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Altered States
Altered States (1980) is Ken Russell's American science fiction film, adapted by Paddy Chayefsky (credited as Sidney Aaron) from his 1978 novel, starring William Hurt as a scientist whose sensory deprivation and hallucinogen experiments transform him physically.
AlterG
AlterG is an American medical device company, a subsidiary of Lifeward since 2023, whose anti-gravity treadmill uses differential air pressure to reduce body weight during rehabilitation.
Alteria Capital
Alteria Capital is a Mumbai-based Indian venture debt firm founded in 2017 by Vinod Murali and Ajay Hattangdi that lends to venture capital-backed startups rather than taking equity stakes.
Altermagnetic spintronics
Altermagnetic spintronics is the branch of spintronics that exploits altermagnets, magnetic materials with zero net magnetization but ferromagnet-like spin-polarized currents, named in 2022 and investigated for memory, logic-in-memory, and ultrafast devices.
Altermagnetism
Altermagnetism is a recently identified third basic magnetic phase in which materials have zero net magnetization like an antiferromagnet but spin-split bands like a ferromagnet.
Altern-8
Altern-8 were an English rave duo formed in Stafford in 1990, known for performing in chemical-warfare suits and for the UK number 3 hit "Activ 8 (Come with Me)".
Alternant hydrocarbon
An alternant hydrocarbon is a conjugated hydrocarbon containing no odd-membered rings, so its carbon atoms split into two alternating sets; naphthalene is one, while azulene is nonalternant.
Alternanthera
Alternanthera (joyweed) is a genus of 80–200 Amaranthaceae herbs, mostly American tropics, with opposite leaves, head-like inflorescences, pseudostaminodes, medicinal and aquarium species, and the invasive alligatorweed.
Alternanthera philoxeroides
Alternanthera philoxeroides, alligator weed or alligatorweed (pig weed), an amphibious Amaranthaceae herb from southern South America; invasive floating-mat aquatic weed in the USA (since 1897), China (since 1892), and Australia, spread by vegetative fragments.
Alternanthera sessilis
Alternanthera sessilis (sessile joyweed, dwarf copperleaf, mukunuwenna), Amaranthaceae herb with green and red cultivars; edible medicinal weed of tropical Asia, Australia, and tropical America, studied for antioxidant, analgesic, antihyperglycemic, and hepatoprotective effects, also an EPPO-listed invasive weed.
Alternaria
Alternaria, a Pleosporaceae fungal genus (A. alternata, A. brassicae), comprises saprobic, endophytic, and plant-pathogenic species producing over 70 mycotoxins, causing crop leaf spots and blights, and contaminating food and indoor environments.
Alternaria alternata
Alternaria alternata (Torula alternata, A. tenuis) is an ascomycete fungus, NCBI taxon 5599, that is saprophytic, endophytic, allergenic, and pathogenic; seven host-selective-toxin pathotypes with toxin genes on conditionally dispensable chromosomes.
Alternaria solani
Alternaria solani is a fungal plant pathogen that causes early blight of tomato, potato, and other solanaceous crops, producing bullseye leaf spots and significant yield losses.
Alternate history
Alternate history, also called alternative history or uchronia, is a speculative fiction genre imagining outcomes of changed historical events; first novel Geoffroy 1836, entered SF with Leinster's 1934 "Sidewise in Time".
Alternate reality game
Alternate reality game (ARG): interactive networked narrative using the real world as platform and transmedia storytelling; TINAG fiction, rabbit holes, puppetmasters; began with The Beast (2001), I Love Bees (2004), Perplex City (2005-2007).
Alternating current
Alternating current (AC) is electricity that periodically reverses direction, the standard form delivered by power lines at 60 Hz in the US and 50 Hz in Europe.
Alternating direction method of multipliers
The alternating direction method of multipliers (ADMM) is an algorithm for convex optimization that splits large problems into smaller subproblems, with applications to the lasso, basis pursuit, and support vector machines.
Alternating Gradient Synchrotron
The Alternating Gradient Synchrotron (AGS) is a 33 GeV proton synchrotron at Brookhaven National Laboratory in New York, operating since 1960 and linked to three Nobel Prizes in Physics.
Alternating group
The alternating group A_n is the group of even permutations of n objects, of order n!/2, and is simple, with no proper nontrivial normal subgroups, for every n at least 5.
Alternating hemiplegia of childhood
Alternating hemiplegia of childhood (AHC), an ultra-rare ATP1A3-related neurodevelopmental disorder, causes infantile-onset alternating hemiplegic episodes, dystonia, nystagmus, and dysautonomia that remit with sleep; flunarizine is the main treatment.
Alternating least squares
Alternating least squares (ALS) is an iterative optimization algorithm for matrix factorization used in recommender systems, solving for one factor matrix while holding the other fixed.
Alternating optimization
Alternating optimization is a numerical method that minimizes a multivariable function by optimizing blocks of parameters in turn, underpinning the EM algorithm and alternating least squares.
Alternating projections method
The alternating projections method is an iterative technique that solves constraint problems by projecting an estimate onto constraint sets in turn, underpinning phase retrieval algorithms like Gerchberg-Saxton.
Alternating skew deviation
Alternating skew deviation is a supranuclear vertical eye misalignment that reverses with gaze direction, affecting about 12% of skew deviation patients, usually from pretectal, cerebellar, or cervicomedullary lesions.
Alternating-time temporal logic
Alternating-time temporal logic (ATL) is a modal temporal logic stating what groups of agents can enforce by strategy, introduced by Alur, Henzinger, and Kupferman and published in full in 2002.
Alternation of generations
Alternation of generations: the land plant life cycle alternating a multicellular haploid gametophyte with a diploid sporophyte; gametophyte-dominant in bryophytes, sporophyte-dominant in vascular plants, origin by delayed meiosis (Bower).
Alternation of generations in bryophytes
Alternation of generations in bryophytes is a life cycle in which the haploid gametophyte produces eggs and sperm, and the diploid sporophyte produces spores, each generation giving rise to the other.
Alternative (album)
Alternative (album): Pet Shop Boys B-sides compilation, released 7 August 1995 on Parlophone; 30 tracks from "In the night" to "Some speculation"; UK number 2; followed by Format (2012).
Alternative (political bloc)
The Alternative Bloc, or Alternative Electoral Bloc, is a Moldovan political alliance formed in January 2025. It won 8 of 101 parliamentary seats in the 2025 election.
Alternative algebra
Alternative algebra, also known as alternative ring, is an algebra in which every two elements generate an associative subalgebra; the octonions are the standard non-associative example.