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El Gordo is a massive interacting galaxy cluster in the early Universe (). The extreme properties of El Gordo in terms of its redshift, mass, and the collision velocity leads to strong () tension with the ΛCDM model. The properties of El Gordo are however consistent with cosmological simulations in the framework of MON... | Lambda-CDM model | Wikipedia | 454 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
Early- (e.g. from CMB data collected using the Planck observatory) and late-time (e.g. measuring weak gravitational lensing events) facilitate increasingly precise values of . However, these two categories of measurement differ by more standard deviations than their uncertainties. This discrepancy is called the tensio... | Lambda-CDM model | Wikipedia | 389 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
The ΛCDM model assumes that the strong equivalence principle is true. However, in 2020 a group of astronomers analyzed data from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample, together with estimates of the large-scale external gravitational field from an all-sky galaxy catalog. They concluded that... | Lambda-CDM model | Wikipedia | 512 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
High-velocity galaxy problem
Galaxies in the NGC 3109 association are moving away too rapidly to be consistent with expectations in the ΛCDM model. In this framework, NGC 3109 is too massive and distant from the Local Group for it to have been flung out in a three-body interaction involving the Milky Way or Andromeda ... | Lambda-CDM model | Wikipedia | 411 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
Existence of surprisingly massive galaxies in the early universe challenges the preferred models describing how dark matter halos drive galaxy formation. It remains to be seen whether a revision of the Lambda-CDM model with parameters given by Planck Collaboration is necessary to resolve this issue. The discrepancies c... | Lambda-CDM model | Wikipedia | 420 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
Extended models allow one or more of the "fixed" parameters above to vary, in addition to the basic six; so these models join smoothly to the basic six-parameter model in the limit that the additional parameter(s) approach the default values. For example, possible extensions of the simplest ΛCDM model allow for spatial... | Lambda-CDM model | Wikipedia | 309 | 985963 | https://en.wikipedia.org/wiki/Lambda-CDM%20model | Physical sciences | Physical cosmology | Astronomy | vital_articles |
In condensed matter physics, the Fermi surface is the surface in reciprocal space which separates occupied electron states from unoccupied electron states at zero temperature. The shape of the Fermi surface is derived from the periodicity and symmetry of the crystalline lattice and from the occupation of electronic en... | Fermi surface | Wikipedia | 402 | 986096 | https://en.wikipedia.org/wiki/Fermi%20surface | Physical sciences | Crystallography | Physics | vital_articles |
The linear response of a metal to an electric, magnetic, or thermal gradient is determined by the shape of the Fermi surface, because currents are due to changes in the occupancy of states near the Fermi energy. In reciprocal space, the Fermi surface of an ideal Fermi gas is a sphere of radius
,
determined by the vale... | Fermi surface | Wikipedia | 462 | 986096 | https://en.wikipedia.org/wiki/Fermi%20surface | Physical sciences | Crystallography | Physics | vital_articles |
Experimental determination
Electronic Fermi surfaces have been measured through observation of the oscillation of transport properties in magnetic fields , for example the de Haas–van Alphen effect (dHvA) and the Shubnikov–de Haas effect (SdH). The former is an oscillation in magnetic susceptibility and the latter in ... | Fermi surface | Wikipedia | 383 | 986096 | https://en.wikipedia.org/wiki/Fermi%20surface | Physical sciences | Crystallography | Physics | vital_articles |
With positron annihilation it is also possible to determine the Fermi surface as the annihilation process conserves the momentum of the initial particle. Since a positron in a solid will thermalize prior to annihilation, the annihilation radiation carries the information about the electron momentum. The corresponding e... | Fermi surface | Wikipedia | 226 | 986096 | https://en.wikipedia.org/wiki/Fermi%20surface | Physical sciences | Crystallography | Physics | vital_articles |
A hair dryer (the handheld type also referred to as a blow dryer) is an electromechanical device that blows ambient air in hot or warm settings for styling or drying hair. Hair dryers enable better control over the shape and style of hair, by accelerating and controlling the formation of temporary hydrogen bonds within... | Hair dryer | Wikipedia | 434 | 986413 | https://en.wikipedia.org/wiki/Hair%20dryer | Technology | Household appliances | null | vital_articles |
Since the 1920s, development of the hair dryer has mainly focused on improving the wattage and superficial exterior and material changes. In fact, the mechanism of the dryer has not had any significant changes since its inception. One of the more important changes for the hair dryer is to be made of plastic, so that it... | Hair dryer | Wikipedia | 471 | 986413 | https://en.wikipedia.org/wiki/Hair%20dryer | Technology | Household appliances | null | vital_articles |
Many of these dryers have "normal mode" buttons that turn off the heater and blow room-temperature air while the button is pressed. This function helps to maintain the hairstyle by setting it. The colder air reduces frizz and can help to promote shine in the hair.
