94 research outputs found
The insecurity of Vale’s dams in Minas Gerais, Brazil: applying activity theory to disaster analysis
The objective of this article is to point out hypotheses of contradictions historically incubated in Vale’s activity systems and that may have led to Brazil’s biggest environmental disaster, the B I dam break in Brumadinho, and the interdiction of many other dams owned by Vale in the state of Minas Gerais, Brazil. This is a case analysis from secondary data available in interviews, documents, and texts published in different media between 2011 and 2021. We try to demonstrate, from the Historical-Cultural Theory of Activity, the contradictions verified in and between Vale’s activity systems, since the company distributed large dividends to its shareholders, remunerated its directors as never before, reduced costs in relation to incomes, and brutally reduced internal debt, but keeping insufficient investments in dam management, culminating with the break of B I in 2019 and with 29 dams interdicted in March 2021. Financialization has become central to the company’s operations. This study points to a methodological path of the interdisciplinary dialogue to help clarify how strategic managerial decisions, especially those of financial management, could influence the production, maintenance, and safety management of tailings dams.O objetivo deste artigo é apontar hipóteses de contradições que estariam incubadas historicamente nos sistemas de atividades da Vale, e que podem ter levado ao maior desastre ambiental do Brasil: o rompimento da barragem B I em Brumadinho, bem como à interdição de muitas outras barragens da empresa no estado de Minas Gerais, Brasil. Trata-se de uma análise de caso a partir de dados secundários disponíveis em entrevistas, documentos e textos publicados em diferentes mídias entre 2011 e 2021. Procuramos demonstrar, a partir da Teoria Histórico-Cultural da Atividade, as contradições verificadas em e entre sistemas de atividades da Vale, pois a empresa distribuiu dividendos vultosos aos seus acionistas, remunerou como nunca seus diretores, reduziu os custos em relação às receitas e diminuiu brutalmente a dívida interna, mas manteve investimentos insuficientes na gestão das barragens, culminando no rompimento da B I em 2019 e em 29 barragens interditadas em março de 2021. A financeirização tornou-se central para as operações da empresa. Este estudo aponta para um caminho metodológico do diálogo interdisciplinar que ajuda a esclarecer como as decisões gerenciais estratégicas, especialmente aquelas da gestão financeira, poderiam influenciar a gestão de produção, de manutenção e de segurança das barragens de rejeitos
Characterization of indicator tree species in neotropical environments and implications for geological mapping
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOGeobotanical remote sensing (GbRS) in the strict sense is an indirect approach to obtain geological information in heavily vegetated areas for mineral prospecting and geological mapping. Using ultra- and hyperspectral technologies, the goals of this resea216385400FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2010/51758-2, 2010/51718-0309712/2017-3, 302925/2015-
Avaliação de Abrigos Alternativos para Termo Higrômetros em Função do Custo, Manuseio e Análise Estatística do Desempenho
The standardization of data collection instruments is critical to the quality of the microclimate studies. Due to financial constraints and specific needs many sensors, shelters and alternative systems the standards are developed, based on experience and creativity of researchers. The objective of this study is to provide subsidy to the urban climate studies, checking the influence of different types of alternative shelters thermo-hygrometers at fixed points, and were built five types of shelters and evaluated for performance, ease of implementation, materials and tools used, and the costs involved. Based on the performance of alternative shelters analyzed, it has the shelter of the vertical type and the ice cream pot does not demonstrate efficient to collect data at fixed points, especially if used during the day. It can also conclude that not only material used is linked to the performance, but also on its architecture.A padronização dos instrumentos de coleta de dados é fundamental para a qualidade dos estudos microclimáticos. Devido a limitações financeira e necessidades especificas muitos sensores, abrigos e sistemas alternativos aos padrões são desenvolvidos, baseados na experiência e criatividade dos pesquisadores. O objetivo deste trabalho é fornecer subsídio aos estudos de clima urbano, verificando as influências de diferentes tipos de abrigos alternativos para termo-higrômetros em pontos fixos, sendo que foram construídos cinco tipos de abrigos e avaliados quanto ao desempenho, a facilidade de execução, os matérias e ferramentas utilizados, e os custos envolvidos. Com base no desempenho dos abrigos alternativos analisados, tem-se que os abrigos do tipo vertical e o com pote de sorvete não se demonstram eficientes para a coleta de dados em pontos fixos, principalmente se utilizados durante o dia. É possível também concluir que não apenas o material utilizado está associado ao desempenho, mas também quanto à sua arquitetura
Production of Hydrogen and their Use in Proton Exchange Membrane Fuel Cells
This work will show an overview of the hydrogen production from ethanol by steam reforming method, using distinct catalysts, resulting in low carbon monoxide content in H2 produced; a thermodynamic analysis of reforming employing entropy maximization, the ideal condition for ethanol, and other steam reforming reactions, the state of the art of steam reforming catalysts for H2 production with low CO content. Moreover, in the second part, there will be an overview of the use of hydrogen in a proton exchange membrane fuel cell (PEMFC), the fuel cell operational conditions, a thermodynamic analysis of PEMFC, the catalysts used in the electrodes of the fuel cell, consequences of the CO presence in the hydrogen fuel feed in PEMFC, and the operation conditions for maximum output power density
O manejo dos sangramentos uterinos anormais em pacientes em idade reprodutiva: The management of abnormal uterine bleeding in patients of reproductive age
O sangramento uterino anormal refere ao sangramento uterino de quantidade, duração ou cronograma anormal, pode ser causado por patologia estrutural uterina ou causas não uterinas. As definições padrão de sangramento menstrual normal e anormal são devido às anormalidades na frequência, tais como sangramento menstrual frequente refere-se a períodos que começam em intervalos <24 dias, sangramento menstrual infrequente refere-se a períodos que começam em intervalos >38 dias, ausência de menstruação é amenorreia primária (ausência de menarca aos 15 anos) ou secundária (ausência de sangramento menstrual espontâneo por seis meses em uma paciente que teve sangramento menstrual anteriormente). As pacientes com sangramento uterino anormal devem ter história e exame físico completos, informações sobre a frequência, duração e volume do sangramento uterino, bem como a presença de sintomas associados e fatores precipitantes. A gravidez deve ser excluída em todas as pacientes. As pacientes com sangramento menstrual intenso geralmente são submetidas a exames de imagem pélvica para avaliar lesões estruturais, um hemograma completo e medição do nível de ferritina. Os laboratórios adicionais são solicitados se houver suspeita de um distúrbio hemorrágico, como doença de von Willebrand ou endócrino, como hipotireoidismo. A amostragem endometrial é realizada para pacientes com obesidade ou outros fatores de risco para hiperplasia ou carcinoma endometrial. 
Probing conformational changes in orphan nuclear receptor: The NGFI-B intermediate is a partially unfolded dimer
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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