Microphallus papillorobustus (Trematoda) : A review of its effects in lagoon ecosystems

An increasing number of studies underlines the need to consider parasitism as an important component of ecosystem functioning. In this paper, we review the multi-effects of the trematode Microphallus papillorobustus in the salt marshes of Southern France. We describe the effects of this parasite on the behaviour, fecundity, growth and survival of its hosts, as well as its consequences on host sexual selection and finally, its role in maintaining biodiversity. In the light of this review, we suggest that this parasite should be considered as an important species to understand the functioning of lagunar ecosystemsUn nombre croissant de travaux en écologie souligne la nécessité de prendre en considération le parasitisme dans l'étude du fonctionnement des écosystèmes. Dans cet article, nous présentons une synthèse sur les multiples effets du trématode Microphallus papillorobustus dans les écosystèmes lagunaires du sud de la France. Nous passons ainsi en revue l'influence de ce parasite sur le comportement, la fécondité, la croissance et la survie des espèces hôtes, sur ses conséquences dans les processus de sélection sexuelle et enfin sur son rôle dans le maintien de la diversité. A la lumière de cette synthèse, il semble nécessaire de considérer ce parasite comme une espèce importante dans le fonctionnement des écosystèmes lagunaires

Gerber–Shiu distribution at Parisian ruin for Lévy insurance risk processes

Inspired by works of Landriault et al. [11, 12], we study the Gerber{Shiu distribution at Parisian ruin with exponential implementation delays for a spectrally negative Levy insurance risk process. To be more specific, we study the so-called Gerber{Shiu distribution for a ruin model where at each time the surplus process goes negative, an independent exponential clock is started. If the clock rings before the surplus becomes positive again then the insurance company is ruined. Our methodology uses excursion theory for spectrally negative Levy processes and relies on the theory of so-called scale functions. In particular, we extend recent results of Landriault et al. [11, 12]

Can Peto\u27s paradox be used as the null hypothesis to identify the role of evolution in natural resistance to cancer? A critical review

BACKGROUND: Carcinogenesis affects not only humans but almost all metazoan species. Understanding the rules driving the occurrence of cancers in the wild is currently expected to provide crucial insights into identifying how some species may have evolved efficient cancer resistance mechanisms. Recently the absence of correlation across species between cancer prevalence and body size (coined as Peto\u27s paradox) has attracted a lot of attention. Indeed, the disparity between this null hypothesis, where every cell is assumed to have an identical probability to undergo malignant transformation, and empirical observations is particularly important to understand, due to the fact that it could facilitate the identification of animal species that are more resistant to carcinogenesis than expected. Moreover it would open up ways to identify the selective pressures that may be involved in cancer resistance. However, Peto\u27s paradox relies on several questionable assumptions, complicating the interpretation of the divergence between expected and observed cancer incidences. DISCUSSIONS: Here we review and challenge the different hypotheses on which this paradox relies on with the aim of identifying how this null hypothesis could be better estimated in order to provide a standard protocol to study the deviation between theoretical/theoretically predicted and observed cancer incidence. We show that due to the disproportion and restricted nature of available data on animal cancers, applying Peto\u27s hypotheses at species level could result in erroneous conclusions, and actually assume the existence of a paradox. Instead of using species level comparisons, we propose an organ level approach to be a more accurate test of Peto\u27s assumptions. SUMMARY: The accuracy of Peto\u27s paradox assumptions are rarely valid and/or quantifiable, suggesting the need to reconsider the use of Peto\u27s paradox as a null hypothesis in identifying the influence of natural selection on cancer resistance mechanisms

Hydraulically-actuated compliant revolute joint for medical robotic systems based on multimaterial additive manufacturing

IEEE International Conference on Robotics and Automation (ICRA), Montréal, Canada, janvier 2019 Research team : AV

Transforming Temporal Embeddings to Keypoint Heatmaps for Detection of Tiny Vehicles in Wide Area Motion Imagery (WAMI) Sequences

