2,200 research outputs found
Focus on Quality: Communication in the Health Care Encounter
Outlines findings from focus groups on the role of effective communication between physicians and patients in improving the quality of health care and outcomes. Analyzes responses by race/ethnicity and gender. Includes recommendations
Stolen Wages in the Nation's Capital: Fixing DC's Broken Wage Theft Claims Process
Today in the District of Columbia ("the District" or "DC"), low wage workers are being shortchanged. Policies currently in place make it very difficult, to nearly impossible, for victims of wage theft to hold employers accountable for failing to pay wages owed. The Wage Theft Prevention Act of 2014, co-introduced on February 4, 2014 by Councilmembers Vincent Orange, Jim Graham, and Mary Cheh, would provide needed accountability and stronger protections to ensure that those working an honest day receive honest pay for their labor. This document provides an introduction to the current barriers affecting workers in the District, and presents an overview of the ways in which the Wage Theft Prevention Act of 2014 would ameliorate these problems; thereby making the District a better place for workers and responsible businesses
Setting evidence-based occupational exposure limits for manganese
In 2004, a review by the Institute of Environment and Health (IEH) made recommendations on occupational exposure limits (OELs) for manganese and its inorganic compounds for inhalable and respirable fractions respectively. These OELs were based on a detailed comprehensive evaluation of all the scientific data available at that time. Since then, more published studies have become available and a number of occupational standard-setting committees (EU SCOEL, US ACGIH-TLV, and German MAK) have proposed OEL’s for manganese and its inorganic compounds that are somewhat lower that those proposed in the 2004 review.
Based on current understanding, the key toxicological and human health issues that are likely to influence a health-based recommendation relate to: neurotoxicology; reproductive and developmental toxicology; and mutagenicity/carcinogenicity. Of these, it is generally considered that neurotoxicity presents the most sensitive endpoint. As such, many of the studies that have been reported since the IEH review have sought to use those neurofunctional tests that appear to be particularly sensitive at identifying the subtle neurological changes thought to associate with manganese toxicity. These recent studies have, however, continued to be limited to a significant extent by reliance on cross-sectional designs and also by use of unreliable exposure estimation methods. Consequently the strength of the potential association between manganese exposure and these subtle subclinical cognitive or neuromotor changes is still poorly characterised and the relevance of these minor differences in terms of either their clinical or quality of life consequences remains unknown.
Based upon the overall evidence, it is concluded that the 8-h time weighted averages (TWA) for respirable (0.05 mg/m3 as Mn) and inhalable (0.2 mg/m3 as Mn) fractions as recommended by the SCOEL in 2011 are the most methodologically-sound, as they are based on the best available studies, most suited to the development of health-based OELs for both respirable and inhalable fractions. The dose-response characterisation informed by the examined studies used can be considered to establish a true human NOAEL for all the neurofunctional endpoints examined within the selected studies
Familial Recurrence of Cerebral Palsy with Multiple Risk Factors
The recurrence of cerebral palsy in the same family is uncommon. We, however, report on two families with two or more affected siblings. In both families, numerous potential risk factors were identified including environmental, obstetric, and possible maternal effects. We hypothesize that multiple risk factors may lead to the increased risk of recurrence of cerebral palsy in families. Intrinsic and maternal risk factors should be investigated in all cases of cerebral palsy to properly counsel families on the risk of recurrence. Recent studies of genetic polymorphisms associated with cerebral palsy are considered with reference to our observations in these two families
VCU Internal Alignment Project
The purpose of this project was to see how many projects were actually implemented fully throughout the years of the program. The group members contacted others who they personally knew on the project teams of six prior projects that related to VCU Infrastructure (VCU Internal Alignment projects). Interestingly, in many cases these alumni volunteered input and constructive feedback on the institute as well. The projects included Campus Pride (2005), VCU Center for Research Excellence (2005), Monroe Park Fall Festival (2006), MERCI (2006), University Link Tank (2008), and The Next Generation (2009). All of the projects were drafted and presented in completion at the end of GEHLI. We found that only one project, Monroe Park Festival, was subsequently implemented in full
Caltech Core-Collapse Project (CCCP) observations of type IIn supernovae: typical properties and implications for their progenitor stars
Type IIn Supernovae (SNe IIn) are rare events, constituting only a few
percent of all core-collapse SNe, and the current sample of well observed SNe
IIn is small. Here, we study the four SNe IIn observed by the Caltech
Core-Collapse Project (CCCP). The CCCP SN sample is unbiased to the extent that
object selection was not influenced by target SN properties. Therefore, these
events are representative of the observed population of SNe IIn. We find that a
narrow P-Cygni profile in the hydrogen Balmer lines appears to be a ubiquitous
feature of SNe IIn. Our light curves show a relatively long rise time (>20
days) followed by a slow decline stage (0.01 to 0.15 mag/day), and a typical
V-band peak magnitude of M_V=-18.4 +/- 1.0 mag. We measure the progenitor star
wind velocities (600 - 1400 km/s) for the SNe in our sample and derive
pre-explosion mass loss rates (0.026 - 0.12 solar masses per year). We compile
similar data for SNe IIn from the literature, and discuss our results in the
context of this larger sample. Our results indicate that typical SNe IIn arise
from progenitor stars that undergo LBV-like mass-loss shortly before they
explode.Comment: ApJ, submitte
Hubble Space Telescope and Ground-Based Observations of Type Ia Supernovae at Redshift 0.5: Cosmological Implications
We present observations of the Type Ia supernovae (SNe) 1999M, 1999N, 1999Q,
1999S, and 1999U, at redshift z~0.5. They were discovered in early 1999 with
the 4.0~m Blanco telescope at Cerro Tololo Inter-American Observatory by the
High-z Supernova Search Team (HZT) and subsequently followed with many
ground-based telescopes. SNe 1999Q and 1999U were also observed with the Hubble
Space Telescope. We computed luminosity distances to the new SNe using two
methods, and added them to the high-z Hubble diagram that the HZT has been
constructing since 1995.
