228 research outputs found

    Fault activity studies in the Lower Tagus valley and Lisbon region using geophysical data

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    he Metropolitan Area of Lisbon and the Lower Tagus Valley (LTV) region are located in central Portugal and inhabited by nearly 4 million people. The region has suffered throughout its history the effect of destructive earthquakes caused by hidden faults, possibly related to the plate boundary, which is sited approximately 400 km south of the region (Figure 1). In spite of low slip-rates and big recurrence times that have been estimated for these local, regional faults, they can produce moderate-to-large earthquakes that cause large damage and loss of life, as in 1344, 1531, or 1909 (e.g. Justo and Salwa, 1998; Cabral et al., 2003; 2013). The shorter occurrence time of the earthquakes might be owing to the existence of multiple active faults and/or time clustering owing to stress drop caused by proximal faults (e.g. Carvalho et al., 2006). Therefore, the seismic hazard and risk evaluation of the region has long been a reason of concern. Geological outcrop and geomorphologic mapping identified several regional faults in the LTV region that could be the source the historical earthquakes, but some of them do not affect. Quaternary sediments and lacked the proofs that they were active faults. On the other side, in the vast quaternary alluvial plains that cover the region, it was difficult to identify active faults, as the sedimentation/erosion rates erase any possible surface rupture caused by the low slip-rate faults (<0,35 mm/y). By the late-20th century, seismic reflection data that had been acquired for the oil-industry till the beginning of the 1980s began to be used to identify the major hidden fault zones (e.g. Cabral et al., 2003; Vilanova and Fonseca, 2004; Carvalho et al., 2006). Potential field data was also used to locate active faults in the areas where no seismic data is available (Carvalho et al., 2008; 2011). Though a few more active faults have been proposed, the vast majority of authors agree that the following active faults threaten the region: Nazaré-Caldas da Rainha, Lower Tagus Valley, Ota, Azambuja, Vila Franca de Xira (VFX), Pinhal Novo and Porto Alto faults (Garcia-Mayordomo et al., 2012; Vilanova et al., 2014). In this work, we discuss the acquisition, processing and interpretation of near surface geophysical works carried out over three of these faults — the VFX, Porto Alto and Azambuja faults — in order to confirm they have had activity during the Holoceneera. Their location is shown in Figure 2. We further estimate some of its fault parameters (vertical displacement, slip-rate, length, etc.) and respective implications in terms of seismic hazard

    A perceção do consumidor de fast moving consumer goods: Quanto ao Continente Food Lab

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    O mercado do retalho alimentar é bastante competitivo. Todos os players correm contra o tempo para poder obter vantagem competitiva sobre os demais. É neste clima competitivo que o Continente lança uma marca de produtos alimentares inovadores, o Continente Food Lab. Esta nova marca entra no mercado como uma aposta do Continente e da SONAE MC na inovação alimentar, no entanto, encontrou nesse mesmo mercado alguns desafios, sendo o principal desses mesmos desafios a sua identidade e a forma como esta é percecionada pelos consumidores. Se o Continente Food Lab se vê a si próprio como uma marca de produtos inovadores do retalho alimentar, os consumidores tendem a percecionar o Continente Food Lab como uma marca de produtos saudáveis e biológicos, o que pode trazer alguns problemas, com espectativas desfraldadas por parte dos consumidores que esperavam, de forma errada, estar a comprar produtos saudáveis ou biológicos e, uma consequente quebra de confiança por parte do consumidor para com a marca. O propósito deste estudo de caso é o de compreender de que forma a marca Continente Food Lab pode contornar este problema de miopia de marca que carrega. De uma forma mais específica, este estudo de caso pretende definir os atributos do triângulo da marca que levam o consumidor de Fast-Moving Consumer Goods a percecionar o Continente Food Lab como uma marca do retalho alimentar inovadora. Para isso, deu-se início a um estudo de caso que analisa vários atributos do triângulo da marca, aos olhos dos consumidores de produtos alimentares inovadores. Desta forma, compreendeu-se quais as melhores práticas para a criação de uma marca de produtos inovadores no retalho alimentar. Com os resultados desta investigação, contribuiu-se para uma melhor compreensão de como as marcas de produtos alimentares inovadores se devem construir. Além disso, contribuiu-se com uma proposta de como o Continente Food Lab se pode posicionar, de forma a ser percecionado como uma marca de produtos inovadores e não como uma marca de produtos biológicos e saudáveis

    Excess Thermodynamics of Mixtures Involving Xenon and Light Linear Alkanes by Computer Simulation

