955 research outputs found

    Dissipate locally, couple globally: a sharp transition from decoupling to infinite range coupling in Josephson arrays with on-site dissipation

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    We study the T=0 normal to superconducting transition of Josephson arrays with {\it on-site} dissipation. A perturbative renormalization group solution is given. Like the previously studied case of {\it bond} dissipation (BD), this is a "floating" to coupled (FC) phase transition. {\it Unlike} the BD transition, at which {\it only} nearest-neighbor couplings become relevant, here {\it all} inter-grain couplings, out to {\it infinitely} large distances, do so simultaneously. We predict, for the first time in an FC transition, a diverging spatial correlation length. Our results show the robustness of floating phases in dissipative quantum systems.Comment: 7+ pages, 3 eps figures, Europhysics Letters preprint format, as publishe

    Decay of correlations in the dissipative two-state system

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    We study the equilibrium correlation function of the polaron-dressed tunnelling operator in the dissipative two-state system and compare the asymptoptic dynamics with that of the position correlations. For an Ohmic spectral density with the damping strength K=1/2K=1/2, the correlation functions are obtained in analytic form for all times at any TT and any bias. For K<1K<1, the asymptotic dynamics is found by using a diagrammatic approach within a Coulomb gas representation. At T=0, the tunnelling or coherence correlations drop as t−2Kt^{-2K}, whereas the position correlations show universal decay ∝t−2\propto t^{-2}. The former decay law is a signature of unscreened attractive charge-charge interactions, while the latter is due to unscreened dipole-dipole interactions.Comment: 5 pages, 5 figures, to be published in Europhys. Let

    EFFECT OF DIFFERENT LOW BACK TRAINING PROGRAMS ON LUMBAR SPINE KINESTHESIA

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    Reduced kinesthetic perceptions can impair lower back sensorimotor functions and result in increased injury risk. The effect of low back training programs on lumbar spine kinesthetic sensibility is undetermined. There was a back strengthening exercise group (with low back pain; training 4.4 h/wk), a “classical” back training program group (with low back pain; training 4.9 h/wk) and a control group (training 5.4 h/wk). During an active reproduction test, subjects performed trunk positions in random order: flexion [A(0°-20°), B(20°-40°)], lateral flexion [C(0°-30°)], Using a 3D-ultrasound motion analysis system the repositioning error was calculated from the given target position to the subject perceived target position, before and after a 5 week training period. Results show decreased repositioning error after the training for both training groups

    TRUNK POSTURE AND STATICO-DYNAMICAL SPINE ANALYSIS– COMPARING ULTRASOUND BASED VS. OPTICALLY BASED MEASUREMENT SYSTEM

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    The purpose of this study was to compare two different methods measuring trunk posture and statico-dynamical spine analysis. 32 patients participated in this cross sectional study. Comparing measured values a wide congruence could be demonstrated with marginal underestimating in kyphosis and lordosis data for the ultrasound based system. The largest deviation could be shown for pelvic obliquity measured in mm. Trunk inclination, vertical deflection and pelvic obliquity measured in degree showed proper analogy for both measuring systems. Validity, reliability based on particular technical principles could be verified

    CHANGES IN ISOMETRIC AND ISOKINETIC STRENGTH, POSTURAL BALANCE AND ENDURANCE AFTER THAI-BO TRAINING PROGRAM

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    The objective of the present study was to examine the influence of a long term Thai-Bo training program on muscular strength of the knee muscles, postural balance, and cardiovascular parameters. Thirty-five volunteers participated in two groups. Pre-and posttest with measuring of isometric and isokinetic strength of knee extension/flexion as well as postural balance on a force plate were performed before and after a weekly six-months training period. Furthermore cardiovascular parameters were measured during a stepwise increasing cycle ergometry. The results showed a significant increase of isometric strength and isokinetic strength at 600 /s in addition to an improvement in postural balance. Also a significant improvement of cardiovascular parameters in retest could be demonstrated

