Transferrin receptor 1 is a reticulocyte-specific receptor for Plasmodium vivax.

Plasmodium vivax shows a strict host tropism for reticulocytes. We identified transferrin receptor 1 (TfR1) as the receptor for P. vivax reticulocyte-binding protein 2b (PvRBP2b). We determined the structure of the N-terminal domain of PvRBP2b involved in red blood cell binding, elucidating the molecular basis for TfR1 recognition. We validated TfR1 as the biological target of PvRBP2b engagement by means of TfR1 expression knockdown analysis. TfR1 mutant cells deficient in PvRBP2b binding were refractory to invasion of P. vivax but not to invasion of P. falciparum Using Brazilian and Thai clinical isolates, we show that PvRBP2b monoclonal antibodies that inhibit reticulocyte binding also block P. vivax entry into reticulocytes. These data show that TfR1-PvRBP2b invasion pathway is critical for the recognition of reticulocytes during P. vivax invasion

Contribution du management socio-économique à la conduite de l’action publique dans un monde en mutation (Chapitre 51)

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La Porte de Mars à Reims : photogrammétrie et SIG, mise en place d’un Document Unique multi études

Le théâtre antique d’Orange SIG et HBIM, Journées d’étude organisées par l’Institut de Recherche sur l’Architecture Antique avec le soutien de la Fondation A*MidexLa création d’un document unique de travail sur la porte de Mars de Reims découle de la mise en œuvre d’un projet de restauration de l’édifice, réalisé en plusieurs phases successives dont la principale doit débuter dans le courant de cette année 2021. Sa réalisation, encore en cours, est rendue complexe par la multiplicité des acteurs impliqués dans le projet et de leurs attentes. Cette expérience illustre ainsi l’importance de bien cerner les attentes de chaque partenaire en amont du démarrage du projet et de bien maîtriser les outils techniques afin de répondre au mieux à celles-ci. Au préalable, les fouilles archéologiques menées au pied de l’édifice et la surveillance de la restauration de sa couverture ont permis de renouveler sa connaissance, chose rare pour un édifice en coeur de ville. Cette étude commanditée par la ville de Reims, est au niveau d’un projet collectif de recherches qui réunit en principaux acteurs : le Service archéologique du Grand Reims, le Groupe d’Étude sur les Géomatériaux et Environnements Naturels, Anthropiques et Archéologiques (EA3795) et l’Institut National de Recherche en Archéologie Préventive. Les différentesétudes menées sur ce monument emblématique de l’Est de la Gaule ont été la détermination pétrographique et géologique de toutes les pierres de l’édifice, l’identification et la synthèse de toutes les phases de restaurations, l’étude architecturale et l’analyse stylistique, mais aussi un énorme travail à partir du modèle photogrammétrique fourni. L’implication des acteurs et la coordination d’ensemble se révèlent également primordiales pour aboutir à un résultat répondant aux différents objectifs. Les retours d’expérience montrent qu’il devient nécessaire de mettre en place des plates-formes collaboratives en ligne pour permettre de l’édition et du versioning. Le web SIG et Git pourraient représenter des pistes qui répondraient à ces attentes

La Porte de Mars à Reims : photogrammétrie et SIG, mise en place d'un Document Unique pluridisciplinaire

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Polarisation of Electron Density and Electronic Effects: Revisiting the Carbon–Halogen Bonds

International audienceElectronic effects (inductive and mesomeric) are of fundamental importance to understand the reactivity and selectivity of a molecule. In this article, polarisation temperature is used as a principal index to describe how electronic effects propagate in halogeno-alkanes and halogeno-alkenes. It is found that as chain length increases, polarisation temperature decreases. As expected, polarisation is much larger for alkenes than for alkanes. Finally, the polarisation mode of the carbon–fluorine bond is found to be quite different and might explain the unusual reactivity of fluoride compounds

Missing critical auditory alarms in aeronautics: evidence for inattentional deafness?

