Browsing by Issue Date, starting with "2012-09"
Now showing 1 - 10 of 25
Results Per Page
Sort Options
- Antioxidant and free radical scavenging activities of different plant parts from two Erica speciesPublication . Nunes, Ricardo; Anastácio, Ana; Carvalho, Isabel Saraiva deAqueous extractions from two species of Erica consumed as infusions in several countries to heal ailments were investigated for their phenolic and flavonoid contents, along with antioxidant capacity and radical scavenging capacity using total antioxidant activity, ferric-reducing antioxidant power, reducing power, 1,1-diphenyl-2-picrylhydrazyl and 2-2'-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) radicals, respectively. Antioxidant properties and total phenolic content differed significantly among these plants. Aqueous extracts of leaves possessed, on average, the highest antioxidant capacity and phenolic content (34.09 ± 10.81 mg ascorbic acid equivalent/g dry weight and 30.59 ± 10.19 mg gallic acid equivalent/g dry weight, respectively) of all three plant parts. A significant correlation (r2 = 0.952) between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants. Upon application of hierarchical cluster analysis to the results obtained, leaves with flowers were grouped in one cluster, whereas branches remained in another cluster, showing little interference from the collection site or species factors.
- Um olhar sobre uma competição matemática na Web: a resolução de problemas para além da sala de aulaPublication . Amado, Nélia; Carreira, SusanaEm Portugal, tal como em todo o mundo, o número de competições matemáticas tem aumentado, assumindo as mais diversas formas, conteúdos e durações e dirigindo-se a grupos de alunos cada vez mais alargados. São exemplos de competições bem conhecidas, as Olimpíadas Portuguesas de Matemática e as Olimpíadas Internacionais de Matemática, destinadas a alunos especialmente talentosos, acontecendo a par de outras como o concurso Canguru Matemático e os Campeonatos de Matemática SUB12 e SUB14 que, em contrapartida, têm um caráter marcadamente inclusivo, isto é, são abertos a alunos com diversos graus de aptidão para a resolução de problemas.
- Normal vector analysis from GNSS-GPS data applied to Deception volcano surface deformationPublication . Berrocoso, M.; Prates, Gonçalo; Fernandez-Ros, A.; Garcia, A.Surface deformation parameters and its use in volcano monitoring have evolved from classical geodetic procedures up to those based on Global Navigation Satellite Systems (GNSS), in particular the most widely used and known Global Positioning System (GPS), profiting from the automated data processing, positioning precision and rates, as well as the large storage capacity and low power consumption of its equipments. These features have enabled the permanent GNSSGPS data acquisition to ensure the continuous monitoring of geodetic benchmarks for the evaluation of surface deformation in active tectonic or volcanic areas. In Deception Island (Antarctica), a normal vector analysis is being used to give surface deformation based on three permanently observed GNSSGPS benchmarks. Due to data availability, both in the past and for near real-time use, all benchmarks used are inside the monitored volcanic area, although the reference is away from thermal springs and/or fumaroles, unlike the other two. The time variation of slope distances to the reference benchmark and of the magnitude and inclination of the normal vector to the triangle defined by the reference benchmark and any other two, provides the spatial deformation in the volcanic area covered. The normal vector variation in magnitude gives information on compression or expansion, here called spatial dilatometer, while the changes in inclination gives information on relative uplift or subsidence, here called spatial inclinometer. In geodesy, the triangle is a basic geometric unit and the areal strain is commonly applied in tectonics and volcanism. The normal vector analysis conjugates both, benefiting from the method's precision, simplicity and possibility to model the surface using several triangles. The proposed method was applied to GNSSGPS data collected every austral summer between 20012002 and 20092010 in Deception Island. The results evidence that Deception Island acts as a strain marker in the Bransfield Basin volcano-tectonic setting.
- Inter-annual variations of macrobenthic communities over three decades in a land-locked coastal lagoon (Santo André, SW Portugal)Publication . Correia, M. J.; Costa, J. L.; Chainho, P.; Félix, P. M.; Chaves, M. L.; Medeiros, J. P.; Silva, G.; Azeda, C.; Tavares, P.; Costa, A.; Costa, A. M.; Bernardo, J.; Cabral, H. N.; Costa, M. J.; Cancela, M. LeonorSanto Andre is an enclosed brackish water coastal lagoon with temporary connections to the sea by a man-made channel. The exchange and mixture of saltwater and freshwater is irregular and the lagoon may show daily and seasonal fluctuations, but also long-term variation. Different benthic communities may be present along the annual cycle according to the magnitude of episodic freshwater and sea water inputs. In the last 30 years the communication with the sea has followed different regimes from year to year and, as a consequence, macrobenthic communities, assessed several times during the period before the opening to the sea, shifted from freshwater to marine affinities. Major differences were found between 1979 and 2010, with a preponderance of species with marine affinity, and the 1980s in which the organisms with freshwater affinity prevailed. Benthic communities are frequently used to assess aquatic environmental condition. Metrics used in the indices currently under discussion to assess ecological status of aquatic ecosystems within the scope of European Water Framework Directive were applied to Santo Andre data and the applicability of these metrics to assess quality in this coastal land-locked lagoon was discussed. (C) 2012 Elsevier Ltd. All rights reserved.
