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Final Report: Center for Ecological Health Research

EPA Grant Number: R825433
Center: EERC - Center for Ecological Health Research (Cal Davis)
Center Director: Rolston, Dennis E.
Title: Center for Ecological Health Research
Investigators: Rolston, Dennis E.
Institution: University of California - Davis
EPA Project Officer: Levinson, Barbara
Project Period: October 1, 1996 through September 30, 2000
Project Amount: $6,110,000
RFA: Exploratory Environmental Research Centers (1992)
Research Category: Center for Ecological Health Research , Targeted Research

Description:

Objective:

The overall objective of the Center for Ecological Health Research (CEHR or Center) is to investigate basic science questions in an applied context. The specific objectives of the CEHR are to: (1) maintain and intensify interdisciplinary research on complex ecosystem processes; (2) develop and verify new data management, risk analysis, and modeling techniques; (3) develop and apply new sensitive and reliable biomarkers based on a mechanistic understanding of toxic processes; and (4) use new methodologies to effectively characterize and develop cost-effective strategies to manage ecological risks and communicate them to users and managers. The CEHR is located at the University of California–Davis (UC–Davis). UC–Davis is in the center of a region experiencing one of the most rapid population growth rates in the United States, thus producing a high rate of urban encroachment in areas that include highly sensitive ecosystems, including the Nation's most diverse and productive agricultural lands. Within a few hundred miles of UC–Davis are several well-known ecosystems that Center researchers are using as long-term case studies.

Summary/Accomplishments (Outputs/Outcomes):

What Did We Do?

The central goal of the Center was to understand how multiple stresses interact to affect biological and ecological processes in aquatic and terrestrial systems. Natural stresses—such as drought, salinity, and climate change—and anthropogenic stresses—such as toxic compounds, nutrients, species introductions, and habitat destruction—are cumulative impacts on ecosystems. An important product of the Center's activities was a toolkit of inexpensive methods to reduce the theoretical complexity of a multiply stressed ecosystem to a manageable level. The Center provided a forum and structure that identified significant issues, design assessment strategies, and integrated research efforts relevant to assessing risks on selected ecosystems.

Why Did We Do It?

Environmental policymakers must cope with the fact that ecosystems are exceedingly complex. The complexity, uniqueness, and diversity of ecological systems are critical impediments to the practical analysis of problems resulting from multiple stresses. The Center provides a mechanism for university researchers and outside scientists, engineers, policymakers, and managers to work together to focus research and remediation on the most important elements impacting a particular ecosystem.

How Did We Do It?

The Center was a group of 36 faculty and approximately 50 graduate students from 4 colleges and schools at UC–Davis. The Center brought together scientists from many disciplines to study transport and fate, ecology, and toxicology in specific watersheds. The combining of disciplines to focus on a specific geographic area provided an infrastructure to promote long-term multiprocess environmental studies that more closely reflect the ways ecosystems function. Combining disciplines leverages the tools, methods, and perspectives of classic academic disciplines to provide new insights into data collection, synthesis, and analysis. Studies of the molecules, cells, and behaviors of individual organisms were coupled with models of population dynamics in communities and models of transport and fate in air, water, and soil to explore the relationship between physical and biological processes. Together, Center researchers worked to answer six general scientific questions:

• Which parameters provide the best early assessment of ecological risk in specific ecosystems, and what features of specific ecosystems likely are to be most informative?

• What quantity, precision, and accuracy are required of environmental, ecological, and biochemical data to insure their usefulness in specific monitoring programs?

• How can chemically derived risks be studied separately and in combination with other environmental risk factors such as drought, urbanization, and other anthropogenic activities?

• What are the expected transit times, exposure levels, and fate of toxic materials in soil, air, and water of selected ecosystems, and how can such information be used to predict long-term effects?

• How do multiple stresses interact at the watershed scale?

• How can we best provide information to public agencies and individuals to better manage the environment?

The Center used three important and representative aquatic and terrestrial environments in northern California to evaluate new approaches for addressing multiple stresses: the Sacramento River Watershed, the Clear Lake Watershed, and the Sierra Nevada Watershed. There also are three research projects whose primary function was to conduct general basic research on developing tools and techniques that researchers can apply to specific watersheds: Analytical and Biomarkers, Transport and Fate, and Data Integration and Decision Support.

Highlights

Sacramento River Watershed. The convergence of toxicological assessment methodologies, paleo-climatic assessments, and coupled atmospheric hydrologic models offer great promise in evaluating the health of the watersheds we have selected for intensive study. One such model for the Sacramento River, Delta, and the San Francisco Bay continues to be a crucial aid to environmental managers of this watershed. This methodology is being extended to other river systems in the West.

• The Center's Decision Support research project has evolved into the Information Center for the Environment (ICE), a facility that has attracted additional cooperative informatics projects with some 30 state and federal agencies, including more than a dozen with U.S. Environmental Protection Agency (EPA) Region 9. By creating a geographic information system (GIS), a database, and a Web framework for integrating disparate data sources and making them publicly available, ICE has provided the information gathering capabilities necessary to support large multiagency environmental programs such as the CALFED Bay-Delta Program and the Interagency Ecological Program.

• With partner funding from the California Resources Agency, through the California Rivers Assessment, the CEHR developed data infrastructure standards and tools to correct and update the U.S. EPA River Reach database. The data and many of the tools developed through this effort have been adopted by the nationwide National Hydrological Database (U.S. Geological Survey [USGS] and U.S. EPA), the current standard for hydrography in California and the Nation.

• Biodiversity information architectures first developed at the CEHR have been adopted internationally, and have resulted in information scientists from leading programs at the National Biological Information Infrastructure (NBII), the Missouri Botanical Garden, and the Smithsonian having a presence on the UC–Davis campus.

• CEHR researchers have developed environmental informatics tools that represent advances in information science and ecology. Tools that have become widely used in the northern California region include:

• Methods to assess forest height, cover, and composition using hyperspectral imagery, with the results used to detect landscape changes and their implications for sediment supply into rivers and streams.

• Assessment of the relative suitability of riverbank and floodplain areas for riparian restoration.

• Assessment of changes in populations of neotropical migratory birds as indicators of both habitat quality in California and biological impacts of global change at a hemispheric scale.

• Models of future urbanization and its potential impacts on rare habitats and species.

o Models to predict the geographic distributions of species of conservation concern (both rare and invasive species).

• CEHR researches have calibrated and validated multidimensional numerical hydrodynamic (RMA-2) and water quality (RMA-11) models of the Sacramento River-San Francisco Bay-Delta system to provide the hydrodynamic and water quality foundations (baselines) necessary to assess the impacts of water development in the Sacramento Valley and Delta. These operational hydrodynamic and water quality models of the Sacramento River, Delta, and San Francisco Bay system are the only ones that allow users to model the transport of both organisms and waterborne constituents (contaminants, salinity, temperature) from point sources and spawning sites well above the delta into the marine environment outside the Golden Gate. By combining these models with a particle-tracking model (SAMTRK), which was developed for individual-based simulation of endangered juvenile winter-run chinook salmon, investigators were able to simulate the impacts of alternative water management schemes contemplated under CALFED for the river-delta system on migrating juvenile salmon. Models of this scope are essential to the analyses needed to implement the Bay-Delta agreement among the U.S. EPA, the Bureau of Reclamation, the U.S. Fish and Wildlife Service, and the major California water and wildlife agencies. These models have been adapted successfully to mercury transport in Clear Lake and pesticide transport in the Sacramento River, and potentially are applicable to a wide variety of other aquatic ecological risk analyses in California and elsewhere.

• We have shown that there are important similarities between the mechanisms that mediate the physiologic actions of sex steroid hormones and those that mediate the toxic actions of chlorinated hydrocarbons in mammals. Specifically, our data demonstrate that halogenated aromatic hydrocarbons act through some of the same cytosolic signal transduction pathways and/or gene activators as sex steroid hormones and growth factors. The xenobiotics, however, may not require direct interaction with the hormone/growth factor receptors, but may interfere with downstream signals. This interpretation provides the first explanation of the cellular basis for species- and gender-specific differences in the severity of adverse effects resulting from exposures to environmental toxicants in vertebrate species.

• We found that peak concentrations of diazinon in the surface runoff and canal water correspond to the heavy rainfall events and intensive applications of diazinon during the dormant season. The timing of the rainfall and pesticide application is critical to the environmental fate and transport of diazinon. This information may influence decisions about the timing of pesticide applications to minimize the adverse effects of runoff.

• Reproductive failure in wildlife species is one of the more sensitive indicators of adverse effects from environmental stressors. We have developed noninvasive methods and validated assays that can assess reproductive function of free ranging wildlife species. Fecal testosterone assays have been applied to mice and correlated to exposure and reproductive success. Similar assays are being developed and applied to avian species.

• Center investigators studied wild bird populations as sentinels of ecological health in terrestrial and aquatic ecosystems. By monitoring wild bird populations (red-tailed hawks, American kestrels, white-tailed kites, and cliff swallows) in the agricultural lands of Yolo County, Center investigators have seen that some species thrive and others seriously are impacted by agricultural practices. Red-tailed hawks wintering in the Sacramento and San Joaquin Valleys were at risk from dermal exposure to dormant sprays containing organophosphates used in almond orchards. Parathion, which is now banned, was identified as the principle hazard. For insectivorous cliff swallows, there is a significant negative relationship between pesticide use and reduced reproductive success. Although there are no differences between colonies in egg laying, there is a significant depression in raising chicks in areas with high pesticide use. Whether this is because of a reduced population of insects or pesticide-contaminated insects fed to nestlings is still under investigation. In contrast to the stresses from pesticide exposure, American kestrels and white-tailed kites unexpectedly are thriving in spite of what appeared to be a significant reduction in food supply. Although small rodents, the main food source of these two species, are almost completely eliminated from most crop areas, there is sufficient prey on roadsides, field boundaries, and some crops for kite and kestrel populations to remain high.

• Double-crested cormorants, which breed in several large colonies in the San Francisco Bay and Delta, are being used to investigate the effects of bioaccumulating organochlorines. Other colonies along the California and Oregon coast act as reference sites. The effects on cormorant embryos in the more contaminated colonies were significant. The data subsequently have been used to compare San Francisco Bay with the Great Lakes and other contaminated areas of the United States in setting priorities for monitoring and cleanup. The technique developed for candling eggs in the field now is used by the U.S. Fish and Wildlife Service for field monitoring of waterbird colonies.

• Pesticide and endocrine disruption studies with songbirds in the laboratory and field have demonstrated significant adverse effects. Using zebra finches as a model species, we have shown that oral administration of estrogens and estrogenic pesticides to young chicks (days 5-11) results in masculinization of females and feminization of males. Females at sexual maturity (120 days) have altered brain nuclei, allowing females to learn, remember, and sing courtship songs. Dosed males and females both exhibit reduced interest in breeding, and mating dosed birds together resulted in complete breeding failure. Mating dosed birds with controls resulted in reduced breeding success compared to controls.

• Using microsomal enzyme induction biomarkers, Center investigators have provided the clearest evidence to date that fish populations in the delta are affected by a complex interaction between low-level toxic effects, predation, and residence times determined by flows and diversions. These results suggest changes in the monitoring information needed to meet U.S. EPA objectives under the Bay-Delta agreement, and provide some technologies applicable to detecting toxic effects.

• The CEHR is using biochemical indicators to characterize the effects of multiple stresses. In the resident Asian clam of the San Francisco Estuary, we have defined indicators of hypoxia and salinity and uncovered a metallothionein-like protein that correlated with the cadmium gradient in the sediment and cadmium body burden of the clam. These indicators should be useful for detecting natural fluctuations of the physiochemical conditions of the estuary. Selenium is a controversial contaminant in the San Francisco Estuary because of oil refinery discharges and the inflow of agricultural wastewater from the San Joaquin River. By combining gel electrophoresis and ultrasensitive laser ablation coupled with inductively coupled plasma-mass spectrometry, we have been able to link proteinaceous selenomethionine to adverse effects in aquatic predators. This may be a reliable indicator of selenium food chain transfer and toxic effect. With this indicator, we can develop ways to verify or improve current selenium water quality criteria.

• Analysis of cellular stress protein levels, in combination with other health indicators, can aid in understanding the physiological condition of the organism, as well as identify cellular stress caused by xenobiotic compounds (cadmium, chromium [VI]) in laboratory studies. So far, however, complex response patterns preclude their application as stress indicators in field studies in which multiple stressors are present. Exposure of organisms to multiple xenobiotic and physical stressors can lead to upregulation as well as downregulation of heat-shock proteins. The response is dependent on the nature of the stressor and the physiological condition of the organism. This information should be taken into account by other researchers investigating stress responses in field organisms; this "masking" of stress response in the field potentially could lead to false negatives.

• Work sponsored by the Center established that the geographic location of the .2 percent salinity contour (X2) in the Sacramento Delta was an effective marker for monitoring the ecological health of the estuary. X2 generally marks the principal entrapment zone for particles and plankton, and varies in location between the Carquinez Strait and far upstream into the delta, depending on flow. Acceptance of this standard (despite vigorous attempts by some industry groups to discredit it) was pivotal in the landmark 1994 interagency agreement for managing water policy in the Central Valley and the San Francisco Estuary, and it continues to be used in policy decisions.

• The analysis of historical data for the San Francisco Bay-Delta has revealed a clear dependence of fish and shellfish population abundances on the rate of freshwater flow from rivers into the estuary. These results are being used by federal, state, and end-user interests (the "CALFED" agreement) for allocations of freshwater to protect both social and environmental concerns.

• We developed a sampling method for optimizing water quality transects in estuaries. The method enables one to determine the number of stations needed to achieve a desired precision for some global statistic. It particularly is appropriate when historical data are too sparse spatially to compute a variogram. As a practical application, we showed that the number of traditional transect stations in the San Francisco Bay could be halved without losing essential information.

• We developed breeding pairs of "see-through" medaka that provide a method of capturing and storing images of observed changes in internal fish organs during embryogenesis and experimental exposures. Using a culture of transgenic, pigment-free, "see-through" medaka and fluorescence microscopy, we were able to visualize specific fluorescent compounds in living medaka. This important development extends our ability to describe phenotypes of exposed fish throughout their life, and will be useful to many investigators studying fish development. To date, other systems were transparent only during embryogenesis, and internal changes could not be visualized because of reflectance of light by pigment cells in dermis and peritoneum.

• Studies funded by the U.S. EPA/CEHR led to a fully funded study on dietary selenium and selenium biochemical forms in a U.S. Fish and Wildlife Service-listed "threatened" fish (splittail) in the bay/delta. This will allow us to establish a cause-and-effect relationship between reproductive impairment and biotoxicity markers in a wild organism for more definitive information about pollutant food chain effects.

• We showed that despite substantial organic matter input by rivers, agricultural drainage, and other sources, the food web in delta waterways is driven mostly by phytoplankton production. The research results provide the scientific basis for making phytoplankton production a focus in understanding anthropogenic and climatic impacts on the estuary. Along with realizing the fundamental importance of primary production, we found that multiple mechanisms underlie its long-term variability. Precipitation and sediment trapping by dams and invasive species, the clam Potamocorbula in particular, have caused major long-term changes in delta-wide primary production. We also showed that nutrient-rich turbid systems such as the delta lack certain compensating mechanisms that probably render them inherently more variable than more common nutrient-limited systems.

• Center investigators are continuing to improve analytical procedures for estimating population parameters and deriving consequent risks of extinction in several fisheries species (including chinook salmon and delta smelt) of immediate concern to U.S. EPA regulators. Results from these analyses have been adopted into interagency management strategies for several of these species. Developments also include a novel method for decomposing environmental time series into independent modes of variability, and for identifying each mode with a separate underlying mechanism. The method allows extraction of information from instrumental time series that previously were considered too short to distinguish multiple stressors. The results obtained by the method also can be cast in the form of a predictive statistical model.

• We demonstrated the importance of restored floodplains as fine sediment storage sites in alluvial rivers. This work documented how reconnections between historic floodplains and present-day channels can be used to reduce fine sediment loads through sand splay deposition. This work also evaluated the habitat restoration benefits of these approaches. Our findings may be beneficial to environmental managers and investigators working on similar projects.

Clear Lake Watershed. There is a steep gradient of inorganic mercury concentrations within Clear Lake sediments ranging from more than 400 ppm (near the Sulphur Bank Mercury Mine), some of the highest documented sediment concentrations in the world, to nearly nondetectable (at the opposite end of the lake). This gradient makes Clear Lake an extremely valuable ecotoxicology laboratory tool for studies on mercury, copper, and many other contaminants that require measurement/assessment of in situ processes.

