Browsing by Issue Date, starting with "2008-09"
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- Teacher scripts in biologyPublication . Monteiro, Rute; Carrillo, José; Aguaded, S.Understanding teaching implies an understanding of the thinking and action of the teacher (Shulman, 1986), this leading to a fuller understanding when these two domains are studied together and each is examined in relation to the other. There are several ways to understand the teacher’s thought and action. For instance the teaching modelisation (Schoenfeld, 1998, Monteiro, 2006) enables the study of teacher’s thoughts from its cognition (believes, knowledge, goals) and actions, which in turn are derived from scripts, acting altogether.
- Sebenta prática do Método dos DeslocamentosPublication . Barreto, Vítor; Costa, RuiEsta sebenta apresenta a aplicação do Método dos Deslocamentos na resolução de problemas de pórticos planos. Nesse propósito apresentam-se os desenhos dos modos de deformação e sistematiza-se o cálculo manual. Na primeira parte os exercícios estão resolvidos, na segunda enunciam-se exercícios e apresentam-se as soluções e na terceira parte apresentam-se exercícios de provas de avaliação efectuadas nos anos anteriores.
- Health-related quality of life in patients with Rheumatoid ArthritisPublication . Ferreira, Lara; Ferreira, Pedro Lopes; Baleiro, RitaObjectives: Rheumatoid arthritis (RA) is a chronic rheumatic disease of unknown aetiology and greater incidence among the elderly. It can lead to serious consequences regarding functional limitations and patient's ability to work. The purpose of this study was to assess the health-related quality of life in patients with RA. Methods: Portuguese version of SF-6D and Portuguese translations of EQ-5D and AIMS2-SF were self-administered in a postal survey to a representative sample of the Portuguese population with RA. Data concerning the patients' characteristics and the stage of the disease were also collected. Results: The majority of the patients presented minor problems in some of the instruments' dimensions. In a scale from 0.30 to 1.00, the average utility score was 0.77. The lowest utility scores were reported by women, those who were divorced or separated, individuals with lower educational levels, who had lower incomes, were recently diagnosed and those who were not taking new biological therapies. Apart from these, patients who had a more severe RA and co-morbidity also report lower utility scores. Conclusions: The preference-based utility measures used in this study adequately discriminate across different RA severity and socio-demographic background. Assuming that these values represent the patients' preferences and the utility associated with their health state, the results presented in this paper may be used as an approximation to normative values for the SF-6D in economic evaluation studies as well as in clinical studies.
- Listeria monocytogenes biofilm-associated protein (BapL) may contribute to surface attachment of L-monocytogenes but is absent from many field isolatesPublication . Jordan, Suzanne J.; Perni, Stefano; Glenn, Sarah; Fernandes, Isabel; Barbosa, Manuela; Sol, Manuela; Tenreiro, Rogerio P.; Chambel, Lelia; Barata, Belarmino; Zilhao, Isabel; Aldsworth, Timothy G.; Adrião, Andreia Lúcia Gonçalves; Faleiro, L; Shama, Gilbert; Andrew, Peter W.Listeria monocytogenes is a food-borne pathogen capable of adhering to a range of surfaces utilized within the food industry, including stainless steel. The factors required for the attachment of this ubiquitous organism to abiotic surfaces are still relatively unknown. In silico analysis of the L. monocytogenes EGD genome identified a putative cell wall-anchored protein (Lmo0435 [BapL]), which had similarity to proteins involved in biofilm formation by staphylococci. An insertion mutation was constructed in L. monocytogenes to determine the influence of this protein on attachment to abiotic surfaces. The results show that the protein may contribute to the surface adherence of strains that possess BapL, but it is not an essential requirement for all L. monocytogenes strains. Several BapL-negative field isolates demonstrated an ability to adhere to abiotic surfaces equivalent to that of BapL-positive strains. BapL is not required for the virulence of L. monocytogenes in mice.
- PACemakers of proteasome core particle assemblyPublication . Ramos, Paula C.; Dohmen, R. JuergenThe 26S proteasome mediates ubiquitin-dependent proteolysis in eukaryotic cells. A number of studies including very recent ones have revealed that assembly of its 20S catalytic core particle is an ordered process that involves several conserved proteasome assembly chaperones (PACs). Two heterodimeric chaperones, PAC1-PAC2 and PAC3-PAC4, promote the assembly of rings composed of seven alpha subunits. Subsequently, P subunits join to form half-proteasome precursor complexes containing all but one of the 14 subunits. These complexes lack the beta 7 subunit but contain UMP1, another assembly chaperone, and in yeast, at least to some degree, the activator protein Blm10. Dimerization of two such complexes is triggered by incorporation of beta 7, whose C-terminal extension reaches out into the other half to stabilize the newly formed 20S particle. The process is completed by the maturation of active sites and subsequent degradation of UMP1 and PAC1-PAC2.
