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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.
41

Influência da manipulação neonatal sobre alterações metabólicas e neuroquímicas induzidas pela exposição crônica à dieta palatável na vida adulta

Benetti, Carla da Silva January 2010 (has links)
Estudos prévios demonstram que intervenções precoces levam a alterações comportamentais e neuroendócrinas na vida adulta. Nossos achados anteriores demonstram que animais manipulados no período neonatal consomem mais alimento palatável na vida adulta e apresentam um menor aumento do depósito de gordura abdominal, após exposição crônica a dieta palatável (chocolate) em relação aos animais intactos. Neste trabalho de tese, nosso objetivo foi avaliar os efeitos da manipulação neonatal sobre a preferência alimentar bem como sobre a regulação metabólica de ratas adultas. Para isso, investigamos parâmetros metabólicos e neuroquímicos em resposta à exposição crônica a uma dieta hipercalórica e palatável, assim como a um período de abstinência desse tipo de alimento em ratas fêmeas adultas expostas ou não à manipulação neonatal (10 min/dia, 10 primeiros dias de vida). A manipulação neonatal induziu maior ingestão de alimento palatável após um curto período de privação. Entretanto, o consumo durante a exposição crônica a essa dieta não diferiu entre os grupos experimentais. Também observamos que ratas fêmeas manipuladas, quando cronicamente expostas à dieta palatável na vida adulta, têm menor aumento da gordura abdominal e esse efeito persiste após a privação da dieta. Ratas não-manipuladas apresentaram níveis mais elevados de colinesterases no soro após exposição crônica a dieta palatável, entretanto, sem alterações na atividade de colinesterases no córtex cerebral. Foi identificado, após exposição crônica a dieta palatável, uma redução na atividade da enzima Na+,K+-ATPse no hipocampo e na amígdala e um aumento nos níveis plasmáticos de S100B em ratas não-manipuladas no período neonatal. Após as primeiras 24h de privação do alimento palatável, ratas fêmeas não-manipuladas demonstraram maior frequência de sinais de abstinência (tremores de cabeça) em comparação com ratas manipuladas no período neonatal. Assim, esses achados sugerem que a manipulação neonatal determina alterações persistentes no comportamento alimentar e previne algumas alterações periféricas e centrais induzidas pela exposição crônica a uma dieta hiperpalatável, modulando a resposta metabólica de modo a reduzir a vulnerabilidade de dano metabólico e neural. / Previous studies have demonstrated that an intervention early in life leads to behavior and neuroendocrine alterations in adulthood. According to our previous findings neonatallyhandled animals have an increased consumption of palatable food, as well as a lower increase in abdominal fat accumulation after being chronically exposed to a highly palatable diet (chocolate) as compared with intact rats. In the present study, our aim was to evaluate the effects of neonatal handling on food preference and metabolic regulation in adult female rats. Therefore, we investigated metabolic and neurochemical parameters in response to a chronic exposure to a highly palatable diet, and to its withdrawal in adult female rats exposed or not to neonatal handling procedure (10 min/day, 10 first days of life). We observed an effect of neonatal handling inducing an increased palatable food intake after one week of chocolate withdrawal. However, chocolate consumption during long-term exposure to this type of diet did not differ between experimental groups. After a 30-days-period of chocolate exposure, non-handled female rats exhibited an increased abdominal fat deposition in comparison to neonatally-handled rats, and this effect persisted even after chocolate withdrawal. Nonhandled rats had increased serum cholinesterase levels after chronic exposure to palatable diet, without alterations in cerebral cortex cholinesterase activity. We also observed that chocolate consumption lead to a reduced Na+,K+-ATPse activity in hippocampus and amygdala, as well as an increased plasma S100B levels in non-handled females rats. After the first 24h of chocolate withdrawal, non-handled female rats exhibited an increased frequency of head shakes, during the Open Field task, in comparison to handled rats. Therefore, these findings suggest that neonatal handling leads to persistent alterations in feeding behavior, and also prevents some peripheral and central alterations induced by chronic exposure to a highly palatable diet; modulating the metabolic response in order to reduce the vulnerability to metabolic and neuronal damage in adulthood.
42

The morphology, reproductive biology and habitat utilisation of the exotic invasive lizard, the brown anole (anolis sagrei), in Taiwan

