1,305 research outputs found

    Sulfide recrystallization and gold remobilization during the 2.0 Ga stage of the Minas Orogeny: implications for gold mineralization in the Quadrilátero Ferrífero area, Brazil

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    The historic Quadrilátero Ferrífero mining district in Brazil is a polydeformed Archean terrane recording several tectonic events. This history has hampered the accurate dating of its important gold deposits, given that most of the geochronological clocks have been affected by multiple thermal events. To determine an accurate time constraint for the mineralizing events in this region, we provide the first Re-Os dating for a gold deposit in the Quadrilátero Ferrífero, obtained from 13 mineral separates of disseminated sulfide phases (pyrrhotite, coarse-grained arsenopyrite, fine-grained arsenopyrite, and pyrite) at the recently discovered São Sebastião deposit (northwest Quadrilátero Ferrífero). Three distinct successive sulfidation stages are interpreted at the deposit. The final stage, texturally associated with gold, is marked by fine-grained arsenopyrite and pyrite (assemblage III) and is associated with high-temperature (~600°C) features. A Re-Os errorchron is obtained when considering the data of all samples collectively; however, a comprehensive Re-Os isochron age of 1987 ± 72 Ma (2σ; n = 4; IsoplotR model 3; initial 187Os/188Os = 2.1 ± 0.7) is obtained from assemblage III. A 187Re-187Osr isochron at 1988 ± 56 Ma (mean square of weighted deviates = 0.1, initial 187Osr = –0.1 ± 2.6 ppt; n = 4) is obtained if an initial 187Os/188Os composition of ca. 2.1, is used, this being consistent with the fact that the 187Os in the sulfides in assemblage III is largely radiogenic (187Osr). Earlier assemblages (I and II) individually show variable initial 187Os/188Os, indicative of disturbance to the Re-Os systematics at ~2.0 Ga. This age is considered the best estimate for the timing of gold mineralization at São Sebastião, being coincident with the waning stages of the Minas orogeny, the thermal effects of which are restricted to the southern Quadrilátero Ferrífero. Hence, we consider that the hot fluids from which assemblage III crystallized were responsible for resetting the Re-Os systematics in assemblages I and II and were central to Paleoproterozoic gold deposition in the region. This ~2.0 Ga age challenges previous notions of a late Archean, ~2.7 Ga mineralizing event in the Quadrilátero Ferrífero and makes it possible that gold remobilization occurred elsewhere in the region, particularly in areas representing deeper crustal levels

    Desenvolvimento de tempero de pequi na forma de tablete: formulação e avaliação físico-química e sensorial

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    Summary The proximate composition and acceptability of bouillon cubes prepared from souari nut pulp flour were evaluated. The whole fruit pulp and formulated bouillon cubes were subjected to an analysis of the total phenolic compounds, protein, lipid, moisture, ash, fibre, total carbohydrate and total energy values. The selected formulations of souari nut bouillon cubes were subjected to a sensory analysis as seasoning for rice preparations, and the physicochemical analysis of the most widely preferred formulation was carried out. The whole souari nut pulp was found to contain 44.4% moisture, 37.7% lipids, 2.1% protein and 10.9% total carbohydrates, as well as 324 mg of total phenolic compounds per 100 g of pulp. The souari flour contained 9.8% moisture. In the sensory tests, the preferred formulation was that containing the highest souari nut flour concentration. This formulation contained 8.4% moisture, 52.3% lipids, 3.1% protein, 19.4% total carbohydrate, 321 mg of phenolic compounds per 100 g and a total energy value of 560.7 kcal per 100 g. The souari nut bouillon cubes presented the characteristic colour, taste and aroma of the fruit and an appearance similar to that of commercial bouillon cubes.A composição centesimal e a aceitabilidade de um tempero culinário em forma de tablete preparado da polpa de pequi desidratada foram avaliadas. A polpa de pequi integral e os tabletes formulados foram submetidos às determinações dos valores de compostos fenólicos totais, proteínas totais, lipídios, umidade, cinzas, fibra bruta, carboidratos totais e valor energético total. Depois da seleção das formulações para o preparo dos tabletes de pequi, estes foram submetidos à avaliação sensorial como condimento para o preparo de arroz. Na polpa do pequi, foram encontrados 44,4% de umidade, 37,7% de lipídeos, 2,1% de proteínas, 10,9% de carboidratos totais e 324 mg de compostos fenólicos totais por 100 g. A farinha da polpa de pequi apresentou 9,8% de umidade. Nos testes sensoriais, a formulação preferida foi aquela com maior quantidade de polpa do fruto na forma de farinha. Esta formulação apresentou 8,4% de umidade, 52,3% de gordura, 3,1% de proteínas, 19,4% de carboidratos totais, 321 mg de compostos fenólicos por 100 g e um valor energético total de 560,7 kcal por 100 g. Os tabletes de pequi produzidos mantiveram a cor, o sabor e o aroma característicos do fruto e apresentação similar aos caldos em cubo comerciais.19

