2,565 research outputs found

    Targeting energy savings? Better on primary than final energy and less on intensity metrics

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    Financiado para publicaciĂłn en acceso aberto: Universidade de Vigo/CISUGA eficiencia enerxĂ©tica Ă© un tema crĂ­tico nas polĂ­ticas pĂșblicas, xa que Ă© a clave para desvincular o crecemento econĂłmico e o uso da enerxĂ­a. Estes obxectivos estĂĄn a ser aĂ­nda mĂĄis relevantes para abordar a crise enerxĂ©tica e os novos escenarios xeopolĂ­ticos da guerra de UcraĂ­na. AĂ­nda que varios traballos analizaron os obxectivos de eficiencia enerxĂ©tica, este traballo cĂ©ntrase nos obxectivos de aforro enerxĂ©tico, que representan a principal mĂ©trica de eficiencia para a UniĂłn Europea. Este traballo enche un baleiro na literatura ao analizar os impactos econĂłmicos e ambientais da consecuciĂłn de obxectivos de eficiencia enerxĂ©tica mediante unha polĂ­tica fiscal enerxĂ©tica, simulada por un modelo de equilibrio xeral computable hĂ­brido con gran detalle tecnolĂłxico. DefĂ­nense seis escenarios para o aforro enerxĂ©tico no consumo dos produtos enerxĂ©ticos, utilizando Portugal como caso de estudo. Os resultados relevantes para os responsables polĂ­ticos dos escenarios simulados inclĂșen: (i) acadar obxectivos de aforro enerxĂ©tico por medios alternativos, Ă© dicir, dirixidos ao consumo de enerxĂ­a primaria ou final, proporcionar impactos heteroxĂ©neos na eficiencia do sistema enerxĂ©tico e no PIB, e algĂșns inesperados e indesexables nos impactos ambientais; (ii) unha fiscalidade relativamente mĂĄis baixa de todos os produtos enerxĂ©ticos produce impactos mĂĄis grandes e mĂĄis distorsionadores na xeraciĂłn de electricidade que impostos mĂĄis elevados sĂł sobre os combustibles fĂłsiles (un resultado contraintuitivo), (iii) as polĂ­ticas destinadas a reducir a enerxĂ­a primaria en lugar da enerxĂ­a final proporcionan os mellores resultados (maiores aumentos da eficiencia do sistema enerxĂ©tico con impactos econĂłmicos mĂĄis suaves), o que vai en contra do principio da directiva europea sobre impostos enerxĂ©ticos pola que deben gravarse os produtos finais, independentemente dos insumos utilizados na sĂșa produciĂłn e (iv) e os obxectivos non deben elaborarse en base a indicadores de intensidade enerxĂ©tica. Polo tanto, mĂłstrase que o tamaño dos impactos no balance entre as preocupaciĂłns econĂłmicas e ambientais depende do foco no aforro enerxĂ©tico: de onde (consumo de enerxĂ­a primaria ou final) e a que (fĂłsiles ou todos os produtos enerxĂ©ticos) sexa aplicado.Energy efficiency is a critical issue in public policies, as it is the key to decoupling economic growth and energy use. These objectives are becoming even more relevant to addressing the energy crisis and the new geopolitical scenarios delivered by the Ukraine war. Although several papers have analyzed energy efficiency goals, this paper focuses on energy savings targets, which represent the main efficiency metric for the European Union. This paper fills a gap in literature by analyzing the economic and environmental impacts of attaining energy efficiency targets through an energy fiscal policy, simulated by a hybrid computable general equilibrium model with technological detail. Six scenarios are defined for energy savings in primary/final energy consumption of fossil-fueled/all energy products, using Portugal as a case study. Relevant insights for policy makers from the simulated scenarios include: (i) achieving energy saving targets by alternative means, i.e., directed at primary or final energy consumption, provide heterogeneous impacts on the efficiency of the energy system and GDP, and some unexpected and undesirable outcomes concerning environmental impacts; (ii) a relatively lower taxation of all energy products deliver larger and more distorting impacts on electricity generation than higher taxes on fossil fuels only (a counterintuitive result), (iii) policies aiming to reduce primary energy instead of final energy provide the best outcomes (further increases in the efficiency of the energy system with smoother economic impacts), thereby pointing against the European Energy Taxation directive principle that taxation should be levied on final products, regardless of inputs used in their production and (iv) and targets should not be set up based on energy intensity indicators. Hence, it is shown that the size of the trade-off between economic and environmental concerns depends on where (primary or final energy consumption) and what (fossil or all energy products) energy savings are targeted.Fundação para a CiĂȘncia e a Tecnologia | Ref. UIDB/05037/2020Fundação para a CiĂȘncia e a Tecnologia | Ref. UIDP/05037/2020Fundação para a CiĂȘncia e a Tecnologia | Ref. UID/04085/2020Ministerio de Ciencia y EducaciĂłn | Ref. PID2019-106677GB-I00Xunta de Galicia | Ref. GRC2017/063Universidade de Vigo/CISU

