multiple sclerosis: Prevalence and types of multiple sclerosis: (RRMS), secondary-progressive (SPMS), primary-progressive (PPMS), and progressive-relapsing (PRMS). About 80–85 percent of patients are diagnosed initially with RRMS. In this form of the disease, onset is usually gradual, and there are alternating intervals of symptom exacerbation and complete symptom remission. In many patients with RRMS, symptoms may worsen…

Cartesianism: The way of ideas and the self: …Galileo’s distinction between real, or primary, properties of material bodies—such as size, shape, position, and motion or rest—which were thought to exist in bodies themselves, and sensible, or secondary, properties—such as colours, tactile feelings, sounds, odours, and tastes—which were thought to exist only in the mind. As Descartes assumes in…

rainbow: …common rainbow is the so-called primary bow, which results from light that emerges from the drop after one internal reflection.

petroleum production: Primary recovery: natural drive and artificial lift: Petroleum reservoirs usually start with a formation pressure high enough to force crude oil into the well and sometimes to the surface through the tubing. However, since production is invariably accompanied by a decline in reservoir pressure, “primary…

plant development: Origin of the primary organs: …and the primary root (radicle). The hypophysis will give rise to the radicle and the root cap; the cells of the suspensor will degenerate as the embryo matures.

sail: Primary sails are those that supply the chief propelling force in ordinary weather; secondary sails are those that aid the primary sails either by helping to balance the ship or by providing additional driving power. There are six classes of primary sales: square sails, gaff…

primary school, in many countries, an elementary school. It is the preferred term in such countries as Great Britain and France (French école primaire) and in most publications of the United Nations Educational, Scientific, and Cultural Organization. In the United States it is not a synonym but

sedimentary rock: Sedimentary structures: …which they occur are called primary sedimentary structures. Examples include bedding or stratification, graded bedding, and cross-bedding. Sedimentary structures that are produced shortly after deposition and as a result of compaction and desiccation are called penecontemporaneous sedimentary structures. Examples include mud cracks and load casts. Still other sedimentary structures like…

human nervous system: Muscle spindles: …to be of three kinds: primary sensory endings, secondary sensory endings, and plate motor endings. There are approximately equal numbers of primary and secondary sensory endings, so they may be considered equally important. However, the primary, or annulo-spiral, ending has traditionally attracted the most attention, largely through its prominent appearance…

primary sex character, features present at birth that comprise the external and internal genitalia, including the penis and testes and the vagina and ovaries. Primary sexual characteristics are distinguished from secondary sexual characteristics, which emerge during the prepubescent through

primary sex character, features present at birth that comprise the external and internal genitalia, including the penis and testes and the vagina and ovaries. Primary sexual characteristics are distinguished from secondary sexual characteristics, which emerge during the prepubescent through

water supply system: Standards: Primary standards are designed to protect public health, whereas secondary standards are based on aesthetic factors rather than on health effects. Primary standards specify maximum contaminant levels for many chemical, microbiological, and radiological parameters of water quality. They reflect the best available scientific and engineering…

loran: A primary station broadcasts an uninterrupted series of pulses of fixed duration and at a fixed rate (e.g., of 50 microseconds’ duration at a rate of 25 pulses per second). A secondary station, 200–300 miles (320–480 km) away, automatically transmits its own signals, maintaining a frequency…

sedimentary rock: Types: …termed well-bedded, a type of primary stratification.

