process of producing immunity and method of vaccination that consists of introduction of the infectious agent onto an abraded or absorptive skin surface instead of inserting the substance in the tissues by means of a hollow needle, as in i...

Viewpoint: Yes, a properly run voluntary system could produce higher vaccination rates while also protecting parents' rights. Viewpoint: No, mandatory vaccinations have greatly reduced the incidence of many diseases and should be ma...

Space in which there is no matter or in which the pressure is so low that any particles in the space do not affect any processes being carried on there. It is a condition well below normal atmospheric pressure and is measured in units of p...

In 1917, just one year after the publication of his general theory of relativity, German American physicist Albert Einstein wrote a short paper titled Cosmological Considerations on the General Theory of Relativity. For the first time the ...

A vacuum is a space completely devoid of matter. A pure vacuum does not exist--even outer space has many particles per cubic meter. In practice one uses a vacuum pump to partially exhaust a space to the highest degree possible, and this pa...

The unsaturated zone is that portion of the subsurface in which the intergranular openings of the geologic medium contain both water and air. The unsaturated zone, also known as the vadose zone or the zone of aeration, extends downward fro...

Vaira Vike-FreibergaPresident (pronounced "VAHY-rah VEE-ke FRAY-behr-guh") "We are the inheritors of our past, but we are not slaves who should live in the shadow of our past. We are the builders of our own future...

Worship of Vishnu as the supreme deity, as well as of his incarnations, mainly Rama and Krishna. Vaishnavism is one of the major forms of modern Hinduism, along with Shaivism and Shaktism, and is probably the most popular and most widely p...

VAJRADHARA (Tib., Rdo rje chang [Dorje chang]; Mongolian, Ochirdana) is, in the last stages of Indian Tantric Buddhism and in the continuing Tibetan traditions, the distinct embodiment of the highest state of being, the primordial Ā...

A major Central Asian river also known as the Kunduz in its lower course, the Surkhob is one of the major tributaries of the Amu Dar'ya (Oxus). The river rises in Afghanistan in the Baba Range of the Hindu Kush and flows for 420 kil...

Valdemar Poulsen was a Danish engineer who invented the magnetic recorder in 1898. His ideas were the basis of magnetic recording and led to crucial developments in communications and computer technology. Born in Copenhagen on November 23,...

1745-1822 French abbot and inventor who is credited with the conception (1771) of an embossed letter system to educate persons with blindness. In 1783-84 Abbot Haüy founded the Institute for the Blind and began training his blind stud...

1629-1683 Irish man who, with what would today be called faith healing, cured many people suffering from psychosomatic illness—illness that originates or is made worse by the patients' belief that they are ill. His ability to...

day (February 14) when lovers express their affection with greetings and gifts. Although there were several Christian martyrs named Valentine, the day probably took its name from a priest who was martyred about &AD; 270 by the emperor Clau...

Valerie Harper was a little-known actress-dancer when she was cast as Rhoda Morgenstern, neighbor and best buddy of Mary Richards, on CBS's landmark 1970s TV sitcom The Mary Tyler Moore Show. Harper emerged as one of television hist...

1939- Russian astronaut who served as flight director of the Salyut-7 and Mir space stations from 1981-89. Ryumin spent a total of 362 days in space, primarily on two missions to the Salyut-6 space station—175 days in 1977 and 185 d...

in Norse mythology, any of a group of maidens who served the god Odin and were sent by him to the battlefields to choose the slain who were worthy of a place in Valhalla. These foreboders of war rode to the battlefield on horses, wearing h...

in the American Revolution, Pennsylvania encampment grounds of the Continental Army under General George Washington from December 19, 1777, to June 19, 1778, a period that marked the triumph of morale and military discipline over severe ha...

VĀLMĪKI. Legendary sage and author of the Hindu epic Rāmāyaṇa, Vālmīki also plays a role in the epic itself. The first book of his Rāmāyaṇa tells the story of the invent...

The concept of value is more complex than it might initially appear. Values can range across personal preferences as indicated by pleasures, desires, wants, and needs to more objective goods such as health, efficiency, progress, truth, bea...

With regards to computing, the term value is a quantity assigned to an element such as a variable, field, symbol, or label. The quantity involving a particular value can refer to (and be assigned to) alphabetic as well as numeric data. Val...

Pluralism is a term used to describe a number of positions from different fields. This entry will confine itself to a discussion of ethical—as opposed to political, social, or metaphysical—pluralism. Ethical pluralism (also ...

in popular legend, a bloodsucking creature, supposedly the restless soul of a heretic, criminal, or suicide, that leaves its burial place at night, often in the form of a bat, to drink the blood of humans. By daybreak it must return to its...

Relatively weak electrical forces that attract neutral (uncharged) molecules to each other in gases, liquefied and solidified gases, and almost all organic liquids and solids. Solids held together by van der Waals forces typically have low...

(born Aug. 31, 1945, Belfast, N.Ire.) Irish singer-songwriter and occasional saxophonist who played in a succession of groups, most notably Them, in the mid-1960s before enjoying a long, varied, and increasingly successful solo career. Mor...