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- Response of a multi-domain continental margin to compression: study from seismic reflection-refraction and numerical modelling in the Tagus Abyssal PlainPublication . Neves, Maria; Terrinha, P.; Afilhado, A.; Moulin, Anne M; Matias, L.; Rosas, F.The effects of the Miocene through Present compression in the Tagus Abyssal Plain are mapped using the most up to date available to scientific community multi-channel seismic reflection and refraction data. Correlation of the rift basin fault pattern with the deep crustal structure is presented along seismic line IAM-5. Four structural domains were recognized. In the oceanic realm mild deformation concentrates in Domain I adjacent to the Tore-Madeira Rise. Domain 2 is characterized by the absence of shortening structures, except near the ocean-continent transition (OCT), implying that Miocene deformation did not propagate into the Abyssal Plain, In Domain 3 we distinguish three sub-domains: Sub-domain 3A which coincides with the OCT, Sub-domain 3B which is a highly deformed adjacent continental segment, and Sub-domain 3C. The Miocene tectonic inversion is mainly accommodated in Domain 3 by oceanwards directed thrusting at the ocean-continent transition and continentwards on the continental slope. Domain 4 corresponds to the non-rifted continental margin where only minor extensional and shortening deformation structures are observed. Finite element numerical models address the response of the various domains to the Miocene compression, emphasizing the long-wavelength differential vertical movements and the role of possible rheologic contrasts. The concentration of the Miocene deformation in the transitional zone (TC), which is the addition of Sub-domain 3A and part of 3B, is a result of two main factors: (1) focusing of compression in an already stressed region due to plate curvature and sediment loading; and (2) theological weakening. We estimate that the frictional strength in the TC is reduced in 30% relative to the surrounding regions. A model of compressive deformation propagation by means of horizontal impingement of the middle continental crust rift wedge and horizontal shearing on serpentinized mantle in the oceanic realm is presented. This model is consistent with both the geological interpretation of seismic data and the results of numerical modelling. (C) 2008 Elsevier B.V. All rights reserved.
- CibersexoPublication . Silva, BrunoAs comunidades virtuais proporcionam anonimato e privacidade, formando espaços lúdicos ideais para a experimentação sexual. Estes laboratórios virtuais possibilitam a recriação, interpretação e aniquilação de todos os tabus. O cibersexo aparece, assim, como uma opção válida, tendo em conta o risco de contaminação de doenças infecto-contagiosas e outras complicações que possam advir do sexo casual. Esta é uma das principais características do sexo virtual: fisicamente é totalmente seguro. Psicologicamente pode provocar decepção, ultraje e, até, um grau elevado de dependência. Numa relação real (resultante da dinâmica entre virtual [paixão ou amor] e actual [encontro físico]) a pessoa apaixona-se por si própria e não pela outra. Apaixona-se pelo seu próprio poder de sedução e capacidade de envolvimento. Nos casos de paixão virtual, ou melhor de ciber-paixão, essa relação de si para si, onde o outro surge apenas enquanto pretexto, é exacerbada pela mediação tecnológica. Entre tele-enamorados não existe contacto directo, contacto físico, com a suposta pessoa amada, dando uma nova dimensão ao facto da paixão acontecer enquanto mero reflexo. Os tele-enamorados não se apaixonam por um indivíduo, apaixonam-se por uma sensação. Numa ciber-relação, não importa a idade ou a aparência física, só o tele-contacto, os momentos de prazer proporcionados pelo parceiro virtual independentemente dos seus defeitos ou dos seus problemas. Uma vez que o tele-enamorado constrói uma imagem de si próprio e do seu parceiro virtual, a ciber-relação poderá tornar-se mais intensa que uma relação do mundo físico. É a relação perfeita, no limiar da fantasia.
