bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevention of Hydrogen Embrittlement by Surface Films
Authors: Murray George T. 
Published: October 2009

In liquid or gaseous media, certain additives, called inhibitors, can occupy, via a strong binding energy to the base metal, atom sites on the metal surfaces, thus preventing a metal-hydrogen bond and thereby inhibiting the entry of hydrogen into the base metal. For both metallic and nonmetallic solid films, hydrogen entry can be prevented or reduced if the film has a lesser binding energy for hydrogen than the base metal and if a low solubility and/or a low diffusivity for hydrogen. Nonmetallic films appear to be the better films for preventing hydrogen entry and subsequent embrittlement of the base metal.
Data are presented for oxide and nitride films in the 50 to 3000-nm range of thickness. A 50-nm-thick film of sputtered alumina (A12O3) and a 3000-nm-thick, thermally grown oxide film appear to prevent hydrogen embrittlement in the precipitation-hardening stainless steels.
Increased risk of thyroid pathology in patients with thyroid hemiagenesis: results of a large cohort case–control study
Authors: Ruchala Marek , Szczepanek Ewelina , Szaflarski Witold , Moczko Jerzy , Czarnywojtek Agata , Pietz Leszek , Nowicki Michal , Niedziela Marek , Zabel Maciej , Köhrle Josef , Sowinski Jerzy 
Published: October 2009

ObjectiveThyroid hemiagenesis (THA) is an anomaly resulting from the developmental failure of one thyroid lobe. Etiopathogenesis, clinical significance, and management of patients in whom THA is diagnosed are still a matter of debate. The aim of the study is to provide the first systematic analysis of a large cohort of subjects with THA.DesignForty patients with THA are described in comparison to a control group of 80 subjects with fully developed thyroid gland.MethodsSerum concentrations of thyrotropin (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid autoantibodies were measured. In 37 patients, thyroid ultrasonography and Tc-99m thyroid scintiscan were performed, followed by fine-needle aspiration biopsy if indicated. The remaining archival three cases were diagnosed with the use of I-131 scintiscan under basal conditions and after TSH stimulation.ResultsPatients with THA, while usually clinically euthyroid, presented with significantly higher levels of TSH and FT3 as well as with higher FT3/FT4 concentration in comparison to the control group. Furthermore, a higher incidence of associated functional, morphological, and autoimmune thyroid disorders in patients with THA was observed when compared to subjects with bilobate thyroid (P<0.05).ConclusionsOur results revealed that individuals with THA are more likely to develop thyroid pathology. The observed high incidence of associated pathologies is presumably due to long-lasting TSH overstimulation. Therefore, THA diagnosis should be followed by systematic observation and adequate levothyroxine treatment in patients with elevated TSH level.
Ecotype Distinctions among Steelhead in Hood River, Oregon, Allow Real‐Time Genetic Assignment of Conservation Broodstocks
Authors: Matala A. P. , French R. , Olsen E. , Ardren W. R. 
Published: October 2009

AbstractEfforts to rehabilitate threatened summer‐run (SR) and winter‐run (WR) populations of steelhead Oncorhynchus mykiss in the Hood River, Oregon, include operation of two conservation hatchery programs. Annual collection of discrete broodstocks relies on identification of SR and WR fish based on return time, reproductive state, and other physical and behavioral characteristics. An increased likelihood of misidentification occurs in the spring, when SR and WR return times overlap. The resulting interbreeding between ecotypes in the hatchery imposes serious genetic risks to wild SR and WR steelhead populations. We characterized life history differences between Hood River SR and WR steelhead and evaluated genetic structure using a suite of microsatellite loci. Significant differences in life history, including age at return and fork length, were corroborated by spatially influenced genetic structure among SR and WR fish; SR fish spawn in the west fork of the Hood River, while WR fish spawn in the east and middle forks. Temporal and spatial distinctions persist among Hood River steelhead ecotypes despite past operation of segregated hatchery programs utilizing out‐of‐basin stocks. We evaluated the feasibility of using real‐time genetic assignment tests to differentiate SR from WR among candidate broodstock fish captured downstream of spawning grounds. Among adult steelhead of known origin, we observed 91.5% assignment accuracy for WR fish and 77.7% accuracy for SR fish. A rapid‐response protocol was subsequently developed that provides hatchery managers with genetic assignment of broodstock to ecotypes within 24 h after interrogation of returning fish.
Migration and Spawning of American Shad in the James River, Virginia
Authors: Aunins Aaron , Olney John E. 
Published: October 2009

