674 research outputs found

    Universality for 2D Wedge Wetting

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    We study 2D wedge wetting using a continuum interfacial Hamiltonian model which is solved by transfer-matrix methods. For arbitrary binding potentials, we are able to exactly calculate the wedge free-energy and interface height distribution function and, thus, can completely classify all types of critical behaviour. We show that critical filling is characterized by strongly universal fluctuation dominated critical exponents, whilst complete filling is determined by the geometry rather than fluctuation effects. Related phenomena for interface depinning from defect lines in the bulk are also considered.Comment: 4 pages, 1 figur

    Chiral extrapolation of lattice moments of proton quark distributions

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    We present the resolution of a long-standing discrepancy between the moments of parton distributions calculated from lattice QCD and their experimental values. We propose a simple extrapolation formula for the moments of the nonsinglet quark distribution u-d, as a function of quark mass, which embodies the general constraints imposed by the chiral symmetry of QCD. The inclusion of the leading nonanalytic behavior leads to an excellent description of both the lattice data and the experimental values of the moments.Comment: 9 pages, 1 figure, to appear in Physical Review Letter

    Spin-Dependent Twist-Four Matrix Elements from g_1 Data in the Resonance Region

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    Matrix elements of spin-dependent twist-four operators are extracted from recent data on the spin-dependent g_1 structure function of the proton and deuteron in the resonance region. We emphasize the need to include the elastic contributions to the first moments of the structure functions at Q^2 < 2 GeV^2. The coefficients of the 1/Q^2 corrections to the Ellis-Jaffe sum rules are found to be 0.04 \pm 0.02 and 0.03 \pm 0.04 GeV^2 for the proton and neutron, respectively.Comment: 10 pages REVTeX, 4 figure

    Nonperturbative versus perturbative effects in generalized parton distributions

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    Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role of nonperturbative antiquark degrees of freedom and the valence quark contribution. A QCD evolution of the obtained GPDs is used to add perturbative effects and to investigate the GPDs' sensitivity to the nonperturbative ingredients of the calculation at larger (experimental) scale.Comment: 17 pages, 10 figures; submitted to Phys. Rev.

    Ethnic In-Group Favoritism Among Minority and Majority Groups: Testing the Self-Esteem Hypothesis Among Preadolescents

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    The self-esteem hypothesis in intergroup relations, as proposed by social identity theory (SIT), states that successful intergroup discrimination enhances momentary collective self-esteem. This hypothesis is a source of continuing controversy. Furthermore, although SIT is increasingly used to account for children’s group attitudes, few studies have examined the hypothesis among children. In addition, the hypothesis’s generality makes it important to study among children from different ethnic groups. The present study, conducted among Dutch and Turkish preadolescents, examined momentary collective self-feelings as a consequence of ethnic group evaluations. The results tended to support the self-esteem hypothesis. In-group favoritism was found to have a self-enhancing effect among participants high in ethnic identification. This result was found for ethnic majority (Dutch) and minority (Turkish) participants.

    Chronic low back pain: a prospective study with 4 to 15 years follow-up after a multidisciplinary biopsychosocial rehabilitation program

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    BACKGROUND: Multidisciplinary biopsychosocial rehabilitation (MBR) in patients with chronic low back pain (CLBP) is superior to less intensive treatments for at least one year, but the long-term course of the disease is largely unknown. The primary aim of this study was to describe the long-term course of an MBR in relation to pain, disability, and quality of life from the beginning of an MBR to between 4 to 15 years after participation. The secondary aim was to explore the long-term course of an MBR in relation to physiological outcomes of functioning. METHODS: This was a observational study conducted at a university hospital. The cohort consisted of participants of a 3-week, CLBP-specific MBR program between August 2001 and January 2013. The North American Spine Society questionnaire (NASS) pain and disability scale was the primary patient -reported outcome measure (PROM). The NASS neurogenic symptoms scale and the Short-Form 36 (SF-36) health survey were secondary PROMs. Patients were assessed before entry to the MBR (T0), at entry (T1), at discharge (T2) and 4 to 15 years after discharge (T3). Effects were quantified by effect size (ES). Score differences were tested for significance using parametric or non-parametric tests and linear mixed models. RESULTS: Of 299 consecutive patients from the MBR program, 229 could be contacted. Of these, 84 declined participation, five did not meet the inclusion criteria, and 26 had incomplete data. Thus, 114 patients were included. The mean follow-up time was 9.2 years. At T3, patients exhibited beneficial effects for NASS pain and disability with a moderate ES (ES = 0.63; p < 0.001). The NASS neurogenic symptoms scale was stable. The SF-36 scales showed an improvement in the bodily pain domain (ES = 1.02; p < 0.001), but no significant changes for physical functioning, physical role, general health, vitality, social functioning, emotional role, or mental health. The physical health component summary was improved (ES = 0.40, p = 0.002), and the mental health summary was unchanged. The linear mixed model analysis confirmed improvements in pain and disability between T1 and T3 (p = 0.010). CONCLUSIONS: The results of this study suggest that there is a long-term benefit of MBR participation in patients with CLBP

