Split (1)

train · 115k rows

text stringlengths 2 4.67k	source dict
strong oxidizer and its heat of reaction with reducing agents or combustibles may accelerate burning. Explosion: No danger of explosion. KNO3 is an oxidising agent, so will accelerate combustion of combustibles. Fire Extinguishing Media: Dry chemical, carbon dioxide, Halon, water spray, or fog. If water is used, apply ...	{ "page_id": 7282047, "title": "Potassium nitrate (data page)" }
or mist is apparent and engineering controls are not feasible, a particulate respirator (NIOSH type N95 or better filters) may be worn. If oil particles (e.g. lubricants, cutting fluids, glycerine, etc.) are present, use a NIOSH type R or P filter. For emergencies or instances where the exposure levels are not known, u...	{ "page_id": 7282047, "title": "Potassium nitrate (data page)" }
The South African Institute for Aquatic Biodiversity (SAIAB), is involved in research, education and in applications of its knowledge and research to African fish fauna, for either economic or conservation benefit. The institute originally established in 1969, was formerly named the JLB Smith Institute of Ichthyology, ...	{ "page_id": 9051520, "title": "South African Institute for Aquatic Biodiversity" }
The Corey–Seebach reaction, or Seebach Umpolung is a name reaction of organic chemistry that allows for acylation by converting aldehydes into lithiated 1,3-dithianes. The lithiated 1,3-dithianes serves as an acyl anion equivalent, undergoing alkylation with electrophiles. The reaction is named in honor of its discover...	{ "page_id": 42671488, "title": "Corey–Seebach reaction" }
and synthetic applications of 2-lithio-1,3-dithianes". The Journal of Organic Chemistry. 40 (2): 231–237. doi:10.1021/jo00890a018. == References ==	{ "page_id": 42671488, "title": "Corey–Seebach reaction" }
In quantum field theory, the Casimir effect (or Casimir force) is a physical force acting on the macroscopic boundaries of a confined space which arises from the quantum fluctuations of a field. The term Casimir pressure is sometimes used when it is described in units of force per unit area. It is named after the Dutch...	{ "page_id": 7555, "title": "Casimir effect" }
example is of two uncharged conductive plates in a vacuum, placed a few nanometers apart. In a classical description, the lack of an external field means that no field exists between the plates, and no force connects them. When this field is instead studied using the quantum electrodynamic vacuum, it is seen that the p...	{ "page_id": 7555, "title": "Casimir effect" }
plate in 1947; this special form is called the Casimir–Polder force. After a conversation with Niels Bohr, who suggested it had something to do with zero-point energy, Casimir alone formulated the theory predicting a force between neutral conducting plates in 1948. This latter phenomenon is called the Casimir effect. P...	{ "page_id": 7555, "title": "Casimir effect" }
has a vastly complex structure, so all calculations of quantum field theory must be made in relation to this model of the vacuum. The vacuum has, implicitly, all of the properties that a particle may have: spin, polarization in the case of light, energy, and so on. On average, most of these properties cancel out: the v...	{ "page_id": 7555, "title": "Casimir effect" }
observe. The Casimir effect for fermions can be understood as the spectral asymmetry of the fermion operator (−1)F, where it is known as the Witten index. === Relativistic van der Waals force === Alternatively, a 2005 paper by Robert Jaffe of MIT states that "Casimir effects can be formulated and Casimir forces can be ...	{ "page_id": 7555, "title": "Casimir effect" }
energies of the standing waves of the cavity. To each and every possible standing wave corresponds an energy; say the energy of the nth standing wave is En. The vacuum expectation value of the energy of the electromagnetic field in the cavity is then ⟨ E ⟩ = 1 2 ∑ n E n {\displaystyle \langle E\rangle ={\tfrac {1}{2}}\...	{ "page_id": 7555, "title": "Casimir effect" }
slot of width a are highly constrained so that the energy E of any one mode is widely separated from that of the next. This is not the case in the large region l where there is a large number of states (about ⁠l/a⁠) with energy evenly spaced between E and the next mode in the narrow slot, or in other words, all slightl...	{ "page_id": 7555, "title": "Casimir effect" }
