Browsing by Issue Date, starting with "2014-04"
Now showing 1 - 10 of 19
Results Per Page
Sort Options
- Maritime halophyte species from southern Portugal as sources of bioactive moleculesPublication . Rodrigues, Maria Joao; Gangadhar, Katkam N.; Vizetto-Duarte, C; Wubshet, Sileshi G.; Nyberg, Nils T.; Barreira, Luísa; J. C. or Varela J. or Varela J.C.S., Varela; Custodio, LuisaExtracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC50 = 0.1 mg/mL) and J. acutus (IC50 = 0.4 mg/mL), and the ether extracts of J. acutus (IC50 = 0.2 mg/mL) and A. macrostachyum (IC50 = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC50 = 0.4 mg/mL) and H. portulacoides (IC50 = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC50 = 109 mu g/mL) and the hexane extract of P. coronopus (IC50 = 98.0 mu g/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells.
- Detailed investigation of overwash on a gravel barrierPublication . Matias, Ana; Blenkinsopp, Chris E.; Masselink, GerdThis paper uses results obtained from a prototype-scale experiment (Barrier Dynamics Experiment; BARDEX) undertaken in the Delta flume, the Netherlands, to investigate overwash hydraulics and morphodynamics of a prototype gravel barrier. Gravel barrier behaviour depends upon a number of factors, including sediment properties (porosity, permeability, grain-size) and wave climate. Since overwash processes are known to control short-term gravel barrier dynamics and long-term barrier migration, a detailed quantification of overwash flow properties and induced bed-changes is crucial. Overwash hydrodynamics of the prototype gravel barrier focused on the flow velocity, depth and discharge over the barrier crest, and the overwash flow progression across and the infiltration through the barrier. During the BARDEX experiment, overwash peak depth (0.77 m), velocity (5 m s−1 ) and discharge (max. 6 m3 m−1 ) were high, especially considering the relatively modest wave energy (significant wave height = 0.8 m). Conversely to schemes found in the literature, average flow depth did not linearly decrease across the barrier; rather, it was characterised by a sudden decrease at the crest, a milder decrease at the barrier top and then propagation as a shallow water lens over the backbarrier. The barrier morphological evolution was analysed over a series of 15-min experimental runs and at the timescale of individual overwash events. Overall, the morphological variation did not result from an accumulation of many small consistently erosive or accretionary events, but rather the mean bed elevation change per event was quite large (10 mm) and the overall morphology change occurred due to a small imbalance in the number of erosive and accretionary events at each location. Two relationships between overwash hydrodynamic variables were deduced from results: (1) between overwash flow depth and velocity a power-type relation was obtained; and (2) a linear relation was observed between overwash flow depth and maximum overwash intrusion distance across the barrier top (i.e. overwash intrusion). Findings from this study are useful to enhance the knowledge of overwash processes and also have practical applications. On the one hand, results shown here can be use for the validation of overwash predictive models, and additionally, the simple empirical relations deduced from the dataset can be used by coastal managers to estimate overwash intrusion distance, which in turn can assist in the location of areas under risk of overwash and breaching.
- Global geriatric evaluation of the Algarve populationPublication . Braz, Nídia; Pais, Sandra; Cordeiro, Clara; Oliveira, Giovanna; Conde, MonserratThe ageing of population challenges communities to adapt and evolve to accommodate the needs of people that live longer (mostly out of work, either healthy, fragile or with chronic disease). Population ageing in the Algarve is higher than in overall Portugal. Studies on health conditions, frailty risk factors and elderly specific needs are undeveloped in Portugal and unknown in the Algarve. Objective To prepare a tool for Global Geriatric Evaluation, to be used in the “Survey of Health and Ageing in the Region of Algarve - SHARA”, a commitment to “European Innovation Partnership on Active and Healthy Ageing”. Methods A preliminary version of the screening tool, which includes well-known instruments to measure health condition (EASY-care), risk of fall (Tinetty), physical activity (Baecke’s modified questionnaire), nutritional condition (MNA), cognitive and depressive status (MMSE, Yesavage geriatric depression scale), together with socio-demographic characteristics, was applied to an independent sample of subjects from an elderly community centre - ARPI (“Associação de Reformados, Pensionistas e Idosos do Concelho de Faro”), with ages between 55 and 89. Results ARPI is mostly frequented by women, who either have risk of malnutrition or malnutrition incidence, a relevant risk of fall or are physically active. Those who live alone, show a higher risk of fall. Conclusions ARPI members are active, but with risk of malnutrition and fall, suggesting the relevance and importance of future interventions in these areas. The proposed screening tool showed to be adequate for the SHARA study, suitable to provide wider information on frailty.
