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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
Fetal forms of oligoaminopeptidase, dipeptidylaminopeptidase IV, and sucrase in human intestine and meconium.
No full textParticles of meconium sedimenting at 105,000 g contain sucrase and various brush border peptidase activities. Oligoaminopeptidase, dipeptidylaminopeptidase, and sucrase solubilized by papain from meconium particles of preterm newborns or from brush border of human fetuses during the 4th month of gestation were compared with the same enzymes prepared from adult jejunal and ileal brush border. The following are characteristics of fetal intestinal brush border enzymes: (a) a faster anodal electrophoretic mobility in polyacrylamide and in agar gel; (b) the same specific activity, as measured by quantitative crossed immunoelectrophoresis utilizing an antiserum against adult brush border membranes; (c) complete fusion of the immunoprecipitation lines with the adult enzymes by using the same antiserum; and (d) a different binding pattern to Helix pomatia lectin and lentil lectin. The results suggest that the charge difference between adult and fetal human brush border enzymes, which causes the difference in the gel electrophoretic mobility, is most probably due, at least in part, to differences in carbohydrate composition of these glycoproteins. Extensive neuraminidase digestion causes no or only minor changes of the electrophoretic mobility of the meconial enzymes. The difference between adult and meconial enzymes is therefore apparently not, or not only, due to different sialic acid content. These results suggest that many intestinal brush border enzymes in fetal life and at birth are in forms structurally different from those in adult life
Glycopeptide alterations induced by 12-O-tetradecanoyl phorbol-13-acetate in chick embryo cultured myotubes.
No full textThe tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA) specifically inhibits the expression of differentiative traits in cultured chick embryo myotubes, without inducing them to reenter the cell cycle. We evaluated the effect of TPA on glycoconjugate synthesis in cultured myotubes under various experimental conditions. Radioactively labelled glycoconjugates were obtained by labelling control and TPA treated cultured myotubes with radioactive monosaccharides. After chloroform-methanol extraction and extensive pronase digestion, the glycoconjugates were separated on the basis of size on Sephadex G 50 columns. A relative enrichment in larger glycopeptides was induced by TPA treatment of myotubes for 24 or 48 h. Glycopeptide groups were further analyzed by affinity chromatography on ConA Sepharose columns. A marked and reproducible decrease in the affinity of medium size glycopeptides for ConA was observed as a result of TPA treatment of cultured myotubes. These modifications are reversible upon removal of the tumor promoter from the culture medium of pretreated myotubes. The reported effects of TPA, closely resembling those occurring in transformed cells, appear to be due to structural modifications of glycopeptides whose mechanism and role in transformation and modulation of differentiation 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
Submandibular gland’s adenoid cystic carcinoma: case report and review of the literature
No full textAppropriate 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
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