The inability of pilots to detect unexpected changes in the environment (e.g., auditory alarms) is a critical problem in aeronautics. The lack of response to alarms is not thought to be a perceptual/attentional issue, but rather that pilots choose to ignore such warnings due to cognitive biases. In the current paper we consider an alternative explanation, by extending the phenomenon of inattentional deafness to aeronautics. Fourteen pilots equipped with an eye tracker and an electrocardiogram performed landings in a flight simulator. During the critical landing, an auditory landing gear alarm was triggered while the volunteers also faced a windshear. Eight out of 14 pilots did not report the occurrence of the critical alarm during the debriefing. Interestingly, all but one of these ‘deaf’ pilots failed to perform the adequate go-around behavior. These findings establish inattentional deafness as a cognitive phenomenon that is critical for air safety

Apical size and deltaA expression predict adult neural stem cell decisions along lineage progression

Posted December 26, 2022 on bioRxiv.The maintenance of neural stem cells (NSCs) in the adult brain depends on their activation frequency and division mode. We use long-term intravital imaging of NSCs in the zebrafish adult telencephalon to link activation and division mode with predictive cellular and molecular parameters. We reveal that apical surface area and expression of the Notch ligand DeltaA predict NSC activation frequency, while deltaA expression marks NSC commitment to neurogenesis. We also find that deltaA -negative NSCs constitute the bona fide self-renewing NSC pool and systematically engage in asymmetric divisions generating a self-renewing deltaA neg and a neurogenic deltaA pos NSC. Finally, modulation of Notch signaling during imaging indicates that the prediction of activation frequency by apical size, and the asymmetric divisions of deltaA neg NSCs, are functionally independent of Notch. These results provide dynamic qualitative and quantitative readouts of NSC lineage progression in vivo and support a hierarchical organization of NSCs in differently fated sub-populations

Apical size and deltaA expression predict adult neural stem cell decisions along lineage progression

Posted December 26, 2022 on bioRxiv.The maintenance of neural stem cells (NSCs) in the adult brain depends on their activation frequency and division mode. We use long-term intravital imaging of NSCs in the zebrafish adult telencephalon to link activation and division mode with predictive cellular and molecular parameters. We reveal that apical surface area and expression of the Notch ligand DeltaA predict NSC activation frequency, while deltaA expression marks NSC commitment to neurogenesis. We also find that deltaA -negative NSCs constitute the bona fide self-renewing NSC pool and systematically engage in asymmetric divisions generating a self-renewing deltaA neg and a neurogenic deltaA pos NSC. Finally, modulation of Notch signaling during imaging indicates that the prediction of activation frequency by apical size, and the asymmetric divisions of deltaA neg NSCs, are functionally independent of Notch. These results provide dynamic qualitative and quantitative readouts of NSC lineage progression in vivo and support a hierarchical organization of NSCs in differently fated sub-populations

Longitudinal IgG antibody responses to Plasmodium vivax blood-stage antigens during and after acute vivax malaria in individuals living in the Brazilian Amazon.

Funder: CAPES doctoral fellowshipFunder: Michael J. Fox FoundationFunder: CNPq senior research fellowshipBACKGROUND: To make progress towards malaria elimination, a highly effective vaccine targeting Plasmodium vivax is urgently needed. Evaluating the kinetics of natural antibody responses to vaccine candidate antigens after acute vivax malaria can inform the design of serological markers of exposure and vaccines. METHODOLOGY/PRINCIPAL FINDINGS: The responses of IgG antibodies to 9 P. vivax vaccine candidate antigens were evaluated in longitudinal serum samples from Brazilian individuals collected at the time of acute vivax malaria and 30, 60, and 180 days afterwards. Antigen-specific IgG correlations, seroprevalence, and half-lives were determined for each antigen using the longitudinal data. Antibody reactivities against Pv41 and PVX_081550 strongly correlated with each other at each of the four time points. The analysis identified robust responses in terms of magnitude and seroprevalence against Pv41 and PvGAMA at 30 and 60 days. Among the 8 P. vivax antigens demonstrating >50% seropositivity across all individuals, antibodies specific to PVX_081550 had the longest half-life (100 days; 95% CI, 83-130 days), followed by PvRBP2b (91 days; 95% CI, 76-110 days) and Pv12 (82 days; 95% CI, 64-110 days). CONCLUSION/SIGNIFICANCE: This study provides an in-depth assessment of the kinetics of antibody responses to key vaccine candidate antigens in Brazilians with acute vivax malaria. Follow-up studies are needed to determine whether the longer-lived antibody responses induced by natural infection are effective in controlling blood-stage infection and mediating clinical protection