    Nanoscale Au-In alloy-oxide core-shell particles as electrocatalysts for efficient hydroquinone detection

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    The presence of hydroquinone (HQ), a phenol ubiquitous in nature and widely used in industry, needs to be monitored because of its toxicity to the environment. Here we demonstrate efficient detection of HQ using simple, fast, and noninvasive electrochemical measurements on indium tin oxide (ITO) electrodes modified with nanoparticles comprising bimetallic Au–In cores and mixed Au–In oxide shells. Whereas bare ITO electrodes show very low activity for the detection of HQ, their modification with Au–In core–shell nanoparticles induces a pronounced shift of the oxidation peak to lower potentials, i.e., facilitated oxidation. The response of the different electrodes was correlated with the initial composition of the bimetallic nanoparticle cores, which in turn determined the amount of Au and In stabilized on the surface of the amorphous Au–In oxide shells available for the electrochemical reaction. While adding core–shell nanostructures with different compositions of the alloy core facilitates the electrocatalytic (reduction-) oxidation of HQ, the activity is highest for particles with AuIn cores (i.e., a Au:In ratio of 1). This optimal system is found to follow a single pathway, the two-electron oxidation of the quinone–hydroquinone couple, which gives rise to high oxidation peaks and is most effective in facilitating the electrode-to-analyte charge transfer and thus detection. The limits of detection (LOD) decreased when increasing the amount of Au exposed on the surface of the amorphous Au–In oxide shells. The LODs were in the range of 10–5–10–6 M and were lower than those obtained using bulk Au.2022-07-72022-07-07Research carried out in part at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-SC0012704. EB- 14, University of Valladolid (PIF-UVa) Ministerio de Economía, Industria y Competitividad – FEDER (Grant CICYT AGL2012-335

    Intracluster stars in the Virgo cluster core

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    We have investigated the properties of the diffuse light in the Virgo cluster core region, based on the detection of intracluster planetary nebulae (PNe) in four fields. We eliminate the bias from misclassified faint continuum objects, using improved Monte Carlo simulations, and the contaminations by high redshift Lyα\alpha galaxies, using the Lyα\alpha luminosity function in blank fields. Recent spectroscopic observations confirm that our photometric PN samples are well-understood. We find that the diffuse stellar population in the Virgo core region is inhomogeneous on scales of 30'-90': there exist significant field-to-field variations in the number density of PNe and the inferred amount of intracluster light, with some empty fields, some fields dominated by extended Virgo galaxy halos, and some fields dominated by the true intracluster component. There is no clear trend with distance from M87. The mean surface luminosity density, its rms variation, and the mean surface brightness of diffuse light in our 4 fields are ÎŁB=2.7x106\Sigma_B = 2.7 x 10^{6} LB⊙_{B\odot} arcmin−2^{-2}, rms=2.1×106{rms} = 2.1 \times 10^{6} LB⊙_{B\odot} arcmin−2^{-2}, and ΌˉB=29.0\bar{\mu}_{B}=29.0 mag arcsec−2^{-2} respectively. Our results indicate that the Virgo cluster is a dynamically young environment, and that the intracluster component is associated at least partially with local physical processes like galaxy interactions or harassment. We also argue, based on kinematic evidence, that the so-called 'over-luminous' PNe in the halo of M84 are dynamically associated with this galaxy, and must thus be brighter than and part of a different stellar population from the normal PN population in elliptical galaxies.Comment: 31 pages, 6 figure. In press on the Astronomical Journa

    Associated production of H^{\pm} and W^{\mp} in high-energy e+e- collisions in the Minimal Supersymmetric Standard Model

