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Speleogenetic reconstitution of a karst combining underground and surface geomorphology -implication for hydrology (Verneau, French Jura)
No full textInternational audienceThe aim of our work is to propose a speleogenetic reconstitution of a karst network, combining two complementary morphological approaches from underground and surface data, in order to relate the speleogenesis model with the hydrogeological one. The study site is the underground karst network of Verneau (French Jura), which has the particularity of being almost completely penetrable and topographically recognized. The hydrosystem is characterized by 5 sinkholes draining the marly outcrops of the recharge area. First, the geometry of the underground network (orientation and organization of conduits) is characterized using the open-source software Karstnet. Second, a chronology of the network development is assessed by calculating the erosion time required to shape the surface forms of the marly sinkholes watersheds, identifying the erosion levels and estimating the eroded volumes using DTM data. Finally, the spatial variability of the water level dynamics along the conduit network is characterized using a comparative approach of the hydrological response recorded at 6 stations.The quantitative approach of the geometrical characterization of the underground network allows us to divide the Verneau into two downstream and upstream compartments with significantly different properties on conduit orientation and network organization. On the surface, we traced the erosion levels of each losing stream, then quantified the erosion time required to form the surface shapes. The information gathered is convergent, enabling us to propose a coherent model of speleogenesis of the Verneau underground network through the phases in which the surface network was captured during the Quaternary. The study of water level variations at different sites along the network showed that there is a spatial variability of the hydrological response, consistent with the morphological downstream/upstream compartmentalization identified in the speleogenesis model. Moreover, the comparative analysis enables us to date the compartments relatively well, to deduce the structural history of the Verneau network, and to relate it to its current hydrology. This work represents an initial approach to the development and structuration of karst aquifers in the Jura Mountains
Variations in Chlorella lipid content in commercial and in-lab produced biomass ☆
No full textInternational audienceMicroalgae appear as a sustainable source of biomass with relevant nutritional qualities. Still,regulatory restrictions currently limit the use of eukaryotic microalgae for human consumption to a short list of species dominated by Chlorella spp. Chlorella biomass contains valuable proteins but also interesting lipids, including polyunsaturated fatty acids (PUFA) v3 and v6. The amount of PUFA and the v6/v3 ratio vary significantly depending on the species and cultivation trophic mode. While the lipid profiles of in-lab produced Chlorella has been widely studied, the variability of lipid content in commercial biomasses is barely described. Here, lipid classes and fatty acid profiles of six commercial biomasses of Chlorella spp. as well as those of lab-produced C. sorokiniana grown in photo-autotrophy and in four mixotrophy conditions were characterized. Results showed significant lipid composition variations between the biomasses, such as the triacylglycerols/glycolipids and v6/v3 contents. The v6/v3 ratios were lower inphoto-autotrophic mode (2.5) while they ranged between 1.3 and 8.9 in commercial biomasses. The freefatty acids level was also variable (1.4% to 17.9% of total lipids). As a consequence, Chlorella lipidcontent and quality differed significantly, impacting the potential nutritional benefits of the consumptionof commercial biomass. Processing and post-processing conditions should therefore be carefullycontrolled to optimize lipid profilesLes microalgues sont une ressource durable de biomasse aux qualités nutritionnelles précieuses.Toutefois, des contraintes réglementaires limitent leur consommation humaine, privilégiant les espèces deChlorella. Les Chlorella contiennent des protéines mais aussi des lipides d’intérêt, notamment des acidesgras polyinsaturés (AGPI) v3 et v6 dont les teneurs varient significativement selon l’espèce et le modetrophique de culture. Bien que les profils lipidiques de Chlorella aient été largement étudiés en laboratoire,ceux des biomasses commerciales sont peu décrits. Les classes de lipides et profils d’acides gras de sixbiomasses commerciales de Chlorella spp. et d’une souche de C. sorokiniana produite en laboratoire, enphoto-autotrophie et mixotrophies, ont été caractérisés dans cette étude. Des compositions lipidiquesdifférentes ont été obtenues, notamment pour les ratios triacylglycérols/glycolipides et v6/v3. Enlaboratoire la biomasse cultivée en photo-autotrophie présentait le plus bas ratio v6/v3 (2.5), tandis qu’ilfluctuait entre 1.3 et 8.9 dans les commerciales. Leur taux en acides gras libres variait également de manière importante (1.4 à 17.9 % des lipides totaux). Finalement, la teneur et la qualité lipidique des Chlorelles différaient significativement, impactant leurs potentiels bénéfices nutritionnels. Un contrôle des conditions de production et post-traitement est donc nécessaire pour optimiser les profiles en lipides
Combined sensory, volatilome and transcriptome analyses identify a limonene terpene synthase as a major contributor to the characteristic aroma of a Coffea arabica L. specialty coffee