AbstractAcoustic telemetry and ichthyoplankton surveys were used to characterize the migratory behavior and spawning grounds of American shad Alosa sapidissima in the James River, Virginia. Seven acoustic monitoring stations spanned a distance of 95 river kilometers extending downstream from just below the fall line in Richmond to the estuarine portion of the river at Hog Island. Ninety‐three fish were tagged in the estuarine portion of the river near Hog Island on 21 March 2005. Eighty‐six fish exhibited fallback behavior, and 45 of these fish eventually abandoned the migration. Forty‐six fish were eventually detected upstream at the mouths of the two major James River tributaries (Appomattox and Chickahominy rivers), within the main‐stem James River up to the fall line, or both. Upstream movements detected by stationary hydrophones during the prespawning migration were significantly related to flooding tides, and movements downstream during the postspawning emigration were significantly related to ebbing tides. However, there was no significant relationship between time of day and movements during the prespawning or postspawning migration phase. Movement patterns suggested three primary areas of residency located within the 65‐km reach below the fall line downstream to Upper Brandon Plantation, although some fish exhibited behaviors that were inconsistent with a specific residence area. Ichthyoplankton collections of eggs and yolk sac larvae indicated that the principal spawning grounds were located in a 33.5‐km reach extending downstream from the fall line, a finding consistent with repeated detection of a majority of the tagged cohort within this reach.
Influences of Wildfire, Habitat Size, and Connectivity on Trout in Headwater Streams Revealed by Patterns of Genetic Diversity
Authors: Neville Helen , Dunham Jason , Rosenberger Amanda , Umek John , Nelson Brooke 
Published: October 2009

AbstractWildfire is an important natural process in many stream ecosystems, but the ability of fish to respond to wildfire‐related disturbances is increasingly constrained by human activities that fragment and degrade stream habitats. In this study, we used molecular genetic markers (nuclear microsatellites) to examine the effects of wildfire and related disturbances along with habitat fragmentation on native rainbow trout in the Boise and Payette River basins, Idaho. We surveyed the genetic diversity of fish in 55 tributary streams to compare the level of diversity in samples without the recent influence of wildfire with that of those influenced by stand‐replacing wildfire and those influenced by both wildfire and a severe channel‐reorganizing disturbance. Stream habitats also varied substantially in size (catchment basin area) and isolation caused by road culverts. Based on prior work in our study streams, we expected that both wildfire and channel reorganization would reduce local population sizes significantly. Accordingly, we expected that wildfire‐related disturbances would reduce genetic diversity via founder effects or population bottlenecks. Our results, however, showed little evidence of these influences. In contrast, the level of genetic diversity was lower in fish collected upstream of culvert barriers, probably because of restricted gene flow. We also observed the expected positive correlation between habitat size and genetic diversity, which suggested the importance of larger local population sizes and habitat diversity in maintaining genetic diversity. An unexpected finding was that 15 of the 55 samples showed genetic evidence of hybridization between rainbow trout Oncorhynchus mykiss and nonnative cutthroat trout O. clarkii. The results of this study suggest that human influences such as barriers to dispersal and introductions of nonnative fish may pose greater threats to populations of native trout than wildfire itself.
Inferences on the Latent Mortality of Snake River Spring–Summer‐Run Chinook Salmon Using Spawner–Recruit Models
Authors: Hinrichsen Richard A. , Fisher Timothy R. 
Published: October 2009

