• Prilep (North Macedonia)

    Prilep, town, North Macedonia, south of Skopje on the Titov Veles–Bitola railway line. Prilep was an important centre during the Middle Ages. St. Nikola’s Church (1299) has valuable frescoes. The Monastery of Archangel Michael and the Church of St. Dimitri both date from the 14th century, during

  • prill (pellet form)

    explosive: Ammonium nitrate–fuel oil mixtures: ANFO applications were based on prilled rather than crystallized ammonium nitrate. Prills, or free-flowing pellets, were developed for the fertilizer market, which requires a coarse product that has little tendency to set and can be spread easily and smoothly. A small amount of kieselguhr is generally added to improve the…

  • Priluki (Ukraine)

    Pryluky, city, northern Ukraine, on the Uday River. It is one of the oldest cities in Ukraine, being first documented in 1092. It was destroyed by the Mongols in the 13th century. In modern times it became a centre of the oil industry based on local deposits (those of the Dnieper-Donets

  • Prim y Prats, Juan (Spanish statesman)

    Juan Prim was a Spanish military leader and political figure who played an important role in the Revolution of 1868 that resulted in the dethronement of Isabella II, the Bourbon Spanish queen. Prim rose to military fame in the struggle to win the throne for Isabella II against her uncle, Don Carlos

  • Prim, Juan (Spanish statesman)

    Juan Prim was a Spanish military leader and political figure who played an important role in the Revolution of 1868 that resulted in the dethronement of Isabella II, the Bourbon Spanish queen. Prim rose to military fame in the struggle to win the throne for Isabella II against her uncle, Don Carlos

  • Prim-Rull Museum (museum, Reus, Spain)

    Reus: The municipal museum (Prim-Rull Museum) houses a prehistoric collection and educational, cultural, sporting, and recreational centres. Reus was the birthplace of the architect Antonio Gaudí. Reus is the site of an important textile industry, and its position in the centre of a wine-growing district accounts for what is…

  • prima Angélica, La (film by Saura [1973])

    Carlos Saura: …His La prima Angélica (1973; Cousin Angelica) was the first Spanish film to present the Spanish Civil War from the viewpoint of the losing Republican cause. It was shown uncensored but provoked bomb attacks in Spanish theatres.

  • Prima della rivoluzione (film by Bertolucci)

    Bernardo Bertolucci: His second feature, Prima della rivoluzione (1964; Before the Revolution), fared no better commercially but won notice at the Cannes film festival. Unable to obtain financial backing for his film projects, Bertolucci directed documentary films and worked with Julian Beck and his Living Theatre on Agonia (“Agony”), Amore…

  • Prima Facie (play by Miller)

    Jodie Comer: Theatre: …West End debut, starring in Prima Facie by Suzie Miller. The one-woman legal thriller centres on a defense barrister who represents men accused of sexual assault. Comer received a best actress Olivier Award for her performance. In 2023 the production transferred to Broadway, with Comer reprising the role. She earned…

  • prima facie duty (ethics)

    ethics: An ethics of prima facie duties: In the first third of the 20th century, the chief alternative to utilitarianism was provided by the intuitionists, especially W.D. Ross. Because of this situation, Ross’s normative position was often called “intuitionism,” though it would be more accurate and less confusing to…

  • prima prattica (music)

    Western music: The Baroque era: One, the prima prattica (or stile antico), was the universal style of the 16th century, the culmination of two centuries of adherence to Flemish models. The other, called seconda prattica, or stile moderno, referred to the new theatrical style emanating from Italy.

  • Prima, Louis (American musician)

    Louis Prima was an American jazz musician, songwriter, and bandleader best known for his exuberant onstage personality, raspy voice, and composition of the swing music classics “Sing, Sing, Sing” and “Jump, Jive, an’ Wail.” In the 1950s he led one of the first musical acts to regularly perform and

  • Prima, Louis Leo (American musician)

    Louis Prima was an American jazz musician, songwriter, and bandleader best known for his exuberant onstage personality, raspy voice, and composition of the swing music classics “Sing, Sing, Sing” and “Jump, Jive, an’ Wail.” In the 1950s he led one of the first musical acts to regularly perform and

