Indigenous American peoples: Early cultural development: Known to archaeologists as Formative or pre-Classic peoples, these groups established agricultural villages by 1800 bce. From this point until the beginning of the Common Era, Formative peoples such as the Olmec built large towns and developed increasingly complex architecture, art, and religion.

Chinese languages: Pre-Classical Chinese: The history of the Chinese language can be divided into three periods, pre-Classical (c. 1500 bc–c. ad 200), Classical (c. 200–c. 1920), and post-Classical Chinese (with important forerunners as far back as the Tang dynasty).

Archaic period, in history and archaeology, the earliest phases of a culture; the term is most frequently used by art historians to denote the period of artistic development in Greece from about 650 to 480 bc, the date of the Persian sack of Athens. During the Archaic period, Greek art became less

sacrament: Sacramental ideas and practices of pre-Columbian America: The recurrent and widespread practice of holding sacred meals in the sacramental system, in addition to being well documented in the Greco-Roman world, also occurred in the pre-Columbian Mexican calendrical ritual in association with human sacrifice on a grand scale. In the May…

pre-Columbian civilizations, the aboriginal American Indian cultures that evolved in Mesoamerica (part of Mexico and Central America) and the Andean region (western South America) prior to Spanish exploration and conquest in the 16th century. The pre-Columbian civilizations were extraordinary

sound recording: The phonograph disc: …the plastic disc—a process called pre-emphasis. Upon playback this sequence is reversed in a process called equalization, providing the listener with a linear and realistic sound.

pre-exposure prophylaxis (PrEP), medication taken prior to having unprotected sex or sharing needles that helps lower the risk of becoming infected with HIV (human immunodeficiency virus), the cause of AIDS (acquired immunodeficiency syndrome). The U.S. Food and Drug Administration (FDA) approved

archaeology: First steps to archaeology: … coined it in his book Pre-historic Times (1865).

Anatolian art and architecture: Pre-Hittite period: Anatolian excavations have done much to illuminate the genesis of visual arts in the earliest settled communities. In a Neolithic setting, at Çatalhüyük in the Konya plain, a township covering more than 15 acres (6 hectares) and dating from…

church year: Roman Catholic Church: …of Time, the season of Pre-Lent was eliminated, and two cycles were provided: (1) the principal seasons, Sundays, and holy days from Advent to Pentecost and (2) a schedule of 33 Sundays per annum to be observed in numbered sequence in place of the Sundays previously designated “after Epiphany” and…

transcription: …of transcription is called a pre-mRNA. Pre-mRNA is extensively edited through splicing before the mature mRNA is produced and ready for translation by the ribosome, the cellular organelle that serves as the site of protein synthesis. Transcription of any one gene takes place at the chromosomal location of that gene,…

Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4

Pre-Raphaelite Brotherhood, group of young British painters who banded together in 1848 in reaction against what they conceived to be the unimaginative and artificial historical painting of the Royal Academy and who purportedly sought to express a new moral seriousness and sincerity in their works.

Pre-Raphaelite Brotherhood, group of young British painters who banded together in 1848 in reaction against what they conceived to be the unimaginative and artificial historical painting of the Royal Academy and who purportedly sought to express a new moral seriousness and sincerity in their works.

Pre-Romanticism, cultural movement in Europe from about the 1740s onward that preceded and presaged the artistic movement known as Romanticism (q.v.). Chief among these trends was a shift in public taste away from the grandeur, austerity, nobility, idealization, and elevated sentiments of

pre-Socratic philosophy, in the history of Western philosophy, the cosmological and naturalistic speculations of ancient Greek philosophers who were predecessors or contemporaries of Socrates (c. 470–399 bce). Among the most significant pre-Socratic philosophers are the Milesians Thales (c.

Whitney Houston: Stardom: …Waiting to Exhale (1995) and The Preacher’s Wife (1996), and the soundtrack of each film generated hit singles for her.

Ecclesiastes, (Preacher), an Old Testament book of wisdom literature that belongs to the third section of the biblical canon, known as the Ketuvim (Writings). In the Hebrew Bible, Ecclesiastes stands between the Song of Solomon and Lamentations and with them belongs to the Megillot, five scrolls

Dominican, one of the four great mendicant orders of the Roman Catholic Church, founded by St. Dominic in 1215. Its members include friars, nuns, active sisters, and lay Dominicans. From the beginning the order has been a synthesis of the contemplative life and the active ministry. The members live

oratory: …Greek and Roman rhetoric was religious oratory. For more than 1,000 years after Cicero the important orators were churchmen rather than politicians, lawyers, or military spokesmen. This tradition derived from the Judaean prophets, such as Jeremiah and Isaiah, and in the Christian Era, from the Apostle Paul, his evangelistic colleagues,…

Norodom Sihanouk was twice king of Cambodia (1941–55 and 1993–2004), who also served as prime minister, head of state, and president. He attempted to steer a neutral course for Cambodia in its civil and foreign wars of the late 20th century. Sihanouk was, on his mother’s side, the grandson of King

Cambodia: Cultural institutions: In 2008 the Temple of Preah Vihear, dedicated to the worship of Shiva, was also named a World Heritage site.

