300 research outputs found

    Papel de nano-aditivos na funcionalização de argamassas

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    A manutenção da qualidade do ar no interior dos edifícios é um dos aspetos mais relevantes da construção sustentável e tem forte impacto no nível de conforto dos utilizadores. A introdução de nano-aditivos em materiais de construção permite modificar propriedades fundamentais destes materiais convencionais, com o objetivo de proporcionar novas funcionalidades. Neste trabalho apresentam-se os resultados obtidos com o desenvolvimento de argamassas funcionais que pretendem melhorar a qualidade do ar interior e contribuir para a poupança energética dos edifícios. As formulações foram optimizadas com vista à sua aplicação em construção nova ou reabilitação

    Deep Convolutional Autoencoders as Generic Feature Extractors in Seismological Applications

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    The idea of using a deep autoencoder to encode seismic waveform features and then use them in different seismological applications is appealing. In this paper, we designed tests to evaluate this idea of using autoencoders as feature extractors for different seismological applications, such as event discrimination (i.e., earthquake vs. noise waveforms, earthquake vs. explosion waveforms, and phase picking). These tests involve training an autoencoder, either undercomplete or overcomplete, on a large amount of earthquake waveforms, and then using the trained encoder as a feature extractor with subsequent application layers (either a fully connected layer, or a convolutional layer plus a fully connected layer) to make the decision. By comparing the performance of these newly designed models against the baseline models trained from scratch, we conclude that the autoencoder feature extractor approach may only perform well under certain conditions such as when the target problems require features to be similar to the autoencoder encoded features, when a relatively small amount of training data is available, and when certain model structures and training strategies are utilized. The model structure that works best in all these tests is an overcomplete autoencoder with a convolutional layer and a fully connected layer to make the estimation

    Coevolution creates complex mosaics across large landscapes

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    The spatial distribution of populations can influence the evolutionary outcome of species interactions. The variation in direction and strength of selection across local communities creates geographic selection mosaics that, when combined with gene flow and genomic processes such as genome duplication or hybridization, can fuel ongoing coevolution. A fundamental problem to solve is how coevolution proceeds when many populations that vary in their ecological outcomes are connected across large landscapes. Here we use a lattice model to explore this problem. Our results show that the complex interrelationships among the elements of the geographic mosaic of coevolution can lead to the formation of clusters of populations with similar phenotypes that are larger than expected by local selection. Our results indicate that neither the spatial distribution of phenotypes nor the spatial differences in magnitude and direction of selection alone dictate coevolutionary dynamics: the geographic mosaic of coevolution affects formation of phenotypic clusters, which in turn affect the spatial and temporal dynamics of coevolution. Because the formation of large phenotypic clusters depends on gene flow, we predict that current habitat fragmentation will change the outcomes of geographic mosaics, coupling spatial patterns in selection and phenotypes1942217229We acknowledge the funding provided by the European Union Seventh Framework Programme (FP7/2007–2013; grant agreement 289384 [L.D.F.]), the São Paulo Research Foundation (grants 2009/54422-8 [P.R.G.], 2016/06054-3 [M.A.M.A.], and 2015/26989-4 [L.D.F.]), the National Council of Scientific and Technological Development (M.A.M.A. and P.L.-C.), and the National Science Foundation (DEB0839853 [J.N.T.]

    Novos materiais de construção com tecnologias avançadas

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    Este artigo pretende apenas dar um contributo, assinalando alguns exemplos em que se tem vindo a trabalhar e que refletem o uso de tecnologias avançadas na formulação e funcionalidade de materiais de construção tradicionais. Um exemplo claro é o uso de aditivos que induzem novas funções e que muitos deles pertencem ao grupo denominado como nanomateriais. A sua adição coloca quase sempre problemas de incorporação e que requerem um trabalho de ajuste das formulações e comportamentos no estado fresco ou endurecido. Este trabalho de investigação é muitas vezes essencial para a otimização das funções que se pretendem que os materiais de construção venham a demonstrar. Neste grupo de investigação, resultante da cooperação entre centros de I&D e empresas em projetos de colaboração diversos ao longo dos últimos anos, tem-se vindo a focar na introdução de novas funções em materiais de construção tradicionais, para que ganhem um papel ativo em domínios como o do conforto térmico ou da qualidade ambiental, dois pilares essenciais para uma construção mais sustentável

    Application of endograft to treat thoracic aortic pathologies: A single center experience

