Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Springfield College, 2003. / Includes bibliographical references.

Thesis (M.S.)--Villanova University, 2006. / Chemistry Dept. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:32:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-13Bitstream added on 2014-06-13T18:44:37Z : No. of bitstreams: 1 munhoz_e_dr_arafo.pdf: 3085541 bytes, checksum: f014aca5c4e34e1bd024219270c2acaf (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O estresse, atualmente, é considerado um fator importante na fisiopatologia de muitos distúrbios psiquiátricos. Embora os efeitos do estresse agudo possam ser contrabalanceados por respostas adaptativas, o estresse intenso, repetido ou prolongado pode eliciar alterações neuronais duradouras que constituirão as bases de doenças psiquiátricas, como a depressão. Levantamentos epidemiológicos também mostram elevada prevalência de tabagistas entre pacientes com depressão maior. Estas altas taxas de comorbidade sugerem uma provável relação causal: pacientes com depressão proeminente procurariam a nicotina para alívio dos sintomas. Assim, este trabalho investigou as alterações neuroquímicas e neuroendócrinas mediadas pela nicotina na resposta de adaptação ao estresse, utilizando-se, para tanto, o teste modificado da natação forçada (TNF). Para tanto, ratos Wistar machos foram submetidos ao TNF (30 cm de água, 24 ± 1ºC) por 15 min e tratados (1, 19 e 23h) com nicotina (NIC: 0,5 mg/kg, sc), imipramina (IMI: 15 mg/kg, ip) ou salina (SAL). Uma hora após a última injeção, os animais foram reexpostos (5 min) à mesma cuba. Imediatamente após o teste, os animais foram sacrificados; o hipocampo dorsal (HD) e ventral (HV), hipotálamo (HT) e os núcleos dorsal (DR) e mediano (MR) da rafe foram coletados por punch para quantificação de 5-HT, 5-HIAA e NA por HPLC e o sangue, para quantificação da corticosterona plasmática por radioimunoensaio. O hipocampo total também foi utilizado para avaliar a expressão do receptor serotoninérgico 5-HT1A e do glicorreceptor (GR) por western blot. Ainda, avaliou-se o efeito da prazosina nas alterações neuroquímicas induzidas pelo TNF. O tratamento subcrônico com NIC e IMI reduziu em 39% e 50%, respectivamente, o parâmetro de imobilidade e aumentou em 52% e 66%, respectivamente, as contagens de escalada, em relação ao grupo... / Stress is considered a key component in the pathophysiology of several psychiatric diseases. Although the effects of acute stress can be counterbalanced by adaptative responses, intense, repeated or prolonged stress can elicit long lasting neuronal alterations that are related to the occurrence of psychiatric disorders, such as depression. Epidemiological studies have also identified a high prevalence of smokers among depressive patients. These observations suggest a causal relationship: smoking is a self-medication effort to alleviate some symptoms of depression by nicotine. Then, this study investigated nicotine mediatedneurochemical and neuroendocrine alterations in the adaptation response to stress. The modified forced swmming test (FST), a protocol originally employed for screnning new antidepressant drugs, was employed. Male Wistar rats were placed individually into a container (30-cm of water, 24±1ºC, 15 min - pretest). Then animals received nicotine (0.5 mg/kg, s.c.), imipramine (15 mg/kg, i.p.) or saline injections at 1, 19 and 23h after the pretest. One hour after the injections, animals were placed in the same container for 5 min. Immediately after, the animals were sacrificed; dorsal (DH) and ventral (VH) hippocampus, hypothalamus (HT) and dorsal (DR) and median (MR) raphe nuclei were collected by punch for measurement of 5-HT, 5-HIAA and NA by HPLC (expressed in ng/mg tissue). Blood samples were collected for determination of plasma corticosterone levels by radioimmunoassay. The whole hippocampus was also used to evaluate the expression of the 5-HT1A serotoninergic receptor and glucocorticoid receptor by western blot. The effects of prazosin in TNF induced-neurochemical alterations was also evaluated. Nicotine and imipramine decreased in 39% and 50%, respectively, the immobility behavior and increased in 52% and 66%, respectively, the climbing scores, in relation to saline... (Complete abstract click electronic access below)

