Browsing by Issue Date, starting with "2006-07"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
- Post-embryonic remodelling of neurocranial elements: a comparative study of normal versus abnormal eye migration in a flatfish, the Atlantic halibutPublication . Saele, O; Silva, Nadia; Pittman, KThe process of eye migration in bilaterally symmetrical flatfish larvae starts with asymmetrical growth of the dorsomedial parts of the ethmoid plate together with the frontal bones, structures initially found in a symmetrical position between the eyes. The movement of these structures in the future ocular direction exerts a stretch on the fibroblasts in the connective tissue found between the moving structures and the eye that is to migrate. Secondarily, a dense cell population of fibroblasts ventral to the eye starts to proliferate, possibly cued by the pulling forces exerted by the eye. The increased growth ventral to the eye pushes the eye dorsally. Osteoblasts are deposited in the dense cell layer, forming the dermal part of the lateral ethmoid, and at full eye migration this will cover the area vacated by the migrated eye. When the migrating eye catches up with the previous migrated dermal bones, the frontals, these bones will be remodelled to accommodate the eye. Our findings suggest that a combination of extremely localized signals and more distant factors may impinge upon the outcome of the tissue remodelling. Early normal asymmetry of signalling factors may cascade on a series of events.
- Evaluation of oil composition of some crops suitable for human nutritionPublication . Carvalho, Isabel Saraiva de; Miranda, I.; Pereira, H.Interest in Canola, Cannabis, Sunflower, Cardoon and Safflower, was focused on the composition of the fat because of their growing importance for nutritional and pharmaceutical purposes. We have therefore begun the analysis and characterization of their fatty acids (FAs) in different oils extracted from those crops to obtain reliable data on their suitability for both human nutrition and industrial or pharmaceutical purposes. The oil content fluctuated from 243 g/kg for Cardoon, 327 g/kg for Cannabis, 358 g/kg for Safflower, 411 g/kg for Sunflower to 488 g/kg for Canola. The ratio of n-6 to n-3 and total unsaturated to total saturated fatty acids ranged from 1.8 to 78.6 and 4.0 to 12.9, respectively. All five crop oils contained a high concentration of unsaturated fatty acids, namely linoleic acid (LA) and linolenic acid (LNA), which are two of the main representative compounds, known as dietary essential fatty acids (EFA) because they prevent deficiency symptoms and cannot be synthesized by humans. They could be considered, per si, functional foods without any biochemical extra additions. Thus, we conclude that whole crop oils do not differ significantly in their FAs composition; consequently, all seem to be suitable for human nutrition after refined procedure.
- Bioerosive structures of sclerozoan foraminifera from the lower pliocene of southern Spain: a contribution to the palaeoecology of marine hard substrate communitiesPublication . Santos, A; Mayoral, EA palaeoecological study of sclerozoan foraminifera of the families Saccamminidae (aff. Sagenina), Lituolidae (Placopsilina), Cibicididae (Cibicides, Dyocibicides, Cibicidella) and Planorbulinidae (Planorbulina and Planorbulinella) that colonized epifaunal bivalves (ostreids and pectinids) during the early Pliocene in southern Spain has led to the recognition of two new boring ichnogenera: Camarichnus ichnogen. nov., with two ichnospecies, C. subrectangularis ichnosp. nov. and C. arcuatus ichnosp. nov., and Canalichnus ichnogen. nov., with one ichnospecies, C. tenuis ichnosp. nov. The first two ichnospecies were produced by adnate lituolids and cibicidids, the last by saccamminids. Their recognition is very important when quantifying populations of these organisms. Colonisation took place after death of the host bivalves, when they acted as very stable substrates whose topography probably controlled the initial settlement pattern of the foraminifera. The colonisation sequence started with the foraminifera (lituolids-saccamminids-cibicidids-planorbulinids) and was followed by vermetid gastropods, serpulids, spirorbids, cheilostome bryozoans and/or ostreids. Preferred orientations and over-growth relationships between cheilostome bryozoans and serpulids have been detected in this material.
- A emergência da leitura e da escrita: práticas educativas em jardim de infânciaPublication . Luz, Odete Maria Loureiro Catarino da; Sousa, Maria Fernanda Ribeiro Botelho deA presente dissertação pretende contribuir para a compreensão do modo como os educadores de infância privilegiam práticas educativas que contribuam para a emergência da leitura e escrita nas crianças em idades pré-escolar. Procurámos fazer interpretações com carácter reflexivo onde o aprofundamento dos Modelos Curriculares, seguidos pelos educadores de infância participantes neste estudo, a apropriação das Orientações Curriculares e a Gestão de Currículo permitiram um quadro teórico e conceptual mais consistente. O estudo de caso múltiplo apresentado fundamenta-se nas narrativas construídas através de entrevistas a quatro educadores de infância, tornando visíveis as práticas educativas na emergência da leitura e da escrita, correlacionando-as com os Modelos Pedagógicos com os quais estes profissionais sustentam as suas práticas. Como opções metodológicas, utilizámos o estudo de caso, para nos dar a conhecer as formas qualitativamente diferentes, com que estes educadores entendem, conceptualizam e vivenciam as suas experiências. O instrumento de investigação de que nos servimos foi a entrevista semi-directiva, porque nos permitiu recolher os seus testemunhos e fazer interpretações com carácter reflexivo, respeitando os seus quadros de referência. Tratados os dados e analisados os resultados, concluímos que estes educadores de infância desenvolvem práticas emergentes de leitura e escrita, nas crianças em idade pré-escolar. Concluímos ainda que a assumpção consciente de um modelo curricular contribui para uma maior consciência das referências teóricas, provocando uma intencionalidade e um construto científico que sustentam as práticas dos educadores que os utilizam. Parece-nos concluir que o modelo preconizado pelo Movimento da Escola Moderna é O modelo curricular que, pela diversidade de instrumentos de leitura e escrita utilizados, pela sua dinâmica e pelo sistema de formação, onde a reflexão sobre a acção está sempre presente, mais contribui para a emergência da leitura e escrita nas crianças em idade pré-escolar.
