No abstract

The concept that golf clubs should have a uniform weight distribution means that manufacturers invest significant time and money tailoring the swingweight of their clubs. If golfers are unable to perceive significant changes in swingweight, however, and the effect of swingweight on club performance is small, the current manufacturing tolerances on swingweight can be widened, allowing time and cost savings in the assembly process. Testing was conducted using 30 skilled golfers each performing ten tee-shots with four differently weighted drivers. Clubhead mass was varied using screwed inserts of different known masses and the effects on impact location and clubhead speed were both measured. Changes to golf club weight distribution, measured using the swingweight concept, were found to have little effect on player performance and, in general, golfers were unable to perceive small changes in club swingweight. Manufacturing tolerances for component masses appear to offer sufficient control over golf club weight distribution, suggesting that mass balancing procedures may be relaxed during club assembly to provide production time and cost savings.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) potentiates in vitro and in vivo production of granulocytes. Also, recombinant human GM-CSF in vitro enhances functional capabilities of human granulocytes. Recombinant murine (rm) GM-CSF was administered to neonatal rats in vivo to test its ability to protect from septic death due to Staphylococcus aureus. When rmGM-CSF was given intraperitoneally 6 h before a 90% lethal dose challenge of S. aureus, peak survival was observed at a dose of 30 pg/g (54% vs. 10% in animals administered saline; P less than .001). Blood cultures were positive for S. aureus in 26 of 32 saline-treated and in 5 of 31 rmGM-CSF-treated animals (P less than .001). Numbers of blood granulocytes were significantly increased 9 h after administration of rmGM-CSF (30 pg/g) but returned to control levels by 12 h. Neither neutrophil storage nor proliferative pools were affected. Thus, rmGM-CSF significantly improved survival when given prophylactically in a neonatal rat model of infection.

No abstract

Golf swing machines have become fundamental tools in the development of new equipment because they provide more consistent swing motions than golfers. Golf robots perform a simplification of the complex sequence of motions that compose a golf swing; however, traditional devices are typically capable of performing only a single swing profile at variable speeds. Significant differences exist between individual golfers' swing motions, especially for golfers of different ability, experience, and physical stature, which suggests a requirement for swing profile variability in mechanical simulators. This investigation has found that the swing motion of a traditional golf robot provides a poor representation of golfers' swings and, as a result, a bespoke control system has been developed for a commercially available golf robot to enable performance of variable swing profiles with positional feedback. Robot swing command files are generated by fitting a curve to a number of discrete data points that are equally spaced in time, and which define angles representative of individual golfers' swings. The swing profiles of a professional golfer and a traditional golf robot were repeated accurately using this golf robot with a modified motion control system. The capability for individual golfers' swings to be accurately replicated using a mechanical device was demonstrated using feedback data. All manufacturers recognize the importance of tailoring equipment to the unique characteristics of a particular golfer's swing, and this increased robot functionality will provide considerable benefits in the development of customized equipment.