Islip, Town of (M2007-284) and International Brotherhood of Teamsters, Local 237

In the Matter of the Impasse between Local 237, International Brotherhood of Teamsters and Town of Islip, New York. Case No. M2007-284. Before: Robert L. Douglas, Fact Finder

Islip, Town of (M2007-283) and International Brotherhood of Teamsters, Local 237

In the Matter of the Impasse between Local 237, International Brotherhood of Teamsters and Town of Islip, New York. Case No. M2007-283. Before: Robert L. Douglas, Fact Finder

Nassau Community College and Adjunct Faculty Association of Nassau Community College

In the matter of the fact-finding between Nassau Community College, employer, and the Adjunct Faculty Association of Nassau Community College, union. PERB case no. M2010-152. Before: Robert L. Douglas, fact finder

Flight Performance and Competitive Displacement of Hummingbirds across Elevational Gradients

Hummingbirds, with their impressive flight ability and competitive aerial contests, make ideal candidates for applying a mechanistic approach to studying community structure. Because flight costs are influenced by abiotic factors that change systematically with altitude, elevational gradients provide natural experiments for hummingbird flight ecology. Prior attempts relied on wing disc loading (WDL) as a morphological surrogate for flight performance, but recent analyses indicate this variable does not influence either territorial behavior or competitive ability. Aerodynamic power, by contrast, can be derived from direct measurements of performance and, like WDL, declines across elevations. Here, I demonstrate for a diverse community of Andean hummingbirds that burst aerodynamic power is associated with territorial behavior. Along a second elevational gradient in Colorado, I tested for correlated changes in aerodynamic power and competitive ability in two territorial hummingbirds. This behavioral analysis revealed that short-winged Selasphorus rufus males are dominant over long-winged Selasphorus platycercus males at low elevations but that the roles are reversed at higher elevations. Several lines of evidence support the hypothesis that the burst rather than sustained aerodynamic performance mediates competitive ability at high elevation. A minimum value for burst power may be required for successful competition, but other maneuverability features gain importance when all competitors have sufficient muscle power, as occurs at low elevations

History, Culture, and Trade: A Dynamic Gravity Approach

What determines trade patterns? Habit persistence in consumer tastes and learning-by-doing in production imply that history and culture matter. Deriving a dynamic gravity equation from a simple model, it is shown that cultural similarity is a product of history, so that trade patterns are a function of bilateral GDP, current trade costs, and the past history of trade costs. Using a trade data set which spans from 1870 to 2000, I demonstrate that many gravity variables operate via lagged trade, that historical trade shocks matter, and that trade patterns are persistent, even across centuries.Dynamic Gravity Equation, Endogenous Preferences, Habit Persistence, Learning By-Doing.