To see the other types of publications on this topic, follow the link: Diseases of vocal tract.
Dissertations / Theses on the topic 'Diseases of vocal tract'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Diseases of vocal tract.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Chytil, Pavel. "Detekce nemocí pomocí analýzy hlasu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-233419.
Full textAbstract:
Tato disertační práce je zaměřena na analýzu řečového signálu za učelem detekce nemocí ovlivňujících strukturu hlasových orgánů, obzvláště těch, které mění strukturální character hlasivek. Poskytnut je přehled současných technik. Dále jsou popsány zdroje použitých nahrávek pro zdravé a nemocné mlučí. Hlavním učelem této disertační práce je popsat vypočetní postup k odhadu parametrů modelu hlasového zdroje, které umožní následnou detekci a klasifikaci nemocí hlasivek. Poskytujeme detailní popis analýzy řečových signálů, které mohou být odvozeny z parametrických modelů hlasivek.
2
Wee, Keng Hoong. "An analog VLSI vocal tract." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43053.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 165-168).
Increasingly, circuit models of biology are being used to improve performance in engineering systems. For example, silicon-cochlea-like models have led to improved speech recognition in noise and low-power cochlear-implant processors for the deaf. A promising approach to improve the naturalness of synthetic speech is to exploit bioinspired models of speech production with low bit-rate control parameters. In this work, we present the first experimental integrated-circuit vocal tract by mapping fluid volume velocity to current, fluid pressure to voltage, and linear and nonlinear mechanical impedances to linear and nonlinear electrical impedances. The 275 jW analog vocal tract chip can be used with auditory processors in a feedback speech locked loop to implement speech recognition that is potentially robust in noise. Our use of a physiological model of the human vocal tract enables the analog vocal tract chip to synthesize speech signals of interest, using articulatory parameters that are intrinsically compact and linearly interpolatable. Previous attempts that take advantage of the powerful analysis-by-synthesis method employed computationally expensive approaches to articulatory synthesis using digital computation. Our strategy uses an analog vocal tract to drastically reduce power consumption, enables real-time performance and could be useful in portable speech processing systems of moderate complexity, e.g., in cell phones, digital assistants and bionic speech-prosthesis systems.
by Keng Hoong Wee.
Ph.D.
3
ITAKURA, Fumitada, Kazuya TAKEDA, and Hani C. YEHIA. "An Acoustically Oriented Vocal-Tract Model." Institute of Electronics, Information and Communication Engineers, 1996. http://hdl.handle.net/2237/15049.
Full text
4
Chen, Jer-Ming Physics Faculty of Science UNSW. "Vocal tract interactions in woodwind performance." Awarded by:University of New South Wales. Physics, 2009. http://handle.unsw.edu.au/1959.4/44626.
Full textAbstract:
How important is the player???s vocal tract in clarinet and saxophone performance? Acoustician???s opinions have ranged from ???negligible??? [Backus (1985), JASA 78, 17] to ???vocal tract resonance frequencies must match the frequency of the required notes??? [Clinch et al. (1982), Acustica 50, 280]. Musicians??? opinions are similarly varied. To understand how the tract-reed-bore system interacts, acoustical measurements of performers??? vocal tracts during playing were made using measurement heads mounted in the mouthpieces of a clarinet and a tenor saxophone. Acoustic impedance spectra of the tenor and soprano saxophone bores were also measured for all standard fingerings, and some others. For fingerings high in the tenor saxophone???s second register, bore impedance peaks downstream decrease with increasing pitch. Above the first 2.7 octaves, peak values fall below 30 MPa.s.m-3 and this ends the standard range available to amateurs. To play the higher altissimo notes, experts produced strong vocal tract resonances upstream with impedances 10-40 MPa.s.m-3 tuned to sound the desired note. While expert saxophonists adjust their vocal tract thus for altissimo playing, inexperienced players do not, and consequently cannot produce these notes. The smoothly rising clarinet glissando solo opening Gershwin???s Rhapsody in Blue was also investigated. Partially uncovering an open finger-hole smoothly raises clarinet resonances in the lower register, allowing continuous increases in playing pitch. When pitch bending in the second (clarino) register, experienced players produced strong tract resonances with impedances up to 60 MPa.s.m-3, comparable in magnitude with those of the clarinet bore (40-50 MPa.s.m-3). Thus during the glissando, sounding pitch is controlled by smoothly varying a strong resonance in the player???s vocal tract. The phase of the reed impedance is shown to make downwards pitch bending easier than upwards. Similar vocal tract adjustments were observed on the clarinet and saxophone for other advanced techniques such as bugling and multiphonic selection. During normal playing, although experienced players produced vocal tract impedance peaks with only moderate magnitude, these peaks were adjusted systematically to frequencies about 150 Hz higher than the sounding pitch (determined by strong bore resonances). This strategy may avoid the effects of small unwanted tract-bore interactions on sounding pitch.
5
Benkrid, A. "Real time TLM vocal tract modelling." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352958.
Full text
6
Pastel, Leah Marie Pfeifer. "Turbulent noise sources in vocal tract models." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14724.
Full textAbstract:
Thesis (Elec. E. and M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1988.Bibliography: leaves 108-110.
by Leah Marie Pfeifer Paste.
Elec.E.and M.S.
7
Blandin, Rémi. "Theoretical and experimental study of vocal tract acoustics." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT102/document.
