273 research outputs found

    Cryptanalysis of a novel cryptosystem based on chaotic oscillators and feedback inversion

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    An analysis of a recently proposed cryptosystem based on chaotic oscillators and feedback inversion is presented. It is shown how the cryptosystem can be broken when Duffing's oscillator is considered. Some implementation problems of the system are also discussed.Comment: 9 pages, 3 figures, latex forma

    Variabilidade e tendencias interanuais no fitoplancto mariño das costas de Galicia

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    13 páginas, 2 tablas, 7 figuras[EN] The available information on phytoplankton biomass and species composition in Galician waters was studied to find out their spatial variability as well as the annual trends. The areas covered included the oceanic zone, the shelf and the inner part of the Rías. In general a significant drop in diatoms was observed. The series also indicated an increase in dinoflagellates, although it was not statistically significant. The diatom species related to blooms in the area declined, whereas those indicative of weak upwelling or stratificacion showed an increase. Even though not all trends were significant, the available data are consistent with the decrease in upwelling intensity over the last 40 years. The results also suggest that effects of climate changes on phytoplankton may be delayed for several years. In any case, the large oceanographic variability of the region, along with the lack of continuity of some o[GA] Co obxecto de coñecer a variabilidade espacial e as tendencias interanuais do fitoplancto galego, estudáronse as series de datos históricos dispoñibles para Galicia, abarcando desde a zona oceánica ata as zonas máis costeiras das rías e a plataforma continental. En xeral, observouse unha diminución significativa das diatomeas, especialmente na zona oceánica. Tamén hai indicios dun incremento, aínda que non significativo, dos dinoflaxelados. O descenso das diatomeas foi debido á caída das abundancias de especies propias de floracións, tanto primaverais como estivais asociadas ao afloramento. Así mesmo, aumentaron as especies de diatomeas propias de afloramentos febles ou estratificación. Malia que non todas as tendencias foron significativas, os resultados son coherentes cunha diminución da intensidade do afloramento nos últimos 40 anos e un cambio nas condicións climáticas desde a década de 1980. Os resultados indican que os efectos dos cambios climáticos sobre o fitoplancto se poden manifestar con varios anos de retardo. Con todo, a alta variabilidade oceanográfica da zona, especialmente de alta frecuencia, e mais a falta de continuidade de moitas series de datos dificultan o establecemento de relacións claras entre cambios ambientais e o fitoplanctoEsta análise das tendencias do fitoplancto en Galicia foi financiada parcialmente pola Consellería de Medio Ambiente e Desenvolvemento Sostible (Programa CLIGAL) e polo proxecto REFORZA (PGIDT06RMA60401PR) da Consellería de Innovación e Industria da Xunta de Galicia. O traballo de María Huete-Ortega estivo financiado polo Programa Predoutoral de Formación de Profesorado Universitario do Ministerio de Educación y Ciencia.Peer reviewe

    A plant economics spectrum in Mediterranean forests along environmental gradients: Is there coordination among leaf, stem and root traits?

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    12 páginas..- 4 figuras.-- 70 referencias.--Supporting Information: Additional Supporting Information may be found in the online version of this article: Appendix S1. Species list.--Appendix S2. Functional traits list.--Appendix S3. Phylogenetic tree.-- Appendix S4. Pearson correlation coefficients between traits.-- Appendix S5. Relationships between morphologicaltraits, carbon isotope fraction and leaf chlorophyll.-- Appendix S6. Phylogenetic generalized least square analysis.-- Appendix S7. Non-metric multidimensional scaling analysis.-- Appendix S8. Illustration of the scale effects.Questions: Is there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seed mass? Location: Mediterranean forests and shrublands, Sierra Morena mountains, Córdoba, southern Spain. Methods: We selected nine woody plant communities along a natural local gradient of soil water and nutrient availability. We measured key leaf, stem, root and whole-plant traits for 38 dominant woody plant species. The variation across species of 15 functional traits (of the leaf, stem and root) was analysed and coordination among them was tested. We explored the relationships between these traits (hereafter 'resource-use traits' due to their close association with the acquisition-conservation trade-off) and plant height and seed mass. Finally, we compared results at species level with those calculated at community level, considering community-weighted means (CWMs). Results: We found a significant coordination between traits belonging to different plant organs, and propose the existence of a plant economics spectrum in Mediterranean forests along the environmental gradient. However, weaker relationships were found within groups of species under similar environmental conditions. We did not find the expected orthogonal relationships between plant height, seed mass and resource-use traits. Relationships among functional traits were stronger at the community level than at the species level. Conclusions: This study reveals a high degree of functional coordination between traits belonging to different plant organs at both species and community level, and suggests the existence of a plant economics spectrum across 38 Mediterranean woody plant species. However, this general trend of functional coordination between organs became weaker or disappeared when considering restricted groups of species belonging to environmentally similar sites (e.g. dry vs wet sites), suggesting that the diversification of strategies within communities is not related to the economics spectrum at a lower spatial scale. Interestingly, the high degree of coordination between resource-use traits and seed mass at the community level seems to support the tolerance-fecundity model, which predicts an inverse relationship between fecundity and stress tolerance. © 2015 International Association for Vegetation Science.We thank Miguel Verdú for help with the phylogenetic tree and analyses and Jose Rafael Vera for plant trait analyses. We also thank Jard ın Botánico de Córdoba (Francisca Herrera) and the Semillas Cantueso Company (José Angel Cantueso) for providing seedmass data. We are very grateful to Francesco de Bello for interesting comments on previous versions of the manuscript. This study was funded by the Spanish MEC coordinated project DIVERBOS (CGL2011-30285-C02-01 and C02-02), the Andalusian ANASINQUE project (PGC2010-RNM-5782), the Life + Biodehesa Project (11/BIO/ES/000726), ECO-MEDIT (CGL2014-53236-R) and European FEDER funds. Dr. DavidWalker revised the Englis

