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of P. vivax transmission, there is evidence for the transmission of P. vivax among Duffy-negative populations in Western Kenya, the Brazilian Amazon region, and Madagascar. The Malagasy people on Madagascar have an admixture of Duffy-positive and Duffy-negative people of diverse ethnic backgrounds. 72% of the island po...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
to P. vivax transmission. ==== Gerbich antigen receptor negativity ==== The Gerbich antigen system is an integral membrane protein of the erythrocyte and plays a functionally important role in maintaining erythrocyte shape. It also acts as the receptor for the P. falciparum erythrocyte binding protein. There are four a...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
with Hereditary persistence of fetal hemoglobin. == Validating the malaria hypothesis == Evolutionary biologist J.B.S. Haldane was the first to give a hypothesis on the relationship between malaria and the genetic disease. He first delivered his hypothesis at the Eighth International Congress of Genetics held in 1948 a...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
to falciparum malaria; there could be many such genes exerting more modest effects that are challenging to detect by GWA because of the low levels of linkage disequilibrium in African populations. However, the same GWA association in two populations is powerful evidence that the single gene conferring strongest innate ...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
frequency is about 20%, and a fitness superiority over those with normal hemoglobin of the order of 10% is sufficient to produce a stable polymorphism. == Glossary == actin, ankrin, spectrin – proteins that are the major components of the cytoskeleton scaffolding within a cell's cytoplasm aerobic – uses oxygen for the ...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
of small cytokines, or signaling proteins secreted by cells codon – a sequence of three nucleotides which specify which amino acid will be added next during protein synthesis corpuscle – obsolete name for red blood cell cytoadherance – infected red blood cells may adhere to blood vellel walls and uninfected red blood c...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
HbE, HbS, etc.) hemoglobin (hemoglobin polymorphisms: hemoglobin type C, hemoglobin type E, hemoglobin type S) hematopoietic (stem cell) – the blood stem cells that give rise to all other blood cells heme oxygenase-1 (HO-1) – an enzyme that breaks down heme, the iron-containing non-protein part of hemoglobin hemoglobin...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
called the human leucocyte antigen (HLA) system micro-RNA – a cellular RNA fragment that prevents the production of a particular protein by binding to and destroying the messenger RNA that would have produced the protein. microvasculature – very small blood vessels mitochondria – energy producing organelles of a cell m...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
membrane proteins that take part in communication between the cell and the outside world; receptors are responsive to specific ligands that attach to them. reducing environment (cellular) – reducing environment is one where oxidation is prevented by removal of oxygen and other oxidising gases or vapours, and which may ...	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
Nova Science Publishers Inc, New York. ISBN 9781606929438 == External links == Favism Hemoglobinopathies Malaria and the Red Cell	{ "page_id": 24973826, "title": "Human genetic resistance to malaria" }
Aptamers are oligomers of artificial ssDNA, RNA, XNA, or peptide that bind a specific target molecule, or family of target molecules. They exhibit a range of affinities (KD in the pM to μM range), with variable levels of off-target binding and are sometimes classified as chemical antibodies. Aptamers and antibodies can...	{ "page_id": 1970691, "title": "Aptamer" }
resist digestion by DNA- and RNA-destroying enzymes. Therapeutic aptamers often must be modified to clear slowly from the body. Aptamers that change their shape dramatically when they bind their target are useful as molecular switches to turn a sensor on and off. Some aptamers are engineered to fit into a biosensor or ...	{ "page_id": 1970691, "title": "Aptamer" }
