444 research outputs found

    Comprehension as social and intellectual practice: Rebuilding curriculum in low socioeconomic and cultural minority schools

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    This article reframes the concept of comprehension as a social and intellectual practice. It reviews current approaches to reading instruction for linguistically and culturally diverse and low socioeconomic students, noting an emphasis on comprehension as autonomous skills. The Four Resources model (Freebody & Luke, 1990) is used to make the case for the integration of comprehension instruction with an emphasis on student cultural and community knowledge, and substantive intellectual and sociocultural content in elementary school curricula. Illustrations are drawn from research underway on the teaching of literacy in primary schools in low SES communities

    Bone mineral density, rib pain and other features of the female athlete triad in elite lightweight rowers

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    Objective: To determine bone mineral density (BMD) and the associations among BMD, menstrual history, disordered eating (DE), training history, intentional weight loss (IWL) and rib pain for the first time in female lightweight rowers. Setting: 9 lightweight rowing clubs, UK. Participants: 29 Caucasian female lightweight rowers volunteered. 21 (12 active, 9 retired) completed the study. Inclusion criteria: female lightweight rowers aged over 18 years. Exclusion criteria: participants with a history of bone disease, used medications known to influence BMD or if they were pregnant, lactating or postmenopausal. Main outcome measures: Dual-energy X-ray absorptiometry measured total body (TB) composition and BMD at the spine, femoral neck (FN), radius and TB. DE, oligomenorrhoea/amenorrhoea years; rib pain and training history. Results: DE was reported in six of the rowers. The active with DE started rowing younger (p<0.05) than those without, and their amount of IWL was associated with Eating Attitudes Test-26 score (p<0.05). Some participants reported a history of oligomenorrhoea/amenorrhoea 17 (76%) and/or rib pain 7 (32%) with those with rib pain having lower spine and TB Z-scores (p<0.05) than those without. Those with oligomenorrhoea/amenorrhoea had lower spine Z-scores (p<0.01) than those without. Twelve participants had low BMD; three at spine; one at FN; and eight at radius. Thirteen per cent of mean total training hours (18.6±9.1 h/week) were spent strength training (2.4±2.2 h/week). Conclusions: Upper body exercises incorporating multidimensional high peak bone strain were not reported and may need to be considered in their strength training to improve radial BMD. Results suggest IWL and high level training at a young age increases the likelihood of DE and there may be a lack of quality nutritional support for these athletes. Thus, multidisciplinary sport science support should be offered at a young age and perhaps also to consider changing the weight rules to prevent the development of the Triad

    A survey on parallel and distributed Multi-Agent Systems

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    International audienceSimulation has become an indispensable tool for researchers to explore systems without having recourse to real experiments. Depending on the characteristics of the modeled system, methods used to represent the system may vary. Multi-agent systems are, thus, often used to model and simulate complex systems. Whatever modeling type used, increasing the size and the precision of the model increases the amount of computation, requiring the use of parallel systems when it becomes too large. In this paper, we focus on parallel platforms that support multi-agent simulations. Our contribution is a survey on existing platforms and their evaluation in the context of high performance computing. We present a qualitative analysis, mainly based on platform properties, then a performance comparison using the same agent model implemented on each platform

