High-frequency oscillations in the beta range (10-45 Hz) are most active in motor cortex during motor preparation and are postulated to reflect the steady postural state or global attentive state of the animal. By simultaneously recording multiple local field potential signals across the primary motor and dorsal premotor cortices of monkeys (Macaca mulatta) trained to perform an instructed-delay reaching task, we found that these oscillations propagated as waves across the surface of the motor cortex along dominant spatial axes characteristic of the local circuitry of the motor cortex. Moreover, we found that information about the visual target to be reached was encoded in terms of both latency and amplitude of evoked waves at a time when the field phase-locked with respect to the target onset. These findings suggest that high-frequency oscillations may subserve intra- and inter-cortical information transfer during movement preparation and execution.

DNA microarrays have demonstrated an excellent potential in correlating specific gene expression profiles to specific conditions. However, they are affected by inherent noise. This paper presents a two-stage approach for noise removal that processes the additive and the multiplicative noise component. The proposed approach first decomposes the signal by a multiresolution transform and then accounts for both the multiscale correlation of the subband decompositions and their heavy-tailed statistics. Real microarray images have been processed by the proposed method and its improved performance is shown through quantitative measures and qualitative visual evaluation.

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