Portail des publications scientifiques IMT Mines Alès
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Determinants of physical activity in newly diagnosed obstructive sleep apnea patients: testing the health action process approach
No full textInternational audienceThis study aims to identify the determinants associated with physical activity (PA) behavior in newly diagnosed obstructive sleep apnea (OSA) patients by applying the Health Action Process Approach (HAPA) with a longitudinal design. Anthropometric and clinical (OSA severity, subjective somnolence, use of continuous positive airway pressure (CPAP)) variables, the determinants of physical activity specified in the HAPA (motivational self-efficacy, outcome expectancies, risk perception, intention, maintenance self-efficacy, action planning, coping planning, social support), as well as physical activity behavior were assessed using a longitudinal (T1 and T2) design in a sample of 57 OSA patients in routine care. Applying regression analyses, regarding the motivation phase, the amount of explained variance in intention was 77% and 39% of the variance in physical activity. In the motivational phase, motivational self-efficacy, risk perception and outcome expectancies were associated with intention. In the volitional phase, physical activity at T1 and social support (family) were related with physical activity at T2. In conclusion, the assumptions of HAPA were partially found in the context of newly diagnosed OSA patients. This study provided additional evidence regarding the role of motivational self-efficacy, outcome expectancies and risk perception during motivational phase, and highlighted the important role of social support from the family in the PA in this population
Prédiction de réponse au 177Lu-PSMA dans le cancer prostatique métastatique résistant, via l’apprentissage automatique
No full textInternational audienceCette étude explore les facteurs prédictifs de la réponse au traitement par radioligands (RLT) avec [177Lu] Lu-PSMA dans le traitement du cancer de la prostate métastatique résistant à la castration (mCRPC). Nous avons divisé, selon des critères clinicobiologiques, nos premiers patients traités en deux classes : répondeurs et non répondeurs à la RLT par Lu-PSMA. En utilisant un ensemble de données comprenant des paramètres d’imagerie (TEP 18F-Choline, 68Ga-PSMA et FDG) et des paramètres biologiques, nous avons cherché des éléments prédictifs de la réponse au traitement. L’analyse, basée sur l’analyse exploratoire des données et l’ingénierie des caractéristiques, souligne l’importance des caractéristiques d’imagerie dans la prédiction de l’efficacité du traitement. En outre, des modèles d’apprentissage automatique ont été développés pour prédire les résultats des patients. Sur les données d’imagerie, nos résultats suggèrent une différence statistiquement significative dans l’intensité de la fixation rénale de la choline entre les deux groupes et une fixation ganglionnaire métastatique plus élevée du PSMA chez les répondeurs. De plus, une discordance de fixation FDG+ et PSMA- est apparue comme un indicateur potentiel de non-réponse. En intégrant les données biologiques, le modèle obtient un Recall élevé de 0,92 et une AUC de 0,83, soulignant son potentiel de prédiction de la réponse (le recall mesure la capacité d’un modèle à identifier tous les cas positifs tandis que l’AUC – ou l’aire sous la courbe – mesure la performance d’un modèle de classification). Ces observations soulignent l’importance de l’intégration des données d’imagerie aux données biologiques pour améliorer la précision prédictive des résultats pour les patients dans la RLT avec [177Lu] Lu-PSMA. Non seulement cette étude nous permet d’approfondir notre compréhension des facteurs prédictifs affectant l’efficacité de la RLT, mais elle met également en évidence la valeur de l’apprentissage automatique dans l’amélioration du processus de sélection des patients en vue d’une planification optimisée du traitement
Hybrid FEM/DEM modelling of a stone wall in a fire-like situation
No full textInternational audienceUntil the 19th century, masonry was the preferred long-term construction method. Today, questions about the conservation of old buildings and their serviceability in post-fire situations remain unanswered. The fire at Notre-Dame de Paris Cathedral in 2019 makes this a particularly topical issue. It was the occasion to develop a new numerical approach for structural analysis of masonry, combining FEM and DEM approaches. The Finite Element Method (FEM) makes it possible to consider pre-peak and post-peak mechanical properties of the material. The Discrete Element Method (DEM) allows the behaviour of the joints to be modelled accurately. These two numerical approaches have been combined in a "hybrid" model using the LMGC90 (DEM) and CAST3M (FEM) codes. The aim of the study presented here is to test the hybrid model under a fire-like thermal loading. An assembly of two blocks joined by mortar was first studied. Then, experimental data from the literature were used to validate the model on a real case. These experimental tests consisted of heating one side of a 3x3 m² wall with a standard ISO 834 fire, while the other side was exposed to ambient temperature. The materials used in these tests were similar to those used in the Notre-Dame de Paris Cathedral: Lutetian limestone and hydraulic lime mortar. The results are used to improve the hybrid model and its application with a view to the calculation of Notre-Dame de Paris Cathedral post-fire stability
