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Data science for insurance fraud detection: a review
No full textInternational audienceThe chapter 'Data Science for Insurance Fraud Detection: A Review' delves into the application of data science and machine learning techniques to combat insurance fraud. It begins by discussing the significance of insurance fraud and its impact on the industry, followed by an overview of the historical development of fraud detection methods. The chapter then categorizes fraud detection techniques into unsupervised, supervised, and social network learning approaches, each with its unique advantages and challenges. Notably, the text emphasizes the importance of cost-sensitive learning to address the rarity and high cost of fraudulent claims effectively. The chapter also includes an empirical illustration, demonstrating the superior performance of advanced machine learning models compared to traditional econometric methods in both statistical and financial terms. Throughout, the text highlights the evolving nature of fraud and the need for adaptive, real-time fraud detection systems. This comprehensive review offers valuable insights for professionals seeking to enhance their fraud detection strategies, making it a must-read for those in the insurance and risk management sectors
Why are SDHI pesticides of concern to beekeepers and scientists?
No full textInternational audienceResults show that SDHIs pose a significant threat to pollinators, biodiversity and public health. Given that mitochondrial dysfunction at the level of succinate dehydrogenase can lead to serious diseases such as neurodevelopmental disorders and cancer, it is imperative to better assess the toxicity of SDHIs at low doses and over the long term. Our findings also show that maximum residue limits (MRLs) should be reduced to offer better protection. As SDHIs are frequently used in combination with other fungicides, such as triazoles and strobilurins (e.g., straw cereals), it is necessary to promote alternative methods to reduce the use of SDHIs
The antimicrobial activity of ETD151 defensin is dictated by the presence of glycosphingolipids in the targeted organisms
No full textInternational audienceFungal infections represent a significant global health concern, with a growing prevalence of antifungal drug resistance. Targeting glucosylceramides (GlcCer), which are functionally important glycosphingolipids (GSL) present in fungal membranes, represents a promising strategy for the development of antifungal drugs. GlcCer are associated with the antifungal activity of certain plant and insect defensins. The 44-residue ETD151 peptide, optimized from butterfly defensins, is active against several fungal pathogens. ETD151 has been shown to induce a multifaceted mechanism of action (MOA) in Botrytis cinerea , a multiresistant phytopathogenic fungus. However, the target has yet to be identified. Our findings demonstrate that the presence of GlcCer in membranes determines the susceptibility of Pichia pastoris and Candida albicans toward ETD151. To ascertain whether this is due to direct molecular recognition, we demonstrate that ETD151 selectively recognizes liposomes containing GlcCer from B. cinerea , which reveals a methylated-sphingoid base structure. The dissociation constant was estimated by microscale thermophoresis to be in the µM range. Finally, fluorescence microscopy revealed that ETD151 localizes preferentially at the surface of B. cinerea . Furthermore, the majority of prokaryotic cells do not contain GSL, which explains their resistance to ETD151. We investigated the susceptibility of Novosphingobium capsulatum , one of the rare GSL-containing bacteria, to ETD151. ETD151 demonstrated transient morphological changes and inhibitory growth activity (IC 50 ~75 µM) with an affinity for the cell surface, emphasizing the critical importance of GSL as target. Understanding the MOA of ETD151 could pave the way for new perspectives in human health and crop protection
Traverser les frontières de connaissances avec ChatGPT : analyse du rôle de l’intelligence artificielle générative dans la réalisation du mémoire de master
No full textInternational audienceThe widespread adoption of generative artificial intelligence (AI) among students has disrupted their practices, notably when producing master thesis, and has raised ethical issues. This qualitative study conducted with both students and teachers provides a better understanding of students’ hybrid productions and how they are perceived by teachers. Drawing on the theory of boundary objects and boundary spanners, our findings highlight the new interactions and a critical analysis of the tensions involved in this process. We formulate proposals for integrating this new actor (AI), regulating practices and changing assessments to resolve these tensions putting teachers back at the heart of knowledge integration process.L’adoption rapide des outils d’intelligence artificielle générative par les étudiants a bousculé leurs pratiques, notamment lors de la production de mémoire, engendrant des questionnements éthiques. L’étude qualitative menée auprès d’étudiants et d’enseignants permet de mieux comprendre ces pratiques étudiantes qui donnent lieu à une production hybride et leurs perceptions par les enseignants. En mobilisant la théorie des objets frontières et des acteurs frontières, nos résultats font apparaître les nouvelles interactions lors de ce processus et offrent une analyse critique des tensions en jeu. Nous formulons des propositions pour intégrer ce nouvel acteur, encadrer les pratiques, faire évoluer les évaluations pour résoudre ces tensions et replacer l’enseignant au cœur du dispositif d’intégration des connaissances
