T cell antigen receptor (TCR) and coreceptor ligation is thought to initiate signal transduction by inducing activation of the kinase Lck.Here we showed that catalytically active Lck was present in unstimulated naive cells thymocytes readily detectable these lymphoid organs.In up ∼40% total constitutively activated, part which also phosphorylated on C-terminal inhibitory site.Formation activated independent TCR coreceptors but required catalytic activity its maintenance relied monitoring...

The aim of the present study was to examine effects movement intensity and path linearity on global positioning system (GPS) distance validity reliability. One participant wore eight 1-Hz GPS receivers while walking, jogging, running, sprinting over linear non-linear 200-m courses. Five trials were performed at each course. receiver excluded from analysis due errors during data collection. results seven showed mean (± s) percent bias values course 205.8 ± 2.4 m (2.8%), 201.8 2.8 (0.8%),...

To investigate temporal variation in running intensity across and within halves evaluate the agreement between match-analysis indices used to identify fluctuations rugby sevens.Data from a 15-Hz global positioning system (GPS) were collected 12 elite sevens players during IRB World Sevens Series (N = 21 full games). Kinematic (eg, relative distance [RD]) energetic metabolic power [MP]) determined velocity-time curves between-halves variations. Mean MP RD peak 2-minute periods of play....

Abstract Denham, J, Scott-Hamilton, Hagstrom, AD, and Gray, AJ. Cycling power outputs predict functional threshold maximum oxygen uptake. J Strength Cond Res 34(12): 3489–3497, 2020—Functional (FTP) has emerged as a correlate of lactate is commonly assessed by recreational professional cyclists for tailored exercise programing. To identify whether results from traditional aerobic anaerobic cycling tests could FTP V̇ o 2 max, we analyzed the association between estimated FTP, uptake (V̇ max...

The aims of this study were to i) compare a foot-mounted inertial system (PlayerMaker™) three commercially available Global Positioning Systems (GPS) for measurement velocity-based metrics during team sport movements and ii) evaluate the inter-unit reliability PlayerMaker™. Twelve soccer players completed simulation, whilst wearing PlayerMaker™ GPS (GPS#1, #2 #3). A sub-sample (n = 7) also wore two systems concurrently. measured higher (p < 0.05) total distance (518 ± 15 m) compared GPS#1...

The purpose of this study was to apply a time-motion model estimate and describe the energy expenditure metabolic power demands playing positions in elite rugby league match-play, utilizing Global Positioning System (GPS) devices. 18 players participated study. Players' positional groups included: outside backs (n=59 files, n=4 players), adjustables (n=74 wide-running (n=104 n=7 players) hit-up forwards (n=36 n=3 players). Outside expended greatest total (40.1±5.0 kJ·kg(-1)) per match,...

Abstract Small non-coding RNAs, such as microRNAs (miRNAs), have emerged powerful post-transcriptional regulators of gene expression that play important roles in many developmental and biological processes. In this study, we assessed the abundance circulating for skeletal muscle heart adaptations to exercise (miR-1, miR-133a, miR-133b miR-486), following acute short-term sprint interval training (SIT). Twenty-eight individuals completed four all-out efforts on a cycle ergometer, donated...

Waldron, M, Gray, A, Worsfold, P, and Twist, C. The reliability of functional movement screening in-season changes in physical function performance among elite rugby league players. J Strength Cond Res 30(4): 910–918, 2016—This study aimed to (a) assess the (FMS) protocol (b) establish both FMS tests throughout a season. components (12 total) was assessed through nonparametric statistical approach, based on 2 trials, separated by 1 week. Score FMS, strength (3 repetition maximum full squat,...

Cummins, CJ, Gray, AJ, Shorter, KA, Halaki, M, and Orr, R. Energetic demands of interchange full-match rugby league players. J Strength Cond Res 32(12): 3456-3464, 2018-The purpose this study was to describe compare the metabolic for players in relation positional groups. Eighteen elite were recruited. A time-motion model used estimate energy expenditure match-play using Global Positioning System (GPS) technology. This approach uses players' GPS velocity-time curves examine running velocity....

