A marked decline in the Picoides borealis (Red-cockaded Woodpecker [RCW]) population at Noxubee National Wildlife Refuge, MS, was observed in 2002. Demographic changes - including absence of hatch-year birds, decreases in size of known groups, and loss of known groups-were identified during annual fall surveys and are uncharacteristic of RCW populations. In 2003, a serosurvey of 28 adult RCWs was conducted to investigate the presence of West Nile virus (WNV) exposure in the population, possibly providing insight into whether WNV may have been responsible for this decline. Blood smears were also examined from these birds for blood parasites. We found no evidence of West Nile virus exposure or blood parasites in any of the RCWs sampled. Further monitoring of the RCW population and WNV activity in other species at Noxubee NWR is recommended to further evaluate the potential role of WNV and blood parasites in their decline.
","language":"English","publisher":"Eagle Hill Institute","doi":"10.1656/1528-7092(2006)5[561:ERWFET]2.0.CO;2","usgsCitation":"Dusek, R., Richardson, D., Egstad, K.F., and Heisey, D.M., 2006, Evaluating red-cockaded woodpeckers for exposure to West Nile Virus and blood parasites: Southeastern Naturalist, v. 5, no. 3, p. 561-565, https://doi.org/10.1656/1528-7092(2006)5[561:ERWFET]2.0.CO;2.","productDescription":"5 p.","startPage":"561","endPage":"565","numberOfPages":"5","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":456,"text":"National Wildlife Health Center","active":true,"usgs":true}],"links":[{"id":134253,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Mississippi","otherGeospatial":"Noxubee National Wildlife Refuge","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -88.92196655273438,\n 33.4039312002347\n ],\n [\n -88.85261535644531,\n 33.444620186402545\n ],\n [\n -88.57589721679688,\n 33.18238738446303\n ],\n [\n -88.57589721679688,\n 33.15767283191024\n ],\n [\n -88.57933044433594,\n 33.12432588813153\n ],\n [\n -88.63838195800781,\n 33.100745405144245\n ],\n [\n -88.77159118652344,\n 33.101895819445275\n ],\n [\n -88.83132934570312,\n 33.106497326059845\n ],\n [\n -88.85467529296875,\n 33.11627472754512\n ],\n [\n -88.87596130371094,\n 33.271990955382115\n ],\n [\n -88.93020629882812,\n 33.354620418436255\n ],\n [\n -88.92127990722655,\n 33.40163829558248\n ],\n [\n -88.92196655273438,\n 33.4039312002347\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"5","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a09e4b07f02db5fb084","contributors":{"authors":[{"text":"Dusek, Robert J. 0000-0001-6177-7479","orcid":"https://orcid.org/0000-0001-6177-7479","contributorId":30203,"corporation":false,"usgs":true,"family":"Dusek","given":"Robert J.","affiliations":[],"preferred":false,"id":313559,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Richardson, D.","contributorId":46065,"corporation":false,"usgs":true,"family":"Richardson","given":"D.","email":"","affiliations":[],"preferred":false,"id":313561,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Egstad, Kristina F. 0000-0002-2755-6098 kegstad@usgs.gov","orcid":"https://orcid.org/0000-0002-2755-6098","contributorId":5120,"corporation":false,"usgs":true,"family":"Egstad","given":"Kristina","email":"kegstad@usgs.gov","middleInitial":"F.","affiliations":[],"preferred":true,"id":313560,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Heisey, Dennis M. dheisey@usgs.gov","contributorId":2455,"corporation":false,"usgs":true,"family":"Heisey","given":"Dennis","email":"dheisey@usgs.gov","middleInitial":"M.","affiliations":[{"id":456,"text":"National Wildlife Health Center","active":true,"usgs":true}],"preferred":true,"id":313558,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":1003348,"text":"1003348 - 2006 - Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River","interactions":[],"lastModifiedDate":"2012-02-02T00:04:48","indexId":"1003348","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River","docAbstract":"We examined data collected on fish assemblage structure among three differing floodplain types (broad, moderate, and narrow) during the 1993 flood in the unimpounded reach of the upper Mississippi River. This 500 year flood event provided a unique opportunity to investigate fish-floodplain function because the main river channel is otherwise typically disjunct from approximately 82% of its floodplain by an extensive levee system. Fishes were sampled during three separate periods, and 42 species of adult and young-of-the-year (YOY) fishes were captured. Analysis of similarity (ANOSIM) revealed a significant and distinguishable difference between both adult and YOY assemblage structure among the three floodplain types. Analysis of variance revealed that Secchi transparency, turbidity, water velocity, and dissolved oxygen were significantly different among the floodplain types. However, only depth of gear deployment and Secchi transparency were significantly correlated with adult assemblage structure. None of these variables were significantly correlated with YOY assemblage structure. The numerically abundant families (adult and YOY catches combined) on the floodplain included Centrarchidae, Ictularidae, and Cyprinidae. Both native and non-native fishes were captured on the floodplain, and several of the numerically abundant species that were captured on the floodplain peaked in catch-per-unit-effort 1-3 years after the 1993 flood event. This suggests that some species may have used flooded terrestrial habitat for spawning, feeding, or both. The findings from our study provide much needed insight into fish-floodplain function in a temperate, channelized river system and suggest that lateral connectivity of the main river channel to less degraded reaches of its floodplain should become a management priority not only to maintain faunal biodiversity but also potentially reduce the impacts of non-native species in large river systems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","usgsCitation":"Barko, V., Herzog, D., and O’Connell, M.T., 2006, Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River: Wetlands, v. 26, no. 1, p. 244-257.","productDescription":"pp. 244-257","startPage":"244","endPage":"257","numberOfPages":"14","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":133885,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":15585,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://www.bioone.org/doi/abs/10.1672/0277-5212%282006%2926%5B244%3AROFTFC%5D2.0.CO%3B2","linkFileType":{"id":5,"text":"html"},"description":"4356.000000000000000"}],"volume":"26","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a51e4b07f02db629bf1","contributors":{"authors":[{"text":"Barko, V.A.","contributorId":75477,"corporation":false,"usgs":true,"family":"Barko","given":"V.A.","email":"","affiliations":[],"preferred":false,"id":313139,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herzog, D.P.","contributorId":103218,"corporation":false,"usgs":true,"family":"Herzog","given":"D.P.","email":"","affiliations":[],"preferred":false,"id":313140,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Connell, M. T.","contributorId":105679,"corporation":false,"usgs":true,"family":"O’Connell","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":313141,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70028676,"text":"70028676 - 2006 - Mineral mapping and applications of imaging spectroscopy","interactions":[],"lastModifiedDate":"2012-03-12T17:20:44","indexId":"70028676","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Mineral mapping and applications of imaging spectroscopy","docAbstract":"Spectroscopy is a tool that has been used for decades to identify, understand, and quantify solid, liquid, or gaseous materials, especially in the laboratory. In disciplines ranging from astronomy to chemistry, spectroscopic measurements are used to detect absorption and emission features due to specific chemical bonds, and detailed analyses are used to determine the abundance and physical state of the