bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Freshwater and Marine Growth Rates on Early Maturity in Male Coho and Chinook Salmon
Authors: Vøllestad Leif Asbjørn , Peterson Jeramie , Quinn Thomas P. 
Published: June 2004

AbstractIn many populations of salmonid fishes, a fraction of the males mature at a younger age than the females; these males are termed jacks if they have migrated to sea and precocious parr if they matured in freshwater. We examined detailed data on the University of Washington hatchery populations of coho salmon Oncorhynchus kisutch and Chinook salmon O. tshawytscha for more than 30 years to test whether rapid growth in freshwater or at sea increases the probability of early maturity in males. The average size of Chinook salmon smolts (2.6–20.9 g) increased over the years in question. The proportion of males maturing as jacks increased with smolt size but not with the potential for growth at sea. The size of the smolts (but not growth potential at sea) was positively correlated with the proportion of the jacks maturing after only one summer at sea (so‐called minijacks) rather than two summers. In coho salmon, average smolt size (6.1–22.4 g) did not vary consistently with time. There was a slight tendency for cohorts with larger smolts to produce more jacks, but marine growth potential was negatively related to the proportion of jacks. For neither species did marine environmental variables influence the proportion of jacks. Taken together, these results support the hypothesis that size prior to seawater entry has the predominate effect on the probability of early maturation and that the growth potential at sea has a neutral or even inhibitory effect on early maturity.
Marine Subsidies in Freshwater: Effects of Salmon Carcasses on Lipid Class and Fatty Acid Composition of Juvenile Coho Salmon
Authors: Heintz Ron A. , Nelson Bonita D. , Hudson John , Larsen Marie , Holland Larry , Wipfli Mark 
Published: June 2004

AbstractReturning adult salmon represent an important source of energy, nutrients, and biochemicals to their natal streams and may therefore have a quantitative effect on the energy levels of stream‐resident salmonids. We tested this hypothesis by constructing simulated streams for coho salmon Oncorhynchus kisutch to which we added 0, 1, and 4 carcasses/m2 (0, 0.71, and 2.85 kg wet mass/m2) of pink salmon O. gorbuscha. After 60 d we evaluated the lipid class and fatty acid composition of rearing coho salmon from the simulated streams; the lipid content and triacylglycerols of the coho salmon increased with increasing carcass density whereas phospholipids decreased. Increased amounts of triacylglycerols accounted for most of the lipid increase. In addition to increasing in concentration, the fatty acid composition of the triacylglycerols also changed with carcass density. Triacylglycerols of juvenile coho salmon from the control streams had significantly higher omega‐3 : omega‐6 ratios as a result of fivefold and sixfold increases in the concentrations of eicosapentanoic and docosahexanoic fatty acids, respectively. These data demonstrate an immediate nutritional benefit resulting from the introduction of salmon carcasses in juvenile coho salmon rearing habitat and indicate the utility of fatty acid and lipid class analysis for examining the effects of marine‐derived nutrients on juvenile salmonids.
Comparison of Alewife Young‐of‐the‐Year and Adult Respiration and Swimming Speed Bioenergetics Model Parameters: Implications of Extrapolation
Authors: Klumb Robert A. , Rudstam Lars G. , Mills Edward L. 
Published: June 2004

