194 research outputs found

    Oxyphenbutazone in pulmonary tuberculosis

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    Die opvoeding van die gennesheer

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    Analysis, Implementation and Considerations for Liquid Crystals as a Reconfigurable Antennas Solution (LiCRAS) for Space

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    The space industry has predominantly relied on high gain reflector dish antenna apertures for performing communications, but is constantly investing in phase array antenna concepts to provide increased signal flexibility at reduced system costs in terms of finances and system resources. The problem with traditional phased arrays remains the significantly greater program cost and complexity added to the satellite by integrating arrays of antenna elements with dedicated amplifier and phase shifters to perform adaptive beam forming. Liquid Crystal Reflectarrays (LiCRas) offer some of the electrical beam forming capability of a phased array system with the component and design complexity in lines with a traditional reflector antenna aperture but without the risks associated with mechanical steering systems. The final solution is believed to be a hybrid approach that performs in between the boundaries set by the two current disparate approaches. Practical reflectarrays have been developed since the 90s as a means to control reflection of incident radiation off a flat structure that is electrically curved based on radiating elements and their reflection characteristics with tailored element phase delay. In the last decade several methods have been proposed to enable tunable reflectarrays where the electrical shape of the reflector can be steered by controlling the resonating properties of the elements on the reflector using a DC bias. These approaches range from complex fast switching MEMS and ferroelectric devices, to more robust but slower chemical changes. The aim of this work is to investigate the feasibility of a molecular transition approach in the form of liquid crystals which change permittivity based on the electrical field they are subjected to. In this work, particular attention will be paid to the impact of space environment on liquid crystal reflectarray materials and reflector architectures. Of particular interest are the effects on performance induced by the temperature extremes of space and the electromagnetic particle environment. These two items tend to drive much of the research and development for various space technologies and based on these physical influences, assertions can be made toward the space worthiness of such a material approach and can layout future R&D needs to make certain LC RF devices feasible for space use. Moreover, in this work the performance metrics of such a technology will be addressed along with methods of construction from a space perspective where specific design considerations must be made based on the extreme environment that a typical space asset must endure.\u2

    Accelerating NOvA's Feldman-Cousins procedure using high performance computing platforms

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    2019 Spring.Includes bibliographical references.In order to assess the compatibility between models containing physically constrained parameters and small-signal data, uncertainties often must be calculated by Monte Carlo simulation to account for non-normally distributed errors. This is the case for neutrino oscillation experiments, where neutrino-matter weak interactions are rare and beam intensity at the far site is low. The NuMI Off-axis νe Appearance (NOvA) collaboration attempts to measure the parameters governing neutrino oscillations within the PMNS oscillation model by comparing model predictions to a small data set of neutrino interactions. To account for non-normality, NOvA uses the computationally intensive Feldman-Cousins (FC) procedure, which involves fitting thousands of independent pseudoexperiments to generate empirical distribution functions that are used to calculate the significance of observations. I, along with collaborators on NOvA and Scientific Discovery through Advanced Computing: High Energy Physics Data Analytics (SciDAC-4) collaborations, have implemented the FC procedure utilizing the High Performance Computing (HPC) facilities at the National Energy Research Scientific Computing Center (NERSC). With this implementation, we have successfully processed NOvA's complete FC corrections for our recent neutrino + antineutrino appearance analysis in 36 hours: a speedup factor of 50 as compared to the methods used in previous analyses

    Understanding what matters to patients – identifying key patients' perceptions of quality

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    OBJECTIVES: To demonstrate a statistical method to enable the identification of key drivers of quality from a patient perspective that can be used by service providers to help drive improvement. DESIGN: Cross-tabulation, Chi-square analysis and Cramers V calculation using SPSS software of NHS Inpatient Surveys 2006 and 2007. SETTING: The NHS Inpatient Survey is a standardized survey designed by the Picker Institute conducted on a sample of patients across all acute care hospital trusts in England. PARTICIPANTS: The surveys (available from the UK Data Archive) provide anonymized patient data for over 77,000 patients in 2006 and 72,000 patients in 2007. MAIN OUTCOME MEASURES: Cramers V score testing associations between patient ratings on multiple components of care and ratings on the overall quality of care. RESULTS: Of the 58 questions analysed, some questions correlate more strongly with overall satisfaction of care than others and there is strong agreement of results over the two years. Of the top 20 rated components, communication (both between professionals and between professionals and patients) and trust engendered by that communication is a recurring theme. CONCLUSIONS: Hospital trusts are required to develop quality indicators and collate detailed feedback from patients in addition to the annual inpatient survey to measure these. To make best use of resources, additional data collection should focus on those aspects of care of most importance to patients locally. This analysis demonstrates a statistical technique that can help to identify such priority areas by showing those aspects of care most strongly associated with the overall rating of care. The analysis uses national level data to demonstrate how this can be achieved. This shows the importance to patients of being treated with dignity and respect, and good communication between staff and between staff and patients

    Application of RNS in refractory epilepsy: Targeting insula.

