5,831 research outputs found

    The State of Democracy and Authoritarianism in Mexico After the 2012 Presidential Elections

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    As part of its Spring 2013 Lecture Series, the Latin American and Iberian Institute at the University of New Mexico hosted Dr. John Ackerman and Dr. Lorenzo Meyer on Thursday, January 31, 2013. In back-to-back presentations these leading political analysts discussed The State of Democracy and Authoritarianism in Mexico After the 2012 Presidential Elections. Dr. Ackerman first explored the topic of Deconsolidating Authoritarianism: Learning from Mexico\u27s Failed Transitions. Dr. Lorenzo Meyer followed, pursuing the topic of Mexico: Democratic Authoritarianism.https://digitalrepository.unm.edu/laii_events/1068/thumbnail.jp

    Stereoselective protecting group free synthesis of d,l-gulose ethyl glycoside via multicomponent enyne cross metathesis—hetero Diels–Alder reaction

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    An efficient and stereoselective synthesis of d,l-gulose was described. The key step of the synthetic route is represented by a multicomponent enyne cross metathesis—hetero Diels–Alder reaction which allows the formation of the pyran ring from cheap and commercially available substrates in a single synthetic step. The synthesis of d,l-gulose was accomplished without the use of protecting groups making this approach highly desirable also in terms of atom economy

    Amending Contracts for Choreographies

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    Distributed interactions can be suitably designed in terms of choreographies. Such abstractions can be thought of as global descriptions of the coordination of several distributed parties. Global assertions define contracts for choreographies by annotating multiparty session types with logical formulae to validate the content of the exchanged messages. The introduction of such constraints is a critical design issue as it may be hard to specify contracts that allow each party to be able to progress without violating the contract. In this paper, we propose three methods that automatically correct inconsistent global assertions. The methods are compared by discussing their applicability and the relationships between the amended global assertions and the original (inconsistent) ones.Comment: In Proceedings ICE 2011, arXiv:1108.014

    Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}

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    We review the presence and signatures of the non-equilibrium processes, both non-Maxwellian distributions and non-equilibrium ionization, in the solar transition region, corona, solar wind, and flares. Basic properties of the non-Maxwellian distributions are described together with their influence on the heat flux as well as on the rates of individual collisional processes and the resulting optically thin synthetic spectra. Constraints on the presence of high-energy electrons from observations are reviewed, including positive detection of non-Maxwellian distributions in the solar corona, transition region, flares, and wind. Occurrence of non-equilibrium ionization is reviewed as well, especially in connection to hydrodynamic and generalized collisional-radiative modelling. Predicted spectroscopic signatures of non-equilibrium ionization depending on the assumed plasma conditions are summarized. Finally, we discuss the future remote-sensing instrumentation that can be used for detection of these non-equilibrium phenomena in various spectral ranges.Comment: Solar Physics, accepte

    A counterion study of a series of [Cu(P^P)(N^N)][A] compounds with bis(phosphane) and 6-methyl and 6,6'-dimethyl-substituted 2,2'-bipyridine ligands for light-emitting electrochemical cells

