1,720,969 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
Immunoreactivity of antibodies against transglutaminase-deamidated gliadins in adult celiac disease
No full textBackground The significance of the presence of anti-gliadin antibodies in patients affected by celiac disease is still unclear. It is hypothesized that gliadin deamidation, catalysed by transglutaminase, plays a role in favoring the antigen presentation. Aim To determine the immunoreactivity of anti-gliadin antibodies from untreated celiac patients to transglutaminase deamidated gliadins. Materials and methods Gliadins from wheat flour underwent enzymatic digestion and were deamidated or cysteamine-transamidated by transglutaminase. Immunoreactivity of anti-gliadin antibodies from untreated adult celiac patients sera was evaluated by means of a competitive enzyme-linked immunosorbent assay (ELISA) method. Results Gliadin deamidation increased antibodies immunoreactivity from 25% to 50% while cysteamine incorporation into the gliadin peptides resulted in an immunoreactivity decrease. Conclusions Increased immunoreactivity of transglutaminase deamidated gliadins tested with anti-gliadin antibodies from untreated adult celiac patients supports the hypothesis of a pivotal role of gliadin deamidation in the pathomechanism of celiac disease
Resveratrol induced inhibition of cholangiocarcinoma cell growth is transglutaminase dependent
No full textINTRODUCTION/OBJECTIVES: Cholangiocarcinoma is a tumour with a poor prognosis. An efficient therapy is unavailable in unoperable patients and new drugs are widely requested. Resveratrol (RES) is a natural molecule with a well known anticancer effect proved on different tumour cell lines. Previous studies demonstrated the cytotoxic effect of RES on cholangiocarcinoma cell cultures [1] and the related increase of transglutaminase type 2 (TG2), which is involved in carcinogenesis and apoptosis.
AIMS & METHODS: Aim of the present study was to evaluate if the cytotoxic effect of RES on cholangiocarcinoma cell lines could be abolished by TG inhibition.
Cholangiocarcinoma cell lines (SK-CHA-1 and MZ-CHA-1), growth in a three dimensional
cell culture systems, have been treated for 72 hours with RES (32, 64 microM) alone or combined with three different TG2 inhibitors: cystamine and the selective inhibitors B003 and T101. At the end of the treatments we investigated:
(1) cells viability (clonigenic test); (2) cell morphology with light microscopy on
histological sections and electron microscopy (TEM); 3) TG2 activity (colorimetric technique).
RESULTS: RES treatment induced a significant inhibition of cell growth (90% and 62% vs 100% controls). The cotreatement RES/TG2 inhibitors prevented these growth
inhibition in both cell lines; the cell growth for MZ-CHA-1 at higher dose of RES was
respectively (cystammine, B003 and T101) 50%, 60% and 90% vs. 100% controls; for SK-CHA-1 (cystammine, B003 and T101) was 55%, 60% and 80% vs. 100% controls. Histological sections and TEM results demonstrated a partial protection with both cystammine and B003/T101 inhibitors. The normalization of cell growth was associated to an inhibition of TG2 activity both in MZ-CHA-1 (60% with cystamine, 80% with B003 and 90% with T101 vs. 100% controls) and SK-CHA-1 (20% with
cystammine, 40% with B003 and 60% with T101 vs. 100% controls).
CONCLUSION: Our data demonstrated that the cytotoxic effect of RES in SK-CHA-1 and MZ-CHA-1 is TG2 mediated.
REFERENCE(S): [1] Roncoroni et al. Liver Int. 2008;10:1426−36.
Disclosure of Interest: None Declared
Cytotoxic and cytogenetic analysis in a human cholangiocarcinoma after resveratrol treatment
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