932 research outputs found

    Some aspects of Jansenism

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    Respiratory challenge MRI: practical aspects

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    Respiratory challenge MRI is the modification of arterial oxygen (PaO2) and/or carbon dioxide (PaCO2) concentration to induce a change in cerebral function or metabolism which is then measured by MRI. Alterations in arterial gas concentrations can lead to profound changes in cerebral haemodynamics which can be studied using a variety of MRI sequences. Whilst such experiments may provide a wealth of information, conducting them can be complex and challenging. In this paper we review the rationale for respiratory challenge MRI including the effects of oxygen and carbon dioxide on the cerebral circulation. We also discuss the planning, equipment, monitoring and techniques that have been used to undertake these experiments. We finally propose some recommendations in this evolving area for conducting these experiments to enhance data quality and comparison between techniques

    The effects of a graduated aerobic exercise programme on cardiovascular disease risk factors in the NHS workplace: a randomised controlled trial

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    BACKGROUND: Sufficient levels of physical activity provide cardio-protective benefit. However within developed society sedentary work and inflexible working hours promotes physical inactivity. Consequently to ensure a healthy workforce there is a requirement for exercise strategies adaptable to occupational time constraint. This study examined the effect of a 12 week aerobic exercise training intervention programme implemented during working hours on the cardiovascular profile of a sedentary hospital workforce. METHODS: Twenty healthy, sedentary full-time staff members of the North West London Hospital Trust cytology unit were randomly assigned to an exercise (n = 12; mean +/- SD age 41 +/- 8 years, body mass 69 +/- 12 kg) or control (n = 8; mean +/- SD age 42 +/- 8 years, body mass 69 +/- 12 kg) group. The exercise group was prescribed a progressive aerobic exercise-training programme to be performed 4 times a week for 8 weeks (initial intensity 65% peak oxygen consumption (VO2 peak)) and to be conducted without further advice for another 4 weeks. The control was instructed to maintain their current physical activity level. Oxygen economy at 2 minutes (2minVO2), 4 minutes (4minVO2), VO2 peak, systolic blood pressure (SBP), diastolic blood pressure (DBP), BMI, C-reactive protein (CRP), fasting glucose (GLU) and total cholesterol (TC) were determined in both groups pre-intervention and at 4 week intervals. Both groups completed a weekly Leisure Time Questionnaire to quantify additional exercise load. RESULTS: The exercise group demonstrated an increase from baseline for VO2 peak at week 4 (5.8 +/- 6.3 %) and 8 (5.0 +/- 8.7 %) (P < 0.05). 2minVO2 was reduced from baseline at week 4 (-10.2 +/- 10.3 %), 8 (-16.8 +/- 10.6 %) and 12 (-15.1 +/- 8.7 %), and 4minVO2 at week 8 (-10.7 +/- 7.9 %) and 12 (-6.8 +/- 9.2) (P < 0.05). There was also a reduction from baseline in CRP at week 4 (-0.4 +/- 0.6 mg.L-1) and 8 (-0.9 +/- 0.8 mg.L-1) (P < 0.05). The control group showed no such improvements. CONCLUSION: This is the first objectively monitored RCT to show that moderate exercise can be successfully incorporated into working hours, to significantly improve physical capacity and cardiovascular health

    Conserving nature out of fear or knowledge? Using threatening versus connecting messages to generate support for environmental causes

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    Threatening and connecting messages are two types of appeals commonly used to encourage conservation behaviors, yet little research has examined their psychological impacts and behavioral outcomes. This paper describes two studies contrasting these approaches with a neutral comparison and testing their effects on state levels of negative affect, caring, and openness, psychological states which we expected in turn would encourage conservation behavior. Participants viewed visually identical nature videos with no text, connecting text or negative text. They then reported on their state experiences, and were asked to engage in conservation behaviors, including supporting conservation organizations. Findings showed that connecting messages increased caring and openness, and decreased negative affect, and by doing so elicited more conservation behaviors. On the other hand, threatening messages showed no beneficial effects above a neutral comparison without an appeal. Our findings, which we contextualize in motivational theory, can be used to inform the use of messages to promote conservation.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jnc.2015.04.00

    Reliability and responsiveness of measures of pain in people with osteoarthritis of the knee: a psychometric evaluation

