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Ascertaining how racket orientation angle differences at ball-impact influence the accuracy of different squash strokes could assist player skill development and possibly reduce the number of unforced errors hit within a match. The purpose of this study was to identify differences in racket orientation angles of accurate and inaccurate forehand and backhand drive, volley and drop shots. A magnetic-inertial measurement unit embedded in a racket output orientation angles of twelve male junior players, with five accurate and five inaccurate shots per player per stroke analysed. Paired samples t-tests revealed that inaccurate backhand drop shots exhibited significantly (p < 0.05) less racket roll angle (racket face less open) at impact than accurate shots, indicating this parameter was a determining factor in the accuracy of this stroke. Racket orientation angle differences between accurate and inaccurate shots of the remaining strokes were too small to be used to distinguish shot accuracy. There was significantly greater variability in racket orientation angles during inaccurate forehand drop and backhand drive shots compared to accurate shots. These findings demonstrate how racket orientation angle differences at ball-impact can influence the accuracy of shots and highlights the need for consistent racket orientations to allow for an accurate shot. [ABSTRACT FROM AUTHOR]

The torso muscles play important roles in longitudinal rotation between the upper and lower torso on land but demands on these muscles at different swimming speeds and their role in torso twist in front crawl remains unclear. We aimed to compare torso muscle activity at different front crawl speeds and to assess the relationships between torso muscle activity and torso twist. Three-dimensional kinematics and torso muscle EMG data were collected from 15 male swimmers during middle-distance and sprint front crawl. Internal oblique, external oblique, and rectus abdominis, but not erector spinae, activities were greater at sprint than middle-distance pace. Sprint swimmers are likely to benefit from focusing training on the abdominal muscles. Cross-correlation peak coefficients between muscle activity and torso twist occurred with 517–775 and 400–600 ms lag at middle-distance and sprint paces (respectively). These lags are beyond the torso muscle electromechanical delay (~220 ms) and are too long for these muscles to produce movement changes. Further, peak coefficients coincided with both positive and negative shifts, indicating that muscle activity did not always precede kinematic changes. The torso muscles are therefore likely to play a greater role in maintaining stability and controlling posture in front crawl than producing torso twist. [ABSTRACT FROM AUTHOR]

Springboard diving training is often focused upon skill repetition to establish movement accuracy, stability and consistency. Within-participant study designs provide the ability to understand how individuals create these skills under different movement strategies. IMUs measured angular velocity time-series data of two athletes performing multiple repetitions of forward 3½ somersault pike dives. Functional Principal Component Analyses (fPCA) were performed to examine individual movement structure and variability. The first five fPC's represented approximately 98% of the variability in angular velocity for both divers. To determine the relative importance of angular velocity variability, Pearson's correlations for pairwise comparisons were used to assess the relationship between fPC scores and discrete performance variables during takeoff, flight and entry. Divers exhibited a different number and types of significant correlations (International = 4; National = 11). Only one correlation was common for both divers; higher angular velocity during Initial Flight and/or Somersault phases resulted in more vertically aligned entry posture (International: fPC1 r = −0.761, p < 0.05; National: fPC3 r = −0.796, p < 0.01). Findings identify individualised angular velocity time-series structure and kinematic performance variables (International = angular; National = linear) that can be used by coaching/sport science teams to optimisation performance success. [ABSTRACT FROM AUTHOR]

Midterm student feedback is a common process in post-secondary institutions that can lead to enhanced teaching practices and thereby potentially to higher ratings of instructional skills in summative course evaluations. At McMaster University, midterm student feedback is called a 'Course Refinement' and includes consultation with educational developers. As part of a multiphase study investigating teachers' perceptions of the Course Refinement process and its impact, this analysis presents effective attributes of the process as an adaptation of Chickering and Gamson's well-known 'seven principles for good practice in undergraduate education', as our findings align with their work. To our knowledge, this marks the first educational development adaptation of the 'seven principles'. [ABSTRACT FROM AUTHOR]