AbstractParameters derived from laboratory experiments that separately measured the routine metabolic rates (respiration) and swimming speeds of young‐of‐the‐year (age‐0) alewives Alosa pseudoharengus were compared with values published for a bioenergetics model for adults. Respiration rates of age‐0 alewives were significantly influenced by water temperature and scaled isometrically with weight (range, 0.0001–1 g). Swimming speed was strongly related to fish weight and, unlike for adult alewives, water temperature significantly influenced the swimming speeds of age‐0 fish. Temperature coefficients, along with the slopes for the weight dependence of age‐0 alewife respiration rates and swimming speeds, significantly differed by 51–709% from published parameters for adults. Using adult parameters, the standard respiration rates at 15–25°C of age‐0 alewives weighing less than 0.02 g were overestimated by 7–88% and the swimming speeds for fish weighing less than 1.0 g were overestimated by 130–4,270%. Application of our age‐0 alewife swimming speed parameters in the exponential activity function used in the adult bioenergetics model resulted in no activity costs for age‐0 fish smaller than 0.2 g, which is clearly unrealistic. Because no data relating respiration to activity level (i.e., concurrent measurements of respiration and swimming speed) currently exist for age‐0 alewives, we recommend using routine respiration rates without an activity multiplier to represent the costs of normal activity in the field. All parameters derived in this study for age‐0 alewives differed from those of adults by more than 10%, a deviation commonly used in sensitivity analyses of bioenergetics models, which indicated that application of adult parameters to early life stages was not warranted. Use of metabolism–weight relations from the literature derived for multiple species also are not recommended because the estimated routine metabolic rates of age‐0 alewives differed by 2–311% from rates measured in this study.
Fish Size and Prey Availability Affect Growth, Survival, Prey Selection, and Foraging Behavior of Larval Yellow Perch
Authors: Graeb Brian D. S. , Dettmers John M. , Wahl David H. , Cáceres Carla E. 
Published: June 2004

AbstractZooplankton availability is strongly linked with the growth, survival, and ultimately recruitment of fish during their early life history. We examined how different types of zooplankton affected the growth, survival, and prey selection of larval yellow perch Perca flavescens in a series of laboratory experiments. The growth and survival of newly hatched (5–7‐mm) to 12‐mm yellow perch larvae was greatest when feeding on adult copepods and copepod nauplii. The growth and survival of yellow perch larvae longer than 12 mm was greatest when feeding on adult copepods and small cladocerans. Prey selection patterns closely followed trends in growth and survival; smaller larvae positively selected adult and naupliar copepods, whereas larger larvae selected adult copepods and small cladocerans. Foraging behavior experiments conducted with larvae longer than 12 mm revealed that these fish derived similar energetic gains when feeding solely on adult copepods and small cladocerans. The pathway to this energetic benefit differed substantially between prey types. Adult copepods yielded substantial energy to larval yellow perch because of the minimal handling time involved, despite the lower capture efficiency than with cladocerans. Conversely, yellow perch larvae realized high energetic gain from small cladocerans because of high capture efficiency, despite the higher handling times than with adult copepods. These results illustrate the importance of experimentally quantifying the feeding behavior of fish larvae to gain insight into how larval fish behavior and food type interact to shape larval fish growth patterns.
Distribution, Growth, and Feeding of Sockeye Salmon in the Western Bering Sea
Authors: Radchenko Vladimir I. , Mathisen Ole A. 
Published: June 2004

AbstractThe Pacific Research Institute of Fisheries and Oceanography (TINRO) in Vladivostok, Russia, conducted 12 major biological surveys in the western Bering Sea in 1986–1995. During these surveys, sockeye salmon Oncorhynchus nerka were sampled with a new pelagic trawl. We used salmon catch, age and growth, and diet data from the TINRO surveys to evaluate the role of sockeye salmon in the structure and function of pelagic communities in the western Bering Sea. Estimates of abundance (numbers and biomass) showed large annual and seasonal fluctuations in the western Bering Sea. Immature and maturing sockeye salmon migrated to the western Bering Sea in late spring from their winter (December–May) feeding grounds in the North Pacific Ocean. Maturing sockeye salmon were distributed in the western Bering Sea from June to early August before returning to their natal spawning rivers. In late August, smolts (age n.0, where the n indicates an ocean‐age cohort and zero indicates the number of ocean annuli) began to move from coastal to offshore waters, where the largest numbers occurred in September–November. We inferred from catch data that most of the other age‐groups of sockeye salmon left the western Bering Sea by the end of November and moved southward to the North Pacific Ocean. The analyses indicated that sockeye salmon fed in the seasonal thermocline layers, where they were important consumers of interzonal zooplankton and micronektonic organisms. The dietary ration of sockeye salmon was high. The high growth rates of sockeye salmon in the western Bering Sea were comparable to those in the North Pacific Ocean. The wide distribution, numerous trophic linkages, high rations, and high growth rate of sockeye salmon establish their important role in pelagic communities of the western Bering Sea.
A Model‐Based Assessment of the Potential Response of Snake River Spring–Summer Chinook Salmon to Habitat Improvements
Authors: McHugh Peter , Budy Phaedra , Schaller Howard 
Published: June 2004

