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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.
11

Person, place and context: the interaction between the social and physical environment on adverse pregnancy outcomes in British Columbia

Erickson, Anders Carl 22 September 2016 (has links)
This study was a population-based retrospective cohort of all singleton births in British Columbia for the years 2001 to 2006. The purpose of this dissertation is to examine how social and physical environment factors influence the risk of adverse pregnancy outcomes and whether they interact with each other or with maternal characteristics to modify disease risk. The main environmental factors examined include ambient particulate air pollution (PM2.5), neighbourhood socioeconomic status (SES), neighbourhood immigrant density, neighbourhood level of post-secondary education level and the urban-rural context. Census dissemination areas (DAs) were used as the neighbourhood spatial unit. The data (N=242,472) was extracted from the BC Perinatal Data Registry (BCPDR) from Perinatal Services BC (PSBC). The main perinatal outcomes investigated include birth weight and indicators of fetal growth restriction such as small-for-gestational age (SGA), term low birth weight (tLBW), and intrauterine growth restriction (IUGR), preterm birth (PTB) and gestational age, gestational diabetes mellitus (GDM) and gestational hypertension (GH). Collectively, this dissertation contributes to the perinatal epidemiological literature linking particulate air pollution and neighbourhood SES context to adverse pregnancy outcomes. Assumptions about the linear effect of PM2.5 and smoking on birth weight are challenged showing that the effects are most pronounced between low and average exposures and that the magnitude of their effect is modified by neighbourhood and individual-level characteristics. These results suggest that focusing exclusively on individual risk factors may have limited success in improving outcomes without addressing the contextual influences at the neighbourhood-level. This dissertation therefore also contributes to the public health, sociological and community-urban development literature demonstrating that context and place matters. / Graduate / 0766 / 0573 / 0768 / anderse@uvic.ca
12

Análise, imputação de dados e interfaces computacionais em estudos de séries temporais epidemiológicas / Analysis, data imputation and computer interfaces in time-series epidemiologic studies

Washington Leite Junger 01 April 2008 (has links)
efeitos são frequentemente observados na morbidade e mortalidade por doenças respiratórias e cardiovasculares, câncer de pulmão, diminuição da função respiratória, absenteísmo escolar e problemas relacionados com a gravidez. Estudos também sugerem que os grupos mais suscetíveis são as crianças e os idosos. Esta tese apresenta estudos sobre o efeito da poluição do ar na saúde na saúde na cidade do Rio de Janeiro e aborda aspectos metodológicos sobre a análise de dados e imputação de dados faltantes em séries temporais epidemiológicas. A análise de séries temporais foi usada para estimar o efeito da poluição do ar na mortalidade de pessoas idosas por câncer de pulmão com dados dos anos 2000 e 2001. Este estudo teve como objetivo avaliar se a poluição do ar está associada com antecipação de óbitos de pessoas que já fazem parte de uma população de risco. Outro estudo foi realizado para avaliar o efeito da poluição do ar no baixo peso ao nascer de nascimentos a termo. O desenho deste estudo foi o de corte transversal usando os dados disponíveis no ano de 2002. Em ambos os estudos foram estimados efeitos moderados da poluição do ar. Aspectos metodológicos dos estudos epidemiológicos da poluição do ar na saúde também são abordados na tese. Um método para imputação de dados faltantes é proposto e implementado numa biblioteca para o aplicativo R. A metodologia de imputação é avaliada e comparada com outros métodos frequentemente usados para imputação de séries temporais de concentrações de poluentes atmosféricos por meio de técnicas de simulação. O método proposto apresentou desempenho superior aos tradicionalmente utilizados. Também é realizada uma breve revisão da metodologia usada nos estudos de séries temporais sobre os efeitos da poluição do ar na saúde. Os tópicos abordados na revisão estão implementados numa biblioteca para a análise de dados de séries temporais epidemiológicas no aplicativo estatístico R. O uso da biblioteca é exemplificado com dados de internações hospitalares de crianças por doenças respiratórias no Rio de Janeiro. Os estudos de cunho metodológico foram desenvolvidos no âmbito do estudo multicêntrico para avaliação dos efeitos da poluição do ar na América Latina o Projeto ESCALA. / Air pollution is a public health problem in major urban areas and its effects are frequently observed in the morbidity and mortality due respiratory and cardiovascular causes, lung cancer, decreasing in the respiratory function, school absenteeism, and pregnancy outcomes. This thesis presents studies on the effects of air pollution on health in the Rio de Janeiro city and tackle some methodological issues on data analysis and missing data imputation in epidemiologic time series. Daily time series were used to estimate the effect of the air pollution on deaths among the elderly due to lung cancer during 2000 and 2001. The purpose of the study was to evaluate if air pollution is associated with premature deaths of people that already are in risk population. Another study was conducted to assess the relationship between air pollution and low birth weight of singleton full term babies. A crosssectional design was used on data available during the year 2002. Moderate effects of the air pollution were estimated in both studies. Methodological aspects of epidemiologic studies on air pollution are also approached. A data imputation method is presented and implemented as library for the statistical package R. The imputation methodology is evaluated and compared to others often used for data imputation in time series of air pollutant concentrations, through simulation techniques. The proposed method has shown best performance compared to those traditionally used. A brief review on the methodology used in the time series studies on the effects of air pollution on health is also presented. The issues approached in the review are also implemented as a library for the analysis of epidemiologic time series in R. The use of the library is exemplified with the analysis on the data of hospital admissions of children due to respiratory causes in the city of Rio de Janeiro. The methodological studies were carried out under the umbrella of the multi-city study to assess the effects of air pollution on health in the Latin America the ESCALA Project.
13

