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Sample records for online poker players

  1. Psychopathology of Online Poker Players: Review of Literature

    PubMed Central

    Moreau, Axelle; Chabrol, Henri; Chauchard, Emeline

    2016-01-01

    Background and aims Online Texas Hold’em poker has become a spectacular form of entertainment in our society, and the number of people who use this form of gambling is increasing. It seems that online poker activity challenges existing theoretical concepts about problem gambling behaviors. The purpose of this literature review is to provide a current overview about the population of online poker players. Methods To be selected, articles had to focus on psychopathology in a sample of online poker players, be written in English or French, and be published before November 2015. A total of 17 relevant studies were identified. Results In this population, the proportion of problematic gamblers was higher than in other forms of gambling. Several factors predicting excessive gambling were identified such as stress, internal attribution, dissociation, boredom, negative emotions, irrational beliefs, anxiety, and impulsivity. The population of online poker players is largely heterogeneous, with experimental players forming a specific group. Finally, the validity of the tools used to measure excessive or problematic gambling and irrational beliefs are not suitable for assessing online poker activity. Discussion and conclusions Future studies need to confirm previous findings in the literature of online poker games. Given that skills are important in poker playing, skill development in the frames of excessive use of online poker should be explored more in depth, particularly regarding poker experience and loss chasing. Future research should focus on skills, self-regulation, and psychopathology of online poker players. PMID:27348559

  2. Psychopathology of Online Poker Players: Review of Literature.

    PubMed

    Moreau, Axelle; Chabrol, Henri; Chauchard, Emeline

    2016-06-01

    Background and aims Online Texas Hold'em poker has become a spectacular form of entertainment in our society, and the number of people who use this form of gambling is increasing. It seems that online poker activity challenges existing theoretical concepts about problem gambling behaviors. The purpose of this literature review is to provide a current overview about the population of online poker players. Methods To be selected, articles had to focus on psychopathology in a sample of online poker players, be written in English or French, and be published before November 2015. A total of 17 relevant studies were identified. Results In this population, the proportion of problematic gamblers was higher than in other forms of gambling. Several factors predicting excessive gambling were identified such as stress, internal attribution, dissociation, boredom, negative emotions, irrational beliefs, anxiety, and impulsivity. The population of online poker players is largely heterogeneous, with experimental players forming a specific group. Finally, the validity of the tools used to measure excessive or problematic gambling and irrational beliefs are not suitable for assessing online poker activity. Discussion and conclusions Future studies need to confirm previous findings in the literature of online poker games. Given that skills are important in poker playing, skill development in the frames of excessive use of online poker should be explored more in depth, particularly regarding poker experience and loss chasing. Future research should focus on skills, self-regulation, and psychopathology of online poker players.

  3. Profiling Online Poker Players: Are Executive Functions Correlated with Poker Ability and Problem Gambling?

    PubMed

    Schiavella, Mauro; Pelagatti, Matteo; Westin, Jerker; Lepore, Gabriele; Cherubini, Paolo

    2018-01-12

    Poker playing and responsible gambling both entail the use of the executive functions (EF), which are higher-level cognitive abilities. This study investigated if online poker players of different ability showed different performances in their EF and if so, which functions were the most discriminating for their playing ability. Furthermore, it assessed if the EF performance was correlated to the quality of gambling, according to self-reported questionnaires (PGSI, SOGS, GRCS). Three poker experts evaluated anonymized poker hand history files and, then, a trained professional administered an extensive neuropsychological test battery. Data analysis determined which variables of the tests correlated with poker ability and gambling quality scores. The highest correlations between EF test results and poker ability and between EF test results and gambling quality assessment showed that mostly different clusters of executive functions characterize the profile of the strong(er) poker player and those ones of the problem gamblers (PGSI and SOGS) and the one of the cognitions related to gambling (GRCS). Taking into consideration only the variables overlapping between PGSI and SOGS, we found some key predictive factors for a more risky and harmful online poker playing: a lower performance in the emotional intelligence competences (Emotional Quotient inventory Short) and, in particular, those grouped in the Intrapersonal scale (emotional self-awareness, assertiveness, self-regard, independence and self-actualization).

  4. Anxiety, Depression and Emotion Regulation Among Regular Online Poker Players.

    PubMed

    Barrault, Servane; Bonnaire, Céline; Herrmann, Florian

    2017-12-01

    Poker is a type of gambling that has specific features, including the need to regulate one's emotion to be successful. The aim of the present study is to assess emotion regulation, anxiety and depression in a sample of regular poker players, and to compare the results of problem and non-problem gamblers. 416 regular online poker players completed online questionnaires including sociodemographic data, measures of problem gambling (CPGI), anxiety and depression (HAD scale), and emotion regulation (ERQ). The CPGI was used to divide participants into four groups according to the intensity of their gambling practice (non-problem, low risk, moderate risk and problem gamblers). Anxiety and depression were significantly higher among severe-problem gamblers than among the other groups. Both significantly predicted problem gambling. On the other hand, there was no difference between groups in emotion regulation (cognitive reappraisal and expressive suppression), which was linked neither to problem gambling nor to anxiety and depression (except for cognitive reappraisal, which was significantly correlated to anxiety). Our results underline the links between anxiety, depression and problem gambling among poker players. If emotion regulation is involved in problem gambling among poker players, as strongly suggested by data from the literature, the emotion regulation strategies we assessed (cognitive reappraisal and expressive suppression) may not be those involved. Further studies are thus needed to investigate the involvement of other emotion regulation strategies.

  5. Cognitive distortions, anxiety, and depression among regular and pathological gambling online poker players.

    PubMed

    Barrault, Servane; Varescon, Isabelle

    2013-03-01

    The aims were to assess cognitive distortions and psychological distress (anxiety and depression) among online poker players of different levels of gambling intensity (non-pathological gamblers [NPG], problem gamblers [PbG], and pathological gamblers [PG]), and to examine the relationship between these variables and gambling pathology. Overall, 245 regular online poker players recruited on an Internet forum completed online self-report scales assessing pathological gambling (South Oaks Gambling Screen [SOGS]), psychological distress (Hospital Anxiety and Depression Scale [HADS]) and cognitive distortions (Gambling-Related Cognition Scale). Based on their SOGS scores, poker players were ranked into three groups: NPG (n=146), PbG (n=55), and PG (n=44). All poker players appeared to be more anxious than depressive. PG exhibited higher levels of depression and anxiety than did PbG and NPG. Cognitive distortions also significantly discriminated PG from PbG and NPG. A regression model showed that the perceived inability to stop gambling, the illusion of control, depression (HADS D), and anxiety were good predictors for pathological gambling among poker players. Our results suggest that cognitive distortions play an important role in the development and maintenance of gambling pathology. This study also underlines the role of anxiety and depression in pathological gambling among poker players. It seems relevant to take these elements into account in the research, prevention, and treatment of pathological gambling poker players.

  6. What Differentiates Professional Poker Players from Recreational Poker Players? A Qualitative Interview Study

    ERIC Educational Resources Information Center

    McCormack, Abby; Griffiths, Mark D.

    2012-01-01

    The popularity of poker (and in particular online poker) has increasingly grown worldwide in recent years. This increase in the popularity of poker has led to the increased incidence of the "professional poker player". However, very little empirical research has been carried out into this relatively new group of gamblers. The aim was to determine…

  7. Factor Structure of the Internet Addiction Test in Online Gamers and Poker Players.

    PubMed

    Khazaal, Yasser; Achab, Sophia; Billieux, Joel; Thorens, Gabriel; Zullino, Daniele; Dufour, Magali; Rothen, Stéphane

    2015-01-01

    The Internet Addiction Test (IAT) is the most widely used questionnaire to screen for problematic Internet use. Nevertheless, its factorial structure is still debated, which complicates comparisons among existing studies. Most previous studies were performed with students or community samples despite the probability of there being more problematic Internet use among users of specific applications, such as online gaming or gambling. To assess the factorial structure of a modified version of the IAT that addresses specific applications, such as video games and online poker. Two adult samples-one sample of Internet gamers (n=920) and one sample of online poker players (n=214)-were recruited and completed an online version of the modified IAT. Both samples were split into two subsamples. Two principal component analyses (PCAs) followed by two confirmatory factor analyses (CFAs) were run separately. The results of principal component analysis indicated that a one-factor model fit the data well across both samples. In consideration of the weakness of some IAT items, a 17-item modified version of the IAT was proposed. This study assessed, for the first time, the factorial structure of a modified version of an Internet-administered IAT on a sample of Internet gamers and a sample of online poker players. The scale seems appropriate for the assessment of such online behaviors. Further studies on the modified 17-item IAT version are needed.

  8. Factor Structure of the Internet Addiction Test in Online Gamers and Poker Players

    PubMed Central

    Achab, Sophia; Billieux, Joel; Thorens, Gabriel; Zullino, Daniele; Dufour, Magali; Rothen, Stéphane

    2015-01-01

    Background The Internet Addiction Test (IAT) is the most widely used questionnaire to screen for problematic Internet use. Nevertheless, its factorial structure is still debated, which complicates comparisons among existing studies. Most previous studies were performed with students or community samples despite the probability of there being more problematic Internet use among users of specific applications, such as online gaming or gambling. Objective To assess the factorial structure of a modified version of the IAT that addresses specific applications, such as video games and online poker. Methods Two adult samples—one sample of Internet gamers (n=920) and one sample of online poker players (n=214)—were recruited and completed an online version of the modified IAT. Both samples were split into two subsamples. Two principal component analyses (PCAs) followed by two confirmatory factor analyses (CFAs) were run separately. Results The results of principal component analysis indicated that a one-factor model fit the data well across both samples. In consideration of the weakness of some IAT items, a 17-item modified version of the IAT was proposed. Conclusions This study assessed, for the first time, the factorial structure of a modified version of an Internet-administered IAT on a sample of Internet gamers and a sample of online poker players. The scale seems appropriate for the assessment of such online behaviors. Further studies on the modified 17-item IAT version are needed. PMID:26543917

  9. Are online poker problem gamblers sensation seekers?

    PubMed

    Bonnaire, Céline; Barrault, Servane

    2018-06-01

    The purpose of this research was to examine the relationship between sensation seeking and online poker gambling in a community sample of adult online poker players, when controlling for age, gender, anxiety and depression. In total, 288 online poker gamblers were recruited. Sociodemographic data, gambling behavior (CPGI), sensation seeking (SSS), depression and anxiety (HADS) were evaluated. Problem online poker gamblers have higher sensation seeking scores (total, thrill and adventure, disinhibition and boredom susceptibility subscores) and depression scores than non-problem online poker gamblers. Being male, with total sensation seeking, disinhibition and depression scores are factors associated with online poker problem gambling. These findings are interesting in terms of harm reduction. For example, because disinhibition could lead to increased time and money spent, protective behavioral strategies like setting time and monetary limits should be encouraged in poker online gamblers. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. The online poker sub-culture: dialogues, interactions and networks.

    PubMed

    O'Leary, Killian; Carroll, Conor

    2013-12-01

    This paper examines the distinct world of online poker. It outlines the online poker eco-system, and the players which inhabit it, their distinctive attitudes and behaviors towards the game and gambling. These unique patterns of behavior have been created and sustained by the interaction of players within online poker forums. Therefore online poker forums were identified as primary mechanism within which a poker sub-culture may exist. The study conducted an extensive netnography of online poker forums. The study found that within the online poker eco-system there are forums which are elevated to sacred status amongst this online poker sub-culture. The members of these forums enact sub-cultural characteristics such as ethos of collaboration/cooperation, and a competitive hierarchy of status. In particular this paper identifies the importance of identity generation, and communities within the online poker eco-system.

  11. Predictive factors of excessive online poker playing.

    PubMed

    Hopley, Anthony A B; Nicki, Richard M

    2010-08-01

    Despite the widespread rise of online poker playing, there is a paucity of research examining potential predictors for excessive poker playing. The aim of this study was to build on recent research examining motives for Texas Hold'em play in students by determining whether predictors of other kinds of excessive gambling apply to Texas Hold'em. Impulsivity, negative mood states, dissociation, and boredom proneness have been linked to general problem gambling and may play a role in online poker. Participants of this study were self-selected online poker players (N = 179) who completed an online survey. Results revealed that participants played an average of 20 hours of online poker a week and approximately 9% of the sample was classified as a problem gambler according to the Canadian Problem Gambling Index. Problem gambling, in this sample, was uniquely predicted by time played, dissociation, boredom proneness, impulsivity, and negative affective states, namely depression, anxiety, and stress.

  12. "Don't worry, it's just poker!"--experience, self-rumination and self-reflection as determinants of decision-making in on-line poker.

    PubMed

    Palomäki, Jussi; Laakasuo, Michael; Salmela, Mikko

    2013-09-01

    On-line poker is a game of chance and skill. The construct of poker playing skill has both a technical (game strategy-related) and an emotional (emotion regulation-related) aspect. A correlational on-line study (N = 354) was conducted to assess differences in technical skills and emotional characteristics related to poker playing style between experienced and inexperienced poker players. Results suggest that, with respect to emotional characteristics, experienced poker players engage in less self-rumination and more self-reflection, as compared to inexperienced players. Experienced poker players are also able to make better decisions, by mathematical standards, in a poker decision-making environment, as assessed by two fictitious on-line poker decision-making scenarios. Furthermore, this study provides supportive evidence that experienced poker players conceptualize the construct of "luck" differently from inexperienced players. A new poker playing experience scale (PES) for accurately measuring poker playing experience is presented in this paper.

  13. Online Poker Gambling in University Students: Further Findings from an Online Survey

    ERIC Educational Resources Information Center

    Griffiths, Mark; Parke, Jonathan; Wood, Richard; Rigbye, Jane

    2010-01-01

    Online poker is one of the fastest growing forms of online gambling yet there has been relatively little research to date. This study comprised 422 online poker players (362 males and 60 females) and investigated some of the predicting factors of online poker success and problem gambling using an online questionnaire. Results showed that length of…

  14. Texas Hold 'em Online Poker: A Further Examination

    ERIC Educational Resources Information Center

    Hopley, Anthony A. B.; Dempsey, Kevin; Nicki, Richard

    2012-01-01

    Playing Texas Hold 'em Online Poker (THOP) is on the rise. However, there is relatively little research examining factors that contribute to problem gambling in poker players. The aim of this study was to extend the research findings of Hopley and Nicki (2010). The negative mood states of depression, anxiety and stress were found to be linked to…

  15. Are poker players all the same? Latent class analysis.

    PubMed

    Dufour, Magali; Brunelle, Natacha; Roy, Élise

    2015-06-01

    Poker is the gambling game that is currently gaining the most in popularity. However, there is little information on poker players' characteristics and risk factors. Furthermore, the first studies described poker players, often recruited in universities, as an homogeneous group who played in only one of the modes (land based or on the Internet). This study aims to identify, through latent class analyses, poker player subgroups. A convenience sample of 258 adult poker players was recruited across Quebec during special events or through advertising in various media. Participants filled out a series of questionnaires (Canadian Problem Gambling Index, Beck Depression, Beck Anxiety, erroneous belief and alcohol/drug consumption). The latent class analysis suggests that there are three classes of poker players. Class I (recreational poker players) includes those who have the lowest probability of engaging intensively in different game modes. Participants in class II (Internet poker players) all play poker on the Internet. This class includes the highest proportion of players who consider themselves experts or professionals. They make a living in part or in whole from poker. Class III (multiform players) includes participants with the broadest variety of poker patterns. This group is complex: these players are positioned halfway between professional and recreational players. Results indicate that poker players are not an homogeneous group identified simply on the basis of the form of poker played. The specific characteristics associated with each subgroup points to vulnerabilities that could potentially be targeted for preventive interventions.

  16. Decision-Making and Thought Processes among Poker Players

    ERIC Educational Resources Information Center

    St. Germain, Joseph; Tenenbaum, Gershon

    2011-01-01

    This study was aimed at delineating decision-making and thought processing among poker players who vary in skill-level. Forty-five participants, 15 in each group, comprised expert, intermediate, and novice poker players. They completed the Computer Poker Simulation Task (CPST) comprised of 60 hands of No-Limit Texas Hold 'Em. During the CPST, they…

  17. Beyond Chance? The Persistence of Performance in Online Poker

    PubMed Central

    Potter van Loon, Rogier J. D.; van den Assem, Martijn J.; van Dolder, Dennie

    2015-01-01

    A major issue in the widespread controversy about the legality of poker and the appropriate taxation of winnings is whether poker should be considered a game of skill or a game of chance. To inform this debate we present an analysis into the role of skill in the performance of online poker players, using a large database with hundreds of millions of player-hand observations from real money ring games at three different stakes levels. We find that players whose earlier profitability was in the top (bottom) deciles perform better (worse) and are substantially more likely to end up in the top (bottom) performance deciles of the following time period. Regression analyses of performance on historical performance and other skill-related proxies provide further evidence for persistence and predictability. Simulations point out that skill dominates chance when performance is measured over 1,500 or more hands of play. PMID:25729862

  18. Acquisition, development, and maintenance of online poker playing in a student sample.

    PubMed

    Wood, Richard T A; Griffiths, Mark D; Parke, Jonathan

    2007-06-01

    To date there has been very little empirical research into Internet gambling and none relating to the recent rise in popularity of online poker. Given that recent reports have claimed that students may be a vulnerable group, the aim of the current study was to establish basic information regarding Internet poker playing behavior among the student population, including various motivators for participation and predictors of problematic play. The study examined a self-selected sample of student online poker players using an online survey (n=422). Results showed that online poker playing was undertaken at least twice per week by a third of the participants. Almost one in five of the sample (18%) was defined as a problem gambler using the DSM-IV criteria. Findings demonstrated that problem gambling in this population was best predicted by negative mood states after playing, gender swapping whilst playing, and playing to escape from problems.

  19. "To Bluff like a Man or Fold like a Girl?" - Gender Biased Deceptive Behavior in Online Poker.

    PubMed

    Palomäki, Jussi; Yan, Jeff; Modic, David; Laakasuo, Michael

    2016-01-01

    Evolutionary psychology suggests that men are more likely than women to deceive to bolster their status and influence. Also gender perception influences deceptive behavior, which is linked to pervasive gender stereotypes: women are typically viewed as weaker and more gullible than men. We assessed bluffing in an online experiment (N = 502), where participants made decisions to bluff or not in simulated poker tasks against opponents represented by avatars. Participants bluffed on average 6% more frequently at poker tables with female-only avatars than at tables with male-only or gender mixed avatars-a highly significant effect in games involving repeated decisions. Nonetheless, participants did not believe the avatar genders affected their decisions. Males bluffed 13% more frequently than females. Unlike most economic games employed exclusively in research contexts, online poker is played for money by tens of millions of people worldwide. Thus, gender effects in bluffing have significant monetary consequences for poker players.

  20. One-Year Prospective Study on Passion and Gambling Problems in Poker Players.

    PubMed

    Morvannou, Adèle; Dufour, Magali; Brunelle, Natacha; Berbiche, Djamal; Roy, Élise

    2018-06-01

    The concept of passion is relevant to understanding gambling behaviours and gambling problems. Longitudinal studies are useful to better understand the absence and development of gambling problems; however, only one study has specifically considered poker players. Using a longitudinal design, this study aims to determine the influence, 1 year later, of two forms of passion-harmonious and obsessive-on gambling problems in poker players. A total of 116 poker players was recruited from across Quebec, Canada. The outcome variable of interest was participants' category on the Canadian Pathological Gambling Index, and the predictive variable was the Gambling Passion Scale. Multiple logistic regression analyses were conducted to identify independent risk factors of at-risk poker players 1 year later. Obsessive passion at baseline doubled the risk of gambling problems 1 year later (p < 0.01); for harmonious passion, there was no association. Number of gambling activities, drug problems, and impulsivity were also associated with at-risk gambling. This study highlights the links between obsessive passion and at-risk behaviours among poker players. It is therefore important to prevent the development of obsessive passion among poker players.

  1. Chasing losses in online poker and casino games: characteristics and game play of Internet gamblers at risk of disordered gambling.

    PubMed

    Gainsbury, Sally M; Suhonen, Niko; Saastamoinen, Jani

    2014-07-30

    Disordered Internet gambling is a psychological disorder that represents an important public health issue due to the increase in highly available and conveniently accessible Internet gambling sites. Chasing losses is one of the few observable markers of at-risk and problem gambling that may be used to detect early signs of disordered Internet gambling. This study examined loss chasing behaviour in a sample of Internet casino and poker players and the socio-demographic variables, irrational beliefs, and gambling behaviours associated with chasing losses. An online survey was completed by 10,838 Internet gamblers (58% male) from 96 countries. The results showed that Internet casino players had a greater tendency to report chasing losses than poker players and gamblers who reported chasing losses were more likely to hold irrational beliefs about gambling and spend more time and money gambling than those who reported that they were unaffected by previous losses. Gamblers who played for excitement and to win money were more likely to report chasing losses. This study is one of the largest ever studies of Internet gamblers and the results are highly significant as they provide insight into the characteristics and behaviours of gamblers using this mode of access. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Gunslingers, poker players, and chickens 1: Decision making under physical performance pressure in elite athletes.

    PubMed

    Parkin, Beth L; Warriner, Katie; Walsh, Vincent

    2017-01-01

    The cognitive skills required during sport are highly demanding; accurate decisions based on the processing of dynamic environments are made in a fraction of a second (Walsh, 2014). Optimal decision-making abilities are crucial for success in sporting competition (Bar-Eli et al., 2011; Kaya, 2014). Moreover, for the elite athlete, decision making is required under conditions of intense mental and physical pressure (Anshel and Wells, 2000), yet much of the work in this area has largely ignored the highly stressful context in which athletes operate. A number of studies have shown that conditions of elevated pressure influence athletes' decision quality (Kinrade et al., 2015; Smith et al., 2016), response times (Hepler, 2015; Smith et al., 2016) and risk taking (Pighin et al., 2015). However, almost all of this work has been undertaken in nonelite athletes and participants who do not routinely operate under conditions of high stress. Thus, there is very little known about the influence of pressure on decision making in elite athletes. This study investigated the influence of physical performance pressure on decision making in a sample of world-class elite athletes. This allowed an examination of whether findings from the previous work in nonelite athletes extend to those who routinely operate under conditions of high stress. How this work could be applied to improve insight and understanding of decision making among sport professionals is examined. We sought to introduce a categorization of decision making useful to practitioners in sport: gunslingers, poker players, and chickens. Twenty-three elite athletes who compete and have frequent success at an international level (including six Olympic medal winners) performed tasks relating to three categories of decision making under conditions of low and high physical pressure. Decision making under risk was measured with performance on the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision making under

  3. Opponent Classification in Poker

    NASA Astrophysics Data System (ADS)

    Ahmad, Muhammad Aurangzeb; Elidrisi, Mohamed

    Modeling games has a long history in the Artificial Intelligence community. Most of the games that have been considered solved in AI are perfect information games. Imperfect information games like Poker and Bridge represent a domain where there is a great deal of uncertainty involved and additional challenges with respect to modeling the behavior of the opponent etc. Techniques developed for playing imperfect games also have many real world applications like repeated online auctions, human computer interaction, opponent modeling for military applications etc. In this paper we explore different techniques for playing poker, the core of these techniques is opponent modeling via classifying the behavior of opponent according to classes provided by domain experts. We utilize windows of full observation in the game to classify the opponent. In Poker, the behavior of an opponent is classified into four standard poker-playing styles based on a subjective function.

  4. Synergistic Information Processing Encrypts Strategic Reasoning in Poker.

    PubMed

    Frey, Seth; Albino, Dominic K; Williams, Paul L

    2018-06-14

    There is a tendency in decision-making research to treat uncertainty only as a problem to be overcome. But it is also a feature that can be leveraged, particularly in social interaction. Comparing the behavior of profitable and unprofitable poker players, we reveal a strategic use of information processing that keeps decision makers unpredictable. To win at poker, a player must exploit public signals from others. But using public inputs makes it easier for an observer to reconstruct that player's strategy and predict his or her behavior. How should players trade off between exploiting profitable opportunities and remaining unexploitable themselves? Using a recent multivariate approach to information theoretic data analysis and 1.75 million hands of online two-player No-Limit Texas Hold'em, we find that the important difference between winning and losing players is not in the amount of information they process, but how they process it. In particular, winning players are better at integrative information processing-creating new information from the interaction between their cards and their opponents' signals. We argue that integrative information processing does not just produce better decisions, it makes decision-making harder for others to reverse engineer, as an expert poker player's cards act like the private key in public-key cryptography. Poker players encrypt their reasoning with the way they process information. The encryption function of integrative information processing makes it possible for players to exploit others while remaining unexploitable. By recognizing the act of information processing as a strategic behavior in its own right, we offer a detailed account of how experts use endemic uncertainty to conceal their intentions in high-stakes competitive environments, and we highlight new opportunities between cognitive science, information theory, and game theory. Copyright © 2018 Cognitive Science Society, Inc.

  5. Social and psychological challenges of poker.

    PubMed

    Siler, Kyle

    2010-09-01

    Poker is a competitive, social game of skill and luck, which presents players with numerous challenging strategic and interpersonal decisions. The adaptation of poker into a game played over the internet provides the unprecedented opportunity to quantitatively analyze extremely large numbers of hands and players. This paper analyzes roughly twenty-seven million hands played online in small-stakes, medium-stakes and high-stakes games. Using PokerTracker software, statistics are generated to (a) gauge the types of strategies utilized by players (i.e. the 'strategic demography') at each level and (b) examine the various payoffs associated with different strategies at varying levels of play. The results show that competitive edges attenuate as one moves up levels, and tight-aggressive strategies--which tend to be the most remunerative--become more prevalent. Further, payoffs for different combinations of cards, varies between levels, showing how strategic payoffs are derived from competitive interactions. Smaller-stakes players also have more difficulty appropriately weighting incentive structures with frequent small gains and occasional large losses. Consequently, the relationship between winning a large proportion of hands and profitability is negative, and is strongest in small-stakes games. These variations reveal a meta-game of rationality and psychology which underlies the card game. Adopting risk-neutrality to maximize expected value, aggression and appropriate mental accounting, are cognitive burdens on players, and underpin the rationality work--reconfiguring of personal preferences and goals--players engage into be competitive, and maximize their winning and profit chances.

  6. Determinants of internet poker adoption.

    PubMed

    Philander, Kahlil S; Abarbanel, B Lillian

    2014-09-01

    In nearly all jurisdictions, adoption of a new form of gambling has been a controversial and contentious subject. Online gambling has been no different, though there are many aspects that affect online gambling that do not appear in the brick and mortar environment. This study seeks to identify whether demographic, economic, political, technological, and/or sociological determinants contribute to online poker gambling adoption. A theoretical discussion of these categories' importance to online poker is provided and exploratory empirical analysis is used to examine their potential validity. The analysis revealed support for all of the proposed categories of variables thought to be predictive of online gambling legality.

  7. Poker as a skill game: rational versus irrational behaviors

    NASA Astrophysics Data System (ADS)

    Javarone, Marco Alberto

    2015-03-01

    In many countries poker is one of the most popular card games. Although each variant of poker has its own rules, all involve the use of money to make the challenge meaningful. Nowadays, in the collective consciousness, some variants of poker are referred to as games of skill, others as gambling. A poker table can be viewed as a psychology lab, where human behavior can be observed and quantified. This work provides a preliminary analysis of the role of rationality in poker games, using a stylized version of Texas Hold'em. In particular, we compare the performance of two different kinds of players, i.e. rational versus irrational players, during a poker tournament. Results show that these behaviors (i.e. rationality and irrationality) affect both the outcomes of challenges and the way poker should be classified.

  8. Voluntary limit setting and player choice in most intense online gamblers: an empirical study of gambling behaviour.

    PubMed

    Auer, Michael; Griffiths, Mark D

    2013-12-01

    Social responsibility in gambling has become a major issue for the gaming industry. The possibility for online gamblers to set voluntary time and money limits are a social responsibility practice that is now widespread among online gaming operators. The main issue concerns whether the voluntary setting of such limits has any positive impact on subsequent gambling behaviour and whether such measures are of help to problem gamblers. In this paper, this issue is examined through data collected from a representative random sample of 100,000 players who gambled on the win2day gambling website. When opening an account at the win2day site, there is a mandatory requirement for all players to set time and cash-in limits (that cannot exceed 800 per week). During a 3-month period, all voluntary time and/or money limit setting behaviour by a subsample of online gamblers (n = 5,000) within this mandatory framework was tracked and recorded for subsequent data analysis. From the 5,000 gamblers, the 10 % most intense players (as measured by theoretical loss) were further investigated. Voluntary spending limits had the highest significant effect on subsequent monetary spending among casino and lottery gamblers. Monetary spending among poker players significantly decreased after setting a voluntary time limit. The highest significant decrease in playing duration was among poker players after setting a voluntary playing duration limit. The results of the study demonstrated that voluntary limit setting had a specific and significant effect on the studied gamblers. Therefore, voluntary limits appear to show an appropriate effect in the desired target group (i.e., the most gaming intense players).

  9. Exploring Online Game Players' Flow Experiences and Positive Affect

    ERIC Educational Resources Information Center

    Chiang, Yu-Tzu; Lin, Sunny S. J.; Cheng, Chao-Yang; Liu, Eric Zhi-Feng

    2011-01-01

    The authors conducted two studies to explore online game players' flow experiences and positive affect. Our findings indicated that online game are capable of evoking flow experiences and positive affect, and games of violent or nonviolent type may not arouse players' aggression. The players could be placed into four flow conditions: flow,…

  10. Is poker a game of skill or chance? A quasi-experimental study.

    PubMed

    Meyer, Gerhard; von Meduna, Marc; Brosowski, Tim; Hayer, Tobias

    2013-09-01

    Due to intensive marketing and the rapid growth of online gambling, poker currently enjoys great popularity among large sections of the population. Although poker is legally a game of chance in most countries, some (particularly operators of private poker web sites) argue that it should be regarded as a game of skill or sport because the outcome of the game primarily depends on individual aptitude and skill. The available findings indicate that skill plays a meaningful role; however, serious methodological weaknesses and the absence of reliable information regarding the relative importance of chance and skill considerably limit the validity of extant research. Adopting a quasi-experimental approach, the present study examined the extent to which the influence of poker playing skill was more important than card distribution. Three average players and three experts sat down at a six-player table and played 60 computer-based hands of the poker variant "Texas Hold'em" for money. In each hand, one of the average players and one expert received (a) better-than-average cards (winner's box), (b) average cards (neutral box) and (c) worse-than-average cards (loser's box). The standardized manipulation of the card distribution controlled the factor of chance to determine differences in performance between the average and expert groups. Overall, 150 individuals participated in a "fixed-limit" game variant, and 150 individuals participated in a "no-limit" game variant. ANOVA results showed that experts did not outperform average players in terms of final cash balance. Rather, card distribution was the decisive factor for successful poker playing. However, expert players were better able to minimize losses when confronted with disadvantageous conditions (i.e., worse-than-average cards). No significant differences were observed between the game variants. Furthermore, supplementary analyses confirm differential game-related actions dependent on the card distribution, player status

  11. Internet poker websites and pathological gambling prevention policy.

    PubMed

    Khazaal, Yasser; Chatton, Anne; Bouvard, Audrey; Khiari, Hiba; Achab, Sophia; Zullino, Daniele

    2013-03-01

    Despite the widespread increase in online poker playing and the risk related to excessive poker playing, research on online poker websites is still lacking with regard to pathological gambling prevention strategies offered by the websites. The aim of the present study was to assess the pathological gambling-related prevention strategies of online poker websites. Two keywords ("poker" and "poker help") were entered into two popular World Wide Web search engines. The first 20 links related to French and English online poker websites were assessed. Seventy-four websites were assessed with a standardized tool designed to rate sites on the basis of accountability, interactivity, prevention strategies, marketing, and messages related to poker strategies. Prevention strategies appeared to be lacking. Whereas a substantial proportion of the websites offered incitation to gambling such as betting "tips," few sites offered strategies to prevent or address problem gambling. Furthermore, strategies related to poker, such as probability estimation, were mostly reported without acknowledging their limitations. Results of this study suggest that more adequate prevention strategies for risky gambling should be developed for online poker.

  12. Personality traits and life satisfaction among online game players.

    PubMed

    Chen, Lily Shui-Lien; Tu, Hill Hung-Jen; Wang, Edward Shih-Tse

    2008-04-01

    The DFC Intelligence predicts worldwide online game revenues will reach $9.8 billion by 2009, making online gaming a mainstream recreational activity. Understanding online game player personality traits is therefore important. This study researches the relationship between personality traits and life satisfaction in online game players. Taipei, Taiwan, is the study location, with questionnaire surveys conducted in cyber cafe shops. Multiple regression analysis studies the causal relationship between personality traits and life satisfaction in online game players. The result shows that neuroticism has significant negative influence on life satisfaction. Both openness and conscientiousness have significant positive influence on life satisfaction. Finally, implications for leisure practice and further research are discussed.

  13. Analyzing online game players: from materialism and motivation to attitude.

    PubMed

    Chang, Ju-Hui; Zhang, Hongxia

    2008-12-01

    The online game market has been growing rapidly and has received an increasing amount of attention in recent years. The results of a survey conducted in China to explore online game players' attitude formation reveal that (a) the online game player's level of materialism positively influences the motivation for playing, (b) motivation positively influences attitude toward online games, and (c) motivation fully mediates the effects of materialism on attitude.

  14. An examination of participation in online gambling activities and the relationship with problem gambling.

    PubMed

    McCormack, Abby; Shorter, Gillian W; Griffiths, Mark D

    2013-03-01

    Background and aims Online gambling participation is increasing rapidly, with relatively little research about the possible effects of different gambling activities on problem gambling behaviour. The aim of this exploratory study was to examine the participation in online gambling activities and the relationship with problem gambling among an international sample of online gamblers. Methods An online gambling survey was posted on 32 international gambling websites and resulted in 1,119 respondents over a four-month period. Results Poker was the most popular gambling activity online. A number of online activities were associated with problem gambling, including: roulette, poker, horse race betting, sports betting, spread betting and fruit (slot) machines. Not surprisingly, those that gambled on these activities regularly (except poker) were more likely to be a problem gambler, however, what is interesting is that the reverse is true for poker players; those that gambled regularly on poker were less likely to be a problem gambler compared to the non-regular poker players. The majority of the players also gambled offline, but there was no relationship between problem gambling and whether or not a person also gambled offline. Discussion Problem gambling is associated more with certain online gambling activities than others, and those gambling on two or more activities online were more likely to be a problem gambler. Conclusion This paper can help explain the impact different online gambling activities may have on gambling behaviour. Consideration needs to be given to the gambling activity when developing and implementing treatment programmes.

  15. Time distortion for expert and novice online game players.

    PubMed

    Rau, Pei-Luen Patrick; Peng, Shu-Yun; Yang, Chin-Chow

    2006-08-01

    Online game addiction is a new mental disorder. This disorder is difficult to describe because of its comprehensive nature. Many online game players have problems controlling their playing time. They cannot stop playing a game that they enjoy. This research surveyed the past literature on "flow" and time disorder theory. A time distortion experiment was conducted. This research invited 64 children, teenagers, and young adults to investigate player skill and playing time effects on online game break-off. The playing experience and degree of time distortion were measured and analyzed. The results showed that both novice and expert online game players were subject to time distortion. The participants had difficulty breaking off from the game without intrusion by others in the real world. This research also suggests eight questions for self-evaluation for online game addiction.

  16. Is poker a skill game? New insights from statistical physics

    NASA Astrophysics Data System (ADS)

    Javarone, Marco Alberto

    2015-06-01

    During last years poker has gained a lot of prestige in several countries and, besides being one of the most famous card games, it represents a modern challenge for scientists belonging to different communities, spanning from artificial intelligence to physics and from psychology to mathematics. Unlike games like chess, the task of classifying the nature of poker (i.e., as “skill game” or gambling) seems really hard and it also constitutes a current problem, whose solution has several implications. In general, gambling offers equal winning probabilities both to rational players (i.e., those that use a strategy) and to irrational ones (i.e., those without a strategy). Therefore, in order to uncover the nature of poker, a viable way is comparing performances of rational vs. irrational players during a series of challenges. Recently, a work on this topic revealed that rationality is a fundamental ingredient to succeed in poker tournaments. In this study we analyze a simple model of poker challenges by a statistical physics approach, with the aim to uncover the nature of this game. As main result we found that, under particular conditions, few irrational players can turn poker into gambling. Therefore, although rationality is a key ingredient to succeed in poker, also the format of challenges has an important role in these dynamics, as it can strongly influence the underlying nature of the game. The importance of our results lies on the related implications, as for instance in identifying the limits within which poker can be considered as a “skill game” and, as a consequence, which kind of format must be chosen to devise algorithms able to face humans.

  17. Online data collection from video game players: methodological issues.

    PubMed

    Wood, Richard T A; Griffiths, Mark D; Eatough, Virginia

    2004-10-01

    The paper outlines the advantages and disadvantages of using the Internet to collect data concerning both online and offline gamers. Drawing from experience of a number of studies carried out online by the authors and by reviewing the available literature, the authors discuss the main issues concerning data collected from video game players. The paper examines a number of areas, including recruiting and utilizing participants, validity, suitable methods of data collection (i.e., questionnaire studies, online tests, participant observation, online interviews), and ethical issues. It is concluded that online research methods can be a useful way of examining the psychosocial aspects of video game playing.

  18. Player guild dynamics and evolution in massively multiplayer online games.

    PubMed

    Chen, Chien-Hsun; Sun, Chuen-Tsai; Hsieh, Jilung

    2008-06-01

    In the latest versions of massively multiplayer online games (MMOGs), developers have purposefully made guilds part of game environments. Guilds represent a powerful method for giving players a sense of online community, but there is little quantitative data on guild dynamics. To address this topic, we took advantage of a feature found in one of today's most popular MMOGs (World of Warcraft) to collect in-game data: user interfaces that players can modify and refine. In addition to collecting data on in-game player activities, we used this feature to observe and investigate how players join and leave guilds. Data were analyzed for the purpose of identifying factors that propel game-world guild dynamics and evolution. After collecting data for 641,805 avatars on 62 Taiwanese World of Warcraft game servers between February 10 and April 10, 2006, we created five guild type categories (small, large, elite, newbie, and unstable) that have different meanings in terms of in-game group dynamics. By viewing players as the most important resource affecting guild life cycles, it is possible to analyze game worlds as ecosystems consisting of evolving guilds and to study how guild life cycles reflect game world characteristics.

  19. How to know and choose online games: differences between current and potential players.

    PubMed

    Teng, Ching-I; Lo, Shao-Kang; Wang, Pe-Cheng

    2007-12-01

    This study investigated how different adolescent players acquire game information and the criteria they use in choosing online games and found that (1) current players generally use comprehensive information sources more than potential players do; (2) current players rely on free trials and smooth display of motion graphics as choice criteria more than potential players do; (3) potential players rely on the look of advertisements more than current players do; (4) both current and potential players most likely use word-of-mouth and gaming programs on TV as information sources; and (5) endorser attractiveness is ranked the least important among six choice criteria by both current and potential players.

  20. Emotional and Social Factors influence Poker Decision Making Accuracy.

    PubMed

    Laakasuo, Michael; Palomäki, Jussi; Salmela, Mikko

    2015-09-01

    Poker is a social game, where success depends on both game strategic knowledge and emotion regulation abilities. Thus, poker provides a productive environment for studying the effects of emotional and social factors on micro-economic decision making. Previous research indicates that experiencing negative emotions, such as moral anger, reduces mathematical accuracy in poker decision making. Furthermore, various social aspects of the game—such as losing against "bad players" due to "bad luck"—seem to fuel these emotional states. We designed an Internet-based experiment, where participants' (N = 459) mathematical accuracy in five different poker decision making tasks were assessed. In addition, we manipulated the emotional and social conditions under which the tasks were presented, in a 2 × 2 experimental setup: (1) Anger versus neutral emotional state—participants were primed either with an anger-inducing, or emotionally neutral story, and (2) Social cue versus non-social cue—during the tasks, either an image of a pair of human eyes was "following" the mouse cursor, or an image of a black moving box was presented. The results showed that anger reduced mathematical accuracy of decision making only when participants were "being watched" by a pair of moving eyes. Experienced poker players made mathematically more accurate decisions than inexperienced ones. The results contribute to current understanding on how emotional and social factors influence decision making accuracy in economic games.

  1. Effects of Testosterone Administration on Strategic Gambling in Poker Play.

    PubMed

    van Honk, Jack; Will, Geert-Jan; Terburg, David; Raub, Werner; Eisenegger, Christoph; Buskens, Vincent

    2016-01-04

    Testosterone has been associated with economically egoistic and materialistic behaviors, but -defensibly driven by reputable status seeking- also with economically fair, generous and cooperative behaviors. Problematically, social status and economic resources are inextricably intertwined in humans, thus testosterone's primal motives are concealed. We critically addressed this issue by performing a placebo-controlled single-dose testosterone administration in young women, who played a game of bluff poker wherein concerns for status and resources collide. The profit-maximizing strategy in this game is to mislead the other players by bluffing randomly (independent of strength of the hand), thus also when holding very poor cards (cold bluffing). The profit-maximizing strategy also dictates the players in this poker game to never call the other players' bluffs. For reputable-status seeking these materialistic strategies are disadvantageous; firstly, being caught cold bluffing damages one's reputation by revealing deceptive intent, and secondly, not calling the other players' bluffs signals submission in blindly tolerating deception. Here we show that testosterone administration in this game of bluff poker significantly reduces random bluffing, as well as cold bluffing, while significantly increasing calling. Our data suggest that testosterone in humans primarily motivates for reputable-status seeking, even when this elicits behaviors that are economically disadvantageous.

  2. Does trust promote more teamwork? Modeling online game players' teamwork using team experience as a moderator.

    PubMed

    Lee, Chun-Chia; Chang, Jen-Wei

    2013-11-01

    The need for teamwork has grown significantly in today's organizations. Especially for online game communities, teamwork is an important means of online game players' engagement. This study aims to investigate the impacts of trust on players' teamwork with affective commitment and normative commitment as mediators. Furthermore, this research includes team experience as a moderator to compare the difference between different player groups. A model was proposed and tested on 296 online game players' data using structural equation modeling. Findings revealed that team experience moderated the relationship between trust and teamwork. The results indicated that trust promotes more teamwork only for players with high experience through affective commitment than those who with low experience. Implications of the findings are discussed.

  3. Hack-proof Synchronization Protocol for Multi-player Online Games

    NASA Astrophysics Data System (ADS)

    Fung, Yeung Siu; Lui, John C. S.

    Modern multi-player online games are popular and attractive because they provide a sense of virtual world experience to users: players can interact with each other on the Internet but perceive a local area network responsiveness. To make this possible, most modern multi-player online games use similar networking architecture that aims to hide the effects of network latency, packet loss, and high variance of delay from players. Because real-time interactivity is a crucial feature from a player's point of view, any delay perceived by a player can affect his/her performance [16]. Therefore, the game client must be able to run and accept new user commands continuously regardless of the condition of the underlying communication channel, and that it will not stop responding because of waiting for update packets from other players. To make this possible, multi-player online games typically use protocols based on "dead-reckoning" [5, 6, 9] which allows loose synchronization between players.

  4. Effects of Testosterone Administration on Strategic Gambling in Poker Play

    PubMed Central

    van Honk, Jack; Will, Geert-Jan; Terburg, David; Raub, Werner; Eisenegger, Christoph; Buskens, Vincent

    2016-01-01

    Testosterone has been associated with economically egoistic and materialistic behaviors, but -defensibly driven by reputable status seeking- also with economically fair, generous and cooperative behaviors. Problematically, social status and economic resources are inextricably intertwined in humans, thus testosterone’s primal motives are concealed. We critically addressed this issue by performing a placebo-controlled single-dose testosterone administration in young women, who played a game of bluff poker wherein concerns for status and resources collide. The profit-maximizing strategy in this game is to mislead the other players by bluffing randomly (independent of strength of the hand), thus also when holding very poor cards (cold bluffing). The profit-maximizing strategy also dictates the players in this poker game to never call the other players’ bluffs. For reputable-status seeking these materialistic strategies are disadvantageous; firstly, being caught cold bluffing damages one’s reputation by revealing deceptive intent, and secondly, not calling the other players’ bluffs signals submission in blindly tolerating deception. Here we show that testosterone administration in this game of bluff poker significantly reduces random bluffing, as well as cold bluffing, while significantly increasing calling. Our data suggest that testosterone in humans primarily motivates for reputable-status seeking, even when this elicits behaviors that are economically disadvantageous. PMID:26727636

  5. DeepStack: Expert-level artificial intelligence in heads-up no-limit poker.

    PubMed

    Moravčík, Matej; Schmid, Martin; Burch, Neil; Lisý, Viliam; Morrill, Dustin; Bard, Nolan; Davis, Trevor; Waugh, Kevin; Johanson, Michael; Bowling, Michael

    2017-05-05

    Artificial intelligence has seen several breakthroughs in recent years, with games often serving as milestones. A common feature of these games is that players have perfect information. Poker, the quintessential game of imperfect information, is a long-standing challenge problem in artificial intelligence. We introduce DeepStack, an algorithm for imperfect-information settings. It combines recursive reasoning to handle information asymmetry, decomposition to focus computation on the relevant decision, and a form of intuition that is automatically learned from self-play using deep learning. In a study involving 44,000 hands of poker, DeepStack defeated, with statistical significance, professional poker players in heads-up no-limit Texas hold'em. The approach is theoretically sound and is shown to produce strategies that are more difficult to exploit than prior approaches. Copyright © 2017, American Association for the Advancement of Science.

  6. Selling Internet Gambling: Advertising, New Media and the Content of Poker Promotion

    ERIC Educational Resources Information Center

    McMullan, John L.; Kervin, Melissa

    2012-01-01

    This study examines the web design and engineering, advertising and marketing, and pedagogical features present at a random sample of 71 international poker sites obtained from the Casino City directory in the summer of 2009. We coded for 22 variables related to access, appeal, player protection, customer services, on-site security, use of images,…

  7. Gambling Motives: Do They Explain Cognitive Distortions in Male Poker Gamblers?

    PubMed

    Mathieu, Sasha; Barrault, Servane; Brunault, Paul; Varescon, Isabelle

    2018-03-01

    Gambling behavior is partly the result of varied motivations leading individuals to participate in gambling activities. Specific motivational profiles are found in gamblers, and gambling motives are closely linked to the development of cognitive distortions. This cross-sectional study aimed to predict cognitive distortions from gambling motives in poker players. The population was recruited in online gambling forums. Participants reported gambling at least once a week. Data included sociodemographic characteristics, the South Oaks Gambling Screen, the Gambling Motives Questionnaire-Financial and the Gambling-Related Cognition Scale. This study was conducted on 259 male poker gamblers (aged 18-69 years, 14.3% probable pathological gamblers). Univariate analyses showed that cognitive distortions were independently predicted by overall gambling motives (34.8%) and problem gambling (22.4%) (p < .05). The multivariate model, including these two variables, explained 39.7% of cognitive distortions (p < .05). The results associated with the literature data highlight that cognitive distortions are a good discriminating factor of gambling problems, showing a close inter-relationship between gambling motives, cognitive distortions and the severity of gambling. These data are consistent with the following theoretical process model: gambling motives lead individuals to practice and repeat the gambling experience, which may lead them to develop cognitive distortions, which in turn favor problem gambling. This study opens up new research perspectives to understand better the mechanisms underlying gambling practice and has clinical implications in terms of prevention and treatment. For example, a coupled motivational and cognitive intervention focused on gambling motives/cognitive distortions could be beneficial for individuals with gambling problems.

