987 resultados para Choice behaviour


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This work has been presented in: V Conference AERNA, Faro (Portugal), 30 May 2012-1 June 2012 and IV Workshop on Valuation Methods in Agro-food and Environmental Economics, Castelldefels (Barcelona, Spain), 12 July 2012-13 July 2012.

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Theories of instrumental learning are centred on understanding how success and failure are used to improve future decisions. These theories highlight a central role for reward prediction errors in updating the values associated with available actions. In animals, substantial evidence indicates that the neurotransmitter dopamine might have a key function in this type of learning, through its ability to modulate cortico-striatal synaptic efficacy. However, no direct evidence links dopamine, striatal activity and behavioural choice in humans. Here we show that, during instrumental learning, the magnitude of reward prediction error expressed in the striatum is modulated by the administration of drugs enhancing (3,4-dihydroxy-L-phenylalanine; L-DOPA) or reducing (haloperidol) dopaminergic function. Accordingly, subjects treated with L-DOPA have a greater propensity to choose the most rewarding action relative to subjects treated with haloperidol. Furthermore, incorporating the magnitude of the prediction errors into a standard action-value learning algorithm accurately reproduced subjects' behavioural choices under the different drug conditions. We conclude that dopamine-dependent modulation of striatal activity can account for how the human brain uses reward prediction errors to improve future decisions.

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Marnet, Oliver, 'History repeats itself: The failure of rational choice models in corporate governance', Critical Perspectives on Accounting (2005) 18(2) pp.191-210 RAE2008

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This paper presents data relating to pedestrian escalator behaviour collected in an underground station in Shanghai, China. While data was not collected under emergency or simulated emergency conditions, it is argued that the data collected under rush-hour conditions - where commuters are under time pressures to get to work on time - may be used to approximate emergency evacuation conditions - where commuters are also under time pressures to exit the building as quickly as possible. Data pertaining to escalator/stair choice, proportion of walkers to riders, walker speeds and side usage are presented. The collected data is used to refine the buildingEXODUS escalator model allowing the agents to select whether to use an escalator or neighbouring parallel stair based on congestion conditiions at the base of the stair/escalator and expected travel times. The new model, together with the collected data, is used to simulate a series of hypothetical evacuation scenarios to demonstrate the impact of escalators on evacuation performance.

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This paper presents an escalator model for use in circulation and evacuation analysis. As part of the model development, human factors data was collected from a Spanish underground station. The collected data relates to: escalator/stair choice, rider/walker preference, rider side preference, walker travel speeds and escalator flow rates. The dataset provides insight into pedestrian behaviour in utilising escalators and is a useful resource for both circulation and evacuation models. Based on insight derived from the dataset a detailed microscopic escalator model which incorporates person-person interactions has been developed. A range of demonstration evacuation scenarios are presented using the newly developed microscopic escalator model.

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Although the theory of planned behaviour (TPB) has been applied successfully in the area of food choice, it has been criticized for its pure utilitarian approach to the factors determining behaviour. Despite the increase in predictive power of the model with added components such as affective attitude and moral and ethical concerns, in most studies the elicitation process still only addresses people's utilitarian beliefs about the behaviour with little attention paid to other aspects. This study compares the traditional method of elicitation of advantages and disadvantages with two other methods (word association and open-ended) in the elicitations of beliefs, attitudes and moral concerns in relation to the consumption of organic foods. Results show the traditional method to be best for eliciting cognitive beliefs, open-ended emotion task for eliciting emotional beliefs and open-ended beliefs task best for moral concerns. The advantages and disadvantages of each method are discussed.

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Sexual cannibalism, where a female kills and consumes a courting male, represents an extreme form of sexual conflict and has been proposed as a mechanism of mate choice. We evaluate the evidence for mate choice through premating sexual cannibalism via mate rejection, other indirect mechanisms of mate 'choice' and choice in postmating sexual cannibalism. We highlight a paucity of investigations, particularly of field studies, and note gaps in our knowledge. There is empirical support for the size-dependent sexual cannibalism predicted by mate choice through premating sexual cannibalism. This may represent mate choice operating on absolute male size but it could be a by-product of female foraging behaviour and greater vulnerability of relatively smaller males. Thus, indirect mate choice is as plausible an explanation of size-dependent sexual cannibalism as is direct mate choice based on discrimination of male traits. Direct female choice, mediated through premating sexual cannibalism, has yet to be demonstrated. We suggest a framework for distinguishing direct and indirect choice and note an absence of information on which to test it. There is evidence for sequential mate choice in postmating sexual cannibalism, but the nature or basis of the female's discriminatory behaviour remains unclear. Costs and long-term fitness benefits of the putative mate choice have been largely ignored. Reversed sexual cannibalism, in which the male eats the female, presumably occurs when the gain from food is high and potential gain from mating low and probably has little to do with mate choice. (c) 2005 The Association for the Study of Animal Behaviour Published by Elsevier Ltd. All rights reserved.

