38 research outputs found

    Quantification and source identification of atmospheric particulate polycyclic aromatic hydrocarbons and their dry deposition fluxes at three sites in Salvador Basin, Brazil, impacted by mobile and stationary sources

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    The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Maré Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.O presente trabalho apresenta o estudo sobre 16 HPAs prioritários em material particulado atmosférico de três sítios próximos a Salvador-BA: (i) Estação da Lapa, estação de ônibus da Região Metropolitana de Salvador; (ii) Porto de Aratu, impactado por intenso movimento de matérias-primas e (iii) Bananeira, localizado na Ilha de Maré, vilarejo que tem como principais atividades a pesca e artesanato. Resultados mostraram que o BbF (0,130-6,85 ng m-3) foi o HPA com as concentrações mais elevadas em Aratu e Bananeira e CRY (0,075-6,85 ng m-3) apresentou nível mais elevado na Lapa. As fontes de HPAs nos sítios estudados foram principalmente de origem antrópica, tais como veículos de pequeno e grande portes, carregamentos do porto, ressuspensão de partículas do solo, queima de diesel das embarcações e a queima de carvão e madeira para produção de energia.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FINEPFAPESBPRONEXRECOMBIONordeste GenerationANEELFAPES

    Landsat sub-pixel land cover dynamics in the Brazilian Amazon

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    The Brazilian Amazon land cover changes rapidly due to anthropogenic and climate drivers. Deforestation and forest disturbances associated with logging and fires, combined with extreme droughts, warmer air, and surface temperatures, have led to high tree mortality and harmful net carbon emissions in this region. Regional attempts to characterize land cover dynamics in this region focused on one or two anthropogenic drivers (i.e., deforestation and forest degradation). Land cover studies have also used a limited temporal scale (i.e., 10–15 years), focusing mainly on global and country-scale forest change. In this study, we propose a novel approach to characterize and measure land cover dynamics in the Amazon biome. First, we defined 10 fundamental land cover classes: forest, flooded forest, shrubland, natural grassland, pastureland, cropland, outcrop, bare and impervious, wetland, and water. Second, we mapped the land cover based on the compositional abundance of Landsat sub-pixel information that makes up these land cover classes: green vegetation (GV), non-photosynthetic vegetation, soil, and shade. Third, we processed all Landsat scenes with <50% cloud cover. Then, we applied a step-wise random forest machine learning algorithm and empirical decision rules to classify intra-annual and annual land cover classes between 1985 and 2022. Finally, we estimated the yearly land cover changes in forested and non-forested ecosystems and characterized the major change drivers. In 2022, forest covered 78.6% (331.9 Mha) of the Amazon biome, with 1.4% of secondary regrowth in more than 5 years. Total herbaceous covered 15.6% of the area, with the majority of pastureland (13.5%) and the remaining natural grassland. Water was the third largest land cover class with 2.4%, followed by cropland (1.2%) and shrubland (0.4%), with 89% overall accuracy. Most of the forest changes were driven by pasture and cropland conversion, and there are signs that climate change is the primary driver of the loss of aquatic ecosystems. Existing carbon emission models disregard the types of land cover changes presented in the studies. The twenty first century requires a more encompassing and integrated approach to monitoring anthropogenic and climate changes in the Amazon biome for better mitigation, adaptation, and conservation policies

    The miniJPAS survey quasar selection IV: Classification and redshift estimation with SQUEzE

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    We present a list of quasar candidates including photometric redshift estimates from the miniJPAS Data Release constructed using SQUEzE. This work is based on machine-learning classification of photometric data of quasar candidates using SQUEzE. It has the advantage that its classification procedure can be explained to some extent, making it less of a `black box' when compared with other classifiers. Another key advantage is that using user-defined metrics means the user has more control over the classification. While SQUEzE was designed for spectroscopic data, here we adapt it for multi-band photometric data, i.e. we treat multiple narrow-band filters as very low-resolution spectra. We train our models using specialized mocks from Queiroz et al. (2022). We estimate our redshift precision using the normalized median absolute deviation, σNMAD\sigma_{\rm NMAD} applied to our test sample. Our test sample returns an f1f_1 score (effectively the purity and completeness) of 0.49 for quasars down to magnitude r=24.3r=24.3 with z2.1z\geq2.1 and 0.24 for quasars with z<2.1z<2.1. For high-z quasars, this goes up to 0.9 for r<21.0r<21.0. We present two catalogues of quasar candidates including redshift estimates: 301 from point-like sources and 1049 when also including extended sources. We discuss the impact of including extended sources in our predictions (they are not included in the mocks), as well as the impact of changing the noise model of the mocks. We also give an explanation of SQUEzE reasoning. Our estimates for the redshift precision using the test sample indicate a σNMAD=0.92%\sigma_{NMAD}=0.92\% for the entire sample, reduced to 0.81\% for r<22.5r<22.5 and 0.74\% for r<21.3r<21.3. Spectroscopic follow-up of the candidates is required in order to confirm the validity of our findings.Comment: Accepted in A&A 24 pages, 24 figures, 7 table

