Bruce R. MacKay

A comparison between paper‐based and online learning in higher education

To date researchers have had difficulty establishing reliable conclusions in studies comparing traditional forms of learning (e.g. paper-based or classroom based) vs online learning in relation to student learning outcomes; no consistent results have emerged, and many studies have not been controlled for factors other than lesson mode. This paper compares the effects of presenting two versions of lessons on punctuation that differed only in their mode of presentation. Fifty-nine students completed a pre-lesson questionnaire, and after the lessons completed another questionnaire plus the [National Aeronautics and Space Administration Task Load Index] NASA-TLX which tests subjective cognitive workload stress. The results showed that students who sat the lessons on paper performed 24 per cent better than those who sat the lessons online. Reasons for this difference in learning outcomes are considered, but no clear reason is apparent in the data from this study. The study sounds a note of caution in terms of the move by tertiary institutions to online and/or blended learning, and suggests further studies are required which assess learning outcomes in different modes of learning.

A team of equals: teaching writing in the sciences

Writing across the curriculum (WAC) is a way of integrating the teaching of writing into specific academic disciplines. A problem faced in the WAC literature is how to develop a process that integrates the skills of multi‐disciplinary teams. In this project, action research was used to develop a team comprising faculty from the applied sciences and a writing teacher which had been commissioned to integrate the teaching of writing into an undergraduate horticulture course. Five features of action research were of particular importance: the foci of change and collaboration, the rational, systematic process it provided, the locating of the research in a real as opposed to controlled context, and the dual foci of action and research. Action research provided a successful process and structure for the project: outcomes included changed attitudes to writing amongst students and a deeper understanding of how students value written assessment. Unexpected outcomes included spontaneous participation of students in the action research process, the provision of useful methods of reflection for teaching staff, and the development of professional trust amongst faculty from different disciplines.

Temperature kinetics of texture changes in Actinidia chinensis ‘Hort16A’ during storage

Summary Kinetic models describing softening during storage of ‘Hort16A’ kiwifruit at different temperatures are useful tools for the development of pre-conditioning and ripening protocols. Magness-Taylor firmness, compression firmness, and stiffness were assessed for their usefulness as tools to monitor and predict softening of ‘Hort16A’ kiwifruit during storage at six storage temperatures ranging from 1.5°C to 25°C. Softening showed the same general biphasic pattern for all three measures, similar to that for green ‘Hayward’ kiwifruit, and could be described using simple exponential decay models. Magness-Taylor firmness reached an asymptotic minimum rapidly, whereas compression firmness and stiffness still decreased measurably at the end of storage. The rate of softening increased with temperature, and the biphasic pattern of the softening curves became more pronounced with later harvest dates. The effects of orchard, cane, and fruit position on parameter estimates such as rate constant, activation energy, and asymptotic firmness value, were negligible.

EFFECTS OF TEMPERATURE ON GAS EXCHANGE OF 'BRAEBURN' APPLES

Abstract Gas exchange attributes of fruits affect their responses to modified atmosphere and surface coating treatments. In this study, variations in respiration rate, internal partial pressures of O2 and CO2, and skin permeance to O2 and CO2 associated with storage at 0, 5, 10, 15, 20, 25, and 30°C were characterised in ‘Braeburn’ apples (Malus domestica Borkh.) There was an 11‐fold difference in respiration rate between fruit kept at 0 and 30°C, although permeance to each of the two respiratory gases differed only by a factor of two. The differing effects of temperature upon these two variables was responsible for the depression of internal O2 and elevation of internal CO2associated with increase in temperature from 0 to 30°C. The magnitude of decline in internal O2 was slightly greater than the increase in internal CO2 over the temperature range in the experiment. For apples that were respiring aerobically, and with a respiratory quotient of unity, this would indicate that the fruit skin had a somewhat...

Silver thiosulphate reduces ethylene‐induced flower shattering in Thalictrum delavayi

Abstract Prevention of ethylene‐induced flower shattering in stems of Thalictrum delavayi Franch. ‘Hewitts’ Double’, a new cut flower crop, was investigated. Three days after exposure to 10 μl/ litre ethylene, 41% of flowers had shattered on stems pulsed in distilled water, resulting in a vase life of 4 days. In the presence of ethylene, stems pulsed with silver thiosulphate (STS) at concentrations of Ag+ ≥ 0.2 mM exhibited 36% less flower shattering than control stems, resulting in a vase life of 11 days. The proportion of flowers exhibiting Ag+ phytotoxicity increased with concentration, but at 0.2 mM Ag+ the incidence was not different from stems pulsed in distilled water. Pulsing cut stems of T. delavayi ’Hewitts’ Double’ with STS solutions containing 0.2 mM Ag+ should reduce ethylene induced flower shattering and extend vase life.

Early nutrition of micropropagated asparagus transplants

Abstract The effect of nutrition frequency on the nursery growth of ex‐flasked transplants of two asparagus clones of two root grades was studied. Growth increased as feeding frequency with 100:34:100 mg/litre NPK increased from one feed in 5 days to daily feeding. Growth optima were not detected, indicating that higher nutrient concentrations may be required to achieve optimum growth rates. There was little overall difference between the clones with respect to absolute growth parameters, but the relative growth rate of the shoots differed between clones. Relative growth rate between root sizes (within clones) was similar. Tissue analysis indicated differences in nutrient uptake between clones. The practical implications of this work are discussed.