Visual acuity Visual acuity is one of many visual perception abilities and is defined as the behavioral ability to resolve fine image details. VA is a quantitative measure of the ability to identify black symbols on a white background at a standardized distance as the size of the symbols is varied.
	Visual cortex Visual cortex is the term applied to both the primary visual cortex and upstream visual cortical areas also known as extrastriate cortical areas . The primary visual cortex is anatomically equivalent to Brodmann area 17, or BA17. Brodmann areas are based on a histological map of the human brain created by Korbinian Brodmann.
	Visual field The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspection psychological experiments", while field of view "refers to the physical objects and light sources in the external world that impinge the retina".
	Visual perception Visual perception is the end product of vision, consisting of the ability to detect light and interpret the consequences of light stimuli. The resulting perception is known as eyesight, sight or naked eye vision. Vision has a specific sensory system, the visual system.
	Visual system The visual system is the part of the nervous system which allows organisms to visual perception. It interprets the information from visible light to build a representation of the world surrounding the body. The visual system has the complex task ofconstructing a three dimensional world from a two dimensional projection of that world.
	Vitalism Vitalism, as defined by the Merriam-Webster dictionary, is Where vitalism explictly invokes a vital principle, that element is often referred to as the "vital spark", "energy" or "lan vital", which some equate with the "soul". Vitalism has a long history in medical philosophies: most traditional medicine practices posited that disease was the result of some imbalance in the vital energies which distinguish living from non-living matter.
	Vitality
	Vitamin Vitamins are nutrients required for essential metabolic reactions in the body . Vitamins can act both as catalysts and substrates in chemical reactions. The role of a catalyst is to facilitate a chemical reaction without being altered itself. In essence, catalysts function like knitting needles, which are capable of converting yarn into mittens, but do not undergo any change themselves.
	Vitamin B6 Vitamin B6 is a water-soluble vitamin. The three major forms of vitamin B6 are pyridoxine, pyridoxal, and pyridoxamine, which, in the liver, are converted to pyridoxal 5'-phosphate a cofactor in many reactions of amino acid metabolism. PLP also is necessary for the enzymatic reaction governing the release of glucose from glycogen.
	Vitamin C Vitamin C is a tiene como agua x aca vite)-soluble nutrient and vitamin essential for life and for maintaining optimal health. It is also known by the chemical name of its principal form ascorbic acid. It is used by the body for many purposes.
	Vitamin D Vitamin D is a hormone precursor that contributes to the maintenance of normal levels of calcium and phosphorus in the blood. Vitamin D is not a true vitamin since human skin can create vitamin D in some circumstance; it may be better described as a conditional vitamin.
	Vitamin K Vitamin K denotes a group of 2-methilo-naphthoquinone derivatives. They are human vitamins, lipophilic and therefore hydrophobic . They are needed for the posttranslational modification of certain proteins, mostly required for blood coagulation. Vitamin K2 is normally produced by bacteria in the intestines, and dietary deficiency is extremely rare unless the intestines are heavily damaged.
	Vitelline circulation Vitelline circulation refers to the system of blood flowing from the embryo to the yolk sac and back again. The yolk-sac is situated on the ventral aspect of the embryo; it is lined by entoderm, outside of which is a layer of mesoderm. It is filled with fluid, the vitelline fluid, which possibly may be utilized for the nourishment of the embryo during the earlier stages of its existence.
	Viti Levu Viti Levu is the largest island in the Fiji, the site of the nation's capital, Suva, and home to a large majority of Fiji's population.
	Viticulture Viticulture refers to the cultivation of grapes, often for use in the production of wine. When the grapes are used for winemaking, it is also known as viniculture. It is one branch of the science of horticulture. By practice, viticulture is the science, production and study of grapes which deals with the series of events that occur in the vineyard.
	Vitiligo Vitiligo or leukoderma is a chronic skin disease that causes loss of pigment, resulting in irregular pale patches of skin. The precise etiology of the disease is complex and not fully understood. There is some evidence suggesting it is caused by a combination of auto-immune, genetic and environmental factors.
	Vitis labrusca Vitis labrusca is a species of grape native to the eastern United States. It is the source of many grape cultivars, including Concord grapes. It is characteristic of this vine to have tendrils form on every node of the cane. This is in contrast to the European wine grape Vitis vinifera.
	Vitis vinifera For thousands of years, the fruit and plant of Vitis vinifera, the European grapevine, have been harvested for both medicinal and nutritional value; its history is intimately entwined with the history of wine.
