Transmission RZ de 40x40 Gbit/s sur 3 pas de 40 dB de Fibre Standard avec 27.4 dB de Gain Raman contra-propagatif et un EDFA de 27 dBm

session V « Systèmes de télécommunication » [502]National audienceLes amplificateurs EDFA forte puissance semblent de bons candidats pour des liaisons festons DWDM. Nous démontrons expérimentalement la transmission de 40 canaux à 40 Gbit/s sur la bande C sur 3 pas de 40 dB de pertes avec une modulation RZ classique

Reproductive Technologies and Genomic Selection in Cattle

The recent development of genomic selection induces dramatic changes in the way genetic selection schemes are to be conducted. This review describes the new context and corresponding needs for genomic based selection schemes and how reproductive technologies can be used to meet those needs. Information brought by reproductive physiology will provide new markers and new improved phenotypes that will increase the efficiency of selection schemes for reproductive traits. In this context, the value of the reproductive techniques including assisted embryo based reproductive technologies (Multiple Ovaluation Embryo Transfer and Ovum pick up associated to in vitro Fertilization) is also revisited. The interest of embryo typing is discussed. The recent results obtained with this emerging technology which are compatible with the use of the last generation of chips for genotype analysis may lead to very promising applications for the breeding industry. The combined use of several embryo based reproductive technologies will probably be more important in the near future to satisfy the needs of genomic selection for increasing the number of candidates and to preserve at the same time genetic variability

Analysis of the Variable Geometry Effect in Radial Turbines

The influence of variable geometry stators on the stage behavior is analyzed from both theoretical and experimental points of view. A theoretical analysis of the trajectory of some pressure-ratio lines in a loading-to-flow-coefficient diagram leads to the definition of a specific dimensionless parameter: the reduced section. This parameter is representative of the stator geometric configuration and is thus expected to be a good candidate to describe the variable geometry problem. From a theoretical point of view, this parameter is no less than the formal expression of the link between the geometric configuration of the stator and the behavior of the stage. An experimental approach decomposed in three phases is then led to evaluate this assessment. The results clearly demonstrate the crucial influence of the reduced section in the operating point definition. It leads to the conclusion that from a theoretical point of view, the two solutions mainly used in the industry for variable geometry stages (variation of the height or of the opening position of the stator blades) are equivalent provided that they are sanitized of their respective technological drawbacks. It has also been shown that the geometric configuration of the stator chosen to reach a specific value of the reduced section has some incidence on the efficiency of the stage. This observation gives some opportunities for optimization, for which some axis of reflection is given

Méthodologie de collecte de données et d'estimation des efforts et débarquements des pêcheries côtières

Du fait de son importance à l’échelle française et européenne, le suivi des efforts et débarquements de la petite pêche côtière est un enjeu fort pour l’évaluation des pêcheries et la gestion durable des écosystèmes marins. Or, ces flottilles souffrent chroniquement d’un manque de données, notamment de données déclaratives. De plus, elles sont en général caractérisées par une forte polyvalence en termes de métiers et engins pratiqués, une forte dispersion sur le littoral ainsi qu’une forte variabilité d’activité, ce qui rend souvent leur suivi difficile. C’est ainsi que le Système d’Informations Halieutiques (SIH) de l’Ifremer a mis en place au milieu des années 2000 un programme d’observation des marées aux débarquements (OBSDEB), afin de collecter de la donnée relative à ces pêcheries côtières. Ce document présente la méthodologie employée pour recueillir les échantillons et construire les estimations des efforts et débarquements de ces pêcheries côtières. Modifications au 18/04/2020 : - Affinement de la méthodologie d’estimation du nombre de marées par les calendriers hebdomadaires (Martinique, Réunion et Méditerranée). - Affinement du module de calcul des prix moyens OBSDEB

