O depósito de Sn-Li associado a granito de grande tonelagem da Argemela, Portugal central

The Argemela Sn-Li quartz vein stockwork, east of the Panasqueira tungsten mine, is hosted in Cambrian slates and greywacke. An underlying Variscan granitic cupola is inferred from spotted slates and albitic microgranite dykes, the last including a thick modified albitic microgranite, enriched in F and Li, exposed some 500 m away, on the hill top. Inferred resources for shallowest deposit portion are 20.1 million tonnes (Mt) at 0.1-0.2% Sn, 0.2% Li and 0.1% (estimate) Rb, but the 650-m vertical-extent of the deposit suggests a resource of >200 Mt (with identical grades). The hydrothermal paragenetic sequence is amblygonite-montebrasite (mostly montebrasite) (Stage I)–quartz I-II–cassiterite (with columbite-tantalite inclusions)─arsenopyrite I─carbonate I-white mica I ─chlorite I–fluorite–apatite–rutile (Stage II)– white mica II–molybdenite– tourmaline– carbonate II-quartz III–arsenopyrite II–sphalerite–stannite–chalcopyrite–pyrite– pyrrhotite-chlorite II (Stage III)–covellite– vivianite–goethite/lepidocrocite (Stage IV). Amblygonite-montebrasite is the main Li carrier; Sn is evenly distributed between cassiterite and stannite; Rb is mostly in white mica (with 0.25-1.23 wt % Rb2O in the hill-top albitic microgranite). Primary aqueous, 1-3 um-wide fluid inclusions in the deposit in quartz I, carbonate I, apatite and cassiterite growth zones yield overall salinities and homogenisation temperatures of 7.2-19.1 wt % NaCl equiv. and 290-360ºC, respectively. The trace concentrations (electronic microprobe analysis) in quartz vein cassiterite reach 1.95 wt % Nb, 0.39 wt % Fe, 0.13 wt % Ti, and low/negligible values of Sb, Zn, As, Ag and Bi showing its granite-hydrothermal affiliation. Fe-poor and Fe-rich sphalerite (lower-intermediate and upper deposit parts) contain 1.0-1.6 and 7.9-9.4 wt % Fe, 64.3-66.0 and 55.9-57.2 wt % Zn, 0.4-0.5 and 0.9-1.1 wt % Cd, respectively. The sphalerite-stannite geothermometer yields temperatures of 245-297ºC. Following higher temperature amblygonite-montebrasite deposition (Stage I), hydrothermal fluids (aCl-=0.25 m), related to the hidden granitic cupola, at a mean pressure-corrected (50 MPa) temperature of 350ºC, were responsible for Stage II minerals deposition. Calculated cassiterite deposition from Sn chloride complexes occurred likewise, from probable magmatic-hydrothermal fluids, at fO2 = 10-34 -10-32 atm and pH=3.5-4. Cassiterite deposition mechanisms were oxidation, mixing, neutralisation, possible aCl- increase, and cooling. Later Fe-poor sphalerite (+kesterite/ferrokesterite) and Fe-rich sphalerite (+stannite) deposited at higher and lower fS2, respectively, the latter probably at a higher fO2 (Stage III). The uniqueness of Argemela system with abundant amblygonite-montebrasite in hydrothermal quartz tin veins may be related to an extreme fractionated F-, Li- and P-rich granitic magma. After the emplacement of the granite/albitic microgranite dykes, an emerging pegmatitic fluid was unable, possibly due to insufficient depth, to form pegmatites but only modified the hill-top albitic microgranite. As a consequence, the system, where mixing of high- and low-salinity magmatic fluids probably occurred, remained very enriched in F, Li and P and by the time the hydrothermal stockwork developed amblygonite-montebrasite (Stage I) was the first mineral to deposit abundantly before Stage II minerals deposition in those Argemela Sn-Li quartz veins.El filón de cuarzo Sn-Li de Argemela, al este de la mina de wolframio de Panasqueira, está alojado en pizarras y gravas del Cámbrico. Se infiere una cúpula granítica subyacente del Varisco a partir de pizarras moteadas y diques de microgranito albítico, este último incluye un grueso microgranito albítico modificado, enriquecido en F y Li, expuesto a unos 500 m, en la cima de la colina. Los recursos inferidos para la parte más superficial del yacimiento son de 20,1 millones de toneladas (Mt) con 0,1-0,2% de Sn, 0,2% de Li y 0,1% (estimado) de Rb, pero la extensión vertical de 650 m del yacimiento sugiere un recurso de >200 Mt (con idénticas calidades). La secuencia paragénica hidrotermal es ambligonita-montebrasita (mayoritariamente montebrasita) (etapa I)-cuarzo I-II-casiterita (con inclusiones de columbita-tantalita)─arsenopirita I─carbonato I- mica blanca I ─clorita I-fluorita-apatita-rutilo (Estadio II)-mica blanca II-molibdenita-turmalina-carbonato II-cuarzo III-arsenopirita II-esfalerita-estanita-calcopirita-pirrotita-clorita II (Estadio III)-covellita-vivianita-goethita/lepidocrocita (Estadio IV). La ambligonita-montebrasita es el principal portador de Li; el Sn está distribuido uniformemente entre la casiterita y la estannita; el Rb se encuentra mayoritariamente en la mica blanca (con 0,25-1,23 % en peso de Rb2O en el microgranito albítico de la cima). Las inclusiones fluidas primarias acuosas de 1-3 um de ancho en el yacimiento en las zonas de crecimiento de cuarzo I, carbonato I, apatito y casiterita arrojan salinidades globales y temperaturas de homogeneización de 7,2-19,1 wt % de NaCl equiv. y 290-360ºC, respectivamente. Las concentraciones de trazas (análisis por microsonda electrónica) en la casiterita de las vetas de cuarzo alcanzan el 1,95 % en peso de Nb, el 0,39 % en peso de Fe, el 0,13 % en peso de Ti, y valores bajos/negligibles de Sb, Zn, As, Ag y Bi, lo que demuestra su filiación granítica-hidrotermal. La esfalerita pobre en Fe y rica en Fe (partes inferior-intermedia y superior del yacimiento) contienen 1,0-1,6 y 7,9-9,4 % en peso de Fe, 64,3-66,0 y 55,9-57,2 % en peso de Zn, 0,4-0,5 y 0,9-1,1 % en peso de Cd, respectivamente. El geotermómetro de esfalerita-estanita arroja temperaturas de 245-297ºC. Tras la deposición de ambligonita-montebrasita a mayor temperatura (Etapa I), los fluidos hidrotermales (aCl-=0,25 m), relacionados con la cúpula granítica oculta, a una temperatura media corregida por presión (50 MPa) de 350ºC, fueron los responsables de la deposición de minerales de la Etapa II. La deposición de casiterita calculada a partir de complejos de cloruro de Sn se produjo igualmente, a partir de probables fluidos magmáticos-hidrotermales, a fO2 = 10-34 -10-32 atm y pH=3,5-4. Los mecanismos de deposición de casiterita fueron la oxidación, la mezcla, la neutralización, el posible aumento de aCl- y el enfriamiento. Más tarde, la esfalerita pobre en Fe (+kesterita/ferrokesterita) y la esfalerita rica en Fe (+estanita) se depositaron a una fS2 más alta y más baja, respectivamente, esta última probablemente a una fO2 más alta (estadio III). La singularidad del sistema de Argemela, con abundante ambligonita-montebrasita en las vetas hidrotermales de cuarzo-estaño, puede estar relacionada con un magma granítico extremadamente rico en F, Li y P. Tras el emplazamiento de los diques de granito/microgranito albítico, un fluido pegmatítico emergente fue incapaz, posiblemente debido a la insuficiente profundidad, de formar pegmatitas, sino que sólo modificó el microgranito albítico de la cima. Como consecuencia, el sistema, en el que probablemente se produjo la mezcla de fluidos magmáticos de alta y baja salinidad, permaneció muy enriquecido en F, Li y P y, en el momento en que se desarrolló el stockwork hidrotermal, la ambligonita-montebrasita (Etapa I) fue el primer mineral que se depositó abundantemente antes de la deposición de los minerales de la Etapa II en esas vetas de cuarzo con Sn-Li de Argemela

