Polymer adsorption on heterogeneous surfaces

The adsorption of a single ideal polymer chain on energetically heterogeneous and rough surfaces is investigated using a variational procedure introduced by Garel and Orland (Phys. Rev. B 55 (1997), 226). The mean polymer size is calculated perpendicular and parallel to the surface and is compared to the Gaussian conformation and to the results for polymers at flat and energetically homogeneous surfaces. The disorder-induced enhancement of adsorption is confirmed and is shown to be much more significant for a heterogeneous interaction strength than for spatial roughness. This difference also applies to the localization transition, where the polymer size becomes independent of the chain length. The localization criterion can be quantified, depending on an effective interaction strength and the length of the polymer chain.Comment: accepted in EPJB (the Journal formerly known as Journal de Physique

Forces between Colloidal Particles in Aqueous Solutions Containing Monovalent and Multivalent Ions

The present article provides an overview of the recent progress in the direct force measurements between individual pairs of colloidal particles in aqueous salt solutions. Results obtained by two different techniques are being highlighted, namely with the atomic force microscope (AFM) and optical tweezers. One finds that the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) represents an accurate description of the force profiles even in the presence of multivalent ions, typically down to distances of few nanometers. However, the corresponding Hamaker constants and diffuse layer potentials must be extracted from the force profiles. At low salt concentrations, double layer forces remain repulsive and may become long ranged. At short distances, additional short range non-DLVO interactions may become important. Such an interaction is particularly relevant in the presence of multivalent counterions.Comment: Submitted on 30th of May 2016 as invited article to Curr. Opinion Colloid Interf. Sci. Edited by W. Ducker and P. Claesson. 15 Pages, 7 Figures 82 reference

Implementing US-style anti-fraud laws in the Australian pharmaceutical and health care industries

This article critically analyses the prospects for introducing United States anti-fraud (or anti-false claims) laws in the Australian health care setting. Australian governments spend billions of dollars each year on medicines and health care. A recent report estimates that the money lost to corporate fraud in Australia is growing at an annual rate of 7%, but that only a third of the losses are currently being detected. In the US, qui tam provisions - the component of anti-fraud or anti-false claims laws involving payments to whistleblowers - have been particularly successful in providing critical evidence allowing public prosecutors to recover damages for fraud and false claims made by corporations in relation to federal and state health care programs. The US continues to strengthen such anti-fraud measures and to successfully apply them to a widening range of areas involving large public investment. Australia still suffers from the absence of any comprehensive scheme that not only allows treble damages recovery for fraud on the public purse, but crucially supports such actions by providing financial encouragement for whistleblowing corporate insiders to expose evidence of fraud. Potential areas of application could include direct and indirect government expenditure on health care service provision, pharmaceuticals, medical devices, defence, carbon emissions compensation and tobacco-related illness. The creation in Australia of an equivalent to US anti-false claims legislation should be a policy priority, particularly in a period of financial stringency

The Bohm sheath criterion in strongly coupled complex plasmas

A modification of the classical Bohm sheath criterion is investigated in complex plasmas containing Boltzmann electrons, cold fluid ions and strongly coupled microparticles. Equilibrium is provided by an effective 'temperature' associated with electrostatic interactions between charged grains. Using the small-potential expansion approach of the Sagdeev potential, a significant reduction of the ion Bohm velocity is obtained for complex plasma parameters relevant for experiments. The result is of consequence for all problems involving ion drag on microparticles, including parametric instability, structure formation, wave propagation, etc

Robust Optimal Risk Sharing and Risk Premia in Expanding Pools

We consider the problem of optimal risk sharing in a pool of cooperative agents. We analyze the asymptotic behavior of the certainty equivalents and risk premia associated with the Pareto optimal risk sharing contract as the pool expands. We first study this problem under expected utility preferences with an objectively or subjectively given probabilistic model. Next, we develop a robust approach by explicitly taking uncertainty about the probabilistic model (ambiguity) into account. The resulting robust certainty equivalents and risk premia compound risk and ambiguity aversion. We provide explicit results on their limits and rates of convergence, induced by Pareto optimal risk sharing in expanding pools

Chromosomenzahlen von Farn- und Samenpflanzen aus Deutschland 2

Die in Kochia 1 (2006) begonnene Reihe wird im vorliegenden Dokument mit den Zählungen Nummer 22 bis 45 fortgesetzt