HAL Portal AgroParisTech
Not a member yet
73916 research outputs found
Sort by
Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique N°84
No full textINRAE, réseau ECOTOX → A paraîtreBulletin de veill
On the problem of minimizing the epidemic final size for SIR model by social distancing
No full textInternational audienceWe revisit the problem of minimizing the epidemic final size in the SIR model through social distancing of bounded intensity. In the existing literature, this problem has been considered imposing a priori interval structure on the time period when interventions are enforced. We show that when considering the more general class of controls with an L1 constraint on the confinement effort that reduces the infection rate, the support of the optimal control is still a single time interval. This shows that, for this problem, there is no benefit in splitting interventions on several disjoint time periods. However, if the infection rate is known beforehand to change with time once from one value to another one, then we show that the optimal solution could consist in splitting the interventions in at most two disjoint time periods
Datasets of 16S rRNA gene amplicon sequences, metabolites, and soluble immune components in bronchoalveolar lavage samples from severe asthmatic and age-matched control children
No full textInternational audienceSevere asthma (SA) is a heterogeneous condition characterized by multiple phenotypes, each characterized by different endotypes. Understanding the mechanisms occurring in the lungs of children with SA can help in understanding pathogenesis and in providing the most effective therapeutic strategies. This article describes microbiota, metabolites, and soluble immune components assessed in bronchoalveolar lavage (BAL) fluids from children with severe asthma (n = 20) and age-matched disease controls (n = 10). The article includes: (i) the protocol used to process BAL samples for 16S rRNA gene amplicon sequencing, metabolomic profiling and immune components assays; (ii) the bioinformatics steps applied to 16S rRNA and metabolomics dataset; (iii) an overview of the raw 16S rRNA gene amplicon sequencing data, presented as ASV and affiliation tables, raw data from untargeted metabolomics and the abundances of each of the eighty eight metabolites annotated with the highest confidence level, and concentrations of seventy three cytokines and of total IgG, IgA and IgE. Each dataset is available in the INRAE data repository (https://entrepot.recherche.data.gouv.fr/dataverse/inrae) with respective DOI: MICROBIOTA: 10.57745/LL3TFW, METABOLITES: 10.57745/1L8VRI, IMMUNE COMPONENTS: 10.57745/JOOGRQThese datasets provide valuable resources for further investigating the molecular mechanisms underlying severe asthma in children and its trajectories. They also offer the potential to identify a local signature of severe asthma through complementary multi-omics analyses and to discover local biomarkers associated with asthma endotypes. Datasets can also be reused to compare with other cohorts (children or adults) or to serve as reference datasets for other pulmonary diseases
Tea, coffee, and cocoa delay milk gastric coagulation in a biomimetic in vitro system (NERDT™) by hindering both acid- and pepsin-induced milk gelation
No full textInternational audienceThis study investigated the effect of mixing whole milk with hot water extract of cocoa, coffee, or tea on milk intragastric coagulation during dynamic in vitro digestion. Milk diluted with water in the same proportion (70:30 v/v) was used as the control. The effect of adding cocoa, coffee, or tea extracts on acid-and pepsin-induced milk coagulation was first studied using a rheometer. The control exhibited a significantly shorter (P < 0.0001) gelation time in acidinduced coagulation than the milk mixtures containing extracts. The delaying effect of extracts on pepsin-induced coagulation was even more pronounced with coffee, causing a marked delay in gelation time, while tea and cocoa completely prevented gel formation under our experimental conditions. The milk mixtures, preheated to 60 °C, were then studied during simulated gastric digestion using the NEar Real Digestive Tract (NERDT TM ) dynamic in vitro digestion system. Samples collected at the stomach exit at different time points were investigated for pH, dry matter and microstructure. During gastric digestion of the control, protein coagulation occurred between 5 to 18 min (pH 6.3 ± 0.01 and 5.7 ± 0.28, respectively), whereas in the presence of cocoa, coffee, or tea, milk coagulation was observed between 18 to 27 min (pH 5.6 ± 0.07 and 4.84 ± 0.22 respectively). Confocal micrographs revealed larger protein aggregates in samples containing extracts, with entrapped milk fat clearly visible. The observed effects are likely due to the high polyphenol content of the extracts, which are known to interact with milk proteins. Our findings therefore suggest that protein-polyphenol interactions delay casein coagulation in the stomach and may alter gastric emptying and subsequent nutrient absorption along the small intestine
Détermination des coefficients d’élasticité et de dilatation thermique du monocristal du Ti et du Co purs à travers des essais in situ en diffraction des rayons X couplés à un modèle de transition d’échelles
No full textInternational audienc
A Hybrid LiDAR–PROSAIL Approach for LAI Estimation in Vineyards
