Small-World Rouse Networks as models of cross-linked polymers

We use the recently introduced small-world networks (SWN) to model cross-linked polymers, as an extension of the linear Rouse-chain. We study the SWN-dynamics under the influence of external forces. Our focus is on the structurally and thermally averaged SWN stretching, which we determine both numerically and analytically using a psudo-gap ansatz for the SWN-density of states. The SWN stretching is related to the probability of a random-walker to return to its origin on the SWN. We compare our results to the corresponding ones for Cayley trees.Comment: 14 pages, 4 figures. Preprint version, submitted to JC

Final project report: EEC 2092/91 (ORGANIC) Revision

This report summarises the findings of the project that have been presented in a number of separate reports and publications. In the Chapters 2 to 5 the approach, results and conclusions of the project are summarised, following the structure of the different work packages. Chapter 2 summarises the work on ethical values of organic agriculture. Chapter 3 looks at the differences in the implementation of Regulation (EEC) 2092/91 across Europe and compares the European Regulation with international standards. Chapters 4 and 5 summarise the findings that relate to reducing the dependency on non-organic inputs in the case of feed and seed. The final Chapter 6 consolidates the recommendations of the whole project arising from the various different work packages in one place. Recommendations are aimed in particular at the second stage of the ongoing revision process of the European Regulation, the transfer of the detailed rules from the Annexes of the Regulation (EEC) 2092/91 that is expected to start after the completion of the project. Further recommendations for standard setting bodies, regulators and research recommendations are also presented. The overall objective of the project was to provide recommendations for the revision and further development of the Regulation (EEC) 2092/91 and other standards for organic agriculture, broken down into a number of specific objectives that resulted in 12 seperate reports. The basic ethical values and value differences of organic agriculture in Europe was identified through stakeholder consultation (D 2.1) and through literature as part of developing a procedure for balancing and integrating the basic values in developments of EU regulation (D 2.3). Organic standards from national and private organisations in Europe were compared with the EU regulation with help of database (www.organicrules.org) and differences were analysed to give recommendations on further harmonisation of the EU regulation (D 3.2). The knowledge on how to achieve 100 % organic rations in diets for livestock was expanded through a meta-analysis of literature and an overview of the current situation to characterise the availability of protein sources for 100% organic diets for pigs and poultry was produced (D 4.1 part 1 and 2). Criteria for use of organic inputs, evaluation criteria for Annex II C: Feed materials and Annex II D: Dietary supplements of Regulation (EEC) 2092/91 were developed (D. 4.2). A guide for operators was developed (D 4.3). The knowledge on how to reduce the use of non-organic seed and vegetative propagation materials was improved through reports on seed borne diseases in organic seed and propagation material (D 5.1), on the importance of quality characterising in organic seed and propagation material (D 5.2) and analysis of national derogation regimes (D 5.3). The project produced 12 reports, 7 scientific publications in peer-reviewed journals, and a project web-page at www.organic-revision.org where all reports and further documents are available. It organised 3 workshops with stakeholders and had ongoing communication with the Unit on Organic Farming in DG Agriculture responsible for the Organic Regulation. Members of the team produced in total more than 250 dissemination items

Antidepressant induced sexual dysfunction part 2: assessment and management

Sexual dysfunction is a common side effect of treatment with antidepressants, particularly those with a predominantly serotonergic mechanism of action. Although there has been an increasing awareness of the problem in recent years, it is still probably true to say that sexual side effects often go undetected. Antidepressant induced sexual dysfunction has significant implications for a patient's quality of life and that of their family unit. The issue cannot be ignored because it is likely to impact on a patient's sense of wellbeing, their compliance with medication and ultimately the prognosis of their illness. This review is presented in two parts. The first part focused on the prevalence of antidepressant induced sexual dysfunction and its clinical presentation both generally and in the case of individual classes of antidepressants. This second part focuses on the assessment and management of the problem. The aim of this review is to improve overall awareness of sexual side effects and to suggest a rational approach to their assessment and management. It is not intended to be a detailed exploration of underlying causative mechanisms and receptor neurochemistry. Keywords: antidepressants, sexual dysfunction South African Psychiatry Review Vol. 9(2) 2006: 79-8

Antidepressant induced sexual dysfunction, part 1: epidemiology and clinical presentation

