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.
Bell AH-1 Cobra: Bell AH-1 Cobra is another very advanced helicopter which is made with the single engine and the product of famous helicopter company called Bell helicopters. It is made with latest rotor system and transmission in it. It is considered as the backbone of the USA army because it is quite an advance one.