All articles starting with U
6,146 articles
Upper Mackenzie
Upper Mackenzie (FEOW ecoregion 104) is a Canadian freshwater ecoregion of temperate floodplain rivers and wetlands covering the upper Mackenzie watershed across Alberta, British Columbia, Saskatchewan, and the NWT, defined by the Peace, Slave, Athabasca, and Hay rivers and the Peace-Athabasca Delta.
Upper mantle
The upper mantle is the outermost part of Earth's mantle, extending from the Moho down to the 660-km discontinuity and hosting the lithosphere and asthenosphere that carry tectonic plates.
Upper Middle Bogan
Upper Middle Bogan is an Australian sitcom created by Robyn Butler and Wayne Hope, aired on ABC1 2013-2016 in three 8-episode seasons. Doctor Bess Denyar discovers her birth family runs a drag-racing team; AACTA 2016 Best Comedy winner.
Upper middle class
Upper middle class: the higher-status segment of the middle class, marked by graduate education, professional occupations like law and medicine, household incomes commonly above $100,000, and top-quintile earnings; distinct from lower middle class and upper class.
Upper Middle Rhine Valley
Upper Middle Rhine Valley (Oberes Mittelrheintal), 65 km UNESCO World Heritage cultural landscape between Bingen/Rüdesheim and Koblenz, Germany, inscribed 2002 under criteria ii, iv, v; 60 towns, about 40 castles, terraced vineyards.
Upper Mississippi
Upper Mississippi: river reach from Lake Itasca, Minnesota, to the Ohio River confluence at Cairo, Illinois; with the Illinois River it forms the 1,300-mile UMRS, a 1986-designated national ecosystem and 9-foot-channel navigation system.
Upper Mississippi River 9-foot channel project
The Upper Mississippi River 9-foot channel project is a U.S. Army Corps of Engineers program, authorized in 1930, creating locks and dams for a 9-foot navigation channel.
Upper Mississippi River Floodplain Wetlands
Upper Mississippi River Floodplain Wetlands, Ramsar site 1901, a Wetland of International Importance in Minnesota, Iowa, Wisconsin, and Illinois, centered on the 261-mile, 240,000-acre Upper Mississippi River National Wildlife and Fish Refuge and its backwater lakes, floodplain forests, and marshes.
Upper Missouri
The Upper Missouri refers to the upper portion of the Missouri River and its basin, spanning Montana, Wyoming, the Dakotas, and Nebraska down to the Missouri–Platte confluence near Omaha.
Upper Mortlock Islands - Nema Island
Nema Island, also called Nama, is a coral island and municipality in Chuuk State, Federated States of Micronesia, forming the northernmost unit of the Mortlock Islands.
Upper motor neuron
Upper motor neuron: cortical and brainstem neurons of the pyramidal (corticospinal and corticobulbar) tracts that synapse on lower motor neurons; lesions cause spasticity, hyperreflexia, clonus, and a positive Babinski sign.
Upper motor neuron lesion
Upper motor neuron lesion: damage to CNS motor neurons or the corticospinal/corticobulbar tracts above the anterior horn, causing weakness, spasticity, hyperreflexia, clonus, and the Babinski sign, distinct from lower motor neuron lesions.
Upper Navua Conservation Area
The Upper Navua Conservation Area (UNCA) is a 615-hectare protected river gorge in Serua Province, Fiji, created in 2000 and designated in 2006 as Fiji's first Ramsar site.
Upper Niger
Upper Niger: FEOW freshwater ecoregion 507, the upper Niger River basin above the Inner Niger Delta in Guinea and Mali, a tropical upland-river ecoregion with the Bani tributary and cichlid Gobiocichla wonderi.
Upper Nile (district)
Upper Nile State, a state of northeastern South Sudan bordering Sudan, capital Malakal, 12 counties, 77,004 km2, about 1.86 million people in 2025, heavy displacement and returns, and conflict since March 2025.
Upper Nile (protected area)
Upper Nile (KBA 6198) is a confirmed Key Biodiversity Area on ~190 km of the Nile between Luxor and Kom Ombo, Egypt, a riverine wetland holding Egypt's largest wintering waterbird concentrations, threatened by pollution, disturbance, and bank engineering.
Upper Normandy Region
Upper Normandy (Haute-Normandie), former French region 1956-2016 of Eure and Seine-Maritime, capital Rouen, industrial Seine-corridor region; merged with Lower Normandy into Normandy on 1 January 2016.
Upper Nubia
Upper Nubia is the stretch of the Nile valley in northern Sudan from the Third to the Sixth Cataract, the heartland of Kerma, Napata, and the Meroitic civilization.
Upper Palatinate
The Upper Palatinate is one of Bavaria's seven administrative districts in Germany, with its seat at Regensburg. It borders the Czech Republic, has about 1.1 million inhabitants, and belongs to Bavaria since 1628.
Upper Paleolithic
Upper Paleolithic: later Old Stone Age division, roughly 50,000-30,000 years BP, marked by blade technologies, bone tools, ornaments, and the dispersal of Homo sapiens across Eurasia, including the Initial Upper Paleolithic, replacing Neanderthals.
Upper Parana
Upper Parana, or Upper Paraná, is a freshwater ecoregion covering the Rio Paraná basin above the former Guaíra Falls, mostly in Brazil and known for 131 endemic fish species.
Upper Peninsula of Michigan
Michigan's Upper Peninsula (U.P.), the northern peninsula bordered by Lake Superior, Wisconsin, and Lakes Michigan and Huron; home of Yooper identity, Keweenaw copper and iron mining history, 917 miles of Lake Superior shoreline, and Michigan's entire wolf population.
Upper respiratory tract infection
Upper respiratory tract infection (URI, URTI): viral infection of the nose, sinuses, throat, and larynx; includes the common cold, sinusitis, tonsillitis, and laryngitis, caused by over 200 viruses, mainly rhinoviruses, and treated supportively.
Upper Rio Grande - Bravo
Upper Rio Grande - Bravo, FEOW freshwater ecoregion 132 (Río Bravo del Norte), covers Rio Grande watersheds from Colorado headwaters to the Río Conchos mouth; temperate upland rivers, C-grade health, 52% unsustainable water use.
Upper Salween
Upper Salween: FEOW freshwater ecoregion 721, Palearctic, tropical and subtropical upland rivers, covering the Salween (Nu) basin in China north of the Nanding River confluence, with 8 endemic fish species.
Upper Saskatchewan
Upper Saskatchewan (FEOW ecoregion 107) is a temperate upland rivers ecoregion covering the Saskatchewan River headwaters from the Canadian Rockies across southern Alberta and western Saskatchewan, with 41 fish species and endangered conservation status.
Upper Savoy
Upper Savoy (Haute-Savoie, dept. 74), a French department in Auvergne-Rhône-Alpes bordering Switzerland and Italy; prefecture Annecy; 861,158 inhabitants in 2023, strong growth, Geneva cross-border work, bar turning industry, and Alpine tourism.
Upper Scorpius association
The Upper Scorpius association (USco or Upper Sco), the youngest subgroup of the Scorpius-Centaurus OB association, lies about 145 parsecs away in Scorpius, near the Scorpion's head.
Upper Silesia
Upper Silesia (Polish: Górny Śląsk; German: Oberschlesien) is the southeastern part of the historic region of Silesia, now divided between Poland and the Czech Republic and known for its coal industry around Katowice.
Upper Silesian Coal Basin
The Upper Silesian Coal Basin, or USCB, is a large Carboniferous hard coal basin in southern Poland extending into the Czech Republic, one of Europe's most significant coal-producing regions.