CURRICULUM VITAE

Aiyi Liu, PhD

HOME ADDRESS 1844 Lusby Place, Falls Church, VA 22043
TELEPHONE (W) (301) 435-6952       (301) 825-2245
(H) (703) 455-0023       (C) (571) 345-4534
EMAILS liua@mail.nih.gov   aiyiliu65@gmail.com   aiyiliu@gwu.edu

EDUCATION AND TRAINING

B.S. in Mathematics (Statistics Major), July 1986; M.S. in Statistics, June 1988; Department of Mathematics, University of Science and Technology of China, Hefei, Anhui, China

Ph.D. in Statistics, October 1997, Department of Statistics, University of Rochester, Rochester, NY, U.S.A.

Postdoctoral Research Fellow, August 1997-March 1999, Department of Biostatistics and Epidemiology, St. Jude Children’s Research Hospital, Memphis, TN, U.S.A.

CURRENT POSITION

May 2007-Present Senior Investigator (with Tenure)
Biostatistics and Bioinformatics Branch
Division of Intramural Population Health Research
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health

PAST ACADEMIC APPOINTMENT

Investigator (Tenure Track), February 2002-May 2007, Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health

Assistant Professor of Biostatistics, March 1999-February 2002; Adjunct Associate Professor of Biostatistics, April 2004-2006; Department of Biostatistics and Bioinformatics, and Lombardi Cancer Center, Georgetown University Medical Center

Assistant Professor of Statistics, September 1988-July 1993, Department of Mathematics, University of Science and Technology of China

MEMBERSHIP IN PROFESSIONAL SOCIETIES

American Statistical Association, International Biometric Society (ENAR), International Chinese Statistical Association, International Indian Statistical Association, International Statistical Institute, Institute of Mathematical Statistics, and Korean International Statistical Society

HONORS AND AWARDS

Jiuzhang Mathematical Prize, University of Science and Technology of China, 1991

Graduate Fellowships, University of Rochester, 1993-1997

Time-Off Award in Recognition and Appreciation of Special Act or Service, NICHD, NIH, 2002

Elected member, International Statistical Institute, 2006

National Institutes of Health Merit Award, 2007, 2009

Fellow, American Statistical Association, 2011

National Institutes of Health Director’s Award, 2013

PROFESSIONAL SERVICE

Associate Editor, Clinical Trials: Journal of the Society for Clinical Trials, 2014-Present

Member, Committee on Award of an Outstanding Statistical Application, the American Statistical Association (ASA), 2011-Present

Chair, Program Committee and Executive Committee, International Chinese Statistical Association 2013 Applied Statistics Symposium

Member, Program Committee, International Chinese Statistical Association 2011 Applied Statistics Symposium

Editorial Board, Open Journal of Genetics, 2011-Present

Editorial Board, Journal of Biometrics & Biostatistics, 2010-Present

Associate Editor, Journal of Statistical Planning and Inference, 2009-2012.

Member, Planning Committee, International Chinese Statistical Association 2005 Applied Statistics Symposium

Session organizer and chair on “Pooling Biospecimens: Methodologies, Applications and Limitations”. International Chinese Statistical Association Applied Statistics Symposium, Washington, DC, June 2005

Session organizer and chair on “Sequential Methods for Evaluation of Diagnostic Biomarkers”. International Chinese Statistical Association Applied Statistics Symposium, University of Connecticut, June 2006

Member, Board of Directors, International Chinese Statistical Association, 2007-2009

Short course instructor on “Sequential Statistical Methods in the Design and Analysis of Clinical Trials”, at The 15th International Conference on Interdisciplinary Mathematical and Statistical Techniques, Shanghai, China, June 2007

Session organizer on “Dealing with Measurements Subject to Limits of Detection in Epidemiology Studies”. International Chinese Statistical Association Applied Statistics Symposium, Raleigh, NC, June 2007

Guest Editor for “Mathematical and Statistical Methods for Diagnoses and Therapies”. Philosophical Transaction of the Royal Society A, Number 1874, Volume 366, July 2008

Session chair on “Adaptive designs: Perspectives from academia, industry and regulatory”. International Biometric Society (ENAR) Spring Meeting, Washington, DC, March 2008

Peer referee for American Journal of Epidemiology, Biometrics, Biometrika, Biostatistics, Cancer Research, Communications in Statistics, Controlled Clinical Trials, Computational Statistics & Data Analysis, Epidemiology, Journal of Biopharmaceutical Statistics, Journal of Statistical Planning and Inference, Journal of the American Statistical Association, Journal of Multivariate Analysis, Medical and Pediatric Oncology, Pharmacotherapy, Statistics in Biopharmaceutical Research, Statistics in Medicine, Statistics and Probability Letters, Statistica Sinica

RESEARCH INTEREST

General statistical theory and methods

Sequential and adaptive methods in clinical trials and biomedical research

Multivariate data analysis and related topics

Statistical methodology for diagnostic biomarkers (ROC curve analysis; methods for pooled biospecimens; evaluation of measurement errors; limit of detection and left truncation)

Semiparametric and nonparametric methods for multidimensional data

Genome-wide association studies

Group testing methodology

TEACHING, TRAINING AND MENTORING

Teaching various undergraduate and graduate statistics courses, including Statistics for Biological Sciences, Linear Models and its Applications, Regression Analysis. Department of Mathematics, University of Science and Technology of China, August 1988-July 1993

Teaching Assistant in various undergraduate statistics courses. University of Rochester, Department of Statistics, September 1993-August 1997

Teaching in the MS program of biostatistics in the Department of Biostatistics and Epidemiology of Georgetown University Medical Center, participating lecture series for staff and postdoctoral fellows in the Department of Oncology and Lombardi Cancer Center, March 1999-February 2002. Teaching Applied Biostatistics (19 students, 4 classes), January –February 2002

Teaching “Applied Multivariate Statistical Analysis” (Stat6215, graduate level), Fall 2011. Department of Statistics, George Washington University

Teaching “Clinical Trials” (STAT6289-13, graduate level), Spring 2012. Department of Statistics, George Washington University

