1,183 research outputs found

    Limit of vanishing regulator in the functional renormalization group

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    The nonperturbative functional renormalization group equation depends on the choice of a regulator function, whose main properties are a "coarse-graining scale"k and an overall dimensionless amplitude a. In this paper we shall discuss the limit a→0 with k fixed. This limit is closely related to the pseudoregulator that reproduces the beta functions of the MS¯ scheme that we studied in a previous paper. It is not suitable for precision calculations but it appears to be useful to eliminate the spurious breaking of symmetries by the regulator, both for nonlinear models and within the background field method

    Functional renormalization and the MS scheme

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    Working with scalar field theories, we discuss choices of regulator that, inserted in the functional renormalization group equation, reproduce the results of dimensional regularization at one and two loops. The resulting flow equations can be seen as nonperturbative extensions of the MS scheme. We support this claim by recovering all the multicritical models in two dimensions. We discuss a possible generalization to any dimension. Finally, we show that the method also preserves nonlinearly realized symmetries, which is a definite advantage with respect to other regulators

    Acute impact of a national lockdown during the COVID-19 pandemic on wellbeing outcomes among individuals with chronic pain

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    Changes to wellbeing in a community- based sample of 638 adults with non-malignant chronic pain were assessed during a period of mandated lockdown measures in the UK to control the COVID-19 outbreak. Participants completed an online survey pre-lockdown and were followed up during lockdown. Multivariate analysis demonstrate that decreased ability to self-manage, restricted access to healthcare and increased dependence on others were associated with negative wellbeing outcomes related to sleep, anxiety and depression. Essential but nonurgent services are required during periods of lockdown to maintain independence and self-management in order to preserve wellbeing in this population

    The 2021 NICE guidelines for assessment and management of chronic pain: A cross-sectional study mapping against a sample of 1,000* in the community

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    Objectives To characterise the prevailing pharmacological and non-pharmacological pain management strategies among adults with chronic pain, comparing these against the newly published NICE guidelines NG-193, and examine these pre-NG-193 pain management strategies in relation to pain severity, pain interference, sleep quality and mental health outcomes. Design This study was conducted using a cross-sectional online survey study design. Setting This study was conducted on a community-dwelling cohort. Participants Adults aged 18+, living in the UK, with diagnosis of chronic pain by a health care professional. Main outcome measures Primary outcomes were characterisation of the pain management strategies utilised. Secondary outcomes were related to pain severity, pain interference, sleep quality, depression and anxiety via validated self-report measures. Results Several strategies were employed by respondents to manage their chronic pain condition including physical therapy, exercise, psychological therapy and pharmacological therapy. The data also indicated a high level of joint-care planning among patients and their clinicians. Some group differences were found in relation to pain, sleep and mental health outcomes. Conclusion This study set a comparative starting baseline to which the efficacy of the NG-193 may be compared in future years. There is evidence that NICE recommendations are being followed for the management of chronic primary pain conditions; however, pharmacological use of opioid drugs is still reported by 47%. Despite the confirmed evidence in this study of small efficacy of chronic pain by pharmacological agent, the reduction in the use of pain relief medications be it over the counter medications or prescription opioids, as recommended by NG-193, may be slow to be adopted. The data suggest that more care provision is needed to meet the recommendations around pharmacological management and review

    Approximation of corner polyhedra with families of intersection cuts

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    We study the problem of approximating the corner polyhedron using intersection cuts derived from families of lattice-free sets in Rn\mathbb{R}^n. In particular, we look at the problem of characterizing families that approximate the corner polyhedron up to a constant factor, which depends only on nn and not the data or dimension of the corner polyhedron. The literature already contains several results in this direction. In this paper, we use the maximum number of facets of lattice-free sets in a family as a measure of its complexity and precisely characterize the level of complexity of a family required for constant factor approximations. As one of the main results, we show that, for each natural number nn, a corner polyhedron with nn basic integer variables and an arbitrary number of continuous non-basic variables is approximated up to a constant factor by intersection cuts from lattice-free sets with at most ii facets if i>2n−1i> 2^{n-1} and that no such approximation is possible if i≀2n−1i \leq 2^{n-1}. When the approximation factor is allowed to depend on the denominator of the fractional vertex of the linear relaxation of the corner polyhedron, we show that the threshold is i>ni > n versus i≀ni \leq n. The tools introduced for proving such results are of independent interest for studying intersection cuts

