The influence of voice pitch on perceptions of trustworthiness across social contexts

Perceptions of trustworthiness are an important predictor of social outcomes, such as monetary exchanges, criminal sentencing, and the attainment of leadership roles. Higher testosterone levels predict both lower voice pitch and untrustworthy behavior, across economic and mating contexts. Here, we tested the influence of voice pitch on perceptions of trustworthiness across general, economic, and mating-related (mate poaching, infidelity) contexts. We found that the context of trust and the sex of the speaker both changed how voice pitch affected perceived trustworthiness. Listeners were more trusting of higher-pitched female voices in economic and mate poaching contexts, but trusted lower-pitched female voices more in general. Listeners were more trusting of higher-pitched male voices in economic and mating-related contexts, and also tended to perceive higher-pitched male voices as more trustworthy in general. Listeners' attributions of trustworthiness were generally unrelated to perceptions of attractiveness from similarly-pitched voices, indicating that trust-related attributions were independent of preferences for higher- or lower-pitched voices. Furthermore, perceptions of general trustworthiness were associated with perceptions of economic trust, but were not consistently associated with perceptions of mating-related trust. These findings provide evidence that voice pitch alone is sufficient to influence trust-related perceptions, and demonstrates that listeners use voice pitch as a cue to trustworthy behavior.     

Repeatability and precision of a weighted centroid method for estimating dynamic in vivo tibiofemoral surface interactions in sheep

Persistent changes in joint biomechanics resulting from knee injury are thought to contribute to progressive cartilage damage and post-traumatic osteoarthritis (PTOA). The identification and quantification of in vivo tibiofemoral surface interactions are critical to understanding them, particularly abnormal interactions that are damaging to articular cartilage and other structures of the knee. In this study, we describe an approach for understanding such potential interactions by using a weighted centroid derived from in vivo stifle kinematics in sheep. Collectively, repeatability and sensitivity analyses indicate that the magnitude of the changes in tibiofemoral centroid location resulting from combined ligament transection is greater than the repeatability and precision of the current weighted centroid approach, making this method useful for describing the changes in dynamic surface interactions that may be relevant in the pathogenesis of PTOA in this stifle injury model.     

The metabolic integrity of Fasciola hepatica during in vitro maintenance

Levels of metabolic intermediates and end products in F. hepatica after 24 and 48 h in Hédon-Fleig salt solution with added glucose were compared with levels obtained immediately on removal from the host. Glycogen levels dropped initially, probably due to the expulsion of eggs; thereafter they remained constant. Internal glucose concentrations increased as the parasites equilibrated with the medium. Other changes in internal pool sizes were consistent with regulation to the in vitro conditions. ATP levels increased; ATP/ADP ratios were maintained. Comparisons of mass action ratios and equilibrium constants suggest that hexokinase, pyruvate kinase and phosphofructokinase are regulatory. Output of excretory products approached linearity; from the calculated regressions the proportions of lactate, acetate and propionate were 1: 2: 4. The implications for metabolic regulation in F. hepatica are briefly discussed, and it is concluded that, for at least 48 h in vitro, energy metabolism is not adversely affected.     

The identification of disease-induced biomarkers in the urine of BSE infected cattle

Background  

The bovine spongiform encephalopathy (BSE) epidemic and the emergence of a new human variant of Creutzfeldt-Jakob Disease (vCJD) have led to profound changes in the production and trade of agricultural goods. The rapid tests currently approved for BSE monitoring in slaughtered cattle are all based on the detection of the disease related isoform of the prion protein, PrP^d, in brain tissue and consequently are only suitable for post-mortem diagnosis. Objectives: In instances such as assessing the health of breeding stock for export purposes where post-mortem testing is not an option, there is a demand for an ante-mortem test based on a matrix or body fluid that would permit easy access and repeated sampling. Urine and urine based analyses would meet these requirements.