The species complex Astyanax fasciatus Cuvier (Teleostei, Characiformes) - a multidisciplinary approach

Cytogenetic data have provided important clues that the Astyanax fasciatus populations from the Upper Parana River basin could be a part of a more diverse fish group, usually included on the same taxa. Samples collected in Cachoeira de Emas, SP, in Mogi-Guacu River basin, show two major cytotypes presenting 2n = 46 and 2n = 48 chromosomes, with distinct karyotypic formula, despite the fact that the molecular data suggested some degree of gene flow between these cytotypes. Cytogenetic and morphometric analyses were performed in this species, aiming to contribute to the understanding of the natural history from such fish group. Two allopatric populations with distinct standard cytotypes were analysed, and the data obtained suggest the separation into two groups. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.

Sr-Nd isotopic evidence for crustal contamination in the Niquelandia complex, Goias, Central Brazil

The Niquelandia complex is a Neoproterozoic mafic-ultramafic intrusion resulting from fractional crystallization of primary picritic basalt intrusions. It consists of two layered sequences: a lower and larger one (LS), where four stratigraphic units exhibit an upward decrease of ultramafic layers and increase of gabbroic layers; an upper, smaller sequence (US), separated from LS by a high-temperature shear zone and consisting of two stratigraphic units (gabbros + anorthosites and amphibolites). Nd and Sr isotopic analyses and rare earth element (REE) profiles provide evidence that the complex suffered important crustal contamination. The LS isotopic array trends from a DM region with positive epsilon Nd and moderately positive epsilon Sr towards a field occupied by crustal xenoliths, especially abundant in the upper LS (negative epsilon Nd and large, positive E:Sr). Each LS stratigraphic unit is distinct from the next underlying unit, showing lower epsilon Nd and higher epsilon Sr, suggesting inputs of fresh magma and mixing with the contaminated, residual magma. The US is characterised by a relatively high variation of epsilon Nd and constant epsilon Sr. REE patterns vary within each unit from LREE depleted to LREE enriched in the samples having lower epsilon Nd and higher epsilon Sr. The contamination process has been modelled by using the EC-AFC algorithms from [Spera, F.J., Bohrson, W.A., 2001. Energy-constrained open-system magmatic processes 1: general model and energy-constrained assimilation and fractional crystallization (EC-AFC) formulation. J. Petrology 42, 999-1018]. The differences between the LS and US isotopic arrays are consistent with contamination by the same crustal component, provided that its melting degree was higher in LS than in US. The different degrees of anatexis are explained by the heat budget released from the magma, higher in LS (because of its larger mass) than in US. Comparison of the correlations between isotopes and incompatible trace element ratios of the models and of the gabbros shows some differences, which are demonstrably related with the variable amount of cumulus phases and trapped melt in the gabbros. (c) 2007 Elsevier Ltd. All rights reserved.

U-Pb-Hf-trace element systematics and geochronology of zircon from a granulite-facies metamorphosed mafic-ultramafic layered complex in Central Brazil

Zircon recrystallization is a common process during high-grade metamorphism and promotes partial or complete resetting of the original isotopic and chemical characteristics of the mineral and thus complicates U-Pb geochronological interpretation. In Central Brazil, this complexity may be illustrated by three composite mafic-ultramafic intrusions metamorphosed under amphibolite-to-granulite conditions. Their ages of emplacement and metamorphic ages have been a matter of controversy for the last thirty years. The Serra da Malacacheta and Barro Alto complexes make up the southernmost of these layered bodies and four samples from distinct rock types were investigated in order to verify the consequences of metamorphic alteration of zircon for U-Pb dating. Cathodoluminescent imaging reveals internal features which are typical of concomitant dissolution-reprecipitation processes, such as convolute zoning and inward-moving recrystallization fronts, even in samples in which partially preserved igneous textures are observed. Due to this extensive alteration, LA-ICPMS U-Pb isotopic analysis yielded inconclusive data. However, in situ Hf isotopic and trace-element analyses help to clarify the real meaning of the geochronological data. Low Lu/Hf (<0.004) and homogeneous (176)Hf/(177)Hf(t) values imply that the zircon populations within individual samples have crystallized in a single episode, despite the observed variations in age values. Trace element signatures of zircon grains from garnet-bearing samples reveal that they were unreactive to the development of the peak metamorphism mineral assemblage and, thus, the main chemical feature in such grains is attributed to a coupled dissolution-reprecipitation process. However, in the Cafelandia amphibolite an additional alteration process is identified, probably related to the influx of late-stage fluids. Combined isotopic and geochemical investigation on zircon grains allowed the distinction of two magmatic events. The first corresponds to the crystallization of the Serra da Malacacheta Complex and characterizes a juvenile magmatism at similar to 1.3 Ga. The younger episode, recognized in the Barro Alto Complex, is dated at ca. 800 Ma and is represented by mafic and ultramafic rocks showing intense contamination with continental crust, implying that the emplacement took place, most likely, in a continental back-arc setting. Altered zircon domains as well as titanite grains date the metamorphic event at ca. 760-750 Ma. (C) 2011 Elsevier B.V. All rights reserved.

