Articles

Likelihood Estimation of Conjugacy Relationships in Linear Models with Applications to High-Throughput Genomics (with Dongmei Liu, Robert B. Scharpf, and Giovanni Parmigiani), The International Journal of Biostatistics (2009)

In the simultaneous estimation of a large number of related quantities, multilevel models provide a...

 

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Characterizing Sleep Structure Using the Hypnogram (with B Swihart, K Bandeen-Roche, and N Punjabi), Journal of Clinical Sleep Medicine (2008)
 

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Fasting Glycemia in Sleep Disordered Breathing: Lowering the Threshold on Oxyhemoglobin Desaturation (with K Stamatakis, M Sanders, H Resnick, D Gottlieb, R Mehra, and N Punjabi), Sleep (2008)
 

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fMRI of intrasubject variability in adhd: Anomalous premotor activity with prefrontal compensation (with S Suskauer, D Simmonds, M Denckla, J Pekar, and S Mostofsky), Journal of American Academy of Child & Adolescent Psychiatry (2008)
 

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Power spectral analysis of EEG activity during sleep in cigarette smokers (with L Zhang, J Samet, I Bankman, and N Punjabi), Chest (2008)
 

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A new method to estimate quantitatively seminal vesicle and prostate gland contributions to ejaculate (with T Ndovi, T Parsons, L Choi, C Rohde, and C Hendrix), British Journal of Clinical Pharmacology (2007)
 

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Are brain volumes based on magnetic resonance imaging mediators of the associations of cumulative lead dose with cognitive function? (with S Chen, W Stewart, K Bolla, D Youssem, C Davatzikos, and B Schwartz), American Journal of Epidemiolgy (2007)
 

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Effect of semen sampling frequency on seminal antiretroviral drug concentration (with Ying Cao, Thomas Ndovi, T Parsons, A Guidos, and Craig Hendrix), Clinical Pharmacology & Therapeutics (2007)
 

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Flexible random intercept models for binary outcomes using mixtures of normals (with M An and C Rohde), Computational Statistics and Data Analysis (2007)
 

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On the potential for ill logic with logically defined outcomes (with Xianbin Li and Daniel Scharfstein), Biostatistics (2007)
 

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Optimal Sampling Times in Bioequivalence Studies Using a Simulated Annealing Algorithm (with Leena Choi and Charles Rohde), Statistics and Computing (2007)
 

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Relations of brain volumes with cognitive function in males 45 years and older with past lead exposure (with B Schwartz, S Chen, W Stewart, K Bolla, D Yousem, and C Davatzikos), Neuroimage (2007)
 

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A user-friendly tutorial on link-probit-normal models (with M Griswold), The American Statistician (2006)
 

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Cigarette smoking and nocturnal sleep architecture (with Lin Zang, Jonathan Samet, and Naresh Punjabi), American Journal of Epidemiology (2006)
 

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Familial risk for Alzheimer’s disease alters fMRI activation patterns (with S Bassett; D Yousem; C Cristinzio,; I Kusevic,; M Yassa; and S Zeger), Brain (2006)
 

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Fixed-width output analysis for Markov chain Monte Carlo (with G Jones, M Haran, and R Neath), Journal of the American Statistical Association (2006)
 

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Ascent-based Monte Carlo EM (with Wolfgang Jank and Galin Jones), Journal of the Royal Statistical Society Series B (2005)
 

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Examples in which misspecification of a random effects distribution reduces efficiency, and possible remedies (with Alan Agresti and Pamela Ohman-Strickland), Computational Statistics and Data Analysis (2004)
 

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Monte Carlo conditional inference for log-linear and logistic models: a survey of current methodology (with James Booth), Statistical Methods in Medical Research (2003)
 

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Empirical Supremum Rejection Sampling (with James G. Booth and Anthony Davison), Biometrika (2002)
 

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Measures of Relative Model Fit (with Alan Agresti), Computational Statistics & Data Analysis (2002)
 

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Unequal Sampling for Monte Carlo EM Algorithms (with James G. Booth), Computational Statistics & Data Analysis (2002)
 

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A Markov Chain Monte Carlo Algorithm for Approximating Exact Conditional Probabilities (with James G. Booth), Journal of Computational and Graphical Statistics (2001)
 

