285 research outputs found

    Urban carbon politics : civil society, policymaking and the transition to carbon-neutral cities

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    Les villes sont au cœur de l’urgence climatique et elles sont fondamentales pour accélérer la transition vers un monde ‘carboneutre’. Aujourd'hui, les municipalités ne sont plus que de simples fournisseurs de services; elles doivent catalyser des transitions urbaines durables. La réalisation de villes durables est un défi extrêmement complexe car les exigences et le contexte changent constamment, plusieurs interdépendances dynamiques jouent un rôle crucial et il y a peu de possibilités d'apprendre par essais et erreurs. La signification même de ce qu'est une ‘ville durable’ est très vaste et basé sur des débats sociétaux très contesté. Bien que la société civile et les ‘entrepreneurs politiques’ jouent déjà un rôle important dans le contexte urbain et façonnent considérablement la façon dont les gens perçoivent la crise climatique; on ne sait pas encore comment ils peuvent répondre à des défis ‘super vicieux’ telle que l’urgence climatique dans le contexte urbain et comment les acteurs de la société civile peuvent contribuer à accélérer la transition vers des villes carboneutre. Souvent caractérisés par leur désir de maintenir une certaine indépendance vis-à-vis des institutions publiques, la question est de savoir comment les acteurs de la société civile occupent différentes positions vis-à-vis les institutions qu'ils cherchent à transformer, et les effets que ces différentes positions ont sur leurs contributions aux transitions urbaines durables. Si de nombreuses recherches ont été menées sur les entrepreneurs politiques ‘puissants’ associés aux systèmes dominant de nos sociétés, les ‘régimes’, on en sait beaucoup moins sur les entrepreneurs politiques issus de la société civile. Il est nécessaire d'améliorer notre compréhension de la manière dont ces derniers encadrent l'urgence climatique dans le contexte urbain et de la manière dont ils mettent à l'échelle leurs actions pour parvenir à une profonde et rapide décarbonisation du contexte urbain. La question de la thèse est: Comment est-ce que les entrepreneurs politiques issue de la société civile encadrent le problème de l'urgence climatique et comment mettent-ils à l'échelle leurs actions pour rapidement décarboniser le contexte urbain et accélérer la transition vers des villes carboneutres? La recherche est une étude de cas unique longitudinale et approfondie, sur une période cinq ans (2015-2020), qui reconstruit l'émergence de la Coalition climat Montréal; un organisme à but non lucratif qui vise à ce que Montréal atteigne la carboneutralité d'ici 2042, année du 400e anniversaire de la ville. La thèse mobilise le champ de recherche des théories de transition (Transition Theory) et des études en politiques publiques, pour mieux comprendre les efforts, actions et stratégies de la Coalition climat Montréal depuis sa création, au moment de l'accord de Paris COP21 de 2015. Basé sur un cadre théorique qui revisite la perspective multi-acteurs (MaP), l'accent est mis sur une meilleure compréhension des ‘actes’ des acteurs de la société civile qui visent à ‘gagner’ dans le champ d’action stratégique de la carboneutralité dans lequel ils opèrent à Montréal. La recherche met en relief leurs stratégies, comment elles ont émergé et se sont structuré à travers les années, ainsi que leurs capacités à influencer les processus d'élaboration des politiques publiques urbaines pour la carboneutralité et les processus de transition urbaine en général. Une attention particulière est portée au contexte; examinant comment (et dans quelle mesure) la nature ‘polycentrique’ de la gouvernance climatique et les caractéristiques des institutions municipales locales facilitent et contraignent les efforts des acteurs. Adoptant une stratégie d'analyse processuelle et abductive, la recherche révèle les stratégies entrepreneuriales des acteurs de la société civile qui cherchent à perturber le statu quo en faisant progresser des politiques publiques ambitieuses pour la carboneutralité urbaines, et le potentiel que de telles actions au niveau micro puissent provoquer des changements au niveau macro. Adoptant le rôle engagé d'un ‘chercheur-activiste’, j'explore les formes d'entrepreneuriat qui ‘tiennent tête’ aux acteurs et secteurs les plus puissant de notre société; enrichissant notre compréhension du rôle actif que certains acteurs de la société civile jouent afin d’ancrer la carboneutralité dans l’agenda des politiques publiques. Ce faisant, la thèse contribue à enrichir une notre compréhension nuancée de l’influence que certains acteurs de la société civiles ont sur la direction et la vitesse des transitions urbaine pour la carboneutralité, et la durabilité en général. D'un point de vue pratique, la recherche contribue à mieux informer les actions et les stratégies de la société civile concerné par l’urgence climatique, ainsi que le types de processus de politique publique climatique au niveau municipal qui peuvent effectivement accélérer les transitions urbaines vers la carboneutralité; contribuant au développement de ‘sagesse pratique’ pour l’action climatique locale. Fondamentalement, le potentiel des villes n'est pas de tout simplement adopter les cadres politiques internationaux, mais aussi de montrer comment d'autres voies alternatives venant des ‘marges’ sont possibles. Impliquant un important potentiel émancipateur, la ville en tant que site d'expérimentation socio-écologique radicale doit être encouragée et catalysée, plutôt que d’être simplement laissé au mirage d'une ‘économie verte’.Cities are at the heart of climate emergency, and they’re fundamental if we are to accelerate the transition to a ‘carbon-neutral’ world. Today, municipal governments are no longer just service providers; they need to be catalysts for sustainability transitions. Achieving sustainable cities is a vicious problem as requirements are always changing, complex and dynamic interdependencies play a crucial role, there is no absolute right or wrong solution, and little opportunities exist to learn by trial and error. The very meaning of what is a ‘sustainable city’ is a very contested societal debate. Although civil society and policy entrepreneurs are already central actors in the urban context and considerably influence the way by which people think about the climate crisis; it’s not clear yet how they can respond to challenges of such magnitude as the climate emergency, and how they can contribute to accelerating the transition to a carbon-neutral world. While often characterized by their desire to sustain a certain form of independence from governments, it’s not yet clear how civil society actors occupy different positions vis-à-vis the institutions they try to transform, and the effects that these diverse positions have on their contributions to urban sustainability transitions. For instance, while much has been researched about powerful ‘regime’ policy entrepreneurs, much less is known about policy entrepreneurs emanating from civil society. There’s a need to enhance our understanding of how such actors frame the climate emergency in the urban context and how they scale their actions in order to achieve deep urban decarbonisation. The thesis question is: How do civil society’s policy entrepreneurs frame the climate emergency problem and scale their actions to quickly decarbonise the urban context and accelerate the transition to carbon-neutral cities? The research is a five-year in-depth longitudinal single case study that reconstructs the emergence of the Montreal Climate Coalition; a non-profit organization that aims for Montreal to achieve carbon-neutrality by 2042, year of the city's 400th anniversary. The thesis mobilizes the research fields of sustainability transitions and public policy studies to better understand the Coalition’s efforts, actions and strategies since the 2015 COP21 Paris agreement. Based on a conceptualised theoretical framework that revisits the Multi-actor perspective (MaP), the focus is to shed light on the ‘acts’ of civil society actors that aim to ‘punch above their weight’ in the strategic urban carbon-neutrality action field in which they operate, the way that they develop and deploy their strategies, and how this contributes to (and shapes) policymaking processes for urban carbon-neutrality; as well as overall urban sustainability transition dynamics. Particular attention is paid to context, examining how (and to what extent) the ‘polycentric’ nature of climate governance and local municipal institutions facilitate and/or frustrate the efforts of actors. Adopting a processual, abductive and transformation-based strategy of analysis that aims to generate ‘practical wisdom’ knowledge for urban sustainability science, the research reveals civil society’s entrepreneuring strategies that seek to disrupt the status quo by advancing ambitious urban carbon-neutrality policies, as well as the potential for such micro-level acts to bring about changes at the macro level. In this way, and by taking on the role of an engaged climate ‘researcher-activist’, I explore the forms of entrepreneurship that stand up to powerful actors and sectors in our society, enriching our knowledge of the active role that some civil society actors (can) play in setting the urban carbon-neutrality agenda. In doing so, the thesis contributes to enriching an ever more nuanced understanding of the influence that civil society actors can have on the speed and direction of urban sustainability transitions. From a practice-based perspective, the research contributes to better informing civil society’ actions and strategies, as well as the kind of municipal climate policy processes that can catalyze deep decarbonisation and accelerate the urgently needed urban sustainability transitions to carbon-neutral cities. Fundamentally, the potential of cities is not just to simply associate themselves with current international climate frameworks; but more critically, to show how other alternative pathways from the fringes of society are possible. Involving considerable emancipatory potential, the city as a site of radical socio-ecological experimentation needs to be fostered, and not just handed over to the mirage of a ‘green economy’

    Designing a robust production system for erratic demand environments.