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    Although responsive neurostimulation (RNS) is approved for treatment of resistant focal epilepsy in adults, little is known about response to treatment of specific cortical targets. We describe the experience of RNS targeting the insular lobe. We identified patients who had RNS implantation with at least one electrode within the insula between April 2014 and October 2015. We performed a retrospective review of preoperative clinical features, imaging, electrocardiogram (EEG), intraoperative electrocorticography (ECoG), and postoperative seizure outcome. Eight patients with at least 6 months of postimplant follow-up were identified. Ictal localization was inconclusive with MRI or scalp EEG findings. Intracranial EEG monitoring or intraoperative ECoG demonstrated clear ictal onsets and/or frequent interictal discharges in the insula. Four patients demonstrated overall 50-75% reduction in seizure frequency. Two patients did not show appreciable seizure improvement. One patient has experienced a 75% reduction of seizure frequency, and another is nearly seizure free postoperatively. There were no reported direct complications of insular RNS electrode placement or stimulation, though two patients had postoperative complications thought to be related to craniotomy (hydrocephalus and late infection). Our study suggests that insular RNS electrode placement in selected patients is relatively safe and that RNS treatment may benefit selected patients with insular epilepsy

    Making change last: applying the NHSIII sustainability model to healthcare improvement

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    The implementation of evidence-based treatments to deliver high-quality care is essential to meet the healthcare demands of aging populations. However, the sustainable application of recommended practice is difficult to achieve and variable outcomes well recognised. The NHS Institute for Innovation and Improvement Sustainability Model (SM) was designed to help healthcare teams recognise determinants of sustainability and take action to embed new practice in routine care. This article describes a formative evaluation of the application of the SM by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care for Northwest London (CLAHRC NWL). Data from project teams’ responses to the SM and formal reviews was used to assess acceptability of the SM and the extent to which it prompted teams to take action. Projects were classified as ‘engaged,’ ‘partially engaged’ and ‘non-engaged.’ Quarterly survey feedback data was used to explore reasons for variation in engagement. Score patterns were compared against formal review data and a ‘diversity of opinion’ measure was derived to assess response variance over time. Of the 19 teams, six were categorized as ‘engaged,’ six ‘partially engaged,’ and seven as ‘non-engaged.’ Twelve teams found the model acceptable to some extent. Diversity of opinion reduced over time. A minority of teams used the SM consistently to take action to promote sustainability but for the majority SM use was sporadic. Feedback from some team members indicates difficulty in understanding and applying the model and negative views regarding its usefulness. The SM is an important attempt to enable teams to systematically consider determinants of sustainability, provide timely data to assess progress, and prompt action to create conditions for sustained practice. Tools such as these need to be tested in healthcare settings to assess strengths and weaknesses and findings disseminated to aid development. This study indicates the SM provides a potentially useful approach to measuring teams’ views on the likelihood of sustainability and prompting action. Securing engagement of teams with the SM was challenging and redesign of elements may need to be considered. Capacity building and facilitation appears necessary for teams to effectively deploy the SM

    Reproducibility via coordinated standardization:A multi-center study in a Shank2 genetic rat model for Autism Spectrum Disorders

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    Inconsistent findings between laboratories are hampering scientific progress and are of increasing public concern. Differences in laboratory environment is a known factor contributing to poor reproducibility of findings between research sites, and well-controlled multisite efforts are an important next step to identify the relevant factors needed to reduce variation in study outcome between laboratories. Through harmonization of apparatus, test protocol, and aligned and non-aligned environmental variables, the present study shows that behavioral pharmacological responses in Shank2 knockout (KO) rats, a model of synaptic dysfunction relevant to autism spectrum disorders, were highly replicable across three research centers. All three sites reliably observed a hyperactive and repetitive behavioral phenotype in KO rats compared to their wild-type littermates as well as a dose-dependent phenotype attenuation following acute injections of a selective mGluR1 antagonist. These results show that reproducibility in preclinical studies can be obtained and emphasizes the need for high quality and rigorous methodologies in scientific research. Considering the observed external validity, the present study also suggests mGluR1 as potential target for the treatment of autism spectrum disorders
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