- Segmentation and fishery characteristics of the mixed-species multi-gear portuguese fleetPublication . Duarte, Rafael; Azevedo, Manuela; Afonso-Dias, ManuelFleet segmentation and knowledge of fishing fleet dynamics are essential to move from single species to fishery/fleet-based advice. The coastal mixed-species multi-gear Portuguese fleet comprises medium-sized (> 12m) vessels, using a diversity of passive gears, and is economically important. For hake (under a recovery plan) and monkfish (overexploited), it contributes > 50% to their total annuel landings. Commercial daily landings in 2005 from 271 vessels were analysed by region using non-hierarchical cluster analysis and multi-variate regression trees. The cluster analysis allowed the identification of regional fleet segments with a low mixture of species through-out the year. The multivariate regression trees were applied to clusters of vessels with a high mixture of species, to explain weekly landing profiles (species) by vessel technical characteristics, fishing license, and main landing port. The results showed a link between exploited species and geographic location, and in the north between vessel size and depth and an inshore/offshore range. Finally, from the analysis and for the most important species exploited by the Portuguese multi-gear fleet, it was possible to define two or three vessel groups that accounted for at least 50% of the landed value.
- Diplodus spp. assemblages on artificial reefs: importance for near shore fisheriesPublication . Azevedo Leitão, F. Marina; Santos, M. N.; Erzini, Karim; Monteiro, C. C.Artificial reefs have been deployed along the southern coast of Portugal (Algarve) since 1990 to enhance artisanal fisheries. The objectives of this study were to: (1) describe the colonisation process; (2) assess the role of the artificial reefs in terms of juvenile recruitment and growth and as mating/spawning areas and (3) evaluate the potential of artificial reefs as near shore artisanal fishing grounds for three economically important fish species, Diplodus bellottii (Steindachner), Diplodus sargus (L.) and Diplodus vulgaris (Geoffroy Saint-Hilaire). The fish assemblages were monitored after the deployment of a large artificial reef (Faro/Ancao) in 2002. Colonisation rates for the three species were fast. Artificial reefs play a multiple role for Diplodus spp., acting as recruitment, growth and nursery areas for juveniles, and spawning/mating areas for adults, and can thus be considered essential fish habitat. Three months after deployment of the artificial reefs, exploitable biomass was 16, 29 and 8 kg per reef group, respectively, for D. bellotti, D. sargus and D. vulgaris. These results indicate that artificial reefs quickly become good fishing grounds, where suitable financial yields may be obtained by fisher. Moreover, the artificial reefs became new and alternative fishing grounds, allowing reduction of fishing effort over traditional rocky areas that are scarce along the Algarve coast. Management measures for artificial reefs, in terms of fishing strategies, are discussed.
- Operators of harmonic analysis in weighted spaces with non-standard growthPublication . Kokilashvili, V. M.; Samko, StefanLast years there was increasing an interest to the so-called function spaces with non-standard growth, known also as variable exponent Lebesgue spaces. For weighted such spaces on homogeneous spaces, we develop a certain variant of Rubio de Francia's extrapolation theorem. This extrapolation theorem is applied to obtain the boundedness in such spaces of various operators of harmonic analysis, such as maximal and singular operators, potential operators, Fourier multipliers, dominants of partial sums of trigonometric Fourier series and others, in weighted Lebesgue spaces with variable exponent. There are also given their vector-valued analogues. (C) 2008 Elsevier Inc. All rights reserved.
- Deep water longline selectivity for black spot seabream (Pagellus bogaraveo) in the Strait of GibraltarPublication . Czerwinski, Ivone Alejandra; Gutierrez-Estrada, Juan Carlos; Erzini, Karim; Hernando, José AntonioSpecies and size selectivity of the deep water longline traditionally used in commercial fishing of the black spot seabream (Pagellus bogaraveo) were studied in the Strait of Gibraltar with four sizes of hooks. Black spot seabream contributed up to 88% of the catch by number. Catch and by-catch rates differed for the different hooks and fishing trials. Significant differences in average fish length between all hooks, except in one case, were found. The comparison of two experimental fishing trials within 4 years indicates a displacement towards smaller sizes in the size frequency distributions. The results of this study show that the fishing gear can be size selective depending on hook size. The fitted selectivity models for each experiments were very different despite having two hooks in common. This is probably due to the very different catch size distributions in the two periods, which suggests that the population size structure changed significantly between 2000/2001 and 2004/2005.