Information-theoretic measurements of coupling between structure and dynamics in glass-formers

We analyse the connections between structure and dynamics in two model glass-formers, using the mutual information between an initial configuration and the ensuing dynamics to compare the predictive value of different structural observables. We consider the predictive power of normal modes, locally favoured structures, and coarse-grained measurements of local energy and density. The mutual information allows the influence of the liquid structure on the dynamics to be analysed quantitatively as a function of time, showing that normal modes give the most useful predictions on short time scales while local energy and density are most strongly predictive at long times.Comment: 10 pages, 7 fig

Strong geometric frustration in model glassformers

We consider three popular model glassformers, the Kob-Andersen and Wahnstr\"om binary Lennard-Jones models and weakly polydisperse hard spheres. Although these systems exhibit a range of fragilities, all feature a rather similar behaviour in their local structure approaching dynamic arrest. In particular we use the dynamic topological cluster classification to extract a locally favoured structure which is particular to each system. These structures form percolating networks, however in all cases there is a strong decoupling between structural and dynamic lengthscales. We suggest that the lack of growth of the structural lengthscale may be related to strong geometric frustration.Comment: 14 pages, Accepted by J. Non-Crystalline Solids, 7th International Discussion Meeting on Relaxation in Complex Systems Proceeding

Using mutual information to measure order in model glass-formers

Whether or not there is growing static order accompanying the dynamical heterogeneity and increasing relaxation times seen in glassy systems is a matter of dispute. An obstacle to resolving this issue is that the order is expected to be amorphous and so not amenable to simple order parameters. We use mutual information to provide a general measurement of order that is sensitive to multi-particle correlations. We apply this to two glass-forming systems (2D binary mixtures of hard disks with different size ratios to give varying amounts of hexatic order) and show that there is little growth of amorphous order in the system without crystalline order. In both cases we measure the dynamical length with a four-point correlation function and find that it increases significantly faster than the static lengths in the system as density is increased. We further show that we can recover the known scaling of the dynamic correlation length in a kinetically constrained model, the 2-TLG.Comment: 10 pages, 12 Figure

Mutual information reveals multiple structural relaxation mechanisms in a model glass former

Among the key challenges to our understanding of solidification in the glass transition is that it is accompanied by little apparent change in structure. Recently, geometric motifs have been identified in glassy liquids, but a causal link between these motifs and solidification remains elusive. One ‘smoking gun’ for such a link would be identical scaling of structural and dynamic lengthscales on approaching the glass transition, but this is highly controversial. Here we introduce an information theoretic approach to determine correlations in displacement for particle relaxation encoded in the initial configuration of a glass-forming liquid. We uncover two populations of particles, one inclined to relax quickly, the other slowly. Each population is correlated with local density and geometric motifs. Our analysis further reveals a dynamic lengthscale similar to that associated with structural properties, which may resolve the discrepancy between structural and dynamic lengthscales

A pragmatic harm reduction approach to manage a large outbreak of wound botulism in people who inject drugs, Scotland 2015

Abstract Background People who inject drugs (PWID) are at an increased risk of wound botulism, a potentially fatal acute paralytic illness. During the first 6 months of 2015, a large outbreak of wound botulism was confirmed among PWID in Scotland, which resulted in the largest outbreak in Europe to date. Methods A multidisciplinary Incident Management Team (IMT) was convened to conduct an outbreak investigation, which consisted of enhanced surveillance of cases in order to characterise risk factors and identify potential sources of infection. Results Between the 24th of December 2014 and the 30th of May 2015, a total of 40 cases were reported across six regions in Scotland. The majority of the cases were male, over 30 and residents in Glasgow. All epidemiological evidence suggested a contaminated batch of heroin or cutting agent as the source of the outbreak. There are significant challenges associated with managing an outbreak among PWID, given their vulnerability and complex addiction needs. Thus, a pragmatic harm reduction approach was adopted which focused on reducing the risk of infection for those who continued to inject and limited consequences for those who got infected. Conclusions The management of this outbreak highlighted the importance and need for pragmatic harm reduction interventions which support the addiction needs of PWID during an outbreak of spore-forming bacteria. Given the scale of this outbreak, the experimental learning gained during this and similar outbreaks involving spore-forming bacteria in the UK was collated into national guidance to improve the management and investigation of future outbreaks among PWID

The difference that tenure makes

This paper argues that housing tenures cannot be reduced to either production relations or consumption relations. Instead, they need to be understood as modes of housing distribution, and as having complex and dynamic relations with social classes. Building on a critique of both the productionist and the consumptionist literature, as well as of formalist accounts of the relations between tenure and class, the paper attempts to lay the foundations for a new theory of housing tenure. In order to do this, a new theory of class is articulated, which is then used to throw new light on the nature of class-tenure relations

