6,466 research outputs found
Primary Care Validation of a Single-Question Alcohol Screening Test
BACKGROUND
Unhealthy alcohol use is prevalent but under-diagnosed in primary care settings.
OBJECTIVE
To validate, in primary care, a single-item screening test for unhealthy alcohol use recommended by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).
DESIGN
Cross-sectional study.
PARTICIPANTS
Adult English-speaking patients recruited from primary care waiting rooms.
MEASUREMENTS
Participants were asked the single screening question, "How many times in the past year have you had X or more drinks in a day?", where X is 5 for men and 4 for women, and a response of >1 is considered positive. Unhealthy alcohol use was defined as the presence of an alcohol use disorder, as determined by a standardized diagnostic interview, or risky consumption, as determined using a validated 30-day calendar method.
MAIN RESULTS
Of 394 eligible primary care patients, 286 (73%) completed the
interview. The single-question screen was 81.8% sensitive (95% confidence interval (CI) 72.5% to 88.5%) and 79.3% specific (95% CI 73.1% to 84.4%) for the detection of unhealthy alcohol use. It was slightly more sensitive (87.9%, 95% CI 72.7% to 95.2%) but was less specific (66.8%, 95% CI 60.8% to 72.3%) for the detection of a current alcohol use disorder. Test characteristics were similar to that of a commonly used three-item screen, and were affected very little by subject demographic characteristics.
CONCLUSIONS. The single screening question recommended by the NIAAA accurately identified unhealthy alcohol use in this sample of primary care patients. These findings support the use of this brief screen in primary care.National Institute on Alcohol Abuse and Alcoholism (R01-AA010870
Ba\u3csub\u3e8\u3c/sub\u3eZnTa\u3csub\u3e6\u3c/sub\u3eO\u3csub\u3e24\u3c/sub\u3e: A New High Q Dielectric Perovskite
The hexagonal perovskite, Ba8ZnTa6O24, was prepared in single-phase form and was found to be a stable secondary phase, formed as a result of the loss of ZnO from Ba(Zn1/3Ta2/3)O3 microwave dielectrics. The experimental and calculated X-ray patterns of Ba8ZnTa6O24 indicate it is isostructural with Ba8Ta6NiO24 with an 8H (cchc)2 close-packed BaO3 stacking sequence and the lattice parameters, a=10.0825(14), c=19.0587 (38)Å . High-density ceramics of Ba8ZnTa6O24 could be prepared at temperatures considerably lower (1400ºC) than those used to sinter pure Ba(Zn1/3Ta2/3)O3, and exhibit very good microwave dielectric properties with ε=30.5, Qf=62300, and τf=+36 ppm/ºC at 8.9 GHz
B Decays on the Lattice and Results for Phenomenology
Lattice Monte Carlo simulations now include the effects of 2 light sea quarks
and 1 strange sea quark through the use of an improved staggered fermion
action. Consequently, results important to phenomenology are free of the
approximate 10% errors inherent in the quenched approximation. This talk
reports on calculations of the B and Bs decay constants and B -> pi l nu form
factors. Accurate determinations of these quantities will lead to tighter
constraints on CKM matrix elements.Comment: Contributed to the Proceedings of American Physical Society's 2004
Meeting of the Division of Particles and Fields (DPF2004), Riverside, CA,
26-31 August 2004. 3 page
Decoherence-free quantum-information processing using dipole-coupled qubits
We propose a quantum-information processor that consists of decoherence-free
logical qubits encoded into arrays of dipole-coupled qubits. High-fidelity
single-qubit operations are performed deterministically within a
decoherence-free subsystem without leakage via global addressing of bichromatic
laser fields. Two-qubit operations are realized locally with four physical
qubits, and between separated logical qubits using linear optics. We show how
to prepare cluster states using this method. We include all
non-nearest-neighbor effects in our calculations, and we assume the qubits are
not located in the Dicke limit. Although our proposal is general to any system
of dipole-coupled qubits, throughout the paper we use nitrogen-vacancy (NV)
centers in diamond as an experimental context for our theoretical results.Comment: 7 pages, 5 figure
Predicting morphotropic phase boundary locations and transition temperatures in Pb- and Bi-based perovskite solid solutions from crystal chemical data and first-principles calculations
Using data obtained from first-principles calculations, we show that the
