971 research outputs found
Is the worst over? Economic indexes and the course of the recession in New York and New Jersey
The New York-New Jersey region entered a pronounced downturn in 2008, but the pace of decline eased considerably in spring 2009 and then leveled off in July, according to three key Federal Reserve Bank of New York economic indexes. These developments, in conjunction with a growing consensus that the national economy is headed for recovery, suggest that the worst may be over for the region's economy. However, a downsizing of the area's critical finance sector could pose a major risk to the economic outlook going forward--particularly for New York City.Federal Reserve Bank of New York ; Federal Reserve District, 2nd ; Economic conditions ; Economic indicators
The Environmental Duties of Public Utilities Commissions
In addition to being economic regulators, most state utility commissions are vested with an obligation to protect the environment. The authors explore the various forms of this authority, and conclude that they preclude some commissions, but require most public utility commissions to make decisions with environmental costs in mind
Induction chemotherapy in the treatment of nasopharyngeal carcinoma: Clinical outcomes and patterns of care
Abstract The role of induction chemotherapy in nasopharyngeal carcinoma (NPC) remains controversial. The primary aim of this study was to use the National Cancer Database to evaluate the patterns of care of induction chemotherapy in NPC and its impact on overall survival (OS). Patients with NPC from 2004 to 2014 were obtained from the NCDB. Patients were considered to have received induction chemotherapy if it was started ≥43 days before the start of RT and concurrent CRT if chemotherapy started within 21 days after the start of RT. Propensity score matching was used to control for selection bias. Cox proportional hazards model was used to determine significant predictors of OS. Logistic regression model was used to determine predictors of the use of induction chemotherapy. Significance was defined as a P value <.05. A total of 4857 patients were identified: 4041 patients (87.2%) received concurrent CRT and 816 patients (16.8%) received induction chemotherapy. The use of induction therapy remained stable between 2004 and 2014. Younger patients and those with higher T‐ and N‐stage had a higher likelihood of being treated with induction chemotherapy. The 5‐year OS in patients treated with induction chemotherapy and CRT was 66.3% vs 69.1%, respectively (P = .25). There was no difference in OS when these two groups were analyzed after propensity score matching. No differences in OS existed between these treatment groups in patients with T3‐T4N1 or TanyN2‐3 disease (P = .76). Propensity score matching also did not reveal any difference in OS in patients with T3‐T4N1 or TanyN2‐3 disease. The use of induction chemotherapy has remained stable in the last decade. In this study of patients with NPC, induction chemotherapy was not associated with improved OS compared to CRT alone
Deep Optical Photometry of Six Fields in the Andromeda Galaxy
Using the Advanced Camera for Surveys on the Hubble Space Telescope, we have
obtained deep optical images reaching well below the oldest main sequence
turnoff in six fields of the Andromeda Galaxy. The fields fall at four
positions on the southeast minor axis, one position in the giant stellar
stream, and one position on the northeast major axis. These data were obtained
as part of three large observing programs designed to probe the star formation
history of the stellar population in various structures of the galaxy. In this
paper, we present the images, catalogs, and artificial star tests for these
observing programs as a supplement to the analyses published previously. These
high-level science products are also archived at the Multimission Archive at
the Space Telescope Science Institute.Comment: Accepted for publication in The Astrophysical Journal Supplement
Series. 6 pages, latex. The full set of high-level science products can be
found at http://archive.stsci.edu/prepds/andromeda
The Spectral Types of White Dwarfs in Messier 4
We present the spectra of 24 white dwarfs in the direction of the globular
cluster Messier 4 obtained with the Keck/LRIS and Gemini/GMOS spectrographs.
