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The El Niño Southern Oscillation (ENSO) drives important changes in the marine productivity of the Equatorial Pacific, in particular during major El Niño/La Niña transitions. Changes in environmental conditions associated with these climatic events also likely impact phytoplankton composition. In this work, the distribution of four major phytoplankton groups (nanoeucaryotes, Prochlorococcus, Synechococcus, and diatoms) was examined between 1996 and 2007 by applying the PHYSAT algorithm to the ocean color data archive from the Ocean Color and Temperature Sensor (OCTS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Coincident with the decrease in chlorophyll concentrations, a large-scale shift in the phytoplankton composition of the Equatorial Pacific, that was characterized by a decrease in Synechococcus and an increase in nanoeucaryote dominance, was observed during the early stages of both the strong El Niño of 1997 and the moderate El Niño of 2006. A significant increase in diatoms dominance was observed in the Equatorial Pacific during the 1998 La Niña and was associated with elevated marine productivity. An analysis of the environmental variables using a coupled physical-biogeochemical model (NEMO-PISCES) suggests that the Synechococcus dominance decrease during the two El Niño events was associated with an abrupt decline in nutrient availability (−0.9 to −2.5 μM NO3 month−1). Alternatively, increased nutrient availability (3 μM NO3 month−1) during the 1998 La Niña resulted in Equatorial Pacific dominance diatom increase. Despite these phytoplankton community shifts, the mean composition is restored after a few months, which suggests resilience in community structure.

Item does not contain fulltext, Cardiovascular disease (CVD) due to atherosclerosis of the arterial vessel wall and to thrombosis is the foremost cause of premature mortality and of disability-adjusted life years (DALYs) in Europe, and is also increasingly common in developing countries.1 In the European Union, the economic cost of CVD represents annually E192 billion1 in direct and indirect healthcare costs. The main clinical entities are coronary artery disease (CAD), ischaemic stroke, and peripheral arterial disease (PAD). The causes of these CVDs are multifactorial. Some of these factors relate to lifestyles, such as tobacco smoking, lack of physical activity, and dietary habits, and are thus modifiable. Other risk factors are also modifiable, such as elevated blood pressure, type 2 diabetes, and dyslipidaemias, or non-modifiable, such as age and male gender. These guidelines deal with the management of dyslipidaemias as an essential and integral part of CVD prevention. Prevention and treatment of dyslipidaemias should always be considered within the broader framework of CVD prevention, which is addressed in guidelines of the Joint European Societies' Task forces on CVD prevention in clinical practice.2 - 5 The latest version of these guidelines was published in 20075; an update will become available in 2012. These Joint ESC/European Atherosclerosis Society (EAS) guidelines on the management of dyslipidaemias are complementary to the guidelines on CVD prevention in clinical practice and address not only physicians [e.g. general practitioners (GPs) and cardiologists] interested in CVD prevention, but also specialists from lipid clinics or metabolic units who are dealing with dyslipidaemias that are more difficult to classify and treat.

nr 570 -General Poster Session, info:eu-repo/semantics/published

nr 570 -General Poster Session, info:eu-repo/semantics/published

info:eu-repo/semantics/nonPublished

The El Niño Southern Oscillation (ENSO) drives important changes in marine productivity of the Equatorial Pacific, in particular during major El Niño/La Niña transitions. Changes in environmental conditions associated with these climatic events also likely impact the phytoplankton composition. In this work, the distribution of four major phytoplankton groups (nanoeucaryotes, Prochlorococcus, Synechococcus and diatoms) was monitored between 1996 and 2007 by applying the PHYSAT algorithm to the ocean color data archive from the Ocean Color and Temperature Sensor (OCTS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Coincident with the decrease in chlorophyll concentrations, a large-scale change in the Equatorial Pacific phytoplankton composition that was characterized by a decrease in Synechococcus and an increase in nanoeucaryotes, was observed during the early stages of both the strong El Niño of 1997 and the moderate El Niño of 2006. A significant increase in diatoms in the Equatorial Pacific was observed during the 1998 La Niña and is associated with elevated marine productivity. An analysis of the environmental variables using a coupled physical-biogeochemical model (NEMO-PISCES) suggests that the decrease in Synechococcus during the two El Niño events was associated with an abrupt decrease in nutrient availability (-0.9 to -2.5 μM NO3 month-1), while an increase in nutrient availability (3 μM NO3 month-1) during the 1998 La Niña led to the development of diatom blooms in the Equatorial Pacific.Our results show a rapid resilience of these changes of the structure of phytoplankton communities which come back to a mean composition after a few months. Such rapid modifications of the composition of phytoplankton groups have thus to be considered in future modeling approaches to represent variability of the marine productivity in the Equatorial Pacific and to quantify its potential implications on food-web and on global carbon cycle.

