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Detection of rare plasmid hosts using a targeted hi-C approach
No full textInternational audienceAbstract Despite the significant role plasmids play in microbial evolution, there is limited knowledge of their ecology, evolution, and transfer in microbial communities. This is partly due to the limitations of current methods in associating a plasmid with its host in microbiomes. To address this knowledge gap, we developed and implemented a novel approach to identify rare plasmid hosts by combining Hi-C, a proximity ligation method, with enrichment for plasmid-specific DNA. We hereafter refer to this approach as Hi-C+. We applied Hi-C and Hi-C+ to soil microbial communities in which we mimicked increasingly rare transfer of an antimicrobial resistance plasmid from a donor to a recipient. This was achieved by inoculating agricultural soil with mixtures of known plasmid-containing and plasmid-free cells at different proportions. We demonstrated that Hi-C can link a plasmid to its host in soil when the relative abundance of that plasmid-host pair is as low as 0.001%. Hi-C+ further improved the detection limit of Hi-C 100-fold and allowed the identification of plasmid hosts at the genus level. As a culture-independent approach, Hi-C+ will significantly improve our understanding of the range and frequency of spread of antibiotic resistance and other genes that are introduced into soil and other microbiomes
Scientific response to the 2021–2022 seismic swarm in the Monts Dore volcanic province (France): dynamic insights from temporal surveys (2/2)
No full textInternational audienceDuring years 2021-2022, an unusual seismic swarm was recorded at crustal level beneath the Monts Dore volcanic province (France). Complementary field and remote measurements were performed. Together with the time series recorded on the seismological and GNSS national networks, these measurements were fundamental for monitoring the evolution of the seismic swarm and deciphering its origin. Although a potential vertical migration of the seismic events is suggested, the complementary measurements presumably discard the hypothesis of magma intrusion at shallow crustal level. The ascent of a CO2-rich fluid originating from the mantle might instead have reacted with the hydrothermal system beneath the Monts-Dore since at least the summer 2021 leading to the reactivation of pre-existing tectonic structures with known associated seismicity. Feedback on the management of the 2021-2022 seismic swarm prompts for several recommendations that should be considered in future to better face and address at the national level the issues raised at long-dormant volcanic provinces in mainland France
L'exposition répétée de la tête à un signal 5G-3,5 GHz ne modifie pas le comportement mais modifie l'expression génétique intracorticale chez les souris mâles adultes
No full textInternational audienceThe fifth generation (5G) of mobile communications promotes human exposure to electromagnetic fields exploiting the 3.5 GHz frequency band. We analyzed behaviors, cognitive functions, and gene expression in mice submitted to asymmetrical head exposure to a 5G-modulated 3.5 GHz signal. The exposures were applied for 1 h daily, 5 days per week over a six-week period, at a specific absorption rate (SAR) averaging 0.19 W/kg over the brain. Locomotor activities in an open field, object location, and object recognition memories were assessed repeatedly after four weeks of exposure and did not reveal any significant effect on the locomotion/exploration, anxiety level, or memory processes. mRNA profiling was performed at the end of the exposure period in two symmetrical areas of the right and left cerebral cortex, in which the SAR values were 0.43 and 0.14 W/kg, respectively. We found significant changes in the expression of less than 1% of the expressed genes, with over-representations of genes related to glutamatergic synapses. The right cortical area differed from the left one by an over-representation of responsive genes encoded by the mitochondrial genome. Our data show that repeated head exposures to a 5G-3.5 GHz signal can trigger mild transcriptome alterations without changes in memory capacities or emotional state
Données thermodynamiques molaires de l’oxyde de zinc gazeux
No full textInternational audienceThe calculation of the zinc oxide molar thermodynamic properties is proposed and discussed. This molecule is of paramount importance in controlling deposit properties such as nanostructure and surface crystalline orientation. We review all the necessary formulas as well as the influence of quantum numbers required for calculating partition functions. The results are provided in the form of a table with temperatures ranging from 100 K to 20,000 K.Le calcul des propriétés thermodynamiques molaires de l’oxyde de zinc est proposé et discuté. Cette molécule revêt une importance capitale dans le contrôle des propriétés des dépôts comme la nanostructure et l’orientation cristalline des surfaces. Nous rappelons l’ensemble des formules nécessaires ainsi que l’influence des nombres quantiques nécessaires pour le calcul des fonctions de partition. Les résultats sont fournis sous forme d’une table dont les températures varient de 100 K à 20000 K
Partial transvenous embolization as an intermediate strategy for large brain arteriovenous malformations: A technical note
