics.
Self-supervised learning continues to gain prominence as a new approach across diverse fields. Its ability to leverage unlabeled data effectively opens new possibilities for advancement in machine learning, especially in data-driven application domains.
References
Further reading
External links
Machine learning
Generative artificial intelligence | Self-supervised learning | [
"Engineering"
] | 1,455 | [
"Artificial intelligence engineering",
"Generative artificial intelligence",
"Machine learning"
] |
67,902,543 | https://en.wikipedia.org/wiki/Boundaries%20of%20Hong%20Kong | The Boundaries of Hong Kong, officially the Boundary of the Administrative Division of the Hong Kong Special Administrative Region of the People's Republic of China (), is a regulated administrative border with border control in force under the One country, two systems constitutional principle, which separates the Hong Kong Special Administrative Region from mainland China, by land border fence of and maritime boundary of , enforcing a separate immigration and customs-controlled jurisdiction from mainland China.
The boundaries of Hong Kong are patrolled and controlled by the Hong Kong Police Force and its Marine Region and the Immigration Department at land and sea. The land boundary also includes a buffer zone, known as Frontier Closed Area.
History
After the First Opium War and territorial establishment of Hong Kong, the Hong Kong Island was ceded by the Qing Empire to the United Kingdom of Great Britain and Ireland through Treaty of Nanjing in 1842, not marking any official maritime boundaries.
In 1860, the Convention of Peking extended the cession to include Kowloon with the land boundary limits until "Boundary street in Kowloon", and in 1898 with additional land of New Territories was leased for 99-years to the British under the Convention for the Extension of Hong Kong Territory with the Sham Chun River primarily marking the boundary between British Hong Kong and Qing dynasty.
Between the years of 1941 and 1945 during the Japanese occupation of Hong Kong, the boundaries of Hong Kong may or may not have been clearly distinguished as the neighbouring part of Southern China bordering Hong Kong was also occupied by the Japanese Empire. After the Japanese surrender in 1945, all British government institutions in Hong Kong, including the land boundary primarily running across the Sham Chun River were restored.
Since the late 1940s, there has been a refugee wave from mainland China due to the instability inland, and the British authorities in Hong Kong were forced to make a decision regarding the border to prevent an influx of refugees from overwhelming the already-crowded city. In April 1949, the British decided to close the border and end the free movement that existed prior. By 1952, the Chinese authorities had done the same, and the border officially became closed and required permits to cross through.
In 1984, the governments of the United Kingdom and the People's Republic of China (PRC) concluded the Sino-British Joint Declaration on the Question of Hong Kong, under which the sovereignty of the leased territories, together with Hong Kong Island and Kowloon (south of Boundary Street) ceded under the Convention of Peking (1860), was transferred to the PRC on 1 July 1997, maintaining the current land boundary primarily running across the Sham Chun River, however the Hong Kong Basic Law modified and extended the size of Hong Kong's maritime boundary with mainland China in 1997.
Historical maps
Immigration control points
As of 2024, 8 out of Hong Kong's 13 points of entry or border crossings controlled by the Immigration Department are located on or cross the land border fence. Entry and exit immigration clearance into Hong Kong by sea can be cleared at 3 ferry terminals:, and the other 2 out of 13 immigration clearance points in Hong Kong are located in the Hong Kong West Kowloon railway station and at the Hong Kong International Airport.
See also
Borders of China
Boundaries of Macau
Frontier Closed Area
References
H
Borders of Hong Kong
Borders of China
British Hong Kong
Law enforcement in Hong Kong
North District, Hong Kong
Yuen Long District | Boundaries of Hong Kong | [
"Engineering"
] | 666 | [
"Separation barriers",
"Border barriers"
] |
67,903,344 | https://en.wikipedia.org/wiki/Dysprosium%28II%29%20chloride | Dysprosium(II) chloride (DyCl2), also known as dysprosium dichloride, is an ionic chemical compound of dysprosium and chlorine. This salt is a reduced compound, as the normal oxidation state of dysprosium in dysprosium compounds is +3.
Dysprosium dichloride is glossy black in appearance. The salt is damaged by oxidation on exposure to air. It is an electrical insulator.
The structure is the same as for strontium bromide, ytterbium dichloride, and terbium dichloride. There are two forms. The low temperature form is below 652 °C. It is orthorhombic with unit cell dimensions a=6.69, b=6.76, and c=7.06 Å.
Preparation
Dysprosium dichloride can be prepared by heating molten dysprosium trichloride with dysprosium metal, and rapidly quenching. Molybdenum, niobium or tantalum crucibles are required to avoid alloy formation with the dysprosium.
Reactions
Dysprosium dichloride is capable of reducing titanium dichloride to titanium metal in a potassium chloride, sodium chloride flux.
Ti2+ + 2Dy2+ → Ti (solid) + 2Dy3+
Related
A ternary dysprosium(II) chloride compound is known with lithium: LiDy2Cl5. This is produced by heating lithium metal and dysprosium trichloride together at 700 °C. This compound is also black. The crystal system of LiDy2Cl5 is monoclinic with space group C2/c 4 formulae per unit cell which has dimensions; a = 16.45.6(; b = 6.692; and c = 7.267; with β = 95.79°.
References
Dysprosium compounds
Chlorides
Lanthanide halides | Dysprosium(II) chloride | [
"Chemistry"
] | 431 | [
"Chlorides",
"Inorganic compounds",
"Salts"
] |
67,903,453 | https://en.wikipedia.org/wiki/Mouza%20Sulaiman%20Mohamed%20Al-Wardi | Mouza Sulaiman Mohamed Al-Wardi () is a curator and historian from Oman, who is Director of the Collections Department at the National Museum. She specialises in the history of silverworking in the Oman region.
Career
Al-Wardi is the Director of the Collections Department at the National Museum of Oman. She was appointed to the role in 2019. She joined the museum in 2009 as Chief Curator during its construction and development. She is a specialist in historical metal-working, in particular in bronze and silver. She is an expert on the history of silversmithing, particularly in Oman, which has a historic tradition of women working as silversmiths, particularly in southern Oman in Dhofar. The project is a collaboration between Aude Mongiatti (British Museum), Fahmida Suleman (Royal Ontario Museum), Marcia Dorr and Al-Wardi. As part of this work she has studied the coinage that circulated in Oman and in particular its re-use into coin pendants. Al-Wardi has also worked on the Diba Hoard, an assemblage of stone vessels and bronze metalwork dating to 1200 - 300 BCE.
In 2013 she was a candidate on the British Museum's International Training Programme. She previously studied for a BA degree in Heritage and Cultural Studies from Curtin University (formally known as Western Australian Institute of Technology) in Perth. After graduation she worked at the Museum of Omani Heritage, developing training programmes and working on their heritage craft programme. In 2018 she was part of a UNESCO-hosted regional event in Kuwait, which focussed on the development of national museums.
References
External links
ArCHIAM: Decoration and Construction of Omani Traditional Architecture
National Museum (Oman): Our Staff
Youtube: Magan and Copper - National Museum of Oman
Living people
Year of birth missing (living people)
21st-century Omani women
21st-century Omani people
Women curators
Curators
Metallurgists
Curtin University alumni
Women art historians | Mouza Sulaiman Mohamed Al-Wardi | [
"Chemistry",
"Materials_science"
] | 406 | [
"Metallurgists",
"Metallurgy"
] |
67,903,918 | https://en.wikipedia.org/wiki/Firecracker%20%28software%29 | Firecracker is virtualization software developed by Amazon Web Services. It makes use of KVM.
References
External links
Amazon Web Services
Free software programmed in Rust
Free virtualization software | Firecracker (software) | [
"Technology"
] | 37 | [
"Computing stubs",
"Computer hardware stubs"
] |
67,904,032 | https://en.wikipedia.org/wiki/Paye%20ta%20shnek | Paye ta shnek (« paye ta chatte » in Alsacian argot) was a web site created in 2012 by Anaïs Bourdet that collected accounts of street harassment from women.
In 2013, the website published a book containing a selection of the testimonies. The book was published following a crowd fundraising effort and published by Fayard.
In June 2019, Bourdet announced that the site would stop being updated.
Bibliography
References
Feminism in France
French-language websites
Harassment and bullying | Paye ta shnek | [
"Biology"
] | 108 | [
"Harassment and bullying",
"Behavior",
"Aggression"
] |
67,904,307 | https://en.wikipedia.org/wiki/List%20of%20partially%20guyed%20towers | This is a list of partially guyed towers.
See also
List of additionally guyed towers
References
Partially guyed
Guyed masts
Towers, partially guyed | List of partially guyed towers | [
"Engineering"
] | 33 | [
"Structural engineering",
"Towers"
] |
67,905,625 | https://en.wikipedia.org/wiki/DYNAS | DYNAS (from Dynamic Selectivity) is a dynamic analog filtering and tuning technology to improve the reception of FM radio broadcasts under adverse conditions.
