ELBOW LOADING DURING THE BACKWARDS HANDSPRING: THE INFLUENCE OF HAND POSITION.

This study aims to investigate the influence of hand position on the musculoskeletal loading at the elbow during the back handspring in female artistic gymnastics. Six national level female gymnasts performed five back handspring trials with “inward”, “parallel” and “outward” hand positions. Synchronised threedimensional kinematic and kinetic data were collected and inverse dynamics analysis performed to calculate elbow joint kinetics. Increased vertical and medio-lateral joint forces and higher medio-lateral moments at the elbow joint during the outward a n d p a r a l l e l hand position may lead to increased injury risk. When using the outward and parallel hand positions, the elbow joint is exposed to increased joint kinetics and biophysical loading that may lead to an increased injury risk when performing the back handspring

INJURY RISK IN TECHNIQUE SELECTION: INFLUENCE OF HAND POSITION IN THE BACK HANDSPRING

This study aims to investigate the influence of hand position on the biomechanical risk factors at the wrist during the back handspring in gymnastics. Three national level female gymnasts performed five back handspring trials with *inwards, "parallels and "outward" hand positions. Synchronised three-dimensional kinematic and kinetic data were collected and inverse dynamics analysis performed to calculate internal wrist joint kinetics. Increased vertical (3.33 +-. 0.82 BW) and medio-lateral (1.74 +- 0.42 BW) force at the wrist joint during the outward hand position may lead to increased injury risk and should be discouraged in practice. However, reduced impact forms at the wrist during the inward hand position may lead to reduced wrist stress, thus lower injury potential during the back handspring

WRIST-ELBOW COORDINATION IN TECHNIQUE SELECTION: INFLUENCE OF HAND POSITION DURING THE BACK HANDSPRING.

This study aims to investigate the influence of hand position on elbow and wrist joint coordination and variability during the back handspring in female gymnastics. Five national level female gymnasts performed five back handspring trials with “inward”, “parallel” and “outward” hand positions. Synchronised three-dimensional kinematic and kinetic data were collected and modified vector coding techniques were used to calculate wrist-elbow coordination. Self-organised coordination patterns were observed for the three hand positions. The “inward” displayed highest coordination variability (24.6o up to 60.5o) with the “parallel” displaying lowest variability (10.8o to 28.3o). Lower variability within the parallel technique may be more suited to gymnastics performance, with the “inward” contributing more towards overuse injury reduction

Iron and silicon isotope behaviour accompanying weathering in Icelandic soils, and the implications for iron export from peatlands

peer reviewe

LIMIT CYCLE DYNAMICS ACROSS ELITE MALE ARTISTIC GYMNASTS

Biological systems described by their attractor dynamics provide a method to understand the fundamental characteristics of skilled movement. Here the limit cycle dynamics of the longswing were investigated across tiers of elite men’s gymnasts. Senior, junior and development elite gymnasts (N=21) performed three trials of eight consecutive longswings on high bar. Limit cycle analysis revealed a more symmetrical angular velocity of the centre of mass about the bar trajectory in phase space, higher recurrence, lower correlation dimension and lower variability for senior gymnasts suggesting a more deterministic, efficient and predictive technique. The addition of non-linear dynamics to traditional biomechanics offers complementary theoretical and coaching knowledge to movement coordination, control and skill

DYNAMICS OF A CYCLIC TASK BEFORE AND AFTER A CHANGE IN TASK CONSTRAINT: HORIZONTAL BAR LONGSWING

Returning to a consistent technique after a change in skill allows gymnasts to improve routine fluidity. This study investigates the limit cycle dynamics of the mass centre (CM) after a variation in task constraint during the horizontal bar longswing (LS). Gymnasts (n=12) from 3 different age categories completed 3 x 8 consecutive LS with LS four and five as accelerated LS. Senior gymnasts presented the most consistent limit cycle trajectory and lowest correlation dimension (CD) post- compared to pre- task constraint. Senior gymnasts displayed significantly lower CD post- constraint compared to both junior (p = .016) and development gymnasts (p\u3c .001). The increased proficiency attributed to senior gymnasts appears to increase the stability features of the LS limit cycle of the CM angular velocity after an imposed task constraint which may indicate readiness to progress to more complex horizontal bar skills

