302 research outputs found

    Business Aspects of Cardiovascular Computed Tomography: Tackling the Challenges

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    The purpose of this article is to provide a comprehensive understanding of the business issues surrounding provision of dedicated cardiovascular computed tomographic imaging. Some of the challenges include high up-front costs, current low utilization relative to scanner capability, and inadequate payments. Cardiovascular computed tomographic imaging is a valuable clinical modality that should be offered by cardiovascular centers-of-excellence. With careful consideration of the business aspects, moderate-to-large size cardiology programs should be able to implement an economically viable cardiovascular computed tomographic service

    Exploring and Describing the Spatial and Temporal Dynamics of Medusahead in the Channeled Scablands of Eastern Washington Using Remote Sensing Techniques

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    Medusahead is a harmful weed that is invading public lands in the West. The invasion is a serious concern to the public because it can reduce forage for livestock and wildlife, increase fire frequency, alter important ecosystem cycles (like water), reduce recreational activities, and produce landscapes that are aesthetically unpleasing. Invasions can drive up costs that generally require taxpayer’s dollars. Medusahead seedlings typically spread to new areas by attaching itself to passing objects (e.g. vehicles, animals, clothing) where it can quickly begin to affect plants communities. To be effective, management plans need to be sustainable, informed, and considerate to invasion levels across large landscapes. Ecological remote sensing analysis is a method that uses airborne imagery, taken from drones, aircrafts, or satellites, to gather information about ecological systems. This Thesis strived to use remote sensing techniques to identify medusahead in the landscape and its changes through time. This was done for an extensive area of rangelands in the Channel Scabland region of eastern ashington. This Thesis provided results that would benefit land managers that include: 1) a dispersal map of medusahead, 2) a time line of medusahead cover through time, 3) “high risk’ dispersal areas, 4) climatic factors showing an influence on the time line of medusahead, 5) a strategy map that can be utilized by land managers to direct management needs. This Thesis shows how remote sensing applications can be used to detect medusahead in the landscape and understand its invasiveness through time. This information can help create sustainable and effective management plans so land managers can continue to protect and improve western public lands threatened by the invasion of medusahead

    708-4 Can the Results of SPECT Scintigraphy Safely Guide Clinical Management of Patients with Active CAD?

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    Myocardial perfusion scintigraphy is increasingly used to categorize risk in pts with known or a high likelihood of CAD. This strategy will only be cost-effective if: 1) cardiologists will largely reserve further testing such as angiography (angio) to high-risk subsets; and 2) it is shown that less severe patterns of abnormality can be safely managed medically. We previously reported angio rates after all 4, 162 SPECT studies (excluding those with angio within 90 days beforeSPECT) at our cardiology practice-based nuclear lab: 4% (69/1663) in pts with fixed defects only and/or no ischemia; 60% (682/1141) in pts with high-risk ischemia (2 of multivessel or LAD distribution ischemia and abnormal lung uptake); and 9% (123/1352) for pts with mild-moderate ischemia. In this study, we determined outcome of the 1229 pts with mild-moderate ischemia who did not have referral for angio. Patient characteristics: mean age 65 yrs; known CAD=1061 (86%); prior CABG=344; prior MI=575; prior PTCA=674; angina=592. Twenty-eight (2%) pts were lost to follow-up. The remainder were followed for a mean of 18 months. There were 22 hard events (MI=15; cardiac death=71) (1.8%) and 54 pts required PTCA or CABG (total event rate 6.3%). Mean time to any event was 13.2 months from SPECT. Freedom from hard events at 1 yr was 99% and at 2 yrs 97%. Freedom from any event was 97% at 1 yr and 91% at 2 yrs.Conclusions1) SPECT can be a highly effective strategy for selecting pts for angio; 2) Even in a self-referral setting angio is largely reserved for pts with high-risk scans; and 3) Pts with mildly-moderately abnormal scans can be treated safely with medical therapy and close follow-u

