11,806 research outputs found

    Higgs boson couplings to bosons with the ATLAS detector: Run 1 legacy

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    The final ATLAS measurements of Higgs boson production and couplings in the decay channels H → ZZ(∗) → , H → γγ and H → WW(∗) → νν are presented, based on the run 1 of the LHC. The analyses are optimised to measure the number of observed Higgs boson decays divided by the corresponding Standard Model predictions for individual Higgs boson production processes. Total, fiducial and differential cross-sections are also measured. No significant deviations from the predictions of the Standard Model are found

    Higgs boson couplings to bosons with the ATLAS detector: Run 1 legacy

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    The final ATLAS measurements of Higgs boson production and couplings in the decay channels H → ZZ(∗) → , H → γγ and H → WW(∗) → νν are presented, based on the run 1 of the LHC. The analyses are optimised to measure the number of observed Higgs boson decays divided by the corresponding Standard Model predictions for individual Higgs boson production processes. Total, fiducial and differential cross-sections are also measured. No significant deviations from the predictions of the Standard Model are found

    Allometric Trajectories and \u201cStress\u201d: A Quantitative Approach

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    The term \u201cstress\u201d is an important but vague term in plant biology. We show situations in which thinking in terms of \u201cstress\u201d is profitably replaced by quantifying distance from functionally optimal scaling relationships between plant parts. These relationships include, for example, the often-cited one between leaf area and sapwood area, which presumably reflects mutual dependence between source and sink tissues and which scales positively within individuals and across species. These relationships seem to be so basic to plant functioning that they are favored by selection across nearly all plant lineages. Within a species or population, individuals that are far from the common scaling patterns are thus expected to perform negatively. For instance, \u201ctoo little\u201d leaf area (e.g. due to herbivory or disease) per unit of active stem mass would be expected to incur to low carbon income per respiratory cost and thus lead to lower growth. We present a framework that allows quantitative study of phenomena traditionally assigned to \u201cstress,\u201d without need for recourse to this term. Our approach contrasts with traditional approaches for studying \u201cstress,\u201d e.g. revealing that small \u201cstressed\u201d plants likely are in fact well suited to local conditions. We thus offer a quantitative perspective to the study of phenomena often referred to under such terms as \u201cstress,\u201d plasticity, adaptation, and acclimation

    Dextran sulfate enhances the level of an oxidative DNA damage biomarker, 8-oxo-7,8-dihydro-2 0-deoxyguanosine, in rat colonic mucosa

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    Dextran sodium sulfate (DSS) given in drinking water can induce colonic Inflammation and produce colorectal tumors in rodents, although it is not directly genotoxic. The hypothesis that DSS can produce free radicals and induce oxidative DNA damage in colonic mucosa has been tested. In rats fed for 2 days with water containing 3% and 6% DSS, colonic Inflammation manifestations were recorded and 8-oxo-7,8-dihydro-2 0-deoxyguanosine (8-oxodGuo), a major biomarker of oxidative DNA damage, was assayed in colonic mucosa. As compared with control rats given pure water, inflammatory manifestations were seen in rats given DSS. At the same time, 8-oxodGuo levels in colonic mucosa were doubled (P , 0:001). These results suggest that formation of oxidative DNA damage in colonic mucosa depends on inflammation and maybe on the production of reactive oxygen species. This study shows that DSS can induce oxidative DNA damage within only 2 days, which could explain in part its carcinogenic properties

    Development of Measures of Success for Corporate Level Air Force Acquisition Initiatives

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    The goal of this research is to suggest a framework for developing measures of success for corporate level Air Force acquisition initiatives. Because this research is exploratory, it focuses on only one initiative: the 2002 Lighting Bolt initiative Focus on results, not process. A qualitative method approach was used to suggest a four part framework. Through the review of literature, common steps for creating metrics were established and recurrent characteristics of good metrics were identified. Then interviews were conducted with acquisition practitioners who have experience with the initiative. Finally, those three parts were applied to the initiative as a case study and metrics suggested as a result. This study gives Air Force leaders clear, implementable metrics that can be used as measures of success for the initiative, and provides recommendations to improve this initiative s performance and that of future corporate Air Force acquisition initiatives. This study also gives leaders insight into whether or not this initiative and others like it are an appropriate and effective way to drive the changes they are meant to bring about. Finally, from a broader perspective, the framework used in this study can be used to develop metrics for other corporate level initiatives

    Meat and cancer: haemoglobin and haemin in a low calcium diet promote colorectal carcinogenesis at the aberrant crypt stage in rats

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    High intake of red meat, but not of white meat, is associated with an increased risk of colon cancer. However, red meat does not promote cancer in rodents. Haemin, added to low-calcium diets, increases colonic proliferation, and haemoglobin, added to high-fat diets, increases the colon tumour incidence in rats, an effect possibly due to peroxyl radicals. We thus speculated that haem might be the promoting agent in meat, and that prevention strategies could use calcium and antioxidants. These hypotheses were tested in rats at the aberrant crypt foci (ACF) stage at 100 days. F344 rats (n = 124) were given an injection of azoxymethane and were then randomized to 11 groups fed with low-calcium (20 micro mol/g) AIN76-based diets, containing 5% safflower oil. Haemin (0.25, 0.5 and 1.5 micro mol/g) or haemoglobin (1.5 and 3 micro mol haem/g) was added to five experimental diets, compared with a control diet without haem. Three other high-haemin diets (1.5 micro mol/g) were supplemented with calcium (250 micro mol/g), antioxidant butylated hydroxyanisole and rutin (0.05% each), and olive oil, which replaced safflower oil. Faecal water was assayed for lipid peroxidation by thiobarbituric acid reactive substances (TBARs) test, and for cytolytic activity. Haemin strikingly increased the ACF size, dose-dependently, from 2.6 to 11.4 crypts/ACF (all P < 0.001). The high-haemin diet also increased the number of ACF per colon (P < 0.001). Promotion was associated with increased faecal water TBARs and cytotoxicity. Calcium, olive oil and antioxidants each inhibited the haemin-induced ACF promotion, and normalized the faecal TBARs and cytotoxicity. The haemoglobin diets increased the number of ACF and faecal TBARs, but not the ACF size or the faecal cytotoxicity. In conclusion, dietary haemin is the most potent known ACF promoter. Haemoglobin is also a potent promoter of colorectal carcinogenesis. The results suggest that myoglobin in red meat could promote colon cancer. Diets high in calcium, or in oxidation-resistant fats, may prevent the possible cancer-promoting effect of red meat
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