154 research outputs found

    Effect of dissolved organic matter (DOM) of contrasting origins in Cu and Pb speciation and toxicity to Paracentrotus lividus larvae

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    Original research paperWater samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolved organic matter(DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbanceand fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pbcomplexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOMon Cu and Pb bioavailability was studied by means of theParacentrotus lividusembryo-larval bioassay.Sediment elutriates and sewage-influenced water (1) were enriched 1.4–1.7 times in DOC; (2) absorbedand reemitted more light; and (3) presented higher Cu complexation capacities (LCu) than the naturalseawater used for their preparation.LCuvaried from 0.08 M in natural seawater to 0.3 and 0.5 Min sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cucomplexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC50of0.64 M, significantly higher than the Cu EC50of natural and artificial seawater, which was 0.38 M. Theprotecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with highintensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrationsin the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and causedlittle effect on Pb EC50. This effect was contrary for both elutriates: one elutriate reduced Pb toxicity incomparisonwiththecontrolartificialseawater,whiletheotherincreasedit.UVirradiationofthesamplescaused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOMparameterswererelatedtoCuspeciationandtoxicity:goodcorrelationswerefoundbetweenDOCandCuEC50, whileLCucorrelated better with the fluorescence of marine humic substances. The present resultsstress the importance of characterizing not only the amount but also the quality of seawater DOM tobetter predict ecological effects from total metal concentration dataSpanish Ministry of Education and Science (CTM2006-13880-C03-01/MAR), Xunta of Galicia (PGIDIT-05MA40201) and Basque Government (predoctoral grant)Versión del editor3,76

    Reconstructing Viral Genomes from the Environment Using Fosmid Clones: The Case of Haloviruses

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    Background: Metaviriomes, the viral genomes present in an environment, have been studied by direct sequencing of the viral DNA or by cloning in small insert libraries. The short reads generated by both approaches make it very difficult to assemble and annotate such flexible genomic entities. Many environmental viruses belong to unknown groups or prey on uncultured and little known cellular lineages, and hence might not be present in databases. Methodology and Principal Findings: Here we have used a different approach, the cloning of viral DNA into fosmids before sequencing, to obtain natural contigs that are close to the size of a viral genome. We have studied a relatively low diversity extreme environment: saturated NaCl brines, which simplifies the analysis and interpretation of the data. Forty-two different viral genomes were retrieved, and some of these were almost complete, and could be tentatively identified as head-tail phages (Caudovirales). Conclusions and Significance: We found a cluster of phage genomes that most likely infect Haloquadratum walsbyi, the square archaeon and major component of the community in these hypersaline habitats. The identity of the prey could be confirmed by the presence of CRISPR spacer sequences shared by the virus and one of the available strain genomes. Other viral clusters detected appeared to prey on the Nanohaloarchaea and on the bacterium Salinibacter ruber, covering most of the diversity of microbes found in this type of environment. This approach appears then as a viable alternative to describe metaviriomes in a much more detailed and reliable way than by the more common approaches based on direct sequencing. An example of transfer of a CRISPR cluster including repeats and spacers was accidentally found supporting the dynamic nature and frequent transfer of this peculiar prokaryotic mechanism of cell protection.This work was supported by projects MAGYK (BIO2008-02444), MICROGEN (Programa CONSOLIDERINGENIO 2010 CDS2009-00006), CGL2'09-12651-C02-01 from the Spanish Ministerio de Ciencia e Innovación, DIMEGEN (PROMETEO/2010/089) and ACOMP/2009/155 from the Generalitat Valenciana. FEDER funds supported this project. IG-H was supported by MAGYK from Ministerio de Ciencia e Innovación. A-BM-C was supported by CONSOLIDER-INGENIO 2010

    From community approaches to single-cell genomics: the discovery of ubiquitous hyperhalophilic Bacteroidetes generalists