  • Primacord (detonator)

    explosive: Detonating cord: …American manufacturers of cordeau, developed Primacord, based on French patents and constituting a core of PETN covered with various combinations of textiles, waterproofing materials, and plastics. The velocity is approximately 6,400 metres (21,000 feet) per second. Many types of Primacord are available for both military and commercial use, but the…

  • Primadizzi (Italian painter)

    Francesco Primaticcio was an Italian Mannerist painter, architect, sculptor, and leader of the first school of Fontainebleau. Primaticcio was first trained as an artist in Bologna, under Innocenzo da Imola and later Bagnacavallo. He also studied with Giulio Romano and assisted him in his work on

  • Primakov, Yevgeny (prime minister of Russia)

    Yevgeny Primakov was a Russian politician who served as prime minister of Russia (1998–99). Primakov grew up with his mother in Tbilisi, Georgia, then a republic of the Soviet Union. (He kept his early years cloaked in secrecy and would neither confirm nor deny reports that his parents were Jewish,

  • Primakov, Yevgeny Maksimovich (prime minister of Russia)

    Yevgeny Primakov was a Russian politician who served as prime minister of Russia (1998–99). Primakov grew up with his mother in Tbilisi, Georgia, then a republic of the Soviet Union. (He kept his early years cloaked in secrecy and would neither confirm nor deny reports that his parents were Jewish,

  • Primal Fear (film by Hoblit [1996])

    Richard Gere: He earned critical praise for Primal Fear (1996), a courtroom drama in which he starred as an attorney who defends an altar boy (played by Edward Norton) accused of murdering a prominent priest, and in 1999 he reteamed with Roberts in the lighthearted comedy Runaway Bride.

  • primal man

    Isaac ben Solomon Luria: …and Adam Qadmon, the symbolic “primordial man,” who is the highest configuration of the divine light, is rebuilt. Man plays an important role in this process through various kawwanot used during prayer and through mystical intentions involving secret combinations of words, all of which is directed toward the restoration of…

  • primal problem (linear programming)

    optimization: Standard formulation: In the primal problem the objective is replaced by the product (px) of a vector x = (x1, x2, x3, …, xn)T, whose components are the objective variables and where the superscript “transpose” symbol indicates that the vector should be written vertically,

  • primal religion

    creation myth: Nature and significance: …expression in archaic or “primitive” societies, often related to ritual presentation, is modelled on the structure of the cosmogonic myth. The masks, dances, and gestures are, in one way or another, aspects of the structure of the cosmogonic myth. This meaning may also extend to the tools that people…

  • Primal Scream (Scottish rock band)

    Portishead: …collection of groups that included Primal Scream, Ride, and Depeche Mode. During this time, Portishead’s core lineup was completed with the additon of Utley, a veteran jazz guitarist who had previously recorded with guitar viruoso Jeff Beck.

  • primaquine (drug)

    primaquine, synthetic drug used in the treatment of malaria, an infection caused by the protozoan parasite Plasmodium transmitted to humans by the bite of various species of Anopheles mosquitoes. Introduced into medicine in the 1950s, primaquine is one of an important series of chemically related

  • Primary (geology)

    geochronology: Classification of stratified rocks: …a successionally lowest category, the Primary (Urgebirge), composed mainly of crystalline rocks, (2) an intermediate category, or the Secondary (Flötzgebirge), composed of layered or stratified rocks containing fossils, and (3) a final or successionally youngest sequence of alluvial and related unconsolidated sediments (Angeschwemmtgebirge) thought to represent the most recent record…

  • primary abdominal pregnancy (medical condition)

    pregnancy: Ectopic pregnancy: Primary abdominal pregnancies, in which the fertilized egg attaches to an abdominal organ, and ovarian pregnancies are rarer still.

