Towards a seascape typology. I. Zipf versus Pareto laws

Two data analysis methods, referred to as the Zipf and Pareto methods, initially introduced in economics and linguistics two centuries ago and subsequently used in a wide range of fields (word frequency in languages and literature, human demographics, finance, city formation, genomics and physics), are described and proposed here as a potential tool to classify space–time patterns in marine ecology. The aim of this paper is, first, to present the theoretical bases of Zipf and Pareto laws, and to demonstrate that they are strictly equivalent. In that way, we provide a one-to-one correspondence between their characteristic exponents and argue that the choice of technique is a matter of convenience. Second, we argue that the appeal of this technique is that it is assumption-free for the distribution of the data and regularity of sampling interval, as well as being extremely easy to implement. Finally, in order to allow marine ecologists to identify and classify any structure in their data sets, we provide a step by step overview of the characteristic shapes expected for Zipf's law for the cases of randomness, power law behavior, power law behavior contaminated by internal and external noise, and competing power laws illustrated on the basis of typical ecological situations such as mixing processes involving non-interacting and interacting species, phytoplankton growth processes and differential grazing by zooplankton.     

Transport ferroviaire régional en Allemagne. L’exemple de la région de Leipzig

The German regional rail passenger transport (SPNV) is, eighteen years after the railway reform of 1993, a dynamic one. Over the last fifteen years, passengers have increased by +43% and trains.km by +28%. There are more than 30 railway operators. Tenders drive this dynamism and newcomer’s market share is approaching 25% in 2011 (in train.km). The Leipzig region, which has seen the birth of long-distance rail transport with the great line Leipzig-Dresden inspired by F. List (1834), participate in this revival: since 2010, two operators, DB Regio and Veolia, share regional rail services. What early lessons can be drawn for the reform of the French TER?     

Phytoplankton patch patterns: Seascape anatomy in a turbulent ocean

Marine phytoplankton experience competition, predation, infection and aggregation occurring across distances of micrometres to centimetres. However, the consequences of these interactions influence global processes, such as climate and fisheries productivity. There is a long-standing default assumption that these global processes cannot be traced to plankton distributions and interactions below a few metres because of the homogenising effect of turbulence [Hutchinson, G.E., 1961. The paradox of the plankton. Am. Nat. 95, 137–146.; Siegel, D.A., 1998. Resource competition in a discrete environment: Why are plankton distributions paradoxical? Limnol. Oceanogr. 43, 1133–1146.]. We show that, in active turbulence, phytoplankton patches, on the order of 10 cm, have repeatable asymmetry and regular spacing over distances of centimetres to tens of metres. The regularity and hierarchical nature of the patches in mixed ocean water means that phytoplankton are distributed in a dynamic, but definite seascape topography, where groups of patches coalesce between intermittent turbulent eddies. These patches may link large scale processes and microscale interactions, acting as fundamental components of marine ecosystems that influence grazing efficiency, taxonomic diversity, and the initiation of aggregation and subsequent carbon flux.     

How to turn an innovative concept into a success? An application to seaport-related innovation

The main objective of this paper is ‘to assess the conditions, including policy support, under which innovative concepts have a high chance of getting adopted and being successful’. The work will start from the state-of-the-art with the following goals targeted. Firstly, to identify the paths that new innovative concepts usually follow, what key determinants are, which actors are involved, and what policy has been doing and can do. As part of this, a typology of variables is established, which will be the basis for the identification of successful adoption paths. Illustrations are provided of the performance of different innovative concepts in the seaport sector. A further goal is to propose policy recommendations, identify best practices, barriers to implementation and transferability of innovative concepts and processes. Finally, the research establishes developments needed in assessment methods and a methodological framework if innovative concepts are introduced.     

Employment suburbanisation, reverse commuting and travel behaviour by residents of the central city in the Paris metropolitan area

This paper analyses the relationship between employment suburbanisation in the Paris metropolitan area, the growth of reverse commuting and changes in the weekday travel behaviour of working residents of the central city over a 20-year period. The results show that the number of reverse commuters has significantly increased because the municipality of Paris has lost many jobs but few working residents whilst employment has developed in the suburbs. Reverse commuters are mainly and increasingly high-income professionals whose workplace is located close to the central city in employment sub-centres that are well served by public transport. Consequently reverse commuters have lower than average car use although differences exist and are related to their professional status. The policy implications of these findings are discussed in the conclusion.     

Symbolic dynamics and entropies of copepod behaviour under non-turbulent and turbulent conditions

We consider here behavioural activity of copepods as a succession of symbols associated with swimming states: slow swimming, fast swimming, break and grooming. We characterise these symbolic sequences using tools from symbolic dynamics: probability density function of the residence times in each state; transition probability at each time step; Shannon entropy and dynamic entropy. This approach is applied to the swimming behaviour of Centropages hamatus which we have analyzed as an example of application, in order to stress the differences associated with turbulent and non-turbulent conditions. We characterise in this theoretical framework the behavioural changes exhibited by the copepod under turbulent conditions.     

Distributional impacts of road pricing: The truth behind the myth

This paper shows that road pricing can be regressive, progressive or neutral, and refutes the generalised idea that road pricing is always regressive. The potential distributional impacts of a road pricing scheme are assessed in three English towns. It is found that impacts are town specific and depend on where people live, where people work and what mode of transport they use to go to work. Initial impacts may be progressive even before any compensation scheme for losers is taken into account. When the situation before the scheme is implemented is such that majority of drivers entering the area where the scheme would operate come from households with incomes above the average, it can be expected that, once the scheme is implemented, these drivers coming from rich households will continue to cross the cordon and will be prepared to pay the charge. In such a case the overall effect will be that on average, rich people will pay the toll and poor people will not.     

The new governance structure of French seaports: an initial post-evaluation

France undertook a large port reform in 2008, which came into force in 2010–2011. It mostly applies a landlord port model to major French seaports, with the prediction that doing so will restore competiveness. This article presents the 2008 port reform, discusses why it was needed, notably with regard to the underperformance of container traffic, and details how new governing bodies are sharing their responsibilities amongst themselves. To this end, a textual analysis of the agenda items for the governing bodies created since 2011 of the largest French seaport, Port of Marseille, provides a means to compare the items discussed by the former management bodies. This analysis identifies a trend, in which the supervisory board focuses on global issues, the advisory board addresses local issues, and the board of directors considers internal issues. Even if ongoing, this transition creates favorable conditions to work more efficiently and may represent a step toward the better performance of French seaports.