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Australian and English professional rugby players completed various physical fitness performance tests to determine differences when grouping players into three different rugby positional categories. Results found minimal differences in test scores on the basis of players' specific positions on a team, however, when players were grouped according to broader positional categories, more distinct performance and anthropometric differences appeared. (SM)

Three experiments were conducted to examine whether infants can detect the color of stationary and moving objects and maintain this discrimination over change in velocity. Subjects were 80 infants ages 8 to 20 weeks. (MP)

Drone use has increased in the last decade prompting management efforts to regulate flights near vulnerable wildlife; however, these efforts are hindered by a lack of data characterising drone‐induced wildlife disturbance. Many shorebird populations are rapidly declining and efforts to survey them can be hampered by the inaccessibility of their habitat. Drone surveys might overcome this barrier, although there is a risk that increased drone use near shorebirds may cause disturbance and exacerbate declines. We characterise drone‐induced disturbance for mixed‐species shorebird flocks to inform the management of drones near shorebirds.We conducted 240 drone approaches of mixed‐species flocks containing roosting non‐breeding shorebirds in Moreton Bay, eastern Australia. We performed approaches horizontally at varying vertical distances and recorded metrics characterising the drone, flock and environment. This enabled us to estimate the factors influencing disturbance as well as the distance of an approaching drone at which the flock is likely to take flight.We determined the drone‐induced flight initiation distance for 12 species of waterbird, including seven shorebird species. We could not approach Eastern Curlew Numenius madagascariensis at any vertical distance below the recreational drone limit of 120 m without inducing flight; however, for all other species, there was less than 20% probability that they would take flight when approached by a drone at vertical distances above 60 m. We do not recommend approaches below 30 m. We also found that flight initiation of mixed‐species flocks is largely dictated by the most sensitive species present, and that disturbance generally increases with approach velocity, drone noise/size, decreasing distance, and if the drone is obscured by trees.Policy Implications. We conclude that (i) drone use needs to be carefully regulated to ensure roosting shorebird flocks are not approached within distances that will disturb the most sensitive species likely to be present, (ii) researchers contemplating drone surveys need to carefully evaluate the risk of disturbance, especially where there are mixed‐species flocks, and (iii) that alternatives to drone surveys should be sought wherever disturbance data for the species potentially encountered are unavailable. [ABSTRACT FROM AUTHOR]

• High-resolution anisotropic model reveals complex crustal architecture in NW Australia. • NE Pilbara and W Kimberley cratons exhibit unusual subvertical deformation fabrics. • Strong basin-forming horizontal fabrics extends into the western Kimberley Craton. • Recently proposed Percival Lakes Province is divided into two anisotropic domains. • Our results indicate continent fragments are well preserved in NW Australia. The aim of this study is to investigate the crustal architecture of northwestern Australia during the Precambrian, encompassing the Pilbara Craton, the Canning Basin, and the Kimberley Craton. This region played a pivotal role in the formation of proto-Australia during the Proterozoic. However, the exact mechanisms and locations of assembly beneath the thick Phanerozoic Canning Basin remain heavily debated due to insufficient detailed regional crustal structural information. By developing a radially anisotropic shear wave velocity model of the regional crust, we directly visualize the deformation fabrics of the entire crust, which can be correlated with seismic anisotropy. Through spatial correlation with surface geology, we deduce potential ancient deformation scenarios unique to each crustal domain. Our new anisotropy model, characterized by rapidly changing and spatially distinct anisotropy patterns, reveals several significant findings. Subvertical deformation is associated with the northeast margin of the exposed Pilbara Craton and the western margin of the Kimberley basement, indicating collisional deformation in these Archean crustal segments. Strong horizontal deformation is inferred east of the Fenton fault in the Canning Basin, aligning with the multiple stages of extensional processes that formed the basin. This extensional signal extends into the west Lamboo Province of the Kimberley Craton. In the western Canning Basin, the Percival Lake Province, identified by its distinctive seismic, age, and isotopic characteristics in recent studies, lacks a clear extensional signal. Instead, two sub-crustal domains are favored, exhibiting opposing deformation fabrics. The newly revealed regional anisotropic architecture provides insights into the complex amalgamation processes between the Pilbara and Kimberley Cratons, as well as significant basin deformations following cratonization. Our study demonstrates that radial anisotropy offers direct lithospheric constraints, enhancing our understanding of the formation and evolution of Precambrian continents in concealed regions. [ABSTRACT FROM AUTHOR]