Full textAbstract:
L'acoustique du conduit vocal est souvent décrite avec de simples modèles ondes planes à une dimension. Cependant, cela n'est pas satisfaisant quand à haute fréquence (à partir d'environ 5 kHz) des variations tridimensionnelles du champ acoustique sont présentes. La théorie acoustique multimodale a été implémentée pour prendre en compte les aspects tridimensionnels de l'acoustique du conduit vocal.Un système expérimental a été conçu pour mesurer avec précision des fonctions de transfert, des champs de pression et des diagrammes de directivité sur des maquettes de conduits vocaux. Les données expérimentales obtenues ont été comparées avec les simulations réalisées avec la théorie implémentée et avec la méthode des éléments finis. Le champ acoustique tridimensionnel et les diagrammes de directivité ont été prédit avec succès par les deux méthodes de simulation. Il a été observé que la propagation de mode acoustique d'ordre supérieur induit des variations tridimensionnelles du champ acoustique, génère des antirésonances et des résonances additionnelles et affecte la directivité du son rayonné de façon significative. L'excentricité de la forme du conduit vocal apparaît comme critique pour l'excitation et la propagation des modes d'ordre supérieur.Il est conclu qu'à haute fréquence (au-delà de 5 kHz), la fonction de transfert du conduit vocal peut avoir des variations significatives dans des intervalles de fréquences petit (de l'ordre de 100 Hz) et dans des régions angulaires restreintes (de l'ordre de 30°) qui nécessitent d'être prise en compte dans les études de la parole qui se focalisent sur les hautes fréquencesThe vocal tract acoustics is often described witha simple one dimensional plane wave approach.However, this is not satisfying when at high frequency(from about 5 kHz) three dimensional variations ofthe acoustic fieldare present. The multimodal acoustic theory has beenimplemented in order to account for the threedimensional aspects ofthe vocal tract acoustics.An experimental setup has been designed to measure accuratelytransfer functions, pressure field maps and directivitypatterns of vocal tract replicas.The experimental data obtained have been compared withsimulations performed with the implemented theory andwith a finite element method.The three dimensional acoustic fields and the directivitypatterns were successfully predicted by both simulationmethods.It has been observed that the propagation of higher orderacoustical modes, induces three dimensional variations ofthe acoustic field, generates anti-resonances andadditional resonances, and significantly affects the directivityof the radiated sound.The eccentricity of thevocal tract shape appears as critical for the excitation and thepropagation of the higher order acoustical modes.It is concluded thatat high frequency (above 5 kHz), the transfer functionof the vocal tract can have significant variationswithin short frequency intervals (of the order of 100Hz) and within small angular regions (of the order of30°) which need to be taken into account inthe studies of speech which focus on high frequencies
8
Shiga, Yoshinori. "Precise estimation of vocal tract and voice source characteristics." Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/940.
Full textAbstract:
This thesis addresses the problem of quality degradation in speech produced by parameter-based speech synthesis, within the framework of an articulatory-acoustic forward mapping. I first investigate current problems in speech parameterisation, and point out the fact that conventional parameterisation inaccurately extracts the vocal tract response due to interference from the harmonic structure of voiced speech. To overcome this problem, I introduce a method for estimating filter responses more precisely from periodic signals. The method achieves such estimation in the frequency domain by approximating all the harmonics observed in several frames based on a least squares criterion. It is shown that the proposed method is capable of estimating the response more accurately than widely-used frame-by-frame parameterisation, for simulations using synthetic speech and for an articulatory-acoustic mapping using actual speech. I also deal with the source-filter separation problem and independent control of the voice source characteristic during speech synthesis. I propose a statistical approach to separating out the vocal-tract filter response from the voice source characteristic using a large articulatory database. The approach realises such separation for voiced speech using an iterative approximation procedure under the assumption that the speech production process is a linear system composed of a voice source and a vocal-tract filter, and that each of the components is controlled independently by different sets of factors. Experimental results show that controlling the source characteristic greatly improves the accuracy of the articulatory-acoustic mapping, and that the spectral variation of the source characteristic is evidently influenced by the fundamental frequency or the power of speech. The thesis provides more accurate acoustical approximation of the vocal tract response, which will be beneficial in a wide range of speech technologies, and lays the groundwork in speech science for a new type of corpus-based statistical solution to the source-filter separation problem.
9
Pruthi, Tarun. "Analysis, vocal-tract modeling, and automatic detection of vowel nasalization." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/4273.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
10
Clegg, Margaret. "The comparative anatomy and evolution of the human vocal tract." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271140.
Full text
11
Story, Brad H., and Kate Bunton. "An acoustically-driven vocal tract model for stop consonant production." ELSEVIER SCIENCE BV, 2017. http://hdl.handle.net/10150/623128.
Full textAbstract:
The purpose of this study was to further develop a multi-tier model of the vocal tract area function in which the modulations of shape to produce speech are generated by the product of a vowel substrate and a consonant superposition function. The new approach consists of specifying input parameters for a target consonant as a set of directional changes in the resonance frequencies of the vowel substrate. Using calculations of acoustic sensitivity functions, these "resonance deflection patterns" are transformed into time-varying deformations of the vocal tract shape without any direct specification of location or extent of the consonant constriction along the vocal tract. The configuration of the constrictions and expansions that are generated by this process were shown to be physiologically-realistic and produce speech sounds that are easily identifiable as the target consonants. This model is a useful enhancement for area function-based synthesis and can serve as a tool for understanding how the vocal tract is shaped by a talker during speech production. (C) 2016 Elsevier B.V. All rights reserved.
12
Poznyakovskiy, Anton A., Alexander Mainka, Ivan Platzek, and Dirk Mürbe. "A Fast Semiautomatic Algorithm for Centerline-Based Vocal Tract Segmentation." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-202661.
Full textAbstract:
Vocal tract morphology is an important factor in voice production. Its analysis has potential implications for educational matters as well as medical issues like voice therapy. The knowledge of the complex adjustments in the spatial geometry of the vocal tract during phonation is still limited. For a major part, this is due to difficulties in acquiring geometry data of the vocal tract in the process of voice production. In this study, a centerline-based segmentation method using active contours was introduced to extract the geometry data of the vocal tract obtained with MRI during sustained vowel phonation. The applied semiautomatic algorithm was found to be time- and interaction-efficient and allowed performing various three-dimensional measurements on the resulting model. The method is suitable for an improved detailed analysis of the vocal tract morphology during speech or singing which might give some insights into the underlying mechanical processes.
13
Mohammad, A. S. Mohammad. "Dynamic measurements of speech articulators using magnetic resonance imaging." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297609.
Full text
14
Boegli, Susan K. "Vocal-tract normalisation : the contribution of information from beyond the syllable." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389629.
Full text
15
Hao, Jianping. "CROSS-RACIAL STUDIES OF HUMAN VOCAL TRACT DIMENSIONS AND FORMANT STRUCTURES." Ohio University / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1020776535.
Full text
16
Chiu, Wilson Sien Chun. "The development of an enhanced electropalatography system for speech research." Thesis, University of Southampton, 1995. https://eprints.soton.ac.uk/250160/.
