Perturbative corrections to power suppressed effects in semileptonic B decays

We compute the $O(\alpha_s)$ corrections to the Wilson coefficient of the chromomagnetic operator in inclusive semileptonic B decays. The results are employed to evaluate the complete $O(\alpha_s \Lambda^2/m_b^2)$ correction to the semileptonic width and to the first moments of the lepton energy distribution.Comment: 15 pages, 2 figure

Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

QED effects in inclusive semi-leptonic BB decays

We perform a detailed analysis of QED corrections to the total decay width and the electron energy spectrum of the inclusive semi-leptonic $B \to X_c e \nu$ decay. Our calculation includes short-distance electroweak corrections, the complete ${\cal O}(\alpha)$ partonic terms and leading-logarithmic QED effects up to ${\cal O}(\Lambda^3_{\rm QCD}/m_b^3)$. In the case of the branching ratio and the electron energy moments we perform a detailed numerical comparison of our results against those obtained with the Monte Carlo (MC) tool PHOTOS. While the comparison indicates good overall agreement, our computation contains QED effects not included in PHOTOS and should therefore provide a better description of photon radiation to $B \to X_c e \nu$ as measured by the $B$-factories. The calculations performed here represent the first steps in the construction of a fully differential higher-order QED MC generator for inclusive semi-leptonic $B$ decays.Comment: 40 pages, 8 figures and 3 table

Visceral adiposity index and DHEAS are useful markers of diabetes risk in women with polycystic ovary syndrome

Objective: On the basis of the known diabetes risk in polycystic ovary syndrome (PCOS), recent guidelines of the Endocrine Society recommend the use of an oral glucose tolerance test (OGTT) to screen for impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) in all women with PCOS. However, given the high prevalence of PCOS, OGTTwould have ahigh cost-benefit ratio. In this study, we identified, through a receiver operating characteristic analysis, simple predictive markers of the composite endpoint (impaired fasting glucose (IFG) or IGT or IFGCIGT or T2DM) in women with PCOS according to the Rotterdam criteria.Design: We conducted a cross-sectional study of 241 women with PCOS in a university hospital setting.Methods: Clinical, anthropometric, and metabolic (including OGTT) parameters were evaluated. The homeostasis model assessment of insulin resistance (HOMA2-IR), the Matsuda index of insulin sensitivity, and the oral dispositional index and visceral adiposity index (VAI) were determined.Results: Out of 241 women included in this study, 28 (11.6%) had an IFG, 13 (5.4%) had IGT, four (1.7%) had IFGCIGT, and four (1.7%) had T2DM. Among the anthropometric variables examined, the VAI had a significantly higher C-statistic compared with BMI (0.760 (95% CI: 0.70-0.81) vs 0.613 (95% CI: 0.54-0.67); PZ0.014) and waist circumference (0.760 (95% CI: 0.70-0.81) vs 0.619 (95% CI: 0.55-0.68); PZ0.028). Among all the hormonal and metabolic serum variables examined, DHEAS showed the highest C-statistic (0.720 (95% CI: 0.65-0.77); P<0.001).Conclusions: In addition to fasting glucose, the VAI and DHEAS may be considered useful tools for prescreening in all women with PCOS without the classical risk factors for diabetes