2,606 research outputs found
Using a Kinect Interface to Develop an Interactive 3D Tabletop Display
Since the release of the motion picture ’Minority Report’ in 2002, which depicts Tom Cruise interacting with
a video display using only hand gestures, there has been a significant interest in the development of intelligent
display technology, that users are able to interact with using gestures. In the real world it is common place for us
to use gestures and body language to re-enforce our communication. It therefore becomes very natural for us to
want to interact with our virtual media in the same way.
Traditional methods for pose recognition involve using cameras to track the position of the user. However this can
be very challenging to complete acurately in a variety of environments where camera can become occluded or the
lighting conditions can change. In this research we prototyped a 3D tabletop display and explored the Kinect game
controller as a possible solution to tracking the pose and gesture of a user whilst interacting with our display
Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies
Instead of efficiently pricing greenhouse gases, policy makers have favored measures that implicitly or explicitly subsidize low carbon fuels. We simulate a transportation-sector cap & trade program (CAT) and three policies currently in use: ethanol subsidies, a renewable fuel standard (RFS), and a low carbon fuel standard (LCFS). Our simulations confirm that the alternatives to CAT are quite costly—2.5 to 4 times more expensive. We provide evidence that the persistence of these alternatives in spite of their higher costs lies in the political economy of carbon policy. The alternatives to CAT exhibit a feature that make them amenable to adoption|a right skewed distribution of gains and losses where many counties have small losses, but a smaller share of counties gain considerably—as much as $6,800 per capita, per year. We correlate our estimates of gains from CAT and the RFS with Congressional voting on the Waxman-Markey cap & trade bill, H.R. 2454. Because Waxman-Markey (WM) would weaken the RFS, House members likely viewed the two policies as competitors. Conditional on a district's CAT gains, increases in a district's RFS gains are associated with decreases in the likelihood of voting for WM. Furthermore, we show that campaign contributions are correlated with a district's gains under each policy and that these contributions are correlated with a Member's vote on WM.Institute of Transportation Studies at UC Davi
ALMA Observations of the Orion Proplyds
We present ALMA observations of protoplanetary disks ("proplyds") in the
Orion Nebula Cluster. We imaged 5 individual fields at 856um containing 22
HST-identified proplyds and detected 21 of them. Eight of those disks were
detected for the first time at submillimeter wavelengths, including the most
prominent, well-known proplyd in the entire Orion Nebula, 114-426. Thermal dust
emission in excess of any free-free component was measured in all but one of
the detected disks, and ranged between 1-163 mJy, with resulting disk masses of
0.3-79 Mjup. An additional 26 stars with no prior evidence of associated disks
in HST observations were also imaged within the 5 fields, but only 2 were
detected. The disk mass upper limits for the undetected targets, which include
OB stars, theta1Ori C and theta1Ori F, range from 0.1-0.6 Mjup. Combining these
ALMA data with previous SMA observations, we find a lack of massive (>3 Mjup)
disks in the extreme-UV dominated region of Orion, within 0.03 pc of O-star
theta1Ori C. At larger separations from theta1Ori C, in the far-UV dominated
region, there is a wide range of disk masses, similar to what is found in
low-mass star forming regions. Taken together, these results suggest that a
rapid dissipation of disk masses likely inhibits potential planet formation in
the extreme-UV dominated regions of OB associations, but leaves disks in the
far-UV dominated regions relatively unaffected.Comment: ApJ, in pres
ALMA Observations of Asymmetric Molecular Gas Emission from a Protoplanetary Disk in the Orion Nebula
We present Atacama Large Millimeter/submillimeter Array (ALMA) observations
of molecular line emission from d216-0939, one of the largest and most massive
protoplanetary disks in the Orion Nebula Cluster (ONC). We model the spectrally
resolved HCO (4--3), CO (3--2), and HCN (4--3) lines observed at 0\farcs5
resolution to fit the temperature and density structure of the disk. We also
weakly detect and spectrally resolve the CS (7--6) line but do not model it.
The abundances we derive for CO and HCO are generally consistent with
expected values from chemical modeling of protoplanetary disks, while the HCN
abundance is higher than expected. We dynamically measure the mass of the
central star to be which is inconsistent with the
previously determined spectral type of K5. We also report the detection of a
spatially unresolved high-velocity blue-shifted excess emission feature with a
measurable positional offset from the central star, consistent with a Keplerian
orbit at . Using the integrated flux of the feature in
HCO (4--3), we estimate the total H gas mass of this feature to be at
least , depending on the assumed temperature. The
feature is due to a local temperature and/or density enhancement consistent
with either a hydrodynamic vortex or the expected signature of the envelope of
a forming protoplanet within the disk.Comment: 19 pages, 12 figures, accepted for publication in A
Some Inconvenient Truths About Climate Change Policy: The Distributional Impacts of Transportation Policies
Instead of efficiently pricing greenhouse gases, policy makers have favored measures that implicitly or explicitly subsidize low carbon fuels. We simulate a transportation-sector cap & trade program (CAT) and three policies currently in use: ethanol subsidies, a renewable fuel standard (RFS), and a low carbon fuel standard (LCFS). Our simulations confirm that the alternatives to CAT are quite costly–2.5 to 4 times more expensive. We provide evidence that the persistence of these alternatives in spite of their higher costs lies in the political economy of carbon policy. The alternatives to CAT exhibit a feature that make them amenable to adoption–a right skewed distribution of gains and losses where many counties have small losses, but a smaller share of counties gain considerably–as much as $6,800 per capita, per year. We correlate our estimates of gains from CAT and the RFS with Congressional voting on the Waxman-Markey cap & trade bill, H.R. 2454. Because Waxman-Markey (WM) would weaken the RFS, House members likely viewed the two policies as competitors. Conditional on a district's CAT gains, increases in a district's RFS gains are associated with decreases in the likelihood of voting for WM. Furthermore, we show that campaign contributions are correlated with a district's gains under each policy and that these contributions are correlated with a Member's vote on WM.
