This is the first study to use ancient musk oxen DNA collected from across the animal's former geographic range to test for human impacts on musk ox populations, said Penn State Assistant Professor Beth Shapiro, one of the team's leaders. We found that, although human and musk ox populations overlapped in many regions across the globe, humans probably were not responsible for the decline and eventual extinction of musk oxen across much of their former range.

Previous research into how the body communicates with the mind has demonstrated a connection between pessimistic outlook and negative health behaviors.

The fingerprint of human influence has been detected in many different aspects of observed climate changes, Peter Stott, head of climate monitoring at the Hadley Center for Climate Research run by Britain's meteorological office, said in remarks quoted by the Financial Times. Natural variability, from the sun, volcanic eruptions or natural cycles, cannot explain recent warming.

Senior author Deborah Hasin, a professor of clinical epidemiology at the Mailman School of Public Health at Columbia University, and colleagues at the New York state Psychiatric Institute and Harvard University analyzed data from the National Epidemiologic Survey on Alcohol and Related Conditions.

The first bones of the new species -- part of a newly recognized group known as silesaurs -- came from the Triassic Period in Africa and were found in 2007, scientists said.

Belinda Waite, 21, of Bampton, England, said she had been in and out of the hospital for 9 months with problems her doctors attributed to irritable bowel syndrome and gout -- and she was shocked Feb. 6 when doctors told her she was about 3 months pregnant, The Sun reported Wednesday.