All articles starting with R
22,461 articles
Rhodobacteraceae
Rhodobacteraceae, also called the Roseobacter clade and now Paracoccaceae under LPSN, is an alphaproteobacterial family of over 100 genera; marine roseobacters reach up to 30% of pelagic bacterial communities and drive sulfur and carbon cycling.
Rhodococcus
Rhodococcus (Zopf 1891), conserved genus of mycolic-acid-containing Nocardiaceae actinobacteria; aerobic, Gram-positive, high G+C; includes R. equi foal pathogen and biodegradation strains.
Rhodococcus equi
Rhodococcus equi (Corynebacterium equi), a Gram-positive facultative intracellular soil coccobacillus with a vapA virulence plasmid; causes bronchopneumonia in foals 1-5 months old and opportunistic infection in immunocompromised humans, treated with macrolide plus rifampin.
Rhododendron
Rhododendron, including azaleas, is a large Ericaceae genus of 850+ woody species native from the temperate Northern Hemisphere to tropical Asian mountains and NE Australia, with leathery leaves, showy bell-shaped flowers, and winged seeds.
Rhododendron ferrugineum
Rhododendron ferrugineum, the alpenrose or alpine rose, is a dwarf evergreen Ericaceae shrub of the European Alps and Pyrenees, the type species of Rhododendron, flowering rosy scarlet at 1,700–2,500 m on acid, non-limestone soils.
Rhododendron ponticum
Rhododendron ponticum, an evergreen Ericaceae shrub native to the Black Sea region and Iberia, introduced to Britain in 1763, now one of the most destructive invasive plants of the British Isles, forming dense thickets and hosting Phytophthora ramorum.
Rhodopis
Rhodopis, also called the Oasis Hummingbird genus (Colibrí del Atacama), is a monotypic hummingbird genus (Reichenbach 1854) holding only Rhodopis vesper, a 12 cm sexually dimorphic hummingbird of arid Pacific coasts from Peru to northern Chile, IUCN Least Concern.
Rhodopseudomonas
Rhodopseudomonas, the red Pseudomonas, is a genus of gram-negative, budding, phototrophic purple non-sulfur bacteria in Alphaproteobacteria; type species R. palustris, used in wastewater treatment and hydrogen production.
Rhodopsin
Rhodopsin: the rod-cell GPCR photoreceptor of scotopic vision, composed of opsin plus 11-cis-retinal; first GPCR crystal structure, Meta II activates transducin, mutations cause retinitis pigmentosa.
Rhodopsin phototrophy in hypersaline ecosystems
Rhodopsin phototrophy in hypersaline ecosystems is light capture by retinal-pumping microbes such as haloarchaea and Salinibacter, whose ion pumps rival or surpass photosynthesis in salt-saturated saltern brines.
Rhodospirillum
Rhodospirillum is a genus of gram-negative, spiral-shaped purple nonsulfur bacteria that move by polar flagella and live in aquatic environments; the type species is R. rubrum.
Rhodospirillum rubrum
Rhodospirillum rubrum (Spirillum rubrum) is an alphaproteobacterial purple non-sulfur bacterium with anoxygenic photosynthesis, metabolic switching, and model status for photophosphorylation and biohydrogen research.
Rhodotorula
Rhodotorula is a genus of red or pink pigmented basidiomycetous yeasts described in 1928, found in many environments and known for producing carotenoids and occasionally causing infections.
Rhoiteion (Turkey)
Rhoiteion (Ῥοίτειον, Rhoeteum), ancient Greek city in the northern Troad, Turkey, at Baba Kale near Erenköy-İntepe; founded by Astypalaian Dorians, ransomed 425/4 BC, annexed to Ilion 189 BC.
Rhokana Corporation
Rhokana Corporation was a copper mining and holding company, controlled by Anglo American, that operated the Nkana mine on Zambia's Copperbelt from the 1930s until its 1970 nationalization.
Rhombic dodecahedron
The rhombic dodecahedron is a convex polyhedron with 12 rhombic faces, 24 edges, and 14 vertices, first described by Johannes Kepler around 1600. It tiles three-dimensional space with no gaps.
Rhombic triacontahedron
The rhombic triacontahedron is a convex polyhedron with 30 golden rhombic faces and 32 vertices, the dual of the icosidodecahedron and one of the 13 Catalan solids, discovered by Kepler.
Rhombicosidodecahedron
The rhombicosidodecahedron, formally the small rhombicosidodecahedron, is an Archimedean solid with 62 faces: 20 triangles, 30 squares, and 12 regular pentagons, named by Johannes Kepler in 1619.
Rhombicuboctahedron
The rhombicuboctahedron, also called the small rhombicuboctahedron, is an Archimedean solid with 26 faces, 8 triangles and 18 squares, first drawn by Leonardo da Vinci in 1509.
Rhombohedral graphene
Rhombohedral graphene is multilayer graphene whose carbon layers stack in the ABC sequence rather than the AB stacking of ordinary graphite, hosting superconductivity and topological states.
Rhombohedral trilayer graphene
Rhombohedral trilayer graphene (r-TLG, also RTG) is a stack of three graphene sheets with an ABC stacking sequence whose flat electronic bands host superconductivity, ferromagnetism, and topological states.
Rhomboid major muscle
Rhomboid major (musculus rhomboideus major), upper back muscle from T2-T5 spinous processes to the medial scapular border; retracts and stabilizes the scapula, innervated by the dorsal scapular nerve (C4-C5).
Rhombomys
Rhombomys (great gerbil genus), Wagner 1841; sole species Rhombomys opimus, largest gerbil of Central Asian deserts; social burrower, plague reservoir, IUCN Least Concern.
Rhombus
A rhombus (plural rhombi), often called a diamond or lozenge, is a quadrilateral with four equal sides, and its diagonals bisect each other at right angles.
Rhön Biosphere Reserve
Rhön Biosphere Reserve (Biosphärenreservat Rhön), a UNESCO Man and Biosphere site designated 6 March 1991 across Bavaria, Hesse, and Thuringia in central Germany; tri-state model region with core, care, and development zones, recertified in 2025 for ten more years.
Rhona Bennett
Rhona Bennett (born 1976, Chicago), also "Miss R&B," is an American singer and actress: a 1991-1994 Mickey Mouse Club Mouseketeer, Nicole on The Jamie Foxx Show, Darkchild solo artist (Rhona, 2001), and En Vogue member since 2003 who recorded Soul Flower and Electric Café and founded Personal Power University in 2016.
Rhona Cameron
Rhona Cameron (born 1965) is a Scottish stand-up comedian, writer and actor, winner of Channel 4's 1992 comedy award, host of Gaytime TV, star of the sitcom Rhona, author of 1979, and Una Struan in The Chief.
Rhona Martin
Rhona Martin (Rhona Howie), born 1966, Scottish curler who skipped Great Britain to women's curling gold at Salt Lake City 2002 with the 'Stone of Destiny', first British Winter gold since 1984; later coached GB women to Sochi 2014 bronze.
Rhona Mitra
Rhona Mitra, born Rhona Natasha Mitra, is a British actress best known for modeling the live-action Lara Croft in Tomb Raider promotions and appearing in television roles.
Rhonda Byrne
Rhonda Byrne is an Australian television producer and author who created the 2006 film and book The Secret, which has sold over 34 million copies.