1,672 research outputs found

    New York City's unemployment picture

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    This issue of Second District Highlights briefly examines several explanations that have been offered for the rise in unemployment in New York City from 1994 to 1997.Unemployment - New York (N.Y.) ; New York (N.Y.) ; Federal Reserve District, 2nd

    The Bolocam Galactic Plane Survey IX: Data Release 2 and Outer Galaxy Extension

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    We present a re-reduction and expansion of the Bolocam Galactic Plane Survey, first presented by Aguirre et al. (2011) and Rosolowsky et al. (2010). The BGPS is a 1.1 mm survey of dust emission in the Northern galactic plane, covering longitudes -10 < \ell < 90 and latitudes |b| < 0.5 with a typical 1-\sigma RMS sensitivity of 30-100 mJy in a 33" beam. Version 2 of the survey includes an additional 20 square degrees of coverage in the 3rd and 4th quadrants and 2 square degrees in the 1st quadrant. The new data release has improved angular recovery, with complete recovery out to 80" and partial recovery to 300", and reduced negative bowls around bright sources resulting from the atmospheric subtraction process. We resolve the factor of 1.5 flux calibration offset between the v1.0 data release and other data sets and determine that there is no offset between v2.0 and other data sets. The v2.0 pointing accuracy is tested against other surveys and demonstrated to be accurate and an improvement over v1.0. We present simulations and tests of the pipeline and its properties, including measurements of the pipeline's angular transfer function. The Bolocat cataloging tool was used to extract a new catalog, which includes 8594 sources, with 591 in the expanded regions. We have demonstrated that the Bolocat 40" and 80" apertures are accurate even in the presence of strong extended background emission. The number of sources is lower than in v1.0, but the amount of flux and area included in identified sources is larger.Comment: 36 pages, 16 figures, accepted to ApJS. Data available from http://irsa.ipac.caltech.edu/data/BOLOCAM_GPS

    Coherent optical phase transfer over a 32-km fiber with 1-s instability at 101710^{-17}

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    The phase coherence of an ultrastable optical frequency reference is fully maintained over actively stabilized fiber networks of lengths exceeding 30 km. For a 7-km link installed in an urban environment, the transfer instability is 6×10186 \times 10^{-18} at 1-s. The excess phase noise of 0.15 rad, integrated from 8 mHz to 25 MHz, yields a total timing jitter of 0.085 fs. A 32-km link achieves similar performance. Using frequency combs at each end of the coherent-transfer fiber link, a heterodyne beat between two independent ultrastable lasers, separated by 3.5 km and 163 THz, achieves a 1-Hz linewidth.Comment: 4 pages, 4 figure

    The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star Forming Clumps

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    We sort 46834683 molecular clouds between 10<<6510^\circ< \ell <65^\circ from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact 7070 μm\mu{\rm m} sources, mid-IR color-selected YSOs, H2O{\rm H_2O} and CH3OH{\rm CH_3OH} masers, and UCHII regions. We also present a combined NH3{\rm NH_3}-derived gas kinetic temperature and H2O{\rm H_2O} maser catalog for 17881788 clumps from our own GBT 100m observations and from the literature. We identify a subsample of 22232223 (47.5%47.5\%) starless clump candidates, the largest and most robust sample identified from a blind survey to date. Distributions of flux density, flux concentration, solid angle, kinetic temperature, column density, radius, and mass show strong (>1>1 dex) progressions when sorted by star formation indicator. The median starless clump candidate is marginally sub-virial (α0.7\alpha \sim 0.7) with >75%>75\% of clumps with known distance being gravitationally bound (α<2\alpha < 2). These samples show a statistically significant increase in the median clump mass of ΔM170370\Delta M \sim 170-370 M_\odot from the starless candidates to clumps associated with protostars. This trend could be due to (i) mass growth of the clumps at M˙200440\dot{M}\sim200-440 Msun Myr1^{-1} for an average free-fall 0.80.8 Myr time-scale, (ii) a systematic factor of two increase in dust opacity from starless to protostellar phases, (iii) and/or a variation in the ratio of starless to protostellar clump lifetime that scales as M0.4\sim M^{-0.4}. By comparing to the observed number of CH3OH{\rm CH_3OH} maser containing clumps we estimate the phase-lifetime of massive (M>103M>10^3 M_\odot) starless clumps to be 0.37±0.08 Myr (M/103 M)10.37 \pm 0.08 \ {\rm Myr} \ (M/10^3 \ {\rm M}_\odot)^{-1}; the majority (M<450M<450 M_\odot) have phase-lifetimes longer than their average free-fall time.Comment: Accepted for publication in ApJ; 33 pages; 22 figures; 7 table