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    We study the associated production of the charged Higgs boson and W^{\pm} gauge boson in high energy e+e- collisions in the Minimal Supersymmetric Standard Model (MSSM). This associated production, which first arises at the one loop level, offers the possibility of producing the charged Higgs boson at the e+e- collider with mass more than half the center-of-mass energy, when the charged Higgs pair production is kinematically forbidden. We present analytic and numerical results for the cross section for e+e- --> W+ H- in the full MSSM, taking into account the previously uncalculated contributions from supersymmetric (SUSY) particles. We find that the contributions of the SUSY particles enhance the cross section over most of SUSY parameter space, especially when the SUSY particles are light, ~200 GeV. With favorable SUSY parameters, at small tan beta, this process can yield more than ten W^{\pm}H^{\mp} events for m_{H^{\pm}} <~ 350 GeV in 500 fb-1 at a 500 GeV e+e- collider, or m_{H^{\pm}} <~ 600 GeV in 1000 fb-1 at a 1000 GeV collider. 80% left-handed polarization of the e- beam improves these reaches to m_{H^{\pm}} <~ 375 GeV and m_{H^{\pm}} <~ 670 GeV, respectively.Comment: v2: 21 pages, 9 figures, comments on Higgs search bounds and new references added, and minor changes; v3: 23 pages, 11 figures, review of literature moved from introduction to new Sec.5 and 2 plots added, references added, typos corrected; v4: bug fixed in nu nubar H0 cross section (Fig.11), version to appear in PR

    The 9<i>H</i>-fluoren vinyl ether derivative SAM461 inhibits bacterial luciferase activity and protects <i>Artemia franciscana</i> from luminescent vibriosis

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    Vibrio campbellii is a major pathogen in aquaculture. It is a causative agent of the so-called “luminescent vibriosis,” a life-threatening condition caused by bioluminescent Vibrio spp. that often involves mass mortality of farmed shrimps. The emergence of multidrug resistant Vibrio strains raises a concern and poses a challenge for the treatment of this infection in the coming years. Inhibition of bacterial cell-to-cell communication or quorum sensing (QS) has been proposed as an alternative to antibiotic therapies. Aiming to identify novel QS disruptors, the 9H-fluroen-9yl vinyl ether derivative SAM461 was found to thwart V. campbellii bioluminescence, a QS-regulated phenotype. Phenotypic and gene expression analyses revealed, however, that the mode of action of SAM461 was unrelated to QS inhibition. Further evaluation with purified Vibrio fischeri and NanoLuc luciferases revealed enzymatic inhibition at micromolar concentrations. In silico analysis by molecular docking suggested binding of SAM461 in the active site cavities of both luciferase enzymes. Subsequent in vivo testing of SAM461 with gnotobiotic Artemia franciscana nauplii demonstrated naupliar protection against V. campbellii infection at low micromolar concentrations. Taken together, these findings suggest that suppression of luciferase activity could constitute a novel paradigm in the development of alternative anti-infective chemotherapies against luminescent vibriosis, and pave the ground for the chemical synthesis and biological characterization of derivatives with promising antimicrobial prospects

    Dysregulation of glucose metabolism is an early event in sporadic Parkinson's disease

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    AbstractUnlike most other cell types, neurons preferentially metabolize glucose via the pentose phosphate pathway (PPP) to maintain their antioxidant status. Inhibiting the PPP in neuronal cell models causes cell death. In rodents, inhibition of this pathway causes selective dopaminergic cell death leading to motor deficits resembling parkinsonism. Using postmortem human brain tissue, we characterized glucose metabolism via the PPP in sporadic Parkinson's disease (PD), Alzheimer's disease (AD), and controls. AD brains showed increased nicotinamide adenine dinucleotide phosphate (NADPH) production in areas affected by disease. In PD however, increased NADPH production was only seen in the affected areas of late-stage cases. Quantifying PPP NADPH-producing enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase by enzyme-linked immunosorbent assay, showed a reduction in the putamen of early-stage PD and interestingly in the cerebellum of early and late-stage PD. Importantly, there was no decrease in enzyme levels in the cortex, putamen, or cerebellum of AD. Our results suggest that down-regulation of PPP enzymes and a failure to increase antioxidant reserve is an early event in the pathogenesis of sporadic PD

    Estimation of the interfacial shears strength, orientation factor and mean equivalent intrinsic tensile strength in old newspaper fiber/polypropylene composites