Cambodia, country in mainland Southeast Asia. Cambodia is largely a land of plains and great rivers and lies amid important overland and river trade routes linking China to India and Southeast Asia. The influences of many Asian cultures, alongside those of France and the United States, can be seen

Preakness Stakes, a 1 3 16 -mile (about 1,900-metre) flat race for three-year-old Thoroughbred horses, held at Pimlico Race Course, Baltimore, Maryland, U.S., annually in mid-May. Fillies carry 121 pounds (55 kg), colts 126 pounds (57 kg). The Preakness Stakes is the second (and shortest) race of

treaty: The preamble provides the names and styles of the contracting parties and is a statement of the treaty’s general objectives. It is usually followed by the articles containing the agreed-upon stipulations. If the treaty is concluded for a definite period, a statement of the period follows;…

Indonesia: Growth and impact of the Dutch East India Company: …received the cession of the Preanger regions of western Java.

Preanger system, revenue system introduced in the 18th century in Preanger (now Priangan) of western Java (now part of Indonesia) by the Dutch East India Company and continued by the Dutch until 1916. In this system the company required its regents to deliver specified annual quotas of coffee but

Preanger system, revenue system introduced in the 18th century in Preanger (now Priangan) of western Java (now part of Indonesia) by the Dutch East India Company and continued by the Dutch until 1916. In this system the company required its regents to deliver specified annual quotas of coffee but

primitive culture: European peasant society: These workers are called prebendal in English (French provendiers) because they were provisioned and housed at the master’s expense. The only difference between a prebendal worker and a slave was the freedom of the prebendal worker to leave if he was dissatisfied.

nutraceutical: Diverse groups of nutraceuticals: …lactating women, and probiotic and prebiotic yogurt. (Prebiotics are nondigestible nutrients that serve as an energy source for bacteria that assist with the breakdown of food in the human digestive tract.)

Raúl Prebisch was an Argentine economist and statesman. Serving in various positions in Argentine government and academia, he advised developing countries to stimulate domestic manufacturing to reduce their reliance on imports and thus their dependence on the industrialized nations. He also

Edward Preble was a commander of U.S. naval forces during the most active portion of the Tripolitan War (1801–05). The son of provincial military officer, merchant, and political leader Jedidiah Preble and of Mehetable Bangs Roberts, Edward Preble received his early education in his native Falmouth

Stone Age: Neolithic: …late Dryas period during the Pre-Boreal and the Boreal (c. 8000–5500 bce, determined by radiocarbon dating) caused a remarkable change in late glacial flora and fauna. Thus, the Mediterranean zone became the center of the first cultural modifications leading from the last hunters and food gatherers to the earliest farmers.…

Stone Age: Neolithic: …late Dryas period during the Pre-Boreal and the Boreal (c. 8000–5500 bce, determined by radiocarbon dating) caused a remarkable change in late glacial flora and fauna. Thus, the Mediterranean zone became the center of the first cultural modifications leading from the last hunters and food gatherers to the earliest farmers.…

Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4

Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4

Africa: The Precambrian: The oldest rocks consist of gneisses, granites, metasediments, and metavolcanic rocks 3.6 to 2.5 billion years old; all are variably deformed and metamorphosed to some degree. The best-preserved assemblages occur in the Kaapvaal and Zimbabwe cratons and contain large deposits of gold and sulfide…

Canadian Shield, one of the world’s largest geologic continental shields, centred on Hudson Bay and extending for 8 million square km (3 million square miles) over eastern, central, and northwestern Canada from the Great Lakes to the Canadian Arctic and into Greenland, with small extensions into

Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4

Cambrian Period: Fossil record of the Precambrian-Cambrian transition: The preservation of the record of the Precambrian-Cambrian transition was significantly affected by global changes in sea level. During latest Precambrian time, the sea level was relatively low, resulting in spatially restricted oceans and expanded continents. Throughout much of the Cambrian, rising seas…

capillary: …intermediate vessels called precapillaries, or metarterioles, that, unlike the capillaries, have muscle fibres that permit them to contract; thus the precapillaries are able to control the emptying and filling of the capillaries.

