63 research outputs found

    Nonlinear flexural waves in fluid–filled elastic channels

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    Nonlinear waves on liquid sheets between thin infinite elastic plates are studied analytically and numerically. Linear and nonlinear models are used for the elastic plates coupled to the Euler equations for the fluid. One-dimensional time dependent equations are derived based on a long-wavelength approximation. Inertia of the elastic plates is neglected, so linear perturbations are stable. Symmetric and mixed-mode travelling waves are found with the linear plate model and symmetric travelling waves are found for the nonlinear case. Numerical simulations are employed to study the evolution in time of initial disturbances and to compare the different models used. Nonlinear effects are found to decrease the travelling wave speed compared with linear models. At sufficiently large amplitude of initial disturbances, higher order temporal oscillations induced by non-linearity can lead to thickness of the liquid sheet approaching zero

    The politics of homeschools: Religious conservatives and regulation requirements

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    Over the last few decades, the number of homeschools in the United States (US) has grown, and a large proportion is attributed to increases in religiously affiliated homeschools (Kunzman, 2009). However, empirical analyses of the relationship between religion and homeschooling are lacking. This analysis begins to fill that void using a culture wars framework, and indicates that states with higher percentages of evangelical residents are less likely to regulate homeschooling. Consistent with Deckman\u27s (2004) claim, these findings demonstrate the culture wars are active in education policymaking

    Prognostic value of mid-regional pro-adrenomedullin in patients with acute myocardial infarction. Leicester Acute Myocardial Infarction Peptide (LAMP) study.

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    Background: Adrenomedullin(ADM) is elevated in heart failure(HF) and after acute myocardial infarction(AMI). Another part of its precursor, mid-regional proADM(MR-proADM) is more stable in circulation and ex-vivo. We investigated the cardiovascular prognostic value post-AMI of MR-proADM and compared it to N-terminal B-type natriuretic peptide (NTproBNP), a marker of death and HF. Methods: We measured plasma MR-proADM and NTproBNP in 983 consecutive post-AMI patients (721 men, mean age 65.0±(SD)12.2 years), 3-5 days after chest pain onset. Results: There were 101 deaths and 49 readmissions with HF during follow up (median 342, range 0-764 days). MR-proADM was raised in patients with death or HF compared to survivors (median [range]nmol/L, 1.19[0.09-5.39] vs. 0.71[0.25-6.66]; p<0.0001). Using a multivariate binary logistic model, log MR-proADM (OR 4.22) and log NTproBNP (OR 3.20) were significant independent predictors of death or HF (with creatinine, age, gender and past history of AMI). The areas under the receiver-operating curve (AUC) for MR-proADM, NTproBNP and the logistic model with both markers were 0.77, 0.79 and 0.84 respectively. Cox models for the predictors of death or HF revealed the same variables (including log MR-proADM (HR 3.63), log NTproBNP (HR 2.67)). MR-proADM provided further risk stratification in those patients who had NTproBNP level above the median (p<0.0001). Findings were similar for death and HF as individual endpoints. Conclusions: The adrenomedullin system is activated post-AMI. MR-proADM is a powerful predictor of adverse outcome especially in those with an elevated NTproBNP. MR-proADM may represent a clinically useful marker of prognosis after AMI
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