    Desenvolvimento De Tempero De Pequi Na Forma De Tablete: Formulação E Avaliação Físico-química E Sensorial

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    The proximate composition and acceptability of bouillon cubes prepared from souari nut pulp flour were evaluated. The whole fruit pulp and formulated bouillon cubes were subjected to an analysis of the total phenolic compounds, protein, lipid, moisture, ash, fibre, total carbohydrate and total energy values. The selected formulations of souari nut bouillon cubes were subjected to a sensory analysis as seasoning for rice preparations, and the physicochemical analysis of the most widely preferred formulation was carried out. The whole souari nut pulp was found to contain 44.4% moisture, 37.7% lipids, 2.1% protein and 10.9% total carbohydrates, as well as 324 mg of total phenolic compounds per 100 g of pulp. The souari flour contained 9.8% moisture. In the sensory tests, the preferred formulation was that containing the highest souari nut flour concentration. This formulation contained 8.4% moisture, 52.3% lipids, 3.1% protein, 19.4% total carbohydrate, 321 mg of phenolic compounds per 100 g and a total energy value of 560.7 kcal per 100 g. The souari nut bouillon cubes presented the characteristic colour, taste and aroma of the fruit and an appearance similar to that of commercial bouillon cubes.1

    Do masculine men smell better? An association between skin color masculinity and female preferences for body odor

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    This work was supported by Fundação para a Ciência e a Tecnologia and Programa Operacional de Potencial Humano/Fundo Social Europeu (SFRH/BD/77592/2011 to M.L.C.).A recent study claimed face skin color as a sexually dimorphic variable that influences attractiveness preferences in mate choice. Thereby, skin color may assume the role of a mate quality signal influencing attractiveness preferences. As body odor is linked to attractiveness, this study aimed to explore whether the odors of men with more masculine facial skin color would be evaluated more positively than odors from less masculine men. Female raters were presented with body odors of 18 men and were asked to rate them in various characteristics. Multilevel modelling revealed that the odors of the donors with more masculine color were rated not only as more attractive, more pleasant, and sexier, but also healthier. This indicates that odor associated with men with more masculine skin color is attractive, just as other sexually dimorphic traits. Furthermore, we found a negative relation between skin color masculinity and perceived odor maleness. Regarding this last finding, a new discussion is introduced with respect to the influence of cognitive stereotypes in odor judgments. Altogether, the study supports the possibility that chemosensory signals may be communicating signs of mate quality associated with masculinity.PostprintPeer reviewe

    Rheumatic Myocarditis: A Poorly Recognized Etiology of Left Ventricular Dysfunction in Valvular Heart Disease Patients

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    Background: Heart failure occurs in ~10% of patients with acute rheumatic fever (RF), and several studies have shown that cardiac decompensation in RF results primarily from valvular disease and is not due to primary myocarditis. However, the literature on this topic is scarce, and a recent case series has shown that recurrent RF can cause ventricular dysfunction even in the absence of valvular heart disease.Methods: The present study evaluated the clinical, laboratory and imaging characteristics of 25 consecutive patients with a clinical diagnosis of myocarditis confirmed by 18F-FDG PET/CT or gallium-67 cardiac scintigraphy and RF reactivation according to the revised Jones Criteria. Patients underwent three sequential echocardiograms at (1) baseline, (2) during myocarditis and (3) post corticosteroid treatment. Patients were divided according to the presence (Group 1) or absence (Group 2) of reduced left ventricular ejection fraction (LVEF) during myocarditis episodes.Results: The median age was 42 (17–51) years, 64% of patients were older than 40 years, and 64% were women. Between Group 1 (n = 16) and in Group 2 (n = 9), there were no demographic, echocardiographic or laboratory differences except for NYHA III/IV heart failure (Group 1: 100.0% vs. Group 2: 50.0%; p = 0.012) and LVEF (30 [25–37] vs. 56 [49–62]%, respectively; p < 0.001), as expected. Group 1 patients showed a significant reduction in LVEF during carditis with further improvement after treatment. There was no correlation between LVEF and valvular dysfunction during myocarditis. Among all patients, 19 (76%) underwent 18F-FDG PET/CT, with a positive scan in 68.4%, and 21 (84%) underwent gallium-67 cardiac scintigraphy, with positive uptake in 95.2%, there was no difference between these groups.Conclusion: Myocarditis due to rheumatic fever reactivation can cause left ventricular dysfunction despite valvular disease, and it is reversible after corticosteroid treatment

