1. Department of Astronomy, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts.
2. Howard Hughes Medical Institute, Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts.
3. School of Chemistry, University of New South Wales, Sydney, Australia.
4. SCOL Postdoctoral Fellow, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.