International audienceNowadays, due to its many applications, objects detection in wide area motion imagery (WAMI) sequences has received a lot of attention. Unlike natural images, object detection in WAMI faces unique challenges. Lack of appearance information due to the small size of objects makes object detection difficult for conventional methods. In addition, pixel noise, registration errors, sparse or densely populated objects, brings on pronounced artifacts which amplifies the difficulty of detection. This paper aims to address object detection problem in the presence of these issues by considering objects as keypoints in the relevant background and proposes a spatiotemporal anchor-free detector for tiny vehicles in WAMI images. Instead of background subtraction, a region of interest network refines large search space of sequences to indicates object clusters. For further investigation, clusters are encoded by a codebook which is learned through an unsupervised encoder-decoder network. To accurately generate the detections, a Transformer network is trained on cluster embeddings using groundtruth heatmaps that are described by Gaussian distribution rather than hard label annotation. The network is trained with a redesigned version of Focal loss comprising a shape prior regularizer which help the generated heatmaps to conform to the shape of the keypoints. Extensive experiments on WPAFB dataset demonstrate the high capability of our method for the detection of small vehicles where it achieves competitive performance when compared to the state-ofthe-art

Integrated SSFIP-Horn Antenna at 75 GHz

We present in this paper an integrated cavity-backed patch antenna operating at 75 GHz. The design was optimized using a full-wave software based on the integral-equation method. The antenna was realized using micromachining technologies on two wafers: a silicon one supporting a membrane and a radiating patch, and a Pyrex one constituting the feeding element. The measurements are in good agreement with the theoretical predictions.Universidad Politécnica Federal de Lausann

Sourcing obsidian: a new optimized LA-ICP-MS protocol

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry [LA-ICP-MS] is one of the most successful analytical techniques used in archaeological sciences. Applied to the sourcing of lithic raw materials, it allows for fast and reliable analysis of large assemblages. However, the majority of published studies omit important analytical issues commonly encountered with laser ablation. This research presents a new advanced LA-ICP-MS protocol developed at Southern Cross GeoScience (SOLARIS laboratory, Southern Cross University, Australia), which optimizes the potential of this cutting-edge geochemical characterization technique for obsidian sourcing. This new protocol uses ablation lines with a reduced number of assayed elements (specific isotopes) to achieve higher sensitivity as well as increased precision and accuracy, in contrast to previous studies working with ablation points and an exhaustive list of measured isotopes. Applied to obsidian sources from the Western Mediterranean region, the Carpathian basin, and the Aegean, the results clearly differentiate between the main outcrops, thus demonstrating the efficiency of the new advanced LA-ICP-MS protocol in answering fundamental archaeological questions

Microevolution of bank voles (Myodes glareolus) at neutral and immune-related genes during multiannual dynamic cycles : Consequences for Puumala hantavirus epidemiology

Understanding howhost dynamics, including variations of population size and dispersal, may affect the epidemiology of infectious diseases through ecological and evolutionary processes is an active research area. Here we focus on a bank vole (Myodes glareolus) metapopulation surveyed in Finland between 2005 and 2009. Bank vole is the reservoir of Puumala hantavirus (PUUV), the agent of nephropathia epidemica (NE, a mild form of hemorrhagic fever with renal symptom) in humans. M. glareolus populations experience multiannual density fluctuations that may influence the level of genetic diversity maintained in bank voles, PUUV prevalence and NE occurrence. We examine bank vole metapopulation genetics at presumably neutral markers and immunerelated genes involved in susceptibility to PUUV (Tnf-promoter, Tlr4, Tlr7 and Mx2 gene) to investigate the links between population dynamics, microevolutionary processes and PUUV epidemiology. We show that genetic drift slightly and transiently affects neutral and adaptive genetic variability within the metapopulation. Gene flow seems to counterbalance its effects during the multiannual density fluctuations. The low abundance phase may therefore be too short to impact genetic variation in the host, and consequently viral genetic diversity. Environmental heterogeneity does not seem to affect vole gene flow, which might explain the absence of spatial structure previously detected in PUUV in this area. Besides, our results suggest the role of vole dispersal on PUUV circulation through sex-specific and density-dependent movements. We find little evidence of selection acting on immune-related genes within this metapopulation. Footprint of positive selection is detected at Tlr-4 gene in 2008 only. We observe marginally significant associations between Mx2 genotype and PUUV genogroups. These results show that neutral processes seem to be the main factors affecting the evolution of these immune-related genes at a contemporary scale, although the relative effects of neutral and adaptive forces could vary temporally with density fluctuations. Immune related gene polymorphism may in turn partly influence PUUV epidemiology in this metapopulation. (C) 2016 Published by Elsevier B.V.Peer reviewe