Online Data Collection to Evaluate a Theoretical Cognitive Model of Tinnitus

Purpose The purpose of this article is to describe data collection considerations, methods, and response rates for a survey available both online and on paper. Methodological issues in the design of online data collection, and advantages and disadvantages of different data collection methods are discussed. Method A survey was compiled that included 9 full or partial clinical questionnaires designed to measure different components relevant to tinnitus distress. It was completed once by 342 members of the public with tinnitus. Respondents could choose whether to complete the survey online or on paper. Results Ninety-five percent of participants chose to complete the survey online. The advantages of an online self-administered questionnaire include low numbers of unanswered questions, convenience (particularly in a longer survey such as this), a fast return rate, and reduced expense. Age emerged as an important variable, with those opting to complete the paper-based version of the survey being older. Conclusions Online data collection has several advantages to both participants and researchers. However, cross-sectional studies such as that presented here should also offer paper questionnaires to avoid excluding certain subgroups of the population. Ethics and reporting guidelines for Internet-delivered questionnaire studies are available. These can usefully inform study design and guide high-quality reporting.Lucy Handscomb was funded by the British Tinnitus Asso-ciation. Deborah A. Hall and Derek J. Hoare were funded bythe Nat ional Institute for Health Research (NIHR) BiomedicalResearch Unit program

Numerical Study of the Spin-Flop Transition in Anisotropic Spin-1/2 Antiferromagnets

Magnetization processes of the spin-1/2 antiferromagnetic $XXZ$ model in two and three spatial dimensions are studied using quantum Monte Carlo method based on stochastic series expansions. Recently developed operator-loop algorithm enables us to show a clear evidence of the first-order phase transition in the presence of an external magnetic field. Phase diagrams of closely related systems, hard core bosons with nearest-neighbor repulsions, are also discussed focusing on possibilities of phase-separated and supersolid phases.Comment: 4 pages, Revtex version 4, with 4 figures embedded, To appear in Phys. Rev.

Reflecting on professional development

This paper describes how a cluster of ten secondary science teachers from six different schools and colleges in the UK designed and undertook small-scale action research projects as an approach to their own Continuing Professional Development (CPD). The participating teachers identified a range of topics for investigation such as student voice, engagement and motivation in STEM (Science Technology Engineering Mathematics) learning and effective practical work. They brought their research into practice either as individuals, pairs or within a team. Central to each project was the use of reflection as a primary tool for ensuring the impact of the professional development and for stimulating a teacher-led process. Reflective practice was developed through the use of three approaches; audio sound bites, reflective blogs, and reflective discussions. The teachers used reflection as a means of self-evaluation as well as evaluation of their action research interventions. The reflective practice which the teachers engaged in enabled them to think carefully about what was taking place in a given situation during their designed interventions, to identify suitable options, and to make conscious choices about what to do in order to make a difference. The participating teachers all concluded that reflective methods that enable self-reflection as well as reflection upon designed classroom interventions are hugely beneficial to effective CPD for teachers

A scientific cognitive-behavioral model of tinnitus: novel conceptualizations of tinnitus distress.

The importance of psychological factors in tinnitus distress has been formally recognized for almost three decades. The psychological understanding of why tinnitus can be a distressing condition posits that it becomes problematic when it acquires an emotive significance through cognitive processes. Principle therapeutic efforts are directed at reducing or removing the cognitive (and behavioral) obstacles to habituation. Here, the evidence relevant to a new psychological model of tinnitus is critically reviewed. The model posits that patients’ interpretations of tinnitus and the changes in behavior that result are given a central role in creating and maintaining distress. The importance of selective attention and the possibility that this leads to distorted perception of tinnitus is highlighted. From this body of evidence, we propose a coherent cognitive behavioral model of tinnitus distress that is more in keeping with contemporary psychological theories of clinical problems (particularly that of insomnia) and which postulates a number of behavioral processes that are seen as cognitively mediated. This new model provides testable hypotheses to guide future research to unravel the complex mechanisms underpinning tinnitus distress. It is also well suited to define individual symptomatology and to provide a framework for the delivery of cognitive- behavioral therapy

