All articles starting with P
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Pseudospectral method
A pseudospectral method solves differential equations by representing the solution with global basis functions like Fourier modes or Chebyshev polynomials, enforcing the equation at collocation points, giving exponential accuracy for analytic solutions.
Pseudospectrum
A pseudospectrum is a family of sets in the complex plane attached to a matrix or operator, showing where the resolvent norm is large, which matters most for non-normal operators.
Pseudostratified columnar epithelium
Pseudostratified columnar epithelium, also called respiratory epithelium when ciliated, is a single-layer tissue whose staggered nuclei mimic stratification; it lines the airways and male reproductive tract and drives mucociliary clearance.
Pseudoterminal
A pseudoterminal, abbreviated pty, is a pair of virtual character devices, a master and a slave, letting programs like ssh and xterm behave as if a real terminal were attached.
Pseudotsuga
Pseudotsuga (douglas-firs), Pinaceae conifer genus, 1867 Carrière; four species, P. menziesii (Douglas-fir), macrocarpa, sinensis, japonica; native western North America and East Asia; distinctive protruding cone bracts.
Pseudounicornuate uterus
Pseudounicornuate uterus (Utérus pseudo-unicorne, ORPHA:180079, ICD-10 Q51.4): rare non-syndromic Müllerian malformation with a single-horned crescent uterus plus a rudimentary second horn, often with urinary tract anomalies.
Pseudouridine
Pseudouridine is a modified nucleoside in RNA in which uracil bonds to ribose through carbon instead of nitrogen, discovered in 1951 and now used, as N1-methylpseudouridine, in mRNA vaccines.
Pseudouridine synthase
Pseudouridine synthases (PUS enzymes) are enzymes that convert uridine residues in RNA to pseudouridine; humans encode 13 of them, and over half are implicated in disease.
Pseudovector
A pseudovector, also called an axial vector, is a quantity that transforms like a vector under rotations but, unlike ordinary polar vectors, keeps its sign under spatial inversion.
Pseudovirion-based neutralization assay
A pseudovirion-based neutralization assay (PVNA), or pseudovirus neutralization assay, measures how well antibodies or sera block a single round of viral entry using replication-defective reporter viruses, and is widely used for SARS-CoV-2 serology and vaccine evaluation.
Pseudowire
A pseudowire is a mechanism that emulates the essential attributes of a telecommunications service, such as T1, Frame Relay, ATM, or Ethernet, over a packet-switched network using IP or MPLS.
Pseudoxanthoma elasticum
Pseudoxanthoma elasticum (PXE, Grönblad-Strandberg syndrome): rare autosomal recessive ABCC6 disorder causing calcification of elastic fibers in skin, retina, and arteries; low pyrophosphate; no causal treatment yet.
Pseudoxanthoma elasticum-like papillary dermal elastolysis
PXE-PDE, PXE-like papillary dermal elastolysis, is a rare acquired elastolytic skin disorder with yellowish cobblestone papules on the neck of postmenopausal women, mimicking inherited pseudoxanthoma elasticum but lacking systemic involvement.
PSG College of Technology
PSG College of Technology (PSG Tech), Coimbatore, is a government-aided autonomous engineering college founded in 1951 by PSG & Sons' Charities Trust, affiliated to Anna University, known for industry-linked sandwich programs, PSG STEP, and the Dr. GRD Memorial Library.
PSG Equity
PSG Equity is a growth equity firm founded in 2014 and headquartered in Boston, investing in software and technology-enabled services companies across North America, Europe, and Israel.
Psg Europe
PSG Europe is the Europe-focused growth-equity strategy of PSG, a Boston-based investment firm, investing in growth-stage B2B software companies from its London headquarters since 2019.
PSG Group
PSG Group was a South African investment holding company founded in 1995 by Jannie Mouton and Chris Otto, which grew to roughly R250bn in assets before delisting from the JSE in 2022.
Psherenptah III
Psherenptah III, also spelled Pasherienptah III, was High Priest of Ptah at Memphis from 76 BC to 41 BC, serving Ptolemy XII and Cleopatra VII.
Psi (ψι) (Greek)
Psi (ψεῖ, ψι; Ψ, ψ) is the 23rd letter of the Greek alphabet, denoting /ps/ with numeral value 700; a Greek-added letter whose western-alphabet value was /kh/.
Psi Andromedae
Psi Andromedae (ψ Andromedae), also cataloged as 20 Andromedae, is a yellow supergiant star in Andromeda, about 1000 light years away and recorded as a multiple star system with six pairs.
Psi Cops
Psi Cops is a Canadian adult animated comedy about two incompetent paranormal investigators, created by and starring Bart Batchelor and Chris Nielsen, premiering in 2023 on Adult Swim.
Psi Factor
Psi Factor: Chronicles of the Paranormal is a Canadian sci-fi drama (1996-2000, 88 episodes) hosted by Dan Aykroyd, about OSIR investigators of paranormal cases; the term also names the unquantifiable unknown factor in anomalistics.
Psi Persei
Psi Persei (ψ Persei, HD 22192) is a Be star in the constellation Perseus, a hot B-type star with a circumstellar gas disk and the brightest radio-emitting Be star.
PSI Software
PSI Software SE is a Berlin-based German enterprise software company, founded in 1969, that builds process control systems for energy grids, industrial production, and logistics, with about 2,250 employees.
PSI-BLAST
PSI-BLAST (Position-Specific Iterated BLAST) is an iterative protein database search program introduced by Stephen Altschul in 1997, which builds a position-specific scoring matrix from homologs to detect distant similarities.
Psi-Ops: The Mindgate Conspiracy
Psi-Ops: The Mindgate Conspiracy (working title ESPionage) is Midway's 2004 PS2/Xbox third-person action game starring psychic agent Nick Scryer against the Movement, with six psi powers, Havok physics, Metacritic 84, and a 2026 PS4/PS5 re-release.
Psi4
Psi4 is a free, open-source electronic structure program for quantum chemistry that implements Hartree–Fock, density functional, and coupled-cluster methods, written as a hybrid of C++ and Python.
Psicosis
Psicosis, also known as Nicho el Millonario, is the ring name of Mexican wrestler Dionicio Castellanos Torres, famous for his masked, high-flying rivalry with Rey Mysterio.
Psidium
Psidium (guava genus), Myrtaceae, native Mexico to tropical America, 71-92 species including cultivated Psidium guajava and invasive strawberry guava Psidium cattleyanum, one of the world's 100 worst invasive organisms.
Psidium guajava
Psidium guajava, the common guava, is a Neotropical Myrtaceae fruit tree grown across the tropics; Brazilian Amazonia is its probable domestication origin, and its fruit is exceptionally rich in vitamin C (230–1,426 mg/100 g).