ASSOCIATED A-TYPE SUBALKALINE AND HIGH-K CALC-ALKALINE GRANITES IN THE ITU GRANITE PROVINCE, SOUTHEASTERN BRAZIL: PETROLOGICAL AND TECTONIC SIGNIFICANCE

The 590-580 Ma Itu Granite Province (IGP) is a roughly linear belt of post-orogenic granite plutons similar to 60 km wide extending for some 350 km along the southern edge of the Apia-Guaxupe Terrane in southeastern Brazil. Typical components are subalkaline A-type granites (some with rapakivi texture) that crystallized at varied, but mostly strongly oxidizing conditions, and contrast with a coeval association of also oxidized high-K calc-alkaline granites in terms of major (e. g., lower Ca/Fe) and trace elements (higher Nb, Y, Zr). Mantle-derived magmas (such as those forming the LILE-rich Piracaia Monzodiorite, with epsilon(Nd(t)) = -7 to -10, (87)Sr/(86)Sr((t)) = 0.7045-0.7055) are inferred to derive from enriched subcontinental lithosphere modified during previous subduction, and may have played a role in the generation of the A-type granites, adding melts or fluids or both to the lower crust from which the latter were generated. The IGP is interpreted as a reflection of crust uplift and increased heat flux during ascent of hot, less dense asthenosphere after continental collision, probably reflecting breakoff of an oceanic slab coeval to the right-lateral accretion of a terrane related to the Mantiqueira Orogenic System.

Major- and trace-element composition of REE-rich turkestanite from peralkaline granites of the Morro Redondo Complex, Graciosa Province, south Brazil

Turkestanite, a rare Th- and REE-bearing cyclosilicate in the ekanite-steacyite group was found in evolved peralkaline granites from the Morro Redondo Complex, south Brazil. It occurs with quartz, alkali feldspar and an unnamed Y-bearing silicate. Electron microprobe analysis indicates relatively homogeneous compositions with maximum ThO(2), Na(2)O and K(2)O contents of 22.4%, 2.93% and 3.15 wt.%, respectively, and significant REE(2)O(3) abundances (5.21 to 11.04 wt.%). The REE patterns show enrichment of LREE over HREE, a strong negative Eu anomaly and positive Ce anomaly, the latter in the most transformed crystals. Laser ablation inductively coupled plasma mass spectrometry trace element patterns display considerable depletions in Nb, Zr, Hf, Ti and Li relative to whole-rock sample compositions. Observed compositional variations suggest the influence of coupled substitution mechanisms involving steacyite, a Na-dominant analogue of turkestanite, iraqite, a REE-bearing end-member in the ekanite-steacyite group, ekanite and some theoretical end-members. Turkestanite crystals were interpreted as having precipitated during post-magmatic stages in the presence of residual HFSE-rich fluids carrying Ca, the circulation of which was enhanced by deformational events.

Transpressive dextral shear in the Italva-Itaperuna section, Northern State of Rio de Janeiro, Brazil

Structural analysis carried out on a segment of the Neoproterozoic Ribeira Belt, southeastern Brazil, show that it represents part of the transpressive dextral orogen related to the Central Mantiqueira Province. NNE-trending and steeply dipping regional mylonitic belts form anastomosed geometry, and describe a map-scale, S-C-like structure that is characterized by their deflection towards NE near the Além Paraíba Lineament. Lithological and structural control related to deformation partition were responsible for the formation of felsic mylonitic granulites with S-type granites lenses developed in ductile shear zones, alternated with less deformed intermediate to basic granulites associated with charnockites. The dextral shear sense indicators are consistent with transpressive deformation in the region and are common especially at the border of the main shear zones. The presence of S-type leucogranite may lead to variations of linear and planar relationships, which result in local extension zones. These elements are consistent with oblique continental collision considering the São Francisco Craton as a stable block.

Petrogenesis of Upper Paleozoic post-collisional peraluminous leucogranites, Sierra de Ancasti, northwest Argentina

The Santa Rosa and Sauce Guacho plutons are two post-collisional peraluminous Late Devonian to Early Carboniferous leucogranites that intruded the banded schists of the Ancasti Formation. The leucogranites are composed of microcline phenocrysts along with quartz, plagioclase, muscovite, biotite, ilmenite, tourmaline, apatite, monazite and zircon. Their geochemical composition is consistent with S-type granites and mineralogically they belong to MPG granites (muscovite-peraluminous granites). It is proposed that granite magma generation was related to shear zones that concentrated fluids in the metasedimentary crust during a collision or transcurrent tectonics. U-Pb analyses on monazite gave an age of 369.8 +/- 5.3 Ma, while Sm/Nd isotopic data yield epsilon(Nd(t)) values of -5.3 for Sauce Guacho and -5.7 for Santa Rosa indicating crustal provenance. Nd model ages between 1,544 and 1,571 Ma are within the range of magmatic rocks from the Lower Ordovician Famatinian Arc in the Central Sierras Pampeanas.

