When supply travels far beyond demand: Causes of oversupply in Spain’s transport infrastructure

Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy.

When supply travels far beyond demand: Causes of oversupply in Spain’s transport infrastructure

Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy.

When supply travels far beyond demand: Institutional and regulatory causes of oversupply in Spain’s transport infrastructure

Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy. Based on our analysis, we also discuss policy remedies and suggest reforms in different regulatory areas, which could help improve the performance of Spain’s infrastructure policy.

DLL4 promotes continuous adult intestinal lacteal regeneration and dietary fat transport.

The small intestine is a dynamic and complex organ that is characterized by constant epithelium turnover and crosstalk among various cell types and the microbiota. Lymphatic capillaries of the small intestine, called lacteals, play key roles in dietary fat absorption and the gut immune response; however, little is known about the molecular regulation of lacteal function. Here, we performed a high-resolution analysis of the small intestinal stroma and determined that lacteals reside in a permanent regenerative, proliferative state that is distinct from embryonic lymphangiogenesis or quiescent lymphatic vessels observed in other tissues. We further demonstrated that this continuous regeneration process is mediated by Notch signaling and that the expression of the Notch ligand delta-like 4 (DLL4) in lacteals requires activation of VEGFR3 and VEGFR2. Moreover, genetic inactivation of Dll4 in lymphatic endothelial cells led to lacteal regression and impaired dietary fat uptake. We propose that such a slow lymphatic regeneration mode is necessary to match a unique need of intestinal lymphatic vessels for both continuous maintenance, due to the constant exposure to dietary fat and mechanical strain, and efficient uptake of fat and immune cells. Our work reveals how lymphatic vessel responses are shaped by tissue specialization and uncover a role for continuous DLL4 signaling in the function of adult lymphatic vasculature.

Persistent random walk model for transport trough thin slabs

We present a model for transport in multiply scattering media based on a three-dimensional generalization of the persistent random walk. The model assumes that photons move along directions that are parallel to the axes. Although this hypothesis is not realistic, it allows us to solve exactly the problem of multiple scattering propagation in a thin slab. Among other quantities, the transmission probability and the mean transmission time can be calculated exactly. Besides being completely solvable, the model could be used as a benchmark for approximation schemes to multiple light scattering.

Urban transport governance reform in Barcelona

The unusual mixed public-private structure of the urban bus market in the metropolitan area of Barcelona provides an interesting context in which to analyze the management challenges and opportunities of the partial privatization of public services. Initiatives used by the public regulator to promote competition for contracts, such as short term concessions to private contractors and the removal of entry barriers, have considerable potential for improving efficiency and quality. The growth in the share of routes managed by private firms in recent years shows that privatization is a credible threat that may well stimulate improved performance among public managers. The type of reform implemented in Barcelona is of interest to all metropolitan areas large enough to operate under constant returns to scale regimes, and suitable for potential concessions of routes in segregated areas inside the metropolitan area, so as not to miss out on the benefits of economies of density.

Uncertainty associated with Monte Carlo radiation transport in radionuclide metrology

In radionuclide metrology, Monte Carlo (MC) simulation is widely used to compute parameters associated with primary measurements or calibration factors. Although MC methods are used to estimate uncertainties, the uncertainty associated with radiation transport in MC calculations is usually difficult to estimate. Counting statistics is the most obvious component of MC uncertainty and has to be checked carefully, particularly when variance reduction is used. However, in most cases fluctuations associated with counting statistics can be reduced using sufficient computing power. Cross-section data have intrinsic uncertainties that induce correlations when apparently independent codes are compared. Their effect on the uncertainty of the estimated parameter is difficult to determine and varies widely from case to case. Finally, the most significant uncertainty component for radionuclide applications is usually that associated with the detector geometry. Recent 2D and 3D x-ray imaging tools may be utilized, but comparison with experimental data as well as adjustments of parameters are usually inevitable.

