803 research outputs found
Connection between visual arts and music: The painting and music of I-Uen Wang Hwang
This document explores the connection between the visual arts and music, particularly focusing on the similarity between visual and aural artistic expression by analyzing two sets of piano pieces composed by I-Uen Wang Hwang, a contemporary Taiwanese-American composer and artist. The piano pieces are Dream Garden, Series I and II (2000-2004) and Preludes for Piano (2016). Series I of Dream Garden contains two piano solo compositions based on a series of Hwangâs own watercolor works. Each composition has an analogous painting: âThe Horn of the Plentyâ and âButterfly Orchidâ. Series II includes two compositions written for two pianos: âRed and Whiteâ and âFireworksâ, which are also based on her watercolor paintings of flowers. âEach piano part has its own individual character with different timbres and rhythms, as if each part represented a different color or texture of the painting.â[1] Preludes for Piano is a new composition set that Hwang composed in 2016. There are three preludes, each prelude based on an abstract acrylic painting. My intention is to explore the connection between paintings and music by discussing the historical background of the two art forms, analyzing the selected music of Hwang in detail, and referring to other composers whose musical compositions were related and inspired by paintings.
[1] I-Uen Wang Hwang, âDream Gardenâ. Program notes for doctoral lecture recital. Yining Jiang. Harrisonburg: James Madison University Recital Hall, September 17, 2017
Simulating X-ray Reverberation in the UV-Emitting Regions of Active Galactic Nuclei Accretion Disks with 3D Multi-Frequency Magnetohydrodynamic Simulations
Active galactic nuclei (AGN) light curves observed with different wavebands
show that the variability in longer wavelength bands lags the variability in
shorter wavelength bands. Measuring these lags, or reverberation mapping, is
used to measure the radial temperature profile and extent of AGN disks,
typically with a reprocessing model that assumes X-rays are the main driver of
the variability in other wavelength bands. To demonstrate how this reprocessing
works with realistic accretion disk structures, we use 3D local shearing box
multi-frequency radiation magnetohydrodynamic (MHD) simulations to model the
UV-emitting region of an AGN disk, which is unstable to the magnetorotational
instability (MRI) and convection. At the same time, we inject hard X-rays
(~keV) into the simulation box to study the effects of X-ray irradiation on
the local properties of the turbulence and the resulting variability of the
emitted UV light curve. We find that disk turbulence is sufficient to drive
intrinsic variability in emitted UV light curves and that a damped random walk
(DRW) model is a good fit to this UV light curve for timescales ~days.
Meanwhile, the injected X-rays have almost no impact on the power spectrum of
the emitted UV light curve. In addition, the injected X-ray and emitted UV
light curves are only correlated if there is X-ray variability on timescales
~day, in which case we find a correlation coefficient . These
results suggest that hard X-rays with scattering dominated opacity are likely
not the main driver of the reverberation signals.Comment: 9 pages, 3 figures, submitted to ApJ
Dissecting the biological relationship between TCGA miRNA and mRNA sequencing data using MMiRNA-Viewer
Abstract
Background
MicroRNAs (miRNA) are short nucleotides that interact with their target genes through 3âČ untranslated regions (UTRs). The Cancer Genome Atlas (TCGA) harbors an increasing amount of cancer genome data for both tumor and normal samples. However, there are few visualization tools focusing on concurrently displaying important relationships and attributes between miRNAs and mRNAs of both cancer tumor and normal samples. Moreover, a deep investigation of miRNA-mRNA target and biological relationships across multiple cancer types by integrating web-based analysis has not been thoroughly conducted.
Results
We developed an interactive visualization tool called MMiRNA-Viewer that can concurrently present the co-relationships of expression between miRNA-mRNA pairs of both tumor and normal samples into a single graph. The input file of MMiRNA-Viewer contains the expression information including fold changes between normal and tumor samples for mRNAs and miRNAs, the correlation between mRNA and miRNA, and the predicted target relationship by a number of databases. Users can also load their own input data into MMiRNA-Viewer and visualize and compare detailed information about cancer-related gene expression changes, and also changes in the expression of transcription-regulating miRNAs.
To validate the MMiRNA-Viewer, eight types of TCGA cancer datasets with both normal and control samples were selected in this study and three filter steps were applied subsequently. We performed Gene Ontology (GO) analysis for genes available in final selected 238 pairs and also for genes in the top 5Â % (95 percentile) for each of eight cancer types to report a significant number of genes involved in various biological functions and pathways. We also calculated various centrality measurement matrices for the largest connected component(s) in each of eight cancers and reported top genes and miRNAs with high centrality measurements.