system and the generation of ribozymes with modified cleavage activity. In 1990, two teams independently developed and published SELEX (Systematic Evolution of Ligands by EXponential enrichment) methods and generated RNA aptamers: the lab of Larry Gold, using the term SELEX for their process of selecting RNA ligands ag...	{ "page_id": 1970691, "title": "Aptamer" }
or in vivo. As 22 genetically-encoded and over 500 naturally-occurring amino acids exist, peptide aptamers, as well as antibodies, have much greater potential combinatorial diversity per unit length relative to the 4 nucleic acids in DNA or RNA. Chemical modifications of nucleic acid bases or backbones increase the che...	{ "page_id": 1970691, "title": "Aptamer" }
their ability to bind the target protein EBOV sGP. Although these aptamers vary in both sequence and structure, they exhibit remarkably similar relative affinities for sGP from EBOV and SUDV, as well as EBOV GP1.2. Notably, these aptamers demonstrated a high degree of specificity for the GP gene products. One aptamer, ...	{ "page_id": 1970691, "title": "Aptamer" }
than nucleic acids. They are also costly to maintain and produce, and are at constant risk of contamination, as they are produced via cell culture or are harvested from animal serum. For this reason, researchers interested in little-studied proteins and species may find that companies will not produce, maintain, or ade...	{ "page_id": 1970691, "title": "Aptamer" }
target, and lower affinities may aid in the release of the target molecule. Hence, specific applications determine the useful range for aptamer affinity. === Antibody replacement === Aptamers can replace antibodies in many biotechnology applications. In laboratory research and clinical diagnostics, they can be used in ...	{ "page_id": 1970691, "title": "Aptamer" }
binding strength to passively release the growth factors, along with active release via mechanisms such as hybridization of the aptamer with complementary oligonucleotides or unfolding of the aptamer due to cellular traction forces. === Tissue Engineering Application === Aptamer, known for their ability to bind specifi...	{ "page_id": 1970691, "title": "Aptamer" }
common peptide aptamer selection system is the yeast two-hybrid system. Peptide aptamers can also be selected from combinatorial peptide libraries constructed by phage display and other surface display technologies such as mRNA display, ribosome display, bacterial display and yeast display. These experimental procedure...	{ "page_id": 1970691, "title": "Aptamer" }
The molecular formula C22H28O4 may refer to: Gestadienol acetate, an orally active progestin Vamorolone, a synthetic steroid Estradiol diacetate, an estrogen ester	{ "page_id": 55251458, "title": "C22H28O4" }
In genetics and cell biology, repression is a mechanism often used to decrease or inhibit the expression of a gene. Removal of repression is called derepression. This mechanism may occur at different stages in the expression of a gene, all resulting with increasing the overall RNA or protein products. Dysregulation of ...	{ "page_id": 8786437, "title": "Derepression" }
Translation == Derepression of translation increases protein production without altering the levels of mRNA in the cell. miRNAs are a common mechanism of translation repression, binding to the mRNA through complementary base pairing to silence them. Certain RNA binding proteins have been shown to target untranslated re...	{ "page_id": 8786437, "title": "Derepression" }
susceptibility to tumors and growth abnormalities in children. A common cause of this syndrome is a mutation in an imprint control region near the Igf2 gene. This imprint control region is normally bound by an insulator on the maternal allele, which represses an enhancer from acting on the Igf2 gene. This insulator is ...	{ "page_id": 8786437, "title": "Derepression" }
Before the fertilized ovum reaches the uterus, the mucous membrane of the body of the uterus undergoes important changes and is then known as the decidua. The thickness and vascularity of the mucous membrane are greatly increased; its glands are elongated and open on its free surface by funnel-shaped orifices, while th...	{ "page_id": 8196616, "title": "Decidual cells" }
Liver cytology is the branch of cytology that studies the liver cells and its functions. The liver is a vital organ, in charge of almost all the body’s metabolism. Main liver cells are hepatocytes, Kupffer cells, and hepatic stellate cells; each one with a specific function. == Definitions == Cytology is the name given...	{ "page_id": 39326219, "title": "Liver cytology" }
