1,004 research outputs found
Intraperitoneal administration of CNTF ameliorates the clinical course of EAE via protection of oligodendrocytes and axons
No full textThe Metaphysics of Individuality and the Sciences
No full textThis chapter has a twofold aim. First, to look at the debate about identity and individuality in nonrelativistic quantum mechanics and offer a limited defense of the view according to which identity facts are primitive in that domain. Second, to contribute to the clarification of the relationship between science and metaphysics, in particular with respect to what a proper “naturalistic” methodology should and should not be taken to entail as far as the theme of individuality is concerned. The guiding idea is that taking identity and individuality facts as basic is not necessarily in conflict with naturalism. The overall picture that emerges, however, is that of a “pluralistic” approach, whereby different scientific domains and theories are likely to allow, and in fact to ask for, different forms of individuality
Physicochemical characterization of mixed RuO2-SnO2 solid solutions
No full textMixed SnO2-RuO2 oxides were prepared by high-energy mechanical alloying of various proportions of pure SnO2 and RuO2 powders. The physicochemical characterization of the resulting materials was conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical surface analysis. It is shown through XRD analysis that a single-phase (tetragonal) (Sn-Ru)O-2 solid solution is formed over the whole composition range, in which the Sn4+ and Ru4+ ions share the same cationic sub-lattice of the rutile-like structure. The surface of the compounds was analyzed by XPS and shows a deficit of Ru atoms, with [Ru](surface) = 36 at. % for an equimolar SnO2-RuO2 concentration in the bulk of the sample. In the case of pure nanocrystalline RuO2, the total surface charge, q(T)*, the most easily accessible surface charge, q(o)*, and the less easily accessible surface charge, q(1)*, are 35.3, 29.0, and 6.3 mC cm(-2) mg(-1), respectively. These surface charges vary linearly with the Ru content at the surface of the electrode, indicating that the surface electrochemical properties of the compounds are dominated by the redox properties of the Ru4+ cation. The ratio q(o)*/q(T)* is close to 0.8 and independent of the surface composition, suggesting that all compounds have a similar morphology
Dimensional comparison theory: New models, new methods, new insights
No full textMöller J, Wolff F, Helm F. Dimensional comparison theory: New models, new methods, new insights. In: Dicke T, Guay F, Marsh HW, Craven RG, McInerney DM, eds. Self: A multidisciplinary concept. Charlotte, NC: Information Age Publishing; 2021: 31-57
Role of tRNA fragments in islet macrophage activation and in the crosstalk with β-cells during obesity
No full textIslet-resident macrophages (Mφs) play a key role in pancreatic islet homeostasis but their activation in obesity results in β-cell dysfunction. This activation is likely to be elicited by modulatory molecules highly sensitive to environmental changes. The pool of transfer RNAs (tRNAs) is strictly regulated by nutrient availability and under stress conditions tRNAs can be cleaved, generating fragments (tRFs) with regulatory functions. Moreover, tRFs play a crucial role in extracellular vesicles (EVs)-mediated cell-to-cell crosstalk. The aim of the present work was to determine the impact of obesity on the tRF profile of islet Mφs and to investigate the role of these RNAs in Mφ activation and in the crosstalk with β-cells.
Islet Mφs and β-cells were isolated from obese db/db and lean wild type mice. Small RNA sequencing identified 15 modulated tRFs (≥1.5-fold change, p≤0.05, n=4) in db/db islet Mφs. To assess their role in Mφ activation, we compared the tRF profile of db/db islet Mφs to that of bone marrow derived Mφs (BMDMs), polarized into M1 pro- and M2 anti-inflammatory Mφs. Interestingly, 7 of the tRFs upregulated in db/db islet Mφs were enriched in M2 BMDMs (≥1.5-fold change, p≤0.05, n=3). Inhibition of one of these fragments, 5’tRFGlu(CTC), led to profound transcriptomic changes in both M1 and M2 BMDMs (n=3), with a preferential impact on genes involved in T-cell stimulation and in acute immune responses. Among the tRFs upregulated in obese islet Mφs, 5’tRFGlu(CTC), 5’tRFGly(GCC) and 5’tRFAsp(GTC) were also increased in β-cells of db/db mice and were abundant in EVs released by M2 BMDMs, suggesting a possible role in the crosstalk between islet cells.
