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Importance of geochemical transformations in determining submarine groundwater discharge-derived trace metal and nutrient fluxes

  • Beck, Aaron J.
  • Tsukamoto, Yoko
  • Tovar-Sánchez, Antonio
  • Huerta-Diaz, Miguel A.
  • Bokuniewicz, Henry J.
  • Sañudo-Wilhelmy, Sergio A.
Seasonal (Spring and Summer 2002) concentrations of dissolved (<0.22 μm) trace metals (Ag, Al, Co, Cu, Mn, Ni, Pb), inorganic nutrients (NO3, PO4, Si), and DOC were determined in groundwater samples from 5 wells aligned along a 30 m shore-normal transect in West Neck Bay, Long Island, NY. Results show that significant, systematic changes in groundwater trace metal and nutrient composition occur along the flowpath from land to sea. While conservative mixing between West Neck Bay water and the groundwaters explains the behavior of Si and DOC, non-conservative inputs for Co and Ni were observed (concentration increases of 10- and 2-fold, respectively) and removal of PO4 and NO3 (decreases to about half) along the transport pathway. Groundwater-associated chemical fluxes from the aquifer to the embayment calculated for constituents not exhibiting conservative behavior can vary by orders of magnitude depending on sampling location and season (e.g. Co, 3.4 × 102- 8.2 × 103 μmol d-1). Using measured values from different wells as being representative of the true groundwater endmember chemical composition also results in calculation of very different fluxes (e.g., Cu, 6.3 × 103 μmol d-1 (inland, freshwater well) vs. 2.1 × 105 μmol d-1(seaward well, S = 17 ppt)). This study suggests that seasonal variability and chemical changes occurring within the subterranean estuary must be taken into account when determining the groundwater flux of dissolved trace metals and nutrients to the coastal ocean. © 2007 Elsevier Ltd. All rights reserved., The experiment in which these measurements were made was supported by the Scientific Committee on Oceanic Research (SCOR) through Working Group 112 (Magnitude of Submarine Groundwater Discharge and its Influence on Coastal Oceanographic Processes), by the Land–Ocean Interaction in the Coastal Zone (LOICZ) project of IGBP, UNESCO’s Intergovernmental Oceanographic Commission (IOC), and the International Hydrologic Program, Peer Reviewed
Proyecto:


Water mass footprints in uneven turbidite system development in the Alboran Sea

  • Ercilla, Gemma
  • Juan, Carmen
  • Alonso, Belén
  • Estrada, Ferran
  • Casas, David
  • García, Marga
  • Farran, Marcel-lí
  • CONTOURIBER Team
  • MONTERA Team
2nd Deep-Water Circulation Congress: The Contourite Log-book, 10-12 September 2014, Ghent, Belgium.-- Ercilla, Gemma ... et. al., Peer Reviewed
Proyecto:


Morphological characterization of contourite and mass-wasting recent processes at the Guadalquivir Bank Margin uplift, Gulf of Cadiz

  • García, Marga
  • Alonso, Belén
  • Vázquez, J. T.
  • Ercilla, Gemma
  • Palomino, Desirée
  • Estrada, Ferran
  • Fernández-Puga, M. C.
  • López-González, Nieves
  • Roque, Cristina
2nd Deep-Water Circulation Congress: The Contourite Log-book, 10-12 September 2014, Ghent, Belgium, Peer Reviewed
Proyecto:


Particulate iron dynamics during FeCycle in subantarctic waters southeast of New Zealand

