2,206 research outputs found

    The Attitude of Virginia Leaders Toward Slavery and Secession, Part II

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    The Attitude of Virginia Leaders Toward Slavery and Secession, Part I

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    Religiosity and Sexual Risk Behaviors Among Latina Adolescents: Trends from 1995 to 2008

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    Purpose: The purpose of this study was to determine trends in the influence of religiosity on sexual activity of Latina adolescents in the United States from 1995 to 2008 and to determine if differences existed between the Mexican American and other Latina groups. Methods: The sample comprised the subset of unmarried, 15–21-year-old (mean 17 years) Latina female respondents in the 1995 (n=267), 2002 (n=306), and 2006–2008 (n=400) National Survey of Family Growth (NSFG) datasets. Associations between religiosity (importance of religion and service attendance) and history of ever having sex, number of sex partners, and age of sexual debut were investigated. Results: Less than one half of Latinas in 1995 (44%) and in 2006–2008 (44%) reported that religion was very important to them, whereas in 2002, 50% reported it was important. Only in 1995 did Latinas who viewed religion as very important have a significantly lower level of sexual initiation. In 1995 and in 2006–2008, Latinas who held religion as very important had significantly fewer partners. In all three cohorts, the higher religious importance group had higher virgin survival rates. Across cohorts, approximately one third of respondents reported frequent religious attendance. In all cohorts, frequent attenders were less likely to have had sex, had fewer partners, and had older age at sexual debut. The survival rate as virgins for Mexican origin Latinas was higher in 1995 and 2002 compared to non-Mexican Latinas but was almost the same in 2006–2008. Conclusions: Religiosity had a protective association with sexual activity among Latina adolescents. The association of importance of religion with sexual activity has diminished from 1995 to 2008, however, whereas the importance of service attendance has remained stable. The influence of religion was more apparent among the Latinas of Mexican origin, but this greater influence also diminished by 2006–2008

    Hydro-economic modeling with aquifer-river interactions to guide sustainable basin management

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    Policymakers in arid and semiarid basins face hard choices on water policies needed for adaptation to climate change. Hydro-economic modeling is a state-of-the art approach that can be used to guide the design and implementation of these policies in basins. A major gap in developments of hydro-economic modeling to date has been the weak integration of physically-based representations of water sources and uses such as the interaction between ground and surface water resources, to inform complex basin scale policy choices. This paper presents an integrated hydro-economic modeling framework to address this gap with application to an important and complex river basin in Spain, the Jucar basin, for the assessment of a range of climate change scenarios and policy choices. Results indicate that in absence of adequate policies protecting water resources and natural ecosystems, water users will strategically deplete reservoirs, aquifers and river flows for short-term adaptation to climate change, disregarding the impacts on the environment and future human activities. These impacts can be addressed by implementing sustainable management policies. However, these policies could have disproportionate costs for some stakeholders groups, and their opposition may undermine attempts at sustainable policy. These tradeoffs among water policy choices are important guides to the design of policies aimed at basin-wide adaptation to climate change

    Hydro-economic modeling of conjunctive ground and surface water use to guide sustainable basin management

