45 research outputs found

    Incidencia de las pantallas del celular, el videojuego y la tv en la dinámica de la generación interactiva venezolana

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    Mediante un Análisis multivariante complejo se analizan las pautas de consumo, uso y valoración propia de niños y adolescentes en lo concerniente a las pantallas del celular, la televisión y el videojuego durante el año 2008. Se responden preguntas relacionadas con la realidad experimentada al respecto por los menores venezolanos. Se analiza la relación que mantienen con las referidas pantallas los niños y adolescentes de edades comprendidas entre 6 y 18 años que viven en este país. Se concluye que la televisión es la pantalla con mayor penetración en los hogares de los niños venezolanos. Vale también destacar que, cualquier otra actividad que tengan que hacer los adolescentes, la combinan con la televisión, ésta les acompaña, aunque sea como sonido de fondo.------------------------------Based on a multivariable analysis, this article analyses the consume trends, uses and value of children and teens between 6 and 18 years old with regards to the mobile phone screens, television and videogames in 2008 in Venezuela. Television seems to be still the medium with highest penetrations among households. The study also found that most of the other media consumptions activities are performed in relation with television, even if it is just as background sound

    Progress in the taxonomy of Late Cretaceous high-latitude radiolarians: insights from the Horton River area, Northwest Territories, Canada

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    Radiolarians have proven to be exceptional tools in biostratigraphic and paleoenvironmental studies despite their relatively low preservation potential in the sedimentary record. Reports of Upper Cretaceous radiolarians in high northern latitudes are scant, and their taxonomy is not often discussed in the few reports available in the literature. In this study, we describe one new genus and three new species of polycystine radiolarians from Upper Cretaceous strata of the northern mainland coast of Arctic Canada. The specimens were recovered from the Santonian–middle Campanian Smoking Hills Formation and the middle Campanian–Maastrichtian Mason River Formation and are assigned to the genus Canadasphaera n. gen. (Order Spumellaria) and the species Canadasphaera inuita n. sp., Kuppelella rusti n. sp., and Lithocampe? rara n. sp. The taxonomic notes provided in this study improve our understanding of Late Cretaceous radiolarians from high northern latitudes and serve as a foundation for future Cretaceous radiolarian research in Arctic regions. Canadasphaera: urn:lsid:zoobank.org:act:C6B7B702-4B74-472D-8893-0A41B93A5066, date of registration: 19 April 2024 Canadasphaera inuita: urn:lsid:zoobank.org:act:C30E555B-EE94-4680-87D1-5CE83E128461, date of registration: 19 April 2024 Kuppelella rusti: urn:lsid:zoobank.org:act:68ECB628-2E74-4748-ACA4-DD1A33B05837, date of registration: 19 April 2024 Lithocampe? rara: urn:lsid:zoobank.org:act:25E569B2-93A8-425F-BB7C-D29A0437763F, date of registration: 19 April 2024</ul

    Catalytic activity and accessibility of acidic ion-exchange resins in liquid phase etherification reactions

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    Abstract Although macroreticular acidic ion-exchange resins have been widely used as catalysts in the industrial world for decades, their catalytic behavior is still far from being completely understood at a molecular level. Several characterization techniques coexist, which provide information about their properties. Only few of these techniques give an actual picture of their working-state features when swollen in anhydrous polar reactive media such as in etherification processes, where they are extensively used. The inverse steric exclusion chromatography technique, based on modeling the micropores structure, or gel-phase, as a set of discrete volume fractions with a characteristic polymer chain density, constitutes an appropriate procedure to assess the morphology of ion-exchangers in the swollen state. Present work proposes an empirical model to correlate the properties of the volume fractions with their catalytic activity in the etherification reaction rates of isobutene by addition of C1 to C4 linear primary alcohols. Sixteen different macroreticular acidic ion-exchange catalysts, both commercial and lab-made, have been used, which differ in acid capacity, sulfonation type, cross-linking degree and swollen-phase volume fractions distribution. Experimental reaction rates have been expressed as a sum of contributions of each individual volume fraction. The contribution of each polymer volume fraction corresponds to the product of the catalyst acidity, the characteristic volume fraction within the gel-phase of the catalyst, and a specific turnover frequency (TOF) of that fraction. Accessibility of the reacting alcohol, expressed in terms of the Ogston coefficient, has been also included in the empirical dependency equation presented in this work

    Identification of loci associated with pathological outcomes in Holstein cattle infected with Mycobacterium avium subsp. paratuberculosis using whole-genome sequence data

