3,173 research outputs found

    The determinants of savings in the third pension pillar

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    The paper analyses participation in and contributions to the third pillar of the pension system by Belgian households. This pillar represents individual saving for retirement and has been growing rapidly. A detailed dataset of tax declarations over the period from 1993 until 2003 was used to analyse the possible determinants of saving in the third pillar. Firstly, this dataset makes an analysis from a macroeconomic point of view possible, showing an apparent increase in total contributions to the third pillar by 39 p.c. in real terms between 1993 and 2003. This increase is mainly due to a rise in the participation rate (29 p.c. in 1993 and 40 p.c. in 2003). A detailed analysis is provided across the age groups, which further shows the influence of the demographic evolution, the average income of the participants in the third pillar and the contribution rate. The dataset also helps point up a wide number of possible microeconomic determinants of saving for retirement, such as age, income, professional status, civil status, region of residence, property ownership, employment situation, participation in second pillar pension schemes, number of dependents, etc. Moreover, the database allows a distinction to be made between the two forms in the third pillar : pension saving and life insurance. From such a microeconomic point of view, the analysis sheds some light on the major determinants of participation to the third pillar. The main findings show that older households are more likely to opt for a third pillar pension scheme. Furthermore, it appears that households consider the two forms of the third pillar as being complementary rather than substitutes for each other : households that participate in pension saving schemes are also more likely to take out life insurance and vice versa. Besides age, the other determinants that have a positive impact on participation in the third pillar of the pension system are : having higher income, being self-employed, getting an early retirement pension, being a home owner, being married and living in Flanders rather than Brussels or Wallonia.personal finance, pension fund, life insurance, private pensions

    Osteoporosis Epidemiology Among Adults With Cerebral Palsy: Findings From Private and Public Administrative Claims Data

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    Individuals with cerebral palsy (CP) have an increased risk for the early development of osteoporosis; however, little is known about the epidemiology of osteoporosis for adults with CP, which is vital to inform clinical practice for osteoporosis prevention, treatment, and management. The purpose of this cross‐sectional study was to determine sex‐stratified prevalence of osteoporosis among adults with CP, as compared with adults without CP. Data from 2016 were extracted from Optum Clinformatics Data Mart (private insurance administrative claims data) and a random 20% sample from the fee‐for‐service Medicare (public insurance administrative claims data). Diagnostic codes were used to identify CP and osteoporosis diagnoses. Sex‐stratified prevalence of osteoporosis was compared between adults with and without CP for the following age groups: 18 to 30, 31 to 40, 41 to 50, 51 to 60, 61 to 70, and >70 years of age. The overall prevalence of osteoporosis was 4.8% for adults without CP (n = 8.7 million), 8.4% for privately insured adults with CP (n = 7,348), and 14.3% for publicly insured adults with CP (n = 21,907). Women and men with CP had a higher prevalence of osteoporosis compared with women and men without CP for all age groups. Finally, publicly insured women and men with CP had a higher prevalence of osteoporosis compared with privately insured women and men with CP for all age groups, except for the similar prevalence among the 18‐ to 30‐year age group. These findings suggest that osteoporosis is more prevalent among adults with CP compared with adults without CP. Study findings highlight the need for earlier screening and preventive medical services for osteoporosis management among adults with CP. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral ResearchPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152612/1/jbm410231_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152612/2/jbm410231.pd

    RNA-seq-based genome annotation and identification of long-noncoding RNAs in the grapevine cultivar ‘Riesling’

