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Report on the 2023 Season of the Madâ’in Sâlih Archaeological Project
No full textThis 126 pages report presents the work done in 2023 by the Madain Salih Archaeological Project (MSAP) at the site of Hegra, in the north-west of Saudi Arabia. Half of it is devoted to the Hegra-Tayma camel caravan survey, with contributions on the archaeology and epigraphy between the two oases, on A. Jaussen and R. Savignac, and on the camels in the rock drawings.The other half contains contributions on the pottery, on the Arabic inscriptions in the Jabal Ithlib, and on the protection strategies used in 2023 in the various areas excavated by the MSAP in the so-called residential area
Multi-objective optimization of rainwater infiltration infrastructures along an urban–rural gradient
No full textInternational audienceMany cities are developing infiltration infrastructures aimed at restoring natural hydrological processes. Among those, Nature-Based Solutions (NBS) can generate co-benefits, which contribute to cities’ adaptation to climate change. However, choosing optimal locations for infiltration infrastructures within limited available urban space is a complex spatial problem. It requires taking into account spatial patterns of infiltration potential as well as urban-rural gradients of costs and benefits. To address this, we apply a multi-objective optimization on a simple monocentric model city designed to give generic insights into location choices. We test a series of hypotheses: in comparison with a reference situation, we test the impact of the impossibility to infiltrate rainwater in city centers, the impact of substitution effects due to the presence of urban parks, and the possibility to mix NBS with grey infrastructures. The solutions reveal two polar strategies: locating infrastructures in the city center with higher co-benefits despite higher opportunity costs, or selecting suburban locations with the highest infiltration potential and lower opportunity costs - and a diversity of hybrid solutions. Substitution effects lead to discarding locations near urban parks, especially in centric locations. Finally, mixing NBS and grey infrastructures leads to a specialization of solutions by area and the potential to reach higher benefits at less opportunity costs
A growing soft robot with climbing plant–inspired adaptive behaviors for navigation in unstructured environments
No full textInternational audienceSelf-growing robots are an emerging solution in soft robotics for navigating, exploring, and colonizing unstructured environments. However, their ability to grow and move in heterogeneous three-dimensional (3D) spaces, comparable with real-world conditions, is still developing. We present an autonomous growing robot that draws inspiration from the behavioral adaptive strategies of climbing plants to navigate unstructured environments. The robot mimics climbing plants’ apical shoot to sense and coordinate additive adaptive growth via an embedded additive manufacturing mechanism and a sensorized tip. Growth orientation, comparable with tropisms in real plants, is dictated by external stimuli, including gravity, light, and shade. These are incorporated within a vector field method to implement the preferred adaptive behavior for a given environment and task, such as growth toward light and/or against gravity. We demonstrate the robot’s ability to navigate through growth in relation to voids, potential supports, and thoroughfares in otherwise complex habitats. Adaptive twining around vertical supports can provide an escape from mechanical stress due to self-support, reduce energy expenditure for construction costs, and develop an anchorage point to support further growth and crossing gaps. The robot adapts its material printing parameters to develop a light body and fast growth to twine on supports or a tougher body to enable self-support and cross gaps. These features, typical of climbing plants, highlight a potential for adaptive robots and their on-demand manufacturing. They are especially promising for applications in exploring, monitoring, and interacting with unstructured environments or in the autonomous construction of complex infrastructures
The links between wood traits and species demography change during tree development in a lowland tropical rainforest
No full textInternational audienceOne foundational assumption of trait-based ecology is that traits can predict species demography. However, the links between traits and demographic rates are, in general, not as strong as expected. These weak associations may be due to the use of traits that are distantly related to performance, and/or the lack of consideration of size-related variations in both traits and demographic rates. Here, we examined how wood traits were related to demographic rates in 19 tree species from a lowland forest in eastern Amazonia. We measured 11 wood traits (i.e. structural, anatomical and chemical traits) in sapling, juvenile and adult wood; and related them to growth and mortality rates (MR) at different ontogenetic stages. The links between wood traits and demographic rates changed during tree development. At the sapling stage, relative growth rates (RGR) were negatively related to wood specific gravity (WSG) and total parenchyma fractions, while MR decreased with radial parenchyma fractions, but increased with vessel lumen area (VA). Juvenile RGR were unrelated to wood traits, whereas juvenile MR were negatively related to WSG and axial parenchyma fractions. At the adult stage, RGR scaled with VA and wood potassium concentrations. Adult MR were not predicted by any trait. Overall, the strength of the trait-demography associations decreased at later ontogenetic stages. Our results indicate that the associations between traits and demographic rates can change as trees age. Also, wood chemical or anatomical traits may be better predictors of growth and MR than WSG. Our findings are important to expand our knowledge on tree life-history variations and community dynamics in tropical forests, by broadening our understanding on the links between wood traits and demography during tree development
