59 research outputs found
GeneSigDB: a manually curated database and resource for analysis of gene expression signatures
GeneSigDB (http://www.genesigdb.org or http://compbio.dfci.harvard.edu/genesigdb/) is a database of gene signatures that have been extracted and manually curated from the published literature. It provides a standardized resource of published prognostic, diagnostic and other gene signatures of cancer and related disease to the community so they can compare the predictive power of gene signatures or use these in gene set enrichment analysis. Since GeneSigDB release 1.0, we have expanded from 575 to 3515 gene signatures, which were collected and transcribed from 1604 published articles largely focused on gene expression in cancer, stem cells, immune cells, development and lung disease. We have made substantial upgrades to the GeneSigDB website to improve accessibility and usability, including adding a tag cloud browse function, facetted navigation and a ‘basket’ feature to store genes or gene signatures of interest. Users can analyze GeneSigDB gene signatures, or upload their own gene list, to identify gene signatures with significant gene overlap and results can be viewed on a dynamic editable heatmap that can be downloaded as a publication quality image. All data in GeneSigDB can be downloaded in numerous formats including .gmt file format for gene set enrichment analysis or as a R/Bioconductor data file. GeneSigDB is available from http://www.genesigdb.org
An international standardization programme towards the application of gene expression profiling in routine leukaemia diagnostics: the Microarray Innovations in LEukemia study prephase
Gene expression profiling has the potential to enhance current methods for the diagnosis of haematological malignancies. Here, we present data on 204 analyses from an international standardization programme that was conducted in 11 laboratories as a prephase to the Microarray Innovations in LEukemia (MILE) study. Each laboratory prepared two cell line samples, together with three replicate leukaemia patient lysates in two distinct stages: (i) a 5-d course of protocol training, and (ii) independent proficiency testing. Unsupervised, supervised, and r2 correlation analyses demonstrated that microarray analysis can be performed with remarkably high intra-laboratory reproducibility and with comparable quality and reliability
Mass segregation in young compact star clusters in the Large Magellanic Cloud: I. Data and Luminosity Functions
We have undertaken a detailed analysis of HST/WFPC2 and STIS imaging
observations, and of supplementary wide-field ground-based observations
obtained with the NTT of two young ~10-25 Myr) compact star clusters in the
LMC, NGC 1805 and NGC 1818. The ultimate goal of our work is to improve our
understanding of the degree of primordial mass segregation in star clusters.
This is crucial for the interpretation of observational luminosity functions
(LFs) in terms of the initial mass function (IMF), and for constraining the
universality of the IMF.
We present evidence for strong luminosity segregation in both clusters. The
LF slopes steepen with cluster radius; in both NGC 1805 and NGC 1818 the LF
slopes reach a stable level well beyond the clusters' core or half-light radii.
In addition, the brightest cluster stars are strongly concentrated within the
inner ~4 R_hl.
The global cluster LF, although strongly nonlinear, is fairly well
approximated by the core or half-light LF; the (annular) LFs at these radii are
dominated by the segregated high-luminosity stars, however.
We present tentative evidence for the presence of an excess number of bright
stars surrounding NGC 1818, for which we argue that they are most likely
massive stars that have been collisionally ejected from the cluster core. We
therefore suggest that the cores of massive young stars clusters undergo
significant dynamical evolution, even on time-scales as short as ~25 Myr.Comment: 19 pages, incl. 10 embedded postscript figures, MNRAS, resubmitted
(referee's comments included
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