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Weizbauer RA, Cook DD. Cell wall mechanics: Some new twists. Biophys J 2022; 121:865-868. [PMID: 35235769 PMCID: PMC8943809 DOI: 10.1016/j.bpj.2022.02.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/05/2022] [Accepted: 02/09/2022] [Indexed: 11/02/2022] Open
Affiliation(s)
- Renate A Weizbauer
- Department of Plant Biology, Carnegie Institution of Washington, Stanford, California.
| | - Douglas D Cook
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah
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Kostin JE, Cesarz S, Lochner A, Schädler M, Macdonald CA, Eisenhauer N. Land-use drives the temporal stability and magnitude of soil microbial functions and modulates climate effects. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02325. [PMID: 33709490 DOI: 10.1002/eap.2325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 11/01/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Soil microbial community functions are essential indicators of ecosystem multifunctionality in managed land-use systems. Going forward, the development of adaptation strategies and predictive models under future climate scenarios will require a better understanding of how both land-use and climate disturbances influence soil microbial functions over time. Between March and November 2018, we assessed the effects of climate change on the magnitude and temporal stability of soil basal respiration, soil microbial biomass and soil functional diversity across a range of land-use types and intensities in a large-scale field experiment. Soils were sampled from five common land-use types including conventional and organic croplands, intensive and extensive meadows, and extensive pastures, under ambient and projected future climate conditions (reduced summer precipitation and increased temperature) at the Global Change Experimental Facility (GCEF) in Bad Lauchstädt, Germany. Land-use and climate treatment interaction effects were significant in September, a month when precipitation levels slightly rebounded following a period of drought in central Germany: compared to ambient climate, in future climate treatments, basal respiration declined in pastures and increased in intensive meadows, functional diversity declined in pastures and croplands, and respiration-to-biomass ratio increased in intensive and extensive meadows. Low rainfall between May and August likely strengthened soil microbial responses toward the future climate treatment in September. Although microbial biomass showed declining levels in extensive meadows and pastures under future climate treatments, overall, microbial function magnitudes were higher in these land-use types compared to croplands, indicating that improved management practices could sustain high microbial ecosystem functioning in future climates. In contrast to our hypothesis that more disturbed land-use systems would have destabilized microbial functions, intensive meadows and organic croplands showed stabilized soil microbial biomass compared to all other land-use types, suggesting that temporal stability, in addition to magnitude-based measurements, may be useful for revealing context-dependent effects on soil ecosystem functioning.
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Affiliation(s)
- Julia E Kostin
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Faculty of Management Science and Economics, Leipzig University, Grimmaische Straße 12, Leipzig, 04109, Germany
| | - Simone Cesarz
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Institute of Biology, Leipzig University, Deutscher Platz 5e, Leipzig, 04103, Germany
| | - Alfred Lochner
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
| | - Martin Schädler
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Department of Community Ecology, Helmholtz-Centre for Environmental Research - UFZ, Theodor-Lieser-Street 4, Halle, 06120, Germany
| | - Catriona A Macdonald
- Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Nico Eisenhauer
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Institute of Biology, Leipzig University, Deutscher Platz 5e, Leipzig, 04103, Germany
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Deng JJ, Hadwin PJ, Peterson SD. The effect of high-speed videoendoscopy configuration on reduced-order model parameter estimates by Bayesian inference. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146. [PMID: 31472542 PMCID: PMC6715443 DOI: 10.1121/1.5124256#suppl] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Bayesian inference has been previously demonstrated as a viable inverse analysis tool for estimating subject-specific reduced-order model parameters and uncertainties. However, previous studies have relied upon simulated glottal area waveforms with superimposed random noise as the measurement. In practice, high-speed videoendoscopy is used to measure glottal area, which introduces practical imaging effects not captured in simulated data, such as viewing angle, frame rate, and camera resolution. Herein, high-speed videos of the vocal folds were approximated by recording the trajectories of physical vocal fold models controlled by a symmetric body-cover model. Twenty videos were recorded, varying subglottal pressure, cricothyroid activation, and viewing angle, with frame rate and video resolution varied by digital video manipulation. Bayesian inference was used to estimate subglottal pressure and cricothyroid activation from glottal area waveforms extracted from the videos. The resulting estimates show off-axis viewing of 10° can lead to a 10% bias in the estimated subglottal pressure. A viewing model is introduced such that viewing angle can be included as an estimated parameter, which alleviates estimate bias. Frame rate and pixel resolution were found to primarily affect uncertainty of parameter estimates up to a limit where spatial and temporal resolutions were too poor to resolve the glottal area. Since many high-speed cameras have the ability to sacrifice spatial for temporal resolution, the findings herein suggest that Bayesian inference studies employing high-speed video should increase temporal resolutions at the expense of spatial resolution for reduced estimate uncertainties.
