94 research outputs found

    A Prototype for a Distributed Space Physics Data System

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    The collaborative analysis of data within the Space Physics community is hindered, in part, by the wide number of data formats and the wide distribution of data archives. In an attempt to address these two problems we have implemented a prototype which retrieves datasets, stored in different data formats at several remote locations. Our prototype uses the Key Parameter Visualization Tools (KPVT) and the Distributed Oceanographic Data System (DODS) to view data from the ISEE1, ISEE2, and ISTP programs. Our goal is to demonstrate the ability to access and use several types of remote data and existing analysis tools. The work described demonstrates the power of an expressive data model, like the one in DODS, for converting and transmitting space physics data. Furthermore, since the DODS system architecture (and associated data model) was developed to meet oceanographic needs, the fact that it works well for use within the space physics community suggests that the DODS approach will also work well as a data distribution mechanism for the other earth science sub-disciplines. Given the growing interest in interdisciplinary work in the earth sciences the existence of a data model/system capable of spanning the various sub-disciplines is significant

    Ionized Ultraviolet and Soft-X-ray Absorptions in the Low Redshift Active Galactic Nucleus PG1126-041

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    We present here the analysis of ultraviolet spectra from IUE and an X-ray spectrum from ROSAT PSPC observations of the X-ray weak, far-infrared loud AGN, PG 1126-041 (Mrk 1298). The first UV spectra taken in June 1992, simultaneously with ROSAT, show strong absorption lines of NV, CIV and SiIV, extending over a velocity range from -1000 to -5000 km/s with respect to the corresponding line centre. Our analysis shows that the Broad Emission Line Region (BELR) is, at least partially, covered by the material causing these absorption lines. In the IUE spectrum taken in Jan. 1995, the continuum was a factor of two brighter and the UV absorption lines are found to be considerably weaker than in 1992, but only little variation in the emission line fluxes is found. With UV spectral indices of A_{uv} \simeq 1.82 and 1.46 for the 1992 and 1995 data, the far UV spectrum is steep. Based on the emission line ratios and the broad band spectral energy distribution, we argue that the steepness of the UV spectrum is unlikely to be due to reddening. The soft X-ray emission in the ROSAT band is weak. A simple power-law model yields a very poor fit with a UV-to-X-ray spectral index A_{uvx}=2.32. Highly ionized (warm) absorption is suggested by the ROSAT data. After correcting for a warm absorber, the optical to X-ray spectral slope is close to the average of A{uvx}\simeq 1.67 for radio quiet quasars.Comment: 8 pages, 9 postscript figures. Mon. Not. Roy. Astr. Soc., accepte

    Adapting adaptive design methods to accelerate adoption of a digital asthma management intervention

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    Investigators conducting translational research in real-world settings may experience changes that create challenges to the successful completion of the trial as well as post-trial adoption and implementation. Adaptive designs support translational research by systematically adapting content and methods to meet the needs of target populations, settings and contexts. This manuscript describes an adaptive implementation research model that provides strategies for changing content, delivery processes, and research methods to correct course when anticipated and unanticipated circumstances occur during a pragmatic trial. The Breathewell Program included two large pragmatic trials of the effectiveness of a digital communication technology intervention to improve symptom management and medication adherence in asthma care. The first trial targeted parents of children with asthma; the second targeted adults with asthma. Adaptations were made iteratively to adjust to dynamic conditions within the healthcare setting, informed by prospectively collected stakeholder input, and were categorized retrospectively by the authors as proactive or reactive. Study outcomes demonstrated improved treatment adherence and clinical efficiency. Kaiser Permanente Colorado, the setting for both studies, adopted the speech recognition intervention into routine care, however, both interventions required numerous adaptations, including changes to target population, intervention content, and internal workflows. Proactive and reactive adaptations assured that both trials were successfully completed. Adaptive research designs will continue to provide an important pathway to move healthcare delivery research into practice while conducting ongoing effectiveness evaluation.Ye