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    Background: The technological advances of RNA-seq and de novo transcriptome assembly have enabled genome annotation and transcriptome profiling in highly heterozygous species such as grapevine (Vitis vinifera L.). This work is an attempt to utilize a de novo-assembled transcriptome of the V. vinifera cultivar ‘Riesling’ to improve annotation of the grapevine reference genome sequence. Results: Here we show that the transcriptome assembly of a single V. vinifera cultivar is insufficient for a complete genome annotation of the grapevine reference genome constructed from V. vinifera PN40024. Further, we provide evidence that the gene models we identified cannot be completely anchored to the previously published V. vinifera PN40024 gene models. In addition to these findings, we present a computational pipeline for the de novo identification of lncRNAs. Our results demonstrate that, in grapevine, lncRNAs are significantly different from protein coding transcripts in such metrics as length, GC-content, minimum free energy, and length-corrected minimum free energy. Conclusions: In grapevine, high-level heterozygosity necessitates that transcriptome characterization be based on cultivar-specific reference genome sequences. Our results strengthen the hypothesis that lncRNAs have thermodynamically different properties than protein-coding RNAs. The analyses of both coding and non-coding RNAs will be instrumental in uncovering inter-cultivar variation in wild and cultivated grapevine species

    Electromagnetically induced transparency in superconducting quantum circuits : Effects of decoherence, tunneling and multi-level cross-talk

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    We explore theoretically electromagnetically-induced transparency (EIT) in a superconducting quantum circuit (SQC). The system is a persistent-current flux qubit biased in a Λ\Lambda configuration. Previously [Phys. Rev. Lett. 93, 087003 (2004)], we showed that an ideally-prepared EIT system provides a sensitive means to probe decoherence. Here, we extend this work by exploring the effects of imperfect dark-state preparation and specific decoherence mechanisms (population loss via tunneling, pure dephasing, and incoherent population exchange). We find an initial, rapid population loss from the Λ\Lambda system for an imperfectly prepared dark state. This is followed by a slower population loss due to both the detuning of the microwave fields from the EIT resonance and the existing decoherence mechanisms. We find analytic expressions for the slow loss rate, with coefficients that depend on the particular decoherence mechanisms, thereby providing a means to probe, identify, and quantify various sources of decoherence with EIT. We go beyond the rotating wave approximation to consider how strong microwave fields can induce additional off-resonant transitions in the SQC, and we show how these effects can be mitigated by compensation of the resulting AC Stark shifts

    Reinstatement of Andrena vernalis Mitchell (Hymenoptera: Andrenidae) from synonymy with A. ziziae Robertson

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    Andrena (Micrandrena) ziziae Robertson, 1891 (Andrenidae) is a well-known species found in a variety of habitats in the eastern and central United States and adjacent southern Canada. Andrena (Micrandrena) vernalis Mitchell, 1960 was described from five female specimens in the eastern United States and was synonymized with A. ziziae by Ribble in 1968. Recently collected specimens from throughout Minnesota have revealed that A. ziziae sensu Ribble is actually two species, one of which matches A. vernalis. Here, we reinstate A. vernalis as a valid species and describe the previously unknown male. We provide diagnostic characters that separate A. ziziae and A. vernalis, as well as data on the geographic range and floral preferences of both species in Minnesota. Andrena vernalis appears to be restricted to high-quality remnant habitats, making it a species of potential conservation concern. These changes will require that previous work on A. ziziae be revisited to determine if A. vernalis is also present

    The Megasecond Chandra X-Ray Visionary Project Observation of NGC 3115 (III): luminosity functions of LMXBs and dependence on stellar environments

