Treatise (D.M.A.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 149-152). Available also in a digital version from Dissertation Abstracts.

Thesis--University of Maryland. / Technical Note BN-87. AFOSR-TN-56-594, AD-115 021. "Supported in part by U.S. Air Force under contract No. AF 18 (600)-573."

Treatise (D.M.A.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI Company.

Vehicle drivers are a group of workers that are exposed to noise and whole-body vibration (WBV) several hours a day. Some drivers may also be exposed to high mental loads – monitoring and manipulating physical controls while engaging problem solving activities often with strong short-term memory and spatial manipulation components. Present standards and regulations that govern health risk assessment do not take into consideration the complexities of these multiple exposure environments. The effect of one factor (for example, noise or WBV) may be different than the effect of two factors presented together. This thesis investigates whether the combination of noise and WBV affects the performance of cognitive tasks more than when the exposures are presented separately. A series of studies were designed to expose subjects to noise and WBV stimuli designed to simulate real life working conditions. Different combinations of subjective ratings, cognitive tests, and cortisol measurements were conducted both during and immediately after exposures, which ranged from 20 to 45 minutes. The studies have shown that a combination of noise and WBV do not degrade cognitive performance more than a single stimulus. However, WBV can degrade attention performance after exposure is turned off when drivers have been working under high mental load during exposure. The combined stimuli are also experienced as more annoying and work is more difficult in such conditions. The exposure times and task difficulty levels used in this thesis did not produce biological stress as measured by cortisol. Nevertheless, subjective ratings are sometimes seen as early indicators of other symptoms and with increased task difficulty and/or longer exposure times there may appear other measurable outcomes of the combined stimuli.

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A hanseníase é uma das causas mais comuns de neuropatia periférica não traumática no mundo. O estudo propõe um método eletrônico não invasivo de avaliação da sensibilidade em paciente com hanseníase, comparando-os aos monofilamentos Semmes-Weinstein (convencional). Foram avaliados 30 pacientes do Ambulatório de Dermatologia do HCFMRP-USP pelos métodos eletrônico e convencional, consecutivamente. Cada paciente foi avaliado nos pontos das mãos e dos pés preconizados pelo Ministério da Saúde para avaliação de sensibilidade. Cada ponto foi mensurado pelo estesiômetro eletrônico 5 vezes, e posteriormente calculada a média das 3 medidas mais próximas. Para avaliar a variabilidade entre essas medidas, calculou-se o coeficiente de correlação intraclasse (ICC) cujo resultado foi aproximadamente 1 em todos os pontos, demonstrando repetibilidade dos mesmos. Através do coeficiente Kappa observou-se concordância entre os métodos estudados quanto às categorias (sensibilidade alterada e não-alterada), havendo concordância em mais de 75% e 63% nos pontos das mãos e dos pés, respectivamente. A porcentagem da concordância entre os 2 métodos observada nos 7 pontos da mão direita foi em média (somatório do percentual de valores concordantes de cada ponto divididos pelo número de pontos) 77,14% dos casos. Na mão esquerda a média de concordância foi de 75,71%. Nos 10 pontos do pé direito a média de concordância na avaliação de sensibilidade alterada e não alterada foi de 74,33%. Dos casos discordantes houve predominância (90,91% em média) de detecção de alteração de sensibilidade pelo estesiômetro eletrônico sem que os monofilamentos as detectasse. Nos 10 pontos do pé esquerdo, a concordância na avaliação foi em média 63,66% . Dos casos discordantes houve predominância (84,25% em média) de detecção de alteração de sensibilidade pelo estesiômetro eletrônico sem que os monofilamentos as detectasse, afinal, para os mesmos casos eles registraram sensibilidade não-alterada, portanto, normal. Apesar da concordância entre os pacientes com sensibilidades alterada e não-alterada pelo método Kappa, ao tratar-se de valores absolutos, os métodos foram diferentes. Essas diferenças entre seus valores podem ser atribuídas às particularidades de cada método, tais como espessura da superfície de contato a ser avaliada e o tipo de variável envolvida. Não se pode afirmar qual dos métodos é mais eficaz na detecção da alteração de sensibilidade do paciente com hanseníase, porém acredita-se nos resultados obtidos pelo estesiômetro eletrônico devido à metodologia criteriosa utilizada na sua aplicação e por ser uma variável contínua. Assim, o estesiômetro eletrônico mostrou ser um método quantitativo e de fácil aplicação clínica, capaz de avaliar as alterações de sensibilidade nos pacientes com hanseníase tanto no diagnóstico quanto no seu seguimento. / Leprosy disease is one of the most common causes of non traumatic peripheral neuropathy in the world. This study proposes a non invasive measurement with an electronic method for the leprosy patients\' evaluation, comparing them to Semmes- Weinstein monofilaments (the conventional one). Thirty patients of dermatology outpatient clinic of HCFMRP-USP were evaluated by the electronic and conventional methods consecutively. Each patient was evaluated on their hands and feet points that were standardized by brazilian Ministry of Health for sensitivity evaluation. Each point was measured by the electronic esthesiometer 5 times and after that it was calculated the mean of the 3 nearest ones measures. To evaluate the variability between these measures it was calculated the intraclass correlation coefficient (ICC). The result was aproximately 1 in all points, what demonstrated repeatability of them. Through Kappa coefficient it was observed agreement between the studied methods according to their categories (alterated and non alterated sensitivity) and there was agreement in more than 75% and 63% on the hands and feet points respectively. The addition of the percentage agreement values in each point was divided by the numbers of points resulting the percentage mean. The mean of agreement between the 2 methods on the 7 points of the right hand was 77.14%. On the left hand the mean of agreement was 75.71%. On all 10 points of the right foot the mean agreement on the alterated and non alterated sensitivity evaluation was 74.33%. There was predominance of 90.91% at mean on the detection of alterated sensitivity by the electronic esthesiometer with no detection by the monofilaments on the disagreement cases. On the left foot the agreement on the evaluation was 63.66% at mean. On the disagreement cases there was predominance of 84.25% at mean of the detection of alterated sensitivity by the electronic esthesiometer with no detection by the monofilaments, finally, for the same cases the last one registred non alterated sensitivity, therefore, normal. Besides the agreement between the patients with alterated and non alterated sensitivity through Kappa method, when the absolute values were observed, the methods were different. These differences between their values could be because of each method characteristics, such as the contact area thickness and the kind of variable involved. It is not possible to state which method is more effective on the detection of the sensitivity alteration on leprosy patients. However the results obtained by the electronic estesiometer seems to be reliable because of the strict methology used on its application. Than, the electronic estesiometer showed to be a method with an easy application, capable to evaluate the sensitivity alterations on leprosy patients.

