1,721,079 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
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
Species interactions alter evolutionary responses to a novel environment.
Get PDF01/08/012 MEB. OA journal. published version , ok to upload.Studies of evolutionary responses to novel environments typically consider single species or perhaps pairs of interacting species. However, all organisms co-occur with many other species, resulting in evolutionary dynamics that might not match those predicted using single species approaches. Recent theories predict that species interactions in diverse systems can influence how component species evolve in response to environmental change. In turn, evolution might have consequences for ecosystem functioning. We used experimental communities of five bacterial species to show that species interactions have a major impact on adaptation to a novel environment in the laboratory. Species in communities diverged in their use of resources compared with the same species in monocultures and evolved to use waste products generated by other species. This generally led to a trade-off between adaptation to the abiotic and biotic components of the environment, such that species evolving in communities had lower growth rates when assayed in the absence of other species. Based on growth assays and on nuclear magnetic resonance (NMR) spectroscopy of resource use, all species evolved more in communities than they did in monocultures. The evolutionary changes had significant repercussions for the functioning of these experimental ecosystems: communities reassembled from isolates that had evolved in polyculture were more productive than those reassembled from isolates that had evolved in monoculture. Our results show that the way in which species adapt to new environments depends critically on the biotic environment of co-occurring species. Moreover, predicting how functioning of complex ecosystems will respond to an environmental change requires knowing how species interactions will evolve
Ecological and evolutionary aspects of interactions between microbes coinfecting plants
Get PDFCoinfections of one host with multiple pathogen species are common, and have important implications for host health and pathogen fitness. In the research reported here, plant virus systems were used to explore the effects of coinfection on pathogen populations and host responses. Chapter 1 addresses the importance of coinfection timing using Barley yellow dwarf virus (BYDV-PAV) and Barley stripe mosaic virus. Coinfection timing significantly influenced viral within-host competition. Additionally, simultaneous coinfections were significantly more severe than sequential coinfections, which were only as severe as the most damaging constituent virus. A mathematical model was used to demonstrate that inaccurate projections of disease impacts on host populations can result when the effects of coinfection timing are not taken onto account. Chapter 2 explores the effects of coinfections of Cereal yellow dwarf virus (CYDV-RPV) and two species of BYDV (PAV and PAS) on pathogen evolution using an experimental evolution approach. Viruses exhibited altered within-host concentrations and transmission after serial passage in coinfections, without altered disease severity. Chapter 3 examines interactions between Bean common mosaic virus (BCMV) and Clover yellow vein virus (ClYVV)), and a microbial mutualist, rhizobia bacteria. The presence of rhizobia allowed ClYVV to reach higher within-host concentrations in coinfections. Viral transmission was also affected by interactions between coinfection and plant nitrogen source. Viral infection significantly reduced the percentage of nitrogen in plant tissues derived from microbial mutualists, with a greater than additive decrease in coinfections. Chapter 4 assesses the effects of BCMV and ClYVV coinfection and rhizobia colonization on plant primary and secondary metabolism. Increased photosynthetic rates were observed in plants colonized by rhizobia, which were driven by increased maximum rates of electron transport. Infection status, inorganic nitrogen fertilizer, and rhizobia had significant effects on components of plant volatile organic compound (VOC) emissions, with nitrogen source significantly affecting overall VOC profile composition. Chapter 5 analyzes how reductions in rhizobial nitrogen fixation caused by viral infection affect soil fertility, and projects substantial monetary losses for farmers when viral prevalence is high in a legume rotation, either due to additional fertilizer costs or reduced yield of a subsequent non-legume crop
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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