Sustainable electrochemical production of H₂O₂ on carbon blacks: Structural properties as key drivers
No full textInternational audienceThe electrochemical production of H₂O₂ via the two-electron oxygen reduction reaction (2e⁻ORR) has emerged as a sustainable alternative to the traditional anthraquinone process, which involves hazardous solvents and generates significant waste. Carbon blacks are extensively utilized as benchmark electrocatalysts for H₂O₂ production, with performance often attributed to electrical conductivity, composition, or hydrophobicity. However, the role of key parameters such as structural properties and surface area remains underexplored. To clarify this, we have analyzed four commercial carbon blacks commonly reported in the literature (Vulcan XC-72, Printex XE2, Superior Graphite and Prolabo) as benchmark electrocatalysts for the electrogeneration of H₂O₂. Results indicate that electrocatalytic activity in H₂O₂ accumulation assays of carbon blacks can be rationalized through a comprehensive characterization of their structural properties, with a minor impact of conductivity and composition (for un-functionalized carbon blacks with a high carbon content). Our results also highlight the need to complement the characterization of the electrocatalytic activity in rotating ring-disk electrodes -a common screening practice-with H₂O₂ accumulation tests to account for the impact of parasitic reactions in the long-term productivity and selectivity. This study contributes to the rational design of sustainable carbon-based electrocatalysts for H₂O₂ production, advancing green and efficient electrochemical processes
Magma degassing and its impact on Earth’s atmosphere: from magma oceans to lava lakes
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SUDA: A SUrface Dust Analyser for Compositional Mapping of the Galilean Moon Europa
No full textInternational audienceAbstract The Surface Dust Analyser (SUDA) is a mass spectrometer onboard the Europa Clipper mission for investigating the surface composition of the Galilean moon Europa. Atmosphereless planetary moons such as the Galilean satellites are wrapped into a ballistic dust exosphere populated by tiny samples from the moon’s surface produced by impacts of fast micrometeoroids. SUDA will measure the composition of such surface ejecta during close flybys of Europa to obtain key chemical signatures for revealing the satellite’s composition such as organic molecules and salts, history, and geological evolution. Because of their ballistic orbits, detected ejecta can be traced back to the surface with a spatial resolution roughly equal to the instantaneous altitude of the spacecraft. SUDA is a Time-Of-Flight (TOF), reflectron-type impact mass spectrometer, optimized for a high mass resolution which only weakly depends on the impact location. The instrument will measure the mass, speed, charge, elemental, molecular, and isotopic composition of impacting grains. The instrument’s small size of 268 mm × 250 mm × 171 mm , radiation-hard design, and rather large sensitive area of 220 cm 2 matches well the challenging demands of the Clipper mission
Optimal choice of closest approach distance for a comet flyby: Application to the Comet Interceptor mission
No full textInternational audienceA comet flyby, like the one planned for the Comet Interceptor mission, takes place under conditions that remain largely unknown up to the moment of encounter. A detailed trajectory design phase, which includes verification of the technical limitations implied by the flyby geometry, precedes target comet selection. Thus the flyby velocity and the solar zenith angle at closest approach are known in advance. Solar irradiance and the neutral gas expansion speed can be estimated reasonably well. However, the comet outgassing rate, the dust production rate, and the solar wind conditions are only known within broader uncertainty margins. The present paper aims to optimally choose the one degree of freedom that is available for tuning the flyby conditions: the distance of closest approach. This choice is based on a simplified formalism that expresses, on one hand, the science return to be expected as a function of the closest approach distance, and, on the other hand, the risks implied by a close approach. This is done by performing Monte Carlo simulations over a large sample of possible comet flyby configurations, based on the expected probability distributions of the gas and dust production rates and the solar wind conditions, for different closest approach distances. For small flyby distances, a spacecraft has the opportunity to study the nucleus, the neutral gas coma, and the induced magnetosphere from up close, benefiting the science return. There is a trade-off to be made against the cometary dust collision risk, which becomes larger close to the nucleus. This trade-off is illustrated for the case of the Comet Interceptor main spacecraft and the two probes it plans to release. The change of the optimal flyby distance with gas and dust production rate, solar EUV flux, and flyby speed is discussed