1,630 research outputs found

    A combustion products analyzer for contingency use during thermodegradation events on spacecraft

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    The Toxicology Laboratory at JSC and Exidyne Instrumentation Technologies (EIT) have developed a prototype Combustion Products Analyzer (CPA) to monitor, in real time, combustion products from a thermodegradation event on board spacecraft. The CPA monitors the four gases that are the most hazardous compounds (based on the toxicity potential and quantity produced) likely to be released during thermodegradation of synthetic materials: hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen cyanide (HCN), and carbon monoxide (CO). The levels of these compounds serve as markers to assist toxicologists in determining when the cabin atmosphere is safe for the crew to breathe following the contingency event. The CPA is a hand-held, battery-operated instrument containing four electrochemical sensors, one for each target gas, and a pump for drawing air across the sensors. The sensors are unique in their small size and zero-g compatibility. The immobilized electrolytes in each sensor permit the instrument to function in space and eliminate the possibility of electrolye leaks. The sample inlet system is equipped with a particulate filter that prevents clogging from airborne particulate matter. The CPA has a large digital display for gas concentrations and warming signals for low flow and low battery conditions. The CPA has flown on 13 missions beginning with STS 41 in Oct. 1990. Current efforts include the development of a microprocessor, an improved carbon monoxide sensor, and a ground-based test program to evaluate the CPA during actual thermodegradation of selected materials

    Embedded point of care randomisation for evaluating comparative effectiveness questions: PROSPECTOR-critical care feasibility study protocol

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    INTRODUCTION: Many routinely administered treatments lack evidence as to their effectiveness. When treatments lack evidence, patients receive varying care based on the preferences of clinicians. Standard randomised controlled trials are unsuited to comparisons of different routine treatment strategies, and there remains little economic incentive for change.Integrating clinical trial infrastructure into electronic health record systems offers the potential for routine treatment comparisons at scale, through reduced trial costs. To date, embedded trials have automated data collection, participant identification and eligibility screening, but randomisation and consent remain manual and therefore costly tasks.This study will investigate the feasibility of using computer prompts to allow flexible randomisation at the point of clinical decision making. It will compare the effectiveness of two prompt designs through the lens of a candidate research question-comparing liberal or restrictive magnesium supplementation practices for critical care patients. It will also explore the acceptability of two consent models for conducting comparative effectiveness research. METHODS AND ANALYSIS: We will conduct a single centre, mixed-methods feasibility study, aiming to recruit 50 patients undergoing elective surgery requiring postoperative critical care admission. Participants will be randomised to either 'Nudge' or 'Preference' designs of electronic point-of-care randomisation prompt, and liberal or restrictive magnesium supplementation.We will judge feasibility through a combination of study outcomes. The primary outcome will be the proportion of prompts displayed resulting in successful randomisation events (compliance with the allocated magnesium strategy). Secondary outcomes will evaluate the acceptability of both prompt designs to clinicians and ascertain the acceptability of pre-emptive and opt-out consent models to patients. ETHICS AND DISSEMINATION: This study was approved by Riverside Research Ethics Committee (Ref: 21/LO/0785) and will be published on completion. TRIAL REGISTRATION NUMBER: NCT05149820

    Evidence-based vector control? Improving the quality of vector control trials.

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    Vector-borne diseases (VBDs) such as malaria, dengue, and leishmaniasis cause a high level of morbidity and mortality. Although vector control tools can play a major role in controlling and eliminating these diseases, in many cases the evidence base for assessing the efficacy of vector control interventions is limited or not available. Studies assessing the efficacy of vector control interventions are often poorly conducted, which limits the return on investment of research funding. Here we outline the principal design features of Phase III vector control field studies, highlight major failings and strengths of published studies, and provide guidance on improving the design and conduct of vector control studies. We hope that this critical assessment will increase the impetus for more carefully considered and rigorous design of vector control studies

    Cross Section Sensitivity and Propagated Errors in HZE Exposures

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    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates

    Anti-Nirvana: crime, culture and instrumentalism in the age of insecurity

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    ‘Anti-Nirvana’ explores the relationship between consumer culture, media and criminal motivations. It has appeared consistently on the list of the top-ten most-read articles in this award-winning international journal, and it mounts a serious neo-Freudian challenge to the predominant naturalistic notion of ‘resistance’ at the heart of liberal criminology and media studies. It is also cited in the Oxford Handbook of Criminology and other criminology texts as a persuasive argument in support of the theory that criminality amongst young people is strongly linked to the acquisitive values of consumerism and the images of possessive individualism that dominate mass media

    The Lantern Vol. 48, No. 1, December 1981

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    • While Sipping Scotch and Soda • I Remember • The Apology • Growing • It Seems Like Time Has Stood Still • Zimmerman Encounters Pessimism • Deliverer • Genus Sublime • Yours, Still • The Rising Sun • Person, Valley, Things • It Lay Motionless • Les Parques • Opportunity • The Park - I, II • Another Dimension • Grand Mal • Moments Later • Look Into A Pond • Trust and Dependency • From Foundlings • Drought • Girl at Fence • Campus • Clocking Time • A Letter From Clarence • When Flat Lines • Every Now and Then • Loneliness • Emotion No. 2 • You\u27re Walking • Battle Cries • The Ultimate Feudal Lord • Monologue From A Farther Roomhttps://digitalcommons.ursinus.edu/lantern/1119/thumbnail.jp

    NASA Radiation Protection Research for Exploration Missions

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    The HZETRN code was used in recent trade studies for renewed lunar exploration and currently used in engineering development of the next generation of space vehicles, habitats, and EVA equipment. A new version of the HZETRN code capable of simulating high charge and energy (HZE) ions, light-ions and neutrons with either laboratory or space boundary conditions with enhanced neutron and light-ion propagation is under development. Atomic and nuclear model requirements to support that development will be discussed. Such engineering design codes require establishing validation processes using laboratory ion beams and space flight measurements in realistic geometries. We discuss limitations of code validation due to the currently available data and recommend priorities for new data sets

    Space Weather Nowcasting of Atmospheric Ionizing Radiation for Aviation Safety

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    There is a growing concern for the health and safety of commercial aircrew and passengers due to their exposure to ionizing radiation with high linear energy transfer (LET), particularly at high latitudes. The International Commission of Radiobiological Protection (ICRP), the EPA, and the FAA consider the crews of commercial aircraft as radiation workers. During solar energetic particle (SEP) events, radiation exposure can exceed annual limits, and the number of serious health effects is expected to be quite high if precautions are not taken. There is a need for a capability to monitor the real-time, global background radiations levels, from galactic cosmic rays (GCR), at commercial airline altitudes and to provide analytical input for airline operations decisions for altering flight paths and altitudes for the mitigation and reduction of radiation exposure levels during a SEP event. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model is new initiative to provide a global, real-time radiation dosimetry package for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. The NAIRAS model brings to bear the best available suite of Sun-Earth observations and models for simulating the atmospheric ionizing radiation environment. Observations are utilized from ground (neutron monitors), from the atmosphere (the METO analysis), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations provide the overhead shielding information and the ground- and space-based observations provide boundary conditions on the GCR and SEP energy flux distributions for transport and dosimetry simulations. Dose rates are calculated using the parametric AIR (Atmospheric Ionizing Radiation) model and the physics-based HZETRN (High Charge and Energy Transport) code. Empirical models of the near-Earth radiation environment (GCR/SEP energy flux distributions and geomagnetic cut-off rigidity) are benchmarked against the physics-based CMIT (Coupled Magnetosphere- Ionosphere-Thermosphere) and SEP-trajectory models
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