1,721,001 research outputs found
X linked Charcot-Marie-Tooth disease (CMTX1): a study of 15 families with 12 highly informative polymorphisms.
No full textX linked dominant Charcot-Marie-Tooth disease (CMTX1) has previously been localised to Xq13-21. Fifteen families were studied using 12 highly informative polymorphisms in the pericentric region of the X chromosome. Phase known recombinations in these families localise the X linked dominant CMT gene to the region distal to DXS106 (Xq11.2-12) and proximal to DXS559 (Xq13.1). These markers flank approximately 2 to 3 Mb of DNA to which GJB1 and CCG1 have already been mapped. A recent report of mutations in the GJB1 gene in subjects with CMTX1 makes this a strong candidate gene
Mutations in the connexin 32 gene in X-linked dominant Charcot-Marie-Tooth disease (CMTX1)
No full textX-linked dominant Charcot-Marie-Tooth disease (CMTX1) is a peripheral neuropathy which maps to Xq13 and is flanked by the loci DXS106 (Xq11.2-q12) and DXS559 (Xq13.1). Contained within this interval of approximately 2-3Mb of DNA is the gene, connexin 32 (locus designation GJ beta 1). This gene encodes a gap junction protein which is expressed in large quantities within the liver and throughout a range of other mammalian tissues. We have sequenced the coding region of exon 2 of this gene from affected individuals in nine families with CMTX 1 and have found mutations which segregate with the disease in eight of these families. The mutations detected include missense point mutations at codons 15, 60, 63, 208, and 215, a nonsense point mutation at codon 220, deletions of one base in codon 72/3 producing a stop codon 12 codons down stream and a three base pair deletion which can be predicted to result in the loss of a single amino acid. These findings are consistent with the disease CMTX1 being the result of mutations affecting the gene connexin 32 (Cx32)
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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