  8. Are You an Online Team Player? A Pilot Study

    ERIC Educational Resources Information Center

    Rawlings, Melody

    2014-01-01

    The purpose of this pilot case study was to answer the following research questions: How do previous experiences affect students' attitudes toward online teamwork? When do students' attitudes toward online teamwork first develop and why? Using a social constructivist framework, a qualitative case study design was utilized to conduct an online…

  9. Interaction with the game and motivation among players of massively multiplayer online role-playing games.

    PubMed

    Fuster, Héctor; Carbonell, Xavier; Chamarro, Andrés; Oberst, Ursula

    2013-01-01

    Knowledge about users interacting with Massively Multiplayer Online Role-Playing Games (MMORPG) is fundamental in order to prevent their potential negative effects on behavior. For this reason, the present study analyzed the relationship between styles of play and motivations. An online questionnaire asking for socio-demographic details, playing style, characteristics of the game played and motivations for playing, was answered by 430 Spanish-speaking MMORPG players (45.1% males). The identified profile for players, far away from the stereotype of an adolescent, consisted in a person who mainly plays on PvP (Player versus Player) servers, choosing the type of game according to his experience. Regarding motivations, they were interested in relating with other players through the game (Socialization), in discovering the game's possibilities and development of its adventures (Exploration), to a lesser extent in leadership and prestige (Achievement) and, lastly, identification with an avatar and escape from reality (Dissociation). Although part of the reason for playing was escapism and/or stress relief, the main motivation had a social nature. We conclude that MMORPG offer an attractive environment for a broad spectrum of people, and we have not been able to confirm the stereotype of a loner avoiding reality, taking refuge in games.

  10. Increased ventral-striatal activity during monetary decision making is a marker of problem poker gambling severity.

    PubMed

    Brevers, Damien; Noël, Xavier; He, Qinghua; Melrose, James A; Bechara, Antoine

    2016-05-01

    The aim of this study was to examine the impact of different neural systems on monetary decision making in frequent poker gamblers, who vary in their degree of problem gambling. Fifteen frequent poker players, ranging from non-problem to high-problem gambling, and 15 non-gambler controls were scanned using functional magnetic resonance imaging (fMRI) while performing the Iowa Gambling Task (IGT). During IGT deck selection, between-group fMRI analyses showed that frequent poker gamblers exhibited higher ventral-striatal but lower dorsolateral prefrontal and orbitofrontal activations as compared with controls. Moreover, using functional connectivity analyses, we observed higher ventral-striatal connectivity in poker players, and in regions involved in attentional/motor control (posterior cingulate), visual (occipital gyrus) and auditory (temporal gyrus) processing. In poker gamblers, scores of problem gambling severity were positively associated with ventral-striatal activations and with the connectivity between the ventral-striatum seed and the occipital fusiform gyrus and the middle temporal gyrus. Present results are consistent with findings from recent brain imaging studies showing that gambling disorder is associated with heightened motivational-reward processes during monetary decision making, which may hamper one's ability to moderate his level of monetary risk taking. © 2015 Society for the Study of Addiction.

  11. Subjective well-being: evidence from the different personality traits of online game teenager players.

    PubMed

    Chen, Lily Shui-Lien

    2008-10-01

    This present study provides insight into the relationship between personality traits and the subjective well-being for online game teenager players in Taiwan. The questionnaire has been adopted in the cyber cafe shops in Taipei, Taiwan, and 134 usable questionnaires produced to be used for the final data analysis. The results demonstrate that Neuroticism and Agreeableness have significant negative influence and Openness has significant positive influence on subjective well-being.

  12. Problematic usage among highly-engaged players of massively multiplayer online role playing games.

    PubMed

    Peters, Christopher S; Malesky, L Alvin

    2008-08-01

    One popular facet of Internet gaming is the massively multiplayer online role playing game (MMORPG). Some individuals spend so much time playing these games that it creates problems in their lives. This study focused on players of World of Warcraft. Factor analysis revealed one factor related to problematic usage, which was correlated with amount of time played, and personality characteristics of agreeableness, conscientiousness, neuroticism, and extraversion.

  13. Strategic Style in Pared-Down Poker

    NASA Astrophysics Data System (ADS)

    Burns, Kevin

    This chapter deals with the manner of making diagnoses and decisions, called strategic style, in a gambling game called Pared-down Poker. The approach treats style as a mental mode in which choices are constrained by expected utilities. The focus is on two classes of utility, i.e., money and effort, and how cognitive styles compare to normative strategies in optimizing these utilities. The insights are applied to real-world concerns like managing the war against terror networks and assessing the risks of system failures. After "Introducing the Interactions" involved in playing poker, the contents are arranged in four sections, as follows. "Underpinnings of Utility" outlines four classes of utility and highlights the differences between them: economic utility (money), ergonomic utility (effort), informatic utility (knowledge), and aesthetic utility (pleasure). "Inference and Investment" dissects the cognitive challenges of playing poker and relates them to real-world situations of business and war, where the key tasks are inference (of cards in poker, or strength in war) and investment (of chips in poker, or force in war) to maximize expected utility. "Strategies and Styles" presents normative (optimal) approaches to inference and investment, and compares them to cognitive heuristics by which people play poker--focusing on Bayesian methods and how they differ from human styles. The normative strategy is then pitted against cognitive styles in head-to-head tournaments, and tournaments are also held between different styles. The results show that style is ergonomically efficient and economically effective, i.e., style is smart. "Applying the Analysis" explores how style spaces, of the sort used to model individual behavior in Pared-down Poker, might also be applied to real-world problems where organizations evolve in terror networks and accidents arise from system failures.

  14. Bridging Social Capital in Online Communities: Heterogeneity and Social Tolerance of Online Game Players in Japan

    ERIC Educational Resources Information Center

    Kobayashi, Tetsuro

    2010-01-01

    This article examines the democratic potential of online communities by investigating the influence of network heterogeneity on social tolerance in an online gaming environment. Online game communities are potential sources of bridging social capital because they tend to be relatively heterogeneous. Causal analyses are conducted using structural…

  15. Can clans protect adolescent players of massively multiplayer online games from violent behaviors?

    PubMed

    Ybarra, Michele L; Boyd, Danah

    2015-02-01

    To examine whether clan membership mediates observed associations between violent game content and externalizing behaviors among youth who play massively multiplayer online games (MMOGs). Responses from 486 11- to 18-year-olds who: live in the United States, read English, have been online at least once in the past 6 months, and have played MMOGs in the past year were examined. Generalized estimating equations were used to estimate the population-averaged incident rate ratio of aggressive, delinquent, and seriously violent behaviors among MMOG players given one's self-reported exposure to in-game content depicting violence. Twenty-nine percent of all youth respondents played MMOGs in the past year. Rates of aggressive, IRR: 1.59, 95% CI [1.11, 2.26], and delinquent, IRR: 1.44, 95% CI [0.99, 2.08], behaviors were significantly higher for MMOG players who were in clans versus not in clans. For females, clan membership attenuated but did not eliminate the observed relation between exposure to in-game violent content and both aggressive and seriously violent behavior (16% and 10% reductions in IRR, respectively); whereas for males, clan membership was largely uninfluential (i.e., less than 2% change). Clan membership is neither associated with lower rates of externalizing behaviors for youth, nor does it affect the likelihood of reporting externalizing behaviors among male players. There is some suggestion that clan membership may attenuate the concurrent association between in-game violent content and some externalizing behaviors for females.

  16. Competitive action video game players display rightward error bias during on-line video game play.

    PubMed

    Roebuck, Andrew J; Dubnyk, Aurora J B; Cochran, David; Mandryk, Regan L; Howland, John G; Harms, Victoria

    2017-09-12

    Research in asymmetrical visuospatial attention has identified a leftward bias in the general population across a variety of measures including visual attention and line-bisection tasks. In addition, increases in rightward collisions, or bumping, during visuospatial navigation tasks have been demonstrated in real world and virtual environments. However, little research has investigated these biases beyond the laboratory. The present study uses a semi-naturalistic approach and the online video game streaming service Twitch to examine navigational errors and assaults as skilled action video game players (n = 60) compete in Counter Strike: Global Offensive. This study showed a significant rightward bias in both fatal assaults and navigational errors. Analysis using the in-game ranking system as a measure of skill failed to show a relationship between bias and skill. These results suggest that a leftward visuospatial bias may exist in skilled players during online video game play. However, the present study was unable to account for some factors such as environmental symmetry and player handedness. In conclusion, video game streaming is a promising method for behavioural research in the future, however further study is required before one can determine whether these results are an artefact of the method applied, or representative of a genuine rightward bias.

  17. The Development and Evaluation of an Online Formative Assessment upon Single-Player Game in E-Learning Environment

    ERIC Educational Resources Information Center

    Tsai, Fu-Hsing

    2013-01-01

    This study developed a game-based formative assessment, called tic-tac-toe quiz for single-player version (TRIS-Q-SP), in an energy education e-learning system. This assessment game combined tic-tac-toe with online assessment, and revised the rule of tic-tac-toe for stimulating students to use online formative assessment actively. Additionally, to…

  18. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    ERIC Educational Resources Information Center

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  19. Tracing the trajectory of skill learning with a very large sample of online game players.

    PubMed

    Stafford, Tom; Dewar, Michael

    2014-02-01

    In the present study, we analyzed data from a very large sample (N = 854,064) of players of an online game involving rapid perception, decision making, and motor responding. Use of game data allowed us to connect, for the first time, rich details of training history with measures of performance from participants engaged for a sustained amount of time in effortful practice. We showed that lawful relations exist between practice amount and subsequent performance, and between practice spacing and subsequent performance. Our methodology allowed an in situ confirmation of results long established in the experimental literature on skill acquisition. Additionally, we showed that greater initial variation in performance is linked to higher subsequent performance, a result we link to the exploration/exploitation trade-off from the computational framework of reinforcement learning. We discuss the benefits and opportunities of behavioral data sets with very large sample sizes and suggest that this approach could be particularly fecund for studies of skill acquisition.

  20. Poker Flats Mine - Div. of Mining, Land, and Water

    Science.gov Websites

    Lands Coal Regulatory Program Large Mine Permits Mineral Property and Rights Mining Index Land Fishery Water Resources Factsheets Forms banner image of landscape Poker Flats Mine Home Mining Coal Regulatory Program Poker Flats Mine Mining Coal Regulatory Program Info Chickaloon Chuit Watershed Chuitna

  1. Identification and Classification of Player Types in Massive Multiplayer Online Games Using Avatar Behavior

    DTIC Science & Technology

    2011-08-01

    display specific characteristics that can be used to identify the player behind the avatar. This kind of information can be used by game companies to...bring in players. This kind of information can also be used to identify deviant behaviors such as ‘gold farming.’ Gold farming refers to the practice...unique behaviors associated with a player controlling the avatar. Some of the observable information used to identify these unique behaviors are

  2. Relationship between passion and motivation for gaming in players of massively multiplayer online role-playing games.

    PubMed

    Fuster, Héctor; Chamarro, Andrés; Carbonell, Xavier; Vallerand, Robert J

    2014-05-01

    Passion represents one of the factors involved in online video gaming. However, it remains unclear how passion affects the way gamers are involved in massively multiplayer online role-playing games (MMORPGs). The objective of the present study was to analyze the relationships between passions and motivations for online game playing. A total of 410 MMORPG players completed an online questionnaire including motives for gaming and the Passion Scale. Results indicated that passionate gamers were interested in relating with others through the game and exhibited a high degree of interest in discovery of the game, gaining leadership and prestige but little interest in escape from reality. However, some differences were observed with respect to the role of the two types of passion in the different types of motivation. Specifically, harmonious passion (HP) predicted higher levels of exploration, socialization, and achievement, in that order, while obsessive passion (OP) predicted higher levels of dissociation, achievement, and socialization. The present findings suggest that HP and OP predict different ways of engaging in MMORPGs and confirm that passion is a useful construct to help understand different motivational patterns demonstrated by MMORPG players.

  3. Excessive Use of Massively Multi-Player Online Role-Playing Games: A Pilot Study

    ERIC Educational Resources Information Center

    Hussain, Zaheer; Griffiths, Mark D.

    2009-01-01

    Massively multiplayer online role-playing games (MMORPGs) are one of the most interesting innovations in the area of online computer gaming. This pilot study set out to examine the psychological and social effects of online gaming using an online questionnaire with particular reference to excessive and "dependent" online gaming. A self-selecting…

  4. [The stakes of online gambling in Canada: a public health analysis].

    PubMed

    Papineau, Elisabeth; Leblond, Jean

    2011-01-01

    Available data show that online gamblers spend more money and dedicate more time to playing compared to gamblers who do not play online, and are more likely to experience gambling problems. Among online players, young people and poker players show higher rates of gambling problems. These observations can be explained in part by such dangerous aspects of online gambling (and also electronic gaming machines) as: immediate and convenient accessibility; ability to pay electronically and to play on credit; anonymity; and the possibility for players to consume alcohol or other drugs while playing. These are elements that could facilitate the development or the intensification of problem gambling. This being said, the public discourse about the inevitability of legalized online gambling is quite unanimous and built upon such arguments as: the imperative duty of the state to protect the population against the dangers of the online gambling black market; and the fact that the medium in itself provides excellent consumer safeguards. A growing number of legislators are following the trend and choosing to establish state control over online gambling. We present some epidemiological and analytical data that challenge some of these assertions and decisions. We recommend a better integration of public health arguments into the commercialization and marketing of online gambling.

  5. Investigating the illusion of control in mildly depressed and nondepressed individuals during video-poker play.

    PubMed

    Dannewitz, Holly; Weatherly, Jeffrey N

    2007-05-01

    Cognitive fallacies, such as the illusion of control, and psychological disorders, such as depression, may perpetuate gambling and thus contribute to problem gambling (e.g., R. Ladouceur, C. Sylvan, C. Boutin, & C. Doucet, 2002). Gender differences may exist across these variables (e.g., N. M. Petry, 2005). The authors investigated these possibilities by recruiting mildly depressed and nondepressed individuals to play jacks or better, 5-card draw, video poker. Across three poker sessions, participants were given (a) no choice of which cards to play, (b) information on the best cards to play but control over which cards were played, or (c) no information and complete control over which cards were played. The total amount of money gambled increased as control over the game decreased, but this result correlated with an increase in the rate of play. Depressed and nondepressed participants did not differ in how they gambled, but men gambled significantly more and sometimes made more mistakes during play than did women. These results question the role of the illusion of control and depression in perpetuating gambling. They also suggest that providing players information about which cards to play may indirectly promote gambling and provide insight as to why men are more prone to suffer from gambling problems than are women.

  6. Sensor emplacement testing at Poker Flat, Alaska

    NASA Astrophysics Data System (ADS)

    Reusch, A.; Beaudoin, B. C.; Anderson, K. E.; Azevedo, S.; Carothers, L.; Love, M.; Miller, P. E.; Parker, T.; Pfeifer, M.; Slad, G.; Thomas, D.; Aderhold, K.

    2013-12-01

    PASSCAL provides equipment and support for temporary seismic projects. Speed and efficiency of deployments are essential. A revised emplacement technique of putting broadband sensors directly into soil (aka direct burial) is being tested. The first phase (fall 2011 to spring 2013) comparing data quality and sensor stability between the direct burial and the traditional 1 m deep temporary PASSCAL-style vault in a wet and noisy site near San Antonio, NM is complete. Results suggest there is little or no difference in sensor performance in the relatively high-noise environment of this initial test. The second phase was started in November 2012 with the goal of making the same comparison, but at Poker Flat, Alaska, in a low-noise, high-signal, cold and wet environment, alongside a Transportable Array (TA) deployment to be used as a performance control. This location is in an accessible and secure area with very low site noise. In addition to benefiting future worldwide PASSCAL deployments, the Poker Flat experiment serves a secondary purpose of testing modifications necessary to successfully deploy and recover broadband stations in a cold environment with the limited logistics anticipated for remote Flexible Array (FA) and PASSCAL Program deployments in Alaska. Developing emplacement techniques that maintain high data quality and data return while minimizing logistics is critical to enable principle investigators to effectively and efficiently co-locate within the future TA Alaska footprint. Three Nanometrics sensors were installed in November 2012 in power-augered holes 76 cm in depth: a Trillium Compact Posthole (PH) and two Trillium 120PH units (one standard PH and one enhanced PHQ). The installations took less than 8 hours in -30°C conditions with 4 hours of usable daylight. The Compact PH and the 120PHQ are delivering data in realtime, while the 120PH is testing standalone power and data collection systems. Preliminary results compare favorably to each other as

  7. The Relationships between Online Game Player Biogenetic Traits, Playing Time, and the Genre of the Game Being Played.

    PubMed

    Kim, Jun Won; Han, Doug Hyun; Park, Doo Byung; Min, Kyung Joon; Na, Churl; Won, Su Kyung; Park, Ga Na

    2010-03-01

    Psychobiological traits may be associated with excessive Internet use. This study assessed the relationships between biogenetic traits, the amount of time spent in online game playing, and the genre of the online game being played. Five hundred sixty five students who enjoyed one of the four types of games included in this study were recruited. The types of games examined included role playing games (RPG), real-time strategy games (RTS), first person shooting games (FPS), and sports games. Behavioral patterns of game play, academic performance, and player biogenetic characteristics were assessed. The amount of time that the participants spent playing online games was significantly greater on weekends than on weekdays. On weekends, the types of games with the largest numbers of participants who played games for more than three hours were ranked as follows: RPG and FPS, RTS, and sports games. The Young's Internet Addiction Scale (YIAS)score for the RPG group was the highest among the groups of the four types of game players. The time that participants spent playing games on weekdays was negatively associated with academic performance, especially for the RPG and FPS groups. Compared with the other groups, the RPG and RTS groups had higher novelty seeking (NS) scores and self-directedness (SD) scores, respectively. Additionally, the sports game group had higher reward dependency scores than the other groups. These results suggest that RPGs may have specific factors that are attractive to latent game addicts with higher NS scores. Additionally, excessive playing of online games is related to impaired academic performance.

  8. The Relationships between Online Game Player Biogenetic Traits, Playing Time, and the Genre of the Game Being Played

    PubMed Central

    Kim, Jun Won; Park, Doo Byung; Min, Kyung Joon; Na, Churl; Won, Su Kyung; Park, Ga Na

    2010-01-01

    Objective Psychobiological traits may be associated with excessive Internet use. This study assessed the relationships between biogenetic traits, the amount of time spent in online game playing, and the genre of the online game being played. Methods Five hundred sixty five students who enjoyed one of the four types of games included in this study were recruited. The types of games examined included role playing games (RPG), real-time strategy games (RTS), first person shooting games (FPS), and sports games. Behavioral patterns of game play, academic performance, and player biogenetic characteristics were assessed. Results The amount of time that the participants spent playing online games was significantly greater on weekends than on weekdays. On weekends, the types of games with the largest numbers of participants who played games for more than three hours were ranked as follows: RPG and FPS, RTS, and sports games. The Young's Internet Addiction Scale (YIAS)score for the RPG group was the highest among the groups of the four types of game players. The time that participants spent playing games on weekdays was negatively associated with academic performance, especially for the RPG and FPS groups. Compared with the other groups, the RPG and RTS groups had higher novelty seeking (NS) scores and self-directedness (SD) scores, respectively. Additionally, the sports game group had higher reward dependency scores than the other groups. Conclusion These results suggest that RPGs may have specific factors that are attractive to latent game addicts with higher NS scores. Additionally, excessive playing of online games is related to impaired academic performance. PMID:20396428

  9. Online Solution of Two-Player Zero-Sum Games for Continuous-Time Nonlinear Systems With Completely Unknown Dynamics.

    PubMed

    Fu, Yue; Chai, Tianyou

    2016-12-01

    Regarding two-player zero-sum games of continuous-time nonlinear systems with completely unknown dynamics, this paper presents an online adaptive algorithm for learning the Nash equilibrium solution, i.e., the optimal policy pair. First, for known systems, the simultaneous policy updating algorithm (SPUA) is reviewed. A new analytical method to prove the convergence is presented. Then, based on the SPUA, without using a priori knowledge of any system dynamics, an online algorithm is proposed to simultaneously learn in real time either the minimal nonnegative solution of the Hamilton-Jacobi-Isaacs (HJI) equation or the generalized algebraic Riccati equation for linear systems as a special case, along with the optimal policy pair. The approximate solution to the HJI equation and the admissible policy pair is reexpressed by the approximation theorem. The unknown constants or weights of each are identified simultaneously by resorting to the recursive least square method. The convergence of the online algorithm to the optimal solutions is provided. A practical online algorithm is also developed. Simulation results illustrate the effectiveness of the proposed method.

  10. Are online gamblers more at risk than offline gamblers?

    PubMed

    Kairouz, Sylvia; Paradis, Catherine; Nadeau, Louise

    2012-03-01

    To characterize and compare sociodemographic profiles, game-play patterns, and level of addictive behaviors among adults who gamble online and those who do not, and to examine if, at the population level, online gambling is associated with more risky behaviors than offline gambling. Respondents were 8,456 offline gamblers and 111 online gamblers who participated in a population-based survey conducted in the province of Québec, in 2009. The study sample is representative of adult general population. There is an unequal distribution of online gambling in the population. A disproportionate number of men, young people, and students say they participate in online gambling. Poker players are overrepresented among online gamblers and gambling behaviors tend to be more excessive on the Internet. Compared with offline gamblers, online gamblers report more co-occurring risky behaviors, namely alcohol and cannabis use. Those who gamble online appear to be more at risk for gambling-related problems, but the present findings alone cannot be used as evidence for that conclusion. Future research designs could combine longitudinal data collection and multilevel analyses to provide more insight into the causal mechanisms associated with online gambling.

  11. Bonanza Creek Experimental Forest & Caribou-Poker Creeks Research Watershed.

    Treesearch

    Valerie Rapp

    2003-01-01

    Bonanza Creek Experimental Forest and Caribou-Poker Creeks Research Watershed are located in the boreal forest of interior Alaska. Research focuses on basic ecological processes, hydrology, disturbance regimes, and climate change in the boreal forest region. Interior Alaska lies between the Alaska Range to the south and the Brooks Range to the north and covers an area...

  12. Pinochle Poker: An Activity for Counting and Probability

    ERIC Educational Resources Information Center

    Wroughton, Jacqueline; Nolan, Joseph

    2012-01-01

    Understanding counting rules is challenging for students; in particular, they struggle with determining when and how to implement combinations, permutations, and the multiplication rule as tools for counting large sets and computing probability. We present an activity--using ideas from the games of poker and pinochle--designed to help students…

  13. Clausewitz: On Poker, How Today’s Leaders Can Use Poker to Better Prepare Tomorrow’s Warriors

    DTIC Science & Technology

    2007-01-01

    thing applies to combat leaders, and that is why the military could benefit by teaching poker. Rocks, Maniacs, Calling Stations and TA’s Clausewitz...much like churches around the world have done with bingo . Instead of playing for money, perhaps contestants could compete for a 3-day pass, or free

  14. Learning Outcomes and Processes in Massively Multiplayer Online Games: Exploring the Perceptions of Players

    ERIC Educational Resources Information Center

    Voulgari, Iro; Komis, Vassilis; Sampson, Demetrios G.

    2014-01-01

    Over the past decade research has recognised the learning potential of massively multiplayer online games (MMOGs). MMOGs can be used by the technology-enhanced learning research community to study and identify good educational practices that may inspire engaging, creative and motivating approaches for education and learning. To this end, in this…

  15. Brain Structures Associated with Internet Addiction Tendency in Adolescent Online Game Players

    PubMed Central

    Pan, Nannan; Yang, Yongxin; Du, Xin; Qi, Xin; Du, Guijin; Zhang, Yang; Li, Xiaodong; Zhang, Quan

    2018-01-01

    With the development of the Internet, an increasing number of adolescents play online game excessively, which leads to adverse effects on individuals and society. Previous studies have demonstrated altered gray-matter volume (GMV) in individuals with Internet gaming disorder (IGD), but the relationship between the tendency to IGD and the GMV across whole brain is still unclear in adolescents. In the present study, anatomical imaging with high resolution was performed on 67 male adolescents who played online game; and Young’s Internet addiction test (IAT) was conducted to test the tendency to IGD. FMRIB Software Library (FSL) was used to calculate the voxel-based correlations between the GMV and the IAT score after controlling for the age and years of education. The GMVs of the bilateral postcentral gyri (postCG), the bilateral precentral gyri (preCG), the right precuneus, the left posterior midcingulate cortex (pMCC), the left inferior parietal lobe (IPL), and the right middle frontal gyrus (MFG) were negatively correlated with the IAT score. The correlation still existed between the IAT score and the GMVs of the bilateral postCG, the left preCG, the left pMCC, and the right MFG after controlling for the total time of playing online game. When the participants were divided into two groups according to the IAT score, the GMVs of these IAT-related brain regions were lower in high IAT score subgroup (IAT score >50) than in low IAT score subgroup (IAT score ≤50). Our results suggested that the GMVs of brain regions involved in sensorimotor process and cognitive control were associated with the IGD tendency. These findings may lead to new targets for preventing and treating the IGD. PMID:29559931

  16. Brain Structures Associated with Internet Addiction Tendency in Adolescent Online Game Players.

    PubMed

    Pan, Nannan; Yang, Yongxin; Du, Xin; Qi, Xin; Du, Guijin; Zhang, Yang; Li, Xiaodong; Zhang, Quan

    2018-01-01

    With the development of the Internet, an increasing number of adolescents play online game excessively, which leads to adverse effects on individuals and society. Previous studies have demonstrated altered gray-matter volume (GMV) in individuals with Internet gaming disorder (IGD), but the relationship between the tendency to IGD and the GMV across whole brain is still unclear in adolescents. In the present study, anatomical imaging with high resolution was performed on 67 male adolescents who played online game; and Young's Internet addiction test (IAT) was conducted to test the tendency to IGD. FMRIB Software Library (FSL) was used to calculate the voxel-based correlations between the GMV and the IAT score after controlling for the age and years of education. The GMVs of the bilateral postcentral gyri (postCG), the bilateral precentral gyri (preCG), the right precuneus, the left posterior midcingulate cortex (pMCC), the left inferior parietal lobe (IPL), and the right middle frontal gyrus (MFG) were negatively correlated with the IAT score. The correlation still existed between the IAT score and the GMVs of the bilateral postCG, the left preCG, the left pMCC, and the right MFG after controlling for the total time of playing online game. When the participants were divided into two groups according to the IAT score, the GMVs of these IAT-related brain regions were lower in high IAT score subgroup (IAT score >50) than in low IAT score subgroup (IAT score ≤50). Our results suggested that the GMVs of brain regions involved in sensorimotor process and cognitive control were associated with the IGD tendency. These findings may lead to new targets for preventing and treating the IGD.

  17. Poker, Sports Betting, and Less Popular Alternatives: Status, Friendship Networks, and Male Adolescent Gambling

    ERIC Educational Resources Information Center

    DiCicco-Bloom, Benjamin; Romer, Daniel

    2012-01-01

    The authors argue that the recent increase in poker play among adolescent males in the United States was primarily attributable to high-status male youth who are more able to organize "informal" gambling games (e.g., poker and sports betting) than are low-status male youth who are left to gamble on "formal" games (e.g., lotteries and slot…

  18. 78 FR 40196 - National Environmental Policy Act; Sounding Rockets Program; Poker Flat Research Range

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...; Sounding Rockets Program; Poker Flat Research Range AGENCY: National Aeronautics and Space Administration... Sounding Rockets Program (SRP) at Poker Flat Research Range (PFRR), Alaska. SUMMARY: Pursuant to the... government agencies, and educational institutions have conducted suborbital rocket launches from the PFRR...

  19. 77 FR 61642 - National Environmental Policy Act; Sounding Rockets Program; Poker Flat Research Range

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ...; Sounding Rockets Program; Poker Flat Research Range AGENCY: National Aeronautics and Space Administration... Sounding Rockets Program (SRP) at Poker Flat Research Range (PFRR), Alaska. SUMMARY: Pursuant to the... educational institutions have conducted suborbital rocket launches from the PFRR. While the PFRR is owned and...

  20. Stripped-Down Poker: A Classroom Game with Signaling and Bluffing

    ERIC Educational Resources Information Center

    Reiley, David H.; Urbancic, Michael B.; Walker, Mark

    2008-01-01

    The authors present a simplified, "stripped-down" version of poker as an instructional classroom game. Although Stripped-Down Poker is extremely simple, it nevertheless provides an excellent illustration of a number of topics: signaling, bluffing, mixed strategies, the value of information, and Bayes's Rule. The authors begin with a description of…

  1. Being Mindful May Not Make You a Team Player: Does Meditation Help or Hurt Online Group Work?

    ERIC Educational Resources Information Center

    Tan, Yunzi; Molinari, Carol

    2017-01-01

    In higher education, more and more students take part in online courses that require them to engage in virtual work groups. Research has shown that online learners are likely to experience information overload and considerable challenges associated with online learning environments. These challenges are exacerbated when learners have to work as…

  2. AmeriFlux US-Prr Poker Flat Research Range Black Spruce Forest

    DOE Data Explorer

    Suzuki, Rikie [Japan Agency for Marine-Earth Science and Technology

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Prr Poker Flat Research Range Black Spruce Forest. Site Description - This site is located in a blackspruce forest within the property of the Poker Flat Research Range, University of Alaska, Fairbanks. Time-lapse image of the canopy is measured at the same time to relate flux data to satellite images.

  3. The Effectiveness Evaluation among Different Player-Matching Mechanisms in a Multi-Player Quiz Game

    ERIC Educational Resources Information Center

    Tsai, Fu-Hsing

    2016-01-01

    This study aims to investigate whether different player-matching mechanisms in educational multi-player online games (MOGs) can affect students' learning performance, enjoyment perception and gaming behaviors. Based on the multi-player quiz game, TRIS-Q, developed by Tsai, Tsai and Lin (2015) using a free player-matching (FPM) mechanism, the same…

  4. Psychological predictors of problematic involvement in massively multiplayer online role-playing games: illustration in a sample of male cybercafé players.

    PubMed

    Billieux, Joël; Chanal, Julien; Khazaal, Yasser; Rochat, Lucien; Gay, Philippe; Zullino, Daniele; Van der Linden, Martial

    2011-01-01

    Massively Multiplayer Online Role-Playing Games (MMORPGs) are video games in which a large number of players interact with one another in a persistent virtual world. MMORPGs can become problematic and result in negative outcomes in daily living (e.g. loss of control on gaming behaviors, compromised social and individual quality of life). The aim of the present study is to investigate psychological predictors of problematic involvement in MMORPGs. Fifty-four males who played MMORPGs regularly were recruited in cybercafés and screened using the UPPS Impulsive Behavior Scale (which assesses 4 facets of impulsivity) and the Motivation to Play Online Questionnaire (which assesses personal motives to play online). Negative consequences due to excessive time spent on the Internet were assessed with the Internet Addiction Test. Multiple regression analysis showed that problematic use of MMORPGs is significantly predicted by: (1) high urgency (b = 0.45), and (2) a motivation to play for immersion (b = 0.35). This study showed that, for certain individuals (who are characterized by a proneness to act rashly in emotional contexts and motivated to play to be immersed in a virtual world), involvement in MMORPGs can become problematic and engender tangible negative consequences in daily life. Copyright © 2011 S. Karger AG, Basel.

  5. In- and Out-of-Character: The Digital Literacy Practices and Emergent Information Worlds of Active Role-Players in a New Massively Multiplayer Online Role-Playing Game

    ERIC Educational Resources Information Center

    Hollister, Jonathan M.

    2016-01-01

    This dissertation explores and describes the in-character and out-of-character information worlds and digital literacy practices of role-players, those that create and enact their characters' or avatars' stories, both within and outside of WildStar, a Massively Multiplayer Online Role-Playing Game (MMORPG) (Carbine Studios, 2015). Utilizing Jaeger…

  6. Gunslingers, poker players, and chickens 2: Decision-making under physical performance pressure in subelite athletes.

    PubMed

    Parkin, Beth L; Walsh, Vincent

    2017-01-01

    Having investigated the influence of acute physical exhaustion on decision-making in world-class elite athletes in Parkin et al. (2017), here a similar method is applied to subelite athletes. These subelite athletes were enrolled on a Team GB talent development program and were undergoing training for possible Olympic competition in 4-8 years. They differ from elite athletes examined previously according to expertise and age. While considered elite (Swann et al., 2015), the subelite athletes had approximately 8 years fewer sporting experience and were yet to obtain sustained success on the international stage. Additionally, the average age of the subelite sample is 20 years; thus, they are still undergoing the behavioral, cognitive, and neuronal changes that occur during the transition from late adolescence to young adulthood (Blakemore and Robbins, 2012). Previous work has used broad definitions of elite status in sport, and as such overlooked different categories within the spectrum of elite athletes (Swann et al., 2015). Therefore it is important to consider subelite athletes as a discrete point on the developmental trajectory of elite sporting expertise. This work aims to investigate the influence of physical pressure on key indicators of decision-making in subelite athletes. It forms part of a wider project examining decision-making across different stages of the developmental trajectory in elite sport. In doing so, it aims to examine how to apply and develop psychological insights useful to an elite sporting environment. 32 subelite athletes (18 males, mean age: 20 years) participated in the study. Performance across three categories of decision-making was assessed under conditions of low and high physical pressure. Decision-making under risk was measured with performance of the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision-making under uncertainty with the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), and fast reactive responses and inhibition via the Stop Signal Reaction Time Task (SSRT; Logan, 1994). Physical exhaustion was induced via intervals of maximal exertion exercise on a wattbike. Under pressure subelite athletes showed increased risk taking for both decisions where probability outcomes were explicit (on the CGT), and those where probability outcomes were unknown (on the BART). Despite making quicker decisions under pressure, with fewer errors, on the CGT, subelite athletes showed a reduced ability to optimally adjust betting behavior according to reward and loss contingencies. Fast reactive responses to perceptual stimuli and response inhibition did not change as a result of physical pressure. Individual responses to pressure showed a negative correlation in that a decrease in reaction times on the SSRT Task under pressure was associated with an increase in risk taking on the BART. When assessing the applicability of results based on group averages to individual athletes, 17% of the sample showed an "average" response (within 1 SD of the mean) to pressure across all three decision-making tasks. Indicators of decision-making in a sample of subelite athletes are influenced by physical pressure, with a shift toward increased indiscriminate risk taking. The influence that physical pressure has on decision-making was different to that observed in world-class elite athletes; this highlights the importance of distinguishing between athletes at the elite level (Swann et al., 2015). The application of this work to a novel subgroup of elite athletes, including the implementation of a decision-making taxonomy, is discussed. © 2017 Elsevier B.V. All rights reserved.

  7. Gunslingers, poker players, and chickens 3: Decision making under mental performance pressure in junior elite athletes.

    PubMed

    Parkin, Beth L; Walsh, Vincent

    2017-01-01

    Having investigated the decision making of world class elite and subelite athletes (see Parkin and Walsh, 2017; Parkin et al., 2017), here the abilities of those at the earliest stage of entry to elite sport are examined. Junior elite athletes have undergone initial national selection and are younger than athletes examined previously (mean age 13 years). Decision making under mental pressure is explored in this sample. During performance an athlete encounters a wide array of mental pressures; these include the psychological impact of errors, negative feedback, and requirements for sustained attention in a dynamic environment (Anshel and Wells, 2000; Mellalieu et al., 2009). Such factors increase the cognitive demands of the athletes, inducing distracting anxiety-related thoughts known as rumination (Beilock and Gray, 2007). Mental pressure has been shown to reduce performance of decision-making tasks where reward and loss contingencies are explicit, with a shift toward increased risk taking (Pabst et al., 2013; Starcke et al., 2011). Mental pressure has been shown to be detrimental to decision-making speed in comparison to physical stress, highlighting the importance of considering a range of different pressures encountered by athletes (Hepler, 2015). To investigate the influence of mental pressure on key indicators of decision making in junior elite athletes. This chapter concludes a wider project examining decision making across developmental stages in elite sport. The work further explores how psychological insights can be applied in an elite sporting environment and in particular tailored to the requirements of junior athletes. Seventeen junior elite athletes (10 males, mean age: 13.80 years) enrolled on a national youth athletic development program participated in the study. Performance across three categories of decision making was assessed under conditions of low and high mental pressure. Decision making under risk was measured via the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision making under uncertainty via the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), and fast reactive responses to perceptual stimuli via the Visual Search Task (Treisman, 1982). Mental pressure was induced with the addition of a concurrent verbal memory task, used to increase cognitive load and mimic the distracting effects of anxiety-related rumination. In junior elite athletes, fast reactive responses to perceptual stimuli (on the Visual Search Task) were slower under conditions of mental pressure. For decision making under risk there was an interaction of mental pressure and gender on the amount of points gambled, under pressure there was a higher level of risk taking in male athletes compared to females. There was no influence of mental pressure on decision making under uncertainity. There were no significant correlations in the degree to which individual's responses changed under pressure across the three measures of decision making. When assessing the applicability of results based on group averages there were no junior elite athletes who showed an "average" response (within 1SD of the mean) to mental pressure across all the three decision-making tasks. Mental pressure affects decision making in a sample of junior elite athletes, with a slowing of response times, and modulations to performance of decision making under risk that have a high requirement for working memory. In relation to sport, these findings suggest that novel situations that place high cognitive demands on the athlete may be particularly influenced by mental pressure. The application of this work in junior elite athletes included the feedback of individual results and the implementation of a decision-making taxonomy. © 2017 Elsevier B.V. All rights reserved.

  8. Clausewitz: On Poker (Clausewitz was a TA). How Today’s Leaders Can Use Poker to Better Prepare Tomorrow’s Warriors

    DTIC Science & Technology

    2007-01-01

    thing applies to combat leaders, and that is why the military could benefit by teaching poker. Rocks, Maniacs, Calling Stations and TA’s Clausewitz...much like churches around the world have done with bingo . Instead of playing for money, perhaps contestants could compete for a 3-day pass, or free

  9. Effects of gender and game type on autonomic nervous system physiological parameters in long-hour online game players.

    PubMed

    Lin, Tung-Cheng

    2013-11-01

    Online game playing may induce physiological effects. However, the physical mechanisms that cause these effects remain unclear. The purpose of this study was to examine the physiological effects of long-hour online gaming from an autonomic nervous system (ANS) perspective. Heart rate variability (HRV), a valid and noninvasive electrocardiographic method widely used to investigate ANS balance, was used to measure physiological effect parameters. This study used a five-time, repeated measures, mixed factorial design. Results found that playing violent games causes significantly higher sympathetic activity and diastolic blood pressure than playing nonviolent games. Long-hour online game playing resulted in the gradual dominance of the parasympathetic nervous system due to physical exhaustion. Gaming workload was found to modulate the gender effects, with males registering significantly higher sympathetic activity and females significantly higher parasympathetic activity in the higher gaming workload group.

  10. Cue-Reactive Rationality, Visual Imagery and Volitional Control Predict Cue-Reactive Urge to Gamble in Poker-Machine Gamblers.

    PubMed

    Clark, Gavin I; Rock, Adam J; McKeith, Charles F A; Coventry, William L

    2017-09-01

    Poker-machine gamblers have been demonstrated to report increases in the urge to gamble following exposure to salient gambling cues. However, the processes which contribute to this urge to gamble remain to be understood. The present study aimed to investigate whether changes in the conscious experience of visual imagery, rationality and volitional control (over one's thoughts, images and attention) predicted changes in the urge to gamble following exposure to a gambling cue. Thirty-one regular poker-machine gamblers who reported at least low levels of problem gambling on the Problem Gambling Severity Index (PGSI), were recruited to complete an online cue-reactivity experiment. Participants completed the PGSI, the visual imagery, rationality and volitional control subscales of the Phenomenology of Consciousness Inventory (PCI), and a visual analogue scale (VAS) assessing urge to gamble. Participants completed the PCI subscales and VAS at baseline, following a neutral video cue and following a gambling video cue. Urge to gamble was found to significantly increase from neutral cue to gambling cue (while controlling for baseline urge) and this increase was predicted by PGSI score. After accounting for the effects of problem-gambling severity, cue-reactive visual imagery, rationality and volitional control significantly improved the prediction of cue-reactive urge to gamble. The small sample size and limited participant characteristic data restricts the generalizability of the findings. Nevertheless, this is the first study to demonstrate that changes in the subjective experience of visual imagery, volitional control and rationality predict changes in the urge to gamble from neutral to gambling cue. The results suggest that visual imagery, rationality and volitional control may play an important role in the experience of the urge to gamble in poker-machine gamblers.

  11. Purification and Characterization of Hemagglutinating Proteins from Poker-Chip Venus (Meretrix lusoria) and Corbicula Clam (Corbicula fluminea)

    PubMed Central

    Cheng, Chin-Fu; Hung, Shao-Wen; Chang, Yung-Chung; Chen, Ming-Hui; Chang, Chen-Hsuan; Tsou, Li-Tse; Tu, Ching-Yu; Lin, Yu-Hsing; Liu, Pan-Chen; Lin, Shiun-Long; Wang, Way-Shyan

    2012-01-01

    Hemagglutinating proteins (HAPs) were purified from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea) using gel-filtration chromatography on a Sephacryl S-300 column. The molecular weights of the HAPs obtained from Poker-chip Venus and Corbicula clam were 358 kDa and 380 kDa, respectively. Purified HAP from Poker-chip Venus yielded two subunits with molecular weights of 26 kDa and 29 kDa. However, only one HAP subunit was purified from Corbicula clam, and its molecular weight was 32 kDa. The two Poker-chip Venus HAPs possessed hemagglutinating ability (HAA) for erythrocytes of some vertebrate animal species, especially tilapia. Moreover, HAA of the HAP purified from Poker-chip Venus was higher than that of the HAP of Corbicula clam. Furthermore, Poker-chip Venus HAPs possessed better HAA at a pH higher than 7.0. When the temperature was at 4°C–10°C or the salinity was less than 0.5‰, the two Poker-chip Venus HAPs possessed better HAA compared with that of Corbicula clam. PMID:22666167

  12. Purification and characterization of hemagglutinating proteins from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea).

    PubMed

    Cheng, Chin-Fu; Hung, Shao-Wen; Chang, Yung-Chung; Chen, Ming-Hui; Chang, Chen-Hsuan; Tsou, Li-Tse; Tu, Ching-Yu; Lin, Yu-Hsing; Liu, Pan-Chen; Lin, Shiun-Long; Wang, Way-Shyan

    2012-01-01

    Hemagglutinating proteins (HAPs) were purified from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea) using gel-filtration chromatography on a Sephacryl S-300 column. The molecular weights of the HAPs obtained from Poker-chip Venus and Corbicula clam were 358 kDa and 380 kDa, respectively. Purified HAP from Poker-chip Venus yielded two subunits with molecular weights of 26 kDa and 29 kDa. However, only one HAP subunit was purified from Corbicula clam, and its molecular weight was 32 kDa. The two Poker-chip Venus HAPs possessed hemagglutinating ability (HAA) for erythrocytes of some vertebrate animal species, especially tilapia. Moreover, HAA of the HAP purified from Poker-chip Venus was higher than that of the HAP of Corbicula clam. Furthermore, Poker-chip Venus HAPs possessed better HAA at a pH higher than 7.0. When the temperature was at 4°C-10°C or the salinity was less than 0.5‰, the two Poker-chip Venus HAPs possessed better HAA compared with that of Corbicula clam.

  13. Exploring Chemical Equilibrium with Poker Chips: A General Chemistry Laboratory Exercise

    ERIC Educational Resources Information Center

    Bindel, Thomas H.

    2012-01-01

    A hands-on laboratory exercise at the general chemistry level introduces students to chemical equilibrium through a simulation that uses poker chips and rate equations. More specifically, the exercise allows students to explore reaction tables, dynamic chemical equilibrium, equilibrium constant expressions, and the equilibrium constant based on…

  14. 78 FR 40391 - Special Local Regulations; Dinghy Poker Run, Middle River; Baltimore County, Essex, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... the rule is to ensure safety of life on navigable waters of the United States during the Dinghy Poker...: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard proposes to establish special... River. These special local regulations are necessary to provide for the safety of life on navigable...

  15. Strategic Alliance Poker: Demonstrating the Importance of Complementary Resources and Trust in Strategic Alliance Management

    ERIC Educational Resources Information Center

    Reutzel, Christopher R.; Worthington, William J.; Collins, Jamie D.

    2012-01-01

    Strategic Alliance Poker (SAP) provides instructors with an opportunity to integrate the resource based view with their discussion of strategic alliances in undergraduate Strategic Management courses. Specifically, SAP provides Strategic Management instructors with an experiential exercise that can be used to illustrate the value creation…

  16. Viewers & Players

    MedlinePlus

    ... Player Play video and audio files on Apple operating systems. mov Apple iTunes Download NLM podcasts and applications. ... Player Play video and audio files on PC operating systems. mp3 wav wmz About MedlinePlus Site Map FAQs ...

  17. The Role of Habits in Massive Multiplayer Online Role-Playing Game Usage: Predicting Excessive and Problematic Gaming Through Players' Sensitivity to Situational Cues.

    PubMed

    Lukavská, Kateřina; Hrabec, Ondřej; Chrz, Vladimír

    2016-04-01

    We examined the effect of habitual regulation of massive multiplayer online role-playing game (MMORPG) playing on the problematic (addictive) usage and excessiveness of gaming (time that user spent playing weekly, per session, and in relation to his other leisure activities). We developed the approach to assess the strength of habitual regulation that was based on sensitivity to situational cues. We defined cues as real-life or in-game conditions (e.g., work to be done, activities with friends or family, need to relax, new game expansion) that usually promote gaming (proplay cues) or prevent it (contraplay cues). Using a sample of 377 MMORPG players, we analyzed relationships between variables through partial least squares path modeling. We found that proplay cues sensitivity significantly positively affected the excessiveness of gaming (playing time) as well as the occurrence of problematic usage symptoms. Conversely, contraplay cues sensitivity functioned as a protective factor from these conditions; significant negative effects were found for playing time and problematic usage. Playing time was confirmed to be a mediating variable, affected by cues sensitivity and at the same time affecting problematic usage symptoms. We obtained moderately strong coefficients of determination for both endogenous variables (R(2) = 0.28 for playing time; R(2) = 0.31 for problematic usage) suggesting that the proposed variables possess good explanatory power. Based on our results, we argue that the strength of habitual regulation within MMORPG usage has both positive and negative effects on excessive and problematic usage, which is a new and important finding within the area of Internet gaming addiction.

  18. SAM II aerosol profile measurements, Poker Flat, Alaska; July 16-19, 1979

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Chu, W. P.; Mcmaster, L. R.; Grams, G. W.; Herman, B. M.; Pepin, T. J.; Russell, P. B.; Swissler, T. J.

