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
Multiple oxyanion reducing capacity of the copper-containing nitrite reductase of R. sullae
No full textRhizobium sullae is an unusual and unique bacterium due to the radical truncation of its denitrification electron transport chain. This bacterium has only one of the four terminal reductases required for complete denitrification. The sole reductase present, nitrite reductase, produces a toxic end product, nitric oxide. This enzyme cannot be used to support growth under anoxic conditions. Expression of the gene encoding nitrite reductase, nirK, is also unusual in that it does not require the presence of a nitrogen oxide. Expression only requires a decrease in oxygen concentration. The role of nitrite reductase in R. sullae has yet to be elucidated. The presence and expression of nitrite reductase has been investigated as a detoxification strategy or as a means to reduce the energy content in the bacterial cell in order to induce dormancy.
Since nitrite reductase expression only occurs under microoxic conditions it is possible the enzyme plays some role within the root nodule, which is a low oxygen environment. However, comparisons of nodulation efficiency, plant growth and nitrogen fixation have not revealed any significant differences between wild type and nitrite reductase-deficient strains, so far. Some evidence has been provided suggesting a link between nitrite reductase activity and the viability and culturability of the cells. Nitrite reductase activity may reduce energy content but it remains uncertain whether this is an indirect consequence of generation of nitric oxide or a desired result intended to prolong cell viability under certain conditions.
Recently, several bacterial species have been found to contain reductases with the capacity to reduce multiple oxyanions. The oxyanion reducing capacity activity of the copper-containing nitrite reductase of R. sullae was tested to determine its substrate range. In addition, the oxyanion-reducing capacity of several nirK-plus and nirK-minus strains of R. sullae was compared with that of other denitrifying and non-denitrifying bacterial strains belonging to the genera Stenotrophomonas, Bacillus, Agrobacterium and Rhodobacter. The results suggest that the nitrite reductase of R. sullae can reduce other physiologically important oxyanions, which may provide new insight into the role of this enzyme
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
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
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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