perpetuate old inequalities in modern dress, rather than bring about "positive diversity", is a reiterated theme of these articles. Another common theme is the inherently problematic nature of a mercantile model invoking "competition" and "customers". The vexed issue of knowledge creation surfaces again in Mel Bartley's investigation of the relationship between research and policy in the case o...

Encroachment of riparian vegetation into regulated river channels exerts control over fluvial processes, channel morphology, and aquatic ecology. Reducing encroachment of terrestrial vegetation is an oft-cited objective of environmental flow recommendations, but there has been no systematic assessment of the evidence for and against the widely-accepted cause-and-effect mechanisms involved. We s...

Let A be a set of n > n0(ε) positive real numbers, all at least 1 apart. We show that, if δa,b and δ� a,b are arbitrary real numbers satisfying |δa,b| < n 1−ε a , and |δ � a,b| < n1−ε b , we have |{(a + δa,b)(b + δ� a,b) : a, b ∈ A}| + |A + A| � n1+ε/9 log n . – Dedicated to Mel Nathanson and Carl Pomerance on the occasion of their 65th birthdays

This book is a treat. A psychologist (Hurlburt) and a philosopher (Schwitzgebel) join forces to interview a young college graduate (Melanie). They ask Melanie what she experiences at randomly selected times. They debate what Melanie reports and what can be learned from it. They often disagree -but in a candid, humble, and open-minded way. Their imaginative and insightful dialogue, lightly edite...

The factors responsible for maintaining diverse groundcover plant communities of high conservation value in frequently burned wet pine savannas are poorly understood. While most management involves manipulating extrinsic factors important in maintaining species diversity (e.g., fire regimes), most ecological theory (e.g., niche theory and neutral theory) examines how traits exhibited by the spe...

Juniper encroachment into otherwise treeless shrub lands and grasslands is one of the most pronounced environmental changes observed in rangelands of western North America in recent decades. Most studies on juniper change are conducted over small areas, although encroachment is occurring throughout regions. Whether changes in juniper cover can be assessed over large areas with the use of long-t...