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Caractérisation de l’infiltrat lymphocytaire CD3+ intestinal chez le chien atteint de maladie inflammatoire chronique de l’intestin
No full textLes maladies inflammatoires chroniques de l’intestin (MICI) du chien représentent un enjeu diagnostique et thérapeutique majeur en médecine vétérinaire. Cette étude vise à mieux caractériser la réponse immunitaire locale au sein de la muqueuse intestinale chez le chien atteint de MICI, en s’appuyant sur une analyse quantitative des lymphocytes T CD3+. À partir de prélèvements histologiques intestinaux archivés, des colorations immunohistochimiques anti-CD3 ont été réalisées sur des échantillons de duodénum, iléon et côlon de 42 chiens atteints de MICI et de 14 chiens sains. Les images ont été numérisées puis analysées à l’aide du logiciel QuPath® , permettant de quantifier le ratio (cellules CD3+/ cellules totales) (RCD3). Les résultats révèlent une augmentation significative du RCD3 dans le duodénum, l’iléon et le côlon des chiens malades (resp. : 5.3%, 7.9%, 3.0%) par rapport aux chiens sains (resp. : 2.3%, 1.1%, 1.3%). Toutefois, la distribution de ces valeurs est très hétérogène avec une proportion importante d’individus malades qui présentent des intensités d’infiltration très faibles. Aucune corrélation claire n’a pu être établie entre le RCD3 et les scores cliniques ou les concentrations sériques en albumine et cobalamine. Ces résultats suggèrent que l'infiltration lymphocytaire CD3+, faiblement présente physiologiquement et plus marquée chez les individus malades, est indépendante des variables cliniques et biologiques de l’individu. L’étude souligne l’intérêt d’une approche standardisée et quantitative pour évaluer l’inflammation intestinale, et ouvre la voie à une meilleure compréhension des mécanismes immunitaires impliqués dans les entéropathies chroniques canines
Une approche pluridisciplinaire au service d'une bioéconomie circulaire territoriale : exemple du projet Bioloop
No full textInternational audienceLe projet Bioloop est né d’un constat partagé : nos territoires sont aujourd’hui confrontés à des pressions croissantes sur leurs ressources, notamment en milieu urbain. Face à ces enjeux, il devient indispensable d’imaginer des solutions circulaires et durables.Dans ce contexte, les biodéchets et les coproduits, longtemps perçus comme des rebuts, apparaissent désormais comme des gisements à fort potentiel. Ils représentent une opportunité pour repenser nos modes de production et de consommation.L’objectif de Bioloop est donc ambitieux, mais concret : boucler localement les flux de matière. Il s’agit de transformer les coproduits organiques – dans la cas du projet du Bioloop, les drêches de bière – en ressources utiles, en s’appuyant sur les dynamiques territoriales. Cette démarche favorise à la fois la réduction des déchets et la création de valeur au sein des communautés locales
Neural-Accelerated Dynamic modeling of heat pumps
No full textInternational audienceIn response to escalating climate challenges and the transition to renewable energy, integrating heat pumps with other energy systems has gained significant attention. Fast and accurate dynamic models for heat pump are essential in predicting its transient thermal behavior and simulating its interactions with other energy systems, and effectively controlling and optimizing its performance in real time. Among the heat pump's components, heat exchangers involve complex heat transfer phenomenon and contributes to majority of the dynamics of the heat pump. Among the common numerical approaches used in the dynamic modeling of heat exchangers, the finite-volume method is well-recognized for its robustness and high accuracy. However, it is often outpaced in terms of computational efficiency compared to other methods. This paper introduces novel Neural-Accelerated Dynamic (NAD) models for heat pump's heat exchangers, integrating the strengths of numerical modeling and machine learning. The NAD model's architecture comprises of simplified heat exchanger model and a deep neural network, which are dynamically strongly coupled, achieving a computationally efficient model while maintaining high precision. Furthermore, in validation, the NAD models demonstrated excellent computational performance, achieving an average error below 0.4% and operating on average 271 times faster than the state-of-the-art finite-volume model. This highlights the capability of the NAD model to rapidly and precisely approximate complex heat transfer interactions in heat exchangers of the heat pump, making it particularly suitable for model control applications, optimization tasks, and long-duration simulations