detected absorbing/emitting species. Spectroscopic measurements have a long history in the study of the Earth and planets. Up to the 1990s remote spectroscopic measurements of Earth and planets were dominated by multispectral imaging experiments that collect high-quality images in a few, usually broad, spectral bands or with point spectrometers that obtained good spectral resolution but at only a few spatial positions. However, a new generation of sensors is now available that combines imaging with spectroscopy to create the new discipline of imaging spectroscopy. Imaging spectrometers acquire data with enough spectral range, resolution, and sampling at every pixel in a raster image so that individual absorption features can be identified and spatially mapped (Goetz et al., 1985).","largerWorkTitle":"International Geoscience and Remote Sensing Symposium (IGARSS)","conferenceTitle":"2006 IEEE International Geoscience and Remote Sensing Symposium, IGARSS","conferenceDate":"31 July 2006 through 4 August 2006","conferenceLocation":"Denver, CO","language":"English","doi":"10.1109/IGARSS.2006.514","isbn":"0780395107; 9780780395107","usgsCitation":"Clark, R.N., Boardman, J., Mustard, J., Kruse, F., Ong, C., Pieters, C., and Swayze, G., 2006, Mineral mapping and applications of imaging spectroscopy, in International Geoscience and Remote Sensing Symposium (IGARSS), Denver, CO, 31 July 2006 through 4 August 2006, p. 1986-1989, https://doi.org/10.1109/IGARSS.2006.514.","startPage":"1986","endPage":"1989","numberOfPages":"4","costCenters":[],"links":[{"id":209866,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1109/IGARSS.2006.514"},{"id":236607,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5797e4b0c8380cd6dd89","contributors":{"authors":[{"text":"Clark, R. N.","contributorId":6568,"corporation":false,"usgs":true,"family":"Clark","given":"R.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":419212,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boardman, J.","contributorId":74184,"corporation":false,"usgs":true,"family":"Boardman","given":"J.","affiliations":[],"preferred":false,"id":419214,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mustard, J.","contributorId":103458,"corporation":false,"usgs":true,"family":"Mustard","given":"J.","email":"","affiliations":[],"preferred":false,"id":419217,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kruse, F.","contributorId":84142,"corporation":false,"usgs":true,"family":"Kruse","given":"F.","email":"","affiliations":[],"preferred":false,"id":419215,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ong, C.","contributorId":96071,"corporation":false,"usgs":true,"family":"Ong","given":"C.","email":"","affiliations":[],"preferred":false,"id":419216,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Pieters, C.","contributorId":104636,"corporation":false,"usgs":true,"family":"Pieters","given":"C.","email":"","affiliations":[],"preferred":false,"id":419218,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Swayze, G.A. 0000-0002-1814-7823","orcid":"https://orcid.org/0000-0002-1814-7823","contributorId":21570,"corporation":false,"usgs":true,"family":"Swayze","given":"G.A.","affiliations":[],"preferred":false,"id":419213,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70028641,"text":"70028641 - 2006 - Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70028641","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1474,"text":"Écoscience","active":true,"publicationSubtype":{"id":10}},"title":"Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents","docAbstract":"Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecoscience","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2980/1195-6860(2006)13[539:JTYBSA]2.0.CO;2","issn":"11956860","usgsCitation":"Vander Wall, S., Esque, T., Haines, D., Garnett, M., and Waitman, B., 2006, Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents: Écoscience, v. 13, no. 4, p. 539-543, https://doi.org/10.2980/1195-6860(2006)13[539:JTYBSA]2.0.CO;2.","startPage":"539","endPage":"543","numberOfPages":"5","costCenters":[],"links":[{"id":209814,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2980/1195-6860(2006)13[539:JTYBSA]2.0.CO;2"},{"id":236537,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"13","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a400de4b0c8380cd64a23","contributors":{"authors":[{"text":"Vander Wall, S.B.","contributorId":92475,"corporation":false,"usgs":false,"family":"Vander Wall","given":"S.B.","email":"","affiliations":[{"id":16686,"text":"University of Nevada, Reno","active":true,"usgs":false}],"preferred":false,"id":418982,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Esque, T.","contributorId":19893,"corporation":false,"usgs":true,"family":"Esque","given":"T.","affiliations":[],"preferred":false,"id":418978,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Haines, D.","contributorId":30424,"corporation":false,"usgs":true,"family":"Haines","given":"D.","email":"","affiliations":[],"preferred":false,"id":418979,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Garnett, M.","contributorId":36737,"corporation":false,"usgs":true,"family":"Garnett","given":"M.","email":"","affiliations":[],"preferred":false,"id":418980,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Waitman, B.A.","contributorId":70908,"corporation":false,"usgs":false,"family":"Waitman","given":"B.A.","email":"","affiliations":[{"id":7214,"text":"University of California, Davis","active":true,"usgs":false}],"preferred":false,"id":418981,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70028449,"text":"70028449 - 2006 - Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification","interactions":[],"lastModifiedDate":"2018-10-22T10:09:19","indexId":"70028449","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3711,"text":"Water Environment Research","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification","docAbstract":"The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure-oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire-retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical-chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol-water partition coefficients.","language":"English","publisher":"Water Environment Federation","doi":"10.2175/106143005X82244","issn":"10614303","usgsCitation":"Levine, A., Meyer, M.T., and Kish, G., 2006, Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification: Water Environment Research, v. 78, no. 11, p. 2276-2285, https://doi.org/10.2175/106143005X82244.","productDescription":"10 p.","startPage":"2276","endPage":"2285","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":210409,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2175/106143005X82244"},{"id":237317,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"78","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0cede4b0c8380cd52d57","contributors":{"authors":[{"text":"Levine, A.D.","contributorId":91679,"corporation":false,"usgs":true,"family":"Levine","given":"A.D.","email":"","affiliations":[],"preferred":false,"id":418103,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Meyer, M. T.","contributorId":92279,"corporation":false,"usgs":true,"family":"Meyer","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":418104,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kish, G.","contributorId":24553,"corporation":false,"usgs":true,"family":"Kish","given":"G.","affiliations":[],"preferred":false,"id":418102,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70028640,"text":"70028640 - 2006 - New ghost-node method for linking different models with varied grid refinement","interactions":[],"lastModifiedDate":"2012-03-12T17:21:00","indexId":"70028640","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"New ghost-node method for linking different models with varied grid refinement","docAbstract":"A flexible, robust method for linking grids of locally refined ground-water flow models constructed with different numerical methods is needed to address