In Situ Reactive Zones     

Evan K. Nyer  Suthan Suthersan 《Ground Water Monitoring & Remediation》1996,16(3):70-75

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National and Community Market Contributions of Wilderness     

Evan Hjerpe  Tom Holmes  Eric White 《社会与自然资源》2017,30(3):265-280

Wilderness attracts tourists and generates visitor spending in proximate communities as people enjoy Wilderness for outdoor recreation. Wilderness also attracts amenity migrants and out-of-region investments into surrounding regional economies. To investigate the amount and types of employment and income generated by Wilderness visitation, we conducted an economic contribution analysis of aggregate national visitor expenditures. The U.S. Forest Service National Visitor Use and Monitoring (NVUM) economic spending profiles were used to construct types and amounts of Wilderness visitor spending and were applied to an estimated 9.9 million annual visitors across federal agencies. IMPLAN modeling software was used to estimate total effects and multipliers for output, employment, income, and value added. Results show that some $500 million is annually spent in communities adjacent to Wilderness, generating a direct effect of 5,700 jobs and a total output effect over $700 million across numerous industries ($2012 including indirect and induced effects).  相似文献   

GSTA is a major glutathione S-transferase gene responsible for 4-hydroxynonenal conjugation in largemouth bass liver     

Robert T. Pham  David S. Barber  Evan P. Gallagher   《Marine environmental research》2004,58(2-5):485

We have previously shown that largemouth bass (Micropterus salmoides) has a remarkable ability to conjugate 4-hydroxy-2-nonenal (4HNE), a mutagenic and cytotoxic α,β-unsaturated aldehyde produced during the peroxidation of lipids. In addition, we have isolated a glutathione S-transferase cDNA (bass GSTA) that encodes a recombinant protein which is highly active in 4HNE conjugation and structurally similar to plaice (Pleuronectes platessa) GSTA. In the present study, HPLC-GST subunit analysis revealed the presence of at least two major GST isoforms in bass liver, with one peak constituting 80% of the total bass liver GST protein. Liquid chromatography mass spectrometry (LC–MS) and electrospray ionization analysis of the major bass GST subunit yielded a molecular weight of 26,396 kDa. Endo-proteinase Lys-C digestion and Edman degradation protein sequencing of this GST peak demonstrated that this protein was encoded by bass GSTA. Analysis of genomic DNA fragments isolated by nested PCR indicated the presence of a GST gene cluster in bass liver that contained GSTA, and was similar to a GST gene cluster characterized by Leaver et al., in plaice. Collectively, our data indicates the presence of a major GST in bass liver involved in the protection against oxidative stress. This GST is part of a gene cluster that may be conserved in certain freshwater and marine fish.  相似文献   

Fine-scale distribution of sardine (Sardina pilchardus) eggs and adults during a spawning event   总被引：2，自引：0，他引：2  

Juan Zwolinski  Evan Mason  Paulo B. Oliveira  Yorgos Stratoudakis 《Journal of Sea Research》2006,56(4):294-304

High-resolution acoustic and ichtyoplankton sampling with a ‘continuous under-way fish egg sampler (CUFES)’ was performed in two regions of approximately 100 square nautical miles off southern Iberian Peninsula, with the aim of studying the small scale distribution of sardine (Sardina pilchardus) adults and eggs during a spawning event. Very dense patches (246 eggs m^− 3) of recently spawned eggs with dimensions (up to 3 nautical miles wide) significantly larger than daytime sardine schools were present in both regions. Egg staging and ageing showed very little intra-sample variation, indicating a synchronous spawning period at dusk. The internal structure of the patches evaluated by variography showed very low internal variability, as if they consisted of a single unit. This hypothesis is confirmed by the acoustic finding of large sardine shoals with similar dimensions to those of the patches after sunset and throughout the night. During that period, adults were found near or in contact with the bottom, suggesting that spawning occurred at depth. A distinct patch of older eggs was found in both areas, but with a few nautical miles of horizontal separation. Their characteristics (a larger area, lower egg densities and a more irregular shape) indicate that these patches were exposed to dispersion and ‘stirring’ by physical forces, reshaping their initial appearance, while mesoscale water circulation could have displaced the core of the patches away by several kilometres within a day.  相似文献   

Sediment transport in Washington and Norfolk submarine canyons     

Evan B. Forde  Daniel J. Stanley  William B. Sawyer  Karen J. Slagle 《Applied Ocean Research》1981,3(2):59-62

A sediment study suggests that Washington and Norfolk canyons off the Mid-Atlantic States are not inactive, but have served periodically since the Late Pleistocene as conduits of sediment originating on the adjacent shelf and upper slope. Large quantities of sand occur in the canyon heads as thin beds and laminae, and on the continental slope as mixtures of sand (to $\text{>40\%}$), silt and clay that are extensively reworked by burrowing organisms. Sandy turbidites occur in the canyons on the rise. Basinward dispersal, from the outer shelf and uppermost slope, is recorded by heavy mineral suites and bioclastic components, primarily foraminifera of shallow marine origin, in the lower slope and upper continental rise canyon cores. The down-axis movement of material, presumably episodic, in the Holocene to recent results from offshelf spillover into canyon heads, failure on the steep walls bordering canyons on the slope, and resuspension by bottom currents.  相似文献   

Is This Site Contaminated?     

Evan K. Nyer  Charles D. Senz 《Ground Water Monitoring & Remediation》1995,15(1):71-74

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Using the Properties of Organic Compounds to Help Design a Treatment System     

Evan Nyer  Gary Boettcher  Bridget Morello 《Ground Water Monitoring & Remediation》1991,11(4):81-86

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Probability of plume interception using conditional simulation of hydraulic head and inverse modeling     

Dennis Weber  Dale Easley  Evan Englund 《Mathematical Geology》1991,23(2):219-239

A procedure to estimate the probability of intercepting a contaminant groundwater plume for monitoring network design has been developed and demonstrated. The objective of the procedure is to use all available information in a method that accounts for the heterogeneity of the aquifer and the paucity of data. The major components of the procedure are geostatistical conditional simulation and parameter estimation that are used sequentially to generate flow paths from a suspected contaminant source location to a designated monitoring transect. From the flow paths, a histogram is constructed that represents the spatial probability distribution of plume centerlines. With an independent estimate of the plume width, a relationship between the total cost and the probability of detecting a plume can be made. The method uses geostatistical information from hydraulic head measurements and is conditioned by the data and the physics of groundwater flow. This procedure was developed specifically for the design of monitoring systems at sites where very few, if any, hydraulic conductivity data are available.  相似文献   

Magic angle spinning NMR observation of sodium site exchange in nepheline at 500° C     

Jonathan F. Stebbins  Ian Farnan  Evan H. Williams  Jacques Roux 《Physics and Chemistry of Minerals》1989,16(8):763-766

Dynamics in minerals at time scales from seconds to microseconds are important in understanding mechanisms of displacive phase transitions, diffusion, and conductivity. High resolution, magic-angle-spinning (MAS) NMR spectroscopy can directly show the rates of exchange among sites, potentially providing less model-dependent information than more traditional NMR relaxation time measurements. Here we use a newly developed high temperature MAS probe (Doty Scientific, Inc.) to observe the exchange of Na⁺ among the alkali sites in a high-Na nepheline at temperatures as high as 500° C. Observed exchange rates are consistent with correlation times derived from cation diffusivity.  相似文献   

Hydrogeologists Should Manage Biological In Situ Remediations     

Evan K. Nyer 《Ground Water Monitoring & Remediation》1992,12(2):92-97

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