842 research outputs found

    The future of pension systems in europe: a reappraisal.

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    In this paper we examine and ultimately challenge the traditional viewpoint on the future of current pension systems in Europe, according to which the effects of the ageing bomb will inevitably bring down our unfunded PA YG public pension systems. First, we claim that the projected dramatic increase in the pension burden in mostly due to labour market problems and the generosity of the system, rather than to demographic factors. Secondly, we conclude that a fully funded system cannot be achieved without a substantial reduction in current pension payments unless it is financed by issuing earnmarked public debt. Finally we claim that a socially efficient pension system should be a mixed one, partly funded and partly PA VG, on the basis of optimal portfolio allocation in a context of uncertain returns to both human and physical capital and on the role ofPAYG for financing the accumulation of human capital.Pension systems; Funded and unfunded systems; Human and physical capital accumulation;

    Additive manufacturing for solid oxide cell electrode fabrication

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    © The Electrochemical Society.Additive manufacturing can potentially offer a highly-defined electrode microstructure, as well as fast and reproducible electrode fabrication. Selective laser sintering is an additive manufacturing technique in which three-dimensional structures are created by bonding subsequent layers of powder using a laser. Although selective laser sintering can be applied to a wide range of materials, including metals and ceramics, the scientific and technical aspects of the manufacturing parameters and their impact on microstructural evolution during the process are not well understood. In the present study, a novel approach for electrode fabrication using selective laser sintering was evaluated by conducting a proof of concept study. A Ni-patterned fuel electrode was laser sintered on an yttria-stabilized zirconia substrate. The optimization process of laser parameters (laser sintering rate and laser power) and the electrochemical results of a full cell with a laser sintered electrode are presented. The challenges and prospects of using selective laser sintering for solid oxide cell fabrication are discussed

    Dzyaloshinsky-Moriya interaction in vesignieite: A route to freezing in a quantum kagome antiferromagnet

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    We report an electron spin resonance investigation of the geometrically frustrated spin-1/2 kagome antiferromagnet vesignieite, BaCu3_3V2_2O8_8(OH)2_2. Analysis of the line widths and line shifts indicates the dominance of in-plane Dzyaloshinsky-Moriya anisotropy that is proposed to suppress strongly quantum spin fluctuations and thus to promote long-range ordering rather than a spin-liquid state. We also evidence an enhanced spin-phonon contribution that might originate from a lattice instability and discuss the origin of a low-temperature mismatch between intrinsic and bulk susceptibility in terms of local inhomogeneity

    The future of pension systems in europe: a reappraisal

    Get PDF
    In this paper we examine and ultimately challenge the traditional viewpoint on the future of current pension systems in Europe, according to which the effects of the ageing bomb will inevitably bring down our unfunded PA YG public pension systems. First, we claim that the projected dramatic increase in the pension burden in mostly due to labour market problems and the generosity of the system, rather than to demographic factors. Secondly, we conclude that a fully funded system cannot be achieved without a substantial reduction in current pension payments unless it is financed by issuing earnmarked public debt. Finally we claim that a socially efficient pension system should be a mixed one, partly funded and partly PA VG, on the basis of optimal portfolio allocation in a context of uncertain returns to both human and physical capital and on the role ofPAYG for financing the accumulation of human capital

    The anomalous Hall effect in non-collinear antiferromagnetic Mn3_{3}NiN thin films

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    We have studied the anomalous Hall effect (AHE) in strained thin films of the frustrated antiferromagnet Mn3_{3}NiN. The AHE does not follow the conventional relationships with magnetization or longitudinal conductivity and is enhanced relative to that expected from the magnetization in the antiferromagnetic state below TN=260T_{\mathrm{N}} = 260\,K. This enhancement is consistent with origins from the non-collinear antiferromagnetic structure, as the latter is closely related to that found in Mn3_{3}Ir and Mn3_{3}Pt where a large AHE is induced by the Berry curvature. As the Berry phase induced AHE should scale with spin-orbit coupling, yet larger AHE may be found in other members of the chemically flexible Mn3A_{3}AN structure

    Suscetibilidade dos estágios imaturos de Trichogramma pretiosum a óleos inseticidas.

