15,213 research outputs found

    A Measure of Core Inflation in the UK

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    We develop a measure of core inflation in the UK over the period January1987 - December 1998, following the work of Bryan and Cecchetti (1996),Bryan, Cecchetti and Wiggins (1997) and Roger (1997). Disaggregation is into85 price categories. Given the high kurtosis of the price change distribution over this period, a trimmed mean is a more robust estimator of core inflation than other published measures such as the RPIX widely used in the UK, in particular by the Bank of England when targeting inflation. We discuss the relative advantages of our measure of core inflation, with emphasis on the determination of an optimal trimming point and on the analysis of the products whose price changes are excluded from our measure in each time period. The resulting measure appears well behaved, but differs noticeably from a number of published measures.

    Exact zero-point energy shift in the e(n E)e\otimes (n~E), t(n H)t\otimes (n~H) many modes dynamic Jahn-Teller systems at strong coupling

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    We find the exact semiclassical (strong coupling) zero-point energy shifts applicable to the e(nE)e\otimes (n E) and t(nH)t\otimes (n H) dynamic Jahn-Teller problems, for an arbitrary number nn of discrete vibrational modes simultaneously coupled to one single electronic level. We also obtain an analytical formula for the frequency of the resulting normal modes, which has an attractive and apparently general Slater-Koster form. The limits of validity of this approach are assessed by comparison with O'Brien's previous effective-mode approach, and with accurate numerical diagonalizations. Numerical values obtained for t(nH)t\otimes (n H) with n=8n =8 and coupling constants appropriate to C60_{60}^- are used for this purpose, and are discussed in the context of fullerene.Comment: 20 pages, 4 ps figure

    Liver Adiposity and Metabolic Profile in Individuals with Chronic Spinal Cord Injury

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    Purpose. To quantify liver adiposity using magnetic resonance imaging (MRI) and to determine its association with metabolic profile in men with spinal cord injury (SCI). Materials and Methods. MRI analysis of liver adiposity by fat signal fraction (FSF) and visceral adipose tissue (VAT) was completed on twenty participants. Intravenous glucose tolerance test was conducted to measure glucose effectiveness (g) and insulin sensitivity (i ). Lipid panel, fasting glucose, glycated hemoglobin (HbA1c), and inflammatory cytokines were also analyzed. Results. Average hepatic FSF was 3.7% ± 2.1. FSF was positively related to TG, non-HDL-C, fasting glucose, HbA1c, VAT, and tumor necrosis factor alpha (TNF-). FSF was negatively related to i and testosterone. FSF was positively related to VAT ( = 0.48, = 0.032) and TNF- ( = 0.51, = 0.016) independent of age, level of injury (LOI), and time since injury (TSI). The associations between FSF and metabolic profile were independent of VAT. Conclusions. MRI noninvasively estimated hepatic adiposity in men with chronic SCI. FSF was associated with dysfunction in metabolic profile, central adiposity, and inflammation. Importantly, liver adiposity influenced metabolic profile independently of VAT. These findings highlight the significance of quantifying liver adiposity after SCI to attenuate the development of metabolic disorders

    Private Caregiver Presumption For Elder Caregivers

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    The percentage of older Americans increases each year, with a corresponding percentage increase of those considered the older old. Many older persons will develop chronic conditions, decreasing their ability to manage the activities of daily living and requiring many to move into assisted living facilities or group homes. When surveyed, a majority of people expressed that they wish to age in their own homes, and government programs are increasingly supportive of this option. This is a viable option for many if they have the assistance of private caregivers—who provide a vast array of support services—and essential person-to-person human contact during the last years of life. Not all caregivers are family; many are friends, partners, and former colleagues. Whether family or nonfamily, private caregivers often provide a recipient with self-sufficiency for many years, and for some until death. This Article discusses the statistics of aging and the obstacles faced by private caregivers who suffer economic deprivation as a result of the time and expense expended on behalf of an elder recipient. Presumptions, statutes, and the process of estate devolution work against compensation for a private caregiver. There is far too little recognition of what is contributed when a person feeds, bathes, administers medications, provides companionship, and confronts the bureaucracy meant to help the old. The common sentiment of all caregivers would be that they do it because they feel they must. But upon the death of the recipient, one person should not walk away with the benefits of the decedent’s estate and the other with nothing except the recognition of what they must do and did. To better provide for the equal treatment of private caretakers, this Article posits the creation of a private caretaker presumption in favor of elder caregivers. This presumption would apply to any person who dedicates himself or herself another’s care for a period of time sufficient to engender economic benefit to the recipient’s estate and a concomitant loss to the caregiver. Then, based upon the estate assets available, the parameters of the claim, and defined mitigating factors, a presumption is raised that the caregiver may file a creditor claim against the estate in an amount that would make the caregiver equal to the other objects of the decedent’s bounty. Existing remedies are insufficient; more is needed to promote equity

