Browsing by Issue Date, starting with "2010-09"
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- Life history of the common pandora, Pagellus erythrinus (Linnaeus, 1758) (Actinopterygil: Sparidae) from southern PortugalPublication . Coelho, Rui; Bentes, Luis; Correia, Carla; Gonçalves, Jorge Manuel Santos; Lino, Pedro; Monteiro, Pedro; Ribeiro, Joaquim; Erzini, KarimThe common pandora, Pagellus erythrinus, is a commercially important seabream for coastal fisheries in the north and central eastern Atlantic. Age, growth and reproductive aspects of the southern Portuguese population were estimated by analysing 386 specimens ranging in total length (TL) from 12.0 to 44.8 cm. Ages were estimated by counting growth bands on otoliths and verified by marginal increment analysis, with specimens ranging in age from 1 to 21 years. The von Bertalanffy growth function was selected as the most adequate model to fit this species' growth, with the estimated parameters being L-inf = 47.14 cm TL, k = 0.084 year(-1) and t(0) = - 4.42 year. The gonads were analyzed macroscopically over a one-year period and the reproductive spawning season found to occur from March to July. The length at first maturity for males occurs at 17.58 cm TL and 1.15 years while females mature at slightly smaller sizes (17.29 cm TL) and younger ages (1.04 years). The results presented in this study are important for comparing this population's parameters with those of other populations of the same species occurring in other areas, as well as for future studies, for assessing eventual changes in population parameters over time.
- No tempo em que se faziam revoluções de chapéu de coco e bigodes carbonáriosPublication . Carmo, Carina Infante doAo percorrermos a cronologia da obra de José Gomes Ferreira, torna-se evidente que a narrativa da vida e a composição do auto-retrato de artastista acentuaram, em crescendo,a força temática da infância.
- Fractional integrals and hypersingular integrals in variable order Holder spaces on homogeneous spacesPublication . Samko, Natasha; Samko, Stefan; Vakulov, BorisWe consider non-standard Holder spaces H(lambda(.))(X) of functions f on a metric measure space (X, d, mu), whose Holder exponent lambda(x) is variable, depending on x is an element of X. We establish theorems on mapping properties of potential operators of variable order alpha(x), from such a variable exponent Holder space with the exponent lambda(x) to another one with a "better" exponent lambda(x) + alpha(x), and similar mapping properties of hypersingular integrals of variable order alpha(x) from such a space into the space with the "worse" exponent lambda(x) - alpha(x) in the case alpha(x) < lambda(x). These theorems are derived from the Zygmund type estimates of the local continuity modulus of potential and hypersingular operators via such modulus of their densities. These estimates allow us to treat not only the case of the spaces H(lambda(.))(X), but also the generalized Holder spaces H(w(.,.))(X) of functions whose continuity modulus is dominated by a given function w(x, h), x is an element of X, h > 0. We admit variable complex valued orders alpha(x), where R alpha(x) may vanish at a set of measure zero. To cover this case, we consider the action of potential operators to weighted generalized Holder spaces with the weight alpha(x).
- Inovação organizacional: a eficácia do método de resolução criativa de problemasPublication . Cardoso de Sousa, Fernando; Monteiro, Ileana PardalEste estudo procura demonstrar a eficácia do método de Resolução Criativa de Problemas (RCP) na melhoria das preferências face ao pensamento divergente e na implicação com a equipa, bem como na gestão do conhecimento. Equipas de RCP, num primeiro grupo de sete empresas (48 participantes) e num segundo de três (41), foram objecto de um «pre-post» teste de preferências face ao pensamento divergente e, apenas no segundo grupo, a uma escala de implicação para com o grupo. Os factos registados durante as sessões foram categorizados e sujeitos a análise factorial de correspondências. Os resultados revelam uma mudança favorável ao pensamento divergente e um aumento da implicação emocional com o grupo. Da mesma forma, a análise dos factos demonstrou que as empresas possuem orientações diferentes quanto à natureza da inovação, conforme a especificidade da situação. A generalização destes resultados ao nível
- A literatura e a república: Manuel Teixeira-GomesPublication . Carvalho, Ana Alexandra Mendonça Seabra da Silva Andrade deEvocação de Manuel Teixeira-Gomes: biografia breve; os percursos na política e na literatura; o carácter original da sua prosa: as facetas do viajante-esteta e ultrassensorial.
