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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

Avaliação do efeito da dessincronização circadiana sobre o câncer de mama e utilização terapêutica de melatonina em ratas sprague-dawley

Sasso, Etianne Martini January 2013 (has links)
O câncer de mama é o tipo de câncer que mais acomete as mulheres e a principal causa de morte na faixa entre 40 e 55 anos. Apesar de apresentar variação internacional, suas taxas seguem aumentando mundialmente, sendo até cinco vezes mais frequente em países desenvolvidos. A industrialização gera aumento da exposição à luz durante a noite, o que causa supressão de melatonina. A melatonina é o principal hormônio secretado pela glândula pineal e possui atividade oncostática e antioxidante, interfere no controle do ciclo celular, função imunológica e nos hormônios esteróides. O objetivo desta dissertação e apresentar o racional e o desenvolvimento do estudo cujo objetivo foi avaliar o efeito da terapia com melatonina sobre o desenvolvimento de tumores mamários em ratas expostas ou não a dessincronização circadiana. A indução da carcinogênese mamária foi através de administração intragástrica de DMBA em 39 ratas Sprague-dawley entre 41 e 46 dias. Os animais foram randomizados em 04 grupos, Sincronizados sem tratamento, Dessincronizados sem tratamento, Sincronizados com melatonina e Dessincronizados com melatonina. Os grupos Sincronizados foram mantidos em ciclo claro/escuro de 12/12 horas e os dessincronizados a ciclo claro/escuro de 11/11 horas, durante 8 semanas. O desenvolvimento tumoral ocorreu em 32 animais (82,05%), totalizando 73 tumores. A melatonina apresentou efeitos benéficos quanto a multiplicidade tumoral, grau histológico, tamanho dos tumores e peso dos animais, enquanto que a dessincronização não interferiu de forma significativa na carcinogênese mamária. / Breast cancer is the type of cancer that most affects women and the leading cause of death in the age between 40 and 55 years. Despite presenting international variation, their rates continue to increase worldwide, with up to five times more common in developed countries. The industrialization generates increased exposure to light at night, which causes suppression of melatonin. Melatonin is the main hormone secreted by the pineal gland and has oncostatic and antioxidant activity, interferes with cell cycle control, immune function and steroid hormones. The aim of this dissertation and present the rationale and development of the study whose objective was to evaluate the effect of melatonin therapy on the development of mammary tumors in rats exposed or not the circadian desynchronization. Induction of mammary carcinogenesis was via intragastric administration of DMBA in 39 Sprague- Dawley rats between 41 and 46 days. The animals were randomized into 04 groups, Synchronized and untreated, desynchronized and untreated, synchronized and with melatonin, desynchronized and with melatonin. Synchronized Groups were kept in a light / dark cycle of 12/12 hours and the desynchronized in a light / dark cycle of 11/11 hours for 8 weeks. The tumor development occurred in 32 animals (82.05%), totaling 73 tumors. Melatonin showed beneficial effects on tumor multiplicity, histological grade, tumor size and weight of the animals, while desynchronization did not interfere significantly in breast carcinogenesis.
2

Avaliação do efeito da dessincronização circadiana sobre o câncer de mama e utilização terapêutica de melatonina em ratas sprague-dawley

