207 research outputs found

    TRADE-OFFS BETWEEN SEVERANCE TAX REVENUES AND COAL MINING EMPLOYMENT

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    A severance tax can provide local jurisdictions with additional revenues to finance economic development, yet the imposition of a tax may create coal industry employment losses. This research analyzes this issue by examining the demand for Pennsylvania steam coal, providing estimates of the unconditional own-price elasticities of demand for coal in each of two demand regions. These estimates in conjunction with labor/output coefficient estimates are used to determine the extent to which coal employment in a region already witnessing slow mining industry growth will be negatively affected.Labor and Human Capital, Public Economics,

    Space, Government Payments, and Off-Farm Labor Response of Principal Farm Operators: A County-Level Analysis

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    We examine the effects of space and government payments on off-farm employment among principal farm operators for the entire US as well as for ERS/USDA farm resource regions. Spatial dependency in off-farm employment of principal farm operators in the U.S. overall is evident; however, this is not the case for all farm resource regions. While the effects of government payments overall are significant for the U.S., important variations exist by farm program type and across ERS/USDA regions.government payments, off-farm employment, off-farm labor supply, spatial dependence, ERS regions, Farm Management,

    Maternal Human Capital and Childhood Stunting In Nepal: A Multi-Level Modeling Approach

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    Childhood stunting among preschool-age children stands as a serious public health problem to be addressed in Nepal. Applying the multi-level modeling approach to nationally representative data, in the overall, we provide evidence that the negative influence of maternal own education to childhood stunting occurs especially for mother's higher level of education, but there exists substantial residential variations. Most interestingly, we provide new evidence of a strong negative community externality of maternal education on childhood stunting, even if mothers of children are uneducated. We also find mother's height is negatively related to childhood stunting, regardless of mother's educational attainment and place of residence, providing evidence of intergenerational transmission of maternal health.Health Economics and Policy, Labor and Human Capital,

    MEASURING THE PRIMARY IMPACTS OF SEVERANCE TAXATION: A SPATIAL EQUILIBRIUM APPROACH

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    A spatial equilibrium model is used to quantify the effects of a severance tax on the Pennsylvania coal market. Two regions are identified: the Pennsylvania Market Area and an import/export region. The impacts on prices and quantities of coal supplied and demanded are found to be small. Little of the tax is exported from Pennsylvania, with a high proportion of the tax being passed back to Pennsylvania coal producers. Although the tax revenue exceeds the welfare losses in Pennsylvania, this result is very sensitive to the magnitude of the Pennsylvania own-price demand elasticity.Public Economics,

    Absorption and photoluminescence spectroscopy on a single self-assembled charge-tunable quantum dot

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    We have performed detailed photoluminescence (PL) and absorption spectroscopy on the same single self-assembled quantum dot in a charge-tunable device. The transition from neutral to charged exciton in the PL occurs at a more negative voltage than the corresponding transition in absorption. We have developed a model of the Coulomb blockade to account for this observation. At large negative bias, the absorption broadens as a result of electron and hole tunneling. We observe resonant features in this regime whenever the quantum dot hole level is resonant with two-dimensional hole states located at the capping layer-blocking barrier interface in our structure.Comment: 6 pages, 6 figure

    Tunable Indistinguishable Photons From Remote Quantum Dots

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    Single semiconductor quantum dots have been widely studied within devices that can apply an electric field. In the most common system, the low energy offset between the InGaAs quantum dot and the surrounding GaAs material limits the magnitude of field that can be applied to tens of kVcm^-1, before carriers tunnel out of the dot. The Stark shift experienced by the emission line is typically 1 meV. We report that by embedding the quantum dots in a quantum well heterostructure the vertical field that can be applied is increased by over an order of magnitude whilst preserving the narrow linewidths, high internal quantum efficiencies and familiar emission spectra. Individual dots can then be continuously tuned to the same energy allowing for two-photon interference between remote, independent, quantum dots

    Spin-based all-optical quantum computation with quantum dots: understanding and suppressing decoherence