    1981-01-01

    SAM II satellite measurements during the July 1979 Poker Flat mission, yielded an aerosol extinction coefficient of 0.0004/km at 1.0 micron wavelength, in the region of the stratospheric aerosol mixing ratio peak (12-16 km). The stratospheric aerosol optical depth for these data, calculated from the tropopause through 30 km, is approximately 0.001. These results are consistent with the average 1979 summertime values found throughout the Arctic.

  19. Trait Mindfulness, Problem-Gambling Severity, Altered State of Awareness and Urge to Gamble in Poker-Machine Gamblers.

    PubMed

    McKeith, Charles F A; Rock, Adam J; Clark, Gavin I

    2017-06-01

    In Australia, poker-machine gamblers represent a disproportionate number of problem gamblers. To cultivate a greater understanding of the psychological mechanisms involved in poker-machine gambling, a repeated measures cue-reactivity protocol was administered. A community sample of 38 poker-machine gamblers was assessed for problem-gambling severity and trait mindfulness. Participants were also assessed regarding altered state of awareness (ASA) and urge to gamble at baseline, following a neutral cue, and following a gambling cue. Results indicated that: (a) urge to gamble significantly increased from neutral cue to gambling cue, while controlling for baseline urge; (b) cue-reactive ASA did not significantly mediate the relationship between problem-gambling severity and cue-reactive urge (from neutral cue to gambling cue); (c) trait mindfulness was significantly negatively associated with both problem-gambling severity and cue-reactive urge (i.e., from neutral cue to gambling cue, while controlling for baseline urge); and (d) trait mindfulness did not significantly moderate the effect of problem-gambling severity on cue-reactive urge (from neutral cue to gambling cue). This is the first study to demonstrate a negative association between trait mindfulness and cue-reactive urge to gamble in a population of poker-machine gamblers. Thus, this association merits further evaluation both in relation to poker-machine gambling and other gambling modalities.

  20. Differences in the Gambling Behavior of Online and Non-online Student Gamblers in a Controlled Laboratory Environment.

    PubMed

    Montes, Kevin S; Weatherly, Jeffrey N

    2017-03-01

    Although research suggests that approximately 1 in 4 college students report having gambled online, few laboratory-based studies have been conducted enlisting online student gamblers. Moreover, it is unclear the extent to which differences in gambling behavior exist between online and non-online student gamblers. The current study examined if online gamblers would play more hands, commit more errors, and wager more credits than non-online student gamblers in a controlled, laboratory environment. Online (n = 19) and non-online (n = 26) student gamblers played video poker in three separate sessions and the number of hands played, errors committed, and credits wagered were recorded. Results showed that online student gamblers played more hands and committed more errors playing video poker than non-online student gamblers. The results from the current study extend previous research by suggesting that online gamblers engage in potentially more deleterious gambling behavior (e.g., playing more hands and committing more errors) than non-online gamblers. Additional research is needed to examine differences in the gambling behavior of online and non-online gamblers in a controlled, laboratory environment.

  1. Differences in the Gambling Behavior of Online and Non-Online Student Gamblers in a Controlled Laboratory Environment

    PubMed Central

    Montes, Kevin S.; Weatherly, Jeffrey N.

    2016-01-01

    Although research suggests that approximately 1 in 4 college students report having gambled online, few laboratory-based studies have been conducted enlisting online student gamblers. Moreover, it is unclear the extent to which differences in gambling behavior exist between online and non-online student gamblers. The current study examined if online gamblers would play more hands, commit more errors, and wager more credits than non-online student gamblers in a controlled, laboratory environment. Online (n = 19) and non-online (n = 26) student gamblers played video poker in three separate sessions and the number of hands played, errors committed, and credits wagered were recorded. Results showed that online student gamblers played more hands and committed more errors playing video poker than non-online student gamblers. The results from the current study extend previous research by suggesting that online gamblers engage in potentially more deleterious gambling behavior (e.g., playing more hands and committing more errors) than non-online gamblers. Additional research is needed to examine differences in the gambling behavior of online and non-online gamblers in a controlled, laboratory environment. PMID:27106027

  2. Mesospheric momentum fluxes observed by the MST radar at Poker Flat, Alaska

    NASA Technical Reports Server (NTRS)

    Wang, Ding-Yi; Fritts, David C.

    1990-01-01

    An analysis of the wave motions observed with the Poker Flat MST radar during the winter, summer, and fall of 1986 is presented. Monthly and daily mean winds, momentum fluxes, and velocity variances are investigated in detail. While several features are in agreement with previous measurements, some significant differences also are found to exist in the observations. Monthly mean horizontal winds between 82 and 89 km have amplitudes of 20-40 m/s westward and 10-25 m/s southward in July and August. In fall and winter, the horizontal winds between 58 and 75 km are weaker and essentially eastward.

  3. Inducing Attitude Change toward Online Gaming among Adolescent Players Based on Dissonance Theory: The Role of Threats and Justification of Effort

    ERIC Educational Resources Information Center

    Wan, Chin-Sheng; Chiou, Wen-Bin

    2010-01-01

    The negative impact of online gaming on adolescents has received much attention. The question of how to reduce their pathological use of online gaming is a critical issue. Based on the concept of external justification in dissonance theory, this experimental study aimed to examine whether severity of threat and justification of effort would impact…

  4. Superhuman AI for heads-up no-limit poker: Libratus beats top professionals.

    PubMed

    Brown, Noam; Sandholm, Tuomas

    2018-01-26

    No-limit Texas hold'em is the most popular form of poker. Despite artificial intelligence (AI) successes in perfect-information games, the private information and massive game tree have made no-limit poker difficult to tackle. We present Libratus, an AI that, in a 120,000-hand competition, defeated four top human specialist professionals in heads-up no-limit Texas hold'em, the leading benchmark and long-standing challenge problem in imperfect-information game solving. Our game-theoretic approach features application-independent techniques: an algorithm for computing a blueprint for the overall strategy, an algorithm that fleshes out the details of the strategy for subgames that are reached during play, and a self-improver algorithm that fixes potential weaknesses that opponents have identified in the blueprint strategy. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  5. Exploring Stereotypical Perceptions of Female Players in Digital Gaming Contexts.

    PubMed

    Kaye, Linda K; Gresty, Claire E; Stubbs-Ennis, Natasha

    2017-12-01

    Gender stereotypes are still reported to exist in digital gaming contexts, despite the fact that participation of females is relatively equal to that of males. The current research explored a number of factors and their impact upon stereotypical perceptions and attitudes toward female players. This included avatar gender, gender identity by gaming context, as well as more general gender-role beliefs. We undertook two studies, each utilizing an online questionnaire targeted toward online players. Study 1 recruited online gamers (N = 489) and compared competence perceptions of players, which varied by player gender (male, female) and avatar gender (male, female), whereby four conditions were established. Overall, player competence was perceived to be highest when male avatars were used, specifically when female players were depicted in this way. Study 2 explored the relationships between male social identity and gender-role beliefs, with sexist attitudes in gaming, and whether this varied by gaming context (massively multiplayer online [MMO] vs. first-person shooter [FPS]). Male online gamers (N = 193) were recruited, of which 112 were MMO players, and 81 were FPS players. It was found that identifying as male social identity was not related to sexist attitudes in either gaming context. However, more general gender-role beliefs were related to sexist attitudes. The findings indicate that although certain stereotypes exist (e.g., competence perceptions), these are not necessarily harvested by players' identities within communities, but may derive through more operational functions such as avatar gender.

  6. Evidence of gravity wave-tidal interaction observed near the summer mesopause at Poker Flat, Alaska

    NASA Technical Reports Server (NTRS)

    Wang, Ding-Yi; Fritts, David C.

    1991-01-01

    An analysis of gravity wave-tidal interaction observed near the mesopause by the MST radar at Poker Flat in July of 1986 is presented. The observations revealed daily mean wind maxima of about 60 m/sec westward and 20 m/sec southward with daily mean momentum fluxes, contributed by gravity waves with periods less than 1 hour of 4-5 sq m/sec sq eastward and 1-2 sq m/sec sq northward. Considerable hourly height variability was found to exist for both winds and momentum fluxes. A significant modulation of the fluxes by tidal winds was observed, characterized by out-of-phase correlations over a number of heights.

  7. The Influence of an Educational Course on Language Expression and Treatment of Gaming Addiction for Massive Multiplayer Online Role-Playing Game (MMORPG) Players

    ERIC Educational Resources Information Center

    Kim, Pyoung Won; Kim, Seo Young; Shim, Miseon; Im, Chang-Hwan; Shon, Young-Min

    2013-01-01

    Addiction to Massive Multiple Online Role-Playing Games (MMORPGs) among juveniles has become a serious problem in Korea and has led to legislation prohibiting juveniles from playing games after midnight. One key factor in gaming addiction is the so-called narrative, or story, gamers create for themselves while playing. This study investigated how…

  8. Neurobiological correlates of physical self-concept and self-identification with avatars in addicted players of Massively Multiplayer Online Role-Playing Games (MMORPGs).

    PubMed

    Leménager, Tagrid; Dieter, Julia; Hill, Holger; Koopmann, Anne; Reinhard, Iris; Sell, Madlen; Kiefer, Falk; Vollstädt-Klein, Sabine; Mann, Karl

    2014-12-01

    MMORPG addiction has been associated with self-concept impairments and increased identification with the own avatar. Yet, the underlying neurobiological mechanisms of self-identification with avatars, especially reflected in the left angular gyrus (AG), have only been assessed in regular gamers. Therefore, the study aims to examine neurobiological processes in addicted MMORPG players while evaluating their own and their personal avatar's body image (physical self-concept). Sixteen addicted and seventeen non-addicted gamers underwent functional Magnetic Resonance Imaging (fMRI) while viewing images of themselves, their own avatar and unfamiliar persons. The Body Image Questionnaire (FKB-20) and Visual Analog Scales (VAS) assessing the degree of attractiveness, sympathy and gender identity of the self, of the avatar as well as of the unfamiliar persons were applied. Addicts showed a significantly extended negative body image and lower gender identity levels as well as decreased bilateral brain activations in the AG and the middle occipital gyrus during self-perception. They further exhibited higher activations in the left AG during avatar-perception. Regression analyses in the overall group and in addicted gamers indicated a significant positive correlation between gender identity and brain activation in the left AG during self-perception. Our results confirm addicted MMORPG players to have physical self-concept deficits which may be related to hypoactivations in the AG. The findings further indicate addicted gamers to have a tendency to identify themselves easier with their own avatar than with their real self. Lower gender identity levels might be associated with physical self-concept deficits in MMORPG addiction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Use of behavioral biometrics in intrusion detection and online gaming

    NASA Astrophysics Data System (ADS)

    Yampolskiy, Roman V.; Govindaraju, Venu

    2006-04-01

    Behavior based intrusion detection is a frequently used approach for insuring network security. We expend behavior based intrusion detection approach to a new domain of game networks. Specifically, our research shows that a unique behavioral biometric can be generated based on the strategy used by an individual to play a game. We wrote software capable of automatically extracting behavioral profiles for each player in a game of Poker. Once a behavioral signature is generated for a player, it is continuously compared against player's current actions. Any significant deviations in behavior are reported to the game server administrator as potential security breaches. Our algorithm addresses a well-known problem of user verification and can be re-applied to the fields beyond game networks, such as operating systems and non-game networks security.

  10. Cultures of Trust: Effects of Avatar Faces and Reputation Scores on German and Arab Players in an Online Trust-Game

    PubMed Central

    Bente, Gary; Dratsch, Thomas; Kaspar, Kai; Häßler, Tabea; Bungard, Oliver; Al-Issa, Ahmad

    2014-01-01

    Reputation systems as well as seller depictions (photos; avatars) have been shown to reduce buyer uncertainty and to foster trust in online trading. With the emergence of globalized e-markets, it remains an urgent question whether these mechanisms, found to be effective for Western cultures, also apply to other cultures. Hypothesizing that members of collectivistic cultures in contrast to those of individualistic cultures would rely more on visual social cues (seller faces) than on factual information (reputation scores), we compared buying decisions of Arab and German participants in an experimental trust game. Photo-realistic avatars were used instead of photos to control facial features and expressions. The results revealed significant main effects for both reputation scores and avatar faces. Moreover, both variables significantly affected the purchase behavior of Arab as well as German buyers, suggesting cross-cultural universals in the processing of trust cues. The results have implications for future cross-cultural studies in e-commerce as well as the design of online markets and shared virtual environments. PMID:24901696

  11. Cultures of trust: effects of avatar faces and reputation scores on German and Arab players in an online trust-game.

    PubMed

    Bente, Gary; Dratsch, Thomas; Kaspar, Kai; Häβler, Tabea; Bungard, Oliver; Al-Issa, Ahmad

    2014-01-01

    Reputation systems as well as seller depictions (photos; avatars) have been shown to reduce buyer uncertainty and to foster trust in online trading. With the emergence of globalized e-markets, it remains an urgent question whether these mechanisms, found to be effective for Western cultures, also apply to other cultures. Hypothesizing that members of collectivistic cultures in contrast to those of individualistic cultures would rely more on visual social cues (seller faces) than on factual information (reputation scores), we compared buying decisions of Arab and German participants in an experimental trust game. Photo-realistic avatars were used instead of photos to control facial features and expressions. The results revealed significant main effects for both reputation scores and avatar faces. Moreover, both variables significantly affected the purchase behavior of Arab as well as German buyers, suggesting cross-cultural universals in the processing of trust cues. The results have implications for future cross-cultural studies in e-commerce as well as the design of online markets and shared virtual environments.

  12. Beyond the Player: A User-Centered Approach to Analyzing Digital Games and Players Using Actor-Network Theory

    ERIC Educational Resources Information Center

    Hung, Aaron Chia Yuan

    2016-01-01

    The paper uses actor-network theory (ANT) to analyze the sociotechnical networks of three groups of adolescents who played online games in different physical and social contexts. These include: an internet café, which allowed the players to be co-present; a personal laptop, which gave the player more control over how he played; and at home through…

  13. Helping others in online games: prosocial behavior in cyberspace.

    PubMed

    Wang, Chih-Chien; Wang, Chia-Hsin

    2008-06-01

    This study examined the reasons players help others in the virtual space of online games. Results of an online empirical survey indicated that both altruism and reciprocity influence prosocial behavior simultaneously. Additionally, the study found that male players are more likely than female players to seek friendship of opposite sex.

  14. Momentum Flux Determination Using the Multi-beam Poker Flat Incoherent Scatter Radar

    NASA Technical Reports Server (NTRS)

    Nicolls, M. J.; Fritts, D. C.; Janches, Diego; Heinselman, C. J.

    2012-01-01

    In this paper, we develop an estimator for the vertical flux of horizontal momentum with arbitrary beam pointing, applicable to the case of arbitrary but fixed beam pointing with systems such as the Poker Flat Incoherent Scatter Radar (PFISR). This method uses information from all available beams to resolve the variances of the wind field in addition to the vertical flux of both meridional and zonal momentum, targeted for high-frequency wave motions. The estimator utilises the full covariance of the distributed measurements, which provides a significant reduction in errors over the direct extension of previously developed techniques and allows for the calculation of an error covariance matrix of the estimated quantities. We find that for the PFISR experiment, we can construct an unbiased and robust estimator of the momentum flux if sufficient and proper beam orientations are chosen, which can in the future be optimized for the expected frequency distribution of momentum-containing scales. However, there is a potential trade-off between biases and standard errors introduced with the new approach, which must be taken into account when assessing the momentum fluxes. We apply the estimator to PFISR measurements on 23 April 2008 and 21 December 2007, from 60-85 km altitude, and show expected results as compared to mean winds and in relation to the measured vertical velocity variances.

  15. Effects of alcohol, initial gambling outcomes, impulsivity, and gambling cognitions on gambling behavior using a video poker task.

    PubMed

    Corbin, William R; Cronce, Jessica M

    2017-06-01

    Drinking and gambling frequently co-occur, and concurrent gambling and drinking may lead to greater negative consequences than either behavior alone. Building on prior research on the effects of alcohol, initial gambling outcomes, impulsivity, and gambling cognitions on gambling behaviors using a chance-based (nonstrategic) slot-machine task, the current study explored the impact of these factors on a skill-based (strategic) video poker task. We anticipated larger average bets and greater gambling persistence under alcohol relative to placebo, and expected alcohol effects to be moderated by initial gambling outcomes, impulsivity, and gambling cognitions. Participants (N = 162; 25.9% female) were randomly assigned to alcohol (target BrAC = .08g%) or placebo and were given $10 to wager on a simulated video poker task, which was programmed to produce 1 of 3 initial outcomes (win, breakeven, or lose) before beginning a progressive loss schedule. Despite evidence for validity of the video poker task and alcohol administration paradigm, primary hypotheses were not supported. Individuals who received alcohol placed smaller wagers than participants in the placebo condition, though this effect was not statistically significant, and the direction of effects was reversed in at-risk gamblers (n = 41). These findings contradict prior research and suggest that alcohol effects on gambling behavior may differ by gambling type (nonstrategic vs. strategic games). Interventions that suggest alcohol is universally disinhibiting may be at odds with young adults' lived experience and thus be less effective than those that recognize the greater complexity of alcohol effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Effects of alcohol, initial gambling outcomes, impulsivity and gambling cognitions on gambling behavior using a video poker task

    PubMed Central

    Corbin, William R.; Cronce, Jessica M.

    2017-01-01

    Drinking and gambling frequently co-occur, and concurrent gambling and drinking may lead to greater negative consequences than either behavior alone. Building on prior research on the effects of alcohol, initial gambling outcomes, impulsivity, and gambling cognitions on gambling behaviors using a chance-based (non-strategic) slot-machine task, the current study explored the impact of these factors on a skill-based (strategic) video poker task. We anticipated larger average bets and greater gambling persistence under alcohol relative to placebo, and expected alcohol effects to be moderated by initial gambling outcomes, impulsivity, and gambling cognitions. Participants (N=162; 25.9% female) were randomly assigned to alcohol (target BrAC = .08 g%) or placebo and were given $10 to wager on a simulated video poker task, which was programmed to produce 1 of 3 initial outcomes (win, breakeven, or lose) before beginning a progressive loss schedule. Despite evidence for validity of the video poker task and alcohol administration paradigm, primary hypotheses were not supported. Individuals who received alcohol placed smaller wagers than participants in the placebo condition, though this effect was not statistically significant, and the direction of effects was reversed in at-risk gamblers (n=41). These findings contradict prior research and suggest that alcohol effects on gambling behavior may differ by gambling type (non-strategic vs. strategic games). Interventions that suggest alcohol is universally disinhibiting may be at odds with young adults’ lived experience and thus be less effective than those that recognize the greater complexity of alcohol effects. PMID:28493742

  17. Player Characteristics and Games: Findings and Implications for Distance Learning

    ERIC Educational Resources Information Center

    Marvel, Michele D.

    2017-01-01

    Understanding the factors that affect participation in online games will help educational game designers develop games that maximize participation. This study investigated whether introversion or extroversion, player motivation, and gender affected participation in online games. Participants (n = 400) completed a 50-item questionnaire about…

  18. Occurrence rate of ion upflow and downflow observed by the Poker Flat Incoherent Scatter Radar (PFISR)

    NASA Astrophysics Data System (ADS)

    Zou, S.; Lu, J.; Varney, R. H.

    2017-12-01

    This study aims to investigate the occurrence rate of ion upflow and downflow events in the auroral ionosphere, using a full 3-year (2011-2013) dataset collected by the Poker Flat Incoherent Scatter Radar (PFISR) at 65.5° magnetic latitude. Ion upflow and downflow events are defined if there are three consecutive data points larger/smaller than 100/-100 m/s in the ion field-aligned velocity altitude profile. Their occurrence rates have been evaluated as a function of magnetic local time (MLT), season, geomagnetic activity, solar wind and interplanetary magnetic field (IMF). We found that the ion upflows are twice more likely to occur on the nightside than the dayside, and have slightly higher occurrence rate near Fall equinox. In contrast, the ion downflow events are more likely to occur in the afternoon sector but also during Fall equinox. In addition, the occurrence rate of ion upflows on the nightside increases when the aurora electrojet index (AE) and planetary K index (Kp) increase, while the downflows measured on the dayside clearly increase as the AE and Kp increase. In general, the occurrence rate of ion upflows increases with enhanced solar wind and IMF drivers. This correlation is particularly strong between the upflows on the nightside and the solar wind dynamic pressure and IMF Bz. The lack of correlation of upflows on the dayside with these parameters is due to the location of PFISR, which is usually equatorward of the dayside auroral zone and within the nightside auroral zone under disturbed conditions. The occurrence rate of downflow at all MLTs does not show strong dependence on the solar wind and IMF conditions. However, it occurs much more frequently on the dayside when the IMF By is strongly positive, i.e., >10 nT and the IMF Bz is strongly negative, i.e., < -10 nT. We suggest that the increased occurrence rate of downflows on the dayside is associated with dayside storm-enhanced density and the plume.

  19. Attitudes towards protective headgear in UK rugby union players

    PubMed Central

    Rumbold, James L; Olusoga, Peter

    2017-01-01

    Background/aim Concussions in rugby union pose a major threat to player welfare. Research has found protective headgear offers no significant protection against concussions but suggests a large proportion of players perceive headgear to be effective in preventing concussions. This study aimed to explore UK rugby union players’ attitudes towards wearing protective headgear. Methods 545 rugby union players (85% male) from a range of playing standards completed an online survey. Quantitative and qualitative data were collected on player attitudes towards protective headgear use. Descriptive statistics, multiple regressions and content analysis were used to analyse the responses. Results 37% of players believed that headgear was effective in preventing head injuries. Playing group was found to be inversely associated with headgear effectiveness (∆R2=0.01, B=−0.13, p=0.02), with youth players holding stronger beliefs that headgear is effective at preventing head injuries compared with all senior groups. The main reasons cited for wearing headgear related to protection from minor injuries (55%) with only 10% of responses related to concussion prevention. Conclusions There appears to be a good awareness in UK players that protective headgear is not effective at preventing concussions. Continued education is vital to ensure players are fully aware of the limitations of headgear, and players who wear it do not engage in overly reckless behaviours as a result. PMID:29081983

  20. Executive Functions Predict the Success of Top-Soccer Players

    PubMed Central

    Vestberg, Torbjörn; Gustafson, Roland; Maurex, Liselotte; Ingvar, Martin; Petrovic, Predrag

    2012-01-01

    While the importance of physical abilities and motor coordination is non-contested in sport, more focus has recently been turned toward cognitive processes important for different sports. However, this line of studies has often investigated sport-specific cognitive traits, while few studies have focused on general cognitive traits. We explored if measures of general executive functions can predict the success of a soccer player. The present study used standardized neuropsychological assessment tools assessing players' general executive functions including on-line multi-processing such as creativity, response inhibition, and cognitive flexibility. In a first cross-sectional part of the study we compared the results between High Division players (HD), Lower Division players (LD) and a standardized norm group. The result shows that both HD and LD players had significantly better measures of executive functions in comparison to the norm group for both men and women. Moreover, the HD players outperformed the LD players in these tests. In the second prospective part of the study, a partial correlation test showed a significant correlation between the result from the executive test and the numbers of goals and assists the players had scored two seasons later. The results from this study strongly suggest that results in cognitive function tests predict the success of ball sport players. PMID:22496850

  1. Calculating ellipse area by the Monte Carlo method and analysing dice poker with Excel at high school

    NASA Astrophysics Data System (ADS)

    Benacka, Jan

    2016-08-01

    This paper reports on lessons in which 18-19 years old high school students modelled random processes with Excel. In the first lesson, 26 students formulated a hypothesis on the area of ellipse by using the analogy between the areas of circle, square and rectangle. They verified the hypothesis by the Monte Carlo method with a spreadsheet model developed in the lesson. In the second lesson, 27 students analysed the dice poker game. First, they calculated the probability of the hands by combinatorial formulae. Then, they verified the result with a spreadsheet model developed in the lesson. The students were given a questionnaire to find out if they found the lesson interesting and contributing to their mathematical and technological knowledge.

  2. Video Player Keyboard Shortcuts

    MedlinePlus

    ... of this page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features ... of accessible keyboard shortcuts for our latest Health videos on the MedlinePlus site. These shortcuts allow you ...

  3. The female player does not exist: gender identity relates to differences in player motivations and play styles.

    PubMed

    Poels, Karolien; De Cock, Nele; Malliet, Steven

    2012-11-01

    This study addresses the female player of massively multiplayer online (role-playing) games and investigates how gender identity (GI), indicating a person's identification with characteristics that are traditionally defined as masculine or feminine, can be used to explain playing patterns within the female gender group. Results from an online survey (n=466) show that females' player motivations and play styles vary as a function of their GI, indicating that it is a relevant and additional predictor of play behavior and confirming that female play behavior cannot be generalized based on stereotypical male/female conceptions.

  4. Visualization of Expert Chat Development in a World of Warcraft Player Group

    ERIC Educational Resources Information Center

    Chen, Mark

    2009-01-01

    This article describes expertise development in a player group in the massively multiplayer online game World of Warcraft using visualization of chat log data. Charts were created to get a general sense of chat trends in a specific player group engaged in "high-end raiding", a 40-person collaborative activity. These charts helped identify patterns…

  5. Human-Technology Relationality and Self-Network Organization: Players and Avatars in World of Warcraft

    ERIC Educational Resources Information Center

    Banks, Jaime

    2013-01-01

    Massively multiplayer online roleplaying games, or MMOs, present an increasingly popular digital media experience whereby identity emerges as players contribute materially to play but contributions are governed by affordances and constraints of the game. Unique to this medium is the player's ability to create and control a digital body--an…

  6. Cue-Reactive Altered State of Consciousness Mediates the Relationship Between Problem-Gambling Severity and Cue-Reactive Urge in Poker-Machine Gamblers.

    PubMed

    Tricker, Christopher; Rock, Adam J; Clark, Gavin I

    2016-06-01

    In order to enhance our understanding of the nature of poker-machine problem-gambling, a community sample of 37 poker-machine gamblers (M age = 32 years, M PGSI = 5; PGSI = Problem Gambling Severity Index) were assessed for urge to gamble (responses on a visual analogue scale) and altered state of consciousness (assessed by the Altered State of Awareness dimension of the Phenomenology of Consciousness Inventory) at baseline, after a neutral cue, and after a gambling cue. It was found that (a) problem-gambling severity (PGSI score) predicted increase in urge (from neutral cue to gambling cue, controlling for baseline; sr (2) = .19, p = .006) and increase in altered state of consciousness (from neutral cue to gambling cue, controlling for baseline; sr (2) = .57, p < .001), and (b) increase in altered state of consciousness (from neutral cue to gambling cue) mediated the relationship between problem-gambling severity and increase in urge (from neutral cue to gambling cue; κ(2) = .40, 99 % CI [.08, .71]). These findings suggest that cue-reactive altered state of consciousness is an important component of cue-reactive urge in poker-machine problem-gamblers.

  7. Games for Social Change: Review of the Potential for Multi Player Online Gaming to Facilitate the Emergence and Growth of Progressive Movements for Social Change within Youth and Community Work

    ERIC Educational Resources Information Center

    Keating, Paul

    2016-01-01

    Building on the use of the internet and social media as sites for activism, this paper highlights the emergence of political activism and collective protest in the online gaming environment. Referencing social movement theory and the rapidly evolving capacity of multiplayer online games to facilitate the development of strong group identities and…

  8. An analysis of switching and non-switching slot machine player behaviour.

    PubMed

    Coates, Ewan; Blaszczynski, Alex

    2013-12-01

    Learning theory predicts that, given the repeated choice to bet between two concurrently available slot machines, gamblers will learn to bet more money on the machine with higher expected return (payback percentage) or higher win probability per spin (volatility). The purpose of this study was to investigate whether this occurs when the two machines vary orthogonally on payback percentage and volatility. The sample comprised 52 first year psychology students (mean age = 20.3 years, 20 females, 32 males) who had played a gaming machine at least once in the previous 12 months. Participants were administered a battery of questionnaires designed to assess level of knowledge on the characteristics and operation of poker machines, frequency of poker machine play in the past 12 months, personality traits of impulsivity and capacity for cognitive reflection, and gambling beliefs. For the experimental task, participants were instructed to play on two PC-simulated electronic gaming machines (EGMs or slot machines) that differed on payback percentage and volatility, with the option of freely switching between EGMs after a practice phase. Results indicated that participants were able to easily discriminate between machines and manifested a preference to play machines offering higher payback or volatility. These findings diverged from previous findings of no preference for play on higher payback/volatility machines, potentially due to of the current study's absence of the option to make multi-line and multi-credit bets. It was concluded that return rate parameters like payback percentage and volatility strongly influenced slot machine preference in the absence of betting options like multi-line bets, though more research is needed to determine the effects of such betting options on player distribution of money between multiple EGMs.

  9. A computer model for high-latitude phase scintillation based on wideband satellite data from Poker Flat

    NASA Astrophysics Data System (ADS)

    Fremouw, E. J.; Lansinger, J. M.

    1981-02-01

    A mathematical model has been developed for describing plasma-density irregularities responsible for radiowave scintillation produced in the auroral ionosphere, and the model has been committed to an applications-oriented computer code, WBMOD. The model characterizes the three-dimensional configuration, gradient sharpness, and height-integrated strength of irregularities represented by a power-law spatial spectrum as functions of geomagnetic latitude, time of day, sunspot number, and planetary geomagnetic activity index. Program WBMOD permits calculation of the power-law index and spectral strength (at a fluctuation frequency of 1 Hz) of phase scintillation, together with scintillation indices (variances) for phase and intensity, using a phase-screen scattering theory. The model has been calibrated and iteratively tested against phase-scintillation data from the DNA Wideband Satellite Experiment, collected at Poker Flat, Alaska. It does not account for seasonal variations in high-latitude scintillation observed in other longitude sectors. The program contains a model for middle-latitude and equatorial irregularities as well as for auroral latitudes, but only the latter has been tested extensively against high-quality scintillation data.

  10. Poker flat radar observations of the magnetosphere-ionosphere coupling electrodynamics of the earthward penetrating plasma sheet following convection enhancements

    NASA Astrophysics Data System (ADS)

    Lyons, L. R.; Zou, S.; Heinselman, C. J.; Nicolls, M. J.; Anderson, P. C.

    2009-05-01

    The plasma sheet moves earthward (equatorward in the ionosphere) after enhancements in convection, and the electrodynamics of this response is strongly influenced by Region 2 magnetosphere-ionosphere coupling. We have used Poker Flat Advanced Modular Incoherent Scatter Radar (PFISR) observations associated with two relatively abrupt southward turnings of the IMF to provide an initial evaluation of aspects of this response. The observations show that strong westward sub-auroral polarization streams (SAPS) flow regions moved equatorward as the plasma sheet electron precipitation (the diffuse aurora) penetrated equatorward following the IMF southward turnings. Consistent with our identification of these flows as SAPS, concurrent DMSP particle precipitation measurements show the equatorial boundary of ion precipitation equatorward of the electron precipitation boundary and that westward flows lie within the low-conductivity region between the two boundaries where the plasma sheet ion pressure gradient is expected to drive downward R2 currents. Evidence for these downward currents is seen in the DMSP magnetometer observations. Preliminary examination indicates that the SAPS response seen in the examples presented here may be common. However, detailed analysis will be required for many more events to reliably determine if this is the case. If so, it would imply that SAPS are frequently an important aspect of the inner magnetospheric electric field distribution, and that they are critical for understanding the response of the magnetosphere-ionosphere system to enhancements in convection, including understanding the earthward penetration of the plasma sheet. This earthward penetration is critical to geomagnetic disturbance phenomena such as the substorm growth phase and the formation of the stormtime ring current. Additionally, for one example, a prompt electric field response to the IMF southward turnings is seen within the inner plasma sheet.

  11. Notions of Video Game Addiction and Their Relation to Self-Reported Addiction among Players of World of Warcraft

    ERIC Educational Resources Information Center

    Oggins, Jean; Sammis, Jeffrey

    2012-01-01

    In this study, 438 players of the online video game, World of Warcraft, completed a survey about video game addiction and answered an open-ended question about behaviors they considered characteristic of video game addiction. Responses were coded and correlated with players' self-reports of being addicted to games and scores on a modified video…

  12. Sustained Authorship: Digital Writing, Self-Publishing, and the Ebook

    ERIC Educational Resources Information Center

    Laquintano, Tim

    2010-01-01

    This article reports on a digital ethnography that examines writing, authorship, and self-publication in an online niche market. Drawing on interview and web data collected over 3 years, it focuses on the writing practices that have supported the production, distribution, and sanction of 13 ebooks self-published by online poker players. The…

  13. Social Interactions in Online Gaming

    ERIC Educational Resources Information Center

    Griffiths, Mark; Hussain, Zaheer; Grüsser, Sabine M.; Thalemann, Ralf; Cole, Helena; Davies, Mark N. O.; Chappell, Darren

    2011-01-01

    This paper briefly overviews five studies examining massively multiplayer online role-playing games (MMORPGs). The first study surveyed 540 gamers and showed that the social aspects of the game were the most important factor for many gamers. The second study explored the social interactions of 912 MMORPG players and showed they created strong…

  14. A Qualitative Analysis of Online Gaming Addicts in Treatment

    ERIC Educational Resources Information Center

    Beranuy, Marta; Carbonell, Xavier; Griffiths, Mark D.

    2013-01-01

    Online gaming addiction is a relatively under-researched area and there have been few studies examining online gamers in treatment. This paper reports the findings from a qualitative interview study of nine players undergoing treatment for their addictive playing of Massively Multiplayer Online Role Playing Games (MMORPGs). A face-to-face…

  15. The Semiotic Ecology and Linguistic Complexity of an Online Game World

    ERIC Educational Resources Information Center

    Thorne, Steven L.; Fischer, Ingrid; Lu, Xiaofei

    2012-01-01

    Multiplayer online games form complex semiotic ecologies that include game-generated texts, player-to-player communication and collaboration, and associated websites that support in-game play. This article describes an exploratory study of the massively multiplayer online game (MMO) "World of Warcraft" ("WoW"), with specific…

  16. Motivations for play in online games.

    PubMed

    Yee, Nick

    2006-12-01

    An empirical model of player motivations in online games provides the foundation to understand and assess how players differ from one another and how motivations of play relate to age, gender, usage patterns, and in-game behaviors. In the current study, a factor analytic approach was used to create an empirical model of player motivations. The analysis revealed 10 motivation subcomponents that grouped into three overarching components (achievement, social, and immersion). Relationships between motivations and demographic variables (age, gender, and usage patterns) are also presented.

  17. Who Pays to Play Freemium Games? The Profiles and Motivations of Players Who Make Purchases Within Social Casino Games

    PubMed Central

    Gainsbury, Sally M.; King, Daniel L.; Russell, Alex M. T.; Delfabbro, Paul

    2016-01-01

    Background and aims Social casino games (SCGs) feature gambling themes and are typically free to download and play with optional in-game purchases. Although few players spend money, this is sufficient to make them profitable for game developers. Little is known about the profile and motivations of paying players as compared to non-paying players. Methods This study compared the characteristics of 521 paying and non-paying Australian social casino game players who completed an online survey. Results Paying players were more likely to be younger, male, speak a non-English language, and have a university education than non-payers. Paying players were more likely to be more highly involved in SCG in terms of play frequency and engagement with games and emphasized social interaction more strongly as a motivation for playing. A cluster analysis revealed distinct subgroups of paying players; these included more frequent moderate spenders who made purchases to avoid waiting for credits and to give gifts to friends as well as less frequent high spenders who made purchases to increase the entertainment value of the game. Discussion These findings suggest that paying players have some fundamental differences from non-paying players and high spenders are trying to maximize their enjoyment, while non-spenders are content with the game content they access. Conclusions Given the structural similarities between SCG and online gambling, understanding subgroups of players may have broader implications, including identifying characteristics of gamers who may also engage in gambling and players who may develop problems related to excessive online gaming. PMID:27306146

  18. Who Pays to Play Freemium Games? The Profiles and Motivations of Players Who Make Purchases Within Social Casino Games.

    PubMed

    Gainsbury, Sally M; King, Daniel L; Russell, Alex M T; Delfabbro, Paul

    2016-06-01

    Background and aims Social casino games (SCGs) feature gambling themes and are typically free to download and play with optional in-game purchases. Although few players spend money, this is sufficient to make them profitable for game developers. Little is known about the profile and motivations of paying players as compared to non-paying players. Methods This study compared the characteristics of 521 paying and non-paying Australian social casino game players who completed an online survey. Results Paying players were more likely to be younger, male, speak a non-English language, and have a university education than non-payers. Paying players were more likely to be more highly involved in SCG in terms of play frequency and engagement with games and emphasized social interaction more strongly as a motivation for playing. A cluster analysis revealed distinct subgroups of paying players; these included more frequent moderate spenders who made purchases to avoid waiting for credits and to give gifts to friends as well as less frequent high spenders who made purchases to increase the entertainment value of the game. Discussion These findings suggest that paying players have some fundamental differences from non-paying players and high spenders are trying to maximize their enjoyment, while non-spenders are content with the game content they access. Conclusions Given the structural similarities between SCG and online gambling, understanding subgroups of players may have broader implications, including identifying characteristics of gamers who may also engage in gambling and players who may develop problems related to excessive online gaming.

  19. A study of gravity-wave spectra in the troposphere and stratosphere at 5-min to 5-day periods with the Poker Flat MST radar

    NASA Technical Reports Server (NTRS)

    Bemra, R. S.; Rastogi, P. K.; Balsley, B. B.

    1986-01-01

    An analysis of frequency spectra at periods of about 5 days to 5 min from two 20-day sets of velocity measurements in the stratosphere and troposphere region obtained with the Poker Flat mesosphere-stratosphere-troposphere (MST) radar during January and June, 1984 is presented. A technique based on median filtering and averaged order statistics for automatic editing, smoothing and spectral analysis of velocity time series contaminated with spurious data points or outliers is outlined. The validity of this technique and its effects on the inferred spectral index was tested through simulation. Spectra obtained with this technique are discussed. The measured spectral indices show variability with season and height, especially across the tropopause. The discussion briefly outlines the need for obtaining better climatologies of velocity spectra and for the refinements of the existing theories to explain their behavior.

  20. Active Player Modeling in the Iterated Prisoner's Dilemma

    PubMed Central

    Park, Hyunsoo; Kim, Kyung-Joong

    2016-01-01

    The iterated prisoner's dilemma (IPD) is well known within the domain of game theory. Although it is relatively simple, it can also elucidate important problems related to cooperation and trust. Generally, players can predict their opponents' actions when they are able to build a precise model of their behavior based on their game playing experience. However, it is difficult to make such predictions based on a limited number of games. The creation of a precise model requires the use of not only an appropriate learning algorithm and framework but also a good dataset. Active learning approaches have recently been introduced to machine learning communities. The approach can usually produce informative datasets with relatively little effort. Therefore, we have proposed an active modeling technique to predict the behavior of IPD players. The proposed method can model the opponent player's behavior while taking advantage of interactive game environments. This experiment used twelve representative types of players as opponents, and an observer used an active modeling algorithm to model these opponents. This observer actively collected data and modeled the opponent's behavior online. Most of our data showed that the observer was able to build, through direct actions, a more accurate model of an opponent's behavior than when the data were collected through random actions. PMID:26989405

  1. Active Player Modeling in the Iterated Prisoner's Dilemma.

    PubMed

    Park, Hyunsoo; Kim, Kyung-Joong

    2016-01-01

    The iterated prisoner's dilemma (IPD) is well known within the domain of game theory. Although it is relatively simple, it can also elucidate important problems related to cooperation and trust. Generally, players can predict their opponents' actions when they are able to build a precise model of their behavior based on their game playing experience. However, it is difficult to make such predictions based on a limited number of games. The creation of a precise model requires the use of not only an appropriate learning algorithm and framework but also a good dataset. Active learning approaches have recently been introduced to machine learning communities. The approach can usually produce informative datasets with relatively little effort. Therefore, we have proposed an active modeling technique to predict the behavior of IPD players. The proposed method can model the opponent player's behavior while taking advantage of interactive game environments. This experiment used twelve representative types of players as opponents, and an observer used an active modeling algorithm to model these opponents. This observer actively collected data and modeled the opponent's behavior online. Most of our data showed that the observer was able to build, through direct actions, a more accurate model of an opponent's behavior than when the data were collected through random actions.

  2. Frontal lobe function in chess players.

    PubMed

    Nejati, Majid; Nejati, Vahid

    2012-01-01

    Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST) data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players don't have any preference in any stage of Stroop test. Chess players don't have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  3. Physical fitness of elite Belgian soccer players by player position.

    PubMed

    Boone, Jan; Vaeyens, Roel; Steyaert, Adelheid; Vanden Bossche, Luc; Bourgois, Jan

    2012-08-01

    The purpose of this study was to gain an insight into the physical and physiological profile of elite Belgian soccer players with specific regard to the player's position on the field. The sample consisted of 289 adult players from 6 different first division teams. The players were divided into 5 subgroups (goalkeepers, center backs, full backs, midfielders, and strikers) according to their self-reported best position on the field. The subjects performed anaerobic (10-m sprint, 5 × 10-m shuttle run [SR], squat jump [SJ], and countermovement jump [CMJ]) and aerobic (incremental running protocol) laboratory tests. The strikers had significantly shorter sprinting times (5-, 5- to 10-m time, and SR) compared with the midfielders, center backs, and goalkeepers, whereas the full backs were also significantly faster compared with the goalkeepers and the center backs. The goalkeepers and the center backs displayed higher jumping heights (total mean SJ = 40.7 ± 4.6 cm and CMJ = 43.1 ± 4.9 cm) compared with the other 3 positions, whereas the strikers also jumped higher than the full backs and the midfielders did. Regarding the aerobic performance, both full backs and the midfielders (61.2 ± 2.7 and 60.4 ± 2.8 ml · min(-1) · kg(-1), respectively) had a higher VO2max compared with the strikers, center backs, and goalkeepers (56.8 ± 3.1, 55.6 ± 3.5, and 52.1 ± 5.0 ml · min(-1) · kg(-1), respectively). From this study, it could be concluded that players in different positions have different physiological characteristics. The results of this study might provide useful insights for individualized conditional training programs for soccer players. Aside from the predominant technical and tactical skills, a physical profile that is well adjusted to the position on the field might enhance game performance.

  4. Demographic factors and playing variables in online computer gaming.

    PubMed

    Griffiths, Mark D; Davies, Mark N O; Chappell, Darren

    2004-08-01

    Despite the growing popularity of online game playing, there has been no primary survey of its players. Therefore, an online questionnaire survey was used to examine basic demographic factors of online computer game players who played the popular online game Everquest (i.e., gender, age, marital status, nationality, education level, occupation). The survey also examined playing frequency (i.e., amount of time spent playing the game a week), playing history (i.e., how long they had been playing the game, who they played the game with, whether they had ever gender swapped their game character), the favorite and least favorite aspects of playing the game, and what they sacrifice (if anything) to play the game. Results showed that 81% of online game players were male, and that the mean age of players was 27.9 years of age. For many players, the social aspects of the game were the most important factor in playing. A small minority of players appear to play excessively (over 80 h a week), and results suggest that a small minority sacrifice important activities in order to play (e.g., sleep, time with family and/or partner, work, or schooling).

  5. Colonic transit in soccer players.

    PubMed

    Sesboüé, B; Arhan, P; Devroede, G; Lecointe-Besançon, I; Congard, P; Bouchoucha, M; Fabre, J

    1995-04-01

    To evaluate the effects of exercise on colonic function, we measured total and segmental transit times in 11 male soccer players and nine male radiology student technicians. Diet was kept constant in all subjects, who maintained their normal activities. For the soccer players, normal activities included 15 h of training and one match each week. Transit times were measured with radioopaque markers, using the multiple-ingestion, single-radiograph technique. No overall difference in large bowel transit was observed between the two groups. Right colon transit was considerably slower in the soccer players, whereas left colon and rectal transit were slightly accelerated. We conclude that an intensive sport activity only modifies regional differences in large bowel function. This may be of importance in extreme conditions, such as those experienced by marathon runners. Data should be obtained before prescribing exercise to treat constipation.

  6. Player Types, Play Styles, and Play Complexity: Updating the Entertainment Grid

    ERIC Educational Resources Information Center

    Rademacher Mena, Ricardo Javier

    2012-01-01

    In a previous work the author created the Education and Entertainment Grid by combining various taxonomies from the fields of play and learning. In this paper, a section of this grid known as the Entertainment Grid will be extended by including previously unused elements of Richard Bartle's online player types and Robert Caillois' play complexity.…

  7. Learner's Attitudes towards Online Language Learning; and Corresponding Success Rates

    ERIC Educational Resources Information Center

    Cinkara, Emrah; Bagceci, Birsen

    2013-01-01

    Online teaching has long been a key area of interest recently in every field of education as well as English language teaching. Numerous hardware tools, such as, mp3 players, mobile devices, and so on; and software applications, such as, podcasts, wikis, learning management systems, and so on, have been used in distance and online instruction and…

  8. Who Are the Players in Canadian Curriculum?

    ERIC Educational Resources Information Center

    Milburn, Geoffrey

    1987-01-01

    Labels range of persons advocating different theoretical positions of Canadian curriculum as "players." Describes players as "managers,""predictors,""transformers,""sleuths,""analysts." Values varied viewpoints for attention to language regarding curriculum, critical review of…

  9. Daily Fantasy Sports Players: Gambling, Addiction, and Mental Health Problems.

    PubMed

    Nower, Lia; Caler, Kyle R; Pickering, Dylan; Blaszczynski, Alex

    2018-01-19

    Studies point to a relationship between fantasy sports/daily fantasy sports (DFS) play and gambling behavior. However, little is known about the nature of those relationships, particularly regarding the development of gambling problems. This study investigates the nature, frequency, and preferences of gambling behavior as well as problem gambling severity and comorbid conditions among DFS players. Data were collected from an epidemiologic survey of 3634 New Jersey residents on gambling and leisure activities. Participants were contacted by phone (land-line and cell) and online to obtain a representative, cross-sectional sample of non-institutionalized adults, aged 18 years or older. Excluding non-gamblers, the remaining 2146 participants, included in these analyses, indicated they had either played DFS (n = 299) or had gambled but not played DFS (1847) in the past year. Univariate comparisons and multiple logistic regression analyses were performed to identify the most significant characteristics and predictors of DFS players. Overall, a higher number of gambling activities, high frequency gambling, male gender, and reports of suicidal thoughts in the past year were most predictive of DFS players. Being Hispanic (vs. Caucasian) and/or single (vs. married or living with a partner) also doubled the odds of DFS play. Findings suggest that DFS players are characterized by high gambling frequency and problem severity and comorbid problems, notably suicidal ideation. Future research should examine the motivations and possible etiological sub-types of DFS players and the nature and course of DFS play, particularly in relation to gambling behavior and the development of gambling and other problems.