• Our work at Clear Lake is the first reported site at which mercury affects population and community level parameters of biological organization. Until now, nearly all known effects of mercury have been reported at the individual level. We showed that mercury in Clear Lake negatively impacts invertebrate population abundance and diversity metrics. In addition, fish populations for several species were shown to be negatively correlated with proximity to the mine. With these new data, researchers can better assess mercury effects on higher level population and community-level processes.

• We developed a comprehensive approach to mercury ecotoxicology at Clear Lake using the lake and its watershed as a model for understanding the transport, transformation, effects, and fate of mercury in a semiarid environment. The production of methylmercury, the bioavailable form of mercury, in Clear Lake is the result of many watershed stressors. In addition to the acid mine drainage from the Sulphur Bank Mercury Mine that contributes high concentrations of sulphate, protons (acidity), and soluable mercury, we have identified other factors that promote methylation processes. The mine contributes the raw materials, but other factors such as eutrophication, food chain amplification, the delivery of organic compounds to methylation sites followed by the dispersion of the methylmercury by wind-driven lake currents, and erosion all play a major role in methylmercury production and contamination. We believe that by understanding how all these factors interact, we can better determine how best to keep methylation processes to a minimum, thereby reducing the effects of mercury pollution on the biota of the watershed.

• We found that the first 75 years of European settlement in the Clear Lake Basin (including the most productive years of the Sulphur Bank Mercury Mine) appeared to have barely detectable effects on mercury deposition. The large increase in mercury levels beginning in approximately 1927 corresponds to the use of heavy equipment to exploit the ore deposit at the Sulphur Bank Mercury Mine with open pit methods. This finding provides managers and policymakers with further evidence in favor of regulating mining practices.

• Our data show that mercury loading to Clear Lake has not diminished in the 11 years following the remediation of the Sulphur Bank Mercury Mine site. We compared surficial sediment mercury concentrations from 34 sites around Clear Lake in the fall of 1992 and 2003. It appears that mercury loading has not decreased during this period, despite the U.S. EPA Superfund Program’s attempt to reduce mercury loading by the remediation of soils and waste rock piles on the mine site in 1992. This finding will help federal and state regulatory agencies drive the remediation process so that ongoing mercury loading can be reduced significantly or eliminated.

• Studies using radiotracers, determinations of changes in methylmercury concentration and measurements of net rates of sulfate reduction, indicate that anaerobic microbial processes other than sulfate reduction appear to be responsible for 50 to 75 percent of the mercury methylation in Clear Lake sediments. This is in strong contrast to the literature dogma that sulfate reducers are dominant methylators in freshwater and estuarine sediments, and potentially may have widespread implications for mercury research and abatement in Clear Lake. We are in the process of identifying the other methylating bacteria in our system.

• We have shown that erosion, eutophication, wetland destruction, and changes in land use patterns interact at Clear Lake to produce noxious cyanobacterial scums. Lake County successfully has obtained several remediation grants based on our recommendations on algal bloom control, a multimillion dollar problem for the recreational industry there.

• Because mercury is just one of many contaminants (including copper) within Clear Lake, we also embarked on an investigation targetted to evaluate the combined effects of the multiple stresses of mercury and copper on zooplankton, both the standard U.S. EPA bench test species (Ceriodaphnia) and the indigenous species in Clear Lake (Daphnia). Our goal was to determine whether the combined stressors were additive, inhibitory, or synergistic. These data suggest that the two multiple stressors interact additively, thus allowing a more accurate assessment of the multiple impacts of these stressors on the Clear Lake ecosystem.

• Inexpensive, very accurate, and sensitive assays of heavy elements by techniques mostly used previously for analyses of air samples (x-ray fluorescence and particle induced x-ray emission) are being applied to bird feathers and other tissues (plant and animal) to study mercury and other elements in Clear Lake biota. This is a nondestructive method for analyzing bird feathers for mercury, other contaminants, and other elements for use in: identifying contaminated bird populations, looking at differences in contamination levels in different trophic levels within a system, and for "fingerprinting" different geographical populations of birds.

• We developed a three-dimensional, public domain hydrodynamic model. We developed, calibrated, and validated the model SI3D-L using data from two extremely complex lakes (Clear Lake and Lake Tahoe). Unlike many commercial models, which receive little peer review, this model now has been the focus of several papers in leading journals. The model now can be used with great confidence by other investigators to describe motions in complex lake systems, study the fate of particulate material, and evaluate a range of restoration scenarios.

• We have developed a broadly applicable invertebrate bioassay for mercury that is useful as both a research and environmental management tool. A regional survey of mercury contamination in aquatic insects offers a rapid, inexpensive, and accurate method of assessing mercury bioaccumulation in the food chain. Measurements of inorganic mercury are not necessarily indicative of contamination of food chains by microbially produced methylmercury. Direct measurements of aqueous methylmercury are expensive and only assess this highly ephemeral component at single points in time. Fish are a good index of contamination, but are expensive to capture in numbers and generally cannot provide spatially or temporally specific information. Insects, in comparison, are relatively easy to capture and provide highly site-specific measures of mercury bioaccumulation over periods of weeks to months. Insects are represented by several trophic levels and can predict concentrations in fish quite well. Because of the ubiquity and consistency of these insects in most streams, this invertebrate bioassay is useful for surveying mercury contamination on regional scales. The analysis of total mercury on these biotic tissues is relatively inexpensive and can be performed in-house. Because the ratio of methylmercury to total mercury is moderately consistent for each trophic level or species, the ratio for each region needs verification on only a few samples, thus saving substantial analytical costs. This technique has been used successfully in streams throughout the Sierra Nevada as well as the California Coast Range.

• Upon the realization that a county lake weed eradication program was decimating nesting grebe colonies by driving power boats over the nests, the Center's researchers worked directly with local agencies to insure the conservation of these nesting areas.

• Methylmercury concentrations in sediment covers have a complex relationship to inorganic mercury. The methylation process may have been much more efficient in some strata than in others. Reinvestigations, using up-to-date methods of analysis, currently are in progress and should support or refute previous findings of subsurface methylmercury maxima. If confirmed, these maxima may represent periodic, very high organic loading of sediments (perhaps via especially strong algal bloom years) that join with significant concentrations of inorganic mercury in these same sediments to continue to drive mercury methylation over extended periods in certain strata.

• Our study is the first to determine the long-term (weeks) dietary methylmercury assimilation rate of a fish. Juvenile Sacramento blackfish assimilated between 40 and 60 percent of the dietary methylmercury fed by 35 days and between 33 and 43 percent by 70 days. These results contribute to the construction of better ecosystem-based mercury-movement models, and to more informed natural resources management at Clear Lake and other aquatic systems.

• Several additional long cores ranging from 270 cm were collected from all arms of Clear Lake to reanalyze the depositional history of total mercury in these sediments. Based on preliminary data returns, it seems that the conclusion is supported strongly that mercury storage in these sediments shows obvious step increases during periods corresponding to the onset of mining and acceleration of the pace of mining using power machinery. These refined estimates, plus lead dating of depositional rates, should allow more precise calculations of annual mercury loading to Clear Lake sediments from the Sulphur Bank Mercury Mine.

• We have developed a broadly applicable tool to assay the methylmercury production potential of aquatic sediments. A series of controlled microcosm experiments evaluated over days to weeks has proved extremely useful in comparing methylmercury production in sediments (under varying environmental treatments) from widely varying locations within Clear Lake. This method has the ability to assess both the potential and the maximum innate capacity to produce methylmercury given a set of known environmental conditions. This method now is being used in San Francisco Bay-Delta studies as well as Upper Cache Creek Watershed studies on the soils from abandoned mines.

• We documented a significant decline in mercury residues in osprey and grebe feathers, a change to normal in several biomarkers of mercury effect, and significant improvements in demographic performance of both species throughout the study period (1992-2002). These changes were partially because of a long-term trend of declining mercury residues and a single mine site remediation event in the early 1990s. All indications from our monitoring program were that several endpoints of negative effect from mercury contamination were lessened by active agency management activities. This finding reinforces management agencies’ essential role in ensuring ecosystem health.

Sierra Nevada Watershed. Long-term studies at Lake Tahoe continue to assist in ecosystem management in the Sierra Nevada bioregion as well as mountainous areas in the Western United States. Atmospheric nitrogen deposition contributes more than 50 percent of the nitrogen in Lake Tahoe and is a ubiquitous global problem. Bioassay experiments with natural algal populations clearly show the importance of direct fertilization from the atmosphere. Lake Tahoe has changed from a classically nitrogen-limited system to an increasingly phosphorous-sensitive system, with soil-derived phosphate entering the lake as the key determinant of future eutrophication. The Tahoe Research Group and CEHR collaborators worked in cooperation with resource and planning agencies to implement effective methods of watershed management.

• Reconstructing stresses through paleolimnology, the study of lake sediment, provides a means to investigate Lake Tahoe's response to historic stresses. The analysis of deep lake sediment cores at Lake Tahoe utilizing lead (210Pb) as a marker has allowed reconstruction of the impacts and indicates lake response to human and natural stimuli. Sediment lead and mercury profiles indicate that the Tahoe Basin experienced a substantial increase in the flux of some atmospheric pollutants. The primary source of atmospheric lead has been from gasoline additives. Nitrogen pollution also is associated with gasoline consumption, and now we have indirect evidence for this as a substantial source of additional nutrient input. The diatom sedimentary record indicates that Lake Tahoe has experienced a fundamental shift in species associated with enhanced nutrient inputs to the lake following urbanization. Charcoal in modern sediments at Tahoe are substantially lower than natural background concentrations, reflecting modern fire suppression activities and their impacts on nutrient mobilization within the watershed.

• A recent analysis of long-term water clarity changes revealed the role played by mineral suspensoids, in addition to phytoplankton. The results imply that watershed management must prevent small clay particles from reaching the lake, where they can accumulate and remain suspended for years. Previously, the emphasis has been on limiting bulk soil erosion and nutrient loading.

• An initial nutrient budget for Lake Tahoe has been completed. Of the estimated 418 metric tons of nitrogen loaded during a representative year, more than one-half (59 percent) comes from atmospheric deposition. Direct runoff (overland flow directly to lake), groundwater, and stream loading contribute on the order of 5 percent, 15 percent, and 20 percent, respectively. For total phosphorous, direct runoff, stream loading, and atmospheric deposition account for approximately 25-30 percent, 30 percent, and 25-30 percent, respectively. Annual loading of total phosphorous to Lake Tahoe is estimated to be approximately 4 metric tons. This finding suggests that the three important sources of phosphorous should be evaluated in more detail to determine the specific sources of phosphorous within each category, and to evaluate the cost-benefits for phosphorous reduction within each. The loading budget for dissolved phosphorous was estimated to be approximately 14 metric tons or about one-third of the total phosphorous load.

• We found that nutrient sedimentation losses to the bottom of Lake Tahoe are 401.7 metric tons for total nitrogen and 52.8 metric tons for total phosphorous. These agree remarkably well with the independent loading estimates given above. This close agreement gives us increased confidence that the loading rates are representative.

• We found—for the first time—that organic nitrogen in fog water and aerosol particles photochemically was converted into more bioavailable inorganic nitrogen species, and is a key component in smog (ozone) formation. These results are significant for a number of reasons. First, they indicate that atmospheric reactions increase organic nitrogen bioavailability and, therefore, increase its ecological impact after deposition. Similar reactions probably also occur after deposition (e.g., in Lake Tahoe). Therefore, investigators must consider inputs of organic nitrogen on nutrient loading to aquatic and terrestrial ecosystems in the Sierra. Second, the conversion of atmospheric organic nitrogen into inorganic forms might have important impacts on atmospheric chemistry (e.g., via NOx release) and the properties of atmospheric particles and aqueous drops (e.g., their climatic and health effects). These results will improve models of nitrogen transport and ecological impacts.

• We developed a Watershed Environmental Hydrology (WEHY) model for the estimation of sediment and phosphorous loading to Lake Tahoe. This comprehensive watershed model simulates the hydrology and fate of pollutants such as sediment and nutrient to accurately estimate the influx of sediment and phosphorous into Lake Tahoe for further analysis of lake water clarity. With this model, alternative management scenarios can be evaluated to find the best management practice that can minimize the disturbance within the watersheds to improve the water quality of Lake Tahoe. The model is thought to have significant potential to serve as a useful decisionmaking tool for taking managerial actions. It allows watershed managers to assess the cost/benefits of various policy scenarios.

• Two applications of WEHY to the Ward Creek Watershed in the Lake Tahoe Basin have shown that WEHY can reproduce the pattern of historical flow, sediment, and phosphorous loads with reasonable accuracy. Furthermore, the model performed consistently well for an independent data set. Overall comparisons were encouraging, and showed promise for the potential use of the WEHY model in studying the effects of different land management practices on ecological systems at both gauged and ungauged watersheds.

• Nitric oxide is a precursor to the production of ozone near the ground. By creating a mechanistic model for production of nitric oxide and nitrous oxide from nitrification processes in soils, CEHR researchers are developing the capability to estimate the amount of nitric oxide (and thus ozone) that may result from agriculture as compared to fossil fuel burning. Field data and computer simulations indicate that as soil pH decreases, because of increased ammonium fertilizer applications, emissions of nitric oxide will increase from soils.

• During the summer of 2000, two aircrafts were operated with meteorological sensors, ozone, NO/NOy, and particle analyzers as well as the sophisticated wind finding system as part of the Central California Ozone Study (2000). The flight paths covered central California from the coastal regions to the Sierra foothills. These data will be useful to define the three-dimensional distribution of pollutants and the wind field upwind of the Sierra.

• We showed that polychlorinated biphenyl (PCB), toxaphene, and organochlorine pesticides can reach even the most remote areas of Sierra Nevada, as judged by their presence in rainbow trout. Small but significant amounts of PCB and organochlorine pesticide residues are found in rainbow trout samples from even very remote, high-altitude lakes and streams of the Sierra Nevada. This finding suggests that PCB contamination can be unexpectedly widespread, perhaps prompting stronger efforts to monitor PCB and other organochlorine pesticides.

• We identified two new biochemical markers (H:G lignin ratio and stilbene) of ozone injury in individual ponderosa pines. These markers will provide investigators with an inexpensive method of establishing long-term forest injury records for a large number of sites; an extremely difficult task until now. The biochemical nature of these markers also would allow us to link them to the mechanism(s) of ozone injury so that we could determine, under real field conditions, the photochemical oxidant species most injurious to trees. This information then could be used by environmental management and regulation agencies to mitigate forest ozone damage.

• Our evidence indicates that precontact old-growth forests in the basin were significantly different from modern old-growth forests in several ways. Modern forests have approximately two to three times as many trees per unit area as in the past. It is likely that the increased density of trees causes more intensive competition for soil moisture, and during drought years the increased competition leads to twice as much mortality as would occur with precontact tree densities. This information could influence fire suppression management strategies.

• Our data show that modern forests have three to nine times as many fir trees as pine trees, in contrast to a past ratio of 1:1. Unknown ecosystem consequences may result from a shift in the dominant species of a community, but surely some herbivorous birds, insects, and mammals will respond to such a gross change in their cafeteria. Those who manage the monitoring of rare or endangered animal species should be concerned with this change.

• We suggest that the major factors responsible for changes in tree density and species composition over the past 150 years are clearcutting (which sets back succession), fire suppression management, the disappearance of Native Americans from the landscape, and climate change. These factors—especially the first two, because only those have the potential for reversal—should be kept in mind by management agencies.

• Our results suggest that white pine blister rust incidence in mixed-conifer forests largely is dependent on topographic features that favor environmental conditions suitable for rust infection. In the Lake Tahoe Basin, three species are affected by this disease: sugar pine (Pinus lambertiana), western white pine (Pinus monticola), and whitebark pine (Pinus albicaulis). Western white pine grows in the transition zone between upper montane and the subalpine zone, whereas whitebark pine exists only in the subalpine zones. These two species are important components of these subalpine habitats, and are valued for their roles in watershed protection and wildlife food at these higher elevations. Loss of these species from the subalpine landscape would have major ecological consequences. Thus, forest management agencies will find our results useful in protecting these valuable species.

• Data intensive studies of subsurface and surface hydrology at Pope Marsh, South Tahoe Basin, demonstrate that vegetation declines in the marsh have been a direct result of anthropogenic effects on inflows of groundwater or surface water. Groundwater inflow to the marsh declined because of groundwater pumpage, and surface water inflow declined because of rerouting of distributaries of the Upper Truckee River during construction of the Tahoe Keys in the 1960s.

