Technologies may help thinking

The objective of teachers’ personal and professional development is an excellent reason to reflect upon the innovation issues in education and a rare opportunity to implement the use of portfolios in the teaching practices. The most recent developments of digital technologies allow experiencing new organisational and knowledge building that state the diversity and multiplicity of purposes, both alone and as a group. From the reflection on these two aspects comes up the present proposal for the analysis and evaluation of the technologies which may easily be accessed by the educational community and may be used in the process of electronic portfolios building. In what teachers are concerned the use of portfolios can become a powerful means helping the change of the educational practices (Cardoso, Peixoto, Serrano and Moreira, 1996) if it is adopted as a metacognitive and reflexive strategy about teaching about them (Galvão, 2005). However there is a lack of information about what portfolios are, which technologies can be used, how they are prepared and how to take advantage of them. All these questions point out to the need of a specific training in this field. Accordingly, this chapter especially aims at helping teachers in that process, providing an analysis and evaluation technologies grid based on their pedagogical potentialities for the building of digital portfolios

Managing personal learning environments: the voice of the students

The main purpose of this paper is to contribute to a better understanding of the kind of educational work to be done with higher education students (undergraduate) in order to encourage them to create and use personal learning environments (PLEs) as a strategy for learning (Attwell, 2007). Based on our current classroom work with students of the 2nd year of a degree in Education and mainly using the functionalities of the Ning system (Copyright © 2010 Ning, Inc.), as well as other tools available on the Internet, we tried to implement a strategy based not only on the presentation of content by the teacher, but also on the recognition of the importance of student’s leadership in the organisation and management of their own learning. Therefore, in addition to face-to-face lectures, we tried to extend the discussion outside the classroom walls using the different services offered by Ning, proposing to integrate the work done by students in their individual evaluation (50% of the final classification). At the end of the semester we observed evidence of a general difficulty felt by the students, particularly in terms of self-regulation and personal organisation. So we decided to try to understand the problem observed in depth. For the purpose of understanding the nature and the extent of these difficulties, we used a methodology focused on analysis of a questionnaire applied to the students about their perception of the difficulties in managing the learning process and about the strategies used for dealing with those difficulties. Although the students acknowledge that the development of the individual online portfolio in a PLE requires that, for the most part, largely they themselves have to get organised and manage of their own learning (Barrett, 2000; Attwell, 2007), one can see that they do not feel prepared for this, experiencing difficulties in personal organisation, time management and regular participation in the proposed activities. In strategic terms, they value the appraisals and/or suggestions given by the teachers, but do not adopt an attitude of reflection or interaction and sharing with others, as catered for by the platform and its functionalities

Abnormal regulation of Na,K-ATPase in Glucose Intolerant Rats.

Introduction: Glucose is the most important physiological insulin secretagogue. However, the mechanisms underlying glucose-induced insulin release are not fully understood. The role of electrogenic systems such as ionic pumps, to these events remains essentially uninvestigated. Na,K-ATPase, responsible for maintaining Na+ and K+ gradients across the plasma membrane and generates a net outward current, thus changes in its activity may contribute to the early ionic events regulating insulin secretion (Therien and Blostein, 2000). Objective: The aim of this work was to evaluate the regulation of Na,K-ATPase activity by glucose in intact -cells of normal and glucose intolerant (GI) rats and its putative contribution to the regulation of insulin secretion. Material and Methods: Pancreatic -cells, from normal or control or GI rats, were isolated and cultured (48h). Cell batches were pre-incubated (30min) with 2mM glucose to reach basal. Afterwards cells were challenged with glucose in the interval 0-11mM for 60min, for dose-dependence evaluation, or with 8mM glucose for 5-120min, for time-dependence evaluation. ATPase activity was assessed in intact cells by colorimetric quantification of Pi formed in 30min. Na,K-ATPase activity was calculated by the difference between the activities obtained in the absence and in presence the of 1mM ouabain (Costa et al., 2009). Results: In β-cells from normal rats, glucose induced a bimodal regulation of Na,K-ATPase. In the absence of glucose, Na,K-ATPase activity was 0.056±0.015 U/mg. Stimulation with 2mM glucose induced an increase of Na,K-ATPase activity of ~4 fold whereas for [glucose] above 2mM it was observed a significant inhibition of Na,K-ATPase activity (0.061±0.013, 0.080±0.009 and 0.064±0.005 U/mg for 5.6, 8.4 and 11mM glucose, respectively, compared to 0.188±0.035 U/mg observed in 2mM G; n=3-8). β-cells from GI rats does not present this profile; in the absence of glucose, Na,K-ATPase activity was 0.202±0.036 U/mg and no significant differences from this value were observed with the other glucose concentration tested. Addicionally, in β-cells from normal rats, glucose (8mM) induced a time-dependent inhibition, with a biphasic profile, of Na,K-ATPase - it was observed a decrease in the pump activity between 0 and 20min stimulation where it reached a minimum value (77%). For incubation periods over 20min, the pump activity slowly and partially recovered (54%, 55% and 52%, for 30, 60 and 120min, respectively; n=7). In β-cells from GI animals, an less accentuated decrease of Na,K-ATPase activity between 0 ans 20min was also observed (34%), and is not observed further recover in activity. Conclusions: This work demonstrates there Na,K-ATPase is strictly regulated by glucose in pancreatic β-cell. This regulation is unpaired in GI animals. Na,K-ATPase contribution to glucose-induced ionic events and insulin secretion might be relevant and must be explored as a possible therapeutic target in TD2 . 1. Therien AG, Blostein R (2000) Mechanisms of sodium pump regulation. Am J Physiol Cell Physiol 279:C541-C566 2. Costa AR, Real J, Antunes CM, Cruz-Morais J (2009) A new approach for determination of Na,K-ATPase activity: application to intact pancreatic beta-cells. In Vitro Cell Dev Biol Ani