electric component of the electromagnetic field, and, for brevity, the polarization and the magnetic components are ignored here. Here, kx and ky are the wavenumbers in directions parallel to the plates, and k n = n π a {\displaystyle k_{n}={\frac {n\pi }{a}}} is the wavenumber perpendicular to the plates. Here, n is a...	{ "page_id": 7555, "title": "Casimir effect" }
{\frac {dk_{x}\,dk_{y}}{(2\pi )^{2}}}\sum _{n=1}^{\infty }\omega _{n}\left\|\omega _{n}\right\|^{-s}\,.} In the end, the limit s → 0 is to be taken. Here s is just a complex number, not to be confused with the shape discussed previously. This integral sum is finite for s real and larger than 3. The sum has a pole at s = ...	{ "page_id": 7555, "title": "Casimir effect" }
⟩ A = lim s → 0 ⟨ E ( s ) ⟩ A = − ℏ c π 2 6 a 3 ζ ( − 3 ) . {\displaystyle {\frac {\langle E\rangle }{A}}=\lim _{s\to 0}{\frac {\langle E(s)\rangle }{A}}=-{\frac {\hbar c\pi ^{2}}{6a^{3}}}\zeta (-3)\,.} But ζ(−3) = ⁠1/120⁠ and so one obtains ⟨ E ⟩ A = − ℏ c π 2 720 a 3 . {\displaystyle {\frac {\langle E\rangle }{A}}=-{...	{ "page_id": 7555, "title": "Casimir effect" }
c is the speed of light, A is the area of one of the plates, a is the distance between the two plates In Casimir's original derivation, a moveable conductive plate is positioned at a short distance a from one of two widely separated plates (distance L apart). The zero-point energy on both sides of the plate is consider...	{ "page_id": 7555, "title": "Casimir effect" }
can be adapted to obtain an approximate ⁠R/a3⁠ force (neglecting both skin-depth and higher-order curvature effects). However, in the 2010s a number of authors developed and demonstrated a variety of numerical techniques, in many cases adapted from classical computational electromagnetics, that are capable of accuratel...	{ "page_id": 7555, "title": "Casimir effect" }
and 2021, the same group from Hong Kong University of Science and Technology demonstrated the non-monotonic Casimir force and distance-independent Casimir force, respectively, using this on-chip platform. == Regularization == In order to be able to perform calculations in the general case, it is convenient to introduce...	{ "page_id": 7555, "title": "Casimir effect" }
ω n \| − s {\displaystyle \langle E(s)\rangle ={\frac {1}{2}}\sum _{n}\hbar \|\omega _{n}\|\|\omega _{n}\|^{-s}} is completely unsuited for numerical calculations, but is quite useful in theoretical calculations. In particular, divergences show up as poles in the complex s plane, with the bulk divergence at s = 4. This sum ...	{ "page_id": 7555, "title": "Casimir effect" }
the theme of the Casimir effect. Thus one considers the Hamiltonian of a system as a function of the arrangement of objects, such as atoms, in configuration space. The change in the zero-point energy as a function of changes of the configuration can be understood to result in forces acting between the objects. In the c...	{ "page_id": 7555, "title": "Casimir effect" }
optical dynamical Casimir effect in a dispersion-oscillating fibre. In 2020, Frank Wilczek et al., proposed a resolution to the information loss paradox associated with the moving mirror model of the dynamical Casimir effect. Constructed within the framework of quantum field theory in curved spacetime, the dynamical Ca...	{ "page_id": 7555, "title": "Casimir effect" }
circuit technology based micro- and nanoelectromechanical systems, and so-called Casimir oscillators. In 1995 and 1998 Maclay et al. published the first models of a microelectromechanical system (MEMS) with Casimir forces. While not exploiting the Casimir force for useful work, the papers drew attention from the MEMS c...	{ "page_id": 7555, "title": "Casimir effect" }
Riverside's version of the Usenet physics FAQ. A. Lambrecht, The Casimir effect: a force from nothing, Physics World, September 2002. NASA Astronomy Picture of the Day: Casimir effect (17 December 2006) Simpson, W. M. R; Leonhardt, U. (2015). Forces of the Quantum Vacuum: An introduction to Casimir physics. World Scien...	{ "page_id": 7555, "title": "Casimir effect" }
of Nothing: Vacuums, Voids, and the Latest Ideas About the Origins of the Universe. Pantheon Books. ISBN 978-0-09-928845-9. (Also includes discussion of French naval analogy.) Downling, J. P. (1989). "The Mathematics of the Casimir Effect". Mathematics Magazine. 62 (5): 324–331. doi:10.1080/0025570X.1989.11977464. Pate...	{ "page_id": 7555, "title": "Casimir effect" }
Vivisection (from Latin vivus 'alive' and sectio 'cutting') is surgery conducted for experimental purposes on a living organism, typically animals with a central nervous system, to view living internal structure. The word is, more broadly, used as a pejorative catch-all term for experimentation on live animals by organ...	{ "page_id": 400772, "title": "Vivisection" }
