199 research outputs found
Impact of established clubs on probability of survival in top leagues
Football leagues across the world apply the European promotion-relegation model, where the best teams in the highest-ranking minor league are promoted to the major league from which the worst teams are relegated to the former. This paper proposes a simple statistical model that calculates the probability of non-established clubs avoiding relegation, by assuming the existence of a cohort of established clubs, which rarely if ever are relegated. It uses three data items (i.e. total number of clubs, number of established clubs and number of clubs relegated). It is the number of established clubs which is critical, rather than which clubs should be so categorised. For illustrative purposes the model was applied to the English Football Premier League (EFPL) for its first twenty-one seasons. It was found that the means of the model and the observed distributions for the key EFPL cohorts of seven and eleven established clubs were not significantly different statistically, suggesting that the model reasonably reflects the observed distribution for each size of established group. Also, the probability of a (non-established) club surviving eight seasons, assuming no established clubs, was 600% greater than if there were a cohort of eleven established EFPL clubs. This demonstrates that the projected probability of survival will be greatly overestimated unless a cohort of established clubs is assumed. Any football club in such a major league, particularly one that is newly promoted, can use this statistical model to calculate the probability of avoiding relegation and thereby generate a more sensitive assessment of risk
The Use of Patterns to Disguise Environmental Cues During an Anticipatory Judgment Task
A number of novel manipulations to the design of playing uniforms were used to try to disguise the actions of penalty takers in soccer. Skilled and less-skilled soccer goalkeepers were required to anticipate penalty kick outcome while their opponent wore one of three different uniform designs that were intended to disguise the availability of potentially key information from the hip region. Variations of shapes/patterns were designed to conceal the actual alignment of the hips. Three occlusion points were used in the test film: -160 ms, -80 ms before, and at foot-ball contact. Skilled individuals reported higher accuracy scores than their less-skilled counterparts (p .05); however, the skilled group decreased their accuracy on the experimental conditions compared with the control (p < .05). Findings highlight the potential benefits of designing playing uniforms that facilitate disguise in sport
The malaria parasite cyclic GMP-dependent protein kinase plays a central role in blood-stage schizogony
A role for the Plasmodium falciparum cyclic GMP (cGMP)-dependent protein kinase (PfPKG) in gametogenesis in the malaria parasite was elucidated previously. In the present study we examined the role of PfPKG in the asexual blood-stage of the parasite life cycle, the stage that causes malaria pathology. A specific PKG inhibitor (compound 1, a trisubstituted pyrrole) prevented the progression of P. falciparum schizonts through to ring stages in erythrocyte invasion assays. Addition of compound 1 to ring-stage parasites allowed normal development up to 30 h postinvasion, and segmented schizonts were able to form. However, synchronized schizonts treated with compound 1 for ≥6 h became large and dysmorphic and were unable to rupture or liberate merozoites. To conclusively demonstrate that the effect of compound 1 on schizogony was due to its selective action on PfPKG, we utilized genetically manipulated P. falciparum parasites expressing a compound 1-insensitive PfPKG. The mutant parasites were able to complete schizogony in the presence of compound 1 but not in the presence of the broad-spectrum protein kinase inhibitor staurosporine. This shows that PfPKG is the primary target of compound 1 during schizogony and provides direct evidence of a role for PfPKG in this process. Discovery of essential roles for the P. falciparum PKG in both asexual and sexual development demonstrates that cGMP signaling is a key regulator of both of these crucial life cycle phases and defines this molecule as an exciting potential drug target for both therapeutic and transmission blocking action against malaria
Improved synchronous production of Plasmodium falciparum gametocytes in vitro.
