Parasitized mates increase infection risk for partners

Peer reviewedPublisher PD

“Living on the edge” : the role of field margins for common vole (Microtus arvalis) populations in recently colonised Mediterranean farmland

Acknowledgments RRP was supported by a PhD-studentship from the University of Valladolid (co-funded by Banco Santander, RR 30/04/2014). Financial support was provided by ECOCYCLES (BIODIVERSA 2008, Era-net European project, EUI2008-03658 and NERC NE/G002045/1 to XL) and ECOVOLE projects (CGL2012-35348; Ministerio de Economía y Competitividad of Spain). The article also contributes to project ECOTULA (CGL2015-66962-C2-1-R). We held all the necessary licenses and permits for conducting this work (JJLL, FM and RRP held animal experimentation permits of level B for Spain, and a capture permit was provided by the Consejería de Fomento y Medio Ambiente, Junta de Castilla y León (Expte: EP/CYL/665/2014)). We thank two anonymous reviewers for providing and constructive comments to improve the manuscript.Peer reviewedPublisher PD

Discrepancy-Based Active Learning for Domain Adaptation

The goal of the paper is to design active learning strategies which lead to domain adaptation under an assumption of covariate shift in the case of Lipschitz labeling function. Building on previous work by Mansour et al. (2009) we adapt the concept of discrepancy distance between source and target distributions to restrict the maximization over the hypothesis class to a localized class of functions which are performing accurate labeling on the source domain. We derive generalization error bounds for such active learning strategies in terms of Rademacher average and localized discrepancy for general loss functions which satisfy a regularity condition. A practical K-medoids algorithm that can address the case of large data set is inferred from the theoretical bounds. Our numerical experiments show that the proposed algorithm is competitive against other state-of-the-art active learning techniques in the context of domain adaptation, in particular on large data sets of around one hundred thousand images.Comment: 28 pages, 11 figure

Deep Anti-Regularized Ensembles provide reliable out-of-distribution uncertainty quantification

We consider the problem of uncertainty quantification in high dimensional regression and classification for which deep ensemble have proven to be promising methods. Recent observations have shown that deep ensemble often return overconfident estimates outside the training domain, which is a major limitation because shifted distributions are often encountered in real-life scenarios. The principal challenge for this problem is to solve the trade-off between increasing the diversity of the ensemble outputs and making accurate in-distribution predictions. In this work, we show that an ensemble of networks with large weights fitting the training data are likely to meet these two objectives. We derive a simple and practical approach to produce such ensembles, based on an original anti-regularization term penalizing small weights and a control process of the weight increase which maintains the in-distribution loss under an acceptable threshold. The developed approach does not require any out-of-distribution training data neither any trade-off hyper-parameter calibration. We derive a theoretical framework for this approach and show that the proposed optimization can be seen as a "water-filling" problem. Several experiments in both regression and classification settings highlight that Deep Anti-Regularized Ensembles (DARE) significantly improve uncertainty quantification outside the training domain in comparison to recent deep ensembles and out-of-distribution detection methods. All the conducted experiments are reproducible and the source code is available at \url{https://github.com/antoinedemathelin/DARE}.Comment: 26 pages, 9 figure

A transcriptomic investigation of handicap models in sexual selection

We are grateful to D. Calder and T. Helps for access to study sites, and G. Murray-Dickson and M. Oliver for help with fieldwork and comments on manuscript drafts. This work was funded by NERC grant NE/D000602/1 (SBP), a NERC advanced fellowship (FM) and a BBSRC studentship (MAW)Peer reviewedPostprin

Unintentional effects of environmentally-friendly farming practices : arising conflicts between zero-tillage and a crop pest, the common vole (Microtus arvalis)

We are grateful to Dra. Aurora Sombrero Sacristán (ITACyL) and her staff for allowing this experiment to take place parallel to their own and for providing information on the experimental field for this research. We would also like to thank Dr Alex Douglas for his help with the statistical analysis, and K. Barré and an anonymous reviewer for help comments on the MS. This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/M010996/1], through Eastbio DTP. The surveys were carried out under ITACYL project 2007/2155. Sir Maitland Mackie Scholarship provided additional funding to the lead author, D. Roos, for which he is grateful. The authors report no conflict of interests.Peer reviewedPublisher PD

