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.
After a small rise in the next decade, the decade of the Great Depression gave America its lowest decadal increase ever at 7.2%. Henry A. Wallace wrote in his book New Frontiers in 1934, that the end of population growth in the United States as in sight. Today, immigration is mostly shut out. Our birthrate is decreasing. It appears that by 1950 our population will probably reach its peak, around a hundred and fifty million people, and then start declining.. Wallace was correct about the 1950 census, but otherwise missed the trend. In the postwar period, the Baby Boom reversed the decline.