A review of the tectonic evolution of the Sunsas belt, SW Amazonian Craton

The Sunsas-Aguapei province (1.20-0.95 Ga), SW Amazonian Craton, is a key area to study the heterogeneous effects of collisional events with Laurentia, which shows evidence of the Grenvillian and Sunsas orogens. The Sunsas orogen, characterized by an allochthonous collisional-type belt (1.11-1.00 Ga), is the youngest and southwestern most of the events recorded along the cratonic fringe. Its evolution occurred after a period of long quiescence and erosion of the already cratonized provinces (>1.30 Ga), that led to sedimentation of the Sunsas and Vibosi groups in a passive margin setting. The passive margin stage was roughly contemporary with intraplate tectonics that produced the Nova Brasilandia proto-oceanic basin (<1.21 Ga), the reactivation of the Ji-Parana shear zone network (1.18-1.12 Ga) and a system of aborted rifts that evolved to the Huanchaca-Aguapei basin (1.17-1.15 Ga). The Sunsas belt is comprised by the metamorphosed Sunsas and Vibosi sequences, the Rincon del Tigre mafic-ultramafic sill and granitic intrusive suites. The latter rocks yield epsilon(Nd(t)) signatures (-0.5 to -4.5) and geochemistry (S,1, A-types) suggesting their origin associated with a continental arc setting. The Sunsas belt evolution is marked by ""tectonic fronts"" with sinistral offsets that was active from c. 1.08 to 1.05 Ga, along the southern edge of the Paragua microcontinent where K/Ar ages (1.27-1.34 Ga) and the Huanchaca-Aguapei flat-lying cover attest to the earliest tectonic stability at the time of the orogen. The Sunsas dynamics is coeval with inboard crustal shortening, transpression and magmatism in the Nova Brasilandia belt (1.13-1.00 Ga). Conversely, the Aguapei aulacogen (0.96-0.91 Ga) and nearby shear zones (0.93-0.91 Ga) are the late tectonic offshoots over the cratonic margin. The post-tectonic to anorogenic stages took place after ca. 1.00 Ga, evidenced by the occurrences of intra-plate A-type granites, pegmatites, mafic dikes and sills, as well as of graben basins. Integrated interpretation of the available data related to the Sunsas orogen supports the idea that the main nucleus of Rodinia incorporated the terrains forming the SW corner of Amazonia and most of the Grenvillian margin, as a result of two independent collisional events, as indicated in the Amazon region by the Ji-Parana shear zone event and the Sunsas belt, respectively. (C) 2009 Elsevier Ltd. All rights reserved.

Precambrian geotectonic units of the Rio de La Plata craton

The main Precambrian tectonic units of Uruguay include the Piedra Alta tectonostratigraphic terrane (PATT) and Nico Perez tectonostratigraphic terrane (NPTT), separated by the Sarandi del Yi high-strain zone. Both terranes are well exposed in the Rio de La Plata craton (RPC). Although these tectonic units are geographically small, they record a wide span of geologic time. Therefore improved geological knowledge of this area provides a fuller understanding of the evolution of the core of South America. The PATT is constituted by low-to medium-grade metamorphic belts (ca. 2.1 Ga); its petrotectonic associations such as metavolcanic units, conglomerates, banded iron formations, and turbiditic deposits suggest a back-arc or a trench-basin setting. Also in the PATT, a late to post-orogenic, arc-related layered mafic complex (2.3-1.9 Ga), followed by A-type granites (2.08 Ga), and finally a taphrogenic mafic dike swarm (1.78 Ga) occur. The less thoroughly studied NPTT consists of Palaeoproterozoic high-grade metamorphic sequences (ca. 2.2 Ga), mylonites and postorogenic and rapakivi granites (1.75 Ga). The Brasiliano-Pan African orogeny affected this terrane. Neoproterozoic cover occurs in both tectonostratigraphic terranes, but is more developed in the NPTT. Over the past 15 years, new isotopic studies have improved our recognition of different tectonic events and associated processes, such as reactivation of shear zones and fluids circulation. Transamazonian and Statherian tectonic events were recognized in the RPC. Based on magmatism, deformation, basin development and metamorphism, we propose a scheme for the Precambrian tectonic evolution of Uruguay, which is summarized in the first Palaeoproterozoic tectonic map of the Rio de La Plata craton.

