General practitioners’ perceptions of asynchronous telemedicine in a randomized controlled trial of teledermatology.

Background: Telemedicine is viewed as having a key role to play in the Government’s plans to modernise the NHS.1 However, to date there are few studies which have explored the views and acceptability of GPs towards telemedicine in primary care. Aim: To elicit the perceptions of GPs towards teledermatology (TD) before and after it’s introduction into their Practices and to observe whether GP views of TD had changed over the course of the study. Design of study: A postal questionnaire administered as part of a wider randomised controlled trial of telemedicine in dermatology. Setting: A locality group of eight General Practices in Sheffield and a single teaching hospital in Sheffield that provided the local dermatology referral service. Method: A postal questionnaire circulated to all GPs from the eight participating Practices. Results: A 85.7% (36/42) response rate was achieved. Only 21% (n=7; 95% CI: 10-37%) of respondents felt satisfied/very satisfied with TD in their Practice, 47% (n=16) said that they were dissatisfied or very dissatisfied. Thirty one per cent (n=10; 95% CI: 18-49%) said that they felt confident about diagnosis and management of care through TD, with 28% (n=9) reporting that they were unconfident. Only 23% (n=8; 95% CI: 12-39%) of respondents said that they would consider using a telemedicine system in the future, 34% (n=12) said they would probably or definitely not and 43% (n=15) were unsure. There was some evidence that GPs views about TD became more negative over the course of the study. Conclusions: The study reports less favourable GP responses to telemedicine than observed in previous studies, and suggests that the model of telemedicine described in this study paper would not be widely acceptable to GPs

Renormalization-group anatomy of transverse-momentum dependent parton distribution functions in QCD

The ultraviolet and rapidity divergences of transverse-momentum dependent parton distribution functions with lightlike and transverse gauge links is studied, also incorporating a soft eikonal factor. We find that in the light-cone gauge with $q^-$-independent pole prescriptions extra divergences appear which amount, at one-loop, to a cusp-like anomalous dimension. We show that such contributions are absent when the Mandelstam-Leibbrandt prescription is used. In the first case, the soft factor cancels the anomalous-dimension defect, while in the second case its ultraviolet-divergent part reduces to unity.Comment: 10 pages, 3 figures; needs ws-mpla-hep.cls (supplied). Talk presented by the first author at Workshop on "Recent Advances in Perturbative QCD and Hadronic Physics", 20--25 July 2009, ECT*, Trento, Italy, in Honor of Prof. Anatoly Efremov's 75th birthda

Factorization of low-energy gluons in exclusive processes

We outline a proof of factorization in exclusive processes, taking into account the presence of soft and collinear modes of arbitrarily low energy, which arise when the external lines of the process are taken on shell. Specifically, we examine the process of e^+e^- annihilation through a virtual photon into two light mesons. In an intermediate step, we establish a factorized form that contains a soft function that is free of collinear divergences. In contrast, in soft-collinear effective theory, the low-energy collinear modes factor most straightforwardly into the soft function. We point out that the cancellation of the soft function, which relies on the color-singlet nature of the external hadrons, fails when the soft function contains low-energy collinear modes.Comment: 18 pages, 10 figures, 2 tables, version published in Physical Review

Factorization theorems for exclusive heavy-quarkonium production

We outline the proofs of the factorization theorems for exclusive two-body charmonium production in B-meson decay and e^+e^- annihilation to all orders in perturbation theory in quantum chromodynamics. We find that factorized expressions hold up to corrections of order m_c/m_b in B-meson decay and corrections of order m_c^2/s in e^+e^- annihilation, where m_c is the charm-quark mass, m_b is the bottom-quark mass, and root-s is the e^+e^- center-of-momentum energy.Comment: 4 pages, 2 figure

Fully Unintegrated Parton Correlation Functions and Factorization in Lowest Order Hard Scattering

Motivated by the need to correct the potentially large kinematic errors in approximations used in the standard formulation of perturbative QCD, we reformulate deeply inelastic lepton-proton scattering in terms of gauge invariant, universal parton correlation functions which depend on all components of parton four-momentum. Currently, different hard QCD processes are described by very different perturbative formalisms, each relying on its own set of kinematical approximations. In this paper we show how to set up formalism that avoids approximations on final-state momenta, and thus has a very general domain of applicability. The use of exact kinematics introduces a number of significant conceptual shifts already at leading order, and tightly constrains the formalism. We show how to define parton correlation functions that generalize the concepts of parton density, fragmentation function, and soft factor. After setting up a general subtraction formalism, we obtain a factorization theorem. To avoid complications with Ward identities the full derivation is restricted to abelian gauge theories; even so the resulting structure is highly suggestive of a similar treatment for non-abelian gauge theories.Comment: 44 pages, 69 figures typos fixed, clarifications and second appendix adde

Corporate governance, Islamic governance and earnings management in Oman: A new empirical insights from a behavioural theoretical framework

