bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Stream Network‐Scale Variation in Coho Salmon Overwinter Survival and Smolt Size
Authors: Ebersole Joseph L. , Colvin Mike E. , Wigington Parker J. , Leibowitz Scott G. , Baker Joan P. , Church M. Robbins , Compton Jana E. , Miller Bruce A. , Cairns Michael A. , Hansen Bruce P. , La Vigne Henry R. 
Published: May 2009

AbstractWe used multiple regression and hierarchical mixed‐effects models to examine spatial patterns of overwinter survival and size at smolting in juvenile coho salmon Oncorhynchus kisutch in relation to habitat attributes across an extensive stream network in southwestern Oregon over 3 years. Contributing basin area explained the majority of spatial variation (R2 = 0.57‐0.63) in coho salmon overwinter survival (range = 0.02‐0.63), with highest survival rates observed in smaller headwater and intermittent streams. Other habitat attributes, including proportional pool area, percent exposed bedrock substrate, percent broadleaf canopy cover, and adult salmon carcass density, were relatively poor predictors of survival. Indices of individual fish condition, including fall parr fork length, condition factor, and parasite infestation rates, were also relatively uninformative in coho salmon overwinter survival models. Coho salmon smolt length was primarily a function of length at the time of fall tagging, but stream type, contributing basin area (positive effect), thermal history (positive effect), and black spot infestation (i.e., trematode metacercariae; negative effect) were also important. The consistent, broad spatial gradients in overwinter survival observed in this study can help guide efforts designed to enhance coho salmon production in coastal streams and suggest that habitat protection, restoration, and enhancement strategies will be best guided by a whole‐basin context.
Linking Habitat Quality with Trophic Performance of Steelhead along Forest Gradients in the South Fork Trinity River Watershed, California
Authors: McCarthy Sarah G. , Duda Jeffrey J. , Emlen John M. , Hodgson Garth R. , Beauchamp David A. 
Published: May 2009

AbstractWe examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low‐order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use bioenergetics modeling to determine the relative effects of forest cover, stream temperature, season, and fish age on food consumption and growth efficiency. Evidence of seasonal shifts in reliance on aquatic versus terrestrial food sources was detected among forest cover categories and fish ages, although these categories were not robust indicators of O. mykiss condition and growth efficiency. Consumption estimates were generally less than 20% of maximum consumption, and fish lost weight in some streams during summer low‐flow conditions when stream temperatures exceeded 15°C. Current 100‐year climate change projections for California threaten to exacerbate negative growth patterns and may undermine the productivity of this steelhead population, which is currently not listed as endangered or threatened. To demonstrate the potential effect of global warming on fish growth, we ran three climate change scenarios in two representative streams. Simulated temperature increases ranging from 1.4°C to 5.5°C during the summer and from 1.5°C to 2.9°C during the winter amplified the weight loss; estimated average growth for age‐1 fish was 0.4‐4.5 times lower than normal (low to high estimated temperature increase) in the warm stream and 0.05‐0.8 times lower in the cool stream. We conclude that feeding rate and temperature during the summer currently limit the growth and productivity of steelhead and rainbow trout in low‐order streams in the South Fork Trinity River basin and predict that climate change will have detrimental effects on steelhead growth as well as on macroinvertebrate communities and stream ecosystems in general.
Do Blue Crab Spawning Sanctuaries in North Carolina Protect the Spawning Stock
Authors: Eggleston David B. , Bell Geoffrey W. , Searcy Steven P. 
Published: May 2009

