Roman World: A historical and cultural entity dispersed across a wide geographical area under the political domination and influence of ancient Rome, bringing to the conquered people the Roman civilization and culture from 753 B.C. to the beginning of the imperial rule under Augustus in 27 B.C. The early city built on seven hills grew to conquer Sicily, Sardinia, Carthage, Gaul, Spain, Britain, Greece, Asia Minor, etc., and extended ultimately from Mesopotamia to the Atlantic. Roman medicine was almost entirely in Greek hands, but Rome, with its superior water system, remains a model of sanitation and hygiene. (From A. Castiglioni, A History of Medicine, 2d ed pp196-99; from F. H. Garrison, An Introduction to the History of Medicine, 4th ed, pp107-120)Holy Roman Empire: Realm in central Europe consisting of a confederation of German and Italian territories under the suzerainty of an emperor and existing from the 9th or 10th century to 1806.Catholicism: The Christian faith, practice, or system of the Catholic Church, specifically the Roman Catholic, the Christian church that is characterized by a hierarchic structure of bishops and priests in which doctrinal and disciplinary authority are dependent upon apostolic succession, with the pope as head of the episcopal college. (From Webster, 3d ed; American Heritage Dictionary, 2d college ed)History, Ancient: The period of history before 500 of the common era.RomeSculptureMortuary Practice: Activities associated with the disposition of the dead. It excludes cultural practices such as funeral rites.Astronauts: Members of spacecraft crew including those who travel in space, and those in training for space flight. (From Webster, 10th ed; Jane's Aerospace Dictionary, 3d ed)Space Flight: Travel beyond the earth's atmosphere.Weightlessness: Condition in which no acceleration, whether due to gravity or any other force, can be detected by an observer within a system. It also means the absence of weight or the absence of the force of gravity acting on a body. Microgravity, gravitational force between 0 and 10 -6 g, is included here. (From NASA Thesaurus, 1988)United States National Aeronautics and Space Administration: An independent Federal agency established in 1958. It conducts research for the solution of problems of flight within and outside the Earth's atmosphere and develops, constructs, tests, and operates aeronautical and space vehicles. (From U.S. Government Manual, 1993)Spacecraft: Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)Puerto Rico: An island in the Greater Antilles in the West Indies. Its capital is San Juan. It is a self-governing commonwealth in union with the United States. It was discovered by Columbus in 1493 but no colonization was attempted until 1508. It belonged to Spain until ceded to the United States in 1898. It became a commonwealth with autonomy in internal affairs in 1952. Columbus named the island San Juan for St. John's Day, the Monday he arrived, and the bay Puerto Rico, rich harbor. The island became Puerto Rico officially in 1932. (From Webster's New Geographical Dictionary, 1988, p987 & Room, Brewer's Dictionary of Names, 1992, p436)ArtChristianity: The religion stemming from the life, teachings, and death of Jesus Christ: the religion that believes in God as the Father Almighty who works redemptively through the Holy Spirit for men's salvation and that affirms Jesus Christ as Lord and Savior who proclaimed to man the gospel of salvation. (From Webster, 3d ed)MuseumsWeight Perception: Recognition and discrimination of the heaviness of a lifted object.United StatesNorth AmericaNaval Medicine: The practice of medicine concerned with conditions affecting the health of individuals associated with the marine environment.South AmericaLatin America: The geographic area of Latin America in general and when the specific country or countries are not indicated. It usually includes Central America, South America, Mexico, and the islands of the Caribbean.France: A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.Rare BooksPaintMediterranean Region: The MEDITERRANEAN SEA, the MEDITERRANEAN ISLANDS, and the countries bordering on the sea collectively.Mosaic Viruses: Viruses which produce a mottled appearance of the leaves of plants.Specific Gravity: The ratio of the density of a material to the density of some standard material, such as water or air, at a specified temperature.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Gravity Sensing: Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).Gravity, Altered: A change in, or manipulation of, gravitational force. This may be a natural or artificial effect.History, 19th Century: Time period from 1801 through 1900 of the common era.Morocco: A country located in north Africa, bordering the Atlantic Ocean and the Mediterranean Sea, with a southern border with Western Sahara, eastern border with Algeria. The capital is Rabat.Gravitation: Acceleration produced by the mutual attraction of two masses, and of magnitude inversely proportional to the square of the distance between the two centers of mass. It is also the force imparted by the earth, moon, or a planet to an object near its surface. (From NASA Thesaurus, 1988)MexicoBrazilReligion: A set of beliefs concerning the nature, cause, and purpose of the universe, especially when considered as the creation of a superhuman agency. It usually involves devotional and ritual observances and often a moral code for the conduct of human affairs. (Random House Collegiate Dictionary, rev. ed.)Population Control: Includes mechanisms or programs which control the numbers of individuals in a population of humans or animals.World Health: The concept pertaining to the health status of inhabitants of the world.Saint Vincent and the Grenadines: A self-governing state of the Windward Islands in the West Indies, comprising Saint Vincent and the northern islets of the Grenadines. Its capital is Kingstown. It is one of the original homes of the Carib Indians supposed to have been sighted by Columbus in 1498. It was in English hands from 1627 till held by the French 1779-83. Saint Vincent subsequently became a British possession and, with other nearby British territories, was administered by the Governor of the Windward Islands till 1959. It attained a measure of independence in 1969 but achieved full independence as Saint Vincent and the Grenadines in 1979. Saint Vincent was the 4th century Spanish martyr on whose feast day Columbus discovered the island. Grenadines is derived from the Spanish kingdom of Granada. (From Webster's New Geographical Dictionary, 1988, p1054 & The Europa World Year Book 1993, p2441)Immunoglobulins, Intravenous: Immunoglobulin preparations used in intravenous infusion, containing primarily IMMUNOGLOBULIN G. They are used to treat a variety of diseases associated with decreased or abnormal immunoglobulin levels including pediatric AIDS; primary HYPERGAMMAGLOBULINEMIA; SCID; CYTOMEGALOVIRUS infections in transplant recipients, LYMPHOCYTIC LEUKEMIA, CHRONIC; Kawasaki syndrome, infection in neonates, and IDIOPATHIC THROMBOCYTOPENIC PURPURA.Aptitude: The ability to acquire general or special types of knowledge or skill.Onions: Herbaceous biennial plants and their edible bulbs, belonging to the Liliaceae.Hypertension, Pulmonary: Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.History of MedicinePolitics: Activities concerned with governmental policies, functions, etc.RestaurantsGarbage: Discarded animal and vegetable matter from a kitchen or the refuse from food preparation. (From Random House College Dictionary, 1982)Famous PersonsMass Media: Instruments or technological means of communication that reach large numbers of people with a common message: press, radio, television, etc.Television: The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)Motion Pictures as Topic: The art, technique, or business of producing motion pictures for entertainment, propaganda, or instruction.