Visual complexity, player experience, performance and physical exertion in motion-based games for older adults

Motion-based video games can have a variety of benefits for the players and are increasingly applied in physical therapy, rehabilitation and prevention for older adults. However, little is known about how this audience experiences playing such games, how the player experience affects the way older adults interact with motion-based games, and how this can relate to therapy goals. In our work, we decompose the player experience of older adults engaging with motion-based games, focusing on the effects of manipulations of the game representation through the visual channel (visual complexity), since it is the primary interaction modality of most games and since vision impairments are common amongst older adults. We examine the effects of different levels of visual complexity on player experience, performance, and exertion in a study with fifteen participants. Our results show that visual complexity affects the way games are perceived in two ways: First, while older adults do have preferences in terms of visual complexity of video games, notable effects were only measurable following drastic variations. Second, perceived exertion shifts depending on the degree of visual complexity. These findings can help inform the design of motion-based games for therapy and rehabilitation for older adults

An Action-Based Approach to Presence: Foundations and Methods

This chapter presents an action-based approach to presence. It starts by briefly describing the theoretical and empirical foundations of this approach, formalized into three key notions of place/space, action and mediation. In the light of these notions, some common assumptions about presence are then questioned: assuming a neat distinction between virtual and real environments, taking for granted the contours of the mediated environment and considering presence as a purely personal state. Some possible research topics opened up by adopting action as a unit of analysis are illustrated. Finally, a case study on driving as a form of mediated presence is discussed, to provocatively illustrate the flexibility of this approach as a unified framework for presence in digital and physical environment

The Chromomagnetic Dipole Operator and the B Semileptonic Branching Ratio

We consider the possibility of having a large branching ratio for the decay $b\to s g$ coming from an enhanced Wilson coefficient of the chromomagnetic dipole operator. We show that values of $BR(b\to s g)$ up to $\sim 10\%$ or more are compatible with the constraints coming from the CLEO experimental results on $BR(B\to X_s\gamma)$ and $BR(B\to X_s\phi)$. Such large values can reconcile the predictions of both the semileptonic branching ratio and the charm counting with the present experimental results. We also discuss a supersymmetric model with gluino-mediated flavour violations, which can account for such large values of $BR(b\to s g)$.Comment: 19 pages, 3 eps figures included, replacement with minor change

Zeroing In On the Top Quark, LSP and Scalar Higgs Masses

We estimate the top quark, lightest sparticle (LSP) and scalar higgs masses within a supersymmetric grand unified framework in which $\tan\beta \simeq m_t/m_b$ and the electroweak symmetry is radiatively broken. The requirement that the calculated $b$ quark mass lie close to its measured value, together with the cosmological constraint $\Omega_{LSP} \approx 1$, fixes the top quark mass to be $m_t(m_t) \approx 170 \pm 15\ GeV$. The LSP (of bino purity $\stackrel{_>}{_\sim} 98\%)$ has mass $\sim 200 - 350\ GeV$. In the scalar higgs sector the CP-odd scalar mass $m_A \stackrel{_<}{_\sim} 220\ GeV$. With $m_A \stackrel{_>}{_\sim} M_Z$, as suggested by the decay $b \rightarrow s\gamma$, we find $M_Z \stackrel{_<}{_\sim} m_{h^0} (m_{H^0}) \stackrel{_<}{_\sim} 140 (220)\ GeV$ and $120\ GeV \stackrel{_<}{_\sim} m_{H^\pm} \stackrel{_<}{_\sim} 240\ GeV$.Comment: 14 pages in plain LaTeX, BA-93-25, PRL-TH-93/

Supersymmetric Scenarios with Dominant Radiative Neutralino Decay

The radiative decay of the next-to-lightest neutralino into a lightest neutralino and a photon is analyzed in the MSSM. We find that significant regions of the supersymmetric parameter space with large radiative BR's (up to about 100%) do exist. The radiative channel turns out to be enhanced when the neutralino tree-level decays are suppressed either "kinematically" or "dynamically". In general, in the regions allowed by LEP data and not characterized by asymptotic values of the SuSy parameters, the radiative enhancement requires tan beta ~= 1 and/or M_1 ~= M_2, and negative values of \mu. We present typical specific scenarios where these "necessary" conditions are fulfilled, relaxing the usual relation M_1=(5/3)*tan^2(th_W)*M_2. The influence of varying the stop masses and mixing angle when the radiative decay is enhanced is also considered. Some phenomenological consequences of the above picture are discussed.Comment: 32 pages, LaTeX file + 23 figures embedded with epsf.sty. In this revised version, Eq.(3) plus some related notations and text passages have been changed. Minor error corrected in Fig.12(a). The numerical analysis and the conclusions of the paper are not affected. (Includes the erratum to appear in Phys. Rev. D.) Source and ps files are also available at ftp://hpteo.roma1.infn.it/pub/preprints/ambr-mele/Rome1-1148/ or at http://feynman.physics.lsa.umich.edu/~ambros/Physics.html#1

The dilaton-dominated supersymmetry breaking scenario in the context of the non-minimal supersymmetric model

