72,234 articles
Natural farming
Natural farming is an ecological crop production method avoiding tillage, synthetic fertilizers, and pesticides, developed by Masanobu Fukuoka and extended in India as Zero Budget Natural Farming.
Natural forest
Natural forest: forest of indigenous trees regenerated naturally, not planted, per FAO/FRA definitions; ranges from primary (undisturbed) forest to used stands; distinct from plantations.
Natural hazard
A natural hazard is a naturally occurring process or event, such as an earthquake, flood, or tropical cyclone, that can cause deaths, injuries, property damage, or economic disruption.
Natural history
Natural history: the observational study of nature, past and present, by naturalists who observe, collect, and classify organisms and specimens; roots in Aristotle and Renaissance science, basis of ecology, conservation, and natural history museums.
Natural history and clinical course of Duchenne muscular dystrophy
The natural history of Duchenne muscular dystrophy runs from symptoms at ages 2 to 3, loss of walking by 8 to 12 untreated, and death in the twenties.
Natural history study
A natural history study is a preplanned observational study that tracks a disease's course over time without assigning an intervention, informing rare-disease drug development and external controls.
Natural killer cell
Natural killer (NK) cells are innate cytotoxic lymphocytes of the ILC family that kill virus-infected and tumor cells via missing-self recognition, perforin-granzyme lysis, and ADCC, and show adaptive features like CMV-driven clonal expansion.
Natural orifice specimen extraction surgery
Natural orifice specimen extraction surgery (NOSES) is a minimally invasive technique that removes resected tissue through the anus, vagina, or mouth, avoiding an abdominal incision.
Natural orifice transluminal endoscopic surgery
Natural orifice transluminal endoscopic surgery (NOTES) is a minimally invasive technique operating on abdominal or thoracic organs through the mouth, anus, vagina, or bladder, with no abdominal-wall incision.
Natural product
Natural product: secondary metabolite from plants, microbes, or marine animals, excluding primary metabolism and macromolecules. Over 23,000 characterized; ~49% of 1981–2002 small-molecule drugs trace to natural products, with genome mining driving revival.
Natural product research
Natural product research studies chemicals made by living organisms: isolation, structure elucidation, synthesis, biosynthesis, and bioactivity. Key journals include Natural Product Research (formerly Natural Product Letters), Journal of Natural Products, and Natural Product Reports.
Natural regeneration
Natural regeneration is the renewal of a forest from self-sown seed, coppice shoots, or root suckers rather than planting, and is usually far cheaper than plantations.
Natural reservoir
Natural reservoir: the animal, human, or environmental population or system in which a pathogen is permanently maintained and from which it spreads to humans or livestock; defined by Haydon et al. (2002), confirmed by ring-fencing, exemplified by bat reservoirs of Marburg, Nipah, and rabies.
Natural resource management
Natural resource management (NRM) applies scientific and technical principles to managing land, water, soil, plants, and animals, balancing ecological, economic, and social goals across forests, fisheries, and farmland.
Natural selection
Natural selection: differential reproductive success of individuals with heritable trait differences, the only directed mechanism of evolution producing adaptation. Co-published by Darwin and Wallace in 1858; contrasted with drift, mutation, and gene flow.
Natural T-regulatory cell
Natural T-regulatory cell (nTreg, now tTreg): a thymus-derived CD4+ FoxP3+ CD25+ CTLA-4+ regulatory T cell mediating self-tolerance; distinguished from peripherally induced iTreg cells; 2025 Nobel-recognized.
Nature Biotechnology
Nature Biotechnology (Nat. Biotechnol., ISSN 1087-0156) is Springer Nature's monthly peer-reviewed journal covering the science and business of biotechnology; founded as Bio/Technology in 1983, renamed 1996, 2025 impact factor 44.5.
Nature conservation
Nature conservation is the practice of protecting, managing, and restoring the living world; its central tool is the protected area, with over 200,000 covering about 15% of land by 2016.
Nature protection
Nature protection: laws, policies, and protected areas conserving species and habitats. Covers legal mechanisms, the 30x30 Kunming-Montreal target, protected area effectiveness, the EU Nature Restoration Regulation, and IUCN and TNC history.
Nature Reviews Cardiology
Nature Reviews Cardiology (Nat. Rev. Cardiol.), ISSN 1759-5002/1759-5010, is a Springer Nature monthly review journal launched in 2004 as Nature Clinical Practice Cardiovascular Medicine, publishing commissioned, peer-reviewed non-primary cardiology content with a 2025 impact factor of 50.2.
Nature versus nurture
Nature versus nurture: the debate over genetic versus environmental causes of trait variation, framed by Galton's 1875 twin studies, quantified through heritability, and reframed as gene-environment interaction.
Naturopathy
Naturopathy, also called naturopathic medicine, is a medical system from traditional practices and 19th-century European health approaches that aims to treat disease by addressing root causes through diet, exercise, and stress management.
Nauclea
Nauclea is a genus of Rubiaceae trees native to tropical Africa, Asia, and northern Australia, used in traditional medicine against malaria and pain and for timber; key species include N. latifolia, N. officinalis, and threatened N. diderrichii.
Naucoridae
Naucoridae, commonly called creeping water bugs or saucer bugs, is a family of oval, flattened predatory aquatic true bugs that crawl among submerged vegetation in freshwaters worldwide.
Naucrates ductor
Naucrates ductor, the pilotfish (pez piloto, poisson pilote), a circumtropical carangid fish that accompanies sharks, rays, turtles, and ships, feeding on scraps, parasites, and excrement; IUCN Least Concern.
Nausea
Nausea, also called emesis-related queasiness, is the unpleasant sensation that vomiting is imminent. It affects over 50% of adults yearly, is three times more common in women, and becomes chronic when persisting over 4 weeks.
Nausea or vomiting
Nausea or vomiting (ICD-11 MD90): nausea is the urge to vomit, vomiting the forceful expulsion of gastric contents. Common symptoms with central and peripheral mechanisms, caused by gastroenteritis, drugs, pregnancy, and many other conditions.
Nautilida
Nautilida is an order of coiled nautiloid cephalopods including the living chambered nautiluses and their fossil relatives, which range from the early Devonian to the present day.
Nautiloid
Nautiloids, a group within Nautiloidea, are characterized by an external, chambered shell divided by septa and a siphuncle, appearing in the Upper Cambrian.
Nautiloid fossil record by region
The regional distribution of nautiloid and other non-ammonoid fossil cephalopods, surveyed continent by continent, explaining why Ordovician records cluster in the tropics of the ancient Southern Hemisphere.