La théorie des éléments de Christophorus Clavius et l'idée du globe terraqué

Christophorus Clavius' Theory of the Elements and the Idea of the Terraqueous Globe. The need to reconcile Aristotle's theory of elementary spheres with the evidence of earth above sea level – the so‐called ‘terra firma’ – induced an important conceptual shift. As a consequence anti‐Aristotelian arguments were brought to the fore in order to be incorporated into the very same Aristotelian tradition. The German Jesuit Christophorus Clavius played a momentous role in this process. He introduced the idea of the terraqueous globe into the Scholastic cosmology, modifying the logical frame of Aristotelian physics. The present work analyses Clavius' theory as well as the procedures he considers to reach his purpose. He used a combinatorial approach to study the relations occurring between the four elements – earth, water, air and fire – and analysed their relations from a physical perspective, proposing a possible structure of the sublunary world.     

La frontière asymétrique : Franco‐Ontariens et Anglo‐Québécois dans la région de la capitale nationale

The francophone and anglophone minorities of Gatineau‐Ottawa appear to benefit from a privileged location. Living very close to their respective majorities, they simply have to cross the border in order to access resources to live in their own language and share their culture. However, a qualitative analysis of the discourse by Anglo‐Quebeckers and Franco‐Ontarians about their everyday life in the Nation's Capital Region shows that the border has more complex and often contradictory effects. In this article, we focus our attention on four particular manifestations of the border: (1) the border is transparent so that one can cross the Ottawa River without hindrance in certain contexts yet rather opaque in others; (2) one may transcend minority status through the strategic use of the border; (3) it creates a multi‐topic imaginary geography in which the border itself often becomes mobile; and (4) finally, the border can act as a mirror when the cross‐cultural intermixing it allows causes the Anglo‐Quebeckers and Franco‐Ontarians to question their identities, a questioning which would not be as intense in the absence of the border. The comparison of these two minorities makes it possible to highlight the asymmetrical nature of the effects of the border on their everyday life, identities, and sense of belonging.     

Variabilité et fréquence des cycles de gel‐dégel dans la région de Québec, 1977–2006

Freeze‐thaw cycles are most common at the beginning or near the end of the winter season. These cycles have various effects on the ecosystems of Eastern Canada, affecting both biotic and abiotic components of temperate cold environments. Using air temperature minima and maxima from four meteorological stations close to Québec City, we determined the frequency of daily freeze‐thaw cycles for the last 30 years. The results show no significant increase in the number of freeze‐thaw cycles despite a small increase in air temperature. Polynomial curves describing the relationship between mean air temperatures and the number of freeze‐thaw cycles were calculated. Based on these equations and anticipating a climate change scenario, we projected future freeze‐thaw cycles. Assuming a 5 °C increase in mean air temperatures by 2100, we estimated that the number of days with a freeze‐thaw cycle could increase by approximately 20 days per winter. The increase in the number of such cycles will be concentrated during the coldest months of the winter (January and February).