52 research outputs found

    Diatoms as a paleoproductivity proxy in the NW Iberian coastal upwelling system (NE Atlantic)

    Get PDF
    The objective of the current work is to improve our understanding of how water column diatom's abundance and assemblage composition is seasonally transferred from the photic zone to seafloor sediments. To address this, we used a dataset derived from water column, sediment trap and surface sediment samples recovered in the NW Iberian coastal upwelling system. Diatom fluxes (2.2 (+/- 5.6) 10(6) valves m(-2) d(-1)) represented the majority of the siliceous microorganisms sinking out from the photic zone during all studied years and showed seasonal variability. Contrasting results between water column and sediment trap diatom abundances were found during downwelling periods, as shown by the unexpectedly high diatom export signals when diatom- derived primary production achieved their minimum levels. They were principally related to surface sediment remobilization and intense Minho and Douro river discharge that constitute an additional source of particulate matter to the inner continental shelf. In fact, contributions of allochthonous particles to the sinking material were confirmed by the significant increase of both benthic and freshwater diatoms in the sediment trap assemblage. In contrast, we found that most of the living diatom species blooming during highly productive upwelling periods were dissolved during sinking, and only those resistant to dissolution and the Chaetoceros and Leptocylindrus spp. resting spores were susceptible to being exported and buried. Fur-thermore, Chaetoceros spp. dominate during spring-early summer, when persistent northerly winds lead to the upwelling of nutrient-rich waters on the shelf, while Leptocylindrus spp. appear associated with late-summer upwelling relaxation, characterized by water column stratification and nutrient depletion. These findings evidence that the contributions of these diatom genera to the sediment's total marine diatom assemblage should allow for the reconstruction of different past upwelling regimes.CAIBEX [CTM2007-66408-C02-01/MAR]; REIMAGE [CTM2011-30155-C03-03]; Spanish Government, EXCAPA project [10MDS402013PR]; Xunta de Galicia; EU FEDER [INTERREG 2009/2011-0313/RAIA/E]; RAIA. co [INTERREG2011/2013-052/RAIA.co/1E]; CALIBERIA project [PTDC/MAR/102045/2008]; Fundacao para a Ciencia e a Tecnologia (FCT-Portugal) [COMPETE/FEDER-FCOMP01-0124-FEDER-010599]; Xunta de Galicia (Spain) [SFRH/BPD/111433/2015]; FCT (Portugal) [SFRH/BPD/111433/2015]; [SFRH/BD/88439/2012

    Cambios temporales en los transportes y la distribución de las masas de agua a lo largo de la sección 20º W de CAIBOX (Atlántico NE)

