Introduction. Beta-blockers, also known as beta-adrenoceptor blocking agents, are medications used to treat conditions such as angina, heart failure and high blood pressure. They decrease the activity of the heart by blocking the action of hormones like adrenaline.
1 The concept of âdemographic changeâ describes a populationâs age structure adjusting to. changes in living conditions. Consequently, changes in thcomposition of a societyâe s age. structure are the result of social shifts. (. 2  cf. . 3  theory of first and second demographic transition.
Here is a summary of World Population Growth history from 10,000 B.C. to the present (2012), and projected world population growth from the present (2012) to 2050 A.D. . lived has been estimated at 110 billion. are alive today (~7 billion).