2,200 research outputs found
Soft Tissue to Hard Tissue Advancement Ratios for Mandibular Elongation Using Distraction Osteogenesis in Children
Distraction osteogenesis is extensively used for the elongation of hypoplastic mandibles in children, yet the soft tissue profile response to this is not well understood. The pre- and posttreatment lateral cephalometric radiographs of 27 pediatric patients who underwent bilateral mandibular elongation using distraction osteogenesis were analyzed retrospectively to correlate horizontal soft tissue advancement with horizontal underlying bone advancement at B point and pogonion. Horizontal advancement (in millimeters) of bone and overlying soft tissue at these points was collected from the radiographs of each patient, and linear regression analysis was performed to determine the relationship of hard to soft tissue horizontal advancement at these points. A 1:0.90 mean ratio of bone to soft tissue advancement was observed at B point/labiomental sulcus and at pogonion/soft tissue pogonion (linear regression analysis demonstrated slopes [β1 values] of 0.94 and 0.92, respectively). These ratios were consistent throughout the sample population and are highly predictive of the soft tissue response that can be anticipated. Magnitude of advancement, age, and sex of the patient had no effect on these ratios in our population. This study assists with our understanding of the soft tissue response that accompanies bony elongation during distraction osteogenesis which will allow us to more effectively treatment plan the orthodontic and surgical intervention that will optimize the patients\u27 functional and esthetic outcome
Soma: live performance where congruent musical, visual, and proprioceptive stimuli fuse to form a combined aesthetic narrative
Artists and scientists have long had an interest in the relationship between music and visual art. Today, many occupy themselves with correlated animation and music, called 'visual music'. Established tools and paradigms for performing live visual music however, have several limitations:
Virtually no user interface exists, with an expressivity comparable to live musical performance.
Mappings between music and visuals are typically reduced to the music‘s beat and amplitude being statically associated to the visuals, disallowing close audiovisual congruence, tension and release, and suspended expectation in narratives.
Collaborative performance, common in other live art, is mostly absent due to technical limitations.
Preparing or improvising performances is complicated, often requiring software development.
This thesis addresses these, through a transdisciplinary integration of findings from several research areas, detailing the resulting ideas, and their implementation in a novel system:
Musical instruments are used as the primary control data source, accurately encoding all musical gestures of each performer. The advanced embodied knowledge musicians have of their instruments, allows increased expressivity, the full control data bandwidth allows high mapping complexity, while musicians‘ collaborative performance familiarity may translate to visual music performance.
The conduct of Mutable Mapping, gradually creating, destroying and altering mappings, may allow for a narrative in mapping during performance.
The art form of Soma, in which correlated auditory, visual and proprioceptive stimulus form a combined narrative, builds on knowledge that performers and audiences are more engaged in performance requiring advanced motor knowledge, and when congruent percepts across modalities coincide.
Preparing and improvising is simplified, through re-adapting the Processing programming language for artists to behave as a plug-in API, thus encapsulating complexity in modules, which may be dynamically layered during performance. Design research methodology is employed during development and evaluation, while introducing the additional viewpoint of ethnography during evaluation, engaging musicians, audience and visuals performers
The Plausibility of a String Quartet Performance in Virtual Reality
We describe an experiment that explores the contribution of auditory and other features to the illusion of plausibility in a
virtual environment that depicts the performance of a string quartet. ‘Plausibility’ refers to the component of presence that is the
illusion that the perceived events in the virtual environment are really happening. The features studied were: Gaze (the musicians
ignored the participant, the musicians sometimes looked towards and followed the participant’s movements), Sound Spatialization
(Mono, Stereo, Spatial), Auralization (no sound reflections, reflections corresponding to a room larger than the one perceived,
reflections that exactly matched the virtual room), and Environment (no sound from outside of the room, birdsong and wind
corresponding to the outside scene). We adopted the methodology based on color matching theory, where 20 participants were first
able to assess their feeling of plausibility in the environment with each of the four features at their highest setting. Then five times
participants started from a low setting on all features and were able to make transitions from one system configuration to another until
they matched their original feeling of plausibility. From these transitions a Markov transition matrix was constructed, and also
probabilities of a match conditional on feature configuration. The results show that Environment and Gaze were individually the most
important factors influencing the level of plausibility. The highest probability transitions were to improve Environment and Gaze, and
then Auralization and Spatialization. We present this work as both a contribution to the methodology of assessing presence without
questionnaires, and showing how various aspects of a musical performance can influence plausibility
Microscopic calculation of 6Li elastic and transition form factors
Variational Monte Carlo wave functions, obtained from a realistic Hamiltonian
consisting of the Argonne v18 two-nucleon and Urbana-IX three-nucleon
interactions, are used to calculate the 6Li ground-state longitudinal and
transverse form factors as well as transition form factors to the first four
