1,258 research outputs found
Standby power consumption estimation by interacting leakage current mechanisms in nanoscaled CMOS digital circuits
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U-Pb (Zircon) ages of metavolcanic rocks from the Itaiacoca Group: tectonic implications
The main aim of this work is to present and discuss the U-Pb ages obtained for zircon grains from metavolcanic rocks of the Itaiacoca Group. The Itaiacoca Group is a metavolcano-sedimentary sequence, which occurs as a narrow belt between the Cunhaporanga granitic batholith to the northwest and the Itapirapuã shear zone to the south and southwest, which separates the sequence from the Três Córregos granite batholith and metasedimentary rocks of the Açungui Group. Geological studies of the southern part of the Itaiacoca belt led to the recognition of three units, represented (from base to top) by metawackes with an important volcanic component, metacarbonate, and metapelitic and metapsammitic rocks. The U-Pb geochronological analyses of zircon grains from two outcrops of metavolcanic rocks yield ages of 628 ± 18 Ma (SHRIMP) and 636 ± 30 Ma (conventional multi-grain analyses). These ages are quite close to the metamorphic event recorded in the Itaiacoca Group (628 - 610 Ma), suggesting a short interval between the formation of these rocks and closure of the basin. Furthermore, this volcanism is very close to the age of formation of the Três Córregos (630 Ma) and Cunhaporanga (590 Ma) granitic batholiths, admitted as associated with a probable magmatic arc. Such an isotopic pattern characterizes a Neoproterozoic tectonic scenario involving volcanism, metamorphism and granitic plutonism, interpreted here as the final stages in the evolution of the Itaiacoca Basin.O objetivo principal deste trabalho é apresentar e discutir as idades geocronológicas U-Pb, em zircões de rochas metavulcânicas pertencentes ao Grupo Itaiacoca. Este é representado por uma seqüência metavulcano-sedimentar, que ocorre como uma faixa relativamente estreita, limitada a norte pelo Batólito Granítico Cunhaporanga, sendo balizada a sul, através da Zona de Cisalhamento Itapirapuã, pelo Batólito Granítico Três Córregos e pelos metassedimentos do Grupo Açungui. Os estudos geológicos efetuados na porção sul da Faixa Itaiacoca permitiram reconhecer três unidades geológicas maiores, representadas, da base para o topo, por metarcóseos (com importante contribuição vulcânica-vulcanoclástica), rochas metacarbonáticas e rochas metapelíticas-metapsamíticas. Análises geocronológicas U-Pb realizadas em zircões de dois afloramentos de rochas metavulcânicas, forneceram idades de 628 ± 18 Ma (SHRIMP) e 636 ± 30 Ma (convencional). O metamorfismo dessas rochas parece ter ocorrido em épocas bastante próximas (628 - 610 Ma) à cristalização dos zircões, sugerindo curto intervalo de tempo entre o vulcanismo estudado e os episódios de fechamento da bacia. Não obstante, as idades obtidas também se aproximam da época de formação dos batólitos graníticos Três Córregos (630 Ma) e Cunhaporanga (590 Ma), admitidos como prováveis arcos magmáticos. Tal padrão isotópico caracteriza um cenário tectônico Neoproterozóico envolvendo vulcanismo, metamorfismo e plutonismo granítico, interpretados como relativos aos estágios finais da evolução da Bacia Itaiacoca
Gas Gain Uniformity Tests performed on Multi Wire Proportional Chambers for the LHCb Muon System
We present the experimental setup and the results of the gas gain uniformity tests performed as part of the quality control of the multiwire proportional chambers produced at CERN for the LHCb Muon system. The test provides a relative gas gain measurement over the whole chamber sensitive area. It is based on the analysis of the pulse height spectrum obtained when the chamber is exposed to {a^241}Am radioactive source. Since the measurement is normalized to the peak of a precise pulse generator, the gain uniformity can also be evaluated among different gas gaps and different chambers
Cerebrospinal fluid syndromes in HIV-positive patients with acute consciousness compromise
Analysis of reliability, accuracy, sensitivity and predictive value of a subjective method to classify facial pattern in adults
