424 research outputs found
Basic Psychological Need Satisfaction, Stress-Related Appraisals, and Dancers’ Cortisol and Anxiety Responses \ud
Self-determination theory (Deci & Ryan, 2000) posits basic psychological need satisfaction (BPNS) as essential for optimal functioning and health. Grounded in this framework, the current study examined the role of BPNS in dancers’ cognitive appraisals and hormonal and emotional responses to performance stress. Dancers reported their degree of BPNS 1 month before a solo performance. Threat and challenge appraisals of the solo were recorded 2 hr before the performance. Salivary cortisol and anxiety were measured 15 min before, and 15, 30, 45, and 60 min postperformance. Higher BPNS was associated with lower cortisol responses and anxiety intensity. Challenge appraisals mediated the association between BPNS and cortisol. Threat appraisals mediated the BPNS–anxiety intensity relationship. These findings point to the potential importance of performers’ BPNS for optimal emotional and hormonal homeostasis in performance conditions.\ud
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Setting the stage: social-environmental and motivational predictors of optimal training engagement
In this paper, we will firstly explore the central tenets of SDT. Research that has examined the social-environmental and motivation-related correlates of optimal training, performance and health-related engagement through the theoretical lens of SDT will be reviewed. Drawing from SDT-driven work undertaken in educational, sport and dance settings, we will draw conclusions and suggest future directions from a research and applied perspective
Reconstruction of 2D Al Ti on TiB in an aluminium melt
It has been widely considered that Al Ti is involved in the aluminium nucleation on TiB , although the mechanism has not been fully understood. In this paper molecular dynamics has been conducted to investigate this phenomenon at an atomistic scale. It was found that a two-dimensional Al Ti layer may remain on TiB above the aluminium liquidus. In addition, the results showed that this 2D Al Ti undergoes interface reconstruction by forming a triangular pattern. This triangular pattern consists of different alternative stacking sequences. The transition region between the triangles forms an area of strain concentration. By means of this mechanism, this interfacial Al Ti layer stabilizes itself by localizing the large misfit strain between TiB and Al Ti This reconstruction is similar to the hdp-fcc interface reconstruction in other systems which has been observed experimentally.EPSR
Culture change in elite sport performance teams: Examining and advancing effectiveness in the new era
Reflecting the importance of optimizing culture for elite teams, Fletcher and Arnold (2011) recently suggested the need for expertise in culture change. Acknowledging the dearth of literature on the specific process, however, the potential effectiveness of practitioners in this area is unknown. The present paper examines the activity's precise demands and the validity of understanding in sport psychology and organizational research to support its delivery. Recognizing that sport psychologists are being increasingly utilized by elite team management, initial evidence-based guidelines are presented. Finally, to stimulate the development of ecologically valid, practically meaningful knowledge, the paper identifies a number of future research directions
The role of reducing food waste for resilient food systems
Food waste undermines long-term resilience of the global food system by aggravating ecosystem damage. The
global community must therefore work to reduce the amount of food that gets wasted. However, we should be
mindful of some potential conflicts between food waste reduction and food system resilience. Over-production
and over-supply are a contributing cause of waste, yet they also provide resilience in the form of redundancy. In
this paper, we examine individual interventions designed to minimise food waste by scoring their impact on
different aspects of resilience. We find that there are strong synergistic elements and interventions that support
short- and long-term resilience, such as improved storage, which reduces the need to provide a constant flow of
‘surplus food’ and replaces it with a stock of ‘spare’ food. Some interventions carry a risk of trade-offs due to
possible losses of redundancy, and investment lock-in that may reduce the ability of farmers to adapt by
changing what and where they farm. Trade-offs do not mean that those interventions should not be pursuit, but
they should be recognised so that can be adequately addressed with complimentary actions. This review underlines the necessity of food-systems thinking and joined-up policy
The Influence of the effect of solute on the thermodynamic driving force on grain refinement of Al alloys
Grain refinement is known to be strongly affected by the solute in cast alloys. Addition of some solute can reduce grain size considerably while others have a limited effect. This is usually attributed to the constitutional supercooling which is quantified by the growth restriction factor, Q. However, one factor that has not been considered is whether different solutes have differing effects on the thermodynamic driving force for solidification. This paper reveals that addition of solute reduces the driving force for solidification for a given undercooling, and that for a particular Q value, it is reduced more substantially when adding eutectic-forming solutes than peritectic-forming elements. Therefore, compared with the eutectic-forming solutes, addition of peritectic-forming solutes into Al alloys not only possesses a higher initial nucleation rate resulted from the larger thermodynamic driving force for solidification, but also promotes nucleation within the constitutionally supercooled zone during growth. As subsequent nucleation can occur at smaller constitutional supercoolings for peritectic-forming elements, a smaller grain size is thus produced. The very small constitutional supercooling required to trigger subsequent nucleation in alloys containing Ti is considered as a major contributor to its extraordinary grain refining efficiency in cast Al alloys even without the deliberate addition of inoculants.The Australian Research Council (ARC DP10955737)
Cyber Insurance: recent advances, good practices & challenges
The aim of this ENISA report is to raise awareness for the most impact to market advances, by shortly identifying the most significant cyber insurance developments for the past four years – during 2012 to 2016 – and to capture the good practices and challenges during the early stages of the cyber insurance lifecycle, i.e. before an actual policy is signed, laying the ground for future work in the area
Neighbour identity hardly affects litter-mixture effects on decomposition rates of New Zealand forest species.
