2,642 research outputs found

    Analysis of the Workforce and Workplace for Rheumatology, and the Research Activities of Rheumatologists Early in Their Careers

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    [Excerpt] The scope and scale of clinical research is unknown for any medical or surgical specialty beyond snapshots of the broad aims and expenditures of research programs sponsored by federal agencies or the pharmaceutical industry. As a consequence, the workforce and workplace for clinical investigation is enigmatic and unexamined even after explicit warnings that an essential arm for advancing clinical practice has been disabled. The present study was designed to assess the workforce and workplace for rheumatology, and the extent and type of research prevailing among rheumatologists early in their careers. Our findings provide fresh insights about the workforce and the workplace for rheumatology, and justify interventions to address gaps in both the scope and scale of clinical research in arthritis and rheumatism

    The Scope and Scale of Clinical Research Accomplished by Rheumatologists Early in Their Careers

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    [Excerpt] The scope and scale of clinical research is unknown for any medical or surgical specialty beyond snap shots of the broad aims and expenditures of research programs sponsored by federal agencies or the pharmaceutical industry. As a consequence, the workforce and workplace for clinical investigation is enigmatic and unexamined even after explicit warnings that an essential arm for advancing clinical practice is disabled. The present study was designed to examine the nature and extent of investigative activity prevailing among rheumatologists early in their careers. This assessment provides a lens on: i) the fraction of early career rheumatologists who engage in investigative rheumatology, ii) the scope and scale of research in musculoskeletal diseases, iii) funding available for investigative work, iv) the impact of research-intensive institutions, and NIH-K-series awards on research, and v) the demographic backgrounds of early career rheumatologists. The results provide important new insights about the early career workforce for discovery and innovation in rheumatology. The findings integrate demographic, normative, and predictive data to provide the first estimate of the scope and scale of clinical investigation within rheumatology. The results also justify interventions for promoting investigative work, and ultimately advancing the clinical practice of rheumatology

    Four dimensional observations of clouds from geosynchronous orbit using stereo display and measurement techniques on an interactive information processing system

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    Simultaneous Geosynchronous Operational Environmental Satellite (GOES) 1 km resolution visible image pairs can provide quantitative three dimensional measurements of clouds. These data have great potential for severe storms research and as a basic parameter measurement source for other areas of meteorology (e.g. climate). These stereo cloud height measurements are not subject to the errors and ambiguities caused by unknown cloud emissivity and temperature profiles that are associated with infrared techniques. This effort describes the display and measurement of stereo data using digital processing techniques

    The GEMPAK Barnes objective analysis scheme

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    GEMPAK, an interactive computer software system developed for the purpose of assimilating, analyzing, and displaying various conventional and satellite meteorological data types is discussed. The objective map analysis scheme possesses certain characteristics that allowed it to be adapted to meet the analysis needs GEMPAK. Those characteristics and the specific adaptation of the scheme to GEMPAK are described. A step-by-step guide for using the GEMPAK Barnes scheme on an interactive computer (in real time) to analyze various types of meteorological datasets is also presented

    Direct Model-Based Inversion for Improved Freehand Optical Ultrasound Imaging

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    Optical ultrasound imaging uses light to both generate and detect pulse-echo ultrasound. Recently, we presented a fibre-optic optical ultrasound imaging probe comprising 64 sources and a single receiver that allowed for video-rate, freehand imaging. However, its low number of sources limited the image contrast when using Delay-and-Sum reconstruction. Here, we present an alternative image formation paradigm for optical ultrasound based on model-based inversion, where the low number of sources allows for direct (i.e., non-iterative) inversion under modest hardware requirements. The model accurately incorporates the aperture geometry, frequency-dependent source directivity, and performance variation across the aperture, thereby reducing image artefacts associated with these properties. The method achieves a 15 dB gain in image contrast compared to Delay-and-Sum, at a similar image formation time

