Recently, Northwest Public Radio aired a profile about a family dairy as part of a series on the Northwest economy.It resulted in a flurry of comments from representatives of the dairy industry, and it spurred questions about the practices of pasteurization and homogenization. Mary Hawkins took the opportunity to speak with leading dairy expert, Stephanie Clark.Formerly with Washington State University, Dr. Clark is now an associate professor at Iowa State University, specializing in food science with a focus on dairy foods.