“How did it start?” is among the many questions raised by the Covid-19 pandemic. Answering it may help prevent future pandemics. The escape of SARS-CoV-2 from a research laboratory in Wuhan, China, ...

These rules are designed to limit unnecessary radiation exposures and contamination of the facilities and equipment and to minimize the consequences of a radiation accident if it should occur. Copies ...

These rules are designed to limit unnecessary radiation exposures and contamination of the facilities and equipment and to minimize the consequences of a radiation accident if it should occur. Copies ...