2,792 research outputs found

    Didactic strategies for comprehension and learning of structural concepts

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    p. 926-937In previous papers we have established the convenience of formulating educational strategies at the university level for both disciplines: Civil Engineering and Architecture, which involves academic topics of mutual interest by means of shared practices. As a particular matter of this approach, the application of physical experimental models is considered of special usefulness, in order to understand in better ways the performance of materials and structural systems. Several strategies of selection and development of such physical models will be discussed in this work, considering as a first step, the establishment of its correspondence with the different levels of structural complexity studied in curriculum plan: statics, strength of materials and structural design, among others. This task constitutes a part of the work program of the Laboratory of Structural Models, which is an academic project that develops and applies different didactic prototypes to structure courses in the Universidad Autónoma Metropolitana, campus Azcapotzalco, in Mexico City, project we have already presented in recent forums. Two different modes of application are implemented in classroom sessions and in structures workshop: the devices for functional demonstration of typical cases of structural work as well as the experimentation with student's own designs of destructible models where certain typologies are tested up to its failure limit. The first one allows teachers to explain adequately the theoretical principles and formulas (that usually are expressed on the blackboard) by means of didactic models identified in accordance to specific cases of the curriculum on variable level of complexity. This kind of practice allows the students of architecture and civil engineering to realize in better ways the possibilities of use and application of the different structural typologies. Such experimental models are part of more than fifty devices of the Laboratory's catalog. In the same sense, the possibility of observation of structural work of their own architectural designs, allows future professionals to achieve a better conception of the structural solutions that affect positively their designs. Based on specific predefined guides, the students develop their own architectural-structural projects and subject them to diverse loads, observing their behavior under the influence of variable stresses leading up the experiment to its last resistance. From both experiences a significant learning is obtained for the student's formation and training, who will be capable in his future professional work to use better tools of comprehension of the structural concepts applied to architecture as well as of increasing his conscience of the benefits and convenience of multidisciplinary work.Moreno, C.; Abad, A.; Gerdingh, JG.; Garcia M., C.; Gonzalez C., O. (2010). Didactic strategies for comprehension and learning of structural concepts. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

    Drugs, Motivation and Prevention Campaigns in Spain (1994-2007). Story of a Misunderstanding

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    The aim of this article is to analyze and frame the level of efficacy and adequacy of publicity campaigns for the prevention of drug use in Spain To this end the contents of the messages used by the FAD Antidrug Foundation in television campaigns broadcast between 1994 and 2007 have been reviewed The content of these campaigns has also been linked to the progress and motivation of drug users using the biannual surveys of the Ministry for Equality and Social Welfare The results show that the discourse followed in these campaigns has no relation whatsoever with the said motivations linked with drug abuse Consequently a strategy is required which will have an impact on discouraging and dissuading drug user

    Morphology Dependent Distributed Controller for Locomotion in Modular Robots

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    Stigmergy is defined as a mechanism of coordination through indirect communication among agents, which can be commonly observed in social insects such as ants. In this work we investigate the emergence of coordination for locomotion in modular robots through indirect communication among modules. We demonstrate how intra-configuration forces that exist between physically connected modules can be used for self-organization in modular robots, and how the emerging global behavior is a result of the morphology of the robotic configuration

    Ectopic application of the repressive histone modification H3K9me2 establishes post-zygotic reproductive isolation in Arabidopsis thaliana

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    Hybrid seed lethality as a consequence of interspecies or interploidy hybridizations is a major mechanism of reproductive isolation in plants. This mechanism is manifested in the endosperm, a dosage-sensitive tissue supporting embryo growth. Deregulated expression of imprinted genes such as ADMETOS (ADM) underpin the interploidy hybridization barrier in Arabidopsis thaliana; however, the mechanisms of their action remained unknown. In this study, we show that ADM interacts with the AT hook domain protein AHL10 and the SET domain-containing SU (VAR) 3-9 homolog SUVH9 and ectopically recruits the heterochromatic mark H3K9me2 to AT-rich transposable elements (TEs), causing deregulated expression of neighboring genes. Several hybrid incompatibility genes identified in Drosophila encode for dosage-sensitive heterochromatin-interacting proteins, which has led to the suggestion that hybrid incompatibilities evolve as a consequence of interspecies divergence of selfish DNA elements and their regulation. Our data show that imbalance of dosage-sensitive chromatin regulators underpins the barrier to interploidy hybridization in Arabidopsis, suggesting that reproductive isolation as a consequence of epigenetic regulation of TEs is a conserved feature in animals and plants

