1,499 research outputs found

    Magnetic resonance imaging of myocardial strain after acute ST-segment-elevation myocardial infarction: a systematic review

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    The purpose of this systematic review is to provide a clinically relevant, disease-based perspective on myocardial strain imaging in patients with acute myocardial infarction or stable ischemic heart disease. Cardiac magnetic resonance imaging uniquely integrates myocardial function with pathology. Therefore, this review focuses on strain imaging with cardiac magnetic resonance. We have specifically considered the relationships between left ventricular (LV) strain, infarct pathologies, and their associations with prognosis. A comprehensive literature review was conducted in accordance with the PRISMA guidelines. Publications were identified that (1) described the relationship between strain and infarct pathologies, (2) assessed the relationship between strain and subsequent LV outcomes, and (3) assessed the relationship between strain and health outcomes. In patients with acute myocardial infarction, circumferential strain predicts the recovery of LV systolic function in the longer term. The prognostic value of longitudinal strain is less certain. Strain differentiates between infarcted versus noninfarcted myocardium, even in patients with stable ischemic heart disease with preserved LV ejection fraction. Strain recovery is impaired in infarcted segments with intramyocardial hemorrhage or microvascular obstruction. There are practical limitations to measuring strain with cardiac magnetic resonance in the acute setting, and knowledge gaps, including the lack of data showing incremental value in clinical practice. Critically, studies of cardiac magnetic resonance strain imaging in patients with ischemic heart disease have been limited by sample size and design. Strain imaging has potential as a tool to assess for early or subclinical changes in LV function, and strain is now being included as a surrogate measure of outcome in therapeutic trials

    Algorithm- Versus Human-Generated Academic Plans: Determining Optimality from Community College Articulation Agreements

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    We developed a low-fidelity prototype of a report that contains an algorithmically-generated optimal academic plan. Optimal is defined as the minimal set of community college courses that satisfy the transfer requirements for multiple universities a student is preparing to apply to. We recruited 24 California community college transfer students to participate in a research session, consisting of an experiment, survey, and interview. We experimentally compared the prototype to ASSIST, California's official statewide database of articulation agreement reports. Compared to students who used the prototype, students assigned to use ASSIST reports to manually create an optimal academic plan underperformed in optimality mistakes, time required, and usability scores. Moving to our non-experimental results, a sizable minority of students had a negative assessment of counselors' ability and willingness to manually create optimal academic plans using ASSIST. Our last results revolved around students' recommendations for supplemental software features to improve the optimization prototype

    The FTC, IP, and SSOs: Government Hold-Up Replacing Private Coordination

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    In its recent report entitled “The Evolving IP Marketplace,” the Federal Trade Commission (FTC) advances a far-reaching regulatory approach (Proposal) whose likely effect would be to distort the operation of the intellectual property (IP) marketplace in ways that will hamper the innovation and commercialization of new technologies. The gist of the FTC Proposal is to rely on highly non-standard and misguided definitions of economic terms of art such as “ex ante” and “hold-up,” while urging new inefficient rules for calculating damages for patent infringement. Stripped of the technicalities, the FTC Proposal would so reduce the costs of infringement by downstream users that the rate of infringement would unduly increase, as potential infringers find it in their interest to abandon the voluntary market in favor of a more attractive system of judicial pricing. As the number of nonmarket transactions increases, the courts will play an ever larger role in deciding the terms on which the patents of one party may be used by another party. The adverse effects of this new trend will do more than reduce the incentives for innovation; it will upset the current set of well-functioning private coordination activities in the IP marketplace that are needed to accomplish the commercialization of new technologies. Such a trend would seriously undermine capital formation, job growth, competition, and the consumer welfare the FTC seeks to promote. In this paper, we examine how these consequences play out in the context of standard-setting organizations (SSOs), whose activities are key to bringing standardized technologies to market. If the FTC’s proposed definitions of “reasonable royalties” and “incremental damages” become the rules for calculating damages in patent infringement cases, the stage will be set to allow the FTC and private actors to attack, after the fact, all standard pricing methods through some combination of antitrust litigation or direct regulation on the ground that such time-honored royalty arrangements involve the use of monopoly power by patent licensors. In consequence, the FTC’s Proposal, if adopted, could well encourage potential licensees to adopt the very holdout strategies the FTC purports to address and that well-organized SSOs routinely counteract today. Simply put, the FTC’s proposal for regulating IP by limiting the freedom of SSOs to set their own terms would replace private coordination with government hold-up. The FTC should instead abandon its preliminary recommendations and support the current set of licensing tools that have fueled effective innovation and dissemination in the IP marketplace. FTC forbearance from its unwise Proposal will improve bargaining incentives, reduce administrative costs, and remove unnecessary elements of legal uncertainty in the IP system, thereby allowing effective marketplace transactions to advance consumer welfare