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    The syntheses and characterisations of a series of heteroleptic copper(i) compounds [Cu(POP)(Mebpy)][A], [Cu(POP)(Me(2)bpy)][A], [Cu(xantphos)(Mebpy)][A] and [Cu(xantphos)(Me(2)bpy)][A] in which [A](-) is [BF4](-), [PF6](-), [BPh4](-) and [BAr4F](-) (Mebpy = 6-methyl-2,2 '-bipyridine, Me(2)bpy = 6,6 '-dimethyl-2,2 '-bipyridine, POP = oxydi(2,1-phenylene)bis(diphenylphosphane), xantphos = (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane), [BAr4F](-) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) are reported. Nine of the compounds have been characterised by single crystal X-ray crystallography, and the consequences of the different anions on the packing interactions in the solid state are discussed. The effects of the counterion on the photophysical properties of [Cu(POP)(NN)][A] and [Cu(xantphos)(NN)][A] (NN = Mebpy and Me(2)bpy) have been investigated. In the solid-state emission spectra, the highest energy emission maxima are for [Cu(xantphos)(Mebpy)][BPh4] and [Cu(xantphos)(Me(2)bpy)][BPh4] (lambda emmax = 520 nm) whereas the lowest energy lambda emmax values occur for [Cu(POP)(Mebpy)][PF6] and [Cu(POP)(Mebpy)][BPh4] (565 nm and 563 nm, respectively). Photoluminescence quantum yields (PLQYs) are noticeably affected by the counterion; in the [Cu(xantphos)(Me(2)bpy)][A] series, solid-state PLQY values decrease from 62% for [PF6](-), to 44%, 35% and 27% for [BF4](-), [BPh4](-) and [BAr4F](-), respectively. This latter series of compounds was used as active electroluminescent materials on light-emitting electrochemical cells (LECs). The luminophores were mixed with ionic liquids (ILs) [EMIM][A] ([EMIM](+) = [1-ethyl-3-methylimidazolium](+)) containing the same or different counterions than the copper(i) complex. LECs containing [Cu(xantphos)(Me(2)bpy)][BPh4] and [Cu(xantphos)(Me(2)bpy)][BAr4F] failed to turn on under the LEC operating conditions, whereas those with the smaller [PF6](-) or [BF4](-) counterions had rapid turn-on times and exhibited maximum luminances of 173 and 137 cd m(-2) and current efficiencies of 3.5 and 2.6 cd A(-1), respectively, when the IL contained the same counterion as the luminophore. Mixing the counterions ([PF6](-) and [BF4](-)) of the active complex and the IL led to a reduction in all the figures of merit of the LECs

    Hydrogen sulfide increases production of NADPH oxidase-dependent hydrogen peroxide and phospholipase D-derived phosphatidic acid in guard cell signaling

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    Hydrogen sulfide (H2S) is an important gaseous signaling molecule in plants that participates in stress responses and development. L-Cys desulfhydrase 1, one of the enzymatic sources of H2S in plants, participates in abscisic acid-induced stomatal closure. We combined pharmacological and genetic approaches to elucidate the involvement of H2S in stomatal closure and the interplay between H2S and other second messengers of the guard cell signaling network, such as hydrogen peroxide (H2O2) and phospholipase D (PLD)-derived phosphatidic acid in Arabidopsis (Arabidopsis thaliana). Both NADPH oxidase isoforms, respiratory burst oxidase homolog (RBOH)D and RBOHF, were required for H2S-induced stomatal closure. In vivo imaging using the cytosolic ratiometric fluorescent biosensor roGFP2-Orp1 revealed that H2S stimulates H2O2 production in Arabidopsis guard cells. Additionally, we observed an interplay between H2S and PLD activity in the regulation of reactive oxygen species production and stomatal movement. The PLDα1 and PLDδ isoforms were required for H2S-induced stomatal closure, and most of the H2S-dependent H2O2 production required the activity of PLDα1. Finally, we showed that H2S induced increases in the PLDδ-derived phosphatidic acid levels in guard cells. Our results revealed the involvement of H2S in the signaling network that controls stomatal closure, and suggest that H2S regulates NADPH oxidase and PLD activity in guard cells.Fil: Scuffi, Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Nietzel, Thomas. Westfalische Wilhelms Universitat; Alemania. Universitat Bonn; AlemaniaFil: Di Fino, Luciano Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Meyer, Andreas J.. Universitat Bonn; AlemaniaFil: Lamattina, Lorenzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Schwarzlände, Markus. Westfalische Wilhelms Universitat; Alemania. Universitat Bonn; AlemaniaFil: Laxalt, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Garcia-Mata, Carlos. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin

    Experimental results and strength model identification of pure iridium

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    Intense and high energy proton beams are impacted with fixed materials (targets) in order to produce new particles and secondary beams at CERN. In some of these targets, the requirement of reaching high yield production of secondary particles points out to the use of high density materials. The interaction of the beam with the atoms and nuclei of these materials produce extremely fast depositions of energy, highly soliciting them from thermo-structural point of view due to subsequent rise of temperature and pressure waves. Iridium is a good candidate material since exhibits very high density, high melting point, good strength and stability at high temperature, and resistance to thermal shock. The main goal of this study is the investigation of the mechanical behaviour at different temperatures and strain-rates in tensile loading condition of pure iridium. A series of tests at room temperature at different strain-rates (from 10-3 s-1 up to 104 s-1) was performed in order to obtain information about strain and strain-rate sensitivity of the material. In addition, a series of tests at different temperatures in both quasistatic and high strain-rate loading conditions was performed in order to obtain information about the thermal softening of the material (from room temperature up to 1250 °C). The experimental data were used to identify a strength model able to predict the material behaviour over wide ranges of variation of the variables of interest

