307 research outputs found
Satisfactory cross cultural equivalence of the Dutch WOMAC in patients with hip osteoarthritis waiting for arthroplasty
Background: Cross cultural validity is of vital importance for international comparisons. Objective: To investigate the validity of international Dutch-English comparisons when using the Dutch translation of the Western Ontario and McMaster Universities osteoarthritis index (WOMAC). Patients and Methods: The dimensionality, reliability, construct validity, and cross cultural equivalence of the Dutch WOMAC in Dutch and Canadian patients waiting for primary total hip arthroplasty was investigated. Unidimensionality and cross cultural equivalence was quantified by principal component and Rasch analysis. Intratest reliability was quantified with Cronbach's α, and test-retest reliability with the intraclass correlation coefficient. Construct validity was quantified by correlating sum scores of the Dutch WOMAC, Arthritis Impact Measurement Scales (Dutch AIMS2), Health Assessment Questionnaire (Dutch HAQ), and Harris Hip Score (Dutch HHS). Results: The WOMAC was completed by 180 Dutch and 244 English speaking Canadian patients. Unidimensionality of the Dutch WOMAC was confirmed by principal component and Rasch analysis (good fit for 20/22 items). The intratest reliability of the Dutch WOMAC for pain and physical functioning was 0.88 and 0.96, whereas the test-retest reliability was 0.77 and 0.92, respectively. Dutch WOMAC pain sum score correlated 0.69 with Dutch HAQ pain, and 0.39 with Dutch HHS pain. Dutch WOMAC physical functioning sum score correlated 0.46 with Dutch AIMS2 mobility, 0.62 with Dutch AIMS2 walking and bending, 0.67 with Dutch HAQ disability, and 0.49 with Dutch HHS function. Differential item functioning (DIF) was shown for 6/22 Dutch items. Conclusions: The Dutch WOMAC permits valid international Dutch-English comparisons after correction for DIF
Effect of Processing on Morphology of Hydroxyapatites: Bioactive Glasses and Crystalline Composites
Recent studies on multinary oxides for applications as laser hosts and high dielectric capacitors have shown that processing at high temperature provides glassy or crystalline materials based on thermal treatments and cooling rates. Since hydroxyapatites are now subject of great interests due to their bioactivity, interest in producing soft and hard materials with glassy and crystalline nature by processing parameters has become very important. Crystalline materials by using Bridgman, Czochralski and flux growth methods are costly and require huge investment. We have observed that even low temperature solidification in organic flux produced oriented fibers. This organic treated material has different characteristics than in situ oxide materials prepared by sintering and grain growth. Examples of phosphate and silicate-based systems will be presented to demonstrate soft and hard materials. Effect of TiO2 and other hardening elements will be also reported
The Synthesis of [{n-Bu2Sn(S2N2)}2] and its use in the preparation of Organometallic Iridium Sulfur Nitrogen Complexes
The addition of [n-Bu2SnCl2] to a solution of [S4N3][Cl] in liquid ammonia gave after extraction of the dry reaction mixture the new tin disulfur dinitrido compound [{n-Bu2Sn(S2N2)}(2)] (1). Reaction of [{n-Bu2Sn(S2N2)}(2)] (1) with the pentamethylcyclopentadienyl (Cp*) iridium derivatives [{IrCl(mu-Cl)(eta(5)-C5Me5)}(2)] or [(eta(5)-C5Me5)IrCl2(PPh3)] gave different products, which were dependent on the reactant ratios. A 1:1 reaction between 1 and [{IrCl(mu-Cl)(eta(5)-C5Me5)}(2)] gave only [(eta(5)-C5Me5)Ir(S2N2)] (2) in moderate yield; the same product in higher yield was obtained from a 2:1 reaction between 1 and [(eta(5)-C5Me5)IrCl2(PPh3)]. Reaction of 1 and [(eta(5)-C5Me5)(2)IrCl2(PPh3)] (1:1 molar ratio) in the presence of NH4[PF6] gave the unusual bimetallic species [(eta(5)-C5Me5)IrCl(PPh3)(S2N2)Ir(eta(5)-C5Me5)][PF6] (3). The X-ray crystal structures of 1, 2, and 3 are reported.PostprintPeer reviewe
Survey of nucleon electromagnetic form factors
A dressed-quark core contribution to nucleon electromagnetic form factors is
calculated. It is defined by the solution of a Poincare' covariant Faddeev
equation in which dressed-quarks provide the elementary degree of freedom and
correlations between them are expressed via diquarks. The nucleon-photon vertex
involves a single parameter; i.e., a diquark charge radius. It is argued to be