Sorption of water and ethanol pure vapours and vapour mixtures by four hardwoods
No full textInternational audienceWater is a universal solvent and swelling agent that is widely used in wood industry in association with organic solvents and salts, whether for the fractionation of biomass and the production of bio-based synthons for the chemical industry, the application of sizing agents and painting for the paper industry or the incorporation of preservatives to enhance wood durability for the timber industry. The relevance of solvents and technical treatments used for wood-based products requires a proper identification of the specific role of each solvent on wood biopolymers to better understand and predict their influence on wood properties. In particular, wood impregnated with aqueous solutions of organic solvents has shown to give rise to greater swelling than that observed in pure water, described as “hyperswelling”. To understand this phenomenon, the first step is to examine the existing interactions between wood microstructure and the different solvents present in these mixtures. This study is an attempt to bring to light the sorption behaviour of four different hardwoods in water–ethanol vapour mixtures containing increasing molar fractions of ethanol from 0 to 100%. Contrasted sorption behaviour in pure solvents was observed according to wood species having different biochemical compositions. This behaviour highlights the different affinities of ethanol and water for the macromolecules present in the wood microstructure. With mixed solvents, peculiar effects were confirmed in sorption behaviour of woods with lower mixed solvent uptake at high partial pressures compared to pure solvents. It is also shown that part of the sorbed ethanol molecules remains chemisorbed in the wood structures at the end of the desorption process
Suivre les bidons jaunes à Toliara, ville du Sud-Ouest de Madagascar : Contribution exploratoire au développement d’une écologie globale des plastiques
No full textVersion "manuscrit auteur accepté".À paraître dans Natures Sciences Sociétés (2024, 32, 3) sous licence CC-BY.En attente de la préparation de copie avant publication.International audienceIn the city of Toliara in South-Western Madagascar, 20 L jerrycans in yellow plastic are ubiquitous. Intact or altered, they are used in a variety of ways, by a variety of actors, in a variety of contexts. Looking at these jerrycans through the lens of their biography contributes to the development of a global ecology of plastics, by shedding light on the upstream side of the proliferation in the marine environment of macro and micro plastic waste. In this paper, this approach is based on the social science method referred to as ‘follow the thing’, which consists in tracing the complex journey of a given product or object that otherwise receives little scientific, policy and media attention. Our starting point was the sale of empty yellow jerrycans in Ankilifaly, in the heart of Toliara. From there, we identified five main moments in the life of yellow jerrycans, each raising a key social issue: (1) jerrycans as containers for cooking oil, reflecting the market economy; (2) the sale of empty jerrycans as a small-scale urban trade; (3) jerrycans as water containers, but also an indicator of water insecurity and an adaptation tool; (4) altered jerrycans and their multiple reuses; (5) jerrycan fragments, between litter and potential recyclable materials. This exploratory work allows us to move beyond the mainstream scientific focus on marine microplastics, while showing the value of the ‘follow the thing’ method in meeting the challenge of a social science approach to plastics.Dans la ville de Toliara dans le Sud-Ouest de Madagascar, les bidons de 20 L en plastique jaune sont omniprésents. Intacts ou altérés, ils font l’objet d’usages variés, par divers acteurs, dans divers contextes. S’intéresser à ces bidons sous l’angle de leur biographie permet d’éclairer l’amont des proliférations de macro- et micro-déchets plastiques dans l’environnement marin. Cinq principaux moments de la vie d’un bidon jaune, soulevant chacun une problématique sociale principale, sont ici mis en lumière : (1) le bidon comme contenant d’huile alimentaire, reflet de l’économie de marché ; (2) la vente de bidons vides comme petit métier urbain ; (3) le bidon comme contenant d’eau, mais aussi indicateur de la précarité hydrique et outil d’adaptation ; (4) le bidon altéré, objet de multiples réutilisations ; (5) les fragments de bidon, entre déchet sauvage et potentielle matière à recycler
Convolutional neural network allows amylose content prediction in yam (<i>Dioscorea alata</i> L.) flour using near infrared spectroscopy
No full textInternational audienceBackground: Yam (Dioscorea alata L.) is the staple food of many populations in the intertropical zone, where it is grown. The lack of phenotyping methods for tuber quality has hindered the adoption of new genotypes from breeding programs. Recently, near-infrared spectroscopy (NIRS) has been used as a reliable tool to characterize the chemical composition of the yam tuber. However, it failed to predict the amylose content, although this trait is strongly involved in the quality of the product. Results: This study used NIRS to predict the amylose content from 186 yam flour samples. Two calibration methods were developed and validated on an independent dataset: partial least squares (PLS) and convolutional neural networks (CNN). To evaluate final model performances, the coefficient of determination (R 2), the root mean square error (RMSE), and the ratio of performance to deviation (RPD) were calculated using predictions on an independent validation dataset. The tested models showed contrasting performances (i.e., R 2 of 0.72 and 0.89, RMSE of 1.33 and 0.81, RPD of 2.13 and 3.49 respectively, for the PLS and the CNN model). Conclusion: According to the quality standard for NIRS model prediction used in food science, the PLS method proved unsuccessful (RPD < 3 and R 2 < 0.8) for predicting amylose content from yam flour but the CNN model proved to be reliable and efficient method. With the application of deep learning methods, this study established the proof of concept that amylose content, a key driver of yam textural quality and acceptance, can be predicted accurately using NIRS as a high throughput phenotyping method