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

plant disease: Symptoms: Primary symptoms are the direct result of pathogen activity on invaded tissues (e.g., swollen “clubs” in clubroot of cabbage and “galls” formed by feeding of the root knot nematode). Secondary symptoms result from the physiological effects of disease on distant tissues and uninvaded organs (e.g.,…

cycadophyte: Stem: …palms from activity of a primary thickening meristem (PTM) lateral to the apical meristem, which produces much greater increments of cortical parenchyma than would result if only an apical meristem were present. This is an important difference between cycadophytes and coniferophytes, for in the latter there is no PTM and…

human digestive system: The teeth: …as the deciduous, milk, or primary dentition, is acquired gradually between the ages of six months and two years. As the jaws grow and expand, these teeth are replaced one by one by the teeth of the secondary set. There are five deciduous teeth and eight permanent teeth in each…

wastewater treatment: Wastewater treatment and disposal: Primary treatment removes about 60 percent of total suspended solids and about 35 percent of BOD; dissolved impurities are not removed. It is usually used as a first step before secondary treatment. Secondary treatment removes more than 85 percent of both suspended solids and BOD.…

excretion: Mammals: Primary urine is formed by filtration from the blood. From this primary urine certain substances are reabsorbed into the blood and other substances are secreted into the primary urine from the blood. The word secretion is used by renal physiologists to imply transport, other than…

photoreception: Central processing of visual information: …their axons exclusively to the primary visual area (V1) in the occipital lobe of the cortex. The V1 contains six layers, each of which has a distinct function. Axons from the LGN terminate primarily in layers four and six. In addition, cells from V1 layer four feed other layers of…

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.…

earthquake: Principal types of seismic waves: The P seismic waves travel as elastic motions at the highest speeds. They are longitudinal waves that can be transmitted by both solid and liquid materials in the Earth’s interior. With P waves, the particles of the medium vibrate in a manner similar to sound waves—the…

xylem: …(apical meristems) give rise to primary xylem. In woody plants, secondary xylem constitutes the major part of a mature stem or root and is formed as the plant expands in girth and builds a ring of new xylem around the original primary xylem tissues. When this happens, the primary xylem…

moss animal: Budding: …budding originates from either a primary zooid (the ancestrula) or a statoblast. The ancestrula is formed by the metamorphosis of a sexually produced larva. New zooids bud from the ancestrula to produce colonies of definite shape and growth habit. In the phylactolaemates, the primitive zooids are cylindrical in form, and…

primate, in zoology, any mammal of the group that includes the lemurs, lorises, tarsiers, monkeys, apes, and humans. The order Primates, including more than 500 species, is the third most diverse order of mammals, after rodents (Rodentia) and bats (Chiroptera). Although there are some notable

primate, in Christianity, an ecclesiastical title for a bishop in some churches who has precedence over a number of other bishops. In the early church, it was one of several titles, including metropolitan, exarch, and patriarch, used to designate a chief bishop who had certain rights of

Frederick Wiseman: Documentaries: …Court [1973]), animal experimentation (Primate [1974]), a city welfare office (Welfare [1975]), an exclusive department store (The Store [1983]), an intensive-care hospital ward (Near Death [1989]), and a public park (Central Park [1990]). In his films Wiseman eschewed polemics in favour of a complex and sympathetic

primate, in zoology, any mammal of the group that includes the lemurs, lorises, tarsiers, monkeys, apes, and humans. The order Primates, including more than 500 species, is the third most diverse order of mammals, after rodents (Rodentia) and bats (Chiroptera). Although there are some notable

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

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

primatology, the study of the primate order of mammals—other than recent humans (Homo sapiens). The species are characterized especially by advanced development of binocular vision, specialization of the appendages for grasping, and enlargement of the cerebral hemispheres. Nonhuman primates provide

primavera, (species Cybistax donnel-smithii), timber tree of Central America with brilliant yellow flowers, or its firm light wood, often called white mahogany. Although the tree is unrelated to true mahogany, the wood resembles it in being easy to work, lustrous, and free of tendency to warp. When

divine office: …of monastic origin, as was prime, recited in the early morning before being suppressed in 1964. The office has for centuries been primarily the responsibility of monks, who sang it in choir, and priests, who often recited it privately. The Second Vatican Council encouraged the celebration of lauds and vespers…

prime, any positive integer greater than 1 that is divisible only by itself and 1—e.g., 2, 3, 5, 7, 11, 13, 17, 19, 23, …. A key result of number theory, called the fundamental theorem of arithmetic (see arithmetic: fundamental theory), states that every positive integer greater than 1 can be

accounting: Cost finding: …are recognized under this method: prime costs and factory overhead costs. Prime costs are those that can be traced directly to a specific batch, or job lot, of products. These are the direct labour and direct materials costs of production. Overhead costs, on the other hand, are those that can…

credit score: …scores and are known as prime customers in the credit market. These high scores serve as a positive signal to lenders, making it easier for them to extend credit to such individuals. Since people with good credit scores are less likely to default on a loan, lenders usually end up…

