All articles starting with H
20,046 articles
Heteropoda venatoria
Heteropoda venatoria, the pantropical huntsman or giant crab spider (basionym Aranea venatoria), is a large Sparassidae spider from tropical Asia, introduced worldwide, with a 7–12 cm leg span, webless nocturnal cockroach hunting, and a painful but non-dangerous bite.
Heteropogon
Heteropogon (tanglehead) is a genus of about four to six tropical Andropogoneae grasses, type species H. contortus (black speargrass), with twisted hygroscopic awns, pungent calluses, pantropical savanna distribution, and non-monophyletic circumscription.
Heteropogon contortus
Heteropogon contortus (black speargrass, tanglehead, pili grass) is a tufted perennial Poaceae grass of the seasonally dry tropics, a major Queensland pasture grass whose barbed, twisted-awned seeds injure livestock and make it invasive in Florida.
Heterosexism
Heterosexism: ideological system denying and stigmatizing nonheterosexual behavior, identity, and relationships; analogous to sexism and racism; distinct from individual homophobia; also called institutional antigay prejudice.
Heterosexuality
Heterosexuality, also called being straight, is the sexual orientation of enduring attraction to the other sex or another gender; the most common self-reported orientation, with a history as a concept and links to heterosexism.
Heterosis
Heterosis, also called hybrid vigor or outbreeding enhancement, is the superior performance of hybrid offspring over their parents on traits such as yield, growth rate, and fertility.
Heterospory
Heterospory is the production of two kinds of spores by the sporophytes of land plants: male microspores and larger female megaspores. It first evolved in the Devonian period.
Heterospory in ferns
Heterospory in ferns: production of microspores and megaspores with separate male and female gametophytes, found only in the water fern order Salviniales (Marsileaceae, Salviniaceae), evolved independently of lycophyte and seed plant heterospory.
Heterosynaptic plasticity
Heterosynaptic plasticity: lasting synaptic strength changes at synapses not active during induction, also called modulatory input-dependent plasticity. It counteracts Hebbian runaway dynamics, stabilizes synaptic weights, and supports long-term memory maintenance.
Heterotardigrada
Heterotardigrada (Marcus, 1927) is one of the two major tardigrade classes, sister to Eutardigrada, defined by a lateral cirrus, with orders Arthrotardigrada and Echiniscoidea; Arthrotardigrada may be paraphyletic.
Heterotic string theory
Heterotic string theory is a class of closed superstring theories in which left- and right-moving modes differ, combining the 26-dimensional bosonic string with the 10-dimensional superstring. It was constructed at Princeton in 1984.
Heterotis
Heterotis names two valid genera: Heterotis Benth. (1849), an African Melastomataceae plant genus with 5-7 species, and Heterotis Rüppell 1829, a monotypic arapaimid fish genus containing the African bonytongue Heterotis niloticus.
Heterotis niloticus
Heterotis niloticus, the African bonytongue or African arowana, is a large obligate air-breathing osteoglossiform fish native to Sahelo-Sudanese African river basins, introduced elsewhere, IUCN Least Concern, and used in fisheries and aquaculture.
Heterotopia (space)
Heterotopia (French: hétérotopie) is Michel Foucault's concept of a real 'counter-site' that represents, contests, and inverts other spaces. Introduced in 1966–67, detailed in the 1984-published lecture 'Des espaces autres', and widely applied across geography, architecture, and cultural studies.
Heterotopic sebaceous glands
Heterotopic sebaceous glands, also called ectopic sebaceous glands or Fordyce spots, are hair-follicle-free oil glands at mucosal sites such as the lips, buccal mucosa, and genitals; benign, present in about 80% of adults, ICD-11 ED91.0.
Heterotopic transplantation
Heterotopic transplantation is a surgical approach that implants an organ graft at a non-anatomical site while leaving the native organ in place, as in the piggyback heart transplant.
Heterotroph
Heterotroph: organism obtaining carbon and energy from organic compounds made by autotrophs; includes all animals, fungi, most bacteria; spans consumers, detritivores, chemoheterotrophs, and photoheterotrophs.
Heterozygote
Heterozygote (heterozygous): an individual carrying two different alleles at a gene locus, one from each parent. Covers dominance, carriers, heterozygote advantage such as sickle-cell malaria resistance, and molecular heterosis.
Hethum I of Armenia
Hethum I (Հեթում Ա) was king of the Armenian Kingdom of Cilicia from 1226 to 1270, founder of the Hethumid dynasty and ally of the Mongol Empire.
Hethum II of Armenia
Hethum II (Հեթում Բ) was king of the Armenian Kingdom of Cilicia in several reigns between 1289 and 1303, and was assassinated with his nephew Leo III in 1307.
Hetian
Hotan Prefecture (和田地区, Uyghur خوتەن ۋىلايىتى) is a prefecture of southern Xinjiang, China, seat Hotan City; 247,800 km², 2.44 million people (2020), 93% minorities, ten county-level units after 2024.
Hetianhe Gas Field
Hetianhe Gas Field (和田河气田) is a carbonate gas field in the Tarim Basin of Xinjiang, northwest China, in the Taklamakan Desert and operated by PetroChina's Tarim Oilfield Company.
Hetpet Regio
Hetpet Regio is a 1,080-km-wide bright region (regio) on Titan near 22°S, approved by the IAU in 2012 and named for an Egyptian personification of happiness, where Cassini saw a rainfall-linked brightening in 2010-2011.
Hetton-le-Hole
Hetton-le-Hole is a former coal-mining town in Sunderland, Tyne and Wear, England, also called Heppedune. Known for Hetton Colliery (1822–1950) and Stephenson's 1822 Hetton Colliery Railway to the River Wear.
Hetty Balkenende
Hetty Balkenende, Dutch swimmer and synchronized swimmer of the 1950s-1960s; 1954 European silver in the 4x100 m freestyle relay, 1955 medley relay European record, and 1960 national duet champion with Nienke te Riet of club ZAR Amsterdam; distinct from Prime Minister Jan Peter Balkenende.
Hetty Green
Hetty Green, born Henrietta Howland Robinson and called the Witch of Wall Street, was an American investor who turned a $5 million inheritance into $100 million or more by 1916.
Hetty Wainthropp Investigates
Hetty Wainthropp Investigates is a British crime comedy-drama starring Patricia Routledge as a 60-year-old Lancashire woman who becomes a private detective, airing on BBC One from 1996 to 1998.
Hetu Ala
赫图阿拉故城 (Hetu Ala), a mountain city in Xinbin, Fushun, Liaoning; Nurhaci's birthplace and capital where he founded Later Jin in 1616, first of the Qing's three capitals outside the pass, now a 4A site and national heritage monument.
Hetz Ventures
Hetz Ventures is a Tel Aviv-based venture capital firm investing in Israeli early-stage startups in cybersecurity, data engineering, and AI infrastructure, managing close to $500 million.
Hetzer
The Hetzer, formally the Jagdpanzer 38(t), was a German light tank destroyer of World War II, produced from April 1944 in Prague with 2,584 built by war's end.