Sasso, Etianne Martini January 2013 (has links)
O câncer de mama é o tipo de câncer que mais acomete as mulheres e a principal causa de morte na faixa entre 40 e 55 anos. Apesar de apresentar variação internacional, suas taxas seguem aumentando mundialmente, sendo até cinco vezes mais frequente em países desenvolvidos. A industrialização gera aumento da exposição à luz durante a noite, o que causa supressão de melatonina. A melatonina é o principal hormônio secretado pela glândula pineal e possui atividade oncostática e antioxidante, interfere no controle do ciclo celular, função imunológica e nos hormônios esteróides. O objetivo desta dissertação e apresentar o racional e o desenvolvimento do estudo cujo objetivo foi avaliar o efeito da terapia com melatonina sobre o desenvolvimento de tumores mamários em ratas expostas ou não a dessincronização circadiana. A indução da carcinogênese mamária foi através de administração intragástrica de DMBA em 39 ratas Sprague-dawley entre 41 e 46 dias. Os animais foram randomizados em 04 grupos, Sincronizados sem tratamento, Dessincronizados sem tratamento, Sincronizados com melatonina e Dessincronizados com melatonina. Os grupos Sincronizados foram mantidos em ciclo claro/escuro de 12/12 horas e os dessincronizados a ciclo claro/escuro de 11/11 horas, durante 8 semanas. O desenvolvimento tumoral ocorreu em 32 animais (82,05%), totalizando 73 tumores. A melatonina apresentou efeitos benéficos quanto a multiplicidade tumoral, grau histológico, tamanho dos tumores e peso dos animais, enquanto que a dessincronização não interferiu de forma significativa na carcinogênese mamária. / Breast cancer is the type of cancer that most affects women and the leading cause of death in the age between 40 and 55 years. Despite presenting international variation, their rates continue to increase worldwide, with up to five times more common in developed countries. The industrialization generates increased exposure to light at night, which causes suppression of melatonin. Melatonin is the main hormone secreted by the pineal gland and has oncostatic and antioxidant activity, interferes with cell cycle control, immune function and steroid hormones. The aim of this dissertation and present the rationale and development of the study whose objective was to evaluate the effect of melatonin therapy on the development of mammary tumors in rats exposed or not the circadian desynchronization. Induction of mammary carcinogenesis was via intragastric administration of DMBA in 39 Sprague- Dawley rats between 41 and 46 days. The animals were randomized into 04 groups, Synchronized and untreated, desynchronized and untreated, synchronized and with melatonin, desynchronized and with melatonin. Synchronized Groups were kept in a light / dark cycle of 12/12 hours and the desynchronized in a light / dark cycle of 11/11 hours for 8 weeks. The tumor development occurred in 32 animals (82.05%), totaling 73 tumors. Melatonin showed beneficial effects on tumor multiplicity, histological grade, tumor size and weight of the animals, while desynchronization did not interfere significantly in breast carcinogenesis.
3

Avaliação do efeito da dessincronização circadiana sobre o câncer de mama e utilização terapêutica de melatonina em ratas sprague-dawley

Sasso, Etianne Martini January 2013 (has links)
O câncer de mama é o tipo de câncer que mais acomete as mulheres e a principal causa de morte na faixa entre 40 e 55 anos. Apesar de apresentar variação internacional, suas taxas seguem aumentando mundialmente, sendo até cinco vezes mais frequente em países desenvolvidos. A industrialização gera aumento da exposição à luz durante a noite, o que causa supressão de melatonina. A melatonina é o principal hormônio secretado pela glândula pineal e possui atividade oncostática e antioxidante, interfere no controle do ciclo celular, função imunológica e nos hormônios esteróides. O objetivo desta dissertação e apresentar o racional e o desenvolvimento do estudo cujo objetivo foi avaliar o efeito da terapia com melatonina sobre o desenvolvimento de tumores mamários em ratas expostas ou não a dessincronização circadiana. A indução da carcinogênese mamária foi através de administração intragástrica de DMBA em 39 ratas Sprague-dawley entre 41 e 46 dias. Os animais foram randomizados em 04 grupos, Sincronizados sem tratamento, Dessincronizados sem tratamento, Sincronizados com melatonina e Dessincronizados com melatonina. Os grupos Sincronizados foram mantidos em ciclo claro/escuro de 12/12 horas e os dessincronizados a ciclo claro/escuro de 11/11 horas, durante 8 semanas. O desenvolvimento tumoral ocorreu em 32 animais (82,05%), totalizando 73 tumores. A melatonina apresentou efeitos benéficos quanto a multiplicidade tumoral, grau histológico, tamanho dos tumores e peso dos animais, enquanto que a dessincronização não interferiu de forma significativa na carcinogênese mamária. / Breast cancer is the type of cancer that most affects women and the leading cause of death in the age between 40 and 55 years. Despite presenting international variation, their rates continue to increase worldwide, with up to five times more common in developed countries. The industrialization generates increased exposure to light at night, which causes suppression of melatonin. Melatonin is the main hormone secreted by the pineal gland and has oncostatic and antioxidant activity, interferes with cell cycle control, immune function and steroid hormones. The aim of this dissertation and present the rationale and development of the study whose objective was to evaluate the effect of melatonin therapy on the development of mammary tumors in rats exposed or not the circadian desynchronization. Induction of mammary carcinogenesis was via intragastric administration of DMBA in 39 Sprague- Dawley rats between 41 and 46 days. The animals were randomized into 04 groups, Synchronized and untreated, desynchronized and untreated, synchronized and with melatonin, desynchronized and with melatonin. Synchronized Groups were kept in a light / dark cycle of 12/12 hours and the desynchronized in a light / dark cycle of 11/11 hours for 8 weeks. The tumor development occurred in 32 animals (82.05%), totaling 73 tumors. Melatonin showed beneficial effects on tumor multiplicity, histological grade, tumor size and weight of the animals, while desynchronization did not interfere significantly in breast carcinogenesis.
4

