5,597 research outputs found
Comparable Worth in a General Equilibrium Model of the U.S. Economy
This paper presents a computable general equilibrium model that simulates the effects on employment, output, wages, and economic efficiency of introducing comparable worth into the U.S. economy. The model calculates economy-wide aggregate impacts and disaggregated results for individuals grouped by sex, marital status, and education. The effects depend on the hiring rules that would accompany comparable worth, the source of existing male-female wage differentials, the extent of coverage of comparable worth, the intra-household behavior of married couples, and demand and supply elasticities. If, after comparable worth is introduced, employers are constrained to employ men and women in historical proportions, the adverse effects on aggregate employment, output, and efficiency would be much larger than if the employment constraint is based on applicant proportions. If existing wage gaps are the result of sex differences in productivity, the adverse of facts of comparable worth are relatively large; but if they are the result of discrimination, the efficiency losses are much smaller. If only part of the economy is subject to comparable worth, the efficiency loss is reduced under the productivity gap assumption, but increased if the wage gap is the result of discrimination. The redistributive effects of comparable worth on married men and women are sensitive to assumptions about intra-household behavior and the size of the gains from marriage. By contrast, unmarried women appear to benefit from comparable worth under most sets of assumptions while unmarried men lose.
Ebola Virus Localization in the Macaque Reproductive Tract during Acute Ebola Virus Disease.
Sexual transmission of Ebola virus (EBOV) has been demonstrated more than a year after recovery from the acute phase of Ebola virus disease (EVD). The mechanisms underlying EBOV persistence and sexual transmission are not currently understood. Using the acute macaque model of EVD, we hypothesized EBOV would infect the reproductive tissues and sought to localize the infection in these tissues using immunohistochemistry and transmission electron microscopy. In four female and eight male macaques that succumbed to EVD between 6 and 9 days after EBOV challenge, we demonstrate widespread EBOV infection of the interstitial tissues and endothelium in the ovary, uterus, testis, seminal vesicle, epididymis, and prostate gland, with minimal associated tissue immune response or organ pathology. Given the widespread involvement of EBOV in the reproductive tracts of both male and female macaques, it is reasonable to surmise that our understanding of the mechanisms underlying sexual transmission of EVD and persistence of EBOV in immune-privileged sites would be facilitated by the development of a nonhuman primate model in which the macaques survived past the acute stage into convalescence
Treatment algorithm for infants diagnosed with spinal muscular atrophy through newborn screening
Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by the degeneration of alpha motor neurons in the spinal cord, leading to muscular atrophy. SMA is caused by deletions or mutations in the survival motor neuron 1 gene (SMN1). In humans, a nearly identical copy gene, SMN2, is present. Because SMN2 has been shown to decrease disease severity in a dose-dependent manner, SMN2 copy number is predictive of disease severity.
To develop a treatment algorithm for SMA-positive infants identified through newborn screening based upon SMN2 copy number.
A working group comprised of 15 SMA experts participated in a modified Delphi process, moderated by a neutral third-party expert, to develop treatment guidelines.
The overarching recommendation is that all infants with two or three copies of SMN2 should receive immediate treatment (n = 13). For those infants in which immediate treatment is not recommended, guidelines were developed that outline the timing and appropriate screens and tests to be used to determine the timing of treatment initiation.
