975 resultados para Pedro V, King of Portugal, 1837-1861


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The Japanese oyster drill or rock snail Pteropurpura (Ocinebrellus) inornata (Récluz, 1851), a marine mollusc, belonging to the family Muricidae, is reported from Portugal for the first time. This non-indigenous species, most likely introduced accidentally from French oyster rearing areas into mainland Portugal, has been regularly sampled in shellfish-culture and nearby environments in Sagres, Algarve, Southwest Portugal since 2005–2008. Detailed studies are urgently needed in order to assess whether or not it has become an invasive species due to a range expansion beyond its point of initial introduction. Outputs should provide information to decision-makers to predict and limit further spread which might result in biodiversity loss and negative economical consequences in locally species-rich areas.

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The marine gastropod Anachis aliceae (Pallary, 1900) is reported with certainty for the first time from the Algarve, south coast of Portugal from species-rich rocky priority biotope. Several live specimens of this species belonging to the Columbellidae family were collected and identified from by-catch samples, recovered from octopus traps set at depths between 50 and 70 m off Ponta da Piedade. Taxonomic validation of the newly recorded species is based on the comparison to other related species within the genus.

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IS/IT investments are seen has having an enormous potential impact on the competitive position of the firm, on its performance, and demand an active and motivated participation of several stakeholder groups. The shortfall of evidence concerning the productivity of IT became known as the ‘productivity paradox’. As Robert Solow, the Nobel laureate economist stated “we see computers everywhere except in the productivity statistics”. An important stream of research conducted all over the world has tried to understand these phenomena, called in the literature as «IS business value» field. However, there is a gap in the literature, addressing the Portuguese situation. No empirical work has been done to date in order to understand the impact of Information Technology adoption on the productivity of those firms. Using data from two surveys conducted by the Portuguese National Institute of Statistics (INE), Inquiry to the use of IT by Portuguese companies (IUTIC) and the Inquiry Harmonized to (Portuguese) companies (accounting data), this study relates (using regression analysis) the amounts spent on IT with the financial performance indicator Returns on Equity, as a proxy of firm productivity, of Portuguese companies with more than 250 employees. The aim of this paper is to shed light on the Portuguese situation concerning the impact of IS/IT on the productivity of Portuguese top companies. Empirically, we test the impact of IT expenditure on firm productivity of a sample of Portuguese large companies. Our results, based on firm-level data on Information Technology expenditure and firm productivity as measured by return on equity (1186 observations) for the years of 2003 and 2004, exhibit a negative impact of IT expenditure on firm productivity, in line with “productivity paradox” claimants.

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Greenhouse production is a very important activity in the West region of Portugal, with an area of approximately 800 ha where the regular production consists in two crops per year, one in winter-spring and the other in summer-autumn. Many growers are now prepared to better exploit market opportunities, since they know that the big export window opportunity is from June to September, when the production is difficult in other regions of south due to high temperatures. Grower’s use new and more productive varieties, either in soil or hydroponic systems, mostly in unheated greenhouses, naturally ventilated, and equipped with modern fertigation systems. Greenhouse production causes some environmental impacts due to the high use of inputs. Several improvements in technologies and crop practices may contribute to increase the use efficiency of resources, decreasing the negative environmental impacts. Greenhouse vegetable production in Northern EU countries is based on the supply of heating and differs significantly from the production system in the Southern EU countries. In the Northern countries, direct energy inputs, mostly for heating, are predominant while in the South the indirect energy input is also important, mainly associated with fertilizers, plastic cover materials and other auxiliary materials. The main objective of this work was to characterise the greenhouse production systems in the West region of Portugal, in order to evaluate the energetic consumptions (direct and indirect), the GHH emissions, the production costs and the farmer’s income. With this work the mostly important inputs were identified, allowing proposing alternative measures to improve efficiency and sustainability. All the data was obtained by surveys performed directly with growers, previously selected to be representative of the crop practices and greenhouse type of the region. However, more research should be performed in order to develop and to test technologies capable to improve resources use efficiency in greenhouse production.

