Pedelecs (e-bikes), which facilitate higher speeds with less effort in comparison to traditional bicycles (t-bikes), have grown considerably in popularity in recent years. Despite the large expansion of this new transportation mode, little is known about the behavior of e-cyclists, or whether cycling an e-bike increases crash risk and the likelihood of conflicts with other road users, compared to cycling on t-bikes. In order to support the design of safety measures and to maximize the benefits of e-bike use, it is critical to investigate the real-world behavior of riders as a result of switching from t-bikes to e-bikes.Naturalistic studies provide an unequaled method for investigating rider cycling behavior and bicycle kinematics in the real world in which the cyclist regularly experiences traffic conflicts and may need to perform avoidance maneuvers, such as hard braking, to avoid crashing. In this paper we investigate cycling kinematics and braking events from naturalistic data to determine the extent to which cyclist behavior changes as a result of transferring from t-bikes to e-bikes, and whether such change influences cycling safety.Data from the BikeSAFE and E-bikeSAFE naturalistic studies were used in this investigation to evaluate possible changes in the behavior of six cyclists riding t-bikes in the first study and e-bikes in the second one. Individual cyclists’ kinematics were compared between bicycle types. In addition, a total of 5092 braking events were automatically extracted after identification of dynamic triggers. The 286 harshest braking events (136 cases for t-bike and 150 for e-bike) were then validated and coded via video inspection.Results revealed that each of the cyclists rode faster on the e-bike than on the t-bike, increasing his/her average speed by 2.9–5.0 km/h. Riding an e-bike also increased the probability to unexpectedly have to brake hard (odds ratio = 1.72). In addition, the risk of confronting abrupt braking and sharp deceleration were higher when riding an e-bike than when riding a t-bike.Our findings provide evidence that cyclists’ behavior and the way cyclists interact with other road users change when cyclists switch from t-bikes to e-bikes. Because of the higher velocity, when on e-bikes, cyclists appear to have harder time predicting movements within the traffic environment and, as a result, they need to brake abruptly more often to avoid collisions, compared with cycling on t-bikes. This study provides new insights into the potential impact on safety that a cycling society moving to e-bikes may have, indicating that e-cycling requires more reactive maneuvers than does cycling traditional bicycles and suggesting that any distractive activity may be more critical when riding e-bikes compared to traditional bikes. 相似文献
Are citizens more likely to vote when they are asked to make plans about how they will cast their ballots? Such planning—typically described as “implementation intentions”—has been shown to increase many types of desirable behaviors, including exercising and healthy eating, receiving vaccinations, physical rehabilitation, and recycling. Important earlier work in political science suggests voter turnout can also be influenced by implementation intention interventions, whereby electors are prompted to “make a plan” to vote (Nickerson & Rogers, 2010 ), though this finding has gone largely unreplicated. At the same time, elections management bodies (EMBs) in many contexts regularly conduct informational campaigns in the period leading up to elections, though little is known about the effects of such efforts upon turnout. Using data from an online experiment conducted at the time of the 2015 Canadian Federal Election, we demonstrate that implementation intention interventions can improve voter turnout but that this effect is conditional upon electors being exposed to informational materials about how to vote in the election. When survey respondents were provided with information on voting requirements and methods, and then prompted with questions forcing them to contemplate the act of casting their ballots, we observe a sizable increase in turnout rates. 相似文献
The purpose of this longitudinal study is to examine the relationship between teen sexting and offline sexual behavior. Using a sample of 1134 Czech adolescents aged 10–18 (Mage = 13.84, SD = 1.94, girls = 58.8%) from 55 schools, the latent growth model of offline sexual behavior with sexting as a time-varying covariate was employed. Participants differed at baseline for offline sexual behavior at both individual and school levels, and they varied in the growth rate of offline sexual behavior at the individual level. Only age and sensation seeking explained the variability at baseline of offline sexual behavior. The positive association between sexting and offline sexual behavior was not constant across time. However, sexting at baseline predicted offline sexual behavior a half year and one year later. Sexting may be treated as a precursor of offline sexual behavior. 相似文献
Autocorrelation and partial autocorrelation, which provide a mathematical tool to understand repeating patterns in time series data, are often used to facilitate the identification of model orders of time series models (e.g., moving average and autoregressive models). Asymptotic methods for testing autocorrelation and partial autocorrelation such as the 1/T approximation method and the Bartlett's formula method may fail in finite samples and are vulnerable to non-normality. Resampling techniques such as the moving block bootstrap and the surrogate data method are competitive alternatives. In this study, we use a Monte Carlo simulation study and a real data example to compare asymptotic methods with the aforementioned resampling techniques. For each resampling technique, we consider both the percentile method and the bias-corrected and accelerated method for interval construction. Simulation results show that the surrogate data method with percentile intervals yields better performance than the other methods. An R package pautocorr is used to carry out tests evaluated in this study. 相似文献
Objective: An online intervention to improve fruit and vegetable (FV) intake examines the role of planning, outcome expectancies, self-efficacy and gender. Women are not only expected to eat more FV than men, but they are also expected to be more responsive to nutritional advice and benefit more from treatment.