    Evidence for nonlinear diffusive shock acceleration of cosmic-rays in the 2006 outburst of the recurrent nova RS Ophiuchi

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    Spectroscopic observations of the 2006 outburst of the recurrent nova RS Ophiuchi at both infrared (IR) and X-ray wavelengths have shown that the blast wave has decelerated at a higher rate than predicted by the standard test-particle adiabatic shock-wave model. Here we show that the observed evolution of the nova remnant can be explained by the diffusive shock acceleration of particles at the blast wave and the subsequent escape of the highest energy ions from the shock region. Nonlinear particle acceleration can also account for the difference of shock velocities deduced from the IR and X-ray data. The maximum energy that accelerated electrons and protons can have achieved in few days after outburst is found to be as high as a few TeV. Using the semi-analytic model of nonlinear diffusive shock acceleration developed by Berezhko & Ellison, we show that the postshock temperature of the shocked gas measured with RXTE/PCA and Swift/XRT imply a relatively moderate acceleration efficiency.Comment: Accepted for publication in ApJ

    Heralding two- and four-photon path entanglement on chip

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    Generating quantum entanglement is not only an important scientific endeavor, but will be essential to realizing quantum-enhanced technologies, in particular, quantum-enhanced measurements with precision beyond classical limits. We investigate the heralded generation of multiphoton entanglement for quantum metrology using a reconfigurable integrated waveguide device in which projective measurement of auxiliary photons heralds the generation of path-entangled states. We use four and six-photon inputs, to analyze the heralding process of two- and four-photon NOON states-a superposition of N photons in two paths, capable of enabling phase supersensitive measurements at the Heisenberg limit. Realistic devices will include imperfections; as part of the heralded state preparation, we demonstrate phase superresolution within our chip with a state that is more robust to photon loss

    High-Fidelity Z-Measurement Error Correction of Optical Qubits

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    We demonstrate a quantum error correction scheme that protects against accidental measurement, using an encoding where the logical state of a single qubit is encoded into two physical qubits using a non-deterministic photonic CNOT gate. For the single qubit input states |0>, |1>, |0>+|1>, |0>-|1>, |0>+i|1>, and |0>-i|1> our encoder produces the appropriate 2-qubit encoded state with an average fidelity of 0.88(3) and the single qubit decoded states have an average fidelity of 0.93(5) with the original state. We are able to decode the 2-qubit state (up to a bit flip) by performing a measurement on one of the qubits in the logical basis; we find that the 64 1-qubit decoded states arising from 16 real and imaginary single qubit superposition inputs have an average fidelity of 0.96(3).Comment: 4 pages, 4 figures, comments welcom

    Giant optical Faraday rotation induced by a single electron spin in a quantum dot: Applications to entangling remote spins via a single photon

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    We propose a quantum non-demolition method - giant Faraday rotation - to detect a single electron spin in a quantum dot inside a microcavity where negatively-charged exciton strongly couples to the cavity mode. Left- and right-circularly polarized light reflected from the cavity feels different phase shifts due to cavity quantum electrodynamics and the optical spin selection rule. This yields giant and tunable Faraday rotation which can be easily detected experimentally. Based on this spin-detection technique, a scalable scheme to create an arbitrary amount of entanglement between two or more remote spins via a single photon is proposed.Comment: 5 pages, 3 figure
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