Dysregulation of principal cell miRNAs facilitates epigenetic regulation of AQP2 and results in nephrogenic diabetes insipidus

Background MicroRNAs (miRNAs), formed by cleavage of pre-microRNA by the endoribonuclease Dicer, are critical modulators of cell function by post-transcriptionally regulating gene expression. Methods Selective ablation of Dicer in AQP2-expressing cells (DicerAQP2Cre1 mice) was used to investigate the role of miRNAs in the kidney collecting duct of mice. Results The mice had severe polyuria and nephrogenic diabetes insipidus, potentially due to greatly reduced AQP2 and AQP4 levels. Although epithelial sodium channel levels were decreased in cortex and increased in inner medulla, amiloride-sensitive sodium reabsorption was equivalent in DicerAQP2Cre1 mice and controls. Small-RNA sequencing and proteomic analysis revealed 31 and 178 significantly regulated miRNAs and proteins, respectively. Integrated bioinformatic analysis of the miRNAome and proteome suggested alterations in the epigenetic machinery and various transcription factors regulating AQP2 expression in DicerAQP2Cre1 mice. The expression profile and function of three miRNAs (miR-7688-5p, miR-8114, and miR-409-3p) whose predicted targets were involved in epigenetic control (Phf2, Kdm5c, and Kdm4a) or transcriptional regulation (GATA3, GATA2, and ELF3) of AQP2 were validated. Luciferase assays could not demonstrate direct interaction of AQP2 or the three potential transcription factors with miR-7688-5p, miR-8114, and miR-409-3p. However, transfection of respective miRNA mimics reduced AQP2 expression. Chromatin immunoprecipitation assays demonstrated decreased Phf2 and significantly increased Kdm5c interactions at the Aqp2 gene promoter in DicerAQP2Cre1 mice, resulting in decreased RNA Pol II association. Conclusions Novel evidence indicates miRNA-mediated epigenetic regulation of AQP2 expression

The definition of bus fleet operational parameters: The dwell time estimation

Public transport may represent a useful tool to increase the sustainability of areas, especially in urban and suburban contexts. The attractiveness of a transport system, especially in the case of buses, is closely linked to its reliability which depends in turn on the adoption of adequate planning and design methodologies. Currently, although the dwell time (i.e. the time spent by a vehicle at a bus stop for boarding and alighting passengers) may represent a relevant rate of the total travel time, it generally is adopted as constant and prefixed. In this context, this paper aims to identify an analytical formulation to determine at each bus stop the corresponding dwell time to increase the reliability of the planned service. Numerical results have shown the correctness of the proposed approach

The use of Automatic Vehicle Location (AVL) data for improving public transport service regularity

Smart and sustainable mobility systems are crucial elements for tomorrow's cities, whose facilities will be increasingly connected automated and environmentally friendly. Therefore, many strategies based on alternatively-powered vehicles, shared transport modes and micro-mobility solutions are being developed. However, the promotion of traditional public transport solutions still remains a key factor. Therefore, increasing their attractiveness, thus positively influencing the modal split, turns out to be an important goal to be achieved. In this context, we proposed a methodology, based on the use of Automatic Vehicle Location (AVL) data, for improving transit service performance. Finally, in order to show the feasibility of the proposed approach, it has been applied to a real bus line operating in the south of Italy

Assumptions and simulation of passenger behaviour on rail platforms

Current techniques of Travel Demand Management (TDM) are based on the simulation of users’ reactions to implemented strategies. Indeed, the correct modelling of user behaviour may be considered important for managing public transport systems. Especially in high density contexts, performance of the mass-transit system may represent one of the main tools of decision-makers for affecting users’ choices. In this paper, we focus on the behaviour of users waiting on rail/metro platforms, analysing boarding priorities when a train arrives based on the traditional First In – First Out (FIFO) approach and comparing it with Random In – First Out (RIFO) behaviour. The approaches are then applied in the case of a real metro line operating under different congestion levels

A multimodal equilibrium model with crossed congestion for simulating the urban freight distribution

Urban road networks are shared at least by three different kinds of vehicles: personal cars, buses and freight vehicles. In a previous paper (D'Acierno et al., 2002), the authors proposed a multimodal assignment model that was able to jointly simulate transit and road network, including the mode choice model inside the assignment procedure.In this paper we propose to extend the previous model to the urban freight distribution simulation, considering the crossed congestion among all three transportation systems.In this case we have to consider two origin-destination matrices: one for passengers and the other one for freights; the passenger matrix is assigned to the multimodal network while the freight matrix is assigned to the road network. The proposed assignment model allow to simulate jointly mode and route choice for passenger and route choice for freight, considering the reciprocal influences on congestion.The proposed model can be useful for simulating the real effects of urban freight distribution on urban congestion and on passenger mode choices; moreover, it can be adopted for managing the urban freight distribution so to minimise the impact on traffic congestion.In the paper a general fixed-point model will be formalised, its theoretical properties will be studied, a multimodal multiuser assignment model will be proposed and it will be tested on a real network.Future research will be addressed to adopt the proposed model and algorithm inside urban freight distribution optimization problem in order to find the distribution pattern with minor impact on urban congestion and to propose models that include among available choices also the starting time for passenger and the delivery time for freight

Replanning public transport services in the case of budget reductions

The planning of an efficient and effective public transport system is a key element in managing modern mobility both in densely populated urban areas and in peripheral and/or rural areas where the population densities are considerably lower. Indeed, the presence of public transport designed to meet travel demand could allow a reduction in negative externalities produced by private cars without excessively penalising user travel times or accessibility to different zones. However, the recent financial crisis has forced many public administrations to reduce resources allocated to public services and replan related services in order to mitigate negative effects on users. In this context, we propose two methods for replanning public transport services in the case of budget reductions. The first approach, indicated as CLP (Change the Least Possible), can be adopted when the initial services are actually able to satisfy user needs and in some time slots are probably surplus to requirements. The second approach, CFR (Change the FRamework), instead, should be used when the initial services are already inadequate or barely sufficient to serve users in the study area. Indeed, in the latter case, it is very difficult to eliminate some runs without producing a significant reduction in levels of service. Finally, the proposed methodology has been applied by our research group when replanning bus services in the provinces of Naples and Avellino, in southern Italy, where we implemented respectively the CLP and CFR approaches by solving some problems related to interference with pre-existing planning tools