Academic Risk and Intellectual Adventure: Evidence from U.S. Honors Students at the University of Oxford

Many study abroad programs promise students self-knowledge through adventure. Those that involve intense study seem at first sight not to offer adventure nor to entail risky dislocation nor to offer new insights into self. However, evidence from study abroad students at the University of Oxford reveals that they describe intellectual endeavor as adventure, finding that their academic experiences pose risks, demand courage, and are the means through which they and their new surroundings accommodate one another. Oxford faculty encourage academic risk-taking by posing hard intellectual challenges, helping students find their own voice rather than summarizing the views of others, and having a grading system that emboldens students and rewards those who learn through their mistakes. Oxford faculty encourage students to take risks in their writing and dare to apply to good graduate schools but help them to submit carefully prepared applications to avoid unnecessary hazards. Home campus advisers can help honors students by recognizing those for whom study is adventure and by encouraging them to risk a rigorous intellectual study abroad program

Global stability and repulsion in autonomous Kolmogorov systems

Criteria are established for the global attraction, or global repulsion on a compact invariant set, of interior and boundary fixed points of Kolmogorov systems. In particular, the notions of diagonal stability and Split Lyapunov stability that have found wide success for Lotka-Volterra systems are extended for Kolmogorov systems. Several examples from theoretical ecology and evolutionary game theory are discussed to illustrate the results

Competitive Markets and Aggregate Information

This paper shows that a competitive market structure is identically efficient to a Walrasian rational expectations market when risk-averse agents base trades only on unbiased private signals. Because price reflects the complete set of market information, it is a sufficient statistic. The economic role of competing market makers is thus to aggregate information efficiently.Market Structure

Does aspirin detract from the benefits of mineralocorticoid receptor antagonists in patients with heart failure and a reduced left ventricular ejection fraction? Probably!

No abstract available

Nonmonotone invariant manifolds in the Nagylaki–Crow model

We use a change of dynamical variables to prove, subject to certain conditions on the parameters, that a nonmonotone invariant manifold exists and is the graph of a convex function for the planar Nagylaki–Crow fertility–mortality model from population genetics with n = 2. Our results are obtained without the common assumption that fertilities or death rates are additive, and are not restricted to the case that the model is competitive in the new coordinates. We also provide numerical examples demonstrating that the manifold need not be the graph of a convex function, smooth, unique or globally attracting, and that the model exhibits a sequence of nonmonotone manifolds similar to those studied by Hirsch for competitive Kolmogorov systems (Hirsch 1988)

Convexity of the carrying simplex for discrete-time planar competitive Kolmogorov systems

We consider the geometry of carrying simplices of discrete-time competitive Kolmogorov systems. An existence theorem for the carrying simplex based upon the Hadamard graph transform is developed, and conditions for when the transform yields a sequence of convex or concave graphs are determined. As an application it is shown that the planar Leslie-Gower model has a carrying simplex that is convex or concave