  • Frew, Russell D.
  • Hutchins, David A.
  • Nodder, Scott D.
  • Sañudo-Wilhelmy, Sergio A.
  • Tovar-Sánchez, Antonio
  • Leblanc, Karine
  • Hare, Clinton E.
  • Boyd, Philip W.
The FeCycle experiment provided an SF6 labeled mesoscale patch of high-nitrate low-chlorophyll (HNLC) water in austral summer 2003. These labeled waters enabled a comparison of the inventory of particulate iron (PFe) in the 45-m-deep surface mixed layer with the concurrent downward export flux of PFe at depths of 80 and 120 m. The partitioning of PFe between four size fractions (0.2-2, 2-5, 5-20, and >20 μm) was assessed, and PFe was mainly found in the >20-μm size fraction throughout FeCycle. Estimates of the relative contribution of the biogenic and lithogenic components to PFe were based on an Al:Fe molar ratio (0.18) derived following analysis of dust/soil from the nearest source of aerosol Fe: the semi-arid regions of Australia. The lithogenic component dominated each of the four PFe size fractions, with medians ranging from 68 to 97% of PFe during the 10-day experiment. The Fe:C ratios for mixed-layer particles were ∼40 μmol/mol. PFe export was ∼300 nmol m-2 d-2 at 80 m depth representing a daily loss of ∼1% from the mixed-layer PFe inventory. There were pronounced increases in the Fe:C particulate ratios with depth, with a five-fold increase from the surface mixed layer to 80 m depth, consistent with scavenging of the remineralized Fe by sinking particles and concurrent solubilization and loss of particulate organic carbon. Significantly, the lithogenic fraction of the sinking PFe intercepted at both 80 in and 120 m was >40%; that is, there was an approximately twofold decrease in the proportion of lithogenic iron exported relative to that in the mixed-layer lithogenic iron inventory. This indicates that the transformation of lithogenic to biogenic PFe takes place in the mixed layer, prior to particles settling to depth. Moreover, the magnitude of lithogenic Fe supply from dust deposition into the waters southeast of New Zealand is comparable to that of the export of PFe from the mixed layer, suggesting that a large proportion of the deposited dust eventually exits the surface mixed layer as biogenic PFe in this HNLC region. Copyright 2006 by the American Geophysical Union., Peer Reviewed
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Benthic storms in the north-western Mediterranean continental rise caused by deep dense water formation

  • Puig, Pere
  • Palanques, Albert
  • Martín, Jacobo
  • Ribó, Marta
  • Guillén, Jorge
2nd Deep-Water Circulation Congress: The Contourite Log-book, 10-12 September 2014, Ghent, Belgium. Session 2: The coupling between oceanographic processes and contourite sedimentation, Peer Reviewed
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Quality of life in older people with dementia: A multilevel study of individual attributes and residential care center characteristics

  • Marventano, S.
  • Prieto Flores, María Eugenia
  • Sanz-Barbero, B.
  • Martín-García, S.
  • Fernández-Mayoralas, Gloria
  • Rojo Pérez, Fermina
  • Martínez-Martín, Pablo
  • Forjaz, M. J.
  • On behalf of Spanish Research Group on Quality of Life and Ageing
Aim: To analyze how the characteristics of institutionalized older people with dementia and residential care centers are associated with the individual’s quality of life (QoL). Methods: Data were collected from a survey carried out on 525 elderly people aged 60 years or older in 14 nursing care homes across Spain. Multilevel linear analysis to assess the differences in QoL level between centers and individuals was carried out. Results: The characteristics of the individuals that were associated with a higher QoL were functional independence, health status and gathering with family, friends or neighbors. In contrast, higher levels of dementia, depression and the length of institutionalization had a negative effect on QoL. In relation to the residential care center characteristics, the availability of geriatricians was associated with higher QoL, compared with those centers with no geriatricians on staff. In addition, public centers (public ownership and publicly-funded residents) were also associated with higher QoL than private/mixed centers. The multilevel analysis showed that the 16.4% of the differences in QoL was related to residence factors. Conclusion: These results reflect the importance of the functional, social, mental and residential dimensions in the QoL of older adults with dementia. Actions devoted to improving these key dimensions would contribute to promote the well-being of this vulnerable population, Peer reviewed
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Mecanismos moleculares de respuesta al estrés sobre la pared celular en Lactococcus lactis