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    O objetivo desse trabalho foi avaliar a suscetibilidade das fases imaturas do parasitoide Trichogramma pretiosum a óleos vegetais e sintéticos utilizados no controle fitossanitário de pragas.Resumo

    Cu,Zn Superoxide Dismutases from Tetrahymena thermophila: Molecular Evolution and Gene Expression of the First Line of Antioxidant Defenses

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    In the present study, we describe the molecular and functional characterization of two Cu,Zn superoxide dismutase (SOD) genes, named tt-sod1a and tt-sod1b from Tetrahymena thermophila, a free-living ciliated protozoan widely used as model organism in biological research. The cDNAs and the putative amino acid sequences were compared with Cu,Zn SODs from other Alveolata. The primary sequences of T. thermophila Cu,Zn SODs are unusually long if compared to orthologous proteins, but the catalytically important residues are almost fully conserved. Both phylogenetic and preliminary homology modeling analyses provide some indications about the evolutionary relationships between the Cu,Zn SODs of Tetrahymena and the Alveolata orthologous enzymes. Copper-dependent regulation of Cu,Zn SODs expression was investigated by measuring mRNA accumulation and enzyme activity in response to chronic exposure to non-toxic doses of the metal. Our in silico analyses of the tt-sod1a and tt-sod1b promoter regions revealed putative consensus sequences similar to half Antioxidant Responsive Elements (hARE), suggesting that the transcription of these genes directly depends on ROS formation. These data emphasize the importance of complex metal regulation of tt-sod1a and tt-sod1b activation, as components of an efficient detoxification pathway allowing the survival of T. thermophila in continued, elevated presence of metals in the environment

    Extensive Characterization of Platelet Gel Releasate From Cord Blood in Regenerative Medicine.

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    Platelet gel derived from peripheral blood is widely applied in many clinical fields of surgery as biomaterial containing growth factors with high proliferative properties. In 2010, we studied and patented a platelet gel derived from cord blood. In this study, due to the crucial role of the factors released by the platelet gel, we first extended the characterization of its releasate. Using a wide proteomic array and splitting the two components of the releasate, that is, platelets and plasma, we have been able to study their growth factor content. Interestingly, we discovered high levels of hormones and molecules able to support tissue growth in the cord blood platelet gel releasate and, in addition, higher concentrations of several angiogenic factors if compared with the peripheral blood counterpart. On the contrary, the latter was much richer in inflammatory factors. The second aim of our work was to study the effects on cell culture, immunophenotype, and function of mesenchymal stem cells exposed to these two platelet gel releasates as substitute for the animal serum. Since our findings nicely show that the use of the peripheral versus the cord blood platelet gel releasate can differently influence the mesenchymal stem cell commitment, we can suggest that in addition to its peculiar angiogenic properties cord blood platelet gel releasate shows excellent proliferative properties as cell culture supplement

    Utilizing grass for the biological production of polyhydroxyalkanoates (PHAs) via green biorefining: Material and energy flows

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    The meat and dairy industry across Europe is dependent on the production of grass. However, faced with competing pressures to reduce the environmental impact of agriculture, a potential future reduction of meat and dairy consumption in western diets, and pressure to minimize food production costs, grass could be used to produce alternative products. The biological production of polyhydroxyalkanoates (PHA) by using grass as the primary carbon source in a novel mixed culture process has been studied. A total of 30,000 t of fresh grass would yield approximately 403.65 t of dried biopolymer granules. On the basis of this early stage, non-optimized process, the cumulative energy demand (CED) of PHA produced from waste grass and cultivated grass was found to be 248.4 MJ/kg and 271.8 MJ/kg, respectively, which is the same order of magnitude as fossil-carbon-based polymers. Improvements in volatile fatty acid yields, reduction in chemical and water inputs, and using residues to make other products will reduce the CED. Given the future requirement to produce polymers with little or no fossil-carbon feedstock, an optimized version of the process could provide a viable future production option that also contributes to the long-term sustainability of agricultural communities
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