Michael Ritchie: Films: Prime Cut (1972) was a neo-noir with Lee Marvin as Nick Devlin, a mob enforcer who is tasked with collecting a debt from a Kansas cattle rancher (played by Hackman) who also is involved in enforced prostitution; Sissy Spacek (in her film debut) portrayed one…

fundamental theorem of arithmetic, Fundamental principle of number theory proved by Carl Friedrich Gauss in 1801. It states that any integer greater than 1 can be expressed as the product of prime numbers in only one

knot theory: …be so resolved are called prime.

Greenwich meridian, an imaginary line, last established in 1851, that was used to indicate 0° longitude. It passes through Greenwich, a borough of London, and terminates at the North and South poles. Because it indicated 0° longitude, it was also known as the prime meridian. It served as the

prime minister, the head of government in a country with a parliamentary or semipresidential political system. In such systems, the prime minister—literally the “first,” or most important, minister—must be able to command a continuous majority in the legislature (usually the lower house in a

prime minister of India, the leader of the Council of Ministers that aids and advises the president of India and serves as the executive head of the Republic of India. The prime minister (Hindi: pradhan mantri) should be a member of a house of parliament, either the Lok Sabha or the Rajya Sabha—if

The Prime Minister, novel by Anthony Trollope, published serially during 1875 and 1876 and in book form in 1876. Considered by modern critics to represent the apex of the Palliser novels, it is the fifth in the series and sustains two plotlines. One records the clash between the Duke of Omnium, now

Australia, established as a federated union in 1901, is a constitutional monarchy, and its government is led by a prime minister, generally the leader of the majority political party or coalition in the federal House of Representatives. This is a chronologically ordered list of the prime ministers,

jet engine: The prime mover: The gas turbine operates on the Brayton cycle in which the working fluid is a continuous flow of air ingested into the engine’s inlet. The air is first compressed by a turbocompressor to a pressure ratio of typically 10 to 40 times the…

the Five Ways: …begun with a first or prime mover that had not itself been moved or acted upon by any other agent. Aristotle sometimes called this prime mover “God.” Aquinas understood it as the God of Christianity.

prime, any positive integer greater than 1 that is divisible only by itself and 1—e.g., 2, 3, 5, 7, 11, 13, 17, 19, 23, …. A key result of number theory, called the fundamental theorem of arithmetic (see arithmetic: fundamental theory), states that every positive integer greater than 1 can be

prime number theorem, formula that gives an approximate value for the number of primes less than or equal to any given positive real number x. The usual notation for this number is π(x), so that π(2) = 1, π(3.5) = 2, and π(10) = 4. The prime number theorem states that for large values of x, π(x) is

A prime number is any number that can be divided only by 1 and itself. For example, 3 is a prime number because the only numbers that divide it are 1 and 3. The number 4 is not, because it can be divided by 1, 2, and 4. The prime numbers are sometimes called the chemical elements of the numbers,

Jean-Paul Sartre: Early life and writings: …La Force de l’âge (1960; The Prime of Life), provide an intimate account of Sartre’s life from student years until his middle 50s. It was also at the École Normale Supérieure and at the Sorbonne that he met several persons who were destined to be writers of great fame; among…

The Prime of Miss Jean Brodie, novel by Muriel Spark, published in 1961 and adapted for the stage in 1966. The story of an eccentric Edinburgh teacher who inspires cultlike reverence in her young students, the novel was Spark’s best-known work. It explores themes of innocence, betrayal, and cold