Análise, imputação de dados e interfaces computacionais em estudos de séries temporais epidemiológicas / Analysis, data imputation and computer interfaces in time-series epidemiologic studies

Washington Leite Junger 01 April 2008 (has links)
efeitos são frequentemente observados na morbidade e mortalidade por doenças respiratórias e cardiovasculares, câncer de pulmão, diminuição da função respiratória, absenteísmo escolar e problemas relacionados com a gravidez. Estudos também sugerem que os grupos mais suscetíveis são as crianças e os idosos. Esta tese apresenta estudos sobre o efeito da poluição do ar na saúde na saúde na cidade do Rio de Janeiro e aborda aspectos metodológicos sobre a análise de dados e imputação de dados faltantes em séries temporais epidemiológicas. A análise de séries temporais foi usada para estimar o efeito da poluição do ar na mortalidade de pessoas idosas por câncer de pulmão com dados dos anos 2000 e 2001. Este estudo teve como objetivo avaliar se a poluição do ar está associada com antecipação de óbitos de pessoas que já fazem parte de uma população de risco. Outro estudo foi realizado para avaliar o efeito da poluição do ar no baixo peso ao nascer de nascimentos a termo. O desenho deste estudo foi o de corte transversal usando os dados disponíveis no ano de 2002. Em ambos os estudos foram estimados efeitos moderados da poluição do ar. Aspectos metodológicos dos estudos epidemiológicos da poluição do ar na saúde também são abordados na tese. Um método para imputação de dados faltantes é proposto e implementado numa biblioteca para o aplicativo R. A metodologia de imputação é avaliada e comparada com outros métodos frequentemente usados para imputação de séries temporais de concentrações de poluentes atmosféricos por meio de técnicas de simulação. O método proposto apresentou desempenho superior aos tradicionalmente utilizados. Também é realizada uma breve revisão da metodologia usada nos estudos de séries temporais sobre os efeitos da poluição do ar na saúde. Os tópicos abordados na revisão estão implementados numa biblioteca para a análise de dados de séries temporais epidemiológicas no aplicativo estatístico R. O uso da biblioteca é exemplificado com dados de internações hospitalares de crianças por doenças respiratórias no Rio de Janeiro. Os estudos de cunho metodológico foram desenvolvidos no âmbito do estudo multicêntrico para avaliação dos efeitos da poluição do ar na América Latina o Projeto ESCALA. / Air pollution is a public health problem in major urban areas and its effects are frequently observed in the morbidity and mortality due respiratory and cardiovascular causes, lung cancer, decreasing in the respiratory function, school absenteeism, and pregnancy outcomes. This thesis presents studies on the effects of air pollution on health in the Rio de Janeiro city and tackle some methodological issues on data analysis and missing data imputation in epidemiologic time series. Daily time series were used to estimate the effect of the air pollution on deaths among the elderly due to lung cancer during 2000 and 2001. The purpose of the study was to evaluate if air pollution is associated with premature deaths of people that already are in risk population. Another study was conducted to assess the relationship between air pollution and low birth weight of singleton full term babies. A crosssectional design was used on data available during the year 2002. Moderate effects of the air pollution were estimated in both studies. Methodological aspects of epidemiologic studies on air pollution are also approached. A data imputation method is presented and implemented as library for the statistical package R. The imputation methodology is evaluated and compared to others often used for data imputation in time series of air pollutant concentrations, through simulation techniques. The proposed method has shown best performance compared to those traditionally used. A brief review on the methodology used in the time series studies on the effects of air pollution on health is also presented. The issues approached in the review are also implemented as a library for the analysis of epidemiologic time series in R. The use of the library is exemplified with the analysis on the data of hospital admissions of children due to respiratory causes in the city of Rio de Janeiro. The methodological studies were carried out under the umbrella of the multi-city study to assess the effects of air pollution on health in the Latin America the ESCALA Project.
14