Advance care planning, a multi-centre cluster randomised clinical trial: the research protocol of the ACTION study

Background: Awareness of preferences regarding medical care should be a central component of the care of patients with advanced cancer. Open communication can facilitate this but can occur in an ad hoc or variable manner. Advance care planning (ACP) is a formalized process of communication between patients, relatives and professional caregivers about patients’ values and care preferences. It raises awareness of the need to anticipate possible future deterioration of health. ACP has the potential to improve current and future healthcare decision making, provide patients with a sense of control, and improve their quality of life. Methods/Design: We will study the effects of the ACP program Respecting Choices on the quality of life of patients with advanced lung or colorectal cancer. In a phase III multicenter cluster randomised controlled trial, 22 hospitals in 6 countries will be randomised. In the intervention sites, patients will be offered interviews with a trained facilitator. In the control sites, patients will receive care as usual. In total, 1360 patients will be included. All participating patients will be asked to complete questionnaires at inclusion, and again after 2.5 and 4.5 months. If a patient dies within a year after inclusion, a relative will be asked to complete a questionnaire on end-of-life care. Use of medical care will be assessed by checking medical files. The primary endpoint is patients’ quality of life at 2.5 months ost-inclusion. Secondary endpoints are the extent to which care as received is aligned with patients’ preferences, patients’ evaluation of decision-making processes, quality of end-of-life care and cost-effectiveness of the intervention. A complementary qualitative study will be carried out to explore the lived experience of engagement with the Respecting Choices program from the perspectives of patients, their Personal Representatives, healthcare providers and facilitators. Discussion: Transferring the concept of ACP from care of the elderly to patients with advanced cancer, who on average are younger and retain their mental capacity for a larger part of their disease trajectory, is an important next step in an era of increased focus on patient centered healthcare and shared decision-making. Trial registration: International Standard Randomised Controlled Trial Number: ISRCTN63110516. Date of registration: 10/3/2014. Keywords: Advance care planning, Oncology, Quality of life, Medical decision-makin

Sequence-defined multifunctional polyethers via liquid-phase synthesis with molecular sieving

Synthetic chemists have devoted tremendous effort towards the production of precision synthetic polymers with defined sequences and specific functions. However, the creation of a general technology that enables precise control over monomer sequence, with efficient isolation of the target polymers, is highly challenging. Here, we report a robust strategy for the production of sequence-defined synthetic polymers through a combination of liquid-phase synthesis and selective molecular sieving. The polymer is assembled in solution with real-time monitoring to ensure couplings proceed to completion, on a three-armed star-shaped macromolecule to maximize efficiency during the molecular sieving process. This approach is applied to the construction of sequence-defined polyethers, with side-arms at precisely defined locations that can undergo site-selective modification after polymerization. Using this versatile strategy, we have introduced structural and functional diversity into sequence-defined polyethers, unlocking their potential for real-life applications in nanotechnology, healthcare and information storage

Widening participation in higher education: the role of professional and social class identities and commitments

Since the neoliberal reforms to British education in the 1980s, education debates have been saturated with claims to the efficacy of the market as a mechanism for improving the content and delivery of state education. In recent decades with the expansion and ‘massification’ of higher education, widening participation (WP) has acquired an increasingly important role in redressing the under-representation of certain social groups in universities. Taken together, these trends neatly capture the twin goals of New Labour’s programme for education reform: economic competitiveness and social justice. But how do WP professionals negotiate competing demands of social equity and economic incentive? In this paper we explore how the hegemony of neoliberal discourse – of which the student as consumer is possibly the most pervasive – can be usefully disentangled from socially progressive, professional discourses exemplified through the speech and actions of WP practitioners and managers working in British higher education institutions

A two-step mechanism for epigenetic specification of centromere identity and function

The basic determinant of chromosome inheritance, the centromere, is specified in many eukaryotes by an epigenetic mark. Using gene targeting in human cells and fission yeast, chromatin containing the centromere-specific histone H3 variant CENP-A is demonstrated to be the epigenetic mark that acts through a two-step mechanism to identify, maintain and propagate centromere function indefinitely. Initially, centromere position is replicated and maintained by chromatin assembled with the centromere-targeting domain (CATD) of CENP-A substituted into H3. Subsequently, nucleation of kinetochore assembly onto CATD-containing chromatin is shown to require either the amino- or carboxy-terminal tail of CENP-A for recruitment of inner kinetochore proteins, including stabilizing CENP-B binding to human centromeres or direct recruitment of CENP-C, respectively.National Institutes of Health grant: (GM 074150); Ludwig Institute for Cancer Research; European Molecular Biology Organization (EMBO) long-term fellowship