Trajectories of humoral and cellular immunity and responses to a third dose of mRNA vaccines against SARS-CoV-2 in patients with a history of anti-CD20 therapy.

BACKGROUND The majority of patients with B-cell-depleting therapies show compromised vaccination-induced immune responses. Herein, we report on the trajectories of anti-SARS-CoV-2 immune responses in patients of the RituxiVac study compared with healthy volunteers and investigate the immunogenicity of a third vaccination in previously humoral non-responding patients. METHODS We investigated the humoral and cell-mediated immune response after SARS-CoV-2 messanger RNA vaccination in patients with a history with anti-CD20 therapies. Coprimary outcomes were antispike and SARS-CoV-2-stimulated interferon-γ concentrations in vaccine responders 4.3 months (median; IQR: 3.6-4.8 months) after first evaluation, and humoral and cell-mediated immunity (CMI) after a third vaccine dose in previous humoral non-responders. Immunity decay rates were compared using analysis of covariance in linear regression. RESULTS 5.6 months (IQR: 5.1-6.7) after the second vaccination, we detected antispike IgG in 88% (29/33) and CMI in 44% (14/32) of patients with a humoral response after two-dose vaccination compared with 92% (24/26) healthy volunteers with antispike IgG and 69% (11/16) with CMI 6.8 months after the second vaccination (IQR: 6.0-7.1). Decay rates of antibody concentrations were comparable between patients and controls (p=0.70). In two-dose non-responders, a third SARS-CoV-2 vaccine elicited humoral responses in 19% (6/32) and CMI in 32% (10/31) participants. CONCLUSION This study reveals comparable immunity decay rates between patients with anti-CD20 treatments and healthy volunteers, but inefficient humoral or CMI after a third SARS-CoV-2 vaccine in most two-dose humoral non-responders calling for individually tailored vaccination strategies in this population.Trial registration numberNCT04877496; ClinicalTrials.gov number

Etude de la capacite trophique du bassin de Marennes-Oleron : application d'un modele couple de transport particulaire et de croissance de l'huitre Crassostrea gigas

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Etude de la capacité trophique du bassin de Marennes-Oléron: Utilisation d'un modèle couplé de transport particulaire et de croissance de l'huître Crassostra gigas

The interrelationship between the amount of oysters Crassostrea gigas and their scope for growth in the Bay of Marennes-Oleron is studied through a mathematical model. lndividual growth results from the difference between assimilation and respiration , which are related to weight, temperature, seston and available food in the water height. The water height is supposed to be well mixed vertically and biodeposition instantaneously recycled. Besides, an advection-dispersion model allows to predict the food and mineral transport. lt is based on a box structure applied to the oyster production area. The parameters are evaluated from eulerian currents averaged over the tide, tidal excursion and distance between box centers. The more important competitors are taken into account a s driving functions. The impact of the stock variability on growth is studied by sensitivity analysis, which points out a major influence on growth in the south of the Bay. As a consequence of the lack of prediction of the model, the temporal and spatial variability of the Bay is studied. The introduction of a sedimentary compartment is discussed as weIl as the coupling with a primary production model .L'interaction entre le stock d'huîtres cultivées Crassostrea gigas et leurs performances de croissance dans le bassin de Marennes- Oléron est étudiée à l'aide d'un modèle mathématique. La croissance individuelle représente le bilan entre l'assimilation et la respiration, fonctions du poids individuel, de la température, du seston total et de l'énergie particulaire assimilable dans la colonne d'eau. La production primaire n 'est pas simulée, la colonne d'eau est supposée homogène sur la verticale et les biodèpots sont intègralement recyclés. Une structure en boites a été appliquée à la zone de production ostréicole afin de calculer le transport particulaire. Les équations font intervenir les flux de courant résiduels eulériens, les différences de concentrations entre boîtes adjacentes et l'excursion de marée . Les compétiteurs les plus importants sont introduits en variables forçantes. Les effets marginaux de la répartition des stocks sur les performances de croissance sont étudiés à l'aide d'une étude de sensibilité, qui montre un impact majeur pour les croissances au sud du bassin. L' analyse des défauts du modèle incite à étudier les sources de variabilité temporelle et spatiale du milieu. L'introduction d'un compartiment sédimentaire et le couplage d'un modèle de production primaire sont également envisagés

Ecological carrying capacity in shellfish culture Operational models of carrying capacity applied to a Norwegian fjord

