9 research outputs found

    Dignitas: uso de reputação como moeda para avaliar a sensorização humana em cidades inteligentes

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    We live in an increasingly digital world, where Smart Cities have become a reality. One of the characteristics that make these cities smart is their ability to gather information and act upon it, improving their citizens lives. In this work, we present our system, Dignitas. A blockchain-based reputation system that allows citizens of a Smart City to assess the truthiness of information posted by other citizens. This assessment is based on a bet that reporters make, and all of those who agreed with him, that puts their gathered reputation at stake. This use of Reputation as a currency is a novel idea that allowed us to build an anonymous system. Using blockchain we were able to have multiple authorities, working with each other to make the system secure and thus avoiding centralized schemes. Our work was focused on developing our idea, a proof of concept, and testing the viability of our new solution.Vivemos num mundo cada vez mais digital, onde as cidades inteligentes passaram a ser uma realidade. Uma das características que permite a estas cidades serem inteligentes é a capacidade de adquirir informação e agir sobre ela, melhorando a vida de todos os cidadãos. Neste trabalho apresentamos o nosso sistema, Dignitas, um sistema de reputação baseado numa blockchain que permite aos cidadãos de uma cidade inteligente avaliar informação relatada por outras pessoas. Esta avaliação é baseada numa aposta feita pelo relator, e por todos os que com ele concordam, em que põe em risco parte da sua Reputação no sistema. Este uso da Reputação como uma moeda é o que nos permite construir um sistema anónimo. O uso de uma blockchain permite-nos ter múltiplas autoridades responsáveis, evitando por isso o uso de esquemas centralizados. O nosso trabalho focou-se em desenvolver a nossa ideia, uma prova de conceito, e testar a viabilidade desta nossa nova solução.Mestrado em Engenharia de Computadores e Telemátic

    Enhancing locality in Java based irregular applications

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    Improving locality of memory accesses in current and future multi-core platforms is a key to efficiently exploit those platforms. Irregular applications, which operate on pointer-based data structures, are hard to optimize in modern computer architectures due to their intrinsic unpredictable patterns of memory accesses. In this paper we explore a memory locality-driven set of data-structures in order to attenuate the memory bandwidth limitations from typical irregular algorithms. We identify the inefficiencies in the standard Java implementation of a priority-queue as one of the main memory limitations in Prim’s Minimal Spanning Tree algorithm. We also present a priority-queue using the data layout inspired in Van Emde Boas for ordering heaps. We also implement optimizations in the graph data-structure and explore ways to efficiently combine it with the memory-efficient priority-queue. In order to improve efficiency in both case studies we had to transform the data-structures in the form of array of pointer into arrays of structures or structure of arrays

    Impact of data structure layout on performance

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    One key issue to design parallel applications that scale on multicore systems is how to overcome the memory bottleneck. This paper presents a study of the impact of data structure layouts in locality of memory references, providing insights on strategies to ameliorate the memory bottleneck. The paper compares the performance of Java and C++ STL collections and presents the impact of locality of reference optimisations in a molecular dynamics simulation case study. The case study shows that the selected data structure layout has impact on single core performance, becoming a critical factor in the application scalability on multicore systems. Moreover, data collections provided in the Java language compromise performance due to pointer chasing and lack of spatial locality of memory references.This work is funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Fundac a o para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) within projects FCOMP-01-0124- FEDER-010152 and FCOMP-01-0124-FEDER-011413

    Viral genetic clustering and transmission dynamics of the 2022 mpox outbreak in Portugal

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    Pathogen genome sequencing during epidemics enhances our ability to identify and understand suspected clusters and investigate their relationships. Here, we combine genomic and epidemiological data of the 2022 mpox outbreak to better understand early viral spread, diversification and transmission dynamics. By sequencing 52% of the confirmed cases in Portugal, we identified the mpox virus sublineages with the highest impact on case numbers and fitted them into a global context, finding evidence that several international sublineages probably emerged or spread early in Portugal. We estimated a 62% infection reporting rate and that 1.3% of the population of men who have sex with men in Portugal were infected. We infer the critical role played by sexual networks and superspreader gatherings, such as sauna attendance, in the dissemination of mpox virus. Overall, our findings highlight genomic epidemiology as a tool for the real-time monitoring and control of mpox epidemics, and can guide future vaccine policy in a highly susceptible population.info:eu-repo/semantics/publishedVersio

    A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

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    Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

    SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

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    Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

    Modelling and numerical simulation of magnetostrictive materials for reduction of friction

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    This study aims to enhance the multifunctional properties in top piston rings by adding magnetostrictive materials to reduce friction between them and the cylinder lining. The magnetostrictive effect will create mechanical deformations in piston rings, with consequent friction reduction. The present study consisted of a finite element analysis (FEA), using COMSOL Multiphysics® software, where both the amplitude of deformation and the reduction of the contact forces were analysed. These variables are useful to predict the ability to introduce mechanical vibrations in piston rings that can lead to the reduction of friction. The results showed a reduction of the contact force below 4%, and deformation amplitudes in the sliding plane of 6.50 μm and 3.20 μm, approximately, in the axial and circumferential directions, respectively. Those results are promising, enhancing the potential of smart materials and magnetostrictive effects to create mechanical vibrations and reduce friction in piston ring structures

    Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

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    International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora
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