Comparaison de méthodes de décomposition de distributions polymodales de fréquences de longueurs en distributions unimodales successives (Normsep - Mix - Maximums successifs), application aux "bossus" (Pseudotolithus elongatus) du Congo

A partir des mensurations effectuées sur des échantillons de #Pseudotolithus elongatus$ au Congo dans les années 60 et des sous-échantillons récoltés pour l'estimation de l'âge par interprétation des otolithes, nous avons pu comparer les résultats obtenus dans la décomposition des distributions de fréquences de longueurs en distributions unimodales successives par différentes méthodes. La méthode des maximums successifs a donné des résultats pratiquement identiques à celle des "lectures d'âges". Les programmes NORMSEP et MIX ont donné pour leur part des résultats beaucoup plus difficiles à homologuer d'un point de vue biologique en dépit de leurs finesses mathématiques. Les distributions de fréquences de longueurs d'une cohorte étant souvent symétriques, l'application de la méthode des maximums successifs est fortement conseillée en l'absence de certitude sur la normalité. (Résumé d'auteur

Genetic variations within human gained enhancer elements affect human brain sulcal morphology.

The expansion of the cerebral cortex is one of the most distinctive changes in the evolution of the human brain. Cortical expansion and related increases in cortical folding may have contributed to emergence of our capacities for high-order cognitive abilities. Molecular analysis of humans, archaic hominins, and non-human primates has allowed identification of chromosomal regions showing evolutionary changes at different points of our phylogenetic history. In this study, we assessed the contributions of genomic annotations spanning 30 million years to human sulcal morphology measured via MRI in more than 18,000 participants from the UK Biobank. We found that variation within brain-expressed human gained enhancers, regulatory genetic elements that emerged since our last common ancestor with Old World monkeys, explained more trait heritability than expected for the left and right calloso-marginal posterior fissures and the right central sulcus. Intriguingly, these are sulci that have been previously linked to the evolution of locomotion in primates and later on bipedalism in our hominin ancestors

Anterolateral ligament reconstruction does not delay functional recovery, rehabilitation, and return to sport after anterior cruciate ligament reconstruction. A matched-pair analysis from the SANTI (Scientific ACL Network International) Study Group

Purpose: To determine whether the addition of an anterolateral ligament reconstruction (ALLR) resulted in delayed functional recovery (based on the Knee Santy Athletic Return to Sport [K-STARTS] score) at 6 months after anterior cruciate ligament reconstruction (ACLR). Methods: A retrospective analysis of prospectively collected data from consecutive pa- tients who underwent an ACLR between September 2017 and December 2020 was conducted. Patients who received an isolated hamstring autograft (isolated ACLR group) were propensity matched in a 1:1 ratio to patients who received a hamstring autograft ACLR combined with an ALLR (ACLR-ALLR group). Outcome measures included the Tegner Activity Scale and the K-STARTS testda validated composite return-to-sports test (including the Anterior Cruciate LigamenteReturn to Sport After Injury scale, Qualitative Assessment of Single-Leg Landing tool, limb symmetry index, and ability to change direction using the Modified Illinois Change of Direction Test). Results: The study included 111 matched pairs. At 6 months postoperatively, there were no significant differences between groups in the overall K-STARTS score (65.4 for isolated ACLR vs 61.2 for ACLR-ALLR, P 1⁄4 .087) or the Tegner Activity Scale score (3.7 for isolated ACLR vs 3.8 for ACLR-ALLR, P 1⁄4 .45). In addition, an evaluation of the subscales of the K-STARTS score revealed no disadvantage across the domains of neuromuscular control, limb symmetry index, agility, or psychological readiness to return to sport when an ALLR was performed. Conclusions: The addition of ALLR at the time of ACLR does not delay functional recovery. Spe- cifically, at 6 months postoperatively, there was no disadvantage in patients undergoing ALLR-ACLR, when compared with those undergoing isolated ACLR, with respect to neuromuscular control, limb symmetry indices (hop tests), agility, or psychological readiness to return to sport

Background Light in Potential Sites for the ANTARES Undersea Neutrino Telescope

The ANTARES collaboration has performed a series of {\em in situ} measurements to study the background light for a planned undersea neutrino telescope. Such background can be caused by $^{40}$K decays or by biological activity. We report on measurements at two sites in the Mediterranean Sea at depths of 2400~m and 2700~m, respectively. Three photomultiplier tubes were used to measure single counting rates and coincidence rates for pairs of tubes at various distances. The background rate is seen to consist of three components: a constant rate due to $^{40}$K decays, a continuum rate that varies on a time scale of several hours simultaneously over distances up to at least 40~m, and random bursts a few seconds long that are only correlated in time over distances of the order of a meter. A trigger requiring coincidences between nearby photomultiplier tubes should reduce the trigger rate for a neutrino telescope to a manageable level with only a small loss in efficiency.Comment: 18 pages, 8 figures, accepted for publication in Astroparticle Physic

The ANTARES Optical Beacon System

ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

Enhanced deformation of limestone and sandstone in the presence of high pCO2 fluids

International audienceGeological repositories subject to the injection of large amounts of anthropogenic carbon dioxide will undergo chemical and mechanical instabilities for which there are currently little experimental data. This study reports on experiments where low and high pCO2 (8~MPa) aqueous fluids where injected into natural rock samples. The experiments were performed in flow-through triaxial cells, where the vertical and confining stresses, temperature, and pressure and composition of the fluid were separately controlled and monitored. The axial vertical strains of two limestones and one sandstone were continuously measured during separate experiments for several months, with a strain rate resolution of 10^-11 s-1. Fluids exiting the triaxial cells where continuously collected and their compositions analysed. The high pCO2 fluids induced an increase in strain rates of the limestones by up to a factor of 5, compared to the low pCO2 fluids. Injection of high pCO2 fluids into the sandstone resulted in deformation rates one order of magnitude smaller than the limestones. The creep accelerating effect of high pCO2 fluids with respect to the limestones was mainly due to the acidification of the injected fluids, resulting in a significant increase in solubility and reaction kinetics of calcite. Compared to the limestones, the much weaker response of the sandstone was due to the much lower solubility and reactivity of quartz in high pCO2 fluids. In general, all samples showed a positive correlation between fluid flow rate and strain rate. X-ray tomography results revealed significant increases in porosity at the inlet portion of each core; the porosity increases were dependent on the original lithological structure and composition. The overall deformation of the samples is interpreted in terms of simultaneous dissolution reactions in pore spaces and intergranular pressure solution creep