27 research outputs found

    Human impact on the Suances estuary (Cantabria, N Spain): geochemical and microfaunal proxies in its modern sediments

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    Metal and benthic foraminiferal contents from surface sediments of the Suances estuary have been analyzed in order to characterize the geochemical and microfaunal responses to the present environmental conditions in this coastal area. High levels of Zn, Pb, and Cd together with reduced numbers of foraminifera present in this estuary suggest very negative and persistent environmental conditions through time as a consequence of mining, industrial and urban effluents disposal in this ecosystem during the last 160 years. Multiproxy geological analysis represents a powerful tool for the historical monitoring of both the past and future environmental transformation processesSe ha analizado el contenido en metales y foraminíferos bentónicos de los sedimentos superficiales de la ría de Suances con el fin de caracterizar la respuesta geoquímica y microfaunística a las condiciones ambientales actuales en esta zona costera. Los elevados niveles de Zn, Pb y Cd junto con las reducidas cantidades de foraminíferos sugieren una situación ambiental muy negativa y persistente en el tiempo asociada a los vertidos mineros, industriales y urbanos efectuados en este ecosistema durante los últimos 160 años. El análisis geológico multidisciplinar representa una buena herramienta para el seguimiento histórico, tanto pretérito como futuro, de los procesos de transformación ambienta

    Sedimentation rate and contamination levels profile of potentially toxic elements in the Limoncocha lagoon RAMSAR wetland in the Ecuadorian Amazon

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    The aim of this study is to analyze the recent sedimentation rate in the center of the Limoncocha lagoon, a Ramsar site in the Ecuadorian Amazon, using the 210Pb dating method and identifying the potentially toxic elements along a 50 cm sediment core. A strategy based on the application of three single and four integrated indices is used to evaluate trace element contamination with depth. Single indices show mainly As and Mo, and Cu, Ba, Cd, Ni, and Pb to a lesser extent, as responsible elements of a minor enrichment between −10 and −40 cm. The multielement slight pollution shows a mixture of potential contamination sources, probably due to agricultural, oil activities, and urban wastewater discharges. However, integrated indices applied, classify the complete core as without potential risk. The 210Pbexcess profile shows three differentiated sections. A surface section where new materials with lower concentrations have been found, probably due to the underground currents that connect the lagoon and the nearby Napo River; a central section where CF-CS model and mass accumulation rate calculations provide a sediment accumulation rate of 0.56 ± 0.03 cm y−1; finally, a deeper section with a constant 210Pbexces profile, showing sediment reworking probably due to local flooding’s

    Recent anthropogenic transformation of the Pasaia bay (Guipuzcoa, N. Spain): multiproxy analysis of its sedimentary record

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    El registro sedimentario reciente en la bahía de Pasaia ha sido estudiado mediante 3 sondeos submareales. Los testigos muestran un sedimento de grano fino, unos valores muy elevados de contaminantes metálicos y una presencia muy escasa de microfauna, sugiriendo malas condiciones ambientales que han sido persistentes durante al menos las últimas 6 décadas. Estas circunstancias son decisivas para desarrollar una adecuada gestión de este medio estuarino.The recent sedimentary record of the Pasaia bay has been analysed using 3 subtidal cores. These contain fine-grained sediments, very high metallic pollutants and very scarce microfauna. They are indicative of negative environmental conditions that have been persistent in this area at least during the last 6 decades. These characteristics are decisive in order to perform an adequate management of this estuarine setting.Trabajo financiado por los proyectos Antropicosta (CGL2013-41083-P), Harea-Grupo de Investigación en Geología Litoral (GV, IT976-16) y Unidad de Formación e Investigación en Cuaternario (UPV/EHU,UFI11/09)

    Estudio del impacto humano en una Reserva Natural: las Marismas de Santoña (Cantabria, España)

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    ABSTRACT: The Santoña Marshes Nature Reserve is one of the most important ecosystems of the Spanish Cantabrian coast due to its ecological value as a wintering area for migratory birds. Since an increase in population and substantial changes in the use of land have been observed in this area during the last century, the aim of this work was to attempt to see if anthropogenic activities are recorded in the accumulating sediments. Two sediment cores (50 cm length) were collected for isotopic dating (210Pb and 137Cs) and geochemical study (heavy metals). The data indicate an increasing trend in sedimentation rates during the last century, probably related to the progressive loss of the estuarine domains and the changes in their original hydrodynamic conditions due to infilling and the construction of dykes. However, no significant anthropogenic inputs of heavy metals have been detected in recent times.RESUMEN: La Reserva Natural de las Marismas de Santoña, situada en la costa cantábrica, posee un gran valor ecológico como lugar de invernada de aves migratorias. Dado el importante aumento de la presencia humana en la zona durante el último siglo, este trabajo tiene como objetivo estudiar si estas actividades antrópicas han dejado su huella en los sedimentos acumulados. Para ello se ha abordado la datación isotópica (137Cs y 210Pb) y el estudio geoquímico (metales pesados) de dos sondeos de 50 cm de longitud. Los resultados obtenidos señalan la existencia de un importante incremento en las tasas de sedimentación durante el ultimo siglo, posiblemente relacionado con la pérdida progresiva de la superficie y de las dinámicas estuarinas como consecuencia de los rellenos y de la construcción de diques. Sin embargo, no se han detectado niveles significativos de contaminación en metales pesados en los sedimentos más recientes

