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Organic aerosol (OA) from natural or anthropogenic origin can be directly emitted into the atmosphere (primary organic aerosols, POA) or formed by secondary processes via the oxidation of volatile organic compounds (VOC). However, the formation pathways and their chemical composition of these secondary organic aerosols (SOA), which may contribute up to 90% of the OA mass, are not well understood to date, which is problematic due to the relevance of SOA on climate. To address this issue, this study uses a tracer-based approach to identify and quantify the contribution of different anthropogenic/biogenic VOCs precursors to the SOA formation. To do so, we combine experiments in a large scale atmospheric simulations chamber, CESAM (which means Multiphase Atmospheric Experimental Simulation Chamber), and field measurements during the ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) campaign conducted in the Paris area in summer 2022. This approach provides both a mechanistic study of the oxidation of targeted VOCs in simulated and controlled rural/urban atmospheres and the identification of targeted tracers in the real atmosphere, to quantify their concentrations in ambient air.The ACROSS dataset consists in atmospheric samples of submicron aerosols collected twice a day (day and night) in the urban area of Paris and the Rambouillet forest on the south-west of Paris, as well as samples collected onboard the Safire ATR-42 research aircraft on low-level flights targeting the evolution and dilution of the Paris urban plume. The CESAM chamber dataset consists in samples of SOA generated by the OH oxidation of toluene/ m-xylene in various conditions.Filters are analyzed to provide with the chemical composition at the molecular scale by SFE-GC-MS (Supercritical Fluid Extraction Gas Chromatography- Mass Spectrometry) and UPLC-QTOF-MS (Ultra Performance Liquid Chromatography Time of Flight Mass Spectrometry). The organic mass and chemical speciation are obtained by aerosol mass spectrometry and the organic carbon (OC) concentrations by thermal-optical analysis.The first results of the ambient samples of Paris revealed that the OC concentration varied between 0.69 ± 0.07 and 9.48 ± 0.51 µgC/m3, which correspond to the 28% and 53% of the total mass of the submicron aerosols, for background and polluted (fire) conditions, respectively. These diverse conditions are favorable to trace the compounds identified during the simulation chamber experiments, such as benzoic acid, succinic acid, and 2-methyl-4-nitrophenol. These attempts will be presented and discussed in order to determine the contribution of specific precursors to SOA formation.

This study draws on lexical semantics to support a discourse analysis perspective (Gosselin 2018; Galatanu 2018). It examines the use of the French noun artère ‘artery’ (a common word from the lexicon (Maingueneau 2021)) to refer to a street-like entity (street, avenue, boulevard, etc.). The empirical investigation was based on an analysis of 150 utterances (extracted from three full-text databases). On the one hand, the study shows that selecting artère to refer to a street-like entity is a discursive strategy targeting a significant representation of the referent, especially when this referent is not a prototypical urban street. On the other hand, it supports the idea that this discursive choice strongly relies on the lexical signification of artère (Bertin 2018).

Cette étude prolonge un travail de recherche sur la signification des noms des parties du corps humain (Npc) (Bertin, 2018). On s'intéresse à la construction illustrée par Colin a le front de venir à cette réunion (NPV). Après un inventaire des Npccompatibles avec NPV, on procède à une analyse sémantique : d'une part, on cerne le sens de NPV (en se focalisant sur la contribution du Npc) et, d'autre part, on tire profit de cette première étape pour l'analyse sémantique des Npceux-mêmes.

