title: What can be done and what is worth doing: thoughts on limits and priorities. Third Shirley A. Johnson memorial lecture.
mesh_terms: D000818:Animals; D001161:Arteriosclerosis; D001695:Biology; D004463:Ecology; D004989:Ethics; D006168:Guinea Pigs; D006405:Hematology; D055585:Physical Phenomena; D010825:Physics; D012106:Research; D012109:Research Support as Topic; D012945:Social Values; D013672:Technology