John Dewey: The precarious: For Dewey, a precarious event is one that somehow makes ongoing experience problematic; thus, any obstacle, disruption, danger, or surprise of any kind is precarious. As noted earlier, because humanity is a part of nature, all things that humans encounter in their daily…

France: Diffusion of political power: …duration of his life) and precarious contract (a powerful lord received certain services in return for the use of his land for a limited time under advantageous conditions). In the 8th century the Pippinids increased their personal circle of followers. Charlemagne sought to establish a personal bond with the entire…

precast concrete, Concrete cast into structural members under factory conditions and then brought to the building site. A 20th-century development, precasting increases the strength and finish durability of the member and decreases time and construction costs. Concrete cures slowly; the design

James Fenimore Cooper: Early years: Precaution (1820) was a plodding imitation of Jane Austen’s novels of English gentry manners. It is mainly interesting today as a document in the history of American cultural colonialism and as an example of a clumsy attempt to imitate Jane Austen’s investigation of the ironic…

precautionary principle, approach in policy making that legitimizes the adoption of preventative measures to address potential risks to the public or environment associated with certain activities or policies. The concept of the precautionary principle emerged in the 1970s–80s in German

vena cava: …of two major trunks, the anterior and posterior venae cavae, that deliver oxygen-depleted blood to the right side of the heart. The anterior vena cava, also known as the precava, drains the head end of the body, while the posterior vena cava, or postcava, drains the tail, or rear, end.…

precedent, in law, a judgment or decision of a court that is cited in a subsequent dispute as an example or analogy to justify deciding a similar case or point of law in the same manner. Common law and equity, as found in English and American legal systems, rely strongly on the body of established

library: The role of the European monasteries: …under the supervision of a precentor, one of whose duties was to issue the books and take daily inventory of them. Scriptoria, the places where manuscripts were copied out, were a common feature of the monasteries—again, especially in those of the Benedictine order, where there was a strict obligation to…

Ram Mohan Roy: Early life: …four Gospels, under the title Precepts of Jesus, the Guide to Peace and Happiness.

precession, phenomenon associated with the action of a gyroscope or a spinning top and consisting of a comparatively slow rotation of the axis of rotation of a spinning body about a line intersecting the spin axis. The smooth, slow circling of a spinning top is precession, the uneven wobbling is

Martin Julian Buerger: …of Buerger’s innovations is the precession method of X-ray diffraction analysis (the determination of the spatial arrangement of atoms in crystals by observing the pattern in which they scatter a beam of X rays), one of the two most commonly used methods of recording diffraction intensities.

water purification: Pretreatment: Prechlorination, which is often the final step of pretreatment and a standard practice in many parts of the world, has been questioned by scientists. During the prechlorination process, chlorine is applied to raw water that may contain high concentrations of natural organic matter. This organic…

Molière: Early life and beginnings in theater: …play, Les Précieuses ridicules (The Affected Young Ladies), prefigured what was to come. It centers on two provincial young women who are exposed by valets masquerading as masters in scenes that contrast, on the one hand, the women’s desire for elegance coupled with a lack of common sense and,…

hospital: History of hospitals: …1639 at Quebec city, the Hôtel-Dieu du Précieux Sang, which is still in operation (as the Hôtel-Dieu de Québec), although not at its original location. In 1644 Jeanne Mance, a French noblewoman, built a hospital of ax-hewn logs on the island of Montreal; this was the beginning of the Hôtel-Dieu…

preciosity, style of thought and expression exhibiting delicacy of taste and sentiment, prevalent in the 17th-century French salons. Initially a reaction against the coarse behaviour and speech of the aristocracy, this spirit of refinement and bon ton was first instituted by the Marquise de

preciosity, style of thought and expression exhibiting delicacy of taste and sentiment, prevalent in the 17th-century French salons. Initially a reaction against the coarse behaviour and speech of the aristocracy, this spirit of refinement and bon ton was first instituted by the Marquise de

Sapphire: Push was filmed as Precious: Based on the Novel ‘Push’ by Sapphire (2009).

