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Full-Text Articles in Medicine and Health Sciences
Comparison Of Atypical Bacteriophages That Infect Caulobacter Crescentus, Doreen Nguyen
Comparison Of Atypical Bacteriophages That Infect Caulobacter Crescentus, Doreen Nguyen
Theses and Dissertations
Several Caulobacter bacterial genomes have been recently sequenced, and all of the genomes contained one or more clusters of genes with phage origins. This observation indicates that bacteriophages contribute to the Caulobacter gene pool, so in order to understand bacteria genomes we will need to understand phage genomes as well. As part of understanding the phage genomes, we want to isolate novel bacteriophages and study their genomics. This study resulted in the isolation of 12 new phages, including four that differ from the well-studied CbKlike phages. Two of these novel phages are Podoviruses with icosahedral heads and small tails, and …
Marginal Structural Cox Model For Survival Data With Treatment-Confounder Feedback, Yanan Zhang
Marginal Structural Cox Model For Survival Data With Treatment-Confounder Feedback, Yanan Zhang
Theses and Dissertations
In an observational longitudinal study, there can be time-varying exposure/treatment and time-varying confounders. When the confounders affect the exposure and prior exposure also has an impact on levels of confounders, there is treatment confounder feedback. To admit estimation of unbiased causal effects, these conditions need to be hold, exchangeability, positivity, consistency. The traditional method of conditioning on potential confounders does not meet these 3 conditions. Therefore, parameter estimates from traditional Cox model are biased casual effect estimates when the treatment confounder feedback exists. The marginal structural Cox model can be used to address this issue. By calculating and including inverse …