No full textInternational audienceBackground The fruity aromatic bouquet of coffee has attracted recent interest to differentiate high value market produce as specialty coffee. Although the volatile compounds present in green and roasted coffee beans have been extensively described, no study has yet linked varietal molecular differences to the greater abundance of specific substances and support the aroma specificity of specialty coffees. Results This study compared four Arabica genotypes including one, Geisha Especial, suggested to generate specialty coffee. Formal sensory evaluations of coffee beverages stressed the importance of coffee genotype in aroma perception and that Geisha Especial-made coffee stood out by having fine fruity, and floral, aromas and a more balanced acidity. Comparative SPME-GC-MS analyses of green and roasted bean volatile compounds indicated that those of Geisha Especial differed by having greater amounts of limonene and 3-methylbutanoic acid in agreement with the coffee cup aroma perception. A search for gene ontology differences of ripening beans transcriptomes of the four varieties revealed that they differed by metabolic processes linked to terpene biosynthesis due to the greater gene expression of prenyl-pyrophosphate biosynthetic genes and terpene synthases. Only one terpene synthase (CaTPS10-like) had an expression pattern that paralleled limonene loss during the final stage of berry ripening and limonene content in the studied four varieties beans. Its functional expression in tobacco leaves confirmed its functioning as a limonene synthase. Conclusions Taken together, these data indicate that coffee variety genotypic specificities may influence ripe berry chemotype and final coffee aroma unicity. For the specialty coffee variety Geisha Especial, greater expression of terpene biosynthetic genes including CaTPS10-like, a limonene synthase, resulted in the greater abundance of limonene in green beans, roasted beans and a unique citrus note of the coffee drink
Un référentiel actualisé de l’aide alimentaire pour concevoir des dons équilibrés
No full textEn intégrant l’ensemble des dernières recommandations d’apports en nutriments de l’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (ANSES), ainsi que les recommandations de consommation alimentaire du PNNS 4, ce travail met à jour le « référentiel de l’aide alimentaire », c’est-à-dire la répartition idéale des catégories d’aliments dans les dons.Cette répartition a été obtenue par programmation linéaire à partir des données de consommation alimentaire des adultes de l’étude INCA 3.Le référentiel fournit aux associations les moyens d’évaluer l’équilibre nutritionnel de leurs stocks et de leurs dons et facilite l’identification de voies d’amélioration. Un outil permettant de traduire le référentiel en dons alimentaires a également été développé et des exemples de paniers ainsi générés sont présentés
L’intégration agriculture-élevage pour former à l’agroécologie
No full textInternational audienceFormer à l’agroécologie représente un défi de taille : d’une part, l’agroécologie recouvre une multitude d’éléments renvoyant à des disciplines et à des échelles différentes (Wezel et al., 2020) ; d’autre part, ses principes se déclinent de manière variée selon les contextes locaux. Pour aborder la transition agroécologiqueen formation, la pédagogie par projet est souvent utilisée, en complément de cours et travaux dirigés. Au sein de ces projets à vocation pédagogique, l’intégration agriculture-élevage (IAE) apparait comme un moyen privilégié pour faire manipuler aux étudiants les principes de l’agroécologie. Cette étude propose et analyse un cadre méthodologique commun pour mobiliser l’IAE dans un contexte pédagogique d’étude de la transition agroécologiqu
From problem to progress: Rodent management in agricultural settings of sub-Saharan Africa and calling for an urban perspective
No full textInternational audienceHighlights: • In Africa, agricultural intensification and urbanization are major changes. • These changes increase the risk of rodent proliferation in rural and urban habitats. • Conventional rodent control relies on reactive, inappropriate use of rodenticides. • Ecologically-Based Rodent Management has been poorly tested in sub-Saharan Africa. • This method can be a realistic, sustainable and environment-friendly alternative.Abstract: In sub-Saharan Africa, agricultural intensification and urbanization have increased the risk of proliferation of rodents in rural and urban habitats. Management of rodent populations is a challenge in terms of food security and public health. However, conventional efforts to manage rodents are currently reactive and based on the inadequate use of synthetic chemical rodenticides, including first- and second-generation anticoagulants and acute rodenticides. This approach carries substantial environmental and health risks and has yielded limited success in terms of reduction of rodent populations sustainably. In this paper, which is the second part of a diptych, we advocate for a shift towards more sustainable and environmentally friendly approaches, such as Ecologically-Based Rodent Management (EBRM), as a realistic alternative to synthetic rodenticides. This method is based on a good knowledge of habitat use, species diversity and population dynamics of major rodent pests, and involves community-based interventions aimed at reducing rodent abundance to economically and hygienically acceptable levels in the long term. We present for the first time a comprehensive compilation of published and unpublished information derived from observational field studies conducted in Ethiopia, Niger, Nigeria, Benin, Mali, Mauritania and Senegal with the aim to provide an overview of EBRM case studies in these countries of sub-Saharan Africa. This paper intends to serve as a catalyst for change, encouraging the transformation of rodent management practices towards sustainable methods. We aim at stimulating further research and interventions that promote EBRM in Africa, ultimately fostering more environmentally conscious and effective solutions.Graphical abstract: https://ars.els-cdn.com/content/image/1-s2.0-S0261219424001017-ga1.jp
Shade tree trait diversity and functions in agroforestry systems: A review of which traits matter