Overview
The trademarked DYNAS system is based on the same principles as the In Channel Select (ICS) system by H.u.C. Elektronik. The novel tracking filter arrangement was originally conceived by the German engineer Jens Hansen in 1982. The concept was prototyped as High Select in summer 1983. With funding from innovation funds of the city of Berlin, Hansen left Bosch/Blaupunkt to start, with companion Klaus Müller-Catito, his own company H.u.C. Elektronik in 1984. When licensing negotiations with his former employer failed, the system was marketed in the early 1990s as DYNAS by the German Telefunken electronic (a spin-off of AEG-Telefunken and DASA, firming as since 1992), who, with the related (the former AEG-Telefunken Halbleiterwerk in Heilbronn), also designed integrated circuits implementing the system, the TEMIC/TFK U4290B (stand-alone FM IF DYNAS system in 68-pin PLCC package), U4291B (DYNAS coprocessor) and U4292B (software-controlled DYNAS system in 44-pin SSO package).
Compared to conventional receivers, DYNAS has a more than 26 dB better selectivity and a typically twice as good sensitivity (improved by 6 dB) thereby almost doubling the reception area and allowing to receive even extremely noisy stations. This is achieved by an adaptive bandwidth of the IF filter and by dynamically tracking of the center frequency of the IF filter in real-time.
With a transmitter spacing of 200 kHz an undisturbed reception in stereo is possible, with 100 kHz a largely undisturbed mono reception is still possible.
The principle has been adopted in some high-end FM tuners like the analog Burmester Tuner 915 (1991) or the digital synthesizer tuners Onkyo Integra T-4970 (1992) and T-488F (1993) as well as in various car radios, such as the Alpine 7619R (1989) and 1310R/3681 (1990), the JVC KS-CG10 (1992), the Clarion CRX121R (1993), CRX123R (1993), CRX121RM and CRX123RM, the Gelhard GXR 990S (1993) or the Conrad Soundcraft AR6800 DYNAS, which are particularly affected by difficult and rapidly changing reception conditions.
Similar technologies
The In Channel Select (ICS) system by H.u.C. Elektronik in 1984 is a DYNAS predecessor mainly for narrowband FM receivers. It is based on the High Select tracking filter (German: aka ) developed by Jens Hansen since 1982. ICS improved the selectivity by about 20 dB and the sensitivity by about 6 dB.
A very similar technology is the Active Real-time Tracing System (ARTS), as was implemented in the Pioneer Elite F-91 and some versions of the F-717 high-end tuners in 1987.
Super Sound Tracing (SST) is a similar technology by Sony affecting the RF rather than the IF stage. A four-stage SST system was implemented in high-end tuners such as the ST-S555ESX (1986), ST-S333ESX (1986), ST-S444ESX/ST-S700ES (1987), ST-S800ES (1987) and ST-S333ESX II (1987)/ST-S730ES (1988). Advanced SST, dividing the tuning range into 32 sections, was implemented in some model variants of the ST-S739ES, ST-S333ESG (1989)/ST-S770ES (1990) ST-S333ESA (1991), ST-S333ESJ (1993), ST-S707ES (1993) and ST-SA5ES (1994/1996).
Blaupunkt's Sharx technology, as introduced in 1997 in the Modena & Lausanne RD 148 car radios with "DigiCeiver", is a similar digital solution implemented in software. The original Sharx implementation still relied on a bank of switchable analog ceramic resonators for the IF filter stage before the A/D conversion for further processing of the signal in the DSP section. Around 2000, the switchable IF filter moved into the digital domain as well, that is, it was integrated into the DigiCeiver/TwinCeiver chip leaving only the first stage of the IF filter a discrete part.
See also
Syntektor
FM DX
Frequency-following receiver
Threshold extension demodulation
Frequency demodulator using feedback or FM, FM feedback (FMFB)
Notes
References
Further reading
(6 pages)
(viii+750+9+v pages)
(9 pages)
(34 pages) ; (15 pages) (NB. Presented before the New York Section of the I.R.E. on 1939-05-03.)
(7 pages)
FR8121986A
http://antique-autoradio-madness.org/alpine/Alpine-1989/alpine-1989-cata_4.htm
https://www.fmtunerinfo.com/ST-SA5service.pdf (Describes the old PCB layout in a model variant without SST populated.)
https://patentimages.storage.googleapis.com/8d/fc/40/37ed83234d8c81/US4293818.pdf
https://www.rundfunkforum.de/viewtopic.php?t=15593
Radio technology
Radio electronics | DYNAS | [
"Technology",
"Engineering"
] | 1,257 | [
"Information and communications technology",
"Radio electronics",
"Telecommunications engineering",
"Radio technology"
] |
67,906,854 | https://en.wikipedia.org/wiki/%22What%20I%20eat%20in%20a%20day%22%20video | "What I eat in a day" videos are a trend on several social media platforms where a person describes all the meals and snacks that they eat during a given day, often as part of a given diet. The videos, shared on platforms including Twitter, TikTok and YouTube, become increasingly popular in 2020, with some of them accumulating millions of views, and they are considered a profitable industry for the people making them. Some have raised concerns that the videos may promote an unrealistic standard for healthy eating and contribute to the development of eating disorders.
Format
These videos often feature a montage of the food that the creator eats over the course of the day, sometimes with the associated calorie count of the foods that they describe. Unlike related mukbang videos, however, in which participants eat large amounts of food, the diets described are often restrictive. However, other videos are labeled as "unhealthy" and depict large portion sizes and higher amounts of processed food.
Popularity
"What I eat in a day" videos have existed for a long time, especially on YouTube, but they have become much more widespread in recent years. This phenomenon is self-reinforcing because when social media users watch or like these videos they are likely to see more of them in the future. Indeed, some of the most successful videos have tens of millions of view each.
Criticism and controversy
Several dieticians and mental health professionals over the impacts that these videos can have, as they can advocate a restrictive style of eating and not "promote body diversity." They have also raised concerns that this trend could contribute to a rise in disordered eating, especially since use of social media is known to increase feelings of negative body image. This trend is particularly prevalent among young adults, which are also the group with the highest vulnerability to eating disorders.
More recently, a portion of these videos have begun to challenge diets and depict more realistic ways of eating in order to reduce the potential consequences of the trend.
See also
Dieting
Social media and psychology
References
Nutrition
Social media
2020s in food | "What I eat in a day" video | [
"Technology"
] | 422 | [
"Computing and society",
"Social media"
] |
67,908,475 | https://en.wikipedia.org/wiki/List%20of%20countries%20by%20average%20annual%20precipitation | This is a list of countries by average annual precipitation.
List
See also
List of countries by average yearly temperature.
Notes
References
precipitation
Climate and weather statistics
precipitation | List of countries by average annual precipitation | [
"Physics"
] | 32 | [
"Weather",
"Physical phenomena",
"Weather-related lists",
"Climate and weather statistics"
] |
67,908,573 | https://en.wikipedia.org/wiki/HD%20219617 | HD 219617 is a binary star system some 220 light-years away from the Solar System in the constellation Aquarius. It is composed of two metal-poor F-type subdwarf stars orbiting each other in a 388-year orbit. Another theory suggests that the binary star is composed of subgiant stars. Unlike many halo stars, which exhibit an excess of alpha elements relative to iron, HD 219617 is depleted in iron peak and alpha elements, although alpha elements concentrations are poorly constrained. The stellar chemical composition is peculiar, being relatively oxygen-enriched and extremely depleted in neutron capture elements. The helium fraction of the binary star at present cannot be reliably determined, and appears to be near the primordial helium abundance.
The binary star HD 219617 is part of the hierarchical triple system LDS 6393, together with the red subdwarf VB 12 (LHS 541) of spectral class sdM3 at a projected separation of 19″ (1,200 AU). VB 12 also has several peculiarities. The star system belongs kinematically to the halo stars. Additional stellar components of the star system are suspected.
The binary nature of HD 219617 has been known since the 19th century, but uncertainties in measurement and a stellar conjunction in 1920 precluded determining even an approximate orbit until 1991. Then in 2017, the orbit was measured accurately, as separation between the stars increased.
References
Aquarius (constellation)
F-type subdwarfs
Binary stars
J23170501-1351046
219617
BD-14 6437
114962 | HD 219617 | [
"Astronomy"
] | 334 | [
"Constellations",
"Aquarius (constellation)"
] |
67,909,501 | https://en.wikipedia.org/wiki/Heterocrine%20gland | Heterocrine glands (or composite glands) are the glands which function as both exocrine gland and endocrine gland. These glands exhibit a unique and diverse secretory function encompassing the release of proteins and non-proteinaceous compounds, endocrine and exocrine secretions into both the bloodstream and ducts respectively. This duality allows them to serve crucial roles in regulating various physiological processes and maintaining homeostasis. These include the gonads (testicles and ovaries), pancreas and salivary glands.