AbstractSpawning sanctuaries located at the five major inlets to Pamlico Sound, North Carolina, as well as various harvest controls, have not been adequate to protect the spawning stock of the blue crab Callinectes sapidus. We conducted an extensive trawl survey within Pamlico and Croatan sounds as well as five inlet spawning sanctuaries during 2002 to quantify the spatiotemporal use of spawning sanctuaries by mature female blue crabs and to identify potential migration corridors to spawning grounds. The abundance of mature females was highest along the northwestern portion of Pamlico Sound, suggesting this is an important staging area for females before their seaward migration; however, there was no clear evidence of specific migration corridors. Mature female abundance was no different inside inlet sanctuary boundaries versus 1‐2 km outside sanctuary boundaries, and sanctuaries only protect 44.9% and 0.7% of the current local inlet and Pamlico Sound‐wide spawning populations, respectively, of mature female blue crabs. In general, the abundance of mature female blue crabs was higher at inlets located to the extreme north or south in Pamlico Sound than at inlets located in the central portion of the sound. The results from this study suggest that the particular geometry and placement of inlet spawning sanctuaries are not adequate to protect the North Carolina blue crab spawning stock, and other management options should be considered, such as (1) a double sanctuary and migration corridor system located in northern and southern portions of Croatan and Pamlico sounds coupled with either (2) reduction of fishery effort on females or (3) seasonal closures.
Steelhead Life History on California's Central Coast: Insights from a State‐Dependent Model
Authors: Satterthwaite William H. , Beakes Michael P. , Collins Erin M. , Swank David R. , Merz Joseph E. , Titus Robert G. , Sogard Susan M. , Mangel Marc 
Published: May 2009

AbstractSteelheadOncorhynchus mykissdisplay a dizzying array of life history variation (including the purely resident form, rainbow trout). We developed a model for female steelhead in coastal California (close to the southern boundary of their range) in small coastal streams. We combined proximate (physiological) and ultimate (expected reproductive success) considerations to generalize the notion of a threshold size for emigration or maturity through the development of a state‐dependent life history theory. The model involves strategies that depend on age, size or condition, and recent rates of change in size or condition during specific periods (decision windows) in advance of the actual smolting or spawning event. This is the first study in which such a model is fully parameterized based on data collected entirely from California steelhead populations, the majority of data coming from two watersheds the mouths of whose rivers are separated by less than 8 km along the coast of Santa Cruz County. We predicted the occurrence of resident life histories and the distribution of sizes and ages at smolting for steelhead rearing in the upstream habitats of these streams. We compared these predictions with empirical results and show that the theory can explain the observed pattern and variation.
Seasonal Patterns of Abundance, Growth, and Site Fidelity of Juvenile Steelhead in a Small Coastal California Stream
Authors: Sogard Susan M. , Williams Thomas H. , Fish Heidi 
Published: May 2009

AbstractPopulations of steelheadOncorhynchus mykissthroughout the central California coast are currently listed as threatened under the federal Endangered Species Act. To better understand demographic processes during the juvenile freshwater stage, we quantified abundance, movement, and growth of juvenile steelhead among five reaches in a primary spawning area of Soquel Creek. We used mark‐recapture methods to examine seasonal, density‐dependent, and size‐dependent patterns in these population metrics. Many trends were stronger in age‐0 fish than in age‐1 and older fish. Estimated survival and retention within a reach were generally highest in summer and lowest in winter‐spring. Density dependence was evident only in age‐0 fish, with lower survival occurring at higher densities. Survival was typically size‐dependent, with lower survival of smaller fish in both age‐classes. Immigration, based on movement of untagged fish into our sites between sampling periods, was higher in winter‐spring compared with summer and fall. Immigration was generally independent of density but was size‐dependent, with smaller fish more likely to move than larger fish. Average growth rates were low, rarely exceeding 0.3 mm/d. Growth was fastest in winter‐spring, potentially a function of higher flow rates and increased food availability. Growth was generally size‐dependent, with smaller fish growing faster than larger fish. A negative effect of fish density on growth was apparent only for age‐0 fish in summer. High site fidelity was evident in high recapture rates of tagged fish. Recaptures over periods of up to 4 years suggested likely expression of a nonanadromous life history by some individuals. The growth rates in this system suggest that fish rearing in upstream habitats cannot undergo smoltification and emigrate until they are at least age 2. Our results provide a valuable baseline of demographic patterns for juvenile steelhead in representative freshwater habitat of the Central California Coast Steelhead Distinct Population Segment.
Pea (Pisum sativum) seed production as an assay for reproductive effects due to herbicides
Authors: Olszyk David , Pfleeger Thomas , Lee E. Henry , Plocher Milton 
Published: May 2009

