A novel method for synchronizing motion capture with other data sources for millisecond-level precision.

Synchronization of multiple data collection systems is necessary for accurate temporal alignment of data, and is particularly important when considering rapid movements which occur in less than one second. This paper describes a novel method for synchronizing multiple data collection instruments including load cells and a motion capture system, using a common analog signal. An application of the synchronization method is demonstrated using biomechanical data collected during a rapid reach-to-grasp reaction, where data from motion capture and load cells are collected. Results are provided to validate and demonstrate the accuracy of the synchronization of motion capture with other data collection systems. During the reach-to-grasp trials, delays between the data collection systems ranged from 4ms to 235ms. The large range and variability in delay times between trials highlights the need for synchronization on a continual basis, rather than application of an average or constant value to correct for time delays between systems.

The Sea Empress oil spill (Wales, UK): effects on Common Scoter Melanitta nigra in Carmarthen Bay and status ten years later.

Carmarthen Bay, UK, regularly supports internationally important numbers (>16,000) of non-breeding Common Scoters Melanitta nigra. The spill of 72,000 tonnes of crude oil from the Sea Empress in 1996 affected birds both through direct mortality and likely pollution of key food resources. Numbers were greatly reduced following the spill, whilst changes in the distribution of birds within Carmarthen Bay suggested that potentially sub-optimal foraging zones were used. However, ten years after the incident, numbers of Common Scoter were no different to those recorded immediately before the spill. Compared to some other spills, rapid revival is evident. Numbers increased to pre-spill levels within three winters and distributional changes suggested a concurrent return to previously contaminated feeding areas, implying that the ecosystem had regenerated sufficiently to support its top predator. The importance of prolonged, standardised monitoring of bird numbers and distribution as indicators of ecological recovery from environmental damage is emphasised.