259 research outputs found

    3d printing and testing of rose thorns or limpet teeth inspired anchor device for tendon tissue repair

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    Purposes: Advancements in medical technology have enabled medical specialists to resolve significant problems concerning tendon injuries. However, despite the latest improvements, surgical tendon repair remains challenging. This study aimed to explore the capabilities of the current state-of-the-art technologies for implantable devices. Methods: After performing extensive patent landscaping and literature review, an anchored tissue fixation device was deemed the most suitable candidate. This design was firstly investigated numerically, realizing a Finite Element Model of the device anchored to two swine tendons stumps, to simulate its application on a severed tendon. Two different hook designs, both bio-inspired, were tested while retaining the same device geometry and anchoring strategy. Then, the applicability of a 3D-printed prototype was tested on swine tendons. Finally, the device-tendon stumps ensemble was subjected to uniaxial tensile tests. Results: The results show that the investigated device enables a better load distribution during the immobilized limb period in comparison to standard suture-based approaches, yet it still presents several design flaws. Conclusions: The current implantable solutions do not ensure an optimal result in terms of strength recovery. This and other weak points of the currently available proposals will serve as a starting point for future works on bio-inspired implantable devices for tendon repair

    El consentimiento informado en las publicaciones latinoamericanas de Psicología

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    RESUMEN El propósito fue determinar si las publicaciones psicológicas incluyen el consentimiento informado en el procedimiento de sus investigaciones. Se analizaron 1924 artículos de investigaciones empíricas, de ocho países de América Latina, publicados entre los años 1994 y 2012 en revistas indexadas en el catálogo de Latindex. La obtención del consentimiento informado se incrementó muy irregularmente en el año 2012; sin embargo, hay un alto porcentaje de publicaciones que no lo obtuvieron. Los países que contemplan el consentimiento informado en sus códigos de ética tienden a su mayor aplicación. Consecuentemente, no solo es necesario normar el consentimiento informado sino también promover la reflexión crítica de la dimensión científica de la Psicología en un marco deontológico y ético, desde la formación profesional

    Using ANN and combined capacitive sensors to predict the void fraction for a two-phase homogeneous fluid independent of the liquid phase type

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    Measuring the void fraction of different multiphase flows in various fields such as gas, oil, chemical, and petrochemical industries is very important. Various methods exist for this purpose. Among these methods, the capacitive sensor has been widely used. The thing that affects the performance of capacitance sensors is fluid properties. For instance, density, pressure, and temperature can cause vast errors in the measurement of the void fraction. A routine calibration, which is very grueling, is one approach to tackling this issue. In the present investigation, an artificial neural network (ANN) was modeled to measure the gas percentage of a two-phase flow regardless of the liquid phase type and changes, without having to recalibrate. For this goal, a new combined capacitance-based sensor was designed. This combined sensor was simulated with COMSOL Multiphysics software. Five different liquids were simulated: oil, gasoil, gasoline, crude oil, and water. To estimate the gas percentage of a homogeneous two-phase fluid with a distinct type of liquid, data obtained from COMSOL Multiphysics were used as input to train a multilayer perceptron network (MLP). The proposed neural network was modeled in MATLAB software. Using the new and accurate metering system, the proposed MLP model could predict the void fraction with a mean absolute error (MAE) of 4.919

    Spatial and environmental drivers of macrophyte diversity and community composition in temperate and tropical calcareous rivers

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    The hypothesis was examined that sources of variation in macrophyte species richness (alpha-diversity: S) and community composition (“species-set”), attributable to spatial and environmental, variables, may differ in importance between tropical and temperate calcareous rivers (>10 mg CaCO3 L−1). To test this hypothesis geographic, environmental, and aquatic vegetation data was acquired for 1151 sites on calcareous rivers within the British Isles, supporting 106 macrophyte species (mean S: 3.1 species per sample), and 203 sites from Zambian calcareous rivers, supporting 255 macrophyte species (mean S: 8.3 species per sample). The data were analysed using an eigenfunction spatial analysis procedure, Moran’s Eigenvector Maps (MEM), to assess spatial variation of species richness and community composition at large regional scale (>105 km2: British Isles and Zambia); and at medium catchment scale (104–105 km2: British Isles only). Variation-partitioning was undertaken using multiple regression for species richness data, and partial redundancy analysis (pRDA) for community data. For the British Isles, spatial and environmental variables both significantly contributed to explaining variation in both species richness and community composition. In addition, a substantial amount of the variation in community composition, for the British Isles as a whole and for some RBUs, was accounted for by spatially-structured environmental variables. In Zambia, species richness was explained only by pure spatial variables, but environmental and spatially-structured environmental variables also explained a significant part of the variation for community composition. At medium-scale, in the British Isles, species richness was explained by spatial variables, and only for four of the six RBUs

    Environmental drivers of aquatic macrophyte communities in southern tropical African rivers:Zambia as a case study