removed during the procedure for later analysis. Finally, another common method is biopsy. In a biopsy, a needle is inserted into the skin and a solid sample of tissue is obtained. After the sample is obtained, it has to be processed by different methods depending on the nature of the sample. Liquid samples, such as bl...	{ "page_id": 39326219, "title": "Liver cytology" }
and they are probably capable of modifying the canaliculi’s diameter, thus influencing the flow; however this is not yet proven. The intercellular surfaces are the ones that are between two adjacent hepatocytes and they are not in contact with sinusoids or canaliculi. These are simple surfaces specialized in the cellul...	{ "page_id": 39326219, "title": "Liver cytology" }
synthesis of cholesterol and lipoproteins. == Kupffer cells == Liver sinusoids are different from the rest of the body’s sinusoids since they have macrophage cells intercalated in between their endothelial cells. Kupffer cells have a different embryological origin, coming from the myeloid line in the reticuloendohelial...	{ "page_id": 39326219, "title": "Liver cytology" }
A nuclear emulsion plate is a type of particle detector first used in nuclear and particle physics experiments in the early decades of the 20th century. It is a modified form of photographic plate that can be used to record and investigate fast charged particles like alpha-particles, nucleons, leptons or mesons. After ...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
the subnuclear "particle zoo", defining a milestone in the development of modern experimental particle physics. The chief disadvantage of nuclear emulsion is that it is a dense and complex material (silver, bromine, carbon, nitrogen, oxygen) which potentially impedes the flight of particles to other detector components...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
by the interaction of the many charged alpha particles, making up the rays, with silver halide grains in the photographic emulsion that were made visible by photographic development. Rutherford encouraged his research colleague at Manchester, Kinoshita Suekiti, to investigate in more detail the photographic action of t...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
newly discovered by Victor Hess in 1912. However, progress was halted by the onset of World War I in 1914. The outstanding issue of improving the particle detection performance of standard photographic emulsions, in order to detect other types of particle - protons, for example, produce about one quarter of the ionisat...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
Ilford Photo) to thicken the emulsion on its commercial plates, and she experimented with other emulsion parameters — grain size, latent image retention, development conditions — to improve the visibility of alpha-particle and fast-proton tracks. In 1937, Marietta Blau and her former student Hertha Wambacher discovered...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
series of high altitude mountain-top experiments using photographic emulsion to detect and analyse cosmic rays. These measurements were notable for the first ever detection of muons by the photographic method: Chowdhuri's painstaking analysis of the observed tracks’ properties, including exposed halide grain densities ...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
In 1949, analysing plates exposed at the Sphinx Observatory on the Jungfraujoch in Switzerland, first precise observations of the positive K-meson and its ‘strange’ decays were made by Rosemary Brown (now Rosemary Fowler), a research student in Cecil Powell's group at Bristol. Then known as the ‘Tau meson’ in the Tau-t...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
or to integrate their effect, has found application. These applications in most cases involve the tracing of implanted radioactive markers by Autoradiography. Examples are: Medical research Biological research Metallurgy Reactive surface chemistry Radiation protection Muon tomography (Muography) Archaeology. == Referen...	{ "page_id": 9769489, "title": "Nuclear emulsion" }
A tertiary carbon atom is a carbon atom bound to three other carbon atoms. For this reason, tertiary carbon atoms are found only in hydrocarbons containing at least four carbon atoms. They are called saturated hydrocarbons because they only contain carbon-carbon single bonds. Tertiary carbons have a hybridization of sp...	{ "page_id": 16912915, "title": "Tertiary carbon" }
