1,720,992 research outputs found
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
Effect of 12 years of enzyme replacement therapy on plasma and urine glycosaminoglycans in attenuated Mucopolysaccharidosis I patients
Full text linkBackgroung
To date, only few data are available on the capacity of ERT at standard doses to definitively eliminate pathological glycosaminoglycans (GAGs). We report a characterization of urine and plasma GAGs performed in order to assess the effect of ERT after 12 years in two attenuated MPS I siblings.
Case Study or Methods
The brother (sibling1) commenced weekly laronidase infusions at a dose of 0.5 mg/kg at the age of 5 months and the sister (sibling 2) at the age of 5 years, shortly after the diagnosis. Urine samples were analyzed by DMB and electrophoretic methods. Plasma GAG disaccharides were evaluated by HPLC.
Results
Sibling 1. Total urinary GAGs excretion was slightly above the upper normal limits for age during the last 6 years. Urinary GAGs electrophoresis showed the presence of DS and CS with a ratio of about 50/50. Plasma GAGs before ERT were 18.2 μg/ml (nv 5.2 ± 3.01) with a CS/DS ratio of 25/75 (nv 100/0). After 12 years of ERT, plasma GAGs have remained within the normal range for age, with traces of DS.
Sibling2. Total urinary GAGs excretion was elevated before ERT and normalized after 4 months of therapy until 8.5 years of age. At the age of 10.5 years GAGs levels increased to 89 μg/creat (nv 37 ± 18) and subsequently normalized. Urinary GAGs were characterized by the presence of DS and HS before ERT and normalized after 4 months of ERT up to the age of 6 years when a ratio of 50/50 of DS/CS was observed. Plasma GAGs at the age of 11.5 years were 2.8 μg/ml (nv 2.7 ± 1.12) with a CS/DS ratio of 98/2 (nv 100/0).
Discussion
Biochemical observation of these siblings reveals a moderate increase of total urinary GAGs and more notably DS later in childhood. Normal levels of plasmatic GAGs were observed with only traces of DS. No abnormal levels of HS present before ERT were detected in urine and plasma. Based on the present results, we can suppose that the amount of supplied enzyme could contribute to the insufficient GAGs degradation
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
Coenzyme Q_(10) and oxidative imbalance in Down syndrome: biochemical and clinical aspects.
No full textDown syndrome (DS) is a chromosomal abnormality (trisomy 21) associated with mental retardation and Alzheimer-like dementia, characteristic change of the individual's phenotype and premature ageing. Oxidative stress is known to play a major role in this pathology since a gene dose effect leads to elevated ratio of superoxide dismutase to catalase/glutathione peroxidase compared to controls in all age categories suggesting that oxidative imbalance contributes to the clinical manifestation of DS. Hyperuricemia is another feature of DS that has an interesting relationship with oxidative stress since uric acid represents an important free radical scavenger. However its formation is connected to the conversion of Xanthine dehydrogenase (XDH) to Xanthine oxidase (XO) which leads to concomitant production of free radicals. Here we report that plasma samples from DS patients in pediatric age, despite an increased total antioxidant capacity, largely due to elevated Uric acid content (UA), present significantly elevated markers of oxidative damage such as increased allantoin levels. Moreover DS plasma samples do not differ from healthy control ones in terms of Coenzyme Q10 and susceptibility to peroxidative stimuli. On the contrary, lymphocyte and platelet CoQ10 content was significantly lower in DS patients, a fact that might underlie oxidative imbalance at a cellular level
Metabolic fate of human milk oligosaccharides in four different group of milk in breastfed infants
No full textoral communicatio
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