1,012 research outputs found

    Visual, Motor and Attentional Influences on Proprioceptive Contributions to Perception of Hand Path Rectilinearity during Reaching

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    We examined how proprioceptive contributions to perception of hand path straightness are influenced by visual, motor and attentional sources of performance variability during horizontal planar reaching. Subjects held the handle of a robot that constrained goal-directed movements of the hand to the paths of controlled curvature. Subjects attempted to detect the presence of hand path curvature during both active (subject driven) and passive (robot driven) movements that either required active muscle force production or not. Subjects were less able to discriminate curved from straight paths when actively reaching for a target versus when the robot moved their hand through the same curved paths. This effect was especially evident during robot-driven movements requiring concurrent activation of lengthening but not shortening muscles. Subjects were less likely to report curvature and were more variable in reporting when movements appeared straight in a novel “visual channel” condition previously shown to block adaptive updating of motor commands in response to deviations from a straight-line hand path. Similarly, compromised performance was obtained when subjects simultaneously performed a distracting secondary task (key pressing with the contralateral hand). The effects compounded when these last two treatments were combined. It is concluded that environmental, intrinsic and attentional factors all impact the ability to detect deviations from a rectilinear hand path during goal-directed movement by decreasing proprioceptive contributions to limb state estimation. In contrast, response variability increased only in experimental conditions thought to impose additional attentional demands on the observer. Implications of these results for perception and other sensorimotor behaviors are discussed

    Durkheim’s Greatest Blunder

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    In describing fatalism in Suicide, Durkheim executes two blunders. The first can be categorized in errors of commission while the second should be included in errors of omission. In the error of commission area, he hypothesizes two platforms for existence of fatalistic suicide. Without employing theory-embedded data, he contends that infertility is a catalyst for fatalistic suicidal. Later, he asserts that slavery is fertile soil for fatalistic suicide. Although there is suicidal data in these two arenas, a closer inspection demonstrates that these are not characteristics of fatalistic suicide. For errors of omission, he failed to systematically observe two social factors for which data was available during his time of study. Poverty and poor health existed in a social environment which is best described by Durkheim’s vision of fatalistic suicide. He missed observing and collecting the available data to lend support for the empirical existence of fatalistic suicide. These four social factors are discussed

    Turnitin said it wasn't happy: Can the regulatory discourse of plagiarism detection operate as a change artefact for writing development?

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    This paper centres on the tensions between the introduction of plagiarism detection software (Turnitin) for student and tutor use at undergraduate level and the aim to promote a developmental approach to writing for assessment at a UK university. Aims to promote developmental models for writing often aim to counteract the effects of the structural organisation of learning and assessment in higher education. This paper will discuss the potential for the implementation of plagiarism detection software to operate as a 'change artefact', creating opportunities for a departure from the habits of practice created by the demands of writing for assessment and the potential for the emergence of enclaves of good practice in respect of writing development. Tutor and student qualitative responses, gathered via questionnaires and focus groups were analysed in order to investigate the effectiveness of this initiative. In this inquiry plagiarism detection emerges as a dominant theme within regulatory discourses of malpractice in higher education. The promotion of writing development via a tool for regulation and plagiarism detection seems to be a mismatch and the extent to which Turnitin can be operate as a change artefact to promote developmental approaches to writing for assessment in higher education is questioned. The suitability of plagiarism detection software as a tool to promote writing development will be discussed in light of the findings from this inquiry

    Self-stigma and weight loss: The impact of fear of being stigmatized

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    The current study sought to examine whether two facets of weight self-stigma (fear of enacted stigma and self-devaluation) were associated with weight change and treatment engagement for 188 individuals participating in a 3-month online weight loss program. Fear of enacted stigma predicted less weight loss 3-months later after controlling for demographics, eating problems, and psychological symptoms. Self-devaluation did not predict weight loss. Neither weight self-stigma variable predicted engagement in the online program. These results add to the literature indicating the negative effects of weight self-stigma while highlighting the central role of fear of being stigmatized by others in this process

    Pockets of Proterozoic hydrocarbons and implications for the Archaean

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    Precambrian biomarkers convey invaluable information about the early evolution of life, ancient ecosystems, redox conditions, climate and depositional environment and prospective petroleum systems. They are however thermally unstable, easily obliterated by contamination and thus extremely difficult to find. This is particularly true if conditions favourable for biomarker preservation had to prevail for more than 2.5 billion years – the prerequisite for finding Archaean biomarkers. Many organic geochemists abandoned this hope after original discoveries of Archaean biomarkers proved to be of younger origin [1,2] but our study of ca. 550-825 Ma old sediments from the Centralian Superbasin now shows that biomarkers can be preserved in distinctive pockets in seemingly barren areas, even if sections are metamorphosed in parts. Most Centralian sections seem empty. Yet, eventually we identified intervals with preserved biomarkers in three drill cores. A detailed investigation of 825 Ma sediments in drill core Mt Charlotte-1 revealed maturity variations that are most likely due to hydrothermal influence and in turn control the hydrocarbon preservation. Sediments might appear metamorphosed after localized, subtle alteration by hydrothermal fluids but protected intervals can still contain biomarkers. The same might be true for Archaean sediments and we might still find those protected intervals with indigenous biomarkers that allow us to glimpse the early life on earth

    Making judgements about students making work : lecturers’ assessment practices in art and design.

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    This research study explores the assessment practices in two higher education art and design departments. The key aim of this research was to explore art and design studio assessment practices as lived by and experienced by art and design lecturers. This work draws on two bodies of pre existing research. Firstly this study adopted innovative methodological approaches that have been employed to good effect to explore assessment in text based subjects (think aloud) and moderation mark agreement (observation). Secondly the study builds on existing research into the assessment of creative practice. By applying thinking aloud methodologies into a creative practice assessment context the authors seek to illuminate the ‘in practice’ rather than espoused assessment approaches adopted. The analysis suggests that lecturers in the study employed three macro conceptions of quality to support the judgement process. These were; the demonstration of significant learning over time, the demonstration of effective studentship and the presentation of meaningful art/design work
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