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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The relationship between nasal turbinate structure and the ecological attributes of ungulates

Kietzmann, Michelle Ann January 2010 (has links)
The nasal turbinates of ungulates are complex bony scrolls within the nasal cavity. These intricate bony plates, covered by moist epithelium, provide a large surface area that facilitates a countercurrent exchange of both water and heat between turbinal lining and respired air. Given their functional importance, maxilloturbinate size and structural dimensions may vary among species of different body sizes, activity levels and from different habitats, and may also serve as a predictor of the ability of the species to cope with high temperatures or limiting water resources. This is the first study to measure nasal turbinate surface area in ungulates using high-resolution computed tomography (CT) scanning. Heads of eleven South African bovid species and one European bovid species were successfully scanned and surface area measurements made using stereological techniques. These species included Cape grysbok, springbuck, bushbuck, blesbok, impala, mountain reedbuck, fallow deer, kudu, nyala, gemsbok and blue wildebeest; and represent species of different body sizes, from a range of habitats and with different water dependencies and predator avoidance strategies. The total maxilloturbinate surface area increased with body size for all study species. The surface areas of the nasal turbinates varied rostrocaudally, with the highest surface area occurring approximately midway along the length of the maxilloturbinate bones. The Cape grysbok stood out as having a nasal turbinate surface area of 12.77 cm2/kg, which was lower than the observed trend, the reason for this not being clear from these data. Phylogenetic independent analyses showed that log body mass and water dependence had a significant effect on nasal turbinate surface area, with habitat, distributional range and anti-predator behaviour having no effect. Subsequent phylogenetic species comparisons showed that structural variations in nasal turbinate surface area were phylogeny based due to the close genetic relatedness of the study species, and not associated with any environmental factors. The environmentally linked results for water dependency need further investigation in future studies of larger sample sizes and a broader range of species. Changes in climatic conditions may impact on a species‟ activity patterns, with individuals being forced to make behavioural modifications rather than physiological or anatomical adjustments. However, there is no clear evidence to indicate large differences in nasal turbinate surface area in relation to water dependence. This subsequently rules out the use of nasal turbinate surface area as a predictor to which and how ungulate species will respond to increasing global temperatures.
2

Measurement of the Cross-Sectional Area of the Nasal Passages of Nine Species of Modern Odontoceti with Implications for Comparative Physiology and the Paleophysiology of the Dinosauria

Katz, Eric Paul 05 March 1999 (has links)
In search of evidence for or against the endothermic dinosaur hypothesis, a recent study by Ruben et al. (1996) revealed that endotherms tend to have larger nasal cross-sectional areas than ectotherms of the same mass. The reason offered for this observation was that larger nasal passages are needed to house the complex respiratory turbinates possessed by endotherms. Whales were excluded from the study on the grounds that they have no nasal turbinates. In the present study, the cross-sectional area of the nasal passages of nine species of Odontoceti were measured by the use of latex casts. The regression of log cross-sectional area vs. log mass yielded the same line for the whales of the current study as for the endotherms of the previous study. Alternative explanations for the large nasal cross-sectional area of endotherms are sought.
3

Incidental sinonasal findings in cone-beam computed tomography imaging of the temporomandibular joints prevalence and clinical significance /

Guedes, Inês Helena. January 2010 (has links)
Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Medical Sciences, Temporomandibular Disorders/Orofacial Pain. Title from pdf file main screen (viewed on April 23, 2010). Includes bibliographical references.
4

Exploratory work on the effects of rapid maxillary expansion on nasal airway dimensions

Gordon, Jillian Madeline. January 2010 (has links)
Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Medical Sciences - Orthodontics. Title from pdf file main screen (viewed on November 29, 2009). Includes bibliographical references.
5

Numerical modeling of nasal cavities and air flow simulation

Wang, Kezhou, Denney, Thomas Stewart, January 2006 (has links) (PDF)
Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.120-127).
6

Incidental sinonasal findings in cone-beam computed tomography imaging of the temporomandibular joints: prevalence and clinical significance

Guedes, Ines Unknown Date
No description available.
7

Use of conventional tomography to evaluate changes in the nasal cavity with rapid palatal expansion

Palaisa, Jacqueline, January 2005 (has links)
Thesis (M.S.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains vii, 57 p. Vita. Includes abstract. Includes bibliographical references (p. 46-52).
8

Mannheimiose pneumônica experimentalmente induzida em bezerros pela Mannheimia (Pasteurella) haemolytica A1-cepa D153 : achados do exame físico, hemograma e swabs nasal e nasofaringeano /

