2,130 research outputs found

    Development of a Conceptual Framework and Calibrated Item Banks to Measure Patient-Reported Dyspnea Severity and Related Functional Limitations

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    AbstractObjectivesChronic obstructive pulmonary disease is a major global health problem. Although several patient-reported outcome (PRO) measures of chronic obstructive pulmonary disease exist, none were developed using patient-driven concept development. We developed an item bank for dyspnea severity and related functional limitations on the basis of a PRO conceptual framework derived from patient input.MethodsWe identified a large pool of existing items based on a conceptual framework and literature review. Using patient and expert review panels and an item refinement/modification process, we developed an item bank aligned with the conceptual framework, which subsequently underwent psychometric testing via an online Internet panel of dyspnea patients (N = 608).ResultsExploratory factor analysis suggested a dominant first factor accounting for about 78% of the total variance. Confirmatory factor analysis supported a unidimensional model. Item response theory analysis demonstrated good model fit, and differential item functioning analyses indicated that the 33-item scale showed potential for measurement equivalence across sex. A 10-item short form produced comparable scores (r = 0.98) and a computerized adaptive-testing simulation indicated efficient measurement with fewer items (mean 4.65 items).ConclusionsAn efficient patient-reported measure of dyspnea severity and related functional limitations, based on a patient-driven PRO conceptual framework, is now available for further validation and use

    Stochastic background from extra-galactic double neutron stars

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    We present Monte Carlo simulations of the extra galactic population of inspiralling double neutron stars, and estimate its contribution to the astrophysical gravitational wave background, in the frequency range of ground based interferometers, corresponding to the last thousand seconds before the last stable orbit when more than 96 percent of the signal is released. We show that sources at redshift z>0.5 contribute to a truly continuous background which may be detected by correlating third generation interferometers.Comment: 13 pages, 7 figures - proceeding of a talk given at the 11th GWDAW, to appear in CQ

    Optical response of a misaligned and suspended Fabry-Perot cavity

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    The response to a probe laser beam of a suspended, misaligned and detuned optical cavity is examined. A five degree of freedom model of the fluctuations of the longitudinal and transverse mirror coordinates is presented. Classical and quantum mechanical effects of radiation pressure are studied with the help of the optical stiffness coefficients and the signals provided by an FM sideband technique and a quadrant detector, for generic values of the product ϖτ\varpi \tau of the fluctuation frequency times the cavity round trip. A simplified version is presented for the case of small misalignments. Mechanical stability, mirror position entanglement and ponderomotive squeezing are accommodated in this model. Numerical plots refer to cavities under test at the so-called Pisa LF facility.Comment: 14 pages (4 figures) submitted to Phys. Rev.

    Adhesive mechanisms governing interferon-producing cell recruitment into lymph nodes

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    Natural interferon-producing cells (IPCs) are found in peripheral lymph nodes (PLNs), where they support NK cell, T cell, and B cell responses to pathogens. However, their route of entry and the adhesive mechanisms used to gain access to PLNs remain poorly defined. We report that IPCs can enter PLNs via a hematogenous route, which involves a multistep adhesive process, and that transmigration is enhanced by inflammation. Results indicate that L-selectin on IPCs is required for efficient attachment and rolling on high endothelial venules in vivo in both nonstimulated and inflamed PLNs. IPCs, however, also possess functional ligands for E-selectin that contribute to this process only in the latter case. In conjunction with selectin-mediated adhesion, both β1- and β2-integrins participate in IPC attachment to the inflamed vessel wall, whereas chemotaxis relies in part on the chemokine receptor CCR5. Identification of the adhesive machinery required for IPC trafficking into PLNs may provide opportunities to regulate immune responses reliant on the activity of these cells

    Impact of dried brewers’ grains supplementation on performance, metabolism and meat quality of broiler chickens

