Delays in blood collection and drug toxicology results among crash-involved drivers arrested for impaired driving.

Objective: The concentration of drugs in a driver's system can change between an impaired driving arrest or crash and the collection of a biological specimen for drug testing. Accordingly, delays in specimen collection can result in the loss of critical information that has the potential to affect impaired driving prosecution. The objectives of the study were: (1) to identify factors that influence the time between impaired-driving violations and specimen collections (time-to-collection) among crash-involved drivers, and (2) to consider how such delays affect measured concentrations of drugs, particularly with respect to common drug per se limits.

A binary method for simple and accurate two-dimensional cursor control from EEG with minimal subject training.

Background: Brain-computer interfaces (BCI) use electroencephalography (EEG) to interpret user intention and control an output device accordingly. We describe a novel BCI method to use a signal from five EEG channels (comprising one primary channel with four additional channels used to calculate its Laplacian derivation) to provide two-dimensional (2-D) control of a cursor on a computer screen, with simple threshold-based binary classification of band power readings taken over pre-defined time windows during subject hand movement.

Methods: We tested the paradigm with four healthy subjects, none of whom had prior BCI experience.

Mechanisms underlying reversal of motor unit activation order in electrically evoked contractions after spinal cord injury.

Extracellular stimulation normally activates larger-diameter axons, innervating motor units producing higher force, at lower stimulation intensities than required to activate small-diameter axons innervating motor units producing low force. However, activation of weaker thenar motor units at lower stimulation intensities than required to activate strong motor units has been reported during extracellular stimulation of the median nerve in persons with chronic cervical spinal cord injury. We used a computational model that reproduced this experiment to identify the potential mechanisms for the observed reversal of the inverse recruitment order, including preferential death of large motoneurons, demyelination and remyelination, and denervation and reinnervation of muscle fibers.