1,518 research outputs found
Gammaâray optical counterpart search experiment (GROCSE)
The requirements of a gammaâray burst optical counterpart detector are reviewed. By taking advantage of realâtime notification of bursts, new instruments can make sensitive searches while the gammaâray transient is still in progress. A wide field of view camera at Livermore National Laboratories has recently been adapted for detecting GRB optical counterparts to a limiting magnitude of 8. A more sensitive camera, capable of reaching mv=14, is under development. © 1994 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87629/2/633_1.pd
Beam test results for the FiberGLAST instrument
The FiberGLAST scintillating fiber telescope is a large-area instrument concept for NASA\u27s GLAST program. The detector is designed for high-energy gamma-ray astronomy, and uses plastic scintillating fibers to combine a photon pair tracking telescope and a calorimeter into a single instrument. A small prototype detector has been tested with high energy photons at the Thomas Jefferson National Accelerator Facility. We report on the result of this beam test, including scintillating fiber performance, photon track reconstruction, angular resolution, and detector efficiency
Estimation of GRB detection by FiberGLAST
FiberGLAST is one of several instrument concepts being developed for possible inclusion as the primary Gamma-ray Large Area Space Telescope (GLAST) instrument. The predicted FiberGLAST effective area is more than 12,000 cm2 for energies between 30 MeV and 300 GeV, with a field of view that is essentially flat from 0°â80°. The detector will achieve a sensitivity more than 10 times that of EGRET. We present results of simulations that illustrate the sensitivity of FiberGLAST for the detection of gamma-ray bursts
Reducing Intravenous Narcotic Documentation Errors On the Electronic Anesthesia Record: A Quality Improvement Project
Medication errors are an important public health problem with high human and financial costs. Medication errors in anesthesia can result in patient morbidity or mortality and should be preventable. Evidence in the literature supports increasing computer access to reduce the number of medication errors. The purpose of this study was to determine if medication errors could be reduced in one university hospital through a clinical intervention of increasing computer access in the post-anesthesia care unit. A quantitative retrospective chart review was conducted. A statistical test of two independent proportions was used to examine the occurrence of schedule II (fentanyl) and IV (midazolam) controlled substance documentation errors before and after increasing computer access in the post-anesthesia care unit. Access to computers appeared to be associated with a reduction of medication errors from 2.3% to 1.5%. The compliance rate increased from 97.6% to 98.5%. The reduction in the error percentage was significant (z = 2.045, p = 0.04). Our findings provide objective evidence for the support of continuous process improvement to reduce medication errors in anesthesia
The Drosophila Female-Specific Sex-Determination Gene, Sex-Lethal, Has Stage-, Tissue-, and Sex-Specific RNAs Suggesting Multiple Modes of Regulation
For proper sexual development of females, the Sex-lethal (Sxl) gene must be activated early in development and remain on during the rest of the life cycle. Conversely, in males, Sxl must remain functionally off through development. Here, we show that the Sxl transcription unit spans a DNA segment of greater than 20 kb and encodes at least 10 distinct, but overlapping, RNA species. These RNAs range in size from 4.4 to 1.7 kb and exhibit sex, stage, and tissue specificity. Six RNAs, three female specific and three male specific, are first detected by midembryogenesis and persist through the adult stage: Their expression reflects the on/off regulation of Sxl\u27s activity at the level of sex-specific alternate splicing. Four Sxl RNAs are found in adult females. Two of these RNAs are dependent on the presence of a functional germ line and may be relevant to Sxl\u27s role in adult germ-line development. All four are present in unfertilized eggs. Finally, three Sxl RNAs are found only transiently during very early embryogenesis; we suggest that the expression of these RNAs may reflect an early regulation of Sxl at the level of transcription and that these transcripts are involved in the initial selection of the Sxl activity state in response to the primary sex-determination signal, the X/A ratio
Development and testing of a fiber/multianode photomultiplier system for use on FiberGLAST
A scintillating fiber detector is currently being studied for the NASA Gamma-Ray Large Area Space Telescope (GLAST) mission. This detector utilizes modules composed of a thin converter sheet followed by an x, y plane of scintillating fibers to examine the shower of particles created by high energy gamma-rays interacting in the converter material. The detector is composed of a tracker with 90 such modular planes and a calorimeter with 36 planes. The two major component of this detector are the scintillating fibers and their associated photodetectors. Here we present current status of development and test result of both of these. The Hamamatsu R5900-00-M64 multianode photomultiplier tube (MAPMT) is the baseline readout device. A characterization of this device has been performed including noise, cross- talk, gain variation, vibration, and thermal/vacuum test. A prototype fiber/MAPMT system has been tested at the Center for Advanced Microstructures and Devices at Louisiana State University with a photon beam and preliminary results are presented
Leptogenesis from R parity nonconservation
It is known that realistic neutrino masses for neutrino oscillations may be
obtained from R parity nonconserving supersymmetry. It is also known that such
interactions would erase any preexisting lepton or baryon asymmetry of the
Universe because of the inevitable intervention of the electroweak sphalerons.
We now show how a crucial subset of these R parity nonconserving terms may in
fact create its own successful leptogenesis.Comment: 4 pages latex file with one postscript figur
Results from GROCSE I: A real-time search for gamma ray burst optical counterparts
The GROCSE I experiment (Gamma-Ray Optical Counterpart Search Experiment) is a rapid slewing wide field of view optical telescope at Lawrence Livermore National Laboratory, which responds to triggers from the BATSE GRB data telemetry stream that have been processed and distributed by the BACODINE network. GROCSE I has been in continuous automated operation since January 1994. As of October 1995, sky images for 22 GRB triggers have been recorded, in some cases while the burst was still in progress. The preliminary analysis of eight of these events are presented here. No optical counterparts have yet been detected. Limits for optical emission are given. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87367/2/671_1.pd
Gamma ray burst optical counterpart search experiment (GROCSE)
GROCSE (Gamma-Ray Optical Counterpart Search Experiment) is a system of automated telescopes that search for simultaneous optical activity associated with gamma ray bursts in response to real-time burst notifications provided by the BATSE/BACODINE network. The first generation system, GROCSE I, is sensitive down to MV ⌠8.5MVâŒ8.5 and requires an average of 12 seconds to obtain the first images of the gamma ray burst error box defined by the BACODINE trigger. The collaboration is now constructing a second generation system which has a 4 second slewing time and can reach MV ⌠14MVâŒ14 with a 5 second exposure. GROCSE II consists of 4 cameras on a single mount. Each camera views the night sky through a commercial Canon lens (f/1.8,(f/1.8, focal length 200 mm) and utilizes a 2KĂ2K2KĂ2K Loral CCD. Light weight and low noise custom readout electronics were designed and fabricated for these CCDs. The total field of view of the 4 cameras is 17.6Ă17.6°.17.6Ă17.6°. GROCSE II will be operating by the end of 1995. In this paper, we present an overview of the GROCSE system and the results of measurements with a GROCSE II prototype unit. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87369/2/861_1.pd
Extensive air showers with TeV-scale quantum gravity
One of the possible consequences of the existence of extra degrees of freedom
beyond the electroweak scale is the increase of neutrino-nucleon cross sections
() beyond Standard Model predictions. At ultra-high energies
this may allow the existence of neutrino-initiated extensive air showers. In
this paper, we examine the most relevant observables of such showers. Our
analysis indicates that the future Pierre Auger Observatory could be
potentially powerful in probing models with large compact dimensions.Comment: 7 pages revtex, 5 eps fig
- âŠ