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Sexual dimorphism in PAR2-dependent regulation of primitive colonic cells
No full textBackground:Sexual dimorphism in biological responses is a critical knowledge for therapeutic proposals. However,gender differences in intestinal stem cell physiology have been poorly studied. Given the important role of theprotease-activated receptor PAR2in the control of colon epithelial primitive cells and cell cycle genes, we haveperformed a sex-based comparison of its expression and of the effects of PAR2activation or knockout on cellproliferation and survival functions.
Methods:Epithelial primitive cells isolated from colons from male and female mice were cultured as colonoids, andtheir number and size were measured. PAR2activation was triggered by the addition of SLIGRL agonist peptide inthe culture medium. PAR2-deficient mice were used to study the impact of PAR2expression on colon epithelial cellculture and gene expression.
Results:Colonoids from female mice were more abundant and larger compared to males, and these differenceswere further increased after PAR2activation by specific PAR2agonist peptide. The proliferation of male epithelialcells was lower compared to females but was specifically increased in PAR2knockout male cells. PAR2expressionwas higher in male colon cells compared to females and controlled the gene expression and activation of keynegative signals of the primitive cell proliferation. This PAR2-dependent brake on the proliferation of male colonprimitive cells was correlated with stress resistance.[br/]
Conclusions:Altogether, these data demonstrate that there is a sexual dimorphism in the PAR2-dependentregulation of primitive cells of the colon crypt
Prebiotics: mechanisms and preventive effects in allergy.
No full textAllergic diseases now affect over 30% of individuals in many communities, particularly young children, underscoring the need for effective prevention strategies in early life. These allergic conditions have been linked to environmental and lifestyle changes driving the dysfunction of three interdependent biological systems: microbiota, epithelial barrier and immune system. While this is multifactorial, dietary changes are of particular interest in the altered establishment and maturation of the microbiome, including the associated profile of metabolites that modulate immune development and barrier function. Prebiotics are non-digestible food ingredients that beneficially influence the health of the host by 1) acting as a fermentable substrate for some specific commensal host bacteria leading to the release of short-chain fatty acids in the gut intestinal tract influencing many molecular and cellular processes; 2) acting directly on several compartments and specifically on different patterns of cells (epithelial and immune cells). Nutrients with prebiotic properties are therefore of central interest in allergy prevention for their potential to promote a more tolerogenic environment through these multiple pathways. Both observational studies and experimental models lend further credence to this hypothesis. In this review, we describe both the mechanisms and the therapeutic evidence from preclinical and clinical studies exploring the role of prebiotics in allergy prevention
Des restrictions en eau et en azote modérées et durables peuvent-elles contribuer au contrôle des infestations de pucerons en verger commercial de pêcher ?
No full textLe pêcher est affecté par de nombreux insectes phytophages parmi lesquels les pucerons. Ces insectes provoquent des dégâts très important. En raison du changement climatique, leur population augmente. Pour faire face à ces dégâts l’augmentation de l’utilisation des produits phytosanitaires ne cessent d’accroitre. Des moyens alternatifs peuvent être utilisés afin de réduire l’utilisation des pesticides pour protéger l’environnement. Les pratiques culturales peuvent contribuer au contrôle des bio-agresseurs en influant la croissance de la plante. L'objectif de notre étude est d'évaluer dans quelle mesure les pratiques de fertilisation et d'irrigation peuvent être optimisées sur des critères à la fois de production et de gestion de bio-agresseurs. Pour ce faire, des suivis de croissance et de l’état hydrique des arbres et des suivis d’infestation des pucerons ont été effectués. D’après les résultats obtenus, le traitement limité en eau et en azote retarde l’infestation des pucerons. Cependant, il semblerait qu’au niveau de l’arbre les traitements n’aient pas d’impact sur le nombre de feuilles et le nombre d’axes et de rosettes de la variété Ivoire en 2018 et 2019 mais peu d’effet sur la variété Conquise en 2018. De plus, la sévérité d’infestation semble dépendre de la croissance individuelle des rameaux en 2019. L’infestation des pucerons altère la photosynthèse en 2018 et 2019 et modifie la composition biochimique de l’apex et des fruits ainsi que la taille des fruits en 2018.The peach tree is affected by many phytophagous insects including aphids. These insects cause very significant damage. Due to climate change, their population is increasing. To cope with this damage, the increase in the use of phytosanitary products continues to increase. Alternative means can be used to reduce the use of pesticides to protect the environment. Cultural practices can help control bio-aggressors by influencing the growth of the plant. The objective of our study is to evaluate the extent to which fertilization and irrigation practices can be optimized on the criteria of both production and management of bio-aggressors. To do this, monitoring of growth and water status of trees and monitoring of infestation of aphids were carried out. Based on the results obtained, limited treatment with water and nitrogen delays the infestation of aphids. However, it appears that at the tree level the treatments have no impact on the number of leaves and the number of axes and rosettes of the Ivory variety in 2018 and 2019 but little effect on the variety Conquered in 2018. In addition, the severity of infestation appears to be dependent on individual twig growth in 2019. Aphid infestation impairs photosynthesis in 2018 and 2019 and modifies the biochemical composition of the apex and fruits as well as the size of the fruits in 2018
