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Kinematic and Tectonic Significance of the Fold- and Fault- Related Fracture Systems in the Zagros Mountains, Southern IranMobasher, Katayoun 02 May 2007 (has links)
Enhancement methods applied on various satellite images (ASTER, ETM and RADAR SAT-1) facilitated the identification and mapping of tectonic fractures in the Zagros fold-and-thrust belt in southwest Iran. The results of the fracture analysis on these enhanced images reveal four principal fracture sets within each fold structure: (i) an axial set defined by normal faults oriented parallel to the fold axial trace, (ii) a cross-axial, extensional fracture set oriented perpendicular to the fold axial trace, (iii) and two sets of intersecting shear fractures, oriented at an acute angle to the cross-axial set. Study of the enhanced images also revealed five fracture sets along the Kazerun fault zone: (i) Riedel R- and R'-shear fracture sets, (ii) extensional T fracture set oriented at a high angle to the trace of the main Kazerun fault, (iii) oblique, synthetic P-shear fracture set, at a low angle to the trace of the main Kazerun fault, and (iv) synthetic Y-shear displacement fracture set, oriented sub-parallel to the main trace of the fault. The estimated mean azimuths of the shortening that developed the fold- and fault-related fracture systems are remarkably close, and are oriented perpendicular to the general NW-SE trend of the Zagros fold-and-thrust belt. The sampling and analysis of the fold- and fault-related fracture systems were done in a GIS environment. This study shows that an analysis of enhanced satellite images can reveal significant information on the deformation style, timing, and kinematics of the Zagros fold-and-thrust belt. This study suggests that the Zagros orogenic belt, which has mainly been forming since Miocene, due to the convergence of the Iranian and Arabian subplates, has evolved both by thin- and thick-skinned tectonics. Reconfiguration of the Precambrian basement blocks, and the ensuing slip and rotation along the Precambrian faults during the Zagros orogeny, have deformed the folds, and redistributed the fold-related fractures through rigid-body rotation.
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The Role of Systemic Dehydration in Vocal Fold HealingAnumitha Venkatraman (12437490) 20 April 2022 (has links)
<p>Systemic dehydration negatively alters epithelial cell junction markers and inflammatory mediators in vocal fold tissue. In other organs, dehydration canhave the following suboptimal outcomes; prolonged inflammation and delayed re-epithelization.It is surprising that the adverse role of systemic dehydration in vocal fold healing has not been directly demonstrated when dehydration has the potential to alter recovery following injury. The similarities between healing in dermal and mucosal tissue indicate an increased need to understand the effects of dehydration onvocal fold recovery.</p>
<p>Suboptimal vocal fold healing can have downstream consequences on vibratory function. Before functional voice changes can be delineated, there is a need to characterize the cellular interactions of systemic dehydration and vocal fold healing. The overarching research aim of this dissertation is to investigate the interaction of systemic dehydration and vocal fold healing on the gene expression of inflammatory and epithelial cell junction markers, following acute vocal fold injury.Gene expressionoutcomes werecompared in four groups;systemically-dehydrated,and euhydrated rats with minor, bilateral vocal fold injuriesand systemically-dehydrated and euhydrated rats without vocal fold injuries (N=9/group). We hypothesized that systemic dehydration(compared to euhydration)would cause an upregulation of pro and anti-inflammatory mediators with injury, but adownregulation of these inflammatory markers in the absence of injury. We also hypothesized that systemic dehydration(compared to euhydration)would cause a downregulation of epithelial cell junction markers with and without injury, butthat the effects of dehydration would be exacerbated with injury. </p>
<p>We found that the gene expression of pro-inflammatory cytokines was differentially expressed in systemically-dehydrated injured vocal old tissue when compared to systemically-euhydrated injured vocal fold tissue, 24 hours after vocal fold injury. These data lay the groundwork for future studies characterizing the later stages of interaction of systemic dehydration and injury.</p>
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Development of a 3D Computational Vocal Fold Model Optimization ToolVaterlaus, Austin C. 09 June 2020 (has links)
One of the primary objectives of voice research is to better understand the biomechanics of voice production and how changes in properties of the vocal folds (VFs) affect voice ability and quality. Synthetic VF models provide a way to observe how changes in geometry and material property affect voice biomechanics. This thesis seeks to evaluate an approach of using a genetic algorithm to design synthetic VF models in three ways: first, through the development of a computationally cost-effective 3D vocal fold model; second, by creating and optimizing a variation of this model; and third, by validating the approach. To reduce computation times, a user-defined function (UDF) was implemented in low-fidelity 2D and 3D computational VF models. The UDF replaced the conventional meshed fluid domain with the mechanical energy equation. The UDF was implemented in the commercial finite element code ADINA and verified to produce results that were similar to those of 2D and 3D VF models with meshed fluid domains. Computation times were reduced by 86% for 2D VF models and 74% for 3D VF models while core vibratory characteristic changes were less than 5%. The results from using the UDF demonstrate that computation times could be reduced while still producing acceptable results. A genetic algorithm optimizer was developed to study the effects of altering geometry and material elasticity on frequency, closed quotient (CQ), and maximum flow declination rate (MFDR). The objective was to achieve frequency and CQ values within the normal human physiological range while maximizing MFDR. The resulting models enabled an exploration of trends between objective and design variables. Significant trends and aspects of model variability are discussed. The results demonstrate the benefit of using a structured model exploration method to create models with desirable characteristics. Two synthetic VF models were fabricated to validate predictions made by models produced by the genetic algorithm. Fabricated models were subjected to tests where frequency, CQ, and sound pressure level were measured. Trends between computational and synthetic VF model responses are discussed. The results show that predicted frequency trends between computational and synthetic models were similar, trends for closed quotient were inconclusive, and relationships between MFDR and sound pressure level remained consistent. Overall, while discrepancies between computational and synthetic VF model results were observed and areas in need of further study are noted, the study results provide evidence of potential for using the present optimization method to design synthetic VF models.