    New Frontiers of Quantified Self 3: Exploring Understudied Categories of Users

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    Quantified Self (QS) field needs to start thinking of how situated needs may affect the use of self-tracking technologies. In this workshop we will focus on the idiosyncrasies of specific categories of users

    Revisiting Piggyback Prototyping: Examining Benefits and Tradeoffs in Extending Existing Social Computing Systems

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    The CSCW community has a history of designing, implementing, and evaluating novel social interactions in technology, but the process requires significant technical effort for uncertain value. We discuss the opportunities and applications of "piggyback prototyping", building and evaluating new ideas for social computing on top of existing ones, expanding on its potential to contribute design recommendations. Drawing on about 50 papers which use the method, we critically examine the intellectual and technical benefits it provides, such as ecological validity and leveraging well-tested features, as well as research-product and ethical tensions it imposes, such as limits to customization and violation of participant privacy. We discuss considerations for future researchers deciding whether to use piggyback prototyping and point to new research agendas which can reduce the burden of implementing the method.Comment: To appear at the 25th ACM Conference On Computer-Supported Cooperative Work And Social Computing (CSCW '22

    Mapping right ventricular myocardial mechanics using 3D cine DENSE cardiovascular magnetic resonance

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    <p>Abstract</p> <p>Background</p> <p>The mechanics of the right ventricle (RV) are not well understood as studies of the RV have been limited. This is, in part, due to the RV's thin wall, asymmetric geometry and irregular motion. However, the RV plays an important role in cardiovascular function. This study aims to describe the complex mechanics of the healthy RV using three dimensional (3D) cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR).</p> <p>Methods</p> <p>Whole heart 3D cine DENSE data were acquired from five healthy volunteers. Tailored post-processing algorithms for RV mid-wall tissue tracking and strain estimation are presented. A method for sub-dividing the RV into four regions according to anatomical land marks is proposed, and the temporal evolution of strain was assessed in these regions.</p> <p>Results</p> <p>The 3D cine DENSE tissue tracking methods successfully capture the motion and deformation of the RV at a high spatial resolution in all volunteers. The regional Lagrangian peak surface strain and time to peak values correspond with previous studies using myocardial tagging, DENSE and strain encoded CMR. The inflow region consistently displays lower peak strains than the apical and outflow regions, and the time to peak strains suggest RV mechanical activation in the following order: inflow, outflow, mid, then apex.</p> <p>Conclusions</p> <p>Model-free techniques have been developed to study the myocardial mechanics of the RV at a high spatial resolution using 3D cine DENSE CMR. The consistency of the regional RV strain patterns across healthy subjects is encouraging and the techniques may have clinical utility in assessing disrupted RV mechanics in the diseased heart.</p

    The impact of changing guidelines on prostate cancer screening in a population-based setting, 2000-2014

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    Introduction: This study evaluates the potential impact of the publication of conflicting prostate cancer (PCa) screening trial results in 2009 and changes to the US Preventive Services Task Force (USPSTF) guidelines to recommend against screening in 2012 on temporal trends in PSA testing at two participating sites in the NCI-funded Cancer Research Network. Methods: Study participants were men aged 40-80 without a history of PCa who sought care at Fallon Health (Worcester, MA) or Henry Ford Health System (Detroit, MI) between 2000-2014. We used health claims and electronic health record data to identify men who underwent PSA testing per calendar year. We also examined trends in PSA testing among high-risk men (African-American, family history of PCa). Testing rates were compared between 2000-2008, 2009-2012, and 2013-2014. Results: From a population of 279,350 eligible men, 133,038 (48%) had at least one PSA test during the study period. Mean age at PSA test was 57 years, which increased over time at both sites. Overall, PSA testing rates rose between 2000-2008 (27-32% of eligible men per year), but declined between 2009-2012 (25% of eligible men). Testing rates declined further in 2013-2014 (23% of eligible men). We observed similar rates of decline in testing for men aged 55-69 and those aged ≄70. High-risk men were less likely to be screened across all time periods, although data was limited. Conclusions: This analysis of two population-based electronic health datasets provides evidence of a recent decrease in PSA testing, following an increase in the early 2000s. Although we are unable to determine causality, it is plausible that results of recent screening trials and/or changes to the USPSTF guidelines have impacted PSA testing practices over the past 14 years
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