Drainage network analysis to comprehend structural sediment (dis)connectivity in wine-growing Beaujolais (France)

International audienceDrainage infrastructure is an important element of the agricultural landscape, influencing hydro-sedimentary transfers from plots to rivers. The objective of this article is to demonstrate how the description of the main characteristics of drainage networks allows a better understanding of sediment (dis)connectivity. This study focuses on an 8 km2 catchment in the Beaujolais vineyards (France) that is characterized by a complex drainage network. We applied methods using field surveys, a geographical information system and graph theory to map and analyse how such man-made infrastructures may act as barriers, buffers or shortcuts. The catchment shows dense and complex drainage networks characterized by sediment trapping strategies in the upper slopes, and flow concentration and export in the lower slopes. The results exemplify winegrowers’ strategies to disconnect sediments sources from the river to preserve soil resources

Sheller, l'intime sous le choral : rayonnement d'un homme heureux ?

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Ultrafast µLIBS Imaging for the multiscale mineralogical characterization of pegmatite rocks

International audienceThis article presents an innovative application of kHz regime μLIBS – Laser-Induced Breakdown Spectroscopy) for generating detailed compositional maps of geological samples. The method effectively covers large areas (tens of cm²) rapidly while maintaining high lateral resolution (below 20 µm), producing some of the most extensive LIBS compositional images to date, with a size of 10 million pixels. Employing elemental-based images, we developed a direct methodology for mineral phase identification through mask-creation operations and logical relationships. This approach was successfully applied to reconstruct the mineralogical map of a Li-ore from the west-European Variscan belt, identifying 14 different mineral phases, including economically valuable ones like lepidolite, cassiterite, and columbite-group minerals. Furthermore, based on the reverse normative calculation, the chemical composition of the sample was calculated from the mineral phases previously obtained. The kHz μLIBS approach marks a significant advancement in elemental and phase imaging, especially pertinent to geological applications, providing comprehensive petro-geochemical insights, essential for a fast geological characterization

Comprehensive photophysical and nonlinear spectroscopic study of thioanisolyl‐picolinate triazacyclononane lanthanide complexes

International audienceAbstract Detailed photophysical studies of luminescent lanthanide complexes are presented and elaborated using a newly developed thioanisolyl‐picolinate antenna and the related tacn macrocyclic ligand. The new ligand proved to sensitise Nd(III), Sm(III), Eu(III) and Yb(III) emission. Eu(III) complex showed complete energy transfer, yielding high quantum yield (44 %) and brightness, while the Tb(III) analogue underwent a thermally activated back‐energy transfer, resulting in a strong oxygen quenching of the triplet excited state. Transient absorption spectroscopy measurements of Gd(III), Tb(III) and Eu(III) compounds confirmed the sensitization processes upon the charge‐transfer antenna excitation. The triplet excited state lifetime of the Tb(III) complex was 5‐times longer than that of the Gd(III) analogue. In contrast, the triplet state was totally quenched by the energy transfer to the 4f ‐metal ion in the Eu(III) species. Nonlinear two‐photon absorption highlighted efficient biphotonic sensitization in Eu(III) and Sm(III) complexes. In case of the Nd(III) compound, one‐photon absorption in 4f–4f transitions was predominant, despite the excitation at the antenna two‐photon band. This phenomenon was due to the Nd(III) 4f–4f transitions overlapping with the wavelength‐doubled absorption of the complex

Modeling the polychromism of oxide minerals: The case of alexandrite and cordierite

International audienceIn this work, we investigate the spectroscopic properties of photochromic alexandrite and cordierite by TD‐DFT. The objective is to assess the TD‐DFT for the simulation of pleochroism (change of color depending on the crystallographic direction of the observation) and the change of color as a function of the light source. For these simulations, we compared an embedding where dangling bonds are saturated by hydrogen atoms and an electrostatic embedding. The electrostatic embedding provided numerically more stable results and allowed a good reproduction of the pleochroism of cordierite, based on a Fe 2+ ‐Fe 3+ intervalence charge transfer transition. However, the pleochroism of alexandrite is not as well reproduced, suggesting that TD‐DFT has some difficulties to reproduce the anisotropy of the transition dipole moment, an aspect that is not deeply documented in the literature

Connaître une ascension sociale en devenant entrepreneur de nettoyage et désinfection après décès

International audienceEncore peu connue en France, l’activité de nettoyage et désinfection après décès est une spécialité professionnelle relativement facile d’accès pour des hommes de classes populaires ou de petites classes moyennes puisqu’elle n’exige ni diplôme spécifique ni capital économique important. L’article montre qu’on ne devient pas entrepreneur de nettoyage et désinfection des lieux après décès à la fin de sa formation initiale, mais en cours de carrière en suivant l’un des trois parcours types de mobilité professionnelle : une mobilité interne au sein du secteur du nettoyage, une reconversion entre secteurs limitrophes ou une bifurcation. L’accès au statut d’indépendant et à une activité valorisable par des compétences techniques et des savoir-être spécifiques rend possible une trajectoire promotionnelle et un rapport satisfaisant à l’activité

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

International audienceSub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

CeO2-based peelable gel for neutralization and skin decontamination toward chemical warfare agents

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