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 reached its peak in the late 1960s, when it was at 2%. growth rate is currently declining and is projected to continue to decline in the coming years. average annual population change is currently estimated at over 80 million. world population will reach 10 billion persons in the year 2056.