carbons are similarly preferred in E1 for the same reasons as it has a carbocation intermediate. E1 and E2 reactions follow Zaitsev's rule which states that the most substituted product in an elimination reactions is going to be the major product because it will be favored for its stability. This leads to tertiary carb...	{ "page_id": 16912915, "title": "Tertiary carbon" }
In physical chemistry, there are numerous quantities associated with chemical compounds and reactions; notably in terms of amounts of substance, activity or concentration of a substance, and the rate of reaction. This article uses SI units. == Introduction == Theoretical chemistry requires quantities from core physics,...	{ "page_id": 33034771, "title": "Defining equation (physical chemistry)" }
be written with subscripts χF-F, χFF or χF-F etc., or brackets χ(F-F), χ(FF) etc. Neither is standard. For the purpose of this article, the nomenclature is as follows, closely (but not exactly) matching standard use. For general equations with no specific reference to an entity, quantities are written as their symbols ...	{ "page_id": 33034771, "title": "Defining equation (physical chemistry)" }
reactant mixture, Yj = reactant component j of the product mixture, r (as an index) = number of reactant components, p (as an index) = number of product components, νi = stoichiometry number for component i in product mixture, ηj = stoichiometry number for component j in product mixture, σi = order of reaction for comp...	{ "page_id": 33034771, "title": "Defining equation (physical chemistry)" }
( B + \| B ) {\displaystyle E^{\ominus }\left({\ce {B+}}\vert {\ce {B}}\right)} respectively. For the case of a metal-metal half electrode, letting M represent the metal and z be its valency, the half reaction takes the form of a reduction reaction: M + z + z e − ↽ − − ⇀ M {\displaystyle {\ce {{M^{+{\mathit {z}}}}+{\mat...	{ "page_id": 33034771, "title": "Defining equation (physical chemistry)" }
Johan Peter Holtsmark (13 February 1894 – 10 December 1975) was a Norwegian physicist, who studied spectral line broadening and electron scattering. In 1929, while at the Norwegian Institute of Technology, Holtsmark established acoustics research laboratories, focusing on architectural acoustics and sound insulation. H...	{ "page_id": 20976147, "title": "Johan Peter Holtsmark" }
Since the first printing of Carl Linnaeus's Species Plantarum in 1753, plants have been assigned one epithet or name for their species and one name for their genus, a grouping of related species. Thousands of plants have been named for people, including botanists and their colleagues, plant collectors, horticulturists,...	{ "page_id": 66261527, "title": "List of plant genera named for people (D–J)" }
Dictionary of Plant Names for Gardeners In addition, Burkhardt's Index is used as a reference for every row in the table, except as noted. == Genera == == See also == List of plant genus names with etymologies: A–C, D–K, L–P, Q–Z List of plant family names with etymologies == Notes == == Citations == == References == B...	{ "page_id": 66261527, "title": "List of plant genera named for people (D–J)" }
reading == Gledhill, David (2008). The Names of Plants. New York, New York: Cambridge University Press. ISBN 978-0-521-86645-3.	{ "page_id": 66261527, "title": "List of plant genera named for people (D–J)" }
The Twister supersonic separator is a compact tubular device which is used for removing water and/or hydrocarbon dewpointing of natural gas. The principle of operation is similar to the near isentropic Brayton cycle of a turboexpander. The gas is accelerated to supersonic velocities within the tube using a De Laval noz...	{ "page_id": 7737880, "title": "Twister supersonic separator" }
Recycling antimatter pertains to recycling antiprotons and antihydrogen atoms. == References == == Further reading == Surko, C. M.; Greaves, R. G. (2004). "Emerging science and technology of antimatter plasmas and trap-based beams" (PDF). Physics of Plasmas. 11 (5): 2333. Bibcode:2004PhPl...11.2333S. doi:10.1063/1.1651...	{ "page_id": 42406424, "title": "Recycling antimatter" }
The isoenthalpic-isobaric ensemble (constant enthalpy and constant pressure ensemble) is a statistical mechanical ensemble that maintains constant enthalpy H {\displaystyle H\,} and constant pressure P {\displaystyle P\,} applied. It is also called the N P H {\displaystyle NPH} -ensemble, where the number of particles ...	{ "page_id": 14422554, "title": "Isoenthalpic–isobaric ensemble" }
