From urn models to zero-range processes: statics and dynamics

The aim of these lecture notes is a description of the statics and dynamics of zero-range processes and related models. After revisiting some conceptual aspects of the subject, emphasis is then put on the study of the class of zero-range processes for which a condensation transition arises.Comment: Lecture notes for the Luxembourg Summer School 200

Household transmission of invasive group A Streptococcus infections in England: a population-based study, 2009, 2011 to 13

Invasive group A s treptococcal infection has a 15% case fatality rate and a risk of secondary transmission. This retrospective study us ed two national data sources from England ; enhanced surveillance ( 2009) and a case management system ( 2011 - 13) to identify clusters of sever e group A streptococcal disease . 2 4 household pairs were identified. The median onset interval between cases was 2 days (range 0 - 28) with simultaneous onset in 8 pairs . The attack rate during the 30 days after first exposure to a primary case was 4 52 0 per 100000 person - years at risk (95% CI 2 900 - 673 0 ) a 19 40 ( 12 40 - 28 80 ) fold elevation over the background incidence . The theoretical number needed to treat ( NNT ) to prevent one secondary case using antibiotic prophylaxis was 2 71 ( 194 - 454 ) overall, 50 for mother - neonate pairs ( 2 7 - 3 93 ) and 8 2 for couples aged 75 years and over ( 46 - 417 ). Whilst a dramatic increased risk of infection was noted in all household contacts, increased ris k was greatest for mother - neonate pairs and couples aged 75 and over , suggesting targeted prophylaxis c ould be considered. Offering prophylaxis is challenging due to the short time interval between cases emphasising the importance of immediate notification and assessment of contacts

Domain Growth in a 1-D Driven Diffusive System

The low-temperature coarsening dynamics of a one-dimensional Ising model, with conserved magnetisation and subject to a small external driving force, is studied analytically in the limit where the volume fraction \mu of the minority phase is small, and numerically for general \mu. The mean domain size L(t) grows as t^{1/2} in all cases, and the domain-size distribution for domains of one sign is very well described by the form P_l(l) \propto (l/L^3)\exp[-\lambda(\mu)(l^2/L^2)], which is exact for small \mu (and possibly for all \mu). The persistence exponent for the minority phase has the value 3/2 for \mu \to 0.Comment: 8 pages, REVTeX, 7 Postscript figures, uses multicol.sty and epsf.sty. Submitted to Phys. Rev.

Anomalous self-diffusion in the ferromagnetic Ising chain with Kawasaki dynamics

We investigate the motion of a tagged spin in a ferromagnetic Ising chain evolving under Kawasaki dynamics. At equilibrium, the displacement is Gaussian, with a variance growing as $A t^{1/2}$. The temperature dependence of the prefactor $A$ is derived exactly. At low temperature, where the static correlation length $\xi$ is large, the mean square displacement grows as $(t/\xi^2)^{2/3}$ in the coarsening regime, i.e., as a finite fraction of the mean square domain length. The case of totally asymmetric dynamics, where $(+)$ (resp. $(-)$) spins move only to the right (resp. to the left), is also considered. In the steady state, the displacement variance grows as $B t^{2/3}$. The temperature dependence of the prefactor $B$ is derived exactly, using the Kardar-Parisi-Zhang theory. At low temperature, the displacement variance grows as $t/\xi^2$ in the coarsening regime, again proportionally to the mean square domain length.Comment: 22 pages, 8 figures. A few minor changes and update

The future of public sector accounting research. A polyphonic debate

PurposeThe purpose of this polyphonic paper is to report on interdisciplinary discussions on the state-of-the-art and future of public sector accounting research (PSAR). The authors hope to enliven the debates of the past and future developments in terms of context, themes, theories, methods and impacts in the field of PSAR by the exchanges they include here. Design/methodology/approachThis polyphonic paper adopts an interdisciplinary approach. It brings into conversation ideas, views and approaches of several scholars on the actual and future developments of PSAR in various contexts, and explores potential implications. FindingsThis paper has brought together scholars from a plurality of disciplines, research methods and geographical areas, showing at the same time several points of convergence on important future themes (such as accounting as a mean for public, accounting, hybridity and value pluralism) and enabling conditions (accounting capabilities, profession and digitalisation) for PSA scholarship and practice, and the richness of looking at them from a plurality of perspectives. Research limitations/implicationsExploring these past and future developments opens up the potential for interesting theoretical insights. A much greater theoretical and practical reconsideration of PSAR will be fostered by the exchanges included here. Originality/valueIn setting out a future research agenda, this paper fosters theoretical and methodological pluralism in the interdisciplinary research community interested in PSAR in various contexts. The discussion perspectives presented in this paper constitute not only a basis for further research in this relevant accounting area on the role, status and developments of PSAR but also creative potential for practitioners to be more reflective on their practices and also intended and united outcomes of such practices

New Dynamic Monte Carlo Renormalization Group Method

The dynamical critical exponent of the two-dimensional spin-flip Ising model is evaluated by a Monte Carlo renormalization group method involving a transformation in time. The results agree very well with a finite-size scaling analysis performed on the same data. The value of $z = 2.13 \pm 0.01$ is obtained, which is consistent with most recent estimates

Clinical use of HIV integrase inhibitors : a systematic review and meta-analysis

Background: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings. Methods: MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted. Results: 48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir. Conclusion: In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment

From Providers to PHOs: an institutional analysis of nonprofit primary health care governance in New Zealand

Policy reforms to primary health care delivery in New Zealand required government-funded firms overseeing care delivery to be constituted as nonprofit entities with governance shared between consumer and producers. This paper examines the consumer and producer interests in the allocation of ownership and control of New Zealand firms delivering primary health care utilising theories of competition in the markets for ownership and control of firms. Consistent with pre-reform patterns of ownership and control provider interests appear to have exerted effective control over the formation and governance of the new entities in all but a few cases where community (consumer) control was already established. Their ability to do so is implied from the absence of a defined ownership stake via which the balance of governance control could shift as a consequence of changes to incentives facing the different stakeholding groups. It appears that the pre-existing patterns will prevail and further intervention will be required if policymakers are to achieve their underlying aims

Financial reporting by smaller charities: drivers of the cash/accruals choice

All UK charities are required by law to publish annual accounts. This study is concerned with the choice faced by smaller charities whether to use the accruals (charities SORP) or receipts and payments (R&P) basis. A study of financial reporting by 90 smaller Scottish charities, supplemented by interviews, examined drivers behind the choice of approach. Both accruals and R&P accounts were considered legitimate means of reporting and the choice was found to be driven largely by perceived preferences of users of accounts rather than costs