Precious Bane, novel by Mary Webb, published in 1924. The story is set in the wild countryside near the Welsh border and is narrated by Prudence Sarn, a young woman whose life has been disrupted by her physical deformity, a cleft lip. Prudence’s defect forces her to develop an inner strength that

cymophane, variety of the gemstone chrysoberyl

cnidarian: Annotated classification: Worldwide; includes precious red coral, Corallium. Order Trachylina Medusa dominant; reduced or no polyp stage. Statocysts and special sensory structures (tentaculocysts). Differ from other hydromedusae by having tentacles inserted above umbrellar margin. Oceanic, mostly warmer waters. Suborder Laingiomedusae Medusae with

almandine, either of two semiprecious gemstones: a violet-coloured variety of ruby spinel (q.v.) or iron aluminum garnet, which is most abundant of the garnets. Specimens of the garnet, frequently crystals, contain up to 25 percent grossular or andradite and are commonly brownish red; gem-quality

Asia: Precious metals: Many Asian countries have produced gold from alluvial stream deposits in past centuries, and some have continued to do so. Small volumes of alluvial gold are produced in Myanmar, Cambodia, and Indonesia, and the headwaters of the Yangtze River in the Tibetan border…

peridot, gem-quality, transparent green olivine in the forsterite–fayalite series (q.v.). Gem-quality olivine has been valued for centuries; the deposit on Jazīrat Zabarjad (Saint Johns Island), Egypt, in the Red Sea that is mentioned by Pliny in his Natural History (ad 70) still produces fine

cnidarian: Annotated classification: Worldwide; includes precious red coral, Corallium. Order Trachylina Medusa dominant; reduced or no polyp stage. Statocysts and special sensory structures (tentaculocysts). Differ from other hydromedusae by having tentacles inserted above umbrellar margin. Oceanic, mostly warmer waters. Suborder Laingiomedusae Medusae with

Sapphire: Push was filmed as Precious: Based on the Novel ‘Push’ by Sapphire (2009).

crystal: Crystal defects: These inclusions are called precipitates and constitute a large defect.

chemical precipitation, formation of a separable solid substance from a solution, either by converting the substance into an insoluble form or by changing the composition of the solvent to diminish the solubility of the substance in it. The distinction between precipitation and crystallization lies

precipitation, all liquid and solid water particles that fall from clouds and reach the ground. These particles include drizzle, rain, snow, snow pellets, ice crystals, and hail. (This article contains a brief treatment of precipitation. For more-extensive coverage, see climate: Precipitation.) The

metallurgy: Increasing strength: …on the same scale as precipitation hardening can be created by plastically deforming the metal at room temperature. This is often done in a cold-working operation such as rolling, forging, or drawing. The deformation occurs through the generation and motion of line defects, called dislocations, on slip planes spaced only…

metallurgy: Hardening treatments: Aging is done at an elevated temperature that is still well below the temperature at which the precipitate will dissolve. If the alloy is heated still further, the precipitate will coarsen; that is, the finest particles will dissolve so that the average particle size will…

sample preparation: Isolation and preconcentration: …isolating the analyte is the precipitation reaction, which requires the formation of a low-solubility, easily filterable product. Complete precipitation of the analyte may require the addition of a “carrier” species that “co-precipitates” with the analyte under the same reaction conditions. The carrier is chosen to have no effect in subsequent…

titration: Precipitation titrations may be illustrated by the example of the determination of chloride content of a sample by titration with silver nitrate, which precipitates the chloride in the form of silver chloride. The presence of the first slight excess of silver ion (i.e., the end…

chemical precipitation, formation of a separable solid substance from a solution, either by converting the substance into an insoluble form or by changing the composition of the solvent to diminish the solubility of the substance in it. The distinction between precipitation and crystallization lies

stainless steel: Precipitation-hardening stainless steel is characterized by its strength, which stems from the addition of aluminum, copper, and niobium to the alloy in amounts less than 0.5 percent of the alloy’s total mass. It is comparable to austenitic stainless steel with respect to its corrosion resistance,…

Southwest National Park: …Davey Foreshore Preserve and the Precipitous Bluff were both added to it. In 1981 it was enlarged again, with lands about the headwaters of the Davey River, and in 1990 it subsumed Mount Bowes and areas along the Upper Weld River.

Henri, baron de Jomini: …l’art de la guerre (1838; Summary of the Art of War, 1868). In 1854 he served as adviser to Tsar Nicholas on tactics during the Crimean War and in 1859 advised Emperor Napoleon III on the Italian expedition.

Géographie Universelle: …universal geography was Conrad Malte-Brun’s Précis de la Géographie Universelle published between 1810 and 1829. A second geography, the profusely illustrated Nouvelle Géographie Universelle by Elisée Réclus, comprised 19 volumes that were published between 1876 and 1894. Réclus’s effort was largely successful and has been called the “greatest individual writing…

Pierre-André Latreille: Publication of his Précis des caractères génériques des insectes disposés dans un ordre naturel (1796; “Summary of the Generic Characteristics of Insects, Arranged in a Natural Order”) marked the beginnings of modern entomology, the scientific study of insects. It also brought him the position of head of the…

precision, reference to how close a set of repeated measurements are to one another. Precision is frequently distinguished from accuracy, which is a reference to how close a measurement is to an actual value. Precision can range from very low to very high. In the case of low precision, the values

precision and recall, performance metrics used to evaluate the effectiveness of certain machine-learning processes. Precision measures the proportion of positive identifications, or “hits,” that were actually correct, and recall measures the proportion of the actual positive values that were

airport: Navigational aids: … (VASIS) and the more modern precision approach path indicator (PAPI). Both work on the principle of guiding lights that show white when the pilot is above the proper glide slope and red when below.

