3,175 research outputs found
Towards a taxonomy of innovation systems
The concept of National Innovation System (NIS) has been recently applied in the context of developing nations even tough it was originally developed in relation to the more developed economies (Japan, Scandinavian countries, US etc.). This raises the methodological problem of knowing whether what was learnt in the study of more advanced NISs is relevant for all sorts of economies regardless the maturity of their actual innovation systems. With this question in mind an exploratory exercise is implemented. First a technique for mapping different NIS is put forward and next based on such mapping a taxonomy of NISs is proposed. The technique although simple in the steps it requires shows analytical potential. The cartography it generates allows one to compare directly different countries, by visualizing in bi-dimensional space the graphic pattern of the relevant dimensions of their respective NISs. This technique is applied to 69 countries (87.4% of the world population) and a set of 29 indicators is used to examine these NISs along eight major dimensions. With the resulting data, and with the help of cluster analysis, a taxonomy of innovation systems is proposed. That taxonomy which contains 6 major types of NISs indicates that what differentiates most the individual systems is their performance in three critical dimensions: innovation, diffusion and basic and applied knowledge. Country size and the natural resources endowment of the economies also emerge as important contingency factors underlying the overall dynamics of different NISs.innovation; national innovation systems; economic development.
Learning the importance of the sun as an important energy source by building “solar cars”
Learning the Importance of the Sun as na Important Energy Source by Building “Solar Cars”info:eu-repo/semantics/publishedVersio
Photorefraction images analysis through neural networks
The importance of an early evaluation of infants’ visual system condition is long time recognized. Non-corrected visual disorders may lead to major vision and developmental non-reversible limitations in the future. Among the objective methods of refraction, photorefractive techniques are specifically designed for screening young children. Over the years a number of photorefraction systems with different grades of complexity and automation were developed. A critical problem that one needs to deal with in any approach to these systems is the interpretation and classification of the photorefraction images. In digital photorefraction conventional image processing operators and Fourier techniques were currently used. In this communication we will report on the use of Neural Networks for automated classification of digital photorefraction images.Secretariado Nacional para a Reabilitação - programa CITE III
Comportamento a acções perpendiculares ao plano, de alvenaria de enchimento com dano prévio
Com a entrada em fase de obrigatoriedade dos EurocĂłdigos surgem novos requisitos que tĂŞm de ser cumpridos pelos edifĂcios, ou pelas suas partes. É o caso da exigĂŞncia de garantia de estabilidade de painĂ©is de alvenaria nĂŁo estrutural, Ă acção sĂsmica perpendicular ao plano, em edifĂcios com sistema estrutural de betĂŁo armado.
Este documento apresenta a campanha de ensaios realizada na Universidade do Minho, com vista Ă caracterização do comportamento de elementos deste tipo a estas acções, quando danificados previamente por acções no plano. Para o efeito o esquema de ensaio proposto Ă© composto por duas fases. Na primeira o painel Ă© sujeito, de forma cĂclica e gradual, a um nĂvel de deslocamento de referĂŞncia no plano. Na segunda Ă© sujeito a uma acção cĂclica, uniforme e perpendicular ao plano. SerĂŁo testadas e comparadas quatro soluções construtivas distintas, nomeadamente: parede simples nĂŁo reforçada, parede dupla nĂŁo reforçada, parede simples com reforço em junta horizontal e parede simples com reforço em malha de aço. De acordo com o desenvolvimento dos trabalhos, serĂŁo apresentados os resultados de uma parede simples
Drinking of Salvia officinalis tea increases CCl4-induced hepatotoxicity in mice
In a previous study, the drinking of a Salvia officinalis tea (prepared as an infusion) for 14 days improved liver antioxidant status in mice and rats where, among other factors, an enhancement of glutathione-S-transferase (GST) activity was observed. Taking in consideration these effects, in the present study the potential protective effects of sage tea drinking against a situation of hepatotoxicity due to free radical formation, such as that caused by carbon tetrachloride (CCl4), were evaluated in mice of both genders. Contrary to what was expected, sage tea drinking significantly increased the CCl4-induced liver injury, as seen by increased plasma transaminase levels and histology liver damage. In accordance with the previous study, sage tea drinking enhanced significantly GST activity. Additionally, glutathione peroxidase was also significantly increased by sage tea drinking. Since CCl4 toxicity results from its bioactivation mainly by cytochrome P450 (CYP) 2E1, the expression level of this protein was measured by Western Blot. An increase in CYP 2E1 protein was observed which may explain, at least in part, the potentiation of CCl4-induced hepatotoxicity conferred by sage tea drinking. The CCl4-induced hepatotoxicity was higher in females than males. In conclusion, our results indicate that, although sage tea did not have toxic effects of its own, herb–drug interactions are possible and may affect the efficacy and safety of concurrent medical therapy with drugs that are metabolized by phase I enzymes.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/6942/2001, POCI/AGR/62040/200
Phenolic compounds protect HepG2 cells from oxidative damage : relevance of glutathione levels
