Differential treatment of bipolar disorder with old and new antiepileptic drugs

Although lithium remains the preferred medication for bipolar disorders, new investigations suggest that only 60 to 80% of patients have a good response with a classical presentation. The antiepileptics carbamazepine and valproate are important alternatives. Several studies have shown that lithium, carbamazepine and valproate are effective in pure mania. Mixed mania and rapid cycling respond, however, well to valproate. One disadvantage of carbamazepine is its enzyme inducing property with the consequence of a decrease of plasma levels of other psychotropic medications and a worsening of psychopathology. First data indicate a good antimanic and antidepressive efficacy of the new antiepileptic drug lamotrigine

Do Buyer-Size Discounts Depend on the Curvature of the Surplus Function? Experimental Tests of Bargaining Models

A number of recent theoretical papers have shown that for buyer-size discounts to emerge in a bargaining model, the total surplus function over which parties bargain must have certain nonlinearities. We test the theory in an experimental setting in which a seller bargains with a number of buyers of different sizes. We generate nonlinearities in the surplus function by varying the shape of the seller's cost function. Our results strongly support the theory. As predicted, large-buyer discounts emerge only in the case of increasing marginal cost, corresponding to a concave surplus function.buyer-size discounts, large buyer, experimental economics.

Tune Correction for the SPS Ramp

The tune corrections applied in the ramp for a large palette of SPS cycle used in 2007 has been analyzed to evaluate the reproducibility and the dependence on the supercycle composition. The data highlights the excellent reproducibility of the SPS tune above momenta of 50~GeV/c, with little dependence on the injection momentum or the ramp speed. Difference are concentrated at lower momenta, but for similar cycles, the corrections are very reproducible and show only a small dependence on the supercycle composition. The data also underlines the positive impact on fixed target beams of the improvement in the tracking of the main power converters of the SPS that was obtained by reducing the point spacing in the ramp from 30~ms to 6~ms

Роздуми про розвиток фізики у ХХІ столітті

We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm à la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to bundle. We also contrast the simultaneous and the sequential order of moves in the duopoly market. Our data indicate support for the theory of product bundling: with bundling and simultaneous moves, the multi-product firm offers the predicted number of units. When the multi-product firm is the Stackelberg leader, the predicted equilibrium is better attained with bundling, especially when it chooses to bundle, even though in theory bundling should not make a difference here. In sum, bundling works as a commitment device that enables the transfer of market power from one market to another

Neural interface for a cortical vision prosthesis

Journal ArticleThe development of a cortically based vision prosthesis has been hampered by a lack of basic experiments on phosphene psychophysics. This basic research has been hampered by the lack of a means to safely stimulate large numbers of cortical neurons. Recently, a number of laboratories have developed arrays of silicon microelectrodes that could enable such basic studies on phosphene psychophysics. This paper describes one such array, the Utah electrode array, and summarizes neurosurgical, physiological and histological experiments that suggest that such an array could be implanted safely in visual cortex. We also summarize a series of chronic behavioral experiments that show that modest levels of electrical currents passed into cortex via this array can evoke sensory percepts. Pending the successful outcome of biocompatibility studies using such arrays, high count arrays of penetrating microelectrodes similar to this design could provide a useful tool for studies of the psychophysics of phosphene perception in human volunteers. Such studies could provide a proof-of-concept for cortically based artificial vision

Functional reorganization of primary visual cortex induced by electrical stimulation in the cat.

Journal ArticleCompared to the high degree of plasticity observed in a juvenile, mature sensory cortices have long been held to be immutable but, recently, researchers have suggested some plasticity persists in the mature cortex. Cortical reorganization has particular saliency to the development of a cortically based, sensory neuroprosthesis, which will chronically evoke activity through electrical stimulation. We have examined the nature and extent of the reorganization induced by electrical stimulation. We found the receptive field size and synaptic efficacy can be increased, particularly for neurons near the stimulation site. As the changes are minimal, these results are not expected to impact neuroprosthetic applications

Fractional-Power-Law Level-Statistics due to Dynamical Tunneling

For systems with a mixed phase space we demonstrate that dynamical tunneling universally leads to a fractional power law of the level-spacing distribution P(s) over a wide range of small spacings s. Going beyond Berry-Robnik statistics, we take into account that dynamical tunneling rates between the regular and the chaotic region vary over many orders of magnitude. This results in a prediction of P(s) which excellently describes the spectral data of the standard map. Moreover, we show that the power-law exponent is proportional to the effective Planck constant h.Comment: 4 pages, 2 figure

Dipole Field, Tune and Chromaticity Correction at the SPS: from Converter Tracking to Eddy Currents

Good control of key parameters like dipole field, tune and chromaticity is a basic requirement for fast cycle commissioning and for good beam transmission through the SPS ramp. The reproducibility of those parameters depends on power converter tracking, eddy currents and remnant fields. The new SPS control system was used to study some of the problems in the low energy ramp segment of the fixed target beam. A small modification of the function generation for the main converters is shown to reduce residual converter tracking errors by more than one order of magnitude. Tune and chromaticity corrections have been analyzed and summarized for different cycles, both for the ramp as well for the injection plateau where eddy current may play a significant role