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Articles 1 - 12 of 12
Full-Text Articles in Genetics and Genomics
Bayesian Analysis Of Cell-Cycle Gene Expression Data, Chuan Zhou, Jon Wakefield, Linda Breeden
Bayesian Analysis Of Cell-Cycle Gene Expression Data, Chuan Zhou, Jon Wakefield, Linda Breeden
UW Biostatistics Working Paper Series
The study of the cell-cycle is important in order to aid in our understanding of the basic mechanisms of life, yet progress has been slow due to the complexity of the process and our lack of ability to study it at high resolution. Recent advances in microarray technology have enabled scientists to study the gene expression at the genome-scale with a manageable cost, and there has been an increasing effort to identify cell-cycle regulated genes. In this chapter, we discuss the analysis of cell-cycle gene expression data, focusing on a model-based Bayesian approaches. The majority of the models we describe …
Optimal Feature Selection For Nearest Centroid Classifiers, With Applications To Gene Expression Microarrays, Alan R. Dabney, John D. Storey
Optimal Feature Selection For Nearest Centroid Classifiers, With Applications To Gene Expression Microarrays, Alan R. Dabney, John D. Storey
UW Biostatistics Working Paper Series
Nearest centroid classifiers have recently been successfully employed in high-dimensional applications. A necessary step when building a classifier for high-dimensional data is feature selection. Feature selection is typically carried out by computing univariate statistics for each feature individually, without consideration for how a subset of features performs as a whole. For subsets of a given size, we characterize the optimal choice of features, corresponding to those yielding the smallest misclassification rate. Furthermore, we propose an algorithm for estimating this optimal subset in practice. Finally, we investigate the applicability of shrinkage ideas to nearest centroid classifiers. We use gene-expression microarrays for …
A New Approach To Intensity-Dependent Normalization Of Two-Channel Microarrays, Alan R. Dabney, John D. Storey
A New Approach To Intensity-Dependent Normalization Of Two-Channel Microarrays, Alan R. Dabney, John D. Storey
UW Biostatistics Working Paper Series
A two-channel microarray measures the relative expression levels of thousands of genes from a pair of biological samples. In order to reliably compare gene expression levels between and within arrays, it is necessary to remove systematic errors that distort the biological signal of interest. The standard for accomplishing this is smoothing "MA-plots" to remove intensity-dependent dye bias and array-specific effects. However, MA methods require strong assumptions. We review these assumptions and derive several practical scenarios in which they fail. The "dye-swap" normalization method has been much less frequently used because it requires two arrays per pair of samples. We show …
An Introduction To Low-Level Analysis Methods Of Dna Microarray Data, Wolfgang Huber, Anja Von Heydebreck, Martin Vingron
An Introduction To Low-Level Analysis Methods Of Dna Microarray Data, Wolfgang Huber, Anja Von Heydebreck, Martin Vingron
Bioconductor Project Working Papers
This article gives an overview over the methods used in the low--level analysis of gene expression data generated using DNA microarrays. This type of experiment allows to determine relative levels of nucleic acid abundance in a set of tissues or cell populations for thousands of transcripts or loci simultaneously. Careful statistical design and analysis are essential to improve the efficiency and reliability of microarray experiments throughout the data acquisition and analysis process. This includes the design of probes, the experimental design, the image analysis of microarray scanned images, the normalization of fluorescence intensities, the assessment of the quality of microarray …
Simultaneous And Exact Interval Estimates For The Contrast Of Two Groups Based On An Extremely High Dimensional Response Variable: Application To Mass Spec Data Analysis, Yuhyun Park, Sean R. Downing, Cheng Li Dr., William C. Hahn, Philip W. Kantoff, L. J. Wei
Simultaneous And Exact Interval Estimates For The Contrast Of Two Groups Based On An Extremely High Dimensional Response Variable: Application To Mass Spec Data Analysis, Yuhyun Park, Sean R. Downing, Cheng Li Dr., William C. Hahn, Philip W. Kantoff, L. J. Wei
Harvard University Biostatistics Working Paper Series
No abstract provided.
