519 research outputs found

    Organic particle export, remineralization and advection in the North Atlantic mesopelagic layer

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    The mesopelagic layer of the oceans extends between ~200 and 1000 m depth and plays a fundamental role in global biogeochemical cycles and climate. In addition, it hosts a massive biomass of zooplankton and small fish, what is essential to regulate marine resources. However, scientific understanding and predictive capacity of biogeochemical processes in the mesopelagic zone are still underdeveloped. This lack of information has societal and economic costs because there is uncertainty in estimates of oceanic carbon storage (which inform policies for the reduction of carbon dioxide emissions), and it hampers the management of mesopelagic biological resources. In this way, this thesis would address the study of the carbon cycle and the associated biogeochemical processes. The main objective is to analyse the variability of the transport and transformation of particles that carry organic carbon from the surface to the deep sea in the North Atlantic. For this purpose, this study will focus on the analysis of simulations from dynamical (NEMO4 (Madec & NEMO team, 2008)) and biogeochemical (PISCES-v2 (Amount et al., 2015)) models, together with observations from bio-ARGO floats and satellite data

    Posibilidades de la variabilidad genética de encinas y alcornoques en la conservación y recuperación de bosques amenazados por la “seca”

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    Phytophthora cinnamomi Rands. (hongo patógeno del suelo) es el principal responsable del decaimiento de encinas y alcornoques en el Suroeste de la Península Ibérica. Este decaimiento es uno de los problemas ambientales más graves que amenaza la supervivencia y sostenibilidad, tanto ecológica como económica, de las formaciones de Quercus del sur peninsular. Este trabajo analiza la posibilidad del empleo de la variabilidad genética de la resistencia o tolerancia de los árboles al patógeno del suelo Phytophthora cinnamomi

    Geomorphological setting and main technological features of new Middle and Upper Pleistocene sites in the Lower Manzanares River Valley (Madrid, Spain)

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    Las intervenciones arqueológicas llevadas a cabo durante los años 1996 en Tafesa, 2005 en el yacimiento Hospital 12 de Octubre y 2006 en la desembocadura del arroyo Butarque (Villaverde-Barrio de Butarque) situados al sur de la ciudad de Madrid (España), han aportado nuevos conjuntos líticos contextualizados estratigráficamente en los depósitos fluviales pleistocenos correspondientes al tramo inferior del valle del río Manzanares. Los yacimientos arqueológicos analizados se sitúan geomorfológicamente en la denominada “Terraza Compleja del Manzanares” (TCMZ), la cual constituye un nivel fluvial engrosado (20-15 m de potencia) situado entre +22-16 m sobre el cauce actual del río, a lo largo de su margen derecha. Este nivel fluvial ha sido tradicionalmente considerado de edad Pleistoceno medio en base a la industria achelense y complejos faunísticos encontrados en sus niveles inferiores. Ciertamente, Tafesa es un yacimiento situado en la parte inferior-media de la terraza de +22 m con industria achelense y fauna de Pleistoceno medio. Por el contrario, los niveles superiores de esta misma terraza en los sectores del 12 de Octubre y Villaverde-Butarque se encuentran asociados a industrias del Paleolítico inferior y medio ya pertenecientes al Pleistoceno superior, como sugieren el conjunto de dataciones OSL y TL existentes para la zona. Los datos analizados en este trabajo indican que el desarrollo de este nivel de terraza engrosado comienza durante la parte final de Pleistoceno medio y abarca todo el Estadio Isotópico OIS 5, ya dentro del Pleistoceno superiorThe archaeological works developed during the years 1996 in the site of Tafesa, 2005 in the 12 de Octubre Metro Station site and 2006 in the confluence of the Butarque Stream (Villaverde-Barrio de Butarque site) located south of the Madrid City (Spain), have provided new lithic assemblages. These assemblages have been stratigraphically contextualized in the Pleistocene deposits of the Lower Manzanares river valley within the so-called “Manzanares Complex Terrace” (TCMZ). This fluvial terrace constitutes an anomalous thickened (20-15m) deposit at +22-16m above the present river thalweg mainly developed along the right (southern) valley margin. This fluvial level has been traditionally considered of middle Pleistocene age on the basis of the acheulian lithics and faunal assemblages typically located within its lower stratigraphic layers. Certainly, the Tafesa is a fluvial terrace site at +22 m with acheulian industry and middle Pleistocene faunal remains at its lower sedimentary sequence. However, the upper sedimentary levels of this same terrace in the 12 de Octubre y Villaverde-Butarque sites throw lithic assemblages of the lower and upper Paleolithic belonging to upper Pleistocene, as suggested by the available set of TL and OSL dates for the zone. The analyses developed in this study indicate that the development of this thickened fluvial terrace started during the end of the middle Pleistocene, but also comprise the whole Oxygen Isotopic Stage OIS 5 during the upper Pleistocene