    Get PDF
    24 páginas, 3 tablas, 7 figuras[EN] The CAIBOX cruise was conducted from 25 July to 14 August 2009. Three consecutive transects (zonal, meridional, and transverse) formed a closed box to the west of the Strait of Gibraltar. This study aimed to analyze the thermohaline properties, volume transports, and water mass distributions (percentages) along the meridional section (30–41.5º N, 20º W). We identified the main geostrophic current (Azores Current) and its associated volume transport and interannual changes. Data from previous cruises (AZORES I, A16N, CLIVAR, OACES, and CHAOS) with similar tracks were employed to compare with the CAIBOX meridional section. All but one (CHAOS) were summer cruises. We estimated a mean transport for the Azores Current at 20º W of 9.3 ± 2.6 Sv. There appears to be an inverse relation between the position of this current and its associated transport, with relatively high (low) transports when the current is located roughly south (north) of 35º N. Regarding water masses, an increase of 14.4% was found for Mediterranean Water compared with the 1993, 1998, and 2003 cruises; however, Labrador Sea Water decreased its contribution and southward spreading between 1998 and 2009[ES] Entre el 25 de julio y el 14 de agosto de 2009 se llevó a cabo la campaña CAIBOX, que constó de tres transectos consecutivos (zonal, occidental y transversal) conformando una caja cerrada al oeste del estrecho de Gibraltar. El objetivo principal del presente trabajo fue el estudio de las propiedades termohalinas, los transportes (en términos de volumen) y la distribución de las masas de agua (en porcentajes) a lo largo de la sección occidental (30–41.5º N, 20º W). Se identificó la corriente geostrófica principal (Corriente de las Azores), el transporte asociado a ella y sus cambios interanuales. Adicionalmente se consideraron los datos de cinco campañas anteriores (AZORES I, A16N, CLIVAR, OACES y CHAOS) con secciones similares a las de la campaña CAIBOX. Todas excepto una (CHAOS) fueron campañas estivales. El transporte medio para la Corriente de las Azores a 20º W se estimó en 9.3 ± 2.6 Sv. Parece existir cierta relación inversa entre la posición de dicha corriente y su transporte asociado, con transportes relativamente altos (bajos) cuando la corriente se sitúa al sur (norte) de 35º N. En cuanto a las masas de agua, se observa un incremento de 14.4% del Agua Mediterránea en comparación con las campañas de 1993, 1998 y 2003; sin embargo, el Agua de Labrador ha disminuido su contribución y su propagación hacia el sur entre 1998 y 2009.An important part of the data presented in this paper was obtained through the CAIBEX project: Shelf-ocean Exchanges in the Canaries-Iberia Large Marine Ecosystem (CTM2007-66408-C02/MAR), supported by the Spanish Ministry of Education and Science. The first author, LIC, was funded by a FPU predoctoral fellowship from the National Human Resources Formation Program, within the framework of the 2008–2011 National Scientific Research, Development and Technological Innovation Plan of the Spanish Ministry of Education. The fourth author, NVR, was supported by the Isabel Barreto Program (IN840E) from the Xunta de Galicia.Peer reviewe

    Contaminación del aire a filo de calle en Quito, caso estudio Guayaquil y Espejo.

    Get PDF
    Se estudió la contaminación del aire a filo de calle en el Centro Histórico de Quito (DMQ) en un punto de alto flujo vehicular mediante el monitoreo continuo de gases y material particulado entre el 5 y 12 de abril de 2018. Se obtuvieron los perfiles horarios de las concentraciones de contaminantes y se pudo explicar su comportamiento. Las mediciones en el estudiono sobrepasaron los límites permisibles nacionales ni internacionales de calidad del aire; sin embargo se observaron picos anómalos en el caso del dióxido de azufre. Se evaluó la correlación cruzada de las series de tiempo entre los datos reportados por estaciones regionales de la Secretaria de Ambiente del DMQ y los datos obtenidos en este estudio, hallándose que el monóxido de carbono presenta una mayor concentración a filo de calle. Al realizar el análisis de componentes principales (ACP) se determinó varios contaminantes correlacionados, lo que corroboran sus ciclos de formación y demuestran la influencia de factores meteorológicos en la contaminación de aire a filo de calle. Finalmente se determinó que las concentraciones de pm 10 en aire interior son mayores a lo registrado en aire exterior en el sitio de muestreo.Air pollution at the street edge was studied in the Historical downtown of Quito (DMQ) at a point of high vehicular flow by continuous gas monitoring and particulate material between April 5 and 12, 2018. Time profiles were obtained of the pollutant concentrations and their behavior was explained. The measurements in the study did not exceed the national and international permissible limits of air quality, however abnormal peaks were observed in the case of sulfur dioxide. the cross-correlation of the time series between the data reported by regional stations of the secretary of Environment of the DMQ and the data obtained in this study was evaluated, finding that carbon monoxide presents a higher concentration on the street edge. When performing the main components analysis (PCA), several correlated pollutants were determined, which corroborates their formation cycles and demonstrates the influence of meteorological factors on air pollution at the street edge. Finally, it was determined that the concentrations of pm in indoor air are higher than that registered in outdoor air in the sampled point

    Contaminación del aire a filo de calle en Quito, caso estudio Guayaquil y Espejo.

