1,721,175 research outputs found
A large panel of novel microsatellite markers for the bank vole (Myodes glareolus)
No full textWe describe a set of 66 highly polymorphic microsatellite loci isolated
from the bank vole, Myodes (Clethrionomys) glareolus. These
microsatellites were characterized for a long-term study on periodically
fluctuating density of the bank vole population in Central Finland. We
detected six to 38 alleles per locus in the population sampled at two
different density phases, and the levels of observed and expected
heterozygosities varied between 0.17 and 1.00, and between 0.72 and
0.95, respectively. This microsatellite panel serves as an informative
tool for population and molecular genetic studies
Quantitative measure of sexual selection with respect to the operational sex ratio: a comparison of selection indices
No full textDespite numerous indices proposed to predict the evolution of mating
systems, a unified measure of sexual selection has remained elusive.
Three previous studies have compared indices of sexual selection under
laboratory conditions. Here, we use a genetic study to compare the most
widely used measures of sexual selection in natural populations. We
explored the mating and reproductive successes of male and female bank
voles, Clethrionomys glareolus, across manipulated operational sex
ratios ( OSRs) by genotyping all adult and pup bank voles on 13 islands
using six microsatellite loci. We used Bateman's principles (I(s) and I
and Bateman gradients) and selection coefficients (s' and beta') to
evaluate, for the first time, the genetic mating system of bank voles
and compared these measures with alternative indices of sexual selection
( index of monopolization and Morisita's index) across the OSRs. We
found that all the sexual selection indices show significant positive
intercorrelations for both males and females, suggesting that Bateman's
principles are an accurate and a valid measure of the mating system. The
Bateman gradient, in particular, provides information over and above
that of other sexual selection indices. Male bank voles show a greater
potential for sexual selection than females, and Bateman gradients
indicate a polygynandrous mating system. Selection coefficients reveal
strong selection gradients on male bank vole plasma testosterone level
rather than body size
Testosterone-Mediated Effects on Fitness-Related Phenotypic Traits and Fitness
No full textThe physiological and behavioral mechanisms underlying life-history
trade-offs are a continued source of debate. Testosterone (T) is one
physiological factor proposed to mediate the trade-off between
reproduction and survival. We use phenotypic engineering and multiple
laboratory and field fitness-related phenotypic traits to test the
effects of elevated T between two bank vole Myodes glareolus groups:
dominant and subordinate males. Males with naturally high T levels
showed higher social status (laboratory dominance) and mobility
(distance between capture sites) than low-T males, and the effect of T
on immune response was also T group specific, suggesting that behavioral
strategies may exist in male bank voles due to the correlated responses
of T. Exogenous T enhanced social status, mate searching (polygon of
capture sites), mobility, and reproductive success (relative measure of
pups sired). However, exogenous T also resulted in the reduction of
immune function, but only in males from the high-T group. This result
may be explained either by the immunosuppression costs of T or by
differential sensitivity of different behavioral strategies to steroids.
Circulating T levels were found to be heritable; therefore, female bank
voles would derive indirect genetic benefits via good genes from mating
with males signaling dominance
FITNESS TRADE-OFFS MEDIATED BY IMMUNOSUPPRESSION COSTS IN A SMALL MAMMAL
No full textTrade-offs are widespread between life-history traits, such as
reproduction and survival. However, their underlying physiological and
behavioral mechanisms are less clear. One proposed physiological factor
involves the trade-off between investment in male reproductive effort
and immunity. Based on this hypothesis, we investigated differences in
fitness between artificially selected immune response bank vole groups,
Myodes glareolus. Significant heritability of immune response was found
and a correlated response in testosterone levels to selection on immune
function. Male reproductive effort, reproductive success, and survival
of first generation offspring were assessed and we demonstrate a
relationship between laboratory measured immune parameters and fitness
parameters in field enclosures. We identify a trade-off between
reproductive effort and survival with immune response and parasites as
mediators. However, this trade-off results in equal male fitness in
natural conditions, potentially demonstrating different male signaling
strategies for either reproductive effort or survival. Females gain
indirect genetic benefits for either genetic disease resistance or male
reproductive effort, but not both. Immune response is genetically
variable, genetically linked to testosterone and may indirectly maintain
genetic variation for sexually selected traits. Evidence for both a
genetic and a field trade-off between reproductive effort and survival
indicates an evolutionary constraint on fitness traits
Preserving the ground beneath the paws: does the biodiversity hypothesis matter for wildlife health?
No full textMounting evidence supports the biodiversity hypothesis stating that contact to immunoprotective factors in the environment is required for development of a balanced immune system, explaining the prevalence of allergies and other inflammatory disorders in humans inhabiting post-industrial societies. Yet, while urban areas are the most rapidly expanding ecosystems on Earth, little is known how the biodiversity hypothesis applies to wildlife. We performed a soil exposure experiment using the ecological model bank vole (Myodes glareolus), where laboratory-born vole pups were exposed to different forest soil mixtures and sterile bedding in individually ventilated cages for four weeks and monitored metataxonomic changes in gut microbiota. Treatment soil was collected from urban forests and national parks, considering that soil microbiota can greatly differ between levels of human development index. We found that soil treatment decreases species evenness and increases dispersal in beta diversity estimates in faecal samples compared to sterile control. This dataset will be further analyzed for inflammation markers such as Foxp3 and Il-17 using qPCR. These data can inform conservation of soil microbiomes and enhance rewilding interventions, and also inform planning of urban greenspaces and improve domestic and zoo animal wellbeing
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
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