427 research outputs found

    Perfect countably infinite Steiner triple systems

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    We use a free construction to prove the existence of perfect Steiner triple systems on a countably infinite point set. We use a specific countably infinite family of partial Steiner triple systems to start the construction, thus yielding 2ℵ0 non-isomorphic perfect systems

    Antenatal Steroid Therapy for Fetal Lung Maturation and the Subsequent Risk of Childhood Asthma: A Longitudinal Analysis

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    This study was designed to test the hypothesis that fetal exposure to corticosteroids in the antenatal period is an independent risk factor for the development of asthma in early childhood with little or no effect in later childhood. A population-based cohort study of all pregnant women who resided in Nova Scotia, Canada, and gave birth to a singleton fetus between 1989 and 1998 was undertaken. After a priori specified exclusions, 80,448 infants were available for analysis. Using linked health care utilization records, incident asthma cases developed after 36 months of age were identified. Extended Cox proportional hazards models were used to estimate hazard ratios while controlling for confounders. Exposure to corticosteroids during pregnancy was associated with a risk of asthma in childhood between 3–5 years of age: adjusted hazard ratio of 1.19 (95% confidence interval: 1.03, 1.39), with no association noted after 5 years of age: adjusted hazard ratio for 5–7 years was 1.06 (95% confidence interval: 0.86, 1.30) and for 8 or greater years was 0.74 (95% confidence interval: 0.54, 1.03). Antenatal steroid therapy appears to be an independent risk factor for the development of asthma between 3 and 5 years of age

    Electrochemically-triggered spatially and temporally resolved multi-component gels

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    Spatial control over gelation with low molecular weight gelators is possible using an electrochemically-driven pH triggering method. Gelation occurs at the electrode surface. We show here that composition control in multi-component low molecular weight hydrogels can also be achieved, allowing simultaneous spatial, temporal and compositional control

    Interventions to improve adherence to cardiovascular disease guidelines: a systematic review

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    Publisher's Version/PDFBackground Successful management of cardiovascular disease (CVD) is impaired by poor adherence to clinical practice guidelines. The objective of our review was to synthesize evidence about the effectiveness of interventions that target healthcare providers to improve adherence to CVD guidelines and patient outcomes. Methods We searched PubMed, EMBASE, Cochrane Library, PsycINFO, Web of Science and CINAHL databases from inception to June 2014, using search terms related to adherence and clinical practice guidelines. Studies were limited to randomized controlled trials testing an intervention to improve adherence to guidelines that measured both a patient and adherence outcome. Descriptive summary tables were created from data extractions. Meta-analyses were conducted on clinically homogeneous comparisons, and sensitivity analyses and subgroup analyses were carried out where possible. GRADE summary of findings tables were created for each comparison and outcome. Results and Discussion We included 38 RCTs in our review. Interventions included guideline dissemination, education, audit and feedback, and academic detailing. Meta-analyses were conducted for several outcomes by intervention type. Many comparisons favoured the intervention, though only the adherence outcome for the education intervention showed statistically significant improvement compared to usual care (standardized mean difference = 0.58 [95 % confidence interval 0.35 to 0.8]). Conclusions Many interventions show promise to improve practitioner adherence to CVD guidelines. The quality of evidence and number of trials limited our ability to draw conclusions.RAJ received funding from the DMRF Leo Alexander Summer Research Studentship. JAH held funding from the Nova Scotia Health Research Foundation to support local systematic review activities. MJT and GHC received funding through the RIM summer research program. CVZ has received a research grant through Boehringer-Ingelheim. All funding bodies had no influence on the conception, design or interpretation of dat

    Experiences of using the Theoretical Domains Framework across diverse clinical environments: a qualitative study

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    This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.phpBACKGROUND: The Theoretical Domains Framework (TDF) is an integrative framework developed from a synthesis of psychological theories as a vehicle to help apply theoretical approaches to interventions aimed at behavior change. PURPOSE: This study explores experiences of TDF use by professionals from multiple disciplines across diverse clinical settings. METHODS: Mixed methods were used to examine experiences, attitudes, and perspectives of health professionals in using the TDF in health care implementation projects. Individual interviews were conducted with ten health care professionals from six disciplines who used the TDF in implementation projects. Deductive content and thematic analysis were used. RESULTS: Three main themes and associated subthemes were identified including: 1) reasons for use of the TDF (increased confidence, broader perspective, and theoretical underpinnings); 2) challenges using the TDF (time and resources, operationalization of the TDF) and; 3) future use of the TDF. CONCLUSION: The TDF provided a useful, flexible framework for a diverse group of health professionals working across different clinical settings for the assessment of barriers and targeting resources to influence behavior change for implementation projects. The development of practical tools and training or support is likely to aid the utility of TDF

