10,921 research outputs found

    Measuring Health and Broader Well-Being Benefits in the Context of Opiate Dependence: The Psychometric Performance of the ICECAP-A and the EQ-5D-5L

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    BACKGROUND: Measuring outcomes in economic evaluations of social care interventions is challenging because both health and well-being benefits are evident. The ICEpop CAPability instrument for adults (ICECAP-A) and the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) are measures potentially suitable for the economic evaluation of treatments for substance use disorders. Evidence for their validity in this context is, however, lacking. OBJECTIVES: To assess the construct validity of the ICECAP-A and the EQ-5D-5L in terms of convergent and discriminative validity and sensitivity to change on the basis of standard clinical measures (Clinical Outcomes in Routine Evaluation-Outcome Measure, Treatment Outcomes Profile, Interpersonal Support Evaluation List, Leeds Dependence Questionnaire, and Social Satisfaction Questionnaire). METHODS: A secondary analysis of pilot trial data for heroin users in opiate substitution treatment was conducted. Baseline convergence with clinical measures was assessed using the Pearson correlation coefficient. Discriminative validity was assessed using one-way analysis of variance and stepwise regressions. Sensitivity to changes in clinical indicators was assessed at 3 and 12 months using the standardized response mean statistic and parametric and nonparametric testing. RESULTS: Both measures had the same level of construct validity, except for clinical indicators of well-being, for which the ICECAP-A performed better. The ICECAP-A was sensitive to changes in both health and well-being indicators. The EQ-5D-5L had lower levels of sensitivity to change, and a ceiling effect (27%), particularly evident in the dimensions of self-care (89%), mobility (75%), and usual activities (72%). CONCLUSIONS: The findings support the construct validity of both measures, but the ICECAP-A gives more attention to broader impacts and is more sensitive to change. The ICECAP-A shows promise in evaluating treatments for substance use disorders for which recovery is the desired outcome

    Search for supersolidity in 4He in low-frequency sound experiments

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    We present results of the search for supersolid 4He using low-frequency, low-level mechanical excitation of a solid sample grown and cooled at fixed volume. We have observed low frequency non-linear resonances that constitute anomalous features. These features, which appear below about 0.8 K, are absent in 3He. The frequency, the amplitude at which the nonlinearity sets in, and the upper temperature limit of existence of these resonances depend markedly on the sample history.Comment: Submitted to the Quantum Fluids and Solids Conf. Aug. 2006 Kyot

    Zeros of Rydberg-Rydberg Foster Interactions

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    Rydberg states of atoms are of great current interest for quantum manipulation of mesoscopic samples of atoms. Long-range Rydberg-Rydberg interactions can inhibit multiple excitations of atoms under the appropriate conditions. These interactions are strongest when resonant collisional processes give rise to long-range C_3/R^3 interactions. We show in this paper that even under resonant conditions C_3 often vanishes so that care is required to realize full dipole blockade in micron-sized atom samples.Comment: 10 pages, 4 figures, submitted to J. Phys.

    The CMS Tracker Readout Front End Driver

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    The Front End Driver, FED, is a 9U 400mm VME64x card designed for reading out the Compact Muon Solenoid, CMS, silicon tracker signals transmitted by the APV25 analogue pipeline Application Specific Integrated Circuits. The FED receives the signals via 96 optical fibers at a total input rate of 3.4 GB/sec. The signals are digitized and processed by applying algorithms for pedestal and common mode noise subtraction. Algorithms that search for clusters of hits are used to further reduce the input rate. Only the cluster data along with trigger information of the event are transmitted to the CMS data acquisition system using the S-LINK64 protocol at a maximum rate of 400 MB/sec. All data processing algorithms on the FED are executed in large on-board Field Programmable Gate Arrays. Results on the design, performance, testing and quality control of the FED are presented and discussed

