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Near-infrared fundus autofluorescence alterations correlate with swept-source optical coherence tomography angiography findings in patients with retinitis pigmentosa
No full textInternational audienceThirty-eight patients from 37 families with retinitis pigmentosa (RP) underwent macular 6 × 6-mm swept-source optical coherence tomography angiography (SS-OCTA) and 30° near-infrared fundus autofluorescence (NIR-FAF) acquisitions in one eye. Superficial vascular complex (SVC), deep capillary complex (DCC) and choriocapillaris (CC) angiograms were registered with NIR-FAF acquisitions to comparatively assess subjects with and without central area of preserved NIR-FAF (APA). On the subset of patients showing an APA, the vessel densities for SVC and DCC and flow deficits for CC were assessed in three directions (superior, inferior and temporal) from the fovea and compared to healthy 1:1 age-matched controls. Nine patients with no APA had evidence of severe central OCTA alterations at all levels, especially in the DCC. In the other 29 subjects presenting APA, all OCTA parameters were similar to healthy eyes within the APA, where the retina preserves its structural integrity. Outside the APA, both the DCC and CC were significantly reduced in all directions. These alterations are probably related to the outer retinal atrophy outside the APA. Comparing OCTA to other imaging modalities is helpful to determine the potential interest of OCTA findings as an outcome measure for disease status and progression
Mutated CCDC51 Coding for a Mitochondrial Protein, MITOK Is a Candidate Gene Defect for Autosomal Recessive Rod-Cone Dystrophy
No full textInternational audienceThe purpose of this work was to identify the gene defect underlying a relatively mild rod-cone dystrophy (RCD), lacking disease-causing variants in known genes implicated in inherited retinal disorders (IRD), and provide transcriptomic and immunolocalization data to highlight the best candidate. The DNA of the female patient originating from a consanguineous family revealed no large duplication or deletion, but several large homozygous regions. In one of these, a homozygous frameshift variant, c.244_246delins17 p.(Trp82Valfs*4); predicted to lead to a nonfunctional protein, was identified in CCDC51. CCDC51 encodes the mitochondrial coiled-coil domain containing 51 protein, also called MITOK. MITOK ablation causes mitochondrial dysfunction. Here we show for the first time that CCDC51/MITOK localizes in the retina and more specifically in the inner segments of the photoreceptors, well known to contain mitochondria. Mitochondrial proteins have previously been implicated in IRD, although usually in association with syndromic disease, unlike our present case. Together, our findings add another ultra-rare mutation implicated in non-syndromic IRD, whose pathogenic mechanism in the retina needs to be further elucidated
Amorphous Order and Nonlinear Susceptibilities in Glassy Materials
No full textInternational audienceWe review 15 years of theoretical and experimental work on the nonlinear response of glassy systems. We argue that an anomalous growth of the peak value of nonlinear susceptibilities is a signature of growing "amorphous order" in the system, with spin-glasses as a case in point. Experimental results on supercooled liquids are fully compatible with the random first-order transition (RFOT) prediction of compact "glassites" of increasing volume as temperature is decreased, or as the system ages. We clarify why such a behavior is hard to explain within purely kinetic theories of glass formation, despite recent claims to the contrary
Comment sauver l'ouverture de la science ? l'évaluation
No full textIl s'agit d'un document préparatoire pour le groupe de travail science ouverte de l'Académie des Sciences en vue de recommandations de l'Académie afin de soutenir et de mettre en pratique une science ouverte, Juillet 2021Ce document insiste sur le fait que l'évaluation sous toutes ses formes est le noeud du problème de l'ouverture de la scienc
Jean-Marc Drouin (1948-2020)
No full textInternational audienceJean-Marc Drouhin, philosopher and historian of science, born on May 26, 1948 in Paris, died on July 9, 2020, after a long neurodegenerative illness in Rayapudupakkam, a town north of the city of Pondicherry (India).Jean-Marc Drouhin, philosophe et historien des sciences, né le 26 mai 1948 à Paris, est décédé le 9 juillet 2020, au terme d'une longue maladie neuro-dégénérative à Rayapudupakkam, localité située au nord de la ville de Pondichéry (Inde)
Substantial restoration of night vision in adult mice with congenital stationary night blindness