    Multi-scale analysis of compressible viscous and rotating fluids

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    We study a singular limit for the compressible Navier-Stokes system when the Mach and Rossby numbers are proportional to certain powers of a small parameter \ep. If the Rossby number dominates the Mach number, the limit problem is represented by the 2-D incompressible Navier-Stokes system describing the horizontal motion of vertical averages of the velocity field. If they are of the same order then the limit problem turns out to be a linear, 2-D equation with a unique radially symmetric solution. The effect of the centrifugal force is taken into account

    Exploring X-ray Binary Populations in Compact Group Galaxies with ChandraChandra

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    We obtain total galaxy X-ray luminosities, LXL_X, originating from individually detected point sources in a sample of 47 galaxies in 15 compact groups of galaxies (CGs). For the great majority of our galaxies, we find that the detected point sources most likely are local to their associated galaxy, and are thus extragalactic X-ray binaries (XRBs) or nuclear active galactic nuclei (AGNs). For spiral and irregular galaxies, we find that, after accounting for AGNs and nuclear sources, most CG galaxies are either within the ±1σ\pm1\sigma scatter of the Mineo et al. (2012) LXL_X - star formation rate (SFR) correlation or have higher LXL_X than predicted by this correlation for their SFR. We discuss how these "excesses" may be due to low metallicities and high interaction levels. For elliptical and S0 galaxies, after accounting for AGNs and nuclear sources, most CG galaxies are consistent with the Boroson et al. (2011) LXL_X - stellar mass correlation for low-mass XRBs, with larger scatter, likely due to residual effects such as AGN activity or hot gas. Assuming non-nuclear sources are low- or high-mass XRBs, we use appropriate XRB luminosity functions to estimate the probability that stochastic effects can lead to such extreme LXL_X values. We find that, although stochastic effects do not in general appear to be important, for some galaxies there is a significant probability that high LXL_X values can be observed due to strong XRB variability.Comment: Accepted by Ap

    All-optical endoscopic probe for high resolution 3D photoacoustic tomography

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    A novel all-optical forward-viewing photoacoustic probe using a flexible coherent fibre-optic bundle and a Fabry- Perot (FP) ultrasound sensor has been developed. The fibre bundle, along with the FP sensor at its distal end, synthesizes a high density 2D array of wideband ultrasound detectors. Photoacoustic waves arriving at the sensor are spatially mapped by optically scanning the proximal end face of the bundle in 2D with a CW wavelength-tunable interrogation laser. 3D images are formed from the detected signals using a time-reversal image reconstruction algorithm. The system has been characterized in terms of its PSF, noise-equivalent pressure and field of view. Finally, the high resolution 3D imaging capability has been demonstrated using arbitrary shaped phantoms and duck embryo

    Some Like It Hot: Linking Diffuse X-ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies

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    We present an analysis of the diffuse X-ray emission in 19 compact groups of galaxies (CGs) observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in LX−TL_X-T and LX−σL_X-\sigma, even in CGs where the hot gas is associated with only the brightest galaxy. Using Spitzer photometry, we compute stellar masses and classify HCGs 19, 22, 40, and 42 and RSCGs 32, 44, and 86 as fossil groups using a new definition for fossil systems that includes a broader range of masses. We find that CGs with total stellar and HI masses ≳1011.3\gtrsim10^{11.3} M⊙_\odot are often X-ray luminous, while lower-mass CGs only sometimes exhibit faint, localized X-ray emission. Additionally, we compare the diffuse X-ray luminosity against both the total UV and 24 μ\mum star formation rates of each CG and optical colors of the most massive galaxy in each of the CGs. The most X-ray luminous CGs have the lowest star formation rates, likely because there is no cold gas available for star formation, either because the majority of the baryons in these CGs are in stars or the X-ray halo, or due to gas stripping from the galaxies in CGs with hot halos. Finally, the optical colors that trace recent star formation histories of the most massive group galaxies do not correlate with the X-ray luminosities of the CGs, indicating that perhaps the current state of the X-ray halos is independent of the recent history of stellar mass assembly in the most massive galaxies.Comment: 20 pages, 7 figures, accepted for publication in Ap
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