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Model of drop infiltration into a thin amphiphilic porous medium
No full textInternational audienceWater drop infiltration into a thin amphiphilic porous medium is influenced by wettability. Due to the reorganization of amphiphilic matter in contact with water, polar interaction changes the wettability in the bulk porous medium and at the liquid/porous substrate interface. To model out of equilibrium water transfer, we propose a thermodynamics approach derived from Onsager's principle. Modeling: A 2D macroscopic gradient-dynamics model coupling the drop infiltration and the water dynamic into an amphiphilic porous medium is developed and applied to rhizospheric soil in presence of exopolysaccharides (EPS) as an example. The free energy of the entire drop and porous medium system is defined by taking into account the free surface energy of the water and the effective interaction between the porous matrix and the amphiphilic matter. Findings: The temporal evolution of the 2D drop volume and contact angle are studied during infiltration using the new formulation. Depending on amphiphilic concentrations and initial water saturation, numerical simulation captures similar scenarios to those described in the literature for powder media, as well as a latency phenomenon occurring in dry soil. The latter has been until now poorly modele
Archaeocytes in sponges: simple cells of complicated fate
No full textInternational audienceArchaeocytes are considered a key cell type in sponges (Porifera). They are believed to be multifunctional cells performing various functions, from nutrient digestion to acting as adult stem cells (ASCs). Thus, archaeocytes are mentioned in discussions on various aspects of sponge biology. As presumed ASCs of an early‐diverged animal taxon, archaeocytes are of great fundamental interest for further progress in understanding tissue functioning in metazoans. However, the term ‘archaeocyte’ is rather ambiguous in its usage and understanding, and debates surrounding archaeocytes have persisted for over a century, reflecting the ongoing complexity of understanding their nature. This article presents a comprehensive revision of the archaeocyte concept, including both its historical development and biological features (i.e. taxonomic distribution, characteristics, and functions). The term ‘archaeocyte’ and its central aspects were introduced as early as the end of the 19th century based on data mainly from demosponges. Remarkably, despite the general lack of comparative and non‐histological data, these early studies already regarded archaeocytes as the ASCs of sponges. These early views were readily inherited by subsequent studies, often without proper verification, shaping views on many aspects of sponge biology for more than a century. Taking into account all available data, we propose considering the archaeocytes as a cell type specific to the class Demospongiae. Clear homologues of archaeocytes are absent in other sponge classes. In demosponges, the term ‘archaeocytes’ refers to mesohyl cells that have an amoeboid shape, nucleolated nuclei, and non‐specific inclusions in the cytoplasm. The absence of specific traits makes the archaeocytes a loosely defined and probably heterogeneous cell population, rendering the exhaustive characterisation of the ‘true’ archaeocyte population impossible. At the same time, the molecular characterisation of archaeocytes is only beginning to develop. Stemness and almost unlimited potency have always been at the core of the traditional archaeocyte concept. However, currently, the most consistent data on archaeocyte stem cell function come only from developing gemmules of freshwater sponges. For tissues of adult demosponges, the data favour a two‐component stem cell system, in which archaeocytes may cooperate with another stem cell population, choanocytes. Simultaneously, cells with archaeocyte morphology function as macrophages in demosponges, participating in the food digestion cycle and immune defence. Such cells should be denoted with the more neutral term ‘nucleolar amoebocytes’, as the term ‘archaeocyte’ not only describes the morphology of a cell but also introduces the proposition of its stem nature. Thus, the future usage of the term ‘archaeocyte’ should be limited to cases where a cell is shown or at least presumed to be a stem cell
Grapevine cell response to carbon deficiency requires transcriptome and methylome reprogramming
No full textInternational audienceSugar limitation has dramatic consequences on plant cells, which include cell metabolism and transcriptional reprogramming, and the recycling of cellular components to maintain fundamental cell functions. There is however no description of the contribution of epigenetic regulations to the adaptation of plant cells to limited carbon availability. We investigated this question using non-photosynthetic grapevine cells (Vitis vinifera, cv Cabernet Sauvignon) cultured in vitro with contrasted glucose concentrations. Sugar depletion in the culture medium led to a rapid cell growth arrest and a major metabolic shift that include the depletion in soluble sugar and total amino acids and modulation of the cell redox status. Consistently, flux modeling showed a dramatic slowdown of many pathways required for biomass accumulation such as cell wall and protein synthesis. Sugar depletion also resulted in a major transcriptional reprogramming, characterized by the induction of genes involved in photosynthesis, and the repression of those related to sucrose mobilization or cell cycle control. Similarly, the epigenetic landscape was deeply modified. Glucose-depleted cells showed a higher global DNA methylation level than those grown with glucose. Changes in DNA methylation mainly occurred at transposable elements, and at genes including some of those differentially expressed, consistent with an important role for methylation to the adaptation of cells to limited sugar availability. In addition, genes encoding histone modifiers were differentially expressed suggesting that additional epigenetic mechanisms may be at work in plant cells under carbon shortage
Procédé traditionnel de fabrication de beignets de niébé : innover pour faciliter la production et répondre aux attentes nutritionnelles et sensorielles
