1,720,960 research outputs found
Group fission-fusion dynamics and communication in the bottlenose dolphin (Tursiops truncatus)
Full text linkThe bottlenose dolphin exhibits a fission-fusion social structure characterized by temporary associations lasting from minutes to hours. Although social structure has been described for some dolphin communities, the selective pressures affecting fission-fusion patterns and their consequences on dolphin communication are not well understood. The goals of the present study were three-fold: 1) to quantify the rate with which fission-fusion occurred and identify the selective pressures influencing an individual\u27s decision to leave and join a temporary group; 2) to examine the communication signals produced during temporary separations; and 3) to estimate the distances over which dolphins could remain in acoustic contact while separated.
It was found that a dolphin\u27s decision to join or leave a group was related to social considerations such as the class of individual encountered (e.g., mothers with calves, adult single females, adult males, and juveniles) as dolphins move in different environments. The decision was also influenced by ecological characteristics such as the habitat where a dolphin was found. The two aspects in turn determined the rate of fission-fusion. Mothers with calves regularly using deep waters had high rates of fission-fusion. Those females encountered other females in the same reproductive condition frequently and associated with them. In contrast, mothers with calves using shallow waters had lower fission-fusion rates. Those females encountered juvenile dolphins often but they did not associate with them frequently.
Temporarily separated dolphins did not always produce the sounds typically used for long-distance communication, and sometimes they did not use any detectable acoustic signal to find each other. On average, this absence of communication occurred at distances less than 50 m. When both whistles and echolocation produced, they were apparently involved in maintaining contact between mothers and their calves and other associates. Estimates of active spaces defined by whistle transmission indicated that communication range varied between habitats. Shallow seagrass areas had the smallest active space while channels had the greatest active space. Findings indicated that the distances over which dolphins remain in acoustic contact and can be considered members of groups are much greater than has been described from observations of dolphin spacing and activity alone
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
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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