A hanseníase é uma das causas mais comuns de neuropatia periférica não traumática no mundo. O estudo propõe um método eletrônico não invasivo de avaliação da sensibilidade em paciente com hanseníase, comparando-os aos monofilamentos Semmes-Weinstein (convencional). Foram avaliados 30 pacientes do Ambulatório de Dermatologia do HCFMRP-USP pelos métodos eletrônico e convencional, consecutivamente. Cada paciente foi avaliado nos pontos das mãos e dos pés preconizados pelo Ministério da Saúde para avaliação de sensibilidade. Cada ponto foi mensurado pelo estesiômetro eletrônico 5 vezes, e posteriormente calculada a média das 3 medidas mais próximas. Para avaliar a variabilidade entre essas medidas, calculou-se o coeficiente de correlação intraclasse (ICC) cujo resultado foi aproximadamente 1 em todos os pontos, demonstrando repetibilidade dos mesmos. Através do coeficiente Kappa observou-se concordância entre os métodos estudados quanto às categorias (sensibilidade alterada e não-alterada), havendo concordância em mais de 75% e 63% nos pontos das mãos e dos pés, respectivamente. A porcentagem da concordância entre os 2 métodos observada nos 7 pontos da mão direita foi em média (somatório do percentual de valores concordantes de cada ponto divididos pelo número de pontos) 77,14% dos casos. Na mão esquerda a média de concordância foi de 75,71%. Nos 10 pontos do pé direito a média de concordância na avaliação de sensibilidade alterada e não alterada foi de 74,33%. Dos casos discordantes houve predominância (90,91% em média) de detecção de alteração de sensibilidade pelo estesiômetro eletrônico sem que os monofilamentos as detectasse. Nos 10 pontos do pé esquerdo, a concordância na avaliação foi em média 63,66% . Dos casos discordantes houve predominância (84,25% em média) de detecção de alteração de sensibilidade pelo estesiômetro eletrônico sem que os monofilamentos as detectasse, afinal, para os mesmos casos eles registraram sensibilidade não-alterada, portanto, normal. Apesar da concordância entre os pacientes com sensibilidades alterada e não-alterada pelo método Kappa, ao tratar-se de valores absolutos, os métodos foram diferentes. Essas diferenças entre seus valores podem ser atribuídas às particularidades de cada método, tais como espessura da superfície de contato a ser avaliada e o tipo de variável envolvida. Não se pode afirmar qual dos métodos é mais eficaz na detecção da alteração de sensibilidade do paciente com hanseníase, porém acredita-se nos resultados obtidos pelo estesiômetro eletrônico devido à metodologia criteriosa utilizada na sua aplicação e por ser uma variável contínua. Assim, o estesiômetro eletrônico mostrou ser um método quantitativo e de fácil aplicação clínica, capaz de avaliar as alterações de sensibilidade nos pacientes com hanseníase tanto no diagnóstico quanto no seu seguimento. / Leprosy disease is one of the most common causes of non traumatic peripheral neuropathy in the world. This study proposes a non invasive measurement with an electronic method for the leprosy patients\' evaluation, comparing them to Semmes- Weinstein monofilaments (the conventional one). Thirty patients of dermatology outpatient clinic of HCFMRP-USP were evaluated by the electronic and conventional methods consecutively. Each patient was evaluated on their hands and feet points that were standardized by brazilian Ministry of Health for sensitivity evaluation. Each point was measured by the electronic esthesiometer 5 times and after that it was calculated the mean of the 3 nearest ones measures. To evaluate the variability between these measures it was calculated the intraclass correlation coefficient (ICC). The result was aproximately 1 in all points, what demonstrated repeatability of them. Through Kappa coefficient it was observed agreement between the studied methods according to their categories (alterated and non alterated sensitivity) and there was agreement in more than 75% and 63% on the hands and feet points respectively. The addition of the percentage agreement values in each point was divided by the numbers of points resulting the percentage mean. The mean of agreement between the 2 methods on the 7 points of the right hand was 77.14%. On the left hand the mean of agreement was 75.71%. On all 10 points of the right foot the mean agreement on the alterated and non alterated sensitivity evaluation was 74.33%. There was predominance of 90.91% at mean on the detection of alterated sensitivity by the electronic esthesiometer with no detection by the monofilaments on the disagreement cases. On the left foot the agreement on the evaluation was 63.66% at mean. On the disagreement cases there was predominance of 84.25% at mean of the detection of alterated sensitivity by the electronic esthesiometer with no detection by the monofilaments, finally, for the same cases the last one registred non alterated sensitivity, therefore, normal. Besides the agreement between the patients with alterated and non alterated sensitivity through Kappa method, when the absolute values were observed, the methods were different. These differences between their values could be because of each method characteristics, such as the contact area thickness and the kind of variable involved. It is not possible to state which method is more effective on the detection of the sensitivity alteration on leprosy patients. However the results obtained by the electronic estesiometer seems to be reliable because of the strict methology used on its application. Than, the electronic estesiometer showed to be a method with an easy application, capable to evaluate the sensitivity alterations on leprosy patients.