    Edge states in a two-dimensional honeycomb lattice of massive magnetic skyrmions

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    We study the collective dynamics of a two-dimensional honeycomb lattice of magnetic skyrmions. By performing large-scale micromagnetic simulations, we find multiple chiral and non-chiral edge modes of skyrmion oscillations in the lattice. The non-chiral edge states are due to the Tamm-Shockley mechanism, while the chiral ones are topologically protected against structure defects and hold different handednesses depending on the mode frequency. To interpret the emerging multiband nature of the chiral edge states, we generalize the massless Thiele's equation by including a second-order inertial term of skyrmion mass as well as a third-order non-Newtonian gyroscopic term, which allows us to model the band structure of skrymion oscillations. Theoretical results compare well with numerical simulations. Our findings uncover the importance of high order effects in strongly coupled skyrmions and are helpful for designing novel topological devices.Comment: 6 pages,4 figures,accepted by Physical Review B as a Rapid Communicatio

    Engolo and Capoeira. From Ethnic to Diasporic Combat Games in the Southern Atlantic

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    This article provides a re-examination of the main Afrocentric narrative of capoeira origins, the engolo or ‘Zebra Dance’, in light of historical primary sources and new ethnographic evidence gathered during fieldwork in south-west Angola. By examining engolo’s bodily techniques, its socio-historical context and cultural meanings, the piece emphasises its insertion into a pastoral lifestyle and highlights the relatively narrow ethnic character of the practice in Angola. This analysis and the comparison with capoeira helps us to develop certain hypotheses about the formation, migration, and re-invention of diasporic combat games between southern Angola and coastal Brazil, and more broadly, to increase our understanding of how African cultures spread across the southern Atlantic

    Da fotografia como arte à arte como fotografia: a experiência do Museu de Arte Contemporânea da USP na década de 1970

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    Este ensaio visa sistematizar os primeiros resultados de uma pesquisa, ainda em curso, sobre o processo de legitimação da fotografia pelo sistema de arte no Brasil, cujo foco principal é o museu. Os museus de arte da cidade de São Paulo foram escolhidos para dar início a essa investigação. Primeiramente, será abordada, em linhas gerais, a presença da fotografia no Museu de Arte Moderna de São Paulo e na Bienal de São Paulo, dada a vinculação de origem do Museu de Arte Contemporânea com essas duas instituições paulistanas. Na seqüência será analisada a formação do acervo fotográfico do Museu de Arte Contemporânea da Universidade de São Paulo durante a década de 1970. Por fim, esse percurso permitirá observar que a atuação de Walter Zanini, o primeiro diretor do Museu, e as particularidades da posição do MAC-USP no sistema de arte no Brasil naquele período resultaram no entendimento da fotografia prioritariamente no âmbito da arte contemporânea de caráter experimental e não como obra de arte autônoma, segundo os princípios da chamada fotografia artística.This article presents the first findings of a research still under development about the process of legitimation of photography as a kind of art by the artistic scene in Brazil. The art museums of the city of São Paulo were chosen for starting that research. Initially, we will be investigating the presence of photography at the Contemporary Art Museum of São Paulo and at the Biennial of São Paulo, as the origin of the Contemporary Art Museum is tided to those two institutions. Following, the arrangement of the photographic technical reserve of the Contemporary Art Museum in the 1970s will be analyzed. This study will be focusing on the work of Walter Zanini, as the first director of the museum, and on the particularities of MAC-USP position in the art system in Brazil which resulted in the understanding of photography as belonging to the sphere of contemporary art in an experimental way and not as an autonomous work of art, according to the principals of the so called artistic photography

    A Lei da Mediação de Conflitos: estudos sobre a sua aplicação

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    Financiamento de MEDLaw - FCT UIDB/04112/2020.Os dez anos de vigência da Lei da Mediação em Portugal constituíram o mote para a compilação nesta obra de diversos estudos empírico-dogmáticos sobre a sua aplicação, analisando-se questões prementes como a voluntariedade ou obrigatoriedade da mediação, a executoriedade do acordo de mediação e a Convenção de Singapura, as exigências processuais e a suspensão dos prazos de prescrição e caducidade com o recurso à mediação, a organização associativa dos mediadores e a importância da sua formação, o funcionamento dos sistemas públicos de mediação, bem como novas áreas de aplicação da mediação, em especial no domínio administrativo e na recuperação extrajudicial de empresas, e ainda a relevância do desenvolvimento científico sobre este meio de resolução de conflitos. Ao regulamentar num único diploma, pela primeira vez no nosso ordenamento jurídico, a mediação pública e privada, a Lei n.º 29/2013, de 19 de abril, constituiu um marco legislativo. Dez anos volvidos, importava refletir sobre a sua aplicação prático-jurídica, norteados pelo objetivo de promover o estudo e a efetiva implementação da mediação de conflitos em Portugal. Esta obra constitui o output desenvolvido no âmbito do projeto de investigação MEDLAW, com o apoio da Fundação para a Ciência e Tecnologia, no âmbito do financiamento base atribuído ao polo de Leiria do Instituto Jurídico Portucalense, com a ref. UIDB/04112/2020.info:eu-repo/semantics/publishedVersio
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