- Are the portuguese regions converging to a single steady state?Publication . Andraz, Jorge Miguel; Norte, NéliaThis paper is concerned with examining the economic performance of the Portuguese regions Nuts III. In particular, it seeks to present empirical evidence about the degree of convergence in their economic performance since 1990 when regions became the recipients of the European Community Structural Funds. Panel data regressions are estimated and the results suggest structural differences among regions leading to the existence of different steady state levels of income. Moreover, regions are converging to different steady states at an annual rate of 2.15%. As a corollary, results suggest that national policies, while contributing to improving the country's living standards relative to the European average, might not have been able to achieve the economic cohesion of the country.
- Assessing equilibrium clear water scour around single cylindrical piersPublication . Lança, Rui; Fael, Cristina; Cardoso, AntónioThe objective of this research is to investigate the pertinence of existing approaches to assess the onset of the equilibrium phase of scour at single cylindrical piers in experimental studies. The results of five long-lasting experiments are reported. The discussion has profusely shown that common methods used to decide on whether a given scour experiment has reached the equilibrium phase may be erroneous. It has also shown that known predictors of time to equilibrium may imply significantly wrong predictions of equilibrium depth. Finally, it seems that, typically, 7 days-long scour depth records adjusted though a 6-parameters polynomial function and extrapolated to infinite time render robust vales of the equilibrium scour depth at single cylindrical piers.
- The possible origin of Zostera noltii in the Canary Islands and guidelines for restorationPublication . Diekmann, O. E.; Gouveia, Licínia; Perez, J. A.; Gil-Rodriguez, C.; Serrão, EsterSeagrasses and their habitat are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly by anthropogenic disturbance, to three small surviving patches in a single harbor in Lanzarote. A previous genetic study, using neutral microsatellite markers, revealed that these patches consist of a single clonal individual. Here, an assignment test, using microsatellite data, was used to locate the most likely population of origin from a set of possible donor populations. Our results show that the Moulay Bousselham population in northern Morocco is assigned as the most likely population of origin (88%), although the probability of being at one generation time distance is low (2.7%). This result, however, allows locating the most closely related stands that may be the most successful donor populations for future restoration based on shoot or seed transplantation.
- Light absorption by particulate and dissolved organic matter in coastal and oceanic off the South west coast of Europe: a contribution to MERIS sensor validationPublication . Goela, Priscila; Cristina, Sónia; Icely, John; Newton, AliceThe two variable components of light absorption, which are important contributors to the correct adjustments of ocean colour algorithms, are considered and discussed in this study, conducted in the Southwest coast of Portugal; these are particulate absorption – separated into phytoplankton and non-algal particles absorption, and coloured dissolved organic matter absorption, expressed in terms of their coefficients – ap(), aph(), anap() and aCDOM(), respectively. This study is part of a global effort to collect data to validate marine products of MERIS, the ENVISAT ocean colour sensor, as contracted by European Space Agency (ESA). Particulate absorptions were determined with Transmittance-Reflectance approach, using NaClO bleaching to remove phytoplankton contribution to the total particulate matter absorption spectra; YSBPA absorption coefficient was assessed according to MERIS validation protocols. Phytoplankton absorption coefficients were transformed into specific coefficients – a*ph(), normalizing it with respect to chlorophyll a concentrations determined both by HPLC and spectrophotometric methods. Results show that the absorption of light by particulate matter is almost totally dependent on the phytoplankton, with no significant contribution from non-algal particles (mean contribution of 10% to total particulate absorption), both in coastal and oceanic waters, emphasising the dominance of case 1-type waters. Specific chlorophyll absorption coefficients show significant fluctuations between seasons and stations, ranging from 0.007 to 0.09 at 678 nm; however, a good correlation between ap(443) and ap at other MERIS equivalent wavelengths was found. Particulate matter has generally more weight than dissolved matter absorption in the total absorption budget. These results may contribute to improve and correct regional ocean colour algorithms.