8,412 research outputs found

    Investigation of quantitative measures related to reading disability in a large sample of sib-pairs from the UK

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    We describe a family-based sample of individuals with reading disability collected as part of a quantitative trait loci (QTL) mapping study. Eighty-nine nuclear families (135 independent sib-pairs) were identified through a single proband using a traditional discrepancy score of predicted/actual reading ability and a known family history. Eight correlated psychometric measures were administered to each sibling, including single word reading, spelling, similarities, matrices, spoonerisms, nonword and irregular word reading, and a pseudohomophone test. Summary statistics for each measure showed a reduced mean for the probands compared to the co-sibs, which in turn was lower than that of the population. This partial co-sib regression back to the mean indicates that the measures are influenced by familial factors and therefore, may be suitable for a mapping study. The variance of each of the measures remained largely unaffected, which is reassuring for the application of a QTL approach. Multivariate genetic analysis carried out to explore the relationship between the measures identified a common factor between the reading measures that accounted for 54% of the variance. Finally the familiality estimates (range 0.32–0.73) obtained for the reading measures including the common factor (0.68) supported their heritability. These findings demonstrate the viability of this sample for QTL mapping, and will assist in the interpretation of any subsequent linkage findings in an ongoing genome scan

    Defect formation in superconducting rings: external fields and finite-size effects

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    Consistent with the predictions of Kibble and Zurek, scaling behaviour has been seen in the production of fluxoids during temperature quenches of superconducting rings. However, deviations from the canonical behaviour arise because of finite-size effects and stray external fields. Technical developments, including laser heating and the use of long Josephson tunnel junctions, have improved the quality of data that can be obtained. With new experiments in mind we perform large-scale 3D simulations of quenches of small, thin rings of various geometries with fully dynamical electromagnetic fields, at nonzero externally applied magnetic flux. We find that the outcomes are, in practice, indistinguishable from those of much simpler Gaussian analytical approximations in which the rings are treated as one-dimensional systems and the magnetic field fluctuation-free.Comment: 10 pages, 3 figures, presentation at QFS2012, to appear in JLT

    Nitrogen Acquisition by Annual and Perennial Grass Seedlings: Testing the Roles of Performance and Plasticity to Explain Plant Invasion

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    Differences in resource acquisition between native and exotic plants is one hypothesis to explain invasive plant success. Mechanisms include greater resource acquisition rates and greater plasticity in resource acquisition by invasive exotic species compared to non-invasive natives. We assess the support for these mechanisms by comparing nitrate acquisition and growth of invasive annual and perennial grass seedlings in western North America. Two invasive exotic grasses (Bromus tectorum and Taeniatherum caput-medusae) and three perennial native and exotic grasses (Pseudoroegneria spicata, Elymus elymoides, and Agropyron cristatum) were grown at various temperatures typical of autumn and springtime when resource are abundant and dominance is determined by rapid growth and acquisition of resources. Bromus tectorum and perennial grasses had similar rates of nitrate acquisition at low temperature, but acquisition by B. tectorum significantly exceeded perennial grasses at higher temperature. Consequently, B. tectorum had the highest acquisition plasticity, showcasing its ability to take advantage of transient warm periods in autumn and spring. Nitrate acquisition by perennial grasses was limited either by root production or rate of acquisition per unit root mass, suggesting a trade-off between nutrient acquisition and allocation of growth to structural tissues. Our results indicate the importance of plasticity in resource acquisition when temperatures are warm such as following autumn emergence by B. tectorum. Highly flexible and opportunistic nitrate acquisition appears to be a mechanism whereby invasive annual grasses exploit soil nitrogen that perennials cannot use

    Nucleation and growth control in protein crystallization

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    The five topics summarized in this final report are as follows: (1) a technique for the expedient, semi-automated determination of protein solubilities as a function of temperature and application of this technique to proteins other than lysozyme; (2) a small solution cell with adjustable temperature gradients for the growth of proteins at a predetermined location through temperature programming; (3) a microscopy system with image storage and processing capability for high resolution optical studies of temperature controlled protein growth and etching kinetics; (4) growth experiments with lysozyme in thermosyphon flow ; and (5) a mathematical model for the evolution of evaporation/diffusion induced concentration gradients in the hanging drop protein crystallization technique

    On the Average Comoving Number Density of Halos

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    I compare the numerical multiplicity function given in Yahagi, Nagashima & Yoshii (2004) with the theoretical multiplicity function obtained by means of the excursion set model and an improved version of the barrier shape obtained in Del Popolo & Gambera (1998), which implicitly takes account of total angular momentum acquired by the proto-structure during evolution and of a non-zero cosmological constant. I show that the multiplicity function obtained in the present paper, is in better agreement with Yahagi, Nagashima & Yoshii (2004) simulations than other previous models (Sheth & Tormen 1999; Sheth, Mo & Tormen 2001; Sheth & Tormen 2002; Jenkins et al. 2001) and that differently from some previous multiplicity function models (Jenkins et al. 2001; Yahagi, Nagashima & Yoshii 2004) it was obtained from a sound theoretical background

