34 research outputs found

    Proper Hamiltonian Cycles in Edge-Colored Multigraphs

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    A cc-edge-colored multigraph has each edge colored with one of the cc available colors and no two parallel edges have the same color. A proper Hamiltonian cycle is a cycle containing all the vertices of the multigraph such that no two adjacent edges have the same color. In this work we establish sufficient conditions for a multigraph to have a proper Hamiltonian cycle, depending on several parameters such as the number of edges and the rainbow degree.Comment: 13 page

    Aprendizagem colaborativa versus aprendizagem individual em aula de Língua Inglesa : Diferenças de desempenho na utilização de um hipertexto de flexibilidade cognitiva

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    Dissertação de Mestrado em Educação Multimédia apresentada à Faculdade de Ciências da Universidade do PortoO presente estudo teve como objectivo principal averiguar qual a melhor estratégia aprendizagem colaborativa ou individual para a leccionação de um conto em aula de língua inglesa através de um Hipertexto de Flexibilidade Cognitiva.O conteúdo seleccionado foi o conto Dingo de F. Bennett, obra de leitura extensiva adoptada na escola onde a autora desta investigação é professora.O Hipertexto de Flexibilidade Cognitiva utilizado para a leccionação do conto foi construído de acordo com os princípios da Teoria da Flexibilidade Cognitiva de Rand Spiro e teve como base a aplicação DIDAKTOS, da autoria de Moreira, Almeida e Raposo e propriedade da Universidade de Aveiro, aplicação essa também desenvolvida de acordo com a citada teoria.Os sujeitos foram 20 alunos da investigadora provenientes de duas turmas do 11º ano da Escola ES/3 Dr. Joaquim Gomes Ferreira Alves, Valadares, no ano lectivo 2001/2002.Após ter sido feito um estudo introdutório do conto, de forma igual nas duas turmas, iniciou-se o estudo mais aprofundado da obra com auxílio do Hipertexto de Flexibilidade Cognitiva Dingo, desta vez com duas estratégias de aula diferentes. Assim, um grupo experimental trabalhou com esta aplicação de forma colaborativa através de actividades organizadas de acordo com os princípios básicos da aprendizagem cooperativa e um grupo de controlo trabalhou com o mesmo hipertexto de forma individual.O estudo compreendeu nove sessões, sete das quais implicaram um contacto directo com o Hipertexto de Flexibilidade Cognitiva.Para efeitos de avaliação quantitativa foram utilizados um pré-teste e um pós-teste. Estes dois instrumentos permitiram comparar as médias dos dois grupos após o tratamento, assim como os ganhos de aprendizagem obtidos pelos alunos em geral e pelos alunos mais fracos de cada grupo. Dois outros instrumentos de avaliação, um diário e um questionário, permitiram avaliar questões de carácter qualitativo, nomeadamente a atitude dos sujeitos perante o Hipertexto de ..

    Comparison of machine learning algorithms for wildland-urban interface fuelbreak planning integrating ALS and UAV-Borne LiDAR data and multispectral images

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    Producción CientíficaControlling vegetation fuels around human settlements is a crucial strategy for reducing fire severity in forests, buildings and infrastructure, as well as protecting human lives. Each country has its own regulations in this respect, but they all have in common that by reducing fuel load, we in turn reduce the intensity and severity of the fire. The use of Unmanned Aerial Vehicles (UAV)-acquired data combined with other passive and active remote sensing data has the greatest performance to planning Wildland-Urban Interface (WUI) fuelbreak through machine learning algorithms. Nine remote sensing data sources (active and passive) and four supervised classification algorithms (Random Forest, Linear and Radial Support Vector Machine and Artificial Neural Networks) were tested to classify five fuel-area types. We used very high-density Light Detection and Ranging (LiDAR) data acquired by UAV (154 returns·m−2 and ortho-mosaic of 5-cm pixel), multispectral data from the satellites Pleiades-1B and Sentinel-2, and low-density LiDAR data acquired by Airborne Laser Scanning (ALS) (0.5 returns·m−2, ortho-mosaic of 25 cm pixels). Through the Variable Selection Using Random Forest (VSURF) procedure, a pre-selection of final variables was carried out to train the model. The four algorithms were compared, and it was concluded that the differences among them in overall accuracy (OA) on training datasets were negligible. Although the highest accuracy in the training step was obtained in SVML (OA=94.46%) and in testing in ANN (OA=91.91%), Random Forest was considered to be the most reliable algorithm, since it produced more consistent predictions due to the smaller differences between training and testing performance. Using a combination of Sentinel-2 and the two LiDAR data (UAV and ALS), Random Forest obtained an OA of 90.66% in training and of 91.80% in testing datasets. The differences in accuracy between the data sources used are much greater than between algorithms. LiDAR growth metrics calculated using point clouds in different dates and multispectral information from different seasons of the year are the most important variables in the classification. Our results support the essential role of UAVs in fuelbreak planning and management and thus, in the prevention of forest fires.Ministerio de Economía, Industria y Competitividad (DI-16-08446; DI-17-09626; PTQ-16-08411; PTQ- 16-08633)European Commission through the project ‘MySustainableForest’ (H2020-EO-2017; 776045