Pancreas releases digestive enzymes into the small intestine via ducts (exocrine) and secretes insulin and glucagon into the bloodstream (endocrine) to regulate blood sugar level. Testes produce sperm, which is released through ducts (exocrine), and they also secrete androgens into the bloodstream (endocrine). Similarly, ovaries release ova through ducts (exocrine) and produce estrogen and progesterone (endocrine). Salivary glands secrete saliva through ducts to aid in digestion (exocrine) and produce epidermal growth factor and insulin-like growth factor (endocrine).
Anatomy
Heterocrine glands typically have a complex structure that enables them to produce and release different types of secretions. The two primary components of these glands are:
Endocrine component: Heterocrine glands produce hormones, which are chemical messengers that travel through the bloodstream to target organs or tissues. These hormones play a vital role in regulating numerous physiological processes, such as metabolism, growth, and the immune response.
Exocrine component: In addition to their endocrine function, heterocrine glands secrete substances directly into ducts or cavities, which can be released through various body openings. These exocrine secretions can include enzymes, mucus, and other substances that aid in digestion, lubrication, or protection.
Characteristics and functions
Heterocrine glands serve diverse functions, including:
Dual secretion: The hallmark feature of heterocrine glands is their ability to release both hormones and other substances through different mechanisms. This dual secretion provides them with versatility in terms of influencing local and systemic processes.
Structural diversity: These glands can take on various structural forms, depending on their specific location and function within the body. For example, Pancreas is a classic example of a heterocrine gland with distinct endocrine and exocrine regions.
Regulation: Heterocrine glands are subject to intricate regulation, ensuring precise control over the secretion of hormones and other secretory products. This regulation involves feedback mechanisms, receptor interactions, and neural input.
Hormone regulation: Heterocrine glands contribute to the regulation of various physiological processes, such as metabolism, blood glucose levels, and digestion by secreting hormones into the bloodstream.
Digestive enzyme production: The exocrine component of heterocrine glands produces enzymes required for the breakdown of ingested food in the gastrointestinal tract.
Gonads
Endocrine function: Gonads release hormones directly into the bloodstream. In males, Testes produce androgens mainly testosterone, which is essential for the development of male secondary sexual characteristics and the regulation of spermatogenesis. In females, Ovaries produce estrogen and progesterone, which regulate the menstrual cycle, control the development of female secondary sexual characteristics, and support pregnancy.
Exocrine function: Gonads release substances through ducts. In males, Testes release sperm through the vas deferens, which is part of the reproductive system. In females, Ovaries release ova which travel through the oviducts to the uterus.
So, the heterocrine nature of gonads involves their dual role in hormone secretion (endocrine) and the release of reproductive cells (exocrine), making them crucial for both the endocrine system and the reproductive system.
Pancreas
Endocrine function: This involves the secretion of hormones directly into the bloodstream. Pancreas produces hormones such as insulin and glucagon, which help regulate blood sugar level. Insulin is released when blood sugar levels are high, and it promotes the uptake of glucose by cells, reducing blood sugar (hypoglycemia). Glucagon is released when blood sugar levels are low, stimulating the liver to release glucose into the bloodstream, raising blood sugar levels (hyperglycemia).
Exocrine function: This involves the production and secretion of digestive enzymes. These enzymes are delivered into the small intestine through ducts. These enzymes play a crucial role in breaking down and digesting carbohydrates, proteins, and fats from the food.
In summary, pancreas as a heterocrine gland plays a vital role in regulating glucose homeostasis through its endocrine function and aids in digestion through its exocrine function by producing digestive enzymes.
Salivary glands
Exocrine function: The primary role of salivary glands is to produce and secrete saliva into the oral cavity through ducts. This secretion is vital for various digestive processes, including moistening food to aid in swallowing, breaking down complex carbohydrates through the enzyme amylase, and providing lubrication for speech and mastication. This exocrine function helps in the digestion and maintenance of oral health.
Endocrine function: Salivary glands can also release certain hormones or signaling molecules into the bloodstream, which have effects beyond the oral cavity. For example, they can release epidermal growth factor (EGF) and insulin-like growth factor (IGF), which play roles in cell growth and tissue repair.
In summary, salivary glands are classified as heterocrine glands because they have a dual role in both exocrine and endocrine functions. They primarily secrete saliva into the oral cavity for digestion, but they can also release specific hormones into the bloodstream with broader physiological effects.
Clinical significance
Diabetes mellitus: Malfunctions in the endocrine part of the pancreas can lead to diabetes, affecting insulin production and blood sugar regulation.
Digestive disorders: Disorders of heterocrine glands in the digestive system can result in conditions such as chronic pancreatitis and malabsorption syndromes.
References
Glands
Exocrine system
Endocrine system
Pancreas
Human anatomy | Heterocrine gland | [
"Biology"
] | 1,351 | [
"Exocrine system",
"Organ systems",
"Endocrine system"
] |
67,909,590 | https://en.wikipedia.org/wiki/Sphincter%20of%20Boyden | The sphincter of Boyden (also known as the choledochal sphincter) is a sphincter located in the common bile duct before it joins with the pancreatic duct to form the ampulla of vater. This sphincter controls the flow of bile into the pancreatic duct and it helps in filling up of the gallbladder with bile.
Structure
The sphincter of Boyden is a smooth muscle sphincter surrounding the common bile duct (ductus choledocus). It occurs just before the junction with the pancreatic duct, where the ampulla of Vater is formed. Occasionally, some fibres also surround the pancreatic duct.
It is subdivided into two parts - pars superior and pars inferior. The pars inferior is the strongest component of the sphincter of Oddi complex.
Function
The sphincter of Boyden controls the flow of bile from the common bile duct into the pancreatic duct. This helps with filling of the gallbladder with bile.
Its contractions regulate the passage of bile into the gall bladder or the duodenum.
History
This is named after the American anatomist Edward Allen Boyden (1886-1976).
References
Anatomy
Digestive system | Sphincter of Boyden | [
"Biology"
] | 258 | [
"Digestive system",
"Organ systems",
"Anatomy"
] |
67,910,073 | https://en.wikipedia.org/wiki/Rescuers%3A%20Portraits%20of%20Moral%20Courage%20in%20the%20Holocaust | Rescuers: Portraits of Moral Courage in the Holocaust is a 1992 book by Gay Block and Malka Drucker.
In 1986 rabbis Harold Schulweis, Malka Drucker and portrait artist Gay Block decided to document activities of non-Jewish Europeans who risked torture and death to save Jews during the Holocaust, a topic they considered both important and under-publicized. Their work would eventually led to a book (Rescuers: Portraits of Moral Courage in the Holocaust), as well as an exhibition of Block's photographs.
References
1992 non-fiction books
Books about the Holocaust
Rescue of Jews during the Holocaust | Rescuers: Portraits of Moral Courage in the Holocaust | [
"Biology"
] | 125 | [
"Rescue of Jews during the Holocaust",
"Behavior",
"Altruism"
] |
67,910,306 | https://en.wikipedia.org/wiki/List%20of%20organisms%20named%20after%20famous%20people%20%28born%20before%201800%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 before 1 January 1800. It also includes ensembles in which at least one member was born before that date; 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 were 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, writer Johann Wolfgang von Goethe).
Organisms named after famous people born later can be found in:
List of organisms named after famous people (born 1800–1899)
List of organisms named after famous people (born 1900–1949)
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 may be unavailable in the zoological sense or illegitimate in the botanical sense due to senior homonyms already having the same name.
List (people born before 1800)
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 1
Taxonomy (biology)
Organisms 1
Organisms 1
Organisms 1
Taxonomic lists | List of organisms named after famous people (born before 1800) | [
"Biology"
] | 472 | [
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists"
] |
67,910,317 | https://en.wikipedia.org/wiki/Leonhard%20Euler%20Gold%20Medal | The Leonhard Euler Gold Medal (Золотая медаль имени Леонарда Эйлера) is a medal named after the Swiss, German, and Russian mathematician Leonhard Euler, awarded by the Отделением математических наук (Branch of Mathematical Sciences of the Russian Academy of Sciences) for outstanding results in mathematics and physics. The medal was awarded once in 1957 to two scientists and since 1991 has been awarded every five years.
Laureates
1957 — Igor Kurchatov and Felix Frankl for outstanding results in mathematics and physics
1991 — Aleksandr Danilovich Aleksandrov for fundamental contributions to the development of mathematics
1997 — Yury Osipov for outstanding results in mathematics and physics
2002 — Ludvig Faddeev for outstanding results in mathematics and physics
2007 — Valery Vasilevich Kozlov for a series of papers on nonlinear Hamiltonian systems of differential equations
2012 — Sergei Novikov for his deep contribution to the application of topological methods in quantum physics
2017 — Igor Shafarevich for outstanding contributions to number theory and algebraic geometry
References
Academic awards
Leonhard Euler
Awards established in 1957
Science and technology in Russia
Science and technology awards
Russian science and technology awards
Russian Academy of Sciences
1957 establishments in Russia | Leonhard Euler Gold Medal | [
"Technology"
] | 287 | [
"Science and technology awards"
] |
67,910,349 | https://en.wikipedia.org/wiki/List%20of%20organisms%20named%20after%20famous%20people%20%28born%201950%E2%80%93present%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 the ICZN's International Code of Zoological Nomenclature, based on 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 on or after 1 January 1950. It also includes ensembles (including bands and comedy troupes) in which at least one member was born after that date; 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, rock musician Greg Graffin).
