Conceptual illustration of the study (IMAGE) Hokkaido University Caption Conceptual illustration of the study Credit Yuki Kimura Usage Restrictions This image is copyrighted but may be used to report on this press release as long as the copyright holder is credited. License Original 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.