• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Estimativa do número de cardiomiócitos do ventrículo esquerdo em suínos (Sus scrofa) / Estimation of the cardyomyocites number in the left ventrcle in swine (Sus scrofa)

Sarmento, Carlos Alberto Palmeira 26 June 2009 (has links)
Os estudos relacionados ao coração têm sido realizados ao longo dos anos de forma bastante comum, tendo em vista a grande importância que este órgão tem na medicina. Problemas relacionados ao mesmo são uma das principais causas de mortes e internações no Brasil e no mundo, por causa disso, avanços no que diz respeito a inovações tecnológicas e novas metodologias de estudo tem sido propostas cada vez com mais freqüência, e, o suíno tem se mostrado um modelo bastante útil, pois apresenta diversas similaridades em relação ao ser humano.O uso da estereologia se encaixa nesta nova busca, pois através de suas ferramentas nos proporciona excelentes resultados a níveis de mensuração, e quantificação de estruturas microscópicas. O objetivo desse estudo foi obter valores referentes à quantificação de cardiomiócitos do ventrículo esquerdo em suínos normais. Utilizaram-se 3 suínos fêmeas pesando em torno de 25kg, os quais após serem eutanasiados tiveram o coração retirado e suas câmaras separadas. Em seguida lâminas referentes a esse material foram preparadas e fotografadas, para serem analizadas utilizando-se o disector e o nucleator como ferramentas estereologicas. Os resultados nos mostram que a média de peso do ventrículo esquerdo dos animais foi de 660 mg, o volume médio dos cardiomiócitos foi de 16.32 µm³, a média do numero de cardiomiócitos foi de 3,91x108, enquanto que a média do volume de cardiomiócitos que ocupam o ventrículo esquerdo foi de 3,32x106. / Investigations involving the heart have been largely carried out all over the years due to its importance in medicine. Heart diseases are the one of the major causes of deaths and hospitalizations in Brazil and worldwide. In this context, technological innovations and progresses in methodological investigation have been frequently proposed; Swine has been shown as a useful model due to similarities to human. The application of stereological tools for investigations in the morphology of the heart has been intensely applied based on the reliability on the results for measuring and quantification. This study aimed to evaluate morphological and quantitative aspects of cardiomyocytes in the left ventricle in healthy swine. Three female swine, averaging 25 kg were euthanasiated and have the hearth chambers separated. Left ventricles were fixed and slides obtained. Images were acquired and analyzed by dissector and nucleator. The results showed us that the average weight of the left ventricle of the animals was 660 mg, the mean volume of cardiomyocytes was 16:32 µm3, the average number of cardiomyocytes was 3.91 x108, while the average volume of cardiomyocytes that occupy the left ventricle was 3.32 x106.
2

Estimativa do número de cardiomiócitos do ventrículo esquerdo em suínos (Sus scrofa) / Estimation of the cardyomyocites number in the left ventrcle in swine (Sus scrofa)

Carlos Alberto Palmeira Sarmento 26 June 2009 (has links)
Os estudos relacionados ao coração têm sido realizados ao longo dos anos de forma bastante comum, tendo em vista a grande importância que este órgão tem na medicina. Problemas relacionados ao mesmo são uma das principais causas de mortes e internações no Brasil e no mundo, por causa disso, avanços no que diz respeito a inovações tecnológicas e novas metodologias de estudo tem sido propostas cada vez com mais freqüência, e, o suíno tem se mostrado um modelo bastante útil, pois apresenta diversas similaridades em relação ao ser humano.O uso da estereologia se encaixa nesta nova busca, pois através de suas ferramentas nos proporciona excelentes resultados a níveis de mensuração, e quantificação de estruturas microscópicas. O objetivo desse estudo foi obter valores referentes à quantificação de cardiomiócitos do ventrículo esquerdo em suínos normais. Utilizaram-se 3 suínos fêmeas pesando em torno de 25kg, os quais após serem eutanasiados tiveram o coração retirado e suas câmaras separadas. Em seguida lâminas referentes a esse material foram preparadas e fotografadas, para serem analizadas utilizando-se o disector e o nucleator como ferramentas estereologicas. Os resultados nos mostram que a média de peso do ventrículo esquerdo dos animais foi de 660 mg, o volume médio dos cardiomiócitos foi de 16.32 µm³, a média do numero de cardiomiócitos foi de 3,91x108, enquanto que a média do volume de cardiomiócitos que ocupam o ventrículo esquerdo foi de 3,32x106. / Investigations involving the heart have been largely carried out all over the years due to its importance in medicine. Heart diseases are the one of the major causes of deaths and hospitalizations in Brazil and worldwide. In this context, technological innovations and progresses in methodological investigation have been frequently proposed; Swine has been shown as a useful model due to similarities to human. The application of stereological tools for investigations in the morphology of the heart has been intensely applied based on the reliability on the results for measuring and quantification. This study aimed to evaluate morphological and quantitative aspects of cardiomyocytes in the left ventricle in healthy swine. Three female swine, averaging 25 kg were euthanasiated and have the hearth chambers separated. Left ventricles were fixed and slides obtained. Images were acquired and analyzed by dissector and nucleator. The results showed us that the average weight of the left ventricle of the animals was 660 mg, the mean volume of cardiomyocytes was 16:32 µm3, the average number of cardiomyocytes was 3.91 x108, while the average volume of cardiomyocytes that occupy the left ventricle was 3.32 x106.
3

Untersuchungen zu neuroanatomischen Veränderungen beim Gesangslernen des Zebrafinken Taeniopygia guttata

