1,265 research outputs found
A computer operated mass spectrometer system
Digital computer system for processing mass spectrometer output dat
Computer control of mass analyzers
Digital computer control of mass spectrometer
Promoting a Culture of Safety: Use of the Hospital Survey on Patient Safety Culture in CAHs (Briefing Paper #30)
The Institute of Medicine has emphasized the importance of establishing a culture of safety to improve patient care, specifically: developing clear, highly visible patient safety programs that focus organizational attention on safety; using non-punitive systems for reporting and analyzing errors; incorporating well-established safety principles such as standardized and simplified equipment, supplies, and work processes; and establishing proven interdisciplinary team training programs for providers. We sought to investigate the degree to which these elements are present or absent in Critical Access Hospitals.
This report presents the results of a literature review and a rural patient safety expert panel comprised of representatives from federal and state government and academia. There is another policy brief that summarizes these same findings
Effects of air pollution on the nervous system and its possible role in neurodevelopmental and neurodegenerative disorders
Recent extensive evidence indicates that air pollution, in addition to causing respiratory and cardiovascular diseases, may also negatively affect the brain and contribute to central nervous system diseases. Air pollution is comprised of ambient particulate matter (PM) of different sizes, gases, organic compounds, and metals. An important contributor to PM is represented by traffic-related air pollution, mostly ascribed to diesel exhaust (DE). Epidemiological and animal studies have shown that exposure to air pollution may be associated with multiple adverse effects on the central nervous system. In addition to a variety of behavioral abnormalities, the most prominent effects caused by air pollution are oxidative stress and neuro-inflammation, which are seen in both humans and animals, and are supported by in vitro studies. Among factors which can affect neurotoxic outcomes, age is considered most relevant. Human and animal studies suggest that air pollution may cause developmental neurotoxicity, and may contribute to the etiology of neurodevelopmental disorders, including autism spectrum disorder. In addition, air pollution exposure has been associated with increased expression of markers of neurodegenerative disease pathologies, such as alpha-synuclein or beta-amyloid, and may thus contribute to the etiopathogenesis of neurodegenerative diseases, particularly Alzheimer's disease and Parkinson's disease
Diffuse Galactic Soft Gamma-Ray Emission
The Galactic diffuse soft gamma-ray (30-800 keV) emission has been measured
from the Galactic Center by the HIREGS balloon-borne germanium spectrometer to
determine the spectral characteristics and origin of the emission. The
resulting Galactic diffuse continuum is found to agree well with a single
power-law (plus positronium) over the entire energy range, consistent with RXTE
and COMPTEL/CGRO observations at lower and higher energies, respectively. We
find no evidence of spectral steepening below 200 keV, as has been reported in
previous observations. The spatial distribution along the Galactic ridge is
found to be nearly flat, with upper limits set on the longitudinal gradient,
and with no evidence of an edge in the observed region. The soft gamma-ray
diffuse spectrum is well modeled by inverse Compton scattering of interstellar
radiation off of cosmic-ray electrons, minimizing the need to invoke
inefficient nonthermal bremsstrahlung emission. The resulting power requirement
is well within that provided by Galactic supernovae. We speculate that the
measured spectrum provides the first direct constraints on the cosmic-ray
electron spectrum below 300 MeV.Comment: 26 pages, 7 figure, submitted to Ap
Ten per cent polarized optical emission from GRB 090102
The nature of the jets and the role of magnetic fields in gamma-ray bursts
(GRB) remains unclear. In a baryon-dominated jet only weak, tangled fields
generated in situ through shocks would be present. In an alternative model,
jets are threaded with large scale magnetic fields that originate at the
central engine and which accelerate and collimate the jets. The way to
distinguish between the models is to measure the degree of polarization in
early-time emission, however previous claims of gamma-ray polarization have
been controversial. Here we report that the early optical emission from GRB
090102 was polarized at the level of P=10+/-1%, indicating the presence of
large-scale fields originating in the expanding fireball. If the degree of
polarization and its position angle were variable on timescales shorter than
our 60-s exposure, then the peak polarization may have been larger than 10 per
cent.Comment: 16 pages, 4 figures. Published in Nature (2009), Vol. 462, p767-76
Possible Detection of an Emission Cyclotron Resonance Scattering Feature from the Accretion-powered Pulsar 4U 1626-67
We present analysis of 4U 1626-67, a 7.7 s pulsar in a low-mass X-ray binary
system, observed with the hard X-ray detector of the Japanese X-ray satellite
Suzaku in March 2006 for a net exposure of \sim88 ks. The source was detected
at an average 10-60 keV flux of \sim4 x10^-10 erg cm^-2 s^-1. The
phase-averaged spectrum is reproduced well by combining a negative and positive
power-law times exponential cutoff (NPEX) model modified at \sim 37 keV by a
cyclotron resonance scattering feature (CRSF). The phase-resolved analysis
shows that the spectra at the bright phases are well fit by the NPEX with CRSF
model. On the other hand, the spectrum in the dim phase lacks the NPEX
high-energy cutoff component, and the CRSF can be reproduced by either an
emission or an absorption profile. When fitting the dim phase spectrum with the
NPEX plus Gaussian model, we find that the feature is better described in terms
of an emission rather than an absorption profile. The statistical significance
of this result, evaluated by means of an F-test, is between 2.91 x 10^-3 and
1.53 x 10^-5, taking into account the systematic errors in the background
evaluation of HXD-PIN. We find that, the emission profile is more feasible than
the absorption one for comparing the physical parameters in other phases.
Therefore, we have possibly detected an emission line at the cyclotron
resonance energy in the dim phase.Comment: Accepted for publication in ApJ on March 16, 2012. 12 pages, 14
figure
The Wicked Machinery of Government: Malta and the Problems of Continuity under the New Model Administration
This is a study focused on the early years of British rule in Malta (1800-1813). It explores the application to the island of the “new model” of colonial government, one based on direct rule from London mediated by the continuation of existing laws and institutions. Systemic deficiencies are identified. These tended to undermine the effectiveness of direct British rule. This study also reveals, in the context of legal and constitutional continuity, unresolved tensions between modernity and tradition. The political stability of the island was damaged and the possibility of continued British possession was threatened
Magnetic Fields of Accreting X-Ray Pulsars with the Rossi X-Ray Timing Explorer
Using a consistent set of models, we parameterized the X-ray spectra of all
accreting pulsars in the Rossi X-ray Timing Explorer database which exhibit
Cyclotron Resonance Scattering Features (CRSFs, or cyclotron lines). These
sources in our sample are Her X-1, 4U 0115+63, Cen X-3, 4U 1626-67, XTE
J1946-274, Vela X-1, 4U 1907+09, 4U 1538-52, GX 301-2, and 4U 0352+309 (X Per).
We searched for correlations among the spectral parameters, concentrating on
how the cyclotron line energy relates to the continuum and therefore how the
neutron star B-field influences the X-Ray emission. As expected, we found a
correlation between the CRSF energy and the spectral cutoff energy. However,
with our consistent set of fits we found that the relationship is more complex
than what has been reported previously. Also, we found that not only does the
width of the cyclotron line correlate with the energy (as suggested by theory),
but that the width scaled by the energy correlates with the depth of the
feature. We discuss the implications of these results, including the
possibility that accretion directly affects the relative alignment of the
neutron star spin and dipole axes. Lastly, we comment on the current state of
fitting phenomenological models to spectra in the RXTE/BeppoSAX era and the
need for better theoretical models of the X-Ray continua of accreting pulsars.Comment: 36 Pages, 9 Figures, 9 Tables, ApJ in pres
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