1,721,095 research outputs found
Mutational analysis of the AGL gene: five novel mutations in GSD III patients
No full textTotal or partial lack of glycogen debranching enzyme (GDE or AGL,
amylo-1,6-glucosidase, 4-alpha-glucanotransferase) is responsible for Glycogen
Storage Disease type III (GSDIII), a rare autosomal recessive disorder of
glycogen metabolism. The clinical and biochemical features of GSDIII subjects are
quite heterogeneous, and this mirrors the genotype-phenotype heterogeneity among
patients. In this paper, we report the molecular characterisation of five
unrelated subjects, four Italian and one Tunisian. The following new mutations
are described and confirm the genetic heterogeneity of this disease: p.R864X,
p.R428K, c.3911 insA, p.G1087R and c.3512_3549dup+c.3512_3519del. The functional
relevance of these mutations is discussed on the basis of the recently acquired
knowledge about the boundaries and structures of the two catalytic domains
Molecular characterisation of GSD III subjects and identification of six novel mutations in AGL
No full textDeficiency of amylo-1,6-glucosidase, 4-alpha-glucanotransferase enzyme (AGL or
glycogen debranching enzyme) is causative of Glycogen Storage Disease type III, a
rare autosomal recessive disorder of glycogen metabolism. The disease has been
demonstrated to show clinical and biochemical heterogeneity, reflecting the
genotype-phenotype heterogeneity among different subjects. The aim of this study
was the molecular characterisation of eight unrelated patients from an ethnically
heterogeneous population (six Italians, one from India and another one from
Tunisia). We describe six novel mutations responsible for the disease (C234R,
R675W, 2547delG, T38A, W1327X, IVS6 +3 A>G) and the presence in two Italian
subjects of a splice variant (IVS21(+1) G>A) already described elsewhere. This
last one is confirmed to be the most frequent mutation among the Italian patients
come to our observation, accounting for 28% of 21 patients. One subject was found
to be a compound heterozygous. Our data confirm the substantial genetic
heterogeneity of this disease. Consequently, the strategy of mutation finding
based on screening of recurrent common mutations is limited, as far as regards
Italian GSD III patients, to check for the presence of IVS21(+1) G>A
Leigh disease: Clinical, neuroradiologic, and biochemical study of three new cases with cytochrome c oxidase deficiency
No full textThree cases of Leigh disease are described. In all three, symptoms began in the first months of lire, with muscle hypotonia, lactic acidosis, and psychomotor delay. The diagnosis was made on the basis of the clinical characteristics, biochemical abnormalities, and typical brain magnetic resonance imaging with symmetric lesions suggesting bilateral necrosis at the level of the basal ganglia and of the midbrain. Cytochrome c oxidase (complex IV of the mitochondrial respiratory chain) deficiency was demonstrated in Muscle tissue in all patients and confirmed in skin fibroblasts in patient 3. A genetic heterogeneity was present in these patients since only one had a SURF-1 gene mutation, The clinical, biochemical, and neuroradiologic aspects are discussed. Finally, the finding of facial dysmorphisms in the cytochrome c oxidase deficiency observed in one of the described cases is of extreme interest; to our knowledge, this association has never been reported ill the literature
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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