More than Words: The Impact of Memory on How Undergraduates with Dyslexia Interact with Information

Despite the prevalence of dyslexia and the challenges it poses for seeking, assessing and using information, there has been relatively little research on the challenges people with dyslexia face when interacting with information. What existing research there is has mostly focused on the impact on information comprehension and spelling. However, people with dyslexia often face considerable memory impairment that can affect their learning. This paper reports findings from retrospective think-aloud (RTA) observations with 13 undergraduates with dyslexia, focusing on the memory-related barriers they face and the workarounds they use to overcome these barriers. An enhanced understanding of the full range of barriers faced by information-seekers with dyslexia can inform the design of dyslexia-aware digital information environments and information literacy programs. These can ‘level the information playing field’ by helping to break down barriers to information and, in turn, to knowledge creation

Group Theoretical Foundations of Fractional Supersymmetry

Fractional supersymmetry denotes a generalisation of supersymmetry which may be constructed using a single real generalised Grassmann variable, $\theta = \bar{\theta}, \, \theta^n = 0$, for arbitrary integer $n = 2, 3, ...$. An explicit formula is given in the case of general $n$ for the transformations that leave the theory invariant, and it is shown that these transformations possess interesting group properties. It is shown also that the two generalised derivatives that enter the theory have a geometric interpretation as generators of left and right transformations of the fractional supersymmetry group. Careful attention is paid to some technically important issues, including differentiation, that arise as a result of the peculiar nature of quantities such as $\theta$.Comment: Plain Latex, 18 page

Galactic Archaeology and Minimum Spanning Trees

Chemical tagging of stellar debris from disrupted open clusters and associations underpins the science cases for next-generation multi-object spectroscopic surveys. As part of the Galactic Archaeology project TraCD (Tracking Cluster Debris), a preliminary attempt at reconstructing the birth clouds of now phase-mixed thin disk debris is undertaken using a parametric minimum spanning tree (MST) approach. Empirically-motivated chemical abundance pattern uncertainties (for a 10-dimensional chemistry-space) are applied to NBODY6-realised stellar associations dissolved into a background sea of field stars, all evolving in a Milky Way potential. We demonstrate that significant population reconstruction degeneracies appear when the abundance uncertainties approach 0.1 dex and the parameterised MST approach is employed; more sophisticated methodologies will be required to ameliorate these degeneracies.Comment: To appear in "Multi-Object Spectroscopy in the Next Decade: Big Questions, Large Surveys and Wide Fields"; Held: Santa Cruz de La Palma, Canary Islands, Spain, 2-6 Mar 2015; ed. I Skillen & S. Trager; ASP Conference Series (Figures now optimised for B&W printing

Quantum mechanics over a q-deformed (0+1)-dimensional superspace

We built up a explicit realization of (0+1)-dimensional q-deformed superspace coordinates as operators on standard superspace. A q-generalization of supersymmetric transformations is obtained, enabling us to introduce scalar superfields and a q-supersymmetric action. We consider a functional integral based on this action. Integration is implemented, at the level of the coordinates and at the level of the fields, as traces over the corresponding representation spaces. Evaluation of these traces lead us to standard functional integrals. The generation of a mass term for the fermion field leads, at this level, to an explicitely broken version of supersymmetric quantum mechanics.Comment: 11 pages, Late

Numerical Modeling Of Hohlraum Radiation Conditions: Spatial And Spectral Variations Due To Sample Position, Beam Pointing, And Hohlraum Geometry

View-factor simulations are presented of the spatially varying radiation conditions inside double-ended gold Hohlraums and single-ended gold Hohlraums (\u27\u27 halfraums \u27\u27) used in inertial confinement fusion and high-energy density physics experiments [J. Lindl, Phys. Plasmas 11, 339 (2004); M. D. Rosen, Phys. Plasmas 3, 1803 (1996)]. It is shown that in many circumstances, the common assumption that the Hohlraum \u27\u27 drive \u27\u27 can be characterized by a single temperature is too simplistic. Specifically, the radiation conditions seen by an experimental package can differ significantly from the wall reemission measured through diagnostic holes or laser entrance holes (LEHs) by absolutely calibrated detectors. Furthermore, even in situations where the radiation temperature is roughly the same for diagnostics and experimental packages, or for packages at different locations, the spectral energy distributions can vary significantly, due to the differing fractions of reemitting wall, laser hot spots, and LEHs seen from different locations. We find that the spatial variation of temperature and especially the differences between what diagnostics looking in the LEH measure versus the radiation temperature on wall-mounted experimental packages are generally greater for double-ended Hohlraums than for halfraums. View-factor simulations can also be used to explore experimental variables (halfraum length and geometry, sample position, and beam pointing) that can be adjusted in order to, for example, maximize the radiation flux onto a sample, or other package. In this vein, simulations of Hohlraums and halfraums with LEH shields are also presented. (c) 2005 American Institute of Physics

