631 research outputs found

    Mineralogía, geoquímica y algunos aspectos genéticos de la mina El Diamante- Nariño (Colombia).

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    The Diamante mine is located in the southwestern part of Colombia on the west flank of the Occidental Andes Cordillera. The fluid associated with gold mineralization has a range of salinity between 1.7 to 5.8 wt % NaCl equivalent. Densities vary from 0.58 to 0.92 g/cc. Homogenization temperature averages range between 228-340°C. d34Spyrite values of –7.1 to –5.3‰ and d34SSS = -5.7‰ suggest a mixing of sulfur with sedimentary and magmatic origin. The d18O and dD values for the fluids are 7.6 to 9.6‰ and -74 to -83‰, respectively. The isotopic and fluid inclusion data of ore fluids suggest that the gold mineralization at the Diamante mine may have evolved from mixing of magmatic and meteoric fluids possibly related to intrusion of the nearby Piedrancha Granodiorite of late Miocene age. The gold deposition is attributed to destabilization of the bisulfide complex as a result of decrease of the sulfur activity, through sulfide deposition and/or H2S loss.La mina El Diamante, localizada en la parte Suroccidental de Colombia, se encuentra compuesta por venas cuarzosas enriquecidas en oro. Análisis de inclusiones fluidas, han permitido establecer que el fluido asociado con la mineralización tiene un rango que varía entre 1.7 a 5.8 NaCl equivalente en peso, con un rango de temperatura de homogeneización entre 228-340°C. Los valores de d34Spyrite obtenidos con Isótopos estables de - 7.1 a - 5.3‰ y el valor de d34SSS = -5.7‰ indican para el azufre un origen mixto: sedimentario y magmático. Los valores de d18O y dD de los fluidos fluctúan entre 7.6 a 9.6‰ y -74 a - 83‰ respectivamente. Los datos de isótopos e inclusiones fluidas sugieren que la mineralización aurífera de la mina El Diamante se desarrolló a partir de la mezcla de aguas meteóricas con aguas magmáticas, y posiblemente relacionada a la intrusión del Stock de Piedrancha de edad Mioceno Tardío. La deposición del oro es atribuida a la desestabilización del complejo bisulfuro, como resultado de la disminución de actividad del azufre a través de la deposición y/o perdida de H2S

    Conservation of the Illinois flora: A climate change vulnerability assessment of 73 plant species

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    It will be important for land managers, ecological researchers and policymakers to understand how predicted climate changes may affect the flora of Illinois. A climate change vulnerability assessment was completed in 2011 for the162 Animal Species in Greatest Need of Conservation using NatureServe’s Climate Change Vulnerability Index (CCVI) tool. Here we selected 73plant species found in Illinois and calculated their relative vulnerabilities to predicted climate changes, also using the NatureServe CCVI tool. We selected species from several groups that we felt would be broadly representative of the Illinois flora. These groups included: rare plants, invasive plants, important prairie species, important woodland/savanna species, important forest species, and plants important to society. We compiled and entered data regarding both the species’ exposures to predicted climate changes and their sensitivities to those changes. Exposures were determined by overlapping species range maps for Illinois with maps of temperature and moisture (AET:PET) predictions for the middle of this century. Species sensitivities were determined by interviewing between 4 and 12 experts for each plant species. Experts answered questions found in the CCVI tool regarding the species’ biologies, ecologies and behaviors. Results for each individual survey were averaged for each species. Results fell into one of five vulnerability categories: Extremely Vulnerable, Highly Vulnerable, Moderately Vulnerable, Not Vulnerable/Presumed Stable, and Not Vulnerable/Increase Likely. Results for these 73species in Illinois fell into all 5 vulnerability categories, with the majority (67%) falling into the Presumed Stable category. The species most vulnerable to predicted climate changes were all of conservation concern; most were federal or state listed species. Native species tended to be more vulnerable than non-natives, and plants important to prairies, savannas and forests were equally vulnerable to predicted changes. The four species were ranked as likely to increase in population size or range extent due to predicted climate changes were: Ailanthus altissima(tree of heaven), Ambrosia artemisiifolia(ragweed), Microstegium vimineum(Japanese stiltgrass) and Toxicodendron radicans(poison ivy). We advocate for 8 important next-steps to ensure adequate conservation of Illinois plants in a future with climate change, based on the findings of this report: 1) Investigate the climate change vulnerabilities of all rare plants in Illinois. Rare plants are the most vulnerable group of species in this report. 2) Prioritize research on plants’ abilities to phenologically track changes in seasonality, population genetics, species interactions, dispersal distances, thermal and hydrological tolerancesand soil preferences/tolerances. 3) Continue to monitor population trends. Increase capacity to monitor species with the most uncertain responses to climate changes, the most vulnerable species, and all rare species. 4) Monitor invasive speciesfor changes in populations and behavior. Assess all invasive species using NatureServe’s CCVI tool or another tool. 5) Increase connectivity between natural areas. Increase acreage of natural areas. 6) Managers, policymakers, researchers and the public shouldwork together to fully consider the role that assisted migration should or should not play in Illinois plant conservation. 7) Compile work done by various agencies and NGOs on the climate change vulnerabilities of Illinois species and ecosystems to detect trends, and to identify appropriate research, management and policy priorities. 8) Use adaptive management approaches to care for natural areas in Illinois in order to best achieve land management goals in an uncertain future.Illinois Natural History SurveyIllinois Department of Natural ResourcesIllinois Department of Transportationunpublishednot peer reviewedOpe

