Amazon rubber boom the expansion of Iquitos in Peru. The rubber boom occurred largely between 1879 and 1912. There was heightened rubber production and associated activities from 1942 to 1945 during the Second World War. Natural rubber is an elastomer, also known as tree gum, India rubber, and "caoutchouc," which comes from the rubber tree in tropical regions. Christopher Columbus was the one of the first Europeans to bring news of this odd substance back to Europe, but he was not the only one to report it. Around 1736, a French astronomer recalled how Amerindians used rubber to waterproof shoes and cloaks. He
Type A and Type B personality theory among subjects displaying a type A behavior pattern. Type A subjects are more sensitive to stress and produce more catecholamines than type B subjects. This, in turn, seems to induce an intracellular Mg loss. In the long run, type A individuals would develop a state of Mg deficiency, which may promote a greater sensitivity to stress and, ultimately, lead to the development of cardiovascular problems. In a 1998 study done by Ball et al., they looked at differences in Type A and Type B personalities based on substance use. Their results showed that Type B personalities had more severe issues