Several types of channel morphology measurement parameters used to
characterize fish habitat of small streams are refined, developed and evaluated in terms
of their accuracy, precision, and sensitivity to disturbance. Data for 74 stream reaches
in Oregon and Alaska are used in analysis. Over half the reaches are from a...
Previous research has shown that using fine lightweight aggregate (FLWA) can be a promising strategy to mitigate alkali-silica reaction (ASR) in mortar and concrete. While several possible theories were proposed by researchers, discrepancies in testing methods, materials, and supporting evidence still exist. Therefore, this study was initiated. There are two...
According to most health organizations, "obesity" (defined as body mass index [BMI] greater than 30) is a world health problem of "epidemic" proportions. The underlying assumption is that weight is a proxy for health. However, obesity prevention and reduction interventions are designed to regulate body weight, rather than improve health....
PURPOSE: We tested the hypothesis that the unsupervised, isokinetic 3- minute all-out cycling test (3MT) would be a valid and reliable way to determine end power (EP) and work done above end power (WEP). Additionally, we hypothesized that EP would successfully demarcate between heavy and severe-intensity exercise and thus represent...
Ecological resources available to freshwater fish shift spatially, temporally and across life stages. To better understand how spatial-temporal availability of resources influence fish, I examined the phenologies of hatching and emergence of Coho Salmon (Oncorhynchus kisutch) in streams with contrasting and strongly defined seasonal thermal variability. The study streams included...
In the field of civil infrastructure, bridge desks are typically constructed using high performance concrete (HPC). Concrete bridge decks demand qualities such as low permeability, high abrasion resistance, superior durability, and long design life. Over decades of field and laboratory experience, many HPC bridge decks have been found to be...
Studies of the effects of forest harvest on streams and fish have a long history in the Pacific Northwest. Results of this work have prompted development of new forest harvest practices that are more protective of these resources, but the effectiveness of these new practices has not been fully evaluated....
:
_____________________________________________________________________
Jason B. Dunham
Studies of the effects of forest harvest on streams and fish have a long
Riparian forests provide a myriad of ecosystem functions for adjacent streams and rivers, and due to these linkages, changes in riparian forest conditions can have direct implications for stream ecosystems. Resource managers in the coast redwood forests (Sequoia sempervirens) of northern California (USA) are actively thinning second-growth stands to accelerate...
The most common test methods to evaluate alkali-silica reaction (ASR), the concrete prism test (CPT) and the accelerated mortar bar tests (AMBT), have limitations and are not entirely reliable in terms of predicting the performance of concrete with prevention measures under field conditions. In this study, the miniature concrete prism...
When observers monitor for infrequent signals for extended durations, they generally experience a decline in detections over time. This decline is termed the vigilance decrement. Current theories of vigilance attribute the decrement to three potential mechanisms: conservative shifts in response bias, losses of sensitivity, and an increased rate of attentional...