223 research outputs found

    Political activism across the life course

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    The study of political activism has neglected people’s personal and social relationships to time. Age, life course and generation have become increasing important experiences for understanding political participation and political outcomes (e.g. Brexit), and current policies of austerity across the world are affecting people of all ages. At a time when social science is struggling to understand the rapid and unexpected changes to the current political landscape, the essay argues that the study of political activism can be enriched by engaging with the temporal dimensions of people’s everyday social experiences because it enables the discovery of political activism in mundane activities as well as in banal spaces. The authors suggest that a values-based approach that focuses on people’s relationships of concern would be a suitable way to surface contemporary political sites and experiences of activism across the life course and for different generations

    The nature of singlet exciton fission in carotenoid aggregates.

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    Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has the potential to improve organic photovoltaics, enabling efficient coupling to the blue to ultraviolet region of the solar spectrum to capture the energy generally lost as waste heat. However, many questions remain about the underlying fission mechanism. The relation between intermolecular geometry and singlet fission rate and yield is poorly understood and remains one of the most significant barriers to the design of new singlet fission sensitizers. Here we explore the structure-property relationship and examine the mechanism of singlet fission in aggregates of astaxanthin, a small polyene. We isolate five distinct supramolecular structures of astaxanthin generated through self-assembly in solution. Each is capable of undergoing intermolecular singlet fission, with rates of triplet generation and annihilation that can be correlated with intermolecular coupling strength. In contrast with the conventional model of singlet fission in linear molecules, we demonstrate that no intermediate states are involved in the triplet formation: instead, singlet fission occurs directly from the initial 1B(u) photoexcited state on ultrafast time scales. This result demands a re-evaluation of current theories of polyene photophysics and highlights the robustness of carotenoid singlet fission.This work was supported by the EPSRC (UK) (EP/G060738/ 1), the European Community (LASERLAB-EUROPE, grant agreement no. 284464, EC’s Seventh Framework Programme; and Marie-Curie ITN-SUPERIOR, PITN-GA-2009-238177), and the Winton Programme for the Physics of Sustainability. G.C. acknowledges support by the European Research Council Advanced Grant STRATUS (ERC-2011-AdG No. 291198). J.C. acknowledges support by the Royal Society Dorothy Hodgkin Fellowship and The University of Sheffield’s Vice- Chancellor’s Fellowship scheme.This is the final published version. It was first made available by ACS at http://pubs.acs.org/doi/abs/10.1021/jacs.5b01130

    Look Who’s Talking:Using creative, playful arts-based methods in research with young children

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    Young children are often ignored or marginalised in the drive to address children’s participation and their wider set of rights. This is the case generally in social research, as well as within the field of Arts-Based Education Research. This article contributes to the growing literature on young children’s involvement in arts-based research, by providing a reflective account of our learning and playful engagement with children using creative methods. This small pilot project forms part of a larger international project titled Look Who’s Talking: Eliciting the Voices of Children from Birth to Seven, led by Professor Kate Wall at the University of Strathclyde. Visiting one nursery in Scotland, we worked with approximately 30 children from 3 to 5 years old. Seeking to connect with their play-based nursery experiences, we invited children to participate in a range of arts-based activities including drawing, craft-making, sculpting, a themed ‘play basket’ with various props, puppetry and videography. In this article, we develop reflective, analytical stories of our successes and dilemmas in the project. We were keen to establish ways of working with children that centred their own creativity and play, shaped by the materials we provided but not directed by us. However, we struggled to balance our own agenda with the more open-ended methods we had used. We argue that an intergenerational approach to eliciting voice with young children – in which adults are not afraid to shape the agenda, but do so in responsive, gradual and sensitive ways – creates the potential for a more inclusive experience for children that also meets researcher needs

    Automatic Robust Neurite Detection and Morphological Analysis of Neuronal Cell Cultures in High-content Screening

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    Cell-based high content screening (HCS) is becoming an important and increasingly favored approach in therapeutic drug discovery and functional genomics. In HCS, changes in cellular morphology and biomarker distributions provide an information-rich profile of cellular responses to experimental treatments such as small molecules or gene knockdown probes. One obstacle that currently exists with such cell-based assays is the availability of image processing algorithms that are capable of reliably and automatically analyzing large HCS image sets. HCS images of primary neuronal cell cultures are particularly challenging to analyze due to complex cellular morphology. Here we present a robust method for quantifying and statistically analyzing the morphology of neuronal cells in HCS images. The major advantages of our method over existing software lie in its capability to correct non-uniform illumination using the contrast-limited adaptive histogram equalization method; segment neuromeres using Gabor-wavelet texture analysis; and detect faint neurites by a novel phase-based neurite extraction algorithm that is invariant to changes in illumination and contrast and can accurately localize neurites. Our method was successfully applied to analyze a large HCS image set generated in a morphology screen for polyglutaminemediated neuronal toxicity using primary neuronal cell cultures derived from embryos of a Drosophila Huntington’s Disease (HD) model.National Institutes of Health (U.S.) (Grant

    Linking Symptom Inventories using Semantic Textual Similarity

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    An extensive library of symptom inventories has been developed over time to measure clinical symptoms, but this variety has led to several long standing issues. Most notably, results drawn from different settings and studies are not comparable, which limits reproducibility. Here, we present an artificial intelligence (AI) approach using semantic textual similarity (STS) to link symptoms and scores across previously incongruous symptom inventories. We tested the ability of four pre-trained STS models to screen thousands of symptom description pairs for related content - a challenging task typically requiring expert panels. Models were tasked to predict symptom severity across four different inventories for 6,607 participants drawn from 16 international data sources. The STS approach achieved 74.8% accuracy across five tasks, outperforming other models tested. This work suggests that incorporating contextual, semantic information can assist expert decision-making processes, yielding gains for both general and disease-specific clinical assessment

    Imaging the boundaries—innovative tools for microscopy of living cells and real-time imaging

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    Recently, light microscopy moved back into the spotlight, which is mainly due to the development of revolutionary technologies for imaging real-time events in living cells. It is truly fascinating to see enzymes “at work” and optically acquired images certainly help us to understand biological processes better than any abstract measurements. This review aims to point out elegant examples of recent cell-biological imaging applications that have been developed with a chemical approach. The discussed technologies include nanoscale fluorescence microscopy, imaging of model membranes, automated high-throughput microscopy control and analysis, and fluorescent probes with a special focus on visualizing enzyme activity, free radicals, and protein–protein interaction designed for use in living cells
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