1,721,063 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
Silica-induced fibrosis: from a physiological response in the early metazoans to the well-known pathological outcomes of higher vertebrates
No full text
Effects of urea on zebrafish olfactory organ after environmental exposure.
No full textChronic renal disease is known to alter olfactory function. Of
the uraemic toxins, high urea blood levels have been suspected
to induce a hyposmic condition. However, with the exception of
olfactometric analysis on human subjects, no other examinations
have been conducted, particularly histomorphological
observations of the olfactory organ. Even if hematic administration
could better mimic pathologic conditions, as first
approach we opted for direct nasal exposure, to minimize
potential systemic interference. In this study, we describe the
effects of environmental exposure to elevated concentrations of
urea (7 g/L, 13.5 g/L and 20 g/L) on the sensory mucosa of
zebrafish (considered a good predictive model of mammalian
toxicity) in acute (48h and 96h) and chronic (30 days) toxicity
tests. We observed that lamellae maintained structural
integrity and epithelial thickness was slightly reduced only after
30 days at highest urea concentration. However the ratio
between the volumes of sensory and non-sensory epithelial
regions sensibly decreased during exposure. Pan-neuronal
labelling with anti-Hu was negatively correlated with high doses of urea (13.5 g/L and 20 g/L), thus, we investigated
whether distinct neuron subtypes were equally sensitive to the
toxicant. Using densitometric analysis we evaluated and compared
the immunolabelling of Golf -, TRPC2- and S100-expressing
cells, as representatives of ciliated, microvillous and crypt
neurons, respectively. The three subpopulations responded differently
to urea. In particular, crypt cells were more severely
affected than the other cell types, and Golf -immunoreactivity
increased when fish were exposed to low doses of urea. The
moderate sensory toxicity of urea seems to be in accordance
with the olfactometric measurements reported in the literature.
We counted also the dividing PCNA+-cells, whose density
remained constant: it is possible that other non-neuronal cells
substituted olfactory neurons preserving epithelial integrity
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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