Our data suggest that tRFs may act as key modulators of Mφs activation and that obesity induces an upregulation of anti-inflammatory tRFs in islet Mφs. RNA labelling and EVs transfer techniques are currently being used to investigate the contribution of tRFs in Mφ-β-cell crosstalk
Conceptual Foundations of Yang–Mills Theories
No full textEssay review of Gauging What’s Real: The Conceptual Foundations of Contemporary Gauge Theories R. Healey. Oxford University Press (2007). To be published in the Studies in History and Philosophy of Modern Physics, 39(3):687-693, 2008
Succès et difficultés de la mise en œuvre des plans d'action de lutte contre les changements climatiques du gouvernement québécois 2006-2012 et 2013-2020
No full textLes changements climatiques « reflètent ce que la science dit et ce dont la politique tient de plus en plus compte » (Ouranos, 2015). La présente thèse consiste à documenter la mise en oeuvre des deux derniers plans de lutte contre le réchauffement du climat préparés par le gouvernement québécois, soit Le Québec et les changements climatiques : un défi pour l’avenir. Plan d’action 2006-2012, ainsi que Le Québec en action. Vert 2020. Plan d’action 2013-2020 sur les changements climatiques. Au croisement des travaux en sociologie de l’action publique (Matland, 1995 ; Kübler et Maillard, 2009), des perspectives théoriques de la modernisation écologique et de sa tradition d’étude des politiques publiques (Béal, 2016), comment se déroule cette mise en oeuvre, d’une part, et pourquoi y a-t-il des succès et des difficultés, d’autre part? Même si le Québec pénètre de plain-pied dans la société à faible carbone, grâce à son tandem énergétique éolien-hydroélectrique, la lutte contre les changements climatiques représente un défi considérable qu’il a accepté de relever en se dotant d’une cible ambitieuse. Le PACC 2006-2012 a fait avancer les choses, mais beaucoup reste à faire et il y a un bémol : le PACC 2013-2020 permettra-t-il d’atteindre sa cible de réduction de 20 % des émissions de GES par rapport au seuil de 1990 (Gouvernement du Québec, 2012a, p. I) ? Au 31 mars 2016, on constate la sous-utilisation du PACC 2013-2020, car à peine 22 % du budget prévu se trouve entamé (MDDELCC, 2017a, p. 46). Les baisses d’émissions de GES et l’adaptation aux changements climatiques se font attendre. La thèse s’inscrit dans le cadre théorique de la modernisation écologique (Huber, 1982 ; Spaargaren et Mol, 1992 ; Hajer, 1995 ; Jänicke, 1995 ; Mol, 2003 ; Christoff, 2009 ; Spaargaren et al., 2009 ; Toke, 2011), que plusieurs dépeignent comme la version sociologique du projet du développement durable, centrée sur les acteurs gouvernementaux et industriels, puis la société civile (Buttel, 2003). Par ailleurs, source de richesse analytique et compréhensive qui échappe aux études quantitatives, la méthode privilégiée est l’entretien semi-dirigé (Fortin, 2013) auprès des maîtres d’oeuvre de ces PACC, des fonctionnaires pour la plupart, ainsi que l’analyse de contenu (Leray, 2008) pour le traitement des données. Mais les limites évidentes des indicateurs et de la méthode qualitative impliquent une vérification partielle des hypothèses. En outre, la thèse de la modernisation écologique se situe dans le long terme et a besoin de temps pour se soumettre à une vérification empirique (Guay, 2018)...Climate change represents what science says and what politics is increasingly taking into account (Ouranos, 2015). The purpose of this thesis aims to document the implementation of the two last action plans against global warming, prepared by the Governement of Québec, namely Le Québec et les changements climatiques : un défi pour l’avenir. Plan d’action 2006-2012, and Le Québec en action. Vert 2020. Plan d’action 2013-2020 sur les changements climatiques. At the junction between the analysis of public action (Matland, 1995 ; Kübler et Maillard, 2009) and the theoretical framework of the ecological modernization and its tradition of the public policies sociology (Béal, 2016), this thesis tries to answer two questions : how is the implementation carried out and why are there successes and difficulties to this adoption? Québec gets its foot in a low-carbon