Introducing random walk measures to space syntax

We introduce Random Walk Closeness (RWC) to the space syntax computational paradigm. Random walks are stochastic processes in which an unbiased walker traverses a network purely based on his current location. Random walks have been used by space syntax in an agent based scenario, where results are simulation based. Here, the results are mathematical based, i.e. RWC is derived from access times, which are the average number of steps it takes to walk between locations. Results suggest an improvement in correlating pedestrian movement over Integration, RA and network Closeness

Virus Sharing, Genetic Sequencing, and Global Health Security

The WHO’s Pandemic Influenza Preparedness (PIP) Framework was a milestone global agreement designed to promote the international sharing of biological samples to develop vaccines, while that ensuring poorer countries would have access to those vaccines. Since the PIP Framework was negotiated, scientists have developed the capacity to use genetic sequencing data (GSD) to develop synthetic viruses rapidly for product development of life-saving technologies in a time-sensitive global emergency—threatening to unravel the Framework. Access to GSD may also have major implications for biosecurity, biosafety, and intellectual property (IP). By rendering the physical transfer of viruses antiquated, GSD may also undermine the effectiveness of the PIP Framework itself, with disproportionate impacts on poorer countries. We examine the changes that need to be made to the PIP Framework to address the growing likelihood that GSD might be shared instead of physical virus samples. We also propose that the international community harness this opportunity to expand the scope of the PIP Framework beyond only influenza viruses with pandemic potential. In light of non-influenza pandemic threats such as the Middle East Respiratory Syndrome (MERS) and Ebola, we call for an international agreement on the sharing of the benefits of research – such as vaccines and treatments – for other infectious diseases to ensure not only a more secure and healthy world, but also a more just world, for humanity

A Public Health Emergency of International Concern? Response to a Proposal to Apply the International Health Regulations to Antimicrobial Resistance

Adam Kamradt-Scott critiques a proposal to apply the International Health Regulations (IHR) to the global health threat of antimicrobial resistance

A handheld diagnostic system for 6LoWPAN networks

The successful deployment of low-power wireless sensor networks (WSNs) in real application environments is a much broader exercise than just the simple instrumentation of the intended monitoring site. Many problems, from node malfunctions to connectivity issues, may arise during commissioning of these networks. These need to be corrected on the spot, often within limited time, to avoid undesired delays in commissioning and yet a fully functional system does not guarantee that no new problems will occur after leaving the site. In this paper we present the first ever (to our knowledge) implementation of a handheld diagnostic system for fast on-site commissioning of low-power IPv6 (6LoWPAN) WSNs as well as troubleshooting of network problems during and after deployment. This system can be used where traditional solutions are insufficient to ascertain the root causes of any problems encountered at no additional complexity in the implementation of the WSN. The embedded diagnosis capability in our system is based on a lightweight decision tree that distills the functioning of communication protocols in use by the network, with a major focus on interoperable IPv6 standards and protocols for low-power WSNs. To show the applicability of our system, we present a set of experiments based on results from a real deployment in a large construction site. Through these experiments, important performance insights are gained that can be used as guidelines for improvement of operation and maintenance of 6LoWPAN networks.This research has been funded by the EPSRC Innovation and Knowledge Centre for Smart Infrastructure and Construction project (EP/K000314/1). The authors wish to thank Costain-Skanska Joint Venture (CSJV) and our industrial partner Crossrail for allowing access and instrumentation of the Paddington site referenced in this paper

Magnetic properties of (Fe1−x_{1-x}Cox_x)2_2B alloys and the effect of doping by 5dd elements

We have explored, computationally and experimentally, the magnetic properties of \fecob{} alloys. Calculations provide a good agreement with experiment in terms of the saturation magnetization and the magnetocrystalline anisotropy energy with some difficulty in describing Co$_2$B, for which it is found that both full potential effects and electron correlations treated within dynamical mean field theory are of importance for a correct description. The material exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations between $x=0.1$ and $x=0.5$. A simple model for the temperature dependence of magnetic anisotropy suggests that the complicated non-monotonous temperature behaviour is mainly due to variations in the band structure as the exchange splitting is reduced by temperature. Using density functional theory based calculations we have explored the effect of substitutional doping the transition metal sublattice by the whole range of 5$d$ transition metals and found that doping by Re or W elements should significantly enhance the magnetocrystalline anisotropy energy. Experimentally, W doping did not succeed in enhancing the magnetic anisotropy due to formation of other phases. On the other hand, doping by Ir and Re was successful and resulted in magnetic anisotropies that are in agreement with theoretical predictions. In particular, doping by 2.5~at.\% of Re on the Fe/Co site shows a magnetocrystalline anisotropy energy which is increased by 50\% compared to its parent (Fe$_{0.7}$Co$_{0.3}$)$_2$B compound, making this system interesting, for example, in the context of permanent magnet replacement materials or in other areas where a large magnetic anisotropy is of importance.Comment: 15 pages 17 figure

HIV cure research in the time of COVID-19 - Antiretroviral therapy treatment interruption trials: A discussion paper

This discussion paper addresses the safety of HIV cure studies, particularly those involving stopping antiretroviral therapy, known as an analytic treatment interruption (ATI) in the context of the SARS-CoV-2 pandemic. More than 30 studies listed on ClinicalTrials.gov include an ATI and many others were planned to begin over the next 12 months but most were halted due to the COVID-19 pandemic. We consider the ethics, risks and practical considerations to be taken into account before re-opening HIV cure clinical trials, noting the specific risks of ATI in the context of circulating SARS-CoV-2

Virological failure and development of new resistance mutations according to CD4 count at combination antiretroviral therapy initiation

No randomized controlled trials have yet reported an individual patient benefit of initiating combination antiretroviral therapy (cART) at CD4 counts > 350 cells/μL. It is hypothesized that earlier initiation of cART in asymptomatic and otherwise healthy individuals may lead to poorer adherence and subsequently higher rates of resistance development