1,720,964 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
New Ordovician marine macroalgae from North America, with observations on Buthograptus, Callithamnopsis, and Chaetocladus
No full textOrdovician material from the Platteville Formation (Sandbian) of southern Wisconsin and Big Hill Formation (Katian) of northern Michigan is described that provides novel information about the phylogenetic affinity, taxonomic diversity, and stratigraphic range of the nonbiomineralized taxa Buthograptus, Callithamnopsis, and Chaetocladus. Two new species of Buthograptus, a previously monotypic genus, are erected on the basis of the Platteville Formation material, Buthograptus gundersoni n. sp. and B. meyeri n. sp., and new occurrences of B. laxus are recorded from several localities and two distinct stratigraphic levels within this unit. On the basis of scanning electron microscopic investigation of the material and the fact that each of the three Buthograptus species has a close counterpart in the frond morphology of an extant species of Caulerpa, Buthograptus is interpreted as a member of the green algal order Bryopsidales. New specimens from the Platteville Formation assigned to Callithamnopsis reveal new morphological details for the type species, C. fruticosa (Hall, 1865), aspects of which indicate that the genus belongs to the family Triploporellaceae rather than Seletonellaceae within the green algal order Dasycladales, and Chaetocladus material from the Big Hill Formation includes specimens that are formally assigned to Chaetocladus dubius (Spencer, 1884), a species of dasycladalean alga known previously only from the mid-Silurian of Ontario
Reinterpretation of Voronocladus from the Silurian of Ukraine as a bryopsidalean alga (Chlorophyta): The outlines of a major early Paleozoic macroalgal radiation begin to come into focus
No full textVoronocladus dryganti Skompski et al. was recently erected as a new genus and species of dasycladalean alga on the basis of material from the Ludlovian Konivka Formation of western Ukraine. The thalli of this noncalcified macroalga are remarkable not only for their exceptional preservation, but also for showing unusual structures at the top, which were interpreted as epibionts. Here, an alternative interpretation is proposed for this material. In it, the affinity of Voronocladus as a siphonous green macroalga is retained, but as a bryopsidalean rather than dasycladalean alga, and the graptolite-like structures at the top are considered to represent the uppermost siphons of mature thalli instead of epibionts. Detailed morphological comparisons with living bryopsidalean taxa, as well as taphonomic and evolutionary considerations and key basal divergence dates indicated by molecular clock studies, provide support for the new interpretation. Viewed in broader terms, the reinterpreted morphology of Voronocladus is important because it (1) provides novel insights regarding the phylogenetic affinity of Ordovician and Silurian macroalgae with a form broadly similar to Voronocladus, and (2) helps to resolve the outlines of a major radiation of bryopsidalean algae that began during the Ordovician and continued into the Silurian. This event, which is only now beginning to come into focus, includes the initial evolution of Caulerpa- and Codium-like thalli and coincides with a major radiation of dasycladalean algae
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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