634 research outputs found

    Social rank overrides environmental and community fluctuations in determining meat access by female chimpanzees in the Taï National Park, Côte d’Ivoire

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    Meat, long hypothesized as an important food source in human evolution, is still a substantial component of the modern human diet, with some humans relying entirely on meat during certain times of the year. Understanding the socio-ecological context leading to the successful acquisition and consumption of meat by chimpanzees (Pan troglodytes), our closest living relative, can provide insight into the emergence of this trait because humans and chimpanzees are unusual among primates in that they both (i) hunt mammalian prey, (ii) share meat with community members, and (iii) form long-term relationships and complex social hierarchies within their communities. However, females in both human hunter-gatherer societies as well as chimpanzee groups rarely hunt, instead typically accessing meat via males that share meat with group members. In general, female chimpanzee dominance rank affects feeding competition, but so far, the effect of female dominance rank on meat access found different results within and across studied chimpanzee groups. Here we contribute to the debate on how female rank influences meat access while controlling for several socio-ecological variables. Multivariate analyses of 773 separate meat-eating events collected over more than 25 years from two chimpanzee communities located in the Taï National Park, Côte d’Ivoire, were used to test the importance of female dominance rank for being present at, and for acquiring meat, during meat-eating events. We found that high-ranking females were more likely to be present during a meat-eating event and, in addition, were more likely to eat meat compared to the subordinates. These findings were robust to both large demographic changes (decrease of community size) and seasonal ecological changes (fruit abundance dynamics). In addition to social rank, we found that other female properties had a positive influence on presence to meat-eating events and access to meat given presence, including oestrus status, nursing of a small infant, and age. Similar to findings in other chimpanzee populations, our results suggest that females reliably acquire meat over their lifetime despite rarely being active hunters. The implication of this study supports the hypothesis that dominance rank is an important female chimpanzee property conferring benefits for the high-ranking females

    Annular flow pattern recognition using statistical data analyses of Electrical Impedance Tomography

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    Collecting very large amount of data from experimental multiphase measurement is a common practice in almost every scientific domain. There is a great need to have specific techniques capable of extracting synthetic information, which is essential to understand and model the specific flow phenomena. The intention of developing a method for recognition of flow regime using decomposition mathematical technique comes from the fact that each regime is characterised by typical dynamic behaviour. To recognise the flow dynamic structures, means indeed the recognition of the prevalent regime moreover indicates the actual flow conditions of the monitored area. The direct approach of Proper Orthogonal Decomposition (POD) as introduced by Lumley and the Linear Stochastic Estimation (LSE) as introduced by Adrian are used to identify typical multiphase flow instability. The present approach of statistical data-analysis extends the current evaluation procedure of Electrical Impedance Tomography (EIT) applied on air-water flow measurement. Wavelet Transformation and Kalman Filtering was used as complementary techniques for motion of fluid and flow structures detection and decomposed EIT signal similarity estimation. The paper demonstrates the capability of EIT measurement techniques combined with POD/LSE post-processing for studying annular flow patterns in vertical and horizontal pipeline

    Numerical modelling of gas-liquid flow phenomena in horizontal pipelines

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    Gas-liquid flows are omnipresent in industrial and environmental processes. Examples are the transportation of petroleum products [1, 2], the cooling of nuclear reactors [3, 4], the operation of absorbers [5], distillation columns [6], gas lift pumps [7] and many mores. Different input parameters induce topologically different flow patterns with different flow character and behaviour [7, 8] . The present study concentrate to diabatic incompressible two-phase flow in horizontal pipeline with separated character [9, 10] (Ugas < 10m/s and Uliquid < 0:2m/s) such as stratified wavy flow regime including typical multiphase instability (Kelvin-elmholtz instability) [11, 12]. The Proper Orthogonal Decomposition (POD) [13], introduced by Lumpay (1967) [14] was used to extract synthetic information essential to understand and to model flow dynamics phenomena. POD in this study are used to identify flow structure in the horizontal pipeline specially under transient of separated flow regimes. The snapshot matrix are reconstruct for specific flow sections and regimes. Present decomposition method, in this case used to analyse CFD data, are originally testing and developing for future using to analyse experimental data obtained by process tomography system [15]

    Proper Orthogonal Decomposition as a technique for identifying multiphase flow regime based on Electrical Impedance Tomography

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    Collecting very large amount of data from experimental measurement is a common practice in almost every scientific domain. There is a great need to have specific techniques capable of extracting synthetic information, which is essential to understand and model the specific phenomena. The Proper Orthogonal Decomposition (POD) is one of the most powerful data-analysis methods for multivariate and nonlinear phenomena. Generally, POD is a procedure that takes a given collection of input experimental or numerical data and creates an orthogonal basis constituted by functions estimated as the solutions of an integral eigenvalue problem known as a Fredholm equation. By utilising POD to identify flow structure in horizontal pipeline, specially, for slag, plug and wavy stratified air-water flow regimes, this paper proposes a novel approach, in which POD technique extends the current evaluation procedure of Electrical Impedance Tomography applied on air-water flow measurement. This extension is provided by implementation of the POD as an identifier of typical horizontal multiphase flow regimes. The POD snapshot matrices are reconstructed for EIT measurement domain and specific flow conditions. Direct POD method introduced by Lumley is applied. It is expected that this study may provide new knowledge on two phase flow dynamics in a horizontal pipeline and supportive information for further prediction of multiphase flow regime

