Search

Most phytophagous insect species exhibit a limited diet breadth and specialize on a few or a single host plant. In contrast, some species display a remarkably large diet breadth, with host plants spanning several families and many species. It is unclear, however, whether this phylogenetic generalism is supported by a generic metabolic use of common host chemical compounds (‘metabolic generalism’) or alternatively by distinct uses of diet-specific compounds (‘multi-host metabolic specialism’)? Here, we simultaneously investigated the metabolomes of fruit diets and of individuals of a generalist phytophagous species, Drosophila suzukii, that developed on them. The direct comparison of metabolomes of diets and consumers enabled us to disentangle the metabolic fate of common and rarer dietary compounds. We showed that the consumption of biochemically dissimilar diets resulted in a canalized, generic response from generalist individuals, consistent with the metabolic generalism hypothesis. We also showed that many diet-specific metabolites, such as those related to the particular color, odor, or taste of diets, were not metabolized, and rather accumulated in consumer individuals, even when probably detrimental to fitness. As a result, while individuals were mostly similar across diets, the detection of their particular diet was straightforward. Our study thus supports the view that dietary generalism may emerge from a passive, opportunistic use of various resources, contrary to more widespread views of an active role of adaptation in this process. Such a passive stance towards dietary chemicals, probably costly in the short term, might favor the later evolution of new diet specializations.

Abstract Due to its high ecological validity, virtual reality (VR) technology has emerged as a powerful tool for mental health research. Despite the wide use of VR simulations in research on mental illnesses, the study of addictive processes through the use of VR environments is still at its dawn. In a systematic literature search, we identified 38 reports of research projects using highly immersive head-mounted displays, goggles, or CAVE technologies to provide insight into treatment mechanisms of addictive behaviors. So far, VR research has mainly addressed the roles of craving, psychophysiology, affective states, cognition, and brain activity in addiction. The computer-generated VR environments offer very realistic, dynamic, interactive, and complex real-life simulations requesting active participation. They create a high sense of immersion in users by combining stereoscopic three-dimensional visual, auditory, olfactory, and tactile perceptions, tracking systems responding to user movements, and social interactions. VR is an emerging tool to study how proximal multi-sensorial cues, contextual environmental cues, as well as their interaction (complex cues) modulate addictive behaviors. VR allows for experimental designs under highly standardized, strictly controlled, predictable, and repeatable conditions. Moreover, VR simulations can be personalized. They are currently refined for psychotherapeutic interventions. Embodiment, eye-tracking, and neurobiological factors represent novel future directions. The progress of VR applications has bred auspicious ways to advance the understanding of treatment mechanisms underlying addictions, which researchers have only recently begun to exploit. VR methods promise to yield significant achievements to the addiction field. These are necessary to develop more efficacious and efficient preventive and therapeutic strategies.

Experiments comparing native to introduced populations or distinct introduced populations to each other show that phenotypic evolution is common and often involves a suit of interacting phenotypic traits. We define such sets of traits that evolve in concert and contribute to the success of invasive populations as an invasion syndrome. The invasive Harlequin ladybird Harmonia axyridis displays such an invasion syndrome with, for instance, females from invasive populations being larger and heavier than individuals from native populations, allocating more resources to reproduction, and spreading reproduction over a longer lifespan. Invasion syndromes could emerge due to selection acting jointly and directly on a multitude of traits, or due to selection on one or a few key traits that drive correlated indirect responses in other traits. Here, we investigated the degree to which the H. axyridis invasion syndrome would emerge in response to artificial selection on either female body mass or on age at first reproduction, two traits involved in their invasion syndrome. To further explore the interaction between environmental context and evolutionary change in molding the phenotypic response, we phenotyped the individuals from the selection experiments in two environments, one with abundant food resources and one with limited resources. The two artificial selection experiments show that the number of traits showing a correlated response depends upon the trait undergoing direct selection. Artificial selection on female body mass resulted in few correlated responses and hence poorly reproduced the invasion syndrome. In contrast, artificial selection on age at first reproduction resulted in more widespread phenotypic changes, which nevertheless corresponded only partly to the invasion syndrome. The artificial selection experiments also revealed a large impact of diet on the traits, with effects dependent on the trait considered and the selection regime. Overall, our results indicate that direct selection on multiple traits was likely necessary in the evolution of the H. axyridis invasion syndrome. Furthermore, they show the strength of using artificial selection to identify the traits that are correlated in different selective contexts, which represents a crucial first step in understanding the evolution of complex phenotypic patterns, including invasion syndromes.