Effects of a plyometric training program in sub-elite futsal players during pre-season period

Plyometric training (PT) programs can improve several motor skills during the pre-season. Even so, its impact during the pre-season specifically in futsal remains unclear. Objective: The present observational study examines the impact of a six-week PT program that included varied strength exercises in adult male futsal players. Method: Fourteen futsal players from a Portuguese men’s sub-elite team that competed in a national championship (mean ± Standard deviation (SD) age: 25.78±7.05 years) were included in this cross-sectional study that analyzed the consequences of a PT program during the pre-season, followed by four weeks of detraining. Players were monitored 3 times: at the beginning, after six weeks of PT and four weeks after the end of PT. Results: The current research presented significant mean changes with the application of the training program in the three assessment moments for agility (small to moderate effect), countermovement jump (CMJ) height (trivial to small effect), and sprint performance (trivial to moderate large effect). When assessing the mean differences between pre- and post-training, the differences are more evident in their magnitude (Δ = -12.73 to 3.69%, d = 0.38 to 2.08). Furthermore, the PT program showed the greatest influence on 20 m sprint with a large effect (Δ = -12.73%, d = 2.08), followed by a small and moderate effect for agility (Δ = -6.46%, d = 0.85) and for the 10 m sprint (Δ = -3.53%, d = 0.38). Conclusions: These results confirmed the impact of a six-week plyometric training during the pre-season in sub-elite futsal players. This new evidence can be particularly useful in pre-season planning in futsal. (c) the author(s).This work is suppoted by national funding through the Portuguese Foundation for Science and Technology I.P., under project UIDB/04045/2020info:eu-repo/semantics/publishedVersio