Localized molecular orbitals are molecular orbitals which are concentrated in a limited spatial region of a molecule, such as a specific bond or lone pair on a specific atom. They can be used to relate molecular orbital calculations to simple bonding theories, and also to speed up post-Hartree–Fock electronic structure...	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
move over both bonds. However, in quantum mechanics all electrons are identical and cannot be distinguished as same or other. The total wavefunction must have a form which satisfies the Pauli exclusion principle such as a Slater determinant (or linear combination of Slater determinants), and it can be shown that if two...	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
=== The Foster-Boys (also known as Boys) localization method minimizes the spatial extent of the orbitals by minimizing ⟨ L ^ ⟩ {\displaystyle \langle {\hat {L}}\rangle } , where L ^ = \| r → 1 − r → 2 \| 2 {\displaystyle {\hat {L}}=\|{\vec {r}}_{1}-{\vec {r}}_{2}\|^{2}} . This turns out to be equivalent to the easier task...	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
→ 2 \| − 1 {\displaystyle {\hat {L}}=\|{\vec {r}}_{1}-{\vec {r}}_{2}\|^{-1}} . === Pipek-Mezey === Pipek-Mezey localization takes a slightly different approach, maximizing the sum of orbital-dependent partial charges on the nuclei: ⟨ L ^ ⟩ PM = ∑ A atoms ∑ i orbitals \| q i A \| 2 {\displaystyle \langle {\hat {L}}\rangle _{...	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
hybridization models of bonding. To account for phenomena like aromaticity, this simple model of bonding is supplemented by semi-quantitative results from Hückel molecular orbital theory. However, the understanding of stereoelectronic effects requires the analysis of interactions between donor and acceptor orbitals bet...	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
see the article on lone pair and the discussion above on sigma-pi and equivalent-orbital models). In other words, the type of localized orbital invoked depends on context and considerations of convenience and utility. == References ==	{ "page_id": 9769502, "title": "Localized molecular orbitals" }
Prey naïveté hypothesis is a theory that suggests that native prey often struggle to recognize or avoid an introduced predator because they lack a coevolutionary history with it. Prey naïveté is believed to intensify the effects of non-native predators, which can contribute significantly to the risks of extinction and ...	{ "page_id": 77992485, "title": "Prey naiveté" }
hypothesized to arise from several interrelated factors, categorized into four themes: Biogeographic isolation: Prey naiveté is thought to be exacerbated by evolutionary isolation between predator and prey, particularly in freshwater environments. Island ecosystems may also experience heightened naiveté due to lack of ...	{ "page_id": 77992485, "title": "Prey naiveté" }
two prey species—the burrowing bettong (Bettongia lesueur) and spinifex hopping mouse (Notomys alexis)—to the reintroduction of a native predator, the western quoll (Dasyurus geoffroii), and its impact on their responses to feral cats (Felis catus). Results indicated that quoll-exposed bettongs engaged in less inattent...	{ "page_id": 77992485, "title": "Prey naiveté" }
Iron(II) gluconate, or ferrous gluconate, is a black compound often used as an iron supplement. It is the iron(II) salt of gluconic acid. It is marketed under brand names such as Fergon, Ferralet and Simron. == Uses == === Medical === Ferrous gluconate is effectively used in the treatment of hypochromic anemia. The use...	{ "page_id": 4198953, "title": "Iron(II) gluconate" }
The molecular formula C15H24O may refer to: Butylated hydroxytoluene, a food additive Khusimol Nonylphenol 1-Nonyl-4-phenol α-Santalol β-Santalol Spathulenol	{ "page_id": 7475753, "title": "C15H24O" }
Effervescence is the escape of gas from an aqueous solution and the foaming or fizzing that results from that release. The word effervescence is derived from the Latin verb fervere (to boil), preceded by the adverb ex. It has the same linguistic root as the word fermentation. Effervescence can also be observed when ope...	{ "page_id": 856618, "title": "Effervescence" }
Bromochlorofluoroiodomethane is a hypothetical haloalkane with all four stable halogen substituents present in it. == Overview == This compound can be seen as a methane molecule, whose four hydrogen atoms are each replaced with a different halogen atom. As the mirror images of this molecule are not superimposable, the ...	{ "page_id": 23990825, "title": "Bromochlorofluoroiodomethane" }