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    Production systems must have the right type of material in the right quantities when required for production. They must minimize the work in progress while ensuring no stock-outstock-out occurs. While these twin opposing goals are achievable when demand is stable, they are difficult to realize under an erratic demand pattern. This dissertation aims to develop a production system that can meet erratic demands with minimal costs or errors. After a detailed introduction to the problem considered, we review the relevant literature. We then conduct a numerical analysis of current production systems, identify their deficiencies, and then present our solution to address these deficiencies via the ARK (Automated Replenishment System) technique. This technique is applied to a real-world problem at Methode Engineering ©. We conclude by detailing the scientific benefit of our technique and proposing ideas for future research

    Microglial Scavenger Receptors and Their Roles in the Pathogenesis of Alzheimer's Disease

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    Alzheimer's disease (AD) is increasing in prevalence with the aging population. Deposition of amyloid-β (Aβ) in the brain of AD patients is a hallmark of the disease and is associated with increased microglial numbers and activation state. The interaction of microglia with Aβ appears to play a dichotomous role in AD pathogenesis. On one hand, microglia can phagocytose and clear Aβ, but binding of microglia to Aβ also increases their ability to produce inflammatory cytokines, chemokines, and neurotoxic reactive oxygen species (ROS). Scavenger receptors, a group of evolutionally conserved proteins expressed on the surface of microglia act as receptors for Aβ. Of particular interest are SCARA-1 (scavenger receptor A-1), CD36, and RAGE (receptor for advanced glycation end products). SCARA-1 appears to be involved in the clearance of Aβ, while CD36 and RAGE are involved in activation of microglia by Aβ. In this review, we discuss the roles of various scavenger receptors in the interaction of microglia with Aβ and propose that these receptors play complementary, nonredundant functions in the development of AD pathology. We also discuss potential therapeutic applications for these receptors in AD

    Fibrils from Designed Non-Amyloid-Related Synthetic Peptides Induce AA-Amyloidosis during Inflammation in an Animal Model

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    Background: Mouse AA-amyloidosis is a transmissible disease by a prion-like mechanism where amyloid fibrils act by seeding. Synthetic peptides with no amyloid relationship can assemble into amyloid-like fibrils and these may have seeding capacity for amyloid proteins. Principal Findings: Several synthetic peptides, designed for nanotechnology, have been examined for their ability to produce fibrils with Congo red affinity and concomitant green birefringence, affinity for thioflavin S and to accelerate AAamyloidosis in mice. It is shown that some amphiphilic fibril-forming peptides not only produced Congo red birefringence and showed affinity for thioflavin S, but they also shortened the lag phase for systemic AA-amyloidosis in mice when they were given intravenously at the time of inflammatory induction with silver nitride. Peptides, not forming amyloid-like fibrils, did not have such properties. Conclusions: These observations should caution researchers and those who work with synthetic peptides and thei

    Combining several thermal indices to generate a unique heat comfort assessment methodology

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    Purpose: The proposed methodology hopes to provide a systematic multi-disciplinary approach to assess the thermal environment while minimizing unneeded efforts. Design/methodology/approach: Different factors affect the perception of the human thermal experience: metabolic rate (biology), surrounding temperatures (heat balance and environmental factors) and cognitive treatment (physiology).This paper proposes a combination of different multidisciplinary variables to generate a unique heat comfort assessment methodology. The variables at stake are physiological, biological, and environmental. Our own heat analysis is thoroughly presented and all relevant equations are described. Findings: Most companies are oblivious about potential dangers of heat stress accidents and thus about methods to monitor and prevent them. This methodology enables the company or the concerned individual to conduct a preliminary assessment with minimal wasted resources and time in unnecessary steps whilst providing a guideline for a detailed study with minimal error rates if needed. More so, thermal comfort is an integral part of sound ergonomics practices, which in turn are decisive for the success of any lean six sigma initiative. Research limitations/implications: This methodology requires several full implementations to finalize its design. Originality/value: Most used heat comfort models are inherently uncertain and tiresome to apply. An extensive literature review confirms the need for a uniform assessment methodology that combines the different thermal comfort models such as the Fanger comfort model (PMV, PPD) and WGBT since high error rates coupled with tiresome calculations often hinder the thermal assessment process.Peer Reviewe

