The objective of this research is to analyze the relationship between environ-mental heat exchange and vascular response in the pallid bat wing during systemicheating and to develop a simplied model of heat transfer for theoretical analysis.During heating experiments, metabolic activity, body temperature and alterations invessel diameter and blood ow were monitored. This research is very signicant, asit will correlate thermoregulation and vascular response in a way that has not beenstudied before.The wing of the pallid bat is selected because the microvascular bed performssimilar functions as that of the human skin in terms of thermoregulation; understand-ing vascular response to heat or cold allows to analyze vascular function, or arterialhealth, a response that is altered at early stages of several diseases in humans. Athigh body temperatures, bats can dissipate heat through their wings; the bat wingserves as a thermal window where heat exchange is determined by local blood owand vascular response in the wing.For this study, a lumped mathematical model to calculate body and skin tem-perature alterations in response to changes in environmental conditions has beendeveloped. In order to formulate this model, experiments have been proposed wherethe pallid bat is subjected to dynamic systemic heating with and without the wingextended. By having the wing extended outside a metabolic chamber during heating,the bats were able to maintain an equilibrated body temperature; having the wing enclosed caused body temperature to increase rapidly. The experiments were designedto obtain correlations between systemic and vascular responses and therefore learnabout the thermoregulatory mechanisms of the pallid bat.Results from experiments following Animal Use Protocols 2006-253 and 2007-110indicate that vascular responses to environmental temperature changes (changes inTchamber) maintain or reduce body temperature to basal conditions. Vessel diameter,centerline velocity, blood ow and heat ux increase with Tchamber therefore deliveringa greater volume of blood to the bat wing and increasing heat exchange with theenvironment. The positive responses in the wing to Tchamber signify that the pallidbat is regulating its body temperature as had been expected.

The objective of this research is to analyze the relationship between environ-mental heat exchange and vascular response in the pallid bat wing during systemicheating and to develop a simplied model of heat transfer for theoretical analysis.During heating experiments, metabolic activity, body temperature and alterations invessel diameter and blood ow were monitored. This research is very signicant, asit will correlate thermoregulation and vascular response in a way that has not beenstudied before.The wing of the pallid bat is selected because the microvascular bed performssimilar functions as that of the human skin in terms of thermoregulation; understand-ing vascular response to heat or cold allows to analyze vascular function, or arterialhealth, a response that is altered at early stages of several diseases in humans. Athigh body temperatures, bats can dissipate heat through their wings; the bat wingserves as a thermal window where heat exchange is determined by local blood owand vascular response in the wing.For this study, a lumped mathematical model to calculate body and skin tem-perature alterations in response to changes in environmental conditions has beendeveloped. In order to formulate this model, experiments have been proposed wherethe pallid bat is subjected to dynamic systemic heating with and without the wingextended. By having the wing extended outside a metabolic chamber during heating,the bats were able to maintain an equilibrated body temperature; having the wing enclosed caused body temperature to increase rapidly. The experiments were designedto obtain correlations between systemic and vascular responses and therefore learnabout the thermoregulatory mechanisms of the pallid bat.Results from experiments following Animal Use Protocols 2006-253 and 2007-110indicate that vascular responses to environmental temperature changes (changes inTchamber) maintain or reduce body temperature to basal conditions. Vessel diameter,centerline velocity, blood ow and heat ux increase with Tchamber therefore deliveringa greater volume of blood to the bat wing and increasing heat exchange with theenvironment. The positive responses in the wing to Tchamber signify that the pallidbat is regulating its body temperature as had been expected.

