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.
Population growth rates in nonmetro areas have been significantly lower than in metro areas since the mid-1990s, and the gap widened considerably in recent years. While annual rates of population change in nonmetro areas went from 0.7 percent to below zero between 2006 and 2016, metro rates declined only slightly, from 1 percent to 0.8 percent.