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The reliability and validity of the rebound countermovement jump in national collegiate athletic association division I American football players
No full textTalpey, SW, Drake, M, Haintz, L, Belanger, A, O’Grady, MW, Young, WB, Mundy, PD, James L, Gabbett, TJ, Gardner, EC. The reliability and validity of the rebound countermovement jump in National Collegiate Athletic Association Division I American Football Players. J Strength Cond Res 39(2): 200–209, 2025—The purpose of this study was to investigate the reliability and validity of the rebound countermovement jump (R-CMJ), as an alternate test of leg muscle function to the CMJ and drop jumps (DJs). Because the first phase of the R-CMJ mimics that of the CMJ, it is hypothesized that variables obtained in phase I of the R-CMJ will be like those of a CMJ. Similarly, because the second phase of a R-CMJ mimics a DJ, it is believed that the variables obtained from phase II will be like those from a DJ. Collegiate male American football players (N 5 46) aged 18–24 years completed CMJs and R-CMJs on a portable force plate. Tests were completed on 3 separate days to determine the repeatability of select variables and to establish their validity. In addition, a subgroup (N 5 20) of players from the cohort completed DJs from both 30 cm (DJ30) and 45 cm (DJ45) to determine the concurrent validity of the variables obtained from the second phase of the R-CMJ. Most variables obtained from the CMJ and R-CMJ phase I were found to be reliable, except for time-to-take-off. The variables from the DJ30, DJ45, and R-CMJ phase II displayed moderate to good reliability; however, all coefficient of variations were .10%. Jump height achieved in the CMJ was significantly greater than that achieved in phase I of the R-CMJ. The reactive strength index was significantly different in the R-CMJ compared with the DJ from both 30 and 45 cm heights. Although the R-CMJ may be inviting for coaches to use owing to its ease and time efficiency, the results of this study highlight that it may not provide a valid representation of an athlete’s reactive strength. © 2024 National Strength and Conditioning Association
Leisure lives and children’s play : a tale of two ideals
No full textWork and leisure occupy two ends of a continuum. How work and leisure are organized pertains to ideologies and a sense of who we are. For example, in our current times, upper-/middle-class children’s leisure is frequently regulated and supervised, known as “concerted cultivation.” In contrast, “the achievement of natural growth” refers to working children spending their free time with minimum adult supervision. Likewise, two ideals regarding leisure and children’s play co-existed in Chinese history spanning over two thousand years. The exemplary child prevailing in historiographies is a juvenile prodigy who distains play, echoing the sentiment of concerted cultivation. Classical poems, however, depict an idyllic picture of the child at play uncontrived, resonating with the notion of “natural growth.” By examining these two childhood ideals, this paper discusses how Confucian and Daoist tenets shaped the concepts of leisure and work. It is argued that the two childhoods are intricately connected to ideologies traversing work, leisure, and social identities. © 2022 Taylor & Francis Group, LLC
Tensions in enacting democratic approaches in physical education teacher education
Full text linkDespite the long history of the idea of democratic education, the articulation of how teacher educators enact democratic practices remains elusive. The purpose of this research was to examine how we understand and enact democratic principles in our physical education teacher education (PETE) practices. Self-Study of Teacher Education Practices (S-STEP) methodology was used in this 18-month project. Four physical education teacher educators from different contexts examined their teaching practice and acted as critical friends to one another, generating transcripts from monthly meetings (10), individual written reflections (total of 122 pages) and diverse artifacts to question the enactment of democratic practices in PETE. Data were analysed inductively to identify turning points in how we understood democratic practices in PETE. Results indicated that our beliefs, values, and identities strongly shaped how we approached and understood democratic practice in our PETE practice. We came to see democratic practices existing on a spectrum from radical to conservative. Regardless of our individual position on this spectrum, the enactment of democratic practices is impacted by various policies, power structures, and political forces at play within our contexts. These findings illuminate several tensions teacher educators face when aiming to understand and enact democratic practices in PETE. We suggest that teacher educators may find it challenging to enact and model democratic pedagogies with pre-service teachers. However, instead of abandoning those practices, significant thought and strategising may be needed by individual teacher educators, their colleagues, and students to offer an authentic way to ‘live’ democratic pedagogies in the university in ways that align with their personal beliefs, values, and interpretations of democratic education. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
A master-slave model predictive control approach for microgrids