GPS: Augmentation: …equipment with great accuracy, making precision farming a common term in agriculture.

figure skating: Synchronized team skating: Synchronized team skating, also known as precision skating, is the newest and fastest-growing skating sport. It consists of a team of 8 or more skaters (in the United States) or 12 or more skaters (in Canada) who perform various movements, which are…

rocket and missile system: Maneuverable warheads: Another technology, precision-guided warheads, or PGRVs, would actively seek a target, then, using flight controls, actually “fly out” reentry errors. This could yield such accuracy that nuclear warheads could be replaced by conventional explosives.

Precisionism, smooth, sharply defined painting style used by several American artists in representational canvases executed primarily during the 1920s. While Precisionism can be seen as a tendency present in American art since the colonial period, the style of 20th-century Precisionist painters had

voter suppression: …states) obtain prior approval (“preclearance”) of any change to their electoral laws or procedures—generally by demonstrating to a federal court that the change “does not have the purpose and will not have the effect of denying or abridging the right to vote on account of race or color.” Section…

translational medicine, area of research that aims to improve human health and longevity by determining the relevance to human disease of novel discoveries in the biological sciences. Translational medicine seeks to coordinate the use of new knowledge in clinical practice and to incorporate

mammal: Implantation, gestation, and birth: …move about at once (precocial), or they may be blind, hairless, and essentially helpless (altricial). In general, precocial young are born after a relatively long gestation period and in a small litter. Hares and many large grazing mammals bear precocial offspring. Rabbits, carnivores, and most rodents bear altricial young.

precocious puberty: Precocious puberty in girls: Precocious pseudopuberty is partial pubertal development that results from autonomous (gonadotropin-independent) production of estrogen in prepubertal girls. Affected girls have premature development of their breasts and pubic hair, experience rapid growth, and may have irregular vaginal bleeding (due to the stimulatory effects of estrogen alone…

precocious puberty, abnormally early onset of human sexual development. In girls, precocious puberty is defined as the onset of menstruation before age 8, and in boys it is defined as sexual development before age 9. True precocious puberty is characterized by normal pubertal development at an

precognition, supernormal knowledge of future events, with emphasis not upon mentally causing events to occur but upon predicting those the occurrence of which the subject claims has already been determined. Like telepathy and clairvoyance, precognition is said to operate without recourse to the

decarbonization: Industrial carbon removal: …place, some industries engage in precombustion capture, which involves removing CO2 from a fuel, such as coal or natural gas, before the combustion is complete by adding pressure, heat, or chemicals that separate some amount of carbon from the fuel. Postcombustion carbon capture, however, uses solvents in combination with pollution-control…

diesel engine: Diesel combustion: …high pressure either into a precombustion chamber or directly into the piston-cylinder combustion chamber. With the exception of small, high-speed systems, diesel engines use direct injection.

preconception testing, any of several screening and diagnostic procedures that provide information about the health of individuals who are planning to conceive a child. Using careful review of family histories of both parents and DNA testing for many different gene mutations, preconception testing

unconscious: …brought to awareness is a preconscious activity; for example, one may not be thinking (conscious) of his address but readily recalls it when asked. Data that cannot be recalled with effort at a specific time but that later may be remembered are retained on an unconscious level. For example, under…

Liturgy of the Preconsecrated Offerings, a communion service used during Lent in Eastern Orthodox and Eastern-rite Catholic churches; the consecration is omitted, and bread and wine reserved from the previous Sunday’s liturgy are distributed to the faithful. The Liturgy of the Preconsecrated

human behaviour: A moral sense: …the early level, that of preconventional moral reasoning, the child uses external and physical events (such as pleasure or pain) as the source for decisions about moral rightness or wrongness; his standards are based strictly on what will avoid punishment or bring pleasure. At the intermediate level, that of conventional…

fruit processing: Storage: Precooling can be accomplished by hydrocooling (immersion of the fruit in cold water) or vacuum cooling (moistening and then placing under vacuum in order to induce evaporative cooling).

blood cell formation: Precursor cells are stem cells that have developed to the stage where they are committed to forming a particular kind of new blood cell.