    Exposure to smoking in movies among British adolescents 2001–2006

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    ObjectiveTo estimate youth exposure to smoking in movies in the UK and compare the likely effect with the USA.MethodsWe collected tobacco occurrences data for 572 top-grossing films in the UK screened from 2001 to 2006 and estimated the number of on-screen tobacco impressions delivered to British youths in this time period.Results91% of films in our sample that contained smoking were youth-rated films (British Board of Film Classification rating '15' and lower), delivering at least 1.10 billion tobacco impressions to British youths during theatrical release. British youths were exposed to 28% more smoking impressions in UK youth-rated movies than American youth-rated movies, because 79% of movies rated for adults in the USA ('R') are classified as suitable for youths in the UK ('15' or '12A').ConclusionBecause there is a dose-response relation between the amount of on-screen exposure to smoking and the likelihood that adolescents will begin smoking, the fact that there is substantially higher exposure to smoking in youth-rated films in the UK than in the USA suggests that the fraction of all youth smoking because of films in the UK is probably larger than in the USA. Other countries with ratings systems that are less conservative (in terms of language and sexuality) than the USA will also be likely to deliver more on-screen tobacco impressions to youths. Assigning an '18' classification to movies that contain smoking would substantially reduce youth exposure to on-screen smoking and, hence, smoking initiation among British youths

    Study and comparison of results of experimental and numerical solutions for hydraulic analogy

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    Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.The hydraulic analogy existing between the propagation of wavelets at the free surface flow of a liquid and the propagation of acoustic waves in a compressible gas is used to study aerodynamics problems with phenomena at flow around solids at supersonic velocities and aeroacoustic phenomena in supersonic divergent jets. In particular, water level fluctuations, which are proportional to pressure fluctuations in the gas, are measured with an optical fiber and special measuring apparatus. Investigations are carried out on a convergent-divergent (de Laval) nozzle. This phenomenon is linked to the existence of shock-cells in supersonic jets, which are formed in the output of the nozzle. These experimental results will be compared with the results from numerical solution and will be obtained from our own program and from the commercial program CFD Fluent.cs201

    Experimental Evaluation of Dual-Modality Electrical Tomographic Systems on Gas-Oil-Water Flow in Horizontal Pipeline

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    A variety of dual-modality tomographic systems have been proposed for the characterisation of multiphase flow, but the evaluation of such systems are generally carried out under simplified flow conditions, such as stratified flow and slug flow. This paper reports the evaluation results of a dualmodality electrical tomographic system in an industry-scale gas-oil-water three-phase flow. Experimental conditions include water-to-liquid ratio (WLR) from 0% to 100% in parallel with gas volume fractions from 0% to 100%, which produces a variety of flow patterns, such as stratified-wavy flow, slug flow, plug flow, bubbly flow, and annular flow. Commercialised ITS M3C (ECT) and V5R (ERT) dual-modality systems were applied to perform the measurement. A threshold-based multidimensional data fused approach was implemented for the data fusion process. The results demonstrated that the ERT system is able to measure water continuous flow with WLR higher than 40%, which is in good agreement with previous reports. The ECT system is able to measure from 0% to 100% WLR, far beyond its conventional capabilities. Even though the tomograms are distorted when WLR is higher than 90%, this result is much better than the reported 40% limit. Visualisation and mean concentration derived from the tomograms by advanced data fusion verify the capability of the system in the application of gas-oil-water flow characterisation

    The Causal Structure of Emotions in Aristotle: Hylomorphism, Causal Interaction between Mind and Body, and Intentionality

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    Recently, a strong hylomorphic reading of Aristotelian emotions has been put forward, one that allegedly eliminates the problem of causal interaction between soul and body. Taking the presentation of emotions in de An. I 1 as a starting point and basic thread, but relying also on the discussion of Rh. II, I will argue that this reading only takes into account two of the four causes of emotions, and that, if all four of them are included into the picture, then a causal interaction of mind and body remains within Aristotelian emotions, independent of how strongly their hylomorphism is understood. Beyond the discussion with this recent reading, the analysis proposed of the fourfold causal structure of emotions is also intended as a hermeneutical starting point for a comprehensive analysis of particular emotions in Aristotle. Through the different causes Aristotle seems to account for many aspects of the complex phenomenon of emotion, including its physiological causes, its mental causes, and its intentional object
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