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: Déchets, énergie, CO2 : enquête sur le bouclage des flux résiduels
No full textInternational audienceLes systèmes urbains contemporains génèrent de manière excessive différentes formes de résidus que l’on cherche à valoriser dans une perspective d’économie circulaire. L’enquête porte sur trois « flux résiduels » – les déchets, l’énergie fatale et le CO2 – en s’attachant à comprendre les multiples niveaux de gouvernance et de cadrage dont ils relèvent et les interdépendances qui les lient. A l’examen des normes, instruments et politiques qui gouvernent ces flux en Europe et en France s’ajoute une analyse territoriale dans quatre métropoles où sont menés des projets et des politiques qui tendent à leur bouclage. Tout en apportant un éclairage sur les évolutions et contradictions de l’action publique environnementale contemporaine, l’ouvrage souligne les limites d’une économie circulaire porteuse de promesses mais aussi de profonds dilemmes
Author Correction: Droplet surface spontaneous oxidation as a dominant formation pathway of organosulfates in the marine atmosphere
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Vascular dysfunctions during radiation retinopathy
No full textInternational audienceOptic tissue toxicity remains a major limitation of radiation therapy for ocular, brain, skull base, and head and neck tumors. Among the most frequent complications, radiation retinopathy (RR) occurs in 6% of patients treated for extraocular tumors and in more than 40% of those with ocular tumors. After an initial asymptomatic stage characterized by vascular remodeling and chronic retinal ischemia, RR may progress to irreversible vision loss and significantly impaired quality of life. Advances in non-invasive, high-resolution imaging have improved our understanding of the molecular and cellular mechanisms underlying RR in both preclinical and clinical models. In particular, multimodal imaging-and especially optical coherence tomography angiography (OCTA)-has enabled earlier detection of RR in humans. Animal studies have highlighted vascular obstruction and rarefaction, together with early neurovascular dysfunction, as central features of the clinical phase. Beyond preventive measures such as dose constraints, biological and imaging biomarkers may help guide targeted interventions. In this review, we summarize current evidence on the sequential endothelial and neuronal alterations that drive RR and discuss molecular and cellular pathways that could inform the development of potential therapeutic strategies
All-sky search for continuous gravitational-wave signals from unknown neutron stars in binary systems in the first part of the fourth LIGO-Virgo-KAGRA observing run
No full textInternational audienceWe present the results of a blind all-sky search for continuous gravitational-wave signals from neutron stars in binary systems using data from the first part of the fourth observing run (O4a) using LIGO detectors data. Rapidly rotating, non-axisymmetric neutron stars are expected to emit continuous gravitational waves, whose detection would significantly improve our understanding of the galactic neutron star population and matter under extreme conditions, while also providing valuable tests of general relativity. Neutron stars in binary systems likely constitute a substantial fraction of the unobserved galactic population and, due to potential mass accretion, may emit stronger gravitational-wave signals than their isolated counterparts. This search targets signals from neutron stars with frequencies in the 100-350 Hz range, with orbital periods between 7 and 15 days and projected semi-major axes between 5 and 15 light-seconds. The analysis employs the GPU-accelerated fasttracks pipeline. No credible astrophysical signals were identified, and, in the absence of a detection, we report search sensitivity estimates on the population of neutron stars in binary systems in the Milky Way
Directional Search for Persistent Gravitational Waves: Results from the First Part of LIGO-Virgo-KAGRA's Fourth Observing Run
No full textInternational audienceThe angular distribution of gravitational-wave power from persistent sources may exhibit anisotropies arising from the large-scale structure of the Universe. This motivates directional searches for astrophysical and cosmological gravitational-wave backgrounds, as well as continuous-wave emitters. We present results of such a search using data from the first observing run through the first portion of the fourth observing run of the LIGO-Virgo-KAGRA Collaborations. We apply gravitational-wave radiometer techniques to generate skymaps and search for both narrowband and broadband persistent gravitational-wave sources. Additionally, we use spherical harmonic decomposition to probe spatially extended sources. No evidence of persistent gravitational-wave signals is found, and we set the most stringent constraints to date on such emissions. For narrowband point sources, our sensitivity estimate to effective strain amplitude lies in the range across all sky and frequency range Hz. For targeted sources -- Scorpius X-1, SN 1987A, the Galactic Center, Terzan 5, and NGC 6397 -- we constrain the strain amplitude with best limits ranging from to . For persistent broadband sources, we constrain the gravitational-wave flux F_{α, \hat{n}}^{95\%, \mathrm{UL}}(25\, \mathrm{Hz}) < (0.008 - 5.5) \times 10^{-8}\, \mathrm{erg\, cm^{-2}\, s^{-1}\, Hz^{-1}}, depending on the sky direction and spectral index . Finally, for extended sources, we place upper limits on the strain angular power spectrum C_\ell^{1/2} < (0.63 - 17) \times 10^{-10} \,\mathrm{sr}^{-1}
FANTASTIC CLINOFORMS AND WHERE TO FIND THEM? A DETAILED LOOK AT FLUVIAL TO DELTAIC DEPOSITS IN GALE'S LAYERED
