380 research outputs found
Cleaner wrasse forage on ectoparasitic Digeneans (Phylum Platyhelminthes) that infect pelagic thresher sharks (Alopias pelagicus)
The final publication is available at Springer via http://dx.doi.org/10.1007/s12526-014-0290-8This article discusses a study of ectoparasite specimens that were taken from the cloacas of dead pelagic thresher sharks caught in the central Visayas of the Philippines
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Nathaniel Topliff Allen, 1823-72 : a case study in the professionalization of nineteenth century teaching.
EducationDoctor of Education (Ed.D.
Radiation Protection Instrument Reliability and Ma
This report is a collection of reliability and ma
Post-transcriptional regulation of satellite cell quiescence by TTP-mediated mRNA decay.
Skeletal muscle satellite cells in their niche are quiescent and upon muscle injury, exit quiescence, proliferate to repair muscle tissue, and self-renew to replenish the satellite cell population. To understand the mechanisms involved in maintaining satellite cell quiescence, we identified gene transcripts that were differentially expressed during satellite cell activation following muscle injury. Transcripts encoding RNA binding proteins were among the most significantly changed and included the mRNA decay factor Tristetraprolin. Tristetraprolin promotes the decay of MyoD mRNA, which encodes a transcriptional regulator of myogenic commitment, via binding to the MyoD mRNA 3' untranslated region. Upon satellite cell activation, p38Ī±/Ī² MAPK phosphorylates MAPKAP2 and inactivates Tristetraprolin, stabilizing MyoD mRNA. Satellite cell specific knockdown of Tristetraprolin precociously activates satellite cells in vivo, enabling MyoD accumulation, differentiation and cell fusion into myofibers. Regulation of mRNAs by Tristetraprolin appears to function as one of several critical post-transcriptional regulatory mechanisms controlling satellite cell homeostasis
Tritium Room Air Monitor Operating Experience Review
Monitoring the breathing air in tritium facility rooms for airborne tritium is a radiological safety requirement and a best practice for personnel safety. Besides audible alarms for room evacuation, these monitors often send signals for process shutdown, ventilation isolation, and cleanup system actuation to mitigate releases and prevent tritium spread to the environment. Therefore, these monitors are important not only to personnel safety but also to public safety and environmental protection. This paper presents an operating experience review of tritium monitor performance on demand during small (1 mCi to 1 Ci) operational releases, and intentional airborne inroom tritium release tests. The tritium tests provide monitor operation data to allow calculation of a statistical estimate for the reliability of monitors annunciating in actual tritium gas airborne release situations. The data show a failure to operate rate of 3.5E-06/monitor-hr with an upper bound of 4.7E-06, a failure to alarm on demand rate of 1.4E-02/demand with an upper bound of 4.4E-02, and a spurious alarm rate of 0.1 to 0.2/monitor-yr
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Hydrogen and Gaseous Fuel Safety and Toxicity
Non-traditional motor fuels are receiving increased attention and use. This paper examines the safety of three alternative gaseous fuels plus gasoline and the advantages and disadvantages of each. The gaseous fuels are hydrogen, methane (natural gas), and propane. Qualitatively, the overall risks of the four fuels should be close. Gasoline is the most toxic. For small leaks, hydrogen has the highest ignition probability and the gaseous fuels have the highest risk of a burning jet or cloud
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Preliminary Identification of Accident Initiating Events for IFE Power Plants
This paper presents initial results of a task to identify accident initiating events for inertial fusion energy (IFE) power plant designs. Initiating events (IEs) are a fundamental building block of a probabilistic risk assessment; they are the āaccident startersā that are analyzed to determine the risks posed to members of the public in the vicinity of the power plant. The IE results for the SOMBRERO design are presented in tabular form. The SOMBRERO design was analyzed since it is representative of dry chamber wall, laser driven designs. This work is used to characterize IFE plant risk and to identify potential design changes that would mitigate the plant risk
Psychophysiological Measures of Driver Distraction and Workload While Intoxicated