    Situación patológica de las hortalizas cultivadas en el oriente antioqueño.

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    Se indican los principales problemas fitopatológicos de las hortalizas en el Oriente Antioqueño, con énfasis en los cultivos de tomate, zanahoria, repollo, pimentón, remolacha, lechuga, cebolla de rama y coliflor. En relación con el tomate se mencionan los hongos Phytophthora infestans, Phoma andina, Xanthomonas campestris, Pseudomonas solanacearum, Alternaria solani y Botrytis cinerea principalmente. La zanahoria es atacada por los siguientes patógenos: Cercospora carotae, Alternaria dauci, el nematodo Meloidogyne spp. y por los hongos Rosellinia, Sclerotium rolfsii y Pythium. En el repollo se presenta ataque de Xanthomonas campestris, Mycosphaerela brassicola y Alternaria brassicae. En pimentón Alternaria solani, Cercospora capsci y Brotrytis cinerea. En las demás hortalizas prevalecen los hongos Cercospora beticola en remolacha, Sclerotinia sclerotiorum en lechuga y Alternaria porri y Peronospara destructor en ceboll

    Joint genomic prediction of canine hip dysplasia in UK and US Labrador Retrievers

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    Canine hip dysplasia, a debilitating orthopedic disorder that leads to osteoarthritis and cartilage degeneration, is common in several large-sized dog breeds and shows moderate heritability suggesting that selection can reduce prevalence. Estimating genomic breeding values require large reference populations, which are expensive to genotype for development of genomic prediction tools. Combining datasets from different countries could be an option to help build larger reference datasets without incurring extra genotyping costs. Our objective was to evaluate genomic prediction based on a combination of UK and US datasets of genotyped dogs with records of Norberg angle scores, related to canine hip dysplasia. Prediction accuracies using a single population were 0.179 and 0.290 for 1,179 and 242 UK and US Labrador Retrievers, respectively. Prediction accuracies changed to 0.189 and 0.260, with an increased bias of genomic breeding values when using a joint training set (biased upwards for the US population and downwards for the UK population). Our results show that in this study of canine hip dysplasia, little or no benefit was gained from using a joint training set as compared to using a single population as training set. We attribute this to differences in the genetic background of the two populations as well as the small sample size of the US dataset

    Measuring impairments of functioning and health in patients with axial spondyloarthritis by using the ASAS Health Index and the Environmental Item Set : translation and cross-cultural adaptation into 15 languages

