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Piscivorous birds in aquatic ecosystems exert predation pressure on fish populations. But the site-specific impact on fish populations, including stocked and commercially used fish species, remains disputed. One of the key questions for the management of piscivorous birds and fish is determining the origin of prey and thus which fish populations are targeted by the birds. We addressed this question by provenancing otoliths (earstones) of fish obtained from regurgitated pellets of piscivorous birds by otolith microchemistry analysis. We retrieved otoliths from regurgitated pellets of great cormorants (

OBJECTIVES The objectives were to determine if nebulized albuterol causes an increase in the serum lactate level compared to placebo and, secondarily, to confirm that albuterol decreases serum potassium levels compared to placebo in patients with normokalemia. METHODS This was a randomized, double-blind, placebo-controlled trial. Twenty-eight healthy adult volunteers were assigned to receive either 10 mg of nebulized albuterol or placebo (nebulized saline) over 1 hour. Serum lactate was measured prior to treatment and at 30 and 70 minutes after the start of treatment. Serum potassium level was measured prior to treatment and at 70 minutes. The primary outcome was the degree of change in lactate level. The secondary outcome was the degree of change in potassium level. RESULTS In the 14 subjects who received albuterol, the mean increase in lactate was 0.77 mmol/L (95% confidence interval [CI] = 0.52 to 1.02 mmol/L), and the mean decrease in potassium level was 0.5 mEq/L (95% CI = -0.72 to -0.28 mEq/L). Among the subjects who received placebo, the lactate level decreased by 0.15 mmol/L (95% CI = -0.39 to 0.09 mmol/L) and there was no change in potassium level at (0.0 mEq/L [95% CI = -0.21 to 0.21 mEq/L]). These differences are statistically significant (p < 0.0001 and p = 0.003, respectively). CONCLUSION Nebulized albuterol increases lactate levels and decreases potassium levels in healthy adults.

The maternal transmission of a naturally occurring and non-toxic minor isotope of strontium (84Sr) to the central otolith region of the progeny of a typical European freshwater fish species, brown trout, Salmo trutta f.f. L. was accomplished. The focus was to apply minimum doses of a non-toxic solution at physiological salt concentration to minimise potential adverse effects on the fish. Female spawners were intraperitoneally injected with doses of 12.5 and 30.2 μg 84Sr kg−1 fish. Eggs were stripped and the resulting progeny were reared in a hatchery for about 1 year before sampling the otoliths. Strontium isotope ratios in the otoliths of the offspring were measured by cross-sectional line scans using laser ablation-multiple collector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS). Otolith cores of marked juveniles showed a significantly elevated 84Sr/86Sr ratio compared with control fish and to otolith regions created after hatching. Mass marking of cohorts of progeny from individually spiked brown trout with Sr isotopes is therefore possible for dispersal and migration studies without the necessity of handling eggs and applying other larval marking methods like immersion.

This paper explores the interactive effect of competitiveness and choice structure on symbolic (noninstrumental) choices in competitive situations. When individuals in competitive situations learn the stated preference of their opponent, their own choice depends on their competitiveness and on whether they are in an inclusive-choice situation (in which both competitors can end up with the same option) or an exclusive-choice situation (in which they cannot). We obtained this predicted interaction in an imagined video game challenge (Studies 1 and 3), cooking contest (Study 2), and March Madness bracket competition (Study 4). Highly competitive people copied their opponent's choices in exclusive-choice situations, and seemed to do this because they wanted to frustrate their opponent (Studies 3 and 4).

The potential to discriminate between wild and hatchery trout [Salmo trutta f. fario L. and Oncorhynchus mykiss (Walbaum)] by chronological microchemical patterns of different otolith regions was tested. Central and rim regions of otoliths were analysed for life stage specific elemental patterns of strontium (Sr), sodium (Na) and calcium (Ca) as well as of 87Sr/86Sr ratios using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Classification to life stage specific habitats was achieved with 100% accuracy by 88Sr/43Ca, 23Na/43Ca and 87Sr/86Sr ratios resulting in a discrimination of hatchery fish from wild fish. 87Sr/86Sr ratios and Sr concentration in otoliths were positively correlated with the ratio and amount in the water. Na content in otoliths did not directly reflect the concentration in the water, although the 23Na/43Ca ratio in otoliths contributed to the discrimination. Clear differences in otolith chemistry were found for fish experiencing different geological units or a groundwater-fed environment in a hatchery. Natural chronological microchemical patterns in otoliths proved to be a valuable tool for discriminating wild and hatchery fish without the necessity to use marking methods. LA-ICP-MS is well suited for this application because of its limited need for sample preparation, its potentially high sample throughput and the possibility of simultaneous measurement of multiple elemental and isotopic fingerprints.

A total of 10 649 larval and juvenile fishes of 24 species were caught in the drift at Marchfeldkanal, a man-made side branch of the Danube River near Vienna, Austria, with tubenose goby Proterorhinus marmoratus being the dominant species. Distinct differences in inter- and intraspecific drift patterns among different sampling stations along the course of the channel were found. The percentage of the rheophilic and rheoparous ecological guild was highest at the inlet of the channel, where it is directly fed with water from the Danube. For individual species, significant differences in drift densities among sites were found for tubenose goby, barbel Barbus barbus, ide Leuciscus idus, roach Rutilus rutilus and for the two most abundant percids, the pike-perch Sander lucioperca and zingel Zingel zingel combined. The occurrence of larval and juvenile fishes in the drift was related to certain developmental stages and differed between species and sites. Most species (common bream Abramis brama, bleak Alburnus alburnus, gudgeon species Gobio spp., chub Leuciscus cephalus, ide and roach) occurred with highest densities at the earliest developmental larval stage, but some species (e.g. common bream and roach) were also found abundantly in drift at later developmental stages. Application of Ivlev‘s index of electivity as a drift index describing the propensity of the different species to drift, yielded the highest indices for the gudgeon species, common bream and bleak and the lowest for perch Perca fluviatilis, Prussian carp Carassius auratus gibelio and rudd Scardinius erythrophthalmus.

Seasonal and diurnal patterns of larval and juvenile fish drift were investigated in the Marchfeldkanal, a man-made side branch of the Danube River near Vienna, Austria. A clear seasonal pattern with peak densities in mid-June was found. Species composition varied over time, showed a site specific pattern and was dominated by tubenose goby Proterorhinus marmoratus. Water temperature was the main factor responsible for the increase of drift densities until the median drift date and repeated occurrence of early larval stages in drift indicated repeated spawning for many species. Significant differences in drift densities between different time periods of the day (day, dusk, night and dawn) were found for common bream Abramis brama, barbel Barbus barbus, chub Leuciscus cephalus, tubenose goby and roach Rutilus rutilus. The highest drift rates occurred at night (2200–0400 hours), with 86% of all larvae drifting during the hours of darkness. Fish larvae of different lengths drifting at different phases of the day were found for common bream, bleak Alburnus alburnus and chub, with largest larvae drifting during dusk (chub) and day (bleak and common bream). For bleak, all gudgeon species Gobio spp., tubenose goby, roach and for all cyprinid species combined, one 2 h night sample was found to be sufficient to predict the total 24 h drift.

Our contribution deals with a description of yield in glassy polymers, being treated as an activated process. For description the Eyring equation in simplified form has been selected: ((1)) where σy = yield stress, T = absolute temperature, and A, B, C = equation parameters. In the first part the applicability of this equation has been verified by applying data of our own as well as those published elsewhere. For a more comprehensive representation of the results the data were processed in the form of generalized master curves by using the appropriate shift factors derived from eq. (1).