• We assessed the potential of Lake Tahoe Basin wetlands for phosphorous removal. An important question for reducing the phosphorous input into Lake Tahoe is: How much phosphorous from stream loading and direct runoff potentially may be reduced by wetlands? Based on our data obtained during the course of this project, we came up with the following estimates: assuming the wetland area of about 75 ha and annual accumulation rate of 0.22 g m-1, retains a total of 165 g phosphorous per year. This corresponds to slightly more than 0.5 percent of annual phosphorous input into the lake. Thus, wetlands do not retain most of the phosphorous entering the lake, and therefore are not a solution to the phosphorous problem in the Tahoe Basin.

• Aircraft measurements suggest that regional, "out of basin" areas such as the Central Valley can be significant sources of nitrogen pollution to Lake Tahoe during the summer when the wind predominantly blows from the Central Valley to the Sierras. In contrast, phosphorous measurements during summer indicate that air from the Central Valley is unlikely to be a significant source of phosphorous to Lake Tahoe. Measurements of nitrogen and phosphorous in a forest fire plume clearly indicate that forest fires in the Sierras can be significant sources of nitrogen and phosphorous to Lake Tahoe. They also suggest that wood burning within the Tahoe Basin might be a significant "in basin" source of both nitrogen and phosphorous.

• Concentrations of fine particulate nitrogen measured over a 1-year period at a site in the Central Valley indicate that local concentrations peak in the later winter/early spring and that organic nitrogen is a significant component (typically ~ 20%) of the total nitrogen load. In addition, laboratory experiments have shown that significant portions of the organic nitrogen break down to form more bioavailable products such as ammonium in sunlight. These data will be useful inputs to future models that examine nitrogen transport from the Central Valley to the Sierras.

• Measurements performed during 1999 and 2000 have enabled the first reliable estimates of annual Lake Tahoe evaporation. Estimates of Lake Tahoe evaporation made using pan evaporation data and independently using energy budget and meteorologic data yield a value of approximately 35 inches for annual average Lake Tahoe evaporation. An updated water budget on Lake Tahoe has been completed using the new estimate of evaporation, with groundwater flow computed as the residual in the water budget. This updated water budget is based on a sounder foundation of data and analyses than previously reported budget estimates, and likely is to be more accurate than previous estimates.

• Groundwater flow into Lake Tahoe is computed as the residual in an improved water budget for Lake Tahoe, at an average of approximately 45,000 acre-feet per year between 1958-1997. The results indicate that total groundwater inflow is proportional to total stream inflow during any given water year. The results suggest that the magnitude of deep, low-frequency (many years) groundwater flow into (or out of) Lake Tahoe is small.

• Data intensive studies of methyl tertiary butyl ether (MTBE) groundwater contamination in the Tahoe Basin revealed a relatively fast-moving problem, with MTBE plumes from leaking underground fuel tanks threatening groundwater resources throughout the developed portions of the basin. Limited sampling of snow yielded no MTBE detects. Low levels of MTBE were confirmed in shallow groundwater of Pope Marsh. This contamination originated from the lake and migrated into the marsh because of reversals of groundwater flow directions induced by pumping from water supply wells.

• Groundwater flow and heat flow are inextricably coupled in the subsurface. Thus, by performing relatively simple temperature profile measurements in wells and boreholes, we can improve the understanding of groundwater flow patterns and magnitudes in the subsurface. Subsurface temperature profiles have been measured with high precision and accuracy by lowering a highly sensitive temperature probe into numerous wells and boreholes in the Tahoe Basin region. In the absence of groundwater flow, temperature normally increases steadily with depth because of normal geothermal heat flow from the deep subsurface toward the surface that is found everywhere on Earth. Several wells we have probed show such a normal temperature increase with depth near the bottoms of the wells, showing that there is little likelihood of much groundwater flow below the bottom of the well. Shallower portions of these wells, and the entire depth of other wells, exhibit abnormal changes of temperature with depth, reflecting the influence of groundwater flow in cooling or warming the subsurface. In many wells, we even have found temperature inversions, where temperatures actually become colder at greater depth. Such inversions indicate that the groundwater at depth originated as recharge from much higher surface elevations than the wellhead, where temperatures of the ground and the water are colder. These and many other observations will help to illuminate the hidden pathways of groundwater flow, including groundwater flow at depths below the bottom of wells and boreholes.

• Although much tree mortality in the Lake Tahoe Basin can be attributed indirectly to the short-term effects of the recent drought and the long-term effects of fire suppression, the proximal cause of death of most trees in the basin is because of a number of insects and pathogens. These results suggest that any management strategy must take into account the potential long-term affects of pathogens and insects.

• Carbon dating of peat deposits indicate that Pope Marsh is at least 2,300 years old. A water budget for the marsh shows that the current inflows are not adequate to have sustained the marsh throughout these millenia. Therefore, additional inflows to Pope Marsh must have existed. Increased lake levels resulting from the Lake Tahoe Dam have replaced some of the lost inflows, but this source of water vanishes when the lake drops to its original level during dry summer months or droughts. Long-term survival of the marsh may require restoration of some of the original inflows. This might be achieved by reducing groundwater pumpage, maintaining higher lake levels, or restoring river channels to reconnect Pope Marsh to the Upper Truckee Delta.

• We showed that mercury concentrations in trout in the Sierra Nevada, although variable, were uniformly below existing health standards. This finding indicates minimal risk for direct human health concerns (via fish consumption) within the region itself.

Analytical and Biomarkers. More than 55 distinct approaches and methods were developed during this research project; a few are highlighted here. Most of these are the result of identifying analytical bottlenecks in studies of pollutant impacts in the watershed ecosystems. The current toolkit of biomarkers for ecotoxicologic investigations is weighted heavily toward those that signify exposure. As effective as these are, we often do not know whether exposure has led to adverse effect. Also, the signal(s) used as the biomarker(s) of exposure often arise from specific cellular targets in specific organs and not from the individual as a whole. Directing our effort to targeted fractions of the individual can more likely assist us in making the linkage between exposure and adverse effect.

• Using methods of water soluble plastic embedment of embryonic fishes without prior fixation, we have produced high-resolution imaging of important molecular responses in cells and tissues. This enables localization of biomarkers of exposure, including stress proteins, cytochrome P450 isoforms, acetylcholinesterase, and metallothionein, and determination of their proximity to necrotic (apoptotic) cells and injured tissues (i.e., the biomarkers of adverse effect). The systems have enabled us to rapidly detect adverse effect from exposure to contaminant mixtures and diazinon, an organophosphate insecticide in the embryonic tissues of fishes. Because our emphasis is on multiple stressors, detecting adverse effects in early life stages permits us to examine subsequent life stages for alteration by these and other stressors.

• The 19F nuclear magnetic resonance (NMR) method was utilized to monitor the photodegradation of trifluralin directly in NMR tubes without extraction, cleanup, concentration, or chromatographic separation. This method will be an important tool in our continued investigation into fluorinated chemicals and their disposition and fate in the environment.

• Liver cell culture assays for mixed-function oxidases have continued to be perfected and are being applied to the study of P450 activity of cormorant embryos collected from San Francisco Bay. Actions of cadmium and other environmentally important metals on the secretion of cholinesterases are being studied using liver, nerve, and muscle cultures and developing embryos.

• We developed and validated an antibody method to estimate the testosterone content, and hence reproductive state, of mammals using fecal assays. This method provides a noninvasive means of examining the reproductive state of threatened or endangered species. Wildlife agencies, investigators, and the U.S. EPA all will find this a beneficial tool in their work.

• New formats for immunoassays have been developed that are faster, less expensive, and in some cases field portable. One of these formats performs the immunoassay on the surface of a standard compact disk (CD). This research will allow us to use the huge investment in developing portable CD players to carry out sophisticated analytical chemistry with off-the-shelf equipment.

• To rapidly and inexpensively assess exposure to toxic substances, immunoassays have been developed for triazine herbicides, pyrethroid and organophosphate insecticides, mercury, and dioxins. A novel chelate-based assay that is conducted analogously to an immunoassay has been developed for the detection of divalent mercury, the inorganic precursor to organic methylmercury, which is the most toxic form of mercury. CEHR researchers are working on tools to measure the overall level of environmental stresses animals and plants have experienced. They have developed techniques to monitor the level of esterases in animals, and are exploring the potential for using the presence and relative amounts of lipid diols and epoxides as monitoring tools.

• We developed a fast, selective, and sensitive (300 pg) method of analyzing synthetic pyrethroids (esfenvalerate and cis- and trans-permethrin) in natural surface waters. Until now, no satisfactory method for this type of analysis existed. Detection and analysis of water samples thought to contain pyrethroid pesticides are important because many aquatic organisms are highly susceptible to pyrethroid intoxication, and these types of pesticides are widely used. Our new analytical method will allow researchers to assess the risks posed by these pesticides, and ultimately will help agricultural and environmental managers create new or adjust existing regulations concerning pyrethroid pesticide usage.

• A quick, noninvasive, inexpensive field test based on cholinesterase assays has been developed to detect a variety of stresses in wildlife.

• Soil microbial community assays, including DNA probes, are being used for understanding the role of microbes in pollutant transport and fate.

• Analysis of biological community markers in sediment cores, such as alkanes and pigments, are being used to obtain a historical time scale of trends in impacted lakes.

• Methods for evaluating historical trends in aquatic and forest ecosystems using sediment cores and tree ring samples have been applied with encouraging results.

• Noninvasive assays for sex hormones, such as testosterone in mice feces, are being used to assess the impact of pesticides on reproduction in field situations.

• Rapid, inexpensive, sorbent-based assays for mercury and lead have been developed, reducing one of the key obstacles in studies of the impacts of these pollutants.

• Analysis of biochemical indicators of air pollution in tree rings is opening the way to understanding long-term (centuries) trends in forest effects.

• Development of new markers for endocrine disruption by chemicals is addressing the rising awareness of this major effect by organic pollutants.

• Phospholipid fatty acid analysis of a soil microbial community can be coupled with 13C isotope tracer analysis to identify groups of microorganisms able to carry out a particular function in complex environmental samples.

• We developed a real-time quantitative polymerase chain reaction (PCR) method for detection of the MTBE-degrading bacterial strain PM1. This is significant because it is now possible to quantify the density of a naturally occurring bacterium involved in MTBE biodegradation in groundwater, and to relate densities to biodegradation rates. The quantitative PCR method for PM1 will be commercially available through Regenesis, Inc. Currently, the method is being used by industry (responsible parties, engineering firms) to estimate the potential for MTBE bioremediation by biostimulation.

• Specific lipid biomarkers were used to detect and track changes in the populations of certain genera of microorganisms. For example, 10Me16:0 and i17:1 are lipid biomarkers for two genera of sulfate reducing bacteria, Desulfobacter and Desulfovibrio.

• Quantitative PCR-based methods were developed that permit quantification of initially low population densities of environmental microorganisms without requiring culturing of the organisms. This method was applied in quantifying nitrifying organisms and bacteria capable of biodegrading MTBE.

• We have discovered that calcium- and calmodulin-dependent protein kinase (CaM-kinase II) in insects (used as a model in invertebrates) is a good biomarker for long-term stress given by pyrethroids and dichlorodiphenyltrichloroethane-type insecticides. CaM-kinase II is an important enzyme needed to transmit the stimulatory signals from the sensory cells to the next effector cells. When insect populations are subjected to insecticidal selection pressure from multigenerations, the resulting knockdown resistant strains show markedly reduced levels of CaM-kinase II.

• We have compared three major plant defense signaling components—protein kinase C (PKC), G-proteins, and phospholipase C-gamma—in young rice plants as potential biomarkers of stress. Among these three parameters, PKC has been by far the most responsive and reliable marker. Its levels changed even at a very incipient stage of invasion by the rice blast fungus, indicating that this approach may become an important tool in monitoring the health of rice plants. Interestingly, the changing levels of PKC correlated well with those of free salcylic acid, meaning that these two components are coupled in the defense signaling pathway.

Transport and Fate. Deterministic and statistical models of transport in soils, atmosphere, surface, and groundwaters were developed and improved by Center researchers. These models range in scale from origin and movement of groundwater and assessment of long-term degradation of these waters to regional-scale atmospheric models used to calculate transport of air pollutants from source areas within large geographic areas. They also have been coupled with hydrologic models of runoff to quantify patterns of erosion and input of nutrients and other chemicals to lakes and rivers.

• We developed a new, quantitative, geologic method for characterizing subsurface heterogeneity that is important for contaminant transport investigations. Contained in a package of computer codes called TPROGS, this method is increasingly in demand by groundwater investigators in government agencies, research laboratories, academia, and environmental consulting. Much of TPROGS has been incorporated into a popular groundwater modeling package (Groundwater Modeling System).

• We developed a new, highly efficient transport modeling algorithm and code for realistically simulating fate and transport of groundwater contaminants in three dimensions, including effects of matrix diffusion on groundwater remediation and on long-term sustainability of groundwater quality. Like TPROGS, this code is in demand from a variety of users and is being adopted by the USGS for their popular MODFLOW-2000 modeling codes.

• A new method for probabilistically quantifying the origins and ages of groundwaters arriving at discharge points (e.g., wetlands, wells) was developed that also rigorously accounts for the physical process involved in pollutant transfer between different geologic materials. Results indicate that the currently observed deterioration in groundwater quality in a typical alluvial groundwater basin is because of land use practices in the 1940s and 1950s, and that the deterioration may continue for many decades, thereby eventually impacting any wetlands and streams that are sustained by groundwater discharge.

• A regional-scale hydrologic model has been coupled to a regional-scale atmospheric model and validated by hydrologic/climatic data for a severe drought period in California (April 1989).

• Research on volatile organic chemical vapor diffusion, sorption, and biodegradation mechanisms in soils has been used to improve simulation models and provide better capability for predicting the fate and transport of pesticides and other organic chemicals from the soil to the atmosphere, surface water, and groundwater. The new equations for predicting the soil gas diffusion coefficients now provide much more realistic estimates than previously available. We clearly have shown that organic vapors adsorb very strongly to soils when they are very dry, and that the soils release the org

References:

Borhan B, Nourooz Zadeh J, Uematsu T, Hammock BD, Kurth MJ. Stereochemical aspects of cytosolic epoxide hydrolase hydration of methyl diepoxystearates. Tetrahedron 1993;49(13):2601-2612.

Fan S, Scow KM. Biodegradation of trichloroethylene and toluene by indigenous microbial populations in soil. Applied and Environmental Microbiology 1993;59(6):1911-1918.

Grant DF, Storms DH, Hammock BD. Molecular cloning and expression of murine liver soluble epoxide hydrolase. Journal of Biological Chemistry 1993;268(23):17628-17633.

Hansen LD, Maier KJ, Knight AW. The effect of sulfate on the bioaccumulation of selenate by chironomus decorus and daphnia magna. Archives of Environmental Contamination and Toxicology 1993;25:72-78.

Huang TL, Székács A, Uiatsu T, Kuwano E, Parkinson A, Hammock BD. Hydrolysis of carbonates, thiocarbonates, carbamates, and carboxylic esters of α naphthol, β naphthol, and p nitrophenol by human, rat, and mouse liver carboxylesterases. Pharmaceutical Research 1993;10(5):639-648.

Lucas AD, Jones AD, Goodrow MH, Saiz SG, Blewett C, Seiber JN, Hammock BD. Determination of atrazine metabolites in human urine: development of a biomarker of exposure. Chemical Research in Toxicology 1993;6(1):107-116.

Marco MP, Gee SJ, Cheng HM, Liang ZY, Hammock BD. Development of an enzyme linked immunosorbent assay for carbaryl. Journal of Agricultural and Food Chemistry 1993;41(3):423-430.

Marco MP, Nasiri N, Kurth MK, Hammock BD. Enzyme linked immunosorbent assay for the specific detection of the mercapturic acid metabolites of naphthalene. Chemical Research in Toxicology 1993;6(3):284-293.

Zabic JM, Seiber JN. Atmospheric transport of organophosphate pesticides from California’s Central Valley to the Sierra Nevada Mountains. Journal of Environmental Quality 1993;22:80-90.

Lucas AD, Bekheit HKM, Goodrow MH, Jones AD, Kullman S, Matsumura F, Woodrow JE, Seiber JN, Hammock BD. Development of antibodies against hydroxy s triazines: application to environmental samples. Journal of Agricultural and Food Chemistry 1993;41:1523-1529.

Bekheit HK, Lucas AD, Gee SJ, Harrison RO, Hammock BD. Development of an enzyme linked immunosorbent assay for the β exotoxin of Bacillus thuringeinsis. Journal of Agricultural and Food Chemistry 1993;41:1530-1536.