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    The objective was to evaluate increasing levels of dried brewers’ grains (DBG) in feed for broiler chickens from 1 to 21 days old and their effect on performance, blood parameters, intestinal morphometry, carcass characteristics and meat quality. The design was completely randomized with six treatments, which consisted of various levels of DBG inclusion, namely 0 (no inclusion), 20, 40, 60, 80, and 100 g/kg with seven replications and 17 animals per experimental unit, totalling 714 male broilers. Performance parameters, blood biochemical profile, morphology of the intestinal epithelium (duodenum), and carcass yield and composition were evaluated. Feed intake was not changed by DBG inclusion levels. Nor were weight gain and feed conversion ratio. Serum cholesterol levels were not influenced, and there were no effects on triglyceride, uric acid and creatinine levels. Enzyme aspartate aminotransferase showed a quadratic effect, as did alanine aminotransferase, with higher values at 79.5 and 63.9 g/kg DBG inclusion, respectively. No changes in carcass yield and relative organ weight were observed. The composition of the carcass in ether extract showed a quadratic effect, as fat deposition rate, with lowest values at 62.8 and 62.4 g/kg of DBG inclusion levels, respectively. Crude protein levels in carcass reduced linearly, as did fat deposition rate. The parameters of intestinal morphology and meat quality were not changed. Dried brewers’ grains can be included in broiler diet from 1 to 21 days at levels up to 100 g/kg without influencing the metabolic parameters and broiler performance. Keywords: alternative feed, blood, by-product, intestinal villi, performanc

    Population dynamics of HCV subtypes in injecting drug‐users on methadone maintenance treatment in China associated with economic and health reform

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    The extensive genetic heterogeneity of hepatitis C virus (HCV) requires in-depth understanding of the population dynamics of different viral subtypes for more effective control of epidemic outbreaks. We analyzed HCV sequences data from 125 participants in Wuhan, China. These participants were newly infected by subtype 1b (n=13), 3a (n=15), 3b (n=50), and 6a (n=39) while on methadone maintenance treatment (MMT). Bayesian phylogenies and demographic histories were inferred for these subtypes. Participants infected with HCV-1b and 3a were clustered in well-supported monophyletic clades, indicating local sub-epidemics. Subtypes 3b and 6a strains were intermixed with other Chinese isolates, as well as isolates from other Asian countries, reflecting ongoing across geographic boundary transmissions. Subtypes 1b and 3a declined continuously during the past ten years, consistent with the health and economic reform in China, while subtype 3b showed ongoing exponential growth and 6a was characterized by several epidemic waves, possibly related to the recently growing number of travelers between China and other Asian countries. In conclusion, results of this study suggest that HCV subtype 3b and 6a sub-epidemics in China are currently not under control, and new epidemic waves may emerge given the rapid increase in international traveling following substantial economic growth. This article is protected by copyright. All rights reserved

    On line power spectra identification and whitening for the noise in interferometric gravitational wave detectors

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    In this paper we address both to the problem of identifying the noise Power Spectral Density of interferometric detectors by parametric techniques and to the problem of the whitening procedure of the sequence of data. We will concentrate the study on a Power Spectral Density like the one of the Italian-French detector VIRGO and we show that with a reasonable finite number of parameters we succeed in modeling a spectrum like the theoretical one of VIRGO, reproducing all its features. We propose also the use of adaptive techniques to identify and to whiten on line the data of interferometric detectors. We analyze the behavior of the adaptive techniques in the field of stochastic gradient and in the Least Squares ones.Comment: 28 pages, 21 figures, uses iopart.cls accepted for pubblication on Classical and Quantum Gravit

    Exact αs\alpha _s Calculation of bs+γb\rightarrow s + \gamma , \ bs+gb\rightarrow s + g

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    We present an exact αs\alpha_s calculation of the Wilson coefficients associated with the dipole moment operators. We also give an estimate of the branching ratio for bsγb\rightarrow s \gamma. We find that higher dimensional effects are under control within 9%9\% for BR(bsγ)=(4.3±0.37)×104BR(b\rightarrow s \gamma)=(4.3\pm 0.37 )\times 10^{-4}.Comment: 12 pages (plain TeX), 2 postscript figures available upon request. UM-TH-93-20 , IP-ASTP-29-9

    Exclusive B --> K^* l^+ l^-$ decay in the three Higgs doublet model

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    We study the differential Branching ratio and CP asymmetry for the exclusive decay B --> K^* l^+ l^- in the three Higgs doublet model with additional global O(2) symmetry in the Higgs sector. We analyse dilepton mass square q^2 dependency of the these quantities. Further, we study the effect of new parameter of the global symmetry in the Higgs sector on the differential branching ratio and CP asymmetry. We see that there exist an enhancement in the branching ratio and a considerable CP violation for the relevant process. In addition to this, we realize that fixing dilepton mass gives information about the sign of the Wilson coefficient C_7^{eff}.Therefore, the future measurements of the CP asymmetry for B\to K^* l^+ l^- decay will give a powerful information about the sign of Wilson coefficient C_{7}^{eff} and new physics beyond the SM.Comment: 19 pages, 6 figure
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