Small non-coding RNAs (ncRNAs) are emerging as important molecules for normal biological processes and deregulated in disease. Exercise training is a powerful therapeutic strategy that prevents cardiometabolic disease improves cardiorespiratory fitness performance. Despite the known systemic health benefits of exercise training, underlying molecular mechanisms incompletely understood. Recent evidence suggests role epigenetic mechanisms, such microRNAs, but whether other small ncRNAs...

An energy-based approach to quantifying the mechanical demands of overground, constant velocity and/or intermittent running patterns is presented. Total work done (Wtotal) determined from sum four sub components: accelerate centre mass horizontally (Whor), vertically (Wvert), overcome air resistance (Wair) and swing limbs (Wlimbs). These components are established relationships between kinematics; application work-energy theorem. The model was applied (2–9 m/s), a hard acceleration event...

Waldron, M, Gray, A, Furlan, N, and Murphy, A. Predicting the sprint performance of adolescent track cyclists using 3-minute all-out test. J Strength Cond Res 30(8): 2299-2306, 2016-This study aimed to predict 500-m time trial (TT) 2,000-m pursuit speed (age range = 13-15 years) mechanical parameters derived from a critical power (CP) test anthropometric variables. Ten well-trained competitive were assessed for body composition, mass, stature, frontal surface area (FSA), as well completing...

We investigated the effects of familiarization on reliability gross efficiency (GE) and lower-limb electromyography (EMG-rms) adults adolescents. also evaluated relationship between inter-test differences in GE EMG-rms. Nine adult nine adolescent cyclists performed three 10 min cycling tests at 50% peak power output, separated by 48 h. Forty-five minutes visits were 24 h after each test. No found across for cyclists' or EMG-rms, with Coefficient Variation (CV%) ranging from 2.6 to 2.9% 4.3...

Greater trochanteric bursitis is a relatively common presentation at hip clinics. It presents with pain around the greater trochanter. Diagnosis usually made on clinical grounds when other and spinal pathologies are ruled out there tenderness present over region. Rheumatoid arthritis (1), athletic injury (2), total arthroplasty (3) idiopathic disease (4) some of known causes bursitis. Treatment mainly non-operative expectant; however various operative interventions have been described in...

Gray, A, Price, M, and Jenkins, D. Predicting temporal gait kinematics from running velocity. J Strength Cond Res 35(9): 2379-2382, 2021-The manner in which stride frequency (f) changes response to velocity (v) is well established. Notably, as increases, duty factor (d, the % of stance) decreases, concomitantly with higher frequencies. Mathematical descriptions this relationship do not exist, limiting our ability reasonably predict gait-based metrics wearable technologies. Therefore, purpose...

Abstract Purpose We compared a new locomotor-specific model to track the expenditure and reconstitution of work done above critical power ( W´ ) balance BAL by modelling flat over-ground during exhaustive intermittent running. Method Nine male participants completed ramp test, 3-min all-out test 30–15 fitness (30–15 IFT), performed severe-intensity constant work-rate trial S CWR at maximum oxygen uptake velocity vV̇ O 2max ). Four trials followed: 60-s + 50% Δ 1 (Δ = − [ V Crit ])...

Physiological models for estimating internal mechanical power (IP) generally share a common basis: the sum of IP and external (EP) is equal to total power, as represented by net VO2.  While biomechanical perspective argues against this simple summation, physiological serve valuable purpose because they account flow energy through system.  Despite their foundation, estimates using various have not been consistent.  Two pre-existing that use approach, well variations them body mass-cadence...

To assess the ecological validity of Rugby Sevens Simulation Protocol (R7SP) and to evaluate its interday reliability.Ten male participants (20 ± 2 y, 74 11 kg) completed trials R7SP, separated by 7 d. The R7SP comprised typical running collision activities, based on data recorded during international rugby sevens match play. Heart rate (HR) was monitored continuously participants' movements were through a 20-Hz global positioning system unit. Blood lactate rating perceived exertion...

INTRODUCTION: Repeated ischemic preconditioning (IPC) can improve muscle and pulmonary oxygen on-kinetics, blood flow, exercise efficiency, but these effects have not been investigated in severe hypoxia. The aim of the current study was to evaluate 7 d IPC on resting exercising cardio-pulmonary responses hypoxia.METHODS: A total 14 subjects received either: 1) repeated lower-limb occlusion (4 × 5 min, 217 ± 30 mmHg) at limb occlusive pressure or SHAM 20 mmHg). Subjects were tested for...