43 research outputs found

    The miniJPAS survey : photometric redshift catalogue

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    MiniJPAS is a ∌1 deg2 imaging survey of the AEGIS field in 60 bands, performed to demonstrate the scientific potential of the upcoming Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS). Full coverage of the 3800–9100 Å range with 54 narrow-band filters, in combination with 6 optical broad-band filters, allows for extremely accurate photometric redshifts (photo-z), which, applied over areas of thousands of square degrees, will enable new applications of the photo-z technique, such as measurement of baryonic acoustic oscillations. In this paper we describe the method we used to obtain the photo-z that is included in the publicly available miniJPAS catalogue, and characterise the photo-z performance. We built photo-spectra with 100 Å resolution based on forced-aperture photometry corrected for point spread function. Systematic offsets in the photometry were corrected by applying magnitude shifts obtained through iterative fitting with stellar population synthesis models. We computed photo-z with a customised version of LePhare, using a set of templates that is optimised for the J-PAS filter-set. We analysed the accuracy of miniJPAS photo-z and their dependence on multiple quantities using a subsample of 5266 galaxies with spectroscopic redshifts from SDSS and DEEP, which we find to be representative of the whole r 0.03), regardless of the magnitude, redshift, or spectral type of the sources. We show that the two main summary statistics characterising the photo-z accuracy for a population of galaxies (σNMAD and η) can be predicted by the distribution of odds in this population, and we use this to estimate the statistics for the whole miniJPAS sample. At r 0.82 with η = 0.05, at the cost of decreasing the density of selected galaxies to n ∌ 5200 deg−2 (∌2600 of which have |∆z| < 0.003)

    The miniJPAS survey : A search for extreme emission-line galaxies

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    Context. Galaxies with extreme emission lines (EELGs) may play a key role in the evolution of the Universe, as well as in our understanding of the star formation process itself. For this reason an accurate determination of their spatial density and fundamental properties in different epochs of the Universe will constitute a unique perspective towards a comprehensive picture of the interplay between star formation and mass assembly in galaxies. In addition to this, EELGs are also interesting in order to explain the reionization of the Universe, since their interstellar medium (ISM) could be leaking ionizing photons, and thus they could be low z, analogous of extreme galaxies at high z. Aims. This paper presents a method to obtain a census of EELGs over a large area of the sky by detecting galaxies with rest-frame equivalent widths ≄300 Å in the emission lines [Oii]λλ3727,3729Å, [Oiii]λ5007Å, and Hα. For this, we aim to use the J-PAS survey, which will image an area of ≈8000 deg2 with 56 narrow band filters in the optical. As a pilot study, we present a methodology designed to select EELGs on the miniJPAS images, which use the same filter dataset as J-PAS, and thus will be exportable to this larger survey. Methods. We make use of the miniJPAS survey data, conceived as a proof of concept of J-PAS, and covering an area of ≈1 deg2 . Objects were detected in the rSDSS images and selected by imposing a condition on the flux in a given narrow-band J-PAS filter with respect to the contiguous ones, which is analogous to requiring an observed equivalent width larger than 300 Å in a certain emission line within the filter bandwidth. The selected sources were then classified as galaxies or quasi-stellar objects (QSOs) after a comparison of their miniJPAS fluxes with those of a spectral database of objects known to present strong emission lines. This comparison also provided a redshift for each source, which turned out to be consistent with the spectros This comparison also provided a redshift for each source, which turned out to be consistent with the spectroscopic redshifts when available (|∆z/(1 + zspec)| ≀ 0.01). Results. The selected candidates were found to show a compact appearance in the optical images, some of them even being classified as point-like sources according to their stellarity index. After discarding sources classified as QSOs, a total of 17 sources turned out to exhibit EW0 ≄ 300 Å in at least one emission line, thus constituting our final list of EELGs. Our counts are fairly consistent with those of other samples of EELGs in the literature, although there are some differences, which were expected due to biases resulting from different selection criteria

    Population-based seroprevalence of SARS-CoV-2 and the herd immunity threshold in MaranhĂŁo

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    OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of MaranhĂŁo, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated ElecsysÂź Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the CobasÂź e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon.OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of MaranhĂŁo, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated ElecsysÂź Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the CobasÂź e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon

    Abordagem multimodal para prevenção e manejo clĂ­nico e cirĂșrgico da Ășlcera pĂ©ptica

