Spring-neap tidal and circadian variability in the distribution of two groups of Pseudo-nitzschia species in an upwelling influenced estuary

High-resolution physical and biological measurements were carried out in the Ría de Pontevedra (NW Spain) in late spring during the ‘HABIT Pontevedra 2007’ survey, which utilized high vertical resolution instruments. Cell maxima of P. delicatissima (6 x 105 cells L-1) and P. seriata (2 x 106 cells L-1) groups were observed during the first half of the cruise during downwelling and a significant decrease in cell numbers occurred during subsequent upwelling conditions. The effect of tidal (both semidiurnal and spring-neap) and event driven (upwelling-downwelling cycle) variability were evident. The observed sequence of events suggests that Pseudo-nitzschia populations were advected from the shelf. The circadian variability was regulated by tidal forcing and Pseudo-nitzschia spp. maxima were observed at low tide. From results presented here we conclude that the magnitude of spring-neap tidal and circadian variability has to be considered when designing and implementing harmful algal bloom monitoring programmesEn prens

2017 Update of ESC/EAS Task Force on practical clinical guidance for proprotein convertase subtilisin/kexin type 9 inhibition in patients with atherosclerotic cardiovascular disease or in familial hypercholesterolaemia

A correction has been published: European Heart Journal, Volume 39, Issue 22, 7 June 2018, Pages 2105Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017.info:eu-repo/semantics/publishedVersio

Integrated understanding of initial conditions of early life stages using integrated ecosystem survey data

Since 2000, the yearly acoustic pelagic survey of Ifremer in the Bay of Biscay designed for fish stock assessment of small pelagic fish has been converted into an integrated pelagic ecosystem monitoring plateforme. This has been achieved by coupling sensors and automating data acquisition streams. The data series now spans from 2000 to 2014. Together with data sensors and sampling designs, we present here an integrated study allowing to understand the spawning process of anchovy. We compare the maps of anchovy eggs obtained with CUFES (continuous underway fish egg sampler) with that of their spawning adults sampled at the same time by acoustics and identification trawl hauls. The distributions of eggs are surprisingly different than that of adults, with in particular a shift in their gravity centres. The differences are characterized using geostatistics and interpreted with hydrological and meteorological information collected on board during the survey at stations. The initial conditions of early life stages are characterized

Développement d'un drone nautique pour le prélèvement d'échantillons d'eau en milieu côtier et estuarien (SPEEdoo)

A nautical drone was designed for the monitoring of estuarine and coastal waters in the context of the Water Framework Directive (WFD) to : - go up to 500 m off the coastline in less than 5 minutes, - perform in situ measurements (temperature, salinity, turbidity), - collect water samples for later analysis in the laboratory (phytoplankton identification, chlorophyll, nutrients, ...).Un drone nautique a été développé pour la surveillance des eaux côtières et estuariennes dans le cadre de la Directive Cadre sur l'Eau (DCE) pour : - aller du rivage à un point de prélèvement situé à 500 m en moins de 5 minutes, - effectuer des mesures in situ, - prélever des échantillons d'eau pour une analyse ultérieure au laboratoire (identification des espèces phytoplanctoniques, chlorophylle, nutriments,...)

Influence of physical forcing on mesozooplankton communities at the Ushant tidal front.

International audienceThe pelagic ecosystem around Ushant tidal front was studied over a spring-neap tidal cycle in September 2009. The system was divided in a mixed coastal zone, the frontal zone and a stratified oceanic zone, which remained stable from spring to neap tide. Standing stock, size structure and composition of the phytoplankton and mesozooplankton communities varied more intensely between zones than with the tidal cycle. Localized changes in chlorophyll a occurred due to forcing by wind and tides. At the front, a diatom bloom intensified from spring to neap tide, but generally phytoplankton communities maintained stable proportions and were numerically dominated by pico- and nanophytoplankton. Highest mesozooplankton diversity was encountered in the frontal zone where organisms from both sides are blended; yet highest biomass was found in the stratified zone 30 nm west of the front. Temporal changes in the abundance of several zooplankton groups occurred and mirror trophic dynamics, physical processes and phytoplankton production. Differences between normalized biomass spectra from LOPC and image analysis were strongest during spring tide. The spectral slope steepened from a theoretical equilibrium value in the stratified zone to <−1 in the mixed zone reflecting the greater importance of small sized mesozooplankton in coastal marine ecosystems

