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Success of stream restoration can be difficult to define because many interacting abiotic and biotic factors across spatio‐temporal scales can have measurable effects. Consequently, failure in habitat restoration to achieve targeted biological goals may reflect interactions of habitat restoration with unaccounted risks that have yet to be addressed on the landscape. This is particularly true within invaded landscapes, where habitat restoration can benefit non‐native competitors as much as the native fishes for which restoration is designed. We tested for interacting effects of a reach scale habitat restoration effort and non‐native trout competition on habitat use by a brook trout (Salvelinus fontinalis) metapopulation within a productive main stem corridor of the Shavers Fork watershed, West Virginia. We used a joint species occupancy model within a BACI sampling design to show that brook trout occupancy of main stem habitat was highest post‐restoration within restored sampling reaches, but this benefit to native brook trout was conditional on brown trout (Salmo trutta) not being present within the main stem habitat. Collectively these results indicate that habitat restoration was only beneficial for native brook trout when non‐native trout were absent from the restored sampling area. Proactive approaches to restoration will be integral for supporting resilient ecosystems in response to future anthropogenic threats (e.g. climate change), and we have shown that such actions will only be successful if non‐native competitors do not also benefit from the restoration actions. [ABSTRACT FROM AUTHOR]

We quantified stream temperature response to in‐stream habitat restoration designed to improve thermal suitability and resiliency of a high‐elevation Appalachian stream known to support a temperature‐limited brook trout population. Our specific objectives were to determine if: (1) construction of deep pools created channel unit‐scale thermal refugia and (2) reach scale stream channel reconfiguration reduced peak water temperatures along a longitudinal continuum known to be highly susceptible to summer‐time warming. Contrary to expectations, constructed pools did not significantly decrease channel unit‐scale summer water temperatures relative to paired control sites. This suggests that constructed pools did not successfully intercept a cool groundwater source. However, we did find a significant effect of stream channel restoration on reach‐scale thermal regimes. Both mean and maximum daily stream temperatures experienced significantly reduced warming trends in restored sections relative to control sections. Furthermore, we found that restoration efforts had the greatest effect on stream temperatures downstream of large tributaries. Restoration appears to have significantly altered thermal regimes within upper Shavers Fork, largely in response to changes in channel morphology that facilitated water movement below major cold‐water inputs. Decreased longitudinal warming will likely increase the thermal resiliency of the Shavers Fork main‐stem, sustaining the ability of these key large river habitats to continue supporting critical metapopulation processes (e.g. supplemental foraging and dispersal among tributary populations) in the face of climate change. [ABSTRACT FROM AUTHOR]

We used direct observation via snorkeling surveys to quantify microhabitat use by native brook (Salvelinus fontinalis) and non‐native brown (Salmo trutta) and rainbow (Onchorynchus mykiss) trout occupying natural and restored pool habitats within a large, high‐elevation Appalachian river, United States. Permutational multivariate analysis of variance (PERMANOVA) and subsequent two‐way analysis of variance (ANOVA) indicated a significant difference in microhabitat use by brook and non‐native trout within restored pools. We also detected a significant difference in microhabitat use by brook trout occupying pools in allopatry versus those occupying pools in sympatry with non‐native trout—a pattern that appears to be modulated by size. Smaller brook trout often occupied pools in the absence of non‐native species, where they used shallower and faster focal habitats. Larger brook trout occupied pools with, and utilized similar focal habitats (i.e. deeper, slower velocity) as, non‐native trout. Non‐native trout consistently occupied more thermally suitable microhabitats closer to cover as compared to brook trout, including the use of thermal refugia (i.e. ambient–focal temperature >2°C). These results suggest that non‐native trout influence brook trout use of restored habitats by: (1) displacing smaller brook trout from restored pools, and (2) displacing small and large brook trout from optimal microhabitats (cooler, deeper, and lower velocity). Consequently, benefits of habitat restoration in large rivers may only be fully realized by brook trout in the absence of non‐native species. Future research within this and other large river systems should characterize brook trout response to stream restoration following removal of non‐native species. [ABSTRACT FROM AUTHOR]

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As pointed out in this lead article, stock repurchasing has grown greatly in importance during the past two decades and now represents a significant and well-recognized force in the capital markets. Recent large-scale repurchasing by Gulf Oil Corp. and IBM have highlighted and brought additional attention to this phenomenon. In general (although there are instances of the practice being abused), repurchasing can be of significant economic value to society as firms with financial resources beyond the needs of the high-yielding capital investment projects available to them repurchase their equity securities and thus pump funds into the marketplace. The capital allocation process is therefore aided as investors, whose shares have been repurchased, reinvest these funds in securities which they feel have greater growth prospects as reflected in the issuing corporation having available a multitude of high-yielding capital investment projects. Repurchasing can thus add to the fluidity of the capital allocation process by providing an orderly means by which funds in the hands of firms with excess capital and a paucity of high-yielding capital investment projects become redirected through the marketplace toward firms needing capital and having planned high-yielding capital-intensive investment projects. The importance and potential benefits of repurchasing have brought forth a number of efforts at studying various aspects of this phenomenon. This article looks at the market reaction to a share repurchase through a tender offer and draws implications for both the corporate financial manager and the investor. [ABSTRACT FROM AUTHOR]

The first spectroscopic study of the diatomic radical BC is reported which confirms previous theoretical predictions of a 4∑- electronic ground state. The nuclear hyperfine interactions (A tensors) obtained for 11B, 10B, and 13C from the electron spin resonance (ESR) measurements are compared with extensive ab initio CI calculations. The BC molecule is one of the first examples of a small high spin radical for such an in-depth experimental–theoretical comparison. The electronic structure of BC obtained from an analysis of the nuclear hyperfine interaction (hfi) is compared to that obtained from a Mulliken-type population analysis conducted on a CI wave function which yields Aiso and Adip results in good agreement with the observed values. The BC radical was generated by the laser vaporization of a boron–carbon mixture and trapped in neon, argon, and krypton matrices at 4 K for a complete ESR characterization. The magnetic parameters (MHz) obtained for 11B13C in solid neon are: g|| =2.0015(3); g⊥ =2.0020(3); D(zfs)=1701(2); 11B: |A||| =100(1); |A⊥| =79(1); 13C: |A||| =5(2) and |A⊥| =15(1). Based on comparison with the theoretical results, the most likely choice of signs is that all A values are positive. [ABSTRACT FROM AUTHOR]