- Effects of salt stress on purslane (Portulaca oleracea) nutritionPublication . Teixeira, Monica; Carvalho, Isabel Saraiva deThe objective of this study was to determine the influence of saline stress on the chemical composition of purslane (Portulaca oleracea), in particular the mineral composition. Four salinity levels were investigated using irrigation solutions with electrical conductivity values of 0.8, 6.8, 12.8 and 24.2 dS m−1 and two planting dates (May and July) were tested. Samples of full-grown leaf and stems of purslane were harvested after 7 and 15 days of the saline treatment exposure. Chemical analysis (dry matter basis) of leaves showed significant differences among the different saline treatments for all the characteristics measured. Salinity levels, planting date and harvest time significantly influenced (P < 0.05) the levels of crude protein, total lipids, ash and carbohydrate content. Salinity treatments did not significantly (P > 0.05) affect the water content of purslane leaves. The crude protein content of purslane leaves decreased with increasing salinity levels and time of exposure to treatment. However, carbohydrates and mineral residue content increased. An unusual phenomenon was noted for intermediate salinity levels, whereby an increase in total lipid content was measured in leaves of plants exposed to salinity treatments of 6.8 and 12.8 dS m−1. The highest mineral residue content was seen in leaves of purslane exposed to the highest salinity treatment. The mineral composition was also affected by salinity levels, Na and Cl uptake, and accumulation increased with increasing salinity in irrigation solution; Mg concentration was not significantly (P > 0.05) affected by salinity levels, although a slight increase was seen, and Ca, K and Zn levels significantly (P < 0.05) decreased. Ca and Zn preferentially accumulated in the leaves, while K and Na values were higher in the stems. A significant increase (P < 0.05) in relative ratio of Na/K, Mg/K, Na/Ca and Mg/Ca was observed with increasing salinity levels. A decrease in the yield of purslane was only observed for the most severe saline treatment, where the highest ratio of Mg/Ca was seen. This study reveals that purslane is relatively tolerant to conditions of moderate salinity, thus improving its potential to become a key vegetable crop for animal and human consumption.
- A discussão da qualidade nos canais culturais públicos: o caso de A2: PortuguesaPublication . Borges, GabrielaEste trabalho apresenta a elaboração de um modelo teórico com parâmetros para a análise da qualidade dos programas de televisão dos canais culturais públicos, com enfoque no estudo de caso da A2: portuguesa. Os parâmetros de qualidade são definidos para cada uma das áreas de actuação da A2:, nomeadamente as áreas cultural, social, infanto-juvenil, educativa e jornalística. Estes consideram as funções gerais a serem desempenhadas para o cumprimento da missão de serviço público de televisão, as funções específicas definidas na Lei da Televisão e no Contrato de Concessão Especial de Serviço Público de 2003, assim como os indicadores de qualidade definidos para a análise dos Planos da Expressão, do Conteúdo e da Mensagem Audiovisual dos programas de cada uma das áreas.
- A mosca-do-mediterrâneo na citricultura AlgarviaPublication . Duarte, AmilcarA mosca-do-mediterrâneo (Ceratitis capitata) é uma praga presente no nosso país desde finais do séc. XIX. Ela ataca mais de 250 espécies de fruteiras, incluindo algumas das mais cultivadas em Portugal.
- Assessment of pollution along the Northern Iberian shelf by the combined use of chemical and biochemical markers in two representative fish speciesPublication . Fernandes, D; Andreu-Sánchez, Oscar; Bebianno, Maria João; Porte, CintaMuscle concentrations of organochlorinated compounds as well as biliary levels of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APEs) were determined in two different fish species, the four-spotted megrim (Lepidorhombus boscii) and the pouting (Trisopterus luscus) collected along the Northern Iberian coast. Additionally, a set of biochemical markers namely, 7-ethoxyresorufin O-deethylase (EROD), UDP-glucuronosyltransferase (UGT) and catalase (CAT) were measured in liver subcellular fractions. Chemical analysis indicated geographical differences in pollutant loads that were further reinforced by biomarker responses. Thus, EROD activity showed a good correlation with the amount of PCBs bioaccumulated in muscle tissue of both fish species. Elevated UGT activity was observed in those individuals highly exposed to APEs and 1-naphthol. The study reinforces the need to select representative sentinel species from different habitats for biomonitoring purposes and provides further support for the use of biomarkers in assessing the health of coastal areas.
- Influence of the sign of the coupling on the temperature dependence of optical properties of one-dimensional exciton modelsPublication . Cruzeiro, LeonorA new physical cause for a temperature-dependent double peak in exciton systems is put forward within a thermal equilibrium approach for the calculation of optical properties of exciton systems. Indeed, it is found that one-dimensional exciton systems with only one molecule per unit cell can have an absorption spectrum characterized by a double peak provided that the coupling between excitations in different molecules is positive. The two peaks, whose relative intensities vary with temperature, are located around the exciton band edges, being separated by an energy of approximately 4V, where V is the average coupling between nearest neighbours. For small amounts of diagonal and off-diagonal disorder, the contributions from the intermediate states in the band are also visible as intermediate structure between the two peaks, this being enhanced for systems with periodic boundary conditions. At a qualitative level, these results correlate well with experimental observations in the molecular aggregates of the thiacarbocyanine dye THIATS and in the organic crystals of acetanilide and N-methylacetamide.