Halbach, Viola von Bohlen und 10 November 2005 (has links)
Der Gesangserwerb bei Singvögeln ist ein etabliertes Modell zur Erforschung von Lern- und Gedächtnisprozessen. Für die Kontrolle des Gesangsverhaltens von Singvögeln ist ein neuronales Netzwerk verantwortlich, das als Gesangssystem bezeichnet wird. Innerhalb dieses Gesangssystems unterscheidet man zwei Hauptstränge: eine prämotorische Bahn, die für die Steuerung des Gesangs verantwortlich ist, und eine anteriore Vorderhirnschleife („anterior forebrain pathway"; AFP), die mit der Niederlegung eines Gesangsmusters im Gedächtnis und mit dem Abgleich des gehörten Gesangs an dieses Gesangsmuster in Zusammenhang gebracht wird. Bei Zebrafinken (Taeniopygia guttata) lernen nur die Männchen singen, während Weibchen lediglich angeborene Kontaktrufe äußern. Gemeinsam ist beiden Geschlechtern, dass sie arteigenen Gesang, in Form eines Gesangsmusters im Gedächtnis speichern. In der vorliegenden Arbeit wurde gezeigt, dass die Konnektivitäten innerhalb der AFP in beiden Geschlechtern ähnlich verlaufen. Auf diesen Ergebnissen aufbauend wurden die Gesangsareale der AFP adulter Zebrafinken vergleichend zwischen den Geschlechtern bezüglich ihrer Volumenausbildung untersucht und die Anzahl, Dichte und Größe der Neurone und deren Zellkerne innerhalb dieser Gesangsareale bestimmt. Des Weiteren wurden adulte Zebrafinken auf Folgen gesangsdeprivierter Aufzucht untersucht, in der Annahme, dass morphologische Unterschiede zwischen sozial und gesangsdepriviert aufgezogenen Tieren Hinweise auf Ort und Art der Speicherung des erlernten Gesangsmusters geben könnten. Solche Veränderungen wurden bezüglich des Volumens des Nucleus dorsolateralis medialis des anterioren Thalamus (DLM) und der Neuronendichte im Nucleus robustus arcopallii (RA) gesangsdeprivierter Männchen nachgewiesen. Die bei Weibchen ermittelten morphologischen Unterschiede durch gesangsdeprivierte Aufzucht konzentrierten sich auf den RA, in dem sowohl das Arealvolumen als auch die Größe der Neurone und der Nuklei signifikant kleiner waren. Da Zebrafinkenweibchen lediglich angeborene Kontaktrufe äußern, an deren Produktion der RA nicht beteiligt ist, könnten diese deprivationsbedingten Veränderungen in Zusammenhang mit der Speicherung des arteigenen Gesangsmusters stehen. / Song learning has emerged as one of the leading model systems for studying learning in vertebrates. In the avian brain there is a specific neuronal network, the so called song system, that controls song behaviour. This song system consists of two major pathways: the motor pathway which is responsible for song production, and the anterior forebrain pathway (AFP) which is important for song acquisition and adjustment of their vocalization to the learned song pattern. In zebra finches (Taeniopygia guttata) males learn to sing, whereas females only produce congenital contact calls. However, both sexes store a species specific song template in their memory. In this study it has been shown that there is high similarity between the connectivities of the AFP in males and females. Based on this, the song nuclei of the AFP of adult male and female zebra finches have been analyzed, concerning their volume, their neuronal number, density and size and whether differences between both sexes do exist. Furthermore, the impact of song deprivation in adult zebra finches has been examined. This study was based on the assumption that morphological differences between social and song deprived reared birds could give evidence for the place and mode of storing the learned song pattern. Differences between social and song deprived reared males were found in both the volume of the dorsolateral nucleus of the anterior thalamus (DLM) and the neuronal density in the robust nucleus of the arcopallium (RA). In females, morphological changes due to song deprivation were mainly found in RA. In this brain area the volume as well as the size of neurons and their nuclei were singnificantly reduced. Since females only produce congenital contact calls and since the production of these calls does not require the RA, the changes induced by song deprivation in females might be related to the storage of the conspecific song pattern.
4

Vliv zvýšené koncentrace CO2 a ozářenosti na kvantitativní parametry mezofylových buněk smrku ztepilého / The effect of elevated CO2 concentration and irradiation on quantitative parameters of mesophyll cells of Norway spruce

Kubínová, Zuzana January 2010 (has links)
KUBÍNOVÁ, Zuzana. The effect of elevated CO2 concentration and irradiation on quantitative parameters of mesophyll cells of Norway spruce. Prague, 2010. 74 p. Master's degree thesis. Faculty of Science, Charles University in Prague. Abstract The aim of the present thesis was to choose and adjust a suitable methodology for counting particles in 3D space, which would be suitable for unbiased estimation of chloroplast number in needle mesophyll cells. The disector method was used for the first time to determine the number of chloroplasts. This method enables unbiased estimation of chloroplast number in needle volume from optical sections captured from fresh free-hand sections by confocal microscope. The sections did not need any pre-processing. Another aim was to compare selected photosynthetic and anatomical characteristics of sun and shade Norway spruce needles, which were grown under different CO2 concentration. The trees were grown for eight years in ambient (during the experiment increasing from 357 up to 370 µmol CO2 ∙ mol-1 ) CO2 concentration or elevated (700 µmol ∙ mol-1 ) CO2 concentration in special glass domes on an experimental research site of the Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic at Bílý Kříž in Moravskoslezské Beskydy mountains. The sun needles...

Page generated in 0.206 seconds