This paper examines an updated version of a lumped mucosal wave model of the vocal fold oscillation during phonation. Threshold values of the subglottal pressure and the mean (DC) glottal airflow for the oscillation onset are determined. Depending on the nonlinear characteristics of the model, an oscillation hysteresis phenomenon may occur, with different values for the oscillation onset and offset threshold. The threshold values depend on the oscillation frequency, but the occurrence of the hysteresis is independent of it. The results are tested against pressure data collected from a mechanical replica of the vocal folds, and oral airflow data collected from speakers producing intervocalic /h/. In the human speech data, observed differences between voice onset and offset may be attributed to variations in voice pitch, with a very small or inexistent hysteresis phenomenon.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078032 | PMC |
http://dx.doi.org/10.1121/1.3531805 | DOI Listing |
Clin Dermatol
November 2021
Dermatology Unit, Ospedale Policlinico San Martino, Largo R. Benzi, Genoa, Italy; DI.S. Sal., Section of Dermatology, University of Genoa, Via Pastore 1, Genoa, Italy.
PLoS One
October 2020
Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
Background: Double-lumen tube is commonly used in thoracic surgeries that need one-lung ventilation, but its big size and stiff structure make it harder to perform intubation than a conventional tracheal intubation tube.
Objectives: To investigate the effectiveness and safety of videoscopes for double-lumen tube insertion. The primary outcome was the success rate of first attempt intubation.
Eur J Pharm Sci
April 2019
Centre for Applied Pharmacokinetic Research, School of Health Sciences, The University of Manchester, Manchester, United Kingdom; Certara UK Ltd., Sheffield, United Kingdom.
Physiologically-based pharmacokinetic (PBPK) models provide a framework for in vitro-in vivo extrapolation of metabolic drug clearance. Many of the concepts in PBPK can have consequential impact on more mechanistic systems pharmacology models. In the gut wall, turnover of enzymes and enterocytes are typically lumped into one rate constant that describes the time dependent enzyme activity.
View Article and Find Full Text PDFDrug Metab Dispos
December 2014
Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom (A.S.D., U.A., D.M.A., A.R.-H.); and Simcyp (a Certara company), Sheffield, United Kingdom (A.R.-H.).
Due to the rapid turnover of the small intestinal epithelia, the rate at which enterocyte renewal occurs plays an important role in determining the level of drug-metabolizing enzymes in the gut wall. Current physiologically based pharmacokinetic (PBPK) models consider enzyme and enterocyte recovery as a lumped first-order rate. An assessment of enterocyte turnover would enable enzyme and enterocyte renewal to be modeled more mechanistically.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!