In crowded visual scenes, attention is needed to select relevant stimuli. To study the underlying mechanisms, we recorded neurons in cortical area V4 while macaque monkeys attended to behaviorally relevant stimuli and ignored distracters. Neurons activated by the attended stimulus showed increased gamma-frequency (35 to 90 hertz) synchronization but reduced low-frequency (<17 hertz) synchroniza...

Six men were subjected to 3500 Hertz pure tones of 1250 millisecond pulse length repeated every 2. 5 seconds for a period of 15 minutes at Sound Pressure Levels of 168 and 178 decibels re .0002 dynes per square centimeter. Temporary Threshold Shifts were measured and compared to temporary threshold shifts induced by similar exposures at lower levels in air in a second group of five men. It was ...

nerve was performed, with the active surface recording electrode over the midportion of the abductor digiti minimi muscle. The CMAP at rest was compared with the highest amplitude CMAP on stimulation. On the third hospital day supramaximal stimulation at 3 Hertz gave an increment of 18%, and stimulation at 50 Hertz gave an abnormal incremental response of 81% (normal mean increment = 2-4%; uppe...

We observed robust coupling between the high- and low-frequency bands of ongoing electrical activity in the human brain. In particular, the phase of the low-frequency theta (4 to 8 hertz) rhythm modulates power in the high gamma (80 to 150 hertz) band of the electrocorticogram, with stronger modulation occurring at higher theta amplitudes. Furthermore, different behavioral tasks evoke distinct ...

Bimodal atomic force microscopy uses a cantilever that is simultaneously driven at two of its eigenmodes (resonant modes). Parameters associated with both resonances can be measured and used to extract quantitative nanomechanical information about the sample surface. Driving the first eigenmode at a large amplitude and a higher eigenmode at a small amplitude simultaneously provides four indepen...

Robert Hertz’ s foundational contribution to the sociology of death is as strikingly fresh today as when ® rst published in 1907 when Hertz, born in 1881 and killed in active service in 1915, was but 26 years old. It remained largely unknown to English speaking social science for some 50 years and increased in signi® cance only after its English translation of 1960. It now stands as a basic his...

Six men were subjected to 3500 Hertz pure tones of 1250 millisecond pulse length repeated every 2. 5 seconds for a period of 15 minutes at Sound Pressure Levels of 168 and 178 decibels re .0002 dynes per square centimeter. Temporary Threshold Shifts were measured and compared to temporary threshold shifts induced by similar exposures at lower levels in air in a second group of five men. It was ...

A small-scale flexure-based gripper was designed for manipulation tasks requiring precision position and force control. The gripper is actuated by a piezoelectric ceramic stack actuator and utilizes strain gages to measure both the gripping force and displacement. The position and force bandwidths were designed for ten Hertz and one hundred Hertz, respectively, in order to afford human-based te...

In this paper, we consider the problem of determining whether or not a directed graph contains a pair of vertices connected by two distinct simple paths; if it does not, we say it is singly connected. A straightforward implementation using n depth rst searches requires O(nm) time on an n-vertex, m-arc digraph; we obtain an O(n) time algorithm by using contraction wherever possible. Supported by...