1,015 research outputs found

    Numerical and asymptotic solutions of generalised Burgers’ equation

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    The generalised Burgers’ equation has been subject to a considerable amount of research on how the equation should behave according to asymptotic analysis, however there has been limited research verifying the asymptotic analysis. In order to verify the asymptotic analysis, this paper aims to run long time and detailed numerical simulations of Burgers’ equation by employing suitable rescalings of Burgers’ equation. It is hoped that this technique will make it possible to notice subtle changes in the shock structure which would otherwise be impossible to observe. The main aim of this paper is to validate the numerical methods used in order to allow further research into shock evolution where further relaxation effects will be included

    Quantum beats in the electric-field quenching of metastable hydrogen

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    The strong field-induced quantum beats observed in beam-foil studies of Ly- alpha radiation are obtained in a conventional metastable-hydrogen quenching experiment. The phase relation between the Stark shifted 2s 1/2- 2p 1/2 Lamb-shift oscillations and the much more rapid 2s 1-2p 3/2 fine-structure oscillations depends on the detailed way in which the quenching field is switched on. Apart from a phaseshift, the results agree with a non-perturbative theoretical calculation which assumes that the field is applied suddenly. Various frequency components of the time-dependent radiation intensity are identified with specific hyperfine transitions or groups of transitions. No adjustable parameters are used for the initial state amplitudes

    Methylmercury exposure and developmental neurotoxicity.

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    Comment on: Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review. [Bull World Health Organ. 2014]]]> Humans; Methylmercury Compounds; Neurotoxicity Syndromes eng https://serval.unil.ch/resource/serval:BIB_B254C52AD78C.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_B254C52AD78C2 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_B254C52AD78C2 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_B254CA78ED67 2022-05-07T01:25:17Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_B254CA78ED67 Application of a computationally efficient method to approximate gap model results with a probabilistic approach info:doi:10.5194/gmd-7-1543-2014 info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-7-1543-2014 Scherstjanoi, M. Kaplan, J. O. Lischke, H. info:eu-repo/semantics/article article 2014 Geoscientific Model Development, vol. 7, no. 4, pp. 1543-1571 urn:issn:1991-959x eng https://serval.unil.ch/resource/serval:BIB_B254CA78ED67.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_B254CA78ED677 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_B254CA78ED677 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_B254D0E85D5E 2022-05-07T01:25:17Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_B254D0E85D5E Meningite purulente aigue a Listeria seeligeri chez un adulte immunocompetent. [Acute purulent Listeria seelingeri meningitis in an immunocompetent adult] info:eu-repo/semantics/altIdentifier/pmid/3082004 Rocourt, J. Hof, H. Schrettenbrunner, A. Malinverni, R. Bille, J. info:eu-repo/semantics/article article 1986-02 Schweizerische Medizinische Wochenschrift, vol. 116, no. 8, pp. 248-51 info:eu-repo/semantics/altIdentifier/pissn/0036-7672 <![CDATA[Within the genus Listeria, the species L. monocytogenes most frequently causes disease in animals and humans. L. Seeligeri, a species recently described, has been considered experimentally nonpathogenic so far. The authors report the first case of human infection in a previously healthy adult presenting with acute purulent meningitis due to L. seeligeri. The patient recovered promptly after a course of ampicillin and gentamicin, but developed severe neurological sequelae (epilepsy, hydrocephalus) one year after the acute episode. The pathogenic properties of this isolate were investigated in two experimental animal models and the results were as follows. The clinical isolate of L. seeligeri was able to colonize the spleens of adult mice without bacterial multiplication, in contrast to the type strain of L. seeligeri (no colonization) and to a L. monocytogenes strain (colonization and multiplication). Previous infection of adult mice with the clinical L. seeligeri isolate protected moderately against spleen colonization and bacterial multiplication after challenge with L. monocytogenes. No lethal effect was observed after inoculation of suckling mice with the clinical L. seeligeri isolate, in contrast to L. monocytogenes strains. Thus, L. seeligeri, previously described as experimentally nonpathogenic for mice, may in fact be a heterogeneous species regarding its pathogenicity, and include strains that may cause life-threatening diseases in humans