From January 2011 to March 2018, 26 patients aged from 20 to 80 years old reported being sick in France after eating sea figs of the genus Microcosmus. The patients had symptoms evoking a cerebellar syndrome: blurred or double vision, ataxia and dizziness, asthenia, headache, muscle cramps, paresthesia and digestive disorders (nausea, vomiting and diarrhea). Three of the 18 food poisoning events recorded by the Poison Control Center in Marseille and involving four patients were further investigated as the meal leftovers were collected and analyzed. A previous study ruled out the presence of the regulated lipophilic marine toxins after high-resolution mass spectrometry, but further analyses were required to look for hydrophilic cyanotoxins. The sea fig leftovers from food poisoning case Numbers 1 (January 2011), 6 (December 2012) and 17 (March 2018) of this published case series were analyzed by hydrophilic interaction liquid chromatography coupled to low- and high-resolution mass spectrometry to investigate the presence of hydrophilic cyanotoxins. The sea fig samples showed anatoxin-a (ATX-a) concentrations ranging from 193.7 to 1240.2 &micro, g/kg. The sea fig control sample analyzed was also contaminated with ATX-a but in a much smaller concentration (22.5 &micro, g/kg). To the best of our knowledge, this is the first report of human food poisoning involving ATX-a as the possible causative toxin where the cyanotoxin could be unequivocally identified.

A QuEChERS extraction method followed by HPLC-MS/MS analysis was developed to simultaneously analyze chlordecone and its metabolite chlordecol in animal livers. The overall method was validated with accuracy profiles according to the French Standard NF V03-110 and European Union guidelines. The validation was performed on bovine, ovine and porcine liver samples. Linearity, matrix effect, accuracy, within-laboratory repeatability, specificity, LOQ, Q/q relative ion intensities, and uncertainty were reported. Recoveries were between 70% and 120%. LOQs of 1.36 µg chlordecone kg-1 and 2.50 µg chlordecol kg-1 of fresh liver were found. Twelve contaminated livers of bovine, ovine and porcine origin from the French West Indies or samples from in vivo studies were analyzed. In these liver samples from contaminated animals, chlordecone was quantified at concentrations higher than the maximum residue limit and chlordecol in very low amounts in all the samples. In addition, these results confirm that chlordecone can be metabolized in ruminant species.

Chlordecone (CLD) is a Persistent Organic Pollutant used between 1972 until 1993 in the French West Indies (FWI). Due to its persistence and extensive application, a quarter of the total local agricultural acreage is still moderate to heavily polluted. In consequence, livestock may be contaminated at various levels. This is a major public health concern, particularly for local consumers. In order to better understand the fate of CLD in livestock organisms, in vivo studies are required. There is no information available about its metabolism and elimination in ruminants, common livestock in the FWI. To be able to monitor the fate of chlordecone and its metabolites in livestock and to assess if the compounds could be released in the environment, urinary and fecal samples were logically targeted. In order to reach this goal, robust and validated analytical methods are required. For this purpose, Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction methods were validated to analyze CLD and its metabolites in the urine and feces. The analysis was carried using liquid phase chromatography with tandem mass spectrometry and validated according to French standard NF V03-110 and SANTE guidelines. Matrix effect, Accuracy, within-laboratory repeatability, specificity, Q/q relative ion intensities and uncertainty were reported. Recoveries between 70% and 120% were obtained from urine and feces. The limits of quantification (LOQ) in urine samples were 0.1 μg CLD L−1, 0.1 μg total CLD (CLD and its conjugates)·L−1, 1.3 μg CLDOH L−1 and 2.4 μg total CLD (chlordecol and its conjugates) L−1 of urine. LOQ in fresh feces were 3.2 μg CLD kg−1 and 5.8 μg CLDOH kg−1. Contaminated urinary and fecal samples from ewes were analyzed to confirm the relevance of the methods. In urine, CLD and conjugated CLDOH could be quantified whereas only free CLD and free CLDOH were found in feces. These methods are essential for future toxicokinetic studies and also to estimate the environmental contamination.

