The relationships between selected physical qualities and bowling performance, with 'match-intensity' and 'maximal-effort' deliveries in cricket pace-bowlers
- Authors: Feros, Simon , O'Brien, Brendan , Young, Warren
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Australian Strength and Conditioning Vol. 22, no. 5 (2014), p. 120-123
- Full Text: false
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The effects of implicit and explicit self-esteem on sensitivity to unfavourable performance evaluation
- Authors: Meagher, Brendan , Aidman, Eugene
- Date: 2002
- Type: Text , Journal article
- Relation: Australian Journal of Psychology Vol. 54, no. (2002), p. 44-44
- Full Text: false
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Individual differences in implicit and declared self esteem as predictors of response to negative performance evaluation : Validating implicit association test as a measure of self attitudes
- Authors: Meagher, Brendan , Aidman, Eugene
- Date: 2004
- Type: Text , Journal article
- Relation: International Journal of Testing Vol. 4, no. 1 (2004), p. 19-42
- Full Text: false
- Reviewed:
- Description: Differential and combined influence of implicit and explicit self-esteem (SE) on individual's response to negative feedback was examined in a controlled experiment. Sixty-three psychology undergraduates performed a simulated social interaction task, followed by an artificial negative feedback on their performance. Self-reported (explicit) SE was found to be predictive of participants' evaluation of the confederate who conveyed the feedback but was unrelated to their emotional response to feedback itself. The magnitude of this emotional response was predicted by an implicit SE measure derived from Implicit Association Test (IAT) but was unrelated to explicit SE. Findings are consistent with the theorized link between SE and sensitivity to criticism, thus supporting IAT's construct validity as a measure of implicit SE.
- Description: C1
- Description: 2003000957
Impacts of climate change and urban development on the spotted marsh frog (Limnodynastes tasmaniensis)
- Authors: Wilson, Joab , Bekessy, Sarah , Parris, Kirsten , Gordon, Ascelin , Heard, Geoffrey , Wintle, Brendan
- Date: 2012
- Type: Text , Journal article
- Relation: Austral Ecology Vol.38, no. 1 (2012), p.11-22
- Full Text: false
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- Description: Climate change and urbanization are among the most serious threats to amphibians, although little is known about their combined effects. We used a predictive spatial habitat suitability model to explore the potential impacts of climate change and urban development on the spotted marsh frog (Limnodynastes tasmaniensis) on the urban-fringe of Melbourne, Australia. The CSIRO climate-change predictions for the region indicate likely temperature increases of 3°C, and annual rainfall reductions of around 200mm by the year 2070. Much of the study area overlaps a region that has been identified as one of the city's growth corridors. We used Bayesian logistic regression modelling to estimate current and future habitat suitability of pond sites in the Merri Creek catchment, exploring a range of best- to worst-case scenarios through the use of hydrological and urbanization models. Our predictions for 2070, even under a moderate climate-change scenario, suggest that the majority of ponds in the study area will be dry throughout much of the year. This has obvious implications for L.tasmaniensis, which is an aquatic breeding species. However, in the short term, urbanization is likely to have a more significant effect on the distribution of L.tasmaniensis in the Merri Creek catchment, particularly if development moves beyond the current urban growth boundary. The combined effects of climate change and urbanization could have a profound impact on the species, potentially causing it to disappear from within the study area. We provide recommendations for including such predictive models in urban planning and restoration activities to prepare for future conservation challenges. © 2012 The Authors. Journal compilation © 2012 Ecological Society of Australia.