  • Roces, Clara
El éxito de las fermentaciones en la industria láctea depende de la aptitud tecnológica de las cepas iniciadoras basada, entre otras características, en la resistencia a condiciones de estrés. El objetivo de esta Tesis Doctoral ha sido identificar mecanismos moleculares desarrollados por Lactococcus lactis como respuesta y resistencia al estrés ocasionado sobre la pared celular que, en último término, sirvan como base para optimizar su papel industrial como cultivo iniciador en quesería. La lactococina 972 (Lcn972), una bacteriocina que no forma poros en la membrana sino que bloquea la síntesis de peptidoglicano en el septo, y exclusivamente en Lactococcus, ha sido utilizada como herramienta para provocar estrés sobre la pared celular. Las líneas de actuación para cumplir el objetivo planteado han sido: a) determinar la contribución a la supervivencia de L. lactis de genes que responden al estrés sobre su pared celular; b) identificar mecanismos de resistencia a Lcn972, y c) estudiar el papel de la proteasa FtsH en el ciclo infectivo del bacteriofago TP712. En primer lugar se generaron mutantes multicopia y no funcionales del gen llmg0169 y del operón llmg2164-2163, regulados por el sistema de dos componentes CesSR, y que presentan el mayor grado de inducción como respuesta a estrés sobre la pared celular. Los mutantes se sometieron a condiciones de estrés tecnológico (acidez, temperatura, sal, liofilización, compuestos antimicrobianos y bacteriófagos), lo que permitió demostrar que estos genes eran necesarios, pero no suficientes, para garantizar la viabilidad de L. lactis en esas condiciones. En el caso del operón llmg2164-2163, se demostró que era, además, un determinante de resistencia a Lcn972. Por otro lado, la caracterización genética y fenotípica de mutantes de L. lactis resistentes a Lcn972 permitió identificar mecanismos implicados en dicha resistencia. Entre ellos destacó la modificación de la composición del peptidoglicano en las cepas resistentes, con un mayor contenido de muropéptidos tripéptido, en detrimento de los que contienen pentapéptido., Estos mutantes fueron, a su vez, resistentes a otros compuestos antimicrobianos y a la infección por los bacteriófagos c2 y sk1, características deseables en cepas de uso industrial. El análisis genético de los mutantes resistentes a Lcn972 puso de manifiesto una deleción de 22,6 kpb incluyendo, entre otros, genes relacionados con el metabolismo de la maltosa, con la infección del bacteriófago c2 y el sistema de dos componentes F, aunque no se pudo demostrar la implicación directa de ninguno de ellos en la resistencia a Lcn972. También se detectó la activación del gen llmg2447, mediada por la inserción en su promotor de la secuencia de inserción IS981. La sobreexpresión de llmg2447 en L. lactis confirió específicamente resistencia a Lcn972. Por su entorno genético, llmg2447 podría haber formado parte de un sistema ancestral anti-sigma/sigma ECF y haber evolucionado hacia un elemento con función protectora. Por último, se estudió el papel de la proteasa de membrana FtsH, cuyo gen también pertenece al regulón de CesR, en la inducción de profagos como respuesta al daño de la pared celular en L. lactis. Los resultados demostraron que, en ausencia de FtsH, el bacteriófago TP712 no es capaz de propagarse en L. lactis debido a su incapacidad de degradar la pared celular de su hospedador. A esta conclusión se llegó tras descartar experimentalmente la implicación de FtsH en otras fases del ciclo biológico del fago como adsorción, integración como profago, escisión y replicación del ADN fágico, o ensamblaje de las partículas virales. Se demostró que estos viriones eran infectivos, pero permanecían retenidos en el citoplasma tras la inducción del profago en L. lactis ¿ftsH. No se ha podido demostrar su papel en la activación de la holina y se postula su implicación en la regulación de la actividad de la endolisina., Cell Wall-active Bacteriocins and Their Applications Beyond Antibiotic Activity. http://dx.doi.org/10.1007/s12602-012-9116-9 . http://hdl.handle.net/10261/80726, Contribution of the CesR-regulated genes llmg0169 and llmg2164-2163 to Lactococcus lactis fitness. http://dx.doi.org/10.1016/j.ijfoodmicro.2009.06.002 . http://hdl.handle.net/10261/51415, Isolation of Lactococcus lactis mutants simultaneously resistant to the cell wall-active bacteriocin Lcn972, lysozyme, nisin, and bacteriophage c2. http://dx.doi.org/10.1128/AEM.00795-12 . http://hdl.handle.net/10261/81013, The putative lactococcal extracytoplasmic function anti-sigma factor Llmg2447 determines resistance to the cell wall-active bacteriocin Lcn972. http://dx.doi.org/10.1128/AAC.01206-12 . http://hdl.handle.net/10261/81156, Lack of the host membrane protease FtsH hinders release of the Lactococcus lactis bacteriophage TP712. http://dx.doi.org/10.1099/vir.0.057182-0 . http://hdl.handle.net/10261/93382, Peer Reviewed
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(Paleo)circulation models in the Alboran seas during the Pliocene and Quaternary