Method: A two-arm digital intervention with 269 men and 395 women (Mage = 41.2, SDage = 11.45; range: 19–66 years) was conducted in Italy, Spain and Greece, followed up at three and six months, comparing a static with a dynamic, feedback-intensive platform.
Results: Linear mixed models yielded an increase in FV consumption in both the dynamic and the static intervention arms. In men, outcome expectancies were positively related to follow-up FV intake. Dietary planning interacted with self-efficacy on behavioural outcomes.
Conclusion: FV intake increased overall, and being a woman and involvement in planning facilitated behaviour change. Women seemed to be more engaged in the dynamic platform resulting in a higher amount of planning. Initial motivation, as indicated by outcome expectancies, seemed to be beneficial for men. Self-efficacious individuals benefitted from their engagement in planning, but self-efficacy did not compensate for failing to plan. 相似文献
Background: Systematic reviews now routinely assess methodological quality to gauge the validity of the included studies and of the synthesis as a whole. Although trends from higher quality studies should be clearer, it is uncertain how often meta-analyses incorporate methodological quality in models of study results either as predictors, or, more interestingly, in interactions with theoretical moderators.Objective and methods: We survey 200 meta-analyses in three health promotion domains to examine when and how meta-analyses incorporate methodological quality.Results: Although methodological quality assessments commonly appear in contemporary meta-analyses (usually as scales), they are rarely incorporated in analyses, and still more rarely analysed in interaction with theoretical determinants of the success of health promotions. The few meta-analyses (2.5%) that did include such an interaction analysis showed that moderator results remained significant in higher quality studies or were present only among higher quality studies. We describe how to model quality interactively with theoretically derived moderators and discuss strengths and weaknesses of this approach and in relation to current meta-analytic practice.Conclusions: In large literatures exhibiting heterogeneous effects, meta-analyses can incorporate methodological quality and generate conclusions that enable greater confidence not only about the substantive phenomenon but also about the role that methodological quality itself plays. 相似文献
Research in cycling safety seeks to better understand bicycle-related crashes and injuries. The present naturalistic cycling study contributes to this research by collecting data about bicyclists’ behavior and impressions of safety–critical situations, information unavailable in traditional data sources (e.g., accident databases, observational studies). Naturalistic data were collected from 16 bicyclists (8 female; M = 39.1 years, SD = 11.4 years) who rode instrumented bicycles for two weeks. Bicyclists were instructed to report all episodes in which they felt uncomfortable while riding (subjective risk perception), even if they didn’t fall. After data collection, the bicyclists were interviewed in detail regarding their self-reported safety–critical events. Environmental conditions were also recorded via video (e.g., road surface, weather). In total, 63 safety–critical events (56 non-crashes, 7 crashes) were reported by the bicyclists, mainly due to interactions with other road users – but also due to poorly maintained infrastructure. In low-visibility conditions, vehicle-bicycle and bicycle-bicycle events were the most uncomfortable for the bicyclists. Self-reported pedestrian–bicycle events primarily consisted of pedestrians starting to cross the bicycle path without looking. With one exception, all crashes found in the study belonged to poorly maintained road and infrastructure. In particular, construction work or obstacles in the bicycle path were reported as uncomfortable and annoying by the bicyclists. This study shows how naturalistic data and bicyclists’ interviews together can provide a more informative picture of safety–critical situations experienced by the bicyclist than traditional data sources can. 相似文献