1. Department of Biostatistics, Brown University, Providence, RI;
2. Center for Statistical Sciences, Brown University, Providence, RI;
3. Center for Computational Molecular Biology, Brown University, Providence, RI;
4. Department of Applied Mathematics, Tel Aviv University, Tel Aviv, Israel;
5. Department of Systems Biology, Columbia University, New York, NY;
6. Department of Statistical Science, Duke University, Durham, NC;
7. Department of Computer Science, Duke University, Durham, NC;
8. Department of Mathematics, Duke University, Durham, NC;
9. Department of Bioinformatics & Biostatistics, Duke University, Durham, NC