The sexual stages of the Plasmodium falciparum life cycle are attractive targets for vaccines and transmission blocking drugs. Difficulties in culturing and obtaining large amounts of sexual stage P. falciparum parasites, particularly early stages, have often limited research progress in this area. We present a new protocol which simplifies the process of stimulating gametocytogenesis leading to improved synchronous gametocyte production. This new method can be adapted to enrich for early stage gametocytes (I and II) with a higher degree of purity than has previously been achieved, using MACS magnetic affinity columns. The protocol described lends itself to large scale culturing and harvesting of synchronous parasites suitable for biochemical assays, northern blots, flow cytometry, microarrays and proteomic analysis
Evaluating the effectiveness of styles of play in elite soccer
The aim of this study was to evaluate the effectiveness of styles of play in soccer and the influence of contextual variables (i.e. match status, venue and quality of opposition). Team possessions (n = 68,766) from the 380 matches of the 2015–2016 English Premier League season were collected for this study. The Possession Effectiveness Index, based on Expected Goals and Ball Movement Points metrics, was used to measure the effectiveness of team possessions. Linear mixed models were applied to analyse the influence of contextual variables on the effectiveness score for each style. Results showed that the effectiveness of Direct Play, Counterattack, Maintenance and Crossing significantly increased when teams were winning by two or more goals. Counterattack increased its effectiveness when teams were winning by one goal and reduced its effectiveness when losing by one goal. The effectiveness of Direct Play increased when losing by two goals or more. Playing away negatively affected the effectiveness of Direct Play, Maintenance and High Pressure. In addition, playing against a stronger opposition reduced the effectiveness of all styles of play. The results suggest that the effectiveness of styles of play changes under specific circumstances and that not all contextual variables affect them in the same way
Anthropometric and Performance Characteristics of Elite Hurling Players
The purpose of the present study was to examine variations in the anthropometric and performance characteristics of elite hurling players in relation to playing position. Forty-one male, elite intercounty hurlers (25 ± 4 years), 4 goalkeepers, 8 full-backs, 8 halfback, 6 midfielders, 8 half-forwards and 7 full-forwards underwent measurements of standard anthropometric (stature, body mass, sum of five skinfolds and adipose tissue percentage estimates (%AT)) and performance characteristics (counter-movement jump (CMJ), CMJ peak power, CMJ relative peak power, 5-, 10-, 20-m sprint times and estimated V•O2max) during the later stages of the competitive season. A clear hierarchical anthropometric profile is evident with goalkeepers being the taller (184.3 ± 3.7 m), possessing the highest body mass (88.7 ± 5.7 kg) and adiposity (13.2 ± 3.1 %AT) than their outfield colleagues. Half-backs (47.4 ± 2.4 cm) and half-forwards (50.7 ± 5.9 cm) produced the highest CMJ scores; a similar profile was evident for sprint times. Midfielders (60.1 ± 1.4 mL.kg-1.min-1) exhibited a significantly (p<0.05) greater maximal oxygen uptake than all other playing positions. Differences in the anthropometric and performance characteristics of other playing positions whilst evident were non-significant. This study provides novel data, as it is the first report to present normative anthropometric and performance data for elite hurling players which to date has not been present in the literature. The enhanced maximal oxygen uptake in midfield players is likely due to different performance, technical and tactical demands associated with this position
The Work-Rate of Elite Hurling Match-Play
This study describes the global work-rate of elite hurling match-play and the influence which positional difference has on workrate is considered. The movement of ninety-four players was recorded using global positioning system, sampling at 4 Hz in a total of 12 games. Data were classified according to the positional line on the field and period of the match. The total and high-speed distance of match-play was 7,617 6 1,219 m (95% confidence interval [CI], 7,367–7,866) and 1,134 6 358 m (95% CI, 1,060–1,206), respectively. The maximum speed attained was 29.8 6 2.3 km.h-1 with a mean speed of 6.1 6 1 kmh 21. The second {271 6 107 m (p = 0.001; effect size [ES] = 0.25)}, third (278 6 118 m [p = 0.001; ES = 0.21]), and fourth quarter (255 6 108 m [p = 0.001; ES = 0.31]) high-speed running distance differed significantly from that of the first quarter (330 6 120 m). There was a significant difference in total (p = 0.001; ES = 0.01–0.85), high-speed running (p = 0.001; ES = 0.21–0.76), and sprint (p = 0.013; ES = 0.01–0.39) distance across the positions, with midfielders undertaking the highest volume of work, followed by the half-forward and half-back lines and finally the full-forward and full-back lines. A decrease in high-speed running distance seems to occur through out the game and in particular at the latter stages of each half. Distinct positional work profiles are evident. The present finding provide a context on which training which replicates the work-rate of match-play may be formulated, thus helping to improve the physical preparation of elite players