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    A Ășlcera pĂ©ptica (UP) Ă© definida como lesĂŁo no trato gastrointestinal, devido ao excesso de acidez ou de infecção por Helicobacter pylori (H. pylori). Quanto Ă  epidemiologia, a UP possui maior prevalĂȘncia em idosos de 65 anos ou mais e em pessoas com comorbidades que causam um maior consumo de medicaçÔes como anti-inflamatĂłrios nĂŁo esteroides (AINES), aspirina e anticoagulantes. Quanto Ă s manifestaçÔes clĂ­nicas, a doença apresenta epigastralgia como principal sintoma, mas tambĂ©m pode estar associada Ă  plenitude pĂłs-prandial ou saciedade precoce, nĂĄuseas e vĂŽmitos, perda ponderal e dor abdominal logo em perĂ­odo pĂłs-prandial, podendo alguns serem assintomĂĄticos. Sua identificação depende de uma anamnese minuciosa, um exame fĂ­sico bem detalhado e exames complementares. No que tange ao diagnĂłstico clĂ­nico, dor abdominal, melena, taquicardia e sinais de perda sanguĂ­nea, sĂŁo essenciais para identificação da patologia. Para diagnĂłstico definitivo, lança-se mĂŁo da endoscopia digestiva alta, biĂłpsia com exame histopatolĂłgico, imuno-histoquĂ­mica, teste de urease, ensaio de cultura e reação em cadeia da polimerase (PCR), fornecendo mais detalhes com melhor acurĂĄcia para, juntamente com os dados clĂ­nicos, obter o diagnĂłstico. JĂĄ a abordagem terapĂȘutica, apresenta-se atravĂ©s do manejo farmacolĂłgico e cirĂșrgico. Na abordagem farmacolĂłgica, lança-se mĂŁo de inibidor de bomba de prĂłtons (IBP), claritromicina e amoxicilina. A abordagem cirĂșrgica utiliza a vagotomia troncular, antrectomia e tĂ©cnicas cirĂșrgicas como Bilroth I, Bilroth II e Y de Roux para a reconstrução do trĂąnsito intestinal. Em relação a prevenção, medicamentos gastroprotetores podem ajudar a reduzir a carga global da Ășlcera pĂ©ptica e suas complicaçÔes

    Os desafios do atendimento de pacientes com sequelas cardiovasculares decorrentes de trauma do tĂłrax / Challenges in the care of patients with cardiovascular sequels resulting from chest trauma

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    Introdução: O tĂłrax apresenta estruturas de diversos sistemas de sustentação da vida, dentre eles o respiratĂłrio e o cardiovascular. Por conter, estruturas nobres para a manutenção da vida, os potenciais para ocorrer lesĂ”es graves em decorrĂȘncia de traumas sĂŁo muito grandes, como dados mostram, 25% das mortes sĂŁo secundĂĄrias a trauma torĂĄcico. Dentro deste contexto, questiona-se quais os desafios no atendimento de pacientes com sequelas cardiovasculares decorrentes de traumas torĂĄcicos? Portanto, esse estudo tem como objetivo identificar as dificuldades enfrentadas na assistĂȘncia de saĂșde de pacientes com repercussĂ”es cardiovasculares devido a trauma de tĂłrax, atravĂ©s da elaboração de um formulĂĄrio baseado em revisĂŁo bibliogrĂĄfica de dados da literatura cientĂ­fica publicados sobre esse tema. Metodologia: O trabalho baseia-se numa revisĂŁo integrativa de literatura, na qual foram analisados artigos publicados em revistas cientĂ­ficas, utilizando-se das bases de dados da BVS (Biblioteca Virtual da SaĂșde), como: Lilacs (Literatura Latino-Americana e do Caribe em CiĂȘncias da SaĂșde) e Scielo (Scientific Electronic Library Online). Resultados: ApĂłs as anĂĄlises e seleção, restaram-se sete artigos para integrar a discussĂŁo. Os artigos selecionados, estĂŁo descritos na tabela, com autores, tĂ­tulo, metodologia, resultados e conclusĂŁo. Em seguida, foi realizada uma discussĂŁo acerca destes artigos. ConclusĂŁo: Cada um dos casos revisados neste estudo demonstra a necessidade e a importĂąncia de acompanhamento cuidadoso de todos os pacientes que sofreram trauma torĂĄcico fechado, mesmo que a avaliação cardĂ­aca inicial possa ser negativa.

    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 un derstanding 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,5–7 vast areas of the tropics remain understudied.8–11 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 underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities 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 or ganism 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 ne glected 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 lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Cidadania por um fio: o associativismo negro no Rio de Janeiro (1888-1930)

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    Pervasive gaps in Amazonian ecological research

    Get PDF
    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

    Pervasive gaps in Amazonian ecological research

    Get PDF
    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
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