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P03-04: Safety evaluation of can's polyester coatings using and approaches
No full textInternational audienceCan's internal coatings may represent a source of food contamination due to the migration of Non-Intentionally Added Substances (NIAS) from coatings into food matrix. NIAS are contaminants, degradation products, or impurities and their presence and formation are mostly unknown. Among NIAS, linear and cyclic oligoesters could possibly migrate from polyester-based coatings. Their identification and quantification are challenging due to the lack of analytical standards. In addition, there is a gap of knowledge available in the literature regarding their toxicity.The aim of this study is to evaluate the safety of a can's polyester coatings to protect consumers from chemical exposure. Five polyestercoated metal plates were extracted by acetonitrile (ACN) and ethanol-95% (EtOH) in migration cells. Samples were then concentrated and analyzed by liquid chromatography–high resolution mass spectrometry in a non-targeted way. Four cyclic oligoesters composed of tricyclodecanedimethanol (TCDDM), 1,4-butanediol (BD), and terephthalic acid (PA) were identified in all replicates: c(2BD+TCDDM+3PA), c(BD+ 2TCDDM+3PA), c(3TCDDM+3PA), c(2TCDDM+2PA). Considering TCDDM isomers and potential BD and PA isomers (1,3-butanediol and orthophthalic acid), 147 possible structural isomers were designed for four oligoesters. Several in silico predictive tools (VEGAHUB, SARAH, DEREK, Lazar, ADMETlab 2.0, Protox-II) were used to predict the mutagenicity and carcinogenicity of these molecules. All structural isomers showed negative prediction in all in silico tools for in vitro mutagenicity, and positive prediction for carcinogenicity in VEGAHUB, meaning that they can be potential tumor promotors. Lazar, ADMETlab 2.0, Protox-II also showed positive prediction for carcinogenicity for most of isomers of c(2BD+TCDDM+3PA) and c(BD+2TCDDM+3PA). Furthermore, the majority of structural isomers of four oligoesters showed 3 alerts for genotoxic carcinogenicity rule based on toxicophore rules using ADMETlab 2.0.To confirm predictive in silico alert, extracts were tested in vitro with the Cell Transformation Assay (CTA). All ACN and EtOH extracts were negative in the initiation assay of CTA, however, one of the EtOH extracts was equivocal in the promotion assay
Interaction between Armenian clay-based ceramics and model wine during storage
No full textInternational audienceWine made or stored in clayware ceramic pots attracts the attention of consumers, but this practice is less studied than when classic stainless steel tanks or wood barrels are used. It is known that wine can be influenced by the container in which it is aged. To analyse the influence of ceramics on the chemical composition of wine, Armenian clay-based ceramic tablets were immersed in model wine and aged from 1 hour up to 16 months at 25 °C in darkness. The concentrations of 26 elements (namely: Al, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, W and Zn) in 19 samples were determined by ICP-AES analysis. Proton time domain NMR relaxometry was used to characterise the iron redox processes that occurred in the model wine in contact with a ceramic. A fast increase in the pH of the model wine in contact with the bare ceramic tablet (from 2.35 to 5) was recorded in 4 days. The coating of the ceramic tablets with beeswax showed a significant effect on the interaction between the model wine and the ceramic
Impact des digestats de méthanisation sur la qualité microbiologique des sols agricoles
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Host‐associated genetic differentiation and origin of a recent host shift in the generalist parasitic weed Phelipanche ramosa
No full textInternational audienceBranched broomrape, Phelipanche ramosa (L.) Pomel, is a globally distributed parasitic weed of economic importance. In Europe, where it is native, it can infest several crops, notably tomato, tobacco, and hemp. In western France, it has recently adapted to a new host crop, oilseed rape, causing substantial damage. The aim of this study was to investigate the evolutionary relationships and genetic differentiation among P. ramosa populations infesting different hosts. We collected 1611 P. ramosa samples from 109 fields cultivated with six different crops (oilseed rape, tobacco, hemp, tomato, lentil, and celery) and distributed among six European countries. All samples were genotyped for ten microsatellite loci and a subset of samples was sequenced for two nuclear genes and two chloroplast genes. Genetic differentiation among populations was high (FST = 0.807) and mainly driven by differentiation among different host crops, with no significant geographic structure. Genetic structure analysis identified up to seven biologically meaningful clusters that matched with