Isotopic evidence for the late Brasiliano (500-550 Ma) ore-forming mineralization of the Araes gold deposit, Brazil

The Araes gold deposit, located in eastern Mato Grosso State, central Brazil, is hosted in Neoproterozoic volcanosedimentary rocks of the Paraguay belt, which formed during collision of the Amazonian craton and the Rio Apa block. Ar-40/Ar-39 geochronology and Pb and S isotopic analyses constrain the timing and sources of mineralization. Three biotite flakes from two samples of metavolcanic host rock yield Ar-40/Ar-39 plateau ages between 5941 and 531 Ma, interpreted as cooling ages following regional metamorphism. Clay minerals from a hydrothermal alteration zone yield an Ar-40/Ar-39 integrated age of 503 +/- 3 Ma. Galena grains from ore-bearing veins yield values of Pb-206/(204)pb from 17.952 to 18.383, Pb-207/Pb-204 from 15.156 to 15.811, and Pb-208/Pb-204 from 38.072 to 39.681. Pyrite grains from ore-bearing veins yield values of Pb-206/Pb-204 from 18.037 to 18.202, Pb-207/Pb-204 from 15.744 to 15.901., and Pb-208/(204)pb from 38.338 to 38.800. Pb isotope variations may be explained in terms of mixing a less radiogenic lead component (mu similar to 8.4) from mafic and ultramafic basement host-rocks (Nova Xavantina metavolcanosedimentary rocks) and a more radiogenic lead component (mu similar to 9.2) probably derived from supracrustal rocks (Cuiaba sedimentary groups). Sulfur isotope compositions are homogeneous, with delta S-34 values ranging from -1.1 parts per thousand to 0.9 parts per thousand (galena) and -0.7 parts per thousand to 0.9 parts per thousand (pyrite), suggesting a mantle-derived reservoir for the mineralizing solutions. Based on the Ar, Pb, and S isotope data, we suggest that the precious metals were remobilized from metavolcanic host rocks by hydrothermal solutions during Brasilide-Panafrican regional metamorphism. The Arabs gold deposit probably formed during a late stage of the orogeny, coeval with other mineralization events in the Paraguay Belt.

500 anos depois

O texto analisa o processo histórico brasileiro procurando explicar a herança sócio-política e cultural excludente, iníqua e antidemocrática do país.

Performance Analysis of MODIS 500-m Spatial Resolution Products for Estimating Chlorophyll-a Concentrations in Oligo-to Meso-Trophic Waters Case Study: Itumbiara Reservoir, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Longitudinal evaluation of fluoride levels in nails of 18-30-month-old children that were using toothpastes with 500 and 1100 mu g F/g

ObjectivesThis study aimed to evaluate the fluoride concentration in the fingernails and toenails of children aged 18-30months during use of fluoride-containing toothpastes supplemented with calcium glycerophosphate (CaGP) or sodium trimetaphosphate (TMP).MethodsAccording to the toothpaste used, children (n=56) were randomly assigned into three groups: 500gF/g with 1% TMP, 500gF/g with 0.25% CaGP, and 1100gF/g. Fingernails and toenails were collected monthly over a period of 330days, from the beginning of toothpaste use. Fluoride concentration in the water consumed by the volunteers and fluoride intake from diet and toothpaste were also determined. Fluoride analyses were performed with the electrode after hexamethyldisiloxane-facilitated diffusion or by the direct method, according to the samples. Data passed normality and homoscedasticity tests and were analyzed by 2-way analysis of variance (anova) and 1-way anova followed by Student-Newman-Keuls test (P<0.05).ResultsFluoride levels in the fingernails and toenails as well as fluoride intake from toothpaste were similar for the groups treated with 500gF/g with 1% TMP and 500gF/g with 0.25% CaGP toothpastes, but significantly lower than the 1100 gF/g group (P<0.05). No significant differences were noted among the groups regarding fluoride intake from diet and that by water consumed by the volunteers (P>0.05).ConclusionThe results of the longitudinal study suggest that the level of fluoride present in nails was lower with the use of toothpastes with a low fluoride concentration.

Anotação de 500 ESTs da saúva Atta laevigata

Leaf-cutting ants belonging to the genus Atta occur from the tropical to subtropical regions of the Americas. These insects are considered pests because they cause serious damage in agricultural areas. Among these, stands out Atta laevigata, species which the colony requires a huge amount of leaves to grow its symbiotic fungus which is the main food source of the nest. Thus, the study of the transcriptome of these ants becomes a useful tool, because it is possible to identify proteins potentially involved with their skills as insect pests and also those related to differences between the varieties present in the nests. In the present study we described results of the partial analysis of the transcriptome of the leaf-cutting ant pest A. laevigata, from cDNA sequences previously generated in the Laboratory of Evolution and Molecular (LEM). The results may also be used for molecular, ecological, metabolic and evolutionary studies about ants, and heterologous expression of important proteins as molecular targets for the control of some leafcutting agricultural pests.