Full textAbstract:
To understand how speech is produced by individual human beings, it is fundamentally important to be able to determine exactly the three-dimensional shape of the vocal tract. The vocal tract is inaccessible so its exact form is difficult to determine with live subjects. There is a wide variety of methods that provide information on the vocal tract shape. The technique of Electropalatography (EPG) is cheap, relatively simple, non-invasive and highly informative. Using EPG on its own, it is possible to deduce information about the shape, movement and position of tongue-palate contact during continuous speech. However, data provided by EPG is in the form of a two-dimensional representation in which all absolute positional information is lost. This thesis describe the development of an enhanced Electropalatography (eEPG) system, which retains most of the advantages of EPG while overcoming some of the disadvantages by representing the three-dimensional (3D) shape of the palate. The eEPG system uses digitised palate shape data to display the tongue-palate contact pattern in 3D. The 3D palate shape is displayed on a Silicon Graphics workstation as a surface made up of polygons represented by a quadrilateral mesh. EPG contact patterns are superimposed onto the 3D palate shape by displaying the relevant polygons in a different colour. By using this system, differences in shape between individual palates, apparent on visual inspection of the actual palates, are also apparent in the image on screen. The contact patterns can be related more easily to articulatory features such as the alveolar ridge since the ridge is visible on the 3D display. Further, methods have been devised for computing absolute distances along paths lying on the palate surface. Combining this with calibrated palate shape data allows measurements accurate to 1 mm to be made between contact locations on the palate shape. These have been validated with manual measurements. The sampling rate for EPG is 100Hz and the data rate is equivalent to 62 bits per 10ms. In the past few years, some coding (parameterization) methods have been introduced to try to reduce the amount of data while retaining the important aspects. Feature coding methods are proposed here and several parameters are investigated, expressed in terms of both conventional measures such as row number, and in absolute measures of distance and area (i.e. mm and mm2). Features studied include location of constriction and degree of constriction. Finally, in order to reduce the amount of data while retaining the spatial information, composite frames that represent a series of EPG frames are computed. Measures of goodness of the composite frames that do and do not use 3D data are described. Some example are given in which fricative data has been processed by generating a composite frame for the entire fricative, and computing an area estimate for each row of the composite frame using the assumption of a flat tongue. This thesis demonstrates the current capability and inherent flexibility of the enhanced electropalatography system. In the future, the eEPG system can be extended to compute volume estimates again using a flat tongue model. By incorporating information on the tongue surface provided by other imaging methods such as ultrasound, more accurate area and volume estimates can be obtained.
17
Foresman, Bryant R. "Acoustical measurement of the human vocal tract: quantifying speech & throat-singing." Pomona College, 2008. http://ccdl.libraries.claremont.edu/u?/stc,43.
Full textAbstract:
The field of biological acoustics has witnessed a steady increase in the research into overtone singing, or “throat-singing,” in which a singer utilizes resonance throughout the vocal tract to sing melodies with the overtones created by a vocal drone. Recent research has explored both how a singer vocalizes in order to obtain rich harmonics from a vocal drone, as well as how further manipulations of the vocal apparatus function to filter and amplify selected harmonics. In the field of phonetics, vowel production is quantified by measuring the frequencies of vocal tract resonances, or formants, which a speaker manipulates to voice a particular vowel. Thus, an investigation of throat singing is closely linked to human speech production. Formants are usually detected in vowel spectra obtained using Fast Fourier Transform algorithms (FFTs). An alternative method that provides much higher frequency resolution is external excitation of the vocal tract and measurement of the pressure response signal at the mouth’s opening, which can be used to calculate the acoustic impedance spectrum. We demonstrate the use of such an “acoustic impedance meter” to measure the formant frequencies of common vowels as well as the oscillatory modes of simple resonant pipe systems. The impedance meter accurately measures fundamental pipe modes and a variety of formant frequencies with an uncertainty of 1 Hz. Finally, we assess how the impedance meter may be used to measure the unique resonances achieved by qualified throat singers.
18
Mullen, Jack. "Physical modelling of the vocal tract with the 2D digital waveguide mesh." Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440986.
Full text
19
GarciÌa, MariÌa Susana Avila. "Automatic tracking of 3D vocal tract features during speech production using MRI." Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437111.
Full text
20
Mainka, Alexander, Anton Poznyakovskiy, Ivan Platzek, Mario Fleischer, Johan Sundberg, and Dirk Mürbe. "Lower Vocal Tract Morphologic Adjustments Are Relevant for Voice Timbre in Singing." Public Library of Science, 2015. https://tud.qucosa.de/id/qucosa%3A29495.
Full textAbstract:
The vocal tract shape is crucial to voice production. Its lower part seems particularly relevant for voice timbre. This study analyzes the detailed morphology of parts of the epilaryngeal tube and the hypopharynx for the sustained German vowels /a/, /e/, /i/, /o/, and /u/ by thirteen male singer subjects who were at the beginning of their academic singing studies. Analysis was based on two different phonatory conditions: a natural, speech-like phonation and a singing phonation, like in classical singing. 3D models of the vocal tract were derived from magnetic resonance imaging and compared with long-term average spectrum analysis of audio recordings from the same subjects. Comparison of singing to the speech-like phonation, which served as reference, showed significant adjustments of the lower vocal tract: an average lowering of the larynx by 8 mm and an increase of the hypopharyngeal cross-sectional area (+ 21.9%) and volume (+ 16.8%). Changes in the analyzed epilaryngeal portion of the vocal tract were not significant. Consequently, lower larynx-to-hypopharynx area and volume ratios were found in singing compared to the speech-like phonation. All evaluated measures of the lower vocal tract varied significantly with vowel quality. Acoustically, an increase of high frequency energy in singing correlated with a wider hypopharyngeal area. The findings offer an explanation how classical male singers might succeed in producing a voice timbre with increased high frequency energy, creating a singer‘s formant cluster.
21
Poznyakovskiy, Anton A., Alexander Mainka, Ivan Platzek, and Dirk Mürbe. "A Fast Semiautomatic Algorithm for Centerline-Based Vocal Tract Segmentation: Research Article." Hindawi, 2015. https://tud.qucosa.de/id/qucosa%3A29494.
Full textAbstract:
Vocal tract morphology is an important factor in voice production. Its analysis has potential implications for educational matters as well as medical issues like voice therapy. The knowledge of the complex adjustments in the spatial geometry of the vocal tract during phonation is still limited. For a major part, this is due to difficulties in acquiring geometry data of the vocal tract in the process of voice production. In this study, a centerline-based segmentation method using active contours was introduced to extract the geometry data of the vocal tract obtained with MRI during sustained vowel phonation. The applied semiautomatic algorithm was found to be time- and interaction-efficient and allowed performing various three-dimensional measurements on the resulting model. The method is suitable for an improved detailed analysis of the vocal tract morphology during speech or singing which might give some insights into the underlying mechanical processes.
22
Mainka, Alexander, Anton Poznyakovskiy, Ivan Platzek, Mario Fleischer, Johan Sundberg, and Dirk Mürbe. "Lower Vocal Tract Morphologic Adjustments Are Relevant for Voice Timbre in Singing." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-202679.
