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Excitation of Molecular Hydrogen in Seyferts : NGC 5506 and NGC 3081
No full textInternational audienceWe utilize James Webb Space Telescope (JWST) Mid Infrared Instrument (MIRI) integral field unit observations to investigate the behavior and excitation of H 2 in the nearby Seyfert galaxies NGC 3081 and NGC 5506, both part of the Galactic Activity, Torus, and Outflow Survey (or GATOS). We compare population levels of the S(1) to S(8) rotational H 2 emission lines visible to JWST/MIRI spectroscopy to models assuming local thermodynamic equilibrium (LTE), in order to estimate the column density and thermal scaling of the molecular gas. For the nuclear regions, we incorporate Very Large Telescope Spectrograph for INtegral Field Observations in the Near Infrared (or VLT/SINFONI) K-band observations to estimate population levels for available rovibrational H 2 emission lines, and compare the resultant population curves to non-LTE radiative transfer models and shock modeling. We report a differing set of prominent active galactic nuclei (AGN)-driven excitation mechanisms between the two galaxies. For NGC 3081, we find that a non-LTE radiative transfer environment is adequate to explain observations of the nuclear region, indicating that the primary mode in which the AGN transfers excitation energy is likely irradiation. We estimate the extent of AGN photoionization along the ionization bicone to be ≈330 pc. In contrast, for NGC 5506, we find a shock scenario to be a more plausible excitation mechanism, a conclusion bolstered by an observed spatial correlation between higher-energy rotationa
Du Fondo Barbatelli à la Porte du Vésuve : une fenêtre d’étude dans le faubourg septentrional de Pompéi. Campagne d’étude 2024
No full textInternational audienc
Floquet Theory of lattice electrons coupled to an off-resonant cavity
No full textWe use Floquet theory and the High-Frequency expansion to derive an effective Hamiltonianfor electrons coupled to an off resonant cavity mode, either in its vacuum or driven by classicallight. For vacuum fields, we show that long-range hopping and cavity-mediated interactions ariseas a direct consequence of quantum fluctuations. As an application, this method is applied tothe Su-Schrieffer-Heeger (SSH) model. At high light-matter coupling, our results reveal significantdeviations from mean-field predictions, with our framework capturing light-matter entanglementthrough the Floquet micromotion. Furthermore, the cavity-mediated interactions appearing at firstorder are shown to be crucial to the description of the system at sufficiently strong light-mattercoupling for a fixed cavity frequency. Finally, a drive resonant with the cavity is added with theSSH chain displaying dynamical behavior dependent on the cavity parameters
Quantum Electrodynamics of graphene Landau levels in a deep sub-wavelength hyperbolic phonon polariton cavity
No full textThe confinement of electromagnetic radiation within extremely small volumes offers an effective means to significantly enhance light-matter interactions, to the extent that zero-point quantum vacuum fluctuations can influence and control the properties of materials. Here, we develop a theoretical framework for the quantum electrodynamics of graphene Landau levels embedded in a deep sub-wavelength hyperbolic cavity, where light is confined into ultrasmall mode volumes. By studying the spectrum, we discuss the emergence of polaritons, and disentangle the contributions of resonant quantum vacuum effects from those of purely electrostatic interactions. Finally, we study the hybridization between magnetoplasmons and the cavity modes. Contents I. Introduction 1 II. Summary of main results 3 A. Theory of the Green's function of HPP cavities 3 B. Theory of Landau levels in Graphene and their coupling to a sub-wavelength cavity 5 C. The polaritonic spectrum and the vacuum Rabi frequency 6 D. Relation to prior works 8 III. Details on "Theory of the Green's function of HPP cavities" 9 A. A quantization scheme for sub-wavelength cavities 11 IV. Details on "Theory of Landau levels in Graphene and their coupling to a sub-wavelength cavity" 14 V. Details on "The polaritonic spectrum and the vacuum Rabi frequency" 15 A. Diagonalizing the Hopfield Hamiltonian 15 B. The vacuum Rabi frequencies 17 C. The depolarization shift 18 D. Two-transition model 19 VI. Conclusions 20 A. Acknowledgments 21 A. The dielectric tensor in hBN 21 B. The density-density response function for graphene in a magnetic field 21</div
The evolution of antibiotic resistance in Europe, 1998–2019
No full textInternational audienceThe evolutionary dynamics of antibiotic resistance are not well understood, particularly the long-term trajectories of resistance frequencies and their dependence on antibiotic consumption. Here, we systematically analyse resistance trajectories for 887 bug-drug-country combinations in Europe across 1998–2019, for eight bacterial species with a considerable resistance-associated public health burden. Our analyses support a model in which, after an initial increase, resistance frequencies reach a stable intermediate equilibrium. The plurality (37%) of analysed trajectories were best described as ‘stable’ (neither increasing nor decreasing). 21% of trajectories were best described as ‘stabilising’ – i.e. showing a transition from increasing frequency to a stable plateau; 21% as decreasing and 20% as increasing. The antibiotic consumption in a country predicts both the equilibrium frequency of the corresponding resistance and the speed at which this equilibrium is reached. Moreover, we find weak evidence that temporal fluctuations in resistance frequency are driven by temporal fluctuations in hospital antibiotic consumption. A large fraction of the variability in the speed of increase and the equilibrium level of resistance remains unexplained by antibiotic use, suggesting other factors may also drive resistance dynamics. Overall, our results indicate that ever increasing antibiotic resistance frequencies are not inevitable