Emergency Dyspnea in 258 Cats: Insights from the French RAPID CAT Study
No full textInternational audienceDyspnea is common in feline emergency medicine. Dyspneic cats are often unable to tolerate additional diagnostic tests upon admission. The aim of this study was to determine the relative frequency of the causes of severe dyspnea in cats and to identify clinical indicators that could guide immediate management. Records of 312 severely dyspneic cats admitted over a 5-year period to our institution’s emergency and critical care unit were retrospectively reviewed. The cause of dyspnea was identified for 258 cats, representing 83% of the cases. This study focused solely on these 258 cats. Respiratory causes accounted for 33% of cases, followed by cardiac causes (25%) and both traumatic and neoplastic causes (21% each). Pleural effusion was present in 39% of the cats, with various origins: cardiac (38%), respiratory (pyothorax, feline infectious peritonitis, 30%), neoplastic (23%), and traumatic (9%). Male cats were significantly overrepresented in the cardiac and respiratory groups. The median age differed according to the cause (2 years for traumatic causes, 6 years for respiratory causes, and approximately 11 years for cardiac and neoplastic causes). Cats with cardiac disease were significantly more often hypothermic. Hyperthermia was not systematically indicative of an infectious process. No clinical element (temperature, heart rate, cardiac auscultation, etc.) allowed for predicting the cause of dyspnea. In-hospital mortality was 44%, varying according to the cause (78% for neoplastic causes, 40% for traumatic causes, 37% for cardiac causes, and 30% for respiratory causes). In conclusion, the four main categories of causes were represented in approximately equal proportions, which contrasts with the results of the British RAPID CAT study, where cardiac causes accounted for nearly two-thirds of dyspnea cases. In the dyspneic cats in this series, the clinical presentation did not allow clinicians to identify a particular cause. This highlights the importance of non-invasive examinations such as POCUS (point-of-care ultrasound), which has become a routine test in emergency medicine. However, this importance should not lead to underestimating the continued value of radiography when the cat’s clinical condition allows for image acquisition
Methodological Development for Studying the Chemical Composition of Exhaust Particle Emissions: Application to a Passenger Vessel Operating on Marine Gas Oil
No full textInternational audienceOn-board emission measurements were conducted at the exhaust of a passenger ship operating under real-world conditions. The chemical composition of exhaust particulate emissions from a turbocharged four-stroke marine diesel engine, operated on Marine Gas Oil was studied. A variety of organic compounds, including alkanes, alkenes, alcohols, cycloalkanes, cycloalkenes, esters, ketones, carboxylic acids, etc., were analyzed. Alkanes were the most abundant organic compounds, followed by alkenes, esters, and alcohols. Emission factors for these compounds were determined under two operating conditions: low engine load (at berth at 400 rpm/4% load, and during port maneuvers at 800 rpm/14% load) and high engine load (during cruising at 1000 rpm, 68% load). A clear increase in organic-compound emission factors was observed at lower loads. The total particulate matter emission factors were between 0.02 and 0.03 g/kWh at high-load points and exhibited significant variability under low-load conditions, from 0.02 to 2.83 g/kWh. The effect of a marine fuel additive was evaluated in this study. Using this fuel additive resulted in a significant decrease in both particulate matter and organic-compound emission factors, especially at low engine loads. Furthermore, the marine fuel additive decreased the total emission factors (EF TOCs ) by a factor of 56 under low-load conditions. For high loads, the additive had no effect on the EF TOCs
La stérilisation des vaches de réforme, un levier dans la prévention des accidents locomoteurs : enquête auprès des éleveurs bovins laitiers et des vétérinaires ruraux
