1. Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa 252-0882, Japan
2. Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
3. Faculty of Environment and Information Studies, Keio University, Fujisawa, Kanagawa 252-0882, Japan