This experiment tests the effects of early canopy development by asexually regenerating aspen (Populus tremuloides Michx.) on conifer recruitment after fire in central Alaska. The establishment and growth of three conifer species were observed in response to aboveground removal of aspen suckers for three seasons after burning by wildfire. Of the three species, Pinus contorta Dougl. ex Loud. had...

Wolves (Canis lupus) were reintroduced to Yellowstone National Park in 1995–1996. We present data on a recent trophic cascade involving wolves, elk (Cervus elaphus), and aspen (Populus tremuloides) in Yellowstone’s northern winter range that documents the first significant growth of aspen in over half a century. Results indicate reduced browsing and increased heights of young aspen during the l...

Human exposure research has consistently shown that, for most volatile organic compounds (VOCs), personal exposures are vastly different from outdoor air concentrations. Therefore, risk estimates based on ambient measurements may over- or underestimate risk, leading to ineffective or inefficient management strategies. In the present study we examine the extent of exposure misclassification and ...

Elevated concentrations of atmospheric carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have the potential to affect tree physiology and structure and hence forest water use, which has implications for climate feedbacks. We investigated how a 40% increase above ambient values in [CO2] and [O3], alone and in combination, affect tree water use of pure aspen and mixed aspen-birch forests in th...

Although the effect of litter mixture on decomposition has been well documented, few studies have examined the relationships between richness and relative abundance of leaf species in litter mixture and changes in universal fungal communities during the decomposition process in temperate forests. In this study, we used the litterbag method and included three leaf litter species, i.e., aspen (Po...

T he first Aspen Lung Conference entitled “Symposium on Emphysema and the Chronic Bronchitis Syndrome,” was held in 1958. It’s purpose was to develop an understanding of what these terms meant and to begin to unravel the causes and factors associated with the prognosis. The original Aspen Emphysema Conferences were funded by contracts from a branch of the United States Public Health Service. Th...

S June 4th – 6th, 2006 Hotel Jerome Aspen, Colorado Progress: From Bench to Bedside Platform & Poster Presentations

The aim of this paper is the steady state and dynamic simulations of the ammonia unit of Shiraz petrochemical complex and system behavior study versus the feed flow rate change for producing a good quality product. The ammonia unit consists of the reformer units, shift converter units, carbon dioxide absorption unit, methanation unit, and ammonia synthesis unit. For this purpose, in the first s...

“Lipid Accumulation in Hepatic and Extrahepatic Tissues,’’ a research seminar sponsored by the Aspen Bile Acid/Cholesterol Conference, Inc., was held at the Given Institute of the University of Colorado School of Medicine in Aspen, Colorado on August 17-20, 1991. This symposium was planned to bring together investigators who approach the general problem of tissue accumulation of lipids from dif...

A number of successful applications of automated planning and scheduling applications to spacecraft operations have recently been reported in the literature. However, these applications have been one-of-a-kind applications that required a substantial amount of development effort. In this paper, we describe ASPEN (Automated Planning/Scheduling Environment), a modular, reconfigurable application ...