Trace elements and Pb isotope variations in galena from the onça gold deposit, Mato Grosso, Brazil: fluid mixing from hydrothermal and crustal sources

This study deals with the petrography of sulfídes and quartz veins, Pb isotopes, major and trace elements in galena, microthermometry and Raman spectrometry of fluid inclusions, with the objective of delineating temporal and spatial aspects of the fluid circulation patterns during the origin of the Onça gold deposit, Mato Grosso State, Brazil. The Pb isotope and mineral chemistry data indicate variable sources for the Pb isotopes, major (S and Pb) and trace elements (Sb, Ag, Zn and Se), with increases or decreases of the contents during the growth of the galena crystals. The results suggest that the variation may be due to the contamination of the hydrothermal solution by mixing with components derived from supracrustal host rocks of Pontes e Lacerda metavolcanic-sedimentary sequence. The mineral chemistry and fluids inclusion studies suggest two possible sources for the hydrothermal solutions: (1) deep solutions that originated during the regional metamorphism represented by the Aguapeí metamorphic event where the solutions present aqueous-carbonic composition and Iow salinity. Geologic control of the mineralization is in agreement with this hypothesis because the ore bodies are syntectonic with foliation formed during the Aguapeí event; (2) high contents of base metais indicates a plutonic influence in the origin of the fluids. Geologic controls also are in agreement with this hypothesis because pegmatitic intrusion was synchronous with the mineralizations. The Pb isotope and fluid inclusion relations allows the conclusions that the compositions of the hydrothermal solutes were variable during the emplacement of the quartz veins and the growth of galena crystals. The earlier solutes had hydrocarbons and were more radiogenic, whereas the later solutes had base metais and were less radiogenic. The Onça deposit originated during a metamorphic event by the effect of hydrothermal solutions related to plutonism, and with an important contribution from the host rocks as recorded by the influence of isotope, major and trace element compositions on the growth of ore-forming minerais.Este estudo compreende petrografia de sulfetos e veios de quartzo, elementos traços, maiores e isótopos de Pb em galena, microtermometria e espectrometria Raman em inclusões fluidas com o objetivo de delinear aspectos temporais e espaciais da circulação de fluídos durante a origem do depósito aurífero do Onça, Estado do Mato Grosso. Os resultados de isótopos de Pb e a química mineral indicam uma fonte variável para os isótopos de Pb e para elementos maiores (S e Pb) e elementos traços (Sb, Ag, Zn e Se) com aumentos e diminuições nos seus conteúdos durante o crescimento dos cristais de galena de forma que esta variação pode ser resultado da contaminação da solução hidrotermal pelas rochas supracrustais encaixantes da Seqüência Metavulcano-sedimentar Pontes e Lacerda. A química mineral e o estudo das inclusões fluídas sugerem dois tipos de fontes para as soluções hidrotermais: (1) soluções originadas em profundidade durante o metamorfismo regional representado pelo evento Aguapeí, com soluções aquocarbônicas e de baixa salinidade, hipótese corroborada pela concordância dos corpos de minério com a foliação regional gerada por este evento; (2) altos valores de metais básicos indicam uma influência plutônica na origem dos fluídos. Os isótopos de Pb e os estudos de inclusões fluídas analisadas conjuntamente permitem concluir que a composição das soluções hidrotermais foram variáveis durante o emplacement dos veios de quartzo e o crescimento dos cristais de galena. As soluções iniciais apresentam CR, na sua composição e são mais radiogênicas. As soluções finais apresentam metais básicos em sua composição e são menos radiogênicos. Como conclusão é possível sugerir que o depósito do Onça foi originado durante um evento metamórfico por soluções hidrotermais com influência de plutonismo, com uma importante contribuição das rochas encaixantes na composição isotópica do Pb, nos elementos maiores e traços durante o crescimento dos minerais de minério

What is beyond coherent pairs of orthogonal polynomials?

