The aim of this study was to examine whether perceptual variables can provide informational constraints for the goalkeepers to intercept the ball successfully in 1v1 dyads. Video images of 42 actions (1v1 in direct shots) were selected randomly from different matches and divided into conceded goals (n = 20) and saved actions (n = 22) to investigate interceptive actions of 20 goalkeepers in the English Premier League in season 2013-2014. Time to Contact (TTC) of the closing distance gap between shooter and goalkeeper was obtained by digitising actions in the 18-yard penalty box. Statistical analyses revealed that, in sequences of play resulting in an intercepted shot at goal, goalkeepers closed down outfield players in the X axis, whereas when a goal was conceded, there was a significantly delayed movement by goalkeepers toward the shooters in this plane. The results of canonical correlations showed that a decreasing distance between a shooter and goalkeeper, and accompanied reduction in relative interpersonal velocity followed a temporal pattern. Findings of this study showed how perception of key informational constraints on dyadic system relations, such as TTC, interpersonal distance and relative velocity, constrain elite goalkeepers' interceptive actions, playing an important role in successful performance.
Haemadipsid leeches are among the most successful terrestrial invertebrates in Bornean rainforests. They are very common ectoparasites of vertebrates, and their abundance has facilitated the conduction of numerous projects in the fields of ecology, zoogeography and taxonomy. We undertook research on two species inhabiting lowland dipterocarp forest, Haemadipsa picta Moore, 1929 and Haemadipsa subagilis (Moore, 1929), in order to address the following questions: (a) is there a difference in leech abundance between trails and off-trails?; (b) is ambush location dependent on specimen size or is species-specific?; (c) is intra- and interspecific competition limited by differences in foraging behaviours or vertical niche partitioning? Our results clearly show that H. picta is more abundant on trails than on off-trails and is vertically dispersed within the understory; the size of a specimen is strongly correlated with plant height. Haemadipsa subagilis was found not to exhibit such patterns. We suggest a possible lowering of interspecific competition between these species as a result of: (i) size-dependent dispersion of H. picta (together with reduction of intraspecific competition); and (ii) habitat specialisation of H. subagilis. Moreover, we provide new observations on their foraging behaviour.
Understanding how species assemble into communities is a key goal in ecology. However, assembly rules are rarely tested experimentally, and their ability to shape real communities is poorly known. We surveyed a diverse community of epiphyte-dwelling ants and found that similar-sized species co-occurred less often than expected. Laboratory experiments demonstrated that invasion was discouraged by the presence of similarly sized resident species. The size difference for which invasion was less likely was the same as that for which wild species exhibited reduced co-occurrence. Finally we explored whether our experimentally derived assembly rules could simulate realistic communities. Communities simulated using size-based species assembly exhibited diversities closer to wild communities than those simulated using size-independent assembly, with results being sensitive to the combination of rules employed. Hence, species segregation in the wild can be driven by competitive species assembly, and this process is sufficient to generate observed species abundance distributions for tropical epiphyte-dwelling ants.
Traditional department-based surgical interest groups in Russian medical schools are useful tools for student-based selection of specialty training. They also form a nucleus for initiating research activities among undergraduate students. In Russia, the Departments of Topographical Anatomy and Operative Surgery play an important role in initiating student-led research and providing learners with advanced, practical surgical skills. In tandem with department-led activities, student surgical interest groups prepare learners through surgical competitions, known as "Surgical Olympiads," which have been conducted in many Russian centers on a regular basis since 1988. Surgical Olympiads stimulate student interest in the development of surgical skills before graduation and encourage students to choose surgery as their postgraduate specialty. Many of the participants in these surgical Olympiads have become highly qualified specialists in general surgery, orthopedic surgery, neurosurgery, urology, gynecology, and emergency medicine. The present article emphasizes the role of student interest groups and surgical Olympiads in clinical anatomical and surgical undergraduate training in Russia.
