Stability and asymptotic properties of a linearized hydrodynamic medium model for dispersive media in nanophotonics

We analyze the stability of a linearized hydrodynamical model describing the response of nanometric dispersive metallic materials illuminated by optical light waves that is the situation occurring in nanoplasmonics. This model corresponds to the coupling between the Maxwell system and a PDE describing the evolution of the polarization current of the electrons in the metal. We show the well posedness of the system, polynomial stability and optimal energy decay rate. We also investigate the numerical stability for a discontinuous Galerkin type approximation and several explicit time integration schemes.

Stability and asymptotic properties of a linearized hydrodynamic medium model for dispersive media in nanophotonics

International audienceWe analyze the stability of a linearized hydrodynamical model describing the response of nanometric dispersive metallic materials illuminated by optical light waves that is the situation occurring in nanoplasmonics. This model corresponds to the coupling between the Maxwell system and a PDE describing the evolution of the polarization current of the electrons in the metal. We show the well posedness of the system, polynomial stability and optimal energy decay rate. We also investigate the numerical stability for a discontinuous Galerkin type approximation and several explicit time integration schemes.

Key contribution of eIF4H-mediated translational control in tumor promotion.

Dysregulated expression of translation initiation factors has been associated with carcinogenesis, but underlying mechanisms remains to be fully understood. Here we show that eIF4H (eukaryotic translation initiation factor 4H), an activator of the RNA helicase eIF4A, is overexpressed in lung carcinomas and predictive of response to chemotherapy. In lung cancer cells, depletion of eIF4H enhances sensitization to chemotherapy, decreases cell migration and inhibits tumor growth in vivo, in association with reduced translation of mRNA encoding cell-proliferation (c-Myc, cyclin D1) angiogenic (FGF-2) and anti-apoptotic factors (CIAP-1, BCL-xL). Conversely, each isoform of eIF4H acts as an oncogene in NIH3T3 cells by stimulating transformation, invasion, tumor growth and resistance to drug-induced apoptosis together with increased translation of IRES-containing or structured 5'UTR mRNAs. These results demonstrate that eIF4H plays a crucial role in translational control and can promote cellular transformation by preferentially regulating the translation of potent growth and survival factor mRNAs, indicating that eIF4H is a promising new molecular target for cancer therapy

Overtime in Europe : regulation and practice

Aquest informe s'elabora a partir de les diferents contribucions de la Network of Eurofound Correspondents, i pel que fa a Espanya la contribució ha estat de l'ALejandro GodinoDespite the well-known adverse effects of regular long working hours on workers' health, well-being and performance, many workers in the EU continue to work beyond their normal hours. Part of this additional working time is classified as overtime. This report takes a comparative overview of how overtime is regulated in the EU Member States, Norway and the United Kingdom, including its definition, the limits on its use and the compensation received by workers for working extra hours. The report assesses the extent of the phenomenon using national-level data, delves into the factors that explain it, and examines the potential consequences for workers and firms. Finally, the report summarises the current debate on the topic, as uncompensated working hours, structural overtime and monitoring of working hours are currently some of the most discussed work-related issues across the EU

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Stability properties for a problem of light scattering in a dispersive metallic domain

In this work, we study the well-posedness and some stability properties of a PDE system that models the propagation of light in a metallic domain with a hole. This model takes into account the dispersive properties of the metal. It consists of a linear coupling between Maxwell's equations and a wave type system. We prove that the problem is well posed for several types of boundary conditions. Furthermore, we show that it is polynomially stable and that the exponential stability is conditional on the exponential stability of the Maxwell system

Utilisation du sévoflurane pour l'intubation du nouveau-né

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Measuring coarse grain deformation by digital image correlation