AbstractThe current recovery strategy for threatened Snake River Chinook salmon Oncorhynchus tshawytscha relies heavily on improvements to the quality of freshwater spawning and rearing habitat; however, the potential survival benefit from these actions is unknown. To address this issue, we created a model for predicting the early freshwater survival rates (egg to smolt) of this species as a function of five easily measured physical habitat variables and used this model to evaluate survival rates under five alternative future habitat states. Model validation showed that the predictions were reasonably accurate for individual stocks as well as for the trend in predictions across stocks. The results for the future habitat scenarios suggest that the potential for improving survival rates through habitat restoration is high for a few populations and low to nonexistent for most others while the potential for reduction in survival rates due to reduced habitat quality is great for all populations. The effects of modeled egg‐to‐smolt survival rate changes should be evaluated across the entire Chinook salmon life cycle to assess recovery potential.
Effect of Temperature on the Identification of Larval Black Crappies, White Crappies, and F1 Hybrid Crappies
Authors: Spier Timothy W. , Ackerson Jonathan R. 
Published: June 2004

AbstractMyomere counts have been used to differentiate larval black crappies Pomoxis nigromaculatus and white crappies P. annularis; however, both hybridization and water temperatures during egg development can influence myomere numbers and thereby interfere with identification of larval crappies. We artificially produced pure black crappies, white crappies, and their F1 hybrids and allowed them to develop at different temperatures. We then compared counts of preanal, postanal, and total myomeres among taxa and water temperatures. Although white crappies had significantly more preanal myomeres and significantly fewer postanal myomeres than the black crappies or the F1 hybrids, counts of these myomeres overlapped too much to be useful for identification purposes. Some of the overlap of myomere numbers was caused by variation due to natal water temperature differences. Higher temperatures caused the anus to develop more posteriorly in larval crappie, influencing the number of preanal and postanal myomeres. Because myomere counts overlap so much and because hybridization and natal water temperature can induce variation in myomere numbers, myomere counts are not useful for discriminating between the two species of Pomoxis.
Consequences of Vegetation Density and Prey Species on Spotted Gar Foraging
Authors: Ostrand Kenneth G. , Braeutigam Ben J. , Wahl David H. 
Published: June 2004

AbstractAdult spotted gar Lepisosteus oculatus are potentially important components of food webs given their predatory habits and high relative abundance. However, few studies have examined their foraging behavior. Therefore, we examined the effects of vegetation density on the foraging success of adult spotted gars preying on bluegill Lepomis macrochirus and fathead minnow Pimephales promelas. Spotted gars use ambush foraging and were more successful capturing fathead minnow than bluegills at all stem densities. Predation success was negatively correlated with stem density for bluegill prey but not for fathead minnow. Although fathead minnow and bluegills shoaled less as stem density increased, bluegills modified their behavior in the presence of a predator by moving lower in the water column at high stem densities, whereas fathead minnow did not. Predatory behaviors were directed at prey within a short distance and near the surface of the water. Foraging of spotted gar, a lie‐in‐wait predator, was primarily influenced by prey behavior, with the amount of vegetative cover playing a secondary role that also varies with prey species.
Factors Associated with the Risk of Liver Enzyme Elevation in Patients with Type 2 Diabetes Treated with a Thiazolidinedione
Authors: St. Peter John V. , Neafus Kristin L. , Khan Mehmood A. , Vessey John T. , Lockheart Michael S. K. 
Published: June 2004

