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.
Answer Wiki. Most people don't realize that the Soviet Union shot down numerous US Aircraft during the Cold War. During the Korean War, Soviet pilots flew Migs in combat against American forces. US aircraft conducted ongoing recon missions, and tickled Soviet air defense systems throughout the 50's onward. Those recon and patrol aircraft were, on occasion, shot down.