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    The microbiota of multi-pond solar salterns around the world has been analyzed using a variety of culture-dependent and molecular techniques. However, studies addressing the dynamic nature of these systems are very scarce. Here we have characterized the temporal variation during 1 year of the microbiota of five ponds with increasing salinity (from 18% to >40%), by means of CARD-FISH and DGGE. Microbial community structure was statistically correlated with several environmental parameters, including ionic composition and meteorological factors, indicating that the microbial community was dynamic as specific phylotypes appeared only at certain times of the year. In addition to total salinity, microbial composition was strongly influenced by temperature and specific ionic composition. Remarkably, DGGE analyses unveiled the presence of most phylotypes previously detected in hypersaline systems using metagenomics and other molecular techniques, such as the very abundant Haloquadratum and Salinibacter representatives or the recently described low GC Actinobacteria and Nanohaloarchaeota. In addition, an uncultured group of Bacteroidetes was present along the whole range of salinity. Database searches indicated a previously unrecognized widespread distribution of this phylotype. Single-cell genome analysis of five members of this group suggested a set of metabolic characteristics that could provide competitive advantages in hypersaline environments, such as polymer degradation capabilities, the presence of retinal-binding light-activated proton pumps and arsenate reduction potential. In addition, the fairly high metagenomic fragment recruitment obtained for these single cells in both the intermediate and hypersaline ponds further confirm the DGGE data and point to the generalist lifestyle of this new Bacteroidetes group.This work was supported by the projects CGL2012-39627-C03-01 and 02 of the Spanish Ministry of Economy and Competitiveness, which were also co-financed with FEDER support from the European Union. TG group research is funded in part by a grant from the Spanish Ministry of Economy and Competitiveness (BIO2012-37161), a grant from the Qatar National Research Fund grant (NPRP 5-298-3-086) and a grant from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC (grant agreement no. ERC-2012-StG-310325)

    Counteracting gradients of light and soil nutrients in the understorey of Mediterranean oak forests.

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    The forest canopy modifies the availability of resources (light, water, and soil nutrients) in the understorey. In this paper we analyze the relationships between woody canopy density, litter accumulation, and topsoil N and P availability in the understorey of two oak forests: one in southern Portugal and the other in southern Spain. Both forests persist on low-nutrient soils, particularly poor in P. We hypothesize that direct and indirect effects of the canopy overstorey cause opposite gradients in the availability of essential resources (light and key soil nutrients) in the understorey. In both studied forests we found significant relationships between the overall canopy density, light availability, topsoil litter accumulation, and the availability of N and P, which frequently limit plant growth. Path analysis (by Shipley’s d-sep method) showed that the available data were consistent with the proposed causal model. The average values of soil variables at the end quartiles of the light-availability gradient were compared. Results showed large differences in litter accumulation (~30×) and available-N and -P topsoil concentrations (~3×) in the Spanish forest (with the wider environmental gradient). Furthermore, P increased from the ‘very low’ range to the ‘low’ or even the ‘optimum’ range of availability (according to standard plant growth criteria), which suggests potential effects on the growth of the understorey plant species. We conclude that the counteracting gradients of the essential resources -light and nutrients- in the forest understorey resulted from direct and indirect effects of the canopy overstorey, respectively. We suggest that these counteracting effects of the woody canopy on essential resources of different nature must be considered when interpreting the patterns of understorey plant populations and communities.The spanish MEC (CGL2005-05830-C03-01-BOS, DINAMED project) and the Portuguese FCT(SFRH/BD/8322/2002 grant to SMM)supported the research.Peer reviewe

    Preliminary study of the variations on the spatio-temporal distribution of a potentially exploitable species (Patagonotothen spp.) in the southwest Atlantic, using GIS techniques

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    The genus Patagonotothen is the most common Nototheniid on the Patagonian Shelf and slope and is part of the by-catch species in the bottom trawl fisheries. This paper presents preliminary results from the EC CRAFT project “Promoting higher added value to a finfish species rejected to sea”, aiming to develop the research and the technology necessary to promote higher added value to fishing activity by taking profit from a finfish species (Rockcod, Patagonotothen spp.) not known to consumers and currently discarded by the EU fishing fleet operating in the South West Atlantic in order to supply the EU seafood industry with a good quality raw material for human food manufacturing. Historical fishery data series (26 168 commercial hauls of which 12 745 were positive), including effort, catches and discards, as well as biological and environmental information, from 1988 onwards was used to describe and quantify patterns and spatio-temporal changes in the rockcod fishery. These data was collected by scientific observers on board commercial vessels.GIS analysis was carried out in order to study the seasonal geographical changes in the distribution of abundance, SST and densities calculated from CPUE. Fishery and environmental data as well as SST data derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR), were analysed in order to find monthly variations in spatial and depth distribution of Patagonotothen spp. Preliminary results demonstrated that, within areas of occurrence, there are significant correlations between fish abundance (CPUE), the oceanographic conditions of the area (SST gradients) and depth in certain months

    Clinical characteristics of patients hospitalized with COVID-19 in Spain: Results from the SEMI-COVID-19 Registry