Study Objective. To characterize frequency of liver enzyme elevation in patients with type 2 diabetes mellitus receiving troglitazone.Design. Retrospective study.Setting. Hospital‐affiliated medical center.Patients. Two hundred ninety‐one patients with type 2 diabetes mellitus.Intervention. Data from patients with an average troglitazone exposure of 412.7 ± 255.6 days were studied.Measurements and Main Results. Enzyme elevations more than 1.5 times the upper limit of normal (ULN) occurred in 17 patients (5.8%) and more than 3‐fold elevations in 6 (2.1%). The relationship among enzyme elevation events, demographic factors, duration of troglitazone exposure, frequency of monitoring, and concurrent drugs (limited to glucose and lipid‐lowering agents) was assessed by multiple logistic regression. Age was an independent predictor of risk (p=0.009), and concurrent insulin therapy approached statistical significance (p=0.051) for 1.5‐fold ULN elevation in liver enzymes. Age and concurrent therapy with 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors were the only significant predictors of 3‐fold ULN elevations (p=0.03 and p=0.04, respectively).Conclusion. Several factors appear to increase the risk of enzyme elevation events in patients treated with troglitazone.
Phenylacetate Pharmacokinetics Based on Iterative Two‐Stage Population Analysis
Authors: Burstein Aaron H. , Reed Eddie , Tompkins Anne C. , Venzon David , Figg William D. 
Published: June 2004

Study Objective. To determine the population pharmacokinetics of phenylacetate using iterative two‐stage analysis implemented with ADAPT II software.Setting. United States government research hospital.Design. Retrospective pharmacokinetic analysis.Subjects. Sixty‐seven patients with refractory solid tumors.Intervention. Subjects received from 1–10 courses/individual (total 141 courses) of therapy with either twice‐daily administration or continuous infusions of phenylacetate.Measurements and Main Results. Extensive plasma concentration measurements were performed after the initial dose or start of infusion, with sparse sampling during subsequent courses of therapy. Phenylacetate plasma concentration‐time profiles were described by a one‐compartment, capacity‐limited clearance model with incorporation of parameters to describe extent of induction of clearance and the rate of induction. Median estimates for volume of distribution, maximum rate of drug elimination, Michaelis‐Menten constant, and induction factor, and rate of onset of induction of drug clearance were 0.33 (0.26, 0.48) L/kg, 21.8 (16.3, 28.0) mg/kg/hour, 94.6 (48.8, 153.0) mg/L, 1.28 (1.06, 1.66), and 0.0038 (0.0019, 0.0058) hour−1, respectively.Conclusion. The results of this study are similar to previous pharmacokinetic evaluations using the Abbottbase PKS system but suggest that earlier analyses were suboptimal.
Evaluation of Very Low‐Dose Subcutaneous Vitamin K During Postoperative Warfarin Therapy
Authors: Possidente Carl J. , Howe James G. , Cushman Mary 
Published: June 2004

Study Objective. To determine the effect of very low‐dose subcutaneous vitamin K (SCVK) compared with withholding warfarin for above‐target international normalized ratio (INR) values after joint surgery.Design. Historical controlled study.Setting. University hospital.Subjects. One hundred thirty‐nine patients beginning warfarin after total joint surgery.Intervention. For a high INR, warfarin was either withheld or SCVK 100, 300, or 400 μg was administered, depending on INR value.Measurements and Main Results. The primary outcome was change in INR from the day of intervention (day 1) to the next day (day 2). Adjusting for day 1 INR, the mean day 2 INR was 2.10 (95% confidence interval [CI] 1.86–2.33) after SCVK, compared with 2.73 (95% CI 2.50–2.96) in controls. This corresponded to declines of −0.72 and −0.08, respectively (p=0.001).Conclusion. In orthopedic patients starting warfarin therapy, very low‐dose SCVK was more effective than withholding warfarin in reducing high INRs. Investigations in other populations and assessment of the effect of low‐dose SCVK on postoperative bleeding are indicated.
Evaluation of the Ability of Seven Herbal Resources to Answer Questions About Herbal Products Asked in Drug Information Centers
Authors: Walker J. Bryan 
Published: June 2004

