793 research outputs found

    NGC 6705 a young α\alpha-enhanced Open Cluster from OCCASO data

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    The stellar [α\alpha/Fe] abundance is sometimes used as a proxy for stellar age, following standard chemical evolution models for the Galaxy, as seen by different observational results. In this work we show that the Open Cluster NGC6705/M11 has a significant α\alpha-enhancement [α\alpha/Fe]>0.1>0.1 dex, despite its young age (\sim300 Myr), challenging the current paradigm. We use high resolution (R>65,000>65,000) high signal-to-noise (\sim70) spectra of 8 Red Clump stars, acquired within the OCCASO survey. We determine very accurate chemical abundances of several α\alpha elements, using an equivalent width methodology (Si, Ca and Ti), and spectral synthesis fits (Mg and O). We obtain [Si/Fe]=0.13±0.050.13\pm0.05, [Mg/Fe]=0.14±0.070.14\pm0.07, [O/Fe]=0.17±0.070.17\pm0.07, [Ca/Fe]=0.06±0.050.06\pm0.05 and [Ti/Fe]=0.03±0.030.03\pm0.03. Our results place these cluster within the group of young [α\alpha/Fe]-enhanced field stars recently found by several authors in the literature. The ages of our stars have an uncertainty of around 50 Myr, much more precise than for field stars. By integrating the cluster's orbit in several non-axisymmetric Galactic potentials, we establish the M11's most likely birth radius to lie between 6.8-7.5 kpc from the Galactic center, not far from its current position. With the robust Open Cluster age scale, our results prove that a moderate [α\alpha/Fe]-enhancement is no guarantee for a star to be old, and that not all α\alpha-enhanced stars can be explained with an evolved blue straggler scenario. Based on our orbit calculations, we further argue against a Galactic bar origin of M11.Comment: 10 pages, 6 figures, accepted in A&

    De Cabo Negro al río Lián. Yacimientos litorales en el Norte de Marruecos a la luz de la Carta Arqueológica (2009-2010)

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    Trabajo presentado al III Seminario Hispano-Marroquí «Arqueología y Turismo en el Círculo del Estrecho. Estrategias para la Puesta en Valor de los recursos patrimoniales del Norte de Marruecos», celebrado entre el 14 y el 16 de abril de 2011 en Algeciras.[ES]: Presentamos los resultados preliminares de las campañas de prospección llevadas a cabo entre Cabo Negro y el Río Lián (Norte de Marruecos) durante los años 2009 y 2010. Dicha prospección se enmarca en el Proyecto Carta Arqueológica del Norte de Marruecos que desde el año 2008 la Universidad de Cádiz, la Universidad Abdelmalek Essaadi y el Institut National des Sciences de l’Archeologie et du Patrimoine vienen desarrollando. [FR]: Nous présentons ici les résultats préliminaires des campagnes de prospection réalisées entre le Cap Noir et le fleuve Lián (nord du Maroc) durant les années 2009 et 2010. La dite prospection encadre dans le Projet la Carte Archéologique du Nord du Maroc que dès le 2008 l’Université de Cadix, l’Université Abdelmalek Esaadi et l’Institut National des Sciences de l’Archeologie et du Patrimoine développent[FR]: Il s’agit dans ce travail de présenter les résultats préliminaires des campagnes de prospections archéologiques réalisées en 2009 et 2010 dans la zone située entre Ras el Aswad (Cabo Negro) et oued Lian (Nord du Maroc). Ce bilan s’inscrit dans le cadre du projet « Carte Archéologique du Nord du Maroc: Région Tanger-Tétouan » entamé depuis 2008 par une équipe maroco-espagnol dont les institutions de parrainage sont : l’Université Abdelmalek Essaadi, l’Institut National des Sciences d’Archéologie et du Patrimoine et l’Université de Cádiz.Peer Reviewe

    Hippo pathway effectors YAP1/TAZ induce an EWS–FLI1‐opposing gene signature and associate with disease progression in Ewing sarcoma

