37 research outputs found

    Controlo automático da plataforma de ensaios de concentradores solares da Universidade de Évora

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    A Universidade de Évora construiu em 2014, no Polo da Mitra, a Plataforma de Ensaios de Concentradores Solares (PECS) com o objetivo da realização de ensaios sob as exigências da norma ISO9806. Esta exige o controlo de determinadas variáveis tais como ângulos de incidência solar, caudal mássico e temperatura de entrada no coletor durante a realização dos ensaios. Nesta tese analisaram-se todos os componentes existentes na plataforma e avaliou-se a adequação dos mesmos para a realização de ensaios cumprindo as exigências da norma. Para tal, desenvolveu-se um novo software para aquisição dados, controlo da movimentação da plataforma e das variáveis do circuito hidráulico. Desenvolveram-se controladores para o caudal mássico e para a temperatura na entrada do coletor, sendo o primeiro construído com base em dados experimentais e o segundo projetado segundo um modelo. Além disso realizaram-se algumas melhorias na plataforma com vista a facilitar a operação da mesma; Abstract: Automatic control of Solar Concentrators Tests Platform of University of Évora In 2014, the University of Évora built, at Pólo da Mitra, the Solar Concentrator Testing Platform (PECS) with the objective of conducting tests under the requirements of ISO9806. This requires the control of certain variables such as solar incidence angles, mass flow and inlet temperature in the collector during the tests. In this thesis all the existing components of the platform were analyzed as well as its suitability to perform the tests following the standard requirements. A new software was developed for data acquisition, platform movement control and management of the hydraulic circuit variables. Mass flow and inlet temperature controllers were developed, the first was built based on experimental data whereas the second was modelled. In addition, some improvements were made to the platform to facilitate its operation

    Diabetes and Cardiovascular Disease: prognosis five years after percutaneous revascularization

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    Fundamentos: O diabetes mellitus (DM) é reconhecidamente fator de risco cardiovascular. Sabendose que a intervenção coronariana percutânea (ICP) melhora o prognóstico da doença coronariana (DC), pretendemos verificar se esse efeito é similar em doentes diabéticos (D) e não diabéticos (ND). Objetivo: Analisar o prognóstico em longo prazo do DM em pacientes submetidos a ICP. Métodos: Estudo de coorte, unicêntrico, retrospectivo, envolvendo pacientes consecutivos submetidos à ICP, eletiva ou de urgência, entre janeiro 2002 e dezembro 2003. Definiram-se dois grupos: pacientes com DM (D) e sem DM (ND). Compararam-se as variáveis clínicas e angiográficas da ICP com o resultado clínico ao final de cinco anos. Definiram-se como eventos maiores cardiovasculares (EMC): morte, nova síndrome coronariana aguda, acidente vascular encefálico (AVE) e nova revascularização cirúrgica ou ICP. Foram ainda avaliadas as taxas de trombose de stent, revascularização do vaso-alvo (RVA) e revascularização da lesão-alvo (RLA). Resultados: O seguimento em cinco anos foi 94%. Foram realizadas 446 ICP em 406 pacientes, média de idade =63,0±11 anos, 70,4% masculino. Destes, 128 (31,5%) eram do grupo D. Em cinco anos o valor de EMC foi 50,7% para D e 36,7% para N. Encontrou-se mortalidade global de 28,1% vs. 14,4% (p=0,0016) e mortalidade cardiovascular de 15,6% vs. 8,3% (p=0,039), respectivamente, para D vs. ND. Os restantes parâmetros não foram estatisticamente significativos. Não houve diferenças em termos de trombose de stent e tipos de stent utilizados nos dois grupos.Background: Diabetes Mellitus (DM) is a recognized cardiovascular risk factor, and knowing that percutaneous coronary intervention (PCI) improves prognoses of coronary artery disease (CAD), we intend to ascertain whether this effect is similar in diabetic (D) and nondiabetic (ND) patients. Objective: To analyze the long term impact of DM in patients undergoing PCI. Methods: Retrospective unicentric cohort study of consecutive patients undergoing elective or urgent PCI between January 2002 and December 2003, divided into two groups: diabetic (D) and non-diabetic (ND). Clinical, angiographic and coronary intervention PCI profiles were compared to clinical outcome at 5 years. Major cardiovascular events (MACE) were defined as death, new acute coronary syndrome (ACS), stroke (S), and new surgical (CABG) or percutaneous (PCI) revascularization. The stent thrombosis, target vessel revascularization (TVR) and target lesion revascularization (TLR) rates were also evaluated. Results: The five year follow-up rate was 94%. During the study, 446 PCIs were performed on 406 patients; 63.0±11 years old, 70.4% male. Among them, 128 (31.5%) were D. At the five-year follow-up, the MACE rate was 50.7% for D and 36.7% for ND (p=0.01). The global mortality rates were 28.1% vs 14.4% (p=0.0016) and the cardiovascular mortality rates were 15.6% vs. 8.3% (p=0.039) for D and ND respectively. The remaining parameters were not statistically significant. No differences were noted between stent thrombosis and the stent types used in both groups.info:eu-repo/semantics/publishedVersio

    Integrated monitoring of mola mola behaviour in space and time

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    Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of finescale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) videorecorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (r(s) = 0.184, p < 0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's finescale behaviour observed over a two weeks in May 2014

    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

    Pervasive gaps in Amazonian ecological research

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    Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal

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    Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
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