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991.
Early in the 30-year HIV/AIDS pandemic in Sub-Saharan Africa, epidemiological studies identified formal education attainment as a risk factor: educated Sub-Saharan Africans had a higher risk of contracting HIV/AIDS than their less educated peers. Later demographic research reported that by the mid-1990s the education effect had reversed, and education began to function as a social vaccine. Recent counter-evidence finds a curvilinear pattern, with the association between educational attainment and HIV/AIDS infection changing from positive to negative across the education gradient. To reconcile these inconsistent conclusions, a hypothesis is developed and tested that education at early stages functioned as a risk factor and later functioned (and continues to function) as a social vaccine. We reason that this shift in the direction of the education effect was concurrent with changes in the public health environment in SSA that early on heightened material benefits from educational attainment but later heightened cognitive benefits from schooling. Using the 2003/2004 Demographic Health Surveys from four Sub-Saharan African countries (Cameroon, Ghana, Kenya and Tanzania), we tested this hypothesis (differential effects of schooling) using non-linear regression analysis (probit), identifying the different public health periods and controlling for confounding factors. The results support the hypothesis that the education effect shifted historically in the HIV/AIDS pandemic in SSA as we hypothesized.  相似文献   
992.
993.
The Kidney Exchange Problem (KEP) is a combinatorial optimization problem and has attracted the attention from the community of integer programming/combinatorial optimisation in the past few years. Defined on a directed graph, the KEP has two variations: one concerns cycles only, and the other, cycles as well as chains on the same graph. We call the former a Cardinality Constrained Multi-cycle Problem (CCMcP) and the latter a Cardinality Constrained Cycles and Chains Problem (CCCCP). The cardinality for cycles is restricted in both CCMcP and CCCCP. As for chains, some studies in the literature considered cardinality restrictions, whereas others did not. The CCMcP can be viewed as an Asymmetric Travelling Salesman Problem that does allow subtours, however these subtours are constrained by cardinality, and that it is not necessary to visit all vertices. In existing literature of the KEP, the cardinality constraint for cycles is usually considered to be small (to the best of our knowledge, no more than six). In a CCCCP, each vertex on the directed graph can be included in at most one cycle or chain, but not both. The CCMcP and the CCCCP are interesting and challenging combinatorial optimization problems in their own rights, particularly due to their similarities to some travelling salesman- and vehicle routing-family of problems. In this paper, our main focus is to review the existing mathematical programming models and solution methods in the literature, analyse the performance of these models, and identify future research directions. Further, we propose a polynomial-sized and an exponential-sized mixed-integer linear programming model, discuss a number of stronger constraints for cardinality-infeasible-cycle elimination for the latter, and present some preliminary numerical results.  相似文献   
994.
The thickness of a graph is the minimum number of planar spanning subgraphs into which the graph can be decomposed. It is known for relatively few classes of graphs, compared to other topological invariants, e.g., genus and crossing number. For the complete bipartite graphs, Beineke et al. (Proc Camb Philos Soc 60:1–5, 1964) gave the answer for most graphs in this family in 1964. In this paper, we derive formulas and bounds for the thickness of some complete k-partite graphs. And some properties for the thickness for the join of two graphs are also obtained.  相似文献   
995.
Cognitive bias is prevalent among gamblers, especially those with gambling problems. Grounded in the heuristics theories, this study contributes to the literature by examining a cognitive bias triggered by the break streak pattern in the casino setting. We postulate that gamblers tend to bet on the latest outcome when there is a break-streak pattern. Moreover, three determinants of the betting decision under break-streak pattern, including the streak length of the alternative outcome, the frequency of the latest outcome, and gender, were identified and examined in this study. A non-participatory observational study was conducted among the Cussec gamblers in a casino in Macao. An analysis of 1229 bets confirms our postulation, particularly when the streak of the alternative outcome is long, the latest outcome is frequent, and the gamblers are females. The findings provide meaningful implications for casino management and public policymakers regarding the minimization of gambling harm.  相似文献   
996.
In 2010 France enacted a law to regulate supply and consumption of online gambling. Its primary aim was to protect citizens from gambling-related harm. This study aims to assess differences in gambling patterns and related harm between online gamblers who use licensed versus unlicensed sites. Participants (N = 3860) completed a self-administered online survey on gambling practices. Pairwise logistic regressions examined the association between the legal statuses of gambling sites people patronized and demographic variables and gambling types. Multivariate logistic regression models explored associations between gambling patterns and related problems according to the legal status of sites people have gambled on. Overall, 53.7 % of online gamblers report gambling exclusively on licensed sites. Those who bet on regulated activities on unlicensed sites, versus licensed sites, are more likely to be female, younger, less educated, inactive in the labor market and are more likely to perceive their financial situation to be difficult. Gambling on unlicensed sites is associated with more intense gambling patterns and more gambling-related problems compared to licensed sites. Findings demonstrate that gambling activities carried out on state licensed sites are associated with less overall harm to gamblers. Implications of these findings on future policy are discussed and prospective research directions are outlined.  相似文献   
997.
It is generally difficult to separate the effects of divorce from selection when analyzing the effects of parental divorce on children’s risk behaviors. We used propensity score matching and longitudinal data methods to estimate the effects of parents’ divorce on their children’s binge drinking, alcohol consumption, tobacco use, marijuana use, and hard drug use. The children were between 12 and 18 years old in the first survey and between 18 and 24 years old in the second survey. Our results suggest that parental divorce significantly increased the probability of risk behaviors in their children. Moreover, many of these adverse impacts persisted over time, especially among teenage girls.  相似文献   
998.
This study examined the association of financial access and alternative financial services (AFS) using a nationally representative sample from the 2012 National Financial Capability Study (N = 25,509). Structural equation modeling was used to examine the relationship between financial access and AFS usage. Ordinary least squares regression was used to estimate the relationship between banked status and the overall AFS usage as a latent variable while controlling for sociodemographic variables, financial education, financial knowledge, and home ownership. Results suggested that being unbanked was positively associated with AFS usage after controlling for other covariates. Financial education and knowledge, age, gender, marital status, education, household income, and homeownership were significantly associated with AFS usage. These findings have implications for public policy and programs that work with the unbanked.  相似文献   
999.
Financial education sans opportunities for hands-on experience and knowledge operationalization may be insufficient for promoting healthy financial behaviors. Financial capability combines financial education with financial inclusion via a savings account, thereby giving an opportunity translate knowledge into practice. This study used data from the 2012 National Financial Capability Study to examine relationships between the financial capability and financial behaviors of United States Millennials (N = 6865). Compared to their financially excluded peers, Millennials who were financially capable were 176 % more likely to afford unexpected expenses, 224 % more likely to save for emergencies, 21 % less likely to use alternative financial services, and 30 % less likely to carry burdensome debt. Interventions that focus solely on financial education or inclusion may be insufficient for facilitating Millennials’ healthy financial behaviors; interventions should instead develop financial capability.  相似文献   
1000.
Rates of food insecurity in the US have been rising since 2000 spiking with the onset of the Great Recession in 2008, and have remained essentially unchanged since then despite improvements in the economy. The present study employed a series of indices adapted from the poverty literature to examine the depth and severity of food insecurity across the decade by race and ethnicity among low-income households with and without children. The most rapid increases in the depth and severity of food insecurity were found among low-income households without children. Non-Hispanic White households with and without children had lower prevalence rates but steeper increases in the depth and severity of food insecurity throughout the decade. Non-Hispanic Black households with and without children were at the most disadvantaged among low-income populations.  相似文献   
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