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We investigate strong normalization, confluence, and behavioral equality in the realm of session-based concurrency. These interrelated issues underpin advanced correctness analysis in models of structured communications. The starting point for our study is an interpretation of linear logic propositions as session types for communicating processes, proposed in prior work. Strong normalization and confluence are established by developing a theory of logical relations. Defined upon a linear type structure, our logical relations remain remarkably similar to those for functional languages. We also introduce a natural notion of observational equivalence for session-typed processes. Strong normalization and confluence come in handy in the associated coinductive reasoning: as applications, we prove that all proof conversions induced by the logic interpretation actually express observational equivalences, and explain how type isomorphisms resulting from linear logic equivalences are realized by coercions between interface types of session-based concurrent systems. (C) 2014 Elsevier Inc. All rights reserved.

We analyze the impact of temporary foreign workers (TFWs) and permanent immigrants on interprovincial mobility in Canada. Particular attention is given to the Canadian program of TFWs that has intensified enormously over the last 30 years. Results of the empirical analysis are analyzed through the lens of a small theoretical model that incorporates a job-matching framework (Pissaridès, 1985, 2000) in a migration model à la Harris and Todaro (1970). We find that the inflow of TFWs into a given province tends to substantially decrease net interprovincial mobility. This is not the case, however, for the inflow of permanent immigrants selected through the Canadian point system. On average, each inflow of 100 TFWs is found to decrease net interprovincial migrants within the year by about 50, a number substantially higher than is present in existing literature. This number increases to 180 in the long run. The negative impact of TFWs is ascribed to the fact that TFWs are hired directly by employers, take vacant jobs, and display employment and participation rates of close to 100 per cent. Our paper suggests that, in general, the impact of immigration on labor market conditions depends critically on the way immigrants are selected.

In this paper we first study patterns of separation and divorce among natives and migrants of different origin in Belgium. Second we link the divorce to internal mobility and test whether previous documented residential mobility patterns of divorced also apply for migrant populations. This study is novel in at least three respects. First of all only few studies have addressed levels and characteristics of divorce among migrant groups compared to the majority group population. We even go beyond a simply dichotomy and address the diversity in divorce among different origin groups living in Belgium. Second, our analyses not only cover divorce among married couples but we will just as well address separation among unmarried cohabiting couples. Third, we test what mobility patterns are predominant after divorce/separation among migrants and the majority group. Our multivariate analyses include factors of importance at the individual, couple and neighbourhood level and cover both levels and direction of moves. The analyses are based on the 2001 Belgian census, linked with population register data for 2006. All individuals who were part of a couple in 2001 are studied and we assess the levels of breakup of married and unmarried unions four years and three months later (in 2006). The data have rich information on individual and couple characteristics that will be taken into account in the multivariate analyses. For migrant origin we distinguish between six different (regions of) origins including both European and non-European migrants. We analyse the level of mobility linked to the divorce and study the direction of the residential moves of the partners as well as its determinants in more detail.

Research on international migrants traditionally focused on their international moves only. In this study we expand on this work by looking at the internal mobility of international migrants living in Belgium. In our paper we will pay special attention to the case of Brussels, the main urban area in Belgium. This article studies the level of internal mobility of international migrants as compared to the majority group. We also test whether the same or different patterns of mobility are found among different origin groups in Belgium. Second, we study where international migrants move to by distinguishing between different areas and regions. Finally, we question how and to what extent neighborhood characteristics are important for internal mobility of international migrants. Our work is based on the 2001 census and the 2006 register data of Belgium including the total population. This allows for more detailed insight into mobility patterns, a breakdown of different origins as well as a study of background characteristics relevant for mobility. Our data are furthermore unique in the sense that we do have detailed information on the evaluated and objective neighborhood characteristics. This allows assessing to what extent these factors are relevant for mobility and whether they are of similar importance for all groups.