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    Excess molar enthalpies and excess molar volumes as a function of composition for liquid mixtures of xenon + ethane (at 161.40 K), xenon + propane (at 161.40 K) and xenon + n-butane (at 182.34 K) have been obtained by Monte Carlo computer simulations and compared with available experimental data. Simulation conditions were chosen to closely match those of the corresponding experimental results. The TraPPE-UA force field was selected among other force fields to model all the alkanes studied, whereas the one-center Lennard−Jones potential from Bohn et al. was used for xenon. The calculated and for all systems are negative, increasing in magnitude as the alkane chain length increases. The results for these systems were compared with experimental data and with other theoretical calculations using the SAFT approach. An excellent agreement between simulation and experimental results was found for xenon + ethane system, whereas for the remaining two systems, some deviations that become progressively more significant as the alkane chain length increases were observed

    Aspect composition for multiple target languages using LARA

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    Usually, Aspect-Oriented Programming (AOP) languages are an extension of a specific target programming language (e.g., Aspect J for JAVA and Aspect C++ for C++). Although providing AOP support with target language extensions may ease the adoption of an approach, it may impose constraints related with constructs and semantics. Furthermore, by tightly coupling the AOP language to the target language the reuse potential of many aspects, especially the ones regarding non-functional requirements, is lost. LARA is a domain-specific language inspired by AOP concepts, having the specification of source-to-source transformations as one of its main goals. LARA has been designed to be, as much as possible, independent of the target language and to provide constructs and semantics that ease the definition of concerns, especially related to non-functional requirements. In this paper, we propose techniques to overcome some of the challenges presented by a multilanguage approach to AOP of cross-cutting concerns focused on non-functional requirements and applied through the use of a weaving process. The techniques mainly focus on providing well-defined library interfaces that can have concrete implementations for each supported target language. The developer uses an agnostic interface and the weaver provides a specific implementation for the target language. We evaluate our approach using 8 concerns with varying levels of language agnosticism that support 4 target languages (C, C++, JAVA and MATLAB) and show that the proposed techniques contribute to more concise LARA aspects, high reuse of aspects, and to significant effort reductions when developing weavers for new imperative, object-oriented programming languages

    Downregulation of miR-130b~301b cluster is mediated by aberrant promoter methylation and impairs cellular senescence in prostate cancer

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    Background: numerous DNA-damaging cellular stresses, including oncogene activation and DNA-damage response (DDR), may lead to cellular senescence. Previous observations linked microRNA deregulation with altered senescent patterns, prompting us to investigate whether epigenetic repression of microRNAs expression might disrupt senescence in prostate cancer (PCa) cells. Methods: differential methylation mapping in prostate tissues was carried using Infinium HumanMethylation450 BeadChip. After validation of methylation and expression analyses in a larger series of prostate tissues, the functional role of the cluster miR-130b~301b was explored using in vitro studies testing cell viability, apoptosis, invasion and DNA damage in prostate cancer cell lines. Western blot and RT-qPCR were performed to support those observations. Results: we found that the miR-130b~301b cluster directs epigenetic activation of cell cycle inhibitors required for DDR activation, thus stimulating the senescence-associated secretory phenotype (SASP). Furthermore, overexpression of miR-130b~301b cluster markedly reduced the malignant phenotype of PCa cells. Conclusions: altogether, these data demonstrate that miR-130b~301b cluster overexpression might effectively induce PCa cell growth arrest through epigenetic regulation of proliferation-blocking genes and activation of cellular senescence

    A Common Mechanism for Influenza Virus Fusion Activity and Inactivation

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    The fusion of influenza virus (A/PR/8/34 strain) with PC-12 cells was monitored by a fluorescence assay, and the results were analyzed with a mass-action model which could explain and predict the kinetics of fusion. The model accounted explicitly for the reduction in the fusion rate constant upon exposure of the virus to low pH, either for the virus alone in suspension or for the virus bound to the cells. When the pH was lowered without previous viral attachment to cells, an optimal fusion activity was detected at pH 5.2. When the virus was prebound to the cells, however, reduction of pH below 5.2 resulted in enhanced fusion activity at the initial stages. These results were explained by the fact that the rate constants of both fusion and inactivation increased severalfold at pH 4.5 or 4, compared to those at pH 5.2. At pH 5.2, lowering the temperature from 37 to 20 or 4 °C resulted in a decrease in the fusion rate constant by more than 30- or 1000-fold, respectively. Inactivation of the virus when preincubated in the absence of target membranes at pH 5 was found to be rapid and extensive at 37 °C, but was also detected at 0 °C. Our results indicate a strong correlation between fusion and inactivation rate constants, suggesting that the rate-limiting step in viral hemagglutinin (HA)-mediated fusion, that is, rearrangement of viral glycoproteins at the contact points with the target membrane, is similar to that involved in fusion inactivation. © 1993, American Chemical Society. All rights reserved