A quantum Monte-Carlo method for fermions, free of discretization errors

In this work we present a novel quantum Monte-Carlo method for fermions, based on an exact decomposition of the Boltzmann operator $exp(-\beta H)$. It can be seen as a synthesis of several related methods. It has the advantage that it is free of discretization errors, and applicable to general interactions, both for ground-state and finite-temperature calculations. The decomposition is based on low-rank matrices, which allows faster calculations. As an illustration, the method is applied to an analytically solvable model (pairing in a degenerate shell) and to the Hubbard model.Comment: 5 pages, 4 figures, submitted to Phys. Rev. Let

Effects of intrabilayer coupling on the magnetic properties of YBa2_2Cu3_3O6_6

A two-layer Heisenberg antiferromagnet is studied as a model of the bilayer cuprate YBa$_2$Cu$_3$O$_6$. Quantum Monte Carlo results are presented for the temperature dependence of the spin correlation length, the static structure factor, the magnetic susceptibility, and the $^{63}$Cu NMR spin-echo decay rate $1/T_{2G}$. As expected, when the ratio $J_2/J_1$ of the intrabilayer and in-plane coupling strengths is small, increasing $J_2$ pushes the system deeper inside the renormalized classical regime. Even for $J_2/J_1$ as small as $0.1$ the correlations are considerably enhanced at temperatures as high as $T/J_1 \approx 0.4-0.5$. This has a significant effect on $1/T_{2G}$, and it is suggested that measurements of this quantity at high temperatures can reveal the strength of the intrabilayer coupling in YBa$_2$Cu$_3$O$_6$.Comment: 10 pages (Revtex) + 5 uuencoded ps figures. To appear in Phys. Rev. B, Rapid Com

Critical temperature and the transition from quantum to classical order parameter fluctuations in the three-dimensional Heisenberg antiferromagnet

We present results of extensive quantum Monte Carlo simulations of the three-dimensional (3D) S=1/2 Heisenberg antiferromagnet. Finite-size scaling of the spin stiffness and the sublattice magnetization gives the critical temperature Tc/J = 0.946 +/- 0.001. The critical behavior is consistent with the classical 3D Heisenberg universality class, as expected. We discuss the general nature of the transition from quantum mechanical to classical (thermal) order parameter fluctuations at a continuous Tc > 0 phase transition.Comment: 5 pages, Revtex, 4 PostScript figures include

Exact, Complete, and Universal Continuous-Time Worldline Monte Carlo Approach to the Statistics of Discrete Quantum Systems

We show how the worldline quantum Monte Carlo procedure, which usually relies on an artificial time discretization, can be formulated directly in continuous time, rendering the scheme exact. For an arbitrary system with discrete Hilbert space, none of the configuration update procedures contain small parameters. We find that the most effective update strategy involves the motion of worldline discontinuities (both in space and time), i.e., the evaluation of the Green's function. Being based on local updates only, our method nevertheless allows one to work with the grand canonical ensemble and non-zero winding numbers, and to calculate any dynamic correlation function as easily as expectation values of, e.g., total energy. The principles found for the update in continuous time generalize to any continuous variables in the space of discrete virtual transitions, and in principle also make it possible to simulate continuous systems exactly.Comment: revtex, 14 pages, 6 figures, published version (modified and extended

Recent Developments of World-Line Monte Carlo Methods

World-line quantum Monte Carlo methods are reviewed with an emphasis on breakthroughs made in recent years. In particular, three algorithms -- the loop algorithm, the worm algorithm, and the directed-loop algorithm -- for updating world-line configurations are presented in a unified perspective. Detailed descriptions of the algorithms in specific cases are also given.Comment: To appear in Journal of Physical Society of Japa