Mechanism of membrane tube formation induced by adhesive nanocomponents

We report numerical simulations of membrane tubulation driven by large colloidal particles. Using Monte Carlo simulations we study how the process depends on particle size, concentration and binding strength, and present accurate free energy calculations to sort out how tube formation compares with the competing budding process. We find that tube formation is a result of the collective behavior of the particles adhering on the surface, and it occurs for binding strengths that are smaller than those required for budding. We also find that long linear aggregates of particles forming on the membrane surface act as nucleation seeds for tubulation by lowering the free energy barrier associated to the process

Absorbing processes in Richardson diffusion: analytical results

We consider the recently addressed problem of a passive particle (a predator), being the center of a ``sphere of interception'' of radius $R$ and able to absorb other passive particles (the preys) entering into the sphere. Assuming that all the particles are advected by a turbulent flow and that, in particular, the Richardson equation properly describes the relative dispersion, we calculate an analytical expression for the flux into the sphere as a function of time, assuming an initial constant density of preys outside the sphere. In the same framework, we show that the distribution of times of first passage into the sphere has a $t^{-5/2}$ power law tail, seen in contrast to the $t^{-3/2}$ appearing in standard 3D diffusion. We also discuss the correction due to the integral length scale on the results in the stationary case.Comment: 6 pages, 3 figures, sunbmitted to Physics of Fluid

Labeling Policies in Food Markets: Private Incentives, Public Intervention, and Welfare Effects

This study considers the welfare impact of labeling policies of agricultural commodities with specific characteristics. Using a model of vertical differentiation, the effects on equilibrium and welfare levels are calculated. The introduction of the regulation and the emergence of two differentiated competitive markets leaves consumers and high-quality producers better off, while low-quality producers are worse off. With high costs and low quality differences, the total welfare impact of the regulation can be negative. Findings show that when high-quality producers can exercise market power, the regulation could be more easily accepted by producers, but it would have a negative effect on consumers.asymmetric information, food markets, labeling, market power, vertical differentiation, welfare effects, Agricultural and Food Policy,

Exploiting classical nucleation theory for reverse self-assembly

In this paper we introduce a new method to design interparticle interactions to target arbitrary crystal structures via the process of self-assembly. We show that it is possible to exploit the curvature of the crystal nucleation free-energy barrier to sample and select optimal interparticle interactions for self-assembly into a desired structure. We apply this method to find interactions to target two simple crystal structures: a crystal with simple cubic symmetry and a two-dimensional plane with square symmetry embedded in a three-dimensional space. Finally, we discuss the potential and limits of our method and propose a general model by which a functionally infinite number of different interaction geometries may be constructed and to which our reverse self-assembly method could in principle be applied.Comment: 7 pages, 6 figures. Published in the Journal of Chemical Physic

Tensor network representations from the geometry of entangled states

Tensor network states provide successful descriptions of strongly correlated quantum systems with applications ranging from condensed matter physics to cosmology. Any family of tensor network states possesses an underlying entanglement structure given by a graph of maximally entangled states along the edges that identify the indices of the tensors to be contracted. Recently, more general tensor networks have been considered, where the maximally entangled states on edges are replaced by multipartite entangled states on plaquettes. Both the structure of the underlying graph and the dimensionality of the entangled states influence the computational cost of contracting these networks. Using the geometrical properties of entangled states, we provide a method to construct tensor network representations with smaller effective bond dimension. We illustrate our method with the resonating valence bond state on the kagome lattice.Comment: 35 pages, 9 figure

The French Legal System

This article is a book review of C Dadomo and S Farran The French Legal System (Sweet and Maxwell, London, 1993). The book aims to familiarise the reader with sources of French law, the structure of the courts and professions, and the characteristics of the legal process, while indicating some of the main differences between the English legal system and the French. Angelo states that the book provides a clear presentation of background data necessary to properly understand the above topics. The article concludes that the book is a useful resource that serves the needs of both the novice and the professional.&nbsp

Japan: Economic Success and Legal System

This article is a book review of Harald Baum (ed) Japan: Economic Success and Legal System (de Gruyter, Berlin, 1997) pp i-xxii, 1-401. This book is the record of the 1995 conference on "Japan: Economic Success and Legal System" which was held at the Japanese-German Center, Berlin, Germany. The book is divided into four main parts: dispute resolution, contract in Japanese business, Japanese enterprise, and the bureaucracy in Japanese economic and legal affairs. Angelo praises the book as one that gives cause for reflection on matters of Japanese law and comparative, as well as the human condition generally.&nbsp

Hepatitis B immunisation : a survey of surgeons and theatre nurses

Acute viral hepatitis remains a serious condition. Its long-term sequelae include cirrhosis and hepatocellular carcinoma. Health workers constitute a high-risk group for contracting hepatitis B. A group of clinicians associated with invasive procedures and nurses working in operating theatres were invited to answer a confidential questionnaire concerning hepatitis B immunisation and the use of protective measures. A self-administered confidential questionnaire was sent to 152 clinicians and 97 theatre nurses, of whom 82 and 74 respectively responded, giving an overall response rate of 63 %. Whilst 91% of respondents considered their speciality as being of high risk for hepatitis B only 63% of them were fully immunised and of these only 51% had had their immunity tested. Out of those who checked their antibody status 19% did so following a needle stick injury. 60% of our respondents had had a needle stick injury over the past year. Even so barrier precaution techniques were used infrequently with only 17% always or at least frequently using double gloving and 10% wearing a visor during operations. Some respondents also commented on the poor availability of resources such as impermeable gowns or blunt needles which are established precautions against contamination from hepatitis B.peer-reviewe