1,107 research outputs found

    Electroweak corrections to Higgs-strahlung off W/Z bosons at the Tevatron and the LHC with HAWK

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    The associate production of Higgs bosons with W or Z bosons, known as Higgs-strahlung, is an important search channel for Higgs bosons at the hadron colliders Tevatron and LHC for low Higgs-boson masses. We refine a previous calculation of next-to-leading-order electroweak corrections (and recalculate the QCD corrections) upon including the leptonic decay of the W/Z bosons, thereby keeping the fully differential information of the 2-lepton + Higgs final state. The gauge invariance of the W/Z-resonance treatment is ensured by the use of the complex-mass scheme. The electroweak corrections, which are at the level of -(5-10)% for total cross sections, further increase in size with increasing transverse momenta p_T in differential cross sections. For instance, for p_T,H >~ 200GeV, which is the interesting range at the LHC, the electroweak corrections to WH production reach about -14% for M_H = 120GeV. The described corrections are implemented in the HAWK Monte Carlo program, which was initially designed for the vector-boson-fusion channel, and are discussed for various distributions in the production channels pp / p \bar p -> H + l nu_l / l^-l^+ / nu_l \bar nu_l + X.Comment: 22 p

    A Review of Time Courses and Predictors of Lipid Changes with Fenofibric Acid-Statin Combination

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    Fibrates activate peroxisome proliferator activated receptor α and exert beneficial effects on triglycerides, high-density lipoprotein cholesterol, and low density lipoprotein subspecies. Fenofibric acid (FA) has been studied in a large number of patients with mixed dyslipidemia, combined with a low- or moderate-dose statin. The combination of FA with simvastatin, atorvastatin and rosuvastatin resulted in greater improvement of the overall lipid profile compared with the corresponding statin dose. The long-term efficacy of FA combined with low- or moderate- dose statin has been demonstrated in a wide range of patients, including patients with type 2 diabetes mellitus, metabolic syndrome, or elderly subjects. The FA and statin combination seems to be a reasonable option to further reduce cardiovascular risk in high-risk populations, although trials examining cardiovascular disease events are missing

    The impact of population heterogeneity on risk estimation in genetic counseling

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    BACKGROUND: Genetic counseling has been an important tool for evaluating and communicating disease susceptibility for decades, and it has been applied to predict risks for a wide class of hereditary disorders. Most diseases are complex in nature and are affected by multiple genes and environmental conditions; it is highly likely that DNA tests alone do not define all the genetic factors responsible for a disease, so that persons classified into the same risk group by DNA testing actually could have different disease susceptibilities. Ignorance of population heterogeneity may lead to biased risk estimates, whereas additional information on population heterogeneity may improve the precision of such estimates. METHODS: Although DNA tests are widely used, few studies have investigated the accuracy of the predicted risks. We examined the impact of population heterogeneity on predicted disease risks by simulation of three different heterogeneity scenarios and studied the precision and accuracy of the risks estimated from a logistic regression model that ignored population heterogeneity. Moreover, we also incorporated information about population heterogeneity into our original model and investigated the resulting improvement in the accuracy of risk estimation. RESULTS: We found that heterogeneity in one or more categories could lead to biased estimates not only in the "contaminated" categories but also in other homogeneous categories. Incorporating information about population heterogeneity into the original model greatly improved the accuracy of risk estimation. CONCLUSIONS: Our findings imply that without thorough knowledge about genetic basis of the disease, risks estimated from DNA tests may be misleading. Caution should be taken when evaluating the predicted risks obtained from genetic counseling. On the other hand, the improved accuracy of risk estimates after incorporating population heterogeneity information into the model did point out a promising direction for genetic counseling, since more and more new techniques are being invented and disease etiology is being better understood

    Absence of Evidence for MHC–Dependent Mate Selection within HapMap Populations

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    The major histocompatibility complex (MHC) of immunity genes has been reported to influence mate choice in vertebrates, and a recent study presented genetic evidence for this effect in humans. Specifically, greater dissimilarity at the MHC locus was reported for European-American mates (parents in HapMap Phase 2 trios) than for non-mates. Here we show that the results depend on a few extreme data points, are not robust to conservative changes in the analysis procedure, and cannot be reproduced in an equivalent but independent set of European-American mates. Although some evidence suggests an avoidance of extreme MHC similarity between mates, rather than a preference for dissimilarity, limited sample sizes preclude a rigorous investigation. In summary, fine-scale molecular-genetic data do not conclusively support the hypothesis that mate selection in humans is influenced by the MHC locus