Implication of AMPK in glucose-evoked modulation of Na,K-ATPase

Background and aims: Na,K-ATPase is an integral membrane protein that maintains the gradients of Na+ and K+, using the energy of ATP hydrolysis, maintaining the ionic gradients that allow electrical activity to occur. It has been demonstrated that, in pancreatic β-cells, Na,K-ATPase is regulated by glucose and that this phenomenon is impaired in glucose intolerant subjects. However, the mechanism underlying glucose-induced modulation of Na,K-ATPase is still unclear. The AMP-activated protein kinase (AMPK) is a molecular key player in energy homeostasis, providing exquisite sensitivity to small changes in intracellular AMP levels and thus to intracellular [ATP]/[ADP] ratio, that is known to activate protein regulatory pathways. Since in pancreatic β-cell, glucose has marked effects on oxidative metabolism and total intracellular ATP and AMP levels, the involvement of AMPK in the cascade of events regulating Na,K-ATPase regulation in pancreatic β-cells was postulated. The aim of this work was to evaluate the putative role of AMPK in the glucose-evoked regulation of Na,K-ATPase activity in the pancreatic β-cell. Materials and methods: Pancreatic -cells from normal (control) or glucose-intolerant Wistar rats (GIR) were isolated and cultured (48h). Cell batches were pre-incubated (30min) with 2.1mM glucose to reach basal activity. Afterwards cells were challenged to 8.4mM glucose for 20min, in the presence or absence of AMPK agonists (AICAR) and antagonists (compound C; CC). ATPase activity was assessed in intact cells by colorimetric quantification of Pi formed in 30min. Na,K-ATPase activity was calculated by the difference between the activities obtained in the absence and in presence the of 1mM ouabain. Results: In basal conditions the activity of Na,K-ATPase from normal and GIR pancreatic β-cell was similar (0.184±0.030 and 0.186±0.020 molPi/min/mgProt, respectively). Challenging the control β-cells with glucose 8.4mM evoked a 62% reduction of Na,K-ATPase activity whereas in GIR β-cells a significantly lower inhibition (40%) was observed. The addition of AICAR 1mM abolished glucose-induced Na,K-ATPase inhibition (0,166±0.011 molPi/min/mg). In control β-cell, the addition of CC 10 μM had no effect on glucose-induced inhibition of Na,K-ATPase. In the contrary, in GIR β-cells it significantly potentiated glucose-evoked inhibition of Na,K-ATPase reaching values similar to that observed in the controls (66%). Conclusions: The AMPK agonist AICAR counteracts the inhibitory action of glucose on Na,K-ATPase of control β-cells whereas CC amplified the glucose-induced inhibition of Na,K-ATPase in GIR β-cells. These results suggest that AMPK plays a central role in the cascade of events underlying glucose-induced modulation of Na,K-ATPase and that the defect must be upstream of AMPK. Finally, abnormal glucose-induced regulation of Na,K-ATPase occurs prior to overt type 2 diabetes and might be a feature in the disease development