Coutinho, Adriana de Souza. January 2004 (has links)
Orientador: Roberto Calderon Gonçalves / Resumo: A Mannheimia haemolytica A1 é o agente etiológico da Mannheimiose Pneumônica Bovina (MPB), uma doença de grande importância econômica. Um modelo experimental de MPB foi utilizado com o objetivo de avaliar os sinais clínicos, as alterações hematológicas e as espécies bacterianas das cavidades nasais e nasofaringeanas de bezerros com MPB, em diferentes momentos do curso da doença. Um total de 28 bezerros foi divido em sete lotes e os bezerros de cada lote foram distribuídos aleatoriamente em cada um dos quatro grupos. Cada grupo foi avaliado em um momento do curso da MPB: grupo I às 12, grupo II às 24, grupo III às 48 e grupo IV às 72 horas após a inoculação. Após incubação por cinco horas, a 37ºC e sob rotação de 150 ciclos/min, os inóculos da cepa D153 de M. haemolytica A1, com concentrações variando entre 1,5 x 10 8 a 8,20 x 10 9 UFCs (Unidades Formadoras de Colônias), foram infundidos na região da carina em todos os bezerros de cada lote, por via transtraqueal, enquanto eram mantidos em decúbito lateral direito. As respostas dos bezerros de cada grupo, I a IV, à M. haemolytica A1 foram caracterizadas por: hipertermia e taquicardia, com a temperatura corporal e a freqüência cardíaca tendendo a ser mais baixa nos grupos I a III e alcançando valores mais elevados no grupo IV. A freqüência respiratória aumentou em todos os grupos após a inoculação, com os valores dos grupos III e IV tendendo a ser mais elevados. Os sinais clínicos qualitativos da MPB que indicaram alterações da condição física geral, do sistema cardiovascular e alterações oculares tenderam a melhorar à medida que a doença progrediu, quando os quatro grupos foram comparados. Adicionalmente, a freqüência da secreção nasal mucosa e a intensidade da secreção nasal muco-purulenta tenderam a aumentar, concomitantemente com o aumento da... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: Mannheimia haemolytica A1 is the etiologic agent of Bovine Pneumonic Mannheimiosis (BPM), a disease of great economic importance. An experimental model of BPM was utilized with the objective of evaluating the clinical signs, hematologic changes and the bacterial species of the nasal and nasopharynx cavities of calves with BPM at different moments of the course of the disease. A total of 28 calves were divided in seven blocks, and the calves of each block were randomized to take part in one of four groups. Each group was evaluated at one moment of the course of BPM: group I at 12, II at 24, III at 48 and IV at 72 hours after inoculation. After incubation for 5 hours at 37ºC and under rotation of 150 cycles/min, the inoculums of the D153 strain of M. haemolytica A1, with concentrations varying between 1,5 x 10 8 a 8,20 x 10 9 CFU (Colonies Forming Unit), were infused at the karin region in all calves of each block, through transtraqueal route, while the calves were in right side lying. The reaction of the calves of each group (I to IV) to M. haemolytica A1 was characterized by: hipertermia and tachycardia, with body temperature and heart rate tending to be lower in groups I to III and reaching higher values in group IV. Respiratory rate increased in all groups after inoculation, with the values of groups III and IV tending to be higher. BPM qualitative clinical signs which indicated alterations of general physical condition, alterations of the cardiovascular system and ocular changes tended to improve along the progression of the disease when the four groups were compared. Additionally, the frequency of the mucous nasal... (Complete abstract, click electronic address below). / Doutor
9

La ventilation nasale du nouveau-né : études cliniques d'anomalies congénitales, modélisations numériques de l'écoulement et du réchauffement de l'air / Neonatal nasal breathing : clinical studies of congenital abnormalities, numerical modeling of airflow and air-conditioning

Moreddu, Éric 07 December 2018 (has links)
La ventilation nasale est vitale pour le nouveau-né, respirateur nasal exclusif. Le tiers antérieur des fosses nasales peut être modifié par une sténose congénitale de l’orifice piriforme, tandis leur partie postérieure peut être fermée par une atrésie choanale uni ou bilatérale ou par des lésions du nasopharynx.Les simulations numériques permettent d’analyser l’écoulement et le conditionnement de l’air en contournant les limites techniques et éthiques rencontrées in vivo. Devant la rareté des données dans la littérature, une étude de faisabilité a été nécessaire et concluante : les modèles numériques sont qualitativement proches de la réalité. Un travail sur les conditions physiologiques chez le nouveau-né a ensuite été réalisé, avec une méthodologie retravaillée. La reconstruction tridimensionnelle des fosses nasales est possible dès la naissance. La création d’une sphère centrée sur la pointe du nez, éloignant le domaine d’entrée de la zone d’intérêt, a permis d’analyser le rôle du tiers antérieur des fosses nasales.La valve nasale joue un rôle majeur en inspiration : perte de charge, accélération, guidage des flux et réchauffement de l’air. Les trois quarts du réchauffement ont lieu en amont du cornet inférieur. Une obstruction nasale entraîne une réduction des vitesses et une augmentation des températures de l'air. La simulation de l’inspiration d’air à 0°C a permis de constater que les fosses nasales permettent d’amortir les effets du refroidissement de l’air extérieur.Ce travail constitue une première approche de la physiologie de la ventilation nasale du nouveau-né par modélisation numérique, indispensable à la compréhension de la pathologie nasale néonatale. / Nasal breathing is essential for the newborn, exclusive nasal breather. The anterior third of the nasal fossae may be modified by a congenital stenosis of the pyriform aperture, while their posterior part may be closed by unilateral or bilateral choanal atresia.Numerical simulations are a good means to analyze airflow and air-conditioning: they circumvent the technical and ethical limits encountered in vivo. Given the rarity of available data in the literature, a feasibility study was necessary and was conclusive: numerical models are qualitatively close to reality. A work on the physiological conditions in newborns was conducted, using refined methodology. The three-dimensional reconstruction of the nasal fossae is possible from birth. The creation of a sphere centered on the tip of the nose, moving the boundary conditions away from the area of interest, made it possible to analyze the role of the anterior third od the nasal fossae.The nasal valve plays a major in inspiration: it is a zone of pressure loss, acceleration, flow guidance and air warming. Three-fourths of the warming takes place upstream the inferior turbinate. A partial nasal obstruction modifies these results with lower velocities and higher temperature of the air. The simulation of the inspiration of cold air (0°C) has shown that the nasal fossae can dampen, without canceling, the effects of air cooling. This work is a first approach to the physiology of nasal ventilation of the newborn by numerical modeling, which is essential to the understanding of neonatal nasal pathology.

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