159 research outputs found

    The Life-Cycle Hypothesis Revisited: Evidence on Housing Consumption after Retirement

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    According to the life-cycle theory of consumption and saving, foreseeable retirement events should not reduce consumption. Whereas some consumption expenditures may fall when they are self-produced (given higher leisure after retirement), this argument applies especially to housing consumption which can hardly be substituted by home production. We test this hypothesis using micro data for Germany (GSOEP) and find that income reductions when entering retirement have a negative effect on housing expenditures for tenants. For some econometric specifications, this effect is significantly stronger than the one of income changes at other times. While this result suggests that the strict consumption-smoothing hypothesis is violated for the subgroup of nonhome owners, the effect is quantitatively small, which explains the ambiguity of previous findings.consumption smoothing, retirement-consumption puzzle, GSOEP

    New Evidence on the Life-Cycle Hypothesis

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    We revisit the alleged retirement consumption puzzle. According to the life- cycle theory, foreseeable income reductions such as those around retirement should not affect consumption. However, we first recall that given higher leisure endowments after retirement, the theory does predict a fall of total market consumption expenditures. In order not to mistake this predicted drop for a puzzle we focus on housing consumption which can be plausibly regarded as complementary to leisure, and we control for the leisure change in our empirical specifications, using micro data for Germany (SOEP), where housing expenditures are observable as rents for the majority (60%), as well as dwelling relocations. We still find significant negative impacts of the retirement status on housing consumption, which is hard to reconcile with the life-cycle theory. For retirees we also find significant effects of the income reduction at retirement on housing. However, the effects are small in quantitative terms, given the lock-in nature of past housing decisions

    Leisure and housing consumption after retirement: new evidence on the life-cycle hypothesis

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    Foreseeable income reductions around retirement should not affect aggregate consumption. However, given higher leisure endowments after retirement, theory also predicts lower consumption of leisure substitutes. To avoid misinterpreting this predicted drop as a puzzle, our novel approach focuses on housing consumption (complementary to leisure in utility) and controls for leisure changes. In Germany tenants represent roughly half of all households, making many housing expenditures directly observable in micro data. We find significant negative impacts of the retirement status on housing consumption, which is hard to reconcile with life-cycle theory. Despite the lock-in nature of past housing decisions, income reductions at retirement have additional – though small – effects on housing

    GridScore:a tool for accurate, cross-platform phenotypic data collection and visualization

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    Background: Plant breeding and crop research rely on experimental phenotyping trials. These trials generate data for large numbers of traits and plant varieties that needs to be captured efficiently and accurately to support further research and downstream analysis. Traditionally scored by hand, phenotypic data is nowadays collected using spreadsheets or specialized apps. While many solutions exist, which increase efficiency and reduce errors, none offer the same familiarity as printed field plans which have been used for decades and offer an intuitive overview over the trial setup, previously recorded data and plots still requiring scoring.Results: We introduce GridScore which utilizes cutting-edge web technologies to reproduce the familiarity of printed field plans while enhancing the phenotypic data collection process by adding advanced features like georeferencing, image tagging and speech recognition. GridScore is a cross-platform open-source plant phenotyping app that combines barcode-based systems with a guided data collection approach while offering a top-down view onto the data collected in a field layout. GridScore is compared to existing tools across a wide spectrum of criteria including support for barcodes, multiple platforms, and visualizations.Conclusion: Compared to its competition, GridScore shows strong performance across the board offering a complete manual phenotyping experience.</p

    Influence of Different Beam Energies on the Micro-Bunching Instability

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    During the operation of an electron synchrotron with short electron bunches, the beam dynamics are influenced by the occurrence of the micro-bunching instability. This collective instability is caused by the self-interaction of a short electron bunch with its own emitted coherent synchrotron radiation (CSR). Above a certain threshold bunch current dynamic micro-structures start to occur on the longitudinal phase space density. The resulting dynamics depend on various parameters and were previously investigated in relation to, amongst others, the momentum compaction factor and the acceleration voltage. In this contribution, the influence of the energy of the electrons on the dynamics of the micro-bunching instability is studied based on measurements at the KIT storage ring KARA (Karlsruhe Research Accelerator)

    Mode of Action of the Natural Product Allicin in a Plant Model:Influence on the Cytoskeleton and Subsequent Shift in Auxin Localization

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    Allicin is a defense substance produced by garlic cells when they are injured. It is a redox-active thiosulfinate showing redox-activity with a broad range of dose-dependent antimicrobial and biocidal activity. It is known that allicin efficiently oxidizes thiol-groups, and it has been described as a redox toxin because it alters the redox homeostasis in cells and triggers oxidative stress responses. Allicin can therefore be used as a model substance to investigate the action of thiol-specific prooxidants. In order to learn more about the effect of allicin on plants, we used pure synthetized allicin, and studied the influence of allicin on organelle movement in Tradescantia fluminensis as a cytoskeleton-dependent process. Furthermore, we investigated cytoplasmic streaming in sterile filaments of Tradescantia fluminensis, organelle movement using transgenic Arabidopsis with organelle-specifics GFP-tags, and effects on actin and tubulin in the cytoskeleton using GFP-tagged lines. Tubulin and actin were visualized by GFP-tagging in transgenic lines of Arabidopsis thaliana to visualize the influence of allicin on the cytoskeleton. Since auxin transport depends on recycling and turnover of the PIN protein involving cytoskeletal transport to and from the membrane localization sites, auxin distribution in roots was investigated using of transgenic PIN1–GFP, PIN3–GFP, DR5–GFP and DII–VENUS Arabidopsis reporter lines. Allicin inhibited cytoplasmic streaming in T. fluminensis, organelle movement of peroxi-somesperoxisomes, and the Golgi apparatus in a concentration-dependent manner. It also destroyed the correct root tip distribution of auxin, which probably contributed to the observed inhibition of root growth. These observations of the disruption of cytoskeleton-dependent transport processes in plant cells add a new facet to the mechanism of action of allicin as a redox toxin in cells

    On the Perturbation of Synchrotron Motion in the Micro-Bunching Instability

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    The self-interaction of short electron bunches with their own radiation field can have a significant impact on the longitudinal beam dynamics in a storage ring. While higher bunch currents increase the power of the emitted CSR which can be provided to dedicated experiments, it simultaneously amplifies the strength of the self-interaction. Eventually, this leads to the formation of dynamically changing micro-structures within the bunch and thus fluctuating CSR emission, a phenomenon that is generally known as micro-bunching or micro-wave instability. The underlying longitudinal dynamics can be simulated by solving the VFP equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. In this contribution, we focus on the perturbation of the synchrotron motion that is caused by introducing this additional wake field. Therefore, we adopt the perspective of a single particle and eventually comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in the longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. Moreover, we consider synchrotron motion above the instability threshold and thereby motivate an approach to control of the occurring micro-bunching dynamics. Using dynamically adjusted RF amplitude modulations we can directly address the continuous CSR-induced perturbation at the timescale of its occurrence, which allows for substantial control over the longitudinal charge distribution. While the approach is not limited to this particular application, we demonstrate how this can significantly mitigate the micro-bunching dynamics directly above the instability threshold. The gained insights are supported and verified using the VFP solver Inovesa and put into context with measurements at KARA

    Unfallrisiko Parken fĂŒr schwĂ€chere Verkehrsteilnehmer

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    UNFALLRISIKO PARKEN FÜR SCHWÄCHERE VERKEHRSTEILNEHMER Unfallrisiko Parken fĂŒr schwĂ€chere Verkehrsteilnehmer / SchĂŒller, Hagen (Rights reserved) ( -
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