Browsing by Issue Date, starting with "2011-01"
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- Shell strength and fishing damage to the smooth clam (Callista chione): simulating impacts caused by bivalve dredgingPublication . Vasconcelos, Paulo; Morgado-Andre, Antonio; Morgado-Andre, Carlos; Gaspar, MiguelThe smooth clam Callista chione is exploited by a fleet of dredgers along the southwestern coast of Portugal and suffers from a high incidence of shell damage. The force required to break C. chione shells in relation to fishing impacts and dredge damage is quantified. Fishing trials and shell-strength measurements (compression and compaction experiments) were performed to determine whether shell damage was attributable to the direct impact of the dredge teeth or to sediment compaction. A three-dimensional model of C. chione was subjected to simulated force by the finite element method. Analyses of damage areas and breakage patterns revealed two groups of samples, one containing the samples from compression experiments and another with the samples from dredging and compaction experiments, suggesting that most shell damage was attributable to compaction within the sediment. Information is provided to help improve the design of bivalve dredges, by increasing both length and angle of the dredge teeth, which would reduce the compaction force and distribute it differentially within the sediment, forcing upward movement of the bivalves.
- Sulfated polysaccharides in marine sponges: extraction methods and anti-HIV activityPublication . Esteves, Ana I. S.; Nicolai, Marisa; Humanes, Madalena; Gonçalves, JoãoThe extraction, fractionation and HIV-1 inhibition potential of polysaccharides extracted from three species of marine sponges, Erylus discophorus, Cliona celata and Stelletta sp., collected in the Northeastern Atlantic, is presented in this work. The anti-HIV activity of 23 polysaccharide pellets and three crude extracts was tested. Crude extracts prepared from Erylus discophorus specimens were all highly active against HIV-1 (90 to 95% inhibition). Cliona celata pellets showed low polysaccharide content (bellow 38.5%) and almost no anti-HIV activity (<10% inhibition). Stelletta sp. pellets, although quite rich in polysaccharide (up to 97.3%), showed only modest bioactivity (<36% HIV-1 inhibition). Erylus discophorus pellets were among the richest in terms of polysaccharide content (up to 98%) and the most active against HIV-1 (up to 95% inhibition). Chromatographic fractionation of the polysaccharide pellet obtained from a specimen of Erylus discophorus (B161) yielded only modestly active fractions. However, we could infer that the active molecule is most probably a high molecular weight sulfated polysaccharide (>2000 kDa), whose mechanism is possibly preventing viral attachment and entry (fusion inhibitor).
- Spatial strategic interaction on public expenditures of the Northern Portuguese Local GovernmentsPublication . Barreira, Ana PaulaThe existence of spatial strategic interaction between neighbouring local governments is often referred in literature and identified in empirical applications for several countries. This interaction can occur either in expenditures or revenues of local governments. The spatial interaction in local government expenditure finds support on three theoretical explanations: spillover effects, Tiebout competition or mimicking behaviour. Identify the adequate explanation for the local government interaction is not an easy task since the reduced form of the estimated model can generate indistinguishable pattern in spatial interactions. This paper seeks to identify between those theoretical explanations what is the underlying reason for spatial interaction in public expenditures among local governments for the case of a particular sub-area of Portugal. Using differentiated model configurations and the local government expenditures of the municipalities composing the Northern Portuguese mainland, between 1998 and 2008, the paper identifies the structural model that generates the observed spatial auto-correlation in local public expenditures. Among the various theoretical reasons, only the existence of spillovers effects finds support.
- The discursive construction of place-identity: british lifestyle migrants in the AlgarvePublication . Torkington, KateThis thesis takes an interdisciplinary, critical discourse analysis (CDA) approach to investigate the discursive construction of place-identity. For the purposes of this research, place-identity is understood as the relationship between the discursive construction of place and the discursive construction of the multiplicities of the individual and collective self. The main data is provided by interviews with British lifestyle migrants in the Algarve, Portugal. I develop a framework for investigating both the individual and the collective dimensions of migrant place-identity by combining elements from Systemic Functional Linguistics (in particular Appraisal theory) and Cognitive Linguistics. This allows an analysis of both strategic features of the micro-level of discourse, such as evaluation of place(s), and apparently less conscious features, such as the use of spatial deixis. I draw on Positioning Analysis as a means of linking micro- and macrolevels of analysis. At the micro-level, the findings suggest that various modes of belonging are constructed in interaction by positioning the self as being attitudinally aligned (or not) with place(s) and by positioning the self as being (literally and metaphorically) inside/outside place(s). The macro-level context of the research is the growing contemporary trend of lifestyle migration, which is strongly related to tourism mobilities. Since this social phenomenon is fertile ground for the production of privileged, elite identities, one of the aims of this thesis is to expand the agenda of CDA research by developing an understanding of how such privileged identities are articulated, (re)produced, reinforced and negotiated through discursive positionings, and how these positionings are linked to hegemonic discourses that ‘legitimise’ certain types of migration. The study thus aims to show how the discursive construction of place-identity is not only an integral part of the discursive construction of migrant identities, but also how place-identity is linked to broader ideologies and contributes to the politics of place.
