Effects of long-term endogenous corticosteroid exposure on brain volume and glial cells in the AdKO mouse

Chronic exposure to high circulating levels of glucocorticoids has detrimental effects on health, including metabolic abnormalities, as exemplified in Cushing's syndrome (CS). Magnetic resonance imaging (MRI) studies have found volumetric changes in gray and white matter of the brain in CS patients during the course of active disease, but also in remission. In order to explore this further, we performed MRI-based brain volumetric analyses in the AdKO mouse model for CS, which presents its key traits. AdKO mice had reduced relative volumes in several brain regions, including the corpus callosum and cortical areas. The medial amygdala, bed nucleus of the stria terminalis, and hypothalamus were increased in relative volume. Furthermore, we found a lower immunoreactivity of myelin basic protein (MBP, an oligodendrocyte marker) in several brain regions but a paradoxically increased MBP signal in the male cingulate cortex. We also observed a decrease in the expression of glial fibrillary acidic protein (GFAP, a marker for reactive astrocytes) and ionized calcium-binding adapter molecule 1 (IBA1, a marker for activated microglia) in the cingulate regions of the anterior corpus callosum and the hippocampus. We conclude that long-term hypercorticosteronemia induced brain region-specific changes that might include aberrant myelination and a degree of white matter damage, as both repair (GFAP) and immune (IBA1) responses are decreased. These findings suggest a cause for the changes observed in the brains of human patients and serve as a background for further exploration of their subcellular and molecular mechanisms.Neuro Imaging Researc

Second Language Tutoring Using Social Robots: A Large-Scale Study

We present a large-scale study of a series of seven lessons designed to help young children learn English vocabulary as a foreign language using a social robot. The experiment was designed to investigate 1) the effectiveness of a social robot teaching children new words over the course of multiple interactions (supported by a tablet), 2) the added benefit of a robot's iconic gestures on word learning and retention, and 3) the effect of learning from a robot tutor accompanied by a tablet versus learning from a tablet application alone. For reasons of transparency, the research questions, hypotheses and methods were preregistered. With a sample size of 194 children, our study was statistically well-powered. Our findings demonstrate that children are able to acquire and retain English vocabulary words taught by a robot tutor to a similar extent as when they are taught by a tablet application. In addition, we found no beneficial effect of a robot's iconic gestures on learning gains

Predictors of hospital discharge and mortality in patients with diabetes and COVID-19: updated results from the nationwide CORONADO study

AIMS/HYPOTHESIS: This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19). METHODS: The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days. RESULTS: We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m(2). Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors. CONCLUSIONS/INTERPRETATION: In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04324736

Guidelines for Designing Social Robots as Second Language Tutors

In recent years, it has been suggested that social robots have potential as tutors and educators for both children and adults. While robots have been shown to be effective in teaching knowledge and skill-based topics, we wish to explore how social robots can be used to tutor a second language to young children. As language learning relies on situated, grounded and social learning, in which interaction and repeated practice are central, social robots hold promise as educational tools for supporting second language learning. This paper surveys the developmental psychology of second language learning and suggests an agenda to study how core concepts of second language learning can be taught by a social robot. It suggests guidelines for designing robot tutors based on observations of second language learning in human–human scenarios, various technical aspects and early studies regarding the effectiveness of social robots as second language tutors

Stratégie des demandes de formation d'éducateurs spécialisés selon leur statut (d'étudiant ou de professionnel) et leur position par rapport à l'institution de formation (de candidat ou d'élève)

Pithon Gérard, Montanier J., Moutou C., Fambon P. Stratégie des demandes de formation d'éducateurs spécialisés selon leur statut (d'étudiant ou de professionnel) et leur position par rapport à l'institution de formation (de candidat ou d'élève). In: Langage et société, supplément au n°9, 1979. Sociétés dominées, pratiques langagières dominées et stratégies alternatives. pp. 107-112

Enzymatic degradation of semi-dilute polymer solutions: coupling between enzyme mobility and activity

International audienceBiodegradable polymers (synthetic or natural) can be degraded by the action of living organisms. In most cases, biodegradation occurs through enzyme-catalysed depolymerisation, where enzymes hydrolyse bonds along the polymer chains. Lignocellulosic biomass (LC) is one of the most abundant renewable polymers that, when degraded, represents a tremendous source of interesting products. However, LC is difficult to degrade because plant cell wall polysaccharides are structurally and chemically complex molecules, forming a heterogeneous network of varying density and porosity. During industrial degradation, enzymes are confronted with LC substrates (e.g. wheat straws) that are insoluble and partially hydrated. They penetrate and propagate in the material, while at the same time changing its properties through hydrolysis. Although fascinating, little is known about the coupling between enzyme activity and mobility in the context of dense polymeric systems. In extremely tight polymer networks, the coupling is obvious: enzymes cannot just enter the polymer mesh and consequently move by 'eroding' the polymer surface [1]. In the more general case, enzymes can enter the network, but their activity is affected by the restricted diffusion in the polymer mesh [2]. Nevertheless, studies only consider the impact of the concentration of the polymer, neglecting its structural and dynamical evolution with hydrolysis time [3]; two characteristics that must have an effect on enzyme propagation in the material. Here we explore the coupling between enzyme mobility and activity by using a model polymer, arabinoxylan, extracted from wheat LC and a fluorescently labelled enzyme. We prepare semi-dilute polymer solutions that are concentrated at different mesh sizes. Then, the radial diffusion of the enzymes is observed using fluorescent microscopy. We present the results obtained with catalytically active and inactive enzymes. To complement these results, we present ex-situ experiments aiming at characterizing the polymer during the degradation (viscometry, SEC-MALS)

Grafting of proteins onto polymeric surfaces: A synthesis and characterization challenge

This review aims at answering the following question: how can a researcher be sure to succeed in grafting a protein onto a polymer surface? Even if protein immobilization on solid supports has been used industrially for a long time, hence enabling natural enzymes to serve as a powerful tool, emergence of new supports such as polymeric surfaces for the development of so-called intelligent materials requires new approaches. In this review, we introduce the challenges in grafting protein on synthetic polymers, mainly because compared to hard surfaces, polymers may be sensitive to various aqueous media, depending on the pH or reductive molecules, or may exhibit state transitions with temperature. Then, the specificity of grafting on synthetic polymers due to difference of chemical functions availability or difference of physical properties are summarized. We present next the various available routes to covalently bond the protein onto the polymeric substrates considering the functional groups coming from the monomers used during polymerization reaction or post-modification of the surfaces. We also focus our review on a major concern of grafting protein, which is avoiding the potential loss of function of the immobilized protein. Meanwhile, this review considers the different methods of characterization used to determine the grafting efficiency but also the behavior of enzymes once grafted. We finally dedicate the last part of this review to industrial application and future prospective, considering the sustainable processes based on green chemistry