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Bases de physiologie végétale et flux de sèves
No full textNational audienceLes bases physiologiques pour comprendre la nature des sèves d'un arbre, leur fabrication et leur circulation
Physicochemical Properties and Bioreactivity of Sub‐10 μm Geogenic Particles: Comparison of Volcanic Ash and Desert Dust
No full textInternational audienceExposure to ambient particulate matter (PM) with an aerodynamic diameter of <10 μm (PM 10 ) is a well-established health hazard. There is increasing evidence that geogenic (Earth-derived) particles can induce adverse biological effects upon inhalation, though there is high variability in particle bioreactivity that is associated with particle source and physicochemical properties. In this study, we investigated physicochemical properties and biological reactivity of volcanic ash from the April 2021 eruption of La Soufrière volcano, St. Vincent, and two desert dust samples: a standardized test dust from Arizona and an aeolian Gobi Desert dust sampled in China. We determined particle size, morphology, mineralogy, surface texture and chemistry in sub-10 μm material to investigate associations between particle physicochemical properties and observed bioreactivity. We assessed cellular responses (cytotoxic and pro-inflammatory effects) to acute particle exposures (24 hr) in monocultures at the air-liquid interface using two types of cells of the human airways: BEAS-2B bronchial epithelial cells and A549 alveolar type II epithelial cells. In acellular assays, we also assessed particle oxidative potential and the presence of microorganisms. The results showed that volcanic ash and desert dust exhibit intrinsically different particle morphology, surface textures and chemistry, and variable mineralogical content. We found that Gobi Desert dust is more bioreactive than freshly erupted volcanic ash and Arizona test dust, which is possibly linked to the presence of microorganisms (bacteria) and/or nanoscale elongated silicate minerals (potentially clay such as illite or vermiculite) on particle surfaces
Paradoxos temporais na implementação e avaliação de um programa de apoio à orientação estudantil
No full textInternational audienceIn France, the evaluation of educational programs is becoming increasingly prevalent. It is, for instance, systematically integrated into projects funded under the "New University Curricula" initiative. In response to high failure and reorientation rates in the first year of undergraduate studies (Minault et al., 2020), orientation support programs, such as Réopass at the University of Clermont-Auvergne, have recently emerged. However, their evaluation often focuses on outcomes (such as enrollment and success rates), overlooking the situated processes of their implementation. This leads us to consider the Réopass program as a socially constructed entity embedded in its environment (Younès, 2020). This presentation aims to shed light on the temporal paradoxes inherent in the implementation of this program, drawing on the concept of "temporal synchronizations" (Pineau, 2000), which highlights tensions between institutional and individual rhythms in program implementation. Our evaluation of Réopass has led us to identify five paradoxes that illuminate some of its implementation processes. Institutional rhythms appear to synchronize students' orientation timelines, although not all students develop their academic plans "on time." The program’s timeline conflicts with that of faculty advisors, who are often overwhelmed by multiple and sometimes peripheral responsibilities beyond their teaching and research roles. Institutional regulations, particularly those governing student management, synchronize the program's implementation. These regulations also dictate the timing of program evaluations and adjustments, limiting and structuring the possible modifications to Réopass. Finally, institutional timeframes synchronize the temporality of student support, which inherently requires time (Colognesi et al., 2021; Paul, 2020; Savickas et al., 2010), contrasting with the prevailing value placed on fast academic trajectories (Paivandi, 2015). Our findings highlight the need to consider temporal paradoxes in the institutional evaluation of such programs, to better align assessments with