Nitrogen isotopic fractionation during abiotic synthesis of organic solid particles

The formation of organic compounds is generally assumed to result from abiotic processes in the Solar System, with the exception of biogenic organics on Earth. Nitrogen-bearing organics are of particular interest, notably for prebiotic perspectives but also for overall comprehension of organic formation in the young solar system and in planetary atmospheres. We have investigated abiotic synthesis of organics upon plasma discharge, with special attention to N isotope fractionation. Organic aerosols were synthesized from N2-CH4 and N2-CO gaseous mixtures using low-pressure plasma discharge experiments, aimed at simulating chemistry occurring in Titan s atmosphere and in the protosolar nebula, respectively. Nitrogen is efficiently incorporated into the synthesized solids, independently of the oxidation degree, of the N2 content of the starting gas mixture, and of the nitrogen speciation in the aerosols. The aerosols are depleted in 15N by 15-25 permil relative to the initial N2 gas, whatever the experimental setup is. Such an isotopic fractionation is attributed to mass-dependent kinetic effect(s). Nitrogen isotope fractionation upon electric discharge cannot account for the large N isotope variations observed among solar system objects and reservoirs. Extreme N isotope signatures in the solar system are more likely the result of self-shielding during N2 photodissociation, exotic effect during photodissociation of N2 and/or low temperature ion-molecule isotope exchange. Kinetic N isotope fractionation may play a significant role in the Titan s atmosphere. We also suggest that the low delta15N values of Archaean organic matter are partly the result of abiotic synthesis of organics that occurred at that time

Insertion socio-économique de jeunes québécois admis au Canada durant l’enfance en tant que réfugiés

L’étude de la scolarisation et de l’insertion économique des jeunes québécois admis comme réfugiés durant l’enfance révèle des spécificités par rapport aux jeunes natifs et aux autres jeunes issus de l’immigration. Bien qu’un peu plus scolarisés que les jeunes natifs, ils pâtissent d’un risque de chômage accru et d'un revenu d'emploi moins élevé. Toutefois, l’origine de ces inégalités réside moins dans leur statut de réfugiés que dans leur appartenance à certaines minorités racisées. Ainsi, leur trajectoire dans l’emploi contribue à mettre au jour certaines formes de discriminations sur le marché du travail québécois

The End of The Digital Generation Gap

It is commonly accepted that the more an Information and Communication Technology (ICT) is recent the more it is suitable for young people and unsuitable for older people. However, several facts suggest that this idea is no longer valid and will not be in the future. User-centered design methods are increasingly used in companies, ICT tends to be more and more user-friendly, and it seems that digital natives (or millennials) are not really outdated by the next generations in terms of digital skills. These elements lead us to assume that the digital generation gap may have been a parenthesis in history related to the democratization of the first and complicated computers in the 80s. If generation is no longer a factor of ICT adoption, old age however is still related to sensory and motor impairments. Thus, the issue that is becoming increasingly important for technology designers should be better consideration of accessibility

L'ergonomie de conception prend-elle suffisamment en compte les interactions multi-utilisateurs ? Vers une construction d'outils méthodologiques d'une approche de conception centrée utilisateur pour les technologies multi-utilisateurs

La démarche de conception centrée utilisateur est devenue incontournable afin de s’assurer de l’utilité, de l’acceptation et de l’utilisabilité d’une nouvelle technologie. Néanmoins, l’émergence des technologies collaboratives et multi-utilisateurs (le métavers, la e-santé, l’industrie du futur, les jeux en ligne, l’enseignement à distance, les plateformes de mises en relation, etc.) soulève de nouveaux enjeux de conception auxquels les méthodes et les modèles ne sont pas adaptés. L’usage de ces technologies devient dépendant des attentes qu’ont les utilisateurs les uns par rapport aux autres. Dans ce présent acte, à travers 3 projets de recherche actuellement en cours, nous proposons des pistes de réflexion afin d’élargir la conception centrée utilisateur à ces nouvelles formes d’usages. Ces projets permettront une meilleure prise en compte des enjeux de la conception multi-utilisateur grâce aux développements de nouvelles méthodes, modèles et choix de conception ergonomiques dans un contexte de conception éthique et responsable

