Updating mining reserves with uncertainty data

In mining operations, the time delay between grade estimations and decision about the scheduling of stopes mining can result in seriously outdated information and, consequently, a substantial mined reserves bias. To mitigate this gap between the grade estimation of an orebody and its exploitation, this paper proposes a new method of speedily updating resources and reserves integrated into the concept of real-time mining. This consists in the continuous and swift update of mine reserves, which requires a continuous and fast stream of the measurements of stopes in an underground mine rather than the chemical lab analysis of core samples or chip/face samples. Here we propose using portable for the swift monitoring of ore grades. However, this “fast” data be highly uncertain. For this reason, the first step consists of creating a bidistribution function between “uncertain” XRF and the corresponding “hard” measurements, based on empirical historical data. Following this, the uncertainty of the XRF measurements is derived from those bi-distributions through the conditional distribution of real values given to the known XRF measurement.The second step involves updating the reserves by integrating this uncertain XRF data, which has been quantified by conditional distributions, in the grade characterization models. For this purpose, a stochastic simulation with point distributions is applied. A case study of a sulphide copper deposit illustrates the proposed methodology

Há negros portugueses? Disputa por sentidos à história e cultura em Portugal

This article is the result of a research on the investments by anti-racist movements on the re-education of Portuguese society towards ethnic-racial relations through the production of narrative disputes about history, culture and identity in Portugal. As sources for the analysis, we will mainly use articles and manifestos produced by black militants and published in the Portuguese press between 2016 and 2019 years, moment in which an important discussion in this respect gains force involving the creation of two cultural equipment: the Discoveries Museum and a memorial in honor of enslaved people.Este artículo es el resultado de una investigación sobre las acciones de los movimientos antirracistas a la reeducación de la sociedad portuguesa hacia las relaciones étnico-raciales a través de la producción de disputas narrativas sobre historia, cultura e identidad en Portugal. Como fuentes para el análisis utilizaremos principalmente artículos y manifiestos producidos por militantes negros y publicados en la prensa portuguesa entre 2016 y 2019, momento en el que una discusión importante a este respecto cobra fuerza que implica la creación de dos equipos culturales: el Museo de los Descubrimientos y un memorial en honor a las personas esclavizadas.Este artigo é resultado de uma pesquisa sobre as investidas, por parte de movimentos de luta antirracista, na reeducação da sociedade portuguesa para as relações étnico-raciais, através da produção de disputas narrativas sobre história, cultura e identidade, em Portugal. Como fontes para a análise, utilizaremos principalmente artigos e manifestos produzidos por militantes negros e publicados na imprensa portuguesa entre 2016 e 2019, momento em que ganha força uma importante discussão a esse respeito, envolvendo a criação de dois equipamentos culturais: o Museu das Descobertas e um memorial em homenagem às pessoas escravizadas

Strengthening Bioethics Committees from Portuguese Speaking African Countries

In the last decade, in Lusophone African countries, like in other countries from Africa, health research has increased and in response Research Ethics Committees have been established namely in Universities, Research Centers and Ministries of Health. But these committees still face a serious lack of staff trained in research ethics, and the "language divide" is an important barrier faced by them, as the main ethics educational resources are only available in English. The aim the north-south LusoAfro-Bioethics initiative, financed by EDCTP, is to strength capacity for health research ethics review in African portuguese speaking countries. More specifically, the objectives are: to improve institutional and personnel capacities of Angola, Cape-Verde and Mozambique ethics committees; to enhance the efficiency of clinical/ health research applications reviews; to promote collaborative/ networking activities in research ethics in lusophone countries; to share good practices on Standard Operation Procedures, Protocol Review and international regulatory ethical and legal norms and standards and finally to promote the establishment of University of Cape Verde Institutional Review Board. The actions developed under this initiative aimed to develop robust capacities for ethical review of clinical research in Sub-Saharan African portuguese speaking countries.publishe

Molecular epidemiological investigation of Mayaro virus in febrile patients from Goiania City, 2017-2018.

Mayaro virus (MAYV) has historically been associated with sylvatic transmission; however, urban outbreaks have been reported in Brazil, including cases of co-detection with dengue virus (DENV). Therefore, we performed a molecular survey to investigate MAYV circulation and cocirculation with DENV within Goiania, a major city in Central-West Brazil. Among 375 subjects with arbovirus-like symptoms, 259 were positive for DENV and 26 for MAYV. Of these, 17 were coinfected with DENV-2, suggesting co-transmission of the viruses. The most common complaints at the time of inclusion were myalgia, headache, fever, arthralgia, retro-orbital pain, and skin rash. No specific symptoms were associated with MAYV when either detected alone or co-detected with DENV, compared to that when DENV was detected alone. Most MAYV-infected subjects were women with no recent travel history to rural/sylvatic areas. Phylogenetic reconstruction indicated that the MAYV identified in this study is closely related with a lineage observed in Peru, belonging to genotype D. Our results corroborate the growing circulation of MAYV in urban environments in Brazil and reinforce the need to implement laboratory diagnosis in the Unified Health System, considering that the clinical manifestations of Mayaro fever are similar to those of other arboviruses, particularly dengue. Furthermore, most cases occurred in association with DENV-2. Further phylogenetic studies are needed to evaluate MAYV, which has not been widely examined

