Timings and interactions of skilled musicians

We report here a preliminary study of interactive behavior between two members of a skilled string quartet performing a selected musical passage that required both performers to play several hundred notes in rapid succession at a steady tempo and in synchrony. Bowing movements were recorded using angular velocity sensors attached to their right forearms. The results show a high degree of temporal precision in both players. In addition, both players exhibited embedded rhythmic components in their timekeeping pattern, which arose from the grouping of notes in the musical score: four 16th notes to a beat. Within each group of four notes, we found a consistent timing microstructure: alternate upbows and alternate downbows had different mean durations. Both players’ bowings could be modeled as alternating renewal processes. In addition, we report evidence of interactive coupling between the players as an essential component of their joint performance. The alternating renewal model enables us to propose a note-generation process that has implications for the central generators underlying the observed behavior and their hierarchical organization. We discuss the implications of this model for the organization and execution of more complex motor sequences.     

Lawnmower injuries in children.

Over an 8-year period 31 children in the Winnipeg area were admitted to hospital with lawnmower injuries. The accidents were always preventable and were caused by patient or parent carelessness. The wounds were severe, often resulting in amputation of a portion of an extremity. Infection was common; prophylaxis with a broad-spectrum antibiotic and human antitetanus globulin is recommended. Radiography, débridement of the wound with thorough exploration under general anesthesia, and defatting and reapplication of degloved skin should be done initially, then the wound should be reinspected and redressed at 2 to 3 days, and finally closed or skin grafted at 6 to 8 days. Children must be educated about the dangers of lawnmowers and prevented from riding on tractor mowers. The grass catcher should be used and the path cleared of missiles. Hand controls should be mounted on the mower''s handle and the blade should be kept sharp so that the machine''s speed can be reduced.     

Drain-cover injuries in children.

This report highlights unnecessary injuries to the hands, forearms, and feet of small children, caused by falling drain-cover gratings, colloquially known as "shores". It is suggested that a simple locking device, similar to that employed on manhole covers, would eliminate this type of injury.     

Auger injuries in children.

A 6-year review of auger injuries in Manitoba children revealed that 23 children sustained major injuries resulting in amputation of 17 limbs. Auger injuries are the main cause of traumatic amputation in children in Manitoba. Improved safety education for the entire farm family as well as better design of safety shields would decrease this carnage.