    Phylotastic! Making Tree-of-Life Knowledge Accessible, Reusable and Convenient

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    Scientists rarely reuse expert knowledge of phylogeny, in spite of years of effort to assemble a great "Tree of Life" (ToL). A notable exception involves the use of Phylomatic, which provides tools to generate custom phylogenies from a large, pre-computed, expert phylogeny of plant taxa. This suggests great potential for a more generalized system that, starting with a query consisting of a list of any known species, would rectify non-standard names, identify expert phylogenies containing the implicated taxa, prune away unneeded parts, and supply branch lengths and annotations, resulting in a custom phylogeny suited to the user's needs. Such a system could become a sustainable community resource if implemented as a distributed system of loosely coupled parts that interact through clearly defined interfaces. Results: With the aim of building such a "phylotastic" system, the NESCent Hackathons, Interoperability, Phylogenies (HIP) working group recruited 2 dozen scientist-programmers to a weeklong programming hackathon in June 2012. During the hackathon (and a three-month follow-up period), 5 teams produced designs, implementations, documentation, presentations, and tests including: (1) a generalized scheme for integrating components; (2) proof-of-concept pruners and controllers; (3) a meta-API for taxonomic name resolution services; (4) a system for storing, finding, and retrieving phylogenies using semantic web technologies for data exchange, storage, and querying; (5) an innovative new service, DateLife.org, which synthesizes pre-computed, time-calibrated phylogenies to assign ages to nodes; and (6) demonstration projects. These outcomes are accessible via a public code repository (GitHub.com), a website (www.phylotastic.org), and a server image. Conclusions: Approximately 9 person-months of effort (centered on a software development hackathon) resulted in the design and implementation of proof-of-concept software for 4 core phylotastic components, 3 controllers, and 3 end-user demonstration tools. While these products have substantial limitations, they suggest considerable potential for a distributed system that makes phylogenetic knowledge readily accessible in computable form. Widespread use of phylotastic systems will create an electronic marketplace for sharing phylogenetic knowledge that will spur innovation in other areas of the ToL enterprise, such as annotation of sources and methods and third-party methods of quality assessment.NESCent (the National Evolutionary Synthesis Center)NSF EF-0905606iPlant Collaborative (NSF) DBI-0735191Biodiversity Synthesis Center (BioSync) of the Encyclopedia of LifeComputer Science

    Plutonium Migration during the Leaching of Cemented Radioactive Waste Sludges

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    One of the most challenging components of the UK nuclear legacy is Magnox sludge, arising from the corrosion of Mg alloy-clad irradiated metallic U fuel that has been stored in high pH ponds. The sludges mainly comprise Mg hydroxide and carbonate phases, contaminated with fission products and actinides, including Pu. Cementation and deep geological disposal is one option for the long-term management of this material, but there is a need to understand how Pu may be leached from the waste, if it is exposed to groundwater. Here, we show that cemented Mg(OH)2 powder prepared with Pu(IV)aq is altered on contact with water to produce a visibly altered ‘leached zone’, which penetrates several hundred microns into the sample. In turn, this zone shows slow leaching of Pu, with long-term leaching rates between 1.8–4.4 × 10−5% of total Pu per day. Synchrotron micro-focus X-ray fluorescence mapping identified decreased Pu concentration within the ‘leached zone’. A comparison of micro-focus X-ray absorption spectroscopy (µ-XAS) spectra collected across both leached and unleached samples showed little variation, and indicated that Pu was present in a similar oxidation state and coordination environment. Fitting of the XANES spectra between single oxidation state standards and EXAFS modeling showed that Pu was present as a mixture of Pu(IV) and Pu(V). The change in Pu oxidation from the stock solution suggests that partial Pu oxidation occurred during sample ageing. Similarity in the XAS spectra from all samples, with different local chemistries, indicated that the Pu oxidation state was not perturbed by macro-scale variations in cement chemistry, surface oxidation, sample aging, or the leaching treatment. These experiments have demonstrated the potential for leaching of Pu from cementitious waste forms, and its underlying significance requires further investigation

    Plutonium Migration during the Leaching of Cemented Radioactive Waste Sludges

    Get PDF
    One of the most challenging components of the UK nuclear legacy is Magnox sludge, arising from the corrosion of Mg alloy-clad irradiated metallic U fuel that has been stored in high pH ponds. The sludges mainly comprise Mg hydroxide and carbonate phases, contaminated with fission products and actinides, including Pu. Cementation and deep geological disposal is one option for the long-term management of this material, but there is a need to understand how Pu may be leached from the waste, if it is exposed to groundwater. Here, we show that cemented Mg(OH)2 powder prepared with Pu(IV)aq is altered on contact with water to produce a visibly altered ‘leached zone’, which penetrates several hundred microns into the sample. In turn, this zone shows slow leaching of Pu, with long-term leaching rates between 1.8–4.4 × 10−5% of total Pu per day. Synchrotron micro-focus X-ray fluorescence mapping identified decreased Pu concentration within the ‘leached zone’. A comparison of micro-focus X-ray absorption spectroscopy (µ-XAS) spectra collected across both leached and unleached samples showed little variation, and indicated that Pu was present in a similar oxidation state and coordination environment. Fitting of the XANES spectra between single oxidation state standards and EXAFS modeling showed that Pu was present as a mixture of Pu(IV) and Pu(V). The change in Pu oxidation from the stock solution suggests that partial Pu oxidation occurred during sample ageing. Similarity in the XAS spectra from all samples, with different local chemistries, indicated that the Pu oxidation state was not perturbed by macro-scale variations in cement chemistry, surface oxidation, sample aging, or the leaching treatment. These experiments have demonstrated the potential for leaching of Pu from cementitious waste forms, and its underlying significance requires further investigation