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    PurposeTo evaluate our experience of thoracic endoluminal graft (ELG) repair of various thoracic aortic pathologies using a commercially available device approved by the Food and Drug Administration. Our patient population includes patients eligible for open surgical repair and those with prohibitive surgical risk.MethodsFrom March 1998 to March 2006, endovascular stent repair of the thoracic aorta was performed on 406 patients with 324 patients (median age 72; 200 male) receiving the Gore Excluder endograft. Patient demographics, procedural characteristics, complications, including endoleak, spinal cord ischemia, and mortality, were retrospectively reviewed during follow-up. All patients were followed with chest computer tomography at 6 months and yearly. Statistical analysis was performed utilizing the SPSS Windows 11.0 program. Logistic regression (univariate) analysis used to identify risk factors for paraplegia; analysis of variance (ANOVA) for endoleak distribution; and χ2 used to analyze variables. Survival analysis was done using SAS version 9.1 (SAS Institute, Cary, NC).ResultsThree hundred twenty-four patients were treated with Gore Excluder graft between March 1998 and March 2006. One hundred fifty-seven patients (48.5%) had atherosclerotic aneurysms, 82 (25.3%) had dissections type B (DTB), 34 (10.5%) had penetrating ulcers (PU), 26 (8.0%) with pseudoaneurysms (PSA), 11 (3.4%) had transections (MVAT), 9 (2.8%) aorto-bronchial fistulas (AoBF), 4 (1.2%) embolization, and 1 (0.3%) aorto-esophageal fistula (AoEF). Preoperative aneurysm sac size in TAA ranged from 5 to 12 centimeters, average size 6.3 cm. Sac shrinkage occurred in 65% (102 of 157) of patients. Average postoperative sac size of 5.4 cm in a mean follow-up of 20.4 months. One hundred cases (31.5%) were nonelective; 49 (15.1%) were ruptures. Overall complication was 22.7%, 14.2% (46) in elective cases and 8.5% (28) in nonelective cases. Paraplegia occurred in five (1.5%) patients and paresis in three (0.9%); two of the latter improved and one resolved completely prior to discharge. Incidence of paraplegia was statistically significant (P value < .05) with retroperitoneal approach, perioperative blood loss greater than 1000 cc, and aortic coverage greater than 40 cm. Early endoleaks included 18 (5.5%) type I, four (1.2%) type II, and two (0.6%) type III. Thirty-day mortality was 5.5% (18 related deaths, including three intraoperative deaths). A log rank test did not find statistical differences in actuarial survival with 30-day related mortality between TAA and other pathologies (P = .29) or between DTB and other pathologies (P = .97). Late mortality was 9.6% with 31 unrelated deaths. Follow-up ranged between 1 month and 70 months, average 17 months.ConclusionsEndoluminal grafting is a feasible alternative to open surgical repair for thoracic aortic pathologies. After more than 300 cases, 30-day morbidity and mortality compares favorably with open repair. Paraplegia remains low as a complication and increases in incidence with retroperitoneal approach, increased perioperative blood loss, and increased aortic coverage

    Organic consequences of ileal transposition in rats with diet-induced obesity

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    INTRODUCTION: The clinical management of metabolic syndrome - especially diabetes mellitus type 2 - is notoriously complex due to the progressive nature of this disease. At present, there is a need for a surgical procedure that is effective for the treatment of diabetes mellitus type 2, even in non-obese individuals. The isolated ileal transposition theory could lead to an effective alternative therapy. This intervention has not yet been performed in humans, and there are no reports of its use in an experimental model of diet-induced metabolic syndrome.&#xd;&#xa; OBJECTIVES: The objective of this study is to evaluate the physiological effects of ileal transposition in rats with diet-induced metabolic syndrome. The effects of this procedure on glucose and lipid metabolism will be assessed. &#xd;&#xa;METHODS: Forty 12-week-old male rats (albino Rattus norvegicus, Wistar, 2BAW, heterogeneous) will be divided into four groups of 10 animals each: the ileal transposition group (TG) comprising animals on a hypercaloric-hyperlipidic diet; the sham group (SG) containing animals that receive the same diet and undergo the sham surgery; control group 1 (CG1), which will receive a hypercaloric-hyperlipidic diet and will not undergo surgery; and control group 2 (CG2), which will consume standard feed and will not undergo surgery. The surgeries will be performed in 20-week-old animals. Blood samples for laboratory testing will be collected from 12-week-old animals on the day of surgery and after eight postoperative weeks, following determination of the weights of the animals and the administration of anesthesia. The levels of serum glucose, insulin, triglycerides, total cholesterol and fractions, glucagon-like peptide-1, C-peptide and glycated hemoglobin will be assessed in all of the animals. The insulin tolerance test will be performed using PRISMA software, and insulin resistance will be calculated by the HOMA-IR indirect test. On specific days, two 20-week-old rats will be separated and randomly distributed in TG and SG. These animals will be followed until the eighth postoperative week. Subsequently, they will be euthanized, and the retroperitoneal and periepididymal fat deposits will be collected and weighed using a precision scale. In addition, the pancreas, liver and intestinal segments will be sent for pathological and immunohistochemical studies.&#xd;&#xa

    SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

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    Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated

    SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

    Get PDF
    Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated

    Optimal behavior of responsive residential demand considering hybrid phase change materials

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    Due to communication and technology developments, residential consumers are enabled to participate in Demand Response Programs (DRPs), control their consumption and decrease their cost by using Household Energy Management (HEM) systems. On the other hand, capability of energy storage systems to improve the energy efficiency causes that employing Phase Change Materials (PCM) as thermal storage systems to be widely addressed in the building applications. In this paper, an operational model of HEM system considering the incorporation of more than one type of PCM in plastering mortars (hybrid PCM) is proposed not only to minimize the customerâ s cost in different DRPs but also to guaranty the habitantsâ  satisfaction. Moreover, the proposed model ensures the technical and economic limits of batteries and electrical appliances. Different case studies indicate that implementation of hybrid PCM in the buildings can meaningfully affect the operational pattern of HEM systems in different DRPs. The results reveal that the customerâ s electricity cost can be reduced up to 48% by utilizing the proposed model.The work of M. Shafie-khah and J.P.S. Catalão was supported by FEDER funds through COMPETE and by Portuguese funds through FCT, under FCOMP-01-0124-FEDER-020282 (Ref. PTDC/EEA-EEL/118519/2010) and UID/CEC/50021/2013, and also by the EU 7th Framework Programme FP7/2007-2013 under Grant agreement No. 309048 (project SiNGULAR)
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