We present in this paper a new inverse method for the study of the seepage from symmetrical earthen open channels. We map the half-strip from the complex potential domain onto the unit half-disk from an auxiliary ζ plane. We introduce Levi-Civitá’s function whose imaginary part vanishes on the diameter [−1, 1] of the half-disk by virtue of the boundary conditions imposed on the free lines. Then...

AIM To study the effects of tetrandrine (Tet) on the changes of NMDA receptor channels in cortical neurons induced by anoxia. METHODS Cell-attached configuration of patch-clamp techniques. Anoxia was produced by perfused cells with 95% N2 + 5% CO2 gassed bath solution. RESULTS During anoxia, the open time constant (tau 2), open probability (Po) of 35-pS and 100-pS channels increased. Tet 7....

The occupancy of the orthosteric ligand binding sites of P2X receptor (P2XR) channels causes the rapid opening of a small cation-permeable pore, followed by a gradual dilation that renders the pore permeable to large organic cations. Electrophysiologically, this phenomenon was shown using whole-cell current recording on P2X2R-, P2X2/X5R-, P2X4R- and P2X7R-expressing cells that were bathed in N-...

Ion channels are integral membrane proteins that are critical for neuronal function. They form pores in the plasma membrane that allow certain ions to travel with their concentration gradient across the membrane. Those that open in response to a change in membrane potential are called voltage-gated ion channels. Channels that open in response to binding by a chemical signal or molecule are liga...

In this paper we present a simple cumulative sum algorithm for detection of leaks in open water channels. The algorithm compares the observed changes in water levels against the known inand out-flows and raises an alarm if they are not in agreement. The algorithm is tested on data from an irrigation channel with very good results. Leaks are quickly detected and the algorithm is robust against u...

Rating curves relating stream discharge to water-surface stage are traditionally established empirically through many measurements of discharge and concurrent stage. However, discharge measurements typically scatter and do not show a unique relation to the stage because the underlying physics are usually not reflected in the rating. Examining the relationship of stage versus discharge in open c...

Surgical attitudes to blood vessels through the millennia and leading up to the middle of the twentieth century were, with anecdotal exceptions, limited to life-saving cautery or ligation. The practice of vascular surgery was initiated only in the fifties when arteries and veins-these vasa vitae or vessels of life-were deliberately sought out and reconstructed. Keeping the channels open in orde...

HCN (hyperpolarization-activated cyclic nucleotide gated) pacemaker channels have an architecture similar to that of voltage-gated K(+) channels, but they open with the opposite voltage dependence. HCN channels use essentially the same positively charged voltage sensors and intracellular activation gates as K(+) channels, but apparently these two components are coupled differently. In this stud...

Voltage-dependent K+ channels like Shaker use an intracellular gate to control ion flow through the pore. When the membrane voltage becomes more positive, these channels traverse a series of closed conformations before the final opening transition. Does the intracellular gate undergo conformational changes before channel opening? To answer this question we introduced cysteines into the intracel...

Horizontal cells form an electrically coupled network for the transmission of inhibitory signals in the outer retina. In teleosts, horizontal cell coupling is modulated by the neurotransmitter dopamine. Using voltage-clamped pairs of teleost horizontal cells, we have examined the effects of dopamine on the conductance and gating properties of the cell-to-cell channels that mediate electrical sy...