a variety of hydrologic problems. This work outlines and tests a new ghost-node model-linking method for a refined \"child\" model that is contained within a larger and coarser \"parent\" model that is based on the iterative method of Steffen W. Mehl and Mary C. Hill (2002, Advances in Water Res., 25, p. 497-511; 2004, Advances in Water Res., 27, p. 899-912). The method is applicable to steady-state solutions for ground-water flow. Tests are presented for a homogeneous two-dimensional system that has matching grids (parent cells border an integer number of child cells) or nonmatching grids. The coupled grids are simulated by using the finite-difference and finite-element models MODFLOW and FEHM, respectively. The simulations require no alteration of the MODFLOW or FEHM models and are executed using a batch file on Windows operating systems. Results indicate that when the grids are matched spatially so that nodes and child-cell boundaries are aligned, the new coupling technique has error nearly equal to that when coupling two MODFLOW models. When the grids are nonmatching, model accuracy is slightly increased compared to that for matching-grid cases. Overall, results indicate that the ghost-node technique is a viable means to couple distinct models because the overall head and flow errors relative to the analytical solution are less than if only the regional coarse-grid model was used to simulate flow in the child model's domain.","largerWorkTitle":"Proceedings of the 11th International High Level Radioactive Waste Management Conference, IHLRWM","conferenceTitle":"11th International High Level Radioactive Waste Management Conference","conferenceDate":"30 April 2006 through 4 May 2006","conferenceLocation":"Las Vegas, NV","language":"English","isbn":"0894486918; 9780894486913","usgsCitation":"James, S., Dickinson, J., Mehl, S., Hill, M.C., Leake, S.A., Zyvoloski, G., and Eddebbarh, A., 2006, New ghost-node method for linking different models with varied grid refinement, in Proceedings of the 11th International High Level Radioactive Waste Management Conference, IHLRWM, v. 2006, Las Vegas, NV, 30 April 2006 through 4 May 2006, p. 338-344.","startPage":"338","endPage":"344","numberOfPages":"7","costCenters":[],"links":[{"id":236506,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"2006","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a658be4b0c8380cd72c10","contributors":{"authors":[{"text":"James, S.C.","contributorId":103059,"corporation":false,"usgs":true,"family":"James","given":"S.C.","email":"","affiliations":[],"preferred":false,"id":418977,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dickinson, J.E.","contributorId":28790,"corporation":false,"usgs":true,"family":"Dickinson","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":418972,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mehl, S.W.","contributorId":84555,"corporation":false,"usgs":true,"family":"Mehl","given":"S.W.","affiliations":[],"preferred":false,"id":418975,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hill, M. C.","contributorId":48993,"corporation":false,"usgs":true,"family":"Hill","given":"M.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":418973,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Leake, S. A.","contributorId":52164,"corporation":false,"usgs":true,"family":"Leake","given":"S.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":418974,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Zyvoloski, G.A.","contributorId":20123,"corporation":false,"usgs":true,"family":"Zyvoloski","given":"G.A.","email":"","affiliations":[],"preferred":false,"id":418971,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Eddebbarh, A.-A.","contributorId":101425,"corporation":false,"usgs":true,"family":"Eddebbarh","given":"A.-A.","email":"","affiliations":[],"preferred":false,"id":418976,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70028554,"text":"70028554 - 2006 - Testing the concept of drift shadow at Yucca Mountain, Nevada","interactions":[],"lastModifiedDate":"2012-03-12T17:20:56","indexId":"70028554","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Testing the concept of drift shadow at Yucca Mountain, Nevada","docAbstract":"If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain, To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or 238U-234U-230Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All rock samples show 234U depletion relative to parent 238U indicating varying degrees of water-rock interaction over the past million years. Variations in 234U/238U activity ratios indicate that depletion of 234U relative to 238U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of 234U/ 238U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors.","largerWorkTitle":"Proceedings of the 11th International High Level Radioactive Waste Management Conference, IHLRWM","conferenceTitle":"11th International High Level Radioactive Waste Management Conference","conferenceDate":"30 April 2006 through 4 May 2006","conferenceLocation":"Las Vegas, NV","language":"English","isbn":"0894486918; 9780894486913","usgsCitation":"Paces, J., Neymark, L., Ghezzehei, T., and Dobson, P., 2006, Testing the concept of drift shadow at Yucca Mountain, Nevada, in Proceedings of the 11th International High Level Radioactive Waste Management Conference, IHLRWM, v. 2006, Las Vegas, NV, 30 April 2006 through 4 May 2006, p. 278-285.","startPage":"278","endPage":"285","numberOfPages":"8","costCenters":[],"links":[{"id":236249,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"2006","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba5d2e4b08c986b320cdb","contributors":{"authors":[{"text":"Paces, J.B. 0000-0002-9809-8493","orcid":"https://orcid.org/0000-0002-9809-8493","contributorId":27482,"corporation":false,"usgs":true,"family":"Paces","given":"J.B.","affiliations":[],"preferred":false,"id":418575,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Neymark, L.A. 0000-0003-4190-0278","orcid":"https://orcid.org/0000-0003-4190-0278","contributorId":56673,"corporation":false,"usgs":true,"family":"Neymark","given":"L.A.","affiliations":[],"preferred":false,"id":418576,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ghezzehei, T.","contributorId":86160,"corporation":false,"usgs":true,"family":"Ghezzehei","given":"T.","affiliations":[],"preferred":false,"id":418578,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dobson, P.F.","contributorId":68466,"corporation":false,"usgs":true,"family":"Dobson","given":"P.F.","email":"","affiliations":[],"preferred":false,"id":418577,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70028555,"text":"70028555 - 2006 - Guideline for assessing the performance of electric power systems in natural hazard and human threat events","interactions":[],"lastModifiedDate":"2012-03-12T17:20:56","indexId":"70028555","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Guideline for assessing the performance of electric power systems in natural hazard and human threat events","docAbstract":"Electric power utilities are familiar with and skilled in preparing for and responding to almost-routine natural hazard events such as strong wind and ice storms and seasonal floods, as well as intentional human acts such as vandalism. Recent extreme weather (hurricanes Katrina and Rita), extremely destructive international earthquakes (in Sumatra and Pakistan), and nation-wide concerns regarding future terrorist attacks have increased the pressure on utilities to take appropriate steps to avoid being overwhelmed by such infrequent and exceedingly severe events. Determining what constitutes the appropriate steps to take requires various levels of understanding of the specific hazards and the risks faced by the utility. The American Lifelines Alliance (www. americanlifelinesalliance.org) has prepared a Guideline that provides clear, concise, and nationally-applicable guidance on determining the scope and level of effort necessary to assess power system performance in the wide range of