Androgens are responsible for the growth spurt of adolescence and for the eventual termination of linear growth, which is brought about by fusion of the epiphyseal growth centers. In children, exogenous androgens accelerate linear growth rates but may cause a disproportionate advancement in bone maturation. Use over long periods may result in fusion of the epiphyseal growth centers and termination of growth process. Androgens have been reported to stimulate the production of red blood cells by enhancing the production of erythropoeitic stimulating factor. During exogenous administration of androgens,Â endogenous testosterone Â release is inhibited through feedback inhibition of pituitary luteinizing hormone (LH).
A method of decreasing wave drag was discovered by German researchers in 1935—sweeping the wing backwards. Today, almost all aircraft designed to fly much above 450 mph (700 km/h) use a swept wing . In the 1970s, Hamilton Standard started researching propellers with similar sweep . Since the inside of the propeller is moving slower than the outside, the blade is progressively more swept toward the outside, leading to a curved shape similar to a scimitar - a practice that was first used as far back as 1909, in the Chauvière make of a two-bladed wood propeller used on the Blériot XI .