    PT-CRIS: Um miradouro sobre o universo científico nacional

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    Reconhecida a importância da ciência, tecnologia, inovação e do conhecimento gerado pela investigação científica, são inúmeros os sistemas de informação criados para dar resposta a necessidades de gestão e disseminação de informação em diferentes domínios. Contudo, a dispersão de informação em vários sistemas, a não adoção de normas/práticas de referência e consequentemente a replicação de informação criam dificuldades às várias entidades que gerem ou consultam informação sobre ciência e respetivos indicadores na capacidade de gestão, execução, avaliação e tomada de decisão relativa a processos de investigação. Surge assim a necessidade de criar um sistema que ofereça uma visão global do universo de ciência e tecnologia, agregando e relacionando informação de suporte à atividade científica desenvolvida em Portugal, i.e., informação sobre investigadores, organizações, programas de financiamento, projetos, resultados de investigação, instalações, equipamentos e serviços. O sistema, ao relacionar e contextualizar a informação científica atualmente dispersa em vários sistemas, permitirá transformar informação em conhecimento, aumentar a visibilidade e difusão da ciência e simplificar processos na gestão da produção científica nacional.Comunicação patrocinada pela KEEP SOLUTION

    Diffusion coefficients of chlorophenols in water by computer simulation

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    Cholophenols have found extensive industrial applications as wood preservatives or intermediated compounds for pesticide synthesis, and are also by-products of wood pulp bleaching processes [1]. As a result, they are nowadays common natural water contaminants, being considered priority substances by recent European Directives for Environmental Protection, due to their toxicity and persistence. The establishment of theoretical models to study environmental fate of chlorophenols is an important scientific topic. On the other hand, some unit operations are used to remove them from wastewater, such as adsorption [2] and reverse osmosis [3]. In both approaches, the knowledge of some key properties is needed, such as diffusion coefficients in water. Despite of their obvious importance, the diffusion coefficients of chlorophenols in water are scarce in literature and in many cases have to be estimated. Computer simulation can provide a way to systematically estimate this parameter for chlorophenol chemical family

    Levantamentos geofísicos no setor português da Faixa Piritosa Ibérica: perspetiva global da sua importância em prospeção de sulfuretos maciços e interpretação geológica