the institution conducting the experiment, and an additional independent person not involved in animal experimentation." === Anti-vivisection movement === Anti-vivisectionists have played roles in the emergence of the animal welfare and animal rights movements, arguing that animals and humans have the same natural righ...	{ "page_id": 400772, "title": "Vivisection" }
of dorsal and ventral spinal nerve roots was achieved by both Magendie, as well as a Scottish anatomist named Charles Bell. Bell used an unconscious rabbit because of "the protracted cruelty of the dissection", which caused him to miss that the dorsal roots were also responsible for sensory information. Magendie, on th...	{ "page_id": 400772, "title": "Vivisection" }
determined that one could only conduct vivisection on animals with the appropriate license from the state, and that the work the physiologist was doing had to be original and absolutely necessary. The stage was set for such legislation by physiologist David Ferrier. Ferrier was a pioneer in understanding the brain and ...	{ "page_id": 400772, "title": "Vivisection" }
was the one operating, and his assistant did have a license. Ferrier and his practices gained public support, leaving the anti-vivisection movement scrambling. They made the moral argument that given recent developments, scientists would venture into more extreme practices to operating on "the cripple, the mute, the id...	{ "page_id": 400772, "title": "Vivisection" }
forms of vivisection by the Japanese, in many cases without anesthesia. Nazi human experimentation involved many medical experiments on live subjects, such as vivisections by Josef Mengele, usually without anesthesia. == See also == == References == == Further reading ==	{ "page_id": 400772, "title": "Vivisection" }
Applied spectroscopy is the application of various spectroscopic methods for the detection and identification of different elements or compounds to solve problems in fields like forensics, medicine, the oil industry, atmospheric chemistry, and pharmacology. == Spectroscopic methods == A common spectroscopic method for ...	{ "page_id": 8199558, "title": "Applied spectroscopy" }
solution (KBr), powder, or film. A solid film is the easiest and most straight forward sample type to test. == Analysis of polymers == Many polymer degradation mechanisms can be followed using IR spectroscopy, such as UV degradation and oxidation, among many other failure modes. === UV degradation === Many polymers are...	{ "page_id": 8199558, "title": "Applied spectroscopy" }
relatively simple spectrum, with few peaks at the carbonyl position (like polyethylene). Oxidation tends to start at tertiary carbon atoms because free radicals here are more stable, so last longer and are attacked by oxygen. The carbonyl group can be further oxidised to break the chain, so weakening the material by lo...	{ "page_id": 8199558, "title": "Applied spectroscopy" }
EDX spectrum of the unaffected elastomer surface spectrum shows a relatively low-oxygen peak compared with the sulfur peak. == See also == == References == Forensic Materials Engineering: Case Studies by Peter Rhys Lewis, Colin Gagg, Ken Reynolds, CRC Press (2004). Peter R Lewis and Sarah Hainsworth, Fuel Line Failure ...	{ "page_id": 8199558, "title": "Applied spectroscopy" }
An equivalent (symbol: officially equiv; unofficially but often Eq) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction. It is an archaic quantity that was used in chemistry and the biological sciences (see Equiva...	{ "page_id": 30875016, "title": "Equivalent (chemistry)" }
elements, holds that an equivalent is the amount of a substance that will react with 1 g (0.035 oz) of hydrogen, 8 g (0.28 oz) of oxygen, or 35.5 g (1.25 oz) of chlorine—or that will displace any of the three. == In medicine and biochemistry == In biological systems, reactions often happen on small scales, involving sm...	{ "page_id": 30875016, "title": "Equivalent (chemistry)" }
Superfecundation is the fertilization of two or more ova from the same menstrual cycle by sperm from the same or different males, whether through separate acts of intercourse or during a single sexual encounter with multiple males (e.g. double penetration). This can potentially result in twin babies that have different...	{ "page_id": 2301322, "title": "Superfecundation" }