Thesis (Ph. D.)--University of Virginia, 2008. / Title from title page. Includes bibliographical references. Also available online through Digital Dissertations.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-02-14T11:54:11Z No. of bitstreams: 1 arquivo total.pdf: 1993500 bytes, checksum: afc116c8137450f5a4f1743f6804afd0 (MD5) / Made available in DSpace on 2017-02-14T11:54:11Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 1993500 bytes, checksum: afc116c8137450f5a4f1743f6804afd0 (MD5) Previous issue date: 2015-04-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The fruit of S. cumini is considered source of phenolic compounds with beneficial effects important for health, especially for its antioxidant potential. This work aimed to investigate the effects of the fruit skin hydro-alcoholic extract of S. cumini (EHAPS) compared to the changes related to the consumption of high calorie diet in rats. The total phenolic content and total antioxidant capacity were evaluated for standardization of the extract. The animals were treated orally, with EHAPS, for 6 weeks, in two doses (100 and 300 mg / kg) and the control of normocaloric diets (NCT) and hypercaloric (HCT) received saline. Was monitored weight, food and water consumption and blood pressure during the treatment At the end, murinométricas measures were taken, collected up the plasma and some organs for analysis. The EHAPS showed high antioxidant capacity, with a total phenolic content of 5440.86 mg GAE / 100g and EC50 value of 59 mg / mL. At the end of the six weeks of treatment HCT group had the highest percentage of weight gain relative to the NCT, 26 ± 3.9 and 15.3 ± 1.7 respectively. The hypercaloric diet also increased calorie intake, waist circumference, the adiposity index and blood glucose levels. In addition to damage the vascular response to drugs such as phenylephrine, acetylcholine, sodium nitroprusside, and raise levels of oxidative stress. The treatment decreased the percentage weight gain of the group HCT of 19.7 ± 2.6 to 13.3 ± 1.1 and 12.5 ± 1.5 in groups H100 and H300, respectively, from the 4th week of treatment. The treatment with EHAPS showed improvements in vascular response and reduction of oxidative stress in the treated animals. There has been no significant change in blood pressure levels between the groups and no significant reduction in visceral adiposity index and blood glucose in animals after treatment. The results suggest that phenolic compounds present in the fruit skin S. cumini reduce the deleterious effects of a hypercaloric diet, preventing weight gain and improving the total antioxidant capacity and the vascular response in animal models. / O fruto da S. cumini é considerado fonte de compostos fenólicos apresentando efeitos benéficos importantes para a saúde, com destaque para seu potencial antioxidante. Dessa forma, objetivou-se investigar os efeitos de um extrato hidroalcoólico da pele do fruto de S. cumini (EHAPS) mediante às alterações relacionadas ao consumo de dieta hipercalórica em ratos. O teor de fenólicos totais e capacidade antioxidante total foram avaliados para padronização do extrato. Os animais foram tratados por via oral, com o EHAPS, durante 6 semanas, em duas doses (100 e 300 mg/Kg) e o controle das dietas normocalórica (NCT) e hipercalórica (HCT) receberam solução salina. Foi monitorado o peso, o consumo alimentar e hídrico e a pressão arterial ao longo do tratamento. Ao final foram tomadas medidas murinométricas, coletou-se o plasma e alguns órgão para análises. O EHAPS apresentou elevada capacidade antioxidante, com um teor de fenólicos totais de 5.440,86 mg EAG/ 100g de amostra e valor de CE50 de 59 μg/mL. Ao final das seis semanas de tratamento o grupo HCT apresentou um ganho percentual de peso mais elevado em relação ao NCT, 26 ± 3,9 e 15,3 ± 1,7, respectivamente. A dieta hipercalórica também aumentou o consumo de calorias, a circunferência abdominal, o índice de adiposidade e os níveis glicêmicos, além de prejudicar a resposta vascular às drogas como fenilefrina, acetilcolina, nitroprussiato de sódio, e elevar os níveis de estresse oxidativo. O tratamento foi capaz de diminuir o ganho de peso percentual do grupo HCT de 19,7 ± 2,6 para 13,3 ± 1,1 e 12,5 ± 1,5 nos grupos H100 e H300, respectivamente, a partir da 4° semana de tratamento. Ao final do tratamento observou-se melhora da resposta vascular e diminuição do estresse oxidativo nos animais tratados. Não foi observada nenhuma alteração significativa dos níveis de pressão arterial entre os grupos e não houve redução significativa do índice de adiposidade visceral e glicemia sanguínea nos animais após o tratamento. Os resultados sugerem que os compostos fenólicos presentes na pele do fruto de S. cumini diminuem os efeitos deletérios de dietas hipercalóricas, prevenindo o ganho de peso corporal e melhorando a capacidade antioxidante total e a resposta vascular em modelos animais.