AbstractUsually, coherent pairs of orthogonal polynomials have been considered in the wider context of Sobolev orthogonality. In this paper, we focus our attention on the problem of coherence between two orthogonal polynomial sequences in terms of the corresponding linear functionals. We deduce some conditions about the linear functionals in order that the corresponding orthogonal polynomial sequences constitute a coherent pair

Revealing the usefulness of aroma networks to explain wine aroma properties: A case study of Portuguese wines

Wine aroma is the result of complex interactions between volatile compounds and non-volatile ones and individual perception phenomenon. In this work, an aroma network approach, that links volatile composition (chromatographic data) with its corresponding aroma descriptors was used to explain the wine aroma properties. This concept was applied to six monovarietal wines from Bairrada Appellation (Portugal) and used as a case study. A comprehensive determination of the wines’ volatile composition was done (71 variables, i.e., volatile components), establishing a workflow that combines extraction techniques and gas chromatographic analysis. Then, a bipartite network-based approach consisting of two different nodes was built, one with 19 aroma descriptors, and the other with the corresponding volatile compound(s). To construct the aroma networks, the odor active values were calculated for each determined compound and combined with the bipartite network. Finally, the aroma network of each wine was compared with sensory descriptive analysis. The analysis of the specific aroma network of each wine revealed that Sauvignon Blanc and Arinto white wines present higher fruity (esters) and sweet notes (esters and C13 norisoprenoids) than Bical wine. Sauvignon Blanc also exhibits higher toasted aromas (thiols) while Arinto and Bical wines exhibit higher flowery (C13 norisoprenoids) and herbaceous notes (thiols), respectively. For red wines, sweet fruit aromas are the most abundant, especially for Touriga Nacional. Castelão and Touriga Nacional wines also present toasted aromas (thiols). Baga and Castelão wines also exhibit fusel/alcohol notes (alcohols). The proposed approach establishes a chemical aroma fingerprint (aroma ID) for each type of wine, which may be further used to estimate wine aroma characteristics by projection of the volatile composition on the aroma network

Petrology and geochemistry of the banded iron formation in the Eastern Sierras Pampeanas of San Luis (Argentina) : Implications for the evolution of the Nogolí Metamorphic Complex

