Ostreopsis cf. ovata dynamics in the NW Mediterranean Sea in relation to biotic and abiotic factors.

An expansion of the distribution of Ostreopsis cf. ovata, a dinoflagellate which produces palytoxin-like compounds, has been reported in recent years. Economical and social interests are affected by blooms, as they are responsible for respiratory and skin problems in humans and may cause damage to marine organisms. In order to identify the most influential environmental factors that trigger proliferations of O. cf. ovata in the area of the adjacent shallow rocky coast of the Ebro Delta (NW Mediterranean Sea) a three-year survey was performed on the metaphytic microalgae community growing on the macrophytes Jania rubens and Corallina elongata. Small-size diatoms were more abundant than dinoflagellates; O. cf. ovata was identified as the only species present from the genus. Seawater temperature was the primary driver defining the ecological niche of O. cf. ovata. Freshwater and groundwater fluxes were more pronounced in southern than in northern sites, which may have resulted in a distinct O. cf. ovata spatial distribution, with the highest records of abundance and more frequent blooms in the north. In consequence, negative correlations between the abundance of O. cf. ovata and nitrate concentrations and significant positive correlation with salinity were observed. The temporal pattern of O. cf. ovata dynamics from mid-July to early-November is probably due to the fact that this species is observed only above a certain threshold temperature of seawater. Metaphytic cells of O. cf. ovata were smaller in the northern site than in the south, possibly as a result of an increase in cell division, coinciding with higher abundance, and this could be an indicator of favorable conditions. Toxicity in planktonic cells was negatively correlated with cell abundance in the water column, achieving maximum concentrations of 25pg. PLTX eqcell(-1).

Dataset on the RETRO-BMC cruise onboard the R/V Hespérides, April 2017, Brazil-Malvinas Confluence.

This dataset, gathered during the RETRO-BMC cruise, reports multiple-scale measurements at the Confluence of the Brazil and Malvinas Currents. The cruise was carried out between 8 and 28 April 2017 onboard R/V Hespérides, departing from Ushuaia and arriving to Santos. Along its track, the vessel recorded near-surface temperature and salinity, as well as the horizontal flow from 20 m down to about 800 m. A total of 33 hydrographic stations were completed in a region off the Patagonian Shelf, within 41.2°S-35.9°S and out to 53.0°W. At each station, a multiparametric probe and velocity sensors were deployed inside the frame of a rosette used to collect water samples at selected depths; these samples were later used for several water analyses, including inorganic nutrient concentrations. Microstructure measurements were carried out in 11 of these hydrographic stations. In addition, two high-resolution three-dimensional surveys were conducted with an instrumented undulating vehicle between 40.6°S-39.0°S and 55.6°W-53.8°W. Lastly, eight high-frequency vertical profilers were deployed in the region and five position-transmitting drifters were launched. These data allow the description of the Confluence from the regional scale to the microscale, and provide a view of the variability of the frontal region on time scales from days to weeks.

Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort.

Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2,445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionization-time of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD.

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.