Enjeux socio-urbains du noctambulisme : Les cas de Paris et Madrid au début du XXIe siècle / Socio-urban issues of night-strolling : The case studies of Paris and Madrid at the beginning of the 21st century

Guerin, Florian 23 February 2017 (has links)
Le noctambulisme est un phénomène émergeant dans les villes métropolitaines dynamiques, telles que Paris et Madrid. Sortir en ville la nuit est une pratique démocratisée parmi les jeunes urbains, s’extériorisant des lieux marchands et assimilant en quantité alcool, tabac et drogues. Les représentations sociales négatives font référence tant à une problématique de santé publique (nommée la « défonce » des jeunes vulnérables), qu’à une problématique morale du bien « vivre ensemble ». La symbolique nocturne accentue ces traits.La nuit est devenue un enjeu électoral. Analyser la construction de la politique publique de la vie nocturne rend compte du décalage des acteurs en négociation avec le noctambulisme. La légitimation des dispositifs sociotechniques de répression s’effectue au moyen d’une participation publique biaisée, dont les sortants sont absents. Les résidents-plaignants s’attaquent au bruit des terrasses, les exploitants d’établissements défendent le développement économique de leur activité, les institutionnels encouragent l’attractivité touristique nocturne.Or, ce phénomène social met en lumière la désynchronisation des rythmes sociaux entre eux et des temporalités urbaines, relative à la troisième modernité. Comprendre comment les sortants publicisent en situation cette désynchronisation permet de mettre à jour les valeurs et normes produites. Il s’agit d’étudier leurs tactiques face à la programmation urbaine, la gestion du stigmate qu’ils portent, les formes de légitimation dans l’investissement ordinaire des nuits urbaines. En leur redonnant la parole, apparaissent des conflits symboliques de cohabitation nocturne, une problématique de reconnaissance de la jeunesse / Night-strolling is a phenomenon emerging in the dynamic metropolitan cities like Paris and Madrid. Having party in town during the night-time is a practice democratized among urban young people. They go out of the merchant locations and take a large quantity of alcohol, tobacco and drugs. The negative social representations refer to a public health problem (“stoned” vulnerable young people) and a legal problem of the way to “live together”. Night symbolic highlights these dimensions. Night-time has become an electoral issue. Analyzing the construction of a public policy about nightlife reflects the gap between the actors in negotiation and the night-strolling. A biased public participation – without the night-strollers - allows the legitimation of socio-technical systems of repression. Residents-plaintiffs attack the noise terraces, ownerships of night-enterprises defend the economic development and institutional actors encourage night tourism attraction. However, this social phenomenon highlights the desynchronization of social rhythms and urban temporalities, specific to the third modernity. Understanding how young people publicize this desynchronization in situation give elements about norms and values produced. This study deals with their tactics face the urban planning, the management of the stigma they carry, the forms of legitimization in the ordinary placement of urban nights. The symbolic conflicts of nocturnal cohabitation emerge by the voice of night-strollers: a youth recognition problem
5