Organisms named after famous people born earlier can be found in:
List of organisms named after famous people (born before 1800)
List of organisms named after famous people (born 1800–1899)
List of organisms named after famous people (born 1900–1949)
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 may be unavailable in the zoological sense or illegitimate in the botanical sense due to senior homonyms already having the same name.
List (people born 1950–present)
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 1950
Taxonomy (biology)
Organisms 1950
Organisms 1950
Organisms 1950
Taxonomic lists | List of organisms named after famous people (born 1950–present) | [
"Biology"
] | 495 | [
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists"
] |
67,910,445 | https://en.wikipedia.org/wiki/Ethylene%20signaling%20pathway | Ethylene signaling pathway is a signal transduction in plant cells to regulate important growth and developmental processes. Acting as a plant hormone, the gas ethylene is responsible for promoting the germination of seeds, ripening of fruits, the opening of flowers, the abscission (or shedding) of leaves and stress responses. It is the simplest alkene gas and the first gaseous molecule discovered to function as a hormone.
Most of the understanding on ethylene signal transduction come from studies on Arabidopsis thaliana. Ethylene can bind to at least five different membrane gasoreceptors. Although structurally diverse, the ethylene gasoreceptors all exhibit similarity (homology) to two-component regulatory system in bacteria, indicating their common ancestry from bacterial ancestor. Ethylene binds to the gasoreceptors on the cell membrane of the endoplasmic reticulum. Although homodimers of the gasoreceptors are required for functional state, only one ethylene molecule binds to each dimer.
Unlike in other signal transductions, ethylene is the suppressor of its gasoreceptor activity. Ethylene gasoreceptors are active without ethylene due to binding with other enzymatically active co-gasoreceptors such as constitutive triple response 1 (CTR1) and ethylene insensitive 2 (EIN2). Ethylene binding causes EIN2 to split in two, of which the C-terminal portion of the protein can activate different transcription factors to bring about the effects of ethylene. There is also non-canonical pathway in which ethylene activates cytokinin gasoreceptor, and thereby regulate seed development (stomatal aperture) and growth of root (the apical meristem).
Ethylene gasoreceptors
Ethylene binds to it specific transmembrane gasoreceptor present on the cell membrane of endoplasmic reticulum. There are different ethylene gasoreceptor isoforms. Five isoforms are known in Arabidopsis thaliana which are named ethylene response/gasoreceptor 1 (ETR1), ethylene response sensor 1 (ERS1), ETR2, ERS2, and ethylene insensitive 4 (EIN4). The ETR1 is similar (conserved sequence) in different plants but with slight amino acid differences. A. thaliana gasoreceptors are classified into two subfamilies based on genetic relationship and common structural features, namely subfamily 1 that includes ETR1 and ERS1, and subfamily 2 that consists of ETR2, ERS2, and EIN4. In tomato there are seven types of ethylene gasoreceptors named SlETR1, SlETR2, SlETR3, SlETR4, SlETR5, SlETR6, and SlETR7 (Sl for Solanum lycopersicum, the scientific of tomato).
All ethylene gasoreceptors have similar organisation: a short N-terminal domain, three conserved transmembrane domains towards the N-terminus, followed by a GAF domain of unknown function, and then signal output motifs in the C-terminal region. The N-terminus is exposed on the lumen of the endoplasmic reticulum, and the C-terminus that is exposed to the cytoplasm of the cell. The N-terminus contains the sites for binding of ethylene, dimerization and membrane localization. Two similar gasoreceptors combine to form a homodimer through a disulfide bridge forming a cysteine-cysteine interaction. However, the main membrane localization is done by the transmembrane domain, which can also bind ethylene with the help of copper as a cofactor. Copper ion is supplied by a transmembrane protein responsive-to-antagonist 1 (RAN1) from antioxidant protein 1 (ATX1) via tiplin, or directly by copper transport protein.
Although the gasoreceptors are functionally active as dimers, only one copper ion binds to such dimer, indicating that one gasoreceptor dimer binds only one ethylene molecule. Mutations in the binding sites stop ethylene binding and also make plants insensitive to ethylene. Cys-65 in the protein helix 2 is particularly important as the binding site of copper ion as mutation in it stops copper and ethylene binding. The C-terminus is basically a bacterial two-component system with kinase activity and response regulator. ETR1 has histidine kinase activity, whereas ETR2, ERS2, and EIN4 have serine/threonine kinase activity, and ERS1 has both. The histidine kinase in ETR1 is not required for ethylene signaling.
Origin and evolution
Ethylene gasoreceptors are functionally similar to bacterial two-component system which has two activation sites named response regulator and histidine kinase. The cytoplasmic carboxy-terminal part of ethylene gasoreceptor is similar in amino acid sequence to these response regulator and histidine kinase in bacteria; although the N-terminal region is altogether different. Such genetic and protein relationships indicate that gasoreceptors and bacterial two-component gasoreceptors as well as phytochromes and cytokinin gasoreceptors in plants evolved from and were acquired by plants from a cyanobacterium that gave rise to plastids, the power organelles in plants and protists.
Phylogenetic analysis also shows the common origin of the ethylene gasoreceptor in plants and ethylene-binding domain in cyanobacteria. In 2016, Randy F. Lacey and Brad M. Binder at the University of Tennessee discovered that a cyanobacterium, Synechocystis sp. PCC 6803 response to ethylene signal and has a functional ethylene gasoreceptor, which they named Synechocystis Ethylene Response1 (SynEtr1). They further showed that SynEtr1 acts similar to plant ethylene gasoreceptor in binding ethylene, indicating the origin of ethylene gasoreceptor from Synechocystis-related cyanobacterium. The functional difference however is that kinase activity is not compulsory for ethylene binding in plants, but is the key role of SynEtr1.
Signal transduction
Two proteins are crucial for interacting ethylene with the gasoreceptors, namely constitutive triple response 1 (CTR1) and ethylene insensitive 2 (EIN2). CTR1 is a serine/threonine protein kinase that functions as a negative regulator of ethylene signalling. It is a member of the signaling protein mitogen-activated protein kinase (MAPK) kinase kinase. EIN2 is required for ethylene signalling and is part of the NRAMP (natural resistance-associated macrophage protein) family of metal transporters; it comprises a large, N-terminal portion containing multiple transmembrane domains (EIN2-N) in the ER membrane and a cytosolic C-terminal portion (EIN2-C). Other proteins such as reversion to ethylene sensitivity 1 (RTE1), cytochrome b5 and tetratricopeptide repeat protein 1 (TRP1) also play important roles in ethylene signaling. RTE1 is a highly conserved proteins in plants and protists but absent in fungi and prokaryotes. TRP1 is genetically related to transmembrane and coiled-coil protein 1 (TCC1) in animals that is involved F actin function and competes with Raf-1 for Ras binding.
Unlike in most signal transductions where the ligands activate their gasoreceptors to relay their signals, ethylene acts as the suppressor of its gasoreceptor, and the gasoreceptor being the negative regulator in ethylene responses. Ethylene gasoreceptor is active in the absence of ethylene. Without ethylene, the gasoreceptor binds to CTR1 at its C-terminal kinase domain. The kinase activity of CTR1 becomes activated and phosphorylates the neighbouring EIN2. As long as EIN2 remains highly phosphorylated, it remains inactive and there never is an ethylene signal relay. In ETR1, the gasoreceptor histidine kinase is required for binding with EIN2. RTE1 can bind to and activate ETR1 independent of CTR1. There is evidence that cytochrome b5 aids or acts similar to RTE1.
Ethylene binding to the gasoreceptor disrupts the EIN2 phosphorylation. It does not cause any particular change in the structural feature of the gasoreceptor-CTR1-EIN2 complex or stop the phosphorylation. In fact, at low level of ethylene there is increased gasoreceptor-CTR1-EIN2 complexes, which is then reduced as ethylene level rises. The turnover process is not yet fully understood. The only consequence of ethylene binding is reduced phosphorylation of EIN2. Under such condition EIN2 is activated and is cleaved to release EIN2-C from the membrane-bound EIN2-N portion. The enzyme that causes the cleavage is yet unknown. The role of EIN2-N is also unknown in A. thaliana. But in rice, its homologue OsEIN2-N (Os for Oryza sativa, the scientific name for rice) interacts with another protein, mao huzi 3 (MHZ3), a mutation of which gives rise to insensitivity to ethylene.
EIN2-C is the main component that mediates ethylene signal in the cell. It acts in two ways. In one, it binds the mRNAs that encode for EIN3-binding F-box proteins, EBF1 and EBF2 to cause their degradation. In another, it enters the nucleus to bind with EIN2 nuclear associated protein 1 (ENAP1) to regulate transcriptional and translational activities of EIN3 and the related EIL1 transcription factor to cause most of the ethylene responses.
