Dominance Over N

Abstract.This paper provides an overview of the b-dominance order over the natural numbers, N, using the base b expansion of natural numbers. The b-dominance order is an accessible partially-ordered set that is less complex than the divisor relation but more complex than ≤; thus, it supplies a good medium through which an undergraduate can be exposed to the subject of order theory. Here we discuss many ideas in order theory, including the Poincaré polynomial and the Möbius function. Acknowledgements: The authors thank the M.J. Murdock Charitable Trust and the Pacific Lutheran University Division of Natural Sciences for their generous support. They would also like to extend their thanks to Dr. Tom Edgar for the project idea and all his help throughout their summer program. Page 24 RHIT Undergrad. Math. J., Vol. 14, no. 2

Using xenon as a probe for dioxygen-binding sites in copper amine oxidases

Potential dioxygen-binding sites in three Cu amine oxidases have been investigated by recording X-ray diffraction data at 1.7-2.2 Å resolution for crystals under a high pressure of xenon gas. Electron-density difference maps and crystallographic refinement provide unequivocal evidence for a number of Xe-binding sites in each enzyme. Only one of these sites is present in all three Cu amine oxidases studied. Structural changes elsewhere in the protein molecules are insignificant. The results illustrate the use of xenon as a probe for cavities, in which a protein may accommodate a dioxygen molecule. The finding of a potential dioxygen-binding cavity close to the active site of Cu amine oxidases may be relevant to the function of the enzymes, since the formation of a transient protein-dioxygen complex is a likely step in the catalytic mechanism. No evidence was found for xenon binding in a region of the molecule that was previously identified in two other Cu amine oxidases as a potential transient dioxygen-binding site. © 2004 Elsevier Ltd. All rights reserved.Link_to_subscribed_fulltex

Norms from the periphery: tracing the rise of the common but differentiated principle in international environmental politics

Over the last three decades, constructivist scholars of international relations have created a rich body of literature on the influence of global norms. Until recently, the vast majority of that work focused on norms originating in the developed world and neglected the ideational impact of developing countries. This article confronts this oversight in the literature by tracing the rise of the “common but differentiated responsibility” (CBDR) norm in international environmental politics. The CBDR principle traces its origins to the developing world and today it is part of the framework principles of international environmental agreements. Thus, it represents a global norm promoted by, rather than diffused to, the developing world. In the process of tracing this norm’s rise, this article generates a set of hypotheses about the conditions under which developing countries create global norms