Increase Cycling Rates Research Articles

How Good Is Open Bicycle Network Data? A Countrywide Case Study of Denmark

Cycling is a key ingredient for a sustainability shift of Denmark's transportation system. To increase cycling rates, better bicycle infrastructure networks are required. Planning such networks requires high‐quality infrastructure data, yet the quality of bicycle infrastructure data is understudied. Here, we compare the two largest open data sets on dedicated bicycle infrastructure in Denmark, OpenStreetMap (OSM) and GeoDanmark, in a countrywide data quality assessment, asking whether the data are good enough for network‐based analysis of cycling conditions. We find that neither of the data sets is of sufficient quality, and that data conflation is necessary to obtain a more complete data set. Our analysis of the spatial variation of data quality suggests that rural areas are more prone to incomplete data. We demonstrate that the prevalent method of using infrastructure density as a proxy for data completeness is not suitable for bicycle infrastructure data, and that matching of corresponding features is thus necessary to assess data completeness. Based on our data quality assessment, we recommend strategic mapping efforts toward data completeness, consistent standards to support comparability between different data sources, and increased focus on data topology to ensure high‐quality bicycle network data.

Increased cycling rates for thick all active material electrodes via electrolyte modifications

Lithium-ion (Li-ion) batteries are the dominant energy storage technology in many applications due to high energy and power density, and research efforts continue towards further advances in their electrochemical properties. One general strategy to increase energy density at the cell level is to increase electrode thickness. However, with increased electrode thickness and loading, ionic transport becomes a limiting factor. All active material (AAM) electrodes provide a route to increase electrode thickness without inactive conductive additives and polymer binders, which results in relative ionic transport advantages due to the absence of these inactive materials in the electrode interstitial regions. AAM electrodes processed herein have mildly sintered LiFePO4 (LFP) and Li4Ti5O12 (LTO) fabricated into AAM electrodes as cathode and anode. These materials were paired and combined with electrolyte systems with solvent additives which increased electrolyte ionic conductivity. The resulting cells had high areal capacities, and the capacity achieved at increasing current density was significantly improved relative to the additive-free electrolyte which was attributed to the improved ionic conductivity with the electrolyte additives.

3161 – CELLULAR AND MOLECULAR EFFECTS OF DMPGE₂ RADIOMITIGATION IN MOUSE AND HUMAN BONE MARROW CELLS IN VIVO USING C57BL/6 AND HUMANIZED NSG MOUSE MODELS OF ACUTE RADIATION SYNDROME