Knowledge of the kinematic differences that separate highly skilled and less-skilled squash players could assist the progression of talent development. This study compared trunk, upper-limb and racket kinematics between two groups of nine highly skilled and less-skilled male athletes for forehand drive, volley and drop strokes. A 15-camera motion analysis system recorded three-dimensional trajectories, with five shots analysed per participant per stroke. The highly skilled group had significantly (p < 0.05) larger forearm pronation/supination range-of-motion and wrist extension angles at impact than the less-skilled. The less-skilled group had a significantly more "open" racket face and slower racket velocities at impact than the highly skilled. Rates of shoulder internal rotation, forearm pronation, elbow extension and wrist flexion at impact were greater in the drive stroke than in the other strokes. The position of the racket at impact in the volley was significantly more anterior to the shoulder than in the other strokes, with a smaller trunk rotation angular velocity. Players used less shoulder internal/external rotation, forearm pronation/supination, elbow and wrist flexion/extension ranges-of-motions and angular velocities at impact in the drop stroke than in the other strokes. These findings provide useful insights into the technical differences that separate highly skilled from less-skilled players and provide a kinematic distinction between stroke types. [ABSTRACT FROM AUTHOR]

To maintain the accuracy of squash shots under varying conditions, such as the oncoming ball's velocity and trajectory, players must adjust their technique. Although differences in technique between skilled and less-skilled players have been studied, it is not yet understood how players vary their technique in a functional manner to maintain accuracy under varying conditions. This study compared 3-dimensional joint and racket kinematics and their variability between accurate and inaccurate squash forehand drives of 9 highly skilled and 9 less-skilled male athletes. During inaccurate shots, less-skilled players hit the ball with a more open racket, demonstrating a difference in this task-relevant parameter. No joint kinematic differences were found for accuracy for either group. Coordinated joint rotations at the elbow and wrist both displayed a "zeroing-in" effect, whereby movement variability was reduced from the initiation of propulsive joint rotation to a higher consistency at ball-impact; potentially highlighting the "functionality" of the variability prior to the impact that enabled consistent task-relevant parameters (racket orientation and velocity) under varying conditions. Further, highly skilled players demonstrated greater consistency of task-relevant parameters at impact than less-skilled players. These findings highlight the superior ability of highly skilled players to adjust their technique to achieve consistent task-relevant parameters and a successful shot. [ABSTRACT FROM AUTHOR]

Task-specific auditory training can improve sensorimotor processing times of the auditory reaction time (RT). The majority of competitive swimmers do not conduct habitual start training with the electronic horn used to commence a race. We examined the effect of four week dive training interventions on RT and block time (BT) of 10 male adolescent swimmers (age 14.0 ± 1.4 years): dive training with auditory components (speaker and electronic horn) (n = 5) and dive training without auditory components (n = 5). Auditory stimulus dive training significantly reduced swimming start RT, compared with dive training without auditory components (p < 0.01), with a group mean RT reduction of 13 ± 9 ms. Four of the five swimmers that received auditory stimulus training showed medium to large effect size reductions in RT (d = 0.74; 1.32; 1.40; 1.81). No significant changes to swimmers' BTs were evident in either dive training intervention. The adolescent swimmers' results were compared against six male elite swimmers (age 19.8 ± 1.0 years). The elite swimmers had significantly shorter BTs (p < 0.05) but no significant difference in RTs. Auditory stimulus dive training should be explored further as a mechanism for improving swimming start performance in elite swimmers who have pre-established optimal BTs. [ABSTRACT FROM AUTHOR]

Based on technological and analytical advances, the capability to more accurately and finitely examine biomechanical and skill characteristics of movement has improved. The purpose of this study was to use Inertial Measurement Units (IMUs) and Functional Principal Components Analysis (fPCA) to examine the role of movement variability (assessed via angular velocity), on 2 divers (1 international level; 1 national) performing the forward 3½ pike somersault dive. Analysis of angular velocity curves during ive-flight identified 5 fPCs, accounting for 96.5% of movement variability. The national diver's scatter plots and standard deviation of fPC scores illustrated larger magnitudes of angular velocity variability across dive flight. For fPC1 and fPC3, magnitudes of SD variability were 282.6 and 201.5, respectively. The international diver illustrated more consistent angular velocity profiles, with clustering of fPCs scores (e.g., fPC1 & 3 = SD's of 75.2 & 68.0). To account for lower variability in the international diver, the ability to better coordinate movement sequences and functionally utilise feedback in response to initiation of the somersault position is highlighted. Overall, findings highlight how both IMUs and fPCA can more holistically and finitely examine the biomechanical and skill characteristics of movement sequences with the capability to inform athlete development. [ABSTRACT FROM AUTHOR]

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics. [ABSTRACT FROM AUTHOR]

