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Roles of Interelectrode Distances and Mass Transport Effects on Electrochemical CO2 Reduction to Formic Acid under Low Carbonate Concentration Solutions
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Impact des boiteries sur les comportements de lever et de coucher dans l'objectif d'une détection précoce chez les bovins laitiers
No full textLa boiterie est un enjeu majeur en élevage laitier, tant sur le plan économique que pour le bien-être animal. Elle reste souvent sous-détectée, alors même que des modifications comportementales peuvent survenir précocement. Parmi elles, les comportements de lever et de coucher constituent des moments clés pouvant refléter une douleur locomotrice. La littérature décrit principalement l’impact des boiteries sur des indicateurs globaux tels que la durée totale de couchage ou la fréquence des transitions posturales. L’objectif de cette étude est de compléter ces approches en proposant une analyse séquentielle des comportements de lever et de coucher, décomposés en phases distinctes. La durée et la répétabilité de ces phases ont été mesurées à partir de 345 vidéos annotées chez des vaches Prim’Holstein. Les résultats montrent qu’une phase du lever – entre l’extension de l’encolure et le placement du museau au ras du sol – est significativement allongée chez les vaches boiteuses, traduisant une gêne à l’engagement des postérieurs (OR = 2,94 ; IC95 : [1,12–7,72] ; p = 0,03 ; médiane = 0,88 s [Q1 = 0,63 s ; Q3 = 1,22s]). À l’inverse, une phase du coucher – entre le posé du second antérieur et le début du mouvement du premier postérieur – est significativement plus courte chez les vaches boiteuses, suggérant une instabilité à cette étape (OR = 0,75 ; IC95% = [0,56 – 1,00] ; p = 0,05 ; médiane = 0,60 s [Q1 = 0,30 s ; Q3 = 1,07s]). Une de ces deux phases figure également parmi les variables les plus prédictives dans un des modèles XGBoost, confirmant sa pertinence. Toutefois, les performances du modèle restent limitées (56 % de précision pour le lever, 69,8 % pour le coucher), probablement en raison de la taille de l’échantillon et de la complexité du phénomène. Ces résultats soutiennent le potentiel de ces indicateurs pour une détection précoce automatisée
Designing Biomaterials with Oriented Organic Nanocrystals for Tissue Engineering Applications
No full textInternational audienceThe extracellular matrix (ECM) has a specific architecture that defines tissue mechanics and helps to guide cell functions. In tissue engineering, it is crucial to be able to mimic the architecture and mechanics of the ECM with biomaterials. However, mimicking the architecture and mechanics of tissues that contain ECM elements oriented at the nanoscale, such as articular cartilage, tendon, and intervertebral disc, and cornea, remains challenging. To succeed, an emerging strategy is to orient nanocrystals within materials by using manufacturing techniques such as extrusion printing and magnetic induction. This strategy is increasingly used in tissue engineering where it can help to produce mechanically reinforced biomaterial scaffolds and spatially organize cells. This review introduces techniques that allow for orienting organic nanocrystals within materials and discusses their potential and limitations for tissue engineering applications. First, it presents an overview of the classes of organic nanocrystals used in tissue engineering, before summarizing the state of the art in the processing of oriented nanocrystals. Then, the use of materials containing oriented nanocrystals is discussed for two major applications, i.e., mechanical reinforcement and cell alignment. Finally, new avenues of research are proposed to advance this emerging class of materials toward biomedical applications.Statement of SignificanceIn tissue engineering, one major challenge is to mimic the architecture of the cell microenvironment down to the nanoscale. To succeed, one strategy is to use fabrication techniques that allow the orientation of nanocrystals within materials. This review presents the state of the art in the design of biomaterials with oriented nanocrystals and discusses their potential in tissue engineering
Electroanalytical methods for monitoring pollutants during (photo)-(electro)-catalytic treatments of wastewater – A critical review on possible hybrid vs sequenced combinations
No full textInternational audienceElectrochemical analysis of the wastewater pollutants during their degradation by electrochemical and photocatalytical techniques has been reviewed for the first time. Electroanalysis is convenient compared to chromatographic methods, due to its simplicity and cost-effectiveness, though interferences could restrict its use. The electroanalytical methods used during the degradation processes were: differential pulse voltammetry (DPV), square wave voltammetry (SWV), cyclic voltammetry (CV), linear scan voltammetry (LSV), and chronoamperometry (CA). DPV and SWV were the most used techniques due to their higher sensitivity and selectivity. Electroanalysis has been more performed during photochemical than during electrochemical treatments. In addition, the combination was mostly performed in sequence, while only few cases investigated the hybrid coupling, in which in situ analyses took place. Advantages and drawbacks of the sequenced versus hybrid system have been discussed, while more intensive studies need to performed to improve the promising possibility of the in situ combination
