5,191 research outputs found

    Cursos superiores de tecnologia do IFRN – uma análise epistemológica do currículo

    Get PDF
    Atas do XI Colóquio sobre Questões Curriculares, VII Colóquio Luso-Brasileiro & I Colóquio Luso-Afro-Brasileiro de Questões CurricularesO presente trabalho enquadra-se numa pesquisa em curso no âmbito do doutoramento em Ciências da Educação, na especialidade de Desenvolvimento Curricular. Um dos objetivos da pesquisa é sistematizar e ampliar conhecimentos sobre as bases curriculares dos cursos de tecnologia e problematizar o currículo do ensino superior, considerando o atual contexto social demarcado por complexidades, incertezas e permanentes mudanças. Trata-se de um estudo de natureza qualitativa em que a pesquisa documental é uma das fontes para a recolha de dados. Nesta comunicação incide-se nalguns resultados de uma investigação bibliográfica acerca do currículo dos cursos de tecnologia do IFRN, enfocando o estudo das bases epistemológicas do desenho curricular dos cursos de graduação tecnológica reformulados a partir de 2009 e implementados, na Instituição, em 2012. A primeira parte trata da caracterização e contextualização dos cursos tecnológicos no IFRN, situando-os historicamente e acerca das bases conceituais e metodológicas orientadoras das revisões curriculares do atual contexto institucional. A segunda parte apresenta uma descrição e análise dos princípios organizadores da proposta curricular desses cursos no IFRN, as implicações didáticas e suas articulações com as necessidades formativas dos docentes do ensino superior. Desse modo, espera-se refletir a respeito da proposta curricular dos cursos de graduação tecnológica, a partir da compreensão de uma formação superior integral e produtora de sentidos no âmbito da formação humana, pessoal e profissional, tanto na perspectiva de docentes, quanto de discentes. Visa ainda, ampliar o conhecimento a respeito da concepção e do desenvolvimento curricular nos cursos de graduação tecnológica e contribuir com sistematizações teórico metodológicas que venham a fortalecer o ensino superior e a atuação docente nesse campo de formação. Em síntese, ao se estabelecer relações entre a epistemologia dos conhecimentos teóricos e a epistemologia dos saberes da prática, o estudo busca sistematizar contributos para a construção de uma nova pedagogia universitária.Fundação para a Ciência e a Tecnologia (FCT

    The experience of meaning in circle dance

    Get PDF
    Circle dance, which derives from the tradition of folk dances, is practised worldwide. This article explores the meanings participants attribute to it. In-depth interviews with 39 participants, teachers and coordinators of teacher training programmes from the circle dance network in the United Kingdom were undertaken. Applying a constructivist grounded theory approach, major categories, representing respectively the experiences of circle dance participants, teachers and coordinators, were developed. This article specifically focuses on the first major category, termed “I can’t imagine life without it”, which relates to the experience of 22 dancers. From an occupational perspective, the study reveals how participants realise a sense of meaning and satisfaction through engagement in circle dance and the potential contribution of this occupation to well-being

    The recent sovereign debt crisis in the Euro zone: A matter of fundamentals?

    Get PDF
    The idea that the Euro zone sovereign debt crisis was caused by structural weaknesses degenerating into fundamental macroeconomic imbalances in the peripheral countries prevails among international institutions such as the IMF, the ECB, and the European Commission. On the contrary, some economists believe that this crisis is the consequence of major deficiencies in the architecture of economic policy making in the Euro zone that did not allow a proper response to a global systemic crisis of the financial markets that started in the United States. The objective of this paper is to provide a better understanding of the public debt dynamics in the EU, differentiating the case of Euro zone peripheral countries. We used quarterly data from 2000 to 2011 to estimate a small-scale model that takes into account the interactions between key variables. Our results do not support entirely the official view. We conclude that the cause of the adverse debt dynamics unravelling after 2007 was a sharp GDP contraction, coupled with a substantial increase in the interest cost of debt finance due to higher self-fulfilling solvency risks perceived by creditors, interacting with a higher sensitiveness of Euro zone peripheral countries to fundamentals

    Chitosan/sulfated locust bean gum nanoparticles: In vitro and in vivo evaluation towards an application in oral immunization

    Get PDF
    This work proposes the design of nanoparticles based on locus bean gum (LBG) and chitosan to be used as oral immunoadjuvant for vaccination purposes. LBG-based nanoparticles were prepared by mild polyelectrolyte complexation between chitosan (CS) and a synthesized LBG sulfate derivative (LBGS). Morphological characterization suggested that nanoparticles present a solid and compact structure with spherical-like shape. Sizes around 180-200 nm and a positive surface charge between +9 mV and +14 mV were obtained. CS/LBGS nanoparticles did not affect cell viability of Caco-2 cells after 3 h and 24h of exposure when tested at concentrations up to 1.0 mg/mL. Two model antigens (a particulate acellular extract HE of Salmonella enterica serovar Enteritidis, and ovalbumin as soluble antigen) were associated to CS/LBGS nanoparticles with efficiencies around 26% for ovalbumin and 32% for HE, which resulted in loading capacities up to 12%. The process did not affect the antigenicity of the associated antigens. BALB/c mice were orally immunized with ovalbumin-loaded nanoparticles (100 mu g), and results indicate an adjuvant effect of the CS/LBGS nanoparticles, eliciting a balanced Th1/Th2 immune response. Thus, CS/LBGS nanoparticles are promising as antigen mucosal delivery strategy, with particular interest for oral administration. (C) 2017 Elsevier B.V. All rights reserved.National Portuguese funding through FCT- Fundacao para a Ciencia e a Tecnologia, project [PTDC/SAU-FCF/100291/2008, PEst-OE/EQB/LA0023/2011]FEDER - Fundo Europeu de Desenvolvimento RegionalPortuguese funds through FCT - Fundacao para a Ciencia e a Tecnologia/Ministerio da Cienci

