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Full-Text Articles in Physical Sciences and Mathematics
Bayesian Inference On Quantile Regression-Based Mixed-Effects Joint Models For Longitudinal-Survival Data From Aids Studies, Hanze Zhang
USF Tampa Graduate Theses and Dissertations
In HIV/AIDS studies, viral load (the number of copies of HIV-1 RNA) and CD4 cell counts are important biomarkers of the severity of viral infection, disease progression, and treatment evaluation. Recently, joint models, which have the capability on the bias reduction and estimates' efficiency improvement, have been developed to assess the longitudinal process, survival process, and the relationship between them simultaneously. However, the majority of the joint models are based on mean regression, which concentrates only on the mean effect of outcome variable conditional on certain covariates. In fact, in HIV/AIDS research, the mean effect may not always be of …
Statistical Analysis And Modeling Of Stomach Cancer Data, Chao Gao
Statistical Analysis And Modeling Of Stomach Cancer Data, Chao Gao
USF Tampa Graduate Theses and Dissertations
The objective of this study is to address some important questions associated with stomach cancer patients using the data from the Surveillance Epidemiology and End Results (SEER) program of the United States. To better understand the behavior of stomach cancer, we first perform parametric analysis for each patient group (white male, white female, African American male, African American female, other male and female) to identify the probability distribution function which can best characterize the behavior of the malignant stomach tumor sizes. We evaluate the effects of patients’ age, gender and race on the malignant stomach tumor sizes by developing quantile …
A Tail-Based Test For Differential Expression Analysis And Pathway Analysis In Rna-Sequencing Data, Jiong Chen
A Tail-Based Test For Differential Expression Analysis And Pathway Analysis In Rna-Sequencing Data, Jiong Chen
Dissertations & Theses (Open Access)
RNA sequencing data have been abundantly generated in biomedical research for biomarker discovery and pathway analysis. Such data at the exon-level are usually heavily tailed and correlated. Conventional statistical tests based on the mean or median difference for differential expression likely suffer from low power when the between-group difference occurs mostly in the upper or lower tail of the distribution of gene expression. We propose a tail-based test to make comparisons between groups in terms of a specific distribution area rather than a single location. The proposed test, which is derived from quantile regression, adjusts for covariates and accounts for …
Estimating The Effects Of Overstory Retention, Vegetative Competition, And Site Quality On The Height Growth Of Small Ponderosa Pine Trees Using Regression Quantiles, Colin P. Kirkmire
Estimating The Effects Of Overstory Retention, Vegetative Competition, And Site Quality On The Height Growth Of Small Ponderosa Pine Trees Using Regression Quantiles, Colin P. Kirkmire
Graduate Student Theses, Dissertations, & Professional Papers
Ponderosa pine (Pinus ponderosa C. Lawson) forests in the Inland Northwestern region of the US are increasingly managed under multi-aged silvicultural systems that provide stand structure for wildlife habitat, timber production, enhanced aesthetic, or restoration of presettlement conditions (O'Hara 2005). Partial retention harvest, where an element of the previous stand's overstory structure is retained, is commonly used to achieve a multi-aged stand structure. However, little is known about how ponderosa pine trees in the understory respond to overstory and understory competitive factors following partial retention harvest. The height growth of small trees was hypothesized to be influenced by site …