	Vitreous humour Vitreous humour or Vitreous humor is the clear aqueous solution that fills the space between the Lens and the retina of the vertebrate eyeball. The solution is 99% water, but has a gelatinous viscosity two to four times that of water. The remaining solutes include salts, sugars, phagocytes, and a network of collagen fibres.
	Vitrification Vitrification is a process of converting a material into a glass-like amorphous solid which is free of any crystal structure, either by the quick removal or addition of heat, or by mixing with an additive. Solidification of a vitreous solid occurs at the glass transition temperature.
	Vitrine Vitrine: A glass-paneled cabinet or case for displaying articles such as china, objects d'art, or fine merchandise. [French, from vitre, pane of glass, from Old French, glass, window with multiple lights, from Latin vitrum.]
	Vitus Vitus was a Christian saint from Sicily, Italia, Roman Empire. He died as a martyr during the persecution of Christians by co-ruling List of Roman Emperors Diocletian and Maximian in 303. He is counted as one of the Fourteen Holy Helpers of the Roman Catholic Church.
	Vitus Bering Vitus Jonassen Bering was a Denmark-born navigator in the service of the Russian Navy, a captain-komandor known among the Russian sailors as Ivan Ivanovich. He was born in the town of Horsens in Denmark and died at Bering Island, near the Kamchatka Peninsula.
	VIVA VIVA is a private Germany music television channel located in Cologne. It was founded in 1993 by a shareholder group led by Time Warner and headed up initially by Dieter Gorny to compete with MTV, the market leader at the time. Being the first music channel to broadcast in German, VIVA was able to secure a close lead in the ratings for the target audience.
	Vivarium A vivarium is an area, usually enclosed, for keeping and raising animals or plants for observation or research. Often, a portion of the ecosystem for a particular species is simulated on a smaller scale, with controls for environmental conditions. A vivarium may be small enough to sit on a desk or table, such as a terrarium or an aquarium, or may be a very large structure, possibly outdoors.
	Vivien Leigh Vivien Leigh was an English people theater and film Actor. Although her film appearances were relatively few, she won two Academy Awards playing "Southern belles", Scarlett O'Hara in Gone With the Wind and Blanche DuBois in A Streetcar Named Desire , a role she had also played in London's West End of London.
	Viviparous eelpout The viviparous blenny or viviparous eelpout is an eelpout in the family Zoarcidae. It is notable for giving childbirth to live larvae. It is a common soup ingredient in Mediterranean countries. The bones are of greenish colour, due to a harmless pigment. Their skin is slimy and the color is variable.
	Vladimir Horowitz Vladimir Samoylovych Horowitz October 1, 1903 – November 5, 1989) was a Ukrainian-born American european classical music pianist. In his prime he was universally considered the most brilliant supertechnician of his time. His use of colors, technique and the excitement of his playing are thought by many to be unrivalled, and his performances of works as diverse as those of Domenico Scarlatti and Alexander Scriabin were equally legendary.
	Vladimir Lenin Vladimir Ilyich Ulyanov, better known to the world as Vladimir Lenin , was the founder of Russian Communism and the first leader of the Soviet Union.
	Vladimir Nabokov Vladimir Vladimirovich Nabokov was a Russia-United States author. He wrote his first literary works in Russian language, but rose to international prominence as a masterly prose stylist for the novels he composed in English language.
	Vladimir Putin Vladimir Vladimirovich Putin is a Politics of Russia, and the current President of Russia of the Russian Federation. He succeeded Boris Yeltsin on December 31, 1999.
	Vladivostok Vladivostok is the administrative center of Primorsky Krai, Russia, situated close to the Russo-People's Republic of China border and North Korea. It is the home port of the Russian Navy's Pacific Fleet. The city's name means "rule the East" in Russian; in the Chinese language, the city is known as ??? — "Sea Cucumber Marsh".
	Vocal folds The vocal folds, also known popularly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx. They oscillation, modulating the flow of air being expelled from the lungs during phonation. Another name for the airway at the level of the vocal cords is the glottis, and the opening between the cords is called the glottic chink.
	Vocational education Vocational education prepares learners for careers that are traditionally non-academics and directly related to a specific trade, job or vocation, hence the term, in which the learner participates. It is sometimes referred to as technical education, as the learner directly develops expertise in a particular techniques or technology.
