764 research outputs found

    Investigating responses of comparable paper and computer opinion surveys

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    Research on integration of visual and motion cues for flight simulation and ride quality investigation

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    Vestibular perception and integration of several sensory inputs in simulation were studied. The relationship between tilt sensation induced by moving fields and those produced by actual body tilt is discussed. Linearvection studies were included and the application of the vestibular model for perception of orientation based on motion cues is presented. Other areas of examination includes visual cues in approach to landing, and a comparison of linear and nonlinear wash out filters using a model of the human vestibular system is given

    Chemistry Simulations Using MERRA-2 Reanalysis with the GMI CTM and Replay in Support of the Atmospheric Composition Community

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    Simulations using reanalyzed meteorological conditions have been long used to understand causes of atmospheric composition change over the recent past. Using the new Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) meteorology, chemistry simulations are being conducted to create products covering 1980-2016 for the atmospheric composition community. These simulations use the Global Modeling Initiative (GMI) chemical mechanism in two different models: the GMI Chemical Transport Model (CTM) and the GEOS-5 model developed Replay mode. Replay mode means an integration of the GEOS-5 general circulation model that is incrementally adjusted each time step toward the MERRA-2 analysis. The GMI CTM is a 1 x 1.25 simulation and the MERRA-2 GMI Replay simulation uses the native MERRA-2 approximately horizontal resolution on the cubed sphere. The Replay simulations is driven by the online use of key MERRA-2 meteorological variables (i.e. U, V, T, and surface pressure) with all other variables calculated in response to those variables. A specialized set of transport diagnostics is included in both runs to better understand trace gas transport and changes over the recent past

    The Frequency of Reevaluation or Peak Flow Meter Documentation in Acute Asthma Exacerbations in the Emergency Department: Are We Treating in Accordance with NIH/NAEPP Guidelines?

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    Objectives: To evaluate the frequency of peak expiratory flow rate (PEFR) measurement and clinical re-evaluation in the management of ED asthmatic patients. Methods: This was a retrospective chart review examining consecutive asthma patients who presented to the University of California Irvine ED between September 1, 2003 and December 31, 2003. Patients were excluded if they had a diagnosis of COPD, lung cancer, pneumonia, congestive heart failure, alpha 1 anti-trypsin deficiency or were under 5 years of age. Data collected included patient demographics, pulse oximetry reading(s), ED treatments rendered, and frequencies of PEFR measurement (pre and post therapy), of clinical re-evaluations in the ED, and of ED return visits. Results: Of the 122 ED visits from 111 patients, 11 (10%) patients returned during the 4 month study period, with 5 patients (4.5%) returning in less than 72 hours. Seven (6.0%) patients had PEFR done both pre and post treatment and 24 (20%) had one or more PEFR performed either before or after treatment. Only 61 (50%) of the visits had a documented clinical re-evaluation prior to disposition. Conclusions: Despite their documented role in asthma treatment algorithms, PEFR was performed infrequently and clinical re-evaluation was documented in only half of cases. Recommended algorithms for asthma management were not commonly followed in this academic ED

    Prevalence of positive mental health and functioning among adults with sickle cell disease in Ghana

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    Objectives: With increasing survival rates of children with sickle cell disease (SCD) reaching adulthood, there has been a growing interest in the quality of life and mental health functioning of affected individuals. Positive mental health is recognised as a significant dimension of human health that plays an important role in advancing well-being. This study explored the prevalence of positive mental health and functioning among a sample of Ghanaian adults with SCD. Methods: A quantitative cross-sectional survey design was implemented for data-gathering. A random sample of 62 adult SCD patients (21 to 56 years; mean age of 29 years) receiving treatment at the Sickle Cell Clinic of the Ghana Institute of Clinical Genetics at the Korle-Bu Teaching Hospital completed the Mental Health Continuum–Short Form (MHC-SF). Descriptive statistics and reliability indices were estimated for the MHC-SF. We implemented Keyes’s criteria for the assessment and categorisation of levels of mental health to determine the prevalence of positive mental health and functioning. Results: We found a high level of positive mental health (66% flourishing; 26% moderately mentally healthy; 8% languishing) and functioning, with no significant difference between the genders. A total of 34% of the participants were functioning at suboptimal levels and were at risk of psychopathology. Conclusion: This study gives the first overview of the prevalence of positive mental health and functioning in a clinical population in Ghana. Although the majority of participants were flourishing, contextually appropriate positive psychological interventions are needed to promote the mental health of SCD patients who are functioning at suboptimal levels, which would, inherently, also buffer against psychopathology

    M.I.T./Canadian Vestibular Experiments on the Spacelab-1 Mission. Part 1: Sensory Adaptation to Weightlessness and Readaptation to One-G: An Overview

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    Experiments on human spatial orientation were conducted on four crewmembers of Space Shuttle Spacelab Mission 1. The conceptual background of the project, the relationship among the experiments, and their relevance to a 'sensory reinterpretation hypothesis' are presented. Detailed experiment procedures and results are presented in the accompanying papers in this series. The overall findings are discussed as they pertain to the following aspects of hypothesized sensory reinterpretation in weightlessness: (1) utricular otolith afferent signals are reinterpreted as indicating head translation rather than tilt, (2) sensitivity of reflex responses to footward acceleration is reduced, and (3) increased weighting is given to visual and tactile cues in orientation perception and posture control. Results suggest increased weighting of visual cues and reduced weighting of graviceptor signals in weightlessness