Determining the spectral types of the stars in this sample, we find 24 type DA
and 0 type DB (i.e., atmospheres dominated by hydrogen and helium
respectively). Assuming the ratio of DA/DB observed in the field with effective
temperature between 15,000 - 25,000 K, i.e., 4.2:1, holds for the cluster
environment, the chance of finding no DBs in our sample due simply to
statistical fluctuations is only 6 X 10^(-3). The spectral types of the ~100
white dwarfs previously identified in open clusters indicate that DB formation
is strongly suppressed in that environment. Furthermore, all the ~10 white
dwarfs previously identified in other globular clusters are exclusively type
DA. In the context of these two facts, this finding suggests that DB formation
is suppressed in the cluster environment in general. Though no satisfactory
explanation for this phenomenon exists, we discuss several possibilities.Comment: Accepted for Publication in Astrophys. J. 11 pages including 4
figures and 2 tables (journal format
Mid-Infrared Properties of Luminous Infrared Galaxies II: Probing the Dust and Gas Physics of the GOALS Sample
The Great Observatories All-Sky LIRG Survey (GOALS) is a comprehensive,
multiwavelength study of luminous infrared galaxies (LIRGs) in the local
universe. Here we present the results of a multi-component, spectral
decomposition analysis of the low resolution mid-IR Spitzer IRS spectra from
5-38um of 244 LIRG nuclei. The detailed fits and high quality spectra allow for
characterization of the individual PAH features, warm molecular hydrogen
emission, and optical depths for silicate dust grains and water ices. We find
that starbursting LIRGs, which make up the majority of GOALS, are very
consistent in their MIR properties (i.e. tau_9.7um, tau_ice, neon line and PAH
feature ratios). However, as their PAH EQW decreases, usually an indicator of
an increasingly dominant AGN, LIRGs cover a larger spread in these MIR
parameters. The contribution from PAHs to the total L(IR) in LIRGs varies from
2-29% and LIRGs prior to their first encounter show higher L(PAH)/L(IR) ratios
on average. We observe a correlation between the strength of the starburst
(IR8) and the PAH fraction at 8um but not with the 7.7 to 11.3 PAH ratio,
suggesting the fractional PDR emission, and not the overall grain properties,
is associated with the rise in IR8 for galaxies off the starburst main
sequence. We detect crystalline silicate features in 6% of the sample but only
in the most obscured sources (s_9.7um < -1.24). Ice absorption features are
observed in 11% (56%) of GOALS LIRGs (ULIRGs). Most GOALS LIRGs have
L(H2)/L(PAH) ratios elevated above those observed for normal star-forming
galaxies and exhibit a trend for increasing L(H2)/L(PAH) ratio with increasing
L(H2). While star formation appears to be the dominant process responsible for
exciting the H2 in most of the GOALS galaxies, a subset of LIRGs (10%) show
excess H2 emission that is inconsistent with PDR models and may be excited by
shocks or AGN-induced outflows.Comment: 21 pages with 20 figures plus 2 table
The White Dwarf Cooling Sequence of NGC6397
We present the results of a deep Hubble Space Telescope (HST) exposure of the
nearby globular cluster NGC6397, focussing attention on the cluster's white
dwarf cooling sequence. This sequence is shown to extend over 5 magnitudes in
depth, with an apparent cutoff at magnitude F814W=27.6. We demonstrate, using
both artificial star tests and the detectability of background galaxies at
fainter magnitudes, that the cutoff is real and represents the truncation of
the white dwarf luminosity function in this cluster. We perform a detailed
comparison between cooling models and the observed distribution of white dwarfs
in colour and magnitude, taking into account uncertainties in distance,
extinction, white dwarf mass, progenitor lifetimes, binarity and cooling model
uncertainties. After marginalising over these variables, we obtain values for
the cluster distance modulus and age of \mu_0 = 12.02 \pm 0.06 and T_c = 11.47
\pm 0.47Gyr (95% confidence limits). Our inferred distance and white dwarf
initial-final mass relations are in good agreement with other independent
determinations, and the cluster age is consistent with, but more precise than,
prior determinations made using the main sequence turnoff method. In
particular, within the context of the currently accepted \Lambda CDM
cosmological model, this age places the formation of NGC6397 at a redshift z=3,
at a time when the cosmological star formation rate was approaching its peak.Comment: 56 pages, 30 figure
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