Incidência E Mortalidade Por Aids Em Crianças E Adolescentes: Desafios Na Região Sul Do Brasil

The objective of this study is to describe the time trend of coefficients of incidence and mortality associated with AIDS in children and adolescents. An ecological time trend study was conducted among individuals under 14 living in the regional context of high incidence of AIDS – Porto Alegre and the State of Rio Grande do Sul – from 1996 to 2012. For this purpose, a segmented regression model was adjusted for age categories and place of residence. AIDS morbidity and mortality indicators in Porto Alegre are still higher than those registered in the State, the southern region and other areas of the country. In Porto Alegre, 59.1% of cases (371/628) occurred in children under four years of age, the incidence showed peaks in the period and the mortality dropped from 9 to 2 per 100,000. A significant decreasing in annual percentage change in mortality was observed especially in children under 1 year of age in Porto Alegre. This drop may be related to prevention and treatment of pregnant women. The challenge is to identify possible fragilities of the STD/AIDS Program and its vulnerable points in order to make specific interventions and investments with a greater impact potential. © 2016, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. All rights reserved.21123889389

Assessing foraging strategies of herbivores in Mediterranean oak woodlands: a review of key issues and selected methodologies.

Montados are agro-silvo-pastoral ecosystems, typical of the Southwest Iberian Peninsula, of high socio-economic and conservation importance,where grazing is a dominant activity. Montados are characterized by na open tree canopy of Quercus sp. and a diverse undercover of shrubs and grasslands that constitute the plant food resources for grazing animals. Plant food resources of Montados are highly variable, both spatially and seasonally, in quantity and quality. Reliable and easy to use methods to monitor grazing are necessary to allow proper understanding of foraging strategies of grazing animals and to set sustainable grazing management. We describe the main characteristics of the plant food resources available for grazing animals, striking its variability, and revise the potential of using N-alkanes and saliva

Adipocytes harbor a glucosylceramide biosynthesis pathway involved in iNKT cell activation

Background: Natural killer T (NKT) cells in adipose tissue (AT) contribute to whole body energy homeostasis. Results: Inhibition of the glucosylceramide synthesis in adipocytes impairs iNKT cell activity. Conclusion: Glucosylceramide biosynthesis pathway is important for endogenous lipid antigen activation of iNKT cells in adipocytes.Significance: Unraveling adipocyte-iNKT cell communication may help to fight obesity-induced AT dysfunction.Overproduction and/or accumulation of ceramide and ceramide metabolites, including glucosylceramides, can lead to insulin resistance. However, glucosylceramides also fulfill important physiological functions. They are presented by antigen presenting cells (APC) as endogenous lipid antigens via CD1d to activate a unique lymphocyte subspecies, the CD1d-restricted invariant (i) natural killer T (NKT) cells. Recently, adipocytes have emerged as lipid APC that can activate adipose tissue-resident iNKT cells and thereby contribute to whole body energy homeostasis. Here we investigate the role of the glucosylceramide biosynthesis pathway in the activation of iNKT cells by adipocytes.UDP-glucose ceramide glucosyltransferase (Ugcg), the first rate limiting step in the glucosylceramide biosynthesis pathway, was inhibited via chemical compounds and shRNA knockdown in vivo and in vitro. beta-1,4-Galactosyltransferase (B4Galt) 5 and 6, enzymes that convert glucosylceramides into potentially inactive lactosylceramides, were subjected to shRNA knock down. Subsequently, (pre)adipocyte cell lines were tested in co-culture experiments with iNKT cells (IFN gamma and 114 secretion).Inhibition of Ugcg activity shows that it regulates presentation of a considerable fraction of lipid self-antigens in adipocytes. Furthermore, reduced expression levels of either B4Galt5 or -6, indicate that B4Galt5 is dominant in the production of cellular lactosylceramides, but that inhibition of either enzyme results in increased iNKT cell activation. Additionally, in vivo inhibition of Ugcg by the aminosugar AMP-DNM results in decreased iNKT cell effector function in adipose tissue.Inhibition of endogenous glucosylceramide production results in decreased iNKT cells activity and cytokine production, underscoring the role of this biosynthetic pathway in lipid self-antigen presentation by adipocytes