    Atomic Spectral Features During Thermonuclear Flashes on Neutron Stars

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    The gravitational redshift measured by Cottam, Paerels and Mendez for the neutron star (NS) in the low-mass X-ray binary EXO 0748-676 depends on the identification of an absorption line during a type I burst as the Hα\alpha line from hydrogenic Fe. We show that Fe is present above the photosphere as long as M˙>4×1013Myr1\dot M>4\times 10^{-13}M_\odot {\rm yr^{-1}} during the burst. In this limit, the total Fe column is NFe3×1019cm2N_{\rm Fe}\approx 3\times 10^{19}{\rm cm^{-2}} for incident material of solar abundances and only depends on the nuclear physics of the proton spallation. The Fe destruction creates many heavy elements with Z<26Z<26 which may imprint photo-ionization edges on the NS spectra during a radius expansion event or in a burst cooling tail. Detecting these features in concert with those from Fe would confirm a redshift measurement. We also begin to address the radiative transfer problem, and find that a concentrated Fe layer with kT=1.21.4keVkT=1.2-1.4 {\rm keV} and column NFe=720×1020cm2N_{\rm Fe}= 7-20 \times 10^{20} {\rm cm}^{-2} (depending on the line depth) above the hotter continuum photosphere is required to create the Hα\alpha line of the observed strength. This estimate must be refined by considerations of non-LTE effects as well as resonant line transport. Until these are carried out, we cannot say whether the Fe column from accretion and spallation is in conflict with the observations. We also show that hydrogenic Fe might remain in the photosphere due to radiative levitation from the high burst flux.Comment: Substantially revised version, to appear in Ap J Letter

    CRTH2 expression on T cells in asthma

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    Mast cell-derived prostaglandin D2 (PGD2) is the major prostanoid found within the airway of asthmatics immediately following allergen challenge. PGD2 has been shown to have chemokinetic effects on eosinophils and T helper type 2 (Th2) cells in vitro. This occurs through the interaction of PGD2 with the G-protein-coupled chemokine receptor homologous molecule expressed on Th2 lymphocytes (CRTH2). The expression of CRTH2 has been shown to be highly selective for Th2 cells. Using flow cytometry we have studied the expression of CRTH2 on T cells in blood and bronchoalveolar lavage fluid in asthmatics and normal subjects. CRTH2 expression was confined to a small percentage of blood T cells in asthmatics (1·8% ± 0·2) and normal (1·6% ± 0·2) subjects. CRTH2 was enriched significantly on interleukin (IL)-4+/IL-13+ T cells compared to interferon (IFN)-γ+ T cells (P < 0·001). There was a small population of CRTH2+ T cells in the bronchoalveolar lavage (BAL) of asthmatics (2·3% ± 0·6) and normal subjects (0·3% ± 0·1), and there was a significant difference between the two groups (P < 0·05). There were similar amounts of PGD2 in the BAL of asthma and normal subjects. Within paired blood–BAL samples from the same subject there was no increase in CRTH2+ T cells in the BAL compared to blood in asthmatics. Enrichment of CRTH2 on IL-4+ and IL-13+ T cells compared to IFN-γ+ T cells was also seen in BAL from asthmatics (P < 0·001). CRTH2 is expressed preferentially by IL-4+/IL-13+ T cells compared to IFN-γ+ T cells. However, given their small numbers they are unlikely to have a significant involvement in the pathogenesis of asthma. CRTH2 antagonism may not diminish T cell accumulation in the asthmatic lung

    Electrochemistry at nanoscale electrodes : individual single-walled carbon nanotubes (SWNTs) and SWNT-templated metal nanowires

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    Individual nanowires (NWs) and native single-walled carbon nanotubes (SWNTs) can be readily used as well-defined nanoscale electrodes (NSEs) for voltammetric analysis. Here, the simple photolithography-free fabrication of submillimeter long Au, Pt, and Pd NWs, with sub-100 nm heights, by templated electrodeposition onto ultralong flow-aligned SWNTs is demonstrated. Both individual Au NWs and SWNTs are employed as NSEs for electron-transfer (ET) kinetic quantification, using cyclic voltammetry (CV), in conjunction with a microcapillary-based electrochemical method. A small capillary with internal diameter in the range 30–70 μm, filled with solution containing a redox-active mediator (FcTMA+ ((trimethylammonium)methylferrocene), Fe(CN)64–, or hydrazine) is positioned above the NSE, so that the solution meniscus completes an electrochemical cell. A 3D finite-element model, faithfully reproducing the experimental geometry, is used to both analyze the experimental CVs and derive the rate of heterogeneous ET, using Butler–Volmer kinetics. For a 70 nm height Au NW, intrinsic rate constants, k0, up to ca. 1 cm s–1 can be resolved. Using the same experimental configuration the electrochemistry of individual SWNTs can also be accessed. For FcTMA+/2+ electrolysis the simulated ET kinetic parameters yield very fast ET kinetics (k0 > 2 ± 1 cm s–1). Some deviation between the experimental voltammetry and the idealized model is noted, suggesting that double-layer effects may influence ET at the nanoscale
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