suits. == Selected cases involving superfecundation == In 1982, twins who were born with two different skin colors were discovered to be conceived as a result of heteropaternal superfecundation. In 1995, a young woman gave birth to diamniotic monochorionic twins, who were originally assumed to be monozygotic twins unti...	{ "page_id": 2301322, "title": "Superfecundation" }
Zeus. This happens again; this time Leda bears two sons: Castor by Tyndareus and Pollux by Zeus. Alcmene lies with Zeus, who is disguised as her husband Amphitryon; Alcmene later lies with the real Amphitryon and gives birth to two sons: Iphicles by Amphitryon and Heracles by Zeus. Chione lies with both Apollo and Herm...	{ "page_id": 2301322, "title": "Superfecundation" }
The AAAI Conference on Artificial Intelligence (AAAI) is a leading international academic conference in artificial intelligence held annually. It ranks 4th in terms of H5 Index in Google Scholar's list of top AI publications, after ICLR, NeurIPS, and ICML. It is supported by the Association for the Advancement of Artif...	{ "page_id": 24714635, "title": "AAAI Conference on Artificial Intelligence" }
Island, United States AAAI-1996 Portland, Oregon, United States AAAI-1994 Seattle, Washington, United States AAAI-1993 Washington Convention Center, Washington, D.C., United States AAAI-1992 San Jose Convention Center, San Jose, California, United States AAAI-1991 Anaheim Convention Center, Anaheim, California, United ...	{ "page_id": 24714635, "title": "AAAI Conference on Artificial Intelligence" }
Chimie ParisTech, officially École nationale supérieure de chimie de Paris (French pronunciation: [ekɔl nɑsjɔnal sypeʁjœʁ də ʃimi də paʁi]; "National High School of Chemistry of Paris") and also known as ENSCP or Chimie Paris, is a prestigious grande école and a constituent college of PSL Research University specialise...	{ "page_id": 16522635, "title": "Chimie ParisTech" }
one of the first engineering schools in France to do so. In 1923, the school moved to its current location, on the rue Pierre et Marie Curie (in the 5th arrondissement). The buildings were designed and built by Henri-Paul Nénot, architect of the Sorbonne. In 1932, the school became l'Institut de Chimie de Paris (Paris ...	{ "page_id": 16522635, "title": "Chimie ParisTech" }
In quantum physics, the squeeze operator for a single mode of the electromagnetic field is S ^ ( z ) = exp ⁡ ( 1 2 ( z ∗ a ^ 2 − z a ^ † 2 ) ) , z = r e i θ {\displaystyle {\hat {S}}(z)=\exp \left({1 \over 2}(z^{*}{\hat {a}}^{2}-z{\hat {a}}^{\dagger 2})\right),\qquad z=r\,e^{i\theta }} where the operators inside the ex...	{ "page_id": 5119374, "title": "Squeeze operator" }
operators, so one must pay close attention to how the operators are used. There is, however, a simple braiding relation, D ^ ( α ) S ^ ( z ) = S ^ ( z ) S ^ † ( z ) D ^ ( α ) S ^ ( z ) = S ^ ( z ) D ^ ( γ ) , where γ = α cosh ⁡ r + α ∗ e i θ sinh ⁡ r {\displaystyle {\hat {D}}(\alpha ){\hat {S}}(z)={\hat {S}}(z){\hat {S...	{ "page_id": 5119374, "title": "Squeeze operator" }
A a e − A {\displaystyle e^{A}ae^{-A}} . We can now make use of the general equality e A B e − A = ∑ k = 0 ∞ 1 k ! [ A , [ A , … , [ A ⏟ k times , B ] … ] ] , {\displaystyle e^{A}Be^{-A}=\sum _{k=0}^{\infty }{\frac {1}{k!}}[\underbrace {A,[A,\dots ,[A} _{k\,{\text{times}}},B]\dots ]],} which holds true for any pair of ...	{ "page_id": 5119374, "title": "Squeeze operator" }
z \| z \| ∑ k = 0 ∞ \| z \| 2 k + 1 ( 2 k + 1 ) ! = a cosh ⁡ \| z \| − a † e i θ sinh ⁡ \| z \| . {\displaystyle e^{A}ae^{-A}=a\sum _{k=0}^{\infty }{\frac {\|z\|^{2k}}{(2k)!}}-a^{\dagger }{\frac {z}{\|z\|}}\sum _{k=0}^{\infty }{\frac {\|z\|^{2k+1}}{(2k+1)!}}=a\cosh \|z\|-a^{\dagger }e^{i\theta }\sinh \|z\|.} The same result is also obta...	{ "page_id": 5119374, "title": "Squeeze operator" }
The vitalism of the Montpellier medical school, more succinctly called "Montpellier vitalism", is a medical and philosophical school of thought. == History == It emerged in France in the second half of the 18th century under the influence of physicians and philosophers shaped by the intellectual context of the time. Di...	{ "page_id": 78454162, "title": "Montpellier vitalism" }
Bulletin d'histoire et d'épistémologie des sciences de la vie. 14: 25–45. Full text (in French). Rey, Roselyne (2000). Naissance et développement du vitalisme en France de la fin du XVIIe siècle à la fin du XVIIIe siècle. Oxford: University of Oxford, Voltaire Foundation (in French, first ed. 1987). Williams, Elisabeth...	{ "page_id": 78454162, "title": "Montpellier vitalism" }