The techniques of spin bowling in cricket have been largely formulated from the collective intuitions of past players. A standard model of bowling technique has been generally prescribed for both off-spin and leg-spin bowlers, but there has been no biomechanics research to validate this approach. This study measured 20 Type-2 off-spin and 15 Type-2 leg-spin bowlers using a 3D Cortex motion analysis system. Correlation coefficients between segmental kinematic variables and spin rate in the off-spin and leg-spin bowlers revealed that off-spin bowling was associated with an earlier movement time of the thorax, whereas leg-spin bowling was associated with a greater magnitude and earlier movement time of pelvis rotation, as well as a greater magnitude of pelvis-shoulder separation movement. The maximum velocity of rear hip flexion differentiated between both groups of bowlers. The GLM suggested that for off-spinners, rear hip flexion velocity significantly explained the variance in spin rate (subject to sequential timing constraints), while for leg-spinners, the time of maximum rear hip flexion and maximum arm circumduction velocity significantly explained variance in spin rate. This study supports the notion that off-spinners and leg-spinners have significant differences in their joint kinematics, and should not be coached under a one-size-fits-all technical model. [ABSTRACT FROM AUTHOR]

Active drag force in swimming can be calculated from a function of five different variables: swim velocity, tow velocity, belt force, power output and exponent of velocity. The accuracy of the drag force value is dependent on the accuracy of each variable, and on the contribution of each variable to drag estimation. To calculate uncertainty in drag value, first the derivatives of the active drag equation with respect to each variable were obtained. Second, these were multiplied by the uncertainty of that variable. Twelve national age and open level swimmers were recruited to complete four free swimming and five active drag trials. The uncertainties for the free and the tow swim velocities, and for the belt force, contributed approximately 5–6% and 2–3% error, respectively, in calculation of drag. The result of the uncertainty of the velocity exponent (1.8–2.6) indicated a contribution of about 6% error in active drag. The contribution of unequal power output showed that if a power changed 7.5% between conditions, it would lead to about 30% error in calculated drag. Consequently, if a swimmer did not maintain constant power output between conditions, there would be substantial errors in the calculation of active drag. [ABSTRACT FROM AUTHOR]

Inertial Measurement Units (IMUs) may offer an ecologically valid, reliable, and practical method for biomechanical performance analysis. With such potential in mind, Part 1 of this study examined the accuracy of IMUs gyroscopes with an optical system (Cortex 3.3). A calibration formula standardised the IMUs angular velocity output with the optical system. The percentage differences between the two measures = 0.5% (p < 0.05), suggest IMU’s efficacy for application. In Part 2, the aim was to examine and understand how dive flight angular velocity time series plots change and increase according to dive degree of difficulty. With IMUs attached to three competitive divers performing forward somersault dives, dive flight kinematics were assessed. Biomechanically, a 4½ tuck somersault dive differed to lower degree of difficulty dives in terms of: (1) a rotational delay immediately after takeoff (to gain greater vertical translation); (2) increased total time of flight; (3) greater muscle effort to resist increased centrifugal forces produced by the increased angular velocity (1,090 °/s); and (4) greater eccentric control during deceleration allow a safe and vertical entry into the water. IMUs can be effectively utilised and integrated into contexts such as springboard diving for performance analysis and optimisation purposes. [ABSTRACT FROM AUTHOR]

The reliability of active drag values was examined using a method that compared free swim speed with measurements taken by towing swimmers slightly faster than their maximum swim speed, while allowing their intra-stroke speed fluctuations. Twelve national age and open level swimmers were tested on two alternate days (Day 1 and Day 2). All participants completed four maximum swim speed, three passive drag and five active drag trials on each of the days. The reliability was determined using within-participant intra-class correlation coefficients (ICC) within each day and between the days. The ICCs for Day 1 and Day 2 were 0.82 and 0.85, respectively, while the comparison of the mean active drag values between days was 0.93. The data showed that the assisted towing method (ATM) with fluctuating speed was only moderately reliable within a single test. However, this method was more reliable when using the average value of active drag from both days (ICC = 0.93). This study identified that the ATM method with fluctuating speed had moderate reliability within-participant trials on values in a single day but high reliability for the average active drag values across different days. [ABSTRACT FROM AUTHOR]

Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyse the performance outcomes of spin bowlers by using a motion analysis procedure to measure the linear and angular kinematics of a spinning ball. A three-dimensional (3D) Cortex motion analysis system was used to track three markers strategically placed on the ball spinning in flight. Data were further processed using 3D vector kinematics to calculate the ball's linear speed, spin rate and direction of the angular velocity vector. Thirty-four district-level spin bowlers, including both finger-spinners and wrist-spinners, were recruited to bowl 20 standard deliveries, and 5 deliveries of any variation in their repertoire. The results show that spin bowlers can produce various combinations of spin rate and angular velocity vector orientations to implement substantially different methods of utilising both swerve and turn off the pitch to deceive the batsman. In particular, it was found that wrist-spin bowlers could potentially swerve the ball either towards the left or right of the batsman. In addition, the ball's angular velocity vector can be displayed during the live capture, which is able to demonstrate spin-bowling performance in the laboratory. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to analyse the kinematics and kinetics of the rear leg drive in fast bowling, and then investigate whether any of these variables were associated with ball release speed. Eighteen young fast bowlers (17.2 ± 1.7 years) were recruited from the Cricket New South Wales development squad, and their bowling actions were captured by a Cortex 2.0 motion analysis system (200 Hz). Bivariate Pearson's product-movement correlation coefficients were calculated in SPSS (Version 17.0) to assess the relationships between wrist speed (of the bowling hand) and the kinematics and kinetics variables corresponding with rear leg motion. A number of kinematic variables were correlated with bowling wrist speed, most of them during the delivery stride, including mean thigh extension angular velocity (r = 0.606,p = 0.008), thigh adduction angular velocity at back foot contact (r = 0.515,p = 0.029) and maximum change in knee extension angular velocity (r = 0.559,p = 0.016). This study also showed that rear leg drive was not an actively actuated process. Instead, the hip and knee motions in the flexion–extension and adduction–abduction planes were generally subjected to controlled and negligible torque motion-effects. [ABSTRACT FROM PUBLISHER]

Understanding how import prices adjust to exchange rates helps anticipate inflation effects and monetary policy responses. This article examines exchange rate pass-through to the monthly import price index in South Africa during 1980–2009. Short-horizon pass-through estimates are calculated using both single equation equilibrium correction models and systems (Johansen) models, controlling for both domestic and foreign costs. Average pass-through is incomplete at about 50 per cent within a year and 30 per cent in six months, and in the long-run, from the Johansen analysis including feedback effects, is about 55 per cent. There is evidence of slower pass-through under inflation targeting; pass-through is found to decline with recent exchange rate volatility and there is evidence for asymmetry, with greater pass-through occurring for small appreciations. [ABSTRACT FROM PUBLISHER]

Heme is vital to our aerobic universe. Heme cellular content is finely tuned through an exquisite control of synthesis and degradation. Heme deficiency is deleterious to cells, whereas excess heme is toxic. Most of the cellular heme serves as the prosthetic moiety of functionally diverse hemoproteins, including cytochromes P450 (P450s). In the liver, P450s are its major consumers, with >50% of hepatic heme committed to their synthesis. Prosthetic heme is the sine qua non of P450 catalytic biotransformation of both endo- and xenobiotics. This well-recognized functional role notwithstanding, heme also regulates P450 protein synthesis, assembly, repair, and disposal. These less well-appreciated aspects are reviewed herein. [ABSTRACT FROM AUTHOR]

The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance. [ABSTRACT FROM AUTHOR]

In 2008, Jerome Joy initiated the 'Networked Music & SoundArt Timeline' (NMSAT)—a monitor on the history of networked music and sound. The Timeline is maintained by the NMSAT Development Committee, consisting primarily of researchers and artists from partner institutions. The team is complemented by a pool of authors and editors contributing to Locus Sonus's projects (such as, for instance, members of WLP - World Listening Project) and individuals who are part of other collaborative projects. The Committee has two major objectives: to amend and expand the existing database comprised currently of more than 2,000 entries and approximately 550 reference articles (NMSAT v.1.090319, March 2009); and to support the online technical and editorial development of the project. This article describes the current state of the timeline and the way in which it has been structured, as well as its evolution towards an open resource database accessible through a variety of specialized interfaces. NMSAT is part of the Locus Sonus research program and provides an essential historical backbone to practice-based artistic research and the exploration of developing technologies. [ABSTRACT FROM AUTHOR]

