Neurons spike when their membrane potential exceeds a threshold value. In central neurons, the spike threshold is not constant but depends on the stimulation. Thus, input-output properties of neurons depend both on the effect of presynaptic spikes on the membrane potential and on the dynamics of the spike threshold. Among the possible mechanisms that may modulate the threshold, one strong candi...

Gravimetric and geologic data show that the reactivation of the Neogene Interandean depression and/or the ~75 65 Ma ophiolite suture into the modern dynamic of the Andes controlled the Gulf of Guayaquil Tumbes basin (GGTB) location and evolution during the past 1.8 1.6 Myr at least. Depending on whether the remobilization occurred along the interandean depression or the ophiolite suture, the GG...

The mean ̄ow at and around the Hebrides and Shetland Shelf slope is measured with ARGOS tracked drifters. Forty-two drifters drogued at 50 m were deployed in three circles over the Hebrides slope at 56.15°N in two releases, one on 5th December, 1995 and the second on 5±9th May, 1996. The circles span a distance of some 20 km from water depths of 200 m to 1200 m. Drifters are initially advected ...

abstract study of turbidity current hydrodynamics plays an important role in increasing the economical life of dams though reduction in sediment accumulation. in the present experimental study, the effect of entrance densimetric froude number of turbidity current in sub and super critical conditions (fr =0.6-3.5) have been tested through effect of channel slope and change related to opening hei...

6 [1] Gravel-bedded channels often become incised and degraded below dams. Gravel can 7 be added to the channel to rehabilitate hydrogeomorphic conditions, including those 8 promoting salmon spawning. When implemented without increasing bed slope, gravel 9 addition at downstream riffles back floods upstream riffles. A 2-year gravel augmentation 10 project was done to test the efficacy of a new ...

The European “Slope Current” provides a shelfedge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Curr...

multicast routing is one of the most important services in multi radio multi channel (mrmc) wireless mesh networks (wmn). multicast routing performance in wmns could be improved by choosing the best routes and the routes that have minimum interference to reach multicast receivers. in this paper we want to address the multicast routing problem for a given channel assignment in wmns. the channels...

many appealing multicast services such as on-demand tv, teleconference, online games and etc. can benefit from high available bandwidth in multi-radio multi-channel wireless mesh networks. when multiple simultaneous transmissions use a similar channel to transmit data packets, network performance degrades to a large extant. designing a good multicast tree to route data packets could enhance the...

Ca2+ entry under resting conditions may be important for contraction of vascular smooth muscle, but little is known about the mechanisms involved. Ca2+ leakage was studied in the A7r5 smooth muscle-derived cell line by patch-clamp techniques. Two channels that could mediate calcium influx at resting membrane potentials were characterized. In 110 mM Ba2+, one channel had a slope conductance of 6...

Sinuous patterns traced by fluid flows are a ubiquitous feature of physical landscapes on Earth, Mars, the volcanic floodplains of the Moon and Venus, and other planetary bodies. Typically discussed as a consequence of migration processes in meandering rivers, sinuosity is also expressed in channel types that show little or no indication of meandering. Sinuosity is sometimes described as "inher...