    Business Volatility, Job Destruction, and Unemployment

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    Unemployment inflows fell from 4 percent of employment per month in the early 1980s to 2 percent or less by the mid 1990s and thereafter. U.S. data also show a secular decline in the job destruction rate and the volatility of firm-level employment growth rates. We interpret this decline as a decrease in the intensity of idiosyncratic labor demand shocks, a key parameter in search and matching models of unemployment. According to these models, a lower intensity of idiosyncratic shocks produces less job destruction, fewer workers flowing through the unemployment pool and less frictional unemployment. To evaluate the importance of this theoretical mechanism, we relate industry-level unemployment flows from 1977 to 2005 to industry-level indicators for the intensity of idiosyncratic shocks. Unlike previous research, we focus on the lower frequency relationship of job destruction and business volatility to unemployment flows. We find strong evidence that declines in the intensity of idiosyncratic labor demand shocks drove big declines in the incidence and rate of unemployment. This evidence implies that the unemployment rate has become much less sensitive to cyclical movements in the job-finding rate.

    The Wide Integral Field Infrared Spectrograph: Commissioning Results and On-sky Performance

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    We have recently commissioned a novel infrared (0.91.70.9-1.7 μ\mum) integral field spectrograph (IFS) called the Wide Integral Field Infrared Spectrograph (WIFIS). WIFIS is a unique instrument that offers a very large field-of-view (50^{\prime\prime} x 20^{\prime\prime}) on the 2.3-meter Bok telescope at Kitt Peak, USA for seeing-limited observations at moderate spectral resolving power. The measured spatial sampling scale is 1×1\sim1\times1^{\prime\prime} and its spectral resolving power is R2,500R\sim2,500 and 3,0003,000 in the zJzJ (0.91.350.9-1.35 μ\mum) and HshortH_{short} (1.51.71.5-1.7 μ\mum) modes, respectively. WIFIS's corresponding etendue is larger than existing near-infrared (NIR) IFSes, which are mostly designed to work with adaptive optics systems and therefore have very narrow fields. For this reason, this instrument is specifically suited for studying very extended objects in the near-infrared such as supernovae remnants, galactic star forming regions, and nearby galaxies, which are not easily accessible by other NIR IFSes. This enables scientific programs that were not originally possible, such as detailed surveys of a large number of nearby galaxies or a full accounting of nucleosynthetic yields of Milky Way supernova remnants. WIFIS is also designed to be easily adaptable to be used with larger telescopes. In this paper, we report on the overall performance characteristics of the instrument, which were measured during our commissioning runs in the second half of 2017. We present measurements of spectral resolving power, image quality, instrumental background, and overall efficiency and sensitivity of WIFIS and compare them with our design expectations. Finally, we present a few example observations that demonstrate WIFIS's full capability to carry out infrared imaging spectroscopy of extended objects, which is enabled by our custom data reduction pipeline.Comment: Published in the Proceedings of SPIE Astronomical Telescopes and Instrumentation 2018. 17 pages, 13 figure

    Foot burns: A comparative analysis of diabetic and non-diabetic patients

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    Introduction: Foot burns represent a small part of the body with many challenges. The impact of diabetes on clinical outcomes adds further issues in management that clinicians must consider in their management. These factors have serious implications on morbidity and long term sequelae. Our aim is to analyse epidemiological trends of foot burns and examine the differences between diabetic and non-diabetics at Concord hospital from 2014 to 2019. Methods: A retrospective audit from 2014–19 at Concord General Repatriation Hospital Burns Unit summarised patient demographics, burn injury, diabetic status, operations and length of stay. All foot burn injuries from 2014–19 of all ages and gender that attended Concord burns hospital were included in this study. Results: We treated 797 patients who presented with foot burns, of which 16.2% were diabetic. The average age was higher in diabetics (60.72 years) than non-diabetics (39.72 years) and more males suffered burns compared to females in both groups (p \u3c 0.001). There was a larger portion of elderly patients (greater than 65 years old, 15.1% of total) who sustained foot burns in the diabetic group compared to the non-diabetic group (p \u3c 0.001). The most affected season was summer (27.0%), but diabetic patients were 1.7 times more likely to sustain injury in winter than non-diabetics. Diabetics were 3.8 times more likely to have contact burns compared to non-diabetic patients (p \u3c 0.001). In a multivariable linear regression analysis, factors that contributed to increased length of stay included elderly status, place of event, diabetic status, number of operations, ICU admission, wound infection, amputation, and admission [F (16, 757 = 41.149, p \u3c 0.001, R2 = 0.465]. Conclusions: With the increase of diabetes, our multidisciplinary approach to diabetic foot care should include nursing, medical and surgical disciplines to identify patients at risk. The data highlights that a focus on prevention and education for diabetes is central to optimize glycaemic control and burn management, whilst providing a multidisciplinary network on discharge
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