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Analyzing B Corp Certification: Opportunities and Complexities in Addressing Grand Challenges
No full textInternational audienceAs global crises intensify, businesses face increasing pressure to align their commercial activities with societal and environmental objectives. Among the array of third-party standards aimed at assessing corporate responsibility, the Certified B Corporation label has emerged as a prominent framework, guided by its mission to "Make business a force for good". However, research has extensively studied why companies would engage in this process, much less how the assessment content is related to solving current Grand Challenges. This paper compares the content of an assessment questionnaire to the expectations outlined in literature about how companies should address Grand Societal challenges. We show that while being comprehensive on the ESG agenda, the B Impact Assessment tends to give limited attention to the interdependent and unknown nature of Grand Challenges, thus creating the risk of focusing firms' attention on known visible impacts instead of addressing the complexity of current crises. We then conclude on complementary mechanisms that can significantly improve the contribution of certification labels to making businesses a "force for good"
A relativistic continuous matrix product state study of field theories with defects
No full textInternational audienceWe propose a method to compute expectation values in 1+1-dimensional massive Quantum Field Theories (QFTs) with line defects using Relativistic Continuous Matrix Product State (RCMPS). Exploiting Euclidean invariance, we use a quantization scheme where (imaginary) time runs perpendicularly to the defect. With this choice, correlation functions of local operators in the presence of the defect can be computed as expectation values of extended operators in the no-defect vacuum, which can be approximated by a homogeneous RCMPS. We demonstrate the effectiveness of this machinery by computing correlation functions of local bulk and defect operators in theory with a magnetic line defect, in perturbative, strong coupling, critical, and symmetry-broken regimes
Hybrid fault diagnosis method for underwater thrusters based on the common features of multi-source signals
No full textInternational audienceIntegrating the motor and driver into the confined space of an underwater thruster's sealed shell can lead to current sensor failures, primarily due to high temperatures, pressures, and electromagnetic interference. Despite progress in distinguishing sensor malfunctions from propeller issues, a significant gap exists in understanding simultaneous sensor and propeller failures. This study addresses this by thoroughly analyzing the propeller's condition during sensor failure. We introduce two virtual sensors, ingeniously derived from the motor's voltage and mechanical model, to estimate the thruster's current from different perspectives and effectively separate sensor and propeller faults. Recognizing the potential discrepancies between the virtual and real sensors, we developed a multi-source signal common features extractor inspired by transfer learning. This extractor obtains common features from measured and estimated currents, leveraging these variations to detect and assess faults accurately. The effectiveness of this approach has been corroborated through simulation and experiment, demonstrating the ability to distinguish between sensor and propeller faults and accurately evaluate the system's status
sCellST: a Multiple Instance Learning approach to predict single-cell gene expression from H&E images using spatial transcriptomics
No full textAbstract Advancing our understanding of tissue organization and its disruptions in disease remains a key focus in biomedical research. Histological slides stained with Hematoxylin and Eosin (H&E) provide an abundant source of morphological information, while Spatial Transcriptomics (ST) enables detailed, spatiallyresolved gene expression (GE) analysis, though at a high cost and with limited clinical accessibility. Predicting GE directly from H&E images using ST as a reference has thus become an attractive objective; however, current patch-based approaches lack single-cell resolution. Here, we present sCellST, a multipleinstance learning model that predicts GE by leveraging cell morphology alone, achieving remarkable predictive accuracy. When tested on a pancreatic ductal adenocarcinoma dataset, sCellST outperformed traditional methods, underscoring the value of basing predictions on single-cell images rather than tissue patches. Additionally, we demonstrate that sCellST can detect subtle morphological differences among cell types by utilizing marker genes in ovarian cancer samples. Our findings suggest that this approach could enable single-cell level GE predictions across large cohorts of H&E-stained slides, providing an innovative means to valorize this abundant resource in biomedical research
On the emergence of fault afterslip during laboratory seismic cycles
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La série de science-fiction au service de l’organisation. Le cas du programme Red Team Défense du ministère des Armées français
No full textChapitre 14Peut-on faire de la recherche scientifique sur les liens entre séries télévisées et management ? C'est le pari de cet ouvrage, adossé à la première édition (« saison », forcément !) du colloque Management en Séries qui s'est déroulé à l'université Gustave Eiffel en mars 2023.Il se déploie dans trois directions complémentaires : en examinant comment les séries télévisées peuvent nous aider à déconstruire les pratiques de management, en développant des méthodes pédagogiques visant à stimuler la réflexivité des étudiants et en proposant des réflexions sur les liens entre réalités du management et fictions télévisuellesVous qui tenez cet ouvrage entre vos mains, peut-être est-ce parce que vous êtes vous-même un gros consommateur de séries TV... voire un "binge-watcher" ? Rassurez-vous : en lisant ce livre, vous n'en serez que plus décomplexé, car son ambition est de montrer en quoi les séries TV sont plus que de simples fictions ou divertissements, qu'elles nous parlent de nos vies professionnelles et en particulier du management contemporain et de pratiques... que la recherche en sciences sociales peut saisir et inviter à dépasser. "Peut-on faire de la recherche scientifique sur les liens entre séries TV et management ? " Tenter de répondre à cette question, c'est le pari de cet ouvrage, adossé à la première édition ("saison", forcément ! ) du colloque Management en séries qui s'est déroulé à l'université Gustave Eiffel en mars 2023. Les contributions des auteurs vous proposeront d'examiner comment les séries TV peuvent nous aider à déconstruire les pratiques managériales, ou encore comment mobiliser ces séries pour mieux enseigner le management et stimuler la réflexivité des étudiants.Enfin, l'ouvrage propose de mettre en miroir la réalité du management avec celle représentée dans les fictions sérielles. En somme, déculpabilisez-vous de votre consommation de séries, tout en lisant un livre : LEGENDARY
