Université de Sherbrooke

About: Université de Sherbrooke is a education organization based out in Sherbrooke, Quebec, Canada. It is known for research contribution in the topics: Population & Receptor. The organization has 14922 authors who have published 28783 publications receiving 792511 citations. The organization is also known as: Universite de Sherbrooke & Sherbrooke University.

G-protein-coupled receptors signalling at the cell nucleus: an emerging paradigm.

Abstract: G-protein-coupled receptors (GPCRs) comprise a wide family of monomeric heptahelical glycoproteins that recognize a broad array of extracellular mediators including cationic amines, lipids, peptide...

Roball, the Rolling Robot

Abstract: Designing a mobile robotic toy is challenging work The robot must be appealing to children and create interesting interactions while facing the wide variety of situations that can be experienced while playing with a child, and all at a reasonable cost In this paper we present Roball, a ball-shaped robot that moves by making its external spherical shell rotate Such design for a mobile robotic toy shows robustness in handling unstructured environments and unconstrained interactions with children Results show that purposeful movements of the robot, its physical structure and locomotion dynamics generate interesting new games influenced by the environment and the child

What does carotenoid-dependent coloration tell? : Plasma carotenoid level signals immunocompetence and oxidative stress state in birds - A meta-analysis

Abstract: Mechanisms maintaining honesty of sexual signals are far from resolved, limiting our understanding of sexual selection and potential important parts of physiology. Carotenoid pigmented visual signals are among the most extensively studied sexual displays, but evidence regarding hypotheses on how carotenoids ensure signal honesty is mixed. Using a phylogenetically controlled meta-analysis of 357 effect sizes across 88 different species of birds, we tested two prominent hypotheses in the field: that carotenoid-dependent coloration signals i) immunocompetence and/or ii) oxidative stress state. Separate meta-analyses were performed for the relationships of trait coloration and circulating carotenoid level with different measures of immunocompetence and oxidative stress state. For immunocompetence we find that carotenoid levels (r = 0.20) and trait color intensity (r = 0.17) are significantly positively related to PHA response. Additionally we find that carotenoids are significantly positively related to antioxidant capacity (r = 0.10), but not significantly related to oxidative damage (r = -0.02). Thus our analyses provide support for both hypotheses, in that at least for some aspects of immunity and oxidative stress state the predicted correlations were found. Furthermore, we tested for differences in effect size between experimental and observational studies; a larger effect in observational studies would indicate that co-variation might not be causal. However, we detected no significant difference, suggesting that the relationships we found are causal. The overall effect sizes we report are modest and we discuss potential factors contributing to this, including differences between species. We suggest complementary mechanisms maintaining honesty rather than the involvement of carotenoids in immune function and oxidative stress and suggest experiments on how to test these.

Decomposing the variation in population growth into contributions from multiple demographic rates

Abstract: Summary 1 The decomposition of variation in population growth into the relative contributions from different demographic rates has multiple uses in population, conservation and evolutionary biology Recent research has favoured methods based on matrix models termed ‘life-table-response experiments’ or more generally ‘the retrospective matrix method’, which provide an approximation of a complete demographic decomposition The performance of the approximation has not been assessed 2 We compare the performance of the retrospective matrix method to a complete decomposition for two bighorn sheep populations and one red deer population 3 Different demographic rates make markedly different contributions to variation in growth rate between populations, because each population is subject to different types of environmental variation 4 The most influential demographic rates identified from decomposing observed variation in population growth are often not those showing the highest elasticity Consequently, those demographic rates most strongly associated with deterministic population growth are not necessarily strongly associated with temporal variation in population growth 5 The retrospective matrix method provides a good approximation of the demographic rate associated most strongly with variation in population growth However, failure to incorporate the contribution of covariation between demographic rates when decomposing variation in population growth can lead to spurious conclusions