Lead author (IMAGE) University of Massachusetts Amherst Caption ChangHui Pak is an assistant professor of biochemistry and molecular biology at the University of Massachusetts Amherst. Credit UMass Amherst Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.