    Polarization properties of broad absorption line QSOs : new statistical clues

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    We report the results of statistical tests performed on a sample of 139 broad absorption line (BAL) QSOs with good quality optical spectra and/or optical polarization data. Correlations between optical indices and the polarization degree p_0 are systematically searched for. In order to identify the most important correlations, we perform a principal component analysis with a sample of 30 BAL QSOs and eight quantities (including p_0). Most of the variance in the data is contained in two principal components (PC): PC1 is mainly dominated by the correlation between the balnicity index BI and the strength of the feii emission, and may be driven by the accretion rate of matter onto the central compact object. The variance in PC2 is essentially due to the anti-correlation between p_0 and the detachment index DI. PC2 may be related to the orientation of the BAL QSOs with respect to the line of sight. We also consider a spectropolarimetric sample of 21 BAL QSOs for which we define four indices describing the polarization properties of the absorption and emission lines. We find a possible anti-correlation between the detachment index and a quantity SI which measures the ratio of the depths of the civ absorption in the polarized flux and in the total flux. This correlation indicates that in BAL QSOs with P cygni profiles, the BAL troughs in the polarized flux are nearly as deep as in the total flux while, in BAL QSOs with detached absorptions, the BAL troughs in the polarized flux are much weaker than in the total flux. We show that our main results may be explained in the framework of a 'two-component' wind model. In this model, the broad absorption occurs in a dense equatorial wind emerging from the accretion disk, while scattering and polarization mainly take place in a polar region.Comment: 18 pages, 8 figures, to be published in Astronomy & Astrophysic

    Transition to Virtual Asthma Care During the COVID-19 Pandemic: An Observational Study

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    BACKGROUND: The COVID-19 pandemic increased reliance on virtual care for patients with persistent asthma. OBJECTIVE: This retrospective cohort study assessed changes from in-person to virtual care during the pandemic. In patients with persistent asthma, compared with the same period before the pandemic. METHODS: Kaiser Permanente Colorado members aged 18 to 99 years with persistent asthma were evaluated during two periods (March to October 2019 and March to October 2020). Comparison of asthma exacerbations (hospitalizations, emergency department visits, and courses of oral prednisone) and asthma medication metrics were evaluated between the two periods and by type of care received during the pandemic (no care, virtual care only, in-person care only, or a mix of virtual and in-person care). Population characteristics by type of care received during the pandemic were also evaluated. RESULTS: Among 7,805 adults with persistent asthma, those who used more virtual care or sought no care during the pandemic were younger and had fewer comorbidities, mental health diagnoses, or financial barriers. Exacerbations decreased (0.264 to 0.214; P <.001) as did courses of prednisone (0.213 to 0.169). Asthma medication adherence (0.53 to 0.54; P <.001) and the asthma medication ratio, a quality-of-care metric (0.755 to 0.762; P [ .019), increased slightly. Patients receiving a mix of in-person and virtual care had the highest rate of exacerbations (0.83) and a lower asthma medication ratio (0.74) despite having the highest adherence (.57). CONCLUSIONS: Despite an increase in virtual care, asthma exacerbations decreased except among individuals who received both in-person and virtual care, likely because they had more severe disease.Ye

    Can digital communication technology reduce health system personnel time? An evaluation of personnel requirements and costs in a randomized controlled trial

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    Use of digital communication technologies (DCT) shows promise for enhancing outcomes and efficiencies in asthma care management. However, little is known about the impact of DCT interventions on healthcare personnel requirements and costs, thus making it difficult for providers and health systems to understand the value of these interventions. This study evaluated the differences in healthcare personnel requirements and costs between usual asthma care (UC) and a DCT intervention (Breathewell) aimed at maintaining guidelines-based asthma care while reducing health care staffing requirements. We used data from a pragmatic, randomized controlled trial conducted in a large integrated health system involving 14,978 patients diagnosed with asthma. To evaluate differences in staffing requirements and cost between Breathewell and UC needed to deliver guideline-based care we used electronic health record (EHR) events, provider time tracking surveys, and invoicing. Differences in cost were reported at the patient and health system level. The Breathewell intervention significantly reduced personnel requirements with a larger percentage of participants requiring no personnel time (45% vs. 5%, p < .001) and smaller percentage of participants requiring follow-up outreach (44% vs. 68%, p < .001). Extrapolated to the total health system, cost for the Breathewell intervention was $16,278 less than usual care. The intervention became cost savings at a sample size of at least 957 patients diagnosed with asthma. At the population level, using DCT to compliment current asthma care practice presents an opportunity to reduce healthcare personnel requirements while maintaining population-based asthma control measures.Ye

    A field investigation of phreatophyte-induced fluctuations in the water table

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    This is the published version. Copyright American Geophysical Union[1] Hydrographs from shallow wells in vegetated riparian zones frequently display a distinctive pattern of diurnal water table fluctuations produced by variations in plant water use. A multisite investigation assessed the major controls on these fluctuations and the ecohydrologic insights that can be gleaned from them. Spatial and temporal variations in the amplitude of the fluctuations are primarily a function of variations in (1) the meteorological drivers of plant water use, (2) vegetation density, type, and vitality, and (3) the specific yield of sediments in the vicinity of the water table. Past hydrologic conditions experienced by the riparian zone vegetation, either in previous years or earlier within the same growing season, are also an important control. Diurnal water table fluctuations can be considered a diagnostic indicator of groundwater consumption by phreatophytes at most sites, so the information embedded within these fluctuations should be more widely exploited in ecohydrologic studies
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