Use of strontium isotope ratios in geolocation of Guatemalan population: Potential role in identification of remains.

Within post-conflict communities, attempts to identify and repatriate unidentified and missing individuals poses a difficult task. As current forensic strategies commonly lack the capacity to provide region of origin assessments, forensic anthropologists/investigators are often unable to identify sources of DNA for kinship analysis. Using Thermal Ionization Mass Spectrometry (TIMS), hair samples from 10 volunteers were used to assess the variation in strontium isotope ratios (87 Sr/86 Sr) between extant people in Guatemala City and Coban; with a leach (external) and digest (dietary) signal analyzed for each sample. A two-way anova demonstrated that the difference between 87 Sr/86 Sr of Guatemala City and Coban was statistically significant (F [1, 16] = 259.839, p < 0.05), with no statistically significant differences observed between leach and digest 87 Sr/86 Sr (F [1,16] = 4.319, p = 0.054). Overall, individuals from Coban demonstrate 87 Sr/86 Sr comparable to previously recorded baseline values, demonstrating a minimal change in diet which is reflected in associated surveys. Volunteers from Guatemala City, however, show a marked shift in 87 Sr/86 Sr away from predicted values highlighting the potential influence of imported goods. The results here highlight the applicability of 87 Sr/86 Sr in hair to serve as a potential tool to support the identification of unknown individuals in Guatemala in a forensic context.

Optimal Emotional Profiles for Peak Performance in Strength and Conditioning.

ABSTRACT: Cooper, JJ, Johnson, M, Radcliffe, J, and Fisher, J. Optimal emotional profiles for peak performance in strength and conditioning. J Strength Cond Res 35(3): 833-840, 2021-This study investigated athletes' performance-related emotions and emotional profiles for optimal performance in strength and conditioning (S&C). It is suggested that the identification and control of emotions associated with successful and unsuccessful performances are essential for achieving peak psychological states and optimal performance in sports-related tasks. The individual zone of optimal functioning (IZOF) model outlines an idiographic and comprehensive conceptual framework of interrelated dimensions that describe the structure and dynamics of subjective emotional experiences and performance-related psychobiological states. With institutional ethics approval, 13 competitive elite athletes (male, n = 7; female, n = 6: mean age = 21.7 ± 4.0 years) completed IZOF-based emotion profiling, in which subjects were asked to recall their perceived best and worst S&C session, outlining emotions and intensity within 4 global emotional categories. A significant difference was evidenced between best ever and worst ever performance within positive functional emotions (p < 0.001, d = 3.63) and negative dysfunctional emotions (p < 0.001, d = 4.92). Initial findings suggest that perceived peak performance states within S&C are associated with a high intensity of positive functional emotions (confident, motivated, and energetic) and a low intensity of negative dysfunctional emotions (worn out, sluggish, annoyed, and discouraged). Although future research is necessary to fully understand this area, the present data suggest that to assist athletes in achieving perceived peak performance states within S&C, psychological skills and strategies should be informed and developed in collaboration with sport psychologists, with the aim of achieving an optimal emotional profile.

Efficacy of Dog Training With and Without Remote Electronic Collars vs. a Focus on Positive Reinforcement.

We assessed the efficacy of dog training with and without remote electronic collars compared to training with positive reinforcement. A total of 63 dogs with known off-lead behavioral problems such as poor recall were allocated to one of three training groups (each n = 21), receiving up to 150 min of training over 5 days to improve recall and general obedience. The 3 groups were: E-collar-manufacturer-nominated trainers who used electronic stimuli as part of their training program; Control 1-the same trainers following practices they would apply when not using electronic stimuli; and Control 2-independent, professional trainers who focused primarily on positive reinforcement for their training. Data collection focused on dogs' response to two commands: "Come" (recall to trainer) and "Sit" (place hindquarters on ground). These were the two most common commands used during training, with improving recall being the target behavior for the subject dogs. Measures of training efficacy included number of commands given to elicit the response and response latency. Control 2 achieved significantly better responses to both "Sit" and "Come" commands after a single instruction in the allocated time. These dogs also had shorter response latencies than the E-collar group. There was no significant difference in the proportion of command disobeyed between the three groups, although significantly fewer commands were given to the dogs in Control 2. There was no difference in the number of verbal cues used in each group, but Control 2 used fewer hand and lead signals, and Control 1 made more use of these signals than E-collar group. These findings refute the suggestion that training with an E-collar is either more efficient or results in less disobedience, even in the hands of experienced trainers. In many ways, training with positive reinforcement was found to be more effective at addressing the target behavior as well as general obedience training. This method of training also poses fewer risks to dog welfare and quality of the human-dog relationship. Given these results we suggest that there is no evidence to indicate that E-collar training is necessary, even for its most widely cited indication.

The welfare consequences and efficacy of training pet dogs with remote electronic training collars in comparison to reward based training.

This study investigated the welfare consequences of training dogs in the field with manually operated electronic devices (e-collars). Following a preliminary study on 9 dogs, 63 pet dogs referred for recall related problems were assigned to one of three Groups: Treatment Group A were trained by industry approved trainers using e-collars; Control Group B trained by the same trainers but without use of e-collars; and Group C trained by members of the Association of Pet Dog Trainers, UK again without e-collar stimulation (n = 21 for each Group). Dogs received two 15 minute training sessions per day for 4-5 days. Training sessions were recorded on video for behavioural analysis. Saliva and urine were collected to assay for cortisol over the training period. During preliminary studies there were negative changes in dogs' behaviour on application of electric stimuli, and elevated cortisol post-stimulation. These dogs had generally experienced high intensity stimuli without pre-warning cues during training. In contrast, in the subsequent larger, controlled study, trainers used lower settings with a pre-warning function and behavioural responses were less marked. Nevertheless, Group A dogs spent significantly more time tense, yawned more often and engaged in less environmental interaction than Group C dogs. There was no difference in urinary corticosteroids between Groups. Salivary cortisol in Group A dogs was not significantly different from that in Group B or Group C, though Group C dogs showed higher measures than Group B throughout sampling. Following training 92% of owners reported improvements in their dog's referred behaviour, and there was no significant difference in reported efficacy across Groups. Owners of dogs trained using e-collars were less confident of applying the training approach demonstrated. These findings suggest that there is no consistent benefit to be gained from e-collar training but greater welfare concerns compared with positive reward based training.

Testing resource value in group-housed animals: an investigation of cage height preference in laying hens.

To avoid unpredictable social effects, animals' behavioural priorities are almost always tested using individuals housed singly, yet many species kept commercially are social animals housed in groups. Our aim was to develop a method of investigating environmental preference in group-housed laying hens, Gallus gallus domesticus, that maximised the external validity of our findings. In a simple test of preference, eight groups of ten hens were given free choice between furnished cages with minimum heights of 38 cm (low) and 45 cm (high). A preference for one cage height over the other would be evident as a shift from a binomial distribution of flock sizes in the two cages. No height preference was found as hens distributed evenly between the two cages more frequently than was expected. This suggests at high stocking densities maximising average inter-individual distance could be a priority over increased cage height. In a second experiment, to investigate the value that hens placed on a change in cage height; a 'cost' in the form of a narrow gap was imposed on movement from a low or high start cage to a high or low target cage, respectively. Cage height did not influence the latency of the first three hens to enter the target cage. However, latencies for subsequent hens were shorter and more hens worked to access a high target cage than a low target cage. We suggest that titrating animals' willingness to tolerate higher stocking densities against access to a resource could be an effective way to compare responses of group-housed animals to resources that are expected to satisfy the same motivational state.