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Soutenir la politique royale : l’ostension des collections d’antiques par la noblesse d’épée, des guerres d’Italie à la mort d’Henri II
No full textInternational audienc
Se (trans)former auprès de la nature. Une lecture des Conférences sur l'avenir des établissements d'enseignement
No full textInternational audienc
Enarratio in Psalmum LXXI [introduction, traduction et annotation ; notes complémentaires]
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Ultra-sensitive radon assay using an electrostatic chamber in a recirculating system
No full textInternational audienceRare event searches such as neutrinoless double beta decay and Weakly Interacting Massive Particle detection require ultra-low background detectors. Radon contamination is a significant challenge for these experiments, which employ highly sensitive radon assay techniques to identify and select low-emission materials. This work presents the development of ultra-sensitive electrostatic chamber (ESC) instruments designed to measure radon emanation in a recirculating gas loop, for future lower background experiments. Unlike traditional methods that separate emanation and detection steps, this system allows continuous radon transport and detection. This is made possible with a custom-built recirculation pump. A Python-based analysis framework, PyDAn, was developed to process and fit time-dependent radon decay data. Radon emanation rates are given for various materials measured with this instrument. A radon source of known activity provides an absolute calibration, enabling statistically-limited minimal detectable activities of 20 Bq. These devices are powerful tools for screening materials in the development of low-background particle physics experiments
Advanced Composites Manufacturing and Plastics Processing, 2nd Volume
No full textEnvironmental and energy concerns and digitalization are currently having profound effects in reshaping the plastics and composites industry. Manufacturing processes and systems evolve accordingly in order to cost-effectively produce high-performance, high-quality, lightweight, and multifunctional parts with a reduced carbon footprint. All composites manufacturing and polymer processing technologies are concerned with this trend: liquid composite molding (e.g., resin transfer molding and resin infusion/vacuum infusion), automated lay-up (e.g., automated fiber placement and automated tape laying), filament winding, prepreg technology, pultrusion, autoclave, compression molding, film stacking, additive manufacturing/3D printing, injection molding, over-molding/back-molding, extrusion, blow molding, thermoforming, rotational molding, foaming, coating, preforming of textile reinforcement, joining/welding, and mold technologies (i.e., mold making and design).Following the previous Topic (Advanced Composites Manufacturing and Plastics Processing), this new Topic welcomes original research articles, state-of-the-art reviews, and short communications on the latest advances in composites manufacturing and plastics processing. Suggested contributions may address new process developments, modeling/simulation, monitoring/control, and performance or application issues, with either experimental or numerical approaches. All types of polymers (thermoplastics, thermosets, and elastomers) and fibers/fillers (glass, carbon, ceramic, mineral, and vegetal) are eligible topics of focus, whether they come from recycled, bio-based, or fossil feedstocks. Multidisciplinarity is also encouraged to cover emerging topics such as smart manufacturing, artificial intelligence applied to manufacturing, data-driven simulations, and digital twins
Hydrophobization of carboxymethyl cellulose by Passerini reaction: towards films with improved water vapor barrier properties
No full textInternational audienceTo address the need for developing sustainable materials with effective barriers to water vapor, this work explores the potential of self-supported films made of carboxymethyl cellulose (CMC) functionalized by the Passerini three-component reaction. Aliphatic aldehydes and tert-butyl isocyanide were grafted onto CMC backbone to yield dually hydrophobized derivatives. These modified polysaccharides were processed into films by solvent casting and their water vapor transfer properties were examined. Small-angle X-ray scattering (SAXS) experiments revealed a nanoscale organization for Passerini-modified films, attributed to the formation of hydrophobic domains characterized by a nanometric interdomain spacing. Dynamic vapor sorption (DVS) analysis demonstrated a significant reduction in moisture content water for modified films, from ≃ 1.1 g g -1 for unmodified CMC to below 0.5 g g -1 for hydrophobized derivatives at a w = 0.95. Guggenheim-Anderson-deBoer (GAB) and Zimm-Lundberg modeling showed a decrease in sorption site availability from 3 to ≃ 1.5 per glucose unit, while the size of water clusters was significantly increased. The Passerini modification also resulted in a substantial decrease of water vapor permeability (WVP) from 44 000 barrer to 2500 barrer at a w = 0.5. These results unequivocally underpin the benefits of the Passerini functionalization which allows to enhance the water vapor barrier performance. The findings highlight the potential of such a reaction for developing next-generation and bio-based packaging materials with tailored water vapor barrier properties.</div
Non-local aspects of cognition
No full textInternational audienceThis article explores the non-local aspects of cognition in two main directions, respectively contradicting the idea that 1) it exclusively refers to the cognitive subject's intrinsic mental aptitudes and that 2) it is exclusively centred on the subject’s spatial and temporal localisation. Following 4E cognition, the first direction mentions quite reasonable externalist and multiscale aspects of cognition by successively referring to Clark’s and Chalmers’ concept of extended mind, to social cognition, to Hutchins’ concept of distributed cognition and to Laurent’s multiscale enaction model. The second direction the concept of non-local cognition will be explored puts into question the spatio-temporal locality of cognition since it refers to the possibility of extra-sensory perception. The reality of extra-sensory perception is suggested by the non-reductive solutions to the problem of consciousness, and it is supported by very significant experimental results. The millenary interest in extra-sensory perception will be mentioned, with a special focus on Hinduism for its explicit reference in Pantanjali’s Yoga Sutra. Some of the significant experimental tests aimed to show its existence and some hints for building a theoretical modelling of it will then be presented. The reasons why the reality of extra-sensory perception is generally rejected by the scientific community despite numerous significant experimental results, as well as philosophical justifications and theoretical advances, will be discussed. This article pays particular attention to the second sense of ‘non-local’, based on the possibility of extra-sensory perception, insofar as this disturbing but rigorous scientific field of research is almost not at all considered by the current studies in cognitive science
