The terrorist attacks of September 11, 2001 have resulted in dramatic changes in aviation security. As of early 2003, an estimated 1,100 explosive detection systems (EDS) and 6,000 explosive trace detection machines (ETD) have been deployed to ensure 100% checked baggage screening at all...

Vaccination is one of the most important and successful public health endeavors in human history, profoundly reducing mortalities caused by infectious diseases. In the United States, the comprehensive success of large scale pediatric immunization programs results from the collaboration of an...