Estimation of production carrying capacity for shellfish culture has become a major focus in research, with operational models applied at culture sites worldwide. Fundamental to these efforts are an understanding of the relationship between nutrients, primary production, and shellfish bioenergetics. The potential for manipulation of nutrients via artificial upwelling has been undertaken in a Norwegian fjord in the CANO Project. Research in this area includes several types of models at varying spatial scales. One of the more useful configurations has been a box model allowing variation in the location of the upweller as well as the sites of mussel culture. In a companion conference paper in by Filgueira and Grant, optimization routines are used to maximize mussel production in the upper fjord based on projected nutrientphytoplankton enhancement by the upweller. The present paper considers the initial stages of a fully spatial companion model where the results can be mapped in detail

Legislative Documents

Also, variously referred to as: Senate bills; Senate documents; Senate legislative documents; legislative documents; and General Court documents

Probabilistic approach of water residence time and connectivity using Markov Chains with application to tidal embayments

Markov Chain analysis was recently proposed to assess the time scales and preferential pathways into biological or physical networks by computing residence time, first passage time, rates of transfer between nodes and number of passages in a node. We propose to adapt an algorithm already published for simple systems to physical systems described with a high resolution hydrodynamic model. The method is applied to bays and estuaries on the Eastern Coast of Canada for their interest in shellfish aquaculture. Current velocities have been computed by using a 2 dimensional grid of elements and circulation patterns were summarized by averaging Eulerian flows between adjacent elements. Flows and volumes allow computing probabilities of transition between elements and to assess the average time needed by virtual particles to move from one element to another, the rate of transfer between two elements, and the average residence time of each system. We also combined transfer rates and times to assess the main pathways of virtual particles released in farmed areas and the potential influence of farmed areas on other areas. We suggest that Markov chain is complementary to other sets of ecological indicators proposed to analyse the interactions between farmed areas - e.g. depletion index, carrying capacity assessment. Markov Chain has several advantages with respect to the estimation of connectivity between pair of sites. It makes possible to estimate transfer rates and times at once in a very quick and efficient way, without the need to perform long term simulations of particle or tracer concentration

Global and local factors driving the phenology of Alexandrium minutum (Halim) blooms and its toxicity

The dinoflagellate Alexandrium minutum is a toxic bloom-forming species distributed worldwide. The mechanisms driving and promoting the species blooms and their toxicity are studied and presented here. Most previously published work focuses on local and/or short-term scales. In this study, a broad temporal and spatial approach is addressed using time series covering several sites over several years and combining environmental variables and A. minutum abundances from the French English Channel − Atlantic coasts. Data were explored by means of phenology and threshold analysis. The A. minutum bloom characteristics are defined. Only one bloom per year is measured and it may reach more than a million of cells L−1. Bloom period extends from April to October and the bloom length ranges from two weeks to six months. In the ecosystems studied, water temperature and river flow, as regional and local factors respectively, are the main environmental drivers influencing the magnitude, growth rate and length of the blooms. Bloom toxicity is linked to the bloom maximum abundance and river flow. This work provides new knowledge for further managing tools for A. minutum blooms in the ecosystems studied

Modelisation of oyster shell growth at 3 stations in the Patuxent river (Chesapeake Bay)

In oyster production area the determination of the stock, estimation of mortality and growth rates are determinant for knowledge of the fishery. Growth models can be used to predict the time to reach marketable size (76 mm in Chesapeake Bay). They are also important in term of management, when they can predict the future value of the stock (Askew, 1978). Oyster growth models can be built by analysing growth of natural oysters but absolute age is orten unknown. Many authors report growth data in Chesapeake Bay for suspended oyster culture. Unfortunalely, modelisation of the growth was not developed. In that study oyster, shell growth models have been established at three stations in the Patuxent river. Seasonal eITects on growth were integrated in the mode

Ecosystem modelling to assess the impact of rearing density, environment variability and mortality on oyster production

The natural productivity of ecosystems, farming practices and mortality events drive the rearing density and growth of oysters in shellfish farming areas. The variability of these drivers, which can be of natural or anthropic origin, is therefore an important source of variation in the growth performance and production of shellfish. Knowledge of these variabilities and their relative importance help producers to anticipate their effects and adapt aquaculture practices in order to limit negative impacts and guarantee a constant, or at least acceptable, level of production. In this paper, we implement a 3D model coupling hydrodynamics, primary production and individual growth to predict oyster growth and production in Bourgneuf Bay (French Atlantic coast). We set up numerous scenarios to compare and hierarchize the impacts of aquaculture practices, environmental variability and mortality events on shellfish production. Our results allowed us to propose a simplified management tool, in the form of response functions, to optimize shellfish farming practices interannually. This tool will help shellfish farmers quickly recover production levels in response to variations in mortality and/or environmental conditions