6,608 research outputs found

    Evaluating Unpaid Time Contributions by Seniors: A Conceptual Framework

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    In the past, considerable research in gerontology has focused on services provided to seniors. Recently, however, there has a been a growing recognition of the contributions made by seniors to their families, communities and to society. Empirical estimates have been provided by researchers to show how much these contributions are worth in terms of savings in dollar amounts. A critical review of the literature identifies unresolved issues concerning which contributions to count and how to measure and value these contributions. As yet, no clear criteria exist that readily identify the distinction between volunteer activities and unpaid work, what specifically should be counted as an unpaid time contribution, how it should be quantified, and how this unit of contribution should be monetarily valued. The market replacement approach and the opportunity cost approach that are used to assign value to unpaid work often use very different wage rates or levels of income loss. This paper reviews the relevant literature and identifies important issues in evaluating unpaid time contribution of seniors. The authors propose a framework which addresses some of the methodological shortcomings identified in previous research and which provides a guide for future research in this area.seniors; valuing unpaid work

    Health related quality of life of people with non-epileptic seizures: The role of socio-demographic characteristics and stigma

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    Purpose People with non-epileptic seizures (NES) consistently report poorer Health-Related Quality of Life (HRQoL) than people with epilepsy. Yet, unlike in epilepsy, knowledge of how social factors influence the HRQoL of adults with NES is limited. To add to the evidence base, this study explores the relationship between HRQoL and perceived stigma among adults with NES, and the role of socio-demographic characteristics. Methods Data was gathered from a survey of 115 people living with the condition, recruited from online support groups. Participants provided socio-demographic and health-related data and completed a series of questions investigating their HRQoL (QOLIE-31) and stigma perceptions (10-item Epilepsy Stigma Scale). Results Participants were found to experience high levels of perceived stigma (median 5.2, mean 4.9). A significant and moderate inverse correlation was observed between HRQoL and stigma (rs − 0.474, p = < 0.001); suggesting higher perceptions of stigma contribute to poorer HRQoL among adults with NES. Stigma perceptions were found to be most strongly associated with the seizure worry (rs = − 0.479), emotional wellbeing (rs = − 0.421), and social functioning (rs = 0.407) HRQoL domains. Participants who reported being in employment or education were found to have significantly better HRQoL than those who were not (p = < 0.001). Conclusion More (qualitative and quantitative) research is justified to understand how – and why – those with the condition experience stigmatisation, and the factors that impede and help facilitate the participation of people with NES in education and employment

    Heisenberg Spin Bus as a Robust Transmission Line for Perfect State Transfer

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    We study the protocol known as quantum state transfer for a strongly coupled antiferromagnetic spin chain or ring (acting as a spin bus), with weakly coupled external qubits. By treating the weak coupling as a perturbation, we find that perfect state transfer (PST) is possible when second order terms are included in the expansion. We also show that PST is robust against variations in the couplings along the spin bus and between the bus and the qubits. As evidence of the quantum interference which mediates PST, we show that the optimal time for PST can be smaller with larger qubit separations, for an even-size chain or ring.Comment: 6 figures,submitte

    Open Gromov-Witten Invariants of Toric Calabi-Yau 3-Folds

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    We present a proof of the mirror conjecture of Aganagic-Vafa [arXiv:hep-th/0012041] and Aganagic-Klemm-Vafa [arXiv:hep-th/0105045] on disk enumeration in toric Calabi-Yau 3-folds for all smooth semi-projective toric Calabi-Yau 3-folds. We consider both inner and outer branes, at arbitrary framing. In particular, we recover previous results on the conjecture for (i) an inner brane at zero framing in the total space of the canonical line bundle of the projective plane (Graber-Zaslow [arXiv:hep-th/0109075]), (ii) an outer brane at arbitrary framing in the resolved conifold (Zhou [arXiv:1001.0447]), and (iii) an outer brane at zero framing in the total space of the canonical line bundle of the projective plane (Brini [arXiv:1102.0281, Section 5.3]).Comment: 39 pages, 11 figure

    Quantum Group as Semi-infinite Cohomology

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    We obtain the quantum group SLq(2)SL_q(2) as semi-infinite cohomology of the Virasoro algebra with values in a tensor product of two braided vertex operator algebras with complementary central charges c+cˉ=26c+\bar{c}=26. Each braided VOA is constructed from the free Fock space realization of the Virasoro algebra with an additional q-deformed harmonic oscillator degree of freedom. The braided VOA structure arises from the theory of local systems over configuration spaces and it yields an associative algebra structure on the cohomology. We explicitly provide the four cohomology classes that serve as the generators of SLq(2)SL_q(2) and verify their relations. We also discuss the possible extensions of our construction and its connection to the Liouville model and minimal string theory.Comment: 50 pages, 7 figures, minor revisions, typos corrected, Communications in Mathematical Physics, in pres

    The BV-algebra structure of W_3 cohomology

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    We summarize some recent results obtained in collaboration with J. McCarthy on the spectrum of physical states in W3W_3 gravity coupled to c=2c=2 matter. We show that the space of physical states, defined as a semi-infinite (or BRST) cohomology of the W3W_3 algebra, carries the structure of a BV-algebra. This BV-algebra has a quotient which is isomorphic to the BV-algebra of polyvector fields on the base affine space of SL(3,C)SL(3,C). Details have appeared elsewhere. [Published in the proceedings of "Gursey Memorial Conference I: Strings and Symmetries," Istanbul, June 1994, eds. G. Aktas et al., Lect. Notes in Phys. 447, (Springer Verlag, Berlin, 1995)]Comment: 8 pages; uses macros tables.tex and amssym.def (version 2.1 or later

    Radiation effects in uranium-niobium titanates

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    Pyrochlore is an important actinide host phase proposed for the immobilization of high level nuclear wastes and excess weapon plutonium.[1] Synthetic pyrochlore has a great variety of chemical compositions due to the possibility of extensive substitutions in the pyrochlore structure.[2] During the synthesis of pyrochlore, additional complex titanate phases may form in small quantities. The response of these phases to radiation damage must be evaluated because volume expansion of minor phases may cause micro-fracturing. In this work, two complex uranium-niobium titanates, U3NbO9.8U3NbO9.8 (U-rich titanate) and Nb3UO10Nb3UO10 (Nb-rich titanate) were synthesized by the alkoxide/nitrate route at 1300 °C under an argon atmosphere. The phase composition and structure were analyzed by EDS, BSE, XRD, EMPA and TEM techniques. An 800 KeVKr2+800KeVKr2+ irradiation was performed using the IVEM-Tandem Facility at Argonne National Laboratory in a temperature range from 30 K to 973 K. The radiation effects were observed by in situ TEM. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87573/2/403_1.pd
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