Analysis of a reactive agility test using a live tester
- Authors: Willey, Benjamin , Young, Warren , O'Brien, Brendan
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Australian Strength and Conditioning
- Relation: Vol. 27, no. 2 (2019), p. 19-31
- Full Text: false
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- Description: The utility of a reactive agility test using a live tester (LRAT) was investigated by assessing the variability and reliability of the tester’s movements. Of interest was how the tester’s actions influenced the agility measure of total test time (Ttt). Thirty-one (N=31) semi-elite Australian Rules football players were used to investigate the impact of tester time (TT) variability. A single subject was employed as the test presenter. The LRAT was presented to the playing group on two occasions (test 1 and test 2) separated by a period of 47 days. The impact of the TT on the subject’s agility was investigated for test 1 only. The TT displayed between subject variability within a session. The TT was initiated by the testers’ forward movement and ceased the instant the tester planted his outside foot to change direction. This was represented by the coefficient of variation, and the range expressed as a percentage of the mean. These were 4.8% and 25.6%, respectively. To understand the impact of this, subjects were ranked from fastest to slowest for Ttt, before being re-ranked after the TT was removed. This resulted in 22 out of the 31 subjects changing rank. The test-retest for the TT revealed a very large and significant decrease in time (p = .0001). This was accompanied by an intraclass correlation coefficient (ICC) of -0.04. Thus, the TT failed to provide a stable measure. Based on these findings it is recommended that measures such as agility time (AT), i.e. Ttt minus the TT, be used instead of Ttt. Further, isolating measures of perception and decision-making abilities (PDM) from the physical qualities is recommended to enhance agility inferences.
Discussion of “Behaviour of a Foam Mixture as a Lightweight Construction Material” [Int J of Geosynth and Ground Eng (2021) 7(3), 51]
- Authors: O’Kelly, Brendan , Soltani, Amin
- Date: 2022
- Type: Text , Journal article
- Relation: International Journal of Geosynthetics and Ground Engineering Vol. 8, no. 2 (2022), p.
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Decision-making accuracy in reactive agility: Quantifying the cost of poor decisions
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 27, no. 11 (2013), p. 3190-3196
- Full Text: false
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- Description: Decision-making accuracy and the time cost of incorrect responses was compared between higher- (n = 14) and lowerstandard (n = 14) Australian footballers during reactive agility tasks incorporating feint and nonfeint scenarios. Accuracy was assessed as whether the subject turned in the correct direction to each stimulus. With skill groups pooled, decision accuracy at the first (or only) stimulus (decision time 1) was 94 6 7%, and it decreased to 83 6 20% for the second stimulus (decision time 2; p = 0.01; d = 0.69). However, with skill groups separated, decision accuracy was similar between groups at decision time 1 (higher 95 6 6% vs. lower 92 6 7%; p = 0.6; d = 0.42), somewhat better in the higher-standard group at decision time 2 (88 6 22% vs. 78 6 17%; p = 0.08; d =0.50). But the decrease in accuracy from decision time 1 to 2 was significant in the lower-standard group only (92 6 7% to 78 6 17%; p = 0.02; d = 1.04). However, with skill groups pooled but agility times examined exclusively in trials involving correct or incorrect decisions, incorrect decisions at decision time 1 during feint trials resulted in a shorter agility time (1.73 6 0.24 seconds vs. 2.03 6 0.39 seconds; p = 0.008; d =0.92), whereas agility time was significantly longer in feint (incorrect at decision time 2 only; 2.65 6 0.41 seconds vs. 1.97 6 0.36 seconds; p , 0.001; d = 1.76) and nonfeint trials (1.64 6 0.13 seconds vs. 1.51 6 0.10 seconds; p = 0.001; d = 1.13). Therefore, although decision-making errors typically worsen reactive agility performance, successful anticipation of a feint can produce performance improvements. Furthermore, higher-standard footballers are less susceptible to such feints, perhaps because of superior anticipation. Training to improve decision-making accuracy, particularly involving feint movements, may therefore principally benefit lesser-skilled players and should be practiced regularly. © 2013 National Strength and Conditioning Association.