The biodiversity of Assam, a state in North-East India, makes it a biological hotspot with many rare and endemic plant and animal species. The greatest success in recent years has been the conservation of the Indian rhinoceros at the Kaziranga National Park, but a rapid increase in human population in Assam threatens m...	{ "page_id": 9444754, "title": "Biodiversity of Assam" }
WaaA (gene) may refer to: Lipid IVA 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase, an enzyme	{ "page_id": 38804885, "title": "WaaA (gene)" }
Α sesquisulfide is a compound that has the composition M2S3 where M is the element and S is sulfur. Boron sesquisulfide, B2S3 Aluminium sesquisulfide, Al2S3 Scandium sesquisulfide, Sc2S3 Titanium sesquisulfide, Ti2S3 Chromium sesquisulfide, Cr2S3 Gallium sesquisulfide, Ga2S3 Arsenic sesquisulfide, As2S3 Yttrium sesquis...	{ "page_id": 75832730, "title": "Sesquisulfide" }
KdtA may refer to: Lipid IVA 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase, an enzyme	{ "page_id": 38804890, "title": "KdtA" }
3-deoxy-D-manno-oct-2-ulosonic acid transferase may refer to: Lipid IVA 3-deoxy-D-manno-octulosonic acid transferase (KDO)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase (KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase (KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase	{ "page_id": 38804893, "title": "3-deoxy-D-manno-oct-2-ulosonic acid transferase" }
3-deoxy-manno-octulosonic acid transferase may refer to: Lipid IVA 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase, an enzyme (KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulos...	{ "page_id": 38804894, "title": "3-deoxy-manno-octulosonic acid transferase" }
ANSI/ASA S1.1-2013, published by the American National Standards Institute (ANSI), is the current American National Standard on Acoustical Terminology. ANSI S1.1 was first published in 1960 and has its roots in a 1942 standard published by the American Standards Association, the predecessor of ANSI. It includes the fol...	{ "page_id": 41950622, "title": "ANSI/ASA S1.1-2013" }
In cell biology, a biological pathway is a series of interactions among molecules in a cell that leads to a certain product or a change in the cell. Such a pathway can trigger the assembly of new molecules, such as a fat or protein. Pathways can also turn genes on and off, or spur a cell to move. Some of the most commo...	{ "page_id": 26615202, "title": "Biological pathway" }
for each protein in the human proteome (the last release was #9 in 2010). PANTHER (Protein ANalysis THrough Evolutionary Relationships) is a large curated biological database of gene/protein families and their functionally related subfamilies that can be used to classify and identify the function of gene products. TRAN...	{ "page_id": 26615202, "title": "Biological pathway" }
In ecology, invader potential is the qualitative and quantitative measures of a given invasive species probability to invade a given ecosystem. This is often seen through climate matching. There are many reasons why a species may invade a new area. The term invader potential may also be interchangeable with invasivenes...	{ "page_id": 3612067, "title": "Invader potential" }
shown directly through Tilman's R* rule. Those with less needs can competitively exclude those with more complex needs and take over an area. And finally, species with high reproduction rate and low defense to natural enemies have a better chance of invading other areas. All of these are reasons why species may thrive ...	{ "page_id": 3612067, "title": "Invader potential" }
salt marshes were surveyed for changes following this invasion. This study specifically looked at how human habitat alteration led to the invasion success of this species. Shoreline development, nutrient enrichment, and salinity reduction were all human made changes that contributed to the species ability to invade. ==...	{ "page_id": 3612067, "title": "Invader potential" }
biotic and abiotic factors. Invasion potential has a great impact on whether or not the invasive organism will survive these biotic or abiotic factors. The species' ability to adapt to the new conditions will contribute to the success of the particular invasion. In the majority of cases, a small subset of introduced sp...	{ "page_id": 3612067, "title": "Invader potential" }
A protein mimetic is a molecule such as a peptide, a modified peptide or any other molecule that biologically mimics the action or activity of some other protein. Protein mimetics are commonly used in drug design and discovery. == Types of mimetics == There are a number of different distinct classes of protein mimetics...	{ "page_id": 44637603, "title": "Protein mimetic" }