    Synthetic alpha-synuclein fibrils cause mitochondrial impairment and selective dopamine neurodegeneration in part via iNOS-mediated nitric oxide production

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    Producción CientíficaIntracellular accumulation of α-synuclein (α-syn) are hallmarks of synucleinopathies, including Parkinson's disease (PD). Exogenous addition of preformed α-syn fibrils (PFFs) into primary hippocampal neurons induced α-syn aggregation and accumulation. Likewise, intrastriatal inoculation of PFFs into mice and non-human primates generates Lewy bodies and Lewy neurites associated with PD-like neurodegeneration. Herein, we investigate the putative effects of synthetic human PFFs on cultured rat ventral midbrain dopamine (DA) neurons. A time- and dose-dependent accumulation of α-syn was observed following PFFs exposure that also underwent phosphorylation at serine 129. PFFs treatment decreased the expression levels of synaptic proteins, caused alterations in axonal transport-related proteins, and increased H2AX Ser139 phosphorylation. Mitochondrial impairment (including modulation of mitochondrial dynamics-associated protein content), enhanced oxidative stress, and an inflammatory response were also detected in our experimental paradigm. In attempt to unravel a potential molecular mechanism of PFFs neurotoxicity, the expression of inducible nitric oxide synthase was blocked; a significant decline in protein nitration levels and protection against PFFs-induced DA neuron death were observed. Combined exposure to PFFs and rotenone resulted in an additive toxicity. Strikingly, many of the harmful effects found were more prominent in DA rather than non-DA neurons, suggestive of higher susceptibility to degenerate. These findings provide new insights into the role of α-syn in the pathogenesis of PD and could represent a novel and valuable model to study DA-related neurodegeneration

    Isotope-reinforced polyunsaturated fatty acids improve Parkinson’s disease-like phenotype in rats overexpressing α-synuclein

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    Producción CientíficaLipid peroxidation is a key to a portfolio of neurodegenerative diseases and plays a central role in α-synuclein (α-syn) toxicity, mitochondrial dysfunction and neuronal death, all key processes in the pathogenesis of Parkinson's disease (PD). Polyunsaturated fatty acids (PUFAs) are important constituents of the synaptic and mitochondrial membranes and are often the first molecular targets attacked by reactive oxygen species (ROS). The rate-limiting step of the chain reaction of ROS-initiated PUFAs autoxidation involves hydrogen abstraction at bis-allylic sites, which can be slowed down if hydrogens are replaced with deuteriums. In this study, we show that targeted overexpression of human A53T α-syn using an AAV vector unilaterally in the rat substantia nigra reproduces some of pathological features seen in PD patients. Chronic dietary supplementation with deuterated PUFAs (D-PUFAs), specifically 0.8% D-linoleic and 0.3% H-linolenic, produced significant disease-modifying beneficial effects against α-syn-induced motor deficits, synaptic pathology, oxidative damage, mitochondrial dysfunction, disrupted trafficking along axons, inflammation and DA neuronal loss. These findings support the clinical evaluation of D-PUFAs as a neuroprotective therapy for PD