Interactive interpretation of structured documents: Application to the recognition of handwritten architectural plans

International audienceThis paper addresses a whole architecture, including the IMISketch method. IMISketch method incorporates two aspects: document analysis and interactivity. This paper describes a global vision of all the parts of the project. IMISketch is a generic method for an interactive interpretation of handwritten sketches. The analysis of complex documents requires the management of uncertainty. While, in practice the similar methods often induce a large combinatorics, IMISketch method presents several optimization strategies to reduce the combinatorics. The goal of these optimizations is to have a time analysis compatible with user expectations. The decision process is able to solicit the user in the case of strong ambiguity: when it is not sure to make the right decision, the user explicitly validates the right decision to avoid a fastidious a posteriori verification phase due to propagation of errors.This interaction requires solving two major problems: how interpretation results will be presented to the user, and how the user will interact with analysis process. We propose to study the effects of those two aspects. The experiments demonstrate that (i) a progressive presentation of the analysis results, (ii) user interventions during it and (iii) the user solicitation by the analysis process are an efficient strategy for the recognition of complex off-line documents.To validate this interactive analysis method, several experiments are reported on off-line handwritten 2D architectural floor plans

Particle-based platforms for malaria vaccines

Recombinant subunit vaccines in general are poor immunogens likely due to the small size of pep-tides and proteins, combined with the lack or reduced presentation of repetitive motifs and missing complementary signal(s) for optimal triggering of the immune response. Therefore, recombinant sub-unit vaccines require enhancement by vaccine delivery vehicles in order to attain adequate protective immunity. Particle-based delivery platforms, including particulate antigens and particulate adjuvants,are promising delivery vehicles for modifying the way in which immunogens are presented to both theinnate and adaptive immune systems. These particle delivery platforms can also co-deliver non-specific immunostimodulators as additional adjuvants. This paper reviews efforts and advances of the Particle-based delivery platforms in development of vaccines against malaria, a disease that claims over 600,000lives per year, most of them are children under 5 years of age in sub-Sahara Africa

Income Inequalities and International Trade in Goods and Services: Short- and Long-Run Evidence

In this article, we study the short- and long-run effects of trade openness in services on wage inequalities. The sample covers ten Organization for Economic Cooperation and Development (OECD) countries from 1980 to 2005. We find a differentiated impact of trade in goods compared to trade in services: while trade in goods has a short- and a long-run impact on inequalities, trade in services has only long-run effects. Moreover, we also find that international trade in services has a stronger impact on inequalities than international trade in goods, and this effect does not concern only inequalities between top incomes and low incomes but also between top incomes and median incomes

Immersive Digital Twins of an Industrial Forge in Engineering Education

The rapid and relentless pace of technological advancement over recent years has had a profound impact on the realm of education. This dynamic transformation has paved the way for a host of new possibilities and innovations that are reshaping the educational landscape. One of the most noteworthy developments within this technological revolution is the advent of virtual and augmented realities. These immersive technologies have become pivotal in shaping the evolution of educational tools and systems across universities worldwide. For examples of this phenomenon, one can refer to recent works such as Sandyk et al. (2023) and Kontio et al. (2023). The "JENII project" is an example of initiative in the sphere of immersive education, which is being spearheaded by the Arts et Metiers Institute of Technology. This project is set on a course to revolutionize engineering education by designing a suite of immersive and interactive digital twins. While Engineering Learning Workplaces are not physically present, the immersion enabled by the technology, when coupled with a machine's digital twin, closely replicates the genuine interaction an engineering student would encounter in an industrial environment. Thus, within the framework of the Conceive-Design-Implement-Operate (CDIO) approach, these immersive digital twins are envisioned as virtual counterparts to the workplaces described in Standard 6. However, immersive digital twins are not static; instead, they offer the prospect of continuous optimization to provide engineering students with a dynamic learning experience. A important attribute of these digital twins is their potential to catalyze Active Learning, a fundamental component of CDIO (Standard 8). They offer students unfettered access to a set of realistic exercises, during both classroom sessions and independent study. These exercises are meticulously designed to simulate actions that students would undertake on actual machines, fostering a hands-on learning environment. What sets these digital twins apart is their ability to allow students to repeat exercises as many times as needed, replicating real-world scenarios. This affords a unique opportunity for students to refine their skills and gain mastery over complex engineering tasks