Norval, Gerrut 12 1900 (has links)
Surveys and vegetation analyses were used to determine the known distribution and the characteristics of the habitat utilised by Anolis sagrei in Taiwan. Sampled lizards were used for morphological comparisons, and to investigate the reproductive biology of this species in Taiwan. The results of this study indicate that the distribution of A. sagrei in Taiwan is extensive (≥237 ha) in Chiayi City and County (southwestern study site) and scattered (≥8 ha) in Hualien City and County (eastern study site). These lizards were mostly found in open sunny degraded man-made habitats. Although some variations were noted in the comparisons between the A. sagrei collected from the two study sites, it was concluded that the two populations likely have the same founder population. The reproductive biology study indicated that photoperiod and the associated temperatures determine the reproductive cycles in A. sagrei. It also demonstrated that reproduction in this species is energetically demanding. / Nature Conservation / MSc.(Nature Conservation)
43

The morphology, reproductive biology and habitat utilisation of the exotic invasive lizard, the brown anole (anolis sagrei), in Taiwan

Norval, Gerrut 12 1900 (has links)
Surveys and vegetation analyses were used to determine the known distribution and the characteristics of the habitat utilised by Anolis sagrei in Taiwan. Sampled lizards were used for morphological comparisons, and to investigate the reproductive biology of this species in Taiwan. The results of this study indicate that the distribution of A. sagrei in Taiwan is extensive (≥237 ha) in Chiayi City and County (southwestern study site) and scattered (≥8 ha) in Hualien City and County (eastern study site). These lizards were mostly found in open sunny degraded man-made habitats. Although some variations were noted in the comparisons between the A. sagrei collected from the two study sites, it was concluded that the two populations likely have the same founder population. The reproductive biology study indicated that photoperiod and the associated temperatures determine the reproductive cycles in A. sagrei. It also demonstrated that reproduction in this species is energetically demanding. / Nature Conservation / MSc.(Nature Conservation)
44

Analiza odnosa mase i distribucije masnog tkiva sa varijabilnošću srčane frekvencije kod gojaznih osoba različitih metaboličkih profila / Analysis of relationship between mass and distribution of adipose tissue and heart rate variability in obese people of different metabolic profiles

