508 research outputs found

    Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

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    A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone production as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones

    Learning in the Palaver Hut: The ‘Africa Study Visit’ as teaching tool.

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    noThe aim of this article is to assess the experiential learning environment of the African Study Visit (ASV). It presents a theoretically grounded analysis of the ASV. Although field visits are not a new phenomenon within Higher Education, they seem, but with few exceptions, to be considered as an add-on teaching method. By drawing from the experiential learning literature, we demonstrate that there are sound pedagogical reasons for incorporating field visits like the ASV into the curriculum as stand-alone components. Thus, the original contribution of this article is to place the ASV within the experiential learning literature such that the theoretical, practical and conceptual benefits for students are understood. Its significance is that this article offers a set of practices from an experiential learning perspective that can be used for deepening the levels of comprehension of political issues in Africa for international studies students

    Improving education in primary care: development of an online curriculum using the blended learning model

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    <p>Abstract</p> <p>Background</p> <p>Standardizing the experiences of medical students in a community preceptorship where clinical sites vary by geography and discipline can be challenging. Computer-assisted learning is prevalent in medical education and can help standardize experiences, but often is not used to its fullest advantage. A blended learning curriculum combining web-based modules with face-to-face learning can ensure students obtain core curricular principles.</p> <p>Methods</p> <p>This course was developed and used at The Case Western Reserve University School of Medicine and its associated preceptorship sites in the greater Cleveland area. Leaders of a two-year elective continuity experience at the Case Western Reserve School of Medicine used adult learning principles to develop four interactive online modules presenting basics of office practice, difficult patient interviews, common primary care diagnoses, and disease prevention. They can be viewed at <url>http://casemed.case.edu/cpcp/curriculum</url>. Students completed surveys rating the content and technical performance of each module and completed a Generalist OSCE exam at the end of the course.</p> <p>Results</p> <p>Participating students rated all aspects of the course highly; particularly those related to charting and direct patient care. Additionally, they scored very well on the Generalist OSCE exam.</p> <p>Conclusion</p> <p>Students found the web-based modules to be valuable and to enhance their clinical learning. The blended learning model is a useful tool in designing web-based curriculum for enhancing the clinical curriculum of medical students.</p

    STORIES Statement: publication standards for healthcare education evidence synthesis

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    Fully copy of the STORIES statement - a checklist of reporting guidance for health education evidence synthesis Structured approach for Reporting In health education of Evidence Synthesis Background Evidence synthesis techniques in healthcare education have been enhanced through the activities of experts in the field and the Best Evidence Medical Education (BEME) collaborative. Despite this, significant heterogeneity in techniques and reporting of healthcare education systematic review still exist and limit the usefulness of such reports. The aim of this project was to produce the STORIES (STructured apprOach to the Reporting In healthcare education of Evidence Synthesis) statement to offer a guide for reporting evidence synthesis in health education for use by authors and journal editors. Methods A review of existing published evidence synthesis consensus statements was undertaken. A modified Delphi process was used. In stage one, expert participants were asked to state whether common existing items identified were relevant, to suggest relevant texts and specify any items they feel should be included. The results were analysed and a second stage commenced where all synthesised items were presented and participants asked to state whether they should be included or amend as needed. After further analysis, the full statement was sent for final review and comment. Results Nineteen experts participated in the panel from 35 invitations. Thirteen text sources were proposed, six existing items amended and twelve new items synthesised. After stage two, 25 amended consensus items were proposed for inclusion. The final statement contains several items unique to this context, including description of relevant conceptual frameworks or theoretical constructs, description of qualitative methodologies with rationale for their choice and presenting the implications for educators in practice of the results obtained. Conclusions An international expert panel has agreed upon a consensus statement of 25 items for the reporting of evidence synthesis within healthcare education. This unique set of items is focused on context, rather than a specific methodology. This statement can be used for those writing for publication and reviewing such manuscripts to ensure reporting supports and best informs the wider healthcare education community

    Detection of phosphatidylserine with a modified polar head group in human keratinocytes exposed to the radical generator AAPH