No full textLa problématique des traumatismes musculo-squelettiques en élevage bovin laitier est un phénomène bien connu mais peu étudié ; ils sont pourtant à l’origine de pertes économiques non négligeables pour les éleveurs et source de mortalité dans les élevages. Ces traumatismes peuvent être causés par les vaches en oestrus lors des chevauchements, cette étude cherche à vérifier l’hypothèse que les vaches de réforme qui évoluent au sein du troupeau laitier ont une part de responsabilité non négligeable dans l’occurrence des traumatismes musculo-squelettiques. L’ovariectomie serait une solution intéressante pour supprimer les comportements d’oestrus chez les vaches de réforme : cette étude s’intéresse également à l’opinion et aux connaissances des éleveurs concernant cette pratique, et fait un état des lieux de la pratique de l’ovariectomie des vaches laitières par les vétérinaires ruraux. Deux enquêtes ont été réalisées dans le cadre de cette étude : l’une auprès des éleveurs bovins laitiers, l’autre auprès des vétérinaires ruraux. Les résultats montrent que les deux parties ont pu constater la problématique des traumatismes musculo-squelettiques sur le terrain. Les vétérinaires comme les éleveurs pensent que la présence de vaches de réforme au sein du troupeau laitier augmente le risque d’accidents, et les vaches blessées sont généralement euthanasiées. L'ovariectomie est, aux yeux des deux parties, une solution intéressante pour supprimer les comportements d’oestrus chez les vaches de réforme. Les éleveurs ont cependant peu connaissance de cette pratique. D’un autre côté, les vétérinaires y sont peu formés et estiment que leur clientèle n’est pas demandeuse. Le principal frein à la démocratisation de la pratique de l’ovariectomie des vaches laitières de réforme semble être le manque de communication quant à cette pratique. L’immunocastration, une alternative non chirurgicale à l’ovariectomie, suscite également l’intérêt des éleveurs, par sa facilité de mise en œuvre et son moindre coût comparé à l’intervention chirurgicale, mais cette solution n’est à ce jour pas applicable en France. Les enquêtes menées montrent également que d’autres éléments peuvent être source de traumatismes musculo-squelettiques en élevage : sol glissant, carences nutritionnelles, etc. Cette problématique doit donc être abordée de manière holistique et peut mener à la réalisation d’un audit dans les élevages concernés. Concernant la pratique de l’ovariectomie des vaches laitières en France, elle a peu évolué depuis le dernier état des lieux réalisé en 2012 : elle est peu pratiquée, préférentiellement par abord vaginal, avec une ligature par un montage boulon-élastique, et la ponction du vagin peut se faire avec un panel varié d’instruments
Associations of maternal diet with nutritional and chemical exposure markers in human milk from the LACTACOL cohort of preterm infants
No full textInternational audienceMaternal diet may impact human milk composition. Our objective was to characterize the association between maternal diet and the presence of nutritional and chemical exposure markers of human milk in the context of prematurity. MethodsOne hundred and three mothers of preterm infants, recruited in the west of France near the Atlantic coast, completed a food frequency questionnaire to assess daily food intake. Milk was sampled up to discharge for analysis of Fatty Acids (FAs), Human Milk Oligosaccharides (HMOs) and Persistent Organic Pollutants (POPs). Four dietary patterns were identified by principal component analysis coupled with hierarchical clustering. The pattern "Snack Eater" with the highest n-6:n-3 ratio in terms of polyunsaturated FA intake showed the lowest levels of n-3 FAs (e.g., DocosaHexaenoic Acid (DHA), p=0.037) and POPs in milk. The highest level of dibenzodioxin was observed among the "Omnivores" pattern (p=0.027). Butter intake was associated with FAs in milk, mainly saturated (e.g., 15:0, =59.2, 95%CI [30.0-88.5]) and some POPs (e.g., PCB138, =53.3, 95%CI [10.9-95.6]), but not with HMO. Fish intake was associated with POPs in milk. Maternal diet may be associated with the FAs and POPs composition of milk in mothers of preterm infants, as it is for full-term infants. To improve the nutritional composition of human milk, it would be advisable to avoid the "Snack-eater" pattern and to favour the consumption of nutrient-rich foods. Butter consumption has been identified as a major contributor of pollutants and saturated fatty acids, 57 and should therefore be given particular attention. </div
miRNome Characterization of Milk-Derived Extracellular Vesicles in Recombinant Somatotropin-Treated Dairy Cows