Biophysical Interactions Control the Size and Abundance of Large Phytoplankton Chains at the Ushant Tidal Front

International audiencePhytoplankton blooms are usually dominated by chain-forming diatom species that can alter food pathways from primary producers to predators by reducing the interactions between intermediate trophic levels. The food-web modifications are determined by the length of the chains; however, the estimation is biased because traditional sampling strategies damage the chains and, therefore, change the phytoplankton size structure. Sedimentological studies around oceanic fronts have shown high concentrations of giant diatom mats (.1 cm in length), suggesting that the size of diatom chains is underestimated in the pelagic realm. Here, we investigate the variability in size and abundance of phytoplankton chains at the Ushant tidal front (NW France) using the Video Fluorescence Analyzer (VFA), a novel and non-invasive system. CTD and Scanfish profiling characterized a strong temperature and chlorophyll front, separating mixed coastal waters from the oceanic-stratified domain. In order to elucidate spring-neap variations in the front, vertical microstructure profiler was used to estimate the turbulence and vertical nitrate flux. Key findings were: (1) the VFA system recorded large diatom chains up to 10.7 mm in length; (2) chains were mainly distributed in the frontal region, with maximum values above the pycnocline in coincidence with the maximum chlorophyll; (3) the diapycnal fluxes of nitrate enabled the maintenance of the bloom in the frontal area throughout the spring-neap tidal cycle; (4) from spring to neap tide the chains length was significantly reduced; (5) during neap tide, the less intense vertical diffusion of nutrients, as well as the lower turbulence around the chains, intensified nutrient-depleted conditions and, thus, very large chains became disadvantageous. To explain this pattern, we suggest that size plasticity is an important ecological trait driving phytoplankton species competition. Although this plasticity behavior is well known from experiments in the laboratory, it has never been reported from observations in the field

Optimisation de l’identification et du dénombrement du microphytoplancton avec le système couplé de numérisation et d’analyse d’images FlowCAM – Zoo/PhytoImage (système innovant). Action 9 – Livrable 3. Evolution du matériel de numérisation : prototype FastCAM et perspectives. Rapport final, février 2016

This deliverable contains all development work of the FastCAM, new tool for fast imaging of the phytoplankton, which took place in 2015. It consists of: One report of the FastCAM and its comparison with the FlowCAM presentation: The FlowCAM enables the digitalization of a sample of phytoplankton with X10 and X 4 magnifications. The first allows a better morphological description and therefore a higher taxonomic resolution but with a longer scan time (16 X). Thus, for routine analyses, only scanning at 4 X is possible. A considerable gain would be able to do an acquisition to the magnification 10 X with a time of analysis more short, comparable to 4 X. A fast flow imaging system has therefore developed in this sense. He was called FastCAM. The system is based on the use of a high resolution (2 Megapixels) and high‐speed camera allowing the acquisition to 340 FPS. In this way, it allows to scan 10 mL of sample with a X 10 magnification within 15 min. Comparison of the images with those obtained with the FlowCAM clearly shows a gain to the use of the FastCAM. The outlook now is the establishment of a set of learning for a coupling with Zoo/Phytoimage and the industrial transfer of the system. A slide show presentation of the system showed during a project meeting (on the 4th of November 2015).Ce livrable contient l’ensemble des travaux de développement du FastCAM, nouvel outil de numérisation rapide du phytoplancton, ayant eu lieu en 2015. Il est constitué de deux documents : Un rapport de présentation du FastCAM et de sa comparaison avec le FlowCAM. Le FlowCAM permet la numérisation d’un échantillon de phytoplancton avec des grandissements X10 et X4. Le premier permet une meilleure description morphologique et donc une meilleure résolution taxonomique mais avec un temps d'acquisition environ 16X plus long. Ainsi, pour des analyses en routine, seule une numérisation au X4 est possible. Un gain considérable serait de pouvoir réaliser une acquisition au grandissement 10X avec un temps d'analyse plus court, comparable au 4X. Un système d’imagerie rapide en flux a donc été développé en ce sens. Il a été nommé FastCAM. Le système repose sur l’utilisation d’une caméra rapide haute résolution (2 Megapixels) permettant l’acquisition à 340 images/s. Grâce à cela, il permet de numériser 10 mL d’échantillon avec un grandissement X10 en moins de 15 min. La comparaison des images à celles obtenues avec le FlowCAM en un temps équivalent au X4 montre clairement un gain à l’utilisation du FastCAM. Les perspectives maintenant sont la constitution d’un set d’apprentissage pour un couplage avec le logiciel Zoo/Phytoimage. Un diaporama de présentation du système, présenté lors d’une réunion de projet (4 novembre 2015