This thesis analyzes the evolution of European competence as regards legal migration and in particular it focuses on the role and consistency acquired by estimated mobility circuits in the normative archetype outlined by the supranational legislator. In an attempt to determine if, when and why European Union law acquired ‘differential’ features as regards handling of “others” and the role that the establishment of mobility pathways in favor of those who do not possess an European citizenship could have into the common space, this study has become an analysis of the appearance of a proper European competence in the field of migration. By retracing backwards the strategy used by the European Union in approaching the migratory phenomenon, it has been observed in the first chapter that this phenomenon has suffered the effects of competence partitioning between ‘centre’ and ‘suburbs’. In the beginning this partitioning excluded the possibility for European institutions to directly affect the conditions of citizens from non-EU countries who legally live in the European territory. Moreover, it has been noticed how the European competence in this field has fluctuated for a long time between the aforementioned State unwillingness to discuss the regulation of this phenomenon and the launch of forms of cooperation between governments, up till the amendments to the normative structure of Amsterdam, Nice and Lisbon Treaties. The second chapter is divided in three different subsections each aiming at researching on a different feature of the migratory phenomenon legislation. More specifically, the chapter analyses the consistency of the European acquis as regards legal migration, by acknowledging the fragmentation of this subject as well as the continuous difficulties experienced by the European Union in bringing together member States’ legislations, only partly temperate thanks to the scheduled derogatory clauses in the various normative acts analyzed. The close examination of the sections of the directives adopted on the subject of legal migration has been preceded by an extensive analysis on the abovementioned acts drawn up by the European legislator. This analysis also focused on the reconstruction of the statute of non-EU citizens who are entitled to advantaged mobility rights identified by the European legislator thanks to the family ties with a European citizen. Finally, the last chapter focuses on an emerging aspect of the European legislation as regards the migration subject, i.e. the discipline of mobility in the community territory for workers from other countries. Here we excluded the existence of any international mandatory norms that bind the Member States to grant the access of foreigners on their territory and equally took note of the substantial noninvolvement of non-EU citizens from European initiatives in the field of freedom of circulation. argue that the dilemmas that characterized the supranational intervention in this area are such in a way justifiable according to the tensions between the Member States attempting to keep intact their discretional power over the normative framing of the 'community of citizens’ and the principle of equality. The contradictions that characterized the normative archetype created from the supranational legislator are particularly evident as regards the assignment at the citizens’ categories as well as at foreign workers’ categories of upcoming mobility rights. The final result is a system of mobility rights that prevent the migrant from being integrated in the society and, as a consequence, in the European labour market. This reveals the profoundly compromising and influenced nature of the mobility rights iure proprio recognized to non-EU citizens, despite the fact that the freedom of circulation is the most visible of the fundamental rights of European citizens.

Italy is one of the oldest countries in the world: the percentage of population over 65 years of age (20.4%) is topped only by Germany (20.5%) and Japan (22.6%). Italy displays also remarkable regional differences in the ageing process: the percentage of population aged 65 and over varies between 26.7% (in one of the North-western regions, Liguria) and 16.2 (in Campania, one of the regions of southern Italy). The aim of our paper is to investigate the reasons for that variation. We use regional population register data from 1955 to 2008 to show that both national and international population movements affected regional ageing in different ways. Differently from other researches already done, we explicitly take into account not only the number of (Italian and international interregional) migrants, but also the effect of their fertility on the population structure. Empirically, we compare the observed population structure with those of populations projected according to different hypothesis about migrations. To illustrate the case, we use initially two regions: Liguria, the oldest region in Italy, and Campania, the youngest one. For both regions, it is evident that the ageing of the population is greatly influenced by the dynamics of Italians’ migration movements until 2005 - obviously in different directions - and less by foreigners’. From 2005 on in Liguria, differently than in Campania, foreigners’ migrations have started to influence population ageing.