	Vodka Vodka is typically a colorless liquor, usually distillation from fermentation cereal but also from other raw materials . The word is a diminutive of the Slavic language word "voda" for "water." Except for various types of flavorings, vodka consists of water and alcohol .
	Voicemail Voicemail (or voice mail, vmail or VMS, sometimes called messagebank) is a centralized system of managing telephone messages for a large group of people. In its simplest form it mimics the functions of an answering machine, uses a standard telephone handset for the user interface, and uses a centralized, computerized system rather than equipment at the individual telephone.
	Voices Voices is a 2006 translation of a 2003 crime novel by Icelandic author Arnaldur Indrišason, another entry in the multi award-winning Detective Erlendur series. It was first published in English in August, 2006. The novel won Sweden's Martin Beck Award for Best Crime Novel.
	Volapuk Volapk is the latest avant-garde band of the French drummer Guigou Chenevier. The core of the band is: * Guigou Chenevier - Drums, Marimba, Voices, Clavier, Sanza * Guillaume Saurel - Flute, Engineer, Violoncello, Mixing * Michel Mandel - Clarinet, Clarinet, Taragat The band takes inspiration from a large number of Eurasian ethnic traditions, from Spain to the Balkans to Mongolia, blending them all together in an amazing mix of rhythm, musicality and humor.
	Volcanic crater Perhaps the most conspicuous part of a volcano is the crater, a basin of a roughly circular form within which occurs a vent from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of vast depth. Very large features of this sort are termed calderas.
	Volcanic rock Volcanic rock is an igneous rock of Volcano origin. Volcanic rocks are usually fine-grained or aphanitic to glassy in texture. They often contain xenolith of other Rock and phenocrysts. Phenocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye.
	Volcano A volcano is a landform on the surface of the Earth where magma from the planet's interior erupts to the surface. Roughly defined, a volcano consists of a magma chamber, volcanic pipe and vents. The magma chamber is where magma from deep within the planet accumulates, while pipes are channels that lead to surface vents, openings in the volcano's surface through which lava is ejected during an eruption.
	Volcanology Volcanology is the study of volcanoes, lava, magma and related geology phenomena. A volcanologist is a person who studies in this field. The term volcanology is derived from the Latin language word Vulcan, the Roman mythology of fire.
	Vole A vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, and smaller ears and eyes.
	Volga River The Volga, widely viewed as the national river of Russia, flows through the western part of the country. It is Europe's longest river, with a length of 1 E6 m, and forms the core of the largest river system in Europe. Some of the largest reservoir s in the world may be found along the river.
	Volgograd Volgograd , geographical renaming Tsaritsyn and Stalingrad is a types of settlements in Russia in and the administrative center of Volgograd Oblast, Russia. It is situated on the west bank of the Volga River.
	Volkhov River Volkhov River, also called Olhava river is a river in Novgorod Oblast and Leningrad Oblast of Russia.
	Volleyball Volleyball is an Olympic Games sport in which two teams separated by a high net use their hands, arms, or other parts of their bodies to hit a ball back and forth over the net. Each team is allowed three hits to get the ball over the net to the other team. A point is scored if the ball hits the ground in the opponents' court, if the opponents commit a fault, or if they fail to return the ball properly.
	Volt The volt is the SI SI derived unit of electric potential difference or electromotive force . It is named in honor of the Italian people physicist Alessandro Volta , who invented the voltaic pile, the first chemical battery .
	Voltage Voltage is the potential difference between two points of an electrical network, expressed in volts . It is a measure of the capacity of an electric field to cause an electric current in an electrical conductor.
	Voltaic pile The Voltaic pile was the first modern electric battery , invented by Alessandro Volta in 1800. Volta demonstrated that when metals and chemicals come into contact with each other they produced an electrical current. In his research, Volta placed together several pairs of alternating copper and zinc discs separated by cloth and soaked the cloth in brine to increase conductivity, and an electrical Current was produced.
	Voltaire Franois-Marie Arouet , better known by the pen name Voltaire, was a France Age of Enlightenment writer, essayist, deism and philosophy. Voltaire was known for his sharp wit, philosophical writings, and defense of civil liberty, including freedom of religion and the right to a fair trial.
	Voltmeter A voltmeter is an instrument used for measuring the voltage between two points in an electric circuit. The voltage can be measured by allowing it to pass a current through a resistance; therefore, a voltmeter can be seen as a very high electrical resistance ammeter. One of the design objectives of the instrument is to disturb the circuit as little as possible and hence the instrument should draw a minimum of electric current to operate.
