447 research outputs found

    La percepción que los corredores kenianos tienen de sus actividades de entrenamiento

    Get PDF
    El presente estudio se enmarca dentro de la Teoría del Rendimiento Experto. Esta teoría propone que para llegar a ser experto en un dominio, un sujeto debe superar un periodo de adquisición extensivo consistente en miles de horas de práctica intencionalmente diseñada para mejorar. El presente estudio buscó analizar las percepciones subjetivas de un grupo de corredores kenianos de larga distancia sobre sus tareas de entrenamiento para lo cual cumplimentaron un cuestionario basado en una taxonomía de actividades de entrenamiento valoradas en cuatro dimensiones: Relevancia, Esfuerzo, Concentración y Diversión. En este estudio participaron 27 corredores de fondo kenianos divididos en tres grupos de niveles por su marca. El rango de edades de los participantes fue de 21 a 39 años (M= 25,39; DT= 3,82). Todos estos corredores eran especialistas de las pruebas de media maratón y maratón. Fueron divididos en tres grupos de nivel de rendimiento por su marca: Medio, Alto y Muy Alto. Los resultados mostraron como las dimensiones de Concentración, Esfuerzo y Disfrute diferenciaron a los corredores por su nivel, asímismo se manifestó el papel que las actividades grupales de entrenamiento tienen para estos corredores, lo que plantea la cuestiòn si los modelos de desarrollo de la excelencia desarrollados en en los paises desarrollados sirven para explicar este fenómeno en los países en vías de desarrollo

    Caracterización de las propiedades de durabilidad y resistencia a compresión de lechadas de cemento con escoria de alto horno para trabajos geotécnicos especiales

    Get PDF
    Special foundations, most prominently micropiles and soil anchors, are frequently used in construction today. In Spain, the grout for these special technical applications is generally prepared with portland cement, although the codes and standards in place stipulate only the minimum compressive strength required, with no mention of cement type. Those texts also establish a range of acceptable water:cement ratios. In the present study, durability and compressive strength in cement grout prepared with blast furnace slag cement at different w/c ratios are characterised and compared to the findings for a reference portland cement grout. The results show that slag grout exhibits greater durability than the portland cement material and complies with the compressive strength requirements laid down in the respective codes.Actualmente es muy frecuente el empleo de cimentaciones especiales, entre las que destacan los micropilotes y los anclajes. En España, las lechadas de cemento para estos trabajos geotécnicos especiales se preparan habitualmente con cemento Portland, aunque las diferentes normativas al respecto no restringen el tipo de cemento a emplear, siempre que se alcance una determinada resistencia a compresión. Respecto a la dosificación de las lechadas, la normativa permite emplear diferentes relaciones agua/cemento dentro de un determinado rango. En vista de ello, en este trabajo se han caracterizado las propiedades de durabilidad y resistencia a compresión de lechadas de cemento preparadas con un cemento con escoria de alto horno y con diferentes relaciones a/c, tomando como referencia de comportamiento lechadas de cemento Portland. El uso de un cemento con escoria conlleva una mejora en la durabilidad de las lechadas, cumpliendo los requisitos de resistencia a compresión establecidos por la normativa.This research was funded by the Spanish Ministry of Economy and Competitiveness (formerly by the Spanish Ministry of Science and Innovation) and FEDER through projects BIA2010-20548 and BIA2011-25721

    Long-term clinical and functional course of Borderline Personality Disorder: A meta-analysis of prospective studies

    Get PDF
    Background: This meta-analytic review is the first to synthesize findings from prospective research on the long-term course of borderline personality disorder in adult clinical populations. Methods: Systematic searches were conducted in Medline, PsycINFO, PsycArticles, PubMed, and Scopus within the period 1990-2017. Inclusion criteria were: (1) adult BPD sample diagnosed by a validated, semi-structured interview; (2) at least two prospective assessments of outcomes; and (3) follow-up period ≥ 5 years. Quality of evidence was rated with the Systematic Assessment of Quality in Observational Research (SAQOR). Four outcomes were meta-analysed using mixed-effect methods: remission from BPD diagnosis, completed suicide, depressive symptoms, and functioning. Potential moderators regarding the natural course and the initial treatment received were studied. Results: Eleven studies met the inclusion criteria, with 837 participants from nine countries being followed. Between 50% and 70% of the BPD patients achieved remission in the long-term. Significant reductions in depression and functional impairment were also found. Mean suicide rate ranged from 2% to 5%. Younger age was associated with a higher likelihood of remission. Being female was correlated with lower functional improvement. Despite some positive trends, there were no significant associations between treatment moderators and the long-term outcome. Conclusions: Findings suggest that the course of BPD is characterized by symptomatic amelioration and a slight functional improvement in the long-term. Age and gender modulate the long-term prognosis and should be considered to adapt treatment resources. Further research is required to draw robust conclusions on the long-term effects of psychotherapeutic interventions