Sexual dysfunction is a common side effect of treatment with antidepressants, particularly those with a predominantly serotonergic mechanism of action. Although there has been an increasing awareness of the problem in recent years, it is still probably true to say that sexual side effects often go undetected. Antidepressant induced sexual dysfunction has significant implications for a patient's quality of life and that of their family unit. The issue cannot be ignored because it is likely to impact on a patient's sense of wellbeing, their compliance with medication and ultimately the prognosis of their illness. This review will be presented in two parts. The first part focuses on the prevalence of antidepressant induced sexual dysfunction and its clinical presentation both generally and in the case of individual classes of antidepressants. The second part will focus on the assessment and management of the problem. The aim of this review is to improve overall awareness of sexual side effects and to suggest a rational approach to their detection and management. It is not intended to be a detailed exploration of underlying causative mechanisms and receptor neurochemistry. Keywords: antidepressants, sexual dysfunction, serotonergic South African Psychiatry Review Vol. 9(1) 2006: 24-2

Organic Rules and Certification

Development of the database, www.organicrules.org: The database was developed by ICROFS (DARCOF) and FiBL in 2005 - 2006 for comparison of European and international standards with the EU Regulation 2092/91 in the EU FP6 project, ”EEC 2092/91 Revision” (www.organic-revision). In the EU FP7 project, Economic Analysis of Certification Systems in Organic Food and Farming, www.CERTCOST.org (2008-2011). The database has been further developed by ICROFS. The information for the database is collected by the 9 partners of the CERTCOST project, and it is edited by Lizzie Melby Jespersen, ICROFS

Persistence of Randomly Coupled Fluctuating Interfaces

We study the persistence properties in a simple model of two coupled interfaces characterized by heights h_1 and h_2 respectively, each growing over a d-dimensional substrate. The first interface evolves independently of the second and can correspond to any generic growing interface, e.g., of the Edwards-Wilkinson or of the Kardar-Parisi-Zhang variety. The evolution of h_2, however, is coupled to h_1 via a quenched random velocity field. In the limit d\to 0, our model reduces to the Matheron-de Marsily model in two dimensions. For d=1, our model describes a Rouse polymer chain in two dimensions advected by a transverse velocity field. We show analytically that after a long waiting time t_0\to \infty, the stochastic process h_2, at a fixed point in space but as a function of time, becomes a fractional Brownian motion with a Hurst exponent, H_2=1-\beta_1/2, where \beta_1 is the growth exponent characterizing the first interface. The associated persistence exponent is shown to be \theta_s^2=1-H_2=\beta_1/2. These analytical results are verified by numerical simulations.Comment: 15 pages, 3 .eps figures include

Coupling of shells in a carbon nanotube quantum dot

We systematically study the coupling of longitudinal modes (shells) in a carbon nanotube quantum dot. Inelastic cotunneling spectroscopy is used to probe the excitation spectrum in parallel, perpendicular and rotating magnetic fields. The data is compared to a theoretical model including coupling between shells, induced by atomically sharp disorder in the nanotube. The calculated excitation spectra show good correspondence with experimental data.Comment: 8 pages, 4 figure

Tunneling Spectroscopy of Quasiparticle Bound States in a Spinful Josephson Junction

The spectrum of a segment of InAs nanowire, confined between two superconducting leads, was measured as function of gate voltage and superconducting phase difference using a third normal-metal tunnel probe. Sub-gap resonances for odd electron occupancy---interpreted as bound states involving a confined electron and a quasiparticle from the superconducting leads, reminiscent of Yu-Shiba-Rusinov states---evolve into Kondo-related resonances at higher magnetic fields. An additional zero bias peak of unknown origin is observed to coexist with the quasiparticle bound states.Comment: Supplementary information available here: https://dl.dropbox.com/u/1742676/Chang_Sup.pd

Nonequilibrium Cotunneling through a Three-Level Quantum Dot

We calculate the nonlinear cotunneling conductance through a quantum dot with 3 electrons occupying the three highest lying energy levels. Starting from a 3-orbital Anderson model, we apply a generalized Schrieffer-Wolff transformation to derive an effective Kondo model for the system. Within this model we calculate the nonequilibrium occupation numbers and the corresponding cotunneling current to leading order in the exchange couplings. We identify the inelastic cotunneling thresholds and their splittings with applied magnetic field, and make a qualitative comparison to recent experimental data on carbon nanotube and InAs quantum-wire quantum dots. Further predictions of the model like cascade resonances and a magnetic-field dependence of the orbital level splitting are not yet observed but within reach of recent experimental work on carbon nanotube and InAs nanowire quantum dots.Comment: 12 pages, 13 figure

Small-World Networks: Links with long-tailed distributions

Small-world networks (SWN), obtained by randomly adding to a regular structure additional links (AL), are of current interest. In this article we explore (based on physical models) a new variant of SWN, in which the probability of realizing an AL depends on the chemical distance between the connected sites. We assume a power-law probability distribution and study random walkers on the network, focussing especially on their probability of being at the origin. We connect the results to L\'evy Flights, which follow from a mean field variant of our model.Comment: 11 pages, 4 figures, to appear in Phys.Rev.