The Optimal Discovery Procedure: A New Approach To Simultaneous Significance Testing, John D. Storey
The Optimal Discovery Procedure: A New Approach To Simultaneous Significance Testing, John D. Storey
UW Biostatistics Working Paper Series
Significance testing is one of the main objectives of statistics. The Neyman-Pearson lemma provides a simple rule for optimally testing a single hypothesis when the null and alternative distributions are known. This result has played a major role in the development of significance testing strategies that are used in practice. Most of the work extending single testing strategies to multiple tests has focused on formulating and estimating new types of significance measures, such as the false discovery rate. These methods tend to be based on p-values that are calculated from each test individually, ignoring information from the other tests. As …
The Optimal Discovery Procedure For Large-Scale Significance Testing, With Applications To Comparative Microarray Experiments, John D. Storey, James Y. Dai, Jeffrey T. Leek
The Optimal Discovery Procedure For Large-Scale Significance Testing, With Applications To Comparative Microarray Experiments, John D. Storey, James Y. Dai, Jeffrey T. Leek
UW Biostatistics Working Paper Series
As much of the focus of genetics and molecular biology has shifted toward the systems level, it has become increasingly important to accurately extract biologically relevant signal from thousands of related measurements. The common property among these high-dimensional biological studies is that the measured features have a rich and largely unknown underlying structure. One example of much recent interest is identifying differentially expressed genes in comparative microarray experiments. We propose a new approach aimed at optimally performing many hypothesis tests in a high-dimensional study. This approach estimates the Optimal Discovery Procedure (ODP), which has recently been introduced and theoretically shown …
Analysis Of Affymetrix Genechip Data Using Amplified Rna, Leslie Cope, Scott M. Hartman, Hinrich W.H. Gohlmann, Jay P. Tiesman, Rafael A. Irizarry
Analysis Of Affymetrix Genechip Data Using Amplified Rna, Leslie Cope, Scott M. Hartman, Hinrich W.H. Gohlmann, Jay P. Tiesman, Rafael A. Irizarry
Johns Hopkins University, Dept. of Biostatistics Working Papers
The standard method of target synthesis for hybridization to Affymetrix GeneChip® expression microarrays requires a relatively large amount of input total RNA (1-15 micrograms). When small biological samples are collected by microdissection or other methods, amplification techniques are required to provide sufficient target for hybridization to expression arrays. One amplification technique used is to perform two successive rounds of T7-based in vitro transcription. However, the use of random primers required to re-generate cDNA from the first round transcription reaction results in shortened copies of the cDNA, and ultimately the cRNA, transcripts from which the 5' end is missing. In this …
New Statistical Paradigms Leading To Web-Based Tools For Clinical/Translational Science, Knut M. Wittkowski
New Statistical Paradigms Leading To Web-Based Tools For Clinical/Translational Science, Knut M. Wittkowski
COBRA Preprint Series
As the field of functional genetics and genomics is beginning to mature, we become confronted with new challenges. The constant drop in price for sequencing and gene expression profiling as well as the increasing number of genetic and genomic variables that can be measured makes it feasible to address more complex questions. The success with rare diseases caused by single loci or genes has provided us with a proof-of-concept that new therapies can be developed based on functional genomics and genetics.
Common diseases, however, typically involve genetic epistasis, genomic pathways, and proteomic pattern. Moreover, to better understand the underlying biologi-cal …
Cluster Analysis Of Genomic Data With Applications In R, Katherine S. Pollard, Mark J. Van Der Laan
Cluster Analysis Of Genomic Data With Applications In R, Katherine S. Pollard, Mark J. Van Der Laan
U.C. Berkeley Division of Biostatistics Working Paper Series
In this paper, we provide an overview of existing partitioning and hierarchical clustering algorithms in R. We discuss statistical issues and methods in choosing the number of clusters, the choice of clustering algorithm, and the choice of dissimilarity matrix. In particular, we illustrate how the bootstrap can be employed as a statistical method in cluster analysis to establish the reproducibility of the clusters and the overall variability of the followed procedure. We also show how to visualize a clustering result by plotting ordered dissimilarity matrices in R. We present a new R package, hopach, which implements the hybrid clustering method, …
Real-Time Reverse Transcription Pcr For Detection And Quantitative Analysis Of Equine Influenza Virus., Michelle Quinlivan, Eugene Dempsey, Fergus Ryan, Sean Arkins, Ann Cullinnane
Real-Time Reverse Transcription Pcr For Detection And Quantitative Analysis Of Equine Influenza Virus., Michelle Quinlivan, Eugene Dempsey, Fergus Ryan, Sean Arkins, Ann Cullinnane
Articles
Equine influenza is a cause of epizootic respiratory disease of the equine. The detection of equine influenza virus using real-time Light Cycler reverse transcription (RT)-PCR technology was evaluated over two influenza seasons with the analysis of 171 samples submitted for viral respiratory disease. Increased sensitivity was found in overall viral detection with this system compared to Directigen Flu A and virus isolation, which were 40% and 23%, respectively, that of the RT-PCR. The assay was also evaluated as a viable replacement for the more traditional methods of quantifying equine influenza virus, 50% egg infectious dose and 50% tissue culture infectious …
Validation Of A Multiplex Pcr Assay For The Simultaneous Detection Of Human Papillomavirus And Chlamydia Trachomatis In Cervical Preservcyt Samples., Helen Keegan, Alison Malkin, Mairead Griffin, Fergus Ryan, Helen Lambkin
Validation Of A Multiplex Pcr Assay For The Simultaneous Detection Of Human Papillomavirus And Chlamydia Trachomatis In Cervical Preservcyt Samples., Helen Keegan, Alison Malkin, Mairead Griffin, Fergus Ryan, Helen Lambkin
Articles
No abstract provided.