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Characterizing optical behavior of automotive metal flake-pigmented coating systems using reflectance transformation imaging
No full textInternational audienceAbstract Metal flake-pigmented coatings are widely appreciated for their eye-catching appearance, and understanding their physical and optical properties is crucial for the automotive coatings industry. The metal flakes loaded in these coatings are optically anisotropic, with their sparkle change based on illumination and viewing angles. These tiny micro-mirrors exhibit various local angular reflections (LARn i ), and it is interesting to characterize their type-dependent optical behavior. In this study, we employed a reflectance transformation imaging (RTI) system to quantify the mean local angular reflectance (M-LARe) index of metal flakes in automotive metallic coatings. We first captured multi-light image collections (MLICs) from seven automotive metal flake-pigmented coatings, followed by a series of processing steps to extract the flakes’ LARn i . The extracted LARn i were then normalized, both radiometrically and geometrically, and used to compute the proposed type-dependent index, which is independent of the device and flake size and orientation. Finally, the M-LARe index histograms of the coatings were derived, and the seven samples were ranked according to their reflective capacity. We also observed a meaningful dependency between the mean value of the proposed M-LARe indices for each sample and its sparkle grade at 15°. Potential uncertainties, such as resin type, coating thickness, and metal flake count, were also acknowledged
Effect of Habitual Physical Activity on Strength Loss and Fatigability in Old and Very Old Men
No full textInternational audienceABSTRACT Age‐related neuromuscular and cardiovascular declines may increase relative effort and thus fatigability during daily activities. Habitual physical activity (PA) may mitigate these alterations. This study examined the effects of age and PA on fatiguability in ecological conditions. Thirty‐nine young men (YM, 22.1 ± 3.4 years), 34 old men (OM, 71.7 ± 4.1 years), and 23 very old men (VOM, 85.8 ± 2.7 years) performed a fatigue task. Increments were scaled in percentage body mass. Maximal knee extensor force (MVC), voluntary activation (VA), and twitch amplitude (Tw) were measured at baseline, after each stage and at task failure (TF). On a separate day, maximum oxygen consumption (V̇O 2 max) was quantified during a maximal ramp test. Results For a given workload (i.e., last common stage, LCS), MVC in percentage of baseline was lower in VOM (84.6% ± 9.2%) compared to YM (94.0% ± 7.0%; p < 0.001) and OM (91.7% ± 6.3%; p < 0.01). At LCS, Tw was lower in VOM (89.3% ± 12.7%) compared to OM (99.7% ± 10.5%; p < 0.05). MVC loss was greater in YM (−35.6% ± 14.5% of baseline) compared to VOM (−23.4% ± 11.3%; p < 0.01) at TF. No difference was found between YM and OM for loss in MVC and Tw. PA level was correlated with V̇O 2 max but did not affect fatigability. Tw loss at LCS was correlated with V̇O 2 max in VOM ( r = 0.69; p < 0.05). VOM, but not OM, was more fatigued than YM for a given submaximal workload but the opposite was true at exhaustion. Fatigability in VOM was due to peripheral factors and was correlated with aerobic capacity. In VOM, unlike YM and OM, higher PA levels may be sufficient to improve aerobic capacity and reduce fatigability. Trial Registration: ClinicalTrials.gov identifier: NCT0541359
Une question de taille - Regards croisés sur un geste viticole en Bourgogne
No full textInternational audienc
Evaluating the effects of environmental disturbances and pesticide mixtures on N-cycle related soil microbial endpoints
No full textInternational audiencePesticides are widely used in conventional agriculture, either applied separately or incombination during the culture cycle. Due to their occurrence and persistence in soils, pesticideresidues may have an impact on soil microbial communities and on supported ecosystemservices. In this regard, the EFSA (European Food Safety Authority) recently published ascientific opinion inciting to change pesticide risk assessment to better protect soil microbe-mediated processes. Climate change is another major concern for all living organisms includingsoil microbial community stability. Extreme climatic events, such as heat waves or heavyrainfalls, are becoming more and more frequent and their impact on soil microbial diversity andfunctions have already been demonstrated.The objectives of this study were to evaluate the effects of temperature and humiditydisturbances and pesticide active ingredients exposure on soil microbial community structureand functions. To this end, 250 soil microcosms were exposed to either a heat disturbance, ahigh humidity to mimic heavy rain, or no environmental disturbance. After three days ofrecovery, soil microcosms were treated with different active ingredients: clopyralid (herbicide),cypermethrin (insecticide) and pyraclostrobin (fungicide). The treatments were applied aloneor in combination at 1x or 10x of the agronomical dose. We then evaluated the effects of thedisturbances and the active ingredients on various microbial endpoints related to the diversityand the structure of soil microbial communities, and with a specific focus on microbial guildsinvolved in nitrification.Overall, we demonstrated that the impact of environmental disturbances applied to soilmicrocosms, especially heat, on microbial endpoints was stronger than that of the activeingredients applied alone or in combinations. Compounded effects of environmentaldisturbances and active ingredients were detected, but sparsely and were of small scale for thechosen pesticides and applied doses