Many feature "ionic" operation, to reduce the build-up... | Hair dryer | Wikipedia | 510 | 986413 | https://en.wikipedia.org/wiki/Hair%20dryer | Technology | Household appliances | null | vital_articles |
A drug test (also often toxicology screen or tox screen) is a technical analysis of a biological specimen, for example urine, hair, blood, breath, sweat, or oral fluid/saliva—to determine the presence or absence of specified parent drugs or their metabolites. Major applications of drug testing include detection of the ... | Drug test | Wikipedia | 472 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Breath air for the most part mimics blood tests as well. Due to the very low levels of substances in the breath air, liquid chromatography—mass spectrometry has to be used to analyze the sample according to a recent publication wherein 12 analytes were investigated.
Rapid oral fluid products are not approved for use i... | Drug test | Wikipedia | 448 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
When an employer requests a drug test from an employee, or a physician requests a drug test from a patient, the employee or patient is typically instructed to go to a collection site or their home. The urine sample goes through a specified 'chain of custody' to ensure that it is not tampered with or invalidated through... | Drug test | Wikipedia | 421 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Employment-related test results are relayed to a medical review office (MRO) where a medical physician reviews the results. If the result of the screen is negative, the MRO informs the employer that the employee has no detectable drug in the urine, typically within 24 hours. However, if the test result of the immunoass... | Drug test | Wikipedia | 455 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Hair analysis to detect addictive substances has been used by court systems in the United States, United Kingdom, Canada, and other countries worldwide. In the United States, hair testing has been accepted in court cases as forensic evidence following the Frye Rule, the Federal Rules of Evidence, and the Daubert Rule. ... | Drug test | Wikipedia | 509 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Alcohol
In contrast to other drugs consumed, alcohol is deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reac... | Drug test | Wikipedia | 448 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are not significantly affected by such treatments (Hartwig et al., 2003a). FAEE concentrations in hair from other body sites can be interpreted in a similar fashion as scalp... | Drug test | Wikipedia | 510 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Saliva drug screen / Oral fluid-based drug screen
Saliva / oral fluid-based drug tests can generally detect use during the previous few days. It is better at detecting very recent use of a substance. THC may only be detectable for 2–24 hours in most cases. On site drug tests are allowed per the Department of Labor.
De... | Drug test | Wikipedia | 428 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Random drug testing
Can occur at any time, usually when the investigator has reason to believe that a substance is possibly being used by the subject by behavior or immediately after an employee-related incident occurs during work hours. Testing protocol typically conforms to the national medical standard, candidates a... | Drug test | Wikipedia | 399 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Occupational harm reduction strategies
Drug and alcohol impairment while at work increases the risk of work-place accidents and decreases productivity. Employers such as the commercial driving and airline industry may conduct random drug tests on employees with the goal of deterring use to improve safety. There is some... | Drug test | Wikipedia | 478 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
After a suspected positive sample is detected during screening, the sample is tested using a confirmation test. Samples that are negative on the screening test are discarded and reported as negative. The confirmation test in most laboratories (and all SAMHSA certified labs) is performed using mass spectrometry, and is ... | Drug test | Wikipedia | 466 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
There are also some disadvantages to spray or sweat testing. There is not much variety in these drug tests, only a limited number of drugs can be detected, prices tend to be higher, and inconclusive results can be produced by variations in sweat production rates in donors. They also have a relatively long specimen col... | Drug test | Wikipedia | 475 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
Although thousand different substances can be determined in a single gas chromatography–mass spectrometry or liquid chromatography–mass spectrometry experiment, due to the low concentration of analytes, practical measurements (see selective ion monitoring) are limited to a smaller number (10-20) of analytes. Designer d... | Drug test | Wikipedia | 505 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
United Kingdom
A study in 2004 by the Independent Inquiry into Drug Testing at Work found that attempts by employers to force employees to take drug tests could potentially be challenged as a violation of privacy under the Human Rights Act 1998 and Article 8 of the European Convention of Human Rights. However, this doe... | Drug test | Wikipedia | 425 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
According to Henriksson, the anti-drug appeals of the Reagan administration "created an environment in which many employers felt compelled to implement drug testing programs because failure to do so might be perceived as condoning drug use. This fear was easily exploited by aggressive marketing and sales forces, who of... | Drug test | Wikipedia | 485 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
In Victoria, roadside saliva tests detect drugs that contain:
THC (Delta-9 tetrahydrocannabinol), the active component in cannabis.
