330 research outputs found

    Mitigating Selective Filtering’s Polarizing Effect on Web 2.0 Content

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    For almost two decades, the Internet and related technologies have made more information available to information usersthan they can handle. The decentralization of content creation that is a feature of Web 2.0 has only exacerbated this problem.This state of overload, combined with our tendency toward hypothesis-confirming behavior, can result in biased informationselection, and threatens both civil discourse and effective decision-making. In this paper, we describe a study of a techniquedesigned to mitigate filtering by enabling content consumers to see a greater diversity of information. The results of ourexperiment support the notion that the strength of people’s opinions can be changed by reading relevant information, butprovide only weak support for the effectiveness of categorizing information content. We discuss how the results will guideour future research and inform theory and practice

    Designing a Prototype for Analytical Model Selection and Execution to Support Self-Service BI

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    This paper presents a prototype of a modeling tool specifically designed for business analysts with little modeling experience. The proposed tool has an interactive user interface for a dimensional data store that contains a library of analytical models that business analysts can evaluate and use to create models they can run on their own data sets. Using a design science approach, we review the relevant literature in self-efficacy and feedforward to provide a kernel theory that informs the design criteria met by our proof of concept prototype. Specifically, we demonstrate the prototype’s user interface with a prediction problem faced by the United States Department of Labor

    Lipid apheresis techniques: current status in Germany

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    For long-term lipid apheresis therapy, several different technical systems have been developed which enable effective reduction of LDL cholesterol and other atherogenic lipoproteins, such as Lp(a), with sufficient selectivity and good clinical tolerance. Suitable techniques include whole blood adsorption with polyacrylamide and dextran sulfate cellulose, while primary plasma separation is used for cascade filtration, heparin-induced precipitation, immunoadsorption, silicate gel adsorption, and dextran sulfate cellulose (both techniques)

    Diagnostic relevance of spatial orientation for vascular dementia: A case study

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    Background: Spatial orientation is emerging as an early and reliable cognitive biomarker of Alzheimer’s disease (AD) pathophysiology. However, no evidence exists as to whether spatial orientation is also affected in vascular dementia (VaD). Objective: To examine allocentric (map-based) and egocentric (viewpoint-based) spatial orientation in an early stage VaD case. Methods: A spatial test battery was administered following clinical and neuropsychological cognitive evaluation. Results: Despite the patient’s complaints, little evidence of episodic memory deficits were detected when cueing was provided to overcome executive dysfunction. Similarly, medial temporal lobe-mediated allocentric orientation was intact. By contrast, medial parietal-mediated egocentric orientation was impaired, despite normal performance on standard visuospatial tasks. Conclusion: To our knowledge, this is the first in-depth investigation of spatial orientation deficits in VaD. Isolated egocentric deficits were observed. This differs from AD orientation deficits which encompass both allocentric and egocentric orientation deficits. A combination of egocentric orientation and executive function tests could serve as a promising cognitive marker for VaD pathophysiology

    Proton spectroscopic imaging of brain metabolites in basal ganglia of healthy older adults

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    Object: We sought to measure brain metabolite levels in healthy older people. Materials and methods: Spectroscopic imaging at the level of the basal ganglia was applied in 40 participants aged 73–74 years. Levels of the metabolites N-acetyl aspartate (NAA), choline, and creatine were determined in "institutional units" (IU) corrected for T1 and T2 relaxation effects. Structural imaging enabled determination of grey matter (GM), white matter (WM), and cerebrospinal fluid content. ANOVA analysis was carried out for voxels satisfying quality criteria. Results: Creatine levels were greater in GM than WM (57 vs. 44 IU, p < 0.001), whereas choline and NAA levels were greater in WM than GM [13 vs. 10 IU (p < 0.001) and 76 versus 70 IU (p = 0.03), respectively]. The ratio of NAA/cre was greater in WM than GM (2.1 vs. 1.4, p = 0.001) as was that of cho/cre (0.32 vs. 0.16, p < 0.001). A low voxel yield was due to brain atrophy and the difficulties of shimming over an extended region of brain. Conclusion: This study addresses the current lack of information on brain metabolite levels in older adults. The normal features of ageing result in a substantial loss of reliable voxels and should be taken into account when planning studies. Improvements in shimming are also required before the methods can be applied more widely

    Perfusion by Arterial Spin Labelling following Single Dose Tadalafil in Small Vessel Disease (PASTIS): study protocol for a randomized controlled trial

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    Background Cerebral small vessel disease is a common cause of vascular cognitive impairment in older people, with no licensed treatment. Cerebral blood flow is reduced in small vessel disease. Tadalafil is a widely prescribed phosphodiesterase-5 inhibitor that increases blood flow in other vascular territories. The aim of this trial is to test the hypothesis that tadalafil increases cerebral blood flow in older people with small vessel disease. Methods/design Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS) is a phase II randomised double-blind crossover trial. In two visits, 7-30 days apart, participants undergo arterial spin labelling to measure cerebral blood flow and a battery of cognitive tests, pre- and post-dosing with oral tadalafil (20 mg) or placebo. Sample size: 54 participants are required to detect a 15% increase in cerebral blood flow in subcortical white matter (p < 0.05, 90% power). Primary outcomes are cerebral blood flow in subcortical white matter and deep grey nuclei. Secondary outcomes are cortical grey matter cerebral blood flow and performance on cognitive tests (reaction time, information processing speed, digit span forwards and backwards, semantic fluency). Discussion Recruitment started on 4th September 2015 and 36 participants have completed to date (19th April 2017). No serious adverse events have occurred. All participants have been recruited from one centre, St George’s University Hospitals NHS Foundation Trust. Trial registration European Union Clinical Trials Register: EudraCT number 2015-001235-20. Registered on 13 May 2015
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