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This article assesses how the last-visit features and the socio-demographic profile of tourists moderate repeat-visit patterns to Portugal, a mature destination where the persistence of loyal visitors has made its mark on tourism development. The methodology used is a survival analysis to assess the tourists’ repeat patterns. To test the model, a database of 4612 observations was employed, which was obtained from a survey of international tourists. Only repeat visitors with more than two visits over the years were considered for the purpose of the research. The study finds that a combination of socio-demographic characteristics, expectation/satisfaction, trip purpose, pull motivations and regional destination has a positive effect on repeat patterns, confirming that tourists’ willingness to repeat visits to Portugal is far from ceasing. Based on those tourists to Portugal who declared when they started to visit the country, and the number of years of their repeat visits, the article contributes to the literature by introducing new methods of assessing tourists’ repeat patterns for destinations.

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Abstract In the last years, several models have been presented trying to obtain lithosphere and Moho thickness in the Iberian Peninsula, using data related to geoid elevation and topography, gravity, seismicity and thermal analysis. The results obtained show a decrease in the thickness of the crust and the lithosphere in the SW part of the Iberian Peninsula. Density anomalies in the crust are also referred. Data obtained in the region was collected and deviations from average values used were detected. In this work, models were made taking into account the specific characteristics of the region. Heat flow, thermal conductivity, heat production, topography, gravity, seismic and geological data available for the region, were used to adjust the model. The results show that this region is different from other parts of the Iberian Peninsula and a special attention must be given to it. This work shows the importance of trying to know and understand the thermal structure of the region.

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ABSTRACT In the last years, several models were presented trying to obtain lithosphere and Moho thickness in the Iberian Peninsula, using data related to geoid elevation and topography, gravity, seismicity and thermal analysis. The results obtained show a decrease in the thickness of the crust and the lithosphere in the SW part of the Iberian Peninsula. Density anomalies in the crust are also referred. The work I intend to present is related with the south of the Ossa Morena Zone, the South Portuguese Zone and the Algarve, in the south of Portugal. Data obtained in the region was collected and deviations from average values used were detected. Models were made taking into account the specific characteristics of the region. Heat flow, thermal conductivity, heat production, topography, gravity, seismic and geological data available for the region, are used to adapt the models. A special attention will be given to the spatial variation of heat flow values and to Moho depth in the region. The results show that this region is different from other parts of the Iberian Peninsula and a special attention must be given to it. The different values obtained using seismic, gravity, and geoid height data, and the results obtained with models using thermal data shows the importance of trying to know and understand the thermal structure of the regions. Problems related with the use of average values will be focused.

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The present work describes the measurement effort for direct normal irradiance (DNI) evaluation in the sunny south of Portugal, with a network of eight radiation measurement stations in several locations (including Évora) providing a good coverage of the region. This new initiative for DNI measurement will still need many years (typically 10 or more) to produce a time series which can claim having long term statistical value. This problem can, however, be temporarily mitigated by measuring DNI at the same time as GHI and DHI, in a place where long term series dating back, already exist for those two. It so happens that a long term series (20 years) of global and diffuse solar irradiation exists for the location Évora. So the expectation is to establish correlations with the goal of attributing at least some long term statistical significance to the short and recent DNI series. The paper describes the setup of the measuring stations and presents the preliminary measurements obtained. It further presents the first correlations of monthly averages between normal beam (DNI), global and diffuse radiation. It then uses these correlations, admittedly without acceptable statistical significance (short series of less than one year of measured data), to exemplify how to get a prediction of long term DNI for Évora. This preliminary obtained value is compared to that predicted by the commercial data from Meteonorm.