The metamorphosed banded iron formation from the Nogolí Metamorphic Complex of western Sierra de San Luis, Eastern Sierras Pampeanas of Argentina (Nogolí area, 32°55'S-66°15'W) is classified as an oxide facies iron formation of Algoma Type, with a tectonic setting possibly associated with an island arc or back arc, on the basis of field mapping, mineral and textural arrangements and whole rock geochemical features. The origin of banded iron formation is mainly related to chemical precipitation of hydrogenous sediments from seawater in oceanic environments. The primary chemical precipitate is a result of solutions that represent mixtures of seawater and hydrothermal fluids, with significant dilution by mafic-ultramafic volcanic and siliciclastic materials. Multi-stage TDM model ages of 1670, 1854 and 1939 Ma and positive, mantle-like ξ Nd(1502) values of +3.8, +1.5 and +0.5 from the banded iron formation are around the range of those mafic to ultramafic meta-volcanic rocks of Nogolí Metamorphic Complex, which are between 1679 and 1765 Ma and +2.64 and +3.68, respectively. This Sm and Nd isotopic connection suggests a close genetic relationship between ferruginous and mafic-ultramafic meta-volcanic rocks, as part of the same island arc or back arc setting. A previous Sm-Nd whole rock isochron of ∼1.5 Ga performed on mafic-ultramafic meta-volcanic rocks led to the interpretation that chemical sedimentation as old as Mesoproterozoic is possible for the banded iron formation. A clockwise P-T path can be inferred for the regional metamorphic evolution of the banded iron formation, with three distinctive trajectories: (1) Relict prograde M1-M3 segment with gradual P and T increase from greenschist facies at M1 to amphibolite facies at M3. (2) Peak P-T conditions at high amphibolite-low granulite facies during M4. (3) Retrograde counterpart of M4, that returns from amphibolite facies and stabilizes at greenschist facies during M5. Each trajectory may be regarded as produced by different tectonic events related to the Pampean? (1) and the Famatinian (2 and 3) orogenies, during the Early to Middle Paleozoic. The Nogolí Metamorphic Complex is interpreted as part of a greenstone belt within the large Meso- to Neoproterozoic Pampean Terrane of the Eastern Sierras Pampeanas of Argentina.El mapeo de campo, la mineralogía y texturas y las características geoquímicas de roca total de la formación ferrífera bandeada metamorfizada del Complejo Metamórfico Nogolí, Sierras Pampeanas Orientales de Argentina (área de Nogolí, 32°55’S – 66°15’O) permiten clasificarla como una formación ferrífera de facies de óxidos y tipo Algoma. El ambiente tectónico se asocia posiblemente con un arco de islas o retroarco. El origen del BIF está relacionado principalmente con precipitación química de sedimentos hidrógenos desde el agua de mar en ambientes oceánicos. El precipitado químico primario es un resultado de soluciones que representan mezcla de agua de mar y fluidos hidrotermales, y significativa disolución con materiales silicoclásticos y volcánicos máficoultramáficos. El BIF tiene edades modelo TDM de 1670, 1854 y 1939 Ma y valores mantélicos positivos de ξNd(1502) de +3.8, +1.5 y +0.5, que están en el rango de aquellos de las rocas volcánicas máficas-ultramáficas del Complejo Metamórfico Nogolí, cuyos valores varían entre 1679 - 1765 Ma y +2.64 a +3.68 respectivamente. Esta conexión isotópica Sm-Nd sugiere una estrecha vinculación genética entre las rocas volcánicas máficas-ultramáficas y las ferruginosas, como parte del mismo ambiente da arco de islas o retroarco. Una isocrona Sm-Nd roca total previa, proveniente de las rocas volcánicas máficas-ultramáficas, de ~1.5 Ga permite interpretar que para el BIF es posible una edad de sedimentación química tan antigua como Mesoproterozoico. Un patrón P-T horario puede ser inferido para la evolución metamórfica regional del BIF, con tres trayectorias distintivas: (1) Segmento relíctico progrado M1-M3, con incremento gradual de P y T desde facies esquistos verdes en M1 hasta facies anfibolita en M3. (2) Pico de P-T en facies anfibolita alta-granulita baja durante M4. (3) Contraparte retrógrada de M4, que retorna desde facies anfibolita y se estabiliza en facies esquistos verdes durante M5. Cada trayectoria puede ser vinculada con diferentes eventos tectónicos relacionados con las orogenias Pampeana? (1) y Famatiniana (2 y 3) del Paleozoico Temprano a Medio. El Complejo Metamórfico Nogolí es interpretado como parte de un greenstone belt dentro del Terreno Pampeano de edad meso- a neoproterozoica de las Sierras Pampeanas Orientales de Argentina.Centro de Investigaciones Geológica

Petrology and geochemistry of the banded iron formation in the Eastern Sierras Pampeanas of San Luis (Argentina) : Implications for the evolution of the Nogolí Metamorphic Complex