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    YAP1 and TAZ (WWTR1) oncoproteins are the final transducers of the Hippo tumor suppressor pathway. Deregulation of the pathway leads to YAP1/TAZ activation fostering tumorigenesis in multiple malignant tumor types, including sarcoma. However, oncogenic mutations within the core components of the Hippo pathway are uncommon. Ewing sarcoma (EwS), a pediatric cancer with low mutation rate, is characterized by a canonical fusion involving the gene EWSR1 and FLI1 as the most common partner. The fusion protein is a potent driver of oncogenesis, but secondary alterations are scarce, and little is known about other biological factors that determine the risk of relapse or progression. We have observed YAP1/TAZ expression and transcriptional activity in EwS cell lines. Analyses of 55 primary human EwS samples revealed that high YAP1/TAZ expression was associated with progression of the disease and predicted poorer outcome. We did not observe recurrent SNV or copy number gains/losses in Hippo pathway‐related loci. However, differential CpG methylation of the RASSF1 locus (a regulator of the Hippo pathway) was observed in EwS cell lines compared with mesenchymal stem cells, the putative cell of origin of EwS. Hypermethylation of RASSF1 correlated with the transcriptional silencing of the tumor suppressor isoform RASFF1A, and transcriptional activation of the pro‐tumorigenic isoform RASSF1C, which promotes YAP1/TAZ activation. Knockdown of YAP1/TAZ decreased proliferation and invasion abilities of EwS cells and revealed that YAP1/TAZ transcription activity is inversely correlated with the EWS–FLI1 transcriptional signature. This transcriptional antagonism could be explained partly by EWS–FLI1‐mediated transcriptional repression of TAZ. Thus, YAP1/TAZ may override the transcriptional program induced by the fusion protein, contributing to the phenotypic plasticity determined by dynamic fluctuation of the fusion protein, a recently proposed model for disease dissemination in EwS

    Short communication: Goat colostrum quality: Litter size and lactation number effects

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    The quality of colostrum of Murciano-Granadina goats was studied to establish the transition period and the time when milk can be marketed. Forty-three dairy goats were used: 19 primiparous (15 single births; 4 multiple births) and 24 multiparous (10 single births; 14 multiple births). Samples were collected every 12 h during the first week postpartum. Physicochemical parameters and somatic cell count were determined. Analysis of variance with repeated measures was used to study the effect of different factors: postpartum time, litter size, lactation number, their interactions, and production level on colostrum. Postpartum time had a significant effect on all parameters studied, which decreased along the first week of lactation, whereas lactose, pH, and conductivity increased. Based on these results, colostrum secretion takes place until 36 h postpartum (hpp). In relation to other factors of variation studied, the lactation number influenced most colostrum components, whereas the litter size only affected the pH value, protein and lactose content. The production level influenced only the protein and dry matter contents, with an inverse relationship. Milk produced during the period between 36 and 96 hpp is considered transition milk, which should not be commercialized. Milk collected after 4 d postpartum (96 hpp) could be marketed, ensuring that its composition does not present a risk in the dairy industry.This work was part of the AGL-2009-11524 Project funded by the Spanish Ministry of Science and Innovation (Madrid, Spain). The authors are grateful to ZEU-Inmunotec (Zaragoza, Spain) for their support.Romero Rueda, T.; Beltrán Martínez, MC.; Rodríguez Garcia, M.; Marti-De Olives A.; Molina Pons, MP. (2013). Short communication: Goat colostrum quality: Litter size and lactation number effects. Journal of Dairy Science. 96(12):7526-7531. https://doi.org/10.3168/jds.2013-6900S75267531961

    Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

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    The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

    Might some gamma ray bursts be an observable signature of natural wormholes?

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    The extragalactic microlensing scenario for natural wormholes is examined. It is shown that the main features of wormhole lensing events upon the light of distant Active Galactic Nuclei (AGNs) are similar to some types of already observed Gamma Ray Bursts (GRBs). Using recent satellite data on GRBs, an upper limit to the negative mass density -- O(1036){\cal O} (10^{-36}) g cm3^{-3} -- under the form of wormhole-like objects is presented.Comment: extended version, additions on GRB physics, background sources and cosmological consequences. Two ps figures. Accpeted for publication in Phys. Rev.

