Cambrian mafic to felsic magmatism and its connections with transcurrent shear zones of the Borborema Province (NE Brazil): Implications for the late assembly of the West Gondwana

New U-Pb (SHRIMP) and (40)Ar/(39)Ar isotopic data of igneous rocks and mylonites of the Borborema Province (NE Brazil) show that a wide range of tectonothermal events affected the province during the transition from the Precambrian to the Cambrian. Concordant zircon U-Pb data constrained the crystallization age of mafic stocks, mafic to felsic dikes and granite batholiths between 548 and 533 Ma. These bodies were emplaced in a regional strain field combining extension and dextral shearing. The ductile shear deformation overprinted an older basement fabric to develop a low- to medium metamorphic grade vertical mylonite belt that cut the province in the E-W direction. Magnetic fabrics of the Cambrian batholiths determined by anisotropy of magnetic susceptibility are consistent with syntectonic emplacement. The magmatic pulses and shear deformation would have supplied enough heat to reset the synkinematic micas of mylonites to yield (40)Ar/(39)Ar plateau cooling ages between ca. 550 and 510 Ma. These results provide evidence that emplacement of Early Cambrian mafic and felsic magmas were accompanied by regional-scale shear deformations, probably in the consequence of late collisions along the West Gondwana margin. (C) 2010 Published by Elsevier B.V.

Relics of eclogite facies assemblages in the Ceara Central Domain, NW Borborema Province, NE Brazil: Implications for the assembly of West Gondwana

The Borborema Province, in the NE of Brazil, is a rather complex piece in the Brazil-Africa puzzle as it represents the junction of the Dahomeyide/Pharusian, Central African, Aracuai and Brasilia fold belts located between the West-African/Sao Luis, Congo/Sao Francisco and Amazonas craton. The correlation between the Dahomeyides from W-Africa (Ghana, Benin, Togo, and Mali) and the Borborema Province involves the Medio Coreau and Central Ceara domains. The inferred continuation of the main oceanic suture zone exposed in the Dahomeyides of W Africa is buried beneath the Phanerozoic Parnaiba Basin in Brazil (northwest of the Medio Coreau domain) where some high density gravity anomalies may represent hidden remnants of an oceanic suture. In addition to this major suture a narrow, nearly continuous strip composed of mainly mafic pods containing relics of eclogite-facies assemblages associated with partially migmatized granulite-facies metapelitic gneisses has been found further east in the NW Borborema Province. These high pressure mafic rocks, interpreted as retrograded eclogites, are located between the Transbrasiliano Lineament and the Santa Quiteria continental arc and comprise primitive to evolved arc-related rocks with either arc- or MORB-type imprints that can indicate either deep subduction of oceanic lithosphere or roots of continental and oceanic magmatic arcs. Average peak P-T conditions under eclogite-facies metamorphism (T=770 degrees C and P = 17.3 kbar) were estimated using garnet-clinopyroxene thermometry and Jd content in clinopyroxene. Transition to granulite-facies conditions, as well as later widespread re-equilibration under amphibolite facies, were registered both in the basic and the metapelitic rocks and suggest a clockwise P-T path characterized by an increase in temperature followed by strong decompression. A phenomenon possibly related to the exhumation of a highly thickened crust associated with the suturing of the Medio Coreau and Central Ceara domains, two distinct crustal blocks separated by the Transbrasiliano Lineament. (C) 2009 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Protein Assembly onto Cationic Supported Bilayers

Cationic supported bilayers on latex are useful to isolate and immobilize oppositely charged proteins as a monomolecular layer over a range of low protein concentrations and particle number densities. Cholera toxin (CT) from Vibrio cholerae, an 87 kDa AB(5) hexameric protein and bovine serum albumin (BSA) self-assembled on dioctadecyldimethylammonium bromide (DODAB) supported bilayers with high affinity yielding highly organized and monodisperse particulates at 5 x 10(9) particles/mL, over a range of low protein concentrations (0-0.025 mg/mL BSA or CT). Protein association onto the bilayer-covered polystyrene sulfate (PSS) was determined from adsorption isotherms, dynamic light scattering for size distributions and zeta-potential analysis revealing a monomolecular, thin and highly organized protein layer surrounding each particle with potential for biospecific recognition such as antigen-antibody, receptor-ligand, hybridization of oligonucleotide sequences, all of them important in immunodiagnosis, selective biomolecular chromatographic separations, microarrays design and others.

Superoxide Dismutase 1-mediated Production of Ethanol- and DNA-derived Radicals in Yeasts Challenged with Hydrogen Peroxide MOLECULAR INSIGHTS INTO THE GENOME INSTABILITY OF PEROXIREDOXIN-NULL STRAINS

