Prosodic Resonance

We may regard a syllable as consisting of an initial consonant cluster (which may be zero), a vowel cluster, and a final consonant cluster (which may be zero in most schemes of phonemic analysis)

Assimilation of Experimental Data to Create a Quantitatively Accurate Reduced-Order Thermoacoustic Model

Abstract We combine a thermoacoustic experiment with a thermoacoustic reduced order model using Bayesian inference to accurately learn the parameters of the model, rendering it predictive. The experiment is a vertical Rijke tube containing an electric heater. The heater drives a base flow via natural convection, and thermoacoustic oscillations via velocity-driven heat release fluctuations. The decay rates and frequencies of these oscillations are measured every few seconds by acoustically forcing the system via a loudspeaker placed at the bottom of the tube. More than 320,000 temperature measurements are used to compute state and parameters of the base flow model using the Ensemble Kalman Filter. A wave-based network model is then used to describe the acoustics inside the tube. We balance momentum and energy at the boundary between two adjacent elements, and model the viscous and thermal dissipation mechanisms in the boundary layer and at the heater and thermocouple locations. Finally, we tune the parameters of two different thermoacoustic models on an experimental dataset that comprises more than 40,000 experiments. This study shows that, with thorough Bayesian inference, a qualitative model can become quantitatively accurate, without overfitting, as long as it contains the most influential physical phenomena.European Unio

Second-order perturbation of global modes and implications for spanwise wavy actuation

AbstractSensitivity analysis has successfully located the most efficient regions in which to apply passive control in many globally unstable flows. As is shown here and in previous studies, the standard sensitivity analysis, which is linear (first order) with respect to the actuation amplitude, predicts that steady spanwise wavy alternating actuation/modification has no effect on the stability of planar flows, because the eigenvalue change integrates to zero in the spanwise direction. In experiments, however, spanwise wavy modification has been shown to stabilize the flow behind a cylinder quite efficiently. In this paper, we generalize sensitivity analysis by examining the eigenvalue drift (including stabilization/destabilization) up to second order in the perturbation, and show how the second-order eigenvalue changes can be computed numerically by overlapping the adjoint eigenfunction with the first-order global eigenmode correction, shown here for the first time. We confirm the prediction against a direct computation, showing that the eigenvalue drift due to a spanwise wavy base flow modification is of second order. Further analysis reveals that the second-order change in the eigenvalue arises through a resonance of the original (2-D) eigenmode with other unperturbed eigenmodes that have the same spanwise wavelength as the base flow modification. The eigenvalue drift due to each mode interaction is inversely proportional to the distance between the eigenvalues of the modes (which is similar to resonance), but also depends on mutual overlap of direct and adjoint eigenfunctions (which is similar to pseudoresonance). By this argument, and by calculating the most sensitive regions identified by our analysis, we explain why an in-phase actuation/modification is better than an out-of-phase actuation for control of wake flows by spanwise wavy suction and blowing. We also explain why wavelengths several times longer than the wake thickness are more efficient than short wavelengths.This work was supported by the European Research Council through Project ALORS 2590620.This is the accepted manuscript. The final version is available from CUP at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9326225&fileId=S002211201400415

Modification of the asthma quality of life questionnaire (standardised) for patients 12 years and older

BACKGROUND: The age limit for some adult asthma clinical trials has recently been lowered to 12 years. In this study we have made minor modifications to the standardised version of the adult Asthma Quality of Life Questionnaire (AQLQ(S)) to make it valid for patients 12 years and older (AQLQ12+). METHODS: We have used two clinical trial databases, in which the AQLQ12+ was used, to compare the measurement properties of the questionnaire in patients 12–17 years and patients 18 years and older. A total of 2433 patients (12–75 years), with current asthma and with data that could be evaluated both at randomisation and end of treatment, were included. RESULTS: The analysis showed that internal consistency, responsiveness and correlations with other clinical indices were very similar in patients 12–17 years and patients 18 years and older. CONCLUSION: The measurement properties of the AQLQ12+ are similar in adolescents and adults and therefore the instrument is valid for use in adult studies which include children 12 years and older

Leukotriene antagonists as first-line or add-on asthma controller therapy

Most randomized trials of treatment for asthma study highly selected patients under idealized conditions. METHODS: We conducted two parallel, multicenter, pragmatic trials to evaluate the real-world effectiveness of a leukotriene-receptor antagonist (LTRA) as compared with either an inhaled glucocorticoid for first-line asthma-controller therapy or a long-acting beta(2)-agonist (LABA) as add-on therapy in patients already receiving inhaled glucocorticoid therapy. Eligible primary care patients 12 to 80 years of age had impaired asthma-related quality of life (Mini Asthma Quality of Life Questionnaire [MiniAQLQ] score =6) or inadequate asthma control (Asthma Control Questionnaire [ACQ] score =1). We randomly assigned patients to 2 years of open-label therapy, under the care of their usual physician, with LTRA (148 patients) or an inhaled glucocorticoid (158 patients) in the first-line controller therapy trial and LTRA (170 patients) or LABA (182 patients) added to an inhaled glucocorticoid in the add-on therapy trial. RESULTS: Mean MiniAQLQ scores increased by 0.8 to 1.0 point over a period of 2 years in both trials. At 2 months, differences in the MiniAQLQ scores between the two treatment groups met our definition of equivalence (95% confidence interval [CI] for an adjusted mean difference, -0.3 to 0.3). At 2 years, mean MiniAQLQ scores approached equivalence, with an adjusted mean difference between treatment groups of -0.11 (95% CI, -0.35 to 0.13) in the first-line controller therapy trial and of -0.11 (95% CI, -0.32 to 0.11) in the add-on therapy trial. Exacerbation rates and ACQ scores did not differ significantly between the two groups. CONCLUSIONS: Study results at 2 months suggest that LTRA was equivalent to an inhaled glucocorticoid as first-line controller therapy and to LABA as add-on therapy for diverse primary care patients. Equivalence was not proved at 2 years. The interpretation of results of pragmatic research may be limited by the crossover between treatment groups and lack of a placebo group

Stability analysis of thermo-acoustic nonlinear eigenproblems in annular combustors. Part II. Uncertainty quantification

Monte Carlo and Active Subspace Identification methods are combined with first- and second-order adjoint sensitivities to perform (forward) uncertainty quantification analysis of the thermo-acoustic stability of two annular combustor configurations. This method is applied to evaluate the risk factor, i.e., the probability for the system to be unstable. It is shown that the adjoint approach reduces the number of nonlinear-eigenproblem calculations by up to $\sim\mathcal{O}(M)$, as many as the Monte Carlo samples.European Research Council (Project ALORS 2590620), Royal Academy of Engineering (Research Fellowships Scheme

Control of Allergic Rhinitis and Asthma Test (CARAT) can be used to assess individual patients over time

BACKGROUND: The Control of Allergic Rhinitis and Asthma Test (CARAT10) has been proposed as the first tool to implement the Allergic Rhinitis and its Impact on Asthma initiative guidelines in clinical practice. To serve this purpose, it must have adequate properties to assess the control of an individual over time. This study aimed to prospectively assess the test-retest reliability, responsiveness and longitudinal validity of CARAT10. METHODS: Adults with asthma and allergic rhinitis were enrolled at 4 outpatient clinics of Portuguese central hospitals. At each of the two visits, 4 to 6 weeks apart, patients filled out CARAT10 and additional questionnaires, followed by a medical evaluation blinded to the questionnaires' answers. RESULTS: From the 62 patients included, 51 patients completely filled out CARAT10 at both visits. The test-retest reliability, computed as an intra-class correlation coefficient, was 0.82. Regarding responsiveness, a significant change (p = 0.002) of CARAT10 score in clinically unstable patients was observed (95%CI -5.08; -1.31) and the Guyatt's responsiveness index was 1.54. As for the longitudinal validity assessment, the correlation coefficients of the changes of CARAT10 scores with those of ACQ5 and symptoms VAS ranged from 0.49 to 0.65, while with the physician assessment of control they ranged from 0.31 to 0.41. CONCLUSION: CARAT10 has good test-retest reliability, responsiveness and longitudinal validity. It can be used to assess control of allergic rhinitis and asthma, both to compare groups in clinical studies and to evaluate individual patients in clinical practice

Tailored second line therapy in asthmatic children with the arginine-16 genotype

The arginine-16 beta-2 receptor genotype confers increased susceptibility to exacerbations in asthmatic children taking regular long acting beta-2 agonists. We therefore evaluated using montelukast as an alternative to salmeterol as tailored second line asthma controller therapy in children expressing this susceptible genotype. 62 persistent asthmatic children with the homozygous arginine-16 genotype were randomized to receive salmeterol 50ug bid or montelukast 5/10mg od as add on to inhaled fluticasone for 1 year. School absences (the primary outcome) were reduced with montelukast arm compared to salmeterol: difference in score = 0.40 (95%CI 0.07-0.87) p=0.005. Albuterol use was also reduced with montelukast compared with salmeterol: difference in score = 0.47 (95%CI 0.16-0.79) p<0.0001. Greater improvements occurred in both symptom and quality of life scores with montelukast vs salmeterol, while there was no difference in FEV1. Montelukast may be suitable as tailored second line controller therapy instead of salmeterol in asthmatic children expressing the susceptible arginine-16 genotype - moving towards a personalised medicine approach to management

Development, validity and responsiveness of the Clinical COPD Questionnaire

BACKGROUND: The new Global Obstructive Lung Disease (GOLD) guidelines advice to focus treatment in Chronic Obstructive Pulmonary Disease (COPD) on improvement of functional state, prevention of disease progression and minimization of symptoms. So far no validated questionnaires are available to measure symptom and functional state in daily clinical practice. The aim of this study was to develop and validate the Clinical COPD Questionnaire (CCQ). METHODS: Qualitative research with patients and clinicians was performed to generate possible items to evaluate clinical COPD control. Thereafter, an item reduction questionnaire was sent to 77 international experts. Sixty-seven experts responded and the 10 most important items, divided into 3 domains (symptoms, functional and mental state) were included in the CCQ (scale: 0 = best, 6 = worst). RESULTS: Cross-sectional data were collected from 119 subjects (57 COPD, GOLD stage I-III; 18 GOLD stage 0 and 44 (ex)smokers). Cronbach's α was high (0.91). The CCQ scores in patients (GOLD 0-III) were significantly higher than in healthy (ex)smokers. Furthermore, significant correlations were found between the CCQ total score and domains of the SF-36 (ρ = 0.48 to ρ = 0.69) and the SGRQ (ρ = 0.67 to ρ = 0.72). In patients with COPD, the correlation between the CCQ and FEV(1)%pred was ρ =-0.49. Test-retest reliability was determined in 20 subjects in a 2-week interval (Intra Class Coefficient = 0.94). Thirty-six smokers with and without COPD showed significant improvement in the CCQ after 2 months smoking cessation, indicating the responsiveness of the CCQ. CONCLUSION: The CCQ is a self-administered questionnaire specially developed to measure clinical control in patients with COPD. Data support the validity, reliability and responsiveness of this short and easy to administer questionnaire