    Combined sub-optimal doses of Rosuvastatin and Bexarotene impairs angiotensin II-induced arterial mononuclear cell adhesion through inhibition of Nox5 signaling pathways and increased RXR/PPARα and RXR/PPARγ interactions

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    Aim: Mononuclear cell (MC) infiltration into the arterial subendothelium is a key event in atherogenesis. Rosuvastatin (Rosu) and bexarotene (Bex) exert anti-inflammatory activity, but serious dose-related adverse effects have emerged. The need for safer and effective strategies to prevent and treat atherosclerosis led us to test the effect of combined use of both drugs on angiotensin II (Ang-II)-induced arterial MC recruitment. Results: Vehicle, Rosu (10-30 nM), Bex (0.3-1 μM), or a combination of both were administered to human umbilical arterial endothelial cells (HUAECs) 20 h before stimulation with 1 μM Ang-II (4 h). Surprisingly, a combination of Rosu (10 nM)+Bex (0.3 μM), which did not influence Ang-II-induced MC recruitment when either stimulus was studied alone, significantly reduced this response. This effect was accompanied by diminished Ang-II-induced ICAM-1, VCAM-1, and CX3CL1 endothelial expression and CXCL1, CXCL8, CCL2, and CCL5 production. Preincubation of HUAECs with Rosu+Bex inhibited Nox5 expression and Nox5-induced RhoA activation stimulated by Ang-II through increased RXRα, PPARα, and PPARγ expression in addition to RXRα/PPARα and RXRα/PPARγ interactions. In vivo, combined but not single administration of Rosu (1.25 mg/kg/day) and Bex (10 mg/kg/day) significantly diminished Ang-II-induced arteriolar leukocyte adhesion in the cremasteric microcirculation of C57BL/6 mice and atherosclerotic lesion formation in apoE(-/-) mice subjected to an atherogenic diet. Innovation and conclusion: Combined administration of Bex+Rosu at suboptimal doses may constitute a new alternative and effective therapy in the control of the vascular inflammation associated to cardiometabolic disorders, since they synergize in their anti-inflammatory actions and may counteract their associated adverse effects

    Distribución de los suelos del sector noroccidental de Sierra Nevada. Granada

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    En el levantamiento de suelos del sector Noroccidental de Sierra Nevada, se han cartografiado y descrito 15 unidades básicas de suelos y 4 unidades misceláneas de tierras. Se analizan los controles edafogenéticos de las unidades, la extensión areal de las mismas y los caracteres más destacables de los suelos modales. Los inceptisoles ocupan el 47,8% del total del área, las unidades misceláneas el 25,8%, los entisoles el 23,2% y los mollisoles el 3,2%. Las unidades mayoritarias (Xerumbrept típico y éntico, Criumbrept típico y éntico) se desarrollan sobre rocas ácidas, en pendientes entre 15% a 55% y hasta 2.800 m. de altitud, bajo vegetación de matorral.In a soil survey of the Northwest area of Sierra Nevada, fifteen soil units and four miscelaneous units have been mapped and described. Pedogenic controls, areal extension and the most important characteristics of these units have been analized. The 47,8"10 of the total area are inceptisols, 25,8% are miscelaneous units, 2 3,2% are entisols and 3.2% are mollisols. Typic Xerumbrept, entic Xerumbrept, typic Cryumbrept and entic Cryumprept are the most extrensive units. These are developed on acidic roe k with a slope between 15 to 55%, under bush vegetation and so far as 2.800 m. of limit altitude