Dimethylsulfoniopropionate (DMSP) is produced in surface seawater by phytoplankton. Phytoplankton culture experiments have shown that nanoeucaryotes (NANO) display much higher mean DMSP-to-Carbon or DMSP-to-Chlorophyll (Chl) ratios than Prochlorococcus (PRO), Synechococcus (SYN) or diatoms (DIAT). Moreover, the DMSP-lyase activity of algae which cleaves DMSP into dimethylsulfide (DMS) is even more group specific than DMSP itself. Ship-based observations have shown at limited spatial scales, that sea surface DMS-to-Chl ratios (DMS: Chl) are dependent on the composition of phytoplankton groups. Here we use satellite remote sensing of Chl (from SeaWiFS) and of Phytoplankton Group Dominance (PGD from PHYSAT) with ship-based sea surface DMS concentrations (8 cruises in total) to assess this dependence on an unprecedented spatial scale. PHYSAT provides PGD (either NANO, PRO, SYN, DIAT, Phaeocystis (PHAEO) or coccolithophores (COC)) in each satellite pixel (1/4 degrees horizontal resolution). While there are identification errors in the PHYSAT method, it is important to note that these errors are lowest for NANO PGD which we typify by high DMSP: Chl. In summer, in the Indian sector of the Southern Ocean, we find that mean DMS: Chl associated with NANO + PHAEO and PRO + SYN + DIAT are 13.6 +/- 8.4 mmol g(-1) (n = 34) and 7.3 +/- 4.8 mmol g(-1) (n = 24), respectively. That is a statistically significant difference (P < 0.001) that is consistent with NANO and PHAEO being relatively high DMSP producers. However, in the western North Atlantic between 40 degrees N and 60 degrees N, we find no significant difference between the same PGD. This is most likely because coccolithophores account for the non-dominant part of the summer phytoplankton assemblages. Meridional distributions at 22 degrees W in the Atlantic, and 95 degrees W and 110 degrees W in the Pacific, both show a marked drop in DMS: Chl near the equator, down to few mmol g(-1), yet the basins exhibit different PGD (NAN

We have combined the first satellite maps of the global distribution of phytoplankton functional type and new measurements of phytoplankton-specific isoprene productivities, with available remote marine isoprene observations and a global model, to evaluate our understanding of the marine isoprene source and its impacts on organic aerosol abundances. Using satellite products to scale up data on phytoplankton-specific isoprene productivity to the global oceans, we infer a mean "bottom-up" oceanic isoprene emission of 0.31 +/- 0.08 (1 sigma) Tg/yr. By minimising the mean bias between the model and isoprene observations in the marine atmosphere remote from the continents, we produce a "top-down" oceanic isoprene source estimate of 1.9 Tg/yr. We suggest our reliance on limited atmospheric isoprene data, difficulties in simulating in-situ isoprene production rates in laboratory phytoplankton cultures, and limited knowledge of isoprene production mechanisms across the broad range of phytoplankton communities in the oceans under different environmental conditions as contributors to this difference between the two estimates. Inclusion of secondary organic aerosol (SOA) production from oceanic isoprene in the model with a 2% yield produces small contributions (0.01-1.4%) to observed organic carbon (OC) aerosol mass at three remote marine sites in the Northern and Southern Hemispheres. Based on these findings we suggest an insignificant role for isoprene in modulating remote marine aerosol abundances, giving further support to a recently postulated primary OC source in the remote marine atmosphere.

Recently, reanalysis of long-term ocean color data (CZCS and SeaWiFS; Antoine et al., 2005) has shown that world ocean average phytoplankton chlorophyll levels show an increase of 20% over the last two decades. It is however unknown whether this increase is associated with a change in the distribution of phytoplankton groups or if it simply corresponds to an increase of the productivity. Within the framework of the GLOBPHY project, the distribution of the phytoplankton groups was monitored by applying the PHYSAT method (Alvain et al., 2005) to the historical ocean color data series from CZCS, OCTS and SeaWiFS sensors. The PHYSAT algorithm allows identification of several phytoplankton, like nanoeucaryotes, prochlorococcus, synechococcus and diatoms. Because both sensors (OCTS-SeaWiFS) are very similar, OCTS data were processed with the standard PHYSAT algorithm to cover the 1996-1997 period during which a large El Niño event occurred, just before the SeaWiFS era. Our analysis of this dataset (1996-2006) evidences a strong variability in the distribution of phytoplankton groups at both regional and global scales. In the equatorial region (0°-5°S), a three-fold increase of nanoeucaryotes frequency was detected in opposition to a two-fold decrease of synechococcus during the early stages of El Niño conditions (May-June 1997, OCTS). The impact of this El Niño is however not confined to the Equatorial Pacific and has affected the global ocean.The processing of CZCS data with PHYSAT has required several adaptations of this algorithm due to the lower performances and the reduced number of spectral bands of the sensor. Despites higher uncertainties, the phytoplankton groups distribution obtained with CZCS is globally consistent with that of SeaWiFS. A comparison of variability in global phytoplankton distribution between 1979-1982 (CZCS) and 1999-2002 (SeaWiFS) suggests an increase in nanoeucaryotes at high latitudes (>40°) and in the equatorial region (10°S-10°N ) for proc

We have examined differences in regional and seasonal variability among seven global climatologies of sea-surface dimethyl sulfide (DMS) concentrations. We found large differences between recent climatologies and that typically used by most atmospheric sulfur models. The relative uncertainty (1σ/mean) in the latitudinal distribution of the annual mean DMS concentration increases from about 50% in tropical and temperate regions to nearly 100% in the high latitudes. We also compared these climatologies to new measurements in the North Atlantic Ocean taken during the 2001 Programme Océan Multidisciplinaire Méso Echelle (POMME) expeditions.