Goldman CR, Jassby AD, Hackley SH. Decadal, interannual, and seasonal variability in enrichment bioassays at Lake Tahoe (California Nevada, U.S.A.). Canadian Journal of Fisheries and Aquatic Sciences 1993;50(7):1489-1496.

Thomas TC, Székács A, Hammock BD, Wilson BW, McNamee GM. Affinity chromatography of neuropathy target esterase. Chemical Biological Interactions 1993;87(1-3):347-360.

Amali S, Petersen LW, Rolston DE, Moldrup P. Modeling multicomponent volatile organic and water vapor absorption on soils. Journal of Hazardous Materials 1994;36(1):89-108.

Bekheit HK, Lucas AD, Szurdoki F, Gee SJ, Hammock BD. An enzyme immunoassay for the environmental monitoring of the herbicide bromacil. Journal of Agricultural and Food Chemistry 1993;41(11):2220-2227.

McCutchen BF, Uiatsu T, Székács A, Huang TL, Shiotsuki T, Lucas A, Hammock BD. Development of surrogate substrates for juvenile hormone esterase. Archives of Biochemistry and Biophysics 1993;307:231-241.

Marco MP, Hammock BD, Kurth MJ. Hapten design and development of an ELISA (enzyme linked immunosorbent assay) for the detection of the mercapturic acid conjugates of naphthalene. Journal of Organic Chemistry 1993;58:7548-7556.

Schneider P, Goodrow MH, Gee SJ, Hammock BD. A highly sensitive and rapid ELISA for the urea herbicides diuron, monuron and linuron. Journal of Agricultural and Food Chemistry 1994;42:413-422.

Karu AE, Goodrow MH, Schmidt DJ, Hammock BD, Bigelow MW. Synthesis of haptens and derivation of monoclonal antibodies for immunoassay of the phenylurea herbicide diuron. Journal of Agricultural and Food Chemistry 1994;42:301-309.

Moldrup P, Yamaguchi T, Rolston DE, Vestergaard K, Hansen JA. Removing numerically induced dispersion from finite difference models for solute and water transport in unsaturated soils. Soil Science 1994;157:153-161.

Moldrup P, Poulsen TG, Rolston DE, Yamaguchi T, Hansen JA. Integrated flux model for unsteady transport of trace organic chemicals in soils. Soil Science 1994;157:137-152.

Henderson JD, Yamamoto JT, Fry DM, Seiber JN, Wilson BW. Oral and dermal toxicity of organophosphate pesticides in the domestic pigeon (Columba livia). Bulletin of Environmental Contamination and Toxicology 1994;52(5):633-640.

Jassby AD, Reuter JE, Axler RP, Goldman CR, Hackley SH. Atmospheric deposition of nitrogen and phosphorus in the annual nutrient load of Lake Tahoe (California Nevada). Water Resources Research 1994;30(7):2207-2216.

Hantush MM, Mariño MA. Two dimensional stochastic analysis in leaky aquifers and optimal estimation in aquifers: random recharge. Water Resources Research 1994;30(2):559-569.

Hantush MM, Mariño MA. One dimensional stochastic analysis in leaky aquifers subject to random leakage. Water Resources Research 1994;30(2):549-558.

Shiotsuki T, Huang TL, Uematsu T, Bonning BC, Ward VK, Hammock BD. Juvenile hormone esterase purified by affinity chromatography with 8 mercapto 1,1,1 trifluoro 2 octanone as a rationally designed ligand. Protein Expression and Purification 1994;5:296-306.

Mu DY, Scow KM. Effect of trichloroethylene (TCE) and toluene concentrations on TCE and toluene biodegradation and the population density of TCE and toluene degraders in soil. Applied Environmental Microbiology 1994:2661-2665.

Ben-Jemaa F, Mariño MA, Loaiciga HA. Multivariate geostatistical design of groundwater monitoring networks. Journal of Water Resources Planning and Management 1994;120(4):505-522.

Scow KM, Somasco O, Gunapala N, Lau S, Venette R, Ferris H, Miller R, Shennan C. Transition from conventional to low-input agriculture changes soil fertility and biology. California Agriculture 1994;48:20-26.

Petersen LW, Rolston DE, Moldrup P, Yamaguchi T. Volatile organic vapor diffusion and adsorption in soils. Journal of Environmental Quality 1994;23:799-805.

Grant DF, Spearow J, Storms DH, Edelhoff S, Adler DA, Disteche CM, Taylor BA, Hammock BD. Chromosomal mapping and expression levels of a mouse soluble epoxide hydrolase gene. Pharmacogenetics 1994;4:64-72.

Ward VK, Hammock BD, Choudary PV. A microtiter plate assay for the determination of protein deglycosylation. BioTechniques 1994;16:1037-1038.

Kramer PM, Marco MP, Hammock BD. Development of a selective enzyme linked immunosorbent assay for 1 naphthol the major metabolite of carbaryl (1 naphthyl n methylcarbamate). Journal of Agricultural and Food Chemistry 1994;42:934-943.

Jassby AD, Powell TM. Hydrodynamic influences on interannual chlorophyll variability in an estuary: Upper San Francisco Bay Delta (California, U.S.A.). Estuarine Coastal and Shelf Science 1994;39:595-618.

Lee JV, Whaling CS, Lasley BL, Marler P. Validation of an enzyme immunoassay for measurient of excreted estrogen and testosterone metabolites in the white crowned sparrow (Zonotrichia leucophrys oriantha). Zoo Biology 1995;14:97-106.

Petersen LW, Thomsen A, Moldrup P, Jacobsen OH, Rolston DE. High resolution time domain reflectometry: sensitivity dependency on probe-design. Soil Science 1995;159:149-154.

Seifert J, Wilson BW. Solubilization of neuropathy target esterase and other phenyl valerate carboxylesterases from chicken embryonic brain by phospholipase. Comparative Biochemistry and Physiology 1994;108C(3):337-341.

Hantush MM, Mariño MA. Continuous time stochastic analysis of groundwater flow in heterogeneous aquifers. Water Resources 1995;31(3):565-575.

Jassby AD, Kimmerer WJ, Monismith SG, Armor C, Cloern JE, Powell TM, Schubel JR, Vendlinski TJ. Isohaline position as a habitat indicator for estuarine populations. Ecological Applications 1995;5(1):272-289.

Lucas AD, Gee SJ, Hammock BD, Seiber JN. Integration of immunochemical methods with other analytical techniques for pesticide residue determination. Journal of AOAC INTERNATIONAL 1995;78:585-591.

McCutchen BF, Székács A, Huang TL, Shiotsuki T, Hammock BD. Characterization of a spectrophotometric assay for juvenile hormone esterase. Insect Biochemistry and Molecular Biology 1995;25:119-126.

Wortberg M, Kreissig SB, Jones G, Rocke DM, Hammock BD. An immunoarray for the simultaneous determination of multiple triazine herbicides. Analytica Chimica Acta 1995;304:339-352.

Beetham JK, Grant D, Arand M, Garbarino J, Kiyosue T, Pinot F, Oesch F, Belknap WR, Shinozaki K, Hammock BD. Gene evolution of epoxide hydrolases and recommended nomenclature. DNA and Cell Biology 1995;14:61-71.

Petersen LW, Moldrup P, El Farhan YH, Jacobsen OH, Yamaguchi T, Rolston DE. The effect of moisture and soil texture on the adsorption of organic vapors. Journal of Environmental Quality 1995;24:752-759.

Pinot R, Grant DF, Beetham JK, Parker AG, Borhan B, Landt S, Jones AD, Hammock BD. Molecular and biochemical evidence for the involvement of the asp 333 his 523 pair in the catalytic mechanism of soluble epoxide hydrolase. Journal of Biological Chemistry 1995;270:7968-7974.

Szurdoki F, Kido H, Hammock BD. Development of rapid mercury assays: synthesis of sulfur- and mercury containing conjugates. Bioconjugate Chemistry 1995;6:145-149.

Suchanek TH, Richerson PJ, Holts LJ, Lamphere BA, Woodmansee CE, Slotton DG, Harner EJ, Woodward LA. Impacts of mercury on benthic invertebrate populations and communities within the aquatic ecosystem of Clear Lake, California. Water, Air, and Soil Pollution 1995;80:951-960.

Bennett WA, Ostrach DJ, Hinton DE. Larval striped bass condition in a drought stricken estuary: evaluating pelagic food web limitation. Ecological Applications 1995;5:680-692.

Carroll JJ, Liu M. An eulerian model of dispersion in the convective boundary layer using explicit periodic advections. Journal of Applied Meteorology 1995;34:2449-2461.

Brett MT, Goldman CR, Lubnow FS, Bracher A, Brandt D, Brandt O, Mller Solger A. Impact of a major soil fumigant spill on the planktonic ecosystem of Shasta Lake, California. Canadian Journal of Fisheries and Aquatic Sciences 1995;52:1247-1256.

Bossio DA, Scow KM. Impact of carbon and flooding on the metabolic diversity of microbial communities in soils. Applied and Environmental Microbiology 1995;61:4043-4050.

Scow KM, Fan S, Johnson C, Ma GM. Biodegradation of sorbed chemicals in soil. Environmental Health Perspectives 1995;103:93-95.

Ergas SJ, Kinney K, Fuller ME, Scow KM. Characterization of a compost biofiltration system degrading dichloromethane. Biotechnology and Bioengineering 1994;44:1048.

Fuller ME, Mu DY, Scow KM. Biodegradation of trichloroethylene and toluene by indigenous microbial populations in vadose sediments. Microbial Ecology 1995;29:311-325.

Hoyle BL, Scow KM, Fogg GE, Darby JL. Effect of carbon:nitrogen ratio on kinetics of phenol biodegradation by Acinetobacter johnsonii in saturated sand. Biodegradation 1995;6:283-293.

Fry DM. Reproductive effects in birds exposed to pesticides and industrial chemicals. Environmental Health Perspectives 1995;103:165-171.

Ben Jemaa F, Mariño MA, Loaiciga HA. Sampling design for contaminant distribution in lake sediments. Journal of Water Resources Planning and Management 1995;121:71-79.

Jassby AD, Goldman CR, Reuter JE. Long term change in Lake Tahoe (California Nevada, USA) and its relation to atmospheric deposition of algal nutrients. Archiv fur Hydrobiologie 1995;135(1):1-21.

Maybury SA, Crosby DG. 19FNMR as an analytical tool for fluorinated agrochemical research. Journal of Agricultural and Food Chemistry 1995;43(7):1854-1848.

Ward VK, Kreissig SB, Hammock BD, Choudary PV. Generation of an expression library in the baculovirus expression vector system. Journal of Virological Methods 1995;53:263-272.

Székács A, Hammock BD. Development of an enzyme linked immunosorbent assay for the detection of the triazole fungicide myclobutanil. Journal of Agricultural and Food Chemistry 1995;43(8):2083-2091.

Marco MP, Chiron S, Gascon J, Hammock BD, Barcelo D. Validation of two immunoassay methods for environmental monitoring of carbaryl and 1 naphthol in ground water samples. Analytica Chimica Acta 1995;311:319-329.

Ward VK, Schneider PG, Kreissig SB, Hammock BD, Choudary PV. Cloning, sequencing and expression of the fab fragment of a monoclonal antibody to the herbicide atrazine. Protein Engineering 1993;6(8):981-988.

Pinot F, Grant DF, Spearow JL, Parker AG, Hammock BD. Differential regulation of soluble epoxide hydrolase by clofibrate and sexual hormones in the liver and kidneys of mice. Biochemical Pharmocology 1995;50(4):501-508.

Borhan B, Ko Y, Mackay C, Wilson BW, Kurth MJ, Hammock BD. Development of surrogate substrates for neuropathy target esterase. Biochimica et Biophysica Acta 1995;1250:171-182.

Lucas AD, Goodrow MH, Seiber JN, Hammock BD. Development of an ELISA for the N dealkylated s triazines: application to environmental and biological samples. Food and Agricultural Immunology 1995;7:227-241.

Borhan B, Mebrahtu T, Nazarian S, Kurth MJ, Hammock BD. Improved radiolabeled substrates for soluble epoxide hydrolase. Analytical Biochemistry 1995;231:188-200.

Borhan B, Jones AD, Pinot F, Grants DF, Kurth MJ, Hammock BD. Mechanism of soluble epoxide hydrolase. Journal of Biological Chemistry 1995;270(45):26923-26930.


Journal Articles: 241 Displayed | Download in RIS Format

Other center views: All 403 publications 295 publications in selected types All 241 journal articles