natural hazard or human threat events. Included in this Guideline are specific procedures to follow and information to consider in performing standardized assessments. With the results of such assessments, utility owners can effectively establish and carry out risk management programs that will lead to achieving appropriate levels of performance in future events. The Guideline incorporates an inquiry-driven process with a two-phase performance assessment that can be applied to power systems of any size. The screening phase enables systems or components that are clearly not at risk to be screened out early. The subsequent analysis phase uses results from the screening phase to prioritize and allocate resources for more detailed assessments of hazard, vulnerability, and system performance. This process helps assure that the scope of the assessment meets the specific performance objectives of the inquiry. A case history is presented to illustrate the type of experience with an inquiry-driven process that was considered in developing the Guideline to meet the diverse needs of utility personnel in engineering, operations, and management. Copyright ASCE 2007.","largerWorkTitle":"Electrical Transmission Line and Substation Structures: Structural Reliability in a Changing World - Proceedings of the 2006 Electrical Transmission Conference","conferenceTitle":"2006 Electrical Transmission Conference","conferenceDate":"15 October 2006 through 19 October 2006","conferenceLocation":"Birmingham, AL","language":"English","doi":"10.1061/40790(218)4","isbn":"0784407908; 9780784407905","usgsCitation":"Savage, W., Nishenko, S., Honegger, D., and Kempner, L., 2006, Guideline for assessing the performance of electric power systems in natural hazard and human threat events, in Electrical Transmission Line and Substation Structures: Structural Reliability in a Changing World - Proceedings of the 2006 Electrical Transmission Conference, v. 218, Birmingham, AL, 15 October 2006 through 19 October 2006, p. 39-46, https://doi.org/10.1061/40790(218)4.","startPage":"39","endPage":"46","numberOfPages":"8","costCenters":[],"links":[{"id":209628,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40790(218)4"},{"id":236288,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"218","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505a2e30e4b0c8380cd5c36a","contributors":{"authors":[{"text":"Savage, W.U.","contributorId":25258,"corporation":false,"usgs":true,"family":"Savage","given":"W.U.","email":"","affiliations":[],"preferred":false,"id":418581,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nishenko, S.P.","contributorId":8072,"corporation":false,"usgs":true,"family":"Nishenko","given":"S.P.","email":"","affiliations":[],"preferred":false,"id":418579,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Honegger, D.G.","contributorId":17401,"corporation":false,"usgs":true,"family":"Honegger","given":"D.G.","email":"","affiliations":[],"preferred":false,"id":418580,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kempner, L. Jr.","contributorId":40402,"corporation":false,"usgs":true,"family":"Kempner","given":"L.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":418582,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70028642,"text":"70028642 - 2006 - Pelagic seabird surveys in the Tuamotu and Gambier Archipelagos, French Polynesia","interactions":[],"lastModifiedDate":"2018-08-21T13:08:10","indexId":"70028642","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2675,"text":"Marine Ornithology: Journal of Seabird Research and Conservation","onlineIssn":"2074-1235","printIssn":"1018-3337","active":true,"publicationSubtype":{"id":10}},"title":"Pelagic seabird surveys in the Tuamotu and Gambier Archipelagos, French Polynesia","docAbstract":"We conducted pelagic seabird surveys in the Gambier and Tuamotu Archipelagos in the southeastern Pacific Ocean totaling 40 hours during 7-27 March 2003 and 22.5 hours during 22-27 July 2001. We used a 300-m-wide strip transect to estimate seabird density, and we estimated relative abundance of birds at all distances. In 2001, we observed a total of 326 birds of 18 species. The mean relative abundance of all birds was 14.3 ?? 3.1/h. Red-footed Booby Sula sula was the most abundant species (5.6/h), followed by White Tern Gygis alba (3.4/h), and Great Crested or Swift Tern Sterna bergii (1.2/h). In 2003, we observed a total of 1463 birds of 25 species. The mean relative abundance of all birds was 36.6 ?? 11.4/h and the mean density of all birds was 4.14 ?? 0.72/km2. Brown Noddy Anous stolidus was the most abundant species (17.6/h, 1.5/km2), followed by White Tern (8.4/h, 1.3/km2), and Red-footed Booby (4.6/h, 0.8/km2). Several globally or locally rare species were observed infrequently, including Phoenix Petrel Pterodroma alba (0.1/h, 0.03/km2). Distribution of birds was uneven, with long periods of no birds punctuated by occasional feeding flocks. In 2003, species diversity was related to length of observation period, with more species observed on longer segments (r2 = 0.58, F1.5 = 6.03, P = 0.05). Although the duration and extent of our surveys were limited, these data are valuable because little published information is available on pelagic seabirds in southeastern Polynesia.","language":"English","publisher":"Pacific Seabird Group","issn":"10183337","usgsCitation":"Vanderwerf, E.A., Pierce, R.J., Gill, V., Wragg, G., Raust, P., and Tibbitts, T.L., 2006, Pelagic seabird surveys in the Tuamotu and Gambier Archipelagos, French Polynesia: Marine Ornithology: Journal of Seabird Research and Conservation, v. 34, no. 1, p. 65-70.","productDescription":"6 p.","startPage":"65","endPage":"70","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"links":[{"id":236538,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":337053,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://www.marineornithology.org/content/get.cgi?rn=684"}],"country":"France","state":"French Polynesia","otherGeospatial":"Gambier Archipelago, Tuamotu Archipelago","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -150,\n -10\n ],\n [\n -134,\n -10\n ],\n [\n -134,\n -25\n ],\n [\n -150,\n -25\n ],\n [\n -150,\n -10\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"34","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a763ce4b0c8380cd77fd7","contributors":{"authors":[{"text":"Vanderwerf, Eric A.","contributorId":104689,"corporation":false,"usgs":false,"family":"Vanderwerf","given":"Eric","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":418988,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pierce, Ray J.","contributorId":16635,"corporation":false,"usgs":false,"family":"Pierce","given":"Ray","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":418984,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gill, Verena A.","contributorId":140658,"corporation":false,"usgs":false,"family":"Gill","given":"Verena A.","affiliations":[{"id":6678,"text":"U.S. Fish and Wildlife Service, Alaska Maritime National Wildlife Refuge","active":true,"usgs":false}],"preferred":false,"id":418986,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wragg, Graham","contributorId":8272,"corporation":false,"usgs":false,"family":"Wragg","given":"Graham","email":"","affiliations":[],"preferred":false,"id":418983,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Raust, Philippe","contributorId":46288,"corporation":false,"usgs":false,"family":"Raust","given":"Philippe","email":"","affiliations":[],"preferred":false,"id":418987,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Tibbitts, T. Lee 0000-0002-0290-7592 ltibbitts@usgs.gov","orcid":"https://orcid.org/0000-0002-0290-7592","contributorId":140455,"corporation":false,"usgs":true,"family":"Tibbitts","given":"T.","email":"ltibbitts@usgs.gov","middleInitial":"Lee","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":false,"id":418985,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028552,"text":"70028552 - 2006 - Environmental contaminants in fish and their associated risk to piscivorous wildlife in the Yukon River Basin, Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:20:43","indexId":"70028552","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":887,"text":"Archives of Environmental Contamination and Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"Environmental contaminants in fish and their associated risk to piscivorous wildlife in the Yukon River Basin, Alaska","docAbstract":"Organochlorine chemical residues and elemental contaminants were measured in northern pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) from 10 sites in the Yukon River Basin (YRB) during 2002. Contaminant concentrations were compared to historical YRB data and to toxicity thresholds for fish and piscivorous wildlife from the scientific literature. A risk analysis was conducted to screen for potential hazards to piscivorous wildlife for contaminants that exceeded literature-based toxicity thresholds. Concentrations of total DDT (sum of p,p???