No full textInternational audienceCuriosity continues to explore the layered sulfate unit (LSu) of Gale crater as it ascends Mount Sharp. In mid-2025, the rover arrived in the orbitally-defined “boxwork” unit (Fig. 1). There, diagenetically-altered, fine-grained textures have been identified hinting at a probable lacustrine setting [1-2].By contrast, the walls of this valley, and particularly that of the Mishe Mokwa, Cordillera, and western Texoli buttes (Fig. 1), display a wealth of multi-scale sedimentary structures. Some of them indicate that complex wet-aeolian alternations occurred at the time of the deposition [3] as a continuation of the previously studied Mirador fm. (e.g., [4-5]). Yet, these outcrops have also revealed unprecedented clinoform geometries.Using image data acquired with ChemCam’s RMI, we detail three types of clinoform strata within the buttes surrounding this area (Fig. 1). These clinoforms differ in size and process from those recognized earlier in the mission at e.g., Kimberley [6]. Among them, we notably propose the first in-situ observation of deltaic geometries by Curiosity
Programming the Optoelectronic Properties of Atomically Precise Gold Nanoclusters Using the Conformational Landscape of Intrinsically Disordered Proteins
No full textInternational audienceThe rational design of hybrid nanomaterials with precisely controlled properties remains a central challenge in materials science. While atomically precise gold nanoclusters (Au‐NCs) offer molecule‐like control over a metallic core, tuning their optoelectronic behavior via surface engineering is often empirically driven. Here, we establish a design principle by demonstrating that the conformational landscape of intrinsically disordered proteins (IDP) can be used as a programmable scaffold to rationally modulate the photophysical properties of a covalently bound Au‐NC. We synthesized a series of bioconjugates between Au 25 nanoclusters and bioengineered IDPs containing a variable number of cysteine anchoring points. A combination of mass spectrometry, small‐angle X‐ray scattering, and modeling on the conjugates indicates that increasing the number of covalent anchors systematically restricts the conformational ensemble, inducing a progressively more compact protein shell around nanoclusters. This structural rigidification at the interface directly translates into a 15‐fold enhancement of the Au‐NC near‐infrared photoluminescence and a six‐fold increase in its average lifetime. Our findings demonstrate that the conformational plasticity of IDPs and the capacity to engineer them can be harnessed as a molecular tuning knob, moving to a new regime of programmable soft‐matter control over the properties of quantum‐confined nanomaterials for tailored biotechnological applications
À qui appartient le 4 juillet ? L’indépendance américaine et sa mémoire
No full textPrésentation de l'éditeur : "Le 250e anniversaire de l’Indépendance des États-Unis est l’occasion d’une bataille culturelle acharnée opposant deux visions de la nation. La première, très conservatrice, promue par l’administration Trump, chante la gloire ancienne et exclusive des héros révolutionnaires. La seconde, nourrie des savoirs de l’histoire sociale et continentale, reconnaît à tous le droit à la liberté et à l’égalité inscrit dans la Déclaration d’indépendance adoptée le 4 juillet 1776. Cet ouvrage analyse ce texte fondateur de la République américaine et sa mémoire contestée pour mettre en perspective la crise politique qui divise aujourd’hui le peuple américain
Interim vaccine effectiveness against influenza virus among outpatients, France, October 2025 to January 2026
No full textInternational audienceIn Europe, the 2025/26 seasonal influenza epidemic started in October 2025. Co-circulation of A(H3N2) and A(H1N1)pdm09 was observed in several countries including France. We estimated early vaccine effectiveness (VE) against influenza virus in French outpatients (5,451 positives/18,816 negatives). A significant VE across all age groups was measured: 28% (95% CI: 17–37) for those aged ≥ 65 years, 45% (95% CI: 36–53) for 18–64-year-olds and 57% (95% CIs: 29–74) for 0–17-year-olds. Reinforcing vaccination uptake is warranted
Jet launching from the Kerr black hole magnetosphere: An electrogeodesic approach
No full textInternational audienceThe launch of relativistic jets of plasma on astrophysical to cosmological scales are observed in a variety of astrophysical sources, from active galactic nuclei to X-rays binaries. While these jets can be reproduced by the general relativistic magneto-hydrodynamic (GRMHD) and particle-in-cells (GRPIC) simulations of the dynamical Kerr magnetosphere, the development of analytic models to describe the physics of the jets has remained limited. A key challenge is to analytically describe the individual trajectories of accelerated charged particles which ultimately build up the jet and emit radiation. In this work, we provide a first simple but fully analytical model of jet launching from the Kerr magnetosphere based on the motion of charged particles. To that end, we use the integrability of electrogeodesic motion in the Kerr monopole magnetosphere to study the ejection of charged particles near the poles. This enables us to derive (i) a criterion for the rotation axis to constitute a stable latitunal equilibrium position, thereby representing an idealized jet, (ii) the expression for the magnetic frame-dragging effect, and (iii) the condition for an asymptotic observer to measure blueshifted particles emanating from the black hole surroundings. Our study reveals that particles can be accelerated only in a specific region whose maximal radius depends on the spin and magnetization of the black hole. Alongside these results, we provide a detailed review of the construction of test magnetospheres from (explicit and hidden) symmetries of the Kerr geometry and the condition for the separability of the electrogeodesic motion in a test magnetosphere, which serves as a basis for the model we study in this work