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.
Confidence votes 162. Normal findings (in mg/dL) are 10 to 20 for adults, 5 to 18 for children and infants, 3 to 12 for newborns, and 21 to 40 for cord blood. In the elderly, the blood urea nitrogen may be slightly higher than the normal adult range. while a maximum limite of a normal range can reach 25 mg/100 ml.n abnormally high blood urea nitrogen (BUN) level may indicate  damage to the kidneys and a decreased ability to properly remove  nitrogenous waste from the blood in your u â¦ rine.