Teaching “Regression Analysis” (STAT2118, graduate level), Spring 2013, Fall 2013. Department of Statistics, George Washington University

Co-Mentor (with Enrique Schisterman) to summer students at NICHD: Eric Teoh (University of Alabama), 2002; Howard Bondell (Rutgers University), Neil Perkins (American University), 2003

Mentor to summer interns at NICHD: Yan Zhu (University of Virginia), 2003; Helen Guo (Thomas Jefferson High School for Science and Technology), 2004; Elizabeth Schofield Dahlquist (University of South Florida), 2005; Ekaterina Eliseeva (University of Chicago), 2006; Helen Guo (University of Virginia), 2007; Xiaoshu Feng (University of Maryland), 2008, Angel Davalos (University of Texas-El Paso), 2009; Robert Ashmead (The Ohio State University), 2011

Mentor to postdoctoral fellows at NICHD: Chengqing Wu (University of Science and Technology of China), October 2003-October 2007; Albert Vexler (Hebrew University), June 2004-June 2007; Catherine Chunling Liu (University of Hong Kong), October 2008-July 2010

Ph.D. thesis co-advisor (with Professor Zhaohai Li) to Yu Shu, Department of Statistics, George Washington University. Thesis title: “Group sequential designs and inference of a medical diagnostic test with binary outcomes.”

Ph.D. thesis co-advisor (with Professor Zhaohai Li) to Mei Jin, Department of Statistics, George Washington University

Ph.D. thesis co-advisor (with Professor Zhaohai Li) to Xian Sun, Department of Statistics, George Washington University

Ph.D. thesis co-advisor (with Professor Daniel Q. Naiman) to Jiang Hu, Department of Applied Mathematics and Statistics, the Johns Hopkins University. Thesis title: “Sequential design and terminal analysis of multinomial data.”

SERVICES AT NIH

Committee on Division of Intramural Population Health Research Retreat, 2002

Search Committee for Staff Scientist, Division of Intramural Population Health Research, 2003

Ph.D. Thesis Committee for Jiaquan Fan, Department of Statistics, George Washington University, March 2004

Ph.D. Thesis Committee for Dennis Buckman, Department of Statistics, George Washington University, June 2005

Judge for the Fellows Award for Research Excellence (FARE) 2005, Gene Expression Section

Search Committee for Statistician Staff Scientist – Facility Head Recruitment, Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, 2005, 2006

Search Committee member for tenure-track/tenured investigator, Epidemiology Branch, Division of Intramural Population Health Research, 2006

Data Safety and Monitoring Board (DSMB) for “S.japonicum and Pregnancy Outcomes: A Randomized, Double Blind, Placebo Controlled Trial”, National Institute of Allergy and Infectious Diseases (NIAID), 2006-Present

Ad hoc Reviewer, National Institute on Aging Board of Scientific Counselors’ (BSC) Meeting, May, 2008

Member, Search Committee for Tenure-Track Investigators, Division of Intramural Population Health Research, 2009

Member, Search Committee for Tenure-Track/Tenure-Eligible Investigators, Division of Intramural Population Health Research, 2010

Member, Professional Development Committee, Division of Intramural Population Health Research, 2010

Member, Institutional Review Board (IRB), National Institute of Child Health and Human Development, 2011-Present

Member, Search Committee for Tenure-Track/Tenure-Eligible Investigators, Division of Intramural Population Health Research, 2012

Ad hoc Reviewer, National Institute on Aging Board of Scientific Counselors’ (BSC) Meeting, May, 2012

Member, Search Committee for Staff Scientist, Division of Intramural Population Health Research, 2013

Member, Mentoring Committee, Division of Intramural Population Health Research, 2013

INVITED PRESENTATIONS

“Secondary analysis following sequential clinical trials”. Western Tennessee Chapter of ASA, Memphis, TN, April 1998

“Sequential tests and estimates after overrunning”. Statistical Research Symposium in Honor of W. Jackson Hall’s 70th Birthday. University of Rochester, Rochester, NY, September 1999

“Molecular classification of stage I breast cancer using gene microarray technology”. International Chinese Statistical Association Applied Statistics Symposium, Piscataway, NJ, June 1999

“Sample size calculation for planning group sequential longitudinal trials”. CDER, Food and Drug Administration (FDA), Rockville, MD, March 2000

“Analyzing data from a sequential clinical trial”. Workshop on Current Advances in Interim Analysis and Design Modifications, CDER, Food and Drug Administration (FDA), Rockville, MD, September 2000

“Block principal component analysis with application to gene microarray data classification”. Office of Biostatistics Research, National Heart Lung and Blood Institute, April 2003

“Unbiased estimation following a group sequential test for distributions in the exponential family”. Department of Mathematics and Statistics, York University, Canada, November 2003

“Estimation following a multivariate group sequential test”. International Chinese Statistical Association Applied Statistics Symposium, San Diego, CA, June 2004

“On linear combinations of biomarkers to improve diagnostic accuracy”. Department of Epidemiology and Biostatistics, Medical University of South Carolina, September 2004

“On linear combinations of biomarkers to improve diagnostic accuracy”. Division of Cancer Epidemiology and Genetics, National Cancer Institute, January 2005

“Estimation following a group sequential test for distributions in the one-parameter exponential family”. Department of Mathematics, University of Maryland, February 2005

“Local maximization of linear combination of biomarkers to improve diagnostic accuracy”. International Chinese Statistical Association Applied Statistics Symposium, Washington, DC, June 2005

“Sequential evaluation of time varying, non-transient treatment effects in clinical trials”. International Biometric Society –WNAR/IMS Meeting, Fairbanks, Alaska, June 2005

“Estimation following a group sequential test for distributions in the one-parameter exponential family”. Department of Statistics, George Washington University, September 2005

“Estimating rates at the termination of a group sequential phase II trial”. Department of Statistics, University of Virginia, October 2005

“Estimation following a group sequential test for distributions in the one-parameter exponential family”. Department of Mathematics and Statistics, McMaster University, Canada, February 2006