Experimental and Numerical Analysis of a PCM-Integrated Roof for Higher Thermal Performance of Buildings
No full textInternational audiencePhase change materials (PCMs) designate materials able to store latent heat. PCMs change state from solid to liquid over a defined temperature range. This process is reversible and can be used for thermo-technical purposes. The present paper aims to study the thermal performance of an inorganic eutectic PCM integrated into the rooftop slab of a test room and analyze its potential for building thermal management. The experiment is conducted in two test rooms in Antofagasta (Chile) during summer, fall, and winter. The PCM is integrated into the rooftop of the first test room, while the roof panel of the second room is a sealed air cavity. The work introduces a numerical model, which is built using the finite difference method and used to simulate the rooms’ thermal behavior. Several thermal simulations of the PCM room are performed for other Chilean locations to evaluate and compare the capability of the PCM panel to store latent heat thermal energy in different climates. Results show that the indoor temperature of the PCM room in Antofagasta varies only 21.1°C±10.6°C, while the one of the air-panel room varies 28.3°C±18.5°C. Under the experiment’s conditions, the PCM room’s indoor temperature observes smoother diurnal fluctuations, with lower maximum and higher minimum indoor temperatures than that of the air-panel room. Thermal simulations in other cities show that the PCM panel has a better thermal performance during winter, as it helps to maintain or increase the room temperature by some degrees to reach comfort temperatures. This demonstrates that the implementation of such PCM in the building envelope can effectively reduce space heating and cooling needs, and improve indoor thermal comfort in different climates of Chile
Comparison of Untargeted and Markers Analysis of Volatile Organic Compounds with SIFT-MS and SPME-GC-MS to Assess Tea Traceability
No full textInternational audienceTea is one of the most consumed beverages in the world and presents a great aromatic diversity depending on the origin of the production and the transformation process. Volatile organic compounds (VOCs) greatly contribute to the sensory perception of tea and are excellent markers for traceability and quality. In this work, we analyzed the volatile organic compounds (VOCs) emitted by twenty-six perfectly traced samples of tea with two analytical techniques and two data treatment strategies. First, we performed headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) as the most widely used reference method for sanitary and quality controls of food. Next, we analyzed the samples with selected-ion flow-tube mass spectrometry (SIFT-MS), an emerging method for direct analysis of food products and aroma. We compared the performances of both techniques to trace the origin and the transformation processes. We selected the forty-eight most relevant markers with HS-SPME-GC-MS and evaluated their concentrations with a flame ionization detector (FID) on the same instrument. This set of markers permitted separation of the origins of samples but did not allow the samples to be differentiated based on the color. The same set of markers was measured with SIFT-MS instrument without success for either origin separation or color differentiation. Finally, a post-processing treatment of raw data signals with an untargeted approach was applied to the GC-MS and SIFT-MS dataset. This strategy allowed a good discrimination of origin and color with both instruments. Advantages and drawbacks of volatile profiles with both instruments were discussed for the traceability and quality assessment of food
Apports des arbres de régression dans l’analyse douce des fluctuations redressées (soft DFA)
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Communautés féministes et queer sur Instagram en France : l’entre-soi nécessaire
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Green Solutions for Wastewater Reclamation: Harnessing Trichoderma Bioinoculants for Micropollutant Removal in Constructed Wetlands and Agricultural Soils