Prova tipográfica (In Press)In the present work, the potential hepatoprotective effects of five phenolic compounds were evaluated against oxidative damages induced by tert-butyl hydroperoxide (t-BHP) in HepG2 cells in order to relate in vitro antioxidant activity with cytoprotective effects. t-BHP induced considerable cell damages to HepG2 cells as shown by significant LDH leakage, increased lipid peroxidation, DNA damage as well as decreased reduced glutathione (GSH) levels. All tested phenolic compounds significantly decreased cell death induced by t-BHP (when in co-incubation). If the effects of quercetin are given the reference value 1, the compounds rank in the following order according to inhibition of cell death: luteolin (4.0) > quercetin (1.0) > rosmarinic acid (0.34) > luteolin-7-glucoside (0.30) > caffeic acid (0.21). The results underscore the importance of the compound’s lipophilicity in addition to its antioxidant potential for its biological activity. All tested phenolic compounds were found to significantly decrease lipid peroxidation and prevent GSH depletion induced by t-BHP, but only luteolin and quercetin significantly decreased DNA damage. Therefore, the lipophilicity of the natural antioxidants tested appeared to be of even higher importance for DNA protection than for cell survival. The protective potential against cell death was probably achieved mainly by preventing intracellular GSH depletion. The phenolic compounds studied here showed protective potential against oxidative damages induced in HepG2 cells that could be beneficial against liver diseases where it is known that oxidative stress plays a crucial role.Fundação para a Ciência e Tecnologia -SFRH/BD/6942/2001; POCTI/AGR/62040/2004
Autonomous vehicles in the response to maritime incidents
The future role of autonomous vehicles in the emergency response to maritime incidents isdiscussed and a framework for their integration into existing response plans is proposed. This is done inthe context of the developments on autonomous vehicle systems from the Underwater Systems andTechnologies Laboratory from Porto University
Towards a taxonomy of innovation systems
The concept of National Innovation System (NIS) has been recently applied in the context of developing nations even tough it was originally developed in relation to the more developed economies (Japan, Scandinavian countries, US etc.). This raises the methodological problem of knowing whether what was learnt in the study of more advanced NISs is relevant for all sorts of economies regardless the maturity of their actual innovation systems. With this question in mind an exploratory exercise is implemented. First a technique for mapping different NIS is put forward and next based on such mapping a taxonomy of NISs is proposed. The technique although simple in the steps it requires shows analytical potential. The cartography it generates allows one to compare directly different countries, by visualizing in bi-dimensional space the graphic pattern of the relevant dimensions of their respective NISs. This technique is applied to 69 countries (87.4% of the world population) and a set of 29 indicators is used to examine these NISs along eight major dimensions. With the resulting data, and with the help of cluster analysis, a taxonomy of innovation systems is proposed. That taxonomy which contains 6 major types of NISs indicates that what differentiates most the individual systems is their performance in three critical dimensions: innovation, diffusion and basic and applied knowledge. Country size and the natural resources endowment of the economies also emerge as important contingency factors underlying the overall dynamics of different NISs
The role of bacteria in pine wilt disease: insights from microbiome analysis.
Pine Wilt Disease (PWD) has a significant impact on Eurasia pine forests. The microbiome of the nematode (the primary cause of the disease), its insect vector, and the host tree may be relevant for the disease mechanism. The aim of this study was to characterize these microbiomes, from three PWD-affected areas in Portugal, using Denaturing Gradient Gel Electrophoresis, 16S rRNA gene pyrosequencing, and a functional inference-based approach (PICRUSt). The bacterial community structure of the nematode was significantly different from the infected trees but closely related to the insect vector, supporting the hypothesis that the nematode microbiome might be in part inherited from the insect. Sampling location influenced mostly the tree microbiome (P < 0.05). Genes related both with plant growth promotion and phytopathogenicity were predicted for the tree microbiome. Xenobiotic degradation functions were predicted in the nematode and insect microbiomes. Phytotoxin biosynthesis was also predicted for the nematode microbiome, supporting the theory of a direct contribution of the microbiome to tree-wilting. This is the first study that simultaneously characterized the nematode, tree and insect-vector microbiomes from the same affected areas, and overall the results support the hypothesis that the PWD microbiome plays an important role in the disease's development
Robotics in child storytelling
Although the field of Educational Robotics (ER) has been growing over the last
few years and its usefulness has been shown in many studies, its use in basic or elementary school levels has been scarce. This work intends to address the issue of demonstrating that ER makes a very useful tool at the elementary levels of learning, proposing a project-oriented
approach, where interdisciplinary work uses
children's stories and their imagination.
The project involved the use of Lego
Mindstorms robotics kits by students with ages between 9 and 12 years old. It involved the construction and programming of robots,
addressing the dramatization of the popular tales "Little Red Riding Hood" and "The Three little pigs" as the final goal. Also, other groups of students implemented fashion and dancing
shows, also with robots.
Each of the robots performed as one of the
characters of the story/ show, following a set of steps according to the script that was
programmed by the students. The work involved also a previous step where the robots were built and dressed according to its role. The final results show the applicability of ER to this level of learning/ teaching. The students were able to successfully complete the project, achieving the proposed aims and also showing high levels of motivation and enthusiasm through its whole duration. The work culminated with
public shows thatUniversidade do Minho. Centro de Investigação em Educação (CIEd-UMINHO
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