Type Citation Sub Project Document Sources
Journal Article Altevogt AS, Rolston DE, Venterea RT. Density and pressure effects on the transport of gas phase chemicals in unsaturated porour media. Water Resources Research 2003;39(3):1062-1071, Art. No. 1061. R825433 (Final)
not available
Journal Article Altevogt AS, Rolston DE, Whitaker S. New equations for binary gas transport in porous media, Part 1: equation development. Advances in Water Resources 2003;26(7):695-715. R825433 (Final)
not available
Journal Article Altevogt AS, Rolston DE, Whitaker S. New equations for binary gas transport in porous media, Part 2: experimental validation. Advances in Water Resources 2003;26(7):717-723. R825433 (Final)
not available
Journal Article Amali S, Rolston DE, Yamaguchi T. Transient multicomponent gas-phase transport of volatile organic chemicals in porous media. Journal of Environmental Quality 1996;25(5):1041-1047. R825433 (Final)
not available
Journal Article Anastasio C, McGregor KG. Photodestruction of dissolved organic nitrogen species in fog waters. Aerosol Science and Technology 2000;32(2):106-119. R825433 (Final)
not available
Journal Article Anastasio C, McGregor KG. Chemistry of fog waters in California's Central Valley: 1. In situ photoformation of hydroxyl radical and singlet molecular oxygen. Atmospheric Environment 2001;35(6):1079-1089. R825433 (Final)
not available
Journal Article Anderson MJ, Miller MR, Hinton DE. In vitro modulation of 17-beta-estradiol-induced vitellogenin synthesis: Effects of cytochrome P4501A1 inducing compounds on rainbow trout (Oncorhynchus mykiss) liver cells. Aquatic Toxicology 1996;34(4):327-350 R825433 (Final)
not available
Journal Article Anderson MJ, Olsen H, Matsumura F, Hinton DE. In vivo modulation of 17 beta-estradiol-induced vitellogenin synthesis and estrogen receptor in rainbow trout (Oncorhynchus mykiss) liver cells by beta-naphthoflavone. Toxicology and Applied Pharmacology 1996;137(2):210-218 R825433 (Final)
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Journal Article Arocha MA, Jackman AP, McCoy BJ. Adsorption kinetics of toluene on soil agglomerates: soil as a biporous sorbent. Environmental Science & Technology 1996;30(5):1500-1507. R825433 (Final)
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  • Journal Article Aston LS, Seiber JN. Exchange of airborne organophosphorus pesticides with pine needles. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes 1996;31(4):671-698 R825433 (Final)
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    Journal Article Aston LS, Seiber JN. Methods for the comparative analysis of organophosphate residues in four compartments of needles of Pinus ponderosa. Journal of Agricultural and Food Chemistry 1996;44(9):2728-2735. R825433 (Final)
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    Journal Article Bale AE. Modeling aquatic mercury fate in Clear Lake, Calif. Journal of Environmental Engineering 2000;126(2):153-163. R825433 (Final)
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    Journal Article Billitti JE, Lasley BL, Wilson BW. Development and validation of a fecal testosterone biomarker in Mus musculus and Peromyscus maniculatus. Biology of Reproduction 1998;59(5):1023-1028. R825433 (Final)
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    Journal Article Bonning BC, Loher W, Hammock BD. Recombinant juvenile hormone esterase as a biochemical anti-juvenile hormone agent: effects on ovarian development in Acheta domesticus. Archives of Insect Biochemistry and Physiology 1997;34(3):359-368. R825433 (Final)
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    Journal Article Borhan B, Hammock B, Seifert J, Wilson BW. Methyl and phenyl esters and thioesters of carboxylic acids as surrogate substrates for microassay of proteinase K esterase activity. Fresenius Journal of Analytical Chemistry 1996;354(4):490-492 R825433 (Final)
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    Journal Article Borjesson DL, Boyce WM, Gardner IA, DeForge J, Lasley B. Pregnancy detection in bighorn sheep (Ovis canadensis) using a fecal-based enzyme immunoassay. Journal of Wildlife Diseases 1996;32(1):67-74. R825433 (Final)
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    Journal Article Botsford LW, Brittnacher JG. Viability of Sacramento River Winter-run chinook salmon. Conservation Biology 1998;12(1):65-79. R825433 (Final)
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    Journal Article Bruns MA, Hanson JR, Mefford J, Scow KM. Isolate PM1 populations are dominant and novel methyl tert-butyl ether-degrading bacteria in compost biofilter enrichments. Environmental Microbiology 2001;3(3):220-225. R825433 (Final)
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    Journal Article Burruel VR, Raabe OG, Overstreet JW, Wilson BW, Wiley LM. Paternal effects from methamidophos administration in mice. Toxicology and Applied Pharmacology 2000;165(2):148-157. R825433 (Final)
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    Journal Article Cahill TM, Perley BP, Anderson DW. Elemental profiles in feathers. International Journal of PIXE 1997;7(1-2):53-69. R825433 (Final)
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    Journal Article Cahill TM, Anderson DW, Albert RA, Perley BP, Johnson DR. Elemental profiles in feather samples from a mercury-contaminated lake in central California. Archives of Environmental Contamination and Toxicology 1998;35(1):75-81. R825433 (Final)
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    Journal Article Calderon FJ, Jackson LE, Scow KM, Rolston DE. Microbial responses to simulated tillage in cultivated and uncultivated soils. Soil Biology & Biochemistry 2000;32(11-12):1547-1559. R825433 (Final)
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    Journal Article Calderon FJ, Jackson LE, Scow KM, Rolston DE. Short-term dynamics of nitrogen, microbial activity, and phospholipid fatty acids after tillage. Soil Science Society of America Journal 2001;65(1):118-126. R825433 (Final)
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    Journal Article Carle SF, Fogg GE. Transition probability-based indicator geostatistics. Mathematical Geology 1996;28(4):453-476. R825433 (Final)
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    Journal Article Carle SF, Fogg GE. Modeling spatial variability with one and multidimensional continuous-lag Markov chains. Mathematical Geology 1997;29(7):891-918. R825433 (Final)
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    Journal Article Chen D, Rolston DE, Yamaguchi T. Calculating partition coefficients of organic vapors in unsaturated soil and clays. Soil Science 2000;165(3):217-225. R825433 (Final)
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    Journal Article Chen D, Rolston DE, Moldrup P. Coupling diazinon volatilization and water evaporation in unsaturated soils: I. Water transport. Soil Science 2000;165(9):681-689. R825433 (Final)
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    Journal Article Chen D, Rolston DE. Coupling diazinon volatilization and water evaporation in unsaturated soils: II. Diazinon transport. Soil Science 2000;165(9):690-698. R825433 (Final)
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    Journal Article Choi MH, Cech JJ, Lagunas-Solar MC. Bioavailability of methylmercury to Sacramento blackfish (Orthodon microlepidotus): Dissolved organic carbon effects. Environmental Toxicology and Chemistry 1998;17(4):695-701 R825433 (Final)
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    Journal Article Choi MH, Cech JJ. Unexpectedly high mercury level in pelleted commercial fish feed. Environmental Toxicology and Chemistry 1998;17(10):1979-1981. R825433 (Final)
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    Journal Article Chu XF, Basagaoglu H, Marino MA, Volker RE. Aldicarb transport in subsurface environment: comparison of models. Journal of Environmental Engineering 2000;126(2):121-129. R825433 (Final)
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    Journal Article Chu XF, Marino MA. Semidiscrete pesticide transport modeling and application. Journal of Hydrology 2004;285(1-4):19-40. R825433 (Final)
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    Journal Article Cisneros-Mata MA, Botsford LW, Quinn JF. Projecting viability of Totoaba macdonaldi, a population with unknown age-dependent variability. Ecological Applications 1997;7(3):968-980. R825433 (Final)
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    Journal Article Clark SL, Teh SJ, Hinton DE. Tissue and cellular alterations in Asian clam (Potamocorbula amurensis) from San Francisco Bay: toxicological indicators of exposure and effect? Marine Environmental Research 2000;50(1-5):301-305. R825433 (Final)
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    Journal Article Datta S, Ohyama K, Dunlap DY, Matsumura F. Evidence for organochlorine contamination in tissues of salmonids in Lake Tahoe. Ecotoxicology and Environmental Safety 1999;42(1):94-101 R825433 (Final)
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    Journal Article Davis JA, Fry DM, Wilson BW. Hepatic ethoxyresorufin-O-deethylase activity and inducibility in wild populations of double-crested cormorants (Phalacrocorax auritus). Environmental Toxicology and Chemistry 1997;16(7):1441-1449. R825433 (Final)
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    Journal Article Debernard S, Morisseau C, Severson TF, Feng L, Wojtasek H, Prestwich GD, Hammock BD. Expression and characterization of the recombinant juvenile hormone epoxide hydrolase (JHEH) from Manduca sexta. Insect Biochemistry and Molecular Biology 1998;28(5-6):409-419. R825433 (Final)
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    Journal Article Lalitkumar PGL, Sengupta J, Dhawan L, Sharma DN, Lasley BL, Overstreet JW, Ghosh D. Anti-nidatory effect of vaginally administered fumagillin in the rhesus monkey. Contraception 2000;62(3):155-159 R825433 (Final)
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    Journal Article Dunlap DY, Matsumura F. Development of broad spectrum antibodies to heat shock protein 70s as biomarkers for detection of multiple stress by pollutants and environmental factors. Ecotoxicology and Environmental Safety 1997;37(3):238-244. R825433 (Final)
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    Journal Article El-Farhan YH, Scow KM, de Jonge LW, Rolston DE, Moldrup P. Coupling transport and biodegradation of toluene and trichloroethylene in unsaturated soils. Water Resources Research 1998;34(3):437-445. R825433 (Final)
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    Journal Article El-Farhan YH, Scow KM, Fan S, Rolston DE. Kinetics of trichloroethylene cometabolism and toluene biodegradation: model application to soil batch experiments. Journal of Environmental Quality 2000;29(3):778-786. R825433 (Final)
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    Journal Article Elbert RA, Anderson DW. Mercury levels, reproduction, and hematology in western grebes from three California lakes, USA. Environmental Toxicology and Chemistry 1998;17(2):210-213. R825433 (Final)
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    Journal Article Fan TW-M, Lane AN, Higashi RM. Selenium biotransformations by a euryhaline microalga isolated from a saline evaporation pond. Environmental Science & Technology 1997;31(2):569-576. R825433 (Final)
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  • Journal Article Fan TWM, Lane AN, Pedler J, Crowley D, Higashi RM. Comprehensive analysis of organic ligands in whole root exudates using nuclear magnetic resonance and gas chromatography mass spectrometry. Analytical Biochemistry 1997;251(1):57-68. R825433C007 (Final)
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    Journal Article Fan TWM, Lane AN, Shenker M, Bartley JP, Crowley D, Higashi RM. Comprehensive chemical profiling of gramineous plant root exudates using high-resolution NMR and MS. Photochemistry 2001;57(2):209-221. R825433 (Final)
    R825433C007 (Final)
    R825960 (2001)
    R825960 (Final)
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    Journal Article Fan TWM, Teh SJ, Hinton DE, Higashi RM. Selenium biotransformations into proteinaceous forms by foodweb organisms of selenium-laden drainage waters in California. Aquatic Toxicology 2002;57(1-2):65-84. R825433 (Final)
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    Journal Article Fan TWM, Higashi RM, Lane AN. Chemical characterization of a chelator-treated soil humate by solution-state multinuclear two-dimensional NMR with FTIR and pyrolysis-GCMS. Environmental Science & Technology 2000;34(9):1636-1646. R825433C007 (Final)
    R825960 (1999)
    R825960 (2000)
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    Journal Article Florsheim JL, Mount JF. Changes in lowland floodplain sedimentation processes: pre-disturbance to post-rehabilitation, Cosumnes River, CA. Geomorphology 2003;56(3-4):305-323. R825433 (Final)
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    Journal Article Fogg GE, Noyes CD, Carle SF. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting. Hydrogeology Journal 1998;6(1):131-143 R825433 (Final)
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    Journal Article Fry DM. Vulnerability of avian populations to environmental pollutants. Comments on Toxicology 1996;5(4-5):401-414. R825433 (Final)
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    Journal Article Fuller ME, Scow KM. Effects of toluene on microbially-mediated processes involved in the soil nitrogen cycle. Microbial Ecology 1996;32(2):171-184 R825433 (Final)
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    Journal Article Fuller ME, Scow KM. Impact of trichloroethylene and toluene on nitrogen cycling in soil. Applied and Environmental Microbiology 1997;63(10):4015-4019. R825433 (Final)
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    Journal Article Gascon J, Oubina A, Ferrer I, Onnerfjord P, Marko Varga G, Hammock BD, Marco MP, Barcelo D. Performance of two immunoassays for the determination of atrazine in seawater samples as compared with on-line solid phase extraction liquid chromatography diode array detection. Analytica Chimica Acta 1996;330(1):41-51. R825433 (Final)
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    Journal Article Goldman CR, Reuter JE. Predictive model enables long-term planning. NAEP News 1997;22(5):12. R825433 (Final)
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    Journal Article Goldman CR, Reuter JE. President Clinton and Vice-President Gore focus attention on ecosystem research and environmental restoration at Lake Tahoe. Aslo Bulletin. 1997;6(2):773-790. R825433 (Final)
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    Journal Article Goodrow MH, Hammock BD. Hapten design for compound-selective antibodies: ELISAS for environmentally deleterious small molecules. Analytica Chimica Acta 1998;376(1):83-91. R825433 (Final)
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    Journal Article Grant DF, Greene JF, Pinot F, Borhan B, Moghaddam MF, Hammock BD, McCutcheon B, Ohkawa H, Luo G, Guenther TM. Development of an in situ toxicity assay system using recombinant baculoviruses. Biochemical Pharmocology 1996;51(4):503-515. R825433 (Final)
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    Journal Article Greene JF, Williamson KC, Newman JW, Morisseau C, Hammock BD. Metabolism of monoepoxides of methyl linoleate: bioactivation and detoxification. Archives of Biochemistry and Biophysics 2000;376(2):420-432. R825433 (Final)
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    Journal Article Greene JF, Newman JW, Williamson KC, Hammock BD. Toxicity of epoxy fatty acids and related compounds to cells expressing human soluble epoxide hydrolase. Chemical Research in Toxicology 2000;13(4):217-226 R825433 (Final)
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    Journal Article Grossman YL, Ustin SL, Jacquemoud S, Sanderson EW, Schmuck G, Verdebout J. Critique of stepwise multiple linear regression for the extraction of leaf biochemistry information from leaf reflectance data. Remote Sensing Of Environment. 1996;56(3):182-193. R825433 (Final)
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    Journal Article Gunapala N, Scow KM. Dynamics of soil microbial biomass and activity in conventional and organic farming systems. Soil Biology & Biochemistry 1998;30(6):805-816. R825433 (Final)
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    Journal Article Gusman AJ, Marino MA. Analytical modeling of nitrogen dynamics in soils and ground water. Journal of Irrigation and Drainage Engineering 1999;126(6):330-337. R825433 (Final)
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    Journal Article Hall GL, Mourer CR, Shibamoto T. Development and validation of an analytical method for naled and dichlorvos in air. Journal of Agricultural and Food Chemistry 1997;45(1):145-148. R825433 (Final)
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    Journal Article Hamm JT, Wilson BW, Hinton DE. Organophosphate-induced acetylcholinesterase inhibition and embryonic retinal cell necrosis in vivo in the teleost (Oryzias latipes). NeuroToxicology 1998;19(6):853-869. R825433 (Final)
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    Journal Article Hamm JT, Hinton DE. The role of development and duration of exposure to the embryotoxicity of diazinon. Aquatic Toxicology 2000;48(4):403-418. R825433 (Final)
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    Journal Article Hamm JT, Wilson BW, Hinton DE. Increasing uptake and bioactivation with development positively modulate diazinon toxicity in early life stage medaka (Oryzias latipes). Toxicological Sciences 2001;61(2):304-313. R825433 (Final)
    not available
    Journal Article Hammock BD, Casida KF. For the fun of science: Discussion. Archives of Insect Biochemistry and Physiology 1998;37(1):1-7 R825433 (Final)
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    Journal Article Hansen ME, Wilson BW. Oxime reactivation of RBC acetylcholinesterases for biomonitoring. Archives of Environmental Contamination and Toxicology 1999;37(3):283-289. R825433 (Final)
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    Journal Article Hanson JR, Ackerman CE, Scow KM. Biodegradation of methyl tert-butyl ether by a bacterial pure culture. Applied and Environmental Microbiology 1999;65(11):4788-4792. R825433 (Final)
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    Journal Article Hanson JR, Macalady JL, Harris D, Scow KM. Linking toluene degradation with specific microbial populations in soil. Applied and Environmental Microbiology 1999;65(12):5403-5408. R825433 (Final)
    not available
    Journal Article Hantush MM, Marino MA. An analytical model for the assessment of pesticide exposure levels in soils and groundwater. Environmental Modeling and Assessment 1996;1(4):263-276. R825433 (Final)
    not available
    Journal Article Hantush MM, Marino MA. Estimation of spatially variable aquifer hydraulic properties using Kalman filtering. Journal of Hydraulic Engineering 1997;123(11):1027-1035. R825433 (Final)
    not available
    Journal Article Hantush MM, Marino MA. Stochastic solution to inverse problem in ground water. Journal of Hydraulic Engineering 1997;123(12):1139-1146. R825433 (Final)
    not available
    Journal Article Hantush MM, Marino MA. Interlayer diffusive transfer and transport of contaminants in stratified formation. I: theory. Journal of Hydrologic Engineering 1998;3(4):232-240. R825433 (Final)
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    Journal Article Hantush MM, Marino MA. Interlayer diffusive transfer and transport of contaminants in stratified formation. II: analytical solutions. Journal of Hydrologic Engineering 1998;3(4):241-247. R825433 (Final)
    not available
    Journal Article Hantush MM, Marino MA, Islam MR. Models for leaching of pesticides in soils and groundwater. Journal of Hydrology 2000;227(1-4):66-83. R825433 (Final)
    not available
    Journal Article Hantush MM, Govindaraju RS, Marino MA, Zhang ZL. Screening model for volatile pollutants in dual porosity soils. Journal of Hydrology 2002;260(1-4):58-74. R825433 (Final)
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    Journal Article Hatch LK, Reuter JE, Goldman CR. Daily phosphorus variation in a mountain stream. Water Resources Research 1999;35(12):3783-3791. R825433 (Final)
    R826282 (1999)
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    Journal Article Hatch LK, Reuter JE, Goldman CR. Relative importance of stream-borne particulate and dissolved phosphorus fractions to Lake Tahoe phytoplankton. Canadian Journal of Fisheries and Aquatic Sciences 1999;56(12):2331-2339. R825433 (Final)
    R826282 (1999)
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    Journal Article Hatch L, Reuter JE, Goldman CR. Stream phosphorus transport in the Lake Tahoe Basin, 1989-1996. Environmental Monitoring and Assessment 2001;69(1):63-83. R825433 (Final)
    R826282 (2000)
    R826282 (Final)
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    Journal Article Hedriana HL, Munro CJ, Eby-Wilkens EM, Lasley BL. Changes in rates of salivary estriol increases before parturition at term. American Journal of Obstetrics and Gynecology 2001;184(2):123-130 R825433 (Final)
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    Journal Article Hengel MJ, Mourer CR, Shibamoto T. New method for analysis of pyrethroid insecticides: esfenvalerate, cis-permethrin, and trans-permethrin, in surface waters using solid-phase extraction and gas chromatography. Bulletin of Environmental Contamination and Toxicology 1997;59(2):171-178. R825433 (Final)
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    Journal Article Hengel MJ, Mourer CR, Shibamoto T. Gas chromatographic/mass spectrometric method for analysis of chlorophenoxy acid herbicides: MCPB and MCPA in peas. Journal of Environmental Chemistry 1998;8(3):429-433. R825433 (Final)
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    Journal Article Heyvaert AC, Reuter JE, Slotton DG, Goldman CR. Paleolimnological reconstruction of historical atmospheric lead and mercury deposition at Lake Tahoe, California-Nevada. Environmental Science and Technology 2000;34(17):3588-3597. R825433 (Final)
    R826282 (1999)
    R826282 (2000)
    R826282 (Final)
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    Journal Article Higashi RM, Fan TWM, Lane AN. Association of desferrioxamine with humic substances and their interaction with cadmium(II) as studied by pyrolysis gas chromatography mass spectrometry and nuclear magnetic resonance spectroscopy. Analyst 1998;123(5):911-918. R825433C007 (Final)
    R825960 (1999)
    R825960 (Final)
    not available
    Journal Article Teh SJ, Hinton DE. Gender-specific growth and hepatic neoplasia in medaka (Oryzias latipes). Aquatic Toxicology 1998;41(1-2):141-159 R825433 (Final)
    R825298 (Final)
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    Journal Article Horne FE, Kavvas ML. Physics of the spatially averaged snowmelt process. Journal of Hydrology 1997;191(1):179-207. R825433 (Final)
    not available
    Journal Article Houck A, Cech JJ. Effects of dietary methylmercury on juvenile Sacramento blackfish bioenergetics. Aquatic Toxicology 2004;69(2):107-123. R825433 (Final)
    not available
    Journal Article Hristova KR, Lutenegger CM, Scow KM. Detection and quantification of methyl tert-butyl ether-degrading strain PM1 by real-time TaqMan PCR. Applied and Environmental Microbiology 2001;67(11):5154-5160 R825433 (Final)
    not available
    Journal Article Huang TL, Shiotsuki T, Uematsu T, Borhan B, Li QX, Hammock BD. Structure-activity relationships for substrates and inhibitors of mammalian liver microsomal carboxylesterases. Pharmaceutical Research 1996;13(10):1495-1500 R825433 (Final)
    not available
    Journal Article Jackson LE, Calderon FJ, Steenwerth KL, Scow KM, Rolston DE. Responses of soil microbial processes and community structure to tillage events and implications for soil quality. Geoderma 2003;114(3-4):305-317. R825433 (Final)
    not available
    Journal Article Jacquemoud S, Ustin SL, Verdebout J, Schmuck G, Andreoli G, Hosgood B. Estimating leaf biochemistry using the PROSPECT leaf optical properties model. Remote Sensing of Environment 1996;56(3):194-202. R825433 (Final)
    not available
    Journal Article Jaeger LL, Jones AD, Hammock BD. Development of an enzyme-linked immunosorbent assay for atrazine mercapturic acid in human urine. Chemical Research in Toxicology 1998;11(4):342-352. R825433 (Final)
    not available
    Journal Article Jarvis DL, Reilly LM, Hoover K, Schultz C, Hammock BD, Guarino LA. Construction and characterization of immediate early Baculovirus pesticides. Biological Control 1996;7(2):228-235. R825433 (Final)
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    Journal Article Jassby AD, Cole BE, Cloern JE. The design of sampling transects for characterizing water quality in estuaries. Estuarine, Coastal and Shelf Science 1997;45(3):285-302. R825433 (Final)
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    Journal Article Jassby AD. Interannual variability at three inland water sites: implications for sentinel ecosystems. Ecological Applications 1998;8(2):227-287. R825433 (Final)
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    Journal Article Jassby AD, Goldman CR, Reuter JE, Richards RC. Origins and scale dependence of temporal variability in the transparency of Lake Tahoe, California-Nevada. Limnology and Oceanography 1999;44(2):282-294. R825433 (Final)
    R826282 (1998)
    R826282 (1999)
    R826282 (2000)
    R826282 (Final)
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    Journal Article Jassby AD, Cloern JE, Cole BE. Annual primary production: patterns and mechanisms of change in a nutrient-rich tidal ecosystem. Limnology and Oceanography 2002;47(3):698-712. R825433 (Final)
    not available
    Journal Article Jassby AD, Cloern JE, Muller-Solger AB. Phytoplankton fuels Delta food web. California Agriculture 2003;57(4):104-109. R825433 (Final)
    not available
    Journal Article Jassby AD, Goldman CR, Reuter JE, Richards RC. Biostatistical evaluation of long-term lake clarity record. Verhundlungen der Internationale Vereinigung Limnologie, Volume 27. R825433 (Final)
    R826282 (1999)
    R826282 (2000)
    R826282 (Final)
    not available
    Journal Article Jones G, Wortberg M, Hammock BD, Rocke DM. A procedure for the immunoanalysis of samples containing one or more members of a group of cross-reacting analytes. Analytica Chimica Acta 1996;336(1-3):175-183. R825433 (Final)
    not available
    Journal Article Jones G, Wortberg M, Kreissig SB, Hammock BD, Rocke DM. Application of the bootstrap to calibration experiments. Analytical Chemistry 1996;68(5):763-770. R825433 (Final)
    not available
    Journal Article Kavvas ML, Chen ZQ, Govindaraju RS, Rolston DE, Koos T, Karakas A, Or D, Jones S, Biggar J. Probability distribution of solute travel time for convective transport in field-scale soils under unsteady and nonuniform flows. Water Resources Research 1996;32(4):875-889. R825433 (Final)
    not available
    Journal Article Kavvas ML, Chen ZQ, Tan L, Soong ST, Terakawa A, Yoshitani J, Fukami K. A regional-scale land surface parameterization based on areally-averaged hydrological conservation equations. Hydrological Sciences Journal 1998;43(4):611-631. R825433 (Final)
    R826282 (1998)
    R826282 (2000)
    R826282 (Final)
    not available
    Journal Article Kavvas ML. Nonlinear hydrologic processes: conservation equations for determining their means and probability distributions. Journal of Hydrologic Engineering 2003;8(2):44-53. R825433 (Final)
    not available
    Journal Article Kido H, Goodrow MH, Griffeth V, Lucas AD, Gee SJ, Hammock BD. Development of an enzyme-linked immunosorbent assay for the detection of hydroxytriazines. Journal of Agricultural and Food Chemistry 1997;45(2):414-424. R825433 (Final)
    not available
    Journal Article Kido H, Maquieira A, Hammock BD. Disc-based immunoassay microarrays. Analytica Chimica Acta 2000;411(1-2):1-11. R825433 (Final)
    not available
    Journal Article Kim JG, Rejmankova E. The paleoecological record of human disturbance in wetlands of the Lake Tahoe Basin. Journal of Paleolimnology 2001;25(4):437-454. R825433 (Final)
    not available
    Journal Article Kiribuchi K, Dunlap DY, Matsumura F, Yamaguchi I. Protein kinase C as a biomarker for assessing the effect of environmental stress and fungal invasion on plant defense mechanism. Journal of Pesticide Science 1998;23(2):123-128. R825433 (Final)
    not available
    Journal Article Kirkpatrick JF, McCarthy JC, Gudermuth DF, Shideler SE, Lasley BL. An assessment of the reproductive biology of Yellowstone bison (Bison bison) subpopulations using noncapture methods. Canadian Journal of Zoology 1996;74(1):8-14. R825433 (Final)
    not available
    Journal Article Koger CS, Teh SJ, Hinton DE. Variations of light and temperature regimes and resulting effects on reproductive parameters in medaka (Oryzias latipes). Biology of Reproduction 1999;61(5):1287-1293. R825433 (Final)
    R825298 (Final)
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    Journal Article Koger CS, Teh SJ, Hinton DE. Determining the sensitive developmental stages of intersex induction in medaka (Oryzias latipes) exposed to 17 beta-estradiol or testosterone. Marine Environmental Research 2000;50(1-5):201-206. R825433 (Final)
    R825298 (Final)
    not available
    Journal Article LaBolle EM, Fogg GE, Tompson AFB. Random-walk simulation of transport in heterogeneous porous media: local mass-conservation problem and implementation methods. Water Resources Research 1996;32(3):583-593. R825433 (Final)
    not available
    Journal Article LaBolle EM, Quastel J, Fogg GE. Diffusion theory for transport in porous media: Transition-probability densities of diffusion processes corresponding to advection-dispersion equations. Water Resources Research 1998;34(7):1685-1693 R825433 (Final)
    not available
    Journal Article LaBolle EM, Quastel J, Fogg GE, Gravner J. Diffusion processes in composite porous media and their numerical integration by random walks: generalized stochastic differential equations with discontinuous coefficients. Water Resources Research 2000;36(3):651-662. R825433 (Final)
    not available
    Journal Article LaBolle EM, Fogg GE. Role of molecular diffusion in contaminant migration and recovery in an alluvial aquifer system. Transport in Porous Media 2001;42(1-2):155-179. R825433 (Final)
    not available
    Journal Article Lee J, Tell L, Lasley B. A comparison of sex steroid hormone excretion and metabolism by psittacine species. Zoo Biology 1999;18(4):247-260 R825433 (Final)
    not available
    Journal Article Li HX, Nakajima ST, Chen JG, Todd HE, Overstreet JW, Lasley BL. Differences in hormonal characteristics of conceptive versus nonconceptive menstrual cycles. Fertility and Sterility 2001;75(3):549-553 R825433 (Final)
    not available
    Journal Article Linde CD, Gee SJ, Goh KS, Hsu JC, Hammock BD, Barry TA, Weaver DJ. Regulatory application of ELISA: Compliance monitoring or bromacil in soil. Bulletin of Environmental Contamination and Toxicology 1996;57(2):264-269 R825433 (Final)
    not available
    Journal Article Liu M, Carroll JJ. A high-resolution air pollution model suitable for dispersion studies in complex terrain. Monthly Weather Review 1996;124(10):2396-2409. R825433 (Final)
    not available
    Journal Article Lohse C, Jaeger LL, Staimer N, Sanborn JR, Jones AD, Lango J, Gee SJ, Hammock BD. Development of a class selective enzyme-linked immunosorbent assay for mercapturic acids in human urine. Journal of Agricultural and Food Chemistry 2000;48(12):5913-5923 R825433 (Final)