Conclusions
With its user-friendly interface, dynamic visualization and advanced queries, we also believe MMiRNA-Viewer offers an intuitive approach for visualizing and elucidating co-relationships between miRNAs and mRNAs of both tumor and normal samples. We suggest that miRNA and mRNA pairs with opposite fold changes of their expression and with inverted correlation values between tumor and normal samples might be most relevant for explaining the decoupling of mRNAs and their targeting miRNAs in tumor samples for certain cancer types.http://deepblue.lib.umich.edu/bitstream/2027.42/134658/1/12859_2016_Article_1219.pd
A Negative Long Lag from the Optical to the UV Continuum in Fairall 9
We report the detection of a long-timescale negative lag, where the blue
bands lag the red bands, in the nearby Seyfert 1 galaxy Fairall 9. Active
Galactic Nuclei (AGN) light curves show variability over a wide range of
timescales. By measuring time lags between different wavelengths, the otherwise
inaccessible structure and kinematics of the accretion disk can be studied. One
common approach, reverberation mapping, quantifies the continuum and line lags
moving outwards through the disk at the light-travel time, revealing the size
and temperature profile of the disk. Inspired by numerical simulations, we
expect longer lags to exist in AGN light curves that travel inward on longer
timescales, tracing the accretion process itself. By analyzing AGN light curves
in both temporal and frequency space, we report the detection of long-timescale
lags ( days) in Fairall 9 which propagate in the opposite direction
to the reverberation lag. The short continuum lag ( days) is also detected
and is consistent with reverberation lags reported in the literature. When
fitting the longer lag as a function of frequency with a model motivated by the
thin disk model, we find that the disk scale height likely increases outward in
the disk. This detection raises the exciting prospect of mapping accretion disk
structures across a wide range of AGN parameters.Comment: 24 pages, 14 figures, submitted to Ap
Negative Lags on the Viscous Timescale in Quasar Photometry and Prospects for Detecting More with LSST
The variability of quasar light curves can be used to study the structure of
quasar accretion disks. For example, continuum reverberation mapping uses
delays between variability in short and long wavelength bands ("short" lags) to
measure the radial extent and temperature profile of the disk. Recently, a
potential reverse lag, where variations in shorter wavelength bands lag the
longer wavelength bands at the much longer viscous timescale, was detected for
Fairall 9. Inspired by this detection, we derive a timescale for these "long"
negative lags from fluctuation propagation models and recent simulations. We
use this timescale to forecast our ability to detect long lags using the Vera
Rubin Legacy Survey of Space and Time (LSST). After exploring several methods,
including the interpolated cross-correlation function, a Von-Neumann estimator,
javelin, and a maximum-likelihood Fourier method, we find that our two main
methods, javelin and the maximum-likelihood method, can together detect long
lags of up to several hundred days in mock LSST light curves. Our methods work
best on proposed LSST cadences with long season lengths, but can also work for
the current baseline LSST cadence, especially if we add observations from other
optical telescopes during seasonal gaps. We find that LSST has the potential to
detect dozens to hundreds of additional long lags. Detecting these long lags
can teach us about the vertical structure of quasar disks and how it scales
with different quasar properties.Comment: 40 pages, 36 figures, submitted to Ap
ELVES III: Environmental Quenching by Milky Way-Mass Hosts
Isolated dwarf galaxies usually exhibit robust star formation but satellite
dwarf galaxies are often devoid of young stars, even in Milky Way-mass groups.
Dwarf galaxies thus offer an important laboratory of the environmental
processes that cease star formation. We explore the balance of quiescent and
star-forming galaxies (quenched fractions) for a sample of ~400 satellite
galaxies around 30 Local Volume hosts from the Exploration of Local VolumE
Satellites (ELVES) Survey. We present quenched fractions as a function of
satellite stellar mass, projected radius, and host halo mass, to conclude that
overall, the quenched fractions are similar to the Milky Way, dropping below
50% at satellite M* ~ 10^8 M_sun. We may see hints that quenching is less
efficient at larger radius. Through comparison with the semi-analytic modeling
code satgen, we are also able to infer average quenching times as a function of
satellite mass in host halo-mass bins. There is a gradual increase in quenching
time with satellite stellar mass rather than the abrupt change from rapid to
slow quenching that has been inferred for the Milky Way. We also generally
infer longer average quenching times than recent hydrodynamical simulations.
Our results are consistent with models that suggest a wide range of quenching
times are possible via ram-pressure stripping, depending on the clumpiness of
the circumgalactic medium, the orbits of the satellites, and the degree of
earlier preprocessing.Comment: 18 pages, 12 figures, replaced post-refereeing, no major change
- âŠ