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Affiliation(s)
- Jonathan J Deng
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
| | - Paul J Hadwin
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
| | - Sean D Peterson
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
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Deng JJ, Hadwin PJ, Peterson SD. The effect of high-speed videoendoscopy configuration on reduced-order model parameter estimates by Bayesian inference. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:1492. [PMID: 31472542 PMCID: PMC6715443 DOI: 10.1121/1.5124256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 08/07/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Bayesian inference has been previously demonstrated as a viable inverse analysis tool for estimating subject-specific reduced-order model parameters and uncertainties. However, previous studies have relied upon simulated glottal area waveforms with superimposed random noise as the measurement. In practice, high-speed videoendoscopy is used to measure glottal area, which introduces practical imaging effects not captured in simulated data, such as viewing angle, frame rate, and camera resolution. Herein, high-speed videos of the vocal folds were approximated by recording the trajectories of physical vocal fold models controlled by a symmetric body-cover model. Twenty videos were recorded, varying subglottal pressure, cricothyroid activation, and viewing angle, with frame rate and video resolution varied by digital video manipulation. Bayesian inference was used to estimate subglottal pressure and cricothyroid activation from glottal area waveforms extracted from the videos. The resulting estimates show off-axis viewing of 10° can lead to a 10% bias in the estimated subglottal pressure. A viewing model is introduced such that viewing angle can be included as an estimated parameter, which alleviates estimate bias. Frame rate and pixel resolution were found to primarily affect uncertainty of parameter estimates up to a limit where spatial and temporal resolutions were too poor to resolve the glottal area. Since many high-speed cameras have the ability to sacrifice spatial for temporal resolution, the findings herein suggest that Bayesian inference studies employing high-speed video should increase temporal resolutions at the expense of spatial resolution for reduced estimate uncertainties.
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Affiliation(s)
- Jonathan J Deng
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
| | - Paul J Hadwin
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
| | - Sean D Peterson
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario N2L 3G1, Canada
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Döllinger M, Gómez P, Patel RR, Alexiou C, Bohr C, Schützenberger A. Biomechanical simulation of vocal fold dynamics in adults based on laryngeal high-speed videoendoscopy. PLoS One 2017; 12:e0187486. [PMID: 29121085 PMCID: PMC5679561 DOI: 10.1371/journal.pone.0187486] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/18/2017] [Indexed: 12/18/2022] Open
Abstract
MOTIVATION Human voice is generated in the larynx by the two oscillating vocal folds. Owing to the limited space and accessibility of the larynx, endoscopic investigation of the actual phonatory process in detail is challenging. Hence the biomechanics of the human phonatory process are still not yet fully understood. Therefore, we adapt a mathematical model of the vocal folds towards vocal fold oscillations to quantify gender and age related differences expressed by computed biomechanical model parameters. METHODS The vocal fold dynamics are visualized by laryngeal high-speed videoendoscopy (4000 fps). A total of 33 healthy young subjects (16 females, 17 males) and 11 elderly subjects (5 females, 6 males) were recorded. A numerical two-mass model is adapted to the recorded vocal fold oscillations by varying model masses, stiffness and subglottal pressure. For adapting the model towards the recorded vocal fold dynamics, three different optimization algorithms (Nelder-Mead, Particle Swarm Optimization and Simulated Bee Colony) in combination with three cost functions were considered for applicability. Gender differences and age-related kinematic differences reflected by the model parameters were analyzed. RESULTS AND CONCLUSION The biomechanical model in combination with numerical optimization techniques allowed phonatory behavior to be simulated and laryngeal parameters involved to be quantified. All three optimization algorithms showed promising results. However, only one cost function seems to be suitable for this optimization task. The gained model parameters reflect the phonatory biomechanics for men and women well and show quantitative age- and gender-specific differences. The model parameters for younger females and males showed lower subglottal pressures, lower stiffness and higher masses than the corresponding elderly groups. Females exhibited higher subglottal pressures, smaller oscillation masses and larger stiffness than the corresponding similar aged male groups. Optimizing numerical models towards vocal fold oscillations is useful to identify underlying laryngeal components controlling the phonatory process.
