Browsing by Issue Date, starting with "2002"
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- Influências e efeitos dos SI/TI no desempenho profissionalPublication . Serrano, António; Sequeira, BernardeteInfluências e efeitos dos SI/TI no desempenho profissional.
- Osteological development and abnormalities of the vertebral column and caudal skeleton in larval and juvenile stages of hatchery reared solea senegalensis (kaup)Publication . Gavaia, Paulo J.; Dinis, Maria Teresa; Cancela, LeonorThe Senegal sole is a species recently adapted to aquaculture for which little information on larval development is available. This study was designed to describe normal skeletal development and the occurrence of skeletal malformations in Senegal sole reared in captivity. Eggs were collected from natural spawning, incubated until hatching and larvae reared to the juvenile stage in a closed recirculating system. Samples were collected throughout development at regular intervals from hatching to fully formed juveniles. Specimens were stained with alcian blue and alizarin red and observed for skeletal development and detection of anomalies. A high number of malformations were detected, both in the caudal complex and the vertebral column. About 44% of the individuals observed showed at least one malformation and the highest occurrence of deformities was observed in the caudal region and in the vertebral column. Accordingly, 28% of the total deformities identified in this study were detected at those sites and in adjacent arches and spines. The causes were not identified in this study, but the high incidence of malformations may reflect culture problems due to rearing and/or feeding conditions that affect skeletal development.
- A classical approach to TQFT’sPublication . Picken, Roger; Semião, PauloWe present a general framework for TQFT and related constructions using the language of monoidal categories. We construct a topological category C and an algebraic category D, both monoidal, and a TQFT functor is then defined as a certain type of monoidal functor from C to D. In contrast with the cobordism approach, this formulation of TQFT is closer in spirit to the classical functors of algebraic topology, like homology. The fundamental operation of gluing is incorporated at the level of the morphisms in the topological category through the notion of a gluing morphism, which we define. It allows not only the gluing together of two separate objects, but also the self-gluing of a single object to be treated in the same fashion. As an example of our framework we describe TQFT’s for oriented 2D-manifolds, and classify a family of them in terms of a pair of tensors satisfying some relations.
- pH adjustment for seasonal control of UF fouling by natural watersPublication . Ribau Teixeira, Margarida; Rosa, Maria JoãoNatural surface waters in Algarve, Portugal, have important seasonal variations in natural organic matter (NOM) content, that influences ultrafiltration (UF) performance. This paper addresses the evaluation of the pH adjustment for seasonal control of UF fouling at a laboratory scale, using a plate and frame polysulphone membrane of 47 kDa MWCO. Results of two types of natural water (clear water, 3-5 NTU, and turbid water, 33-34.6 NTU) and three different water pH values (acid, neutral and basic) demonstrated that the pH adjustment could be used for seasonal control of UF fouling: when the water has less NOM (in dry periods, clear water), the acid pH will improve the UF performance, while during and after intense rainfall periods (turbid water with high NOM concentration) basic pH will be advantageous, because it minimizes membrane fouling. This behaviour is explained for clear water in terms of charge effects on membrane size. For turbid water, the electrostatic repulsion between membrane surface and NOM and turbidity particles is reduced at pH 4.13 and protonation of the NOM functional groups decreases the hydrodynamic radii of humic substances while increasing their hydrophobicity and their tendency to adsorb. Therefore, a dense fouling layer develops and flux is lower at pH 4.13 than at pH 8.33. These results together with the observed raw water feed concentrations decline and rejection decrease with WRR confirm the extensive adsorption on the membrane enhanced by the moderate hardness cation of this water.
- Observations on some interesting coastal Crustacea Decapoda from the Azores, with a key to the genus Eualus Thallwitz, 1892 in the Northeastern Atlantic and the MediterraneanPublication . Udekem d'Acoz, Cédric d’; Wirtz, PeterRecords of several rare or interesting Crustacea Decapoda from the Azores are presented in the present paper. Periclimenes sagittifer and Athanas nitescens are recorded for the first time in the archipelago. Periclimenes sagittifer was found on various hydroids and the antipatharian Antipathes wollastoni, some juveniles being also found amongst algae. Athanas nitescens was encountered free-living and in a shell inhabited by the hermit crab Dardanus calidus. Comparative illustrations are given for Azorean Periclimenes sagittifer and French specimens. New characters are proposed to distinguish Eualus cranchii, E. drachi, E. occultus and E. pusiolus, and a key to Northeastern Atlantic and Mediterranean Eualus species is provided. Azorean specimens of Hippolyte varians prove to be especially small and slender, whilst Azorean Stenopus spinosus may have red, white or even proximally red and distally white antennae. The association between the hermit crab Nematopagurus longicornis and the antipatharian Antipathes wollastoni is recorded for the first time. A possibly undescribed Macropodia species is here recorded and illustrated as Macropodia sp., as only juvenile and damaged adult specimens were found. Azorean Portunus hastatus prove to be much less pubescent than their Mediterranean counterparts, and detailed drawings are given for this common but rarely comprehensively illustrated species.