No full textInternational audienceLeaf Area Index (LAI) is a key indicator of canopy development and productivity in sustainable viticulture. However, accurately estimating LAI in vineyards remains challenging due to complex canopy architectures, which often lead radiative transfer models (RTMs), such as PROSAIL, to underestimate LAI. This study proposes a novel hybrid approach tailored to vertically trained vineyards that uses a PROSAIL-based spectral LAI baseline with LiDAR-derived structural information through a data-driven correction strategy. The study was conducted during the 2023 season in a Mediterranean vineyard comprising three grapevine varieties. A structurally weighted index (LLI_w) was derived using multiple linear regression to assign global, phenology- and variety-specific weights accounting for the relative importance of structural parameters across growth stages. The PROSAIL-derived LAI and LLI_w were subsequently integrated using Support Vector Machine regression. The hybrid model showed strong agreement with ground-measured LAI (R² = 0.88) and clearly outperformed PROSAIL alone (R² = 0.42). The hybrid model captured spatio-temporal and varietal differences in canopy development, correcting seasonal underestimations and revealing structural dynamics not detected by spectral models alone. By integrating spectral and structural data, this hybrid approach provides physiologically informed, temporally consistent LAI estimates, supporting adaptive, variety-specific vineyard monitoring
« Sinners », chronique musicale et horrifique de l’Amérique raciste
No full textThe Conversation Franc
Data from long-term experiments in temperate croplands to evaluate soil organic carbon models
No full textInternational audienceSoil organic carbon (SOC) models need independent evaluation against field measurements, but those latter are rarely publicly available and harmonized. In this study, we collected and shared data from 167 agronomic treatments in 34 agronomic long-term experiments (LTEs) located in temperate croplands, allowing the evaluation of several soil organic C models such as RothC, Century, AMG, MIMICS, ICBM, Millenial, and CTOOL. The dataset includes climate data, soil properties, C inputs from crops (n = 4588 records) and organic amendments, irrigation data, monthly soil cover, as well as SOC stock measurements in the topsoil layer (n = 1328 records). Climate, soil moisture, and soil temperature data were extracted from daily climate databases. Carbon inputs from crops were calculated from observed yields and harvest index, with some harvest index values estimated, combined with crop allometric coefficients from the literature. Descriptions of LTE, agronomic treatments, methodological metadata, and a part of the code, accompanies the dataset. The dataset can be reused to evaluate single SOC models, or to evaluate an ensemble of models
Governing by promises. Water scarcity and rural hegemony in Morocco
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616979/)International audienceOver the last decade, an important field of inquiry has emerged around the notion of promissory legitimation. It focuses less on the fulfillment of collective promises than on their production and reception. This paper aims, first, to foreground its relevance for – critical- policy studies, by highlighting the decisive role that promises can play in the (re)production of hegemony. Second, and more specifically, it seeks to identify some practices of promise adjustment: the everyday strategies by which governing actors adapt, modify and re-assert their promises when their credibility is under stress, in order to reproduce the hegemony of the same groups in society. I explore these practices in the case of an irrigation megaproject in Morocco, where a developmentalist promise is proving insufficient to defuse tensions surrounding future water access. I show that a key adjustment mechanism is to add new promises on top of the first one – in this case, a clientelist promise and a laissez-faire promise. The coexistence of different promises, however, displays the same chronic contradictions as policy in general, with the same attendant limitations in the hegemony it attempts to uphold
Participatory modelling for agroecological transitions: engaging stakeholders in transformative pathways
No full textInternational audienceCONTEXT. The worldwide use of synthetic pesticides has been rising for decades. Agroecology offers a promising alternative, but its adoption requires support from public policy and multi-scale institutional and social levers. Recent policy approaches integrate levers promoting collective and territorial collaboration, recognizing the local scale as crucial for agroecological transitions. These levers involve mobilizing territorial stakeholders and implementing context-specific levers.OBJECTIVE. Our objective is to better understand territorial levers that support agroecological transformation and associated practice change dynamics. We engaged with stakeholders using a generic territorial socio-ecological model to identify local levers and potential agroecological transition pathways.METHODS. In the Barrois region (Eastern France), a participatory modelling initiative involved stakeholders from a farming territory aiming to reduce pesticide use. Three participatory workshops were organized to: (1) identify context-relevant levers; (2) calibrate the model based on the territory's current state; and (3) explore agricultural trajectories and supporting levers.RESULTS AND CONCLUSIONS. The use of the model highlights the dynamic and multi-factor nature of transitions. The workshops fostered rich dialogue and proposals, playing a central role in co-construction. Participants collectively identified levers such as awareness-raising, training initiatives, new stakeholder networks, and evolving advisory services. However, these levers vary depending on farmers' sensitivities and production types. Discussions emphasized the importance of involving not only farmers but also consumers and supply chains to drive change.SIGNIFICANCE. This participatory approach produced a more realistic model and created learning opportunities for all participants (researchers and agricultural stakeholders), despite challenges like communicating complex theoretical concepts and vocabulary