Discrete and finite Genral Relativity

We develop the General Theory of Relativity in a formalism with extended causality that describes physical interaction through discrete, transversal and localized pointlike fields. The homogeneous field equations are then solved for a finite, singularity-free, point-like field that we associate to a ``classical graviton". The standard Einstein's continuous formalism is retrieved by means of an averaging process, and its continuous solutions are determined by the chosen imposed symetry. The Schwarzschild metric is obtained by the imposition of spherical symmetry on the averaged field.Comment: Modified conform the version to appear in Classical and Quantum Gravit

Young people’s experiences using electric powered indoor-outdoor wheelchairs (EPIOCs): Potential for enhancing users’ development?

Purpose: To examine the experiences of severely physically disabled young people using electric powered indoor/outdoor chairs (EPIOCs). Methods: A priori interview questions examined young people’s functioning with EPIOCs, pain and discomfort with EPIOC use and accidents or injuries resulting from EPIOC use. Eighteen young people (13 males and 5 females) aged 10 -18 (mean 15) years were interviewed by telephone using a qualitative framework approach. Participants were interviewed 10 -19 (mean 14.5) months after delivery of the chair. Diagnoses included muscular dystrophy (n = 10), cerebral palsy (n = 5), and ‘other’ (n =3). Results: Many children reported positive functioning following EPIOC use, including increased independence and social activities like wheelchair football. However, EPIOC use was also associated with pain and discomfort, as well as perceived lack of safety, and minor accidents. Most young people and their families were fairly satisfied with the service and provision of their wheelchairs. Conclusions: The findings suggest that disabled children’s development may benefit from the use of electric powered indoor/outdoor wheelchairs, although the advantages may come at certain costs to young people’s perceived and real safety. Recommendations to powered wheelchair providers include the demonstrated need for additional driving training as these young people mature

To adopt is to adapt: The process of implementing the ICF with an acute stroke multidisciplinary team in England

Copyright @ 2012 Informa Plc. The article can be accessed from the link below.This article has been made available through the Brunel Open Access Publishing Fund.Purpose: The success of the International Classification of Functioning, Disability and Health (ICF) depends on its uptake in clinical practice. This project aimed to explore ways the ICF could be used with an acute stroke multidisciplinary team and identify key learning from the implementation process. Method: Using an action research approach, iterative cycles of observe, plan, act and evaluate were used within three phases: exploratory; innovatory and reflective. Thematic analysis was undertaken, using a model of immersion and crystallisation, on data collected via interview and focus groups, e-mail communications, minutes from relevant meetings, field notes and a reflective diary. Results: Two overall themes were determined from the data analysis which enabled implementation. There is a need to: (1) adopt the ICF in ways that meet local service needs; and (2) adapt the ICF language and format. Conclusions: The empirical findings demonstrate how to make the ICF classification a clinical reality. First, we need to adopt the ICF as a vehicle to implement local service priorities e.g. to structure a multidisciplinary team report, thus enabling ownership of the implementation process. Second, we need to adapt the ICF terminology and format to make it acceptable for use by clinicians.This study is funded by The Elizabeth Casson Trust. This article is made available through the Brunel Open Access Publishing Fund

Noether symmetry for non-minimally coupled fermion fields

A cosmological model where a fermion field is non-minimally coupled with the gravitational field is studied. By applying Noether symmetry the possible functions for the potential density of the fermion field and for the coupling are determined. Cosmological solutions are found showing that the non-minimally coupled fermion field behaves as an inflaton describing an accelerated inflationary scenario, whereas the minimally coupled fermion field describes a decelerated period being identified as dark matter.Comment: Revised version accepted for publication in Classical and Quantum Gravit

Remarks on supersymmetry of quantum systems with position-dependent effective masses

We apply the supersymmetry approach to one-dimensional quantum systems with spatially-dependent mass, by including their ordering ambiguities dependence. In this way we extend the results recently reported in the literature. Furthermore, we point out a connection between these systems and others with constant masses. This is done through convenient transformations in the coordinates and wavefunctions.Comment: 8 pages, 1 figur