A SARS-CoV-2 Negative Antigen Rapid Diagnostic in RT-qPCR Positive Samples Correlates With a Low Likelihood of Infectious Viruses in the Nasopharynx

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) transmission occurs even among fully vaccinated individuals; thus, prompt identification of infected patients is central to control viral circulation. Antigen rapid diagnostic tests (Ag-RDTs) are highly specific, but sensitivity is variable. Discordant RT-qPCR vs. Ag-RDT results are reported, raising the question of whether negative Ag-RDT in positive RT-qPCR samples could imply the absence of infectious viruses. To study the relationship between negative Ag-RDT results with virological, molecular, and serological parameters, we selected a cross-sectional and a follow-up dataset and analyzed virus culture, subgenomic RNA quantification, and sequencing to determine infectious viruses and mutations. We demonstrated that RT-qPCR positive while SARS-CoV-2 Ag-RDT negative discordant results correlate with the absence of infectious virus in nasopharyngeal samples. A decrease in sgRNA detection together with an expected increase in detectable anti-S and anti-N IgGs was also verified in these samples. The data clearly demonstrate that a negative Ag-RDT sample is less likely to harbor infectious SARS-CoV-2 and, consequently, has a lower transmissible potential

Paulo Silva: um contraponto nas relações raciais no Brasil

Este livro faz parte de uma coleção, o projeto coletivo "Personagens do pós-Abolição: trajetórias, e sentidos de liberdade no Brasil republicano", contemplado com o Edital "Memórias Brasileiras: Biografias" (n° 13/2015 da Capes). O quarto volume é dedicado ao maestro Paulo Silva, nascido em 1892, professor emérito do Instituto Nacional de Música, atual Escola de Música da UFRJ. Um de seus alunos foi Tom Jobim, que relatou a formalidade e a seriedade como características suas. Os sete volumes da coleção são acompanhados por um site que disponibiliza diversos materiais - oficinas, vídeos, planos de aula, banco de imagem, em torno de personagens negros biografados (http://personagensdoposabolicao.uff.br/). Apesar de grandes contribuições para a história republicana do Brasil, esses personagens tiveram suas vidas silenciadas, esquecidas ou não reconhecidas. Foram homens e mulheres marcados pela condição racial e de gênero que levantaram bandeiras antirracistas e atuaram na transformação das possibilidades de exercício da cidadania da população negra no Brasil. As biografias publicadas também trazem uma contribuição importante para o público em geral, para futuros professores e para os alunos da educação básica, pois permitem conhecer melhor a História do pós-abolição e do racismo no Brasil e, em volume especial, entrar em contato com novas formas de ensinar e aprender histórias do Brasil republicano.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Raça, História e Educação no Brasil e em Portugal: desafios e perspectivas

This article proposes a dialogue between the political and academic debates on race, identity, and history in the Brazilian and Portuguese contexts. In order to do so, it examines the myth of racial democracy (as it was known in Brazil) and the idea of a national vocation for interculturality in Portugal to explore how they shape the contemporary debate on racism and Eurocentrism, as well its evasion, focusing on education - which is understood as an arena for important political struggles. By addressing crucial moments in these debates, this article seeks to contribute to wider discussions on race and power in the teaching of history, and to challenge the depoliticization of contemporary narratives that continue to take refuge in the tropes of the historical specificities of each of the national contexts.Este artigo propõe um diálogo entre os debates políticos e acadêmicos sobre raça, identidade e história nos contextos brasileiro e português. Para tal, examina a relação entre o mito da democracia racial (como ficou conhecido no Brasil) e a ideia de uma vocação nacional para a interculturalidade em Portugal e o debate contemporâneo sobre racismo e eurocentrismo, assim como a sua evasão, focando na educação – tomada como palco de importantes lutas políticas. Abordando momentos cruciais destes debates, o artigo procura aprofundar a discussão sobre raça e poder no ensino da História e contestar a despolitização das narrativas contemporâneas que continuam a escudar-se nas especificidades históricas de cada um dos contextos nacionais

Updating mining reserves with uncertainty data

In mining operations, the time delay between grade estimations and decision about the scheduling of stopes mining can result in seriously outdated information and, consequently, a substantial mined reserves bias. To mitigate this gap between the grade estimation of an orebody and its exploitation, this paper proposes a new method of speedily updating resources and reserves integrated into the concept of real-time mining. This consists in the continuous and swift update of mine reserves, which requires a continuous and fast stream of the measurements of stopes in an underground mine rather than the chemical lab analysis of core samples or chip/face samples. Here we propose using portable for the swift monitoring of ore grades. However, this “fast” data be highly uncertain. For this reason, the first step consists of creating a bidistribution function between “uncertain” XRF and the corresponding “hard” measurements, based on empirical historical data. Following this, the uncertainty of the XRF measurements is derived from those bi-distributions through the conditional distribution of real values given to the known XRF measurement.The second step involves updating the reserves by integrating this uncertain XRF data, which has been quantified by conditional distributions, in the grade characterization models. For this purpose, a stochastic simulation with point distributions is applied. A case study of a sulphide copper deposit illustrates the proposed methodology