host crops of origin. Reconstructed networks of sequence haplotypes and multilocus SSR genotypes showed a large genetic divergence between samples collected on oilseed rape and samples collected on other crops. The phylogeny inferred from DNA sequences placed samples collected from oilseed rape as a basal lineage. Approximate Bayesian Computations were used to compare different evolutionary scenarios of divergence among the three main genetic clusters, associated, respectively, with oilseed rape, tobacco, and hemp as host crops. The best-supported scenario indicated that P. ramosa infesting oilseed rape derived recently from an ancient, unknown lineage. Our results suggest that a more complete description of the genetic diversity of P. ramosa is still needed to uncover the likely source of the recent adaptation to oilseed rape and to anticipate future new host shifts
Relocalisation des filières alimentaires
No full textL'émission radio animée par des étudiants d'Institut Agro Dijon porte sur la relocalisation des filières alimentaires. Le sujet est traité à partir des travaux d'études et de recherche conduis par Denis Lépicier, Ingénieur de Recherche au CESAER à Dijon. Après avoir défini ce que sont les filières territoriales et leur contexte d'émergence, sont présentés les résultats de projets de recherche en Bourgogne - Franche-Comté dont les impacts de filières sur le territoire
Effects of chemical inputs, plant genotype and phenotypic plasticity on soil carbon storage by wheat root systems
No full textInternational audiencePurposeThe main goal of this study was to determine if ancient wheat varieties could store more carbon than modern ones in the presence or absence of inputs, due to a likely bigger and deeper root system and a slower mineralization rate.MethodsWe conducted a field experiment with four modern and four ancient varieties (released before 1960 and often grown without inputs), with and without chemical inputs (nitrogen, herbicide and fungicide taken as a single factor). Root morphology was assessed by image analysis, potential catabolic activities of fructose, alanine, citric acid by MicroResp™ and overall CO2 emissions by incubating soil and roots from each modality for 60 days.ResultsThe breeding type did not affect root traits, substrates respiration nor CO2 emissions in our environmental conditions. The application of inputs did not affect root traits but influenced the respiration of specific substrates and CO2 emissions. The most noticeable response was due to the “breeding type x inputs” interaction: inputs increased CO2 emissions from soil and root tissues of ancient varieties by 19%, whereas no effect was observed for modern varieties.ConclusionTaken together, our results did not support the hypothesis that ancient varieties could be more performant than modern ones in storing carbon in our experimental conditions. Increased CO2 emissions by ancient varieties in the presence of inputs showed that ancient and modern varieties differed in their phenotypic plasticity
Mixture of longitudinal factor analyzers and their application to the assessment of chronic pain
No full textInternational audienceMultivariate longitudinal data are used in a variety of research areas not only because they allow to analyze time trajectories of multiple indicators, but also to determine how these trajectories are influenced by other covariates. In this article, we propose a mixture of longitudinal factor analyzers. This model could be used to extract latent factors representing multiple longitudinal noisy indicators in heterogeneous longitudinal data and to study the impact of one or several covariates on these latent factors. One of the advantages of this model is that it allows for measurement non-invariance, which arises in practice when the factor structure varies between groups of individuals due to cultural or physiological differences. This is achieved by estimating different factor models for different latent classes. The proposed model could also be used to extract latent classes with different latent factor trajectories over time. Other advantages of the model include its ability to take into account heteroscedasticity of errors in the factor analysis model by estimating different error variances for different latent classes. We first define the mixture of longitudinal factor analyzers and its parameters. Then, we propose an EM algorithm to estimate these parameters. We propose a Bayesian information criterion to identify both the number of components in the mixture and the number of latent factors. We then discuss the comparability of the latent factors obtained between subjects in different latent groups. Finally, we apply the model to simulated and real data of patients with chronic postoperative pain
Quand l’apprenant se fait formateur : les jeux didactiques transformés par les élèves-ingénieurs lors d’une simulation à l’activité d’encadrement en atelier technologique
