53 research outputs found

    Preliminary results from the ISAMS NO channel: Thermospheric radiances

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    The Improved Stratospheric and Mesospheric Sounder (ISAMS) is producing the first global measurements of emission from the 1 yields 0 band of nitric oxide (NO). The emission from the lower thermosphere has been examined and is seen to increase dramatically at times corresponding to high solar activity. The temporal and geographical extent of the effect is reported, and possible mechanisms for the enhanced emission are discussed. The need for adequate representation of thermospheric NO emission in order to retrieve NO number densities at all heights from ISAMS data is discussed, as are prospects for science studies using such NO number density measurements

    ISAMS observations of stratospheric aerosol

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    The Improved Stratospheric and Mesospheric (ISAMS) on board the Upper Atmosphere Research Satellite (UARS) incorporates a 12.1 micron window channel for the measurement of aerosol opacity. The retrieval scheme is discussed briefly and preliminary observations of the Mt. Pinatubo aerosol cloud are presented and compared with SAGE 2 observations at 1.02 microns. The effect of aerosol on other ISAMS channels and its spectral dependence is discussed

    The validation of ozone measurements from the improved stratospheric and mesospheric sounder

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    We present preliminary results of the validation of ozone measurements from the Improved Stratospheric and Mesospheric Sounder (ISAMS). The indications are that the ISAMS provides ozone data which generally agrees with other experiments and climatological values, except in regions of large thermal gradients or high aerosol loading. Corrections for these effects will be included in future reprocessing of the data

    Measurements of stratospheric NO, NO2, and N2O5 by ISAMS: Preliminary observations and data validation

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    The Improved Stratospheric and Mesospheric Sounder (ISAMS) is a multichannel radiometer and forms part of the science payload of the Upper Atmosphere Research Satellite (UARS). ISAMS measures infrared emissions from the Earth's atmosphere in several wavelength bands. Three such bands include emission from nitric oxide, nitrogen dioxide, and dinitrogen pentoxide. In this paper, we briefly discuss how the ISAMS instrument measures NO, NO2, and N2O5. We also present preliminary data from these channels and describe preliminary validation work

    Measurements of stratospheric constituents by ISAMS

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    ISAMS is a limb sounding radiometer flying on the UARS, and designed to measure temperature, pressure, O3, CO, NO, NO2, N2O5, HNO3, CH4, H2O, N2O, and aerosol. Its capabilities are described, together with the present status of validation of its data products, and plans for future improvement

    The ACTIVE cognitive training trial and predicted medical expenditures

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    <p>Abstract</p> <p>Background</p> <p>Health care expenditures for older adults are disproportionately high and increasing at both the individual and population levels. We evaluated the effects of the three cognitive training interventions (memory, reasoning, or speed of processing) in the ACTIVE study on changes in predicted medical care expenditures.</p> <p>Methods</p> <p>ACTIVE was a multisite randomized controlled trial of older adults (≥ 65). Five-year follow-up data were available for 1,804 of the 2,802 participants. Propensity score weighting was used to adjust for potential attrition bias. Changes in predicted annual<b/>medical expenditures were calculated at the first and fifth annual follow-up assessments using a new method for translating functional status scores. Multiple linear regression methods were used in this cost-offset analysis.</p> <p>Results</p> <p>At one and five years post-training, annual predicted expenditures declined<b/>by 223(p=.024)and223 (p = .024) and 128 (p = .309), respectively, in the speed of processing treatment group, but there were no statistically significant changes in the memory or reasoning treatment groups compared to the no-contact control group at either period. Statistical adjustment for age, race, education, MMSE scores, ADL and IADL performance scores, EPT scores, chronic condition counts, and the SF-36 PCS and MCS scores at baseline did not alter the one-year (244;p=.012)orfiveyear(244; p = .012) or five-year (143; p = .250) expenditure declines in the speed of processing treatment group.</p> <p>Conclusion</p> <p>The speed of processing intervention significantly reduced subsequent annual predicted medical care expenditures at the one-year post-baseline comparison, but annual savings were no longer statistically significant at the five-year post-baseline comparison.</p

    Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science

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    It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations

    John Theodore Houghton

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    Radiometry of the atmosphere of Mars

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    This thesis is concerned with a project to apply the method of pressure modulation radiometry to measurements of the temperature and water vapour distributions in the atmosphere of Mars. The technique has already been used successfully to measure temperature (and occasionally composition) in the atmospheres of Earth and Venus. Two pressure modulators, containing carbon dioxide and water vapour respectively, are used in the Pressure Modulator Infrared Radiometer (PMIRR), on the payload of Mars Observer, scheduled for launch in September 1992. The composition of the Martian atmosphere is almost pure CO2, so the emission lines are unusually broad, so that the mean pressure in the CO2 modulator has to be much larger than for previous modulators, thus increasing the power consumption. The limited power available in a Martian spacecraft requires that the power consumption of the pressure modulator and drive be minimized. As a result a high­efficiency drive circuit was designed and developed. Water vapour is of major importance to the Martian environment and there are several outstanding questions about its behaviour. Measurements using the pressure modulator technique for terrestrial water vapour measurements have had limited success, raising questions about its suitability for condensible, affinitive molecules. A new model of the thermodynamics of pressure modulators was developed to predict their mechanical and spectroscopic behaviour, and spectroscopic measurements of the pressure modulator cell transmission, with high spectral and temporal resolution, using a tunable diode laser spectrometer (TDLS), were performed. The measured transmission agrees well with the predictions of the model, indicating that pressure modulation radiometry can be applied to measurements of water vapour, giving confidence in the successful study of Martian climatology by the PMIRR instrument.Some figures have been removed from the pdf version of the thesis for copyright reasons

    Global cloud properties on Venus from orbital infrared spectroscopy

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    This thesis describes the derivation of Venusian global cloud properties from infrared remote sensing data obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the European Space Agency Venus Express satellite. A computationally-efficient retrieval method is designed to exploit the dataset, which provides coverage of the entire nightside southern hemisphere of Venus. Spatially-resolved near-infrared spectra have been used to derive improved models of the vertical structure and global distribution of cloud properties in the southern hemisphere. Wavelengths within transparency windows in the 1.0 - 2.6 micron range covered by VIRTIS are sensitive on the nightside to absorption by the lower and middle sulphuric acid cloud layers, which are back-lit by thermally-emitted radiation from the hot lower atmosphere (Taylor et al. 1997). The cloud model used to interpret the spectra builds on work by Crisp (1986), Pollack et al. (1993) and Grinspoon et al. (1993). Retrieved parameters are the acid concentration in the cloud droplets, the average size of the particles in the lower cloud and the altitude of the cloud base in the model. Values are estimated initially using wavelength pairs selected for their unique sensitivity to each parameter, and then validated using model spectra generated using the NEMESIS radiative transfer and retrieval code (Irwin et al. 2008) as developed for Venus (Tsang et al. 2008a). The spatial variation of sulphuric acid concentration in the cloud particles is estimated ; the concentration is found to be higher in regions of optically thick cloud. The retrieved cloud base altitude varies with latitude, reaching a maximum height near -50 degreees before falling by several km towards the pole. An increase in average particle size near the pole (Wilson et al. 2008) and the finding of latitudinally-variable CO abundance at 35 - 40 km altitude (Tsang et al. 2008) are both confirmed. A decrease in tropospheric H₂O abundance at high latitudes is observed, and provides evidence for strong downwelling between +/-60 and +/-75 degrees latitude, which marks the poleward extent of the Hadley cell circulation. Long-term secular change is also observed over a period of two Earth years. The measurements presented here provide a reference dataset for microphysical and dynamical modelling of the cloud deck, and the role of the cloud as a dynamical and chemical tracer means that such observations are of considerable value for increased understanding of the Venusian atmosphere.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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