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    Introduction: The Assessments of SpondyloArthritis international society Health Index (ASAS HI) measures functioning and health in patients with spondyloarthritis (SpA) across 17 aspects of health and 9 environmental factors (EF). The objective was to translate and adapt the original English version of the ASAS HI, including the EF Item Set, cross-culturally into 15 languages. Methods: Translation and cross-cultural adaptation has been carried out following the forward-backward procedure. In the cognitive debriefing, 10 patients/country across a broad spectrum of sociodemographic background, were included. Results: The ASAS HI and the EF Item Set were translated into Arabic, Chinese, Croatian, Dutch, French, German, Greek, Hungarian, Italian, Korean, Portuguese, Russian, Spanish, Thai and Turkish. Some difficulties were experienced with translation of the contextual factors indicating that these concepts may be more culturally-dependent. A total of 215 patients with axial SpA across 23 countries (62.3% men, mean (SD) age 42.4 (13.9) years) participated in the field test. Cognitive debriefing showed that items of the ASAS HI and EF Item Set are clear, relevant and comprehensive. All versions were accepted with minor modifications with respect to item wording and response option. The wording of three items had to be adapted to improve clarity. As a result of cognitive debriefing, a new response option 'not applicable' was added to two items of the ASAS HI to improve appropriateness. Discussion: This study showed that the items of the ASAS HI including the EFs were readily adaptable throughout all countries, indicating that the concepts covered were comprehensive, clear and meaningful in different cultures

    Effect of pruning on fruit quality of Vitis vinifera L. Sauvignon Blanc During maturation

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    La producción y calidad de la uva para elaboración de vino, se modifican con las prácticas culturales que se realizan en el viñedo. La poda es una de las prácticas que buscan mejorar la calidad final de mostos y vinos.Con la investigación se buscó conocer el efecto de tres tipos de poda (corta, larga y mixta) en la evolución de los componentes de la calidad, durante la maduración de frutos de Vitis vinifera L. var. Sauvignon Blanc, en el municipio de Sutamarchán-Boyacá, Colombia. Se recolectaron, cada quince días, aleatoriamente 20 bayas, desde el inicio del envero, hasta la maduración, para determinar el comportamiento de los sólidos solubles totales (SST), acidez total titulable (ATT) e índice de madurez técnica (IMT). Con la poda larga se alcanzó el mayor contenido de azúcares (22,76ºBrix) y el más alto IMT (3,42), la acidez total titulable (ATT) disminuyó con el desarrollo del fruto, obteniéndose en el momento de la vendimia una acumulación de ácidos orgánicos de 6,88 g L-1. Los tratamientos no afectaron el contenido de SST; mas si hubo diferencias significativas entre ATT e IMT. La poda larga produjo los frutos con los valores más adecuados, de calidad (SST, ATT, IMT) requeridos para la elaboración de vinos tropicales de la variedad Sauvignon Blanc, en la localidad del estudio

    Altered expression and activation of signal transducers and activators of transcription (STATs) in hepatitis C virus infection: in vivo and in vitro studies

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    BACKGROUND: Signal transducers and activators of transcription (STATs) play a critical role in antiviral defence. STAT3 is also important in cell protection against inflammatory damage. STAT proteins are activated by interferons and by hepatoprotective cytokines of the interleukin 6 superfamily, including cardiotrophin 1. METHODS: We analysed the status of STATs in hepatitis C virus (HCV) infected livers and the relationship between expression and activation of STATs and HCV replication in Huh7 cells transfected with HCV genomic replicon. RESULTS: STAT3alpha expression was reduced in HCV infected livers showing an inverse correlation with serum alanine aminotransferase. In patients with HCV infection, nuclear staining for phosphorylated STAT3 was faint in parenchymal cells (although conspicuous in infiltrating leucocytes), in contrast with strong nuclear staining in hepatocytes from control livers. Expression and activation of STAT1 (a factor activated by both interferon (IFN)-alpha and IFN-gamma) were increased in HCV infected livers, particularly in those with high inflammatory activity. Conversely, phosphorylated STAT2 (a factor selectively activated by IFN-alpha) was undetectable in livers with HCV infection, a finding that was associated with marked downregulation of the two functional subunits of the IFN-alpha receptor. HCV replication in Huh7 cells caused STAT3alpha downregulation and blocked STAT3 phosphorylation by either IFN-alpha or cardiotrophin 1. HCV replication in Huh7 cells also inhibited STAT1 and STAT2 activation by IFN-alpha while there was no impairment of STAT1 phosphorylation by the proinflammatory cytokine IFN-gamma. CONCLUSIONS: STAT3 is downregulated in HCV infected livers and in Huh7 cells bearing the full length HCV replicon. HCV replication is associated with impaired Jak-STAT signalling by antiviral and cytoprotective cytokines. These effects may favour viral replication while facilitating the progression of liver diseas
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