International audienceThis work presents results from oedometric compression of coarse granular material. Coarse granular media exhibit significant deformations making it complicated to predict the settlement of structures. In this paper, a measurement technique was developed for the analysis of two-dimensional (2D) images of a deforming coarse granular medium to investigate its deformation. This was achieved by realizing grainbased image correlation to measure the grain transformation in gravel with the use of a Digital Image Correlation technique. The 2D displacement fields enable us to explore the behaviour of granular media at different scales: microscopic, mesoscopic, and macroscopic scales. The mesoscopic scale is defined from branches that connect the centres of three neighbouring grains, using a Delaunay triangulation to account for an equivalent continuum media. While the consistency of the macroscopic strain and the average mesoscopic strain is assessed, it is shown that a deviation from the normalized microscopic vertical displacement is an indicator of the heterogeneity of the mesoscopic strain field. The proposed mesoscopic analysis allows us to investigate these heterogeneities. Another important result is that even if the amplitude of the microscopic strain is small (approximately 100 times smaller) compared with the other strain measures, it confirms that the grains are not rigid and that their ultimate strain can be estimated using the proposed approach

Voir et faire voir les graphes de réseaux personnels : questions d’éthique réflexive sur les effets de protocoles de recherche

International audiencePersonal network analysis studies an individual’s social relationships, and increasingly uses the visualization of these networks in fieldwork settings. However, seeing one’s personal network objectified in an image does not leave a person unchanged. Building on two different research protocols, this article discusses some of the reactions induced by the co-construction of the personal network using visualizations and examines the impacts of researcher-respondent interactions on the final results assimilation. The issues at stake are ethical, insofar as they concern the fate of others in the broadest sense, beyond compliance with formal rules. We harness reflexivity as a means of learning from our own research experiences, respectively in the fields of entrepreneurship and mental health. The article thus contributes to a wider debate on research ethics in sociology, which encompasses impacts and which, we believe, requires the active participation of researchers from the field.L'analyse des réseaux personnels étudie les relations sociales des individus et utilise de plus en plus la visualisation de ces réseaux en situation d'enquête. Cependant, le fait de voir son réseau objectivé dans une image ne laisse pas une personne inchangée. S'appuyant sur deux protocoles de recherche différents, cet article présente quelques réactions que suscite la co-construction du réseau personnel à l'aide de visualisations et examine l'impact de l'interaction entre personnes enquêtrices et enquêtées dans l'appropriation des résultats finaux. Les enjeux sont éthiques, dans la mesure où ils concernent le sort d'autrui au sens large, au-delà du respect des règles formelles. Nous mobilisons la réflexivité comme un moyen d'apprendre de nos propres expériences de recherche dans les domaines de l'entrepreneuriat et de la santé mentale respectivement. L'article contribue ainsi à un débat plus large sur l'éthique de la recherche en sociologie, qui englobe les impacts et qui, nous croyons, nécessite la participation active des chercheurs et chercheuses de terrai

Induction of FOXP3-expressing regulatory CD4pos T cells by human mature autologous dendritic cells

Current literature suggests that T cells recognizing antigen on mature dendritic cells (DC) differentiate into effector T cells whereas tolerance is induced when antigen is presented by immature DC. We investigated the consequences of the interactions between immature or lipopolysaccharide-matured DC and CD4pos T lymphocytes in absence of foreign antigen. While immature DC did not induce significant CD4pos T cell activation, we observed that a significant fraction of CD4pos T cells cultured with mature autologous DC displayed phenotypic features of activation and produced IL-2, IFN- + ,IL-10 and TGF- g .Furthermore, CD4pos T lymphocytes primed by mature, but not immature, autologous DC acquired regulatory properties. Indeed, when added to an allogeneic mixed leukocyte reaction, they suppressed the response of alloreactive T lymphocytes to the priming DC while responses to third-party stimulators were spared. The generation of CD4pos T cells with regulatory function by autologous stimulation did not require the presence of natural CD4posCD25pos regulatory T cells. In addition, the acquisition of regulatory function by CD4posCD25neg T cells stimulated by autologous mature DC was accompanied by the induction of FOXP3 expression. Our data suggest that during inflammatory conditions, presentation of self antigens by mature DC to autologous T lymphocytes could contribute to the generation of regulatory mechanisms.FLWINinfo:eu-repo/semantics/publishe