The identification SMA affected infants via newborn screening presents an unprecedented opportunity for achievement of maximal therapeutic benefit through the administration of treatment pre-symptomatically. The recommendations provided here are intended to help formulate treatment guidelines for infants who test positive during the newborn screening process
Confronting Standard Models of Proto--Planetary Disks With New Mid--Infrared Sizes from the Keck Interferometer
We present near and mid-infrared interferometric observations made with the
Keck Interferometer Nuller and near-contemporaneous spectro-photometry from the
IRTF of 11 well known young stellar objects, several observed for the first
time in these spectral and spatial resolution regimes. With AU-level spatial
resolution, we first establish characteristic sizes of the infrared emission
using a simple geometrical model consisting of a hot inner rim and mid-infrared
disk emission. We find a high degree of correlation between the stellar
luminosity and the mid-infrared disk sizes after using near-infrared data to
remove the contribution from the inner rim. We then use a semi-analytical
physical model to also find that the very widely used "star + inner dust rim +
flared disk" class of models strongly fails to reproduce the SED and
spatially-resolved mid-infrared data simultaneously; specifically a more
compact source of mid-infrared emission is required than results from the
standard flared disk model. We explore the viability of a modification to the
model whereby a second dust rim containing smaller dust grains is added, and
find that the two-rim model leads to significantly improved fits in most cases.
This complexity is largely missed when carrying out SED modelling alone,
although detailed silicate feature fitting by McClure et al. 2013 recently came
to a similar conclusion. As has been suggested recently by Menu et al. 2015,
the difficulty in predicting mid-infrared sizes from the SED alone might hint
at "transition disk"-like gaps in the inner AU; however, the relatively high
correlation found in our mid-infrared disk size vs. stellar luminosity relation
favors layered disk morphologies and points to missing disk model ingredients
instead
Conceptual learning : the priority for higher education
The common sense notion of learning as the all-pervasive acquisition of new behaviour and knowledge, made vivid by experience, is an incomplete characterisation, because it assumes that the learning of behaviour and the learning of knowledge are indistinguishable, and that acquisition constitutes learning without reference to transfer. A psychological level of analysis is used to argue that conceptual learning should have priority in higher education
WFPC2 Observations of Compact Star Cluster Nuclei in Low Luminosity Spiral Galaxies
We have used the Wide Field Planetary Camera 2 aboard the Hubble Space
Telescope to image the compact star cluster nuclei of the nearby, late-type,
low-luminosity spiral galaxies NGC 4395, NGC 4242, and ESO 359-029. We also
analyze archival WFPC2 observations of the compact star cluster nucleus of M33.
A comparative analysis of the structural and photometric properties of these
four nuclei is presented. All of the nuclei are very compact, with luminosity
densities increasing at small radii to the resolution limit of our data. NGC
4395 contains a Seyfert 1 nucleus with a distinct bipolar structure and bright
associated filaments which are likely due to [OIII] emission. The M33 nucleus
has a complex structure, with elongated isophotes and possible signatures of
weak activity, including a jet-like component. The other two nuclei are not
known to be active, but share similar physical size scales and luminosities to
the M33 and NGC 4395 nuclei. The circumnuclear environments of all four of our
program galaxies are extremely diffuse, have only low-to-moderate star
formation, and appear to be devoid of large quantities of dust. The central
gravitational potentials of the galaxies are also quite shallow, making the
origin of these types of `naked' nuclei problematic.Comment: to appear in the July 1999 Astronomical Journal; 38 pages (Latex), 5
tables (postscript), 21 figures (gif); postscript versions of the figures may
be obtained via anonymous ftp at
ftp://ftp.cv.nrao.edu/NRAO-staff/lmatthew/lanl-nucle
UBVRI Light Curves of 44 Type Ia Supernovae
We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from
1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence
Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The
data set comprises 2190 observations and is the largest homogeneously observed
and reduced sample of SN Ia to date, nearly doubling the number of
well-observed, nearby SN Ia with published multicolor CCD light curves. The
large sample of U-band photometry is a unique addition, with important
connections to SN Ia observed at high redshift. The decline rate of SN Ia
U-band light curves correlates well with the decline rate in other bands, as
does the U-B color at maximum light. However, the U-band peak magnitudes show
an increased dispersion relative to other bands even after accounting for
extinction and decline rate, amounting to an additional ~40% intrinsic scatter
compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication
in the Astronomical Journal. Version with high-res figures and electronic
data at http://astron.berkeley.edu/~saurabh/cfa2snIa
- …
