Effects of the 80 km/h and variable speed limits on air pollution in the metropolitan area of Barcelona

In 2008 the regional government of Catalonia (Spain) reduced the maximum speed limit on several stretches of congested urban motorway in the Barcelona metropolitan area to 80 km/h, while in 2009 it introduced a variable speed system on other stretches of its metropolitan motorways. We use the differences-in-differences method, which enables a policy impact to be measured under specific conditions, to assess the impact of these policies on emissions of NOx and PM10. Empirical estimation indicate that reducing the speed limit to 80 km h-1 causes a 1.7 to 3.2% increase in NOx and 5.3 to 5.9% in PM10. By contrast, the variable speed policy reduced NOx and PM10 pollution by 7.7 to 17.1% and 14.5 to 17.3%. As such, a variable speed policy appears to be a more effective environmental policy than reducing the speed limit to a maximum of 80 km/h.

L'utilisation des anticoagulants oraux directs chez les patients âgés : les limites de la médecine fondée sur les preuves [The use of the new direct oral anticoagulants among older subjects: The limits of the evidence-based medicine?].

The growing use of direct oral anticoagulants, in particular among older subjects, raises questions about the limits of the evidence-based medicine. The phase III studies that have validated the efficacy and the safety profile of these molecules (dabigatran, rivaroxaban, apixaban, edoxaban) in their both indications, the venous thromboembolic disease and the non-valvular atrial fibrillation raise concerns in four major fields: the financial support of pharmaceutical companies, the links of interest for many authors with the industry, the study design (exclusively non-inferiority studies), and the poor representativeness of the older subjects included. All these points are discussed, using data of sub-groups studies, post-marketing studies and recent meta-analysis. The lack of data for the very old subjects, with frailty or comorbidities, remains the main concern from these phase III studies.

Indications et limites de la thoracoscopie en 1994. [Indications and limits of thracoscopy in 1994.]

Reléguée au rang de moyen diagnostique occasionnel avec l'avènement de la streptomycine dès 1945, la thoracoscopie a repris depuis trois à cinq ans un rôle prépondérant dans l'armement du chirurgien thoracique, comme moyen diagnostique et surtout comme outil thérapeutique. Dans cet article, nous faisons le point quant à la place actuelle de la thoracoscopie face aux différentes pathologies thoraciques, pulmonaires, médiastinales et oesophagiennes. Dans certaines indications (pneumothorax, infiltrats pulmonaires diffus, nodule pulmonaire isolé), cette technique en pleine expansion a déjà clairement démontré sa supériorité. Dans d'autres cas, en particulier dans les affections néoplasiques, son application est encore le sujet de controverses.

The environmental effects of changing speed limits: a quantile regression approach

Two speed management policies were implemented in the metropolitan area of Barcelona aimed at reducing air pollution concentration levels. In 2008, the maximum speed limit was reduced to 80 km/h and, in 2009, a variable speed system was introduced on some metropolitan motorways. This paper evaluates whether such policies have been successful in promoting cleaner air, not only in terms of mean pollutant levels but also during high and low pollution episodes. We use a quantile regression approach for fixed effect panel data. We find that the variable speed system improves air quality with regard to the two pollutants considered here, being most effective when nitrogen oxide levels are not too low and when particulate matter concentrations are below extremely high levels. However, reducing the maximum speed limit from 120/100 km/h to 80 km/h has no effect – or even a slightly increasing effect –on the two pollutants, depending on the pollution scenario. Length: 32 pages

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.

Analytical investigation of the atmospheric radiation limits in semigray atmospheres in radiative equilibrium

We model the wavelength-dependent absorption of atmospheric gases by assuming constant mass absorption coefficients in finite-width spectral bands. Such a semigray atmosphere is analytically solved by a discrete ordinate method. The general solution is analyzed for a water vapor saturated atmosphere that also contains a carbon dioxide-like absorbing gas in the infrared. A multiple stable equilibrium with a relative upper limit in the outgoing long-wave radiation is found. Differing from previous radiative–convective models, we find that the amount of carbon dioxide strongly modifies the value of this relative upper limit. This result is also obtained in a gray (i.e., equal absorption of radiation at all infrared wavelengths) water vapor saturated atmosphere. The destabilizing effect of carbon dioxide implies that massive carbon dioxide atmospheres are more likely to reach a runaway greenhouse state than thin carbon dioxide ones

