Mobility of daughter elements of U-238 decay chain during leaching by In Situ Recovery (ISR) : New insights from digital autoradiography

In highly permeable sedimentary rock formations, U extraction by in-situ leaching techniques (ISR - In-Situ Recovery) is generally considered to have a limited environmental impact at ground level. Significantly, this method of extraction produces neither mill tailings nor waste rocks. Underground, however, the outcome for U-238 daughter elements in aquifers is not well known because of their trace concentrations in the host rocks. Thus, understanding the in-situ mobility of these elements remains a challenge. Two samples collected before and after six months of ISR experiments (Dulaan Uul, Mongolia) were studied with the help of a digital autoradiography technique (DA) of alpha particles, bulk alpha spectrometry, and complementary petrographic observation methods. These techniques demonstrate that before and after leaching, the radioactivity is concentrated in altered and microporous Fe-Ti oxides. Most of the daughter elements of U remain trapped in the rock after the leaching process. DA confirms that the alpha activity of the Fe-Ti oxides remains high after uranium leaching, and the initial secular equilibrium of the U-238 series for Th-230 to Po-210 daughter elements (including Ra-226) of the fresh rocks is maintained after leaching. While these findings should be confirmed by more systematic studies, they already identify potential mechanisms explaining why the U-daughter concentrations in leaching water are low.Peer reviewe

Directional detection of meV dark photons with Dandelion

This paper presents Dandelion, a new dish antenna experiment searching for dark photons (DPs) with masses around the meV that will start acquiring data by the end of 2023. A spherical mirror acts as a conversion surface between DPs and standard photons that converge to a matrix of 418 Kinetic Inductance Detectors cooled down to 150 mK. A tilt of the mirror at 1 Hz moves the expected signal over the pixels thus enabling a continuous background measurement. The expected signal has two modulations: a spatial modulation providing a directional signature for the unambiguous discovery of a DP, and an intensity modulation allowing the determination of the polarization of the DP. For masses near the meV, the inflationary production of longitudinal and transverse DPs are mutually excluded, thus the polarization determination by Dandelion could shed a new light on the inflation phase of the early universe. A first Dandelion prototype operating for 30 days would improve by more than one order of magnitude the current exclusion limits on DPs at the meV mass scale and would probe this region with an unprecedented discovery potential based on directional detection.Comment: 17 pages, 7 figure

A new minimally invasive heart surgery instrument for atrial fibrillation treatment : first in vitro and animal tests.

International audienceThe paper presents a new robotic system for beating heart surgery. The final goal of this project is to develop a tele-operated system for the thoracoscopic treatment of patients with atrial fibrillation. The system consists of a robot that moves an innovative end-effector used to perform lines as in the Cox-Maze technique. This device is an electrode mesh that is introduced in the thorax through a trocar and is deployed inside the left atrium, where it can create selective ablation lines at any atrial region, using radio frequency. The current version of the umbrella has 22 electrodes. Using visual feedback from an ultrasound based navigation system, the surgeon can choose which electrodes on the mesh to activate. Once the umbrella is in contact with the endocardium of the left atrium, at the expected position, the surgeon activates the chosen electrodes sequentially. The umbrella can then be moved to another position. In vitro and in vivo animal tests have been carried out in order to test and improve the instrument, the robotic system and the operative procedure

Does biological maturity actually confound gender-related differences in physical activity in preadolescence?

Aim To examine: (i) if maturity-related gender differences in moderate-to-vigorous physical activity (MVPA) depend on how maturity status is defined and measured; and (ii) the influence of maturity level on compliance with PA recommendations. Methods The study involved 253 children (139 boys) aged 9.9 ± 0.9 years, with mean stature and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg respectively. Their PA was evaluated using an Actigraph accelerometer (Model 7164). Maturity was assessed using the estimated age at peak height velocity (APHV) and a standardized APHV by gender (i.e. centred APHV). Results Boys engaged in significantly more MVPA than girls (P < 0.0001). There was a significant correlation between the centred APHV and MVPA in boys (r = 0.20; P = 0.016), but not in girls (r = 0.13; P = 0.155). An ancova controlling for the estimated APHV showed no significant interactions between gender and APHV, and the main effect of gender on MVPA was negated. Conversely, there was a significant main effect of APHV on MVPA (F 1,249 = 6.12; P = 0.014; η p 2 = 0.024). Only 9.1% of children met the PA recommendations, including 14.4% of boys and 2.6% of girls (P < 0.01). This observation also applies in both pre-APHV (12.7% of boys vs. 2.4% of girls, P < 0.001) and post-APHV children (23.8% of boys vs. 3.4% of girls, P < 0.0001). No differences in PA guidelines were observed between pre-APHV and post-APHV children. Conclusions Among prepubescent children, the influence of biological maturity on gender differences in PA may be a function of how maturity status is determined. The most physically active prepubescent children were those who were on time according to APHV