Los cambios de residencia que se producen dentro de una misma ciudad suponen una parte muy importante de toda la movilidad residencial, ya que en los movimientos migratorios residenciales domina la proximidad. En este trabajo analizamos la movilidad residencial registrada en la ciudad de Barcelona a partir de los datos del Departament d’Estadística del Ayuntamiento de la ciudad, que nos permite identificar los cambios de vivienda en el padrón municipal con origen y destino en la propia ciudad. La intención es visibilizar unos flujos residenciales que, a pesar de su importancia, son bastante desconocidos, y con un impacto clave en la redistribución de la población en la ciudad. Los resultados nos indican un alto volumen de movimientos que significa alrededor de un 80% de toda la movilidad metropolitana con origen o destino en la propia ciudad. Cuando no se traspasa un límite municipal, tres factores parecen explicar el sentido de los flujos, la proximidad con el lugar de residencia anterior, el nivel de renta de los barrios (especialmente selectivo en los barrios de rentas altas), y, en último lugar, la presencia de extranjeros en los flujos. Changes of residence which occur within the administrative boundary of a city represent a very important part of the whole residential mobility generated by it. Nevertheless, they are quite unknown, even if they have a key impact on the redistribution of the population within the city. In this paper we analyze residential mobility within the city of Barcelona, using local register data, aiming to make these flows visible. Results show that intra-city movements represent around 80% of all metropolitan mobility with origin in or destination to the city itself. When a municipal boundary is not crossed over when changing residence, three factors seem to explain these flows: 1) vicinity to the former place of residence; 2) the neighbourhood income level (especially selective in high income ones); and 3) the presence of foreigners. Este artículo forma parte del proyecto «Estrategias residenciales y modelos urbanos en la RMB (CSO2010-22117-C02-02), financiado por el Plan Nacional de I+D del Ministerio de Ciencia e Innovación.

In Italia, tra il 1995 e il 2005, i trasferimenti di residenza tra comuni italiani sono aumentati di oltre il 19%. Parallelamente il contributo degli stranieri alle migrazioni interne è arrivato a costituire il 14%. Fattori strutturali e maggiore predisposizione alla mobilità possono spiegare in parte il contributo degli stranieri alla mobilità interna. L’obiettivo è quello di individuare le caratteristiche strutturali delle migrazioni interne degli stranieri e degli italiani. Accanto alle misure tradizionali, viene utilizzato un modello gravitazionale che quantifica gli effetti sulla mobilità interna della consistenza delle popolazioni di origine e di destinazione dei flussi e della distanza tra le aree territoriali. Il modello gravitazionale ha consentito di evidenziare come anche in questo le tre variabili macro rappresentino una importante componente: l’effetto delle due popolazioni sembra essere più importante per gli italiani piuttosto che per gli stranieri, mentre quello contenitivo della distanza sembra essere più rilevante per gli stranieri. La stima condotta per il 1995, 2000 e 2005, mette in luce chiaramente il diverso comportamento tra italiani e stranieri e un’evoluzione differente del fenomeno. In Italy, between 1995 and 2005, the changes of residence between Italian municipalities increased of nearly 19%. Simultaneously, the contribution of the foreign population to internal migrations reached the level of 14%. Structural factors and a greater propensity to mobility may partly explain the foreign population’s contribution to internal mobility. This work aims at assessing the structural characteristics of internal migrations of the foreign and the Italian population. Besides the classical measures, we adopt a gravitational model which allows to quantify the effects on internal mobility due to the dimension of the populations in the areas of origin and destination and the distance between macro-areas. The estimates obtained for the years 1995, 2000 and 2005, clearly highlights the different behaviours of Italians and foreigners and a different evolution of phenomenon.

Migration plays an important role in neo-liberal regional adjustment. This paper explores the role of economic shocks in stimulating internal migration within Australia. Drawing on the experiences of retrenched Ansett Airlines employees, it argues that economic crisis impels some households to relocate but traps others in places with restricted employment prospects. For some, the crisis of retrenchment triggers inter-state migration to take up new jobs. For others, it prompts relocation to less expensive housing, often in a geographically proximate location. These opposing responses, which are different outcomes of similar causal processes, exacerbate regional inequalities since they selectively encourage younger skilled workers to enter growing regions. The combination of high housing costs and insecure employment discourages speculative migration. The paper concludes with a brief discussion of the policy implications of these findings. Refereed/Peer-reviewed

We show that the prediction of N-15 relaxation rates in proteins can be extended to systems with anisotropic global, rotational diffusion by using a network of coupled rotators (NCR), starting from a three-dimensional structure. The relaxation rates predicted by this method are confronted in several examples with experiments performed by other groups. The NCR spectral density functions are compared with the results obtained from reduced spectral density mapping. The consequence of the timescales of internal motions on the predicted relaxation rates and the effects of the predicted local anisotropy-present only in the case of anisotropic overall tumbling-on dynamic parameters, are discussed.

