Paleoceanographic and climatic implications of a new Mediterranean Outflow branch in the southern Gulf of Cadiz

The presence of contourite drifts in the southern Gulf of Cadiz (GoC) along the Moroccan margin raises questions about the (re)circulation of Mediterranean Outflow Water (MOW) in the GoC and the origin of the currents depositing them. Here, we compare two cores representative of Iberian and Moroccan contourite drifts, covering the last 22 kyr. Although the whole sequence is contouritic in character, it reflects the interaction of distinctive silty-contourite facies (high flow velocity periods) imbedded in muddy-contourite facies (low flow velocity periods). Evidence from benthic foraminifera δ13C, sortable silt grain-size, oceanographic CTD profiles and numerical simulations, indicate the Mediterranean water mass as the source of the southern contourite deposits. Our data, therefore, suggests an additional branch of upper-MOW veering southwards off the Straits of Gibraltar along the Moroccan margin. During MIS-(Marine Isotope Stage) 2, upper-MOW was a sluggish current while in the Holocene upper-MOW dominated as a fast, semi-steady flow. Throughout the deglaciation, silty contourites associated with higher flow speeds were deposited in the northern and southern GoC during cold events such as Heinrich Stadial 1 (HS1) and the Younger Dryas, forced by global millennial-scale climate variability. Millennial variability also appears to drive the deposition of silty-contourites in the Holocene. We estimated an average duration of 1 ka for the process of depositing a fast contourite unit. The case of silty-contourite I6 (within HS1) allows us to illustrate with extremely high resolution a “rapid” sequential change in circulation, with gradual slow-down of dense Mediterranean water while surface was freshening (HS1), provoking injection of high-salinity intermediate waters (via contour-currents) into the GoC, and hence the North Atlantic. The subsequent brief collapse of dense water formation in the Mediterranean Sea triggered a major increase in sea surface temperatures (10 °C/ka) in the GoC, developing into the next interstadial (Bølling/Allerød). The impact of Mediterranean intermediate waters is manifested here by triggering a substantial rearrangement of intermediate and deep circulation in the North Atlantic, which would have further impacted the Atlantic Meridional Overturning Circulation (AMOC)

Rapid diagnosis of human brucellosis by SYBR Green I-based real-time PCR assay and melting curve analysis in serum samples

SUMMARYThe aim of this study was to develop a LightCycler-based real-time PCR (LC-PCR) assay and to evaluate its diagnostic use for the detection of Brucella DNA in serum samples. Following amplification of a 223-bp gene sequence encoding an immunogenetic membrane protein (BCSP31) specific for the Brucella genus, melting curve and DNA sequencing analysis was performed to verify the specificity of the PCR products. The intra- and inter-assay variation coefficients were 1.3% and 6.4%, respectively, and the detection limit was 5 fg of Brucella DNA (one genome equivalent). After optimisation of the PCR assay conditions, a standard curve was obtained with a linear range (correlation coefficient = 0.99) over seven orders of magnitude from 107 to 10 fg of Brucella DNA. The LC-PCR assay was found to be 91.9% sensitive and 95.4% specific when tested with 65 negative control samples and 62 serum samples from 60 consecutive patients with active brucellosis. The assay is reproducible, easily standardised, minimises the risk of infection in laboratory workers, and has a total processing time of < 2 h. It could therefore form a promising and practical approach for the rapid diagnosis of human brucellosis

Estudio fisiológico de Dinophysis spp. durante un ciclo de afloramiento/hundimiento en la Ría de Pontevedra

HABITFloraciones Algales Nocivas en Capas Fina

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

Changes in western Mediterranean thermohaline circulation in association with a deglacial Organic Rich Layer formation in the Alboran Sea