methamphetamine, also known as "ice", "crystal" and "crank".
MDMA (Methylenedioxymethamphetamine), which is known as ecstasy.
In February 2016 a New South Wales magistrate "acquitted a... | Drug test | Wikipedia | 370 | 986871 | https://en.wikipedia.org/wiki/Drug%20test | Biology and health sciences | Diagnostics | Health | vital_articles |
The Siberian Traps () are a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last years.
The eruptions continued for roughly two million years and spanned the Permian–Triassic bound... | Siberian Traps | Wikipedia | 419 | 987039 | https://en.wikipedia.org/wiki/Siberian%20Traps | Physical sciences | Geologic features | Earth science | vital_articles |
The main source of rock in this formation is basalt, but both mafic and felsic rocks are present, so this formation is officially called a Flood Basalt Province. The inclusion of mafic and felsic rock indicates multiple other eruptions that occurred and coincided with the one-million-year-long set of eruptions that cre... | Siberian Traps | Wikipedia | 508 | 987039 | https://en.wikipedia.org/wiki/Siberian%20Traps | Physical sciences | Geologic features | Earth science | vital_articles |
Palaeontological evidence further indicates that the global distribution of tetrapods vanished between latitudes approximating 40° south to 30° north, with very rare exceptions in the region of Pangaea that is today Utah. This tetrapod gap of equatorial Pangaea coincides with an end-Permian to Middle Triassic global "c... | Siberian Traps | Wikipedia | 439 | 987039 | https://en.wikipedia.org/wiki/Siberian%20Traps | Physical sciences | Geologic features | Earth science | vital_articles |
To further the connection with the Permian–Triassic extinction event, other disastrous events occurred around the same time period, such as sea level changes, meteor impacts and volcanism. Specifically focusing on volcanism, rock samples from the Siberian Traps and other southern regions were obtained and compared. Bas... | Siberian Traps | Wikipedia | 410 | 987039 | https://en.wikipedia.org/wiki/Siberian%20Traps | Physical sciences | Geologic features | Earth science | vital_articles |
"NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response" is a standard maintained by the U.S.-based National Fire Protection Association. First "tentatively adopted as a guide" in 1960, and revised several times since then, it defines the "Safety Square" or "Fire Diamond" wh... | NFPA 704 | Wikipedia | 501 | 987544 | https://en.wikipedia.org/wiki/NFPA%20704 | Physical sciences | Basics: General | Chemistry | vital_articles |
The Charlotte Fire Department developed training to respond to fires involving hazardous materials, ensured that protective clothing was available to those responding, and expanded the fire prevention inspection program. Fire Marshal J. F. Morris developed the diamond shaped placard as a marking system to indicate when... | NFPA 704 | Wikipedia | 74 | 987544 | https://en.wikipedia.org/wiki/NFPA%20704 | Physical sciences | Basics: General | Chemistry | vital_articles |
The Harmattan is a season in West Africa that occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara over West Africa into the Gulf of Guinea. The name is related to the word in the Twi language. The t... | Harmattan | Wikipedia | 501 | 987546 | https://en.wikipedia.org/wiki/Harmattan | Physical sciences | Seasons | Earth science | vital_articles |
Humidity can drop lower than 15%, which can result in spontaneous nosebleeds for some people. Other health effects on humans may include conditions of the skin (dryness of the skin), dried or chapped lips, eyes, and respiratory system, including aggravation of asthma. | Harmattan | Wikipedia | 59 | 987546 | https://en.wikipedia.org/wiki/Harmattan | Physical sciences | Seasons | Earth science | vital_articles |
In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving resource conflicts. The term "plug and play" has since been expanded to a wide ... | Plug and play | Wikipedia | 498 | 158859 | https://en.wikipedia.org/wiki/Plug%20and%20play | Technology | Computer hardware | null | vital_articles |
MSX
The MSX system, released in 1983, was designed to be plug and play from the ground up, and achieved this by a system of slots and subslots, where each had its own virtual address space, thus eliminating device addressing conflicts in its very source. No jumpers or any manual configuration was required, and the inde... | Plug and play | Wikipedia | 510 | 158859 | https://en.wikipedia.org/wiki/Plug%20and%20play | Technology | Computer hardware | null | vital_articles |
However, the disks posed a problem if they were damaged or lost, as the only options at the time to obtain replacements were via postal mail or IBM's dial-up BBS service. Without the disks, any new hardware would be completely useless and the computer would occasionally not boot at all until the unconfigured device was... | Plug and play | Wikipedia | 451 | 158859 | https://en.wikipedia.org/wiki/Plug%20and%20play | Technology | Computer hardware | null | vital_articles |