Quantifying Damage Mechanisms Through FE-based Void Tracking: Application to Shear and Tension In-situ Laminography Experiments on AA2198-T851
No full textInternational audienceThis study presents a hybrid experimental-numerical postprocessing technique for analyzing damage evolution during in-situ tomography experiments. Using the displacement fields obtained from finite-element (FE) simulations as initial guesses, voids are tracked throughout loading by mapping their centroids to the initial configuration with a novel void tracking algorithm. This algorithm facilitates differentiation between void nucleation, growth and/or coalescence of existing voids. In-situ laminography experiments are performed on flat shear, central-hole tension, notched tension and compact tension specimens extracted from recrystallized aluminum alloy 2198-T851. The specimens are monotonically loaded all the way to fracture to gain insight into ductile failure mechanisms for predominantly biaxial stress states. Detailed 3D gray scale images are acquired at multiple stages of each experiment, allowing distinguishing between polycrystalline matrix, inter-metallic particles and voids at sub-micrometer resolution. The postprocessing of all experiments leads to a wealth of experimental data on void sizes, shapes, counts, volume fractions, and mechanisms of origin. Average stress states and macroscopic strain estimates are derived using continuum scale FE simulations with an anisotropic non-porous plasticity model and related to the void evolution. The tomographic observations show two primary damage mechanisms at early plastic straining stages: (1) intermetallic particle cracking and debonding, and (2) micro-crack emergence mainly at grain boundaries. At high plastic straining stages, grain boundary unzipping leads to fracture via micro-crack growth and coalescence, more prevalent under generalized shear than tension. It is found that particle-related void growth is slow and enhances the material's macroscopic ductility by delaying the growth of large void
Parametric Shape Optimization of Flagellated Micro-Swimmers Using Bayesian Techniques
No full textInternational audienceUnderstanding and optimizing the design of helical micro-swimmers is crucial for advancing their application in various fields. This study presents an innovative approach combining Free-Form Deformation with Bayesian Optimization to enhance the shape of these swimmers. Our method facilitates the computation of generic swimmer shapes that achieve optimal average speed and efficiency. Applied to both monoflagellated and biflagellated swimmers, our optimization framework has led to the identification of new optimal shapes. These shapes are compared with biological counterparts, highlighting a diverse range of swimmers, including both pushers and pullers
Local measurement on oedometric compression tests: Time and temperature ageing effects on a fluorosilicone
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Strontium (Sr) signal in the Mesozoic Southeastern French Basin (Alps) and its relation with pre-compression tectono-halokinetic activity
No full textInternational audienceFor decades, Mesozoic tectono-halokinetic structures have been increasingly recognized in the peripheral French alpine basins. However, reconstructing the full history and mechanisms of halokinesis during the Mesozoic in these regions remains challenging due to the overprinting effects of Cenozoic compressive tectonics, which have erased much of the evidences of earlier deformations.This severely limits our understanding of the interplay between diapirism, tectonics, and sedimentary processes in sedimentary basins, and the role of pre-compressional inheritances in shaping the internal deformation of orogenic wedges. In the Baronnies (southern subalpine Alps), several Triasic diapirs that were reactivated during Cenozoic compression are exposed, raising questions about the earlier halokinetic activity in the area.In orogenic domains, salt-tectonics is generally inferred from geometric evidences, which are not always well preserved. To address this limit, we developed a geochemical and regional approach, applied to the Mesozoic deposits in the Baronnies. Specifically, we used the strontium (Sr) content of pelagic carbonates deposited in the Vocontian basin (today incorporated in the Alpine prism) as a tracer of potential salinity anomalies associated to submarine diapirism. Rocks samples were collected from Oxfordian to Turonian sedimentary sequences in the deep environments of the Vocontian basin and along its northern (Vercors and Chartreuse), southern (Ventoux) and western (Ardèche-Languedoc) shallow margins. Sr content was measured using X-ray fluorescence (XRF) in the field and then lab-based XRF on both bulk samples and their carbonate fractions. Selected samples were also measured using ICP-OES spectrometry. Sr values were compared to the mean contemporaneous oceanic values of the reference curve established by Renard (1975) to identify possible anomalies.The Sr content exhibits spatial and temporal variability, with both normal and abnormal values relative to the reference curve. Normal values characterise the Late Jurassic and basal Cretaceous periods. In contrast, Valanginian to Aptian values are significantly higher than the reference curve. The largest anomalies are observed in the deep Vocontian basin and suggest local contamination of the sediments by saline material flows. Comparison of the geochemical signal, sedimentary remobilization events (slumps, calciturbidites,…) and the structural and paleo-stresses frameworks point to a renewed halokinesis activity after the Liasic rifting, with diapirs piercing or not the seafloor. In the Baronnies, this Mesozoic activity has significantly deformed the contemporaneous sedimentary sequences, with local overtuned dips and megaflap-type geometries associated with angular unconformities and pitching of the sequences close to the paleodiapir bodies. At the basin scale, wide synclines were flanked by EW submarine ridges which, together with the inherited NE-SW faults divided the Vocontian basin. We corelate these structures with the Early Cretaceous tectono-halokinesis activity in the South East French Basin, with the Vocontian rift forming a major structure between the Valaisan Ocean and the Altlantic rift. This study supports the existence of sutured diapirs in the meridional subalpine Alps with an enhanced tectono-halokinetic activity during Early Cretaceous. The last one created regional weak salt inheritances in the pre-compression Mesozoic sedimentary pile, preconditioning it for deformation during the later compressional phases