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Do neonate lambs react to a ‘predator’ scent before any predation experience?
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Suivi du statut azoté d'une céréale en cultures associées par segmentation sémantique d'images visibles
No full textcommunication orale, résumé et 1er prix de la meilleur présentationNational audienceL'objectif de cette recherche est de développer une approche innovante combinant des technologiesnumériques avec des capteurs low-cost basés sur l'imagerie visible pour suivre le statut azoté descultures de céréale, dans les associations céréales-légumineuses. En s'appuyant sur les techniques deMachine Learning et d'intelligence artificielle (IA), et notamment sur la segmentation sémantique avecle modèle DeepLabV3+, cette méthode vise à offrir une alternative aux outils traditionnels tels que lespinces ou les chlorophyllomètres (SPAD, N-Tester), qui sont coûteux en temps et en main-d'œuvre etqui nécessitent un contact direct avec les feuilles.Dans ce cadre, l'algorithme DeepLabV3+ basé sur l'architecture ResNet50 a été évalué pour lasegmentation sémantique de culture triticale en association avec un peuplement de féverole.L’expérimentation a été conduite sur des micro-parcelles de l'unité expérimentale d’Epoisses del'INRAE composées d’une culture de triticale pure sans azote (Témoin) et sur-fertilisée (Référence),d’une association de cultures, « triticale féverole », semée en rang ou en mélange. Le suivi azotérepose sur une base de données de 948 images RGB, acquises à l'aide de smartphones en 2023 et 2024.L'annotation semi-automatique de ces images, facilitée par des modèles IA comme Yolo v5 et SAM,vise à optimiser le processus d'identification des cultures. Puis un indicateur agronomique, leNormalized Dark Green Color Index (nDGCI), a été développé pour évaluer l'état azoté de la culture.Ce nouvel indicateur permet de réduire l'influence des variations de luminosité, de s’affranchir desréglages smartphones et des conditions environnementales sur les mesures. Les résultats concernantl'état azoté sont conformes à la littérature : l'état azoté est plus faible pour le triticale sans azote parrapport à celui en association. Cette étude démontre ainsi le potentiel de l'imagerie visible associée àl'apprentissage profond pour offrir un suivi plus rapide et moins contraignant du statut azoté,favorisant ainsi le déploiement de cette technique à l'échelle d'une parcelle grâce à l'utilisation dedrone low-cost
Quels systèmes de culture pour réguler l'orobanche rameuse via les adventices ?
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Différents processus de régulation. Les mécanismes de régulation biologique des adventices
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Map and Statistical Model to Explore Spatial Heterogeneity
No full textInternational audienceThis chapter shows how cartographic expression and statistical modeling of geographical data can be combined and complement each other to describe, explore and explain the spatial heterogeneity observed, in this case, in the real estate market in a French departement . It details the construction of the data, starting with the land value requests files downloadable from the data.gouv.fr website. The chapter proposes a set of statistical and cartographic analyses of the data aggregated at the municipal level, enabling us to appreciate the spatial variability of the main variables in the database. It presents a hedonic model of house prices and shows how, in addition to the usual diagnostics of econometric regressions, maps of residuals, that is, the differences between observed values and the values estimated by the model, help to specify the model by informing the search for and choice of the model's explanatory variables
Ultra-high irradiance (UHI) blue light treatment: A promising method for inactivation of the wine spoilage yeast Brettanomyces bruxellensis
No full textInternational audienceUltra-high irradiance (UHI) blue light treatment is effective within minutes for inactivating both planktonic and sporicidal forms of numerous microorganisms. This treatment could represent a cost-effective and rapid process for microbial inactivation in a wide range of applications. Our study examined the effects of UHI blue light on planktonic and biofilm forms of Brettanomyces bruxellensis, one of the main spoilage microorganisms in red wines. Treatments of 1–5 min (22.2–111 J/cm2) were applied to planktonic cells, and 1–10 min (22.2–222 J/cm2) to biofilms. After treatments, we analyzed yeast cultivability and viability (esterase activity) using flow cytometry. The results showed that UHI blue light can inactivate both planktonic and biofilm forms of B. bruxellensis on wood or stainless steel. Treatments under 10 min led to a loss of cultivability with a lesser impact on viability, while a 10-min treatment caused complete loss of viability in all biofilms studied. Thus, UHI blue light treatment appears particularly promising for eliminating Brettanomyces biofilms on surfaces in the wine industry
What social representations do French consumers have of sustainable diets? Segmentation by level of education
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Do sheep (<i>Ovis aries</i>) discriminate human emotional odors?