excited states. The charge and current operators include one- and two-body
components, leading terms of which are constructed consistently with the
two-nucleon interaction. The calculated form factors and radiative widths are
in good agreement with available experimental data.Comment: 9 pages, 2 figures, REVTeX, submitted to Physical Review Letters,
with updated introduction and reference
Single-Brane Cosmological Solutions with a Stable Compact Extra Dimension
We consider 5-dimensional cosmological solutions of a single brane. The
correct cosmology on the brane, i.e., governed by the standard 4-dimensional
Friedmann equation, and stable compactification of the extra dimension is
guaranteed by the existence of a non-vanishing \hat{T}^5_5 which is
proportional to the 4-dimensional trace of the energy-momentum tensor. We show
that this component of the energy-momentum tensor arises from the backreaction
of the dilaton coupling to the brane. The same positive features are exhibited
in solutions found in the presence of non-vanishing cosmological constants both
on the brane (\Lambda_{br}) and in the bulk (\Lambda_B). Moreover, the
restoration of the Friedmann equation, with the correct sign, takes place for
both signs of so long as the sign of is opposite
in order to cancel the energy densities of the two cosmological
constants. We further extend our single-brane thin-wall solution to allow a
brane with finite thickness.Comment: 25 pages, Latex file, no figures, comments added, references updated,
final version to appear in Physical Review
Probing Kaluza-Klein Dark Matter with Neutrino Telescopes
In models in which all of the Standard Model fields live in extra universal
dimensions, the lightest Kaluza-Klein (KK) particle can be stable. Calculations
of the one-loop radiative corrections to the masses of the KK modes suggest
that the identity of the lightest KK particle (LKP) is mostly the first KK
excitation of the hypercharge gauge boson. This LKP is a viable dark matter
candidate with an ideal present-day relic abundance if its mass is moderately
large, between 600 to 1200 GeV. Such weakly interacting dark matter particles
are expected to become gravitationally trapped in large bodies, such as the
Sun, and annihilate into neutrinos or other particles that decay into
neutrinos. We calculate the annihilation rate, neutrino flux and the resulting
event rate in present and future neutrino telescopes. The relatively large mass
implies that the neutrino energy spectrum is expected to be well above the
energy threshold of AMANDA and IceCube. We find that the event rate in IceCube
is between a few to tens of events per year.Comment: 13 pages, 3 figures, LaTeX; typos fixed, version to appear in PR
Gamma Lines without a Continuum: Thermal Models for the Fermi-LAT 130 GeV Gamma Line
Recent claims of a line in the Fermi-LAT photon spectrum at 130 GeV are
suggestive of dark matter annihilation in the galactic center and other dark
matter-dominated regions. If the Fermi feature is indeed due to dark matter
annihilation, the best-fit line cross-section, together with the lack of any
corresponding excess in continuum photons, poses an interesting puzzle for
models of thermal dark matter: the line cross-section is too large to be
generated radiatively from open Standard Model annihilation modes, and too
small to provide efficient dark matter annihilation in the early universe. We
discuss two mechanisms to solve this puzzle and illustrate each with a simple
reference model in which the dominant dark matter annihilation channel is
photonic final states. The first mechanism we employ is resonant annihilation,
which enhances the annihilation cross-section during freezeout and allows for a
sufficiently large present-day annihilation cross section. Second, we consider
cascade annihilation, with a hierarchy between p-wave and s-wave processes.
Both mechanisms require mass near-degeneracies and predict states with masses
closely related to the dark matter mass; resonant freezeout in addition
requires new charged particles at the TeV scale.Comment: 17 pages, 8 figure
Statistical coverage for supersymmetric parameter estimation: a case study with direct detection of dark matter
Models of weak-scale supersymmetry offer viable dark matter (DM) candidates.
Their parameter spaces are however rather large and complex, such that pinning
down the actual parameter values from experimental data can depend strongly on
the employed statistical framework and scanning algorithm. In frequentist
parameter estimation, a central requirement for properly constructed confidence
intervals is that they cover true parameter values, preferably at exactly the
stated confidence level when experiments are repeated infinitely many times.
Since most widely-used scanning techniques are optimised for Bayesian
statistics, one needs to assess their abilities in providing correct confidence
intervals in terms of the statistical coverage. Here we investigate this for
the Constrained Minimal Supersymmetric Standard Model (CMSSM) when only
constrained by data from direct searches for dark matter. We construct
confidence intervals from one-dimensional profile likelihoods and study the
coverage by generating several pseudo-experiments for a few benchmark sets of
pseudo-true parameters. We use nested sampling to scan the parameter space and
evaluate the coverage for the benchmarks when either flat or logarithmic priors
are imposed on gaugino and scalar mass parameters. The sampling algorithm has
been used in the configuration usually adopted for exploration of the Bayesian
posterior. We observe both under- and over-coverage, which in some cases vary
quite dramatically when benchmarks or priors are modified. We show how most of
the variation can be explained as the impact of explicit priors as well as
sampling effects, where the latter are indirectly imposed by physicality
conditions. For comparison, we also evaluate the coverage for Bayesian credible
intervals, and observe significant under-coverage in those cases.Comment: 30 pages, 5 figures; v2 includes major updates in response to
referee's comments; extra scans and tables added, discussion expanded, typos
corrected; matches published versio
- …