commensurate with the pion's charge radius. A comprehensive analysis and
explanation of the form factors is built upon this foundation. A particular
feature of the study is a separation of form factor contributions into those
from different diagram types and correlation sectors, and subsequently a
flavour separation for each of these. Amongst the extensive body of results
that one could highlight are: r_1^{n,u}>r_1^{n,d}, owing to the presence of
axial-vector quark-quark correlations; and for both the neutron and proton the
ratio of Sachs electric and magnetic form factors possesses a zero.Comment: 43 pages, 17 figures, 12 tables, 5 appendice
Q
The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis
Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy
During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly
RANTES/CCL5 and risk for coronary events: Results from the MONICA/KORA Augsburg case-cohort, Athero-express and CARDIoGRAM studies
Background: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. Methods and Findings: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±
The achievable region method in the optimal control of queueing systems; formulations, bounds and policies
Use of >100,000 NHLBI Trans-Omics for Precision Medicine (TOPMed) Consortium whole genome sequences improves imputation quality and detection of rare variant associations in admixed African and Hispanic/Latino populations
Most genome-wide association and fine-mapping studies to date have been conducted in individuals of European descent, and genetic studies of populations of Hispanic/Latino and African ancestry are limited. In addition, these populations have more complex linkage disequilibrium structure. In order to better define the genetic architecture of these understudied populations, we leveraged >100,000 phased sequences available from deep-coverage whole genome sequencing through the multi-ethnic NHLBI Trans-Omics for Precision Medicine (TOPMed) program to impute genotypes into admixed African and Hispanic/Latino samples with genome-wide genotyping array data. We demonstrated that using TOPMed sequencing data as the imputation reference panel improves genotype imputation quality in these populations, which subsequently enhanced gene-mapping power for complex traits. For rare variants with minor allele frequency (MAF) 86%. Subsequent association analyses of TOPMed reference panel-imputed genotype data with hematological traits (hemoglobin (HGB), hematocrit (HCT), and white blood cell count (WBC)) in ~21,600 African-ancestry and ~21,700 Hispanic/Latino individuals identified associations with two rare variants in the HBB gene (rs33930165 with higher WBC [p = 8.8x10-15] in African populations, rs11549407 with lower HGB [p = 1.5x10-12] and HCT [p = 8.8x10-10] in Hispanics/Latinos). By comparison, neither variant would have been genome-wide significant if either 1000 Genomes Project Phase 3 or Haplotype Reference Consortium reference panels had been used for imputation. Our findings highlight the utility of the TOPMed imputation reference panel for identification of novel rare variant associations not previously detected in similarly sized genome-wide studies of under-represented African and Hispanic/Latino populations
Rare genetic variants explain missing heritability in smoking
Common genetic variants explain less variation in complex phenotypes than inferred from family-based studies, and there is a debate on the source of this ‘missing heritability’. We investigated the contribution of rare genetic variants to tobacco use with whole-genome sequences from up to 26,257 unrelated individuals of European ancestries and 11,743 individuals of African ancestries. Across four smoking traits, single-nucleotide-polymorphism-based heritability (hSNP2) was estimated from 0.13 to 0.28 (s.e., 0.10–0.13) in European ancestries, with 35–74% of it attributable to rare variants with minor allele frequencies between 0.01% and 1%. These heritability estimates are 1.5–4 times higher than past estimates based on common variants alone and accounted for 60% to 100% of our pedigree-based estimates of narrow-sense heritability (hped2, 0.18–0.34). In the African ancestry samples, hSNP2 was estimated from 0.03 to 0.33 (s.e., 0.09–0.14) across the four smoking traits. These results suggest that rare variants are important contributors to the heritability of smoking
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