Studies of facilitation have primarily been limited to single mechanisms, species, or environments. We examined interacting mechanisms governing the facilitative effects of Pinus flexilis on two later successional understory species, Pseudotsuga menziesii and Ribes cereum, in different microhabitats and seasons at the ecotone between the Rocky Mountain forests and Great Plains grasslands in Mon...

Nociception allows for immediate reflex withdrawal whereas pain allows for longer-term protection via rapid learning. We examine here whether shore crabs placed within a brightly lit chamber learn to avoid one of two dark shelters when that shelter consistently results in shock. Crabs were randomly selected to receive shock or not prior to making their first choice and were tested again over 10...

OBJECTIVE To identify and evaluate coping strategies advocated by experienced animal shelter workers who directly engaged in euthanizing animals. DESIGN Cross-sectional study. SAMPLE POPULATION Animal shelters across the United States in which euthanasia was conducted (5 to 100 employees/shelter). PROCEDURES With the assistance of experts associated with the Humane Society of the United S...

Taxpayers shelter income from taxation both through illegal evasion and legal avoidance. This tax sheltering creates a difference between a household’s actual income and what it reports to the tax authorities. While tax sheltering is a central concern for designing a tax system, the private nature of this behavior complicates evaluating the magnitude and determinants of such behavior. In this p...

Virtual Globes have become a common platform for visualizing geographical data. The capability for customization, extensibility and the support of interaction with the visualized elements are some of the aspects to consider when selecting a Virtual Globe for visualization. For visualizing sensor data, aspects such as cardinality, the nature of the data and its temporal and spatial dimensions ha...

The technique of spatial modulating (“jittering”) an existing or newly created auditory alert along a virtual trajectory to improve its detection in a noisy environment is described. Threshold data from 14 participants were gathered as a function of spatial modulation rate (0, 1.6 and 3.3 Hz) of an avionics “wind sheer” alert (two successive 300 ms square waves) against a steady state backgroun...

Improvements in outdoor air quality that were achieved through the implementation of the Clean Air Act accentuate the quality of the indoor air as an important, if not dominant, factor in the determination of the total population exposure to air contaminants. A number of developments are adding important new determinants of indoor air quality. Energy conservation strategies require reductions i...

Taxes have major costs beyond the collected revenue: deadweight from distorted incentives, compliance and enforcement costs, etc. A simple market mechanism, the Equity Tax, avoids these problems for the trickiest cases: corporate, dividend, and capital gains taxes. It exploits the ability of the share prices to reflect the expected true annual return (as perceived by investors, not as defined b...