1,721,009 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
Social Prophylaxis: Group Interaction Promotes Collective Immunity in Ant Colonies
No full textSummaryLife in a social group increases the risk of disease transmission [1–3]. To counteract this threat, social insects have evolved manifold antiparasite defenses, ranging from social exclusion of infected group members to intensive care [2, 4]. It is generally assumed that individuals performing hygienic behaviors risk infecting themselves, suggesting a high direct cost of helping [4–6]. Our work instead indicates the opposite for garden ants. Social contact with individual workers, which were experimentally exposed to a fungal parasite, provided a clear survival benefit to nontreated, naive group members upon later challenge with the same parasite. This first demonstration of contact immunity in Social Hymenoptera and complementary results from other animal groups and plants [7–9] suggest its general importance in both antiparasite and antiherbivore defense. In addition to this physiological prophylaxis of adult ants, infection of the brood was prevented in our experiment by behavioral changes of treated and naive workers. Parasite-treated ants stayed away from the brood chamber, whereas their naive nestmates increased brood-care activities. Our findings reveal a direct benefit for individuals to perform hygienic behaviors toward others, and this might explain the widely observed maintenance of social cohesion under parasite attack in insect societies
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
Ecological genetics and evolution of the Large Blue butterfly – consequences of an extraordinary lifecycle
No full textThe large blue butterflies (genus Maculinea) have received much attention from both scientists and the general public. The reason for this is their highly specialized life cycle that depends on the dual presence of a species specific larval food-plant and host-ant. The genus consists of at least six species, which are all confined to grasslands. This habitat type has declined rapidly in the last century, and all Maculinea species are locally threatened in large parts of their distribution ranges. Appropriate future conservation of these species requires detailed knowledge on their complex life cycles.Moreover, this knowledge allows studies of the origin and evolution of specific life history traits, and for this purpose a well resolved phylogeny is essential. The phylogentic relationship between Maculinea and its sister genus Phengaris has been disputed due to conflicting results from molecular and morphological datasets. By including additional taxa and genetic markers to the existing molecular dataset, I improved the molecular phylogeny of the Glaucopsyche section where the two genera are placed, and find high support for Maculinea being a monophyletic clade.The relationships within Maculinea species have also been unclear. Many subspecies have been described, due to variation in the wing pattern of imagos, but also due to differences in larval food-plant or host-ant. In particular, three species (M. teleius, M. nausithous and M. arion) harbour high genetic variation, suggesting the presence of cryptic species or isolated populations with limited gene flow. I investigated the geographical distribution of evolutionary lineages within M. arion. The distribution range of M. arion covers most of the Palaearctic region, in which three distinct genetic lineages were recovered.While the distribution of individuals at the continental scale is likely to reflect historical processes, the distribution at the regional and landscape scale also reflects contemporary processes. In a world where natural habitats are rapidly disappearing, a species ability to disperse plays a critical role in population viability – both in terms of colonizing new suitable habitats and by enabling gene flow among neighbouring populations. I estimated the effective dispersal of M. arion, which is considered a sedentary species. Interestingly, gene flow occurs over distances 15 times further than the maximum recorded dispersal distance, however this depends on the presence of interconnected sites. Habitat loss often leads to reductions in population sizes and increasing isolation of populations. Remaining populations will consequently be more vulnerable to stochastic demographic and environmental effects. Furthermore, the lack of gene flow will increase the impact of genetic drift and bottlenecks and can lead to genetically impoverished and inbred populations. We studied an isolated population of M. arion that recently went through a drastic reduction in population size. While the population is genetically less diverse than extant populations that are part of functioning population networks, our time series analysis of natural history collection specimens show that this pattern is due to historical rather than recent influences
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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