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.
Growth Rate. Population in the world is currently (2017) growing at a rate of around 1.11% per year (down from 1.13% in 2016). The current average population change is estimated at around 80 million per year. Annual growth rate reached its peak in the late 1960s, when it was at 2% and above.