This study sought to understand the factors associated with street racing among the illegal motorcycle racers in Malaysia or known as the "Mat Rempit".
In primates, living in an anthropogenic environment can significantly improve an individual's fitness, which is likely attributed to access to anthropogenic food resources. However, in non-professionally provisioned groups, few studies have examined whether individual attributes, such as dominance rank and sex, affect primates' ability to access anthropogenic food. Here, we investigated whether rank and sex explain individual differences in the proportion of anthropogenic food consumed by macaques. We observed 319 individuals living in nine urban groups across three macaque species. We used proportion of anthropogenic food in the diet as a proxy of access to those food resources. Males and high-ranking individuals in both sexes had significantly higher proportions of anthropogenic food in their diets than other individuals. We speculate that unequal access to anthropogenic food resources further increases within-group competition, and may limit fitness benefits in an anthropogenic environment to certain individuals.
Sports performance is generally considered to be governed by a range of interacting physiological, biomechanical, and psychological variables, amongst others. Despite sports performance being multi-factorial, however, the majority of performance-oriented sports science research has predominantly been monodisciplinary in nature, presumably due, at least in part, to the lack of a unifying theoretical framework required to integrate the various subdisciplines of sports science. In this target article, I propose a Grand Unified Theory (GUT) of sports performance-and, by elaboration, sports science-based around the constraints framework introduced originally by Newell (1986). A central tenet of this GUT is that, at both the intra- and inter-individual levels of analysis, patterns of coordination and control, which directly determine the performance outcome, emerge from the confluence of interacting organismic, environmental, and task constraints via the formation and self-organisation of coordinative structures. It is suggested that this GUT could be used to: foster interdisciplinary research collaborations; break down the silos that have developed in sports science and restore greater disciplinary balance to the field; promote a more holistic understanding of sports performance across all levels of analysis; increase explanatory power of applied research work; provide stronger rationale for data collection and variable selection; and direct the development of integrated performance monitoring technologies. This GUT could also provide a scientifically rigorous basis for integrating the subdisciplines of sports science in applied sports science support programmes adopted by high-performance agencies and national governing bodies for various individual and team sports.
Cricket has over the years gained much popularity in Asia, thus the number of cricket players has also grown in tandem. However, cricket players are not as fortunate as other athletes as they do not always have a standard cricket infrastructure to practice; therefore, the injury prevalence is expected to be high. Unfortunately, very few studies have been conducted to investigate the nature and pattern of cricket injuries prevalent to cricketers in this region. Therefore, a prospective cohort injury surveillance study was conducted during the Asian Cricket Council (ACC) Under-19 Elite Cup held in June 2013 in order to gather more data on the type of injuries sustained by cricket players. Overall, 31 injuries occurred to 28 players throughout the tournament, of which 7 injuries happened during practice sessions. The overall injury incidence rate (IIR) was 292.0 per 10,000 player hours (95% CI 176.9-407.1) and 10.4 per 10,000 balls faced and 2.6 per 1000 overs bowled delivered during batting and bowling, respectively. Injuries to the lower limb (IIR: 146; 95% CI 1.8-98.2) were the most frequent, followed by injuries to the upper limb (97.3;95% CI 30.2-164.5) and to the trunk and back (IIR: 36.5;95% CI 0.0-77.7). Sprain/strains (IIR 109.5;95% CI 38.4-180.7) to muscle/tendon and joint/ligament were the most commonly reported nature of injury. This is the first study investigating injury incidence among the players of the ACC. It provides an overview of injuries sustained by elite players' under-19 years of age from 10 Asian countries. The overall IIR is similar to earlier studies conducted in well-established cricket playing nations.
