[1] Agilent Labs, Chem & Biol Syst Dept, Palo Alto, CA 94304 USA
[2] Univ Washington, Dept Comp Sci & Engn, Seattle, WA 98195 USA
[3] Univ Calif Berkeley, Int Comp Sci Inst, Berkeley, CA 94704 USA
[4] Inst Syst Biol, Seattle, WA 98105 USA
[5] Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel