Trainability of novel person recognition based on brief exposure to form and motion cues

Fast and accurate recognition of teammates is crucial in contexts as varied as fast-moving sports, the military, and law enforcement engagements; misrecognition can result in lost scoring opportunities in sport or friendly fire in combat contexts. Initial studies on teammate recognition in sport suggests that athletes are adept at this perceptual ability but still susceptible to errors. The purpose of the current proof-of-concept study was to explore the trainability of teammate recognition from very brief exposure to vision of the whole-body form and motion of a previously unknown individual. Participants were divided into three groups: a 4-week training group who were also the actors for the test and training footage, a 2-week training group, and a no-training group. Findings revealed significant differences between the training groups and their improvement from the pre-to post-test on Response Accuracy and Movement Time. The current study found the best performance in the 4-week Training group. The biggest improvement was found in the 2-week training group, whilst no significant improvement was made in the Control group. These results suggest that training was effective, but also indicate that having initially performed the movements as actors may have led to improvements in baseline testing and ultimately the best results, thus physical performance of skills combined with video-based training may reduce the amount of time needed to improve teammate identification.

Flow cytometric HLA-B27 typing using CD3 gating and molecules of equivalent soluble fluorochrome (MESF) quantitation

The determination of HLA-B27 (B27) status is important in the diagnosis of ankylosing spondylitis, Reiter's disease, and other arthropathies. Flow cytometric (FCM) typing of B27 is a relatively new method which allows for rapid turnaround time and low cost. However, different leukocyte populations may manifest significant variation in staining intensity with B27 antibodies. Therefore, gating utilizing only light scatter properties of cells may lead to high readings in some B27-negative samples. Fluorescence gating on CD3+ cells were postulated as a means to eliminate these anomalies. Furthermore, quantitative FCM measurements, as afforded through use of molecules of equivalent soluble fluorochrome (MESF) units, can minimize day-to-day and instrument-to-instrument variabilities in fluorescence measurements. We compared CD3 gating to light scatter gating and MESF analysis on 123 specimens in a 4-month period and found: 1) CD3 gating gave the lowest nonspecific B27 antibody binding among B27-negative subjects; 2) there was no significant difference in MESF values between CD3 gating and light scatter gating of B27-positive samples; 3) there was a wide range of B27 antibody binding fluorescence intensities among B27-positive subjects; 4) identification of patients with low B27 expression may require the use of CD3 gating in order to avoid costly confirmation testing; 5) fluorescent standard beads are stable for routine use in a clinical flow cytometry laboratory.