2,519 research outputs found
Thoughts on the Unification of U.S. Labor and Employment Law: Is the Whole Greater than the Sum of the Parts
As the need for fundamental reform of our nation\u27s labor laws has grown more and more evident since the 1970s, major reform efforts have focused narrowly on adjusting the provisions of the National Labor Relations Act (NLRA), but have repeatedly foundered amidst intense polarization over tipping the existing balance between labor and management.\u27 At the same time, at the federal, state, and, increasingly, municipal levels, U.S. labor laws governing worker organization and collective bargaining have been surrounded by a growing thicket of other laws governing the workplace
Different Faces in the Crowd: A Happiness Superiority Effect for Schematic Faces in Heterogeneous Backgrounds
Recently, D.V. Becker, Anderson, Mortensen, Neufeld, and Neel (2011) proposed recommendations to avoid methodological confounds in visual search studies using emotional photographic faces. These confounds were argued to cause the frequently observed Anger Superiority Effect (ASE), the faster detection of angry than happy expressions, and conceal a true Happiness Superiority Effect (HSE). In Experiment 1, we applied these recommendations (for the first time) to visual search among schematic faces that previously had consistently yielded a robust ASE. Contrary to the prevailing literature, but consistent with D.V. Becker et al. (2011), we observed a HSE with schematic faces. The HSE with schematic faces was replicated in Experiments 2 and 3 using a similar method in discrimination tasks rather than fixed target searches. Experiment 4 isolated background heterogeneity as the key determinant leading to the HSE
Chandra X-Ray Observations of Nineteen Millisecond Pulsars in the Globular Cluster 47 Tucanae
We present spectral and long-timescale variability analyses of
\textit{Chandra} ACIS-S observations of the 19 millisecond pulsars (MSPs) with
precisely known positions in the globular cluster 47 Tucanae. The X-ray
emission of the majority of these MSPs is well described by a thermal
(blackbody or neutron star hydrogen atmosphere) spectrum with a temperature
K, emission radius km,
and luminosity ergs s. For several MSPs, there is
indication that a second thermal component is required, similar to what is seen
in some nearby field MSPs. The radio-eclipsing binary MSPs 47 Tuc J, O, and W
show a significant non-thermal component, with photon index ,
which may originate in an shock formed due to interaction between the
relativistic pulsar wind and matter from the stellar companion. We re-examine
the X-ray--spindown luminosity relation () and find that due to
the large uncertainties in both parameters the result is consistent with both
the linear relation and the flatter
predicted by polar cap heating models. In terms of X-ray properties, we find no
clear systematic differences between MSPs in globular clusters and in the field
of the Galaxy.Comment: 13 pages, 6 figures, accepted for publication in the Astrophysical
Journa
Constraints on the Universal CIV Mass Density at z~6 from Early IR Spectra Obtained with the Magellan FIRE Spectrograph
We present a new determination of the intergalactic CIV mass density at 4.3 <
z < 6.3. Our constraints are derived from high signal-to-noise spectra of seven
quasars at z > 5.8 obtained with the newly commissioned FIRE spectrograph on
the Magellan Baade telescope, coupled with six observations of northern objects
taken from the literature. We confirm the presence of a downturn in the CIV
abundance at =5.66 by a factor of 4.1 relative to its value at =4.96, as
measured in the same sightlines. In the FIRE sample, a strong system previously
reported in the literature as CIV at z=5.82 is re-identified as MgII at z=2.78,
leading to a substantial downward revision in for these prior
studies. Additionally we confirm the presence of at least two systems with
low-ionization CII, SiII, and OI absorption but relatively weak signal from
CIV. The latter systems systems may be of interest if the downward trend in
at high redshift is driven in part by ionization effects.Comment: 14 pages, 6 figures, 2 tables. Submitted to Ap
Chandra X-ray Observations of 12 Millisecond Pulsars in the Globular Cluster M28
We present a Chandra X-ray Observatory investigation of the millisecond
