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Mid- and Far-Infrared Spectral Signatures of Mineral Dust from Low- to High-Latitude Regions: significance and implications
No full textInternational audienceMineral dust absorbs and scatters solar and infrared radiation, thereby affecting the radiance spectrum at the surface and top-of-atmosphere and the atmospheric heating rate. While half of the outgoing thermal radiation is emitted in the far infrared (FIR, 15–100 μm), knowledge of the optical properties and thermal radiative effects of dust is currently limited to the mid-infrared region (MIR, 3–15 μm). In this study we performed pellet spectroscopy measurements to evaluate the MIR and FIR contribution to dust absorbance and explore the variability and spectral diversity of the dust signature within the 2.5–25 μm range. Thirteen dust samples re-suspended from parent soils with contrasting mineralogy were investigated, including low and mid latitude dust (LMLD) sources in Africa, America, Asia, and Middle East, and high latitude dust (HLD) from Iceland. Results show that the absorbance of dust in the FIR up to 25 μm is comparable in intensity to that in the MIR. Also, spectrally different absorption (position and shape of the peaks) is observed for HLD compared to LMLD, due to differences in mineralogical composition. Corroborated with the few available literature data on absorption properties of natural dust and single minerals up to 100 μm wavelength, these data suggest the relevance of MIR and FIR interactions to the dust radiative effect for low to high latitude sources. Furthermore, the dust spectral signatures in the MIR and FIR could potentially be used to characterise the mineralogy and differentiate the origin of airborne particles based on infrared remote sensing observations
Nakfa : La guerre devient héritage, l'héritage devient prison.
No full textInternational audienceLorsque les combattants du Front populaire de libération de l'Érythrée (FPLE) pénètrent dans Asmara le 24 mai 1991, après trente années de guerre contre l'Éthiopie, ils ne libèrent pas seulement une capitale coloniale italienne aux façades Art déco. Ils consacrent une victoire stratégique forgée dans les montagnes érythréennes, autour d'un point nodal devenu mythique : Nakfa. Cette petite ville, perchée à 1 800 mètres d'altitude, incarne la capacité d'un mouvement de guérilla à transformer une forteresse naturelle en socle d'un appareil militaire et administratif capable de résister à l'une des plus puissantes armées d'Afrique subsaharienne entre 1977 et 1988. Il n’est donc guère étonnant que ce nom devienne aussi celui de la monnaie nationale instituée par la suite
Your home, my home, our home ? The appropriability of shared domestic spaces in the context of intergenerational coresidence
No full textInternational audienceAccess to housing is nowadays an issue for young people. Simultaneously many elderly people are experiencing loneliness. In this context, intergenerational coresidence services and platforms are developed, with the promise of addressing these issues. Their success depends on the desire of both target audiences to engage in co-housing practices with members of a different age-group. This raises the question of the appropriability (or not) of intergenerational shared spaces and the conditions under which their (dis)appropriation can be carried out by young and older individuals. Based on a qualitative study conducted with ten respondents belonging to two contrasting age groups, we highlight the similarities and differences in the meaning given to the concepts of home and intergenerational shared home. We identify the modalities under which shared domestic spaces can become different kinds of home (my place, your place, our place). This research contributes to the growing body of literature on contemporary modifications of the home by shedding light on generational approaches to home appropriation
Association Between Metabolic Syndrome, Obesity, and Cognitive Performances in Individuals With Bipolar Disorders: Cross‐Sectional and Longitudinal Analyses in the FACE ‐ BD Cohort
No full textInternational audienceIntroduction: Metabolic syndrome (MetS) has been suggested to be associated with cognitive impairments in bipolar disorder (BD); however, studies are limited by small sample sizes or cross-sectional design. Our objective is to evaluate the cross-sectional and longitudinal associations between MetS and cognitive performances in a large cohort of individuals with BD.Methods: 1175 individuals with a DSM-IV diagnosis of BD were included from the FACE-BD cohort, assessed with a standardized battery of clinical and neuropsychological tests and followed up with a cognitive retest at 2 years for a subsample (n = 367). A global cognitive index was created by using a Principal Component Analysis. Associations between MetS and cognitive performances at baseline were explored using multiple analyses of covariance and linear mixed models were used for longitudinal data.Results: The prevalence of MetS was 21.5% in this sample. Multivariable analyses identified associations between MetS and poorer cognitive performance in the cross-sectional analysis, independently of age, gender, education level, psychotropic treatments, and comorbidities. Specifically, individuals with MetS showed poorer results (global cognitive index, cognitive flexibility, inhibition, and verbal memory). After adjustment, the longitudinal analysis showed no change in the global cognitive index at year 2 and no time × metabolic syndrome interaction.Conclusions: Our results suggest that MetS is cross-sectionally, but not longitudinally, associated with poorer cognitive performances in BD. This study highlights the importance of systematically and accurately screening for metabolic abnormalities in individuals with BD, and screening for cognitive deficit especially in individuals with MetS. Our results suggest that MetS is not a risk factor for cognitive decline during the follow-up, but further longitudinal studies are required
