Columbia Encyclopedia

Search results

500 results found

Crimean-Congo hemorrhagic fever

(Encyclopedia)Crimean-Congo hemorrhagic fever, acute, sometimes fatal disease endemic in many parts of Eurasia and Africa, caused by a tick-borne virus. The virus, an RNA virus (Nairovirus) of the Bunyaviridae fami...

sociolinguistics

(Encyclopedia)sociolinguistics, the study of language as it affects and is affected by social relations. Sociolinguistics encompasses a broad range of concerns, including bilingualism, pidgin and creole languages, ...

poisonous plant

(Encyclopedia)poisonous plant, any plant possessing a property injurious to man or animal. Plants may be poisonous to the touch (e.g., poison ivy, poison sumac), or orally toxic (e.g., poison hemlock, deadly amanit...

reservoir

(Encyclopedia)reservoir rĕzˈəvôr, –vwär [key], storage tank or wholly or partly artificial lake for storing water. Building an embankment or dam to preserve a supply of water for irrigation is an ancient pra...

quarantine

(Encyclopedia)quarantine kwŏrˈəntēn [key], isolation of persons, animals, places, and effects that carry or are suspected of harboring communicable disease. The term originally referred to the 40 days of offsho...

parent and child

(Encyclopedia)parent and child, legal relationship, created by biological (birth) relationship or by adoption, that confers certain rights and duties on parent and child; in some states the courts have given the no...

stroke

(Encyclopedia)stroke, destruction of brain tissue as a result of intracerebral hemorrhage or infarction caused by thrombosis (clotting) or embolus (obstruction in a blood vessel caused by clotted blood or other for...

whooping cough

(Encyclopedia)whooping cough or pertussis, highly communicable infectious disease caused by the bacterium Bordetella pertussis. The early or catarrhal stage of whooping cough is manifested by the usual symptoms of ...

veto

(Encyclopedia)veto [Lat.,=I forbid], power of one functionary (e.g., the president) of a government, or of one member of a group or coalition, to block the operation of laws or agreements passed or entered into by ...

mutation

(Encyclopedia)mutation, in biology, a sudden, random change in a gene, or unit of hereditary material, that can alter an inheritable characteristic. Most mutations are not beneficial, since any change in the delica...