Macroscopic Floquet topological crystalline steel pump

The transport of a steel sphere on top of two dimensional periodic magnetic patterns is studied experimentally. Transport of the sphere is achieved by moving an external permanent magnet on a closed loop around the two dimensional crystal. The transport is topological i.e. the steel sphere is transported by a primitive unit vector of the lattice when the external magnet loop winds around specific directions. We experimentally determine the set of directions the loops must enclose for nontrivial transport of the steel sphere into various directions

Eluate derived by extracorporal antibody-based immunoadsorption elevates the cytosolic Ca2+ concentration in podocytes via B-2 kinin receptors

Background/Aim: Patients with idiopathic focal segmental glomerulosclerosis (FSGS) often develop a recurrence of the disease after kidney transplantation. In a number of FSGS patients, plasmapheresis and immunoadsorption procedures have been shown to transiently reduce proteinuria and are thought to do this by eliminating a circulating factor. Direct cellular effects of eluates from immunoadsorption procedures on podocytes, the primary target of injury in FSGS, have not yet been reported. Methods: Eluates were derived from antibody-based immunoadsorption of a patient suffering from primary FSGS, a patient with systemic lupus erythematosus, and a healthy volunteer. The cytosolic free Ca2+ concentration ({[}Ca2+](i)) of differentiated podocytes was measured by single-cell fura-2 microfluorescence measurements. Free and total immunoreactive kinin levels were measured by radioimmunoassay. Results: FSGS eluates increased the {[}Ca2+](i) levels concentration dependently (EC50 0.14 mg/ml; n = 3-19). 1 mg/ml eluate increased the {[}Ca2+](i) values reversibly from 82 +/- 12 to 1,462 +/- 370 nmol/l, and then they returned back to 100 16 nmol/l (n = 19). The eluate-induced increase of {[}Ca2+](i) consisted of an initial Ca2+ peak followed by a Ca2+ plateau which depended on the extracellular Ca2+ concentration. The eluate-induced increase of {[}Ca2+](i) was inhibited by the specific B-2 kinin receptor antagonist Hoe 140 in a concentration-dependent manner (IC50 2.47 nmol/l). In addition, prior repetitive application of bradykinin desensitized the effect of eluate on {[}Ca2+](i). A colonic epithelial cell line not reacting to bradykinin did not respond to eluate either (n = 6). Similar to FSGS eluates, the eluate preparations of both the systemic lupus patient and the healthy volunteer led to a biphasic, concentration-dependent {[}Ca2+](i) increase in poclocytes which again was inhibited by Hoe 140. Free kinins were detected in all eluate preparations. Conclusion: The procedure of antibody-based immunoadsorption leads to kinin in the eluate which elevates the {[}Ca2+](i) level of podocytes via B-2 kinin receptors. Copyright (C) 2002 S. Karger AG, Basel

Electronic and structural properties of alkali doped SWNT

Comprehensive experiments on structural and transport properties of alkali intercalated single walled carbon nanotubes (SWNT) are presented. The increasing electron density was measured as a shift of the Drude-edge in optical reflectivity in-situ with progressive doping. In saturation-doped samples the Drude-edge shifts into the visible (to 25,000 - 30,000 cm— 1 for potassium and rubidium doped samples) and the samples have a golden-brown color, similar to stage I graphite. X-ray diffraction reveals a crystalline rope structure with expanded lattice constant, similar to results of Duclaux et al. The change in the low temperature divergence of the resistivity after degassing at high temperature and high vacuum and after K-doping is studied in-situ

Dynamical role of anyonic excitation statistics in rapidly rotating Bose gases

We show that for rotating harmonically trapped Bose gases in a fractional quantum Hall state, the anyonic excitation statistics in the rotating gas can effectively play a {\em dynamical} role. For particular values of the two-dimensional coupling constant $g = -2\pi \hbar^2 (2k-1)/m$, where $k$ is a positive integer, the system becomes a noninteracting gas of anyons, with exactly obtainable solutions satisfying Bogomol'nyi self-dual order parameter equations. Attractive Bose gases under rapid rotation thus can be stabilized in the thermodynamic limit due to the anyonic statistics of their quasiparticle excitations.Comment: 4 pages of RevTex4; as published in Physical Review Letter

Dry and wet interfaces: Influence of solvent particles on molecular recognition

We present a coarse-grained lattice model to study the influence of water on the recognition process of two rigid proteins. The basic model is formulated in terms of the hydrophobic effect. We then investigate several modifications of our basic model showing that the selectivity of the recognition process can be enhanced by considering the explicit influence of single solvent particles. When the number of cavities at the interface of a protein-protein complex is fixed as an intrinsic geometric constraint, there typically exists a characteristic fraction that should be filled with water molecules such that the selectivity exhibits a maximum. In addition the optimum fraction depends on the hydrophobicity of the interface so that one has to distinguish between dry and wet interfaces.Comment: 11 pages, 7 figure

Growth and employment in Mexico: A quantitative analysis of policies

Mexico has sustained unusual rates of real income growth (6.4 % of average annual GDP growth between 19 50 and 1970) by following an economic policy giving first priority to manufacturing industries. Import substitution has been the dominating trade strategy since the late 1940s with only cautious steps to a more export oriented strategy since the mid-1960s. Mexico has not been spared the well known problems of regional and sectoral imbalances, a skewed personal income distribution and unemployment accompanying the industrialization of other developing countries. Beginning with the presidentship of Diaz Ordaz (1966-70) the attenuation of imbalances and inequities is proclaimed as a specific policy goal in plan documents, while employment creation is added to the list in the Echeverrîa administration. Although based on another stratum of the Mexican political economy the stepwise execution of a massive land reform has obvious complementary effects to the industrial policy. The agricultural sector absorbs much of the fast growing labor force which cannot be employed in the more capital-intensive industries under socially acceptable conditions. The land reform allows for a minimum wage and a working conditions policy in urban regions without increasing the urban unemployment to a level where it would disrupt the political system. Land reform and minimum wages help to keep political stability despite the social strains created by rapid industrialization as well as population growth