    A Global optimization stochastic algorithm for head motion stabilization during quadruped robot locomotion

    Get PDF
    Visually-guided locomotion is important for autonomous robotics. However, there are several di culties, for instance, the robot locomotion induces head shaking that constraints stable image acquisition and the possibility to rely on that information to act accordingly. In this work, we propose a combined approach based on a controller architecture that is able to generate locomotion for a quadruped robot and a genetic algorithm to generate head movement stabilization. The movement controllers are biologically inspired in the concept of Central Pattern Generators (CPGs) that are modelled based on nonlinear dynamical systems, coupled Hopf oscillators. This approach allows to explicitly specify parameters such as ampli- tude, o set and frequency of movement and to smoothly modulate the generated oscillations according to changes in these parameters. Thus, in order to achieve the desired head movement, opposed to the one induced by locomotion, it is necessary to appropriately tune the CPG parameters. Since this is a non-linear and non-convex optimization problem, the tuning of CPG parameters is achieved by using a global optimization method. The genetic algorithm searches for the best set of parameters that generates the head movement in order to reduce the head shaking caused by locomotion. Optimization is done o ine according to the head movement induced by the locomotion when no stabilization procedure was performed. In order to evaluate the resulting head movement, a tness function based on the Euclidian norm is investigated. Moreover, a constraint handling technique based on tournament selection was im- plemented. Experimental results on a simulated AIBO robot demonstrate that the proposed approach generates head movement that reduces signi cantly the one induced by locomotion

    Anti-aging activity of Lobophora variegata ethanolic and methanolic extracts and their fractions

    Get PDF
    Conference Report XVI International Symposium on Marine Natural Products | XI European Conference on Marine Natural Products, 1-5 September 2019, Peniche, Portugal.Seaweed have promising applications within food, cosmetic and health industries, which led to an increased interest in studying these organisms [1]. In several coastal areas, thousands of tons of macroalgae are cast on beaches and shorelines and it would be very interesting if this biomass could be managed, allowing the extraction of added-value compounds. In this context, polar extracts (methanol and ethanol) of a macroalgal beach cast sample mainly composed of “Lobophora variegate” were prepared and the anti-aging and antioxidant activities were evaluated. The preliminary results showed interesting results, and thus these crude extracts were then fractionated sequentially by their solubility in dichloromethane, acetone and ethyl acetate, resulting in 4 semi-pure fractions each, which were also tested. Fractions A1.1.1 and A1.2.3 were very good tyrosinase inhibitors (IC₅₀ = 37.87 and 24.01 μg/mL, respectively) and fractions A1.1.2 and A1.2.2 presented very good inhibition of elastase (IC₅₀ = 44.76 and 20.86 μg/mL, respectively). However, none of the fractions was active against collagenase. These results show that further purifications of these fractions can lead to the isolation of bioactive added-value compounds.info:eu-repo/semantics/publishedVersio

    Probing cellulose–solvent interactions with self-diffusion NMR: Onium hydroxide concentration and co-solvent effects

    Get PDF
    The molecular self-diffusion coefficients were accessed, for the first time, in solutions of microcrystalline cel-lulose, dissolved in 30 wt% and 55 wt% aqueous tetrabutylammonium hydroxide, TBAH (aq), and in mixtures of 40 wt% TBAH (aq) with an organic co-solvent, dimethylsulfoxide (DMSO), through pulsed field gradient stim-ulated echo NMR measurements. A two-state model was applied to estimate alpha (i.e., average number of ions that "bind" to each anhydroglucose unit) and Pb (i.e., fraction of "bound" molecules of DMSO, TBAH or H2O to cellulose) parameters. The alpha values suggest that TBA+ ions can bind to cellulose within 0.5 TBA+ to 2.3 TBA+/ AGU. On the other hand, the Pb parameter increases when raising cellulose concentration for TBA+, DMSO and water in all solvent systems. Data suggests that TBAH interacts with the ionized OH groups from cellulose forming a sheath of bulky TBA+ counterions which consequently leads to steric hindrance between cellulose chains.info:eu-repo/semantics/publishedVersio

    In situ enabling approaches for tissue regeneration: current challenges and new developments

    Get PDF
    In situ tissue regeneration can be defined as the implantation of tissue-specific biomaterials (by itself or in combination with cells and/or biomolecules) at the tissue defect, taking advantage of the surrounding microenvironment as a natural bioreactor. Up to now, the structures used were based on particles or gels. However, with the technological progress, the materials’ manipulation and processing has become possible, mimicking the damaged tissue directly at the defect site. This paper presents a comprehensive review of current and advanced in situ strategies for tissue regeneration. Recent advances to put in practice the in situ regeneration concept have been mainly focused on bioinks and bioprinting techniques rather than the combination of different technologies to make the real in situ regeneration. The limitation of conventional approaches (e.g., stem cell recruitment) and their poor ability to mimic native tissue are discussed. Moreover, the way of advanced strategies such as 3D/4D bioprinting and hybrid approaches may contribute to overcome the limitations of conventional strategies are highlighted. Finally, the future trends and main research challenges of in situ enabling approaches are discussed considering in vitro and in vivo evidence.info:eu-repo/semantics/publishedVersio
    corecore