The hematopoietic system is highly sensitive to radiation exposure, and bone marrow (BM) failure from the hematopoietic acute radiation syndrome (H-ARS) is the primary threat to human life following a nuclear accident or attack. Dimethyl prostaglandin E2 (dmPGE₂) is a promising medical countermeasure (MCM) which significantly increases H-ARS survival in mice. Here mechanisms of dmPGE₂ radiomitigation were defined when given 24 h post-total body irradiation (TBI) in C57BL/6 mice and in humanized NOD scid gamma null (NSG) mice. In C57BL/6 mice exposed to the LD50/30 (8.53 Gy), dmPGE₂ increased cycling rates of hematopoietic stem and progenitor cells (HSPCs) within 6h of treatment, increased total BM cellularity and viability within 24h of treatment, and accelerated peripheral blood recovery. In CD34-humanized NSG mice exposed to 1 Gy, total BM counts were depressed by 48h post-TBI, but % huCD45+ BM chimerism was increased in dmPGE₂-treated animals, suggesting a slight human cell advantage from dmPGE₂. Within the huCD45+ population, significant effects of both TBI and dmPGE₂ on various human HSPC subsets in vivo regarding frequencies, cycling, DNA damage, and gene expression were delineated, including upregulation of transcriptional activators FOS, JUNB, EGR1, and NR4A1 within both mouse and human HSCs in response to dmPGE2 radiomitigation. These proof-of-concept studies support that dmPGE₂ effects related to radiomitigation can be detected in irradiated human HSPCs in vivo in NSG mice. Further work will investigate a more radioresistant humanized mouse system to better model the radiation-damaged BM environment after lethal exposure. Overall, this work describes an innovative translational platform for testing radiation MCMs, and represents a significant step toward human translation of dmPGE₂ for this purpose. The hematopoietic system is highly sensitive to radiation exposure, and bone marrow (BM) failure from the hematopoietic acute radiation syndrome (H-ARS) is the primary threat to human life following a nuclear accident or attack. Dimethyl prostaglandin E2 (dmPGE₂) is a promising medical countermeasure (MCM) which significantly increases H-ARS survival in mice. Here mechanisms of dmPGE₂ radiomitigation were defined when given 24 h post-total body irradiation (TBI) in C57BL/6 mice and in humanized NOD scid gamma null (NSG) mice. In C57BL/6 mice exposed to the LD50/30 (8.53 Gy), dmPGE₂ increased cycling rates of hematopoietic stem and progenitor cells (HSPCs) within 6h of treatment, increased total BM cellularity and viability within 24h of treatment, and accelerated peripheral blood recovery. In CD34-humanized NSG mice exposed to 1 Gy, total BM counts were depressed by 48h post-TBI, but % huCD45+ BM chimerism was increased in dmPGE₂-treated animals, suggesting a slight human cell advantage from dmPGE₂. Within the huCD45+ population, significant effects of both TBI and dmPGE₂ on various human HSPC subsets in vivo regarding frequencies, cycling, DNA damage, and gene expression were delineated, including upregulation of transcriptional activators FOS, JUNB, EGR1, and NR4A1 within both mouse and human HSCs in response to dmPGE2 radiomitigation. These proof-of-concept studies support that dmPGE₂ effects related to radiomitigation can be detected in irradiated human HSPCs in vivo in NSG mice. Further work will investigate a more radioresistant humanized mouse system to better model the radiation-damaged BM environment after lethal exposure. Overall, this work describes an innovative translational platform for testing radiation MCMs, and represents a significant step toward human translation of dmPGE₂ for this purpose.

Dynamic river processes drive variability in particulate organic matter over fine spatiotemporal scales

Abstract We sampled freshwater suspended particulate organic matter (POM) to determine its carbon and nitrogen stable isotope composition and collected co‐located water chemistry data in California's Sacramento—San Joaquin Delta from sites on the Mokelumne and Cosumnes rivers. A 10‐km2 area was sampled across 12 sites and divided among three habitat types (i.e. riverine, slackwater/slough, and off‐channel), 34 times between November 2016 and July 2017. Here, we describe the variability in water quality and POM variables, and assess factors associated with that variability using dimensional reduction and linear modelling within the context of our habitat types. The stable isotope composition of freshwater POM and water chemistry variables differed significantly across small areas (<10 km) and short time frames (weekly). Hydrological connectivity amongst sites was found to be an important factor in the isotopic and elemental composition of POM. During periods of low hydrological connectivity, in situ dynamics were strongly associated with differentiation of POM in different habitats. Discharge (16–433 m3/s) and water temperature (8–30°C) were the variables most associated with variations in the composition of POM. Slackwater sites showed the greatest variability in POM composition, which may be symptomatic of longer water residence times, increased cycling rates of nutrients and organic matter, or a combination of the two. Variability in POM stable isotope composition demonstrates that caution should be exercised when interpreting analyses that assume a static POM stable isotope composition based on two‐end member mixing. Unconstrained variability in space or time could confound interpretations of models and data. Moving forward, conceptual and numerical models for river ecosystems that emphasise temporally heterogeneous lateral exchange amongst habitat patches should be prioritised when considering restoration efforts and monitoring outcomes.

Road lighting density and brightness linked with increased cycling rates after-dark.