The 12C31P and 13C31P diatomic radicals have been generated by the laser vaporization reaction between carbon and phosphorus which were pressed into a pellet to form the laser target. This method is applicable to a wide range of nonmetallic systems for generating new reactive intermediates which cannot be done with more conventional approaches. The radicals were isolated in neon and argon matrices at 4 K for detailed ESR investigations. The magnetic parameters (MHz) for neon were: g||=2.0009(3); g⊥=1.9902(3); A||(31P)=145.0(3); A⊥(31P)=-269.0(2); A||(13C)=580.0(3); and A⊥(13C)=422.0(3). The argon A and g tensors were virtually indistinguishable from these neon results. Extensive ab initio theoretical calculations were conducted for CP which yielded nuclear hyperfine A values in close agreement with the experimental results. Valence orbital spin populations extracted from the calculated CI wave functions are compared with those determined directly from the ESR hyperfine parameters for 13C and 31P. The observed g shift for CP agreed with the gas phase spin–rotation constant and indicates the presence of a low lying 2πr state that has not been previously observed. [ABSTRACT FROM AUTHOR]

Assessments of watershed-based restoration efforts are rare but are essential for the science of stream restoration to advance. We conducted a watershed scale assessment of Abram Creek before and after implementation of a watershed-based plan designed to maximize ecological recovery from acid mine drainage (AMD) impairment. We surveyed water chemistry, physical habitat, benthic macroinvertebrates, and fish community structure in three stream types: AMD-impacted (14 streams), AMD-treated (13 streams), and unimpaired reference (4 streams). We used in-stream measurements to quantify ecological loss from AMD, the amount of ecological recovery expected through remediation, and the observed degree of post-treatment recovery. Sites impaired by AMD improved in water quality with AMD treatment. Dissolved metals and acidity declined significantly in treated streams, but sulfate and specific conductance did not. Likewise, sites impaired by AMD improved in bio-condition scores with AMD treatment. EPT genera increased significantly but were lower compared to unimpaired streams. We found fish at nine treated sites that had none before treatment. Community-level analyses indicated improved but altered assemblages with AMD treatment. Analysis of pre-treatment conditions indicated that only 30% of the historic fishery remained. Remediation was expected to recover 66% of the historic fishery value, and assessment of post-treatment conditions indicates that 52% of the historic fishery has been recovered after 3 years. Developing expected endpoints for restoration outcomes provides a tool to objectively evaluate successes and can guide adaptive management strategies. [ABSTRACT FROM AUTHOR]

Coldwater fishes in streams, such as brook trout ( Salvelinus fontinalis), typically are headwater specialists that occasionally expand distributions downstream to larger water bodies. It is unclear, however, whether larger streams function simply as dispersal corridors connecting headwater subpopulations, or as critical foraging habitat needed to sustain large mobile brook trout. Stable isotopes (δC and δN) and a hierarchical Bayesian mixing model analysis was used to identify brook trout that foraged in main stem versus headwater streams of the Shavers Fork watershed, West Virginia. Headwater subpopulations were composed of headwater and to a lesser extent main stem foraging individuals. However, there was a strong relationship between brook trout size and main stem prey contributions. The average brook trout foraging on headwater prey were limited to 126 mm standard length. This size was identified by mixing models as a point where productivity support switched from headwater to main stem dependency. These results, similar to other studies conducted in this watershed, support the hypothesis that productive main stem habitat maintain large brook trout and potentially facilitates dispersal among headwater subpopulations. Consequently, loss of supplementary main stem foraging habitats may explain loss of large, mobile fish and subsequent isolation of headwater subpopulations in other central Appalachian watersheds. [ABSTRACT FROM AUTHOR]

Runoff from watersheds altered by mountaintop mining in the Appalachian region (USA) is known to pollute headwater streams, yet regional-scale assessments of water quality have focused on salinization and selenium. The authors conducted a comprehensive survey of inorganic contaminants found in 170 stream segments distributed across a spectrum of historic and contemporary human land use. Principal component analysis identified 3 important dimensions of variation in water chemistry that were significantly correlated with contemporary surface mining (principal component 1: elevated dominant ions, sulfate, alkalinity, and selenium), coal geology and legacy mines (principal component 2: elevated trace metals), and residential development (principal component 3: elevated sodium and chloride). The combination of these 3 dominant sources of pollutants produced a complex stream-to-stream patchwork of contaminant mixtures. Seventy-five percent of headwater streams (catchments < 5 km2) had water chemistries that could be classified as either reference (49%), development only (18%), or mining only (8%). Only 21% of larger streams (catchments > 5 km2) were classified as having reference chemistries, and chemistries indicative of combined mining and development contaminants accounted for 47% of larger streams (compared with 26% of headwater streams). Extreme degradation of larger streams can be attributed to accumulation of contaminants from multiple human land use activities that include contemporary mountaintop mining, underground mining, abandoned mines, and untreated domestic wastewater. Consequently, water quality improvements in this region will require a multicontaminant remediation approach. Environ Toxicol Chem 2015;34:2603-2610. © 2015 SETAC [ABSTRACT FROM AUTHOR]

We conducted a survey of 170 streams distributed throughout the mountaintop-mining region of West Virginia (USA) and linked stream data to a temporally consistent and comprehensive land-cover data set. We then applied a generalized linear modeling framework and constructed cumulative effects models capable of predicting in-stream response to future surface-mine development within the context of other landuse activities. Predictive models provided precise estimates of specific conductance (model R2 ≤ 0.77 and cross-validated R2 ≤ 0.74), Se (0.74 and 0.70), and benthic macroinvertebrate community composition (0.72 and 0.65). Deletion tests supported the conclusion that stream degradation across the region is the result of complex, but predictable, additive and interactive effects of surface mining, underground mining, and residential development. Furthermore, we found that as stressors other than surface mining are factored out completely, the surface-mining level that results in exceedance of the 300 μS/cm conductivity benchmark increased from 4.4% in the presence of other stressors to 16.6% when only surface mining was present. Last, extrapolating model results to all unsampled stream segments in the region (n = 26,135), we predicted high levels of chemical (33%) and biological (67%) impairment to streams on the current landscape. Of this total impairment, however, <25% could be attributed to surface mining alone. These results underscore the importance of multistressor landuse models for reliable predictions of stream conditions, and the difficulty of interpreting correlations between surface mining and stream impairment without fully accounting for other landuse activities. [ABSTRACT FROM AUTHOR]