Automatic Test Generation for Space

The European Space Agency (ESA) uses an engine to perform tests in the Ground Segment infrastructure, specially the Operational Simulator. This engine uses many different tools to ensure the development of regression testing infrastructure and these tests perform black-box testing to the C++ simulator implementation. VST (VisionSpace Technologies) is one of the companies that provides these services to ESA and they need a tool to infer automatically tests from the existing C++ code, instead of writing manually scripts to perform tests. With this motivation in mind, this paper explores automatic testing approaches and tools in order to propose a system that satisfies VST needs

How to control market power of activity centres? A theoretical model showing the advantages of implementing competition within organizations

One important issue in firms’ governance is how to create incentives so that activity centres can become more efficient. In this paper, we first introduce an agency contract where the salary of the manager of an activity centre that produces an intermediate product is dependent of its performance. Secondly, we add competition within the organization. This latter point is new in the literature. We then develop a "static analysis" comparing a firm that has only one activity centre producing an intermediate product with another firm that has two activity centres producing the same intermediate product, in a context where the technology manifests increasing returns to scale. We conclude that the introduction of internal competition makes the firm globally more efficient, even though it cannot fully explore the existence of increasing returns to scale.Activity centres, internal market power, firm efficiency

Evaluation of different extenders for cold storage of meagre (Argyrosomus regius) semen

Dissertação de Mestrado Integrado em Medicina VeterináriaSemen refrigeration is usually recommended as a cheap and simple procedure that facilitates artificial reproduction techniques. The main objective of this experiment was to develop a semen refrigeration protocol for meagre that is considered a potential candidate for aquaculture diversification in Southern Europe. This thesis also contributes for the understanding of the causes of the fish sperm quality degradation during refrigeration. Three extenders (non-activating medium (Fauvel et al., 1998); NaCl 0.9% and; NaCl 0.9% with glycine and glucose) and three different dilutions (1:4, 1:9 and 1:19, sperm:extender) were tested in a full factorial design. The following quality parameters were assessed along the storage time: sperm motility parameters; percentage of viable sperm; adenosine triphosphate (ATP); lipid peroxidation in the form of malondialdehyde (MDA); and bacteriology. The 0.9% NaCl and the 0.9% NaCl with glycine and glucose extenders and the dilutions 1:4 and 1:9 kept a higher percentage of motile cells for longer, as well as higher sperm velocity. Sperm viability and ATP had better results with 0.9% NaCl and the 0.9% NaCl with glycine and glucose extenders. The MDA values were lower in treatments with dilution 1:4 when compared to those with dilution 1:9. In the CFU/ml values, no differences were found between extenders and dilutions. Motility parameters were strongly correlated with viability, whereas no or weak correlations existed with the remaining parameters. Thus, motility and viability seem to have the most impact in the loss of semen quality. According to the results, meagre semen could be kept refrigerated using 0.9% NaCl, in dilution 1:4, for up to 10 days.RESUMO - AVALIAÇÃO DE DIFERENTES DILUIDORES PARA A REFRIGERAÇÃO DE SÉMEN DE CORVINA (ARGYROSOMUS REGIUS) - A refrigeração de sémen é tipicamente recomendada como um procedimento barato e simples que facilita as técnicas de reprodução artificial. O principal objectivo desta experiência foi desenvolver um protocolo de refrigeração de sémen para a corvina, que é considerada uma potencial candidata para a diversificação de aquacultura no sul da Europa. Esta tese contribui também para a compreensão das causas da degradação da qualidade de sémen de peixe durante a refrigeração. Três diluidores (non-activating medium (Fauvel et al., 1998); NaCl 0,9%; e NaCl 0,9% com glicina e glucose) em três diferentes diluições (1:4, 1:9 e 1:19, sémen:diluidor) foram testados num plano factorial completo. Os seguintes parâmetros de qualidade espermática foram avaliados ao longo do tempo de armazenamento: parâmetros de mobilidade do sémen; percentagem de espermatozoides viáveis; adenosina trifosfato (ATP); peroxidação lipídica na forma de malondialdeído (MDA); e bacteriologia. Os diluidores NaCl 0,9% e NaCl 0,9% com glicina e glucose e as diluições 1:4 e 1:9 mantiveram uma percentagem de células móveis mais elevada por mais tempo, bem como maior velocidade dos espermatozóides. A viabilidade e o ATP tiveram melhores resultados com NaCl 0,9% e NaCl 0,9% com glicina e glucose. Os valores de MDA foram mais baixos em tratamentos com as diluições 1:4, quando comparados com aqueles com as diluições 1:9. Nos valores de bacteriologia não foram encontradas diferenças entre diluidores e diluições testadas. Os parâmetros de mobilidade correlacionaram-se fortemente com a viabilidade, enquanto inexistentes ou fracas correlações foram encontradas entre os restantes parâmetros. Por conseguinte, mobilidade e viabilidade parecem ter o maior impacto na perda de qualidade do sémen. De acordo com os resultados, o sémen de corvina pode ser mantido refrigerado usando o diluidor NaCl 0,9% na diluição 1:4 até 10 dias.N/