Peroxiredoxins are receiving increasing attention as defenders against oxidative damage and sensors of hydrogen peroxide-mediated signaling events. In the yeast Saccharomyces cerevisiae, deletion of one or more isoforms of the peroxiredoxins is not lethal but compromises genome stability by mechanisms that remain under scrutiny. Here, we show that cytosolic peroxiredoxin-null cells (tsa1 Delta tsa2 Delta) are more resistant to hydrogen peroxide than wildtype (WT) cells and consume it faster under fermentative conditions. Also, tsa1 Delta tsa2 Delta cells produced higher yields of the 1-hydroxyethyl radical from oxidation of the glucose metabolite ethanol, as proved by spin-trapping experiments. A major role for Fenton chemistry in radical formation was excluded by comparing WT and tsa1 Delta tsa2 Delta cells with respect to their levels of total and chelatable metal ions and of radical produced in the presence of chelators. The main route for 1-hydroxyethyl radical formation was ascribed to the peroxidase activity of Cu, Zn-superoxide dismutase (Sod1), whose expression and activity increased similar to 5- and 2-fold, respectively, in tsa1 Delta tsa2 Delta compared with WT cells. Accordingly, overexpression of human Sod1 in WT yeasts led to increased 1-hydroxyethyl radical production. Relevantly, tsa1 Delta tsa2 Delta cells challenged with hydrogen peroxide contained higher levels of DNA-derived radicals and adducts as monitored by immuno-spin trapping and incorporation of (14)C from glucose into DNA, respectively. The results indicate that part of hydrogen peroxide consumption by tsa1 Delta tsa2 Delta cells is mediated by induced Sod1, which oxidizes ethanol to the 1-hydroxyethyl radical, which, in turn, leads to increased DNA damage. Overall, our studies provide a pathway to account for the hypermutability of peroxiredoxin-null strains.

Dinuclear Azide-Bridged Copper(II) Complex as Building Block for the Assembly of a 2D-Supramolecular Array

A novel Schiff base-copper(II) complex [Cu(2)L(2)(N(3))(2)](ClO(4))(2) 1, where L = (4-imidazolyl)ethylene-2-amino-1-ethylpyridine (apyhist), containing azide-bridges between adjacent copper ions in a dinuclear arrangement was isolated and characterized both in the solid state and in solution by X-ray crystallography and different spectroscopic techniques. Azide binding constants were estimated from titrations of the precursor [CuL(H(2)O)(2)](2+) solutions with sodium azide, giving rise to the azido-bridged species, [Cu(2)L(2)(N(3))(2)](2+). Raman spectra showed asymmetric stretching band at 2060 cm(-1), indicating the presence of azido ligands with a symmetric mu(1,) (1) binding geometry. EPA spectra, in frozen methanol/water solutions at 77 K, exhibited characteristic features of copper centers in tetragonal pyramidal coordination geometry, exhibiting magnetic interactions between them. Further, in solid state, two different values for magnetic coupling in this species were obtained, J/k = -(5.14 +/- 0.02) cm(-1) attributed to the mu(1, 1) azide-bridge mode, and J`z`/k = -(2.94 +/- 0.11) cm(-1) for the interaction between dinuclear moieties via water/perchorate bridges. Finally, an attempt was made to correlate structure and magnetic data for this dinuclear asymmetric end-on azido bridged-copper(II) 1 complex with those of another correlated dinuclear system, complex [Cu(2)L(2)Cl(2)](ClO(4))(2) 2, containing the same tridentate diimine ligand, but with chloro-bridged groups between the copper centres.

A three-dimensional network constructed from the assembly of 1,3-diaminopropane-copper(II) and tetracyanopalladate(II) moieties

The coordination polymer [Cu(Pd(CN)(4))(pn)](n) (pn = 1,3-diaminopropane) has been synthesized and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction. The crystal structure showed that three cyano groups of each [Pd(CN)(4)] unit bridge Cu(II) centers leading to the formation of a three-dimensional network. A series of bifurcated hydrogen bonds between the amino groups of the diamine and the nonbridging cyano groups of the cyanometallate result in the organization of suprarnolecular chains and rings along the polymer. (c) 2008 Elsevier B.V. All rights reserved.

Studies of Design and Assembly Defects on Integrated and Modular Architectures

It is known that despite companies’ efforts to improve the quality of their products, design and assembly defects results in large repair costs both in terms of repair and providing feedback to the origin of the defect. The purpose of this paper is to study these types of defects and the defect rates in design and assembly. The paper presents a web based questionnaire answered by 29 companies. The result shows that the defect rate (defects per product) spanned from 0.01 to 10. Also, design and assembly defects covered 46%, 23% respectively, of all occurred defects. A case study is also presented, performed at a company who recently implemented a modular architecture. In this company, defects from 5 700 integrated product architectures are compared with defects from 431 modular architectures. The average defect rate increased by 21.5% – from 0.65 to 0.79 – when a more modular architecture has been implemented. Furthermore, the study showed that the assembly defects have decreased while the design defects increased. The results presented in this paper will also support the development of the MPV (Module Property Verification) method which is briefly described.

Modular Product Verifications Based on Design for Assembly

The desire to conquer markets through advanced product design and trendy business strategies are still predominant approaches in industry today. In fact, product development has acquired an ever more central role in the strategic planning of companies, and it has extended its influence to R&D funding levels as well. It is not surprising that many national R&D project frameworks within the EU today are dominated by product development topics, leaving production engineering, robotics, and systems on the sidelines. The reasons may be many but, unfortunately, the link between product development and the production processes they cater for are seldom treated in depth. The issue dealt with in this article relates to how product development is applied in order to attain the required production quality levels a company may desire, as well as how one may counter assembly defects and deviations through quantifiable design approaches. It is recognized that product verifications (tests, inspections, etc.) are necessary, but the application of these tactics often result in lead-time extensions and increased costs. Modular architectures improve this by simplifying the verification of the assembled product at module level. Furthermore, since Design for Assembly (DFA) has shown the possibility to identify defective assemblies, it may be possible to detect potential assembly defects already in the product and module design phase. The intention of this paper is to discuss and describe the link between verifications of modular architectures, defects and design for assembly. The paper is based on literature and case studies; tables and diagrams are included with the intention of increasing understanding of the relation between poor designs, defects and product verifications.

Genome-wide association mapping in a wild avian population identifies a link between genetic and phenotypic variation in a life-history trait

Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.