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Affiliation(s)
- Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Pablo Gómez
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Rita R. Patel
- Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana, Indiana, United States of America
| | - Christoph Alexiou
- Section of Experimental Oncology and Nanomedicine (SEON), Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Else Kröner-Fresenius-Stiftung-Professorship, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Christopher Bohr
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Anne Schützenberger
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Medical School, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
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Galindo GE, Peterson SD, Erath BD, Castro C, Hillman RE, Zañartu M. Modeling the Pathophysiology of Phonotraumatic Vocal Hyperfunction With a Triangular Glottal Model of the Vocal Folds. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2017; 60:2452-2471. [PMID: 28837719 PMCID: PMC5831616 DOI: 10.1044/2017_jslhr-s-16-0412] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 04/19/2017] [Indexed: 05/08/2023]
Abstract
PURPOSE Our goal was to test prevailing assumptions about the underlying biomechanical and aeroacoustic mechanisms associated with phonotraumatic lesions of the vocal folds using a numerical lumped-element model of voice production. METHOD A numerical model with a triangular glottis, posterior glottal opening, and arytenoid posturing is proposed. Normal voice is altered by introducing various prephonatory configurations. Potential compensatory mechanisms (increased subglottal pressure, muscle activation, and supraglottal constriction) are adjusted to restore an acoustic target output through a control loop that mimics a simplified version of auditory feedback. RESULTS The degree of incomplete glottal closure in both the membranous and posterior portions of the folds consistently leads to a reduction in sound pressure level, fundamental frequency, harmonic richness, and harmonics-to-noise ratio. The compensatory mechanisms lead to significantly increased vocal-fold collision forces, maximum flow-declination rate, and amplitude of unsteady flow, without significantly altering the acoustic output. CONCLUSION Modeling provided potentially important insights into the pathophysiology of phonotraumatic vocal hyperfunction by demonstrating that compensatory mechanisms can counteract deterioration in the voice acoustic signal due to incomplete glottal closure, but this also leads to high vocal-fold collision forces (reflected in aerodynamic measures), which significantly increases the risk of developing phonotrauma.
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Affiliation(s)
- Gabriel E. Galindo
- Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Sean D. Peterson
- Mechanical and Mechatronics Engineering, University of Waterloo, Ontario, Canada
| | - Byron D. Erath
- Department of Mechanical & Aeronautical Engineering, Clarkson University, Potsdam, NY
| | - Christian Castro
- Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile
- School of Speech and Hearing Sciences, Universidad de Valparaíso, Chile
| | - Robert E. Hillman
- Center for Laryngeal Surgery & Voice Rehabilitation, Massachusetts General Hospital, Boston
- Harvard Medical School, Boston, MA
- MGH Institute of Health Professions, Boston, MA
| | - Matías Zañartu
- Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile
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Robertson D, Zañartu M, Cook D. Correction: Comprehensive, Population-Based Sensitivity Analysis of a Two-Mass Vocal Fold Model. PLoS One 2016; 11:e0156569. [PMID: 27231883 PMCID: PMC4883767 DOI: 10.1371/journal.pone.0156569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0148309.].
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