All articles starting with P
28,818 articles
Pronation
Pronation: inward/downward rotation of the forearm (palm down, via pronator teres and quadratus) or of the foot (arch flattening during gait); opposite of supination, relevant to running shoes and injury.
Pronation of the foot
Pronation of the foot: triplanar motion (dorsiflexion, abduction, eversion) at the subtalar joint; also called overpronation when excessive. Evidence links pronated posture mainly to medial tibial stress syndrome and patellofemoral pain, with small effects.
Pronator drift
Pronator drift is a bedside neurological examination maneuver in which pronation and downward drift of one outstretched arm indicate a contralateral upper motor neuron lesion.
Prone position
Prone position: lying face down, opposite of supine. Used surgically for posterior spine access and therapeutically in ARDS, where over 12 hours daily proning reduces mortality in severe cases.
Prone ventilation
Prone ventilation is a critical care technique in which ventilated patients with respiratory failure are turned face-down to improve oxygenation, reducing mortality in severe ARDS.
Pronephros
The pronephros is the first and most primitive of the three vertebrate kidney forms, followed by the mesonephros and metaneephros, serving as the functional kidney of fish and amphibian larvae.
Pronetalol
Pronetalol (pronethalol, nethalide, Alderlin) was the first clinically useful beta-blocker, developed by James Black at ICI, launched in 1963, and withdrawn after causing thymic tumors in mice; propranolol replaced it.
Prong (band)
Prong, New York metal band formed 1986 at CBGB, led by Tommy Victor. Known for Beg to Differ, Cleansing (1994, Snap Your Fingers Snap Your Neck), State of Emergency (2023), and self-titled album due November 6, 2026 on Napalm Records.
Pronghorn
Pronghorn (Antilocapra americana), also called pronghorn antelope, is the sole living Antilocapridae, a fast North American ungulate reaching 45-55 mph with annually shed, pronged horns, native to western plains and deserts.
Pronic number
A pronic number, also known as an oblong or heteromecic number, is a number that is the product of two consecutive integers; the sequence begins 0, 2, 6, 12, 20.
Pronoia system
The pronoia system (πρόνοια) was a Byzantine institution granting individuals state revenues or land, usually in return for military service, arising in the eleventh century.
Pronoun
Pronoun (German Pronomen, Fürwort): a word substituting for a noun or noun phrase whose meaning is recoverable from context. Covers the eight English subclasses, binding theory, cross-linguistic variation, and the Swedish gender-neutral pronoun hen.
Pronovias
Pronovias is a Barcelona-based bridal fashion group selling wedding dresses under seven brands, grown from a 1922 lace shop and once the world's largest bridal wear company.
Pronumone
Pronumone (EU ID 998) is a pesticide active substance classified as an attractant, with no CAS number, never approved in the EU; excluded from Directive 91/414/EEC Annex I by Commission Decision 2004/129/EC of 30 January 2004, with a default MRL of 0.01 mg/kg.
Pronunciation lexicon
A pronunciation lexicon maps words and short phrases to their pronunciations for speech recognition and text-to-speech engines; the best-known English one is the CMU Pronouncing Dictionary.
Proof (2005 film)
Proof is a 2005 American drama film directed by John Madden, adapted from David Auburn's Pulitzer Prize-winning play, starring Gwyneth Paltrow, Anthony Hopkins, and Jake Gyllenhaal.
Proof (rapper)
Proof (DeShaun Dupree Holton, 1973-2006), aka Derty Harry, was a Detroit rapper who founded D12 in 1996, mentored Eminem, hosted the Hip Hop Shop battles, and was shot dead on 8 Mile Road in 2006.
Proof calculus
A proof calculus is a formal system of axioms and inference rules whose derivations establish the theorems of a logic; main forms include Hilbert systems, natural deduction, and sequent calculus.
Proof complexity
Proof complexity is the study of the sizes of propositional proofs, asking whether every tautology has a short proof or some require exponential length; it began with Tseitin in 1966.
Proof net
A proof net is a graph-based representation of a proof in linear logic, introduced by Jean-Yves Girard in 1987 to eliminate trivial rule permutations of sequent calculus derivations.
Proof of concept
A proof of concept (POC), also called proof of principle, is a small realization of an idea built to demonstrate it is feasible, preceding prototype and pilot stages.
Proof of Life
Proof of Life is a 2000 American thriller directed by Taylor Hackford and written by Tony Gilroy, starring Meg Ryan and Russell Crowe in a kidnapping-for-ransom drama.
Proof of stake
Proof of stake (PoS) is a blockchain consensus mechanism in which validators lock up a stake that can be destroyed for dishonesty, used by Ethereum, Cardano, and Solana.
Proof of work
Proof of work (PoW) is a scheme requiring costly computation that others can verify cheaply, securing blockchains like Bitcoin and first proposed against email spam in 1992.
PROOF study
PROOF study (PROgnostic indicator OF cardiovascular and cerebrovascular events; NCT00759304): French prospective cohort of 1,011 people aged 65 in Saint-Étienne testing whether autonomic nervous system activity predicts cardiovascular events, AF, hypertension, and mortality.
Proof test
A proof test is an acceptance test that loads a structure or component above its expected service load to demonstrate structural integrity and screen out defective parts.
Proof that e is irrational
Proof that e is irrational: the demonstration, first given by Euler in the 1730s, that Euler's number e cannot be written as a ratio of two integers.
Proof that π is irrational
Proof that π is irrational, first given by Johann Heinrich Lambert in 1761, established that π cannot be written as a ratio of two integers.
Proof-theoretic semantics
Proof-theoretic semantics is an alternative to model-theoretic semantics that explains the meaning of logical constants in terms of the inference rules governing their behavior in proofs.
Proofing (baking technique)
Proofing (proving, final proof) is the final rise of shaped yeast dough before baking, distinct from bulk fermentation. Typical conditions: 28–30 °C, 75–85% RH, 30–90 minutes; readiness judged by the poke test, with under- and over-proofing symptoms.