-homologs; 1.09-13.6 ng/g), total chlordane (0.67-7.5 ng/g), dieldrin (<0.16-0.6 ng/g), toxaphene (<11-34 ng/g), total PCBs (<20-87 ng/g), TCDD-EQ (???1.7 pg/g), arsenic (0.03-1.95 ??g/g), cadmium (<0.02-0.12 ??g/g), copper (0.41-1.49 ??g/g), and lead (<0.21-0.27 ??g/g) did not exceed toxicity thresholds for growth and reproduction in YRB fish. Concentrations of mercury (0.08-0.65 ??g/g), selenium (0.23-0.85 ??g/g), and zinc (11-56 ??g/g) exceeded toxicity thresholds in one or more samples and were included in the risk analysis for piscivorous wildlife. No effect hazard concentrations (NEHCs) and low effect hazard concentrations (LEHCs), derived from literature-based toxicity reference values and avian and mammalian life history parameters, were calculated for mercury, selenium, and zinc. Mercury concentrations in YRB fish exceeded the NEHCs for all bird and small mammal models, which indicated that mercury concentrations in fish may represent a risk to piscivorous wildlife throughout the YRB. Low risk to piscivorous wildlife was associated with selenium and zinc concentrations in YRB fish. Selenium and zinc concentrations exceeded the NEHCs and LEHCs for only the small bird model. These results indicate that mercury should continue to be monitored and assessed in Alaskan fish and wildlife. ?? 2006 Springer Science+Business Media, Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Archives of Environmental Contamination and Toxicology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s00244-005-0310-6","issn":"00904341","usgsCitation":"Hinck, J., Schmitt, C., Echols, K.R., May, T., Orazio, C., and Tillitt, D.E., 2006, Environmental contaminants in fish and their associated risk to piscivorous wildlife in the Yukon River Basin, Alaska: Archives of Environmental Contamination and Toxicology, v. 51, no. 4, p. 661-672, https://doi.org/10.1007/s00244-005-0310-6.","startPage":"661","endPage":"672","numberOfPages":"12","costCenters":[],"links":[{"id":209990,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s00244-005-0310-6"},{"id":236774,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"51","issue":"4","noUsgsAuthors":false,"publicationDate":"2006-09-23","publicationStatus":"PW","scienceBaseUri":"505a09b1e4b0c8380cd5200a","contributors":{"authors":[{"text":"Hinck, J.E.","contributorId":47560,"corporation":false,"usgs":true,"family":"Hinck","given":"J.E.","affiliations":[],"preferred":false,"id":418566,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schmitt, C. J. 0000-0001-6804-2360","orcid":"https://orcid.org/0000-0001-6804-2360","contributorId":56339,"corporation":false,"usgs":true,"family":"Schmitt","given":"C. J.","affiliations":[],"preferred":false,"id":418567,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Echols, K. R.","contributorId":32637,"corporation":false,"usgs":true,"family":"Echols","given":"K.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":418565,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"May, T.W.","contributorId":75878,"corporation":false,"usgs":true,"family":"May","given":"T.W.","email":"","affiliations":[],"preferred":false,"id":418569,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Orazio, C.E.","contributorId":68440,"corporation":false,"usgs":true,"family":"Orazio","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":418568,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Tillitt, D. E.","contributorId":83462,"corporation":false,"usgs":true,"family":"Tillitt","given":"D.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":418570,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028638,"text":"70028638 - 2006 - Grassland songbirds in a dynamic management landscape: Behavioral responses and management strategies","interactions":[],"lastModifiedDate":"2012-03-12T17:21:00","indexId":"70028638","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1450,"text":"Ecological Applications","active":true,"publicationSubtype":{"id":10}},"title":"Grassland songbirds in a dynamic management landscape: Behavioral responses and management strategies","docAbstract":"In recent decades, earlier and more frequent harvests of agricultural grasslands have been implicated as a major cause of population declines in grassland songbirds. From 2002 to 2005, in the Champlain Valley of Vermont and New York, USA, we studied the reproductive success of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. Both the number of fledglings per female per year and nest success (logistic-exposure method) varied among treatments and between species. Although birds initiated nests earlier on early-hayed fields compared to others, haying caused 99% of active Savannah Sparrow and 100% of active Bobolink nests to fail. Both the initial cutting date and time between cuttings influenced renesting behavior. After haying, Savannah Sparrows generally remained on early-hayed fields and immediately renested (clutch completion 15.6 ?? 1.28 days post-haying; all values are reported as mean ?? SE), while Bobolinks abandoned the fields for at least two weeks (mean clutch completion 33 ?? 0.82 days post-haying). While female Savannah Sparrows fledged more offspring per year (1.28 ?? 0.16) than female Bobolinks (0.05 ?? 0.05), reproductive success on early-hayed fields was low. The number of fledglings per female per year was greater on middle-hayed fields (Savannah Sparrows, 3.47 ?? 0.42; Bobolinks, 2.22 ?? 0.26), and late-hayed fields (Savannah Sparrows, 3.29 ?? 0.30; Bobolinks, 2.79 ?? 0.18). Reproductive success was moderate on rotationally grazed pastures, where female Savannah Sparrows and female Bobolinks produced 2.32 ?? 0.25 and 1.79 ?? 0.33 fledgling per year, respectively. We simultaneously conducted cutting surveys throughout the Champlain Valley and found that 3-8% of hayfield habitat was cut by 1-4 June, 25-40% by 12-16 June, and 32-60% by 28 June-2 July. Thus, the majority of grassland habitat was cut during the breeding season; however, late-hayed fields served as high-quality reserves for late-nesting female Bobolinks that were displaced from previously hayed fields. For fields first cut in May, a 65-day interval between cuts could provide enough time for both species to successfully fledge young. ?? 2006 by the Ecological Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Applications","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1890/1051-0761(2006)016[2235:GSIADM]2.0.CO;2","issn":"10510761","usgsCitation":"Perlut, N., Strong, A., Donovan, T., and Buckley, N.J., 2006, Grassland songbirds in a dynamic management landscape: Behavioral responses and management strategies: Ecological Applications, v. 16, no. 6, p. 2235-2247, https://doi.org/10.1890/1051-0761(2006)016[2235:GSIADM]2.0.CO;2.","startPage":"2235","endPage":"2247","numberOfPages":"13","costCenters":[],"links":[{"id":209762,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1890/1051-0761(2006)016[2235:GSIADM]2.0.CO;2"},{"id":236468,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a29e9e4b0c8380cd5ad37","contributors":{"authors":[{"text":"Perlut, N.G.","contributorId":12671,"corporation":false,"usgs":true,"family":"Perlut","given":"N.G.","affiliations":[],"preferred":false,"id":418964,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Strong, A.M.","contributorId":39568,"corporation":false,"usgs":true,"family":"Strong","given":"A.M.","email":"","affiliations":[],"preferred":false,"id":418966,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Donovan, T.M.","contributorId":91602,"corporation":false,"usgs":true,"family":"Donovan","given":"T.M.","email":"","affiliations":[],"preferred":false,"id":418967,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Buckley, N. J.","contributorId":38757,"corporation":false,"usgs":false,"family":"Buckley","given":"N.