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    We present an all-optical implementation of quantum computation using semiconductor quantum dots. Quantum memory is represented by the spin of an excess electron stored in each dot. Two-qubit gates are realized by switching on trion-trion interactions between different dots. State selectivity is achieved via conditional laser excitation exploiting Pauli exclusion principle. Read-out is performed via a quantum-jump technique. We analyze the effect on our scheme's performance of the main imperfections present in real quantum dots: exciton decay, hole mixing and phonon decoherence. We introduce an adiabatic gate procedure that allows one to circumvent these effects, and evaluate quantitatively its fidelity

    Probing Single-Electron Spin Decoherence in Quantum Dots using Charged Excitons

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    We propose to use optical detection of magnetic resonance (ODMR) to measure the decoherence time T_{2} of a single electron spin in a semiconductor quantum dot. The electron is in one of the spin 1/2 states and a circularly polarized laser can only create an optical excitation for one of the electron spin states due to Pauli blocking. An applied electron spin resonance (ESR) field leads to Rabi spin flips and thus to a modulation of the photoluminescence or, alternatively, of the photocurrent. This allows one to measure the ESR linewidth and the coherent Rabi oscillations, from which the electron spin decoherence can be determined. We study different possible schemes for such an ODMR setup, including cw or pulsed laser excitation.Comment: 8 pages, 7 figures. Proceedings of the PASPS3 conference, Santa Barbara, CA (USA). To appear in the Journal of Superconductivit

    "Fighting the system": Families caring for ventilator-dependent children and adults with complex health care needs at home

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    <p>Abstract</p> <p>Background</p> <p>An increasing number of individuals with complex health care needs now receive life-long and life-prolonging ventilatory support at home. Family members often take on the role of primary caregivers. The aim of this study was to explore the experiences of families giving advanced care to family members dependent on home mechanical ventilation.</p> <p>Methods</p> <p>Using qualitative research methods, a Grounded Theory influenced approach was used to explore the families' experiences. A total of 15 family members with 11 ventilator-dependent individuals (three children and eight adults) were recruited for 10 in-depth interviews.</p> <p>Results</p> <p>The core category, "fighting the system," became the central theme as family members were asked to describe their experiences. In addition, we identified three subcategories, "lack of competence and continuity", "being indispensable" and "worth fighting for". This study revealed no major differences in the families' experiences that were dependent on whether the ventilator-dependent individual was a child or an adult.</p> <p>Conclusions</p> <p>These findings show that there is a large gap between family members' expectations and what the community health care services are able to provide, even when almost unlimited resources are available. A number of measures are needed to reduce the burden on these family members and to make hospital care at home possible. In the future, the gap between what the health care can potentially provide and what they can provide in real life will rapidly increase. New proposals to limit the extremely costly provision of home mechanical ventilation in Norway will trigger new ethical dilemmas that should be studied further.</p

    Home mechanical ventilation and specialised health care in the community: Between a rock and a hard place

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    <p>Abstract</p> <p>Background</p> <p>Home mechanical ventilation probably represents the most advanced and complicated type of medical treatment provisioned outside a hospital setting. The aim of this study was both to explore the challenges experienced by health care professionals in community health care services when caring for patients dependent on home mechanical ventilation, continual care and highly advanced technology, and their proposed solutions to these challenges.</p> <p>Methods</p> <p>Using qualitative research methods, a grounded theory influenced approach was used to explore the respondents' experiences and proposed solutions. A total of 34 multidisciplinary respondents from five different communities in Norway were recruited for five focus groups.</p> <p>Results</p> <p>The core category in our findings was what health care professionals in community health care services experience as "between a rock and a hard place," when working with hospitals, family members, and patients. We further identified four subcategories, "to be a guest in the patient's home," "to be accepted or not," "who decides," and "how much can we take." The main background for these challenges seems to stem from patients living and receiving care in their private homes, which often leads to conflicts with family members. These challenges can have a negative effect on both the community health caregivers' work environment and the community health service's provision of professional care.</p> <p>Conclusions</p> <p>This study has identified that care of individuals with complex needs and dependent on home mechanical ventilation presents a wide range of immense challenges for community health care services. The results of this study point towards a need to define the roles of family caregivers and health care professionals and also to find solutions to improve their collaboration. The need to improve the work environment for caregivers directly involved in home-care also exists. The study also shows the need for more dialogue concerning eligibility requirements, rights, and limitations of patients in the provision and use of ventilatory support in private homes.</p
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