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  • Prospective associations of COVID-related stress with vaping nicotine and cannabis among high school students: Mediated by vaping susceptibility

    by Ryan Lee, Junhan Cho, Dayoung Bae, Larisa Albers, Shirin Emma Herzig, Carla Michelle Ramirez, Alberto Carvajal Jr, Daniel Soto, Jennifer B. Unger

    Adolescent e-cigarette and cannabis vaping have become significant public health concerns, with rates increasing in recent years. However, there is limited research on the impacts of COVID-related stress on adolescent vaping. This study examined the longitudinal impacts of COVID-related stress on adolescent e-cigarette and cannabis vaping, including the mediating role of vaping susceptibility (which measures a lack of a firm commitment not to use a substance). We examined the prospective associations of COVID-related stress during remote learning (2020–2021) with e-cigarette and cannabis vaping use two years later (2022–2023) through the mediation of vaping susceptibility (2021–2022) among a cohort of students recruited as ninth graders from nine public high schools across Los Angeles County and surveyed annually (N = 1,316). Higher levels of COVID-related stress were prospectively associated with increased susceptibility to vaping e-cigarettes (B = 0.04, p = .02) and cannabis (B = 0.04, p = .02) one year later, which in turn increased the odds of e-cigarette (B = 0.98, p = .003) and cannabis (B = 1.62, p < .001) vaping two years later. This study highlights the critical need for effective, school-based prevention programs to reduce susceptibility to vaping, particularly during periods of heightened stress or future crises.

  • A study on factors influencing the national carbon emission trading price in China

    by Mingzhu Liao, Feng Long, Xue Tian, Fenfen Bi, Wei Tian, Xiao Li, Chazhong Ge

    On 16 July 2021, China officially launched its national carbon emissions trading market, which has since become the largest market in the world in terms of coverage of greenhouse gas emissions and plays an important role in combating global climate change. This study selects the national carbon emissions trading price data from July 16, 2021 to August 31, 2024, which records the price fluctuation characteristics in the early stage of the market (covering only the stage of the electric power industry), which not only provides a historical reference for the subsequent inclusion of the industry, but also provides an important basis for evaluating the effectiveness of the market construction and the optimization of the policy. At the same time, the VEC model is used to study the dynamic relationship between the national carbon emission trading price and key variables, including energy prices, macroeconomic conditions, the development of the power industry, international carbon prices, carbon emissions from the power industry, and the trading volume of national carbon emission quotas. The results show that there is a long-term equilibrium relationship between the national carbon trading price and the variables, which provides a scientific basis for setting a reasonable fluctuation range of the carbon price. Furthermore, impulse response and variance decomposition analyses were conducted to evaluate the short-term dynamic effects of each variable on the national carbon emission trading price. The results reveal that the trading volume of national carbon emission quotas and the development of the power industry exert significant influence on the national carbon emission trading price. In addition, the carbon emissions of the electric power industry have a positive impact on the national carbon emissions trading price in the short-term situation, and in the long-term situation, they have a negative impact. This provides a parameter calibration basis for the expansion of the industry and a reference for policy making, which is important for the construction of the national carbon emission trading market with international influence. The marginal contributions of this study are:(1) forming a new combination of variables for a comprehensive analysis of the national carbon emissions trading market; (2) the empirical results uncover new insights into the dynamics of the national carbon price; and (3) providing empirical evidence for improving the institutional system of the national carbon emissions trading market.

  • A study on the effect of slotted airfoil on the performance of Darrieus vertical axis wind turbines in different wind regions

    by Liqi Luo, Qiuyun Mo, Yuefeng Li, Tao Jiang, Yinglei Zhao

    Slotted airfoils mitigate the flow separation on the blades operating at high angles of attack in the upwind region, consequently augmenting the power coefficient and reducing the startup wind speed of Darrieus vertical axis wind turbines (VAWTs). Nonetheless, the presence of the slot structure alters the original flow dynamics, inducing flow separation when the blade operates in the downwind region and at elevated blade tip speed ratios (TSR), which leads to a reduction in the blade’s power coefficient. This study establishes an aerodynamic model of the flow field migration around the blade surface by utilizing the lattice Boltzmann method in conjunction with large eddy simulation to ascertain the influence of the inlet and outlet positions of the slot on the flow field structure across different wind regions. The simulations indicate that, under the downwind region and at high TSR, positioning the slot at the midsection of the blade, although it expands flow separation near the trailing-edge, does not disrupt the primary flow at the leading-edge. Unexpectedly, the slot optimizes the pressure distribution on the pressure side of the blade, thereby enhancing the blade’s performance in the downwind region. At a TSR of 3.3, the average power coefficient of the blades in the downwind region increases by up to 63.62%. These results offer valuable insights for the implementation of slotted airfoils to enhance energy conversion efficiency in VAWTs’ design optimization.

  • Retraction: Role of DNA Methylation in Cell Cycle Arrest Induced by Cr (VI) in Two Cell Lines

    by The PLOS One Editors



  • Trends in collisions and traffic mortality rates in Mexico City: A comparison of six data sources

    by Martha Laura Herrera Ortiz, Carolina Pérez Ferrer, Carolina Quintero Valverde, Luis Chías Becerril, Armando Martínez Santiago, Héctor Daniel Reséndiz López, D. Alex Quistberg, Tonatiuh Barrientos Gutiérrez

    Introduction

    Improving data quality is an international recommendation to advance road safety. Mexico City has several sources of road safety data which are used interchangeably, no study has analyzed their strengths and limitations.

    Objective

    We aimed to compare the trends of four indicators (total collision rate, collision resulting in injury rate, fatality rate and mortality rate) across six open access datasets of Mexico City, between 2015–2022, and to discuss their differences, strengths and limitations.

    Materials and methods

    Datasets consulted were from: police records, emergency calls, an insurance company, the justice department, the Institute for Forensic Science and vital registrations for the period 2015–2022. We descriptively compared rates and their trends and estimated percentage changes from the start to the end of the period.

    Results

    The collision, collision resulting in injury and mortality rates varied greatly across datasets. Trends over time were consistent in direction; they showed a decline in collisions and deaths from 2015 to 2020 and an increase from 2020 to 2022. However, the magnitude of the change was very different across datasets.

    Conclusions

    None of the datasets was comprehensive enough to provide a full picture of road safety in Mexico City. Differences between datasets may be related to the methodology used to report and register collisions and to the reach and remit of each institution. Our results highlight the need for a more comprehensive data information system for road safety in Mexico City and across the country. We call on researchers, practitioners and policy makers to use available data sources responsibly and to be transparent about their limitations until we progress to a unique source of information.