No full textLa communication faite s'inscrit dans le symposium 2 axe 1 intitulé " La simulation en formation professionnelle : activités des formateurs dans le continuum situationnel" coordonné par Natacha Dangouloff et Sébastien ChalièsInternational audienceLa présente recherche ce centre sur un segment de curriculum de la dominante « MANPRO » qui prépare des élèves-ingénieurs aux métiers de la production industrielle agroalimentaire. Cette séquence de leur formation revêt la forme d’une simulation dont le scénario est simple : réaliser un ordre de production en encadrant des opérateurs professionnels sur une ligne de production véritable mais située en lycée professionnel. Une de ses originalités réside dans le fait que les élèves-ingénieurs sont invités à endosser des rôles professionnels (comme responsables de la production ou de la qualité ou encore comme auditeurs) qui, parce qu’ils répondent à des logiques métiers différentes et parfois antagonistes, génèrent des dynamiques de coopération plus ou moins favorables aux apprentissages.Pris par le scénario de la simulation et parfois confrontés à ses manques de précision, les élèves-ingénieurs se trouvent engagés dans des jeux épistémiques[1] par lesquels ils jouent, entre eux, à faire ce qui est à apprendre et participent par là même aux transformations des contrats et milieux didactiques imaginés et mis en place par les formateurs.Les premiers résultats de cette recherche empirique à visée compréhensive, s’attacheront à présenter les différents types de jeux à l’œuvre entre les apprenants ainsi que leurs effets sur les apprentissages. Il s’agira en particulier de (i) mettre en exergue sur quels types de capacités épistémiques les apprenants se focalisent et de (ii) décrire les différentes configurations d’équilibration des dialectiques didactiques observées.[1] En référence à la TACD : Théorie de l’action conjointe en didactiqu
Assessment of Nitrogen Nutrition Index of Winter Wheat Canopy from Visible Images for a Dynamic Monitoring of N Requirements
No full textInternational audienceHand-held chlorophyll meters or leaf-clip-type sensors indirectly and instantaneously measure leaf N content. They can provide an N nutrition index (NNI) value that is crucial information foradjusting the amount of N fertilizer to the actual N status of the plant. Although these measurements are non-invasive and non-destructive, they require numerous repetitions at the canopy scale. The objective of this work was to explore the potential of visible images to predict nitrogen status in winter wheat crops from estimating NNI and to compare these results with those deduced from classical methods. Based on a dark green colour index (DGCI), which combines hue, saturation and brightness, a normalized DGCI (nDGCI) was proposed as the ratio between the measurements of the study microplot and those of the over-fertilized microplot. The methodology was performed on winter wheat microplots with a nitrogen gradient. Half of the microplots were grown with a single cultivar (LG Absalon) and the other half with a mixture of four wheat cultivars. The impact of optical device (digital camera or smartphone), the white balance (Manual or Automatic), the crop growth stage (two-nodes or heading) and cultivars (single or mixed) on the relationship between (DGCI, nDGCI) and NNI was evaluated. The results showed a close correlation between the nDGCI values and the NNI_NTester values, especially on a single cultivar (LG Absalon; R2 = 0.73 up to 0.91 with smartphone). It suggested that the relationship is highly sensitive to the wheat cultivar. This approach with no specific calibration of images is promising for the estimation of N requirements in wheat field
Odor-evoked memories: The importance of choosing the right odor
No full textInternational audienceOdors are known to entertain a special link with memory. However, the scientific literature investigating odors as powerful reminders of past experiences shows mixed results. This can be partly due to poor consistency in methodological approaches, especially concerning stimuli choice. Here, we presented 64 odorants to 130 young adults and asked them to freely report what each odor evoked to them. Responses were sorted in 1) mere odors' identification attempts and 2) any other memory-based verbal content, whose phenomenological properties were analyzed quantitatively and qualitatively. As expected, only a limited number of odors managed to spontaneously trigger high-quality autobiographical memories. In most cases, people engage in an odor identification task or evoke unspecific memory contents. We finally selected a pool of 20 odors as a function of the memory contents they're more likely to trigger. This enabled us to formulate recommendations for professionals (researchers or practitioners) performing olfactory-based memory stimulation