Evaluating congestion policy instruments in Jakarta

Jakarta, the capital of Indonesia, is notorious for its traffic jams. Over time, government authorities have developed and implemented several policy instruments to reduce congestion. These range from toll roads to public transportation to Travel Demand Management (TDM) measures such as the “three in one” scheme and the “odd-even” scheme. Unfortunately, like in many other cities, these measures have been implemented without due consideration for the evaluation of their impact on traffic flow, impeding a judgement on their success. In this research we evaluate the current odd-even scheme in Jakarta based on available data. We discuss methods by which effects on congestion can be measured and develop an approach that can be used by the responsible authorities for future interventions. We use traffic flow data on two main corridors and a number of alternative routes. We formulate a number of hypotheses to test if changes in traffic flows have happened. Results indicate that, while minor changes have occurred, a systematic effect of and causal relation with the odd-even scheme on traffic flows could not be established. Based on literature, we review and evaluate methods by which impacts of other relevant TDM schemes have been determined, and discuss their application to the Jakarta situation. We conclude that systematic evaluation is required based on a consistent methodology, which allows controlling for non-traffic related parameters that are of influence. Looking ahead, we provide recommendations on how the policy of electronic road pricing, which is to be implemented in 2019, may be evaluated

Analyzing potential transport mode shifting behavior from car to Bus Rapid Transit (BRT) in Nairobi, Kenya

Nairobi (Kenya) is an African fast-growing city highly dependent on automobiles and informal public transport. To remedy the inefficiencies of the transport system in Nairobi, the government has currently ongoing plans which include the implementation of mass transit systems, such as Bus Rapid Transit (BRT), to improve public transport to potentially reduce the negative externalities caused by automobile dependency. This study seeks to understand, by means of a stated choice experiment, to what extent and under which conditions car commuters would be willing to use BRT. Responses were collected from 510 car commuters, on three different residential locations, 3, 6 and 10 km away from the central business district. Results of our binary logit model reveal that utility values attached to cost, travel time and comfort do vary spatially and for different income and age groups. Overall, our sample was positive towards shifting to a cost-time effective and comfortable BRT service. Comfort was the most valued aspect, followed by travel time and travel fare, indicating that respondents are willing to pay for a service that ultimately results in decreasing the time spent on commuting trips. This study also contributes to the limited literature on transport-related choice experiments in African contexts

Kinetic modelling of competition and depletion of shared miRNAs by competing endogenous RNAs

Non-conding RNAs play a key role in the post-transcriptional regulation of mRNA translation and turnover in eukaryotes. miRNAs, in particular, interact with their target RNAs through protein-mediated, sequence-specific binding, giving rise to extended and highly heterogeneous miRNA-RNA interaction networks. Within such networks, competition to bind miRNAs can generate an effective positive coupling between their targets. Competing endogenous RNAs (ceRNAs) can in turn regulate each other through miRNA-mediated crosstalk. Albeit potentially weak, ceRNA interactions can occur both dynamically, affecting e.g. the regulatory clock, and at stationarity, in which case ceRNA networks as a whole can be implicated in the composition of the cell's proteome. Many features of ceRNA interactions, including the conditions under which they become significant, can be unraveled by mathematical and in silico models. We review the understanding of the ceRNA effect obtained within such frameworks, focusing on the methods employed to quantify it, its role in the processing of gene expression noise, and how network topology can determine its reach.Comment: review article, 29 pages, 7 figure

Analysis of the impact of length of stay on the quality of service experience, satisfaction and loyalty

Although length of stay is a relevant variable in destination management, little research has been produced connecting it with tourists' post-consumption behaviour. This research compares the post-consumption behaviour of same-day visitors with overnight tourists in a sample of 398 domestic vacationers at two Mediterranean heritage-and-beach destinations. Although economic research on length of stay posits that there are destination benefits in longer stays, same-day visitors score higher in most of the post-consumption variables under study. Significant differences arise in hedonic aspects of the tourist experience and destination loyalty. Thus, we propose that length of stay can be used as a segmentation variable. Furthermore, destination management organisations need to consider length of stay when designing tourism policies. The tourist product and communication strategies might be adapted to different vacation durations

Friction forces position the neural anlage

During embryonic development, mechanical forces are essential for cellular rearrangements driving tissue morphogenesis. Here, we show that in the early zebrafish embryo, friction forces are generated at the interface between anterior axial mesoderm (prechordal plate, ppl) progenitors migrating towards the animal pole and neurectoderm progenitors moving in the opposite direction towards the vegetal pole of the embryo. These friction forces lead to global rearrangement of cells within the neurectoderm and determine the position of the neural anlage. Using a combination of experiments and simulations, we show that this process depends on hydrodynamic coupling between neurectoderm and ppl as a result of E-cadherin-mediated adhesion between those tissues. Our data thus establish the emergence of friction forces at the interface between moving tissues as a critical force-generating process shaping the embryo