Short-term effects of ambient temperature on daily deaths and hospital admissions

Rocklöv, Joacim January 2010 (has links)
Background: Incidence of death and hospitalizations have been observed to depend on short-term changes in weather and to increase with extreme temperatures. This thesis aims to strengthen the scientific knowledge on the relationship between temperature and daily deaths, but also the relationship between temperature and daily hospital admissions. Methods: We constructed time series regression models using daily counts of death and daily weather from the Stockholm area incorporating adjustment for potential confounding factors, season, and long-term time trends. From these models, we established the short-term relationship with daily temperatures and the associated relative risks on daily deaths allowing for a delay between exposure and subsequent deaths. Daily hospital admissions and daily temperatures were analyzed correspondingly using data from Skåne. Results: Hot and cold temperatures significantly impact on mortality rates as well as rates of hospitalization in Sweden. We found an immediate heat effect on daily deaths, while the impacts of cold temperatures were delayed up to a week after exposure. Cold-related deaths are generally cardiovascular in nature, while deaths resulting from warm temperatures are cardiovascular, respiratory as well as non-cardiorespiratory in nature. The impacts following a heat wave appear to increase proportionally with the length of the extreme hot conditions. The results suggest that the population aged 45 years and older is the main group at elevated risk of death when exposed to high and low temperatures. Moreover, the results suggest that there are several factors of susceptibility on an individual basis that correspond to larger relative risk with high and/or low temperatures. Daily hospitalisations increased in particular among individuals with respiratory illnesses during extreme persistent heat, whereas high temperatures in general have little impact. In contrast, hospitalizations increased for up to two weeks following exposure to cold temperatures. Conclusions: The health impacts related to temperature are a serious concern and the attributed impacts are likely to increase to some extent in the future due to an ageing population. Public health preventive strategies should be developed to prevent health consequences related to heat waves and cold temperatures. Future studies should aim at identifying susceptible individuals with elevated death risk at hot and cold ambient temperature conditions.
15

Short-term effects of ambient temperature on daily deaths and hospital admissions

Rocklöv, Joacim, January 2010 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2010.
16

Détermination de la concentration de manganèse dans l’eau potable associée à des déficits cognitifs chez l’enfant

Kullar, Savroop S. 06 1900 (has links)
No description available.
17

Early life factors influencing neurodevelopment and the study of the interrelations between different behavioural areas

Júlvez Calvo, Jordi 27 September 2007 (has links)
Antecedents: No hi ha gaire coneixement sobre el neurodesenvolupament de preescolars i la seva susceptibilitat enfront a factors ambientals. Objectius: Avaluar les respostes del neurodesenvolupament en nens i les seves característiques psicomètriques, i, si factors ambientals primerencs (ex., duració de la lactància materna i mares que fumen) poden influir tals respostes. Mètodes: Dues cohorts prospectives des del naixement en població general (Menorca (N=421) i Ribera d'Ebre (N=79)) van se seguides fins als 4 anys d'edat durant un període de dos anys (2001-2003). Els nens van ser avaluats per tres psicòlegs i els seus respectius mestres per les funcions neuropsicològiques (MCSA), els comportaments de dèficit d'atenció i d'hiperactivitat (TDAH-DSM-IV) i la competència social (CPSCS); junt amb l'administració (en persona) a les mares de qüestionaris generals.Resultats: Les respostes van mostrar característiques psicomètriques acceptables i els patrons neuropsicològics del TDAH eren consistents amb altres troballes sobre TDAH. La lactància materna de llarga durada estava associada amb una millora de totes les àrees comportamentals avaluades. Fumar durant l'embaràs estava associat a puntuacions cognitives més baixes.Conclusions: Avaluar el neurodesenvolupament a preescolars sans és factible i necessari per investigar efectes primerencs de factors ambientals i aplicar polítiques preventives de salut pública. / Background: Little is known about neurodevelopment among preschoolers and its susceptibility to environmental factors.Objectives: Assess neurodevelopmental outcomes and their psychometric characteristics in children; and, if early environmental factors (i.e., duration of breastfeeding and maternal smoking) influence the neurobehavioral outcomes. Methods: Two prospective population-based birth cohorts (Menorca (N=421) and Ribera d'Ebre county (N=79)) were followed up at the age of 4 years during a two year period (2001-2003). Children were assessed by three psychologists and their respective teachers for neuropsychological functions (MCSA), inattention-hyperactivity behaviors (ADHD-DSM-IV) and social behavior (CPSCS); in addition to maternal in person general questionnaires. Results: Outcomes showed acceptable psychometric characteristics and ADHD neuropsychological patterns were consistent with other ADHD findings. Long-term breastfeeding was associated with the improvement of all behavioral areas assessed. Maternal smoking during pregnancy was associated with lower cognitive scores.Conclusions: Assessing neurodevelopment in healthy preschoolers is feasible and necessary to investigate early effects of environmental factors and apply public health preventive policies.
18

