Comprendre l’impact de la culture et des valeurs sur les comportements économiques

Yann Algan mène des recherches en économie expérimentale et comportementale à Sciences Po où il enseigne principalement la macroéconomie et la politique économique. Il répond ici aux questions de nonfiction.fr dans le cadre d’un dossier consacré aux nouveaux économistes français

Land Surface Indicators from Space: Methodology and Preliminary Results

This document overviews the content and the preliminary results of a specific work package entitled Land Surface Indicators from Space of the Land Use and Landscapes from the Joint Research Center (JRC) and the European Environment Agency (EEA) 2006 work plan described in Kennedy and Stanners (2005). The first section summarizes the objectives of the activities in the context of the EEA project Land and Ecosystems Accounts. The main goal is the estimate and the analysis of the Net Primary Productivity (NPP) over terrestrial surfaces from space remote sensing products over various land cover types in Europe. The Knorr and Heimann (1995)'s model is applied to compute the NPP using the current JRC- Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) products as input. This simple generic global biosphere model requires also the downward photosynthetic active radiation (PAR) at the surface level. Sections 3, 4 and 5 outline the model, identify the sources of input data stream, and present preliminary results over European countries, respectively. Concluding remarks and perspectives are then given at the end of the document.JRC.H.3-Global environement monitorin

MERIS Level 3 Land Surface Aggregated Products Description

This document describes the format of the products of the Medium Resolution Imaging Spectrometer (MERIS) Level 3 aggregated products. These data are operationally processed and produced at the Grid Processing-on-Demand (G-POD) of European Space Research INstitute (ESRIN) using the European Commission – DG Joint Research Centre (JRC) algorithm and software.JRC.H.3-Global environement monitorin

HIV envelope V3 region mimic embodies key features of a broadly neutralizing antibody lineage epitope

HIV-1 envelope (Env) mimetics are candidate components of prophylactic vaccines and potential therapeutics. Here we use a synthetic V3-glycopeptide (“Man9-V3”) for structural studies of an HIV Env third variable loop (V3)-glycan directed, broadly neutralizing antibody (bnAb) lineage (“DH270”), to visualize the epitope on Env and to study how affinity maturation of the lineage proceeded. Unlike many previous V3 mimetics, Man9-V3 encompasses two key features of the V3 region recognized by V3-glycan bnAbs—the conserved GDIR motif and the N332 glycan. In our structure of an antibody fragment of a lineage member, DH270.6, in complex with the V3 glycopeptide, the conformation of the antibody-bound glycopeptide conforms closely to that of the corresponding segment in an intact HIV-1 Env trimer. An additional structure identifies roles for two critical mutations in the development of breadth. The results suggest a strategy for use of a V3 glycopeptide as a vaccine immunogen

Estimating Plasma Glucose from Interstitial Glucose: The Issue of Calibration Algorithms in Commercial Continuous Glucose Monitoring Devices

Evaluation of metabolic control of diabetic people has been classically performed measuring glucose concentrations in blood samples. Due to the potential improvement it offers in diabetes care, continuous glucose monitoring (CGM) in the subcutaneous tissue is gaining popularity among both patients and physicians. However, devices for CGM measure glucose concentration in compartments other than blood, usually the interstitial space. This means that CGM need calibration against blood glucose values, and the accuracy of the estimation of blood glucose will also depend on the calibration algorithm. The complexity of the relationship between glucose dynamics in blood and the interstitial space, contrasts with the simplistic approach of calibration algorithms currently implemented in commercial CGM devices, translating in suboptimal accuracy. The present review will analyze the issue of calibration algorithms for CGM, focusing exclusively on the commercially available glucose sensors

Uridine Metabolism in HIV-1-Infected Patients: Effect of Infection, of Antiretroviral Therapy and of HIV-1/ART-Associated Lipodystrophy Syndrome

Background Uridine has been advocated for the treatment of HIV-1/HAART-associated lipodystrophy (HALS), although its metabolism in HIV-1-infected patients is poorly understood. Methods Plasma uridine concentrations were measured in 35 controls and 221 HIV-1-infected patients and fat uridine in 15 controls and 19 patients. The diagnosis of HALS was performed following the criteria of the Lipodystrophy Severity Grading Scale. Uridine was measured by a binary gradient-elution HPLC method. Analysis of genes encoding uridine metabolizing enzymes in fat was performed with TaqMan RT-PCR. Results Median plasma uridine concentrations for HIV-1-infected patients were 3.80 µmol/l (interquartile range: 1.60), and for controls 4.60 µmol/l (IQR: 1.8) (P = 0.0009). In fat, they were of 6.0 (3.67), and 2.8 (4.65) nmol/mg of protein, respectively (P = 0.0118). Patients with a mixed HALS form had a median plasma uridine level of 4.0 (IC95%: 3.40-4.80) whereas in those with isolated lipoatrophy it was 3.25 (2.55-4.15) µmol/l/l (P = 0.0066). The expression of uridine cytidine kinase and uridine phosphorylase genes was significantly decreased in all groups of patients with respect to controls. A higher expression of the mRNAs for concentrative nucleoside transporters was found in HIV-1-infected patients with respect to healthy controls. Conclusions HIV-1 infection is associated with a decrease in plasma uridine and a shift of uridine to the adipose tissue compartment. Antiretroviral therapy was not associated with plasma uridine concentrations, but pure lipoatrophic HALS was associated with significantly lower plasma uridine concentrations