“Non-parametric sequential testing of the area under the ROC curves”. International Biometric Society (ENAR) Spring Meeting, Tampa, FL, March 2006

“Multistage evaluation of measurement error in a reliability study”. International Chinese Statistical Association Applied Statistics Symposium, University of Connecticut, June 2006

“Multistage evaluation of measurement error in a reliability study”. Department of Applied Mathematics, Beijing University of Technology, China, July 2006

“Multistage evaluation of measurement error in a reliability study”. Department of Statistics, George Mason University, October 2006

“Multistage evaluation of measurement error in a reliability study”. Department of Biostatistics, Columbia University, February 2007

“An adaptive approach for bivariate phase II clinical trial designs”. The 15th International Conference on Interdisciplinary Mathematical and Statistical Techniques, Shanghai, China, June 2007

“Sequential methods for evaluation of medical tests” (Invited Plenary Speech). The 15th International Conference on Interdisciplinary Mathematical and Statistical Techniques, Shanghai, China, June 2007

“Sample Size for a logistic regression with a covariate subject to detection limit”. International Chinese Statistical Association Applied Statistics Symposium, Raleigh, NC, June 2007

“A two-stage procedure for selecting the best diagnostic biomarker with dichotomous outcomes”. The First International Workshop in Sequential Methodologies, Auburn, Alabama, July 2007

“An adaptive approach for testing two correlated proportions with application to bivariate phase II clinical trial designs”. Department of Biostatistics, State University of New York at Buffalo, September 2007

“Sequential evaluation of measurement error in a reliability study”. Department of Biostatistics and Computational Biology, University of Rochester, NY, November, 2007

“A threshold sample-enrichment approach in a clinical trial with heterogeneous subpopulations”. Division of Biostatistics, University of Maryland School of Medicine, Baltimore, MD, May 2008

“Sequential evaluation of measurement error in a reliability study”. International Chinese Statistical Association Applied Statistics Symposium, Piscataway, NJ, June 2008

“Two-stage procedures in statistical experiments and analysis”. Department of Mathematics and Statistics, University of South Alabama, Mobile, October 2008

“A threshold sample-enrichment approach in a clinical trial with heterogeneous subpopulations”. Symposium in Honor of Dr. Edmund Gehan, Georgetown University Medical Center, Washington, DC, April 27, 2009

“Threshold sample enrichment approach with heterogeneous populations in a clinical trial for preeclampsia”. University of Pennsylvania Conference on Statistical Issues in Clinical Trials: From Bench to Bedside to Community, Philadelphia, PA, April 29, 2009

“An efficient rank-based test for comparison of multidimensional outcomes”. International Chinese Statistical Association Applied Statistics Symposium, San Francisco, CA, June 2009

“A threshold sample-enrichment approach in a clinical trial with heterogeneous subpopulations”. International Biometric Society (ENAR) Spring Meeting, New Orleans, LA, March, 2010

“A rank-based test for comparison of multidimensional outcomes”. Department of Biostatistics and Bioinformatics, Duke University. April 2010

“A min-max combination of biomarkers to improve diagnostic accuracy”. First Joint Biostatistics symposium, Beijing, China, July 2010

“Optimality of group testing in the presence of misclassification”. International Workshop on the Frontier of Statistics, Beijing, China, July 2010

“Using group testing to evaluate gene-environment interaction”. International Chinese Statistical Association Applied Statistics Symposium, New York City, NY, June 2011

“Optimality of group testing in the presence of misclassification”. Department of Statistics, Pennsylvania State University, September 2011

“A nonparametric procedure to compare clustered multiple endpoints”. Department of Mathematics and Statistics, University of Maryland at Baltimore County, Baltimore, MD, October 2011

“Combining biomarkers to improve diagnostic accuracy”. International Biometric Society (ENAR) Spring Meeting, Washington, DC, April 2012

“Adjusting for misclassification in stratified biomarker clinical trials”. Department of Biostatistics and Bioinformatics, Duke University, May 2012

“Optimality of group testing in the presence of misclassification”. International Chinese Statistical Association Applied Statistics Symposium, Boston, June 2012

“From diagnostic biomarkers to innovative clinical trials-A statistician’s perspective”. Division of Biostatistics, UMD Marlene and Stewart Greenebaum Cancer Center, April 2013

“Some statistical challenges in the design and analysis of gestational diabetes studies”. Joint Statistical Meetings, Montreal, Canada, August 2013

“A nonparametric procedure to compare clustered multiple endpoints”. Department of Biostatistics-SLAM Working Group, Johns Hopkins University, September 2013

CONTRIBUTED PRESENTATIONS

“Uniformly minimum variance unbiased estimation of the drift of Brownian motion with parallel or triangular stopping boundaries.” International Chinese Statistical Association Applied Statistics Symposium, Baltimore, MD, June 1996

“Uniformly minimum variance unbiased estimation of the drift of Brownian motion with parallel or triangular stopping boundaries.” Joint Statistical Meetings, Chicago, IL, August 1996

“Unbiased estimation following sequential tests”. International Biometric Society (ENAR) Spring Meeting, Memphis, TN, March 1997

“Two simple estimates following a sequential test”. International Biometric Society (ENAR) Spring Meeting, Pittsburgh, PA, March 1998

“Sequential tests and estimates after overrunning”. Joint Statistical Meetings, Baltimore, MD, August 1999

“Analysis of secondary endpoints following sequential clinical trials”. International Biometric Society (ENAR) Spring Meeting, Atlanta, GA, March 1999

“Analysis of secondary endpoints following sequential clinical trials”. International Chinese Statistical Association Applied Statistics Symposium, Washington, DC, June 1999

“Sample size and power determination for clustered repeated measurements”. International Biometric Society (ENAR) Spring Meeting, Chicago, IL, March 2000

“Visualization of gene microarray data using block principal component analysis”. International Biometric Society (ENAR) Spring Meeting, Charlotte, NC, March 2001

“Visualization of gene microarray data using block principal component analysis”. National Cancer Institute SPORE Microarray Workshop on Informatics, San Francisco, CA, June 2001

