1,720,975 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
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
Organic carbon pools and storage in the soil of olive groves of different age
No full textCompared with annual crop cultivation, tree groves might represent a relevant land-use system to improve C sequestration, but few data are available to support this hypothesis. To evaluate the potential of olive tree (Olea europaea L., 1753) cultivation to store soil organic C (SOC), we assessed (i) the distribution of organic C in active (water-extractable and particulate organic C, WEOC and POC, respectively), intermediate (organic matter associated with stable sand-size aggregates and silt- and clay-size aggregates, SSAs and SCAs, respectively) and passive (organic matter resistant to oxidation, rSOM) pools, (ii) the phenol content of the C pools, (iii) the humic-C distribution of the intermediate C pool and (iv) the stocks of SOC pools in two olive groves of different age (7 years (OG7) and 30 years (OG30)) compared with a nearby site with cereal crops (arable soil, AS). In OG30 the organic C stock of the olive grove was no different from that of the AS, but the distribution of SOC pools changed with the age of the olive groves. The WEOC and POC increased in the Ap horizon of OGs, probably because of the herbaceous cover and distribution of chipped prunings on the soil. There were fewer SSAs in OG7 than AS, possibly because of pedoturbations from deep tillage before the olive trees were established, but they increased in OG30. The increase in SSAs and SCAs in the Bw and BC horizons of OG30 was associated with humic-C and unextractable-C and a smaller phenol content than AS. This suggested that the olive tree roots had a positive role through rhizodeposition and root turnover, which favoured the stabilization of organic matter into aggregates at depth. In contrast to the active and intermediate C pools, the passive C pool did not vary following the change in land use from arable to olive grove. Highlights: Effects of land-use change from arable to olive grove on soil organic C pools and stocks. Soil organic C stock increased from 7- to 30-year-old olive orchard. Olive tree cultivation affected active and intermediate C pools, but not the passive C pool. After 30 years, the olive grove stored an amount of SOC similar to that of the arable system
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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