297 research outputs found
Exploring mini rugby union coaches’ perceptions of competitive activities
The purpose of this study was to explore volunteer rugby
union coaches’ perceptions of organised competitive
participation during childhood. Participants were 202 under-9
(U9) mini rugby union coaches who had coached during
the 2010/11 season. Coaches completed an Internet-based
survey, and cluster analysis was used to identify different
groups based on attitudes towards the Rugby Football
Union’s current rules and proposed changes to these rules.
Three distinct groups were identified based on whether they
wanted to maintain the status quo (Traditionalists); maintain
some elements of structure (Moderates); or have a much
less structured introduction to rugby (Radicals). In total, over
three quarters of coaches favoured structured elements
(early specialisation), while less than a quarter favoured a less
structured game (late specialisation). Only the Radical’s views
matched those espoused by elite coaches and U9 players
themselves, raising several issues regarding coach education
for player development during childhood. In the short term
there are the difficulties of aligning disparate views of U9
player development via coaching for and during competitive
games. This is further complicated by the challenges of
enhancing the skills of thousands of volunteer coaches with
limited experience, knowledge and expertise in coaching
during childhood
Playing by the rules: A developmentally appropriate introduction to rugby union
The current study examined the effect of rules changes on game behaviours and opinions of under-nine rugby union players. Eighty-nine games were filmed in five counties in England; two governed by the then current rules and three governed by new pilot rules. The pilot rules were designed to create a less structured game; reducing numbers on the pitch and limiting set pieces and specialised skills. Games played under the pilot rules had 25% more ball-in-play time; 55% more runs with the ball; more than twice as many successful passes; and nearly twice as many tries scored (ps<.001). 272 players participated in a survey. Irrespective of the rules, players identified that passing, running and tackling were key activities, while having fun and playing with friends were their main reasons for playing rugby. The results suggest that the pilot rules create a competitive game that closely matches child-led informal activities.This research was funded by a CASE studentship from the ESRC’s Capacity Building Cluster in Sport, Leisure and Tourism, based at the University of Exeter (RES-187-24-0002), in partnership with the Rugby Football Union. The authors would like to thank all the clubs and players who took part in this research and to Gary Townsend (RFU) for facilitating the process. We would also like to thank Kris James for his assistance in performance analysis of matches
A Comparison of Intermittent and Continuous Exercise Bouts at Different Intensities on Appetite and Postprandial Metabolic Responses in Healthy Men
Exercise intensity affects many potential postprandial responses, but there is limited information on the influence of exercise modality. Therefore, the aim of this study was to investigate if the nature of exercise at two different intensities would affect gastric emptying rate (GER), appetite and metabolic responses following ingestion of a semi-solid meal. Twelve healthy men completed, in a random order, four 60-min cycles at 60% VO2peak (MOD), 40% VO2peak (LOW) and in a continuous (CON) or intermittent (INT) manner. INT consisted of 20 × 1-min exercise bouts with 2-min rest breaks. INT and CON were matched for total work output at each intensity. GER of the post-exercise meal was measured for 2 h using the 13C-breath method. Blood glucose, substrate utilisation and appetite ratings were measured at regular intervals throughout all trials and 24-h energy intake (EI) post-trials was assessed. GER-Delta over Baseline (DOB) was lower (p 0.05). 24-h post-trial EI was similar between LOW-CON vs. LOW-INT (p > 0.05), although MOD-INT vs. MOD-CON 3500 ± 1419 vs. 2556 ± 989 kCal: p < 0.001 was elevated. In summary, MOD-INT exercise delays GER without stimulating perceived appetite in the 2 h period after meal ingestion, although EI was greater in the 24-h post-trial
Real-Reward Testing for Probabilistic Processes (Extended Abstract)
We introduce a notion of real-valued reward testing for probabilistic
processes by extending the traditional nonnegative-reward testing with negative
rewards. In this richer testing framework, the may and must preorders turn out
to be inverses. We show that for convergent processes with finitely many states
and transitions, but not in the presence of divergence, the real-reward
must-testing preorder coincides with the nonnegative-reward must-testing
preorder. To prove this coincidence we characterise the usual resolution-based
testing in terms of the weak transitions of processes, without having to
involve policies, adversaries, schedulers, resolutions, or similar structures
that are external to the process under investigation. This requires
establishing the continuity of our function for calculating testing outcomes.Comment: In Proceedings QAPL 2011, arXiv:1107.074
In vivo interaction between CDKA and eIF4A: a possible mechanism linking translation and cell proliferation
AbstractIn a proteomics-based screen for proteins interacting with cyclin-dependent protein kinase (CDK), we have identified a novel CDK complex containing the eukaryotic translation initiation factor, eIF4A. Reciprocal immunoprecipitations using antibodies against eIF4A indicate that the interaction is specific. The CDKA–eIF4A complex is abundant in actively proliferating and growing cells but is absent from cells that have ceased dividing. The CDKA–eIF4A complex contains kinase activity that is sensitive to the CDK-specific inhibitor roscovitine. This interaction points to a possible molecular mechanism linking cell proliferation with translational control
Two-Player Reachability-Price Games on Single-Clock Timed Automata
We study two player reachability-price games on single-clock timed automata.
