338 research outputs found

    Impacts on water, soil and plants from the abandoned Miguel Vacas copper mine, Portugal

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    Soil, water and plant geochemistry was studied around the Miguel Vacas copper mine (Alentejo, SE Portugal), which stopped its exploitation and processing activities in 1991. After closure waste-rock piles remained exposed to weathering. The copper ore was mainly composed of copper phosphates and carbonates. Remediation actions were insufficient to prevent the spreading of waste-rock materials to surrounding farmed fields. The latter caused contamination of soils and water. Based on overall characteristics water from wells and surface stream water mostly can be classified as of the sulphate magnesium type. The application of a chemical equilibrium model to the sampled water showed that copper, phosphate and sulphate concentrations are controlled by copper(II) secondary minerals (pseudomalachite, libethenite and malachite) and gypsum. Nevertheless, groundwater can be used for irrigation and cattle based on quality parameters. Soils and plants (Prunus domestica L., Olea europaea L. spp. europaea and Quercus ilex L.) were collected southeast of the open pit and the exploitation substructures. The soils located in the influence of drainage water that percolated through waste material or exploitation substructures were contaminated with Cu, and Ni was close to the maximum value allowed by Portuguese legislation. These soils, however, did not show elevated Zn and Mn concentrations. The trace element content in plants was within the normal range, with Q. ilex being able to accumulate Mn and to some extent also Ni. Dispersion of trace elements seemed to be limited to a distance 1500 m down from the waste dumps in southeastern direction

    Quercetin enhances UVA-induced DNA damage in a rat fibroblast cell line

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    Ultraviolet A (UVA) radiation from sunlight induces the production of reactive oxygen species (ROS), affecting a variety of cellular targets including the DNA. Quercetin, a flavonol present in many fruits, vegetables and beverages has been reported as a powerful antioxidant with an important role in prevention of carcinogenesis. The use of this compound, in topical formulations, could be of benefit in the prevention of skin damage produced by sunlight exposure. We investigated the effect of quercetin on DNA damage induced by UVA radiation in the rat subcutaneous fibroblast cell line, L929. Cells were irradiated by UVA light for 1h, in the presence of quercetin and DNA damage assessed, in individual cells, by the alkaline single cell gel electrophoresis assay (Comet Assay). Our data showed that the combination of UVA with quercetin, at the three concentrations tested (20, 30 and 50 μM) enhances the level of DNA damage in a concentration-dependent manner. However, this effect seems not to be the same when cells are pre-incubated with quercetin, followed by irradiation, in the absence of the compound. We are investigating the mechanisms behind the observed harmful effect of quercetin together with UVA irradiation and trying to relate it, with the ROS levels, in both experimental conditions. The effect obtained suggests that, despite the well known antioxidant beneficial effects of quercetin in many different situations of oxidative stress, precautions should be taken if we think in the development of topical preparations with this compound, to be used on body areas exposed to sunlight.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/17174/200

    Hyperbaric Oxygen Therapy in Retinal Arterial Occlusion: Epidemiology, Clinical Approach, and Visual Outcomes

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    PURPOSE: To evaluate the efficacy and safety of hyperbaric oxygen therapy (HBOT) in patients with acute retinal artery occlusion (RAO). Secondarily, to analyse the epidemiology and the clinical approach. METHODS: Retrospective study of 13 patients submitted to HBOT between 2013 and 2018. The analysed parameters consisted of: systemic history, time between symptoms onset and treatment, initial approach, number of HBOT sessions, complications of HBOT and best corrected visual acuity-BCVA (of the total sample, central RAO-CRAO-group, and branch RAO-BRAO group). RESULTS: Arterial hypertension was the most prevalent systemic risk factor (53.8%). Initial therapies were 100% normobaric oxygen administration, topical and oral hypotensive medication, eye massage and aspirin. CRAO was observed in 69.2% and BRAO in 30.8% of the cases, with clinically significant visual improvement (a decrease in logMAR of 0.3) in 55.5% and 75%, respectively. Time between symptoms onset and treatment had a median of 9 hours. The median number of HBOT sessions was 7, without complications. CONCLUSIONS: HBOT provide BCVA improvement in patients with RAO, when it is performed in an early time after the symptom onset. It seems to be an effective and safe therapeutic option for a pathology that still remains without approved treatment.info:eu-repo/semantics/publishedVersio

