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Same data, different analysts: variation in effect sizes due to analytical decisions in ecology and evolutionary biology
No full textInternational audienceAlthough variation in effect sizes and predicted values among studies of similar phenomena is inevitable, such variation far exceeds what might be produced by sampling error alone. One possible explanation for variation among results is differences among researchers in the decisions they make regarding statistical analyses. A growing array of studies has explored this analytical variability in different fields and has found substantial variability among results despite analysts having the same data and research question. Many of these studies have been in the social sciences, but one small "many analyst" study found similar variability in ecology. We expanded the scope of this prior work by implementing a large-scale empirical exploration of the variation in effect sizes and model predictions generated by the analytical decisions of different researchers in ecology and evolutionary biology. We used two unpublished datasets, one from evolutionary ecology (blue tit, Cyanistes caeruleus, to compare sibling number and nestling growth) and one from conservation ecology (Eucalyptus, to compare grass cover and tree seedling recruitment). The project leaders recruited 174 analyst teams, comprising 246 analysts, to investigate the answers to prespecified research questions. Analyses conducted by these teams yielded 141 usable effects (compatible with our meta-analyses and with all necessary information provided) for the blue tit dataset, and 85 usable effects for the Eucalyptus dataset. We found substantial heterogeneity among results for both datasets, although the patterns of variation differed between them. For the blue tit analyses, the average effect was convincingly negative, with less growth for nestlings living with more siblings, but there was near continuous variation in effect size from large negative effects to effects near zero, and even effects crossing the traditional threshold of statistical significance in the opposite direction. In contrast, the average relationship between grass cover and Eucalyptus seedling number was only slightly negative and not convincingly different from zero, and most effects ranged from weakly negative to weakly positive, with about a third of effects crossing the traditional threshold of significance in one direction or the other. However, there were also several striking outliers in the Eucalyptus dataset, with effects far from zero. For both datasets, we found substantial variation in the variable selection and random effects structures among analyses, as well as in the ratings of the analytical methods by peer reviewers, but we found no strong relationship between any of these and deviation from the meta-analytic mean. In other words, analyses with results that were far from the mean were no more or less likely to have dissimilar variable sets, use random effects in their models, or receive poor peer reviews than those analyses that found results that were close to the mean. The existence of substantial variability among analysis outcomes raises important questions about how ecologists and evolutionary biologists should interpret published results, and how they should conduct analyses in the future
Potential of Compound-Specific Isotope Analysis (CSIA) to Trace Galaxolide Reactivity and Origin
No full textInternational audienceGalaxolide, a synthetic musk widely used in commercial products, including sanitation products and personal care products, poses environmental risks. Its sources and transformation pathways in aquatic environments remain poorly understood. Compound-specific isotope analysis (CSIA) offers a promising method to trace the origin and transformation of organic micropollutants by analyzing their individual isotopic signatures in natural abundance. While CSIA has been applied to various contaminants, its use with personal care products containing persistent organic pollutants is less explored. This study investigated the potential of CSIA for galaxolide to elucidate both abiotic and biotic transformations and trace its origin in personal care products. Batch experiments simulating photodegradation under UVC light and biodegradation by the strain Priestia sp. in MM20 medium revealed no significant isotopic fractionation (Δ13C < 0.5‰). Despite the wide variation in the concentrations of galaxolide in personal care products, with some exceeding 15 g L-1, δ13C values alone did not allow discrimination between sources and origins. Further research is necessary to evaluate how various environmental processes, both abiotic and biotic, could affect the stable isotopic composition of galaxolide and other synthetic musks
Sire Hain et dame Anieuse - Édition, traduction et notes d'après le manuscrit BnF fr. 837
No full textÉdition, traduction et notes de Sire Hain et dame Anieuse d'après le manuscrit BnF fr. 83
Towards a consensus on the development of the aquatic curricula analysis tool using an ecosystem approach: a delphi method