    Definite and indeterminate nonalcoholic steatohepatitis share similar clinical features and prognosis: A longitudinal study of 1893 biopsy-proven nonalcoholic fatty liver disease subjects

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    [Background and Aim] Histological score systems may not fully capture the essential nonalcoholic steatohepatitis (NASH) features, which is one of the leading causes of screening failure in clinical trials. We assessed the NASH distribution and its components across the fibrosis stages and their impact on the prognosis and their relationship with the concept of metabolic-associated fatty liver disease (MAFLD).[Methods] Spanish multicenter study including 1893 biopsy-proven nonalcoholic fatty liver disease (NAFLD) patients from HEPAmet registry. NASH was diagnosed by NAS score ≥4 (including steatosis, ballooning and lobular inflammation) and fibrosis by Kleiner score. The presence of MAFLD was determined. Progression to cirrhosis, first episode of decompensated cirrhosis and death were collected during the follow-up (4.7 ± 3.8 years).[Results] Fibrosis was F0 34.3% (649/1893), F1 27% (511/1893), F2 16.5% (312/1893), F3 15% (284/1893) and F4 7.2% (137/1893). NASH diagnosis 51.9% (982/1893), and its individual components (severe steatosis, ballooning and lobular inflammation), increased from F0 (33.6%) to F2 (68.6%), and decreased significantly in F4 patients (51.8%) (P = .0001). More than 70% of non-NASH patients showed some inflammatory activity (ballooning or lobular inflammation), showing a similar MAFLD rate than NASH (96.2% [945/982] vs. 95.2% [535/562]) and significantly higher than nonalcoholic fatty liver (NAFL) subjects (89.1% [311/349]) (P < .0001). Progression to cirrhosis was similar between NASH (9.5% [51/539]) and indeterminate NASH (7.9% [25/316]), and higher than steatosis (5% [14/263]) (logRank 8.417; P = .015). Death and decompensated cirrhosis were similar between these.[Conclusions] The prevalence of steatohepatitis decreased in advanced liver disease. However, most of these patients showed some inflammatory activity histologically and had metabolic disturbances. These findings should be considered in clinical trials whose main aim is to prevent cirrhosis progression and complications, liver transplant and death.This project has been partially funded by the ‘Consejería de Salud de la Junta de Andalucía’ (PI-0075-2014) and the ‘Spanish Ministry of Economy, Innovation and Competition, Instituto de Salud Carlos III’ (PI19/01404, PI16/01842, PI17/00535 and GLD19/00100).Peer reviewe

    Impact of interstitial lung disease on the survival of systemic sclerosis with pulmonary arterial hypertension

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    To assess severity markers and outcomes of patients with systemic sclerosis (SSc) with or without pulmonary arterial hypertension (PAH-SSc/non-PAH-SSc), and the impact of interstitial lung disease (ILD) on PAH-SSc. Non-PAH-SSc patients from the Spanish SSc registry and PAH-SSc patients from the Spanish PAH registry were included. A total of 364 PAH-SSc and 1589 non-PAH-SSc patients were included. PAH-SSc patients had worse NYHA-functional class (NYHA-FC), worse forced vital capacity (FVC) (81.2 +/- 20.6% vs 93.6 +/- 20.6%, P < 0.001), worse tricuspid annular plane systolic excursion (TAPSE) (17.4 +/- 5.2 mm vs 19.9 +/- 6.7 mm, P < 0.001), higher incidence of pericardial effusion (30% vs 5.2%, P < 0.001) and similar prevalence of ILD (41.8% vs. 44.9%). In individuals with PAH-SSc, ILD was associated with worse hemodynamics and pulmonary function tests (PFT). Up-front combination therapy was used in 59.8% and 61.7% of patients with and without ILD, respectively. Five-year transplant-free survival rate was 41.1% in PAH-SSc patients and 93.9% in non-PAH-SSc patients (P < 0.001). Global survival of PAH-SSc patients was not affected by ILD regardless its severity. The multivariate survival analysis in PAH-SSc patients confirmed age at diagnosis, worse NYHA-FC, increased PVR, reduced DLCO, and lower management with up-front combination therapy as major risk factors. In conclusion, in PAH-SSc cohort risk of death was greatly increased by clinical, PFT, and hemodynamic factors, whereas it was decreased by up-front combination therapy. Concomitant ILD worsened hemodynamics and PFT in PAH-SSc but not survival regardless of FVC impairment

