1,720,959 research outputs found
A novel resource for the study of genes expressed in the adult human retina
No full textPURPOSE:
To reconstruct the transcriptional profile of the human adult retina and the genomic map of the genes expressed in this tissue.
METHODS:
Original software was used for the retrieval and analysis of records from UniGene (http://www.ncbi.nlm.nih. gov/UniGene/) pertaining to selected cDNA libraries from adult human retina.
RESULTS:
The 4974 genes reported so far to be expressed in retina were included in a catalog available on the Internet. For each entry, an estimation of the level of expression of the corresponding gene in the retina was provided. A high-resolution genomic map of the human retina was built up by inclusion of 3152 genes showing a precise and unique map assignment. The correspondence was established between 53 gene-orphan retinal diseases and clusters of genes expressed in the retina.
CONCLUSIONS:
The in silico reconstruction of the transcriptional profile of the adult human retina provides preliminary information on the pattern of genomic expression in this tissue. The chromosomal location of many retinal genes, combined with their expression data, should speed up the identification of genes involved in retinal diseases
A computational reconstruction of the adult human heart transcriptional profile
No full textThe reconstruction of the transcriptional profile of the adult human heart was attempted, by applying a bioinformatic and computational approach to UniGene data. A catalogue of 2077 expressed genes was produced. Over 1000 entries of the catalogue corresponded to putative novel genes. Highly expressed genes accounted for about 20% of the total. Almost all genes expressed in adult heart resulted to be active in at least one additional tissue and about 90% were found in over five additional tissues. A genomic map of 1364 genes expressed in heart, which also indicated chromosomal location, was produced, which could be conveniently used for the discovery of the determinants of gene-orphan heart diseases and for the detection of clusters of highly expressed genes. The catalogue and the genomic map of genes expressed in adult human heart are available on Internet at the sites: http://telethon.bio.unipd.it/GETProfiles/heart and http://telethon.bio.unipd.it/GETMaps/heart
The human adult skeletal muscle transcriptional profile reconstructed by a novel computational approach
Full text linkBy applying a novel software tool, information on 4080 UniGene clusters was retrieved from three adult human skeletal muscle cDNA libraries, which were selected for being neither normalized nor subtracted. Reconstruction of a transcriptional profile of the corresponding tissue was attempted by a computational approach, classifying each transcript according to its level of expression. About 25% of the transcripts accounted for about 80% of the detected transcriptional activity, whereas most genes showed a low level of expression. This in silico transcriptional profile was then compared with data obtained by a SAGE study. A fairly good agreement between the two methods was observed. About 400 genes, highly expressed in skeletal muscle or putatively skeletal muscle-specific, may represent the minimal set of genes needed to determine the tissue specificity. These genes could be used as a convenient reference to monitor major changes in the transcriptional profile of adult human skeletal muscle in response to different physiological or pathological conditions, thus providing a framework for designing DNA microarrays and initiating biological studies
IDEG6: a web tool for detection of differentially expressed genes in multiple tag sampling experiments
No full textHere we present a novel web tool for the statistical analysis of gene expression data in multiple tag sampling experiments. Differentially expressed genes are detected by using six different test statistics. Result tables, linked to the GenBank, UniGene, or LocusLink database, can be browsed or searched in different ways. Software is freely available at the site: http://telethon.bio.unipd.it/bioinfo/IDEG6_form/, together with additional information on statistical methodologies
Differential expression of genes coding for ribosomal proteins in different human tissues
No full textMOTIVATION: To perform a computational and statistical study on a large set of gene expression data pertaining six adult human tissues (brain, liver, skeletal muscle, ovary, retina and uterus) for analyzing the expression of ribosomal protein genes.
RESULTS: Unexpectedly, in each of the considered tissues large variations in the expression of ribosomal protein genes were observed. Moreover, when comparing the expression levels of 89 ribosomal protein genes in six different tissues, 13 genes appeared differentially expressed among tissues.
AVAILABILITY: The expression data of the ribosomal protein genes together with supplementary material (complete transcriptional profiles of the considered human tissues) are freely available at the site GETProfiles (http://telethon.bio.unipd.it/GETProfiles/)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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