References
Signal transduction
Plant hormones
Gaseous signaling molecules
Plant growth regulators
Plant physiology | Ethylene signaling pathway | [
"Chemistry",
"Biology"
] | 2,237 | [
"Plant physiology",
"Plants",
"Signal transduction",
"Gaseous signaling molecules",
"Biochemistry",
"Neurochemistry"
] |
67,910,765 | https://en.wikipedia.org/wiki/Hovlinc | Hovlinc RNA is a self-cleaving ribozyme of about 168 nucleotides found in a very long noncoding RNA (vlincRNA) in humans, chimpanzees, and gorillas. The word "hovlinc" comes from "hominin vlincRNA-located" RNA. Hovlinc is only a fourth known case of a ribozyme in human. Self-cleavage activity of Hovlinc has been shown in human, chimpanzees and bonobos, but is absent in gorillas, raising questions about Hovlinc's biological function and evolution.
There are only a few known examples of ribozymes in human, including Hovlinc, Mammalian CPEB3 ribozyme, Hammerhead ribozyme (HH9 and HH10) and B2 SINE ribozyme. Presumably Hovlinc acquired its self-cleaving activity about 10 to 13 million of years ago, which coincides with the last common ancestor of humans, gorillas, and chimpanzees. Hovlinc presents catalytic activity in hominids but not in gorillas where a mutation abolished the self-cleavage activity.
Hovlinc is a very structured RNA that contains four stem loops joined in a central loop, it also features large pseudoknots that help to bring together the second and fourth helices, which helps the RNA to get the more compacted structure that allows catalytic activity.
References
External links
Hovlinc family in Rfam
Ribozymes
Nucleotides
RNA
Genetics | Hovlinc | [
"Chemistry",
"Biology"
] | 336 | [
"Catalysis",
"Ribozymes",
"Genetics"
] |
67,911,196 | https://en.wikipedia.org/wiki/Bayesian%20learning%20mechanisms | Bayesian learning mechanisms are probabilistic causal models used in computer science to research the fundamental underpinnings of machine learning, and in cognitive neuroscience, to model conceptual development.
Bayesian learning mechanisms have also been used in economics and cognitive psychology to study social learning in theoretical models of herd behavior.
See also
Active learning
Bayesian learning
Cognitive acceleration
Cognitivism (learning theory)
Constructivist epistemology
Developmental psychology
Fluid and crystallized intelligence
Inquiry-based learning
Kohlberg's stages of moral development
Theory theory
References | Bayesian learning mechanisms | [
"Technology",
"Engineering"
] | 108 | [
"Artificial intelligence engineering",
"Computing stubs",
"Machine learning"
] |
67,911,641 | https://en.wikipedia.org/wiki/5GBioShield | The Bauer 5GBioShield, usually shortened to 5GBioShield, is a fraudulent device which was claimed to protect against radiation from 5G mobile networks. The device was invented by clinical pharmacist Jacques Bauer and former scientist Ilija Lakicevic and marketed by alternative medicine activist Sacha Stone. The product, which was sold for approximately £330 through an affiliate marketing scheme, was found to be composed of a normal USB thumb drive and a sticker. As of April 26, 2022, The official website is no longer online. British Trading Standards officials determined that the device was a scam.
Description
The manufacturers claim that:
The device is simply a common USB thumb drive containing marketing documents and usage instructions. The USB device is housed in a clear perspex block imprinted with a stylized version of St George slaying a dragon, as based on a medal originally made by William Wyon for Albert, Prince Consort.
Lakicevic, the co-inventor of the product, describes the device as containing a "new energy" embedded in a sticker, and that the USB stick is merely a carrier and need not be powered on to work. Lakicevic's claims regarding this product were published in an issue of the International Journal of Science and Research (ITNJ), a pay-to-publish science journal with no peer review processes in place.
Reception
The device was recommended in a report published by Glastonbury Town Council. Town councillor Toby R. Hall stated that the device could be "helpful" and "provide protection" due to a "wearable holographic nano-layer catalyser".
An analysis by Pen Test Partners, however, concluded that this device was nothing more than a 128 megabyte capacity generic USB thumb drive. The security firm concluded that the device "should [not] be promoted by publicly-funded bodies".
Following this report, the device was investigated by Trading Standards and found to be a scam and the matter had been referred to City of London Police Fraud Squad.
References
Conspiracy theories
Fraudulent detection devices
Quantum mysticism
Confidence tricks
Health fraud products
Alternative medicine | 5GBioShield | [
"Physics"
] | 434 | [
"Quantum mechanics",
"Quantum mysticism"
] |
67,912,270 | https://en.wikipedia.org/wiki/Ani%20Nenkova | Ani Nenkova is principal scientist at Adobe Research, currently on leave from her position as an associate professor of computer and information science at the University of Pennsylvania. Her research focuses on computational linguistics and artificial intelligence, with an emphasis on developing computational methods for analysis of text quality and style, discourse, affect recognition, and summarization.
Education
Nenkova earned her master's degree from the Department of Mathematical Logic and Applications (Faculty of Mathematics and Informatics) at Sofia University in Bulgaria. She then carried out doctoral work at Columbia University, where she was advised by Kathleen McKeown, earning a Ph.D. in computer science in 2006.
Career
Besides Nenkova’s position as an associate professor at the University of Pennsylvania, she also serves as a co-editor-in-chief of the Transactions of the Association for Computational Linguistics (TACL) and an area chair/senior program committee member for ACL, NAACL and AAAI. In the past, she has served as a member of the editorial board of Computational Linguistics (2009--2011), an associate editor for the IEEE/ACM Transactions on Audio, Speech and Language Processing (2015--2018), and a program co-chair for SIGDial 2014 and NAACL-HLT in 2016. In February of 2021, Nenkova started a new position at Adobe Research, joining the team as the head of the lab while on leave from Penn.
Research
Nenkova’s research interests include natural language processing, summarization, emotion recognition, and discourse. In the area of emotion recognition, Nenkova and her collaborators developed an approach that relies on regions of interest related to properties of phoneme or word classes, which served as a significant improvement over other approaches for representing speech in emotion recognition. In Nenkova’s research on hidden meanings, or what makes “great” writing, and literature search automation, she trains programs on word representation datasets that are curated by humans. These tell the computer what words and phrases mean in a specific context. The long-term goal of this research is to develop new algorithms that can analyze and understand new text without a human translator. Nenkova and her collaborators have also developed many tools and projects, including Speciteller, a tool for predicting sentence specificity, CATS, the corpus of science journalism articles used for their TACL 13 paper, and SIMetrix (Summary Input Similarity Metrics), a tool to perform the automatic summary evaluation in their EMNLP'09 and CL'14 papers.
Publications
Nenkova has over 150 publications.
Selected publications
Automatic Summarization Now Publishers 2011 ISBN 1601984707
Word Embeddings (Also) Encode Human Personality Stereotypes, Agarwal et al, *SEM@NAACL-HLT 2019.
How to Compare Summarizers Without Target Length? Pitfalls, Solutions and Re-Examination of the Neural Summarization Literature, Simeng Sun, Ori Shapira, Ido Dagan, Ani Nenkova, To appear at the Workshop on Methods for Optimizing and Evaluating Neural Language Generation at NAACL 2019.
Predicting Annotation Difficulty to Improve Task Routing and Model Performance for Biomedical Information Extraction, Yang et al, NAACL-HLT 2019.
A Corpus with Multi-Level Annotations of Patients, Interventions and Outcomes to Support Language Processing for Medical Literature, Nye et al, ACL 2018.
Combining Lexical and Syntactic Features for Detecting Content-Dense Texts in News, Yang and Nenkova, JAIR. 60: 179-219 (2017).
Fast and Accurate Prediction of Sentence Specificity, Li and Nenkova, AAAI 2015.
Prosodic cues for emotion: analysis with discrete characterization of intonation, Cao et al, Speech prosody, 2014.
References
External links
Year of birth missing (living people)
Living people
Columbia University alumni
Sofia University alumni
University of Pennsylvania Law School faculty
Computer scientists
Women computer scientists
21st-century Bulgarian scientists
Bulgarian women scientists
21st-century Bulgarian women scientists
University of Pennsylvania Department of Computer and Information Science faculty
Adobe Inc. people | Ani Nenkova | [
"Technology"
] | 848 | [
"Computer science",
"Computer scientists"
] |
58,422,881 | https://en.wikipedia.org/wiki/Anderson%E2%80%93Kadec%20theorem | In mathematics, in the areas of topology and functional analysis, the Anderson–Kadec theorem states that any two infinite-dimensional, separable Banach spaces, or, more generally, Fréchet spaces, are homeomorphic as topological spaces. The theorem was proved by Mikhail Kadec (1966) and Richard Davis Anderson.
