23 research outputs found

    Quando iniciou o Giro Subtropical do Atl√Ęntico Sul?

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    Orientadora: Renata Hanae NagaiMonografia (gradua√ß√£o) - Universidade Federal do Paran√°, Campus Pontal do Paran√°, Centro de Estudos do Mar, Curso de Gradua√ß√£o em Oceanografia.Inclui refer√™nciasResumo : A fragmenta√ß√£o do supercontinente Pangea, na √Čpoca Jur√°ssico inferior, acompanhou a forma√ß√£o dos Oceanos Atl√Ęntico e √ćndico, a modifica√ß√£o do Oceano Pac√≠fico e a forma√ß√£o e desaparecimento do Mar de T√©tis. Estes eventos tect√īnicos produziram altera√ß√Ķes na distribui√ß√£o continental planet√°ria e nas bacias oce√Ęnicas. A evolu√ß√£o fisiogr√°fica do Oceano Atl√Ęntico teve papel fundamental no estabelecimento da circula√ß√£o oce√Ęnica, favorecendo a forma√ß√£o de massas de √°guas profundas que deram origem √† circula√ß√£o termohalina, mas tamb√©m como barreira f√≠sica para passagem de √°guas. Este trabalho tem como objetivo inferir sobre a idade de estabelecimento do Giro Subtropical do Atl√Ęntico Sul (GSAS). Para isso foi realizada uma revis√£o da literatura, buscando consolidar resultados j√° publicados sobre os principais eventos que levaram ao estabelecimento do GSAS. Os trabalhos foram obtidos por meio de ferramentas de busca online e as principais palavras chave foram "Circula√ß√£o do Atl√Ęntico Sul" e "Abertura do Atl√Ęntico Sul". A tect√īnica de placas foi o principal motor da forma√ß√£o do GSAS. A abertura da Passagem de Drake possibilitou a forma√ß√£o da Corrente Circumpolar Ant√°rtica e uma eleva√ß√£o do gradiente de temperatura entre Polo e Equador, as subsid√™ncias nos mares n√≥rdicos deram origem √† √Āgua Profunda do Atl√Ęntico Norte, a forma√ß√£o do Istmo do Panam√° e o fechamento do Mar de T√©tis e permitiram um fortalecimento da circula√ß√£o termohalina assim como a ocorr√™ncia do vazamento das Agulhas, a subsid√™ncia das cordilheiras de Walvis e Rio Grande possibilitaram o tr√Ęnsito das √°guas de fundo com a forma√ß√£o da Corrente e da ressurg√™ncia de Benguela. Esses eventos descritos ocorreram em sua maioria durante a √Čpoca Mioceno (23 ‚Äď 5,3 Ma) e a idade mais prov√°vel para a forma√ß√£o do GSAS, nos moldes atuais, √© de aproximadamente 10 Ma

    Tracking Knowledge Propagation Across Wikipedia Languages

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    In this paper, we present a dataset of inter-language knowledge propagation in Wikipedia. Covering the entire 309 language editions and 33M articles, the dataset aims to track the full propagation history of Wikipedia concepts, and allow follow-up research on building predictive models of them. For this purpose, we align all the Wikipedia articles in a language-agnostic manner according to the concept they cover, which results in 13M propagation instances. To the best of our knowledge, this dataset is the first to explore the full inter-language propagation at a large scale. Together with the dataset, a holistic overview of the propagation and key insights about the underlying structural factors are provided to aid future research. For example, we find that although long cascades are unusual, the propagation tends to continue further once it reaches more than four language editions. We also find that the size of language editions is associated with the speed of propagation. We believe the dataset not only contributes to the prior literature on Wikipedia growth but also enables new use cases such as edit recommendation for addressing knowledge gaps, detection of disinformation, and cultural relationship analysis