Two new species of Rasnichneumon (Ichneumonidae: Novichneumoninae) from mid-Cretaceous Kachin amber
No full textInternational audienceWe report two new species of Novichneumoninae from mid-Cretaceous Kachin amber: Rasnichneumon klopfsteinae sp. nov. and Rasnichneumon gibbosus sp. nov. These new species increase the diversity of novichneumonine wasps documented from Kachin amber during the mid-Cretaceous. We emend the diagnosis of the genus Rasnichneumon to accommodate the morphology of the new species. Finally, we discuss the unique state of color preservation in the new specimens, uncommon morphological features of Rasnichneumon, , shape of the ovipositor of novichneumonines and its implications
Leaf firing symptoms and their genetic analysis in a grapevine diversity panel suddenly exposed to a record heatwave
No full textInternational audienceThis dataset comes from a panel of 279 grapevine (Vitis Vinifera) cultivars, that was designed to maximize genetic diversity and minimize relatedness among cultivated grapevine while capturing the main low structure in three genetic pools (Nicolas et al., 2016). The panel was studied in summer 2019 on 2-year-old potted plants cultivated outdoors in Montpellier, South France, with 20 plants per cultivar. For each cultivar, all 20 plants were grouped, with 10 plants facing South-West and 10 plants facing North-East. On June 28th a record heatwave occurred over a large art of Europe. After air temperature reached 45°C in our experimental vineyard, some cultivars were largely burnt while others showed no symptoms. The proportion and intensity of leaf firing were scored for all 279 cultivars of the diversity panel on July 2nd, three days after the heatwave. Scoring was based on a visual scale. One score for leaf firing proportion and one score for leaf firing intensity were attributed for the group of 10 plants of each cultivar in each orientation (South-West or North-East). Proportion of leaf firing was scored from 0 to 100% as the proportion of leaves at least partly burnt within the canopy. Intensity of leaf firing was scored as 0, 1, 2, 3, 4 or 5 to describe the extent of the firing within one representative fired leaf (0 when no symptoms, 1 when only leaf margins were affected, up to 5 when the whole leaf was affected). We further calculated the magnitude of symptoms at the canopy level as the product of proportion and intensity. Morphological traits were also studied on the panel. From mid-June to the end of July, we sampled 10 to 14 leaves for each cultivar in order to measure their area. Leaves were chosen as fully expanded and well-irradiated, generally between the tenth and fifteenth phytomers from the apex. They were flattened and cut if necessary to avoid overlap, and then immediately scanned using a flatbed scanner. Leaf area was then obtained through a segmentation procedure in Python. Leaf dry weight was measured after one week in a drying oven (60°C), and leaf mass per area (LMA) was calculated as the ratio between dry weight and area. For leaf area and LMA, the best linear unbiased predictors (BLUPs) of genetic values were estimated using mixed-models. For leaf firing proportion and intensity, each score already consisted in a single average observation for each cultivar and orientation. Along with genotypic data (197,885 SNPs issued from microarray and genotyping-by-sequencing (Flutre et al., 2022) and reduced to 82,868 SNPs after excluding i) SNPs that did not vary across the panel, ii) SNPs with a minor allelic frequency below 5% and iii) duplicated positions), this dataset was used to perform genome wide association studies (GWAS) to detect SNPs associated with leaf firing symptoms or morphological traits. Three GWAS methods were used (MM4LMM, MLMM and varbvs). The ultimate goal of this study was to investigate genomic regions associated to extreme heat tolerance and disclose high-priority candidate genes, and to assess whether these regions co-localized with associations for morphological traits. The associated publication is: Coupel-Ledru A, Westgeest AJ, Albasha R, Millan M, Pallas B, Doligez A, Flutre T, Segura V, This P, Torregrosa L, Simonneau T, Pantin F (2024) Clusters of grapevine genes for a burning world. New Phytologist. DOI: 10.1111/nph.19540
Les collectivités territoriales face aux risques d'inondation. De nouvelles réponses à inventer en contexte de changement climatique
No full textInternational audienceLes communes et les intercommunalités sont en première ligne pour prévenir les risques – tout particulièrement celui d’inondation, premier risque naturel en France – sur leur territoire. Mais le changement climatique questionne les mesures de prévention et leur efficacité. L’adaptation des territoires aux conséquences du changement climatique s’impose comme un registre d’action dont doivent se saisir les collectivités. Ce chapitre montre comment certains élus locaux prennent conscience, souvent au lendemain d’une catastrophe, de la nécessité d’adapter leur territoire au changement climatique et comment ils s’efforcent de repenser l’aménagement de leur territoire en mettant en œuvre des formes d’aménagement favorisant l’adaptation et la résilience de leurs territoires face aux risques d’inondation