    Epizoochory in Parrots as an Overlooked Yet Widespread Plant–Animal Mutualism

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    Plant–animal interactions are key to sustaining whole communities and ecosystem function. However, their complexity may limit our understanding of the underlying mechanisms and the species involved. The ecological effects of epizoochory remain little known compared to other seed dispersal mechanisms given the few vectors identified. In addition, epizoochory is mostly considered non-mutualistic since dispersers do not obtain nutritional rewards. Here, we show a widespread but unknown mutualistic interaction between parrots and plants through epizoochory. Combining our observations with photos from web-sources, we recorded nearly 2000 epizoochory events in 48 countries across five continents, involving 116 parrot species and nearly 100 plant species from 35 families, including both native and non-native species. The viscid pulp of fleshy fruits and anemochorous structures facilitate the adherence of tiny seeds (mean 3.7 × 2.56 mm) on the surface of parrots while feeding, allowing the dispersion of these seeds over long distances (mean = 118.5 m). This parrot–plant mutualism could be important in ecosystem functioning across a wide diversity of environments, also facilitating the spread of exotic plants. Future studies should include parrots for a better understanding of plant dispersal processes and for developing effective conservation actions against habitat loss and biological invasions.This research was funded by Severo Ochoa Program (SVP-2014-068732), Action COST “ParrotNet” (ES1304), and Loro Parque Fundación (PP-146-2018-1). E.S.-G. is funded by a Ramón y Cajal contract (RYC-2019-027216I) from the Spanish Ministry of Science and Innovation

