1,720,966 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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Young and Aged Human Muscle Satellite Cells Show Differential Expression of S100B Protein and RAGE.
No full textDuring aging, skeletal muscles show reduced functional capacity due to loss of the regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina
surrounding each myofiber. Both age-related extrinsic factors and age-related intrinsic properties of SCs appear to contribute to SC efficiency (Aging Cell 7 (2008) 590-8). In the present work we analyzed several parameters of SCs derived from biopsies of Vastus Lateralis muscle from healthy non-trained young and aged humans (male and female, divided into young [mean age
31.0 ± 5.35 years; n=7] and aged [mean age 76.44 ± 6.12 years; n=9]). Compared to young SCs, aged SCs showed impaired differentiation, i.e. reduced myotube formation and reduced expression of myogenin and myosin heavy chain when cultured in differentiation medium (DM), and exhibited the following: i) reduced proliferation; ii) higher expression levels of S100B, a Ca2+-binding protein and negative regulator of myoblast differentiation (submitted for publication); iii)
undetectable levels of full-length RAGE (receptor for advanced glycation end products), a multiligand receptor of the immunoglobulin superfamily the engagement of which enhances
myoblast differentiation (Mol Cell Biol 24 (2004) 4880-4894; J Biol Chem 281 (2006) 8242-8253), and presence of a truncated form of RAGE in growth medium (GM) the amount of which
decreased in DM in parallel with appearance of full-length RAGE; and iv) lower expression levels of the transcription factors, MyoD and Pax7, in both GM and DM. Also, transient transfection of
young SCs with S100B expression vector resulted in reduced differentiation compared to controls (i.e., acquisition of an aged phenotype), while either transfection of aged SCs with full-length RAGE expression vector or knocking down S100B by siRNA resulted in enhanced differentiation (i.e., acquisition of a young phenotype). These data point to an important role for intrinsic factors (e.g., MyoD, Pax7, S100B and RAGE) in defective SC function in aged skeletal muscles
Different intrinsic properties of young and aged human satellite cells.
No full textDuring aging, skeletal muscles undergo a decline in functional capacity due to loss of regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina surrounding each myofiber. There is debate about the influence of age-related extrinsic factors on SC efficiency (the SC niche) vs age-related intrinsic cellular properties of the SCs (1).
In the present work we analyzed several parameters of SCs derived from biopsies from Vastus Lateralis muscle from both healthy non-trained young and aged humans [male and female, divided into young (mean age 31.6 ± 3.6 years; n=5) and aged (mean age 77.3 ± 5.8 years; n=7)].
Aged SCs showed impaired differentiation ability [i.e., lower extent of fusion into myotubes and reduced expression of myogenin and myosin heavy chain, when cultured in differentiation medium (DM)], compared with young SCs, and were characterized by the following: i) a stronger expression of S100B, a Ca2+-binding protein the overexpression of which has been found to interfere with myoblast differentiation (Tubaro C et al., submitted for publication); ii) undetectable levels of full-length RAGE (receptor for advanced glycation end products) protein, a multiligand receptor the engagement of which enhances myoblast differentiation (2), in growth medium (GM), and cytosolic instead of membrane localization of RAGE in DM; and iii) lower expression levels of MyoD and Pax7 transcription factors, in both GM and DM.
These data point to an important role for intrinsic factors, besides extrinsic factors, in defective SC function during aging
FUNCTIONAL CHARACTERIZATION OF MUSCLE FIBRES FROM PATIENTS WITH CHRONIC FATIGUE SYNDROME: CASE-CONTROL STUDY
No full textChronic fatigue syndrome (CFS) is a disabling condition characterized by unexplained chronic fatigue that impairs normal activities. Although immunological and psychological aspects are present, symptoms related to skeletal muscles, such as muscle soreness, fatigability and increased lactate accumulation, are prominent in CFS patients. In this case-control study, the phenotype of the same biopsy samples was analyzed by determining i) fibre-type proportion using myosin isoforms as fibre type molecular marker and gel electrophoresis as a tool to separate and quantify myosin isoforms, and ii) contractile properties of manually dissected, chemically made permeable and calcium-activated single muscle fibres. The results showed that fibre-type proportion was significantly altered in CSF samples, which showed a shift from the slow- to the fast-twitch phenotype. Cross sectional area, force, maximum shortening velocity and calcium sensitivity were not significantly changed in single muscle fibres from CSF samples. Thus, the contractile properties of muscle fibres were preserved but their proportion was changed, with an increase in the more fatigue-prone, energetically expensive fast fibre type. Taken together, these results support the view that muscle tissue is directly involved in the pathogenesis of CSF and it might contribute to the early onset of fatigue typical of the skeletal muscles of CFS patients
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