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1. Mounting an immune response is likely to be costly in terms of energy and nutrients, and so it is predicted that dietary intake should change in response to infection to offset these costs. The present study focuses on the interactions between a specialist grass-feeding caterpillar species, the African armyworm Spodoptera exempta, and an opportunist bacterium, Bacillus subtilis.
2. The main aims of the study were (i) to establish the macronutrient costs to the insect host of surviving a systemic bacterial infection, (ii) to determine the relative importance of dietary protein and carbohydrate to immune system functions, and (iii) to determine whether there is an adaptive change in the host's normal feeding behaviour in response to bacterial challenge, such that the nutritional costs of resisting infection are offset.
3. We show that the survival of bacterially infected larvae increased with increasing dietary protein-to-carbohydrate (P:C) ratio, suggesting a protein cost associated with bacterial resistance. As dietary protein levels increased, there was an increase in antibacterial activity, phenoloxidase (PO) activity and protein levels in the haemolymph, providing a potential source for this protein cost. However, there was also evidence for a physiological trade-off between antibacterial activity and phenoloxidase activity, as larvae whose antibacterial activity levels were elevated in response to immune activation had reduced PO activity.
4. When given a choice between two diets varying in their P:C ratios, larvae injected with a sub-lethal dose of bacteria increased their protein intake relative to control larvae whilst maintaining similar carbohydrate intake levels. These results are consistent with the notion that S. exempta larvae alter their feeding behaviour in response to bacterial infection in a manner that is likely to enhance the levels of protein available for producing the immune system components and other factors required to resist bacterial infections (‘self-medication’).

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Background The provision of training for foster carers is now seen as an important factor contributing to the successful outcome of foster care placements. Since the late 1960s, foster carer training programs have proliferated, and few of the many published and unpublished training curricula have been systematically evaluated. The advent of cognitive-behavioural therapy (CBT) and the research evidence demonstrating its effectiveness as a psychotherapeutic treatment of choice for a range of emotional and behavioural problems, has prompted the development of CBT-based training programmes. CBT approaches to foster care training derive from a ’skill-based’ training format that also seeks to identify and correct problematic thinking patterns that are associated with dysfunctional behaviour by changing and/or challenging maladaptive thoughts and beliefs. Objectives To assess the effectiveness of cognitive-behavioural training interventions in improving a) looked-after children’s behavioural/relationship problems, b) foster carers’ psychological well-being and functioning, c) foster family functioning, d) foster agency outcomes. Search methods We searched databases including: CENTRAL (Cochrane Library Issue 3, 2006), MEDLINE (January 1966 to September 2006), EMBASE (January 1980 to September 2006), CINAHL (January 1982 to September 2006), PsycINFO (January 1872 to September 2006), ASSIA (January 1987 to September 2006), LILACS (up to September 2006), ERIC (January 1965 to September 2006), Sociological Abstracts (January 1963 to September 2006), and the National Research Register 2006 (Issue 3).We contacted experts in the field concerning current research. Selection criteria Random or quasi randomised studies comparing behavioural or cognitive-behavioural-base Data collection and analysis Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. Main results Six trials involving 463 foster carers were included. Behavioural and cognitive-behavioural training interventions evaluated to date appear to have very little effect on outcomes relating to looked-after children, assessed in relation to psychological functioning, extent of behavioural problems and interpersonal functioning. Results relating to foster carer(s) outcomes also show no evidence of effectiveness in measures of behavioural management skills, attitudes and psychological functioning. Analysis pertaining to fostering agency outcomes did not show any significant results. However, caution is needed in interpreting these findings as their confidence intervals are wide. Authors’ conclusions There is currently little evidence about the efficacy of behavioural or cognitive-behavioural training intervention for foster carers. The need for further research in this area is highlighted.

