5,920 research outputs found
Infectious disease risk in asbestos abatement workers
BACKGROUND: The current literature reports increased infectious disease occurrence in various construction occupations, as an important contributor to morbidity and mortality arising from employment. These observations should be expanded to asbestos abatement workers, as the abatement can create an environment favorable for bacterial, viral and fungal infections. DISCUSSION: Asbestos abatement work employs activities resulting in cuts, blisters and abrasions to the skin, work in a dirty environment and exposure to dust, mists and fumes. Furthermore, this population exhibits a high smoking rate which increases the risk of chronic obstructive pulmonary disease and respiratory infections. In addition, these workers also commonly employ respirators, which can accumulate dirt and debris magnifying exposure to microbes. Use of respirators and related types of personal protective equipment, especially if shared and in the close environment experienced by workers, may enhance communicability of these agents, including viruses. SUMMARY: Abatement workers need to be provided with information on hazards and targeted by appropriate health education to reduce the infection risk. Epidemiological studies to investigate this risk in asbestos removers are recommended
Evaluation of SAMSON for use in a South Platte decision support system
December 1996.Includes bibliographical references (pages 28-29).The South Platte River basin is a tributary of the Missouri River. Three states share the basin (Colorado, Nebraska, and Wyoming), with most of the basin in Colorado (79 percent). Colorado's population has been growing rapidly, especially in Front-Range cities, increasing the demand on water resources in the basin. Highly productive plains agriculture is also a substantial user of water resources and new uses also can be expected for wildlife and recreation. A decision support system (DSS) is being planned by the State of Colorado for water management in South Platte River Basin. Anticipated needs of the system include data development and some model development specific to the South Platte. Due to the unique characteristics of the South Platte River Basin, the implementation of this framework is expected to be slightly different from other basins in Colorado. The SAMSON (Stream-Aquifer Model for Management by SimulatiON) Model, developed in the 1980s specifically for the South Platte River Basin, has been recommended by past studies for use in a South Platte DSS. This report provides and analysis of the current SAMSON model. The conclusions of this report recommend that SAMSON in its present form not be used as part of a DSS, largely due to recent developments in modeling philosophy, application, and use. SAMSON proved the entire South Platte River Basin system could be effectively modeled, and pointed to the priorities for data collection and development. Components of SAMSON could be part of future DSS systems, but they should be separated into individual modules and evaluated individually against existing models. In summary, the analysis of SAMSON clearly show the need for a modular and data-centered approach for a South Platte DSS.Grant no. 14-08-0001-G2008/5 Project no. 09; financed in part by the Department of the Interior, U.S. Geological Survey, through the Colorado Water Resources Research Institute
ATF4 Is an Oxidative Stress–Inducible, Prodeath Transcription Factor in Neurons in Vitro and in Vivo
Oxidative stress is pathogenic in neurological diseases, including stroke. The identity of oxidative stress-inducible transcription factors and their role in propagating the death cascade are not well known. In an in vitro model of oxidative stress, the expression of the bZip transcription factor activating transcription factor 4 (ATF4) was induced by glutathione depletion and localized to the promoter of a putative death gene in neurons. Germline deletion of ATF4 resulted in a profound reduction in oxidative stress-induced gene expression and resistance to oxidative death. In neurons, ATF4 modulates an early, upstream event in the death pathway, as resistance to oxidative death by ATF4 deletion was associated with decreased consumption of the antioxidant glutathione. Forced expression of ATF4 was sufficient to promote cell death and loss of glutathione. In ATF4(-/-) neurons, restoration of ATF4 protein expression reinstated sensitivity to oxidative death. In addition, ATF4(-/-) mice experienced significantly smaller infarcts and improved behavioral recovery as compared with wild-type mice subjected to the same reductions in blood flow in a rodent model of ischemic stroke. Collectively, these findings establish ATF4 as a redox-regulated, prodeath transcriptional activator in the nervous system that propagates death responses to oxidative stress in vitro and to stroke in vivo
CMB polarimetry with BICEP: instrument characterization, calibration, and performance
BICEP is a ground-based millimeter-wave bolometric array designed to target
the primordial gravity wave signature on the polarization of the cosmic
microwave background (CMB) at degree angular scales. Currently in its third
year of operation at the South Pole, BICEP is measuring the CMB polarization
with unprecedented sensitivity at 100 and 150 GHz in the cleanest available 2%
of the sky, as well as deriving independent constraints on the diffuse
polarized foregrounds with select observations on and off the Galactic plane.
Instrument calibrations are discussed in the context of rigorous control of
systematic errors, and the performance during the first two years of the
experiment is reviewed.Comment: 12 pages, 15 figures, updated version of a paper accepted for
Millimeter and Submillimeter Detectors and Instrumentation for Astronomy IV,
Proceedings of SPIE, 7020, 200
Fundamental scaling laws of on-off intermittency in a stochastically driven dissipative pattern forming system
Noise driven electroconvection in sandwich cells of nematic liquid crystals
exhibits on-off intermittent behaviour at the onset of the instability. We
study laser scattering of convection rolls to characterize the wavelengths and
the trajectories of the stochastic amplitudes of the intermittent structures.
The pattern wavelengths and the statistics of these trajectories are in
quantitative agreement with simulations of the linearized electrohydrodynamic
equations. The fundamental distribution law for the durations
of laminar phases as well as the power law of the amplitude distribution
of intermittent bursts are confirmed in the experiments. Power spectral
densities of the experimental and numerically simulated trajectories are
discussed.Comment: 20 pages and 17 figure
Absolute polarization angle calibration using polarized diffuse Galactic emission observed by BICEP
We present a method of cross-calibrating the polarization angle of a
polarimeter using BICEP Galactic observations. \bicep\ was a ground based
experiment using an array of 49 pairs of polarization sensitive bolometers
observing from the geographic South Pole at 100 and 150 GHz. The BICEP
polarimeter is calibrated to +/-0.01 in cross-polarization and less than +/-0.7
degrees in absolute polarization orientation. BICEP observed the temperature
and polarization of the Galactic plane (R.A= 100 degrees ~ 270 degrees and Dec.
= -67 degrees ~ -48 degrees). We show that the statistical error in the 100 GHz
BICEP Galaxy map can constrain the polarization angle offset of WMAP Wband to
0.6 degrees +\- 1.4 degrees. The expected 1 sigma errors on the polarization
angle cross-calibration for Planck or EPIC are 1.3 degrees and 0.3 degrees at
100 and 150 GHz, respectively. We also discuss the expected improvement of the
BICEP Galactic field observations with forthcoming BICEP2 and Keck
observations.Comment: 13 pages, 10 figures and 2 tables. To appear in Proceedings of SPIE
Astronomical Telescopes and Instrumentation 201
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