Construction of an Electroencephalogram-Based Brain-Computer Interface Using an Artificial Neural Network

KOBAYASHI, Takeshi, HONDA, Hiroyuki, OGAWA, Tetsuo, SHIRATAKI, Tatsuaki, IMANISHI, Toshiaki, HANAI, Taizo, HIBINO, Shin, LIU, Xicheng 01 September 2003 (has links)
No description available.
6

Desynchronized pathways of contentious politics : The interplay between digital social movements and political parties on the digital electoral arena

Östin, Emma January 2021 (has links)
This thesis explores the interplay between digital social movements and political parties on social media. The overarching aim of the thesis is to contribute to the understanding of how the digitalization of the electoral arena has transformed social movements, and how this affects the political parties' perceptions of them. The theoretical framework consists of three analytical lenses to conceptualize this interplay, these are George and Leidner’s (2019) categorization and classification of digital activism, Gunnar Sjöblom’s (1968) theory on partystrategies in a multiparty system, and Anne Kaun’s (2017) concept desynchronization. Acombination of methods is used, including network analysis and interviews, to explore this interplay. The results of the study indicate that there is a desynchronization in the practices of digital social movements and Swedish political parties.
7

Effects of a circadian mutation on adult neurogenesis

Bahiru, Michael 01 February 2021 (has links)
Rotating shift work, irregular sleep patterns and jetlag disrupt circadian rhythms, induce or aggravate disease, and produce deficits in cognitive function. Internal misalignment, a state in which abnormal phase relationships prevail between and within organs, is widely proposed to account for these adverse effects of circadian disruption. This hypothesis has been difficult to test because phase shifts of the entraining environmental cycle lead to transient desynchrony. Thus, it remains possible that phase shifts, regardless of internal desynchrony, account for adverse effects of circadian disruption. I have used the duper mutant hamster, whose locomotor activity rhythms re-entrain 5-fold faster than wild types after a phase shift of 8 hours, to test whether internal desynchrony can account for adverse effects of jet lag on adult neurogenesis. I subjected wild type and duper female hamsters to alternating 8h phase advances and delays of the LD cycle at 16-day intervals. I injected 5-Bromo-2’-deoxyuridine (BrdU, a thymidine analogue) after the 4th shift and collected brains after the 8th shift. As expected, mutants re-entrained activity rhythms more rapidly than did wild types. On the other hand, estrous cycles, as assessed by vaginal smears, were rarely disrupted by repeated phase shifts in either genotype. I next compared cell proliferation and neurogenesis in the subgranular zone of the hippocampus between Duper mutants and wild type siblings using the S-phase marker BrdU and the neuronal marker NeuN. I assessed the total number of BrdU cells in the subgranular zone of the hippocampus, as the proportion that expressed NeuN. Duper mutants had more BrdU-ir cells, and more BrdU+/NeuN+ cells than did wild types, whether or not they experienced phase shifts, revealing an unexpected increase in neurogenesis. Surprisingly, repeated phase shifts increased neurogenesis in WT but not duper hamsters. Despite the increase in neurogenesis, phase shifts reduced the number of adult-born non-neuronal (BrdU+/NeuN-) cells in WT hamsters but had no such effect on duper mutants. In addition, the duper mutation increases hippocampal neurogenesis regardless of circadian. Our results suggest that adult-born non-neuronal cells are most vulnerable to circadian disruption, and that internal desynchrony promotes their demise. disruption.
8