The metamorphosed banded iron formation from the Nogolí Metamorphic Complex of western Sierra de San Luis, Eastern Sierras Pampeanas of Argentina (Nogolí area, 32°55'S-66°15'W) is classified as an oxide facies iron formation of Algoma Type, with a tectonic setting possibly associated with an island arc or back arc, on the basis of field mapping, mineral and textural arrangements and whole rock geochemical features. The origin of banded iron formation is mainly related to chemical precipitation of hydrogenous sediments from seawater in oceanic environments. The primary chemical precipitate is a result of solutions that represent mixtures of seawater and hydrothermal fluids, with significant dilution by mafic-ultramafic volcanic and siliciclastic materials. Multi-stage TDM model ages of 1670, 1854 and 1939 Ma and positive, mantle-like ξ Nd(1502) values of +3.8, +1.5 and +0.5 from the banded iron formation are around the range of those mafic to ultramafic meta-volcanic rocks of Nogolí Metamorphic Complex, which are between 1679 and 1765 Ma and +2.64 and +3.68, respectively. This Sm and Nd isotopic connection suggests a close genetic relationship between ferruginous and mafic-ultramafic meta-volcanic rocks, as part of the same island arc or back arc setting. A previous Sm-Nd whole rock isochron of ∼1.5 Ga performed on mafic-ultramafic meta-volcanic rocks led to the interpretation that chemical sedimentation as old as Mesoproterozoic is possible for the banded iron formation. A clockwise P-T path can be inferred for the regional metamorphic evolution of the banded iron formation, with three distinctive trajectories: (1) Relict prograde M1-M3 segment with gradual P and T increase from greenschist facies at M1 to amphibolite facies at M3. (2) Peak P-T conditions at high amphibolite-low granulite facies during M4. (3) Retrograde counterpart of M4, that returns from amphibolite facies and stabilizes at greenschist facies during M5. Each trajectory may be regarded as produced by different tectonic events related to the Pampean? (1) and the Famatinian (2 and 3) orogenies, during the Early to Middle Paleozoic. The Nogolí Metamorphic Complex is interpreted as part of a greenstone belt within the large Meso- to Neoproterozoic Pampean Terrane of the Eastern Sierras Pampeanas of Argentina.El mapeo de campo, la mineralogía y texturas y las características geoquímicas de roca total de la formación ferrífera bandeada metamorfizada del Complejo Metamórfico Nogolí, Sierras Pampeanas Orientales de Argentina (área de Nogolí, 32°55’S – 66°15’O) permiten clasificarla como una formación ferrífera de facies de óxidos y tipo Algoma. El ambiente tectónico se asocia posiblemente con un arco de islas o retroarco. El origen del BIF está relacionado principalmente con precipitación química de sedimentos hidrógenos desde el agua de mar en ambientes oceánicos. El precipitado químico primario es un resultado de soluciones que representan mezcla de agua de mar y fluidos hidrotermales, y significativa disolución con materiales silicoclásticos y volcánicos máficoultramáficos. El BIF tiene edades modelo TDM de 1670, 1854 y 1939 Ma y valores mantélicos positivos de ξNd(1502) de +3.8, +1.5 y +0.5, que están en el rango de aquellos de las rocas volcánicas máficas-ultramáficas del Complejo Metamórfico Nogolí, cuyos valores varían entre 1679 - 1765 Ma y +2.64 a +3.68 respectivamente. Esta conexión isotópica Sm-Nd sugiere una estrecha vinculación genética entre las rocas volcánicas máficas-ultramáficas y las ferruginosas, como parte del mismo ambiente da arco de islas o retroarco. Una isocrona Sm-Nd roca total previa, proveniente de las rocas volcánicas máficas-ultramáficas, de ~1.5 Ga permite interpretar que para el BIF es posible una edad de sedimentación química tan antigua como Mesoproterozoico. Un patrón P-T horario puede ser inferido para la evolución metamórfica regional del BIF, con tres trayectorias distintivas: (1) Segmento relíctico progrado M1-M3, con incremento gradual de P y T desde facies esquistos verdes en M1 hasta facies anfibolita en M3. (2) Pico de P-T en facies anfibolita alta-granulita baja durante M4. (3) Contraparte retrógrada de M4, que retorna desde facies anfibolita y se estabiliza en facies esquistos verdes durante M5. Cada trayectoria puede ser vinculada con diferentes eventos tectónicos relacionados con las orogenias Pampeana? (1) y Famatiniana (2 y 3) del Paleozoico Temprano a Medio. El Complejo Metamórfico Nogolí es interpretado como parte de un greenstone belt dentro del Terreno Pampeano de edad meso- a neoproterozoica de las Sierras Pampeanas Orientales de Argentina.Centro de Investigaciones Geológica

Carbohydrates as targeting compounds to produce infusions resembling espresso coffee brews using quality by design approach

