All articles A–Z
519,064 articles
Anacostia
Anacostia, historic neighborhood in Southeast Washington, D.C. east of the Anacostia River, established 1854; name from the Nacotchtank people; home of Frederick Douglass's Cedar Hill and the Smithsonian Anacostia Community Museum.
Anacostia River
The Anacostia River is a 9-mile tidal Potomac tributary in Washington, D.C. and Maryland, once heavily polluted by industry and sewage overflows, now improving through DC Water's tunnel project and sediment cleanup.
Anacreon
Anacreon (Ἀνακρέων), Ionian lyric poet of Teos, 6th–early 5th century BCE, court poet of Polycrates of Samos and Hipparchus of Athens; known for love and wine songs, surviving only in fragments, plus the spurious 1554 Anacreontea.
Anactorium
Anactorium (Ἀνακτόριον, Anaktorion), ancient Corinthian colony in Acarnania on the Ambracian Gulf near Ag. Petros; held Actium and Apollo's sanctuary, captured by Acarnanians in 425 BCE, absorbed into Nicopolis by Augustus.
Anacusis
Anacusis (anakusis, anacusia) is total deafness, complete absence of auditory perception in one or both ears; ICD-11 code MB40.2, defined as hearing loss above 120 dB by some sources.
Anacyclosis
Anacyclosis is a theory that political constitutions pass through a fixed sequence of regime types. Polybius laid out this cycle in his Histories in the second century BCE.
Anadara tuberculosa
Anadara tuberculosa, the pustulose ark or piangua (concha negra), is an eastern Pacific mangrove ark clam from Baja California Sur to Tumbes, Peru; a protein-rich, heavily exploited food bivalve of Rhizophora roots, not IUCN evaluated.
Anadarko Petroleum
Anadarko Petroleum was an American independent oil and natural gas producer headquartered in The Woodlands, Texas, operating from 1986 until Occidental Petroleum acquired it in 2019.
Anadenanthera
Anadenanthera (yopo, cebil, angico) is a tropical American legume tree genus with four accepted species; A. peregrina seeds yield the classic hallucinogenic snuff, A. colubrina supplies timber and tannins.
Anadenanthera peregrina
Anadenanthera peregrina (yopo, cohoba, niopo, paricá) is a Fabaceae tree native from the Caribbean to southern tropical South America whose crushed seeds yield the classic hallucinogenic snuff; IUCN Least Concern, genus of two species with A. colubrina.
Anadia
Anadia is a genus of small Neotropical lizards in the family Gymnophthalmidae, established in 1845, with 19 species ranging from Costa Rica through Colombia to Venezuela, Ecuador, and Guyana.
Anadol
Anadol was a passenger car brand produced by the Turkish company Otosan from 1966 to the mid-1980s, the first domestically branded automobile mass-produced in Turkey.
Anadolu Efes S.K.
Anadolu Efes S.K., or Anadolu Efes Sports Club, is a professional basketball club from Istanbul, Turkey, founded in 1976 as Efes Pilsen; it won back-to-back EuroLeague championships in 2021 and 2022.
Anadolu Group
Anadolu Group is a family-owned Turkish conglomerate founded in Istanbul in 1950 by Kamil Yazıcı and İzzet Özilhan, spanning beer, soft drinks, retail, and automotive.
Anadyr
The Anadyr is a river in the Chukotka Autonomous Okrug of northeastern Siberia, Russia, that is the second largest to empty into the Bering Sea after the Yukon.
Anadyr (Анадырь) (town)
Anadyr (Анадырь), founded 1889 as Novo-Mariinsk, is the capital and easternmost city of Russia's Chukotka Autonomous Okrug, on the Anadyr Estuary; about 13,500-16,000 residents, airport across the estuary, no road links to the rest of Russia.
Anaemia in chronic kidney disease
Anemia in chronic kidney disease (anemia of renal disease): low hemoglobin from reduced erythropoietin and disordered iron metabolism, affecting over 50% of CKD G4–G5; treated with iron, ESAs, and oral HIF-PHIs per KDIGO 2026.
Anaemia of prematurity
Anaemia of prematurity (AOP, ICD-11 KA8B), the hemoglobin fall in preterm infants from delayed erythropoiesis, low erythropoietin, and phlebotomy loss; nadir 7-8 g/dL at 4-6 weeks; TOP and ETTNO trials found higher transfusion thresholds gave no neurodevelopmental benefit.
Anaerobe
Anaerobe (ISSN 1075-9964) is a peer-reviewed Elsevier microbiology journal founded in 1995, official journal of the Anaerobe Society of the Americas, covering strict anaerobes in infection, microbiomes, and industry.
Anaerobic digestion
Anaerobic digestion: microbial breakdown of organic waste without oxygen, producing biogas (50–75% methane) and digestate; used for manure, sludge, and food waste, with lower life-cycle impacts than composting or landfilling.
Anaerobic exercise
Anaerobic exercise: intense activity powered without oxygen by the ATP-CP and glycolytic systems, e.g. sprints and heavy lifting; measured by the Wingate test, causes fatigue via inorganic phosphate, trained through HIIT above 80% max heart rate.
Anaerobic fermentation
Anaerobic fermentation is a biochemical process in which microorganisms break down organic substrates into products such as ethanol, lactic acid, and hydrogen without oxygen, underpinning biofuel and industrial production.
Anaerobic filter
An anaerobic filter is a packed-bed wastewater reactor where microorganisms attached to stationary media break down organic matter without oxygen, producing biogas; developed by Young and McCarty in the 1960s.
Anaerobic lagoon
Anaerobic lagoon: an earthen impoundment treating livestock manure and wastewater without oxygen, also called a covered lagoon digester when capped for methane capture; sized at 0.04–0.30 kg/m³/d loading, 2.4–6 m deep.
Anaerobic membrane bioreactor
An anaerobic membrane bioreactor (AnMBR) is a wastewater treatment system pairing anaerobic digestion with membrane filtration, first introduced in South Africa in the 1980s and used mainly for industrial wastewater.
Anaerobic nitric oxide reductase transcription regulator
NorR (anaerobic nitric oxide reductase transcription regulator, gene norR) is a sigma-54-dependent bacterial enhancer-binding protein that senses NO via a non-haem iron center and activates the norVW NO-detoxification operon in E. coli and other proteobacteria.
Anaerobic organism
Anaerobic organism: microbe growing without molecular oxygen, from strict anaerobes (Clostridium, methanogens) to facultative and microaerophilic bacteria; defined by oxygen tolerance class, fermentation or anaerobic respiration with acceptors like sulfate, nitrate, and CO2, and specialized culturing methods.
Anaerobic oxidation of methane
Anaerobic oxidation of methane (AOM), or DAMO, is microbial methane oxidation without oxygen, performed by ANME archaea via reverse methanogenesis and NC10 bacteria, coupled to sulfate, nitrate, nitrite, or metal oxides in anoxic sediments and waters.
Anaerobic respiration
Anaerobic respiration: cellular respiration using an electron transport chain with a non-oxygen terminal acceptor such as nitrate, sulfate, CO2, Fe(III), or Mn(IV); yields 5–36 ATP per glucose, less than aerobic respiration but more than fermentation.
Anaerobiosis
Anaerobiosis: the absence or paucity of oxygen in an environment. Coined by Pasteur from butyric fermentation; drives anaerobic respiration, fermentation, anaerobic infections, sprint metabolism, and biogas-producing anaerobic digestion.