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Assimilating Sentinel-2 data in a modified vegetation photosynthesis and respiration model (VPRM) to improve the simulation of croplands CO2 fluxes in Europe
No full textInternational audienceIn Europe, the heterogeneous features of crop systems with majority of small to medium sized agricultural holdings, and diversity of crop rotations, require high-resolution information to estimate cropland Net Ecosystem Exchange (NEE) and its two main components of Gross Ecosystem Exchange (GEE) and the Ecosystem Respiration (RECO). In this context, this paper presents an assimilation of high-resolution Sentinel-2 indices with eddy covariance measurements at selected European cropland flux sites in a new modified version of Vegetation Photosynthesis Respiration Model (VPRM). VRPM is a data-driven model simulating CO2 fluxes previously applied using satellite-derived vegetation indices from the Moderate Resolution Imaging Spectroradiometer (MODIS). This study proposes a modification of the VPRM by including an explicit soil moisture stress function to the GEE and changing the equation of RECO. It also compares the model results driven by S2 indices instead of MODIS. The parameters of the VPRM model are calibrated using eddy-covariance data. All possible parameters optimization scenarios include the use of the initial version vs. the proposed modified VPRM, S2, or MODIS vegetation indices, and finally the choice of calibrating a single set of parameters against observations from all crop types, a set of parameters per crop type, or one set of parameters per site. Then, we focus the analysis on the improvement of the model with distinct parameters for different crop types vs. parameters optimized without distinction of crop types. Our main findings are: (1) the superiority of S2 vegetation indices over MODIS for cropland CO2 fluxes simulations, leading to a root mean squared error (RMSE) for NEE of less than 3.5 μmolm2s-1 with S2 compared to 5 μmolm2s-1 with MODIS (2) better performances of the modified VPRM version leading to a significant improvement of RECO, and (3) better performances when the parameters are optimized per crop-type instead of for all crop types lumped together, with lower RMSE and Akaike information criterion (AIC), despite a larger number of parameters. Associated with the availability of crop-type land cover maps, the use of S2 data and crop-type modified VPRM parameterization presented in this study, provide a step forward for upscaling cropland carbon fluxes at European scale
RSM as a tool for optimizing the formulation of a sorghum-based salted biscuit that can be rotary-molded
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Multiscale modelling of hepatitis B virus at cell level of organization
No full textInternational audienceMultiscale modelling is a promising quantitative approach for studying infectious disease dynamics. This approach garners attention from both individuals who model diseases and those who plan for public health because it has great potential to contribute in expanding the understanding necessary for managing, reducing, and potentially exterminating infectious diseases. In this article, we developed a nested multiscale model of hepatitis B virus (HBV) that integrates the within-cell scale and the between-cell scale at cell level of organization of this disease system. The between-cell scale is linked to the within-cell scale by a once off inflow of initial viral infective inoculum dose from the between-cell scale to the within-cell scale through the process of infection; the within-cell scale is linked to the between-cell scale through the outflow of the virus from the within-cell scale to the between-cell scale through the process of viral shedding or excretion. The resulting multiple scales model is bidirectionally coupled in such a way that the within-cell scale and between-cell scale sub-models mutually affect each other, creating a reciprocal relationship. The computed reproductive number from the multiscale model confirms that the within-host scale and the between-host scale influence each other in a reciprocal manner. Numerical simulations are presented that also confirm the theoretical results and support the initial assumption that the within-cell scale and the between-cell scale influence each other in a reciprocal manner. This multiple scales modeling approach serves as a valuable tool for assessing the impact and success of health strategies aimed at controlling hepatitis B virus disease system
Travail animal et agentivité morale. Éducation et dressage des chiens