  • primary adrenocortical insufficiency (pathology)

    Addison disease, rare disorder defined by destruction of the outer layer of the adrenal glands, the hormone-producing organs located just above the kidneys. Addison disease, a kind of autoimmune disease, is rare because it only occurs when at least 90 percent of the adrenal cortex is destroyed. In

  • primary alcohol

    alcohol: Structure and classification of alcohols: …atom), the compound is a primary alcohol. A secondary alcohol has the hydroxyl group on a secondary (2°) carbon atom, which is bonded to two other carbon atoms. Similarly, a tertiary alcohol has the hydroxyl group on a tertiary (3°) carbon atom, which is bonded to three other carbons. Alcohols…

  • primary aldosteronism (pathology)

    hyperaldosteronism, increased secretion of the hormone aldosterone by the cells of the zona glomerulosa (the outer zone) of the adrenal cortex. The primary actions of aldosterone are to increase retention of salt and water and to increase excretion of potassium by the kidneys and to a lesser extent

  • primary alkyl halide (chemical compound)

    organohalogen compound: Structure and physical properties: …or I) are classified as primary, secondary, or tertiary according to the degree of substitution at the carbon to which the halogen is attached. In a primary alkyl halide, the carbon that bears the halogen is directly bonded to one other carbon, in a secondary alkyl halide to two, and…

  • primary amenorrhea (physical disorder)

    reproductive system disease: Amenorrhea: Primary amenorrhea is the absence of menstruation in a woman who has never previously menstruated. In rare cases, primary amenorrhea is due to gonadal dysgenesis, the failure of the ovaries to develop normally, and may be associated with chromosomal abnormalities. Instead of the normal female…

  • primary amine (chemical compound)

    amine: Amines are classified as primary, secondary, or tertiary depending on whether one, two, or three of the hydrogen atoms of ammonia have been replaced by organic groups. In chemical notation these three classes are represented as RNH2, R2NH, and R3N, respectively. A fourth category consists of quaternary ammonium compounds,…

  • primary amino group (chemistry)

    human respiratory system: Transport of carbon dioxide: Amino groups of the hemoglobin molecule react reversibly with carbon dioxide in solution to yield carbamates. A few amino sites on hemoglobin are oxylabile, that is, their ability to bind carbon dioxide depends on the state of oxygenation of the hemoglobin molecule. The change in…

  • primary amoebic meningoencephalitis (brain disease)

    Naegleria fowleri: …frequently fatal brain infection called primary amoebic meningoencephalitis (PAM).

  • primary auditory fibre (anatomy)

    human ear: Auditory nerve fibres: …central fibres, also called the primary auditory fibres, form the cochlear nerve, and the shorter, peripheral fibres extend to the bases of the inner and outer hair cells. They extend radially from the spiral ganglion to the habenula perforata, a series of tiny holes beneath the inner hair cells. At…

  • primary battery (electronics)

    materials testing: Corrosion: …is the principle of the galvanic cell or battery. Though useful in a battery, this reaction causes problems in a structure; for example, steel bolts in an aluminum framework may, in the presence of rain or fog, form multiple galvanic cells at the point of contact between the two metals,…

  • primary bone cancer (disease)

    bone cancer: Primary bone cancer—that is, cancer that arises directly in the bone—is relatively rare. In the United States, for example, only about 3,600 new cases of primary bone cancer are diagnosed each year. Most cancer that involves the bone is cancer that has spread (metastasized) from…

  • primary carbon footprint (ecology)

    carbon footprint: Carbon footprint calculation: …as part of an individual’s “primary” carbon footprint, representing the emissions over which an individual has direct control. The remainder of an individual’s carbon footprint is called the “secondary” carbon footprint, representing carbon emissions associated with the consumption of goods and services. The secondary footprint includes carbon emissions emitted by…

  • primary care

    medicine: Levels of health care: The first level represents primary health care, or first contact care, at which patients have their initial contact with the health-care system.

  • primary cell (electronics)

    materials testing: Corrosion: …is the principle of the galvanic cell or battery. Though useful in a battery, this reaction causes problems in a structure; for example, steel bolts in an aluminum framework may, in the presence of rain or fog, form multiple galvanic cells at the point of contact between the two metals,…

  • primary cell wall (plant anatomy)

    cell: Mechanical properties of wall layers: …the middle lamella and the primary cell wall, and many cells produce an additional layer, called the secondary wall. The middle lamella serves as a cementing layer between the primary walls of adjacent cells. The primary wall is the cellulose-containing layer laid down by cells that are dividing and growing.…

  • primary cellulose acetate (chemical compound)

    cellulose acetate: …cellulose acetate, or, more properly, cellulose triacetate. Triacetate is a high-melting (300 °C [570 °F]), highly crystalline substance that is soluble only in a limited range of solvents (usually methylene chloride). From solution, triacetate can be dry-spun into fibres or, with the aid of plasticizers, cast as a film. If…