    Task scheduling characterisation in enterprise application integration

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    Cloud computing allows enterprises to incorporate applications and computational resources as services, and thus, enterprises can concentrate on their business processes, without concerning the development, configuration and maintenance of these applications and resources. Integration platforms are one of these services that allow enterprises to integrate applications in order to reduce the maintenance costs and operations of the integration of on-premises platforms. However, high performance on resources offered by the cloud, demands improvement in task scheduling of integration platforms. Our literature review has identified a lack of studies in the field of enterprise application integration, focusing on specificities and vulnerabilities of the task scheduling of integration processes. This is a pioneer work regarding the characterisation of the scheduling of tasks of integration processes. We propose a ranking according to their conceptual models and apply this ranking to five integration processes. Then, we have statistically analysed the influence of each component of their conceptual models on the performance of the execution of these integration processes. We characterise the task scheduling of integration processes and presented a mathematical equation for the makespan as a function of the components of this characterisation. This study can guide software engineers in the optimal task scheduling for integration processes, which can improve the performance runtime systems regarding using the computational resources and result in minimisation of costs of companies.info:eu-repo/semantics/acceptedVersio

    Queue-priority optimized algorithm: a novel task scheduling for runtime systems of application integration platforms

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    The need for integration of applications and services in business processes from enterprises has increased with the advancement of cloud and mobile applications. Enterprises started dealing with high volumes of data from the cloud and from mobile applications, besides their own. This is the reason why integration tools must adapt themselves to handle with high volumes of data, and to exploit the scalability of cloud computational resources without increasing enterprise operations costs. Integration platforms are tools that integrate enterprises’ applications through integration processes, which are nothing but workflows composed of a set of atomic tasks connected through communication channels. Many integration platforms schedule tasks to be executed by computational resources through the First-in-first-out heuristic. This article proposes a Queue-priority algorithm that uses a novel heuristic and tackles high volumes of data in the task scheduling of integration processes. This heuristic is optimized by the Particle Swarm Optimization computational method. The results of our experiments were confirmed by statistical tests, and validated the proposal as a feasible alternative to improve integration platforms in the execution of integration processes under a high volume of data.info:eu-repo/semantics/acceptedVersio

    A cloud-based integration platform for enterprise application integration: a model-driven engineering approach

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    This article addresses major information systems integration problems, approaches, technologies, and tools within the context of Model-Driven Software Engineering. The Guaraná integration platform is introduced as an innovative platform amongst state-of-the-art technologies available for enterprises to design and implement integration solutions. In this article, we present its domain-specific modeling language and its industrial cloud-based web development platform, which supports the design and implementation of integration solutions. A real-world case study is described and analyzed; then, we delve into its design and implementation, to finally disclose ten measures that empirically help estimating the amount of effort involved in the development of integration solutions.info:eu-repo/semantics/acceptedVersio

    Peripheral Artery Disease Patients May Benefit More from Aggressive Secondary Prevention than Aneurysm Patients to Improve Survival