    Relevance of lactate level detection in migrane and fibromyalgia

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    The aim of this study was to determine the blood lactate levels in healthy and pathological subjects, particularly with migraine and fibromyalgia. Moreover we investigated the possible correlation between lactate concentration, postural stability and balance disorders; the composition of the groups were: migraine (n = 25; age 49.7 +/- 12.5), fibromyalgia (n = 10; age 43.7 +/- 21.2), control group (n = 16 age 28.52 +/- 2.4). The results showed that patients with fibromyalgia (FG) had higher lactate levels compared to migraine (MG) and control group (CG) (mean +/- sd: FG = 1.78 +/- 0.9 mmol/L; MG = 1.45 +/- 1 mmol/L; CG = 0,85 +/- 0,07 mmol/L). The same situation was highlighted about the sway path length with eyes closed (FG = 518 +/- 195 mm; MG = 465 +/- 165 mm; CG = 405 +/- 94,72 mm) and with eyes open (FG = 430 +/- 220 mm; MG = 411 +/- 143 mm; CG = 389 +/- 107 mm). This can be explained by the fact that energy-intensive postural strategies must be used to optimize both static and dynamic coordination, in particular with repeated contractions of tonic oxidative muscle cells responsible for postural control

    Planar Josephson Tunnel Junctions in a Transverse Magnetic Field

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    Traditionally, since the discovery of the Josephson effect in 1962, the magnetic diffraction pattern of planar Josephson tunnel junctions has been recorded with the field applied in the plane of the junction. Here we discuss the static junction properties in a transverse magnetic field where demagnetization effects imposed by the junction geometry and configuration of the electrodes are important. Measurements of the critical current versus magnetic field in planar Nb-based high-quality junctions with different geometry, size and critical current density show that it is advantageous to use a transverse magnetic field rather than an in-plane field to suppress the Josephson tunnel current and Fiske resonances in practical applications.Comment: 5 pages, 2 figures, submitted to Journal of Applied Physic

    Comparative analysis of US real-world dosing patterns and direct infusion-related costs for matched cohorts of rheumatoid arthritis patients treated with infliximab or intravenous golimumab.

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    Purpose: The objectives of this study were to evaluate and compare treatment patterns and infusion-related health care resource expenditures for rheumatoid arthritis (RA) patients initiating golimumab for intravenous use (GLM-IV) and infliximab (IFX) therapy and to assess cost implications from the commercial perspective. Methods: Adult RA patients with a new episode of GLM-IV or IFX treatment between January 1, 2014 and March 31, 2016 were identified from MarketScan databases and evaluated for maintenance infusion intervals and related costs of treatment. IFX and GLM-IV patients were matched 1:1 on index medication treatment duration, gender, payer type, prior biologic use, and post-index methotrexate use. Paid amounts for drugs and associated administration costs were applied to treatment group dosing patterns. Results: Final matched treatment groups included 547 GLM-IV and 547 IFX patients (mean age = 55-56 years). Mean (SD) follow-up was 609 (161) days for GLM-IV and 613 (163) days for IFX. Treatment duration was 396 (240) days for GLM-IV and 397 (239) days for IFX. Overall, 80% of GLM-IV and 39% of IFX maintenance infusions were given approximately every 8 weeks; and 6% of GLM-IV and 53% of IFX maintenance infusions occurred more frequently than every 8 weeks (P\u3c0.001). When weighting of the maintenance infusion interval was applied, the mean number of induction plus maintenance infusions during the first year of treatment was estimated at 7.03 for GLM-IV and 9.48 for IFX. From the commercial perspective, drug plus administration costs per infusion were 5,846forGLM−IVand5,846 for GLM-IV and 5,444 for IFX with total annual cost of therapy for GLM-IV patients costing 10,507lessthanthatforIFXpatientsinthefirstyearand10,507 less than that for IFX patients in the first year and 6,774 less than that for IFX patients in subsequent years. Conclusion: Annual GLM-IV drug plus administration costs for commercial health plans were significantly less than IFX in RA patients due to differences in real-world dosing and administration. © 2019 Ellis et al

    Zurek-Kibble Mechanism for the Spontaneous Vortex Formation in Nb−Al/Alox/NbNb-Al/Al_{ox}/Nb Josephson Tunnel Junctions: New Theory and Experiment

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    New scaling behavior has been both predicted and observed in the spontaneous production of fluxons in quenched Nb−Al/Alox/NbNb-Al/Al_{ox}/Nb annular Josephson tunnel junctions as a function of the quench time, τQ\tau_{Q}. The probability f1f_{1} to trap a single defect during the N-S phase transition clearly follows an allometric dependence on τQ\tau_{Q} with a scaling exponent σ=0.5\sigma = 0.5, as predicted from the Zurek-Kibble mechanism for {\it realistic} JTJs formed by strongly coupled superconductors. This definitive experiment replaces one reported by us earlier, in which an idealised model was used that predicted σ=0.25\sigma = 0.25, commensurate with the then much poorer data. Our experiment remains the only condensed matter experiment to date to have measured a scaling exponent with any reliability.Comment: Four pages, one figur
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