Non destructive investigation of defects in composite structures by three infrared thermographic techniques

This paper investigates full-field measurement techniques based on Infrared Thermography for Non Destructive Testing (NDT) applications on composite materials. Three methods have been implemented and the paper intends to characterize and compare their defect detection limit and related specific application fields. Various composites have been considered in this study, namely laminates and sandwich structures, in order to address many important issues of performance assessment for the aviation industry

Non destructive investigation of defects in composite structures by fullfield measurement methods

This paper presents different interests of non destructive full-field measurement. More precisely, it focuses on the characterization and the comparison of the X-ray tomography and two methods of infrared thermography in order to define the defect detection limits and to precise the specific application fields for each technique on multi-layered and sandwich composite structures. The obtained results are qualitatively and quantitatively analyzed

AN AUTOMATIC SYSTEM FOR THE ANALYSIS OF INTERCELLULAR COMMUNICATION AND EARLY CARCINOGENESIS

International audienceSome recent works on intercellular communication pointed out an impaired trafficking of Cx43 proteins in early carcinogenesis. In collaboration with biologists, we propose an automatic system for the analysis of spatial protein configurations within cells at early tumor stages. This system is an essential step towards the future development of a computer-aided diagnosis tool and the statistical validation of biological hypotheses about Cx43 expressions and configurations during tumorogenesis. The proposed system contains two dependent part: a segmentation part in which the cell structures of interest are automatically located on images and a characterization part in which some spatial features are computed for the classification of cells. Using immunofluorescent images of cells, the nucleus, cytoplasm and proteins structures within the cell are extracted. Then, some spatial features are computed to characterize spatial configurations of the proteins with regard to the nucleus and cytoplasm areas in the image. Last, the 3D cell images are classified into pathogenic or viable classes. The system has been quantitatively evaluated over 60 cell images acquired by a deconvolution high-resolution microscope and whose ground truth has been manually given by a biologist expert. As a perspective, a 3D spatial reasoning and visualization module is currently under development

Non destructive testing of artificial defects in composite structures by thermal full field measurement methods

In order to achieve outstanding performance, it now seeks to optimize more and more the design and process of composite structures. Many applications require specific technical inspections at various steps of the product lifetime to assess their structural health. In such a context, non destructive techniques (NDT) offer an interesting and appropriated tool for the analysis of structural parts. For aviation industry, the AITM standards are precisely based on the NDT ultrasonic testing for the validation of composite structures. Since recent years, the use of full-field measurement NDT as infrared (IR) thermography is developing for their fast execution and analysis (defect mapping in one shot) and for the global inspection aspect. This work consists in characterizing and in comparing three thermal full-field measurement NDT in order to define the defect detection limits, the advantages and the limitations for each technique on multi-layered and sandwich composite structures

Evaluation morphométrique et échographique de la croissance du chiot au cours des deux premiers mois de vie

Du fait du manque d’images de référence, l’interprétation des images échographiques chez le chiot est encore difficile. L’objectif de notre étude était ainsi de déterminer l’aspect et les dimensions normales des organes abdominaux ainsi que les paramètres morphométriques en fonction de l’âge chez le chiot en bonne santé. Des examens échographiques abdominaux ont été réalisés chez 50 chiots sains, de race Berger de Beauce, suivis régulièrement entre 2 et 56 jours d’âge. La longueur moyenne du rein gauche en coupe sagittale variait de 2,52(±1,2) cm à 2 jours d’âge à 5,71(±0,42) cm à 56 jours d’âge. La surface moyenne du lobe hépatique variait de 5,39(±0,85) cm2 à 2 jours d’âge à 26,13(±2,94) cm2 à 56 jours d’âge. La longueur moyenne du rein droit était significativement plus grande que celle du rein gauche chez 74 à 92 % des chiots selon l’âge. Les chiots à petit poids de naissance avaient un volume rénal et une surface hépatique proportionnellement plus faibles que les chiots nés avec un poids normal, respectivement jusqu’à une et deux semaines d’âge. À partir de 35 jours d’âge, les paramètres morphométriques et les dimensions du rein droit des mâles étaient plus élevés que ceux des femelles. À deux jours d’âge, la présence d’épanchement abdominal et de dilatation pyélique rénale a été mise en évidence chez respectivement 60% et 40% des chiots puis leur prévalence diminuait. Au cours du deuxième mois de vie, le parenchyme splénique présentait un aspect hétérogène, « léopardé », les noeuds lymphatiques étaient particulièrement développés et la structure en couches de la paroi digestive devenait visible. Cette étude fournit un guide pratique sur les dimensions normales des organes abdominaux chez le chiot au cours des deux premiers mois de vie et pourrait ainsi servir de référence préliminaire dans la pratique quotidienn

0292: Endothelial protein tyrosine phosphatase 1B deficiency reduces both endothelial and cardiac dysfunction of in a mouse model of aging