    Biochar standardization and legislation harmonization

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    It is a relatively new concept to use biochar as soil amendment and for climate change mitigation. For this reason, the national and supranational legislation in the EU is not yet adequately prepared to regulate both the production and the application of biochar. Driven by this “regulatory gap”, voluntary biochar quality standards have been formed in Europe with the European Biochar Certificate, in the UK with the Biochar Quality Mandate and in the USA with the IBI Standard which is intended to be used internationally. In parallel to this, biochar producers and biochar users in a number of EU countries were partly successful in fitting the new biochar product into the existing national legislation for fertilisers, soil improvers and composts. The intended revision of the EC Regulation 2003/2003 on fertilisers offers the opportunity to regulate the use of biochar at the EU level. This publication summarizes the efforts on biochar standardization which have been carried out by voluntary products standards and illustrates existing legislation in EU member states, which apply to the production and use of biochar. It describes existing and planned EU regulations, which impact biochar applications and it develops recommendations on the harmonization of biochar legislation in the EU.  First published online: 24 Jan 201

    Integral field spectroscopy with SINFONI of VVDS galaxies. I. Galaxy dynamics and mass assembly at 1.2 < z < 1.6

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    Context. Identifying the main processes of galaxy assembly at high redshifts is still a major issue to understand galaxy formation and evolution at early epochs in the history of the Universe. Aims. This work aims to provide a first insight into the dynamics and mass assembly of galaxies at redshifts 1.2<z<1.6, the early epoch just before the sharp decrease of the cosmic star formation rate. Methods. We use the near-infrared integral field spectrograph SINFONI on the ESO-VLT under 0.65 seeing to obtain spatially resolved spectroscopy on nine emission line galaxies with 1.2<z<1.6 from the VIMOS VLT Deep Survey. We derive the velocity fields and velocity dispersions on kpc scales using the Halpha emission line. Results. Out of the nine star-forming galaxies, we find that galaxies distribute in three groups: two galaxies can be well reproduced by a rotating disk, three systems can be classified as major mergers and four galaxies show disturbed dynamics and high velocity dispersion. We argue that there is evidence for hierarchical mass assembly from major merger, with most massive galaxies with M>10^11Msun subject to at least one major merger over a 3 Gyr period as well as for continuous accretion feeding strong star formation. Conclusions. These results point towards a galaxy formation and assembly scenario which involves several processes, possibly acting in parallel, with major mergers and continuous gas accretion playing a major role. Well controlled samples representative of the bulk of the galaxy population at this key cosmic time are necessary to make further progress.Comment: 23 pages, 22 figures, accepted for publication in A&

    Hematopoietic Stem/Progenitor Cells Express Functional Mitochondrial Energy-Dependent Cystic Fibrosis Transmembrane Conductance Regulator

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    Bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) encompass a wide array of cell subsets with different capacities of engraftment and injured tissue-regenerating potential. The characterization/isolation of the stem cell subpopulations represents a major challenge to improve the efficacy of transplantation protocols used in regenerative medicine. Cystic fibrosis (CF) is one of the diseases whose hope of cure relies on the successful application of cell-based gene therapy. This study was aimed at characterizing murine HSPCs on the basis of their bioenergetic competence and CF transmembrane conductance regulator (CFTR) expression. Positively immunoselected Sca-1(+) HSPCs encompassed 2 populations distinguished by their different size, Sca-1 expression and mitochondrial content. The smaller were the cells, the higher was Sca-1 expression and the lower was the intracellular density of functional mitochondria. Reverse transcription-polymerase chain reaction and western blotting revealed that HSPCs expressed CFTR mRNA and protein, which was also functional, as assessed by spectrofluorimetric and patch-clamp techniques. Inhibition of mitochondrial oxidative phosphorylation by oligomycin resulted in a 70% decrease of both the intracelluar adenosine triphosphate content and CFTR-mediated channel activity. Finally, HSPCs with lower Sca-1 expression and higher mitochondrial content displayed higher CFTR levels. Our findings identify 2 subpopulations in HSPCs and unveil a so-far unappreciated relationship between bioenergetic metabolism and CFTR in HSPC biology
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