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L'enseignement de l'histoire au lycée de Lescar (1993-1996)
No full textNational audienceLes murs du lycée de Lescar sont intimement liés à l'histoire : ils portent, par leur épaisseur, tout le poids d'un passé prestigieux. D'abord couvent au pied de la colline portant la cathédrale de l'ancienne capitale du Béarn, le bâtiment fût ensuite une École normale de la République et, enfin, transformé en lycée où je fus élève -- et fils du proviseur. Ces siècles d'histoire abritaient notre quotidien familial durant toute une jeunesse studieuse, marquée en particulier par les cours d'histoire que j'y ai suivis entre 1993 et 1996 et dont je veux ici témoigner. Il s'agit donc de décrire le patrimoine du lycée par l'entrée de ses curricula et des savoirs qui y étaient dispensés, c'est un patrimoine immatériel, si ce n'est de l'humanité, du moins de la ville
Self-limiting states of polar misfits: frustrated assembly of warped-jigsaw particles
No full text24 pages, 10 figures, 4 appendicesWe study the ground state thermodynamics of a model class of geometrically frustrated assemblies, known as {\it warped-jigsaw} particles. While it is known that frustration in soft matter assemblies has the ability to propagate up to mesoscopic, multi-particle size scales, notably through the selection of self-limiting domain, little is understood about how the symmetry of shape-misfit at the particle scale influences emergent morphologies at the mesoscale. Here we show that polarity in the shape-misfit of warped-jigsaw puzzles manifests at a larger scale in the morphology and thermodynamics of the ground-state assembly of self-limiting domains. We use a combination of continuum theory and discrete particle simulations to show that the polar misfit gives rise to two mesoscopically distinct polar, self-limiting ribbon domains. Thermodynamic selection between the two ribbon morphologies is controlled by a combination of the binding anisotropy along distinct neighbor directions and the orientation of polar shape-misfit. These predictions are valuable as design features for ongoing efforts to program self-limiting assemblies through the synthesis of intentionally frustrated particles, and further suggests a generic classification of frustrated assembly behavior in terms of the relative symmetries of shape-misfit and the underlying long-range inter-particle order it frustrates
Long lasting argon neuroprotection in a non-human primate model of transient endovascular ischemic stroke
No full textInternational audienceIn the past decade, noble gases have emerged as highly promising neuroprotective agents. Previous studies have demonstrated the efficacy of argon neuroprotection in rodent models of cerebral ischemia. The objective of the present pre-clinical study was to confirm the neuroprotective effect of argon in a non-human primate model of endovascular ischemic stroke. Thirteen adult Macaca mulatta were subjected to a focal cerebral ischemia induced by a transient (90 min) middle cerebral artery occlusion (tMCAO). The monkeys were randomly allocated to a control group (n = 8) and an argon group (n = 5). Pre-mixed gas (40–60 oxygen-argon) was applied 30 min after the onset of tMCAO to 30 min after reperfusion. Infarct volumes were measured from the MRI scans conducted 1 hour and 1 month after the reperfusion. A clinical neurological assessment was performed 24 hours and 1 month after tMCAO. Our results show that Argon dramatically reduced ischemic core volume after ischemia compared to the control group with a long-lasting improvement of post-stroke infarct volume at 1 month. In addition, the neurological scale suggests a better prognosis in argon-treated animals without reaching the significance threshold. These pre-clinical results in gyrencephalic non-human primates support the potential use of this therapeutic approach for future clinical studies
A Staggered Lattice Boltzmann Method for the Radiative Transfer Equation
No full textInternational audienceThis paper introduces a method for the numerical approximation of solutions of the monokinetic Radiative Transfer Equation, adapting some of the features of the Lattice Boltzmann Method. The main difference between the Radiative Transfer Equation and the Boltzmann Equation used in the classical Lattice Boltzmann Method framework lies in the constrained norm of the velocity field appearing in the advection operator. This small difference leads to off-grid propagation if one uses a regular lattice, as classically done for efficiency reasons. To recover on-grid propagation, this paper introduces a specific time discretization along each propagation directions and an original traversal algorithm to allow for scattering between different directions at common times. The algorithm involves only linear time interpolations so as to preserve the local nature of the Lattice Boltzmann Method. The direction quadrature follows the principles of the Discrete Ordinate Method. The relevance of the approach is illustrated on different two-dimensional problems and the results are compared to previously published numerical test-cases.</div
20 years of research on giant viruses
No full textInternational audienceSome twenty years ago, the discovery of the first giant virus, Acanthamoeba polyphaga mimivirus (now mimivirus bradfordmassiliense species), paved the way for the discovery of more than 10 new families of protist-infecting DNA viruses with unexpected diversity in virion shape and size, gene content, genome topology and mode of replication. Following their brief description, we examine how the historical concepts of virology have held up in the light of this new knowledge. Although the initial emphasis was on the gigantism of the newly described viruses infecting amoebae, the subsequent discovery of viruses with intermediate virion and genome sizes gradually re-established a continuum between the smallest and largest viruses within the phylum Nucleocytoviricota
