403 research outputs found

    Phylogenetic Beta Diversity Metrics, Trait Evolution and Inferring the Functional Beta Diversity of Communities

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    The beta diversity of communities along gradients has fascinated ecologists for decades. Traditionally such studies have focused on the species composition of communities, but researchers are becoming increasingly interested in analyzing the phylogenetic composition in the hope of achieving mechanistic insights into community structure. To date many metrics of phylogenetic beta diversity have been published, but few empirical studies have been published. Further inferences made from such phylogenetic studies critically rely on the pattern of trait evolution. The present work provides a study of the phylogenetic dissimilarity of 96 tree communities in India. The work compares and contrasts eight metrics of phylogenetic dissimilarity, considers the role of phylogenetic signal in trait data and shows that environmental distance rather than spatial distance is the best correlate of phylogenetic dissimilarity in the study system

    Comparison of different dosing regimens (once weekly vs. twice weekly, and once weekly vs. once every two weeks) with epoetin delta in patients with chronic kidney disease: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Anaemia is a common complication of chronic kidney disease and prevalence increases with declining renal function. Renal anaemia has significant implications for the well-being and quality of life of patients and impacts on morbidity and mortality. Anaemia can be well managed by therapy with erythropoiesis-stimulating agents (ESAs). Previous clinical trials have shown that the only human cell-line-derived ESA, epoetin delta, is well tolerated and effective in maintaining haemoglobin levels in anaemic patients with chronic kidney disease. The half-life of epoetin delta suggests that administration of this agent is feasible once weekly and once every two weeks. We report on the design and rationale of a trial to compare once weekly <it>vs</it>. twice weekly, and once weekly <it>vs</it>. once every two weeks dosing of epoetin delta.</p> <p>Design and methods</p> <p>This is a randomized, open-label, multicentre trial. Patients aged 18 years or above with chronic kidney disease (Stages 3–5) are eligible to enter this trial. Two groups of patients form the trial population, those naïve to ESA therapy and those previously stable on ESA therapy. There are two primary objectives of this trial: 1) to demonstrate non-inferiority between twice weekly and once weekly dosing of epoetin delta in previously naïve patients (assessed by haemoglobin at Week 24); 2) to demonstrate non-inferiority between once weekly and once every two weeks dosing in previously stable patients (assessed by average haemoglobin over Weeks 16–24). Among the secondary analyses will be assessments of haematocrit, number(%) of patients meeting predefined targets for haemoglobin and haematocrit levels, and comparisons of average dose. All patients will receive study medication for 24 weeks and dose will be adjusted according to a predefined algorithm to achieve and maintain haemoglobin ≥ 11 g/dL. All patients completing this trial are eligible to enter a 2-year follow-up study to enable monitoring of emergent adverse events, anti-erythropoietin antibody responses, maintenance of efficacy and changes in diabetic retinopathy status.</p> <p>Discussion</p> <p>To our knowledge, this trial is the first to randomize ESA-naïve patients to different dosing regimens of the same ESA. Data generated will help in guiding the most appropriate dosing frequency for epoetin delta, particularly in those patients new to epoetin delta therapy.</p> <p>Trial registration</p> <p><b>ClinicalTrials.gov: </b>NCT00450333</p

    Expression of cytokine and chemokine mRNA and secretion of tumor necrosis factor-α by gallbladder epithelial cells: Response to bacterial lipopolysaccharides

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    BACKGROUND: In addition to immune cells, many other cell types are known to produce cytokines. Cultured normal mouse gallbladder epithelial cells, used as a model system for gallbladder epithelium, were examined for their ability to express the mRNA of various cytokines and chemokines in response to bacterial lipopolysaccharide. The synthesis and secretion of the tumor necrosis factor-α (TNF-α) protein by these cells was also measured. RESULTS: Untreated mouse gallbladder cells expressed mRNA for TNF-α, RANTES, and macrophage inflammatory protein-2 (MIP-2). Upon treatment with lipopolysaccharide, these cells now produced mRNA for Interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1 (MCP-1), and showed increased expression of TNF-α and MIP-2 mRNA. Untreated mouse gallbladder cells did not synthesize TNF-α protein; however, they did synthesize and secrete TNF-α upon treatment with lipopolysaccharide. METHODS: Cells were treated with lipopolysaccharides from 3 strains of bacteria. Qualitative and semi-quantitative RT-PCR, using cytokine or chemokine-specific primers, was used to measure mRNA levels of TNFα, IL-1β, IL-6, IL-10, KC, RANTES, MCP-1, and MIP-2. TNF-α protein was measured by immunoassays. CONCLUSION: This research demonstrates that gallbladder epithelial cells in response to lipopolysaccharide exposure can alter their cytokine and chemokine RNA expression pattern and can synthesize and secrete TNFα protein. This suggests a mechanism whereby gallbladder epithelial cells in vivo may mediate gallbladder secretory function, inflammation and diseases in an autocrine/paracrine fashion by producing and secreting cytokines and/or chemokines during sepsis

    Radiofrequency-based treatment in therapy-related clinical practice – a narrative review. Part I : acute conditions

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in Physical Therapy Reviews on 24 June 2015, available online at: https://www.tandfonline.com/doi/full/10.1179/1743288X15Y.0000000016Background: Radiofrequency electromagnetic field (RFEMF or simply RF)-based electrophysical agents (EPAs) have been employed in therapy-related clinical practice for several decades. They are used to reduce pain and inflammation and enhance tissue healing. Although these agents have generally become less popular in contemporary therapy practice, surveys have shown that some of these modalities are still reasonably widely used. Objective: To review the evidence for the use of non-invasive low frequency RFs (30 kHz–30 MHz) in therapy-related clinical practice. Major findings: All peer reviewed therapy-related clinical studies published in English and concerning low frequency RF were sought. Identified literature was divided into acute and chronic segments based on their clinical area and analysed to assess the volume and scope of current evidence. The studies on acute conditions were reviewed in detail for this paper. One hundred twenty clinical studies were identified, of which 30 related to acute conditions. The majority of studies employed Pulsed Shortwave Therapy (PSWT). Twenty-two studies out of 30 were related to conditions of pain and inflammation, seven to tissue healing and one to acute pneumothorax. No studies were identified on frequencies other than shortwave. Conclusions: Evidence for and against RF-based therapy is available. There is reasonable evidence in support of PSWT to alleviate postoperative pain and promote postoperative wound healing. Evidence for other acute conditions is sparse and conflicting. A general lack of research emphasis in the non-shortwave RF band is evident, with studies on acute conditions almost non-existent. Further and wider research in this area is warranted.Peer reviewe

    A reflective perspective on the challenges facing research-led teaching in the performing and creative arts

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    This article provides a reflective perspective on the role that research-led teaching plays in the development of future arts workers in higher education. It explores the challenges faced by lecturers developing curricula in the performing and creative arts and argues that the increasing focus on employability can conflict with universities’ traditional aim of developing conceptual and critical thinkers. The article charges that the UK’s higher education sector is rapidly transforming itself into a two-tier system, which is serving to dichotomise vocational and academic learning even further. It concludes with a call for universities, students and employers to reject the false dichotomy between vocational and academic learning and perceive education in a more holistic, longitudinal sense, which might in turn develop more balanced graduates who excel in networked knowledge, conceptual and theoretical imagination and critical, lateral thinking
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