1,720,986 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
COMPLETE NUCLEOTIDE-SEQUENCE OF ONE MEMBER OF THE SORGHUM PHOSPHOENOLPYRUVATE CARBOXYLASE GENE FAMILY
No full textPRODUCTION AND PROPERTIES OF RECOMBINANT C3-TYPE PHOSPHOENOLPYRUVATE CARBOXYLASE FROM SORGHUM-VULGARE - IN-VITRO PHOSPHORYLATION BY LEAF AND ROOT PYRPC PROTEIN-SERINE KINASES
No full textIn this work, the C3-type form of Sorghum phosphoenolpyruvate carboxylase (PyrPC) was produced in PyrPC-deficient strains of Escherichia coli transformed by a plasmid bearing the corresponding full-length cDNA (CPR1). The full-sized protein was purified to homogeneity by immunoaffinity chromatography. Some functional and regulatory properties were described; notably, the immunopurified PyrPC could be phosphorylated in reconstituted assay by 1) both a mammalian PKA and the PyrPC protein serine kinase purified from Sorghum leaves and 2) a novel protein kinase affinity-purified from Sorghum roots. In all cases phosphorylation was accompanied by a marked reduction in its malate sensitivity
THE PHOSPHOENOLPYRUVATE CARBOXYLASE GENE FAMILY OF SORGHUM - PROMOTER STRUCTURES, AMINO-ACID-SEQUENCES AND EXPRESSION OF GENES
No full textTwo different members of the phosphoenolpyruvate carboxylase(PEPC)-encoding multigene family (clones lambda-CP21 and lambda-CP46) have been isolated from a Sorghum vulgare lambda-EMBL4 genomic library. The use of the 3'-noncoding regions to probe Northern blots of RNA from roots, etiolated leaves and green leaves indicated that lambda-CP21 and lambda-CP46 encode the C3- and C4-type leaf PEPC isoforms, respectively. The lambda-CP21 clone is expressed in the three tissues and is not light-regulated, whereas lambda-CP46 is only expressed in greening leaves. The nucleotide sequence of the 5'-flanking DNA (520 bp) has been determined for both genes. For lambda-CP46, several direct repeats were located in this region with similarities to sequences found in other light-regulated genes, but not in lambda-CP21. The deduced amino acid sequences of the two S. vulgare PEPC proteins are 75% identical
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
PRODUCTION IN ESCHERICHIA-COLI OF ACTIVE SORGHUM PHOSPHOENOLPYRUVATE CARBOXYLASE WHICH CAN BE PHOSPHORYLATED
No full textPhosphoenolpyruvate carboxylase (PEPC)-deficient mutants of Escherichia coli have been complemented with a plasmid bearing a full-length cDNA encoding the C4-type form of Sorghum leaf PEPC. Transformed cells grew on minimal medium. Two clones were selected which produce a functional and full-sized enzyme protein as determined by activity assays, immunochemical behavior and SDS-PAGE. In addition, regulatory phosphorylation of immunopurified recombinant PEPC was observed when the enzyme was incubated with a partially purified plant PEPC kinase. These results establish that E. coli cells produce a genuine, phosphate-free, higher-plant PEPC. Application of immunoadsorbtion chromatography to bacterial extracts makes it possible to prepare highly pure protein available for biochemical studies. RI Vidal, Jean/A-8881-2008; Lepiniec, Loic/G-5808-201
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