Anatomical predictors of successful prism adaptation in chronic visual neglect

International audienceVisual neglect is a frequent and disabling consequence of right hemisphere damage. Previous work demonstrated a probable role of posterior callosal dysfunction in the chronic persistence of neglect signs. Prism adaptation is a non-invasive and convenient technique to rehabilitate chronic visual neglect, but it is not effective in all patients. Here we aimed to assess the hypothesis that prism adaptation improves left neglect by facilitating compensation through the contribution of the left, undamaged hemisphere. We assessed the relationship between prism adaptation effects, cortical thickness and white matter integrity in a group of 14 patients with unilateral right-hemisphere strokes and chronic visual neglect. Results showed that patients who benefitted from prism adaptation had thicker cortex in temporo-parietal, prefrontal and cingulate areas of the left, undamaged hemisphere. Additionally, these patients had a higher fractional anisotropy value in the body and genu of the corpus callosum. Results from normal controls show that these callosal regions connect temporo-parietal, sensorimotor and prefrontal areas. Finally, shorter time intervals from the stroke tended to improve patients' response to prism adaptation. We concluded that prism adaptation may improve left visual neglect by promoting the contribution of the left hemisphere to neglect compensation. These results support current hypotheses on the role of the healthy hemisphere in the compensation for stroke-induced, chronic neuropsychological deficits, and suggest that prism adaptation can foster this role by exploiting sensorimotor/prefrontal circuits, especially when applied at early stages post-stroke

Development of a Deep Chlorophyll Maximum of Heterocapsa Triquetra Ehrenb. at the Entrance to the Gulf of Finland.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Dual-frequency ADCPs measuring turbidity

A pair of self-contained acoustic Doppler current profilers (SC-ADCPs) operating with different frequencies were moored on a muddy sea bottom at about 20 m depth in the Bay of Vilaine off the French Atlantic coast. With their acoustic beams oriented upwards, the SC-ADCPs ensonified most of the water column. The results of several months of in situ recorded echo intensity data spanning 2 years (2003 to 2004) from the dual-frequency ADCPs are presented in this paper. The aim was to estimate suspended particle mass concentration and mean size. A concentration index CI is proposed for the estimation of particle concentration. Based on theory the CI-unlike the volume backscatter strength-does not depend on particle size. Compared with in situ optical data, the CI shows reasonable precision but not increased with respect to that of the highest-frequency backscatter strength. Concerning the mean particle size, despite a lack of quantitative validation with optical particle-size measurements, the method yielded a qualitative discrimination of mineral (small) and organic (large) particles. This supports the potential of dual-frequency ADCPs to quantitatively determine particle size. A cross-calibration of the transducers of each ADCP shows that a specific component of the precision of the backscatter strength measured by ADCP depends on the acoustic frequency, the cell thickness and the ensemble integration time. Based on these results, the use of two ADCPs operating with distinctly different frequencies (two octaves apart) or a single dual-frequency ADCP is recommended