76 research outputs found

    Intramolecular C-C Coupling Reactions of Alkynyl, Vinylidene, and Alkenylphosphane Ligands in Rhodium(III) Complexes

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    Electrophilic attack with methyl trifluoromethanesulfonate or tetrafluoroboric acid, to new alkynyl rhodium complexes containing alkenylphosphanes, leads to butenynyl coupling products or to the unprecedented rhodaphosphacycle complexes Rh(¿5-C5Me5){¿4-(P, C, C, C)-iPr2PCH2C(=CH2)C(CH2R)C=C(R)}]BF4] (R = Ph (11a), p-tol (11b)). These complexes 11a, b can be explained as a result of the coupling of three organic fragments in the molecule, the alkynyl, the vinylidene, generated in situ by reaction with HBF4 (A), and the C-C double bond from the alkenylphosphane. DFT computational studies on the formation of complex 11a suggest the 2 + 2] intramolecular cycloaddition between the double bond of the allylphosphane and the Ca-Cß of the vinylidene A as the most plausible pathway for this reaction

    Large Scale dynamics of Brown trout populations across Navarra Rivers (North Spain)

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    Most studies on the population dynamics of stream-living salmonids have attempted to elucidate the causes of variation in demographic traits or population abundance by analyzing population time series vis-á-vis environmental data. In order to express the results on a scale compatible with fishery management strategies, most studies have been done at the scale of a stream reach, a stream or a river basin with few studies focused on the population dynamics at larger geographic scales. Our goal is to determine the extent to which the effects of both, exogenous and endogenous factors actually describe the variations in abundance of brown trout populations inhabiting separated river basins across a large and environmentally heterogeneous territory. We tested whether the trout abundance across a large territory involving distinct populations could be described by determining the extent to which exogenous and endogenous drivers underlie the per capita population growth rate estimated from long-term time series in a way similar to that previously assessed at smaller geographical scales. We have developed a simple multivariate linear model that synthetically combines an index of large-scale climate variation with mean population abundance. This model has been built on the basis of a data set encompassing 18-year quantifications of abundance at 68 sampling stations. The results of our simulation model predict mean trout abundance with less than 10% error

    Web based system architecture for long pulse remote experimentation

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    Remote experimentation (RE) methods will be essential in next generation fusion devices. Requirements for long pulse RE will be: on-line data visualization, on-line data acquisition processes monitoring and on-line data acquisition systems interactions (start, stop or set-up modifications). Note that these methods are not oriented to real-time control of fusion plant devices. INDRA Sistemas S.A., CIEMAT (Centro de Investigaciones Energéticas Medioambientales y Tecnológicas) and UPM (Universidad Politécnica de Madrid) have designed a specific software architecture for these purposes. The architecture can be supported on the BeansNet platform, whose integration with an application server provides an adequate solution to the requirements. BeansNet is a JINI based framework developed by INDRA, which makes easy the implementation of a remote experimentation model based on a Service Oriented Architecture. The new software architecture has been designed on the basis of the experience acquired in the development of an upgrade of the TJ-II remote experimentation system

    Response of fish communities in rivers subjected to a high sediment load

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    Erosion and sediment yield are a significant problem in the Guadalquivir River basin. Such phenomena are largely driven by a land use devoted to intensive cultivation of olive trees, with a large socioeconomic influence in Andalusia. This sediment overload in rivers causes serious impacts on all fluvial ecosystem components. In this study we assess the chronic effect of sediment yield on fish communities at 104 river sites located in two different sub-catchments ? the Bembézar and Guadajoz rivers ? both with different lithological composition and erosion rates. Sediment yield was estimated using a semi-quantitative Factorial Score Model (FSM), developed specifically for Spanish rivers. The fish populations of both basins were evaluated in composition and abundances by the study of Fernández-Delgado et al., 2014. The influence of sediment yield on the fish community was analyzed using General Additive Models. The sediment yield was higher in the Guadajoz basin (921 T/Km2 per year) than in Bembézar (701 T/Km2 per year). In the former, fish communities were poorer in both fish density and diversity, with Luciobarbus sclateri as the only substantially present species and a significant relationship between sediment yield and load, and fish density. In contrast, in the Bembézar basin, sediment yield was correlated with total fish density, including Luciobarbus sclateri, Pseudochondrostoma willkommii, Cobitis paludica, Iberochondrostoma lemmingii, Anaecypris hispanica, and Cyprinus carpio. Intermediate values of sediment yield led to maximum densities, while those higher decreased the density of these species

    Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure

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    Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 104 hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF

    HESML: A scalable ontology-based semantic similarity measures library with a set of reproducible experiments and a replication dataset

