Background: Random Forests is a popular classification and regression method that has proven powerful for various prediction problems in biological studies. However, its performance often deteriorates when the number...
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Background: Random Forests is a popular classification and regression method that has proven powerful for various prediction problems in biological studies. However, its performance often deteriorates when the number of features increases. To address this limitation, feature elimination Random Forests was proposed that only uses features with the largest variable importance scores. Yet the performance of this method is not satisfying, possibly due to its rigid feature selection, and increased correlations between trees of forest. Methods: We propose variable importance-weighted Random Forests, which instead of sampling features with equal probability at each node to build up trees, samples features according to their variable importance scores, and then select the best split from the randomly selected features. Results: We evaluate the performance of our method through comprehensive simulation and real data analyses, for both regression and classification. Compared to the standard Random Forests and the feature elimination Random Forests methods, our proposed method has improved performance in most cases. Conclusions: By incorporating the variable importance scores into the random feature selection step, our method can better utilize more informative features without completely ignoring less informative ones, hence has improved prediction accuracy in the presence of weak signals and large noises. We have implemented an R package "viRandomForests" based on the original R package "randomForest" and it can be freely downloaded from http:// ***/software.
The analysis of cancer genomic data has long suffered "the curse of dimensionality". Sample sizes for most cancer genomic studies are a few hundreds at most while there are tens of thousands of genomic featu...
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In this review, we describe the relationship between systems biology and text mining. On the one hand, text mining functions as a practical tool for systems biology research, which integrates diverse sub-fields and ta...
Chemical genomics has been applied extensively to evaluate small molecules that modulate biological processes in Saccharomyces ***,we use yeast as a surrogate system for studying compounds that are active against meta...
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Chemical genomics has been applied extensively to evaluate small molecules that modulate biological processes in Saccharomyces ***,we use yeast as a surrogate system for studying compounds that are active against metazoan ***-scale chemical-genetic profiling of thousands of synthetic and natural compounds from the Chinese National Compound Library identified those with high-confidence bioprocess target *** discover compounds that have the potential to function like therapeutic agents with known targets,we also analyzed a reference library of approved *** uncharacterized compounds with chemical-genetic profiles resembling existing drugs that modulate autophagy and Wnt/β-catenin signal transduction were further examined in mammalian cells,and new modulators with specific modes of action were *** analysis exploits yeast as a general platform for predicting compound bioactivity in mammalian cells.
The Warburg effect,characterized by increased glucose uptake and lactate production,is a well-known universal across cancer-and other ***2,a splice isoform of the pyruvate kinase(PK) specifically expressed in these ...
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The Warburg effect,characterized by increased glucose uptake and lactate production,is a well-known universal across cancer-and other ***2,a splice isoform of the pyruvate kinase(PK) specifically expressed in these cells,serves as a major regulator of this metabolic reprogramming with an adjustable activity subjected to numerous allosteric effectors and posttranslational *** we have identified a novel posttranslational modification on PKM2,O-GlcNAcylation,which specifically targets Thr and Ser,residues of the region encoded by the alternatively spliced exon 10 in cancer *** show that PKM2 O-GlcNAcylation is upregulated in various types of human tumor cells and patient tumor *** modification destabilized the active tetrameric PKM2,reduced PK activity and led to nuclear translocation of *** also observed that the modification is associated with an increased glucose consumption and lactate production,and enhanced level of lipid and DNA synthesis,indicating that O-GlcNAcylation promotes the Warburg *** vivo experiments showed that blocking PKM2 O-GlcNAcylation attenuated tumor ***,we demonstrate that O-GlcNAcylation is a new regulatory mechanism for PKM2 in cancer cells and serves as a bridge between PKM2 and metabolic reprogramming typical of the Warburg effect.
Human immunology studies typically examine how immune exposures associated with vaccinations, infectious, allergic or autoimmune diseases, or transplantations perturb the immune system with the goal to develop diagnos...
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