    Distribución de los suelos del sector noroccidental de Sierra Nevada. Granada

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    In a soil survey of the Northwest area of Sierra Nevada, fifteen soil units and four miscelaneous units have been mapped and described. Pedogenic controls, areal extension and the most important characteristics of these units have been analized. The 47,8% of the total area are inceptisols, 25,8% are miscelaneous units, 23,2% are entisols and 3.2% are mollisols. Typic Xerumbrept, entic Xerumbrept, typic Cryumbrept and entic Cryumprept are the most extrensive units. These are developed on acidic rock with a slope between 15 to 55%, under bush vegetation and so far as 2.800 m. of limit altitude.En el levantamiento de suelos del sector Noroccidental de Sierra Nevada, se han cartografiado y descrito 15 unidades básicas de suelos y 4 unidades misceláneas de tierras. Se analizan los controles edafogenéticos de las unidades, la extensión areal de las mismas y los caracteres más destacables de los suelos modales. Los inceptisoles ocupan el 47,8% del total del área, las unidades misceláneas el 25,8%, los entisoles el 23,2% y los mollisoles el 3,2%. Las unidades mayoritarias (Xerumbrept típico y éntico, Criumbrept típico y éntico) se desarrollan sobre rocas ácidas, en pendientes entre 15% a 55% y hasta 2.800 m. de altitud, bajo vegetación de matorral

    The Economics Spectrum Drives Root Trait Strategies in Mediterranean Vegetation

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    [EN] Extensive research efforts are devoted to understand fine root trait variation and to confirm the existence of a belowground root economics spectrum (RES) from acquisitive to conservative root strategies that is analogous to the leaf economics spectrum (LES). The economics spectrum implies a trade-off between maximizing resource acquisition and productivity or maximizing resource conservation and longevity; however, this theoretical framework still remains controversial for roots. We compiled a database of 320 Mediterranean woody and herbaceous species to critically assess if the classic economics spectrum theory can be broadly extended to roots. Fine roots displayed a wide diversity of forms and properties in Mediterranean vegetation, resulting in a multidimensional trait space. The main trend of variation in this multidimensional root space is analogous to the main axis of LES, while the second trend of variation is partially determined by an anatomical trade-off between tissue density and diameter. Specific root area (SRA) is the main trait explaining species distribution along the RES, regardless of the selected traits. We advocate for the need to unify and standardize the criteria and approaches used within the economics framework between leaves and roots, for the sake of theoretical consistency.S

    Los inceptisoles y entisoles del sector occidental de la Sierra de Gador (Almería)

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    Morphological and physicochemical properties of five Entisols and Inceptisols from west area of Sierra de Gádor are studied. "Soil Taxonomy" is the employed classification. Most soils are developed 'in situ' or upon colluvium derived from limestony and dolomitic marbles. 400 to 2.124 m. is the range of altitude. The slopes are variables. The vegetation is a degradated brushwood and reforestated pine woods. The moisture regime is Xeric; the temperature regime changes from Termi to Mesic at 1.000 m. The soils are tipic Xerorthents (three profils) and calcixerollic Xerochrepts (two profils). The analytical and morphological characteristics are variables owing to differencies in pedological evolution within the studied soils. But there are two characteristics in common: the high quantities of the alcalinoterreal bases controled by the parent material, and the absence of mollic epipedón owing to the degradation of climatic vegetation and parallel degradation or /and destruction of mineral organic soil horizons.En el presente estudio se analizan los caracteres morfológicos, las propiedades fisico-quírnicas y la clasificación a nivel de subgrupo de los suelos presentes en el Sector Occidental de la Sierra de Gádor, que pertenecen a los órdenes Entisol e Inceptisol de la taxonomía americana de suelos. Son suelos desarrollados sobre materiales calizo-dolomíticos "in situ" o coluvionados. La altitud oscila entre 400 y 2. 124 m. La pendiente es muy variable, desde llano o casi llano a fuertemente escarpado. Soportan un matorral degradativo y pinares de repoblación. El régimen de humedad es Xérico y el de temperatura Térmico hasta los 1.000 m. y Mésico por encima de esta cota. Los cinco perfiles muestreados se han clasificado como Xerorthent típicos y dos como Xerochrept calcixeróllicos. Los cinco perfiles muestreados se han clasificado, tres como Xerorthent típidiados, como respuesta a diferencias en evolución edáfica, exceptuando aquellos que dependen estrechamente del elevado contenido en bases alcalino térreas del material de origen. El carácter común más relevante es la carencia de epipedón móllico, provocada por la degradación del horizonte orgánicomineral al destruir la vegetación climácica