    SIGNIFICADOS ATRIBUIDOS POR EL HOMBRE A LA RELACI√ďN ENTRE TABAQUISMO Y PADECIMIENTO DE C√ĀNCER

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    Objective: To understand the meanings assigned by men to the habit of smoking and its risksrelated to the development of cancer.Method: Qualitative study conducted in a specialized health care institute in Rio de Janeiro,Brazil. Eighteen men, both smokers and former smokers, were interviewed from November2015 to April 2016. The data was analyzed using thematic content analysis.Results: Lack of knowledge about the habit of smoking and the feeling of pleasure that itprovides were found to be related to a higher probability of starting the habit. The meaningattributed by men to the relationship between smoking and the health-disease process wasrelated to family history or their own vulnerability. However, a number of men did not feelprepared to quit smoking due to their physical and psycho-emotional dependence.Conclusion: Smoking cessation may require professional support. It is necessary to recognizethe habit of smoking as a health problem, to want to quit smoking, and to identify personalmotivational factors.Objetivo: conhecer os significados que o homem atribui acerca do tabagismo e seus riscos relacionados ao desenvolvimento do c√Ęncer.M√©todo: estudo qualitativo, realizado em um instituto especializado na aten√ß√£o √† sa√ļde, no Rio de Janeiro, Brasil. Foram entrevistados 18 homens fumantes e ex-fumantes entre novembro de 2015 e abril de 2016. Utilizou-se a an√°lise de conte√ļdo na modalidade tem√°tica.Resultados: a falta de conhecimento acerca do tabagismo e a sensa√ß√£o de prazer proporcionada relacionaram-se √† maior probabilidade de se iniciar o h√°bito. O significado atribu√≠do pelos homens sobre a rela√ß√£o com o processo sa√ļde-doen√ßa relacionou-se ao hist√≥rico familiar ou √† vulnerabilidade pr√≥pria. Mas muitos homens n√£o se sentem preparados para parar de fumar, pela depend√™ncia f√≠sica e psicoemocional.Conclus√£o: a cessa√ß√£o do v√≠cio pode requerer ajuda profissional. √Č preciso reconhecer o tabagismo como problema de sa√ļde, desejar parar de fumar e identificar o pr√≥prio fator motivacional.Objetivo: Conocer los significados atribuidos por el hombre respecto del tabaquismo y elriesgo de padecer c√°ncer.M√©todo: estudio cualitativo, realizado en instituto especializado en atenci√≥n de salud de Riode Janeiro, Brasil. Fueron entrevistados 18 hombres fumadores y exfumadores entre noviembrede 2015 y abril de 2016. Se aplic√≥ an√°lisis de contenido de tipo tem√°tico.Resultados: La falta de conocimiento sobre el tabaquismo y la sensaci√≥n de placer proporcionadase relacionaron con una mayor probabilidad de iniciarse en el h√°bito. El significadoatribuido por los hombres a la relaci√≥n con el proceso salud-enfermedad se vincul√≥ a la historiafamiliar o a la propia vulnerabilidad. Pero muchos hombres no se sienten preparados paradejar de fumar, por la dependencia f√≠sica y psicoemocional.Conclusi√≥n: La cesaci√≥n tab√°quica puede precisar de ayuda profesional. Es necesario reconoceral tabaquismo como problema de salud, desear dejar de fumar e identificar al propiofactor motivacional

    Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

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    Funding: Data collection was largely funded by the UK Natural Environment Research Council (NERC) project TREMOR (NE/N004655/1) to D.G., E.G. and O.P., with further funds from Coordena√ß√£o de Aperfei√ßoamento de Pessoal de N√≠vel Superior‚ÄĒBrasil (CAPES, finance code 001) to J.V.T. and a University of Leeds Climate Research Bursary Fund to J.V.T. D.G., E.G. and O.P. acknowledge further support from a NERC-funded consortium award (ARBOLES, NE/S011811/1). This paper is an outcome of J.V.T.‚Äôs doctoral thesis, which was sponsored by CAPES (GDE 99999.001293/2015-00). J.V.T. was previously supported by the NERC-funded ARBOLES project (NE/S011811/1) and is supported at present by the Swedish Research Council Vetenskapsr√•det (grant no. 2019-03758 to R.M.). E.G., O.P. and D.G. acknowledge support from NERC-funded BIORED grant (NE/N012542/1). O.P. acknowledges support from an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. R.S.O. was supported by a CNPq productivity scholarship, the S√£o Paulo Research Foundation (FAPESP-Microsoft 11/52072-0) and the US Department of Energy, project GoAmazon (FAPESP 2013/50531-2). M.M. acknowledges support from MINECO FUN2FUN (CGL2013-46808-R) and DRESS (CGL2017-89149-C2-1-R). C.S.-M., F.B.V. and P.R.L.B. were financed by Coordena√ß√£o de Aperfei√ßoamento de Pessoal de N√≠vel Superior‚ÄĒBrasil (CAPES, finance code 001). C.S.-M. received a scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq 140353/2017-8) and CAPES (science without borders 88881.135316/2016-01). Y.M. acknowledges the Gordon and Betty Moore Foundation and ERC Advanced Investigator Grant (GEM-TRAITS, 321131) for supporting the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk), within which some of the field sites (KEN, TAM and ALP) are nested. The authors thank Brazil‚ÄďUSA Collaborative Research GoAmazon DOE-FAPESP-FAPEAM (FAPESP 2013/50533-5 to L.A.) and National Science Foundation (award DEB-1753973 to L. Alves). They thank Serrapilheira Serra-1709-18983 (to M.H.) and CNPq-PELD/POPA-441443/2016-8 (to L.G.) (P.I. Albertina Lima). They thank all the colleagues and grants mentioned elsewhere [8,36] that established, identified and measured the Amazon forest plots in the RAINFOR network analysed here. The authors particularly thank J. Lyod, S. Almeida, F. Brown, B. Vicenti, N. Silva and L. Alves. This work is an outcome approved Research Project no. 19 from ForestPlots.net, a collaborative initiative developed at the University of Leeds that unites researchers and the monitoring of their permanent plots from the world‚Äôs tropical forests [61]. The authros thank A. Levesley, K. Melga√ßo Ladvocat and G. Pickavance for ForestPlots.net management. They thank Y. Wang and J. Baker, respectively, for their help with the map and with the climatic data. The authors acknowledge the invaluable help of M. Brum for kindly providing the comparison of vulnerability curves based on PAD and on PLC shown in this manuscript. They thank J. Martinez-Vilalta for his comments on an early version of this manuscript. The authors also thank V. Hilares and the Asociaci√≥n para la Investigaci√≥n y Desarrollo Integral (AIDER, Puerto Maldonado, Peru); V. Salda√Īa and Instituto de Investigaciones de la Amazon√≠a Peruana (IIAP) for local field campaign support in Peru; E. Chavez and Noel Kempff Natural History Museum for local field campaign support in Bolivia; ICMBio, INPA/NAPPA/LBA COOMFLONA (Cooperativa mista da Flona Tapaj√≥s) and T. I. Bragan√ßa-Marituba for the research support.Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, ő®50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters ő®50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both ő®50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.Publisher PDFPeer reviewe

    URLGEN ‚Äď Towards Automatic URL Generation Using GANs

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    URLs play an essential role on the Internet, allowing access to Web resources. Automatically generating URLs is helpful in various tasks, such as application debugging, API testing, and blocklist creation for security applications. Current testing suites deeply embed experts’ domain knowledge to generate suitable URLs, resulting in an ad-hoc solution for each given application. These tools thus require heavy manual intervention, with the expensive coding of rules that are hard to maintain. We here introduce URLGEN, a system that uses Generative Adversarial Networks (GANs) to tackle the automatic URL generation problem. URLGEN is designed for web API testing and generates URL samples for an application without any system expertise, complementing the existing tools. It leverages Long Short-Term Memory (LSTM) and Convolutional Neural Network (CNN) architectures, augmented by an embedding layer that simplifies the URL learning and generation process. We show that URLGEN learns to generate new valid URLs from samples of real URLs without requiring any domain knowledge and following a purely data-driven approach. We compare the GAN architecture of URLGEN against other design options and show that the LSTM architecture can better capture the correlation among URL characters, outperforming previously proposed solutions. Finally, we show that the URLGEN approach can be extended to other scenarios, which we illustrate with two use cases, i.e., cybersquatting domain prediction and URL classification
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