“Nonparametric inference on the partial area under receiver operating characteristic curves”. Mid-Atlantic Probability and Statistics Day, George Washington University, Washington, DC, November 2002

“Conditional receiver operating characteristic curves for evaluation of diagnostic accuracy in matched case-control studies”. The 2nd International Biometric Society Conference of the Eastern Mediterranean Region (EMR), Antalya, Turkey, January 2003

“Design and analysis of comparative diagnostic accuracy studies with multiple correlated test results”. International Biometric Society (ENAR) Spring Meeting, Tampa, FL, March 2003

“Conditional receiver operating characteristic curves for evaluation of diagnostic accuracy with clustered data”. Joint Statistical Meetings, San Francisco, CA, August 2003

“Unbiased estimation following a group sequential test for distributions in the exponential family”. Joint Statistical Meetings, Toronto, Canada, August 2004

“Estimating rates in a multistage phase II trial” (poster presentation). National Institutes of Health Research Festival, September 2004

“Supplementary analysis of probabilities at the termination of a group sequential phase II trial”. International Biometric Society (ENAR) Spring Meeting, Austin, TX, March 2005

“Multistage evaluation of measurement error in a reliability study” (poster presentation). National Institutes of Health Research Festival, October 2005

“Multistage evaluation of measurement error in a reliability study”. International Conference on Design and Experiments, Tianjin, China, July 2006

“Nonparametric procedures for comparing correlated multiple endpoints with applications to oxidative stress biomarkers”. International Biometric Society (ENAR) Spring Meeting, San Antonio, TX, March 2009

“Two-stage procedures for selecting the best diagnostic biomarkers” (Topic Contributed). Joint Statistical Meetings, Washington, DC, August 2009

“A Nonparametric Procedure to Compare Clustered Multiple Endpoints”. 7th International Conference on Multiple Comparison Procedures (MCP), Washington, DC, August 2011

“Adjusting for misclassification in stratified biomarker clinical trials”. (Topic-Contributed) Joint Statistical Meeting, San Diego, CA, August 2012.

PAST COLLABORATIVE RESEARCH PRIOR TO NIH

University of Rochester Medical Center (September 1993-July 1997)

Research Associate (June 1997-July 1998) and Consultant (August 1998-June 2000) on “Secondary inference in cardiovascular clinical trials” (NIH/R01 HL58751), NHLBI (July 1, 1997 to June 30, 2000). Principal Investigator: W. Jack Hall, Department of Biostatistics

St. Jude Children’s Research Hospital (August 1997-March 1999)

Co-Investigator on “Nutrient intakes of hospitalized pediatric patients on oncology services: A comparison of patients dinning with caregivers versus patients dinning independently”. Principal Investigator: Ruth Williams, Department of Clinical Nutrition

Co-Investigator on “Nutritional, clinical and biological effects of glutamine supplementation in children with sickle cell disease”. Principal Investigator: Ruth Williams, Department of Clinical Nutrition

Georgetown University Lombardi Cancer Center (March 1999-Februray 2002)

Biostatistics Core Grant (30%) on “Cancer center support grant” (NIH/5P30 CA51008, $1,653,617), NCI (May 1, 1997-April 30, 2002). Principal Investigator: Marc Lippman

Co-Investigator (5%) on “Breast cancer center grant” (CC950002, $1,200,038), DOD (July 1, 1996-June 30, 2000). Principal Investigator: Marc Lippman

Co-Investigator (5%) on “PKC modulation in patients with advanced cancer” (NIH/R01 CA71856, $123,000), NCI (July 1, 1996-June 30, 2000). Principal Investigator: John Marshall

Co-Investigator (5%) on “Health promotion for women at risk for breast cancer” (NIH/R01 CA74869, $74,307), NCI (August 1, 1998-May 5, 2003). Principal Investigator: Janet Audrain

Co-Investigator (5% in years 1-2 and 10% in years 3-5) on “Transdisciplinary Tobacco Use Research Center (TTURC)” (NIH/1p50 CA84718-01, $2,207,020), NCI (September 30, 1999-September 29, 2004). Principal Investigator: Caryn Lerman

Co-Investigator (5%) on “Genetic counseling for breast cancer susceptibility in African American women”, DOD (July 2000-June 2005). Principal Investigator: Chanita Hughes

Co-Investigator (5%) on “Anticancer therapeutic potential of VEGI, an antiangiogenic cytokine”, DOD (March 2001-February 2004). Principal Investigator: Luyuan Li

Co-Investigator (5%) on “Polymorphic polyglutamine of A1B1 and its relationship to breast cancer”, DOD (March 2001-February 2004). Principal Investigator: Lee-Jun Wong

Co-Investigator (5%) on “Mitochondrial DNA mutations in breast cancer”, DOD (March 2001-February 2004). Principal Investigator: Lee-Jun Wong

Co-investigator (20% in year three) on “Mutagen sensitivity, apoptosis, and polymorphism in DNA repair as measures of prostate cancer risk”, DOD (November 2001-October 2004). Principal Investigator: Radoslav Goldman

MAJOR COLLABORATIVE STUDIES AT NICHD

Family Management of Diabetes Multisite Main Trial (FMOD)

Cultivating Healthy Environments in Families with Type 1 Diabetes (CHEF)

Trinity Students Study (TSS)

Genetic Factors in Birth Defects

Diabetes & Women’s Health: A Study of Long-Term Health Implications of Glucose Intolerance in Pregnancy (DWH)

Diet, Weight Change and Obesity in Pregnancy Study (DWOP)