    Prevalence of Symptomatic Osteoarthritis in Spain: EPISER2016 Study

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    [Resumen] Introducción. La Sociedad Española de Reumatología elaboró en el año 2000 el estudio EPISER2000 para conocer la prevalencia de la artrosis y otras enfermedades reumáticas en España. Los cambios sociodemográficos y en los hábitos de vida ocurridos en los últimos años en España justifican actualizar los datos de las enfermedades reumáticas (EPISER2016). Objetivo. Estimar la prevalencia de artrosis sintomática de columna cervical, columna lumbar, cadera, rodilla y mano, en población adulta en España. Material y métodos. Estudio transversal de base poblacional. Se realizó un muestreo aleatorizado polietápico estratificado y por conglomerados. Los participantes fueron contactados por teléfono para cumplimentar un cuestionario de cribado de artrosis. El reumatólogo confirmaba o descartaba el diagnóstico. Se utilizaron los criterios-clínicos-ACR para diagnosticar artrosis de manos y los criterios clínico-radiológicos-ACR para diagnosticar la artrosis de rodilla y cadera. Resultados. La prevalencia de artrosis en España en una o más de las localizaciones estudiadas fue de 29,35%. La prevalencia de artrosis-cervical fue del 10,10% y de artrosis-lumbar del 15,52%. Ambas son más frecuentes en mujeres y a mayor edad, así como en personas con niveles de estudios bajos y obesidad. La prevalencia de artrosis de cadera fue del 5,13% y la de artrosis de rodilla del 13,83%; estas se asocian con el sexo femenino, sobrepeso y obesidad, menor frecuencia en nivel de estudios alto y con la edad. La prevalencia de la artrosis de mano fue del 7,73%. Es más frecuente en mujeres, obesas, con bajo nivel de estudios y mayor edad. Conclusiones. El estudio EPISER2016 es el primero que analiza la prevalencia de artrosis sintomática en 5 localizaciones (columna cervical, lumbar, rodilla, cadera y manos) en España. La artrosis de la columna lumbar es la más prevalente.[Abstract] Introduction. The Spanish Society of Rheumatology carried out the EPISER2000 study in 2000 to determine the prevalence of osteoarthritis and other rheumatic diseases in the Spanish population. Recent sociodemographic changes and lifestyle habits in Spain justified updating the epidemiological data on osteoarthritis and other rheumatic diseases (EPISER2016-study). Objective. To estimate the prevalence of symptomatic osteoarthritis of the cervical spine, lumbar spine, hip, knee and hand in the adult population in Spain. Material and methods. Cross-sectional population-based study. A multistage and stratified random cluster sampling was carried out. The participants were contacted by telephone to complete an osteoarthritis screening questionnaire. A rheumatologist confirmed or discarded the diagnosis. The ACR-clinical-criteria were used to diagnose hand-osteoarthritis and the ACR-clinical-radiological criteria to diagnose knee- and hip-osteoarthritis. To estimate the prevalence and its 95% confidence interval, weights were calculated according to the probability of selection in each of the sampling stages. Results. The prevalence of osteoarthritis in Spain in one or more of the locations studied was 29.35%. The prevalence of cervical-osteoarthritis was 10.10% and of lumbar-osteoarthritis 15.52%. Both are more frequent in women and at older ages, as well as in people with low levels of education and obesity. The prevalence of hip-osteoarthritis was 5.13%, that of knee-osteoarthritis 13.83%, these are associated with female sex, overweight and obesity. The prevalence of hand osteoarthritis was 7.73%. It is more frequent in women, who are obese, with a low educational level and who are older. Conclusion. The EPISER2016 study is the first to analyse the prevalence of symptomatic osteoarthritis in 5 locations (cervical, lumbar, knee, hip and hands) in Spain. Lumbar spine osteoarthritis is the most prevalent.EPISER2016 ha sido financiado por Celgene, Laboratorios, Gebro Pharma, Merck Sharp and Dohme de España, Pfizer y Sanofi-Aventis. Los financiadores no han intervenido en el diseño del estudio, recogida ni análisis de datos, ni en la redacción de este artículo. IRP yMS fueron financiados con programas Miguel Servet II y Contrato Río Hortega-Fondo de Investigación Sanitaria (CPII17/00026 y CM17/00101), respectivamente. El Fondo de Investigación Sanitaria, integrado en el Plan Nacional de Programa Científico, Desarrollo e Innovación Tecnológica 2013-2016, es financiado por el ISCIII-Subdirección General de Evaluación y Promoción de la Investigación-Fondo Europeo de Desarrollo Regional (FEDER) «Una forma de hacer Europa

    Evaluación de las condiciones experimentales básicas para la producción de biomasa a partir de la microalga Chlorella vulgaris

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    La utilización de las microalgas como fuente de energía para la obtención de aceite y biodiesel presenta muchas ventajas respecto a otras materias primas. Las microalgas tienen un alto rendimiento por superficie cultivada, diversifica el tipo de combustible a producir y no compite con la producción de alimentos, siendo clasificado como un biocombustible de tercera generación. En el presente trabajo se evalúa la influencia del rendimiento de biomasa microalgal bajo diferentes condiciones de cultivo. La microalga Chlorella vulgaris fue cultivada a escala de laboratorio utilizando 6 elermeyers de 250 mL siguiendo la metodología descrita en el medio decultivo Watanabe modificado. Las condiciones de cultivo fueron 28°C ± 1°C con un pH aproximado entre 6 y 7. A partir del recuento celular mediante microscopía fue posible determinar la velocidad de crecimiento de la microalga en estudio con una duración de diez días; alcanzándose la máxima concentración de células en el cultivo con vitaminas y suministro de aire de 450.5×104 células/mL. A los cinco días los cultivos con vitaminas mostraron 8 veces mayor rendimiento, mientras que sin estas 7 veces. El mayor incremento se registró para el cultivo con vitaminas y suministro permanentede aire el cual incrementó su producción de biomasa 20 veces. Los resultados obtenidos en esta investigación demuestran el potencial que tiene la microalga Chlorella vulgaris para su uso con fines energéticos, encaminados fundamentalmente a la obtención de biodiesel
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