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    ABSTRACT: The application of geophysical techniques to massive sulphide deposits exploration has proven to be a success in the Iberian Pyrite Belt (IPB) metallogenetic province, both in Portugal and in Spain. Several hidden deposits were discovered through the interpretation of geological models, supported by geophysical data collected in land and airborne surveys, as well as applied using down hole techniques in selected drill holes. This paper presents an overview of the methodologies applied in Portugal in the South Portuguese Zone (SPZ) geological domain, where the IPB is included, mostly by the LNEG and mining companies, with emphasis on the interpretation of the regional gravity, magnetometry and radiometry surveys, published in 1/400 000 scale by the EXPLORA/Alentejo2020 Project. In this regional mapping program, the large volume of data collected by LNEG and mining companies since the 1960’s was compiled and processed. The integrated interpretation and correlation between these methods will enable a better planning of new IPB exploration investments. IPB Volcano-Sedimentary Complex (VSC, Famennian to Late Visean age) lineaments are well defined in the gravity and magnetic fields along the IPB western region (e.g. Alcoutim/Neves Corvo/Montinho/Sesmarias/Lousal/Caveira). Aeromagnetic data also reflect deep and large anomalies related with the SPZ basement. A rock density database is presented and used to interpret the gravity data. Radiometric map (Natural Radioactivity), based mostly in airborne radiometric surveys, show contrasts between rocks in Paleozoic, Mesozoic and Cenozoic formations and correlations with geological and hydrothermal mapping are highlighted. The use of geophysical techniques is particularly critical in areas where VSC is concealed by younger sediments (e.g. Baixo Alentejo Flysch Group and/or Cenozoic formations), allowing the selection of target areas. Case studies are discussed based on electromagnetic, seismic and magnetotelluric methods and on the high mineral potential of defined targets. Multilayered data correlation (geophysics including petrophysical data, geochemistry and stratigraphic high-resolution models) is a key prospecting methodology and is essential for the accurate modelling of ore horizons and geological structures. Considering the IPB potential for VMS deposits, including the possible discovery of new giant (> 200 Mt) deposits, an increase of investment in new geophysical methods can be predicted. LNEG development of R&D projects such as EXPLORA/Alentejo2020 and SmartExplorationTM/H2020 also contribute to a favourable setting in the province, both in near mining and green fields scenarios. Thus, new discoveries are expected, like others made in the recent times in the IPB Portuguese sector, such as Lagoa Salgada (SFM, 1992, SFM; Redcorp/EDM, 2011; Redcorp/Ascendant/EDM, 2017), Semblana (Somincor-AGC-Lundin Mining, 2010), Monte Branco (Somincor Lundin Mining, 2012) and Sesmarias (Maepa/Avrupa, 2014). The importance of these data goes beyond the mineral exploration purpose. Since some of them use rock and mineral physical properties that can be related with environmental contamination (e.g. radiometry and magnetics) they can also be used in geochemical background studies, acid mine drainage and metal dispersion. Therefore, they can also promote a deeper knowledge in other areas of research related with environment preservation.RESUMO: A aplicação de técnicas de prospeção geofísica na pesquisa de jazigos de sulfuretos maciços na Faixa Piritosa Ibérica (FPI) tem-se revelado um sucesso em Portugal e em Espanha. Vários jazigos ocultos foram descobertos a partir da interpretação de modelos geológicos, com o apoio de dados geofísicos recolhidos em levantamentos terrestres, aerotransportados ou em profundidade, em sondagens (diagrafias). Neste artigo, apresenta-se uma análise das metodologias aplicadas principalmente pelo LNEG e empresas mineiras em Portugal, na Zona Sul Portuguesa (ZSP), onde se insere a FPI. Destaca-se a interpretação dos levantamentos regionais, esc. 1/400 000, de gravimetria, magnetometria e radiometria (EXPLORA/Alentejo2020). Nestes programas, foi feito o processamento de um volume de informação significativo, a partir de dados obtidos desde a década de 1960. Neste contexto indicam-se diversos alinhamentos de gravimetria e de aeromagnetometria relativos a unidades geológicas com elevado potencial mineiro, como o Complexo Vulcano-Sedimentar (CVS, idade Famenniano a Viseano sup.), sobressaindo o eixo Alcoutim/Neves Corvo/Montinho/Sesmarias/Lousal/Caveira. Os dados de aeromagnetismo refletem também anomalias com origens mais profundas e relacionadas com a estrutura basal da ZSP. A base de dados de densidades de rocha é utilizada na interpretação gravimétrica da FPI. O mapa radiométrico (Radioatividade Natural), baseado fundamentalmente em radiometria aeroportada (contagens totais) mostra o contraste à superfície de litologias das formações paleozoicas, mesozoicas e cenozoicas, sendo salientado, no primeiro caso, a sua correlação com a cartografia de alterações hidrotermais. Em áreas onde o CVS se encontra subjacente sob sedimentos mais recentes (ex. Grupo Flysch Baixo Alentejo e formações cenozoicas), o uso de técnicas geofísicas é fundamental para a seleção de alvos. São também descritos exemplos sobre a aplicação de métodos eletromagnéticos, sísmicos e magnetotelúricos na identificação e caracterização de estruturas geológicas. A análise integrada de diferentes métodos geofísicos, complementados com informação geológica e geoquímica, constitui a melhor metodologia de prospeção, sendo essencial para a pesquisa de horizontes de mineralização. Considerando a FPI como uma das principais províncias metalogenéticas do mundo, é expectável que venham a ocorrer mais investimentos e assim serem identificados novos jazigos, inclusive com dimensão superior a 200 Mt. Através de projetos ID como o EXPLORA/Alentejo2020 e SmartExplorationTM/H2020 o LNEG contribui para um melhor conhecimento na FPI em cenários de prospeção near mining e green fields. Nesta perspetiva, são esperadas novas descobertas de jazigos à semelhança do que tem acontecido em Portugal, como por exemplo Lagoa Salgada (SFM-1992, Redcorp/EDM 2011, Redcorp/Ascendant/EDM-2017), Semblana (Somincor-AGC Lundin Mining, 2010), Monte Branco (Somincor-Lundin Mining, 2012) e Sesmarias (Maepa/Avrupa, 2014). A importância destes dados vai muito para além da prospeção mineira. Uma vez que alguns métodos utilizam propriedades físicas que podem ser relacionadas com contaminações ambientais. Certos métodos geofísicos como radiometria e magnetometria, resistividade e métodos elétricos em geral, podem ser utilizados também em trabalhos de investigação sobre background geoquímico, drenagem ácida de mina e dispersão de metais. Desta forma, a aplicação destes métodos promove também um conhecimento mais aprofundado noutras áreas de investigação relacionadas com a preservação do ambiente.info:eu-repo/semantics/publishedVersio
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