Analyse et optimisation de la machine façonneuse dans la production de pains grillés : identification des causes techniques et humaines des pertes et impact sur la qualité des produits finis
No full textThe Brioche Pasquier factory in Saint-Herblain faces significant losses related to the shaping machine. The location and causes of these losses, whether technical or human, are not clearly identified. In this context, the DMAIC methodology was applied to analyze the machine’s parameters, operator skill management, and product quality. Action plans were proposed to reduce losses, improve product consistency, and optimize the machine’s performance.L’usine Brioche Pasquier à Saint-Herblain est confrontée à des pertes importantes liées à la machine façonneuse. La localisation et les causes de ces pertes, qu’elles soient d’origine technique ou humaine, ne sont pas clairement établies. Dans ce contexte, la méthodologie DMAIC a été appliquée pour analyser les paramètres de la machine, la gestion des compétences des opérateurs et la qualité des produits finis. Des plans d’action ont été proposés pour minimiser les pertes, améliorer la régularité des produits et optimiser le fonctionnement de la machine
Remise en état et optimisation du NEP (Nettoyage En Place)
No full textAs part of my final year of training as a food engineering student, this dissertation presents an industrial improvement project carried out at Fournil du Val de Loire, a cereal-sector plant within the Agromousquetaires group. The mission focused on optimizing the Cleaning-in-Place (CIP) system, responsible for washing the liquid raw material circuits (eggs, yeast, invert sugar). The CIP process is critical to ensuring equipment hygiene and food safety. The initial assessment revealed several shortcomings: insufficient cleaning efficiency, deviations in critical parameters, incomplete documentation, and contamination risks. In response to these findings, a structured improvement approach was implemented, inspired by the DMAIC model (Define, Measure, Analyze, Innovate, Control). This enabled a detailed technical diagnosis, the implementation of corrective actions (repairs, adjustments, program modifications, addition of sensors), the rebuilding of documentation standards and staff training, as well as rigorous monitoring of results, validated through field measurements and an external audit. The results obtained demonstrate a significant improvement in the performance of the CIP system, in terms of efficiency, reliability, and regulatory compliance. This project has strengthened process hygiene control and laid the foundation for a sustainable continuous improvement approach.Dans le cadre de ma dernière année de formation d'ingénieur en agroalimentaire, ce mémoire présente un projet d'amélioration industrielle réalisé au sein du Fournil du Val de Loire, usine de la filière céréales du groupement Agromousquetaires. La mission a porté sur l'optimisation du système de nettoyage en place (NEP), chargé du lavage des circuits de matières premières liquides (oeufs, levure, sucre inverti). Le NEP constitue un processus critique pour garantir l'hygiène des équipements et la sécurité sanitaire des produits. Le diagnostic initial a révélé plusieurs défaillances : efficacité de lavage insuffisante, dérives des paramètres critiques, documentation incomplète et risques de contamination. Face à ces constats, une démarche structurée d'amélioration a été mise en œuvre, inspirée du modèle DMAIC (Définir, Mesurer, Analyser, Innover, Contrôler). Elle a permis de réaliser un diagnostic technique détaillé, de mettre en place des actions correctives (réparations, réglages, modifications des programmes, ajouts de capteurs), de reconstruire les standards documentaires et la formation du personnel, et d'assurer un suivi rigoureux des résultats, validés par des mesures terrain et un audit externe. Les résultats obtenus montrent une amélioration significative de la performance du NEP, tant en efficacité qu'en fiabilité et conformité réglementaire. Ce projet a renforcé la maîtrise sanitaire des process et posé les bases d'une démarche d'amélioration continue durable
Immunomodulation by extracellular vesicles from mature or mesenchymal stem cells in the lymph node microenvironment