Statement
Every infinite-dimensional, separable Fréchet space is homeomorphic to the Cartesian product of countably many copies of the real line
Preliminaries
Kadec norm: A norm on a normed linear space is called a with respect to a total subset of the dual space if for each sequence the following condition is satisfied:
If for and then
Eidelheit theorem: A Fréchet space is either isomorphic to a Banach space, or has a quotient space isomorphic to
Kadec renorming theorem: Every separable Banach space admits a Kadec norm with respect to a countable total subset of The new norm is equivalent to the original norm of The set can be taken to be any weak-star dense countable subset of the unit ball of
Sketch of the proof
In the argument below denotes an infinite-dimensional separable Fréchet space and the relation of topological equivalence (existence of homeomorphism).
A starting point of the proof of the Anderson–Kadec theorem is Kadec's proof that any infinite-dimensional separable Banach space is homeomorphic to
From Eidelheit theorem, it is enough to consider Fréchet space that are not isomorphic to a Banach space. In that case there they have a quotient that is isomorphic to A result of Bartle-Graves-Michael proves that then
for some Fréchet space
On the other hand, is a closed subspace of a countable infinite product of separable Banach spaces of separable Banach spaces. The same result of Bartle-Graves-Michael applied to gives a homeomorphism
for some Fréchet space From Kadec's result the countable product of infinite-dimensional separable Banach spaces is homeomorphic to
The proof of Anderson–Kadec theorem consists of the sequence of equivalences
See also
Notes
References
.
.
Topological vector spaces
Theorems in functional analysis
Theorems in topology | Anderson–Kadec theorem | [
"Mathematics"
] | 465 | [
"Theorems in mathematical analysis",
"Vector spaces",
"Topological vector spaces",
"Space (mathematics)",
"Theorems in topology",
"Theorems in functional analysis",
"Topology",
"Mathematical problems",
"Mathematical theorems"
] |
58,422,932 | https://en.wikipedia.org/wiki/V-sub%20x | V-sub x, also known as GD-7, is an organophosphate nerve agent of the V-series, the phosphonate analog of the organophosphate insecticide demeton. EA-5478 is the pinacolyl analogue.
See also
VX (nerve agent)
Demeton
References
V-series nerve agents
Phosphonothioates
Acetylcholinesterase inhibitors
Ethyl esters
Thioethers | V-sub x | [
"Chemistry"
] | 98 | [
"Phosphonothioates",
"Functional groups"
] |
58,423,453 | https://en.wikipedia.org/wiki/SigSpoof | SigSpoof () is a family of security vulnerabilities that affected the software package GNU Privacy Guard ("GnuPG") since version 0.2.2, that was released in 1998. Several other software packages that make use of GnuPG were also affected, such as Pass and Enigmail.
In un-patched versions of affected software, SigSpoof attacks allow cryptographic signatures to be convincingly spoofed, under certain circumstances. This potentially enables a wide range of subsidiary attacks to succeed.
References
Vulnerability
Computer security exploits | SigSpoof | [
"Technology"
] | 114 | [
"Computer security stubs",
"Computing stubs",
"Computer security exploits"
] |
58,423,880 | https://en.wikipedia.org/wiki/Industrial%20development%20in%20the%20Principality%20of%20Wallachia | Throughout the 1850s, the Principality of Wallachia underwent an industrial revolution which yielded, among others, the first oil refinery in the World. Six years after the first Wallachian industrial establishment was completed (1853), the country united with the Principality of Moldavia to form Romania.
Assan's steam mill
The first industrial establishment based on mechanized work and steam power was introduced in 1853, in the form of the Assan Steam Mill. The mill also carried out oil pressing and brandy distilling. Situated on the outskirts of Bucharest, it was founded by George Assan, using modern machinery from Vienna. Assan ran several pharmacies and wine shops which enabled him to purchase the machinery and build the mill. After Assan's death in 1866, the mill was taken over by his wife, Alexandrina. The facility changed hands again in 1884, when it was taken over by the Assans' sons. The mill remained active into the 20th century.
The world's first oil refinery
The most notable accomplishment of Wallachia's industrial revolution was the building of the World's first industrial oil refinery in 1856-1857. It was built by Teodor Mehedinţeanu. Situated at Râfov, near Ploiești, the refinery had a processing capacity of 7.5 tons per day. Two more important firsts resulted from this achievement. Wallachia (and by extension, Romania) became the first country in the world with an officially recorded crude oil production, 275 tons. Also in 1857, Bucharest became the first city in the world to use lamp oil for public illumination. The next two countries to record oil production were the United States and Italy in 1860.
Other establishments
Food industries developed at Brăila starting from the 1830s.
In 1855, a brick factory which employed the use of machinery was founded in Bucharest. It was a military asset, being run by the Cavalry commander Serdar Filipescu.
References
Industry in Romania
Oil refining
History of Wallachia | Industrial development in the Principality of Wallachia | [
"Chemistry"
] | 406 | [
"Petroleum technology",
"Oil refining"
] |
58,425,419 | https://en.wikipedia.org/wiki/Somnox%20Sleep%20Robot | The Somnox Sleep Robot is a capsule-shaped robot that claims to enhance quality of sleep. The capsule "breathes" in and out according to a fixed rhythm. The company claims that by subconsciously matching their breathing to it, people will be helped to fall asleep.
Description
The robot is a heavy, kidney-shaped white capsule with a soft fabric shell. It can be controlled with a smartphone through a companion app. In addition to breathing, it also plays customizable audio.
History
The robot began prototyping in 2015 at the Delft University of Technology in the Netherlands. It was originally made by four robotics engineers there to help themselves and their families fall asleep, and to help wean one of the designer's mothers suffering from anxiety and insomnia off of sleep medication. The decision was made to commercialize it after it received interest from strangers. It was released on Kickstarter in November 2017, raising about twice its funding goal of ().
Somnox launched a second version of their product line in November 2021, with WiFi and Bluetooth support as well as an improved spirometry algorithm.
See also
Sleep disorder
Sleep hygiene
White noise machine
References
Medical robots
Sleep medicine
Robots of the Netherlands | Somnox Sleep Robot | [
"Biology"
] | 251 | [
"Behavior",
"Sleep",
"Sleep medicine"
] |
58,425,437 | https://en.wikipedia.org/wiki/Accedian | Accedian was a Canadian company that developed network communication and application monitoring software and hardware. Headquartered in Montreal, Canada, the company was majority owned by Bridge Growth Partners, until its acquisition by Cisco in September 2023.
History
Accedian was founded by Patrick Ostiguy and 4 partners in 2004. The company originally developed service assurance hardware and software for telecommunications service providers, including mobile network operators. The first product was a backhaul networks interface device, which links cell towers to central offices. Accedian has since made network function virtualization and virtualized customer-premises equipment (V-CPE) products.
In March 2017, Accedian announced a US$100M investment by Bridge Growth Partners in return for a major equity stake.
In February 2018, Accedian announced that it had acquired Performance Vision of Paris, France for an undisclosed amount. Performance Vision developed network performance management and application performance management solutions. In 2020, Dion Joannou was CEO of Accedian.
In June 2023, Cisco announced its intent to acquire Accedian, and it completed the transaction in September of the same year.
Awards and recognition
In October 2011, Accedian was named on the Deloitte Fast 50 list of the fifty fastest growing technology companies in Canada.
In 2014, Accedian was named the fastest growing technology company in Canada with first place in the Deloitte Fast 50 list. Accedian placed second in Deloitte's Technology Fast 500 list for North America.
In February 2018, research firm Gartner named Accedian as a Magic Quadrant leader in the network performance monitoring and diagnostics (NPMD) category.
In 2021, Patrick Ostiguy was still executive chairman of Accedian Networks Inc.
References
Companies based in Montreal
System administration
Network management
Canadian companies established in 2004
2004 establishments in Quebec | Accedian | [
"Technology",
"Engineering"
] | 375 | [
"Information systems",
"Computer networks engineering",
"Network management",
"System administration"
] |
58,425,998 | https://en.wikipedia.org/wiki/Deniss%20%C4%8Calovskis | Deniss Čalovskis (born 1985 in Riga, Latvian SSR, Soviet Union) is a Latvian computer hacker. He is the creator of the Gozi virus. Calovskis is a certified Data Protection Officer (DPO).
Hacker
In February 2015, Deniss Čalovskis was extradited to the U.S. from Latvia to face 67 years in prison.
In September 2015, Čalovskis pleaded guilty to conspiring to commit computer intrusions. On January 5, 2016, he sentenced to time served after spending over 20 months in Latvian and American jails.
The Gozi virus was prevalent between 2005 and 2012, infecting between 17,000 and 40,000 computers including some at NASA. Financial losses from the virus stand "at a minimum, millions of dollars", according to the indictment.
In August 2014, Čalovskis began working at the Latvian Medical Association. Čalovskis started several social nonprofit projects for the local community in Latvia.