    Geoarqueología y paleontología de los depósitos de Pleistoceno Superior del antiguo Arroyo Abroñigal (Cuenca de Manzanares, Madrid): el yacimiento de Puente de los Tres Ojos

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    La excavación arqueológica del yacimiento del Puente de los Tres Ojos, próximo a la calle Cerro Negro (Madrid), ha aportado nuevos datos para profundizar en el conocimiento de la ocupación humana y en la reconstrucción paleoambiental del valle del antiguo arroyo Abroñigal, cuyo curso fluvial funcionó como afluente del río Manzanares posiblemente desde antes del Pleistoceno Superior hasta la segunda mitad del siglo XX. En el presente artículo se incluyen los aspectos geomorfológicos y cronoestratigráficos de los niveles excavados, documentándose varias secuencias fluviales y aluviales de relleno de la margen derecha del fondo de valle del Abroñigal en su tramo inferior. Durante la excavación se registró un amplio conjunto lítico, formado en su mayoría por piezas recuperadas en niveles de arenas y gravas correspondientes a episodios fluviales de media energía, a las que hay que añadir un porcentaje menor localizado en niveles de limos arcillosos y arenas finas. La mayor parte del conjunto lítico responde a sistemas técnicos propios del Paleolítico Medio, aunque destaca la presencia testimonial de piezas del Paleolítico Superior, además de restos de fauna de mamíferos correspondientes al Pleistoceno Superior, todo ello en niveles datados por OSL entre 14.400 y 11.170 años BP aproximadament

    Spondyloarthropathies in Autoimmune Diseases and Vice Versa

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    Polyautoimmunity is one of the major clinical characteristics of autoimmune diseases (ADs). The aim of this study was to investigate the prevalence of ADs in spondyloarthropathies (SpAs) and vice versa. This was a two-phase cross-sectional study. First, we examined the presence of ADs in a cohort of patients with SpAs (N = 148). Second, we searched for the presence of SpAs in a well-defined group of patients with ADs (N = 1077) including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren's syndrome (SS). Among patients with SpAs, ankylosing spondylitis was observed in the majority of them (55.6%). There were two patients presenting with SS in the SpA group (1.4%) and 5 patients with autoimmune thyroiditis (3.5%). The global prevalence of ADs in SpAs was 4.86%. In the ADs group, there were 5 patients with SpAs (0.46%). Our results suggest a lack of association between SpAs and ADs. Accordingly, SpAs might correspond more to autoinflammatory diseases rather than to ADs

    Expression of the major and pro-oncogenic H3K9 lysine methyltransferase SETDB1 in non-small cell lung cancer

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    SETDB1 is a key histone lysine methyltransferase involved in gene silencing. The SETDB1 gene is amplified in human lung cancer, where the protein plays a driver role. Here, we investigated the clinical significance of SETDB1 expression in the two major forms of human non-small cell lung carcinoma (NSCLC), i.e., adenocarcinoma (ADC) and squamous cell carcinoma (SCC), by combining a meta-analysis of transcriptomic datasets and a systematic review of the literature. A total of 1140 NSCLC patients and 952 controls were included in the association analyses. Our data revealed higher levels of SETDB1 mRNA in ADC (standardized mean difference, SMD: 0.88; 95% confidence interval, CI: 0.73–1.02; p less than 0.001) and SCC (SMD: 0.40; 95% CI: 0.13–0.66; p = 0.003) compared to non-cancerous tissues. For clinicopathological analyses, 2533 ADC and 903 SCC patients were included. Interestingly, SETDB1 mRNA level was increased in NSCLC patients who were current smokers compared to non-smokers (SMD: 0.26; 95% CI: 0.08–0.44; p = 0.004), and when comparing former smokers and non-smokers (p = 0.009). Furthermore, the area under the curve (AUC) given by the summary receiver operator characteristic curve (sROC) was 0.774 (Q = 0.713). Together, our findings suggest a strong foundation for further research to evaluate SETDB1 as a diagnostic biomarker and/or its potential use as a therapeutic target in NSCLC. © 2019 by the authors. Licensee MDPI, Basel, Switzerland
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