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":418965,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70028562,"text":"70028562 - 2006 - Effects of sample survey design on the accuracy of classification tree models in species distribution models","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70028562","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1458,"text":"Ecological Modelling","active":true,"publicationSubtype":{"id":10}},"title":"Effects of sample survey design on the accuracy of classification tree models in species distribution models","docAbstract":"We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by resubstitution rates were similar for each lichen species irrespective of the underlying sample survey form. Cross-validation estimates of prediction accuracies were lower than resubstitution accuracies for all species and both design types, and in all cases were closer to the true prediction accuracies based on the EVALUATION data set. We argue that greater emphasis should be placed on calculating and reporting cross-validation accuracy rates rather than simple resubstitution accuracy rates. Evaluation of the DESIGN and PURPOSIVE tree models on the EVALUATION data set shows significantly lower prediction accuracy for the PURPOSIVE tree models relative to the DESIGN models, indicating that non-probabilistic sample surveys may generate models with limited predictive capability. These differences were consistent across all four lichen species, with 11 of the 12 possible species and sample survey type comparisons having significantly lower accuracy rates. Some differences in accuracy were as large as 50%. The classification tree structures also differed considerably both among and within the modelled species, depending on the sample survey form. Overlap in the predictor variables selected by the DESIGN and PURPOSIVE tree models ranged from only 20% to 38%, indicating the classification trees fit the two evaluated survey forms on different sets of predictor variables. The magnitude of these differences in predictor variables throws doubt on ecological interpretation derived from prediction models based on non-probabilistic sample surveys. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Modelling","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolmodel.2006.05.016","issn":"03043800","usgsCitation":"Edwards, T., Cutler, D., Zimmermann, N., Geiser, L., and Moisen, G.G., 2006, Effects of sample survey design on the accuracy of classification tree models in species distribution models: Ecological Modelling, v. 199, no. 2, p. 132-141, https://doi.org/10.1016/j.ecolmodel.2006.05.016.","startPage":"132","endPage":"141","numberOfPages":"10","costCenters":[],"links":[{"id":209758,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolmodel.2006.05.016"},{"id":236462,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"199","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a07bde4b0c8380cd517e5","contributors":{"authors":[{"text":"Edwards, T.C. Jr. 0000-0002-0773-0909","orcid":"https://orcid.org/0000-0002-0773-0909","contributorId":76486,"corporation":false,"usgs":true,"family":"Edwards","given":"T.C.","suffix":"Jr.","affiliations":[],"preferred":false,"id":418610,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cutler, D.R.","contributorId":89684,"corporation":false,"usgs":true,"family":"Cutler","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":418611,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zimmermann, N.E.","contributorId":24547,"corporation":false,"usgs":true,"family":"Zimmermann","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":418609,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Geiser, L.","contributorId":23498,"corporation":false,"usgs":true,"family":"Geiser","given":"L.","email":"","affiliations":[],"preferred":false,"id":418608,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Moisen, Gretchen G.","contributorId":15781,"corporation":false,"usgs":false,"family":"Moisen","given":"Gretchen","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":418607,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70028565,"text":"70028565 - 2006 - Buffelgrass fuel loads in Saguaro National Park, Arizona, increase fire danger and threaten native species","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70028565","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3014,"text":"Park Science","active":true,"publicationSubtype":{"id":10}},"title":"Buffelgrass fuel loads in Saguaro National Park, Arizona, increase fire danger and threaten native species","docAbstract":"Scientists examine this exotic grass invasion that threatens to alter the fire regime in the Sonoran Desert and the composition, structure, and function of protected ecosystems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Park Science","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"07359462","usgsCitation":"Esque, T., Schwalbe, C., Lissow, J., Haines, D., Foster, D., and Garnet, M., 2006, Buffelgrass fuel loads in Saguaro National Park, Arizona, increase fire danger and threaten native species: Park Science, v. 24, no. 2.","costCenters":[],"links":[{"id":236499,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f2a3e4b0c8380cd4b280","contributors":{"authors":[{"text":"Esque, T. C. 0000-0002-4166-6234","orcid":"https://orcid.org/0000-0002-4166-6234","contributorId":76250,"corporation":false,"usgs":true,"family":"Esque","given":"T. C.","affiliations":[],"preferred":false,"id":418619,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schwalbe, C.R.","contributorId":35259,"corporation":false,"usgs":false,"family":"Schwalbe","given":"C.R.","email":"","affiliations":[],"preferred":false,"id":418617,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lissow, J.A.","contributorId":92854,"corporation":false,"usgs":true,"family":"Lissow","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":418621,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Haines, D.F.","contributorId":80602,"corporation":false,"usgs":true,"family":"Haines","given":"D.F.","email":"","affiliations":[],"preferred":false,"id":418620,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Foster, D.","contributorId":36892,"corporation":false,"usgs":true,"family":"Foster","given":"D.","email":"","affiliations":[],"preferred":false,"id":418618,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Garnet, M.C.","contributorId":18558,"corporation":false,"usgs":true,"family":"Garnet","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":418616,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028644,"text":"70028644 - 2006 - Inhibition of coral recruitment by macroalgae and cyanobacteria","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70028644","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2663,"text":"Marine Ecology Progress Series","active":true,"publicationSubtype":{"id":10}},"title":"Inhibition of coral recruitment by macroalgae and cyanobacteria","docAbstract":"Coral recruitment is a key process in the maintenance and recovery of coral reef ecosystems. While intense competition between coral and algae is often assumed on reefs that have undergone phase shifts from coral to algal dominance, data examining the competitive interactions involved, particularly