    Adaptation of the impregnation conditions of cellulosic transformer solids to the use of natural esters

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    Transformers’ operation and end of life mainly depend on its solid insulation. It is subjected to different stresses that cause the cellulose degradation. The ageing process is highly dependent on the moisture content and the correct impregnation. In the impregnation process, the dielectric coolant fluid is absorbed by the rest of the transformer porous materials, especially the insulating cellulosic materials, conditioning their properties. Due to the transition to a more sustainable energy system, new lines of research that explore alternatives to traditional mineral oils, as esters, are being developed. However, it is necessary to study their behaviour in the different manufacturing processes and during the operating life of the transformers for their future application. In this paper, the changes to be made in the impregnation process to include a soya-based liquid, taking the place of mineral oil, and considering as solid dielectrics Crepe Paper, Diamond Dotted Paper (DDP), Kraft and Presspaper (PSP) are studied.Work supported in part by the Spanish Ministry of Science and Innovation (National Research Project Asset Management of Biodegradable-Fluid-Based Transformers under Grant PID2019-107126RB-C22/AEI/ 10.13039/501100011033), by the Universities and Research Council of the Government of Cantabria (Project ‘‘Biodegradable Fluids in Electrical Power Transformers: Solid Dielectric Impregnation and Thermal Modeling with Thermal Hydraulic Network Models (THNM)’’ under Grant VP32, 2019-2), and by the University of Cantabria (Industrial Doctoral Program 2016, Scholarship DI13)

    The geomorphic dimension global change : risks and opportunities

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    Fil: Hurtado, Martín Adolfo. Instituto de Geomorfología y Suelos (IGS). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Forte, Luis M.. Instituto de Geomorfología y Suelos (IGS). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Bruschi, Viola María. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: Bonachea, Jaime. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: Rivas, Victoria. DGUOT. Universidad de Cantabria. Santander; EspañaFil: Gómez Arozamena, José. DCMQ. Universidad de Cantabria. Santander; EspañaFil: Dantas Ferreira, Marcilene. Departamento de Engenharia Civil. Universidade Federal de SÆo Carlos. SÆo Paulo; BrasilFil: Remondo, Juan. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: González, A.. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: Díaz de Terán, J.R.. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: Salas, L.. Departamento de Ciencias de la Tierra y Física de la Materia Condensada. Universidad de Cantabria; EspañaFil: Cendrero, Antonio. Instituto de Geomorfología y Suelos (IGS). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

    Environmental evolution of the Deba estuary (Basque Coast Geopark) during the Holocene and Anthropocene

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    RESUMEN: Se han estudiado las asociaciones de foraminíferos de dos sondeos largos y uno corto en el estuario del Deba con el fin de realizar la interpretación ambiental de su registro sedimentario. Adicionalmente, se han llevado a cabo análisis geoquímicos en el sondeo corto, y análisis microfaunísticos y geoquímicos en ocho muestras superficiales tomadas a lo largo del estuario. Los resultados han permitido la reconstrucción de sus ambientes sedimentarios durante el Holoceno y el Antropoceno. El registro holoceno está principalmente controlado por el ascenso relativo del nivel marino, mientras que las muestras superficiales y el sondeo corto muestran la influencia antropogénica en los sedimentos más recientes.ABSTRACT: Benthic foraminiferal assemblages of two long boreholes and one short core drilled in the Deba estuary were studied for environmental interpretation of its sedimentary record. Additional geochemical analyses in the short core, together with the microfaunal and geochemical analysis of eight surface samples along the estuary were also performed. The results allow for the reconstruction of the Deba estuary environment during the Holocene and Anthropocene. The Holocene record is mainly controlled by the relative sea-level rise, whereas the surface samples and the short core exhibit human influence in the most recent sediments.Trabajo financiado por los proyectos Antropicosta (CGL2013-41083-P), Harea-Grupo de Investigación en Geología Litoral (IT976-16) y Estuarios del Geoparque de la Costa Vasca (US13/02). Francisco Fatela (Universidade de Lisboa) y un/a revisor/a anónimo/a mejoraron la versión original de este trabajo con sus indicaciones. Contribución nº 49 de la Unidad de Investigación Geo-Q Zentroa (Laboratorio Joaquín Gómez de Llarena). N. El Bani Altuna ha estado financiada por la beca no. 223259 para Centros de Excelencia del Consejo de Investigación Noruego