Full textAbstract:
The vocal tract shape is crucial to voice production. Its lower part seems particularly relevant for voice timbre. This study analyzes the detailed morphology of parts of the epilaryngeal tube and the hypopharynx for the sustained German vowels /a/, /e/, /i/, /o/, and /u/ by thirteen male singer subjects who were at the beginning of their academic singing studies. Analysis was based on two different phonatory conditions: a natural, speech-like phonation and a singing phonation, like in classical singing. 3D models of the vocal tract were derived from magnetic resonance imaging and compared with long-term average spectrum analysis of audio recordings from the same subjects. Comparison of singing to the speech-like phonation, which served as reference, showed significant adjustments of the lower vocal tract: an average lowering of the larynx by 8 mm and an increase of the hypopharyngeal cross-sectional area (+ 21.9%) and volume (+ 16.8%). Changes in the analyzed epilaryngeal portion of the vocal tract were not significant. Consequently, lower larynx-to-hypopharynx area and volume ratios were found in singing compared to the speech-like phonation. All evaluated measures of the lower vocal tract varied significantly with vowel quality. Acoustically, an increase of high frequency energy in singing correlated with a wider hypopharyngeal area. The findings offer an explanation how classical male singers might succeed in producing a voice timbre with increased high frequency energy, creating a singer‘s formant cluster.
23
Hanna, Noël. "Enquêtes de l'acoustique du conduit vocal et des plis vocaux in vivo, ex vivo et in vitro." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENS033/document.
Full textAbstract:
La parole et le chant ont une importance capitale dans la culture humaine. Cependant les phénomènes physiques de production et de contrôle de la voix sont encore mal compris, et leurs paramètres mal connus, principalement en raison de la difficulté d'y accéder in vivo. Dans le modèle source-filtre simplifié, la source sonore est produite par l'oscillation des plis vocaux à une fréquence fondamentale et ses multiples ; les résonances du conduit vocal filtrent l'enveloppe spectrale du signal pour produire des voyelles. Dans cette thèse, les propriétés de la source et du filtre sont étudiées et une expérience in vitro examine l'influence du filtre sur la source. L'influence des paramètres de contrôle aérodynamiques ou mécaniques sur la fréquence fondamentale est étudiée ex vivo en utilisant des larynx humains excisés. Quatre types de discontinuités ou d'hystérésis sont observés. En dehors de ces zones de bifurcation, la fréquence fondamentale est approximativement proportionnelle à la racine carrée de la pression sous-glottique, ce qui a des implications pour le chant et de la parole, en particulier dans les langues tonales. De plus, le flux d'air qui traverse la glotte provoque un rétrécissement du conduit aryépiglottique sous l'effet de forces de pression aérodynamique, et peut initier l'oscillation des plis ventriculaires et/ou aryépiglottiques sans contrôle musculaire. L'impédance acoustique de conduits vocaux fut mesurée in vivo sur un intervalle de9 octaves en fréquence et de 80 dB en amplitude, avec la glotte fermée puis pendant la phonation. Les fréquences, amplitudes et largeurs de bande des résonances acoustiques et des résonances mécaniques des tissus autour du conduit vocal sont estimées. Lorsque la glotte est fermée, les largeurs de bande et les pertes d'énergie correspondantes dans le conduit vocal sont largement supérieures aux pertes viscothermiques d'un cylindre rigide lisse, et sont encore plus importantes pendant la phonation. En utilisant un modèle simple de conduit vocal et les mesures effectuées en inspirant, des résonances acoustiques du système sous-glottique sont également estimées. Les effets possibles de la charge aéroacoustique du filtre sur la source sont mis en évidence dans une expérience sur une maquette de plis vocaux constituée de boudins de latex remplis d'eau couplés à un tuyau rigide. La modification de la charge acoustique en aval des plis vocaux, par insertion d'une paille à l'extrémité du conduit, modifie la fréquence fondamentale de vibration des plis. Ce résultat est discuté dans le contexte des méthodes de rééducation orthophonique à la paille couramment utilisées en thérapie de la paroleSpeech and singing are of enormous importance to human culture, yet the physics that underlies the production and control of the voice is incompletely understood, and its parameters not well known, mainly due to the difficulty of accessing them in vivo. In the simplified but well-accepted source-filter model, non-linear vocal fold oscillation produces a sound source at a fundamental frequency and its multiples, the resonances of the vocal tract filter the spectral envelope of the sound to produce voice formants. In this thesis, both source and tract properties are studied experimentally and an in vitro experiment investigates how the filter can affect the source. The control of fundamental frequency by either air supply or mechanical control parameters is investigated ex vivo using excised human larynges. All else equal, and excluding the four types of discontinuity or hysteresis observed, the fundamental frequency was found to be proportional to the square root of subglottal pressure, which has implications for singing and speech production, particularly in tonal languages. Additionally, airflow through the glottis causes a narrowing of the aryepiglottic tube and can initiate ventricular and/or aryepiglottic fold oscillation without muscular control. The acoustic impedance of the vocal tract was measured in vivo over a range of 9 octaves and 80 dB dynamic range with the glottis closed and during phonation. The frequencies, magnitudes and bandwidths were measured for the acoustic and for the mechanical resonances of the surrounding tissues. The bandwidths and the energy losses in the vocal tract that cause them were found to be five-fold higher than the viscothermal losses of a dry, smooth rigid cylinder, and to increase during phonation. Using a simple vocal tract model and measurements during inhalation, the subglottal system resonances were also estimated. The possible effects of the filter on the source are demonstrated in an experiment on a water-filled latex vocal fold replica: changing the aero-acoustic load of the model tract by inserting a straw at the model lips changes the fundamental frequency. This result is discussed in the context of straw phonation used in speech therapy
24
Ma, Zongqiang. "Spontaneous speech recognition using statistical dynamic models for the vocal-tract-resonance dynamics." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/NQ53993.pdf.
Full text
25
Kharitonov, Sergei Alexandrovich. "Exhaled nitric oxide in airway diseases." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266411.
Full text
26
Hofe, Robin. "Biomimetic vocal tract modelling : an artificial speaker to investigate the energetics of speech production." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543237.
Full text
27
Loasby, J. M. "Real time transmission line modelling of the vocal tract using multiple digital signal processors." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339551.
Full text
28
Nishimura, Takeshi. "Studies on the ontogenetic changes in the shape of the vocal tract in chimpanzees." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149148.
Full text
29
Gray, Calum David. "Acoustic pulse reflectometry for measurement of the vocal tract and application in voice synthesis." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/13947.