La Plume et le Goupillon. L’écrivain catholique en question aux XXe et XXIe siècles

            Souvent utilisée par la critique dans le champ littéraire français des XXe et XXIe siècles, l’appellation « écrivain catholique » est éminemment problématique. Elle a rarement été reconnue par les écrivains ainsi baptisés, et résulte surtout d’une construction historique, à laquelle ont contribué tous les acteurs du champ littéraire — revues, éditeurs, institutions diverses. Le présent ouvrage, auquel ont collaboré une vingtaine de spécialistes, se propose d’étudier les enjeux de cette étiquette confessionnelle, en trois temps — d’abord le processus de son émergence, ensuite certains des principaux débats et combats qu’elle a suscités, enfin les réactions des écrivains présumés « catholiques » eux-mêmes, entre revendication et défiance

Electrical properties of AlNxOy thin films prepared by reactive magnetron sputtering

Direct current magnetron sputtering was used to produce AlNxOy thin films, using an aluminum target, argon and a mixture of N2+O2 (17:3) as reactive gases. The partial pressure of the reactive gas mixture was increased, maintaining the discharge current constant. Within the two identified regimes of the target (metallic and compound), four different tendencies for the deposition rate were found and a morphological evolution from columnar towards cauliflower-type, ending up as dense and featureless-type films. The structure was found to be Al-type (face centered cubic) and the structural characterization carried out by X-ray 2 diffraction and transmission electron microscopy suggested the formation of an aluminumbased polycrystalline phase dispersed in an amorphous aluminum oxide/nitride (or oxynitride) matrix. This type of structure, composition, morphology and grain size, were found to be strongly correlated with the electrical response of the films, which showed a gradual transition between metallic-like responses towards semiconducting and even insulating-type behaviors. A group of films with high aluminum content revealed a sharp decrease of the temperature coefficient of resistance (TCR) as the concentration ratio of non-metallic/aluminum atomic ratio increased. Another group of samples, where the non-metallic content became more important, revealed a smooth transition between positive and negative values of TCR. In order to test whether the oxynitride films have a unique behavior or simply a transition between the typical responses of aluminum and of those of the correspondent nitride and oxide, the electrical properties of the ternary oxynitride system were compared with AlNx and AlOy systems, prepared in similar conditions.This research is sponsored by FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade, by the national funds through FCT-Fundação para a Ciência e a Tecnologia, under the project PTDC/CTM-NAN/112574/2009 and Programa Pessoa 2010/2011 Cooperação Portugal/França, Proc.º 441.00, Project“COLOURCLUSTER”. J. Borges also acknowledges FCT financial support under PhD grant no. SFRH/BD/47118/2008

Dark Matter Directionality Detection performance of the Micromegas-based μ\muTPC-MIMAC detector

Directional Dark Matter Detection (DDMD) can open a new signature for Weakly Massive Interacting Particles (WIMPs) Dark Matter. The directional signature provides in addition, an unique way to overcome the neutron and neutrino backgrounds. In order to get the directional signature, the DDM detectors should be sensitive to low nuclear energy recoils in the keV range and have an angular resolution better than $20^{\circ}$. We have performed experiments with low energy ($<30\,\mathrm{keV}$) ion beam facilities to measure the angular distribution of nuclear recoil tracks in a MIMAC detector prototype. In this paper, we study angular spreads with respect to the electron drift direction ($0^{\circ}$ incident angle) of Fluorine nuclear tracks in this low energy range, and show nuclear recoil angle reconstruction produced by a monoenergetic neutron field experiment. We find that a high-gain systematic effect leads to a high angular resolution along the electron drift direction. The measured angular distribution is impacted by diffusion, and space charge or ion feedback effects, which can be corrected for by an asymmetry factor observed in the flash-ADC profile. The estimated angular resolution of the $0^{\circ}$ incident ion is better than $15^{\circ}$ at $10$ keV kinetic energy and agrees with the simulations within $20$%. The distributions from the nuclear recoils have been compared with simulated results based on a modified Garfield++ code. Our study shows that protons would be a more adapted target than heavier nuclei for DDMD of light WIMPs. We demonstrate that directional signature from the Galactic halo origin of a Dark Matter WIMP signal is experimentally achievable, with a deep understanding of the operating conditions of a low pressure detector with its diffusion mechanism.Comment: 19 pages, 12 figure

