Prospect relativity: How choice options influence decision under risk

In many theories of decision under risk (e.g., expected utility theory, rank-dependent utility theory, and prospect theory), the utility of a prospect is independent of other options in the choice set. The experiments presented here show a large effect of the available options, suggesting instead that prospects are valued relative to one another. The judged certainty equivalent for a prospect is strongly influenced by the options available. Similarly, the selection of a preferred prospect is strongly influenced by the prospects available, Alternative theories of decision under risk (e.g., the stochastic difference model, multialternative decision field theory, and range frequency theory), where prospects are valued relative to one another, can provide an account of these context effects

Autonomous and controlled motivational regulations for multiple health related behaviors: between- and within-participants analyses

Self-determination theory has been applied to the prediction of a number of health-related behaviors with self-determined or autonomous forms of motivation generally more effective in predicting health behavior than non-self-determined or controlled forms. Research has been confined to examining the motivational predictors in single health behaviors rather than comparing effects across multiple behaviors. The present study addressed this gap in the literature by testing the relative contribution of autonomous and controlling motivation to the prediction of a large number of health-related behaviors, and examining individual differences in self-determined motivation as a moderator of the effects of autonomous and controlling motivation on health behavior. Participants were undergraduate students (N = 140) who completed measures of autonomous and controlled motivational regulations and behavioral intention for 20 health-related behaviors at an initial occasion with follow-up behavioral measures taken four weeks later. Path analysis was used to test a process model for each behavior in which motivational regulations predicted behavior mediated by intentions. Some minor idiosyncratic findings aside, between-participants analyses revealed significant effects for autonomous motivational regulations on intentions and behavior across the 20 behaviors. Effects for controlled motivation on intentions and behavior were relatively modest by comparison. Intentions mediated the effect of autonomous motivation on behavior. Within-participants analyses were used to segregate the sample into individuals who based their intentions on autonomous motivation (autonomy-oriented) and controlled motivation (control-oriented). Replicating the between-participants path analyses for the process model in the autonomy- and control-oriented samples did not alter the relative effects of the motivational orientations on intention and behavior. Results provide evidence for consistent effects of autonomous motivation on intentions and behavior across multiple health-related behaviors with little evidence of moderation by individual differences. Findings have implications for the generalizability of proposed effects in self-determination theory and intentions as a mediator of distal motivational factors on health-related behavior

Small ruminant production in the humid tropics

Research review on sheep and goat production in the humid zone of West Africa, w. respect to animal population, production parameters, reproduction, forage production, supplementary feeding based on agro - industrial byproducts, disease incidence, particularly peste petits ruminants & helminthiasis, housing, and economic aspects of small and large scale production, w. proposals for further research

Who uses foodbanks and why? Exploring the impact of financial strain and adverse life events on food insecurity

Background Rising use of foodbanks highlights food insecurity in the UK. Adverse life events (e.g. unemployment, benefit delays or sanctions) and financial strains are thought to be the drivers of foodbank use. This research aimed to explore who uses foodbanks, and factors associated with increased food insecurity. Methods We surveyed those seeking help from front line crisis providers from foodbanks (N = 270) and a comparison group from Advice Centres (ACs) (N = 245) in relation to demographics, adverse life events, financial strain and household food security. Results About 55.9% of foodbank users were women and the majority were in receipt of benefits (64.8%). Benefit delays (31.9%), changes (11.1%) and low income (19.6%) were the most common reasons given for referral. Compared to AC users, there were more foodbank users who were single men without children, unemployed, currently homeless, experiencing more financial strain and adverse life events (P = 0.001). Food insecurity was high in both populations, and more severe if they also reported financial strain and adverse life events. Conclusions Benefit-related problems appear to be a key reason for foodbank referral. By comparison with other disadvantaged groups, foodbank users experienced more financial strain, adverse life events, both increased the severity of food insecurity

Elaboration, caractérisation et comportement à l’oxydation haute température des nanomatériaux Fe1-x Alx obtenus par mécanosynthèse

Actuellement, les recherches s'orientent vers la production de matériaux pour lesquels les futures propriétés pourraient être contrôlées par la maîtrise de la microstructure. A ce sujet, nous utiliserons dans ce travail le procédé d'élaboration par mécano synthèse. Nous avons choisi de synthétiser les composés intermétalliques du système Fe<sub>1-x</sub> Al<sub>x</sub> (x=20, 35, 50 %) et d‟étudier leur comportement à l‟oxydation haute température. Le broyage à haute énergie a permis d‟élaborer, à partir de métaux purs, des mélanges homogènes et nanostructurés. Les conditions de broyage utilisées conduisent à la formation d‟une phase homogène après 7h de broyage et cela quelle que soit la composition du mélange initial. La caractérisation des poudres a été réalisée par la microscopie électronique à balayage (MEB) et la diffraction des rayons X (DRX). Nous avons effectué des essais d‟oxydation à haute température sur trois alliages binaires FeAl à 1 000 °C, dans une atmosphère d'air de laboratoire et à pression atmosphérique. Les essais d‟oxydation menés à 1000 °C présentent deux stades : un premier stade transitoire avec une cinétique à croissance rapide liée à la présence des alumines métastables et un deuxième stade stationnaire associé à la croissance de l‟alumine. Le taux d‟oxydation diminue avec l‟augmentation de la teneur en Al.Mots clés: Alliage Fe -Al- Mécanosynthèse – Nanomatériaux - oxydation haute températur