    The OhioLINK Digital Media Center Application Profile: A New Tool for Ohio Digital Collections

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    Contains fulltext : 219863.pdf (Publisher’s version ) (Open Access)OBJECTIVES: Our goal was to report the long-term serial follow-up after transatrial-transpulmonary repair of tetralogy of Fallot (TOF) and to describe the influence of the timing of the repair on outcome. METHODS: We included all patients with TOF who had undergone transatrial-transpulmonary repair between 1970 and 2012. Records were reviewed for patient demographics, operative details and events during the follow-up period (death, pulmonary valve replacement, cardiac reinterventions and hospitalization/intervention for arrhythmias). In patients with elective early primary repair of TOF after 1990, a subanalysis of the optimal timing of TOF repair was performed. RESULTS: A total of 453 patients were included (63% male patients; 65% had transannular patch); 261 patients underwent primary elective repair after 1990. The median age at TOF repair was 0.7 years (25th-75th percentile 0.3-1.3) and decreased from 1.7 to 0.4 years from before 1990 to after 2000, respectively (P < 0.001). The median follow-up duration after TOF repair was 16.8 years (9.6-24.7). Events developed in 182 (40%) patients. In multivariable analysis, early repair of TOF (<6 months) [hazard ratio (HR) 3.06; P < 0.001] and complications after TOF repair (HR 2.18; P = 0.006) were found to be predictive for an event. In a subanalysis of the primary repair of TOF after 1990, the patients (n = 125) with elective early repair (<6 months) experienced significantly worse event-free survival compared to patients who had elective repair later (n = 136). In multivariable analysis, early repair (HR 3.00; P = 0.001) and postoperative complications (HR 2.12; P = 0.010) were associated with events in electively repaired patients with TOF. CONCLUSIONS: Transatrial-transpulmonary repair of TOF before the age of 6 months may be associated with more events during the long-term follow-up period

    Pertussis in The Netherlands: an outbreak despite high levels of immunization with whole-cell vaccine.

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    In 1996, a sudden increase in pertussis incidence was reported in the Netherlands (2.1 per 100,000 in 1995, 18 per 100,000 in 1996). Although not all potential surveillance artifacts could be excluded, it is highly probable that the data reflect a true outbreak. However, the cause of this increase has not yet been determined. Further research is directed to the severity of disease and a possible mismatch between the vaccine and the circulating Bordetella strains

    Triggering of cardiovascular hospital admissions by fine particle concentrations in New York state: Before, during, and after implementation of multiple environmental policies and a recession

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    Background Previous studies reported triggering of acute cardiovascular events by short-term increasedPM2.5 concentrations. From 2007 to 2013, national and New York state air quality policies and economic influences resulted in reduced concentrations of PM2.5 and other pollutants across the state. We estimated the rate of cardiovascular hospital admissions associated with increased PM2.5 concentrations in the previous 1–7 days, and evaluated whether they differed before (2005–2007), during (2008–2013), and after these concentration changes (2014–2016). Methods Using the Statewide Planning and Research Cooperative System (SPARCS) database, we retained all hospital admissions with a primary diagnosis of nine cardiovascular disease (CVD) subtypes, for residents living within 15 miles of PM2.5 monitoring sites in Buffalo, Rochester, Albany, Queens, Bronx, and Manhattan from 2005 to 2016 (N = 1,922,918). We used a case-crossover design and conditional logistic regression to estimate the admission rate for total CVD, and nine specific subtypes, associated with increased PM2.5 concentrations. Results Interquartile range (IQR) increases in PM2.5 on the same and previous 6 days were associated with 0.6%–1.2% increases in CVD admission rate (2005–2016). There were similar patterns for cardiac arrhythmia, ischemic stroke, congestive heart failure, ischemic heart disease (IHD), and myocardial infarction (MI). Ambient PM2.5 concentrations and annual total CVD admission rates decreased across the period. However, the excess rate of IHD admissions associated with each IQR increase in PM2.5 in previous 2 days was larger in the after period (2.8%; 95%CI = 1.5%–4.0%) than in the during (0.6%; 95%CI = 0.0%–1.2%) or before periods (0.8%; 95%CI = 0.2%–1.3%), with similar patterns for total CVD and MI, but not other subtypes. Conclusions While pollutant concentrations and CVD admission rates decreased after emission changes, the same PM2.5 mass was associated with a higher rate of ischemic heart disease events. Future work should confirm these findings in another population, and investigate whether specific PM components and/or sources trigger IHD events