The study examined the utility of surrogate measures of athletic performance to determine locomotor qualities (maximal aerobic velocity and peak velocity) in elite Australian Football (AF). 29 professional AF players undertook aerobic fitness (3km time-trial [TT] and 30–15 Intermittent Fitness Test [30–15 IFT]) and peak velocity (PV; 50 m maximal sprints using 10Hz GPS) assessments in pre-season. Characteristics of TT performance (mean velocity, 500m and 1km splits) were compared with a surrogate for maximal aerobic velocity (MAV; 80% of 30–15 IFT final velocity). PVs derived from sprint tests were compared to those attained in AF matches (10 Hz GPS). Higher Pearson correlations were observed between MAV versus the fastest 500m (r = 0.74) and 1km (r = 0.75) of the 3km TT, but they were not superior to mean velocity (r = 0.72; p ≥ 0.30) which also demonstrated the lowest bias (p ≤ 0.01) and equivalent typical errors (0.16–0.17 m.s−1). Peak velocity was higher across match observations (0.28, CI: ± 0.17 m.s −1, p = 0.017) versus sprint tests. There was no impact of playing position on the determination of locomotor qualities using surrogate measures of locomotor qualities. Locomotor qualities can be determined practically using 10Hz GPS devices during 3km time-trials and competitive matches (assuming appropriate signal quality), without additional fitness assessments. [ABSTRACT FROM AUTHOR]

While the variations of tidal range are large and fairly well known across Australia (less than 1 m near Perth but more than 14 m in King Sound), the properties of the tidal currents are not. We describe a new regional model of Australian tides and assess it against a validation dataset comprising tidal height and velocity constituents at 615 tide gauge sites and 95 current meter sites. The model is a barotropic implementation of COMPAS, an unstructured-grid primitive-equation model that is forced at the open boundaries by TPXO9v1. The Mean Absolute value of the Error (MAE) of the modelled M2 height amplitude is 9.3 cm, or 13 % of the 73 cm mean observed amplitude. The MAE of phase (11°), however, is significant, so the M2 Mean Magnitude of Vector Error (MMVE, 20 cm) is significantly greater. Results for 5 other major constituents are similar. We conclude that while the model has skill at height in all regions, there is definitely room for improvement (especially at some specific locations) before harmonic predictions based on observations are rendered obsolete. For the M2 major-axis velocity amplitude, the MAE across the 95 current meter sites, where the observed amplitude ranges from 0.1 cm s-1 to 144 cm s-1, is 6.5 cm s-1, or 20 % of the 31.7 cm s-1 observed mean. This nationwide average result is not much greater than the equivalent for height, but it conceals a larger regional variation. Relative errors on the narrow shelves of NSW and Western Australia exceed 100 %, but tidal currents are weak and negligible there compared to non-tidal currents. We show that the model has predictive value for much of the 79 % of Australia's shelf seas where tides are a major component of the total velocity variability. In descending order this includes the Bass Strait, Kimberley to Arnhem Land and Southern Great Barrier Reef regions. There is limited evidence the model is also valuable for currents in other regions across northern Australia. We plan to commence publishing unofficial tidal current predictions for chosen regions in the near future, based on both the limited number of observations, and the COMPAS model. [ABSTRACT FROM AUTHOR]

