All articles starting with K
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Klebsiella pneumoniae
Klebsiella pneumoniae, also called hvKp or cKP, is a gram-negative encapsulated gut bacterium and ESKAPE pathogen causing pneumonia, bacteremia, and liver abscess; carbapenem-resistant strains ranked first in the 2024 WHO priority pathogen list.
Kleefstra syndrome
Kleefstra syndrome (KLEFS1, 9q34.3 microdeletion syndrome) is a rare autosomal-dominant neurodevelopmental disorder caused by EHMT1 haploinsufficiency, with intellectual disability, severe speech delay, hypotonia, heart and renal defects, and a distinctive face.
Kleene star
The Kleene star, also called Kleene closure, is an operation that maps a language L to all strings formed by concatenating zero or more strings from L.
Kleene's O
Kleene's O is a set of natural numbers, called ordinal notations, that names the constructive ordinals; it was introduced by Stephen Cole Kleene in 1938.
Kleene's recursion theorem
Kleene's recursion theorem, also called the fixed point theorem, is a result in computability theory published by Stephen Kleene in 1938, implying self-reproducing programs called quines.
Kleenex
Kleenex is a brand of facial tissue made by Kimberly-Clark, launched in the United States in 1924 and a standard example of a genericized trademark.
Kleidi Roman bridge (Emathia)
Kleidi Roman bridge (Ρωμαϊκή Γέφυρα στο Κλειδί, Klidhi bridge), a Late Roman multi-arch bridge near Kleidi, Emathia, Greece, on a Via Egnatia branch over the Loudias; only one arch (17.14 m span) survives.
Kleihauer–Betke test
Kleihauer–Betke test (Kleihauer test, acid elution test): 1957 maternal blood assay detecting acid-resistant fetal HbF cells to quantify fetomaternal hemorrhage and guide Rho(D) immune globulin dosing in Rh D-negative women.
Klein bottle
The Klein bottle is a closed, one-sided surface with no inside or outside, described by Felix Klein in 1882 and impossible to place in space without self-intersection.
Klein four-group
The Klein four-group is the smallest non-cyclic group, a 4-element abelian group in which every element is its own inverse, isomorphic to C2 × C2.
Klein Karoo Nasionale Kunstefees
The Klein Karoo Nasionale Kunstefees (KKNK) is an annual Afrikaans-language arts festival held for eight days around Easter in Oudtshoorn, South Africa, first staged in 1995.
Klein Kubiak
Klein Kubiak, son of Gary Kubiak and brother of Klint and Klay, is the Dallas Cowboys' National Scout/Special Projects, a former Rice wide receiver who joined Dallas in 2019 after five years with the Denver Broncos.
Klein tunneling of light
Klein tunneling of light is the optical analog of the relativistic quantum effect in which light crosses a barrier with perfect transmission, realized through refractive-index patterning in photonic systems.
Klein–Goldberger model
The Klein–Goldberger model is a small Keynesian econometric model of the United States economy, published by Lawrence Klein and Arthur Goldberger in 1955 and used for forecasting.
Klein–Gordon equation
The Klein–Gordon equation is the relativistic wave equation for free spinless particles, proposed in 1926 and describing scalar particles like the pion and Higgs boson.
Klein–Nishina formula
The Klein–Nishina formula, also called the Klein–Nishina cross section, is the quantum-mechanical expression for the differential cross section of Compton scattering, derived by Oskar Klein and Yoshio Nishina in 1928.
Kleine Aster
"Kleine Aster" ("Little Aster") is a 1912 poem by German physician-poet Gottfried Benn, opening poem of Morgue und andere Gedichte and a key text of Expressionism.
Kleine Scheidegg
Kleine Scheidegg, a 2,061 m mountain pass in the Bernese Oberland between the Eiger and Lauberhorn, is the junction of the Wengernalp Railway and the Jungfrau Railway to Jungfraujoch, and a hiking and ski hub.
Kleine–Levin syndrome
Kleine–Levin syndrome, also called Sleeping beauty syndrome, is a rare neuropsychiatric sleep disorder with recurring bouts of severe sleepiness, cognitive impairment, and altered behavior, usually beginning in adolescence.
Kleiner Mann – was nun?
Kleiner Mann – was nun? (Little Man, What Now?) is Hans Fallada's 1932 Depression-era novel about clerk Johannes Pinneberg, his wife Lämmchen and their slide into unemployment in Berlin, a New Objectivity bestseller filmed in 1933, 1934, 1967, and 1973.
Kleiner Perkins
Kleiner Perkins, formerly Kleiner Perkins Caufield & Byers, is a venture capital firm founded in 1972 and based in Menlo Park, California, known for early bets on Genentech, Netscape, Amazon, and Google.
Kleinian group
A Kleinian group is a discrete group of Möbius transformations of the sphere, equivalently isometries of hyperbolic 3-space, created by Poincaré and Klein in the 1880s.
Kleinlokomotive
Kleinlokomotive, or Kleinlok, is a German classification for small, low-power shunting locomotives created by the Deutsche Reichsbahn-Gesellschaft in 1931; the best known is the Köf II.
Kleinzerbst
Kleinzerbst, a village in Aken (Elbe), Saxony-Anhalt, site of a Germanic cemetery of the late La Tene and early Roman Imperial periods, published by Erika Schmidt-Thielbeer in 1998, with Neolithic and Bronze Age finds and a 1944 war-crimes case.
Kleisli category
A Kleisli category is a category built from a monad, keeping the base category's objects and taking morphisms X to Y to be morphisms X to T(Y).
Kleist Prize
The Kleist Prize (Kleist-Preis) is a renowned German literary award presented by the Heinrich von Kleist Society, first awarded in 1912 and revived in 1985 after interruption in 1933.
Kleitor (settlement)
Kleitor (Κλείτωρ, Cleitor), an ancient Greek polis of northwestern Arcadia (Azania), near modern Kleitoria. Walled Hellenistic city with theatre; Achaean League member, besieged by the Aetolians in 220 BC; inhabited into late antiquity.
Klemens von Metternich
Klemens Wenzel Lothar von Metternich (1773-1859) was Austrian foreign minister 1809-1848 and state chancellor from 1821, presided over the Congress of Vienna, shaped the Concert of Europe, and fell in the 1848 revolution.
Klement Gottwald
Klement Gottwald (1896–1953), Czech communist leader, KSČ general secretary from 1929, prime minister 1946–1948, and first communist president of Czechoslovakia from 1948, architect of the February 1948 coup and the Stalinist regime, died nine days after Stalin.
Klenie Bimolt
Klenie Bimolt (Klena Geertje Bimolt, born 1945) is a Dutch breaststroke swimmer, 1964 Tokyo Olympic silver medalist in the 4x100 m medley relay and 1962 European silver medalist, who also competed at Mexico 1968.