9,870 research outputs found

    Why can't every year be a National Year of Reading? An evaluation of the NYR in Yorkshire

    Get PDF
    An evaluation of the National Year of Reading in Yorkshire was conducted by Leeds Metropolitan University in response to a brief from Museums, Libraries and Archives, Yorkshire. This paper outlines the development and planning of phase one of this small scale qualitative research project and the analysis of the initial results which looks at the impact of NYR on the organisations that delivered the campaign and their work with target groups. The Generic Social Outcomes and the National Indicators were used to develop a theoretical framework. Data were gathered via in depth interviews and focus groups with NYR steering group partners in Calderdale and North Lincolnshire, selected as the two case study authorities. The use of MAXQDA computer-assisted qualitative data analysis software (CAQDAS) enabled data and coding structures to be stored and will facilitate comparison in this longitudinal study. This evaluation will provide material that local library authorities can use for advocacy with a range of audiences including local and central government

    Enhancements to the STAGS computer code

    Get PDF
    The power of the STAGS family of programs was greatly enhanced. Members of the family include STAGS-C1 and RRSYS. As a result of improvements implemented, it is now possible to address the full collapse of a structural system, up to and beyond critical points where its resistance to the applied loads vanishes or suddenly changes. This also includes the important class of problems where a multiplicity of solutions exists at a given point (bifurcation), and where until now no solution could be obtained along any alternate (secondary) load path with any standard production finite element code

    Revised Pulsar Spindown

    Full text link
    We address the issue of electromagnetic pulsar spindown by combining our experience from the two limiting idealized cases which have been studied in great extent in the past: that of an aligned rotator where ideal MHD conditions apply, and that of a misaligned rotator in vacuum. We construct a spindown formula that takes into account the misalignment of the magnetic and rotation axes, and the magnetospheric particle acceleration gaps. We show that near the death line aligned rotators spin down much slower than orthogonal ones. In order to test this approach, we use a simple Monte Carlo method to simulate the evolution of pulsars and find a good fit to the observed pulsar distribution in the P-Pdot diagram without invoking magnetic field decay. Our model may also account for individual pulsars spinning down with braking index n < 3, by allowing the corotating part of the magnetosphere to end inside the light cylinder. We discuss the role of magnetic reconnection in determining the pulsar braking index. We show, however, that n ~ 3 remains a good approximation for the pulsar population as a whole. Moreover, we predict that pulsars near the death line have braking index values n > 3, and that the older pulsar population has preferentially smaller magnetic inclination angles. We discuss possible signatures of such alignment in the existing pulsar data.Comment: 8 pages, 7 figures; accepted to Ap

    Duration of heart failure and the risk of atrial fibrillation: different mechanisms at different times?

    Get PDF
    Chronic heart failure increases the risk of atrial fibrillation (AF), with the prevalence of AF paralleling the severity of heart failure.1 Factors that underlie this increased susceptibility to AF may include electrical, structural, and neurohumoral changes.2 In AF, it is recognized that atrial electrophysiological remodelling occurs and contributes to the perpetuation of the arrhythmia, most notably the decrease of effective refractory period (ERP) which predisposes to re-entry by shortening the wavelength. Does heart failure cause similar changes in atrial electrophysiology that predispose to the arrhythmia

    An RG potential for the quantum Hall effects

    Full text link
    The phenomenological analysis of fully spin-polarized quantum Hall systems, based on holomorphic modular symmetries of the renormalization group (RG) flow, is generalized to more complicated situations where the spin or other "flavors" of charge carriers are relevant, and where the symmetry is different. We make the simplest possible ansatz for a family of RG potentials that can interpolate between these symmetries. It is parametrized by a single number aa and we show that this suffices to account for almost all scaling data obtained to date. The potential is always symmetric under the main congruence group at level two, and when aa takes certain values this symmetry is enhanced to one of the maximal subgroups of the modular group. We compute the covariant RG β\beta-function, which is a holomorphic vector field derived from the potential, and compare the geometry of this gradient flow with available temperature driven scaling data. The value of aa is determined from experiment by finding the location of a quantum critical point, i.e., an unstable zero of the β\beta-function given by a saddle point of the RG potential. The data are consistent with a∈Ra \in \mathbb{R}, which together with the symmetry leads to a generalized semi-circle law.Comment: 10 figures, sligthly updated discussion and refs, accepted for PR

    The `Periodic Nulls' of Radio Pulsar J1819+1305

    Full text link
    We present a single-pulse study of the four-component pulsar J1819+1305, whose ``null'' pulses bunch at periodic intervals of around 57 times the rotation period. The emission bursts between the null bunches exhibit characteristic modulations at two shorter periodicities of approximately 6.2 and 3 times the rotation period, the former found largely in the two outer components, and the latter only in the first component. Many bursts commence with bright emission in second component, exhibit positive six-period drift across the full profile width, and end with 3-period modulation in the leading component. The 57-period cycle can be modelled geometrically as a sparsely filled subbeam carousel with nulls appearing whenever our line of sight intersects a circulating empty region. This interpretation is compatible with other recent evidence for periodic, carousel-related nulling and appears to support the physics of a polar-gap emission model for ``drifting'' subpulses, but the subtle structure of the emission bursts defies an easy explanation.Comment: 8 pages, 9 figure

    Hearing loss and auditory processing ability in people with aphasia

    Get PDF
    BACKGROUND: Hearing loss can add to the linguistic deficits present in aphasia to make comprehension of speech difficult. Although some studies document a relatively high prevalence of hearing loss in adults with aphasia, many people with aphasia do not have their hearing tested. Self-reported disability measures offer a possible alternative to pure- tone audiometry when this service is not readily available. AIMS: This study aims to investigate the prevalence of hearing loss in a group of people with aphasia and to determine the usefulness of self-reported measures to screen for hearing impairment. METHODS AND PROCEDURES: Hearing ability was measured using pure-tone audiometry and five measures of auditory processing, which looked at speech perception in quiet and noise, for 21 individuals with aphasia recruited from a community clinic and 21 age- matched individuals without aphasia. The Speech, Spatial and Qualities of Hearing Scale (SSQ) and a brief questionnaire exploring whether they had experienced hearing difficulties were used to measure self-perception of hearing acuity. Differences in scores between the groups were analysed. Correlations and regressions were used to establish the relationship between self-perception of hearing and measures of hearing ability. OUTCOMES AND RESULTS: Despite minimal impairment and a non-significant difference between performance on pure-tone audiometry for participants with and without apha- sia, participants with aphasia performed significantly worse on measures of speech perception in noise than participants without aphasia. They also had a significantly greater degree of perceived hearing disability. Although SSQ scores were correlated with some behavioural measures for the participants with aphasia, the SSQ only predicted the hearing status and speech in noise performance of control participants. CONCLUSIONS: The results suggest that the prevalence of hearing loss for people with aphasia (at least for this group) is no greater than the general population. However, they are significantly more affected in their recognition of speech in noise and experience greater disability in listening situations than people without aphasia. The latter problems were not predicted by pure-tone audiograms or sound-in-noise performance. The brief questionnaire was not effective in identifying hearing impairment, indicating the need for a regular hearing screen to ensure provision of the most effective rehabilitation. Ideally, the screen should include disability and behavioural measures, as our results suggest they cannot replace each other. These findings should assist clinicians in setting realistic goals and delivering interventions in the most effective way for people with aphasia
    • …
    corecore