the contextual contingencies of program implementation.En France, l'évaluation des dispositifs éducatifs est croissante. Elle est, par exemple, systématiquement intégrée aux projets financés « Nouveaux Cursus à l’Université ». Face aux taux élevés d’échec et de réorientations (Minault et al., 2020) en première année de licence, des dispositifs d’accompagnement à l’orientation, comme Réopass implanté à l’Université Clermont-Auvergne, ont récemment vu le jour. Cependant, leur évaluation porte souvent sur leurs résultats (taux d’inscription, de réussite notamment), omettant les processus de leur implantation située, qui nous conduisent à considérer le dispositif Réopass comme un construit social situé dans son milieu (Younès, 2020). Cette communication tentera de mettre en lumière les paradoxes temporels inhérents à l'implantation de ce dispositif, en nous appuyant sur le concept de « synchronisations temporelles » (Pineau, 2000), qui souligne les tensions entre rythmes institutionnels et individuels dans l’implantation du dispositif. Notre démarche évaluative de Réopass nous a conduit à repérer cinq paradoxes éclairant certains des processus de son implantation. Ainsi, 1) le rythme institutionnel synchroniserait le rythme des étudiants dans leur orientation, tous les étudiants n’ayant pas élaboré un projet « dans les temps ». 2) Le rythme du dispositif se confronterait à celui des enseignants-référents, souvent saturé par des missions multipliées et parfois périphériques au métier d’enseignant-chercheur. 3) Le rythme institutionnel (règles temporelles de gestion des étudiants notamment) synchroniserait l’implantation du dispositif. 4) Il synchroniserait également le rythme des évaluations-régulations du dispositif, limitant et cadençant les possibles régulations de Réopass. Enfin, 5), il synchroniserait la temporalité de l’accompagnement, requérant du temps (Colognesi et al., 2021 ; Paul, 2020 ; Savickas et al., 2010), au-delà de la rapidité des parcours érigée comme valeur (Paivandi, 2015). Les résultats soulignent la nécessité de considérer les paradoxes temporels dans l’évaluation institutionnelle des dispositifs afin de permettre un réajustement de l’évaluation au plus proche des contingences contextualisée d’implantation
Clicked H-Shaped Arylopeptoids
No full textInternational audienceThis study presents a tentative on solid-pase synthesis of H-shaped and ladder-type compounds. A facile method for the synthesis of H-shaped N-alkylated aminomethyl oligobenzamides, i.e., arylopeptoids by on-resin homodimerization via the Copper(I)-Catalyzed-Alkyne-Azide-Cycloaddition (CuAAC) reaction is reported. While successful, further oligomer elongation proved difficult and this issue was addressed using an elongated oligomer to conduct inter-strand cross-linking. Further CuAAC functionalization could be performed after elongation with additional alkyne groups to enhance diversity
"Les apports du droit européen de la concurrence en matière de stabilité financière"
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Financements intermédiés et fragilité en Afrique
No full textNonobstant le grand intérêt sur la question du financement des Etats fragiles, très peu d'études se sont penchées jusqu'ici sur l'impact des ressources externes sur la fragilité dans les pays. Cette étude vient compléter la littérature et se penche sur l'impact spécifique des financements intermédiés sur la fragilité des pays africains. L'étude utilise la méthode de l'appariement des scores de propension appliquée à un panel de 50 pays africains sur la période 2009-2019, pour estimer l'effet des financements intermédiés sur la fragilité suivant quatre algorithmes d'appariement. Les résultats sont significatifs à 5% et montrent que le financement intermédié réduit la fragilité des pays concernés de 8,1% à 13,1% dépendamment de l'algorithme retenu. Le test de robustesse confirme cet impact positif et significatif indépendamment de la source de financement. Ces résultats devraient intéresser les décideurs politiques, les institutions financières internationales et les banques centrales, de même que les chercheurs dans la formulation des politiques et stratégies d'inclusion financière et de renforcement de la résilience dans les Etats fragiles.</div
A Survey on Path Validation: Towards Digital Sovereignty
