207 research outputs found

    Positronium formation in methanol and ethanol

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    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    The geographies of food banks in the meantime

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    The authors gratefully acknowledge the support given by the British Academy for this research (grant no. SG131950). The ‘Emergency Food Provision in the UK’ research includes: over eighteen months of ethnographic research in a Trussell Trust Foodbank; a national survey of the Trussell Trust Network and Independent food banks (and other food aid providers); and in-depth interviews with food bank managers, volunteers and service-users in London, Bristol, Leicestershire, South Wales, Devon, and Cornwall

    Association of food security status with overweight and dietary intake: exploration of White British and Pakistani-origin families in the Born in Bradford cohort.

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    BACKGROUND: Food insecurity has been associated with dietary intake and weight status in UK adults and children although results have been mixed and ethnicity has not been explored. We aimed to compare prevalence and trajectories of weight and dietary intakes among food secure and insecure White British and Pakistani-origin families. METHODS: At 12 months postpartum, mothers in the Born in Bradford cohort completed a questionnaire on food security status and a food frequency questionnaire (FFQ) assessing their child's intake in the previous month; at 18 months postpartum, mothers completed a short-form FFQ assessing dietary intake in the previous 12 months. Weights and heights of mothers and infants were assessed at 12-, 24-, and 36-months postpartum, with an additional measurement of children taken at 4-5 years. Associations between food security status and dietary intakes were assessed using Wilcoxon-Mann-Whitney for continuous variables and χ2 or Fisher's exact tests for categorical variables. Quantile and logistic regression were used to determine dietary intakes adjusting for mother's age. Linear mixed effects models were used to assess longitudinal changes in body mass index (BMI) in mothers and BMI z-scores in children. RESULTS: At 12 months postpartum, White British mothers reported more food insecurity than Pakistani-origin mothers (11% vs 7%; p < 0.01) and more food insecure mothers were overweight. Between 12 and 36 months postpartum, BMI increased more among food insecure Pakistani-origin mothers (ÎČ = 0.77 units, [95% Confidence Interval [CI]: 0.40, 1.10]) than food secure (ÎČ = 0.44 units, 95% CI: 0.33, 0.55). This was also found in Pakistani-origin children (BMI z-score: food insecure ÎČ = 0.40 units, 95% CI: 0.22, 0.59; food secure ÎČ = 0.25 units, 95% CI: 0.20, 0.29). No significant increases in BMI were observed for food secure or insecure White British mothers while BMI z-score increased by 0.17 (95% CI: 0.13, 0.21) for food secure White British children. Food insecure mothers and children had dietary intakes of poorer quality, with fewer vegetables and higher consumption of sugar-sweetened drinks. CONCLUSIONS: Food security status is associated with body weight and dietary intakes differentially by ethnicity. These are important considerations for developing targeted interventions

    Physical education undergraduate students’ perceptions of their learning using the jigsaw learning method

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    Recognising the limited research around the use of cooperative learning in higher education, this case study sought to explore physical education students’ perceptions of learning using the jigsaw learning method. It examined the impact of two different aesthetic activities and two different groupings on students’ perceptions of their learning. A purposive sample of 36 third-year undergraduates was selected for the study. Data were collected using focus group interviews and reflective journals. Inductive analysis illustrated students’ perceptions of their own and others’ abilities, students’ empathy towards their peers, and how their perceptions of gymnastics and dance impacted on their perceptions of learning. Students felt that heterogeneous and friendship groupings have the potential to encourage high-order social and cognitive learning. However, those students with limited psychomotor abilities appear to be better served in friendship groupings to facilitate such learning. Students also favoured the ‘structured’ nature of gymnastics in comparison to dance for their own teaching and learning purposes. Irrespective of aesthetic activity or grouping utilised, students felt their psychomotor learning was limited. It is recommended that university staff consider using a mixture of groupings with a single cohort dependent on the practical ability of students and the use of more ‘structured’ activities. In doing so, students’ perceptions of their social, cognitive and psychomotor learning may improve and thereby encourage greater and more effective use of this innovative method in schools

    Improving model predictions for RNA interference activities that use support vector machine regression by combining and filtering features

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    <p>Abstract</p> <p>Background</p> <p>RNA interference (RNAi) is a naturally occurring phenomenon that results in the suppression of a target RNA sequence utilizing a variety of possible methods and pathways. To dissect the factors that result in effective siRNA sequences a regression kernel Support Vector Machine (SVM) approach was used to quantitatively model RNA interference activities.</p> <p>Results</p> <p>Eight overall feature mapping methods were compared in their abilities to build SVM regression models that predict published siRNA activities. The primary factors in predictive SVM models are position specific nucleotide compositions. The secondary factors are position independent sequence motifs (<it>N</it>-grams) and guide strand to passenger strand sequence thermodynamics. Finally, the factors that are least contributory but are still predictive of efficacy are measures of intramolecular guide strand secondary structure and target strand secondary structure. Of these, the site of the 5' most base of the guide strand is the most informative.</p> <p>Conclusion</p> <p>The capacity of specific feature mapping methods and their ability to build predictive models of RNAi activity suggests a relative biological importance of these features. Some feature mapping methods are more informative in building predictive models and overall <it>t</it>-test filtering provides a method to remove some noisy features or make comparisons among datasets. Together, these features can yield predictive SVM regression models with increased predictive accuracy between predicted and observed activities both within datasets by cross validation, and between independently collected RNAi activity datasets. Feature filtering to remove features should be approached carefully in that it is possible to reduce feature set size without substantially reducing predictive models, but the features retained in the candidate models become increasingly distinct. Software to perform feature prediction and SVM training and testing on nucleic acid sequences can be found at the following site: <url>ftp://scitoolsftp.idtdna.com/SEQ2SVM/</url>.</p

    TRAF4 is a novel phosphoinositide-binding protein modulating tight junctions and favoring cell migration

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    Tumor necrosis factor (TNF) receptor-associated factor 4 (TRAF4) is frequently overexpressed in carcinomas, suggesting a specific role in cancer. Although TRAF4 protein is predominantly found at tight junctions (TJs) in normal mammary epithelial cells (MECs), it accumulates in the cytoplasm of malignant MECs. How TRAF4 is recruited and functions at TJs is unclear. Here we show that TRAF4 possesses a novel phosphoinositide (PIP)-binding domain crucial for its recruitment to TJs. Of interest, this property is shared by the other members of the TRAF protein family. Indeed, the TRAF domain of all TRAF proteins (TRAF1 to TRAF6) is a bona fide PIP-binding domain. Molecular and structural analyses revealed that the TRAF domain of TRAF4 exists as a trimer that binds up to three lipids using basic residues exposed at its surface. Cellular studies indicated that TRAF4 acts as a negative regulator of TJ and increases cell migration. These functions are dependent from its ability to interact with PIPs. Our results suggest that TRAF4 overexpression might contribute to breast cancer progression by destabilizing TJs and favoring cell migration
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