DOUBLE CIRCULANT CODES FROM CUBIC CYCLOTOMY
No full textInternational audienceWe introduce a parametrized family of binary double circulant codes, based on cubic cyclotomy. We determine the parameters for which the codes are self-dual and those for which they are LCD (Linear Complementary Dual). As a bonus, they turn out to be formally self-dual in the latter case. The main theoretical tools are the properties of cyclotomic numbers. Examples in modest length show quasi-optimal formally self-dual codes.</div
Grain orientation and temperature dependences of bubbles at tungsten surfaces upon helium plasma exposure
No full textInternational audienceThe impact of grain orientation and surface temperature on helium bubble growth at tungsten surfaces exposed to low-pressure helium plasmas was investigated by analyzing the nanoholes formed at the surface. Polycrystalline tungsten samples were exposed to a 2 Pa RF plasma at 400 W and 79 eV positive ion bombardment energy. Through detailed SEM imaging before and after plasma exposure and a developed image analysis protocol, we assessed quantitatively the size and density of helium bubbles that have burst on the surface upon plasma exposure. The results demonstrate a clear temperature dependence, with surface bubble density and size increasing at higher temperatures, and a dependence on grain orientation, with the (111) orientation giving slightly larger and denser surfaces of burst bubbles
STING‐Activating Polymers Boost Lymphatic Delivery of mRNA Vaccine to Potentiate Cancer Immunotherapy
No full textInternational audienceThe unprecedented success of mRNA vaccines against COVID‐19 has inspired scientists to develop mRNA vaccines for cancer immunotherapy. However, using nucleoside modified mRNA as vaccine, though evading innate immune toxicity, diminishes its therapeutic efficacy for cancers. Here, we report a polyvalent stimulator of interferon genes (STING) activating polymer (termed as PD) to bolster the immunogenicity of mRNA vaccine. PD is made of tertiary amine units and conjugated with a biodegradable alkyl chain. Co‐formulation of PDs bearing different number of tertiary amines with lipid materials and mRNA resulted in the lipid‐like nanoparticles (PD LNPs) which effectively promoted lymphatic delivery and elicited robust immune activation via the STING signaling pathway. Notably, PD with eighteen tertiary amines (PD18) is predominant in balancing immune activity and tolerability. Subcutaneous administration of PD18 LNPs containing ovalbumin (OVA) mRNA enhanced the frequency of antigen specific CD8 + T cell with immune memory, leading to potent anticancer efficacy that surpassed 2′3’‐cGAMP in both prophylactic and therapeutic cancer models. Additionally, PD18 LNP‐based mRNA vaccine showed conferred resistance to cancer challenge for up to 60 days. Overall, this study offers a new perspective of using STING‐ activating polymer for imparting synergistic activity in mRNA vaccine‐based cancer immunotherapy
Communications between Western Pilgrims and People in the Holy Land
No full textInternational audiencePilgrimages to the Holy Land brought Western pilgrims into contact with Eastern populations: Muslims, Jews and Christians. In the fifteenth century, some pilgrims showed a certain interest and curiosity about the local populations and reported situations when communication and conversation took place. This article looks at the circumstances of such communication, and in particular the question of language and translation, as well as the content of the exchanges
Transgenic corn syrup enhances in vitro yeast ethanol production: Hidden cause of the US MASH epidemic?: Transgenic corn syrup enhances in vitro yeast ethanol production
No full textThe incidence of metabolic dysfunction-associated liver steatohepatitis (MASH) has risen over the last decade, making it a major health problem and the second leading cause of liver disease in the US. Recent studies suggest that MASH may be linked to the endogenous production of alcohol in the digestive tract after sugar ingestion, with bacteria such as Klebsiella and Lactobacillus playing a key role in this fermentation. More recently, the role of the gut mycobiota has also been suggested. In particular, MASH has been recently associated with the presence of yeast strains that produce high concentrations of alcohol in the gut microbiota. As the source of sugar varies by region -transgenic maize in the USA, sugar cane in Africa and beet in France -we hypothesised that consumption of sweetened beverages, in combination with the gut mycobiota, may be a contributing factor to MASH.Analysis of American and French Coca-Cola and World-Cola from Mali revealed significant differences in carbohydrate composition, with the presence of complex oligosaccharides in American Coca-Cola. A significantly higher ethanol production was observed when a Candida albicans yeast strain was cultured in American Coca-Cola compared to the other two colas. The results suggest that consumption of transgenic maize sweeteners may increase the risk of autobrowery syndrome and underline the need for epidemiological studies to assess the association of these carbohydrates with the MASH epidemic in the US.</div