Portail HAL de l'Université Picardie Jules Verne
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Le Parlement à l'épreuve du temps: Entre urgence politique et exigence délibérative
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Compound Knowledge Hyper-Heuristic for Large-Scale Network Design Problems
No full textInternational audienceCompound Knowledge Hyper-Heuristic for Large-Scale Network Design Problem
Multi-Scale Modeling of Enzymatic Hydrolysis Efficiency Based on Machine Learning: From Hydrothermal Pretreatment Conditions to Lignin Structural Properties
No full textInternational audienceThe increasing depletion of fossil resources and escalating environmental challenges highlight the urgent need for efficient utilization of lignocellulosic biomass.However, the inherent recalcitrance of lignocellulose hampers its enzymatic degradation and conversion efficiency, making pretreatment essential to improve enzyme accessibility and promote carbohydrate release. In this study, we developed predictive models of enzymatic hydrolysis based on hydrothermal pretreatment by integrating multidimensional features, including feedstock composition, process parameters, and pretreatment outcomes. Among multiple machine learning algorithms, XGBoost demonstrated superior performance across training, testing, and validation sets (R² = 0.994, 0.841, and 0.856, respectively). At the microscopic level, lignin was further examined as a key factor. The correlation models were established between lignin physicochemical properties, including molecular weight (Mw, Mn), interunit linkages (β-O-4, β-5), functional groups (phenolic, aliphatic, and carboxyl hydroxyl groups), and enzymatic conversion efficiency. XGBoost again demonstrated as the best model, which interpretability was enhanced using feature importance ranking, SHAP dependency analysis, and two-dimensional partial dependence plots (2D-PDP), revealing cross-scale, multidimensional mechanisms within the pretreatment system. By integrating macro-level regulation and micro-level mechanistic models, this study provided a systematic framework for understanding biomass hydrolysis and offers data-driven guidance for optimizing pretreatment strategies and improving conversion efficiency.</div
De/colonizing Repesentations of Slavery in European Museums: Artistic, Curatorial and Theoretical Approaches
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Ursula K. Le Guin, l’autrice de science-fiction qui nous invite à réinventer le monde
No full textInternational audienceAlors que Rennes (Ille-et-Vilaine) s’apprête à donner son nom à une rue et que la chanteuse Rosalia la cite en interview, Ursula K. Le Guin, disparue il y a six ans, nous a laissé une œuvre qui alimente plus de réflexions et de discussions que jamais, débordant largement les contours des littératures dites de l’imaginaire. De l’utopie anarchiste des Dépossédés à l’école des sorciers de Terremer en passant par les pérégrinations des ethnographes intergalactiques du Cycle de l’Ekumen, les mondes de fiction de Le Guin et leur philosophie nourrie de taoïsme continuent de nous proposer des manières alternatives de penser la crise et de concilier l’inconciliable
Carbon fiber reinforced 3D-printed PLA sheets for self-powered electronic applications
No full textInternational audienceIn this study, a sustainable triboelectric nanogenerator (TENG) was developed using biodegradable polylactic acid (PLA) and a non-biodegradable carbon fiber-reinforced PLA matrix (PLA-CF) fabricated via fused deposition modeling (FDM), coupled with a water-soluble polyvinyl alcohol (PVA) film prepared through the solvent casting method. The use of biodegradable and environmentally friendly polymer materials aims to address the ecological concerns associated with conventional non-biodegradable polymers used in TENG devices. Carbon fiber incorporation enhanced the triboelectric properties of PLA by improving its surface roughness, electron affinity, and mechanical strength. The fabricated materials were characterized using X-ray diffraction spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and water contact angle measurements. Mechanical strength was evaluated using a universal testing machine. The assembled TENG, comprising PLA/PLA-CF as the negative triboelectric layer and PVA as the positive triboelectric layer, demonstrated stable voltage output capable of lighting LEDs and functioning as a self-powered touch-counting sensor. This work highlights the potential of FDM-based polymer composites for efficient energy harvesting and interactive sensing applications
Vulnerability to climate change and funding squeeze in Sub-Saharan Africa
No full textInternational audienceThe paper investigates whether and how climate vulnerability affects public debt. We focus on a region that is highly vulnerable to climate change, but scarcely explored, namely Sub-Saharan Africa. On a sample of annual data covering 38 Sub-Saharan African countries over the period 2000–2022, our results highlight a negative relationship between the debt-to-GDP ratio and climate vulnerability. This relationship holds even when we control for several factors, namely financial crises, sovereign defaults or debt relief programs. Moreover, we account for cross-country dependence and heterogeneity and use variables measuring organized violence and adaptive capacity to climate change as instruments for climate vulnerability. When analyzing the impact of fiscal rules, our results show evidence that while climate vulnerability reduces the debt-to-GDP ratio in countries with expenditure and credible budget balance rules, establishing revenue and credible debt rules may alleviate the funding squeeze
The weight of silent criteria: ESG score performance and investment attractiveness in sub-Saharan Africa
No full textInternational audienceThis article empirically examines the impact of ESG (Environmental, Social and Governance) scores on investment attractiveness in Sub-Saharan Africa, mobilizing a panel of data covering 40 countries over the period 2000-2023. The analysis is based on several econometric techniques, notably ordinary least squares (OLS) and generalized least squares (GLS), the results of which reveal a positive and statistically significant relationship between ESG performance and investment flows. The Kinky Least Squares (KLS) method was used to reinforce the robustness of the estimates and correct for potential endogeneity bias, confirming the robustness of the initial results. Furthermore, the inclusion of governance variables such as political stability, control of corruption and rule of law significantly enhances the attractiveness of the region's economies. These results suggest that improving ESG indicators, at both state and corporate levels, is a strategic lever for attracting investment in a sustainable way, and call for greater institutionalization of ESG practices in public policy and corporate reporting
Case report and literature review of neurodevelopmental syndrome linked to DOT1L variants
No full textInternational audienceIntroduction: The DOT1L gene encodes a histone lysine methyltransferase that has the distinctive characteristic of being composed of a DOT1 catalytic domain that targets lysine 79 of the core globular domain of histone H3. DOT1L missense variants have recently been implicated in an autosomal dominant inheritance syndrome with developmental delay and congenital anomalies in postnatal cohorts. We report the twenty-sixth patient with this disorder.Methods: Trio genome sequencing (GS) was performed in a patient with developmental delay.Results: Clinical examination showed a predominant global developmental delay affecting language, with cerebral abnormalities visible on magnetic resonance imaging, hypotonia, and ophthalmological and musculoskeletal abnormalities. GS revealed a de novo heterozygous missense variant in exon 3 of DOT1L (c.161C > T; p.(Ala54Val)), which is reported for the first time as the cause of developmental delay and congenital anomalies.Discussion: Among the 26 reported patients, 23 have missense variants, two have truncating variants, and one has an in-frame deletion. The mode of transmission is predominantly de novo. Current studies indicate multiple pathogenic mechanisms underlying DOT1L-related disorder, including both gain-of-function and loss-of-function effects, underscoring the complexity of the disease etiology. Although the gene exhibits intolerance to loss-of-function variants, a considerable number of truncating variants are observed in control populations, suggesting incomplete penetrance and heterogeneity in the phenotypic expression of DOT1L-associated disorder. No phenotype-genotype correlation could be established. Among reported patients, including ours, the most consistent clinical manifestations are global developmental delay, predominantly affecting language and behavior, and possibly distinctive facial features