Effective behaviour change techniques in the prevention and management of childhood obesity

Rates of childhood obesity are increasing, and it is essential to identify the active components of interventions aiming to prevent and manage obesity in children. A systematic review of behaviour change interventions was conducted to find evidence of behaviour change techniques (BCTs) that are most effective in changing physical activity and/or eating behaviour for the prevention or management of childhood obesity. An electronic search was conducted for randomised controlled trials published between January 1990 and December 2009. Of 4309 titles and abstracts screened, full texts of 135 articles were assessed, of which 17 published articles were included in this review. Intervention descriptions were coded according to the behaviour-specific CALO-RE taxonomy of BCTs. BCTs were identified and compared across obesity management (n=9) vs prevention (n=8) trials. To assess the effectiveness of individual BCTs, trials were further divided into those that were effective (defined as either a group reduction of at least 0.13 body mass index (BMI) units or a significant difference in BMI between intervention and control groups at follow-up) vs non-effective (reported no significant differences between groups). We reliably identified BCTs utilised in effective and non-effective prevention and management trials. To illustrate the relative effectiveness of each BCT, effectiveness ratios were calculated as the ratio of the number of times each BCT was a component of an intervention in an effective trial divided by the number of times they were a component of all trials. Results indicated six BCTs that may be effective components of future management interventions (provide information on the consequences of behaviour to the individual, environmental restructuring, prompt practice, prompt identification as role model/position advocate, stress management/emotional control training and general communication skills training), and one that may be effective in prevention interventions (prompting generalisation of a target behaviour). We identified that for management trials, providing information on the consequences of behaviour in general was a feature of non-effective interventions and for prevention trials, providing information on the consequences of behaviour in general, providing rewards contingent on successful behaviour and facilitating social comparison were non-effective. To design effective behaviour change programmes for the prevention and management of childhood obesity, we would recommend utilising the BCTs identified as effective in this review. The impact on intervention effectiveness of combining BCTs should be the topic of further research

Surface enhancement of oxygen exchange and diffusion in the ionic conductor La2Mo2O9

Isotopic surface oxygen exchange and its subsequent diffusion have been measured using secondary ion mass spectrometry in the fast ionic conductor La2Mo2O9. A silver coating was applied to the sample surface to enhance the surface exchange process for dry oxygen. Contrary to previous studies performed using a wet atmosphere, no grain boundary diffusion tail was observed under these optimized dry exchange conditions. The activation energy for oxygen diffusion was found to be 0.66(+/- 0.09) eV at high temperature (>570 degrees C), and 1.25(+/- 0.01)eV at low temperature (<570 degrees C). Time-of-Flight secondary ion mass spectrometry was employed to investigate the correlation between the silver coating and the O-18 concentration on the sample surface. A close correlation between the presence of silver and oxygen incorporation on the surface was observed. (C) 2010 Elsevier B.V. All rights reserved

Domain effects and financial risk attitudes

We investigated whether financial risk preferences are dependent on the financial domain (i.e., the context) in which the risky choice options are presented. Previous studies have demonstrated that risk attitudes change when gambles are framed as gains, losses, or as insurance. Our study explores this directly by offering choices between identical gambles, framed in terms of seven financial domains. Three factors were extracted, explaining 68.6% of the variance: Factor 1 (Positive)—opportunity to win, pension provision, and job salary change; Factor 2 (Positive-Complex)—investments and mortgage buying; Factor 3 (Negative)—possibility of loss and insurance. Inspection of the solution revealed context effects on risk perceptions across the seven scenarios. We also found that the commonly accepted assumption that women are more risk averse cannot be confirmed with the context structure suggested in this research; however, it is acknowledged that in the students’ population the variance across genders might be considerably less. These results suggest that our financial risk attitude measures may be tapping into a stable aspect of “context dependence” of relevance to real-world decision making

Aneurysmal bone cyst primary - about eight pediatric cases: radiological aspects and review of the literature

The aneurysmal bone cyst is a pseudotumoral lesion that can take several aspects. This is a rare lesion representing 1% of bone tumors. It appears usually during the first 30 years of life. The pathogenesis is that of a process of "dysplasia/hyperplasia", favored by a circulatory deficiency and hemorrhage within the lesion and the phenomena of osteoclasis. The objective of this work is to illustrate with analysis, the specific forms and atypical aneurysmal bone cyst which often pose a diagnostic challenge requiring radiological investigation with histological confirmation. We report eight pediatric cases of aneurysmal cysts collected over a period of 3 years, 3 boys and 5 girls. All patients had standard radiographs. MRI was performed in three patients. The diagnosis was confirmed histologically. The atypia has been in the seat: fibula (1 case), metaphyseal (2 cases), diaphyseal (4 cases) and metatarsal (1 case). Aneurysmal bone cyst is a rare benign tumor with predilection to the metaphysis of long bones. Atypical forms even fewer are dominated by the atypical seat.Key words: Bone cyst, aneurysm, osteolytic lesio