Does dyslexia present barriers to information literacy in an online environment? A pilot studynformation Research

The skills and attributes required to become information literate have not been analysed from the perspective of information users with cognitive disabilities, such as dyslexia, and this research seeks to begin to address this gap in the literature. The initial objective of the research was to collect data showing the online search strategies of dyslexics and non-dyslexics who are in Higher Education, highlighting any areas of difference and difficulty. The results of a pilot study comparing the online search behaviour of seven dyslexic participants with that of seven who were non-dyslexic, are reported here. Participants were adult undergraduates, taken from all three levels of study. Participants were interviewed and their online information searching behaviour was observed through the collection of screen recording diaries over the completion period of one assignment. Within the dyslexic group, difficulties were reported and observed in the areas of keyword creation, use of appropriate tools to refine and expand searches and the evaluation of sources. The dyslexics' group low selfefficacy in many of the skills associated with information literacy was discovered to be notable barrier

Information behaviour of music record collectors

Introduction: Using Stebbins's concept of 'serious leisure' and Savolainen's concept of 'everyday life information practices', this study explores the information behaviour of music record collectors. Method: An ethnographic approach was used for the study; the main data collection instrument was in-depth, semi-structured interviews with eight record collectors based in and around London, carried out in participants' homes, combined with photographs of their collections and observation of their use of preferred Websites. Analysis: Qualitative analysis was carried out on the survey, with triangulation through conversations with other record collectors, visits to record shops, and examination of some Websites named by participants. Results: The results reveal distinctive information behaviour for record collectors, with specialist knowledge, and a variety of information sources. The Internet has had, and continues to have, a profound effect on both information gathering and acquisition. Conclusions: The study shows that record collectors are exemplars of serious leisure practitioners, with distinct information behaviour. The results add to the knowledge of serious leisure as a topic for study within information science

New Challenges For Wind Shock Models: The Chandra Spectrum Of The Hot Star Delta Orionis

The Chandra spectrum of delta Ori A shows emission lines from hydrogen- and helium-like states of Si, Mg, Ne, and O, along with N VII Lyalpha and lines from ions in the range Fe XVII-Fe XXI In contrast to the broad lines seen in zeta Pup and zeta Ori (850 +/- 40 and 1000 +/- 240 km s(-1) half-width at half-maximum [HWHM], respectively), these lines are broadened to only 430 +/- 60 km s(-1) HWHM. This is much lower than the measured wind terminal velocity of 2000 km s(-1). The forbidden, intercombination, and resonance (fir) lines from He-like ions indicate that the majority of the X-ray line emission does not originate at the base of the wind, in agreement with the standard wind shock models for these objects. However, in that model the X-ray emission is distributed throughout an expanding, X-ray-absorbing wind, and it is therefore surprising that the emission lines appear relatively narrow, unshifted, and symmetric. We compare the observed line profiles to recent detailed models for X-ray line pro le generation in hot stars, but none of them offers a fully satisfactory explanation for the observed line profiles

Quantum Field Theory with Nonzero Minimal Uncertainties in Positions and Momenta

A noncommutative geometric generalisation of the quantum field theoretical framework is developed by generalising the Heisenberg commutation relations. There appear nonzero minimal uncertainties in positions and in momenta. As the main result it is shown with the example of a quadratically ultraviolet divergent graph in $\phi^4$ theory that nonzero minimal uncertainties in positions do have the power to regularise. These studies are motivated with the ansatz that nonzero minimal uncertainties in positions and in momenta arise from gravity. Algebraic techniques are used that have been developed in the field of quantum groups.Comment: 52 pages LATEX, DAMTP/93-33. Revised version now includes a chapter on the Poincare algebra and curvature as noncommutativity of momentum spac