during the larval and immediate post-settlement stage, are scarce. Using a series of field and outdoor seawater table experiments, we tested the hypothesis that common species of macroalgae and cyanobacteria inhibit coral recruitment. We examined the effects of Lyngbya spp., Dictyota spp., Lobophora variegata (J. V. Lamouroux) Womersley, and Chondrophycus poiteaui (J. V. Lamouroux) Nam (formerly Laurencia poiteaui) on the recruitment success of Porites astreoides larvae. All species but C. poiteaui caused either recruitment inhibition or avoidance behavior in P. astreoides larvae, while L. confervoides and D. menstrualis significantly increased mortality rates of P. astreoides recruits. We also tested the effect of some of these macrophytes on larvae of the gorgonian octocoral Briareum asbestinum. Exposure to Lyngbya majuscula reduced survival and recruitment in the octocoral larvae. Our results provide evidence that algae and cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. On reefs experiencing phase shifts or temporary algal blooms, the restocking of adult coral populations may be slowed due to recruitment inhibition, thereby perpetuating reduced coral cover and limiting coral community recovery. ?? Inter-Research 2006.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Ecology Progress Series","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.3354/meps323107","issn":"01718630","usgsCitation":"Kuffner, I., Walters, L., Becerro, M., Paul, V., Ritson-Williams, R., and Beach, K., 2006, Inhibition of coral recruitment by macroalgae and cyanobacteria: Marine Ecology Progress Series, v. 323, p. 107-117, https://doi.org/10.3354/meps323107.","startPage":"107","endPage":"117","numberOfPages":"11","costCenters":[],"links":[{"id":477687,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://doi.org/10.3354/meps323107","text":"External Repository"},{"id":209842,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.3354/meps323107"},{"id":236573,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"323","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3bd7e4b0c8380cd62878","contributors":{"authors":[{"text":"Kuffner, I. B.","contributorId":40328,"corporation":false,"usgs":true,"family":"Kuffner","given":"I. B.","affiliations":[],"preferred":false,"id":418996,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Walters, L.J.","contributorId":107081,"corporation":false,"usgs":true,"family":"Walters","given":"L.J.","email":"","affiliations":[],"preferred":false,"id":418999,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Becerro, M.A.","contributorId":18956,"corporation":false,"usgs":true,"family":"Becerro","given":"M.A.","affiliations":[],"preferred":false,"id":418994,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Paul, V.J.","contributorId":40782,"corporation":false,"usgs":true,"family":"Paul","given":"V.J.","email":"","affiliations":[],"preferred":false,"id":418997,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ritson-Williams, R.","contributorId":88546,"corporation":false,"usgs":true,"family":"Ritson-Williams","given":"R.","affiliations":[],"preferred":false,"id":418998,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Beach, K.S.","contributorId":37134,"corporation":false,"usgs":true,"family":"Beach","given":"K.S.","email":"","affiliations":[],"preferred":false,"id":418995,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028636,"text":"70028636 - 2006 - Occurrence and fate of organic contaminants during onsite wastewater treatment","interactions":[],"lastModifiedDate":"2018-10-26T08:48:33","indexId":"70028636","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Occurrence and fate of organic contaminants during onsite wastewater treatment","docAbstract":"Onsite wastewater treatment systems serve approximately 25% of the U.S. population. However, little is known regarding the occurrence and fate of organic wastewater contaminants (OWCs), including endocrine disrupting compounds, during onsite treatment. A range of OWCs including surfactant metabolites, steroids, stimulants, metal-chelating agents, disinfectants, antimicrobial agents, and pharmaceutical compounds was quantified in wastewater from 30 onsite treatment systems in Summit and Jefferson Counties, CO. The onsite systems represent a range of residential and nonresidential sources. Eighty eight percent of the 24 target compounds were detected in one or more samples, and several compounds were detected in every wastewater sampled. The wastewater matrices were complex and showed unique differences between source types due to differences in water and consumer product use. Nonresidential sources generally had more OWCs at higher concentrations than residential sources. Additional aerobic biofilter-based treatment beyond the traditional anaerobic tank-based treatment enhanced removal for many OWCs. Removal mechanisms included volatilization, biotransformation, and sorption with efficiencies from <1% to >99% depending on treatment type and physico chemical properties of the compound. Even with high removal rates during confined unit onsite treatment, OWCs are discharged to soil dispersal units at loadings up to 20 mg/m2/d, emphasizing the importance of understanding removal mechanisms and efficiencies in onsite treatment systems that discharge to the soil and water environments.
Near-field observations of high-precision borehole strain and pore pressure, show no indication of coherent accelerating strain or pore pressure during the weeks to seconds before the 28 September 2004 M 6.0 Parkfield earthquake. Minor changes in strain rate did occur at a few sites during the last 24 hr before the earthquake but these changes are neither significant nor have the form expected for strain during slip coalescence initiating fault failure. Seconds before the event, strain is stable at the 10−11 level. Final prerupture nucleation slip in the hypocentral region is constrained to have a moment less than 2 × 1012 N m (M 2.2) and a source size less than 30 m. Ground displacement data indicate similar constraints. Localized rupture nucleation and runaway precludes useful prediction of damaging earthquakes. Coseismic dynamic strains of about 10 microstrain peak-to-peak were superimposed on volumetric strain offsets of about 0.5 microstrain to the northwest of the epicenter and about 0.2 microstrain to the southeast of the epicenter, consistent with right lateral slip. Observed strain and Global Positioning System (gps) offsets can be simply fit with 20 cm of slip between 4 and 10 km on a 20-km segment of the fault north of Gold Hill (M0 = 7 × 1017 N m). Variable slip inversion models using gps data and seismic data indicate similar moments. Observed postseismic strain is 60% to 300% of the coseismic strain, indicating incomplete release of accumulated strain. No measurable change in fault zone compliance preceding or following the earthquake is indicated by stable earth tidal response. No indications of strain change accompany nonvolcanic tremor events reported prior to and following the earthquake.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/0120050822","issn":"00371106","usgsCitation":"Johnston, M., Borcherdt, R., Linde, A.T., and Gladwin, M.T., 2006, Continuous borehole strain and pore pressure in the near field of the 28 September 2004 M 6.0 Parkfield, California, earthquake: Implications for nucleation, fault response, earthquake prediction and tremor: Bulletin of the Seismological Society of America, v. 96, no. 4B, p. S56-S72, https://doi.org/10.1785/0120050822.","productDescription":"17 p.","startPage":"S56","endPage":"S72","costCenters":[{"id":234,"text":"Earthquake Hazards Program","active":true,"usgs":true}],"links":[{"id":236500,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","city":"Parkfield","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -120.73905944824217,\n 35.69187929931617\n ],\n [\n -120.16227722167967,\n 35.69187929931617\n ],\n [\n -120.16227722167967,\n 36.05964632692448\n ],\n [\n -120.73905944824217,\n 36.05964632692448\n ],\n [\n -120.73905944824217,\n 35.69187929931617\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"96","issue":"4B","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fa5ae4b0c8380cd4da74","contributors":{"authors":[{"text":"Johnston, M.J.S. 0000-0003-4326-8368","orcid":"https://orcid.org/0000-0003-4326-8368","contributorId":104889,"corporation":false,"usgs":true,"family":"Johnston","given":"M.J.S.","affiliations":[],"preferred":false,"id":418625,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Borcherdt, R. D. 0000-0002-8668-0849","orcid":"https://orcid.org/0000-0002-8668-0849","contributorId":32165,"corporation":false,"usgs":true,"family":"Borcherdt","given":"R. D.","affiliations":[],"preferred":false,"id":418624,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Linde, A. T.","contributorId":21700,"corporation":false,"usgs":true,"family":"Linde","given":"A.