Volatility and jump activity estimation in a stable Cox-Ingersoll-Ross model
No full textInternational audienceWe consider the parametric estimation of the volatility and jump activity in a stable Cox-Ingersoll-Ross (α-stable CIR) model driven by a standard Brownian Motion and a non-symmetric stable L ́evy process with jump activity α ∈ (1, 2). The main difficulties to obtain rate efficiency in estimating these quantities arise from the superposition of the diffusion component with jumps of infinite variation. Extending the approach proposed in Mies [16], we address the joint estimation of the volatility, scaling and jump activity parameters from high-frequency observations of the process and prove that the proposed estimators are rate optimal up to a logarithmic factor
Efficacy, safety, pharmacokinetics, immunogenicity, and serum neutralizing activity of AZD7442 (tixagevimab-cilgavimab) in patients hospitalized with COVID-19: long-term results from the DisCoVeRy trial
No full textInternational audienceObjectives: To report long-term clinical efficacy, safety, pharmacokinetics, immunogenicity and seroneutralization results of AZD7442 (monoclonal antibodies tixagevimab-cilgavimab) in patients hospitalized with COVID-19.Methods: In this phase 3, double-blind, randomized, multicentre trial, hospitalized adults with PCR-confirmed SARS-CoV-2 infection were randomly assigned 1:1 to receive AZD7442 or placebo, and followed-up until day 456, with repeated blood sample collections until day 365. Clinical endpoints included clinical status, mortality, rehospitalization, SARS-CoV-2 reinfection, and adverse events. Antidrug antibodies and serum drug concentrations were measured. Analyses were performed on the modified intention-to-treat (mITT) populations, defined as participants who actually received the intervention.Results: Between April 28, 2021, and June 23, 2022, 237 participants were randomly assigned to AZD7442 (n = 127) or placebo (n = 110), and 123 participants actually received AZD7442. Participants were infected with pre-Omicron variants in 58.8% (133/226) of cases, versus 33.2% (75/226) of Omicron BA1, BA2, or BA5, and 8% (18/226) missing data. There was no significant difference in the distribution of the 7-point ordinal scale between the AZD7442 and placebo groups, either on day 15 (primary endpoint) (OR = 0.93 [0.54-1.61], p 0.81), or any other time point. Significantly more rehospitalizations occurred between discharge and day 456 among participants who received AZD7442 in the global mITT population (OR = 2.04 [1.03-4.05], p 0.04), but not in the antigen-positive mITT population (OR = 1.78 [0.80-3.94], p 0.15). No significant differences were observed in mortality, SARS-CoV-2 reinfection, or adverse events. In the AZD7442 group, 12 of 87 participants (13.8%) had treatment-emergent antidrug antibodies versus 5 of 69 (7.2%) in the placebo group (OR = 2.02 [0.66-6.14], p 0.21). Serum drug concentrations were detectable up to day 365 for all sampled participants (35/35). Neutralizing antibody titres were significantly higher in the AZD7442 group up to day 180.Conclusions: AZD7442 did not demonstrate any clinical benefit and was safe up to 15 months. This study also provides valuable data on the pharmacokinetics, immunogenicity, and neutralizing activity of AZD7442 in patients hospitalized with COVID-19
Sketches and lessons of past and evicted ‘biogeochemical policies’ in twentieth century France
No full textInternational audienceAccording to the Stockholm Resilience Centre, cycles of biogenic elements (nitrogen, phosphorus) are massively disrupted. This disruption manifests the ‘metabolic rift’ between industrial society and its environment. Using a geohistorical approach, this paper explores French evicted socio-technical trajectories that can be considered as past ‘biogeochemical policies’ i.e., policies which can respond to this disruption of natural cycles: municipal composting, sewage farms, fish ponds, the use as fertiliser of urine and faecal matter. By outlining the factors of their disappearance, which constitute locks that have now to be overcome, it aims to reopen the future of both urban sanitation and agriculture
Le Lexicon français
No full textCe document est la version française complète d’un lexique réalisé dans le cadre du projet international LEXICON par l’équipe constituée de Thierry Chevalarias et Florence Debertonne-Dassule, professeurs de mathématiques et animateurs à l’IREM de Poitiers, et de Michèle Artigue, Brigitte Grugeon, Julie Horoks et Julia Pilet, chercheuses au LDAR (Laboratoire de Didactique André Revuz). Le projet LEXICON a eu pour objectif d’identifier la terminologie didactico-pédagogique dont disposent des enseignants de mathématiques expérimentés de collège pour décrire ce qui se passe dans une classe de ce niveau d’enseignement. Lancé par David Clarke, professeur à Melbourne University et spécialiste des études comparatives en éducation mathématique, il a impliqué des équipes d’enseignants et chercheurs de 10 pays : Allemagne, Australie, Chili, Chine, Corée du Sud, Finlande, France, Japon, République Tchèque et USA. Les résultats de ce projet ont été publiés dans le livre Teachers Talking about their Classrooms. Learning from the Professional Lexicons of Mathematics Teachers around the World, édité par Carmel Mesiti, Michèle Artigue, Hilary Hollingsworth, Yiming Cao et David Clarke et publié par Routledge en 2021
