For PBS NewsHour, Miles O'Brien reports on whether there are ever instances in which the scientific value of research should offset the moral cost of working with chimpanzees. The US government has moved to limit some of the research it funds with chimps in recent months. Medical experiments on chimps can be invasive: one animal may endure dozens of injections, blood samples and liver biopsies in her lifetime. But some scientists argue that this is the only way to advance medicine. MP3 and transcript here, along with video.