164 research outputs found

    A Measurement of 'Walking-the-Wall' Dynamics: An Observational Study Using Accelerometry and Sensors to Quantify Risk Associated with Vertical Wall Impact Attenuation in Trampoline Parks.

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    This study illustrates the application of a tri-axial accelerometer and gyroscope sensor device on a trampolinist performing the walking-the-wall manoeuvre on a high-performance trampoline to determine the performer dynamic conditions. This research found that rigid vertical walls would allow the trampolinist to obtain greater control and retain spatial awareness at greater levels than what is achievable on non-rigid vertical walls. With a non-rigid padded wall, the reaction force from the wall can be considered a variable force that is not constrained, and would not always provide the feedback that the trampolinist needs to maintain the balance with each climb up the wall and fall from height. This research postulates that unattenuated vertical walls are safer than attenuated vertical walls for walking-the-wall manoeuvres within trampoline park facilities. This is because non-rigid walls would provide higher g-force reaction feedback from the wall, which would reduce the trampolinist's control and stability. This was verified by measuring g-force on a horizontal rigid surface versus a non-rigid surface, where the g-force feedback was 27% higher for the non-rigid surface. Control and stability are both critical while performing the complex walking-the-wall manoeuvre. The trampolinist experienced a very high peak g-force, with a maximum g-force of approximately 11.5 g at the bottom of the jump cycle. It was concluded that applying impact attenuation padding to vertical walls used for walking-the-wall and similar activities would increase the likelihood of injury; therefore, padding of these vertical surfaces is not recommended

    Use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles: case-control study

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    Objective: To determine whether there is an association between use of substances that contain caffeine and the risk of crash in long distance commercial vehicle drivers.Design: Case-control studySetting: New South Wales (NSW) and Western Australia (WA), Australia.Participants: 530 long distance drivers of commercial vehicles who were recently involved in a crash attended by police (cases) and 517 control drivers who had not had a crash while driving a commercial vehicle in the past 12 months.Main outcome measure: The likelihood of a crash associated with the use of substances containing caffeine after adjustment for factors including age, health disorders, sleep patterns, and symptoms of sleep disorders as well as exposures such as kilometres driven, hours slept, breaks taken, and night driving schedules.Results: Forty three percent of drivers reported consuming substances containing caffeine, such as tea, coffee, caffeine tablets, or energy drinks for the express purpose of staying awake. Only 3% reported using illegal stimulants such as amphetamine (“speed”); 3,4 methylenedioxymethamphetamine (ecstasy); and cocaine. After adjustment for potential confounders, drivers who consumed caffeinated substances for this purpose had a 63% reduced likelihood of crashing (odds ratio 0.37, 95% confidence interval 0.27 to 0.50) compared with drivers who did not take caffeinated substances.Conclusions: Caffeinated substances are associated with a reduced risk of crashing for long distance commercial motor vehicle drivers. While comprehensive mandated strategies for fatigue management remain a priority, the use of caffeinated substances could be a useful adjunct strategy in the maintenance of alertness while driving

    A Qualitative Analysis of Motivators to Participation in Suicide-Focused Research from a Community-Based Australian Sample

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    Suicide prevention strategies internationally appear to be falling short of making a meaningful impact on global suicide deaths. Increasing the rates of general community participation in suicide research may improve knowledge generalisability as it relates to suicidal behaviour and leads to new suicide prevention approaches. This study aims to explore the motivations of a community-based sample to participate in suicide research. A subsample of the Australian general population took part in an online survey which is part of a multilevel suicide prevention trial. The survey concluded with an optional open-text question asking about peoples’ motivations for participating in the study; 532 participants left a response to this question. These responses were qualitatively analysed using Thematic Network Analysis. Motivations to participate in suicide research were represented by four global themes: altruism, solve systemic problems, lived experience, and personal benefit. Of these themes, three were focused on the benefit of others, while only the final theme articulated motivation to participate that was self-focused. The impact of suicide is felt throughout the wider community. This new understanding of the motivations of community-based samples to participate in suicide research should be used to increase participation rates and reach people who would not normally contribute their voice to suicide researc

