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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.
1

Estudo da organiza??o funcional do sistema circadiano por meio de ferramentas computacionais e matem?ticas / Gon?alves, bsb. study of the functional organization of the circadian system through computer modeling and analysis mathematics. Tese de doutorado em psicobiologia, ufrn, 137 p?ginas, 2013

Gon?alves, Bruno da Silva Brand?o 03 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:36:40Z (GMT). No. of bitstreams: 1 BrunoSBG_DISSERT.pdf: 3965357 bytes, checksum: 7e3aabdd040d50db3f4557799b032b1d (MD5) Previous issue date: 2013-04-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Circadian rhythms are variations in physiological processes that help living beings to adapt to environmental cycles. These rhythms are generated and are synchronized to the dark light cycle through the suprachiasmatic nucleus. The integrity of circadian rhythmicity has great implication on human health. Currently it is known that disturbances in circadian rhythms are related to some problems of today such as obesity, propensity for certain types of cancer and mental disorders for example. The circadian rhythmicity can be studied through experiments with animal models and in humans directly. In this work we use computational models to gather experimental results from the literature and explain the results of our laboratory. Another focus of this study was to analyze data rhythms of activity and rest obtained experimentally. Here we made a review on the use of variables used to analyze these data and finally propose an update on how to calculate these variables. Our models were able to reproduce the main experimental results in the literature and provided explanations for the results of experiments performed in our laboratory. The new variables used to analyze the rhythm of activity and rest in humans were more efficient to describe the fragmentation and synchronization of this rhythm. Therefore, the work contributed improving existing tools for the study of circadian rhythms in mammals / Os ritmos circadianos s?o varia??es em processos fisiol?gicos que auxiliam os seres vivos na adapta??o aos ciclos ambientais. Esses ritmos s?o gerados e se sincronizam ao ciclo claro escuro por meio do n?cleo supraquiasm?tico. A integridade da ritmicidade circadiana tem grande implica??o na sa?de dos seres humanos. Atualmente sabe-se que dist?rbios nos ritmos circadianos est?o relacionados com alguns problemas da atualidade como a obesidade, propens?o a determinados tipos de c?ncer e transtornos mentais por exemplo. A ritmicidade circadiana pode ser estudada por meio de experimentos com modelos animais e diretamente nos seres humanos. Nesse trabalho utilizamos modelos computacionais para reunir resultados experimentais da literatura e explicar resultados de nosso laborat?rio. Outro foco desse trabalho foi na an?lise de dados de ritmos de atividade e repouso obtidos experimentalmente. Aqui fizemos uma revis?o sobre o uso de vari?veis utilizadas para analisar esses dados e por ?ltimo propomos uma atualiza??o na forma de calcular essas vari?veis. Os nossos modelos foram capazes de reproduzir os principais resultados experimentais da literatura e nos forneceram explica??es para resultados de experimentos realizados em nosso laborat?rio. As novas vari?veis utilizadas para analisar o ritmo de atividade e repouso em humanos se mostraram mais eficiente para descrever a fragmenta??o e sincroniza??o desse ritmo. Assim esse trabalho contribuiu aperfei?oando as ferramentas existentes para o estudo da ritmicidade circadiana nos mam?feros
2

Avalia??o do perfil de sono/vigilia em um modelo cr?nico de parkinsonismo em ratos

