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Comparing the effects of goal types in a walking session with healthy adults: preliminary evidence for open goals in physical activity
No full textObjectives Goal-setting is one of the most common strategies used to increase physical activity. Current practice is often based on specific, measurable, achievable, realistic, and time-bound (SMART) goals. However, theory and research suggests that this approach may be problematic. Open goals (e.g., “see how well you can do”) have emerged as a possible alternative, but are yet to be tested experimentally in physically active tasks. In a walking-based session, this study aimed to experimentally compare the effects of open, SMART and do-your-best goals with a control condition on distance walked and psychological variables related to engagement. Design Repeated measures design (mixed model). Method Participants (N = 78; Mage = 55.88) were randomly assigned to one of four goal conditions: an open, SMART, or do-your-best goal, or a control condition (“walk at your normal pace”), before completing a baseline and two manipulated attempts of a 6-min walking test. Results Open, SMART, and do-your-best goals achieved greater distance walked, and higher ratings of perceived exertion, than the control across both experimental attempts. Open and SMART goals led to greater enjoyment of the session. However, SMART goals led to higher pressure/tension, while open goals led to higher perceptions of performance and higher interest in repeating the session. Conclusions These findings provide preliminary evidence for the efficacy of setting open goals in physical activity, and suggest that they may be more psychologically adaptive to pursue than SMART or do-your-best goals. Implications are discussed, and recommendations are made for future goal-setting research in physical activity
Developing a new generation MOOC (ngMOOC): a design-based implementation research project with cognitive architecture and student feedback in mind
No full textThis paper describes a design-based implementation research (DBIR) approach to the development and trialling of a new generation massive open online course (ngMOOC) situated in an instructional setting of undergraduate mathematics at a regional Australian university. This process is underscored by two important innovations: (a) a basis in a well-established human cognitive architecture in terms of cognitive load theory; and (b) point-of-contact feedback based in a well-tested online system dedicated to enhancing the learning process. Analysis of preliminary trials suggests that the DBIR approach to the ngMOOC construction and development supports theoretical standpoints that argue for an understanding of how design for optimal learning can utilise conditions, such as differing online or blended educational contexts, in order to be effective and scalable. The ngMOOC development described in this paper marks the adoption of a cognitive architecture in conjunction with feedback systems, offering the groundwork for use of adaptive systems that cater for learner expertise. This approach seems especially useful in constructing and developing online learning that is self-paced and curriculum-based
Does a novice technician produce results similar to that of an experienced DXA technician when assessing body composition and bone mineral density?
No full textDual energy X-ray absorptiometry is a commonly used clinical assessment tool for body composition and bone mineral density, which is gaining popularity in athletic cohorts. Results from body composition scans are useful for athletic populations to track training and nutritional interventions, whilst bone mineral density scans are valuable for athletes at risk of developing stress fractures due to low bone mineral density. However, no research has ascertained if a novice technician (accredited but not experienced) could produce similar results to an experienced technician. Two groups of recreational athletes were scanned, one by an experienced technician, one by a novice technician. All participants were scanned twice with repositioning between scans. The experienced technician\u27s reliability (ICC 0.989 - 0.998, percentage change in mean -0.01 - 0.10), precision (typical error as CV% 0.01 to 0.47. standard error of measurement percentage 0.61% - 1.39%) and sensitivity to change (smallest real difference percentage 1.70% - 3.85%) were similar, however superior, to those of the novice technician. The novice technician results were: reliability (ICC 0.985 - 0.997, percentage change in mean -0.03 - 0.23), precision (typical error as CV% 0.03 - 0.75%, standard error of measurement percentage 1.06% - 2.12%) and sensitivity to change (smallest real difference percentage 2.73% - 5.86%). Extensive experience whilst valuable is not a necessary requirement to produce quality results when undertaking whole body dual energy X-ray absorptiometry scanning
Invasion-mediated effects on marine trophic interactions in a changing climate: positive feedbacks favour kelp persistence
No full textThe interactive effects of ocean warming and invasive species are complex and remain a source of uncertainty for projecting future ecological change. Climate-mediated change to trophic interactions can have pervasive ecological consequences, but the role of invasion in mediating trophic effects is largely unstudied. Using manipulative experiments in replicated outdoor mesocosms, we reveal how near-future ocean warming and macrophyte invasion scenarios interactively impact gastropod grazing intensity and preference for consumption of foundation macroalgae ( Ecklonia radiata and Sargassum vestitum). Elevated water temperature increased the consumption of both macroalgae through greater grazing intensity. Given the documented decline of kelp ( E. radiata) growth at higher water temperatures, enhanced grazing could contribute to the shift from kelp-dominated to Sargassum-dominated reefs that is occurring at the low-latitude margins of kelp distribution. However, the presence of a native invader ( Caulerpa filiformis) was related to low consumption by the herbivores on dominant kelp at warmer temperatures. Thus, antagonistic effects between climate change and a range expanding species can favour kelp persistence in a warmer future. Introduction of species should, therefore, not automatically be considered unfavourable under climate change scenarios. Climatic changes are increasing the need for effective management actions to address the interactive effects of multiple stressors and their ecological consequences, rather than single threats in isolation
