850 research outputs found
Tobacco angina : An electrocardiographic study
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32562/1/0000688.pd
Morally Respectful Listening and its Epistemic Consequences
What does it mean to listen to someone respectfully, that is, insofar as they are due recognition respect? This paper addresses that question and gives the following answer: it is to listen in such a way that you are open to being surprised. A specific interpretation of this openness to surprise is then defended
CfAIR2: Near Infrared Light Curves of 94 Type Ia Supernovae
CfAIR2 is a large homogeneously reduced set of near-infrared (NIR) light
curves for Type Ia supernovae (SN Ia) obtained with the 1.3m Peters Automated
InfraRed Imaging TELescope (PAIRITEL). This data set includes 4607 measurements
of 94 SN Ia and 4 additional SN Iax observed from 2005-2011 at the Fred
Lawrence Whipple Observatory on Mount Hopkins, Arizona. CfAIR2 includes JHKs
photometric measurements for 88 normal and 6 spectroscopically peculiar SN Ia
in the nearby universe, with a median redshift of z~0.021 for the normal SN Ia.
CfAIR2 data span the range from -13 days to +127 days from B-band maximum. More
than half of the light curves begin before the time of maximum and the coverage
typically contains ~13-18 epochs of observation, depending on the filter. We
present extensive tests that verify the fidelity of the CfAIR2 data pipeline,
including comparison to the excellent data of the Carnegie Supernova Project.
CfAIR2 contributes to a firm local anchor for supernova cosmology studies in
the NIR. Because SN Ia are more nearly standard candles in the NIR and are less
vulnerable to the vexing problems of extinction by dust, CfAIR2 will help the
supernova cosmology community develop more precise and accurate extragalactic
distance probes to improve our knowledge of cosmological parameters, including
dark energy and its potential time variation.Comment: 31 pages, 15 figures, 10 tables. Accepted to ApJS. v2 modified to
more closely match journal versio
Enhanced Interleukin (IL)-13 Responses in Mice Lacking IL-13 Receptor α 2
Interleukin (IL)-13 has recently been shown to play important and unique roles in asthma, parasite immunity, and tumor recurrence. At least two distinct receptor components, IL-4 receptor (R)α and IL-13Rα1, mediate the diverse actions of IL-13. We have recently described an additional high affinity receptor for IL-13, IL-13Rα2, whose function in IL-13 signaling is unknown. To better appreciate the functional importance of IL-13Rα2, mice deficient in IL-13Rα2 were generated by gene targeting. Serum immunoglobulin E levels were increased in IL-13Rα2−/− mice despite the fact that serum IL-13 was absent and immune interferon γ production increased compared with wild-type mice. IL-13Rα2–deficient mice display increased bone marrow macrophage progenitor frequency and decreased tissue macrophage nitric oxide and IL-12 production in response to lipopolysaccharide. These results are consistent with a phenotype of enhanced IL-13 responsiveness and demonstrate a role for endogenous IL-13 and IL-13Rα2 in regulating immune responses in wild-type mice
Cosmological Constraints from Measurements of Type Ia Supernovae discovered during the first 1.5 years of the Pan-STARRS1 Survey
We present griz light curves of 146 spectroscopically confirmed Type Ia
Supernovae () discovered during the first 1.5 years of the
Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is
determined by a combination of on-site measurements of the instrument response
function and observations of spectrophotometric standard stars. We find that
the systematic uncertainties in the photometric system are currently 1.2\%
without accounting for the uncertainty in the HST Calspec definition of the AB
system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia
that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113
PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only SNe and
assuming a constant dark energy equation of state and flatness, yields
.