A device, utilising the suction produced by a disposable syringe, was developed to restrain a range of very small organisms in flowing seawater. The technique was developed during an investigation of the swimming response of barnacle nauplii to changes in temperature. The combination of beat frequency and the proportion of time spent active was held constant for B. balanoides and B. hameri but steadily increased with temperature for C. montagui and B. amnhitrite. E. modestus showed an intermediate response. Methods for utilising video-tape recordings and a micro-impedance pneumograph for analysing limb beat activity, were developed during an investigation of the feeding behaviour of nauplii. The feeding mechanism was reappraised and an increase in the volume of water handled by the larvae noted in the presence of food organisms. This increase was shown by E. modestus nauplii in response to dissolved organic substances, indicating that the nauplii could determine when to feed, and what was edible, from the shell of dissolved material surrounding food particles. A quantitative study of the grazing of E. modestus nauplii showed that the ingestion rate of algal cells increased up to concentrations of 150 - 200 cells/ul, then remained steady. Larger algal cells were taken from algal mixtures, in preference to smaller ones. Restraint techniques and video-recordings of free-swimming cypris larvae showed them to be prodigeous swimmers, with considerable control over the direction and magnitude of the thrust produced. The close observation of larvae allowed by the restraint technique enabled mechanical stimulation of particular sense organs. The function of these organs had been interpreted from their structure by previous authors. In some instances, a mechano-receptive function was confirmed, but in others, doubt was cast. Restrained cyprids responded to complex sound fields by swimming less often. A dual mode sound chamber was used to differentiate between sound pressure and displacement, but negative results were obtained. The cyprids did, however, respond to substrate vibrations, at low frequencies, by swimming off the substrate. All the developed techniques were further employed to show that the classical copepod feeding swirls were artefacts. Temora produced'only a posteriorly flowing current for feeding and swimming, when restrained in larger volumes of seawater. The amount of water handled by Temora was also shown to increase when food algae were present.

Aquatic propulsion by means of undulatory movements of the median (dorsal and anal) fins is the primary mode of transport for the Picasso triggerfish (Rhinecanthus aculeatus). Known as balistiform locomotion, this form of propulsion is an adaptation for highly efficient movement within complex environments such as coral reefs. A principle component of balistiform locomotion has been the development of momentum enhancement, a fin-force multiplier that increases swimming efficiency. This study examines the kinematics and energetics of balistiform locomotion employing theoretical models of thrust, power, and efficiency. Thrust and power were calculated and compared with theoretical values modeled by Lighthill and Blake (1990). This model has heretofore not been thoroughly vetted and was tested for accuracy and applicability. Thrust force was estimated from resistance (drag) using a vertical dead drop to determine terminal velocity; power was calculated from oxygen consumption measurements at different speeds. The Lighthill and Blake (1990) model requires median fin kinematics (frequency, wavelength, amplitude, wave angle), which were measured from high-speed videography and followed statistically predicted trends with frequency being the dominant variable, and the others changing little or not at all with speed. Momentum enhancement was found to be 3.6, close to Lighthill and Blake’s (1990) theoretically predicted value of 2.5. Momentum enhancement is experimentally proven here for the first time. Theoretical and empirical thrust force values are closely matched; theoretical thrust is greater at lower speeds and lower at higher speeds. The ratio of theoretical thrust to drag-estimated thrust averages 1.08. Theoretical values for power are greater than those measured by a factor of about 3.6 and cannot be explained by measurement error. / Science, Faculty of / Zoology, Department of / Graduate

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Ten male adolescent and young adult swimmers were examined to determine the effects of two breathing patterns on selected physiological parameters during a simulated 200-yard freestyle swim. Specifically, a comparison of oxygen uptake, blood lactic acid, ventilation and the respiratory exchange ratio responses to a timed swim were made under two experimental breathing conditions. The intensity of the experimental trials was maintained at approximately 95% of the subjects' maximal workload to induce maximal effort. The validity of capillary blood samples for the use of micro-determination of blood lactic acid was established prior to the preliminary and experimental trials. Maximal physiological parameters for each subject were then obtained during the Preliminary Test using a maximal intermittent tethered swimming test. The experimental phase of the study consisted of four 110 sec swims designed to simulate competitive 200-yard freestyle swimming. Two swims were conducted under Condition 1, wherein the subject swam breathing once every arm cycle. The remaining two swims were under Condition 2, wherein the subject swam breathing every alternate arm cycle. Using Pearson product-moment correlation to determine within condition reliability for each dependent variable, it was found that oxygen uptake, blood lactic acid and ventilation were reliable. Under Condition 1, the respiratory exchange ratio was also found to be reliable, however, under Condition 2, the reliability coefficient was considered unacceptable. Therefore, the respiratory exchange ratio was excluded from further analyses. Hotelling's T² was employed on the linear combination of oxygen uptake, ventilation, and blood lactic acid between conditions. This analysis indicated a significant difference (p<.05) between conditions. Simultaneous confidence intervals indicated that oxygen uptake, blood lactic acid, and ventilation were the variables causing the difference. Simple linear and stepwise regression were employed to determine the extent to which the dependent variables contributed to the V̇O₂ (ml/kg·min⁻¹) in each experimental condition. Under Condition 1, the respiratory exchange ratio was found to be closely associated with the V̇O₂ in that condition. Under Condition 2, ventilation was found to be most closely associated with the lower V̇O₂ observed in this condition. It was deemed important to determine the extent to which changes between conditions in the dependent variables contributed to changes in the V̇O₂ (ml/kg·min⁻¹) between conditions. It was found that the changes in ventilation contributed only a small portion to the changes in V̇O₂ between conditions, which indicated that something other than the dependent variables was associated with the changes in V̇O₂ between conditions. During training and performance, the evidence suggests that under a given workload, greater metabolic capacity was required when breathing every stroke. In addition, higher intensities of work could be tolerated when breathing was done only during alternate strokes. / Ed. D.