No full textCorresponding author: [email protected] audienceWhile sheep can detect and discriminate human emotions through visual and vocal cues, their reaction to human body odors remains unknown. The present study aimed to determine whether sheep ( Ovis aries ) can detect human odors, olfactorily discriminate stressed from non-stressed individuals, and behave accordingly based on the emotional valence of the odors. Axillary secretions from 34 students were collected following an oral examination (stress odor) or a regular class (non-stress odor). Fourteen female and 15 male lambs were then exposed to these odors through a habituation-dishabituation procedure. The habituation stimulus was presented four times for one minute, followed by the dishabituation stimulus presented once for one minute. Behavioral variables included spatiality relative to target odors, approach/withdrawal, ear positioning, sniffing, ingestion, and vocalization. Both female and male lambs more often positioned their ears backwards/forwards, and asymmetrically when exposed to the dishabituation stimulus, but regardless of their stress or non-stress value. They also changed their approach behavior when exposed to the dishabituation stimuli. Lambs displayed some behavioral signs of discrimination between the habituation and dishabituation odors, but regardless of their relation to stress or non-stress of human donors. In sum, this exploratory study suggests that young sheep respond negatively to the odor of unfamiliar humans, without showing any specific emotional contagion related to the stress odor. This exploratory study suggests young ovines can detect human body odor, a further step toward understanding the human-sheep relationship
Effect of extraction method on the calcium binding capacity of faba bean globulin fractions at various pH
No full textInternational audienceFaba bean ingredients are rich in proteins and good sources of calcium (Ca), although containing phytic acid (PA) molecules. PA, a polyphosphate compound, can affect the bioavailability of minerals/proteins through complex formation. This study evaluates the impact of two extraction processes, Alkaline Extraction-IsoElectric Precipitation (AE-IEP) and Sequential Extraction (SE), on the ability of faba bean globulin systems to bind added calcium ions. Increasing concentrations of CaCl2 were introduced into 2.5% (w/v) protein dispersions at pHs 4.5, 5.5, 6.5, and 7.5, and free Ca monitored. Near the isoelectric point of globulin (pH ∼ 4–5), Ca binding capacity was found to be low. At higher pHs, significant Ca chelation occurred, initially attributed to free PA binding sites, resulting in the formation of insoluble complexes and subsequent protein precipitation. The AE-IEP globulin fraction exhibited a higher Ca binding capacity than the SE globulin, attributed to its higher PA and lower initial Ca concentrations
Synthesis and characterization of new acid-functionalized porphyrins displaying antimicrobial activity against gram positive bacteria, yeasts and filamentous fungi with or without ultra-high irradiance
No full textInternational audienceThe antimicrobial activity of new acid-functionalized porphyrins, with or without ultra-high irradiance, was investigated. Antibacterial efficacy was evaluated against Staphylococcus aureus (methicillin-resistant or methicillin-sensitive strains) and antifungal efficacy was evaluated against the yeast Candida albicans and the filamentous fungi Aspergillus fumigatus.Overall, the porphyrins tested are more effective against S. aureus. The best results were obtained with zinc diacid porphyrins 4 and 5 after only 3 min of ultra-high irradiation (500 mW/cm2, 405 nm), demonstrating that acid-functionalized porphyrins are promising as novel antimicrobial drugs for surface disinfection