1,720,961 research outputs found
Seleção sexual em multi-escalas: efeitos da malária aviária sobre o comportamento de leque e preferência da fêmea do uirapuru-de-coroa-azul (Lepidothrix coronata, Aves: Pipridae)
Full text linkInfection by blood parasites of the genus Plasmodium can affect survival and reproduction in the host, and may affect the expression of sexual selection traits. Although different studies highlight the association of parasitism with a decrease in reproductive success of hosts, it is still uncertain which fitness components are affected by the parasites. Hence, few studies have addressed the role of parasites in honest signalling among lekking species. Here, we investigated if infection by Plasmodium spp. compromises rates of vocalization, dance and social interaction of male Blue-crowned Manakins (Lepidothrix coronata), and if it affects female preferences in a Central Amazon population. Behavioral observations coupled with molecular diagnosis to detect haemosporidian parasites revealed that infection by Plasmodium affected male activities, as well as female choice. Furthemore, despite similar visiting frequencies to both infected and uninfected males, they were more frequent to males that vocalized and danced more, which were more frequently not infected. Therefore, we suggest a role of male vocalization and dance rates as honest signals for females, indicating male immunity in the studied population. Thus, male exhibitions would function as an important signal for sexual selection, used by females as cues about the probability of a male being infected. Future studies testing the inheritance of female preferences and male behaviour rates will add to the understanding of the role of such behaviors in the evolution of mechanisms of female preferences with honest signals.A infecção de aves por hemoparasitos do gênero Plasmodium pode afetar a sobrevivência e reprodução, já que os hospedeiros podem apresentar alterações dos caracteres usados na seleção sexual. Embora diferentes estudos ressaltem a associação do parasitismo com a diminuição do sucesso reprodutivo dos hospedeiros, ainda é incerto quais seriam os componentes deste afetados pelo parasitismo. Por isso, investigamos se a infecção por Plasmodium spp. compromete as taxas de vocalização, dança e interação social em machos de Lepidothrix coronata (uirapuru-de-chapéu-azul), e se a mesma altera a preferência sexual das fêmeas, em leks e indivíduos de uma população da Amazônia Central. Observações do comportamento e diagnóstico molecular para detecção de hemoparasitos revelaram que a infecção por Plasmodium afetou a atividade dos machos, bem como a escolha das fêmeas. E, mesmo visitando tanto machos infectados quanto não infectados, as fêmeas discriminam os mesmos pela sua atividade, visitando machos que vocalizam e dançam mais, os quais, são menos infectados. Assim, sugere-se o papel da atividade de vocalização e dança dos machos como um sinal honesto de resistenciados mesmos na população estudada. Por isso, as exibições dos machos seriam um importante sinalizador para a seleção sexual, uma vez que tais características permitem às fêmeas obterem pistas sobre a probabilidade de um macho estar, ou não, infectado por Plasmodium spp.. Trabalhos futuros que testem a herança das preferências e das atividade dos machos auxiliarão no entendimento do papel evolutivo dos comportamentos aqui apresentados para mecanismos de preferências de fêmeas com sinalização honesta
A new southern limit for the distribution of the thrush-like Wren, Campylorhynchus turdinus (Aves: Troglodytidae)
Full text linkWe report the first record of the Thrush-like Wren Campylorhynchus turdinus (Wied, 1831) in the Rio Grande do Sul state, at the city of Santa Maria, Brazil. The record, in which the individual vocalized and changed its perch constantly, was held on April 2015. We extend the known distribution range of the C. turdinus, and establish a new southern limit for its geographic distribution, approximately 460 km from the previous record in Paraná. For the state of Rio Grande do Sul, Helmut Sick reported the presence of the C. turdinus in 1972. However, the occurrence was considered hypothetical because did not agree with its distribution pattern. Therefore, our record of C. turdinus for the state of Rio Grande do Sul update the list for this state. © 2016, Sociedade Brasileira de Ornitologia. All rights reserved
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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