Structure determination of the reconstructed Au(110) surface

The LEED pattern of the Au(110) surface shows a (1 × 2) and also a (1× 3) superstructure. The (1 × 2) superstructure has been determined by comparison of LEED intensities with model calculations. The missing row model is the most probable model. A minimum of the averaged r-factor, , has been found for 15% contraction of the first layer spacing without atomic displacements in the second layer

Detecting multineuronal temporal patterns in parallel spike trains

We present a non-parametric and computationally efficient method that detects spatiotemporal firing patterns and pattern sequences in parallel spike trains and tests whether the observed numbers of repeating patterns and sequences on a given timescale are significantly different from those expected by chance. The method is generally applicable and uncovers coordinated activity with arbitrary precision by comparing it to appropriate surrogate data. The analysis of coherent patterns of spatially and temporally distributed spiking activity on various timescales enables the immediate tracking of diverse qualities of coordinated firing related to neuronal state changes and information processing. We apply the method to simulated data and multineuronal recordings from rat visual cortex and show that it reliably discriminates between data sets with random pattern occurrences and with additional exactly repeating spatiotemporal patterns and pattern sequences. Multineuronal cortical spiking activity appears to be precisely coordinated and exhibits a sequential organization beyond the cell assembly concept

Aggregate liquidity shortages, idiosyncracic liquidity smoothing and banking regulation

This paper develops a model of banking fragility driven by aggregate liquidity shortages. Inefficiencies arise because liquidity smoothing across banks breaks down when there is such a shortage, causing unnecessary and value-reducing transfer of assets between banks. We find that a Lender of Last Resort policy is ineffective in restoring efficiency as it leads to offsetting changes in the banks’ supply of liquidity. In contrast, subsidizing the purchase of assets from troubled banks increases welfare by improving the banks’ liquidity holdings. The first best, however, is achieved by redistributing liquidity from healthy to troubled banks in a crisis

The Parametric Solution of Underdetermined linear ODEs

The purpose of this paper is twofold. An immediate practical use of the presented algorithm is its applicability to the parametric solution of underdetermined linear ordinary differential equations (ODEs) with coefficients that are arbitrary analytic functions in the independent variable. A second conceptual aim is to present an algorithm that is in some sense dual to the fundamental Euclids algorithm, and thus an alternative to the special case of a Groebner basis algorithm as it is used for solving linear ODE-systems. In the paper Euclids algorithm and the new `dual version' are compared and their complementary strengths are analysed on the task of solving underdetermined ODEs. An implementation of the described algorithm is interactively accessible under http://lie.math.brocku.ca/crack/demo.Comment: 14 page