Éditorial

Editorial 22, 2 (2019)Éditorial 22, 2 (2019

Students’ Language Repertoires for Prediction

Communication about prediction is complex in a number of ways. First, language is by nature recursive — language is an indicator of meaning as well as a force that shapes meaning. Second, the same language used to communicate prediction in uncertain environments is used for other purposes. In this article, we describe how the recursive nature of language impacted the choices we made in a cross-sectional longitudinal study aimed at gaining insight into children’s language repertoires relating to conjecture. We then explore some Grade 6 students’ communication about prediction to develop insight into their meaning and meaning-making with prediction language. From this we raise questions about interpreting data from such contexts. Finally, we discuss implications for educators

Students’ Language Repertoires for Prediction

Communication about prediction is complex in a number of ways. First, language is by nature recursive — language is an indicator of meaning as well as a force that shapes meaning. Second, the same language used to communicate prediction in uncertain environments is used for other purposes. In this article, we describe how the recursive nature of language impacted the choices we made in a cross-sectional longitudinal study aimed at gaining insight into children’s language repertoires relating to conjecture. We then explore some Grade 6 students’ communication about prediction to develop insight into their meaning and meaning-making with prediction language. From this we raise questions about interpreting data from such contexts. Finally, we discuss implications for educators

A SYSTEMATIC REVIEW OF METHODOLOGIES USED TO ASSESS “UNANTICIPATED” CUTTING MECHANICS

Biomechanical analysis of cutting mechanics is a popular approach to assessing risk factors for injuries such as anterior cruciate ligament ruptures. The purpose of this study was to systematically review the methodological approaches to assessing unanticipated cutting mechanics and provide a review of such approaches. A total of 93 articles where identified that had assessed unanticipated cutting. The most common methodological design was a 45° cutting task following a run-up where the direction of the cut was determined by a light-based stimulus. External light stimuli create a worst-case scenario by providing information about the task at the last moment meaning opportunity for preparatory mechanics is limited. However, light stimuli do not allow for perception-action to take place and may therefore not truly reflect an athlete’s cutting mechanics

Editorial * Éditorial

20, 1 (2017

Editorial/Éditorial

17, 2 (2014) Editorial/Éditoria

Enabling acceptance and use of ecological intensification options through engaging smallholder farmers in semi-arid rural Limpopo and Eastern Cape, South Africa

Ecological intensification is being promoted to address food security and environmental challenges. It has shown the potential to improve yields as well as adapt and mitigate the effects of climate variability and change. Despite the great potential, smallholder farmers continue to shun the latter. Apart from this, limited research has been conducted focussing on their acceptance and use in smallholder sub-Saharan African agricultural systems. In this study, a qualitative approach using the Unified Theory of Acceptance and Use of Technology (UTAUT) four constructs (performance, ease of use, social influence and enablers) was used to assess behavioral intention to accept and use ecological intensification options. A total of 97 smallholder farmers from diverse farm types in rural Limpopo and Eastern Cape, South Africa participated in focus group discussions to assess behavioral intention to accept and use ecological intensification options. Smallholder farmers revealed that they were exposed to a plethora of ecological intensification options. However, acceptance and utilization of these options were low, mainly due to lack of awareness, germplasm, and technical support. The four constructs of the UTAUT framework revealed locally relevant knowledge that must be considered for effective acceptance and use of ecological intensification options. Abbreviations: ACCESS: Alliance for Collaboration for Climate and Earth System Sciences; ADCI: African Climate Development Initiative; NRF: National Research Foundation; SSA: Sub Saharan Africa; UTAUT: Unified Theory of Acceptance and Use of Technology; WRC: Water Research Commission; FAO: Food and Agriculture Organisation; CA: Conservation Agriculture

Key tropical crops at risk from pollinator loss due to climate change and land use

Insect pollinator biodiversity is changing rapidly, with potential consequences for the provision of crop pollination. However, the role of land use–climate interactions in pollinator biodiversity changes, as well as consequent economic effects via changes in crop pollination, remains poorly understood. We present a global assessment of the interactive effects of climate change and land use on pollinator abundance and richness and predictions of the risk to crop pollination from the inferred changes. Using a dataset containing 2673 sites and 3080 insect pollinator species, we show that the interactive combination of agriculture and climate change is associated with large reductions in insect pollinators. As a result, it is expected that the tropics will experience the greatest risk to crop production from pollinator losses. Localized risk is highest and predicted to increase most rapidly, in regions of sub-Saharan Africa, northern South America, and Southeast Asia. Via pollinator loss alone, climate change and agricultural land use could be a risk to human well-being.info:eu-repo/semantics/publishedVersio

Cognitive performance is associated with cerebral oxygenation and peripheral oxygen saturation, but not plasma catecholamines, during graded normobaric hypoxia

What is the central question of this study? What are the mechanisms responsible for the decline in cognitive performance following exposure to acute normobaric hypoxia? What are the main findings and their importance? We found that 1) performance of a complex central executive task (n-back) was reduced FiO 0.12; 2) there was a strong correlation between performance of the n-back task and reductions in SpO and cerebral oxygenation; and 3) plasma adrenaline, noradrenaline, cortisol, and copeptin were not correlated with cognitive performance. It is well established that hypoxia impairs cognitive function; however, the physiological mechanisms responsible for these effects have received relatively little attention. This study examined the effects of graded reductions in fraction of inspired oxygen (FiO ) on oxygen saturation (SpO ), cerebral oxygenation, cardiorespiratory variables, activity of the sympathoadrenal system (adrenaline, noradrenaline) and hypothalamic-pituitary-adrenal axis (cortisol, copeptin), and cognitive performance. Twelve healthy males (mean [SD], age: 22 [4] yrs, height: 178 [5] cm, mass: 75 [9] kg, FEV /FVC ratio: 85 [5] %) completed a 4-task battery of cognitive tests to examine inhibition, selective attention (Eriksen Flanker), executive function (n-back) and simple and choice reaction time (Deary-Liewald). Tests were completed before and following 60 minutes of exposure to FiO 0.2093, 0.17, 0.145, and 0.12. Following 60 minutes of exposure response accuracy in the n-back task was significantly reduced in FiO 0.12 compared to baseline (82 [9] vs. 93 [5] %; p < 0.001) and compared to all other conditions at the same time point (FiO 0.2093: 92 [3] %, FiO 0.17: 91 [6] %, FiO 0.145: 85 [10] %, FiO 12: 82 [9] %; all p < 0.05). The performance of the other tasks was maintained. Δ accuracy and Δ reaction time of the n-back task was correlated with both Δ SpO (r (9) = 0.66; p < 0.001 and r (9) = - 0.36; p = 0.037 respectively) and Δ cerebral oxygenation (r (7) = 0.55; p < 0.001 and r (7) = - 0.38; p = 0.045 respectively). Plasma adrenaline, noradrenaline, cortisol and copeptin were not significantly elevated in any condition or correlated with any of the tests of cognitive performance. These findings suggest that reductions in peripheral oxygen saturation and cerebral oxygenation, and not increased activity of the sympathoadrenal system and hypothalamic-pituitary-adrenal axis, as previously speculated, are responsible for a decrease in cognitive performance during normobaric hypoxia