L'evolution des virus a ARN: roles de la selection et de la derive genetique

RNA viruses, retroviruses and pararetroviruses, are known for their rapid evolution, because of high mutation rates and short generation times. Replication errors (mutations and imperfect recombinations) generate a great variability. However, selection pressures shape viral populations diversity, by acting at different steps of virus infectious cycle : strategies of genome expression, interactions with host(s) and vector(s) are the targets of selection. Such a selection sorts out genotypes according to their fitness. The second most important parameter acting on viral population diversity, genetic drift, occurs when population effective size is low, which seems to be frequent during host or tissue infection initiation. By contrast to selection, drift is a random, fitness‐independent process, which may lead to the fixation of deleterious mutations. Despite their exceptionally high mutation rates, RNA viruses seem to follow classical population genetics principles, as showed during the last two decades.http://www.john-libbey-eurotext.fr/en/revues/bio_rech/vir/e-docs/00/04/04/91/resume.md?type=text.htm

Experimental Estimate of the Abundance and Effects of Nearly Neutral Mutations in the RNA Virus φ6

Although the frequency and effects of neutral and nearly neutral mutations are critical to evolutionary patterns and processes governed by genetic drift, the small effects of such mutations make them difficult to study empirically. Here we present the results of a mutation-accumulation experiment designed to assess the frequencies of deleterious mutations with undetectable effects. We promoted the accumulation of spontaneous mutations by subjecting independent lineages of the RNA virus φ6 to repeated population bottlenecks of a single individual. We measured fitness following every bottleneck to obtain a complete picture of the timing and effects of the accumulated mutations with detectable effects and sequenced complete genomes to determine the number of mutations that were undetected by the fitness assays. To estimate the effects of the undetected mutations, we implemented a likelihood model developed for quantitative trait locus (QTL) data (Otto and Jones 2000) to estimate the number and effects of the undetected mutations from the measured number and effects of the detected mutations. Using this method we estimated a deleterious mutation rate of U = 0.03 and a gamma effects distribution with mean \documentclass[10pt]{article} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{pmc} \pagestyle{empty} \oddsidemargin -1.0in \begin{document} \begin{equation*}{\bar {s}}=0.093\end{equation*}\end{document} and coefficient of variation = 0.204. Although our estimates of U and \documentclass[10pt]{article} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{pmc} \pagestyle{empty} \oddsidemargin -1.0in \begin{document} \begin{equation*}{\bar {s}}\end{equation*}\end{document} fall within the range of recent mutation rate and effect estimates in eukaryotes, the fraction of mutations with detectable effects on laboratory fitness (39%) appears to be far higher in φ6 than in eukaryotes

A fleet-metier based approach of the small scale fishing activity in the French West Indies

The development of the ecosystemic approach for fisheries supposes to improve integrated analysis of fisheries by considering the biological as well as the socio-economic dimensions of the exploitation. A prerequisite for integrated analysis is the improvement in the knowledge of fleets structure, fleet evolution and allocation of fishing effort in the different fisheries. However, small scale fisheries are often characterized by a lack of knowledge on the vessel fishing activity. This paper first presents a data collection methodology recently applied in the French West (Guadeloupe and Martinique) for the follow up of the whole vessel population. Based on a statistical analysis of these data sets, the paper develops a fleet-metier matrix giving the possibility to identify the structure of the fleet, the metier polyvalence of the vessels but also the origin of fishing mortality on the different exploited fishing resources. We then discuss the interest of this methodology for fisheries analysis and the perspective in terms of fisheries management at regional levels.Le développement de l’approche écosystémique des pêches suppose de renforcer les analyses couplant les dimensions biologiques et socio-économiques de l’exploitation. Cela passe en particulier par une meilleure connaissance des flottilles de pêche, de leur évolution et l’allocation de l’effort de pêche dans les différentes pêcheries. Dans un contexte de connaissance souvent très limitée sur l’activité de navires de petite pêche, ce papier présente la méthodologie de collecte de données utilisée, dans le cas des îles des Antilles françaises (Guadeloupe et Martinique). Sur la base d’une collecte de données minimale mais exhaustive de l’activité des navires, le papier propose le développement une analyse matricielle (flottilles-métiers) permettant de caractériser la structure des flottilles de pêche, d’identifier leur polyvalence en termes de métiers pratiqués et l’origine de la mortalité par pêche. On discute enfin l’intérêt de ce type d’approche pour l’analyse de pêcheries ainsi que les perspectives pour la gestion des pêches.El desarollo del estudio del ecosistema de las pescas supone que hay que intensificar los análisis considerando a la vez las dimensiones biológicas y socio-económicas de la explotación. Esto supone un mejor conocimiento de las flotillas de pesca, de su evolucíon y de la atribución del esfuerzo de pesca en las diferentes pesquerías. Sabiendo que los conocimientos sobre la actividad de los buques de pequeña pesca son muchas veces limitados, este documento presenta la metodología de recolección de informaciones estadísticas dada en el caso de las islas de las antillas francesas (Guadeloupe y Martinique). Basándose en una recoleccíon de informaciones estadísticas mínima pero eschaustiva de la actividad de los buques, este documento propone el desarollo de un análisis de las matrices (flotillas-metiers) que permite caracterizar la estructura de las flotillas de pesca y de identificar su caracter polivalente en términos de metiers practicados. No solo permite discutir sobre el impacto de las políticas que tienden a reorientar el esfuerzo de pesca de las especies de los bancos insulares hacia las especies pelágicas, sino también permite discutir sobre el interés de generalizar este tipo de recolección de informaciones estadísticas en los sistemas de observación de las pesquerías a escala de las pequeñas Antillas o de otros espacios pertinentes para la gestión de las pescas. Palabras llaves : flotillas, metiers, actividad de pesca, pequeña pesca, gestión de las pesca

