Portail HAL-PSL
Not a member yet
293219 research outputs found
Sort by
YOLO: yavājjīvaṃ sukhaṃ jīvet. The Materialist Doctrine in Vedāntadeśika’s Paramatabhaṅgam
No full textInternational audienc
Methylphenidate and Psychotic Symptoms in Children and Adolescents: A Disproportionality Analysis on the WHO Safety Database (VigiBase)
No full textInternational audienceBackground: Methylphenidate (MPH) is widely used to treat attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. However, concerns persist about its potential to induce psychotic symptoms, including hallucinations. Objective: This study aimed to evaluate the association between MPH exposure and psychotic symptoms in children and adolescents using VigiBase®, the World Health Organization global pharmacovigilance database. Methods: We conducted a retrospective, observational study using disproportionality analysis on reports from children and adolescents (5–17 years) exposed to MPH and other ADHD drugs (amitriptyline, atomoxetine, clomipramine, clonidine, desipramine, guanfacine, and nortriptyline). Multivariate logistic regression was used to calculate adjusted reporting odds ratios (aRORs) of psychotic symptoms in MPH-exposed children and adolescents. Results: Among 1,992 cases of psychotic symptoms, 1,232 were MPH-associated, with 51.7% classified as serious; significant disproportionalities were observed for the overall age range (aROR = 1.27; 95% confidence intervals [CI]: 1.15–1.40) and the 5–11 (children) age group (aROR = 1.35; 95%CI: 1.19–1.53). Of 1,250 hallucination cases, 809 were MPH-associated, with 59.2% serious; significant disproportionalities were found for the entire age range (aROR = 1.35; 95% CI: 1.19–1.52) and the children age group (aROR = 1.43; 95% CI: 1.23–1.67). The most common type of hallucination was visual (43.2%). MPH discontinuation or dose reduction led to a significantly higher rate of symptom abatement (88.6% of cases) compared to those without these measures (12.0%) ( p < .001). Conclusions: These results suggest that MPH exposure in children is associated with an increased probability of serious psychotic symptoms, including hallucinations, which typically resolve with discontinuation or dose reduction. Further research is needed to better understand the MPH-induced psychotic symptoms
Inundation flow velocities generated by tropical cyclones across atoll islands, derived from two centuries of megaclast deposits in French Polynesia
No full textInternational audienceUnderstanding potential flow velocities during high-energy marine inundation events is crucial for coastal risk assessment. However, modelling struggles to simulate wave energy dissipation across atoll island coastlines. Here, we examined coral reefblocks transported by past tropical cyclones to calculate the minimum flow velocities (MFVs) responsible. Fieldwork on 6 atolls in the Tuamotu archipelago (South Pacific) examined 196 reefblocks, some megaclasts exceeding 300 cubic metres in size. These blocks are scattered between the oceanside reef edge and the atoll lagoon over several hundred metres and suggest flow velocities much higher than those modelled in an assumed ‘extreme reference scenario’ (HS = 12 m). Through U/Th dating and by studying archives and historical aerial photos, the cyclones that moved these reefblocks were identified. Inundation flows generated by two recent cyclones (March and April 1983), two historical cyclones (1903 AD and 1906 AD) and one prehistorical cyclone (54–80 AD) were calculated (storms with swells 10–18.5 m in height). Calculations reveal that previous modelling underestimates flow velocities across atoll islands (inhabited areas) for two reasons: the underestimation of extreme swell heights and the unaccounted-for degradation of shoreline rubble ramparts. During a supercyclone (HS > 15 m), flows can exceed 3 m/s at 350 m from the reef edge and are capable of transporting 20-ton coral blocks. Findings have a wider significance to tropical coral reef coastlines beyond these atolls studied, where the presence of reefblocks can allow hindcasting of the characteristics of prehistorical cyclone inundations
« Le fil d’araignée », Traduction de la nouvelle d’Akutagawa Ryūnosuke (japonais) par Christopher Chassagneux et Lucie Demesy.