Brook trout ( Salvelinus fontinalis) often exist as highly differentiated populations, even at small spatial scales, due either to natural or anthropogenic sources of isolation and low rates of dispersal. In this study, we used molecular approaches to describe the unique population structure of brook trout inhabiting the Shavers Fork watershed, located in eastern West Virginia, and contrast it to nearby populations in tributaries of the upper Greenbrier River and North Fork South Branch Potomac Rivers. Bayesian and maximum likelihood clustering methods identified minimal population structuring among 14 collections of brook trout from throughout the mainstem and tributaries of Shavers Fork, highlighting the role of the cold-water mainstem for connectivity and high rates of effective migration among tributaries. In contrast, the Potomac and Greenbrier River collections displayed distinct levels of population differentiation among tributaries, presumably resulting from tributary isolation by warm-water mainstems. Our results highlight the importance of protecting and restoring cold-water mainstem habitats as part of region-wide brook trout conservation efforts. In addition, our results from Shavers Fork provide a contrast to previous genetic studies that characterize Appalachian brook trout as fragmented isolates rather than well-mixed populations. Additional study is needed to determine whether the existence of brook trout as genetically similar populations among tributaries is truly unique and whether connectivity among brook trout populations can potentially be restored within other central Appalachian watersheds. [ABSTRACT FROM AUTHOR]

The article examines that the effects of a practically implemented exercise programme on self-directed exercise behavior. It also assesses vital health outcomes in people with multiple sclerosis (PwMS) to nine months of follow-up. 120 PwMS were included in the study who underwent a parallel-arm, randomized controlled trial.

The article examines the cost effectiveness of a pragmatic exercise intervention (EXIMS) in multiple sclerosis (MS) patients. Although, exercise is a safe, non-pharmacological adjunctive treatment for MS patients, cost effective approaches within health care settings are needed. A total of 120 MS patients were included in the study.

We tested the hypothesis that brook trout growth rates are controlled by a complex interaction of food availability, water temperature, and competitor density. We quantified trout diet, growth, and consumption in small headwater tributaries characterized as cold with low food and high trout density, larger tributaries characterized as cold with moderate food and moderate trout density, and large main stems characterized as warm with high food and low trout density. Brook trout consumption was highest in the main stem where diets shifted from insects in headwaters to fishes and crayfish in larger streams. Despite high water temperatures, trout growth rates also were consistently highest in the main stem, likely due to competitively dominant trout monopolizing thermal refugia. Temporal changes in trout density had a direct negative effect on brook trout growth rates. Our results suggest that competition for food constrains brook trout growth in small streams, but access to thermal refugia in productive main stem habitats enables dominant trout to supplement growth at a watershed scale. Brook trout conservation in this region should seek to relieve the 'temperature-productivity squeeze,' whereby brook trout productivity is constrained by access to habitats that provide both suitable water temperature and sufficient prey. [ABSTRACT FROM AUTHOR]

Spatial population models predict strong density-dependence and relatively stable population dynamics near the core of a species' distribution with increasing variance and importance of density-independent processes operating towards the population periphery. Using a 10-year data set and an information-theoretic approach, we tested a series of candidate models considering density-dependent and density-independent controls on brook trout population dynamics across a core-periphery distribution gradient within a central Appalachian watershed. We sampled seven sub-populations with study sites ranging in drainage area from 1.3–60 km2 and long-term average densities ranging from 0.335–0.006 trout/m. Modeled response variables included per capita population growth rate of young-of-the-year, adult, and total brook trout. We also quantified a stock-recruitment relationship for the headwater population and coefficients of variability in mean trout density for all sub-populations over time. Density-dependent regulation was prevalent throughout the study area regardless of stream size. However, density-independent temperature models carried substantial weight and likely reflect the effect of year-to-year variability in water temperature on trout dispersal between cold tributaries and warm main stems. Estimated adult carrying capacities decreased exponentially with increasing stream size from 0.24 trout/m in headwaters to 0.005 trout/m in the main stem. Finally, temporal variance in brook trout population size was lowest in the high-density headwater population, tended to peak in mid-sized streams and declined slightly in the largest streams with the lowest densities. Our results provide support for the hypothesis that local density-dependent processes have a strong control on brook trout dynamics across the entire distribution gradient. However, the mechanisms of regulation likely shift from competition for limited food and space in headwater streams to competition for thermal refugia in larger main stems. It also is likely that source-sink dynamics and dispersal from small headwater habitats may partially influence brook trout population dynamics in the main stem. [ABSTRACT FROM AUTHOR]

Mountaintop removal-valley fill mining results in the conversion of steep, forested headwater catchments to low gradient and open canopy channels. We compared the ecological functions of five reference stream channels to five constructed channels (age ranging from 3 to 20 years) on reclaimed mines in southern West Virginia. Variables included stream flow, habitat, water chemistry, riparian vegetation, organic matter (OM) processing, and invertebrate and amphibian communities. Although dissolved metal concentrations remained low, constructed channels produced significantly higher levels of conductivity and total dissolved solids as compared to reference streams. Macroinvertebrate and amphibian richness were comparable between constructed and reference channels; however, there was a distinct shift from sensitive lotic taxa in reference channels to tolerant lentic taxa in constructed channels. Constructed channels also had reduced OM decomposition rates. Nevertheless, constructed channels had significantly higher OM retention than reference channels, and consequently exhibited significantly higher overall OM processing and higher dissolved carbon concentrations. As the time since reclamation increased, we observed slight declines in conductivity and significant increases in total invertebrate richness. Our results provide measures of functional equivalencies between reference and constructed streams, which can serve as a basis for informed permitting and mitigation decisions in mined watersheds. [ABSTRACT FROM AUTHOR]

