Physical Sciences and Mathematics Commons^™

A Bayesian Model For Pooling Gene Expression Studies That Incorporates Co-Regulation Information, Erin Conlon, Bradley L. Postier, Barbara Methé, Kelly Nevin, Derek Lovley

Microbiology Department Faculty Publication Series

Current Bayesian microarray models that pool multiple studies assume gene expression is independent of other genes. However, in prokaryotic organisms, genes are arranged in units that are co-regulated (called operons). Here, we introduce a new Bayesian model for pooling gene expression studies that incorporates operon information into the model. Our Bayesian model borrows information from other genes within the same operon to improve estimation of gene expression. The model produces the gene-specific posterior probability of differential expression, which is the basis for inference. We found in simulations and in biological studies that incorporating co-regulation information improves upon the independence model. …

Spatial And Temporal Correlations Of Freeway Link Speeds: An Empirical Study, Piotr J. Rachtan

Masters Theses 1911 - February 2014

Congestion on roadways and high level of uncertainty of traffic conditions are major considerations for trip planning. The purpose of this research is to investigate the characteristics and patterns of spatial and temporal correlations and also to detect other variables that affect correlation in a freeway setting. 5-minute speed aggregates from the Performance Measurement System (PeMS) database are obtained for two directions of an urban freeway – I-10 between Santa Monica and Los Angeles, California. Observations are for all non-holiday weekdays between January 1st and June 30th, 2010. Other variables include traffic flow, ramp locations, number of lanes and the …

Childhood Body Mass Index Trajectories: Modeling, Characterizing, Pairwise Correlations And Socio-Demographic Predictors Of Trajectory Characteristics, Xiaozhong Wen, Ken Kleinman, Matthew W. Gillman, Sherly L. Rifas-Shiman, Elsie M. Taveras

Public Health Department Faculty Publication Series

BACKGROUND:

Modeling childhood body mass index (BMI) trajectories, versus estimating change in BMI between specific ages, may improve prediction of later body-size-related outcomes. Prior studies of BMI trajectories are limited by restricted age periods and insufficient use of trajectory information.

METHODS:

Among 3,289 children seen at 81,550 pediatric well-child visits from infancy to 18 years between 1980 and 2008, we fit individual BMI trajectories using mixed effect models with fractional polynomial functions. From each child's fitted trajectory, we estimated age and BMI at infancy peak and adiposity rebound, and velocity and area under curve between 1 week, infancy peak, adiposity …

Estimation Of Newborn Risk For Child Or Adolescent Obesity:Lessons From Longitudinal Birth Cohorts, Anita Morandi, David Meyre, Stephane Lobbens, Ken Kleinman, Marika Kaakinen, Sheryl L. Rifas-Shiman, Vincent Vatin, Stefan Gaget, Anneli Pouta, Anna-Liisa Hartikainen, Jaana Laitinen, Matthew W. Gillman, Marjo-Riitta Jarvelin, Philippe Froguel

Public Health Department Faculty Publication Series

OBJECTIVES:

Prevention of obesity should start as early as possible after birth. We aimed to build clinically useful equations estimating the risk of later obesity in newborns, as a first step towards focused early prevention against the global obesity epidemic.

METHODS:

We analyzed the lifetime Northern Finland Birth Cohort 1986 (NFBC1986) (N = 4,032) to draw predictive equations for childhood and adolescent obesity from traditional risk factors (parental BMI, birth weight, maternal gestational weight gain, behaviour and social indicators), and a genetic score built from 39 BMI/obesity-associated polymorphisms. We performed validation analyses in a retrospective cohort of 1,503 Italian children …