	Volunteer The term volunteer is contested — there is no one agreed-to definition, and the term is frequently debated. Some say a volunteer is someone who performs or offers to perform service out of his or her own free will, without payment, usually in support of a non-profit organization, mission-based initiative or community.
	Volunteers Volunteers is a 1969 album by United States psychedelic rock band, Jefferson Airplane. It is still considered one of the more controversial albums of all time, mostly relating to anti-war messages in the songs. The original title of the album was supposed to be "Volunteers of America", but pressure from RCA lead to the actual name.
	Volute A volute is a spiral scroll-like ornament that forms the basis of the Ionic order, found in the Capital of the Ionic column. It was later incorporated into Corinthian order and Composite order column capitals. Four are normally to be found on an Ionic capital, eight on Composite capitals and smaller versions on the Corinthian capital.
	Volvariella Mushrooms of the genus Volvariella account for 16% of total production of cultivated mushrooms in the world. Volvariella volvacea, well known as the "paddy straw mushroom," is cultured in rice straw in the Philippines and Southeast Asia. This species also favours wood chip piles.
	Volvariella volvacea Volvariella volvacea is a species of edible mushroom cultivated throughout East Asia and Southeast Asia and used extensively in Asian cuisines. In Chinese language, they are called caogu. They are often available fresh in Asia, but are more frequently found in canned or dried form outside their nations of cultivation.
	Volvox Volvox is one of the best-known genera of green algae and is the most developed in a series of genera that form spherical colonies. Each Volvox is composed of numerous flagellate cells similar to Chlamydomonas, on the order of 1000 in total, interconnected and arranged in a hollow sphere .
	Vomer The vomer is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and touches the sphenoid bone, the ethmoid bone, the left and right palatine bone bones, and the left and right maxillary bone bones.
	Vortex A vortex is a spinning, often turbulence, flow with closed streamlines. The shape of media or mass rotating rapidly around a center forms a vortex. It is a flow involving rotation about an axis.
	Vorticella Vorticella is a genus of protozoa, with over 100 known species. They are stalked inverted bell-shaped ciliates, placed among the peritrichs. Each cell has a separate stalk anchored onto the substrate, which contains a contracile fibril called a myoneme. When stimulated this shortens, causing the stalk to coil like a spring.
	Voter turnout Voter turnout is the percentage of eligible voting who cast a ballot in an election. After increasing for many decades, there has been a trend of decreasing voter turnout in most established democracy since the 1960s. In general, low turnout may be due to disenchantment, apathy, or contentment.
	Votes Votes are people of Votia in Ingria. Their own ethnic name is Vadjalain. The Finno-Ugric languages Votic language spoken by Votes is close to extinction. As a distinct nation, Votes have become practically extinct after Stalinist dispersion to Soviet provinces far away as punishment for alleged disloyalty and cowardice during the war.
	Voting Voting is a method of decision making wherein a group such as a meeting or an electorate attempts to gauge its opinion—usually as a final step following discussions or debates. Alternatives to voting include consensus decision making and betting.
	Voting age The voting age is the minimum legal age at which a person may vote in a Government election.
	Voting machine Voting machines are the total combination of mechanical, electromechanical, or electronic equipment, that is used to define ballots; to cast and count votes; to report or display election results; and to maintain and produce any audit trail information. In addition, a voting system includes the practices and associated documentation used to identify system components and versions of such components; to test the system during its development and maintenance; to maintain records of system errors or defects; to determine specific changes
	Voting system A voting system is a means of choice between a number of options, based on the input of a number of voters. Voting is perhaps best known for its use in elections, where political candidates are selected for public administration. Voting can also be used to award prizes, to select between different plans of action, or by a computer program to determine a solution to a complex problem.
	Voussoir A voussoir is a wedge-shaped element in an arch, a mason's term borrowed in Middle English from French verbs connoting a "turn". Each wedge-shaped voussoir turns aside the thrust of the mass above, transferring it from stone to stone to the final edge, which is horizontal and passes the thrust to the supports.
	Vowel In phonetics, a vowel is a sound in spoken language that is characterized by an open configuration of the vocal tract so that there is no build-up of air pressure above the glottis. This contrasts with consonants, which are characterized by a constriction or closure at one or more points along the vocal tract.
	Voyages Voyages is an Australian travel company operating number of holiday properties in various Australian locations including the Red Centre,Central Highlands, the Kimberley region of Western Australia, Queensland Outback and the Great Barrier Reef.