1,595 research outputs found

    Impurity effect of Lambda hyperon on collective excitations of atomic nuclei

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    Taking the ground state rotational band in 24^{24}Mg as an example, we investigate the impurity effect of Λ\Lambda hyperon on collective excitations of atomic nuclei in the framework of non-relativistic energy density functional theory. To this end, we take into account correlations related to the restoration of broken symmetries and fluctuations of collective variables by solving the eigenvalue problem of a five-dimensional collective Hamiltonian for quadrupole vibrational and rotational degrees of freedom. The parameters of the collective Hamiltonian are determined with constrained mean-field calculations for triaxial shapes using the SGII Skyrme force. We compare the low-spin spectrum for 24^{24}Mg with the spectrum for the same nucleus inside Λ25^{25}_{\Lambda}Mg. It is found that the Λ\Lambda hyperon stretches the ground state band and reduces the B(E2:21+01+)B(E2:2^+_1 \rightarrow 0^+_1) value by 9\sim 9%, mainly by softening the potential energy surface towards the spherical shape, even though the shrinkage effect on the average proton radius is only 0.5\sim0.5%.Comment: 16 pages, 5 figures, and 1 tabl

    Deformation of Lambda hypernuclei

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    We study the deformation property of Λ\Lambda hypernuclei using the relativistic mean field (RMF) method. We find that Λ29^{29}_{\Lambda}Si and Λ13^{13}_{\Lambda}C hypernuclei have spherical shape as a consequence of the additional Λ\Lambda particle, whereas the corresponding core nuclei, 28^{28}Si and 12^{12}C, are oblately deformed. Most of other hypernuclei have a similar deformation parameter to the core nucleus, in accordance with the previous study with the non-relativistic Skyrme-Hartree-Fock method. We discuss the sensitivity of our results to the choice of pairing interaction and to the parameter set of the RMF Lagrangian.Comment: 5 pages, 6 eps figure

    Optimum Quantum Error Recovery using Semidefinite Programming

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    Quantum error correction (QEC) is an essential element of physical quantum information processing systems. Most QEC efforts focus on extending classical error correction schemes to the quantum regime. The input to a noisy system is embedded in a coded subspace, and error recovery is performed via an operation designed to perfectly correct for a set of errors, presumably a large subset of the physical noise process. In this paper, we examine the choice of recovery operation. Rather than seeking perfect correction on a subset of errors, we seek a recovery operation to maximize the entanglement fidelity for a given input state and noise model. In this way, the recovery operation is optimum for the given encoding and noise process. This optimization is shown to be calculable via a semidefinite program (SDP), a well-established form of convex optimization with efficient algorithms for its solution. The error recovery operation may also be interpreted as a combining operation following a quantum spreading channel, thus providing a quantum analogy to the classical diversity combining operation.Comment: 7 pages, 3 figure

    Feasibility study of Glucagon-like peptide-1 analogues for the optimization of Outcomes in obese patients undergoing AbLation for Atrial Fibrillation (GOAL-AF) protocol

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    BackgroundCatheter ablation for atrial fibrillation is recommended for symptomatic patients after failed medical therapy. Ablation has a higher failure rate in obese patients, and both the prevalence of atrial fibrillation and obesity are increasingly globally. The outcome of ablation can be improved if obese patients can achieve goal-oriented weight reduction prior to ablation. Conventional weight loss strategies, however, can be difficult to access and can delay ablation, thereby risking a lower chance of maintaining sinus rhythm. Effective weight-loss medications, such as the glucagon-like peptide inhibitor-1 drugs, offer the potential for incremental impact on weight loss over a shorter period of time as a bridging therapy. The aim of this study is to assess the feasibility of using liraglutide, a glucagon-like peptide inhibitor-1, in producing weight loss in obese patients before catheter ablation.MethodsThe study is an open-label, uncontrolled, prospective single-centre feasibility study of daily liraglutide injections in the treatment of obese patients for at least 13 weeks before and 52 weeks after AF ablation. Adult patients with symptomatic AF whose body mass index ≥ 30 will be recruited from those planning to undergo ablation. Feasibility will be determined based on the recruitment rate, adherence to the medication, and the amount of weight loss achieved over the study period. Exploratory outcomes include changes in atrial structure, function, and fibrosis with weight loss evaluated by cardiac magnetic resonance imaging, electroanatomic mapping, and patient-reported outcome measure.DiscussionThis study will allow us to determine whether the use of liraglutide in obese patients with atrial fibrillation undergoing ablation is feasible with adequate recruitment. The additional information on adherence and average weight loss over the study period will inform the design of a future definitive randomized controlled trial.Trial registrationClinicalTrials.gov (NCT05221229). Registered on 2 February 2022.Trial fundingMetchley Park Medical Society and University of Birmingham Starter Fellowship, British Heart Foundation Accelerator Grant, Abbott Investigator-Initiated Study Grant