- “(In)verosímil e fantástico ou a arte de provocar o medo”Publication . Carvalho, Ana Alexandra Mendonça Seabra da Silva Andrade deFilho do Iluminismo, o fantástico recusa igualmente a inverosimilhança do maravilhoso e a verosimilhança aristotélica do Classicismo ou do Realismo. Real e irreal entrelaçam-se, originando perturbação, mistério e angústia. Privada de Deus, a realidade humana é percepcionada como enigmática e inquietante. Para provocar no leitor o efeito da angústia e do medo, o fantástico assenta na ambiguidade da apresentação do fenómeno meta-empírico, inserindo, num quadro real verosímil, algo de escandalosamente inverosímil que instaura o paradoxo nos quadros de referência do mundo conhecido. Como explicar o sucedido? As respostas de Crébillon, Baudelaire ou Maupassant aqui tratadas serão diferentes. Contudo, depois de Todorov, aceita-se que o maravilhoso crê no sobrenatural, a ficção científica desenvolve uma fantasia baseada nos poderes racionais da ciência e o estranho encontra uma solução racional. No fantástico – construído a partir da incerteza e da ambiguidade – devem permanecer a hesitação, a perplexidade, a angústia e o medo.
- A emergência da cidade-providência enquanto conquista da emancipação social urbanaPublication . Sousa, Vanessa Duarte deEste ensaio procura discutir o desenho inicial de um quadro analítico para a cidade-providência emergente, que permanece no quadro dessas invisibilidades referenciadas. Num primeiro momento, é empreendida uma reflexão de contextualização sobre a crise da cidade, identificação das suas fragmentações, das suas segregações. Trata-se de analisar o contexto empírico concreto em que se criam as condições para essa cidade-providência.
- A criação do reconhecimento de adquiridos experienciais (RVCC) em Portugal - uma etnografia critica em educação de adultosPublication . Barros, RosannaNesta monografia dedicar-nos-emos à análise e interpretação dos dados resultantes de uma investigação empírica aprofundada, cujo objectivo transversal visou a compreensão de como são e como se processam as lógicas de acção na governação subnacional da educação e formação de adultos. Assim, atendendo às múltiplas especificidades do contexto português cujo panorama sócio-histórico de políticas públicas para o sector emitiu, em apenas três décadas, distintos mandatos e suscitou, como vimos noutro lugar (ver Barros, 2009a), um considerável hibridismo de orientações no que que concerne ao modo de produção de politicas sociais, torna-se ainda mais pertinente, do ponto de vista analítico, considerar que a dimensão politica de todas as decisões em educação apresenta uma "topografia complexa" (cf. Lima, 1999a: 77), na qua não se pode ignorar que existe para além do nível estatal a possível "capacidade de intervir na formulação das políticas e, depois, ainda a capacidade de traduzir as políticas de formas distintas" (Lima, 1998d:23). Na medida em que as práticas locais podem desencadear processos de construção efectiva e de reconstrução simbólica das decisões político-administrativas centrais, e dadas as características do sistema nacional de RVCC recentemente introduzido no panorama educacional português, interessou-nos procurar os possíveis dilemas que se colocam a um certo tipo de associativismo, com tradição reconhecida de intervenção crítica em educação de adultos, na exploração, deliberada ou não da sua própria margem relativa de acção, cujo potencial consiste na possibilidade de contrariar certa orientações de política.