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    We have studied the X-ray luminosity function (XLF) of low-mass X-ray binaries (LMXBs) in the nearby lenticular galaxy NGC 3115, using the Megasecond Chandra X-Ray Visionary Project Observation. With a total exposure time of ~1.1 Ms, we constructed the XLF down to a limiting luminosity of ~10^36 erg/s, much deeper than typically reached for other early-type galaxies. We found significant flattening of the overall LMXB XLF from dN/dL \propto L^{-2.2\pm0.4} above 5.5x10^37 erg/s to dN/dL \propto L^{-1.0\pm0.1} below it, though we could not rule out a fit with a higher break at ~1.6x10^38 erg/s. We also found evidence that the XLF of LMXBs in globular clusters (GCs) is overall flatter than that of field LMXBs. Thus our results for this galaxy do not support the idea that all LMXBs are formed in GCs. The XLF of field LMXBs seems to show spatial variation, with the XLF in the inner region of the galaxy being flatter than that in the outer region, probably due to contamination of LMXBs from undetected and/or disrupted GCs in the inner region. The XLF in the outer region is probably the XLF of primordial field LMXBs, exhibiting dN/dL \propto L^{-1.2\pm0.1} up to a break close to the Eddington limit of neutron star LMXBs (~1.7x10^38 erg/s). The break of the GC LMXB XLF is lower, at ~1.1x10^37 erg/s. We also confirm previous findings that the metal-rich/red GCs are more likely to host LMXBs than the metal-poor/blue GCs, which is more significant for more luminous LMXBs, and that more massive GCs are more likely to host LMXBs.Comment: 12 pages, 8 figures, accepted for publication in Ap

    The Megasecond Chandra X-Ray Visionary Project Observation of NGC 3115 (II): properties of point sources

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    We have carried out an in-depth study of low-mass X-ray binaries (LMXBs) detected in the nearby lenticular galaxy NGC 3115, using the Megasecond Chandra X-Ray Visionary Project observation (total exposure time 1.1 Ms). In total we found 136 candidate LMXBs in the field and 49 in globular clusters (GCs) above 2\sigma\ detection, with 0.3--8 keV luminosity L_X ~10^36-10^39 erg/s. Other than 13 transient candidates, the sources overall have less long-term variability at higher luminosity, at least at L_X > 2x10^37 erg/s. In order to identify the nature and spectral state of our sources, we compared their collective spectral properties based on single-component models (a simple power law or a multicolor disk) with the spectral evolution seen in representative Galactic LMXBs. We found that in the L_X versus photon index \Gamma_PL and L_X versus disk temperature kT_MCD plots, most of our sources fall on a narrow track in which the spectral shape hardens with increasing luminosity below L_X~7x10^37 erg/s but is relatively constant (\Gamma_PL~1.5 or kT_MCD~1.5 keV) above this luminosity, similar to the spectral evolution of Galactic neutron star (NS) LMXBs in the soft state in the Chandra bandpass. Therefore we identified the track as the NS LMXB soft-state track and suggested sources with L_X7x10^37 erg/s as Z sources. Ten other sources (five are transients) displayed significantly softer spectra and are probably black hole X-ray binaries in the thermal state. One of them (persistent) is in a metal-poor GC.Comment: 26 pages, 9 figures, four online tables, accepted for publication in Ap

    Commutator Leavitt path algebras

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    For any field K and directed graph E, we completely describe the elements of the Leavitt path algebra L_K(E) which lie in the commutator subspace [L_K(E),L_K(E)]. We then use this result to classify all Leavitt path algebras L_K(E) that satisfy L_K(E)=[L_K(E),L_K(E)]. We also show that these Leavitt path algebras have the additional (unusual) property that all their Lie ideals are (ring-theoretic) ideals, and construct examples of such rings with various ideal structures.Comment: 24 page

    Accuracy threshold for concatenated error detection in one dimension

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    Estimates of the quantum accuracy threshold often tacitly assume that it is possible to interact arbitrary pairs of qubits in a quantum computer with a failure rate that is independent of the distance between them. None of the many physical systems that are candidates for quantum computing possess this property. Here we study the performance of a concatenated error-detection code in a system that permits only nearest-neighbor interactions in one dimension. We make use of a new message-passing scheme that maximizes the number of errors that can be reliably corrected by the code. Our numerical results indicate that arbitrarily accurate universal quantum computation is possible if the probability of failure of each elementary physical operation is below approximately 10^{-5}. This threshold is three orders of magnitude lower than the highest known.Comment: 7 pages, 4 figures, now with error bar
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