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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
Cross Talk Between The KNOX And Ethylene Pathways Is Mediated By Intron-Binding Transcription Factors In Barley
No full textKNOX genes play an important role in meristematic activity and correct spatial-temporal regulation is crucial for the development of lateral organs. In barley, duplication of a 305 bp element in intron IV of the Barley knox 3 gene (Bkn3) causes the dominant Hooded (K) phenotype: ectopic expression of Bkn3 in the lemma-awn transition zone leads to the formation of a new meristem that develops into an epiphyillic flower. A screen aimed at isolating putative regulators of the BKn3 gene uncovered 4 proteins capable of interacting with the 305 bp element both in yeast and in vitro - K Intron Binding Proteins (KIBPs). Based on their homology with regulatory proteins involved in ethylene response, we investigated the interactions between two of the KIBP genes, ethylene and Bkn3. Ethylene can partially suppress the K phenotype, upregulate KIBP and downregulate Bkn3 gene expression. Overexpression of barley KIBP genes in rice results in altered expression of an ethylene biosynthesis gene and developmental defects consistent with perturbations in ethylene levels. Reporter-effectors assays in protoplasts indicate that different KIBPs may play contrasting roles in intron-mediated regulation. Together, these results suggest ethylene modulates Bkn3 expression via a complex mechanism involving intron-located sequences and repression/activation by different KIBPs
Isolation and characterization of a new mutant allele of brachytic 2 maize gene
No full textMore than 40 monogenic dwarfing mutants have been described in maize; however, the majority of these lead to great reductions in grain yield and, consequently, they have not been used to enhance crop yield in germplasm that is sensible to lodging. An exception in terms of commercial value is the maize mutant brachytic 2 (br2). Br2 gene was cloned in 2003, and it encodes for a protein most probably involved in auxin polar transport. We have isolated a new brachytic mutation that is allelic to the br2 locus and denoted this novel mutant as br2–23. Characterization of this mutant revealed that the br2 mutation modified not only the length of the internodes, as previously reported, but the structure of the leaves as well. Br2–23/br2–23 heterozygotes have a useful intermediate phenotype in terms of plant height, ear height and leaf angle, suggesting a possible utilization of this effect in developing new hybrids. This mutant also appears to be an useful tool by which to study the switch points of the complex developmental program determining maize plant height and architecture
Candidate gene and functional genomics approaches for the molecular dissection of barley development
No full textVariations 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
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
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