PEER-REVIEWED RESEARCH ARTICLES

  1. Liu A. (1988). On the best estimation of variance in linear models. Mathematical Statistics and Applied Probability 3: 232-236
  2. Wang S, Liu A. (1989). Relative efficiency of two-stage estimators. Acta Mathematica Sinica 32: 42-54
  3. Liu A, Wang S. (1989). A new relative efficiency of least squares estimates in linear models. Chinese Journal of Applied Probability and Statistics 5: 97-104
  4. Liu A, Wang, S. (1991). Biased estimators for the parameters of a class of related regression system. Chinese Journal of Applied Probability and Statistics 7: 266-274
  5. Liu A. (1993). An improvement of principal components estimator for seemingly unrelated regression equations. Mathematical Statistics and Applied Probability 8: 70-75
  6. Liu A. (1993). An efficient estimation of seemingly unrelated multivariate regression models with application to growth curves analysis. Statistica Sinica 3: 421-434
  7. Liu A. (1994). Selection of covariates and estimation of parameters in growth curve models. Acta Mathematica Sinica 37: 362-372
  8. Liu A. (1996). Estimation of the parameters in two linear models with only some of the parameter vectors identical. Statistics and Probability Letters 29: 369-375
  9. Liu A. (1997). On the maximum likelihood estimate for the drift of Brownian motion following a symmetric sequential probability ratio test. Communications in Statistics---Theory and Methods 26: 977-989
  10. Liu A. (1998). Detecting influential covariates in a growth curve model. Computational Statistics and Data Analysis 28: 105-113
  11. Liu A, Hall WJ. (1998). Minimum variance unbiased estimation of the drift of Brownian motion with linear stopping boundaries. Sequential Analysis 17: 91-107
  12. Liu A, Hall WJ. (1999). Unbiased estimation following a group sequential test. Biometrika 86: 71-78
  13. Gajjar A, Fouladi M, Walter A, Thompson S, Reardon D, Merchant T, Jenkins J, Liu A, Boyett J, Kun L, Heideman R. (1999). Comparison of lumbar and shunt cerebrospinal fluid specimens for cytologic detection of leptomeningeal disease in pediatric patients with brain tumors. Journal of Clinical Oncology 17: 1825-1828
  14. Fouladi M, Gajjar A, Boyett J, Walter W, Thompson S, Merchant T, Jenkins J, Langston J, Liu A, Kun L, Heideman R. (1999). Comparison of CSF cytology and spinal magnetic resonance imaging in the detection of leptomeningeal disease in pediatric medullblastoma or primitive neuroectodermal tumor.Journal of Clinical Oncology 17: 3234-3237
  15. Liu A, Boyett J, Xiong XP. (2000). Sample size calculation for planning group sequential longitudinal trials. Statistics in Medicine 19: 205-220
  16. Liu A, Tan M, Boyett J, Xiong XP. (2000). Testing secondary hypotheses following sequential clinical trials. Biometrics 56: 640-644
  17. Liu A. (2000). Maximum likelihood estimate following sequential probability ratio tests. Sequential Analysis 19: 63-75
  18. Smith K, Hale GM, Williams R, Ludwig M, Thompson A, Bowman L, Shochat S, Liu A, Barkley C. (2000). Comparison of two different low profile gastrostomy enteral feeding devices in pediatric oncology patients. Nutrition and Clinical Practice 15: 189-192
  19. Hayes AJ, Huang W, Yu J, Maisonpierre PC, Liu A, Kern FG, Lippman ME, McLeskey SW, Li L. (2000). Expression and function of angiopoietin-1 breast cancer. British Journal of Cancer 83: 1154-1160
  20. Pedrosa F, Bonilla M, Liu A, Smith K, Davis D, Ribeiro RC, Wilimas JA. (2000). Effect of malnutrition at the time of diagnosis on the survival of children treated forcancer in El Salvador and northernBrazil. Journal of Pediatric Hematology/Oncology 22: 502-505
  21. Liu A, Hall WJ. (2001). Unbiased estimation of secondary parameters following a sequential test. Biometrika 88: 895-900
  22. Liu A, Shih WJ, Gehan E. (2002). Sample size and power determination for clustered repeated measurements. Statistics in Medicine 21: 1787-1801
  23. Liu A. (2002). Efficient estimation of two seemingly unrelated regression equations. Journal of Multivariate Analysis 82: 445-456
  24. Liu A, Zhang Y, Gehan E, Clarke R. (2002). Block principal component analysis with application to gene microarray data classification. Statistics in Medicine 21: 3465-3474
  25. Hall WJ, Liu A. (2002). Sequential tests and estimates after overrunning based on maximum-likelihood ordering. Biometrika 89: 699-707
  26. Poola I, Abraham J, Liu A. (2002). Estrogen receptor beta splice variant mRNAs are differentially altered during breast carcinogenesis. Journal of Steroid Biochemistry and Molecular Biology 82: 169-179
  27. Lerman C, Roth D, Kaufmann V, Audrain J, Hawk L, Liu A, Niaura R, Epstein L. (2002). Mediating mechanisms for the impact of bupropion in smoking cessation treatment. Drug and Alcohol Dependence 67: 219-223
  28. Gu Z, Lee RY, Skaar TC, Bouker KB, Welch JN, Lu J, Liu A, Zhu Y, Davis N, Leonessa F, Brunner N, Wang Y, Clarke R. (2002). Association of interferon regulatory Factor-1, Nucleophosmin, nuclear Factor-kB, and cyclic AMP response element binding with acquired resistance to Faslodex (ICI 182,780). Cancer Research 62: 3428-3437
  29. Ellis M, Davis N, Coop A, Liu M, Schumaker L, Lee RY, Srikanchana R, Russell CG, Singh B, Miller WR, Stearns V, Pennanen M, Tsangaris T, Gallagher A, Liu A, Zwart A, Hayes DF, Lippman ME, Wang Y, Clarke R. (2002). Development and validation of a method for using breast core needle biopsies for gene expression microarray analyses. Clinical Cancer Research 8: 1155-1166