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    PURPOSE: To examine the fit between data from the Short Form McGill Pain Questionnaire (SF-MPQ-2) and the Rasch model, and to explore the reliability and internal responsiveness of measures of pain in people with knee osteoarthritis. METHODS: Participants with knee osteoarthritis completed the SF-MPQ-2, Intermittent and Constant Osteoarthritis Pain questionnaire (ICOAP) and painDETECT. Participants were sent the same questionnaires 3 and 6 months later. RESULTS: Fit to the Rasch model was not achieved for the SF-MPQ-2 Total scale. The Continuous subscale yielded adequate fit statistics after splitting item 10 on uniform DIF for gender, and removing item 9. The Intermittent subscale fit the Rasch model after rescoring items. The Neuropathic subscale had relatively good fit to the model. Test-retest reliability was satisfactory for most scales using both original and Rasch scoring ranging from fair to substantial. Effect sizes ranged from 0.13 to 1.79 indicating good internal responsiveness for most scales. CONCLUSIONS: These findings support the use of ICOAP subscales as reliable and responsive measure of pain in people with knee osteoarthritis. The MPQ-SF-2 subscales found to be acceptable alternatives. Implications for Rehabilitation The McGill Pain Questionnaire short version 2 is not a unidimensional scale in people with knee osteoarthritis, whereas three of the subscales are unidimensional. The McGill Pain Questionnaire short version 2 Affective subscale does not have good measurement properties for people with knee osteoarthritis. The McGill Pain Questionnaire short version 2 and the Intermittent and Constant Osteoarthritis Pain scales can be used to assess change over time. The painDETECT performs better as a screening measure than as an outcome measure

    Do professional facial image comparison training courses work?

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    Facial image comparison practitioners compare images of unfamiliar faces and decide whether or not they show the same person. Given the importance of these decisions for national security and criminal investigations, practitioners attend training courses to improve their face identification ability. However, these courses have not been empirically validated so it is unknown if they improve accuracy. Here, we review the content of eleven professional training courses offered to staff at national security, police, intelligence, passport issuance, immigration and border control agencies around the world. All reviewed courses include basic training in facial anatomy and prescribe facial feature (or 'morphological') comparison. Next, we evaluate the effectiveness of four representative courses by comparing face identification accuracy before and after training in novices (n = 152) and practitioners (n = 236). We find very strong evidence that short (1-hour and half-day) professional training courses do not improve identification accuracy, despite 93% of trainees believing their performance had improved. We find some evidence of improvement in a 3-day training course designed to introduce trainees to the unique feature-by-feature comparison strategy used by facial examiners in forensic settings. However, observed improvements are small, inconsistent across tests, and training did not produce the qualitative changes associated with examiners' expertise. Future research should test the benefits of longer examination-focussed training courses and incorporate longitudinal approaches to track improvements caused by mentoring and deliberate practice. In the absence of evidence that training is effective, we advise agencies to explore alternative evidence-based strategies for improving the accuracy of face identification decisions

    E-AI : an emotion architecture for agents in games & virtual worlds

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    Characters in games and virtual worlds continue to gain improvements in both their visual appearance and more human-like behaviours with each successive generation of hardware. One area that seemingly would need to be addressed if this evolution in human-like characters is to continue is in the area of characters with emotions. To begin addressing this, the thesis focuses on answering the question “Can an emotional architecture be developed for characters in games and virtual worlds, that is built upon a foundation of formal psychology? Therefore a primary goal of the research was to both review and consolidate a range of background material based on the psychology of emotions to provide a cohesive foundation on which to base any subsequent work. Once this review was completed, a range of supplemental material was investigated including computational models of emotions, current implementations of emotions in games and virtual worlds, machine learning techniques suitable for implementing aspects of emotions in characters in virtual world, believability and the role of emotions, and finally a discussion of interactive characters in the form of chat bots and non-player characters. With these reviews completed, a synthesis of the research resulted in the defining of an emotion architecture for use with pre-existing agent behaviour systems, and a range of evaluation techniques applicable to agents with emotions. To support validation of the proposed architecture three case studies were conducted that involved applying the architecture to three very different software platforms featuring agents. The first was applying the architecture to combat bots in Quake 3, the second to a chat bot in the virtual world Second Life, and the third was to a web chat bot used for e-commerce, specifically dealing with question and answers about the companies services. The three case studies were supported with several small pilot evaluations that were intended to look at different aspects of the implemented architecture including; (1) Whether or not users noticed the emotional enhancements. Which in the two small pilot studies conducted, highlighted that the addition of emotions to characters seemed to affect the user experience when the encounter was more interactive such as in the Second Life implementation. Where the interaction occurred in a combat situation with enemies with short life spans, the user experience seemed to be greatly reduced. (2) An evaluation was conducted on how the combat effectiveness of combat bots was affected by the addition of emotions, and in this pilot study it was found that the combat effectiveness was not quite statistically reduced, even when the bots were running away when afraid, or attacking when angry even if close to death. In summary, an architecture grounded in formal psychology is presented that is suitable for interactive characters in games and virtual worlds, but not perhaps ideal for applications where user interaction is brief such as in fast paced combat situations. This architecture has been partially validated through three case studies and includes suggestions for further work especially in the mapping of secondary emotions, the emotional significance of conversations, and the need to conduct further evaluations based on the pilot studies.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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