    Mapping the UK research & innovation landscape: Energy & development

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    The UK is already a major player in terms of research and innovation into low carbon transitions within the countries of the developing world. However, there are significant opportunities for the UK to enhance its presence within these markets whilst also making a major contribution to meeting international development targets and climate commitments. At the core of the research analysed in the report is that it reflects disparate, research initiatives funded with different research/innovation targets in mind; much latent strength in UK research for low carbon energy for development therefore is implicit in linkage possibilities enhancing systemic effectiveness, particularly by cross-fertilizing innovations taking place in the private sector. Gaps and weaknesses are reflected as much in the lack of collaborative initiatives and ‘siloization’ as in the absence of actual research/funding. The Low Carbon Energy for Development Network (LCEDN) is currently taking the initiative in one aspect of this through the provision of a programme of capacity building and partnership activities to support the development of DfID’s Transforming Energy Access research initiative. What is required of UK energy for development research for the purposes of building a functional system, however, is that the discrete areas of research outlined in this report be re-assembled as coherent, overall research narratives addressing the apparent contradiction of increasing energy access whilst transitioning to the low-carbon economy. Part of this work involves identifying the state and dynamics of UK research capacity in this sector, facilitating greater integration between research funders active in this area, evaluating gaps and key research needs and mapping potential future directions for research interventions and collaborations that build on, and develop, existing UK research capacity. It is expected that this will lead to a range of UK-led energy innovations developed, tested and scaled across developing countries by 2020. The much-needed harmonization of energy access and low carbon transition as a UK research theme however has ultimately to be created out of rethinking research fields from a combination of existing research, plus demand known to be ‘out there’ but which has yet to enter the field of vision of research-funders. This report presents the first part of this work with an overview of current UK research and innovation capacity in a widely defined ‘Energy and International Development’ research area. It identifies key institutions and research centres, thematic areas of excellence, research funding trends over the last decade, emerging research themes plus an overview of grant funding for innovation on the ground. A number of key areas/questions for potential further development of UK research and innovation capacity have been identified and are up for discussion and consultation. The work has been undertaken by LCEDN in partnership with the Knowledge Transfer Network, Energy 4 Impact and IOD PARC

    Prices and availability of locally produced and imported medicines in Ethiopia and Tanzania

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    Background: To assess the effect of policies supporting local medicine production to improve access to medicines. Methods: We adapted the WHO/HAI instruments measuring medicines availability and prices to differentiate local from imported products, then pilot tested in Ethiopia and Tanzania. In each outlet, prices were recorded for all products in stock for medicines on a country-specific list. Government procurement prices were also collected. Prices were compared to an international reference and expressed as median price ratios (MPR). Results: The Ethiopian government paid more for local products (median MPR = 1.20) than for imports (median MPR = 0.84). Eight of nine medicines procured as both local and imported products were cheaper when imported. Availability was better for local products compared to imports, in the public (48% vs. 19%, respectively) and private (54% vs. 35%, respectively) sectors. Patient prices were lower for imports in the public sector (median MPR = 1.18[imported] vs. 1.44[local]) and higher in the private sector (median MPR = 5.42[imported] vs. 1.85[local]). In the public sector, patients paid 17% and 53% more than the government procurement price for local and imported products, respectively. The Tanzanian government paid less for local products (median MPR = 0.69) than imports (median MPR = 1.34). In the public sector, availability of local and imported products was 21% and 32% respectively, with patients paying slightly more for local products (median MPR = 1.35[imported] vs. 1.44[local]). In the private sector, local products were less available (21%) than imports (70%) but prices were similar (median MPR = 2.29[imported] vs. 2.27[local]). In the public sector, patients paid 135% and 65% more than the government procurement price for local and imported products, respectively. Conclusions: Our results show how local production can affect availability and prices, and how it can be influenced by preferential purchasing and mark-ups in the public sector. Governments need to evaluate the impact of local production policies, and adjust policies to protect patients from paying more for local products.Scopu

    Effect of promoter architecture on the cell-to-cell variability in gene expression

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    According to recent experimental evidence, the architecture of a promoter, defined as the number, strength and regulatory role of the operators that control the promoter, plays a major role in determining the level of cell-to-cell variability in gene expression. These quantitative experiments call for a corresponding modeling effort that addresses the question of how changes in promoter architecture affect noise in gene expression in a systematic rather than case-by-case fashion. In this article, we make such a systematic investigation, based on a simple microscopic model of gene regulation that incorporates stochastic effects. In particular, we show how operator strength and operator multiplicity affect this variability. We examine different modes of transcription factor binding to complex promoters (cooperative, independent, simultaneous) and how each of these affects the level of variability in transcription product from cell-to-cell. We propose that direct comparison between in vivo single-cell experiments and theoretical predictions for the moments of the probability distribution of mRNA number per cell can discriminate between different kinetic models of gene regulation.Comment: 35 pages, 6 figures, Submitte

    Metaphors we die by? Geoengineering, metaphors and the argument from catastrophe

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    Geoeengineering the climate by reflecting sunlight or extracting carbon dioxide from the atmosphere has attracted increasing attention from natural scientists, social scientists, policy makers and the media. This article examines promotional discourse related to geoengineering from the 1980s to 2010. It asks in particular how this option for dealing with the problems posed by climate change were framed through the use of conceptual and discourse metaphors and whether one can argue that these are metaphors we ‘live by’ or metaphors we might ‘die by’. Findings show that an overarching argument from catastrophe was bolstered by three conceptual master-metaphors, namely The Planet is a body, The Planet is a machine and The planet is a patient/addict, linked to a variety of discourse metaphors, older conceptual metaphors and clichés. This metaphorical landscape began to shift while the article was being written and will have to be closely monitored in the future
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