No full textThis article proposes a master-slave finite control set model predictive control (FCS-MPC) for microgrids. To demonstrate it, a microgrid is considered, composed of a master neutral-point clamped (NPC) inverter with a battery energy storage system (BESS) and output LC filter; two slave NPC inverters with photovoltaic (PV) panels and output LCL filters; RL and nonlinear loads. Two modes of operation are proposed for the primary control of the microgrid. In the first, the microgrid is connected to the main grid, and the master and slaves are grid-following inverters. In the second, the microgrid is islanded, and the master is a grid-forming inverter, while the slaves remain as grid-following inverters. To validate the performance of the proposed master-slave FCS-MPC, hardware-in-the-loop (HIL) results are presented for different operational conditions of the microgrid, including grid connection, transition to islanded mode, and load variations. The results demonstrate the good performance of the proposed master-slave FCS-MPC, such as fast dynamic response, multivariable control, and robustness to parametric uncertainties and variations. © 2024 IEEE
Prevalence of insomnia, nightmares and PTSD symptoms : development and testing of a multi-component cognitive behavioural treatment in Australian, Canadian, and American wildfire survivors
Full text linkWildfires are now recognised as a global crisis, posing significant threats to the economy, the environment, wildlife, physical and mental health, and human wellbeing. Sleep difficulties and trauma symptoms following the fires are highly prevalent, yet they are often neglected and inadequately treated. If left untreated, sleep and trauma symptoms can perpetuate and become unresponsive to treatment causing more complex health conditions. Therefore, the first aim of the thesis was to establish prevalence rates of sleep and trauma symptoms in an international sample of wildfire survivors. A total of 126 (23 males, 102 females, and 1 nonbinary individual, Mage = 52 years, SD = 14.4) wildfire survivors from Australia, Canada, and the United States of America (USA) took part in an online survey. Participants completed a demographic questionnaire and self-report measures including the Insomnia Severity Index (ISI), PTSD Checklist for DSM-5 (PCL-5), and Disturbing Dream and Nightmare Severity Index (DDNSI). Nearly half (49.2%) of the sample reported clinical insomnia, 28.7% reported nightmares, and 77.8% reported PTSD symptoms. In response to these alarming prevalence rates, this thesis addressed its second objective by designing and evaluating the feasibility of a digital, self-paced intervention for the treatment of sleep and trauma symptoms. Sleep Best-i, a digital and self-paced intervention, comprising of cognitive behavioural therapy for insomnia (CBTI), and exposure, relaxation, and rescripting therapy (ERRT) was evaluated in a fourweek clinical trial, targeting wildfire survivors from Australia, Canada, and the USA presenting with sleep difficulties and/or trauma symptoms. To qualify for the study, wildfire survivors had to meet at least one of the following criteria: a score ofDoctor of Philosoph
Advancing sustainable construction materials: wood and rubber geopolymer masonry mix development
Full text linkRecycling industrial waste into construction materials is becoming a fundamental strategy, offering a hopeful path toward sustainable construction practices. This study focuses on the innovative reuse of end-of-service wood and crumb rubber to develop environmentally favorable materials. Their high availability, lightweight properties, and high-energy absorption capacity make them highly suitable as additives in masonry unit production. Furthermore, using them with sustainable binding material, such as geopolymer, enhances the overall sustainability of the masonry, facilitating rapid strength development and enhancing durability while providing increased protection against fire and weathering. The study involved the development of an optimal mix design, which can potentially be used for the production of load-bearing and non-load-bearing masonry units. This was achieved by examining various proportions of wood, as well as combinations of wood and rubber, using a partial–factorial experimental design. The results show that wood-to-binder ratios ranging from 0.2 to 0.4 can potentially be used for the production of wood–geopolymer masonry units. Additionally, a ratio of 0.3 (with 50% wood and 50% rubber) was identified as potentially suitable for producing wood and rubber-based units. © The Author(s) 2025
A novel approach for monitoring training load and wellness in women’s college gymnastics
Full text linkBackground: Monitoring training load has the potential to improve sport performance and reduce injuries in athletes. This study examined training load and its association with wellness in artistic gymnastics. Hypotheses: Training load and changes in training load (acute:chronic workload ratio [ACWR]) vary throughout 1 season; wellness is inversely correlated with training load and ACWR. Study Design: Prospective case series. Level of Evidence: Level 3. Methods: A total of 30 female collegiate gymnasts from 4 Division I National Collegiate Athletic Association teams participated (mean age, 20 ± 2 years). During 4 months, before daily training, wellness surveys assessed sleep, energy, soreness, and mood (1-10; higher = better). After daily training, training load surveys assessed training duration per event (warm-up, vault, bars, beam, floor, strength and conditioning) and session rating of perceived exertion (RPE; 1-10; 10 = hardest) per event. Coaches reported technical complexity of training per event (1-4; 4 = hardest). Training load was calculated as [duration] × [RPE] × [technical complexity]. ACWR represented a ratio between acute [1-week] and chronic [4-week rolling average] training