1. USDA, ARS Foreign Disease Weed Science Research Unit Fort Detrick MD USA
2. AIDS and Cancer Virus Program Leidos Biomedical Research Inc. Frederick National Laboratory for Cancer Research Frederick MD USA
3. Department of Microbiology and Immunology University of Texas Medical Branch Galveston TX USA
4. USDA, ARS Animal Biosciences and Biotechnology Laboratory Beltsville MD USA