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    This work is a detailed companion reproducibility paper of the methods and experiments proposed by Lastra-Díaz and García-Serrano in (2015, 2016) [56–58], which introduces the following contributions: (1) a new and efficient representation model for taxonomies, called PosetHERep, which is an adaptation of the half-edge data structure commonly used to represent discrete manifolds and planar graphs; (2) a new Java software library called the Half-Edge Semantic Measures Library (HESML) based on PosetHERep, which implements most ontology-based semantic similarity measures and Information Content (IC) models reported in the literature; (3) a set of reproducible experiments on word similarity based on HESML and ReproZip with the aim of exactly reproducing the experimental surveys in the three aforementioned works; (4) a replication framework and dataset, called WNSimRep v1, whose aim is to assist the exact replication of most methods reported in the literature; and finally, (5) a set of scalability and performance benchmarks for semantic measures libraries. PosetHERep and HESML are motivated by several drawbacks in the current semantic measures libraries, especially the performance and scalability, as well as the evaluation of new methods and the replication of most previous methods. The reproducible experiments introduced herein are encouraged by the lack of a set of large, self-contained and easily reproducible experiments with the aim of replicating and confirming previously reported results. Likewise, the WNSimRep v1 dataset is motivated by the discovery of several contradictory results and difficulties in reproducing previously reported methods and experiments. PosetHERep proposes a memory-efficient representation for taxonomies which linearly scales with the size of the taxonomy and provides an efficient implementation of most taxonomy-based algorithms used by the semantic measures and IC models, whilst HESML provides an open framework to aid research into the area by providing a simpler and more efficient software architecture than the current software libraries. Finally, we prove the outperformance of HESML on the state-of-the-art libraries, as well as the possibility of significantly improving their performance and scalability without caching using PosetHERep

    Tuberculosis y vitamina D: una relación intrigante

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    La tuberculosis permanece como la enfermedad infecciosa que más muertes ha causado a lo largo de la historia de la existencia humana, sin poderse aún lograr su control. En años recientes ha emergido un cúmulo importante de evidencia clínica acerca de la función de la vitamina D (calcitriol o 1,25 hidroxivitamina D) en un papel que va más allá de la homeostasis del calcio. Su papel en el sistema inmunológico es muy interesante vinculando su déficit como un factor de riesgo contribuyente y así mismo fisiopatológico en un gran número de enfermedades autoinmunes e infecciosas. Dentro de éstas se destaca la tuberculosis, enfermedad endémica en nuestro país y en la cual el déficit de dicho compuesto (vitamina D) crea un factor de riesgo para desarrollar esta enfermedad en su forma activa. Presentamos una revisión detallada de los estudios que explican el papel de la vitamina D en la susceptibilidad para el desarrollo de tuberculosis y los resultados de los estudios clínicos de suplencia de la misma publicados a la fecha

    Resveratrol inhibits nonalcoholic fatty liver disease in rats

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of nonalcoholic fatty liver disease (NAFLD) is high. NAFLD is linked to obesity, diabetes mellitus, and hypertriglyceridemia. Approximately 20% of patients with NAFLD will eventually develop cirrhosis. Our purpose was to investigate whether resveratrol decreased hepatic steatosis in an animal model of steatosis, and whether this therapeutic approach resulted in a decrease in tumor necrosis factor α (TNF-α) production, lipid peroxidation and oxidative stress.</p> <p>Methods</p> <p>Male Wistar CRL: Wi (Han) (225 g) rats were randomized into three groups. A control group (n = 12) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 12) and resveratrol (n = 12) groups were given free access to feed (a high carbohydrate-fat free modified diet) and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. Rats in the resveratrol group were given resveratrol 10 mg daily by the oral route. All rats were killed at 4 weeks and assessed for fatty infiltration and bacterial translocation. Levels of TNF-α in serum, hepatic malondialdehyde (MDA), oxidative stress (superoxide dismutase, glutathione peroxidase, catalase and nitric oxide synthase) and biochemical parameters were measured.</p> <p>Results</p> <p>Fat deposition was decreased in the resveratrol group as compared to the steatosis group (Grade 1 vs Grade 3, P < 0.05). TNF-α and MDA levels were significantly increased in the steatosis group (TNF-α; 33.4 ± 5.2 vs 26.24 ± 3.47 pg/ml and MDA; 9.08 ± 0.8 vs 3.17 ± 1.45 μM respectively, <it>P </it>< 0.05). This was accompanied by increased superoxide dismutase, glutathione peroxidase and catalase and decreased nitric oxide synthase in the liver of resveratrol group significantly (<it>P </it>< 0.05 vs steatosis group). Bacterial translocation was not found in any of the groups. Glucose levels were decreased in the group of rats given resveratrol (<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>Resveratrol decreased NAFLD severity in rats. This effect was mediated, at least in part, by TNF-α inhibition and antioxidant activities.</p
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