3,109 research outputs found
Uniform Rectifiability and Harmonic Measure III: Riesz transform bounds imply uniform rectifiability of boundaries of 1-sided NTA domains
Let , , be a closed, Ahlfors-David regular
set of dimension satisfying the "Riesz Transform bound"
Assume further that is the boundary of a domain
satisfying the Harnack Chain condition plus an
interior (but not exterior) Corkscrew condition. Then is uniformly
rectifiable
The Comparison of the Swift Gamma-Ray Bursts With and Without Measured Redshifts
Gamma-ray bursts, detected by the Swift satellite, are separated into two
samples: the bursts with and without determined redshifts. These two samples
are compared by the standard Student t-test and F-test. We have compared the
dispersions and the mean values of the durations, peak fluxes and fluences in
order to find any differences among these two samples. No essential differences
were found.Comment: Published in the Proceedings of the 4th Heidelberg International
Symposium on High Energy Gamma-Ray Astronomy, 200
Chance, long tails, and inference: a non-Gaussian, Bayesian theory of vocal learning in songbirds
Traditional theories of sensorimotor learning posit that animals use sensory
error signals to find the optimal motor command in the face of Gaussian sensory
and motor noise. However, most such theories cannot explain common behavioral
observations, for example that smaller sensory errors are more readily
corrected than larger errors and that large abrupt (but not gradually
introduced) errors lead to weak learning. Here we propose a new theory of
sensorimotor learning that explains these observations. The theory posits that
the animal learns an entire probability distribution of motor commands rather
than trying to arrive at a single optimal command, and that learning arises via
Bayesian inference when new sensory information becomes available. We test this
theory using data from a songbird, the Bengalese finch, that is adapting the
pitch (fundamental frequency) of its song following perturbations of auditory
feedback using miniature headphones. We observe the distribution of the sung
pitches to have long, non-Gaussian tails, which, within our theory, explains
the observed dynamics of learning. Further, the theory makes surprising
predictions about the dynamics of the shape of the pitch distribution, which we
confirm experimentally
On the Intermediate Subgroup of the Gamma-Ray Bursts in the Swift Database
A sample of 286 gamma-ray bursts, detected by Swift satellite, is studied
statistically by the chi^2 test and the Student t-test, respectively. The short
and long subgroups are well detected in the Swift data. But no intermediate
subgroup is seen. The non-detection of this subgroup in the Swift database can
be explained, once it is assumed that in the BATSE database the short and the
intermediate subgroups form a common subclass.Comment: Published in 4th Heidelberg International Symposium on High Energy
Gamma-Ray Astronomy, 200
The conditional process model of mindfulness and emotion regulation: An empirical test
BACKGROUND: The conditional process model (CPM) of mindfulness and emotion regulation posits that specific mediators and moderators link these constructs to mental health outcomes. The current study empirically examined the central tenets of the CPM, which posit that nonreactivity moderates the indirect effect of observation on symptoms of emotional disorders through cognitive emotion regulation strategies. METHODS: A clinical sample (n=1667) of individuals from Japan completed a battery of self-report instruments. Several path analyses were conducted to determine whether cognitive emotion regulation strategies mediate the relationship between observation and symptoms of individual emotional disorders, and to determine whether nonreactivity moderated these indirect effects. RESULTS: Results provided support the CPM. Specifically, nonreactivity moderated the indirect effect of observation on symptoms through reappraisal, but it did not moderate the indirect effect of observation on symptoms through suppression. LIMITATIONS: Causal interpretations are limited, and cultural considerations must be acknowledged given the Japanese sample CONCLUSIONS: These results underscore the potential importance of nonreactivity and emotion regulation as targets for interventions.R01 AT007257 - NCCIH NIH HHS; R34 MH099311 - NIMH NIH HH
Cavity-enhanced Raman Microscopy of Individual Carbon Nanotubes
Raman spectroscopy reveals chemically specific information and provides
label-free insight into the molecular world. However, the signals are
intrinsically weak and call for enhancement techniques. Here, we demonstrate
Purcell enhancement of Raman scattering in a tunable high-finesse microcavity,
and utilize it for molecular diagnostics by combined Raman and absorption
imaging. Studying individual single-wall carbon nanotubes, we identify crucial
structural parameters such as nanotube radius, electronic structure and
extinction cross-section. We observe a 320-times enhanced Raman scattering
spectral density and an effective Purcell factor of 6.2, together with a
collection efficiency of 60%. Potential for significantly higher enhancement,
quantitative signals, inherent spectral filtering and absence of intrinsic
background in cavity-vacuum stimulated Raman scattering render the technique a
promising tool for molecular imaging. Furthermore, cavity-enhanced Raman
transitions involving localized excitons could potentially be used for gaining
quantum control over nanomechanical motion and open a route for molecular
cavity optomechanics
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