Understanding the direct and indirect mechanisms of xylanase action on starch digestion in broilers

The objective of the current study was to investigate the mechanisms of xylanase action in a maize-soya diet and its effect on starch digestion. A total of 60 broilers were divided into 6 treatment groups; a control group without xylanase, and five other groups supplemented with xylanase (Econase XT 25; 100 g/t) from 1, 2, 3, 4 or 5 weeks before slaughter. At the end of the experiment, digesta was collected from the gizzard, upper and lower small intestine, and both caeca. Digesta pH ranged from pH 2.2-4.4, 5.9-6.6, 6.7-7.8 and 5.7-7.3 in the gizzard, upper small intestine, lower small intestine, and both caeca, respectively, with no effect of xylanase (P > 0.05). Scanning Electron Microscope (SEM) images along with total starch measurements showed the progression of starch digestion through the tract. The SEM did not show any greater disruption to cell wall material with xylanase supplementation. This suggests that xylanase was not working directly on the cell wall and provides evidence for the hypothesis that xylanase works through an indirect mechanism. Peptide YY (PYY) concentration in the blood was higher during the first few weeks of supplementation, with longer periods of supplementation nulling this effect, implying that xylanase may be acting through a prebiotic mechanism. The RT-q PCR results revealed a numerical increase in glucose transporter (GLUT2 and SGLT1) expression at 2 and 3 weeks of xylanase supplementation, respectively, which might suggest a greater absorption capacity of birds. From these results, a potential mechanism of xylanase action in maize-based diets has been proposed

Erratum: Causal Knowledge Promotes Behavioral Self-Regulation: An Example using Climate Change Dynamics (PLoS ONE (2017) 12:9 (E0184480) DOI: 10.1371/Journal.pone.0184480)

In the Task overview: Managing a dynamic human-climate system subsection of the Introduction, there is an error in equation 4. There is a factor of τ that is missing from the denominator of the first term that appears on the right-hand side of the equation. Please view the complete, correct equation here [Formula Presented]

Flexible voices : Identity perception from variable vocal signals

Human voices are extremely variable: The same person can sound very different depending on whether they are speaking, laughing, shouting or whispering. In order to successfully recognise someone from their voice, a listener needs to be able to generalize across these different vocal signals (‘telling people together’). However, in most studies of voice-identity processing to date, the substantial within-person variability has been eliminated through the use of highly controlled stimuli, thus focussing on how we tell people apart. We argue that this obscures our understanding of voice-identity processing by controlling away an essential feature of vocal stimuli that may include diagnostic information. In this paper, we propose that we need to extend the focus of voice-identity research to account for both “telling people together” as well as “telling people apart.” That is, we must account for whether, and to what extent, listeners can overcome within-person variability to obtain a stable percept of person identity from vocal cues. To do this, our theoretical and methodological frameworks need to be adjusted to explicitly include the study of within-person variability

Applying and extending the theory of effective use in a business intelligence context

The benefits that organizations accrue from information systems depend on how effectively the systems are used. Yet despite the importance of knowing what it takes to use information systems effectively, little theory on the topic exists. One recent and largely untested exception is the theory of effective use (TEU). We report on a contextualization, extension, and test of TEU in the business intelligence (BI) context, a context of considerable importance in which researchers have called for such studies. We used a mixed-method, three-phase approach involving instrument development (n = 218), two-wave cross-sectional survey (n = 437), and three sets of follow-up interviews (n = 33). The paper contributes by (1) showing how TEU can be contextualized, operationalized, and extended, (2) demonstrating that many of TEU’s predictions hold in the BI context while also revealing ways to improve the theory, and (3) offering practical insights executives can draw on to improve use of BI in their organizations