4,280 research outputs found

    Liver transplant recipients’ experiences and perspectives of a telehealth-delivered lifestyle programme A qualitative study

    Get PDF
    Introduction Dietary modification and exercise are encouraged to address cardiometabolic risk factors after solid organ transplantation. However, the lived experience of attempting positive lifestyle changes for liver transplant recipients is not known. The aim of this study was to explore the experiences of liver transplant recipients and their perspectives of a 12-week telehealth lifestyle programme and assess the feasibility of this innovative health service. Methods Focus groups and one-on-one interviews were conducted with participants who had completed a 12-week, group-based, telehealth-delivered diet and exercise programme and thematic qualitative analysis was used to code and theme the data. Results In total, 19 liver transplant recipients participated in the study (25-68 years, median time since transplant 4.4 years, 63% male). Overarching themes included: (a) 'broad telehealth advantages' which highlighted that telehealth reduced the perceived burdens of face-to-face care; (b) 'impact of employment' which identified employment as a competing priority and appeared to effect involvement with the programme; (c) 'adapting Mediterranean eating pattern to meet individual needs' which identified the adaptability of the Mediterranean diet supported by sessions with the dietitian; (d) 'increasing exercise confidence' which recognised that a tailored approach facilitated confidence and acceptability of the exercise component of the programme. Discussion A telehealth lifestyle programme delivered by dietitians and exercise physiologists is an acceptable alternative to face-to-face care that can meet the needs of liver transplant recipients. There is a need to further innovate and broaden the scope of routine service delivery beyond face-to-face consultations

    On the correlation function of the characteristic polynomials of the hermitian Wigner ensemble

    Full text link
    We consider the asymptotics of the correlation functions of the characteristic polynomials of the hermitian Wigner matrices Hn=n1/2WnH_n=n^{-1/2}W_n. We show that for the correlation function of any even order the asymptotic coincides with this for the GUE up to a factor, depending only on the forth moment of the common probability law QQ of entries Wjk\Im W_{jk}, Wjk\Re W_{jk}, i.e. that the higher moments of QQ do not contribute to the above limit.Comment: 20

    Negative moments of characteristic polynomials of random GOE matrices and singularity-dominated strong fluctuations

    Full text link
    We calculate the negative integer moments of the (regularized) characteristic polynomials of N x N random matrices taken from the Gaussian Orthogonal Ensemble (GOE) in the limit as NN \to \infty. The results agree nontrivially with a recent conjecture of Berry & Keating motivated by techniques developed in the theory of singularity-dominated strong fluctuations. This is the first example where nontrivial predictions obtained using these techniques have been proved.Comment: 13 page

    Entanglement in Quantum Spin Chains, Symmetry Classes of Random Matrices, and Conformal Field Theory

    Full text link
    We compute the entropy of entanglement between the first NN spins and the rest of the system in the ground states of a general class of quantum spin-chains. We show that under certain conditions the entropy can be expressed in terms of averages over ensembles of random matrices. These averages can be evaluated, allowing us to prove that at critical points the entropy grows like κlog2N+κ~\kappa\log_2 N + {\tilde \kappa} as NN\to\infty, where κ\kappa and κ~{\tilde \kappa} are determined explicitly. In an important class of systems, κ\kappa is equal to one-third of the central charge of an associated Virasoro algebra. Our expression for κ\kappa therefore provides an explicit formula for the central charge.Comment: 4 page

    Early Impact of the Affordable Care Act on Uptake of Long-acting Reversible Contraceptive Methods

    Get PDF
    The Affordable Care Act (ACA) required most private insurance plans to cover contraceptive services without patient cost-sharing as of January 2013 for most plans. Whether the ACA’s mandate has impacted long-acting reversible contraceptives (LARC) use is unknown

    Applications and generalizations of Fisher-Hartwig asymptotics

    Full text link
    Fisher-Hartwig asymptotics refers to the large nn form of a class of Toeplitz determinants with singular generating functions. This class of Toeplitz determinants occurs in the study of the spin-spin correlations for the two-dimensional Ising model, and the ground state density matrix of the impenetrable Bose gas, amongst other problems in mathematical physics. We give a new application of the original Fisher-Hartwig formula to the asymptotic decay of the Ising correlations above TcT_c, while the study of the Bose gas density matrix leads us to generalize the Fisher-Hartwig formula to the asymptotic form of random matrix averages over the classical groups and the Gaussian and Laguerre unitary matrix ensembles. Another viewpoint of our generalizations is that they extend to Hankel determinants the Fisher-Hartwig asymptotic form known for Toeplitz determinants.Comment: 25 page

    Spectral statistics for unitary transfer matrices of binary graphs

    Full text link
    Quantum graphs have recently been introduced as model systems to study the spectral statistics of linear wave problems with chaotic classical limits. It is proposed here to generalise this approach by considering arbitrary, directed graphs with unitary transfer matrices. An exponentially increasing contribution to the form factor is identified when performing a diagonal summation over periodic orbit degeneracy classes. A special class of graphs, so-called binary graphs, is studied in more detail. For these, the conditions for periodic orbit pairs to be correlated (including correlations due to the unitarity of the transfer matrix) can be given explicitly. Using combinatorial techniques it is possible to perform the summation over correlated periodic orbit pair contributions to the form factor for some low--dimensional cases. Gradual convergence towards random matrix results is observed when increasing the number of vertices of the binary graphs.Comment: 18 pages, 8 figure

    Random matrix theory, the exceptional Lie groups, and L-functions

    Full text link
    There has recently been interest in relating properties of matrices drawn at random from the classical compact groups to statistical characteristics of number-theoretical L-functions. One example is the relationship conjectured to hold between the value distributions of the characteristic polynomials of such matrices and value distributions within families of L-functions. These connections are here extended to non-classical groups. We focus on an explicit example: the exceptional Lie group G_2. The value distributions for characteristic polynomials associated with the 7- and 14-dimensional representations of G_2, defined with respect to the uniform invariant (Haar) measure, are calculated using two of the Macdonald constant term identities. A one parameter family of L-functions over a finite field is described whose value distribution in the limit as the size of the finite field grows is related to that of the characteristic polynomials associated with the 7-dimensional representation of G_2. The random matrix calculations extend to all exceptional Lie groupsComment: 14 page
    corecore