327 research outputs found

    A CTMC study of collisions between protons and H2+H_2^+ molecular ions

    Full text link
    We study numerically collisions between protons and H2+H_2^+ molecular ions at intermediate impact energies by using the Classical Trajectory Monte Carlo method (CTMC). Total and differential cross sections are computed. The results are compared with: a) the standard one electron--two nucleon scattering, and b) the quantum mechanical treatment of the H+−H2+ H^{+} - H^{+}_{2} scattering.Comment: ReVTeX, 5 pages + 5 figs. (EPS) To be published in Physica Script

    The cash crop boom in southern Myanmar: tracing land use regime shifts through participatory mapping

    Get PDF
    Tropical forest landscapes are undergoing vast transformations. Myanmar was long an exceptionto this trend–until recent policy reforms put economic development at the forefront. Underambiguous land rights, commercial agriculture has spread rapidly, causing an unprecedentedloss of biodiversity-rich forest. In south-eastern Myanmar, where land tenure is highly contesteddue to several decades of conflict, scientific evidence on these complex social-ecological pro-cesses is lacking. In the absence of past satellite data, we applied a participatory mappingapproach and co-produced annual land use information with local land users between 1990and 2017 for two case study landscapes. Results show that both landscapes have undergonea land use regime shift from small-scale farmers’shifting cultivation to plantations of rubber, betelnut, cashew, and oil palm. These changes are likely to have long-term impacts on land users’livelihoods and the environment. We call for a reconsideration of land governance arrangementsand concerted land use planning that respects the rights of local land users and strengthens theirrole as environmental stewards. Applied with careful facilitation, participatory mapping could bean important tool to engage communities in the highly challenging process of transforming landgovernance to achieve more sustainable outcomes in this post-conflict context

    Association between anthropometric indices and cardiometabolic risk factors in pre-school children

    Get PDF
    ABSTRACT: The world health organization (WHO) and the Identification and prevention of dietary- and lifestyle-induced health effects in children and infants- study (IDEFICS), released anthropometric reference values obtained from normal body weight children. This study examined the relationship between WHO [body mass index (BMI) and triceps- and subscapular-skinfolds], and IDEFICS (waist circumference, waist to height ratio and fat mass index) anthropometric indices with cardiometabolic risk factors in pre-school children ranging from normal body weight to obesity. Methods: A cross-sectional study with 232 children (aged 4.1 ± 0.05 years) was performed. Anthropometric measurements were collected and BMI, waist circumference, waist to height ratio, triceps- and subscapular-skinfolds sum and fat mass index were calculated. Fasting glucose, fasting insulin, homeostasis model analysis insulin resistance (HOMA-IR), blood lipids and apolipoprotein (Apo) B-100 (Apo B) and Apo A-I were determined. Pearson’s correlation coefficient, multiple regression analysis and the receiver-operating characteristic (ROC) curve analysis were run. Results: 51 % (n = 73) of the boys and 52 % (n = 47) of the girls were of normal body weight, 49 % (n = 69) of the boys and 48 % (n = 43) of the girls were overweight or obese. Anthropometric indices correlated (p 0.68 to AUC < 0.76). Conclusions: WHO and IDEFICS anthropometric indices correlated similarly with fasting insulin and HOMA-IR. The diagnostic accuracy of the anthropometric indices as a proxy to identify children with insulin resistance was similar. These data do not support the use of waist circumference, waist to height ratio, triceps- and subscapular- skinfolds sum or fat mass index, instead of the BMI as a proxy to identify pre-school children with insulin resistance, the most frequent alteration found in children ranging from normal body weight to obesity

    At-Risk and Recent-Onset Type 1 Diabetic Subjects Have Increased Apoptosis in the CD4+CD25+(high) T-Cell Fraction

    Get PDF
    BACKGROUND: In experimental models, Type 1 diabetes T1D can be prevented by adoptive transfer of CD4+CD25+ FoxP3+ suppressor or regulatory T cells. Recent studies have found a suppression defect of CD4+CD25+(high) T cells in human disease. In this study we measure apoptosis of CD4+CD25+(high) T cells to see if it could contribute to reduced suppressive activity of these cells. METHODS AND FINDINGS: T-cell apoptosis was evaluated in children and adolescent 35 females/40 males subjects comprising recent-onset and long-standing T1D subjects and their first-degree relatives, who are at variable risk to develop T1D. YOPRO1/7AAD and intracellular staining of the active form of caspase 3 were used to evaluate apoptosis. Isolated CD4+CD25+(high) and CD4+CD25− T cells were co-cultured in a suppression assay to assess the function of the former cells. We found that recent-onset T1D subjects show increased apoptosis of CD4+CD25+(high) T cells when compared to both control and long-standing T1D subjects p<0.0001 for both groups. Subjects at high risk for developing T1D 2–3Ab+ve show a similar trend p<0.02 and p<0.01, respectively. On the contrary, in long-standing T1D and T2D subjects, CD4+CD25+(high) T cell apoptosis is at the same level as in control subjects p = NS. Simultaneous intracellular staining of the active form of caspase 3 and FoxP3 confirmed recent-onset FoxP3+ve CD4+CD25+(high) T cells committed to apoptosis at a higher percentage 15.3±2.2 compared to FoxP3+ve CD4+CD25+(high) T cells in control subjects 6.1±1.7 p<0.002. Compared to control subjects, both recent-onset T1D and high at-risk subjects had significantly decreased function of CD4+CD25+(high) T cells p = 0.0007 and p = 0.007, respectively. CONCLUSIONS: There is a higher level of ongoing apoptosis in CD4+CD25+(high) T cells in recent-onset T1D subjects and in subjects at high risk for the disease. This high level of CD4+CD25+(high) T-cell apoptosis could be a contributing factor to markedly decreased suppressive potential of these cells in recent-onset T1D subjects
    • …
    corecore