Watson, P.J., 2020. Updated mean sea-level analysis: Australia. Journal of Coastal Research, 36(5), 915–931. Coconut Creek (Florida), ISSN 0749-0208. As an island nation with 60,000 km of open coastline and extensive margins of increasingly urbanised intertidal estuarine foreshores, Australia is critically exposed to the global threat posed by rising sea levels into the future. This study provides a contemporary assessment of sea-level rise around Australia to the end of 2018, based on all available tide gauge records and satellite altimetry. The study provides the first national assessment of vertical land motion (VLM) around the coast, identifying margins more prevalent to subsidence, which in turn exacerbate the localised effects of a rising global mean sea level. These areas include coastlines between Townsville and Coffs Harbour, Burnie to Port Pirie, and Fremantle to Wyndham. State-of-the-art time-series analysis techniques applied to all high-quality tide gauge records exceeding 75 years in length (four sites) enabled improved insights into the temporal resolution of current rates of rise and accelerations in mean sea level around Australia than were previously available. Averaged across these four records in 2018, approximately 40% of the "relative" velocity observed (∼2.2 ± 1.8 mm/y, 95% confidence limit [CL]) is attributable to VLM. When corrected for VLM, only the Fort Denison site exhibits "geocentric" mean sea-level velocity in 2018 exceeding 2 mm/y. The average geocentric velocity across all four sites in 2018 equates to 1.3 ± 2.0 mm/y (95% CL). Interestingly, each long record exhibits similar temporal characteristics, whereby a low point in the velocity time series occurs sometime in the period from 1970 to 1990, after which velocity increases over time to a peak occurring sometime after ca. 2010, suggesting the presence of a small acceleration (albeit not statistically different to zero at the 95% CL) in the record. [ABSTRACT FROM AUTHOR]

Benthic algae are a major source of carbon supporting aquatic food webs in northern Australia, but little is known about the factors that regulate algal production. We surveyed benthic algal biomass in mainstem habitats of an unregulated sandy tropical river (the Fitzroy River) during a base-flow period. We used predictive models to reveal the physical and chemical parameters controlling algal biomass in mainstem habitats. We found that water velocity was an important driver—algal biomass was lower at higher water velocities. Subsurface flow was also influential—algal biomass increased in locations where groundwater upwelling occurred, as evident by a positive relationship between algal biomass and elevated radon and ammonium concentrations. In this sand-bed river, it is likely that high water velocity destabilises the sandy substrate reducing the establishment of algal biofilms. However, where water velocity is low enough for algal establishment, groundwater upwelling likely promotes algal growth by delivering limiting resources and/or creating stable conditions that promote algal production. The importance of surface and subsurface-flow conditions to benthic algal biomass means that any modification to the Fitzroy River catchment that alters dry-season longitudinal flows (via river regulation) or groundwater levels (via groundwater extraction) may directly influence river algal production. [ABSTRACT FROM AUTHOR]

This study assessed the validity and reliability of the 1080 Quantum (1080Q) during the bench press exercise. Twenty-seven resistance-trained men (28 6 4 years; body mass 88.9 6 12.8 kg; 1 repetition maximum [1RM] bench press 94.8 6 10.7 kg) completed 2 test-retest sessions, separated by 1 week. In each session, subjects performed single repetitions at 30, 40, 50, 60, 70, and 80% of their bench press 1RM. Mean velocity (Vmean), peak velocity (Vpeak), mean force (Fmean), peak force (Fpeak), mean power (Pmean), and peak power (Ppeak) were simultaneously assessed using the 1080Q Synchro and a linear position transducer (GymAware; Kinetic Performance Technology, Canberra, Australia). The overall performance of the 1080Q was both valid (r = 0.94-1.00) and reliable (coefficient of variation [CV] = 1.7-8.0%, intraclass correlation coefficient [ICC]50.90-1.00) for all measures, although both fixed and systematic biases were present. When assessed at each of the relative loads, the 1080Q remained valid for all measures apart from Fmean at 30% 1RM (r = 0.78) and Fpeak at 70 (r = 0.81) and 80% (r = 0.57) 1RM. The 1080Q also demonstrated excellent reliability at all relative loads apart from the heaviest, where Vmean (CV = 11.0%, ICC = 0.69), Pmean (CV = 11.4%, ICC = 0.65), and Ppeak (CV = 10.2%, ICC = 0.79) reliability was reduced. These data indicate that athletes and strength and conditioning coaches can confidently use the 1080Q to monitor training progression; however, caution should be taken when assessing performance measures at the either end of the load spectrum. [ABSTRACT FROM AUTHOR]

