1,097 research outputs found
Attention and Social Cognition in Virtual Reality:The effect of engagement mode and character eye-gaze
Technical developments in virtual humans are manifest in modern character design. Specifically, eye gaze offers a significant aspect of such design. There is need to consider the contribution of participant control of engagement. In the current study, we manipulated participants’ engagement with an interactive virtual reality narrative called Coffee without Words. Participants sat over coffee opposite a character in a virtual café, where they waited for their bus to be repaired. We manipulated character eye-contact with the participant. For half the participants in each condition, the character made no eye-contact for the duration of the story. For the other half, the character responded to participant eye-gaze by making and holding eye contact in return. To explore how participant engagement interacted with this manipulation, half the participants in each condition were instructed to appraise their experience as an artefact (i.e., drawing attention to technical features), while the other half were introduced to the fictional character, the narrative, and the setting as though they were real. This study allowed us to explore the contributions of character features (interactivity through eye-gaze) and cognition (attention/engagement) to the participants’ perception of realism, feelings of presence, time duration, and the extent to which they engaged with the character and represented their mental states (Theory of Mind). Importantly it does so using a highly controlled yet ecologically valid virtual experience
Topcolor-Assisted Supersymmetry
It has been known that the supersymmetric flavor changing neutral current
problem can be avoided if the squarks take the following mass pattern, namely
the first two generations with the same chirality are degenerate with masses
around the weak scale, while the third generation is very heavy. We realize
this scenario through the supersymmetric extension of a topcolor model with
gauge mediated supersymmetry breaking.Comment: 12 pages, latex, no figure
Shock waves in two-dimensional granular flow: effects of rough walls and polydispersity
We have studied the two-dimensional flow of balls in a small angle funnel,
when either the side walls are rough or the balls are polydisperse. As in
earlier work on monodisperse flows in smooth funnels, we observe the formation
of kinematic shock waves/density waves. We find that for rough walls the flows
are more disordered than for smooth walls and that shock waves generally
propagate more slowly. For rough wall funnel flow, we show that the shock
velocity and frequency obey simple scaling laws. These scaling laws are
consistent with those found for smooth wall flow, but here they are cleaner
since there are fewer packing-site effects and we study a wider range of
parameters. For pipe flow (parallel side walls), rough walls support many shock
waves, while smooth walls exhibit fewer or no shock waves. For funnel flows of
balls with varying sizes, we find that flows with weak polydispersity behave
qualitatively similar to monodisperse flows. For strong polydispersity, scaling
breaks down and the shock waves consist of extended areas where the funnel is
blocked completely.Comment: 11 pages, 15 figures; accepted for PR
Pan-European early switch/early discharge opportunities exist for hospitalised patients with methicillin-resistant <em>Staphylococcus</em> <em>aureus</em> complicated skin and soft-tissue infections
AbstractThe objective of this study was to document pan-European real-world treatment patterns and healthcare resource use and estimate opportunities for early switch (ES) from intravenous (IV) to oral antibiotics and early discharge (ED) in hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infections (cSSTIs). This retrospective observational medical chart review study enrolled 342 physicians across 12 European countries who collected data from 1542 patients with documented MRSA cSSTI who were hospitalized (July 2010 to June 2011) and discharged alive (by July 2011). Data included clinical characteristics and outcomes, hospital length of stay (LOS), MRSA-targeted IV and oral antibiotic use, and ES and ED eligibility according to literature-based and expert-validated criteria. The most frequent initial MRSA-active antibiotics were vancomycin (50.2%), linezolid (15.1%), clindamycin (10.8%), and teicoplanin (10.4%). Patients discharged with MRSA-active antibiotics (n = 480) were most frequently prescribed linezolid (42.1%) and clindamycin (19.8%). IV treatment duration (9.3 ± 6.5 vs. 14.6 ± 9.9 days; p <0.001) and hospital LOS (19.1 ± 12.9 vs. 21.0 ± 18.2 days; p 0.162) tended to be shorter for patients switched from IV to oral treatment than for patients who received IV treatment only. Of the patients, 33.6% met ES criteria and could have discontinued IV treatment 6.0 ± 5.5 days earlier, and 37.9% met ED criteria and could have been discharged 6.2 ± 8.2 days earlier. More than one-third of European patients hospitalized for MRSA cSSTI could be eligible for ES and ED, resulting in substantial reductions in IV days and bed-days, with potential savings of €2000 per ED-eligible patient