Sharing Values for Changing Practices, a Lever for Sustainable Transformation? The Case of Farmers and Processors in Interaction within Localized Cheese Sectors
No full textInternational research and development organizations have acknowledged that localized agrifood systems, particularly geographical indications (GIs), are a lever for evolving towards sustainable agriculture. Such a premise is neither spontaneous nor systematic. Research and development organizations show their limit in proposing approaches to overcome this raised issue: The performance-based approach of sustainability, associated with a strict economical understanding of activities, is at stake. We propose the introduction of a values-based approach to the understanding of localized activities and their contribution to sustainability. We base our demonstration on the study of the relationships between stakeholders within GIs on a day-to-day basis: Corsica and Western Pyrenees (WP) are regions where traditional cheeses (respectively GI Brocciu and GI Ossau-Iraty) are produced with ewe milk. We build a typology of relationships between farmers providing the milk and dairies, based on the theory of worlds of worth (from industrial to artisanal). We cross-reference it with values given to milk and cheese. Despite the framing role of GIs, milk is mainly valued according to industrial criteria of quantity and sound farming practices have no weightage. However, artisanal and civic initiatives have emerged using raw milk and fostering more sustainable practices, notably based on organic farming. Though those initiatives are currently marginal, they might be promising seeds of change
CAP ReD : Cerisier Abricotier Pruniers - Réduction des intrants et durabilité des systèmes de production
No full textCAP ReD vise à concevoir et évaluer des vergers de cerisier, abricotier, prunier d’Ente, prunier américano-japonais et mirabellier, permettant de réduire l’usage des produits phytosanitaires par deux, tout en conservant les performances technico-économiques. Les expérimentations systèmes, conduites par 9 partenaires dans 10 sites de 2013 à 2018, combinent de nombreux leviers d’action (génétique, physique, biotechnique, biologique…), depuis le choix à la plantation, jusqu’à la gestion annuelle des vergers. Ainsi, 17 systèmes économes en produits phytosanitaires (ECO) sont comparés chaque année à 11 systèmes de référence (PFI). Ces systèmes ECO ont permis une réduction moyenne de 58% des IFT hors biocontrôle (5.1 vs 12.2 en PFI). L’objectif « zéro herbicide » a été atteint dans la majorité des systèmes, deux leviers ont fait leur preuve : le désherbage mécanique et la bâche tissée au sol. Le rendement commercialisable est plus faible dans ECO (-19 %), sauf dans les systèmes à haute densité ou biaxe d’arbres. Les systèmes ECO de CAP ReD nécessitent aussi plus de temps de travail pour produire une tonne de fruits. Cette perte de production et d’efficience n’est pas compensée par une augmentation du prix de vente des fruits dans les systèmes ECO, aussi les performances économiques sont moindres. Ainsi, le coût de production des systèmes ECO est en moyenne supérieur de 20%, soit +0.15€/kg. 47% des systèmes ECO (n=8) sont classés Systèmes Economes et Performants (SCEP). Ce sont soit, i) des systèmes avec filets anti-insectes, bâche anti-pluie, réduction de dose avec pulvérisation innovante, conduits en haute densité ou biaxe, mais ayant de fortes charges d’amortissement ; soit ii) des systèmes valorisant leurs fruits en industrie, avec des coûts de production moindres (moins de déchet, récolte mécanique), utilisant des Outils d’Aide à la Décision, biocontrôles et impasses. Ces résultats montrent la faisabilité technique d’une forte réduction des produits phytosanitaires, diminuant les risques d’impacts sur l’environnement et la santé humaine, mais aussi la difficulté économique qu’engendrent ces changements de pratiques pour le producteur, sans revalorisation des prix.CAP ReD aims to design and evaluate cherry, apricot, Ente plum, Japanese-American plum and mirabelle plum orchards, so that the use of phytosanitary products is halved, while maintaining the technico-economic performance. System experiments, conducted by 9 partners at 10 sites from 2013 to 2018, combined many levers of action (genetics, physics, biotechnology, biology ...), and choices were made from planting the trees to the annual management of orchards. For example, 17 low-pesticide-input control systems (LPIC) were compared each year to 11 reference systems (IFP). These LPIC systems, excluding biocontrol, achieved an average reduction of 58% of IFT (5.1 / 12.2 in IFP). The goal of “zero herbicide cultivation” was achieved in the majority of systems, of which two levers proved their worth: mechanical weeding and the woven weed control ground cover. Marketable yield was lower with the LPIC systems (-19%) except in high density orchards. CAP ReD's LPIC systems also required more work time to produce one tonne of fruit. This loss of production and efficiency is not offset by an increase in the sales price in the LPIC systems, so the economic performance is lower. Thus, the costs of production with LPIC systems is on average 20% higher, i.e. + 0.15 € / kg. 47% of LPIC systems (8/17) are classified as Economical and Efficient Systems. These are either i) high-density systems with insect nets, rain covers, dose reduction with innovative spraying techniques, but with high depreciation costs; or ii) systems of which the fruit are intended for the processing industry with lower production costs (no waste, mechanical harvesting), using decision-support tools, biocontrols and reduction of certain treatments. These results show the technical feasibility of a considerable reduction of phytosanitary product use, decreasing the risks of impacts on the environment and human health, but also the economic difficulty that these changes of practice generate for the grower, without revaluating prices
