Aeration, Phosphorous, and Lime Affect Nitrogen Mineralization in Imperfectly Drained Forest Soils

Unamended, limed, and phosphorus-enriched Caddo, Beauregard, and Wrightsville silt loams (A1 horizon) were incubated for six months at room temperature under two moisture regimes. At field capacity, unamended soils lost 0.7% of organic matter and converted 166 ppm of organic nitrogen to inorganic forms. Ninety-five percent of the converted nitrogen was present as N₄-H or NO₃-N. Limed and phosphorus-treated soils at field capacity lost about 1.0% of organic matter and accumulated 191 to 201 ppm of inorganic nitrogen. Submerged soils lost very little organic matter and accumulated only 24 to 28 ppm of inorganic nitrogen. There was a loss of 35 to 78 ppm of nitrogen from the submerged soils, presumably through denitrification

Rural African American adolescents and factors affecting condom use: a path analysis study

The purpose of this dissertation was to assess factors affecting condom use among rural African American adolescents. Data from the National Longitudinal Study of Adolescent Health was used to conduct the study. Condom use behavior was examined with a sample of 539 sexually active rural African American adolescents ages 15 to 18 years. The Health Belief Model was used to inform the conceptual framework of this study. Several factors that were associated with condom use among adolescents were examined. These factors included perceived susceptibility to HIV/AIDS and other STIs, perceived barriers to protect self from infections, parent-child sex communication, parental attitudes toward sex communication, and condom knowledge. Path analysis using the structural equation modeling framework was used to assess the models. The results revealed that being female was related to condom knowledge, perceived susceptibility, and parent-child sex communication. Parent-child sex communication mediated the relationship between parental attitudes toward sex communication and perceived barriers. Finally, none of the factors were related to condom use. Several implications for future research with this population are provided. First, other individual-level factors and contextual-level factors that were not measured in this study should be assessed. Second, future studies should include the assessment of parent-child sex communication with fathers and other guardians in addition to mothers. Last, future studies should include sexual minority adolescents, as sex communication about protective behaviors may differ for this population of adolescents

Trends in source gases

Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form

Junior high school students’ use of their afterschool hours in Ghana: The role of household assets

Studies have examined a broad range of factors for how students use their time, but few attempts have been made to explore the nuanced link between different types of asset ownership and students' use of study time, particularly in resource-limited countries. This study uses data from junior high school students in Ghana to examine how students spend their time after school hours, the predictive influence of different types of household assets, and the extent to which these trends and relationships vary by gender. Polynomial quantile regression models were fitted across three quantiles (24th, 53rd, and 76th percentiles) to align with one hour, one and half hours, and two hours of study time. Results show that the average student spends well above the recommended 90 minutes on their schoolwork during afterschool hours, regardless of gender. Multivariate results indicate that owning limited assets tends to have a negative relationship with use of study time, but higher levels tend to be positively related to use of study time. Also, the predictive influence of asset ownership varies by asset type, and higher levels of asset ownership favor girls more than boys. Given this study's realtively small sample size, caution must be exercised in generalizing the study findings to the general population of junior high school students in Ghana. In light of the study's limitations, the finding of varying asset effect may have practical implications for asset development programs designed to enhance the well-being of low-income families

The Effect of Teach One Reach One (TORO) on Youth Acceptance of Couple Violence

This study evaluated the impact of the Teach One Reach One intervention, a community-based participatory research project designed to address the co-occurrence of adolescent risk behaviors on acceptance of teen dating violence. Data were derived from 331 rural African American youth between 10–14 years of age who participated in caregiver-youth dyads as either: 1) peer lay health advisor dyads, or Ambassadors, 2) caregiver-youth dyads recruited by Ambassadors, or Allies, or 3) comparison dyads. The following study focuses on participating youth only and our results indicated that: 1) Ambassadors and Allies reported less acceptance of couple violence than youth within the comparison group, and 2) less family cohesion, greater family conflict, and greater knowledge of healthy dating behaviors predicted greater acceptance of couple violence. Our findings highlight the efficaciousness of the TORO intervention, which directly engaged participants in prevention efforts through community-based participatory research methods and the use of lay heath advisors

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin burn propagation into surrounding cold fuel, enabling the possibility of high energy gain. While scientific breakeven (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

The Micropolitics of Obesity: Materialism, Markets and Food Sovereignty

This article shifts focus from an individualised and anthropocentric perspective on obesity, and uses a new materialist analysis to explore the assemblages of materialities producing fat and slim bodies. We report data from a study of adults’ accounts of food decision-making and practices, investigating circulations of matter and desires that affect the production, distribution, accumulation and dispersal of fat, and disclose a micropolitics of obesity, which affects bodies in both ‘becoming-fat’ and ‘becoming-slim’ assemblages. These assemblages comprise bodies, food, fat, physical environments, food producers and processing industries, supermarkets and other food retailers and outlets, diet regimens and weight loss clubs, and wider social, cultural and economic formations, along with the thoughts, feelings, ideas and human desires concerning food consumption and obesity. The analysis reveals the significance of the marketisation of food, and discusses whether public health responses to obesity should incorporate a food sovereignty component