The new distance moduli confirm the results of previous work. At z~0.5,
luminosity distances are larger than those expected for an empty universe,
implying that a ``Cosmological Constant,'' or another form of ``dark energy,''
has been increasing the expansion rate of the Universe during the last few
billion years.Comment: 68 pages, 22 figures. Scheduled for the 01 February 2006 issue of
Ap.J. (v637
EVLA Observations Constrain the Environment and Progenitor System of Type Ia Supernova 2011fe
We report unique EVLA observations of SN 2011fe representing the most
sensitive radio study of a Type Ia supernova to date. Our data place direct
constraints on the density of the surrounding medium at radii ~10^15-10^16 cm,
implying an upper limit on the mass loss rate from the progenitor system of
Mdot <~ 6 x 10^-10 Msol/yr (assuming a wind speed of 100 km/s), or expansion
into a uniform medium with density n_CSM <~ 6 cm^-3. Drawing from the observed
properties of non-conservative mass transfer among accreting white dwarfs, we
use these limits on the density of the immediate environs to exclude a phase
space of possible progenitors systems for SN 2011fe. We rule out a symbiotic
progenitor system and also a system characterized by high accretion rate onto
the white dwarf that is expected to give rise to optically-thick accretion
winds. Assuming that a small fraction, 1%, of the mass accreted is lost from
the progenitor system, we also eliminate much of the potential progenitor
parameter space for white dwarfs hosting recurrent novae or undergoing stable
nuclear burning. Therefore, we rule out the most popular single degenerate
progenitor models for SN 2011fe, leaving a limited phase space inhabited by
some double degenerate systems and exotic progenitor scenarios.Comment: Accepted to Ap
Radio and X-ray observations of SN 2006jd: Another strongly interacting Type IIn supernova
We report four years of radio and X-ray monitoring of the Type IIn supernova
SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio
Telescope and Expanded Very Large Array; at X-ray wavelengths with {\em
Chandra}, {\em XMM-Newton} and {\em Swift}-XRT. We assume that the radio and
X-ray emitting particles are produced by shock interaction with a dense
circumstellar medium. The radio emission shows an initial rise that can be
attributed to free-free absorption by cool gas mixed into the nonthermal
emitting region; external free-free absorption is disfavored because of the
shape of the rising light curves and the low gas column density inferred along
the line of sight to the emission region. The X-ray luminosity implies a
preshock circumstellar density cm at a radius cm, but the column density inferred from the photoabsorption of X-rays
along the line of sight suggests a significantly lower density. The implication
may be an asymmetry in the interaction. The X-ray spectrum shows Fe line
emission at 6.9 keV that is stronger than is expected for the conditions in the
X-ray emitting gas. We suggest that cool gas mixed into the hot gas plays a
role in the line emission. Our radio and X-ray data both suggest the density
profile is flatter than because of the slow evolution of the
unabsorbed emission.Comment: Accepted for publication in ApJ without any change
Heterogeneous Variances in Multi-Environment Yield Trials for Corn Hybrids
Recent developments in statistics and computing have enabled much greater levels of complexity in statistical models of multi-environment yield trial data. One particular feature of interest to breeders is simultaneously modeling heterogeneity of variances among environments and hybrids. Our objective was to estimate the level of heterogeneity of genotype by environment interaction variance and error variance in the Iowa Crop Performance Test for Corn. A Bayesian approach was used to estimate variance components in a hierarchical model that allows for heterogeneous error and genotypeby- environment interaction (GEI) variances applied to corn yield data from the Iowa Crop Performance Test performed between 1995 and 2005. An average of 508 hybrids were tested per year with very little overlap between locations and years, which resulted in a very unbalanced data set. We divided the data into 16 subsets to study the effect of variability across locations and years. We found GEI and error variances to be heterogeneous among both environments and genotypes. Our results for corn contrasted previous work on oat (Avena sativa L.) in which very little heterogeneity was found for error variance among cultivars suggesting that different corn (Zea mays L.) hybrids can have different genotype by environment interaction variances and different error variances
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