Some Pittsburgh schools closed for the day over water issue

Insufficient chlorine in Pittsburgh's public water supply led to the closure Wednesday of nearly two dozen grade schools and a boil-water advisory in neighborhoods that include the University of Pittsburgh and Carnegie Mellon ...

Bacteria use traffic-cop-like mechanism to infect gut

A study has found that a syringe-like device used to invade intestinal cells also acts as a traffic cop—directing bacteria where to go and thereby enabling them to efficiently carry out infection.