  • Primary Chronicle, The (medieval historical work)

    The Primary Chronicle, medieval Kyivan Rus historical work that gives a detailed account of the early history of the eastern Slavs to the second decade of the 12th century. The chronicle, compiled in Kyiv about 1113, was based on materials taken from Byzantine chronicles, west and south Slavonic

  • primary circular reaction

    human behaviour: Piaget’s observations: …largely of simple acts (called primary circular actions) that are repeated for their own sake (e.g., sucking, opening and closing the fists, and fingering a blanket) and do not reflect any conscious intent or purpose on the infant’s part. During the third phase, lasting from the 4th to the 8th…

  • primary clarifier (sanitation engineering)

    wastewater treatment: Primary treatment: These tanks, also called primary clarifiers, provide about two hours of detention time for gravity settling to take place. As the sewage flows through them slowly, the solids gradually sink to the bottom. The settled solids—known as raw or primary sludge—are moved along the tank bottom by mechanical scrapers.…

  • primary color (optics)

    primary colour, any of a set of colours that can be used to mix a wide range of hues. There are three commonly used primary colour models: RGB (red, green, and blue), CMY (cyan, magenta, and yellow), and RYB (red, yellow, and blue). The colour variations between the models are due to the

  • Primary Colors (work by Klein)

    roman à clef: Primary Colors (1996) drew widespread attention in the United States as much for its protagonist—based closely on U.S. Pres. Bill Clinton—as for its anonymous author, later revealed to be political journalist Joe Klein.

  • Primary Colors (film by Nichols [1998])

    Elaine May: …and wrote the script for Primary Colors (1998), both of which Nichols directed; she won an Oscar nomination for the latter. She also acted in Allen’s comedy Small Time Crooks (2000).

  • primary colour (optics)

    primary colour, any of a set of colours that can be used to mix a wide range of hues. There are three commonly used primary colour models: RGB (red, green, and blue), CMY (cyan, magenta, and yellow), and RYB (red, yellow, and blue). The colour variations between the models are due to the

  • primary combustion (waste management)

    solid-waste management: Furnace operation: In primary combustion, moisture is driven off, and the waste is ignited and volatilized. In secondary combustion, the remaining unburned gases and particulates are oxidized, eliminating odours and reducing the amount of fly ash in the exhaust. When the refuse is very moist, auxiliary gas or…

  • primary commodity market (economics)

    market: Commodity markets: The behaviour of primary commodity markets is a serious matter when whole communities depend upon a single commodity for income or for employment and wages. The agricultural communities that form part of an industrial economy are therefore generally sheltered from the operation of supply and demand by government…

  • Primary Data (American company)

    Steve Wozniak: …to become chief scientist at Primary Data, which was involved in data virtualization; that business shut down in 2018. In 2020 he cofounded Efforce, which allows companies to fund energy efficiency projects through investing in a cryptocurrency token using blockchain technology.

  • primary dysmenorrhea (pathology)

    dysmenorrhea: Primary dysmenorrhea may occur a few days before the period, at the onset of bleeding, or during the total episode. The pain varies from a severe incapacitating distress to relatively minor and brief intense cramps. Other symptoms may include irritability, fatigue, backache, headache, leg pains,…

  • primary election (political process, United States)

    primary election, in the United States, an election to select candidates to run for public office. Primaries may be closed (partisan), allowing only declared party members to vote, or open (nonpartisan), enabling all voters to choose which party’s primary they wish to vote in without declaring any

  • primary electron (physics)

    electron tube: Secondary emission: The bombarding electrons are called primary, and the emitted electrons are designated secondary. The amount of secondary emission depends on the properties of the material and the energy and angle of incidence of the primary electrons. Material properties are characterized by the secondary-emission ratio, defined as the number of secondary…

  • primary ending (linguistics)

    Indo-European languages: Verbal inflection: ’ Verbs with primary endings were marked as non-past (present or future) in tense and indicative in mood—e.g., *H1és-ti ‘he is.’ (Indicative mood signifies objective statements and questions.) Verbs with secondary endings were unmarked for tense and mood but were normally used as past indicatives (e.g., *H1és-t ‘he…