Efficience du transport de phosphate au niveau de l’interface symbiotique racinaire
No full textNational audienc
Metabolic Reprogramming for Body Adaptation and Inflammatory Control in Eccentric Damaging Exercise: Comprehensive Molecular Insights From Repeated Downhill Running
No full textInternational audienc
Farm demonstration networks as learning environments
No full textInternational audienceFarm Demonstration Networks are peer advisory farmer groups set up with the aim of sharing knowledge about sustainable farming practices. Within the current study a "Learning Environment" framework is developed based on literature review to investigate and improve the setup, organization, and facilitation of such networks. The framework also functions as a structure for evaluation of both the educational process and impact of such networks. Four interlinked dimensions are proposed within the framework: learning objectives, instruction, physical learning space, and socio-cultural context. An exploration of the framework was done via 21 interviews with existing networks in Europe. This led to structural improvements and inspiration for the learning design of future Farm Demonstration Networks
Repenser la régulation transactionnelle dans les environnements C2C : une approche expérientielle de la théorie des coûts de transaction
No full textNational audienc
Approches clinique et expérimentale des réponses Immune et Métabolique de l’hôte au cours des pneumonies sévères
No full textVentilator-associated pneumonia (VAP) is common in critical care settings and is associated with metabolic and immune dysfunctions. It leads to prolonged stays in intensive care units and represents a major cause of morbidity and mortality. Mesenchymal stromal cells (MSCs) have demonstrated their ability to enhance bacterial clearance and attenuate inflammatory responses in preclinical models of pneumonia. Due to their functional plasticity, they may also correct certain immune dysfunctions depending on the inflammatory environment. Thus, MSCs represent a promising therapeutic approach to restoring immune and metabolic homeostasis in VAP. The objective of this study was to evaluate whether the administration of human umbilical cord-derived MSCs could improve clinical outcomes and correct immune and metabolic dysfunctions in a rabbit model of Enterobacter-induced VAP. When administered alone, MSCs did not improve survival, bacterial clearance, or the resolution of pulmonary immune alterations. No significant systemic effects were observed. However, when combined with antibiotic therapy, MSCs administration reduced pulmonary inflammation, improved bacterial clearance in the lungs, and marginally increased survival. MSCs injection had no significant effect on the ex vivo whole-blood response to LPS stimulation. These results suggest a synergistic effect between MSCs and antibiotics, consistent with previous findings in our pneumococcal pneumonia model. This work paves the way for the REPROCELL project, which will investigate the ex vivo effects of MSCs on the reprogramming of immune cells in critically ill patients with severe pneumonia.Les pneumonies acquises sous ventilation mécanique (PAVM) sont fréquentes en soins critiques et associées à des dysfonctions métaboliques et immunitaires. Elles entraînent des séjours prolongés en réanimation et constituent une cause majeure de morbi-mortalité. Les cellules stromales mésenchymateuses (CSM) ont démontré, dans des modèles précliniques de pneumonie, leur capacité à améliorer la clairance bactérienne et à atténuer la réponse inflammatoire. Grâce à leur plasticité fonctionnelle, elles pourraient également corriger certaines dysfonctions immunitaires en fonction du contexte inflammatoire dans lequel elles se trouvent. Ainsi, elles représentent une approche thérapeutique prometteuse pour restaurer l’homéostasie immunitaire et métabolique au cours de la PAVM. L’objectif de cette étude était d’évaluer si l’administration de CSM humaines issues du cordon ombilical pouvait améliorer l’évolution clinique et corriger les dysfonctions immunitaires et métaboliques dans un modèle de PAVM à Enterobacter chez le lapin. Administrées seules, les CSM n’amélioraient ni la survie, ni la clairance bactérienne, ni la résolution des altérations immunitaires pulmonaires. Aucun effet systémique significatif n’a été observé. En revanche, en association avec une antibiothérapie, les CSM réduisaient l’inflammation pulmonaire, amélioraient la clairance bactérienne pulmonaire et, de manière marginale, la survie. L’injection de CSM n’avait pas d’effet significatif sur la réponse ex vivo du sang total à une stimulation par le LPS. Ces résultats suggèrent un effet synergique entre les CSM et l’antibiothérapie, en accord avec les observations précédemment rapportées dans notre modèle de pneumonie à pneumocoque. Ce travail ouvre la voie au projet REPROCELL, qui évaluera l’effet ex vivo des CSM sur la reprogrammation des cellules immunitaires de patients atteints de pneumonie grave en soins critiques