Purpose: This paper examines the impact of corporate (CG) and Islamic (IG) governance mechanisms on corporate earnings management (EM) behaviour in Oman. Design/Methodology/Approach: We employ one of the largest and extensive datasets to-date on CG, IG and EM in any developing country, consisting of a sample of 116 unique Omani listed corporations from 2001 to 2011 (i.e.,1,152 firm-year observations) and a broad CG index containing 72 CG provisions. We also employ a number of robust econometric models that sufficiently account for alternative CG/EM proxies and potential endogeneities. Findings: First, we find that, on average, better-governed corporations tend to engage significantly less in EM than their poorly-governed counterparts. Second, our evidence suggests that corporations that depict greater commitment towards incorporating Islamic religious beliefs and values into their operations through the establishment of an IG committee tend to engage significantly less in EM than their counterparts without such a committee. Finally and by contrast, we do not find any evidence that board size, audit firm size, the presence of a CG committee and board gender diversity have any significant relationship with the extent of EM. Originality: To the best of our knowledge, this is a first empirical attempt at examining the extent to which CG and IG structures may drive EM practices that explicitly seeks to draw new insights from a behavioural theoretical framework (i.e., behavioural theory of corporate boards and governance). Keywords: Corporate governance, Islamic governance, earnings management, behavioural theory, endogeneity, Oman. Paper type: Research pape

Quantization effects in Viterbi decoding rate 1/n convolutional codes

A Viterbi decoder's performance loss due to quantizing data from the additive white Gaussian noise (AWGN) channel is studied. An optimal quantization scheme and branch metric calculation method are presented. The uniformly quantized channel capacity C(sub u)(q) is used to determine the smallest number of quantization bits q that does not cause a significant loss. The quantizer stepsize which maximizes C(sub u)(q) almost minimizes the decoder bit error rate (BER). However, a slightly larger stepsize is better, like the value that minimizes the Bhattacharyya bound. The range and renormalization of state metrics is analyzed, in particular for K = 15 decoders such as the Big Viterbi Decoder (BVD) for the Galileo mission. These results are required to design reduced hardware complexity Viterbi decoders with a negligible quantization loss

Cosmology with velocity dispersion counts: an alternative to measuring cluster halo masses

The evolution of galaxy cluster counts is a powerful probe of several fundamental cosmological parameters. A number of recent studies using this probe have claimed tension with the cosmology preferred by the analysis of the Planck primary CMB data, in the sense that there are fewer clusters observed than predicted based on the primary CMB cosmology. One possible resolution to this problem is systematic errors in the absolute halo mass calibration in cluster studies, which is required to convert the standard theoretical prediction (the halo mass function) into counts as a function of the observable (e.g., X-ray luminosity, Sunyaev-Zel'dovich flux, optical richness). Here we propose an alternative strategy, which is to directly compare predicted and observed cluster counts as a function of the one-dimensional velocity dispersion of the cluster galaxies. We argue that the velocity dispersion of groups/clusters can be theoretically predicted as robustly as mass but, unlike mass, it can also be directly observed, thus circumventing the main systematic bias in traditional cluster counts studies. With the aid of the BAHAMAS suite of cosmological hydrodynamical simulations, we demonstrate the potential of the velocity dispersion counts for discriminating even similar $\Lambda$CDM models. These predictions can be compared with the results from existing redshift surveys such as the highly-complete Galaxy And Mass Assembly (GAMA) survey, and upcoming wide-field spectroscopic surveys such as the Wide Area Vista Extragalactic Survey (WAVES) and the Dark Energy Survey Instrument (DESI).Comment: 15 pages, 13 figures. Accepted for publication in MNRAS. New section on cosmological forecasts adde

Random quantum channels I: graphical calculus and the Bell state phenomenon

This paper is the first of a series where we study quantum channels from the random matrix point of view. We develop a graphical tool that allows us to compute the expected moments of the output of a random quantum channel. As an application, we study variations of random matrix models introduced by Hayden \cite{hayden}, and show that their eigenvalues converge almost surely. In particular we obtain for some models sharp improvements on the value of the largest eigenvalue, and this is shown in a further work to have new applications to minimal output entropy inequalities.Comment: Several typos were correcte

Next-to-Leading Order Hard Scattering Using Fully Unintegrated Parton Distribution Functions

We calculate the next-to-leading order fully unintegrated hard scattering coefficient for unpolarized gluon-induced deep inelastic scattering using the logical framework of parton correlation functions developed in previous work. In our approach, exact four-momentum conservation is maintained throughout the calculation. Hence, all non-perturbative functions, like parton distribution functions, depend on all components of parton four-momentum. In contrast to the usual collinear factorization approach where the hard scattering coefficient involves generalized functions (such as Dirac $\delta$-functions), the fully unintegrated hard scattering coefficient is an ordinary function. Gluon-induced deep inelastic scattering provides a simple illustration of the application of the fully unintegrated factorization formalism with a non-trivial hard scattering coefficient, applied to a phenomenologically interesting case. Furthermore, the gluon-induced process allows for a parameterization of the fully unintegrated gluon distribution function.Comment: 22 pages, Typos Fixed, Reference Added, Minor Clarification Adde