The phenomenological consequences of the dilaton-type soft supersymmetry breaking terms in the context of the next to minimal supersymmetric standard model are investigated. We always find a very low top quark mass. As a consequence such string vacua are excluded by recent experimental results. The viability of the solution of the $\mu$ term through the introduction of a gauge singlet field is also briefly discussed.Comment: 10 pages,LATE

b-tau Unification and neutrino masses in SU(5) extensions of the MSSM with radiative electroweak symmetry breaking

We make a complete analysis of the Yukawa coupling unification in SU(5) extensions of the MSSM in the framework of the radiative symmetry breaking scenario. Both logarithmic and finite threshold corrections of sparticles have been included in the determination of the gauge and Yukawa couplings at M_Z. The effect of the heavy masses of each model in the renormalization group equations is also included. We find that in the minimal SU(5) model b-tau Yukawa unification can be achieved for too large a value of alpha_s. On the other hand the Peccei-Quinn version of the Missing Doublet model, with the effect of the right handed neutrino also included, exhibits b-tau unification in excellent agreement with all low energy experimental data. Unification of all Yukawa couplings is also discussed.Comment: 20 pages, LaTeX2e,uses psfig,5 figures,full postscript file available at http://artemis.cc.uoi.gr/~adedes/new97.ps.g

Facilitators and Barriers to Adaptive Implementation of the Meeting Centers Support Program (MCSP) in Three European Countries; the Process Evaluation Within the MEETINGDEM Study

Background: In the MEETINGDEM project, the Meeting Centers Support Program (MCSP) was adaptively implemented and evaluated in three European countries: Italy, Poland, and the United Kingdom. The aim of this study was to investigate overall and country-specific facilitators and barriers to the implementation of MCSP in these European countries. Methods: A qualitative multiple case study design was used. Based on the theoretical model of adaptive implementation, a checklist was composed of potential facilitators and barriers to the implementation of MCSP. This checklist was administered among stakeholders involved in the implementation of MCSP to trace the experienced facilitators and barriers. Twenty-eight checklists were completed. Results: Main similarities between countries were related to the presence of suitable staff, management, and a project manager, and the fact that the MCSP is attuned to needs and wishes of people with dementia and informal caregivers. Main differences between countries were related to: communication with potential referrers, setting up an inter-organizational collaboration network, receiving support of national organizations, having clear discharge criteria for the MCSP and continuous PR in the region. Conclusion: The results of this study provide insight into generic and country specific factors that can influence the implementation of MCSP in different European countries. This study informs further implementation and dissemination of MCSP in Europe and may also serve as an example for the dissemination and implementation of other effective psychosocial support interventions for people with dementia and their informal caregivers across and beyond Europe

The Neutralino Relic Density in Minimal N=1 Supergravity

We compute the cosmic relic (dark matter) density of the lightest supersymmetric particle (LSP) in the framework of minimal $N=1$ Supergravity models with radiative breaking of the electroweak gauge symmetry. To this end, we re--calculate the cross sections for all possible annihilation processes for a general, mixed neutralino state with arbitrary mass. Our analysis includes effects of all Yukawa couplings of third generation fermions, and allows for a fairly general set of soft SUSY breaking parameters at the Planck scale. We find that a cosmologically interesting relic density emerges naturally over wide regions of parameter space. However, the requirement that relic neutralinos do not overclose the universe does not lead to upper bounds on SUSY breaking parameters that are strictly valid for all combinations of parameters and of interest for existing or planned collider experiments; in particular, gluino and squark masses in excess of 5 TeV cannot strictly be excluded. On the other hand, in the ``generic'' case of a gaugino--like neutralino whose annihilation cross sections are not ``accidentally'' enhanced by a nearby Higgs or $Z$ pole, all sparticles should lie within the reach of the proposed $pp$ and $e^+e^-$ supercolliders. We also find that requiring the LSP to provide all dark matter predicted by inflationary models imposes a strict lower bound of 40 GeV on the common scalar mass $m$ at the Planck scale, while the lightest sleptons would have to be heavierComment: 53 pages(8figs are not included), Latex file; DESY 92-101, SLAC-PUB-586

Neutralino-Nucleon Cross Section and Charge and Colour Breaking Constraints

We compute the neutralino-nucleon cross section in several supersymmetric scenarios, taking into account all kind of constraints. In particular, the constraints that the absence of dangerous charge and colour breaking minima imposes on the parameter space are studied in detail. In addition, the most recent experimental constraints, such as the lower bound on the Higgs mass, the $b\to s\gamma$ branching ratio, and the muon $g-2$ are considered. The astrophysical bounds on the dark matter density are also imposed on the theoretical computation of the relic neutralino density, assuming thermal production. This computation is relevant for the theoretical analysis of the direct detection of dark matter in current experiments. We consider first the supergravity scenario with universal soft terms and GUT scale. In this scenario the charge and colour breaking constraints turn out to be quite important, and \tan\beta\lsim 20 is forbidden. Larger values of $\tan\beta$ can also be forbidden, depending on the value of the trilinear parameter $A$. Finally, we study supergravity scenarios with an intermediate scale, and also with non-universal scalar and gaugino masses where the cross section can be very large.Comment: Final version to appear in JHE