1. Department of Mathematical Sciences, Tokyo Denki University, Hatoyama, Saitama 350-0394, Japan.
2. Department of Computing Science, University of Alberta, Edmonton, Alberta T6G 2E8, Canada.
3. Dipartimento di Informatica e Telecomunicazioni, Università di Trento, Italy.
4. Department of Computer Science, University of California, Riverside, CA 92521.
5. Digital Biology Laboratory, Computer Science Department, University of Missouri-Columbia, Columbia, MO 65211-2060.
6. Biochemistry and Molecular Biology Department, and Institute of Bioinformatics, University of Georgia, Athens, GA 30602.
7. Department of Computer Science, University of California, Riverside, CA 92521. Also with Shanghai Center for Bioinformation Technology, Shanghai, China.