90 research outputs found

    Commercial vehicle tour data collection using passive GPS technology: Issues and potential applications

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    In mid-2006 a GPS survey of commercial vehicles was piloted in Melbourne, Australia to support a major update of freight data and modelling capabilities in the metropolitan region. This survey marked the first of its kind in Australia, and to the best of the authors’ knowledge, one of the first world-wide. This paper presents the issues surrounding the collection and use of GPS data as a method to provide information on commercial vehicle tours within an urban setting. The paper focuses on passive GPS methods where the truck driver’s involvement in the data collection effort is minimal. We address (a) implementation issues with the data collection, (b) the algorithms used to process the raw GPS data into meaningful trip tour information, (c) pilot survey data tour results, and (d) potential uses and limitations of passive GPS technology in urban freight modelling and planning. Despite processing challenges, GPS provides an appealing method to enrich commercial vehicle data collection and enhance our understanding of on-road behaviour. As increasing numbers of commercial vehicles become equipped with GPS receivers, we argue only privacy concerns remain as a major barrier to gathering and using such data on a wide-spread basis in the future

    Predictors of adverse prognosis in COVID-19: A systematic review and meta-analysis

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    Background: Identification of reliable outcome predictors in coronavirus disease 2019 (COVID-19) is of paramount importance for improving patient's management. Methods: A systematic review of literature was conducted until 24 April 2020. From 6843 articles, 49 studies were selected for a pooled assessment; cumulative statistics for age and sex were retrieved in 587 790 and 602 234 cases. Two endpoints were defined: (a) a composite outcome including death, severe presentation, hospitalization in the intensive care unit (ICU) and/or mechanical ventilation; and (b) in-hospital mortality. We extracted numeric data on patients’ characteristics and cases with adverse outcomes and employed inverse variance random-effects models to derive pooled estimates. Results: We identified 18 and 12 factors associated with the composite endpoint and death, respectively. Among those, a history of CVD (odds ratio (OR) = 3.15, 95% confidence intervals (CIs) 2.26-4.41), acute cardiac (OR = 10.58, 5.00-22.40) or kidney (OR = 5.13, 1.78-14.83) injury, increased procalcitonin (OR = 4.8, 2.034-11.31) or D-dimer (OR = 3.7, 1.74-7.89), and thrombocytopenia (OR = 6.23, 1.031-37.67) conveyed the highest odds for the adverse composite endpoint. Advanced age, male sex, cardiovascular comorbidities, acute cardiac or kidney injury, lymphocytopenia and D-dimer conferred an increased risk of in-hospital death. With respect to the treatment of the acute phase, therapy with steroids was associated with the adverse composite endpoint (OR = 3.61, 95% CI 1.934-6.73), but not with mortality. Conclusions: Advanced age, comorbidities, abnormal inflammatory and organ injury circulating biomarkers captured patients with an adverse clinical outcome. Clinical history and laboratory profile may then help identify patients with a higher risk of in-hospital mortality

    Effective Study: Development and Application of a Question-Driven, Time-Effective Cardiac Magnetic Resonance Scanning Protocol

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    BACKGROUND: Long scanning times impede cardiac magnetic resonance (CMR) clinical uptake. A “one‐size‐fits‐all” shortened, focused protocol (eg, only function and late‐gadolinium enhancement) reduces scanning time and costs, but provides less information. We developed 2 question‐driven CMR and stress‐CMR protocols, including tailored advanced tissue characterization, and tested their effectiveness in reducing scanning time while retaining the diagnostic performances of standard protocols. METHODS AND RESULTS: Eighty three consecutive patients with cardiomyopathy or ischemic heart disease underwent the tailored CMR. Each scan consisted of standard cines, late‐gadolinium enhancement imaging, native T1‐mapping, and extracellular volume. Fat/edema modules, right ventricle cine, and in‐line quantitative perfusion mapping were performed as clinically required. Workflow was optimized to avoid gaps. Time target was 30% (CMR: from 42±8 to 28±6 minutes; stress‐CMR: from 50±10 to 34±6 minutes, both P45% of cases. Quality grading was similar between the 2 protocols. Tailored protocols did not require additional staff. CONCLUSIONS: Tailored CMR and stress‐CMR protocols including advanced tissue characterization are accurate and time‐effective for cardiomyopathies and ischemic heart diseas

    Atrial functional tricuspid regurgitation: a novel and underappreciated clinical entity

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    Abstract Functional or secondary tricuspid regurgitation (FTR) is a progressive disease with a significant negative impact on patient morbidity and mortality. Recently, atrial fibrillation (AF) has been recognized as a cause of FTR (with/without coexisting functional mitral regurgitation) by promoting right atrial (RA) remodeling and secondary tricuspid valve (TV) annulus dilation, even in the absence of right ventricular (RV) dilation or dysfunction. This distinct form of FTR has been called "atriogenic" or "atrial". Recent evidence suggests that the RA is an important player in FTR pathophysiology not only for patients with AF, but also for those in sinus rhythm. Preliminary reports on atrial FTR show that cardioversion with documented maintenance of sinus rhythm promotes TV annulus and RA reverse remodeling and may significantly reduce FTR severity at follow-up. Large-scale studies on the prognostic benefits of rhythm vs rate-control strategy in atrial FTR patients are needed to substantiate specific guidelines indications for this subset of patients

    Pricing in Dynamic Vehicle Routing Problems

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    The perception of visible speech: estimation of speech rate and detection of time reversals

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    Four experiments investigated the perception of visible speech. Experiment 1 addressed the perception of speech rate. Observers were shown video-clips of the lower face of actors speaking at their spontaneous rate. Then, they were shown muted versions of the video-clips, which were either accelerated or decelerated. The task (scaling) was to compare visually the speech rate of the stimulus to the spontaneous rate of the actor being shown. Rate estimates were accurate when the video-clips were shown in the normal direction (forward mode). In contrast, speech rate was underestimated when the video-clips were shown in reverse (backward mode). Experiments 2-4 (2AFC) investigated how accurately one discriminates forward and backward speech movements. Unlike in Experiment 1, observers were never exposed to the sound track of the video-clips. Performance was well above chance when playback mode was crossed with rate modulation, and the number of repetitions of the stimuli allowed some amount of speechreading to take place in forward mode (Experiment 2). In Experiment 3, speechreading was made much more difficult by using a different and larger set of muted video-clips. Yet, accuracy decreased only slightly with respect to Experiment 2. Thus, kinematic rather then speechreading cues are most important for discriminating movement direction. Performance worsened, but remained above chance level when the same stimuli of Experiment 3 were rotated upside down (Experiment 4). We argue that the results are in keeping with the hypothesis that visual perception taps into implicit motor competence. Thus, lawful instances of biological movements (forward stimuli) are processed differently from backward stimuli representing movements that the observer cannot perform
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