1. College of Veterinary Medicine; Gansu Agricultural University; Lanzhou China
2. State Key Laboratory of Veterinary Etiological Biology; National Foot and Mouth Diseases Reference Laboratory; Key Laboratory of Animal Virology of Ministry of Agriculture; Lanzhou Veterinary Research Institute; Chinese Academy of Agricultural Sciences; Lanzhou China
3. Department of Veterinary Population Medicine; College of Veterinary Medicine; University of Minnesota; St. Paul MN USA
4. Health Team; PIC; Hendersonville TN USA