  10. Prevalence of Ulnar Collateral Ligament Surgery in Professional Baseball Players.

    PubMed

    Conte, Stan A; Fleisig, Glenn S; Dines, Joshua S; Wilk, Kevin E; Aune, Kyle T; Patterson-Flynn, Nancy; ElAttrache, Neal

    2015-07-01

    While the high rate of ulnar collateral ligament (UCL) injuries in professional baseball is widely discussed in the media and medical literature, the actual prevalence of UCL reconstruction has not been documented. The prevalence of UCL reconstruction will be higher among pitchers than nonpitchers, and Major League Baseball (MLB) pitchers will have a higher prevalence than will minor league pitchers. Descriptive epidemiology study. An online questionnaire was distributed to all 30 MLB organizations. Certified athletic trainers from each team administered the questionnaire to all players in the organization, including major league players and 6 levels of minor league players. Demographic data were compared between major and minor league players. Continuous variables (age, years of professional baseball, country of origin, etc) were compared with Student t tests (P < .05). Categorical variables (level, position, etc) were compared using chi-square analysis (P < .05). A total of 5088 professional baseball players (722 major league and 4366 minor league) participated in the survey. Pitchers represented 53% of all players, and 497 players reported at least 1 UCL reconstruction, demonstrating a prevalence rate of 10% (497 of 5088). Pitchers reported a significantly higher prevalence of UCL reconstruction (16%; 437 of 2706) than nonpitchers (3%; 60 of 2382; P < .001). Among major league pitchers, 25% (96 of 382) had a history of UCL reconstruction, while minor league pitchers showed a 15% (341 of 2324) prevalence (P < .001). Major league pitchers were also significantly older (28.8 ± 3.9 years) than minor league pitchers (22.8 ± 3.0; P < .001). The majority of major leaguers (86%) had their UCL reconstruction as professional pitchers, whereas the majority of minor league pitchers (61%) underwent their UCL reconstruction during high school and college (P < .001). The rates of UCL revision, prior elbow surgery, prior shoulder surgery, and types of UCL graft were similar

  11. Randomness in nonlocal games between mistrustful players.

    PubMed

    Miller, Carl A; Shi, Yaoyun

    2017-06-01

    If two quantum players at a nonlocal game G achieve a superclassical score, then their measurement outcomes must be at least partially random from the perspective of any third player. This is the basis for device-independent quantum cryptography. In this paper we address a related question: does a superclassical score at G guarantee that one player has created randomness from the perspective of the other player? We show that for complete-support games, the answer is yes: even if the second player is given the first player's input at the conclusion of the game, he cannot perfectly recover her output. Thus some amount of local randomness (i.e., randomness possessed by only one player) is always obtained when randomness is certified from nonlocal games with quantum strategies. This is in contrast to non-signaling game strategies, which may produce global randomness without any local randomness. We discuss potential implications for cryptographic protocols between mistrustful parties.

  12. Spondylolysis in young tennis players

    PubMed Central

    Ruiz‐Cotorro, A; Balius‐Matas, R; Estruch‐Massana, A; Angulo, J Vilaró

    2006-01-01

    The general aetiology, diagnosis, and treatment of spondylolysis, a bone defect in the pars interarticularis of the vertebra, are reviewed. A retrospective study of young tennis players diagnosed between 2000 and 2004 with spondylolysis with or without spondylolisthesis, assessed by radiography and planar bone scintigraphy, is described. If the radiographic results were negative, computed tomography was performed. Sixty six cases were evaluated: 53 L5 lesions, eight L4 lesions, two L3 lesions, and one bilateral lesion at the L2 level. Two more lesions at two levels were found (bilateral L5 and unilateral L4 and L3 on the right side). Classification, treatment, and outcome of the cases are reported. A combination of radiography, planar bone scintigraphy, and SPECT is useful for evaluating spondylolysis in tennis players and recommending treatment. Use of a brace did not appear to achieve significant results. PMID:16632576

  13. Teaching intelligent design or sparking interest in science? What players do with Will Wright's Spore

    NASA Astrophysics Data System (ADS)

    Owens, Trevor

    2012-12-01

    The 2008 commercial video game Spore allowed more than a million players to design their own life forms. Starting from single-celled organisms players played through a caricature of natural history. Press coverage of the game's release offer two frames for thinking about the implications of the game. Some scientists and educators saw the game as a troubling teacher of intelligent design, while others suggested it might excite public interest in science. This paper explores the extent to which these two ways of thinking about the game are consistent with what players have done with the game in its online community. This analysis suggests that, at least for the players participating in this community, the game has not seduced them into believing in intelligent design. Instead the activities of these players suggest that the game has played a catalytic role in engaging the public with science. These findings indicate that designers of educational games may wish to consider more deeply tensions between prioritizing accuracy of content in educational games over player engagement.

  14. Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

    PubMed

    Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

    2014-07-07

    The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

  15. [Dietary behaviours of volleyball and basketball players].

    PubMed

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

    In sports, such as basketball and volleyball, players must demonstrate the speed, strength, stamina and concentration. Correct nutrition affects the strength of the muscles and the extension of capacity. It is also necessary for the proper functioning of the nervous system and determines the rate of regeneration after physical effort. The aim of this study was to assess dietary behaviours of professional volleyball and basketball players and compare the prevalence of correct behaviours in both groups. 209 professional volleyball and basketball players from sports clubs localized in six Silesian cities were survived with the mean of author questionnaire. The chi-square test was used to examine differences in the prevalence of the correct behaviours among players. Analysis of the results obtained showed that 52% of the players had 4-5 meals a day. 35% of respondents had wholemeal bread and/or groats daily. Milk and dairy products daily ate 71% of surveyed players, meat and sausages 70% respectively. 41% of respondents had cottage cheese and 28% had fish several times a week. Vegetables and fruit were eaten by 21% and respectively 23% of respondents. Sweets were eaten daily by 40% of surveyed, while fast-food were eaten several times a week by 17% of players. Nutrients for athletes were used by 32%, and vitamin supplementation by 48% of respondents. Prevalence of correct dietary behaviour in the group of professional volleyball and basketball players differed. Basketball players statistically more frequently than volleyball players had 4-5 meals a day, had wholemeal bread and/or thick groats, milk and dairy products, meat and sausages, especially poultry. They had raw vegetables and fruit several times a day. They drank more than 2.5 liters of fluids per day. They also significantly more frequently than volleyball players consumed the fast-food occasionally or never. Dietary behaviours of surveyed players were incorrect. Comparison of prevalence of proper behaviours

  16. Vitamin D Deficiency Among Professional Basketball Players.

    PubMed

    Fishman, Matthew P; Lombardo, Stephen J; Kharrazi, F Daniel

    2016-07-01

    Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes. There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine. Cross-sectional study; Level of evidence, 3. This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (<20 ng/mL), insufficient (20-32 ng/mL), and sufficient (>32 ng/mL). After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D-sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly differ depending on vitamin D status (P = .15 and .77

  17. Zoning Issues and Area of Interest Management in Massively Multiplayer Online Games

    NASA Astrophysics Data System (ADS)

    Ahmed, Dewan Tanvir; Shirmohammadi, Shervin

    Game is a way of entertainment, a means for excitement, fun and socialization. Online games have achieved popularity due to increasing broadband adoption among consumers. Relatively cheap bandwidth Internet connections allow large number of players to play together. Since the introduction of Network Virtual Environment (NVE) in 1980s for military simulation, many interesting applications have been evolved over the past few decades. Massively multiplayer online (role-playing) game, MMOG or MMORPG, is a new genre of online games that has emerged with the introduction of Ultima since 1997. It is a kind of online computer game with the participation of hundreds of thousands of players in a virtual world.

  18. The Prevalence of Injuries in Professional Turkish Soccer Players

    ERIC Educational Resources Information Center

    Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.

    2011-01-01

    Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…

  19. Respiratory function in wind instrument players.

    PubMed

    Zuskin, Eugenija; Mustajbegovic, Jadranka; Schachter, E N; Kern, Josipa; Vitale, Ksenija; Pucarin-Cvetkovic, Jasna; Chiarelli, A; Milosevic, M; Jelinic, Jagoda Doko

    2009-01-01

    The playing of wind instruments has been associated with changes in respiratory function. To investigate the effect of playing wind instruments on lung function and respiratory symptoms. The present study included 99 wind instrument players and a group of 41 string instrument players as a control from 3 major orchestras in Zagreb, Croatia. Data on chronic respiratory symptoms were recorded in all studied subjects. Lung function was measured in wind instrument players by recording maximum expiratory flow-volume curves. Wind instrument players demonstrated significantly higher prevalences of sinusitis, nasal catarrh and hoarseness compared to control musicians. One wind instrument player developed asthma associated with his work. Odds ratios for wind instrument players were significant for chronic cough, chronic phlegm and chronic bronchitis by smoking habit (p<0.05 or p<0.01) but not for length of employment. Ventilatory capacity data indicate that wind instrument players had significantly greater FEV1 (smokers and nonsmokers) as well as FEF50 (nonsmokers) (p<0.05) compared to predicted values. Regression analysis of pulmonary function tests in wind instrument players demonstrate a significant link between FEV1 and FEF50 and length of employment. Those wind instrument players with longer employment had the greatest increases in lung function. Our data suggest that musicians playing wind instruments may be susceptible to chronic upper airway symptoms. Interestingly wind instrument playing may be associated with higher than expected lung function parameters.

  20. Chess players' fame versus their merit.

    PubMed

    Simkin, M V; Roychowdhury, V P

    2015-12-12

    We investigate a pool of international chess title holders born between 1901 and 1943. Using Elo ratings, we compute for every player his expected score in a game with a randomly selected player from the pool. We use this figure as the player's merit. We measure players' fame as the number of Google hits. The correlation between fame and merit is 0.38. At the same time, the correlation between the logarithm of fame and merit is 0.61. This suggests that fame grows exponentially with merit.

  1. Auditory memory function in expert chess players

    PubMed Central

    Fattahi, Fariba; Geshani, Ahmad; Jafari, Zahra; Jalaie, Shohreh; Salman Mahini, Mona

    2015-01-01

    Background: Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. Methods: The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. Results: The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. Conclusion: Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time. PMID:26793666

  2. Auditory memory function in expert chess players.

    PubMed

    Fattahi, Fariba; Geshani, Ahmad; Jafari, Zahra; Jalaie, Shohreh; Salman Mahini, Mona

    2015-01-01

    Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time.

  3. A Comparison of Cognitive Function in Former Rugby Union Players Compared with Former Non-Contact-Sport Players and the Impact of Concussion History.

    PubMed

    Hume, Patria A; Theadom, Alice; Lewis, Gwyn N; Quarrie, Kenneth L; Brown, Scott R; Hill, Rosamund; Marshall, Stephen W

    2017-06-01

    This study investigated differences in cognitive function between former rugby and non-contact-sport players, and assessed the association between concussion history and cognitive function. Overall, 366 former players (mean ± standard deviation [SD] age 43.3 ± 8.2 years) were recruited from October 2012 to April 2014. Engagement in sport, general health, sports injuries and concussion history, and demographic information were obtained from an online self-report questionnaire. Cognitive functioning was assessed using the online CNS Vital Signs neuropsychological test battery. Cohen's d effect size statistics were calculated for comparisons across player groups, concussion groups (one or more self-reported concussions versus no concussions) and between those groups with CNS Vital Signs age-matched norms (US norms). Individual differences within groups were represented as SDs. The elite-rugby group (n = 103) performed worse on tests of complex attention, processing speed, executive functioning, and cognitive flexibility than the non-contact-sport group (n = 65), and worse than the community-rugby group (n = 193) on complex attention. The community-rugby group performed worse than the non-contact group on executive functioning and cognitive flexibility. Compared with US norms, all three former player groups performed worse on verbal memory and reaction time; rugby groups performed worse on processing speed, cognitive flexibility and executive functioning; and the community-rugby group performed worse on composite memory. The community-rugby group and non-contact-sport group performed slightly better than US norms on complex attention, as did the elite-rugby group for motor speed. All three player groups had greater individual differences than US norms on composite memory, verbal memory and reaction time. The elite-rugby group had greater individual differences on processing speed and complex attention, and the community-rugby group had greater individual

  4. Anthropometric Characteristics of Columbia, South Carolina, Youth Baseball Players and Dixie Youth World Series Players

    ERIC Educational Resources Information Center

    French, Karen E.; Spurgeon, John H.; Nevett, Michael E.

    2007-01-01

    The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight…

  5. Deceit and facial expression in children: the enabling role of the “poker face” child and the dependent personality of the detector

    PubMed Central

    Gadea, Marien; Aliño, Marta; Espert, Raúl; Salvador, Alicia

    2015-01-01

    This study presents the relation between the facial expression of a group of children when they told a lie and the accuracy in detecting the lie by a sample of adults. To evaluate the intensity and type of emotional content of the children’s faces, we applied an automated method capable of analyzing the facial information from the video recordings (FaceReader 5.0 software). The program classified videos as showing a neutral facial expression or an emotional one. There was a significant higher mean of hits for the emotional than for the neutral videos, and a significant negative correlation between the intensity of the neutral expression and the number of hits from the detectors. The lies expressed with emotional facial expression were more easily recognized by adults than the lies expressed with a “poker face”; thus, the less expressive the child the harder it was to guess. The accuracy of the lie detectors was then correlated with their subclinical traits of personality disorders, to find that participants scoring higher in the dependent personality were significantly better lie detectors. A non-significant tendency for women to discriminate better was also found, whereas men tended to be more suspicious than women when judging the children’s veracity. This study is the first to automatically decode the facial information of the lying child and relate these results with personality characteristics of the lie detectors in the context of deceptive behavior research. Implications for forensic psychology were suggested: to explore whether the induction of an emotion in a child during an interview could be useful to evaluate the testimony during legal trials. PMID:26284012

  6. Online gaming addiction? Motives predict addictive play behavior in massively multiplayer online role-playing games.

    PubMed

    Kuss, Daria J; Louws, Jorik; Wiers, Reinout W

    2012-09-01

    Recently, there have been growing concerns about excessive online gaming. Playing Massively Multiplayer Online Role-Playing Games (MMORPGs) appears to be particularly problematic, because these games require a high degree of commitment and time investment from the players to the detriment of occupational, social, and other recreational activities and relations. A number of gaming motives have been linked to excessive online gaming in adolescents and young adults. We assessed 175 current MMORPG players and 90 nonplayers using a Web-based questionnaire regarding their gaming behavior, problems as consequences of gaming, and game motivations and tested their statistical associations. Results indicated that (a) MMORPG players are significantly more likely to experience gaming-related problems relative to nonplayers, and that (b) the gaming motivations escapism and mechanics significantly predicted excessive gaming and appeared as stronger predictors than time investment in game. The findings support the necessity of using measures that distinguish between different types of online games. In addition, this study proves useful regarding the current discussion on establishing (online) gaming addiction as a diagnosis in future categorizations of psychopathology.

  7. Effect of Self-Worth and Parenting Style on the Planned Behavior in an Online Moral Game

    ERIC Educational Resources Information Center

    Hong, Jon-Chao; Hwang, Ming-Yueh; Wang, Chun-Kai; Hsu, Tsui-Fang; Chen, Yu-Ju; Chan, Chiung-Hua

    2011-01-01

    This idea of integrating moral education to digital gaming platform had been discussed since digital and online approaches were used in teaching. Online interactive instruction was one of moral teaching forms to assist moral instruction. However, most moral-related interactive online games lacked functions for players to explore themselves while…

  8. Quantum Two Player Game in Thermal Environment

    PubMed Central

    Dajka, Jerzy; Kłoda, Dawid; Łobejko, Marcin; Sładkowski, Jan

    2015-01-01

    A two-player quantum game is considered in the presence of thermal decoherence. It is shown how the thermal environment modeled in terms of rigorous Davies approach affects payoffs of the players. The conditions for either beneficial or pernicious effect of decoherence are identified. The general considerations are exemplified by the quantum version of Prisoner Dilemma. PMID:26322833

  9. N-player stochastic differential games

    NASA Technical Reports Server (NTRS)

    Varaiya, P.

    1976-01-01

    The paper presents conditions which guarantee that the control strategies adopted by N players constitute an efficient solution, an equilibrium, or a core solution. The system dynamics are described by an Ito equation, and all players have perfect information. When the set of instantaneous joint costs and velocity vectors is convex, the conditions are necessary.

  10. Stochastic stability in three-player games.

    PubMed

    Kamiński, Dominik; Miekisz, Jacek; Zaborowski, Marcin

    2005-11-01

    Animal behavior and evolution can often be described by game-theoretic models. Although in many situations the number of players is very large, their strategic interactions are usually decomposed into a sum of two-player games. Only recently were evolutionarily stable strategies defined for multi-player games and their properties analyzed [Broom, M., Cannings, C., Vickers, G.T., 1997. Multi-player matrix games. Bull. Math. Biol. 59, 931-952]. Here we study the long-run behavior of stochastic dynamics of populations of randomly matched individuals playing symmetric three-player games. We analyze the stochastic stability of equilibria in games with multiple evolutionarily stable strategies. We also show that, in some games, a population may not evolve in the long run to an evolutionarily stable equilibrium.

  11. Developing 21st Century Skills through Gameplay: To What Extent Are Young People Who Play the Online Computer Game Minecraft Acquiring and Developing Media Literacy and the Four Cs Skills?

    ERIC Educational Resources Information Center

    Morgan, Mia Lynn

    2015-01-01

    Two questions drove this case study. 1) To what extent does playing the online computer game Minecraft at home in a multiplayer environment impact a player's media literacy skills of analysis, evaluation, and access? 2) To what extent does playing the online computer game Minecraft at home in a multiplayer environment impact a player's 21st…

  12. Risk factors for patellar tendinopathy in basketball and volleyball players: a cross-sectional study.

    PubMed

    van der Worp, H; van Ark, M; Zwerver, J; van den Akker-Scheek, I

    2012-12-01

    Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. The findings are conflicting, though, and most research has been conducted on elite athletes. The aim of the current study is to determine the risk factors for PT in a large representative sample of basketball and volleyball players. Separate risk factors for men and women, basketball and volleyball players, and athletes with unilateral and bilateral PT were identified. All basketball and volleyball players between ages 18 and 35 from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete an online questionnaire on knee complaints and risk factors for PT. The logistic regression analyses included 2224 subjects. The risk factors for PT were age, playing at the national level, being male and playing volleyball (compared with playing basketball). The risk factors for men and women were comparable. Among volleyball players, outside hitters and middle blockers/hitters had an increased risk compared with setters. For basketball players, no risk factors could be identified. No differences in the risk factors were found between athletes with unilateral and bilateral PT. These findings should be taken into account for prevention and rehabilitation purposes. © 2011 John Wiley & Sons A/S.

  13. Executive Functioning in Highly Talented Soccer Players

    PubMed Central

    Verburgh, Lot; Scherder, Erik J. A.; van Lange, Paul A.M.; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer. PMID:24632735

  14. Clinicopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football

    PubMed Central

    Mez, Jesse; Daneshvar, Daniel H.; Kiernan, Patrick T.; Abdolmohammadi, Bobak; Alvarez, Victor E.; Huber, Bertrand R.; Alosco, Michael L.; Solomon, Todd M.; Nowinski, Christopher J.; McHale, Lisa; Cormier, Kerry A.; Kubilus, Caroline A.; Martin, Brett M.; Murphy, Lauren; Baugh, Christine M.; Montenigro, Phillip H.; Chaisson, Christine E.; Tripodis, Yorghos; Kowall, Neil W.; Weuve, Jennifer; McClean, Michael D.; Cantu, Robert C.; Goldstein, Lee E.; Katz, Douglas I.; Stern, Robert A.; Stein, Thor D.; McKee, Ann C.

    2018-01-01

    IMPORTANCE Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE). OBJECTIVE To determine the neuropathological and clinical features of deceased football players with CTE. DESIGN, SETTING, AND PARTICIPANTS Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history. EXPOSURES Participation in American football at any level of play. MAIN OUTCOMES AND MEASURES Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia. RESULTS Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47–76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52–77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre–high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had

  15. Clinicopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football.

    PubMed

    Mez, Jesse; Daneshvar, Daniel H; Kiernan, Patrick T; Abdolmohammadi, Bobak; Alvarez, Victor E; Huber, Bertrand R; Alosco, Michael L; Solomon, Todd M; Nowinski, Christopher J; McHale, Lisa; Cormier, Kerry A; Kubilus, Caroline A; Martin, Brett M; Murphy, Lauren; Baugh, Christine M; Montenigro, Phillip H; Chaisson, Christine E; Tripodis, Yorghos; Kowall, Neil W; Weuve, Jennifer; McClean, Michael D; Cantu, Robert C; Goldstein, Lee E; Katz, Douglas I; Stern, Robert A; Stein, Thor D; McKee, Ann C

    2017-07-25

    Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE). To determine the neuropathological and clinical features of deceased football players with CTE. Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history. Participation in American football at any level of play. Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia. Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47-76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52-77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre-high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe CTE pathology, 75 (89

  16. Why people continue to play online games: in search of critical design factors to increase customer loyalty to online contents.

    PubMed

    Choi, Dongseong; Kim, Jinwoo

    2004-02-01

    As people increasingly play online games, numerous new features have been proposed to increase players' log-on time at online gaming sites. However, few studies have investigated why people continue to play certain online games or which design features are most closely related to the amount of time spent by players at particular online gaming sites. This study proposes a theoretical model using the concepts of customer loyalty, flow, personal interaction, and social interaction to explain why people continue to play online network games. The study then conducts a large-scale survey to validate the model. Finally, it analyzes current online games to identify design features that are closely related to the theoretical concepts. The results indicate that people continue to play online games if they have optimal experiences while playing the games. This optimal experience can be attained if the player has effective personal interaction with the system or pleasant social interactions with other people connected to the Internet. Personal interaction can be facilitated by providing appropriate goals, operators and feedback; social interaction can be facilitated through appropriate communication places and tools. This paper ends with the implications of applying the study results to other domains such as e-commerce and cyber communities.

  17. Incidence of Stingers in Young Rugby Players.

    PubMed

    Kawasaki, Takayuki; Ota, Chihiro; Yoneda, Takeshi; Maki, Nobukazu; Urayama, Shingo; Nagao, Masashi; Nagayama, Masataka; Kaketa, Takefumi; Takazawa, Yuji; Kaneko, Kazuo

    2015-11-01

    A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Descriptive epidemiology study. A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for

  18. Return to Play and Decreased Performance After Anterior Cruciate Ligament Reconstruction in National Football League Defensive Players.

    PubMed

    Read, Connor R; Aune, Kyle T; Cain, E Lyle; Fleisig, Glenn S

    2017-07-01

    Anterior cruciate ligament (ACL) injuries occur commonly in football. Recent work has reported ACL reconstruction (ACLR) as one of several orthopaedic procedures with unfavorable outcomes for professional athletes. The performance impact to defensive players after surgery has not been quantified. To quantify the effect of ACLR on the performance of defensive players by comparing them to a cohort of matched controls as well as to measure the effect of ACLR on athletes' career length in the National Football League (NFL). Case-control and cohort study; Level of evidence, 3. Thirty-eight NFL defensive players with a history of ACLR from 2006 to 2012 were identified. For each injured player, a matched control player was identified. Demographic and performance statistics were collected from the online NFL player database. Players who returned after ACLR (n = 23) were compared with players who did not return (n = 15) using t tests and chi-squared analyses. Similarly, players who returned after ACLR (n = 23) were compared with their matched controls with t tests and chi-squared analyses. Two-way repeated-measures analysis of variance was utilized to test for significant differences between performance before and after the season of the injury for the players in the ACLR group who returned (n = 23) and for their matched controls. Kaplan-Meier analysis was performed to test for differences in the rate of retirement between the groups. For all analyses, P values <.05 were considered significant. Approximately 74% (28/38) of athletes who underwent ACLR returned to play at least 1 NFL game, and 61% (23/38) successfully returned to play at least half a season (ie, 8 games). Athletes in the ACLR group who returned retired from the NFL significantly sooner and more often after surgery than their matched controls. In the seasons leading up to their injury, athletes who successfully returned to play started a greater percentage of their games (81%) and made more solo tackles per

  19. Arm pain in youth baseball players: a survey of healthy players.

    PubMed

    Makhni, Eric C; Morrow, Zachary S; Luchetti, Timothy J; Mishra-Kalyani, Pallavi S; Gualtieri, Anthony P; Lee, Randall W; Ahmad, Christopher S

    2015-01-01

    Overuse injury in youth baseball players is increasing in prevalence, and these injuries have been correlated to pitching mechanics and pitch counts/types. Prior studies regarding arm pain in these athletes have focused simply on presence or absence of pain during the season rather than on detailed factors related to arm pain with respect to frequency, severity, and associated performance and psychosocial effect. The goal of this study was to investigate frequency, quality, and effect of arm pain in healthy youth baseball players. The hypothesis was that arm pain will affect a majority of healthy baseball players and will be associated with adverse psychosocial effects. Descriptive epidemiological study. A novel survey focusing on arm pain in youth baseball players was developed for the purpose of this study. Survey questions were formulated by a consortium of trainers, clinicians, and coaches. Surveys were administered to healthy youth baseball players throughout the states of New Jersey and New York. A total of 203 healthy players completed the survey; 23% of players (n=47) reported a prior overuse injury. Only 26% and 20% of players reported that their arm never hurt when throwing or the day after throwing, respectively; 30% of players reported that arm pain at least sometimes caused them to have less fun playing; and 46% of players reported at least once being encouraged to keep playing despite having arm pain. Pitchers were more likely to report arm pain while throwing and the day after throwing and to indicate that arm pain held them back from being a better player (all P<.05). Those with prior overuse injury were more likely to have arm pain while throwing, to have arm fatigue during a game or practice, and to be encouraged to keep playing despite having pain (all P<.05). A majority of healthy (actively competing) youth baseball players report at least some baseline arm pain and fatigue, and many players suffer adverse psychosocial effects from this pain.

  20. Online and offline video game use in adolescents: measurement invariance and problem severity.

    PubMed

    Smohai, Máté; Urbán, Róbert; Griffiths, Mark D; Király, Orsolya; Mirnics, Zsuzsanna; Vargha, András; Demetrovics, Zsolt

    2017-01-01

    Despite the increasing popularity of video game playing, little is known about the similarities and differences between online and offline video game players. The aims of this study were (i) to test the applicability and the measurement invariance of the previously developed Problematic Online Gaming Questionnaire (POGQ) in both online and offline gamers and to (ii) examine the differences in these groups. Video game use habits and POGQ were assessed in a sample of 1,964 (71% male) adolescent videogame players. Those gamers who played at least sometimes in an online context were considered "online gamers," while those who played videogames exclusively offline were considered "offline gamers." Confirmatory factor analysis supported the measurement invariance across online and offline videogame players. According to the multiple indicators multiple causes (MIMIC) model, online gamers were more likely to score higher on overuse, interpersonal conflict, and social isolation subscales of the POGQ. The results of the present study suggest that online and offline gaming can be assessed using the same psychometric instrument. These findings open the possibility for future research studies concerning problematic video gaming to include participants who exclusively play online or offline games, or both. However, the study also identified important structural features about how online and offline gaming might contribute differently to problematic use. These results provide important information that could be utilized in parental education and the prevention program about the possible detrimental consequences of online vs. offline video gaming.

  1. Musculoskeletal injuries among Malaysian badminton players.

    PubMed

    Shariff, A H; George, J; Ramlan, A A

    2009-11-01

    The purpose of this study was to investigate the pattern of musculoskeletal injuries sustained by Malaysian badminton players. This is a retrospective case notes review of all badminton players who attended the National Sports Institute (NSI) Clinic, Kuala Lumpur, Malaysia, and were diagnosed with musculoskeletal injuries. In a two and a half year period, from January 2005 to June 2007, 469 musculoskeletal injuries were diagnosed among badminton players at the NSI Clinic. The mean age of the players who attended the clinic was 19.2 (range 13-52) years. Approximately 60 percent of the injuries occurred in players younger than 20 years of age. The majority of injuries (91.5 percent) were categorised as mild overuse injury and mostly involved the knee. The majority of the injuries sustained by badminton players in this study were due to overuse, primarily in the knee. The majority of the injuries were diagnosed in younger players and occurred during training/practice sessions. There was no difference in terms of incidence and types of injuries between the genders.

  2. Outcomes of microfracture in professional basketball players.

    PubMed

    Cerynik, Douglas L; Lewullis, Gabriel E; Joves, Brian C; Palmer, Michael P; Tom, James A

    2009-09-01

    Surgical treatment for chondral defects of the knee in competitive running and jumping athletes remains controversial. This study evaluated the performance outcomes of professional basketball players in the National Basketball Association (NBA) who underwent microfracture. Data from 24 professional basketball players from 1997 to 2006 was obtained and analyzed. NBA player efficiency ratings (PER) were calculated for two seasons before and after injury. A control group of 24 players was used for comparison. Study group and control group demographics including age, NBA experience, and minutes per game demonstrated no statistical difference. Mean time to return to an NBA game was 30.0 weeks from the time of surgery. The first season after returning to competition PER and minutes per game decreased by 3.5 (P < 0.01) and 4.9 min (P < 0.05), respectively. The 17 players who continued to play two or more seasons after surgery, the average reduction in their PER and minutes per game was 2.7 (P > 0.05) and 3.0 min (P < 0.26), respectively. A multivariant comparison versus controls demonstrated that power rating during the 2 years after surgery decreased by 3.1 (P < 0.01); while minutes per game decreased by 5.2 (P < 0.001). Twenty-one percent (n = 5 of 24) of the players treated with microfracture did not return to competition in an NBA game. On return to competition player performance and minutes per game are diminished.

  3. Protective equipment use among female rugby players.

    PubMed

    Comstock, R Dawn; Fields, Sarah K; Knox, Christy L

    2005-07-01

    Our objective was to assess the prevalence of protective equipment use and the motivation for using protective equipment among a sample of US female rugby players. We surveyed a convenience sample of 234 current US female rugby players from 14 teams participating in a US women's rugby tournament, obtaining self-reported demographic, rugby exposure, and protective equipment use information. Mouthguards were the most commonly used piece of protective equipment: 90.8% of players reported having always worn a mouthguard while playing or practicing rugby within their most recent 3 months of play. Fewer than 15% of players reported having always worn other types of protective equipment. Equipment use varied by playing position. Whereas over 80% of players in all other positions always wore a mouthguard, 66.7% of scrum halves reported always wearing one. Both backs and forwards reported wearing shoulder pads, but only forwards reported always wearing padded headgear. Mouthguards, padded headgear, and shoulder pads were worn "to prevent injury," whereas ankle braces, neoprene sleeves, and athletic tape on joints were worn "to protect a current/recent injury." This is the first study of female rugby players to assess the prevalence of protective equipment use by playing position and the motivation for using protective equipment. With the exception of mouthguards, US female rugby players infrequently use protective equipment. Protective equipment use varies by playing position. Some types of protective equipment appear to be used as primary prevention mechanisms, whereas others are used as secondary or tertiary prevention mechanisms.

  4. Examining Player Anger in World of Warcraft

    NASA Astrophysics Data System (ADS)

    Barnett, Jane; Coulson, Mark; Foreman, Nigel

    This questionnaire study of the sources of anger in World of Warcraft applies classical quantitative measurement scale construction to a new problem, generating a host of questionnaire items that could find use in future studies, and identifying four major categories of events that cause negative effect among players. First, 33 players provided examples of in-game scenarios that had made them angry, and their responses were culled to create a 93-item battery rated by hundreds of player respondents in terms of anger intensity and anger frequency. An iterative process of factor analysis and scale reliability assessment led to a 28-item instrument measuring four anger-provoking factors: Raids/Instances, Griefers, Perceived Time Wasting, and Anti-social Players. These anger-causing scenarios were then illustrated by concrete examples from player and researcher experiences in World of Warcraft. One striking finding is that players become angry at other players' negative behavior, regardless of whether that behavior was intended to harm.

  5. Telecommunications Network Measurements of Online Gambling Behavior in Switzerland: A Feasibility Study.

    PubMed

    Bitar, Raoul; Nordt, Carlos; Grosshans, Martin; Herdener, Marcus; Seifritz, Erich; Mutschler, Jochen

    2017-01-01

    Methodological shortcomings of gambling studies relying on self-report or on data sets derived from gambling operators tend to result in biased conclusions. The aim of this study was to analyze online gambling behavior using a novel network database approach. From October 13 to October 26, 2014, telecommunications network data from a major telecommunications provider in Switzerland were analyzed. Netflows between mobile devices and a poker operator were quantified to measure the gambling duration and session number. Time spent gambling during night and working hours was compared between devices with longest (red group), intermediate (orange group), and shortest gambling time (green group). Online gambling behavior differed depending on overall gambling time, F (2, 3,143). Night and working hours gambling was the highest in the red group (53%), compared to the orange (50.1%) and the green groups (41.5%). Post hoc analyses indicated significant differences between the orange and green groups (p < 0.05). No differences were observed between the red and orange groups (p = 0.850), and the red and green groups (p = 0.053). On mobile devices, distinct gambling patterns were observed depending on the overall gambling time. This methodology could also be used to investigate online gaming, social media use, and online pornography. © 2017 S. Karger AG, Basel.

  6. Experiences of time loss among videogame players: an empirical study.

    PubMed

    Wood, Richard T A; Griffiths, Mark D; Parke, Adrian

    2007-02-01

    Playing videogames is now a major leisure pursuit, yet research in the area is comparatively sparse. Previous correlational evidence suggests that subjective time loss occurs during playing videogames. This study examined experiences of time loss among a relatively large group of gamers (n = 280). Quantitative and qualitative data were collected through an online survey. Results showed that time loss occurred irrespective of gender, age, or frequency of play, but was associated with particular structural characteristics of games such as their complexity, the presence of multi-levels, missions and/or high scores, multiplayer interactions, and plot. Results also demonstrated that time loss could have both positive and negative outcomes for players. Positive aspects of time loss included helping players to relax and temporarily escape from reality. Negative aspects included the sacrificing of other things in their lives, guilty feelings about wasted time, and social conflict. It is concluded that for many gamers, losing track of time is a positive experience and is one of the main reasons for playing videogames.

  7. Does Education Matter? Major League Baseball Players and Longevity

    ERIC Educational Resources Information Center

    Kalist, David E.; Peng, Yingwei

    2007-01-01

    The authors used duration analysis to examine the longevity of Major League Baseball players. Using data on players who were born between 1945 and 1964, the authors found that the hazard rate of death for players who only attended high school was almost 2.0 times higher than those players who attended a 4-year university, evidence that the…

  8. Does Self-Selection Affect Samples’ Representativeness in Online Surveys? An Investigation in Online Video Game Research

    PubMed Central

    van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

    2014-01-01

    Background The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Objective Our objective was to explore the representativeness of a self-selected sample of online gamers using online players’ virtual characters (avatars). Methods All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars’ characteristics were defined using various games’ scores, reported on the WoW’s official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. Results We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Conclusions Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted. PMID:25001007

  9. Virtual Games for Real Learning: Learning Online with Serious Fun.

    ERIC Educational Resources Information Center

    Jasinski, Marie; Thiagarajan, Sivasailam

    2000-01-01

    Focuses on the use of e-mail games for learning. Discusses terminology; reasons for using virtual games; promoting person-to-person interaction online; how to play an e-mail game, including three examples of specific games; player reactions; design components; the functions for facilitating an e-mail game; and the game as an excuse for debriefing.…

  10. Replicator dynamics with turnover of players

    NASA Astrophysics Data System (ADS)

    Juul, Jeppe; Kianercy, Ardeshir; Bernhardsson, Sebastian; Pigolotti, Simone

    2013-08-01

    We study adaptive dynamics in games where players abandon the population at a given rate and are replaced by naive players characterized by a prior distribution over the admitted strategies. We demonstrate how such a process leads macroscopically to a variant of the replicator equation, with an additional term accounting for player turnover. We study how Nash equilibria and the dynamics of the system are modified by this additional term for prototypical examples such as the rock-paper-scissors game and different classes of two-action games played between two distinct populations. We conclude by showing how player turnover can account for nontrivial departures from Nash equilibria observed in data from lowest unique bid auctions.

  11. Parallax Player: a stereoscopic format converter

    NASA Astrophysics Data System (ADS)

    Feldman, Mark H.; Lipton, Lenny

    2003-05-01

    The Parallax Player is a software application that is, in essence, a stereoscopic format converter. Various formats may be inputted and outputted. In addition to being able to take any one of a wide variety of different formats and play them back on many different kinds of PCs and display screens. The Parallax Player has built into it the capability to produce ersatz stereo from a planar still or movie image. The player handles two basic forms of digital content - still images, and movies. It is assumed that all data is digital, either created by means of a photographic film process and later digitized, or directly captured or authored in a digital form. In its current implementation, running on a number of Windows Operating Systems, The Parallax Player reads in a broad selection of contemporary file formats.

  12. Menstrual cycle disorders in female volleyball players.

    PubMed

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  13. Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

    PubMed

    Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

    2015-03-01

    This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

  14. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    PubMed Central

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play. PMID:28352493

  15. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks.

    PubMed

    Kuriyama, Andrew M; Nakatsuka, Austin S; Yamamoto, Loren G

    2017-03-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai'i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play.

  16. Shoulder instability in professional football players.

    PubMed

    Leclere, Lance E; Asnis, Peter D; Griffith, Matthew H; Granito, David; Berkson, Eric M; Gill, Thomas J

    2013-09-01

    Shoulder instability is a common problem in American football players entering the National Football League (NFL). Treatment options include nonoperative and surgical stabilization. This study evaluated how the method of treatment of pre-NFL shoulder instability affects the rate of recurrence and the time elapsed until recurrence in players on 1 NFL team. Retrospective cohort. Medical records from 1980 to 2008 for 1 NFL team were reviewed. There were 328 players included in the study who started their career on the team and remained on the team for at least 2 years (mean, 3.9 years; range, 2-14 years). The history of instability prior to entering the NFL and the method of treatment were collected. Data on the occurrence of instability while in the NFL were recorded to determine the rate and timing of recurrence. Thirty-one players (9.5%) had a history of instability prior to entering the NFL. Of the 297 players with no history of instability, 39 (13.1%) had a primary event at a mean of 18.4 ± 22.2 months (range, 0-102 months) after joining the team. In the group of players with prior instability treated with surgical stabilization, there was no statistical difference in the rate of recurrence (10.5%) or the timing to the instability episode (mean, 26 months) compared with players with no history of instability. Twelve players had shoulder instability treated nonoperatively prior to the NFL. Five of these players (41.7%) had recurrent instability at a mean of 4.4 ± 7.0 months (range, 0-16 months). The patients treated nonoperatively had a significantly higher rate of recurrence (P = 0.02) and an earlier time of recurrence (P = 0.04). The rate of contralateral instability was 25.8%, occurring at a mean of 8.6 months. Recurrent shoulder instability is more common in NFL players with a history of nonoperative treatment. Surgical stabilization appears to restore the rate and timing of instability to that of players with no prior history of instability.

  17. Explosive Strength Imbalances in Professional Basketball Players

    PubMed Central

    Schiltz, Marc; Lehance, Cédric; Maquet, Didier; Bury, Thierry; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2009-01-01

    Context: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. Objective: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. Design: Cohort study. Setting: Academic medical institution. Patients or Other Participants: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. Main Outcome Measure(s): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60°·s−1 and 240°·s−1 and (Fl only) eccentric peak torque at 30°·s−1 and 120°·s−1. Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. Results: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60°·s−1. Knee Ext (60°·s−1) and Fl (eccentric 120°·s−1) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. Conclusions: The relative isokinetic and functional performances of professional basketball players were similar to those of junior

  18. Decomposition of Multi-player Games

    NASA Astrophysics Data System (ADS)

    Zhao, Dengji; Schiffel, Stephan; Thielscher, Michael

    Research in General Game Playing aims at building systems that learn to play unknown games without human intervention. We contribute to this endeavour by generalising the established technique of decomposition from AI Planning to multi-player games. To this end, we present a method for the automatic decomposition of previously unknown games into independent subgames, and we show how a general game player can exploit a successful decomposition for game tree search.

  19. The sounds of handheld audio players.

    PubMed

    Rudy, Susan F

    2007-01-01

    Hearing experts and public health organizations have longstanding hearing safety concerns about personal handheld audio devices, which are growing in both number and popularity. This paper reviews the maximum sound levels of handheld compact disc players, MP3 players, and an iPod. It further reviews device factors that influence the sound levels produced by these audio devices and ways to reduce the risk to hearing during their use.

  20. Shoulder injuries in adolescent rugby players

    PubMed Central

    Hodhody, Ghazal; Mackenzie, Tanya A

    2016-01-01

    Background Rugby is a high-intensity contact sport, frequently causing shoulder injuries. Between the ages of 12 years to 18 years, academy and county level players are being selected for professional contracts, making this is a critical stage of their career. The present study aimed to describe the patterns of injury in adolescent rugby players with shoulder injuries. Methods Academy and county level rugby players in the target age group, over a 7-year period, were included in the present study. Data collected included the mechanism of injury, position and level of play, radiology and surgical findings, and recurrence rate at a minimum of 2 years post-surgery. Results One hundred and sixty-nine cases adhered to the inclusion criteria, with most cases involving two or more pathologies in the shoulder (54%). Forwards sustained more shoulder injuries than backs, incurring more labral injuries. By contrast, backs had a higher incidence of bony pathology. The mechanism of injury frequently correlated with player positions. There was a 21% injury recurrence rate, with forwards (7%) and higher level academy players (11%) most likely to suffer a recurrence. Conclusions Shoulder injury patterns in this important group of adolescent contact athletes are complex, with recurrence rates being higher than those in older rugby players. PMID:27583014

  1. Bridging Media with the Help of Players

    NASA Astrophysics Data System (ADS)

    Nitsche, Michael; Drake, Matthew; Murray, Janet

    We suggest harvesting the power of multiplayer design to bridge content across different media platforms and develop player-driven cross-media experiences. This paper first argues to partially replace complex AI systems with multiplayer design strategies to provide the necessary level of flexibility in the content generation for cross-media applications. The second part describes one example project - the Next Generation Play (NGP) project - that illustrates one practical approach of such a player-driven cross-media content generation. NGP allows players to collect virtual items while watching a TV show. These items are re-used in a multiplayer casual game that automatically generates new game worlds based on the various collections of active players joining a game session. While the TV experience is designed for the single big screen, the game executes on multiple mobile phones. Design and technical implementation of the prototype are explained in more detail to clarify how players carry elements of television narratives into a non-linear handheld gaming experience. The system describes a practical way to create casual game adaptations based on players' personal preferences in a multi-user environment.

  2. Randomness in nonlocal games between mistrustful players

    PubMed Central

    Miller, Carl A.; Shi, Yaoyun

    2017-01-01

    If two quantum players at a nonlocal game G achieve a superclassical score, then their measurement outcomes must be at least partially random from the perspective of any third player. This is the basis for device-independent quantum cryptography. In this paper we address a related question: does a superclassical score at G guarantee that one player has created randomness from the perspective of the other player? We show that for complete-support games, the answer is yes: even if the second player is given the first player’s input at the conclusion of the game, he cannot perfectly recover her output. Thus some amount of local randomness (i.e., randomness possessed by only one player) is always obtained when randomness is certified from nonlocal games with quantum strategies. This is in contrast to non-signaling game strategies, which may produce global randomness without any local randomness. We discuss potential implications for cryptographic protocols between mistrustful parties. PMID:29643748

  3. Creatine supplementation in high school football players.

    PubMed

    McGuine, T A; Sullivan, J C; Bernhardt, D T

    2001-10-01

    To describe creatine supplementation patterns and behaviors associated with creatine supplementation in high school football players. A cross-sectional, multisite, anonymous, descriptive survey was conducted between October 1999 and February 2000. 37 public high schools in Wisconsin. A total of 1,349 high school football players, grades 9-12. Self-reported prevalence of creatine use, as well as perceived benefits and risks. In addition, sources of information and influence regarding creatine supplementation were assessed. 30% of the respondents reported using creatine. Creatine use was lowest in the 9th grade (10.4%) and highest in the 12th grade (50.5%). 41% of the players at small schools stated they used creatine compared with 29% of the players in large schools. Enhanced recovery following a workout was the most likely perceived benefit of creatine supplementation, while dehydration was cited most often as a risk of creatine use. Users were encouraged to take creatine most often by their friends while their parents discouraged creatine use. Creatine use is widespread in high school football players. High school football players who use creatine may not be aware of the risks and benefits associated with creatine supplementation. Sports medicine professionals who work with this population need to educate athletes, coaches, and parents about the use of creatine as a performance-enhancing supplement.

  4. Cortical thinning in former professional soccer players.

    PubMed

    Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2016-09-01

    Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

  5. The audiological health of horn players.

    PubMed

    Wilson, Wayne J; O'Brien, Ian; Bradley, Andrew P

    2013-01-01

    Among orchestral musicians, horn players are one of the most at-risk groups for noise-induced hearing loss (NIHL). To investigate this group further, pure tone audiometry and a 14-item questionnaire were used to assess the hearing health, as well as attitudes and practices regarding hearing conservation, among 142 French horn players attending an international horn conference in Brisbane, Australia. Of this study's French horn players, 11.1% to 22.2%, and 17.7% to 32.9% of those aged ≤40 years, showed some form of hearing loss (corrected for age and gender) typical of NIHL, using conservative versus lenient criteria, respectively. Stepwise multiple regression analyses showed no obvious predictor of hearing loss in this study's participants. Of the 18% of participants who reported using hearing protection, 81% used this protection "sometimes" and 50% used generic, foam, or other inferior forms of protection. Continued efforts to better manage the hearing health of horn players is warranted particularly as any hearing loss will affect a horn player's ability to perform and therefore his or her livelihood. Managing the hearing health of horn players will be challenging, however, with no simple predictor of NIHL loss being identified in this study's sample.

  6. Impact locations and concussion outcomes in high school football player-to-player collisions.

    PubMed

    Kerr, Zachary Y; Collins, Christy L; Mihalik, Jason P; Marshall, Stephen W; Guskiewicz, Kevin M; Comstock, R Dawn

    2014-09-01

    Little research has examined concussion outcomes in terms of impact location (ie, the area on the head in which the impact occurred). This study describes the epidemiology of concussions resulting from player-to-player collision in high school football by impact location. National High School Sports-Related Injury Surveillance Study data (2008/2009-2012/2013) were analyzed to calculate rates and describe circumstances of football concussion (eg, symptomology, symptom resolution time, return to play) resulting from player-to-player collisions by impact location (ie, front-, back-, side-, and top-of-the-head). Most concussions resulting from player-to-player collisions occurred from front-of-the-head (44.7%) and side-of-the-head (22.3%) impacts. Number of symptoms reported, prevalence of reported symptoms, symptom resolution time, and length of time to return to play were not associated with impact location. However, a larger proportion of football players sustaining concussions from top-of-the-head impacts experienced loss of consciousness (8.0%) than those sustaining concussions from impacts to other areas of the head (3.5%) (injury proportion ratio 2.3; 95% confidence interval 1.2-4.2; P = .008). Players had their head down at the time of impact in a higher proportion of concussions caused by top-of-the-head impacts (86.4%) than concussions from impacts to other areas of the head (24.0%) (injury proportion ratio 3.6; 95% confidence interval 3.2-4.0; P < .001). Among high school football players who sustained concussions due to player-to-player collisions, concussion outcomes were generally independent of impact location. Recommended strategies for reducing the proportion of top-of-the-head impacts include improved education regarding tackling with proper "head-up" technique. Copyright © 2014 by the American Academy of Pediatrics.