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Using rewards may be an effective method to positively influence adolescent eating behaviour, but evidence regarding this approach is limited. The aim of this study was to explore young adolescent views about a proposed reward intervention associated with food choice in school canteens. Focus groups were held in 10 schools located in lower socioeconomic areas within Northern Ireland and involved 90 pupils aged 11-12 years (54 girls, 36 boys). Our findings indicated a high degree of acceptability for a reward scheme but there was major diversity in the type of rewards valued by pupils, largely defined by geographical area and socio-cultural differences. Pupils from rural areas tended to emphasize group-based and longer-term rewards, whereas pupils from urban-city schools tended to suggest individualistic and immediate rewards. The major factors influencing food choice were food price, value for money, taste and visual appearance. Pupils felt that factors outside of their control, such as being assigned to the second lunch sitting placed considerable constraints on their food choice. This research not only indicated a high degree of acceptability for a rewards-based intervention but also highlighted a number of socio-cultural and environmental factors that should be considered by researchers when developing such an intervention.

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Consociational institutional arrangements in deeply divided societies are often criticised for cementing the underlying conflict cleavage, encouraging the continued dominance of conflict-based party competition and voter behaviour and prohibiting the emergence of 'normal' (that is, non-conflict-based) dimensions of political competition. However, drawing on evidence from a post-election survey at the 2009 Northern Ireland election to the European Parliament, I find that EU issues determined intra-bloc vote choice (at least in the nationalist community). This suggests that there is potential for regional integration projects, such as the EU, to contribute to the normalisation of politics in a consociational system by acting as the source of an externally generated dimension of political competition. © 2012 Macmillan Publishers Ltd.

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Two arsenic- and heavy metal-contaminated mine-spoil sites, at Carrock Fell, Cumbria and Devon Great Consols Mine, Devon, were found to support populations of the earthworms Lumbricus rubellus Hoffmeister and Dendrodrilus rubidus (Savigny). L. rubellus and D. rubidus collected from the Devon site and an uncontaminated site were kept for 28 days in uncontaminated soil and in soil containing sodium arsenate (494 mg As kg-1). The state of the specimens was recorded every 7 days using a semi-quantitative assessment of earthworm health (condition index, C. I.). The C. I. remained high for all specimens except those of L. rubellus and D. rubidus from uncontaminated sites, which displayed 60 and 10% mortality, respectively. L. rubellus collected from the Carrock Fell site, and L. rubellus and D. rubidus from an uncontaminated site, burrowed as rapidly into soil containing up to 1235 mg As kg-1 in the form of sodium arsenate as into uncontaminated soil when placed on the soil surface. When earthworms were allowed a choice between uncontaminated soil and soil contaminated with sodium arsenate in concentrations of up to 1235 mg As kg-1, the threshold concentration for avoidance of contaminated soil was lower for L. rubellus and D. rubidus from uncontaminated soil than for specimens from contaminated soil. There was no significant effect of pH on soil discrimination. The LC50 concentration of As for L. rubellus from Devon Great Consols was significantly higher (P < 0.001) than for L. rubellus from the uncontaminated site: 1510 and 96 mg As kg-1, respectively. © 2001 Elsevier Science Ltd. All rights reserved.

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With rising numbers of school-aged children with autism educated in mainstream classrooms and applied behaviour analysis (ABA) considered the basis of best practice, teachers’ knowledge in this field has become a key concern for inclusion. Self-reported knowledge of ABA of special needs teachers (n=165) was measured and compared to their actual knowledge of ABA demonstrated in accurate responses to a multiple-choice test. Findings reported here show that teachers’ self-perceived knowledge exceeded actual knowledge and that actual knowledge of ABA was not related to training received by government agency. Implications for teacher training are discussed.

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Investigations into the evolutionary origins of human cognition has shown that individuals’ memory for others is influenced by the latter’s behaviour in social contracts. Such research is primarily based on hypothetical or more abstract forms of social contracts, whereas an application of this knowledge to everyday health behaviours can be of great value. To address this, the current study investigated whether participants who were asked to imagine themselves in a hypothetical hazardous health scenario showed differential response sensitivity (d’) and latency (RT) to faces of hospital staff tagged with contrasting hand hygiene before touching patients: clean hands, dirty hands, or unknown hand-washing behaviour (control). The test used a two alternative forced-choice (2AFC: “old/new”) face recognition paradigm. The findings showed that d’ to dirty and clean hands was similar, but higher than for controls. Moreover, d’ was not affected by the occupation of hospital staff (nurses vs porters). The absence of memory gains towards clean or dirty hands points to the need for new strategies to remind patients to observe (and remember) the hand hygiene of others when exposed to hazardous health environments.