- Calcitonin: characterisation and expression in a teleost fish, Fugu rubripesPublication . Clark, M. S.; Bendell, L. A.; Power, Deborah; Warner, S.; Elgar, Greg; Ingleton, P. M.The present report describes the structure and expression of the calcitonin gene in Fugu rubripes. It is composed of 4 exons and 3 introns. Splicing of exons 1, 2 and 3 generates the calcitonin pre-proprotein, while splicing of exons 1, 2 and 4 generates calcitonin gene-related protein (CGRP). Exons 1 and 2 encoding the signal sequence and the N-terminal peptide are common in both the gene products and this gene organisation has been conserved in human, rat, chicken and salmon. The gene environment around calcitonin in Fugu has been poorly conserved when compared with human, apart from a small gene cluster. The calcitonin gene in Fugu has a widespread tissue distribution but it is most highly expressed in the brain. The abundance of gene expression in the ultimobranchial gland and the pituitary indicates that these are important sites of production and that the peptide is probably secreted into the circulation and/or acts as a paracrine or autocrine controlling factor. Whilst the function of calcitonin in fish is still largely unknown, the distribution described here suggests that one of the potential functions may be as a neuropeptide.
- Estudo do devir das rejeições ao mar com um veículo de operações remota (ROV)Publication . Carnall, Vera Marques; Andrade, Francisco A. de L.A pesca de arrasto de crustáceos é uma actividade piscatória que produz grandes quantidades de descargas ao mar - rejeições, constituídas por espécies sem valor comercial. Sabe-se que o volume do material rejeitado é muito elevado, mas pouco ou nada se sabe quanto ao seu devir a partir do momento em que “desaparece” na coluna de água. É de esperar que uma grande proporção deste material morto atinja o fundo, ficando disponível para os necrófagos bentónicos, não se conhecendo os seus efeitos sobre as comunidades bentónicas. Pretendeu-se com o presente trabalho estudar o devir do material rejeitado ao mar pela pesca industrial de arrasto de crustáceos, utilizando uma abordagem em situação real, através da simulação, em condições controladas, da largada ao mar de material “rejeitado” e seu fornecimento às comunidades bentónicas, em áreas alvo de arrasto de crustáceos. A utilização de um veiculo de operação remota (ROV - “Remoteiy Operated Vehicie”) permitiu um estudo directo e em tempo real, pois está equipado com uma câmara de vídeo, ligada, através de um umbilical à unidade de superfície, onde as imagens são visualizadas. Com o objectivo de estudar o processo de afundamento do material rejeitado, foi efectuado um conjunto de experiências de acompanhamento com o ROV do afundamento de simulacros de rejeição, desde o momento em que foram largados à superfície. Em 19 casos foi possível fazer o seu acompanhamento até profundidades superiores a 50 m e em 6, até ao fundo - a profundidades entre 95 e 213 m.
- Fuentes textuales árabes sobre Trujillo, en el Garb al-AndalusPublication . Viguera Molins, María JesúsCreo interesante y útil iniciar una serie, a la cual todos y acada uno de nosotros podemos seguir contribuyendo, reuniendo las referencias textuales sobre un determinado lugar, como fichas de trabajo, que, si persistimos en ir completando la serie, pueden llevarnos a formar un fichero de enclaves andalusíes representados a través de los textos árabes. Para esta ocasión, he elegido presentar y traducir los textos que he encontrado sobre Trujillo, hoy día perteneciente a Cáceres, en la Comunidad de Extremadura.
- A comparative study of the photophysics and photochemistry of 4-chlorophenol adsorbed on silicalite and beta-cyclodextrinPublication . Da Silva, José Paulo; Ferreira, Luís F. Vieira; Silva, Abílio M. da; Oliveira, A. S.The photochemistry and photophysics of 4-chlorophenol (4-CP) were studied onto two model solid supports, silicalite and beta-cyclodextrin (beta-Cl)), using time resolved diffuse reflectance techniques and product degradation analysis. The results have shown that the photochemistry and photophysics of 4-CP are different from solution and depend on the solid. Ground state diffuse reflectance and time resolved luminescence demonstrated the inclusion of the probe in both substrates. 4-CP exhibits room temperature luminescence in both hosts, being structured and much more intense in beta-CD. The emission was assigned to phosphorescence of the inclusion complex. Transient absorption demonstrated the formation of the unsubstituted phenoxyl radical and of 4-chlorophenoxyl radical in beta-CD. In silicalite only the later was detected. The studies of the photodegradation products indicate that phenol is the main photoproduct in beta-CD. In silicalite the chromatographic analysis indicates the presence of products that involve the ring cleavage. (C) 2002 Elsevier Science B.V. All rights reserved.
- Vibrational spectra and structure of 1-phenyltetrazole and 5-chloro-1-phenyltetrazolePublication . Bugalho, Susana C. S.; Lapinski, L.; Cristiano, Maria Lurdes Santos; Frija, L.; Fausto, R.Infrared spectra of 1-phenyltetrazole (C7N4H6) and 5-chloro-1-phenyltetrazole (C7N4H5Cl) isolated in argon matrixes (T ¼ 8 K) and in the solid state (at room temperature) were studied. DFT(B3LYP)/6-31G* calculations predict the minimum energy conformation of 1-phenyltetrazole as being non-planar, with the two rings (phenyl and tetrazole) twisted by 298. For 5-chloro-1- phenyltetrazole, the optimized dihedral angle between the two rings is larger (488). The theoretically calculated IR spectra of both compounds fit well the spectra observed experimentally. This allowed a reliable assignment of observed IR absorption bands.