AbstractEven though herbicide drift can affect plant reproduction, current plant testing protocols emphasize effects on vegetative growth. In this study, we determined whether a short-growing season plant can indicate potential effects of herbicides on seed production. Pea (Pisum sativum cv. Dakota) plants were grown in mineral soil in pots under greenhouse conditions. Plants were treated with a variety of herbicides (dicamba, clopyralid, glufosinate, glyphosate, 2-methyl-4-chlorophenoxyacetic acid, primisulfuron, or sulfometuron) at below standard field application rates applied at a vegetative stage of growth (∼14 d after emergence) or at flowering (∼20 d after emergence). Pea seed production was greatly reduced by sulfometuron at the minimum concentration used (0.001 × field application rate), with an effective concentration producing a 25% reduction in seed dry weight of 0.00007 × field application rate. Primisulfuron and glyphosate had a 25% reduction in seed dry weight for seed dry weight of 0.0035 and 0.0096 × field application rate, respectively. Clopyralid and dicamba reduced pea seed dry weight at a 25% reduction in seed dry weight of approximately 0.07 × field application rate. Glufosinate only reduced pea seed weight in one experiment, with a 25% reduction in seed dry weight of 0.07 and 0.008 × field application rate at vegetative growth and flowering stages, respectively. Pea seed dry weight was not affected by 2-methyl-4-chlorophenoxyacetic acid. Plant developmental stage had no consistent effect on herbicide responses. Reduced seed production occurred with some herbicides (especially acetolactate synthase inhibitors), which caused little or no reduction in plant height or shoot biomass and little visible injury. Thus, pea may be a model species to indicate seed reproductive responses to herbicides, with seed production obtained by extending plant growth for usually only 7 d longer than the period usually used in the vegetative vigor test.
Chemical and toxicological characterization of an unresolved complex mixture-rich biodegraded crude oil
Authors: Melbye Alf G. , Brakstad Odd G. , Hokstad Jorunn N. , Gregersen Inger K. , Hansen Bjørn H. , Booth Andy M. , Rowland Steven J. , Tollefsen Knut E. 
Published: May 2009

AbstractChemical and toxicological characterization of unresolved complex mixtures in the water-soluble fraction of an artificially weathered Norwegian Sea crude oil was determined by a combination of chemical analysis and toxicity testing in fish in vitro bioassays. The water-soluble fraction of the crude oil was separated into 14 increasingly polar fractions by preparative high-pressure liquid chromatography. The in vitro toxicity (7-ethoxyresorufin &lt;O-deethylase activity, estrogenicity, and metabolic inhibition) of these fractions was characterized in a primary culture of liver cells (hepatocytes) from rainbow trout (Oncorhynchus mykiss). The main contributor to toxicity was one of the most polar fractions, accounting gravimetrically for more than 70% of the organic material in the water-soluble fraction and dominated by an unresolved complex mixture. Chemical analysis by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography—time of flight—mass spectrometry identified a large number of cyclic and aromatic sulfoxide compounds and low amounts of benzothiophenes (&lt;0.1% of total mass) in this fraction. Commonly monitored toxic components of crude oil (e.g., naphthalenes, polycyclic aromatic hydrocarbons, and alkylated phenols) eluted in less polar fractions, characterized by somewhat lower toxicity. Normalization of in vitro responses to the mass in each fraction demonstrated a more even distribution of toxicity, indicating that toxicity in the individual fractions was related to the amount of material present. Although polar and nonpolar compounds contribute additively to crude oil toxicity, the water-soluble fraction was dominated by polar compounds because of their high aqueous solubility and the high oil—water loading. Under these conditions, the polar unresolved complex mixture—rich fraction might account for a large portion of crude oil toxicity because of its high abundance in the water-soluble fraction.
Instability transitions and ensemble equivalence in diffusive flow
Authors: Ha Meesoon 
Published: May 2009