Full textAbstract:
In this thesis, the basic theory describing wave propagation in tubes of varying cross-section is outlined, together with a review of how the time domain technique of APR can be used to measure the input impulse response of a tubular object, such as the vocal tract, from which the bore profile can be calculated using the layer peeling algorithm. Experimental measurements of the human vocal tract during the phonation (imitation of) for five non-nasalised vowels [a, e, i, o, u] are presented, using recent enhancements to the APR technique (MLS excitation signals and virtual DC tube method) for a single subject, together with optimisation of the APR technique for vocal tract measurement and its application in a group study using adults and children. To validate the results obtained using the APR technique, a comparative study with an accepted ‘gold standard’ imaging technique (MRI) is presented, using the same subject, a voice professional, in both studies. The results from this study show reasonable overall agreement between the APR and MRI data, with the limited resolution of the acoustic technique tending to broaden features and underestimate cross sectional areas, particularly in the region of the pharynx and glottis. Protocols and supplementary documentation required by scientific, clinical and ethical review bodies for the use of human volunteers in research trials are documented. From this study a data corpus of vocal tract measurements is gathered, using the techniques of APR and MRI, in adult males, adult females and children. In concluding, limitations of the APR technique for vocal tract measurement are discussed and potential improvements are proposed.
30
Nijhuis, Anke. "Roles of microRNAs in diseases of the human gastrointestinal tract." Thesis, Queen Mary, University of London, 2015. http://qmro.qmul.ac.uk/xmlui/handle/123456789/9547.
Full textAbstract:
Crohn's disease (CD) and colorectal cancer (CRC) are major disorders of the intestine. Inflammation in CD often precedes fibrosis and stricture formation, and is linked to increased cancer risk. Hypoxia is a common feature of inflammation and CRC that can severely compromise the effectiveness of current therapy regimes including chemo-radiotherapy and maintenance of remission in CD patients. MicroRNAs (miRNAs) are key regulatory molecules involved in cellular proliferation, apoptosis and fibrosis, which are all modulated by hypoxia. This thesis aims to understand the role of miRNAs in these two intestinal diseases. Microarray profiling identified differentially expressed miRNA in the intestinal mucosa overlying strictured and non-strictured CD tissue samples and in six CRC cell lines cultured in hypoxic conditions compared to normoxia. Validation experiments using qRT-PCR confirmed the differential expression of miR-29a, -29b, -29c, -34a, -493* and -708 in CD mucosa and miR-21, -210, -30d, -320a, -320b and -320c in CRC cell lines. Functionally, over-expression of miR-29b in CD intestinal fibroblasts modulated the down-regulation of collagen I and III transcripts and collagen III protein in a TGF-β-dependent manner. Furthermore, miR-29b induced indirectly the expression of the anti-apoptotic protein Mcl-1 via the cytokines IL-6 and IL-8. A positive correlation between miR-210 and the hypoxia marker CAIX was found in CRC tissue in vivo. Furthermore, HCT116 cells cultured under hypoxia were more resistant to the chemotherapy drug 5-FU than cells grown under normoxia. Knockdown of miR-21 or miR-30d under hypoxia may sensitise CRC cells to 5-FU. CRC cell lines grown under hypoxic conditions present an altered cellular metabolic profile compared to their normoxic counterparts. This thesis has showed that critical miRNAs have a functional role in the progression of two important diseases of the intestine. The work presented highlights the potential of miRNAs as biomarkers and therapeutic targets to improve the clinical management of patients with digestive diseases.
31
Chromek, Milan. "Urinary tract infection and renal scarring /." Stockholm, 2006. http://diss.kib.ki.se/2006/7140-844-4/.
Full text
32
Jackson, Philip J. B. "Characterisation of plosive, fricative and aspiration components in speech production." Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/254111/.
Full textAbstract:
This thesis is a study of the production of human speech sounds by acoustic modelling and signal analysis. It concentrates on sounds that are not produced by voicing (although that may be present), namely plosives, fricatives and aspiration, which all contain noise generated by flow turbulence. It combines the application of advanced speech analysis techniques with acoustic flow-duct modelling of the vocal tract, and draws on dynamic magnetic resonance image (dMRI) data of the pharyngeal and oral cavities, to relate the sounds to physical shapes. Having superimposed vocal-tract outlines on three sagittal dMRI slices of an adult male subject, a simple description of the vocal tract suitable for acoustic modelling was derived through a sequence of transformations. The vocal-tract acoustics program VOAC, which relaxes many of the assumptions of conventional plane-wave models, incorporates the effects of net flow into a one-dimensional model (viz., flow separation, increase of entropy, and changes to resonances), as well as wall vibration and cylindrical wavefronts. It was used for synthesis by computing transfer functions from sound sources specified within the tract to the far field. Being generated by a variety of aero-acoustic mechanisms, unvoiced sounds are somewhat varied in nature. Through analysis that was informed by acoustic modelling, resonance and anti-resonance frequencies of ensemble-averaged plosive spectra were examined for the same subject, and their trajectories observed during release. The anti-resonance frequencies were used to compute the place of occlusion. In vowels and voiced fricatives, voicing obscures the aspiration and frication components. So, a method was devised to separate the voiced and unvoiced parts of a speech signal, the pitch-scaled harmonic filter (PSHF), which was tested extensively on synthetic signals. Based on a harmonic model of voicing, it outputs harmonic and anharmonic signals appropriate for subsequent analysis as time series or as power spectra. By applying the PSHF to sustained voiced fricatives, we found that, not only does voicing modulate the production of frication noise, but that the timing of pulsation cannot be explained by acoustic propagation alone. In addition to classical investigation of voiceless speech sounds, VOAC and the PSHF demonstrated their practical value in helping further to characterise plosion, frication and aspiration noise. For the future, we discuss developing VOAC within an articulatory synthesiser, investigating the observed flow-acoustic mechanism in a dynamic physical model of voiced frication, and applying the PSHF more widely in the field of speech research.
33
Smith, Heather, Chaya Nanjundeswaran, and Brenda Louw. "Vocal Health: Awareness and Perceptions in Undergraduate Vocal Music and Theatre Majors." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/7762.
Full textAbstract:
Objective: The purpose of this study was to identify the perceptions of students majoring in vocal music and theatre, regarding the instruction they received in their undergraduate curriculum on vocal health education. Research questions focused on perceptions of: (a) vocal hygiene strategies, (b) the connection between the speaking and singing voice, (c) vocal rehabilitation and the professionals to contact and (d) students’ level of trust for their voice teacher.