Incentives for smoking cessation during pregnancy:an ethical framework

INTRODUCTION: Smoking during pregnancy increases the risk of morbidity and mortality of the mother and child. The inability of the unborn child to protect itself, raises the social and academic responsibility to protect the child from the harmful effects of smoking. Interventions including rewards ('incentives') for lifestyle changes are an upcoming trend and can encourage women to quit smoking. However, these incentives can, as we will argue, also have negative consequences, for example the restriction of personal autonomy and encouragement of smoking to become eligible for participation. To prevent these negative consequences, we developed an ethical framework that enables to assess and address unwanted consequences of incentive-based interventions whereby moral permissibility can be evaluated. METHODS: The possible adverse consequences of incentives were identified through an extensive literature search. Subsequently, we developed ethical criteria to identify these consequences based on the biomedical ethical principles of Beauchamp and Childress. RESULTS: Our framework consists of twelve criteria. These criteria concern (i) effectiveness, (ii) support of a healthy lifestyle, (iii) motivational for the target population, (iv) stimulating unhealthy behaviour, (v) negative attitudes, (vi) personal autonomy, (vii) intrinsic motivation, (viii) privacy, (ix) fairness, (x) allocation of incentives, (xi) cost-effectiveness, and (xii) health inequity. Based on these criteria, the moral permissibility of potential interventions can be evaluated. CONCLUSION: Incentives for smoking cessation are a response to the responsibility to protect the unborn child. But these interventions might have possible adverse effects. This ethical framework aims to identify and address ethical pitfalls in order to avoid these adverse effects

Rectal atresia and rectal stenosis:the ARM-Net Consortium experience

Purpose: To assess the number, characteristics, and functional short-, and midterm outcomes of patients with rectal atresia (RA) and stenosis (RS) in the ARM-Net registry. Methods: Patients with RA/RS were retrieved from the ARM-Net registry. Patient characteristics, associated anomalies, surgical approach, and functional bowel outcomes at 1 and 5-year follow-up were assessed. Results: The ARM-Net registry included 2619 patients, of whom 36 (1.3%) had RA/RS. Median age at follow-up was 7.0 years (IQR 2.3–9.0). Twenty-three patients (63.9%, RA n = 13, RS n = 10) had additional anomalies. PSARP was the most performed reconstructive surgery for both RA (n = 9) and RS (n = 6) patients. At 1-year follow-up, 11/24 patients with known data (45.8%, RA n = 5, RS n = 6) were constipated, of whom 9 required stool softeners and/or laxatives. At 5-year follow-up, 8/9 patients with known data (88.9%, RA n = 4, RS n = 4) were constipated, all requiring laxatives and/or enema. Conclusion: RA and RS are rare types of ARM, representing 1.3% of patients in the ARM-Net registry. Additional anomalies were present in majority of patients. Different surgical approaches were performed as reconstructive treatment, with constipation occurring in 46% and 89% of the patients at 1 and 5-year follow-up. However, accurate evaluation of long-term functional outcomes remains challenging.</p

Julien Green et la hantise de l’imposture

Young author of a religious pamphlet, Julien Green suspected an ethical and aesthetic imposture in this literary positioning. The desire for truth allows him to profess his faith, but the autobiographical confidences are subjected to complex requirements. For his novels, gushing out from the depths of the psyche, he rejects the catholic label: the spiritual sense of a writing that explores the darkness of the human condition paradoxically depends on the renunciation of any apologetic purpose