12 research outputs found

    Towards game theoretic AV controllers: measuring pedestrian behaviour in Virtual Reality

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    Understanding pedestrian interaction is of great importance for autonomous vehicles (AVs). The present study investigates pedestrian behaviour during crossing scenarios with an autonomous vehicle using Virtual Reality. The self-driving car is driven by a game theoretic controller which adapts its driving style to pedestrian crossing behaviour. We found that subjects value collision avoidance about 8 times more than saving 0.02 seconds. A previous lab study found time saving to be more important than collision avoidance in a highly unrealistic board game style version of the game. The present result suggests that the VR simulation reproduces real world road-crossings better than the lab study and provides a reliable test-bed for the development of game theoretic models for AVs

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe

    Examining Pedestrian-Autonomous Vehicle Interactions in Virtual Reality

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    Autonomous vehicles now have well developed algorithms and open source software for localisation and navigation in static environments but their future interactions with other road users in mixed traffic environments, especially with pedestrians, raise some concerns. Pedestrian behaviour is complex to model and unpredictable, thus creating a big challenge for self-driving cars. This paper examines pedestrian behaviour during crossing scenarios with a game theoretic autonomous vehicle in virtual reality. In a first experiment, we recorded participants’ trajectories and found that they were crossing more cautiously in VR than in previous laboratory experiments. In two other experiments, we used a gradient descent approach to investigate participants’ preference for a certain AV driving style. We found that the majority of them were not expecting the car to stop in these scenarios. These results suggest that VR is an interesting tool for testing autonomous vehicle algorithms and for finding out about pedestrian preferences

    User Evaluation of Comfortable Deceleration Profiles for Highly Automated Driving: Findings from a Test Track Study

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    As automated vehicles advance and become more widespread, it is increasingly important to ensure optimal driving comfort for passengers. Recent research has focused on developing driving styles for automated vehicles that are perceived to be most comfortable. However, there is still little understanding if and how possible driving styles need to be adjusted for specific traffic scenarios. In this study, a total of 36 participants experienced three different deceleration profiles (a linear deceleration profile ‘One-Step’, and two versions of stepwise deceleration profiles ‘Two-Step V1 and V2’) across different driving scenarios (deceleration before curves, speed-limit, and stop sign). Deceleration profiles were rated by participants and the impact of non-driving related activities on driving comfort was investigated. Results show a positive rating for all deceleration profiles in terms of comfort. For decelerations into a stillstand at a Stop Sign, participants seem to prefer the One-Step approach which decelerates continuously. However, participants ranked the smoother Two-Step V1 approach more frequently as their personal favourite than the One-Step profile and the more dynamic Two-Step V2 profile. The visual distraction of the passenger through a non-driving activity had no impact on passenger comfort and preferences for the profiles and scenarios tested within this study. Nonetheless, participants reported perceiving a lower intensity of longitudinal vehicle movements when visually distracted during the drive. The results of the study provide recommendations for the design and implementation of deceleration profiles perceived to be comfortable

    Severe perturbations of the blood T cell repertoire in polymyositis, but not dermatomyositis patients

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    Abstract Polymyositis and dermatomyositis are diseases characterized by muscle weakness and muscle inflammatory infiltrates. Their pathogenesis remains unclear. A central role for endomysial autoaggressive CD8+ T cells is suspected in polymyositis and for perivascular B cells in dermatomyositis. We compared the T cell repertoire of 10 polymyositis and 10 dermatomyositis patients by immunoscope, a method providing a global assessment of the T cell repertoire and a sensitive detection of clonal T cell expansions. Samples were analyzed qualitatively and quantitatively in the blood (unsorted cells and CD4+ and CD8+ cells) and in muscle infiltrates. Dramatic perturbations of the T cell repertoire were observed in the blood of polymyositis but not dermatomyositis patients (p &amp;lt; 0.0005), the latter being undistinguishable from controls. These perturbations were due to oligoclonal expansions of CD8+ T cells and most blood clonal expansions were also found in muscle. These results indicate that the pathogenesis of polymyositis and dermatomyositis is different and reinforce the view that polymyositis but not dermatomyositis is an autoimmune CD8+ T cell-mediated disease. Moreover, this method may be helpful for the differential diagnosis of polymyositis and dermatomyositis and for noninvasive follow-up of polymyositis patients.</jats:p