- Description: C1
Reliability and validity of a novel intermittent peak running speed test for Australian football
- Authors: Mooney, Mitchell , Hunter, Jayden , O'Brien, Brendan , Berry, Jason , Young, Warren
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 25, no. 4 (2011), p. 973-979
- Full Text: false
- Reviewed:
- Description: Mooney, MG, Hunter, JR, O'Brien, BJ, Berry, JT, and Young, WB. Reliability and validity of a novel intermittent peak running speed test for Australian football. J Strength Cond Res. 25(4): 973-979, 2011-Australian football requires frequent intermittent sprinting close to peak running speed. However, tests assessing the capability to maintain intermittent peak running speed are not reported in scientific literature. Therefore, our objective is to report the reliability and validity of a novel intermittent peak running speed test. The intermittent peak running speed test required footballers to perform 10 repetitions on 25-second intervals. Each repetition required 15-m jogging, 20-m acceleration to peak speed, 10 m to sustain peak speed, 20-m deceleration, and finally a 15-m jog. Intermittent peak running speed was determined by portable global positioning system. To assess reliability, 26 footballers performed the intermittent peak running speed test on 2 occasions 3-5 days apart. Our results revealed that average peak speed had a coefficient of variation of 2.2% and an intraclass correlation of 0.91. To assess construct validity, average peak speed was compared between elite, sub-elite, and regional footballers. The average peak speed of the elite footballers (28.6 ± 1.7 km-h-1) was higher than that of the sub-elite (27.4 6 1.7 km-h -1) and regional (27 6 1.9 km-h-1) competitors (p < 0.05). Our study revealed that the intermittent peak running speed test possesses acceptable reliability and distinguishes between elite and sub-elite footballers. © 2011 National Strength and Conditioning Association.
Six minute walk distance is greater when performed in a group than alone
- Authors: Grindrod, D. , Paton, Carl , Knez, Wade , O'Brien, Brendan
- Date: 2006
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 40, no. 10 (Oct 2006), p. 876-877
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- Description: Objective: To investigate whether the distance covered in the six minute walk test was affected by walking with a group of others in comparison with performing the test alone. Methods: Eight healthy men ( mean (SD) age 21.0 (0.9) years) and eight healthy women ( mean ( SD) age 20.8 (2.0) years) performed in random order two six minute walk tests either alone or in a group of four on two separate occasions one week apart. Results: Distance covered increased significantly from a mean of 653 ( 61) m in the individual male tests to 735 (79) m in the male group tests ( p< 0.05), and 616 ( 75) m in the individual female tests to 701 ( 54) m in the female group tests ( p< 0.01). The men increased the distance walked in six minutes by 12.5% and the women by 13.7% when they performed the test as a group. Conclusion: Performing the six minute walk test in a group facilitates its execution.
- Description: C1
- Description: 2003002117
Ode to form
- Authors: Mestrom, Sanne
- Date: 2012
- Type: Text , Visual art work
- Full Text:
Reappraisal of fall-cone flow curve for soil plasticity determinations
- Authors: Soltani, Amin , O'Kelly, Brendan
- Date: 2022
- Type: Text , Journal article
- Relation: Geotechnical Testing Journal Vol. 45, no. 1 (2022), p.
- Full Text: false
- Reviewed:
- Description: Several attempts have been made to devise alternate plastic limit (PL) determination methods, targeting higher degrees of repeatability and reproducibility. Among these, empirical-type correlations linking the plasticity index (PI) to the flow index (FI) - the slope magnitude of the flow curve - seem to be gaining increased attention, particularly for the fall-cone (FC) approach, and hence demand further examination. To better understand the true potentials and limitations of this emerging practice for soil plasticity determination, this study presents a critical statistical appraisal of FI-based correlations - using a large and diverse database of 230 FC tests (for the 80 g-30° cone) - in estimating the PI (and hence the PL). It is demonstrated that the so-called "strong"correlation between the PI and FI reported in some literature, favoring the use of FI as a PI estimator, is an overlooked "statistical pitfall"originating from an over-reliance on the coefficient of determination (R2) statistic. Employing appropriate error-related statistics, it is shown that the PI predictions made by FI-based correlations are associated with high average errors of 22-33 %. Hence, such correlations, at best, can only provide a rough approximation of the actual PI (and hence PL). An attempt is also made to assess the validity of FI-based correlations in the context of soil classification using the Casagrande-style plasticity chart. The agreement level between the conventional classification approach and that performed using PI deduced from FI-based correlations was 75-80 %. This analysis, however, did not account for errors in the rolling-thread plastic limit data, maintaining a strong possibility that FI-based correlations may be suitable for routine soil classification purposes. © 2021 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
Effects of a feint on reactive agility performance
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 30, no. 8 (2012), p. 787-795
- Full Text: false
- Reviewed:
- Description: This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = -0.13-0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks. © 2012 Copyright Taylor and Francis Group, LLC.