Dating coeval mafic magmatism and ultrahigh temperature metamorphism in the Anapolis-Itaucu Complex, Central Brazil

Dating granulites has always been of great interest because they represent one of the most extreme settings of an orogen. Owing to the resilience of zircon, even in such severe environments, the link between P-T conditions and geological time is possible. However, a challenge to geochronologists is to define whether the growth of new zircon is related to pre- or post-P-T peak conditions and which processes might affect the (re) crystallization. In this context, the Anapolis-Itaucu Complex, a high-grade complex in central Brazil with ultrahigh temperature (UHT) granulites, may provide valuable information within this topic. The Anapolis-Itaucu Complex (AIC) includes ortho- and paragranulites, locally presenting UHT mineral assemblages, with igneous zircon ages varying between 760 and 650 Ma and metamorphic overgrowths dated at around 650-640 Ma. Also common in the Anapolis-Itaucu Complex are layered mafic-ultramafic complexes metamorphosed under high-grade conditions. This article presents the first geological and geochronological constraints of three of these layered complexes within the AIC, the Damolandia, Taquaral and Goianira-Trindade complexes. U-Pb (LA-MC-ICPMS, SHRIMP and ID-TIMS) zircon analyses reveal a spread of concordant ages spanning within an age interval of similar to 80 Ma with an ""upper"" intercept age of similar to 670 Ma. Under cathodoluminescence imaging, these crystals show partially preserved primary sector zoning, as well as internal textures typical of alteration during high-grade metamorphism, such as inward-moving boundaries. Zircon grains reveal homogeneous initial (176)Hf/(177)Hf values in distinct crystal-scale domains in all samples. Moreover. Hf isotopic ratios show correlation neither with U-Pb ages nor with Th/U ratios, suggesting that zircon grains crystallized during a single growth event. It is suggested, therefore, that the observed spread of concordant U-Pb ages may be related to a memory effect due to coupled dissolution-reprecipitation process during high grade metamorphism. Therefore, understanding the emplacement and metamorphism of this voluminous mafic magmatism is crucial as it may represent an additional heat source for the development of the ultrahigh temperature paragenesis recorded in the paragranulites. (C) 2010 Elsevier B.V. All rights reserved.

Effects of gamma radiation on the photoluminescence properties of polycarbonate matrices doped with terbium complex

Luminescent films containing terbium complex [Tb(acac)(3)(H(2)O)(3)] (acac = acetylacetonate) doped into a polycarbonate (PC) matrix were prepared and irradiated at low-dose gamma radiation with ratio of 5 and 10 kGy. The PC polymer was doped with 5% (w/w) of the Tb(3+) complex. The thermal behavior was investigated by utilization of differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). Changes in thermal stability due to the addition of doping agent into the polycarbonate matrix. Based on the emission spectra of PC:5% Tb(acac)(3) film were observed the characteristic bands arising from the (5)D(4) -> (7)F(J) transitions of Tb(3+) ion (J = 0-6), indicating the ability to obtain the luminescent films. Doped samples irradiated at low dose of gamma irradiation showed a decrease in luminescence intensity with increasing of the dose. (C) 2009 Elsevier Ltd. All rights reserved.

A multicommuted flow-system for spectrophotometric determination of tannin exploiting the Cu(I)/BCA complex formation

A flow system exploiting the multicommutation approach is proposed for spectrophotometric determination of tannin in beverages. The procedure is based on the reduction of Cu(II) in the presence of 4,4`-dicarboxy-2,2`-biquinoline, yielding a complex with maximum absorption at 558 nm. Calibration graph was linear (r=0.999) for tannic acid concentrations up to 5.00 mu mol L-1. The detection limit and coefficient of variation were estimated as 10 nmol L-1 (99.7% confidence level) and 1% (1.78 mu mol L-1 tannic acid, n=10), respectively. The sampling rate was 50 determinations per hour. The proposed procedure is more sensitive and selective than the official Folin-Denis method, also minimizing drastically waste generation. Recoveries within 91.8 and 115% were estimated for total tannin determination in tea and wine samples. (C) 2007 Elsevier B.V. All rights reserved.