- Fine-scale spatial genetic structure and gene dispersal in Silene latifoliaPublication . Barluenga, M.; Austerlitz, F.; Elzinga, J. A.; Teixeira, S.; Goudet, J.; Bernasconi, G.Plants are sessile organisms, often characterized by limited dispersal. Seeds and pollen are the critical stages for gene flow. Here we investigate spatial genetic structure, gene dispersal and the relative contribution of pollen vs seed in the movement of genes in a stable metapopulation of the white campion Silene latifolia within its native range. This short-lived perennial plant is dioecious, has gravity-dispersed seeds and moth-mediated pollination. Direct measures of pollen dispersal suggested that large populations receive more pollen than small isolated populations and that most gene flow occurs within tens of meters. However, these studies were performed in the newly colonized range (North America) where the specialist pollinator is absent. In the native range (Europe), gene dispersal could fall on a different spatial scale. We genotyped 258 individuals from large and small (15) subpopulations along a 60 km, elongated meta-population in Europe using six highly variable microsatellite markers, two X-linked and four autosomal. We found substantial genetic differentiation among subpopulations (global F(ST) = 0.11) and a general pattern of isolation by distance over the whole sampled area. Spatial autocorrelation revealed high relatedness among neighboring individuals over hundreds of meters. Estimates of gene dispersal revealed gene flow at the scale of tens of meters (5-30 m), similar to the newly colonized range. Contrary to expectations, estimates of dispersal based on X and autosomal markers showed very similar ranges, suggesting similar levels of pollen and seed dispersal. This may be explained by stochastic events of extensive seed dispersal in this area and limited pollen dispersal. Heredity (2011) 106, 13-24; doi:10.1038/hdy.2010.38; published online 14 April 2010
- The Jurassic (Pliensbachian to Kimmeridgian) palynology of the Algarve Basin and the Carrapateira outlier, southern PortugalPublication . Borges, Marisa; Riding, James B.; Fernandes, Paulo; Pereira, ZéliaThe palynology of the Jurassic (Upper Pliensbachian to Lower Kimmeridgian) fill of the Algarve Basin and the Carrapateira outlier, southern Portugal was investigated. Samples were collected from Armação Nova Bay, Mareta Beach, Cilheta Beach and the Carrapateira outlier. At Armação Nova Bay the Upper Pliensbachian–Lower Toarcian succession proved barren, or yielded sparse, non age-diagnostic palynomorphs. Dinoflagellate cysts are confined to the Upper Bajocian to Upper Callovian sedimentary rocks exposed at Mareta and Cilheta beaches and the Lower Kimmeridgian strata of the Carrapateira outlier. At Mareta Beach, the Upper Bajocian, Bathonian and Callovian produced relatively low to moderate diversity dinoflagellate cyst assemblages. Several key bioevents confirm the Bathonian and Callovian ages of the succession; no age-significant Late Bajocian bioevents were noted. The Upper Callovian of Cilheta Beach yielded moderately diverse dinoflagellate cyst associations dominated by Ctenidodinium spp. Key Late Callovian bioevents confirm the age of this succession. Many familiar marker forms known from northwest Europe were not encountered. No typically Arctic forms were recovered throughout the Upper Bajocian to Callovian of this part of the Algarve Basin. It is clear that there was no significant Late Bajocian to Late Callovian dinoflagellate cyst provincialism within southern and northern Europe and adjacent regions. The Carrapateira outlier yielded a moderately diverse Early Kimmeridgian dinoflagellate cyst flora. The Early Kimmeridgian age assessment based on corals and foraminifera is confirmed. Amphorula and Histiophora are present; these are typical of the Late Jurassic of the Tethyan Realm, and their presence is consistent with Late Jurassic provincialism within Europe. The relatively low diversity nature of these Late Bajocian to Early Kimmeridgian dinoflagellate cyst floras is probably mainly due to the relatively deep water, partially enclosed depositional setting. The partially enclosed nature of this part of the Algarve Basin and the Carrapateira outlier seems to have prevented the free migration of dinoflagellates between southern Portugal and elsewhere in Europe.
- Prevalence of resistance associated polymorphisms in Plasmodium falciparum field isolates from southern PakistanPublication . Ghanchi, Najia Karim; Ursing, Johan; Beg, Mohammad A.; Veiga, Maria I.; Jafri, Sana; Martensson, AndreasBackground: Scarce data are available on Plasmodium falciparum anti-malarial drug resistance in Pakistan. The aim of this study was, therefore, to determine the prevalence of P. falciparum resistance associated polymorphisms in field isolates from southern Pakistan. Methods: Blood samples from 244 patients with blood-slide confirmed P. falciparum mono-infections were collected between 2005-2007. Single nucleotide polymorphisms in the P. falciparum chloroquine resistance transporter (pfcrt K76T), multi drug resistance (pfmdr1 N86Y), dihydrofolate reductase (pfdhfr A16V, N51I, C59R, S108N, I164L) and dihydropteroate synthetase (pfdhps A436S, G437A and E540K) genes and pfmdr1 gene copy numbers were determined using PCR based methods. Results: The prevalence of pfcrt 76T and pfmdr1 86Y was 93% and 57%, respectively. The prevalence of pfdhfr double mutations 59R + 108N/51R + 108N was 92%. The pfdhfr triple mutation (51I, 59R, 108N) occurred in 3% of samples. The pfdhfr (51I, 59R, 108N) and pfdhps (437G, 540E) quintuple mutation was found in one isolate. Pfdhps 437G was observed in 51% and 540E in 1% of the isolates. One isolate had two pfmdr1 copies and carried the pfmdr1 86Y and pfcrt 76T alleles. Conclusions: The results indicate high prevalence of in vivo resistance to chloroquine, whereas high grade resistance to sulphadoxine-pyrimethamine does not appear to be widespread among P. falciparum in southern Pakistan.