In 1954, Dr. Frederick C. Robbins, then chief of pediatrics and contagious diseases at Cleveland Metropolitan General Hospital, was one of three winners of that year's Nobel Prize in medicine. The scientists' work, which led to a vaccine against polio, was performed in human fetal cells.
A worker pours a bucket of pesticide into a machine to be sprayed on almond trees at Del Bosque Farms Inc. in Firebaugh, Calif., on April 6, 2015. California and Washington already have adopted, through state regulation, many of the rules that the EPA now wants to put in place nationwide.
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For several years, a satellite orbiting Mars has seen streaks flowing from Martian mountains during warm periods on the surface. Scientists have now confirmed that water is involved.
NASA/JPL/University of Arizona