Ore-waste and ore type classification using portable XRF: a case study of an iron mine from the Quadrilátero Ferrífero, Brazil

Grade control is a fundamental activity for Short-Term Mine Planning as it validates the ore-waste and ore type classification of mine faces. Geological mapping and quasi-mining sampling provide indispensable information for the Short-Term Mine Planning team to update block models and for grade control of the run-of-mine (ROM). However, laboratory turnaround can take too long and not be timely for operational needs, affecting mining efficiency. To propose a solution for this issue we tested the accuracy of portable X-Ray Fluorescence (XRF) for ore-waste and ore type classification according to iron and phosphorus grade. Thus, iron ore run-of-mine samples from the Quadrilátero Ferrífero were analyzed with the portable XRF as pressed pellets. As a result, the overall accuracy of ore-waste classification was above 92% for different cut-off grades. On the other hand, while ore type classification had a better accuracy without calibration factors for iron, the use of calibration factors significantly improved the accuracy of ore type classification for phosphorus. Therefore, despite the portable XRF presenting good accuracy for ore-waste and ore type classification, further developments are still necessary on automatic information processing systems and sample support validation so that this analytical tool can be used on a large scale by grade control teams. Finally, the combined use of portable XRF and other techniques, such as Hyperspectral Sensing or XRD, can be of great value for mine operations.O controle de qualidade é uma atividade fundamental para o Planejamento de Lavra de Curto Prazo, pois valida a classificação de minério-estéril e tipo de minério nas frentes de lavra. O mapeamento geológico e a amostragem de grande volume fornecem informações indispensáveis para a equipe de Planejamento de Mina de Curto Prazo atualizar os modelos de blocos e fazer o controle de qualidade do run-of-mine. No entanto, a resposta do laboratório pode levar muito tempo e não ser oportuna para as necessidades operacionais, afetando a eficiência da mineração. Para propor uma solução para esse problema, testamos a acurácia da espectrometria por Fluorescência de Raios X (FRX) portátil para classificação de minério-estéril e tipos de minério de acordo com o teor de ferro e fósforo. Assim, amostras de minério de ferro do Quadrilátero Ferrífero foram analisadas pela FRX portátil como pastilhas prensadas. Como resultado, a acurácia geral da classificação de minério-estéril foi superior a 92% para diferentes teores de corte. Por outro lado, enquanto a classificação dos diferentes tipos de minério teve uma melhor acurácia sem fatores de calibração para o ferro, o uso destes fatores melhorou significativamente a acurácia da classificação do tipo de minério em relação ao fósforo. Portanto, apesar da FRX portátil apresentar boa acurácia para o controle de qualidade, ainda são necessários mais avanços em relação a sistemas automatizados de processamento de informações e validação do suporte amostral para que esta ferramenta possa ser usada em larga escala pelas equipes de controle de qualidade. Finalmente, o uso combinado da FRX portátil e outras técnicas, como análise por Imagens Hiperespectrais ou Difratometria de Raios-X (DRX), pode ser de

SCREENING ELDERLY PATIENTS FOR COGNITIVE FUNCTION AT A REFERENCE CENTER IN NORTHEAST BRAZIL

Introduction: Both demographic and epidemiologic transitions experienced by the country in the past decades bring a number of crucial issues for the health care system, especially in the context of severe social inequality, poverty and fragility of institutions. Objectives: To identify the cognitive profile of non-institutionalized elderly outpatients seen at a reference center in São Luís, Brazil. Methods: Cross-sectional study conducted in a reference center in São Luís, MA, Brazil. Final sample consisted of 102 individuals. Inclusion criteria were: age equal to or over 60 years at first consultation, and ability to understand and to answer the tests for cognitive assessment. This study utilized 3 validated tests that have been widely used in Brazil, including the Mini-Mental State Examination (MMSE), the Verbal Fluency Test (VFT) and the Clock Drawing Test (CDT). Results: A total of 102 individuals were included. The majority of patients were women (72%), aged 60-64 years (33.3%), married or living in consensual union (43.1%), and had non-white skin color (52.9%). The prevalence of cognitive impairment was 60.7% for the Minimental state examination, 23.5% for the Verbal Fluency Test and 59.8 % for the Clock Drawing Test. Regarding the presence of cognitive impairment in at least one test, a total of 83.3% was observed. There was an association between the occurrence of cognitive impairment with both marital status and self-perception of health status (p < 0.05). Conclusions: Hence, in the present study, the occurrence of cognitive impairment was considered high and might be associated with marital and health status.Keywords: Health of the Elderly. Aging. Cognition

Leprosy in children under 15 years of age in a municipality in northeastern Brazil : evolutionary aspects from 2003 to 2015

