1,721,112 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
Molecular detection of novel astroviruses in wild and laboratory mice
No full textPooled fecal specimens collected from striped field mice (Apodemus agrarius), yellow-necked mice (Apodemus flavicollis), and bank voles (Myodes glareolus) and individual stool samples collected from laboratory mice were tested for the presence of picornaviruses and astroviruses. Picornavirus RNA was detected only in one striped field mouse sample pool, while astrovirus RNA was detected in two yellow-necked mouse sample pools and in six of the 121 laboratory mouse samples. In a 234-amino acid (aa) fragment of the viral RNA dependent RNA polymerase (RdRp), the wild mouse picornavirus revealed the closest homology to the canyon mouse (Peromyscus crinitus) (93 % aa) and canine kobuviruses (92 % aa) and to Aichi virus (88 % aa). The two astroviruses detected in the yellow-necked mouse samples shared 77 % aa homology with each other in the partial (125 aa) RdRp region, 61-62 % aa homology with rat astroviruses and only 54-58 % aa homology with the house mouse (Mus musculus) astrovirus strain USA/2008/M52. The six laboratory mouse astroviruses displayed 97-100 % aa homology to each other, and shared 71-77 % aa homology with the yellow-necked mouse astroviruses, 58-59 % aa homology with rat astroviruses and 55-56 % aa homology with strain USA/2008/M52. The sequence of a 3,263 bp genome segment including the partial ORF1b (RdRp), complete ORF2 (capsid precursor), and 3' NTR of a research mouse astrovirus strain (TF18LM) was determined. The full-length ORF2 showed low identities (17-34 % aa) with other members of the Mamastrovirus genus and only 17 % aa homology with the house mouse astrovirus strain USA/2008/M52, indicating that AstVs described in this study represent a novel Mamastrovirus species. The relevance of astrovirus infection and its effect on biomedical research conducted in mice needs to be investigate
Molecular detection of murine noroviruses in laboratory and wild mice
No full textFecal specimens collected from 121 laboratory mice, 30 striped field mice (Apodemus agrarius), 70 yellow-necked mice (Apodemus flavicollis), and 3 bank voles (Myodes glareolus) were tested in sample pools for the presence of murine noroviruses (MNV). Ten of 41 laboratory mice and 2 of 3 striped field mice pooled samples were positive for MNV. All laboratory mouse MNVs were closely related to previously described MNVs. The complete ORF2 (VP1) of both striped field mouse MNVs identified in this study was 1623 nt (541 aa) long and differed at 12% nt (8% aa) positions from each other, at 22-24% nt (15-18% aa) positions from the laboratory mouse MNVs and at 20-22% nt (13-14% aa) positions from the recently described wood mouse (Apodemus sylvaticus) MNVs. This study provides further evidence for the circulation of novel, genetically diverse MNVs in wild mic
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
Separation of enantiomers of chiral sulfoxides in high-performance liquid chromatography with cellulose-based chiral selectors using acetonitrile and acetonitrile-water mixtures as mobile phases
No full textThe separation of 14 chiral sulfoxides was systematically studied on 12 cellulose-based chiral columns in acetonitrile and acetonitrile-water mobile phases. Out of all monosubstituted methylphenylcarbamates of cellulose the one having a methyl moiety in position 3 showed more universal chiral resolving ability compared to 2- and 4-substituted derivatives. Out of disubstituted phenylcarbamates of cellulose the ones with methyl substituents showed higher enantiomer resolving ability compared to chloro-substituted ones and substitution in positions 3 of the phenyl moiety was clearly advantageous. From disubstituted derivatives those possessing a combination of methyl- and chloro-substituents were advantageous compared to the ones having dimethyl- or dichloro-substituents. Chiral recognition ability of most chiral selectors towards studied sulfoxides was higher in pure acetonitrile compared to previously studied methanol. The effect of water addition to the mobile phase on analyte retention and enantioseparation was also quite different from that observed with methanol. In particular, with aqueous methanol by increasing the water content in the mobile phase retention increased in most cases and the separation factor improved. In contrast, with aqueous acetonitrile retention and separation factors decreased up to a certain water content in the mobile phase and then started to recover again for most of the studied analytes
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
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