    Gas phase selective hydrogenation of furfural to furfuryl alcohol and 2-methylfuran over Cu-CeO2 coprecipitated catalysts

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    Furfural is an important chemical derived from lignocellulosic biomass, in particular from C5 sugars like xylose, and it is considered as a platform molecule of great potential for the synthesis of a broad spectrum of chemicals. In this sense, furfuryl alcohol and 2-methylfuran are two important chemicals which can be produced through furfural hydrogenation, either in liquid or vapor phase, although the latter is preferred because it can be carried out at atmospheric pressure. Industrially, a copper chromite catalyst is used, although this catalyst can become very toxic due to the presence of chromium. Therefore, much attention is being paid to the development of chromium-free catalysts, more sustainable and environmentally friendly, as those based on Cu or Ni which are active and selective towards the formation of furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is mainly used for the production of thermostatic resins, intermediate in the manufacture of lysine, vitamin C and dispersing agents. Meanwhile, 2-methyl furan is used in the synthesis of pesticides, or in the pharmaceutical and fragrance industries. The aim of this work is the synthesis of a series of copper based catalysts, which have been synthesized by coprecipitation of copper and cerium(IV) and subsequent thermal programmed reduction. This method allows increasing the dispersion of Cu particles, while the use of a support like CeO2 can modify the electronic density of the active phase, which can influence the catalytic activity and resistance to deactivation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Economy and Competitiveness Ministry (Project CTQ2012-38204-C03-02), Junta de Andalucía (Project: RNM-1565) and FEDER funds of the European Unio

    A polytrauma patient with an unusual posterior fracture-dislocation of the femoral head: a case report

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    We report a case of a 27-year-old man who was involved in a high-speed car accident. He sustained multiple organ damage including multiple brain petechiae suggesting diffuse axonal damage, aortic dissection, retroperitoneal haematoma and a fracture-dislocation of the right hip with a femoral head fracture and an ipsilateral intertrochanteric fracture. Due to the general condition of the patient, physiological stabilisation was prioritized, and at 2 weeks the fracture-dislocation of the hip was treated with a proximal femoral nail for the intertrochanteric fracture and Herbert screws for the femoral head fracture. Postoperatively, two episodes of recurrent hip dislocation occurred, and this was stabilized eventually with a Steinman pin inserted across the hip joint and taken out 1 month later. Weight-bearing was allowed according to clinical and radiographical assessments. Heterotopic ossification developed around the hip joint, but without evidence of AVN or osteoarthritis. At 18-months follow-up, the fractures had healed and the patient had a Harris Hip score of 79.1. Anatomical reduction and stable fixation of fracture-dislocations of the hip are important for achieving an acceptable result

    Mesoporous niobium oxide for dehydration of D-xylose into furfural

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    Se ha demostrado que el óxido de niobio mesoporoso es un catalizador eficaz para la deshidratación de D-xilosa a furfural, alcanzando una conversión del 92% y un rendimiento de furfural 49,3% a 170º C y 90 minutos. La lixiviación de Nb, determinada por ICP-MS, era inferior al 0,5% en peso de la concentración de Nb inicial, confirmando de este modo la estabilidad del catalizador ácido sólido.El furfural posee un gran potencial como molécula plataforma de origen renovable para la síntesis de una alta variedad de compuestos químicos. Se obtiene mediante la deshidratación de pentosas, principalmente a partir de D-xilosa, proceso catalizado por ácidos minerales en fase homogénea. Por tanto, dentro de la química verde y la búsqueda de sostenibilidad de los procesos catalíticos, es necesaria su sustitución por catalizadores sólidos ácidos que sean tolerantes al agua, ya que es el disolvente más utilizado para esta reacción. El óxido de niobio posee propiedades ácidas y es insoluble en agua, pero su superficie específica es muy baja. Por lo tanto, resulta muy interesante la síntesis de un óxido de niobio mesoporoso para emplearlo como catalizador en esta reacción. En este trabajo, se ha sintetizado un Nb2O5 mesoporoso y se ha evaluado su comportamiento catalítico en la obtención de furfural a partir de D-xilosa.Spanish Ministry of Science and Innovation (ENE2009-12743-C04-03 project)Junta de Andalucía (P09-FQM-5070).Ministry of Science and Innovation for the financial support under the Program Ramón y Cajal (RYC-2008-03387)