Scenario analysis has the potential to improve management of aquatic systems throughout the Mountaintop Removal-Valley Fill mining (MTR-VF) region of central Appalachia. However, the extent to which surface mining interacts with other landuse stressors (i.e., cumulative effects) is unclear, and this limits our ability to predict the effects of new mines on physical, chemical, and biological conditions downstream. We tested for additive and interactive effects of landuse change (surface mining, deep mining, and residential development) on water quality (specific conductance and Se), habitat quality, and benthic macroinvertebrates via a uniquely designed watershed-scale assessment of the Coal River, West Virginia (USA). We derived equations for predicting in-stream response to landscape changes and predicted the outcome of a realistic future scenario involving development of 15 permitted mines. Elevated Se concentrations were directly correlated with incremental increases in surface-mining extent. Surface mining, deep mining, and residential development had additive effects on elevated specific conductance and reduced biological condition. We found evidence of a positive interactive effect (stressor antagonism) of deep mining and residential development on biological condition, presumably caused by stream-flow augmentation from deep mines. Landscape context influenced predicted impacts from construction of 15 new mines because of additive and interactive effects of landuse change. New surface mines increased the number of receiving streams exceeding chemical and biological criteria, but a greater proportion of receiving streams exceeded chemical and biological criteria at equivalent levels of new mine development when pre-existing stressors were present. When surface mining was the only stressor, ≥30 or 40% increases in surface mining caused 100% of streams to exceed chemical or biological standards, respectively, whereas in streams stressed by deep mining and residential development, ≥10% additional surface mining caused 100% of streams to exceed chemical and biological standards. Continued progress in this area will require a better understanding of how landuse change affects aquatic systems in the rest of the MTR-VF mining region, where watershed-to-watershed variation in landuse patterns probably causes variability in ecological response. [ABSTRACT FROM AUTHOR]

Despite improved understanding of how aquatic organisms are influenced by environmental conditions at multiple scales, we lack a coherent multiscale approach for establishing stream conservation priorities in active coal-mining regions. We classified watershed conditions at 3 hierarchical spatial scales, following a house-neighborhood-community approach, where houses (stream segments) are embedded within neighborhoods (Hydrologic Unit Code [HUC]-12 watersheds) embedded within communities (HUC-10 watersheds). We used this information to develop a framework to prioritize restoration and protection in two HUC-8 watersheds in an intensively mined region of the central Appalachians. We used landscape data to predict current conditions (water chemistry and macroinvertebrate biotic integrity) for all stream segments with boosted regression tree (BRT) analysis. Mining intensity, distance to mining, and coal type were the dominant predictors of water quality and biological integrity. A hardness-salinity dimension of the water-chemistry data was explained by land-cover features and stream elevation. We compiled segment-level conditions to the HUC-12 and HUC-10 watershed scales to represent aquatic resource conditions hierarchically across 3 watershed-management scales. This process enabled us to relate stream-segment watershed conditions to watershed conditions in the broader context, and ultimately to identify key protection and restoration priorities in a metacommunity context. Our hierarchical classification system explicitly identifies stream restoration and protection priorities within a HUC-12 watershed context, which ensures that the benefits of restoration will extend beyond the stream reach. Highest protection priorities are high-quality HUC-12 watersheds adjacent to low-quality HUC-12 watersheds. Highest restoration priorities are HUC-12 watersheds in poor-fair condition within HUC-10 watersheds of good-excellent condition, whereas lowest restoration priorities are isolated HUC-12 watersheds. In high-priority HUC-12 watersheds, stream segments with the highest restoration priority are those that maximize watershed-scale restorability. A similar process for classifying conditions and restoration priorities may be valuable in other heavily impacted regions where strategic approaches are needed to maximize watershed-scale recovery. [ABSTRACT FROM AUTHOR]

We quantified movements of brook trout Salvelinus fontinalis and brown trout Salmo trutta in a complex riverscape characterized by a large, open-canopy main stem and a small, closed-canopy tributary in eastern West Virginia, USA. Our objectives were to quantify the overall rate of trout movement and relate movement behaviors to variation in streamflow, water temperature, and access to coldwater refugia. The study area experienced extremely high seasonal, yearly, and among-stream variability in water temperature and flow. The relative mobility of brook trout within the upper Shavers Fork watershed varied significantly depending on whether individuals resided within the larger main stem or the smaller tributary. The movement rate of trout inhabiting the main stem during summer months (50 m/d) was an order of magnitude higher than that of tributary fish (2 m/d). Movement rates of main-stem-resident brook trout during summer were correlated with the maximum water temperature experienced by the fish and with the fish's initial distance from a known coldwater source. For main-stem trout, use of microhabitats closer to cover was higher during extremely warm periods than during cooler periods; use of microhabitats closer to cover during warm periods was also greater for main-stem trout than for tributary inhabitants. Main-stem-resident trout were never observed in water exceeding 19.5°C. Our study provides some of the first data on brook trout movements in a large Appalachian river system and underscores the importance of managing trout fisheries in a riverscape context. Brook trout conservation in this region will depend on restoration and protection of coldwater refugia in larger river main stems as well as removal of barriers to trout movement near tributary and main-stem confluences. Received September 16, 2011; accepted March 23, 2012 [ABSTRACT FROM PUBLISHER]

Global climate change has received increased attention in the Mid-Atlantic Highlands (MAH) Region of the United States in recent years. Several climate models predict increases in mean temperature of 1-5°C over the next one hundred years for the region, which has considerable implications for wetland ecosystems already encumbered by numerous anthropogenic stressors; however, historical (i.e., 1890s-current) data from the MAH presented here show increasing trends in precipitation intensity and decreasing trends in temperature. Continuation of historical trends for the next 90 years are used to predict potential impacts on regional wetland extent and function using empirical and conceptual models. Recommendations for management of climate related impacts on wetlands include analysis of historical climate trends at regional and local scales, establishment of wetland monitoring networks to quantify impacts of climate induced stress on wetland ecosystems, and integration of historical trends and research findings into empirical and conceptual models. Management strategies of this nature will facilitate early detection and mitigation of climate induced effects on wetlands in the MAH. [ABSTRACT FROM AUTHOR]

Throughout the Central Appalachians of the United States resource extraction primarily from coal mining has contributed to the majority of the forest conversion to barren and reclaimed pasture and grass. The loss of forests in this ecoregion is significantly impacting biodiversity at a regional scale. Since not all forest stands provide equal levels of ecological functions, it is critical to identify and map existing forested resources by the benefits that accrue from their unique spatial patterns, watershed drainage, and landscape positions. We utilized spatial analysis and remote sensing techniques to define critical forest characteristics. The characteristics were defined by applying a forest fragmentation model utilizing morphological image analysis, defining headwater catchments at a 1 : 24,000 scale, and deriving ecological land units (ELUs) from elevation data. Once critical forest values were calculated, it was possible to identify clusters of critical stands using spatial statistics. This spatially explicit method for modeling forest habitat could be implemented as a tool for assessing the impact of resource extraction and aid in the conservation of critical forest habitat throughout a landscape. [ABSTRACT FROM AUTHOR]