    Caracterización de la capacidad agrológica de los suelos del sector noroeste de Sierra Nevada (Granada)

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    The soil map of the Northwest area of the Sierra Nevada it has been interpreted for agronomic purposes by the Spain Agricultural Ministry Scheme, called "Agrological Capacity characterization of the Soil of the Spain, Scale 1.50.000" . In this area the agrological capacity subclasses are: IVs, VIIw, VIs, VIc, Vle and VlIIe. The dominant classes are VII and VIII because the medium slopes are greater than 30 OJo. The subclasse Vle is frequent also (22-23 % of slope). Another subclasses and classes are in minor quantities. The slope and the mean anual temperature are the most important restraints. The surface stoniness, the surface rockiness and the soil moisture regime are important also. AH the results point out the suitability of this area for forestry, grassland and wildlife conservation.Se emplea el esquema del Ministerio de Agricultura Español denominado: "Caracterización de la Capacidad Agrológica de los Suelos de España a escala 1 :50.000", para interpretar desde un punto de vista agronómico la cartografía de suelos del Sector Noroeste de Sierra Nevada. Las subclases de capacidad agrológica presentes en el área son: IVs, VIw, VIs, Vlc, Vle, VIIe, VIIle. Las clases dominantes son la VII y la VIII, ya que las pendientes de casi toda el área superan el 30 OJo. Le sigue en abundancia la subclase Vle, localizada en las pendientes de la clase D (valor medio de 22 a 23%). El resto de las clases y subclases son minoritarias y aparecen de forma puntual. Las limitaciones de mayor importancia en el establecimiento de las clases de capacidad son en primer lugar, la pendiente y la temperatura y en segundo lugar la pedregosidad superficial, la rocosidad superficial y el exceso de humedad en el suelo. Estos resultados indican que los cultivos agrícolas (sólo posibles en los suelos de la clase IVs) se restringen a pequeñas zonas diseminadas por todo el área y que la mayor parte tiene vocación forestal, pastoral y de reserva natural

    Hypoxia-inducible factor 2α drives hepatosteatosis through the fatty acid translocase CD36

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    Background & Aims: Molecular mechanisms by which hypoxia might contribute to hepatosteatosis, the earliest stage in non-alcoholic fatty liver disease (NAFLD) pathogenesis, remain still to be elucidated. We aimed to assess the impact of hypoxia-inducible factor 2α (HIF2α) on the fatty acid translocase CD36 expression and function in vivo and in vitro. Methods: CD36 expression and intracellular lipid content were determined in hypoxic hepatocytes, and in hypoxic CD36- or HIF2α -silenced human liver cells. Histological analysis, and HIF2α and CD36 expression were evaluated in livers from animals in which von Hippel-Lindau (Vhl) gene is inactivated (Vhl -deficient mice), or both Vhl and Hif2a are simultaneously inactivated (Vhl Hif2α -deficient mice), and from 33 biopsy-proven NAFLD patients and 18 subjects with histologically normal liver. Results: In hypoxic hepatocytes, CD36 expression and intracellular lipid content were augmented. Noteworthy, CD36 knockdown significantly reduced lipid accumulation, and HIF2A gene silencing markedly reverted both hypoxia-induced events in hypoxic liver cells. Moreover livers from Vhl -deficient mice showed histologic characteristics of non-alcoholic steatohepatitis (NASH) and increased CD36 mRNA and protein amounts, whereas both significantly decreased and NASH features markedly ameliorated in Vhl Hif2α -deficient mice. In addition, both HIF2α and CD36 were significantly overexpressed within the liver of NAFLD patients and, interestingly, a significant positive correlation between hepatic transcript levels of CD36 and erythropoietin (EPO), a HIF2α -dependent gene target, was observed in NAFLD patients. Conclusions: This study provides evidence that HIF2α drives lipid accumulation in human hepatocytes by upregulating CD36 expression and function, and could contribute to hepatosteatosis setup. f/f f/f /f f/f f/f f/fThis work was supported by PI13/01299, PI17/00535 and CIBEREHD from Instituto de Salud Carlos III (ISCIII/FEDER, Spain) to CGM; CP14/00181, PI16/00823 and PI19/00123 (ISCIII/FEDER, Spain), and Beca Eduardo Gallego 2016 (Fundación Francisco Cobos, Spain) to AGR; SAF2016-76815 (Ministerio de Economía y Competitividad/FEDER, Spain), 534/C/2016 (TV3 Marató, Spain) and CIBERCV (ISCIII/FEDER, Spain) to JA
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