- Blavigator: a navigation aid for blind personsPublication . José, João; Moreno, M.; Pinilla-Dutoit, J.; Rodrigues, J. M. F.; du Buf, J. M. H.Blavigator (blind navigator) is a vision aid for blind and visuaIIy impaired persons. It supports local navigation by detecting waIkable paths in the immediate vicinity of the user. It guides the user for centering on the path.
- Alimentação saudável e adaptada para idososPublication . Braz, NídiaNas aulas de Alimentação Saudável e adaptada apresentam-se os conceitos gerais sobre Alimentação saudável – composição das matérias-primas alimentares e importância das preparações culinárias. Estilos de vida, hábitos alimentares e sua influência na saúde do idoso. Adequação da alimentação aos condicionalismos mais frequentes no idoso. Alimentação coletiva e individual de idosos solitários, em contexto familiar ou institucionalizados.
- Polyunsaturated fatty acids of marine macroalgae: potential for nutritional and pharmaceutical applicationsPublication . Pereira, Hugo; Barreira, Luisa; Figueiredo, Filipe; Custodio, Luisa; Vizetto-Duarte, Catarina; Polo, Cristina; Resek, Eva; Engelen, Aschwin; Varela, JoaoAs mammals are unable to synthesize essential polyunsaturated fatty acids (PUFA), these compounds need to be taken in through diet. Nowadays, obtaining essential PUFA in diet is becoming increasingly difficult; therefore this work investigated the suitability of using macroalgae as novel dietary sources of PUFA. Hence, 17 macroalgal species from three different phyla (Chlorophyta, Phaeophyta and Rhodophyta) were analyzed and their fatty acid methyl esters (FAME) profile was assessed. Each phylum presented a characteristic fatty acid signature as evidenced by clustering of PUFA profiles of algae belonging to the same phylum in a Principal Components Analysis. The major PUFA detected in all phyla were C-18 and C-20, namely linoleic, arachidonic and eicosapentaenoic acids. The obtained data showed that rhodophytes and phaeophytes have higher concentrations of PUFA, particularly from the n-3 series, thereby being a better source of these compounds. Moreover, rhodophytes and phaeophytes presented. healthier. Sigma(n-6/)Sigma(n-3) and PUFA/saturated fatty acid ratios than chlorophytes. Ulva was an exception within the Chlorophyta, as it presented high concentrations of n-3 PUFA, alpha-linolenic acid in particular. In conclusion, macroalgae can be considered as a potential source for large-scale production of essential PUFA with wide applications in the nutraceutical and pharmacological industries.
- In two waters: contemporary evolution of lagoonal and marine white seabream (Diplodus sargus) populationsPublication . Gonzalez-Wangueemert, Mercedes; Perez-Ruzafa, AngelBrackish water ecosystems are often exposed to wide variations in environmental variables, including temperature and salinity, which may cause strong selective pressures on organisms modifying the genetic patterns of species. The aim of this work was to test whether there is a ‘divergence-with-gene flow’ in coastal lagoon populations of white seabream (Diplodus sargus) (Ria Formosa, S Portugal and Mar Menor, SE Spain) respect to four marine populations, by using partial sequences of cyt b mitochondrial gene and information from nine microsatellite loci. Genetic diversity was highest in both coastal lagoons (Mar Menor and Ria Formosa) considering mitochondrial and nuclear markers. Although some of FST population pairwise comparisons were not significant, analyses of molecular variance (AMOVAs) detected differences between groups (coastal lagoon and marine) close to significance. Also, only two haplotypes (Cytb-17 and Cytb-18) were detected in both coastal lagoon sampling sites and these localities (Mar Menor and Ria Formosa) showed the highest number of singletons, some of them with a high number of mutations, as has been already described for other Mar Menor populations (Pomatochistus marmoratus and Holothuria polii). Also, several tests detected significant positive and balancing selection considering mtDNA and microsatellite data. These data support the hypothesis of selection as one of the drivers of the genetic differences found between coastal lagoon and marine populations. The life strategy adopted by Diplodus sargus in coastal lagoons allows it to decrease its mortality rate and improve the heritability of its genes. Also, the increase time spent in coastal lagoons with different temperatures and salinities favours the fitness selection and the maintenance of exclusive haplotypes and genotypes in coastal lagoon inhabitants favouring the ‘divergence-with-gene-flow’.
- Reproductive biology of cuckoo ray Leucoraja naevusPublication . Maia, C.; Erzini, Karim; Serra-Pereira, B.; Figueiredo, I.The present study is the first to provide data on the reproductive biology of cuckoo ray Leucoraja naevus in Portuguese continental waters. No difference in size at maturity was detected between sexes, which was estimated as 56 cm total length. Spawning occurs all year round, but maximum activity was during winter months. Maximum fecundity is c. 63 eggs female-1 year-1. Encapsulated eggs are released in batches, nine in total with a mean number of seven extruded eggs in each batch.
- A disparity energy model improved by line, edge and keypoint correspondencesPublication . Martins, J. C.; Farrajota, Miguel; Lam, Roberto; Rodrigues, J. M. F.; Terzic, Kasim; du Buf, J. M. H.Disparity energy models (DEMs) estimate local depth information on the basis ofVl complex cells. Our recent DEM (Martins et al, 2011 ISSPlT261-266) employs a population code. Once the population's cells have been trained with randorn-dot stereograms, it is applied at all retinotopic positions in the visual field. Despite producing good results in textured regions, the model needs to be made more precise, especially at depth transitions.
- «
- 1 (current)
- 2
- 3
- »