1,720,982 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
CAVEOLINS AND CAVINS IN MUSCLE-DERIVED TUMOURS
No full textRhabdomyosarcomas (RMS) are muscle-derived tumours with a significant incidence in children. RMS cells exhibit a widespread pattern of muscle-specific markers, the detection of which may be useful for discriminating the tumour grading in order to optimize the timing and doses of chemotherapy. By analyzing human RMS specimens and in vitro cell lines, we determined the time window of expression of Caveolins (Cav-1, -2 and -3) and some Cavins family members (i.e. PTRF/Cavin-1 and MURC/Cavin-4). In detail, the simultaneous expression of Cav-1, Cav-2 and PTRF/Cavin-1 defined a signature predictive of immature cells, whereas the expression of Cav-3 and MURC/Cavin-4 was restricted to cells more differentiated. In addition, in immature cells Cav-1 was tyrosine-phosphorylated in a Src-dependent manner, resulting in increased cell proliferation and migration. As a result, the subcutaneous injections into nude mice of RMS cells overexpressing the wild-type Cav-1 form promoted a significant tumour growth, which was instead prevented by the injection of cells expressing a non-phosphorylatable Cav-1 form.
Overall, it can be concluded that Caveolins and Cavins can be useful to identify the degree of cellular differentiation in RMS and that phosphorylation of Cav-1, in particular, plays a key role in tumour aggressiveness
Melatonin action in tumor skeletal muscle cells: An ultrastructural study
No full textMelatonin (Mel), or N-acetyl-5-methoxytryptamine, is a circadian hormone that can diffuse through all the biological membranes thanks to its amphiphilic structure, also overcoming the blood-brain barrier and placenta. Although Mel has been reported to exhibit strong antioxidant properties in healthy tissues, studies carried out on tumor cultures gave a different picture of its action, often describing Mel as effective to trigger the cell death of tumor cells by enhancing oxidative stress.Based on this premise, here Mel effect was investigated using a tumor cell line representative of the human alveolar rhabdomyosarcoma (ARMS), the most frequent soft tissue sarcoma affecting childhood. For this purpose, Mel was given either dissolved in ethanol (EtOH) or dimethyl sulfoxide (DMSO) at different concentrations and time exposures. Cell viability assays and ultrastructural observations demonstrated that Mel was able to induce a dose- and time-dependent cell death independently on the dissolution solvent. Microscopy analyses highlighted the presence of various apoptotic and necrotic patterns correlating with the increasing Mel dose and time of exposure. These findings suggest that Mel, triggering apoptosis in ARMS cells, could be considered as a promising drug for future multitargeted therapies
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
Melatonin action in tumor skeletal muscle cells: an ultrastructural study
No full textMelatonin (Mel), or N-acetyl-5-methoxytryptamine, is a circadian hormone that can diffuse through all the biological membranes thanks to its amphiphilic structure, also overcoming the blood-brain barrier and placenta. Although Mel has been reported to exhibit strong antioxidant properties in healthy tissues, studies carried out on tumor cultures gave a different picture of its action, often describing Mel as effective to trigger the cell death of tumor cells by enhancing oxidative stress. Based on this premise, here Mel effect was investigated using a tumor cell line representative of the human alveolar rhabdomyosarcoma (ARMS), the most frequent soft tissue sarcoma affecting childhood. For this purpose, Mel was given either dissolved in ethanol (EtOH) or dimethyl sulfoxide (DMSO) at different concentrations and time exposures. Cell viability assays and ultrastructural observations demonstrated that Mel was able to induce a dose- and time-dependent cell death independently on the dissolution solvent. Microscopy analyses highlighted the presence of various apoptotic and necrotic patterns correlating with the increasing Mel dose and time of exposure. These findings suggest that Mel, triggering apoptosis in ARMS cells, could be considered as a promising drug for future multitargeted therapies
Caveolins and cavins in muscle-derived tumours.
No full textRhabdomyosarcomas (RMS) are muscle-derived tumours with a significant incidence in children. RMS cells exhibit a widespread pattern of muscle-specific markers, the detection of which may be useful for discriminating the tumour grading in order to optimize the timing and doses of chemotherapy. By analyzing human RMS specimens and in vitro cell lines, we determined the time window of expression of Caveolins (Cav-1, -2 and -3) and some Cavins family members (i.e. PTRF/Cavin-1 and MURC/Cavin-4). In detail, the simultaneous expression
of Cav-1, Cav-2 and PTRF/Cavin-1 defined a signature predictive of immature cells, whereas the expression of Cav-3 and MURC/Cavin-4 was restricted to more differentiated cells. In
addition, in immature cells Cav-1 was tyrosine-phosphorylated in a Src-dependent manner, resulting in increased cell proliferation and migration. As a result, the subcutaneous injections
into nude mice of RMS cells overexpressing the wild-type Cav-1 form resulted in a significant tumour growth, which was instead prevented by the over-expression of a non-phosphorylatable form of Cav-1. Overall, it can be concluded that Caveolins and Cavins can be useful to identify the degree of cellular differentiation in RMS and that phosphorylation of Cav-1, in particular, plays a key role in tumour aggressiveness
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