AbstractThe rapid decline of the Snake River spring–summer‐run Chinook salmon Oncorhynchus tshawytscha evolutionarily significant unit (ESU) in the 1990s led a group of scientists to develop the Plan for Analyzing and Testing Hypotheses (PATH). Under this plan, researchers used spawner–recruit (SR) data to estimate the survival of out‐migrating smolts through eight dams of the Federal Columbia River Power System (FCRPS). Direct measurements of survival during out‐migration, known as passage survival, were not available, so the PATH scientists estimated survival for index populations using trends from Ricker‐type SR models. This modeling framework had the advantage of estimating both the direct and indirect (or latent) effects (FCRPS‐related mortalities that do not occur until the smolts have passed the FCRPS dams) on the life cycle survival of the populations. We evaluated the SR model used by the PATH scientists by examining how changes in model structure affected important inferences. We calculated condition indexes as measures of the sensitivity of the model results to perturbations in the SR data and model structure, finding that the results were highly sensitive to certain assumptions. In particular, we found that changing the Ricker α term from a population‐specific parameter to a parameter common to all of the populations in the ESU changed total passage survival from 9% to 56% and latent mortality from one‐half the total passage mortality to a value that is not significantly different from zero. Therefore, the condition indexes revealed high potential sensitivities of the SR model results to perturbations in data and model structure. Although information criteria indicated that the population‐specific model had a poorer fit than lower‐parameter models, it was impossible to resolve the question as to whether there was latent mortality.
A Statewide Assessment of Mercury Dynamics in North Carolina Water Bodies and Fish
Authors: Sackett Dana K. , Aday D. Derek , Rice James A. , Cope W. Gregory 
Published: October 2009

AbstractMercury contamination of aquatic systems has received much attention recently because of potential health effects on humans and wildlife. Although the factors affecting mercury deposition, its conversion to biologically active methylmercury, and its bioaccumulation in aquatic systems have been identified, equivocal results for particular species and systems have hampered policy making. Our study addresses this problem through a comprehensive, statewide synthesis of the available data on fish mercury contamination in North Carolina and the environmental factors associated with methylmercury formation and transport through aquatic food webs. Using data collected by the North Carolina Department of Environment and Natural Resources, the U.S. Environmental Protection Agency, and others, we examined the relationships between a suite of biotic and abiotic factors and tissue mercury concentrations in fish from North Carolina water bodies. Multivariate tests were conducted to create predictive models relating environmental variables to mercury levels in fish, and Akaike's information criterion was used to examine the relative strengths of the candidate models. The best model in our analyses (R2 = 0.81) included species, fish trophic status, ecoregion, and pH. Other important drivers of mercury accumulation were land use patterns (the percentage of the subbasin that is agricultural) and site type (swamps versus lakes, rivers, and bays). Although previous investigations have indicated similar individual relationships, our study is unique in that we examined the relative importance of a large number of biotic and abiotic variables across a range of environments, ecosystems, and species. The results of these analyses should help policymakers in making risk assessment decisions and serve as a template for future investigations.
Temperature and Flow Effects on Migration Timing of Chinook Salmon Smolts
Authors: Sykes Gregory E. , Johnson Chris J. , Shrimpton J. Mark 
Published: October 2009