Fuel consumption as a proxy for the assessment of nominal effort and variable costs: application to the French West Indies small-scale fleets

International audienceThe assessment of nominal effort is a key issue for the estimation of total catches. However, in many datacollection systems, total effort is inferred from sampling schemes at landing points or calculated from fishing forms or logbooks, which do not provide accurate information on a vessel's fishing activity. This problem is especially significant in small-scale fleets where fishers' behaviour and related fishing activity are heterogeneous. As fuel consumption by fishers is often subject to tax relief, it is registered by administration and can be used to improve and cross-check nominal effort measures (hours at sea, days at sea). This paper presents a methodology developed, using this type of dataset, for French West Indies fisheries. The protocol implemented was in three steps and used different data sources. First, a statistical analysis of engine power, engine type, and fuel consumption per métier was carried out based on field studies and fleet register information. Second, an algorithm was developed in order to estimate the number of trips and engine hours per vessel from vessel fuel consumption and vessel tank fill-ups, registered by the administration. Third, these estimates were used to provide a first assessment of the fleet landings per species and discuss the use of this information for calculation of revenue and running cost per trip, including fuel costs. Keywords: fuel consumption, nominal effort, engine power, catches estimates, running costs

Données statistiques de la pêche du marlin bleu aux Antilles Françaises (Guadeloupe et Martinique) : Proposition de reconstitution d’une série historique

Blue marlin is fished in the French Antilles around Fish Aggregating Devices (FADs). This fishery commenced in late 1985 and the fishing fleet reached its full potential in the second half of the 2000s. A fisheries information system (SIH), implemented from 2008, enables good estimation of catches and effort around FADs. The data on catch estimates of blue marlin and associated fishing effort are presented herein, as well as the methods used to assess them. From these and a survey of fishing masters, it is possible to reconstitute, year by year, the fishing fleet working around FADs in the French Antilles and to reconstitute a historical series of blue marlin landing.La pêche du marlin bleu se fait aux Antilles françaises autour des Dispositifs de Concentration de Poissons (DCP). Cette pêche a démarré à la fin des années 1985 et la flottille qui la pratique a atteint son plein développement dans la seconde moitié des années 2000. Un système d’Informations Halieutiques (SIH), mis en place à partir de 2008, permet d’avoir une bonne estimation des prises et de l’effort autour des DCP. Les données d’estimation des prises de marlin bleu et de l’effort de pêche associé sont présentées ici, ainsi que les méthodes utilisées pour les évaluer. A partir de ces données et d’une enquête auprès de patrons pêcheurs, il a été possible de reconstituer, année par année la flotte pêche travaillant autour des DCP aux Antilles françaises et de reconstituer une série historique de débarquement du marlin bleu