    The Impact of New Estimates of Mixing Ratio and Flux-based Halogen Scenarios on Ozone Evolution

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    The evolution of ozone in the 21st century has been shown to be mainly impacted by the halogen emissions scenario and predicted changes in the circulation of the stratosphere. New estimates of mixing ratio and flux-based emission scenarios have been produced from the SPARC Lifetime Assessment 2013. Simulations using the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM) are conducted using this new A1 2014 halogen scenario and compared to ones using the A1 2010 scenario. This updated version of GEOSCCM includes a realistic representation of the Quasi-Biennial Oscillation and improvements related to the break up of the Antarctic polar vortex. We will present results of the ozone evolution over the recent past and 21st century to the A1 2010, A1 2014 mixing ratio, and an A1 2014 flux-based halogen scenario. Implications of the uncertainties in these estimates as well as those from possible circulation changes will be discussed

    Understanding Differences in Upper Stratospheric Ozone Response to Changes in Chlorine and Temperature as Computed Using CCMVal Models

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    Projections of future ozone levels are made using models that couple a general circulation model with a representation of atmospheric photochemical processes, allowing interactions among photochemical processes, radiation, and dynamics. Such models are known as chemistry and climate models (CCMs). Although developed from common principles and subject to the same boundary conditions, simulated ozone time series vary for projections of changes in ozone depleting substances (ODSs) and greenhouse gases. In the upper stratosphere photochemical processes control ozone level, and ozone increases as ODSs decrease and temperature decreases due to greenhouse gas increase. Simulations agree broadly but there are quantitative differences in the sensitivity of ozone to chlorine and to temperature. We obtain insight into these differences in sensitivity by examining the relationship between the upper stratosphere annual cycle of ozone and temperature as produced by a suite of models. All simulations conform to expectation in that ozone is less sensitive to temperature when chlorine levels are highest because chlorine catalyzed loss is nearly independent of temperature. Differences in sensitivity are traced to differences in simulated temperature, ozone and reactive nitrogen when chlorine levels are close to background. This work shows that differences in the importance of specific processes underlie differences in simulated sensitivity of ozone to composition change. This suggests a) the multi-model mean is not a best estimate of the sensitivity of upper ozone to changes in ODSs and temperature; b) the spread of values is not an appropriate measure of uncertainty

    Reducing Uncertainty in Chemistry Climate Model Predictions of Stratospheric Ozone

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    Chemistry climate models (CCMs) are used to predict the future evolution of stratospheric ozone as ozone-depleting substances decrease and greenhouse gases increase, cooling the stratosphere. CCM predictions exhibit many common features, but also a broad range of values for quantities such as year of ozone-return-to-1980 and global ozone level at the end of the 21st century. Multiple linear regression is applied to each of 14 CCMs to separate ozone response to chlorine change from that due to climate change. We show that the sensitivity of lower atmosphere ozone to chlorine change deltaO3/deltaCly is a near linear function of partitioning of total inorganic chlorine (Cly) into its reservoirs; both Cly and its partitioning are controlled by lower atmospheric transport. CCMs with realistic transport agree with observations for chlorine reservoirs and produce similar ozone responses to chlorine change. After 2035 differences in response to chlorine contribute little to the spread in CCM results as the anthropogenic contribution to Cly becomes unimportant. Differences among upper stratospheric ozone increases due to temperature decreases are explained by differences in ozone sensitivity to temperature change deltaO3/deltaT due to different contributions from various ozone loss processes, each with their own temperature dependence. In the lower atmosphere, tropical ozone decreases caused by a predicted speed-up in the Brewer-Dobson circulation may or may not be balanced by middle and high latitude increases, contributing most to the spread in late 21st century predictions

    Middle Atmosphere Response to Different Descriptions of the 11-Year Solar Cycle in Spectral Irradiance in a Chemistry-Climate Model

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    The 11-year solar cycle in solar spectral irradiance (SSI) inferred from measurements by the SOlar Radiation & Climate Experiment (SORCE) suggests a much larger variation in the ultraviolet than previously accepted. We present middle atmosphere ozone and temperature responses to the solar cycles in SORCE SSI and the ubiquitous Naval Research Laboratory (NRL) SSI reconstruction using the Goddard Earth Observing System chemistry-climate model (GEOS CCM). The results are largely consistent with other recent modeling studies. The modeled ozone response is positive throughout the stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with respect to total solar irradiance above 45 km. The modeled responses in total ozone are similar to those derived from satellite and ground-based measurements, 3-6 Dobson Units per 100 units of 10.7-cm radio flux (F10.7) in the tropics. The peak zonal mean tropical temperature response 50 using the SORCE SSI is nearly 2 K per 100 units 3 times larger than the simulation using the NRL SSI. The GEOS CCM and the Goddard Space Flight Center (GSFC) 2-D coupled model are used to examine how the SSI solar cycle affects the atmosphere through direct solar heating and photolysis processes individually. Middle atmosphere ozone is affected almost entirely through photolysis, whereas the solar cycle in temperature is caused both through direct heating and photolysis feedbacks, processes that are mostly linearly separable. Further, the net ozone response results from the balance of ozone production at wavelengths less than 242 nm and destruction at longer wavelengths, coincidentally corresponding to the wavelength regimes of the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) and Spectral Irradiance Monitor (SIM) on SORCE, respectively. A higher wavelength-resolution analysis of the spectral response could allow for a better prediction of the atmospheric response to arbitrary SSI variations
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