Cycling has a range of benefits as is recognised by national and international policies aiming to increase cycling rates. Darkness acts as a barrier to people cycling, with fewer people cycling after-dark when seasonal and time-of-day factors are accounted for. This paper explores whether road lighting can reduce the negative impact of darkness on cycling rates. Changes in cycling rates between daylight and after-dark were quantified for 48 locations in Birmingham, United Kingdom, by calculating an odds ratio. These odds ratios were compared against two measures of road lighting at each location: 1) Density of road lighting lanterns; 2) Relative brightness as estimated from night-time aerial images. Locations with no road lighting showed a significantly greater reduction in cycling after-dark compared with locations that had some lighting. A nonlinear relationship was found between relative brightness at a location at night and the reduction in cyclists after-dark. Small initial increases in brightness resulted in large reductions in the difference between cyclist numbers in daylight and after-dark, but this effect reached a plateau as brightness increased. These results suggest only a minimal amount of lighting can promote cycling after-dark, making it an attractive mode of transport year-round.

Advancing cycling among women: An exploratory study of North American cyclists

Past studies show that women cycle at a lower rate than men due to various factors; few studies examine attitudes and perceptions of women cyclists on a large scale. This study aims to fill that gap by examining the cycling behaviors of women cyclists across multiple cities in North America. We analyzed an online survey of 1,868 women cyclists in the US and Canada, most of whom were confident when cycling. The survey recorded respondents’ cycling skills, attitude, perceptions of safety, surrounding environment, and other factors that may affect the decision to bicycle for transport and recreation. We utilized tree-based machine learning methods (e.g., bagging, random forests, boosting) to select the most common motivations and concerns of these cyclists. Then we used chi-squared and non-parametric tests to examine the differences among cyclists of different skills and those who cycled for utilitarian and non-utilitarian purposes. Tree-based model results indicated that concerns about the lack of bicycle facilities, cycling culture, cycling’s practicality, sustainability, and health were among the most important factors for women to cycle for transport or recreation. We found that very few cyclists cycled by necessity. Most cyclists, regardless of their comfort level, preferred cycling on facilities that were separated from vehicular traffic (e.g., separated bike lanes, trails). Our study suggests opportunities for designing healthy cities for women. Cities may enhance safety to increase cycling rates of women by tailoring policy prescriptions for cyclists of different skill groups who have different concerns. Strategies that were identified as beneficial across groups, such as investing in bicycle facilities and building a cycling culture in communities and at the workplace, could be useful to incorporate in long-range planning efforts.

A Comparison of Habits and Perceptions Towards Cycling in Warsaw

Background Cycling in urban environments is seen as an activity providing many environmental, social and health benefits. There is potential for significant mode shifts towards cycling in many cities, and a better understanding of enabling factors and barriers could help guide more targeted cycle-promoting policies. Eastern-European cities such as Warsaw in particular tend to have low cycling rates and to be under-studied with regards to active travel behaviour. Methods We investigated travel mode choices and perceptions of cycling through surveys administered to two groups of adult population in Warsaw between December 2012 and January 2013. One was a paper and pencil survey of a representative random sample of citizens (“random” sample), while the other was an online survey of respondents who had cycled at least once in the past 6 months (“cyclists” sample). In both surveys, respondents were classified according to their behaviour in the past 6 months as either non-cyclists (did not cycle, for random sample only) utilitarian cyclists (cycled for transport) and recreational cyclists (cycled for recreation). Socio-demographics, travel habits and perceptions of cycling were compared across the categories using the χ2 test or fisher exact test, means using one-way ANOVA and medians using the Kruskal Wallis test. Results The “cyclist” sample (N=505) consisted of 41% recreational cyclists, and 59% utilitarian cyclist (of which 84% were also recreational). Utilitarian cyclists cycled on average 35 minutes per week more than recreational cyclists. They were more likely to perceive more benefits such as rapidity and sense of freedom, while recreational cyclists were more concerned about weather conditions. In the random sample (N=563), there were 46% non-cyclist, 37% recreational, and 15% utilitarian (of which 97% were also recreational) cyclists. The results show that, in general, cyclists tended to perceive less fear of being injured, saw cycling as being cheaper and faster than other modes, believed they had the time and resources needed for bicycle maintenance, felt a sense of freedom and observed to be faster when using bike. In addition, cyclists perceived the lack of cycle lane as less of a barrier to cycling than non-cyclists. Conclusions Cycling is more typically a recreational rather than a utilitarian activity in Warsaw. People who cycle at least occasionally tend to perceive more benefits and fewer barriers to cycling than non-cyclists, and cycling for travel enhances further these beliefs. Improving infrastructure but also making benefits of cycling more salient may increase cycling rates in Warsaw.

