PASADENA, California, July 5 -- The California Institute of Technology issued the following news: Mayday! SOS! Distress signals like these are used around the world to indicate an emergency. The cells that make up your body also have their own versions of emergency signals. These get activated if a cell is infected by a virus or bacteria, or if there is a lack of important building blocks like amino acids, for example. A new Caltech study identifies how these cellular "stress pathways" activat  more