Maggie Smith: …in the title role of The Prime of Miss Jean Brodie (1969), for which she received an Academy Award for best actress. Her subsequent stage appearances with the National Theatre included roles in William Wycherley’s The Country-Wife (1969), Farquhar’s The Beaux’ Stratagem (1970), and Henrik Ibsen’s Hedda Gabler

Helen Mirren: Television work and Broadway: …in the BBC television series Prime Suspect. The show aired for seven seasons and earned her three BAFTA Awards (1992–94) and two Emmy Awards (1996 and 2007). She also won Emmy Awards for titular performances in the TV movie The Passion of Ayn Rand (1999) and the miniseries Elizabeth I…

Jane Fonda: … My Life So Far (2005); Prime Time (2011), a volume of advice about aging; and What Can I Do?: My Path from Climate Despair to Action (2020). The documentary Jane Fonda in Five Acts (2018) chronicled her life and career.

Deion Sanders is an American gridiron football player, baseball player, and football coach who is the only person to have played in both a Super Bowl and a World Series. Known for his flashy personality and outspokenness, Sanders was a middling professional baseball player but is widely considered

Toronto Maple Leafs: Joe Primeau—all under age 26.

fuse: It is distinct from the primer or firing pin that initiates the launching of a rocket or artillery shell. Impact fuzes function as they hit the target. Time fuzes delay the functioning for a certain period from the starting time. Command fuzes function on signal from a remote-control point. Proximity…

Jovita Idár: Journalist and activist: …Texas, the Idár family organized El Primer Congreso Mexicanista (the First Mexican Congress), which was the beginning of the modern civil rights movement for Mexican Americans. The meeting brought together Mexican American men and women who wanted to work together to fight injustice, focusing on economic and educational inequality. Idár…

Gwendolyn Brooks: Later work and legacy: Her latter works include Primer for Blacks (1980), Young Poet’s Primer (1980), To Disembark (1981), The Near-Johannesburg Boy, and Other Poems (1986), Blacks (1987), Winnie (1988), and Children Coming Home (1991).

Felipe Guamán Poma de Ayala: …nobleman who wrote and illustrated El primer nueva corónica y buen gobierno (1612–15; “The First New Chronicle and Good Government”), a critical account of Spanish rule in Peru.

chemoreception: Primer pheromones: Primer pheromones are important in aspects of social physiology in a range of animals. In mammals they are influential in coordinating reproductive physiology, and compounds excreted in the urine are especially important (see below Behavior and chemoreception: Mammals). For example, the physiology of

Pedro de Oña: His most famous work is Primera parte de Arauco domado (1596; “First Part of the Araucan Conquest”), a verse epic in rhymed couplets depicting the deeds of the Marquis of Canete, viceroy of Peru from 1556 to 1560, based in part on the famous La Araucana (1569, 1578, 1589; “The…

Luis Barahona de Soto: …Angelica”), more commonly known as Las lágrimas de Angélica (“The Tears of Angelica”), a continuation of the Angelica and Medoro episode in Ludovico Ariosto’s Orlando furioso.

Uruguay: Transportation and telecommunications: The government-owned airline, Primeras Líneas Uruguayas de Navegación Aérea (PLUNA), links Montevideo with the provincial capitals and international destinations.

Travelers Insurance, leading American insurance company with a history of mergers, acquisitions, and spin-offs, largely in the insurance and financial services industries. The Travelers Insurance Company was founded in 1864 by James Batterson, a stonecutter. That year it sold the first accident

Sor Juana Inés de la Cruz: Primero sueño (First Dream): …as the Primero sueño (1692; First Dream, published in A Sor Juana Anthology, 1988), is both personal and universal. The date of its writing is unknown. It employs the convoluted poetic forms of the Baroque to recount the torturous quest of the soul for knowledge. In the poem’s opening, as…

Martin Short: Career: …the parody television talk show Primetime Glick.

