The Changing Demographic Profile of the United States

[Excerpt] The United States, the third most populous country globally, accounts for about 4.5% of the world’s population. The U.S. population—currently estimated at 308.7 million persons—has more than doubled since its 1950 level of 152.3 million. More than just being double in size, the population has become qualitatively different from what it was in 1950. As noted by the Population Reference Bureau, “The U.S. is getting bigger, older, and more diverse.” The objective of this report is to highlight some of the demographic changes that have already occurred since 1950 and to illustrate how these and future trends will reshape the nation in the decades to come (through 2050). The United States Is Getting Bigger. U.S. population growth is due to the trends over time in the interplay of increased births, decreased deaths, and increased net immigration. The United States Is Getting Older. Aside from the total size, one of the most important demographic characteristics of a population for public policy is its age and sex structure. This report illustrates how the United States has been in the midst of a profound demographic change: the rapid aging of its population, as reflected by an increasing proportion of persons aged 65 and older, and an increasing median age in the population. The United States Is Becoming More Racially and Ethnically Diverse, reflecting the major influence that immigration has had on both the size and the age structure of the U.S. population. This section considers the changing profile of the five major racial groups in the United States. In addition, trends in the changing ethnic composition of the Hispanic or Latino Origin population are discussed. Although this report will not specifically discuss policy options to address the changing demographic profile, it is important to recognize that the inexorable demographic momentum will have important implications for the economic and social forces that will shape future societal well-being. There is ample reason to believe that the United States will be able to cope with the current and projected demographic changes if policymakers accelerate efforts to address and adapt to the changing population profile as it relates to a number of essential domains, such as work, retirement, and pensions; private wealth and income security; the federal budget and intergenerational equity; health, healthcare, and health spending; and the health and well-being of the aging population. These topics, among others, are discussed briefly in the final section of this report. This report will be updated as needed

Stability analysis of financial contagion due to overlapping portfolios

Common asset holdings are widely believed to have been the primary vector of contagion in the recent financial crisis. We develop a network approach to the amplification of financial contagion due to the combination of overlapping portfolios and leverage, and we show how it can be understood in terms of a generalized branching process. By studying a stylized model we estimate the circumstances under which systemic instabilities are likely to occur as a function of parameters such as leverage, market crowding, diversification, and market impact. Although diversification may be good for individual institutions, it can create dangerous systemic effects, and as a result financial contagion gets worse with too much diversification. Under our model there is a critical threshold for leverage; below it financial networks are always stable, and above it the unstable region grows as leverage increases. The financial system exhibits "robust yet fragile" behavior, with regions of the parameter space where contagion is rare but catastrophic whenever it occurs. Our model and methods of analysis can be calibrated to real data and provide simple yet powerful tools for macroprudential stress testing.Comment: 25 pages, 8 figure

A systematic review of current knowledge of HIV epidemiology and of sexual behaviour in Nepal

OBJECTIVE: To systematically review information on HIV epidemiology and on sexual behaviour in Nepal with a view to identifying gaps in current knowledge. METHODS: Systematic review covering electronic databases, web-based information, personal contact with experts and hand searching of key journals. RESULTS: HIV-1 seroprevalence has been rising rapidly in association with high-risk behaviours, with current levels of 40% amongst the nation's injecting drug users and approaching 20% amongst Kathmandu's female commercial sex workers (FCSWs). HIV seroprevalence remains low in the general population (0.29% of 15–49 year olds). There are significant methodological limitations in many of the seroprevalence studies identified, and these estimates need to be treated with caution. There are extensive migration patterns both within the country and internationally which provide the potential for considerable sexual networking. However, studies of sexual behaviour have focused on FCSWs and the extent of sexual networks within the general population is largely unknown. CONCLUSIONS: Whilst some of the ingredients are present for an explosive HIV epidemic in Nepal, crucial knowledge on sexual behaviour in the general population is missing. Research on sexual networking is urgently required to guide HIV control in Nepal. There is also a need for further good-quality epidemiological studies of HIV seroprevalence

Behaviour of steel end plate bolted beam-to-column joints

This paper presents a numerical investigation into moment-rotation behaviour of extended, flush, and partial depth end-plate joints. Two types of steel beam-to-column joints are modelled: I-beam (IPE) to H-column (HEB) and PFC-beam (UPE) to SHS-column. The joints are designed as a single cantilever beam-to-column joint configuration. The connection details are in accordance with Eurocode 3 part 1-8 and SCI guides P358 (Simple joints) and P398 (Moment joints). Three-dimensional finite element modelling of the joints is car-ried out using ABAQUS. The numerical results are validated against experiments. Both material and geo-metric nonlinearities are considered. All joints are classified according to their stiffness as per Eurocode 3. The failure modes of different joint configurations are determined and compared with the experiments. The key contribution of this paper comes from stiffness analysis of the joints, characterisation of the joints as per EC3 and modelling nonlinear behaviour of the joints