Accurate Method To Measure Harmonics And Interharmonics In Shipboard Power Quality Analysis

Kondabathini, Anil Kumar 13 May 2006 (has links)
This thesis describes a novel approach that utilizes a special property of the Hanning window to accurately detect the fundamental frequency of the data signal in the presence of harmonic and interharmonic interference. After obtaining the fundamental frequency, the same procedure is applied to all possible harmonics to be filtered for further analysis of the interharmonics. The proposed approach is validated using numerical tests. In the literature, different authors have shown the difficulty of extracting a synchronized sampling frequency from the analyzed signal and discussed the effect of deviation of the fundamental in the presence of harmonics. This thesis suggests a new approach to overcome the difficulties, even if the interharmonics present are in frequency bins near the fundamental. In order to perform the interharmonic analysis, the author followed the IEC standard draft signal processing recommendations, with the exception of using a weighted Hanning window instead of a rectangular window in order to minimize the effect of the spectral leakage, and to minimize the effect of interharmonics on the main harmonics.
9

World of faces, words and actions : Observations and neural linkages in early life

Handl, Andrea January 2016 (has links)
From the start of their lives, infants and young children are surrounded by a tremendous amount of multimodal social information. One intriguing question in the study of early social cognition is how vital social information is detected and processed and how and when young infants begin to make sense of what they see and hear and learn to understand other people’s behavior. The overall aim of this thesis was to provide new insights to this exciting field. Investigating behavior and/or neural mechanisms in early life, the three different studies included in this thesis therefore strive to increase our understanding on perception and processing of social information. Study I used eye-tracking to examine infants´ observations of gaze in a third-party context. The results showed that 9-, 16- and 24-month-old infants differentiate between the body orientations of two individuals on the basis of static visual information. More particularly, they shift their gaze more often between them when the social partners face each other than when they are turned away from each other. Using ERP technique, Study II demonstrated that infants at the age of 4 to 5 months show signs of integrating visual and auditory information at a neural level. Further, direct gaze in combination with backwards-spoken words leads to earlier or enhanced neural processing in comparison to other gaze-word combinations. Study III, also an EEG investigation, found that children between 18 and 30 months of age show a desynchronization of the mu rhythm during both the observation and execution of object-directed actions. Also, the results suggest motor system activation when young children observe others’ mimed actions. To summarize, the findings reported in this thesis strengthen the idea that infants are sensitive to others´ gaze and that this may extend to third-party contexts. Also, gaze is processed together with other information, for instance words, even before infants are able to understand others’ vocabulary. Furthermore, the motor system in young children is active during both the observation and imitation of another person’s goal-directed actions. This is in line with findings in infants, children and adults, indicating that these processes are linked at neural level.
10

Tempos escolares: os horários escolares e o cotidiano docente / School times: school hours and daily teacher