Oferta educacional em creches: análise das parcerias público-privadas nos municípios paulistas com mais de 500.000 habitantes

Este trabalho tem por tema os contornos institucionais gerados nas parcerias entre os setores público e privado na oferta educacional em creches nos municípios paulistas com mais de 500.000 habitantes, classificados como muito grandes e metropolitanos no Censo de 2000. Para isto, fez-se necessário identificar, caracterizar e analisar os contornos que vêm sendo gerados a partir dos convênios firmados entre o Poder Público Municipal e instituições privadas para oferta educacional em creches. O período considerado para o presente estudo foi entre 2000 e 2009. O início do período em 2000 se justifica pelo prazo final estabelecido pela LDB 9394/96, para integração das creches aos respectivos sistemas de ensino ser dezembro de 1999. Já o término do período em 2009 possibilita identificar alterações nas matrículas em creches após a instituição do FUNDEB. Assim, utilizamos como procedimento teórico-metodológico o levantamento e análise bibliográfica, contatos telefônicos diretos com os gestores municipais para coletar informações sobre as parcerias, dados disponibilizados no Banco de Dados do Grupo de Estudos e Pesquisas em Política Educacional (Greppe), sites oficiais dos municípios e sites governamentais. Constitui-se, este trabalho, como parte integrante da pesquisa “Oferta Educacional nas creches: Arranjos Institucionais entre o Público e o Privado” financiada pelo CNPq e coordenada pela Profª Drª Raquel Fontes Borghi. O estudo realizado nos permitiu identificar e analisar diferentes arranjos institucionais gerados entre o Poder Público Municipal com instituições privadas. Também, permitiu observar, que após a implantação do FUNDEB, a tendência nas matrículas é de crescimento nas creches, tanto na rede pública quanto na rede privada, e nas préescolas da rede privada. Já nas pré-escolas municipais a tendência é de oscilação nas matrículas

Oferta educacional nas creches e parcerias público-privado nos municípios paulistas de 100.000 a 500.000 habitantes

Este trabalho, financiado pela Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), identifica, caracteriza e analisa, no conjunto dos municípios paulistas de 100.000 a 500.000 habitantes, os diferentes arranjos institucionais firmados entre o Poder Público Municipal e instituições privadas para a oferta educacional em creches, bem como verificar as implicações do FUNDEB - Fundo de Manutenção e Desenvolvimento da Educação Básica e de Valorização dos Profissionais da Educação - na performance das matrículas na educação infantil da rede pública e privada. O período considerado para o presente estudo foi entre 2000 e 2009. O início do período em 2000 se justifica pelo prazo final estabelecido pela LDB 9394/96 para integração das creches aos respectivos sistemas de ensino ser dezembro de 1999. Já o término do período em 2009 possibilita identificar alterações nas matrículas em creches após a instituição do FUNDEB. Desta forma utilizamos como procedimento teórico-metodológico o levantamento e análise bibliográfica, contatos telefônicos diretos com os gestores municipais para coletar informações sobre as parcerias, dados disponibilizados no Banco de Dados do Grupo de Estudos e Pesquisas em Política Educacional (GREPPE), sites oficiais dos municípios e sites governamentais. Constitui-se este trabalho como parte integrante da pesquisa “Oferta Educacional nas creches: Arranjos Institucionais entre o Público e o Privado” financiada pelo CNPq e coordenada pela Profª Drª Raquel Fontes Borghi. O estudo realizado nos permitiu observar diferentes arranjos institucionais entre o Poder Público Municipal com instituições privadas, sendo visível a expansão de parcerias com instituições privadas com fins lucrativos... (Resumo completo, clicar acesso eletrônico abaixo)

Susceptibility of Rhipicephalus (Boophilus) microplus to ivermectin (200, 500 and 630 mu g/kg) in field studies in Brazil

The present study aimed to determine the susceptibility of 17 Rhipicephalus (Boophilus) microplus populations, originating in the Southeast and Southern regions of Brazil, to different ivermectin concentrations (200, 500 and 630 mu g/kg), administered through subcutaneous or topical (pour-on) routes. R. (B.) microplus populations from the states of Minas Gerais (seven populations), Sao Paulo (seven populations) and Parana (three populations) were chosen for the tests. The selected cattle were allocated to treatment groups on day 0, and block formation was based on the arithmetic mean of female ticks (4.5-8.0 mm long) counted on three consecutive days (-3, -2 and -1). To evaluate the therapeutic and residual efficacies of these formulations, tick counts (females ranging from 4.5 to 8.0 mm long) were performed on days 3,7 and 14 post-treatment, and continued on a weekly basis thereafter until the end of each experiment. The results obtained throughout this study, utilizing field efficacy studies, allowed us to conclude that the resistance of R. (B.) microplus against 200 and 500 mu g/kg ivermectin is widely disseminated because all tick populations that had contact with these specific concentrations were diagnosed as resistant. However, it is possible to infer that R. (B.) microplus resistance against 630 mu g/kg ivermectin was also widespread, diagnosed at six of ten analyzed properties. Resistance of these ectoparasites to 630 mu g/kg ivermectin is most likely emerging in three other populations of R. (B.) microplus. Strategies of resistance management need to be quickly determined to keep the selection pressure at a minimum level in Brazil. (C) 2014 Elsevier B.V. All rights reserved.