Infrared Properties of High Redshift and X-ray Selected AGN Samples
The NASA/ISO Key Project on active galactic nuclei (AGN) seeks to better
understand the broad-band spectral energy distributions (SEDs) of these sources
from radio to X-rays, with particular emphasis on infrared properties. The ISO
sample includes a wide variety of AGN types and spans a large redshift range.
Two subsamples are considered herein: 8 high-redshift (1 < z < 4.7) quasars;
and 22 hard X-ray selected sources.
The X-ray selected AGN show a wide range of IR continuum shapes, extending to
cooler colors than the optical/radio sample of Elvis et al. (1994). Where a
far-IR turnover is clearly observed, the slopes are < 2.5 in all but one case
so that non-thermal emission remains a possibility. The highest redshift
quasars show extremely strong, hot IR continua requiring ~ 100 solar masses of
500 - 1000 Kelvin dust with ~ 100 times weaker optical emission. Possible
explanations for these unusual properties include: reflection of the optical
light from material above/below a torus; strong obscuration of the optical
continuum; or an intrinsic deficit of optical emission.Comment: 8 pages, 3 figures (2 color), to be published in the Springer Lecture
Notes of Physics Series as part of the proceedings for "ISO Surveys of a
Dusty Universe," a workshop held at Ringberg Castle, Germany, November 8 -
12, 1999. Requires latex style files for this series: cl2emult.cls,
cropmark.sty, lnp.sty, sprmindx.sty, subeqnar.sty (included with submission
"Kludge" gravitational waveforms for a test-body orbiting a Kerr black hole
One of the most exciting potential sources of gravitational waves for
low-frequency, space-based gravitational wave (GW) detectors such as the
proposed Laser Interferometer Space Antenna (LISA) is the inspiral of compact
objects into massive black holes in the centers of galaxies. The detection of
waves from such "extreme mass ratio inspiral" systems (EMRIs) and extraction of
information from those waves require template waveforms. The systems' extreme
mass ratio means that their waveforms can be determined accurately using black
hole perturbation theory. Such calculations are computationally very expensive.
There is a pressing need for families of approximate waveforms that may be
generated cheaply and quickly but which still capture the main features of true
waveforms. In this paper, we introduce a family of such "kludge" waveforms and
describe ways to generate them. We assess performance of the introduced
approximations by comparing "kludge" waveforms to accurate waveforms obtained
by solving the Teukolsky equation in the adiabatic limit (neglecting GW
backreaction). We find that the kludge waveforms do extremely well at
approximating the true gravitational waveform, having overlaps with the
Teukolsky waveforms of 95% or higher over most of the parameter space for which
comparisons can currently be made. Indeed, we find these kludges to be of such
high quality (despite their ease of calculation) that it is possible they may
play some role in the final search of LISA data for EMRIs.Comment: 29 pages, 11 figures, requires subeqnarray; v2 contains minor changes
for consistency with published versio
Leveraging DNA-Methylation Quantitative-Trait Loci to Characterize the Relationship between Methylomic Variation, Gene Expression, and Complex Traits
Characterizing the complex relationship between genetic, epigenetic, and transcriptomic variation has the potential to increase understanding about the mechanisms underpinning health and disease phenotypes. We undertook a comprehensive analysis of common genetic variation on DNA methylation (DNAm) by using the Illumina EPIC array to profile samples from the UK Household Longitudinal study. We identified 12,689,548 significant DNA methylation quantitative trait loci (mQTL) associations (p 60 human traits by using summary-data-based Mendelian randomization (SMR) to identify 1,662 pleiotropic associations between 36 complex traits and 1,246 DNAm sites. We also use SMR to characterize the relationship between DNAm and gene expression and thereby identify 6,798 pleiotropic associations between 5,420 DNAm sites and the transcription of 1,702 genes. Our mQTL database and SMR results are available via a searchable online database as a resource to the research community
Genetic by environmental variation but no local adaptation in oysters ( Crassostrea virginica )
Functional trait variation within and across populations can strongly influence population, community, and ecosystem processes, but the relative contributions of genetic vs. environmental factors to this variation are often not clear, potentially complicating conservation and restoration efforts. For example, local adaptation, a particular type of genetic by environmental (G*E) interaction in which the fitness of a population in its own habitat is greater than in other habitats, is often invoked in management practices, even in the absence of supporting evidence. Despite increasing attention to the potential for G*E interactions, few studies have tested multiple populations and environments simultaneously, limiting our understanding of the spatial consistency in patterns of adaptive genetic variation. In addition, few studies explicitly differentiate adaptation in response to predation from other biological and environmental factors. We conducted a reciprocal transplant experiment of first-generation eastern oyster (Crassostrea virginica) juveniles from six populations across three field sites spanning 1000 km in the southeastern Atlantic Bight in both the presence and absence of predation to test for G*E variation in this economically valuable and ecologically important species. We documented significant G*E variation in survival and growth, yet there was no evidence for local adaptation. Condition varied across oyster cohorts: Offspring of northern populations had better condition than offspring from the center of our region. Oyster populations in the southeastern Atlantic Bight differ in juvenile survival, growth, and condition, yet offspring from local broodstock do not have higher survival or growth than those from farther away. In the absence of population-specific performance information, oyster restoration and aquaculture may benefit from incorporating multiple populations into their practices
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