5,715 research outputs found

    ‘The uses of ethnography in the science of cultural evolution’. Commentary on Mesoudi, A., Whiten, A. and K. Laland ‘Toward a unified science of cultural evolution’

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    There is considerable scope for developing a more explicit role for ethnography within the research program proposed in the article. Ethnographic studies of cultural micro-evolution would complement experimental approaches by providing insights into the “natural” settings in which cultural behaviours occur. Ethnography can also contribute to the study of cultural macro-evolution by shedding light on the conditions that generate and maintain cultural lineages

    Did Einstein Really Say that? Testing Content Versus Context in the Cultural Selection of Quotations

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    We experimentally investigated the influence of context-based biases, such as prestige and popularity, on the preferences for quotations. Participants were presented with random quotes associated to famous or unknown authors (experiment one), or with random quotes presented as popular, i.e. chosen by many previous participants, or unpopular (experiment two). To exclude effects related to the content of the quotations, all participants were subsequently presented with the same quotations, again associated to famous and unknown authors (experiment three), or presented as popular or unpopular (experiment four). Overall, our results showed that context-based biases had no (in case of prestige and conformity), or limited (in case of popularity), effect in determining participants’ choices. Quotations preferred for their content were preferred in general, despite the contextual cues to which they were associated. We conclude discussing how our results fit with the well-known phenomenon of the spread and success (especially digital) of misattributed quotations, and we draw some more general implications for cultural evolution research

    Chicken tumours and fishy revenge: Evidence for emotional content bias in the cumulative recall of urban legends

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    This study used urban legends to examine the effects of a cognitive bias for content which evokes higher levels of emotion on cumulative recall. As with previous research into content biases, a linear transmission chain design was used. One-hundred and twenty participants, aged 16–52, were asked to read and then recall urban legends that provoked both high levels and low levels of emotion and were both positively and negatively valenced. The product of this recall was presented to the next participant in a chain of three generations. A significant effect of emotion level on transmission fidelity was found with high emotion legends being recalled with significantly greater accuracy than low emotion legends. The emotional valence of a legend was found not to have any effect on cumulative recall; thus emotional biases in recall go beyond disgust and can incorporate other emotions such as amusement, interest and surprise. This study is the first to examine an emotion bias in cultural transmission as a general phenomenon without focusing on the emotion of disgust

    Brief trauma therapy for occupational trauma-related PTSD/CPTSD in UK police

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    BACKGROUND: Police are frequently exposed to occupational trauma, making them vulnerable to post-traumatic stress disorder (PTSD) and other mental health conditions. Through personal and occupational trauma police are also at risk of developing Complex PTSD (CPTSD), associated with prolonged and repetitive trauma. Police Occupational Health Services require effective interventions to treat officers experiencing mental health conditions, including CPTSD. However, there is a lack of guidance for the treatment of occupational trauma. AIMS: To explore differences in demographics and trauma exposure between police with CPTSD and PTSD and compare the effectiveness of brief trauma-focused therapy between these diagnostic groups. METHODS: Observational cohort study using clinical data from the Trauma Support Service, providing brief trauma-focused therapy for PTSD (cognitive behavioural therapy/eye movement desensitization and reprocessing) to UK police officers. Demographics, trauma exposure, baseline symptom severity and treatment effectiveness were compared between police with PTSD and CPTSD. Changes in PTSD, depression and anxiety symptoms were used to measure treatment effectiveness. RESULTS: Brief trauma therapy reduced symptoms of PTSD, depression and anxiety. Treatment effectiveness did not differ between CPTSD and PTSD groups. Police with CPTSD exposed to both primary and secondary occupational trauma had poorer treatment outcomes than those exposed to a single occupational trauma type. CONCLUSIONS: Brief trauma-focused interventions are potentially effective in reducing symptoms of PTSD, depression and anxiety in police with CPTSD and PTSD. Further research is needed to establish whether additional CPTSD symptoms (affect dysregulation, self-perception and relational difficulties) are also reduced

    The NNLO non-singlet QCD analysis of parton distributions based on Bernstein polynomials

