Leader self-efficacy in youth leader development: A mixed methods study

Leader self-efficacy (LSE) is a construct studied in adults and college students which is associated with leader emergence, individual performance, and group performance. This mixed methods dissertation examines LSE in an eighth grade student population to determine if it can be impacted by a leader development intervention during this sensitive period of human growth. Both quantitative and qualitative methods demonstrate the effectiveness of the programming in impacting youth LSE. This holds significant implications for future educational practice, research, and the development of the next generation of leaders. A five item youth LSE scale was created which can aid in further research of this construct

Estimating uncertainty of alcohol-attributable fractions for infectious and chronic diseases

Background: Alcohol is a major risk factor for burden of disease and injuries globally. This paper presents a systematic method to compute the 95% confidence intervals of alcohol-attributable fractions (AAFs) with exposure and risk relations stemming from different sources.Methods: The computation was based on previous work done on modelling drinking prevalence using the gamma distribution and the inherent properties of this distribution. The Monte Carlo approach was applied to derive the variance for each AAF by generating random sets of all the parameters. A large number of random samples were thus created for each AAF to estimate variances. The derivation of the distributions of the different parameters is presented as well as sensitivity analyses which give an estimation of the number of samples required to determine the variance with predetermined precision, and to determine which parameter had the most impact on the variance of the AAFs.Results: The analysis of the five Asian regions showed that 150 000 samples gave a sufficiently accurate estimation of the 95% confidence intervals for each disease. The relative risk functions accounted for most of the variance in the majority of cases.Conclusions: Within reasonable computation time, the method yielded very accurate values for variances of AAFs

Study of vibrational excitation mechanisms of CO2 at high temperatures

Calculating vibrational excitation of CO2 for anharmonic coupling and normal mode at high temperatur

Study of vibrational excitation mechanisms of carbon dioxide at high temperatures

Vibrational relaxation models of carbon dioxide at high temperature

Many species risk mountain top extinction long before they reach the top

Analyses of topography show that mountains do not monotonically decrease in area with elevation as is commonly believed and that in reality land area often increases at higher elevations. This finding bodes well for the future of biodiversity since it means that in many parts of the world there are sufficient upslope areas for low- and mid-elevation species to migrate into as temperatures increase. However, more attention needs to be given to determining if migrating species can actually reach these expansive high-elevation areas. Many factors can prevent species from migrating upslope including stable ecotones. Often ecotonal boundaries are not set by mean temperatures alone and thus are not shifting upslope with warming. An example of this are tropical alpine treelines, which are not shifting upslope despite rapid warming potentially due to the stabilizing influences of climatic factors other than mean temperatures (e.g., extreme cold events) or non-climatic factors (e.g., soil or human disturbances). Stable ecotones can potentially prevent species from expanding their ranges into upland areas in which case the amount of land at higher elevations is irrelevant and species may face “mountain top extinctions” long before they reach the actual tops of the mountains

Is there a causal relationship between alcohol and HIV? Implications for policy, practice and future research.

There is now conclusive evidence of a causal linkage between heavy drinking patterns and/or alcohol use disorders and the worsening of the disease course for HIV. However, while alcohol usage is consistently associated with the prevalence and incidence of HIV, further research is needed to substantiate causality in terms of the acquisition of this disease. The burden attributable to alcohol use in South Africa in 2004 has been estimated to be 1.3 million years in terms of years lost though premature death caused by alcohol and years lived with an alcohol-related disability (or just over 6% of all years lost from all causes). Of all years lost through death and disability that can be attributed to alcohol, 10% for men and 28% for women can be directly attributed to alcohol’s impact on the progression of HIV in infected individuals. The implications of the above will be discussed in terms of research gaps that need to be addressed and broader policy responses that are needed in the health and social services sectors. In addition, emphasis will be given to specific practices that should be considered for rollout by agencies involved in substance abuse and HIV/AIDS treatment and prevention. Key Words: Alcohol, HIV and AIDS, South Afric

Low Mach Number Modeling of Type Ia Supernovae

We introduce a low Mach number equation set for the large-scale numerical simulation of carbon-oxygen white dwarfs experiencing a thermonuclear deflagration. Since most of the interesting physics in a Type Ia supernova transpires at Mach numbers from 0.01 to 0.1, such an approach enables both a considerable increase in accuracy and savings in computer time compared with frequently used compressible codes. Our equation set is derived from the fully compressible equations using low Mach number asymptotics, but without any restriction on the size of perturbations in density or temperature. Comparisons with simulations that use the fully compressible equations validate the low Mach number model in regimes where both are applicable. Comparisons to simulations based on the more traditional anelastic approximation also demonstrate the agreement of these models in the regime for which the anelastic approximation is valid. For low Mach number flows with potentially finite amplitude variations in density and temperature, the low Mach number model overcomes the limitations of each of the more traditional models and can serve as the basis for an accurate and efficient simulation tool.Comment: Accepted for publication in the Astrophysical Journal 31 pages, 5 figures (some figures degraded in quality to conserve space

Volume of alcohol consumption, patterns of drinking and burden of disease in sub-Saharan Africa, 2002

The aim of this study was to provide an overview of the volume of alcohol consumption, type of beverage, patterns of drinking and alcohol-attributable burden of disease among adults in sub- Saharan Africa (SSA) for the year 2002. Exposure data were taken from surveys, the World Health Organization (WHO) Global Status Report on Alcohol and the WHO Global Alcohol Database. Mortality and disability data were obtained directly from WHO. The results showed that adult per capita alcohol consumption (population15 years and above) in SSA was higher than the global consumption rate (7.4 L vs. 6.2 L) and that alcohol consumption per adult drinker was 42% higher than the global rate. Alcohol was responsible for a considerable disease burden: 2.2% of all deaths and 2.5% of all DALYs could be attributed to this exposure. Intentional and unintentional injuries accounted for 53% of all alcohol-attributable deaths and almost 57% of alcohol-attributable disease burden. Among men 70% of all alcohol-attributable injury deaths occurred among 15-44 year olds (52% among women). This first attempt to quantify the health burden attributable to alcohol in SSA provides evidence of the direct health costs associated with drinking in the continent. In light of known effective and cost-effective measures, there is urgent need to implement interventions aimed at reducing levels of risky drinking and the high burden of alcohol-related harm in African countries. KEY WORDS: alcohol consumption, patterns of drinking, sub-Saharan Africa, burden of diseas