Pollutants, present in soil, which exhibit radioactivity.

Philosophic formulations which are basic to psychoanalysis. Some of the conceptual theories developed were of the libido, repression, regression, transference, id, ego, superego, Oedipus Complex, etc.

The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.

Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.