Soil Chemical Properties Under Conservation Agriculture and Cereal-Based Cropping System in Eastern Tarai of Nepal

Field experiments were conducted for four years (2014-2017) at five locations namely Salbani, Bhokraha, Simariya, Bhaluwa and Kaptanganj of Sunsari district to assess the changes in soil chemical properties under conservation agriculture (CA)-based practices in two cropping systems namely rice-kidney bean-maize at Salbani and rice-wheat at rest of the locations. In rice-wheat cropping system, there were four treatments: (1) conventional tillage (CT) for rice transplantation and subsequent wheat sowing, (2) conventional tillage rice transplantation followed by zero tillage (ZT) wheat, (3) unpuddled rice transplantation followed by zero tillage wheat, (4) zero tillage in both rice and wheat. Similarly, in rice-kidney bean-maize cropping system, there were four treatments; (1) conventional tillage for rice transplantation and sowing of both kidney bean and maize, (2) conventional tillage rice transplantation followed by zero tillage in both kidney bean and maize, (3) unpuddled rice transplantation followed by zero tillage in both kidney bean and maize, (4) zero tillage in all three crops. Soil samples were taken at initial and every year after rice harvest.The soil samples were analyzed for total nitrogen, available phosphorus, available potassium, pH and soil organic matter.Total nitrogen (N) showed a slightly decreasing trend in the first three years and showed a slight increase at the end of experiment under ZT in all locations. The total N under ZT changed from 0.12 to 0.13%, 0.05 to 0.06%, 0.10 to 0.12%, 0.11 to 0.08% and 0.09 to 0.13% in Salbani, Bhokraha, Simariya, Bhaluwa and Kaptanganj, respectively.  All locations showed the positive values of available potassium; Salbani  revealing considerable change of 64.3 to 78.5 mg/kg in CT while 68.4 to 73.3 mg/kg in ZT condition. The treatment where rice was transplanted in unpuddled condition and zero tilled to wheat, had a mean value of available phosphorus and potassium as 87.3 and 81.9 mg/kg respectively. Soil pH ranged from 4.8 to 7.1 in CT while it was 5.2 to 6.8 in ZT across the locations. The change in soil organic matter in CT of all locations except Salbani was narrower as compared to ZT

Natural and Synthetic Corticosteroids Inhibit Uptake\u3csub\u3e2\u3c/sub\u3e-Mediated Transport in CNS Neurons

In addition to exerting actions via mineralocorticoid and glucocorticoid receptors, corticosteroids also act by inhibiting uptake2, a high-capacity monoamine transport system originally described in peripheral tissues. Recent studies have demonstrated that uptake2 transporters are expressed in the brain and play roles in monoamine clearance, suggesting that they mediate some corticosteroid effects on physiological and behavioral processes. However, the sensitivity of brain uptake2 to many natural and synthetic corticosteroids has not been characterized. Cultured rat cerebellar granule neurons (CGNs) were previously shown to exhibit corticosterone-sensitive accumulation of the uptake2 substrate1-methyl-4-phenylpyridinium (MPP+). We examined the expression of uptake1 and uptake2 transporters in CGNs, and tested the effects of a variety of natural and synthetic corticosteroids on accumulation of [3H]-MPP+ by these cells. Cultured rat CGNs expressed mRNA for three uptake2-like transporters: organic cation transporters 1 and 3, and the plasma membrane monoamine transporter. They did not express mRNA for the dopamine or norepinephrine transporters, and expressed very little mRNA for the serotonin reuptake transporter. Accumulation of [3H]-MPP+ by CGNs was dose-dependently inhibited by corticosterone and decynium-22, known inhibitors of uptake2. Accumulation of MPP+ was also dose-dependently inhibited, with varying efficacies, by aldosterone, 11-deoxycorticosterone, cortisol, and cortisone, and by the synthetic glucocorticoids betamethasone, dexamethasone and prednisolone, and the glucocorticoid receptor antagonist RU38486. These studies demonstrate that uptake2 in the CNS is inhibited by a variety of natural and synthetic corticosteroids, and suggest that inhibition of uptake2-mediated monoamine clearance may underlie some behavioral and physiological effects of these hormones

Cluster Analysis of Maize Inbred Lines

The determination of diversity among inbred lines is important for heterosis breeding. Sixty maize inbred lines were evaluated for their eight agro morphological traits during winter season of 2011 to analyze their genetic diversity. Clustering was done by average linkage method. The inbred lines were grouped into six clusters. Inbred lines grouped into Clusters II had taller plants with maximum number of leaves. The cluster III was characterized with shorter plants with minimum number of leaves. The inbred lines categorized into cluster V had early flowering whereas the group into cluster VI had late flowering time. The inbred lines grouped into the cluster III were characterized by higher value of anthesis silking interval (ASI) and those of cluster VI had lower value of ASI. These results showed that the inbred lines having widely divergent clusters can be utilized in hybrid breeding programme