Background: During the lockdown, governmental restrictions resulted in changes to the day-to-day routines of many individuals. Some people appear to cope with stress by panic buying in an attempt to stockpile specific goods, resulting in empty supermarket shelves. Moreover, e-commerce experienced significant growth during this period. We aimed to investigate potential changes in shopping frequencies and preferred shopping type (offline/online) and their relationship with pandemic-specific anxiety and stress during the 2020 spring lockdown in Germany.Methods: To address this question, we assessed self-reported changes in shopping behavior in a German sample via an online survey conducted during April and May 2020.Results: A total of 3,122 adults were included in the analysis. Of the total sample, 35% reported no changes in their shopping behavior, 46.8% shopped less, while 18.2% shopped more during the lockdown. The groups differed with respect to sociodemographic variables, and those participants who were shopping more reported greater pandemic-related health fears and stress due to the restrictions. Moreover, they shopped online more often during the lockdown than the other two groups.Conclusion: While the majority of the sample reported no changes in their shopping behavior or even shopped less during the 2020 spring lockdown, a subgroup of individuals was shopping more during this time, especially food and drugstore products. It is important to understand which factors influenced individuals to shop more so that policy makers can target this group and prevent panic buying, especially during subsequent waves of infection. It is also important to inform vulnerable persons about the risk of developing a buying–shopping disorder.

Introduction Cardiomyopathies are a heterogeneous heart diseases group in terms of morphology and aetiology. Hypothesising a tropical specificity and given an absence of data in French Guiana, the primary objective of our study was to describe morphologies and aetiologies of cardiomyopathies observed at Cayenne General Hospital.Methods A cross-sectional study was conducted in Cayenne Hospital from 1 January 2009 to 1 June 2014 in the hospital database. Only patients with the definition of the European Society of Cardiology (ESC) were included, based on the first transthoracic ultrasonography found during the study period. Medical files were consulted.Results With 182 patients included, the prevalence of cardiomyopathies among heart diseases was estimated at 4.3% (95% CI 3.7% to 4.9%). Twelve patients had a familial or genetic aetiology (6.6%) and 170 a non-familial or non-genetic aetiology (93.4%). The morphological spectrum was: dilated for 114 patients (62.6%), hypertrophic for 27 (14.8%), unclassified for 1 (0.5%) and non-classifiable for 13 (7.1%). This group was constituted of patients with a systolic and/or diastolic functional impairment without morphological abnormality. The aetiological spectrum found 184 aetiologies including: 70.9% undetermined, 8.7% infectious (with 6.5% chagasic and 0.5% related with human immunodeficiency virus) and 6.0% with toxins.Conclusions Cardiomyopthies are a common and severe clinical problem. The frequency of infectious aetiologies and dilated impairment are arguments for cardiomyopathies with tropical particularities. However, the preponderance of undetermined aetiologies justifies the development of further research programmes.

Orthoptera are infected by about 60 species of gregarines assigned to the genus Gregarina Dufour, 1828. Among these species, Gregarina garnhami Canning, 1956 from Schistocerca gregaria (Forsskål, 1775) was considered by Lipa et al. in 1996 to be synonymous with Gregarina acridiorum (Léger 1893), a parasite of several orthopteran species including Locusta migratoria (Linné, 1758). Here, a morphological study and molecular analyses of the SSU rDNA marker demonstrate that specimens of S. gregaria and specimens of L. migratoria are infected by two distinct Gregarina species, G. garnhami and G. acridiorum, respectively. Validation of the species confirms that molecular analyses provide useful taxonomical information. Phenotypic plasticity was clearly observed in the case of G. garnhami: the morphology of its trophozoites, gamonts and syzygies varied according to the geographical location of S. gregaria and the subspecies infected.

Puumala virus (PUUV) in Europe causes nephropathia epidemica (NE), a mild form of hemorrhagic fever with renal syndrome (HFRS). The incidence of NE is highly heterogeneous spatially, whereas the geographic distribution of the wild reservoir of PUUV, the bank vole, is essentially homogeneous. Our understanding of the processes driving this heterogeneity remains incomplete due to gaps in knowledge. Little is known about the current distribution and genetic variation of PUUV in the areas outside the well-identified zones of NE endemicity. We trapped bank voles in four forests in French regions in which NE is considered non-endemic, but sporadic NE cases have been reported recently. We tested bank voles for anti-PUUV IgG and characterized the S segment sequences of PUUV from seropositive animals. Phylogenetic analyses revealed specific amino-acid signatures and genetic differences between PUUV circulating in non-endemic and nearby NE-endemic areas. We also showed, in temporal surveys, that the amino-acid sequences of PUUV had undergone fewer recent changes in areas non-endemic for NE than in endemic areas. The evolutionary history of the current French PUUV clusters was investigated by phylogeographic approaches, and the results were considered in the context of the history of French forests. Our findings highlight the need to monitor the circulation and genetics of PUUV in a larger array of bank vole populations, to improve our understanding of the risk of NE.