IntroductionAging is associated with an endothelial dysfunction, characterized by a decrease of nitric oxide (NO) production, which is a risk factor of development of cardiovascular diseases. However, the direct link between endothelial dysfunction and aggravation of cardiac function in aging is not established. We reported previously a new potent therapeutic approach of cardiovascular disease, based on inhibition of protein tyrosine phosphatase 1B (PTP1B), which both increases NO production (via restored PI3K/Akt/eNOS signaling) and reduces cardiac dysfunction in both post-ischemic heart failure and aging, however the exact role of endothelial PTP1B in this setting is unknown. To evaluate the endothelial and cardiac consequences of endothelial PTP1B deficiency (endoPTP1B-/-) in a mouse model of aging.Material and methodsEndoPTP1B-/- mice were developed by crossing LOX-P PTP1B mice with mice expressing CRE under the control of the endothelial promoter Tie2, or wild-type (WT). The evolution of cardiac function was assessed by echocardiography at different time points and the vascular function was evaluated ex vivo at 24 months.ResultsCompared to young (3 month-old), WT mice aged (24 month-old) showed a markedly impaired flow-mediated dilatation of isolated mesenteric arteries (3 months: 40±4%; 24 months: 1±1%; p<0.001), which was improved in endoPTP1B-/- mice (17±3%; p<0.001 vs. WT 24 months). This restored response in aged endoPTP1B-/- mice was abolished by a NO-synthase inhibitor, suggesting a restored NO production. In WT mice, aging decreased stroke volume (3 months: 0,070±0,002%; 24 months: 0,065±0,005%; p<0.001) and cardiac output (3 months: 37±1%; 24 months: 29±2%; p<0.001) and these parameters were improved in endoPTP1B-/- mice (24 months: 0.081±0,011% and 34±2%; respectively, p<0.05).ConclusionIn aged mice, endoPTP1B deficiency induced an improvement of endothelial function, and also tended to improved cardiac function. These results provide a direct demonstration of the beneficial effect of endothelial protection in aging

Draft Genome Sequences of Six Ruminant Coxiella burnetii Isolates of European Origin

Coxiella burnetii is responsible for Q fever, a worldwide zoonosis attributed to the inhalation of aerosols contaminated by livestock birth products. Six draft genome sequences of European C. burnetii isolates from ruminants are presented here. The availability of these genomes will help in understanding the potential host specificity and pathogenicity and in identifying pertinent markers for surveillance and tracing

Conditions for the success and the feasibility of health mediation for healthcare use by underserved populations: a scoping review

OBJECTIVE: This article aims to analyse the conditions under which health mediation for healthcare use is successful and feasible for underserved populations. METHOD: We conducted a scoping review on the conditions for effective health mediation according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews standards. We searched for articles in the following databases: PubMed, PsychINFO, Scopus and Cairn published between 1 January 2015 and 18 December 2020. We selected the articles concerning health mediation interventions or similar, implemented in high-income countries and conducted among underserved populations, along with articles that questioned their effectiveness conditions. We created a two-dimensional analysis grid of the data collected: a descriptive dimension of the intervention and an analytical dimension of the conditions for the success and feasability of health mediation. RESULTS: 22 articles were selected and analysed. The scoping review underlines many health mediation characteristics that articulate education and healthcare system navigation actions, along with mobilisation, engagement, and collaboration of local actors among themselves and with the populations. The conditions for the success and the feasability were grouped in a conceptual framework of health mediation. CONCLUSION: The scoping review allows us to establish an initial framework for analysing the conditions for the success and the feasability of health mediation and to question the consistency of the health mediation approach regarding cross-cutting tensions and occasionally divergent logic

Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection Unit

High-dispersion coronagraphy (HDC) optimally combines high contrast imaging techniques such as adaptive optics/wavefront control plus coronagraphy to high spectral resolution spectroscopy. HDC is a critical pathway towards fully characterizing exoplanet atmospheres across a broad range of masses from giant gaseous planets down to Earth-like planets. In addition to determining the molecular composition of exoplanet atmospheres, HDC also enables Doppler mapping of atmosphere inhomogeneities (temperature, clouds, wind), as well as precise measurements of exoplanet rotational velocities. Here, we demonstrate an innovative concept for injecting the directly-imaged planet light into a single-mode fiber, linking a high-contrast adaptively-corrected coronagraph to a high-resolution spectrograph (diffraction-limited or not). Our laboratory demonstration includes three key milestones: close-to-theoretical injection efficiency, accurate pointing and tracking, on-fiber coherent modulation and speckle nulling of spurious starlight signal coupling into the fiber. Using the extreme modal selectivity of single-mode fibers, we also demonstrated speckle suppression gains that outperform conventional image-based speckle nulling by at least two orders of magnitude.Comment: 10 pages, 7 figures, accepted by Ap