(IMAGE) Universitat Pompeu Fabra - Barcelona Caption Marta Sanvicente, Guillermo Nevot and Nastassia Knödlseder, three of the authors. Credit UPF Usage Restrictions No restrictions. License CC0 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.