The hemoglobin is checked before each donation to. ensure that the donor has adequate red blood cell levels to donate blood. Blood donors must have a minimum of 12.5 g/dL hemoglobin or a hematocrit of 38% to be accepted for donation. The hematocrit is a measure of the volume that red blood cells take up in the blood. Most men have a hemoglobin of 12.5 g/dL or greater and a hematocrit above 38 percent, but many women naturally have lower hemoglobin/hematocrit levels.
Iwo Jima, which means Sulfur Island, was strategically important as an air base for fighter escorts supporting long-range bombing missions against mainland Japan.ecause of the distance between mainland Japan and U.S. bases in the Mariana Islands, the capture of Iwo Jima was necessary to provide an emergency landing strip for crippled B-29s returning from bombing runs.
Introduction. The American amphibious invasion of Iwo Jima during World War II stemmed from the need for a base near the Japanese coast. Following elaborate preparatory air and naval bombardment, three U.S. marine divisions landed on the island in February 1945. Iwo Jima was defended by roughly 23,000 Japanese army and navy troops, who fought from an elaborate network of caves, dugouts, tunnels and underground installations.