Department of Statistics, Iowa State University.|Department of Statistics, Iowa State University, Department of Veterinary Diagnostic and Production Animal Medicine and.|Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50010, USA.|Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50010, USA.|Department of Statistics, Iowa State University.