Tactile sensitivity thresholds were determined using monofilament force detection and the tactile discrimination level was obtained in the direction discrimination of a moving probe; both tasks readily activate myelinated touch receptors. Perceptions were measured over five skin sites: forehead, arm, palm, thigh and shin. The assessment Epigenetics inhibitor of tactile pleasantness over the skin resulted in a preference for the middle velocities (1-10 cm s(-1)), where higher ratings were gained compared to the slowest and fastest velocities. This preference in

tactile pleasantness was found across all the skin sites, apart from at the palm, where no decrease in pleasantness for the faster stroking velocities was seen. We find that tactile sensitivity and discrimination this website vary across the skin, where the forehead and palm show increased acuity. Tactile sensitivity and discrimination levels also correlated significantly, although the tactile acuity did not relate to the perceived

pleasantness of touch. Tactile pleasantness varied in a subtle way across skin sites, where the middle velocities were always rated as the most pleasant, but the ratings at hairy skin sites were more receptive to changes in stroking velocity. We postulate that although the mechanoreceptive afferent physiology may be different over the skin, the perception of pleasant touch can be interpreted using all of the available incoming somatosensory information in combination with central processing.”
“We present an electrokinetic framework for designing insulator constriction-based PP2 molecular weight dielectrophoresis devices with enhanced ability to trap nanoscale biomolecules in physiological media of high conductivity, through coupling short-range dielectrophoresis forces with long-range electrothermal flow. While a 500-fold constriction enables field focusing sufficient to trap nanoscale biomolecules by dielectrophoresis, the extent of this high-field region is enhanced through coupling the

constriction to an electrically floating sensor electrode at the constriction floor. However, the enhanced localized fields due to the constriction and enhanced current within saline media of high conductivity (1 S/m) cause a rise in temperature due to Joule heating, resulting in a hotspot region midway within the channel depth at the constriction center, with temperatures of similar to 8 degrees-10 degrees K above the ambient. While the resulting vortices from electrothermal flow are directed away from the hotspot region to oppose dielectrophoretic trapping, they also cause a downward and inward flow towards the electrode edges at the constriction floor. This assists biomolecular trapping at the sensor electrode through enabling long-range fluid sampling as well as through localized stirring by fluid circulation in its vicinity. (C) 2012 American Institute of Physics. [doi:10.1063/1.