References
1985 births
Living people
People from Riga
Cybercriminals
Hackers
Latvian criminals | Deniss Čalovskis | [
"Technology"
] | 222 | [
"Lists of people in STEM fields",
"Hackers"
] |
58,429,162 | https://en.wikipedia.org/wiki/Dawn%20Sumner | Dawn Yvonne Sumner is an American geologist, planetary scientist, and astrobiologist. She is a professor at the University of California, Davis. Sumner's research includes evaluating microbial communities in Antarctic lakes, exploration of Mars via the Curiosity rover, and characterization of microbial communities in the lab and from ancient geologic samples. She is an investigator on the NASA Mars Science Laboratory (MSL) and was Chair of the UC Davis Department of Earth & Planetary Sciences from 2014 to 2016. She is Fellow of the Geological Society of America.
Early life and education
Sumner was born near Seattle, Washington, and spent part of her childhood on the Yakama Indian Reservation in the Pacific Northwest. From there, she earned a B.S. with Honors in geology from the California Institute of Technology (Caltech), then attended the Massachusetts Institute of Technology for her Ph.D. which she completed in 1995. Sumner then returned Caltech for postdoctoral research, supported by an O.K. Earl Postdoctoral Fellowship.
Career
Ancient Microbial Communities is part of Sumner's research which includes understanding microbial evolution and ecology and Earth history through microbial signatures in the rock record. Her publications feature new developments in how to interpret ancient biological responses to environmental factors, tracing oxygenation and the impact on carbonate microbial biological signatures. Sumner has also studied carbon isotopes of specific carbonates in order to find evidence of life.
Antarctic Lakes Sumner's research utilizes Antarctic lakes as a model system for understanding microbial processes, early oxygenic photosynthesis, and life on other planets. This work includes the discovery of pinnacles of microbial growth under ice-covered lakes and describes multiple microbial communities involved in the development of these features. Similar features in another Antarctic lake appear to record changes in the lake environment, including sea level, through time.
Exploration of Mars and its Environments Professor Sumner's research with the Mars Science Laboratory has generated over three dozen collaborative publications and helped uncover evidence of ancient lakes on Mars. Sumner's research has established that parts of ancient Mars could have hosted life as we know it on Earth, and contributed to the discovery of organic molecules on Mars. As a geologist, Sumner applies many of the same principles that would be used on earth, such as stratigraphy and geochemistry, to the Martian environment. Sumner is a MSL “long term planner”, one of several lead geoscientists amongst more than five hundred scientists not directly employed by NASA on this project. Sumner was involved in the creation of a geological map of Gale crater, and selecting the landing site of Curiosity. Sumner was partially responsible for the assignment of daily operations to fit the long-term missions goals. and also involved in future planning for additional Mars exploration, including a mission in 2020.
Neoarchean Geological Time Period is a part of Professor Sumner's research that has been accumulated in South Africa. Sumner has studied the precipitation of multiple elements including carbonate and aragonite. This research has led Sumner to develop new understandings of the oceans pH in Neoarchean time period which can lead to discoveries in the changes of the oceans pH through time. Sumner's conducted this research using methods of stratigraphy and petrography.
Awards and honors
Sumner was elected a Fellow of the Geological Society of America in 2014. Also in 2014, she was selected to deliver the honorary Carl Sagan Lecture at the American Geophysical Union. In 2016, Sumner was awarded the Career Award for Outstanding Contributions in Geosciences, Geobiology and Microbiology from the Geological Society of America. Sumner also received the distinguished career award from the University of California, Davis 2016: for extensive research in microbiology, geochemistry, and research in the exploration of mars over her career. More recently, Sumner's was one of 14 selected to become a fellow of the California Academy of Sciences for her contributions to the study of microbial sciences.
Equality and sexual harassment in science
Sumner is the author of a widely used anti-harassment statement that she made public so that other universities and institutes could use it as a model. A leader in helping institutions develop anti-harassment plans, Sumner presented to a workshop at the 2016 American Geophysical Union on “Addressing harassment and improving workplace climate.” She was also an invited presenter for Association of Polar Early Career Scientists webinar on sexual harassment during fieldwork. Sumner is presently chair of advisory board for The Feminist Research Institute at the UC, Davis In June 2020 she became the leader of the Anti-Racism Action Committee in her department (Earth and Planetary Science) at UC Davis. Sumner also wrote four letters concerning racism and its effects on the science community between late May and early June 2020
Selected publications
DAWN Y. SUMNER; Biology and Geology: A Necessary Symbiosis. PALAIOS 2002; 17 (4): 307–308.
Outreach
Sumner has presented lectures to public and school groups, and she has participated in videos and films on exploring Mars. These have included presentations at Sierra College, a Northern California Rotary Club, and Sacramento State University's Science in the River City. She appeared in several videos on Mars exploration, including ones hosted by UC Davis and in the Finnish documentary film “The Other Side of Mars”.
Dawn Sumner's research has been covered in local and national media outlets, including Popular Science, Wired Magazine, KPCC public radio, the television series Take Part, and the BBC.
See also
Extremophiles
Astrobiology
Paleobiology
Jet Propulsion Laboratory
John Grotzinger
Lake Untersee
Lake Vanda
Gale Crater
Geology
Curiosity Rover
Microbiology
References
External links
Sumner video interview on Curiosity rover
Sumner profile at UC Davis
Sumner Antarctic blog
Living people
American Antarctic scientists
American geologists
American women geologists
Women Antarctic scientists
University of California, Davis faculty
Year of birth missing (living people)
Massachusetts Institute of Technology alumni
California Institute of Technology alumni
Geochemistry
21st-century American women | Dawn Sumner | [
"Chemistry"
] | 1,190 | [
"nan"
] |
58,429,169 | https://en.wikipedia.org/wiki/Tim%20Peters%20%28software%20engineer%29 | Tim Peters is a software developer who is known for creating the Timsort hybrid sorting algorithm and for his major contributions to the Python programming language and its original CPython implementation. A pre-1.0 CPython user, he was among the group of early adopters who contributed to the detailed design of the language in its early stages.
He later created the Timsort algorithm (based on earlier work on the use of "galloping" search) which is used in Python since version 2.3 (since version 3.11 using the Powersort merge policy instead of Timsort's original merge policy), as well as in other widely used computing platforms, including the V8 JavaScript engine powering the Google Chrome and Chromium web browsers, as well as Node.js. He has also contributed the doctest and timeit modules to the Python standard library.
Peters also wrote the Zen of Python, intended as a statement of Python's design philosophy, which was incorporated into the official Python literature as Python Enhancement Proposal 20 and in the Python interpreter as an easter egg. He contributed the chapter on algorithms to the Python Cookbook. From 2001 to 2014 he was active as a member of the Python Software Foundation's board of directors. Peters was an influential contributor to Python mailing lists. He is also a highly ranked contributor to Stack Overflow, mostly for answers relating to Python.
Peters' past employers include Kendall Square Research.
Tim Peters was granted the Python Software Foundation's Distinguished Service Award for 2017.
See also
History of Python
References/Notes and references
External links
PyCon 2006 interview with Tim Peters
Stack Overflow user page
PythonLabs.com
Python (programming language) people
American computer programmers
Free software programmers
Living people
Place of birth missing (living people)
Year of birth missing (living people) | Tim Peters (software engineer) | [
"Technology"
] | 373 | [
"Computing stubs",
"Computer specialist stubs"
] |
58,431,337 | https://en.wikipedia.org/wiki/HAT%20transposon | hAT transposons are a superfamily of DNA transposons, or Class II transposable elements, that are common in the genomes of plants, animals, and fungi.
Nomenclature and classification
Superfamilies are identified by shared DNA sequence and ability to respond to the same transposase. Common features of hAT transposons include a size of 2.5-5 kilobases with short terminal inverted repeats and short flanking target site duplications generated during the transposition process.
The hAT superfamily's name derives from three of its members: the hobo element from Drosophila melanogaster, the Activator or Ac element from Zea mays, and the Tam3 element from Antirrhinum majus. The superfamily has been divided based on bioinformatics analysis into at least two clusters defined by their phylogenetic relationships: the Ac family and the Buster family. More recently, a third group called Tip has been described.
Family members
The hAT transposon superfamily includes the first transposon discovered, Ac from Zea mays (maize), first reported by Barbara McClintock. McClintock was awarded the Nobel Prize in Physiology or Medicine in 1983 for this discovery. The family also includes a subgroup known as space invaders or SPIN elements, which have very high copy numbers in some genomes and which are among the most efficient known transposons. Although no extant active example is known, laboratory-generated consensus sequences of active SPIN elements are able to generate high copy numbers when introduced to cells from a wide range of species.
Distribution
hAT transposons are widely distributed across eukaryotic genomes, but are not active in all organisms. Inactive hAT transposon sequences are present in mammal genomes, including the human genome; they are among the transposon families believed to have been present in the ancestral vertebrate genome. Among mammals, the genome of the little brown bat Myotis lucifugus is notable for its relatively high and recently acquired number of inactive hAT transposons.
The distribution of SPIN elements is patchy and does not relate well to known phylogenetic relationships, prompting suggestions that these elements may have spread through horizontal gene transfer.