- Morrey spaces are closely embedded between vanishing stummel spacesPublication . Samko, StefanWe prove a new property of Morrey function spaces by showing that the generalized local Morrey spaces are embedded between weighted Lebesgue spaces with weights differing only by a logarithmic factor. This leads to the statement that the generalized global Morrey spaces are embedded between two generalized Stummel classes whose characteristics similarly differ by a logarithmic factor. We give examples proving that these embeddings are strict. For the generalized Stummel spaces we also give an equivalent norm.
- “Animação sociocultural e valorização do património turístico-cultural do Algarve. O caso da Fortaleza de Sagres”Publication . Henriques, Cláudia; Pereira, José Dantas Lima; Lopes, Marcelino de Sousa; Maltez, Maria AlexandraO turismo cultural tem vindo a ganhar um significado crescente. Em destinos de sol e mar como o Algarve tem havido o reconhecimento crescente da importancia em desenvolver e apostar no património histórico e cultural identitário da região. A Fortaleza de Sagres como icone patrimonial assume neste contexto um papel determinante.
- Standard metabolism and growth dynamics of laboratory-reared larvae of Sardina pilchardusPublication . Moyano, M.; Garrido, Susana; Teodosio, Maria; Peck, M. A.This study provides the first measurements of the standard respiration rate (RS) and growth dynamics of European sardine Sardina pilchardus larvae reared in the laboratory. At 15° C, the relationship between RS (µl O2 individual−1 h−1) and larval dry mass (MD, µg) was equal to: RS = 0·0057(±0·0007, ± s.e.)·MD0·8835(±0·0268), (8–11% MD day−1). Interindividual differences in RS were not related to interindividual differences in growth rate or somatic (Fulton's condition factor) or biochemical-based condition (RNA:DNA).
- Requirement for highly efficient pre-mRNA splicing during Drosophila early embryonic developmentPublication . Guilgur, Leonardo Gastón; Prudencio, Pedro; Sobral, Daniel; Liszekova, Denisa; Rosa, Andre; Martinho, Rui GoncaloDrosophila syncytial nuclear divisions limit transcription unit size of early zygotic genes. As mitosis inhibits not only transcription, but also pre-mRNA splicing, we reasoned that constraints on splicing were likely to exist in the early embryo, being splicing avoidance a possible explanation why most early zygotic genes are intronless. We isolated two mutant alleles for a subunit of the NTC/Prp19 complexes, which specifically impaired pre-mRNA splicing of early zygotic but not maternally encoded transcripts. We hypothesized that the requirements for pre-mRNA splicing efficiency were likely to vary during development. Ectopic maternal expression of an early zygotic pre-mRNA was sufficient to suppress its splicing defects in the mutant background. Furthermore, a small early zygotic transcript with multiple introns was poorly spliced in wild-type embryos. Our findings demonstrate for the first time the existence of a developmental pre-requisite for highly efficient splicing during Drosophila early embryonic development and suggest in highly proliferative tissues a need for coordination between cell cycle and gene architecture to ensure correct gene expression and avoid abnormally processed transcripts.