Energy costs of salt tolerance in crop plants
No full textAgriculture is expanding into regions that are affected by salinity. This review considers energy costs of salinity tolerance in crop plants and provides a framework for a quantitative assessment of costs. Different sources of energy, and modifications of root system architecture that would maximise water versus ion uptake are addressed. Energy requirements for transport of NaCl to leaf vacuoles for osmotic adjustment could be small if there are no substantial leaks back across plasma membrane and tonoplast in root and leaf. The coupling ratio of H+‐ATPase is also a critical component. One proposed leak, that of Na+ influx across the plasma membrane through certain aquaporin channels, might be coupled to water flow, thus conserving energy. For the tonoplast, control of two types of cation channels is required for energy efficiency. Transporters controlling the Na+ and Cl– concentrations in mitochondria and chloroplasts are largely unknown and could be a major energy cost. The complexity of the system will require a sophisticated modelling approach to identify critical transporters, apoplastic barriers and root structures. This modelling approach will inform experimentation and allow a quantitative assessment of the energy costs of salt tolerance to guide breeding and engineering of molecular components
Songs of a changeling earth
No full textSongs of a Changeling Earth is an exhibition of media art, produced by Grayson Cooke during his artist residency at Geoscience Australia during 2018. This exhibition focuses on three significant area of Geoscience Australia\u27s operations: the National Mineral and Fossil Collection, the Petroleum Data Repository, and the Digital Earth Australia satellite-imaging program
When times get tough: savoring and relationship satisfaction in couples coping with a stressful life event
No full textBackground and objectives: When couples face a stressful life event, this can adversely impact relationship satisfaction. Because savoring positive experiences is thought to enhance intimate relationships and there is evidence that savoring buffers the negative effects of stress at the intrapersonal level, this study examined savoring as an interpersonal resource for couples who experienced a stressful life event.Methods: One hundred and twenty-eight opposite-sex couples completed measures of impact of event, savoring, positive affect, and relationship satisfaction.Results: Results from actor-partner interdependence models found that: (1) For couple members who reported a relatively low impact of event, their own savoring was positively predicted by their partner\u27s impact of event; (2) For women, their own savoring the moment predicted their own and their partner\u27s greater relationship satisfaction; (3) The relationship between one\u27s own impact of event and relationship satisfaction was buffered by one\u27s partner\u27s savoring the moment; and (4) The relationship between one\u27s own savoring and relationship satisfaction was mediated by one\u27s own positive affect.Conclusions: The findings support the study of savoring as an interpersonal resource in times of stress and have implications for couples-based interventions
Development of analytical and numerical models for predicting the mechanical properties of structural adhesives under curing using the PZT-based wave propagation technique
No full textStructural adhesives are commonly used as bonding agents in fibre-reinforced polymer based strengthening systems for concrete structures. The effectiveness and integrity of the bonding layer can be ascertained by monitoring the stiffness and strength development of the structural adhesive throughout the curing process. Previous studies have shown that the piezoelectric-based wave propagation (WP) technique is a viable technology for such monitoring. While there is a limited number of experimental data that verifies the technology, there are no known modelling studies. This paper therefore reports the first analytical and numerical modelling study for the WP technique in monitoring the curing process of structural adhesives. An experimental program is also reported to support the modelling. Tests are firstly conducted with the WP technique to obtain the pressure wave (P-wave) velocity. Tensile tests are then conducted to determine the ultimate tensile strength and static modulus of elasticity of the structural adhesives. Based on the P-wave velocity, the dynamic modulus of elasticity can be evaluated analytically from the elastic wave equation as well as numerically through model updating with the development of a three-dimensional coupled field finite element model. Finally, semi-analytical and semi-numerical relationships are established to predict the ultimate tensile strength of the structural adhesives from the P-wave velocity. This proof-of-concept study shows that the WP technique is capable of continuous and real-time monitoring of the curing process of structural adhesives. With the aid of the models, the WP technique can potentially eliminate the need to conduct destructive tensile tests