  • primary enuresis (pathology)

    enuresis: …may additionally be classified as primary (when urinary continence has never been achieved), secondary (when continence was achieved for at least one year and then lost), nocturnal (occurring only during sleep), or diurnal (occurring during waking hours). The most prevalent form is nocturnal enuresis (also called bed-wetting and usually of…

  • primary explosive (chemical explosives)

    explosive: Types of chemical explosives: Primary explosives detonate by ignition from some source such as flame, spark, impact, or other means that will produce heat of sufficient magnitude. Secondary explosives require a detonator and, in some cases, a supplementary booster. A few explosives can be both primary and secondary depending…

  • primary fabric (geology)

    sedimentary rock: Fabric: …principal varieties of oriented fabrics: primary (or depositional) and secondary (or deformational). Primary fabrics are produced while the sediment is accumulating. For example, river currents and some submarine gravity flows generate sediments whose flaky and prismatic constituent particles have long or short axes parallel with one another to produce an…

  • primary fission trigger (weapon technology)

    thermonuclear warhead: Basic two-stage design: featuring a fission or boosted-fission primary (also called the trigger) and a physically separate component called the secondary. Both primary and secondary are contained within an outer metal case. Radiation from the fission explosion of the primary is contained and used to transfer energy to compress and ignite the secondary.…

  • primary forest (ecosystem)

    old-growth forest, a climax forest in the late stages of stand development containing large, old trees and a complex stand structure that has been generally undisturbed by human activities. The definition of an old-growth forest varies from country to country, but most definitions share an

  • primary generalized seizure (pathology)

    epilepsy: Generalized-onset seizures: …to by the older term petit mal. Minor movements such as blinking may be associated with absence seizures. After the short interruption of consciousness, the individual is mentally clear and able to resume previous activity. Absence seizures occur mainly in children and do not appear initially after age 20; they…

  • primary germ layer (biology)

    germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting of the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer). The germ layers form during the process of gastrulation, when the hollow ball of cells that

  • primary good (economics)

    economics: Definition: …prices—not only the prices of goods and services but the prices of the resources used to produce them. This involves the discovery of two key elements: what governs the way in which human labour, machines, and land are combined in production and how buyers and sellers are brought together in…

  • primary group (sociology)

    social group: Cooley’s distinction between primary and secondary groups, set forth in his Human Nature and the Social Order (1902). “Primary group” refers to those personal relations that are direct, face-to-face, relatively permanent, and intimate, such as the relations in a family, a group of close friends, and the like.…

  • primary health care

    medicine: Levels of health care: The first level represents primary health care, or first contact care, at which patients have their initial contact with the health-care system.

  • primary herpes simplex (pathology)

    herpes simplex: HSV-1: The term primary herpes simplex refers to the first appearance of the disease in an individual, usually a child, sometimes a young adult. The primary lesions are most frequently seen in the mouth, and inflammation of the mucous membrane lining the oral cavity may be severe; there…

  • primary hue (optics)

    primary colour, any of a set of colours that can be used to mix a wide range of hues. There are three commonly used primary colour models: RGB (red, green, and blue), CMY (cyan, magenta, and yellow), and RYB (red, yellow, and blue). The colour variations between the models are due to the

  • primary hyperaldosteronism (pathology)

    hyperaldosteronism: Primary hyperaldosteronism: In 1955 American internist Jerome Conn described a form of high blood pressure (hypertension) associated with low serum potassium concentrations (hypokalemia) in patients who had a benign tumor (adenoma) of the cells of the zona glomerulosa of the adrenal cortex. These patients had…

  • primary hypertension (pathology)

    hypertension: Classification: …the condition is classified as essential hypertension. (Essential hypertension is also called primary or idiopathic hypertension.) This is by far the most common type of high blood pressure, occurring in 90 to 95 percent of patients. Genetic factors appear to play a major role in the occurrence of essential hypertension.…

  • primary image (holography)

    optics: Theory: …virtual image (often called the primary image). There are two basic concepts that underlie this process: first, the addition of a coherent background (or reference) beam. Two optical fields may be considered, the complex amplitudes of which vary as the cosine of an angle proportional to the space coordinate and…