Viral Zoonoses in Small Wild Mammals and Detection of Hantavirus, Spain

We screened 526 wild small mammals for zoonotic viruses in northwest Spain and found hantavirus in common voles (Microtus arvalis) (1.5%) and high prevalence (48%) of orthopoxvirus among western Mediterranean mice (Mus spretus). We also detected arenavirus among small mammals. These findings suggest novel risks for viral transmission in the region.Non peer reviewe

Honest sexual signalling mediated by parasite and testosterone effects on oxidative balance

Extravagant ornaments evolved to advertise their bearers' quality, the honesty of the signal being ensured by the cost paid to produce or maintain it. The oxidation handicap hypothesis (OHH) proposes that a main cost of testosterone-dependent ornamentation is oxidative stress, a condition whereby the production of reactive oxygen and nitrogen species (ROS/RNS) overwhelms the capacity of antioxidant defences. ROS/RNS are unstable, very reactive by-products of normal metabolic processes that can cause extensive damage to key biomolecules (cellular proteins, lipids and DNA). Oxidative stress has been implicated in the aetiology of many diseases and could link ornamentation and genetic variation in fitness-related traits. We tested the OHH in a free-living bird, the red grouse. We show that elevated testosterone enhanced ornamentation and increased circulating antioxidant levels, but caused oxidative damage. Males with smaller ornaments suffered more oxidative damage than those with larger ornaments when forced to increase testosterone levels, consistent with a handicap mechanism. Parasites depleted antioxidant defences, caused oxidative damage and reduced ornament expression. Oxidative damage extent and the ability of males to increase antioxidant defences also explained the impacts of testosterone and parasites on ornamentation within treatment groups. Because oxidative stress is intimately linked to immune function, parasite resistance and fitness, it provides a reliable currency in the trade-off between individual health and ornamentation. The costs induced by oxidative stress can apply to a wide range of signals, which are testosterone-dependent or coloured by pigments with antioxidant properties

Effects of human activity on physiological and behavioral responses of an endangered steppe bird

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Behavioral Ecology following peer review. The version of recordBehavioral Ecology 26.3 (2015): 828-838 is available online at: http://beheco.oxfordjournals.org/content/early/2015/04/02/beheco.arv016Animals may perceive humans as a form of predatory threat, a disturbance, triggering behavioral changes together with the activation of physiological stress responses. These adaptive responses may allow individuals to cope with stressful stimuli, but a repeated or long-term exposure to disturbances may have detrimental individual- and population-level effects. We studied the effects of human activities, particularly hunting, on the behavior and physiological status of a near-threatened nongame steppe bird, the little bustard. Using a semiexperimental approach, we compared before, during, and after weekends: 1) the type and intensity of human activities and 2) the behavior and 3) physiological stress (fecal corticosterone metabolites) of wintering birds. Higher rates of human activity, in particular those related to hunting, occurred during weekends and caused indirect disturbance effects on birds. Little bustards spent more time vigilant and flying during weekends, and more time foraging in the mornings after weekend, possibly to compensate for increased energy expenditure during weekends. We also found increased physiological stress levels during weekends, as shown by higher fecal glucocorticoid metabolite concentrations. Increased corticosterone metabolite levels were associated with the highest levels of hunting-related disturbances. Little bustard showed marked behavioral and physiological (stress hormones) responses to human activities that peaked during weekends, in particular hunting. The long-term effect of this particular activity carried out during weekends from autumn throughout winter might adversely impact wintering populations of this nongame endangered species, potentially counteracting conservation efforts conducted on local as well as foreign breeding populationsFunding was provided by the Comunidad de Madrid and Universidad Autónoma de Madrid (CCG10-UAM/AMB-5325), Spanish Ministry of Science (CGL2009-13029/BOS), and REMEDINAL2 network of the CAM (S-2009/AMB/1783) and PhD grant from the Spanish Minister of Education (FPU to R.T.) and JAE-Doc contract funded from CSIC and the European Social Fund (ESF to F.C