In 1995, Microsoft released Windows 95, which tried to automate device detection and configuration as much as possible, but could still fall back to manual settings if necessary. During the initial install process of Windows 95, it would attempt to automatically detect all devices installed in the system. Since full au... | Plug and play | Wikipedia | 457 | 158859 | https://en.wikipedia.org/wiki/Plug%20and%20play | Technology | Computer hardware | null | vital_articles |
Because of this complex operating environment, the autodetection process sometimes produced incorrect results, especially in systems with large numbers of expansion devices. This led to device conflicts within Windows 95, resulting in devices which were supposed to be fully self-configuring failing to work. The unreli... | Plug and play | Wikipedia | 346 | 158859 | https://en.wikipedia.org/wiki/Plug%20and%20play | Technology | Computer hardware | null | vital_articles |
The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous acid.
Compounds
The free acid, chlorous acid HClO2, is the least stable oxoa... | Chlorite | Wikipedia | 442 | 158901 | https://en.wikipedia.org/wiki/Chlorite | Physical sciences | Halide oxyanions | Chemistry | vital_articles |
Health risks
In 2009, the California Office of Environmental Health Hazard Assessment, or OEHHA, released a public health goal of maintaining amounts lower than 50 parts per billion for chlorite in drinking water after scientists in the state reported that exposure to higher levels of chlorite affect sperm and thyroid... | Chlorite | Wikipedia | 230 | 158901 | https://en.wikipedia.org/wiki/Chlorite | Physical sciences | Halide oxyanions | Chemistry | vital_articles |
Arsenopyrite (IMA symbol: Apy) is an iron arsenic sulfide (FeAsS). It is a hard (Mohs 5.5–6) metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1.
When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it produces sulfur and arsenic v... | Arsenopyrite | Wikipedia | 484 | 158914 | https://en.wikipedia.org/wiki/Arsenopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Related minerals
Various transition group metals can substitute for iron in arsenopyrite. The arsenopyrite group includes the following rare minerals:
Clinosafflorite:
Gudmundite:
Glaucodot or alloclasite: or
Iridarsenite:
Osarsite or ruarsite: or | Arsenopyrite | Wikipedia | 66 | 158914 | https://en.wikipedia.org/wiki/Arsenopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black.
On exposure to a... | Chalcopyrite | Wikipedia | 453 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Minor amounts of elements such as silver, gold, cadmium, cobalt, nickel, lead, tin, and zinc can be measured (at parts per million levels), likely substituting for copper and iron. Selenium, bismuth, tellurium, and arsenic may substitute for sulfur in minor amounts. Chalcopyrite can be oxidized to form malachite, azur... | Chalcopyrite | Wikipedia | 449 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Even though Chalcopyrite does not contain the most copper in its structure relative to other minerals, it is the most important copper ore since it can be found in many localities. Chalcopyrite ore occurs in a variety of ore types, from huge masses as at Timmins, Ontario, to irregular veins and disseminations associate... | Chalcopyrite | Wikipedia | 447 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Chalcopyrite ore is not directly smelted. This is because the ore is primarily composed of non-economically valuable material, or waste rock, with low concentrations of copper. The abundance of waste material results in a lot of hydrocarbon fuel being required to heat and melt the ore. Alternatively, copper is isolated... | Chalcopyrite | Wikipedia | 509 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
In the copper forming stage, the matte produced from the slag stage undergoes charging (inputting the matte in the converter), blowing (blasting more oxygen), and skimming (retrieving impure molten copper known as blister copper). The reaction is as follows:
Cu2S(l) + O2(g) -> 2Cu(l) + SO2(g) + heat
Finally, the blis... | Chalcopyrite | Wikipedia | 428 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Pressure oxidation leaching is particularly useful for low grade chalcopyrite. This is because it can "process concentrate product from flotation" rather than having to process whole ore. Additionally, it can be used as an alternative method to pyrometallurgy for variable ore. Other advantages hydrometallurgical proces... | Chalcopyrite | Wikipedia | 194 | 158916 | https://en.wikipedia.org/wiki/Chalcopyrite | Physical sciences | Minerals | Earth science | vital_articles |
Labradorite ((Ca, Na)(Al, Si)4O8) is a calcium-enriched feldspar mineral first identified in Labrador, Canada, which can display an iridescent effect (schiller).