No full textInternational audienceWith the increasing number of devices and users accessing the Internet, managing data transmission has emerged as a critical concern for both individuals and businesses. Path validation is the process of enforcing and then verifying a path during information transmission. Controlling the path data takes is crucial for ensuring digital sovereignty, establishing rightful control over assets like data, technology, and infrastructure. This not only arms an entity's autonomy, security, and privacy in the digital realm, but also underscores the importance of regulating access and usage in accordance with local laws and regulations. Path validation has several applications, including trac engineering, service chaining, and inter-domain routing. In this work, we systematize the knowledge surrounding path validation, particularly on the variants and extensions of the inter-domain routing protocol, the Border Gateway Protocol (BGP). We establish three classications: one for attacks threatening the digital sovereignty of information transmission, another for path validation protocols, and the last for BGP variants and extensions. We analyse each solution against the selected attacks. Finally, we discuss open research problems towards achieving digital sovereignty during data transmission.The authors acknowledge the support of the Chaire de conance numérique (12LIMO11LIMOS on FCA) of the Clermont Auvergne University Foundation.</p
"Les juges et l'intégration européenne en matière de fiscalité directe"
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P1056 Effectiveness and Safety of Upadacitinib Induction Therapy in Real-World Setting for 234 Patients with Crohn’s Disease: A GETAID Multicentre Cohort Study
No full textInternational audienceBackgroundWhile upadacitinib has demonstrated its efficacy as an induction treatment for Crohn’s disease (CD) in two phase 3 randomized, placebo-controlled trials1, real-world data remain limited.MethodsFrom September 2022 to September 2024, all consecutive patients with refractory CD treated with once-daily upadacitinib 45 mg in 30 French and Belgian GETAID centres were retrospectively included. The primary endpoint was steroid-free clinical remission (SFCR) at week 12, defined as a Harvey-Bradshaw Index (HBI) score of < 4. Secondary endpoints included clinical response (decrease of ≥ 3 points in the HBI score and/or an HBI score < 4), clinical remission, biological remission (calprotectin ≤ 250 µg/g, or CRP ≤ 5 if calprotectin was unavailable), endoscopic or radiological (IUS and/or MRI) response, and adverse events (AEs).Results234 patients were included, all of whom had been previously exposed to at least one biologic (median 4, IQR[3-4]), and 125 (53.9%) had undergone prior intestinal resection (Table 1). At week 12, SFCR was observed in 107 patients (n=107/197, 54%), clinical response in 120 (n=120/190, 63%) and clinical remission in 111 (n=111/197, 56%). Ninety-two (n=92/179, 51%) achieved biological remission and endoscopic or radiological response was observed in 19 (n=19/40, 48%) patients (Figure 1). Respectively 28 (n=28/37, 76%) and 20 (n=20/37, 54%) of patients with articular EIMs achieved clinical response and remission. For cutaneous EIM, clinical response was achieved in 10 patients (n=10/11, 91%), and clinical remission was achieved in nine patients (n=9/11, 82%). In multivariate analysis, body mass index < 18.5 kg/m2 (OR=0.09, 95%CI: 0.01-0.33, p=0.002) and HBI > 7 (OR=0.24, 95%CI: 0.12-0.47, p<0.0001) were associated with lower rates of SFCR at W12 while the number of prior biologics did not influence SFCR (OR = 0.72, 95% CI: 0.35-1.48; p = 0.36).At week 12, 35 (15%) patients discontinued upadacitinib (lack of effectiveness, n=31; AEs, n=2 and other, n=2). CD-related hospitalization was needed in 18 (7.7%) patients, and 4 (1.7%) underwent intestinal resection. Sixty-eight AEs occurred in 61 patients (26%), including 19 serious AEs, corresponding to 18 cases of CD exacerbation and one case of colonic EBV-associated lymphoproliferative disorder. Acne was observed in 25 (10.7%), justifying treatment discontinuation in one (0.4%).ConclusionIn this real-world cohort of highly refractory CD patients, upadacitinib induction resulted in a clinical response in about two-thirds of patients and SFCR in half of patients