Methoxy arachidonyl fluorophosphonate, commonly referred as MAFP, is an irreversible active site-directed enzyme inhibitor that inhibits nearly all serine hydrolases and serine proteases. It inhibits phospholipase A2 and fatty acid amide hydrolase with special potency, displaying IC50 values in the low-nanomolar range....	{ "page_id": 12063277, "title": "Methoxy arachidonyl fluorophosphonate" }
Australasian Agribusiness Review (ISSN 1442-6951) is a peer-reviewed academic journal in the field of agribusiness. One of the initial co-editors was Bill Schroder. == References == == External links == Official website ISSN 1320-0348	{ "page_id": 25170477, "title": "Australasian Agribusiness Review" }
A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. The boundary of no escape is called the event horizon. A black hole has a great e...	{ "page_id": 4650, "title": "Black hole" }
has formed, it can grow by absorbing mass from its surroundings. Supermassive black holes of millions of solar masses may form by absorbing other stars and merging with other black holes, or via direct collapse of gas clouds. There is consensus that supermassive black holes exist in the centres of most galaxies. The pr...	{ "page_id": 4650, "title": "Black hole" }
speed of light. Michell correctly noted that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies. In 1796, Laplace mentioned that a star could be invisible if it were sufficiently large while speculating on the origin of the Solar System in his boo...	{ "page_id": 4650, "title": "Black hole" }
a star with mass compressed to the Schwarzschild radius in a 1926 book, noting that Einstein's theory allows us to rule out overly large densities for visible stars like Betelgeuse because "a star of 250 million km radius could not possibly have so high a density as the Sun. Firstly, the force of gravitation would be s...	{ "page_id": 4650, "title": "Black hole" }
generated a black hole shortly afterward, have refined the TOV limit estimate to ~2.17 M☉. Oppenheimer and his co-authors interpreted the singularity at the boundary of the Schwarzschild radius as indicating that this was the boundary of a bubble in which time stopped. This is a valid point of view for external observe...	{ "page_id": 4650, "title": "Black hole" }
research. This process was helped by the discovery of pulsars by Jocelyn Bell Burnell in 1967, which, by 1969, were shown to be rapidly rotating neutron stars. Until that time, neutron stars, like black holes, were regarded as just theoretical curiosities; but the discovery of pulsars showed their physical relevance an...	{ "page_id": 4650, "title": "Black hole" }
the behaviour of a black hole in close analogy to the laws of thermodynamics by relating mass to energy, area to entropy, and surface gravity to temperature. The analogy was completed when Hawking, in 1974, showed that quantum field theory implies that black holes should radiate like a black body with a temperature pro...	{ "page_id": 4650, "title": "Black hole" }
of the American Association for the Advancement of Science held in Cleveland, Ohio. In December 1967, a student reportedly suggested the phrase "black hole" at a lecture by John Wheeler; Wheeler adopted the term for its brevity and "advertising value", and it quickly caught on, leading some to credit Wheeler with coini...	{ "page_id": 4650, "title": "Black hole" }
(through the ADM mass), far away from the black hole. Likewise, the angular momentum (or spin) can be measured from far away using frame dragging by the gravitomagnetic field, through for example the Lense–Thirring effect. When an object falls into a black hole, any information about the shape of the object or distribu...	{ "page_id": 4650, "title": "Black hole" }
same mass. The popular notion of a black hole "sucking in everything" in its surroundings is therefore correct only near a black hole's horizon; far away, the external gravitational field is identical to that of any other body of the same mass. Solutions describing more general black holes also exist. Non-rotating char...	{ "page_id": 4650, "title": "Black hole" }
value. That uncharged limit is J ≤ G M 2 c , {\displaystyle J\leq {\frac {GM^{2}}{c}},} allowing definition of a dimensionless spin parameter such that 0 ≤ c J G M 2 ≤ 1. {\displaystyle 0\leq {\frac {cJ}{GM^{2}}}\leq 1.} Black holes are commonly classified according to their mass, independent of angular momentum, J. Th...	{ "page_id": 4650, "title": "Black hole" }