Contextual information influences diagnosis accuracy and decision making in simulated emergency medicine emergencies
Background: It is well documented that adaptations in cognitive processes with increasing skill levels support decision making in multiple domains. We examined skill-based differences in cognitive processes in emergency medicine physicians, and whether performance was significantly influenced by the removal of contextual information related to a patient's medical history. Method: Skilled (n=9) and less skilled (n=9) emergency medicine physicians responded to high-fidelity simulated scenarios under high- and low-context information conditions. Results: Skilled physicians demonstrated higher diagnostic accuracy irrespective of condition, and were less affected by the removal of context-specific information compared with less skilled physicians. The skilled physicians generated more options, and selected better quality options during diagnostic reasoning compared with less skilled counterparts. These cognitive processes were active irrespective of the level of context-specific information presented, although high-context information enhanced understanding of the patients' symptoms resulting in higher diagnostic accuracy. Conclusions: Our findings have implications for scenario design and the manipulation of contextual information during simulation training
A Scoping Review of the Potential Sociological Predictors of Talent in Junior-elite Football: 2000-2016
The purpose of this scoping review was to examine the potential 27 sociological predictors for identifying talent in junior-elite football. Four 28 academic databases were searched using a systematic search strategy and 29 nine eligibility criteria were applied to ensure only relevant studies were 30 included in the review. A total of 1,107 potential studies were returned for 31 the review, however 1,083 did not meet the eligibility criteria and a further 32 12 articles were excluded after further screening. Two follow up searches 33 yielded one additional article for inclusion. In total, 13 articles were 34 included in the final scoping review. These studies aligned to four 35 potential sociological predictors of talent in football: 1) hours in practice; 36 2) coach-child interaction; 3) parental support; and 4) education. Each 37 potential predictor is examined in detail with key findings summarised 38 before impact for practice and future research direction is proposed
The malaria parasite cyclic GMP-dependent protein kinase plays a central role in blood-stage schizogony.
A role for the Plasmodium falciparum cyclic GMP (cGMP)-dependent protein kinase (PfPKG) in gametogenesis in the malaria parasite was elucidated previously. In the present study we examined the role of PfPKG in the asexual blood-stage of the parasite life cycle, the stage that causes malaria pathology. A specific PKG inhibitor (compound 1, a trisubstituted pyrrole) prevented the progression of P. falciparum schizonts through to ring stages in erythrocyte invasion assays. Addition of compound 1 to ring-stage parasites allowed normal development up to 30 h postinvasion, and segmented schizonts were able to form. However, synchronized schizonts treated with compound 1 for > or =6 h became large and dysmorphic and were unable to rupture or liberate merozoites. To conclusively demonstrate that the effect of compound 1 on schizogony was due to its selective action on PfPKG, we utilized genetically manipulated P. falciparum parasites expressing a compound 1-insensitive PfPKG. The mutant parasites were able to complete schizogony in the presence of compound 1 but not in the presence of the broad-spectrum protein kinase inhibitor staurosporine. This shows that PfPKG is the primary target of compound 1 during schizogony and provides direct evidence of a role for PfPKG in this process. Discovery of essential roles for the P. falciparum PKG in both asexual and sexual development demonstrates that cGMP signaling is a key regulator of both of these crucial life cycle phases and defines this molecule as an exciting potential drug target for both therapeutic and transmission blocking action against malaria
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