Using 18 days of field observations, we investigate the diurnal (D1) frequency wave dynamics on the Tasmanian eastern continental shelf. At this latitude, the D1 frequency is subinertial and separable from the highly energetic near-inertial motion. We use a linear coastal-trapped wave (CTW) solution with the observed background current, stratification, and shelf bathymetry to determine the modal structure of the first three resonant CTWs. We associate the observed D1 velocity with a superimposed mode-zero and mode-one CTW, with mode one dominating mode zero. Both the observed and mode-one D1 velocity was intensified near the thermocline, with stronger velocities occurring when the thermocline stratification was stronger and/or the thermocline was deeper (up to the shelfbreak depth). The CTW modal structure and amplitude varied with the background stratification and alongshore current, with no spring–neap relationship evident for the observed 18 days. Within the surface and bottom Ekman layers on the shelf, the observed velocity phase changed in the cross-shelf and/or vertical directions, inconsistent with an alongshore propagating CTW. In the near-surface and near-bottom regions, the linear CTW solution also did not match the observed velocity, particularly within the bottom Ekman layer. Boundary layer processes were likely causing this observed inconsistency with linear CTW theory. As linear CTW solutions have an idealized representation of boundary dynamics, they should be cautiously applied on the shelf. [ABSTRACT FROM AUTHOR]

Purpose: Stroke rate (SR) has not been considered in previous research examining the relative roles of the limbs in front-crawl performance. This study compared velocity, aerobic power ([Formula: see text]) and metabolic cost (C) between whole body (WB) and arms only (AO) front-crawl swimming across various intensities while controlling SR.Methods: Twenty Australian national swimmers performed six 200 m front-crawl efforts under two conditions: (1) WB swimming and, (2) AO swimming. Participants completed the 200 m trials under three SR conditions: "low" (22-26 stroke-cycles min(-1)), "moderate" (30-34 stroke-cycles min(-1) and "high" (38-42 stroke-cycles min(-1)). [Formula: see text] was continuously measured, with C, velocity, SR, and kick rate calculated for each effort.Results: Regardless of the SR condition and sex, AO velocity was consistently lower than WB velocity by ~11.0 % (p < 0.01). AO [Formula: see text] was lower than WB [Formula: see text] at all SR conditions for females (p < 0.01) and at the "high" SR for males (p < 0.01). C did not differ between WB and AO at any SR for both sexes (p > 0.01). When C was expressed as a function of velocity, WB and AO regression equations differed for males (p = 0.01) but not for females (p = 0.087). Kick rate increased as SR increased (p < 0.01), though the kick-to-stroke rate ratio remained constant.Conclusion: Elite swimmers gain ~11 % in velocity from their kick and, when used in conjunction with the arm stroke at the swimmers' preferred frequency, the metabolic cost of WB and AO swimming is the same. Coaches should consider these results when prescribing AO sets if their intention is to reduce the metabolic load. [ABSTRACT FROM AUTHOR]

This study aimed to determine if starting with the feet above the water (FAW) in male backstroke swimming resulted in faster start times (15-m time) than when the feet were underwater (FUW). It was hypothesised that setting higher on the wall would generate increased horizontal force and velocity, resulting in quicker starts. Twelve high-level male backstrokers performed three trials of the FAW and FUW techniques. A biomechanical swimming testing system comprising one force plate (1,000 Hz), four lateral-view (100 Hz), and five overhead (50 Hz) video cameras captured the swimmers' performance. Data for each participant's fastest trial for each technique were collated, grouped, and statistically analysed. Analysis included Wilcoxon, Spearman Rho correlation, and regression analysis. Wilcoxon results revealed a significantly faster start time for the FAW technique (p < 0.01). Peak horizontal force was significantly smaller for FAW (p = 0.02), while take-off horizontal velocity was significantly greater (p = 0.01). Regression analysis indicated take-off horizontal velocity to be a good predictor of start time for both techniques, and the horizontal displacement of the centre of mass for the FAW start. [ABSTRACT FROM PUBLISHER]