clocks near a black hole which would appear to tick more slowly than those farther away from the black hole. This effect, known as gravitational time dilation, would also cause an object falling into a black hole to appear to slow as it approaches the event horizon, taking an infinite amount of time to reach it. All pr...	{ "page_id": 4650, "title": "Black hole" }
has zero volume. It can also be shown that the singular region contains all the mass of the black hole solution. The singular region can thus be thought of as having infinite density. Even though the Schwarzschild model is not valid at the singularity, observers falling into a Schwarzschild black hole (i.e., non-rotati...	{ "page_id": 4650, "title": "Black hole" }
a single theory, although there exist attempts to formulate such a theory of quantum gravity. It is generally expected that such a theory will not feature singularities. === Photon sphere === The photon sphere is a spherical boundary where photons that move on tangents to that sphere would be trapped in a non-stable bu...	{ "page_id": 4650, "title": "Black hole" }
so strong near the event horizon that an object would have to move faster than the speed of light in the opposite direction to just stand still. The ergosphere of a black hole is a volume bounded by the black hole's event horizon and the ergosurface, which coincides with the event horizon at the poles but is at a much ...	{ "page_id": 4650, "title": "Black hole" }
hole is called the plunging region. In this area it is no longer possible for matter to follow circular orbits or to stop a final descent into the black hole. Instead it will rapidly plunge toward the black hole close to the speed of light. == Formation and evolution == Given the bizarre character of black holes, it wa...	{ "page_id": 4650, "title": "Black hole" }
through stellar nucleosynthesis, or because a star that would have been stable receives extra matter in a way that does not raise its core temperature. In either case the star's temperature is no longer high enough to prevent it from collapsing under its own weight. The collapse may be stopped by the degeneracy pressur...	{ "page_id": 4650, "title": "Black hole" }
from the direct collapse of gas clouds in the young universe. These massive objects have been proposed as the seeds that eventually formed the earliest quasars observed already at redshift z ∼ 7 {\displaystyle z\sim 7} . Some candidates for such objects have been found in observations of the young universe. While most ...	{ "page_id": 4650, "title": "Black hole" }
in size from a Planck mass ( m P = ℏ c / G {\displaystyle m_{P}={\sqrt {\hbar c/G}}} ≈ 1.2×1019 GeV/c2 ≈ 2.2×10−8 kg) to hundreds of thousands of solar masses. Despite the early universe being extremely dense, it did not re-collapse into a black hole during the Big Bang, since the expansion rate was greater than the at...	{ "page_id": 4650, "title": "Black hole" }
theories are very speculative, and the creation of black holes in these processes is deemed unlikely by many specialists. Even if micro black holes could be formed, it is expected that they would evaporate in about 10−25 seconds, posing no threat to the Earth. === Growth === Once a black hole has formed, it can continu...	{ "page_id": 4650, "title": "Black hole" }
black hole, which, for a Schwarzschild black hole, is inversely proportional to the mass. Hence, large black holes emit less radiation than small black holes. A stellar black hole of 1 M☉ has a Hawking temperature of 62 nanokelvins. This is far less than the 2.7 K temperature of the cosmic microwave background radiatio...	{ "page_id": 4650, "title": "Black hole" }
limits on the possibility of existence of low mass primordial black holes. NASA's Fermi Gamma-ray Space Telescope launched in 2008 will continue the search for these flashes. If black holes evaporate via Hawking radiation, a solar mass black hole will evaporate (beginning once the temperature of the cosmic microwave ba...	{ "page_id": 4650, "title": "Black hole" }
of the event horizon, displayed as orange or red, that define the black hole. On 12 May 2022, the EHT released the first image of Sagittarius A, the supermassive black hole at the centre of the Milky Way galaxy. The published image displayed the same ring-like structure and "shadow" seen in the M87 black hole. The bo...	{ "page_id": 4650, "title": "Black hole" }
far side of the accretion disc bent around the black hole's gravity well and escaped, meaning that most of the possible perspectives on M87* can see the entire disc, even that directly behind the "shadow". In 2015, the EHT detected magnetic fields just outside the event horizon of Sagittarius A* and even discerned some...	{ "page_id": 4650, "title": "Black hole" }
