3,685 research outputs found

    Evaluating the impact and use of Transparent Reporting of Evaluations with Non-randomised Designs (TREND) reporting guidelines.

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    notes: PMCID: PMC3533093Freely available Open Access paper. Cite published version at: doi:10.1136/bmjopen-2012-002073INTRODUCTION: Accurate and full reporting of evaluation of interventions in health research is needed for evidence synthesis and informed decision-making. Evidence suggests that biases and incomplete reporting affect the assessment of study validity and the ability to include this data in secondary research. The Transparent Reporting of Evaluations with Non-randomised Designs (TREND) reporting guideline was developed to improve the transparency and accuracy of the reporting of behavioural and public health evaluations with non-randomised designs. Evaluations of reporting guidelines have shown that they can be effective in improving reporting completeness. Although TREND occupies a niche within reporting guidelines, and despite it being 8 years since publication, no study yet has assessed its impact on reporting completeness or investigated what factors affect its use by authors and journal editors. This protocol describes two studies that aim to redress this. METHODS AND ANALYSIS: Study 1 will use an observational design to examine the uptake and use of TREND by authors, and by journals in their instructions to authors. A comparison of reporting completeness and study quality of papers that do and do not use TREND to inform reporting will be made. Study 2 will use a cross-sectional survey to investigate what factors inhibit or facilitate authors' and journal editors' use of TREND. Semistructured interviews will also be conducted with a subset of authors and editors to explore findings from study 1 and the surveys in greater depth. ETHICS AND DISSEMINATION: These studies will generate evidence of how implementation and dissemination of the TREND guideline has affected reporting completeness in studies with experimental, non-randomised designs within behavioural and public health research. The project has received ethics approval from the Research Ethics Committee of the Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth

    Lessons from Genomic Profiling in AS

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    Strategies for Managing Large Online Classes

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    Online classroom instruction is an exciting technology and continues to draw the attention of students, instructors and administrators working or studying in educational settings. Large numbers of faculty are currently involved in teaching online or hybrid courses within their educational institutions. At the present time, very large online classes are usually defined as 150 students and above. Many instructors are now experimenting with making online learning options available to even larger audiences and online class sizes are increasing rapidly. This paper presents guidelines for managing large online courses. Among key elements important in meeting the needs of the distant learner through large online course design are: effective communication, use of teaching assistants and multiple sections, teaching techniques successful in large online sections and professional practice in the online classroom. This paper will discuss these elements and corresponding suggestions for the instructors of large to very large online courses

    Abundance and Sizes of Bay Scallops in Heterogeneous Habitats Along the Gulf Coast of Florida

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    Southern bay scallops (Argopecten irradians concentricus) form the basis of a recreational fishery along Florida\u27s Gulf Coast. Recent declines in scallop abundances have led to significant harvest restrictions. As a way to gain insight into influences on scallop abundances and size, surveys of bay scallops and coastal habitats were conducted in two relatively undisturbed, shallow estuaries along the north-central Gulf Coast of Florida. Scallop abundances did not vary significantly between years or between locations kilometers apart. Shell heights did vary significantly between years at locations kilometers apart; however, these differences were not consistently related to differences in chlorophyll concentrations in the water column or distributions of benthic habitat classes. At the 100-m scale within locations, scallops were not proportionally distributed across the major habitat classes (i.e., Syringodium filiforme, Thalassia testudinum, mixed seagrass assemblage, other seagrasses, and areas of no/low seagrass cover). In general, proportionately more scallops were observed in association with S. filiforme, T. testudinum, and mixed seagrass habitats. Bay scallops collected from S. filiforme and areas of no/low grass cover were consistently 1-3 mm larger than those collected from T. testudinum and mixed seagrass assemblages. These results suggest the importance of S. filiforme and T. testudinum as habitats for bay scallops. The results also point to the need for further investigation into possible functional differences among seagrass species that may influence the ecology of bay scallops at a small spatial scale and the need for closer examination of scallop movement that may allow for active habitat selection. The work presented here, plus further efforts to elucidate the drivers of small-scale differences in scallop abundances and sizes, will benefit managers who seek to enhance scallop fisheries or protect and restore coastal habitats

    The Effect of Sulfuric Acid Concentration on the Physical and Electrochemical Properties of Vanadyl Solutions