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Geometry and Material Properties of Vocal Fold ModelsStevens, Kimberly Ann 01 July 2015 (has links) (PDF)
Voiced communication plays a fundamental role in society. Voice research seeks to improve understanding of the fundamental physics governing voice production, with the eventual goal of improving methods to diagnose and treat voice disorders. For this thesis, three different aspects of voice production research were studied. First, porcine vocal fold medial surface geometry was determined, and the three-dimensional geometric distortion induced by freezing the larynx, especially in the region of the vocal folds, was quantified. It was found that porcine vocal folds are qualitatively geometrically similar to canine and human vocal folds, as well as commonly used models, and that freezing of tissue in the larynx causes distortion of around 5%. Second, a setup of multiple high-resolution cameras and a stereo-endoscopy system simultaneously recorded positions on the superior surface of synthetic, self-oscillating vocal fold models to estimate the error in the measurement of the three-dimensional location by the stereo-endoscopy system. The error was found to be low in the transverse plane, whereas the error was relatively large in the inferior-superior direction, suggesting that the stereo-endoscope is applicable for in vivo measurements of absolute distances of the glottis in the transverse plane such as glottal length, width, and area. Third, a function for strain-varying Poisson's ratio for silicone was developed from experimental data. It is anticipated that the findings herein can aid voice researchers as they study voice production, leading to improved voice care.
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ANALYSIS OF VOCAL FOLD KINEMATICS USING HIGH SPEED VIDEOUnnikrishnan, Harikrishnan 01 January 2016 (has links)
Vocal folds are the twin in-folding of the mucous membrane stretched horizontally across the larynx. They vibrate modulating the constant air flow initiated from the lungs. The pulsating pressure wave blowing through the glottis is thus the source for voiced speech production. Study of vocal fold dynamics during voicing are critical for the treatment of voice pathologies. Since the vocal folds move at 100 - 350 cycles per second, their visual inspection is currently done by strobosocopy which merges information from multiple cycles to present an apparent motion. High Speed Digital Laryngeal Imaging(HSDLI) with a temporal resolution of up to 10,000 frames per second has been established as better suited for assessing the vocal fold vibratory function through direct recording. But the widespread use of HSDLI is limited due to lack of consensus on the modalities like features to be examined. Development of the image processing techniques which circumvents the need for the tedious and time consuming effort of examining large volumes of recording has room for improvement. Fundamental questions like the required frame rate or resolution for the recordings is still not adequately answered. HSDLI cannot get the absolute physical measurement of the anatomical features and vocal fold displacement. This work addresses these challenges through improved signal processing. A vocal fold edge extraction technique with subpixel accuracy, suited even for hard to record pediatric population is developed first. The algorithm which is equally applicable for pediatric and adult subjects, is implemented to facilitate user inspection and intervention. Objective features describing the fold dynamics, which are extracted from the edge displacement waveform are proposed and analyzed on a diverse dataset of healthy males, females and children. The sampling and quantization noise present in the recordings are analyzed and methods to mitigate them are investigated. A customized Kalman smoothing and spline interpolation on the displacement waveform is found to improve the feature estimation stability. The relationship between frame rate, spatial resolution and vibration for efficient capturing of information is derived. Finally, to address the inability to measure physical measurement, a structured light projection calibrated with respect to the endoscope is prototyped.
