2,248 research outputs found

    Reluctance Accelerator Efficiency Optimization via Pulse Shaping

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    Reluctance accelerators are used to apply linear forces to ferromagnetic projectiles via solenoids. Ef ciency increases for a single-stage reluctance accelerator were produced by manipulating the input current pulse supplied by a discharging capacitor. The development of a theoretical model allowed for the calculation of optimized pulse shapes. A digital pulsewidth modulated switching method was used to control the current pulse shape using an Arduino Uno microcontroller, which supplied signals to the gate of a MOSFET transistor that controlled the current to the system solenoid. An ef ciency increase of 5.7% was obtained for a reluctance accelerator with an optimized current pulse shape in comparison to a capacitor discharge with no pulse shapin

    Spectroscopic Confirmation of a Protocluster at z=3.786

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    We present new observations of the field containing the z=3.786 protocluster, PC217.96+32.3. We confirm that it is one of the largest and most overdense high-redshift structures known. Such structures are rare even in the largest cosmological simulations. We used the Mayall/MOSAIC1.1 imaging camera to image a 1.2x0.6 deg area (~150x75 comoving Mpc) surrounding the protocluster's core and discovered 165 candidate Lyman Alpha emitting galaxies (LAEs) and 788 candidate Lyman Break galaxies (LBGs). There are at least 2 overdense regions traced by the LAEs, the largest of which shows an areal overdensity in its core (i.e., within a radius of 2.5 comoving Mpc) of 14+/-7 relative to the average LAE spatial density in the imaged field. Further, the average LAE spatial density in the imaged field is twice that derived by other field LAE surveys. Spectroscopy with Keck/DEIMOS yielded redshifts for 164 galaxies (79 LAEs and 85 LBGs); 65 lie at a redshift of 3.785+/-0.010. The velocity dispersion of galaxies near the core is 350+/-40 km/s, a value robust to selection effects. The overdensities are likely to collapse into systems with present-day masses of >10^{15} solar masses and >6x10^{14} solar masses. The low velocity dispersion may suggest a dynamically young protocluster. We find a weak trend between narrow-band (Lyman Alpha) luminosity and environmental density: the Lyman Alpha luminosity is enhanced on average by 1.35X within the protocluster core. There is no evidence that the Lyman Alpha equivalent width depends on environment. These suggest that star-formation and/or AGN activity is enhanced in the higher density regions of the structure. PC217.96+32.3 is a Coma cluster analog, witnessed in the process of formation.Comment: Accepted for publication in the Astrophysical Journal (March 27, 2016

    Heritage branding orientation: The case of Ach. Brito and the dynamics between corporate and product heritage brands

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    The notion of heritage branding orientation is introduced and explicated. Heritage branding orientation is designated as embracing both product and corporate brands and differs from corporate heritage brand orientation which has an explicit corporate focus. Empirical insights are drawn from an in-depth and longitudinal case study of Ach. Brito, a celebrated Portuguese manufacturer of soaps and toiletries. This study shows how, by the pursuance of a strategy derived from a heritage branding orientation Ach. Brito – after a prolonged period of decline – achieved a dramatic strategic turnaround. The findings reveal how institutional heritage can be a strategic resource via its adoption and activation at both the product and corporate levels. Moreover, the study showed how the bi-lateral interplay between product and corporate brand levels can be mutually reinforcing. In instrumental terms, the study shows how heritage can be activated and articulated in different ways. For instance, it can re-position both product and/or corporate brands; it can be meaningfully informed by product brand heritage and shape corporate heritage; and can be of strategic importance to both medium-sized and small enterprises

    Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

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    The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses

    A meta-analytic review of stand-alone interventions to improve body image

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    Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

    A Comparative Exploration of Community Pharmacists' Views on the Nature and Management of Over-the-Counter (OTC) and Prescription Codeine Misuse in Three Regulatory Regimes: Ireland, South Africa and the United Kingdom

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    Misuse of codeine containing preparations is a public health concern given the potential for associated harms and dependence. This study explores the perspectives of community pharmacists in three regulatory regimes on issues of customer misuse of over-the-counter (OTC) and prescribed codeine. A qualitative design comprising six focus groups (n = 45) was conducted in Ireland, United Kingdom, South Africa. Transcripts were analysed using the constant comparative method of content analysis. Pharmacists described popular codeine-containing products and the need for improved medicine information and warning labels. Issues around legitimate availability of codeine and regulatory status; presence of therapeutic need; difficulties in customer–pharmacist communication; business environments and retail focus were raised. Participants also discussed how they identified customers potentially misusing codeine and difficulties in relationships between pharmacists and prescribers. A number of recommendations were put forward as ways to manage the issues. The study highlights the difficulties encountered by community pharmacists operating under various regulatory regimes when supplying codeine containing preparations in negotiating patient awareness and compliance and potential ways to deal with misuse and dependence

    Prime movers : mechanochemistry of mitotic kinesins

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    Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation

    WNT signalling in prostate cancer

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    Genome sequencing and gene expression analyses of prostate tumours have highlighted the potential importance of genetic and epigenetic changes observed in WNT signalling pathway components in prostate tumours-particularly in the development of castration-resistant prostate cancer. WNT signalling is also important in the prostate tumour microenvironment, in which WNT proteins secreted by the tumour stroma promote resistance to therapy, and in prostate cancer stem or progenitor cells, in which WNT-β-catenin signals promote self-renewal or expansion. Preclinical studies have demonstrated the potential of inhibitors that target WNT receptor complexes at the cell membrane or that block the interaction of β-catenin with lymphoid enhancer-binding factor 1 and the androgen receptor, in preventing prostate cancer progression. Some WNT signalling inhibitors are in phase I trials, but they have yet to be tested in patients with prostate cancer
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