Methods: A descriptive research design with qualitative analysis was used to explore the research questions. A survey was developed by adapting questions from a similar study by Beeman (2016). Permission was granted for the adaption by the author. The survey went through two stages of review and revision by an expert panel of professionals across vocal music and theatre, followed by a pilot study of 13 undergraduate vocal music majors. The final survey contained 57 items, incorporating two forms of questions, a 6-point Likert scale and multiple choice. It was disseminated to undergraduate vocal music and theatre majors across the United States via Survey Monkey TM.
Results: Students reported receiving knowledge on vocal health from their voice teachers and implementing it. However, they indicated low levels of compliance for specific vocal hygiene parameters. Additionally, students recognized the connection between the singing and speaking voice, they were unclear of the role of the speech-language pathologist in voice care, and they indicated trust in their voice teacher as it pertained to their voice and personal life.
Conclusions: A new approach to promote understanding and compliance of voice care strategies needs to be implemented in the undergraduate setting. Connecting both performance majors and speech-language pathology majors in an interprofessional education collaboration may prove to be mutually beneficial to both the clinician and the performer
34
Dell\'Acqua, Raquel Malara. "Análise acústica da voz de obesos mórbidos pré e pós tratamento cirúrgico para a obesidade." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-13022008-121848/.
Full textAbstract:
Devido ao grande aumento da obesidade no Brasil e no mundo e aos riscos que esta afecção oferece à saúde dos indivíduos, existem diversos tipos de tratamento possíveis para reverter esse quadro. Entre eles, o tratamento cirúrgico, que é o mais indicado para os casos classificados como obesidade mórbida. Por meio desse tratamento é comumente possível a redução de até 40% do peso inicial do indivíduo. Contudo, existem casos em que a perda ultrapassa esse percentual. Com essa perda de gordura tão significativa, o organismo todo apresenta modificações nitidamente observáveis, e tais alterações incluem o trato vocal. Sabendo que a voz é um sinal complexo composto pelo sinal vocal produzido na glote e pelas ressonâncias do trato vocal, observou-se a necessidade de avaliar se os parâmetros vocais sofrem alteração com a drástica mudança de peso corpóreo. Este estudo comparou as análises acústicas e perceptivo-auditivas antes e depois do tratamento cirúrgico para a obesidade, tendo como objetivo verificar se alterações vocais acontecem após o emagrecimento. Os resultados apontam que nas perdas de peso de até 40%, os parâmetros perceptivo auditivos e os acústicos não apresentaram alterações estatisticamente relevantes, e para perdas maiores que 50% observou-se a alteração significativa em dois parâmetros específicos, o PA e o Ex, o que significa: melhora na movimentação das pregas vocais com aumento de ruído na voz após o emagrecimento. Contudo, a amostra que compõe esse percentual de perda de peso é composta por apenas um participante, portanto tais resultados não podem ser generalizados.Due to the significant increase of obesity in Brazil and in the world and the risks involving the health of individuals, several types of treatment have been recommended in an attempt to change this scenario. The surgical treatment is believed to be the most suitable for the majority of morbid obesity cases. This type of procedure usually reduces up to 40% of the individual initial weight and in some cases this ratio can be even higher. However, a significant weight loss usually results in several significant bodily changes including the vocal tract. As the voice signal is very complex and comprises a glottal pulse equalized by vocal tract resonance, it seems reasonable to evaluate how voice parameters change with weight reduction. The purpose of this study is to compare perceptive-auditive and acoustics analysis of the voice, before and after the surgical approach to obesity to check if the vocal changes occur after the weight reduction. The results indicate that in weight losses up to 40% the perceptive-auditive and acoustics parameters did not represent statistically relevant alterations, but in weight losses higher than 50%, significant changes were observed in two specific parameters, PA and Ex, including improvement of vocal folds movement and increase of loudness of voice after weight loss. However, the sample of weight loss was insufficient because it was limited to one participant; therefore it should not be generalized.
35
South, Allan John. "Some effects of the military cockpit environment on speech production." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343330.
Full text
36
Panchapagesan, Sankaran. "Frequency warping by linear transformation, and vocal tract inversion for speaker normalization in automatic speech recognition." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1610480121&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Full text
37
Almond, Elizabeth Jennifer Philippa. "Epstein-Barr virus infection of the lower respiratory tract." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31208484.
Full text
38
Cheung, Yim, and 張艷. "Comparative analysis of metallic stenting versus surgical bypass in the management of malignant biliary obstruction." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206556.
Full textAbstract:
Malignant obstructive jaundice is always encountered in advanced stage. Malignancies include Distal Bile duct Carcinoma, Ampulla of Vater Carcinoma, and Pancreas Carcinoma are sometimes impossible to cure and resect. Therefore, palliative treatments are the only way to relieve the disease for the patients to have a better quality of life in their remaining life- span. Available palliative treatments include stenting and surgical bypass. In our analysis, metallic stenting and double bypass composing hepaticojejunostomy and gastrojejunostomy are studied as they can be considered as the two most efficient palliative methods so far that are widely used in Hong Kong in the management of malignant biliary obstruction. The treatment options depends on both the physicians and the patient. However, patients are often on the horns of a dilemma when they are allowed to choose these palliative treatments.
This study hence aim to compare the cost-effectiveness of metallic stenting and surgical double bypass palliative treatment among five factors: 1) Number of hospital stay, 2) Re-admission rate, 3) Overall complication, 4) Change of bilirubin level and 5) Survival rate. A total of 40 patients data are being retrieved from the Queen Mary Hospital as 20 data are form the metallic stenting group, while the other 20 data are from surgical bypass.
After collecting the data and finishing the study, it was found that apart from a longer hospital stay, the surgical bypass patient group would generally have a lower re-admission and complication rate. While the parameters include bilirubin change before and after the treatment and the survival rate are not significantly different, which indicated these two parameters may not be the determining factors when deciding the treatment choice.
Based on the research outcome, surgical bypass may be a better choice of palliative treatment in the management of Malignant Biliary Obstruction that allows patients to obtain a better quality of life.published_or_final_version
Medicine
Master
Master of Medical Sciences
39
Wong, Chun-nin Adam, and 黃春年. "Analyses of influenza viral cytopathic effect in human lower respiratory tract." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41290860.
Full text
40
Riede, Tobias. "Vocal changes in animals during disorders." Doctoral thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959876065.
Full text
41
Chen, Hong-I. "Physiological and pharmacological studies of lower urinary tract smooth muscles." Thesis, University of Oxford, 1990. http://ora.ox.ac.uk/objects/uuid:e73d80a0-9cfd-4959-bfc7-cd2576fcc1dc.