In Europe, Puumala virus (PUUV) is responsible for nephropathia epidemica (NE), a mild form of hemorrhagic fever with renal syndrome (HFRS). Despite the presence of its reservoir, the bank vole, on most of French territory, the geographic distribution of NE cases is heterogeneous and NE endemic and non-endemic areas have been reported. In this study we analyzed whether bank vole-PUUV interactions could partly shape these epidemiological differences. We performed crossed-experimental infections using wild bank voles from French endemic (Ardennes) and non-endemic (Loiret) areas and two French PUUV strains isolated from these areas. The serological response and dynamics of PUUV infection were compared between the four cross-infection combinations. Due to logistical constraints, this study was based on a small number of animals. Based on this experimental design, we saw a stronger serological response and presence of PUUV in excretory organs (bladder) in bank voles infected with the PUUV endemic strain. Moreover, the within-host viral diversity in excretory organs seemed to be higher than in other non-excretory organs for the NE endemic cross-infection but not for the NE non-endemic cross-infection. Despite the small number of rodents included, our results showed that genetically different PUUV strains and in a lesser extent their interaction with sympatric bank voles, could affect virus replication and diversity. This could impact PUUV excretion/transmission between rodents and to humans and in turn at least partly shape NE epidemiology in France.

In a context of unprecedented environmental crisis, protected areas are expected to play a central role. Although considerable work has been done to understand the effectiveness of different types of protected area, there has been limited investigation of how a combination of different types of protected area within a system affects its overall environmental outcomes. Defining and using the concept of environmental complementarity, the paper explores whether or not the presence of private, state and community protected areas in a landscape has a positive effect on biodiversity conservation outcomes. Based on a Kenyan case study, it emphasizes the important and currently undervalued role of state protected areas and shows that other types of protected area can be analyzed as being a support. It suggests there is a complex array of complementarities between community, state and private protected areas. Differences in management capacity, staff skills, social acceptability, access to financial resources, tourism products, ecological resources, etc. between types of protected area were found to drive additionality and synergistic complementarities that undeniably contribute to strengthening the overall protected area system and increasing its resilience, as well as its capacity to generate environmental outcomes. Keywords: Biodiversity, Protected area, Environmental complementarity, Strategies

Lanthanide-doped nanoparticles are widely investigated for their optical properties. However, the sensitivity of the lanthanide ions’ luminescence to the local symmetry, useful when investigating structural environments, becomes a drawback for optimized properties in the case of poorly controlled crystallinity. In this paper, we focus on β -NaYF4 nanorods in order to provide a detailed description of their chemical composition and microstructure. The combination of detailed XRD analysis and TEM observations show that strong variation may be observed from particles from a same batch of synthesis, but also when considering small variations of synthesis conditions. Moreover, also the nanorods observed by SEM exhibit a very nice faceted shape, they are far from being monocrystalline and present significant local deviation of crystalline symmetry and orientation. All these structural considerations, sensitively probed by polarized emission analysis, are crucial to analyze for the development of optimal systems toward the targeted applications.

Since 2006, the wood preservation laboratory of Cirad is accredited by COFRAC (French accreditation committee – accreditation No. 1-1686) for tests on the durability of wood and wood-based products and on protective efficacy of wood preservatives and termite control products. The metrological approach adopted by the wood preservation laboratory is a key factor on the continuous improvement of practices. Tests to determine the resistance against wood-destroying biological agents are the most difficult of all wood analysis tests. They are aimed at assessing and quantifying the impact of living organism, such as fungi and termites, on a lignocellulosic material. The extent of variability of this impact, which in turn is linked with the diversity of these organisms and of the material, can be readily determined. The validity and reliability of the findings therefore depend directly on the quality of the metrological process, including the choice of measurement devices, their management and compliance with international standards.

Introduction: Cardiomyopathies are a heterogeneous heart diseases group in terms of morphology and aetiology. Hypothesising a tropical specificity and given an absence of data in French Guiana, the primary objective of our study was to describe morphologies and aetiologies of cardiomyopathies observed at Cayenne General Hospital., Methods: A cross-sectional study was conducted in Cayenne Hospital from 1 January 2009 to 1 June 2014 in the hospital database. Only patients with the definition of the European Society of Cardiology (ESC) were included, based on the first transthoracic ultrasonography found during the study period. Medical files were consulted., Results: With 182 patients included, the prevalence of cardiomyopathies among heart diseases was estimated at 4.3% (95% CI 3.7% to 4.9%). Twelve patients had a familial or genetic aetiology (6.6%) and 170 a non-familial or non-genetic aetiology (93.4%). The morphological spectrum was: dilated for 114 patients (62.6%), hypertrophic for 27 (14.8%), unclassified for 1 (0.5%) and non-classifiable for 13 (7.1%). This group was constituted of patients with a systolic and/or diastolic functional impairment without morphological abnormality. The aetiological spectrum found 184 aetiologies including: 70.9% undetermined, 8.7% infectious (with 6.5% chagasic and 0.5% related with human immunodeficiency virus) and 6.0% with toxins., Conclusions: Cardiomyopthies are a common and severe clinical problem. The frequency of infectious aetiologies and dilated impairment are arguments for cardiomyopathies with tropical particularities. However, the preponderance of undetermined aetiologies justifies the development of further research programmes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)