    Impact of interstitial lung disease on the survival of systemic sclerosis with pulmonary arterial hypertension

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    To assess severity markers and outcomes of patients with systemic sclerosis (SSc) with or without pulmonary arterial hypertension (PAH-SSc/non-PAH-SSc), and the impact of interstitial lung disease (ILD) on PAH-SSc. Non-PAH-SSc patients from the Spanish SSc registry and PAH-SSc patients from the Spanish PAH registry were included. A total of 364 PAH-SSc and 1589 non-PAH-SSc patients were included. PAH-SSc patients had worse NYHA-functional class (NYHA-FC), worse forced vital capacity (FVC) (81.2 ± 20.6% vs 93.6 ± 20.6%, P &lt; 0.001), worse tricuspid annular plane systolic excursion (TAPSE) (17.4 ± 5.2 mm vs 19.9 ± 6.7 mm, P &lt; 0.001), higher incidence of pericardial effusion (30% vs 5.2%, P &lt; 0.001) and similar prevalence of ILD (41.8% vs. 44.9%). In individuals with PAH-SSc, ILD was associated with worse hemodynamics and pulmonary function tests (PFT). Up-front combination therapy was used in 59.8% and 61.7% of patients with and without ILD, respectively. Five-year transplant-free survival rate was 41.1% in PAH-SSc patients and 93.9% in non-PAH-SSc patients (P &lt; 0.001). Global survival of PAH-SSc patients was not affected by ILD regardless its severity. The multivariate survival analysis in PAH-SSc patients confirmed age at diagnosis, worse NYHA-FC, increased PVR, reduced DLCO, and lower management with up-front combination therapy as major risk factors. In conclusion, in PAH-SSc cohort risk of death was greatly increased by clinical, PFT, and hemodynamic factors, whereas it was decreased by up-front combination therapy. Concomitant ILD worsened hemodynamics and PFT in PAH-SSc but not survival regardless of FVC impairment

    Industrias audiovisuales: tendencias de producción y consumo

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    La digitalización de la creación cultural y su difusión online ha supuesto la entrada en los mercados de poderosos y novedosos agentes que se han convertido en los líderes no sólo de la industria tecnológica, sino de toda la producción cultural y de la economía. Dicha digitalización de los medios, además de la convergencia de las pantallas y la ruptura de la linealidad vertical y unidireccional de los medios convencionales ha conllevado un profundo cambio de paradigmas que atañe directamente a la creación audiovisual. Este volumen de la serie iniciada en el año 2012 a partir de las investigaciones de los estudiantes de la asignatura Estructura del mercado audiovisual del grado de Comunicación Audiovisual en la Universidad de Málaga nos lleva al análisis de la recepción y del consumo de diversas industrias del audiovisual, pero también al análisis de la producción condicionada por el contexto económico y por la demanda, así como a diversas cuestiones relacionadas con el marketing y los modelos de negocio de aquellas industrias. En una disciplina en la que no abundan los trabajos académicos actualizados, los autores y autoras de este volumen ofrecen con sus aportaciones estudios de casos significativos y paradigmáticos del estado de los diversos sectores de las industrias audiovisuales. Presentados aquí a modo de capítulos, estos textos suponen la iniciación en la investigación de estudiantes que combinan su formación académica e investigadora con su formación como profesionales en el área de la Comunicación Audiovisual. Ofrecemos aquí una selección de aquellas investigaciones que destacan por su interés, su capacidad analítica y crítica, su actualidad, su pertinencia y su disciplinada adecuación a una metodología de investigación apropiada para unos estudios que forman parte de las Ciencias Sociales. https://www.eumed.net/libros/1851/index.htm

    Prospective individual patient data meta-analysis of two randomized trials on convalescent plasma for COVID-19 outpatients

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    Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when = 50 years and symptomatic for <= 7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with <= 5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution
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