  7. Collaborate and share: an experimental study of the effects of task and reward interdependencies in online games.

    PubMed

    Choi, Boreum; Lee, Inseong; Choi, Dongseong; Kim, Jinwoo

    2007-08-01

    Today millions of players interact with one another in online games, especially massively multiplayer online role-playing games (MMORPGs). These games promote interaction among players by offering interdependency features, but to date few studies have asked what interdependency design factors of MMORPGs make them fun for players, produce experiences of flow, or enhance player performance. In this study, we focused on two game design features: task and reward interdependency. We conducted a controlled experiment that compared the interaction effects of low and high task-interdependency conditions and low and high reward-interdependency conditions on three dependent variables: fun, flow, and performance. We found that in a low task-interdependency condition, players had more fun, experienced higher levels of flow, and perceived better performance when a low reward-interdependency condition also obtained. In contrast, in a high task-interdependency condition, all of these measures were higher when a high reward-interdependency condition also obtained.

  8. Psychological motives and online games addiction: a test of flow theory and humanistic needs theory for Taiwanese adolescents.

    PubMed

    Wan, Chin-Sheng; Chiou, Wen-Bin

    2006-06-01

    Obviously, the negative impact of online games has received much attention as well as having become a popular research topic. This research explored, from flow theory and humanistic needs theory, the psychological motivations of Taiwanese adolescents who are addicted to online games. The purpose of Study 1 was to investigate the relationship between players' flow state and their online games addiction. The results indicated that flow state was negatively correlated with addictive inclination and it was not a significant predictor for players' subsequent additive inclination. Findings also revealed that the addicts' flow state was significantly lower than the nonaddicts. Thus, flow state might not be the key psychological mechanism of players' addiction. In Study 2, the results showed that the psychological needs of players of online games were close to the two-factor theory which depicts satisfaction and dissatisfaction dimensions. Addicted players' need-gratification was similar to the feature of dissatisfactory factor. That is, the absence of playing online games is more likely to generate sense of dissatisfaction; the addicts' compulsive use of online games seems to stem from the relief of dissatisfaction rather than the pursuit of satisfaction. In contrast, online games tend to provide the nonaddicts with a sense of satisfaction rather than a sense of dissatisfaction.

  9. Decreased interlimb differences in female basketball players.

    PubMed

    Akpinar, Selcuk

    2016-12-01

    Hand preference can be influenced by some factors like sensory information and sports participation. In many sports, it is always desirable to have the similar performance of both hands to adapt to the fast changes of the game. Elite basketball players use their left non-dominant hand more accurately and more frequently during the game compared to amateurs. However, there is no quantitative data to explain this phenomenon. The aim of the study was to test whether participation of long-term basketball training influences interlimb difference and also observed more accurate and more frequent usage of the non-dominant hand in basketball players that can be explained by some kinematic variables during an aiming task. Professional right-handed female basketball players and age-matched non-athletes were asked to reach one of three targets in a virtual reality environment setup with either their non-dominant or dominant hand. Two kinematic parameters depicting motor performance asymmetries were measured: accuracy and hand path deviation from linearity (HPDL). No interlimb differences for basketball players but significant asymmetrical performance for non-athletes were observed. Although the aiming task used in this study is not a basketball specific task, basketball players still displayed better performance compared to non-athletes in both accuracy and HPDL. The current study implies that not only sensorimotor information but also participation of long-term sports activity can modify interlimb difference. Moreover, basketball players having symmetrical motor performance of both hands, which was found in this study, can indirectly explain the more frequent usage of the non-dominant left hand in basketball players.

  10. Sports injuries in Plus League volleyball players.

    PubMed

    Cieśla, E; Dutkiewicz, R; Mgłosiek, M; Nowak-Starz, G; Markowska, M; Jasiński, P; Dudek, J

    2015-06-01

    Although physical activity brings a range of lifelong health benefits, it may also lead to injuries that pose a significant threat to health. It is particularly noticeable in people involved in professional sports where sport-related injuries commonly occur and are associated with intense exercise which aims to improve physical fitness. The article attempts to determine incidence of sports injuries reported by Plus League volleyball players, as well as to identify their most common types and causes. The research project involved 90 Plus League volleyball players aged 18-37 with the average age of 25.11 (SD±5.378). A method of diagnostic survey was applied to collect empirical data by means of questionnaire developed by the authors (researchers). The results were statistically analysed and verified with the analysis of variance (ANOVA) and χ2 test at the significance level (or critical P-value) of P≤0.05. Over 87% of the respondents suffered from at least one sport-related injury. In total, 362 injuries occurred, on average 4.02 injuries per one volleyball player. The most common sports injuries involved ankle or talocrural joint (46 injuries), knee and lower leg muscles (30), interphalangeal articulations of fingers (30) as well as shoulder joint. More than half of the injuries (57%) occurred twice or three times. Volleyball players commonly sustain injuries through contact with an opposing player in competition. Sport-specific injuries may also occur due to exhaustion, lack of rest and undertreated injuries. The most common volleyball-related injuries are primarily talocrural joint, hand and shoulder injuries. Common types of injuries that can affect volleyball players include muscles, joints and ligaments injuries, sprains and strains as well as bruises. Most of these injuries are caused by exhaustion, contact with an opposing player during competition and fatigue. The incidence of sport-related injuries seems to be influenced by such factors as somatic

  11. Event-related potential effects of superior action anticipation in professional badminton players.

    PubMed

    Jin, Hua; Xu, Guiping; Zhang, John X; Gao, Hongwei; Ye, Zuoer; Wang, Pin; Lin, Huiyan; Mo, Lei; Lin, Chong-De

    2011-04-04

    The ability to predict the trajectory of a ball based on the opponent's body kinematics has been shown to be critical to high-performing athletes in many sports. However, little is known about the neural correlates underlying such superior ability in action anticipation. The present event-related potential study compared brain responses from professional badminton players and non-player controls when they watched video clips of badminton games and predicted a ball's landing position. Replicating literature findings, the players made significantly more accurate judgments than the controls and showed better action anticipation. Correspondingly, they showed enlarged amplitudes of two ERP components, a P300 peaking around 350ms post-stimulus with a parietal scalp distribution and a P2 peaking around 250ms with a posterior-occipital distribution. The P300 effect was interpreted to reflect primed access and/or directing of attention to game-related memory representations in the players facilitating their online judgment of related actions. The P2 effect was suggested to reflect some generic learning effects. The results identify clear neural responses that differentiate between different levels of action anticipation associated with sports expertise. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Influence of Pokémon Go on physical activity levels of university players: a cross-sectional study.

    PubMed

    Wong, Fiona Y

    2017-02-22

    The prevalence of overweight is increasing and the effectiveness of various weight management and exercise programs varied. An augmented reality smartphone game, Pokémon Go, appears to increase activity levels of players. This study assessed the players and ex-players' frequencies and durations of staying outdoors, and walking/jogging before and during the time they played Pokémon Go, evaluated the physical activity levels of players, ex-players and non-players, and investigated the potential factors which determined their play statuses. Students in a university answered an online-questionnaire survey. The IPAQ-short form was incorporated to measure vigorous-intensity activities, moderate-intensity activities and walking. Chi square tests were used to compare frequencies and durations of staying outdoors and walking/jogging, health discomforts and physical activity levels between players, ex-players and non-players. Wilcoxon signed ranks tests were performed to assess the changes prior to and during the time when the players and ex-players played Pokémon Go. Logistic regression analyses were performed to assess factors contributing to playing, quitting or not playing Pokémon Go. 644 university students answered the questionnaire. Compared with the ex-players, the players were significantly more frequent to stay outdoors when playing Pokémon Go (P < 0.001), walk/jog to a location to catch Pokémon, to Pokéstops or Gyms (P < 0.005), as well as walking/jogging to hatch eggs (P < 0.001). Players who never or rarely walked/jogged before spent a mean of 108.19 ± 158.21 min/week to walk/jog in order to play the game which is equivalent to burning 357 kcal/week for a 60-kg person walking a moderate pace. Compared with the non-players, players were more likely to be aged 18-25 years [OR (95% CI) 3.28 (1.28-8.40), P = 0.013], never [OR (95% CI) 10.51 (1.12-98.57), P = 0.039] or rarely [OR (95% CI) 4.00 (1.95-8.23), P < 0.001] stayed outdoors and

  13. Online gaming for learning optimal team strategies in real time

    NASA Astrophysics Data System (ADS)

    Hudas, Gregory; Lewis, F. L.; Vamvoudakis, K. G.

    2010-04-01

    This paper first presents an overall view for dynamical decision-making in teams, both cooperative and competitive. Strategies for team decision problems, including optimal control, zero-sum 2-player games (H-infinity control) and so on are normally solved for off-line by solving associated matrix equations such as the Riccati equation. However, using that approach, players cannot change their objectives online in real time without calling for a completely new off-line solution for the new strategies. Therefore, in this paper we give a method for learning optimal team strategies online in real time as team dynamical play unfolds. In the linear quadratic regulator case, for instance, the method learns the Riccati equation solution online without ever solving the Riccati equation. This allows for truly dynamical team decisions where objective functions can change in real time and the system dynamics can be time-varying.

  14. Player Modeling for Intelligent Difficulty Adjustment

    NASA Astrophysics Data System (ADS)

    Missura, Olana; Gärtner, Thomas

    In this paper we aim at automatically adjusting the difficulty of computer games by clustering players into different types and supervised prediction of the type from short traces of gameplay. An important ingredient of video games is to challenge players by providing them with tasks of appropriate and increasing difficulty. How this difficulty should be chosen and increase over time strongly depends on the ability, experience, perception and learning curve of each individual player. It is a subjective parameter that is very difficult to set. Wrong choices can easily lead to players stopping to play the game as they get bored (if underburdened) or frustrated (if overburdened). An ideal game should be able to adjust its difficulty dynamically governed by the player’s performance. Modern video games utilise a game-testing process to investigate among other factors the perceived difficulty for a multitude of players. In this paper, we investigate how machine learning techniques can be used for automatic difficulty adjustment. Our experiments confirm the potential of machine learning in this application.

  15. Injury incidence and balance in rugby players.

    PubMed

    M, Jaco Ras; Puckree, Threethambal

    2014-01-01

    Objective : This study determined and correlated injury incidence and balance in rugby players. A prospective survey with balance testing was conducted on first year rugby academy players (N= 114). Injury incidence, static and dynamic balance were tested pre and post-season using a Biosway portable balance system. The data was analysed using paired and independent samples t-tests at p<0.05, Odds ratios, and Spearman's correlation coefficients. 75.50% participated, 71.40% were 18 years old, and 71.40% were White. Injury was sustained by 83% of players with the knee (25%) most commonly injured. Injury incidence was 1.52 per player with an injury rate of 5.95 injuries per 1000 match playing hours. The Stability Index increased significantly (p=0.03) by 15% in the medial/lateral direction post-season compared to pre-season. Significant differences in post-test anterior posterior and overall static and front and front right dynamic stability between injured and uninjured players were noted. Risk factors for injury included the scrum-half (14.80%) playing position, injuries in the 2nd half of the match (57%), and during contact (67%). Conclusion : Injury incidence was related to static and dynamic balance in forward right direction only.

  16. Injury incidence and balance in rugby players

    PubMed Central

    M, Jaco Ras; Puckree, Threethambal

    2014-01-01

    Objective : This study determined and correlated injury incidence and balance in rugby players. Methods: A prospective survey with balance testing was conducted on first year rugby academy players (N= 114). Injury incidence, static and dynamic balance were tested pre and post-season using a Biosway portable balance system. The data was analysed using paired and independent samples t-tests at p<0.05, Odds ratios, and Spearman’s correlation coefficients. Results: 75.50% participated, 71.40% were 18 years old, and 71.40% were White. Injury was sustained by 83% of players with the knee (25%) most commonly injured. Injury incidence was 1.52 per player with an injury rate of 5.95 injuries per 1000 match playing hours. The Stability Index increased significantly (p=0.03) by 15% in the medial/lateral direction post-season compared to pre-season. Significant differences in post-test anterior posterior and overall static and front and front right dynamic stability between injured and uninjured players were noted. Risk factors for injury included the scrum-half (14.80%) playing position, injuries in the 2nd half of the match (57%), and during contact (67%). Conclusion : Injury incidence was related to static and dynamic balance in forward right direction only. PMID:25674136

  17. Complex network study of Brazilian soccer players

    NASA Astrophysics Data System (ADS)

    Onody, Roberto N.; de Castro, Paulo A.

    2004-09-01

    Although being a very popular sport in many countries, soccer has not received much attention from the scientific community. In this paper, we study soccer from a complex network point of view. First, we consider a bipartite network with two kinds of vertices or nodes: the soccer players and the clubs. Real data were gathered from the 32 editions of the Brazilian soccer championship, in a total of 13411 soccer players and 127 clubs. We find a lot of interesting and perhaps unsuspected results. The probability that a Brazilian soccer player has worked at N clubs or played M games shows an exponential decay while the probability that he has scored G goals is power law. Now, if two soccer players who have worked at the same club at the same time are connected by an edge, then a new type of network arises (composed exclusively by soccer player nodes). Our analysis shows that for this network the degree distribution decays exponentially. We determine the exact values of the clustering coefficient, the assortativity coefficient and the average shortest path length and compare them with those of the Erdös-Rényi and configuration model. The time evolution of these quantities are calculated and the corresponding results discussed.

  18. Game Performance Evaluation in Male Goalball Players

    PubMed Central

    Molik, Bartosz; Morgulec-Adamowicz, Natalia; Kosmol, Andrzej; Perkowski, Krzysztof; Bednarczuk, Grzegorz; Skowroński, Waldemar; Gomez, Miguel Angel; Koc, Krzysztof; Rutkowska, Izabela; Szyman, Robert J

    2015-01-01

    Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level. PMID:26834872

  19. Using cognitive dissonance to induce adolescents' escaping from the claw of online gaming: the roles of personal responsibility and justification of cost.

    PubMed

    Chiou, Wen-Bin; Wan, Chin-Sheng

    2007-10-01

    The negative impact of the Internet on adolescents has received much attention. How to reduce their pathological use of online gaming is also a critical issue. Based on cognitive dissonance theory, two experiments were conducted to examine whether personal responsibility and justification of cost may play crucial factors in impacting adolescent players' attitude change and their willingness to engage in attitude-discrepant behavior. The results of Experiment 1 revealed that adolescent players who felt a strong sense of responsibility appeared to exhibit greater attitude change. In Experiment 2, the findings indicated that players tended to employ justification of cost in order to reduce or eliminate the dissonance between their attitude toward online gaming and invested cost. Adolescent players who perceived a higher cost in online gaming were less willing to engage in attitude-discrepant behavior. Reducing adolescents ' overuse of online gaming can be appreciated through the perspective of cognitive dissonance.

  20. Nutritional requirements of young soccer players.

    PubMed

    Bar-Or, O; Unnithan, V B

    1994-01-01

    The general dietary needs of the young soccer player appear to be similar to those of the adult soccer player. There are, however, several age- and maturation-related differences. Compared with adults, children's daily recommended protein intake (per kg body mass) is higher; during exercise, children's muscles rely more on fat than on carbohydrates, but it is not clear whether young soccer players need higher dietary fat; calculated per kg body mass, the metabolic demands of walking and running are considerably higher in children; and during dehydration, children's core temperature rises faster, which calls for stricter enforcement of hydration. To increase fluid palatability, drinks should be flavoured, according to the child's individual preference. The efficacy and safety of 'carbohydrate loading' have not been studied in children.

  1. Mean Field Games with a Dominating Player

    SciTech Connect

    Bensoussan, A., E-mail: axb046100@utdallas.edu; Chau, M. H. M., E-mail: michaelchaumanho@gmail.com; Yam, S. C. P., E-mail: scpyam@sta.cuhk.edu.hk

    In this article, we consider mean field games between a dominating player and a group of representative agents, each of which acts similarly and also interacts with each other through a mean field term being substantially influenced by the dominating player. We first provide the general theory and discuss the necessary condition for the optimal controls and equilibrium condition by adopting adjoint equation approach. We then present a special case in the context of linear-quadratic framework, in which a necessary and sufficient condition can be asserted by stochastic maximum principle; we finally establish the sufficient condition that guarantees the uniquemore » existence of the equilibrium control. The proof of the convergence result of finite player game to mean field counterpart is provided in Appendix.« less

  2. Cervical joint position sense in rugby players versus non-rugby players.

    PubMed

    Pinsault, Nicolas; Anxionnaz, Marion; Vuillerme, Nicolas

    2010-05-01

    To determine whether cervical joint position sense is modified by intensive rugby practice. A group-comparison study. University Medical Bioengineering Laboratory. Twenty young elite rugby players (10 forwards and 10 backs) and 10 young non-rugby elite sports players. Participants were asked to perform the cervicocephalic relocation test (CRT) to the neutral head position (NHP) that is, to reposition their head on their trunk, as accurately as possible, after full active left and right cervical rotation. Rugby players were asked to perform the CRT to NHP before and after a training session. Absolute and variable errors were used to assess accuracy and consistency of the repositioning for the three groups of Forwards, Backs and Non-rugby players, respectively. The 2 groups of Forwards and Backs exhibited higher absolute and variable errors than the group of Non-rugby players. No difference was found between the two groups of Forwards and Backs and no difference was found between Before and After the training session. The cervical joint position sense of young elite rugby players is altered compared to that of non-rugby players. Furthermore, Forwards and Backs demonstrated comparable repositioning errors before and after a specific training session, suggesting that cervical proprioceptive alteration is mainly due to tackling and not the scrum.

  3. Thirty Percent of Female Footballers Terminate Their Careers Due to Injury - A Retrospective Study Among Former Polish Players.

    PubMed

    Grygorowicz, Monika; Michałowska, Martyna; Jurga, Paulina; Piontek, Tomasz; Jakubowska, Honorata; Kotwicki, Tomasz

    2017-09-27

    Female football is becoming an increasingly popular women's team sports discipline around the world. The Women's Football Committee in Polish Football Association (WFC_PFA) has developed a long-term strategic plan to popularize the discipline across the country and enhance girls' participation. On one hand, it is postulated to increase the number of female footballers, and on the other hand it is crucial to decrease the number of girls quitting football prematurely. To find the reasons for sports career termination among female football players. cross-sectional with retrospective information about reasons of career termination. On-line questionnaire was filled out by on-line access. Ninety-three former female footballers. factors leading to career termination. Participants completed the on-line questionnaire. The analysis was performed referring to two groups: "injury group" - in which the injury was the main reason for quitting football, and "other group" - in which the female player stopped playing football due to all other factors. Thirty percent of former Polish female football players terminated their career due to a long-term treatment for an injury. Over 27 percent (27.7%) females had ended their careers because they were not able to reconcile sports with work/studying. Over 10 percent (10.8%) of former football players reported that becoming a wife and/or mother was the reason for career termination. Losing motivation and interest in sport was reported by 9.2%(n=6) of present study participants who decided to terminate the career due to non-injury reasons. The results clearly show that more effort is needed to support female football players, especially after an injury, so that they do not quit the sport voluntarily.

  4. Prospective Player-Reported Injuries in Female Youth Fast-Pitch Softball Players.

    PubMed

    Smith, Matthew V; Davis, Randi; Brophy, Robert H; Prather, Heidi; Garbutt, Jane; Wright, Rick W

    2015-01-01

    There is a scarcity of literature evaluating injuries in youth fast-pitch softball players. To perform a descriptive analysis of player-reported injuries in youth fast-pitch softball position players and pitchers during a single select-level season. Prospective observation cohort study. Level 3. Ninety-eight athletes (48 pitchers, 50 position players) were followed for a single select fast-pitch softball season. Study participants completed web-based surveys every 3 weeks reporting injuries related to participation in fast-pitch softball. Injury was defined as pain causing cessation of participation in the current game or practice that prevents the player's return to that session or any pain that causes cessation of a player's customary participation on the day after the day of onset. The median age of the study participants was 14 years (range, 9-18 years). There were 49 reported injuries in 98 athletes. The average age was 13 years for those not injured and 14 years for those who were injured (P < 0.02). There were 31 injuries that were not related to pitching: 19 occurred in position players and 12 occurred in pitchers; 70% of these injuries were to the lower extremity. The proportion of injuries not related to pitching was significantly greater than the proportion of injuries related to pitching (P < 0.02). Eighteen injuries among the 48 pitchers (38%) were directly attributed to pitching. Among the 18 pitching injuries, 11 (61%) involved the shoulder. The majority (78%) of injuries related to pitching occurred in the first 6 weeks of the season. There was a high incidence of injury in this prospective cohort of youth select-level fast-pitch softball players. Better off-season and preseason conditioning may be a key factor for reducing pitching injuries. Recognition of injury patterns in fast-pitch softball players is critical to developing strategies to keep these athletes competing safely. © 2015 The Author(s).

  5. Player and Game Characteristics and Head Impacts in Female Youth Ice Hockey Players.

    PubMed

    Reed, Nick; Taha, Tim; Greenwald, Richard; Keightley, Michelle

    2017-08-01

      Despite the growing popularity of ice hockey among female youth and interest in the biomechanics of head impacts in sport, the head impacts sustained by this population have yet to be characterized.   To describe the number of, biomechanical characteristics of, and exposure to head impacts of female youth ice hockey players during competition and to investigate the influences of player and game characteristics on head impacts.   Cohort study.   Twenty-seven female youth ice hockey players (mean age = 12.5 ± 0.52 years) wore instrumented ice hockey helmets during 66 ice hockey games over a 3-year period. Data specific to player, game, and biomechanical head impact characteristics were recorded. A multiple regression analysis identified factors most associated with head impacts of greater frequency and severity.   A total of 436 total head impacts were sustained during 6924 minutes of active ice hockey participation (0.9 ± 0.6 impacts per player per game; range, 0-2.1). A higher body mass index (BMI) significantly predicted a higher number of head impacts sustained per game (P = .008). Linear acceleration of head impacts was greater in older players and those who played the forward position, had a greater BMI, and spent more time on the ice (P = .008), whereas greater rotational acceleration was present in older players who had a greater BMI and played the forward position (P = .008). During tournament games, increased ice time predicted increased severity of head impacts (P = .03).   This study reveals for the first time that head impacts are occurring in female youth ice hockey players, albeit at a lower rate and severity than in male youth ice hockey players, despite the lack of intentional body checking.

  6. Checkbook Online

    Science.gov Websites

    Search the Division of Finance site DOF State of Alaska Finance Home Content Area Accounting Charge Cards Checkbook Online Overview The State of Alaska is publishing information from the statewide accounting system mission of the Division of Finance is to provide accounting, payroll, and travel services for State

  7. Online 1990.

    ERIC Educational Resources Information Center

    Goldstein, Morris

    This paper examines the co-existence of online and CD-ROM technologies in terms of their existing pricing structures, marketing strategies, functionality, and future roles. "Fixed Price Unlimited Usage" (FPUU) pricing and flat-rate pricing are discussed as viable alternatives to current pricing practices. In addition, it is argued that the…

  8. Symptoms and risk factors of depression during and after the football career of elite female players

    PubMed Central

    Prinz, Birgit; Dvořák, Jiří; Junge, Astrid

    2016-01-01

    Background The mental health of elite athletes has received increasing attention in recent years, but no study has evaluated the career–time prevalence of depression, and very few have analysed risk factors of mental health problems during or after the career. Methods 157 (response rate 64.1%) female players who played in the German First League answered an anonymous online survey on details of their football career, stressful and helpful conditions, depression and need of psychotherapeutic support during and after the football career. Results The career–time prevalence of depression symptoms was 32.3%. Significant differences in the average depression score were observed for playing positions (F=2.75; p<0.05) and levels of play (F=3.53; p<0.01). About half of the players (49.7%) stated ‘conflicts with coach/management’ as an important reason for their low in moods, followed by ‘low in performance/injury’ (48.4%) and ‘too little support/acknowledgement by the coach’ (40.0%). ‘Psychological strain/stress’ (46.5%) was (after injury) the second most important reason for lows in performance. During their career, almost 40% of players wanted or needed psychological support, but only 10% received it. After their career, the percentage of players wanting or needing psychological support decreased to 24%, of whom 90% received it. Conclusions The high prevalence of depression symptoms in combination with low use of psychotherapy during the career shows the need for de-stigmatisation of mental health issues in elite football. Furthermore, it seems very important to educate coaches, physicians, physiotherapists and club managers to recognise and prevent mental health problems of their players. PMID:27900184

  9. A comparison of static near stereo acuity in youth baseball/softball players and non-ball players.

    PubMed

    Boden, Lauren M; Rosengren, Kenneth J; Martin, Daniel F; Boden, Scott D

    2009-03-01

    Although many aspects of vision have been investigated in professional baseball players, few studies have been performed in developing athletes. The issue of whether youth baseball players have superior stereopsis to nonplayers has not been addressed specifically. The purpose of this study was to determine if youth baseball/softball players have better stereo acuity than non-ball players. Informed consent was obtained from 51 baseball/softball players and 52 non-ball players (ages 10 to 18 years). Subjects completed a questionnaire, and their static near stereo acuity was measured using the Randot Stereotest (Stereo Optical Company, Chicago, Illinois). Stereo acuity was measured as the seconds of arc between the last pair of images correctly distinguished by the subject. The mean stereo acuity score was 25.5 +/- 1.7 seconds of arc in the baseball/softball players and 56.2 +/- 8.4 seconds of arc in the non-ball players. This difference was statistically significant (P < 0.00001). In addition, a perfect stereo acuity score of 20 seconds of arc was seen in 61% of the ball players and only 23% of the non-ball players (P = 0.0001). Youth baseball/softball players had significantly better static stereo acuity than non-ball players, comparable to professional ball players.

  10. Concussion Incidences and Severity in Secondary School Varsity Football Players.

    ERIC Educational Resources Information Center

    Gerberich, Susan Goodwin; And Others

    1983-01-01

    Study of Minnesota high school football players found an injury rate of 78 per 100 players; 19/100 players reported a concussion experience characterized by loss of consciousness/awareness. Of these, 69 percent returned to play the same day. Illegal blocking and tackling contributed to increased concussion. Lasting effects were prevalent. (GC)

  11. Assessment of Cardiovascular Risk in Collegiate Football Players and Nonathletes

    ERIC Educational Resources Information Center

    Dobrosielski, Devon A.; Rosenbaum, Daryl; Wooster, Benjamin M.; Merrill, Michael; Swanson, John; Moore, J. Brian; Brubaker, Peter H.

    2010-01-01

    Collegiate American football players may be at risk for cardiovascular disease. Objective: To compare cardiovascular disease risk factors and cardiovascular structure and function parameters of football players, stratified by position, to a group of sedentary, nonathletes. Participants: Twenty-six collegiate football players and 13 nonathletes…

  12. High School Rugby Players' Perception of Coaching Effectiveness

    ERIC Educational Resources Information Center

    Broodryk, Retief; van den Berg, Pieter Hendrick

    2011-01-01

    The aims of this study were firstly to determine the players' perceptions of their respective coaches' coaching effectiveness and secondly, determine the difference between big and small schools of the players' perceptions of their respective coaches' coaching effectiveness. Four hundred and seventy six players from 22 schools were asked to fill…

  13. Training Patterns of Wheelchair Basketball Players in Turkey

    ERIC Educational Resources Information Center

    Tatar, Yasar

    2008-01-01

    The aim of this study was to analyze technical drills, warm-up and cool-down exercises used by wheelchair basketball players of the Turkish league in relation to training sessions. 33 male wheelchair basketball players participated in the study (mean age 26.6[plus or minus]5,95 years). All players reported that they used warm-up exercises before…

  14. Clug; Community Land Use Game. Player's Manual with Selected Readings.

    ERIC Educational Resources Information Center

    Feldt, Allan G.

    CLUG (Community Land Use Game) is designed to provide players with an understanding of several underlying factors affecting the growth of an urban region. It has been used with players from junior high to graduate school and also with non-students. It unites concepts from sociology, economics, and geography. Players invest in land, construct…

  15. A Player-Centered Approach to Coaching

    ERIC Educational Resources Information Center

    de Souza, Adriano; Oslin, Judy

    2008-01-01

    The purpose of this article is to describe a player-centered approach (PCA), highlighting its qualities, and then to provide examples of its application in coaching and teaching sport. Most of the examples relate to the game of volleyball, but many of the recommendations and examples can be applied to most team sports. The article will conclude…

  16. Are squash players protecting their eyes?

    PubMed

    Eime, R M; Finch, C F; Sherman, C A; Garnham, A P

    2002-09-01

    To determine factors associated with adult squash players' protective eyewear behaviours. A survey of 303 players (aged >or =18 years) was conducted at three squash venues in Melbourne, Australia over a three week period in June 2000 to obtain information about protective eyewear use. Of 303 participants the response rate was 98.1%; 66.1% were males, with a mean age of 40.5 years. The majority (68.4%) had played squash for 10 years or more. Although 18.8% of players reported using protective eyewear, only 8.9% reported wearing approved eyewear. Both age group (p<0.05) and years of squash experience (p<0.01) were significantly associated with any eyewear use. The two main influences were personal experience of eye injuries (50.0%) and knowledge of eye injury risk (33.9%). A commonly reported barrier was restriction of vision (34.2%). These findings demonstrate a low prevalence of voluntary use of appropriate protective eyewear. Future prevention strategies incorporating education campaigns should focus on increasing players' knowledge of risks. The barriers to use and misconceptions about which types of eyewear is most protective need to be addressed as a priority.

  17. Mental Rotation Performance in Male Soccer Players

    PubMed Central

    Jansen, Petra; Lehmann, Jennifer; Van Doren, Jessica

    2012-01-01

    It is the main goal of this study to investigate the visual-spatial cognition in male soccer players. Forty males (20 soccer players and 20 non-athletes) solved a chronometric mental rotation task with both cubed and embodied figures (human figures, body postures). The results confirm previous results that all participants had a lower mental rotation speed for cube figures compared to embodied figures and a higher error rate for cube figures, but only at angular disparities greater than 90°. It is a new finding that soccer–players showed a faster reaction time for embodied stimuli. Because rotation speed did not differ between soccer-players and non-athletes this finding cannot be attributed to the mental rotation process itself but instead to differences in one of the following processes which are involved in a mental rotation task: the encoding process, the maintanence of readiness, or the motor process. The results are discussed against the background of the influence on longterm physical activity on mental rotation and the context of embodied cognition. PMID:23119073

  18. Low Back Pain in a Tennis Player.

    ERIC Educational Resources Information Center

    Bracker, Mark; And Others

    1988-01-01

    A group of physicians meet to discuss a case in which a middle-aged tennis player suffers from low back pain. The diagnosis, treatment and management of the case are discussed. The article is one in an occasional series. (JL)

  19. Knee injuries in women collegiate rugby players.

    PubMed

    Levy, A S; Wetzler, M J; Lewars, M; Laughlin, W

    1997-01-01

    We evaluated the prevalence and patterns of knee injuries in 810 women collegiate rugby players. Injuries that resulted in players missing at least one game were recorded and a questionnaire was used to delineate players' rugby and knee injury history. There were 76 total knee injuries in 58,296 exposures. This resulted in a 1.3 knee injury rate per 1000 exposures. Twenty-one anterior cruciate ligament tears were reported for a 0.36 incidence per 1000 exposures. Other injuries included meniscal tears (25), medical collateral ligament sprains (23), patellar dislocations (5), and posterior cruciate ligament tears (2). Sixty-one percent of the medial collateral ligament sprains occurred in rugby forwards and 67% of anterior cruciate ligament tears occurred in rugby backs. All other injuries occurred with equal frequency in backs and forwards. This study demonstrates that knee injury rates in women's collegiate rugby are similar to those reported for other women's collegiate sports. The overall rate of anterior cruciate ligament injury in women's rugby, however, is slightly higher than that reported for women soccer and basketball players.

  20. Motivational Traits of Elite Young Soccer Players

    ERIC Educational Resources Information Center

    Stewart, Craig; Meyers, Michael C.

    2004-01-01

    Among the most overlooked aspects in the development of elite young soccer players is that of specific psychological traits. Of those traits, motivation has important implications for programs whose objectives are identification and cultivation of young, skilled performers. The growth in popularity of soccer by youth and the successes experienced…

  1. Online computer gaming: a comparison of adolescent and adult gamers.

    PubMed

    Griffiths, M D; Davies, Mark N O; Chappell, Darren

    2004-02-01

    Despite the growing popularity of online game playing, there have been no surveys comparing adolescent and adult players. Therefore, an online questionnaire survey was used to examine various factors of online computer game players (n = 540) who played the most popular online game Everquest. The survey examined basic demographic information, playing frequency (i.e. amount of time spent playing the game a week), playing history (i.e. how long they had been playing the game, who they played the game with, whether they had ever gender swapped their game character, the favourite and least favourite aspects of playing the game, and what they sacrifice (if anything) to play the game. Results showed that adolescent gamers were significantly more likely to be male, significantly less likely to gender swap their characters, and significantly more likely to sacrifice their education or work. In relation to favourite aspects of game play, the biggest difference between the groups was that significantly more adolescents than adults claimed their favourite aspect of playing was violence. Results also showed that in general, the younger the player, the longer they spent each week playing.

  2. Massively Multiplayer Online Games as Living Laboratories: Opportunities and Pitfalls

    NASA Astrophysics Data System (ADS)

    Ducheneaut, Nicolas

    The digital nature of online games makes them particularly amenable to large-scale, automated data collection and analysis; so researchers have begun to use them as living laboratories to test or refine the existing theories of human behavior. On the basis of several years of intensive data collection in several massively multiplayer online games, this chapter addresses three problems concerning validity and generalizability that must be taken into account. First, each game has a set of laws that steer player behavior, thereby introducing confounding factors that have to be taken into account by the researcher. Second, games attract skewed samples of players, and players may adopt transformed personalities inside the game world, which puts into question the validity of extending findings from observations in the digital realm into the physical one. Third, the lack of a clear boundary defining the "game space," illustrated by the many websites and forums for popular games, raises the question of whether online games themselves capture the totality of the user's experience. The problematic mapping between "real-world" behaviors and those in online games presents research opportunities as well as pitfalls that need to be avoided.

  3. Robust Adaptive Dynamic Programming of Two-Player Zero-Sum Games for Continuous-Time Linear Systems.

    PubMed

    Fu, Yue; Fu, Jun; Chai, Tianyou

    2015-12-01

    In this brief, an online robust adaptive dynamic programming algorithm is proposed for two-player zero-sum games of continuous-time unknown linear systems with matched uncertainties, which are functions of system outputs and states of a completely unknown exosystem. The online algorithm is developed using the policy iteration (PI) scheme with only one iteration loop. A new analytical method is proposed for convergence proof of the PI scheme. The sufficient conditions are given to guarantee globally asymptotic stability and suboptimal property of the closed-loop system. Simulation studies are conducted to illustrate the effectiveness of the proposed method.

  4. Physiological characteristics of elite soccer players.

    PubMed

    Tumilty, D

    1993-08-01

    Soccer is one of the most popular sports in the world. There is still much uncertainty and debate surrounding its physiological requirements because emphasis is on skills to the neglect of fitness, conservative training methods and the difficulty of studying the sport scientifically. The frequently found values for total distance covered in a game of about 10 km and an above-average, though not outstanding, maximum oxygen uptake of 60 ml/kg/min suggest a moderate overall aerobic demand. A comparison of top teams and players with less able participants indicates that the components of anaerobic fitness-speed, power, strength and the capacity of the lactic acid system may differentiate better between the 2 groups. Generally, there is a reduction in the level of activity in the second half of games compared with the first. There is some evidence that increased aerobic fitness may help counteract this. Progressively lower muscle glycogen stores are one likely cause of reduction in activity, and nutrition also appears to be a key factor in minimising performance deterioration, both in terms of overall diet and, more particularly, the ingestion of carbohydrates immediately before, during and after a game. There are evolutionary trends in the sport such as greater frequency of games, changes in the roles of players, and new strategies and tactics which are placing increasing demands on the all-round fitness of players. Many studies indicate scope for improvement in player fitness. The challenge for coaches and players is to meet these fitness requirements without sacrificing the skill work which makes the sport unique.

  5. Hamstring Injuries in Professional Football Players

    PubMed Central

    Cohen, Steven B.; Towers, Jeffrey D.; Zoga, Adam; Irrgang, Jay J.; Makda, Junaid; Deluca, Peter F.; Bradley, James P.

    2011-01-01

    Background: Magnetic resonance imaging (MRI) allows for detailed evaluation of hamstring injuries; however, there is no classification that allows prediction of return to play. Purpose: To correlate time for return to play in professional football players with MRI findings after acute hamstring strains and to create an MRI scoring scale predictive of return to sports. Study Design: Descriptive epidemiologic study. Methods: Thirty-eight professional football players (43 cases) sustained acute hamstring strains with MRI evaluation. Records were retrospectively reviewed, and MRIs were evaluated by 2 musculoskeletal radiologists, graded with a traditional radiologic grade, and scored with a new MRI score. Results were correlated with games missed. Results: Players missed 2.6 ± 3.1 games. Based on MRI, the hamstring injury involved the biceps femoris long head in 34 cases and the proximal and distal hamstrings in 25 and 22 cases, respectively. When < 50% of the muscle was involved, the average number of games missed was 1.8; if > 75%, then 3.2. Ten players had retraction, missing 5.5 games. By MRI, grade I injuries yielded an average of 1.1 missed games; grade II, 1.7; and grade III, 6.4. Players who missed 0 or 1 game had an MRI score of 8.2; 2 or 3 games, 11.1; and 4 or more games, 13.9. Conclusions: Rapid return to play (< 1 week) occurred with isolated long head of biceps femoris injures with < 50% of involvement and minimal perimuscular edema, correlating to grade I radiologic strain (MRI score < 10). Prolonged recovery (missing > 2 or 3 games) occurs with multiple muscle injury, injuries distal to musculotendinous junction, short head of biceps injury, > 75% involvement, retraction, circumferential edema, and grade III radiologic strain (MRI score > 15). Clinical Relevance: MRI grade and this new MRI score are useful in determining severity of injury and games missed—and, ideally, predicting time missed from sports. PMID:23016038

  6. The architecture of the chess player's brain.

    PubMed

    Hänggi, Jürgen; Brütsch, Karin; Siegel, Adrian M; Jäncke, Lutz

    2014-09-01

    The game of chess can be seen as a typical example for an expertise task requiring domain-specific training and experience. Despite intensive behavioural studies the neural underpinnings of chess performance and expertise are not entirely understood. A few functional neuroimaging studies have shown that expert chess players recruit different psychological functions and activate different brain areas while they are engaged in chess-related activities. Based on this functional literature, we predicted to find morphological differences in a network comprised by parietal and frontal areas and especially the occipito-temporal junction (OTJ), fusiform gyrus, and caudate nucleus. Twenty expert chess players and 20 control subjects were investigated using voxel-based and surface-based morphometry as well as diffusion tensor imaging. Grey matter volume and cortical thickness were reduced in chess players compared with those of control men in the OTJ and precunei. The volumes of both caudate nuclei were not different between groups, but correlated inversely with the years of chess playing experience. Mean diffusivity was increased in chess players compared with that of controls in the left superior longitudinal fasciculus and the Elo score (a chess tournament ranking) was inversely related to mean diffusivity within the right superior longitudinal fasciculus. To the best of our knowledge we showed for the first time that there are specific differences in grey and white matter morphology between chess players and control subjects in brain regions associated with cognitive functions important for playing chess. Whether these anatomical alterations are the cause or consequence of the intensive and long-term chess training and practice remains to be shown in future studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Unpopular, overweight, and socially inept: reconsidering the stereotype of online gamers.

    PubMed

    Kowert, Rachel; Festl, Ruth; Quandt, Thorsten

    2014-03-01

    Online gaming has become an activity associated with a highly specific, caricatured, and often negative image. This "stereotype" has permeated the collective consciousness, as online gamers have become common caricatures in popular media. A lack of comprehensive demographic inquiries into the online gaming population has made it difficult to dispute these stereotypical characteristics and led to rising concerns about the validity of these stereotypes. The current study aims to clarify the basis of these negative characterizations, and determine whether online video game players display the social, physical, and psychological shortcomings stereotypically attributed them. Sampling and recruiting was conducted using a two-stage approach. First, a representative sample of 50,000 individuals aged 14 and older who were asked about their gaming behavior in an omnibus telephone survey. From this sample, 4,500 video game players were called for a second telephone interview, from which the current data were collected. Only those participants who completed all of the questions relating to video game play were retained for the current analysis (n=2,550). Between- and within-group analyses were enlisted to uncover differences between online, offline, and nongame playing communities across varying degrees of involvement. The results indicate that the stereotype of online gamers is not fully supported empirically. However, a majority of the stereotypical attributes was found to hold a stronger relationship with more involved online players than video game players as a whole, indicating an empirical foundation for the unique stereotypes that have emerged for this particular subgroup of video game players.

  8. Prospective study of injury in volleyball players: 6 year results.

    PubMed

    Pastor, M F; Ezechieli, M; Classen, L; Kieffer, O; Miltner, O

    2015-01-01

    The volleyball game has a high complexity and thus entails a lot of strain to the players. Due to this high and different training and competition strain comprehensive and individual training plans should be developed with competing training objectives in order to prevent injuries. The aim of the study was to analyse prospectively over six seasons the acute and overuse injuries of a German male professional volleyball team. The study included 34 male national league players from season the 2007/08 to 2012/13. All players received a sport medicine examination and a functional diagnosis before each season. Based on the results the players received an individual training plan. The players suffered 186 injuries. The prevalence of acute injuries was 1.94 per player and overuse injuries 0.64 per player. The incidence of acute injuries was 3.3/1000 h volleyball and overuse injuries 1.08/1000 h volleyball. The largest number of injuries was found in the spine. The players had most likely minor injuries. The players had significantly fewer injuries in their second season (1.92) than in their first season (3.25; p= 0.004). It could be concluded that volleyball is a sport with a relative low prevalence of injuries compared to other team sports. The prevalence of injury is 2.58 per player. Due to an injury a player dropped out 16.91 days per season. An individual training program seems to reduce the incidence of injury.

  9. Exploring design features for enhancing players' challenge in strategy games.

    PubMed

    Hsu, Shang Hwa; Wen, Ming-Hui; Wu, Muh-Cherng

    2007-06-01

    This paper examines how to make a player feel more challenged in a strategic computer game. It is hypothesized that information availability and resource advantage affect play difficulty, which in turn affects the challenge experienced. The difficulty of play can be defined in terms of the mental workload that players experience and the physical effort that players exert. Forty-five male college and graduate students participated in a 3 x 3 (information availability x resource advantage) between-subjects factorial design experiment. This experiment measured player mental workload, physical effort, and challenge. The results indicate that information availability affects player mental workload, and resource advantage affects levels of player physical effort, respectively. Moreover, the relationship between mental workload and challenge was found to be an inverted U-shaped curve; in other words, too much or too little mental workload may decrease player challenge. The relationship between physical effort and challenge exhibited similar characteristics.

  10. Protective Equipment and Player Characteristics Associated With the Incidence of Sport-Related Concussion in High School Football Players

    PubMed Central

    McGuine, Timothy A.; Hetzel, Scott; McCrea, Michael; Brooks, M. Alison

    2015-01-01

    Background The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. Purpose To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Design Cohort study; Level of evidence, 2. Methods Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players’ demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. Results A total of 2081 players (grades 9–12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%–11.0%]), Schutt (680, 8.7% [6.7%–11.1%]), or Xenith (436, 9.2% [6.7%–12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20–2.37], P <.001) than in players who wore a generic mouth guard. The rate of SRC was also higher (HR = 1.96 [95% CI, 1.40–2.73], P <.001) in players who had sustained an SRC within the previous 12 months (15.1% of the 259 players [95% CI, 11.0%–20.1%]) than in players without a previous SRC (8.2% of the 2028 players [95% CI, 7.1%–9.5%]). Conclusion Incidence of SRC was similar

  11. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    PubMed

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  12. ComVisMD - compact visualization of multidimensional data: experimenting with cricket players data

    NASA Astrophysics Data System (ADS)

    Dandin, Shridhar B.; Ducassé, Mireille

    2018-03-01

    Database information is multidimensional and often displayed in tabular format (row/column display). Presented in aggregated form, multidimensional data can be used to analyze the records or objects. Online Analytical database Processing (OLAP) proposes mechanisms to display multidimensional data in aggregated forms. A choropleth map is a thematic map in which areas are colored in proportion to the measurement of a statistical variable being displayed, such as population density. They are used mostly for compact graphical representation of geographical information. We propose a system, ComVisMD inspired by choropleth map and the OLAP cube to visualize multidimensional data in a compact way. ComVisMD displays multidimensional data like OLAP Cube, where we are mapping an attribute a (first dimension, e.g. year started playing cricket) in vertical direction, object coloring based on b (second dimension, e.g. batting average), mapping varying-size circles based on attribute c (third dimension, e.g. highest score), mapping numbers based on attribute d (fourth dimension, e.g. matches played). We illustrate our approach on cricket players data, namely on two tables Country and Player. They have a large number of rows and columns: 246 rows and 17 columns for players of one country. ComVisMD’s visualization reduces the size of the tabular display by a factor of about 4, allowing users to grasp more information at a time than the bare table display.

  13. Circular RNA: an emerging key player in RNA world.

    PubMed

    Meng, Xianwen; Li, Xue; Zhang, Peijing; Wang, Jingjing; Zhou, Yincong; Chen, Ming

    2017-07-01

    Insights into the circular RNA (circRNA) exploration have revealed that they are abundant in eukaryotic transcriptomes. Diverse genomic regions can generate different types of RNA circles, implying their diversity. Covalently closed loop structures elevate the stability of this new type of noncoding RNA. High-throughput sequencing analyses suggest that circRNAs exhibit tissue- and developmental-specific expression, indicating that they may play crucial roles in multiple cellular processes. Strikingly, several circRNAs could function as microRNA sponges and regulate gene transcription, highlighting a new class of important regulators. Here, we review the recent advances in knowledge of endogenous circRNA biogenesis, properties and functions. We further discuss the current findings about circRNAs in human diseases. In plants, the roles of circRNAs remain a mystery. Online resources and bioinformatics identification of circRNAs are essential for the analysis of circRNA biology, although different strategies yield divergent results. The understanding of circRNA functions remains limited; however, circRNAs are enriching the RNA world, acting as an emerging key player. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Reinforcement learning in professional basketball players

    PubMed Central

    Neiman, Tal; Loewenstein, Yonatan

    2011-01-01

    Reinforcement learning in complex natural environments is a challenging task because the agent should generalize from the outcomes of actions taken in one state of the world to future actions in different states of the world. The extent to which human experts find the proper level of generalization is unclear. Here we show, using the sequences of field goal attempts made by professional basketball players, that the outcome of even a single field goal attempt has a considerable effect on the rate of subsequent 3 point shot attempts, in line with standard models of reinforcement learning. However, this change in behaviour is associated with negative correlations between the outcomes of successive field goal attempts. These results indicate that despite years of experience and high motivation, professional players overgeneralize from the outcomes of their most recent actions, which leads to decreased performance. PMID:22146388

  15. Telemetry and Communication IP Video Player

    NASA Technical Reports Server (NTRS)

    OFarrell, Zachary L.