Diet composition and trophic ecology of two Antarctic storm-petrel species
No full textInternational audienceAvailability and quality of food shape the distribution and movements of animal populations. In sympatric species, sharing limited resources, coexistence is typically achieved through niche segregation. However, information on dietary niches is lacking particularly for small and elusive seabirds, which often forage in remote oceanic areas. In this study, we aimed to characterize the trophic ecology of two highly pelagic seabird species, Wilson’s storm-petrel Oceanites oceanicus and Black-bellied storm-petrel Fregetta tropica, breeding sympatrically on King George Island, maritime Antarctica, using a combination of methods. Prey species, assayed via metabarcoding of faecal and regurgitate samples, were dominated by teleost fish, primarily lanternfish (Myctophidae), and zooplanktonic crustaceans, mainly krill (Euphausiidae), but also included other prey with lower frequencies of occurrence, such as salps and amphipods. We used carbon and nitrogen bulk stable isotopes and compound-specific isotope analyses of amino acids of blood samples to derive isotopic niches and trophic positions, showing that Black-bellied storm-petrels prey on a slightly higher trophic position than Wilson’s storm petrels(3.7 and 3.5, respectively). Combining results of stable isotope and molecular diet analysis, indicate a diet richer in fish for Black-bellied storm-petrels and thus a potential niche segregation not in regards of general prey spectrum but proportion of specific prey types (prey composition). Additionally, intraspecific segregation in prey spectrum was observed in Wilson’s storm-petrels concerning their breeding stage (incubation vs. chick-rearing), suggesting selective chick provisioning. Future studies should investigate a potential interspecific spatial segregation in foraging areas
Engineering Synthetic Apomixis in Hybrid Rice
No full textEG, IK, RM, and VS are co-inventors of patent WO2024074888 (PCT/IB2023/000562).International audienceThe transfer of apomixis, a clonal mode of reproduction by seeds, to crops has the potential to revolutionize agriculture by enabling the generation of one-line F1 hybrids that propagate clonally by seeds from one generation to the next. However, despite nearly four decades of intensive research, all the attempts to transfer the identified genetic determinants of apomixis from naturally apomictic wild plants to their crop relatives have failed to produce apomictic crops. Engineering of apomixis, mimicking the key features of a natural form of apomixis known as gametophytic diplosporous apomixis, has recently been achieved in rice and further improvements by the introduction of a single “all-in-one” T-DNA construct into calli derived from F1 hybrid seed embryos resulted in high frequency of clonal seeds. The T-DNA encodes a constitutively expressed Cas9 protein guided by sgRNAs designed to knock-out the functions of three genes essential for regulating crucial steps involved in meiosis, thereby eliminating meiosis and creating the Mitosis instead of Meiosis (MiMe) triple mutant. Additionally, the T-DNA contains another gene expression cassette consisting of a parthenogenetic trigger, the BABY BOOM1 (BBM1) transcription factor driven by an egg cell-specific (ECS) promoter. Inactivation of the three MiMe genes converts meiosis into mitosis—apomeiosis—yielding unrecombined and unreduced male and female spores developing into gametophytes. The BBM1 expression triggers parthenogenetic development of an embryo from the diploid egg cell of the female gametophyte. The endosperm develops sexually by the fusion of a diploid sperm cell and the central cell of the female gametophyte, which contains two diploid polar nuclei, resulting in an initially hexaploid endosperm. To date, the “all-in-one” T-DNA method has proved to be the most efficient for achieving high frequency (95–100% clonal seeds) synthetic apomixis in rice. Since the original publication, we have successfully generated synthetic apomictic events in three additional F1 hybrids. Here, we describe the methods for designing T-DNA constructs, analyzing mutations in first-generation (T0) MiMe mutant plants of F1 hybrids, and ascertaining the apomictic nature of the progenies from confirmed MiMe F1 hybrids, which relies on the egg cell-specific accumulation of BBM1
Reactivity of high-entropy alloy nanoparticles under O 2 studied by in situ transmission electron microscopy
No full textInternational audienceThe gas reactivity of high-entropy nanoalloys (HENAs) is an emerging area of research with significant potential for applications in catalysis, gas sensing, hydrogen storage, and corrosion resistance. Insights into the structure–reactivity relationships that dictate the behavior of HENAs in reactive gas environments are critical for optimizing their performance across these applications. However, understanding the complex structural attributes of HENAs, such as size, shape and structure in response to a gas stimulus, remains challenging because of the limited accessibility to methods capable of probing these attributes under in situ or operando conditions. Here, we performed aberration-corrected environmental gas scanning transmission electron microscopy (STEM) observations to investigate the atomic and chemical structures of quinary CoNiCuPtAu HENAs in response to pure oxygen exposure at atmospheric pressure and elevated temperatures. The nanoparticles were fabricated by pulsed laser deposition with a high degree of control over both size and composition. Atomic-scale STEM imaging combined with energy dispersive X-ray (EDX) spectroscopy at the single particle level revealed a complex structural and chemical evolution pathway for CoNiCuPtAu HENAs under oxygen at atmospheric pressure during progressive heating up to 700 °C. Notably, we have identified substantial mass transfers between nanoparticles accompanied by oxygen-induced demixing of components, nanovoid formation and the stabilization of platelet-like nanostructures crystallizing as a Co–Ni oxide solid solution