Estimation haute résolution des nombres d'onde dans un guide d'onde océanique dispersif

International audienceLa propagation acoustique en petit fond et aux basses fréquences est décrite par la somme des modes d'un guide d'onde dispersif. Les propriétés physiques du milieu (sédiment, hauteur de la colonne d'eau, etc.) peuvent être inversées à partir des nombres d'onde. Une manière d'estimer ces nombres d'onde consiste à tracer un diagramme f − k (fréquence-nombre d'onde) : c'est le module des transformées de Fourier spatiale et temporelle (TF2D) des signaux reçus sur une antenne horizontale. Cette méthode présente plusieurs limitations liées à l'utilisation de la transformée de Fourier, en particulier, un nombre important de capteurs est requis pour une résolution acceptable des nombres d'onde. L'objectif de ce travail est de réduire le nombre d'hydrophones tout en gardant une bonne séparation des nombres d'onde. Nous proposons d'utiliser un modèle autorégressif des signaux de l'antenne. Le nombre minimal de capteurs nécessaires pour garantir une bonne séparation modale est choisi sur un diagramme de stabilisation. Les diagrammes f −k obtenus par modélisation autorégressive sont tracés pour des données simulées dans un guide de Pekeris et des mesures en mer du Nord. Les diagrammes f−k obtenus par le modèle AR présentent des résolutions modales supérieures tout en utilisant un nombre moindre de capteurs que ceux obtenus par TF2

Joule overheating poisons the fractional ac Josephson effect in topological Josephson junctions

Topological Josephson junctions designed on the surface of a 3D-topological insulator (TI) harbor Majorana bound states (MBS's) among a continuum of conventional Andreev bound states. The distinct feature of these MBS's lies in the $4\pi$-periodicity of their energy-phase relation that yields a fractional ac Josephson effect and a suppression of odd Shapiro steps under $r\!f$ irradiation. Yet, recent experiments showed that a few, or only the first, odd Shapiro steps are missing, casting doubts on the interpretation. Here, we show that Josephson junctions tailored on the large bandgap 3D TI Bi$_2$Se$_3$ exhibit a fractional ac Josephson effect acting on the first Shapiro step only. With a modified resistively shunted junction model, we demonstrate that the resilience of higher order odd Shapiro steps can be accounted for by thermal poisoning driven by Joule overheating. Furthermore, we uncover a residual supercurrent at the nodes between Shapiro lobes, which provides a direct and novel signature of the current carried by the MBS. Our findings showcase the crucial role of thermal effects in topological Josephson junctions and lend support to the Majorana origin of the partial suppression of odd Shapiro steps.Comment: Revised article and Supplemental materia

EMEA and Gene Therapy Medicinal Products Development in the European Union

The evaluation of quality, safety, and efficacy of medicinal products by the European Medicines Evaluation Agency (EMEA) via the centralized procedure is the only available regulatory procedure for obtaining marketing authorization for gene therapy (GT) medicinal products in the European Union. The responsibility for the authorization of clinical trials remains with the national competent authorities (NCA) acting in a harmonized framework from the scientific viewpoint. With the entry into force of a new directive on good clinical practice implementation in clinical trials as of 1 May 2004, procedural aspects will also be harmonized at EU level. Scientifically sound development of medicinal products is the key for the successful registration of dossiers and for contributing to the promotion and protection of public health. The objective of this paper is to introduce the EMEA regulatory processes and scientific activities relevant to GT medicinal products

Intensity Control in GANIL's Experimental Rooms

TUPF31International audienceThe safety re-examination of existing GANIL facilities requires the implementation of a safety system which makes a control of the beam intensity sent to the experimental rooms possible. The aim is to demonstrate that beam intensities stay below the authorized limits defined by the safety GANIL group. The challenge is to be able to measure by a non-interceptive method a wide range of beam intensities from 5nA to 5 A with a maximum uncertainty of 5%, independently of the frequency (from 7 to 14.5MHz) and the beam energy (from 1.2 to 95MeV.A). After a comparative study, two types of high frequency diagnostics were selected, the capacitive pick-up and the fast current transformer. This paper presents the signal simulations from diagnostics with different beam energies, the uncertainty calculations and the results of the first tests with beam

