102 research outputs found
Employment and Growth in an Aging Society. A Simulation Study for Austria
In this study we use a long run macroeconomic model for Austria to simulate the effects of aging on employment, output growth, and the solvency of the social security system. By disaggregating the population into six age cohorts and modelling sex specific participation rates for each cohort, we are able to account for the future demographic trends. Apart from a baseline scenario, we perform three alternative simulations that highlight the effects of aging from different perspectives. These include (1) purely demographic developments, (2) increasing labour market imperfections, and (3) higher economic growth due to a productivity shock.Economic growth, Aging, Austria
A Long-run Macroeconomic Model of the Austrian Economy (A-LMM). Model Documentation and Simulations
In this paper we develop a long run macroeconomic model for Austria to simulate the effects of aging on employment, output growth, and the solvency of the social security system. By disaggregating the population into six age cohorts and modelling sex specific participation rates for each cohort, we are able to account for the future demographic trends. Apart from a baseline scenario, we perform six alternative simulations that highlight the effects of aging from different perspectives. These include two population projections with high life expectancy and with low fertility, a dynamic activity rate scenario, two scenarios with a stable fiscal balance of social security and an alternative pension indexation, and a scenario with higher productivity growth
Position controlled self-catalyzed growth of GaAs nanowires by molecular beam epitaxy
GaAs nanowires are grown by molecular beam epitaxy using a self-catalyzed,
Ga-assisted growth technique. Position control is achieved by nano-patterning a
SiO2 layer with arrays of holes with a hole diameter of 85 nm and a hole pitch
varying between 200 nm and 2 \mum. Gallium droplets form preferentially at the
etched holes acting as catalyst for the nanowire growth. The nanowires have
hexagonal cross-sections with {110} side facets and crystallize predominantly
in zincblende. The interdistance dependence of the nanowire growth rate
indicates a change of the III/V ratio towards As-rich conditions for large hole
distances inhibiting NW growth.Comment: 9 pages, 4 figure
Determination of hole g-factor in InAs/InGaAs/InAlAs quantum wells by magneto-photoluminescence studies
A circularly polarized magneto-photoluminescence (magneto-PL) technique has been applied to investigate the Zeeman effect in InAs/InGaAs/InAlAs quantum wells (QWs) in the Faraday geometry. Structures with different thicknesses of the QW barriers have been studied in the magnetic field parallel and tilted with respect to the sample normal. The effective electron-hole g-factor has been found by measurement of splitting of polarized magneto-PL lines. Lande factors of electrons have been calculated using the 14-band k.p method, and the g-factor of holes was determined by subtracting the calculated contribution of the electrons from the effective electron-hole g-factor. Anisotropy of the hole g-factor has been studied applying the tilted magnetic field. Published by AIP Publishing
Optical investigation of electrical spin injection into an inverted two-dimensional elctron gas structure
We report on electrical spin injection from (Ga, Mn) As into a high-mobility two-dimensional electron gas confined at an (Al, Ga) As/GaAs interface. Besides standard nonlocal electrical detection, we use amagneto-optical approach which provides cross-sectional images of the spin accumulation at the cleaved edge of the sample, yielding spin decay lengths on the order of 2 mu m. In some cases we find a nonmonotonic bias voltage dependence of the spin signal, which may be linked to ballistic tunneling effects during spin injection. We observe a clear Hanle depolarization using a technique which is free of dynamic nuclear polarization effects. Fitting the data with the standard drift-diffusion model of spin injection suggests averaged in-plane spin lifetimes on the order of 1 ns
Tracking CNS and systemic sources of oxidative stress during the course of chronic neuroinflammation
The functional dynamics and cellular sources of oxidative stress are central to understanding MS pathogenesis but remain elusive, due to the lack of appropriate detection methods. Here we employ NAD(P)H fluorescence lifetime imaging to detect functional NADPH oxidases (NOX enzymes) in vivo to identify inflammatory monocytes, activated microglia, and astrocytes expressing NOX1 as major cellular sources of oxidative stress in the central nervous system of mice affected by experimental autoimmune encephalomyelitis (EAE). This directly affects neuronal function in vivo, indicated by sustained elevated neuronal calcium. The systemic involvement of oxidative stress is mirrored by overactivation of NOX enzymes in peripheral CD11b(+) cells in later phases of both MS and EAE. This effect is antagonized by systemic intake of the NOX inhibitor and anti-oxidant epigallocatechin-3-gallate. Together, this persistent hyper-activation of oxidative enzymes suggests an "oxidative stress memory" both in the periphery and CNS compartments, in chronic neuroinflammation
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