Browsing by Issue Date, starting with "2009-09"
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- Seasonal movements of veined squid Loligo forbesi in Scottish (UK) watersPublication . Viana, Mafalda; Pierce, Graham J.; Illian, Janine; MacLeod, Colin D.; Bailey, Nick; Wang, Jianjun; Hastie, Lee C.In order to protect and sustainably manage fishery resource species, it is essential to understand their movements and habitat use. To detect the hypothesised migration of maturing veined squid Loligo forbesi from the west coast of Scotland (UK) to the North Sea and identify possible inshore-offshore movements, we analysed seasonal, spatial and environmental patterns in abundance and size distribution, based on commercial fishery landings data and trawl survey data from Scottish coastal waters (International Council for the Exploration of the Sea, ICES areas IVa, IVb and VIa). A geographic information system (GIS) was used to build monthly contour maps of abundance. Generalised additive mixed models (GAMM) were used to quantify patterns in size distribution and abundance. In most years, there was no evidence of movement from the West to the East coast of Scotland. Evidence of inshore-offshore movements during the life-cycle of the cohort that recruits in autumn (winter breeders) was found instead. The winter breeding cohort appears to spawn in inshore waters and some evidence suggests that the spawning grounds of the summer breeders are also inshore. Across seasons, higher abundance of L. forbesi can generally be found in the north of Scotland at intermediate water depths and in warmer waters.
- Desenvolvimento de sistemas celulares de peixe adequados ao estudo da mineralização in vitroPublication . Marques, C. L.; Rafael, Marta S.; Tiago, Daniel; Cancela, Leonor; Laizé, VincentOs peixes foram recentemente reconhecidos como organismos modelo apropriados para o estudo da biologia de vertebrados, particularmente de processos relacionados com a mineralização tecidular e o desenvolvimento do esqueleto. Apesar de existirem alguns estudos in vivo, a identificação de mecanismos associados à calcificação em peixes tem sido prejudicada pelo facto de não existirem sistemas celulares para estudos in vitro. Este artigo descreve um protocolo simples e de baixo custo adequado ao desenvolvimento de culturas celulares mineralogénicas, derivadas de tecidos calcificados de peixes.
- E-CRM and CMS systems: potential for more dynamic businessesPublication . Fernandes, Silvia BritoAny change in customer’s behaviour affects the customer’s value. In addition, profitability and economic viability also change. Most companies still do not know entirely their customer base characteristics. They find difficult to define criteria that segment their customer base to find high-value customers. They need to focus on target selections to carry on with marketing campaigns which involve high investments. Given the potential of e-CRM and CMS as powerful tools to guide customer-oriented understanding and analysis, greater attention is required. Several companies, operating within the same business and having access to the same information and technology, differ in e-CRM performance. Without sufficient evidence, managers are prone to making investment decisions that are neither efficient nor effective. So it is imperative to base the decision of e-CRM and CMS adoption, on not only their analytical power, but also on economic viability criteria for sustainable business dynamics
- Effect of cold chain temperature abuses on the quality of frozen watercress (Nasturtium officinale R. Br.)Publication . Cruz, R. M. S.; Vieira, M. M. C.; Silva, C. L. M.The objective of this work was to study the effect of temperature abuses on the colour and vitamin C content of a new frozen vegetable, watercress (Nasturtium officinale R. Br.). The vitamin C content, expressed as ascorbic (AA) and dehydroascorbic (DHAA) acids, and colour, expressed in the Hunter Lab parameters, were evaluated along a plan of temperature abuses, based on a real situation for a four month frozen storage period. A comparison between the hue angle and AA experimental data and prediction models, using kinetic parameters determined under isothermal conditions, was also run. The colour showed some variation, namely on the parameters L, a, TCD (Total Colour Difference) and hue angle. Although, during the temperature abuses, some fluctuation was observed, no vitamin C degradation or major colour changes occurred. A zero-order and a first-order prediction models fitted well the experimental data for the hue angle and AA behaviour with temperature abuses, respectively. In general, the frozen watercress colour and vitamin C content were not impaired by the imposed temperature abuses. This work will help to predict and understand the sensory and nutritional quality changes of frozen watercress that might occur during frozen storage and distribution in the cold chain under the used conditions.
- Os scripts como elementos de reflexão para professores de ciências.Publication . Monteiro, Rute; Carrillo, José; Aguaded, S.Neste trabalho analisa-se a prática de dois professores no seu primeiro ano de exercício profissional através do Instrumento de Modelação (IM), que permite caracterizar os seus guiões de acção ou scripts. O script corresponde a uma entidade teórica que permite compreender uma sequência de acções estandardizada, dependente do conteúdo de ciências. A incorporação de elementos à prática de ensino do professor terá que passar por um questionamento e análise contínuos e contextualizados do seu ensino. Deste modo, a reflexão sobre os scripts torna-se essencial para a melhoria do ensino.