    Prevalence of psychoactive drug use in patients hospitalized for acute cardiac events: Rationale and design of the ADDICT-ICCU trial, from the Emergency and Acute Cardiovascular Care Working Group and the National College of Cardiologists in Training of the French Society of Cardiology

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    International audienceBackground: Psychoactive drugs, including illicit drugs, are associated with an increased rate of cardiovascular events. The prevalence and outcome of patients using these drugs at the time of admission to an intensive cardiac care unit is unknown.Aim: To assess the prevalence of psychoactive drugs detected in consecutive patients hospitalized in an intensive cardiac care unit for an acute cardiovascular event.Methods: This is a nationwide prospective multicentre study, involving 39 centres throughout France, including all consecutive patients hospitalized in an intensive cardiac care unit within 2weeks. Psychoactive drug use will be assessed systematically by urine drug assay within 2hours of intensive cardiac care unit admission, to detect illicit (cannabinoids, cocaine, amphetamines, ecstasy, heroin and other opioids) and non-illicit (barbiturates, benzodiazepines, tricyclic antidepressants, methadone and buprenorphine) psychoactive drugs. Smoking will be investigated systematically by exhaled carbon monoxide measurement, and alcohol consumption using a standardized questionnaire. In-hospital major adverse events, including death, resuscitated cardiac arrest and cardiogenic shock, will be recorded. After discharge, all-cause death and major adverse cardiovascular events will be recorded systematically and adjudicated at 12months of follow-up.Results: The primary outcome will be the prevalence of psychoactive drugs detected by systematic screening among all patients hospitalized in an intensive cardiac care unit. The in-hospital major adverse events will be analysed according to the presence or absence of detected psychoactive drugs. Subgroup analysis stratified by initial clinical presentation and type of psychoactive drug will be performed.Conclusions: This is the first prospective multicentre study to assess the prevalence of psychoactive drugs detected by systematic screening in consecutive patients hospitalized for acute cardiovascular events

    Carbon monoxide and prognosis in smokers hospitalised with acute cardiac events: a multicentre, prospective cohort studyResearch in context

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    Summary: Background: Smoking cigarettes produces carbon monoxide (CO), which can reduce the oxygen-carrying capacity of the blood. We aimed to determine whether elevated expiratory CO levels would be associated with a worse prognosis in smokers presenting with acute cardiac events. Methods: From 7 to 22 April 2021, expiratory CO levels were measured in a prospective registry including all consecutive patients admitted for acute cardiac event in 39 centres throughout France. The primary outcome was 1-year all-cause death. Initial in-hospital major adverse cardiac events (MAE; death, resuscitated cardiac arrest and cardiogenic shock) were also analysed. The study was registered at ClinicalTrials.gov (NCT05063097). Findings: Among 1379 patients (63 ± 15 years, 70% men), 368 (27%) were active smokers. Expiratory CO levels were significantly raised in active smokers compared to non-smokers. A CO level >11 parts per million (ppm) found in 94 (25.5%) smokers was associated with a significant increase in death (14.9% for CO > 11 ppm vs. 2.9% for CO ≤ 11 ppm; p  11 ppm was associated with a significant increase in MAE in smokers during initial hospitalisation after adjustment for comorbidities (odds ratio [OR] 15.75, 95% CI [5.56–44.60]) or parameters of in-hospital severity (OR 10.67, 95% CI [4.06–28.04]). In the overall population, CO > 11 ppm but not smoking was associated with an increased rate of all-cause death (HR 4.03, 95% CI [2.33–6.98] and 1.66 [0.96–2.85] respectively). Interpretation: Elevated CO level is independently associated with a 6-fold increase in 1-year death and 10-fold in-hospital MAE in smokers hospitalized for acute cardiac events. Funding: Grant from Fondation Coeur &amp; Recherche
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