Manganese acetate can refer to: Manganese(II) acetate Manganese(III) acetate	{ "page_id": 23666084, "title": "Manganese acetate" }
In condensed matter physics and materials chemistry, a topological superconductor is a material that conducts electricity with zero electrical resistivity, and has non-trivial topology which gives it certain unique properties. These materials behave as superconductors that feature exotic edge states, known as Majorana ...	{ "page_id": 79568294, "title": "Topological superconductor" }
A limepit is either a place where limestone is quarried, or a man-made pit used to burn lime stones in the same way that modern-day kilns and furnaces constructed of brick are now used above ground for the calcination of limestone (calcium carbonate, CaCO3) and by which quicklime (calcium oxide, CaO) is produced, an es...	{ "page_id": 61349287, "title": "Limepit" }
Bedouin-Arab culture in Israel, the limepit was dug to a depth of about 2.5 metres (8.2 ft) and about 3 metres (9.8 ft) in diameter. By all appearances, the pit was made after the same basic principle used in a "Dakota fire pit," which is made with an air inlet at the base, allowing for air-ventilation, but on a larger...	{ "page_id": 61349287, "title": "Limepit" }
in plastering home-made cisterns (in making them impermeable by adding thereto a pozzolanic agent) was especially important. This enabled them to collect the winter run-off of rain water and to have it stored for later use, whether for personal or agricultural needs. Lime is also an important component in the productio...	{ "page_id": 61349287, "title": "Limepit" }
of lime would fetch 40 grush on the Jerusalem market in the early 1880s. In Israel, the principal fuel used to keep the lime-kiln burning was the dried brushwood of prickly burnet (Sarcopoterium spinosum) and savory (Satureja thymbra), where often camel loads of this dried wood would be hauled to the lime-kiln. Monolit...	{ "page_id": 61349287, "title": "Limepit" }
also == Lime kiln Lime plaster Qadad (Method of waterproofing cisterns in South Arabia) == References == == Bibliography ==	{ "page_id": 61349287, "title": "Limepit" }
In optics, nonclassical light is light that cannot be described using classical electromagnetism; its characteristics are described by the quantized electromagnetic field and quantum mechanics. The most common described forms of nonclassical light are the following: Photon statistics of nonclassical Light is sub-Poisso...	{ "page_id": 5905830, "title": "Nonclassical light" }
would not describe probabilities of mutually exclusive states." == References == === Citations === === Citation bibliography === === General references === Glauber, Roy J. (1963-09-15). "Coherent and Incoherent States of the Radiation Field". Physical Review. 131 (6). American Physical Society (APS): 2766–2788. doi:10....	{ "page_id": 5905830, "title": "Nonclassical light" }
Bias in the introduction of variation ("arrival bias") is a theory in the domain of evolutionary biology that asserts biases in the introduction of heritable variation are reflected in the outcome of evolution. It is relevant to topics in molecular evolution, evo-devo, and self-organization. In the context of this theo...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
(origination) missing from classical treatments of evolution as a process of shifting frequencies of available alleles. This recognition is evident in the emergence of origin-fixation models that depict evolution as a 2-step process of origination and fixation (by drift or selection), with a rate specified by multiplyi...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
book by Raff and Kaufman (1983) and conference volumes edited by Bonner (1982) and Goodwin, et al (1983) — wrote that "The whole thrust of the developmentalist approach to evolution is to explore the possibility that asymmetries in the introduction of variation at the focal level of individual phenotypes, arising from ...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
the "developmental constraints" argument simply restates the idea that development shapes variation, without explaining how such preferences prevail against the pressure of selection. Mayr (1994) insisted that developmentalist thinking was "hopelessly mixed up" because development is a proximate cause and not an evolut...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
