371 research outputs found

    Non-planar shock waves in a magnetic field

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    AbstractThe method of multiple time scale is used to obtain the asymptotic solution to the spherically and cylindrically symmetric flow into a perfectly conducting gas permeated by a transverse magnetic field. The transport equations for the amplitudes of resonantly interacting high frequency waves are also found. The evolutionary behavior of non-resonant wave modes culminating into shock waves is studied

    Approximate Analytical Solution using Power Series Method for the Propagation of Blast Waves in a Rotational Axisymmetric non-ideal Gas

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    In this paper, the propagation of the blast (shock) waves in non-ideal gas atmosphere in rotational medium is studied using a power series method in cylindrical geometry. The flow variables are assumed to be varying according to the power law in the undisturbed medium with distance from the symmetry axis. To obtain the similarity solution, the initial density is considered as constant in the undisturbed medium. Approximate analytical solutions are obtained using Sakurai's method by extending the power series of the flow variables in power of (a0U)2{\left( {\frac{{{a_0}}}{U}} \right)^2}, where UU and a0a_0 are the speeds of the shock and sound, respectively, in undisturbed fluid. The strong shock wave is considered for the ratio (a0U)2{\left( {\frac{{{a_0}}}{U}} \right)^2} which is considered to be a small quantity. With the aid of that method, the closed-form solutions for the zeroth-order approximation is given as well as first-order approximate solutions are discussed. Also, with the help of graphs behind the blast wave for the zeroth-order approximation, the distributions of variables such as density, radial velocity, pressure and azimuthal fluid velocity are analyzed. The results for the rotationally axisymmetric non-ideal gas environment are compared to those for the ideal gas atmosphere

    Asymptotical solutions for a vibrationally relaxing gas

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    Using the weakly non‐linear geometrical acoustics theory, we obtain the small amplitude high frequency asymptotic solution to the basic equations governing one dimensional unsteady planar, spherically and cylindrically symmetric flow in a vibrationally relaxing gas with Van der Waals equation of state. The transport equations for the amplitudes of resonantly interacting waves are derived. The evolutionary behavior of non‐resonant wave modes culminating into shock waves is also studied. First published online: 14 Oct 201

    Antibiotics sensitivity status and antibiogram patterns of aerobic bacterial isolates from surgical site infections

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    Background: Surgical Site Infections (SSIs) are the third most common nosocomial infections. Emergence and spread of drug resistant strains have been found to pose a serious challenge in the management of such infections. There is limited information on the epidemiology of such pathogens. The antibiotic sensitivity patterns of aerobic bacterial isolates from post-operative SSIs show wide variations that lead to difficulties in empirical selection of the right kind of drug for treatment. Properly planned studies about antibiotic sensitivities patterns of such isolates can help in judicious management of SSIs and cause reduction in morbidity and mortality.Methods: A total of 50 patients diagnosed by the surgeon and fulfilling the case definition of SSI, were studied for bacteriological analysis. All the clinical specimens were cultured and identified applying standard culture techniques. The aerobic bacterial isolates were subjected to antimicrobial susceptibility testing by Kirby Bauer Disc Diffusion method to arrive at the drug sensitivity patterns. Data were entered in MS Excel spread sheet and analysed using SSPP software version 21.00Results: A total of 32 patterns of sensitivity were observed. For Esch. coli, a total of nine patterns were observed. All strains of Esch. coli were found sensitive to tigecycline (100%) and colistin (100%). For Klebsiella spp. a total of 9 patterns were obtained with TIG-COL being the predominant pattern in 6 cases. For Acinetobacter spp. only colistin was found most effective drug. In case of Pseudomonas aeruginosa, except colistin (100% sensitivity), there were wide variations in sensitivity with imipenem (71%) as next most effective drug. In Proteus spp. - most of the in-use drugs were effective except cephalosporins. Among gram positive organisms, only three strains of Staphylococcus aureus were isolated, and these were MRSA (100%). Two strains of enterococcus were isolated, and these showed sensitivity to linezolid only.Conclusions: Wide variations in sensitivity status observed in the study are suggestive that antibiotic usage should be tailored to individual needs and proper selection of antibiotics for management of SSIs must be guided by laboratory antibiogram

    Influenza vaccination coverage among an urban pediatric asthma population: Implications for population health

