All articles starting with D
24,034 articles
Default mode network
Default mode network (DMN), also called default network, a brain network of medial prefrontal, posterior cingulate, precuneus, angular gyrus, and temporal regions active at rest and during internal thought, suppressed during attention-demanding tasks; named by Raichle et al. 2001.
DEFB1
DEFB1 (HBD-1, BD1) is the human chromosome 8p23.1 gene encoding beta-defensin 1, a constitutively expressed, salt-sensitive epithelial antimicrobial peptide linked to cystic fibrosis, urinary tract defense, and polymorphism-associated caries and periodontitis risk.
DEFB103A
DEFB103A, also known as DEFB103, is a human gene on chromosome 8 that encodes beta-defensin 3 (hBD-3), an inducible antimicrobial peptide active against bacteria and Candida.
DEFB4A
DEFB4A (defensin beta 4A, formerly DEFB2/DEFB4) is a human protein-coding gene at 8p23.1 encoding human beta-defensin 2 (HBD-2, SAP1), an inflammation-inducible, salt-sensitive antimicrobial peptide; closest paralog DEFB4B; linked to psoriasis copy number and UC biomarker studies.
DEFCON
DEFCON (defense readiness condition) is the US military's five-level alert system, DEFCON 5 peacetime to DEFCON 1 maximum readiness, established by the Joint Chiefs of Staff in 1959, with exercise names Fade Out through Cocked Pistol; its current level is classified.
DEFCON (video game)
DEFCON (DEFCON: Global Thermonuclear War) is a 2006 real-time strategy game by Introversion Software, inspired by WarGames, in which up to six players wage nuclear war on a vector world map; Metacritic 84.
Defeat and death of al-Mustarshid
The defeat and death of al-Mustarshid (قتل المسترشد بالله) was the 1135 capture of the Abbasid caliph al-Mustarshid by Seljuk sultan Mas'ud and his murder in captivity.
Defeat and death of Mago in Sicily
The defeat and death of Mago in Sicily was the killing of the Carthaginian commander Mago by Dionysius I of Syracuse at the Battle of Cabala, in the 380s or 370s BC.
Defeat of Li Ling
The Defeat of Li Ling (李陵之败) was the destruction of Li Ling's 5,000 Han infantry by Xiongnu cavalry in 99 BC, after which Ling surrendered.
Defecation
Defecation is the expulsion of feces through the anus, coordinated by the enteric, spinal, and central nervous systems, the pelvic floor, and the anal sphincters; most people defecate 1 to 3 times daily.
Defecography
Defecography (evacuation proctography) is real-time fluoroscopic or MRI imaging of defecation to assess pelvic floor disorders such as rectocele, enterocele, intussusception, and dyssynergia.
Defect chemistry
Defect chemistry is the branch of solid-state chemistry that treats imperfections in crystals, such as vacancies, as chemical species whose equilibria govern conductivity, catalysis, and color in functional materials.
Defect density
Defect density is a software quality metric defined as the number of defects divided by software size, usually reported as defects per thousand lines of code (KLOC).
Defect engineering
Defect engineering is the deliberate creation and control of imperfections in a material's crystal lattice so the defects serve useful functions, especially in two-dimensional materials like graphene.
Defect engineering in metal–organic frameworks
Defect engineering in metal–organic frameworks (MOFs) is the intentional control of structural defects, such as missing linkers or missing metal clusters, to tailor adsorption, catalytic, and mechanical properties.
Defect tolerance
Defect tolerance is a concept in semiconductor physics describing materials that stay efficient despite high defect densities, best known in lead-halide perovskites, which made low-cost solution-processed solar cells possible.
Defect triage
Defect triage is the software process of reviewing, classifying, prioritizing, and routing reported bugs, deciding for each whether it will be fixed, deferred, or rejected.
Defect-tolerant perovskite hypothesis
The defect-tolerant perovskite hypothesis holds that lead-halide perovskite semiconductors keep long carrier lifetimes despite many crystallographic defects, since their defects form shallow rather than deep traps.
Defected Malta
Defected Malta is a house-music festival held each October in Malta, launched in 2022 by Defected Records as an island counterpart to its Defected Croatia festival, selling out over 5,500 tickets by 2025.
Defection
Defection is the act of giving up allegiance to one state or political side for another, usually over disagreement with government policy, often through immigration or asylum.
Defection of Capua
The defection of Capua was Capua's decision to break its alliance with Rome and join Hannibal after Cannae in 216 BC; Rome recaptured the city in 211 BC and punished it severely.
Defection of Gyeon Hwon to Goryeo
The defection of Gyeon Hwon to Goryeo (견훤의 귀부) was the 935 flight of Later Baekje's deposed king to Wang Geon, which led to Later Baekje's fall in 936.
Defection of Yelü Chucai to the Mongols
The Defection of Yelü Chucai to the Mongols (耶律楚材归附蒙古) was the 1218 submission of the Jin dynasty Khitan scholar-official Yelü Chucai to Chinggis Khan, who made him Utu Saghal.
Defective democracy
Defective democracy: political science concept by Wolfgang Merkel and Aurel Croissant for electoral democracies lacking full liberal constitutional standards, with subtypes exclusive, illiberal, delegative, and tutelary democracy.
Defective pixel
A defective pixel, also called a dead pixel, is a pixel in an electronic display that does not work correctly, such as one stuck bright or dark.
Defective Viruses
Defective viruses lack a complete genome and cannot fully replicate or form a protein coat without a helper virus. Includes defective interfering particles (DIPs/DVGs), first seen by von Magnus in 1940s influenza, and satellite viruses; they interfere with replication, stimulate immunity, and drive persistence.
Defects of O-glycan initiation and core extension
Defects of O-glycan initiation and core extension are inborn errors of metabolism in which the first sugars attached to a protein's serine or threonine residues cannot be built correctly.
Defects per million opportunities
Defects per million opportunities (DPMO) is a Six Sigma measure: defects divided by opportunities for defects, multiplied by one million, standardized at Motorola in 1986.
Defence against restriction A, N-terminal
Defence against restriction A, N-terminal: N-terminal region of DarA, a bacteriophage P1 virion protein packaged in the head and coinjected with DNA to protect it from host type I restriction systems, acting strictly in cis.
Defence Day
Defence Day (Youm-e-Difa), 6 September, is Pakistan's annual observance of the 1965 war, marking the Indian crossing of the international border toward Lahore and Kasur; now observed as Defence and Martyrs Day with change-of-guard and gun-salute ceremonies.