noun, Psychology. 1. Also called operant conditioning, instrumental conditioning. a process of changing behavior by rewarding or punishing a subject each time an action is performed until the subject associates the action with pleasure or distress.
Pertussis is caused by the bacterium Bordetella pertussis. It is an airborne disease which spreads easily through the coughs and sneezes of an infected person. People are infectious to others from the start of symptoms until about three weeks into the coughing fits.
PERTUSSIS FACT SHEET. Pertussis, also called whooping cough, is a very contagious disease of the lungs and airways that has been a common childhood illness for centuries. Pertussis is caused by bacteria that are found in the nose, mouth and throat of an infected person.