Fault zones are potential paths for release of radioactive nuclides from radioactive-waste
repositories in granitic rock. This research considers detailed maps of en echelon fault zones
at two sites in southern Sweden, as a basis for analyses of how their internal geometry can
influence groundwater flow and transport of radioactive...
Full Text:
AN ABSTRACT OF THE DISSERTATION OF
Joel Edward Geier for the
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants that occur in complex mixtures. These environmental mixtures can consist of both parent PAHs and their derivatives. Several parent PAHs are known or suspected mutagens and/or carcinogens, and a handful of PAH derivatives are known to be more potent mutagens and/or carcinogens...
The northern California Current System is impacted by two primary freshwater
sources: the Strait of Juan de Fuca and the Columbia River. The Columbia is frequently
bidirectional in summer, with branches both north and south of the river mouth
simultaneously. We describe the interaction of these two warm Columbia plumes...
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Chemical Society and can be found at: https://doi.org/10.1021/acs.est.5b00499
Full Text:
. Environ. Sci. Technol. 2013, 47 (15), 8434–8442. 519
(44) Truong, L.; Reif, D. M.; Mary, L. S.; Geier
Concentrations of domoic acid (DA) above the regulatory limit in Washington coast razor clams are usually higher on northern beaches from summer to fall. Recent field studies have confirmed that the primary source of toxic Pseudo-nitzschia (PN) cells in those seasons is a semi-retentive topographically trapped seasonal eddy located offshore...
With the advent of next generation reactor systems and new fuel designs, the U.S. Department of Energy (DOE) has identified the need for the resumption of transient testing of nuclear fuels. The DOE has decided that the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) is best suited...
Coastal hypoxia, or low oxygen episodes pose a threat to marine resources in the Pacific Northwest. Previous research into nearshore oxygen dynamics have linked coastal upwelling to this seasonally occurring phenomenon, however the manifestation of hypoxic waters over coastal fishing grounds was not well understood. Through a partnership with Dungeness...
Two bloom-detection products were developed for the Oregon coast that describe the relative percent change observed between successive pairs of 8-day chlorophyll-a (CHL) and fluorescence line-height (FLH) products obtained from the MODerate Resolution Imaging Spectroradiometer aboard the Aqua spacecraft (MODIS-Aqua). The CHL[subscript dev] and FLH[subscript dev] products, respectively, were optimized...
The link between aboveground net primary productivity (ANPP) and resource gradients generated by complex terrain (solar radiation, nutrients, and moisture) has been established in the literature. Belowground ecosystem stocks and functions, such as soil organic carbon (SOC), dissolved organic carbon (DOC), and belowground productivity have also been related to the...
Phytoplankton are a sentinel class of organisms in the marine environment. Through their photosynthetic activity in sunlit waters worldwide, phytoplankton shape the health and productivity of marine ecosystems and impact the global climate. In this work a range of ocean sensing technologies (via ships, surf zone sampling, moorings, gliders, and...
Toxicological studies were carried out to evaluate the
susceptibility of codling moth, Cydia pomonella L. to
different insecticides. Bioassay procedures for adults and
larvae were standardized in terms of posttreatment holding
and temperature, age and sex of insects, insecticide
formulations and selection of a reference strain.
This study detected a...
Anthropogenic carbon dioxide emissions are causing ocean acidification (OA) and ocean warming, which have negative effects on the larvae of many marine invertebrates. Oregon pink shrimp (Pandalus jordani) currently encounter upwelling events that can result in pH values as low as 7.6, and, more recently, marine heat waves that raise...
The COVID-19 pandemic has shed a light on the need for people to trust in medical science. With the need for 70% of Americans to be vaccinated to achieve herd immunity but 30% have reported vaccine hesitancy, now more than ever do we need to redouble our efforts to ensure...
For the first time in several years, the El Niño-Southern
Oscillation did not dominate regional climate conditions
around the globe. A weak La Niña dissipated to ENSOneutral
conditions by spring, and while El Niño appeared
to be emerging during summer, this phase never fully
developed as sea surface temperatures in...
Disturbance, whether natural or of human origin, modifies to varying degrees
many ecosystem attributes. Fire is a natural process in the montane forests of southern
Oregon but for much of the 20th century fire was viewed as an apocalypse and thus
fervently suppressed. Effective natural resource management requires an
understanding...
Zinc oxide nanoparticles (ZnO NPs) have demonstrated the ability to improve lubrication and thermal conductivity, and stand as promising metalworking lubricant and coolant additives due to their low cost compared to other NPs. While nanomaterials are a focus of research due to their potential to enable advanced technologies, little is...
The determination of the optimal location of transceivers is a critical design factor when deploying a wireless local area network (WLAN). The performance of the WLAN will improve in a variety of aspects when the transceivers' locations are adequately determined, including the overall cell coverage to the battery life of...
Cultivars of several cereal crops have been developed with acetohydroxyacid synthase (AHAS)
insensitivity to imidazolinone herbicides and are now an important tool for weed management.
Options for screening for imidazolinone resistant lines include direct herbicide application,
biochemical assays for AHAS activity and DNA-based methods. Herbicide and biochemical
assays for AHAS...
Zebrafish are capable of fully regenerating organs and tissue such as their caudal fin, which is similar to a human regrowing an arm or a leg. In contrast, most mammals including humans have a greatly reduced capacity for wound healing. The ability of zebrafish to undergo this regenerative process, called...
Pacific harbor seals (Phoca vitulina richardii) are one of Oregon’s most common coastal predators, numbering between 10,000 and 12,000 individuals (Brown et al. 2005b). They consume more than 149 species or types of marine prey within the Pacific Northwest, which include a large variety of commercially important fisheries species. Despite...