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    A non-singlet QCD analysis of the structure function xF3xF_3 up to NNLO is performed based on the Bernstein polynomials approach. We use recently calculated NNLO anomalous dimension coefficients for the moments of the xF3xF_3 structure function in νN\nu N scattering. In the fitting procedure, Bernstein polynomial method is used to construct experimental moments from the xF3xF_3 data of the CCFR collaboration in the region of xx which is inaccessible experimentally. We also consider Bernstein averages to obtain some unknown parameters which exist in the valence quark densities in a wide range of xx and Q2Q^2. The results of valence quark distributions up to NNLO are in good agreement with the available theoretical models. In the analysis we determined the QCD-scale ΛQCD,Nf=4MSˉ=211\Lambda^ {\bar{MS}}_{QCD, N_{f}=4}=211 MeV (LO), 259 MeV (NLO) and 230 MeV (NNLO), corresponding to αs(MZ2)=0.1291\alpha_s(M_Z^2)=0.1291 LO, αs(MZ2)=0.1150\alpha_s(M_Z^2)=0.1150 NLO and αs(MZ2)=0.1142\alpha_s(M_Z^2)=0.1142 NNLO. We compare our results for the QCD scale and the αs(MZ2)\alpha_s(M_Z^2) with those obtained from deep inelastic scattering processes.Comment: 20 pages, 7 figures, published in JHE

    Transputer modelling of ventricular dysrhythmia

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    Risk factors for complex posttraumatic stress disorder in UK police

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    Background: Police officers are frequently exposed to distressing and dangerous situations, increasing their risk of posttraumatic stress disorder (PTSD) and complex PTSD (C-PTSD). Research examining C-PTSD in police officers is sparse, particularly examination of the occupational risk factors for trauma symptoms. Aims: This study aimed to examine the prevalence and risk factors for PTSD and C-PTSD in UK police officers. Methods: A cross-sectional study was conducted using psychological health surveillance data from the UK National Police Wellbeing Service. Police officers were either from high-risk areas of work or had been referred for screening by occupational health practitioners regarding psychological distress. The primary outcome for this study was a positive screening of either PTSD or C-PTSD, measured using the International Trauma Questionnaire. A range of occupational, clinical and lifestyle factors was examined to establish their role as potential risk factors for PTSD and C-PTSD. Results: In total, 2444 UK police officers were included, with 89% from high-risk areas of work. A prevalence of 3% for PTSD and 2% for C-PTSD was found in police officers from high-risk areas of work. Higher work stress and lower manager support were found to increase the odds of C-PTSD but not PTSD. Higher personal trauma history increased the risk for PTSD and C-PTSD equally. Conclusions: Work-related occupational factors increased the odds of PTSD and C-PTSD in police officers, which could be important risk factors for trauma symptoms within police officers. Efforts should be made to improve the working environment of police officers to help improve their psychological well-being

    Exapting exaptation

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    The term exaptation was introduced to encourage biologists to consider alternatives to adaptation to explain the origins of traits. Here, we discuss why exaptation has proved more successful in technological than biological contexts, and propose a revised definition of exaptation applicable to both genetic and cultural evolution

    Modelling of an Oesophageal Electrode for Cardiac Function Tomography

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    There is a need in critical care units for continuous cardiopulmonary monitoring techniques. ECG gated electrical impedance tomography is able to localize the impedance variations occurring during the cardiac cycle. This method is a safe, inexpensive and potentially fast technique for cardiac output imaging but the spatial resolution is presently low, particularly for central locations such as the heart. Many parameters including noise deteriorate the reconstruction result. One of the main obstacles in cardiac imaging at the heart location is the high impedance of lungs and muscles on the dorsal and posterior side of body. In this study we are investigating improvements of the measurement and initial conductivity estimation of the internal electrode by modelling an internal electrode inside the esophagus. We consider 16 electrodes connected around a cylindrical mesh. With the random noise level set near 0.05% of the signal we evaluated the Graz consensus reconstruction algorithm for electrical impedance tomography. The modelling and simulation results showed that the quality of the target in reconstructed images was improved by up to 5 times for amplitude response, position error, resolution, shape deformation and ringing effects with perturbations located in cardiac related positions when using an internal electrode
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