Abstract
We investigate the critical behavior of one-dimensional (1D) stochastic flow with competing nonlocal and local hopping events, in context of the totally asymmetric simple exclusion process (TASEP) with a defect site in a 1D closed chain. The defect site can effectively generate various boundary conditions, controlling the total number of particles in the system. Both open and periodic-like setups exhibit dynamic instability transitions from a populated finite density phase to an empty road (ER) phase as the nonlocal hopping rate increases. In the stationary populated phase, strong clustering promoted by nonlocal skids drives such transitions and determines their scaling properties. By static and dynamic simulations, we locate such transition points, and discuss their nature and scaling properties. In the open TASEP variant, we numerically establish that the instability transition into the ER phase is second order in the regime where the entry point reservoir controls the current, while it is first order in the regime where the bulk controls the current. Since it is well known that such transitions are absent in the periodic TASEP variant, we compare our results in the open setup with those in the periodic-like setup, and discuss the issue of the ensemble equivalence. Finally, the same discussion is extended to the symmetric cases.
The effect of anastrozol on spatial memory in adult rats
Authors: Hodosy Július , Celec Peter , Ostatníková Daniela , Cagánová Marieta , Putz Zdeněk , Baláž Peter , Kúdela Matúš 
Published: May 2009

Abstract
Androgens are known to affect cognitive functions via organizational and activational effects. It is unknown whether the effects are mediated via the androgen receptor or after conversion to estradiol with aromatase via estrogen receptors. The aim of our study was to find out whether testosterone affects spatial memory directly or through its metabolite estradiol. Rats were treated with testosterone; with testosterone and the aromatase blocker anastrozole or saline. An 8 radial arm maze was used for testing spatial memory twice daily for 4 days. Each arm was baited with food, and the ability of animals to learn the location of food was assessed. Testosterone treated rats and control rats achieved comparable coefficients of spatial memory, although the plasma levels of testosterone differed markedly. Anastrozole treatment resulted in the worst performance in the maze. The differences between groups did not reach the level of significance. It can be concluded that aromatase and, thus, the conversion of testosterone to estradiol may play a role in spatial memory, as pharmacological blockade of aromatase led to a decrease in maze performace of adult male rats. Detailed molecular mechanisms should be the focus of further studies.
Ligand structure controlled allostery in cAMP-dependent protein kinase catalytic subunit
Authors: Kuznetsov Aleksei , Järv Jaak 
Published: May 2009

Abstract
Protein kinase A (cAMP dependent protein kinase catalytic subunit, EC 2.7.11.11) binds simultaneously ATP and a phosphorylatable peptide. These structurally dissimilar allosteric ligands influence the binding effectiveness of each other. The same situation is observed with substrate congeners, which reversibly inhibit the enzyme. In this review these allosteric effects are quantified using the interaction factor, which compares binding effectiveness of ligands with the free enzyme and the pre-loaded enzyme complex containing another ligand. This analysis revealed that the allosteric effect depends upon structure of the interacting ligands, and the principle “better binding: stronger allostery” observed can be formalized in terms of linear free-energy relationships, which point to similar mechanism of the allosteric interaction between the enzyme-bound substrates and/or inhibitor molecules. On the other hand, the type of effect is governed by ligand binding effectiveness and can be inverted from positive allostery to negative allostery if we move from effectively binding ligands to badly binding compounds. Thus the outcome of the allostery in this monomeric enzyme is the same as defined by classical theories for multimeric enzymes: making the enzyme response more efficient if appropriate ligands bind.
Primary production dynamics of dominant hydrophytes in Lake Provala (Serbia)
Authors: Nikolić Ljiljana , Pajević Slobodanka , Ljevnaić Branka 
Published: May 2009

Abstract
The objective of this investigation was to analyze the primary production of the dominant hydrophytes by monitoring levels of organic matter and organic carbon and estimating photosynthetic potential via the total chlorophyll content. The survey was conducted in Lake Provala (Serbia) throughout the peak vegetation period of the year 2000. The contents of organic matter and organic carbon for Myriophyllum spicatum L. were 105.11 g m−2 and 73.66 g m−2, Nymphoides peltata (Gmel.) Kunt. were 95.51 g m−2 and 45.26 g m−2 and Ceratophyllum demersum L. were 52.17 g m−2 and 29.75 g m−2. Chlorophyll A (Chl a) and chlorophyll A+B (Chl a+b) pigments ranged from 1.54 mg g−1(Chl a) and 2.1 mg g−1(Chl a+b) in M. spicatum to 5.27 mg g−1(Chl a) and 7.53 mg g−1(Chl a+b) in C. demersum. At full leaf out, the latter aquatic plants exceeded 50% cover of the open water surface. All species achieved maximum growth in June, but significant differences in growth dynamics were observed. At the end of the vegetation period, these plants sink to the bottom and decompose
The expression of inducible nitric oxide synthase (iNOS) in the testis and epididymis of rats with a dihydrotestosterone (DHT) deficiency
Authors: Kolasa Agnieszka , Marchlewicz Mariola , Kurzawa Rafał , Głąbowski Wojciech , Trybek Grzegorz , Wenda-Różewicka Lidia , Wiszniewska Barbara 
Published: May 2009

