177 research outputs found

    Qu\u27est-ce qui fait la valeur des bibliothĂšques ? Livre blanc

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    Cette publication clĂŽt le travail d\u27une annĂ©e rĂ©alisĂ© par les experts de la commission de normalisation en Information et Documentation dĂ©diĂ©e Ă  la QualitĂ©, statistiques et Ă©valuation des rĂ©sultats, et a pour but de mettre en lumiĂšre la norme internationale ISO 16439 intitulĂ©e « Methods and procedures for assessing the impact of libraries » dont la premiĂšre Ă©dition est parue en avril 2014. Cette nouvelle norme a pour objectif principal de proposer aux bibliothĂšques, Ă©tablissements et pouvoirs publics des mĂ©thodes et des outils susceptibles de fournir une approche de l’impact qu\u27exercent les bibliothĂšques sur la sociĂ©tĂ© et les individus

    Infrared Radiofluorescence (IR-RF) of K-Feldspar:An Interlaboratory Comparison

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    Infrared Radiofluorescence (IR-RF) is a relatively new method for dosimetric dating of the depositional timing of sediments. This contribution presents an interlaboratory comparison of IR-RF measurements of sedimentary feldspar from eight laboratories. A comparison of the variability of instrumental background, bleaching, saturation, and initial rise behaviour of the IR-RF signal was carried out. Two endmember samples, a naturally bleached modern dune sand sample with a zero dose and a naturally saturated sample from a Triassic sandstone (~250 Ma), were used for this interlaboratory comparison. The major findings of this study are that (1) the observed IR-RF signal keeps decreasing beyond 4000 Gy, (2) the saturated sample gives an apparent palaeodose of 1265 ± 329 Gy and (3) in most cases, the natural IR-RF signal of the modern analogue sample (resulting from natural bleaching) is higher than the signal from laboratory-induced bleaching of 6 h, using a solar simulator (SLS). In other words, the laboratory sample bleaching was unable to achieve the level of natural bleaching. The results of the investigations are discussed in detail, along with possible explanations

    Infrared radiofluorescence (IR-RF) dating:A review

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    International audienceLuminescence dating methods on natural minerals such as quartz and feldspars are indispensable for establishing chronologies in Quaternary Science. Commonly applied sediment dating methods are optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). In 1999, Trautmann et al. (1999a, b) proposed a new related technique called infrared radiofluorescence (IR-RF). IR-RF denotes the infrared luminescence signal of feldspar resulting from exposure to ionizing radiation and potentially offers a significant methodological advance compared to OSL and IRSL regarding luminescence signal stability, dating range and required measurement time. The method has rarely been applied due to a lack of commercially available measurement equipment but experienced a revival during the last years. The present article provides a state-of-the-art overview of the physical background of IR-RF, its challenges, applications and the potential as a dating method. The paper particularly addresses practical considerations for applying IR-RF dating, including signal bleachability and saturation behaviour, and summarizes proposed solutions

    Alix is required for activity-dependent bulk endocytosis at brain synapses

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    In chemical synapses undergoing high frequency stimulation, vesicle components can be retrieved from the plasma membrane via a clathrin-independent process called activitydependent bulk endocytosis (ADBE). Alix (ALG-2-interacting protein X/PDCD6IP) is an adaptor protein binding to ESCRT and endophilin-A proteins which is required for clathrinindependent endocytosis in fibroblasts. Alix is expressed in neurons and concentrates at synapses during epileptic seizures. Here, we used cultured neurons to show that Alix is recruited to presynapses where it interacts with and concentrates endophilin-A during conditions triggering ADBE. Using Alix knockout (ko) neurons, we showed that this recruitment, which requires interaction with the calcium-binding protein ALG-2, is necessary for ADBE. We also found that presynaptic compartments of Alix ko hippocampi display subtle morphological defects compatible with flawed synaptic activity and plasticity detected electrophysiologically. Furthermore, mice lacking Alix in the forebrain undergo less seizures during kainate-induced status epilepticus and reduced propagation of the epileptiform activity. These results thus show that impairment of ADBE due to the lack of neuronal Alix leads to abnormal synaptic recovery during physiological or pathological repeated stimulations

    Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower RhĂŽne Valley, France

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    On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower RhĂŽne Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional CĂ©venne fault system in a context of present-day compressional tectonics

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Impact sur les délais de prise en charge et les durées de séjour au Service des urgences adultes d'un tandem médico-infirmiers de supervision

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    Introduction: La surcharge des services d'urgence (SU) engendre un retard diagnostic, thérapeutique et des séjours prolongés. La mise en place d'un tandem médico-infirmier ayant pour rÎle d'identifier les patients à risque de séjour prolongé et d'accélérer l'orientation pourrait remédier à ceci. Objectif/Méthode: Evaluer l'impact d'un tel tandem sur les délais d'installation et la durée de séjour selon un dessin "avant-aprÚs". Résultats: La mise en place du tandem médico-infirmier a permis une réduction des durées de séjour dans les boxes du SU de 29 minutes. Les durées de séjour totale et en salle d'attente ont également été réduites de 32 et 24 minutes respectivement. La proportion de patient pris en charge dans les délais imposés par notre systÚme de tri a augmenté de 17%. Conclusion: Une équipe de supervision opérationnelle du SU a permis d'améliorer significativement le flux en réduisant les durées de séjour

    Support pédagogiques et éducatifs : projet çATED

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