All articles starting with R
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Rarámuri
Rarámuri (Ralámuli, Tarahumara): indigenous people of the Sierra Tarahumara, Chihuahua, Mexico, about 120,000 strong, known for long-distance running, Jesuit-era cargo government, and recent land restitutions.
Rarámuri oral literature
Rarámuri oral literature is the spoken narrative, song, and ritual speech of the Rarámuri (Ralámuli) people of the Sierra Tarahumara in Chihuahua, Mexico, transmitted in the Rarámuri language.
Rarandoi Veduka Chudham
Rarandoi Veduka Chudham (రారండోయ్ వేడుక చూద్దాం), also spelled Rarandoi Veduka Chuddam, is a 2017 Telugu romantic family drama directed by Kalyan Krishna Kurasala, produced by Nagarjuna under Annapurna Studios, starring Naga Chaitanya and Rakul Preet Singh, music by Devi Sri Prasad.
RARB
RARB (retinoic acid receptor beta, NR1B2) is a human gene at 3p24.2 encoding a nuclear retinoic acid receptor, a tumor suppressor lost in many cancers, with five isoforms and variants causing syndromic microphthalmia 12.
RARBG
RARBG was a major BitTorrent index and release hub founded in 2008, known for high-quality movie and TV torrents; it shut down voluntarily on May 31, 2023, citing COVID, the Ukraine war, and rising costs.
Rare (company)
Rare (Rare Limited) is a British video game studio founded in 1985 by the Stamper brothers, famed for Donkey Kong Country, GoldenEye 007, and Banjo-Kazooie; Nintendo held a 1990s stake before Microsoft bought it for $375 million in 2002, and in 2026 it was moved under Activision.
Rare (Selena Gomez album)
Rare (2020) is the third solo studio album by Selena Gomez, released January 10, 2020 on Interscope, 13 songs in 41 minutes. Follows 2015's Revival; lead single "Lose You to Love Me" was her first Billboard Hot 100 No. 1.
Rare and endangered plant areas
Rare and endangered plant areas: dedicated ex situ sections in botanic gardens, such as China's National Botanical Garden 1.5 ha area with 70+ species, growing and documenting threatened plants for conservation, research, and reintroduction.
Rare and threatened bryophytes of the British Isles
The rare and threatened bryophytes of the British Isles are mosses, liverworts, and hornworts assessed on British and Irish red lists, with 191 British species threatened in 2023.
Rare Breeds Survival Trust
Rare Breeds Survival Trust (RBST), UK charity founded 1973 conserving native farm livestock and equine breeds; publishes the annual Watchlist (Ne and inbreeding methodology) and runs the UK National Livestock Gene Bank; no native breed extinct since 1973.
Rare disease
Rare disease: condition affecting few people; defined as under 1/2,000 prevalence in Europe, under 200,000 US patients, under 1/10,000 in Japan and China; over 7,000 diseases, 300 million people, treated via incentivized orphan drugs.
Rare Earth (band)
Rare Earth is a Detroit rock band formed in 1960 as the Sunliners, the white act on Motown with hits "Get Ready" (#4, 1970) and "I Just Want to Celebrate" (#7, 1971); Motown named its Rare Earth Records subsidiary after the band, which still tours.
Rare Earth hypothesis
The Rare Earth hypothesis, or Rare Earth theory, argues that complex extraterrestrial life is likely rare even if microbial life is common across the universe.
Rare event sampling
Rare event sampling is a family of Monte Carlo techniques, chiefly importance sampling and splitting, that estimate very low-probability events far more efficiently than naive simulation.
Rare event simulation
Rare event simulation is a class of Monte Carlo methods, including importance sampling and splitting, that estimates very low-probability events far more efficiently than naive sampling.
Rare Objects (film)
Rare Objects (2023) is a drama directed, co-written, produced by, and co-starring Katie Holmes, adapting Kathleen Tessaro's novel; IFC Films released it April 14, 2023; it grossed $10,454 and scored 40% on Rotten Tomatoes.
Rare Replay
Rare Replay: 2015 Xbox One compilation of 30 Rare and Ultimate Play the Game classics, released for Rare's 30th anniversary at $29.99, with 10,000 gamerscore, Snapshot challenges, Rare Revealed extras, and GoldenEye 007 added digitally in 2023.
Rare species
Rare species: species at low abundance due to small range, narrow habitat specificity, or sparse populations; Rabinowitz's seven forms, IUCN Red List links, functional rarity, and conservation.
Rare-earth barium copper oxide
Rare-earth barium copper oxide (REBCO) is a family of high-temperature superconductors with a critical temperature of about 92 K, dominant in coated conductor tape used for compact fusion tokamak magnets.
Rare-earth element
The rare-earth elements, or rare earths, are a group of 17 chemically similar metals: the 15 lanthanides plus scandium and yttrium, used in magnets, phosphors, and catalysts.
Rare-earth hydroxides
Rare-earth hydroxides are the hydroxide and oxyhydroxide solid phases of scandium, yttrium, and the lanthanides, whose solubility varies smoothly across the 4f series, enabling classical fractional precipitation separation of the rare earths.
Rare-earth ion
A rare-earth ion (REI) is a charged lanthanide, scandium, or yttrium ion embedded in a host crystal, whose shielded 4f electrons give narrow, stable optical transitions used in quantum memories.
Rare-earth ion qubits
Rare-earth ion qubits are quantum bits formed from the spin states of rare-earth ions doped into crystals, valued for the longest coherence times in a solid-state system.
Rare-earth magnet
A rare-earth magnet is a permanent magnet made from a lanthanide alloy, in two families: neodymium iron boron, the strongest commercial magnets, and samarium cobalt.
Rare-earth quantum memory
A rare-earth quantum memory is a device that stores quantum states of light in rare-earth ions doped into crystals, developed mainly as the storage element of quantum repeaters for future quantum networks.
Rare-earth-doped crystal quantum memory
A rare-earth-doped crystal quantum memory is a solid-state device that stores quantum states of light in rare-earth ions embedded in crystals, developed for quantum repeaters and networks.
Rare-earth-doped quantum memories
Rare-earth-doped quantum memories store photons in rare-earth ions doped into crystals such as YSO at cryogenic temperatures, retrieving the quantum state after a controlled time.
Rare-earth-free magnesium alloys
Rare-earth-free magnesium alloys are lightweight magnesium alloys that substitute inexpensive aluminum, zinc, and calcium for scarce rare earth metals, reaching yield strengths of 300 to 400 MPa.
Rarefaction (statistics)
Rarefaction is a statistical method that standardizes species richness by subsampling individuals or samples to a common count, introduced by Howard Sanders in 1968 for marine benthic ecology.
Rarefaction wave
A rarefaction wave, also called an expansion wave, is a disturbance in a compressible fluid across which pressure and density decrease, the smooth counterpart of a shock wave.