    2011-01-01

    Aegis Video Player is the name of the video over IP system for the Telemetry and Communications group of the Launch Services Program. Aegis' purpose is to display video streamed over a network connection to be viewed during launches. To accomplish this task, a VLC ActiveX plug-in was used in C# to provide the basic capabilities of video streaming. The program was then customized to be used during launches. The VLC plug-in can be configured programmatically to display a single stream, but for this project multiple streams needed to be accessed. To accomplish this, an easy to use, informative menu system was added to the program to enable users to quickly switch between videos. Other features were added to make the player more useful, such as watching multiple videos and watching a video in full screen.

  16. Evolutionary game theory: molecules as players.

    PubMed

    Bohl, Katrin; Hummert, Sabine; Werner, Sarah; Basanta, David; Deutsch, Andreas; Schuster, Stefan; Theissen, Günter; Schroeter, Anja

    2014-12-01

    In this and an accompanying paper we review the use of game theoretical concepts in cell biology and molecular biology. This review focuses on the subcellular level by considering viruses, genes, and molecules as players. We discuss in which way catalytic RNA can be treated by game theory. Moreover, genes can compete for success in replication and can have different strategies in interactions with other genetic elements. Also transposable elements, or "jumping genes", can act as players because they usually bear different traits or strategies. Viruses compete in the case of co-infecting a host cell. Proteins interact in a game theoretical sense when forming heterodimers. Finally, we describe how the Shapley value can be applied to enzymes in metabolic pathways. We show that game theory can be successfully applied to describe and analyse scenarios at the molecular level resulting in counterintuitive conclusions.

  17. Social interactions in massively multiplayer online role-playing gamers.

    PubMed

    Cole, Helena; Griffiths, Mark D

    2007-08-01

    To date, most research into massively multiplayer online role-playing games (MMORPGs) has examined the demographics of play. This study explored the social interactions that occur both within and outside of MMORPGs. The sample consisted of 912 self-selected MMORPG players from 45 countries. MMORPGs were found to be highly socially interactive environments providing the opportunity to create strong friendships and emotional relationships. The study demonstrated that the social interactions in online gaming form a considerable element in the enjoyment of playing. The study showed MMORPGs can be extremely social games, with high percentages of gamers making life-long friends and partners. It was concluded that virtual gaming may allow players to express themselves in ways they may not feel comfortable doing in real life because of their appearance, gender, sexuality, and/or age. MMORPGs also offer a place where teamwork, encouragement, and fun can be experienced.

  18. Seasonal Mood Disturbances in Collegiate Hockey Players

    PubMed Central

    Rosen, Lionel W.; Shafer, Christine L.; Smokler, Carol; Carrier, David; McKeag, Douglas B.

    1996-01-01

    Objective: The purpose of this paper is to: 1) describe the seasonal affective disorder syndrome using a case illustration, 2) provide a simple and reliable method for identifying seasonal affective disorder, and 3) provide data as to the prevalence of the syndrome in a subset of collegiate hockey players. Design and Setting: Collegiate hockey players were selected, because their practices begin in the fall and play is completed in the spring. The teams selected for participation were from the far Northwest and the upper Midwest regions. Subjects: Sixty-eight Division I hockey players volunteered for the study. The three teams from which the subjects were chosen were located above latitude 42°/45' north. Subjects were from the northern latitudes. Measurements: The Seasonal Pattern Assessment Questionnaire was used to screen for seasonality. A sample of the athletes was also examined using the Hamilton Rating Scale for Depression together with the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for Seasonal Pattern Specifier. Results: Thirty-three (51%) were asymptomatic, 7 (11%) met the criteria for seasonal affective disorder, and 25 (39%) hockey players scored in the range that could classify them as candidates for subsyndromal seasonal affective disorder. Conclusions: The prevalence of seasonal affective disorder among our sample approximated the national norm for the northern latitudes. However, the prevalence of subsyndromal seasonal affective disorder in our population was 25% compared to 13% reported nationally. Light therapy has been shown to reverse the effects of the disorders; however, further research needs to be conducted to determine its acceptance and effectiveness by the athletic population. PMID:16558403

  19. A Two-Player Game of Life

    NASA Astrophysics Data System (ADS)

    Levene, Mark; Roussos, George

    We present a new extension of Conway's game of life for two players, which we call ``p2life''. P2life allows one of two types of token, black or white, to inhabit a cell and adds competitive elements into the birth and survival rules of the original game. We solve the mean-field equation for p2life and determine, using simulation, that the asymptotic density of p2life approaches 0.0362.

  20. Linking online gaming and addictive behavior: converging evidence for a general reward deficiency in frequent online gamers.

    PubMed

    Hahn, Tim; Notebaert, Karolien Hilde; Dresler, Thomas; Kowarsch, Linda; Reif, Andreas; Fallgatter, Andreas J

    2014-01-01

    Millions of people regularly play so-called massively multiplayer online role playing games (MMORPGs). Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal, and craving have been described. Based on behavioral, resting state, and task-related neuroimaging data, we test whether frequent players of the MMORPG "World of Warcraft" (WoW) - similar to drug addicts and individuals with an increased risk for addictions - show a generally deficient reward system. In frequent players of the MMORPG "World of Warcraft" (WoW-players) and in a control group of non-gamers we assessed (1) trait sensitivity to reward (SR), (2) BOLD responses during monetary reward processing in the ventral striatum, and (3) ventral-striatal resting-state dynamics. We found a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state). On the behavioral level, we found differences in trait SR, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers.

  1. The El Dorado of Handball? Foreign Female Players Stay, while Domestic Players Return from Abroad.

    PubMed

    Bon, Marta; Topič, Mojca Doupona; Šibila, Marko

    2016-04-01

    The main purpose of this research was to study the characteristics of migration in European women's handball based on the Slovenian example and to find the differences between the foreigners coming to Slovenia and the Slovenians transferring to foreign clubs. The research was based on 16 open face-to-face semi-structured interviews (8 Slovenians (age 29.5 ± 6.2 years) and 8 foreigners (age 35.5 ± 8.7 years)). We found out that the most powerful factor in foreigners was the financial one, while within Slovenian players it was their personal desire for progression within their sport, the club's reputation and poor conditions in their previous club. The results confirm that when making a decision on transfer, all players had the support of family and friends, while the clubs of foreign players were not as supportive. Most interviewees considered their careers successful and did not regret going abroad. The research indicates that the largest differences discovered between Slovenians and foreigners were that foreign female players chose to stay in the new country (Slovenia), while domestic players returned home after few years playing abroad. In conclusion, the results show that in top-level handball there are important differences between migration models which are based on nationality and also that the migration models change throughout time, which is largely connected with the socioeconomic events in the country of origin or transfer.

  2. The El Dorado of Handball? Foreign Female Players Stay, while Domestic Players Return from Abroad

    PubMed Central

    Topič, Mojca Doupona; Šibila, Marko

    2016-01-01

    Abstract The main purpose of this research was to study the characteristics of migration in European women’s handball based on the Slovenian example and to find the differences between the foreigners coming to Slovenia and the Slovenians transferring to foreign clubs. The research was based on 16 open face-to-face semi-structured interviews (8 Slovenians (age 29.5 ± 6.2 years) and 8 foreigners (age 35.5 ± 8.7 years)). We found out that the most powerful factor in foreigners was the financial one, while within Slovenian players it was their personal desire for progression within their sport, the club’s reputation and poor conditions in their previous club. The results confirm that when making a decision on transfer, all players had the support of family and friends, while the clubs of foreign players were not as supportive. Most interviewees considered their careers successful and did not regret going abroad. The research indicates that the largest differences discovered between Slovenians and foreigners were that foreign female players chose to stay in the new country (Slovenia), while domestic players returned home after few years playing abroad. In conclusion, the results show that in top-level handball there are important differences between migration models which are based on nationality and also that the migration models change throughout time, which is largely connected with the socioeconomic events in the country of origin or transfer. PMID:28149349

  3. Are squash players protecting their eyes?

    PubMed Central

    Eime, R; Finch, C; Sherman, C; Garnham, A

    2002-01-01

    Methods: A survey of 303 players (aged ≥18 years) was conducted at three squash venues in Melbourne, Australia over a three week period in June 2000 to obtain information about protective eyewear use. Results: Of 303 participants the response rate was 98.1%; 66.1% were males, with a mean age of 40.5 years. The majority (68.4%) had played squash for 10 years or more. Although 18.8% of players reported using protective eyewear, only 8.9% reported wearing approved eyewear. Both age group (p<0.05) and years of squash experience (p<0.01) were significantly associated with any eyewear use. The two main influences were personal experience of eye injuries (50.0%) and knowledge of eye injury risk (33.9%). A commonly reported barrier was restriction of vision (34.2%). Conclusion: These findings demonstrate a low prevalence of voluntary use of appropriate protective eyewear. Future prevention strategies incorporating education campaigns should focus on increasing players' knowledge of risks. The barriers to use and misconceptions about which types of eyewear is most protective need to be addressed as a priority. PMID:12226124

  4. Effects of plyometric training on soccer players

    PubMed Central

    Wang, Ying-Chun; Zhang, Na

    2016-01-01

    Plyometric training (PT) is a technique used to increase strength and explosiveness. It consists of physical exercises in which muscles exert maximum force at short intervals to increase dynamic performances. In such a training, muscles undergo a rapid elongation followed by an immediate shortening (stretch-shortening contraction), utilizing the elastic energy stored during the stretching phase. There is consensus on the fact that when used, PT contributes to improvement in vertical jump performance, acceleration, leg strength, muscular power, increase of joint awareness and overall sport-specific skills. Consequently, PT which was primarily used by martial artists, sprinters and high jumpers to improve performances has gained in popularity and has been used by athletes in all types of sports. However, although PT has been shown to increase performance variables in many sports, little scientific information is currently available to determine whether PT actually enhances skill performance in soccer players, considering that soccer is an extremely demanding sport. Soccer players require dynamic muscular performance for fighting at all levels of training status, including rapid movements such as acceleration and deceleration of the body, change of direction, vertical and horizontal jumps, endurance, speed as well as power for kicking and tackling. In this review we discussed the effects of PT on soccer players by considering gender and age categories. PMID:27446242

  5. Hip and Groin Injuries in Baseball Players.

    PubMed

    Mlynarek, Ryan A; Coleman, Struan H

    2018-03-01

    To discuss the clinical significance of the most common hip and groin injuries in baseball players, as well as an algorithmic approach to diagnosis and treatment of these injuries. (a) Limitations in throwing velocity, pitch control, and bat swing speed may be secondary to decreased mobility and strength within the proximal kinetic chain, which must harness power from the lower extremities and core. (b) Approximately 5.5% of all baseball injuries per year involve the hip/groin and may lead to a significant amount of time spent on the disabled list. Injuries involving the hip and groin are relatively common in baseball players. Our knowledge of the mechanics of overhead throwing continues to evolve, as does our understanding of the contribution of power from the lower extremities and core. It is paramount that the team physician be able to accurately diagnose and treat injuries involving the hip/groin, as they may lead to significant disability and inability to return to elite levels of play. This review focuses on hip- and groin-related injuries in the baseball player, including femoroacetabular impingement, core muscle injury, and osteitis pubis.

  6. Resting ECG findings in elite football players.

    PubMed

    Bohm, Philipp; Ditzel, Roman; Ditzel, Heribert; Urhausen, Axel; Meyer, Tim

    2013-01-01

    The purpose of the study was to evaluate ECG abnormalities in a large sample of elite football players. Data from 566 elite male football players (57 of them of African origin) above 16 years of age were screened retrospectively (age: 20.9 ± 5.3 years; BMI: 22.9 ± 1.7 kg · m(-2), training history: 13.8 ± 4.7 years). The resting ECGs were analysed and classified according to the most current ECG categorisation of the European Society of Cardiology (ESC) (2010) and a classification of Pelliccia et al. (2000) in order to assess the impact of the new ESC-approach. According to the classification of Pelliccia, 52.5% showed mildly abnormal ECG patterns and 12% were classified as distinctly abnormal ECG patterns. According to the classification of the ESC, 33.7% showed 'uncommon ECG patterns'. Short-QT interval was the most frequent ECG pattern in this group (41.9%), followed by a shortened PR-interval (19.9%). When assessed with a QTc cut-off-point of 340 ms (instead of 360 ms), only 22.2% would have had 'uncommon ECG patterns'. Resting ECG changes amongst elite football players are common. Adjustment of the ESC criteria by adapting proposed time limits for the ECG (e.g. QTc, PR) should further reduce the rate of false-positive results.

  7. Dude Looks like a Lady: Gender Swapping in an Online Game

    NASA Astrophysics Data System (ADS)

    Huh, Searle; Williams, Dmitri

    After reviewing the literature on online identity construction and developing a set of theory-based hypotheses, this chapter employs a novel combination of survey data and game-generated behavioral logs to examine gender swapping in EverQuest II. Gender swapping is defined as a difference between the gender reported by the player in the survey from the gender of the player's main character in the game. Motivations for play were measured using Yee's condensed MMO motivations scale, and behavioral logs supplied four main measures of gender-stereotypical in-game behaviors. Contrary to expectations, gender swapping was less common among female players, and swapping was rather rare in general. Homosexual players were more likely to change their online gender than straight players. Performance and socialization motivations for play did not differ significantly between swappers and nonswappers. Men who play female characters were not more likely to engage in stereotypically female acts than men who play male characters; however, women who played male characters did display a degree of hyper-masculine behavior. Some of these findings suggest that there may be less of the identity exploration or challenging of gender norms than some had expected, but the female population of players may be bimodal, composed of stereotypically female and male-leaning subgroups.

  8. The Relationship Between Online Video Game Involvement and Gaming-Related Friendships Among Emotionally Sensitive Individuals

    PubMed Central

    Domahidi, Emese; Quandt, Thorsten

    2014-01-01

    Abstract Some researchers believe that online gaming spaces can be socially accommodating environments for socially inhibited individuals, such as the socially inept, socially anxious, or shy. While previous research has examined, and found, significant links between these populations and online video game play, it remains unknown to what extent these spaces are contributing to tangible social benefits for the socially inhibited. The current study addresses this question by evaluating the link between gaming-related friendships and shyness, as quantified by emotional sensitivity. Drawing from a representative sample of German game players, the results indicate that emotionally sensitive players are using online gaming spaces differently from their less emotionally sensitive counterparts and reporting tangible differences in their in-game friendship networks. This suggests that online games hold the potential to be socially advantageous for shy individuals by allowing them to overcome their traditional social difficulties and generate new friendships as well as strengthen old ones. PMID:24660878

  9. The relationship between online video game involvement and gaming-related friendships among emotionally sensitive individuals.

    PubMed

    Kowert, Rachel; Domahidi, Emese; Quandt, Thorsten

    2014-07-01

    Some researchers believe that online gaming spaces can be socially accommodating environments for socially inhibited individuals, such as the socially inept, socially anxious, or shy. While previous research has examined, and found, significant links between these populations and online video game play, it remains unknown to what extent these spaces are contributing to tangible social benefits for the socially inhibited. The current study addresses this question by evaluating the link between gaming-related friendships and shyness, as quantified by emotional sensitivity. Drawing from a representative sample of German game players, the results indicate that emotionally sensitive players are using online gaming spaces differently from their less emotionally sensitive counterparts and reporting tangible differences in their in-game friendship networks. This suggests that online games hold the potential to be socially advantageous for shy individuals by allowing them to overcome their traditional social difficulties and generate new friendships as well as strengthen old ones.

  10. Clarifying the Links Among Online Gaming, Internet Use, Drinking Motives, and Online Pornography Use.

    PubMed

    Bőthe, Beáta; Tóth-Király, István; Orosz, Gábor

    2015-04-01

    This study was aimed at investigating the links between online gaming and online pornography use by considering gender, problematic Internet use, and different motives for alcohol drinking. University students (n=512; mean age=22.11 years; standard deviation=2.43 years; 64.06 percent women) filled in the Cyber Pornography Use Inventory, Hungarian version, the Problematic Online Gaming Questionnaire, Hungarian version (POGQ-HU), the Problematic Internet Use Questionnaire, Hungarian version (PIUQ-HU), and the Drinking Motive Questionnaire Revised Short Form, Hungarian version (DMQ-R-HU SF) questionnaires. According to hierarchical multiple regression analyses, the neglect factor of PIUQ-HU, the conformity factor of DMQ-R-HU SF, and the immersion and preoccupation factors of POGQ-HU have a significant predictive value on one's online pornography use, but gender does not. This research shows that independently from the effect of Internet and alcohol use dimensions, immersion and preoccupation factors of online gaming have significant effects on online pornography use. However, preoccupation has a negative effect on pornography use. Players scoring high on this subscale may think about gaming as the only interesting activity that rates higher than even pornography.

  11. Does Group Size Matter for Behavior in Online Trust Dilemmas?

    PubMed

    Artinger, Sabrina; Vulkan, Nir

    2016-01-01

    How does group size influence behavior in online trust dilemmas? We investigate cooperation in groups of 4 to 100 players. While overall levels of cooperation are stable across group sizes, we find significant gender differences: women increase cooperation with group size and cooperate significantly more than men in large groups. These results are robust when controlling for risk aversion, age, and other individual differences. They highlight the importance of studying behavior and gender differences in large groups.

  12. Negotiating Femininities Online

    ERIC Educational Resources Information Center

    Davies, Julia

    2004-01-01

    Much has been written about the potential for online learning (Fryer, 1997; www. ngfl.gov.uk/ngfl/index.html). However this literature typically emphasizes not online learning but online education. In this paper I focus on the potential for online learning, specifically learning about issues surrounding femininity in the presence of online peers,…

  13. Anterior Cruciate Ligament Injuries in Baseball Players.

    PubMed

    Dugas, Jeffrey R; Bedford, Benjamin B; Andrachuk, John S; Scillia, Anthony J; Aune, Kyle T; Cain, E Lyle; Andrews, James R; Fleisig, Glenn S

    2016-11-01

    To determine common mechanisms of anterior cruciate ligament (ACL) injury in baseball players and to quantify the rate of return to play after primary surgical reconstruction and review intermediate clinical outcomes. Surgical injuries involving the ACL in youth, high school, collegiate, and professional baseball players were queried for an 11-year period (2001 to 2011). Over the study period, 42 baseball players were identified who had undergone arthroscopically assisted primary ACL reconstruction by 1 of 3 attending surgeons. Retrospective chart review was performed for all 42 patients to evaluate variables of age, level of competition, position, mechanism of injury, graft choice, and associated meniscal injuries. Twenty-six patients were reached for telephone survey and International Knee Documentation Committee questionnaire and they answered questions about their original injury and playing history. The most common mechanism of injury was fielding, followed by base running. Infielders and outfielders (32% each) were the most commonly injured position, followed by pitchers (29%). Among the 32 players for whom it could be determined, 30 (94%) were able to return to playing baseball at a mean follow-up of 4.2 years (range 1.0 to 9.9 years). The mean International Knee Documentation Committee score was 84.0 (range 63 to 91). Among the 26 patients contacted for telephone interview, no one required revision ACL surgery, but 3 required a subsequent procedure for meniscal tear. Twenty-five patients (96%) denied any episodes of instability in the knee after reconstruction. The overwhelming majority of baseball players that sustain ACL injuries do so while fielding or base running. Outfielders are significantly more likely than infielders to suffer ACL injuries while fielding versus base running. The results with respect to return to play are promising, as nearly all patients were able to return to baseball and none required a revision ACL surgery at a mean follow

  14. Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

    PubMed Central

    Feairheller, Deborah L.; Aichele, Kristin R.; Oakman, Joyann E.; Neal, Michael P.; Cromwell, Christina M.; Lenzo, Jessica M.; Perez, Avery N.; Bye, Naomi L.; Santaniello, Erica L.; Hill, Jessica A.; Evans, Rachel C.; Thiele, Karla A.; Chavis, Lauren N.; Getty, Allyson K.; Wisdo, Tia R.; McClelland, JoAnna M.; Sturgeon, Kathleen; Chlad, Pam

    2016-01-01

    Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5 ± 11.2 mg/dL versus 47.1 ± 14.8 mg/dL), and higher body fat percentage (29.2 ± 7.9% versus 23.2 ± 7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk. PMID:26904291

  15. Decreased shoulder function and pain common in recreational badminton players.

    PubMed

    Fahlström, M; Söderman, K

    2007-06-01

    The aim of this study was to describe the prevalence and consequences of painful conditions in the shoulder region in recreational badminton players. A questionnaire study was performed on 99 players, of whom 57 were also assessed with Constant score. Previous or present pain in the dominant shoulder was reported by 52% of the players. Sixteen percent of the players had on-going shoulder pain associated with badminton play. A majority of these players reported that their training habits were affected by the pain. Total Constant score was lower in the painful shoulders. Furthermore, range of active pain-free shoulder abduction was decreased. However, isometric shoulder strength test showed no differences when compared with pain-free shoulders. Even though the pain caused functional problems, the players were still playing with on-going symptoms. The diagnoses were mostly unknown, although history and clinical tests indicate problems resembling subacromial impingement.

  16. Induced attitude change on online gaming among adolescents: an application of the less-leads-to-more effect.

    PubMed

    Chiou, Wen-Bin

    2008-04-01

    The negative impact of Internet use on adolescents has received much popular attention and has also become a popular research topic. How to induce adolescent players to change their attitudes toward online gaming is one of the most important issues in online gaming addiction. The present study is based on the less-leads-to-more effect of dissonance theory. Experimental research was conducted to examine the effects of rewards and decision freedom on attitude change toward online gaming among adolescents considered at risk for addiction. The results supported predictions based on external justification in dissonance theory. Specifically, fewer rewards produced greater attitude change toward online gaming in the condition of personal freedom of choice after participants exhibited attitude-discrepant behavior. However, the less-leads-to-more effect was not prominent in the condition without personal freedom of choice. Adopting a reward strategy to induce game players to disengage online gaming is discussed.

  17. What do adult squash players think about protective eyewear?

    PubMed Central

    Finch, C.; Vear, P.

    1998-01-01

    OBJECTIVE: To determine the attitudes of adult squash players towards protective eyewear. METHODS: A survey of 197 competition and social squash players from seven squash centres in the outer eastern suburbs of Melbourne, Australia was conducted in September to October 1995. Information about participation in squash, previous injuries, use of protective eyewear, barriers towards eyewear use, and attitudes towards protective eyewear was obtained by a self report questionnaire. RESULTS: Squash is a popular sport in Australia. Of the players surveyed, 6% played in junior competitions, 67% in senior competitions, and 27% were social players. Most had been playing for more than ten years. Some 15% of players had previously suffered an eye injury, most commonly caused by a racquet. Less than 10% of players reported that they wore protective eyewear when they played squash, and 35% of these wore prescriptive lenses which they considered to be protective. The major reason for not wearing protective eyewear was the perception that it was unnecessary. Poor vision and a lack of comfort were also stated as reasons by a significant number of players. More than half (57%) of the respondents agreed that more players should wear protective eyewear, yet only 16% thought it should be compulsory for all players. There was considerable support for protective eyewear use by junior players, however. CONCLUSIONS: The rate of protective eyewear use is low among competition and social squash players in Melbourne. The major areas that need to be addressed are the ignorance of the need for protective eyewear among social and experienced players and the mistaken belief that prescription lenses provide adequate protection on a squash court. 


 PMID:9631225

  18. Exploring Game Experiences and Game Leadership in Massively Multiplayer Online Role-Playing Games

    ERIC Educational Resources Information Center

    Jang, YeiBeech; Ryu, SeoungHo

    2011-01-01

    This study explored the in-game experiences of massively multiplayer online role-playing game (MMORPG) players focusing on game leadership and offline leadership. MMORPGs have enormous potential to provide gameplayers with rich social experiences through various interactions along with social activities such as joining a game community, team play…

  19. MMOGs as Learning Environments: An Ecological Journey into "Quest Atlantis" and "The Sims Online"

    ERIC Educational Resources Information Center

    Young, Michael; Schrader, P. G.; Zheng, Dongping

    2006-01-01

    Michael Young, P. G. Schrader, and Dongping Zheng use the concepts of ecological psychology to examine how massively multiplayer online games (MMOGs) promote specific learning processes in their players. In their analysis they identify and define nine principles of learning that allow such games to have valuable potential as tools for educators:…

  20. A Texas Company Sees Online Learning as Growth Industry in Latin America

    ERIC Educational Resources Information Center

    Campbell, Monica

    2008-01-01

    This article describes the growth of demand in online learning in Latin America and the expansion efforts made by Texas-based Whitney International to fill such niche. Whitney is a newcomer to a growing group of for-profit players that spot unmet demand for higher education in Latin America. Founded in 2005, it began its distance-learning courses…

  1. Head Impact Exposure in Junior and Adult Australian Football Players

    PubMed Central

    King, Doug; Dempsey, Alasdair; Murphy, Myles

    2018-01-01

    This study measured and compared the frequency, magnitude, and distribution of head impacts sustained by junior and adult Australian football players, respectively, and between player positions over a season of games. Twelve junior and twelve adult players were tracked using a skin-mounted impact sensor. Head impact exposure, including frequency, magnitude, and location of impacts, was quantified using previously established methods. Over the collection period, there were no significant differences in the impact frequency between junior and adult players. However, there was a significant increase in the frequency of head impacts for midfielders in both grades once we accounted for player position. A comparable amount of head impacts in both junior and adult players has implications for Australian football regarding player safety and medical coverage as younger players sustained similar impact levels as adult players. The other implication of a higher impact profile within midfielders is that, by targeting education and prevention strategies, a decrease in the incidence of sports-related concussion may result. PMID:29805979

  2. Concussion Knowledge in High School Football Players

    PubMed Central

    Cournoyer, Janie; Tripp, Brady L.

    2014-01-01

    Context: Participating in sports while experiencing symptoms of a concussion can be dangerous. An athlete's lack of knowledge may be one factor influencing his or her decision to report symptoms. In an effort to enhance concussion education among high school athletes, legislation in Florida has attempted to address the issue through parental consent forms. Objective: To survey high school varsity football players to determine their level of knowledge about concussions after the initiation of new concussion-education legislation. Design: Cross-sectional study. Setting: Descriptive survey administered in person during a team meeting. Patients or Other Participants: A total of 334 varsity football players from 11 high schools in Florida. Main Outcome Measure(s): Participants completed a survey and identified the symptoms and consequences of a concussion among distractors. They also indicated whether they had received education about concussions from a parent, formal education, neither, or both. Results: The most correctly identified symptoms were headache (97%), dizziness (93%), and confusion (90%), and the most correctly identified consequence was persistent headache (93%). Participants reported receiving education from their parents (54%) or from a formal source (60%). Twenty-five percent reported never receiving any education regarding concussions. No correlations were found between the method of education and the knowledge of symptoms or consequences of concussion. Conclusions: The high school football players we surveyed did not have appropriate knowledge of the symptoms and consequences of concussions. Nausea or vomiting, neck pain, grogginess, difficulty concentrating, and personality or behavioral changes were often missed by participants, and only a small proportion correctly identified brain hemorrhage, coma, and death as possible consequences of inappropriate care after a concussion. Even with parents or guardians signing a consent form indicating they

  3. Concussion knowledge in high school football players.

    PubMed

    Cournoyer, Janie; Tripp, Brady L

    2014-01-01

    Participating in sports while experiencing symptoms of a concussion can be dangerous. An athlete's lack of knowledge may be one factor influencing his or her decision to report symptoms. In an effort to enhance concussion education among high school athletes, legislation in Florida has attempted to address the issue through parental consent forms. To survey high school varsity football players to determine their level of knowledge about concussions after the initiation of new concussion-education legislation. Cross-sectional study. Descriptive survey administered in person during a team meeting. A total of 334 varsity football players from 11 high schools in Florida. Participants completed a survey and identified the symptoms and consequences of a concussion among distractors. They also indicated whether they had received education about concussions from a parent, formal education, neither, or both. The most correctly identified symptoms were headache (97%), dizziness (93%), and confusion (90%), and the most correctly identified consequence was persistent headache (93%). Participants reported receiving education from their parents (54%) or from a formal source (60%). Twenty-five percent reported never receiving any education regarding concussions. No correlations were found between the method of education and the knowledge of symptoms or consequences of concussion. The high school football players we surveyed did not have appropriate knowledge of the symptoms and consequences of concussions. Nausea or vomiting, neck pain, grogginess, difficulty concentrating, and personality or behavioral changes were often missed by participants, and only a small proportion correctly identified brain hemorrhage, coma, and death as possible consequences of inappropriate care after a concussion. Even with parents or guardians signing a consent form indicating they discussed concussion awareness with their child, 46% of athletes suggested they had not.

  4. The Refractive Error of Professional Baseball Players.

    PubMed

    Laby, Daniel M; Kirschen, David G

    2017-05-01

    High levels of visual acuity are required to hit a baseball effectively. Research has shown that any decrease in vision is likely caused by low-order optical aberrations. This study is designed to validate the SVOne autorefractor, and describe the amount and type, of low-order optical aberrations present in a large cohort of professional baseball players. A retrospective chart review on the 608 Major League Baseball players evaluated during the 2016 Spring Training Season was performed. Results for a subset of players who had both manifest refraction as well as autorefraction were calculated. Subsequently, after determining the accuracy of the autorefraction system in this population, refractive results for the entire population were determined. There was a borderline statistically significant difference in mean spherical refractive error (M) between the manifest refraction and the SVOne auto refraction (-0.273D in the manifest refraction method vs. -0.503D in the SVOne method, P = .06) in the subset of athletes who underwent both tests. Additionally, there was no difference in the J0 or J45 cylindrical component vectors for each method. For the entire eligible population, the SVOne autorefraction system found a mean spherical refractive error (M) of -0.228D, a J0 value of -0.013D, and a J45 value of -0.040D. These data suggest that the SVOne autorefraction system is generally able to measure the refractive error in the baseball population. The system was slightly biased, often reporting more myopia in myopic subjects. Thus, careful evaluation of the refractive status of these athletes coupled with careful subjective refractive correction for those with less than average vision for baseball is strongly suggested.

  5. Making star teams out of star players.

    PubMed

    Mankins, Michael; Bird, Alan; Root, James

    2013-01-01

    Top talent is an invaluable asset: In highly specialized or creative work, for instance, "A" players are likely to be six times as productive as "B" players. So when your company has a crucial strategic project, why not multiply all that firepower and have a team of your best performers tackle it? Yet many companies hesitate to do this, believing that all-star teams don't work: Big egos will get in the way. The stars won't be able to work with one another. They'll drive the team Leader crazy. Mankins, Bird, and Root of Bain & Company believe it's time to set aside that thinking. They have seen all-star teams do extraordinary work. But there is a right way and a wrong way to organize them. Before you can even begin to assemble such a team, you need to have the right talent management practices, so you hire and develop the best people and know what they're capable of. You have to give the team appropriate incentives and leaders and support staffers who are stars in their own right. And projects that are ill-defined or small scale are not for all-star teams. Use them only for critical missions, and make sure their objectives are clear. Even with the right setup, things can still go wrong. The wise executive will take steps to manage egos, prune non-team-players, and prevent average coworkers from feeling completely undervalued. She will also invest a lot of time in choosing the right team Leader and will ask members for lots of feedback to monitor how that leader is doing.

  6. Player preferences among new and old violins.

    PubMed

    Fritz, Claudia; Curtin, Joseph; Poitevineau, Jacques; Morrel-Samuels, Palmer; Tao, Fan-Chia

    2012-01-17

    Most violinists believe that instruments by Stradivari and Guarneri "del Gesu" are tonally superior to other violins--and to new violins in particular. Many mechanical and acoustical factors have been proposed to account for this superiority; however, the fundamental premise of tonal superiority has not yet been properly investigated. Player's judgments about a Stradivari's sound may be biased by the violin's extraordinary monetary value and historical importance, but no studies designed to preclude such biasing factors have yet been published. We asked 21 experienced violinists to compare violins by Stradivari and Guarneri del Gesu with high-quality new instruments. The resulting preferences were based on the violinists' individual experiences of playing the instruments under double-blind conditions in a room with relatively dry acoustics. We found that (i) the most-preferred violin was new; (ii) the least-preferred was by Stradivari; (iii) there was scant correlation between an instrument's age and monetary value and its perceived quality; and (iv) most players seemed unable to tell whether their most-preferred instrument was new or old. These results present a striking challenge to conventional wisdom. Differences in taste among individual players, along with differences in playing qualities among individual instruments, appear more important than any general differences between new and old violins. Rather than searching for the "secret" of Stradivari, future research might best focused on how violinists evaluate instruments, on which specific playing qualities are most important to them, and on how these qualities relate to measurable attributes of the instruments, whether old or new.

  7. The Importance of Vitaminsfor Soccer Players.

    PubMed

    Eskici, Günay

    2015-12-01

    Soccer is one of the most widely played and complex sports in the world, where success depends on technical, tactical and physical skills of the players. Studies to improve performance in soccer have often focused on technique and tactics. However, nutrition is one of the most important factors influencing athletic performance of the players. The duration of matches is long and the training is intense. This leads to increased requirements for energy and nutrients, as well as increased reactive oxygen radicals and hence increased muscle damage. Vitamins are micronutrients that a living organism requires in trace quantities for health. As these assume crucial functions in the body, the performance of the player is negatively affected particularly during long-term deficiency. Beta-carotene, C and E vitamins are antioxidants that protect against oxygen radicals. In case of their deficiency, oxidative stress and muscle fatigue increases. Vitamin D is involved in maintaining mineral balance, and it increases absorption of dietary calcium and phosphorus. In case of vitamin D deficiency, injuries resulting from the musculoskeletal system might increase. B Vitamins (B1, B2, niacin, B6, B12, biotin, folic acid and pantothenic acid) perform duties such as energy production, absorption and transport of iron and blood cell production. Athletes who follow an energy-restricted and imbalanced diet might develop vitamin deficiency. In such a case, supplements can be used as recommended by the doctor/dietician. It is further reported that supplement use by athletes who have an adequate and balanced nutrition does not increase performance.

  8. Does ovulation affect performance in tennis players?

    PubMed

    Otaka, Machiko; Chen, Shu-Man; Zhu, Yong; Tsai, Yung-Shen; Tseng, Ching-Yu; Fogt, Donovan L; Lim, Boon-Hooi; Huang, Chih-Yang; Kuo, Chia-Hua

    2018-01-01

    Scientific data on the performance of collegiate female tennis players during the menstrual phases are scarce. Double-blind, counter-balanced, crossover trials were conducted to examine whether tennis performance was affected during menstruation, with and without dehydroepiandrosterone sulfate (DHEA-S) supplementation. Ten Division 1 collegiate tennis players (aged 18-22 years) were evenly assigned into placebo-supplemented and DHEA-supplemented (25 mg/day) trials. Treatments were exchanged among the participants after a 28-day washout. Tennis serve performance was assessed on the first day of menstrual bleeding (day 0/28) and on days 7, 14 and 21. Mood state was unaltered during the menstrual cycles in both trials. The lowest tennis serve performance score (speed times accuracy) occurred on day 14 (P=0.06 vs day 0; P=0.01 vs day 21) in both placebo and DHEA trials. Decreased performance on day 14 was explained by decreased accuracy (P=0.03 vs day 0/28; P=0.01 vs day 21), but not velocity itself. Isometric hip strength, but not quadriceps strength, was moderately lower on day 14 (P=0.08). Increasing plasma DHEA-S (by ~65%) during the DHEA-supplemented trial had no effects on mood state, sleep quality or tennis serve performance. We have shown that menses does not affect serve performance of collegiate tennis players. However, the observed decrement in the accuracy of serve speed near ovulation warrants further investigation.

  9. [International cooperation on aging: areas and players].

    PubMed

    Sidorenko, A V; Mikhaĭlova, O N

    2014-01-01

    This review article is devoted to the issues of international cooperation on ageing. It aims at describing the basic areas of cooperation and introducing its major players. Within the limited length of a journal article it is hardly possible to offer an exhaustive presentation of all available information; thus the article strives to provide a general orientation within the selected themes. The authors are hopeful that the presented materials will be of interest to the policy oriented researchers, policy makers and professionals working in the field of ageing and related areas such as social security, health and social services etc., as well as to the activists of non-governmental organizations.

  10. Cervical spine injuries in rugby players.

    PubMed Central

    Sovio, O. M.; Van Peteghem, P. K.; Schweigel, J. F.

    1984-01-01

    Nine patients with serious cervical spine injuries that occurred while they were playing rugby were seen in a British Columbia acute spinal cord injury unit during the period 1975-82. All the injuries had occurred during the "scrum" or the "tackle". Two of the patients were rendered permanently quadriplegic, and one patient died. There is a need for a central registry that would record all cervical spine injuries in rugby players as well as for changes in the rules of the game. Images Fig. 1 PMID:6697282

  11. Occupational acroosteolysis in a guitar player.

    PubMed

    Baran, R; Tosti, A

    1993-02-01

    A case of occupational acroosteolysis in a 24-year-old classical guitar player is reported. Nail tenderness was the only manifestation of initial acroosteolysis, which was due to mechanical stress on the fingers. Radiographs showed initial resorption of the 2nd, 3rd and 4th finger of the left hand. The authors review the clinical and radiological features of acroosteolysis. The pathogenesis of acroosteolysis is discussed as well as the different diseases that may cause destructive changes of the distal phalangeal bones.

  12. Relations between basic and specific motor abilities and player quality of young basketball players.

    PubMed

    Marić, Kristijan; Katić, Ratko; Jelicić, Mario

    2013-05-01

    Subjects from 5 first league clubs from Herzegovina were tested with the purpose of determining the relations of basic and specific motor abilities, as well as the effect of specific abilities on player efficiency in young basketball players (cadets). A battery of 12 tests assessing basic motor abilities and 5 specific tests assessing basketball efficiency were used on a sample of 83 basketball players. Two significant canonical correlations, i.e. linear combinations explained the relation between the set of twelve variables of basic motor space and five variables of situational motor abilities. Underlying the first canonical linear combination is the positive effect of the general motor factor, predominantly defined by jumping explosive power, movement speed of the arms, static strength of the arms and coordination, on specific basketball abilities: movement efficiency, the power of the overarm throw, shooting and passing precision, and the skill of handling the ball. The impact of basic motor abilities of precision and balance on specific abilities of passing and shooting precision and ball handling is underlying the second linear combination. The results of regression correlation analysis between the variable set of specific motor abilities and game efficiency have shown that the ability of ball handling has the largest impact on player quality in basketball cadets, followed by shooting precision and passing precision, and the power of the overarm throw.

  13. Prospective Player-Reported Injuries in Female Youth Fast-Pitch Softball Players

    PubMed Central

    Smith, Matthew V.; Davis, Randi; Brophy, Robert H.; Prather, Heidi; Garbutt, Jane; Wright, Rick W.

    2015-01-01

    Background: There is a scarcity of literature evaluating injuries in youth fast-pitch softball players. Purpose: To perform a descriptive analysis of player-reported injuries in youth fast-pitch softball position players and pitchers during a single select-level season. Study Design: Prospective observation cohort study. Level of Evidence: Level 3. Methods: Ninety-eight athletes (48 pitchers, 50 position players) were followed for a single select fast-pitch softball season. Study participants completed web-based surveys every 3 weeks reporting injuries related to participation in fast-pitch softball. Injury was defined as pain causing cessation of participation in the current game or practice that prevents the player’s return to that session or any pain that causes cessation of a player’s customary participation on the day after the day of onset. Results: The median age of the study participants was 14 years (range, 9-18 years). There were 49 reported injuries in 98 athletes. The average age was 13 years for those not injured and 14 years for those who were injured (P < 0.02). There were 31 injuries that were not related to pitching: 19 occurred in position players and 12 occurred in pitchers; 70% of these injuries were to the lower extremity. The proportion of injuries not related to pitching was significantly greater than the proportion of injuries related to pitching (P < 0.02). Eighteen injuries among the 48 pitchers (38%) were directly attributed to pitching. Among the 18 pitching injuries, 11 (61%) involved the shoulder. The majority (78%) of injuries related to pitching occurred in the first 6 weeks of the season. Conclusion: There was a high incidence of injury in this prospective cohort of youth select-level fast-pitch softball players. Better off-season and preseason conditioning may be a key factor for reducing pitching injuries. Clinical Relevance: Recognition of injury patterns in fast-pitch softball players is critical to developing strategies to

  14. Strength Asymmetry of the Shoulders in Elite Volleyball Players

    PubMed Central

    Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

    2014-01-01

    Context: Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. Objective: To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Design: Descriptive laboratory study. Patients or Other Participants: A sample of 183 volleyball players (99 men, 84 women). Main Outcome Measure(s): We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Results: Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. Conclusions: In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male

  15. Strength asymmetry of the shoulders in elite volleyball players.

    PubMed

    Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

    2014-01-01

    Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Descriptive laboratory study. A sample of 183 volleyball players (99 men, 84 women). We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk

  16. Match analysis and player characteristics in rugby sevens.

    PubMed

    Ross, Alex; Gill, Nicholas; Cronin, John

    2014-03-01

    Rugby sevens is a contact sport contested by two teams of seven players who compete over two 7-min halves, most frequently played in a tournament style. The IRB Sevens World Series is thought of as the preeminent rugby sevens competition in the world and has grown in competitiveness from its inception in 2000. The decision to include rugby sevens in the 2016 Olympics is likely to increase the global profile and participation in the game. Many rugby sevens players concurrently compete in 15-a-side rugby union as backs and loose forwards; however, a continued increase in the popularity of rugby sevens will likely see the emergence of the specialist rugby sevens player. Often thought of as the abbreviated version of rugby union, rugby sevens is played under nearly identical laws and on the same field dimensions as the 15-man code. However, research has shown the movement demands of rugby sevens and rugby union are dissimilar, with rugby sevens players spending a larger proportion of the game running at high intensity (≥ 5 m s(-1)). Given the dissimilarity in match demands in conjunction with differences in the competition structure between the codes, it appears the considerable depth of literature specific to performance in rugby union may be of little value for the preparation of rugby sevens players. Investigations of the physical characteristics of rugby sevens players show backs are lighter and shorter than forwards, while players across all positions possess a lean body composition. International rugby sevens players have similar speed characteristics to rugby union backs across distances of 10-30 m; however, rugby sevens players appear to have superior intermittent aerobic endurance. Despite being of likely importance, little is known of the strength and power characteristics of rugby sevens players. Research into the speed and aerobic endurance characteristics of rugby sevens players has not distinguished between backs and forwards and, as such, it is unclear

  17. Badminton injuries in youth competitive players.

    PubMed

    Goh, S L; Mokhtar, A H; Mohamad Ali, M R

    2013-02-01

    The aim of the study was to examine sports injury pattern and establish cost of injuries in relation to training of 58 competitive badminton players in a Malaysian National Sports School. This one-year prospective observational study recruited all the 13-16 year old students after obtaining informed consent from their appointed guardian. All participants were requested to report any injuries, which were pain or disabilities that occur within the study period (September 1, 2008 to August 31, 2009) either during training or competition. Injured students were to seek treatment from the researcher(s) who made weekly visits and they were then followed up accordingly until they return to full training. Details and progress of the injuries were documented during each visit. Sixty-three injuries were recorded. Soft tissue sprains/strains were the commonest injury (64%). About one third of the injuries occurred in the lower limb especially the knees and was followed by back injuries; 38% of the injuries did not require training modification, half of these injuries resumed training within one week. Upon full training, half of them were still symptomatic. Injury risk was 57%; injury rate was 0.9 injuries/ player/1000 training hours. Badminton injuries mostly involved the lower limb and almost all overuse injuries occurred in the lower limb. However, badminton injuries as a whole were predominantly sprains and strains, and not overuse in nature as widely believed.

  18. A physiological evaluation of professional soccer players.

    PubMed

    Raven, P B; Gettman, L R; Pollock, M L; Cooper, K H

    1976-12-01

    The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs.

  19. Online Help Systems

    DTIC Science & Technology

    1989-09-07

    online materials (and the concomitant increase in the cost for hardcopy materials) will make online delivery the marketing choice. In sum, medium of...involved in programming, marketing , human factors research, training, and business management. Job Titles of Online Help Designers Job Title...of Company Senior Research Librarian Advisory Information Developer Research Staff Assistant Marketing Manager Manager of Online Documentation Table

  20. Online Organic Chemistry

    ERIC Educational Resources Information Center

    Janowicz, Philip A.

    2010-01-01

    This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

  1. University Student Online Plagiarism

    ERIC Educational Resources Information Center

    Wang, Yu-mei

    2008-01-01

    This article reports a study investigating university student online plagiarism. The following questions are investigated: (a) What is the incidence of student online plagiarism? (b) What are student perceptions regarding online plagiarism? (c) Are there any differences in terms of student perceptions of online plagiarism and print plagiarism? (d)…

  2. Facilitating Successful Online Discussions

    ERIC Educational Resources Information Center

    Woods, Kathryn; Bliss, Kadi

    2016-01-01

    As online course offerings continue to evolve, researchers have examined many strategies for improving the online learning experience for both the instructor and the student. Asynchronous, online discussions are one of the most common components of online courses. This article provides information about the best practices for facilitating…

  3. Men's harassment behavior in online video games: Personality traits and game factors.

    PubMed

    Tang, Wai Yen; Fox, Jesse

    2016-11-01

    Online video games afford co-play and social interaction, often anonymous, among players from around the world. As predicted by the social identity model of deindividuation effects, undesirable behavior is not uncommon in online gaming environments, and online harassment has become a pervasive issue in the gaming community. In this study, we sought to determine what personality traits and game-related variables predicted two types of online aggression in video games: general harassment (e.g., skill-based taunting, insulting others' intelligence) and sexual harassment (e.g., sexist comments, rape threats). Men who play online video games (N = 425) participated in an anonymous online survey. Social dominance orientation and hostile sexism predicted higher levels of both sexual harassment and general harassment in online games. Game involvement and hours of weekly gameplay were additional predictors of general harassment. We discuss implications of online social aggression and online sexual harassment for online gaming. We also apply our findings to the broader understanding of online harassment, cyberaggression, cyberbullying, and other forms of online hostility in computer-mediated communication contexts. Aggr. Behav. 42:513-521, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Return to Play and Player Performance After Anterior Cruciate Ligament Injury in Elite Australian Rules Football Players

    PubMed Central

    Liptak, Matthew G.; Angel, Kevin R.