Methodology to co-design temperate fruit tree-based agroforesty systems: three case studies in Southern France
No full textDiversification of fruit tree species, cultivars, crops and companion plants is a way to reinforce ecosystem services towards productive and ‘pest suppressive’ fruit-tree based agroforestry systems (FT-AFS). We analyzed the approach and the outputs of three design processes that shared the same objectives of ecological intensification and diversification in FT-AFS. The approach targeted ‘pest suppressive’ processes but also resource use optimization within time and space between productive and associated plants. Basic and applied knowledge on ecological and biophysical processes, feedbacks and experiences of various stakeholders in the fruitchain permitted to make tradeoff between agronomic, ecological and organizational aspects. For genericity purpose, the functions of each plant species or assemblage (e.g. barrier, trap, production) were identified taking into account growth dynamics over time. The set-up of those FT-AFS prototypes implies changes in technics due to the spatial design (e.g. machinery adaptation, ergonomics) and changes in management of the agroecosystem, made ‘on the way’ considering the objectives and design principles as dynamic guidelines. The trajectory and performances of those systems are now assessed through multicriteria evaluation including organizational aspects and products’ valorization. All steps include an interdisciplinary and participative approach fostering exchanges, knowledge sharing and building, and providing innovative avenues in FT-AFS.
Overal
Insect odorscapes: from plant volatiles to natural olfactory scenes
No full textOlfaction is an essential sensory modality for insects and their olfactory environment is mostly made up of plant-emitted volatiles. The terrestrial vegetation produces an amazing diversity of volatile compounds, which are then transported, mixed and degraded in the atmosphere. Each insect species expresses a set of olfactory receptors that bind part of the volatile compounds present in its habitat. Insect odorscapes are thus defined as species-specific olfactory spaces, dependent on the local habitat, and dynamic in time. Manipulations of pest-insect odorscapes are a promising approach to answer the strong demand for pesticide-free plant-protection strategies. Moreover, understanding their olfactory environment becomes a major concern in the context of global climatic change and environmental stresses to insect populations. A considerable amount of information is available on the identity of volatiles mediating biotic interactions that involve insects. However, in the large body of research devoted to understanding how insects use olfaction to locate resources, an integrative vision of the olfactory environment has rarely been reached. This article aims to better apprehend the nature of the insect odorscape and its importance to insect behavioral ecology by reviewing the literature specific to different disciplines from plant ecophysiology to insect neuroethology. First, we discuss the determinants of odorscape composition, from the production of volatiles by plants (Section II) to their filtering during detection by the olfactory system of insects (Section III). We then summarize the physical and chemical processes by which volatile chemicals distribute in space (Section IV) and time (Section V) in the atmosphere. The following sections consider the ecological importance of background odors and how insects adapt to their olfactory environment. Habitat provides an odor background and a sensory context that modulate the responses of insects to pheromones and other olfactory signals (Section VI). In addition, insects do not respond inflexibly to single elements in their odorscape but integrate several components of their environment (Section VII). We finally discuss existing methods of odorscape manipulations for sustainable pest insect control and potential future developments in the context of agroecology (Section VIII)
Towards sustainable dairy management. A machine learning enhanced method for estrus detection
No full textOur research tackles the challenge of milk production resource use efficiency in dairy farms with machine learning methods. Reproduction is a key factor for dairy farm performance since cows milk production begin with the birth of a calf. Therefore, detecting estrus, the only period when the cow is susceptible to pregnancy, is crucial for farm efficiency. Our goal is to enhance estrus detection (performance, interpretability), especially on the currently undetected silent estrus (35% of total estrus), and allow farmers to rely on automatic estrus detection solutions based on affordable data (activity, temperature). In this paper, we first propose a novel approach with real-world data analysis to address both behavioral and silent estrus detection through machine learning methods. Second, we present LCE, a local cascade based algorithm that significantly outperforms a typical commercial solution for
estrus detection, driven by its ability to detect silent estrus. Then, our study reveals the pivotal role of activity sensors deployment in estrus detection. Finally, we propose an approach relying on global and local (behavioral versus silent) algorithm interpretability (SHAP) to reduce the mistrust in estrus detection solutions
