http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. Last winter, government agencies killed one third of Yellowstone National Park's bison herd due to concerns about the possible spread of a livestock disease to cattle that graze in areas around the park. Such drastic measures may be unnecessary, however, according to researchers who have assessed the risk of disease transmission from Yellowstone bison to cattle. http://www.physorg.com/news150991706.html Biology Mon, 12 Jan 2009 14:08:26 EST news150991706