The current study focuses on mothers and fathers of children with three rare genetic syndromes that are relatively unexplored in terms of family experience: Angelman syndrome, Cornelia de Lange syndrome and Cri du Chat syndrome. Parents of children with Angelman syndrome ( n = 15), Cornelia de Lange syndrome ( n = 16) and Cri du Chat syndrome ( n = 18), and a matched comparison group of parents of children with autism and intellectual disabilities ( n = 20) completed questionnaires on both psychological distress (stress, anxiety, depression) and positive psychological functioning. Parents of children with Angelman syndrome consistently reported the highest levels of psychological distress, and parents of children with Cornelia de Lange syndrome the lowest, with parents of children with Cri du Chat syndrome and autism scoring between these two. Positive psychological functioning was similar across the four aetiology groups. Parents of children with rare genetic syndromes are at risk for high levels of stress and mental health problems. Methodological issues and the practical applications of these results are discussed. [ABSTRACT FROM AUTHOR]

As watershed-scale studies of stream fishes become increasingly common, there is a need for more accurate estimation of fish population abundance and size structure with single-pass electrofishing techniques. Capture efficiencies are known to vary considerably across habitats and species, yet few studies have quantified or provided a logical framework for accounting for this variability. Consequently, our objectives were to (1) determine which species and which size-classes within species exhibited significant site-to-site variation in electrofishing efficiency and (2) construct models to predict species- and size-specific capture probability from physicochemical parameters. We used three-pass removal sampling to capture fishes from 40 study sites located in wadeable streams in the Cheat River and Tygart Valley River watersheds of West Virginia. The program MARK was used to estimate capture probabilities for 12 commonly sampled fishes, to assess among-site variability in capture probability, and to model variability in capture probability as a function of fish size and readily measured environmental covariates. Our results indicated that for most species sampled (9 of 12), some combination of these covariates-mean stream width, gradient, specific conductivity, and species size-class-could be used to produce a model of capture probability superior to the most complex model that accounted for site-to-site variability in capture probability. One species demonstrated constant capture probability among sites, and two others exhibited significant site-to-site variation in capture probability that could not be accounted for using any of the measured covariates. Our results provide a basis for using single-pass electrofishing data to infer population-level phenomena (e.g., relative abundance, size structure) in watershed-scale studies of stream fish assemblages. [ABSTRACT FROM AUTHOR]

1. We used information theoretic statistics [Akaike’s Information Criterion (AIC)] and regression analysis in a multiple hypothesis testing approach to assess the processes capable of explaining long-term demographic variation in a lightly exploited brook trout population in Ball Creek, NC. We sampled a 100-m-long second-order site during both spring and autumn 1991–2004, using three-pass electrofishing. 2. Principle component analysis indicated that the site had lower average velocity, greater amounts of depositional substrata and lower amount of erosional substrata during the 1999–2002 drought than in non-drought years. In addition, drought years had lower flows, and lower variation in flows, than non-drought years. 3. Both young-of-the-year (YOY) and adult densities varied by an order of magnitude during the study. AIC analysis conducted on regressions of per capita rate of increase versus various population and habitat parameters for the population, adults and YOY, for both spring and autumn data sets, indicated that simple density dependence almost always was the only interpretable model with Akaike weights ( wi) ranging from 0.262 to 0.836. 4. Growth analyses yielded more variable results, with simple density dependence being the only interpretable model for both adult spring data ( wi = 0.999) and YOY autumn data ( wi = 0.905), and positive density dependence ( wi = 0.636) and simple density independence ( wi = 0.241) representing interpretable models for spring YOY data. 5. We detected a significant stock–recruitment relationship between both spring and autumn densities of adults in year t and autumn YOY density in year t + 1. Finally, spring YOY density was positively correlated with both autumn YOY density and spring mean YOY standard length (SL), suggesting that processes affecting recruitment show residual effects at least in the first year of life. This population appears to be regulated primarily by density-dependent processes, although high flows also negatively affected mean SLs of YOY. [ABSTRACT FROM AUTHOR]

1. We used observational and experimental field studies together with an individual-based simulation model to demonstrate that behaviours of mottled sculpin ( Cottus bairdi) were broadly consistent with the expectations of Giving-Up Density theory and an Ideal Pre-emptive Distribution habitat selection model. 2. Specifically we found that: (i) adult mottled sculpin established territories within patches characterised by significantly higher prey densities and prey renewal rates than patches occupied by juveniles or randomly selected patches; (ii) patches abandoned by adult sculpin possessed significantly lower prey densities than newly occupied patches, although this was not true for juveniles; (iii) the observed giving-up density (GUD) for adult sculpin (i.e. average prey density in patches recently abandoned) increased linearly with increasing fish size up to the average prey density measured in randomly selected patches (i.e. 350 prey items per 0.1 m2) and decreased with increasing sculpin density and (iv) juveniles rapidly shifted their distribution towards the highest quality patches following removal of competitively dominant adult sculpin. 3. These results provide the first evidence of the applicability of GUD theory to a stream-dwelling organism, and they elucidate the underlying factors influencing juvenile and adult sculpin habitat selection and movement behaviours. Furthermore, optimal patch use, ideal pre-emptive habitat selection and juvenile ‘floating’ provide behavioural mechanisms linking environmental heterogeneity in the stream benthos to density-dependent regulation of mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]

We developed and validated a predictive model of water temperature that could be applied to mapped stream segments in a West Virginia, USA watershed. We then tested the hypothesis that local water temperature and the topology of stream thermal networks interact to determine the distribution of two fishes known to differ in their thermal preference - smallmouth bass (Micropterus dolomieu) and brook trout (Salvelinus fontinalis). Two measures of regional thermal topology were constructed -- mean distance to the nearest five coldwater stream segments and distance to the nearest warmwater stream segment. Consistent with expectations, brook trout were more likely to be found in colder streams, and smallmouth bass were in wanner streams. However, brook trout distributions were statistically independent of the regional thermal context suggesting that regional thermal conditions have less influence on brook trout than local thermal conditions in this system. In contrast, there was a significant effect of stream network topology on the distribution of smallmouth bass. Bass were often present in coolwater streams located in close proximity to warmwater mainstems but not in coolwater streams highly isolated from warm water. Furthermore, sympatry in these two species was associated with cool- and coldwater streams located in close proximity to warmwater streams. These findings indicate that overall fish assemblage response to thermal conditions may be the result of species-specific responses to both local thermal conditions and the regional topology of cold, cool, and warmwater streams. [ABSTRACT FROM AUTHOR]

