315 research outputs found

    The learning curves of a validated virtual reality hip arthroscopy simulator

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    Abstract: Introduction: Decreases in trainees’ working hours, coupled with evidence of worse outcomes when hip arthroscopies are performed by inexperienced surgeons, mandate an additional means of training. Though virtual reality simulation has been adopted by other surgical specialities, its slow uptake in arthroscopic training is due to a lack of evidence as to its benefits. These benefits can be demonstrated through learning curves associated with simulator training—with practice reflecting increases in validated performance metrics. Methods: Twenty-five medical students with no previous experience of hip arthroscopy completed seven weekly simulated arthroscopies of a healthy virtual hip joint using a 70° arthroscope in the supine position. Twelve targets were visualised within the central compartment, six via the anterior portal, three via the anterolateral portal and three via the posterolateral portal. Task duration, number of collisions (bone and soft-tissue), and distance travelled by arthroscope were measured by the simulator for every session of each student. Results: Learning curves were demonstrated by the students, with improvements in time taken, number of collisions (bone and soft-tissue), collision length and efficiency of movement (all p < 0.01). Improvements in time taken, efficiency of movement and number of collisions with soft-tissue were first seen in session 3 and improvements in all other parameters were seen in session 4. No differences were found after session 5 for time taken and length of soft-tissue collision. No differences in number of collisions (bone and soft-tissue), length of collisions with bone, and efficiency of movement were found after session 6. Conclusions: The results of this study demonstrate learning curves for a hip arthroscopy simulator, with significant improvements seen after three sessions. All performance metrics were found to improved, demonstrating sufficient visuo-haptic consistency within the virtual environment, enabling individuals to develop basic arthroscopic skills

    Does the universe in fact contain almost no information?

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    At first sight, an accurate description of the state of the universe appears to require a mind-bogglingly large and perhaps even infinite amount of information, even if we restrict our attention to a small subsystem such as a rabbit. In this paper, it is suggested that most of this information is merely apparent, as seen from our subjective viewpoints, and that the algorithmic information content of the universe as a whole is close to zero. It is argued that if the Schr\"odinger equation is universally valid, then decoherence together with the standard chaotic behavior of certain non-linear systems will make the universe appear extremely complex to any self-aware subsets that happen to inhabit it now, even if it was in a quite simple state shortly after the big bang. For instance, gravitational instability would amplify the microscopic primordial density fluctuations that are required by the Heisenberg uncertainty principle into quite macroscopic inhomogeneities, forcing the current wavefunction of the universe to contain such Byzantine superpositions as our planet being in many macroscopically different places at once. Since decoherence bars us from experiencing more than one macroscopic reality, we would see seemingly complex constellations of stars etc, even if the initial wavefunction of the universe was perfectly homogeneous and isotropic.Comment: 17 pages, LATeX, no figures. Online with refs at http://astro.berkeley.edu/~max/nihilo.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/nihilo.html (faster from Europe) or from [email protected]

    Psychopathology and affect dysregulation across the continuum of psychosis: A multiple comparison group study

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    This is the peer reviewed version of the following article: Taylor, H. E., Stewart, S. L. K., Dunn, G., Parker, S., Bentall, R. P., Birchwood, M., & Morrison, A. P. (2014). Psychopathology and affect dysregulation across the continuum of psychosis: A multiple group comparison study. Early Intervention in Psychiatry, 8(3), 221-228. DOI: 10.1111/eip.12064, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/eip.12064/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingAim: There is evidence that psychotic-like phenomena can be detected within the general population and that psychotic experiences lie on a continuum which also spans affective states. We aimed to investigate comparisons of a first episode psychosis group, an ‘at-risk mental state group’ and a help-seeking control group with non-patients to explore whether affective states lie on a continuum of psychosis. Method: Measures of psychotic-like experiences, social anxiety and depression were administered to 20 patients experiencing first episode psychosis (FEP), 113 patients experiencing an ‘at-risk’ mental state (ARMS), 28 patients who were help-seeking but not experiencing a FEP or ARMS (HSC) and 30 non-clinical participants (NC). Results: For distress in relation to psychotic-like experiences, the FEP, ARMS and HSC groups scored significantly higher than the NC group for the perceptual abnormalities and non-bizarre ideas. In terms of severity of psychotic experiences, the FEP scored the highest, followed by the ARMS group, followed by the HSC and NC group. The clinical groups scored significantly higher for depression than the non-clinical group. Interestingly, only the FEP and the ARMS group scored significantly higher than non-patients for social anxiety. Conclusions: These findings suggest that a psychosis continuum exists, however this does not suggest that both psychosis and affective symptoms lie on the same continuum, rather it would appear that the presence of such affective states that may affect help-seeking behavior and clinical status. The implications of these findings for clinical practice are discussed

