1. Laboratory for Earth and Environmental Sciences, Brookhaven National Laboratory, Upton, New York 11973-5000
2. Consortium for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637
3. Albert Einstein College of Medicine, Bronx, New York 10461
4. Petroleum Engineering Department, University of Oklahoma, Norman, Oklahoma 73017
5. School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019