Inborn errors of immunity: Manifestation, treatment, and outcome—an ESID registry 1994–2024 report on 30,628 patients
No full textInternational audienceThe European Society for Immunodeficiencies patient registry (ESID-R), established in 1994, is one of the world’s largest databases on inborn errors of immunity (IEI). IEI are genetic disorders predisposing patients to infections, autoimmunity, inflammation, allergies, and malignancies. Treatments include antimicrobial therapy, immunoglobulin replacement, immune modulation, stem cell transplantation, and gene therapy. Data from 194 centers in 33 countries capture clinical manifestations and treatments from birth onward, with annually expected updates. This report reviews the ESID-R’s structure, data content, and impact. The registry includes 30,628 patient datasets (aged 0–97.9 years; median follow-up: 7.2 years; total 825,568.2 patient-years), with 13,550 cases in 15 sub-studies. It has produced 84 peer-reviewed publications (mean citation rate: 95). Findings include real-world observations of IEI diagnoses, genetic causes, clinical manifestations, treatments, and survival trends. The ESID-R fosters global collaboration, advancing IEI research and patient care. This report highlights the key role of the multinational ESID-R, led by an independent medical society, in evidence-based discovery
Unfitted finite element modelling of surface-bulk viscous flows in animal cells
No full textThis work presents a novel unfitted finite element framework to simulate coupled surface-bulk problems in time-dependent domains, focusing on fluid-fluid interactions in animal cells between the actomyosin cortex and the cytoplasm. The cortex, a thin layer beneath the plasma membrane, provides structural integrity and drives shape changes by generating surface contractile forces akin to tension. Cortical contractions generate Marangoni-like surface flows and induce intracellular cytoplasmic flows that are essential for processes such as cell division, migration, and polarization, particularly in large animal cells. Despite its importance, the spatiotemporal regulation of cortex-cytoplasm interactions remains poorly understood and computational modelling can be very challenging because surface-bulk dynamics often lead to large cell deformations. To address these challenges, we propose a sharp-interface framework that uniquely combines the trace finite element method for surface flows with the aggregated finite element method for bulk flows. This approach enables accurate and stable simulations on fixed Cartesian grids without remeshing. The model also incorporates mechanochemical feedback through the surface transport of a molecular regulator of active tension. We solve the resulting mixed-dimensional system on a fixed Cartesian grid using a level-set-based method to track the evolving surface. Numerical experiments validate the accuracy and stability of the method, capturing phenomena such as self-organised pattern formation, curvature-driven relaxation, and cell cleavage. This novel framework offers a powerful and extendable tool for investigating increasingly complex morphogenetic processes in animal cells
STRATA : Ethnographies indociles de mondes troublés
No full textInternational audienceSTRATA is a collective book that rethinks how we narrate, inhabit, and experience ethnographic encounters through visual and sensory editorial experimentation. Created by anthropologist-artists, it weaves together images, texts, and sounds from six research projects conducted in France, Portugal, Romania, and Congo. The book explores human and non-human relationships, colonial memory, thermoception, temporality, and sensory experience, allowing narrative form to serve as a mode of knowledge.STRATA est une œuvre collective qui repense la manière de raconter, de vivre et d'expérimenter l’enquête ethnographique. Réalisé par un collectif d’anthropologues-artistes, le livre mêle image, texte et film pour explorer les formes sensibles de la recherche en anthropologie. À travers six enquêtes ethnographiques menées en France, au Portugal, en Roumanie et au Congo, STRATA interroge les relations entre humains et non-humains, la mémoire coloniale, le climat, le temps et le vécu du monde
Majorana bound states from cavity embedding in an interacting two-site Kitaev chain
No full textInternational audiencePoor man's Majorana Bound States (MBS) arise in minimal Kitaev chains when the parameters are fine-tuned to a sweet spot. We consider an interacting two-site Kitaev chain coupled to a singlemode cavity and show that the sweet spot condition can be controlled with the cavity frequency and the hopping between sites. Furthermore, we demonstrate that photon-mediated effective interactions can be used to screen intrinsic interactions, improving the original quality of the MBS. We describe experimental signatures in the cavity transmission to detect their presence and quality. Our work proposes a new way to tune poor man's MBS in a quantum dot array coupled to a cavity
From Trial to Archive: The Institutional Transformation of Chinese Astronomy in the Middle Ages
No full textInternational audienceUnder the Han (206 B.C.–A.D. 220), Chinese astronomers referenced “Astronomical Bureau records” in research and evaluation. However, the process of imperial “calendar reform” was open to outside submissions, and it was often decided through deliberation and multi-year competitive live trials run by the Observatory, animated by a spirit of transparency, neutrality, and sportsmanship. By the mid-Tang (618–907), new works were almost exclusively written by commission, polymathic outsiders had given way to hereditary specialists, and the Astronomical Bureau had been moved from the Ministry of Rites to the Palace Library. Both administratively and sociologically, astronomy had transitioned from something of a sport to a “science in the archive” (Daston; Guo Jinsong; Yang Qiao). This talk will explore how this transition occurred in the Period of Disunion (220–589) and discuss the use of “Astronomical Bureau records” both in research and in setting out the arguments for the adoption of one’s procedure text