Large-scale culvert replacement programs could benefit migratory fish populations by reconnecting reproductive and foraging habitats in fragmented watersheds. The objectives of this study were to: (1) identify stream and culvert characteristics contributing to fish passage barriers within an Appalachian watershed, U.S.A.; (2) quantify the total amount of Brook trout ( Salvelinus fontinalis) reproductive habitat isolated above culverts; and (3) use an ecological currency to identify culvert replacement priorities and stream mitigation credit opportunities. We surveyed 120 state-owned culverts and used a fish passage assessment filter to determine the “passability” of each culvert. We then constructed a geographic information system stream network model to quantify the amount of trout reproductive habitat isolated by culverts. Ninety-seven percent of surveyed culverts were classified as obstacles or complete barriers to trout dispersal. Culvert impassability was higher in small streams with slopes exceeding 3–5%, suggesting a direct relationship between slope and impassability. Thirty-three percent of Brook trout reproductive habitat, representing over 200 km of stream, was isolated by culverts. This is a conservative estimate, because we did not survey privately or federally owned culverts. The top 20 prioritized culverts accounted for nearly half of the habitat loss. Our results indicate that standard culvert designs placed in streams with slopes exceeding 5% consistently produce trout dispersal barriers and should be avoided during new road construction. The process developed here provides an efficient method for identifying culvert replacement priorities and may be used to maximize watershed scale benefits of stream restoration. [ABSTRACT FROM AUTHOR]

Hypoxia in tumours has been associated with an increased resistance to radiation and chemotherapy, and increased metastatic potential. Hypoxia-inducible factor 1-α (HIF-1α) is a transcription factor induced by hypoxia. Glucose transporter 1 (GLUT-1), a downstream product of HIF-1α pathway activation, is over-expressed in a variety of human tumours. The purpose of this study was to determine if GLUT-1 is expressed in canine osteosarcomas (OSAs) and if the expression is related to tumour necrosis and outcome. Immunohistochemistry was performed on 44 histologically confirmed OSA tissue samples to assess expression of GLUT-1. Of 44 cases, 27 (61%) expressed GLUT-1. There was no statistical correlation between GLUT-1 and disease-free interval, survival time or percentage of necrosis. As hypothesized, GLUT-1 is present in canine appendicular OSAs. A more objective evaluation of GLUT-1 and other proteins in the HIF-1α pathway may be warranted. [ABSTRACT FROM AUTHOR]

Salamanders are important members of faunal communities in Appalachian Mountain (USA) streams, and the use of salamanders as bioindicators is increasing. Roads are a part of the modern landscape, but effects of roads on stream and streamside salamander diversity and abundance is not clear. We sampled streams in central West Virginia, USA, using quadrats placed along transects in the flowing channel, dry channel, and stream bank to assess salamander diversity, richness, and abundance during 2004. We used Akaike's Information Criterion for model selection at reach (i.e., above and below culverts) and stream scales. Salamander diversity and richness was affected by elevation, stream gradient, canopy cover, and the presence of roads. Overall, stream and riparian habitat quality was the most important factor affecting salamander richness. The presence of roads, stream gradient, and elevation received the most empirical support for predicting species' abundances. Roads benefited disturbance-tolerant species but negatively affected other species. Impacts of roads and culverts on habitat should be considered by federal and state transportation agencies and natural resources agencies during the planning process and addressed through mitigation efforts. Managers should install culverts that are as wide as the stream channel, at grade with the streambed, and dominated by rubble substrate to provide maximum benefit for salamanders. [ABSTRACT FROM AUTHOR]

We quantified the space use behaviors of juvenile and adult mottled sculpin over a 3-year period in Shope Fork, western North Carolina. Our objectives were to (1) quantify home range size, (2) determine whether the fish exhibit territorial behaviors, (3) characterize the relative stability of territories, and (4) relate temporal variation in behaviors to environmental variability and population size structure. Adult behaviors were consistent with those of a strongly territorial organism. Adults exhibited nonrandom movements, restricted home ranges, and extremely low levels of spatial overlap with neighboring residents (<10% overlap). Territories were established in erosional microhabitats that were significantly more stable (as measured by seasonal shifts in dominant substrate composition) than randomly selected microhabitats in the study site. In contrast to adults, juveniles did not exhibit evidence of territoriality and instead occupied overlapping home ranges (16-36% overlap) in less-stable, depositional microhabitats along the stream margin. Mottled sculpin home range size, home range overlap, and territory abandonment rate were related to the density of large adults rather than flow variability or microhabitat stability. Adult territoriality and juvenile floating provide behavioral mechanisms capable of producing strong regulation of mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]

We analyzed seasonal water samples from the Cheat and Tygart Valley river basins, West Virginia, USA, in an attempt to classify streams based on water chemistry in this coal-mining region. We also examined temporal variability among water samples. Principal component analysis identified two important dimensions of variation in water chemistry. This variation was determined largely by mining-related factors (elevated metals, sulfates, and conductivity) and an alkalinity-hardness gradient. Cluster analysis grouped water samples into six types that we described as reference, soft, hard, transitional, moderate acid mine drainage, and severe acid mine drainage. These types were statistically distinguishable in multidimensional space. Classification tree analysis confirmed that chemical constituents related to acid mine drainage and acid rain distinguished these six groups. Hard, soft, and severe acid mine drainage type streams were temporally constant compared to streams identified as reference, transitional, and moderate acid mine drainage type, which had a greater tendency to shift to a different water type between seasons. Our research is the first to establish a statistically supported stream classification system in mined watersheds. The results suggest that human-related stressors superimposed on geology are responsible for producing distinct water quality types in this region as opposed to more continuous variation in chemistry that would be expected in an unimpacted setting. These findings provide a basis for simplifying stream monitoring efforts, developing generalized remediation strategies, and identifying specific remediation priorities in mined Appalachian watersheds. [ABSTRACT FROM AUTHOR]

The article discusses a research on the response of stream ecosystem to the limestone treatment in watersheds that were affected by acid in the Allegheny Plateau of West Virginia, USA. A study is conducted to assess the remediation programs of acid precipitation in streams in the plateau. The examination involved the sampling of water chemistry, physical habitat, periphyton biomass and fish community structure in streams that are acidic and acidic streams treated with limestone sand. The research revealed that the application of limestone sand to acidic streams was effective in fully recovering some characteristics, such as trout biomass, density and reproductive process.