    FITBAR: a web tool for the robust prediction of prokaryotic regulons

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    <p>Abstract</p> <p>Background</p> <p>The binding of regulatory proteins to their specific DNA targets determines the accurate expression of the neighboring genes. The <it>in silico </it>prediction of new binding sites in completely sequenced genomes is a key aspect in the deeper understanding of gene regulatory networks. Several algorithms have been described to discriminate against false-positives in the prediction of new binding targets; however none of them has been implemented so far to assist the detection of binding sites at the genomic scale.</p> <p>Results</p> <p>FITBAR (Fast Investigation Tool for Bacterial and Archaeal Regulons) is a web service designed to identify new protein binding sites on fully sequenced prokaryotic genomes. This tool consists in a workbench where the significance of the predictions can be compared using different statistical methods, a feature not found in existing resources. The Local Markov Model and the Compound Importance Sampling algorithms have been implemented to compute the P-value of newly discovered binding sites. In addition, FITBAR provides two optimized genomic scanning algorithms using either log-odds or entropy-weighted position-specific scoring matrices. Other significant features include the production of a detailed genomic context map for each detected binding site and the export of the search results in spreadsheet and portable document formats. FITBAR discovery of a high affinity <it>Escherichia coli </it>NagC binding site was validated experimentally <it>in vitro </it>as well as <it>in vivo </it>and published.</p> <p>Conclusions</p> <p>FITBAR was developed in order to allow fast, accurate and statistically robust predictions of prokaryotic regulons. This feature constitutes the main advantage of this web tool over other matrix search programs and does not impair its performance. The web service is available at <url>http://archaea.u-psud.fr/fitbar</url>.</p

    Reviewing, indicating, and counting books for modern research evaluation systems

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    In this chapter, we focus on the specialists who have helped to improve the conditions for book assessments in research evaluation exercises, with empirically based data and insights supporting their greater integration. Our review highlights the research carried out by four types of expert communities, referred to as the monitors, the subject classifiers, the indexers and the indicator constructionists. Many challenges lie ahead for scholars affiliated with these communities, particularly the latter three. By acknowledging their unique, yet interrelated roles, we show where the greatest potential is for both quantitative and qualitative indicator advancements in book-inclusive evaluation systems.Comment: Forthcoming in Glanzel, W., Moed, H.F., Schmoch U., Thelwall, M. (2018). Springer Handbook of Science and Technology Indicators. Springer Some corrections made in subsection 'Publisher prestige or quality

    The place of values in the aims of school science education

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    Debates about the aims of school science education are perennial (e.g., Reiss & White, 2014; see also Kidman & Fensham, Chapter “ Intended, Achieved and Unachieved Values of Science Education” this volume), particularly in Western cultures. In this chapter we review some of these arguments about the aims of school science education, and look at what has changed in the last decade since one of us (Michael) considered a similar debate (see Reiss, 2007). We have situated this review of arguments in current global circumstances including rapid technological advances, a continuing demand for workers with STEM (Science, Technology, Engineering and Mathematics) qualifications and the increasing acknowledgement of the deeply worrying effects that humans have on the Earth’s ecology, and indeed its future. Part of our argument is that decisions about the aims of school science education are inevitably decisions about values in education in general and values in school science education more specifically. This means that for a country, a group of schools, an individual school or a classroom teacher to come to a view about the aims of science education in the classroom is to have made a judgement, implicitly or explicitly, about values

    Effects of retinoic acid on compensatory lung growth

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    <p>Abstract</p> <p>Background</p> <p>We investigated the effect of Retinoic acid in the growth of contralateral lung after pneumonectomy.</p> <p>Methods</p> <p>Twentyone adult male Wistar albino rats from the same colony were used. They were divided into three groups (Group A, B and C). Group A undergone only left posterolateral thoracotomy. In Group B and C, the rats were subjected to left posterolateral thoracotomy and left pneumonectomy. In Group C, rats were given intraperitoneal Retinoic acid during the operation and continued to be given everyday postoperatively. Rats were sacrificed on the 10<sup>th </sup>day and their total body, right lung weights and right lung volumes were measured.</p> <p>Results</p> <p>The volume and weight indices of the lung were found to be higher in Group C. In histopathological examination, there was a reduction in the mean number of alveoli in Group B and C. A significant rise in the mean dimension and average wall thickness of the alveolar structure were determined in Group C.</p> <p>Conclusion</p> <p>Retinoic acid contributes to the compensatory growth of the residual lung tissue.</p

    Functional compensation of glutathione S-transferase M1 (GSTM1) null by another GST superfamily member,GSTM2

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    The gene for glutathione-S-transferase (GST) M1 (GSTM1), a member of the GST-superfamily, is widely studied in cancer risk with regard to the homozygous deletion of the gene (GSTM1 null), leading to a lack of corresponding enzymatic activity. Many of these studies have reported inconsistent findings regarding its association with cancer risk. Therefore, we employed in silico, in vitro, and in vivo approaches to investigate whether the absence of a functional GSTM1 enzyme in a null variant can be compensated for by other family members. Through the in silico approach, we identified maximum structural homology between GSTM1 and GSTM2. Total plasma GST enzymatic activity was similar in recruited individuals, irrespective of their GSTM1 genotype (positive/null). Furthermore, expression profiling using real-time PCR, western blotting, and GSTM2 overexpression following transient knockdown of GSTM1 in HeLa cells confirmed that the absence of GSTM1 activity can be compensated for by the overexpression of GSTM
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