Browsing by Issue Date, starting with "2013"
Now showing 1 - 10 of 474
Results Per Page
Sort Options
- Pedagogia, tecnologia e cultura democrática: que sentidos fazem na escola pública atual?Publication . Brazão, José Paulo Gomes
- Chemical composition, fatty acids profile and cholesterol content of commercialized marine fishes captured in Northeastern AtlanticPublication . Nogueira, Natacha; Cordeiro, Nereida; Aveiro, Maria JoãoInformation available on the chemical composition and nutritional value of commercialized marine fish is very limited. The aim of this study was to investigate major nutrients of raw fish muscle and liver. Protein, moisture ash and lipid content were estimated for 14 commercialized species captured in Northeastern Atlantic. Proximate compositions were found to be varied among the studied species. Cluster analysis revealed two major groups based on proximate composition. Pontinus kuhlii and Trachurus picturatus formed one group, while the second group was formed by ten other species. Protein content was high in all species, varying between 18.51% in Phycis phycis and 32.69 % in Diplodus sargus. Fat content, on the other hand, was low and fish could be considered lean (lipid content <4%). Muscle fatty acid compositions consisted of 26.2-35.8% saturated fatty acids (SFA), 10.5-37.6% monounsaturated fatty acids (MUFA) and 28.7-57.5% polyunsaturated fatty acids (PUFA). Fish livers presented lower amounts of PUFA’s than muscles, mainly due to a reduction of the docosahexaenoic acid (DHA) content. Cholesterol content in liver revealed significant differences, ranging from 0.05 ±0.01 mg/g in Scorpaena scrofa to 7.58 ±0.19 mg/g in Aphanopus carbo. In fish muscle, cholesterol was low and was not correlated with lipids, fatty acids or PUFA content of the muscle.
- As comunidades ópticas: uma análise das redes sociais digitais a partir do seu regime ópticoPublication . Mateus, SamuelUm dos factores de atractividade e sucesso das redes sociais digitais parece consistir na constante visualização dos perfis públicos e na observação das múltiplas fotografias e vídeos que os integram. Embora nem sempre associadas à sua visualidade constitutiva, as redes sociais digitais baseiam-se num exacerbamento do regime óptico. Na presente reflexão iremos considerar a importância da escopofilia para o estudo das sociabilidades online sublinhando dois aspectos fundamentais: por um lado, as redes sociais digitais como o Facebook, o Twitter ou o Orkut colocam os seus usuários não apenas como “amigos” entre si, como também como espectadores das suas próprias aparências. Por outro lado, é através desta relação visual que se estabelece entre indivíduos que as redes sociais digitais parecem insinuar-se como comunidades ópticas capazes de redefinir as formas contemporâneas da pertença social.
- Microextraction using packed sorbent as an effective and high-throughput sample extraction technique: recent applications and future trendsPublication . Pereira, J.; Gonçalves, J.; Alves, V.; Câmara, J. S.In the last decade, several developments, particularly in the liquid chromatography and hyphenated techniques fields, have allowed researchers to reach analytical limits that are becoming very close to the single molecule level. Sample preparation, however, despite being a key step in the analytical methodology, did not track these developments and very few approaches able to cope with these stringent analytical requirements were developed. One such approach is microextraction by packed sorbent (MEPS), a sophisticated and miniaturized form of solid phase extraction that has reduced to the microliter scale every step of the sample extraction methodology including sample volume and solvent usage. Simultaneously, the amount of extraction phase used was also reduced and, more importantly, the sorbent is reusable dozens of times which significantly lowers the cost of analysis versus other solid-phase extraction approaches. In this review, we will update the state-of-the-art of the MEPS technique, focusing on the trends and applications reported since 2010 and future perspectives and developments that in our view will further improve the high-throughput potential and applications of this sample preparation methodology.
- A devoção mariana no diálogo português do BarrocoPublication . Nascimento, Maria TeresaCom Fr. Amador Arrais, primeiro, com João Rebelo, depois, através da multiplicidade de micro-narrativas milagrosas, ou ainda com Brito Alão, no caso particular de Nossa Senhora da Nazaré, o diálogo português havia já sido expressão de devoção mariana. A Miscelânea de Miguel Leitão de Andrada, publicada em 1629, prosseguindo na es teira desta vertente religiosa do diálogo, confirma o hibridismo genológico do género que, se na anterior produção portuguesa não passara despercebido, agora supera essa propensão. Temas e formas conjugam-se para fazer desta obra um dos mais criativos diálogos publicados até à altura.