No full textAkutagawa Ryūnosuke, « « Le fil d’araignée », Traduction de la nouvelled’Akutagawa Ryūnosuke (japonais) par Christopher Chassagneux et LucieDemesy. », La main de Thôt [En ligne], 13 | 2025, mis en ligne le 23 janvier 2026,consulté le 23 janvier 2026. URL : http://interfas.univ-tlse2.fr/lamaindethot/180
Toward a Better Understanding of Recrystallization Mechanisms of Single Crystal Nickel Based Superalloys During Turbine Blades Processing
No full textInternational audienceA series of experiments investigating the recrystallization (RX) mechanisms of the single crystalline superalloy AM1 during its manufacture have been carried out. High and very high temperature tensile tests were conducted to investigate the effect of the level of plastic deformation and the temperature at which the strain was applied. These parameters were then analyzed for their influence on RX mechanisms during the subsequent solution heat treatment. The strain threshold for RX under various temperature range has been determined and it has been shown that RX is more likely to occur within the 900-1150 °C deformation temperature range. Some correlations between deformation mechanisms and volume fraction of γ' in this type of alloy over these temperature ranges have been discussed in order to explain these trends. In addition, non-isothermal tensile tests were conducted to reproduce as closely as possible the thermomechanical path experienced during the manufacturing of single-crystalline parts using investment casting. A strong correlation has been demonstrated between the thermomechanical path followed during non-isothermal tests that lead to the appearance of recrystallized grains and the "recrystallization zone" identified from pure isothermal tests. This correlation becomes evident when the thermomechanical path crosses this zone. The effect of nonisothermal thermomechanical loading on microstructure was studied by EBSD analysis. Significant local misorientation was observed around microstructural inhomogeneities such as casting pores and eutectic/casting pore pairs. These local rotations suggest that microstructural inhomogeneities act as stress concentrators leading to the first RX nuclei once a super-solvus solution heat treatment has been applied
Governance, Productivity and Economic Development
No full textInternational audienceABSTRACT This paper explores the interplay between transfer policies, R&D, corruption, and economic development using a general equilibrium model with heterogeneous agents and a government. The government collects taxes, redistributes fiscal revenues, and undertakes public investment (in R&D, infrastructure, etc.). Corruption is modeled as a fraction of tax revenues that is siphoned off and removed from the economy. We first establish the existence of a political‐economic equilibrium. Then, using an analytically tractable framework with two private agents, we examine the effects of corruption and evaluate the impact of various policies, including redistribution and innovation‐led strategies
Impact of oxic and thermal transient phases on corrosion of carbon steel in different cementitious media: insights from new in situ experiments
No full textInternational audienceThe impact of oxic and thermal transient phases on corrosion of carbon steel in a cementitious environment was studied through three in situ experiments (Tournemire underground research laboratory, France). For 2 years, heated metallic samples (80°C) were placed in direct or indirect contact with two different cementitious materials: a low-pH bentonitic cement grout (BCG) and a Portland cement paste material (CEM I). Mineralogical and microstructural analyses were carried out in an attempt to identify the combined effects of pH, chemistry and microstructure properties associated with such specific cementitious media on steel corrosion mechanisms. Additionally, in situ electrical resistance corrosion sensors allowed continuous monitoring of the corrosion rates corresponding to each of the three field experiments. Post-mortem characterization indicated that metallic samples embedded in low-pH BCG were heavily damaged and exhibited high corrosion rates. Conversely, steel samples in contact with a highly alkaline CEM I environment appeared to be much less impacted by corrosion processes and revealed extremely low corrosion rate values. A comparison between these field experiments observations and results previously obtained through complementary laboratory mock-up tests finally enabled the evaluation of the impact that variations in geometrical/design aspect existing between in situ and laboratory tests can induce on material degradation
Ultra‐Fast Isothermal Formation of DNA Nanostructures in Culture Media: Application to In Situ Assembly of DNA Origami With Living Cells
No full textInternational audienceSynthetic DNA strands are programmable and biocompatible building blocks that can be combined through hybridization to form user‐defined nanostructures, but their assembly traditionally requires cell‐incompatible conditions, imposing a lengthy ex situ fabrication step before any application with living matter. Here we demonstrate for the first time that 2D and 3D DNA origami structures can isothermally self‐assemble at 37°C within minutes, directly in cell culture media, both in the absence and in the presence of living cells. Scaffold‐free structures of extended dimensions, such as micrometer‐long DNA nanotubes, can also self‐assemble when the system is given more time to evolve. With human cell lines, 2D and 3D origami structures in situ self‐assemble in 5 to 15 min, and remain stable for about 24 h and up to 3 days when actin monomers are added. Similar self‐assembly performance is observed in the presence of more complex tissue‐like systems, such as human induced pluripotent stem cells evolving into cerebral organoids. This ultra‐fast, life‐compatible self‐assembly method drastically simplifies the fabrication of complex DNA nanostructures and enables the creation of in situ self‐assembling nanomachines for direct and adaptive interactions with living cells
Polyak-Łojasiewicz inequality is essentially no more general than strong convexity for functions
No full textThe Polyak-Łojasiewicz (PŁ) inequality extends the favorable optimization properties of strongly convex functions to a broader class of functions. In this paper, we prove a theorem (also obtained by Criscitiello, Rebjock and Boumal in an earlier blog post) showing that the richness of the class of PŁ functions is rooted in the nonsmooth case since sufficient regularity forces them to be essentially strongly convex. More precisely, we prove that if f is a PŁ function having a bounded set of minimizers, then it has a unique minimizer and is strongly convex on a sublevel set of the form {f ≤ a}. We show that this implies a result of Asplund on properties of the squared distance function, and discuss some consequences on smoothness assumptions in results in the literature. </div