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    Phosphatidylserine (PS) is preferentially located in the inner leaflet of the cell membrane, and translocation of PS oxidized in fatty acyl chains to the outside of membrane has been reported as signaling to macrophage receptors to clear apoptotic cells. It was recently shown that PS can be oxidized in serine moiety of polar head-group. In the present work, a targeted lipidomic approach was applied to detecting OxPS modified at the polar head-group in keratinocytes that were exposed to the radical generator AAPH. Glycerophosphoacetic acid derivatives (GPAA) were found to be the major oxidation products of OxPS modified at the polar head-group during oxidation induced by AAPH-generated radicals, similarly to previous observations for the oxidation induced by OH radical. The neutral loss scan of 58Da and a novel precursor ion scan of m/z 137.1 (HOPO3CH2COOH) allowed the recognition of GPAA derivatives in the total lipid extracts obtained from HaCaT cells treated with AAPH. The positive identification of serine head group oxidation products in cells under controlled oxidative conditions opens new perspectives and justifies further studies in other cellular environments in order to understand fully the role of PS polar head-group oxidation in cell homeostasis and disease

    Boreal forest floor greenhouse gas emissions across a Pleurozium schreberi-dominated, wildfire-disturbed chronosequence

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    The boreal forest is a globally critical biome for carbon cycling. Its forests are shaped by wildfire events that affect ecosystem properties and climate feedbacks including greenhouse gas (GHG) emissions. Improved understanding of boreal forest floor processes is needed to predict the impacts of anticipated increases in fire frequency, severity, and extent. In this study, we examined relationships between time since last wildfire (TSF), forest floor soil properties, and GHG emissions (CO2, CH4, N2O) along a Pleurozium schreberi-dominated chronosequence in mid- to late succession located in northern Sweden. Over three growing seasons in 2012–2014, GHG flux measurements were made in situ and samples were collected for laboratory analyses. We predicted that P. schreberi-covered forest floor GHG fluxes would be related to distinct trends in the soil properties and microbial community along the wildfire chronosequence. Although we found no overall effect of TSF on GHG emissions, there was evidence that soil C/N, one of the few properties to show a trend with time, was inversely linked to ecosystem respiration. We also found that local microclimatic conditions and site-dependent properties were better predictors of GHG fluxes than TSF. This shows that site-dependent co-variables (that is, forest floor climate and plant-soil properties) need to be considered as well as TSF to predict GHG emissions as wildfires become more frequent, extensive and severe

    Carbon partitioning between oil and carbohydrates in developing oat (Avena sativa L.) seeds

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    Cereals accumulate starch in the endosperm as their major energy reserve in the grain. In most cereals the embryo, scutellum, and aleurone layer are high in oil, but these tissues constitute a very small part of the total seed weight. However, in oat (Avena sativa L.) most of the oil in kernels is deposited in the same endosperm cells that accumulate starch. Thus oat endosperm is a desirable model system to study the metabolic switches responsible for carbon partitioning between oil and starch synthesis. A prerequisite for such investigations is the development of an experimental system for oat that allows for metabolic flux analysis using stable and radioactive isotope labelling. An in vitro liquid culture system, developed for detached oat panicles and optimized to mimic kernel composition during different developmental stages in planta, is presented here. This system was subsequently used in analyses of carbon partitioning between lipids and carbohydrates by the administration of 14C-labelled sucrose to two cultivars having different amounts of kernel oil. The data presented in this study clearly show that a higher amount of oil in the high-oil cultivar compared with the medium-oil cultivar was due to a higher proportion of carbon partitioning into oil during seed filling, predominantly at the earlier stages of kernel development

    The TIP30 Protein Complex, Arachidonic Acid and Coenzyme A Are Required for Vesicle Membrane Fusion

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    Efficient membrane fusion has been successfully mimicked in vitro using artificial membranes and a number of cellular proteins that are currently known to participate in membrane fusion. However, these proteins are not sufficient to promote efficient fusion between biological membranes, indicating that critical fusogenic factors remain unidentified. We have recently identified a TIP30 protein complex containing TIP30, acyl-CoA synthetase long-chain family member 4 (ACSL4) and Endophilin B1 (Endo B1) that promotes the fusion of endocytic vesicles with Rab5a vesicles, which transport endosomal acidification enzymes vacuolar (H+)-ATPases (V-ATPases) to the early endosomes in vivo. Here, we demonstrate that the TIP30 protein complex facilitates the fusion of endocytic vesicles with Rab5a vesicles in vitro. Fusion of the two vesicles also depends on arachidonic acid, coenzyme A and the synthesis of arachidonyl-CoA by ACSL4. Moreover, the TIP30 complex is able to transfer arachidonyl groups onto phosphatidic acid (PA), producing a new lipid species that is capable of inducing close contact between membranes. Together, our data suggest that the TIP30 complex facilitates biological membrane fusion through modification of PA on membranes
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