Limits of Meritocracy. How Fields of Study and Gender Segregation Affect Social Stratification in Finland

This dissertation critically reviews the idea of meritocracy from both a theoretical and an empirical perspective. Based on a discussion of classical texts of social philosophy and sociology, it is argued that meritocracy as a concept for social stratification is best compatible with the sociological tradition of status attainment research: both frame social inequality in primarily individualistic terms, centring on the role of ascribed (e.g., gender, social background) and achieved (e.g., educational qualifications) characteristics for determining individuals’ socioeconomic rewards. This theoretical argument introduces the research problem at the core of this dissertation: to what extent can the individualistic conception of social stratification be maintained empirically? Fields of study and their interaction with educational attainment levels play a prominent role in the analysis of this question. Drawing on sociological versions of segmented labour market theory, it is assumed that fields of study may channel individuals into heterogeneous political-economic contexts on the labour market, which potentially modify the socioeconomic benefit individuals derive from their qualification levels. The focus on fields of study may also highlight economic differentials between men and women that derive from the persisting segregation of men’s and women’s occupational and educational specializations rather than direct gender discrimination on the labour market. The quantitative analyses in this dissertation consist of three research articles, which are based primarily on Finnish data, but occasionally extend the view to other European countries. The data sources include register-based macro- and microdata as well as survey data. Article I examines the extent and the patterns of gender segregation within the Finnish educational system between 1981 and 2005. The results show that differences between men’s and women’s field specializations have for the most part remained stable during this period, with particularly high levels of gender segregation observed at lower educational levels. The focus in Article II rests on the effects of gender-segregated fields of study on higher education graduates’ occupational status. It is shown that fields of study matter for accessing professional jobs and avoiding low-skilled positions in Finland: at the early career stage, particularly polytechnic graduates from female-dominated fields are less likely to work in professional positions. Finnish university graduates from male-dominated fields were more likely than their peers with different specializations to work as professionals, yet they also faced a greater risk of being sorted into lowskilled jobs if they failed to make use of this advantage. Article III proceeded to analyse the joint impact of educational qualification levels and fields of study on young adults’ median earnings in Finland between 1985 and 2005. The results show that qualification levels do not confer a consistent benefit in the process of earnings stratification. Advanced qualifications raise median earnings most clearly among individuals specializing in the same field of study. When comparing individuals with different field specializations, on the other hand, higher-level qualifications do not necessarily lead to higher median earnings. Overall, the findings of this dissertation reveal a heterogeneous effect of education for achieving social positions, which challenges individual-centred, meritocratic accounts of social stratification and underlines the problematic lack of structural and institutional dimensions in the dominant account of social status attainment.

On Limits to the Use of Linear Markov Strategies in Common Property Natural Resource Games

We derive conditions that must be satisfied by the primitives of the problem in order for an equilibrium in linear Markov strategies to exist in some common property natural resource differential games. These conditions impose restrictions on the admissible form of the natural growth function, given a benefit function, or on the admissible form of the benefit function, given a natural growth function.

Certification of community-based forest enterprises (CFEs): limits of the Brazilian experiences

The Brazilian Amazon is one of the world’s largest tropical forests. It supplies more than 80 % of Brazil’s timber production and makes this nation the second largest producer of tropical wood. The forestry sector is of major importance in terms of economic production and employment creation. However, the Brazilian Amazon is also known for its high deforestation rate and for its rather unsustainably managed timber resources, a fact which puts in the balance the long-term future of the forestry sector in the region. Since the mid- 1990s, with strong support from World Wildlife Fund (WWF), the number of tropical forests certified by the Forest Stewardship Council (FSC) has significantly increased. This is especially true for projects sponsored by large scale companies. The number of community- based forest management projects has also increased. Certification of community-based forest enterprises (CFEs) was initially a goal for the sponsors and community members. Certification is viewed as a way to reach alternative timber markets. In Brazil, the state of Acre has the highest concentration of CFEs certified by FSC. Most of them have been implemented with the support of environmental NGOs and public funds. Environmental NGOs strongly defend the advantages of certification for communities; however, in reality, this option is not that advantageous. Despite all the efforts, the number of participants in each project remains low. Why is this occurring? In this paper, we analyze the underlying motives of a few individual’s participation in CFEs certification projects. We aim to present and discuss some factors that shape the success of CFEs and their later certification. The results are based on surveys conducted in two certified CFEs in the state of Acre.