Impact of neuromuscular fatigue on match exercise intensity and performance in elite Australian football
- Authors: Mooney, Mitchell , Cormack, Stuart , O'Brien, Brendan , Morgan, William , McGuigan, Mike
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 27, no. 1 (2013), p. 166-173
- Full Text: false
- Reviewed:
- Description: This study aimed to quantify the influence of neuromuscular fatigue (NMF) via flight time to contraction time ratio (FT:CT) obtained from a countermovement jump (CMJ) on the relationships between yo-yo intermittent recovery (level 2) test (yo-yo IR2), match exercise intensity (high-intensity running [HIR] m.min(-1) and Load.min(-1)) and Australian football (AF) performance. Thirty-seven data sets were collected from 17 different players across 22 elite AF matches. Each data set comprised an athlete's yo-yo IR2 score before the start of the season, match exercise intensity via global positioning system and on-field performance rated by coaches' votes and number of ball disposals. Each data set was categorized as normal (>92% baseline FT:CT, n = 20) or fatigued (<92% baseline FT:CT, n = 17) from a single CMJ performed 96 hours after the previous match. Moderation-mediation analysis was completed with yo-yo IR2 (independent variable), match exercise intensity (mediator), and AF performance (dependent variable) with NMF status as the conditional variable. Isolated interactions between variables were analyzed by Pearson's correlation and effect size statistics. The Yo-yo IR2 score showed an indirect influence on the number of ball disposals via HIR m.min(-1) regardless of NMF status (normal FT:CT indirect effect = 0.019, p < 0.1, reduced FT:CT indirect effect = 0.022, p < 0.1). However, the yo-yo IR2 score only influenced coaches' votes via Load.min(-1) in the nonfatigued state (normal: FT:CT indirect effect = 0.007, p <0.1, reduced: FT:CT indirect effect = -0.001, p > 0.1). In isolation, NMF status also reduces relationships between yo-yo IR2 and load.min(-1), yo-yo IR2 and coaches votes, Load.min(-1) and coaches' votes (Deltar > 0.1). Routinely testing yo-yo IR2 capacity, NMF via FT:CT and monitoring Load.min(-1) in conjunction with HIR m.min(-1) as exercise intensity measures in elite AF is recommended.
Soil moisture, organic carbon, and nitrogen content prediction with hyperspectral data using regression models
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2022
- Type: Text , Journal article
- Relation: Sensors (Basel, Switzerland) Vol. 22, no. 20 (2022), p.
- Full Text:
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- Description: Soil moisture, soil organic carbon, and nitrogen content prediction are considered significant fields of study as they are directly related to plant health and food production. Direct estimation of these soil properties with traditional methods, for example, the oven-drying technique and chemical analysis, is a time and resource-consuming approach and can predict only smaller areas. With the significant development of remote sensing and hyperspectral (HS) imaging technologies, soil moisture, carbon, and nitrogen can be estimated over vast areas. This paper presents a generalized approach to predicting three different essential soil contents using a comprehensive study of various machine learning (ML) models by considering the dimensional reduction in feature spaces. In this study, we have used three popular benchmark HS datasets captured in Germany and Sweden. The efficacy of different ML algorithms is evaluated to predict soil content, and significant improvement is obtained when a specific range of bands is selected. The performance of ML models is further improved by applying principal component analysis (PCA), a dimensional reduction method that works with an unsupervised learning method. The effect of soil temperature on soil moisture prediction is evaluated in this study, and the results show that when the soil temperature is considered with the HS band, the soil moisture prediction accuracy does not improve. However, the combined effect of band selection and feature transformation using PCA significantly enhances the prediction accuracy for soil moisture, carbon, and nitrogen content. This study represents a comprehensive analysis of a wide range of established ML regression models using data preprocessing, effective band selection, and data dimension reduction and attempt to understand which feature combinations provide the best accuracy. The outcomes of several ML models are verified with validation techniques and the best- and worst-case scenarios in terms of soil content are noted. The proposed approach outperforms existing estimation techniques.