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    Background: Spain has been one of the countries most affected by the COVID-19 pandemic. Objective: To create a registry of patients with COVID-19 hospitalized in Spain, in order to improve our knowledge of the clinical, diagnostic, therapeutic, and prognostic aspects of this disease. Methods: A multicentre retrospective cohort study, including consecutive patients hospitalized with confirmed COVID-19 throughout Spain. Epidemiological and clinical data, additional tests at admission and at seven days, treatments administered, and progress at 30 days of hospitalization were collected from electronic medical records. Results: Up to June 30th 2020, 15,111 patients from 150 hospitals were included. Their median age was 69.4 years (range: 18-102 years) and 57.2% were male. Prevalences of hypertension, dyslipidemia, and diabetes mellitus were 50.9%, 39.7%, and 19.4%, respectively. The most frequent symptoms were fever (84.2%) and cough (73.5%). High values of ferritin (73.5%), lactate dehydrogenase (73.9%), and D-dimer (63.8%), as well as lymphopenia (52.8%), were frequent. The most used antiviral drugs were hydroxychloroquine (85.6%) and lopinavir/ritonavir (61.4%); 33.1% developed respiratory distress. Overall mortality rate was 21.0%, with a marked increase with age (50-59 years: 4.7%, 60-69 years: 10.5%, 70-79 years: 26.9%, ≥ 80 years: 46.0%). Conclusions: The SEMI-COVID-19 Network provides data on the clinical characteristics of patients with COVID-19 hospitalized in Spain. Patients with COVID-19 hospitalized in Spain are mostly severe cases, as one in three patients developed respiratory distress and one in five patients died. These findings confirm a close relationship between advanced age and mortality.Antecedentes: España ha sido uno de los países más afectados por la pandemia de COVID-19.Objetivo: Crear un registro de pacientes hospitalizados en España por COVID-19 para mejorar nuestro conocimiento sobre los aspectos clínicos, diagnósticos, terapéuticos y pronósticos de esta enfermedad. Métodos: Estudio de cohorte retrospectiva, multicéntrico, que incluye pacientes consecutivos hospitalizados con COVID-19 confirmada en toda España. Se obtuvieron los datos epidemiológicos y clínicos, las pruebas complementarias al ingreso y a los 7 días de la admisión, los tratamientos administrados y la evolución a los 30 días de hospitalización de las historias clínicas electrónicas. Resultados: Hasta el 30 de junio de 2020 se incluyeron 15.111 pacientes de 150 hospitales. Su mediana de edad fue 69,4 años (rango: 18-102 años) y el 57,2% eran hombres. Las prevalencias de hipertensión, dislipemia y diabetes mellitus fueron 50,9%, 39,7% y 19,4%, respectivamente.Los síntomas más frecuentes fueron fiebre (84,2%) y tos (73,5%). Fueron frecuentes los valores elevados de ferritina (73,5%), lactato deshidrogenasa (73,9%) y dímero D (63,8%), así como lalinfopenia (52,8%). Los fármacos antivirales más utilizados fueron la hidroxicloroquina (85,6%)y el lopinavir/ritonavir (61,4%). El 33,1% desarrolló distrés respiratorio. La tasa de mortalidad global fue del 21,0%, con un marcado incremento con la edad (50-59 años: 4,7%; 60-69 años:10,5%; 70-79 años: 26,9%; ≥ 80 años: 46%).Conclusiones: El Registro SEMI-COVID-19 proporciona información sobre las características clínicas de los pacientes con COVID-19 hospitalizados en España. Los pacientes con COVID-19 hospitalizados en España son en su mayoría casos graves, ya que uno de cada 3 pacientes desarrolló distrés respiratorio y uno de cada 5 pacientes falleció. Nuestros datos confirman una estrecha relación entre la edad avanzada y la mortalidadLa Sociedad Española de Medicina Interna (SEMI) es la patrocinadora de este estudio

    Improvement in detecting cytomegalovirus drug resistance mutations in solid organ transplant recipients with suspected resistance using next generation sequencing

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    Objetives The aim of this study was to identify CMV drug resistance mutations (DRM) in solid organ transplant (SOT) recipients with suspected resistance comparing next-generation sequencing (NGS) with Sanger sequencing and assessing risk factors and the clinical impact of resistance. Methods Using Sanger sequencing as the reference method, we prospectively assessed the ability of NGS to detect CMV DRM in the UL97 and UL54 genes in a nationwide observational study from September 2013 to August 2016. Results Among 44 patients recruited, 14 DRM were detected by Sanger in 12 patients (27%) and 20 DRM were detected by NGS, in 16 (36%). NGS confirmed all the DRM detected by Sanger. The additional six mutations detected by NGS were present in <20% of the sequenced population, being located in the UL97 gene and conferring high-level resistance to ganciclovir. The presence of DRM by NGS was associated with lung transplantation (p = 0.050), the administration of prophylaxis (p = 0.039), a higher mean time between transplantation and suspicion of resistance (p = 0.038) and longer antiviral treatment duration before suspicion (p = 0.024). However, the latter was the only factor independently associated with the presence of DRM by NGS in the multivariate analysis (OR 2.24, 95% CI 1.03 to 4.87). Conclusions NGS showed a higher yield than Sanger sequencing for detecting CMV resistance mutations in SOT recipients. The presence of DRM detected by NGS was independently associated with longer antiviral treatment.Funding: M.A.M. was supported in part by: Agency for Health Technology Assessment and Research Supported by Ministerio de Economía y Competitividad, Instituto de Salud Carlos III (PS12/02131 and PI17/02150); Agència de Gestió d´Ajuts Universitaris I de Recerca, Generalitat de Catalunya, 2017 SGR 794; and Fundació Marató TV3 project code 201824

