Ovine pulmonary adenocarcinoma Ovine pulmonary adenocarcinoma Ovine pulmonary adenocarcinoma (OPA), also known as ovine pulmonary adenomatosis, or jaagsiekte, is a chronic and contagious disease of the lungs of sheep and goats. OPA is caused by a retrovirus called jaagsiekte sheep retrovirus (JSRV). The disease has a long incubation period, and therefore signs usually occur in adult animals (over 2 years of age). Clinical signs resemble a non-specific progressive pneumonia, including poor body condition and, particularly after exercise, respiratory difficulty. Unless a concurrent lung infection is present, affected sheep continue to eat. The only sign specific to OPA is a watery nasal discharge, consisting
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