Multimetric indices based on fish and benthic macroinvertebrate assemblages are commonly used to assess the biological integrity of aquatic ecosystems. However, their response to specific stressors is rarely known. We quantified the response of a fish-based index (Mid-Atlantic Highlands Index of Biotic Integrity, MAH-IBI) and a benthic invertebrate-based index (West Virginia Stream Condition Index, WV-SCI) to acid mine drainage (AMD)-related stressors in 46 stream sites within the Cheat River watershed, West Virginia. We also identified specific stressor concentrations at which biological impairment was always or never observed. Water chemistry was extremely variable among tributaries of the Cheat River, and the WV-SCI was highly responsive across a range of AMD stressor levels. Furthermore, impairment to macroinvertebrate communities was observed at relatively low stressor concentrations, especially when compared to state water quality standards. In contrast to the WV-SCI, we found that the MAH-IBI was significantly less responsive to local water quality conditions. Low fish diversity was observed in several streams that possessed relatively good water quality. This pattern was especially pronounced in highly degraded subwatersheds, suggesting that regional conditions may have a strong influence on fish assemblages in this system. Our results indicate that biomonitoring programs in mined watersheds should include both benthic invertebrates, which are consistent indicators of local conditions, and fishes, which may be indicators of regional conditions. In addition, remediation programs must address the full suite of chemical constituents in AMD and focus on improving linkages among streams within drainage networks to ensure recovery of invertebrate and fish assemblages. Future research should identify the precise chemical conditions necessary to maintain biological integrity in mined Appalachian watersheds. [ABSTRACT FROM AUTHOR]

We surveyed benthic macroinvertebrate communities, water chemistry, and thermal regime in the Cheat River, WV, USA in an attempt to quantify the interactive effects of multiple stressors on ecological condition and identify priorities for restoration in this mined Appalachian watershed. We used a novel approach, which combined use of the West Virginia Stream Condition Index (WVSCI) to quantify ecological losses and community similarity analysis to assign specific levels of ecological loss to AMD, thermal effluent, and their interaction. Finally, we developed an ecological currency to quantify the relative benefits of a restoration program that focused either on AMD remediation or heat reduction and to identify spatially explicit restoration priorities. Variation in ecological condition was strongly correlated to variation in water quality when AMD and heat stress occurred in isolation. Acute inputs of AMD or heat caused predictable reductions in condition followed by rapid recovery downstream. However, benthic communities failed to recover from combined inputs of heat and AMD even when these stressors occurred at relatively low levels. Over the course of an entire year, AMD alone was over two times more responsible than heat alone for ecological loss. Consequently, AMD is the dominant factor limiting ecological condition and should be the primary target for restoration. Nevertheless, an AMD × heat interaction also was responsible for extensive ecological loss in lower reaches of the river. Consequently, full restoration of the lower Cheat River mainstem will require an approach that integrates AMD remediation with effective management of thermal effluent. Our results provide some of the first field evidence of the interactive effects of multiple stressors on biological communities in a mined watershed. This approach may be valuable for quantifying impacts from multiple interacting stressors and for prioritizing restoration efforts in other mined watersheds. [ABSTRACT FROM AUTHOR]

We used strong inference with Akaike's Information Criterion (AIC) to assess the processes capable of explaining long-term (1984-1995) variation in the per capita rate of change of mottled sculpin (Cottus bairdi) populations in the Coweeta Creek drainage (USA). We sampled two fourth- and one fifth-order sites (BCA [uppermost], BCB, and CC [lowermost]) along a downstream gradient, and the study encompassed extensive flow variation. Physical habitat availability varied significantly both within and among the sites. Sculpin densities in all sites were highly stable (coefficients of variation = 0.23-0.41) and sampling variability was low (coefficients of variation = 0.11-0.15). Population stability was positively associated with habitat stability, and the only significant correlations of population parameters among sites involved juveniles. Sculpin densities were significantly higher in BCB than in CC. The data suggest that, despite their proximity, the dynamics of populations within the sites are being determined by small-scale (i.e., 30-50 m) rather than broad-scale spatial processes. Both AIC and Dennis and Taper analyses indicated that simple density dependence had the greatest ability to explain variation in r for all life-history classes in all sites (AIC, seven of nine cases; Dennis and Taper, nine of nine cases). Multiprocess models had little explanatory power. When adults were removed from two sites, juvenile sculpin shifted into microhabitats formerly occupied by adults. No shifts occurred in control sites. Consequently, it is likely that the patterns of density dependence observed in all three sites were a consequence of intraspecific competition for space. Our findings argue for a multitiered approach to the study of population variation, one that encompasses long-term monitoring, spatial variation, and experimental testing of potential mechanisms. [ABSTRACT FROM AUTHOR]

This study offers a theoretical framework of ethical behavior and a comparative analysis of ethical perceptions of managers of large, mostly publicly traded corporations (those with 1,000 or more employees) and the owners and managers of smaller companies (those with fewer than 100 employees) across 17 years. The primary research provides basic data on the changing standards of ethics as perceived by leaders of large and small businesses where the cultures frequently fall into sharp contrast. Our findings reveal the extent to which the message of business integrity is gaining or losing ground within large and small companies. It does this by means of respondents’ judgments of acceptable responses to 16 scenarios profiling common business situations with questionable ethical dimensions. Based on responses from over 5,000 managers and employees (from firms of all sizes) to our scenarios at three points in time (1985, 1993, 2001), we tested two research questions. First, for firms of all sizes, have business ethics improved or declined between the years 1985 and 2001? Second, comparing responses of large and small firm executives across the 1985–2001 time frame, is there a discernible difference in their ethical standards? Our results suggest that business leaders are making somewhat more ethical decisions in recent years. We also found that small business owner–managers offered less ethical responses to scenarios in 1993 but that no significant differences existed with large firm managers in 1985 and 2001. Implications of our findings are discussed. [ABSTRACT FROM AUTHOR]

