GLORIA

GEOMAR Library Ocean Research Information Access

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Online-Ressource
    Online-Ressource
    Oxford University Press (OUP) ; 2013
    In:  Bioinformatics Vol. 29, No. 11 ( 2013-06-01), p. 1416-1423
    In: Bioinformatics, Oxford University Press (OUP), Vol. 29, No. 11 ( 2013-06-01), p. 1416-1423
    Kurzfassung: Motivation: Reverse engineering of gene regulatory networks remains a central challenge in computational systems biology, despite recent advances facilitated by benchmark in silico challenges that have aided in calibrating their performance. A number of approaches using either perturbation (knock-out) or wild-type time-series data have appeared in the literature addressing this problem, with the latter using linear temporal models. Nonlinear dynamical models are particularly appropriate for this inference task, given the generation mechanism of the time-series data. In this study, we introduce a novel nonlinear autoregressive model based on operator-valued kernels that simultaneously learns the model parameters, as well as the network structure. Results: A flexible boosting algorithm (OKVAR-Boost) that shares features from L2-boosting and randomization-based algorithms is developed to perform the tasks of parameter learning and network inference for the proposed model. Specifically, at each boosting iteration, a regularized Operator-valued Kernel-based Vector AutoRegressive model (OKVAR) is trained on a random subnetwork. The final model consists of an ensemble of such models. The empirical estimation of the ensemble model’s Jacobian matrix provides an estimation of the network structure. The performance of the proposed algorithm is first evaluated on a number of benchmark datasets from the DREAM3 challenge and then on real datasets related to the In vivo Reverse-Engineering and Modeling Assessment (IRMA) and T-cell networks. The high-quality results obtained strongly indicate that it outperforms existing approaches. Availability: The OKVAR-Boost Matlab code is available as the archive: http://amis-group.fr/sourcecode-okvar-boost/OKVARBoost-v1.0.zip. Contact:  florence.dalche@ibisc.univ-evry.fr Supplementary information:  Supplementary data are available at Bioinformatics online.
    Materialart: Online-Ressource
    ISSN: 1367-4811 , 1367-4803
    Sprache: Englisch
    Verlag: Oxford University Press (OUP)
    Publikationsdatum: 2013
    ZDB Id: 1468345-3
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Online-Ressource
    Online-Ressource
    Springer Science and Business Media LLC ; 2014
    In:  Scientific Reports Vol. 4, No. 1 ( 2014-08-27)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 4, No. 1 ( 2014-08-27)
    Materialart: Online-Ressource
    ISSN: 2045-2322
    Sprache: Englisch
    Verlag: Springer Science and Business Media LLC
    Publikationsdatum: 2014
    ZDB Id: 2615211-3
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    In: Cell, Elsevier BV, Vol. 159, No. 3 ( 2014-10), p. 676-690
    Materialart: Online-Ressource
    ISSN: 0092-8674
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: Elsevier BV
    Publikationsdatum: 2014
    ZDB Id: 187009-9
    ZDB Id: 2001951-8
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Online-Ressource
    Online-Ressource
    American Association for Cancer Research (AACR) ; 2012
    In:  Clinical Cancer Research Vol. 18, No. 20 ( 2012-10-15), p. 5595-5605
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 18, No. 20 ( 2012-10-15), p. 5595-5605
    Kurzfassung: Purpose: Accurate classification of glioblastoma multiforme (GBM) is crucial for understanding its biologic diversity and informing diagnosis and treatment. The Cancer Genome Atlas (TCGA) project identified four GBM classes using gene expression data and separately identified three classes using methylation data. We sought to integrate multiple data types in GBM classification, understand biologic features of the newly defined subtypes, and reconcile with prior studies. Experimental Design: We used allele-specific copy number data to estimate the aneuploid content of each tumor and incorporated this measure of intratumor heterogeneity in class discovery. We estimated the potential cell of origin of individual subtypes and the euploid and aneuploid fractions using reference datasets of known neuronal cell types. Results: There exists an unexpected correlation between aneuploid content and the observed among-tumor diversity of expression patterns. Joint use of DNA and mRNA data in ab initio class discovery revealed a distinct group that resembles the Proneural subtype described in a separate study and the glioma-CpG island methylator phenotype (G-CIMP+) class based on methylation data. Three additional subtypes, Classical, Proliferative, and Mesenchymal, were also identified and revised the assignment for many samples. The revision showed stronger differences in patient outcome and clearer cell type–specific signatures. Mesenchymal GBMs had higher euploid content, potentially contributed by microglia/macrophage infiltration. Conclusion: We clarified the confusion about the “Proneural” subtype that was defined differently in different prior studies. The ability to infer within-tumor heterogeneity improved class discovery, leading to new subtypes that are closer to the fundamental biology of GBM. Clin Cancer Res; 18(20); 5595–605. ©2012 AACR.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2012
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Online-Ressource
    Online-Ressource
    Springer Science and Business Media LLC ; 2013
    In:  Nature Genetics Vol. 45, No. 10 ( 2013-10), p. 1127-1133
    In: Nature Genetics, Springer Science and Business Media LLC, Vol. 45, No. 10 ( 2013-10), p. 1127-1133
    Materialart: Online-Ressource
    ISSN: 1061-4036 , 1546-1718
    RVK:
    Sprache: Englisch
    Verlag: Springer Science and Business Media LLC
    Publikationsdatum: 2013
    ZDB Id: 1494946-5
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Online-Ressource
    Online-Ressource
    Oxford University Press (OUP) ; 2010
    In:  Bioinformatics Vol. 26, No. 2 ( 2010-01-15), p. 153-160
    In: Bioinformatics, Oxford University Press (OUP), Vol. 26, No. 2 ( 2010-01-15), p. 153-160
    Kurzfassung: Motivation: DNA copy number variants (CNVs) are gains and losses of segments of chromosomes, and comprise an important class of genetic variation. Recently, various microarray hybridization-based techniques have been developed for high-throughput measurement of DNA copy number. In many studies, multiple technical platforms or different versions of the same platform were used to interrogate the same samples; and it became necessary to pool information across these multiple sources to derive a consensus molecular profile for each sample. An integrated analysis is expected to maximize resolution and accuracy, yet currently there is no well-formulated statistical method to address the between-platform differences in probe coverage, assay methods, sensitivity and analytical complexity. Results: The conventional approach is to apply one of the CNV detection (‘segmentation’) algorithms to search for DNA segments of altered signal intensity. The results from multiple platforms are combined after segmentation. Here we propose a new method, Multi-Platform Circular Binary Segmentation (MPCBS), which pools statistical evidence across platforms during segmentation, and does not require pre-standardization of different data sources. It involves a weighted sum of t-statistics, which arises naturally from the generalized log-likelihood ratio of a multi-platform model. We show by comparing the integrated analysis of Affymetrix and Illumina SNP array data with Agilent and fosmid clone end-sequencing results on eight HapMap samples that MPCBS achieves improved spatial resolution, detection power and provides a natural consensus across platforms. We also apply the new method to analyze multi-platform data for tumor samples. Availability: The R package for MPCBS is registered on R-Forge (http://r-forge.r-project.org/) under project name MPCBS. Contact:  nzhang@stanford.edu; junzli@umich.edu Supplementary information:  Supplementary data are available at Bioinformatics online.
    Materialart: Online-Ressource
    ISSN: 1367-4811 , 1367-4803
    Sprache: Englisch
    Verlag: Oxford University Press (OUP)
    Publikationsdatum: 2010
    ZDB Id: 1468345-3
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...