A Low-Cost GPS GSM/GPRS Telemetry System: Performance in Stationary Field Tests and Preliminary Data on Wild Otters (Lutra lutra)

Background: Despite the increasing worldwide use of global positioning system (GPS) telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects. Methodology/Principal Findings: We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra). The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD = 8.55). GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%). Conclusions/Significance: Our results suggest that GPS telemetry is reliably applicable to riparian and even divin

A Survey of Experimental Research on Contests, All-Pay Auctions and Tournaments

Many economic, political and social environments can be described as contests in which agents exert costly efforts while competing over the distribution of a scarce resource. These environments have been studied using Tullock contests, all-pay auctions and rankorder tournaments. This survey provides a review of experimental research on these three canonical contests. First, we review studies investigating the basic structure of contests, including the contest success function, number of players and prizes, spillovers and externalities, heterogeneity, and incomplete information. Second, we discuss dynamic contests and multi-battle contests. Then we review research on sabotage, feedback, bias, collusion, alliances, and contests between groups, as well as real-effort and field experiments. Finally, we discuss applications of contests to the study of legal systems, political competition, war, conflict avoidance, sales, and charities, and suggest directions for future research. (author's abstract

Ascorbic acid in the gonads of North Sea dab (Limanda limanda) during the reproductive cycle.

Total ascorbic acid was measured in the gonads of North Sea dab (Limanda limanda) throughout one reproductive cycle. In the ovaries, the concentration of ascorbate began to increase during the resting period in summer and reached maximum values of 400 μg .g fresh weight (fw)-1 at the onset of ovary maturation in fall. Concentrations declined rapidly towards the spawning period in spring and reached the lowest values of 80-100 μg .g fw-1. The maximum deposition of ascorbate in the ovaries amounted to 2.5 mg .organ-1 and occurred in late winter, corresponding to the beginning of the spawning period. In the testes, ascorbate concentrations were lower than in the ovaries, reaching a maximum of 170 μg .g fw-1 in early fall. The lowest values of 20-60 μg .g fw-1 appeared in winter and spring. In the testes the highest deposition of ascorbate amounted to 110 μg .organ-1 and appeared at the beginning of maturation. The sexual differences and seasonal variations are discussed in relation to the reproductive biology of dab. </jats:p

measurement of swimming performance of wild Atlantic salmon (

Swimming capabilities and in situ measurement of muscle activity from adult Atlantic salmon (Salmo salar) at two seasonal temperatures were measured using radio transmitted electromyogram (EMG) signals. Forced sustained levels of activity and critical swimming speeds were determined and correlated to radio transmitted EMG signals using a modified Blazka swim speed chamber. There were no differences in swimming performance levels between tagged and untagged individuals. At 18 °C, sustained activity and critical swimming speeds were approximately 70% and 20% higher than at 12 °C, respectively. No differences in burst activity were observed at these temperatures. EMGs recorded from salmon during ascent of an artificial flume at cold temperatures revealed that overall muscle activity is greater than that observed for critical swimming speeds. This implies that white muscle may be recruited at this temperature. However, in contrast, most activity at 18 °C is below that observed during critical swimming speed. Moreover, salmon required almost twice as long to traverse the flume at 18 °C than at 12 °C. Together, our data demonstrates that salmon may recruit white muscle fibres and incur an oxygen debt at colder temperature as a strategy for ascending velocity obstructions at a quicker rate

Tissue oxygen saturation changes during intramedullary nailing of lower-limb fractures

BACKGROUND: The systemic complications of acute intramedullary nailing (IMN) in trauma patients are well known. There are no reliable methods available to predict these adverse outcomes. Noninvasive near-infrared spectroscopy (NIRS) allows measurement of oxygen saturation within muscle tissue (StO2) and quantification of the potential metabolic and microcirculatory effects of IMN in real time. The aim of this study was to characterize tissue oxygenation changes occurring during reamed IMN. METHODS: Patients undergoing reamed IMN for fixation of a tibia or femur fracture and patients having an open reduction and internal fixation of the ankle (to control for potential effects of anesthesia) had a noninvasive NIRS probe attached to the thenar eminence of the hand. Tissue oxygenation was monitored continuously throughout the operation and digitally recorded for later analysis. Vascular occlusion tests, an established technique with the NIRS device, were performed before canal opening and after nail insertion (at equivalent times in the control group), to establish the presence and nature of changes in systemic microcirculation occurring during the duration of the operation. RESULTS: Tissue oxygenation data were collected on 23 patients undergoing 26 IMN. (mean [SD] age, 36 [19] years; median Injury Severity Score [ISS], 9; interquartile range, 9–12). The control group consisted of 19 patients (mean [SD] age, 41 [18] years; ISS, 4). Remote muscle tissue desaturated significantly faster after IMN compared with the control operation (mean [SD] difference in IMN desaturation rate, 1.8% per minute [2.6% per minute]; mean [SD] difference in control group desaturation rate, -0.6% per minute [1.5% per minute]; p = 0.014). Near infrared-derived muscle oxygen consumption (NIR VO₂) was significantly increased during the course of IMN compared with the control (mean [SD] difference in IMN NIR VO₂, 19.9 [32.1]; mean [SD] difference in control NIR VO₂, -4.2 [17.9]; p = 0.041). CONCLUSION: IMN causes significant remote microcirculatory changes. The responsiveness of the microcirculation could be a predictor of secondary organ dysfunction. LEVEL OF EVIDENCE: Epidemiologic study, level III