144 research outputs found

    Better late than never, but never late is better: risk assessment of nuclear power construction projects

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    This work seeks to evaluate overnight construction costs (OCC) and lead-time escalation of nuclear power construction projects from 1955 to 2016. To this end, a comprehensive database of commercial Light Water Reactors (LWR) was developed and a statistical analysis was conducted. Findings reveal a significant delay in lead-time, especially for the last generation reactors constructed from 2010s, with 3/4 of the sample showing significant construction delays. This results in an escalation of capital costs rather than in a decline. Average OCC of newer reactors is 60% higher than the ones implemented in the earlier stages of the nuclear era. This suggests a discontinuity of the learning curve for both OCC and lead-time, which threats the market and financial sustainability of current and future nuclear energy projects. Although this is a general trend, this discontinuity is country specific and, thus, induced by national policies and regulatory frameworks. Therefore, the role of nuclear technology as an alternative to cope with the need for a decarbonisation of the power sector must be better evaluated, taking into account the real cost impacts of nuclear technology implementation.- This work was funded by the Brazilian National Council for Scientific and Technological Development agency (CNPq) (166074/2015-2) and the Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under the project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263). Authors would like to acknowledge Rafael Garaffa for his helpful advices about processing data with R statistical software and data analysis. Authors are also thankful to the comments of anonymous reviewers. Special thanks to the Grantham Institute and Imperial College London media office for assisting in publicising the findings of the paper

    Low-carbon scenarios for the Brazilian power system

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    The Brazilian power generation sector faces a paradigm change driven, on one hand, by a shift from a hydropower dominated mix and, on the other, by international goals for reducing greenhouse gases emissions. The objective of this work was to evaluate five scenarios for the Brazilian power system until 2050 using a multi-criteria decision analysis tool. These scenarios include a baseline trend and low carbon policy scenarios based on carbon taxes and carbon emission limits. To support the applied methodology, a questionnaire was elaborated to integrate the perceptions of experts on the scenario evaluation process. Taking into account the results from multi-criteria analysis, scenario preference followed the order of increasing share of renewables in the power system. The preferable option for the future Brazilian power system is a scenario where wind and biomass have a major contribution. The robustness of the multi-criteria tool applied in this study was tested by a sensitivity analysis. This analysis demonstrated that, regardless the respondents’ preferences and backgrounds, scenarios with higher shares of fossil fuel sources are the least preferable option, while scenarios with major contributions from wind and biomass are the preferable option to supply electricity in Brazil through 2050.This research was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263)

    Decoding negative affect personality trait from patterns of brain activation to threat stimuli

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    INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts

    Scenarios for the future Brazilian power sector based on a multi-criteria assessment

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    The Brazilian power generation sector faces a paradigm change driven by, on one hand, a shift from a hydropower dominated mix and, on the other hand, international goals for reducing greenhouse gas emissions. The objective of this work is to evaluate five scenarios for the Brazilian power sector until 2050 using a multi-criteria decision analysis tool. These scenarios include a baseline trend and low carbon policy scenarios based on carbon taxes and carbon emission limits. To support the applied methodology, a questionnaire was elaborated to integrate the perceptions of experts on the scenario evaluation process. Considering the results from multi-criteria analysis, scenario preference followed the order of increasing share of renewables in the power sector. The preferable option for the future Brazilian power sector is a scenario where wind and biomass have a major contribution. The robustness of the multi-criteria tool applied in this study was tested by a sensitivity analysis. This analysis demonstrated that, regardless of the respondents' preferences and backgrounds, scenarios with higher shares of fossil fuel sources are the least preferable option, while scenarios with major contributions from wind and biomass are the preferable option to supply electricity in Brazil through 2050.The research that allowed the publication of this paper has been produced with the financial assistance of the European Union in the context of the CLIMACAP project (EuropeAid/131944/C/SER/Multi) and of the U.S. Agency for International Development and U.S. Environmental Protection Agency in the context of the LAMP project (under Interagency Agreements DW89923040 and DW89923951US). The contents of this publication are the sole responsibility of the authors and can in no way be taken to reflect the views of the European Union or the U.S. government. The authors would like to thank the feedback and efforts from all CLIMACAP and LAMP project partners for enabling the research results reported in this article. This research was also supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP-European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263).info:eu-repo/semantics/publishedVersio