  30. Wong LJ, Wong IH, Liu A. (2002). Intergenerational transmission of pathogenic heteroplasmic mitochondrial DNA. Genetics in Medicine 4: 78-83
  31. Liu A. (2003). A simple low-bias estimate following a sequential test with linear boundaries. In: Crossing Boundaries: Statistical Essays in Honor of Jack Hall, IMS Monograph Series, Kolassa J and Oakes D, Editors, p 47-58
  32. Mazumdar M, Liu A. (2003). Group sequential design for comparative diagnostic accuracy studies. Statistics in Medicine 22: 727-739
  33. Liu A, Schisterman EF. (2003). Comparison of diagnostic accuracy of biomarkers with pooled assessments. Biometrical Journal 45: 631-644
  34. Liu A, Troendle JF, Yu KF, Yuan V. (2004). Conditional maximum likelihood estimation following a group sequential test. Biometrical Journal 46: 760-768
  35. Liu A, Schisterman EF, Teoh E. (2004). Sample size and power calculation in comparing diagnostic accuracy of biomarkers with pooled assessments. Journal of Applied Statistics 31: 49-59
  36. Blancato J, Singh B, Liu A, Liao DJ, Dickson RB. (2004). Correlation of amplification and over-expression of the c-myc oncogene in high-grade breast cancer: FISH, in situ hybridisation, and immunohistochemical analyses. British Journal of Cancer 90:1612-1619
  37. Dimitrakakis C, Jones RA, Liu A, Bondy CA. (2004). Breast cancer incidence in menopausal women using testosterone in addition to usual hormone therapy. Menopause 11:531-535
  38. Liu A, Schisterman EF, Zhu Y. (2005). On linear combinations of biomarkers to improve diagnostic accuracy. Statistics in Medicine 24: 37-47
  39. Liu A, Wu CQ, Yu KF, Gehan E. (2005). Supplementary analysis of probabilities at the termination of a group sequential phase II trial. Statistics in Medicine 24: 1009-1027
  40. Troendle, JF, Liu A, Wu CQ, Yu KF. (2005). Sequential testing for efficiency in clinical trials with non-transient effects. Statistics in Medicine 24: 3239-3250
  41. Liu A, Schisterman EF, Mazumdar M, Hu J. (2005). Power and sample size calculation of comparative diagnostic accuracy studies with multiple correlated test results. Biometrical Journal 47: 140-150
  42. Liu A, Schisterman EF, Wu CQ. (2005). Nonparametric estimation and hypothesis testing on the partial area under receiver operating characteristic curves. Communications in Statistics---Theory and Methods 34: 2077-2088
  43. Guo H, Liu A. (2005). A simple and efficient bias-reduced estimator of response probability following a group sequential phase II trial. Journal of Biopharmaceutical Statistics 15: 773–781
  44. Schisterman EF, Perkins N, Liu A, Bondell H. (2005). Optimal cut-point and its corresponding Youden index to discriminate individuals using pooled blood samples. Epidemiology 16: 73-81
  45. Wu CQ, Liu A, Yu KF. (2005). Estimation of secondary parameters after a multivariate group sequential test. In Contemporary Multivariate Analysis and Experimental Designs-In Celebration of Professor Kai-Tai Fang's 65th Birthday, 337-350. Fan J, Li G, Editors. The World Scientific Publisher
  46. Poola I, Fuqua SAW, DeWitty RL, Abraham J, Marshallack JJ, Liu A. (2005). ERα- negative breast cancer tissues express significant level of ERβ1 and ERβ5: potential molecular targets(s) for chemo-prevention. Clinical Cancer Research 11, 7579-7585
  47. Zhu Y, Singh B, Hewitt S, Liu A, Gomez B, Wang A, Clarker R. (2006). Expression patterns among interferon regulatory factor-1, human X-box binding protein-1, nuclear factor kappa B, nucleophosmin, estrogen receptor-alpha and progesterone receptor proteins in breast cancer tissue microarrays. International Journal of Oncology 28: 67-76
  48. Liu A, Hall WJ, Yu KF, Wu CQ. (2006). Estimation following a group sequential test for distributions in the one-parameter exponential family. Statistica Sinica 16: 165-181
  49. Liu A, Schisterman EF, Wu CQ. (2006). Multistage evaluation of measurement error in a reliability study. Biometrics 62:1190–1196
  50. Schisterman EF, Vexler A, Whitcomb BW, Liu A. (2006). The limitations due to exposure detection limits for regression models. American Journal of Epidemiology 163: 374-383
  51. Vexler A, Liu A, Schisterman EF, Wu CQ. (2006). Note on distribution-free estimation of maximum linear separation of two multivariate distributions. Journal of Nonparametric Statistics 18: 145-158
  52. Mumford SL, Schisterman EF, Vexler A, Liu A. (2006). Pooling biospecimens and limits of detection: Effects on ROC curve analysis. Biostatistics 7: 585-598
  53. Vexler A, Liu A, Schisterman EF. (2006). Efficient design and analysis of biospecimens with measurements subject to detection limit. Biometrical Journal 7: 780-791
  54. Liu A, Wu CQ, Yu KF, Yuan, V. (2007). Estimation following a multivariate group sequential test. Journal of Multivariate Analysis 98: 505-516
  55. Wu CQ, Liu A. (2007). An adaptive approach for bivariate phase II clinical trial designs. Contemporary Clinical Trials 28: 482-486
  56. Ferrari RM, Cooney MA, Vexler A, Liu A, Buck Louis GM. (2007). Time-to-pregnancy multiple births. Human Reproduction 22: 407-413
  57. Bondell HD, Liu A, Schisterman EF. (2007). Statistical inference based on pooled data: A moment-based estimating equation approach. Journal of Applied Statistics 34: 129-140
  58. Bai RK, Leal SM, Covarrubias D, Liu A, Wong LJ. (2007). Mitochondrial genetic background modifies breast cancer risk. Cancer Research 67: 4687-4694
  59. Liu A, Wu CQ, Yu KF. (2007). Incorporating overrunning data into the analysis of both primary and secondary endpoints in a sequential trial. In Random Walk, Sequential Analysis and Related Topics-A Festschrift in Honor of Yuan-Shih Chow. Ying ZL, Zhang CH Editors. The World Scientific Publisher: New Jersey, pp. 56-68
