24,823 research outputs found
RURAL-URBAN DIFFERENCES IN NURSING HOME ACCESS, QUALITY AND COST
Rural-urban differences in the supply of nursing home services as hypothesized to be jointly affected by competitive and regulatory forces, government policies, and the cost structure. Study findings indicate that rural services are slightly less accessible and lower in quality. A translog cost share function reveals no difference in the operating cost structure of rural and urban homes. Cost shares for nursing care are directly related to the degree of skilled nursing provided by homes. Significant scale economies were not detected for any of the major operating costs.Rural health care, Nursing homes, Cost structure, Health Economics and Policy,
Coupling Josephson qubits via a current-biased information bus
Josephson qubits without direct interaction can be effectively coupled by
sequentially connecting them to an information bus: a current-biased large
Josephson junction treated as an oscillator with adjustable frequency. The
coupling between any qubit and the bus can be controlled by modulating the
magnetic flux applied to that qubit. This tunable and selective coupling
provides two-qubit entangled states for implementing elementary quantum logic
operations, and for experimentally testing Bell's inequality.Comment: 10 pages, 1 figure. submitte
Vacuum induced Berry phases in single-mode Jaynes-Cummings models
Motivated by the work [Phys. Rev. Lett. 89, 220404 (2002)] for detecting the
vacuum-induced Berry phases with two-mode Jaynes-Cummings models (JCMs), we
show here that, for a parameter-dependent single-mode JCM, certain atom-field
states also acquire the photon-number-dependent Berry phases after the
parameter slowly changed and eventually returned to its initial value. This
geometric effect related to the field quantization still exists, even the filed
is kept in its vacuum state. Specifically, a feasible Ramsey interference
experiment with cavity quantum electrodynamics (QED) system is designed to
detect the vacuum-induced Berry phase.Comment: 10 pages, 4 figures
Generation of nonclassical photon states using a superconducting qubit in a microcavity
Based on the interaction between the radiation field and a superconductor, we
propose a way to engineer quantum states using a SQUID charge qubit inside a
microcavity. This device can act as a deterministic single photon source as
well as generate any Fock states and an arbitrary superposition of Fock states
for the cavity field. The controllable interaction between the cavity field and
the qubit can be realized by the tunable gate voltage and classical magnetic
field applied to the SQUID.Comment: 4 page
Local breaking of four-fold rotational symmetry by short-range magnetic order in heavily overdoped Ba(FeCu)As
We investigate Cu-doped Ba(FeCu)As with transport,
magnetic susceptibility, and elastic neutron scattering measurements. In the
heavily Cu-doped regime where long-range stripe-type antiferromagnetic order in
BaFeAs is suppressed, Ba(FeCu)As (0.145 0.553) samples exhibit spin-glass-like behavior in magnetic
susceptibility and insulating-like temperature dependence in electrical
transport. Using elastic neutron scattering, we find stripe-type short-range
magnetic order in the spin-glass region identified by susceptibility
measurements. The persistence of short-range magnetic order over a large doping
range in Ba(FeCu)As likely arises from local arrangements
of Fe and Cu that favor magnetic order, with Cu acting as vacancies relieving
magnetic frustration and degeneracy. These results indicate locally broken
four-fold rotational symmetry, suggesting that stripe-type magnetism is
ubiquitous in iron pnictides.Comment: accepted by Physical Review B Rapid Communication
Positive surface charge of GluN1 N-terminus mediates the direct interaction with EphB2 and NMDAR mobility.
Localization of the N-methyl-D-aspartate type glutamate receptor (NMDAR) to dendritic spines is essential for excitatory synaptic transmission and plasticity. Rather than remaining trapped at synaptic sites, NMDA receptors undergo constant cycling into and out of the postsynaptic density. Receptor movement is constrained by protein-protein interactions with both the intracellular and extracellular domains of the NMDAR. The role of extracellular interactions on the mobility of the NMDAR is poorly understood. Here we demonstrate that the positive surface charge of the hinge region of the N-terminal domain in the GluN1 subunit of the NMDAR is required to maintain NMDARs at dendritic spine synapses and mediates the direct extracellular interaction with a negatively charged phospho-tyrosine on the receptor tyrosine kinase EphB2. Loss of the EphB-NMDAR interaction by either mutating GluN1 or knocking down endogenous EphB2 increases NMDAR mobility. These findings begin to define a mechanism for extracellular interactions mediated by charged domains
77Se NMR study of pairing symmetry and spin dynamics in KyFe2-xSe2
We present a 77Se NMR study of the newly discovered iron selenide
superconductor KyFe2-xSe2, in which Tc = 32 K. Below Tc, the Knight shift 77K
drops sharply with temperature, providing strong evidence for singlet pairing.
Above Tc, Korringa-type relaxation indicates Fermi-liquid behavior. Our
experimental results set strict constraints on the nature of possible theories
for the mechanism of high-Tc superconductivity in this iron selenide system.Comment: Chemical composition of crystals determined. Accepted in Physical
Review Letter
- …