1 Leaf shutters are usually fitted within a lens assembly (central shutter), or more rarely immediately behind (behind-the-lens shutter) or, even more rarely, in front of a lens, and shut off the beam of light where it is narrow. 2  Focal-plane shutters are mounted near the focal plane and move to uncover the film or sensor.
DHEA levels begin to naturally decline by the age of 30. While normal levels for women in their 20s fall between 65 and 380 Âµg/dL, for women in their 30s and 40s, the average normal range is 45 to 270 and 32 to 240 Âµg/dL, respectively.
While DHEA may raise testosterone levels in women, who very efficiently convert it to testosterone, this does not appear to be true for men. Scientists at the University of California, San Diego, performed a study on 13 men and 17 women, ranging from 40â70 years of age.