Switching to alternative transit: combining bicycle safety improvements with parking regulations

ABSTRACTSmart growth policies advocate for economically viable, environmentally conscientious, and socially equitable solutions for urban development. These policies were developed largely in response to issues rooted in the automobile-oriented culture: air pollution, high greenhouse gas emissions, traffic congestion, and sedentary lifestyles. In urban settings, a good transportation alternative is cycling, since it is able to serve the travel needs of nearly half of city dwellers’ daily trips. Many European and Canadian cities have successfully increased cycling rates by creating safer bicycle environments and restricting or discouraging automobile use. To evaluate the potential effects of the above measures on American urban areas, this paper examines case studies of cycle tracks and bicycle boulevards implemented in American cities, and how these facility improvements have changed how safe cyclists feel on the road and overall bicycle usage. Results show the two methods are indeed effective in increasi...

Performance of Municipal Cycling Policies in Medium-Sized Cities in the Netherlands since 2000

With its high cycling mode share, the Netherlands is often seen as a best practice for cycling policies. However, there is little insight into the drivers behind this phenomenon, specifically which policy interventions increased cycling rates and which did not. The knowledge gap on the effectiveness of cycling policies seriously limits the potential for learning from the Dutch experience. This paper will address this gap, by exploring the performance of Dutch cycling policies in 22 medium-sized cities since 2000. First, the existing ideas regarding the effectiveness of cycling policy are reviewed. These insights structure the exploration of data from Statistics Netherlands and the Dutch Cyclists' Union, complemented with a survey of local policy-makers by means of an explorative data-mining methodology called rough set analysis. Our findings support the following hypotheses regarding the performance of cycling policy in Dutch cities: first of all, the way cycling policy is implemented seems important: setting measurable and verifiable goals, following through with most of the proposed policy interventions, allowing for experimental measures to be explored and showing strong leadership. Second, providing adequate cycling infrastructure and decreasing the attractiveness of car use (e.g. by increasing parking tariffs and increasing the area of paid on-street car parking) seem to be key drivers. Finally, we found that external circumstances, such as demographic trends, seem to influence cycling policy outcomes. Future research is needed to test these hypotheses.

Differential scanning calorimetry analysis of an enhanced LiNi 0.8Co 0.2O 2 cathode with single wall carbon nanotube conductive additives

The replacement of traditional conductive carbon additives with single wall carbon nanotubes (SWCNTs) in lithium metal oxide cathode composites has been shown to enhance thermal stability as well as power capability and electrode energy density. The dispersion of 1 wt% high purity laser-produced SWCNTs in a LiNi 0.8Co 0.2O 2 electrode created an improved percolation network over an equivalent composite electrode using 4 wt% Super C65 carbon black; evidenced by additive connectivity in SEM images and an order of magnitude increase in electrode electrical conductivity. The cathode with 1 wt% SWCNT additives showed comparable active material capacity (185–188 mAh g −1), at a low rate, and Coulombic efficiency to the cathode composite with 4 wt% Super C65. At increased cycling rates, the cathode with SWCNT additives had higher capacity retention with more than three times the capacity at 10 C (16.4 mA cm −2). The thermal stability of the electrodes was evaluated by differential scanning calorimetry after charging to 4.3 V and float charging for 12 h. A 40% reduction of the cathode exothermic energy released was measured when using 1 wt% SWCNTs as the additive. Thus, the results demonstrate that replacing traditional conductive carbon additives with a lower weight loading of SWCNTs is a simple way to improve the thermal transport, safety, power, and energy characteristics of cathode composites for lithium ion batteries.

Treatment of Rapid-Cycling Bipolar Disorder: Are Antidepressants Mood Destabilizers?

Treatment of Rapid-Cycling Bipolar Disorder: Are Antidepressants Mood Destabilizers?