6,303 research outputs found

    Overcoming the false-minima problem in direct methods: Structure determination of the packaging enzyme P4 from bacteriophage φ13

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    The problems encountered during the phasing and structure determination of the packaging enzyme P4 from bacteriophage φ13 using the anomalous signal from selenium in a single-wavelength anomalous dispersion experiment (SAD) are described. The oligomeric state of P4 in the virus is a hexamer (with sixfold rotational symmetry) and it crystallizes in space group C2, with four hexamers in the crystallographic asymmetric unit. Current state-of-the-art ab initio phasing software yielded solutions consisting of 96 atoms arranged as sixfold symmetric clusters of Se atoms. However, although these solutions showed high correlation coefficients indicative that the substructure had been solved, the resulting phases produced uninterpretable electron-density maps. Only after further analysis were correct solutions found (also of 96 atoms), leading to the eventual identification of the positions of 120 Se atoms. Here, it is demonstrated how the difficulties in finding a correct phase solution arise from an intricate false-minima problem. © 2005 International Union of Crystallography - all rights reserved

    Collaboration and organisational learning: A study of a New Zealand collaborative research programme

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    Collaboration with a research partner is one strategy that small and medium sized enterprises (SMEs) can pursue to counter their size-imposed research and development (R&D) resource and capacity constraints and to enhance their learning. The Technology for Business Growth (TBG) programme supports collaborative R&D projects between New Zealand industry and research institutions. This research attempted to gauge the effects of participation in a collaborative project on broader aspects of organisational learning, on the industry managers' subsequent attitudes towards R&D, as well as managers' perceptions of success and failure factors for collaboration. The majority of managers stated that their attitude to R&D had not changed (it was already positive prior to the project). However, their organisation's attitude towards the management of R&D projects had often changed, with many companies adopting the practices of project evaluation and planning enforced by the TBG application process, thus providing considerable evidence that organisational learning had taken place. Objective measures of subsequent R&D activity, such as increased spending on, and number of, R&D projects and increased employment of technical staff provide further evidence that the companies' learning experiences with collaborative projects may have encouraged them to invest more readily in R&D

    Involving Lived Experience in regional efforts to address gambling-related harms: going beyond ‘window dressing’ and ‘tick box exercises’

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    Background Lived Experience (LE) involvement has been shown to improve interventions across diverse sectors. Yet LE contributions to public health approaches to address gambling-related harms remain underexplored, despite notable detrimental health and social outcomes linked to gambling. This paper analyses the potential of LE involvement in public health strategy to address gambling-related harms. It focuses on the example of a UK city-region gambling harms reduction intervention that presented multiple opportunities for LE input. Methods Three focus groups and 33 semi-structured interviews were conducted to hear from people with and without LE who were involved in the gambling harms reduction intervention, or who had previous experience of LE-informed efforts for addressing gambling-related harms. People without LE provided reflections on the value and contributions of others’ LE to their work. Data analysis combined the Framework Method with themes developed inductively (from people’s accounts) and deductively (from the literature, including grey literature). Results Four themes were identified: (1) personal journeys to LE involvement; (2) the value added by LE to interventions for addressing gambling-related harms; (3) emotional impacts on people with LE; and (4) collective LE and diverse lived experiences. Two figures outlining LE involvement specific to gambling harms reduction in the UK, where public health efforts aimed at addressing gambling-related harms coexist with industry-funded programmes, are proposed. Conclusions Integrating a range of LE perspectives in a public health approach to gambling harms reduction requires local access to involvement for people with LE via diverse routes that are free from stigma and present people with LE with options in how they can engage and be heard in decision-making, and how they operate in relation to industry influence. Involving LE in gambling harms reduction requires enabling people to develop the affective and critical skills necessary to navigate complex emotional journeys and a challenging commercial and policy environment