    Experimental Diabetes Mellitus Exacerbates Tau Pathology in a Transgenic Mouse Model of Alzheimer's Disease

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    Diabetes mellitus (DM) is characterized by hyperglycemia caused by a lack of insulin, insulin resistance, or both. There is increasing evidence that insulin also plays a role in Alzheimer's disease (AD) as it is involved in the metabolism of β-amyloid (Aβ) and tau, two proteins that form Aβ plaques and neurofibrillary tangles (NFTs), respectively, the hallmark lesions in AD. Here, we examined the effects of experimental DM on a pre-existing tau pathology in the pR5 transgenic mouse strain that is characterized by NFTs. pR5 mice express P301L mutant human tau that is associated with dementia. Experimental DM was induced by administration of streptozotocin (STZ), which causes insulin deficiency. We determined phosphorylation of tau, using immunohistochemistry and Western blotting. Solubility of tau was determined upon extraction with sarkosyl and formic acid, and Gallyas silver staining was employed to reveal NFTs. Insulin depletion by STZ administration in six months-old non-transgenic mice causes increased tau phosphorylation, without its deposition or NFT formation. In contrast, in pR5 mice this results in massive deposition of hyperphosphorylated, insoluble tau. Furthermore, they develop a pronounced tau-histopathology, including NFTs at this early age, while the pathology in sham-treated pR5 mice is moderate. Whereas experimental DM did not result in deposition of hyperphosphorylated tau in non-transgenic mice, a predisposition to develop a tau pathology in young pR5 mice was both sufficient and necessary to exacerbate tau deposition and NFT formation. Hence, DM can accelerate onset and increase severity of disease in individuals with a predisposition to developing tau pathology

    Probing Vibrationally Mediated Ultrafast Excited-state Reaction Dynamics With Multireference (caspt2) Trajectories

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    Excited-state trajectories computed at the complete active space second-order perturbation theory (CASPT2) reveal how vibrational excitation controls the molecular approach to the intersection space that drives the photodissociation of a prototypical halogenated methyl radical, namely CF2I. Translating the Franck-Condon structure along the ground-state CASPT2 vibrational modes in this system followed by propagating the displaced structures in the first excited doublet state simulates specific vibrational excitations and vibrationally mediated dynamics, respectively. Three distinct situations are encountered: the trajectories (i) converge to an energetically flat segment of the intersection space, (ii) locate a segment of the intersection space, and (iii) access a region where the intersection space degeneracy is lifted to form a ridge of avoided crossings. The computational protocol documented herein can be used as a tool to design control strategies based on selective excitation of vibrational modes, including adaptive feedback schemes using coherent light sources

    Roles of Microglial and Monocyte Chemokines and Their Receptors in Regulating Alzheimer's Disease-Associated Amyloid-β and Tau Pathologies

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    Chemokines and their receptors have been shown to affect amyloid-β (Aβ) and tau pathologies in mouse models of Alzheimer's disease (AD) by regulating microglia and monocyte-associated neuroinflammation, microglial movement and monocyte recruitment into the brain. These cells in turn can promote and mediate Aβ phagocytosis and degradation and tau phosphorylation. In this review we discuss published work in this field in mouse models of AD and review what is known about the contributions of microglial and monocyte chemokines and their receptors to amyloid and tau pathologies. We focus on the roles of the chemokine/chemokine receptor pairs CCL2/CCR2, CX3CL1/CX3CR1, CCL5/CCR5, CXCL10/CXCR3 and CXCL1/CXCR2, highlighting important knowledge gaps in this field. A full understanding of the functions of chemokines and their receptors in AD may guide the development of novel immunotherapies for this devastating disease
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