The role of the renal mineralocorticoid versus the glucocorticoid receptor in renal sodium and potassium transport

Dans le néphron distal sensible à l'aldostérone, le récepteur aux minéralocorticoïdes (RM) et le récepteur aux glucocorticoids (RG) sont exprimés et peuvent être liés et activés par l'aldostérone et le Cortisol, respectivement. La réabsorption rénale de sodium est principalement contrôlée par le RM. Cependant, des modèles expérimentaux in vitro et in vivo suggèrent que le RG pourrait également jouer un rôle dans le transport rénal du sodium. Afin d'étudier l'implication du RG et/ou du RM exprimés dans les cellules épithéliales adultes dans le transport rénal du sodium, nous avons généré deux modèles de souris, dans lesquelles l'expression du RG (Nr3c1Pax8/LC1) ou du RM (Nr3c2Pax8/LC1) peut être abolie de manière inductible et cela spécifiquement dans les tubules rénaux. Les souris déficientes pour le gène du RM survivent mais développent un phénotype sévère de PHA-1, caractérisé par un retard de croissance, une augmentation des niveaux urinaires de Na+, une diminution de la concentration du Na+ dans le plasma, une hyperkaliémie et une augmentation des niveaux d'aldostérone plasmatique. Ce phénotype empire et devient létal lorsque les souris sont nourries avec une diète déficiente en sodium. Les niveaux d'expression en protéine de NCC, de la forme phosphorylée de NCC et de aENaC sont diminués, alors que l'expression en ARN messager et en protéine du RG est augmentée. Une diète riche en Na+ et pauvre en K+ ne corrige pas la concentration élevée d'aldostérone dans le plasma pour la ramener à des niveaux conformes, mais est suffisante pour corriger la perte de poids et les niveaux anormaux des électrolytes dans le plasma et l'urine. -- In the aldosterone-sensitive distal nephron, both the mineralocorticoid (MR) and the glucocorticoid (GR) receptor are expressed. They can be bound and activated by aldosterone and Cortisol, respectively. Renal Na+ reabsorption is mainly controlled by MR. However, in vitro and in vivo experimental models suggest that GR may play a role in renal Na+ transport. Therefore, to investigate the implication of MR and/or GR in adult epithelial cells in renal sodium transport, we generated inducible renal tubule- specific MR (Nr3c2Pax8/LC1) and GR (Nr3c1Pax8/LC1) knockout mice. MR-deficient mice survived but developed a severe PHA-1 phenotype with failure to thrive, higher urinary Na+, decreased plasma Na+ levels, hyperkalemia and higher levels of plasma aldosterone. This phenotype further worsened and became lethal under a sodium-deficient diet. NCC protein expression and its phosphorylated form, as well as aENaC protein level were downregulated, whereas the mRNA and protein expression of GR was increased. A diet rich in Na+and low in K+ did not normalize plasma aldosterone to control levels, but was sufficient to restore body weight, plasma and urinary electrolytes. Upon switch to a Na+-deficient diet, GR-mutant mice exhibited transient increased urinary Na+ and decreased K+ levels, with transitory higher plasma K+ concentration preceded by a significant increase in plasma aldosterone levels within the 12 hours following diet switch. We found no difference in urinary aldosterone levels, plasma Na+ concentration and plasma corticosterone levels. Moreover, NHE3, NKCC2, NCC

Tackling Societal Challenges Related to Ageing and Transport Transition: An Introduction to Philosophical Principles of Causation Adapted to the Biopsychosocial Model

In geriatrics, driving cessation is addressed within the biopsychosocial model. This has broadened the scope of practitioners, not only in terms of assessing fitness to drive, but also by helping to maintain social engagements and provide support for transport transition. Causes can be addressed at different levels by adapting medication, improving physical health, modifying behaviour, adapting lifestyle, or bringing changes to the environment. This transdisciplinary approach requires an understanding of how different disciplines are linked to each other. This article reviews the philosophical principles of causality between fields and provides a framework for understanding causality within the biopsychosocial model. Understanding interlevel constraints should help practitioners overcome their differences, and favor transversal approaches to driving cessation.

Influence of transport and time on blood variables commonly measured for the athlete biological passport.

Some recent studies have characterized the stability of blood variables commonly measured for the Athlete Biological Passport. The aim of this study was to characterize the impact of different shipments conditions and the quality of the results returned by the haematological analyzer. Twenty-two healthy male subjects provided five EDTA tubes each. Four shipment conditions (24, 36, 48, 72 h) under refrigerated conditions were tested and compared to a set of samples left in the laboratory also under refrigerated conditions (group control). All measurements were conducted using two Sysmex XT-2000i analyzers. Haemoglobin concentration, reticulocytes percentage, and OFF-score numerical data were the same for samples analyzed just after collection and after a shipment under refrigerated conditions up to 72 h. Detailed information reported especially by the differential (DIFF) channel scatterplot of the Sysmex XT-2000i indicated that there were signs of blood deterioration, but were not of relevance for the variables used in the Athlete Biological Passport. As long as the cold chain is guaranteed, the time delay between the collection and the analyses of blood variables can be extended. Copyright© 2015 John Wiley & Sons, Ltd.