Labradorite is an intermediate to calcic member of the plagioclase series. It has an anorthite percentage (%An) of between 50 and 70. The specific gravity ra... | Labradorite | Wikipedia | 456 | 159034 | https://en.wikipedia.org/wiki/Labradorite | Physical sciences | Silicate minerals | Earth science | vital_articles |
The cause of this optical phenomenon is phase exsolution lamellar structure, occurring in the Bøggild miscibility gap. The effect is visible when the lamellar separation is between ; the lamellae are not necessarily parallel; and the lamellar structure is found to lack long range order.
The lamellar separation only oc... | Labradorite | Wikipedia | 250 | 159034 | https://en.wikipedia.org/wiki/Labradorite | Physical sciences | Silicate minerals | Earth science | vital_articles |
In mechanics and physics, shock is a sudden acceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation.
Shock describes matter subject to extreme rates of force with respect to time. Shock is a vector that has units of an acceleration (rate of change of... | Shock (mechanics) | Wikipedia | 424 | 159081 | https://en.wikipedia.org/wiki/Shock%20%28mechanics%29 | Physical sciences | Basics_4 | Physics | vital_articles |
Shock testing typically falls into two categories, classical shock testing and pyroshock or ballistic shock testing. Classical shock testing consists of the following shock impulses: half sine, haversine, sawtooth wave, and trapezoid. Pyroshock and ballistic shock tests are specialized and are not considered classica... | Shock (mechanics) | Wikipedia | 470 | 159081 | https://en.wikipedia.org/wiki/Shock%20%28mechanics%29 | Physical sciences | Basics_4 | Physics | vital_articles |
Considerations
When laboratory testing, field experience, or engineering judgement indicates that an item could be damaged by mechanical shock, several courses of action might be considered:
Reduce and control the input shock at the source.
Modify the item to improve its toughness or support it to better handle shoc... | Shock (mechanics) | Wikipedia | 104 | 159081 | https://en.wikipedia.org/wiki/Shock%20%28mechanics%29 | Physical sciences | Basics_4 | Physics | vital_articles |
A chemical composition specifies the identity, arrangement, and ratio of the chemical elements making up a compound by way of chemical and atomic bonds.