No full textInternational audienceCet article éclaire l’agentivité morale des animaux à partir du travail animal. À l’appui d’une ethnographie comparée du dressage des chiens de patrouille et de l’éducation des chiens d’aveugles, il montre comment les animaux s’investissent respectivement dans l’exercice de la violence et de la bienveillance, en portant une attention particulière au rôle du chenil. Dans le dressage des chiens policiers, le chenil est un instrument d’isolement et de domination qui enferme les animaux dans l’agressivité pour en faire des instruments de la force publique. Il se caractérise par une souffrance au travail des animaux, marquée par une pathologisation de leur rapport à l’agressivité, montrant ainsi que la violence ne va pas de soi. À l’inverse, dans l’éducation des chiens guides, le chenil est un espace ouvert contribuant à l’intelligence et l’attachement des animaux pour devenir des travailleurs du care
L’ alkè des chevaux de concours complet
No full textInternational audienceÀ partir des collectifs de travail humains-chevaux concourant à haut niveau dans la discipline du concours complet d’équitation, il s’agit de montrer en quoi les chevaux acquièrent une seconde nature par le travail. Pour cela, une enquête a été menée auprès de huit cavaliers de haut niveau. Dans un premier temps, des entretiens semi-directifs ont été tenus puis trois cavaliers ont été suivis lors des Championnats de France de concours complet et lors des Championnats du monde des jeunes chevaux de sept ans. Les résultats montrent toute la complexité et la richesse des relations de travail entre humains et chevaux. Il apparaît un rapport ambivalent, inégal, où l’humain s’attache à mettre en lumière les qualités physiques et mentales de l’athlète équin qui devient un individu extraordinaire
The world’s largest worm lizard - a new giant trogonophid (Squamata, Amphisbaenia) with extreme dental adaptations from the Eocene of Chambi, Tunisia
No full textInternational audienceWe here describe Terastiodontosaurus marcelosanchezi, a new amphisbaenian genus and species from the Eocene of Chambi, Tunisia. Using micro-computed tomography (μCT), we document the peculiar anatomy of the new taxon, which is characterized by extreme dental morphology, including one massive tooth on the maxilla and dentary, flat cheek teeth, and an array of other diagnostic features that readily differentiate it from all other amphisbaenians. We also redescribe the oldest named African amphisbaenian, Todrasaurus gheerbranti, from the late Paleocene of Morocco, using μCT. Phylogenetic analysis recovers Terastiodontosaurus and Todrasaurus as sister-taxa and provides strong support for a sister-group relationship of those two large-toothed amphisbaenians with extant Trogonophis. Accordingly, Todrasaurus shows that the divergence of crown Trogonophidae occurred much earlier than currently thought. Our survey of μCT scans reveals that Terastiodontosaurus, Todrasaurus, and Trogonophis are characterized by a great enamel thickness on their teeth, a feature that is absent in other examined amphisbaenians. Size estimates show that Terastiodontosaurus was the largest known amphisbaenian to have ever lived, with an estimated skull length > 5 cm. Based on novel muscle data of Trogonophis, we estimate very high bite forces for Terastiodontosaurus, which would allow it to crush a wide variety of snails
High‐resolution mapping of available water content in Senegal using iSDA Africa dataset and USDA Rosetta3 model
No full textInternational audienceThis data article presents a high‐resolution map of available water content (AWC) for Senegal, derived from the iSDA Africa dataset and the USDA Rosetta3 model, as well as the method used for its production. The map covers the entire country at a resolution of 30 m and provides a valuable resource for hydrological studies and spatialized crop model simulations in the region where water is a limiting factor for crop production. The dataset is based on existing soil properties data and leverages pedotransfer functions (PTFs) to estimate water retention capabilities from soil properties. This AWC map derived from datasets with enhanced accuracy offers a more precise estimate of soil water retention capacity, which can be instrumental in informing water and agricultural management, policy decisions and investments. The dataset, including intermediate variables, is available in geotiff format at Cirad Dataverse under the DOI 10.18167/DVN1/SGNSII and complies with FAIR data principles, allowing its broad reuse. The code used to produce this dataset is also made available under the DOI 10.5281/zenodo.10078399 , so that AWC maps can be produced for any territory covered by the iSDA Africa product
Resumption of the planting of grapevine varieties in France, referred to as "disease-resistant"