AbstractPhysiological and behavioral changes occur in the spring when juvenile Pacific salmon Oncorhynchus spp. undergo smolting. Survival is maximized if the timing of these changes coincides with migration from fresh to marine environments. Therefore, understanding how environmental conditions influence the onset, duration, and termination of smolting can have substantial management implications, particularly for flow‐controlled rivers. We used an information‐theoretic model comparison analysis to investigate the roles of daily mean temperature, temperature experience (accumulated thermal units [ATU]), photoperiod, and flow on the timing of the downstream migration of Chinook salmon O. tshawytscha smolts from the Nechako River in central British Columbia. Both binary (migration or not) and count (the total number of migrants) models were developed that predicted the downstream migration of Chinook salmon based on data collected from fish captured at rotary‐screw traps from 1992 to 2004. The analyses identified a combination of temperature experience, flow, and the number of spawners as best able to describe the observed migration patterns. In addition, increasing ATU had a positive influence on migration, while increasing flow had a negative influence. Temperature experience was found to have more influence on migration than daily mean temperature. The predictive ability of each model was tested with 2 years of independent data. The count model accurately predicted the general trends in migration and, in particular, the termination of migration, but not the daily fluctuations in movement. By contrast, the binary model predicted whether fish would migrate on a given day with accuracies of 93% and 99%, respectively, for the 2 years tested. Temperature experience was more strongly linked to migration than the daily or threshold temperature; warmer temperatures resulted in earlier migration. Our data suggest that flow plays an important role once migration is under way and may even serve as a termination cue. Furthermore, the number of migrants and the probability of migration was positively related to the number of spawners. Based on the results of this study, flow manipulations that change the timing, duration, or magnitude of temperature and flow in the spring could affect the migration of Chinook salmon. Both temperature and river flow should be considered when one is managing flow‐controlled watersheds for salmon productivity.
Distribution and Migration of Juvenile Chinook Salmon Derived from Coded Wire Tag Recoveries along the Continental Shelf of Western North America
Authors: Trudel M. , Fisher J. , Orsi J. A. , Morris J. F. T. , Thiess M. E. , Sweeting R. M. , Hinton S. , Fergusson E. A. , Welch D. W. 
Published: October 2009

AbstractThe effects of ocean conditions on highly migratory species such as salmon are difficult to assess owing to the diversity of environments they encounter during their marine life. In this study, we reconstructed the initial ocean migration routes of juvenile Chinook salmonOncorhynchus tshawytschaoriginating from Oregon to Southeast Alaska using coded wire tag recovery data from Canadian Department of Fisheries and Oceans and National Marine Fisheries Service research surveys conducted between 1995 and 2006. Over this 12‐year period, 1,862 coded‐wire‐tagged juvenile Chinook salmon were recovered along the coasts of Oregon, Washington, British Columbia, and Alaska from March to November. Except for those from the Columbia River, most juvenile Chinook salmon remained within 100–200 km of their natal rivers until their second year at sea, irrespective of their freshwater history and adult run timing. Northward migration of most coastal stocks was initiated during their second or possibly third year at sea, whereas the Strait of Georgia and Puget Sound stocks primarily migrated onto the continental shelf after their first year at sea. In contrast, Columbia River Chinook salmon generally undertook a rapid northward migration that varied among life histories and stocks. Columbia River spring Chinook salmon were recovered as far north as Prince William Sound, Alaska, during their first summer at sea, whereas very few Columbia River fall Chinook salmon were recovered north of Vancouver Island. In addition to northern migrants, a fraction of the Columbia River spring and fall Chinook salmon actively migrated south of the Columbia River. The stock‐specific initial ocean migration routes described in this study will aid in the identification of the appropriate spatial and temporal scales for assessing the processes regulating Chinook salmon recruitment in the marine environment.
Seasonal Stock‐Specific Migrations of Juvenile Sockeye Salmon along the West Coast of North America: Implications for Growth
Authors: Tucker S. , Trudel M. , Welch D. W. , Candy J. R. , Morris J. F. T. , Thiess M. E. , Wallace C. , Teel D. J. , Crawford W. , Farley E. V. , Beacham T. D. 
Published: October 2009