Private Sector and Waste Management in Delhi: A Political Economy Perspective

Due to their size and rapid growth, large cities in developing countries are increasingly challenged by burgeoning waste generation. Waste management, however, has traditionally provided employment opportunities to the many urban poor in the informal sector. These traditional models, working largely in parallel with state?led interventions, are under pressure because they fail to address the waste management crisis. This failure, coupled with the lack of capacities of local governments, has paved the way for formal private sector participation. We examine the case of Delhi where a complex interplay of competing approaches have accompanied efforts of urban local bodies, civil society and the private sector (informal and formal) at finding a sustainable working solution. Our analysis of the complex relationship within the private sector players, and between private and public actors, provides novel insights into potential contribution of public–private partnerships for effective waste management in developing countries

Electoral Performance and Policy Choices in the Front National

This article proposes a two-level analysis of the Front National (FN) in the 2017 French presidential and parliamentary elections. The first level focuses on the electoral performances of Marine Le Pen and the FN and analyses both elections in terms of gains and losses at the polls. The second level considers FN policy and argues that the party went into these elections with a programme targeting both left- and right-leaning voters, attempting a policy synthesis that partly fitted and partly subverted Kirchheimer’s paradigm of the ‘catch-all’ party. Both levels of analysis link to a number of strategic considerations prompting debate within the party over the direction to take in order to improve its future electoral prospects

Genome-wide association mapping for root traits in a panel of rice accessions from Vietnam

Background: Despite recent sequencing efforts, local genetic resources remain underexploited, even though they carry alleles that can bring agronomic benefits. Taking advantage of the recent genotyping with 22,000 single-nucleotide polymorphism markers of a core collection of 180 Vietnamese rice varieties originating from provinces from North to South Vietnam and from different agrosystems characterized by contrasted water regimes, we have performed a genome-wide association study for different root parameters. Roots contribute to water stress avoidance and are a still underexploited target for breeding purpose due to the difficulty to observe them. Results: The panel of 180 rice varieties was phenotyped under greenhouse conditions for several root traits in an experimental design with 3 replicates. The phenotyping system consisted of long plastic bags that were filled with sand and supplemented with fertilizer. Root length, root mass in different layers, root thickness, and the number of crown roots, as well as several derived root parameters and shoot traits, were recorded. The results were submitted to association mapping using a mixed model involving structure and kinship to enable the identification of significant associations. The analyses were conducted successively on the whole panel and on its indica (115 accessions) and japonica (64 accessions) subcomponents. The two associations with the highest significance were for root thickness on chromosome 2 and for crown root number on chromosome 11. No common associations were detected between the indica and japonica subpanels, probably because of the polymorphism repartition between the subspecies. Based on orthology with Arabidopsis, the possible candidate genes underlying the quantitative trait loci are reviewed. Conclusions: Some of the major quantitative trait loci we detected through this genome-wide association study contain promising candidate genes encoding regulatory elements of known key regulators of root formation and development

Development and validation of a liquid chromatography coupled to mass spectrometer (LC-MS) method for the simultaneous quantification of estrone-3-sulfate, progesterone, estrone and estradiol in serum of mares and American bisons

peer reviewedSteroid concentrations in serum are fluctuating during pregnancy of many mammal species. The current knowledge about endocrinology of gestation is mainly based on immunoassays. However, the lack of specificity of these assays hampers the reliability of the results. In the present work, we developed and validated a methodology associating liquid chromatography (LC) and mass spectrometry (MS) to simultaneously quantify, with high specificity and accuracy, estrone-3-sulfate (E3S), progesterone (PRO), estrone (E1) and estradiol (E2) in serum of two different mammal species. The sample preparation procedure is based on a simple protein precipitation and a derivatization with dansyl chloride. After the chromatographical separation, compounds were analyzed with a triple-quadrupole mass spectrometer operating in multiple reaction monitoring. Mare and American bison serum samples were analyzed with the validated method and results were compared with concentrations measured with commercial radioimmunoassay (RIA), enzyme linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA). Following these criterions: relative standard deviation <15% and relative bias <15%, lower limits of quantification of 0.5 ng/mL (E3S), 0.1 ng/mL (PRO) and 2 pg/mL (E1 and E2) were achieved. Most of the comparison between immunoassays and LC-MS showed poor correlation and proportional differences. Our LC-MS method is able to simultaneously quantify several steroid hormones with high specificity, accuracy and sensitivity in serum of two different mammal species. Our method constitutes a useful and performant tool for veterinary clinicians and LC-MS should thus be used to update and refine the current knowledge about the endocrinology of pregnancy in mammals