    Get PDF
    Se estudió la contaminación del aire a filo de calle en el Centro Histórico de Quito (DMQ) en un punto de alto flujo vehicular mediante el monitoreo continuo de gases y material particulado entre el 5 y 12 de abril de 2018. Se obtuvieron los perfiles horarios de las concentraciones de contaminantes y se pudo explicar su comportamiento. Las mediciones en el estudiono sobrepasaron los límites permisibles nacionales ni internacionales de calidad del aire; sin embargo se observaron picos anómalos en el caso del dióxido de azufre. Se evaluó la correlación cruzada de las series de tiempo entre los datos reportados por estaciones regionales de la Secretaria de Ambiente del DMQ y los datos obtenidos en este estudio, hallándose que el monóxido de carbono presenta una mayor concentración a filo de calle. Al realizar el análisis de componentes principales (ACP) se determinó varios contaminantes correlacionados, lo que corroboran sus ciclos de formación y demuestran la influencia de factores meteorológicos en la contaminación de aire a filo de calle. Finalmente se determinó que las concentraciones de pm 10 en aire interior son mayores a lo registrado en aire exterior en el sitio de muestreo.Air pollution at the street edge was studied in the Historical downtown of Quito (DMQ) at a point of high vehicular flow by continuous gas monitoring and particulate material between April 5 and 12, 2018. Time profiles were obtained of the pollutant concentrations and their behavior was explained. The measurements in the study did not exceed the national and international permissible limits of air quality, however abnormal peaks were observed in the case of sulfur dioxide. the cross-correlation of the time series between the data reported by regional stations of the secretary of Environment of the DMQ and the data obtained in this study was evaluated, finding that carbon monoxide presents a higher concentration on the street edge. When performing the main components analysis (PCA), several correlated pollutants were determined, which corroborates their formation cycles and demonstrates the influence of meteorological factors on air pollution at the street edge. Finally, it was determined that the concentrations of pm in indoor air are higher than that registered in outdoor air in the sampled point

    A collaboratively derived environmental research agenda for Galapagos

    Get PDF
    Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation. This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced. </jats:p

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

    Get PDF
    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database

    Get PDF
    Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe

    Adaptación escolar de la etnia gitana: relevancia de las variables psicosociales determinantes

    No full text
    El presente estudio tiene como objetivo analizar la integración de los niños pertenecientes a la etnia gitana en edad de escolarización primaria en su grupo escolar e identificar los factores determinantes de esta adaptación. Hemos trabajado con toda la población de escolares del concejo de Corvera de Asturias (compuesta por 42 niños gitanos y 439 no gitanos). Los resultados indican una pobre integración de los niños gitanos en su grupo de clase, tanto en las actividades académicas como en las relativas al tiempo libre y de ocio. Se encontraron factores de riesgo para el rechazo en el conjunto de variables familiares evaluadas, así como en el de las personales. Los factores de riesgo más relevantes para predecir la integración en el grupo de pares son el nivel educativo y académico de los padres y madres, el interés por las actividades escolares de los niños y la sensibilidad social hacia sus compañeros entre otros. Se presentan las implicaciones de estos resultados y las líneas de intervención a desarrollar en el futuro para una mejor integración de la etnia gitana

    Adaptación escolar de la etnia gitana: relevancia de las variables psicosociales determinantes

    No full text
    El presente estudio tiene como objetivo analizar la integración de los niños pertenecientes a la etnia gitana en edad de escolarización primaria en su grupo escolar e identificar los factores determinantes de esta adaptación. Hemos trabajado con toda la población de escolares del concejo de Corvera de Asturias (compuesta por 42 niños gitanos y 439 no gitanos). Los resultados indican una pobre integración de los niños gitanos en su grupo de clase, tanto en las actividades académicas como en las relativas al tiempo libre y de ocio. Se encontraron factores de riesgo para el rechazo en el conjunto de variables familiares evaluadas, así como en el de las personales. Los factores de riesgo más relevantes para predecir la integración en el grupo de pares son el nivel educativo y académico de los padres y madres, el interés por las actividades escolares de los niños y la sensibilidad social hacia sus compañeros entre otros. Se presentan las implicaciones de estos resultados y las líneas de intervención a desarrollar en el futuro para una mejor integración de la etnia gitana

    Resolviendo la variabilidad espacial y temporal del aploramiento noroeste ibérico

    Get PDF
    III Simposio Internacional de Ciencias del Mar, Cádiz, 25-28 de enero de 2012N
    corecore