Despite the increasing role of foreign direct investment (FDI) in economic development, very limited research has been carried out on the causal links between trade, FDI and economic growth in Asian economies. This study examines empirically the inter-play between exports, imports, FDI and economic growth for nine Asian economies by conducting multivariate causality tests in the vector error correction model (VECM) framework. The results reveal two-way causal connections between trade, inward FDI, inward merger and acquisitions (M&As) and growth for most of the sample economies. There is a unidirectional causal link running from outward M&As to growth and trade. These findings suggest that export expansion, import liberalization, FDI inflows and inward M&As are integral elements of the growth process in Asian economies. [ABSTRACT FROM AUTHOR]

Despite the phenomenal development in stock markets in China, there is little research on the linkage between stock prices and economic growth in Greater China: mainland China, Hong Kong and Taiwan. This article represents a step towards systematically investigating the relationship between stock market performance and economic growth in Greater China by conducting causality tests within the VECM framework. We find one-way causality running from growth to stock prices in the long run and also running from stock prices to economic growth in the short run. These findings suggest that economic fundamentals are the main determinants of movements in stock prices in the long run and stock markets act as a leading economic indictor of future economic growth in Greater China in the short run. [ABSTRACT FROM AUTHOR]

The aims of this study were to describe the current anthropometric profiles of elite Australian female and male cricket fast bowlers and establish a set of reference values useful for future investigations on player selection, talent identification, and training programme development. The participants were 26 female (mean age 22.5 years, s = 4.5; height 1.71 m, s = 0.05; body mass 66.2 kg, s = 7.5) and 26 male (mean age 23.9 years, s = 3.5; height 1.88 m, s = 0.05; body mass 87.9 kg, s = 8.2) fast bowlers. The anthropometric profiles included the measurement of skinfolds, and segment lengths, breadths, and girths. A series of derived variables assessing the distribution of subcutaneous adipose tissue, the bivariate overlap zone, relative body size and proportionality, and somatotype were also calculated. The male bowlers had larger length, breadth, and girth measurements than their female counterparts. There were differences in proportionality between the sexes, with only the male bowlers exhibiting characteristics that could be considered "large" relative to height. The female bowlers had a higher sum of seven skinfolds (P < 0.001), were more endomorphic (F1,50 = 30.18, P < 0.001), and less mesomorphic (F1,50 = 10.85, P < 0.01) than the male bowlers. These reference data should be useful to practitioners and researchers interested in cricket. Further research is needed to clarify why only male fast bowlers had variables that were proportionally large relative to height. [ABSTRACT FROM AUTHOR]

Genetic engineering could result in a dramatic transformation of the forest products industry, increasing corporate economic power and concentrating timber production in those regions most suited to industrial-scale tree plantations. We briefly review arguments in favor of and in opposition to genetic engineering in forestry, and describe the constellation of forces promoting this technology. We then examine possible social consequences with specific reference to the pulp and paper industry in the southeastern United States. This study is exploratory in nature, forecasting possible consequences of a development that has not yet taken place. We suggest that the consequences are potentially far-reaching. [ABSTRACT FROM AUTHOR]

The aims of this study were to determine the influence of an 8-over spell on cricket fast bowling technique and performance (speed and accuracy), and to establish the relationship of selected physical capacities with technique and performance during an 8-over spell. Fourteen first-grade fast bowlers with a mean age of 23 years participated in the study. Physical capacities assessed were abdominal strength, trunk stability, selected girth and skinfold measures. During the delivery stride, bowlers were filmed from an overhead and lateral perspective (50 Hz) to obtain two-dimensional data for transverse plane shoulder alignment and sagittal plane knee joint angle respectively. Ball speed was measured by a radar gun and accuracy by the impact point of each delivery on a zoned scoring target at the batter's stumps. Shoulder counter-rotation did not change significantly between overs 2 and 8 for all bowlers, but was significantly related to a more front-on shoulder orientation at back foot impact. When the front-on fast bowlers (n = 5) were isolated for analysis, shoulder counter-rotation increased significantly between overs 2 and 8. Ball speed remained constant while accuracy showed some non-significant variation during the spell. Shoulder counter-rotation was significantly related to accuracy scores during the second half of the 8-over spell. Chest girth and composition and body composition were significantly related to ball release speed at various times during the spell. [ABSTRACT FROM AUTHOR]

An abstract of the article "The effect of jazz shoe design on impact attenuation" by Alycia Fong Yan, Richard Smith, Claire Hiller and Peter Sinclair is presented.