INTRODUCTION: The Integrated Program of Leprosy Control was initiated in 2003 in the municipality of Buriticupu, Maranhão, Brazil, an area considered hyperendemic for leprosy. Here, we present the evolution of the indicators of leprosy within the established period in children aged <15 years. METHODS: This is a descriptive study based on an active search for cases and spontaneous healthcare demand for leprosy, with an evolutionary analysis of the detection coefficient of new cases. We considered individuals aged <15 years diagnosed with leprosy from January 2003 to December 2015. To evaluate the factors associated with clinical and operational forms, Chi-square, Fisher’s exact, or Fisher-Freeman-Halton tests were performed. RESULTS: A total of 61 new cases were detected (6.9% of the total leprosy cases diagnosed in the municipality during the study period), and the majority was found in males (62.3%). The most frequent operational classification was paucibacillary (67.2%), and this association increased with age. The tuberculoid clinical form was the most prevalent in both sexes and in the age range of 10 to <15 years. There was a reduction in the detection coefficient from 21.84/100,000 inhabitants in 2003 to 2.79/100,000 in 2015. CONCLUSIONS: Despite the progress in the control of leprosy, this historical series shows that it is necessary to strengthen educational measures and implement control actions, so that the disease ceases to be a public health problem in the population aged <15 years

Pervasive gaps in Amazonian ecological research

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

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Pervasive gaps in Amazonian ecological research

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

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

Implicações das propriedades mineralógicas e microestruturais do minério de ferro no processo industrial de pelotização.

Programa de Pós-Graduação em Evolução Crustal e Recursos Naturais. Departamento de Geologia. Escola de Minas, Universidade Federal de Ouro Preto.O presente trabalho compreende os resultados de estudos específicos desenvolvidos sobre as implicações mineralógicas e microestruturais de minério de ferro nos processos unitários de cominuição, filtragem e queima em forno, como fatores de avaliação e controle da qualidade final do produto de pelotização, tendo em vista a otimização da sua produção industrial. Foram caracterizadas amostras das minas de Itabira, Brucutu, Alegria e Fábrica Nova, todas localizadas no Quadrilátero Ferrífero, as quais, são utilizadas no complexo pelotizador de Tubarão localizado em Vitória, no Espírito Santo. As amostras referem-se a diferentes produtos de flotação, de separação magnética e de peneiramento a seco. Características físicas como distribuição granulométrica, densidade, área de superfície específica, além de características mineralógicas como fases minerais, morfologia tridimensional de grão e microestruturas foram determinadas. As características físicas foram determinadas conforme procedimentos utilizados no complexo pelotizador de Tubarão e as características mineralógicas foram determinadas a partir de estereoscópio, microscópio óptico e microscópio eletrônico com o módulo electron backscater difraction. As relações entre as características mineralógicas e os resultados dos testes de moagem permitiram definir os tipos de produto e propor uma relação entre o índice de moabilidade e os tipos morfológicos caracterizados. Posteriormente, foi planejada e implementada uma matriz de experimento a partir de misturas dos produtos para testes nos processos estudados. Também foi caracterizada a mistura desses concentrados que alimentam a pelotização. Em ambos os processos unitários estudados, os testes aconteceram em escala de bancada e piloto. Nos testes de moagem e filtragem as variações mineralógicas causaram impacto, respectivamente, no índice de moabilidade e na umidade da torta retida. Os resultados dos testes de filtragem indicam uma relação entre os valores de umidade e produtividade com os valores de hematita martítica. Já para o teste de compressão das pelotas queimadas, a estatística dos resultados indicaram diferença de compressão entre misturas com diferentes quantidades de goethita.This work includes the results of specific studies on the mineralogical and microstructural implications of iron ore in the processes of comminution, filtering and induration process oven as evaluation factors, and control the quality of the final pellet product, with a view to optimizing industrial process. Iron ore samples of the mine Itabira, Brucutu, Alegria e Fábrica Nova were characterized. The samples are different products of flotation, magnetic separation and screening. Grain size distribution, density, specific surface area, mineral phase, morphology and microstructure were determined. The physical characteristics were determined according to industrial procedures of the Tubarão pelletinzing plant in Vitória, Espírito Santo. The mineralogical characteristics were determined with stereoscope, optical microscope and electron backscatter diffraction. The relationship between mineralogy and grinding test were then established after the iron ore characterization. Afterwards, we carried out an experiment using blends of the iron ore plant products to test in the pelletizing process. The blends that feed the pelletinzing plants were also tested with the same purpose. Both tests were accomplished in bench as well as in pilot scale. It was also characterized blends these concentrates that feed pelletinzing. The grinding and filtration tests showed that the mineralogical types exert a strong influence on the grinding index and moisture of the filter cake. A direct relationship arouse from the grinding process in which the morphological types are closely related to the grinding index. Likewise the results of the filtration tests pointed up that the martitic types affect considerably the moisture and therefore the performance of the filtration process. Finally, the compress tests of the fired pellets demonstrate that the proportion of goethite phases in the iron ores affects the cold compression strength results of the pellets