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Proline biosynthesis in Streptococcus thermophilus: characterization of the proBA operon and its products
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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
Proline biosynthesis in Streptococcus thermophilus: characterization of the proBA operon and its products
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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
Proline biosynthesis in Streptococcus thermophilus: Characterization of the proBA operon and its products
No full textThe presence of proline in the medium was not essential for growth of Streptococcus thermophilus, indicating that there is a proline biosynthetic pathway in this organism. Genetic and biochemical analysis identified and characterized this pathway. Two genes, designated proB and proA, were cloned, sequenced and characterized. Biochemical analysis of the proB- and proA-encoded enzymes showed that the proline biosynthetic pathway of S. thermophilus is similar to the one previously described in Escherichia coli. The deduced amino acid sequence of a 2-408 kb DNA region containing the genes revealed the similarity of the S. thermophilus gene products to ProB and ProA of E. coli and Serratia marcescens, and to the corresponding N- and C- terminal domains of the bifunctional plant enzyme delta 1-pyrroline-5- carboxylate synthetase of Vigna aconitifolia. Northern blot analysis showed that the two genes in S. thermophilus are organized in a single operon with proB proximal and proA distal to the promoter; primer extension analysis indicated that proBA transcription is not under repressive control by exogenously supplied proline
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
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