We present a methodology to analyze zebrafish knock-out experiment replicated tune series microarray data. The knock-out experiment aimed to elucidate the transcriptomal regulators underlying the glycocalyx-regulation...
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ISBN:
(纸本)9783642025037
We present a methodology to analyze zebrafish knock-out experiment replicated tune series microarray data. The knock-out experiment aimed to elucidate the transcriptomal regulators underlying the glycocalyx-regulation of vasculogenesis by performing global gene expression analysis of NDST mutants and wild-type siblings at three distinct tune points during development. Cluster analysis and the construction of a genetic interaction network allows to identify groups of genes acting ill the process of early stage vasculogenesis. We report;the following findings: we found a large number of gene clusters, particularly glycans, during the three developmental steps of the zebrafish organism. In each step;genes connectivity changes according to two different powerlaws. The clusters are highlighted ill such a way;that it is possible to see the dynamics of the interactions through the time points recorded ill tire microarray experiment. Vegf-related genes seem riot to be involved at transcriptomics level, suggesting alternative regulative pathways do exist, to modulate transcriptomal signatures ill developing zebrafish. Our results show that, there are several glycan-related genies which may be involved in early processes such as vasculogenesis.
Motivation: Many applications of microarray technology in clinical cancer studies aim at detecting molecular features for refined diagnosis. In this paper, we follow an opposite rationale: we try to identify common mo...
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Objectives: Classification of breast cancer patients into different risk classes is very important in clinical applications. It is estimated that the advent of high-dimensional gene expression data could improve patie...
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Many studies have used microarray technology to identify the molecular signatures of human cancer, yet the critical features of these often unmanageably large set of signatures remain elusive. We have investigated co-...
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Missing values of microarray dataset are imputed with the help of gene expression sample values. The process by which missing values are calculated is the mean of gene expression sample values and then discretized the...
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ISBN:
(纸本)9789811524493;9789811524486
Missing values of microarray dataset are imputed with the help of gene expression sample values. The process by which missing values are calculated is the mean of gene expression sample values and then discretized the sample values. Those discretized values are used to find the similarities between gene expressions with missing value-related genes and genes with no missing values. The gene from without missing values which is most similar of each missing value-related gene is selected, and Pearson's correlation coefficient of the identified gene with all no missing valuerelated genes is calculated. Now, the genes which have higher correlation coefficient with respect to a threshold value are identified. At last, the missing position of the gene is imputed with the mean expression values of the no missing value-related genes which are selected based on correlation coefficient values.
Advances in the field of microarray technology have attracted a lot of attention in recent years. More and more biological experiments are conducted based on microarrays. The challenge researchers face today is to ana...
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ISBN:
(纸本)9780769532684
Advances in the field of microarray technology have attracted a lot of attention in recent years. More and more biological experiments are conducted based on microarrays. The challenge researchers face today is to analyze and understand the collected data. We present a visual approach to support understanding microarray data. In contrast to other visualization techniques, which represent expression of genes, we go one step further and make a switch to combinations of genes. Gene combinations bear more information, and hence, can lead to new hypotheses about the data. However the increased amount of information imposes several challenges to an interactive visualization approach. We propose analytical and visual methods to deal with these challenges.
The advent of DNA microarray technologies has revolutionized the experimental study of gene expression. Clustering is the most popular approach of analyzing gene expression data and has indeed proven to be successful ...
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ISBN:
(纸本)0769521940
The advent of DNA microarray technologies has revolutionized the experimental study of gene expression. Clustering is the most popular approach of analyzing gene expression data and has indeed proven to be successful in many applications. Our work focuses on discovering a subset of genes which exhibit similar expression patterns along a subset of conditions in the gene expression matrix. Specifically, we are looking for the Order Preserving clusters (OP-Cluster), in each of which a subset of genes induce a similar linear ordering along a subset of conditions. The pioneering work of the OPSM model[3], which enforces the strict order shared by the genes in a cluster, is included in our model as a special case. Our model is more robust than OPSM because similarly expressed conditions are allowed to form order equivalent groups and no restriction is placed on the order within a group. Guided by our model, we design and implement a deterministic algorithm, namely OPC-Tree, to discover OP-Clusters. Experimental study on two real datasets demonstrates the effectiveness of the algorithm in the application of tissue classification and cell cycle identification. In addition, a large percentage of OP-Clusters exhibit significant enrichment of one or more function categories, which implies that OP-Clusters indeed carry significant biological relevance.
Mining of gene expression data to identify genes associated with patient survival is an ongoing problem in cancer prognostic studies using microarrays in order to use such genes to achieve more accurate prognoses. The...
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Mining of gene expression data to identify genes associated with patient survival is an ongoing problem in cancer prognostic studies using microarrays in order to use such genes to achieve more accurate prognoses. The least absolute shrinkage and selection operator (lasso) is often used for gene selection and parameter estimation in high-dimensional microarray data. The lasso shrinks some of the coefficients to zero, and the amount of shrinkage is determined by the tuning parameter, often determined by cross validation. The model determined by this cross validation contains many false positives whose coefficients are actually zero. We propose a method for estimating the false positive rate (FPR) for lasso estimates in a high-dimensional Cox model. We performed a simulation study to examine the precision of the FPR estimate by the proposed method. We applied the proposed method to real data and illustrated the identification of false positive genes.
We propose a novel statistical method for estimating gene networks based on microarray gene expression data together with information from biological knowledge databases. Although a large amount of gene regulation inf...
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