We review a statistical mechanics treatment of the stability of globular proteins based on a simple model Hamiltonian taking into account protein self-interactions and protein–water interactions. The model contains both hot and cold folding transitions. In addition it predicts a critical point...

Biopolymers have many fascinating properties coming from a competition between universal features, well known in the physics of synthetic polymers, and specific elements which are crucial for the biological function of these molecules. Proteins are an example of this richness: proteins are...

The waiting time needed for a stock market index to undergo a given percentage change in its value is found to have an up-down asymmetry, which, surprisingly, is not observed for the individual stocks composing that index. To explain this, we introduce a market model consisting of randomly...

The value of stocks, indices and other assets, are examples of stochastic processes with unpredictable dynamics. In this paper, we discuss asymmetries in short term price movements that can not be associated with a long term positive trend. These empirical asymmetries predict that stock index...

By applying inverse statistics to financial data it has recently been found from empirical studies that indices exhibit a pronounced gain-loss asymmetry [M.H. Jensen, Phys. Rev. Lett. 83 (1999) 76; I. Simonsen, M.H. Jensen, A. Johansen, Eur. Phys. J. B 27 (2002) 583; M.H. Jensen, A. Johansen, I....

We propose a simple market model where agents trade different types of products with each other by using money, relying only on local information. Value fluctuations of single products, combined with the condition of maximum profit in transactions, readily lead to persistent fluctuations in the...

We consider directed percolation with an absorbing boundary in 1 + 1 and 2 + 1 dimensions. The distribution of cluster lifetimes and sizes depend on the boundary. The new scaling exponents can be related to the exponents characterizing standard directed percolation 1 + 1 dimension. In addition,...

We explain the physical basis of a very simple hierarchical model for small globular proteins with water interactions. The water is supposed to accesses the protein interior in an “all-or-none” manner during the unfolding of the protein chain. As a consequence of this mechanism (somewhat...

We present results from a visualization experiment in Rayleigh-Bénard convection in water at high Rayleigh number. We distinguish three kinds of coherent structures in the flow: waves along the boundary layers, plumes, and spiraling swirls. The waves originate from the interaction of plumes...

In recent publications, the authors have considered inverse statistics of the Dow Jones Industrial Averaged (DJIA). Specifically, we argued that the natural candidate for such statistics is the investment horizons distribution. This is the distribution of waiting times needed to achieve a...