Jürgen Streit

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The image quality and compression ratio trade-oos of ve diierent 176 144 pels quarter common intermediate format (QCIF) fractal image codecs are investigated by simulation. The average peak signal-to-noise ratio (PSNR) ranges from 29 dB to 37 dB, while the coding rate from 0.24 bit/pel (bpp) to 1.22 bit/pel, as seen in Table 1. Two of the candidate co-decs,(More)
The inactivation of calcium currents during nerve growth factor (NGF)-induced differentiation of rat pheochromocytoma (PC12) cells was investigated. Whole cell calcium and barium currents were recorded in PC12 cells using the patch-clamp method. A shift of the steady-state inactivation curve towards more negative potentials, as well as an increase in the(More)
— Dual-mode reconfigurable wireless videophone transceivers are proposed for noise-, rather than interference-limited indoors and outdoors applications and their video quality, bit rate, robustness, and complexity issues are analyzed. A suite of fixed, but arbitrarily programmable low-rate, perceptually weighted vector quantized (VQ) codecs with and without(More)
The role of calcium currents in the regulation of neurite outgrowth is still rather speculative. As a contribution to this field, macroscopic voltage dependent calcium currents were investigated in relation to the nerve growth factor (NGF)-induced outgrowth of neurites in PC 12 cells. Calcium currents were recorded in isolated growth cones of PC 12 cells(More)
Whole-cell calcium and barium currents were recorded from PC12 cell bodies and growth cones during nerve growth factor (NGF)-induced neurite outgrowth. Depolarizing voltage steps were applied to activate the currents, and pharmacological agents were used to separate them from other ionic currents. In recordings from growth cones still attached to neurites,(More)