Probing Heavy Higgs Boson Models with a TeV Linear Collider
The last years have seen a great development in our understanding of particle
physics at the weak scale. Precision electroweak observables have played a key
role in this process and their values are consistent, within the Standard Model
interpretation, with a light Higgs boson with mass lower than about 200 GeV. If
new physics were responsible for the mechanism of electroweak symmetry
breaking, there would, quite generally, be modifications to this prediction
induced by the non-standard contributions to the precision electroweak
observables. In this article, we analyze the experimental signatures of a heavy
Higgs boson at linear colliders. We show that a linear collider, with center of
mass energy \sqrt{s} <= 1 TeV, would be very useful to probe the basic
ingredients of well motivated heavy Higgs boson models: a relatively heavy
SM-like Higgs, together with either extra scalar or fermionic degrees of
freedom, or with the mixing of the third generation quarks with non-standard
heavy quark modes.Comment: 21 page
On the origin of the A and B electronic Raman scattering peaks in the superconducting state of YBaCuO
The electronic Raman scattering has been investigated in optimally oxygen
doped YBaCuO single crystals as well as in crystals
with non-magnetic, Zn, and magnetic, Ni, impurities. We found that the
intensity of the A peak is impurity independent and their energy to
ratio is almost constant (). Moreover, the
signal at the B channel is completely smeared out when non-magnetic Zn
impurities are present. These results are qualitatively interpreted in terms of
the Zeyher and Greco's theory that relates the electronic Raman scattering in
the A and B channels to \textit{d}-CDW and superconducting order
parameters fluctuations, respectively.Comment: Submited to Phys. Rev. Let
High-Energy Symmetry of Bosonic Open String Theory in the Light-like Linear Dilaton Background
High-energy limits of fixed-angle tree-level stringy scattering amplitudes in
the light-like linear dilaton background are calculated. Treating the time
component of the gradient of light-like dilaton field (V_0) as a moduli
parameter, we show that: (1) there exists a new fixed-point (V_0/E \to \infty)
in the moduli space of the bosonic open string theory, where a new high-energy
symmetry among scattering amplitudes can be identified, (2) this new symmetry
can be interpreted as a deformation of the flat-space high-energy symmetry, as
proposed by D. Gross. Hence, our results give a concrete illustration about the
relation between high-energy stringy symmetry and the background independent
formulation of string theory.Comment: 42pages, 3figures, 5tables, typos corrected, commments and reference
added
Entanglement capability of self-inverse Hamiltonian evolution
We determine the entanglement capability of self-inverse Hamiltonian
evolution, which reduces to the known result for Ising Hamiltonian, and
identify optimal input states for yielding the maximal entanglement rate. We
introduce the concept of the operator entanglement rate, and find that the
maximal operator entanglement rate gives a lower bound on the entanglement
capability of a general Hamiltonian.Comment: 4 pages, no figures. Version 3: small change
1/f Noise in Electron Glasses
We show that 1/f noise is produced in a 3D electron glass by charge
fluctuations due to electrons hopping between isolated sites and a percolating
network at low temperatures. The low frequency noise spectrum goes as
\omega^{-\alpha} with \alpha slightly larger than 1. This result together with
the temperature dependence of \alpha and the noise amplitude are in good
agreement with the recent experiments. These results hold true both with a
flat, noninteracting density of states and with a density of states that
includes Coulomb interactions. In the latter case, the density of states has a
Coulomb gap that fills in with increasing temperature. For a large Coulomb gap
width, this density of states gives a dc conductivity with a hopping exponent
of approximately 0.75 which has been observed in recent experiments. For a
small Coulomb gap width, the hopping exponent approximately 0.5.Comment: 8 pages, Latex, 6 encapsulated postscript figures, to be published in
Phys. Rev.
Discrete symmetries, invisible axion and lepton number symmetry in an economic 3-3-1 model
We show that Peccei-Quinn and lepton number symmetries can be a natural
outcome in a 3-3-1 model with right-handed neutrinos after imposing a Z_11 x
Z_2 symmetry. This symmetry is suitably accommodated in this model when we
augmented its spectrum by including merely one singlet scalar field. We work
out the breaking of the Peccei-Quinn symmetry, yielding the axion, and study
the phenomenological consequences. The main result of this work is that the
solution to the strong CP problem can be implemented in a natural way, implying
an invisible axion phenomenologically unconstrained, free of domain wall
formation and constituting a good candidate for the cold dark matter.Comment: 17 pages, Revtex
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