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Multinomial Logit Random Effects Models (with Jonathan Hartzel and Alan Agresti), Statistical Modeling (2001)
 

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Random Effects Modeling of Categorical Response Data (with Alan Agresti, James G. Booth, and James P. Hobert), Sociological Methodology (2000)
 

Technical Reports and Working Papers

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Two-stage Decompositions for the Analysis of Functional Connectivity for fMRI With Application to Alzheimer's Disease Risk (with Ciprian M. Crainiceanu, Guillermo Verduzco, Stewart Mofstovsky, Susan Spear-Bassett, and James J. Pekar), Collection of Biostatistics Research Archive (2009)

Functional connectivity is the study of correlations in measured neurophysiological signals. Altered functional connectivity has...

 

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Lasagna Plots: A Saucy Alternative to Spaghetti Plots (with Bruce Swihart, Bryan D. James, Matthew Strand, Brian S. Schwartz, and Naresh M. Punjabi), Johns Hopkins University, Dept. of Biostatistics Working Papers (2009)

Longitudinal repeated measures data has often been visualized with spaghetti plots for continuous out- comes....

 

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COVARIATE-ADJUSTED NONPARAMETRIC ANALYSIS OF MAGNETIC RESONANCE IMAGES USING MARKOV CHAIN MONTE CARLO (with Haley Hedlin, Ziyad Mahfoud, and Susan Spear Bassett), Johns Hopkins University, Dept. of Biostatistics Working Papers (2009)

Permutation tests are useful for drawing inferences from imaging data because of their flexibility and...

 

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NONLINEAR TUBE-FITTING FOR THE ANALYSIS OF ANATOMICAL AND FUNCTIONAL STRUCTURES (with Jeff Goldsmith, Ciprian Crainiceanu, Daniel Reich, Yong Du, and Craig Hendrix), Johns Hopkins University, Dept. of Biostatistics Working Papers (2009)

We are concerned with the estimation of the exterior surface of tube-shaped anatomical structures. This...

 

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A NOVEL AND SIMPLE RULE OF THUMB FOR MULTIPLICITY CONTROL IN EQUIVALENCE TESTING USING TWO ONE-SIDED TESTS (with Carolyn Lauzon), Johns Hopkins University, Dept. of Biostatistics Working Papers (2008)

Equivalence testing is growing in use in scientific research outside of its traditional role in...

 

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LIKELIHOOD ESTIMATION OF CONJUGACY RELATIONSHIPS IN LINEAR MODELS WITH APPLICATIONS TO HIGH-THROUGHPUT GENOMICS (with Liu Dongmei, Robert Scharpf, and Giovanni Parmigiani), Johns Hopkins University, Dept. of Biostatistics Working Papers (2008)

In the simultaneous estimation of a large number of related quantities, multilevel models provide a...

 

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AN OVERVIEW OF OBSERVATIONAL SLEEP RESEARCH WITH APPLICATION TO SLEEP STAGE TRANSITIONING (with B. Swihart, A. Laffan, C. Crainiceanu, and N. Punjabi), Johns Hopkins University, Dept. of Biostatistics Working Papers (2008)

In this manuscript we give an overview of observational sleep research with a particular emphasis...

 

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JOINTLY MODELING CONTINUOUS AND BINARY OUTCOMES FOR BOOLEAN OUTCOMES: AN APPLICATION TO MODELING HYPERTENSION (with Xianbin Li and Elizabeth Stuart), Johns Hopkins University, Dept. of Biostatistics Working Papers (2008)

Binary outcomes defined by logical (Boolean) "and" or "or" operations on original continuous and discrete...

 

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ON THE MERITS OF VOXEL-BASED MORPHOMETRIC PATH-ANALYSIS FOR INVESTIGATING VOLUMETRIC MEDIATION OF A TOXICANT'S INFLUENCE ON COGNITIVE FUNCTION (with Shu-chih Su, Lynn E. Eberly, Elizabeth Garrett-Mayer, Walter F. Stewart, Sining Chen, David Yousem, Christos Davatzikos, and Brian Schwartz), Johns Hopkins University, Dept. of Biostatistics Working Papers (2008)

We previously showed that lifetime cumulative lead dose, measured as lead concentration in the tibia...