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    [EN]Bovine paratuberculosis (PTB), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic granulomatous enteritis that affects cattle worldwide. According to their severity and extension, PTB-associated histological lesions have been classified into the following groups; focal, multifocal, and diffuse. It is unknown whether these lesions represent sequential stages or divergent outcomes. In the current study, the associations between host genetic and pathology were explored by genotyping 813 Spanish Holstein cows with no visible lesions (N = 373) and with focal (N = 371), multifocal (N = 33), and diffuse (N = 33) lesions in gut tissues and regional lymph nodes. DNA from peripheral blood samples of these animals was genotyped with the bovine EuroG MD Bead Chip, and the corresponding genotypes were imputed to whole-genome sequencing (WGS) data using the 1000 Bull genomes reference population. A genome-wide association study (GWAS) was performed using the WGS data and the presence or absence of each type of histological lesion in a case-control approach. A total of 192 and 92 single nucleotide polymorphisms (SNPs) defining 13 and 9 distinct quantitative trait loci (QTLs) were highly-associated (P <= 5 x 10(-7)) with the multifocal (heritability = 0.075) and the diffuse (heritability = 0.189) lesions, respectively. No overlap was seen in the SNPs controlling these distinct pathological outcomes. The identified QTLs overlapped with some QTLs previously associated with PTB susceptibility, bovine tuberculosis susceptibility, clinical mastitis, somatic cell score, bovine respiratory disease susceptibility, tick resistance, IgG level, and length of productive life. Pathway analysis with candidate genes overlapping the identified QTLs revealed a significant enrichment of the keratinization pathway and cholesterol metabolism in the animals with multifocal and diffuse lesions, respectively. To test whether the enrichment of SNP variants in candidate genes involved in the cholesterol metabolism was associated with the diffuse lesions; the levels of total cholesterol were measured in plasma samples of cattle with focal, multifocal, or diffuse lesions or with no visible lesions. Our results showed reduced levels of plasma cholesterol in cattle with diffuse lesions. Taken together, our findings suggested that the variation in MAP-associated pathological outcomes might be, in part, genetically determined and indicative of distinct host responses.Financial support for this study was provided by a Grant from the Spanish Ministry of Science, Innovation, and Universities (RTI2018-094192-R-C21) and by European Regional Development Funds (FEDER) to MAH. MC and GBB have been awarded fellowships from the National Institute for Agricultural Research (INIA) and the Spanish Ministry of Science, Innovation and Universities programs, respectively. This work has been possible thanks to the support of the computing infrastructure of the i2BASQUE Research and Academic Network. We gratefully acknowledge the Bull Genomes Consortium for providing accessibility to the WGS data that was used in this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Identification of loci associated with susceptibility to Mycobacterium avium subsp. paratuberculosis infection in Holstein cattle using combinations of diagnostic tests and imputed whole-genome sequence data

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    Bovine paratuberculosis (PTB) is a chronic inflammatory disease caused by Mycobacterium avium susbp. paratuberculosis (MAP). Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) significantly associated with susceptibility to bovine PTB. The main objective of this study was to identify quantitative trait loci (QTLs) associated with MAP infection in Spanish Holstein cows (N = 983) using combinations of diagnostic tests and imputed whole-genome sequence (WGS) data. The infection status of these animals was defined by three diagnostic methods including ELISA for MAP-antibodies detection, and tissue culture and PCR for MAP detection. The 983 cows included in this study were genotyped with the Bovine MD SNP50 Bead Chip, and the corresponding genotypes were imputed to WGS using the 1,000 Bull genomes reference population. In total, 33.77 million SNP variants per animal were identified across the genome. Linear mixed models were used to calculate the heritability (h2) estimates for each diagnostic test and test combinations. Next, we performed a case-control GWAS using the imputed WGS datasets and the phenotypes and combinations of phenotypes with h2 estimates > 0.080. After performing the GWAS, the test combinations that showed SNPs with a significant association (PFDR ≤ 0.05), were the ELISA-tissue PCR-tissue culture, ELISA-tissue culture, and ELISA-tissue PCR. A total of twelve quantitative trait loci (QTLs) highly associated with MAP infection status were identified on the Bos taurus autosomes (BTA) 4, BTA5, BTA11, BTA12, BTA14, BTA23, BTA24, and BTA28, and some of these QTLs were linked to immune-modulating genes. The identified QTLs on BTA23 spanning from 18.81 to 22.95 Mb of the Bos taurus genome overlapped with several QTLs previously found to be associated with PTB susceptibility, bovine tuberculosis susceptibility, and clinical mastitis. The results from this study provide more clues regarding the molecular mechanisms underlying susceptibility to PTB infection in cattle and might be used to develop national genetic evaluations for PTB in Spain.Financial support for this study was provided by a grant from the Spanish Ministry of Science, Innovation, and Universities (MICINN, project code: RTI2018-094192-R-C21) and by European Regional Development Funds (FEDER) to MAH. MC and GBB have been awarded fellowships from the National Institute for Agricultural Research (INIA) and MICINN, respectivel

    Juventud y emprendimiento: ¿de qué hablamos cuando hablamos de juventud capaz de emprender? El caso de Navarra

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    Si no existe un buen “ecosistema emprendedor”, resulta difícil que los deseos de recuperación económica por la vía del emprendimiento se conviertan en realidad. La situación española es, a este respecto, bastante desalentadora. Los indicadores de emprendimiento respecto a otros países demuestran que hay un largo recorrido de mejora. En ese camino entran en juego diversas variables, como la fiscalidad del país, las trabas a la hora de abrir negocios, los costes, etc. Sin embargo, hay otro factor fundamental para tener ciudadanos con espíritu emprendedor: la educación. Los problemas de emprendimiento pueden atribuirse en buena medida a la falta de la formación en el carácter emprendedor en las aulas desde una edad temprana. Pero ¿cómo inculcar las competencias emprendedoras en estudiantes adultos si nunca antes se ha trabajado en esas áreas? Este artículo intenta clarificar algunas cuestiones que pueden dificultar la comprensión de las competencias de emprendimiento y su puesta en práctica. Se explica, en primer lugar, la importancia de la formación en competencias y, concretamente, en la competencia de emprender. A continuación, se exponen los resultados de un estudio reciente de Institución Futuro que define de forma práctica la importancia y realidad de las competencias necesarias para emprender, tanto desde el punto de vista de los jóvenes universitarios, como el de profesionales y empresas. Por último, se establecen algunas conclusiones y recomendaciones
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