The crash risk associated with cell phone use while driving is acontentious issue. Many states are introducing Advanced Traveler InformationSystems (ATIS) that may be accessed with cell phones while driving (e.g., 511Traveler Information Services). In these contexts, there is a need for relevantresearch to determine the risk of cell phone use. This study compared driverperformance while conversing on a hands-free cell phone to conditions ofoperating common in-vehicle controls (e.g., radio, fan, air conditioning) andalcohol intoxication (BAC 0.08). In addition, the study examined the combinedeffects of being distracted and being intoxicated given that there may be a higherrisk of a crash if the driver engages in a combination of risk factors. Duringsimulated traffic scenarios, resource allocation was assessed through an eventrelatedpotential (ERP) novelty oddball paradigm. Intoxicated drivers were lessattentive to all stimuli and drivers engaged in secondary tasks had weakerresponses to unexpected novel sounds in brain regions associated with evaluativeprocessing. Drivers conversing on the cell phone and in-vehicle tasks while soberhad lower accuracy during the target tone task than intoxicated drivers notcompleting any secondary task
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Occupational Radiation Exposure Analysis of US ITER DCLL TBM
This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM
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Hydrogen and Oxygen Gas Monitoring System Design and Operation
This paper describes pertinent design practices of selecting types of monitors, monitor unit placement, setpoint selection, and maintenance considerations for gas monitors. While hydrogen gas monitors and enriched oxygen atmosphere monitors as they would be needed for hydrogen production experiments are the primary focus of this paper, monitors for carbon monoxide and carbon dioxide are also discussed. The experiences of designing, installing, and calibrating gas monitors for a laboratory where experiments in support of the DOE Nuclear Hydrogen Initiative (NHI) are described along with codes, standards, and regulations for these monitors. Information from the literature about best operating practices is also presented. The NHI program has two types of activities. The first, near-term activity is laboratory and pilot-plant experimentation with different processes in the kilogram per day scale to select the most promising types of processes for future applications of hydrogen production. Prudent design calls for indoor gas monitors to sense any hydrogen leaks within these laboratory rooms. The second, longer-term activity is the prototype, or large-scale plants to produce tons of hydrogen per day. These large, outdoor production plants will require area (or āfencepostā) monitoring of hydrogen gas leaks. Some processes will have oxygen production with hydrogen production, and any oxygen releases are also safety concerns since oxygen gas is the strongest oxidizer. Monitoring of these gases is important for personnel safety of both indoor and outdoor experiments. There is some guidance available about proper placement of monitors. The fixed point, stationary monitor can only function if the intruding gas contacts the monitor. Therefore, monitor placement is vital to proper monitoring of the room or area. Factors in sensor location selection include: indoor or outdoor site, the location and nature of potential vapor/gas sources, chemical and physical data of the gases or vapors, liquids with volatility need sensors near the potential sources of release, nature and concentration of gas releases, natural and mechanical ventilation, detector installation locations not vulnerable to mechanical or water damage from normal operations, and locations that lend themselves to convenient maintenance and calibration. The guidance also states that sensors should be located in all areas where hazardous accumulations of gas may occur. Such areas might not be close to release points but might be areas with restricted air movement. Heavier than air gases are likely to accumulate in pits, trenches, drains, and other low areas. Lighter than air gases are more likely to accumulate in overhead spaces, above drop ceilings, etc. In general, sensors should be located close to any potential sources of major release of gas. The paper gives data on monitor sensitivity and expected lifetimes to support the monitor selection process. Proper selection of indoor and outdoor locations for monitors is described, accounting for the vapor densities of hydrogen and oxygen. The latest information on monitor alarm setpoint selection is presented. Typically, monitors require recalibration at least every six months, or more frequently for inhospitable locations, so ready access to the monitors is an important issue to consider in monitor siting. Gas monitors, depending on their type, can be susceptible to blockages of the detector element (i.e., du
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