1,720,972 research outputs found
Transient neonatal diabetes, a disorder of imprinting
No full textTransient neonatal diabetes (TND) is a rare but distinct type of diabetes. Classically, neonates present with growth retardation and diabetes in the first week of life. Apparent remission occurs by 3 months but there is a tendency for children to develop diabetes in later life. Evidence suggests it is the result of overexpression of an imprinted and paternally expressed gene/s within the TND critical region at 6q24. Two imprinted genes, ZAC (zinc finger protein associated with apoptosis and cell cycle arrest) and HYMAI (imprinted in hydatidiform mole) have been identified as potential candidates. Three genetic mechanisms have been shown to result in TND, paternal uniparental isodisomy of chromosome 6, paternally inherited duplication of 6q24, and a methylation defect at a CpG island overlapping exon 1 of ZAC/HYMAI
An imprinted locus associated with transient neonatal diabetes mellitus
No full textRecently, we reported the localization of a gene for transient neonatal diabetes mellitus (TNDM), a rare form of childhood diabetes, to an approximately 5.4 Mb region of chromosome 6q24. We have also shown that TNDM is associated with both paternal uniparental disomy (UPD) of chromosome 6 and paternal duplications of the critical region. The sequencing of P1-derived artificial chromosome clones from within the region of interest has allowed us to further localize the gene and to investigate the methylation status of the region. The gene is now known to reside in a 300-400 kb region of 6q24 which contains several CpG islands. At one island we have demonstrated differential DNA methylation between patients with paternal UPD of chromosome 6 and normal controls. In addition, two patients with TNDM, in whom neither paternal UPD of chromosome 6 nor duplication of 6q24 have been found, show a DNA methylation pattern identical to that of patients with paternal UPD of chromosome 6. Control individuals show a hemizygous methylation pattern. These results show that TNDM can be associated with a methylation change and identify a novel methylation imprint on chromosome 6 associated with TNDM.</p
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
Analysis of the imprinted transient neonatal diabetes critical region (ZAC/HYMAI) locus in Type 2 diabetes parent-offspring trios
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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
Letter to the editor: Observation. Complete glucokinase deficiency is not a common cause of permanent neonatal diabetes
No full textDispelling 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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