    Investigation of the Characteristics of the Three-axis Ring Typed Angular Velocity Transducer Based on Optical Tunneling Effect

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    The structure of a three-axis ring type angular velocity transducer based on the optical tunnel effect (OTE) is proposed. In this article considered the primary motion, which is excited by the electrostatic means and on the secondary displacements which provide the applied angular velocity information. Keywords: three-axis transducer, angular velocity, optical tunneling effect, ring resonator

    Association between antimicrobial stewardship programs and antibiotic use globally: a systematic review and meta-analysis

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    IMPORTANCE: Antimicrobial resistance continues to spread rapidly at a global scale. Little evidence exists on the association of antimicrobial stewardship programs (ASPs) with the consumption of antibiotics across health care and income settings. OBJECTIVE: To synthesize current evidence regarding the association between antimicrobial stewardship programs and the consumption of antibiotics globally. DATA SOURCES: PubMed, Web of Science, and Scopus databases were searched from August 1, 2010, to Aug 1, 2020. Additional studies from the bibliography sections of previous systematic reviews were included. STUDY SELECTION: Original studies of the association of ASPs with antimicrobial consumption across health care and income settings. Animal and environmental studies were excluded. DATA EXTRACTION AND SYNTHESIS: Following the Preferred Reporting Items in Systematic Reviews and Meta-Analyses guideline, the pooled association of targeted ASPs with antimicrobial consumption was measured using multilevel random-effects models. The Effective Public Health Practice Project quality assessment tool was used to assess study quality. MAIN OUTCOMES AND MEASURES: The main outcome measures were proportion of patients receiving an antibiotic prescription and defined daily doses per 100 patient-days. RESULTS: Overall, 52 studies (with 1 794 889 participants) measured the association between ASPs and antimicrobial consumption and were included, with 40 studies conducted in high-income countries and 12 in low- and middle-income countries (LMICs). ASPs were associated with a 10% (95% CI, 4%-15%) reduction in antibiotic prescriptions and a 28% reduction in antibiotic consumption (rate ratio, 0.72; 95% CI, 0.56-0.92). ASPs were also associated with a 21% (95% CI, 5%-36%) reduction in antibiotic consumption in pediatric hospitals and a 28% reduction in World Health Organization watch groups antibiotics (rate ratio, 0.72; 95% CI, 0.56-0.92). CONCLUSIONS AND RELEVANCE: In this systematic review and meta-analysis, ASPs appeared to be effective in reducing antibiotic consumption in both hospital and nonhospital settings. Impact assessment of ASPs in resource-limited settings remains scarce; further research is needed on how to best achieve reductions in antibiotic use in LMICs

    Agency in Transport Service: Implications of Traveller Mode Choice Objective and Latent Attributes Using Random Parameter Logit Model

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    Abstract: This paper explains how principal-agent theory (PAT) can be used as an analytical tool to understand the traveller-Transport for NSW (TfNSW) relationship and minimise the agency problem in the relationship by examining traveller preferences for mode choices. The paper emphasises latent variables (LVs) and traditional objective attributes (TOAs) together during the choice process within the agency relationship, as a method by which the utility of the principal (traveller) can be maximised and evaluated using a discrete choice experiment, i.e. random parameter logit (RPL) model. The probability of car use is significantly higher than public transport, which indicates that an agency problem exists in the relationship and incorporating traveller preferences in the transport projects may minimise this problem. Citation: Anwar, A.H.M., Tieu, K., Gibson, P., Win, K.T. & Berryman, M.J. (2014). Agency in Transport Service: Implications of Traveller Mode Choice Objective and Latent Attributes Using Ransom Parameter Logit Model. In: Campbell P. and Perez P. (Eds), Proceedings of the International Symposium of Next Generation Infrastructure, 1-4 October 2013, SMART Infrastructure Facility, University of Wollongong, Australia
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