International audience; Insularity, a paradoxical metaphor for a continental space, seems the most adequate concept to evoke a deep imbalance of French Guyana, whereas the centre-periphery interactions are found at each scale (international, national and regional). The demographic hyper-concentration and focussing of economic activities on three bulk-headed poles – Cayenne, Kourou, Saint-Laurent – is characteristic of a space in crisis. Migratory movements both reinforce and embrace the spatial disequilibria. Given their low drai- résinage capacity, these centralities do not have a very polarizing effect within departmental space. The concept of space crisis is read as much in the hyper-concentration of the settlement within the littoral space overdeveloped as in the weakness of the internal movements of population and the interpolarized exchanges. Analysis of internal mobility based on changes of residence and residence-work commuting, as well as on international migration, enables a better understanding of the dynamics of exchanges. Conversely, their gravitational capacities find an echo outside the departmental surface, on national and international scales. The different types of international migration (political, economic, of competences) reveal the extraversion and the dependency of this overseas French territory.; L’insularité, métaphore paradoxale pour un espace continental, semble la notion la plus adéquate pour évoquer un profond déséquilibre de l’espace guyanais, alors que les interactions centres-périphéries se déclinent à toutes les échelles (internationale, nationale et régionale). La sur-concentration démographique et la focalisation économique organisées autour de trois pôles majeurs – Cayenne, Kourou, Saint-Laurent – et leur cloisonnement sont les caractéristiques d’un espace en crise, dont les migrations épousent, en les renforçant, les déséquilibres. Au regard de leur faible capacité de drainage, ces centralités sont peu polarisantes au sein de l’espace départemental. La notion de crise spatiale se lit autant dans l’hyperconcentration du peuplement au sein de l’espace littoral survalorisé que dans la faiblesse des mouvements internes de population et des échanges inter-polaires. L’analyse des mobilités internes par les changements de résidence et les navettes domicile-travail, puis des migrations internationales permet d’approcher la dynamique des échanges. À l’inverse, leurs capacités attractives trouvent un écho à l’extérieur de l’aire départementale, aux échelles nationale et internationale. Les types de migrations internationales (politiques, économiques, de compétences) révèlent l’extraversion et la dépendance de cet espace ultramarin.

The $\pi$-calculus is a process algebra which originates from CCS and permits a natural modelling of mobility (i.e., dynamic reconfigurations of the process linkage) using communication of names. Previous research has shown that the $\pi$-calculus has much greater expressiveness than CCS, but also a much more complex mathematical theory. The primary goal of this work is to understand the reasons of this gap. Another goal is to compare the expressiveness of {\em \no} calculi, i.e., calculi like $\pi$-calculus where mobility is achieved via exchange of names, and that of {\em agent-passing calculi}, i.e., calculi where mobility is achieved via exchange of agents. We separate the mobility mechanisms of the \pic into two, respectively called {\em internal mobility} and {\em external mobility}. The study of the subcalculus which only uses internal mobility, called \pii, suggests that internal mobility is responsible for {much} of the expressiveness of the $\pi$-calculus, whereas external mobility is responsible for {much} of the semantic complications. A pleasant property of \pii is the full symmetry between input and output constructs. Internal mobility is strongly related to agent-passing mobility. By imposing bounds on the order of the types of \pii and of the Higher-Order $\pi$-calculus \cite{San923} we define a hierarchy of name-passing calculi based on internal mobility and one of agent-passing calculi. We show that there is an exact correspondence, in terms of expressiveness, between the two hierarchies.

I find that large firms have a higher rate of job turnover in which internal mobility of workers is involved. These firms are able to reduce turnover costs, by making use of their ability to attain a higher internal mobility rate.