Postface

Depuis près de trente ans, quarante si l’on inclut la période des visionnaires californiens, plusieurs centaines d’auteurs ont circonscrit et modélisé des voies de transition écologique et sociale pour les villes occidentales, dans l’idée de rompre leur dépendance au sentier à l’égard des énergies fossiles, des métaux et terres rares, des échanges mondiaux pour leurs moindres besoins de subsistance, de métabolismes hors-sol et de processus de décision qui le sont tout autant, si peu ajustés ..

Réappropriation du sol et société civile dans deux villes russes

L’étude des mouvements écologistes dans deux villes russes, Tver et Nijni-Novgorod, invite à réfléchir sur les liens qui s’inventent entre l’action environnementale très locale et la constitution d’une société civile en Russie. Le retrait de l’État fédéral et le manque de politiques municipales en matière environnementale poussent les citadins préoccupés par l’état de l’environnement à toutes les échelles du territoire à se prendre en charge et ce, à des niveaux sans précédent. L’article s’attache à deux exemples de réappropriation des sols et de l’environnement immédiat, montrant les relations qui se dessinent entre préservation ou requalification de l’environnement et réclamation du droit de propriété, faisant de la réappropriation territoriale une figure complexe, à la croisée de besoins socio-écologiques et économiques.The study of ecological movements in two Russian cities (Tver and Nijni-Novgorod) incites reflection on the links being developed between local environmental action and the creation of civil society in Russia. The withdrawal of the federal State and the paucity of municipal environmental policy give rise to an unusual degree of involvement by those citizens who are concerned by the state of their local or extended environment. We address two examples of (re)appropriation of the land and of the local environment by inhabitants, describing the relationships taking shape between the preservation or the restoration of the environment and issues of land ownership. This reappropriation becomes a complex process, at the crossroads of socio-ecological and economic needs

Inégalités écologiques, inégalités sociales. Bibliographie indicative

Cette liste de références est basée essentiellement sur les documents cités, relatifs au thème des inégalités sociales face à l'environnement en général, augmentée de quelques titres. Il s'agit avant tout d'un instrument de travail pour des personnes intéressées par le thème

Unpacking the formation of favourable environments for urban experimentation: the case of the Bristol energy scene

Urban experimentation with sustainability has been gaining prominence in policy and academic discourses about urban transformations, spurring the creation of urban living laboratories and transition arenas. However, the academic literature has only begun examining why experimentation flourishes in particular cities, and why it conforms to place-specific styles. Meanwhile, the strategic niche management (SNM) tradition has extensively explored how protective spaces for experimentation emerge but has dealt only tangentially with why this happens in particular places. In this paper, we develop an approach for unpacking the formation of favourable environments for experimentation in specific places. We adopt an abductive research design to create a dialogue between distinct theoretical positions and one in-depth case study. Our case examines the formation of the Bristol energy scene, which hosts a variety of experimental initiatives concerning civic energy alternatives. Based on our findings, we refine the understanding of the processes shaping this experimental setting. There is value in characterising the ‘genealogy’ of experimental spaces and acknowledging their antecedents, path-dependencies and place-specificities. Efforts to foster urban transformation demand nuanced accounts of how places become experimental because they are not static backgrounds for experimentation

Virulence and Pathogen Multiplication: A Serial Passage Experiment in the Hypervirulent Bacterial Insect-Pathogen Xenorhabdus nematophila

The trade-off hypothesis proposes that the evolution of pathogens' virulence is shaped by a link between virulence and contagiousness. This link is often assumed to come from the fact that pathogens are contagious only if they can reach high parasitic load in the infected host. In this paper we present an experimental test of the hypothesis that selection on fast replication can affect virulence. In a serial passage experiment, we selected 80 lines of the bacterial insect-pathogen Xenorhabdus nematophila to multiply fast in an artificial culture medium. This selection resulted in shortened lag phase in our selected bacteria. We then injected these bacteria into insects and observed an increase in virulence. This could be taken as a sign that virulence in Xenorhabdus is linked to fast multiplication. But we found, among the selected lineages, either no link or a positive correlation between lag duration and virulence: the most virulent bacteria were the last to start multiplying. We then surveyed phenotypes that are under the control of the flhDC super regulon, which has been shown to be involved in Xenorhabdus virulence. We found that, in one treatment, the flhDC regulon has evolved rapidly, but that the changes we observed were not connected to virulence. All together, these results indicate that virulence is, in Xenorhabdus as in many other pathogens, a multifactorial trait. Being able to grow fast is one way to be virulent. But other ways exist which renders the evolution of virulence hard to predict

Les multiples facettes des inégalités écologiques

La notion d’inégalités environnementales se décline différemment selon les contextes culturels. Cette notion, telle qu’elle est apparue aux États-Unis, n’a de sens que dans une perspective d’action. Il s’agit de s’appuyer sur un environnement dégradé pour étayer les revendications de communautés ou d’ethnies défavorisées. En Europe, elle rejoint la notion, plus globale, de populations davantage exposées à des risques ou des contaminants, ou encore tributaires d’une faible qualité de leur milieu ambiant. Des politiques ou des situations environnementales et leurs implications sanitaires peuvent se conjuguer et renforcer des inégalités constatées sur le plan social.The notion of ecological inequalities is understood in very different ways depending on different cultural contexts. In the United States, where it has first developed, its only meaning is in an action perspective. The idea is to lean on degraded environmental conditions to strengthen the claims of unfavoured communities or ethnical groups. In Europe, it meets the more global notion of populations specifically exposed to risks or contaminating substances, or benefitting from weak quality surroundings. Policies, environmental situations and their health implications can meet and thus reinforce already identified social inequalities

Behavioral and Chemical Ecology of Marine Organisms with Respect to Tetrodotoxin

The behavioral and chemical ecology of marine organisms that possess tetrodotoxin (TTX) has not been comprehensively reviewed in one work to date. The evidence for TTX as an antipredator defense, as venom, as a sex pheromone, and as an attractant for TTX-sequestering organisms is discussed. Little is known about the adaptive value of TTX in microbial producers; thus, I focus on what is known about metazoans that are purported to accumulate TTX through diet or symbioses. Much of what has been proposed is inferred based on the anatomical distribution of TTX. Direct empirical tests of these hypotheses are absent in most cases

Chapitre 3. Réguler le climat à l’échelle locale : l’épreuve du temps

Selon les Nations Unies, les villes seraient à l’origine de 70 % des émissions de gaz à effet de serre. Ce chiffre suppose que l’on puisse dissocier ce qui est urbain du reste des établissements humains, dans un monde où les interdépendances entre modes de production et de consommation n’ont jamais été aussi fortes. Il implique aussi que l’on puisse assigner des pourcentages d’émissions à certains territoires, alors que l’énergie grise, incorporée dans les biens de consommation, l’équipement ..