Physical Sciences and Mathematics Commons^™

Estimation Of Hiv Incidence Using Multiple Biomakers, Ron Brookmeyer, Jacob Konikoff, Oliver Laeyendecker, Susan Eshleman

Ron Brookmeyer

The incidence of human immunodeficiency virus (HIV) is the rate at which new HIV infections occur in populations. The development of accurate, practical, and cost-effective approaches to estimation of HIV incidence is a priority among researchers in HIV surveillance because of limitations with existing methods. In this paper, we develop methods for estimating HIV incidence rates using multiple biomarkers in biological samples collected from a cross-sectional survey. An advantage of the method is that it does not require longitudinal follow-up of individuals. We use assays for BED, avidity, viral load, and CD4 cell count data from clade B samples collected …

Inhibition Of Bacillus Cereus Growth By Bacteriocin Producing Bacillus Subtilis Isolated From Fermented Baobab Seeds (Maari) Is Substrate Dependent, Donatien Kaboré, Dennis S. Nielsen, Hagrétoui Sawadogo-Lingan, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jakobsen, Line Thorsen

Pr. Mamoudou H. DICKO, PhD

Improved Cardiovascular Risk Prediction Using Nonparametric Regression And Electronic Health Record Data, Edward Kennedy, Wyndy Wiitala, Rodney Hayward, Jeremy Sussman

Edward H. Kennedy

Use of the electronic health record (EHR) is expected to increase rapidly in the near future, yet little research exists on whether analyzing internal EHR data using flexible, adaptive statistical methods could improve clinical risk prediction. Extensive implementation of EHR in the Veterans Health Administration provides an opportunity for exploration. Our objective was to compare the performance of various approaches for predicting risk of cerebrovascular and cardiovascular (CCV) death, using traditional risk predictors versus more comprehensive EHR data. Regression methods outperformed the Framingham risk score, even with the same predictors (AUC increased from 71% to 73% and calibration also improved). …

Hyaluronic Acid Based Self-Assembling Nanosystems For Cd44 Target Mediated Sirna Delivery To Solid Tumors., Arun Iyer

Arun Iyer

Anticancer therapeutics employing RNA interference mechanism holds promising potentials for sequence-specific silencing of target genes. However targeted delivery of siRNAs to tumor tissues and cells and more importantly, their intracellular release at sites of interest still remains a major challenge that needs to be addressed before this technique could become a clinically viable option. In the current study, we have engineered and screened a series of CD44 targeting hyaluronic acid (HA) based self-assembling nanosystems for targeted siRNA delivery. The HA polymer was functionalized with lipids of varying carbon chain lengths/nitrogen content, as well as polyamines for assessing siRNA encapsulation. From …

A Case-Control Study Of Physical Activity Patterns And Risk Of Non-Fatal Myocardial Infarction, Jian Gong, Hannia Campos, Mark Fiecas, Stephen Mcgarvey, Robert Goldberg, Caroline Richardson, Ana Baylin

Mark Fiecas

Background The interactive effects of different types of physical activity on cardiovascular disease (CVD) risk have not been fully considered in previous studies. We aimed to identify physical activity patterns that take into account combinations of physical activities and examine the association between derived physical activity patterns and risk of acute myocardial infarction (AMI). Methods We examined the relationship between physical activity patterns, identified by principal component analysis (PCA), and AMI risk in a case-control study of myocardial infarction in Costa Rica (N=4172), 1994-2004. The component scores derived from PCA and total METS were used in natural cubic spline models …

Hydraphiles: A Rigorously Studied Class Of Synthetic Channel Compounds With In Vivo Activity, Saeedeh Negin, Bryan A. Smith, Alexandra Unger, W. Matthew Leevy, George W. Gokel

George Gokel

No abstract provided.

Varying-Smoother Models For Functional Responses, Philip T. Reiss, Lei Huang, Huaihou Chen, Stan Colcombe

Philip T. Reiss

This paper studies estimation of a smooth function f(x,v) when we are given functional responses of the form f(x, ·) + error, but scientific interest centers on the collection of functions f(·,v) for different v. The motivation comes from studies of human brain development, in which x denotes age whereas v refers to brain locations. Analogously to varying-coefficient models, in which the mean response is linear in x, the “varying-smoother” models that we consider exhibit nonlinear dependence on x that varies smoothly with v. We discuss three approaches to estimating varying-smoother models: (a) methods that employ a tensor product penalty; …

Progression From New Methicillin-Resistant Staphylococcus Aureus Colonisation To Infection: An Observational Study In A Hospital Cohort, Michelle Nd Balm, Andrew A. Lover, Sharon Salmon, Paul A. Tambyah, Dale A. Fisher

Andrew Lover

Quantifying Effect Of Geographic Location On Epidemiology Of Plasmodium Vivax Malaria, Andrew A. Lover, Richard J. Coker

Andrew Lover

Methods For Evaluating Prediction Performance Of Biomarkers And Tests, Margaret S. Pepe Phd, Holly Janes Phd

Margaret S Pepe PhD

This chapter describes and critiques methods for evaluating the performance of markers to predict risk of a current or future clinical outcome. We consider three criteria that are important for evaluating a risk model: calibration, benefit for decision making and accurate classification. We also describe and discuss a variety of summary measures in common use for quantifying predictive information such as the area under the ROC curve and R-squared. The roles and problems with recently proposed risk reclassification approaches are discussed in detail.