    Microwave Absorption of Surface-State Electrons on Liquid 3^3He

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    We have investigated the intersubband transitions of surface state electrons (SSE) on liquid 3^3He induced by microwave radiation at temperatures from 1.1 K down to 0.01 K. Above 0.4 K, the transition linewidth is proportional to the density of 3^3He vapor atoms. This proportionality is explained well by Ando's theory, in which the linewidth is determined by the electron - vapor atom scattering. However, the linewidth is larger than the calculation by a factor of 2.1. This discrepancy strongly suggests that the theory underestimates the electron - vapor atom scattering rate. At lower temperatures, the absorption spectrum splits into several peaks. The multiple peak structure is partly attributed to the spatial inhomogeneity of the static holding electric field perpendicular to the electron sheet.Comment: 15 pages, 7 figures, submitted to J. Phys. Soc. Jp

    Crew Motion and the Dynamic Environment of Spaceborne Experiments

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    Analytical study of crew motion on dynamic environment of orbiting laboratorie

    Probing the extreme realm of AGN feedback in the massive galaxy cluster, RX J1532.9+3021

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    We present a detailed Chandra, XMM-Newton, VLA and HST analysis of one of the strongest cool core clusters known, RX J1532.9+3021 (z=0.3613). Using new, deep 90 ks Chandra observations, we confirm the presence of a western X-ray cavity or bubble, and report on a newly discovered eastern X-ray cavity. The total mechanical power associated with these AGN-driven outflows is (22+/-9)*10^44 erg/s, and is sufficient to offset the cooling, indicating that AGN feedback still provides a viable solution to the cooling flow problem even in the strongest cool core clusters. Based on the distribution of the optical filaments, as well as a jet-like structure seen in the 325 MHz VLA radio map, we suggest that the cluster harbours older outflows along the north to south direction. The jet of the central AGN is therefore either precessing or sloshing-induced motions have caused the outflows to change directions. There are also hints of an X-ray depression to the north aligned with the 325 MHz jet-like structure, which might represent the highest redshift ghost cavity discovered to date. We further find evidence of a cold front (r=65kpc) that coincides with the outermost edge of the western X-ray cavity and the edge of the radio mini-halo. The common location of the cold front with the edge of the radio mini-halo supports the idea that the latter originates from electrons being reaccelerated due to sloshing induced turbulence. Alternatively, its coexistence with the edge of the X-ray cavity may be due to cool gas being dragged out by the outburst. We confirm that the central AGN is highly sub-Eddington and conclude that a >10^10M_Sun or a rapidly spinning black hole is favoured to explain both the radiative-inefficiency of the AGN and the powerful X-ray cavities.Comment: Accepted for publication to ApJ (minor corrections), 16 pages, 16 figures, 5 tables. Full resolution at http://www.stanford.edu/~juliehl/M1532

    Harnessing lived experience in a community-based intervention to address gambling-related harms

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    Background Lived experience of people directly or indirectly affected by public health issues can provide unique insights into how to improve interventions. Increasing availability of gambling necessitates involving communities in efforts to reduce gambling-related harms. This presentation reports qualitative exploratory research into the value of lived experience across a city-region gambling harm reduction initiative in the UK. Methods Focus groups and interviews were used to explore the practical application of lived experience with participants: advisory panel members, external stakeholders, community project staff, and public health professionals. Collaborative data analysis combined the framework method with theme development inductively (from participants’ accounts) and deductively (from academic and grey literature). Results Four themes were identified: (1) lived experience spans formal and informal settings with different activities and personal impacts; (2) organic and structured pathways to lived experience involvement coexist; (3) the emotional work of people affected by gambling-related harms ranges from frustration at policy inertia to deeper understanding of their own recovery journey; and (4) lived experience encompasses diverse experiential knowledges. Conclusions Involving lived experience in this intervention increased participants’ awareness of the harmful role of the gambling industry and critical reflection on the representativeness of lived experience. Harnessing lived experience at a regional level requires multi-setting support free from stigma and industry influence to ensure the sustained vitality of a diverse lived experience community specialised in gambling-related harms and equipped to navigate conflicting emotions and a challenging policy environment. Key messages • Increasing availability of gambling necessitates involving communities in efforts to reduce gambling-related harms. • The use of lived experience in gambling-related harms prevention efforts and research can inform intervention development
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