    2017-01-01

    Background: Australian Rules football is a highly aerobic and anaerobic game that at times requires players to perform cutting or pivoting maneuvers, potentially exposing them to anterior cruciate ligament (ACL) injury. At present, there are limited data available addressing the impact of ACL injury on return to play and preinjury form after ACL reconstruction. Purpose: To determine the prevalence of ACL injury and the incidence of further ACL injury, and to consider player return to play and return to preinjury form after ACL reconstruction. It was hypothesized that elite-level Australian Football League (AFL) players do not return to preinjury form until, at minimum, 2 years after returning to play. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was undertaken on a cohort of elite AFL players who injured their ACL between 1990 and 2000. Return to play after ACL reconstruction was determined by the mean number of ball disposals, or release of the ball by the hand or foot, at 1, 2, and 3 years after return to play and compared with preinjury form. Associations between player and injury characteristics, method of reconstruction, and outcomes (return to play, preinjury form, and further ACL injury) were examined. Results: During the included seasons, a total of 2723 AFL players were listed. Of these, 131 (4.8%) sustained an ACL injury, with 115 players eligible for inclusion. Of 115 players, 26% did not return to elite competition, while 28% of those who did return experienced further ACL injury. The adjusted mean number of disposals (± standard error of the mean) was significantly lower at 1 year (12.21 ± 0.63; P = .003), 2 years (12.09 ± 0.65; P = .008), and 3 years (11.78 ± 0.77; P = .01) after return to play compared with preinjury (14.23 ± 0.67). On average, players did not return to preinjury form by 3 years (P < .01). Players aged 30 years or older were less likely to return to play compared with younger players (P

  5. Macronutrient Intakes of Male Rugby Union Players: A Review.

    PubMed

    Black, Katherine E; Black, Alistair D; Baker, Dane F

    2018-02-27

    Rugby is a worldwide intermittent team sport, players tend to be heavier than the majority of similar team sport athletes on whom the dietary guidelines have been developed. Therefore, the aim of the current review was to describe the intakes of rugby union players. Article databases were searched up to February 2017 and were included if they were published in English and reporting dietary intakes of male rugby union players. Of the research articles found energy intakes were lower than four of the five studies which reported intakes and expenditure, which would suggest the players were losing weight which is somewhat supported by the decreases in skinfolds seen during pre-season. However, it should also be noted that there are errors in both the measurement of energy intakes and expenditure. Carbohydrate intakes ranged from 2.6 to 6.5 g·kg -1 ·d -1 , which is lower than the current relative to body mass recommendations however, this would not be classed as a low carbohydrate diet. The consistently low intakes of carbohydrate suggest that these intake levels maybe sufficient for performance, given the players greater body mass or there are errors in the measurements. However, there is currently no evidence for the carbohydrate needs of rugby union players in terms of performance. The lower intakes than expenditure would suggest the players were losing weight. Previous research in rugby union players lose body fat during pre-season training.

  6. Analysis of Bridge Player Profiles According to Their Intelligence Areas

    ERIC Educational Resources Information Center

    Bilir, Fatma Pervin; Sirin, Yeliz

    2017-01-01

    The aim of this study is to figure out profiles of bridge players and analyzing them according to their intelligence areas. The sample of the study is consist of 100 volunteers out of 200 bridge players who have attended "Çukurova open double bridge championship" in Adana, Turkey at February 2016. Data have been collected via…

  7. Little League Baseball and Players' Self-Esteem.

    ERIC Educational Resources Information Center

    Hawkins, Donna B.; Gruber, Joseph J.

    1982-01-01

    The effect of a season of little league baseball on the self-esteem of 94 pre-adolescent players was investigated. The Coopersmith Self-esteem Inventory and a newly devised Baseball-Self scale were administered. Significant improvements in players' total Self-esteem, Home-Parents and School-Academic scores were found. (Author/PN)

  8. [Muscular trunk stability in professional and amateur volleyball players].

    PubMed

    Miltner, O; Siebert, C; Tschaepe, R; Maus, U; Kieffer, O

    2010-03-01

    The aim of this study was to analyse the efficiency of muscular activity in the trunk stabilisation of professional volleyball players compared to a group of amateur hobby players. The results were compared amongst the groups as well as with a reference group consisting of asymptomatic individuals. The question to be answered was whether or not professional volleyball players possess a characteristic strength profile in their trunk musculature and if differences exist with regard to the individuals' competitive playing level. In this comparative study 12 professional volleyball players (German Bundesliga) and 18 non-professional volleyball players were analysed with regard to their isometric strength profile in all three planes. The reference group was provided by the Proxomed company, which had previously analysed healthy untrained individuals (n = 1045) of various age groups. A sports-specific profile for the musculature of volleyball players revealed a significant reduction in the flexion and rotation strength as well as a well-developed lateral flexion strength (highly significant when compared to the reference group). With reference to the level played, better strength values in flexion and lateral flexion were found among the professional athletes. Professional volleyball players present with a characteristic trunk musculature strength profile. A detailed analysis of the muscle strength of the spine as part of a sports medicine work-up could prove helpful in preventing injuries and overuse problems in professional and hobby volleyball players.

  9. Investigating the Nutritional and Recovery Habits of Tennis Players

    PubMed Central

    2018-01-01

    In this study, the nutritional and recovery habits of tennis players pre-, during, and post-match-play were investigated. Seventy tennis players completed a bespoke nutrition and recovery habits questionnaire, with questions related to the following areas: match preparation, intra-match nutritional habits, situation dependent variables, and post-match nutrition and recovery. On match day-1, the consumption of balanced meals consisting of carbohydrate (CHO), fat and protein, with some micronutrient considerations were reported by 51% of players. On match-days, CHOs were prioritised prior to match-play with CHO dominant meals consumed by the majority of players. During matches, all players adopted a nutritional strategy, with water (94%), banana(s) (86%) and sports drinks (50%) commonly used. Carbohydrate rich nutritional aids, including sports drinks (80%) and energy gels (26%) were utilised more readily during long matches (>2 h). The day after match-play, 39% of players reported the consumption of “nothing specific”. Multiple post-match recovery strategies were adopted by 80% of players, with foam rolling (77%), ice baths (40%), protein shake intake (37%) and hot baths (26%) most used. Findings indicate highly variable eating and recovery habits in tennis players pre-, during and post-match-play, with scope for improved practices. PMID:29614035

  10. Investigating the Nutritional and Recovery Habits of Tennis Players.

    PubMed

    Fleming, James A; Naughton, Robert J; Harper, Liam D

    2018-04-03

    In this study, the nutritional and recovery habits of tennis players pre-, during, and post-match-play were investigated. Seventy tennis players completed a bespoke nutrition and recovery habits questionnaire, with questions related to the following areas: match preparation, intra-match nutritional habits, situation dependent variables, and post-match nutrition and recovery. On match day-1, the consumption of balanced meals consisting of carbohydrate (CHO), fat and protein, with some micronutrient considerations were reported by 51% of players. On match-days, CHOs were prioritised prior to match-play with CHO dominant meals consumed by the majority of players. During matches, all players adopted a nutritional strategy, with water (94%), banana(s) (86%) and sports drinks (50%) commonly used. Carbohydrate rich nutritional aids, including sports drinks (80%) and energy gels (26%) were utilised more readily during long matches (>2 h). The day after match-play, 39% of players reported the consumption of "nothing specific". Multiple post-match recovery strategies were adopted by 80% of players, with foam rolling (77%), ice baths (40%), protein shake intake (37%) and hot baths (26%) most used. Findings indicate highly variable eating and recovery habits in tennis players pre-, during and post-match-play, with scope for improved practices.

  11. Gender Differences in Coping among Elite Table Tennis Players

    ERIC Educational Resources Information Center

    Kirimoglu, Huseyin

    2011-01-01

    The current study aims to investigate the explanatory power of social support and coping in relation to a competitive sport event between male and female table tennis players. 246 university students table tennis players (120 men and 126 women) from different region and part of Turkey were invited to participate in a survey study included the…

  12. N-Player Stochastic Differential Games. [control theory

    NASA Technical Reports Server (NTRS)

    Varaiya, P.

    1974-01-01

    Conditions are described which guarantee that the control strategies adopted by N players constitute an efficient solution, an equilibrium, or a core solution. The system dynamics are described by an Ito equation, and all players have perfect information. It was found that when the set of instantaneous joint costs and velocity vectors is convex, the conditions are necessary.

  13. Differences in Soccer Kick Kinematics between Blind Players and Controls

    ERIC Educational Resources Information Center

    Giagazoglou, Paraskevi; Katis, Athanasios; Kellis, Eleftherios; Natsikas, Christos

    2011-01-01

    The purpose of the current study was to examine the kinematic differences during instep soccer kicks between players who were blind and sighted controls. Eleven male soccer players who were blind and nine male sighted performed instep kicks under static and dynamic conditions. The results indicated significantly higher (p less than 0.05) ball…

  14. The Mental Skills Training of University Soccer Players

    ERIC Educational Resources Information Center

    Sadeghi, Hassan; Omar-Fauzee, Mohd-Sofian; Jamalis, Marjohan; Ab-Latif, Rozita; Cheric, Majid Chahrdah

    2010-01-01

    The purpose of this study is to identify the kind of mental skills training needed most by the university soccer players. Eight male university football players (aged 25 to 36) from one large university in Kuala Lumpur agreed to participate in this study. On average, they have 10 years of playing experience. All of them have signed the informed…

  15. Relative risk for concussions in young female soccer players.

    PubMed

    Strand, Sarah; Lechuga, David; Zachariah, Thomas; Beaulieu, Kathryn

    2015-01-01

    The objective of this study was to determine the relative risk and reported symptoms of concussions in 11- to 13-year-old, female soccer players. For this, a survey to compare the reported incidence of concussion in age-matched female soccer players to nonsoccer players was performed. The survey included 342 girls between the ages of 11 and 13: 195 were involved in an organized soccer team and 147 were not involved in organized soccer but were allowed to participate in any other sport or activity. A total of 94 of the 195 soccer players, or 48%, reported at least one symptom consistent with a concussion. The most prevalent symptom for these girls was headache (84%). A total of 34 of the 147 nonsoccer players, or 23%, reported at least one symptom consistent with a concussion in the previous six months. These results determined that the relative risk of probable concussions among 11- to 13-year-old, female soccer players is 2.09 (p < .001, α = .05, CI = 95%). This demonstrates that the relative risk of probable concussions in young female soccer players is significantly higher than in a control group of nonsoccer players of the same sex and age.

  16. Groin pain and soccer players: male versus female occurrence.

    PubMed

    Karlsson, M K; Dahan, R; Magnusson, H; Nyquist, F; Rosengren, B E

    2014-08-01

    Groin pain is common in soccer players. Comparison of results from different studies, especially between genders, is difficult as studies use different definitions and data collection procedures. Therefore we conducted a study of both male and female soccer players enabling direct gender comparison. The study enrolled 479 male soccer players aged 25 years (17-43) (mean with range) and 144 female soccer players aged 23 years (16-47), who answered a mailed questionnaire that included specific questions on groin pain and sports history. Data are presented as proportions (%) or as mean with 95% confidence intervals (95% CI). Groin pain was experienced by 55% of male soccer players and 28% of female soccer players, resulting in an odds ratio (OR) of 2.9 (95% CI 1.9, 4.5). Groin pain occurred more often in the preseason, than during the rest of the season in both male and female players (both P<0.001). Playing position in the team or playing league did not seem to influence the risk of suffering groin pain. In soccer players, male gender and preseasonal training appear to be risk factors for developing groin pain.

  17. Labor Market Structure and Salary Determination among Professional Basketball Players.

    ERIC Educational Resources Information Center

    Wallace, Michael

    1988-01-01

    The author investigates the labor market structure and determinants of salaries for professional basketball players. An expanded version of the resource perspective is used. A three-tiered model of labor market segmentation is revealed for professional basketball players, but other variables also are important in salary determination. (Author/CH)

  18. Crowdsourcing malaria parasite quantification: an online game for analyzing images of infected thick blood smears.

    PubMed

    Luengo-Oroz, Miguel Angel; Arranz, Asier; Frean, John

    2012-11-29

    There are 600,000 new malaria cases daily worldwide. The gold standard for estimating the parasite burden and the corresponding severity of the disease consists in manually counting the number of parasites in blood smears through a microscope, a process that can take more than 20 minutes of an expert microscopist's time. This research tests the feasibility of a crowdsourced approach to malaria image analysis. In particular, we investigated whether anonymous volunteers with no prior experience would be able to count malaria parasites in digitized images of thick blood smears by playing a Web-based game. The experimental system consisted of a Web-based game where online volunteers were tasked with detecting parasites in digitized blood sample images coupled with a decision algorithm that combined the analyses from several players to produce an improved collective detection outcome. Data were collected through the MalariaSpot website. Random images of thick blood films containing Plasmodium falciparum at medium to low parasitemias, acquired by conventional optical microscopy, were presented to players. In the game, players had to find and tag as many parasites as possible in 1 minute. In the event that players found all the parasites present in the image, they were presented with a new image. In order to combine the choices of different players into a single crowd decision, we implemented an image processing pipeline and a quorum algorithm that judged a parasite tagged when a group of players agreed on its position. Over 1 month, anonymous players from 95 countries played more than 12,000 games and generated a database of more than 270,000 clicks on the test images. Results revealed that combining 22 games from nonexpert players achieved a parasite counting accuracy higher than 99%. This performance could be obtained also by combining 13 games from players trained for 1 minute. Exhaustive computations measured the parasite counting accuracy for all players as a

  19. The Online Bingo Boom in the UK: A Qualitative Examination of Its Appeal.

    PubMed

    Stead, Martine; Dobbie, Fiona; Angus, Kathryn; Purves, Richard I; Reith, Gerda; Macdonald, Laura

    2016-01-01

    Online bingo has seen significant growth in recent years. This study sought to increase understanding of this growth by exploring the appeal of online bingo. Our aim was to examine the content of ten online bingo websites in the UK and analyse a qualitative secondary dataset of 12 female bingo players to investigate the appeal of online bingo. Using two distinct data sources allowed us to assess how the key messages online websites are trying to convey compare with actual players' motivation to play bingo. Our analysis of bingo websites found a common theme where websites were easy to navigate and structured to present a light-hearted, fun, reassuring, social image of gambling. In addition, the design decisions reflected in the bingo sites had the effect of positioning online bingo as a benign, child-like, homely, women-friendly, social activity. Comparison of the website content with our participants' reasons to play bingo showed congruence between the strategies used by the bingo websites and the motivations of bingo players themselves and the benefits which they seek; suggesting that bingo websites strive to replicate and update the sociability of traditional bingo halls. Online bingo differs from traditional forms of bingo in its ability to be played anywhere and at any time, and its capacity to offer a deeply immersive experience. The potential for this type of online immersion in gambling to lead to harm is only just being investigated and further research is required to understand how the industry is regulated, as well as the effects of online bingo on individual gambling 'careers.'

  20. Appeal of playing online First Person Shooter Games.

    PubMed

    Jansz, Jeroen; Tanis, Martin

    2007-02-01

    First Person Shooter Games (FPSG) such as Counter Strike are often the subject of public concern. Surprisingly, there is no published research available about playing these games. We conducted an exploratory Internet survey (n 5 751) in order to gather information about who the players of online first person shooters are, and why they spend time on playing this particular kind of video game. The results of our survey on the one hand confirmed the stereotype of the gamer as it is often presented in popular media: the players of online FPS were indeed almost exclusively young men (mean age about 18 years) who spend a lot of their leisure time on gaming (about 2.6 h per day). We also found that the most committed gamers, that is, the ones who were members of a (semi)professional clan, scored highest on motives with respect to competition, and challenge in comparison with members of amateur clans and online gamers who had not joined a clan. On the other hand, our results cast doubt on the accuracy of the stereotype. This study showed clearly that online FPSG are not played in isolation. More than 80% of our respondents were member of a clan. Also, the regression analysis showed that the social interaction motive was the strongest predictor of the time actually spend on gaming.

  1. Female Chess Players Outperform Expectations When Playing Men.

    PubMed

    Stafford, Tom

    2018-03-01

    Stereotype threat has been offered as a potential explanation of differential performance between men and women in some cognitive domains. Questions remain about the reliability and generality of the phenomenon. Previous studies have found that stereotype threat is activated in female chess players when they are matched against male players. I used data from over 5.5 million games of international tournament chess and found no evidence of a stereotype-threat effect. In fact, female players outperform expectations when playing men. Further analysis showed no influence of degree of challenge, player age, nor prevalence of female role models in national chess leagues on differences in performance when women play men versus when they play women. Though this analysis contradicts one specific mechanism of influence of gender stereotypes, the persistent differences between male and female players suggest that systematic factors do exist and remain to be uncovered.

  2. Evaluating and treating neurobehavioral symptoms in professional American football players

    PubMed Central

    Possin, Katherine L.; Hess, Christopher P.; Huang, Eric J.; Grinberg, Lea T.; Nolan, Amber L.; Cohn-Sheehy, Brendan I.; Ghosh, Pia M.; Lanata, Serggio; Merrilees, Jennifer; Kramer, Joel H.; Berger, Mitchel S.; Miller, Bruce L.; Yaffe, Kristine; Rabinovici, Gil D.

    2015-01-01

    Summary In the aftermath of multiple high-profile cases of chronic traumatic encephalopathy (CTE) in professional American football players, physicians in clinical practice are likely to face an increasing number of retired football players seeking evaluation for chronic neurobehavioral symptoms. Guidelines for the evaluation and treatment of these patients are sparse. Clinical criteria for a diagnosis of CTE are under development. The contribution of CTE vs other neuropathologies to neurobehavioral symptoms in these players remains unclear. Here we describe the experience of our academic memory clinic in evaluating and treating a series of 14 self-referred symptomatic players. Our aim is to raise awareness in the neurology community regarding the different clinical phenotypes, idiosyncratic but potentially treatable symptoms, and the spectrum of underlying neuropathologies in these players. PMID:26336629

  3. Escapism among players of MMORPGs--conceptual clarification, its relation to mental health factors, and development of a new measure.

    PubMed

    Hagström, David; Kaldo, Viktor

    2014-01-01

    Previous studies show that the concept of escapism needs to be clarified and that its relation to problematic online gaming and other factors needs further examination. This study uses well-established, basic learning theory to clarify the concept of escapism, and examines its relation to problematic gaming, psychological distress, and satisfaction with life among players of massively multiplayer online role-playing games (MMORPGs). MMORPG players (n=201) answered an online questionnaire where these factors were measured and correlated with a previously developed scale on motivation to play (MTPI), including extra items to cover positive and negative aspects of escapism. Factor analysis and construct validation show that positive aspects of escapism are theoretically and empirically unstable and that escapism is best clarified as purely "negative escapism," corresponding to playing being negatively reinforced as a way of avoiding everyday hassles and distress. Negative escapism had a stronger relationship to symptoms of Internet addiction, psychological distress, and life satisfaction than other variables and other more positive motivations to play. Future studies should use the revised subscale for escapism (in the MTPI-R) presented in the present study, for example when screening for Internet addiction.

  4. Analyzing Online Behaviors, Roles, and Learning Communities via Online Discussions

    ERIC Educational Resources Information Center

    Yeh, Yu-Chu

    2010-01-01

    Online learning communities are an important means of sharing and creating knowledge. Online behaviors and online roles can reveal how online learning communities function. However, no study has elucidated the relationships among online behaviors, online roles, and online learning communities. In this study, 32 preservice teachers participated in…

  5. Effect of Concussion on Performance of National Football League Players.

    PubMed

    Reams, Nicole; Hayward, Rodney A; Kutcher, Jeffrey S; Burke, James F

    2017-09-01

    Lingering neurologic injury after concussion may expose athletes to increased risk if return to play is premature. The authors explored whether on-field performance after concussion is a marker of lingering neurologic injury. Retrospective cohort study on 1882 skill-position players who played in the National Football League (NFL) during 2007-2010. Players with concussion based on the weekly injury report were compared with players with other head and neck injuries (controls) on measures of on-field performance using Football Outsiders' calculation of defense-adjusted yards above replacement (DYAR), a measure of a player's contribution controlling for game context. Changes in performance, relative to a player's baseline level of performance, were estimated before and after injury using fixed-effects models. The study included 140 concussed players and 57 controls. Players with concussion performed no better or worse than their baseline on return to play. However, a decline in DYAR relative to their prior performance was noted 2 wk and 1 wk before appearing on the injury report. Concussed players performed slightly better than controls in situations where they returned to play the same week as appearing on the injury report. On return, concussed NFL players performed at their baseline level of performance, suggesting that players have recovered from concussion. Decline in performance noted 2 wk and 1 wk before appearing on the injury report may suggest that concussion diagnosis was delayed or that concussion can be a multihit phenomenon. Athletic performance may be a novel tool for assessing concussion injury and recovery.

  6. Influence of players' physique on rugby football injuries.

    PubMed Central

    Lee, A J; Myers, J L; Garraway, W M

    1997-01-01

    OBJECTIVES: To determine whether there is an association between a player's physique and injuries incurred while playing rugby football. METHODS: A cohort study was carried out involving all senior rugby clubs in the Scottish Borders during the 1993-1994 rugby season. Somatotype estimates were determined for 1152 (95%) of the 1216 eligible players. Body mass index (BMI), chest to waist ratio, and the ponderal index (PI) were used to classify players' physique as endomorphic (obese), mesomorphic (muscular), and ectomorphic (linear). RESULTS: A strong association was found between physique and age (chi 2 test: chi 2 = 317.2, df = 10, P < 0.0001). More younger players were ectomorphs. Older players were more often endomorphic. The physiques of forwards and backs were significantly different (chi 2 test: chi 2 = 58.6, df = 2, P < 0.0001), with forwards being of a heavier build than three-quarters, even after adjustment for age. Endomorphic players were more likely than ectomorphs to be injured in a match after adjustment for age (age-adjusted mean BMI for players who were injured in a match was 25.4 compared with 24.6 for players who were not injured in a match, P < 0.0001; adjusted chest to waist ratio means were 1.136 and 1.125 respectively, P = 0.0307; adjusted PI means were 0.414 and 0.417 respectively, P = 0.0056). Increased risk of injury may occur when players play out of position, since one fifth of all injuries occurred in this circumstance. CONCLUSIONS: Further research needs to be conducted using a more objective method of measuring somatotype on a further cohort of players so that the risk of injury for different body types can be examined more closely and related to other potential confounding factors. The level of increased risk for individuals playing out of their usual playing position needs to be established with a greater degree of certainty. PMID:9192128

  7. Anthropometric and performance comparisons in professional baseball players.

    PubMed

    Hoffman, Jay R; Vazquez, Jose; Pichardo, Napoleon; Tenenbaum, Gershon

    2009-11-01

    This study compared anthropometric and performance variables in professional baseball players and examined the relationship between these variables and baseball-specific performance (i.e., home runs, total bases, slugging percentage, and stolen bases). During a 2-year period, 343 professional baseball players were assessed for height, weight, body composition, grip strength, vertical jump power, 10-yard sprint speed, and agility. Subject population consisted of players on the rosters of one of the minor league affiliates (Rookie, A, AA, AAA) or major league team (MLB). All testing occurred at the beginning of spring training. Players in Rookie and A were significantly (p < 0.05) leaner than players in MLB and AAA. These same players had significantly lower lean body mass than seen in MLB, AAA, and AA players. Greater grip strength (p < 0.05) was seen in MLB and AAA than in Rookie and A. Players in MLB were also faster (p < 0.05) than players in AA, A, and Rookie. Vertical jump power measures were greater (p < 0.05) in MLB than AA, A, and Rookie. Regression analysis revealed that performance measures accounted for 25-31% of the variance in baseball-specific power performance. Anthropometric measures failed to add any additional explanation to the variance in these baseball-specific performance variables. Results indicated that both anthropometric and performance variables differed between players of different levels of competition in professional baseball. Agility, speed, and lower-body power appeared to provide the greatest predictive power of baseball-specific performance.

  8. Australian Football League concussion guidelines: what do community players think?

    PubMed

    White, Peta E; Donaldson, Alex; Sullivan, S John; Newton, Joshua; Finch, Caroline F

    2016-01-01

    Preventing concussion in sport is a global challenge. To assess community-level adult male Australian Football players' views on following the Australian Football League's (AFL) concussion guidelines. 3 focus groups, each comprising 6 players from 1 regional league, were conducted until saturation of issues raised. Discussions followed a semistructured script and were audio-recorded and transcribed verbatim. Thematic analysis was conducted by 2 coders independently. Identified advantages of the guidelines included highlighting the seriousness of concussion; changing the culture around playing with concussion and shifting return-to-play decision responsibility from players to others. Disadvantages included players being removed from play unnecessarily; removal of players' rights to decide if they are fit to play and players changing their behaviours to avoid being removed from play. Identified facilitators to guideline use included local league enforcement; broad information dissemination and impartial medically trained staff to assess concussion. Identified barriers to guideline use included players' desire to play at all costs; external pressure that encouraged players to return to play prematurely; and inconvenience and cost. Players generally understand that the AFL concussion guidelines protect their long-term welfare. However, their desire to play at all costs and help their team win is a common barrier to reporting concussion and adhering to guidelines. Leagues should take a lead role by mandating and enforcing the use of the guidelines and educating coaches, game day medical providers and players. The return-to-play component of the guidelines is complex and needs further consideration in the context of community sport.

  9. Neurodegenerative causes of death among retired National Football League players.

    PubMed

    Lehman, Everett J; Hein, Misty J; Baron, Sherry L; Gersic, Christine M

    2012-11-06

    To analyze neurodegenerative causes of death, specifically Alzheimer disease (AD), Parkinson disease, and amyotrophic lateral sclerosis (ALS), among a cohort of professional football players. This was a cohort mortality study of 3,439 National Football League players with at least 5 pension-credited playing seasons from 1959 to 1988. Vital status was ascertained through 2007. For analysis purposes, players were placed into 2 strata based on characteristics of position played: nonspeed players (linemen) and speed players (all other positions except punter/kicker). External comparisons with the US population used standardized mortality ratios (SMRs); internal comparisons between speed and nonspeed player positions used standardized rate ratios (SRRs). Overall player mortality compared with that of the US population was reduced (SMR 0.53, 95% confidence interval [CI] 0.48-0.59). Neurodegenerative mortality was increased using both underlying cause of death rate files (SMR 2.83, 95% CI 1.36-5.21) and multiple cause of death (MCOD) rate files (SMR 3.26, 95% CI 1.90-5.22). Of the neurodegenerative causes, results were elevated (using MCOD rates) for both ALS (SMR 4.31, 95% CI 1.73-8.87) and AD (SMR 3.86, 95% CI 1.55-7.95). In internal analysis (using MCOD rates), higher neurodegenerative mortality was observed among players in speed positions compared with players in nonspeed positions (SRR 3.29, 95% CI 0.92-11.7). The neurodegenerative mortality of this cohort is 3 times higher than that of the general US population; that for 2 of the major neurodegenerative subcategories, AD and ALS, is 4 times higher. These results are consistent with recent studies that suggest an increased risk of neurodegenerative disease among football players.

  10. The effect of $1, $5 and $10 stakes in an online dictator game.

    PubMed

    Raihani, Nichola J; Mace, Ruth; Lamba, Shakti

    2013-01-01

    The decision rules underpinning human cooperative behaviour are often investigated under laboratory conditions using monetary incentives. A major concern with this approach is that stake size may bias subjects' decisions. This concern is particularly acute in online studies, where stakes are often far lower than those used in laboratory or field settings. We address this concern by conducting a Dictator Game using Amazon Mechanical Turk. In this two-player game, one player (the dictator) determines the division of an endowment between himself and the other player. We recruited subjects from India and the USA to play an online Dictator Game. Dictators received endowments of $1, $5 or $10. We collected two batches of data over two consecutive years. We found that players from India were less generous when playing with a $10 stake. By contrast, the effect of stake size among players from the USA was very small. This study indicates that the effects of stake size on decision making in economic games may vary across populations.

  11. Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

    PubMed

    Monezi, Lucas Antônio; Magalhães, Thiago Pinguelli; Morato, Márcio Pereira; Mercadante, Luciano Allegretti; Furtado, Otávio Luis Piva da Cunha; Misuta, Milton Shoiti

    2018-03-26

    In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

  12. A Method for Using Player Tracking Data in Basketball to Learn Player Skills and Predict Team Performance.

    PubMed

    Skinner, Brian; Guy, Stephen J

    2015-01-01

    Player tracking data represents a revolutionary new data source for basketball analysis, in which essentially every aspect of a player's performance is tracked and can be analyzed numerically. We suggest a way by which this data set, when coupled with a network-style model of the offense that relates players' skills to the team's success at running different plays, can be used to automatically learn players' skills and predict the performance of untested 5-man lineups in a way that accounts for the interaction between players' respective skill sets. After developing a general analysis procedure, we present as an example a specific implementation of our method using a simplified network model. While player tracking data is not yet available in the public domain, we evaluate our model using simulated data and show that player skills can be accurately inferred by a simple statistical inference scheme. Finally, we use the model to analyze games from the 2011 playoff series between the Memphis Grizzlies and the Oklahoma City Thunder and we show that, even with a very limited data set, the model can consistently describe a player's interactions with a given lineup based only on his performance with a different lineup.

  13. Online gaming in the context of social anxiety.

    PubMed

    Lee, Bianca W; Leeson, Peter R C

    2015-06-01

    In 2014, over 23 million individuals were playing massive multiplayer online role-playing games (MMORPGs). In light of the framework provided by Davis's (2001) cognitive-behavioral model of pathological Internet use, social anxiety, expressions of true self, and perceived in-game and face-to-face social support were examined as predictors of Generalized Problematic Internet Use Scale (GPIUS) scores and hours spent playing MMORPGs per week. Data were collected from adult MMORPG players via an online survey (N = 626). Using structural equation modeling, the hypothesized model was tested on 1 half of the sample (N = 313) and then retested on the other half of the sample. The results indicated that the hypothesized model fit the data well in both samples. Specifically, expressing true self in game, higher levels of social anxiety, larger numbers of in-game social supports, and fewer supportive face-to-face relationships were significant predictors of higher GPIUS scores, and the number of in-game supports was significantly associated with time spent playing. The current study provides clinicians and researchers with a deeper understanding of MMORPG use by being the first to apply, test, and replicate a theory-driven model across 2 samples of MMORPG players. In addition, the present findings suggest that a psychometric measure of MMORPG usage is more indicative of players' psychological and social well-being than is time spent playing these games. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  14. The mediating effect of gaming motivation between psychiatric symptoms and problematic online gaming: an online survey.

    PubMed

    Király, Orsolya; Urbán, Róbert; Griffiths, Mark D; Ágoston, Csilla; Nagygyörgy, Katalin; Kökönyei, Gyöngyi; Demetrovics, Zsolt

    2015-04-07

    <.001) via 2 gaming motives: escape (standardized effect=.139, P<.001) and competition (standardized effect=.046, P<.001). The comparison of the 2 main gamer types showed no significant differences in the model. However, when comparing male and female players it was found that women had (1) slightly higher escape scores (on a 5-point Likert scale: mean 2.28, SD 1.14) than men (mean 1.87, SD 0.97) and (2) a stronger association between the escape motive and problematic online gaming (standardized effect size=.64, P<.001) than men (standardized effect size=.20, P=.001). The results suggest that psychiatric distress is both directly and indirectly (via escape and competition motives) negatively associated with POG. Therefore, the exploration of psychiatric symptoms and gaming motives of POG can be helpful in the preparation of prevention and treatment programs.

  15. Coach/player relationships in tennis.

    PubMed

    Prapavessis, H; Gordon, S

    1991-09-01

    The present study examined the variables that predict coach/athlete compatibility. Compatibility among a sample of 52 elite tennis coach/player dyads was assessed using a sport adapted version of Schutz's (1966) Fundamental Interpersonal Relations Orientation-Behaviour (FIRO-B), a sport adapted version of Fiedler's (1967) Least Preferred Co-worker scale (LPC), and Chelladurai and Saleh's (1980) Leadership Scale for Sport (LSS). Self-ratings of the quality of the interaction were obtained from both coach and athlete. Multiple-regression analyses using self-rating scores as the dependent measure were carried out to determine which variables best predicted the degree of compatibility. The sole inventory that significantly predicted compatibility was the LSS. More specifically, the discrepancy between the athlete's preferences and perceptions on the autocratic dimension was the best predictor. Implications for tennis coaches and recommendations for future research in this area are discussed.

  16. Issues in training the female player

    PubMed Central

    Kirkendall, Donald T

    2007-01-01

    On the surface, the women's game appears to be similar to the men's game. On closer examination, there are subtle differences in the nature of how each gender plays the game, which are evident in the disparity between skills, tactics and fitness. The technical weaknesses of women include the first touch, dribbling, long passing and goal keeping. These skill limitations have dictated specific tactical approaches towards both attack and defence. Specific biological limitations inherent in the female player affect the pace and total work output in the women's game. Although it is unrealistic to expect the women's game to approach the work output of the men's game, specific training of skills and fitness will influence the tactical approach to the game. PMID:17504787

  17. Invisible players: a family systems model.

    PubMed

    Hellstedt, Jon

    2005-10-01

    This article attempts to demonstrate that the family is a key player in the athlete's development and performance, sometimes invisible, but often all too visible. The practice of clinical sport psychology is enriched by a family-based orientation to the assessment and treatment of athletes. Creating a workable family system is a challenge for parents. They have many difficult decisions to make, and are often without support and direction in making those choices. Sport psychiatrists and psychologists can be helpful to parents as well as athletes by using family-based assessments and treatment interventions that provide education, challenge, and support as they negotiate the tasks and transitions in the family life cycle.

  18. Dynamics of internal models in game players

    NASA Astrophysics Data System (ADS)

    Taiji, Makoto; Ikegami, Takashi

    1999-10-01

    A new approach for the study of social games and communications is proposed. Games are simulated between cognitive players who build the opponent’s internal model and decide their next strategy from predictions based on the model. In this paper, internal models are constructed by the recurrent neural network (RNN), and the iterated prisoner’s dilemma game is performed. The RNN allows us to express the internal model in a geometrical shape. The complicated transients of actions are observed before the stable mutually defecting equilibrium is reached. During the transients, the model shape also becomes complicated and often experiences chaotic changes. These new chaotic dynamics of internal models reflect the dynamical and high-dimensional rugged landscape of the internal model space.

  19. Protein requirements in male adolescent soccer players.

    PubMed

    Boisseau, N; Vermorel, M; Rance, M; Duché, P; Patureau-Mirand, P

    2007-05-01

    Few investigations have studied protein metabolism in children and adolescent athletes which makes difficult the assessment of daily recommended dietary protein allowances in this population. The problematic in paediatric competitors is the determination of additional protein needs resulting from intensive physical training. The aim of this investigation was to determine protein requirement in 14-year-old male adolescent soccer players. Healthy male adolescent soccer players (N = 11, 13.8 +/- 0.1 year) participated in a short term repeated nitrogen balance study. Diets were designed to provide proteins at three levels: 1.4, 1.2 and 1.0 g protein per kg body weight (BW). Nutrient and energy intakes were assessed from 4 day food records corresponding to 4 day training periods during 3 weeks. Urine was collected during four consecutive days and analysed for nitrogen. The nitrogen balances were calculated from mean daily protein intake, mean urinary nitrogen excretion and estimated faecal and integumental nitrogen losses. Nitrogen balance increased with both protein intake and energy balance. At energy equilibrium, the daily protein intake needed to balance nitrogen losses was 1.04 g kg(-1) day(-1). This corresponds to an estimated average requirement (EAR) for protein of 1.20 g kg(-1) day(-1) and a recommended daily allowance (RDA) of 1.40 g kg(-1) day(-1) assuming a daily nitrogen deposition of 11 mg kg(-1). The results of the present study suggest that the protein requirements of 14-year-old male athletes are above the RDA for non-active male adolescents.

  20. University Football Players, Postural Stability, and Concussions.

    PubMed

    Graves, Barbara Sue

    2016-02-01

    Concussion in football athletes is certainly more prevalent and has potentially serious outcomes. With current concerns and increasing return-to-play issues, additional assessment focus is needed. Division 1 college football athletes, from 18 to 20.9 years (n = 177; age, 19.7 ± 1.2 years; height, 182.3 ± 4.5 cm; weight, 97.3 ± 10.6 kg), before fall practice, over a period of 3 years, underwent baseline postural stability testing (sensory organization test [SOT], NeuroCom). Individuals, who were diagnosed with a concussion (headache, dizziness, fatigue, confusion, or loss of consciousness) during practice or actual competition (n = 15; age, 18.9 ± 0.9 years; height, 181.8 ± 2.5 cm; weight, 86.6 ± 3.6 kg), underwent serial evaluation after injury and 24 hours after concussion. As soon as the player was considered asymptomatic, the test was completed on the first and 14th day. A control group of noninjured male athletes (n = 15; age, 19.1 ± 0.4 years; height, 178.2 ± 3.2 cm; weight, 78.6 ± 2.1 kg) were tested for the same time frame. This particular study was only one part of the total evaluation conducted for the concussed athlete's return to play. Results indicated that the concussion group had a statistically significant (p = 0.037) change from their baseline SOT score and the control group (p = 0.025). This change remained significant until day 14 of posttesting. These data indicate that the SOT, when available, may be a positive additional assessment of concussed college-aged football players. Professionals, when dealing with concussion in competitive sports, do need to continue to work together, but awareness of SOT assessments may also contribute to the return-to-play decisions.

  1. A physiological evaluation of professional soccer players.

    PubMed Central

    Raven, P. B.; Gettman, L. R.; Pollock, M. L.; Cooper, K. H.

    1976-01-01

    The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs. PMID:1009297

  2. Echocardiographic findings in professional hockey players

    PubMed Central

    Fazel, Poorya; Roberts, Brad J.; Brooks, John

    2009-01-01

    Tissue Doppler imaging was used to evaluate the physiological and morphological response in athletes whose cardiac system must not only adapt to intense cardiovascular demands but also support sudden, transient changes in cardiac output. A total of 45 professional hockey players with a mean age of 24 years underwent a baseline transthoracic echocardiographic protocol after a typical morning workout; 12 healthy age- and gender-matched controls were evaluated as a means of comparison. The athletes in this study possessed larger left ventricular diastolic and systolic dimensions than the control group (5.5 ± 0.4 vs 4.9 ± 0.4 cm and 3.9 ± 0.4 vs 3.3 ± 0.4 cm, P < 0.0001). The increase in athletes' septal and posterior wall thickness was not substantial, nor was there a significant difference in left ventricular ejection fraction. The athletes demonstrated consistently larger left ventricular end-diastolic volume (196 ± 34 vs 136 ± 23 mL, P < 0.001) and end-systolic volume (87 ± 20 vs 57 ± 12 mL, P < 0.0001). They also had lower annular septal and lateral early diastolic and systolic tissue Doppler velocities compared with the control group. Thus, characteristic myocardial changes previously reported in elite athletes were also represented in professional hockey players. The lower left ventricular tissue Doppler velocities was a relatively unique finding and probably a consequence of lower postexertion preload levels compared with controls who were measured at rest. PMID:19633740

  3. Biomotor structures in elite female handball players.

    PubMed

    Katić, Ratko; Cavala, Marijana; Srhoj, Vatromir

    2007-09-01

    In order to identify biomotor structures in elite female handball players, factor structures of morphological characteristics and basic motor abilities of elite female handball players (N = 53) were determined first, followed by determination of relations between the morphological-motor space factors obtained and the set of criterion variables evaluating situation motor abilities in handball. Factor analysis of 14 morphological measures produced three morphological factors, i.e. factor of absolute voluminosity (mesoendomorph), factor of longitudinal skeleton dimensionality, and factor of transverse hand dimensionality. Factor analysis of 15 motor variables yielded five basic motor dimensions, i.e. factor of agility, factor of jumping explosive strength, factor of throwing explosive strength, factor of movement frequency rate, and factor of running explosive strength (sprint). Four significant canonic correlations, i.e. linear combinations, explained the correlation between the set of eight latent variables of the morphological and basic motor space and five variables of situation motoricity. First canonic linear combination is based on the positive effect of the factors of agility/coordination on the ability of fast movement without ball. Second linear combination is based on the effect of jumping explosive strength and transverse hand dimensionality on ball manipulation, throw precision, and speed of movement with ball. Third linear combination is based on the running explosive strength determination by the speed of movement with ball, whereas fourth combination is determined by throwing and jumping explosive strength, and agility on ball pass. The results obtained were consistent with the model of selection in female handball proposed (Srhoj et al., 2006), showing the speed of movement without ball and the ability of ball manipulation to be the predominant specific abilities, as indicated by the first and second linear combination.

  4. Left-handed skeletally mature baseball players have smaller humeral retroversion in the throwing arm than right-handed players.

    PubMed

    Takenaga, Tetsuya; Goto, Hideyuki; Sugimoto, Katsumasa; Tsuchiya, Atsushi; Fukuyoshi, Masaki; Nakagawa, Hiroki; Nozaki, Masahiro; Takeuchi, Satoshi; Otsuka, Takanobu

    2017-12-01

    It is known that the humeral retroversion of baseball players is greater in the throwing arm than in the nonthrowing arm. An investigation measuring dry bone specimens also showed that the right humerus had greater retroversion than the left. Considering these facts, it was hypothesized that humeral retroversion would differ between right- and left-handed players. This study aimed to compare the bilateral humeral retroversion between right- and left-handed skeletally mature baseball players. We investigated 260 (196 right-handed and 64 left-handed) male baseball players who belonged to a college or amateur team. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique (humeral torsion angle [HTA]) as described by previous studies. Analysis of covariance, adjusted for handedness and baseball position, assessed the effect of throwing arm dominance on HTA. In comparison of the throwing arm, HTA was significantly smaller in left-handed (left humerus) than in right-handed (right humerus) players (77° vs. 81°; P < .001). In comparison of the nonthrowing arm, HTA was significantly greater in left-handed (right humerus) than in right-handed (left humerus) players (73° vs. 69°; P < .001). The mean side-to-side difference of HTA was significantly smaller in left-handed than in right-handed players (3° vs. 12°; P < .001). Humeral retroversion of left-handed skeletally mature baseball players was significantly smaller in the throwing arm, greater in the nonthrowing arm, and smaller in side-to-side differences than that of right-handed players. These findings may be key to understanding some of the biomechanical differences between right- and left-handed baseball players. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  5. Excessive and addictive gaming control using counselling agent in online game design

    NASA Astrophysics Data System (ADS)

    Ididi, Italumeh O.; Hassan, Sa'adah; Ghani, Abdul Azim Abd; Ali, Norhayati Mohd

    2017-10-01

    In recent times, online game play has become a food for thought to concerned individuals, researchers and authorities of various countries due to its excessive and addictive usage. Although, various government have taken certain measures such as shutting down internet cafe at certain hours of the day, censoring the most brutal, offensive and aggressive sections of certain games before they are released. Researchers have advised developers on ways of limiting harm on players by suggesting design changes on time limit. Furthermore, researchers have also suggested that online game distributors ought to make available appropriate referral services. The impart of the above are yet to make any remarkable impact on players. In this paper, we have proposed a Counseling Agent model integrating informative and self-appraisal messages in online game design as a control measure. Informative and self-appraisal messaging in games have proven optimistic through making positive impact on player's thoughts and behavior towards gaming. These messages are expected to remind players about the negative impact of excessive and addictive gaming habits, as well as suggesting possible reductive solutions through message streaming.

  6. A Pilot Study of Pokémon Go and Players' Physical Activity.

    PubMed

    Liu, Wei; Ligmann-Zielinska, Arika

    2017-12-01

    Pokémon Go is a mobile game released in 2016 that gained great popularity. The goals of this pilot study were to investigate player's game-related behavior pattern, to evaluate Pokémon Go's impact on players' physical activity (PA) and game enjoyment, and to examine the influence of neighborhood environment on game behavior. Forty-seven valid online surveys were collected. Participants were asked questions from five aspects regarding their (1) game status, (2) demographic background and pre-game physical activity, (3) game enjoyment and socializing motivations, (4) perceived game impact on their post-game physical activity, and (5) neighborhood environment's influence on their choice of game location. We examined the first four aspects through descriptive statistics and t-tests, and we investigated the neighborhood impact using logistic regression. Sixty-four percent of participants felt that Pokémon Go made them exercise more than before, about three more times, 3 additional hours, and 5.6 extra miles of PA in total per week. This impact did not vary by gender or body weight status. However, 78.7% participants started to quit or reduce game time by the time of the survey. We also found that players' choice of playing Pokémon Go in the neighborhood is positively associated with the perceived safety level and the walk score of their neighborhood, but negatively associated with the number of Pokéstops near home. Pokémon Go as a location-based mobile game is a promising tool for promoting PA, but more research is needed to prolong its positive impact.

  7. Symptoms from repeated intentional and unintentional head impact in soccer players

    PubMed Central

    Stewart, Walter F.; Kim, Namhee; Ifrah, Chloe S.; Lipton, Richard B.; Bachrach, Tamar A.; Zimmerman, Molly E.; Kim, Mimi

    2017-01-01

    Objective: To determine the rate and differential contribution of heading vs unintentional head impacts (e.g., head to head, goal post) to CNS symptoms in adult amateur soccer players. Methods: Amateur soccer players completed baseline and serial on-line 2-week recall questionnaires (HeadCount) and reported (1) soccer practice and games, (2) heading and unintentional soccer head trauma, and (3) frequency and severity (mild to very severe) of CNS symptoms. For analysis, CNS symptoms were affirmed if one or more moderate, severe, or very severe episodes were reported in a 2-week period. Repeated measures logistic regression was used to assess if 2-week heading exposure (i.e., 4 quartiles) or unintentional head impacts (i.e., 0, 1, 2+) were associated with CNS symptoms. Results: A total of 222 soccer players (79% male) completed 470 HeadCount questionnaires. Mean (median) heading/2 weeks was 44 (18) for men and 27 (9.5) for women. One or more unintentional head impacts were reported by 37% of men and 43% of women. Heading-related symptoms were reported in 20% (93 out of 470) of the HeadCounts. Heading in the highest quartile was significantly associated with CNS symptoms (odds ratio [OR] 3.17, 95% confidence interval [CI] 1.57–6.37) when controlling for unintentional exposure. Those with 2+ unintentional exposures were at increased risk for CNS symptoms (OR 6.09, 95% CI 3.33–11.17) as were those with a single exposure (OR 2.98, 95% CI 1.69–5.26) when controlling for heading. Conclusions: Intentional (i.e., heading) and unintentional head impacts are each independently associated with moderate to very severe CNS symptoms. PMID:28148633

  8. Nutritional intake in soccer players of different ages.

    PubMed

    Ruiz, Fátima; Irazusta, Amaia; Gil, Susana; Irazusta, Jon; Casis, Luis; Gil, Javier

    2005-03-01

    The purpose of this study was to evaluate the dietary practices of soccer players of different ages. The diets of the members of four soccer teams (mean ages of 14.0, 15.0, 16.6 and 20.9 years, respectively) were examined. Our results show that the caloric intake per kilogram of body mass was significantly higher among the youngest players when compared with the adult players (P < 0.05). The contribution of carbohydrates to total energy intake was lower than that recommended for athletes. This contribution decreased with age from 47.4% of total energy intake for the 14-year-olds to 44.6% for the adult players. No significant differences in protein or total fat intake were detected among the teams examined. Overall, our results show that the nutritional intake of the soccer players was not optimal, and that this intake was poorer among the adult players than among the adolescents. On the basis of our results, we recommended that nutritional education should be given to soccer players at an early age and should continue throughout adolescence, not only with a view to improving performance but also to promoting more healthy dietary practices in the long term.