Domestication
Transposons are said to be exapted or "domesticated" when they have acquired functional roles in the host genome. Several sequences evolutionarily related to the hAT family have been exapted in diverse organisms, including Homo sapiens. An example is the ZBED gene family, which encode a group of zinc finger-containing regulatory proteins.
References
Mobile genetic elements | HAT transposon | [
"Biology"
] | 527 | [
"Molecular genetics",
"Mobile genetic elements"
] |
58,431,579 | https://en.wikipedia.org/wiki/K1839 | К1839 is a microprocessor chipset developed between 1984 and 1989 at the Angstrem Research Institute by the same team that developed the 1801BMx series of CPUs. It was the first Soviet, and later the first Russian 32-bit microprocessor system. From a programmer's point of view, it was a complete replica of the VAX 11/750 Comet and unlike the MicroVAX microprocessors produced by DEC, it included floating-point arithmetic. The chipset included a processor, a coprocessor for integer and floating-point arithmetic, a memory controller, and a bus adapter. It was fabricated in a 3 μm process. The Electronika-32 computer and a VAX-PC board were built based on this chipset, as well as the aerospace on-board digital computer SB3541 (developed by LNPOEA - OKB "Electroavtomatika", St. Petersburg). The 1839 chipset is still in production, and is used in the control systems of the GLONASS-M satellites.
The processor had external microprogram control. In other words, in addition to the CPU, a separate ROM was required (1839RE1 for special equipment or any 16kW 32-bit ROM with the appropriate cycle time). However, this does not mean that the instruction set could be modified arbitrarily since the instruction decoder was included in the circuitry of the CPU.
According to posts on the FidoNet forum MO.DEC, the arithmetic coprocessor was originally released with errors, and it was not always possible to run software written for the VAX. To circumvent this, updated microprograms were released to emulate the coprocessor functions in microcode on the CPU. Bug fixed chips were introduced at the Comtek'93 exhibition.
Chipset
L1839VM1 () — The central processor.
The VAX-11 instruction set includes 304 instructions, 21 addressing modes, 8/16/32/64 bits of data, 32 bit machine word, 16 GPRs (general purpose registers) and hardware support for multitasking and virtual memory. Virtual addressing is 32-bit, the physical address bus is 24 bits wide and the data bus is 32 bits wide.
Frequency 10 MHz and consisted of 150,000 transistors. Register/register addition takes 2 cycles or 0.2 μs, and memory access 0.6 μs.
L1839VM2 () – Arithmetic and Floating point coprocessor.
252 instructions, 8/16/32/64 bits integers, floating point F / D / G formats, and 24 bit addressing.
Frequency 10 MHz. Integer multiply 0.8 μs, floating point multiply 1.5 μs.
L1839VT1 () – DRAM and cache controller.
Supports 256 kbit and 1 Mbit DRAMs.
Frequency 10 MHz. DRAM word access time 800ns, cache access time of 200ns.
L1839VT2 () – SRAM controller
Supports 8/16/32 bit data words and 24 bit addresses.
Frequency 10 MHz. 200-400ns memory access time, parity or Hamming error correction.
L1839VV1 () – 32-bit/Q-bus host adaptor and interrupt controller.
Q-bus 8/16 bit accesses, 18 bit addresses
32-bus 8/16/32 bit accesses, 24 bit addresses
18 vector interrupts, and 4 interrupt priority levels.
Frequency 10 MHz.
N1839RE1A/B () – Microprogram ROM
16kW 32-bit word mask ROM.
Frequency 10 MHz. Access time 180ns.
N1839VZh2 () – 8-bit majority gate
The majority (two of the three) bi-directional inputs with bit-wise control and diagnostics
20ns cycle time.
See also
Soviet integrated circuit designation
List of Soviet microprocessors
References
External links
The chips of the kit on the site "Museum of Electronic Rarities"
Technical specification on the manufacturer's website
32-bit microprocessors
Computing in the Soviet Union | K1839 | [
"Technology"
] | 865 | [
"Computing in the Soviet Union",
"History of computing"
] |
58,431,700 | https://en.wikipedia.org/wiki/List%20of%20ITS%20associations | This is a list of ITS (intelligent transportation systems) associations.
ITS organisations are present worldwide. The work of these associations is often supported by local governments
The estimated worth of the market is US$9.6 Billion (2014–2015 In 2015, the intelligent transportation system (ITS) market in roadways was valued at US$20.94 billion
ITS organisations
Africa
ITS Africa with the regional members
ITS Ethiopia
ITS Nigeria
ITS South Africa
Americas
ITS Argentina
ITS America
ITS Brasil
ITS Canada
ITS Chile
ITS Colombia
ITS México
Asia
ITS Israel
ITS Turkey is member of ERTICO, the European organisation
Asia Pacific
ITS Asia-Pacific with the regional members
ITS Australia
ITS China
ITS Hongkong
ITS Japan
ITS Indonesia assisted by the Japan International Cooperation Agency (JICA)
ITS Korea
ITS Malaysia
ITS New Zealand
ITS Singapore
ITS Taiwan
ITS Thailand
Europe
In Europe the European Union, by the European Commission through financial instruments and through legislative instruments are supported innovative projects in IST directly as well by the regional ITS.
ITS Europe is represented by ERTICO
ITS Belgium.
ITS Denmark
ITS France
ITS Deutschland
ITS Hellas
ITS Italia
RDW Netherlands
ITS-Norge
ITS Polska
ITS России
ITS España
ITS Sverige
See also
List of countries by motor vehicle production
External links
References
Institution of Engineering and Technology | List of ITS associations | [
"Engineering"
] | 256 | [
"Institution of Engineering and Technology"
] |
58,432,047 | https://en.wikipedia.org/wiki/Particle%20chauvinism | Particle chauvinism is the term used by British astrophysicist Martin Rees to describe the (allegedly erroneous) assumption that what we think of as normal matter – atoms, quarks, electrons, etc. (excluding dark matter or other matter) – is the basis of matter in the universe, rather than a rare phenomenon.
Dominance of dark matter
With the growing recognition in the late 20th century of the presence of dark matter in the universe, ordinary baryonic matter has come to be seen as something of a cosmic afterthought.
As J.D. Barrow put it:
"This would be the final Copernican twist in our status in the material universe. Not only are we not at the center of the universe: We are not even made of the predominant form of matter."
The 21st century saw the share of baryonic matter in the total mass-energy of the universe downgraded further, to perhaps as low as 1%,
further extending what has been called the demise of particle-chauvinism,
before being revised up to some 5% of the contents of the universe.
See also
Anthropic principle
Carbon chauvinism
Mediocrity principle
References
External links
Astronomical hypotheses
Chauvinism
Exceptionalism
Dark matter | Particle chauvinism | [
"Physics",
"Astronomy"
] | 265 | [
"Dark matter",
"Astronomical hypotheses",
"Unsolved problems in astronomy",
"Concepts in astronomy",
"Unsolved problems in physics",
"Astronomical controversies",
"Exotic matter",
"Physics beyond the Standard Model",
"Matter"
] |
58,432,548 | https://en.wikipedia.org/wiki/Maurice%20Sion | Maurice Sion (17 October 1927, Skopje – 17 April 2018, Vancouver) was an American and Canadian mathematician, specializing in measure theory and game theory. He is known for Sion's minimax theorem.
Biography
Sion received from New York University his B.A. in 1947 and his M.A. in 1948. He received from the University of California, Berkeley in 1951 his Ph.D. under the supervision of Anthony Morse with thesis On the existence of functions having given partial derivatives on Whitney's curve. Sion was a member of the mathematics faculty at U.C. Berkeley until 1960, when he immigrated to Canada with his wife Emilie and his two children born in the U.S.A. (His two younger children were born in Canada.) From 1960 until he retired in 1989, Maurice Sion was a professor of mathematics at the University of British Columbia. For two academic years from 1957 to 1959 and in the autumn of 1962 he was at the Institute for Advanced Study. He wrote several books on mathematics and served for many years as the head of the University of British Columbia's mathematics department. In 1957 he was the coauthor with Philip Wolfe of a paper with an example of a zero-sum game without a minimax value. Sion was an Invited Speaker at the International Congress of Mathematicians (ICM) in 1970 in Nice and was appointed the Main Organizer for the ICM held in Vancouver in 1974. In 2012 he was elected a Fellow of the American Mathematical Society.
Sion was fluent in Spanish, Italian, French, and English.
He was predeceased by his youngest child. Upon his death he was survived by his widow, three children, and six grandchildren.
Selected publications
Articles
with R. C. Willmott:
Books
References
1927 births
2018 deaths
People from Skopje
New York University alumni
University of California, Berkeley alumni
Academic staff of the University of British Columbia
American people of Sephardic-Jewish descent
20th-century American mathematicians
21st-century American mathematicians
20th-century Canadian mathematicians
21st-century Canadian mathematicians
Mathematical analysts
Measure theorists
Fellows of the American Mathematical Society | Maurice Sion | [
"Mathematics"
] | 429 | [
"Mathematical analysis",
"Mathematical analysts"
] |
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