Full text
42
Coelho, Fabiana Moura. "A influência da configuração do trato vocal na sonoridade da flauta." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/27/27157/tde-05112014-092753/.
Full textAbstract:
O presente trabalho busca demonstrar de forma objetiva a influência das diferentes configurações de trato vocal na sonoridade da flauta. As alterações ocorridas na sonoridade do instrumento são, em geral, percebidas empiricamente pelos músicos a partir de imagens mentais acerca da configuração de seu trato vocal. Todavia, não há, entre os flautistas, uma visão mais clara e objetiva dos fenômenos ocorridos para que as alterações de timbre se viabilizem. Isso se deve, em grande parte, ao considerável número de variáveis envolvidas, como o ângulo de incidência do jato de ar no orifício do instrumento, movimentos de mandíbula, pressão do jato, entre outros. Considerando-se que as alterações de timbre são elemento essencial da interpretação musical e compõem não apenas o vocabulário técnico do instrumentista, mas, sobretudo, seu vocabulário criativo e sua sensibilidade musical, foi realizado um experimento que procurou mostrar com maior objetividade o papel do trato vocal nas alterações de timbre da flauta. O experimento consistiu em um aparato composto por um fonte de ar, um tanque/pulmão, modelos de trato vocal, embocadura artificial e o instrumento. Os resultados foram gravados e, posteriormente, analisados e comparados às medidas de impedância dos protótipos de trato vocal construídos para o experimento. Foram também realizadas entrevistas qualitativas com flautistas profissionais e professores com larga experiência na execução e no ensino do instrumento, que agregaram elementos à análise. A partir desses elementos, foram constatadas evidências contundentes de que as diferentes configurações do trato vocal são capazes de modificar a sonoridade da flauta.The main objective of this research is to objectively demonstrate the influence of changes in the configuration of the vocal tract on the sound of the flute. These alterations are generally noticed empirically by musicians and are represented by mental images of the configuration of the vocal tract. The alterations of the vocal tract configuration are considered an important element of the musical interpretation. Nevertheless, there is not a clear and objective perception among flutists of how the vocal tract works to influence the sound of the flute. This is due to the considerable number of variables that are involved in this process, such as the angle and the pressure of the air jet on the instrument, the movements of the jaw, among others. In order to achieve the proposed objective, we designed an experiment whose main goal was to demonstrate the existence of vocal tract influence on the timbre of the flute. For this purpose we built an artificial blower that enables the elimination of the influence caused by modifications in the shape and position of lips and jaw. The results were recorded and analyzed in comparison with the measurement of the impedance of the prototypes of vocal tract that were built to the experiment. Moreover, we also conducted interviews with professional flutists and professors with extensive experience on the field, to aggregate elements to the final analysis. In conclusion, we were able to assert that there are compelling evidences that the different configurations of the vocal tract are able to modify the sound of the flute.
43
Tameem, Hussain Z. "Solid modeling and geometric parameterization of the human vocal tract using magnetic resonance imaging and acoustic pharyngometer." Ohio : Ohio University, 2003. http://www.ohiolink.edu/etd/view.cgi?ohiou1071064899.
Full text
44
Fleischer, Mario, Alexander Mainka, Steffen Kürbis, and Peter Birkholz. "How to precisely measure the volume velocity transfer function of physical vocal tract models by external excitation." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-234483.
Full textAbstract:
Recently, 3D printing has been increasingly used to create physical models of the vocal tract with geometries obtained from magnetic resonance imaging. These printed models allow measuring the vocal tract transfer function, which is not reliably possible in vivo for the vocal tract of living humans. The transfer functions enable the detailed examination of the acoustic effects of specific articulatory strategies in speaking and singing, and the validation of acoustic plane-wave models for realistic vocal tract geometries in articulatory speech synthesis. To measure the acoustic transfer function of 3D-printed models, two techniques have been described: (1) excitation of the models with a broadband sound source at the glottis and measurement of the sound pressure radiated from the lips, and (2) excitation of the models with an external source in front of the lips and measurement of the sound pressure inside the models at the glottal end. The former method is more frequently used and more intuitive due to its similarity to speech production. However, the latter method avoids the intricate problem of constructing a suitable broadband glottal source and is therefore more effective. It has been shown to yield a transfer function similar, but not exactly equal to the volume velocity transfer function between the glottis and the lips, which is usually used to characterize vocal tract acoustics. Here, we revisit this method and show both, theoretically and experimentally, how it can be extended to yield the precise volume velocity transfer function of the vocal tract.
45
Petersson, Christer. "Preschool children day-care, diseases and drugs : studies of risk factors for respiratory tract infections /." Lund : Dept. of Community Health Sciences, Lund University, 1994. http://books.google.com/books?id=Vs9sAAAAMAAJ.
Full text
46
Montoya, Vincent Keith. "Metagenomic analyses of two female genital tract diseases : bacterial vaginosis and ovarian cancer." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44333.
Full textAbstract:
Metagenomics is a rapidly evolving field that has facilitated the expansion of microbiology into new areas of human and environmental health. Metagenomic studies have expanded the phylogenetic tree of life by increasing taxonomic resolution in individual phyla as well as adding entirely new branches of life. This revolution in microbiology has been made possible by the introduction of second-generation high-throughput sequencing, the associated methods for preparing DNA sequencing libraries, as well as new bioinformatic algorithms for analyzing these new types of data. Because of the novelty of these methods, very few have been systematically tested for their sensitivities and specificities outside of the initial development process. As the interpretation of metagenomic studies utilizing these tools depends greatly upon their efficiencies in both detection and classification, it is essential to best determine the performance of each tool. In this study, a variety of novel techniques were utilized and tested in their abilities to characterize the microbial populations in two regions of the female genital tract: ovarian cancer tissue and the vaginal microbiome. Although a diverse microbial population was initially observed in the transcriptome sequence data for ovarian cancer using next generation sequencing, we were unable to recover these microbial sequences through PCR and Sanger sequencing approaches. Optimized methods were applied to healthy vaginal microbiome samples and tested for their ability to differentiate them from a polymicrobial disease of the vagina, bacterial vaginosis. In addition to a high correlation between a microbial scoring system for bacterial vaginosis, this novel metagenomic pipeline also revealed microorganisms not yet associated with the vaginal microbiome such as specific Bifidobacteria spp., various bacteriophage, and Debaryomyces. Collectively, both of these studies provide unique insights into each disease as well as illustrate both the limitations and potential of the rapidly growing field of metagenomics.
