1,721,004 research outputs found
Parasite infection, but not immune response, influences paternity in western bluebirds
No full textParasites can impose heavy costs on their hosts, and females may benefit from selecting mates that are parasite resistant and/or have a stronger immune response. Trade-offs between immune response and sexual signaling have been proposed as a mechanism to ensure signal honesty. Much of the work on sexual signaling and immune response does not consider parasites directly and thus cannot confirm whether a stronger immune response necessarily results in lower parasite burdens. Also, immunity is costly, and these costs can lower the overall fitness of individuals with too strong of an immune response. Males with immune responses of intermediate strength are therefore expected to be preferred by females and have the highest reproductive success. We tested whether immune response and blood parasite loads relate to sexual signaling and mating preferences in western bluebirds (Sialia mexicana). Immunity did not predict male reproductive success when considering either within- or extra-pair offspring, although a stronger immune response was correlated with lower parasite loads. However, uninfected males were more likely to sire extra-pair offspring than males infected with avian malaria. Thus, females were more likely to mate with uninfected males but not necessarily males with a stronger immune response. Our results may indicate that females select parasite-resistant males as mates to gain resistance genes for their offspring or that infected males are less likely to pursue extra-pair copulations.PostprintThis article will become available to the public on February 1, 2016
(Dermaptera: Anisolabididae)
No full textCannibalism is a common occurrence in nature, and many cannibals prey on relatively small and defenseless life stages, such as eggs or young juveniles. Such behavior provides many benefits to the cannibal, but cannibalistic individuals also face risks, including the cost of decreasing their inclusive fitness by eating close relatives such as siblings or offspring. This risk can be mitigated if cannibals can recognize and avoid preying on kin. Here, we tested whether male ringlegged earwigs Euborellia annulipes avoid cannibalizing eggs that they had sired. In this species, females care for their own eggs, but males provide no care and frequently prey upon eggs. We found that when presented with an unguarded clutch of eggs, male earwigs nearly always cannibalized some eggs, but that the proportion of eggs eaten was smaller if the male had sired the clutch. This suggests that males can distinguish between their own offspring and unrelated offspring and that they avoid harming their kin.This project was funded by Allegheny College.Published articl
Coloration, Paternity, and Assortative Mating in Western Bluebirds
No full textColoration in birds can act as an important sexual signal in males, yet in many species, both sexes display bright colors. Social selection may account for this pattern, with more brightly colored individuals pairing together on the best territories. Mutual mate choice may also explain this, as males investing a great deal of parental care in the offspring should be choosy about their social mates. It is less clear whether this pattern of mate choice can apply to extra-pair partners as well. We examined western bluebirds (Sialia mexicana) to determine whether more colorful individuals tended to pair with one another, both in social pairs and between females and their extra-pair partners. Both male and female western bluebirds display both UV-blue structural plumage and a melanin-based chestnut breast patch, although females are duller than males. Social pairs mated assortatively with regard to UV-blue brightness, but not chestnut coloration. There was no evidence that extra-pair partners mated assortatively, but males with brighter UV-blue coloration had fewer extra-pair offspring in their nests. Older males were more successful at siring extra-pair offspring, despite displaying no differences in coloration compared to younger males. Coloration did not play a role in determining extra-pair male success. These results suggest that coloration plays a role in the formation of social pairs, but not mate choice for extra-pair partners.PreprintThis version of the article is available for viewing to the public after February 1, 2016
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
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