300 research outputs found
Thermohaline evolution of the Western Mediterranean Deep Waters since 2005: diffusive stages and interannual renewal injections
A large production of anomalous dense water in the northwestern Mediterranean Sea during winter 2005 led to a widespread abrupt shift in Western Mediterranean deep waters characteristics. This new configuration, the so-called Western Mediterranean Transition (WMT), involved a complex thermohaline structure that was tracked over time through a deep hydrographic station located NE of Minorca Island, sampled 37 times between 2004 and 2017. In this study, the thermohaline evolution of the WMT signal is analyzed in detail. Using a 1-D diffusion model sensitive to double-diffusive mixing phenomena, the contribution to the heat and salt budgets of the deep Western Mediterranean in terms of ventilation and diffusive transference from the intermediate layers above is disentangled. Results show distinct stages in the evolution of the deep waters, driven by background diffusion and intermittent injections of new waters. The progression of a multilayered structure in the deep ocean is well represented through existing parameterizations of salt fingering and diffusive layering processes and makes it possible to infer an independent estimate of regional background diffusivity consistent with current knowledge. Overall, the deep layers of the Western Mediterranean underwent substantial warming (0.059 °C) and salt increase (0.021) between 2004 and 2017, mostly dominated by injections of dense waters in the 2005â2006 and 2011â2013 periods. Thus, within the WMT period, heat uptake rate in the deep Western Mediterranean was substantially higher than that of the intermediate levels in the global ocean.CTM2014â54374âR / BESâ2015â074316VersiĂłn del editor3,17
Integral field spectroscopy of H II region complexes: the outer disc of NGC 6946
This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. GarcĂa-Benito, R., DĂaz, A., HĂ€gele, G.F., PĂ©rez-Montero, E., LĂłpez, J., VĂlchez, J.M., PĂ©rez, E., Terlevich, E., Terlevich, R., D. Rosa-GonzĂĄlez. Integral field spectroscopy of H II region complexes: the outer disc of NGC 6946. Monthly Notices of the Royal Astronomical Society 408 (2010): 2234-225
Larval fish assemblage structure in the surface layer of the northwestern Mediterranean under contrasting oceanographic scenarios
During the summer, the relative influence of resident Atlantic Waters (AW) and new AW largely drives the mesoscale
dynamics around the Balearic Islands (NW Mediterranean). Two principal summer hydrographic scenarios were
identified in the region, differentiated by the relative position of the density front between new and resident AW within
the archipelago and its associated mesoscale activity. In this study, we investigated how those early summer mesoscale
scenarios influence larval fish assemblages, by analyzing data from two cruises representative of these two scenarios
(2004 and 2005). Redundancy analysis was used to assess the variance in the larval fish assemblage that could be significantly
explained by the most parsimonious combination of available environmental variables in both years. While
depth was the most important variable in explaining the larval fish assemblage structure variability observed under
both scenarios, indicators of mesoscale activity (dynamic height, geostrophic velocity) contributed significantly to
understanding the dynamics of the larval fish community. Mesoscale activity was higher in summer 2004, leading to
higher larval fish abundances and zooplankton biomass and lower larval fish diversity than in the unusually warm
summer 2005, which showed lower mesoscale activity. The larval assemblage dynamics are discussed in terms of extrinsic
and species-specific factors.Postprint1,749
Spatial distribution of pyrogenic carbon in Iberian topsoils estimated by chemometric analysis of infrared spectra
Understanding the global carbon (C) cycle is critical to accurately model feedbacks between climate and soil. Thus, many climate change studies focused on soil organic carbon (SOC) stock changes. Pyrogenic carbon (PyC) is one of the most stable fractions of soil organic matter (SOM). Accurate maps based on measured PyC contents are required to facilitate future soil management decisions and soil-climate feedback modelling. However, consistent measurements that cover large areas are rare. Therefore, this study aimed to map the PyC content and stock of the Iberian Peninsula, which covers contrasting climatic zones and has long-term data on wildfire occurrence. A partial least square (PLS) regression using the mid-infrared spectra (1800â400 cmâ1) was applied to a dataset composed of 2961 soil samples from the Iberian component of the LUCAS 2009 database. The values of PyC for LUCAS points were modelled to obtain a map of topsoil PyC by a random forest (RF) approach using 36 auxiliary variables. The results were validated through comparison with documented historical wildfire activity and anthropogenic energy production. A strong relationship was found between these sources and the distribution of PyC. Our study estimates that the accumulated PyC in Iberian Peninsula soils comprises between 3.09 and 20.39% of total organic carbon (TOC) in the topsoil. Forests have higher PyC contents than grasslands, followed by agricultural soils. The incidence of recurrent wildfires also has a notable influence on PyC contents. This study shows the potential of estimating PyC with a single, rapid, low cost, chemometric method using new or archived soil spectra, and has the ability to improve soil-climate feedback modelling. It also offers a possible tool for measuring, reporting and verifying soil C stocks, which is likely to be important moving forward if soils are used as sinks for C sequestration
Late glacial and post-glacial deposits of the Navamuno peatbog (Iberian Central System): Chronology and paleoenvironmental implications
