University of Salford

About: University of Salford is a education organization based out in Salford, Manchester, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 13049 authors who have published 22957 publications receiving 537330 citations. The organization is also known as: University of Salford Manchester & The University of Salford Manchester.

Focus groups with young people: a participatory approach to research planning

Abstract: In this paper we present our experiences of conducting focus groups with young people as part of a participatory approach to research design and participant recruitment. The research is a prospective, 10-year, qualitative, longitudinal project investigating young people's daily lives, relationships, and identities, and the ways these change over time. It adopts a multi-method approach in which each participant has a choice about which methods to be involved with. Part of the project planning and recruitment was completed through focus groups held in schools across metropolitan and rural West Yorkshire with young people aged 13. The focus groups enabled us to recruit participants from a variety of backgrounds. They were also an important medium through which to elicit the views of young people (which were perceptively and constructively critical) about project design, methods development, and dissemination events. The paper focuses on what we learnt from these focus groups and considers the value of engaging participants in designing qualitative research.

Macroprolactinaemia : validation and application of the polyethylene glycol precipitation test and clinical characterization of the condition

Abstract: OBJECTIVE The clinical characteristics and natural history of macroprolactinaemia are yet to be fully established and there is currently no widely accepted simple in vitro test for routine identification of the condition. This study was designed to further validate the polyethylene glycol (PEG) precipitation test with assessment of percentage prolactin recovery (%R), for the detection of macroprolactinaemia and clinically characterize cases identified using the test. DESIGN Analytical validation and application of the PEG precipitation test for diagnosis of macroprolactinaemia and a retrospective case-notes review of some of the patients identified with the condition. PATIENTS Sera from 188 patients with elevated serum prolactin (PRL) concentrations were screened for macroprolactinaemia. Seventeen of the patients who were under follow-up at the local teaching hospital and were identified to have macroprolactinaemia were systematically characterized clinically. MEASUREMENTS Prolactin was measured in sera, fractions from gel filtration chromatography and supernatant obtained after PEG precipitation, by the DELFIA fluoroimmunoassay. CLINICAL ENDPOINTS Initial serum PRL and symptoms and their response to dopamine agonist therapy; imaging of the pituitary gland; serum PRL and symptoms after cessation of dopamine agonist therapy; course of serum PRL and symptoms without dopamine agonist therapy. RESULTS The within-batch coefficient of variation (CV) of the PEG precipitation test ranged between 2.8 and 7.3% while the between-batch CV ranged between 3.4 and 9.7%. Intra-individual variability up to five months was 9.9%. A prolactin recovery ≤ 40% was indicative of macroprolactinaemia, while the condition was unlikely to be present at values > 50%. The prevalence of macroprolactinaemia was 15% without sex difference. Clinical characterization of 17 patients showed modest initial serum PRL concentrations and there was imaging evidence of a coexisting pituitary adenoma in three of them. Dopamine agonist therapy resulted in substantial falls in serum PRL and this was associated with improvement or resolution of symptoms in some patients. Stoppage of dopamine agonist resulted in rebound hyperprolactinaemia in all cases. Spontaneous improvement in symptoms occurred in three patients but hyperprolactinaemia persisted in all those who were not on treatment. CONCLUSIONS The PEG precipitation test with assessment of ‘free’ prolactin has been shown to be reproducible and sensitive for the detection of macroprolactinaemia. Many of the patients who had macroprolactinaemia presented with at least one symptom of the hyperprolactinaemic syndrome. Dopaminergic therapy may influence the course of both serum PRL and symptoms in some of these patients.

A spacetime cloak, or a history editor

Abstract: We introduce a new type of electromagnetic cloak, the spacetime cloak (STC), which conceals events rather than objects. Non-emitting events occurring during a restricted period are never suspected by a distant observer. The cloak works by locally manipulating the speed of light of an initially uniform light distribution, whilst the light rays themselves always follow straight paths. Any 'perfect' spacetime cloak would necessarily rely upon the technology of electromagnetic metamaterials, which has already been shown to be capable of deforming light in ways hitherto unforeseen—to produce, for example, an electromagnetic object cloak. Nevertheless, we show how it is possible to use intensity-dependent refractive indices to construct an approximate STC, an implementation that would enable the distinct signature of successful event cloaking to be observed. Potential demonstrations include systems that apparently violate quantum statistics, 'interrupt-without-interrupt' computation on convergent data channels and the illusion of a Star Trek transporter.

Team performance: the case of English Premiership football

Abstract: Sporting production function studies have been almost entirely US based concentrating largely, although not exclusively, on baseball. Mainly due to a dearth of match play statistics, there have been few studies of other sports, with that of association football being a significant omission given the sport's international appeal and global coverage. This study attempts to redress the balance by utilizing a new data source, containing information on a range of specific play variables, to estimate a production function for English Premiership football. Our results emphasize the key attacking and defensive skills, and provide support for the notion that teams may intentionally employ dubious or illegal tactics to succeed. The inclusion of team effects provides evidence consistent with the view of the emergence of an elite group of clubs dominating the league. Copyright © 2000 John Wiley & Sons, Ltd.

An algorithm for Gaussian quadrature given modified moments

Abstract: An algebraic algorithm, the long quotient- modified difference (LQMD) algorithm, is described for the Gaussian quadrature of the one-dimensional product integral ?f(x)w(x)dx when the weight function ?(x) is known through modified momentsv l =; theP l (x) are any polynomials of degreel satisfying 3-term recurrence relations with known coefficients. The algorithm serves to establish the co-diagonal matrix, the eigenvalues of which are the Gaussian abscissas. Applied to ordinary moments it requires far fewer divisions than the quotient-difference algorithm; if theP l (x) are themselves orthogonal with a kernelw 0 03F0;, there is no instability due to rounding errors. For smooth kernels ?(x) it is safe to use secondorder interpolation in determining the eigenvalues by Givens' method. The Christoffel weights can be expressed as ratios of two terms which are most easily calculated in a Sturm sequence beginning with the highest value ofl. A formula for the Christoffel weights applicable for rational versions of theQR algorithm is also derived. Convergence and the propagation of rounding errors are illustrated by several examples, and anAlgol procedure is given.