1,273 research outputs found

    EFFICIENCY OF SMALL LANDHOLDERS IN EASTERN PARAGUAY

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    The relative efficiency levels of 283 rural households from three regions in eastern Paraguay are measured using a nonparametric approach. Technical, allocative, and scale efficiency measures are calculated both at national and regional levels, and factors that may affect the efficiency levels are analyzed econometrically. The three regions selected for this study represent distinct production systems and socio-economic conditions: production of traditional crops or extensive livestock operations; a dynamic region with massive in-migration where capitalized farms produce soybeans and wheat; and an older region, integrated with urban areas, where depleted and highly fragmented land has forced households to rely on nonagricultural sources of income. Nonparametric results show high levels of technical efficiency across all three regions, but low levels of allocative and scale efficiency. Because policies to increase scale efficiency are politically unpalatable, the factors affecting allocative efficiency are explored. Significant factors include employment opportunities, land titling, and access to credit, markets, and extension services.Farm Management,

    THE DISTRIBUTION OF BENEFITS RESULTING FROM BIOTECHNOLOGY ADOPTION

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    The purposes of this study are two-fold: (1) to estimate the size of total benefits arising from the adoption of agricultural biotechnology, and (2) to measure the distribution of total benefits among key stakeholders along the production and marketing chain, including U.S. farmers, gene developers, germplasm suppliers, U.S. consumers, and the producers and consumers in the rest of the world. This study focuses on the benefits that resulted from the adoption of herbicide-tolerant soybeans as well as insect-resistant (Bt) and herbicide-tolerant cotton in 1997. In this analysis, various data sources are examined for measuring the farm-level effects of adopting biotechnology and the resulting benefit estimates are compared. The size and distribution of the benefits arising from the adoption of biotech crops vary significantly, depending on the farm-level effects obtained from the various data sources and the supply and demand elasticity assumptions for the domestic and world markets. Estimates of the benefits derived from farm-level impacts that isolate the effects biotechnology appear to be the most plauible. This study does not lend support to the popular belief that U.S. farmers received at least one-half, or as much as two-thirds, of the total benefits realized from the adoption of biotechnology. In contrast, the results of this study indicate that in 1997, U.S. farmers realized considerably less than half of the total benefits. The bulk of the benefits appear to have gone to the gene supplier, seed companies, U.S. consumers, and the rest of the world.Research and Development/Tech Change/Emerging Technologies,

    Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease.

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    ObjectiveNonalcoholic fatty liver disease (NAFLD) affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD.MethodsCohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks.ResultsPrevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003). Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m2, 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively). Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05).ConclusionsIn conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD

    A [SU(6)]4^4 FLAVOR MODEL WITHOUT MIRROR FERMIONS

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    We introduce a three family extension of the Pati-Salam model which is anomaly-free and contains in a single irreducible representation the known quarks and leptons without mirror fermions. Assuming that the breaking of the symmetry admits the implementation of the survival hypothesis, we calculate the mass scales using the renormalization group equation. Finally we show that the proton remains perturbatively stable.Comment: Z PHYS. C63, 339 (1994

    Surface effects on the radiation response of nanoporous Au foams

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    We report on an experimental and simulation campaign aimed at exploring the radiation response of nanoporous Au(np-Au) foams. We find different defect accumulation behavior by varying radiation dose-rate in ion-irradiated np-Au foams. Stacking fault tetrahedra are formed when np-Au foams are irradiated at high dose-rate, but they do not seem to be formed in np-Au at low dose-rate irradiation. A model is proposed to explain the dose-rate dependent defect accumulation based on these results.Fil: Fu, E. G.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Caro, M.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Zepeda Ruiz, L. A.. Lawrence Livermore National Laboratory. Physical and Life Sciences Directorate; Estados UnidosFil: Wang, Y. Q.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Baldwin, K.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Bringa, Eduardo Marcial. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Nastasi, M.. University of Nebraska-Lincoln. Nebraska Center for Energy Sciences Research; Estados UnidosFil: Caro, A.. Los Alamos National High Magnetic Field Laboratory; Estados Unido

    Removal of Cu2+ and Ni2+ from Aqueous Solution using SnO2 Nanomaterial effect of: pH, Time, Temperature, interfering cations

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    Tin oxide, SnO2, nanomaterial was synthesized and tested for the removal of Cu2+ and Ni2+ ions from aqueous solutions. Various parameters for the binding were investigated in batch studied, which included pH, time, temperature, and interferences. In addition, isotherm studied were performed to determine the maximum binding capacity for both Cu2+ and Ni2+ ions. The optimal binding pH determined from the effects of pH were to be at pH 5 for both the Cu2+ and Ni2+ ions. The isotherm studies were performed at temperatures of 4°C, 25 °C, and 45 °C for both the Cu2+ and Ni2+ ions and were found to follow the Langmuir isotherm model. The binding capacities for the Cu2+ ions were 2.63 mg/g, 2.95 mg/g and 3.27 mg/g at the aforementioned temperatures, respectively. Whereas the binding capacities for Ni2+ were 0.79 mg/g, 1.07 mg/g, and 1.46 mg/g at the respective temperatures. The determined thermodynamic parameters for the binding showed that the binding processes for the reactions were endothermic, as the ΔG was observed to decrease with decreasing temperatures. As well the ΔH was 28.73 kJ/mol for Cu2+ (III) and 13.37 kJ/mol for Ni2+. The ΔS was observed to be 92.65 J/mol for Cu2+ and 54.53 J/mol for Ni2+. The free energy of adsorption for the Cu2+ was determined to be 13.99 kJ/mol and the activation energy for the binding of Ni2+ was determined to be 8.09 KJ/mol. The activation energy data indicate that the reaction was occurring through chemisorptio

    Compressional residual stress in Bastogne boudins revealed by synchrotron X‐ray microdiffraction

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    Lattice distortions in crystals can be mapped at the micron scale using synchrotron X-ray Laue microdiffraction (μXRD). From lattice distortions the shape and orientation of the elastic strain tensor can be derived and interpreted in terms of residual stress. Here we apply the new method to vein quartz from the original boudinage locality at Bastogne, Belgium. A long-standing debate surrounds the kinematics of the Bastogne boudins. The μXRD measurements reveal a shortening residual elastic strain, perpendicular to the vein wall, corroborating the model that the Bastogne boudins formed by layer-parallel shortening and not by layer-parallel extension, as is in the geological community generally inferred by the process of boudinage

    Global health and foreign policy.

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    Health has long been intertwined with the foreign policies of states. In recent years, however, global health issues have risen to the highest levels of international politics and have become accepted as legitimate issues in foreign policy. This elevated political priority is in many ways a welcome development for proponents of global health, and it has resulted in increased funding for and attention to select global health issues. However, there has been less examination of the tensions that characterize the relationship between global health and foreign policy and of the potential effects of linking global health efforts with the foreign-policy interests of states. In this paper, the authors review the relationship between global health and foreign policy by examining the roles of health across 4 major components of foreign policy: aid, trade, diplomacy, and national security. For each of these aspects of foreign policy, the authors review current and historical issues and discuss how foreign-policy interests have aided or impeded global health efforts. The increasing relevance of global health to foreign policy holds both opportunities and dangers for global efforts to improve health
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