Equation of state of a granular gas homogeneously driven by particle rotations

We report an experimental study of a dilute "gas" of magnetic particles subjected to a vertical alternating magnetic field in a 3D container. Due to the torque exerted by the field on the magnetic moment of each particle, a spatially homogeneous and chaotic forcing is reached where only rotational motions are driven. This forcing differs significantly from boundary-driven systems used in most previous experimental studies on non equilibrium dissipative granular gases. Here, no cluster formation occurs, and the equation of state displays strong analogy with the usual gas one apart from a geometric factor. Collision statistics is also measured and shows an exponential tail for the particle velocity distribution. Most of these observations are well explained by a simple model which uncovers out-of-equilibrium systems undergoing uniform "heating".Comment: Europhysics Letters (2013) in pres

The antiplatelet activity of Aspirin

The synthesis of aspirin in the late nineteenth century marked the development of what was to become the most widely used household analgesic in the twentieth century. However, with the increased understanding of the major role of platelets in vascular occlusion over the last ten years, the importance of aspirin as an antiplatelet drug and, consequently, its applications in reducing the risks of thrombotic vascular events, have received major attention.peer-reviewe

Differential systems of pure Gaussian type

We give the transformation rule for the Stokes data of the Laplace transform of a differential system of pure Gaussian type.Comment: 31 pages. V2: final version to appear in Izv. Mat

Hypergeometric periods for a tame polynomial

We analyse the Gauss-Manin system of differential equations---and its Fourier transform---attached to regular functions satisfying a tameness assupmption on a smooth affine variety over C (e.g. tame polynomials on C^{n+1}). We give a solution to the Birkhoff problem and prove Hodge-type results analogous to those existing for germs of isolated hypersurface singularities.Comment: AMS-LaTeX with amsart.sty. Uses XY-pic package. 43 page

Measuring real value and inflation

The most important economic measures are monetary. They have many different names, are derived in different theories and employ different formulas. Yet, they all attempt to do basically the same thing: to separate a change in nominal value into a ‘real part’ due to the changes in quantities and an inflation due to the changes of prices. Examples are: real national product and its components, the GNP deflator, the CPI, various measures related to consumer surplus, as well as the large number of formulas for price and quantity indexes that have been proposed. The theories that have been developed to derive these measures are largely unsatisfactory. The axiomatic theory of indexes does not make clear which economic problem a particular formula can be used to solve. The economic theories are for the most part based on unrealistic assumption. For example, the theory of the CPI is usually developed for a single consumer with homothetic preferences and then applied to a large aggregate of diverse consumers with non-homothetic preferences. In this paper I develop a unitary theory that can be used in all situations in which monetary measures have been used. The theory implies a uniquely optimal measure which turns out to be the Törnqvist index. I review, and partly re-interpret the derivations of this index in the literature and provide several new derivations. The paper also covers several related topics, particularly the presently unsatisfactory determination of the components of real GDP