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":418622,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gladwin, M. T.","contributorId":30373,"corporation":false,"usgs":true,"family":"Gladwin","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":418623,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70028568,"text":"70028568 - 2006 - Predicting tree species presence and basal area in Utah: A comparison of stochastic gradient boosting, generalized additive models, and tree-based methods","interactions":[],"lastModifiedDate":"2012-03-12T17:20:58","indexId":"70028568","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1458,"text":"Ecological Modelling","active":true,"publicationSubtype":{"id":10}},"title":"Predicting tree species presence and basal area in Utah: A comparison of stochastic gradient boosting, generalized additive models, and tree-based methods","docAbstract":"Many efforts are underway to produce broad-scale forest attribute maps by modelling forest class and structure variables collected in forest inventories as functions of satellite-based and biophysical information. Typically, variants of classification and regression trees implemented in Rulequest's?? See5 and Cubist (for binary and continuous responses, respectively) are the tools of choice in many of these applications. These tools are widely used in large remote sensing applications, but are not easily interpretable, do not have ties with survey estimation methods, and use proprietary unpublished algorithms. Consequently, three alternative modelling techniques were compared for mapping presence and basal area of 13 species located in the mountain ranges of Utah, USA. The modelling techniques compared included the widely used See5/Cubist, generalized additive models (GAMs), and stochastic gradient boosting (SGB). Model performance was evaluated using independent test data sets. Evaluation criteria for mapping species presence included specificity, sensitivity, Kappa, and area under the curve (AUC). Evaluation criteria for the continuous basal area variables included correlation and relative mean squared error. For predicting species presence (setting thresholds to maximize Kappa), SGB had higher values for the majority of the species for specificity and Kappa, while GAMs had higher values for the majority of the species for sensitivity. In evaluating resultant AUC values, GAM and/or SGB models had significantly better results than the See5 models where significant differences could be detected between models. For nine out of 13 species, basal area prediction results for all modelling techniques were poor (correlations less than 0.5 and relative mean squared errors greater than 0.8), but SGB provided the most stable predictions in these instances. SGB and Cubist performed equally well for modelling basal area for three species with moderate prediction success, while all three modelling tools produced comparably good predictions (correlation of 0.68 and relative mean squared error of 0.56) for one species. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Modelling","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.ecolmodel.2006.05.021","issn":"03043800","usgsCitation":"Moisen, G.G., Freeman, E., Blackard, J., Frescino, T., Zimmermann, N., and Edwards, T., 2006, Predicting tree species presence and basal area in Utah: A comparison of stochastic gradient boosting, generalized additive models, and tree-based methods: Ecological Modelling, v. 199, no. 2, p. 176-187, https://doi.org/10.1016/j.ecolmodel.2006.05.021.","startPage":"176","endPage":"187","numberOfPages":"12","costCenters":[],"links":[{"id":209810,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.ecolmodel.2006.05.021"},{"id":236533,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"199","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a81dde4b0c8380cd7b798","contributors":{"authors":[{"text":"Moisen, Gretchen G.","contributorId":15781,"corporation":false,"usgs":false,"family":"Moisen","given":"Gretchen","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":418643,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Freeman, E.A.","contributorId":80885,"corporation":false,"usgs":true,"family":"Freeman","given":"E.A.","email":"","affiliations":[],"preferred":false,"id":418646,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Blackard, J.A.","contributorId":103060,"corporation":false,"usgs":true,"family":"Blackard","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":418648,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Frescino, T.S.","contributorId":94485,"corporation":false,"usgs":true,"family":"Frescino","given":"T.S.","email":"","affiliations":[],"preferred":false,"id":418647,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zimmermann, N.E.","contributorId":24547,"corporation":false,"usgs":true,"family":"Zimmermann","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":418644,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Edwards, T.C. Jr. 0000-0002-0773-0909","orcid":"https://orcid.org/0000-0002-0773-0909","contributorId":76486,"corporation":false,"usgs":true,"family":"Edwards","given":"T.C.","suffix":"Jr.","affiliations":[],"preferred":false,"id":418645,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028571,"text":"70028571 - 2006 - Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations","interactions":[],"lastModifiedDate":"2018-10-29T09:14:40","indexId":"70028571","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2233,"text":"Journal of Contaminant Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Tracer test with As(V) under variable redox conditions controlling arsenic transport in the presence of elevated ferrous iron concentrations","docAbstract":"To study transport and reactions of arsenic under field conditions, a small-scale tracer test was performed in an anoxic, iron-reducing zone of a sandy aquifer at the USGS research site on Cape Cod, Massachusetts, USA. For four weeks, a stream of groundwater with added As(V) (6.7 μM) and bromide (1.6 mM), was injected in order to observe the reduction of As(V) to As(III). Breakthrough of bromide (Br−), As(V), and As(III) as well as additional parameters characterizing the geochemical conditions was observed at various locations downstream of the injection well over a period of 104 days. After a short lag period, nitrate and dissolved oxygen from the injectate oxidized ferrous iron and As(V) became bound to the freshly formed hydrous iron oxides. Approximately one week after terminating the injection, anoxic conditions had been reestablished and increases in As(III) concentrations were observed within 1 m of the injection. During the observation period, As(III) and As(V) were transported to a distance of 4.5 m downgradient indicating significant retardation by sorption processes for both species. Sediment assays as well as elevated concentrations of hydrogen reflected the presence of As(V) reducing microorganisms. Thus, microbial As(V) reduction was thought to be one major process driving the release of As(III) during the tracer test in the Cape Cod aquifer.