    Melatonin Modulation of Radiation and Chemotherapeutics-induced Changes on Differentiation of Breast Fibroblasts

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    Melatonin exerts oncostatic actions and sensitizes tumor cells to chemotherapeutics or radiation. In our study, we investigated the e ects of docetaxel, vinorelbine, and radiation on human breast fibroblasts and its modulation by melatonin. Docetaxel or vinorelbine inhibits proliferation and stimulates the di erentiation of breast preadipocytes, by increasing C/EBP and PPAR expression and by downregulating tumor necrosis factor (TNF ), interleukin 6 (IL-6), and IL-11 expression. Radiation inhibits both proliferation and di erentiation through the downregulation of C/EBP and PPAR and by stimulating TNF expression. In addition, docetaxel and radiation decrease aromatase activity and expression by decreasing aromatase promoter II and cyclooxygenases 1 and 2 (COX-1 and COX-2) expression. Melatonin potentiates the stimulatory e ect of docetaxel and vinorelbine on di erentiation and their inhibitory e ects on aromatase activity and expression, by increasing the stimulatory e ect on C/EBP and PPAR expression and the downregulation of antiadipogenic cytokines and COX expression. Melatonin also counteracts the inhibitory e ect of radiation on di erentiation of preadipocytes, by increasing C/EBP and PPAR expression and by decreasing TNF expression. Melatonin also potentiates the inhibitory e ect exerted by radiation on aromatase activity and expression by increasing the downregulation of promoter II, and COX-1 and COX-2 expression. Our findings suggest that melatonin modulates regulatory e ects induced by chemotherapeutic drugs or radiation on preadipocytes, which makes it a promising adjuvant for chemotherapy and radiotherapy sensibilization.Funding: This work was supported by a grant from the Spanish Economy and Competitiveness Ministry (SAF2016-77103-P) and from Instituto de Investigación Sanitaria Valdecilla (IDIVAL) (APG/12)

    Recent sediments dating using short-lived radionuclides

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    Se presentan las características principales del método de datación de sedimentos recientes mediante el radioisótopo natural ²¹⁰Pb y su validación utilizando radionucleidos artificiales tales como ¹³⁷Cs y ²³⁹,²⁴⁰Pu. Se hace una revisión de los principios generales de esta metodología, se aportan recomendaciones prácticas para la recogida de testigos sedimentarios en el campo y su posterior procesamiento en el laboratorio, se describen diferentes técnicas analíticas utilizadas en la determinación de sus concentraciones y se explican brevemente varios modelos para la interpretación de los perfiles obtenidos. Por último, se incluyen ejemplos prácticos de su aplicación en secuencias sedimentarias procedentes de distintos ambientes marinos (estuario, bahía y plataforma continental) en el norte de la Península Ibérica.The main characteristics of the dating method of recent sediments using the natural radioisotope ²¹⁰Pb and its validation with artificial radionuclides such as ¹³⁷Cs and ²³⁹,²⁴⁰Pu are presented. A review of the general principles of this methodology is made, practical recommendations for the collection of sedimentary cores in the field and their subsequent processing in the laboratory are provided, several analytical techniques used to measure their concentrations are described and several models for the interpretation of the profiles are briefly explained. Finally, practical examples of its application in sedimentary sequences from different marine environments (estuary, bay and continental shelf) in the northern Iberian Peninsula are also included.Agradecimientos: Este artículo se ha inspirado en el manual de referencia publicado por Sanchez-Cabeza, J.A., Díaz-Asencio, M., Ruiz-Fernández, A.C., eds. (2012). Radiocronología de sedimentos costeros utilizando 210Pb: Modelos, Validación y Aplicaciones. Organismo Internacional de Energía Atómica, Viena, 105 pp., donde se profundizan diferentes aspectos tratados aquí. Trabajo financiado por los proyectos RTI2018-095678-B-C21, MCIU/AEI/FEDER, UE (MINECO) e IT976-16 (EJ/GV). Dos revisoras/es anónimas/os mejoraron el manuscrito original con sus comentarios y sugerencias. Contribución nº 56 de la Unidad de Investigación Geo-Q Zentroa (Laboratorio Joaquín Gómez de Llarena)
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