evolution by mediating biases in introduction. The theory, which applies to both mutational and developmental biases, addresses how such preferences can be effective in shaping the course of evolution even while strong selection is at work. Systematic evidence for predicted effects of introduction biases first began to...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
on the left than on the right. Then the dual proposal-acceptance process will show both an upward bias due to a bias in acceptance, and a leftward bias due to a bias in proposal. If the landscape is rugged, the ascent will end on a local peak that (due to the proposal bias) will tend to be to the left of the starting p...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
that some phenotypes are more findable than others due to mutational effects, and such effects may strongly shape the distribution of evolved phenotypes. The application of the theory to problems in evo-devo and self-organization relies formally on the concept of a genotype-phenotype (GP) map. The genetic code, for exa...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
right options j {\displaystyle j} and k {\displaystyle k} (respectively) in the Yampolsky-Stoltzfus model is given by the following: where μ i j {\displaystyle \mu _{ij}} (or μ i k {\displaystyle \mu _{ik}} ) and s i j {\displaystyle s_{ij}} (or s i k {\displaystyle s_{ik}} ) are the mutation rate and selection coeffic...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
mutation bias is expected to be strongest when μ N << 1 {\displaystyle \mu N<<1} but to fall off as μ N {\displaystyle \mu N} becomes large. The influence of mutation under varying degrees of clonal interference can be quantified precisely using the regression method of Cano, et al (2022). Suppose that the expected num...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
set of possible steps each with a probability p i {\displaystyle p_{i}} , then the chance of parallelism is given by summing the squares, P p a r a = ∑ i p i 2 {\displaystyle P_{para}=\sum _{i}p_{i}^{2}} . It follows from the definition of the variance V {\displaystyle V} or the coefficient of variation c v {\displayst...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
effects of mutation and selection in a hidden way (because, in practice, n {\displaystyle n} reflects the set of paths that are sufficiently favored by selection and sufficiently mutationally likely to be observed). === Longer-term effects: trends, navigability, and findability === For a systematic view of long-term ef...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
other destinations. For a given destination, the evolvability-to or findability depends on this collection of paths relative to competing paths. Each collection has some total size, i.e., there may be many or few paths leading to a destination. A fitness landscape that may include many peaks and paths. Depending on its...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
a particular direction along an axis of composition. The influence of transition-transversion bias has been explored using empirical fitness landscapes for transcription factor binding sites. Each landscape is based on generating thousands of different 8-nucleotide fragments and measuring how well they bind to a partic...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
Tryptophan has 1: Leucine is more findable because there are more mutational paths from non-Leucine genotypes. This idea can be applied to the way that RNA folds (considered as phenotypes) map to RNA sequences. For instance, evolutionary simulations show that the RNA folds with more sequences are more findable, and thi...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
initiative, or direction (supplied by selection)—, so that the laws of variation "bear no relation" to the structures built by selection. Development imposes prior constraints on form. In this folk theory, "selection may decide the winner of a given game but development non-randomly defines the players." This theory ap...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
mutation pressure explored (and rejected) by Haldane and others, variational dispositions under the theory of arrival biases do not depend on neutral evolution and do not require high mutation rates. Graduated biases can have graduated effects. In contrast to what is implied by the language of "constraints" or "limits"...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