    Improvement of Cardiac Function After Roux-en-Y Gastric Bypass in Morbidly Obese Patients Without Cardiac History Measured by Cardiac MRI

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    Purpose: Metabolic syndrome in patients with morbid obesity causes a higher cardiovascular morbidity, eventually leading to left ventricular hypertrophy and decreased left ventricular ejection fraction (LVEF). Roux-en-Y gastric bypass (RYGB) is considered the gold standard modality for treatment of morbid obesity and might even lead to improved cardiac function. Our objective is to investigate whether cardiac function in patients with morbid obesity improves after RYGB. Materials and Methods: In this single center pilot study, 15 patients with an uneventful cardiac history who underwent RYGB were included from May 2015 to March 2016. Cardiac function was measured by cardiac magnetic resonance imaging (CMRI), performed preoperatively and 3, 6, and 12 months postoperative. LVEF and myocardial mass and cardiac output were measured. Results: A total of 13 patients without decreased LVEF preoperative completed follow-up (mean age 37, 48.0 ± 8.8). There was a significant decrease of cardiac output 12 months postoperative (8.3 ± 1.8 preoperative vs. 6.8 ± 1.8 after 12 months, P = 0.001). Average myocardial mass declined by 15.2% (P < 0.001). After correction for body surface area (BSA), this appeared to be non-significant (P = 0.36). There was a significant improvement of LVEF/BSA at 6 and 12 months postoperative (26.2 ± 4.1 preoperative vs. 28.4 ± 3.4 and 29.2 ± 3.6 respectively, both P = 0.002). Additionally, there was a significant improvement of stroke volume/BSA 12 months after surgery (45.8 ± 8.0 vs. 51.9 ± 10.7, P = 0.033). Conclusion: RYGB in patients with morbid obesity with uneventful history of cardiac disease leads to improvement of cardiac function

    The Association between Respiratory Infection and Air Pollution in the Setting of Air Quality Policy and Economic Change

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    Rationale: Fine particulate air pollution (≤2.5µm; PM2.5) has been associated with an increased risk of respiratory disease, but assessments of specific respiratory infections in adults are lacking. Objective: To estimate the rate of respiratory infection healthcare encounters in adults associated with acute increases in PM2.5 concentrations. Methods: Using case-crossover methods, we studied 498,118 adult New York State residents with a primary diagnosis of influenza, bacterial pneumonia, or culture negative pneumonia upon hospitalization or emergency department (ED) visit (2005-2016). We estimated the rate of healthcare encounters associated with increases in PM2.5 in the previous 1-7 days and explored differences Before (2005 to 2007), During (2008-2013), and After (2014-2016) implementation of air quality policies and economic changes. Results: Interquartile range increases in PM2.5 over the previous 7 days were associated with increased excess rates of culture negative pneumonia hospitalizations (2.5%; 95% CI 1.7%, 3.2%) and ED visits (2.5%; 95% CI 1.4%, 3.6%), and increased excess rates of influenza ED visits (3.9%; 95% CI 2.1%, 5.6%). Bacterial pneumonia hospitalizations but not ED visits were associated with increases in PM2.5 and though imprecise, were of a similar magnitude to culture negative pneumonia (Lag day 6 ER 2.3%; 95% CI: 0.3, 4.3). Increased relative rates of influenza ED visits and culture negative pneumonia hospitalizations were generally larger in the After period (p&lt; 0.025 for both outcomes), compared to the During period, despite reductions in overall PM2.5 concentrations. Conclusion: Increased rates of culture negative pneumonia and influenza were associated with increased PM2.5 concentrations during the previous week, which persisted despite reductions in PM2.5 from air quality policies and economic changes. Though unexplained, this temporal variation may reflect altered toxicity of different PM2.5 mixtures or increased pathogen virulence
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