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    Introduction Asthma is the most common chronic disease in children. Children with asthma are at high risk for complications from influenza; however annual influenza vaccination rates for this population are suboptimal. The overall aim of this study was to describe the characteristics of a high-risk population of children with asthma presenting to an urban pediatric emergency department according to influenza vaccination status. Methods The study was a retrospective chart review of 4355 patients aged 2 to 18 years evaluated in a Michigan pediatric emergency department (PED) between November 1, 2017 and April 30, 2018 with an ICD-10-CM code for asthma (J45.x). Eligible patient PED records were matched with influenza vaccination records for the 2017–2018 influenza season from the Michigan Care Improvement Registry. Geospatial analysis was employed to examine the distribution of influenza vaccination status. Results 1049 patients (30.9%) with asthma seen in the PED had received an influenza vaccine. Influenza vaccination coverage varied by Census Tract, ranging from 10% to \u3e 99%. Most vaccines were administered in a primary care setting (84.3%) and were covered by public insurance (76.8%). The influenza vaccination rate was lowest for children aged 5–11 years (30.0%) and vaccination status was associated with race (p\u3c0.001) and insurance type (p\u3c0.001). Conclusions Identification of neighborhood Census Tract and demographic groups with suboptimal influenza vaccination could guide development of targeted public health interventions to improve vaccination rates in high-risk patients. Given the morbidity and mortality associated with pediatric asthma, a data-driven approach may improve outcomes and reduce healthcare-associated costs for this pediatric population

    The Effect of the Dynamics of Knowledge Base Complexity on Schumpeterian patterns of Innovation: the upstream petroleum industry

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    This paper addresses important changes in innovation patterns in the upstream petroleum industry over the period from the 1970s to 2005. It argues that the shifts in patterns of innovation over that period can be explained by the dynamics of knowledge base complexity (KBC). We develop a quantitative method to explore KBC and show that increasing KBC has shifted innovation patterns, from a broadly Schumpeter Mark I to a 'modified' form of Schumpeter Mark II, led less by the established oil majors, but by a new class of integrated service providers

    SMARThealth Pregnancy: Feasibility and Acceptability of a Complex Intervention for High-Risk Pregnant Women in Rural India: Protocol for a Pilot Cluster Randomised Controlled Trial.

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    Introduction: India is in the process of a major epidemiological transition towards non-communicable diseases. Cardiovascular disease (CVD) is the leading cause of death in women in India. Predisposing independent risk factors include pregnancy-related conditions, e.g., hypertensive disorders of pregnancy (HDP) and gestational diabetes (GDM) - also associated with significant perinatal mortality and morbidity. Early identification, referral and management of pregnant women at increased risk of future CVD may offer opportunities for prevention. In rural India, Community Health Workers (CHWs) provide most antenatal and postnatal care. Innovative solutions are required to address integrated care for rural women during transitions between antenatal, postnatal and general health services. The George Institute's SMARThealth Programme has shown that CHWs in rural India screening non-pregnant adults for cardiovascular risk, using a decision support system, is feasible. Building on this, we developed a targeted training programme for CHWs and a complex system-level intervention that uses mobile clinical decision support for CHWs and primary care doctors to screen high-risk pregnant women. In addition to addressing HDP and GDM, the intervention also screens for anaemia in pregnancy. Methods/Design: A pilot study will be undertaken in two diverse rural districts of India: Jhajjar (Haryana) and Guntur (Andhra Pradesh). Two Primary Health Centre clusters will be randomised to intervention or control groups at each study site. The primary objective of this pilot study is to explore the feasibility and acceptability of the SMARThealth Pregnancy intervention. Secondary objectives are to estimate: (a) prevalence rates of moderate to severe anaemia, HDPs and GDM at the study sites; (b) referral and follow-up rates, and (c) mean haemoglobin and blood pressure values at the routine 6 week postnatal visit. A process evaluation will be conducted to explore the acceptability of the SMARThealth Pregnancy intervention for pregnant women and healthcare workers using qualitative methods. Discussion: It is anticipated that the findings of this pilot study will help determine the feasibility and acceptability of the SMARThealth Pregnancy intervention, and highlight how the intervention might be further developed for evaluation in a larger, cluster randomised controlled trial. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03968952
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