- Catalytic epoxidation and sulfoxidation activity of a dioxomolybdenum(VI) complex bearing a chiral tetradentate oxazoline ligandPublication . Neves, Patrícia; Gago, Sandra; Pereira, Cláudia C. L.; Figueiredo, Sónia; Lemos, Americo; Lopes, Andre D.; Gonçalves, Isabel S.; Pillinger, Martyn; Silva, Carlos M.; Valente, Anabela A.A dioxomolybdenum(VI) complex bearing a tetradentate anionic N,O oxazoline ligand with four stereocenters has been studied as a catalyst in the liquid-phase epoxidation of 17 different aliphatic and aromatic olefins(including prochiral, racemate or pure enantiomers) using tert-butyl hydroperoxide as the oxidant. Epoxide selectivities of up to 100% and variable epoxide yields (3–100% within 24 h) were obtained. Although the complex generally exhibited low or no chiral induction ability, diastereoselectivity was significant in some cases (in the reaction of limonene, for example). Kinetic studies and recycling tests with the substrates cis-cyclooctene and trans-b-methylstyrene showed that the catalyst is stable and reusable, and recycling is facilitated by immobilization of the complex in a room temperature ionic liquid. Preliminary results show that the complex may have a broad substrate scope, not only for olefin epoxidation, but also for the dehydrogenation of alcohols to carbonyl compounds and the sulfoxidation of sulfides to sulfoxides.
- Strategy implementation rate of failure – a research agendaPublication . Cândido, Carlos; Santos, Sérgio Pereira dosNumerous estimates have been made of failure rates on strategy implementation and on new management methods implementation. These estimates have been used as evidence to propose and to dismiss many new strategies and business management methods. A review of the literature reveals that current estimates can vary from 10% to 90% and that these are frequently based on evidence that is either outdated, fragmentary, fragile, or just absent. Careful consideration is therefore advised before using these estimates to promote changes in the theory and/or practice of strategic management. This research intends to provide a more reliable estimate of the rate of failure on strategy implementation by considering the contextual factors that affect it. The research further intends to study whether relationships between obstacles affect strategy implementation and whether the guidelines for implementation provided in the literature have improved implementation success rates.
- Concepções de professores do 1º ciclo do ensino básico: o que eles declaram antes de abordarem o conceito de evaporação no âmbito do PFEECPublication . Dionísio Gonçalves, Carla Alexandra Lourenço Duarte Rocha; Barros, Jorge; Monteiro, RuteEste estudo tem por base, parte de uma investigação efectuada por um grupo de professores de vários níveis escolares: professores do 1º, 2º e 3º Ciclos do Ensino Básico (CEB) e do Ensino Superior. O principal propósito deste estudo foi analisar as concepções declaradas de oito professores do 1º CEB, participantes, pela primeira vez, no Programa de Formação de Professores do 1º CEB em Ensino Experimental das Ciências (PFEEC). O estudo foi realizado antes dos professores abordarem a temática Mudanças de Estado Físico no âmbito do PFEEC, centrando-se no ensino do conceito de Evaporação. Para se efectuar a análise dos documentos redigidos pelos professores, contemplando as suas concepções declaradas (designados por Radiografias da Prática), foi utilizado um Instrumento de Análise das Concepções dos Professores de Ensino Básico, no âmbito das Ciências da Natureza, de acordo com Monteiro (2006) e Monteiro et al. (2008). Neste estudo foram encontrados perfis de 5 professores manifestando uma tendência maioritariamente Espontaneísta, um exibido um perfil maioritário Tradicional e outro apresentando um perfil mais Tecnológico.
- Genetic recolonization of mangrove: Genetic diversity still increasing in the Mekong delta 30 years after Agent OrangePublication . ARNAUD-HAOND, Sophie; Duarte, C. M.; Teixeira, Sara; Massa, S. I.; Terrados, J.; Tri, N. H.; Hong, P. N.; Serrão, EsterThe widespread use of Agent Orange (a mixture of phenoxyl herbicides) over Southern Vietnam by US Forces led to the decimation of mangrove forests in the Mekong Delta. Mangrove trees Avicennia alba were sampled across the Mekong Delta; their age was assessed using models based on internode growth and samples were genotyped for 6 microsatellite loci. The evolution of genetic diversity over time elapsed since local extinction was reconstructed and compared with the genetic diversity of an unaffected population from Thailand. The results show that genetic diversity of the A. alba population is still increasing in the Mekong Delta 3 decades after the end of the Vietnam War, but is reaching an asymptotic level that is comparable to the adjacent non-affected population of Thailand. This might be a sign of genetic recovery, but may also reveal a limitation, either of genetic enrichment due to current predominance of auto-recruitment or of demographic increase due to intraspecific competition in this pioneer species. In any case, these results, although encouraging, demonstrate that genetic recovery after complete or almost complete population depletion continues over a longer time-scale than apparent demographic recovery.