position of the morphotropic phase boundary (MPB) and transition temperature at
MPB in ferroelectric perovskite solutions can be predicted with quantitative
accuracy from the properties of the constituent cations. We find that the mole
fraction of PbTiO at MPB in Pb(BB)O-PbTiO,
BiBO-PbTiO and Bi(BB)O-PbTiO exhibits a linear
dependence on the ionic size (tolerance factor) and the ionic displacements of
the B-cations as found by density functional theory calculations. This
dependence is due to competition between the local repulsion and A-cation
displacement alignment interactions. Inclusion of first-principles displacement
data also allows accurate prediction of transiton temperatures at the MPB. The
obtained structure-property correlations are used to predict morphotropic phase
boundaries and transition temperatures in as yet unsynthesized solid solutions.Comment: Accepted for publication in J. Appl. Phy
Deployment and Impact of Support Staff in Schools : The Impact of Support Staff in Schools (Results from Strand 2, Wave 2)
This study was designed to obtain up to date and reliable data on the deployment and characteristics of support staff and the impact of support staff on pupil outcomes and teacher workloads. The study covered schools in England and Wales. It involved large scale surveys (Strand 1), followed by a multi-method and multi informant approach (Strand 2). It provided detailed baseline data by which to assess change and progress over time. It sought to understand the processes in schools which lead to the effective use of support staff. The DISS project was funded by the Department for Children, Schools and Families (DCSF) and Welsh Assembly Government (WAG)
Spectral projections and resolvent bounds for partially elliptic quadratic differential operators
We study resolvents and spectral projections for quadratic differential
operators under an assumption of partial ellipticity. We establish
exponential-type resolvent bounds for these operators, including
Kramers-Fokker-Planck operators with quadratic potentials. For the norms of
spectral projections for these operators, we obtain complete asymptotic
expansions in dimension one, and for arbitrary dimension, we obtain exponential
upper bounds and the rate of exponential growth in a generic situation. We
furthermore obtain a complete characterization of those operators with
orthogonal spectral projections onto the ground state.Comment: 60 pages, 3 figures. J. Pseudo-Differ. Oper. Appl., to appear.
Revised according to referee report, including minor changes to Corollary
1.8. The final publication will be available at link.springer.co
The Heavy Quark Self-Energy in Nonrelativistic Lattice QCD
The heavy quark self-energy in nonrelativistic lattice QCD is calculated to
in perturbation theory. An action which includes all
spin-independent relativistic corrections to order , where is the
typical heavy quark velocity, and all spin-dependent corrections to order
is used. The standard Wilson action and an improved multi-plaquette action are
used for the gluons. Results for the mass renormalization, wavefunction
renormalization, and energy shift are given; tadpole contributions are found to
be large. A tadpole improvement scheme in which all link variables are rescaled
by a mean-field factor is also studied. The effectiveness of this scheme in
offsetting the large tadpole contributions to the heavy quark renormalization
parameters is demonstrated.Comment: 28 pages, SLAC-PUB-598
Enhanced Tetragonality in (\u3cem\u3ex\u3c/em\u3e)PbTiO\u3csub\u3e3\u3c/sub\u3e-(1-x)Bi(\u3cem\u3eB′B″\u3c/em\u3e)O\u3csub\u3e3\u3c/sub\u3e systems: Bi(Zn\u3csub\u3e3/4\u3c/sub\u3eWN\u3csub\u3e1/4\u3c/sub\u3e)O\u3csub\u3e3\u3c/sub\u3e
Solid solutions in the (x)PbTiO3–(1−x)Bi(Zn3/4W1/4)O3 system have been examined by x-ray diffraction, dielectric measurements, and thermal analysis. Bi(Zn3/4W1/4)O3increases the tetragonality and Curie temperature of PbTiO3 which reach a value of 1.08 and 530 °C, respectively, at the limit of the single-phase perovskite forming region (x~0.8). The observation of a sustained increase in the tetragonality in this system is similar to the behavior of the (x)PbTiO3–(1−x)Bi(Zn1/2Ti1/2)O3 system and highlights the unique properties of Bi-based systems when the B sites contain high concentrations of highly polarizable cations
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