994 research outputs found

    The energy-growth nexus in 3 Latin American countries on the basis of the EKC framework: in the case of Argentina, Brazil, and Chile

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    In this paper, the efects of economic growth and four diferent types of energy consumption (oil, natural gas, hydroelectricity, and renewable energy) on environmental quality in terms of carbon dioxide (CO2) emissions were examined within the framework of the Environmental Kuznets Curve (EKC) for three Latin American countries, namely, Argentina, Brazil, and Chile, from 1975 to 2018. The autoregressive distributed lag (ARDL) in the form of Error Correction Mechanism (ECM) was used to verify the validity of the EKC hypothesis and the impacts of the variables in the short and the long run alike. Furthermore, the Toda-Yamamoto Granger causality test was carried out to identify the direction of causality between the variables. From ARDL-ECM estimation, the EKC was confrmed (inverted U-shaped curve between income growth and CO2 emissions) only in Argentina in the long run but not in Brazil and Chile. Based on the fndings, renewable energy can have a great potential in reducing CO2 emissions in the future, but this advantage has not been fully exploited yet since a signifcant negative impact on CO2 emissions was only found in Chile. Also, the use of other less carbon-intensive energy sources such as natural gas and hydropower if they could be combined with renewable energy would be of great beneft and contribute to enhancing environmental quality and energy security in the short and the medium term and to successful lowcarbon energy transition in the long run in Argentina, Brazil, and ChileOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

    The synergy effect through combination of the digital economy and transition to renewable energy on green economic growth: Empirical study of 18 Latin American and caribbean countries

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    Tremendous effects on the global economy in terms of economic, social and environmental costs remind us of the catastrophic consequences of climate change and global warming caused by CO2 emissions. Therefore, accelerating decarbonization of the global energy system should be put in place to curb large amount of CO2 emission from hydrocarbon energy sources on which the current global value chain of production heavily relies.This study focuses on analyzing the effects of renewable energy transition, the digital economy, and the synergy between them on green economic growth in 18 Latin American countries. To capture the multidimensionality of these transitions, the Renewable Energy Transition Index (RETI) and the Digital Economy Index (DEI) are developed using the Principal Component Factor (PCF) technique. The FixedEffect Panel Threshold Regression (FEPTR) substantiates that renewable energy transition has a significant threshold effect on economic growth and environmental sustainability depending on the level of income and carbon emissions. On the other hand, the Method of Moments Quantile Regression (MMQR) shows that both renewable energy transition and the digital economy have a significant positive impact on economic growth in all quantile groups. For the environmental sustainability, only renewable energy transition is found to have a positive impact in all quantile groups. From the synergistic effect perspectives, the CO2 emissions reduction is observed in both the low and middle quantile groups, but the economic growth promotion is only observed in a low quantile grou

    Probing the messenger of supersymmetry breaking by the muon anomalous magnetic moment

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    Motivated by the recently measured muon's anomalous magnetic moment aμa_{\mu}, we examine the supersymmetry contribution to aμa_{\mu} in various mediation models of supersymmetry breaking which lead to predictive flavor conserving soft parameters at high energy scale. The studied models include dilaton/modulus-mediated models in heterotic string/MM theory, gauge-mediated model, no-scale or gaugino-mediated model, and also the minimal and deflected anomaly-mediated models. For each model, the range of aμSUSYa^{SUSY}_{\mu} allowed by other experimental constraints, e.g. b --> s\gamma and the collider bounds on superparticle masses, is obtained together with the corresponding parameter region of the model. Gauge-mediated models with low messenger scale can give any aμSUSYa^{SUSY}_{\mu} within the 2σ2\sigma bound. In many other models, b --> s\gamma favors aμSUSYa^{SUSY}_{\mu} smaller than either the 1σ-1\sigma value (26×101026\times 10^{-10}) or the central value (42×101042\times 10^{-10}).Comment: RevTeX, 29 pages, 14 eps figures, figure for deflected anomaly mediation is corrected, reference adde

    Orthogonality properties of transverse eigenmodes of phase conjugate optical resonators

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    The orthogonality properties of the transverse eigenmodes of optical resonators which have phase conjugate mirrors at both ends are derived. As in conventional resonators and also resonators with only one phase conjugate mirror, it is shown that the transverse eigenmodes are essentially biorthogonal, a relation which is satisfied between the set of modes propagating in one direction around the resonator and the adjoint set of modes propagating in the reverse direction