    Kinetic theory and dynamic structure factor of a condensate in the random phase approximation

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    We present the microscopic kinetic theory of a homogeneous dilute Bose condensed gas in the generalized random phase approximation (GRPA), which satisfies the following requirements: 1) the mass, momentum and energy conservation laws; 2) the H-theorem; 3) the superfluidity property and 4) the recovery of the Bogoliubov theory at zero temperature \cite{condenson}. In this approach, the condensate influences the binary collisional process between the two normal atoms, in the sense that their interaction force results from the mediation of a Bogoliubov collective excitation traveling throughout the condensate. Furthermore, as long as the Bose gas is stable, no collision happens between condensed and normal atoms. In this paper, we show how the kinetic theory in the GRPA allows to calculate the dynamic structure factor at finite temperature and when the normal and superfluid are in a relative motion. The obtained spectrum for this factor provides a prediction which, compared to the experimental results, allows to validate the GRPA. PACS numbers:03.75.Hh, 03.75.Kk, 05.30.-dComment: 6 pages, 1 figures, QFS2004 conferenc

    Exploring the feasibility and acceptability of a sleep wearable headband among a community sample of chronic pain individuals: An at-home observational study

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    Background Chronic pain conditions affect up to one third of the adult population in the United Kingdom. Sleep problems are prevalent and negatively impact quality of life. Lack of standardised tools for routine screening and assessment of sleep changes have been a barrier for sleep management. Novel sleep wearables offer an exciting and accessible way to measure sleep but have not been tested outside of the consumer-led landscape and are not commonly used in research and clinical settings. Aims The study aimed to explore the feasibility and acceptability of a sleep monitoring headband (Dreem 2) utilising EEG technology and accompanying smartphone application among a cohort of adults with chronic pain. Results Twenty-one adults (81% women) completed a one-week home sleep study using a sleep headband and accompanying app. Ninety per cent of participants met the pre-defined requirement of two-night's sleep recording. All participants recorded one night of sleep data via the sleep headband. The majority (76%) of participants were satisfied with the sleep study, and 86% of participants were willing to wear the headband longer than the 2-night minimum requirement. Finally, 76% reported the headband as ‘somewhat’ or ‘extremely’ comfortable whist awake; 57% rated the headband as comfortable during sleep. Conclusion The Dreem 2 headband appears to be a feasible and acceptable means of collecting sleep measurements among individuals with chronic pain, despite common sleep disturbances. These devices may have utility for screening, assessment and monitoring in research and practice. Further research is needed to provide guidelines and training for integration

    Coating development with modified starch and tomato powder for application in frozen dough.

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    Made available in DSpace on 2018-06-07T01:06:15Z (GMT). No. of bitstreams: 1 ART18023.pdf: 3157377 bytes, checksum: 1efc7c50df294f9ed6903135a6cd2f48 (MD5) Previous issue date: 2018-06-04bitstream/item/178253/1/ART18023.pd

    Hereditary Cancer Syndromes: A Comprehensive Review with a Visual Tool

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    Hereditary cancer syndromes account for nearly 10% of cancers even though they are often underdiagnosed. Finding a pathogenic gene variant could have dramatic implications in terms of pharmacologic treatments, tailored preventive programs, and familiar cascade testing. However, diagnosing a hereditary cancer syndrome could be challenging because of a lack of validated testing criteria or because of their suboptimal performance. In addition, many clinicians are not sufficiently well trained to identify and select patients that could benefit from a genetic test. Herein, we searched the available literature to comprehensively review and categorize hereditary cancer syndromes affecting adults with the aim of helping clinicians in their daily clinical practice through a visual tool

    Experimental observation of the Bogoliubov transformation for a Bose-Einstein condensed gas

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    Phonons with wavevector q/ℏq/\hbar were optically imprinted into a Bose-Einstein condensate. Their momentum distribution was analyzed using Bragg spectroscopy with a high momentum transfer. The wavefunction of the phonons was shown to be a superposition of +q and -q free particle momentum states, in agreement with the Bogoliubov quasiparticle picture.Comment: 4 pages, 3 figures, please take postscript version for the best version of Fig
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