  60. Bloom MS, Buck Louis GM, Schisterman EF, Liu A, Kostyniak PK. (2007). Maternal serum polychlorinated biphenyl concentrations across critical windows of human development. Environmental Health Perspectives 115: 1320-1324
  61. Shu Y, Liu A, Li ZH. (2007).Sequential evaluation of a medical diagnostic test with binary outcomes. Statistics in Medicine 26: 4416-4427
  62. Vexler A, Schisterman EF, Liu A. (2008). Estimation of ROC based on stably distributed biomarkers subject to measurement error and pooling mixtures. Statistics in Medicine 27:280–296
  63. Wu CQ, Liu A, Yu KF. (2008). An adaptive approach to designing comparative diagnostic accuracy studies. Journal of Biopharmaceutical Statistics 18: 116-125
  64. Browne RW, Bloom MS, Schisterman EF, Hovey K, Trevisan M, Wu CQ, Liu A, Wactawski-Wende J. (2008). Analytical and biological variation of biomarkers of oxidative stress during the menstrual cycle. Biomarkers 13:160-183
  65. Liu A, Wu CQ, Yu KF. (2008). Point and interval estimation of primary and secondary parameters in a two-stage adaptive clinical trial. Journal of Biopharmaceutical Statistics 18:211-226
  66. Liu A, Wu CQ, Schisterman EF. (2008). Nonparametric sequential evaluation of diagnostic biomarkers. Statistics in Medicine 27:1667-1678
  67. Liu A, Wu CQ, Yu KF. (2008). Two-stage procedures for selecting the best diagnostic biomarkers. Philosophical Transaction of the Royal Society A 366: 2293-2299
  68. Shu Y, Liu A, Li ZH. (2008). Point and interval estimates of accuracies of a binary medical diagnostic test in group sequential designs. Philosophical Transaction of the Royal Society A 366:2335-2345
  69. VexlerA, Liu A, Eliseeva E, Schisterman EF. (2008). Maximum likelihood ratio tests for comparing the discriminatory ability of biomarkers subject to limit of detection. Biometrics 64: 895-903
  70. Zhang J, Masciocchi M, Lewis D, Sun W, Liu A, Wang Y. (2008). Placental anti-oxidant gene polymorphisms, enzyme activity, and oxidative stress in preeclampsia. Placenta 29: 439-443
  71. Poola I, Abraham J, Liu A, Marshalleck J, DeWitty R. (2008). The cell surface estrogen receptor, G protein-coupled receptor 30 (GPR30), is markedly down-regulated During Breast Tumorigenesis. Breast Cancer: Basic and Clinical Research 1: 65-78
  72. Wactawski-Wende J, Schisterman EF, Hovey KM, Howards P, Browne RW, Hediger M, Liu A, Trevisan M ; BioCycle Stusy Group. (2009). BioCycle Study: Design of the longitudinal study of the oxidative stress and hormone variation during the menstrual cycle. Paediatric and Perinatal Epidemiology 23: 171-184
  73. Wu MX, Yu KF, Liu A. (2009). Exact inference on contrasts in means of intraclass correlation models with missing responses. Journal of Multivariate Analysis 100: 301-308
  74. Li, QZ, Liu A, Yu K, Yu, KF. (2009). A weighted rank-sum procedure for comparing samples with multiple endpoints. Statistics and Its Interface 2: 197-201
  75. Wu MX, Yu KF, Liu A. (2009). Estimation of variance components in the mixed-effects models: A comparison between analysis of variance and spectral decomposition. Journal of Statistical Planning and Inference 139: 3962-3973
  76. Yang S, Liu A, Weidenhammer A, Cooksey RC, McClain D, Kim MK, Aguilera G, Abel ED, Chung JH. (2009). The role of mPer2 clock gene in glucocorticoid and feeding rhythms. Endocrinology 150: 2153-2160
  77. Vexler A, Wu CQ, Liu A, Whitcomb BW, Schisterman EF. (2009). An extension of a change point problem. Statistics 3: 213-225
  78. Tang L, Liu A. (2010). Sample size recalculation in sequential diagnostic trials. Biostatistics 11: 151-163
  79. Li QZ, Zheng G, Liu A, Xiong SF, Li ZH, Yu K. (2010). The limiting bound of Efron’s W-formula for hypothesis testing when a nuisance parameter is present only under the alternative. Journal of Statistical Planning and Inference 140: 1610–1617
  80. Liu A, Li QZ, Liu CL, Yu K, Yu KF. (2010). A Rank-Based test for comparison of multidimensional outcomes. Journal of the American Statistical Association 105: 578-587
  81. Whitcomb BW, Bodach SD, Mumford SL, Perkins NJ, Trevisan M, Wactawski-Wende J, Liu A, Schisterman EF. (2010). Ovarian function and cigarette smoking. Paediatric and Perinatal Epidemiology 25: 433-440
  82. Vexler A, Liu A, Schisterman EF. (2010). Nonparametric deconvolution of density estimation based on observed sums. Journal of Nonparametric Statistics 22: 23-29
  83. Liu A, Liu CL, Li, QZ, Yu KF, Yuan V. (2010). A threshold sample-enrichment approach in a clinical trial with heterogeneous populations. Clinical Trials 7:537-545
  84. Li QZ, Zheng G, Liu A, Li ZH, Yu K. (2010). Approximating probabilities of correlated events with applications to multiple testing. Science in China A 53:2937-2948
  85. Liu CL, Liu A, Halabi S. (2011). Min-max combination of biomarkers to improve diagnostic accuracy. Statistics in Medicine 30: 2005–2014
  86. Pan D, Li, QZ, Jiang N, Liu A, Yu K. (2011). Robust joint analysis allowing for model uncertainty in two-stage genetic association studies. BMC Bioinformatics 12(1):9
  87. Yan LK, Liu A, Li ZH, Zheng G. (2011). Optimal two-stage sequential design for case-control genetic association studies. Statistics and Its Interface 4:431–441
  88. Liu A, Liu CL, Zhang Z, Albert PF. (2012). Optimality of group testing in the presence of misclassification. Biometrika 99:245–251