    Obscured Activity: AGN, Quasars, Starbursts and ULIGs observed by the Infrared Space Observatory

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    Some of the most active galaxies in the Universe are obscured by large quantities of dust and emit a substantial fraction of their bolometric luminosity in the infrared. Observations of these infrared luminous galaxies with the Infrared Space Observatory (ISO) have provided a relatively unabsorbed view to the sources fuelling this active emission. The improved sensitivity, spatial resolution and spectroscopic capability of ISO over its predecessor Infrared Astronomical Satellite (IRAS), has enabled significant advances in the understanding of the infrared properties of active galaxies. ISO surveyed a wide range of active galaxies which, in the context of this review, includes those powered by intense bursts of star-formation as well as those containing a dominant active galactic nucleus (AGN). Mid infrared imaging resolved for the first time the dust enshrouded nuclei in many nearby galaxies, while a new era in infrared spectroscopy was opened by probing a wealth of atomic, ionic and molecular lines as well as broad band features in the mid and far infrared. This was particularly useful since it resulted in the understanding of the power production, excitation and fuelling mechanisms in the nuclei of active galaxies including the intriguing but so far elusive ultraluminous infrared galaxies. Detailed studies of various classes of AGN and quasars greatly improved our understanding of the unification scenario. Far-infrared imaging and photometry also revealed the presence of a new very cold dust component in galaxies and furthered our knowledge of the far-infrared properties of faint starbursts, ULIGs and quasars. We summarise almost nine years of key results based upon ISO data spanning the full range of luminosity and type of active galaxies.Comment: Accepted for publication in 'ISO science legacy - a compact review of ISO major achievements', Space Science Reviews - dedicated ISO issue. To be published by Springer in 2005. 62 pages (low resolution figures version). Higher resolution PDFs available from http://users.physics.uoc.gr/~vassilis/papers/VermaA.pdf or http://www.iso.vilspa.esa.es/science/SSR/Verma.pd

    Where are you from, stranger? The enigmatic biogeography of North African pond turtles (Emys orbicularis) .

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    Abstract The European pond turtle (Emys orbicularis) is a Nearctic element in the African fauna and thought to have invaded North Africa from the Iberian Peninsula. All North African populations are currently identified with the subspecies E. o. occidentalis. However, a nearly range-wide sampling in North Africa used for analyses of mitochondrial and microsatellite DNA provides evidence that only Moroccan populations belong to this taxon, while eastern Algerian and Tunisian pond turtles represent an undescribed distinct subspecies. These two taxa are most closely related to E. o. galloitalica with a native distribution along the Mediterranean coast of northern Spain through southern France to western and southern Italy. This group is sister to a clade comprising several mitochondrial lineages and subspecies of E. orbicularis from Central and Eastern Europe plus Asia, and the successive sisters are E. o. hellenica and E. trinacris. Our results suggest that E. orbicularis has been present in North Africa longer than on the Iberian Peninsula and that after an initial invasion of North Africa by pond turtles from an unknown European source region, there was a phase of diversification in North Africa, followed by a later re-invasion of Europe by one of the African lineages. The differentiation of pond turtles in North Africa parallels a general phylogeographic paradigm in amphibians and reptiles, with deeply divergent lineages in the western and eastern Maghreb. Acknowledging their genetic similarity, we propose to synonymize the previously recognized Iberian subspecies E. o. fritzjuergenobsti with E. o. occidentalis sensu stricto. The seriously imperiled Moroccan populations of E. o. occidentalis represent two Management Units different in mitochondrial haplotypes and microsatellite markers. The conservation status of eastern Algerian pond turtles is unclear, while Tunisian populations are endangered. Considering that Algerian and Tunisian pond turtles represent an endemic taxon, their situation throughout the historical range should be surveyed to establish a basis for conservation measures

    Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund
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