We thank the constructive comments of three anonymous reviewers that substantially improved this manuscript. JNPA has been funded by a Postdoctoral fellowship Beatriu de Pinós funded by the AGAUR from the Generalitat de Catalunya and the European Union through the Marie Curie-COFUND actions. LDP acknowledges support from the Ramón y Cajal program (MINECO, Spain), JF from the Serra Húnter Programme (Generalitat de Catalunya) and IC from the ICREA-Academia program from the Generalitat de Catalunya. We are indebted to Albert Català and Montse Guart (University of Barcelona), and Joaquim Perona and Regina Roca (CCiT-UB) for their support with the laboratory work.Supplementary data to this article can be found online at https://doi.org/10.1016/j.quascirev.2019.106075.The accumulation of an Organic Rich Layer (ORL) during the last deglaciation in the Alboran Sea (western Mediterranean Sea) and its link to changes in deep and intermediate water circulation are here investigated. Benthic foraminiferal assemblages and the shallow infaunal foraminifer Uvigerina peregrina δ13C record support the establishment of sustained high organic matter fluxes, and thus eutrophic conditions at the sea floor, during the late phase of the ORL (Younger Dryas to early Holocene periods). Since organic matter fluxes were lower (mesotrophic conditions) during the Bølling-Allerød period, they cannot be solely responsible for the ORL initiation. Geochemical, sedimentological and micropalaeontological proxies support a major weakening of the deep-water convection in the Gulf of Lion as the main driver for the development of poorly-ventilated conditions from intermediate depths (946 m) to the deep western Mediterranean basin that promoted the beginning of the ORL deposition. Nevertheless, a better ventilation at intermediate depths was established during the late ORL, while the deep basin remained poorly ventilated. We propose that our data reflect the arrival of a new better-ventilated intermediate water mass analogue to the current Levantine Intermediate Water (LIW) and/or a new intermediate water mass from the Gulf of Lion. The ultimate source of this water mass needs to be further explored but chronologies of the changes recorded here indicate that intermediate and deep ventilation phases were decoupled between the western and eastern Mediterranean basins during the deglaciation and early-middle Holocene.This work was funded by the projects TIMED (Call ref: ERC-CoG-2015; proposal number 683237) of the European Research Council (Consolidator Grants), CHIMERA (CTM2016-75411-R), CGL2015-66835-P and RTI2018-099489-B-I00 of the Ministerio de Economía y Competitividad of Spain. The Research Group GRC Geociències Marines (2017 SGR 315) of the Generalitat de Catalunya is also acknowledged, as well as the Research Groups RNM-178 and RNM-190 (Junta de Andalucía)

Distintos estadios del ciclo vital y el ciclo celular de Dinophysis caudata Saville-Kent y su relación con Dinophysis diegensis Kofoid.

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Phased cell division and other biological observations in field populations of Dinophysis spp during cell cycle studies

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Perfil de toxinas PSP de seis cepas de Gymnodinium catenatum de Galicia

En este trabajo se muestran los perfiles de toxinas PSP de diferentes cepas de Gymnodinium catenatum aisladas en aguas de la ría de Vigo, separadas y cuantificadas por CLAE, con reacción postcolumna y detección fluorimétrica. Las cepas se cultivaron en medio K modificado y se tomaron muestras del inóculo, una o dos tanto en la fase exponencial como en la estacionaria. De los resultados cabe deducir que los perfiles cualitativos son iguales en todas ellas, predominando las toxinas Cx ( C2, C4 y C 1) seguidas por GTX6, GTX5 y dcSTX; existiendo variaciones cuantitativas solamente.Publicad

Three‐dimensional geophysical characterization of the La Rambla and Zafra de Záncara anticlines (Loranca Basin, Central Spain)

The Zafra de Záncara anticline (also known as the El Hito anticline), located in the Loranca Cenozoic Basin (part of the Tagus Basin, Central Spain), had been studied by several oil companies during the late 1960s and early 1970s. In 2009, within the ‘Plan for selection and characterization of suitable structures of CO 2 geological storage’, this anticline was selected as a potential CO 2 storage site. A preliminary three-dimensional geological model, based on five geological cross sections that were constrained with the interpretation of the available seismic profiles (that are rather old and do not have very good quality), was created. With the aim of improving the geological knowledge of the Zafra de Záncara anticline and helping to investigate the suitability of a nearby anticline, namely La Rambla, as another structural closure that might make it a possible CO 2 storage site, a local gravity survey (1 station every km 2 ) was carried out in the area, seven new geological cross sections, based on these existing seismic profiles and field geology, were build, and a new three-dimensional geological model that included both anticlines, improved through three-dimensional stochastic gravity inversion, was constructed. The densities needed for the geological formations of the model come from the analysis of rock samples, logging data from El Hito-1 drillhole and petrophysical information from Instituto Geológico y Minero de España database. The inversion has improved the knowledge about the geometry of the anticlines’ traps and seals as well as the geometry of the basement relief and the structural relationship between basement and cover. © 2019 European Association of Geoscientists & EngineersThis study has been supported by the Instituto para la Reestructuración de la Minería del Carbón y el Desarrollo Alternativo de las Comarcas Mineras, Ministry of Energy and Industry, SpainPeer reviewe