95 research outputs found

    Developing a representative driving cycle for paratransit that reflects measured data transients: case study in Stellenbosch, South Africa

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    Paratransit plays a critical role in meeting transportation needs in many cities in sub-Saharan Africa (SSA). However, it faces deep issues related to pollution, congestion, and safety. Understanding the driving patterns of paratransit in SSA can provide valuable insights into the transportation needs in the region, which is particularly relevant nowadays given the increasing focus on sustainable transportation solutions in Africa. Representative driving cycles, which provide a realistic simulation of the driving conditions a vehicle is likely to encounter, are key to framing policies for effective transportation management, vehicle design, and urban and regional planning. However, cycle development has been limited in SSA due to a lack of data and standardized testing procedures. This study develops a representative driving cycle using GPS data gathered on paratransit vehicles traveling around Stellenbosch, South Africa, providing a benchmark for evaluation and a platform for further research and testing in SSA’s dominant transport industry. A novel time series shape-based clustering methodology is employed that combines dynamic time warping and mixed integer programming to cluster micro-trips of varying length based on their time series shapes. Representative micro-trips from each cluster are stitched together with a maximum likelihood approach to curate the final cycle. By including transients from the measured data in cycle development, this novel approach to cycle development is particularly suited for capturing the notoriously unconventional and aggressive driving style of paratransit. The constructed cycle and several international cycles are assessed against the measured database on the basis of eight characteristic kinematic parameters. The constructed cycle emerges as the most fitting choice to represent paratransit operating conditions, with an average deviance of 3.65% across the parameters, compared to deviations of 23%–34% for the international cycles

    Front gardens to car parks: changes in garden permeability and effects on flood regulation

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    This study addresses the consequences of widespread conversion of permeable front gardens to hard standing car parking surfaces, and the potential consequences in high risk urban flooding hotspots, in the city of Southampton. The last two decades has seen a trend for domestic front gardens in urban areas to be converted for parking, driven by the lack of space and increased car ownership. Despite media and political attention, the effects of this change are unknown, but increased and more intense rainfall, potentially linked to climate change, could generate negative consequences as runoff from impermeable surfaces increases. Information is limited on garden permeability change, despite the consequences for ecosystem services, especially flood regulation. We focused on eight flooding hotspots identified by the local council as part of a wider urban flooding policy response. Aerial photographs from 1991, 2004 and 2011 were used to estimate changes in surface cover and to analyse permeability change within a digital surfacemodel in a GIS environment. The 1, 30 and 100 year required attenuation storage volumes were estimated, which are the temporary storage required to reduce the peak flow rate given surface permeability.Within our study areas, impermeable cover in domestic front gardens increased by 22.47% over the 20-year study period (1991–2011) and required attenuation storage volumes increased by 26.23% on average. These increases suggest that a consequence of the conversion of gardens to parking areas will be a potential increase in flooding frequency and severity — a situation which is likely to occur in urban locations worldwide

    High fidelity estimates of paratransit energy consumption from per-second GPS tracking data

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    Paratransit, in particular the minibus taxi, is the mainstay of public transport in sub-Saharan Africa. These vehicles are often second-hand, ageing, fuel inefficient, and expensive to operate - issues that electrification can ameliorate. However, modeling and planning large-scale transitions to electric paratransit require reliable estimates of vehicle energy consumption. This paper provides such estimates by applying a vehicle kinetic model to per-second GPS data gathered on minibus taxis. Data include 62 trips across three routes with different driving conditions near Stellenbosch, South Africa. We find a range of energy consumption from 0.29 to 0.51 kWh/km (mean = 0.39 kWh/km). Past estimates in literature relied on per-minute GPS data, which we show leads to inaccurate energy consumption estimates. We recommend new kWh/km values for modeling vehicle operations and grid impact, and discuss how future work can utilize our analysis to advance the transition to electric paratransit sub-Saharan Africa

    Forecast of electric vehicle uptake across counties in England : Dataset from S-curve analysis

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    Regional data from the UK Government's Department for Transport has been analyzed to produce a forecasted dataset of the uptake of electric vehicles (EVs) within Counties of England to the first quarter of the year 2100 using an S-curve methodology. This data includes all vehicles, not just cars. The historic proportion of electric vehicles in the fleets of these regions is calculated using data from 2011 Q4 to 2021 Q1. This data is then analyzed using SCATE, the S-Curve Adoption Tool for EVs to forecast the future proportion of electric vehicles in these Counties. Two data tables are presented: the reformatted historic data and the data from the S-curve analysis. Data is also presented for the collective UK

    Geospatial analysis to identify promising car parks for installing electric vehicle charge points : an Oxford case study

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    Historically in the UK, uptake of electric vehicles (EVs) has been dominated by those with off-street parking. In fact, a recent report by Deloitte found that nearly 90% of EV drivers currently charge privately. However, if we wish to meet the UK Government's targets of net zero by 2050 and no further sales of fully internal combustion engine vehicles after 2030, EV charging will need to be made accessible to those without driveways. Local Authorities and the companies they work with have a significant role to play in infrastructure planning to get ahead of the curve of accelerating EV uptake. This Visualising Transport Geography article investigates whether it is possible to identify locations for public EV chargers which may be more valuable to residents