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    The effects of sulfuric acid concentration in VO2+ solutions were investigated via electrochemical methods and electron paramagnetic resonance. Viscosity of solutions containing 0.01 M VOSO4 in 0.1–7 M H2SO4 was measured. Diffusion coefficients were independently measured via electrochemical methods and EPR with excellent agreement between the techniques employed and literature values. Analysis of cyclic voltammograms suggest the oxidation of VO2+ to VO2+ is quasi-reversible at high H2SO4 concentrations (\u3e5 mol/L) and approaching irreversible at lower H2SO4 concentrations. Further analysis reveals a likely electrochemical/chemical (EC) mechanism where the H2SO4 facilitates the electrochemical step but hinders the chemical step. Fundamental insights of VO2+/H2SO4 solutions can lead to a more comprehensive understanding of the concentration effects in electrolyte solutions

    Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: Four new cases and a review of the evidence.

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    CBS deficient individuals undergoing betaine supplementation without sufficient dietary methionine restriction can develop severe hypermethioninemia and brain edema. Brain edema has also been observed in individuals with severe hypermethioninemia without concomitant betaine supplementation. We systematically evaluated reports from 11 published and 4 unpublished patients with CBS deficiency and from additional four cases of encephalopathy in association with elevated methionine. We conclude that, while betaine supplementation does greatly exacerbate methionine accumulation, the primary agent causing brain edema is methionine rather than betaine. Clinical signs of increased intracranial pressure have not been seen in patients with plasma methionine levels below 559 μmol/L but occurred in one patient whose levels did not knowingly exceed 972 μmol/L at the time of manifestation. While levels below 500 μmol/L can be deemed safe it appears that brain edema can develop with plasma methionine levels close to 1000 μmol/L. Patients with CBS deficiency on betaine supplementation need to be regularly monitored for concordance with their dietary plan and for plasma methionine concentrations. Recurrent methionine levels above 500 μmol/L should alert clinicians to check for clinical signs and symptoms of brain edema and review dietary methionine intake. Levels approaching 1000 μmol/L do increase the risk of complications and levels exceeding 1000 μmol/L, despite best dietetic efforts, should be acutely addressed by reducing the prescribed betaine dose

    Ultrastructural and functional analyses of recombinant influenza virus ribonucleoproteins suggest dimerization of nucleoprotein during virus amplification

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    8 pages, 7 figures.-- PMID: 10590102 [PubMed].-- PMCID: PMC111524.Full-text version available Open Access at PebMed Central: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=10590102Influenza virus ribonucleoproteins (RNPs) were reconstituted in vivo from cloned cDNAs expressing the three polymerase subunits, the nucleoprotein (NP), and short template RNAs. The structure of purified RNPs was studied by electron microscopy and image processing. Circular and elliptic structures were obtained in which the NP and the polymerase complex could be defined. Comparison of the structure of RNPs of various lengths indicated that each NP monomer interacts with approximately 24 nucleotides. The analysis of the amplification of RNPs with different lengths showed that those with the highest replication efficiency contained an even number of NP monomers, suggesting that the NP is incorporated as dimers into newly synthesized RNPs.J. Ortega was a fellow of Instituto de Estudios Turolenses. This work was supported by Programa Sectorial de Promoción General del Conocimiento (grants PB97-1160 and PB96-0818).Peer reviewe

    Quantitative evaluation of patient-specific conforming hexahedral meshes of abdominal aortic aneurysms and intraluminal thrombus generated from MRI

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    A novel method for generating patient-specific high quality conforming hexahedral meshes is presented. The meshes are directly obtained from the segmentation of patient magnetic resonance (MR) images of abdominal aortic aneu-rysms (AAA). The MRI permits distinguishing between struc-tures of interest in soft tissue. Being so, the contours of the lumen, the aortic wall and the intraluminal thrombus (ILT) are available and thus the meshes represent the actual anato-my of the patient?s aneurysm, including the layered morpholo-gies of these structures. Most AAAs are located in the lower part of the aorta and the upper section of the iliac arteries, where the inherent tortuosity of the anatomy and the presence of the ILT makes the generation of high-quality elements at the bifurcation is a challenging task. In this work we propose a novel approach for building quadrilateral meshes for each surface of the sectioned geometry, and generating conforming hexahedral meshes by combining the quadrilateral meshes. Conforming hexahedral meshes are created for the wall and the ILT. The resulting elements are evaluated on four patients? datasets using the Scaled Jacobian metric. Hexahedral meshes of 25,000 elements with 94.8% of elements well-suited for FE analysis are generated
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