AbstractIn our previous studies, we showed that a finasteride-induced DHT deficiency may cause changes in the morphology of the seminiferous epithelium without any morphological alteration of the epididymis. In this study, we demonstrated the constitutive immunoexpression of inducible nitric oxide synthase (iNOS) in the testis and epididymis of Wistar rats treated with finasteride for 28 days (the duration of two cycles of the seminiferous epithelium) and 56 days (the duration of one spermatogenesis). We noted that a 56-day finasteride treatment mainly caused a decrease in the level of circulating DHT, as well as a statistically insignificant decrease in the level of T. The hormone deficiency also led to a change in the iNOS immnoexpression in the testis and epididymis of the finasteride-treated rats. In vitro, DHT did not modify NO production by the epithelial cells of the caput epididymis even when stimulated with LPS and IFNγ, but it did give rise to an increase in NO production by the epithelial cells of the cauda epididymis without the stimulation. DHT did not have a statistically significant influence on estradiol production by cultured, LPS- and IFNγ-stimulated epithelial cells from the caput and cauda epididymis. In conclusion, our data clearly indicates that a finasterideinduced DHT deficiency intensifies the constitutive expression of iNOS in most rat testicular and epididymal cells, so it can be expected that the expression of inducible nitric oxide synthase (iNOS) could be regulated by DHT. On the other hand, the profile of the circulating DHT and T levels strongly suggests that the regulation of constitutive iNOS expression is complex and needs more detailed study.
Comparison of isothermal and non-isothermal chemiluminescence and differential scanning calorimetry experiments with benzoyl peroxide
Authors: Rychlý Jozef , Kocer Aysegul , Tanis Fathy , Matisová-Rychlá Lyda , Janigová Ivica , Csomorová Katarína 
Published: May 2009

AbstractDifference in the kinetics of chemiluminescence (CL) and differential scanning calorimetry records for decomposition of originally solid benzoyl peroxide continuing as a melt reaction was outlined. While the main portion of heat measured by DSC is released in the spontaneous decomposition of benzoyl peroxide starting as a homolytic scission of peroxidic bonds, the CL light emission in oxygen comes presumably from the subsequent disproportionation reaction of polyphenyl peroxyl radicals and monitors the induced decomposition of peroxide. Thermogravimetry revealed that oxygen remains partially bound to the products of benzoyl peroxide decomposition.
Estimation of composition, coordination model, and stability constant of some metal/phosphate complexes using spectral and potentiometric measurements
Authors: Abu-Shandi Khalid , Al-Wedian Fadel 
Published: May 2009

AbstractComplexation reactions in a binary metal/phosphate system were studied. Protolytic equilibria of phosphate in the presence of cobalt, nickel, iron, copper, chromium and silver metal ions were investigated by potentiometric titrations in the pH range of 2–11. Stability constants of the metal/phosphate complexes were determined by computer analysis of the potentiometric titration. Potentiometric titrations suggest that the presence of metal phosphate and metal hydrogen phosphate provides the solutions with stability constants logK c 2.21, 2.11, 2.23, 2.34, 1.96, and 2.14 of Co, Ni, Fe, Ag, Cr, and Cu/phosphate, respectively. The results of infrared spectroscopy, X-ray powder diffraction and equilibrium studies were used to reveal the mode of interaction between the metal ions and phosphate. Metal phosphates with a hydrogen phosphate anion and fully nonprotonated phosphate could be isolated under the reaction conditions.