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    The present paper investigates the suitability of old newspapers (ONPs) as a source of reinforcing fibers for composite materials. Different percentages of ONP fibers were compounded with polypropylene (PP). A coupling agent was added to the compound to improve the interface between matrix and reinforcing fibers. Tensile test were performed to obtain the mechanical properties of the composite materials. Micromechanics of the fibers were obtained using Hirsch model, Bowyer Bader methodology and Kelly-Tyson equations. Due to the presence of a percentage of calcium carbonate in the obtained fibers (10%), the computed intrinsic characteristics were addressed as equivalent. The most important results were the mean equivalent intrinsic tensile strength of the ONP fibers, the mean orientation angle and the mean interfacial shear strength. The contributions of the matrix, the subcritical and the supercritical fibers to the tensile strength of the composite material were also computed. (C) 2013 Elsevier Ltd. All rights reserved.Serrano, A.; Espinach, FX.; Julian, F.; Rey Tormos, RMD.; Mendez, JA.; Mutje, P. (2013). Estimation of the interfacial shears strength, orientation factor and mean equivalent intrinsic tensile strength in old newspaper fiber/polypropylene composites. Composites Part B: Engineering. 50:232-238. doi:10.1016/j.compositesb.2013.02.018S2322385

    Study protocol and rationale of the “Cogniaction project” a cross-sectional and randomized controlled trial about physical activity, brain health, cognition, and educational achievement in schoolchildren

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    Background: Education and health are crucial topics for public policies as both largely determine the future wellbeing of the society. Currently, several studies recognize that physical activity (PA) benefits brain health in children. However, most of these studies have not been carried out in developing countries or lack the transference into the education field. The Cogni-Action Project is divided into two stages, a cross-sectional study and a crossover-randomized trial. The aim of the first part is to establish the associations of PA, sedentarism, and physical fitness with brain structure and function, cognitive performance and academic achievement in Chilean schoolchildren (10–13 years-old). The aim of the second part is to determinate the acute effects of three PA protocols on neuroelectric indices during a working memory and a reading task. Methods: PA and sedentarism will be self-reported and objectively-assessed with accelerometers in a representative subsample, whilst physical fitness will be evaluated through the ALPHA fitness test battery. Brain structure and function will be assessed by magnetic resonance imaging (MRI) in a randomized subsample. Cognitive performance will be assessed through the NeuroCognitive Performance Test, and academic achievement by school grades. In the second part 32 adolescents (12–13 year-old) will be cross-over randomized to these condition (i) “Moderate-Intensity Continuous Training” (MICT), (ii) “Cooperative High-Intensity Interval Training” (C-HIIT), and (iii) Sedentary condition. Neuroelectric indices will be measures by electroencephalogram (EEG) and eye-tracking, working memory by n-back task and reading comprehension by a reading task

    Theiler's Murine Encephalomyelitis Virus as a Vaccine Candidate for Immunotherapy

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    The induction of sterilizing T-cell responses to tumors is a major goal in the development of T-cell vaccines for treating cancer. Although specific components of anti-viral CD8+ immunity are well characterized, we still lack the ability to mimic viral CD8+ T-cell responses in therapeutic settings for treating cancers. Infection with the picornavirus Theiler's murine encephalomyelitis virus (TMEV) induces a strong sterilizing CD8+ T-cell response. In the absence of sterilizing immunity, the virus causes a persistent infection. We capitalized on the ability of TMEV to induce strong cellular immunity even under conditions of immune deficiency by modifying the virus to evaluate its potential as a T-cell vaccine. The introduction of defined CD8+ T-cell epitopes into the leader sequence of the TMEV genome generates an attenuated vaccine strain that can efficiently drive CD8+ T-cell responses to the targeted antigen. This virus activates T-cells in a manner that is capable of inducing targeted tissue damage and glucose dysregulation in an adoptive T-cell transfer model of diabetes mellitus. As a therapeutic vaccine for the treatment of established melanoma, epitope-modified TMEV can induce strong cytotoxic T-cell responses and promote infiltration of the T-cells into established tumors, ultimately leading to a delay in tumor growth and improved survival of vaccinated animals. We propose that epitope-modified TMEV is an excellent candidate for further development as a human T-cell vaccine for use in immunotherapy

    Testing the theory of immune selection in cancers that break the rules of transplantation

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    Modification of cancer cells likely to reduce their immunogenicity, including loss or down-regulation of MHC molecules, is now well documented and has become the main support for the concept of immune surveillance. The evidence that these modifications, in fact, result from selection by the immune system is less clear, since the possibility that they may result from reorganized metabolism associated with proliferation or from cell de-differentiation remains. Here, we (a) survey old and new transplantation experiments that test the possibility of selection and (b) survey how transmissible tumours of dogs and Tasmanian devils provide naturally evolved tests of immune surveillance
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