Adipocytes harbor a glucosylceramide biosynthesis pathway involved in iNKT cell activation

Background: Natural killer T (NKT) cells in adipose tissue (AT) contribute to whole body energy homeostasis. Results: Inhibition of the glucosylceramide synthesis in adipocytes impairs iNKT cell activity. Conclusion: Glucosylceramide biosynthesis pathway is important for endogenous lipid antigen activation of iNKT cells in adipocytes.Significance: Unraveling adipocyte-iNKT cell communication may help to fight obesity-induced AT dysfunction.Overproduction and/or accumulation of ceramide and ceramide metabolites, including glucosylceramides, can lead to insulin resistance. However, glucosylceramides also fulfill important physiological functions. They are presented by antigen presenting cells (APC) as endogenous lipid antigens via CD1d to activate a unique lymphocyte subspecies, the CD1d-restricted invariant (i) natural killer T (NKT) cells. Recently, adipocytes have emerged as lipid APC that can activate adipose tissue-resident iNKT cells and thereby contribute to whole body energy homeostasis. Here we investigate the role of the glucosylceramide biosynthesis pathway in the activation of iNKT cells by adipocytes.UDP-glucose ceramide glucosyltransferase (Ugcg), the first rate limiting step in the glucosylceramide biosynthesis pathway, was inhibited via chemical compounds and shRNA knockdown in vivo and in vitro. beta-1,4-Galactosyltransferase (B4Galt) 5 and 6, enzymes that convert glucosylceramides into potentially inactive lactosylceramides, were subjected to shRNA knock down. Subsequently, (pre)adipocyte cell lines were tested in co-culture experiments with iNKT cells (IFN gamma and 114 secretion).Inhibition of Ugcg activity shows that it regulates presentation of a considerable fraction of lipid self-antigens in adipocytes. Furthermore, reduced expression levels of either B4Galt5 or -6, indicate that B4Galt5 is dominant in the production of cellular lactosylceramides, but that inhibition of either enzyme results in increased iNKT cell activation. Additionally, in vivo inhibition of Ugcg by the aminosugar AMP-DNM results in decreased iNKT cell effector function in adipose tissue.Inhibition of endogenous glucosylceramide production results in decreased iNKT cells activity and cytokine production, underscoring the role of this biosynthetic pathway in lipid self-antigen presentation by adipocytes

Prospection of sustainable agrifood systems based on discourse analysis of Curraleiro Pé-Duro cattle breeders in Brazil

ABSTRACT Developing countries face great challenges to couple agricultural intensification and sustainable supply chain development. This paper explores the opportunities for innovation in the conservation of the locally adapted Curraleiro Pé-Duro (CPD) cattle. The CPD is a historical Brazilian breed, related to regional culture, which exhibits remarkable adaptability in tropical biomes. The research method consisted of interviewing and analyzing the discourse of CPD breeders in Tocantins, Brazil. The systematization of the data resulted in four categories and eleven subcategories, which were defined a posteriori. Our findings reveal motivational aspects, potentialities, and prospects for valuation, besides the needs and perceived challenges faced by CPD farmers. A better understanding of the current situation may guide public policies, encourage stakeholders, benefit farmers, and lead to sustainable agri-food initiatives. The empirical contributions of our diagnosis are discussed, and we show how they bring forward and provide valuable lessons to prospect innovations in the conservation of CPD cattle. These findings may support scholars and people who are also interested in accessing and supporting the conservation of indigenous livestock. In general, the study supports the definition of strategies, planning, and investments for the value chain, including the participation of upstream and downstream segments of the farms

Factors of Susceptibility of Human Myiasis Caused by the New World Screw-Worm, Cochliomyia hominivorax in São Gonçalo, Rio de Janeiro, Brazil

This study was carried out between July 2007 and June 2008 and reports on the occurrence of human myiasis caused by the New World screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) in São Gonçalo in the state of Rio de Janeiro, Brazil. Liquid or solid vaseline was used to suffocate the larvae, which were then preserved in 70% ethanol and sent to the Instituto Oswaldo Cruz for identification. C. hominivorax were identified in all 22 cases of myiasis. There were 12 male and 10 female patients with ages ranging from 03 to 71. Ethnically the highest incidence was among black people, with 17 cases. Open wounds were the main cause of the parasitosis, whereas poor personal hygiene, the low educational level, alcoholism, bedridden patients, and physical or mental disability were possibly secondary factors; in addition to all these factors the income of the patients was very low