society, through the wind and hydroelectric energy tandem. However, fighting against climate change represents a major challenge, which Québec has accepted with an ambitious target. The PACC 2006-2012 got some basis implemented, but there remains a lot to do and outcomes remain unknown : will the PACC 2013-2020 achieve its greenhouse gas emissions reduction target of 20 % below the line of 1990 (Gouvernement du Québec, 2012a, p. I) ? At march 31, 2016, one notes the under-implementation of the PACC 2013-2020, since 22 % only of the planned budget had already been spent (MDDELCC, 2017a, p. 46). Greenhouse gas emissions reduction and climate change adaptation are lagging behind projections. The thesis fits into the theoretical framework of the ecological modernization (Huber, 1982 ; Spaargaren et Mol, 1992 ; Hajer, 1995 ; Jänicke, 1995 ; Mol, 2003 ; Christoff, 2009 ; Spaargaren et al., 2009 ; Toke, 2011), which many people present as the sociological version of the sustainable development project, focused on state and industrial actors, then the civil society (Buttel, 2003). Moreover, source of analytical and comprehensive wealth, which escapes from quantitative studies, the preferred method is semi-directive interviews (Fortin, 2013) with the supervisors of the two PACC, public authorities for the greater part, as well as content analysis (Leray, 2008) for data treatment. But the obvious limitations of the indicators and the qualitative method involve a partial validation of the hypotheses. Otherwise, the ecological modernization thesis takes place in a long-term perspective and requires time for an empirical testing (Guay, 2018)..
An Econometric Analysis of Trends in Research Joint Venture Activity.
No full textEdith Penrose was one of the first scholars to point out that firms may need to rely on research joint ventures (RJVs) to acquire access to resources that can help them achieve and sustain a competitive advantage. We estimate an econometric model of the propensity of firms to disclose their intension to engage in RJVs, in order to explain the recent precipitous decline in RJVs filed with the U.S. Department of Justice. We find that RJV activity is inversely related to the competitive position of U.S. firms in global high-technology industries and that the establishment of the U.S. Commerce Department's Advanced Technology Program (ATP) induced a structural change in the propensity of firms to engage in RJVs. Thus, two factors may explain the recent downturn in RJV filings: a substantial improvement in U.S. global performance in high-technology markets and a sharp decline in ATP funding.
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Uranium swelling in N-Reactor (PT-NR-4, Sup. A, Report No. 1)
No full textFive monitor columns, containing some pre-irradiation weighed inner and outer fuel elements, were discharged under authorization of PT-NR-4, Sup A at tube average exposures in the range from 1554 to 1631 MWD/T. Uranium swelling values have been calculated from post-irradiation weight measurements and these swelling values have been compared with those swelling values obtained in the KER loop tests. There is acceptable agreement between KER and NPR results for swelling of inner uranium; there is acceptable agreement for outer fuel elements at higher exposures but ends-of-the-column elements (i.e. low-exposure values) are not in agreement. The current swelling values have been extrapolated to determine the tube-average exposure that will result in outer clad strains of one percent. At this conservative value of clad strain, one can predict entirely adequate performance of outer fuel elements to tube average exposures of 2200 MWD/T and inner fuel elements to 2700 MWD/T tube average exposure. Elements that will soon be discharged at tube average exposures ranging from 1900 to 2100 MWD/T, can be evaluated for swelling during the next outage and a much better prediction can be made on the relation of exposure vs swelling and hence exposure vs fuel element integrity. The continuing objective of this production test remains as the determination of fuel element performance vs exposure
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