10 research outputs found

    Sedimentary provenance of the Marilia Formation (Bauru Basin), Southeast Brazil

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe Marilia Formation is a lithostratigraphic unit positioned at the top of the Bauru Group of Maastrichtian age. The present work presents a provenance study of the Marilia Formation sandstones through the combined dating of the fission-track method (FTM) and U-Pb, in which individual zircon grains are simultaneously dated by these two methods. Thirty-one zircons were dated in the C5 sample and 26 in the C7 sample for a total of 57 grains. The data demonstrated a wide range of U-Pb ages, presenting maximum and minimum ages, respectively: 2,905 +/- 11 and 128 +/- 1 Ma for the C7 sample and 2,676 +/- 10 and 455 +/- 5 Ma for the C5 sample. Regarding the fission-track (FT) ages, they have been grouped into three time intervals, which are associated to geological events relatively well recognized in the published literature: ages younger than 250 Ma (Wealdenian Reactivation); between 250 and 470 Ma (Palaeozoic orogenesis-Ocloyic, Precordilleran, Chanic, and Sanrafaelic); and older than 470 (Precambrian collisions-Brasiliano I, II, and III). There is a predominance of results of Precambrian age using the U-Pb dating, mainly in the Neopalaeoproterozoic, and with FT dating corresponding to the Ocloyic, Precordilleran, Chanic, and Sanrafaelic orogeneses. From the comparison of the results between the two dating methods, the age variations suggest that the zircons originated during the main south-western orogenesis of Gondwana and were reworked during the Palaeozoic and Mesozoic geological episodes. The ages associated to the Upper Cretaceous are related to the tectonic and magmatic activity of the Alto Paranaiba Uplift.117FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2015/17632-

    Diminishing benefits of urban living for children and adolescents’ growth and development

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    Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified

    Diminishing benefits of urban living for children and adolescents' growth and development

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    Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128.9 million children, adolescents, and adults

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