1,721,078 research outputs found
Data from: Inbreeding, inbreeding depression and infidelity in a cooperatively-breeding bird
Full text linkInbreeding depression plays a major role in shaping mating systems: in particular, inbreeding avoidance is often proposed as a mechanism explaining extra-pair reproduction in socially-monogamous species. This suggestion relies on assumptions which are rarely comprehensively tested: that inbreeding depression is present, that higher kinship between social partners increases infidelity, and that infidelity reduces the frequency of inbreeding. Here, we test these assumptions using 26 years of data for a cooperatively-breeding, socially-monogamous bird with high female infidelity, the superb fairy-wren (Malurus cyaneus). Although inbred individuals were rare (~6% of offspring), we found evidence of inbreeding depression in nestling mass (but not in fledgling survival). Mother-son social pairings resulted in 100% infidelity, but kinship between a social pair did not otherwise predict female infidelity. Nevertheless, extra-pair offspring were less likely to be inbred than within-pair offspring. Finally, the social environment (the number of helpers in a group) did not affect offspring inbreeding coefficients or inbreeding depression levels. In conclusion, despite some agreement with the assumptions that are necessary for inbreeding avoidance to drive infidelity, the apparent scarcity of inbreeding events and the observed levels of inbreeding depression seem insufficient to explain the ubiquitous infidelity in this system, beyond the mother-son mating avoidance
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
Effect of diet macronutrient content, infection and injury stress on larval and adult life-history traits in Drosophila melanogaster
Full text linkDietary restriction (DR), the limitation of calories or a particular nutrient
intake without malnutrition, extends lifespan and delays ageing across a range of
taxa. To understand this response better and therefore its importance in the ageing
process, it is important to understand the evolutionary basis of this response and
its generality across environments. Several evolutionary hypotheses about why DR
increases lifespan have been proposed, and one in particular suggests DR
individuals are frailer and only live longer than non-DR individuals under benign
laboratory conditions. Dietary macronutrients have been found to alter infection
outcomes, potentially due to altered immune responses and changes in the rate of
clearing of pathogen (resistance), or other effects of diet on host-parasite
interactions including the ability to withstand a given pathogen load (disease
tolerance). Individuals in other host-pathogen systems have been found to alter
their diet choice as a result of infection. Adult DR responses and response to
infection may also be altered by juvenile environmental conditions, as juvenile diets
have been shown to have important effects for multiple adult life-history traits.
To understand the interactions between DR, injury and infection stress, and
juvenile and adult environments, here I ask the following questions using the
Drosophila melanogaster - Pseudomonas entomophila host-pathogen system, and
diets differing in the ratio of macronutrients (protein to carbohydrate ratios, P:C):
(i) Do additional stresses of injury and infection remove the lifespan benefit of DR,
and are some diets better for D. melanogaster survival post-infection with
Pseudomonas entomophila? (ii) Does larval dietary macronutrient manipulation
affect adult life-history traits and survival post-infection? (iii) Do infected
D. melanogaster individuals have altered diet preference post-infection with P.
entomophila? and (iv) Does diet affect host resistance or disease tolerance with
P. entomophila infection? By addressing these questions, I hope to improve our
understanding of the evolutionary basis of the DR response and its generality
across environments.
In chapter 2, I show that the benefits of DR response remain even with
injury and infection stress, where with decreasing P:C, survival increases and the
rate of ageing decreases, as does reproduction. Low P:C diets are particularly bad
for survival post-infection with P. entomophila, and injury stress has no additional
effect on survival in comparison to the control group. In chapter 3, I show that
intermediate to high larval P:C increases measures of larval development and
increases adult reproduction, however larval P:C does not alter adult lifespan or
infection outcomes. In chapter 4, I show that short-term diet preference does not
change with injury or P. entomophila infection. In chapter 5, I show that although
higher P:C increases post-infection survival with P. entomophila, this may not due
to increased resistance, as bacterial loads and a measure of the immune response
to P. entomophila, AMP gene expression, are similar across two P:C diets. These
data suggest a potential role of increased disease tolerance on the higher P:C diet
with P. entomophila, requiring further study. Taken together, these data suggest
that the response to DR, achieved through lowering P:C ratio, is relatively
unaffected by the additional stresses of infection and injury; that adult, not
juvenile, dietary macronutrient manipulation alters infection outcomes; and that
this may be independent of changes in bacterial clearance. This suggests that the
most likely evolutionary explanation for the DR response is that it is an adaptive
shift in relative investment in life-history traits that is consistent across
environments, particularly exposure to infection and injury. Furthermore, these
results provide further evidence of differential effects of P:C depending on the
host-pathogen pair, requiring further study to understand these complex
interactions across systems
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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