Modelagem espacial, temporal e longitudinal: diferentes abordagens do estudo da leptospirose urbana / Space, time and longitudinal modeling: different approaches for the urban leptospirosis study

Tassinari, Wagner de Souza January 2009 (has links)
Made available in DSpace on 2011-05-04T12:42:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / (...) O objetivo desta tese foi modelar os fatores de risco associados à ocorrência de leptospirose urbana em diferentes contextos, com especial atenção para aspectos espaciais e temporais. Foram utilizadas técnicas de modelagem tais como, modelos generalizados aditivos e mistos. Também explorou-se técnicas de detecção de aglomerados espaço-temporais. (...) / Leptospirosis, a disease caused by pathogenic spirochete of the genus Leptospira, is one of the most widespread zoonoses in the world, considered a major public health problem associated with the lack of sanitation and poverty. It is endemic in Brazil, data from surveillance show that outbreaks of leptospirosis occur as cyclical annual epidemics during rainfalls. The aim of this thesis was modeling the risk factors associated with the occurrence of leptospirosis in di erent urban contexts, with particular attention to spatial and temporal aspects. We used some modeling techniques such as generalized additive and mixed models. Techniques for detection space-time clusters were also explored. This thesis has prioritized the use of free softwares - R, ubuntu linux operating system, LATEX , SatScan (this is not open source but free). This thesis was prepared in the form of three articles. In the rst article is presented a spatio-temporal analysis of leptospirosis cases occurrence in Rio de Janeiro between 1997 and 2002. Using the detection of space-time clusters - \outbreaks" method - were statistically signi cant only cluster ocorred in 1997 and 1998. Generalized Linear Mixed Models were used to evaluate the risk factors associated with the occurrence of cases that belonged to outbreaks in endemic cases. The cases belonging to the outbreaks are associated with the occurrence of rainfall over 4 mm (OR, 3.71; 95% CI, 1.83 - 7.51). There were no signi cant associations with socioeconomic covariates, in other words, being endemic or epidemic leptospirosis occurs in the same population. The second and third articles examined a seroprevalence survey and seroconversion cohort conducted in Pau da Lima community, Salvador, Bahia. In both Generalized Additive Models were used to t the exposure variables both in individuals and peridomicile context, as well as to estimate the spatial area of leptospirosis risk. The signi cant variables were: gender, age, presence of rats in the peridomicile, domicile near a trash collectin or an open sewer and domicile altitude above sea level. Studies show that individual and contextual variables explain much of the spatial variability of leptospirosis, but there are still factors that were not measured in the studies but which should be investigated. The maps of risk of seroprevalence and seroconversion show distinct regions where the spatial e ect is signi cantly di erent from the global average. It is still lack for a more robust integration between the professionals who develop and operate the GIS, epidemiologists and biostatistics. This integration represents an important advance enabling the development and use of these techniques in Public Health support. The study of prevalence and incidence of endemic areas, in the leptospirosis context, it is very complex and still grow up. The reunion of professional specialists from several areas of human knowledge (eg, clinicians, epidemiologists, geographers, biologists, statisticians, engineers, etc.), it is essential to advance the knowledge about the disease and their relationship to social inequality and environmental well to contribute to the creation of efficient and e ective measures to control endemic diseases.

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