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    The first-ever extensive macrophyte survey of Zambian rivers and associated floodplain waterbodies, conducted during 2006–2012, collected 271 samples from 228 sites, mainly located in five freshwater ecoregions of the world primarily represented in Zambia. The results supported the hypothesis that variation in macrophyte community structure (measured as species composition and diversity) in southern tropical African river systems, using Zambia as a case study area, is driven primarily by geographical variation in water physico-chemical conditions. In total, 335 macrophyte taxa were recorded, and a chronological cumulative species records curve for the dataset showed no sign of asymptoting: clearly many additional macrophyte species remain to be found in Zambian rivers. Emergent macrophytes were predominant (236 taxa), together with 26 floating and 73 submerged taxa. Several species were rare in a regional or international context, including two IUCN Red Data List species: Aponogeton rehmanii and Nymphaea divaricata. Ordination and classification analysis of the data found little evidence for temporal change in vegetation, at repeatedly-sampled sites, but strong evidence for the existence of seven groups of samples from geographically-varied study sites. These supported differing sets of vegetation (with eight species assemblages present in the sample-groups) and showed substantial inter-group differences in both macrophyte alpha-diversity, and geographically-varying physico-chemical parameters. The evidence suggested that the main environmental drivers of macrophyte community composition and diversity were altitude, stream order, shade, pH, alkalinity, NO3-N, and underwater light availability, while PO4-P showed slightly lower, but still significant variation between sample-groups

    Data Sharing and Research on Peer Review: A Call to Action

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    While recent surveys show that most stakeholders recognise the importance of peer review to the publication process, there is a lack of systematic research on the topic. In a period of hyper-competition for resources, with perverse incentives that lead to academic capitalism and a \u201cpublish or perish\u201d mentality, the lack of robust and cumulative research on approaches, models and practices of peer review can slow down efforts towards fostering research integrity and the credibility of scholarly communication. A major challenge in studying peer review systematically is the lack of available data. While data sharing in scientific research has made relevant progress in certain fields, the lack of infrastructures to promote the sharing of peer review data among publishers, journals and academic scholars, the challenges posed by privacy and data protection legislation, and the perceived lack of incentives for publishers, learned societies and journals to share data, have all hampered efforts in this important domain. While public authorities, learned societies and publishers may face different priorities, incentives and obstacles regarding data sharing, the time has come to call to action all stakeholders who play a part in this field. In this paper, we argue that an infrastructure for data sharing is needed to stimulate independent, collaborative, public research on peer review and we suggest measures and initiatives to set up a collaborative effort towards this goal

    Unlock ways to share data on peer review

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    Peer review is the defining feature of scholarly communication. In a 2018 survey of more than 11,000 researchers, 98% said that they considered peer review important or extremely important for ensuring the quality and integrity of scholarly communication. Indeed, now that the Internet and social media have assumed journals\u2019 original role of dissemination, a journal\u2019s main function is curation. Both the public and the scientific community trust peer review to uphold shared values of rigour, ethics, originality and analysis by improving publications and filtering out weak or errant ones. Scholarly communities rely on peer review to establish common knowledge and credit

    Protein Short-Time Diffusion in a Naturally Crowded Environment.

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    The interior of living cells is a dense and polydisperse suspension of macromolecules. Such a complex system challenges an understanding in terms of colloidal suspensions. As a fundamental test we employ neutron spectroscopy to measure the diffusion of tracer proteins (immunoglobulins) in a cell-like environment (cell lysate) with explicit control over crowding conditions. In combination with Stokesian dynamics simulation, we address protein diffusion on nanosecond time scales where hydrodynamic interactions dominate over negligible protein collisions. We successfully link the experimental results on these complex, flexible molecules with coarse-grained simulations providing a consistent understanding by colloid theories. Both experiments and simulations show that tracers in polydisperse solutions close to the effective particle radius Reff = ⟨ Ri3⟩1/3 diffuse approximately as if the suspension was monodisperse. The simulations further show that macromolecules of sizes R > Reff ( R < Reff) are slowed more (less) effectively even at nanosecond time scales, which is highly relevant for a quantitative understanding of cellular processes

    Diseño e implementación de juegos en el aula utilizando herramientas de respuesta de audiencia

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    El aprendizaje basado en juegos se basa en introducir el juego en las aulas para mejorar aspectos como el rendimiento, la concentración y el esfuerzo del alumnado. En la actualidad, proporciona un recurso muy útil para incrementar la motivación del alumnado universitario, generando un mejor clima entre compañeros y entre alumno y profesor, el cual en muchas ocasiones se traduce en mejores resultados académicos. Sin embargo, diseñar juegos que consigan con éxito los objetivos de enseñanza-aprendizaje deseados no es una tarea trivial. Este trabajo propone tres juegos basados en la participación por equipos que pueden ser fácilmente implementados utilizando plataformas online existentes. En el diseño de los mismos, se ha tenido en cuenta la experiencia previa de los alumnos en el uso de herramientas de respuesta de audiencia, así como en su participación en juegos en el aula. Tras llevar a cabo los juegos en distintas asignaturas relacionadas con el campo de las TIC, se ha evaluado el impacto de esta actividad mediante encuestas de satisfacción cumplimentadas por el alumnado.The so-called game-based learning strategies are based on introducing games in the classrooms to improve aspects such as student performance, concentration and effort. Currently, they provide a very useful resource to increase the motivation of university students, generating a better atmosphere among peers and between student and teacher, which in turn is generally translated into better academic results. However, the design of games that successfully achieve the desired teaching-learning objectives is not a trivial task. This paper proposes three games based on team participation that can be easily implemented using existing online platforms. The design of these games has taken into account the previous experience of the students in the use of audience response tools, as well as their participation in games in the classroom. After carrying out the games in different ICT-related subjects, we evaluated the impact of this activity using questionnaires collecting students’ assessments.Este proyecto ha sido financiado por la UV (Servei de Formació Permanent i Innovació Educativa) en el contexto del proyecto UV-SFPIE_GER18-848990
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