1. Environmentally Integrated Dairy Management Research Unit, USDA Agricultural Research Service, Marshfield, Wisconsin 54449, United States
2. Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
3. Departments of Pathology and Bioengineering, Stanford University, Stanford, California 94305, United States
4. Joint Initiative for Metrology in Biology, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
5. Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
6. Institute for the Environment, University of North Carolina, Chapel Hill, North Carolina 27517, United States