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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

Influence of host anemia on blood-feeding rate and egg production of Aedes aegypti (L.) (Diptera : Culicidae)

Shieh, Jong-Neng 06 June 1991 (has links)
I tested a theoretical model proposing that anemia favors transmission of blood-borne parasites to vectors by accelerating the blood-feeding rate. Using Aedes aegypti, the yellow fever mosquito, initially, I was not able to confirm this phenomenon either in an artificial or a live system; anemia did not correlate with blood-feeding rate, time or volume. I then analyzed the feeding rate over different time intervals to examine the possibility that inconsistent feeding rates masked the expected results; a comparison of the blood-feeding rate at one particular time period supports the theory. I then continued investigating the influence of anemia on egg production of mosquitoes and found that anemia has negative influence on vector's fecundity. I conclude that although anemia has opposite influences on mosquitoes in blood-feeding rate and egg production, they can get, at least under certain conditions, benefit from blood-feeding on anemic hosts. / Graduation date: 1992
2

Modelos para dados de proporção: um estudo sobre a viabilidade de ovos do mosquito Aedes aegypti, mantidos em diferentes tipos de armazenamentos na Amazônia / Models for proportion data: a study about the viability of Aedes aegypti mosquito eggs, kept in different storage types in the Amazon

Amoêdo, Pedro Marinho 09 June 2014 (has links)
O presente trabalho teve por objetivo estimar o tempo que os ovos de Aedes aegypti permanecem em condições de eclodir e produzir larvas viáveis após permanecerem armazenados por determinado tempo ( viabilidade) em diferentes tipos de recipientes. Para tal, usou-se a metodologia dos modelos lineares generalizados para dados na forma de proporção. Como função de ligação, optou-se pelas funções logística e probito, como preditores lineares retas paralelas e retas concorrentes. Foi realizado um experimento, em que procurou-se simular, tanto quanto possível, o efeito das condições ambientais que os ovos de Aedes aegypti são submetidos. Os ovos foram armazenados em três recipientes (copo plástico, saco plástico e envelope de papel) e tratados com água ao final de cada período de armazenamento estabelecido. Por meio do ajuste do modelo linear generalizado binomial com função de ligação logística e preditor linear retas paralelas, foi possível predizer a viabilidade dos ovos de Aedes aegypti. Como medidas da qualidade do ajuste, usou-se o desvio residual com valor de p (nível descritivo), calculado sobre os percentis da distribuição qui-quadrado e o gráfico de probabilidade normal padrão com envelope de simulação. Verificou-se comportamento semelhante entre saco plástico e envelope de papel com respeito a viabilidade estimada dos ovos de Aedes aegypti, ambos diferindo do recipiente copo plástico que apresentou a maior viabilidade. / This work had like objective estimate the time in which the Aedes aegypti eggs remain in hatch conditions and produce viable larvae after remain a certain time (viability) in different storage types. To this, the generalized linear models methodology for data in proportion form was used. As link function was chose the logistic and probit and like linear predictors, parallel and intersecting lines. Was conducted an experiment, in which were simulated as much as possible the effect of environmental conditions in which the Aedes aegypti eggs are submitted. The eggs were stored in three containers (plastic cup, plastic bag and paper envelope) and treated with water at the end of each storage period. With the fit of the binomial generalized linear model with logistic link function and parallel lines like linear predictor, was possible predict the viability of the Aedes aegypti eggs. As quality measures of fit, the residual deviance with p-value (descriptive level), calculated on the chi-square distribution percentiles and the standard normal probability plot with simulated envelope were used. It has been found similar behaviour between plastic bag and paper envelope with respect to estimated viability of the Aedes aegypti eggs, both differing from the plastic cup that presents the highest viability.
3

Modelos para dados de proporção: um estudo sobre a viabilidade de ovos do mosquito Aedes aegypti, mantidos em diferentes tipos de armazenamentos na Amazônia / Models for proportion data: a study about the viability of Aedes aegypti mosquito eggs, kept in different storage types in the Amazon

Pedro Marinho Amoêdo 09 June 2014 (has links)
O presente trabalho teve por objetivo estimar o tempo que os ovos de Aedes aegypti permanecem em condições de eclodir e produzir larvas viáveis após permanecerem armazenados por determinado tempo ( viabilidade) em diferentes tipos de recipientes. Para tal, usou-se a metodologia dos modelos lineares generalizados para dados na forma de proporção. Como função de ligação, optou-se pelas funções logística e probito, como preditores lineares retas paralelas e retas concorrentes. Foi realizado um experimento, em que procurou-se simular, tanto quanto possível, o efeito das condições ambientais que os ovos de Aedes aegypti são submetidos. Os ovos foram armazenados em três recipientes (copo plástico, saco plástico e envelope de papel) e tratados com água ao final de cada período de armazenamento estabelecido. Por meio do ajuste do modelo linear generalizado binomial com função de ligação logística e preditor linear retas paralelas, foi possível predizer a viabilidade dos ovos de Aedes aegypti. Como medidas da qualidade do ajuste, usou-se o desvio residual com valor de p (nível descritivo), calculado sobre os percentis da distribuição qui-quadrado e o gráfico de probabilidade normal padrão com envelope de simulação. Verificou-se comportamento semelhante entre saco plástico e envelope de papel com respeito a viabilidade estimada dos ovos de Aedes aegypti, ambos diferindo do recipiente copo plástico que apresentou a maior viabilidade. / This work had like objective estimate the time in which the Aedes aegypti eggs remain in hatch conditions and produce viable larvae after remain a certain time (viability) in different storage types. To this, the generalized linear models methodology for data in proportion form was used. As link function was chose the logistic and probit and like linear predictors, parallel and intersecting lines. Was conducted an experiment, in which were simulated as much as possible the effect of environmental conditions in which the Aedes aegypti eggs are submitted. The eggs were stored in three containers (plastic cup, plastic bag and paper envelope) and treated with water at the end of each storage period. With the fit of the binomial generalized linear model with logistic link function and parallel lines like linear predictor, was possible predict the viability of the Aedes aegypti eggs. As quality measures of fit, the residual deviance with p-value (descriptive level), calculated on the chi-square distribution percentiles and the standard normal probability plot with simulated envelope were used. It has been found similar behaviour between plastic bag and paper envelope with respect to estimated viability of the Aedes aegypti eggs, both differing from the plastic cup that presents the highest viability.

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