Study Objective.To evaluate the ability of seven widely known herbal references and electronic databases to answer questions about herbal products asked at drug information centers.Design.Cross‐sectional study.Setting.Five academic and institutional drug information centers.Methods.Fifty‐seven herbal‐related questions were obtained from academic and institutional drug information centers. Seven herbal references and electronic databases were evaluated for their ability to answer these 57 questions:The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines, 1st edition; Physicians' Desk Reference (PDR) for Herbal Medicines, 2001 edition; Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 4th edition; The Lawrence Review of Natural Products, 2001; Natural Medicines Comprehensive Database (electronically updated, 2001); The Natural Pharmacist (electronically updated, 2001); and AltMedDex (electronically updated, 2001).Results.Natural Medicines Comprehensive Database outperformed all other products evaluated, providing direct answers to 61% of questions. AltMedDex and The Natural Pharmacist performed similarly to one another, answering 49% and 44% of questions, respectively.The Lawrence Review of Natural Products, PDR for Herbal Medicines, The Complete German Commission E Monographs, andTyler's Honest Herbal were the least helpful in providing direct answers to the questions (24%, 21%, 11%, and 9%, respectively).Conclusion.Natural Medicines Comprehensive Database, AltMedDex, and The Natural Pharmacist outperformed all other evaluated herbal references and electronic databases in their ability to answer questions about herbal products posed in clinical practice.
Population Pharmacokinetic Modeling of Pyrazinamide in Children and Adults with Tuberculosis
Authors: Zhu Min , Starke Jeffrey R. , Burman William J. , Steiner Phillip , Stambaugh Jerry Jean , Ashkin David , Bulpitt Amy E. , Berning Shaun E. , Peloquin Charles A. 
Published: June 2004

Study Objective. To determine population pharmacokinetic parameters of pyrazinamide after multiple oral doses given to children and adults with tuberculosis.Design. Prospective, multiple‐dose population pharmacokinetic study.Setting. Five hospitals in the United States.Patients. Sixty‐seven adults and 23 children with active tuberculosis.Intervention. The 90 patients received multiple oral doses of pyrazinamide as part of their treatment, based on the best clinical judgment of the attending physicians and in keeping with standard clinical practices at each institution. The patients also received other antituberculosis drugs empirically or based on in vitro susceptibility data.Measurements and Main Results. Serum samples were collected over 12 hours after dosing and were assayed with a validated gas chromatography assay with mass selective detection. Concentration‐time data were analyzed by using population methods. Pyrazinamide concentrations increased linearly with increasing oral doses (185–3550 mg). Median maximum serum concentration values were 41.0 μg/ml with daily dosing and 66.1 μg/ml with larger, twice‐weekly dosing. Incomplete (18%) or delayed (30%) absorption was more common in children than in adults (1% for each). Pharmacokinetic parameters of pyrazinamide were independent of human immunodeficiency virus status and patient demographics, except for body weight. Population elimination half‐life values in pediatric and adult patients were 3.5 and 6.0 hours, respectively. Median volume of distribution (L/kg) was 32% larger in children, and median clearance (L/hr/kg) was 106% larger in children, with a resultant median half‐life 43% shorter in children.Conclusion. Pyrazinamide concentrations and most pharmacokinetic parameters were comparable to those previously published. Apparent half‐life was somewhat shorter than that in previous reports. Compared with adults, absorption of pyrazinamide in children appeared more likely to be incomplete or delayed.
Limited Tolerability of Levofloxacin and Pyrazinamide for Multidrug‐Resistant Tuberculosis Prophylaxis in a Solid Organ Transplant Population
Authors: Lou Huei‐Xin , Shullo Michael A. , McKaveney Teresa P. 
Published: June 2004

Study Objective. To determine the long‐term tolerability of prophylactic administration of pyrazinamide and levofloxacin in patients possibly exposed to multidrug‐resistant tuberculosis (MDRTB) after undergoing solid organ transplantation.Design. Retrospective analysis.Setting. Community outpatient clinic.Patients. Forty‐eight recipients of solid organ transplants beginning prophylaxis for MDRTB during August 1999 after possible exposure to a single index case of multidrug‐resistant Mycobacterium tuberculosis within our community.Intervention. Prophylaxis consisted of pyrazinamide 30 mg/kg/day plus levofloxacin 500 mg/day, administered for 1 year.Measurements and Main Results. Thirteen (27.1%) of the 48 patients completed therapy; 27 (56.3%) discontinued therapy within 4 months due to adverse drug events. Gastrointestinal intolerance was the major adverse event resulting in early discontinuation.Conclusion. Prophylaxis of MDRTB with levofloxacin and pyrazinamide was associated with limited tolerability due to the high frequency of adverse events. While we search for a better tolerated prophylactic regimen, close monitoring for adverse reactions is recommended.