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
Substance dependence upon which a person has developed a dependence syndrome. When dependence has developed, cessation of substance use produces an unpleasant state, which promotes continued drug use through negative reinforcement; i.e., the drug is used to escape or avoid re-entering the associated withdrawal state. The withdrawal state may include physical-somatic symptoms (physical dependence), emotional-motivational symptoms (psychological dependence), or both. Chemical and hormonal imbalances may arise if the substance is not introduced. Psychological stress may also result if the substance is not re-introduced. Infants also suffer from substance withdrawal, known as Neonnatal Abstinence Syndrome (NAS) which has severe and life-threatening effects on