- Blind estimation of the ocean acoustic channel by time-frequency processingPublication . Martins, N.; Jesus, S. M.A blind estimator of the ocean acoustic channel impulse response envelope is presented. The signal model is characterized by a deterministic multipath channel excited by a highly nonstationary deterministic source signal. The time–frequency (TF) representation of the received signal allows for the separation between the channel and the source signal. The proposed estimator proceeds in two steps: First, the unstable initial arrivals allow for the estimation of the source signal instantaneous frequency (IF) by maximization of the radially Gaussian kernel distribution; then, the Wigner–Ville distribution (WV) is sequentially windowed and integrated, where the window is defined by the previously estimated IF. The integral gives the channel impulse response envelope, which turns to be an approximation to the blind conventional matched filter (MF). The blind channel estimator (CE) is applicable upon the following conditions: that the multipath channel contains at least one dominant arrival well separated from the others, and that the IF of the source signal is a one-to-one function. Results obtained on real data from the INternal TIde Measurements with Acoustic Tomography Experiments (INTIMATE’ 96), where the acoustic channel was driven by an linear frequency modulation signal, show that the channel’s envelope detailed structure could be accurately and consistently recovered, with the correlation of the estimates ranging from 0.796 to 0.973, as compared to the MF result.
- Developing and implementing a strategy-driven performance management system in a higher education institutionPublication . Santos, Sérgio Pereira dos; Cândido, Carlos; Neely, A.; Kennerley, M.; Walters, A.Performance measurement in higher education has become a challenging issue over the past two decades. Increasingly, institutions of higher education have been required to develop performance measurement systems for both external reporting and internal management purposes. Despite this, little research has been documented regarding the application of the Balanced Scorecard in the education sector, especially at the departmental/faculty level. The objective of this paper is to contribute to filling this void by discussing the development of a performance management system, according to the principles of the Balanced Scorecard, in the Faculty of Economics of one of Portugal’s newer universities.
- The ground state water molecule and the reactions O(1D) + H2/D2/HD and H + OD that occur in this systemPublication . Rio, Carolina; Brandão, J.; Wang, WenliDue to their importance in atmospheric and combustion chemistry, the reactions of O(1D) with H2 and its isotopic variants HD and D2 have been subject of several theoret- ical1, 2 and experimental2, 3 studies.
- O coordenador pedagógico e o trabalho de equipa na creche: um estudo de caso múltiploPublication . Figueira, Sofia Gago da Silva Corrêa; Portugal, Maria Gabriela Correia de CastroO presente trabalho teve como grande motivação a consciência da actual situação das creches que em Portugal injustificadamente foram excluídas da Lei de Bases do Sistema Educativo, enquanto uma resposta educativa, e a quase inexistência de investigação acerca da educação e cuidados das crianças entre os zero e os três anos em creche. O presente trabalho tomou como referência três contextos diversificados de primeira infância (creches) e foi realizado através da abordagem qualitativa, tendo conduzido à formulação de um modelo compreensivo das práticas de coordenação pedagógica e o desenvolvimento do trabalho de equipa. Esse modelo procura condensar os dados que emergiram do processo analítico e dizem respeito às modalidades através das quais as coordenadoras dão significado às suas funções, às dificuldades que enfrentam, a forma como organizam o trabalho de equipa, bem como ao modo como acompanham as práticas educativas e apoiam as educadoras de infância.
- Molecular characterization and expression pattern of zona pellucida proteins in gilthead seabream (Sparus aurata)Publication . Modig, Carina; Modesto, Teresa; Canario, Adelino V. M.; Cerda, J.; Hofsten, Jonas von; Olsson, P. E.The developing oocyte is surrounded by an acellular envelope that is composed of 2–4 isoforms of zona pellucida (ZP) proteins. The ZP proteins comprise the ZP1, ZP2, ZP3, and ZPX isoforms. While ZP1 (ZPB) and ZP3 (ZPC) are present in all species, ZP2 (ZPA) is not found in teleost fish and ZPX is not found in mammals. In the present study, we identify and characterize the ZP1, ZP3 and ZPX isoforms of gilthead seabream. Furthermore, by analyzing the conserved domains, which include the external hydrophobic patch and the internal hydrophobic patch, we show that ZP2 and ZPX are closely related isoforms. ZP proteins are synthesized in either the liver or ovary of most teleosts. Only in rainbow trout has it been shown that zp3 has dual transcription sites. In gilthead seabream, all four mRNA isoforms are transcribed in both the liver and ovary, with zp1a, zp1b, and zp3 being highly expressed in the liver, and zpx being primarily expressed in the ovary. However, determination of the ZP proteins in plasma showed high levels of ZP1b, ZP3, and ZPX, with low or non-detectable levels of ZP1a. In similarity to other teleost ZPs, the hepatic transcription of all four ZP isoforms is under estrogenic control. Previously, we have shown that cortisol can potentiate estrogen-induced ZP synthesis in salmonids, and now we show that this is not the case in the gilthead seabream. The present study shows for the first time the endocrine regulation of a teleost ZPX isoform, and demonstrates the dual-organ transcriptional activities of all the ZP proteins in one species.