510 research outputs found

    The Moral Herd: Groups and the Evolution of Altruism and Cooperation

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    Bergh, J.C.J.M. van den [Promotor]Veelen, C.M. van [Copromotor

    Selective oxidation of alkyl and aryl glyceryl monoethers catalysed by an engineered and immobilised glycerol dehydrogenase

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    Enzymes acting over glyceryl ethers are scarce in living cells, and consequently biocatalytic transformations of these molecules are rare despite their interest for industrial chemistry. In this work, we have engineered and immobilised a glycerol dehydrogenase from Bacillus stearothermophilus (BsGlyDH) to accept a battery of alkyl/aryl glyceryl monoethers and catalyse their enantioselective oxidation to yield the corresponding 3-alkoxy/aryloxy-1-hydroxyacetones. QM/MM computational studies decipher the key role of D123 in the oxidation catalytic mechanism, and reveal that this enzyme is highly enantioselective towards S-isomers (ee > 99%). Through structure-guided site-selective mutagenesis, we find that the mutation L252A sculpts the active site to accommodate a productive configuration of 3-monoalkyl glycerols. This mutation enhances the kcat 163-fold towards 3-ethoxypropan-1, 2-diol, resulting in a specific activity similar to the one found for the wild-type towards glycerol. Furthermore, we immobilised the L252A variant to intensify the process, demonstrating the reusability and increasing the operational stability of the resulting heterogeneous biocatalyst. Finally, we manage to integrate this immobilised enzyme into a one-pot chemoenzymatic process to convert glycidol and ethanol into 3-ethoxy-1-hydroxyacetone and (R)-3-ethoxypropan-1, 2-diol, without affecting the oxidation activity. These results thus expand the uses of engineered glycerol dehydrogenases in applied biocatalysis for the kinetic resolution of glycerol ethers and the manufacturing of substituted hydroxyacetones. This journal i

    Estimating the Relationship between Reading in Primary Education, Educational Attainment and Social Welfare. The Case of Extremadura (Spain)

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    The purpose of this paper is to analyse the relationship between the Social Welfare Index and the reading habits of primary school students in Extremadura (Spain). A study has been performed which consists of two parts. First, we conducted 4,288 surveys on reading habits in 87 municipalities. Second, we calculated the social welfare index. The statistical analysis refl ects two conclusions: firstly, educational and socio-economic policies have resulted in equal opportunities that allow for similar social possibilities throughout the territory; secondly, Educational Attainment of parents is the most decisive factor in obtaining the best results in terms of students' reading habits

    A Methodological Approach for Testing the Viability of Seeds Stored in Short-Term Seed Banks

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    [EN] Efficient management of `active¿ seed banks ¿ specifically aimed at the short-term storage at room temperature of seeds to be used locally in conservation/regeneration programmes of endemic or endangered plant species ¿ requires establishing the optimal storage time to maintain high seed viability, for each stored species. In this work, germination of seeds of the halophytes Thalictrum maritimum, Centaurea dracunculifolia and Linum maritimum has been investigated. The seeds had been stored for different periods of time in the seed bank of `La Albufera¿ Natural Park (Valencia, SE Spain) after collection in salt marshes of the Park, where small populations of the three species are present. Seeds of T. maritimum and C. dracunculifolia have a relatively short period of viability at room temperature, and should not be stored for more than three years. On the other hand, L. maritimum seeds maintain a high germination percentage and can be kept at room temperature for up to 10 years. T. maritimum seeds, in contrast to those of the other two species, did not germinate in in vitro tests nor when sown directly on a standard substrate, unless a pre-treatment of the seeds was applied, mechanical scarification being the most effective. These results will help to improve the management of the seed bank, to generate more efficiently new plants for reintroduction and reinforcement of populations of these species in their natural ecosystems within the Natural ParkForte Gil, J.; Yabor, L.; Bellido Nadal, A.; Collado Cerveró, F.; Ferrer-Gallego, P.; Vicente, O.; Boscaiu, M. (2017). A Methodological Approach for Testing the Viability of Seeds Stored in Short-Term Seed Banks. Notulae Scientia Biologicae. 9(4):563-570. doi:10.15835/nsb9410173S5635709