47
Enright, Mark Charles. "Molecular characterization of Moraxella catarrhalis." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=158242.
Full textAbstract:
Moraxella catarrhalis is a gram-negative diplococcus which until recently was thought to be a harmless commensal. Increasing awareness has established the pathogenic nature of this organism and it is now recognised as a major cause of otitis media in children, exacerbations of chronic bronchitis in elderly patients and an occasional cause of invasive disease. M. catarrhalis is spread nosocomially especially in respiratory wards containing elderly patients. This study evaluated four methods for typing nosocomially spread isolates:- immunoblotting with normal human serum (NHS), and three DNA fingerprinting methods. The most discriminatory method found was restriction endonuclease analysis (REA) using Taq I, although immunoblotting with NHS and pulsed-field gel electrophoresis (PFGE) using Sma I sub-divided isolates grouped together by the other methods. PFGE using Not I only confirmed groupings made by other methods. A study of M. catarrhalis and phenotypically similar organisms was performed using comparisons of partial 16S rDNA sequence. 16S rDNA of M. catarrhalis strains from disparate geographical locations was found to be extremely conserved M. catarrhalis 16S rDNA was very similar to that of other Moraxella species whilst Moraxella species were found to be generally distinct from the Neisseria and Kingella species studied. These results confirm M. catarrhalis as a genuine member of the Moraxellae.
48
Revitt, David. "Characterization of a haemolysin from Serpulina hyodysenteriae." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333432.
Full text
49
Carstens, Ann. "Radiological tracheal dimensions of the normal Thoroughbred horse." Diss., University of Pretoria, 2008. http://hdl.handle.net/2263/30220.
Full textAbstract:
Respiratory conditions causing poor performance in horses are usually as result of upper respiratory tract diseases or are of pulmonary origin. The tracheal is rarely a cause of primary respiratory problems in the horse, but tracheal dimensions, particularly height, may be useful in evaluating upper repiratory tract conditions cranial to the trachea and lung pathology, due to resultant change in differential pressures between these areas. The normal radiological equine tracheal height along its length has as yet not been reported. Standing lateral radiographs of the cervical and thoracic trachea of 15 clinically normal sedated Thoroughbred horses, 3-6 years old, were made at peak inspiration and end expiration. Maximum height of the larynx, and trachea at the level of the third and fifth cervical vertebra, at the level of the first thoracic vertebra, carina and the left and right primary bronchi were measured. Ratios of laryngeal height relative to the third cervical vertebral body length and tracheal heights relative to the vertebral body lengths of adjacent third and fifth cervical vertebrae and first thoracic vertebra, and carina heights relative to a mid-thoracic vertebra, respectively were made, as well as tracheal height at the fist thoracic vertebra ratio with the thoracic inlet height. Known size metallic markers were used to determine magnification corrected tracheal heights in the sagittal plane and effect of body mass and height at the withers on tracheal height was determined. The magnification corrected radiological airway heights at end expiration and peak inspiration were measured and respectively the mean values were found to be: laryngeal height: 5.89 cm and 5.86 cm, tracheal height at the third cervical vertebra: 4.17 cm and 4.04 cm, tracheal height at the fifth cervical vertebra: 3.62 cm and 3.59 cm, tracheal height at the first thoracic vertebra: 3.4 cm and 3.23 cm and carina height: 3.85 cm and 4.12 cm. The ratios of these measurements to nearby vertebral body lengths were respectively: laryngeal height at the third cervical vertebra: 0.56 and 0.56, tracheal height at the third cervical vertebra: 0.4 and 0.39, tracheal height at the fifth cervical vertebra: 0.37 and 0.37, tracheal height at the first thoracic vertebra: 0.59 and 0.59, and carina height: 0.91 and 0.94. The ratio tracheal height at the first thoracic vertebra to the thoracic inlet respectively 0.15 and 0.15. Although there was no statistical difference in the data, there was a trend towards a higher tracheal height at expiration. No correlation was found between tracheal height and body mass or tracheal height and height at the withers, and measured tracheal height was generally lower than predicted tracheal height, possibly as result of sedation used. The small range of body mass and height in this study as well as the relatively small number of horses evaluated may account for the lack of correlation to predicted tracheal height. This study in normal horses may serve as a reference when radiologically evaluating cases of upper respiratory tract and lung pathology, where the tracheal dimensions may differ significantly due to differences in airway resistance and biomechanics. Radiographs to evaluate tracheal height can be made independent of respiratory phase in sedated horses, and it is recommended that ratios of tracheal height to an adjacent vertebral body length are more reliable values to compare within and between horses. It is recommended to take tracheal height measured at the fifth cervical vertebra since this measurement showed a slightly smaller standard deviation than at other sites measured as well as a medium amount of clinical effect. If only thoracic radiographs are made, measurements of tracheal height at the thoracic inlet is the alternative (the standard cranioventral view), but it is recommended to include the distal aspect of the first rib if the thoracic inlet is to be measured.Dissertation (MMedVet)--University of Pretoria, 2008.
Companion Animal Clinical Studies
unrestricted
50
Degottex, Gilles. "Glottal source and vocal-tract separation : estimation of glottal parameters, voice transformation and synthesis using a glottal model." Paris 6, 2010. http://www.theses.fr/2010PA066399.
Full textAbstract:
Cette étude s'intéresse au problème de l'inversion d'un modèle de production de la voix étant donné un enregistrement audio de parole pour obtenir une représentation de le source sonore qui est générée au niveau de la glotte, la source glottique, ainsi qu'un représentation des résonances et anti-résonances créées par les cavités du conduit vocal. Cette séparation des éléments composants la voix donne la possibilité de manipuler indépendamment les caractéristiques de la source et le timbre des résonances. Nous supposons que la source glottique est un signal à phase mixte et que la réponse impulsionnelle du filtre du conduit vocal est un signal à minimum de phase. Puis, considérant ces propriétés, différentes méthodes sont proposées pour estimer les paramètres d'un modèle glottique qui minimisent la phase carrée moyenne du résiduel convolutif d'un spectre de parole observé et de son modèle. Une dernière méthode est décrite où un unique paramètre de forme est solution d'une forme quasi fermée du spectre observé. Ces méthodes sont évaluées et comparées avec des méthodes de l'état de l'art en utilisant des signaux synthétiques et electro-glotto-graphiques. Nous proposons également une procédure d'analyse/synthèse qui estime le filtre du conduit vocal en utilisant un spectre observé et sa source estimée. Des tests de préférences ont été menés et leurs résultats sont présentés dans cette étude pour comparer la procédure décrite et d'autres méthodes existantes.