Cross-validation of ELISA and a portable surface plasmon resonance instrument for IgG antibody serology with SARS-CoV-2 positive individuals.

We report on the development of surface plasmon resonance (SPR) sensors and matching ELISAs for the detection of nucleocapsid and spike antibodies specific to the novel coronavirus 2019 (SARS-CoV-2) in human serum, plasma and dried blood spots (DBS)

Apports des modeles mathematiques en epidemiologie: points de vue sur la filariose de Brancroft

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : TD 80520 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Quantifying food subsidies to the benthos due to discards. Task 4.4 Report on the quantification of discard flow to the seabed, relative to natural food sources.

Discards generated from marine fisheries have significantly affected species populations and community composition of seabirds through mechanisms such as competition, predator–prey interactions and nutrient transfer. Our understanding of the fate of discards beyond seabird scavenging is fragmented, but it is likely that similar mechanisms come into play. This study contributes in resolving this knowledge gap by quantifying the amount and composition of discards that become available to scavengers other than seabirds. The key was nevertheless found in revealing seabird discard consumption, as seabirds are likely the first in taking profit of fishery discards due to their high mobility. Their selective consumption determines the composition and amount of food remaining for others. The consumption of discards by scavenging seabirds was assessed for the French fishing fleet in the Bay of Biscay. Experimental sea trials were conducted to assess the proportion of discards consumed by foraging guild and discard type. Experimental discard consumption (EDC) was raised to fleet level by foraging guild using the total number of discards by discard type. The raising procedure accounted for the spatio-temporal variability of both foraging guilds and discards, by standardising both distributions to their lowest common resolution. Discards limited inferences in space, whilst the highest temporal resolution was determined by the biennial monitoring of foraging guilds. As EDC of roundfish by Large gulls and Gannets varied considerably, we investigated the main drivers. Consumption increased logarithmically with the number of ship followers for both guilds, but was greatly impaired by competitors for Large gulls. Competition between Large gulls and Gannets reduced the roundfish consumption by threefold, while other guilds such as Kittiwakes, Procellariids and Skuas had only a limited though significant influence. As Large gulls dominated during the first semester (April to September), the consumption of discards and notably roundfish was dictated by this foraging guild. The abundance of ship following Gannets was remarkably higher in the second semester (October to March). This change in flock composition and in numbers of ship followers implied an increase in the consumed proportion of roundfish of 27.9%. The total number of discards that became available to non-avian scavengers was however higher in the first semester, as more discards were produced during this period. Most discards comprised benthic invertebrates, but excluding this discard type revealed that over two thirds of the discards remained roundfish

Panorama des rejets réalisés par les différentes pêcheries françaises

L'exploitation de toutes les données disponibles (Obsmer, DCR, données réglementaires antérieures) devra permettre de distinguer les rejets générés par les différents métiers observés, ainsi que la part rejetée pour chaque espéce et par zone géographique. Sachant que les données du programme Obsmer collectées en 2009 ne pourront être extrapolées que lorsque les observations couvriront l'ensemble de l'année et que les statistiques de pêche de l'année seront complétes et disponibles, l'analyse demandée consiste en une comparaison entre les données échantillonnées entre 2003 et 2008, qui seront extrapolées dés lors que l'intensité d'échantillonnage des différents métiers sera jugée suffisante pour l'autoriser au plan statistique, avec celles de 2009

The meaning of fish size spectra, the effects of fishing on them and the usefulness of their slope as indicator of fishing impacts

A new time-dependent continuous model of biomass size spectra is developed. In this model, predation is the single process governing the energy flow in the ecosystem, as it causes both growth and mortality. Predation is size-dependent. The ratio of predator to prey is assumed to be distributed: predators may feed on a range of prey sizes. Under these assumptions, it is proven that linear size spectra are stationary solutions of the model. The slope of this size spectrum is insensitive to the magnitude of processes in the food web, such as the width of prey size distribution, the volume of water searched while foraging or the assimilation efficiency. Exploited fish communities are simulated by adding a size-dependent fishing mortality to the model: it is found that realistic fishing pressures should not affect the slope of size spectra, but their shape and stationarity