    Primary trabeculectomy versus primary glaucoma eye drops for newly diagnosed advanced glaucoma:TAGS RCT

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    Funding Information: Declared competing interests of authors: Anthony J King declares receiving honoraria payments from Thea Pharmaceutical (Keele, UK) and Allergan Pharmaceutical (Dublin, Ireland) for speaking at educational meetings. Augusto Azuara-Blanco declares membership of the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Prioritisation Committee B (2020–present). Jennifer Burr declares membership of the NIHR HTA Clinical Evaluations and Trials Committee (2010–14). David Garway-Heath reports grants from NIHR for the HTA programme 12/35/38 during the conduct of the study; personal fees from Aerie Pharmaceuticals (Bedminster, NJ, USA), Allergan Pharmaceuticals, Bausch & Lomb (Rochester, NY, USA), Omikron (Beirut, Lebanon) and OptoVue (Fremont, CA, USA); personal fees and non-financial support from Carl Zeiss Meditec (Jena, Germany) and CenterVue (Padova, Italy); grants from Pfizer Inc. (New York, NY, USA) and Alcon Research Institute (Geneva, Switzerland); grants and personal fees from Santen Pharmaceutical (Osaka, Japan); and research equipment from Heidelberg Engineering (Heidelberg, Germany) and Topcon (Tokyo, Japan) outside the submitted work. David Garway-Heath also declared membership of the NIHR HTA Clinical Evaluations and Trials Committee (2014–17). John Norrie reports grants from University of Aberdeen and University of Edinburgh during the conduct of the study; and reports being a past and present member of the following: HTA Commissioning Sub-Board (EOI), NIHR Clinical Trials Unit Standing Advisory Committee, NIHR HTA and Efficacy and Mechanism Evaluation (EME) Editorial Board, Pre-Exposure Prophylaxis Impact Review Panel, EME Strategy Advisory Committee, EME Funding Committee Members, EME Funding Committee Sub-Group Remit and Comp Check, HTA General Committee, HTA Funding Committee Policy Group (formerly CSG) and the HTA Commissioning Committee. John Norrie also reports the HTA Post-funding Committee Teleconference (2016–19) and Covid Reviewing 2020. Luke Vale reports grants from NIHR HTA programme 12/35/38 during the conduct of the study. Luke Vale was also a member of the NIHR HTA Clinical Trials and Evaluation Panel from 2014 to 2018. John M Sparrow reports grants from NIHR HTA programme 12/35/38 during the conduct of the study, and was the previous chairperson of the National Institute for Health and Care Excellence Glaucoma Guideline Committee guideline published in 2017. Keith Barton reports personal fees from Allergan Pharmaceuticals, Alcon Pharmaceuticals, Laboratoires Thea (Clermont-Ferrand, France), EyeTechCare (Rillieux-la-Pape, France), Glaukos (San Clemente, CA, USA), Kowa Pharmaceuticals (Montgomery, AL, USA), Ivantis Inc. (Irvine, CA, USA), pH Pharma (South San Francisco, CA, USA), iStar Medical (Wavre, Belgium), Radiance Therapeutics (Tucson, AZ, USA) and EyeD Pharma (Liège, Belgium), grants from Allergan and Laboratoires Thea, stock from Vision Medical Events Ltd (London, UK), International Glaucoma Surgery Registry (London, UK) and MedEther Ophthalmology (London, UK), and a patent from Advanced Ophthalmic Implants outside the submitted work. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 72. See the NIHR Journals Library website for further project information. The research reported in this issue of the journal was funded by the HTA programme as project number 12/35/38. The contractual start date was in January 2014. The draft report began editorial review in February 2020 and was accepted for publication in December 2020. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.Peer reviewedPublisher PD
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