  • Primary Industries and Energy, Department of (government organization, Australia)

    Australian External Territories: The Department of Primary Industries and Energy is concerned with fishing rights in the external territories. These exclusive rights extend some 200 nautical miles (370 km) into the surrounding waters and increase considerably the economic interest in these territories. For the inhabited territories, an administrator or…

  • primary industry

    industry: Primary industry: This sector of a nation’s economy includes agriculture, forestry, fishing, mining, quarrying, and the extraction of minerals. It may be divided into two categories: genetic industry, including the production of raw materials that may be

  • primary intention (surgery)

    surgery: Present-day surgery: …general techniques of wound treatment; primary intention, in which all tissues, including the skin, are closed with suture material after completion of the operation; secondary intention, in which the wound is left open and closes naturally; and third intention, in which the wound is left open for a number of…

  • primary interjection (grammar)

    interjection: Primary and secondary interjections: A primary interjection is a word or phrase that can be used only as an interjection and not as another part of speech; examples include yikes, psst, and oops. A secondary interjection is a word or phrase that typically functions as another part of speech but…

  • primary literature

    information processing: Primary and secondary literature: The phrase primary literature is used to designate original information in various printed formats: newspapers, monographs, conference proceedings, learned and trade journals, reports, patents, bulletins, and newsletters. The scholarly journal, the classic medium of scientific communication, first appeared in 1665. Three hundred years later the number of…

  • primary lymphedema (disease)

    lymphedema: …traditionally classified into two forms: primary, which is genetic, and secondary, which arises from an outside cause. However, each of those forms can have aspects of the other; for example, some cancer patients who develop secondary lymphedema may be genetically predisposed to do so.

  • Primary markets and secondary markets: Two important cogs in the wheel of capitalism

    When you buy a new sweater at the Gap, you’re making a purchase on a primary market—that sweater had never been offered to the public before. Pick up a similar sweater at a thrift shop, and you’ve made a stop on the secondary market. The financial markets also have primary and secondary markets.

  • primary memory (computer technology)

    cache memory: …an extension of, a computer’s main memory. Both main memory and cache are internal random-access memories (RAMs) that use semiconductor-based transistor circuits. Cache holds a copy of only the most frequently used information or program codes stored in the main memory. The smaller capacity of the cache reduces the time…

  • Primary Mental Abilities Test (psychological test)

    L. L. Thurstone: …these techniques led to the Primary Mental Abilities Test (1938), which measured components of human intelligence such as reasoning ability, word fluency, verbal comprehension, facility with numbers, spatial visualization, and rote memory. Multiple-Factor Analysis (1947), his other major work, was an extensive rewriting of Vectors.

  • primary migration (geology)

    petroleum: Origin in source beds: …the source rock is termed primary migration.

  • primary mineral (mineral classification)

    primary mineral, in an igneous rock, any mineral that formed during the original solidification (crystallization) of the rock. Primary minerals include both the essential minerals used to assign a classification name to the rock and the accessory minerals present in lesser abundance. In contrast to

  • primary mirror (astronomy)

    telescope: Reflecting telescopes: …from the fact that the primary mirror reflects the light back to a focus instead of refracting it. The primary mirror usually has a concave spherical or parabolic shape, and, as it reflects the light, it inverts the image at the focal plane. The diagram illustrates the principle of a…

  • primary motivation (psychology)

    motivation: Motives are often categorized into primary, or basic, motives, which are unlearned and common to both animals and humans; and secondary, or learned, motives, which can differ from animal to animal and person to person. Primary motives are thought to include hunger, thirst, sex, avoidance of pain, and perhaps aggression…

  • primary motor area (anatomy)

    human nervous system: Thalamus: …turn provide input to the primary motor area of the frontal lobe. This system appears to provide coordinating and controlling influences that result in the appropriate force, sequence, and direction of voluntary motor activities. Output from the corpus striatum, on the other hand, is relayed by thalamic nuclei that have…

  • primary open angle glaucoma (pathology)

    eye disease: Glaucoma: …major classes of glaucoma are primary open angle glaucoma (POAG) and angle closure glaucoma.