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The extent of impairment to some Appalachian watersheds from acid precipitation is so extreme that watershed scale analytical tools are needed to help guide cost-effective management decisions. The objective of this study was to develop a measure of the functional value of streams as potential areas for juvenile Brook trout recruitment. This measure, which we term“weighted potential recruitment area” (WPRA), is a function of the expected Brook trout spawning intensity and juvenile survivorship. Estimates of WPRA for each stream segment were then used to identify restoration priorities and optimal restoration programs in the upper Shavers Fork watershed in West Virginia, U.S.A. Using this approach, we determined that the watershed has lost nearly 80% of its historic juvenile recruitment potential as a result of acid precipitation. We also determined that of the 145 stream segments in the watershed, eight critical stream segments account for nearly 20% of the loss. The costs and ecological benefits of a series of five alternative restoration programs were then assessed using an ArcGIS model (Environmental Systems Research Institute, Redlands, CA, U.S.A.). This approach identified two“optimal” alternatives: (1) a low-cost, moderate-benefit approach that would use existing rail access to treat acidification in three critical headwater locations and (2) a high-cost, high-benefit approach that would use aerial limestone application to treat numerous acidic tributaries near their source. The measure of stream ecological value that we developed was effective in identifying critical restoration priorities and optimal restoration strategies in this watershed. A similar procedure could be used to guide watershed restoration decisions throughout the Appalachian region. [ABSTRACT FROM AUTHOR]

We quantified the watershed-scale spatial population dynamics of brook trout in the Second Fork, a third-order tributary of Shavers Fork in eastern West Virginia. We used visual surveys, electrofishing, and mark-recapture techniques to quantify brook trout spawning intensity, population density, size structure, and demographic rates (apparent survival and immigration) throughout the watershed. Our analyses produced the following results. Spawning by brook trout was concentrated in streams with small basin areas (i.e., segments draining less than 3 km2), relatively high alkalinity (>10 mg CaCO3/L), and high amounts of instream cover. The spatial distribution of juvenile and small-adult brook trout within the watershed was relatively stable and was significantly correlated with spawning intensity. However, no such relationship was observed for large adults, which exhibited highly variable distribution patterns related to seasonally important habitat features, including instream cover, stream depth and width, and riparian canopy cover. Brook trout survival and immigration rates varied seasonally, spatially, and among size-classes. Differential survival and immigration tended to concentrate juveniles and small adults in small, alkaline streams, whereas dispersal tended to redistribute large adults at the watershed scale. Our results suggest that spatial and temporal variations in spawning, survival, and movement interact to determine the distribution, abundance, and size structure of brook trout populations at a watershed scale. These results underscore the importance of small tributaries for the persistence of brook trout in this watershed and the need to consider watershed-scale processes when designing management plans for Appalachian brook trout populations. [ABSTRACT FROM AUTHOR]

There has been limited empirical research into the environmental causes of self-injury in Cornelia de Lange syndrome. The present study examined the variability of self-injurious behaviour in Cornelia de Lange syndrome across environmental setting events. Additionally, the association between setting events and more specific environmental events was examined.A descriptive analysis of observational data on eight children with Cornelia de Lange syndrome aged between 4 and 14 years was carried out. The association between self-injurious behaviour and four environmental setting events and between specific environmental events and setting events was examined using established statistical methods for observational data.Seven out of eight of the participants showed at least one form of self-injurious behaviour that was associated with a particular setting event. The study also demonstrated that the relationship between setting events and environmental events is extremely variable across individuals.Self-injurious behaviour in some individuals with Cornelia de Lange syndrome is associated with environmental events although the precise nature of the association warrants clarification. Using broad setting events as a methodological tool in isolation provides some insight into the role of specific environmental factors in maintaining self-injurious behaviour but the integrity of setting events must be established. [ABSTRACT FROM AUTHOR]

The purpose of the research presented in this paper was twofold: (1) to demonstrate the coupling of two state-of- the-art techniques: a time-weighted polar organic chemical integrative sampler (POCIS) and micro liquid chromatography- electrospray/ion-trap mass spectrometry and (2) to assess the ability of these methodologies to detect six drugs (azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, methylenedioxymethamphetamine [MDMA]) in a real-world environment, e.g., waste water effluent. In the effluent from three wastewater treatment plants (WWTPs), azithromycin was detected at concentrations ranging from 15 to 66 ng/L, which is equivalent to a total annual release of 1 to 4 kg into receiving waters. Detected and confirmed in the effluent from two WWTPs were two illicit drugs, methamphetamine and MDMA, at 2 and 0.5 ng/L, respectively. Although the ecotoxicologic significance of drugs in environmental matrices, particularly water, has not been closely examined, it can only be surmised that these substances have the potential to adversely affect biota that are continuously exposed to them even at very low levels. The potential for chronic effects on human health is also unknown but of increasing concern because of the multi-use character of water, particularly in densely populated, arid areas. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The purpose of the study was to ascertain health sciences librarians' attitudes toward the Academy of Health Information Professionals (AHIP). SAMPLE: Systematic sampling was used to select 210 names from the list of members of the Midwest Chapter of the Medical Library Association. METHODS: A questionnaire containing open- and closed-ended questions was used to collect the data. RESULTS: A total of 135 usable questionnaires were returned. Of the respondents, 34.8% are members of the academy and most are at the senior or distinguished member levels. The academy gives them a sense of professionalism and helps them to keep current with new trends. The majority of participants (65.2%) are not members of the academy. Among the various reasons proffered are that neither institutions nor employers require it and that there is no obvious benefit to belonging to the academy. CONCLUSIONS: More research needs to be done with a larger sample size to determine the attitudes of health sciences librarians, nationwide, toward the academy. [ABSTRACT FROM AUTHOR]

1. We used direct observation and mark-recapture techniques to quantify movements by mottled sculpins (Cottus bairdi) in a 1 km segment of Shope Fork in western North Carolina. Our objectives were to: (i) quantify the overall rate of sculpin movement, (ii) assess variation in movement among years, individuals, and sculpin size classes, (iii) relate movement to variation in stream flow and population size structure, and (iv) quantify relationships between movement and individual growth rates. 2. Movements were very restricted: median and mean movement distances for all sculpin size classes over a 45 day period were 1.3 and 4.4 m respectively. Nevertheless, there was a high degree of intrapopulation and temporal variation in sculpin movement. Movement of juveniles increased with discharge and with the density of large adults. Movement by small and large adults was not influenced by stream flow, but large adults where more mobile when their own density was high. Finally, there were differences in the growth rates of mobile and sedentary sculpins. Mobile juveniles grew faster than sedentary individuals under conditions of low flow and high density of large adults, whereas adults exhibited the opposite pattern. 3. Our results support the hypothesis that juvenile movement and growth is influenced by both intraspecific interactions with adults and stream flow. In contrast, adult movement appears to be influenced by competitive interactions among residents for suitable space. The relationship between movement and growth may provide a negative feedback mechanism regulating mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]