loads. Results: ACWR and weekly training load fluctuated throughout the season (ACWR mean weekly range: 0.68-1.11; training load mean weekly range: 2073-6193 arbitrary units). ACWR and weekly training loads were trichotomized into low, medium, and high groups; positive correlations were observed between each wellness variable and ACWR (P < 0.01) and between each wellness variable and weekly training load (P < 0.01). Conclusion: Our novel training load monitoring framework for women’s college gymnastics enabled us to characterize training load and its relationship with wellness throughout 1 season. This method should be explored in gymnasts across various ages and competitive levels. Clinical Relevance: This study proposes a framework and the initial findings of monitoring training load and wellness in collegiate women’s gymnastics. © 2024 The Author(s)
Agile backward design : a framework for planning higher education curriculum
Full text linkIn the last two decades there has been an increase in research and discussion regarding curriculum in Higher Education (HE). The literature in this field tends to focus on curriculum change at either the whole institution or individual program or unit level. Formal writing on HE curriculum also does not offer a framework that openly draws upon context, learner needs, pedagogical approaches, and industry requirements to formulate a collaborative model of curricular development. To fill these gaps in HE curriculum discussion and literature the aim of this study was to develop a cross-disciplinary model applicable to both unit (academic module that makes up a program) and program (degree) levels of curriculum development by enabling academics to generate and structure engaging learning opportunities for students. The research team developed this model by drawing on elements of Agile mindset and Backward Design. We call it Agile Backward Design (ABD). This paper reports on this new approach to curricular design. A critical reflective inquiry approach was used to discuss the development of the model. To report the transformation that was made at the program and unit level a case study was employed. In ABD, the researchers have constructed a dynamic and responsive framework that has been foundational in the design and development of innovative curriculum and pedagogy at the unit and program level of undergraduate degrees in the IT discipline area. © The Author(s) 2024
A review of threatened and poorly known samphires in Australia : their distribution, observed environmental threats and ecological responses
Full text linkAustralia is home to a rich assemblage of samphires (Tecticornia and Salicornia spp.) which are largely endemic, inhabiting saline and semi-saline areas across climatically diverse regions. While these plants are adapted to harsh conditions, they are vulnerable to the effects of climate change which is anticipated to exacerbate existing management and environmental pressures. Despite the threatened and priority status of many samphires, there is an overall lack of knowledge surrounding their distribution, ecology and responses to environmental threats, data which we believe is critical to support their conservation and management. We have compiled and critically assessed peer-reviewed and online grey literature and databases to provide an overview of threatened and poorly known samphires in Australia, with particular reference to their distribution, threats and ecological responses. Of the 58 species and 19 subspecies recorded in Australia, two are federally listed as threatened, eight have a formal conservation listing in at least one state or territory, and 25 are recognised as data deficient or priority taxa. Five samphire communities are also listed as threatened and seven are considered Priority Ecological Communities. We found gaps in data relevant to these threatened and priority species, with 40% having fewer than 20 distribution records available nationally. Species were distributed across 11 Conservation Management Zones (and 27 biogeographic regions). Despite their legislative protection, few species have management or recovery plans or peer reviewed ecological studies to guide conservation and management efforts. We propose further research to support effective management of these unique species and ecological communities. © The Author(s) 2025
Dynamic evolution of concrete strength grades : insights across different ages and strain rates
Full text linkThis paper investigated the dynamic response of plain concrete with three different strength grades, namely C30, C40, and C50, at an early age (3, 7, 14, and 28 days, respectively). Significant patterns were uncovered using a 75-mm-diameter split Hopkinson pressure bar (SHPB) apparatus. Initially, pronounced viscoelastic behaviour was observed in the concrete’s early stages, characterised by a sharp stress-strain curve both before and after reaching its peak. As the concrete matures, stress concentration within the stress-strain curve becomes more pronounced. Additionally, exponential growth in dynamic strength with higher strain rates was observed, while the strain rate index decreased with age. Improving concrete quality was found to reduce the sensitivity of dynamic strength to strain rate. A viscoelastic damage constitutive model was formulated based on experimental analysis to describe the mechanical response effectively. The evolution of concrete properties over time was accurately captured by fitting model parameters to the experimental data. The theoretical stress-strain curves derived from this damage model closely matched experimental curves across various ages. © The Author(s) 2024