 

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A CASE STUDY IN PHARMACOLOGIC IMAGING USING PRINCIPAL CURVES IN SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (with Ciprian M. Crainiceanu, Lijuan Deng, and Craig W. Hendrix), Johns Hopkins University, Dept. of Biostatistics Working Papers (2007)

In this manuscript we are concerned with functional imaging of the colon to assess the...

 

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IS MRI-BASED VOLUME A MEDIATOR OF THE ASSOCIATION OF CUMULATIVE LEAD DOSE WITH COGNITIVE FUNCTION? (with Sining Chen, Walter Stewart, Karen Bolla, David Yousem, Christos Davatzikos, and Brian S. Schwartz), Johns Hopkins University, Dept. of Biostatistics Working Papers (2007)

This work considers the pathway through which past occupational lead exposure impacts cognitive function using...

 

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A BAYESIAN HIERARCHICAL FRAMEWORK FOR SPATIAL MODELING OF fMRI DATA (with F. DuBois Bowman, Susan Spear Bassett, and Clinton Kilts), Johns Hopkins University, Dept. of Biostatistics Working Papers (2007)

Functional neuroimaging techniques enable investigations into the neural basis of human cognition, emotions, and behaviors....

 

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MODIFIED TEST STATISTICS BY INTER-VOXEL VARIANCE SHRINKAGE WITH AN APPLICATION TO fMRI (with Shu-chih Su, Elizabeth Garrett-Mayer, and Susan Bassett), Johns Hopkins University, Dept. of Biostatistics Working Papers (2007)

Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique which is commonly used to quantify...

 

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A SURVEY OF THE LIKELIHOOD APPROACH TO BIOEQUIVALENCE TRIALS (with Leena Choi and Charles Rohde), Johns Hopkins University, Dept. of Biostatistics Working Papers (2007)

Bioequivalence trials are abbreviated clinical trials whereby a generic drug or new formulation is evaluated...

 

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A Flexible and General Class of Marginal and Conditional Random Intercept Models for Binary Outcomes Using Mixtures of Normals (with Ming-Wen An and Charles A. Rohde), Johns Hopkins University, Dept. of Biostatistics Working Papers (2006)

Random intercept models for binary data are useful tools for addressing between subject heterogeneity. Unlike...

 

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On the Potential For Ill-logic with Logically Defined Outcomes (with Xianbin Li and Daniel O. Scharfstein), Johns Hopkins University, Dept. of Biostatistics Working Papers (2006)

Logically defined outcomes are commonly used in medical diagnoses and epidemiological research. When missing values...

 

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A User-Friendly Introduction to Link-Probit-Normal Models (with Michael Griswold), Johns Hopkins University, Dept. of Biostatistics Working Papers (2005)

Probit-normal models have attractive properties compared to logit-normal models. In particular, they allow for easy...

 

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A Mechanistic Latent Variable Model for Estimating Drug Concentrations in the Male Genital Tract (with Leena Choi, Charles A. Rohde, Themba T. Ndovi, and Craig W. Hendrix), Johns Hopkins University, Dept. of Biostatistics Working Papers (2005)

The purpose of this study is to develop statistical methodology to facilitate indirect estimation of...

 

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Fixed-Width Output Analysis for Markov Chain Monte Carlo (with Galin L. Jones, Murali Haran, and Ronald Neath), Johns Hopkins University, Dept. of Biostatistics Working Papers (2005)

Markov chain Monte Carlo is a method of producing a correlated sample in order to...

 

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Optimal Sampling Times in Bioequivalence Studies Using a Simulated Annealing Algorithm (with Leena Choi and Charles Rohde), Johns Hopkins University, Dept. of Biostatistics Working Papers (2004)

In pharmacokinetic (PK) studies, blood samples are taken over time on subjects after the administration...

 

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Screening for Differentially Expressed Genes: Are Multilevel Models Helpful? (with Dongmei Liu and Giovanni Parmigiani), Johns Hopkins University, Dept. of Biostatistics Working Papers (2004)

Screening for changes in gene expression across biological conditions using microarrays is now a common...