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    Water demands for irrigation, urban and environmental uses in arid and semiarid regions continue to grow, while freshwater supplies from surface and groundwater resources are becoming scarce and are expected to decline with climate change. Policymakers in these regions face hard choices on water management and policies. Hydro-economic modeling is the state-of-the art tool that could be used to guide the design and implementation of sustainable water management policies in basins. The strength of hydro-economic modeling lies in its capacity to integrate key biophysical and socio-economic components within a unified framework. A major gap in developments on hydro-economic modeling to date has been the weak integration of surface and groundwater flows, based on the theoretically correct Darcy equations used by the hydrogeological community. The modeling approach taken here is integrated, avoiding the single-tank aquifer assumption, avoiding simplified assumptions on aquifer-river linkages, and bypassing iterations among separate hydrological and economic models. The groundwater flow formulation used in this paper harnesses the standard finite difference expressions for groundwater flow and groundwater-surface water exchange developed in the USGS MODFLOW groundwater model. The methodological contribution to previous modeling efforts is the explicit specification of aquifer-river interactions, important when aquifer systems make a sizable contribution to basin resources. The modeling framework is solved completely, and information among the economic and hydrological components over all periods and locations are jointly and simultaneously determined. This novel framework is applied to the Jucar basin (Spain), which is a good experimental region for an integrated basin scale analysis. The framework is used for assessing the impacts of a range of climate change scenarios and policy choices, especially the hydrologic, land use, and economic outcomes. The modeling framework integrates the multiple dimensions of water resources, allowing scenario results to provide reliable information to guide basin scale climate change adaptation policies. Sustainable water management requires policy analysis based on sound science, integrating the hydrologic, economic and environmental dimensions of basins

    Longitudinally diode-pumped Nd:YAG double-clad planar waveguide laser

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    We report the demonstration of a near-diffraction-limited, compact, diode-end-pumped double-clad planar waveguide Nd:YAG laser. Efficient laser operation was achieved for the three dominant Nd3+ transitions at 1.064µm 0.946µm, and 1.32µm, with TE polarised output powers of 1.33W, 0.57W, and 0.33W for the available output couplers. The output beam from the monolithic plane-plane laser cavity had measured M2 values of 1.0 and 1.8, perpendicular and parallel to the plane of the waveguide respectively

    What’s Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Members’ Offending and Victimization

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    Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male members’ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures females’ and males’ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in members’ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation

    Slow relaxation in the two dimensional electron plasma under the strong magnetic field

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    We study slow relaxation processes in the point vortex model for the two-dimensional pure electron plasma under the strong magnetic field. By numerical simulations, it is shown that, from an initial state, the system undergoes the fast relaxation to a quasi-stationary state, and then goes through the slow relaxation to reach a final state. From analysis of simulation data, we find (i) the time scale of the slow relaxation increases linearly to the number of electrons if it is measured by the unit of the bulk rotation time, (ii) during the slow relaxation process, each electron undergoes an superdiffusive motion, and (iii) the superdiffusive motion can be regarded as the Levy flight, whose step size distribution is of the power law. The time scale that each electron diffuses over the system size turns out to be much shorter than that of the slow relaxation, which suggests that the correlation among the superdiffusive trajectories is important in the slow relaxation process.Comment: 11pages, 19 figures. Submitted to J. Phys. Soc. Jp

    Social Determinants of Community Health Services Utilization among the Users in China: A 4-Year Cross-Sectional Study

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    Background To identify social factors determining the frequency of community health service (CHS) utilization among CHS users in China. Methods Nationwide cross-sectional surveys were conducted in 2008, 2009, 2010, and 2011. A total of 86,116 CHS visitors selected from 35 cities were interviewed. Descriptive analysis and multinomial logistic regression analysis were employed to analyze characteristics of CHS users, frequency of CHS utilization, and the socio-demographic and socio-economic factors influencing frequency of CHS utilization. Results Female and senior CHS clients were more likely to make 3–5 and ≥6 CHS visits (as opposed to 1–2 visits) than male and young clients, respectively. CHS clients with higher education were less frequent users than individuals with primary education or less in 2008 and 2009; in later surveys, CHS clients with higher education were the more frequent users. The association between frequent CHS visits and family income has changed significantly between 2008 and 2011. In 2011, income status did not have a discernible effect on the likelihood of making ≥6 CHS visits, and it only had a slight effect on making 3–5 CHS visits. Conclusion CHS may play an important role in providing primary health care to meet the demands of vulnerable populations in China. Over time, individuals with higher education are increasingly likely to make frequent CHS visits than individuals with primary school education or below. The gap in frequency of CHS utilization among different economic income groups decreased from 2008 to 2011
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