    Villages and Urbanization

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    In this article comments by politician Boris Johnson and economist Edward Glaeser exemplify narratives of global urbanization that portray rural villages as redundant and perpetuate outdated notions of urban–rural division. Simultaneously, traditional urban–rural dialectics are distorted by divisive new urban projects like gated communities styled as villages. This paper argues for development models that acknowledge the vital environmental and economic roles played by rural villages, and opposes artificially created “villages” in cities. In so doing, alternative readings of rurality and villages by Rem Koolhaas, Brazilian land reformers, Mahatma Gandhi, and critics of contemporary Indian literature and urbanism are considered

    A rhetoric-in-context approach to building commitment to multiple strategic goals

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    There are still few explanations of the micro-level practices by which top managers influence employee commitment to multiple strategic goals. This paper argues that, through their language, top managers can construct a context for commitment to multiple strategic goals. We therefore propose a rhetoric-in-context approach to illuminate some of the micro practices through which top managers influence employee commitment. Based upon an empirical study of the rhetorical practices through which top managers influence academic commitment to multiple strategic goals in university contexts, we demonstrate relationships between rhetoric and context. Specifically, we show that rhetorical influences over commitment to multiple goals are associated with the historical context for multiple goals, the degree to which top managers' rhetoric instantiates a change in that context, and the internal consistency of the rhetorical practices used by top managers. Copyright © 2007 SAGE Publications

    New factors for protein transport identified by a genome-wide CRISPRi screen in mammalian cells

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    Protein and membrane trafficking pathways are critical for cell and tissue homeostasis. Traditional genetic and biochemical approaches have shed light on basic principles underlying these processes. However, the list of factors required for secretory pathway function remains incomplete, and mechanisms involved in their adaptation poorly understood. Here, we present a powerful strategy based on a pooled genome-wide CRISPRi screen that allowed the identification of new factors involved in protein transport. Two newly identified factors, TTC17 and CCDC157, localized along the secretory pathway and were found to interact with resident proteins of ER-Golgi membranes. In addition, we uncovered that upon TTC17 knockdown, the polarized organization of Golgi cisternae was altered, creating glycosylation defects, and that CCDC157 is an important factor for the fusion of transport carriers to Golgi membranes. In conclusion, our work identified and characterized new actors in the mechanisms of protein transport and secretion, and opens stimulating perspectives for the use of our platform in physiological and pathological contexts.Includes Wellcome Trust, MRC and H202

    Gathering Global Perspectives to Establish the Research Priorities and Minimum Data Sets for Degenerative Cervical Myelopathy:Sampling Strategy of the First Round Consensus Surveys of AO Spine RECODE-DCM

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    STUDY DESIGN: Survey.INTRODUCTION: AO Spine Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy (AO Spine RECODE-DCM) is an international initiative that aims to accelerate knowledge discovery and improve outcomes by developing a consensus framework for research. This includes defining the top research priorities, an index term and a minimum data set (core outcome set and core data elements set - core outcome set (COS)/core data elements (CDE)).OBJECTIVE: To describe how perspectives were gathered and report the detailed sampling characteristics.METHODS: A two-stage, electronic survey was used to gather and seek initial consensus. Perspectives were sought from spinal surgeons, other healthcare professionals and people with degenerative cervical myelopathy (DCM). Participants were allocated to one of two parallel streams: (1) priority setting or (2) minimum dataset. An email campaign was developed to advertise the survey to relevant global stakeholder individuals and organisations. People with DCM were recruited using the international DCM charity Myelopathy.org and its social media channels. A network of global partners was recruited to act as project ambassadors. Data from Google Analytics, MailChimp and Calibrum helped optimise survey dissemination.RESULTS: Survey engagement was high amongst the three stakeholder groups: 208 people with DCM, 389 spinal surgeons and 157 other healthcare professionals. Individuals from 76 different countries participated; the United States, United Kingdom and Canada were the most common countries of participants.CONCLUSION: AO Spine RECODE-DCM recruited a diverse and sufficient number of participants for an international PSP and COS/CDE process. Whilst PSP and COS/CDE have been undertaken in other fields, to our knowledge, this is the first time they have been combined in one process.</p
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