    Bright color optical switching device by polymer network liquid crystal with a specular reflector

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    The color optical switching device by polymer network liquid crystal (PNLC) with color filter on a specular reflector shows excellent performance; white reflectance of 22%, color gamut of 32%, and contrast ratio up to 50:1 in reflective mode measurement. The view-angle dependence of the reflectance can be adjusted by changing the PNLC thickness. The color chromaticity shown by the device is close to the limit value of color filters, and its value nearly remains with respect to the operating voltage. These optical properties of the device can be explained from the prediction based on multiple interactions between the light and the droplets of liquid crystal. The high reflectance, vivid color image, and moderate responds time allow the PNLC device to drive good color moving image. It can widely extend the applications of the reflective device. © 2011 Optical Society of America.1

    Translational repression of mouse mu opioid receptor expression via leaky scanning

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    Mu opioid receptor (MOR) expression is under temporal and spatial controls, but expression levels of the MOR gene are relatively low in vivo. In addition to transcriptional regulations, upstream AUGs (uAUGs) and open reading frames (uORFs) profoundly affect the translation of the primary ORF and thus the protein levels in several genes. The 5′-untranslated region (UTR) of mouse MOR mRNA contains three uORFs preceding the MOR main initiation codon. In MOR-fused EGFP or MOR promoter/luciferase reporter constructs, mutating each uAUG individually or in combinations increased MOR transient heterologous expression in neuroblastoma NMB and HEK293 cells significantly. Translation of such constructs increased up to 3-fold without altering the mRNA levels if either the third uAUG or both the second and third AUGs were mutated. Additionally, these uAUG-mediated translational inhibitions were independent of their peptide as confirmed by internal mutation analyses in each uORF. Translational studies indicated that protein syntheses were initiated at these uAUG initiation sites, with the third uAUG initiating the highest translation level. These results support the hypothesis that uORFs in mouse MOR mRNA act as negative regulators through a ribosome leaky scanning mechanism. Such leaky scanning resulted in the suppression of mouse MOR under normal conditions

    High-resolution crystal structure of the non-specific lipid-transfer protein from maize seedlings

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    AbstractBackground: The movement of lipids between membranes is aided by lipid-transfer proteins (LTPs). Some LTPs exhibit broad specificity, transferring many classes of lipids, and are termed non-specific LTPs (ns-LTPs). Despite their apparently similar mode of action, no sequence homology exists between mammalian and plant ns-LTPs and no three-dimensional structure has been reported for any plant ns-LTP.Results We have determined the crystal structure of ns-LTP from maize seedlings by multiple isomorphous replacement and refined the structure to 1.9 å resolution. The protein comprises a single compact domain with four α-helices and a long C-terminal region. The eight conserved cysteines form four disulfide bridges (assigned as Cys4–Cys52, Cys14–Cys29, Cys30–Cys75, and Cys50–Cys89) resolving the ambiguity that remained from the chemical determination of pairings in the homologous protein from castor bean. Two of the bonds, Cys4–Cys52 and Cys50–Cys89, differ from what would have been predicted from sequence alignment with soybean hydrophobic protein. The complex between maize ns-LTP and hexadecanoate (palmitate) has also been crystallized and its structure refined to 1.8 å resolution.Conclusion The fold of maize ns-LTP places it in a new category of all-α-type structure, first described for soybean hydrophobic protein. In the absence of a bound ligand, the protein has a tunnel-like hydrophobic cavity, which is large enough to accommodate a long fatty acyl chain. In the structure of the complex with palmitate, most of the acyl chain is buried inside this hydrophobic cavity

    Hepatitis C Virus NS5B Protein Is a Membrane-Associated Phosphoprotein with a Predominantly Perinuclear Localization

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    AbstractHepatitis C virus NS5B protein is an RNA-dependent RNA polymerase. To investigate the properties and function of this protein, we have expressed the NS5B protein in insect and mammalian cells. NS5B was found to be present as fine speckles in the cytoplasm, particularly concentrated in the perinuclear region, suggesting its association with the nuclear membrane, the endoplasmic reticulum, or the Golgi complex. This conclusion was supported by the biochemical demonstration that NS5B was associated with the membranes in the cells. Furthermore, it was shown that NS5B protein is a phosphoprotein. These properties may be related to its function as an RNA polymerase
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