Qualidade do sistema de informação do câncer do colo do útero no estado do Rio de Janeiro
Automated array-CGH optimized for archival formalin-fixed, paraffin-embedded tumor material
BACKGROUND: Array Comparative Genomic Hybridization (aCGH) is a rapidly evolving technology that still lacks complete standardization. Yet, it is of great importance to obtain robust and reproducible data to enable meaningful multiple hybridization comparisons. Special difficulties arise when aCGH is performed on archival formalin-fixed, paraffin-embedded (FFPE) tissue due to its variable DNA quality. Recently, we have developed an effective DNA quality test that predicts suitability of archival samples for BAC aCGH. METHODS: In this report, we first used DNA from a cancer cell-line (SKBR3) to optimize the aCGH protocol for automated hybridization, and subsequently optimized and validated the procedure for FFPE breast cancer samples. We aimed for highest throughput, accuracy, and reproducibility applicable to FFPE samples, which can also be important in future diagnostic use. RESULTS: Our protocol of automated array-CGH on archival FFPE ULS-labeled DNA showed very similar results compared with published data and our previous manual hybridization method. CONCLUSION: This report combines automated aCGH on unamplified archival FFPE DNA using non-enzymatic ULS labeling, and describes an optimized protocol for this combination resulting in improved quality and reproducibility
Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements
Bryozoans are Major Modern Builders of South Atlantic Oddly Shaped Reefs
Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-27961-6.In major modern reef regions, either in the Indo-Pacific or the Caribbean, scleractinian corals are
described as the main reef framework builders, often associated with crustose coralline algae. We
used underwater cores to investigate Late Holocene reef growth and characterise the main framework
builders in the Abrolhos Shelf, the largest and richest modern tropical reef complex in the South
Western Atlantic, a scientifically underexplored reef province. Rather than a typical coralgal reef,
our results show a complex framework building system dominated by bryozoans. Bryozoans were
major components in all cores and age intervals (2,000 yrs BP), accounting for up to 44% of the reef
framework, while crustose coralline algae and coral accounted for less than 28 and 23%, respectively.
Reef accretion rates varied from 2.7 to 0.9 mm yr−1, which are similar to typical coralgal reefs.
Bryozoan functional groups encompassed 20 taxa and Celleporaria atlantica (Busk, 1884) dominated
the framework at all cores. While the prevalent mesotrophic conditions may have driven suspensionfeeders’
dominance over photoautotrophs and mixotrophs, we propose that a combination of historical
factors with the low storm-disturbance regime of the tropical South Atlantic also contributed to the
region’s low diversity, and underlies the unique mushroom shape of the Abrolhos pinnacles.We thank CNPq/FAPES-Sisbiota/PELD, CAPES/IODP, CAPES/Ciências do Mar, and ANP/Brasoil for long
term project funding. We also thank ICMBio for research permits and field logistic support, and Conservation
International for providing and authorizing the use of the IKONOS image. JMW and JCB are International
Visiting Researcher at UFES and JBRJ, supported by the Science Without Borders program. Zá Cajueiro
provided invaluable field support and Ronaldo Francini, Carlos Janovitch and Lucio Engler helped in the drilling
operations. This is a contribution from the Rede Abrolhos (abrolhos.org)
Basal keratin expression in breast cancer by quantification of mRNA and by immunohistochemistry
Definitions of basal-like breast cancer phenotype vary, and microarray-based expression profiling analysis remains the gold standard for the identification of these tumors. Immunohistochemical identification of basal-like carcinomas is hindered with a fact, that on microarray level not all of them express basal-type cytokeratin 5/6, 14 and 17. We compared expression of cytokeratin 5, 14 and 17 in 115 patients with operable breast cancer estimated by real-time RT-PCR and immunohistochemistry
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