This study provides information on habitat selection by the threatened Murray cod Maccullochella peelii peelii at two spatial scales in the Ovens and Murray Rivers in south-eastern Australia. Both adult (>450 mm total length, LT) and age 0 year (<150 mm LT) M. p. peelii selected macro and microhabitats based on structural variables. At the macrohabitat scale, adults selected channel habitats in the river, floodplain channels at high floods and within Lake Mulwala, whereas the floodplain proper was avoided. Adult and age 0 year fish selected similar microhabitats regardless of site or hydrologic conditions, and selection was primarily influenced by the presence of higher loadings of structural woody habitat, higherc.v. in depth, more overhanging vegetation, shallower comparative depths and lower water velocities, closer to the bank. Age 0 year M. p. peelii appeared to select shallower habitats with greater amounts of structural woody habitat, closer to the river bank than adult fish. [ABSTRACT FROM AUTHOR]

A tidal bore impacts significantly on the estuarine ecosystem, although little is known on the flow field, mixing and sediment motion beneath tidal bores. In the absence of detailed systematic field measurements, a quasi-steady flow analogy was applied to investigate undular tidal bores with inflow Froude numbers between 1.25 and 1.6. Experimental results indicated that rapid flow redistributions occur beneath the free-surface undulations, with significant variations in bed shear stress between wave crests and troughs. Dynamic similarity was used to predict detailed flow characteristics of undular tidal bores. The effects of periodic loading on river sediments, scour of river bed and flow mixing behind the bore are discussed. A better understanding of these processes will contribute to better management practices in tidal bore affected rivers, including the Styx and Daly rivers in tropical Australia. [ABSTRACT FROM AUTHOR]

The Whicher Range field of the Perth Basin includes tight sandstones of the late Permian Willespie Formation with substantial gas reserves. Reservoir properties of these sandstones, in addition to the influence of initial depositional texture, have been significantly modified by diagenesis, reflecting in fluid flow and production behavior in the field. In this study, with the target of unraveling the reservoir heterogeneity related to pore types, sandstone rock types were investigated in detail by integrating core data and velocity deviation log derived from the Wyllie equation. The results show that the variations in this parameter are intimately related to pore system properties of tight sandstone facies in the field. Estimation of velocity deviation from seismic data resulted in the identification of three main rock types (RT-1, RT-2, and RT-3) with different pore characteristics. Evaluation of the identified rock types showed that RT3, which is correlated with medium to coarse and gravely sandstones, significantly contributes to the high production reservoir zones. This rock type with isolated and traces of intergranular pore types is distributed in upper parts of the reservoir interval mainly along wells WR1 and WR4. The methodology described in this study is well working with geological, petrophysical, and seismic data. It can be employed as a prototype case study in reservoir characterization of tight sandstone reservoirs. • Complexity in pore systems of tight sandstones is unraveled by velocity deviation log. • Variations in velocity deviation log is consistent with variability in pore types. • Integration of VDL and AI represents the most promising reservoir zones. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the influence of chronological age and maturation status on sprint acceleration characteristics in junior Australian football (AF) players. Biological maturity of 109 subjects was assessed and subjects were grouped according to predicted years from peak height velocity (PHV) (pre-, mid-, and post-PHV) and chronological age (13 years, 14 years, and 15 years). A one-way multivariate analysis of variance and magnitude-based decisions were used to determine between-group differences. Instantaneous velocity was measured during two maximal 30m sprints via radar gun with the velocity-time data used to derive the force, velocity, and power characteristics. Chronologically, the greatest differences were observed between the 13 and 14 year old groups with the latter group producing likely  greater relative maximum power (P max ) (ES[effect size]=0.44) and theoretical maximal velocity (V 0 ) (ES=0.49). The post-PHV group  likely  demonstrated a greater ability to apply force at faster velocity (V 0 ; ES=0.59) and orient the force in a horizontal direction (D rf %; ES=-0.49) than the mid-PHV group. No differences in relative theoretical maximal force (F 0 ) were observed between groups. Considering the findings, practitioners should aim to improve relative lower limb strength through heavy sled push or sled pulls and traditional strength training exercises to improve relative F 0 .