Building Beyond Limits : Fantastic Collisions Between Bodies and Machines in French and English Fin-de-Siècle Literature

«Construire hors limite: collisions fantastiques entre corps et machines dans la littérature fin-de-siècle française et anglaise» explore un ensemble de textes qui ont surgi à la fin du dix-neuvième siècle en réponse et en réaction à la fulgurante évolution de l’environnement scientifique et technologique, et qui considèrent la relation entre l’homme et la machine en fantasmant sur la zone grise où ils s’intersectent. Les principaux textes étudiés comprennent L’Ève future de Villiers de l’Isle-Adam, Le Surmâle d’Alfred Jarry, Trilby de George Du Maurier, Le Château des Carpathes de Jules Verne, ainsi qu’une sélection de contes dont nous pouvons qualifier de «contes à appareils», notamment «La Machine à parler» de Marcel Schwob. Utilisant la théorie des systèmes comme base méthodologique, cette dissertation cherche à réinterpréter les textes de la fin du dix-neuvième siècle qui naviguent les limites de l’humain et du mécanique et les surfaces sensibles où ils se touchent et interagissent en les réinscrivant dans un projet plus vaste de construction d’identité qui défie le temps chronologique et les échelles mathématiques. Le lien entre la théorie des systèmes et l’architecture – comme méthode d’organisation d’espace blanc en espace habitable – est exploré dans le but de comprendre la manière dont nous façonnons et interprétons le néant à l’origine de l’identité individuelle, et par association collective, en pratiquant littéralement la schématisation et la construction du corps. Des auteurs tels Villiers et Jarry imaginent la construction du corps comme une entreprise scientifique nécessairement fondée et réalisée avec les matériaux et les technologies disponibles, pour ensuite démanteler cette proposition en condamnant le corps technologique à la destruction. La construction d’une identité amplifiée par la technologie prend donc des proportions prométhéennes perpétuellement redessinées dans des actes cycliques de rasage (destruction) et d’érection (édification), et reflétées dans l’écriture palimpsestique du texte. L’intégrité du corps organique étant mis en question, le noyau même de ce que signifie l’être (dans son sens de verbe infinitif) humain pourrait bien s’avérer, si l’on considère la correspondance entre perte de voix et état pathologique dans les textes de Du Maurier, Verne et Schwob, être une structure des plus précaires, distinctement hors sens (unsound).

Right to Food, Food Security and Food Aid Under International Law, or the Limits of a right-based approach

The right to food has become a pillar of international humanitarian and human rights law. The increasing number of food-related emergencies and the evolution of the international order brought the more precise notion of food security and made a potential right to receive food aid emerge. Despite this apparent centrality, recent statistics show that a life free from hunger is for many people all over the world still a utopian idea. The paper will explore nature and content of the right to food, food security and food aid under international law in order to understand the reasons behind the substantial failure of this right-centred approach, emphasising the lack of legal effects of many food-related provisions because of excessive moral connotations of the right to be free from hunger. Bearing in mind the three-dimensional nature of food security, the paper will also suggest that all attention has been focused on the availability of food, while real difficulties arise in terms of accessibility and adequacy. Emergency situations provide an excellent example of this unbalance, as the emerging right to receive food aid focus itself on the availability of food, without improving local production and adequacy. Looking at other evolving sectors of international law, such as the protection of the environment, and particularly the safeguard of biological diversity, alternative solutions will be envisaged in order to “feed” the right to food.

Interaction between Public Transportation and Urbanization in the Mexico City Metropolitan Area: an Expansive Model Reaching its Limits

In Metropolitan Area of Mexico City, most of urban displacements happen through semi formal public transportation: small and medium capacity vehicles operated by small private enterprises, through a concession scheme. This kind of public transportation has been playing a major role in the Mexican capital. On one hand, it has been one of the conditions for urbanization to be possible. On the other hand, despite its uncountable deficiencies, public transportation has allowed for a long time the whole population to be able to move within this huge metropolis. However, that important function with regards to integration has now reached its limits in the most recent suburbs of the city, where a new mode of urbanization is taking place, based on massive production of very big social housing gated settlements. Public transportation tends to constitute here a factor of exclusion and households meet with important difficulties for their daily mobility.