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Our goal was to understand how patterns of excitation and inhibition, interacting across arrays of ganglion cells in space and time, generate the spiking output pattern for each ganglion cell type. We presented the retina with a 1-s flashed square, 600 microm on a side, and measured patterns of excitation and inhibition over an 1,800-microm-wide region(More)
Retinal bipolar cells can be divided into on and off types based on the polarity of their response to light. Bipolar activity is further shaped by inhibitory inputs, characterized here by the events that occur immediately after the onset of a light step: 1) in most off bipolar cells, excitatory current decreased, whereas inhibitory current increased. These(More)
—An ultra low power 2.4-GHz transceiver targeting wireless sensor network applications is presented. The receiver front-end is fully passive, utilizing an integrated resonant matching network to achieve voltage gain and interface directly to a passive mixer. The receiver achieves a 7-dB noise figure and 7.5-dBm IIP3 while consuming 330 W from a 400-mV(More)
In the mammalian retina, complementary ON and OFF visual streams are formed at the bipolar cell dendrites, then carried to amacrine and ganglion cells via nonlinear excitatory synapses from bipolar cells. Bipolar, amacrine and ganglion cells also receive a nonlinear inhibitory input from amacrine cells. The most common form of such inhibition crosses over(More)
A 900 MHz, ultra-low power RF transceiver is presented for wireless sensor networks. It radiates -6 dBm in transmit mode and has a receive sensitivity of -94 dBm while consuming less than 1.3 mW in either mode from a 3 volt battery. Two of these transceivers have been demonstrated communicating over 16 meters through walls at a bit rate of 20 kbps while(More)
We introduce a fast method, the &#x201C;in-crowd&#x201D; algorithm, for finding the exact solution to basis pursuit denoising problems. The in-crowd algorithm discovers a sequence of subspaces guaranteed to arrive at the support set of the final solution of <i>l</i><sub>1</sub> -regularized least squares problems. We provide theorems showing that the(More)