69 research outputs found

    On the uncertain future of the volumetric 3D display paradigm.

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    Volumetric displays permit electronically processed images to be depicted within a transparent physical volume and enable a range of cues to depth to be inherently associated with image content. Further, images can be viewed directly by multiple simultaneous observers who are able to change vantage positions in a natural way. On the basis of research to date, we assume that the technologies needed to implement useful volumetric displays able to support translucent image formation are available and so primarily focus on other issues that have impeded the broad commercialization and application of this display paradigm. This is of particular relevance given the recent resurgence of interest in developing commercially viable, general purpose, volumetric systems. We particularly consider image and display characteristics, usability issues and identify several advantageous attributes that need to be exploited in order to effectively capitalize on this display modality.N/

    Potential implications of differential preservation of testate amoeba shells for paleoenvironmental reconstruction in peatlands

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    Testate amoebae are now commonly used in paleoenvironmental studies but little is known of their taphonomy. There is some experimental evidence for differential preservation of some testate amoeba shell types over others, but it is unclear what, if any impact this has on palaeoenvironmental reconstruction. To investigate this issue we looked at palaeoecological evidence for the preservation of different shell types. We then investigated the possible impact of selective preservation on quantitative palaeoenvironmental inference. We first used existing palaeoecological data sets to assess the vertical patterns of relative abundance in four testate amoeba shell types: (1) shells made of secreted biosilica plates (idiosomes, e.g. Euglypha), (2) idiosomes with thick organic coating (Assulina), (3) proteinaceous shells (e.g. Hyalosphenia), (4) shells built from recycled organic or mineral particles (xenosomes) (e.g. Difflugia, Centropyxis). In three diagrams a clear pattern of decay was only observed for the idiosome type. In order to assess the implications of differential preservation of testate amoeba taxa for paleoenvironmental reconstruction we then carried out simulations using three existing transfer functions and a wide range of scenarios, downweighting different test categories to represent the impact of selective test decomposition. Simulation results showed that downweighting generally reduced overall model performance. However downweighting a shell type only produced a consistent directional bias in inferred water table depth where that shell type is both dominant and shows a clear preference along the ecological gradient. Applying a scenario derived from previous experimental work did not lead to significant difference in inferred water table. Our results show that differential shell preservation has little impact on paleohydrological reconstruction from Sphagnum-dominated peatlands. By contrast, for the minerotrophic peatlands data-set loss of idiosome tests leads to consistent underestimation of water table depth. However there are few studies from fens and it is possible that idiosome tests are not always dominant, and/or that differential decomposition is less marked than in Sphagnum peatlands. Further work is clearly needed to assess the potential of testate amoebae for paleoecological studies of minerotrophic peatlands

    Foreign ownership, bank information environments, and the international mobility of corporate governance

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    This paper investigates how foreign ownership shapes bank information environments. Using a sample of listed banks from 60 countries over 1997–2012, we show that foreign ownership is significantly associated with greater (lower) informativeness (synchronicity) in bank stock prices. We also find that stock returns of foreign-owned banks reflect more information about future earnings. In addition, the positive association between price informativeness and foreign ownership is stronger for foreign-owned banks in countries with stronger governance, stronger banking supervision, and lower monitoring costs. Overall, our evidence suggests that foreign ownership reduces bank opacity by exporting governance, yielding important implications for regulators and governments

    The impact of an "equal opportunities" ideological framework on coaches’ knowledge and practice

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    This study focuses upon UK professional coaches’ experiences of equity training and the impact of the conceptualisation of equity as a matter of equal opportunities on this education and subsequent coaching practice. The research employs a critical feminist approach to connect the ideological framing of gender equity by sporting organisations to coaches’ ability to understand, identify and manage issues of gender equity, equality and diversity. The discussions are based on interviews with four coaches, Jack, Peter, Charlotte and Tony, who had all recently undertaken equity training, and all of whom represented sports and different stages of the coaching pathway. The data highlights that seeing gender equity through an “equal opportunities” lens results in a narrow conceptualisation of such issues by coaches, fails to challenge dominant and discriminative ideologies, and does not enable coaches to address equity within their practices. Consequently, coaches struggle to understand the importance of and manage such issues. The participants’ experiences reveal that gender relations, intersected principally with religion and ethnicity, underpinned their everyday coaching practices. The findings illustrate the need for sporting organisations to redefine how they approach equality and equity and for a more sophisticated sociocultural educational programme for coaches

    Effort-related functions of nucleus accumbens dopamine and associated forebrain circuits

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    Background Over the last several years, it has become apparent that there are critical problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Hypotheses related to DA function are undergoing a substantial restructuring, such that the classic emphasis on hedonia and primary reward is giving way to diverse lines of research that focus on aspects of instrumental learning, reward prediction, incentive motivation, and behavioral activation. Objective The present review discusses dopaminergic involvement in behavioral activation and, in particular, emphasizes the effort-related functions of nucleus accumbens DA and associated forebrain circuitry. Results The effects of accumbens DA depletions on food-seeking behavior are critically dependent upon the work requirements of the task. Lever pressing schedules that have minimal work requirements are largely unaffected by accumbens DA depletions, whereas reinforcement schedules that have high work (e.g., ratio) requirements are substantially impaired by accumbens DA depletions. Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related decision making. Rats with accumbens DA depletions reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and instead, these rats select a less-effortful type of food-seeking behavior. Conclusions Along with prefrontal cortex and the amygdala, nucleus accumbens is a component of the brain circuitry regulating effort-related functions. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as energy-related disorders such as psychomotor slowing, fatigue, or anergia in depression

    Ethical and professional issues: transcending the obstacles to student engagement

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    It is vitally important that today’s technology-related degree programs provide undergraduate students with the skills needed to appreciate and assess the often complex ways in which digital systems may impact on the individual, society, and the environment. This paper outlines current approaches adopted by the authors towards significantly enhancing the teaching of Ethical and Professional Issues. Particular attention is given to curriculum development (in which a strong people-centric, research-infused approach is adopted), and to the integration of technologies into many aspects of the teaching process. These developments are considered in the context of enhanced student engagement and in terms of fostering an ethos in which students are encouraged to establish a personal ethical position in relation to the application and deployment of digital systems

    Volumetric 3D displays.

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    Volumetric displays enable electronically processed images to be depicted within a transparent volume, and so they are able to occupy three spatial dimensions. A broad range of depth cues are inherently associated with such images, including the parallax and oculomotor cues. Accommodation-convergence breakdown and depth cue conflict are avoided. Here we review aspects of this display modality, identify various key characteristics, and refer to a number of exemplar technologies. Brief consideration is given to the formation of opaque images and the implementation of an ethereal form of image space.n/
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