No full textInternational audienceBackground Endovascular transvenous embolization (TVE) was developed as a curative technique for brain arteriovenous malformations (bAVMs) with small nidi and a single draining vein. We describe a partial transvenous embolization technique (pTVE) as an intermediate embolization session to decrease hemorrhagic complications of larger nidi with multiple venous outlets. Method We reviewed our single-center database of bAVMs treated endovascularly between January 2023 and March 2024. Six consecutive patients underwent 10 sessions of pTVE for ruptured AVMs. Results The median age of patients was 24.5 years. The median nidus size was 5 cm (range 4–6 cm). Three patients had grade III lesions according to the Spetzler-Martin classification, two were grade IV, and one was grade V. Four patients had draining veins with multiple efferent veins with each collecting vein, one patient had multiple efferent veins with one collecting vein, and one patient had one efferent vein with a long bifurcation. pTVE achieved partial occlusion in all cases without any hemorrhagic complications. One patient had the AVM totally occluded with two sessions of pTVE. Decision-making was facilitated by creating subcategories of venous angioarchitecture and detailing the technical particularities in the corresponding category. Conclusion We described a novel treatment technique of transvenous embolization as an adjunct strategy for large bAVMs
Transitions épidémiologiques : agir sur les facteurs de risques communs aux maladies non-transmissibles dans le contexte multiculturel de l'Indianocéanie
No full textInternational audienceLa transition épidémiologique désigne le passage d’un fardeau de morbidité et de mortalité dominé par les maladies infectieuses à un fardeau principalement constitué de maladies non transmissibles (MNT) (Omran AR, 2005). Ces maladies, notamment l’infarctus du myocarde, les accidents vasculaires cérébraux, les cancers, le diabète et les affections respiratoires chroniques, sont responsables de près de 74 % des décès dans le monde, dont 86 % surviennent prématurément dans les pays à revenu faible ou intermédiaire (PRFI). L’augmentation des MNT est principalement due à six facteurs de risque majeurs : le tabagisme, l’inactivité physique, l’usage nocif de l’alcool, une mauvaise alimentation, la pollution atmosphérique et le manque de sommeil (OMS, 2023). Dans les territoires insulaires océaniens, les MNT constituent la première cause de mortalité, représentant 60 % à 75 % des décès, touchant principalement les personnes de moins de 60 ans (United Nation, 2019).Face à cette situation, les stratégies de prévention en santé publique constituent un levier essentiel pour réduire ces facteurs de risque des MNT et améliorer le bien-être des populations (OMS, 2023). Toutefois, l’efficacité des politiques de prévention varie considérablement selon les contextes politiques, économiques et sociaux propres à chaque État de l’Indianocéanie, ce qui rend la lutte contre les MNT hétérogène dans la région.L’objectif général de cette thèse sera d’évaluer l’adéquation des différentes stratégies de prévention des facteurs de risque des maladies non transmissibles à la situation épidémiologique de chaque territoire insulaire de l’Indianocéanie
Du sens à l’action. Une rencontre entre sémiotique et pragmatique autour du concept de ‘force’
No full textDecoupled charge and heat transport in Fe2VAl composite thermoelectrics with topological-insulating grain boundary networks
No full textInternational audienceAbstract Decoupling charge and heat transport is essential for optimizing thermoelectric materials. Strategies to inhibit lattice-driven heat transport, however, also compromise carrier mobility, limiting the performance of most thermoelectrics, including Fe 2 VAl Heusler compounds. Here, we demonstrate an innovative approach, which bypasses this tradeoff: via liquid-phase sintering, we incorporate the archetypal topological insulator Bi 1− x Sb x between Fe 2 V 0.95 Ta 0.1 Al 0.95 grains. Structural investigations alongside extensive thermoelectric and magneto-transport measurements reveal distinct modifications in the microstructure, a reduced lattice thermal conductivity and a simultaneously enhanced carrier mobility arising from topologically protected charge transport along the grain boundaries. This yields a huge performance boost, resulting in one of the highest figure of merits among both half- and full-Heusler compounds, z ≈ 1.6 × 10 −3 K −1 ( z T ≈ 0.5) at 295 K. Our findings highlight the potential of topological-insulating secondary phases to decouple charge and heat transport and call for more advanced theoretical studies of multiphase composites
An alternating direction method of multipliers approach for the reconfiguration of radial electrical distribution systems
No full textInternational audienceThe electrical network reconfiguration problem aims to minimize losses in a distribution system by adjusting switches while ensuring the radiality (tree structure) of the network. Although this problem can be formulated as a mixed integer nonlinear program, solving the resulting optimization problem requires significant time and resources. A carefully selected initial solution, which can be identified by appropriate heuristics, reduces the search space, accelerates convergence, and ensures feasibility. This paper introduces two heuristic algorithms based on the Alternating Direction Method of Multipliers (ADMM) to address this problem. These heuristics break down the problem into smaller, more manageable subproblems that can be solved efficiently. Two algorithms are developed: one relies on natural variable substitution, and the other on a previously used relaxation technique. The challenge encountered in previous studies of incorporating radial constraints with ADMM is addressed by redefining the combinatorial subproblem in the projection step of ADMM as a minimum weight rooted arborescence problem, whose solutions are guaranteed to be radial. Convex optimization techniques can then handle the remaining subproblems. The performance of both heuristics is evaluated through numerical experiments on the 33-bus and 70-bus systems, as well as on a real-world electrical network
Mythe et création : les grandes productions lyriques au Palais Garnier
No full textInternational audienc