    Empirical Bayes accomodation of batch-effects in microarray data using identical replicate reference samples: application to RNA expression profiling of blood from Duchenne muscular dystrophy patients

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    <p>Abstract</p> <p>Background</p> <p>Non-biological experimental error routinely occurs in microarray data collected in different batches. It is often impossible to compare groups of samples from independent experiments because batch effects confound true gene expression differences. Existing methods can correct for batch effects only when samples from all biological groups are represented in every batch.</p> <p>Results</p> <p>In this report we describe a generalized empirical Bayes approach to correct for cross-experimental batch effects, allowing direct comparisons of gene expression between biological groups from independent experiments. The proposed experimental design uses identical reference samples in each batch in every experiment. These reference samples are from the same tissue as the experimental samples. This design with tissue matched reference samples allows a gene-by-gene correction to be performed using fewer arrays than currently available methods. We examine the effects of non-biological variation within a single experiment and between experiments.</p> <p>Conclusion</p> <p>Batch correction has a significant impact on which genes are identified as differentially regulated. Using this method, gene expression in the blood of patients with Duchenne Muscular Dystrophy is shown to differ for hundreds of genes when compared to controls. The numbers of specific genes differ depending upon whether between experiment and/or between batch corrections are performed.</p

    Acute Physiologic Effects of Performing Yoga In The Heat on Energy Expenditure, Range of Motion, and Inflammatory Biomarkers

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    International Journal of Exercise Science 13(3): 802-817, 2020. Performing yoga in a heated environment (HY) is a popular exercise mode purported to improve range of motion (ROM), body composition, and aerobic fitness. The purpose of this investigation was to compare a session of HY to room temperature yoga (RTY) with regards to ROM, oxygen consumption, caloric expenditure, and biomarkers of acute stress and inflammation. Sixteen experienced yoga practitioners (F14, M2; 40 ± 11yr; 22.6 ± 1.8 kg/m2) completed a 1-hour standardized Bikram sequence in HY (105⁰F, 40⁰C) and RTY (74⁰F, 23.3⁰C) conditions (order of conditions randomized, humidity standardized at 40%). Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. ROM measures were taken pre and post-exercise at the elbow, shoulder, hip, and knee. Cytokines interleukin 6,10 (IL-6, IL-10) and tumor-necrosis-factor alpha (TNF-α) were analyzed from blood samples collected pre- and 30-minutes post-exercise. Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. Both bouts elicited similar acute changes in ROM although HY elicited a greater increase in hip abduction (RTYΔ⁰ = 2.3 ± 1.3|HYΔ⁰ = 6.6 ± 1.5; p \u3c 0.05). Mean VO2, peak VO2, %VO2max, HR, and kcal expenditure did not differ between conditions. RER was lower during the HY (RTY = 0.95 ± 0.02| HY = 0.89 ± 0.02; p \u3c 0.05) with a concomitant elevation in fat oxidation (RTY = 0.05 ± 0.01|HY = 0.09 ± 0.01, g‧min-1; p \u3c 0.05) and decrease in carbohydrate oxidation (RTY = 0.51 ± 0.04|HY = 0.44 ± 0.03, g‧min-1; p \u3c 0.05). Serum IL-6 was increased (15.5 ± 8.0-fold) following HY only (p \u3c 0.05). HY does not significantly elevate aerobic energy cost compared to RTY but may acutely increase fat substrate utilization and hip ROM. Future studies remain needed to establish dose-response relationships for including HY or RTY into well-rounded fitness programs

    Survey of Telemedicine by Pediatric Nephrologists During the COVID-19 Pandemic

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    Introduction: The slow increase in use of telemedicine began to expand rapidly, along with reimbursement changes, during the coronavirus disease-2019 (COVID-19) pandemic. Standardized protocols for these services are lacking but are needed for effective and equitable health care. In this study, we queried pediatric nephrologists and their patients about their telemedicine experiences during the pandemic. Methods: Surveys that were in compliance with the Health Insurance Portability and Accountability Act were deployed online to patients and physicians. Results: We collected survey responses from 400 patients and 197 pediatric nephrologists. Patients reported positive experiences with telemedicine visits as it was logistically easier than in-person visits. Patients also felt that the quality of their visits were equivalent to what they would receive in person. Physicians used a wide variety of online systems to conduct synchronous telemedicine with Zoom (23%), EPIC (9%), Doxy.me (7%), services not specified (37%), or a mix of local or smaller services (24%). Most physicians\u27 concerns were related to technological issues and the ability to procure physical exams and/or laboratory results. Conclusions: There is a paucity of published trials on telemedicine services in pediatric nephrology. Virtual care was feasible and acceptable for patients, caregivers, and providers during the COVID-19 pandemic
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