Chemical formulas can be used to describe the relative amounts of elements present in a compound. For example, the chemical formula for water is H2O: this means that ... | Chemical composition | Wikipedia | 286 | 159151 | https://en.wikipedia.org/wiki/Chemical%20composition | Physical sciences | Substance | Chemistry | vital_articles |
Conduct disorder (CD) is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior that includes theft, lies, physical violence that may lead to destruction, and reckless breaking of rules, in which the basic rights of others or major age-approp... | Conduct disorder | Wikipedia | 445 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Aggression to people and animals
Often bullies, threatens or intimidates others
Often initiates physical fights
Has used a weapon that can cause serious physical harm to others (e.g., a bat, brick, broken bottle, knife, gun)
Has been physically cruel to people
Has been physically cruel to animals
Has stolen whil... | Conduct disorder | Wikipedia | 490 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
The second developmental course is known as the "adolescent-onset type" and occurs when conduct disorder symptoms are present after the age of 10 years. Individuals with adolescent-onset conduct disorder exhibit less impairment than those with the childhood-onset type and are not characterized by similar psychopatholog... | Conduct disorder | Wikipedia | 467 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Associated conditions
Children with conduct disorder have a high risk of developing other adjustment problems. Specifically, risk factors associated with conduct disorder and the effects of conduct disorder symptomatology on a child's psychosocial context have been linked to overlapping with other psychological disorde... | Conduct disorder | Wikipedia | 478 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Risks
The development of conduct disorder is not immutable or predetermined. A number of interactive risk and protective factors exist that can influence and change outcomes, and in most cases conduct disorder develops due to an interaction and gradual accumulation of risk factors. In addition to the risk factors ident... | Conduct disorder | Wikipedia | 376 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Cognitive factors
In terms of cognitive function, intelligence and cognitive deficits are common amongst youths with conduct disorder, particularly those with early-onset and have intelligence quotients (IQ) one standard deviation below the mean and severe deficits in verbal reasoning and executive function. Executive ... | Conduct disorder | Wikipedia | 476 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Intra-individual factors
Aside from findings related to neurological and neurochemical profiles of youth with conduct disorder, intraindividual factors such as genetics may also be relevant. Having a sibling or parent with conduct disorder increases the likelihood of having the disorder, with a heritability rate of .53... | Conduct disorder | Wikipedia | 428 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Wider contextual factors
In addition to the individual and social factors associated with conduct disorder, research has highlighted the importance of environment and context in youth with antisocial behavior. However, it is important to note that these are not static factors, but rather transactional in nature (e.g., ... | Conduct disorder | Wikipedia | 488 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Prognosis
About 25–40% of youths diagnosed with conduct disorder qualify for a diagnosis of antisocial personality disorder when they reach adulthood. For those that do not develop ASPD, most still exhibit social dysfunction in adult life.
Epidemiology
Conduct disorder is estimated to affect 51.1 million people global... | Conduct disorder | Wikipedia | 341 | 159209 | https://en.wikipedia.org/wiki/Conduct%20disorder | Biology and health sciences | Mental disorders | Health | vital_articles |
Fermi–Dirac statistics is a type of quantum statistics that applies to the physics of a system consisting of many non-interacting, identical particles that obey the Pauli exclusion principle. A result is the Fermi–Dirac distribution of particles over energy states. It is named after Enrico Fermi and Paul Dirac, each of... | Fermi–Dirac statistics | Wikipedia | 495 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
Fermi–Dirac statistics was first published in 1926 by Enrico Fermi and Paul Dirac. According to Max Born, Pascual Jordan developed in 1925 the same statistics, which he called Pauli statistics, but it was not published in a timely manner. According to Dirac, it was first studied by Fermi, and Dirac called it "Fermi sta... | Fermi–Dirac statistics | Wikipedia | 450 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
From the Fermi–Dirac distribution of particles over states, one can find the distribution of particles over energy. The average number of fermions with energy can be found by multiplying the Fermi–Dirac distribution by the degeneracy (i.e. the number of states with energy ),
When , it is possible that , since th... | Fermi–Dirac statistics | Wikipedia | 480 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
For the case of conduction electrons in a typical metal at = 300 K (i.e. approximately room temperature), the system is far from the classical regime because . This is due to the small mass of the electron and the high concentration (i.e. small ) of conduction electrons in the metal. Thus Fermi–Dirac statistics is ne... | Fermi–Dirac statistics | Wikipedia | 456 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
It is also possible to derive Fermi–Dirac statistics in the canonical ensemble. Consider a many-particle system composed of N identical fermions that have negligible mutual interaction and are in thermal equilibrium. Since there is negligible interaction between the fermions, the energy of a state of the many-particl... | Fermi–Dirac statistics | Wikipedia | 489 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
A result can be achieved by directly analyzing the multiplicities of the system and using Lagrange multipliers.
