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.
Other countries have a more pyramidal shape with a wide base, reflecting higher infant mortality and greater risk of early death. [edit] Population growth Main article: Population growth Population growth is change in population over time. It also can be quantified as the change in the number of individuals in a population per unit time.