Department of
Epidemiology &
Biostatistics

Genetic Epidemiology

Global Health

Behavior and Prevention

Health Care

Modern Biostatistics

Nathan Morris, Ph.D.
Sr. Instructor

 


Office: Wolstein Research Bldg. 1303
Phone: (216) 368-5634
E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

nophoto
Education
Ph.D. 2009, Genetic Epidemiology, Case Western Reserve University
M.S. 2004, Statistics, University of Akron
B.S. 2001, Mathematics, Cleveland State University
B.A. 2001, Physics, Cleveland State University
Research Interests
Statistical Genetics; Structural Equation Models; Genetic Linkage Analysis; Multivariate Analysis.

Courses Taught
EPBI 437 - Essence of Classical Multivariate Analysis - 1 credit hr mini course
EPBI 438 - Essence of Structural Equation Modeling - 1 credit hr mini course
Professional Memberships
American Society of Human Genetics
International Genetic Epidemiology Society
Recent Publications

Larkin E, Morris N, Li Y, Nock N, Stein C (2007) Comparison of affected sibling-pair linkage methods to identify gene x gene interaction in GAW15 simulated data. BMC Proceedings. 1(Suppl 1): S66.

Won S, Morris N, Lu Q, Elston R (2009) Choosing an optimal method to combine p-values. Stat in Med. 28(11):1537-53.

Morris N, Gray-McGuire C, Stein C (2009) Mendelian randomization in family data. BMC Proceedings. 3(Suppl 7): S45.

Gray-McGuire C, Song Y, Morris N, Stein C (2009) Comparison of univariate and multivariate linkage analysis of traits related to hypertension. BMC Proceedings. 3(Suppl 7): S99. 

Morris N, Stein C and Elston R (2009) Calculating asymptotic significance levels of the constrained likelihood ratio test with application to multivariate genetic linkage analysis. Stat Apl Gen Mol Bio. 8(1): Article 39.

Kim S, Morris N, Won S, Elston R (2010) Single- and Two-marker Association tests for unphased case-control genotype data and a power comparison. Genet. Epi. 34(1):67-77.

Xing C, Morris N, Xing G (2010) Distribution of Model-based Multipoint Heterogeneity Lod Scores. Genet. Epi.

Qin H, Morris N, Kang SJ, Li M, Tayo B, Lyon H, Hirschhorn J, Cooper RS, Zhu X. (2010) Interrogating local population structure for fine mapping in genome-wide association studies. Bioinformatics. 26(23):2961-2968

Morris N, Elston R and Stein C (2010) A general structural equation modeling framework for family data. Human Hered. 70(4): 278-286.

Morris N, Elston R (2011) A Note on Comparing the Power of Test Statistics at Low Significance Levels. The American Stat.65(3): 164-166.

Morris N, Stein C (2011) Model-Free Linkage Analysis of a Quantitative Trait. In Elston R, Satagapan J, Sun S (Eds.) Statistical Human Genetics (p 495-512). New York: Springer (Humana Press). 

Stein C, Morris N,  Nock N (2011) Structural Equation Modeling. In Elston R, Satagapan J, Sun S (Eds.) Statistical Human Genetic.(p 301-316). New York: Springer (Humana Press).

Wang X, Qin H, Morris N, Zhu X, Elston R. (2011) Testing gene-environment interactions in gene-based association studies. BMC Proce edings. 5(Suppl 9):S26.

Wang X, Morris N, Schaid D and Elston R (2012) Power of Single- vs. Multi-Marker Tests of Association. Genetic. Epi. 36(5):480-7.

Sattar A, Sinha S, Morris N. (2012) A parametric survival Model when a covariate is subject to left censoring. J of Biomet & Biostat. , S3:002. doi:10.4172/2155-6180.S3-002.

Wang X, Morris N, Zhu X, Elston R (2013) A variance component based multi-marker association test using family and unrelated data. BMC Genetic. doi:10.1186/1471-2156-14-17.

Bencheck P, Morris N (2013) How meaningful are heritability estimates of liability? Hum Genetic. doi:10.1007/s00439-013-1334-z.

Xiangqing A, Elston R, Morris N, Zhu X (2013) What Is the Significance of Difference in Phenotypic Variability across SNP Genotypes? The American Journal of Human Genetics. 93(2) pp. 390–397.

Liu Y, Qin X, Wang D, Guo Y, Gill H, Morris N, Parker M, Chen L, and Boron W (2013) Effects of optional structural elements, including two alternative amino termini and a new splicing cassette IV, on the function of NBCn1 (SLC4A7). Journal of Physiology. 591(Pt 20):4983-5004.

Frazier TW,  Thompson L. Youngstrom E, Law P, Hardan A, Eng C and Morris N (2014). A Twin Study of Heritable and Shared Environmental Contributions to Autism. J Autism Dev Disord. [In Press]

 

Software
gmatrix: An R Package for Harnessing GPU Power
This package implements a general framework for utilizing R to harness the power of NVIDIA GPU's. The "gmatrix" and "gvector" classes allow for easy management of the separate device and host memory spaces. Numerous numerical operations are implemented for these objects on the GPU. These operations include matrix multiplication, addition, subtraction, the kronecker product, the outer product, comparison operators, logical operators, trigonometric functions, indexing, sorting, random number generation and many more.
The gitub page with installation instructions is: https://github.com/njm18/gmatrix/
The package may also be downloaded here: http://solomon.case.edu/gmatrix/

strum: STRUctural Modeling of Latent Variables for General Pedigree
This package implements a broad class of latent variable and structural equation models for general pedigree data. This includes a framework for simulating multivariate pedigree data with realistic linkage disequilibrium, accounting for asscertainment biases, linkage anylsis, polygenic models and plotting graphs of the model.
The package and several vignettes are available on CRAN:  http://cran.r-project.org/web/packages/strum/index.html

fassoc: An R Package which Performs Variance Components Based Multi-Marker Association Tests in Families.
The package may also be downloaded here: https://r-forge.r-project.org/R/?group_id=1379

Last Updated (Tuesday, 01 April 2014 16:39)

 
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