No full textCe volume fait suite aux Rencontres Francophone Légumineuses (RFL) de mars 2024 organisées par le Cirad, INRAE, Terres Inovia et Terres Univia, et co-organisé par l'Institut Sénégalais de Recherches Agricoles (ISRA). Ce rendez-vous unique entre tous les acteurs du développement, des filières et de la recherche sur les légumineuses à graines et fourragères. L’occasion de croiser les regards, partager les connaissances et accélérer l’innovation autour des légumineuses.Les RFLs s’intéressent aux légumineuses à graines, fourragères ou ligneuses, et visent à couvrir la diversité des systèmes de production, ainsi que la diversité des usages : alimentation humaine, animale et non-alimentaire.Les légumineuses sont un levier majeur pour relever les défis mondiaux du changement climatique et de la sécurité alimentaire et nutritionnelle. Partout dans le monde, elles disposent d’un rôle stratégique : atouts nutritionnels, souveraineté protéique et alimentaire. Les nombreuses espèces de légumineuses constituent également un formidable vivier d’innovations alimentaires.National audienceThe study focuses on the processing of cowpeas into Ata doughnuts in Benin, with the aim of improvingthe work of women processors. Traditionally, cowpeas are dehulled manually using water, a tedious andtime-consuming step. Two innovative products have been developed using the dry method: partiallydehulled cotyledons and flour made from these cotyledons. The use of these products, and in particularthe flour, simplifies the doughnut-making process and reduces water consumption, but with highermaterial losses. Sensory tests and nutritional analyses show promising results, although adjustments arestill needed, particularly to the alpha-galactoside content of the flour. These innovations are helping toimprove processing methods and add value to local products, thereby supporting food security and thelocal economy.L'étude se concentre sur la transformation du niébé en beignets Ata au Bénin, dans l'objectif de faciliter le travail des transformatrices. Traditionnellement, le niébé est décortiqué manuellement à l'eau, une étape fastidieuse et chronophage. Deux produits innovants ont été développés par voie sèche : des cotylédons partiellement décortiqués et de la farine issue de ces cotylédons. L'usage de ces produits et notamment de la farine, simplifie le procédé d'élaboration des beignets et réduit la consommation d'eau, mais avec des pertes en matière plus élevées. Les tests sensoriels et les analyses nutritionnelles montrent des résultats prometteurs, bien que des ajustements soient nécessaires, en particulier au niveau de la teneur en alpha-galactosides de la farine. Ces innovations contribuent à l'amélioration des procédés de transformation et à la valorisation des produits locaux, soutenant ainsi la sécurité alimentaire et l'économie locale
"Le vilain qui od sa fame vit aler son dru" de Marie de France - Édition et notes d'après le manuscrit York, Minster Library, XVI s. K-12 Pt. I
No full textÉdition et notes du "Vilain qui od sa fame vit aler son dru" de Marie de France d'après le manuscrit York, Minster Library, XVI s. K-12 Pt.
Le vallet aus douze fames - Édition, traduction et notes d'après le manuscrit Berlin, Staatsbibliothek und Preussischer Kulturbesitz, Hamilton 257
No full textÉdition, traduction et notes du Vallet aus douze fames d'après le manuscrit Berlin, Staatsbibliothek und Preussischer Kulturbesitz, Hamilton 25
Le moigne - Édition, traduction et notes d'après le manuscrit BnF Rothschild 2800
No full textÉdition, traduction et notes du Moigne d'après le manuscrit BnF Rothschild 280
La dame escoillee - Édition et notes d'après le manuscrit BnF fr. 12603
No full textÉdition et notes de La dame escoillee d'après le ms. BnF fr. 1260
Navigating the complexity of lipid oxidation and antioxidation: A review of evaluation methods and emerging approaches
No full textInternational audienceLipid oxidative degradation contributes to the deterioration of food quality and poses potential health risks. A promising approach to counteract this is the use of plant-based antioxidants. However, accurately evaluating the antioxidant capacity and effectiveness of these compounds remains a challenge. While many rapid in vitro tests are available, they must be categorized according to their specific responses to avoid overinterpreting results. This review opens with an overview of current knowledge on lipid autoxidation and recent findings that highlight the challenges in measuring antioxidant capacity. We then examine various methods, addressing their limitations in accurately anticipating outcomes in complex compartmentalized lipid systems. The aim is to clarify the gap between predictions and real-world efficacy in final products. Additionally, the review compares the strengths and weaknesses of methods used to evaluate antioxidant capacity and assess oxidation degrees in complex environments, such as those found in food and cosmetics. Finally, new analytical techniques for multiproduct detection are introduced, paving the way for a more 'omic' and spatiotemporally defined approach.</div
What next? Some practical suggestions for future studies on fence ecology
No full textInternational audiencePractical gaps in knowledge of fence ecology or its specific requirements still exist despite numerous recommendations scattered throughout various articles. We recently carried out two different studies on fences in a French context whose results corroborate this observation, and highlight the need to synthetise and prioritise scientific and technical research. The first study was an exploratory research project on escape devices used to allow ungulates to exit fenced transport infrastructure right‐of‐way. The second study entailed drafting a guide on the mitigation of the fence's ecological impacts, using solar energy plants as a case study. Both were based on different types of information gathering, ranging from bibliographical research to interviews with governments officials, operating companies, engineering offices, naturalists and hunters' associations. Based on the similarities between these two studies, the urgency of certain needs, and the clear potential for these approaches to extend beyond France's borders, we have identified two key categories for future actions. The first category is a series of six research priorities: Diversifying monitoring of exclusion fencing; Developing practice‐oriented fence mapping tools; Further studying the impact of fencing on animal vehicle collisions; Considering animal behaviour in monitoring protocol; Ex‐situ testing of devices' effectiveness; and Studying large‐scale effects of fencing. The second category comprises six method recommendations: Accurately documenting fences; Early planning of scientific monitoring; Contextualising fencing requirements; Defining effectiveness goals and criteria; Taking advantage of opportunistic Animal‐Fence Event observations; and Developing artificial intelligence and computer vision to map fences. All these items are supported by examples drawn from one study or the other. Our conclusions indicate that, in the context of major expansion of fences, such recommendations must be integrated at all stages of development work. If this is not implemented, the free movement of animal species will not be adequately protected and the erosion of biodiversity will be further exacerbated