Jaagsiekte sheep retrovirus Jaagsiekte sheep retrovirus Jaagsiekte sheep retrovirus (JSRV) is a betaretrovirus which is the causative agent of a contagious lung cancer in sheep, called ovine pulmonary adenocarcinoma. JSRV is the virus that is the cause of the contagious lung tumors in sheep called ovine pulmonary adenocarcinoma (OPA). The disease has also been called "jaagsiekte", after the Afrikaans words for "chase" ("jaag") and "sickness" ("siekte"), to describe the respiratory distress observed in an animal out of breath from being chased, indicating the breathing difficulty experienced by infected sheep. Transmission of virus is through aerosol spread between sheep. The exogenous infectious form of
Animal rights Linzey at Trinity College, Cambridge, in August 1977. This was followed by Mary Midgley's "Beast And Man: The Roots of Human Nature" (1978), then "Animal Rights–A Symposium" (1979), which included the papers delivered to the Cambridge conference. From 1982 onwards, a series of articles by Tom Regan led to his "The Case for Animal Rights" (1984), in which he argues that nonhuman animals are "subjects-of-a-life", and therefore possessors of moral rights, a work regarded as a key text in animal rights theory. Regan wrote in 2001 that philosophers had written more about animal rights in the previous 20 years than