420 research outputs found
Have Academic Libraries Overcome the Gender Wage Gap? An Analysis of Gender Pay Inequality
This report draws upon two data sets to examine the gender wage gap among member institutions of the Association of Research Libraries (ARL). The first data set consists of 35 years of salary survey data collected by ARL and is used to provide trend data on the gender wage gap from 1980 to 2014 as well as present an in-depth look at the wage gap in 2014. After controlling for variables such as years of experience, position, and type of library in the 2014 ARL Salary Survey data, results revealed that women on average made approximately 2 percent less than their male counterparts in 2014. The second data set comes from a survey of ARL institutions conducted by the researchers in 2015 and is used to explore the influence of additional variables on the gender wage gap that were not found in the ARL Salary Survey data. Results from both data sets suggest a substantial difference between the gender wage gap in ARL institutions and the workforce as a whole
On the application of differences in intrinsic fluctuations of Cherenkov light images for separation of air showers
The sensitivity of ground-based imaging atmospheric Cherenkov gamma-ray
observatories depends critically on the primary particle identification methods
which are used to retain photon-initiated events and suppress the spurious
background produced by cosmic rays. We suggest a new discrimination technique
which utilizes differences in the fluctuations of the light intensity in the
images of showers initiated by photons and those initiated by protons or
heavier nuclei. The database of simulated events for the proposed VERITAS
observatory has been used to evaluate the efficiency of the new technique.
Analysis has been performed for both a single VERITAS imaging telescope, and a
system of these telescopes. We demonstrate that a discrimination efficiency of
> 1.5 - 2.0 can be achieved in addition to traditional background rejection
methods based on image shape parameters.Comment: 17 pages, 9 figures, accepted for publucation in Astropart. Phy
Outsourcing and financial performance: A negative curvilinear effect
This study asks how a firm's degree of outsourcing across all activities influences financial performance. We argue there is an optimal degree of outsourcing, where firms outsource some activities yet integrate others, and that deviations lower performance in a negatively curvilinear fashion. We find empirical support, using 1995 and 1998 data on a sample of manufacturing businesses in the Netherlands, and show that the steepness of the curve increases under conditions of high uncertainty. We show the magnitude of the uncertainty effect on performance outcomes through a post hoc scenario analysis. Thus we provide a specific, theoretically and empirically grounded prediction of how outsourcing affects performance with implications for theory and practice
Very-high energy gamma-ray astronomy: A 23-year success story in high-energy astroparticle physics
Very-high energy (VHE) gamma quanta contribute only a minuscule fraction -
below one per million - to the flux of cosmic rays. Nevertheless, being neutral
particles they are currently the best "messengers" of processes from the
relativistic/ultra-relativistic Universe because they can be extrapolated back
to their origin. The window of VHE gamma rays was opened only in 1989 by the
Whipple collaboration, reporting the observation of TeV gamma rays from the
Crab nebula. After a slow start, this new field of research is now rapidly
expanding with the discovery of more than 150 VHE gamma-ray emitting sources.
Progress is intimately related with the steady improvement of detectors and
rapidly increasing computing power. We give an overview of the early attempts
before and around 1989 and the progress after the pioneering work of the
Whipple collaboration. The main focus of this article is on the development of
experimental techniques for Earth-bound gamma-ray detectors; consequently, more
emphasis is given to those experiments that made an initial breakthrough rather
than to the successors which often had and have a similar (sometimes even
higher) scientific output as the pioneering experiments. The considered energy
threshold is about 30 GeV. At lower energies, observations can presently only
be performed with balloon or satellite-borne detectors. Irrespective of the
stormy experimental progress, the success story could not have been called a
success story without a broad scientific output. Therefore we conclude this
article with a summary of the scientific rationales and main results achieved
over the last two decades.Comment: 45 pages, 38 figures, review prepared for EPJ-H special issue "Cosmic
rays, gamma rays and neutrinos: A survey of 100 years of research
TeV Gamma-ray Astronomy: A Summary
The field of TeV gamma-ray astronomy has produced many exciting results over
the last decade. Both the source catalogue, and the range of astrophysical
questions which can be addressed, continue to expand. This article presents a
topical review of the field, with a focus on the observational results of the
imaging atmospheric Cherenkov telescope arrays. The results encompass pulsars
and their nebulae, supernova remnants, gamma-ray binary systems, star forming
regions and starburst and active galaxies.Comment: 19 pages. Astroparticle Physics, in press. See published article for
higher resolution figures. Cite as: J. Holder, TeV gamma-ray astronomy: A
summary, Astropart. Phys. (2012),
http://dx.doi.org/10.1016/j.astropartphys.2012.02.01
The mother of all sudden stops: capital flows and reversals in Europe, 1919-32
New data documenting European bond issues in major financial centres from 1919 to 1932 show that conditions in international capital markets and not just in borrowing countries are important for explaining the surge and reversal in capital flows. In particular, the sharp increase in stock market volatility in the major financial centres at the end of the 1920s figured importantly in the decline in foreign lending. This article draws parallels with Europe after 200
The First VERITAS Telescope
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic
Radiation Imaging Telescope Array System) has been in operation since February
2005. We present here a technical description of the instrument and a summary
of its performance. The calibration methods are described, along with the
results of Monte Carlo simulations of the telescope and comparisons between
real and simulated data. The analysis of TeV -ray observations of the
Crab Nebula, including the reconstructed energy spectrum, is shown to give
results consistent with earlier measurements. The telescope is operating as
expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic
Bioterrorism-related inhalational anthrax: the first 10 cases reported in the United States.
From October 4 to November 2, 2001, the first 10 confirmed cases of inhalational anthrax caused by intentional release of Bacillus anthracis were identified in the United States. Epidemiologic investigation indicated that the outbreak, in the District of Columbia, Florida, New Jersey, and New York, resulted from intentional delivery of B. anthracis spores through mailed letters or packages. We describe the clinical presentation and course of these cases of bioterrorism-related inhalational anthrax. The median age of patients was 56 years (range 43 to 73 years), 70% were male, and except for one, all were known or believed to have processed, handled, or received letters containing B. anthracis spores. The median incubation period from the time of exposure to onset of symptoms, when known (n=6), was 4 days (range 4 to 6 days). Symptoms at initial presentation included fever or chills (n=10), sweats (n=7), fatigue or malaise (n=10), minimal or nonproductive cough (n=9), dyspnea (n=8), and nausea or vomiting (n=9). The median white blood cell count was 9.8 X 10(3)/mm(3) (range 7.5 to 13.3), often with increased neutrophils and band forms. Nine patients had elevated serum transaminase levels, and six were hypoxic. All 10 patients had abnormal chest X-rays; abnormalities included infiltrates (n=7), pleural effusion (n=8), and mediastinal widening (seven patients). Computed tomography of the chest was performed on eight patients, and mediastinal lymphadenopathy was present in seven. With multidrug antibiotic regimens and supportive care, survival of patients (60%) was markedly higher (<15%) than previously reported
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