About the Authors

Ryo Oizumi

oizumi@ms.u-tokyo.ac.jp

Affiliation Graduate School of Mathematical Science, University of Tokyo, Tokyo, Japan

Competing Interests

The author has declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: RO. Performed the experiments: RO. Analyzed the data: RO. Contributed reagents/materials/analysis tools: RO. Wrote the paper: RO.