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    BACKGROUND AND AIMS: Although it has become clear that aneurysmal and occlusive arterial disease represent two distinct etiologic entities, it is still unknown whether the two vascular pathologies are prognostically different. We aim to assess the long-term vital prognosis of patients with abdominal aortic aneurysmal disease (AAA) or peripheral artery disease (PAD), focusing on possible differences in survival, prognostic risk profiles and causes of death. METHODS: Patients undergoing elective surgery for isolated AAA or PAD between 2003 and 2011 were retrospectively included. Differences in postoperative survival were determined using Kaplan-Meier and Cox regression analysis. Prognostic risk profiles were also established with Cox regression analysis. RESULTS: 429 and 338 patients were included in the AAA and PAD groups, respectively. AAA patients were older (71.7 vs. 63.3 years, p < 0.001), yet overall survival following surgery did not differ (HR: 1.16, 95% CI: 0.87-1.54). Neither was type of vascular disease associated with postoperative cardiovascular nor cancer-related death. However, in comparison with age- and gender-matched general populations, cardiovascular mortality was higher in PAD than AAA patients (48.3% vs. 17.3%). Survival of AAA and PAD patients was negatively affected by age, history of cancer and renal insufficiency. Additional determinants in the PAD group were diabetes and ischemic heart disease. CONCLUSIONS: Long-term survival after surgery for PAD and AAA is similar. However, overall life expectancy is significantly worse among PAD patients. The contribution of cardiovascular disease towards mortality in PAD patients warrants more aggressive secondary prevention to reduce cardiovascular mortality and improve longevity

    Interactions between Plasmopara viticola infection and stilbene synthesis in leaves and berries of ten 'Cabernet Sauvignon' clones

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    Combining the knowledge that Plasmopara viticola causes considerable damages to Vitis vinifera L. worldwide production and that stilbenes have a regulatory influence on Plasmopara viticola - grapevine interaction, this study compares infection time course and stilbenes production in leaves and berries of ten different clones of 'Cabernet Sauvignon'. Following increasing infection rates, different stilbenes were produced and accumulated in leaves and berries of the same clone. Higher absolute values were found in leaves, where trans-resveratrol reaches up to 8 μg g-1 fw and ε-viniferin up to 30 μg g-1 fw while in berries, the values accumulated only up to a maximum of 3 μg g-1 fw of trans-piceid and 1,5 μg g-1 fw ε-viniferin

    Modelagem de preços de provedores de IaaS utilizando regressão múltipla

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    Uma alternativa para usuários reduzirem custos de aquisição e manutenção de infraestrutura computacional para desenvolver, implementar e executar suas aplicações é a computação em nuvem. Os serviços de computação em nuvem são oferecidos por provedores e podem ser classificados em três modalidades: Platform-as-a-Service (PaaS), Software-as-a-Service (SaaS) e Infrastructure-as-a-Service (IaaS). Em IaaS, os provedores oferecem os serviços divididos em instâncias e o usuário tem à disposição uma máquina virtual com os recursos computacionais que desejar a um determinado valor. O principal desafio enfrentado pelas empresas é escolher, além do provedor, a instância que melhor se adapta as suas necessidades. Frequentemente, estas empresas precisam de uma grande infraestrutura computacional para gerir e aperfeiçoar seus processos de negócio e, diante do alto custo para manter uma infraestrutura local, têm migrado suas aplicações para a nuvem. Este trabalho busca fornecer subsídios capazes de auxiliar as empresas no processo de seleção do melhor provedor/instância para implantar e executar suas soluções de integração na nuvem. Para isso, um estudo preliminar para a elaboração de uma nova proposta de modelagem dos preços das instâncias de máquinas virtuais usando regressão linear é apresentado. Nesta abordagem são considerados os provedores Amazon EC2, Google Compute Engine e Microsoft Windows Azure.info:eu-repo/semantics/acceptedVersio

    An EAI based integration solution for science and research outcomes information management

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    Open Access articleIn this paper we present an Enterprise Application Integration (EAI) based proposal for research outcomes information management. The proposal is contextualized in terms of national and international science and research outcomes information management, corresponding supporting information systems and ecosystems. Information systems interoperability problems, approaches, technologies and tools are presented and applied to the research outcomes information management case. A business and technological perspective is provided, including the conceptual analysis and modelling, an integration solution based in a Domain-Specific Language (DSL) and the orchestration engine to execute the proposed solution. For illustrative purposes, the role and information system needs of a research unit is assumed as the representative case
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