    Exploring sociodemographic correlates of suicide stigma in Australia: Baseline cross-sectional survey findings from the life-span suicide prevention trial studies

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    The risk of suicidal behaviour in Australia varies by age, sex, sexual preference and Indigenous status. Suicide stigma is known to affect suicide rates and help-seeking for suicidal crises. The aim of this study was to investigate the sociodemographic correlates of suicide stigma to assist in prevention efforts. We surveyed community members and individuals who had attended specific emergency departments for suicidal crisis. The respondents were part of a large-scale suicide prevention trial in New South Wales, Australia. The data collected included demographic characteristics, measures of help-seeking and suicide stigma. The linear regression analyses conducted sought to identify the factors associated with suicide stigma. The 5426 participants were predominantly female (71.4 %) with a mean (SD) age of 41.7 (14.8) years, and 3.9 % were Indigenous. Around one-third of participants reported a previous suicide attempt (n = 1690, 31.5 %) with two-thirds (n = 3545, 65.3 %) seeking help for suicidal crisis in the past year. Higher stigma scores were associated with Indigenous status (β 0.123, 95 % CI 0.074 – 0.172), male sex (β 0.527, 95 % CI 0.375 – 0.626) and regional residence (β 0.079, 95 % CI 0.015 – 0.143). Lower stigma scores were associated with younger age (β − 0.002, 95 % CI − 0.004 – − 0.001), mental illness (β − 0.095, 95 % CI − 0.139 to − 0.050), male bisexuality (β − 0.202, 95 % CI − 0.351 to − 0.052) and males who glorified suicide (β − 0.075, 95 % CI − 0.119 to − 0.031). These results suggested that suicide stigma differed across the community, varying significantly by sex, sexual orientation and Indigenous status. Targeted educational programs to address suicide stigma could assist in suicide prevention efforts

    Temperature responses of Rubisco from Paniceae grasses provide opportunities for improving C3 photosynthesis.

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    Enhancing the catalytic properties of the CO2-fixing enzyme Rubisco is a target for improving agricultural crop productivity. Here, we reveal extensive diversity in the kinetic response between 10 and 37 °C by Rubisco from C3 and C4 species within the grass tribe Paniceae. The CO2 fixation rate (kcatc) for Rubisco from the C4 grasses with nicotinamide adenine dinucleotide (NAD) phosphate malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PCK) photosynthetic pathways was twofold greater than the kcatc of Rubisco from NAD-ME species across all temperatures. The declining response of CO2/O2 specificity with increasing temperature was less pronounced for PCK and NADP-ME Rubisco, which would be advantageous in warmer climates relative to the NAD-ME grasses. Modelled variation in the temperature kinetics of Paniceae C3 Rubisco and PCK Rubisco differentially stimulated C3 photosynthesis relative to tobacco above and below 25 °C under current and elevated CO2. Amino acid substitutions in the large subunit that could account for the catalytic variation among Paniceae Rubisco are identified; however, incompatibilities with Paniceae Rubisco biogenesis in tobacco hindered their mutagenic testing by chloroplast transformation. Circumventing these bioengineering limitations is critical to tailoring the properties of crop Rubisco to suit future climates

    Advanced EFL learners' beliefs about language learning and teaching: a comparison between grammar, pronunciation, and vocabulary

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    This paper reports on the results of a study exploring learners’ beliefs on the learning and teaching of English grammar, pronunciation and vocabulary at tertiary level. While the importance of learners’ beliefs on the acquisition process is generally recognized, few studies have focussed on and compared learners’ views on different components of the language system. A questionnaire containing semantic scale and Likert scale items probing learners’ views on grammar, pronunciation and vocabulary was designed and completed by 117 native speakers of Dutch in Flanders, who were studying English at university. The analysis of the responses revealed that (i) vocabulary was considered to be different from grammar and pronunciation, both in the extent to which an incorrect use could lead to communication breakdown and with respect to the learners’ language learning strategies, (ii) learners believed in the feasibility of achieving a native-like proficiency in all three components, and (iii) in-class grammar, pronunciation and vocabulary exercises were considered to be useful, even at tertiary level. The results are discussed in light of pedagogical approaches to language teaching