Sam Donaldson: …he served as cohost of Primetime Live. During his second stint as ABC’s chief White House correspondent, he was also the anchor of the investigative program 20/20. From 1999 to 2001 Donaldson hosted a live Webcast (a broadcast over the World Wide Web), and from 2001 to 2004 he anchored…

Sam Donaldson: …he served as cohost of Primetime Live. During his second stint as ABC’s chief White House correspondent, he was also the anchor of the investigative program 20/20. From 1999 to 2001 Donaldson hosted a live Webcast (a broadcast over the World Wide Web), and from 2001 to 2004 he anchored…

the Supremes, American pop-soul vocal group whose tremendous popularity with a broad audience made its members among the most successful performers of the 1960s and the flagship act of Motown Records. Not only were the Supremes the Motown label’s primary crossover act, they also helped change the

Europe: Agricultural organization: …feature is the production of primeurs: table fruits, new potatoes, vegetables, salad crops, and flowers, produced when prices are high and made possible by the early arrival of spring to the coasts of Brittany, Cornwall, and southern France.

Olga Tokarczuk: Novels and other works: …Prawiek i inne czasy (1996; Primeval and Other Times), established Tokarczuk as an imaginative author and a crucial Polish voice. The saga follows the inhabitants of a mythical Polish village through successive generations in the 20th century. In 1998 Tokarczuk published Dom dzienny, dom nocny (House of Day, House of…

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

André van Hasselt: …Hasselt’s first book of poems, Primevères (1834; “Primroses”), was the first important collection in the history of modern Belgium. His poetry continued to display the influence of Hugo and of the German tradition. Van Hasselt’s most innovative work was the Études rhythmiques (published in Poëmes, paraboles, odes, et études rhythmiques,…

Fortuna, in Roman religion, goddess of chance or lot who became identified with the Greek Tyche; the original Italian deity was probably regarded as the bearer of prosperity and increase. As such she resembles a fertility deity, hence her association with the bounty of the soil and the fruitfulness

calculus: Differentiation and integration: This is called the (indefinite) integral of the function y = x2, and it is written as ∫x2dx. The initial symbol ∫ is an elongated S, which stands for sum, and dx indicates an infinitely small increment of the variable, or axis, over which the function is being summed.…

Poor Clare, any member of the Franciscan Order of St. Clare, a Roman Catholic religious order of nuns cofounded by St. Clare and St. Francis of Assisi in Italy in 1212. The Poor Clares are considered the second of the three Franciscan orders. Because each convent of Poor Clares is largely

Western painting: The 20th century: The art of supposedly “primitive” peoples had a special appeal in the early years of the 20th century. Gauguin, who lived in Tahiti in his last years, proved prophetic not only in the forms he adopted but in the spirit of his approach. Maurice de Vlaminck and André Derain,…

Primitive Baptist, member of any of the conservative, independent Baptist church congregations in the United States that oppose centralized administrative associations and organized mission societies. In the 1820s and ’30s some Baptists began to protest the educational and mission societies that

Coleoptera: Annotated classification: Family Agyrtidae (primitive carrion beetles) Scavengers of decaying organic material; inhabit damp, cool environments; dark-colored. Family Hydraenidae (minute moss beetles) Small, 1.2–2.5 mm; found in brackish or intertidal pools and along streams. Family

Early Christian art, architecture, painting, and sculpture from the beginnings of Christianity until about the early 6th century, particularly the art of Italy and the western Mediterranean. (Early Christian art in the eastern part of the Roman Empire is usually considered to be part of Byzantine

history of early Christianity, the development of the early Christian church from its roots in the Jewish community of Roman Palestine to the conversion of Constantine I and the convocation of the First Council of Nicaea. For a more extensive treatment of the history and beliefs of the Christian

Burnett Hillman Streeter: This work was followed by The Primitive Church (1929), in which he argued that there were three systems (not one) of church government in the earliest Christian churches.

culture: Economic systems: …there was considerable discussion of “primitive communism.” This doctrine came to be interpreted as meaning that private property, the private right to hold or use, was nonexistent in primitive society. It was extended also to communism in wives and children in some tribes; this was interpreted to be a vestige…

Jeff Beck: …such albums as Mick Jagger’s Primitive Cool (1987) and Roger Waters’s Amused to Death (1992). In 1989 Jeff Beck’s Guitar Shop won a Grammy Award for best rock instrumental performance.