Square wave adsorptive cathodic stripping voltarnmetry automated by sequential injection analysis - Potentialities and limitations exemplified by the determination of methyl parathion in water samples

This paper describes the development and evaluation of a sequential injection method to automate the determination of methyl parathion by square wave adsorptive cathodic stripping voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. Accumulation and stripping steps are made in the sample medium conditioned with 40 mmol L-1 Britton-Robinson buffer (pH 10) in 0.25 mol L-1 NaNO3. The homogenized mixture is injected at a flow rate of 10 mu Ls(-1) toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode. After a suitable deposition time, the flow is stopped and the potential is scanned from -0.3 to -1.0 V versus Ag/AgCl at frequency of 250 Hz and pulse height of 25 mV The linear dynamic range is observed for methyl parathion concentrations between 0.010 and 0.50 mgL(-1), with detection and quantification limits of 2 and 7 mu gL(-1), respectively. The sampling throughput is 25 h(-1) if the in line standard addition and sample conditioning protocols are followed, but this frequency can be increased up to 61 h(-1) if the sample is conditioned off-line and quantified using an external calibration curve. The method was applied for determination of methyl parathion in spiked water samples and the accuracy was evaluated either by comparison to high performance liquid chromatography with UV detection, or by the recovery percentages. Although no evidences of statistically significant differences were observed between the expected and obtained concentrations, because of the susceptibility of the method to interference by other pesticides (e.g., parathion, dichlorvos) and natural organic matter (e.g., fulvic and humic acids), isolation of the analyte may be required when more complex sample matrices are encountered. (C) 2007 Elsevier B.V. All rights reserved.

Relative abundance and population biology of the non-indigenous crab Charybdis hellerii (Crustacea: Brachyura: Portunidae) in a southwestern Atlantic estuary-bay complex

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

Elucidating the Evolution of the Red Brocket Deer Mazama americana Complex (Artiodactyla; Cervidae)

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

Induction of apoptosis in A549 pulmonary cells by two Paracoccidioides brasiliensis samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Magnetic interactions and spin-reversal mechanism in ErMn1-xCoxO3-delta samples

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

Taenia saginata: polymerase chain reaction for taeniasis diagnosis in human fecal samples

The taeniasis-cysticercosis complex is a zoonosis of great medical and economic importance where humans play an important role as the carrier of adult stage of Taenia solium and Taenia saginata. This paper describes PCR standardization that can be applied in human fecal samples for taeniasis diagnosis. DNA extraction was achieved with DNAzol reagent, after egg disruption with glass beads. DNA prepared from fecal specimens was first purified and PCR amplified generating fragments of 170 and 600 bp. The assay described herein provides an important tool for T saginata identification in human fecal samples. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Detection of turkey astrovirus in young poults affected with poult enteritis complex in Brazil

Reverse transcription polymerase chain reaction (RT-PCR) of turkey astrovirus (TAstV) capsid and polymerase genes was applied to the bursa of Fabricius (BF), thymus (TH), spleen (SP) and cloacal swabs (CS) of young poults with "Poult enteritis complex" (PEC). The histological lesions included atrophy, lymphoid depletion, cellular infiltration and necrosis of the BF, TH and SP, respectively. The RT-PCR reactions were positive for the polymerase gene of TAstV-2 in all 100 CSs, 7 out of 10 of BFs and 10 out of 20 THs and SPs, respectively. Five out of 10 THs and SPs samples, considered to be negative by RT-PCR, were positive when specific primers designed for the TAstV-2 capsid gene were applied. This is the first description of turkey astrovirus infection presenting PEC in Latin America.

Short-term evaluation of the pulpo-dentin complex response to a resin-modified glass-ionomer cement and a bonding agent applied in deep cavities

Objectives. To evaluate the response of the pulpo-dentin complex following application of a resin-modified glass-ionomer cement or an adhesive system in deep cavities performed in human teeth.Methods. Deep class V cavities were prepared on the buccal surface of 26 premolars. In Group I the cavity walls (dentin) and enamel were conditioned with 32% phosphoric acid and the dentin adhesive system One Step (Bisco, Inc., Itasca, IL, USA) was applied. In Groups 2 and 3, before total etching and application of bonding agent, the cavity floor was lined with the resin-modified glass-ionomer cement-Vitrebond (3M ESPE Dental Products Division, St. Paul, MN, USA) or the calcium hydroxide cement-Dycal (control group, Dentsply, Mildford, DE, USA), respectively. The cavities were restored using light-cured Z-100 composite resin (3M ESPE). The teeth were extracted between 5 and 30 days and prepared for microscopic assessment. Serial sections were stained with H/E, Masson's trichrome, and Brown and Brenn techniques.Results. In Group 1, the inflammatory response was more evident than in Groups 2 and 3. Diffusion of dental material components across dentinal tubules was observed only in Group 1, in which the intensity of the pulp response increased as the remaining dentin thickness decreased. Bacteria were evidenced in the lateral walls of two samples (Group 2) which exhibited no inflammatory response or tissue disorganization.Conclusions. Based on the experimental conditions, it was concluded total acid etching followed by application of One Step bonding agent cannot be recommended as adequate procedures. In this clinical condition the cavity walls should be lined with a biocompatible dental material, such as Vitrebond or Dycal. 2003 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

New species of Moenkhausia Eigenmann, 1903 (Characiformes: Characidae) with comments on the Moenkhausia oligolepis species complex

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