Staged induction of HIV-1 glycan–dependent broadly neutralizing antibodies

A preventive HIV-1 vaccine should induce HIV-1–specific broadly neutralizing antibodies (bnAbs). However, bnAbs generally require high levels of somatic hypermutation (SHM) to acquire breadth, and current vaccine strategies have not been successful in inducing bnAbs. Because bnAbs directed against a glycosylated site adjacent to the third variable loop (V3) of the HIV-1 envelope protein require limited SHM, the V3-glycan epitope is an attractive vaccine target. By studying the cooperation among multiple V3-glycan B cell lineages and their coevolution with autologous virus throughout 5 years of infection, we identify key events in the ontogeny of a V3-glycan bnAb. Two autologous neutralizing antibody lineages selected for virus escape mutations and consequently allowed initiation and affinity maturation of a V3-glycan bnAb lineage. The nucleotide substitution required to initiate the bnAb lineage occurred at a low-probability site for activation-induced cytidine deaminase activity. Cooperation of B cell lineages and an improbable mutation critical for bnAb activity defined the necessary events leading to breadth in this V3-glycan bnAb lineage. These findings may, in part, explain why initiation of V3-glycan bnAbs is rare, and suggest an immunization strategy for inducing similar V3-glycan bnAbs

The role of resveratrol on skeletal muscle cell differentiation and myotube hypertrophy during glucose restriction

Glucose restriction (GR) impairs muscle cell differentiation and evokes myotube atrophy. Resveratrol treatment in skeletal muscle cells improves inflammatory-induced reductions in skeletal muscle cell differentiation. We therefore hypothesised that resveratrol treatment would improve muscle cell differentiation and myotube hypertrophy in differentiating C2C12 myoblasts and mature myotubes during GR. Glucose restriction at 0.6 g/L (3.3 mM) blocked differentiation and myotube hypertrophy versus high-glucose (4.5 g/L or 25 mM) differentiation media (DM) conditions universally used for myoblast culture. Resveratrol (10 μM) treatment increased SIRT1 phosphorylation in DM conditions, yet did not improve differentiation when administered to differentiating myoblasts in GR conditions. Resveratrol did evoke increases in hypertrophy of mature myotubes under DM conditions with corresponding elevated Igf-I and Myhc7 gene expression, coding for the ‘slow’ type I MYHC protein isoform. Inhibition of SIRT1 via EX-527 administration (100 nM) also reduced myotube diameter and area in DM conditions and resulted in lower gene expression of Myhc 1, 2 and 4 coding for ‘intermediate’ and ‘faster’ IIx, IIa and IIb protein isoforms, respectively. Resveratrol treatment did not appear to modulate phosphorylation of energy-sensing protein AMPK or protein translation initiator P70S6K. Importantly, in mature myotubes, resveratrol treatment was able to ameliorate reduced myotube growth in GR conditions over an acute 24-h period, but not over 48–72 h. Overall, resveratrol evoked myotube hypertrophy in DM conditions while favouring ‘slower’ Myhc gene expression and acutely ameliorated impaired myotube growth observed during glucose restriction

Mimicry of an HIV broadly neutralizing antibody epitope with a synthetic glycopeptide.

CAPRISA, 2017.Abstract available in pdf

Rendre tolérable l’absence de relogement dans l’intervention publique en bidonville, à Mayotte

International audienceComment l’exceptionnalité des normes qui caractérise l’action publique en bidonville en France métropolitaine se décline-t-elle dans les territoires ultramarins français, où le droit commun se trouve constamment négocié au nom de particularités locales ? Cet article se propose de répondre à cette question à partir de l’analyse de l’évacuation d’un bidonville conduite à Mayotte en 2021. Dans le cas étudié, cette exceptionnalité prend la forme du détournement d’un instrument d’action publique issu du champ migratoire et sécuritaire au profit d’un projet urbain. Dans les discours des acteurs communaux demandeurs de cette opération, ce choix et donc l’absence de relogement temporaire des occupants qui en découle sont justifiés par une double spécificité : celle du territoire, qui réside dans la faiblesse des capacités institutionnelles locales (manque d’ingénierie, absence de ressources en logement temporaire, défaillances du secteur privé), et celle des occupants, construite à travers un prisme ethnicisant