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Mechanisms and Consequences of Evolving a New Protein FoldKumirov, Vlad K. January 2016 (has links)
The ability of mutations to change the fold of a protein provides evolutionary pathways to new structures. To study hypothetical pathways for protein fold evolution, we designed intermediate sequences between Xfaso1 and Pfl6, two homologous Cro proteins that have 40% sequence identity but adopt all–α and α+β folds, respectively. The designed hybrid sequences XPH1 and XPH2 have 70% sequence identity to each other. XPH1 is more similar in sequence to Xfaso1 (86% sequence identity) while XPH2 is more similar to Pfl6 (80% sequence identity). NMR solution ensembles show that XPH1 and XPH2 have structures intermediate between Xfaso1 and Pfl6. Specifically, XPH1 loses α-helices 5 and 6 of Xfaso1 and incorporates a small amount of β-sheet structure; XPH2 preserves most of the β-sheet of Pfl6 but gains a structure comparable to helix 6 of Xfaso1. These findings illustrate that the sequence space between two natural protein folds may encode a range of topologies, which may allow a protein to change its fold extensively through gradual, multistep mechanisms. Evolving a new fold may have consequences, such as a strained conformation. Here we show that Pfl6 represents an early, strained form of the α+β Cro fold resulting from an ancestral remnant of the all-α Cro proteins retained after the fold switch. This nascent fold can be stabilized through deletion mutations in evolution, which can relieve the strain but may also negatively affect DNA-binding function. Compensatory mutations that increase dimerization appear to offset these effects to maintain function. These findings suggest that new folds can undergo mutational editing through evolution, which may occur in parallel pathways with slightly different outcomes.
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Inverted dartEurenius, Mario January 2016 (has links)
The field I’m working in is “design through construction”. Construction as a field in fashion design when creating has expanded and there are many views upon how one can work whit-in this field. I’m working with a cut and then bending or displacing it through placing it on the body so it creates volume which starts from its vertex. One could say that it works like an inverted dart. This way to work has a potential to create volume that stands out from the body without using standard ways e.g. like adding a new pattern piece or build a crinoline. It might answer to the question: How can one create shape or arrange shape without adding anchor points? Therefor I explore the relation between body and shape through inverted dart. I’ve been executing experiments through a trial and error method diverged in three steps when in the physi- cal part examine my aim in tests based on the body pressing a cut apart which gives an effect in the vertex of the cut. Through my research I’ve have come to a conclusion that the body in itself can transform garment trough an inverted dart by stepping into it. The relation between the body and material through the inverted dart has qualities were body can arrange dress and define it trough folding fabric and body can through the inverted dart make room for itself. This idea and development is relating to the basics when make dress, body and material and how we can work whit these opponents. Instead of thinking about new variables like new technical tools, e.g. the laser cutter when pushing boundaries one can also take new turns with basics. In this work the body defines dress through the inverted dart (an interaction between body and dress) and create new ways of handling fabric and shape. This perspective on design and art can also been used when working in other fields when distort basic prin- ciples to create new expression. As an example there might be possibilities to develop basics in architecture by studying society and therefore understand fundamental values in this field and, how you by change these variables can develop design.
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Kinematic Modeling of Asymmetric Vocal Fold VibrationSamlan, Robin Amy January 2012 (has links)
Asymmetries of the vocal folds and vocal fold vibration are key features underlying unilateral vocal fold motion impairment (VFMI). The knowledge of what particular asymmetries contribute to breathy voice and which asymmetries must be eliminated to re-establish normal voice will be important to improving evaluation and treatment of VFMI. It was hypothesized that several structural and vibratory asymmetries should lead to predictable changes in the glottal area, flow, and acoustic waveforms, and subsequently a perceived breathy voice quality. The purpose of this project was threefold: 1) to determine how specific vocal fold structural and vibratory asymmetries alter vocal function and perceived voice quality, 2) to determine the improvement in vocal function and voice quality in an abnormal voice with elimination of individual asymmetries, and 3) to develop a battery of vocal function measures that vary with dysphonia in a predictable manner. The approach was to use a computational kinematic model of vocal fold vibration that allows for differential left/right control of parameters such as vocal fold adduction, medial surface bulging, vibratory nodal point, phase, amplitude of vibration, and fundamental frequency. The resultant signals were subjected to aerodynamic and acoustic measurement as well as perceptual rating of voice quality. Results revealed that the degree of vocal process separation was the most influential parameter tested, though asymmetry of bulging, nodal point ratio, and starting phase worsened normal voice quality. Conversely, increased symmetry of bulging, nodal point ratio, amplitude of vibration and starting phase improved disordered voice quality. The amount of improvement to disordered voices varied based on the number of other asymmetries present. None of the six vocal function measures tested were primarily responsive to one particular model parameter, though four measures generally decreased as vocal process separation increased: maximum flow declination rate (MFDR), spectral slope (B0-B2), cepstral peak prominence (CPP), and harmonics-to-noise ratio (HNR). Two of the measures, MFDR and CPP, co-varied with each of the five parameters and robustly correlated with perceived severity.
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Universal Branched CoveringsTejada, Débora 05 1900 (has links)
In this paper, the study of k-fold branched coverings for which the branch set is a stratified set is considered. First of all, the existence of universal k-fold branched coverings over CW-complexes with stratified branch set is proved using Brown's Representability Theorem. Next, an explicit construction of universal k-fold branched coverings over manifolds is given. Finally, some homotopy and homology groups are computed for some specific examples of Universal k-fold branched coverings.
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Structural bioinformatics analysis of the family of human ubiquitin-specific proteasesZhu, Xiao January 2007 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
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