ringdown. From these, it is possible to infer the mass and angular momentum of the final object, which match independent predictions from numerical simulations of the merger. The frequency and decay time of the dominant mode are determined by the geometry of the photon sphere. Hence, observation of this mode confirms t...	{ "page_id": 4650, "title": "Black hole" }
confining so much invisible mass into such a small volume. Additionally, there is some observational evidence that this object might possess an event horizon, a feature unique to black holes. === Accretion of matter === Due to conservation of angular momentum, gas falling into the gravitational well created by a massiv...	{ "page_id": 4650, "title": "Black hole" }
have been attributed to the accretion of matter on black holes. In particular, active galactic nuclei and quasars are believed to be the accretion disks of supermassive black holes. Similarly, X-ray binaries are generally accepted to be binary star systems in which one of the two stars is a compact object accreting mat...	{ "page_id": 4650, "title": "Black hole" }
(the maximum mass a star can have without collapsing) then the object cannot be a neutron star and is generally expected to be a black hole. The first strong candidate for a black hole, Cygnus X-1, was discovered in this way by Charles Thomas Bolton, Louise Webster, and Paul Murdin in 1972. Some doubt remained, due to ...	{ "page_id": 4650, "title": "Black hole" }
these AGN consist of a central black hole that may be millions or billions of times more massive than the Sun; a disk of interstellar gas and dust called an accretion disk; and two jets perpendicular to the accretion disk. Although supermassive black holes are expected to be found in most AGN, only some galaxies' nucle...	{ "page_id": 4650, "title": "Black hole" }
hole. Another possibility for observing gravitational lensing by a black hole would be to observe stars orbiting the black hole. There are several candidates for such an observation in orbit around Sagittarius A*. == Alternatives == The evidence for stellar black holes strongly relies on the existence of an upper limit...	{ "page_id": 4650, "title": "Black hole" }
must fail as a theory of gravity, perhaps due to the onset of quantum mechanical corrections. A much anticipated feature of a theory of quantum gravity is that it will not feature singularities or event horizons and thus black holes would not be real artefacts. For example, in the fuzzball model based on string theory,...	{ "page_id": 4650, "title": "Black hole" }
radiates blackbody radiation at a constant temperature. This seemingly causes a violation of the second law of black hole mechanics, since the radiation will carry away energy from the black hole causing it to shrink. The radiation also carries away entropy, and it can be proven under general assumptions that the sum o...	{ "page_id": 4650, "title": "Black hole" }
black holes both in string theory and in other approaches to quantum gravity like loop quantum gravity. === Information loss paradox === Because a black hole has only a few internal parameters, most of the information about the matter that went into forming the black hole is lost. Regardless of the type of matter which...	{ "page_id": 4650, "title": "Black hole" }
is emitted as a quantum of Hawking radiation; the infalling particle is swallowed by the black hole. Assume a black hole formed a finite time in the past and will fully evaporate away in some finite time in the future. Then, it will emit only a finite amount of information encoded within its Hawking radiation. Accordin...	{ "page_id": 4650, "title": "Black hole" }
S. W.; Ellis, G. F. R. (1973). Large Scale Structure of space time. Cambridge University Press. ISBN 978-0-521-09906-6. Archived from the original on 21 July 2020. Retrieved 16 May 2020. Misner, Charles; Thorne, Kip S.; Wheeler, John (1973). Gravitation. W. H. Freeman and Company. ISBN 978-0-7167-0344-0. Thorne, Kip S....	{ "page_id": 4650, "title": "Black hole" }
Plectenchyma (from Greek πλέκω pleko 'I weave' and ἔγχυμα enchyma 'infusion', i.e., 'a woven tissue') is the general term employed to designate all types of fungal tissues. The two most common types of tissues are prosenchyma and pseudoparenchyma. The hyphae specifically become fused together. == Notes ==	{ "page_id": 38212144, "title": "Plectenchyma" }

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