Approximate disease dynamics in household-structured populations.

We argue that the large-dimensional dynamical systems which frequently occur in biological models can sometimes be effectively reduced to much smaller ones. We illustrate this by applying projection operator techniques to a mean-field model of an infectious disease spreading through a population of households. In this way, we are able to accurately approximate the dynamics of the system in terms of a few key quantities greatly reducing the number of equations required. We investigate linear stability in this framework and find a new way of calculating the familiar threshold criterion for household systems

trans-Bis(tert-butylamine)dichloropalladium(II)

The asymmetric unit of the title complex, trans-[PdCl2(NH2tBu)2], consists of two independent square-planar molecules, linked together in a hydrogen-bonding network, with the resultant alignment of the tert-butyl groups defining a two-dimensional layered structure approximately parallel to (001)

Magnetic coupling constants from a hybrid density functional with 35% Hartree-Fock exchange

Published versio

The epidemiology of sexually transmitted infections in the United Kingdom: impact of behaviour, services and interventions

Sexually transmitted infections (STIs) are a major public health concern. The United Kingdom (UK) has some of the most advanced STI surveillance systems globally. This review uses national surveillance data to describe remarkable changes in STI epidemiology in the UK over the last century and explores behavioural and demographic shifts that may explain these trends. The past ten years have seen considerable improvements in STI service provision and the introduction of national public health interventions. However, sexual health inequalities persist and men who have sex with men, young adults and black ethnic minorities remain a priority for interventions. Technological advances in testing and a shift in sexual health service commissioning arrangements will present both opportunities and challenges in future

Transmission parameters of the 2001 foot and mouth epidemic in Great Britain.

Despite intensive ongoing research, key aspects of the spatial-temporal evolution of the 2001 foot and mouth disease (FMD) epidemic in Great Britain (GB) remain unexplained. Here we develop a Markov Chain Monte Carlo (MCMC) method for estimating epidemiological parameters of the 2001 outbreak for a range of simple transmission models. We make the simplifying assumption that infectious farms were completely observed in 2001, equivalent to assuming that farms that were proactively culled but not diagnosed with FMD were not infectious, even if some were infected. We estimate how transmission parameters varied through time, highlighting the impact of the control measures on the progression of the epidemic. We demonstrate statistically significant evidence for assortative contact patterns between animals of the same species. Predictive risk maps of the transmission potential in different geographic areas of GB are presented for the fitted models

Bulk spectral function sum rule in QCD-like theories with a holographic dual

We derive the sum rule for the spectral function of the stress-energy tensor in the bulk (uniform dilatation) channel in a general class of strongly coupled field theories. This class includes theories holographically dual to a theory of gravity coupled to a single scalar field, representing the operator of the scale anomaly. In the limit when the operator becomes marginal, the sum rule coincides with that in QCD. Using the holographic model, we verify explicitly the cancellation between large and small frequency contributions to the spectral integral required to satisfy the sum rule in such QCD-like theories.Comment: 16 pages, 2 figure

Combining intracellular selection with protein-fragment complementation to derive A interacting peptides

Aggregation of the β-amyloid (Aβ) peptide into toxic oligomers is considered the primary event in the pathogenesis of Alzheimer's disease. Previously generated peptides and mimetics designed to bind to amyloid fibrils have encountered problems in solubility, protease susceptibility and the population of small soluble toxic oligomers oligomers. We present a new method that opens the possibility of deriving new amyloid inhibitors. The intracellular protein-fragment complementation assay (PCA) approach uses a semi-rational design approach to generate peptides capable of binding to Aβ. Peptide libraries are based on Aβ regions responsible for instigating amyloidosis, with screening and selection occurring entirely inside Escherichia coli. Successfully selected peptides must therefore bind Aβ and recombine an essential enzyme while permitting bacterial cell survival. No assumptions are made regarding the mechanism of action for selected binders. Biophysical characterisation demonstrates that binding induces a noticeable reduction in amyloid. Therefore, this amyloid-PCA approach may offer a new pathway for the design of effective inhibitors against the formation of amyloid in general