The mass loss of litter mixtures is often different than expected based on the mass loss of the component species. We investigated if the identity of neighbour species affects these litter-mixing effects. To achieve this, we compared decomposition rates in monoculture and in all possible two-species combinations of eight tree species, widely differing in litter chemistry, set out in two contrasting New Zealand forest types. Litter from the mixed-species litter bags was separated into its component species, which allowed us to quantify the importance of litter-mixing effects and neighbour identity, relative to the effects of species identity, litter chemistry and litter incubation environment. Controlling factors on litter decomposition rate decreased in importance in the order: species identity (litter quality) >> forest type >> neighbour species. Species identity had the strongest influence on decomposition rate. Interspecific differences in initial litter lignin concentration explained a large proportion of the interspecific differences in litter decomposition rate. Litter mass loss was higher and litter-mixture effects were stronger on the younger, more fertile alluvial soils than on the older, less-fertile marine terrace soils. Litter-mixture effects only shifted percentage mass loss within the range of 1.5%. There was no evidence that certain litter mixtures consistently showed interactive effects. Contrary to common theory, adding a relatively fast-decomposing species generally slowed down the decomposition of the slower decomposing species in the mixture. This study shows that: (1) species identity, litter chemistry and forest type are quantitatively the most important drivers of litter decomposition in a New Zealand rain forest; (2) litter-mixture effects—although statistically significant—are far less important and hardly depend on the identity and the chemical characteristics of the neighbour species; (3) additive effects predominate in this ecosystem, so that mass dynamics of the mixtures can be predicted from the monocultures
Grain refinement of magnesium alloys: a review of recent research, theoretical developments and their application
This paper builds on the ‘‘Grain Refinement of Mg Alloys’’ published in 2005 and reviews the grain refinement research onMg alloys that has been undertaken since then with an emphasis on the theoretical and analytical methods that have been developed. Consideration of recent research results and current theoretical knowledge has highlighted two important factors that affect an alloy’s as-cast grain size. The first factor applies to commercial Mg-Al alloys where it is concluded that impurity and minor elements such as Fe and Mn have a substantially negative impact on grain size because, in combination with Al, intermetallic phases can be formed that tend to poison the more potent native or deliberately added nucleant particles present in the melt. This factor appears to explain the contradictory experimental outcomes reported in the literature and suggests that the search for a more potent and reliable grain refining technology may need to take a different approach. The second factor applies to all alloys and is related to the role of constitutional supercooling which, on the one hand, promotes grain nucleation and, on the other hand, forms a nucleation-free zone preventing further nucleation within this zone, consequently limiting the grain refinement achievable, particularly in low solute-containing alloys. Strategies to reduce the negative impact of these two factors are discussed. Further, the Interdependence model has been shown to apply to a broad range of casting methods from slow cooling gravity die casting to fast cooling high pressure die casting and dynamic methods such as ultrasonic treatment
Protocol for the Residents in Action pilot cluster-randomised controlled trial (RiAT): Evaluating a behaviour change intervention to promote walking, reduce sitting and improve mental health in physically inactive older adults in 9 retirement villages
Introduction: Ageing is accompanied by increased risks of chronic disease, declined functioning and increased dependency. Physical activity is critical to retaining health and independence, but the majority of older people are insufficiently physically active to achieve these benefits and have high levels of sedentary (sitting) time. Activity programmes are often offered in retirement villages; however, their uptake is limited. Furthermore, although the physical environment in and around these villages can play an important role in decisions to be physically active, its role is often overlooked by research in these settings. We aim to develop, implement and evaluate a proof-of- concept motivationally embellished intervention designed to increase walking, reduce sitting and improve mental health in residents in retirement villages. Methods and analysis: This will be a 16-week pilot intervention using a cluster randomised design with retirement villages as the unit of randomisation and residents as the unit of assessment. Fourteen retirement villages around Perth, Western Australia, will be recruited for the intervention. Objective audits of neighbourhood environments around each village will be completed using the Pathway Environmental Audit Tool. Seven villages will be randomised to the experimental arm and seven to the control arm. Only participants in the experimental arm will receive motivational training. All outcomes will be assessed at baseline, end of intervention and 6-month follow-up. Changes in physical activity levels, sitting time and mental health will be examined. Multilevel modelling will be used to analyse the data. A mixed methods process evaluation will also be conducted. Ethics and dissemination: Ethics approval was granted by Curtin University’s Human Research Ethics Committee (HREC2016-0187). The results of the study will be disseminated via peer-reviewed publications, conference presentations and reports to, and seminars with, stakeholders
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