Sir Edward Burnett Tylor: Tylor’s concept of progressive development: …chiefly upon the publication of Primitive Culture. In it he again traced a progressive development from a savage to a civilized state and pictured primitive man as an early philosopher applying his reason to explain events in the human and natural world that were beyond his control, even though his…

primitive culture, in the lexicon of early anthropologists, any of numerous societies characterized by features that may include lack of a written language, relative isolation, small population, relatively simple social institutions and technology, and a generally slow rate of sociocultural change.

Sou Fujimoto: …philosophy, which he dubbed “primitive future,” was evident in his Final Wooden House (2008) in Kumamoto, Japan. The structure was composed of large cedar beams stacked like blocks that allowed occupants to interpret the space according to their own needs and encouraged flexible use of surfaces as, variously, walls,…

John Ferguson McLennan: …evolution, outlined in his book Primitive Marriage: An Enquiry into the Origin of the Form of Capture in Marriage Ceremonies (1865, reissued as Studies in Ancient History, 2nd series, 1896, and again as Primitive Marriage, 1970).

asteroid: Origin and evolution of the asteroids: …asteroids, originally formed from so-called primitive material (i.e., material of solar composition with the volatile components removed), were heated, perhaps by short-lived radionuclides or solar magnetic induction, to the point where their interiors melted and geochemical processes occurred. In certain cases, temperatures became high enough for metallic iron to separate…

Primitive Methodist Church, conservative Protestant church that developed in England. It was formed in 1811 by Hugh Bourne and William Clowes after their expulsion from the Wesleyan Methodist Connection. The Primitive Methodists differed from the Wesleyan Methodists primarily in encouraging camp

Primitive Methodist Church: The Primitive Methodist Church, U.S.A., grew as a result of the work of missionaries of the Primitive Methodist Church of England who settled in the United States in 1829. The American group separated from the British church in 1840, and the English Primitive Methodist Church merged…

Scandinavian languages: History of Old Scandinavian: It is known as Proto-Scandinavian, or Ancient Scandinavian, but shows few distinctively North Germanic features. The earliest inscriptions may reflect a stage, sometimes called Northwest Germanic, prior to the splitting of North and West Germanic (but after the separation of Gothic). Only after the departure of the Angles and…

Grandma Moses: Her naive style (labeled “American Primitive” by art historians) was acclaimed for its purity of colour, its attention to detail, and its vigour. Her other notable paintings include Black Horses (1942), Out for the Christmas Trees (1946), The Old Oaken Bucket (1946), From My Window (1949), and Making Apple…

number game: Pythagorean triples: …common factor—the set is a primitive Pythagorean triple.

foundations of mathematics: Recursive definitions: …S, and substitution) are called primitive recursive. Gödel used this concept to make precise what he meant by “effectively enumerable.” A set of natural numbers is said to be recursively enumerable if it consists of all f(n) with n ∊ ℕ, where f ∶ ℕ → ℕ is a primitive…

St. Francis of Assisi: The Franciscan rule of St. Francis of Assisi: …friars, a simple rule (Regula primitiva, “Primitive Rule”) drawn from passages in the Bible: “To follow the teachings of our Lord Jesus Christ and to walk in his footsteps.” He then led the group of 12 disciples to Rome to seek the approval of Pope Innocent III, an important…

St. Teresa of Ávila: …the first monastery of the Primitive Rule at Duruelo, Spain.

primitive culture, in the lexicon of early anthropologists, any of numerous societies characterized by features that may include lack of a written language, relative isolation, small population, relatively simple social institutions and technology, and a generally slow rate of sociocultural change.