    Stent for Life in Portugal: This initiative is here to stay

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    AIMS: Portugal has one of the lowest rates of primary percutaneous coronary intervention (p-PCI) in Western Europe. This study assessed the progress of Portuguese p-PCI performance indicators one year after Portugal joined the Stent for Life (SFL) initiative. METHODS AND RESULTS: Two national surveys were carried out, each covering a period of one month: the first when Portugal joined the SFL in 2011 (Moment Zero), and the second one year later (Moment One). A total of 397 consecutive patients with probable ST-segment elevation myocardial infarction were enrolled (201 at Moment Zero and 196 at Moment One) from 15 centers. During this period, the number of patients who arrived at a local hospital without p-PCI decreased (62-47%; p=0.004) and transportation to a p-PCI hospital by the National Institute for Medical Emergencies (INEM) increased significantly (13-37%; p<0.001). Shorter times to revascularization were observed, due to shorter patient delay (118-102 min; p=0.008). Door-to-balloon delay and system delay remained unchanged. CONCLUSIONS: Improvements in performance indicators for p-PCI demonstrate the success of the first year of the local SFL plan, which was mainly focused on raising public awareness of the need to use the INEM emergency services, which has reduced patient delay, and on improving secondary transportation

    Clonal expansion across the seas as seen through CPLP-TB database: A joint effort in cataloguing Mycobacterium tuberculosis genetic diversity in Portuguese-speaking countries

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    This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).Tuberculosis (TB) remains a major health problem within the Community of Portuguese Language Speaking Countries (CPLP). Despite the marked variation in TB incidence across its member-states and continued human migratory flux between countries, a considerable gap in the knowledge on the Mycobacterium tuberculosis population structure and strain circulation between the countries still exists. To address this, we have assembled and analysed the largest CPLP M. tuberculosis molecular and drug susceptibility dataset, comprised by a total of 1447 clinical isolates, including 423 multidrug-resistant isolates, from five CPLP countries. The data herein presented reinforces Latin American and Mediterranean (LAM) strains as the hallmark of M. tuberculosis populational structure in the CPLP coupled with country-specific differential prevalence of minor clades. Moreover, using high-resolution typing by 24-loci MIRU-VNTR, six cross-border genetic clusters were detected, thus supporting recent clonal expansion across the Lusophone space. To make this data available to the scientific community and public health authorities we developed CPLP-TB (available at http://cplp-tb.ff.ulisboa.pt), an online database coupled with web-based tools for exploratory data analysis. As a public health tool, it is expected to contribute to improved knowledge on the M. tuberculosis population structure and strain circulation within the CPLP, thus supporting the risk assessment of strain-specific trends.info:eu-repo/semantics/publishedVersio

    Targeting Neutrophils to Prevent Malaria-Associated Acute Lung Injury/Acute Respiratory Distress Syndrome in Mice

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    Malaria remains one of the greatest burdens to global health, causing nearly 500,000 deaths in 2014. When manifesting in the lungs, severe malaria causes acute lung injury/acute respiratory distress syndrome (ALI/ARDS). We have previously shown that a proportion of DBA/2 mice infected with Plasmodium berghei ANKA (PbA) develop ALI/ARDS and that these mice recapitulate various aspects of the human syndrome, such as pulmonary edema, hemorrhaging, pleural effusion and hypoxemia. Herein, we investigated the role of neutrophils in the pathogenesis of malaria-associated ALI/ARDS. Mice developing ALI/ARDS showed greater neutrophil accumulation in the lungs compared with mice that did not develop pulmonary complications. In addition, mice with ALI/ARDS produced more neutrophil-attracting chemokines, myeloperoxidase and reactive oxygen species. We also observed that the parasites Plasmodium falciparum and PbA induced the formation of neutrophil extracellular traps (NETs) ex vivo, which were associated with inflammation and tissue injury. The depletion of neutrophils, treatment with AMD3100 (a CXCR4 antagonist), Pulmozyme (human recombinant DNase) or Sivelestat (inhibitor of neutrophil elastase) decreased the development of malaria-associated ALI/ARDS and significantly increased mouse survival. This study implicates neutrophils and NETs in the genesis of experimentally induced malaria-associated ALI/ARDS and proposes a new therapeutic approach to improve the prognosis of severe malaria

    Interactions between global climate change strategies and local air pollution: lessons learnt from the expansion of the power sector in Brazil

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    This study examines the interactions between local air pollutants and greenhouse gas emissions to assess potential synergies and trade-offs between local environmental pollution and climate policies, using the power generation sector in Brazil under different carbon scenarios up to 2050 as a case study. To this end, an integrated approach was developed, combining energy scenarios under different carbon mitigation targets and a local air pollution assessment model, tailored to the context of the Brazilian power sector. Results reveal that there are deep interactions between climate change mitigation and local air pollution abatement strategies. Increasing the diffusion of low-carbon technologies results in both mitigation of climate change and lower terrestrial acidification potential impacts, due to the rapid phase-out of fossil fuel power technologies. However, local air pollution indicators for particulate matter formation and human toxicity may rise in response to greenhouse gas emission mitigation constraints, indicating the existence of potential trade-offs. Some of these trade-offs can be offset by introducing available end-of-pipe pollution control measures reinforced by dedicated air quality policies
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