    PLANTAR PRESSURE MEASUREMENTS IN A SOCCER SHOE: CHARACTERIZATION OF SOCCER SPECIFIC MOVEMENTS AND EFFECTS AFTER SIX WEEKS OF AGING

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    The purposes of the study were (i) to characterize in-shoe pressure distribution (PD) measurements during soccer specific movements, (ii) to describe the changes on (PD) after six weeks of aging. 21 experienced male subjects participated in the study. Four different movements (run, cut, sprint and goal shot) were measured on a red cinder surface before and after six weeks of aging. Results showed specific loading characteristics for each movement: Compared to running, the medial part of the foot in cutting, the forefoot in sprinting and the lateral part in kicking were predominantly loaded. Peak pressures increased over 10% after six weeks of use in some high-load areas. Attention should be paid to sprinting and cutting with respect to overuse injuries. Sockliners should be exchanged on a regular basis to maintain a certain amount of cushioning

    SPECIFIC TRAINING CAN IMPROVE SENSORIMOTOR CONTROL IN TYPE 2 DIABETIC PATIENTS

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    Diabetes mellitus often is associated with proprioceptive and sensory deficits as a result of distal diabetic polyneuropathy (DPN). The aim of this prospective controlled longitudinal trial was to evaluate a specific sport intervention program regarding sensorimotor capabilities in type 2 diabetic patients compared to healthy controls. A higher incidence of fall-related injuries is given in the literature (Allet et al.2008; Allet et al 2009)

    Deployment of RDFa, Microdata, and Microformats on the Web – A Quantitative Analysis

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    More and more websites embed structured data describing for instance products, reviews, blog posts, people, organizations, events, and cooking recipes into their HTML pages using markup standards such as Microformats, Microdata and RDFa. This development has accelerated in the last two years as major Web companies, such as Google, Facebook, Yahoo!, and Microsoft, have started to use the embedded data within their applications. In this paper, we analyze the adoption of RDFa, Microdata, and Microformats across the Web. Our study is based on a large public Web crawl dating from early 2012 and consisting of 3 billion HTML pages which originate from over 40 million websites. The analysis reveals the deployment of the different markup standards, the main topical areas of the published data as well as the different vocabularies that are used within each topical area to represent data. What distinguishes our work from earlier studies, published by the large Web companies, is that the analyzed crawl as well as the extracted data are publicly available. This allows our ïŹndings to be veriïŹed and to be used as starting points for further domain-speciïŹc investigations as well as for focused information extraction endeavors

    Comparative genomics in chicken and Pekin duck using FISH mapping and microarray analysis

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    BACKGROUND: The availability of the complete chicken (Gallus gallus) genome sequence as well as a large number of chicken probes for fluorescent in-situ hybridization (FISH) and microarray resources facilitate comparative genomic studies between chicken and other bird species. In a previous study, we provided a comprehensive cytogenetic map for the turkey (Meleagris gallopavo) and the first analysis of copy number variants (CNVs) in birds. Here, we extend this approach to the Pekin duck (Anas platyrhynchos), an obvious target for comparative genomic studies due to its agricultural importance and resistance to avian flu. RESULTS: We provide a detailed molecular cytogenetic map of the duck genome through FISH assignment of 155 chicken clones. We identified one inter- and six intrachromosomal rearrangements between chicken and duck macrochromosomes and demonstrated conserved synteny among all microchromosomes analysed. Array comparative genomic hybridisation revealed 32 CNVs, of which 5 overlap previously designated "hotspot" regions between chicken and turkey. CONCLUSION: Our results suggest extensive conservation of avian genomes across 90 million years of evolution in both macro- and microchromosomes. The data on CNVs between chicken and duck extends previous analyses in chicken and turkey and supports the hypotheses that avian genomes contain fewer CNVs than mammalian genomes and that genomes of evolutionarily distant species share regions of copy number variation ("CNV hotspots"). Our results will expedite duck genomics, assist marker development and highlight areas of interest for future evolutionary and functional studies
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