American physician who with J. A. Strong was the first to show that Klinefelter's syndrome was caused by a genetic defect on one of the sex chromosomes. This, along with Turner's syndrome, was among the first diseases to be l...

P. G. Wodehouse was born 15 October 1881 in Guildford, the suburb of London to which Charles Dickens retired Mr. Pickwick, and educated at Dulwich College, one of England's best public schools. After graduating, Wodehouse worked briefly in...

Percival James PattersonPrime Minister (pronounced "PURR-sih-vull JAYMZ PAT-er-son") "Jamaica is ready for the bold march into the new era of a borderless world economy." With an area of 10,990 sq km (4,243...

The Spanish painter, sculptor, and graphic artist Pablo Picasso (1881-1973) was one of the most prodigious and revolutionary artists in the history of Western painting. As the central figure in developing cubism, he established the basis f...

d. 1471 Inca Emperor Pachacutec Inca Yupanqui was not only the first Inca emperor whose dates and existence are firmly established in history; he is also widely considered the greatest Inca ruler—if not one of the greatest leaders i...

PACHOMIUS (293?–346) was a Christian ascetic and founder of cenobitic monasticism. Information about Pachomius has been much confused in the many legends and biographies preserved in various versions and translations. Born of pagan ...

1782-1842 American explorer of the trans-Mississippi West. In 1810-12 Hunt lead a party called the Astorians—named after their sponsor, John Jacob Astor—up the Missouri River and across the continent in an effort to establish...

region, western North America, possessing two unifying geologic and geographic properties—the Pacific Ocean, which constitutes a natural western border, and the coastal mountain ranges that form the eastern border of the region. The ...

Pacifier An artificial nipple designed for infants to suck, and which has a soothing effect. Infants have a strong desire to suck, which may not be entirely fulfilled while feeding. Both the newborn and older infant are often soothed by su...

Packet switching is the process by which data is broken into smaller chunks, or packets, for transmission over a network. Packet switching divides a message into smaller units, sends each unit individually via the best route possible at th...

With the birth of television in the late 1940s came a new medium through which writers could reach varied audiences. Paddy Chayefsky recognized the scope of this medium and produced some remarkable television plays, including Marty (1953) ...

The Padri (or Paderi) War lasted from 1821 to 1837 and arose from a movement among the Minangkabau people of the central western coast of Sumatra both to purify Islamic practice and resist colonial rule. The Minangkabau social structure wa...

Traditional designation of a practitioner of classical polytheisms. The early Christians often used the term to refer to non-Christians who worshiped multiple deities. Christian missionaries frequently sought to stamp out pagan practices b...

Starting in the late 1960s and early 1970s, there arose the problem that software programs and their data would take up more memory space than was available in the primary storage (RAM). It became necessary to think of ways to break up suc...

(2002 est. pop. 1.3 million). Pahang, the largest state in Malaysia, is located in the east coast region. It covers an area of 35,965 square kilometers and has a population of approximately 1.3 million—74 percent Malay, 19 percent C...

The reign of the Pahlavi dynasty (1925–1979) was a crucial and transitional period in Iranian history that began with Reza Shah Pahlavi (1878–1944) and ended with his son, Mohammad Reza Shah Pahlavi (1919–1980). For Ir...

Pain is a sensation unique to an individual. Its perception depends on the injury involved and the situation or context. A bruise obtained in a football game may not be appreciated at the time of the injury, yet in other circumstances the ...

The earliest remaining examples of painting in South Asia are Buddhist cave murals such as those in the monasteries at Ajanta in India. Here, two phases of painting, corresponding to the two phases of active patronage, may be distinguished...

(b. 1926), Korean novelist. Pak Kyung-ri was born in the coastal city of Ch'ungmu in South Kyungsang Province. She started her career as a writer in the mid-1950s, with the publication of such short stories as "Kyesan"...

Country, southern Asia. Area: 307,374 sq mi (796,096 sq km). Population (2005 est.): 153,960,000. Capital: Islamabad. The population is a complex mix of indigenous peoples who have been affected by successive waves of migrations of Aryans,...

Pakistan received its independence from British India in 1947. It was created on the basis of religious identity, so that Muslims from British India, which had an overwhelming majority of followers of the Hindu religion, would have a nati...

Baroque palace southwest of Paris built chiefly under Louis XIV. It was the principal residence of the French kings and the seat of government from 1682 to 1789, with some 1,000 courtiers and 4,000 attendants residing there. Originally a h...

country in the western Pacific Ocean. It consists of some 340 coral and volcanic islands perched on the Kyushu-Palau Ridge. The Palau (also spelled Belau or Pelew) archipelago lies in the southwest corner of Micronesia, with Guam 830 miles...

Paleobotany is the study of plants that lived in prehistoric times. It largely involves the study of fossils, that is, impressions of plant parts that have been preserved in sedimentary rock or coal. The most ancient plant fossils are of m...

Scientific study of the extended climatic conditions of past geologic ages. Paleoclimatologists seek to explain climate variations for all parts of the Earth during any given geologic period, beginning with the time of the Earth's formatio...