No full textNational audienceUtilizing wastewater irrigation in agricultural practices offers the dual benefit of reducing water consumption while enriching soils with nutrients. However, this practice also presents inherent risks due to the presence of emerging contaminants. Moreover, the formation of potentially hazardous transformation products within the soil and rhizosphere, which may subsequently be absorbed by plants, further exacerbates concerns.Constructed wetlands are nature-based solutions (NBS) that can effectively provide treated wastewater for irrigation with varying nutrient contents to meet the specific requirements of different crops, thereby promoting sustainable agricultural practices. However, micropollutants are often not completely removed. Intensification of CWs with continuous or intermittent active aeration has been successfully implemented at the expense of higher capital and operational costs. In this context, bioaugmentation emerges as a promising strategy to enhance wetland treatment efficacy, leveraging the natural mycorrhization in wetlands and the pivotal role of bacteria in contaminant degradation processes.Here, we present the results of our studies using commercially available products containing spores of symbiotic fungi for enhancing the biodegradation of micropollutants in agricultural soils irrigated with treated wastewater. Two different strains belonging to Trichoderma genus were used as bioinoculants in CWs for wastewater treatment and directly in agricultural soils irrigated with wastewater.Trichoderma asperellum (strain T34) was tested for the removal of contaminants of emerging concern (CECs) and antibiotic resistance genes (ARGs) in a pilot-scale partially saturated vertical flow constructed wetland. The pilot was located outdoors at the facilities of the experimental platform for wastewater reuse in irrigation in Murviel-Lès-Montpellier (Southern France). The system was operated as tertiary treatment and was fed with real secondary treated domestic wastewater obtained by an aerated CW with a nominal treatment capacity of 3000 Inhabitant Equivalent and with additional treatment for phosphorus removal by precipitation with ferric chloride. Advanced methodologies including nontarget liquid chromatography high-resolution mass spectrometry and SmartChip™ Real-Time PCR were employed. Successful bioaugmentation was achieved, with Trichoderma exhibiting growth in competitive conditions using secondary treated domestic wastewater. Removal efficiency (RE) showed a clear correlation with compound biodegradability and sorption capacity, with easily biodegradable compounds showing higher elimination rates. Compounds with optimal plant uptake demonstrated significant removal efficiency. Notably, benzotriazole and diclofenac showed the mostbeneficial effects. Polar compounds like melamine proved most challenging to eliminate. However, high variability in removal efficiency over the experiment's duration limited treatment performance assessment. Transformation products (TPs), including N-oxide TPs and 14-hydroxyclarithromycin, were identified, with some undergoing partial elimination. Bioaugmented treatments led to a shift in ARG composition, though average removal rates remained statistically unchanged.In a second study, we explored the impact of the fungus Trichoderma harzianum on the distribution of two emerging contaminants, carbamazepine and climbazole, and their primary transformation products (TPs) in soils and lettuce tissues under controlled conditions. Physiological effects are examined by quantifying phytohormones in roots and leaves. While inoculation with Trichoderma harzianum did not notably influence the uptake of parent compounds, it did elevate TP concentrations in soil while reducing them in plant leaves after three weeks. Fungal inoculation also led to improved biomass and altered levels of certain phytohormones implicated in defense mechanisms and microbiome recruitment in roots and soils.Our findings offer valuable insights applicable to sustainable NBS-based wastewater treatment and crop cultivation, particularly in the context of reclaimed wastewater irrigation, leveraging accessible biological products for enhanced management practices
Comparison of clinical characteristics between responders and non-responders to hamstring stretching in individuals with chronic low back pain
No full textInternational audienceBackground/Objectives: Hamstring muscle (HM) flexibility is frequently compromised in people with chronic low back pain (CLBP), contributing to disability and leading to a less favorable recovery. In a previous article, we presented the results of a study on the immediate effect of passive HM stretching on flexibility in 90 people with CLBP. There was considerable variability in the changes after stretching. The objective of this supplementary analysis was to compare the clinical characteristics of individuals who experienced a significant improvement in flexibility with those who did not. Methods: We fixed a threshold of 7 • to indicate an improvement in passive Straight Leg Raise (SLR) angle and differentiate between 'Responders' and 'Non-responders' regarding passive HM stretching. Results: Only body mass index differed between groups; it was significantly smaller in Responders (p = 0.007). The majority of Non-responders experienced workplace accidents, but this was of marginal difference compared to Responders (p = 0.056). Conclusions: Further studies should consider a broader clinical analysis with a larger sample size to understand which factors influence the HM stretching response in CLBP patients