- A micro-extraction technique using a new digitally controlled syringe combined with UHPLC for assessment of urinary biomarkers of oxidatively damaged DNAPublication . Mendes, Berta Rodrigues; Silva, Pedro; Aveiro, Fernando; Pereira, Jorge; Câmara, José S.The formation of reactive oxygen species (ROS) within cells causes damage to biomolecules, including membrane lipids, DNA, proteins and sugars. An important type of oxidative damage is DNA base hydroxylation which leads to the formation of 8-oxo-7,8-dihydro-29-deoxyguanosine (8-oxodG) and 5-hydroxymethyluracil (5-HMUra). Measurement of these biomarkers in urine is challenging, due to the low levels of the analytes and the matrix complexity. In order to simultaneously quantify 8-oxodG and 5-HMUra in human urine, a new, reliable and powerful strategy was optimised and validated. It is based on a semi-automatic microextraction by packed sorbent (MEPS) technique, using a new digitally controlled syringe (eVolH), to enhance the extraction efficiency of the target metabolites, followed by a fast and sensitive ultrahigh pressure liquid chromatography (UHPLC). The optimal methodological conditions involve loading of 250 mL urine sample (1:10 dilution) through a C8 sorbent in a MEPS syringe placed in the semi-automatic eVolH syringe followed by elution using 90 mL of 20% methanol in 0.01% formic acid solution. The obtained extract is directly analysed in the UHPLC system using a binary mobile phase composed of aqueous 0.1% formic acid and methanol in the isocratic elution mode (3.5 min total analysis time). The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), extraction yield, accuracy, precision and matrix effect. Satisfactory results were obtained in terms of linearity (r2 . 0.991) within the established concentration range. The LOD varied from 0.00005 to 0.04 mg mL21 and the LOQ from 0.00023 to 0.13 mg mL21. The extraction yields were between 80.1 and 82.2 %, while inter-day precision (n=3 days) varied between 4.9 and 7.7 % and intra-day precision between 1.0 and 8.3 %. This approach presents as main advantages the ability to easily collect and store urine samples for further processing and the high sensitivity, reproducibility, and robustness of eVolHMEPS combined with UHPLC analysis, thus retrieving a fast and reliable assessment of oxidatively damaged DNA.
- Formal methods for privacy aware social networkingPublication . Hanvey, Sorren Cristopher; Cataño Collazos, Néstor
- Curriculum studies in Europe: future directionsPublication . Sousa, Jesus Maria
- Evaluation of the potencial of Vitis vinifera L. grapes used to produce Madeira wine: impact of winemaking processPublication . Perestrelo, Rosa Maria de Sá; Câmara, José Sousa; Carriço, Sílvia Maria da Rocha Simões
- Understanding the limitations of eco-feedback: a one-year long-term studyPublication . Pereira, Lucas; Quintal, Filipe; Barreto, Mary; Nunes, Nuno J.For the last couple of decades the world has been witnessing a change in habits of energy consumption in domestic environments, with elec tricity emerging as the main source of energy consumed. The effects of these changes in our eco-system are hard to assess, therefore encouraging researchers from different fields to conduct studies with the goal of understanding and im proving perceptions and behaviors regarding household energy consumption. While several of these studies report success in increasing awareness, most of them are limited to short periods of time, thus resulting in a reduced knowledge of how householders will behave in the long-term. In this paper we attempt to reduce this gap presenting a long-term study on household electricity consump tion. We deployed a real-time non-intrusive energy monitoring and eco feedback system in 12 families during 52 weeks. Results show an increased awareness regarding electricity consumption despite a significant decrease in interactions with the eco-feedback system over time. We conclude that after one year of deployment of eco-feedback it was not possible to see any significant increase or decrease in the household consumption. Our results also confirm that consumption is tightly coupled with independent variables like the house hold size and the income-level of the families.