Diel vertical migration of decapod larvae in the Portuguese coastal upwelling ecosystem: implications for offshore transport

The vertical distribution of decapod larvae off the northwest Portuguese coast was analysed in relation to associated environmental conditions from sampling during a 69 h period around a current meter mooring located on the shelf, approximately 21 km off the coast. Plankton samples were collected every 2 h at the surface with a neuston net and through the water column with a Longhurst Hardy Plankton Recorder (Pro-LHPR), allowing a very detailed resolution of larval vertical distribution. Environmental data (temperature, salinity, and chlorophyll a) were obtained every hour. To investigate the horizontal distribution of decapod larvae in relation to the coast, a plankton-sampling grid was carried out before the 69 h fixed station. Larvae of shelf decapod species were widely distributed over the shelf, while those of inshore species were found much closer to the coast. Decapod larvae (zoeae and megalopae) showed clear diel vertical migrations, only appearing in the upper 20 m at night, a migration that did not appear to be affected by physical conditions in the water column. Larval densities were highly variable, 0.01 to 215 ind. m super(-3) for zoeae and 0 to 93 ind. m super(-3) for megalopae, the zoeae being generally more abundant. The results indicated that during the day larvae accumulate very close to the bottom. The diel vertical migration behaviour is discussed as one of the contributing mechanisms for larval retention over the shelf, even with offshore transport conditions promoted by coastal upwelling, and is hence of major relevance for the recruitment success of decapod species that inhabit inshore and shelf zones of coastal upwelling systems.

Horizontal and vertical distribution of cirripede cyprid larvae in an upwelling system off the Portuguese coast

The distribution of cirripede cyprids in relation to associated oceanographic conditions was obtained from a grid survey and intensive vertical sampling at a fixed station located 21 km off the northwest Portuguese coast in May 2002. Analysis of cyprid length composition allowed separation of 3 species groups. Chthamalus montagui, Pollicipes pollicipes and Balanus perforatus were largely restricted to the neuston layer and showed only low-amplitude vertical migration. Most C. stellatus cyprids only appeared in the upper 20 m at night, a migration which did not appear to be affected by physical conditions in the water column, but some differences in the vertical migration pattern between days were probably related to varying light penetration. C. montagui is the most abundant adult species found along the Portuguese coast, but C. stellatus cyprids, at densities of up to 8.7 ind. m–3, were the most common sampled in all depth strata at the fixed station. Cyprid horizontal distribution was mainly restricted to an offshore band along the inner shelf, where highest densities were 11 to 15 ind. m–3. This distribution pattern was considered to result from upwelling-favourable wind conditions, creating fronts along the shelf in which the cyprids become concentrated. Cyprid vertical migration, in association with current vertical shear and onshore movement of fronts during upwelling-relaxation periods, may be the mechanisms returning cyprids to the coast to settle. The regularity of these events in the region falls within the period of cyprid viability.

The Violent Maintenance of the Portuguese Colonial Identity and the Search for a Postcolonial one: literary images of Portugal as a colonial and postcolonial nation

Through the examination of Camões's Os Lusíadas , Sena's Os Grão-Capitães and Saramago's A Jangada de Pedra , this article explores violence as a means of shaping Portuguese identity in different historical contexts, and how these works portray the continued recourse to violence as Portugal moves from colonizing to postcolonial nation.

Validity, trustworthiness and rigour:reasserting realism in qualitative research

Aim The aim of this paper is to challenge recent sceptical approaches to the possibility of validating qualitative research and to underline the benefits of adopting a realist approach to validity. Background In recent discussion about the methodological bases for qualitative research it has been argued that, because different methodologies take different approaches to validity, attempts to develop a common set of validation criteria are futile. On the basis of this sceptical view, a number of strategies for judging qualitative research have been proposed. These include suggestions that: it should be judged according to aesthetic or rhetorical criteria, rather than epistemological validity; responsibility for appraisal should move from researchers to readers; each methodology should be assessed individually according to its own merits. Discussion None of these suggestions provide a viable alternative to validity, defined as the extent to which research reflects accurately that to which it refers. Because the form of research does not determine its content, replacement of epistemology by aesthetics is unsustainable. Because research reports mediate between writer and reader, a one-sided approach to this relationship constitutes a false dichotomy. If we accept the criterion of practitioner confidence as a means of judging methodological approaches, this involves rejection of judgement according to a methodology�s own merits. Conclusion If qualitative research is actually about something, and if it is required to provide beneficial information, then a realist approach to validity holds out greatest promise.

Failure of Local Realism Revealed by Extremely-Coarse-Grained Measurements

We show that failure of local realism can be revealed to observers for whom only extremely-coarse-grained measurements are available. In our instances, Bell's inequality is violated even up to the maximum limit while both the local measurements and the initial local states under scrutiny approach the classical limit. Furthermore, we can observe failure of local realism when an inequality enforced by nonlocal realistic theories is satisfied. This suggests that locality alone may be violated while realism cannot be excluded for specific observables and states. Small-scale experimental demonstration of our examples may be possible in the foreseeable future.

The conflict between realism and abstraction in the field of spanish art as an iteration of la "Querelle des Anciens et des Modernes"

Based on the analysis model favored by the study of the conditions in which the seventeenth century Querelle des Anciens et des Modernes took place, we examine the case of confrontation between realism and abstraction, which occurred in the context of Spanish art in the nineties of the twentieth century. Connections are established with other aesthetic conflicts which are considered part of a genealogy whose most explicit antecedent could be placed in the before mentioned complaint, such as the confrontation between realism and abstraction in the American art scene, which occurred in the fifties of the last century, and the more recent controversy on pluralism and the end of art.

Testing nonlocal realism with entangled coherent states

We investigate the violation of nonlocal realism using entangled coherent states (ECSs) under nonlinear operations and homodyne measurements. We address recently proposed Leggett-type inequalities, including a class of optimized incompatibility inequalities proposed by Branciard et al. [Nature Phys. 4, 681 (2008)], and thoroughly assess the effects of detection inefficiency.