  • Juan, Carmen
  • Ercilla, Gemma
  • Estrada, Ferran
  • Alonso, Belén
  • Casas, David
  • García, Marga
  • Farran, Marcel-lí
  • CONTOURIBER Team
  • MONTERA Team
  • MOWER Team
2nd Deep-Water Circulation Congress: The Contourite Log-book, 10-12 September 2014, Ghent, Belgium.-- Juan, Carmen ... et. al., Peer Reviewed
Proyecto:


Precipitation in the Mediterranean basin as seen from the 2000-2010 TRMM-3B42-v6 database

  • Sarrand, B.
  • Tovar-Sánchez, Antonio
Sarrand, B. et al., Trabajo presentado en la EGU General Assemby 2012, celebrada del 22 al 27 de septiembre de 2012 en Viena (Austria), This work presents a detailed analysis of 11 yrs of the version 6 of the TRMM-3B42 multi-sensor precipitation product (3-h and 0.25° resolution) from March 2000 to February 2011 over the whole Mediterranean basin and surrounding areas including the Black Sea (25°N-50°N, 10°W-43°E). We first discuss some issues in the data set regarding spatial and temporal discontinuities in coastal areas, and further illustrate a critical underestimation of light rains at latitudes higher than 36-37° that somewhat improves from 2007 on and is associated to the absence of coverage by the Precipitation Radar. North of the radar field of view, it seems that the marine coastal band is subject to a significant under detection of precipitation, whereas, on the opposite, the terrestrial coastal band south of 35°N in North Africa and the Near East shows unrealistic over detection of precipitation. We then evaluate the product against rain gauges with a focus on the western Mediterranean basin and the Adriatic. Our reference rain gauge data set includes about 1 million daily rain reports from more than 260 Mediterranean surface stations from Croatia, France, Italy, Malta, Spain (including 2 stations on the northern coast of Africa) and Tunisia, and from 9 additional non-Mediterranean stations from a flat region in France. It includes stations from almost 20 small Mediterranean islands. The comparison shows a significant correlation between TRMM-3B42v6 and rain gauges but with an overall tendency to underestimation. The average ratio of daily rates between surface stations and TRMM product is ~0.63 with significant regional variations, Corsica showing the poorest results and Spain the best. Over the Mediterranean stations considered, the average rate of success on the occurrence of precipitation (~0.75) is enhanced by the high proportion of dry days in the Mediterranean climate (~4 over 5 on average in the rain gauge data set) and drops off when only days with precipitation recorded at surface stations are considered. Averaging fallout at monthly and annual time scales somewhat improves the comparison to rain gauges. We find that results are better in summer and likely more generally in unstable conditions, as illustrated by a subset of data composed of days with high African dust load over the basin. Using a few TRMM pixels that cover 3 or even 5 surface stations, we further illustrate how the small scale heterogeneity of precipitation is a limitation in the comparison between the integrated view of precipitation from space and the local surface measurements. Finally we integrate the variability of the rainfall geographical distribution at seasonal and annual scales over 5 sub-basins (western and eastern Mediterranean, Adriatic, Aegean, and Black Sea). An increasing trend in annual precipitation in the Mediterranean basin is observed over the decade that is also found at the global scale and appears related to the improving performance of the product with time regarding the detection of light rains, especially over Europe and the Mediterranean. Finally we compare the TRMM-3B42v6 precipitation budget over the basin with comparable budgets from ERA-Interim, HOAPS and CMAP data sets, Peer Reviewed
Proyecto:


Djibouti Ville Drift (SW Mediterranean): Sedimentation and record of bottomcurrent fluctuations during the Pleistocene and Holocene

  • Alonso, Belén
  • Ercilla, Gemma
  • Juan, Carmen
  • Estrada, Ferran
  • García, Marga
  • MONTERA Team
  • MOWER Team
2nd Deep-Water Circulation Congress: The Contourite Log-book, 10-12 September 2014, Ghent, Belgium.-- Alonso, Belén ... et. al., Peer Reviewed
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