La géométrie symplectique et la géométrie complexe sont intimement liées, en particulier par les techniques asymptotiquement holomorphes de Donaldson et Auroux d'une part et par les travaux d’Eliashberget et Cieliebak sur la pseudoconvexité d'autre part. Les travaux présentés dans cette thèse sont motivés par ces deux liens. On donne d’abord la caractérisation symplectique suivante des constantes de Seshadri. Dans une variété complexe, la constante de Seshadri d’une classe de Kähler entière en un point est la borne supérieure des capacités de boules standard admettant, pour une certaine forme de Kähler dans cette classe, un plongement holomorphe et iso-Kähler de codimension 0 centré en ce point. Ce critère était connu de Eckl en 2014 ; on en donne une preuve différente. La deuxième partie est motivée par la question suivante de Donaldson : <<Toute sphère lagrangienne d'une variété projective complexe est-elle un cycle évanescent d'une déformation complexe vers une variété à singularité conique ?>> D'une part, on présente toute sous-variété lagrangienne close d’une variété symplectique/kählérienne close dont les périodes relatives sont entières comme lieu des minima d’une exhaustion <<convexe>> définie sur le complémentaire d'une section hyperplane symplectique/complexe. Dans le cadre kählérien, <<convexe>> signifie strictement plurisousharmonique tandis que dans le cadre symplectique, cela signifie de Lyapounov pour un champ de Liouville. D'autre part, on montre que toute sphère lagrangienne d'un domaine de Stein qui est le lieu des minima d’une fonction <<convexe>> est un cycle évanescent d'une déformation complexe sur le disque vers un domaine à singularité conique. / Symplectic geometry and complex geometry are closely related, in particular by Donaldson and Auroux’s asymptotically holomorphic techniques and by Eliashberg and Cieliebak’s work on pseudoconvexity. The work presented in this thesis is motivated by these two connections. We first give the following symplectic characterisation of Seshadri constants. In a complex manifold, the Seshadri constant of an integral Kähler class at a point is the upper bound on the capacities of standard balls admitting, for some Kähler form in this class, a codimension 0 holomorphic and iso-Kähler embedding centered at this point. This criterion was known by Eckl in 2014; we give a different proof of it. The second part is motivated by Donaldon’s following question: ‘Is every Lagrangian sphere of a complex projective manifold a vanishing cycle of a complex deformation to a variety with a conical singularity?’ On the one hand, we present every closed Lagrangian submanifold of a closed symplectic/Kähler manifold whose relative periods are integers as the lowest level set of a ‘convex’ exhaustion defined on the complement of a symplectic/complex hyperplane section. In the Kähler setting ‘complex’ means strictly plurisubharmonic while in the symplectic setting it refers to the existence of a Liouville pseudogradient. On the other hand, we prove that any Lagrangian sphere of a Stein domain which is the lowest level-set of a ‘convex’ function is a vanishing cycle of some complex deformation over the disc to a variety with a conical singularity.

