Sarah Stewart (cancer researcher) at the age of 39. Stewart returned to the NIH in 1951, joining the National Cancer Institute (NCI), and eventually becoming medical director. Stewart developed an interest in researching viral links to cancer in light of the pioneering research of Jonas Salk in developing a vaccine for the virus which caused polio. Stewart developed an interest in researching viral links to cancer in light of the pioneering research of Jonas Salk in developing a vaccine for the virus which caused polio. Stewart is credited with discovering the Polyomavirus in 1953. She and research partner, Dr. Bernice E. Eddy, were successful
Salk of soldiers (fire and maneuver team) forming a fireteam. Salk A salk () is a small military unit led by a senior soldier that is subordinate to an infantry squad. "Salk" is bigger than a lahingpaar ("fire and maneuver team") but smaller than a jagu ("squad"). It is also one of the smallest military formation among the Estonian Ground Force infantry units. It usually consists of three to five soldiers, and may be further subdivided into fire and maneuver teams. A "salk" is composed of two fire and maneuver teams of two soldiers each, as well as a fireteam leader