    J-PAS: forecasts on dark energy and modified gravity theories

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    The next generation of galaxy surveys will allow us to test one of the most fundamental assumptions of the standard cosmology, i.e. that gravity is governed by the general theory of relativity (GR). In this paper, we investigate the ability of the Javalambre Physics of the AcceleratingUniverseAstrophysical Survey (J-PAS) to constrainGR and its extensions. Based on the J-PAS information on clustering and gravitational lensing, we perform a Fisher matrix forecast on the effective Newton constant, mu, and the gravitational slip parameter, eta, whose deviations from unity would indicate a breakdown of GR. Similar analysis is also performed for the DESI and Euclid surveys and compared to J-PAS with two configurations providing different areas, namely an initial expectation with 4000 deg(2) and the future best case scenario with 8500 deg(2). We show that J-PAS will be able to measure the parameters mu and eta at a sensitivity of 2-7 per cent, and will provide the best constraints in the interval z = 0.3-0.6, thanks to the large number of ELGs detectable in that redshift range. We also discuss the constraining power of J-PAS for dark energy models with a time-dependent equation-of-state parameter of the type w(a) = w(0) + w(a)(1 - a), obtaining Delta w(0) = 0.058 and Delta w(a) = 0.24 for the absolute errors of the dark energy parameters.© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical SocietyWe are thankful to our colleagues of J-PAS Theory Working Group for useful discussions and to Ricardo Landim for his comments. MAR and ALM acknowledge support from MINECO (Spain) project FIS2016-78859-P (AEI/FEDER, UE), Red Consolider MultiDark FPA2017-90566-REDC, and UCM pre-doctoral grant. JSA acknowledges support from FAPERJ grant no. E-26/203.024/2017; CNPq grant no. 310790/2014-0 and 400471/2014-0; and the Financiadora de Estudos e Projetos -FINEP grants REF. 1217/13-01.13.0279.00 and REF0859/10-01.10.0663.00. SC acknowledges support from CNPq grant nos 307467/2017-1 and 420641/2018-1. This paper has gone through internal review by the J-PAS collaboration. Funding for the J-PAS Project has been provided by the Governments of Espana and Aragon through the Fondo de Inversion de Teruel, European FEDER funding, the MINECO projects AYA2015-66211-C2-1- P, AYA2015-66211-C2-2, and AYA2012-30789; the Brazilian agencies FINEP, FAPESP, FAPERJ and by the National Observatory of Brazil.Peer reviewe

    Estudo comparativo da atuação do enfermeiro no controle de dengue e febre chikungunya

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    Resumo O objetivo deste estudo foi analisar a atuação dos enfermeiros das Estratégias de Saúde da Família no controle de dengue e febre chikungunya nos municípios de Parnamirim e Santa Cruz/RN. Trata-se de um estudo exploratório, descritivo, com abordagem qualitativa de tratamento e análise de dados. A coleta foi realizada entre novembro e dezembro de 2015 por meio de uma entrevista gravada, voltada às questões que abordam a ação da enfermagem e sua equipe no controle de dengue e febre chikungunya no campo de atuação da ESF. Utilizou-se como método de observação dos dados a análise de conteúdo de Bardin. Após análise, houve criação de duas categorias - educação em saúde e campanhas pontuais. Na primeira, os entrevistados informaram realizar palestras educativas, mas não explicam a metodologia usada e nem a participação popular, como também a articulação com o setor de endemias da cidade para fortalecer a discussão. Na segunda, algumas ações são assistencialistas de caráter campanhista/higienista, realizadas pelos enfermeiros dos municípios em campanhas de &#8220;higienização&#8221; e &#8220;limpeza&#8221;, as quais se mostram bastante presentes nas falas dos entrevistados. Há uma forte presença desse modelo enraizada tanto nas ações quanto na realização de atividades educativas, usando como metodologia a palestra. Além disso, há necessidade de se realizar mais estudos que aprofundem o tema abordado, a julgar por uma amostra pequena, especialmente no município de Parnamirim

    Bromophenol concentrations in fish from Salvador, BA, Brazil

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    The main objective of this work is to evaluate the occurrence of bromophenols (2bromophenol, 4bromophenol, 2,4dibromophenol, 2,6dibromophenol and 2,4,6tribromophenol), in the flesh and guts in two species of the LutjanidaeFamily: Lutjanus synagris and Ocyurus chrysurus. The bromophenols were extracted by steam distillation with pentaneether (7:3 v/v), identified by reverse phase High Performance Liquid Chromatography (HPLCUV), and quantified bythe externalstandard method. Total bromophenol concentrations were similar in the muscle of both species, rangingfrom 36 ng g¹ to 349 ng g¹. The total bromophenol concentrations in stomach (ranging from 12 ng g¹ to 586 ng g¹)were slightly higher than in muscle. The presence of bromophenol in the muscles of the species under study may occuras a result of their diet. The results of this work are therefore expected to contribute toward a better understanding ofthe path of bromophenol absorption from the fish's stomach to the rest of its body.<br>O principal objetivo do presente trabalho foi o estudo de bromofenóis (2bromofenol, 4bromofenol, 2,4dibromofenol,2,6dibromofenol and 2,4,6tribromofenol), no músculo e estômago de duas espécies de peixes da Familia Lutjanidae: Lutjanus synagris e Ocyurus chrysurus. Os bromofenóis foramextraídos através de destilação por arraste a vapor com pentanoéter (7:3 v/v), analisados por Cromatografia Líquida de AltaEficiência e quantificados por padronização externa. As concentrações totais de bromofenóis no músculo de ambas as espécies foram similares e estiveram na faixa de 36 ng g¹ a349 ng g¹. As concentrações totais de bromofenóis no estômago (na faixa de 12 ng g¹ a 586 ng g¹) foram mais altas queno músculo. A presença de bromofenóis no músculo das espécies estudadas pode ter origem na dieta. Os resultados destetrabalho contribuirão para o melhor entendimento das rotas deabsorção de bromofenóis nos peixes
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