    Factors associated with mental health outcomes after COVID-19: a 24-month longitudinal follow-up study

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    Objetivo: Investigar la proporción de resultados de salud mental (MHO) y los factores asociados en los supervivientes del COVID-19 durante un periodo de seguimiento de 24 meses. Método: Se realizó un estudio observacional, prospectivo en un hospital universitario de Barranquilla, Colombia, desde el 1 de abril de 2020 hasta el 30 de agosto de 2022. Se reclutó una cohorte de 1565 sobrevivientes de COVID-19 después del alta de los servicios de urgencias (SU), piso de hospitalización (FI) y unidad de cuidados intensivos (UCI) y se les hizo seguimiento durante 24 -meses. La evaluación clínica incluyó escalas de detección de síntomas de ansiedad, depresión, trastorno de estrés postraumático (TEPT) e insomnio. También se recogieron factores sociodemográficos y clínicos para identificar posibles factores asociados. Se realizaron modelos descriptivos, bivariantes y lineales mixtos de efectos aleatorios. Resultados: Se incluyeron un total de 1565 pacientes, de los cuales 785 (50,35%) eran hombres. Se identificó una gran proporción de pacientes con síntomas mentales. Después de 24 meses, las proporciones de síntomas de ansiedad, depresión, TEPT e insomnio seguían siendo elevadas: 16,55%, 21,79%, 35,27% y 23,86%, respectivamente. Los factores sociales, la localización de las estancias hospitalarias, las comorbilidades físicas y la gravedad del COVID-19 se asociaron significativamente con los síntomas de ansiedad, depresión, TEPT e insomnio. Conclusiones: Se han documentado los efectos nocivos de la COVID-19 sobre la salud mental durante 2 años, así como las variables que influyen en estos resultados. Estos resultados deberían ayudar en el desarrollo de iniciativas de salud pública para reducir las tasas de morbilidad en pacientes post-COVID-19. 2023 Los autores.Objective: Investigate the proportion of mental health outcomes (MHOs) and associated factors in COVID-19 survivors during a 24-month follow-up period. Method: An observational, prospective study was performed in a teaching hospital in Barranquilla, Colombia, from April 1, 2020, to August 30, 2022. A cohort of 1565 COVID-19 survivors was recruited after discharge from the emergency room (ER), inpatient floor (IF), and intensive care unit (ICU) services and followed for 24 -months. The clinical assessment included screening scales for symptoms of anxiety, depressive, post-traumatic stress disorder (PTSD), and insomnia. Sociodemographic and clinical factors were also collected to identify possible associated factors. Descriptive, bivariate and mixed random-effect linear models were performed. Results: A total of 1565 patients were included, of whom 785 (50.35%) were men. A large proportion of patients with mental symptoms were identified. After 24-months, the proportions of anxiety, depression, PTSD, and insomnia symptoms remained high at 16.55%, 21.79%, 35.27%, and 23.86%, respectively. Social factors, location of hospital stays, physical comorbidities, and the severity of COVID-19 were significantly associated with anxiety, depression, PTSD, and insomnia symptoms. Conclusions: COVID-19's 2-year deleterious impacts on mental health, as well as the variables influencing these findings, have been documented. These results should aid in the development of public health initiatives to reduce morbidity rates in post-COVID-19 patients. © 2023 The Authors
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