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Muscle Retracting Sign in Colorectal Macronodular Lesions: Prevalence, ESD Outcomes, and Submucosal Cancer Predictors
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A CNN encoder for modal phase reconstruction in Adaptive Optics systems
No full textPyramid wavefront sensing (pWFS) offers some of the best sensitivity for adaptive optics, but suffers from strong non-linearity. Modulation can extend linear range at the expense of sensitivity. Operating the pyramid without modulation is therefore attractive, but remains challenging. We develop a non-linear CNN reconstructor for pyramid wavefront sensing that maps pWFS images directly to a modal phase representation, and we assess simple hybrid methods combining it with a standard linear least-squares (LS) reconstructor. Using the end-to-end COMPASS simulator, we generate a large open-loop dataset spanning wide ranges of RMS and power spectra to train a compact CNN encoder. We then compare the CNN against an LS baseline and evaluate hybrid schemes in closed-loop simulations over a grid of guide-star magnitudes and Fried parameters, reporting long-exposure Strehl at lambda=1.6 um with controller gain re-optimized per method and bin. We also report preliminary offline bench tests on SCExAO. The CNN reduces open-loop reconstruction error and, in closed loop, outperforms LS across most (magnitude, r_0) conditions, with the largest gains for faint stars where it often closes the loop while LS does not. In very strong turbulence, LS can exceed the CNN; in these cases the hybrid methods are necessary to surpass LS, with a second-stage NN performing best. Inference is real-time capable and the hybrid overhead is negligible. Bench snapshots on SCExAO show successful correction of small static/slow perturbations, with instability for stronger/faster cases. A compact CNN can be trained to perform modal reconstruction for a non-modulated pWFS and improves performance over a classical linear reconstructor in most regimes. When the CNN alone is not optimal, simple hybrid methods achieve the best performance, suggesting a practical way to exploit the pyramid’s sensitivity without modulation
Cats, dogs, and sticky worms: invasion by land flatworms (Geoplanidae) is facilitated by household pets
No full textInternational audienceBackground It is well known that the main vector of invasion by land flatworms has been the export of potted plants from their countries of origin to the invaded country. Within the invaded country, transport to garden centres where the plants are sold, and transport to the buyer’s garden, are also carried out by humans. However, it is less clear how flatworms can then invade neighbouring gardens, given their slow movement rates. Methods We re-examined citizen science reports in metropolitan France received over more than 12 years (2013–2025), searching the 6500 original emails for keywords suggesting transport by pets. Results We found 15 citizen science observations of cats (13) or dogs (2) with flatworms stuck to their fur. Surprisingly, all reports concerned the species Caenoplana variegata , the two-tone planarian, even though this species is not the most abundant in gardens in France. Over the period 2020–2024, observations of C. variegata on dogs and cats represented 7.3% (10/137) of reports. Discussion We suspect that transport by domestic animals is a significant factor favouring invasion by C. variegata , which possesses a particularly sticky mucus adapted to arthropod predation. This is compounded by the fact that the species reproduces asexually in Europe, and therefore the transport of a single individual may be sufficient to facilitate an invasion. We calculated a conservative estimate of the distances travelled outdoors by all the dogs and cats in France, which was 18 billion km/year; if only a tiny proportion of these journeys involve pets carrying flatworms, this transport as a dispersal factor becomes entirely plausible. Conclusions We believe that animal transport is a significant factor favouring land flatworm invasion, but that this does not apply to all species. A citizen science initiative could provide a better understanding of the extent and importance of animal transport as a factor for land flatworm invasions in other countries
Evolutionary Advantage of Diversity-Generating Retroelements in Switching Environments
No full textInternational audienceDiversity-Generating Retroelements (DGRs) create rapid, targeted variation within specific genomic regions in phages and bacteria. They operate through stochastic retro-transcription of a template region (TR) into a variable region (VR), which typically encodes ligand-binding proteins. Despite their prevalence, the evolutionary conditions that maintain such hypermutating systems remain unclear. Here we introduce a two-timescale framework separating fast VR diversification from slow TR evolution, allowing the dynamics of DGR-controlled loci to be analytically understood from the TR design point of view. We quantity the fitness gain provided by the diversification mechanism of DGR in the presence of environmental switching with respect to standard mutagenesis. Our framework accounts for observed patterns of DGR activity in human-gut Bacteroides and clarifies when constitutive DGR activation is evolutionarily favored
NKCC1 as a signaling hub regulating KCC2 stability, chloride homeostasis, and seizure susceptibility
No full textAbstract Chloride homeostasis relies on the dynamic balance between the neuronal co-transporters NKCC1 and KCC2. We reveal an unexpected mechanism by which NKCC1 governs KCC2 membrane stability. NKCC1 clusters recruits SPAK and PP1 to dynamically trap KCC2, compensating for its lack of a direct SPAK-binding site. Single-particle tracking shows that these NKCC1-rich assemblies operate as signaling hubs, enabling either SPAK-driven KCC2 phosphorylation and its membrane destabilization or PP1-mediated dephosphorylation of SPAK and KCC2 membrane stabilization. Peptides that activate SPAK by engaging NKCC1’s PP1-binding motif lower KCC2 surface levels and reduce chloride extrusion, whereas a SPAK-inhibiting peptide prevents SPAK recruitment to NKCC1, stabilizes KCC2 in membrane clusters, and enhances chloride extrusion. An optimized peptide analog preserves KCC2 clustering under hyperexcitable conditions, reduces seizure frequency and severity in PTZ-induced epilepsy, and suppresses ictal activity in human epileptic tissue. These findings identify NKCC1-KCC2 coupling as a central regulatory axis for inhibitory signaling, and position our peptides as promising therapeutic candidates to restore chloride homeostasis in epilepsy and other disorders marked by impaired KCC2 membrane stability