Silva, Cinthya Montenegro de Vasconcelos 13 May 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-03T19:56:08Z No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-05T22:10:42Z (GMT) No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) / Made available in DSpace on 2017-01-05T22:10:42Z (GMT). No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) Previous issue date: 2016-05-13 / A doen?a de Parkinson (DP) ? uma desordem neurodegenerativa e progressiva com espectro cl?nico variado. Al?m dos sintomas motores cl?ssicos tamb?m podem surgir complica??es n?o-motoras, destacando-se a? problemas cognitivos, psiqui?tricos e auton?micos. Evid?ncias demonstram que tais sintomas n?o-motores frequentemente precedem o aparecimento dos sinais motores e s?o extremamente relevantes, dado o impacto negativo que causam na qualidade de vida dos indiv?duos. Os sintomas n?o-motores podem apresentar m?ltiplas causas, dentre as quais uma poss?vel disfun??o do sistema circadiano. Dessa forma, diversos processos fisiol?gicos influenciados pelo sistema de temporiza??o circadiano (STC), como o ciclo sono/vig?lia podem se mostrar alterados em pacientes acometidos pela DP. O STC ? respons?vel pela gera??o e manuten??o dos ritmos circadianos, que s?o oscila??es end?genas manifestadas pelos seres vivos em diversos processos fisiol?gicos e comportamentais, com per?odo em torno de 24 horas. Assim, ? fundamental a compreens?o dos efeitos da progress?o do processo patog?nico da DP sobre o perfil circadiano do ciclo sono/vig?lia e tamb?m de componentes do STC, em particular no n?cleo supraquiasm?tico (NSQ), o principal marcapasso do sistema. No presente estudo, ratos wistar jovens (6 meses) e de meia-idade (10 meses) foram submetidos a um modelo animal cr?nico de DP com administra??o de reserpina durante 20 dias. Ao longo do tratamento foram realizadas an?lises comportamentais do sono, bem como a avalia??o motora dos animais. Ap?s o fim do tratamento, foram realizadas an?lises imunoistoqu?micas no NSQ dos animais. Nossos resultados mostraram que o tratamento cr?nico com reserpina promoveu comprometimento motor progressivo tanto nos animais jovens quanto nos de meia-idade. Al?m disso, as an?lises comportamentais revelaram perturba??es no ciclo sono/vig?lia dos animais tratados em compara??o aos indiv?duos controle, incluindo avan?o na fase de sono e aumento na fragmenta??o do sono. As an?lises imunistoqu?micas n?o permitiram observar efeitos significativos do tratamento com reserpina sobre a composi??o neuroqu?mica do NSQ, contudo novos estudos s?o necess?rios para a avalia??o neuroqu?mica e morfom?trica desse importante marcapasso circadiano na DP. / Parkinson?s disease (PD) is a neurodegenerative and progressive disorder with varied clinical spectrum. In addition to the classic motor symptoms may also emerge non-motor complications, highlighting cognitive, psychiatric and autonomic problems. Evidence shows that such non-motor symptoms often precede the onset of motor signs and are extremely relevant given the negative impact they have on the quality of life of the individuals. Non-motor symptoms may present multiple causes, among which a possible dysfunction of the circadian system. Therefore, many physiological processes influenced by the circadian timing system (CTS) as the sleep / wake cycle can show alterations in PD patients. In this study we sought to evaluate the profile of sleep/wake behavior in a chronic model of PD in rats compared with possible neurochemical changes in the suprachiasmatic nucleus(SCN), the main pacemaker of the CTS. To this end, young (6 months) and middle-age (10 months) wistar rats were subjected to a treatment with repeated administration of reserpine (0.1 mg / kg) for 20 days. During treatment sleep behavioral analysis were performed as well as the motor assessment of the individuals. After the end of treatment, immunohistochemical analyzes were performed in the SCN of the animals. Our results showed that chronic treatment with reserpine promoted progressive motor impairment both in young as in middle-age animals. It is noticed significant losses from the 12th day of treatment. Furthermore, the behavioral analyzes revealed disturbances in sleep / wake cycle of the treated animals compared to control subjects, including advanced sleep phase and increased sleep fragmentation. Such changes were observed from the 6th day of treatment, prior to the onset of motor symptoms. The immunohistochemical analysis not allowed to observe significant effects of treatment with reserpine on the neurochemical composition of the SCN. Thus, our data support the observation that non-motor symptoms precede the onset of motor symptoms in PD and are extremely important for early clinical diagnosis of the disease.

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