Effect of cement type and water storage time on the push-out bond strength of a glass fiber post

This study investigated the effects of the cement type and the water storage time on the push-out bond strength of a glass fiber post. Glass fiber posts (Fibrekor, Jeneric Pentron) were luted to post spaces using a self-cured resin cement (C&B Cement [CB]), a glass ionomer cement (Ketac Cem [KC]) or a resin-modified glass ionomer cement (GC FujiCEM [FC]) according to the manufacturers’ instructions. For each luting agent, the specimens were exposed to one of the following water storage times (n=5): 1 day (T1), 7 days (T7), 90 days (T90) and 180 days (T180). Push-out tests were performed after the storage times. Control specimens were not exposed to water storage, but subjected to the push-out test 10 min after post cementation. Data (in MPa) were analyzed by Kruskal-Wallis and Dunn`s test (α=0.05). Cement type and water storage time had a significant effect (p<0.05) on the push-out bond strength. CB showed significantly higher values of retention (p<0.05) than KC and FC, irrespective of the water storage time. Water storage increased significantly the push-out bond strength in T7 and T90, regardless of the cement type (p<0.05). The results showed that fiber posts luted to post spaces with the self-cured resin cement exhibited the best bonding performance throughout the 180-day water storage period. All cements exhibited a tendency to increase the bond strength after 7 and 90 days of water storage, decreasing thereafter.

In vitro analysis of thermocompaction time and gutta-percha type on quality of main canal and lateral canals filling

The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling).

Minas-type fresh cheese developed from buffalo milk with addition of L. acidophilus

Effective incorporation of a probiotic into foods requires the culture to remain viable all along processing and storage, without adverse alterations to sensory characteristics. The objective of this work was developing Minas-type fresh cheese with probiotic properties from buffalo milk. Four batches of Minas-type fresh cheese were prepared using buffalo milk: batch T1 in which neither culture nor lactic acid added; batch T3 in which only lactic acid added; batches T2 and T4 , both added of Lactobacillus acidophilus LAC 4, but T4 was also acidified. Resulting cheeses were evaluated for probiotic culture stability, texture profile, sensory acceptance, and changes in pH. The T4 probiotic cheese presented hardness, gumminess, and chewiness significantly lower than the other treatments. However, values for springiness and cohesiveness did not differ between all cheeses, and no sensory differences (p > 0.05) were found between treatments for texture, taste, and overall acceptance. The addition of probiotic to the acidified cheese (T4) yielded best aroma. The populations of L. acidophilus were greater than 10(6) CFU g-1 after 28 days of storage all products. Minas-type fresh cheese from buffalo milk is a suitable food for the delivery of L. acidophilus, since the culture remained viable during the shelf life of the products and did not negative affect analysed parameters.

Association of polymorphisms at the ADIPOR1 regulatory region with type 2 diabetes and body mass index in a Brazilian population with European or African ancestry

Association studies between ADIPOR1 genetic variants and predisposition to type 2 diabetes (DM2) have provided contradictory results. We determined if two single nucleotide polymorphisms (SNP c.-8503G>A and SNP c.10225C>G) in regulatory regions of ADIPOR1 in 567 Brazilian individuals of European (EA; N = 443) or African (AfA; N = 124) ancestry from rural (quilombo remnants; N = 439) and urban (N = 567) areas. We detected a significant effect of ethnicity on the distribution of the allelic frequencies of both SNPs in these populations (EA: -8503A = 0.27; AfA: -8503A = 0.16; P = 0.001 and EA: 10225G = 0.35; AfA: 10225G = 0.51; P < 0.001). Neither of the polymorphisms were associated with DM2 in the case-control study in EA (SNP c.-8503G>A: DM2 group -8503A = 0.26; control group -8503A = 0.30; P = 0.14/SNP 10225C>G: DM2 group 10225G = 0.37; control group 10225G = 0.32; P = 0.40) and AfA populations (SNP c.-8503G>A: DM2 group -8503A = 0.16; control group -8503A = 0.15; P = 0.34/SNP 10225C>G: DM2 group 10225G = 0.51; control group 10225G = 0.52; P = 0.50). Similarly, none of the polymorphisms were associated with metabolic/anthropometric risk factors for DM2 in any of the three populations, except for HDL cholesterol, which was significantly higher in AfA heterozygotes (GC = 53.75 ± 17.26 mg/dL) than in homozygotes. We conclude that ADIPOR1 polymorphisms are unlikely to be major risk factors for DM2 or for metabolic/anthropometric measurements that represent risk factors for DM2 in populations of European and African ancestries.