No full textInternational audienceThis article investigates the beginning of the adoption of a new generation of “resistant” grapevine varieties (RVs) in France, in a European context in which varietal innovation has become more and more dynamic over the last thirty years.Today, there is a growing interest in this plant material, because it constitutes a lever for adaptation to the combined impacts of climate change and fungal diseases in vineyards. Based on data from the French digital vineyard register (CVI: “casier viticole informatisé”), this paper provides RV maps of leading regions, as well as less involved ones, which show the implantation of these varieties
Mycena citricolor isolates from diverse hosts in Costa Rica: Colony aspect, growth dynamics, reproduction in vitro and aggressiveness on Coffea arabica
No full textInternational audienceAbstract The basidiomycete fungus Mycena citricolor hosts on about 80 plant families. The asexual morph causes the disease known as American leaf spot of coffee ( Coffea arabica ). We isolated and characterized 15 isolates of M. citricolor collected from coffee plants, shade trees and weeds. Cultures on potato‐dextrose‐agar + yeast extract (PDAY) medium were kept for a week in complete darkness. The cultures were then exposed to light for 7 weeks and co‐cultivated with coffee foliar discs, to stimulate the production of gemmifers. We evaluated the speed of growth, appearance, colour of the mycelium and gemmifers production capacity. All isolates conformed to the typical cultural characteristics of M. citricolor , with beige/white thin and slightly aerial mycelium. The whitest isolate was from Persea americana , which had the slowest growth rate in vitro (6.4 mm/day), while the isolate from weed Kalanchoe pinnata was the fastest, with a speed of 9 mm/day. The most gemmifer‐producing isolates were those isolated from the coffee cultivar Catimor‐Costa Rica 95, Citharexylum donnell‐smithii and Cissus verticillata , with over 200 gemmifers per Petri dish. Isolates from Erythrina and Ipomoea nil produced <50 gemmifers on average. The Composite Aggressiveness Index (CAI) was determined on 2‐year‐old detached coffee branches of the Caturra variety foliage. The least aggressive isolate was from Erythrina poeppigiana (CAI = 0) and the most aggressive was from Kalanchoe pinnata (CAI = 18.87). The isolate from the coffee cultivar Catimor‐Costa Rica 95 was more aggressive than that from the cultivar Caturra (CAI = 9.94 vs. CAI = 3.66). Moreover, successful infection occurred only when the apex of gemmae made direct contact with the coffee leaf when using the inoculum derived from C. verticillata and Anredera cordifolia . These results show the variability in the population of the pathogen. This is the first study that characterizes the growth, morphology, reproduction and aggressiveness of M. citricolor obtained from hosts other than coffee. In addition, it is the first to report the use of coffee foliar discs to induce gemmifer production in vitro and to assess and quantify the effect of gemma position when inoculating coffee leaves
Advancing sustainable futures through education: A Montpellier case study on student-led advocacy for transdisciplinary approaches
No full textInternational audienceThis paper examines the transformative potential of integrating transdisciplinarity and systems thinking into educational practices, anchored in a participatory initiative by the Montpellier Advanced Knowledge Institute on Transitions (MAK'IT). The study centres on engaging master’s and doctoral students in co-creating educational proposals, underscoring the importance of a student-centred approach to tackle the diverse challenges of the 21st century. A preliminary brainstorming session allowed students to express their motivations, identify key themes, and lay the groundwork for further development. This culminated in a public conference where students presented their transformative education proposals. This conference facilitated interactions between students, a panel of experts spanning education, research, policy domains, and a broader audience, fostering critical dialogue. Key findings from this conference underscore the necessity of allocating resources, dismantling knowledge silos, addressing student inequalities, and enhancing educator preparedness. The study highlights the significance of multi-stakeholder dialogues in co-constructing transformative educational frameworks and suggests that educational institutions have a pivotal role in bridging the gap between science, policy, and society. Despite the promise, several challenges to curriculum revision emerge, including the need for immersive learning environments that demand adequate resources. The structure of tertiary institutions, often segregated into distinct faculties and departments, presents another barrier to fostering transdisciplinarity. Additionally, administrative constraints, particularly for international students, add to these challenges and call for nuanced strategies in advancing transformative education