Growth and development of Chrysaora quinquecirrha reared under different diet compositions

Tese de mestrado, Ecologia Marinha, Universidade de Lisboa, Faculdade de Ciências, 2015As a contribution to further understanding the growth and rearing in aquaculture of the jellyfish Chrysaora quinquecirrha, laboratorial experiments were conducted in order to evaluate key differences in growth in regards to different food items given to ephyras, identifying the best diet for this species and development stage, and thus contributing to the optimization of its aquaculture. 9 tanks were set up where medusa were fed 3 different diets in 3 replicate tanks each – 3 replicate tanks were fed enriched Artemia nauplii, 3 were fed Acartia grani copepods enriched with Rhodomonas sp. and the last 3 were fed minced Aurelia aurita. The main aim was to identify the diet that translated into maximum ephyra growth of Chrysaora quinquecirrha for a 31 day period (with 10 ephyras per tank with identical size and age). Ephyra pulses were monitored daily and there were no significant differences between ephyra grown with different diets, revealing that all prey elicited a similar feeding response. However, growth rates were significantly different for ephyra grown with different diets. The diet that resulted in highest growth rates of the ephyras consisted in minced Aurelia aurita (2.6mm ±SD over the course of 31 days), followed by the diet consisting of copepods (1.8mm ±SD over the course of 31 days) and finally the diet based on Artemia nauplii (1.08mm ±SD over the course of 31 days). This study recommends that the dietary supplementation with copepods or minced Aurelia aurita is an important enhancement of the management of Chrysaora quinquecirrha ephyra culture, and that growth rates can be elevated from 83.1% to 128.6% (Acartia grani) and 185.7% (Aurelia aurita) when compared to the traditional diet.Como contributo para a compreensão do crescimento e criação em aquacultura da medusa Chrysaora quinquecirrha, experiências laboratoriais foram realizados a fim de avaliar as principais diferenças no crescimento em relação a diferentes itens alimentares fornecidos a éfiras, identificando a melhor dieta para esta fase e desenvolvimento da espécie e, assim, contribuindo para a optimização da sua aquacultura. 9 Tanques foram montados onde éfiras foram alimentadas com 3 dietas diferentes em cada 3 replicados – 3 replicados foram alimentadas com náuplios de Artémia enriquecida, 3 foram alimentados com copépodes Acartia grani enriquecidos com Rhodomonas sp. e os últimos e foram alimentadas com Aurélia aurita triturada. O principal objetivo foi identificar a dieta que se traduziu em crescimento máximo de éfiras de Chrysaora quinquecirrha por um período de 31 dias (com 10 éfiras por tanque com tamanho e idade idênticos) pulsações de éfiras foram monitorizadas diariamente e não houve diferenças significativas entre éfiras cultivadas com diferentes dietas, revelando que todas as presas revelaram uma resposta de alimentação semelhante. No entanto, as taxas de crescimento foram significativamente diferentes para éfiras alimentadas com as diferentes dietas. A dieta que resultou em maiores taxas de crescimento das éfiras consistiu em Aurélia aurita triturada (± DP 2,6 milímetros ao longo de 31 dias), seguido pela dieta de copépodes (± DP 1,8 milímetros ao longo de 31 dias) e finalmente a dieta baseada em náuplios de Artémia (± DP 1,08 milímetros ao longo de 31 dias). Este estudo recomenda que o suplemento dietético com copépodes ou Aurélia aurita triturada é um melhoramento importante na gestão da cultura de éfiras de Chrysaora quinquecirrha, e que as taxas de crescimento podem ser aumentadas de 83,1% a 128,6% (Acartia grani) e de 185,7% (Aurélia aurita) quando em comparação com a dieta tradicional