    A Simple Method to Check the Reliability of Annual Sunspot Number in the Historical Period 1610-1847

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    A simple method to detect inconsistencies in low annual sunspot numbers based on the relationship between these values and the annual number of active days is described. The analysis allowed for the detection of problems in the annual sunspot number series clustered in a few specific periods and unambiguous, namely: i) before Maunder minimum, ii) the year 1652 during the Maunder minimum, iii) the year 1741 in Solar Cycle -1, and iv) the so-called "lost" solar cycle in 1790s and subsequent onset of the Dalton Minimum.Comment: 15 pages, 3 figures, to be published in Solar Physic

    17. EL APRENDIZAJE INTEGRAL A TRAVÉS DE LA STEM, REFLEXIONES SOBRE SU APLICACIÓN EN LA EDUCACIÓN EN LAS INSTITUCIONES EDUCATIVAS EN MEDELLÍN

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    Medellín reconocida como la ciudad innovadora del mundo y epicentro de la cuarta revo­lución industrial, tiene un reto y un compromiso con estos dos momentos, modernizar la educación apor­tando al desarrollo de habilidades de pensamiento enfocados a la ciencia y la tecnología, y promover en todos los entornos habilidades para la vida. Uno de los desafíos más importantes en la educación es el desarrollo de una formación integral, lograr que los estudiantes y maestros, apropien disciplinas que necesitan para un desarrollo más sistémico en lo profesional. STEM por sus siglas en ingles Science, Technology, Engineering and Mathematics, es una metodología que posiblemente se ha aplicado en el entorno local, sin darle la connotación que tiene, considerada necesaria para el eficiente desarrollo de los profesionales del futuro. Las disciplinas que se agrupan en esta metodología permiten integrar habilidades duras y blandas en un solo ejercicio, buscando desarrollar competencias necesarias para responder a las actuales necesidades del mercado. El objetivo de esta propuesta de reflexión es realizar una revisión sobre la aplicación de la metodología STEM en la educación en Medellín, aplicando la metodología sistemática para hacer el rastreo y la revisión bibliográfica

    Schistosomus reflexus en un felino: reporte de caso

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    The case of a 5-year-old crossbred female cat in her first gestation was presented for consultation. The cat had a stillborn present in the birth canal, which was extracted manually. A second puppy is expelled alive but was euthanized because of her clinical infeasibility. The two puppies presented a malformation in the abdominal region with exposure of some viscera, considered as Schistosomus reflexus syndrome. The radiological and necropsy diagnostic evaluation of the second puppy was performed, finding a closure defect of the abdominal midline with viscera exposure (small intestine, liver, right kidney and spleen among others). The radiological evaluation showed the eventration of abdominal organs without clear differentiation between them, kyphosis in the thoracolumbar segment, lordosis in the lumbar portion and oligodactyly in the right posterior limb.Se presenta el caso de una hembra felina de raza mestiza de 5 años en su primer parto llevada a consulta. La gata tenía un mortinato presente en el canal de parto el cual se extrae manualmente. Un segundo cachorro es expulsado vivo, pero por su la inviabilidad clínica se procedió a la eutanasia. Las dos crías presentaron una malformación en la región abdominal con exposición de algunas vísceras, considerada como el síndrome de Schistosomus reflexus. Se realizó la evaluación diagnóstica radiológica y por necropsia del segundo cachorro encontrando un defecto de cierre de la línea media abdominal con exposición de vísceras (intestino delgado, hígado, riñón derecho y bazo entre otros). En la evaluación radiológica se evidenció eventración de órganos abdominales sin diferenciación clara entre ellos, cifosis en el segmento toracolumbar, lordosis en la porción lumbar y oligodactilia en el miembro posterior derecho
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