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The non-indigenous bivalve Ruditapes philippinarum is native to the western Pacific Ocean and it has been one of the most widely introduced species for aquaculture purposes in Europe. In Portugal its presence is known in several estuaries for more than two decades and its populations have increased greatly along the last years1. Currently it’s one of the dominant benthic species in some areas of the Tagus estuary (264,1±470,8 ind./30s tow). Studies on the impacts of invasive bivalves on meiofaunal communities are scarce and restricted to the harvesting effect. Meiofauna of the Tagus estuary is poorly known and possible impacts of the introduction of R. philippinarum were never assessed.

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Changes in fish assemblage structure caused by human activities, such as fishing, can alter trophic relations in fish assemblages. In this context, Marine Protected Areas (MPA) are efficient tools for habitat recovery and ideal environments for evaluating changes on the trophic structure resulting from human activities. The present work targeted fish assemblages from two no-take MPAs from the northern half of South Alentejo and Costa Vicentina Marine Park, established in 2011. Previous works reported positive effects on local fish assemblages after no-take MPA designation, and it is therefore important to further study its impact on local fish assemblages, especially concerning trophic interactions. Local fish assemblages were sampled (summer 2011, winter 2012, summer 2013 and winter 2013) using trammel nets. Diets were characterized and digestive tract contents of the 10 most abundant fish species were compared between the no take MPAs (treatment) and adjacent areas (controls), and changes evaluated as a function of time since protection. Results revealed significant differences between the diets of fish from protected and non protected areas, with crabs being the preferential prey in both protected and control areas but being more ingested outside the no-take areas. However, these differences were evident since the beginning of the study. Fish assemblages from the northern area presented significantly larger niche breadth and significantly increasing with time. This way, the main effects of no-take MPA implementation were directly visible on the niche breadth but did not directly impact the diet composition of the sampled fish assemblages, contributing however to reinforce the already naturally existent differences. This work provides important information regarding the effect of changes in the fish assemblage caused by MPA designation on the trophic ecology of fish.

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Marine Protected Areas (MPAs) are increasingly being recommended as management tools for biodiversity conservation and fisheries. With the purpose of protecting the region's biodiversity and prevent the over exploitation of marine resources, in February 2011 the no-take MPAs of Ilha do Pessegueiro and Cabo Sard~ao were implemented within the “Parque Natural do Sudoeste Alentejano e Costa Vicentina “(PNSACV) Marine Park, south western coast of Portugal. As such, commercial and recreational fishing became prohibited in these areas. In order to evaluate the effects of these no-take MPAs, the structure of their fish assemblages and of adjacent control areas without fishing restrictions were studied between 2011 (immediately after implementation) and 2013 (two years after implementation). A total of 4 sampling campaigns were conducted (summer 2011, winter 2012, summer 2013 and winter 2013) using trammel nets and bottom trawl. Ichthyofaunal assemblages from the no-take MPAs (treatment) were compared with adjacent areas (controls) and changes evaluated as a function of time since protection. Results revealed significant increase in fish abundance after the implementation of the no-take MPAs. Furthermore, significant differences in the structure of fish assemblages (abundance and fish size) between protected and neighbouring areas were rapidly observed upon the implementation of the no-take MPAs. In addition, specimens of larger size occurred more frequently within Ilha do Pessegueiro no-take MPA in the last year of the study. Overall, despite the young age of these no-take MPAs, changes on the structure of their fish assemblages were already evident after only two years of protection, indicating that management measures such as MPA designation may play an important role to promote fisheries sustainable exploitation as well as to protect species with conservation interest.

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Estudo dos perfis e carreiras dos chancelares que serviram os reis portugueses ao longo do século XIV. Procura-se, com este estudo, reflectir sobre a evolução do papel dos eclesiásticos na construção da realeza e estabelecer tendências para a evolução dos perfis dos protagonistas do serviço régio.

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"Apendice documental": p. [185]-295.

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Vol. 1 contains a list of the members; v. 2 a list of the publications of the society.