Budding and relocation of nests are important characteristics of the Pharaoh ant, Monomorium pharaonis (L.), an important pest of artificial structures. Pharaoh ant colony movements induced by several types of disturbances were evaluated in the laboratory. The percentages of workers and brood in the source and new nest sites were determined at Days 0, 1, 3, and 5 following physical disturbance (temporal removal of nestmates), chemical disturbance (application of pyrethroid insecticide), invasion by heterospecific ants, food depletion, and moisture depletion in the laboratory. All disturbances were performed in the source nest, which was connected to an empty new nest site. Almost all workers moved and carried the entire brood to the new nest site when subjected to physical disturbance, chemical disturbance, and ant invasion on Day 1, whereas only <5% of workers were present in the new nest site in the undisturbed control. After these disturbances, the brood was never relocated back to the original nest site in this 5-d study. When subjected to food depletion, ∼60% of the brood were found in the new nest site and ∼40% of the brood remained in the original nest on Day 5, resulting in a polydomous population. In contrast, moisture depletion did not show any significant effect on colony movement. These results provide useful information about the causes of Pharaoh ant colony budding and guidance about how to develop effective control and prevention strategies.
We conducted the world's first experiments under semi-field conditions (ACL-2 field house) to assess the mating competitiveness of genetically sterile RIDL male mosquitoes (513A strain). The field house is a state-of-the-art, fully-contained trial facility, simulating the living space for a household of 2-4 people in Peninsular Malaysia. Ten genetically sterile RIDL male A. aegypti mosquitoes competed with ten wild type males inside this field house to mate with ten wild type females. Hatched larvae from mated females were screened under a fluorescent microscope for genetic markers to determine if they were fathered by RIDL male or wild type male, and all results were cross-checked by PCR. Two such experiments were conducted, each repeated sufficient number of times. All strains were on a Malaysian lab strain background for the first experiment, while the RIDL males alone were on a recently-colonised Mexican strain background for the second experiment. A total of 52 % of the matings were with RIDL males in the first experiment, while 45 % of the matings were with RIDL (Mexican) males in the second experiment. Statistically, this is not significantly different from 50 % of the matings expected to take place with RIDL males if the latter were as competitive as that of the wild type males. This shows that A. aegypti RIDL-513A has excellent mating competitiveness under semi-field conditions, verifying earlier trends obtained in small lab cages. We also observed high mating compatibility between recently-colonised Mexican RIDL males and lab-reared Malaysian wild type females.
Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.
Practice plays an important role in skill acquisition, although not all practice is of equal quality. We examined the types of team practice activities in four groups of youth cricket players. The groups were recreational- and elite-children (9 to 12 years of age) and recreational- and elite-adolescent players (13 to 17 years of age). Time motion analysis recorded the duration in two types of practice activities, namely, Training Form and Playing Form. Training Form is mainly drill-type activities, whereas Playing Form is mainly games-based activities. Training Form activity is thought to contain fewer opportunities to develop the perceptual, cognitive and motor skills required for successful performance in competition when compared to Playing Form. Session duration was a mean value of 95, s = 29 min. All players combined spent 69% of session time in Training Form activity and 19% in Playing Form, with the remaining percentage of time spent in transition between activities. Recreational-children spent around half of their time in Playing Form activity, whereas both elite and adolescent groups spent little or no time in this activity. Findings from this research highlight a gap between research and practice that may not be optimal for skill acquisition.
Psychological differences between women and men, far from being invariant as a biological explanation would suggest, fluctuate in magnitude across cultures. Moreover, contrary to the implications of some theoretical perspectives, gender differences in personality, values, and emotions are not smaller, but larger, in American and European cultures, in which greater progress has been made toward gender equality. This research on gender differences in self-construals involving 950 participants from 5 nations/cultures (France, Belgium, the Netherlands, the United States, and Malaysia) illustrates how variations in social comparison processes across cultures can explain why gender differences are stronger in Western cultures. Gender differences in the self are a product of self-stereotyping, which occurs when between-gender social comparisons are made. These social comparisons are more likely, and exert a greater impact, in Western nations. Both correlational and experimental evidence supports this explanation.