Epigenetic changes in leukocytes after 8 weeks of resistance exercise training
- Authors: Denham, Joshua , Marques, Francine , Bruns, Emma , O'Brien, Brendan , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 116, no. 6 (2016), p. 1245-1253
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
- Full Text: false
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- Description: PURPOSE: Regular engagement in resistance exercise training elicits many health benefits including improvement to muscular strength, hypertrophy and insulin sensitivity, though the underpinning molecular mechanisms are poorly understood. The purpose of this study was to determine the influence 8 weeks of resistance exercise training has on leukocyte genome-wide DNA methylation and gene expression in healthy young men. METHODS: Eight young (21.1 +/- 2.2 years) men completed one repetition maximum (1RM) testing before completing 8 weeks of supervised, thrice-weekly resistance exercise training comprising three sets of 8-12 repetitions with a load equivalent to 80 % of 1RM. Blood samples were collected at rest before and after the 8-week training intervention. Genome-wide DNA methylation and gene expression were assessed on isolated leukocyte DNA and RNA using the 450K BeadChip and HumanHT-12 v4 Expression BeadChip (Illumina), respectively. RESULTS: Resistance exercise training significantly improved upper and lower body strength concurrently with diverse genome-wide DNA methylation and gene expression changes (p = 0. 01). DNA methylation changes occurred at multiple regions throughout the genome in context with genes and CpG islands, and in genes relating to axon guidance, diabetes and immune pathways. There were multiple genes with increased expression that were enriched for RNA processing and developmental proteins. Growth factor genes-GHRH and FGF1-showed differential methylation and mRNA expression changes after resistance training. CONCLUSIONS: Our findings indicate that resistance exercise training improves muscular strength and is associated with reprogramming of the leukocyte DNA methylome and transcriptome.
A palimpsest of abjection: Brendan Sokaluk and the burning of Churchill
- Authors: Morrissey, Belinda
- Date: 2012
- Type: Text , Journal article
- Relation: Southerly Vol. 72, no. 2 (2012), p. 100-117
- Full Text: false
- Reviewed:
- Description: On Saturday, February 7 2009, Brendan Sokaluk took a short drive down a gravel road and, according to his testimony, flicked a lit ciga rette wrapped in a paper serviette out the window, thus igniting one of the most devastating of the many fires already burning on that dreadful day.
An objective framework for determination of the air-entry value from the soil–water characteristic curve
- Authors: Soltani, Amin , Azimi, Mahdieh , Boroomandnia, Arezoo , O'Kelly, Brendan
- Date: 2021
- Type: Text , Journal article
- Relation: Results in Engineering Vol. 12, no. (2021), p.
- Full Text:
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- Description: The air-entry value (AEV) suction, marking the transition between saturated and unsaturated soil mechanics, is arguably the most important parameter interpreted from the soil–water characteristic curve (SWCC); its accurate determination being essential for the prediction of unsaturated soil properties. The AEV is commonly obtained by a subjective and time-consuming graphical construction. This micro-article proposes an objective framework, developed based on a practical mathematical translation technique, for the AEV determination. Explicit equations for the AEV are derived based on eleven well-established SWCC fitting functions, covering a wide range of functional complexities. In addition to its objective nature (providing unique interpretations of the AEV), the proposed framework complements numerical implementations of unsaturated soil constitutive models. © 2021 The Author(s)
Maximal effort interval and constant-rate running use similar amounts of oxygen
- Authors: O'Brien, Brendan , Pratt, Daniel
- Date: 2013
- Type: Text , Conference paper
- Relation: 18th Annual Congress of the European College of Sport Science
- Full Text: false
- Reviewed:
- Description: E1
The reliability of power output and performance time during simulated dynamic cycling time trials.
- Authors: Clark, Brian , Paton, Carl , O'Brien, Brendan
- Date: 2013
- Type: Text , Conference paper
- Relation: 18th Annual Congress of the European College of Sport Science
- Full Text: false
- Reviewed:
- Description: E1
Physically preparing the fast bowler in cricket: A review of the literature
- Authors: O'Brien, Brendan , Young, Warren , Feros, Simon , Bradshaw, Ryan
- Date: 2011
- Type: Text , Conference paper
- Relation: 2011 ASCA International Conference on Applied Strength and Conditioning p. 117-122
- Full Text: false
- Reviewed: