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Professional voice users often present to otolaryngologists and laryngologists with specific voice complaints. The contributions of pathologic lesions to the patients' vocal complaints are not always clear on examination, and often, premorbid examinations of the larynx are not available for review. This study examines the incidence of laryngeal pathology among singing teachers. At a national convention of singing teachers, volunteers were recruited for a "free strobovideolaryngoscopic examination." All volunteers completed a detailed questionnaire of their vocal and medical history and underwent strobovideolaryngoscopic examination. Strobovideolaryngoscopic examinations were completed in 20 volunteers, 7 of whom had voice complaints and 13 of whom perceived their voices to be normal. Vocal fold masses were common among the asymptomatic singing teachers. Evidence of reflux laryngitis was a common finding among both symptomatic and asymptomatic singing teachers. Asymmetries in vocal fold hypomobility were more common among those with voice complaints than was the presence of vocal fold masses in the population studied. 相似文献
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Jonas T. Johnson MD Editor John K. Niparko MD Editor-in-Chief Paul A. Levine MD Editor David W. Kennedy MD Editor Susan F. Rudy MSN CRNP CORLN Editor-in-Chief Pete Weber MD Editor-in-Chief Randal S. Weber MD Editor Michael S. Benninger MD Past Editor-in-Chief Richard M. Rosenfeld MD MPH Editor-in-Chief Robert J. Ruben MD Editor-in-Chief Richard J.H. Smith MD Editor-in-Chief Robert Thayer Sataloff MD DMA Editor-in-Chief Neil Weir MA FRCS Editor Emeritus 《Journal of voice》2006,20(4):485-486
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A graph G is k-critical if it has chromatic number k, but every proper subgraph of G is (k?1)-colorable. Let f k (n) denote the minimum number of edges in an n-vertex k-critical graph. In a very recent paper, we gave a lower bound, f k (n)≥(k, n), that is sharp for every n≡1 (mod k?1). It is also sharp for k=4 and every n≥6. In this note, we present a simple proof of the bound for k=4. It implies the case k=4 of two conjectures: Gallai in 1963 conjectured that if n≡1 (mod k?1) then \(f_k (n)\tfrac{{(k + 1)(k - 2)n - k(k - 3)}} {{2(k - 1)}}\) , and Ore in 1967 conjectured that for every k≥4 and \(n \geqslant k + 2,f_k (n + k - 1) = f(n) + \tfrac{{k - 1}} {2}(k - \tfrac{2} {{k - 1}})\) . We also show that our result implies a simple short proof of Grötzsch’s Theorem that every triangle-free planar graph is 3-colorable. 相似文献
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M. Ghoreishi A. I. B. MD. Ismail A. K. Alomari 《Mathematical Methods in the Applied Sciences》2011,34(15):1833-1842
This paper presents general framework for solving the nth‐order integro‐differential equation using homotopy analysis method (HAM) and optimal homotopy asymptotic method (OHAM). OHAM is parameter free and can provide better accuracy over the HAM at the same order of approximation. Furthermore, in OHAM the convergence region can be easily adjusted and controlled. Comparison, via two examples, between our solution using HAM and OHAM and the exact solution shows that the HAM and the OHAM are effective and accurate in solving the nth‐order integro‐differential equation. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献