No full textInternational audienceShade trees in agroforestry systems confer ecosystem services, such as enhanced soil fertility from diverse litter inputs, microclimate regulation via shade, and disease mitigation through trophic and abiotic interactions. With this thriving role of agroforestry in sustainable agriculture, particularly for tree crops, systematic and reliable methods to select shade trees for specific agroecosystem outcomes are crucial. Plant functional traits offer a framework to describe, select and manage shade trees. Over the last decade, shade tree leaf functional traits and whole plant traits have been assessed in agroforestry systems. Yet, we lack amalgamated information on (i) what we know about shade tree trait relationships with functions to achieve desired agroecosystem outcomes, (ii) how decades of shade tree selection by farmers impacts agroforests inter‐ and intraspecific trait diversity, and (iii) which shade tree traits should be considered for achieving farmer priorities. We consolidate literature on Coffea arabica (coffee) and Theobroma cacao (cocoa) agroforestry systems to summarize the role of shade tree functional traits in three key ecosystem functions: soil fertility, microclimate modification and crop productivity. We compile global and regional datasets on tree functional trait diversity to show the functional space of agroforestry tree species compared with the overall functional space observed in plants. Despite, or maybe because of, high shade tree diversity, shade tree trait characterization remains coarse and commonly measured at the community scale in the literature. Based on published trait data, we show that farmers adjust the functional composition of shade trees to increase the recycling of soil nutrients (high leaf nitrogen), the production of wood (skewing towards lower wood densities) and the production of fruits (tendency towards high seed size). Common shade trees in coffee and cocoa systems fall in the mid‐range of leaf acquisitive to conservative strategies, providing evidence that expanding shade tree portfolios can improve, or even accelerate, functions. Synthesis and applications : Based on the agroforestry literature and on trait‐environment relationships, we propose a matrix of shade tree traits that influence desirable agroecosystem outcomes for farmers, which can guide fine‐scale coordination of trait expression and agroforestry functions
LiDAR-based reference aboveground biomass maps for tropical forests of South Asia and Central Africa
No full textInternational audienceAccurate mapping and monitoring of tropical forests aboveground biomass (AGB) is crucial to design effective carbon emission reduction strategies and improving our understanding of Earth’s carbon cycle. However, existing large-scale maps of tropical forest AGB generated through combinations of Earth Observation (EO) and forest inventory data show markedly divergent estimates, even after accounting for reported uncertainties. To address this, a network of high-quality reference data is needed to calibrate and validate mapping algorithms. This study aims to generate reference AGB datasets using field inventory plots and airborne LiDAR data for eight sites in Central Africa and five sites in South Asia, two regions largely underrepresented in global reference AGB datasets. The study provides access to these reference AGB maps, including uncertainty maps, at 100 m and 40 m spatial resolutions covering a total LiDAR footprint of 1,11,650 ha [ranging from 150 to 40,000 ha at site level]. These maps serve as calibration/validation datasets to improve the accuracy and reliability of AGB mapping for current and upcoming EO missions (viz., GEDI, BIOMASS, and NISAR)
The impact of excluding adverse neonatal outcomes on the creation of gestational weight gain charts among women from low- and middle-income countries with normal and overweight BMI
No full textThe authors are members of the GWG Pooling Project ConsortiumInternational audienceBackgroundExisting gestational weight gain (GWG) charts vary considerably in their choice of exclusion/inclusion criteria, and it is unclear to what extent these criteria create differences in the charts’ percentile values. We aimed to establish the impact of including/excluding pregnancies with adverse neonatal outcomes when constructing GWG charts.MethodsThis is an individual participant data analysis from 31 studies from low- and middle-income countries. We created a dataset that included all participants and a dataset restricted to those with no adverse neonatal outcomes: preterm < 37 weeks, small or large for gestational age – SGA or LGA, low birth weight < 2,500 g, or macrosomia > 4,000 g. Quantile regression models were used to create GWG curves from 9 to 40 weeks, stratified by pre-pregnancy BMI, in each dataset.ResultsThe dataset without the exclusion criteria applied included 14,685 individuals with normal weight and 4,831 with overweight. After removing adverse neonatal outcomes, 10,479 individuals with normal and 3,466 individuals with overweight remained. GWG distributions at 13, 27, and 40 weeks were virtually identical between the datasets with and without the exclusion criteria, except at 40 weeks for normal weight and 27 weeks for overweight. For the 10th and 90th percentiles, the differences between the estimated GWG were larger for overweight (approximately 1.5 kg) compared to normal weight (< 1 kg). Removal of adverse neonatal outcomes had minimal impact on GWG trajectories of normal weight. For overweight, the percentiles estimated in the dataset without the criteria were slightly higher than those in the dataset with the criteria applied. Nevertheless, differences were < 1 kg and virtually nonexistent at the end of pregnancy.ConclusionsRemoving pregnancies with adverse neonatal outcomes had little or no influence on the GWG trajectories of individuals with normal and overweight