The Navamuno peatbog (Sierra de Bejar, western Spain) is a ~14 ha pseudo-endorheic depression with boundaries defined by a lateral moraine of the Cuerpo de Hombre paleoglacier and fault-line scarps on granite bedrock. The stratigraphy of the Navamu~no peatbog system is characterized here using borehole data to a depth of 20 m. An integrated interpretation from direct-push coring, dynamic probing boreholes and handheld auger drillings advances our knowledge of the Navamu~no polygenetic infill. Correlating this data with those obtained in other studies of the chronology and evolutionary sequence of the Cuerpo de Hombre paleoglacier has enabled us to establish the sequence of the hydrological system in the Navamuno depression. During the Late Pleistocene (MIS2), the depression was dammed by the Cuerpo de Hombre glacier and fed by its lateral meltwaters, and was filled with glaciolacustrine deposits. The onset of the Holocene in Navamuno is linked to a flat, fluviotorrential plain with episodes of local shallow pond/peat bog sedimentation. This evolutionary sequence is congruent with the age model obtained from available radiocarbon dating, obtaining 19 ages from ~800 cal yr BP (at depth 1.11 m) to ~16800 cal yr BP (at depth 15.90e16.0 m). Finally, the sedimentary record enabled interpretation of the environmental changes occurring in this zone during the late glacial (from the Older Dryas to the Younger Dryas) and postglacial (Holocene) stages, placing them within the paleoclimatic context of the Iberian Peninsula and Mediterranean regions
Analysis of the dynamic co-expression network of heart regeneration in the zebrafish.
The zebrafish has the capacity to regenerate its heart after severe injury. While the function of a few genes during this process has been studied, we are far from fully understanding how genes interact to coordinate heart regeneration. To enable systematic insights into this phenomenon, we generated and integrated a dynamic co-expression network of heart regeneration in the zebrafish and linked systems-level properties to the underlying molecular events. Across multiple post-injury time points, the network displays topological attributes of biological relevance. We show that regeneration steps are mediated by modules of transcriptionally coordinated genes, and by genes acting as network hubs. We also established direct associations between hubs and validated drivers of heart regeneration with murine and human orthologs. The resulting models and interactive analysis tools are available at http://infused.vital-it.ch. Using a worked example, we demonstrate the usefulness of this unique open resource for hypothesis generation and in silico screening for genes involved in heart regeneration
Oncogenic Role of Secreted Engrailed Homeobox 2 (EN2) in Prostate Cancer
Engrailed variant-2 (EN2) has been suggested as a potential diagnostic biomarker; however, its presence and functional role in prostate cancer (PCa) cells is still controversial or unknown. Here, we analyzed 1) the expression/secretion profile of EN2 in five independent samples cohorts from PCa patients and controls (prostate tissues and/or urine) to determine its utility as a PCa biomarker; and 2) the functional role of EN2 in normal (RWPE1) and tumor (LNCaP/22Rv1/PC3) prostate cells to explore its potential value as therapeutic target. EN2 was overexpressed in our two cohorts of PCa tissues compared to control and in tumor cell lines compared with normal-like prostate cells. This profile was corroborated in silico in three independent data sets [The Cancer Genome Atlas(TCGA)/Memorial Sloan Kettering Cancer Center (MSKCC)/Grasso]. Consistently, urine EN2 levels were elevated and enabled discrimination between PCa and control patients. EN2 treatment increased cell proliferation in LNCaP/22Rv1/PC3 cells, migration in RWPE1/PC3 cells, and PSA secretion in LNCaP cells. These effects were associated, at least in the androgen-sensitive LNCaP cells, with increased AKT and androgen-receptor phosphorylation levels and with modulation of key cancer-associated genes. Consistently, EN2 treatment also regulated androgen-receptor activity (full-length and splicing variants) in androgen-sensitive 22Rv1 cells. Altogether, this study demonstrates the potential utility of EN2 as a non-invasive diagnostic biomarker for PCa and provides novel and valuable information to further investigate its putative utility to develop new therapeutic tools in PCa
IEOOS, the Spanish Institute of Oceanography integrated ocean Observing System
Since its foundation, 100 years ago, the Spanish Institute of Oceanography (IEO) has been observing and measuring the ocean characteristics. Some systems like the tide gauges network has been working for more than 60 years. The IEO standard sections began at different moments depending on the local projects, and nowadays there are XXX coastal stations and XXX deep ones that are systematically sampled, taking physical as well as biochemical measurements. At this moment, the IEO Observing System (IEOOS) includes 4 permanent moorings equipped with currentmeters, an open-sea ocean-meteorological buoy offshore Santander and an SST satellital image reception station. It also supports the Spanish contribution to the ARGO international program with 47 deployed profilers, and continuous monitoring thermosalinometers, meteorological stations and ADCP installed on the IEO research vessels. All these networks are linked to international iniciatives like SeaDataNet, Emodnet, IbiROOS and MONGOOS. The system is completed with the IEO contribution to the RAIA and Gibraltar observatories, and the development of regional prediction models. All these systematic measurements allow IEO to give responses to ocean research activities, official agencies requirements and industrial and main society demands
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