Suppose we have a number of energy levels, labeled by index i, each level having energy εi and containing a total of ni particles. Suppose each level contains gi distinct sublevels, all of which have the sam... | Fermi–Dirac statistics | Wikipedia | 432 | 159225 | https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac%20statistics | Physical sciences | Statistical mechanics | Physics | vital_articles |
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and... | Gene expression | Wikipedia | 443 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In bacteria, transcription is carried out by a single type of RNA polymerase, which needs to bind a DNA sequence called a Pribnow box with the help of the sigma factor protein (σ factor) to start transcription. In eukaryotes, transcription is performed in the nucleus by three types of RNA polymerases, each of which nee... | Gene expression | Wikipedia | 449 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Another modification is 3′ cleavage and polyadenylation. They occur if polyadenylation signal sequence (5′- AAUAAA-3′) is present in pre-mRNA, which is usually between protein-coding sequence and terminator. The pre-mRNA is first cleaved and then a series of ~200 adenines (A) are added to form poly(A) tail, which prote... | Gene expression | Wikipedia | 394 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In most organisms non-coding genes (ncRNA) are transcribed as precursors that undergo further processing. In the case of ribosomal RNAs (rRNA), they are often transcribed as a pre-rRNA that contains one or more rRNAs. The pre-rRNA is cleaved and modified (2′-O-methylation and pseudouridine formation) at specific sites ... | Gene expression | Wikipedia | 474 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In eukaryotes most mature RNA must be exported to the cytoplasm from the nucleus. While some RNAs function in the nucleus, many RNAs are transported through the nuclear pores and into the cytosol. Export of RNAs requires association with specific proteins known as exportins. Specific exportin molecules are responsible ... | Gene expression | Wikipedia | 440 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In prokaryotes translation generally occurs at the point of transcription (co-transcriptionally), often using a messenger RNA that is still in the process of being created. In eukaryotes translation can occur in a variety of regions of the cell depending on where the protein being written is supposed to be. Major locat... | Gene expression | Wikipedia | 462 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Translocation
Secretory proteins of eukaryotes or prokaryotes must be translocated to enter the secretory pathway. Newly synthesized proteins are directed to the eukaryotic Sec61 or prokaryotic SecYEG translocation channel by signal peptides. The efficiency of protein secretion in eukaryotes is very dependent on the si... | Gene expression | Wikipedia | 356 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Numerous terms are used to describe types of genes depending on how they are regulated; these include:
A constitutive gene is a gene that is transcribed continually as opposed to a facultative gene, which is only transcribed when needed.
A housekeeping gene is a gene that is required to maintain basic cellular functi... | Gene expression | Wikipedia | 475 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
The activity of transcription factors is further modulated by intracellular signals causing protein post-translational modification including phosphorylation, acetylation, or glycosylation. These changes influence a transcription factor's ability to bind, directly or indirectly, to promoter DNA, to recruit RNA polymera... | Gene expression | Wikipedia | 465 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
The illustration shows an enhancer looping around to come into proximity with the promoter of a target gene. The loop is stabilized by a dimer of a connector protein (e.g. dimer of CTCF or YY1). One member of the dimer is anchored to its binding motif on the enhancer and the other member is anchored to its binding moti... | Gene expression | Wikipedia | 457 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Methylation of cytosine in DNA has a major role in regulating gene expression. Methylation of CpGs in a promoter region of a gene usually represses gene transcription while methylation of CpGs in the body of a gene increases expression. TET enzymes play a central role in demethylation of methylated cytosines. Demethyla... | Gene expression | Wikipedia | 278 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Some specific mechanisms guiding new DNA methylations and new DNA demethylations in the hippocampus during memory establishment have been established (see for summary). One mechanism includes guiding the short isoform of the TET1 DNA demethylation enzyme, TET1s, to about 600 locations on the genome. The guidance is p... | Gene expression | Wikipedia | 498 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In eukaryotes, where export of RNA is required before translation is possible, nuclear export is thought to provide additional control over gene expression. All transport in and out of the nucleus is via the nuclear pore and transport is controlled by a wide range of importin and exportin proteins.