COL18A1 is highly expressed during human adipocyte differentiation and the SNP c.1136C > T in its "frizzled" motif is associated with obesity in diabetes type 2 patients

Collagen XVIII can generate two fragments, NC11-728 containing a frizzled motif which possibly acts in Wnt signaling and Endostatin, which is cleaved from the NC1 and is a potent inhibitor of angiogenesis. Collagen XVIII and Wnt signaling have recently been associated with adipogenic differentiation and obesity in some animal models, but not in humans. In the present report, we have shown that COL18A1 expression increases during human adipogenic differentiation. We also tested if polymorphisms in the Frizzled (c.1136C>T; Thr379Met) and Endostatin (c.4349G>A; Asp1437Asn) regions contribute towards susceptibility to obesity in patients with type 2 diabetes (113 obese, BMI =30; 232 non-obese, BMI < 30) of European ancestry. No evidence of association was observed between the allele c.4349G>A and obesity, but we observed a significantly higher frequency of homozygotes c.1136TT in obese (19.5%) than in non-obese individuals (10.9%) [P = 0.02; OR = 2.0 (95%CI: 1.07-3.73)], suggesting that the allele c.1136T is associated to obesity in a recessive model. This genotype, after controlling for cholesterol, LDL cholesterol, and triglycerides, was independently associated with obesity (P = 0.048), and increases the chance of obesity in 2.8 times. Therefore, our data suggest the involvement of collagen XVIII in human adipogenesis and susceptibility to obesity.

Catalogue of " poneromorph" ant type specimens (Hymenoptera, Formicidae) deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil

The present catalogue lists the type specimes of 112 nominal " poneromorph" ant species housed in the Formicidae collection of the Hymenoptera laboratory, Museu de Zoologia da Universidade de São Paulo (MZSP). The catalogue includes types of Amblyoponinae, Ectatomminae, Heteroponerinae, Ponerinae, and Proceratiinae, that is, all poneromorph (sensu Bolton, 2003) but for the monotypic Paraponerinae, of which the collection bears no type specimens. We present here information on type categories (holotype, paratype, syntype, lectotype, and paralectotype), label data, nomenclatural changes since the original description and type specimens conservation status. At last we present indexes for the taxa names presented.

Gas-phase solvolysis type reactions of SiCl3+ cations

Gas-phase SiCl3+ ions undergo sequential solvolysis type reactions with water, methanol, ammonia, methylamine and propylene. Studies carried out in a Fourier Transform mass spectrometer reveal that these reactions are facile at 10-8 Torr and give rise to substituted chlorosilyl cations. Ab initio and DFT calculations reveal that these reactions proceed by addition of the silyl cation to the oxygen or nitrogen lone pair followed by a 1,3-H migration in the transition state. These transition states are calculated to lie below the energy of the reactants. By comparison, hydrolysis of gaseous CCl3+ is calculated to involve a substantial positive energy barrier.

The type specimens of "dorylomorph" ants (Hymenoptera, Formicidae: Aenictinae, Ecitoninae, Cerapachyinae, Leptanilloidinae) deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil

The present catalogue lists the "dorylomorph" ant types (Aenictinae: Aenictus; Cerapachyinae: Acanthostichus and Cerapachys; Ecitoninae: Eciton, Labidus, Neivamyrmex and Nomamyrmex; and Leptanilloidinae: Asphinctanilloides and Leptanilloides) housed in the Formicidae collection of the Hymenoptera laboratory, Museu de Zoologia da Universidade de São Paulo (MZSP), Brazil. In total, the collection includes types of 141 nominal species, of which 56 are still valid. The majority of types of dorylomorph species in the MZSP collection are syntypes (67 species), but there are as well 13 species represented by holotypes only, 17 by holotypes and paratypes, 43 species by paratypes only, and one species by a paralectotype. We record the label information, condition of the specimens, nomenclatural changes, type status, and provide indexes of the listed taxa.

A catalogue of the Pseudomyrmecinae ants type specimens (Hymenoptera, Formicidae) deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil

This catalogue lists the type specimens of 37 species of Pseudomyrmecinae ants deposited in the Hymenoptera Formicidae collection of the Museu de Zoologia da Universidade de São Paulo, which holds types of the only two genera that occur in the Neotropics, Pseudomyrmex Lund and Myrcidris Ward. We record the label information, condition of the specimens, nomenclatural changes, type status, and provide an index of the listed taxa.