The problem is as follows: given a state of the automaton, determine whether
the first player can guarantee reaching one of the designated goal locations.
If a goal location can be reached then we also want to compute the optimum
price of doing so. Our contribution is twofold. First, we develop a theory of
cost functions, which provide a comprehensive methodology for the analysis of
this problem. This theory allows us to establish our second contribution, an
EXPTIME algorithm for computing the optimum reachability price, which improves
the existing 3EXPTIME upper bound.Comment: In Proceedings QAPL 2011, arXiv:1107.074
Surgical management of mediastinal liposarcoma extending from hypopharynx to carina: Case report
We describe the complete resection of a giant, well-differentiated mediastinal liposarcoma extending retropharynx to envelop the aortic arch, trachea and esophagus following preoperative radiotherapy
A Study of the Abrasion of Squeegees Used in Screen Printing and Its Effect on Performance with Application in Printed Electronics
This article presents a novel method for accelerated wear of squeegees used in screen printing and describes the development of mechanical tests which allow more in-depth measurement of squeegee properties. In this study, squeegees were abraded on the screen press so that they could be used for subsequent print tests to evaluate the effect of wear on the printed product. Squeegee wear was found to vary between different squeegee types and caused increases in ink transfer and wider printed features. In production this will lead to greater ink consumption, cost per unit and a likelihood of product failure. This also has consequences for the production of functional layers, etc., used in the construction of printed electronics. While more wear generally gave greater increases in ink deposition, the effect of wear differed, depending on the squeegee. There was a correlation between the angle of the squeegee wear and ink film thickness from a worn squeegee. An ability to resist flexing gave a high wear angle and presented a sharper edge at the squeegee/screen interface thus mitigating the effect of wear. There was also a good correlation between resistance to flexing and ink film thickness for unworn squeegees, which was more effective than a comparison based on Shore A hardness. Squeegee indentation at different force levels gave more information than a standard Shore A hardness test and the apparatus used was able to reliably measure reductions in surface hardness due to solvent absorption. Increases in ink deposition gave lower resistance in printed silver lines; however, the correlation between the amount of ink deposited and the resistance, remained the same for all levels of wear, suggesting that the wear regime designed for this study did not induce detrimental print defects such as line breakages
Performance Evaluation of Components Using a Granularity-based Interface Between Real-Time Calculus and Timed Automata
To analyze complex and heterogeneous real-time embedded systems, recent works
have proposed interface techniques between real-time calculus (RTC) and timed
automata (TA), in order to take advantage of the strengths of each technique
for analyzing various components. But the time to analyze a state-based
component modeled by TA may be prohibitively high, due to the state space
explosion problem. In this paper, we propose a framework of granularity-based
interfacing to speed up the analysis of a TA modeled component. First, we
abstract fine models to work with event streams at coarse granularity. We
perform analysis of the component at multiple coarse granularities and then
based on RTC theory, we derive lower and upper bounds on arrival patterns of
the fine output streams using the causality closure algorithm. Our framework
can help to achieve tradeoffs between precision and analysis time.Comment: QAPL 201
A Stochastic Broadcast Pi-Calculus
In this paper we propose a stochastic broadcast PI-calculus which can be used
to model server-client based systems where synchronization is always governed
by only one participant. Therefore, there is no need to determine the joint
synchronization rates. We also take immediate transitions into account which is
useful to model behaviors with no impact on the temporal properties of a
system. Since immediate transitions may introduce non-determinism, we will show
how these non-determinism can be resolved, and as result a valid CTMC will be
obtained finally. Also some practical examples are given to show the
application of this calculus.Comment: In Proceedings QAPL 2011, arXiv:1107.074
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