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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

Ciclos de atividade/repouso e alimentação/jejum associados ao uso de equipamentos eletrônicos: aspectos comportamentais e padrões temporais / Not informed by the author

Tatiana Harumi Seito 27 January 2017 (has links)
A energia elétrica de uso doméstico no cenário mundial é um fenômeno recente que incorporou modulações temporais na expressão dos ritmos biológicos, como os hábitos alimentares e de sono. Após sua popularização, tecnologias eletrônicas foram criadas e incorporadas às nossas rotinas diárias. O acesso à iluminação elétrica promove uma maior flexibilidade na organização temporal das nossas atividades por facilitar o controle de extensão da fase de atividade para horas mais tardias da noite. Assim, essa situação pode constituir um desafio temporal ao organismo, gerado pelas oscilações das pistas temporais, adiantando ou atrasando a ocorrência de eventos rítmicos como a alimentação/jejum, atividade/repouso e metabolismo. O estudo foi realizado com 27 universitários entre 18 a 30 anos (17 mulheres; 10 homens) nos quais o comportamento alimentar e de sono foi registrado por meio do uso de diários e os ciclos de atividade/repouso e claro/escuro por meio de actímetros. Observada uma associação indireta entre o uso de equipamentos eletrônicos e o aumento no consumo alimentar. A associação observada em relação ao uso dos equipamentos com a ingesta está mais amparada no atraso do início do sono que propicia o aumento observado da ingesta média na fase noturna. No longo prazo o atraso da fase do sono e a diminuição da sua duração pode gerar um desalinhamento na regulação da expressão dos padrões temporais de atividade/repouso e alimentação/jejum que pode alterar o padrão do comportamento alimentar / Electric energy used widely in domestic context is a recent phenomenon that incorporates temporal modulations on the expression of biological rhythms and behaviour, like food ingestion and sleep patterns. After popularization of electric energy, electronic technologies have been created and incorporated to our routines. Access to electric light can promote more flexibility on temporal organization of our activities which allow for an extension of the wake phase to later portions of the night. Thus, that situation could promote temporal challenges to the organisms, generated by oscillations of temporal signals, which may cause phase advances or delays in rhythmic events like feeding/fasting, rest/activity and metabolic functions. This study involved 27 university students between 18 to 30 years old (17 women; 10 men) where feeding and sleep behavior data were collected with feeding and sleep diaries; the rest/activity rhythm and the light/dark cycle data were collected with actimeters. The association observed in relation to the use of the electronic equipments with the food intake is supported by the delay of the beginning of rest that propitiates the increase of the average intake in the nocturnal phase. In the long term, the delay of the rest phase and the decrease of its duration can generate a misalignment in the regulation of the expression of the temporal patterns of rest/activity and feeding/fasting and thus change the temporal pattern of the feeding behavior
42

Spatial and temporal patterns and hydroclimatic controls of river ice break-up in the Mackenzie Delta, NWT

Goulding, Holly Lynn 11 December 2008 (has links)
Concern has been expressed regarding the impacts of climate change on the hydroecology of the Mackenzie Delta, thus identifying a need for better understanding of the ice break-up regime. Archived records at hydrometric stations in the delta for the period 1974 to 2006, supplemented with observations and remotely sensed imagery, are used to assemble a break-up chronology and examine spatial and temporal patterns of break-up flooding. Hydroclimatic controls on break-up are assessed by statistical, qualitative, and trend analysis of upstream discharge and downstream ice characteristics. For the most severe break-up flooding, two event types are identified: ice-driven events, with high backwater and high peak levels in the southern, eastern and western delta, and discharge-driven events, with high levels in the mid and outer delta and along Middle Channel. Break-up initiation during ice (discharge) events occurs earlier (later) than the delta average. Severity of break-up water levels is most influenced by upstream discharge, while timing is related to ice conditions and spring hydrograph rise. Rapid upstream melt and lower intensity melt in the delta prior to break-up characterize the most severe events. Trend analysis reveals a tendency toward earlier break-up, a longer prebreak-up melt interval, and a lower magnitude of hydroclimatic controls.
43

Spatial and temporal patterns and hydroclimatic controls of river ice break-up in the Mackenzie Delta, NWT

Goulding, Holly Lynn 11 December 2008 (has links)
Concern has been expressed regarding the impacts of climate change on the hydroecology of the Mackenzie Delta, thus identifying a need for better understanding of the ice break-up regime. Archived records at hydrometric stations in the delta for the period 1974 to 2006, supplemented with observations and remotely sensed imagery, are used to assemble a break-up chronology and examine spatial and temporal patterns of break-up flooding. Hydroclimatic controls on break-up are assessed by statistical, qualitative, and trend analysis of upstream discharge and downstream ice characteristics. For the most severe break-up flooding, two event types are identified: ice-driven events, with high backwater and high peak levels in the southern, eastern and western delta, and discharge-driven events, with high levels in the mid and outer delta and along Middle Channel. Break-up initiation during ice (discharge) events occurs earlier (later) than the delta average. Severity of break-up water levels is most influenced by upstream discharge, while timing is related to ice conditions and spring hydrograph rise. Rapid upstream melt and lower intensity melt in the delta prior to break-up characterize the most severe events. Trend analysis reveals a tendency toward earlier break-up, a longer prebreak-up melt interval, and a lower magnitude of hydroclimatic controls.

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