Gene transfer of cytoprotective and immunomodulatory molecules for prevention of cardiac allograft rejection

Current treatments of heart transplantation are limited by incomplete effectiveness, significant toxicity, and failure to prevent chronic rejection. Genetic manipulation of the donor heart at the time of removal offers the unique opportunity to produce a therapeutic molecule within the graft itself, while minimizing systemic effects. Cytoprotective approaches including gene transfer of heme oxygenase (HO)-1, endothelial nitric oxide synthase, and antisense oligodeoxynucleotides specific for nuclear factor (NF)-κB or intercellular adhesion molecule (ICAM)-1 reduced ischaemia-reperfusion injury and delayed cardiac allograft rejection in small animals. Exogenous overexpression of immunomodulatory cytokines such as interleukin (IL)-4, IL-10 and transforming growth factor-β, as well as gene transfer of inhibitors of pro-inflammatory cytokines also delayed graft rejection. Gene transfer-based blockade of T-cell costimulatory activation with CTLA4-Ig or CD40-Ig resulted in long-lasting graft survival and donor-specific unresponsiveness, as manifested by acceptance of a second graft from the original donor strain but rejection of third-party grafts. Similar results were obtained with donor major histocompatibility complex class I gene transfer into bone marrow cells. Gene therapy approaches to chronic rejection included gene transfer of HO-1, soluble Fas, tissue plasminogen activator and antisense oligodeoxynucleotides specific for the anti-apoptotic mediator Bcl-x or the E2F transcription factor. Despite major experimental advances, however, gene therapy for heart transplantation has not entered the clinical arena yet. Fundamental questions regarding the most suitable vector, the best gene, and safety issues remain unanswered. Well-controlled studies that compare gene therapy with established treatments in non-human primates are needed before clinical trials can be starte

Helper-dependent adenovirus vectors devoid of all viral genes cause less myocardial inflammation compared with first-generation adenovirus vectors

Abstract. : Background: : First-generation, E1-deleted (ΔE1) adenovirus vectors currently used in cardiovascular gene therapy trials are limited by tissue inflammation, mainly due to immune responses to viral gene products. Recently, helper-dependent (HD; also referred to as "gutless”) adenovirus vectors devoid of all viral coding sequences have been shown to cause low inflammation when injected intravenously or into skeletal muscles. However, HD vectors have not been evaluated in cardiovascular tissues. Methods and results: : HD and ΔE1 vectors containing a cytomegalovirus-driven expression cassette for the green fluorescent protein (GFP) gene were administered intramyocardially to adult rats (n = 54). GFP expression was measured by ELISA at varying time intervals after gene transfer. HD and ΔE1 vectors were equally efficient at transducing the myocardium. Tissue inflammation was assessed by immunostaining for leukocytes and quantitative real-time RT-PCR for cytokine mRNA expression. Monocyte/macrophages, CD4+ and CD8+ lymphocytes infiltrating the myocardium were less abundant with HD than ΔE1 vectors. Transcripts levels for pro-inflammatory cytokines such as IL-1β, tumor necrosis factor-α, and RANTES were decreased with HD vectors. However, both vectors were associated with a decline in GFP expression over time, although low-level expression was occasionally detectable 10 weeks after HD vector administration. The two vectors transduced endothelial cells in rat arteries (n = 11) with comparable efficiencies. Vascular GFP expression was not detectable at 10 weeks. Conclusions: : HD vectors are as efficient as ΔE1 vectors at transducing the myocardium and vascular endothelium, while causing less myocardial inflammation. Thus, HD vectors may be superior to earlier-generation adenovirus vectors for cardiovascular gene therapy application