1. Sony Computer Science Laboratories, Inc., Tokyo, Japan
2. Systems Biology Institute, Tokyo, Japan
3. Keio University, Tokyo, Japan
4. Medicala Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
5. ERATO-SORST Kitano Symbiotic Systems Project, Japan Science and Technology Agency, Tokyo, Japan
6. Anesthesiology Department, Emory University, Atlanta, Georgia
7. Control and Dynamical Systems, California Institute of Technology, Pasadena, California