    Proving equivalence between imperative and MapReduce implementations using program transformations

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    Distributed programs are often formulated in popular functional frameworks like MapReduce, Spark and Thrill, but writing efficient algorithms for such frameworks is usually a non-trivial task. As the costs of running faulty algorithms at scale can be severe, it is highly desirable to verify their correctness. We propose to employ existing imperative reference implementations as specifications for MapReduce implementations. To this end, we present a novel verification approach in which equivalence between an imperative and a MapReduce implementation is established by a series of program transformations. In this paper, we present how the equivalence framework can be used to prove equivalence between an imperative implementation of the PageRank algorithm and its MapReduce variant. The eight individual transformation steps are individually presented and explained

    A comparison of multidisciplinary team residential rehabilitation with conventional outpatient care for the treatment of non-arthritic intra-articular hip pain in UK Military personnel:a protocol for a randomised controlled trial

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    BACKGROUND: Non-arthritic hip disorders are defined as abnormalities of the articulating surfaces of the acetabulum and femur before the onset of osteoarthritis, including intra-articular structures such as the acetabular labrum and chondral surfaces. Abnormal femoroacetabular morphology is commonly seen in young men who constitute much of the UK military population. Residential multidisciplinary team (MDT) rehabilitation for patients with musculoskeletal injuries has a long tradition in the UK military, however, there are no studies presenting empirical data on the efficacy of a residential MDT approach compared with individualised conventional outpatient treatment. With no available data, the sustainability of this care pathway has been questioned. The purpose of this randomised controlled trial is to compare the effects of a residential multidisciplinary intervention, to usual outpatient care, on the clinical outcomes of young active adults undergoing treatment for non-arthritic intra-articular hip pain. METHODS/DESIGN: The trial will be conducted at the Defence Medical Rehabilitation Centre, Headley Court, UK. One hundred military male participants with clinical indicators of non-arthritic intra-articular hip pain will be randomly allocated to either: (1) 7-day residential multidisciplinary team intervention, n = 50; (2) 6-week physiotherapist-led outpatient intervention (conventional care), n = 50. Measurements will be taken at baseline, post-treatment (1-week MDT group; 6-weeks physiotherapy group), and 12-weeks. The primary outcome measures are the function in daily living sub-scale of the Copenhagen Hip and Groin Outcome Score (HAGOS), the physical function subscale of the Non-arthritic Hip Score (NAHS), and VAS pain scale. Secondary outcomes include objective measures of physical capacity and general health. An intention-to-treat analysis will be performed using linear and mixed models. DISCUSSION: This study will be the first to assess the efficacy of intensive MDT rehabilitation, versus conventional outpatient care, for the management of non-arthritic hip pain. The results from this study will add to the evidence-base and inform clinical practice for the management of intra-articular non-arthritic hip pain and femoroacetabular impingement in young active adults. TRIAL REGISTRATION: ISRCTN Reference: ISRCTN 59255714 dated 11-Nov-2015 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12891-016-1309-z) contains supplementary material, which is available to authorized users

    Dynamic splinting home therapy for toe walking: a case report

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    Serial casting is frequently prescribed for toe-walking but that does not allow continued physical therapy (PT). This report described a child and family who chose dynamic splinting (DS) with concurrent PT for treatment. The patient presented with right hemiparesis; below average motor skills and a gait pattern of toe contact (without ankle foot orthosis). Four months of PT plus 6 hours/night of DS as home therapy, the patient's passive dorsiflexion increased 14° and she gained the ability to walk in "flat foot" contact without the Ankle Foot Orthosis. This concurrent treatment achieved improved gait pattern and strength training not possible with casting

    A verification-supported evolution approach to assist software application engineers in industrial factory automation

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    Automated production systems (aPS) are complex systems with high reliability standards which can – besides through traditional testing – be ensured by verification using formal methods. In this paper we present a development process for aPS software supported by efficient formal techniques with easy-to-use specification formalisms to increase applicability in the aPS engineering domain. Our approach is tailored to the development of evolving aPS as existing behavior of earlier revisions is reused as specification for the verification. The approach covers three verification phases: regression verification, verification of critical interlock invariants and delta specification and verification. The approach is designed to be comprehensible by aPS software engineers: Two practically applicable specification means are presented. Formal methods have not yet been widely adapted in industrial aPS development since they lack (a) scalability, and (b) concise and comprehensible specification means. This paper shows concepts how to tackle both issues by referring to existing behavior during evolution verification to advance towards the goal of applicability in the aPS engineering domain. A laboratory case study demonstrates the feasibility and performance of the approach and shows promising results
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