The pyloric sphincter is compose of smooth muscle and is located between the pylorus in the stomach and duodenum of the small intestine. In digestion, it serves as a valve controlling the flow of food thus it prevents the contents of small intestine backing up into the stomach.
Rhinoviruses are transmitted through the air or via contact. We might expect this sort of transmission to require a fairly healthy host (one who gets out and comes into contact with others) and, hence, to select against virulent strains. If we take precautions and try to stay away from people or avoid any contact with people, more hand-washing stations, increased attention to sanitization, and isolation of patients will help to reduce the transmission of the disease and, in the process, may favor the evolution of less virulent strains of the virus.
Eye strain - hope this helped