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toxoplasmosis

(Encyclopedia)toxoplasmosis, infection caused by Toxoplasma gondii, a single-celled parasitic microorganism that can infect most warm-blooded animals but reproduces only in animals of the cat family, who shed the p...

Pleiades, in astronomy

(Encyclopedia)Pleiades plēˈədēz, plīˈ– [key], in astronomy, famous open star cluster in the constellation Taurus; cataloged as M45. The cluster consists of some 500 stars, has a diameter of 35 light-years, ...

Hammurabi

(Encyclopedia)Hammurabi hämo͝oräˈbē [key], fl. 1792–1750 b.c., king of Babylonia. He founded an empire that was eventually destroyed by raids from Asia Minor. Hammurabi may have begun building the tower of B...

sewing machine

(Encyclopedia)sewing machine, device that stitches cloth and other materials. An attempt at mechanical sewing was made in England (1790) with a machine having a forked, automatic needle that made a single-thread ch...

macular degeneration

(Encyclopedia)macular degeneration, eye disorder causing loss of central vision. The affected area, the macula, lies at the back of the retina and is the part that produces the sharpest vision. The most serious vis...

human chorionic gonadotropin

(Encyclopedia)human chorionic gonadotropin (HCG): see gonadotropic hormone. ...

human-factors engineering

(Encyclopedia)human-factors engineering: see ergonomics. ...

Human Genome Project

(Encyclopedia)Human Genome Project, international scientific effort to map all of the genes on the 23 pairs of human chromosomes and, to sequence the 3.1 billion DNA base pairs that make up the chromosomes (see nuc...