À toute variété de contact, on peut associer canoniquement une variété symplectique appelée sa symplectisation de sorte que la géométrie de contact peut se reformuler en termes de géométrie symplectique équivariante. Au sujet de cette construction fondamentale, une question basique restait ouverte : si deux variété de contact ont des symplectisations isomorphes sont-elles isomorphes ? On construit dans cette thèse des contre-exemples à cette question. Il existe en effet, en toute dimension impaire supérieure ou égale à 5, des variétés de contact non difféomorphes admettant pourtant des symplectisations isomorphes. On construit également, sur une même variété deux structures de contact non conjuguées par un difféomorphisme mais admettant des symplectisations isomorphes. Les démonstrations sont basées sur un phénomène bien connu en topologie différentielle (l'existence de h-cobordismes non triviaux, détectée par la torsion de Whitehead) ainsi que sur des résultats de flexibilité en géométrie symplectique dus à Cieliebak et Eliashberg. Un autre résultat de cette th?e affirme que ces variété de contact, bien que non isomorphes, le deviennent toutefois après un nombre suffisant de sommes connexes avec un produit de sphères. / To any contact manifold one can associate a symplectic manifold called its symplectisation in such a way that contact geometry can be reformulated in terms of equivariant symplectic geometry. Concerning this fundamental construction, a basic question remained open : if two contact manifolds have isomorphic symplectizations, are they isomorphic ? In this thesis, we construct counter-examples to this question. Indeed, in any odd dimension greater than or equal to 5, there exist non-diffeomorphic contact manifolds with isomorphic symplectisations. In addition, we construct two contact structures on a closed manifold that are not conjugate by a diffeomorphism though their symplectizations are isomorphic. The proofs are based on a well-known phenomenon in differential topology (the existence of non-trivial h-cobordisms, detected by Whitehead torsion) as well as flexibility results in symplectic geometry due to Cieliebak and Eliashberg. Another result from this thesis asserts that though these contact manifolds are not isomorphic, they become so after sufficiently many connect sum with a product of spheres.