All articles starting with P
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Plataean Tumulus (Marathon)
Plataean Tumulus (Marathon): burial mound near the Marathon museum, Vranas, Attica, excavated by Spyridon Marinatos in 1970 and tentatively identified as the grave of Plataean soldiers who fell at the Battle of Marathon in 490 BC; identification doubted by Koumanoudis.
Platalea
Platalea, the spoonbills, is a genus of six wading-bird species in Threskiornithidae: Eurasian, Black-faced, Royal, African, Yellow-billed, and Roseate Spoonbills, tactile feeders with spoon-shaped, remote-touch bills.
Platalea leucorodia
Platalea leucorodia, the Eurasian spoonbill (Spatola, Lepelaar), a large white colonial wader of Threskiornithidae breeding from western Europe to East Asia; Least Concern, three subspecies, tactile bill-sweeping feeder.
Platanaceae
Platanaceae, the plane-tree family (Platanus, sycamores), a monogeneric Proteales family of 10 deciduous tree species with peeling bark, globular flower heads, and 2n = 42, native mainly to temperate North America.
Platanar
Platanar (Volcán Congo) is a dormant Pleistocene stratovolcano in Costa Rica's Cordillera Central, part of the 900 km² Platanar-Porvenir complex within Chocosuela caldera, 2,267 m, no Holocene eruptions, hit by 2023 landslides.
Platanista
Platanista, South Asian river dolphins: Ganges river dolphin (Platanista gangetica) and Indus river dolphin (P. minor), raised to separate species in 2021; sole living relicts of Platanistoidea, Endangered, effectively blind, echolocating freshwater cetaceans.
Platanista grove
Platanistas (Πλατανιστάς), the plane-tree grove at Sparta: an island-like fighting ground ringed by a canal and bridges where Spartan ephebes fought ritual combats after puppy and boar sacrifices, with cults of Helen, Enyalios, and Cynisca.
Platanthera
Platanthera (bog orchid, fringed orchid) is a large Northern Hemisphere genus of terrestrial orchids, about 155–200 species across Eurasia, North Africa, Macaronesia, and the Americas, moth-pollinated, hybridization-prone, with several threatened species.
Platanus
Platanus (plane trees, sycamores) is the sole genus of Platanaceae, order Proteales, with 10 accepted species native from SE Europe to Indochina and E Canada to Guatemala; includes the London plane hybrid and faces canker stain disease.
Platanus × acerifolia
Platanus × acerifolia, the London plane (syn. P. × hispanica), is a 17th-century hybrid of Oriental plane and American sycamore, a pollution-tolerant street tree up to 35 m with flaking mottled bark and paired fruit balls.
Platanus occidentalis
Platanus occidentalis, American sycamore or buttonwood, a large deciduous tree of eastern North American bottomlands, parent of the London plane hybrid, with white exfoliating bark, singly borne fruit-balls, and no major IUCN threats.
Platanus orientalis
Platanus orientalis, the oriental plane, is a large deciduous tree native from southeast Europe to northern Iran, grown for millennia as a shade tree and parent of the London plane.
Plate armour
Plate armor, also known as plate mail or a suit of armor, is body armor of shaped metal plates worn by European knights, developed into the full harness by about 1450.
Plate count (microbiology)
The plate count is a microbiological method that estimates viable microorganisms by culturing diluted samples on agar plates and counting colonies, reported as colony-forming units (CFU).
Plate fixation
Plate fixation is a surgical technique for treating fractures that uses a metal plate and screws to provide absolute or relative stability for bone healing.
Plate girder bridge
A plate girder bridge is a steel bridge supported by built-up I-shaped girders made from welded or riveted plates, widely used for spans of roughly 30 to 100 m.
Plate glass university
Plate glass universities are UK universities founded in the 1960s, especially East Anglia, Essex, Kent, Lancaster, Sussex, Warwick, and York, named for their glass-heavy modern architecture and driven by the UGC and the 1963 Robbins Report.
Plate heat exchanger
A plate heat exchanger transfers heat between two fluids through a stack of corrugated metal plates without mixing, offering high efficiency and a small footprint.
Plate tectonics
Plate tectonics is the scientific theory that Earth's lithosphere is broken into moving plates whose interactions explain most earthquakes, volcanoes, and mountain building; it was widely accepted after 1968.
Plateau
Plateau: a large flat elevated landform rising sharply on at least one side, covering about a third of Earth's land. Formed by tectonic uplift, lava flows, or erosion; erodes into mesas and buttes. Largest is the Tibetan Plateau.
Plateau du Tademaït
Plateau du Tademaït (Tademait), a hamada plateau near 28.5N 2.25E in central Algeria's Sahara, about 600 m high, built of Upper Cretaceous carbonates, with Lower Paleolithic sites and the Krechba gas field.
Plateau iris syndrome
Plateau iris syndrome (PIS): angle closure persisting after patent laser iridotomy, caused by an anteriorly positioned ciliary body pushing the iris root into the trabecular meshwork; distinct from plateau iris configuration, treated with iridoplasty.
Plateau State
Plateau State, north-central Nigeria, capital Jos, created 3 February 1976 from Benue-Plateau State. Known for the Jos Plateau (average 1,200 m), cool climate, 17 LGAs, tin and columbite mining, agriculture, and recurring farmer-herder conflict.
Plateau-Central Region
Plateau-Central Region (région du Plateau Central): administrative region of central Burkina Faso, capital Ziniaré, created 2 July 2001; three provinces (Oubritenga, Ganzourgou, Kourwéogo), 8,453 km², over 100 reservoirs including the Ziga dam.
Plated through-hole
A plated through-hole is a hole drilled through a printed circuit board whose copper-lined wall conducts electricity between the board's layers and can hold a component lead.
Platelet
Platelet (thrombocyte): anucleate 2–4 µm blood cell fragment from megakaryocytes, 150–450 × 10⁹/L, 7–10 day lifespan, ~10¹¹ made daily; drives primary hemostasis and arterial thrombosis, transfused for thrombocytopenia.
Platelet Activation
Platelet activation: the process by which stimulated blood platelets change shape, release granule contents (ADP, TXA2), and activate integrin αIIbβ3 to aggregate, driving hemostasis, thrombosis, and inflammation.
Platelet Aggregation (Plug Formation)
Platelet aggregation (plug formation), Reactome pathway R-HSA-76009, is the interplatelet bonding step of hemostasis in which activated integrin αIIbβ3 (GPIIb/IIIa) binds fibrinogen and vWF to bridge platelets into the hemostatic plug.
Platelet aggregometry
Platelet aggregometry is a family of laboratory tests that measures platelet clumping in blood samples, usually after adding an agonist such as ADP or collagen, to diagnose platelet function disorders.
Platelet Count
Platelet count: number of platelets per microliter of blood, part of the CBC. Normal adult range 150,000-400,000/µL; low counts (thrombocytopenia) raise bleeding risk; EDTA clumping causes pseudothrombocytopenia.