794 research outputs found

    Classification of the extracellular fields produced by activated neural structures

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    BACKGROUND: Classifying the types of extracellular potentials recorded when neural structures are activated is an important component in understanding nerve pathophysiology. Varying definitions and approaches to understanding the factors that influence the potentials recorded during neural activity have made this issue complex. METHODS: In this article, many of the factors which influence the distribution of electric potential produced by a traveling action potential are discussed from a theoretical standpoint with illustrative simulations. RESULTS: For an axon of arbitrary shape, it is shown that a quadrupolar potential is generated by action potentials traveling along a straight axon. However, a dipole moment is generated at any point where an axon bends or its diameter changes. Next, it is shown how asymmetric disturbances in the conductivity of the medium surrounding an axon produce dipolar potentials, even during propagation along a straight axon. Next, by studying the electric fields generated by a dipole source in an insulating cylinder, it is shown that in finite volume conductors, the extracellular potentials can be very different from those in infinite volume conductors. Finally, the effects of impulses propagating along axons with inhomogeneous cable properties are analyzed. CONCLUSION: Because of the well-defined factors affecting extracellular potentials, the vague terms far-field and near-field potentials should be abandoned in favor of more accurate descriptions of the potentials

    Moving anticoagulation initiation and monitoring services into the community:Evaluation of the Brighton and hove community pharmacy service

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    Abstract Background As part of the NHS desire to move services closer to where people live, and provide greater accessibility and convenience to patients, Brighton and Hove Clinical Commissioning Group (CCG) underwent a review of their anticoagulation services during 2008. The outcome was to shift the initiation and monitoring service in secondary care for non-complex patients, including domiciliary patients, into the community. This was achieved via a procurement process in 2008 resulting in the Community Pharmacy Anticoagulation Management Service (CPAMs) managed by Boots UK (a large chain of community pharmacies across the United Kingdom). Methods This evaluation aims to review the outcomes (International Normalised Ratio [INR] readings) and experiences of those patients attending the anticoagulation monitoring service provided by community pharmacists in Brighton and Hove. All patients on warfarin are given a target INR range they need to achieve; dosing of and frequency of appointment are dependent on the INR result. Outcome measures for patients on the CPAM service included percentage INR readings that were within target range and the percentage time the patient was within therapeutic range. Data collected from 2009 to 2016 were analysed and results compared to the service targets. Patient experience of the service was evaluated via a locally developed questionnaire that was issued to patients annually in the pharmacy. Results The evaluation shows that community pharmacy managed anticoagulation services can achieve outcomes at a level consistently exceeding national and local targets for both percentage INR readings in therapeutic target range (65.4%) compared to the recommended minimum therapeutic target range of 60.0% and percentage time in therapeutic range (72.5%, CI 71.9–73.1%) compared to the national target of 70.0%. Patients also indicated they were satisfied with the service, with over 98.6% patients rating the service as good, very good or excellent. Conclusion The Brighton and Hove CPAM service achieved above average national target management of INR and positive patient feedback, demonstrating that community pharmacy is ideally placed to provide this service safely and deliver enhanced clinical outcomes and positive patient experience

    Spatial analysis of soil moisture and turfgrass health to determine zones for spatially variable irrigation management

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    Irrigated turfgrass is a major crop in urban areas of the drought-stricken Western United States. A considerable proportion of irrigation water is wasted through the use of conventional sprinkler systems. While smart sprinkler systems have made progress in reducing temporal mis-applications, more research is needed to determine the most appropriate variables for accurately and cost-effectively determining spatial zones for irrigation application. This research uses data from ground and drone surveys of two large sports fields. Surveys were conducted pre-, within and towards the end of the irrigation season to determine spatial irrigation zones. Principal components analysis and k-means classification were used to develop zones using several variables individually and combined. The errors associated with uniform irrigation and different configurations of spatial zones are assessed to determine comparative improvements in irrigation efficiency afforded by spatial irrigation zones. A determination is also made as to whether the spatial zones can be temporally static or need to be re-determined periodically. Results suggest that zones based on spatial soil moisture surveys and simple observations of whether the grass felt wet or dry are better than those based on NDVI, other variables and several variables in combination. In addition, due to the temporal variations observed in spatial patterns, ideally zones should be re-evaluated periodically. However, a less labor-intensive solution is to determine temporally static zones based on patterns in soil moisture averaged from several surveys. Of particular importance are the spatial patterns observed prior to the start of the irrigation season as they reflect more temporally stable variation that relates to soil texture and topography rather than irrigation management

    Systemic complement profiling in multiple sclerosis as a biomarker of disease state

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    Background: There is increasing evidence of significant and dynamic systemic activation and upregulation of complement in multiple sclerosis (MS), which may contribute to disease pathogenesis. Objective: We aimed to investigate the pathological role of complement in MS and the potential role for complement profiling as a biomarker of MS disease state. Methods: Key components of the classical, alternative and terminal pathways of complement were measured in plasma and cerebrospinal fluid (CSF) of patients with MS in different clinical phases of disease and in matched controls. Results: Increased plasma levels of C3 (p<0.003), C4 (p<0.001), C4a (p<0.001), C1 inhibitor (p<0.001), and factor H (p<0.001), and reduced levels of C9 (p<0.001) were observed in MS patients compared with controls. Combined profiling of these analytes produced a statistical model with a predictive value of 97% for MS and 73% for clinical relapse when combined with selected demographic data. CSF-plasma correlations suggested that source of synthesis of these components was both systemic and central. Conclusion: These data provide further evidence of alterations in both local and systemic expression and activation of complement in MS and suggest that complement profiling may be informative as a biomarker of MS disease, although further work is needed to determine its use in distinguishing MS from its differential

    UNBOUND

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    Unbound showcases the graduating class from the fashion design school at Fanshawe College. Unbound describes the creative spirit and achievements of our twenty-seven emerging Canadian fashion designers. Unbound 2014 is a professional collaboration between Fanshawe College, Community and Professionals in the Fashion Industry. As you turn the pages, admire their accomplishments - the results of three years of passion, hard work, and dedication.https://first.fanshawec.ca/famd_design_fashiondesign_unbound/1003/thumbnail.jp

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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