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magnitude

(Encyclopedia)magnitude, in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. a.d.), all visible with the unaided eye, were ranked on a brightness sc...

Free-Soil party

(Encyclopedia)Free-Soil party, in U.S. history, political party that came into existence in 1847–48 chiefly because of rising opposition to the extension of slavery into any of the territories newly acquired from...

digital radio

(Encyclopedia)digital radio, audio broadcasting in which an analog audio signal is converted into a digital signal before being transmitted; also known as digital audio broadcasting (DAB) and high-definition radio....

Dutch West India Company

(Encyclopedia)Dutch West India Company, trading and colonizing company, chartered by the States-General of the Dutch republic in 1621 and organized in 1623. Through its agency New Netherland was founded. The phenom...

probiotic

(Encyclopedia)probiotic, live microorganism administered to a host with the intention of providing a health benefit, or a food, supplement, or treatment containing such microorganisms. Many of the microbes found in...

autoimmune disease

(Encyclopedia)autoimmune disease, any of a number of abnormal conditions caused when the body produces antibodies to its own substances. In rheumatoid arthritis, a group of antibody molecules called collectively RF...

ophthalmology

(Encyclopedia)ophthalmology ŏfˌthălmŏlˈəjē [key], branch of medicine specializing in the anatomy, function and diseases of the eye. Ophthalmologists specialize in the medical and surgical treatment of eye di...

wind chill

(Encyclopedia)wind chill, the cooling effect of wind and temperature combined, expressed in terms of the effect produced by a lower, windless temperature, also called wind chill factor, wind chill temperature, wind...

Stanton, Elizabeth Cady

(Encyclopedia)Stanton, Elizabeth Cady, 1815–1902, American reformer, a leader of the woman-suffrage movement, b. Johnstown, N.Y. She was educated at the Troy Female Seminary (now Emma Willard School) in Troy, N.Y...

birth

(Encyclopedia)birth or labor, delivery of the fetus by the viviparous mammal. Birth is also known as parturition. Human birth normally occurs about 280 days after onset of the last menstrual period before conceptio...