1,720,961 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
Modelling study of the protective role of OH radical scavengers and DNA higher order structures in induction of single- and double-strand break by gamma-radiation
No full textPurpose: To quantify the protective effects of (non-histonic) OH-radical scavengers and DNA higher-order structures in induction of single- and double-strand breaks by gamma rays.
Methods: Spatial distributions of energy depositions by gamma rays in liquid water were modelled with the track structure modules of the biophysical simulation code PARTRAC. Such distributions were superimposed on different DNA structure models (e.g. linear DNA, SV40 'minichromosomes' and compact chromatin), and direct energy depositions in the sugar-phosphate were considered as potential (direct) ssbs. The diffusion and interaction of the main chemical species produced in liquid water radiolysis were explicitly simulated, and reactions of OH radicals with the sugar-phosphate were considered as potential (indirect) ssbs. Two ssb on opposite DNA strands within 10 base pairs were considered as one dsb. Yields of ssb and dsb/Gy/Dalton in different DNA target structures were calculated as a function of the •OH mean life time, whose inverse value was taken as representative of the scavenging capacity (SC) of the DNA environment.
Results and Conclusions: This work provided a further validation of the models implemented in the PARTRAC code, thus allowing a better understanding of the mechanisms underlying DNA damage. More specifically, the protection due to •OH scavengers was separately quantified with respect to that due to histones and chromatin folding, which could be 'switched off' in the simulations. As expected, for a given value of the environment SC, linear DNA was found to be more susceptible to strand breakage than SV40 minichromosomes, which in turn showed higher damage yields with respect to cellular DNA, due to the larger accessibility offered to OH radicals. Furthermore, by increasing the SC the break yields decreased in all structures and tended to coincide with direct damage yields. Very good agreement was found with available experimental data. Comparisons with data on 'nucleoid' DNA (i.e. unfolded and histone-depleted DNA) also suggested that the experimental procedures used to obtain such structures may lower the environment SC, due to the loss of cellular scavengers
Role of DNA organisation and environmental conditions in the evolutions of radiobiological damage: models and simulations
No full textBackground and purpose: Theoretical models and Monte Carlo simulations were developed, aimed to investigate the role played by the
organisation of interphase DNA and the environmental scavenging capacity conditions in the induction of radiobiological damage.
Methods: The induction of single- and double-strand breaks by gamma rays impinging on different DNA structures (e.g. linear DNA, SV4O
minichromosome and cellular DNA) was simulated as a function of the environment scavenging capacity. Furthermore, yields of
chromosome aberrations (CA) induced by gamma rays and light ions were simulated with a purposely developed MC code that expiicitly
takes into account the DNA higher-order organisation as chromosome territories.
Results and Conclusions: Simulations performed with the PARTRAC code allowed quantification of the dependence of dsb and ssb both on
the target structure, and on the scavenging capacity. The results relative to CA showed the importance of DNA damage complexity
(nanometre scale) and interphase chromosome domains (micrometre scale) in the process of aberration formation. Very good agreement
was found between the model predictions on ssb, dsb and CA and available experimental data
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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