1,367 research outputs found

    NASA/MSFC FY88 Global Scale Atmospheric Processes Research Program Review

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    Interest in environmental issues and the magnitude of the environmental changes continues. One way to gain more understanding of the atmosphere is to make measurements on a global scale from space. The Earth Observation System is a series of new sensors to measure globally atmospheric parameters. Analysis of satellite data by developing algorithms to interpret the radiance information improves the understanding and also defines requirements for these sensors. One measure of knowledge of the atmosphere lies in the ability to predict its behavior. Use of numerical and experimental models provides a better understanding of these processes. These efforts are described in the context of satellite data analysis and fundamental studies of atmospheric dynamics which examine selected processes important to the global circulation

    International study into the use of intermittent hormone therapy in the treatment of carcinoma of the prostate : A meta-analysis of 1446 patients

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    OBJECTIVE: To review pooled phase II data to identify features of different regimens of intermittent hormone therapy (IHT), developed to reduce the morbidity of treating metastatic prostate cancer, and which carries a theoretical advantage of delaying the onset of androgen-independent prostate cancer, (AIPC) that are associated with success, highlighting features which require exploration with prospective trials to establish the best strategies for using this treatment. METHODS: Individual data were collated on 1446 patients with adequate information, from 10 phase II studies with >50 cases, identified through Pubmed. RESULTS: Univariate and multivariate Cox proportional hazard models were developed to predict treatment success with a high degree of statistical success. The prostate-specific antigen (PSA) nadir, the PSA threshold to restart treatment, and medication type and duration, were important predictors of outcome. CONCLUSIONS: The duration of biochemical remission after a period of HT is a durable early indicator of how rapidly AIPC and death will occur, and will make a useful endpoint in future trials to investigate the best ways to use IHT based on the important treatment cycling variables described above. Patients spent a mean of 39% of the time off treatment. The initial PSA level and PSA nadir allow the identification of patients with prostate cancer in whom it might be possible to avoid radical therapy.Peer reviewe

    Strategies for Monitoring Multiuse Trail Networks: Implications for Practice

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    Many municipalities, park districts, and nonprofit organizations have begun monitoring nonmotorized traffic on multiuse trails as the need for information about the use of facilities has grown and relatively low-cost sensors for automated monitoring have become available. As they have gained experience, they have begun to move from site-specific monitoring on individual trails to a more comprehensive monitoring of trail networks. This case study review compares strategies developed by 10 organizations for monitoring traffic on multiuse trails, including local, multicounty, statewide, and multistate trail networks. The focus is on approaches to the design of monitoring networks, particularly the rationales or objectives for monitoring and the selection of monitoring sites. It is shown that jurisdictions are following principles of monitoring established by FHWA and that the design of monitoring networks is evolving to meet new challenges, including monitoring large-scale networks. Relevant outcomes and implications for practice are summarized. The researchers concluded that FHWA guidelines can be adapted to many circumstances and can increase information for decision making. Trail monitoring is informing decisions related to facility planning, investment, and safety

    A newly discovered radiation of endoparasitic gastropods and their coevolution with asteroid hosts in Antarctica

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    Funding Funding for this research comes from the Antarctic Circumnavigation Expedition, The University of Western Australia, and the National Science Foundation (USA) ANT-1043749. KKSL was supported by a University Postgraduate Award for International Students (UPAIS) and an RTP International Fees Offset scholarship (RTPFI) administered by The University of Western Australia, as well as a postgraduate doctoral scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC). These funding bodies did not have a role in the design of the study, the collection, analysis, and interpretation of data, or in writing the manuscript. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request and GenBank accessions appear in the manuscript.Peer reviewedPublisher PD

    Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

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    The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell concentration overpotential resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid-cathode feed water electrolysis cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration

    Challenges in Monitoring Regional Trail

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    This study reports traffic monitoring results at 30 locations on a 972-mi shared-use trail network across the east-central United States. We illustrate challenges in adapting the principles in the Federal Highway Administration’s Traffic Monitoring Guide to a regional trail network. We make four contributions: 1) we use factor analysis and k-means clustering to implement a stratified random process for selecting monitoring sites; 2) we illustrate quality assurance procedures and the challenges of obtaining valid results from a multi-state monitoring system; 3) we describe variation in trail traffic volumes across five land use classes in response to daily weather and seasons; and 4) we report two performance measures for the network: annual average daily trail traffic and trail miles traveled. The Rails to Trails Conservancy deployed passive infrared traffic monitors in 2015 through 2017. Site-specific regression models were used to impute missing daily traffic volumes. The effects of weather were consistent across land use classes but the effects of temporal variables, including weekend and season of year, varied. A plan for short-duration monitoring is presented. Results confirm the FHWA monitoring principles and the difficulties of implementing them regionally

    Carbon Monoxide: A Rare Cause of Myocardial Ischemia

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    In an acute care setting, chemical asphyxiants (CA) are a vice which cause debilitating injury. Carbon monoxide (CO) is one well known CA which causes hypoxic injury to cardiovascular and neurological tissue. CO poisoning is one of the leading causes of death in USA. As many as 6% of patients who get admitted with CO poisoning in the USA have acute myocardial infarction. A strong positive correlation of CO Hb concentration has been established with increased incidence of MIs. We present a case of a 75-year-old male with complaints of chest discomfort, dyspnea, diaphoresis that was attributed to CO poisoning. Over the course of his stay he had two sets of positive serial troponins and was diagnosed with a non-ST elevation MI. Most of the recent literature focuses on ST elevation and T wave inversions in patients with CO poisoning. Contrary to this, our patient did not exhibit any EKG changes at any point during his hospital course. CO poisoning can cause fatal complications including an MI

    Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

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    The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell resistance resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid cathode feed electrolyzer cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration

    Detailed Mass Map of CL0024+1654 from Strong Lensing

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    We construct a high resolution mass map of the z=0.39 cluster 0024+1654, based on parametric inversion of the associated gravitational lens. The lens creates eight well-resolved sub-images of a background galaxy, seen in deep imaging with HST. Excluding mass concentrations centered on visible galaxies, more than 98% of the remaining mass is represented by a smooth concentration of dark matter centered near the brightest cluster galaxies, with a 35 h^{-1} kpc soft core. The asymmetry in the mass distribution is <3% inside 107 ~h^{-1} kpc radius. The dark matter distribution we observe in CL0024 is far more smooth, symmetric, and nonsingular than in typical simulated clusters in either Omega=1 or Omega=0.3 CDM cosmologies. Integrated to 107 h^{-1} kpc radius, the rest-frame mass to light ratio is M/L_V = 276\pm 40 h (M/L_V)_solar.Comment: 16 pages, 4 figures (3 .jpg, 1 .ps), minor changes to make consistent with the final ApJL article. To appear in ApJL, May 8 199
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