Emma Terama

Influence of Ethanol on Lipid Membranes: From Lateral Pressure Profiles to Dynamics and Partitioning.

We have combined experiments with atomic-scale molecular dynamics simulations to consider the influence of ethanol on a variety of lipid membrane properties. We first employed isothermal titration calorimetry together with the solvent-null method to study the partitioning of ethanol molecules into saturated and unsaturated membrane systems. The results show that ethanol partitioning is considerably more favorable in unsaturated bilayers, which are characterized by their more disordered nature compared to their saturated counterparts. Simulation studies at varying ethanol concentrations propose that the partitioning of ethanol depends on its concentration, implying that the partitioning is a nonideal process. To gain further insight into the permeation of alcohols and their influence on lipid dynamics, we also employed molecular dynamics simulations to quantify kinetic events associated with the permeation of alcohols across a membrane, and to characterize the rotational and lateral diffusion of lipids and alcohols in these systems. The simulation results are in agreement with available experimental data and further show that alcohols have a small but non-vanishing effect on the dynamics of lipids in a membrane. The influence of ethanol on the lateral pressure profile of a lipid bilayer is found to be prominent: ethanol reduces the tension at the membrane-water interface and reduces the peaks in the lateral pressure profile close to the membrane-water interface. The changes in the lateral pressure profile are several hundred atmospheres. This supports the hypothesis that anesthetics may act by changing the lateral pressure profile exerted on proteins embedded in membranes.

Dielectrophoresis of nanocolloids: A molecular dynamics study

Abstract.Dielectrophoresis (DEP), the motion of polarizable particles in non-uniform electric fields, has become an important tool for the transport, separation, and characterization of microparticles in biomedical and nanoelectronics research. In this article we present, to our knowledge, the first molecular dynamics simulations of DEP of nanometer-sized colloidal particles. We introduce a simplified model for a polarizable nanoparticle, consisting of a large charged macroion and oppositely charged microions, in an explicit solvent. The model is then used to study DEP motion of the particle at different combinations of temperature and electric field strength. In accord with linear response theory, the particle drift velocities are shown to be proportional to the DEP force. Analysis of the colloid DEP mobility shows a clear time dependence, demonstrating the variation of friction under non-equilibrium. The time dependence of the mobility further results in an apparent weak variation of the DEP displacements with temperature.

Characterising vulnerability of the elderly to climate change in the Nordic region

Elderly people are known to be more vulnerable than the general population to a range of weather-related hazards such as heat waves, icy conditions and cold periods. In the Nordic region, some of these hazards are projected to change their frequency and intensity in the future, while at the same time strong increases are projected in the proportion of elderly in the population. This paper reports results from three projects studying the potential impacts of climate change on elderly people in the Nordic region. An interactive web-based tool has been developed for mapping and combining indicators of climate change vulnerability of the elderly, by municipality, across three Nordic countries: Finland, Norway and Sweden. The tool can also be used for projecting temperature-related mortality in Finland under different projections of future climate. The approach to vulnerability mapping differs from most previous studies in which researchers selected the indicators to combine into an index. Here, while researchers compile data on indicators that can be accessed in the mapping tool, the onus is on the users of the tool to decide which indicators are of interest and whether to map them individually or as combined indices. Stakeholders with responsibility for the care and welfare of the elderly were engaged in the study through interviews and a workshop. They affirmed the usefulness of the prototype mapping tool for raising awareness about climate change as a potential risk factor for the elderly and offered suggestions on potential refinements, which have now been implemented. These included adding background information on possible adaptation measures for ameliorating the impacts of extreme temperatures, and improved representation of uncertainties in projections of future exposure and adaptive capacity.

Enhanced dielectrophoresis of nanocolloids by dimer formation

We investigate the dielectrophoretic motion of charge-neutral, polarizable nanocolloids through molecular dynamics simulations. Comparison to analytical results derived for continuum systems shows that the discrete charge distributions on the nanocolloids have a significant impact on their coupling to the external field. Aggregation of nanocolloids leads to enhanced dielectrophoretic transport, provided that increase in the dipole moment upon aggregation can overcome the related increase in friction. The dimer orientation and the exact structure of the nanocolloid charge distribution are shown to be important in the enhanced transport.

Beyond Academia – Interrogating Research Impact in the Research Excellence Framework

Big changes to the way in which research funding is allocated to UK universities were brought about in the Research Excellence Framework (REF), overseen by the Higher Education Funding Council, England. Replacing the earlier Research Assessment Exercise, the purpose of the REF was to assess the quality and reach of research in UK universities–and allocate funding accordingly. For the first time, this included an assessment of research ‘impact’, accounting for 20% of the funding allocation. In this article we use a text mining technique to investigate the interpretations of impact put forward via impact case studies in the REF process. We find that institutions have developed a diverse interpretation of impact, ranging from commercial applications to public and cultural engagement activities. These interpretations of impact vary from discipline to discipline and between institutions, with more broad-based institutions depicting a greater variety of impacts. Comparing the interpretations with the score given by REF, we found no evidence of one particular interpretation being more highly rewarded than another. Importantly, we also found a positive correlation between impact score and [overall research] quality score, suggesting that impact is not being achieved at the expense of research excellence.

Accounting for the environment as an economic asset: global progress and realizing the 2030 Agenda for Sustainable Development

National and international efforts to develop natural capital accounts are proliferating. The newly agreed 2030 Agenda for Sustainable Development echoes these efforts. Continued cooperation is needed to overcome key scientific and policy challenges.

Correction: Beyond Academia – Interrogating Research Impact in the Research Excellence Framework

[This corrects the article DOI: 10.1371/journal.pone.0168533.].

Resilient sustainable cities - a future, edited by Leonie J. Pearson, Peter W. Newton and Peter Roberts, New York, Routledge, 2014, xii + 254 pp., £24.99 (paperback), ISBN 978-0-415-81621-2 / £105.00 (hardback), ISBN 978-0-415-81620-5

useful in recognising how branding and public relations exercises in local government are negotiated and how certain ‘classic’ case studies of community cohesion have come to shape both local and national concerns and expectations. Chapter six and the concluding chapter seven deal with the kind of reflexive tensions that policy practitioners negotiate with and how personal identities and experiences shape and get shaped by their work. These chapters provide a good critical reading of how people understand change and the internal dilemmas of working in a complex policy environment. Here the author is attentive to both what is said and not said in how people negotiate these processes, and she concludes by reemphasising that policy practitioners must recognise and embrace such tensions in their work and that ‘emotions matter’ when thinking about how power and practice work. Indeed, a key insight of the book is how ‘recognising the role of emotion in governing belonging, identity and inequality is essential because power relations are experienced through emotional, embodied registers’ (168). Overall, this book is a thoughtful, first-hand account of the challenges of defining and negotiating community cohesion and provides a number of useful directions with which to explore the recent history and geography of community cohesion policy in local government across England. If there are criticisms of the book, it perhaps suffers slightly from a lack of coherent progression between the chapters and headings, and at certain stages of the empirical chapters, it feels like the analysis does not always fit the evidence the author supports it with (Jones’ formulation of the narratives appears at times overly construed from participants’ responses). This book is not a practical guide to addressing community cohesion policy and in some ways puts more grit in the oyster for designing better policy practice in local government. But it does present a very useful conceptual and empirical mapping of how policy practitioners are experiencing this type of work, and thus challenges readers, both academic and nonacademic, to reconsider the complexity of policy production and the management of social change in local areas.