Stichting Wetenschappelijk Onderzoek Verkeersveiligheid

Pyridine-2,6-dicarboxylic acid (DPA) is a valuable dicarboxylic acid that has the potential to serve as a precursor for bio-sustainable and bio-degradable materials and self-healing polymers. It also plays a crucial role in the heat resistance of Bacillus subtilis spores. However, extracting DPA from spores is resource-intensive and technically complex, limiting its industrial application. To overcome these challenges, this study aims to engineer B. subtilis as a microbial cell factory for the direct production of free and soluble DPA. This study first demonstrated that blocking sporulation reduced DPA production due to the repression of dipicolinate synthase expression. To enhance extracellular DPA production, dipicolinate synthase expression was fine-tuned, increasing the extracellular DPA titer to 330 ± 10mg/l in strain BSDYvyDVF. Transcriptomic analysis revealed that spore coat assembly genes modulate DPA production. By disrupting a spore coat assembly activator in strain BSDYvyDVF-gerE, sporulation was successfully inhibited, significantly boosting the DPA yield to 944 ± 3mg/l. Further optimization of fermentation conditions was performed using an orthogonal design. The highest DPA titer of 1250mg/l was achieved and validated through fed-batch fermentation in a 1.5-l bioreactor. This study demonstrates the potential of engineered B. subtilis BSDYvyDVF-gerE as an efficient cell factory for sustainable DPA biosynthesis. In addition, it identifies key challenges in DPA production, including synthesis efficiency (regulation of key enzyme expression) and transport (intracellular-to-extracellular export), and proposes corresponding solutions.

<strong class="journal-contentHeaderColor">Abstract.</strong> Firefighter entrapments occur when wildfires suddenly transition into extreme wildfire events (EWEs). These transitions are often caused by pyroconvective fire-atmosphere coupling, triggered by a combination of high fire intensity and atmospheric vertical thermodynamic structure. Pyroconvection indices calculated using coarse atmospheric modeling data crudely detect these dynamic transitions due to highly localized atmospheric processes and changes in atmospheric conditions caused by the fire. Consequently, fire managers may remain unaware that fire behavior intensification due to fire-atmosphere coupling is outdating the safety protocols in place. This study presents a new in-plume profiling methodology to improve the assessment of fire-atmosphere interaction dynamics in real-time. As proof of concept, we analyzed 156 in-plume sondes launched during the 2021&ndash;2025 fire seasons in Spain, Chile, Greece, and The Netherlands. As a strategy to measure the coupling fire-atmosphere, we propose simultaneously launching two radiosondes: one to measure ambient conditions and another to capture data within the plume updraft. Comparing these profiles, we measure in-situ and in-real time the modification of state variables by the fire-atmosphere interaction. These new observations and methodology improve our assessment of pyroconvection dynamics demonstrating practical implications that support their use by incident management teams. It has the potential to enhance awareness of possible near-accidents and tactical failures during extreme pyroconvective wildfire events. Additionally, it offers a comprehensive observational dataset to improve pyroconvection nowcasting and advance research on fire-atmosphere interaction.

Increasing accessibility and improving cycling safety are the primary objectives of cities and policymakers. In the literature, there are several studies examining cycling safety and few studies examining cycling accessibility. However, few studies conduct a joint examination of these two topics to understand the relationship between them. This paper aims to develop and apply a methodological framework to conduct a joint zone-based analysis of traffic safety and accessibility. The developed framework integrates route choice modelling and four-step modelling into traffic safety and accessibility analysis and the outcome is a novel zone-based crash risk estimation incorporating traffic crashes with trip characteristics (including, trip purpose, origin-destination, and alternative routes). The proposed framework was applied in a case study to examine the injury crash risk imposed on commuting cyclists and job accessibility in the city of Utrecht, the Netherlands.The results illustrate the need to embed trip characteristics into zone-based traffic safety estimation to be able to compare the spatial distribution of traffic safety with other mobility and transport-related indicators. Moreover, the findings reflect on significance of taking route choice features into account in accessibility analysis to avoid overestimating accessibility levels. They show that safety and accessibility levels are not equally distributed in the city of Utrecht. For example, low-income areas generally have lower job accessibility levels and higher cycling crash risks which imply the spatial and social inequalities in the transport system's effects.

Journal Article Police-assisted monitoring of impaired driving Get access Charles Goldenbeld, Charles Goldenbeld Researchers, Institute for Road Safety Research SWOV, the Hague, the Netherlands E-mail: charles.goldenbeld@swov.nl Search for other works by this author on: Oxford Academic Google Scholar Agnieszka Stelling, Agnieszka Stelling Researchers, Institute for Road Safety Research SWOV, the Hague, the Netherlands Search for other works by this author on: Oxford Academic Google Scholar Sander van der Kint Sander van der Kint Researchers, Institute for Road Safety Research SWOV, the Hague, the Netherlands Search for other works by this author on: Oxford Academic Google Scholar Policing: A Journal of Policy and Practice, Volume 18, 2024, paad089, https://doi.org/10.1093/police/paad089 Published: 16 January 2024

This paper presents the background, setup, and results of a stated choice experiment investigating the influence of three different intersection based innovations on cyclists' route choice decisions. Next to commonly used route attributes, the following three intersection based innovations were investigated: ‘Flo’, a bicycle speed advice tool; ‘Schwung’, a bicycle - traffic light communication tool; and ‘BikeScout’, an intersection flashing system. The generated stated choice experiment was included in an online questionnaire that was filled out by 608 respondents who evaluated in total 3648 choice tasks. The evaluations were analyzed using a Multinomial Mixed Logit model. The model estimation results show that the commonly used route attributes (travel time, type of bicycle path facility, pavement quality level, motorized traffic speed, bicycle crowdedness, and number of traffic light intersections) have the highest influence on cyclists' route choice decisions. The impact of intersection based innovations on cyclists' route choice decisions is limited.

Introduction: Sufficient cycle track width is important to prevent single-bicycle crashes and collisions between cyclists. The assumptions on which the minimum width is based in guidelines is founded on only a few studies. The aim of the present study is to investigate the relationship between cycle track width and lateral position of cyclists. Method: We conducted an experiment to evaluate the lateral position of cyclists along cycle tracks with different widths (Study 1). Participants cycled on an instrumented bicycle with a LIDAR to measure their lateral position. Five conditions were defined: cycle track width of 100 cm, 150 cm and 200 cm without interaction, and cycle track width of 150 cm and 200 cm with an oncoming cyclist simulated by a parked bicycle. The cross-sectional Study 2 is based on the collected lateral position measurements at cycle tracks with varying width reported in Dutch studies since 2010. Results: The experimental Study 1 with 24 participants shows that an increase in cycle track width causes cyclists to ride further away from the verge and keep more distance from an oncoming cyclist. The cross-sectional Study 2 was based on lateral position measured at 33 real-life Dutch cycle tracks. Study 2 yielded similar results, indicating that doubling pavement width increases lateral position by some 50%. Study 2 shows that, compared with a solo cyclist without interaction, a right-hand cyclist of a duo and a cyclist meeting an oncoming cyclist ride around 30% closer to the verge. Conclusions: The wider the cycle track, the more distance cyclists maintain from the verge. Cyclists ride closer to the verge due to oncoming cyclists. Practical applications: Given a cyclists’ lateral position while meeting, common variations between cyclists’ steering behavior, and vehicle width and circumstances, a cycle track width of 250 cm is needed for safe meeting maneuvers.