About the Authors
Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
The authors have declared that no competing interests exist.
Conceived and designed the experiments: HN MF AY HM. Performed the experiments: MF AY HM. Analyzed the data: HN MF AY HM. Wrote the paper: HN. Organized the research project: HN.