All coffee brews are prepared with roasted coffee and water, giving origin to espresso, instant, or filtered coffee, exhibiting distinct physicochemical properties, depending on the extraction conditions. The different relative content of compounds in the brews modulates coffee body, aroma, and colour. In this study it was hypothesized that a coffee infusion allows to obtain extracts that resemble espresso coffee (EC) physicochemical properties. Carbohydrates (content and composition) were the target compounds as they are organoleptically important for EC due to their association to foam stability and viscosity. The freeze-drying of the extracts allowed better dissolution properties than spray-drying. Instant coffee powders were obtained with chemical overall composition resembling espresso, although with lower lipids content. The extracts were able to produce the characteristic foam through CO2 injection or salts addition. Their redissolution at espresso concentration allowed a viscosity, foamability and volatile profile representative of an espresso coffee, opening new exploitation possibilities.Thanks are due to the University of Aveiro and FCT/MCT for the financial support for the QOPNA research Unit (FCT UID/QUI/00062/2019) and the LAQV-REQUIMTE (UIDB/50006/2020) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. The authors thank FCT co-financed by Programa Operacional Competitividade e Internacionalização, Portugal 2020 and União Europeia by the FEDER (FCT - Compete2020 - Portugal 2020 – FEDER/EU) N° POCI-01-0145-FEDER-029560, project “PulManCar”. Guido R. Lopes was supported by an individual doctoral grant by FCT (SFRH/BD/104855/2014). Sílvia Petronilho (SFRH/BPD/117213/2016) and Cláudia P. Passos (CEECIND/00813/2017) also thanked FCT for the Post-doc grant and the assistant research contract, respectively. The authors thank Prof. Margarida Almeida for the use of spray-drying facilities and Ana Bastos for the help in the equipment operation.info:eu-repo/semantics/publishedVersio

Transnational cooperation in enhancing researchers’ wider employability: the TRANSPEER project

The purpose of this paper is to provide an example of best practice towards enhancing employability in the cross-sectoral labour market for doctorate-holders. This was achieved through an Erasmus+ KA2 (Strategic Partnership) skills development project which created a training programme (TRANSPEER) involving a multi-disciplinary cohort of researchers at a range of career stages, drawn from universities in Norway, Portugal, Sweden and the UK.info:eu-repo/semantics/publishedVersio

Potato Chips Byproducts as Feedstocks for Developing Active Starch-Based Films with Potential for Cheese Packaging

publishedVersio

Exercise training prevents skeletal muscle damage in an experimental sepsis model

OBJECTIVE: Oxidative stress plays an important role in skeletal muscle damage in sepsis. Aerobic exercise can decrease oxidative stress and enhance antioxidant defenses. Therefore, it was hypothesized that aerobic exercise training before a sepsis stimulus could attenuate skeletal muscle damage by modulating oxidative stress. Thus, the aim of this study was to evaluate the effects of aerobic physical preconditioning on the different mechanisms that are involved in sepsis-induced myopathy. METHODS: Male Wistar rats were randomly assigned to either the untrained or trained group. The exercise training protocol consisted of an eight-week treadmill program. After the training protocol, the animals from both groups were randomly assigned to either a sham group or a cecal ligation and perforation surgery group. Thus, the groups were as follows: sham, cecal ligation and perforation, sham trained, and cecal ligation and perforation trained. Five days after surgery, the animals were euthanized and their soleus and plantaris muscles were harvested. Fiber cross-sectional area, creatine kinase, thiobarbituric acid reactive species, carbonyl, catalase and superoxide dismutase activities were measured. RESULTS: The fiber cross-sectional area was smaller, and the creatine kinase, thiobarbituric acid reactive species and carbonyl levels were higher in both muscles in the cecal ligation and perforation group than in the sham and cecal ligation and perforation trained groups. The muscle superoxide dismutase activity was higher in the cecal ligation and perforation trained group than in the sham and cecal ligation and perforation groups. The muscle catalase activity was lower in the cecal ligation and perforation group than in the sham group. CONCLUSION: In summary, aerobic physical preconditioning prevents atrophy, lipid peroxidation and protein oxidation and improves superoxide dismutase activity in the skeletal muscles of septic rats