2,015 research outputs found

    Shape memory characteristics of woven glass fibre fabric reinforced epoxy composite in flexure

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    Shape memory characteristics of a woven glass fibre (GF) fabric reinforced epoxy composite (reinforcement content: 38 vol.%) were assessed in three point bending mode in a dynamic-mechanical analysis device and compared to those of the parent epoxy resin (EP). From unconstrained tests the shape fixity and recovery ratios and the recovery rate, whereas from constrained tests the recovery stress were determined. The shape fixity and recovery rate decreased due to the GF reinforcement which had, however, no effect on the shape recovery. Major benefit of the woven GF fabric was that the recovery stress could be enhanced by two orders of magnitude in comparison to the neat EP. GF reinforcement was accompanied with a substantial decrease in the failure-free flexural deformability of the composite specimen

    Spectroscopy and Reactivity of a Photogenerated Tryptophan Radical in a Structurally Defined Protein Environment

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    Near-UV irradiation of structurally characterized [Re(I)(CO)_3(1,10-phenanthroline)(Q107H)](W48F/Y72F/H83Q/Y108W)AzM(II) [Az = Pseudomonas aeruginosa azurin, M = Cu, Zn]/[Co(NH_3)_5Cl]Cl_2 produces a tryptophan radical (W108•) with unprecedented kinetic stability. After rapid formation (k = 2.8 × 10^6 s^(-1)), the radical persists for more than 5 h at room temperature in the folded ReAzM(II) structure. The absorption spectrum of ReAz(W108•)M(II) exhibits maxima at 512 and 536 nm. Oxidation of K_4[Mo(CN)_8] by ReAz(W108•)Zn(II) places the W108•/W108 reduction potential in the protein above 0.8 V vs NHE

    Why a universal Child Grant makes sense in Nepal: a four-step analysis

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    Whether cash transfers should be poverty targeted or universal within certain social categories remains a hotly debated topic. Recent plans to expand Nepal’s Child Grant programme brought this question sharply into focus. Using available secondary data, this article presents a four-step analysis that examines the costs and benefits of different approaches. Given the country’s poverty profile, the theoretical results of different targeting models, government capacity and overall costs, a universal (age-cohort targeted) approach achieves the best outcomes for childre

    The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effect of dose and time since intervention exposure.

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    BACKGROUND: Despite recent decreases in HIV incidence in many sub-Saharan African countries, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term evaluation in 2007/8 found that the intervention improved knowledge, attitudes to sex and some reported risk behaviours, but not HIV or HSV2 prevalence. The aim of this paper was to assess the differential impact of the intervention according to gender, age, marital status, number of years of exposure and time since last exposure to the intervention. METHODS: In 2007, a cross-sectional survey was conducted in the 20 trial communities among 13,814 young people (15-30 yrs) who had attended intervention or comparison schools between 1999 and 2002. Outcomes for which the intervention had an impact in 2001 or 2007 were included in this subgroup analysis. Data were analysed using cluster-level methods for stratified cluster-randomised trials, using interaction tests to determine if intervention impact differed by subgroup. RESULTS: Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect-modifiers emerged. Impact on pregnancy knowledge and reported attitudes to sex increased with years of exposure to high-quality intervention. CONCLUSIONS: The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. This suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza. TRIAL REGISTRATION: ClinicalTrials.gov NCT00248469

    Robust Detection of Hierarchical Communities from Escherichia coli Gene Expression Data

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    Determining the functional structure of biological networks is a central goal of systems biology. One approach is to analyze gene expression data to infer a network of gene interactions on the basis of their correlated responses to environmental and genetic perturbations. The inferred network can then be analyzed to identify functional communities. However, commonly used algorithms can yield unreliable results due to experimental noise, algorithmic stochasticity, and the influence of arbitrarily chosen parameter values. Furthermore, the results obtained typically provide only a simplistic view of the network partitioned into disjoint communities and provide no information of the relationship between communities. Here, we present methods to robustly detect coregulated and functionally enriched gene communities and demonstrate their application and validity for Escherichia coli gene expression data. Applying a recently developed community detection algorithm to the network of interactions identified with the context likelihood of relatedness (CLR) method, we show that a hierarchy of network communities can be identified. These communities significantly enrich for gene ontology (GO) terms, consistent with them representing biologically meaningful groups. Further, analysis of the most significantly enriched communities identified several candidate new regulatory interactions. The robustness of our methods is demonstrated by showing that a core set of functional communities is reliably found when artificial noise, modeling experimental noise, is added to the data. We find that noise mainly acts conservatively, increasing the relatedness required for a network link to be reliably assigned and decreasing the size of the core communities, rather than causing association of genes into new communities.Comment: Due to appear in PLoS Computational Biology. Supplementary Figure S1 was not uploaded but is available by contacting the author. 27 pages, 5 figures, 15 supplementary file

    Early Resolution of Convergence Spasms Following the Addition of Antipsychotic Medications

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    We report a case of early resolution of convergence spasms following the addition of antipsychotic medications and present it as a possible alternative to the conventional treatment for convergence spasms. The cessation of atropinization of the eyes and the use of reading glasses was achieved after only 2 months following the initiation of antipsychotic medications for childhood emotional disorder
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