When combined with BAO+CMB(Planck)+, the analysis yields and including all
identified systematics (see also Scolnic et al. 2014). The value of is
inconsistent with the cosmological constant value of at the 2.3
level. Tension endures after removing either the BAO or the constraint,
though it is strongest when including the constraint. If we include WMAP9
CMB constraints instead of those from Planck, we find
, which diminishes the discord to . We
cannot conclude whether the tension with flat CDM is a feature of dark
energy, new physics, or a combination of chance and systematic errors. The full
Pan-STARRS1 supernova sample with 3 times as many SNe should provide
more conclusive results.Comment: 38 pages, 16 figures, 14 tables, ApJ in pres
An ultraviolet-optical flare from the tidal disruption of a helium-rich stellar core
The flare of radiation from the tidal disruption and accretion of a star can
be used as a marker for supermassive black holes that otherwise lie dormant and
undetected in the centres of distant galaxies. Previous candidate flares have
had declining light curves in good agreement with expectations, but with poor
constraints on the time of disruption and the type of star disrupted, because
the rising emission was not observed. Recently, two `relativistic' candidate
tidal disruption events were discovered, each of whose extreme X-ray luminosity
and synchrotron radio emission were interpreted as the onset of emission from a
relativistic jet. Here we report the discovery of a luminous
ultraviolet-optical flare from the nuclear region of an inactive galaxy at a
redshift of 0.1696. The observed continuum is cooler than expected for a simple
accreting debris disk, but the well-sampled rise and decline of its light curve
follows the predicted mass accretion rate, and can be modelled to determine the
time of disruption to an accuracy of two days. The black hole has a mass of
about 2 million solar masses, modulo a factor dependent on the mass and radius
of the star disrupted. On the basis of the spectroscopic signature of ionized
helium from the unbound debris, we determine that the disrupted star was a
helium-rich stellar core.Comment: To appear in Nature on May 10, 201
Systematic Uncertainties Associated with the Cosmological Analysis of the First Pan-STARRS1 Type Ia Supernova Sample
We probe the systematic uncertainties from 113 Type Ia supernovae (SNIa) in
the Pan-STARRS1 (PS1) sample along with 197 SN Ia from a combination of
low-redshift surveys. The companion paper by Rest et al. (2013) describes the
photometric measurements and cosmological inferences from the PS1 sample. The
largest systematic uncertainty stems from the photometric calibration of the
PS1 and low-z samples. We increase the sample of observed Calspec standards
from 7 to 10 used to define the PS1 calibration system. The PS1 and SDSS-II
calibration systems are compared and discrepancies up to ~0.02 mag are
recovered. We find uncertainties in the proper way to treat intrinsic colors
and reddening produce differences in the recovered value of w up to 3%. We
estimate masses of host galaxies of PS1 supernovae and detect an insignificant
difference in distance residuals of the full sample of 0.037\pm0.031 mag for
host galaxies with high and low masses. Assuming flatness in our analysis of
only SNe measurements, we find . With additional constraints from BAO,
CMB(Planck) and H0 measurements, we find and
(statistical and systematic errors added in
quadrature). Significance of the inconsistency with depends on whether
we use Planck or WMAP measurements of the CMB:
.Comment: 24 pages, 20 figures. Accepted by Ap
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Individual common variants exert weak effects on the risk for autism spectrum disorders.
While it is apparent that rare variation can play an important role in the genetic architecture of autism spectrum disorders (ASDs), the contribution of common variation to the risk of developing ASD is less clear. To produce a more comprehensive picture, we report Stage 2 of the Autism Genome Project genome-wide association study, adding 1301 ASD families and bringing the total to 2705 families analysed (Stages 1 and 2). In addition to evaluating the association of individual single nucleotide polymorphisms (SNPs), we also sought evidence that common variants, en masse, might affect the risk. Despite genotyping over a million SNPs covering the genome, no single SNP shows significant association with ASD or selected phenotypes at a genome-wide level. The SNP that achieves the smallest P-value from secondary analyses is rs1718101. It falls in CNTNAP2, a gene previously implicated in susceptibility for ASD. This SNP also shows modest association with age of word/phrase acquisition in ASD subjects, of interest because features of language development are also associated with other variation in CNTNAP2. In contrast, allele scores derived from the transmission of common alleles to Stage 1 cases significantly predict case status in the independent Stage 2 sample. Despite being significant, the variance explained by these allele scores was small (Vm< 1%). Based on results from individual SNPs and their en masse effect on risk, as inferred from the allele score results, it is reasonable to conclude that common variants affect the risk for ASD but their individual effects are modest
Very Early Ultraviolet and Optical Observations of the Type Ia Supernova 2009ig
Supernova (SN) 2009ig was discovered 17 hours after explosion by the Lick
Observatory Supernova Search, promptly classified as a normal Type Ia SN (SN
Ia), peaked at V = 13.5 mag, and was equatorial, making it one of the foremost
supernovae for intensive study in the last decade. Here, we present ultraviolet
(UV) and optical observations of SN 2009ig, starting about 1 day after
explosion until around maximum brightness. Our data include excellent UV and
optical light curves, 25 premaximum optical spectra, and 8 UV spectra,
including the earliest UV spectrum ever obtained of a SN Ia. SN 2009ig is a
relatively normal SN Ia, but does display high-velocity ejecta - the ejecta
velocity measured in our earliest spectra (v ~ -23,000 km/s for Si II 6355) is
the highest yet measured in a SN Ia. The spectral evolution is very dramatic at
times earlier than 12 days before maximum brightness, but slows after that
time. The early-time data provide a precise measurement of 17.13 +/- 0.07 days
for the SN rise time. The optical color curves and early-time spectra are
significantly different from template light curves and spectra used for
light-curve fitting and K-corrections, indicating that the template light
curves and spectra do not properly represent all Type Ia supernovae at very
early times. In the age of wide-angle sky surveys, SNe like SN 2009ig that are
nearby, bright, well positioned, and promptly discovered will still be rare. As
shown with SN 2009ig, detailed studies of single events can provide
significantly more information for testing systematic uncertainties related to
SN Ia distance estimates and constraining progenitor and explosion models than
large samples of more distant SNe.Comment: 16 pages, 14 figures, ApJ, in pres
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