  89. Mills JL, Carter TC, Kay DM, Browne ML, Brody LC, Liu A, Romitti PA, Caggana M, Druschel CM. (2012). Folate and vitamin B12 related genes and risk for omphalocele. Human Genetics 131:739–746.
  90. Nansel TR, Iannotti RJ, Liu A. (2012). Clinic-integrated behavioral intervention for families of youth with type 1 diabetes: A Randomized Clinical Trial. Pediatrics 129: 866-873.
  91. Wu MX, Yu KF, Liu A, Ma TF. (2012). Simultaneous optimal estimation in linear mixed effects models. Metrika 75:471–489.
  92. Browne ML, Caner TC, Kay DM, Kuehn D, Brody LC, Romitti PA, Liu A, Caggana M, Druschel CM, Mills JM. (2012). Evaluation of genes involved in limb development, angiogenesis, and coagulation as risk factors for congenital limb deficiencies. American Journal of Medical Genetics A 158A: 2643-2472.
  93. Fan R, Zhang Y, Albert PS, Liu A, Wang Y, Xiong M. (2012). Longitudinal association analysis of quantitative traits. Genetic Epidemiology 36:856–869.
  94. Zhang Z, Liu A, Lyles RH, Mukherjee B. (2012). Logistic regression analysis of biomarker data subject to pooling and dichotomization. Statistics in Medicine 31:2473-2484.
  95. Song Y, Yeung E, Liu A, VanderWeele TJ, Chen L, Lu C, Liu C, Schisterman EF, Ning Yi, Zhang C. (2012). Pancreatic beta-cell function and type 2 diabetes risk: quantify the causal effect using a Mendelian randomization approach based on meta-analyses. Human Molecular Genetics 21(22):5010-5018.
  96. Carter TC, Kay DM Brownw ML, Liu A, Romitti PA, Kuehn D, Conley MR, Caggana M, Druschel CM, Brody LC, Mills JL. (2012). Hirschsprung’s disease and variants in genes that regulate enteric neural crest cell proliferation, migration, and differentiation. Journal of Human Genetics 57:485-493.
  97. Tang L, Liu A, Schisterman EF, Zhou X, Liu C. (2012). Homogeneity tests of clustered diagnostic markers with applications to the BioCycle Study. Statistics in Medicine 31:3638-3648.
  98. Carter TC, Kay DM, Browne ML, Liu A, Romitti PA, Kuehn D, Conley MR, Caggana M, Druschel CM, Brody LC, Mills JL. (2013). Anorectal atresia and variants at predicted regulatory sites in candidate genes. Annals of Human Genetics 77:31-46.
  99. Tang L, Kang L, Liu C, Schisterman EF, Liu A. (2013). An additive selection of markers to improve diagnostic accuracy based on a discriminatory measure. Academic Radiology 20:854–862
  100. Fan R, Lee A, Lu Z, Liu A, Troendle JF, Mills JL. (2013). Association analysis of complex disease using triads, parent-child dyads and singleton monads. BMC Genetics, 14:78.
  101. Tang L, Liu A, Chen Z, Schisterman EF, Zhang B, Miao Z. (2013). Nonparametric ROC summary statistics for clustered diagnostic marker data. Statistics in Medicine, 32: 2209-2220.
  102. Jin M, Liu A, Chen Z, Li ZH. (2013). Group sequential design in inter-rater reliability study. Statistica Sinica, 23:1743-1759.
  103. Sarkar C, Chandra G, Peng S, Zhang Z, Liu A, and Mukherjee A. (2013). A Thioesterase-mimetic arrests neuropathology and extends lifespan in a mouse model of a neurodegenerative lysosomal storage disease. Nature Neuroscience,16:1608-1617
  104. Li QZ, Li ZB, Liu A, Li ZH. Rank-based tests for comparison of multiple endpoints among several populations. Statistics and Its Interface. (In press)
  105. Kang L, Liu A, Tian L. Linear combination methods to improve diagnostic/prognostic accuracy on future observations. Statistical Methods in Medical Research. (In press)
  106. Li QZ, Xiong WJ, Chen J, Zheng G, Li ZH, Mills JM, Liu A. A robust test for quantitative trait in genetic association studies. Statistics and Its Interface. (In press)
  107. Albert PS, Liu A, Nansel T. Estimation and design for logistic regression under an imperfect population identifier. Biometrics. (In press)
  108. Liu C, Liu A, Zhang B, Zhang Z. Improved confidence intervals of a small probability from pooled testing with misclassification. Frontiers in Epidemiology. (In press).
  109. Nansel T, Lipsky LM, Liu A, Laffel L, Mehta S. Contextual factors are associated with diet quality in youth with type 1 diabetes. Journal of the Academy of Nutrition and Dietetics. (In press)
  110. Zhang Z, Nie L, Soon G and Liu A. The use of covariates and random effects in evaluating predictive biomarkers under a potential outcome framework. Annual of Applied Statistics. (Revision invited)
  111. Liu CL, Liu A, Hu J, Yuan V, Halabi S. Adjusting for misclassification in stratified biomarker clinical trials. Statistics in Medicine. (Revision invited)
  112. Zhang Z, Liu C, Kim S, Liu A. Prevalence Estimation Subject to Misclassification: the Misspecification Bias and Some Remedies. Statistics in Medicine. (Revision invited)
  113. Liu CL, Liu A, Wu MX, Schisterman EF. Interval estimation and hypothesis testing in disease-association studies with data subject to limits of detection. Statistics and Its Interface. (Revision invited)

BOOKS AND BOOK CHAPTERS

  1. Liu A, Schisterman EF. Principal component analysis. In Encyclopedia of Biopharmaceutical Statistics,2nd ed. 2004
  2. Liu A, Yu KF. Inference following a sequential clinical trial. In Clinical Trials Handbook, Wiley, 2009
  3. Liu A, Liu CL, Yu KF. Group-Sequential methods in biomedical research. In Methods and Applications of Statistics in the Life and Health Sciences. Wiley, 2009
  4. Liu A, Liu CL, Yu KF. Group-Sequential methods in biomedical research. In Encyclopedia of Statistical Sciences. Wiley, 2010
  5. Zou KH, Liu A, Bandos A, Ohno-Machado L, Rockette H. Statistical Evaluation of Diagnostic Performance: Topics in ROC Analysis. Chapman & Hall/CRC, New York, 2011

MANUSCRIPTS SUBMITTED