1,720,955 research outputs found
Male mating tactics and secondary sexual traits: insights from the Mediterranean killifish, Aphanius fasciatus
Full text linkContext. Sexual selection results from male competition and female choice linked by complex interactions that drive the population’s life history, often leading to the development of specific secondary sexual traits with an increased reproductive success. Aims. To investigate the male mating tactics and the role of a secondary sexual trait (‘black band’ on the caudal fin) along the male ontogenetic development in the Mediterranean killifish, Aphanius fasciatus (Valenciennes, 1821). Methods. Male–male competition was investigated through a combination of an extensive field collection and behavioural analysis under controlled conditions, comparing four groups differing in the presence or absence of the black band and body size. Key results. Banded males courted more and tended to monopolise the female, but the overall spawning performance did not differ significantly among the analysed groups. Conclusion. (1) The black band on the caudal fin depends on ontogeny; (2) all mature males express the entire courtship and competitive repertory; (3) sexual maturity occurs in fish of at least 20 mm; (4) large size and presence of the black band seem to contribute to male dominance. Implications. This study has highlighted the role of Aphanius fasciatus as an excellent model for studying polygynandrous mating systems, on the basis of intense male–male competition
Interspecific aggression and food competition between the global invader Palaemon macrodactylus and the native Palaemon elegans
Full text linkThe impact of invasive alien species on native communities can act at different levels both
by affecting the ecosystem’s structure (i.e., mainly in the case of vegetation) and through direct
interactions (i.e., competition for food or space). Behavioral studies under controlled conditions can
provide relevant information on both the invasive potential of alien species and the potential impact
of the invaders on the local native species. In the laboratory, the competition for food resources
between the invasive oriental shrimp Palaemon macrodactylus, Rathbun, 1902, and the Mediterranean
native shrimp Palaemon elegans, Rathke, 1836, was analyzed. These species are typical residents of
coastal transitional and estuarine waters, so the experiments were carried out using two salinity
conditions that characterize the coastal lagoon of Venice. Although at both salinity treatments the
alien species tended to be more aggressive than the native one, significant differences between the
two species were mainly observed at a salinity of 30. In particular, at a salinity of 30, P. macrodactylus
spent more time attending to the food source than the native species. The results are discussed in
light of the potential inter-specific competition between the two species within the conditions of the
Venice lagoon
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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