  • primary osteoarthritis (pathology)

    arthritis: Osteoarthritis: Primary osteoarthritis is age-related, affecting 85 percent of individuals 75–79 years of age. Although the etiology is unknown, primary osteoarthritis is associated with decreased water-retaining capacity in the cartilage, analogous to a dried-up rubber band that can easily fall apart. Secondary osteoarthritis is caused by…

  • primary ovum (biology)

    oogenesis: These cells, known as the primary ova, number around 400,000. The primary ova remain dormant until just prior to ovulation, when an egg is released from the ovary. Some egg cells may not mature for 40 years; others degenerate and never mature.

  • primary parkinsonism (pathology)

    Parkinson disease, a degenerative neurological disorder that is characterized by the onset of tremor, muscle rigidity, slowness in movement (bradykinesia), and stooped posture (postural instability). The disease was first described in 1817 by British physician James Parkinson in his “Essay on the

  • primary party organization (Soviet Communist Party)

    Communist Party of the Soviet Union: …of the CPSU was the primary party organization, which was a feature in all factories, government offices, schools, and collective farms and any other body of any importance whatsoever. At the party’s peak size in the early 1980s, there were about 390,000 primary party organizations, and above this lowest level…

  • Primary PDC, Inc. (American company)

    Polaroid Corporation, American manufacturer of cameras, film, and optical equipment founded by Edwin Herbert Land (1909–91), who invented instant photography. The company originated in 1932 as the Land-Wheelwright Laboratories, which Land founded with George Wheelwright to produce Land’s first

  • primary phloem (plant tissue)

    phloem: Primary phloem is formed by the apical meristems (zones of new cell production) of root and shoot tips; it may be either protophloem, the cells of which are matured before elongation (during growth) of the area in which it lies, or metaphloem, the cells of…

  • primary phosphate (mineralogy)

    phosphate mineral: …can be grouped as: (1) primary phosphates that have crystallized from a liquid; (2) secondary phosphates formed by the alteration of primary phosphates; and (3) fine-grained rock phosphates formed at low temperatures from phosphorus-bearing organic material, primarily underwater.

  • primary pit field (plant anatomy)

    angiosperm: Structural basis of transport: …cell walls at areas called primary pit fields. Also, some substances pass out of cells into the apoplast and are transported by energy-requiring processes into the protoplast of another cell.

  • primary plant succession (ecology)

    primary succession, type of ecological succession (the evolution of a biological community’s ecological structure) in which plants and animals first colonize a barren, lifeless habitat. Species that arrive first in the newly created environment are called pioneer species, and through their

  • primary polycythemia (pathology)

    bloodletting: Bloodletting in the modern world: Polycythemia vera is a condition marked by the overproduction of platelets as well as red and white blood cells; blood is drawn in such cases to prevent the formation of blood clots. Leech therapy continues to be used to reduce blood congestion in veins and prevent tissue necrosis, especially…

  • primary porosity (geology)

    petroleum: Accumulation in reservoir beds: …the porosity and permeability is primary, or inherent, and (2) those in which they are secondary, or induced. Primary porosity and permeability are dependent on the size, shape, and grading and packing of the sediment grains and also on the manner of their initial consolidation. Secondary porosity and permeability result…

  • primary prevention (medicine)

    therapeutics: Preventive medicine: Primary prevention is the preemptive behavior that seeks to avert disease before it develops—for example, vaccinating children against diseases. Secondary prevention is the early detection of disease or its precursors before symptoms appear, with the aim of preventing or curing it. Examples include regular cervical…

  • primary process (psychology)

    magical thinking: Primary process thought is governed by the pleasure principle, whereby id-driven instinctual desires seek fulfillment without consideration of the constraints of the external world. Magical thinking—the belief that wishes can impose their own order on the material world—is a form of primary process thought. Secondary…

  • primary production (biology)

    primary productivity, in ecology, the rate at which energy is converted to organic substances by photosynthetic producers (photoautotrophs), which obtain energy and nutrients by harnessing sunlight, and chemosynthetic producers (chemoautotrophs), which obtain chemical energy through oxidation.

  • primary productivity (biology)

    primary productivity, in ecology, the rate at which energy is converted to organic substances by photosynthetic producers (photoautotrophs), which obtain energy and nutrients by harnessing sunlight, and chemosynthetic producers (chemoautotrophs), which obtain chemical energy through oxidation.