- Trends in landings of fish species potentially affected by climate change in Portuguese fisheriesPublication . Teixeira, Célia M.; Gamito, Rita; Leitão, Francisco; Erzini, Karim; Costa, Maria J.; Cabral, Henrique N.Fisheries are an important source of food, with a high economic value and social significance. The present worrying situation of the world fisheries is the result of the interaction between different factors (e.g. climatic variations, natural oscillations, technological innovation), but the greatest challenges are overfishing and climate change. The species richness of the Portuguese coast is generally higher than that found in northern Europe and similar to that of the Mediterranean, since many species have their southern or northern distribution limits along the Portuguese coast. The zoogeographic importance of this latitudinal area has long been recognized, representing the transition between north-eastern Atlantic warm-temperate and cold-temperate regions, which makes the Portuguese coast an area of great sensitivity to the detection of climate change. Official landing data for commercial species that have the Portuguese coast as their distribution limit were analysed together with sea surface temperature for the period of 1927-2011. In general, landings of species with affinity for temperate waters presented a decreasing trend, whereas species with affinity for subtropical/tropical waters showed an increasing trend. These variations were associated with variation in temperature: lower landings of temperate species occurred mainly in warm years, whereas landings of subtropical/tropical species presented an opposite trend, with higher landings in warm years. Preparing for the impacts of climate change is crucial for the sustainability of fisheries. Management should take into consideration information about environmental factors that affect species distribution and abundance.
- Antioxidant and anti-cholinesterase activities of Lavandula viridis L’Hér extracts after in vitro gastrointestinal digestionPublication . Costa, Patrícia; Grevenstuk, Tomás; Costa, Ana M. Rosa da; Gonçalves, Sandra; Romano, AnabelaLavandula viridis L’Hér is an aromatic shrub with relevant biological activities associated to the presence ofphenolic compounds. However, these compounds must be bioavailable to exert their biological function.Therefore, in this study, we investigated the influence of the L. viridis extract matrices on the digestion ofthe main component rosmarinic acid and their antioxidant and anti-cholinesterase activities after in vitrogastrointestinal digestion. Overall, the antioxidant and anti-cholinesterase activities were assured afterin vitro gastrointestinal processes and we observed that the L. viridis extract matrices have an importantrole in the bioactive effects of their main compound, rosmarinic acid. The L. viridis extracts and rosmarinicacid did not show any toxic effect on colon adenocarcinoma Caco-2 cell viability. Finally, the compoundsfrom L. viridis extracts were not metabolized by Caco-2 cells and were not able to permeate into them.
- Comparing the performance of the SF-6D and the EQ-5D in different patient groupsPublication . Ferreira, Lara N.; Ferreira, Pedro L.; Pereira, Luis N.Introduction: This research aims to explore the performance of the SF-6D and the EQ-5D in patients suffering from asthma, chronic obstructive pulmonary disease, cataracts, and rheumatoid arthritis. In particular, the aim of this research is twofold: 1) to study the level of agreement between the indexes and the descriptive systems of the dimensions of the SF-6D and the EQ-5D, and 2) to analyze the discriminative ability of the instruments. Material and Methods: A sample of 643 patients completed both the SF-36v2 and the EQ-5D. The discriminative ability of the instruments was analyzed. Furthermore, the level of agreement between the indexes and the descriptive systems of the dimensions of the SF-6D and the EQ-5D were studied. The level of agreement between instruments was investigated using correlation coefficients and the Bland-Altman plots, while the influence of medical condition and other socio-demographic variables was analyzed using non-parametric tests. Paired-samples tests were used to identify differences between the scores. Results and Discussion: The results show a strong correlation and agreement between both indexes. Overall, questionnaire indexes differ by medical condition and socio-demographic groups and both instruments are able to discriminate between socio-demographic groups. Conclusion: This study confirmed the hypothesis that the SF-6D generates higher utility values in less healthy individuals. The SF-6D and the EQ-5D seem to perform differently in each of the diseases studied since the descriptive statistics differ between instruments and the level of correlation is not uniform. Results show that the instruments generate different utility values, but there is a strong agreement between both indexes. Thus, the two instruments are not interchangeable and their results cannot be directly comparable.