Expression of a gen... | Gene expression | Wikipedia | 418 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
As of 2014, the miRBase web site, an archive of miRNA sequences and annotations, listed 28,645 entries in 233 biologic species. Of these, 1,881 miRNAs were in annotated human miRNA loci. miRNAs were predicted to have an average of about four hundred target mRNAs (affecting expression of several hundred genes). Friedman... | Gene expression | Wikipedia | 438 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
PTMs play many important roles in the cell. For example, phosphorylation is primarily involved in activating and deactivating proteins and in signaling pathways. PTMs are involved in transcriptional regulation: an important function of acetylation and methylation is histone tail modification, which alters how accessibl... | Gene expression | Wikipedia | 419 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
mRNA quantification
Levels of mRNA can be quantitatively measured by northern blotting, which provides size and sequence information about the mRNA molecules. A sample of RNA is separated on an agarose gel and hybridized to a radioactively labeled RNA probe that is complementary to the target sequence. The radiolabeled... | Gene expression | Wikipedia | 365 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
For expression profiling, or high-throughput analysis of many genes within a sample, quantitative PCR may be performed for hundreds of genes simultaneously in the case of low-density arrays. A second approach is the hybridization microarray. A single array or "chip" may contain probes to determine transcript levels for... | Gene expression | Wikipedia | 391 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
One of the most commonly used methods is to perform a Western blot against the protein of interest. This gives information on the size of the protein in addition to its identity. A sample (often cellular lysate) is separated on a polyacrylamide gel, transferred to a membrane and then probed with an antibody to the prot... | Gene expression | Wikipedia | 448 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
The enzyme-linked immunosorbent assay works by using antibodies immobilised on a microtiter plate to capture proteins of interest from samples added to the well. Using a detection antibody conjugated to an enzyme or fluorophore the quantity of bound protein can be accurately measured by fluorometric or colourimetric de... | Gene expression | Wikipedia | 475 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Gene networks can also be constructed without formulating an explicit causal model. This is often the case when assembling networks from large expression data sets. Covariation and correlation of expression is computed across a large sample of cases and measurements (often transcriptome or proteome data). The source of... | Gene expression | Wikipedia | 336 | 159266 | https://en.wikipedia.org/wiki/Gene%20expression | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Potassium chloride (KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a salt-like taste. Potassium chloride can be obtained from ancient dried lake depos... | Potassium chloride | Wikipedia | 422 | 159292 | https://en.wikipedia.org/wiki/Potassium%20chloride | Physical sciences | Halide salts | Chemistry | vital_articles |
Potassium is vital in the human body, and potassium chloride by mouth is the standard means to treat low blood potassium, although it can also be given intravenously. It is on the World Health Organization's List of Essential Medicines. It is also an ingredient in Oral Rehydration Therapy (ORT)/solution (ORS) to reduce... | Potassium chloride | Wikipedia | 507 | 159292 | https://en.wikipedia.org/wiki/Potassium%20chloride | Physical sciences | Halide salts | Chemistry | vital_articles |
Potassium chloride is used in some de-icing products designed to be safer for pets and plants, though these are inferior in melting quality to calcium chloride. It is also used in various brands of bottled water.
Potassium chloride was once used as a fire extinguishing agent, and in portable and wheeled fire extinguis... | Potassium chloride | Wikipedia | 511 | 159292 | https://en.wikipedia.org/wiki/Potassium%20chloride | Physical sciences | Halide salts | Chemistry | vital_articles |
Redox and the conversion to potassium metal
Although potassium is more electropositive than sodium, KCl can be reduced to the metal by reaction with metallic sodium at 850 °C because the more volatile potassium can be removed by distillation (see Le Chatelier's principle):
KCl_{(l)}{} + Na_{(l)} <=> NaCl_{(l)}{} + K_{(... | Potassium chloride | Wikipedia | 474 | 159292 | https://en.wikipedia.org/wiki/Potassium%20chloride | Physical sciences | Halide salts | Chemistry | vital_articles |
Potassium chloride is extracted from minerals sylvite, carnallite, and potash. It is also extracted from salt water and can be manufactured by crystallization from solution, flotation or electrostatic separation from suitable minerals. It is a by-product of the production of nitric acid from potassium nitrate and hydro... | Potassium chloride | Wikipedia | 224 | 159292 | https://en.wikipedia.org/wiki/Potassium%20chloride | Physical sciences | Halide salts | Chemistry | vital_articles |
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailerons, elevator and rudder, calling the former "microlight" and the latter "ul... | Ultralight aviation | Wikipedia | 449 | 159298 | https://en.wikipedia.org/wiki/Ultralight%20aviation | Technology | Types of aircraft | null | vital_articles |
Other than the very earliest aircraft, all two-seat UK microlights (and until 2007 all single-seaters) have been required to meet an airworthiness standard; BCAR Section S.
In 2007, Single Seat DeRegulated (SSDR), a sub-category of single seat aircraft was introduced, allowing owners more freedom for modification and e... | Ultralight aviation | Wikipedia | 254 | 159298 | https://en.wikipedia.org/wiki/Ultralight%20aviation | Technology | Types of aircraft | null | vital_articles |
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