5,132 research outputs found
Recommended from our members
Remembering the future: An overview of co-evolution in musical improvisation
Musical improvisation is driven mainly by the unconscious mind, engaging the dialogic imagination to reference the entire cultural heritage of an improvisor in a single flash. This paper introduces a case study of evolutionary computation techniques, in particular genetic co-evolution, as applied to the frequency domain using MPEG7 techniques, in order to create an artificial agent that mediates between an improvisor and her unconscious mind, to probe and unblock improvisatory action in live music performance or practice
The role of automaticity and attention in neural processes underlying empathy for happiness, sadness, and anxiety.
Although many studies have examined the neural basis of empathy, relatively little is known about how empathic processes are affected by different attentional conditions. Thus, we examined whether instructions to empathize might amplify responses in empathy-related regions and whether cognitive load would diminish the involvement of these regions. Thirty-two participants completed a functional magnetic resonance imaging session assessing empathic responses to individuals experiencing happy, sad, and anxious events. Stimuli were presented under three conditions: watching naturally, actively empathizing, and under cognitive load. Across analyses, we found evidence for a core set of neural regions that support empathic processes (dorsomedial prefrontal cortex, DMPFC; medial prefrontal cortex, MPFC; temporoparietal junction, TPJ; amygdala; ventral anterior insula, AI; and septal area, SA). Two key regions-the ventral AI and SA-were consistently active across all attentional conditions, suggesting that they are automatically engaged during empathy. In addition, watching vs. empathizing with targets was not markedly different and instead led to similar subjective and neural responses to others' emotional experiences. In contrast, cognitive load reduced the subjective experience of empathy and diminished neural responses in several regions related to empathy and social cognition (DMPFC, MPFC, TPJ, and amygdala). The results reveal how attention impacts empathic processes and provides insight into how empathy may unfold in everyday interactions
An Analysis and Performance Guide to the Trumpet Works of Peter Lawrence
This study is an analysis and guide to the performance of the trumpet solo works of Peter Lawrence. The following compositions will be examined: Dialogue von Mendez mit Liebe for two trumpet soloists doubling on cornet and wind ensemble (2001); Concerto for Trumpet Doubling Flugelhorn and Orchestra (2005); and Concertino for Two Trumpets, Strings, and Rhythm Section (2005). The composition and premiere history of each piece will be discussed. Each piece will be analyzed for characteristic harmonic, melodic, rhythmic, and orchestration elements. Each piece will also be discussed from a performer\u27s perspective ,with recommendations for practice, difficulty analysis, and suggestions for performance. As much as is possible, input from the composer has been included. The dissertation concludes with a list of Peter Lawrence\u27s compositions. It is hoped that this study will bring these pieces, as yet unperformed in the United States, to the attention of trumpet performers; and help anyone interested in learning or studying these works
Mitochondrial DNA lineages of Italian Giara and Sarcidano horses
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed
Measuring spike train synchrony
Estimating the degree of synchrony or reliability between two or more spike
trains is a frequent task in both experimental and computational neuroscience.
In recent years, many different methods have been proposed that typically
compare the timing of spikes on a certain time scale to be fixed beforehand.
Here, we propose the ISI-distance, a simple complementary approach that
extracts information from the interspike intervals by evaluating the ratio of
the instantaneous frequencies. The method is parameter free, time scale
independent and easy to visualize as illustrated by an application to real
neuronal spike trains obtained in vitro from rat slices. In a comparison with
existing approaches on spike trains extracted from a simulated Hindemarsh-Rose
network, the ISI-distance performs as well as the best time-scale-optimized
measure based on spike timing.Comment: 11 pages, 13 figures; v2: minor modifications; v3: minor
modifications, added link to webpage that includes the Matlab Source Code for
the method (http://inls.ucsd.edu/~kreuz/Source-Code/Spike-Sync.html
Reaction Brownian Dynamics and the effect of spatial fluctuations on the gain of a push-pull network
Brownian Dynamics algorithms are widely used for simulating soft-matter and
biochemical systems. In recent times, their application has been extended to
the simulation of coarse-grained models of cellular networks in simple
organisms. In these models, components move by diffusion, and can react with
one another upon contact. However, when reactions are incorporated into a
Brownian Dynamics algorithm, attention must be paid to avoid violations of the
detailed-balance rule, and therefore introducing systematic errors in the
simulation. We present a Brownian Dynamics algorithm for reaction-diffusion
systems that rigorously obeys detailed balance for equilibrium reactions. By
comparing the simulation results to exact analytical results for a bimolecular
reaction, we show that the algorithm correctly reproduces both equilibrium and
dynamical quantities. We apply our scheme to a ``push-pull'' network in which
two antagonistic enzymes covalently modify a substrate. Our results highlight
that the diffusive behaviour of the reacting species can reduce the gain of the
response curve of this network.Comment: 25 pages, 7 figures, submitted to Journal of Chemical Physic
Statistical Dynamics of Religions and Adherents
Religiosity is one of the most important sociological aspects of populations.
All religions may evolve in their beliefs and adapt to the society
developments. A religion is a social variable, like a language or wealth, to be
studied like any other organizational parameter.
Several questions can be raised, as considered in this study: e.g. (i) from a
``macroscopic'' point of view : How many religions exist at a given time? (ii)
from a ``microscopic'' view point: How many adherents belong to one religion?
Does the number of adherents increase or not, and how? No need to say that if
quantitative answers and mathematical laws are found, agent based models can be
imagined to describe such non-equilibrium processes.
It is found that empirical laws can be deduced and related to preferential
attachment processes, like on evolving network; we propose two different
algorithmic models reproducing as well the data. Moreover, a population
growth-death equation is shown to be a plausible modeling of evolution dynamics
in a continuous time framework. Differences with language dynamic competition
is emphasized.Comment: submitted to EP
The Infrared Telescope Facility (IRTF) spectral library: spectral diagnostics for cool stars
The near-infrared (NIR) wavelength range offers some unique spectral
features, and it is less prone to the extinction than the optical one.
Recently, the first flux calibrated NIR library of cool stars from the NASA
Infrared Telescope Facility (IRTF) have become available, and it has not been
fully exploited yet. We want to develop spectroscopic diagnostics for stellar
physical parameters based on features in the wavelength range 1-5 micron. In
this work we test the technique in the I and K bands. The study of the Y, J, H,
and L bands will be presented in the following paper. An objective method for
semi-empirical definition of spectral features sensitive to various physical
parameters is applied to the spectra. It is based on sensitivity map--i.e.,
derivative of the flux in the spectra with respect to the stellar parameters at
a fixed wavelength. New optimized indices are defined and their equivalent
widths (EWs) are measured. A number of sensitive features to the effective
temperature and surface gravity are re-identified or newly identified clearly
showing the reliability of the sensitivity map analysis. The sensitivity map
allows to identify the best bandpass limits for the line and nearby continuum.
It reliably predicts the trends of spectral features with respect to a given
physical parameter but not their absolute strengths. Line blends are easy to
recognize when blended features have different behavior with respect to some
physical stellar parameter. The use of sensitivity map is therefore
complementary to the use of indices. We give the EWs of the new indices
measured for the IRTF star sample. This new and homogeneous set of EWs will be
useful for stellar population synthesis models and can be used to get
element-by-element abundances for unresolved stellar population studies in
galaxies.Comment: 46 pages, 27 figures, accepted for publication on Astronomy and
Astrophysic
- âŠ