AbstractKnowledge of the migratory habits of juvenile Pacific salmon Oncorhynchus spp. is required to test the hypothesis that ocean food resources are a limiting factor in their production. Using DNA stock identification techniques, we reconstructed the regional and seasonal changes in the stock composition of juvenile sockeye salmon O. nerka (n = 4,062) collected from coastal Washington to the Alaska Peninsula in coastal trawl surveys from May to February 1996–2007. Individuals were allocated to 14 regional populations. The majority were allocated to stocks from the Fraser River system (42%), while west coast Vancouver Island stocks accounted for 15% of the total catch; Nass and Skeena River sockeye salmon constituted 14% and Rivers Inlet 6% of the total. The remainder of the stocks identified individually contributed less than 5% of the sockeye salmon analyzed. These proportions generally reflected the abundance of those populations. In spring and summer, the majority of fish were caught in close proximity to their rivers of origin, lending further support to the allocations. By fall, sockeye salmon were caught as far north and west as the Alaska Peninsula, the majority being caught from central British Columbia to Southeast Alaska. Juvenile sockeye salmon generally disappeared from the coast by winter, suggesting dispersion into the Gulf of Alaska. Within each region, the proportional stock composition changed as the seasons progressed, with northward (and in some cases, rapid) migration along the coast. We also demonstrated stock‐specific differences in migration patterns. For each stock identified, body size and energy density were higher at northern latitudes, suggesting that there is an environmental or food web influence on growth or that faster growing fish initiated their northward migration earlier.
Diet, Movement, and Growth of Dolly Varden in Response to Sockeye Salmon Subsidies
Authors: Denton Keith P. , Rich Harry B. , Quinn Thomas P. 
Published: October 2009

AbstractA large and growing body of literature has documented the transfer of marine‐derived nutrients from the ocean to freshwater and riparian systems by semelparous Pacific salmon Oncorhynchus spp. The pathways by which these nutrients reach resident fish are often indirect, and the evidence for direct benefits to the resident fish is not always conclusive. However, the consumption of salmon tissue (in one form or another) by resident fish would constitute a direct and efficient pathway for energy transfer. We studied a population of small‐bodied, nonanadromous Dolly Varden Salvelinus malma feeding on the fry and eggs of sockeye salmon O. nerka and blowfly (family Calliphoridae) larvae that had fed on salmon carcasses at a series of spring‐fed and otherwise unproductive ponds in southwestern Alaska. The Dolly Varden fed heavily on sockeye salmon fry when available, shifted their diet almost exclusively to eggs after salmon spawning commenced, and then shifted to blowfly larvae toward the end of the season. Dolly Varden large enough to eat eggs moved into ponds where sockeye salmon spawn synchronously with the arrival of the salmon, and Dolly Varden growth rates increased greatly once salmon eggs and blowfly maggots were available. Young‐of‐the‐year Dolly Varden, which were too small to eat eggs and fry, were concentrated in small streams between ponds where fewer sockeye salmon spawn, perhaps to minimize the risk of predation from larger conspecifics. These results indicate the importance of a pulse of salmon‐related food resources for this population of resident fish and their adaptations to take advantage of these resources. It is likely that similar dependence occurs in other systems where sockeye salmon produce a suite of temporally predictable energy resources; thus, resident fish may depend on large populations of salmon.
Instrumentation von the Plover Cove Main Dam
Authors: Dunnicliff C. J. 
Published: October 2009

Synopsis Plover Cove main dam has been built in the sea to close the entrance to a bay, thereby forming a salt-water lake which has been pumped out and refilled with fresh water. The principal filling material is decomposed rock and, as this is the first instance von a major dam being built below water with such material, a high degree von instrumentation was considered desirable. The instrumentation and the installation procedures are described. A new type von settlement gauge developed for the project is described and typical measurements von pore pressure, settlement and horizontal movement are given. The Paper concludes with a summary von the cost von the instrumentation, which totalled about 2·1% von the cost von the dam. Le barrage principal de Plover Cove a été construit dans la mer pour fermer l'entrée présentée par une baie, formant ainsi un lac d'eau Salée qui a été vidé par pompage et rempli de nouveau d'eau douce. Le matériau de remblai principal est formé de roche décomposée et, comme c'est le premier exemple d'un barrage principal construit sous l'eau à l'aide d'un tel matériau, un très grand recours à des appareils fut considéré désirable. On décrit les appareils et les procédés d'installation. Une description est donnée d'un nouveau type de compteur de tassement, ainsi que des mesures typiques de la pression interstitielle, du tassement et du mouvement horizontal. L'Exposé termine avec un résumé sur le coût des appareils, qui représenta un total d'environ 2,1% du coût du barrage.