No full textInternational audienceSmall extracellular vesicles (sEV) with immunomodulatory properties are promising candidates for therapeutic innovation, primarily with the use of mesenchymal stem cells-derived EV (MSC-EV) carrying immune regulatory and regenerative signals. Unlike EV produced by differentiated cells, EV from MSC lack antigen expression required for the induction of long-lasting immune memory; this hinders the application of MSC-EV to autoimmune and antigen-specific immune diseases. Growing evidence shows that a continuous lymphatic drainage of EV derived from mature cells contributes to the immune surveillance and maintenance of tolerance to self and innocuous foreign antigens. Type 1 diabetes is an autoimmune disease caused by the targeted destruction of insulin-producing pancreatic beta cells. EV derived from naïve beta cells (beta-EV) have been reported to exert immune-protective effects. Here, we are interested in the mechanisms of immune modulation induced by beta-EV, carrying beta cell auto-antigens, or tolerogenic MSC-EV, on immune responses in the lymph node.For this purpose, sEV from the MIN-6 murine pancreatic beta cell line or from a human BM-MSC immortalised cell line were isolated by tangential flow filtration and size exclusion chromatography. Characterization included NTA, cryo-EM, flow cytometry and protein cargo analyses, in compliance with the MISEV2023 guidelines. sEV function was studied in vitro using an allogenic mixed lymphocyte reaction (MLR). In vivo, sEV injected intradermally were analysed for their aptitude to target lymphoid organs: lymph nodes were analysed by imaging with light sheet microscopy and transcriptomic arrays, and in parallel serum cytokines were measured. We found that MIN-6 sEV express an immuno-active cargo, with beta cell antigens as well as molecules involved in cell recruitment, metabolic control, integrin signalling and immune-regulation. In an MLR assay, beta-EV showed a dose-dependent reduction of T lymphocyte proliferation and cytokine secretion, in support of a regulatory function. Moreover, intradermal administration of sEV allows the targeting of secondary lymphoid organs through lymphatic drainage. Targeted transcriptomic analysis revealed significant down-regulation of molecular pathways involved in the recruitment and activation of innate and adaptive immune cells. This ongoing study paves the way for future clinical developments of EV-based antigen-specific immune therapy
Genetic diversity of equine piroplasmosis agents in Guadeloupe (Caribbeans): First report of Theileria haneyi, evaluation of diagnostic tools and impact of horse movement
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/615838/)International audienceEquine piroplasmosis is a major tick-borne horse disease, caused by the intracellular development of piroplasms (Theileria equi sensu lato and Babesia caballi), with significant economic and sanitary consequences. In 2024, 203 blood samples were collected in Guadeloupe (Caribbean) from asymptomatic horses. Using an 18S rRNA nested PCR (nPCR) specific for each equine genus parasite, 79 samples tested positive for Theileria equi and 9 for Babesia caballi, resulting in respective prevalence of 38.9% and 4.4%. Three horses were co-infected. For B. caballi, 18S rRNA sequence analysis revealed the presence of the genotype A only. For T. equi, the genotypes A and C were evidenced as mono-infections A (16/79, 20.3% of the infected horses) or mono-infections C (15/79, 19.0% of the infected horses). Interestingly, mono-infections with T. equi genotype E (17/79, 21.5% of the infected horses) were also detected, but only on horses imported from Europe and especially from metropolitan France, where this genotype is dominant. Further characterization using published T. equi ema-1 and T. haneyi specific nPCRs revealed two major points. First, most 18S rRNA genotype C isolates (13/15) were detected using the T. haneyi specific nPCR. Second, the genotype E of T. equi could not be detected by any of these two nPCRs. Co-infection occurrence and types were then evaluated using a combination of the three analyses: 18S rRNA sequencing, T. haneyi specific nPCR and T. equi ema-1 nPCR. Horses co-infected with the genotypes A and C (T. haneyi) represented the main population (32/79, 40.5% of the infected horses), while the co-infections AE (5/79, 6.3% of the horses) and CE (2/79, 2.5% of the horses) were rare. One horse was detected with a triple infection ACE. Taking into account all detected genotypes (120), 45.0% of the isolates belonged to the genotype A (54/120), 38.3% to the genotype C T. haneyi (46/120) and 16.7% to the Eurasian genotype E (20/120). The rarity of co-infections with the genotype E and the absence of this genotype on locally born horses suggest the absence of transmission of the genotype E by locally present vector ticks. This work represents the first molecular record of Theileria haneyi in South and Central America and in the Caribbeans. We also demonstrate the introduction of T. equi genotype E from Europe with infected horses but not its installation, as well as a diagnostic issue to detect this genotype using PCR targeting ema-1 gene
Respiratory infectious risk factors of poor performance in racehorses
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