No full textInternational audiencePhysical inactivity and drowning are two of the leading causes of death worldwide. While participation in aquatic physical activity can help reduce these public health challenges, it is crucial to equip young people with key water skills through a well-designed aquatic curriculum to protect them from drowning and engage them in the long term in aquatic physical activities. This study reports on the development of a tool to analyse aquatic curricula for 6-to-12-year-olds in Europe, addressing both aquatic health issues. Methods: Using a three-round Delphi method, 101 participants from eight European countries - including experts in teaching, organising and researching aquatic education - were asked to rate the relevance of criteria conceptualised through Bronfenbrenner’s ecological model. Results: 115 criteria were retained and grouped into eight categories: (1) curriculum management, (2) drowning epidemiology, (3) timetable, (4) location and equipment, (5) staff, (6) content, (7) assessment and (8) learners. The strong consensus on most of the criteria suggests that promoting physical activity and water safety are compatible goals. Conclusion: A well-designed aquatic curriculum, rooted in each level of the ecological model and organised through a multisystemic approach, can successfully achieve both objectives. The findings provide valuable insights for the design of aquatic safety promotion policies, as well as guidance for educators and policy makers to improve teaching strategies to increase physical activity while preventing drowning accidents.Contexte : L'inactivité physique et les noyades comptent parmi les principales causes de mortalité dans le monde. Si la participation à des activités physiques aquatiques peut contribuer à réduire ces enjeux de santé publique, il est crucial d'équiper les jeunes de compétences clés liées à l'eau grâce à un programme aquatique bien conçu, afin de les protéger contre les noyades et de les engager à long terme dans des activités physiques aquatiques. Cette étude présente le développement d’un outil permettant d’analyser les programmes aquatiques destinés aux enfants de 6 à 12 ans en Europe, en abordant les deux problématiques de santé aquatique.Méthodes : En utilisant une méthode Delphi en trois tours, 101 participants issus de huit pays européens – comprenant des experts en enseignement, en organisation et en recherche sur l’éducation aquatique – ont été invités à évaluer la pertinence de critères conceptualisés à travers le modèle écologique de Bronfenbrenner.Résultats : 115 critères ont été retenus et regroupés en huit catégories : (1) gestion du programme, (2) épidémiologie des noyades, (3) emploi du temps, (4) lieux et équipements, (5) personnel, (6) contenu, (7) évaluation et (8) apprenants. Le fort consensus sur la plupart des critères suggère que la promotion de l’activité physique et la sécurité aquatique sont des objectifs compatibles.Conclusion : Un programme aquatique bien conçu, enraciné dans chaque niveau du modèle écologique et organisé selon une approche multisystémique, peut atteindre avec succès ces deux objectifs. Les résultats fournissent des perspectives précieuses pour la conception de politiques de promotion de la sécurité aquatique, ainsi que des orientations pour les éducateurs et les décideurs politiques afin d'améliorer les stratégies d'enseignement visant à augmenter l'activité physique tout en prévenant les accidents de noyade
Sciences sociales et pluridisciplinarité dans la recherche sur les risques dits "naturels": Subordination de la connaissance et conditions de son dépassement
No full textTextes issus de colloque " Approches critiques de la dimension spatiale des rapports sociaux : débats transdisciplinaires et internationaux " tenu à la Maison de la Recherche en Sciences Humaines (MRSH) de l'Université de Caen Normandie du 26 au 28 juin 2019International audienc
Organic All‐Solid‐State Lithium Metal Battery Using Polymer/Covalent Organic Framework Electrolyte
No full textInternational audienceIn this work, we have designed an all‐organic and all‐solid‐state lithium metal battery based on 7,7,8,8‐tetracyano‐ p ‐quinodimethane (TCNQ) as the organic electroactive material and a COF (Covalent Organic Framework)/PEO (PolyEthylene Oxide) composite as solid electrolyte. The use of a solid electrolyte allows fixing the solubility problem of organic electroactive materials in classical liquid electrolytes. This is the first time an all‐solid‐state organic battery based on TCNQ versus lithium metal is reported, since no liquid additive was included in the formulation of the electrolyte. We obtained a reversible capacity of 88 mAh g −1 at the second discharge, and still 58 mAh g −1 at the tenth discharge. The redox processes were investigated by X‐ray Photoelectron Spectroscopy (XPS). We could evidence the involvement of the two lithiation steps of TCNQ (LiTCNQ and Li 2 TCNQ) in the reversible capacity. Optimization of the electrode manufacturing and formulation, and replacing the salt (LiI) by alternative ones opens the door to future improvements in the electrochemical performances. This study demonstrates the interest of COF‐type organic structures in the formulation of organic solid electrolytes
Effect of ligand variation on Mg alkoxyborate electrolytes: Does more fluorine help?
No full textInternational audienceMg fluorinated alkoxyborate-based electrolytes are promising candidates for rechargeable Mg batteries. In this work, we investigate a series of Mg alkoxyborates with a different degree of anion fluorination in terms of their physicochemical properties, Mg metal anode, and organic cathode electrochemical performance, as well as Mg metal/electrolyte interphase. The results underscore the significant influence of the anion fluorination degree on the transport properties of electrolytes. Notably, the anion with the lowest degree of fluorination exhibits one order of magnitude lower ionic conductivity than electrolytes with more fluorinated anions. Interestingly, the same electrolyte demonstrates the second-best electrochemical performance, with the Mg plating/stripping efficiency close to 99 %. XPS analysis of the Mg metal deposit surface reveals that the high Coulombic efficiency is associated with a high amount of boron-containing species in the metal/electrolyte interphase of the best-performing electrolytes. Additionally, it has been noted that inorganic boron species result in a larger interfacial resistivity for Mg plating/stripping compared to boron species in an organic environment. Testing in combination with organic cathodes reveals the superior performance of the most fluorinated electrolyte in terms of cycling stability and Coulombic efficiency. The present work underlines the interplay of different phenomena affecting the overall electrochemical performance of electrolytes and strategies for the design of next-generation Mg electrolytes