Locomotor reassessment of Iguanodon, Ouranosaurus and Lurdusaurus (Dinosauria, Ornithopoda) using osteological correlates
No full textInternational audienceLarge ornithopod dinosaurs have been successively described as quadrupeds, bipeds and facultative bipeds. Here we study the case of three ankylopollexians (Iguanodon bernissartensis, Ouranosaurus nigeriensis and Lurdusaurus arenatus) for which locomotion remains debated. We examine in detail their appendicular skeleton, focusing on osteological features that were previously associated with either bipedality or quadrupedality in dinosaurs. We compare our observations with data obtained for 12 saurischians and 32 ornithischians whose bipedal or quadrupedal locomotion is unambiguous. Iguanodon and Ouranosaurus score as quadrupeds for nine of the eleven correlates used in this study and are therefore best interpreted as obligate quadrupeds-contrasting with previous hypotheses of facultative bipedalism in Ankylopollexia-although this is sensitive to how hadrosaur locomotion is assessed. Lurdusaurus is found among quadrupeds for all the osteological correlates employed and is thus considered as an obligate quadruped, implying that obligate quadrupedality in ornithopods arose long before the hadrosaurs. Moreover, its extreme humeral and femoral eccentricity, along with its very short metatarsus, indicate graviportality, making Lurdusaurus the first graviportal ornithopod. Further biomechanical investigations are definitely needed to fully appreciate the locomotion of this unique taxon. Osteological correlates appear to be useful tools for investigating the transition to quadrupedalism in ornithopods, and may provide a basis for more comprehensive reconstructions of locomotor and postural evolution across diverse dinosaur lineages
Dimensionality Control in Superlattices from Copper Sulfide Nanocrystals
No full textInternational audienceThree-dimensional nanocrystal superlattices have garnered considerable research interest due to their remarkable collective properties and promising applications. The control of the dimensionality of superlattices remains a significant challenge, with no established synthetic protocol to tune the shape of superlattices. The present article manifests a straightforward and efficient single-step chemical synthesis route for modulating the dimensionality of Cu1.8S nanocrystals superlattices. The resulting superlattices exhibit distinct stability within several solvents (hexane, toluene and benzene) over an extended period of several months. Furthermore, we unveil the growth mechanism of these superlattices through comprehensive small-angle X-ray scattering (SAXS) experiments. This method addresses several drawbacks (multi step synthesis, structural fragility, reproducibility, long-range order instability, etc) associated with previously reported self-assembly methods, the superlattices generated by this technique are efficient to fabricate devices in the future.</div
Comment on “Influence of layer thickness on time domain Brillouin scattering oscillation amplitude in multilayer films” [J. Appl. Phys. 136, 225302 (2024)]
No full textInternational audiencePicosecond acoustics allows for the probing of multilayered nanometric structures, with applications in various fields of fundamental research. In a recent study, Zhang et al.1 have reexamined the optical cavity effect that impacts time-domain Brillouin acoustic spectroscopy (TDBS) in such systems. This interference phenomenon arises from Fabry–Pérot cavities formed by the parallel interfaces within the stack. This has long been modeled either through a general solution based on Green’s functions or via analytical expressions derived from standard Fresnel formulas. In their study, Zhang et al. examined the Brillouin signal in a series of amorphous SiO2 layers grown on a Si wafer and capped with a metal Al transducer. This configuration had been thoroughly investigated as part of a larger effort to study high-frequency acoustic losses in silica glass by Ayrinhac et al. in Ref. 2. However, when attempting to reproduce these results, Zhang et al. failed to achieve quantitative agreement with the calculated expectations, due to poorly characterized samples and likely inadequate data processing. We show that simple optical reflectance measurements combined with appropriate data normalization can, in fact, fully account for such observations
HALO I: Photometric continuum reverberation mapping of Fairall 9
No full textInternational audienceWe investigate the origin of inter-band continuum time delays in active galactic nuclei (AGNs) to study the structure and properties of their accretion disks. We aim to measure the inter-band continuum time delays through photometric monitoring of Seyfert galaxy Fairall 9 to construct the lag-spectrum. Additionally, we explain the observed features in the Fairall 9 lag-spectrum and discuss the potential drivers behind them, based on our newly collected data from the Obserwatorium Cerro Murphy (OCM) telescope. We initiated a long-term, continuous AGN photometric monitoring program in 2024, titled 'Hubble constant constraints through AGN Light curve Observations' (HALO) using intermediate and broad band filters. Here, we present the first results from HALO, focusing on photometric light curves and continuum time-delay measurements for Fairall 9. To complement these observations and extend the wavelength coverage of the lag-spectrum, we also reanalyzed archival Swift light curves and spectroscopic data available in the literature. Using HALO and Swift light curves, we measured inter-band continuum delays to construct the lag-spectrum of Fairall 9. Excess lags appear in the and bands (Balmer continuum contamination) and in the band (Paschen jump/dust emission from the torus). Overall, the lag-spectrum deviates significantly from standard disk model predictions. We find that inter-band delays deviate from the power-law, due to BLR scattering, reprocessing, and dust contributions at longer wavelengths. Power-law fits are therefore not well suited for characterizing the nature of the time delays