Rastović Marina 22 September 2016 (has links)
<p>Izvod: UVOD: Metabolički zdrave gojazne osobe su okarakterisane odsustvom metaboličkog sindroma i/ili insulinske rezistencije i sistemske inflamacije. Mali je broj podataka o ulozi aktivnosti autonomnog nervnog sistema u razvoju kardiometaboličkih komplikacija kod gojaznih osoba, kao i o njegovoj vezi sa specifičnom distribucijom masnog tkiva. CILJ: Analiza varijabilnost srčane frekvencije (HRV) kod metabolički zdravih (MHO) i gojaznih osoba sa metaboličkim rizikom (MUO), analiza povezanosti HRV sa metaboličkim faktorima i distribucijom masnog tkiva, kao i analiza uzrasne dinamike HRV kod gojaznih osoba različitih kardiometaboličkih profila. MATERIJAL I METODE: Ukupno 125 gojaznih ispitanika oba pola podvrgnuto je antropometrijskim merenjima u cilju procene mase i distribucije masnog tkiva, izvr&scaron;ena je analiza telesne kompozicije, uzeti su uzorci krvi u cilju određivanja lipidskog i lipoproteinskog statusa, stanja glikoregulacije i nivoa inflamatornih markera, meren je krvni pritisak i procenjena je HRV tokom petominutne digitalne elektrokardiografije. Podaci su statistički obrađeni kori&scaron;ćenjem paketa SPSS 11.5. REZULTATI: HRV mere se nisu razlikovale statistički značajno među MHO i MUO mu&scaron;karcima. MHO žene su imale vi&scaron;e vrednosti RRNN, SDNN, RMSSD, pNN50, LF, HF i TP u odnosu na MUO žene, na čega metabolički profil utiče sa 6,6-11,2%(p˂0,01), predstavljeno kroz parcijalnu deljenu varijansu. Nakon antropometrijskih faktora uzetih u obzir, perzistirale su vi&scaron;e vrednosti HF kod MHO žena. Razlika u RRNN, pNN50 i TP između MHO i MUO premenopauzalnih žena (vi&scaron;e vrednosti za MHO, p˂0,05) se izgubila nakon kontrole za krvni pritisak. Insulinemija je uticala na pojave razlika u RRNN između MHO i MUO premenopauzalnih žena, parcijalna deljena varijansa 7,6%. SAD kod žena se negativno povezivao sa LF/HF i LFnorm, a pozitivno sa HFnorm, parcijalne deljene varijanse 8,4-11,9% (p˂0,05). Prednji nabor podlaktice kod žena se pozitivno povezivao sa LF i LF/HF, a negativno sa HFnorm (p˂0,01). Visceralna masna masa je predviđala značajno HRV mere mu&scaron;karaca, parcijalna deljena varijansa 13-34% (p˂0,01). U okviru gornjeg tercila HRV mera RMSSD, pNN50 i LF MUO osoba, HOMA indeks je statistički značajno niži (p˂0,05). Kod MUO osoba SDNN, RMSSD, lnpNN50, lnLF, lnHF i TP značajno su se smanjivali u uzrastu od 19-29 do 40-49 godina. Kod MHO osoba primetna je uzrasna promena HF mere u četvrtoj deceniji života. ZAKLJUČAK: MHO osobe ženskog pola imaju značajno vi&scaron;e vrednosti markera varijabilnosti srčane frekvencije u odnosu na MUO. Razlike u HRV merama su uslovljene kriterijumima metaboličke podele, predominantno insulinemijom, vrednostima krvnog pritiska i centralnom masnom masom. Kod žena centralna distribucija masnog tkiva korelira sa smanjenom srčanom simpatičkom aktivno&scaron;ću dok se periferna distribucija masnog tkiva povezuje obrnuto sa komponentama aktivnosti autonomnog nervnog sistema. Kod mu&scaron;karaca centralna masna masa, ali ne i periferna, je značajno povezana sa HRV. MUO osobe sa nižom HRV imaju veći stepen insulinske rezistencije, dok HRV ne utiče na insulinsku senzitivnost MHO osoba. Značajniji uzrasno zavisni pad HRV mera primetan je kod MUO osoba, pogađajući obe komponente autonomnog nervnog sistema za razliku od MHO osoba.</p> / <p>Abstract: INTRODUCTION: Metabolically healthy obese (MHO) individuals are characterized by absence of metabolic syndrome and/or insulin resistance and inflammation. Little is known about the role of autonomic nervous system in development of cardiometabolic complications in obese people and about its influence on the specific adipose tissue distribution. AIM: Analysis of the hearth rate variability (HRV) in metabolically healthy (MHO) and unhealthy (MUO) obese people, its connection with adipose tissue distribution, and age dependent dynamics of HRV. MATERIAL AND METHODS: A total of 125 obese patients of both sexes underwent anthropometric measurements in order to assess adipose tissue mass and distribution, body composition was assessed, blood samples were taken in order to analyze parameters of lipid and lipoprotein profile, condition of glycoregulation and inflammatory markers, blood pressure was measured and short term HRV was conducted. Data were statisticaly analyzed using SPSS 11.5. RESULTS: HRV measures did not differ significantly between MHO and MUO men. MHO women had higher values of RRNN, SDNN, RMSSD, pNN50, LF, HF and TP compared to the MUO women, influence of metabolic profile was 6,6-11,2% (p˂0,01), presented through partial shared variance. After controlling for anthropometric factors higher HF persisted in MHO women. Differences in RRNN, pNN50 and TP between MHO and MUO premenopausal women (higher values of MHO, p˂0,05) were lost after controlling for blood pressure. Insulinemia influenced the difference in RRNN between MHO and MUO premenopausal women, partial shared variance 7,6%. SAD in women was connected negatively with the LF/HF and LFnorm, and positively with HFnorm, partial shared variance 8,4-11,9% (p˂0,05). Anterior forearm skinfold in women correlated positively with LF and LF/HF, and negatively with HFnorm (p˂0,01). Visceral fat mass predicted significantly HRV in men, partial shared variance 13-34% (p˂0,01). Within the upper tertile of HRV measures RMSSD, pNN50 and LF in MUO people, HOMA was significantly lower (p˂0,05). In MUO SDNN, RMSSD, lnpNN50, lnLF,lnHF and TP significantly decreased in the period from 19-29 to 40-49 years. In MHO people the change in HF was noticeable in the fourth decade of life. CONCLUSION: MHO women have significantly higher levels of HRV markers comparing to the MUO. The differences in HRV measures are influenced by metabolic criteria used, predominantly by insulinemia, blood pressure and central fat mass. In women, central distribution of adipose tissue correlates with reduced cardiac sympathetic activity, while the connection of peripheral fat mass distribution with components of autonomic nervuos system activity is reverse. In men, central fat mass, but not peripheral, is significantly associated with HRV. MUO people with lower HRV have a higher degree of insulin resistance, while the level of HRV measures does not affect insulin sensitivity in MHO individuals. Significant age-dependent decrease in both ANS representatives of HRV measures was noticed in MUO people, unlike MHO individuals.</p>

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