883 research outputs found

    Parareal Convergence for Oscillatory PDEs with Finite Time-scale Separation

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    This is the final version. Available on open access from the Society for Industrial and Applied Mathematics via the DOI in this recordA variant of the Parareal method for highly oscillatory systems of PDEs was proposed by Haut and Wingate (2014). In that work they proved superlinear conver- gence of the method in the limit of infinite time scale separation. Their coarse solver features a coordinate transformation and a fast-wave averag- ing method inspired by analysis of multiple scales PDEs and is integrated using an HMM-type method. However, for many physical applications the timescale separation is finite, not infinite. In this paper we prove con- vergence for finite timescale separaration by extending the error bound on the coarse propagator to this case. We show that convergence requires the solution of an optimization problem that involves the averaging win- dow interval, the time step, and the parameters in the problem. We also propose a method for choosing the averaging window relative to the time step based as a function of the finite frequencies inherent in the problem.University of Exete

    Patients with epilepsy and psychogenic non-epileptic seizures: An inpatient video-EEG monitoring study

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    AbstractSeizure and EEG characteristics of patients with epilepsy and concomitant psychogenic non-epileptic seizures (PNES) were compared to age and sex matched controls with epilepsy alone in a retrospective case control study. 39 patients with clearly documented epileptic and non-epileptic events were compared to 78 age and sex matched controls, sequentially admitted for video-EEG monitoring with documentation of epilepsy alone. Frontal seizures were higher in prevalence in patients with PNES who had concomitant epilepsy (P<0.001), while temporal seizures were higher in prevalence in patients with epilepsy alone (P<0.04). On regression analysis, the odds of having a frontal seizure was found to be significantly lower in the epilepsy alone group compared to the epilepsy+PNES group (odds ratio 0.13, 95% CI, 0.033–0.51). This significant association between frontal lobe epilepsy and PNES may be related to misattribution of frontal seizures for PNES events, or may reflect frontal lobe cortical dysfunction in this subgroup

    Blood Transfusions--Strict Liability?

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    The mesomorphic phase transition temperatures of the unsymmetrical 1,4-phenylene esters of the 4-n-alkoxybenzoic acids

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    The normal melting process occurs at a specific temperature, characteristic of every substance, when the constituent molecules of the solid have sufficient vibrational kinetic energy to overcome the net attractive forces binding the crystal lattice. The resulting phase change involves a transition from the highly ordered environment of the solid to the isotropic liquid. From X-ray diffraction studies1, the isotropic liquid has been found to possess some short range molecular ordering. The absence of any long range order prevents the liquid from exhibiting properties of the solid state, particularly those properties which are characteristically associated with crystalline anisotropy. However birefringence and some other anisotropic properties are shown by the melts of certain organic compounds. The phenomenon was first observed by Reinitzer2 in 1888 with esters of cholesterol and Lehmann3 in 1890 with ammonium oleate and p-azoxyphenetole. Both men found that the substances melted sharply at specific temperatures to give cloudy liquids which, when heated further, cleared suddenly at characteristic temperatures to yield the normal liquid. The melts were also found to be birefringent in thin films when viewed with crossed polaroids - a property previously found only in crystalline solids

    Are we responding effectively to bone mineral density loss and fracture risks in people with epilepsy?

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    © 2020 The Authors. Epilepsia Open published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy. Objective: A 2007 study performed at Montefiore Medical Center (Bronx, NY) identified high prevalence of reduced bone density in an urban population of patients with epilepsy and suggested that bone mineralization screenings should be regularly performed for these patients. We conducted a long-term follow-up study to determine whether bone mineral density (BMD) loss, osteoporosis, and fractures have been successfully treated or prevented. Methods: In the current study, patients from the 2007 study who had two dual-energy absorptiometry (DXA) scans performed at least 5 years apart were analyzed. The World Health Organization (WHO) criteria to diagnose patients with osteopenia or osteoporosis were used, and each patient\u27s probability of developing fractures was calculated with the Fracture Risk Assessment Tool (FRAX). Results: The median time between the first and second DXA scans for the 81 patients analyzed was 9.4 years (range 5-14.7). The median age at the first DXA scan was 41 years (range 22-77). Based on WHO criteria, 79.0% of patients did not have worsening of bone density, while 21.0% had new osteopenia or osteoporosis; many patients were prescribed treatment for bone loss. Older age, increased duration of anti-epileptic drug (AED) usage, and low body mass index (BMI) were risk factors for abnormal BMDs. Based on the first DXA scan, the FRAX calculator estimated that none of the patients in this study had a 10-year risk of more than 20% for developing major osteoporotic fracture (hip, spine, wrist, or humeral fracture). However, in this population, 11 patients (13.6%) sustained a major osteoporotic fracture after their first DXA scan. Significance: Despite being routinely screened and frequently treated for bone mineral density loss and fracture prevention, many patients with epilepsy suffered new major osteoporotic fractures. This observation is especially important as persons with epilepsy are at high risk for falls and traumas

    Primary Care Case Conferences to Mitigate Social Determinants of Health: A Case Study from One FQHC System

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    Objective: Given the increasing difficulty healthcare providers face in addressing patients’ complex social circumstances and underlying health needs, organizations are considering team-based approaches including case conferences. We sought to document various perspectives on the facilitators and challenges of conducting case conferences in primary care settings. Study Design: Qualitative study using semi-structured telephone interviews Methods: We conducted 22 qualitative interviews with members of case conferencing teams, including physicians, nurses, and social workers from a Federally Qualified Health Clinic, as well as local county public health nurses. Interviews were recorded, transcribed, and reviewed using thematic coding to identify key themes/subthemes. Results: Participants reported perceived benefits to patients, providers, and healthcare organizations including better care, increased inter-professional communication, and shared knowledge. Perceived challenges related to underlying organizational processes and priorities. Perceived facilitators for successful case conferences included generating and maintaining a list of patients to discuss during case conference sessions and team members being prepared to actively participate in addressing tasks and patient needs during each session. Participants offered recommendations for further improving case conferences for patients, providers, and organizations. Conclusions: Case conferences may be a feasible approach to understanding patient’s complex social needs. Participants reported that case conferences may help mitigate the effects of these social issues and that they foster better inter-professional communication and care planning in primary care. The case conference model requires administrative support and organizational resources to be successful. Future research should explore how case conferences fit into a larger population health organizational strategy so that they are resourced commensurately
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