1,721,161 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
Adsorption of sulfonamide antibiotics onto high silica zeolites: from multidisciplinary model studies to applications to real waters
No full textOwing to their environmental diffusion and persistence, sulfonamide antibiotics (sulfa drugs) are
responsible to induce high level of resistance in bacteria. The sulfonamide anionic nature makes them
highly mobile along soil profile and is responsible for their accumulation into water bodies. In order
to limit the diffusion of resistance determinants, it is of utmost importance to identify adsorbents for
this antibiotic family to be adopted for water cleanup purpose. Three high silica zeolites (Y, MOR,
ZSM-5) have been tested for their capability to extract sulfonamides from water. Kinetics, capacity
and reversibility of the adsorption have been studied along with sulfonamide arrangement into the
porosities of each zeolite [1-3].
The sulfa drugs irreversibly adsorbed onto zeolite Y at ca. 26% on average and with the process
equilibrium reached in less than 1 min [1,3]. The favorable adsorption kinetics was confirmed when
zeolite Y was applied to both fresh and sea waters although the dissolved organic matter occurring
in natural water compartments can be retained as well but with a kinetics less favorable than that
shown by sulfa drugs. The main host-guest & guest-guest interactions between zeolites and sulfa drugs
were defined by IR and SS-NMR analysis, and augmented by computational studies. H-bonds and van
der Waals type interactions between single molecules and zeolite Y or ZSM-5 were responsible for
the irreversible extraction of sulfa drugs from water [1,3]. The occurrence of intramolecular medium
strength H-bond in small sized sulfa drugs upon adsorption inside zeolite Y cage revealed the formation
of dimeric species whose amidic or imidic tautomeric form were identified [1,3]. Rietveld refinement
and IR analysis revealed that sulfa drugs incorporation into MOR caused a close vicinity of the
heterocycle ring to the side pocket oxygens [2,3]. At 65°C, MOR gave rise to a sulfachloropyridazine
reaction product with a 100% selectivity and SNAr mechanism [2]. Among the regeneration strategies
approached, the thermal treatment and solvent extraction gave the best results.
References
[1] I. Braschi, G. Paul, G. Gatti, M. Cossi, L. Marchese. RSC Advances, 3, 7427 (2013).
[2] A. Martucci, M.A. Cremonini, S. Blasioli, L. Gigli, G. Gatti, L. Marchese, I. Braschi. Micropor.
Mesopor. Mat. 170, 274 (2013).
[3] S. Blasioli, A. Martucci, G. Paul, L. Gigli, M. Cossi, C.T Johnston, L. Marchese. J. Coll. Interface.
Sci., 419, 148 (2014)
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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