aggregation over genotypes (see Box 2 of ). In addition to these direct implications, some more sophisticated or indirect implications have emerged in the literature. Non-causal associations induced by mutation and selection. Due to a dual dependence on mutation and selection, the distribution of adaptive changes may s...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
(see also ). Biases in introduction are expected to influence evolution whether neutral or adaptive, but an effect on neutral evolution is not considered intuitively surprising or controversial, and so is not given much attention. Instead, accounts of evidence focus on mutation-biased adaptation, because this highlight...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
the hotspot from AR2 and add it to Pf0-2x, without changing the encoded amino acid sequence. This reversed the qualitative pattern of outcomes, so that the modified AR2 (engineered to remove the hotspot) adapted via diverse changes, while the modified Pf0-2x with the engineered hotspot adapted via the A289C change 80% ...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
which are not correlated (see Ch. 9 of ). As explained above, the influence of the mutation spectrum on the spectrum of adaptive changes can be captured in a single parameter β {\displaystyle \beta } , defined as a coefficient of binomial regression of observed counts on the expected counts from a mutational model. Bas...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
to focus on trusted cases of adaptation in which the proposed functional effects of putative adaptive mutations have been verified using techniques of genetics. Payne, et al looked for an effect of transition bias among causative mutations for antibiotic resistance in clinically identified strains of Mycobacterium tube...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
2.7-fold enrichment relative to the null expectation of 1:2 (the ratio of paths, which is less sensitive to extreme values, is 27:28, a 2-fold enrichment). Thus, this study shows that a bias toward transitions is observed in well known cases of parallel adaptation in diverse taxa, including animals and plants. Finally,...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
unequal or directional "mutation pressure" but which are not plausibly explained as evolution by mutation pressure, suggesting instead the need for a theory of mutational biases in introduction; the suggestion emerging from the paleobiology debate of the 1980s that, in the hierarchical expansion of evolutionary causati...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
tendencies may influence evolution under some conditions. For instance, the theory of mutation pressure applies when mutation rates are high and unopposed by selection, thus it has a limited range of applications. The theory of evolutionary quantitative genetics can be applied very broadly to the evolution of quantitat...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
from a short-term process of shifting frequencies of available alleles. In this process, mutation is typically unimportant except when the focus is on low-frequency alleles maintained by deleterious mutation pressure (see Population genetics: Mutation), e.g., Edwards (1977) addressed theoretical population genetics wit...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
echo in contemporary sources, e.g., in a US white paper endorsed by SSE, SMBE, ASN, ESA and other relevant professional societies, Futuyma, et al (2001) state, as fact, that evolution is shifting gene frequencies, identifying the main causes of "evolution" (so defined) as selection and drift (figure). However, toward t...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
may occasionally jump to another phenotype. From the starting network of genotypes encoding phenotype P0, there are mutations leading to genotypic networks for P1 and P2. However, the number of mutations leading from the starting network to P2 is 4 times higher illustrating the idea that, for a given developmental-gene...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }
precisely is a matter of the total surface area of the network accessible to other high-fitness phenotypes). In this case, P0 is more findable than P1 and P2 because it has twice as many genotypes. The variational bias toward more numerous phenotypes is called "phenotype bias" by Dingle, et al (2022) (see also ). This ...	{ "page_id": 72359343, "title": "Bias in the introduction of variation" }

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.