In medicine, there are four levels of care: primary, secondary, tertiary, and quaternary. The levels of care refer to the complexity of the medical cases that healthcare providers treat and the skills ...

On October 8, the American College of Emergency Physicians more officially joined the ranks of several other medical organizations, including the American Medical Association as well as the American ...

All industry is part of a chain that starts with primary industry: the production or extraction of raw materials, like agricultural products or mining; and secondary industry: the processing of these ...

For certain countries the availability of the technology and know-how has turned the nuclear weapons option, as well as the possession of chemical and bacteriological weapons, into a threatened ...