pulsars (MSPs) in the globular cluster M28 (NGC 6626). In what is one of the
deepest X-ray observations of a globular cluster, we firmly detect seven and
possibly detect two of the twelve known M28 pulsars. With the exception of PSRs
B1821-24 and J1824-2452H, the detected pulsars have relatively soft spectra,
with X-ray luminosities 10^30-31 ergs s^-1 (0.3-8 keV),similar to most
"recycled" pulsars in 47 Tucanae and the field of the Galaxy, implying thermal
emission from the pulsar magnetic polar caps. We present the most detailed
X-ray spectrum to date of the energetic PSR B1821-24. It is well described by a
purely non-thermal spectrum with spectral photon index 1.23 and luminosity
1.4x10^33Theta(D/5.5 kpc)^2 ergs s^-1 (0.3-8 keV), where Theta is the fraction
of the sky covered by the X-ray emission beam(s). We find no evidence for the
previously reported line emission feature around 3.3 keV, most likely as a
consequence of improvements in instrument calibration. The X-ray spectrum and
pulse profile of PSR B1821--24 suggest that the bulk of unpulsed emission from
this pulsar is not of thermal origin, and is likely due to low-level
non-thermal magnetospheric radiation, an unresolved pulsar wind nebula, and/or
small-angle scattering of the pulsed X-rays by interstellar dust grains. The
peculiar binary PSR J1824-2452H shows a relatively hard X-ray spectrum and
possible variability at the binary period, indicative of an intrabinary shock
formed by interaction between the relativistic pulsar wind and matter from its
non-degenerate companion star.Comment: 9 pages, 6 figures. Accepted for publication in the Astophysical
Journa
Orbitofrontal cortex mediates pain inhibition by monetary reward
Pleasurable stimuli, including reward, inhibit pain, but the level of the neuraxis at which they do so and the cerebral
processes involved are unknown. Here, we characterized a brain circuitry mediating pain inhibition by reward. Twenty-four
healthy participants underwent functional magnetic resonance imaging while playing a wheel of fortune game with simultaneous thermal pain stimuli and monetary wins or losses. As expected, winning decreased pain perception compared to
losing. Inter-individual differences in pain modulation by monetary wins relative to losses correlated with activation in the
medial orbitofrontal cortex (mOFC). When pain and reward occured simultaneously, mOFCs functional connectivity
changed: the signal time course in the mOFC condition-dependent correlated negatively with the signal time courses in the
rostral anterior insula, anterior-dorsal cingulate cortex and primary somatosensory cortex, which might signify momentto-moment down-regulation of these regions by the mOFC. Monetary wins and losses did not change the magnitude of
pain-related activation, including in regions that code perceived pain intensity when nociceptive input varies and/or receive
direct nociceptive input. Pain inhibition by reward appears to involve brain regions not typically involved in nociceptive intensity coding but likely mediate changes in the significance and/or value of pain
Evidence for Large-Scale Fluctuations in the Metagalactic Ionizing Background Near Redshift Six
The observed scatter in intergalactic Lyman- opacity at requires large-scale fluctuations in the neutral fraction of the
intergalactic medium (IGM) after the expected end of reionization.
Post-reionization models that explain this scatter invoke fluctuations in
either the ionizing ultraviolet background (UVB) or IGM temperature. These
models make very different predictions, however, for the relationship between
Lyman- opacity and local density. Here we test these models using
Lyman- emitting galaxies (LAEs) to trace the density field surrounding
the longest and most opaque known Lyman- trough at . Using deep
Subaru Hyper Suprime-Cam narrow-band imaging, we find a highly significant
deficit of LAEs within 20 Mpc/ of the trough. The results are
consistent with a model in which the scatter in Lyman- opacity near is driven by large-scale UVB fluctuations, and disfavor a scenario in
which the scatter is primarily driven by variations in IGM temperature. UVB
fluctuations at this epoch present a boundary condition for reionization
models, and may help shed light on the nature of the ionizing sources.Comment: 13 pages, 9 figure, submitted to ApJ, comments welcom
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