No full textInternational audienceComplete congenital stationary night blindness (cCSNB) due to mutations in TRPM1, GRM6, GPR179, NYX, or leucinerich repeat immunoglobulin-like transmembrane domain 3 (LRIT3) is an incurable inherited retinal disorder characterized by an ON-bipolar cell (ON-BC) defect. Since the disease is nondegenerative and stable, treatment could theoretically be administrated at any time in life, making it a promising target for gene therapy. Until now, adeno-associated virus (AAV)mediated therapies lead to significant functional improvements only in newborn cCSNB mice. Here we aimed to restore protein localization and function in adult Lrit3 À/À mice. LRIT3 localizes in the outer plexiform layer and is crucial for TRPM1 localization at the dendritic tips of ON-BCs and the electroretinogram (ERG)-b-wave. AAV2-7m8-Lrit3 intravitreal injections were performed targeting either ON-BCs, photoreceptors (PRs), or both. Protein localization of LRIT3 and TRPM1 at the rod-to-rod BC synapse, functional rescue of scotopic responses, and ON-responses detection at the ganglion cell level were achieved in a few mice when ON-BCs alone or both PRs and ON-BCs, were targeted. More importantly, a significant number of treated adult Lrit3 À/À mice revealed an ERG b-wave recovery under scotopic conditions, improved optomotor responses, and on-time ON-responses at the ganglion cell level when PRs were targeted. Functional rescue was maintained for at least 4 months after treatment
COVID-19 et médicaments : physiopathologie et pistes thérapeutiques
No full textInternational audienceThis review provides an update on the different therapeutic approaches that have been used to treat SARS-CoV-2 infection, as well as, the resulting paradoxical inflammation disorders.Cette revue fait le point sur les différentes approches thérapeutiques qui ont été suivies pour traiter l’infection à SARS-CoV-2, ainsi que les troubles liés à l’inflammation paradoxale qui en découlent
Energy signature of ton TNT-class impacts: analysis of the 22 December 2018 fireball over Western Pyrenees
No full textInternational audienceAbstract The increase in detector sensitivity and availability in the past three decades has allowed us to derive knowledge of the meteoroid flux and impact energy into the Earth’s atmosphere. We present the multi-instrument detected 22 December 2018 fireball over Western Pyrenees, and compare several techniques aiming to obtain a reliable method to be used when measuring impacts of similar scale. From trajectory data alone, we found a bulk density of 3.5 g/cm3 to be the most likely value for the Pyrenean meteoroid. This allowed to further constrain the dynamic mass, which translated into a kinetic energy of 1 ton TNT (4.184 · 109 J). For the second energy derivation, via the fireball’s corrected optical radiation, we obtained a more accurate empirical relation measuring well studied bolides . The result approximates to 1.1 ton TNT, which is notably close to the nominal dynamic result, and agrees with the lower margin of the seismic-based energy estimation, yet way lower than the infrasound estimate. Based on the relation derived in this study, we consider the nominal estimate from both the dynamic and photometric methods to be the most accurate value of deposited energy (1 ton TNT). We show that the combination of these two methods can be used to infer the meteoroid density. Among the methods presented in this paper, we found that the optical energy is the most reliable predictor of impact energy near the ton TNT-scale
A new spin on optimal portfolios and ecological equilibria
No full textInternational audienceWe consider the classical problem of optimal portfolio construction with the constraint that no short position is allowed, or equivalently the valid equilibria of multispecies Lotka-Volterra equations, in the special case where the interaction matrix is of unit rank, corresponding to a single-resource MacArthur model. We compute the average number of solutions and show that its logarithm grows as N α , where N is the number of assets or species and α ≤ 2 3 depends on the interaction matrix distribution. We conjecture that the most likely number of solutions is much smaller and related to the typical sparsity m(N) of the solutions, which we compute explicitly. We also find that the solution landscape is similar to that of spin-glasses, i.e. very different configurations are quasi-degenerate. Correspondingly, "disorder chaos" is also present in our problem. We discuss the consequence of such a property for portfolio construction and ecologies, and question the meaning of rational decisions when there is a very large number "satisficing" solutions
