image: The grasping behavior of the "artificial/robotic hand" driven by light irradiation. This material relates to a paper that appeared in the Nov. 6, 2015, issue of Science, published by AAAS. The paper, by E.R. Cook at Columbia University in New York, N.Y., and colleagues was titled, "Old World megadroughts and pluvials during the Common Era." view more
Credit: [Credit: Cook <i>et al.</i> Sci. Adv. 2015;1:e1500561]