The role of surface vertical mixing in phytoplankton distribution in a stratified reservoir

We investigated convection caused by surface cooling and mixing attributable to wind shear stress and their roles as agents for the transport of phytoplankton cells in the water column by carrying out two daily surveys during the stratified period of the Sau reservoir. Green algae, diatoms, and cryptophyceae were the dominant phytoplankton communities during the surveys carried out in the middle (July) and end (September) of the stratified period. We show that a system with a linear stratification and that is subject to weak surface forcing, with weak winds , < 4 m S (-1) and low energy dissipation rate values of the order of 1028 m2 s23 or lower, enables the formation of thin phytoplankton layers. These layers quickly disappear when water parcels mix because there is a medium external forcing (convection) induced by the night surface cooling, which is characterized by energy dissipation rates on the order of , 5x10(-8)m2s(-3). During both surveys the wind generated internal waves during the entire diurnal cycle. During the day, and because of the weak winds, phytoplankton layers rise in the water column up to a depth determined by both solar heating and internal waves. In contrast, during the night phytoplankton mixes down to a depth determined by both convection and internal waves. These internal waves, together with the wind-driven current generated at the surface, seem to be the agents responsible for the horizontal transport of phytoplankton across the reservoir.

Analyse de réseau piéton et gestion scolaire: sinuosité, centricité et transport optimal régularisé

Que ce soit d'un point de vue, urbanistique, social, ou encore de la gouvernance, l'évolution des villes est un défi majeur de nos sociétés contemporaines. En offrant la possibilité d'analyser des configurations spatiales et sociales existantes ou en tentant de simuler celles à venir, les systèmes d'information géographique sont devenus incontournables dans la gestion et dans la planification urbaine. En cinq ans la population de la ville de Lausanne est passée de 134'700 à 140'570 habitants, alors que les effectifs de l'école publique ont crû de 12'200 à 13'500 élèves. Cet accroissement démographique associé à un vaste processus d'harmonisation de la scolarité obligatoire en Suisse ont amené le Service des écoles à mettre en place et à développer en collaboration avec l'université de Lausanne des solutions SIG à même de répondre à différentes problématiques spatiales. Établies en 1989, les limites des établissements scolaires (bassins de recrutement) ont dû être redéfinies afin de les réadapter aux réalités d'un paysage urbain et politique en pleine mutation. Dans un contexte de mobilité et de durabilité, un système d'attribution de subventions pour les transports publics basé sur la distance domicile-école et sur l'âge des écoliers, a été conçu. La réalisation de ces projets a nécessité la construction de bases de données géographiques ainsi que l'élaboration de nouvelles méthodes d'analyses exposées dans ce travail. Cette thèse s'est ainsi faite selon une dialectique permanente entre recherches théoriques et nécessités pratiques. La première partie de ce travail porte sur l'analyse du réseau piéton de la ville. La morphologie du réseau est investiguée au travers d'approches multi-échelles du concept de centralité. La première conception, nommée sinuo-centralité ("straightness centrality"), stipule qu'être central c'est être relié aux autres en ligne droite. La deuxième, sans doute plus intuitive, est intitulée centricité ("closeness centrality") et exprime le fait qu'être central c'est être proche des autres (fig. 1, II). Les méthodes développées ont pour but d'évaluer la connectivité et la marchabilité du réseau, tout en suggérant de possibles améliorations (création de raccourcis piétons). Le troisième et dernier volet théorique expose et développe un algorithme de transport optimal régularisé. En minimisant la distance domicile-école et en respectant la taille des écoles, l'algorithme permet de réaliser des scénarios d'enclassement. L'implémentation des multiplicateurs de Lagrange offre une visualisation du "coût spatial" des infrastructures scolaires et des lieux de résidence des écoliers. La deuxième partie de cette thèse retrace les aspects principaux de trois projets réalisés dans le cadre de la gestion scolaire. À savoir : la conception d'un système d'attribution de subventions pour les transports publics, la redéfinition de la carte scolaire, ou encore la simulation des flux d'élèves se rendant à l'école à pied. *** May it be from an urbanistic, a social or from a governance point of view, the evolution of cities is a major challenge in our contemporary societies. By giving the opportunity to analyse spatial and social configurations or attempting to simulate future ones, geographic information systems cannot be overlooked in urban planning and management. In five years, the population of the city of Lausanne has grown from 134'700 to 140'570 inhabitants while the numbers in public schools have increased from 12'200 to 13'500 students. Associated to a considerable harmonisation process of compulsory schooling in Switzerland, this demographic rise has driven schooling services, in collaboration with the University of Lausanne, to set up and develop GIS capable of tackling various spatial issues. Established in 1989, the school districts had to be altered so that they might fit the reality of a continuously changing urban and political landscape. In a context of mobility and durability, an attribution system for public transport subventions based on the distance between residence and school and on the age of the students was designed. The implementation of these projects required the built of geographical databases as well as the elaboration of new analysis methods exposed in this thesis. The first part of this work focuses on the analysis of the city's pedestrian network. Its morphology is investigated through multi-scale approaches of the concept of centrality. The first conception, named the straightness centrality, stipulates that being central is being connected to the others in a straight line. The second, undoubtedly more intuitive, is called closeness centrality and expresses the fact that being central is being close to the others. The goal of the methods developed is to evaluate the connectivity and walkability of the network along with suggesting possible improvements (creation of pedestrian shortcuts).The third and final theoretical section exposes and develops an algorithm of regularised optimal transport. By minimising home to school distances and by respecting school capacity, the algorithm enables the production of student allocation scheme. The implementation of the Lagrange multipliers offers a visualisation of the spatial cost associated to the schooling infrastructures and to the student home locations. The second part of this thesis recounts the principal aspects of three projects fulfilled in the context of school management. It focuses namely on the built of an attribution system for public transport subventions, a school redistricting process and on simulating student pedestrian flows.

Factors explaining urban transport systems in large European cities: A cross-sectional approach

The paper analyses the link between human capital and regional economic growth in the European Union. Using different indicat The importance of effective and efficient mobility in large cities is becoming essential for planners and citizens due to its impact in terms of social, economic and geographic development. The aim of this research is to determine factors explaining urban transport systems by estimating aggregate supply and demand equations for 45 large European cities. Supply and Demand equations are separately and jointly determined using OLS and SUR estimation models. On one hand, our findings suggest the importance of economic variables on the supply of public transport. On the other, we highlight the role of those factors influencing the generalized cost of transport as main drivers of demand for public transit. Additionally, regional variables are introduced to capture institutional heterogeneity in this service, and we find that regional patterns are powerful explanatory determinants of urban transportation systems in Europe.

Social Preferences and Transport Policy: The case of US speed limits

This article, in reviewing the longrunning US debate on speed limits, illustrates how a different valuation of the trade-off between private mobility needs and safety concerns can shape transport policies. It is argued that the regulatory decentralization debate, together with the speed limit in force in each state, obey the social preferences and valuation given to this tradeoff. Such a view is consistent with evidence that higher speed limits are to be found in states with greater private mobility needs, even though their fatality rates might be among the highest in the country. By contrast, lower speed limits and supporters of a low national speed limit are to be found in states that show a greater concern for safety outcomes and which are less dependent on private mobility. By reviewing these events and examining the role played by the main actors and analyzing their motivations, the article identifies important lessons for similar future discussions on transport policy.

Proposta per a la mobilitat en transport públic : MoveOnApp

This paper wants to show a solution for mobility in public transport. Nowadays, the high number of mobile devices with wireless geolocation and Internet data connection has become commonly used tools, as well as partial solutions to facilitate public transport focused on one means of transport (Bus, Underground ...). We collect information from public transport (means of transport, routes, schedules, fare information ...) and adapt it to different users (residents, visitors, public service staff ...). MoveOnApp is the solution adapting its user interface: finding nearby stops, planning a route, knowing schedules or real time service (connecting to the available services), or showing the route of the line. The system could incorporate new cities and regions, or new means of transport with updating service; at first we offered information of public transport from Palma (Majorca Island, Spain): moveOn Palma.