International audience; Do tunnels have bouches (in French) ? Mainly, this articleaims at depicting “the semantic identity” of the French noun bouche(mouth). A lexicographic divergence about the semantic affinity betweenbouche and the French noun tunnel provides a starting point. Indeed, theidea is to figure out this disagreement by the means of a semanticdescription of bouche. In section 1, we give some clues about thetheoretical and methodological frames of our work. Then, we describe thenoun bouche viewed as a polysemic word. At first, we investigate thisnoun's different meanings in order to set its different acceptations (oracceptions). Secondly, we build a semantic analysis, rooted in two mainacceptations, aiming at discovering a semantic invariant suiting the nounbouche. A conclusion about this analysis leads to answer the question : inFrench, do tunnels have bouches ?; Cet article vise principalement à caractériser « l'identitésémantique » du nom bouche. Une divergence lexicographique concernantla compatibilité sémantique des noms bouche et tunnel sert de point dedépart. En effet, l'idée est de comprendre ce désaccord en s'appuyant surune analyse sémantique de bouche. Après avoir évoqué les cadresthéorique et méthodologique dans lesquels s'ancre ce travail, nous étudionsle nom bouche envisagé comme une unité linguistique polysémique. Dansun premier temps, nous explorons le potentiel de variation sémantique dece nom pour en décrire les différentes acceptions. Puis, à partir de deuxacceptions considérées comme principales, nous construisons l'analysedans la perspective de mettre au jour un invariant sémantique pour le nombouche. Un bilan de cette analyse conduit à proposer une réponse à laquestion : les tunnels ont-ils des bouches ?

Background The dentitions of extinct organisms can provide pivotal information regarding their phylogenetic position, as well as paleobiology, diet, development, and growth. Extant birds are edentulous (toothless), but their closest relatives among stem birds, the Cretaceous Hesperornithiformes and Ichthyornithiformes, retained teeth. Despite their significant phylogenetic position immediately outside the avian crown group, the dentitions of these taxa have never been studied in detail. To obtain new insight into the biology of these ‘last’ toothed birds, we use cutting-edge visualisation techniques to describe their dentitions at unprecedented levels of detail, in particular propagation phase contrast x-ray synchrotron microtomography at high-resolution. Results Among other characteristics of tooth shape, growth, attachment, implantation, replacement, and dental tissue microstructures, revealed by these analyses, we find that tooth morphology and ornamentation differ greatly between the Hesperornithiformes and Ichthyornithiformes. We also highlight the first Old World, and youngest record of the major Mesozoic clade Ichthyornithiformes. Both taxa exhibit extremely thin and simple enamel. The extension rate of Hesperornis tooth dentine appears relatively high compared to non-avian dinosaurs. Root attachment is found for the first time to be fully thecodont via gomphosis in both taxa, but in Hesperornis secondary evolution led to teeth implantation in a groove, at least locally without a periodontal ligament. Dental replacement is shown to be lingual via a resorption pit in the root, in both taxa. Conclusions Our results allow comparison with other archosaurs and also mammals, with implications regarding dental character evolution across amniotes. Some dental features of the ‘last’ toothed birds can be interpreted as functional adaptations related to diet and mode of predation, while others appear to be products of their peculiar phylogenetic heritage. The autapomorphic Hesperornis groove might have favoured firmer root attachment. These observations highlight complexity in the evolutionary history of tooth reduction in the avian lineage and also clarify alleged avian dental characteristics in the frame of a long-standing debate on bird origins. Finally, new hypotheses emerge that will possibly be tested by further analyses of avian teeth, for instance regarding dental replacement rates, or simplification and thinning of enamel throughout the course of early avian evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0753-6) contains supplementary material, which is available to authorized users.

International audience; In the field of mass sensing, there is an ever growing interest in the development of ultrasensitive MEMS devices for agro-food, environment, safety or health. Within this context, mode localization in an array of coupled resonators has been studied and implemented for a fewyears due to its high sensitivity to mass perturbation. However, this phenomenon requires a few conditions often hard to gather mainly due to microfabrication flaws and the devices geometry. In this paper, we present a device able to generate mode localization using a single piezoelectric resonator connected in closed loop to a hardware that simulates in real time the other resonators. Its main strengths are its full tunability and adaptibility to the geometry of the resonators.