Shahin Rouhani

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We derive a formula giving the frequency with which random drift shifts a population between alternative equilibria. This formula is valid when such shifts are rare (Ns much greater than 1), and applies over a wide range of mutation rates. When the number of mutations entering the population is low (4 N mu much less than 1), the rate of stochastic shifts(More)
We show that the asymptotic symmetry algebra of geometries with Schrödinger isometry in any dimension is an infinite dimensional algebra containing one copy of Virasoro algebra. It is compatible with the fact that the corresponding geometries are dual to non-relativistic CFTs whose symmetry algebra is the Schrödinger algebra which admits an extension to an(More)
The structure of an early M-intermediate of the wild-type bacteriorhodopsin photocycle formed by actinic illumination at 230 K has been determined by x-ray crystallography to a resolution of 2.0 A. Three-dimensional crystals were trapped by illuminating with actinic light at 230 K, followed by quenching in liquid nitrogen. Amide I, amide II, and other(More)
Waking and sleep states were studied in the alcohol-dependent rat after administration of ethanol (416 mg/kg/hr) by indwelling intragastric catheter (IGC) for 13 days. Electropolygraphic recordings performed for a total of 24 hr from the start of withdrawal were compared with those of control rats receiving water by IGC and showed 1) that rapid eye movement(More)
Sleep-wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. In the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg).(More)
In a feedforward network of integrate-and-fire neurons, where the firing of each layer is synchronous (synfire chain), the final firing state of the network converges to two attractor states: either a full activation or complete fading of the tailing layers. In this article, we analyze various modes of pattern propagation in a synfire chain with random(More)
Correlations between cerebral monoamine metabolism and electrophysiological parameters were compared in 18 male Wistar rats subjected to a magnesium-restricted diet and in 14 normal rats. During the 40-day experimental period, plasma and erythrocyte Mg2+ levels and plasma Ca2+ and phosphorus levels were measured, and electroencephalographic tracings as well(More)
Three polygraphic recordings (PGR) of afternoon sleep (ANS) related to the duration of one sleep cycle, i.e., 90 min, were performed in 14 healthy adult volunteers (7 men and 7 women): two reference PGR, on two consecutive days (before ingestion of alcohol). Only the second being retained: reference PGR = P1; another recording, on day 3, 50 min after the(More)
We show that in the continuum limit watersheds dividing drainage basins are Schramm-Loewner evolution (SLE) curves, being described by one single parameter κ. Several numerical evaluations are applied to ascertain this. All calculations are consistent with SLE(κ), with κ = 1.734 ± 0.005, being the only known physical example of an SLE with κ<2. This lies(More)
It is shown that long term behavior of two connected Integrate- and- Fire neurons with excitatory synapses is determined by some fixed-points. In the case of equal synaptic weights four different dynamic phases are found. Between these phases there is a specific phase with a global attractor fixed-point, which is of interest from different viewpoints.(More)