    Effects of reduced carbonic anhydrase activity on CO₂ assimilation rates in Setaria viridis: a transgenic analysis

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    In C₄ species, the major β-carbonic anhydrase (β-CA) localized in the mesophyll cytosol catalyses the hydration of CO₂ to HCO₃-, which phosphoenolpyruvate carboxylase uses in the first step of C₄ photosynthesis. To address the role of CA in C₄ photosynthesis, we generated transgenic Setaria viridis depleted in β-CA. Independent lines were identified with as little as 13% of wild-type CA. No photosynthetic defect was observed in the transformed lines at ambient CO₂ partial pressure (pCO₂). At low pCO₂, a strong correlation between CO₂ assimilation rates and CA hydration rates was observed. C18O16O isotope discrimination was used to estimate the mesophyll conductance to CO₂ diffusion from the intercellular air space to the mesophyll cytosol (gm) in control plants, which allowed us to calculate CA activities in the mesophyll cytosol (Cm). This revealed a strong relationship between the initial slope of the response of the CO₂ assimilation rate to cytosolic pCO₂ (ACm) and cytosolic CA activity. However, the relationship between the initial slope of the response of CO₂ assimilation to intercellular pCO₂ (ACi) and cytosolic CA activity was curvilinear. This indicated that in S. viridis, mesophyll conductance may be a contributing limiting factor alongside CA activity to CO₂ assimilation rates at low pCO₂.This research was supported by the Bill and Melinda Gates Foundation’s funding for the C₄ Rice consortium and by the Australian Research Council Centre of Excellence for Translational Photosynthesis (CE140100015). RES is funded by ARC DECRA (DE130101760)

    The effectiveness of different explicit vocabulary-teaching strategies on learners’ retention of technical and academic words

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    The effectiveness of explicit instruction, within the context of strategy development in learners, has been widely accepted for several years. However, the methods used within explicit vocabulary instruction are varied and comparatively few studies have directly compared methods. This study investigates the type of instruction (in a visual or written context) as well as the timing of the activity (before or after the main activity). Seventy Arabic learners of English were tested in a 2*2 design. Results showed a positive effect for pre-teaching vocabulary in a visual condition. We conclude that this pre-emptive multimodal approach heightens the learners’ ability to notice vocabulary items thus providing an effective strategy to increase vocabulary intake

    A cross-scale analysis to understand and quantify the effects of photosynthetic enhancement on crop growth and yield across environments

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    Abstract Photosynthetic manipulation provides new opportunities for enhancing crop yield. However, understanding and quantifying the importance of individual and multiple manipulations on the seasonal biomass growth and yield performance of target crops across variable production environments is limited. Using a state-of-the-art cross-scale model in the APSIM platform we predicted the impact of altering photosynthesis on the enzyme-limited (Ac) and electron transport-limited (Aj) rates, seasonal dynamics in canopy photosynthesis, biomass growth, and yield formation via large multiyear-by-location crop growth simulations. A broad list of promising strategies to improve photosynthesis for C3 wheat and C4 sorghum were simulated. In the top decile of seasonal outcomes, yield gains were predicted to be modest, ranging between 0% and 8%, depending on the manipulation and crop type. We report how photosynthetic enhancement can affect the timing and severity of water and nitrogen stress on the growing crop, resulting in nonintuitive seasonal crop dynamics and yield outcomes. We predicted that strategies enhancing Ac alone generate more consistent but smaller yield gains across all water and nitrogen environments, Aj enhancement alone generates larger gains but is undesirable in more marginal environments. Large increases in both Ac and Aj generate the highest gains across all environments. Yield outcomes of the tested manipulation strategies were predicted and compared for realistic Australian wheat and sorghum production. This study uniquely unpacks complex cross-scale interactions between photosynthesis and seasonal crop dynamics and improves understanding and quantification of the potential impact of photosynthesis traits (or lack of it) for crop improvement research
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