    Further Research on the Electrification of Pyrocumulus Clouds

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    Past research on pyrocumulus electrification has demonstrated that a variety of lightning types can occur, including cloudtoground (CG) flashes, sometimes of dominant positive polarity, as well as small intracloud (IC) discharges in the upper levels of the pyrocloud. In Colorado during summer 2012, the first combined polarimetric radar, multiDoppler radar, and threedimensional lightning mapping array (LMA) observations of lightningproducing pyrocumulus were obtained. These observations suggested that the National Lightning Detection Network (NLDN) was not sensitive enough to detect the small IC flashes that appear to be the dominant mode of lightning in these clouds. However, after an upgrade to the network in late 2012, the NLDN began detecting some of this pyrocumulus lightning. Multiple pyrocumulus clouds documented by the University of Wisconsin for various fires in 2013 and 2014 (including over the Rim, West Fork Complex, Yarnell Hill, Hardluck, and several other incidents) are examined and reported on here. This study exploits the increasedsensitivity NLDN as well as the new nationwide U.S. network of polarimetric Nextgeneration Radars (NEXRADs). These observations document the common occurrence of a polarimetric "dirty ice" signature modest reflectivities (2040+ dBZ), nearzero differential reflectivity, and reduced correlation coefficient (less than 0.9) prior to the production of lightning. This signature is indicative of a mixture of ash and ice particles in the upper levels of the pyrocloud (less than 20 C), with the ice interpreted as being necessary for pyrocloud electrification. PseudoGeostationary Lightning Mapper (GLM) data will be produced from the 2012 LMA observations, and the ability of GLM to detect small pyrocumulus ICs will be assessed. The utility of lightning and polarimetric radar for documenting rapid wildfire growth, as well as for documenting pyrocumulus impacts on the composition of the upper troposphere/lower stratosphere (UTLS), will be discussed

    Significant changes in the skin microbiome mediated by the sport of roller derby

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    Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people

    Ineffectiveness of colchicine for the prevention of restenosis after coronary angioplasty

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    AbstractColchicine, an antimitogenic agent, has shown promise in preventing restenosis after coronary angioplasty in experimental animal models. A prospective trial was conducted involving 197 patients randomized in a 2:1 fashion to treatment with oral colchicine, 0.6 mg twice daily (130 patients), or placebo (67 patients) for 6 months after elective coronary angioplasty. Treatment in all patients began between 12 h before angioplasty and 24 h after angioplasty. Compliance monitoring revealed that 96% of all prescribed pills were ingested. Demographic characteristics were similar in colchicine- and placebo-treated groups. A mean of 2.7 lesions/patient were dilated. Side effects resulted in a 6.9% dropout rate in the colchicine-treated patients.Complete quantitative angiographic follow-up was obtained in 145 patients (74%) with 393 dilated lesions. Quantitative angiographic measurements were obtained in two orthogonal views at baseline before angioplasty and immediately and at 6 months after angioplasty. The quantitative mean lumen diameter stenosis before angioplasty was 67% both in the 152 lesions in the placebo-treated group and in the 241 lesions in the colchkine-treated group; this value was reduced to 24% immediately after angio-plasty in the lesions in both treatment groups.At the 6-month angiogram, lesions had restenosed to 47% lumen diameter narrowing in the placebo-treated group compared with 46% in the colchicine-treated group (p = NS). Forty-one percent of colchicine-treated patients developed restenosis in at least one lesion compared with 45% of the placebo-treated group (p = NS). In conclusion, colchicine was ineffective for preventing restenosis after coronary angioplasty

    Characterization and Failure Analysis of Solid-State Diffusion Bonded Ceramic-to-Metal Transitions

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    Reliable, high-temperature, high-pressure transitions between ceramic heat exchangers and metal components enable higher efficiency in advanced power generation systems. Recent development of a novel cermet-filled seal ring design has shown potential to maintain a gas-tight seal through multiple thermal cycles up to 800­ ÂșC. Materials characterization and computational modeling provided insight to chemical behavior (i.e., solid-state diffusion) and mechanical integrity (i.e., stress) in the seal components. Results demonstrate a correlation between machining tolerance, assembly process, and diffusion behavior on the seal’s performance in ceramic-to-metal systems and helped guide the design efficacy of future seals

    The relationship between web enjoyment and student perceptions and learning using a web-based tutorial

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    Web enjoyment has been regarded as a component of system experience. However, there has been little targeted research considering the role of web enjoyment alone in student learning using web-based systems. To address this gap, this study aims to examine the influence of web enjoyment on learning performance and perceptions by controlling system experience as a variable in the study. 74 students participated in the study, using a web-based tutorial covering subject matter in the area of 'Computation and algorithms'. Their learning performance was assessed with a pre-test and a post-test and their learning perceptions were evaluated with a questionnaire. The results indicated that there are positive relationships between the levels of web enjoyment and perceived usefulness and non-linear navigation for users with similar, significant levels of system experience. The implications of these findings in relation to web-based learning are explored and ways in which the needs of students who report different levels of web enjoyment might be met are discussed
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