    not available
    Journal Article Macalady JL, Fuller ME, Scow KM. Effects of metam sodium fumigation on soil microbial activity and community structure. Journal of Environmental Quality 1998;27(1):54-63. R825433 (Final)
    not available
    Journal Article Macalady JL, Mack EE, Nelson DC, Scow KM. Sediment microbial community structure and mercury methylation in mercury-polluted Clear Lake, California. Applied and Environmental Microbiology 2000;66(4):1479-1488. R825433 (Final)
    not available
    Journal Article Mackay CE, Hammock BD, Wilson BW. Identification and isolation of a 155-kDa protein with neuropathy target esterase activity. Fundamental and Applied Toxicology 1996;30(1):23-30. R825433 (Final)
    not available
    Journal Article Matveeva EG, Shan G, Kennedy IM, Gee SJ, Stoutamire DW, Hammock BD. Homogeneous fluoroimmunoassay of a pyrethroid metabolite in urine. Analytica Chimica Acta 2001;444(1):103-117. R825433 (Final)
    not available
    Journal Article McCutchen BF, Hoover K, Preisler HK, Betana MD, Herrmann R, Robertson JL, Hammock BD. Interactions of recombinant and wild-type baculoviruses with classical insecticides and pyrethroid-resistant tobacco budworm (Lepidoptera:Noctuidae). Journal of Economic Entomology 1997;90(5):1170-1180. R825433 (Final)
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    Journal Article McGregor KG, Anastasio C. Chemistry of fog water in California's Central Valley: 2. Photochemical transformations of amino acids and alkyl amines. Atmospheric Environment 2001;35(6):1091-1104. R825433 (Final)
    not available
    Journal Article Meillier LM, Suchanek TH, Richerson PJ, Nelson DC, Heyvaert A, Slotton DG, McHatton SC. Pre-historic and historic mercury in Clear Lake, California as deduced from lake sediment cores. The Science of the Total Environment. R825433 (Final)
    not available
    Journal Article Midgley R, England B, Gonsalez K, Davis M, Possley R, Kitzsteiner S, Skurnick J, Crawford S, Santoro N, Lasley BL, McConnell D. Insuring reliability of assay results in a large, longitudinal, multicenter, cooperative study of the menopausal transition. Clinical Chemistry. R825433 (Final)
    not available
    Journal Article Miyake T, Shibamoto T. Formation of formaldehyde from methyl tert-butyl ether (MTBE) upon UV irradiation. Bulletin of Environmental Contamination and Toxicology 1999;62(4):416-419. R825433 (Final)
    not available
    Journal Article Moghaddam MF, Motoba K, Borhan B, Pinot F, Hammock BD. Novel metabolic pathways for linoleic acid and arachidonic acid metabolism. Biochimica et Biophysica Acta 1996;1290(3):327-339. R825433 (Final)
    not available
    Journal Article Moghaddam MF, Grant DF, Cheek JM, Greene JF, Williamson KC, Hammock BD. Bioactivation of leukotoxins to their toxic diols by epoxide hydrolase. Nature Medicine 1997;3(5):562-566. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Yamaguchi T, Schjonning P, Rolston DE. Modeling diffusion and reaction in soils: IX. The Buckingham-Burdine-Campbell equation for gas diffusivity in undisturbed soil. Soil Science 1999;164(8):542-551. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Yamaguchi T, Schjonning P, Rolston DE. Modeling diffusion and reaction in soils: VIII. Gas diffusion predicted from single-potential diffusivity or permeabilty measurements. Soil Science 1999;164(2):75-81. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Gamst J, Schjonning P, Yamaguchi T, Rolston DE. Predicting the gas diffusion coefficient in repacked soil: water-induced linear reduction model. Soil Science Society of America Journal 2000;64(5):1588-1594. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Schjonning P, Yamaguchi T, Rolston DE. Predicting the gas diffusion coefficient in undisturbed soil from soil water characteristics. Soil Science Society of America Journal 2000;64(1):94-100. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Komatsu T, Schjonning P, Rolston DE. Tortuosity, diffusivity, and permeability in the soil liquid and gaseous phases. Soil Science Society of America Journal 2001;65(3):613-623. R825433 (Final)
    not available
    Journal Article Moldrup P, Yoshikawa S, Olesen T, Komatsu T, Rolston DE. Air permeability in undisturbed volcanic ash soils: predictive model test and soil structure fingerprint. Soil Science Society of America Journal 2003;67(1):32-40. R825433 (Final)
    not available
    Journal Article Moldrup P, Yoshikawa S, Olesen T, Komatsu T, Rolston DE. Gas diffusivity in undisturbed volcanic ash soils: test of soil-water-characteristic-based prediction models. Soil Science Society of America Journal 2003;67(1):41-51. R825433 (Final)
    not available
    Journal Article Moldrup P, Olesen T, Komatsu T, Yoshikawa S, Schjonning P, Rolston DE. Modeling diffusion and reaction in soils: X. A unifying model for solute and gas diffusivity in unsaturated soil. Soil Science 2003;168(5):321-337. R825433 (Final)
    not available
    Journal Article Morisseau C, Du GH, Newman JW, Hammock BD. Mechanism of mammalian soluble epoxide hydrolase inhibition by chalcone oxide derivatives. Archives of Biochemistry and Biophysics 1998;356(2):214-228. R825433 (Final)
    not available
    Journal Article Morisseau C, Ward BL, Gilchrist DG, Hammock BD. Multiple epoxide hydrolases in Alternaria alternata f. sp lycopersici and their relationship to medium composition and host-specific toxin production. Applied and Environmental Microbiology 1999;65(6):2388-2395 R825433 (Final)
    not available
    Journal Article Morisseau C, Goodrow MH, Dowdy D, Zheng J, Greene JF, Sanborn JR, Hammock BD. Potent urea and carbamate inhibitors of soluble epoxide hydrolases. Proceedings of the National Academy of Sciences of the United States of America 1999;96(16):8849-8854. R825433 (Final)
    not available
    Journal Article Morisseau C, Beetham JK, Pinot F, Debernard S, Newman JW, Hammock BD. Cress and potato soluble epoxide hydrolases: purification, biochemical characterization, and comparison to mammalian enzymes. Archives of Biochemistry and Biophysics 2000;378(2):321-332. R825433 (Final)
    not available
    Journal Article Morisseau C, Newman JW, Dowdy DL, Goodrow MH, Hammock BD. Inhibition of microsomal epoxide hydrolases by ureas, amides, and amines. Chemical Research in Toxicology 2001;14(4):409-415. R825433 (Final)
    not available
    Journal Article Moskowitz H, Herrmann R, Jones AD, Hammock BD. A depressant insect-selective toxin analog from the venom of the scorpion Leiurus quinquestriatus hebraeus - Purification and structure/function characterization. European Journal of Biochemistry 1998;254(1):44-49 R825433 (Final)
    not available
    Journal Article Muller F, Arand M, Frank H, Seidel A, Hinz W, Winkler L, Hanel K, Blee E, Beetham JK, Hammock BD, Oesch F. Visualization of a covalent intermediate between microsomal epoxide hydrolase, but not cholesterol epoxide hydrolase, and their substrates. European Journal of Biochemistry 1997;245(2):490-496. R825433 (Final)
    not available
    Journal Article Nakagawa Y, Wheelock CE, Morisseau C, Goodrow MH, Hammock BG, Hammock BD. 3-D QSAR analysis of inhibition of murine soluble epoxide hydrolase (MsEH) by benzoylureas, arylureas, and their analogues. Bioorganic & Medicinal Chemistry 2000;8(11):2663-2673. R825433 (Final)
    not available
    Journal Article Nakatsugawa M, Anderson M, Kavvas ML. A simplified climate model with combined atmospheric-hydrological processes. Hydrological Sciences Journal 1996;41(6):915-938. R825433 (Final)
    not available
    Journal Article Nisbet ICT, Fry DM, Hatch JJ, Lynn B. Feminization of male common tern embryos is not correlated with exposure to specific PCB congeners. Bulletin of Environmental Contamination and Toxicology 1996;57(6):895-901. R825433 (Final)
    not available
    Journal Article Olesen T, Moldrup P, Yamaguchi T, Nissen HH, Rolston DE. Modified half-cell method for measuring the solute diffusion coefficients in undisturbed, unsaturated soil. Soil Science 2000;165(11):835-840. R825433 (Final)
    not available
    Journal Article Olesen T, Moldrup P, Yamaguchi T, Rolston DE. Constant slope impedance factor model for predicting the solute diffusion coefficient in unsaturated soil. Soil Science 2001;166(2):89-96. R825433 (Final)
    not available
    Journal Article Olesen T, Gamst J, Moldrup P, Komatsu T, Rolston DE. Diffusion of sorbing organic chemicals in the liquid and gaseous phases of repacked soil. Soil Science Society of America Journal 2001;65(6):1585-1593. R825433 (Final)
    not available
    Journal Article Parker AG, Pinot F, Grant DF, Spearow J, Hammock BD. Regulation of mouse liver microsomal esterases by clofibrate and sexual hormones. Biochemical Pharmacology 1996;51(5):677-685. R825433 (Final)
    not available
    Journal Article Pedersen T, Shibamoto T. Analysis of the naturally occurring pesticide rotenone by capillary gas chromatography. Journal of High Resolution Chromatography 1999;22(5):294-296. R825433 (Final)
    not available
    Journal Article Petersen LW, El-Farhan YH, Moldrup P, Rolston DE, Yamaguchi T. Transient diffusion, adsorption, and emission of volatile organic vapors in soils with fluctuating low water contents. Journal of Environmental Quality 1996;25(5):1054-1063. R825433 (Final)
    not available
    Journal Article Pinot F, Caldas ED, Schmidt C, Gilchrist DG, Jones AD, Winter CK, Hammock BD. Characterization of epoxide hydrolase activity in Alternaria alternata f. sp. lycopersici. Possible involvement in toxin production - Epoxide hydrolase in Alternaria alternata f. sp. lycopersici. Mycopathologia 1997;140(1):51-58. R825433 (Final)
    not available
    Journal Article Pinot F, Bosch H, Salaun JP, Durst F, Mioskowski C, Hammock BD. Epoxide hydrolase activities in the microsomes and the soluble fraction from Vicia sativa seedlings. Plant Physiology and Biochemistry 1997;35(2):103-110. R825433 (Final)
    not available
    Journal Article Poudel DD, Ferris H, Klonsky K, Horwath WR, Scow KM, van Bruggen AHC, Lanini WT, Mitchell JP, Temple SR. The sustainable agriculture farming system project in California's Sacramento Valley. Outlook on Agriculture 2001;30(2):109-116. R825433 (Final)
    not available
    Journal Article Reichman R, Rolston DE. Design and performance of a dynamic gas flux chamber. Journal of Environmental Quality 2002;31(6):1774-1781. R825433 (Final)
    not available
    Journal Article Reimer GJ, Gee SJ, Hammock BD. Comparison of a time-resolved fluorescence immunoassay and an enzyme-linked immunosorbent assay for the analysis of atrazine in water. Journal of Agricultural and Food Chemistry 1998;46(8):3353-3358. R825433 (Final)
    not available
    Journal Article Rejmankova E, Rejmanek M, Djohan T, Goldman CR. Resistance and resilience of subalpine wetlands with respect to prolonged drought. Folia Geobotanica 1999;34(2):175-188. R825433 (Final)
    not available
    Journal Article Reuter JE, Allen BC, Richards RC, Pankow JF, Goldman CR, Scholl RL, Seyfried JS. Concentrations, sources, and fate of the gasoline oxygenate methyl tert-butyl ether (MTBE) in a multiple-use lake. Environmental Science and Technology 1998;32(23):3666-3672. R825433 (Final)
    R826282 (1998)
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    Journal Article Ringwood AH, Hameedi MJ, Lee RF, Brouwer M, Peters EC, Scott GI, Luoma SN, Digiulio RT. Bivalve Biomarker Workshop: overview and discussion group summaries. Biomarkers 1999;4(6):391-399. R825433 (Final)
    not available
    Journal Article Rueda FJ, Schladow SG, Palmarsson SO. Basin-scale internal wave dynamics during a winter cooling period in a large lake. Journal of Geophysical Research 2003;108(C3):3097. R825433 (Final)
    R826282 (Final)
    not available
    Journal Article Rueda FJ, Schladow SG. Dynamics of large polymictic lake. II: Numerical simulations. Journal of Hydraulic Engineering 2003;129(2):92-101 R825433 (Final)
    R825428 (Final)
    R826282 (Final)
    not available
    Journal Article Salardino DH, Carroll JJ. Correlation between ozone exposure and visible foliar injury in ponderosa and Jeffrey pines. Atmospheric Environment 1998;32(17):3001-3010. R825433 (Final)
    not available
    Journal Article Sanborn JR, Gee SJ, Gilman SD, Sugawara Y, Jones AD, Rogers J, Szurdoki F, Stanker LH, Stoutamire DW, Hammock BD. Hapten synthesis and antibody development for polychlorinated dibenzo-p-dioxin immunoassays. Journal of Agricultural and Food Chemistry 1998;46(6):2407-2416. R825433 (Final)
    not available
    Journal Article Sanderson EW, Zhang M, Ustin SL, Rejmankova E. Geostatistical scaling of canopy water content in a California salt marsh. Landscape Ecology 1998;13(2):79-92. R825433 (Final)
    not available
    Journal Article Schutz S, Wengatz I, Goodrow MH, Gee SJ, Hummel HE, Hammock BD. Development of an enzyme-linked immunosorbent assay for azadirachtins. Journal of Agricultural and Food Chemistry 1997;45(6):2363-2368 R825433 (Final)
    not available
    Journal Article Schwartz E, Trinh SV, Scow KM. Measuring growth of a phenanthrene-degrading bacterial inoculum in soil with a quantitative competitive polymerase chain reaction method. Fems Microbiology Ecology 2000;34(1):1-7 R825433 (Final)
    not available
    Journal Article Schwartz E, Scow KM. Repeated inoculation as a strategy for the remediation of low concentrations of phenanthrene in soil. Biodegradation 2001;12(3):201-207. R825433 (Final)
    not available
    Journal Article Seifert J, Wilson BW. Phenyl valerate carboxylesterases of chick embryo brain as a marker for a new microassay of phospholipase A(2). Analytical Letters 1998;31(4):601-611. R825433 (Final)
    not available
    Journal Article Shan GM, Wengatz I, Stoutamire DW, Gee SJ, Hammock BD. An enzyme-linked immunosorbent assay for the detection of esfenvalerate metabolites in human urine. Chemical Research in Toxicology 1999;12(11):1033-1041. R825433 (Final)
    not available
    Journal Article Shan GM, Stoutamire DW, Wengatz I, Gee SJ, Hammock BD. Development of an immunoassay for the pyrethroid insecticide esfenvalerate. Journal of Agricultural and Food Chemistry 1999;47(5):2145-2155. R825433 (Final)
    not available
    Journal Article Shan GM, Leeman WR, Stoutamire DW, Gee SJ, Chang DPY, Hammock BD. Enzyme-linked immunosorbent assay for the pyrethroid permethrin. Journal of Agricultural and Food Chemistry 2000;48(9):4032-4040. R825433 (Final)
    not available
    Journal Article Shan G, Leeman WR, Gee SJ, Sanborn JR, Jones AD, Chang DPY, Hammock BD. Highly sensitive dioxin immunoassay and its applications to soil and biota samples. Analytica Chimica Acta 2001;444(1):169-178. R825433 (Final)
    not available
    Journal Article Soimasuo MR, Werner I, Villalobos A, Hinton DE. Cytochrome P450 1A-and stress protein-induction in early life stages of medaka (Oryzias latipes) exposed to trichloroethylene (TCE) soot and different fractions. Biomarkers 2001;6(2):133-145 R825433 (Final)
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    Journal Article Southworth J, Randolph JC, Doering OC, Habeck M, Rao G, Pfeifer RA. Implications of changes in midwestern soybean yields as a result of future changes in climate, climate variability, and CO2 fertilization. Climatic Change. R825433 (Final)
    not available
    Journal Article Spanglet HJ, Ustin SL, Rejmankova E. Spectral reflectance characteristics of California subalpine marsh plant communities. Wetlands 1998;18(3):307-319. R825433 (Final)
    not available
    Journal Article Staimer N, Gee SJ, Hammock BD. Development of a class-selective enzyme immunoassay for urinary phenolic glucuronides. Analytica Chimica Acta 2001;444(1):27-36. R825433 (Final)
    not available
    Journal Article Staimer N, Gee SJ, Hammock BD. Development of a sensitive enzyme immunoassay for the detection of phenyl-beta-D-thioglucuronide in human urine. Fresenius' Journal of Analytical Chemistry 2001;369(3-4):273-279. R825433 (Final)
    not available
    Journal Article Stanton B, Watkins S, German JB, Lasley B. Interaction of estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with hepatic fatty acid synthesis and metabolism of male chickens (Gallus domesticus). Comparative Biochemistry and Physiology C-Toxicology & Pharmacology 2001;129(2):137-150 R825433 (Final)
    R826298 (2000)
    R826298 (Final)
    not available
    Journal Article Stauffer C, Shiotsuki T, Chan W, Hammock BD. Characterization of the esterase isozymes of Ips typographus (Coleoptera, Scolytidae). Archives of Insect Biochemistry and Physiology 1997;34(2):203-221. R825433 (Final)
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    Journal Article Stein RW, Yamamoto JT, Fry DM, Wilson BW. Comparative hematology and plasma biochemistry of Red-tailed Hawks and American Kestrels wintering in California. Journal of Raptor Research 1998;32(2):163-169 R825433 (Final)
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    Journal Article Stoops MA, Anderson GB, Lasley BL, Shideler SE. Use of fecal steroid metabolites to estimate the pregnancy rate of a free-ranging herd of tule elk. Journal of Wildlife Management 1999;63(2):561-569. R825433 (Final)
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    Journal Article Suchanek TH, Mullen LH, Lamphere BA, Richerson PJ, Woodmansee CE, Slotton DG, Harner EJ, Woodward LA. Redistribution of mercury from contaminated lake sediments of Clear Lake, California. Water, Air and Soil Pollution 1998;104(1-2):77-102. R825433 (Final)
    R825285 (Final)
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    Journal Article Suchanek TH, Richerson PJ, Flanders JR, Nelson DC, Mullen LH, Brister LL, Becker JC. Monitoring inter-annual variability reveals sources of mercury contamination in Clear Lake, California. Environmental Monitoring and Assessment 2000;64(1):299-310. R825433 (Final)
    R825285 (Final)
    not available
    Journal Article Sugawara Y, Gee SJ, Sanborn JR, Gilman SD, Hammock BD. Development of a highly sensitive enzyme-linked immunosorbent assay based on polyclonal antibodies for the detection of polychlorinated dibenzo-p-dioxins. Analytical Chemistry 1998;70(6):1092-1099. R825433 (Final)
    not available
    Journal Article Sugawara Y, Saito K, Ogawa M, Kobayashi S, Shan GM, Sanborn JR, Hammock BD, Nakazawa H, Matsuki Y. Development of dioxin toxicity evaluation method in human milk by enzyme-linked immunosorbent assay-assay validation for human milk. Chemosphere 46(9-10):1471-1476. R825433 (Final)
    not available
    Journal Article Szurdoki F, Jaeger L, Harris A, Kido H, Wengatz I, Goodrow MH, Szekacs A, Wortberg M, Zheng J, Stoutamire DW, Sanborn JR, Gilman SD, Jones AD, Gee SJ, Choudary PV, Hammock BD. Rapid assays for environmental and biological monitoring. Journal of Environmental Science and Health Part B-Pesticides, Food Contaminants, and Agricultural Wastes 1996;31(3):451-458. R825433 (Final)
    not available
    Journal Article Szurdoki F, Trousdale E, Ward B, Gee SJ, Hammock BD, Gilchrist DG. Synthesis of protein conjugates and development of immunoassays for AAL toxins. Journal of Agricultural and Food Chemistry 1996;44(7):1796-1803. R825433 (Final)
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    Journal Article Taniai K, Inceoglu AB, Hammock BD. Expression efficiency of a scorpion neurotoxin, AaHIT, using baculovirus in insect cells. Applied Entomology and Zoology 2002;37(2):225-232. R825433 (Final)
    not available
    Journal Article Tayfur G, Kavvas ML. Areally-averaged overland flow equations at hillslope scale. Hydrological Sciences Journal 1998;43(3):361-378. R825433 (Final)
    R826282 (1998)
    R826282 (Final)
    not available
    Journal Article Teh SJ, Adams SM, Hinton DE. Histopathologic biomarkers in feral freshwater fish populations exposed to different types of contaminant stress. Aquatic Toxicology 1997;37(1):51-70. R825433 (Final)
    not available
    Journal Article Teh SJ, Clark SL, Brown CL, Luoma SN, Hinton DE. Enzymatic and histopathologic biomarkers as indicators of contaminant exposure and effect in Asian clam (Potamocorbula amurensis). Biomarkers 1999;4(6):497-509. R825433 (Final)
    not available
    Journal Article Teh SJ, Werner I, Hinton DE. Sublethal effects of chromium-VI in the Asian clam (Potamocorbula amurensis). Marine Environmental Research 2000;50(1-5):295-300. R825433 (Final)
    not available
    Journal Article Tell L, Shukla A, Munson L, Thosar S, Kass P, Stanton R, Needham M, Lasley B. A comparison of the effects of slow release, injectable levonorgestrel and depot medroxyprogesterone acetate on egg production in Japanese quail (Coturnix coturnix japonica). Journal of Avian Medicine and Surgery 1999;13(1):23-31 R825433 (Final)
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    Journal Article Thomas BA, Church WB, Lane TR, Hammock BD. Homology model of juvenile hormone esterase from the crop pest, Heliothis virescens. Proteins: Structure, Function, and Genetics 1999;34(2):184-196. R825433 (Final)
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    Journal Article Thomas BA, Hinton AC, Moskowitz H, Severson TF, Hammock BD. Isolation of juvenile hormones esterase and its partial cDNA clone from the beetle, Tenebrio molitor. Insect Biochemistry and Molecular Biology 2000;30(7):529-540. R825433 (Final)
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    Journal Article Umano K, Reece CA, Shibamoto T. Recovery of trace organic chemicals from a large mass of water using a newly developed liquid-liquid continuous extractor. Bulletin of Environmental Contaminant and Toxicology 1996;56(4):558-565. R825433 (Final)
    not available
    Journal Article Venterea RT, Rolston DE. Mechanistic modeling of nitrite accumulation and nitrogen oxide gas emissions during nitrification. Journal of Environmental Quality 2000;29(6):1741-1751. R825433 (Final)
    not available
    Journal Article Venterea RT, Rolston DE. Nitric and nitrous oxide emissions following fertilizer application to agricultural soil: biotic and abiotic mechanisms and kinetics. Journal of Geophysical Research Atmospheres 2000;105(D12):15117-15129. R825433 (Final)
    not available
    Journal Article Venterea RT, Rolston DE. Nitrogen oxide trace gas transport and transformation: 1. Evaluation of data from intact soil cores. Soil Science 2002;167(1):35-48 R825433 (Final)
    not available
    Journal Article Venterea RT, Rolston DE. Nitrogen oxide trace gas transport and transformation: II. Model simulations compared with data. Soil Science 2002;167(1):49-61. R825433 (Final)
    not available
    Journal Article Villalobos SA, Anderson MJ, Denison MS, Hinton DE, Tullis K, Kennedy IM, Jones AD, Chang DPY, Yang GS, Kelly P. Dioxinlike properties of a trichloroethylene combustion-generated aerosol. Environmental Health Perspectives 1996;104(7):734-743. R825433 (Final)
    not available
    Journal Article Villalobos SA, Hamm JT, Teh SJ, Hinton DE. Thiobencarb-induced embryotoxicity in medaka (Oryzias latipes): stage-specific toxicity and the protective role of chorion. Aquatic Toxicology 2000;48(2-3):309-326. R825433 (Final)
    not available
    Journal Article Washburn BS, Vines CA, Baden DG, Hinton DE, Walsh PJ. Differential effects of brevetoxin and beta-naphthoflavone on xenobiotic metabolizing enzymes in striped bass (Morone saxatilis). Aquatic Toxicology 1996;35(1):1-10 R825433 (Final)
    not available
    Journal Article Watanabe T, Shan G, Stoutamire DW, Gee SJ, Hammock BD. Development of a class-specific immunoassay for the type I pyrethroid insecticides. Analytica Chimica Acta 2001;444(1):119-129. R825433 (Final)
    not available
    Journal Article Weissmann GS, Carle SF, Fogg GE. Three-dimensional hydrofacies modeling based on soil surveys and transition probability geostatistics. Water Resources Research 1999;35(6):1761-1770. R825433 (Final)
    not available
    Journal Article Weissmann GS, Zhang Y, LaBolle EM, Fogg GE. Dispersion of groundwater age in an alluvial aquifer system. Water Resources Research 2002;38(10), Art. No. 1198, doi 10.1029/2001WR000907. R825433 (Final)
    not available
    Journal Article Wengatz I, Stoutamire DW, Gee SJ, Hammock BD. Development of an enzyme-linked immunosorbent assay for the detection of the pyrethroid insecticide fenpropathrin. Journal of Agricultural and Food Chemistry 1998;46(6):2211-2221. R825433 (Final)
    not available
    Journal Article Werner I, Hinton DE. Field validation of hsp70 stress proteins as biomarkers in Asian clam (Potamocorbula amurensis): is downregulation an indicator of stress? Biomarkers 1999;4(6):473-484. R825433 (Final)
    R823297 (1997)
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  • Journal Article Werner I, Hinton DE. Spatial profiles of hsp70 proteins in Asian clam (Potamocorbula amurensis) in northern San Francisco Bay may be linked to natural rather than anthropogenic stressors. Marine Environmental Research 2000;50(1-5):379-384. R825433 (Final)
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    Journal Article Werner I, Koger CS, Hamm JT, Hinton DE. Ontogeny of the heat shock protein, hsp70 and hsp60, response and developmental effects of heat-shock in the teleost, medaka (Oryzias latipes). Environmental Sciences 2001;8(1):13-30. R825433 (Final)
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    Journal Article Werner I, Clark SL, Hinton DE. Biomarkers aid understanding of aquatic organism responses to environmental stressors. California Agriculture 2003;57(4):110-115. R825433 (Final)
    R826940 (Final)
    not available
    Journal Article Wilson BW, Padilla S, Henderson JD, Brimijoin S, Dass PD, Elliot G, Jaeger B, Lanz D, Pearson R, Spies R. Factors in standardizing automated cholinesterase assays. Journal of Toxicology and Environmental Health 1996;48(2):187-195. R825433 (Final)
    not available
    Journal Article Wilson BW, Sanborn JR, OMalley MA, Henderson JD, Billitti JR. Monitoring the pesticide-exposed worker. Occupational Medicine: State of the Art Reviews 1997;12(2):347-363. R825433 (Final)
    not available
    Journal Article Wolfe MF, Hinton DE, Seiber JN. Aqueous sample preparation for bioassay using supercritical-fluid extraction. Environmental Toxicology and Chemistry 1995;14(6):1001-1009. R825433 (Final)
    not available
    Journal Article Woodward LA, Mulvey M, Newman MC. Mercury contamination and population-level responses in chironomids: can allozyme polymorphism indicate exposure? Environmental Toxicology and Chemistry 1996;15(8):1309-1316. R825433 (Final)
    not available
    Journal Article Wortberg M, Jones G, Kreissig SB, Rocke DM, Gee SJ, Hammock BD. An approach to the construction of an immunoarray for differentiating and quantitating cross reacting analytes. Analytica Chimica Acta 1996;319(3):291-303. R825433 (Final)
    not available
    Journal Article Wortberg M, Goodrow MH, Gee SJ, Hammock BD. Immunoassay for simazine and atrazine with low cross-reactivity for propazine. Journal of Agricultural and Food Chemistry 1996;44(8):2210-2219. R825433 (Final)
    not available
    Journal Article Wudayagiri R, Inceoglu B, Herrmann R, Derbel M, Choudary PV, Hammock BD. Isolation and characterization of a novel lepidopteran-selective toxin from the venom of South Indian red scorpion, Mesobuthus tamulus. BMC Biochemistry 2001;2():16 R825433 (Final)
    not available
    Journal Article Yamamoto JT, Santolo GM, Wilson BW. Selenium accumulation in captive American kestrels (Falco sparverius) fed selenomethionine and naturally incorporated selenium. Environmental Toxicology and Chemistry 1998;17(12):2494-2497. R825433 (Final)
    not available
    Journal Article Yazynina EV, Zherdev AV, Dzantiev BB, Izumrudov VA, Gee SJ, Hammock BD. Immunoassay techniques for detection of the herbicide simazine based on use of oppositely charged water-soluble polyelectrolytes. Analytical Chemistry 1999;71(16):3538-3543. R825433 (Final)
    not available
    Journal Article Yoon J, Kavvas ML. Probablistic solution to stochastic overland flow equation. Journal of Hydrologic Engineering 2003;8(2):54-63. R825433 (Final)
    not available
    Journal Article Zaremba LL, Carroll JJ. Summer wind flow regimes over the Sacramento Valley. Journal of Applied Meteorology 1999;38(10):1463-1473 R825433 (Final)
    not available
    Journal Article Zhang MH, Geng S, Ustin SL, Tanji KK. Pesticide occurrence in groundwater in Tulare County, California. Environmental Monitoring and Assessment 1997;45(2):101-127. R825433 (Final)
    not available
    Journal Article Zhang MH, Geng S, Ustin SL. Quantifying the agricultural landscape and assessing spatio-temporal patterns of precipitation and groundwater use. Landscape Ecology 1998;13(1):37-53 R825433 (Final)
    not available
    Journal Article Zhang M, Ustin SL, Rejmankova E, Sanderson E. Monitoring Pacific coast salt marshes using remote sensing. Ecological Applications 1997;7(3):1039-1053. R825433 (Final)
    not available
    Journal Article Zhang Q, Anastasio C. Chemistry of fog waters in California's Central Valley - Part 3: concentrations and speciation of organic and inorganic nitrogen. Atmospheric Environment 2001;35(32):5629-5643. R825433 (Final)
    not available
    Journal Article Zhang Q, Carroll JJ, Dixon AJ, Anastasio C. Aircraft measurements of nitrogen and phosphorus in and around the Lake Tahoe Basin: implications for possible sources of atmospheric pollutants to Lake Tahoe. Environmental Science & Technology 2002;36(23):4981-4989. R825433 (Final)
    not available
    Journal Article Zhang Q, Anastasio C, Jimenez-Cruz M. Water-soluble organic nitrogen in atmospheric fine particles (PM2.5) from northern California. Journal of Geophysical Research-Atmospheres 2002;107(D11), Art. No. 4112, doi 10.1029/2001JD000870. R825433 (Final)
    not available
    Journal Article Zhang Q, Anastasio C. Conversion of fogwater and aerosol organic nitrogen to ammonium, nitrate, and NOx during exposure to simulated sunlight and ozone. Environmental Science & Technology 2003;37(16):3522-3530. R825433 (Final)
    not available
    Journal Article Zhang Q, Anastasio C. Free and combined amino compounds in atmospheric fine particles (PM2.5) and fog waters from Northern California. Atmospheric Environment 2003;37(16):2247-2258. R825433 (Final)
    not available
    Journal Article Zheng J, Hammock BD. Development of polyclonal antibodies for detection of protein modification by 1,2-naphthoquinone. Chemical Research in Toxicology 1996;9(5):904-909. R825433 (Final)
    not available
    Journal Article Zheng J, Cho M, Jones AD, Hammock BD. Evidence of quinone metabolites of naphthalene covalently bound to sulfur nucleophiles of proteins of murine Clara cells after exposure to naphthalene. Chemical Research in Toxicology 1997;10(9):1008-1014. R825433 (Final)
    not available
    Journal Article Zheng J, Plopper CG, Lakritz J, Storms DH, Hammock BD. Leukotoxin-diol: a putative toxic mediator involved in acute respiratory distress syndrome. American Journal of Respiratory Cell and Molecular Biology 2001;25(4):434-438. R825433 (Final)
    not available
    Journal Article Fan TWM, Frenkiel A, Lane AN, Higashi RM. Anaerobic nitrate and ammonium metabolism in flood-tolerant rice coleoptiles. Journal of Experimental Botany 1997;48(314):1655-1666. R825433 (Final)
    not available
    Journal Article Gilman SD, Gee SJ, Hammock BD, Vogel JS, Haack K, Buchholz BA, Freeman SPHT, Wester RC, Hui XY, Maibach HI. Analytical performance of accelerator mass spectrometry and liquid scintillation counting for detection of C14-labeled atrazine metabolites in human urine. Analytical Chemistry 1998;70(16):3463-3469. R825433 (Final)
    not available
    Journal Article Macalady JL, McMillan AMS, Dickens AF, Tyler SC, Scow KM. Population dynamics of type I and II methanotrophic bacteria in rice soils. Environmental Microbiology 2002;4(3):148-57. R825433 (Final)
    not available
    Supplemental Keywords:

    ecosystem, ecosystem protection, environmental exposure and risk, geographic area, international cooperation, water, terrestrial ecosystems, aquatic ecosystem, aquatic ecosystem restoration, aquatic ecosystems and estuarine research, biochemistry, ecological effects, ecological indicators, ecological monitoring, ecology and ecosystems, environmental chemistry, restoration, state, water and watershed, watershed, watershed development, watershed land use, watershed management, watershed modeling, watershed restoration, watershed sustainability, agricultural watershed, exploratory research environmental biology, California, CA, Clear Lake, Lake Tahoe, anthropogenic effects, aquatic habitat, biogeochemical cycling, ecological assessment, ecology assessment models, ecosystem monitoring, ecosystem response, ecosystem stress, environmental stress, environmental stress indicators, fish habitat, hydrologic modeling, hydrology, integrated watershed model, lake ecosystems, lakes, land use, nutrient dynamics, nutrient flux, water management options, water quality, wetland. , Ecosystem Protection/Environmental Exposure & Risk, Water, INTERNATIONAL COOPERATION, Geographic Area, Scientific Discipline, RFA, ECOSYSTEMS, Ecosystem/Assessment/Indicators, Water & Watershed, Restoration, Aquatic Ecosystem Restoration, Aquatic Ecosystems & Estuarine Research, Terrestrial Ecosystems, Ecological Monitoring, Aquatic Ecosystem, Biochemistry, Watersheds, Environmental Chemistry, Ecological Effects - Environmental Exposure & Risk, Ecosystem Protection, Ecology and Ecosystems, Environmental Monitoring, State, lakes, water quality, California (CA), wildlife habitat, watershed modeling, watershed land use, watershed, watershed management, watershed restoration, Clear Lake, hydrologic modeling, ecology assessment models, Clear Lake , environmental stress indicators, anthropogenic effects, fish habitat, land use, wetlands, watershed development, Lake Tahoe, aquatic habitat, agricultural watershed, aquatic ecosystems, environmental stress, lake ecosysyems, watershed sustainablility, biogeochemcial cycling, ecological assessment, hydrology, water management options, ecosystem stress, ecosystem response, ecosystem monitoring, nutrient dynamics, integrated watershed model
    Relevant Websites:

    http://ice.ucdavis.edu/cehr/ exit EPA

    Progress and Final Reports:
    Original Abstract

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825433C001 Potential for Long-Term Degradation of Wetland Water Quality Due to Natural Discharge of Polluted Groundwater
    R825433C002 Sacramento River Watershed
    R825433C003 Endocrine Disruption in Fish and Birds
    R825433C004 Biomarkers of Exposure and Deleterious Effect: A Laboratory and Field Investigation
    R825433C005 Fish Developmental Toxicity/Recruitment
    R825433C006 Resolving Multiple Stressors by Biochemical Indicator Patterns and their Linkages to Adverse Effects on Benthic Invertebrate Patterns
    R825433C007 Environmental Chemistry of Bioavailability in Sediments and Water Column
    R825433C008 Reproduction of Birds and mammals in a terrestrial-aquatic interface
    R825433C009 Modeling Ecosystems Under Combined Stress
    R825433C010 Mercury Uptake by Fish
    R825433C011 Clear Lake Watershed
    R825433C012 The Role of Fishes as Transporters of Mercury
    R825433C013 Wetlands Restoration
    R825433C014 Wildlife Bioaccumulation and Effects
    R825433C015 Microbiology of Mercury Methylation in Sediments
    R825433C016 Hg and Fe Biogeochemistry
    R825433C017 Water Motions and Material Transport
    R825433C018 Economic Impacts of Multiple Stresses
    R825433C019 The History of Anthropogenic Effects
    R825433C020 Wetland Restoration
    R825433C021 Sierra Nevada Watershed Project
    R825433C022 Regional Transport of Air Pollutants and Exposure of Sierra Nevada Forests to Ozone
    R825433C023 Biomarkers of Ozone Damage to Sierra Nevada Vegetation
    R825433C024 Effects of Air Pollution on Water Quality: Emission of MTBE and Other Pollutants From Motorized Watercraft
    R825433C025 Regional Movement of Toxics
    R825433C026 Effect of Photochemical Reactions in Fog Drops and Aerosol Particles on the Fate of Atmospheric Chemicals in the Central Valley
    R825433C027 Source Load Modeling for Sediment in Mountainous Watersheds
    R825433C028 Stress of Increased Sediment Loading on Lake and Stream Function
    R825433C029 Watershed Response to Natural and Anthropogenic Stress: Lake Tahoe Nutrient Budget
    R825433C030 Mercury Distribution and Cycling in Sierra Nevada Waterbodies
    R825433C031 Pre-contact Forest Structure
    R825433C032 Identification and distribution of pest complexes in relation to late seral/old growth forest structure in the Lake Tahoe watershed
    R825433C033 Subalpine Marsh Plant Communities as Early Indicators of Ecosystem Stress
    R825433C034 Regional Hydrogeology and Contaminant Transport in a Sierra Nevada Ecosystem
    R825433C035 Border Rivers Watershed
    R825433C036 Toxicity Studies
    R825433C037 Watershed Assessment
    R825433C038 Microbiological Processes in Sediments
    R825433C039 Analytical and Biomarkers Core
    R825433C040 Organic Analysis
    R825433C041 Inorganic Analysis
    R825433C042 Immunoassay and Serum Markers
    R825433C043 Sensitive Biomarkers to Detect Biochemical Changes Indicating Multiple Stresses Including Chemically Induced Stresses
    R825433C044 Molecular, Cellular and Animal Biomarkers of Exposure and Effect
    R825433C045 Microbial Community Assays
    R825433C046 Cumulative and Integrative Biochemical Indicators
    R825433C047 Mercury and Iron Biogeochemistry
    R825433C048 Transport and Fate Core
    R825433C049 Role of Hydrogeologic Processes in Alpine Ecosystem Health
    R825433C050 Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
    R825433C051 Development of Pollutant Fate and Transport Models for Use in Terrestrial Ecosystem Exposure Assessment
    R825433C052 Pesticide Transport in Subsurface and Surface Water Systems
    R825433C053 Currents in Clear Lake
    R825433C054 Data Integration and Decision Support Core
    R825433C055 Spatial Patterns and Biodiversity
    R825433C056 Modeling Transport in Aquatic Systems
    R825433C057 Spatial and Temporal Trends in Water Quality
    R825433C058 Time Series Analysis and Modeling Ecological Risk
    R825433C059 WWW/Outreach
    R825433C060 Economic Effects of Multiple Stresses
    R825433C061 Effects of Nutrients on Algal Growth
    R825433C062 Nutrient Loading
    R825433C063 Subalpine Wetlands as Early Indicators of Ecosystem Stress
    R825433C064 Chlorinated Hydrocarbons
    R825433C065 Sierra Ozone Studies
    R825433C066 Assessment of Multiple Stresses on Soil Microbial Communities
    R825433C067 Terrestrial - Agriculture
    R825433C069 Molecular Epidemiology Core
    R825433C070 Serum Markers of Environmental Stress
    R825433C071 Development of Sensitive Biomarkers Based on Chemically Induced Changes in Expressions of Oncogenes
    R825433C072 Molecular Monitoring of Microbial Populations
    R825433C073 Aquatic - Rivers and Estuaries
    R825433C074 Border Rivers - Toxicity Studies

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    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.


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