Beatrice Melin, Umeå University (IMAGE) Umea University Caption Beatrice Melin, researcher at the Department of Radiation Sciences at Umeå University and one of the article co-authors. Credit Umeå University Usage Restrictions This photo may only be used in contexts related to this news release. 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.