Silva, Robson Ferreira da 15 February 2019 (has links)
INTRODUÇÃO Este é um estudo sobre os horários escolares e sua relação com o cotidiano dos professores e os possíveis impactos que a homogeneização de horários e a realização das atividades podem exercer sobre seus ritmos biológicos. Os horários escolares podem afetar as rotinas diárias dos professores, induzindo a dessincronização dos ritmos biológicos e consequentes problemas de saúde. Entre esses problemas, as alterações no ciclo vigília/sono são as mais conhecidas. HIPÓTESE Esses conflitos podem levá-los a privações de sono e uma dessincronização de seus ritmos biológicos, obrigando-os a uma espécie de enquadramento dentro do sistema imposto, mas com riscos à sua saúde. OBJETIVO Avaliar a adaptação dos professores aos horários escolares, associando suas preferências de tolerância à maturidade ao grau de satisfação com suas condições de trabalho. MÉTODOS Foram estudados 25 professores (4 homens e 21 mulheres) com idades entre 28 e 49 anos, que trabalham em duas escolas públicas da região metropolitana de São Paulo. Foram aplicados os seguintes instrumentos: diário de atividades diárias (23 dias consecutivos), Escala de Sonolência de Karolinska (dois pontos, início da tarde e início da noite), preferências de matutinidade-vespertinidade com questionário de Horne e Östberg, Questionário Satisfação no Trabalho e entrevistas com grupos focais. RESULTADOS: A análise dos dados da Escala de Karolinska mostrou que nos finais de semana houve uma variação da sonolência ao longo do dia [F(3,66) = 5,1; p < 0,01]. As comparações mostraram que a sonolência média dos professores avaliada às 13:33 ± 1,4 horas (KSS=4,2 ±1,95) e às 17:40 ± 1,25 horas (KSS=4,6±1,32) foi menor em relação às 21:35 ± 1,14 horas (KSS=5,9 ± 2). Nos dias de semana não foi observada nenhuma diferença [F(3,66) - 2,01; p>0,05]. Com os resultados do Questionário OSI, podemos perceber que o índice de insatisfação foi mais acentuado nos quesitos remuneração, participação nas decisões e quantidade de tarefas; e o de satisfação, os mais significativos foram relacionamento e conteúdo. Ficaram evidenciados ainda, má qualidade do sono nos professores caracterizados como vespertinos, devido ao horário de trabalho em relação com os matutinos. Ficou relatada alimentação inadequada devido aos deslocamentos e horários irregulares de trabalho, além da dificuldade em ajustar os horários de trabalho com suas relações sociais. CONCLUSÃO Os horários escolares influenciam na organização temporal dos professores, afetando seu sono, saúde e qualidade de vida / INTRODUCTION This is a study about the school schedules and their relationship with teachers\' daily life and the possible impacts that the homogenization of schedules and the accomplishment of activities can influence their biological rhythms. School schedules may affect daily routines of teachers, inducing desynchronization of biological rhythms and consequent health problems. Among these problems, changes in the sleep/wake cycle are the best known. HYPOTHESIS These conflicts can lead to sleep deprivation and a desynchronization of their biological rhythms, forcing an adaptation to the work schedule in turn may compromise their heal condition. OBJECTIVE Evaluate adaptation of teachers to school schedules linking their morningness-eveningness preferences to degree of satisfaction with their work conditions. METHODS We studied 25 teachers (4 males and 21 females) aged 28-49 years old, working at two public school in the metropolitan area of São Paulo. The following instruments were applied : daily activities diary (23 consecutive days), Karolinska Sleepiness Scale (at two ponts, early afternoon and early evening), Morningness-eveningness preferences with the Horne and Östbergs questionnaire, Satisfaction at work questionnaire and focal group interviews. RESULTS Data analysis of the Karolinska Scale showed that at weekends there was a variation of sleepiness throughout the day [F (3.66) = 5.1; p <0.01]. The Comparisons showed that the mean teacher drowsiness assessed at 13:33 ± 1,4 hours (KSS = 4,2 ± 1,95) and at 17:40 ± 1.25 hours (KSS = 4,6 ± 1,32 ) was lower in relation to 21:35 ± 1,14 hours (KSS = 5,9 ± 2). On weekdays no difference was observed [F (3,66) = 2,01; p> 0,05]. The OSI Questionnaire showed that the dissatisfaction was more pronounced in terms of remuneration, participation in decisions and quantity of tasks; and satisfaction, the most significant were relationship, content, poor quality of sleep was still evident in the teachers characterized as evening because of the morning work schedule in relation to the morning ones. Evening oriented teachers show worse sleep quality than their morning-oriented colleagues. Inadequate feeding routines linked to irregular working schedules as well as compromised social relations have been found in our sample. CONCLUSION: School schedules influence temporal organization of teachers affecting their sleep, health and quality of life

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