No full textInternational audienceThe recombinant bovine somatotropin (rbST) is a synthetic hormone developed to mimic the effects of the endogenous growth hormone, also known as bovine somatotropin (bST). Although rbST use in dairy cows is authorized in several countries, it is currently banned in Europe. Different methods for screening and confirmatory detection of rbST were developed, mainly based on LC-MS/MS and immune-enzymatic assays. However, some commercial forms of rbST have above the same amino acid sequence of bST, making it difficult to produce a reliable differentiation of recombinant from endogenous forms. Complementary strategies for indirect detection of rbST can therefore be considered as alternative biomarker-based tools. Untargeted transcriptomics was applied to characterize the microRNAs (miRNA) isolated from milk extracellular vesicles (EVs) in rbST-treated animals, aiming the identification of non-coding biomarkers related to its administration. Sequencing analysis of 63 archive samples collected during previous animal trial allowed for the identification of 35 differentially expressed (DE) miRNAs. A validation study performed by qPCR on a further 70 milk samples from a field survey confirmed the significant upregulation of bta-miR-10167-3p in milk EV from rbST-treated cows. The results obtained suggest the potential use of bta-miR-10167-3p as a non-invasive biomarker to be considered in novel screening strategies, needed to tackle rbST misuse in dairy cows
CT scan-based morphometric comparison of human and canine lumbar spine generates instrumental data for intervertebral disc percutaneous surgery
No full textInternational audienceObjectiveThis study aimed to describe the anatomical landmarks for intervertebral disc (IVD) percutaneous approaches (transpedicular TPA and transannular TAA) using CT scans in humans and dogs for regenerative medicine research.MethodCT scans of 57 human (30 supine, 27 prone) and 49 canine (29 chondrodystrophic, 20 non-chondrodystrophic) lumbar spines were analyzed. Morphometric data, cutaneous landmarks, and approach angles were measured, with additional sections assessing nerve root distances from TPA routes.ResultsOver 15,000 measurements were taken, creating a comprehensive anatomical database. Significant differences in TPA and TAA angles were noted between humans and dogs (p < 0.0001).ConclusionThis study provides detailed anatomical landmarks for safe and effective IVD approaches, offering valuable guidance for translational research and surgical interventions
CFD simulation of isolated bubbles rising in Newtonian or non-Newtonian fluids inside a thin-gap bubble column
No full textInternational audienceHydrodynamics of the bubbling process can be complex especially in thin bubble columns, when the gap has the same order of magnitude as the bubble diameter, and with complex fluids. It is then important to understand this phenomenon either by experimental investigation through optical methods such as shadowgraphy and/or Particle Image Velocimetry (PIV) or numerically by Computational Fluid Dynamics (CFD), which, when validated, can allow numerical experimentation in situations which are expensive to implement experimentally or time consuming. In this study, three-dimensional numerical simulations of isolated bubbles rising in Newtonian (water) or non-Newtonian (CarboxyMethyl Cellulose (CMC) and Xanthan Gum (XG) solutions) liquid phases mimicking Chlorella vulgaris cultures at 42 g.L -1 concentration inside a 4 mm gap bubble column are performed using the volume of fluid (VOF) model with the ANSYS FLUENT 17.2 code. Results are validated by comparison with shadowgraphy experiments. Bubble terminal velocity, shape, and trajectory are numerically analysed. Wall shear stress (WSS) induced by the bubble, strain rate, viscosity and flow field around the bubble are also discussed. Numerical results show similar trends as experimental ones despite slightly lower terminal velocity and aspect ratio values are observed in comparison to the experimental results. The trajectory of the bubble is nonrectilinear for water and rectilinear for non-Newtonian fluids as observed experimentally. This numerical study highlights the bubble-liquid and bubble-wall interactions that will help to understand the complex phenomena of bubble rise in non-Newtonian media/microalgae suspensions at high concentrations at the local level in thin-gap bubble columns