    A Study on the Suitability of Visual Languages for Non-Expert Robot Programmers

    Get PDF
    A visual programming language allows users and developers to create programs by manipulating program elements graphically. Several studies have shown the bene ts of visual languages for learning purposes and their applicability to robot programming. However, at present, there are not enough comparative studies on the suitability of textual and visual languages for this purpose. In this paper, we study if, as with a textual language, the use of a visual language could also be suitable in the context of robot programming and, if so, what the main advantages of using a visual language would be. For our experiments, we selected a sample of 60 individuals among students with adequate knowledge of procedural programming, that was divided into three groups. For the rst group of 20 students, a learning scenario based on a textual objectoriented language was used for programming a speci c commercial robotic ball with sensing, wireless communication, and output capabilities, whereas for the second and the third group, two learning scenarios based on visual languages were used for programming the robot. After taking a course for programming the robot in the corresponding learning scenario, each group was evaluated by completing three programming exercises related to the robot features (i.e. motion, lighting, and collision detection). Our results show that the students that worked with visual languages perceived a higher clarity level in their understanding of the course exposition, and a higher enjoyment level in the use of the programming environment. Moreover, they also achieved an overall better mark

    La percepción que los corredores kenianos tienen de sus actividades entrenamiento

    Get PDF
    El presente estudio se enmarca dentro de la Teoría del RendimientoExperto. Esta teoría propone que para llegar a ser experto en undominio, un sujeto debe superar un periodo de adquisición extensivo consistenteen miles de horas de práctica intencionalmente diseñada para mejorar.El presente estudio buscó analizar las percepciones subjetivas de un grupode corredores kenianos de larga distancia sobre sus tareas de entrenamientopara lo cual cumplimentaron un cuestionario basado en una taxonomía deactividades de entrenamiento valoradas en cuatro dimensiones: Relevancia,Esfuerzo, Concentración y Diversión. En este estudio participaron 27 corredoresde fondo kenianos divididos en tres grupos de niveles por su marca.El rango de edades de los participantes fue de 21 a 39 años (M= 25,39; DT=3,82). Todos estos corredores eran especialistas de las pruebas de media maratóny maratón. Fueron divididos en tres grupos de nivel de rendimientopor su marca: Medio, Alto y Muy Alto. Los resultados mostraron comolas dimensiones de Concentración, Esfuerzo y Disfrute diferenciaron a loscorredores por su nivel, asímismo se manifestó el papel que las actividadesgrupales de entrenamiento tienen para estos corredores, lo que plantea lacuestiòn si los modelos de desarrollo de la excelencia desarrollados en enlos paises desarrollados sirven para explicar este fenómeno en los países envías de desarrollo

    Truncation-Driven Lateral Association of α-Synuclein Hinders Amyloid Clearance by the Hsp70-Based Disaggregase

    Get PDF
    The aggregation of α-synuclein is the hallmark of a collective of neurodegenerative disorders known as synucleinopathies. The tendency to aggregate of this protein, the toxicity of its aggregation intermediates and the ability of the cellular protein quality control system to clear these intermediates seems to be regulated, among other factors, by post-translational modifications (PTMs). Among these modifications, we consider herein proteolysis at both the N- and C-terminal regions of α-synuclein as a factor that could modulate disassembly of toxic amyloids by the human disaggregase, a combination of the chaperones Hsc70, DnaJB1 and Apg2. We find that, in contrast to aggregates of the protein lacking the N-terminus, which can be solubilized as efficiently as those of the WT protein, the deletion of the C-terminal domain, either in a recombinant context or as a consequence of calpain treatment, impaired Hsc70-mediated amyloid disassembly. Progressive removal of the negative charges at the C-terminal region induces lateral association of fibrils and type B* oligomers, precluding chaperone action. We propose that truncation-driven aggregate clumping impairs the mechanical action of chaperones, which includes fast protofilament unzipping coupled to depolymerization. Inhibition of the chaperone-mediated clearance of C-truncated species could explain their exacerbated toxicity and higher propensity to deposit found in vivo.This work was supported by grants PID2019-111068GB-I00 (to A.M.) (AEI/FEDER, UE) and PID2019-105872GB-I00 (to J.M.V.) (AEI/FEDER, UE) from the Ministry of Science and Innovation and by the Basque Government (grant IT1201-19 to AM). The Centro Nacional de Biotecnología (CNB) is a Severo Ochoa Center of Excellence (MINECO award SEV 2017-0712). N.O. holds a contract funded by Fundacion Biofisika Bizkaia. Acknowledgment

    Limitations of positioning systems for developing digital maps and locating vehicles according to the specifications of future driver assistance systems

    Get PDF
    Some advanced driver assistance systems require on-the-lane vehicle positioning on accurate digital maps. The combination of high precision global navigation satellite systems and inertial measurement is the most common technique to carry out this precise positioning since in some areas global positioning systems (GPS) signals are lost or degraded. However, real experimental validation of the navigation algorithms (beyond simulation) is one of the most important shortcomings in the state-of-the-art. In this study, a wide set of real experiments have been carried out on real roads, in urban and rural environments, using an instrumented car. A theoretical approach based on the uncertainty propagation law has been set out to evaluate the errors when using only inertial measurement systems and the maximum distance that can be travelled before exceeding the admissible error limits. Results show that it is better to correct GPS positioning when its signal is degraded than to wait until the signal is definitively lost. Furthermore, inertial measurement systems and GPS receivers of different levels of accuracy have been compared in order to determine whether they are suitable for new assistance applications. Experimental data are consistent with the theoretical approach.The work reported in this paper has been partly funded by the Spanish Ministry of Science and Innovation (SIAC project TRA2007-67786-C02-01 and TRA2007-67786-C02-02) and the CAM project SEGVAUTO.Publicad
    corecore