Probiotics such as bifidobacteria are typically used in cases when a disease occurs or might occur due to a kill-off of normal bacteria. For example, treatment with antibiotics can destroy disease-causing bacteria, but also normal bacteria in the GI (gastrointestinal) and urinary tracts.
The 3-place Hiller Model 360, military H-23 Raven, was based on the U.S. Navy UH-12, which was first flown in 1948. The H-23 Raven performed as a utility, observation, and MedEvac helicopter during the Korean war.
President Obama's New Marine One Helicopter. President Obama is scheduled to receive a new Marine One helicopter sometime in late 2009. Now seven years into development, the Lockheed Martin VH-71 is outfitted with state-of-the-art defensive measures, secure communications, and crash survivability fuselage design.