  9. Split-Step Timing of Professional and Junior Tennis Players

    PubMed Central

    Leskosek, Bojan; Filipcic, Tjasa

    2017-01-01

    Abstract The purpose of the study was to determine the timing of a split-step in three categories of tennis players in four groups of strokes. Subjects were divided into three groups: male and female junior, and male professional tennis players. During two tournaments, all matches were recorded with two fixed video cameras. For every stroke, the timing of the split-step between the opponent’s impact point when hitting the ball and the player’s split-step was measured. A two-way analysis of variance (ANOVA) was used to determine the differences between groups of strokes, players and the interaction Player x Stroke Group. A Tukey post-hoc test was employed to determine specific differences. The results revealed differences between players in detecting the opponent’s movement, stroke and ball flight, which were reflected in different split-step timings. Each tennis player has his/her own timing mechanism which they adapt to various game situations. Response times differ significantly depending on the game situation. On average, they are the lowest in the serve, and then gradually rise from the return of the serve to baseline game, reaching the highest values in specific game situations. Players react faster in the first serve than in the second one and in the return of the serve, the response times are lower after the return of the second serve PMID:28210342

  10. Throwing speed and accuracy in baseball and cricket players.

    PubMed

    Freeston, Jonathan; Rooney, Kieron

    2014-06-01

    Throwing speed and accuracy are both critical to sports performance but cannot be optimized simultaneously. This speed-accuracy trade-off (SATO) is evident across a number of throwing groups but remains poorly understood. The goal was to describe the SATO in baseball and cricket players and determine the speed that optimizes accuracy. 20 grade-level baseball and cricket players performed 10 throws at 80% and 100% of maximal throwing speed (MTS) toward a cricket stump. Baseball players then performed a further 10 throws at 70%, 80%, 90%, and 100% of MTS toward a circular target. Baseball players threw faster with greater accuracy than cricket players at both speeds. Both groups demonstrated a significant SATO as vertical error increased with increases in speed; the trade-off was worse for cricketers than baseball players. Accuracy was optimized at 70% of MTS for baseballers. Throwing athletes should decrease speed when accuracy is critical. Cricket players could adopt baseball-training practices to improve throwing performance.

  11. Tracking of Ball and Players in Beach Volleyball Videos

    PubMed Central

    Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

    2014-01-01

    This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

  12. Nutrition and hydration concerns of the female football player.

    PubMed

    Maughan, Ronald J; Shirreffs, Susan M

    2007-08-01

    There is little information on the nutritional habits of female football players at any level of the game. There is also a shortage of information on the nutrition and hydration strategies that players should adopt. In general, differences in nutritional needs between males and females are smaller than differences between individuals, so that principles developed for male players also apply to women. There is a need to address energy balance and body composition: prolonged energy deficits cannot be sustained without harm to health and performance. Published reports show mean carbohydrate intakes for female players of about 5 g/kg/day, and this seems to be too low to sustain consistent intensive training. The timing of protein intake may be as important as the amounts consumed, provided that the total intake is adequate. Dehydration adversely affects skill and stamina in women as it does in men, so an individualised hydration strategy should be developed. The prevalence of iron deficiency in women generally is high, but it seems to be alarmingly high in female players. All players should adopt dietary habits that ensure adequate iron intake. Football training seems to increase bone mass in the weight-bearing limbs, with positive implications for bone health in later life, but some players may be at risk from inadequate calcium dietary intake.

  13. Linking performance decline to choking: players' perceptions in basketball.

    PubMed

    Fryer, Ashley Marie; Tenenbaum, Gershon; Chow, Graig M

    2018-02-01

    This study was aimed at examining how basketball players view unexpected performance errors in basketball, and under what conditions they perceive them as choking. Fifty-three basketball players were randomly assigned into 2 groups (game half) to evaluate the linkage between performance decline and choking as a function of game-time, score gap and game half. Within each group, players viewed 8 scenario clips, which featured a different player conducting an error, and subsequently rated the extent of performance decline, the instance of choking and the salience of various performance attributions regarding the error. The analysis revealed that choking was most salient in the 2nd half of the game, but an error was perceived as choking more saliently in the beginning of the 2nd half. This trend was also shown for players' perception of performance decline. Players' ratings of the attributions assigned to errors, however, revealed that during the end of the 2nd half, time pressure and lack of concentration were the causes of errors. Overall, the results provide evidence towards a conceptual framework linking performance decline to the perception of choking, and that errors conducted by players are perceived as choking when there is not a salient reason to suggest its occurrence.

  14. Player Load in Elite Netball: Match, Training, and Positional Comparisons.

    PubMed

    Young, Christopher M; Gastin, Paul B; Sanders, Nick; Mackey, Luke; Dwyer, Dan B

    2016-11-01

    The activity profile of competition and training in elite netball has not been comprehensively reported in the literature. To measure and analyze player load in elite netballers during matches and training sessions. The primary research question was, How does player load vary between playing positions in a match and between matches and training sessions? Various measures of player load were recorded in 12 elite professional netballers with a mean ± SD age of 26 ± 4.9 y and height of 183.2 ± 8.7 cm. Player load was assessed using a published method that uses accelerometry. Load was represented as total load in arbitrary units (au), playing intensity (au/min), and relative time spent in each of 4 playing intensity zones (low, low to moderate, moderate, and high). Data from 15 games and up to 17 training sessions were analyzed for each player. Player load in matches for the goal-based positions (goal shooter, goal keeper, and goal defense) tended to be lower than the attacking and wing-based positions (goal attack, wing attack, wing defense, and center). The difference was largely due to the amount of time spent in low-intensity activity. Playing intensity of matches was greater than in training sessions; however, the total time spent in moderate- to high-intensity activities was not practically different. Accelerometry is a valuable method of measuring player load in netball, and the present results provide new information about the activity profile of different playing positions.

  15. Performance Outcomes After Metacarpal Fractures in National Basketball Association Players.

    PubMed

    Guss, Michael S; Begly, John P; Ramme, Austin J; Hinds, Richard M; Karia, Raj J; Capo, John T

    2016-12-01

    Background: The aim was to determine whether players in the National Basketball Association (NBA) who sustain metacarpal fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. Methods: Data for 32 NBA players with metacarpal fractures incurred over 11 seasons (2002-2003 to 2012-2013) were obtained from injury reports, press releases, and player profiles (www.nba.com and www.basketballreference.com). Player age, body mass index (BMI), position, shooting hand, number of years in the league, and treatment (surgical vs nonsurgical) were recorded. Individual season statistics for the 2 seasons immediately prior to injury and the 2 seasons after injury, including player efficiency rating (PER), were obtained. Thirty-two controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. Results: Mean age at the time of injury was 27 years with an average player BMI of 24. Players had a mean 5.6 seasons of NBA experience prior to injury. There was no significant change in PER when preinjury and postinjury performances were compared. Neither injury to their shooting hand nor operative management of the fracture led to a decrease in performance during the 2 seasons after injury. When compared with matched controls, no significant decline in performance in PER the first season and second season after injury was found. Conclusion: NBA players sustaining metacarpal fractures can reasonably expect to return to their preinjury performance levels following appropriate treatment.

  16. Performance Outcomes After Metacarpal Fractures in National Basketball Association Players

    PubMed Central

    Guss, Michael S.; Begly, John P.; Ramme, Austin J.; Hinds, Richard M.; Karia, Raj J.; Capo, John T.

    2016-01-01

    Background: The aim was to determine whether players in the National Basketball Association (NBA) who sustain metacarpal fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. Methods: Data for 32 NBA players with metacarpal fractures incurred over 11 seasons (2002-2003 to 2012-2013) were obtained from injury reports, press releases, and player profiles (www.nba.com and www.basketballreference.com). Player age, body mass index (BMI), position, shooting hand, number of years in the league, and treatment (surgical vs nonsurgical) were recorded. Individual season statistics for the 2 seasons immediately prior to injury and the 2 seasons after injury, including player efficiency rating (PER), were obtained. Thirty-two controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. Results: Mean age at the time of injury was 27 years with an average player BMI of 24. Players had a mean 5.6 seasons of NBA experience prior to injury. There was no significant change in PER when preinjury and postinjury performances were compared. Neither injury to their shooting hand nor operative management of the fracture led to a decrease in performance during the 2 seasons after injury. When compared with matched controls, no significant decline in performance in PER the first season and second season after injury was found. Conclusion: NBA players sustaining metacarpal fractures can reasonably expect to return to their preinjury performance levels following appropriate treatment. PMID:28149209

  17. Somatotype, size and body composition of competitive female volleyball players.

    PubMed

    Malousaris, Grigoris G; Bergeles, Nikolaos K; Barzouka, Karolina G; Bayios, Ioannis A; Nassis, George P; Koskolou, Maria D

    2008-06-01

    The aim of this study was to describe the morphological characteristics of competitive female volleyball players. For this purpose, body weight and height, breadths and girths as well as skinfold thickness at various body sites were assessed in 163 elite female volleyball players (age: 23.8+/-4.7 years, years of playing: 11.5+/-4.2, hours of training per week: 11.9+/-2.9, means+/-S.D.). Seventy-nine of these players were from the A1 division and the rest from the A2 division of the Greek National League. Two-way ANOVA was used to compare the differences in these characteristics between competition level and playing position. Body height ranged from 161cm to 194cm, and the mean value (177.1+/-6.5cm) was not inferior to that of international players of similar calibre. Adiposity of these players (sum of 5 skinfolds: 51.8+/-10.2mm, percent body fat: 23.4+/-2.8) was higher than that reported in other studies in which, however, different methodology was used. Volleyball athletes of this study were mainly balanced endomorphs (3.4-2.7-2.9). The A1 division players were taller and slightly leaner with greater fat-free mass than their A2 counterparts. Significant differences were found among athletes of different playing positions which are interpreted by their varying roles and physical demands during a volleyball game. The volleyball players who play as opposites were the only subgroup of players differing between divisions; the A2 opposites had more body fat than A1 opposites. These data could be added in the international literature related to the anthropometric characteristics of competitive female volleyball players.

  18. Approximate N-Player Nonzero-Sum Game Solution for an Uncertain Continuous Nonlinear System.

    PubMed

    Johnson, Marcus; Kamalapurkar, Rushikesh; Bhasin, Shubhendu; Dixon, Warren E

    2015-08-01

    An approximate online equilibrium solution is developed for an N -player nonzero-sum game subject to continuous-time nonlinear unknown dynamics and an infinite horizon quadratic cost. A novel actor-critic-identifier structure is used, wherein a robust dynamic neural network is used to asymptotically identify the uncertain system with additive disturbances, and a set of critic and actor NNs are used to approximate the value functions and equilibrium policies, respectively. The weight update laws for the actor neural networks (NNs) are generated using a gradient-descent method, and the critic NNs are generated by least square regression, which are both based on the modified Bellman error that is independent of the system dynamics. A Lyapunov-based stability analysis shows that uniformly ultimately bounded tracking is achieved, and a convergence analysis demonstrates that the approximate control policies converge to a neighborhood of the optimal solutions. The actor, critic, and identifier structures are implemented in real time continuously and simultaneously. Simulations on two and three player games illustrate the performance of the developed method.

  19. Management of concussion in the professional football player.

    PubMed

    Pieroth, Elizabeth M; Hanks, Christopher

    2014-01-01

    There is no other sport that has come under greater scrutiny surrounding the incidence and treatment of concussion than football, and there is no other professional sports league that has experienced more intense focus of its handling of concussions than the National Football League (NFL). The NFL has received significant criticism of their management of concussion in players from both the popular press and the medical community. However, those working with active NFL players have changed their assessment and treatment of these injuries as the knowledge of concussions has evolved over time. We review the current approach to the management of concussions in the professional football player. © 2014 S. Karger AG, Basel.

  20. Vitamin D profile in National Football League players.

    PubMed

    Maroon, Joseph C; Mathyssek, Christina M; Bost, Jeffrey W; Amos, Austin; Winkelman, Robert; Yates, Anthony P; Duca, Mark A; Norwig, John A

    2015-05-01

    By maintaining phosphate and calcium homeostasis, vitamin D is critical for bone health and possibly physical performance. Hence, vitamin D is important to athletes. Few studies have investigated vitamin D levels in relation to fractures and performance in athletes, and no published study has included a multiracial sample of professional American football players. To assess vitamin D levels, including the prevalence of vitamin D deficiency/insufficiency, in professional American football players and to evaluate the association of vitamin D levels with race, fracture history, and the ability to obtain a contract position, which may be a marker for athletic performance. Cohort study; Level of evidence, 3. Serum vitamin D levels of 80 professional football players from a single team in the National Football League were obtained during the 2011 off-season (mean age, 26.5±3.7 years; black, n=67 [84%]). These levels were used to compare injury reports from the 2011-2012 and 2012-2013 seasons. Statistical analyses were performed to test if vitamin D levels were related to race, fracture history, and the ability to obtain a contract position. Mean vitamin D level was 27.4±11.7 ng/mL, with significantly lower levels for black players (25.6±11.3 ng/mL) versus white players (37.4±8.6 ng/mL; F 1,78=13.00, P=.001). All athletes who were vitamin D deficient were black. When controlling for number of professional years played, vitamin D levels were significantly lower in players with at least 1 bone fracture when compared with no fractures. Players who were released during the preseason because of either injury or poor performance had significantly lower vitamin D levels than did players who played in the regular season. Black professional football players have a higher rate of vitamin D deficiency than do white players. Furthermore, professional football players with higher vitamin D levels were more likely to obtain a contract position in the National Football League

  1. Thermoregulation, Fluid Balance, and Sweat Losses in American Football Players.

    PubMed

    Davis, Jon K; Baker, Lindsay B; Barnes, Kelly; Ungaro, Corey; Stofan, John

    2016-10-01

    Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited

  2. Increased Diels-Alderase activity through backbone remodeling guided by Foldit players.

    PubMed

    Eiben, Christopher B; Siegel, Justin B; Bale, Jacob B; Cooper, Seth; Khatib, Firas; Shen, Betty W; Players, Foldit; Stoddard, Barry L; Popovic, Zoran; Baker, David

    2012-01-22

    Computational enzyme design holds promise for the production of renewable fuels, drugs and chemicals. De novo enzyme design has generated catalysts for several reactions, but with lower catalytic efficiencies than naturally occurring enzymes. Here we report the use of game-driven crowdsourcing to enhance the activity of a computationally designed enzyme through the functional remodeling of its structure. Players of the online game Foldit were challenged to remodel the backbone of a computationally designed bimolecular Diels-Alderase to enable additional interactions with substrates. Several iterations of design and characterization generated a 24-residue helix-turn-helix motif, including a 13-residue insertion, that increased enzyme activity >18-fold. X-ray crystallography showed that the large insertion adopts a helix-turn-helix structure positioned as in the Foldit model. These results demonstrate that human creativity can extend beyond the macroscopic challenges encountered in everyday life to molecular-scale design problems.

  3. Cognitive Dissonance, Personalized Feedback, and Online Gambling Behavior: An Exploratory Study Using Objective Tracking Data and Subjective Self-Report.

    PubMed

    Auer, Michael; Griffiths, Mark D

    2018-01-01

    Providing personalized feedback about the amount of money that gamblers have actually spent may-in some cases-result in cognitive dissonance due to the mismatch between what gamblers actually spent and what they thought they had spent. In the present study, the participant sample ( N  = 11,829) was drawn from a Norwegian population that had played at least one game for money in the past six months on the Norsk Tipping online gambling website. Players were told that they could retrieve personalized information about the amount of money they had lost over the previous 6-month period. Out of the 11,829 players, 4045 players accessed information about their personal gambling expenditure and were asked whether they thought the amount they lost was (i) more than expected, (ii) about as much as expected, or (iii) less than expected. It was hypothesized that players who claimed that the amount of money lost gambling was more than they had expected were more likely to experience a state of cognitive dissonance and would attempt to reduce their gambling expenditure more than other players who claimed that the amount of money lost was as much as they expected. The overall results contradicted the hypothesis because players without any cognitive dissonance decreased their gambling expenditure more than players experiencing cognitive dissonance. However, a more detailed analysis of the data supported the hypothesis because specific playing patterns of six different types of gambler using a machine-learning tree algorithm explained the paradoxical overall result.

  4. Online driver's license renewal.

    DOT National Transportation Integrated Search

    2015-09-01

    The Kentucky Department of Vehicle Regulation is exploring the possibility of developing and implementing online : drivers license renewal. The objective of this project was to: 1) evaluate online drivers license and REAL ID renewal : programs ...

  5. The Online Underworld.

    ERIC Educational Resources Information Center

    Scrogan, Len

    1988-01-01

    Discusses some of the misuses of telecommunicating using school computers, including online piracy, hacking, phreaking, online crime, and destruction boards. Suggests ways that schools can deal with these problems. (TW)

  6. DOT Online Database

    Science.gov Websites

    site requires that JavaScript is enabled in order to function properly. Online Digital Special Collections Welcome to Online Digital Special Collections of interest to Department of Transportation (DOT

  7. TOXLINE (TOXICOLOGY INFORMATION ONLINE)

    EPA Science Inventory

    TOXLINE? (TOXicology information onLINE) are the National Library of Medicines extensive collection of online bibliographic information covering the pharmacological, biochemical, physiological, and toxicological effects of drugs and other chemicals. TOXLINE and TOXLINE65 together...

  8. Online Data Collection.

    ERIC Educational Resources Information Center

    Topp, Neal W.; Pawloski, Bob

    2002-01-01

    Describes the eventful history of online data collection and presents a review of current literature following by a list of pros and cons to be considered when stepping into online surveying. (Contains 14 references.) (Author/YDS)

  9. The Role of Shoe Design in Ankle Sprain Rates Among Collegiate Basketball Players

    PubMed Central

    Curtis, Claudia K; Laudner, Kevin G; McLoda, Todd A; McCaw, Steven T

    2008-01-01

    Context: Much of the recent focus in shoe design and engineering has been on improving athletic performance. Currently, this improvement has been in the form of “cushioned column systems,” which are spring-like in design and located under the heel of the shoe in place of a conventional heel counter. Concerns have been raised about whether this design alteration has increased the incidence of ankle sprains. Objective: To examine the incidence of lateral ankle sprains in collegiate basketball players with regard to shoe design. Design: Prospective cohort study. Setting: Certified athletic trainers at 1014 National Collegiate Athletic Association (NCAA)-affiliated schools sponsoring basketball during the 2005–2006 regular season were notified of an online questionnaire. Athletic trainers at 22 of the 1014 schools participated. Patients or Other Participants: A total of 230 basketball players (141 males, 89 females; age  =  20.2 ± 1.5 years) from NCAA Division I–III basketball programs sustained lateral ankle sprains. Main Outcome Measure(s): Ankle sprain information and type of shoe worn (cushioned column or noncushioned column) were collected via online survey. The incidence of lateral ankle sprains and type of shoes worn were compared using a chi-square analysis. Results: No difference was noted in ankle sprain incidence between groups (χ2  =  2.44, P  =  .20, relative risk  =  1.47, 95% confidence interval [CI]  =  0.32, 6.86). The incidence of ankle sprains was 1.33 per 1000 exposures in the cushioned column group (95% CI  =  0.62, 3.51) and 1.96 per 1000 exposures in the noncushioned column group (95% CI  =  0.51, 4.22). Conclusions: No increased incidence of ankle sprains was associated with shoe design. PMID:18523571

  10. Number of Players and Relative Pitch Area per Player: Comparing Their Influence on Heart Rate and Physical Demands in Under-12 and Under-13 Football Players.

    PubMed

    Castellano, Julen; Puente, Asier; Echeazarra, Ibon; Usabiaga, Oidui; Casamichana, David

    2016-01-01

    The aim of the present study is to analyse the influence of different large-sided games (LSGs) on the physical and physiological variables in under-12s (U12) and -13s (U13) soccer players. The effects of the combination of different number of players per team, 7, 9, and 11 (P7, P9, and P11, respectively) with three relative pitch areas, 100, 200, and 300 m(2) (A100, A200, and A300, respectively), were analysed in this study. The variables analysed were: 1) global indicator such as total distance (TD); work:rest ratio (W:R); player-load (PL) and maximal speed (Vmax); 2) heart rate (HR) mean and time spent in different intensity zones of HR (<75%, 75-84%, 84-90% and >90%), and; 3) five absolute (<8, 8-13, 13-16 and >16 Km h(-1)) and three relative speed categories (<40%, 40-60% and >60% Vmax). The results support the theory that a change in format (player number and pitch dimensions) affects no similarly in the two players categories. Although it can seem that U13 players are more demanded in this kind of LSG, when the work load is assessed from a relative point of view, great pitch dimensions and/or high number of player per team are involved in the training task to the U12 players. The results of this study could alert to the coaches to avoid some types of LSGs for the U12 players such as: P11 played in A100, A200 or A300, P9 played in A200 or A300 and P7 played in A300 due to that U13>U12 in several physical and physiological variables (W:R, time spent in 84-90%HRmax, distance in 8-13 and 13-16 Km h(-1) and time spent in 40-60%Vmax). These results may help youth soccer coaches to plan the progressive introduction of LSGs so that task demands are adapted to the physiological and physical development of participants.

  11. Number of Players and Relative Pitch Area per Player: Comparing Their Influence on Heart Rate and Physical Demands in Under-12 and Under-13 Football Players

    PubMed Central

    Castellano, Julen; Puente, Asier; Echeazarra, Ibon; Usabiaga, Oidui; Casamichana, David

    2016-01-01

    The aim of the present study is to analyse the influence of different large-sided games (LSGs) on the physical and physiological variables in under-12s (U12) and -13s (U13) soccer players. The effects of the combination of different number of players per team, 7, 9, and 11 (P7, P9, and P11, respectively) with three relative pitch areas, 100, 200, and 300 m2 (A100, A200, and A300, respectively), were analysed in this study. The variables analysed were: 1) global indicator such as total distance (TD); work:rest ratio (W:R); player-load (PL) and maximal speed (Vmax); 2) heart rate (HR) mean and time spent in different intensity zones of HR (<75%, 75–84%, 84–90% and >90%), and; 3) five absolute (<8, 8–13, 13–16 and >16 Km h-1) and three relative speed categories (<40%, 40–60% and >60% Vmax). The results support the theory that a change in format (player number and pitch dimensions) affects no similarly in the two players categories. Although it can seem that U13 players are more demanded in this kind of LSG, when the work load is assessed from a relative point of view, great pitch dimensions and/or high number of player per team are involved in the training task to the U12 players. The results of this study could alert to the coaches to avoid some types of LSGs for the U12 players such as: P11 played in A100, A200 or A300, P9 played in A200 or A300 and P7 played in A300 due to that U13>U12 in several physical and physiological variables (W:R, time spent in 84–90%HRmax, distance in 8–13 and 13–16 Km h-1 and time spent in 40–60%Vmax). These results may help youth soccer coaches to plan the progressive introduction of LSGs so that task demands are adapted to the physiological and physical development of participants. PMID:26752422

  12. Physical Fitness Qualities of Professional Rugby League Football Players: Determination of Positional Differences.

    ERIC Educational Resources Information Center

    Meir, Rudi; Newton, Robert; Curtis, Edgar; Fardell, Matthew; Butler, Benjamin

    2001-01-01

    Australian and English professional rugby players completed various physical fitness performance tests to determine differences when grouping players into three different rugby positional categories. Results found minimal differences in test scores on the basis of players' specific positions on a team, however, when players were grouped according…

  13. Developing Self-Efficacy within Role Players in Collegiate Athletics: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Perchinsky, David A.

    2012-01-01

    The purpose of this study was to examine the differences in the level of self-efficacy between starting players and role players in a college Midwest Division III men's football team. The research questions were: 1) What differences in satisfaction levels, if any, can be found among starting players and role players with coach leadership, social…

  14. Online Training in Australia

    ERIC Educational Resources Information Center

    Kuzic, Joze

    2013-01-01

    On-line training is becoming an interesting phenomenon in Australia and has attracted a lot of interest across many industries and businesses (Chan and Ngai, 2007). The research reported here looks at the use of online training in corporations in Australia. It focuses on two aspects of online training, the factors that "warrant" its…

  15. Assessing Online Learning

    ERIC Educational Resources Information Center

    Comeaux, Patricia, Ed.

    2004-01-01

    Students in traditional as well as online classrooms need more than grades from their instructors--they also need meaningful feedback to help bridge their academic knowledge and skills with their daily lives. With the increasing number of online learning classrooms, the question of how to consistently assess online learning has become increasingly…

  16. Reflectors as Online Extraverts?

    ERIC Educational Resources Information Center

    Downing, Kevin; Chim, Tat Mei

    2004-01-01

    Increasingly, online learning is perceived as an effective method of instruction. Much recent educational research has focused on examining the purposes and situations for which online education is best suited. In this paper, students enrolled in two online courses are compared with their peers enrolled in equivalent classroom-based courses to…

  17. Implementing Online Physical Education

    ERIC Educational Resources Information Center

    Mohnsen, Bonnie

    2012-01-01

    Online physical education, although seemingly an oxymoron, appears to be the wave of the future at least for some students. The purpose of this article is to explore research and options for online learning in physical education and to examine a curriculum, assessment, and instructional model for online learning. The article examines how physical…

  18. Developing Online Doctoral Programmes

    ERIC Educational Resources Information Center

    Chipere, Ngoni

    2015-01-01

    The objectives of the study were to identify best practices in online doctoral programming and to synthesise these practices into a framework for developing online doctoral programmes. The field of online doctoral studies is nascent and presents challenges for conventional forms of literature review. The literature was therefore reviewed using a…

  19. Library Online Systems.

    ERIC Educational Resources Information Center

    Folda, Linda; And Others

    1989-01-01

    Issues related to library online systems are discussed in six articles. Topics covered include staff education through vendor demonstrations, evaluation of online public access catalogs, the impact of integrated online systems on cataloging operations, the merits of smart and dumb barcodes, and points to consider in planning for the next online…

  20. Patterns of Physics Reasoning in Face-to-Face and Online Forum Collaboration around a Digital Game

    ERIC Educational Resources Information Center

    Van Eaton, Grant; Clark, Douglas B.; Smith, Blaine E.

    2015-01-01

    Students playing digital learning games in the classroom rarely play alone, even in digital games that are ostensibly "single-player" games. This study explores the patterns of physics reasoning that emerge in face-to-face and online forum collaboration while students play a physics-focused educational game in their classroom. We…

  1. E-Commerce for Library Promotion and Sustainability: How Library Technicians Can Market Themselves and Their Library's Services Online

    ERIC Educational Resources Information Center

    von Retzlaff, Lothar

    2006-01-01

    As players in the delivery of services and online information, libraries are in the best position to use staff expertise and the technology they have developed to foster community awareness of social, professional and commercial interactions on the internet. Historically, libraries have been progressive institutions, undertaking constant…

  2. Network characteristics for server selection in online games

    NASA Astrophysics Data System (ADS)

    Claypool, Mark

    2008-01-01

    Online gameplay is impacted by the network characteristics of players connected to the same server. Unfortunately, the network characteristics of online game servers are not well-understood, particularly for groups that wish to play together on the same server. As a step towards a remedy, this paper presents analysis of an extensive set of measurements of game servers on the Internet. Over the course of many months, actual Internet game servers were queried simultaneously by twenty-five emulated game clients, with both servers and clients spread out on the Internet. The data provides statistics on the uptime and populations of game servers over a month long period an an in-depth look at the suitability for game servers for multi-player server selection, concentrating on characteristics critical to playability--latency and fairness. Analysis finds most game servers have latencies suitable for third-person and omnipresent games, such as real-time strategy, sports and role-playing games, providing numerous server choices for game players. However, far fewer game servers have the low latencies required for first-person games, such as shooters or race games. In all cases, groups that wish to play together have a greatly reduced set of servers from which to choose because of inherent unfairness in server latencies and server selection is particularly limited as the group size increases. These results hold across different game types and even across different generations of games. The data should be useful for game developers and network researchers that seek to improve game server selection, whether for single or multiple players.

  3. [Doping practices and behaviours among Ivorian soccer players].

    PubMed

    Dah, Cyrille; Bogui, Pascal; Yavo, Jean-Claude; Gourouza, Issa; Ouattara, Soualiho; Keita, Mustapha

    2002-01-01

    We have conducted a survey of doping among soccer players in Côte d'Ivoire with a representative sample of 150 soccer players who filled out an anonymous questionnaire. The aim of this survey was to get a clearer picture of doping in Ivorian soccer in order to suggest preventive actions against doping. The results of this study showed that doping was known by the Ivorian soccer players; about 18.7% admitted to the use of doping substances, 42% recognised that they felt tempted by doping, while 38% knew another soccer player who had already used a doping substance. Government and sports organisations should recognize the importance of education and information in the antidoping campaign and agree on effective preventive as well as repressive strategies.

  4. Soccer players' fitting perception of different upper boot materials.

    PubMed

    Olaso Melis, J C; Priego Quesada, J I; Lucas-Cuevas, A G; González García, J C; Puigcerver Palau, S

    2016-07-01

    The present study assessed the influence of upper boot materials on fitting perception. Twenty players tested three soccer boots only differing in the upper boot material (natural calf leather, natural kangaroo leather and synthetic leather). Players reported fitting perception and preference on specific foot areas using a perceived fitting scale. Ratings were averaged for every foot area. Repeated measures ANOVA was used to analyze the differences between boots. The kangaroo leather boots were perceived tighter and closer to the preferred fitting in general fitting, metatarsals area and instep area. The synthetic leather boots were perceived as the loosest and as the most distant boot from the preferred fitting in medial front area and instep area. In conclusion, the type of upper boot material influences the fitting perception of soccer players. The kangaroo leather was the material whose fitting was perceived closest to the players fitting preference. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  5. Home advantage and player nationality in international club football.

    PubMed

    Poulter, Damian R

    2009-06-01

    The home advantage effect was investigated at a team and player level in Union of European Football Associations (UEFA) Champions League football using in-depth performance and disciplinary variables. Performance analysis revealed that the home team scored more goals, had more shots on and off target, had a greater share of possession, and won more corners than the away team. There was an opposite trend for disciplinary variables, with the home team committing less fouls than the away team, and receiving less yellow and red cards. There were home advantage effects at player level for goals, total shots, shots on target, assists, and yellow cards, as found in the team analysis. In addition, foreign players demonstrated a home advantage effect for goals scored, whereas domestic players scored an equivalent number of goals at home and away venues. Results are discussed in relation to the home advantage literature and wider implications for the sport.

  6. Harsh environments and the evolution of multi-player cooperation.

    PubMed

    De Jaegher, Kris

    2017-02-01

    The game-theoretic model in this paper provides micro-foundations for the effect a harsher environment on the probability of cooperation among multiple players. The harshness of the environment is alternatively measured by the degree of complementarity between the players' cooperative efforts in producing a public good, and by the number of attacks on an existing public good that the players can collectively defend, where it is shown that these two measures of the degree of adversity facing the players operate in a similar fashion. We show that the effect of the degree of adversity on the probability of cooperation is monotonous, and has an opposite sign for smaller and for larger cooperation costs. For intermediate cooperation costs, we show that the effect of a harsher environment on the probability of cooperation is hill-shaped. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Hypoconnectivity and Hyperfrontality in Retired American Football Players

    NASA Astrophysics Data System (ADS)

    Hampshire, Adam; MacDonald, Alex; Owen, Adrian M.

    2013-10-01

    Recent research has raised concerns about the long-term neurological consequences of repetitive concussive and sub-concussive injuries in professional players of American Football. Despite this interest, the neural and psychological status of retired players remains unknown. Here, we evaluated the performances and brain activation patterns of retired National Football League players (NFL alumni) relative to controls using an fMRI-optimised neuropsychological test of executive function. Behaviourally, the NFL alumni showed only modest performance deficits on the executive task. By contrast, they showed pronounced hyperactivation and hypoconnectivity of the dorsolateral frontal and frontopolar cortices. Critically, abnormal frontal-lobe function was correlated with the number of times that NFL alumni reported having been removed from play after head injury and was evident in individual players. These results support the hypothesis that NFL alumni have a heightened probability of developing executive dysfunction and suggest that fMRI provides the most sensitive biomarker of the underlying neural abnormality.

  8. Hypoconnectivity and hyperfrontality in retired American football players.

    PubMed

    Hampshire, Adam; MacDonald, Alex; Owen, Adrian M

    2013-10-17

    Recent research has raised concerns about the long-term neurological consequences of repetitive concussive and sub-concussive injuries in professional players of American Football. Despite this interest, the neural and psychological status of retired players remains unknown. Here, we evaluated the performances and brain activation patterns of retired National Football League players (NFL alumni) relative to controls using an fMRI-optimised neuropsychological test of executive function. Behaviourally, the NFL alumni showed only modest performance deficits on the executive task. By contrast, they showed pronounced hyperactivation and hypoconnectivity of the dorsolateral frontal and frontopolar cortices. Critically, abnormal frontal-lobe function was correlated with the number of times that NFL alumni reported having been removed from play after head injury and was evident in individual players. These results support the hypothesis that NFL alumni have a heightened probability of developing executive dysfunction and suggest that fMRI provides the most sensitive biomarker of the underlying neural abnormality.

  9. [PREVALENCE OF DEHYDRATION BEFORE TRAINING IN PROFESIONAL CHILEAN SOCCER PLAYERS].

    PubMed

    Castro-Sepúlveda, Mauricio; Astudillo, Sebastian; Álvarez, Cristian; Zapata-Lamana, Rafael; Zbinden-Foncea, Hermann; Ramírez-Campillo, Rodrigo; Jorquera, Carlos

    2015-07-01

    there is a lack of studies concerning hydration status before training in professional soccer player. to describe hydration status before regular training practices in professional soccer players. a total of 156 male soccer players (age 25.4 ± 5.2 y) from six professional Chilean clubs were included. No hydration or food intake recommendations were made before experiment, with the aim to assess hydration status under athlete's regular "real" conditions. Body mass, height and urine specific gravity (USG) measurements were performed before training practices. 98% of athletes showed dehydration (between moderate and severe) before regular training practices. dehydration is the most prevalent hydration status in professional Chilean soccer players before training, which may negatively affect athlete's performance and may increase their risk of heat-related injuries. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  10. Incidence of injuries in high school softball and baseball players.

    PubMed

    Shanley, Ellen; Rauh, Mitchell J; Michener, Lori A; Ellenbecker, Todd S

    2011-01-01

    Participation in high school sports has grown 16.1% over the last decade, but few studies have compared the overall injury risks in girls' softball and boys' baseball. To examine the incidence of injury in high school softball and baseball players. Cohort study. Greenville, South Carolina, high schools. Softball and baseball players (n = 247) from 11 high schools. Injury rates, locations, types; initial or subsequent injury; practice or game setting; positions played; seasonal trends. The overall incidence injury rate was 4.5/1000 athlete-exposures (AEs), with more injuries overall in softball players (5.6/1000 AEs) than in baseball players (4.0/1000 AEs). Baseball players had a higher initial injury rate (75.9/1000 AEs) than softball players (66.4/1000 AEs): rate ratio (RR) = 0.88, 95% confidence interval (CI) = 0.4, 1.7. The initial injury rate was higher than the subsequent injury rate for the overall sample (P < .0001) and for softball (P < .0001) and baseball (P < .001) players. For both sports, the injury rate during games (4.6/1000 AEs) was similar to that during practices (4.1/1000 AEs), RR = 1.22, 95% CI = 0.7, 2.2. Softball players were more likely to be injured in a game than were baseball players (RR = 1.92, 95% CI = 0.8, 4.3). Most injuries (77%) were mild (3.5/1000 AEs). The upper extremity accounted for the highest proportion of injuries (63.3%). The incidence of injury for pitchers was 37.3% and for position players was 15.3%. The rate of injury was highest during the first month of the season (7.96/1000 AEs). The incidence of injury was low for both softball and baseball. Most injuries were minor and affected the upper extremity. The injury rates were highest in the first month of the season, so prevention strategies should be focused on minimizing injuries and monitoring players early in the season.

  11. Incidence of Injuries in High School Softball and Baseball Players

    PubMed Central

    Shanley, Ellen; Rauh, Mitchell J.; Michener, Lori A.; Ellenbecker, Todd S.

    2011-01-01

    Context: Participation in high school sports has grown 16.1% over the last decade, but few studies have compared the overall injury risks in girls' softball and boys' baseball. Objective: To examine the incidence of injury in high school softball and baseball players. Design: Cohort study. Setting: Greenville, South Carolina, high schools. Patients or Other Participants: Softball and baseball players (n = 247) from 11 high schools. Main Outcome Measure(s): Injury rates, locations, types; initial or subsequent injury; practice or game setting; positions played; seasonal trends. Results: The overall incidence injury rate was 4.5/1000 athlete-exposures (AEs), with more injuries overall in softball players (5.6/1000 AEs) than in baseball players (4.0/1000 AEs). Baseball players had a higher initial injury rate (75.9/1000 AEs) than softball players (66.4/1000 AEs): rate ratio (RR) = 0.88, 95% confidence interval (CI) = 0.4, 1.7. The initial injury rate was higher than the subsequent injury rate for the overall sample (P < .0001) and for softball (P < .0001) and baseball (P < .001) players. For both sports, the injury rate during games (4.6/1000 AEs) was similar to that during practices (4.1/1000 AEs), RR = 1.22, 95% CI = 0.7, 2.2. Softball players were more likely to be injured in a game than were baseball players (RR = 1.92, 95% CI = 0.8, 4.3). Most injuries (77%) were mild (3.5/1000 AEs). The upper extremity accounted for the highest proportion of injuries (63.3%). The incidence of injury for pitchers was 37.3% and for position players was 15.3%. The rate of injury was highest during the first month of the season (7.96/1000 AEs). Conclusions: The incidence of injury was low for both softball and baseball. Most injuries were minor and affected the upper extremity. The injury rates were highest in the first month of the season, so prevention strategies should be focused on minimizing injuries and monitoring players early in the season. PMID:22488191

  12. Ranking benchmarks of top 100 players in men's professional tennis.

    PubMed

    Reid, Machar; Morris, Craig

    2013-01-01

    In men's professional tennis, players aspire to hold the top ranking position. On the way to the top spot, reaching the top 100 can be seen as a significant career milestone. National Federations undertake extensive efforts to assist their players to reach the top 100. However, objective data considering reasonable ranking yardsticks for top 100 success in men's professional tennis are lacking. Therefore, it is difficult for National Federations and those involved in player development to give empirical programming advice to young players. By taking a closer look at the ranking history of professional male tennis players, this article tries to provide those involved in player development a more objective basis for decision-making. The 100 names, countries, birthdates and ranking histories of the top 100 players listed in the Association of Tennis Professionals (ATP) at 31 December 2009 were recorded from websites in the public domain. Descriptive statistics were reported for the ranking milestones of interest. Results confirmed the merits of the International Tennis Federation's junior tour with 91% of the top 100 professionals earning a junior ranking, the mean peak of which was 94.1, s=148.9. On average, top 100 professionals achieved their best junior rankings and earned their first ATP point at similar ages, suggesting that players compete on both the junior and professional tours during their transition. Once professionally ranked, players took an average 4.5, s=2.1 years to reach the ATP top 100 at the mean age of 21.5, s=2.6 years, which contrasts with the mean current age of the top 100 of 26.8, s=3.2. The best professional rankings of players born in 1982 or earlier were positively related to the ages at which players earned their first ATP point and then entered the top 100, suggesting that the ages associated with these ranking milestones may have some forecasting potential. Future work should focus on the change in top 100 demographics over time as well

  13. Whole-Person Impairment in Younger Retired NFL Players

    PubMed Central

    Domb, Benjamin G.; Carter, Chris; Finch, Nathan A.; Hammarstedt, Jon E.; Dunne, Kevin F.; Stake, Christine E.

    2014-01-01

    Background: Professional American football is a physically demanding, high-impact sport with an elevated risk of injury. Orthopaedic injuries may impose acute, short-term or cumulative consequences throughout a player’s lifetime. Several studies have addressed health and psychosocial concerns of an older, retired population of players in the National Football League (NFL); however, minimal research has examined the orthopaedic toll on younger, retired players. Purpose: This study reports total whole-person impairment (WPI) percentages in a cohort of younger, retired NFL players who presented for disability evaluations based on the use of standardized American Medical Association (AMA) impairment guidelines. Study Design: Case series; Level of evidence, 4. Methods: During the study period of February 2011 to August 2013, 65 younger retired NFL players presented for impairment evaluations. The mean time between retirement and impairment evaluation was 3.1 years (range, 0.3-16.4 years). A complete history and physical examination was performed on all symptomatic joints. A retrospective chart review was conducted on 100% of presenting players to assess orthopaedic burden. Body-part impairment (BPI) percentage for each affected joint was generated. The impairment data for each extremity were then combined with spine impairment data to create WPI percentage. Player demographics, including age, position, and playing time, were also recorded. Results: The average WPI percentage was 37% (range, 19%-53%). Players participating in >30 games (n = 54) had a higher mean WPI percentage (38%) than those playing in <30 games (31%; n = 11) (P = .004). Players competing in >5 seasons (n = 46) were 2.4 times more likely to have a WPI of at least 37% (P = .007). The most common joints players reported as symptomatic were lumbar (n = 63; 97%) and cervical spine (n = 58; 89%). The mean age at evaluation was 33.5 years (range, 27-42 years), and the mean number of seasons played was 7

  14. Linking Online Gaming and Addictive Behavior: Converging Evidence for a General Reward Deficiency in Frequent Online Gamers

    PubMed Central

    Hahn, Tim; Notebaert, Karolien Hilde; Dresler, Thomas; Kowarsch, Linda; Reif, Andreas; Fallgatter, Andreas J.

    2014-01-01

    Millions of people regularly play so-called massively multiplayer online role playing games (MMORPGs). Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal, and craving have been described. Based on behavioral, resting state, and task-related neuroimaging data, we test whether frequent players of the MMORPG “World of Warcraft” (WoW) – similar to drug addicts and individuals with an increased risk for addictions – show a generally deficient reward system. In frequent players of the MMORPG “World of Warcraft” (WoW-players) and in a control group of non-gamers we assessed (1) trait sensitivity to reward (SR), (2) BOLD responses during monetary reward processing in the ventral striatum, and (3) ventral-striatal resting-state dynamics. We found a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state). On the behavioral level, we found differences in trait SR, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers. PMID:25426039

  15. Nutritional Practices of National Female Soccer Players: Analysis and Recommendations

    PubMed Central

    Martin, Louise; Lambeth, Anneliese; Scott, Dawn

    2006-01-01

    The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day-1) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key points Female soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study. Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer players Fluid requirements should be addressed on an individual basis and matched to player requirements. The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV. PMID:24198690

  16. Nutritional practices of national female soccer players: analysis and recommendations.

    PubMed

    Martin, Louise; Lambeth, Anneliese; Scott, Dawn

    2006-01-01

    The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day(-1)) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key pointsFemale soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study.Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer playersFluid requirements should be addressed on an individual basis and matched to player requirements.The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV.

  17. Hip Arthroscopy in High-Level Baseball Players.

    PubMed

    Byrd, J W Thomas; Jones, Kay S

    2015-08-01

    To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a paired-samples t test determined that this mean improvement of 13 points was statistically significant (P < .001). Players returned to baseball after 42 of 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), with 90% regaining the ability to participate at their previous level of competition. There were no complications. Three players (1 bilateral) underwent repeat arthroscopy. This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level IV, therapeutic case series. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  18. An Analysis of Futsal Players' Self-Esteem Levels

    ERIC Educational Resources Information Center

    Kocak, Mehmet

    2015-01-01

    The purpose of this study is to investigate the self-esteem levels of futsal players according to certain variables. The samples of the study constituted 119 females and 96 males; a total of 215 players with an average age of 21.57 ± 2.20 years. The research was carried out with the end of "Rosenberg self-esteem Scale" developed by…

  19. Vulnerability Analysis of the Player Command and Control Protocol

    DTIC Science & Technology

    2012-06-14

    client plug-ins currentl:v only exist for C++, . Java . and Python. Player is designed a.’:i a. client-server architecture in which robots running Player...I 0.. double -1.0272 angular velocity ;.... ~ va t- <ll ~ 38 2D 73 65 * :>, ""’::!’ ell I 0, +’ 00 00 00 01 uint8 t state 1 motor state v .S 2.5

  20. Upper extremity sensorimotor control among collegiate football players.

    PubMed

    Laudner, Kevin G

    2012-03-01

    Injuries stemming from shoulder instability are very common among athletes participating in contact sports, such as football. Previous research has shown that increased laxity negatively affects the function of the sensorimotor system potentially leading to a pathological cycle of shoulder dysfunction. Currently, there are no data detailing such effects among football players. Therefore, the purpose of this study was to examine the differences in upper extremity sensorimotor control among football players compared with that of a control group. Forty-five collegiate football players and 70 male control subjects with no previous experience in contact sports participated. All the subjects had no recent history of upper extremity injury. Each subject performed three 30-second upper extremity balance trials on each arm. The balance trials were conducted in a single-arm push-up position with the test arm in the center of a force platform and the subjects' feet on a labile device. The trials were averaged, and the differences in radial area deviation between groups were analyzed using separate 1-way analyses of variance (p < 0.05). The football players showed significantly more radial area deviation of the dominant (0.41 ± 1.23 cm2, p = 0.02) and nondominant arms (0.47 ± 1.63 cm2, p = 0.03) when compared with the control group. These results suggest that football players may have decreased sensorimotor control of the upper extremity compared with individuals with no contact sport experience. The decreased upper extremity sensorimotor control among the football players may be because of the frequent impacts accumulated during football participation. Football players may benefit from exercises that target the sensorimotor system. These findings may also be beneficial in the evaluation and treatment of various upper extremity injuries among football players.

  1. Physiological characteristics of elite and sub-elite badminton players.

    PubMed

    Ooi, Cheong Hwa; Tan, Albert; Ahmad, Azwari; Kwong, Kien Weng; Sompong, Ruji; Ghazali, Khairul Aswadi Mohd; Liew, Swee Lee; Chai, Wen Jin; Thompson, Martin William

    2009-12-01

    The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.

  2. Prevalence of Os Styloideum in National Hockey League Players

    PubMed Central

    Greditzer, Harry G.; Hutchinson, Ian D.; Geannette, Christian S.; Hotchkiss, Robert N.; Kelly, Bryan T.; Potter, Hollis G.

    2017-01-01

    Background: Os styloideum describes an accessory carpal ossicle between the trapezoid, the capitate, and the second and third metacarpals. Injuries to this tissue have been described as part of the carpal boss syndrome. While the etiology of os styloideum remains uncertain, it may represent a physiologic response to altered loading forces in the wrist, similar to the development of cam-type deformity in the hips of ice hockey players or the Bennett lesion in the shoulders of baseball pitchers. Hypothesis: Professional hockey players will have a higher prevalence of os styloideum compared with the general population. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of 16 professional hockey players from 4 different National Hockey League (NHL) teams who underwent unilateral imaging of the wrist was performed. Seventeen wrists were reviewed for the presence of os styloideum. Results: Thirteen of 16 players (81%) had an os styloideum, representing an increased prevalence compared with the general population. Previous clinical and cadaveric studies estimated a general prevalence of up to 19% (P < 0.001). For the 10 players who had their leading wrist scanned, 9 had an os styloideum (90%). Ten of 11 (91%) players demonstrated a bone marrow edema pattern within the metacarpal and the os styloideum on magnetic resonance imaging. There was no significant association between the presence of an os styloideum and the player’s position, leading wrist, or years in the league. Conclusion: There appears to be an increased prevalence of os styloideum among NHL players, and team physicians should consider this finding while formulating a differential diagnosis for dorsal wrist pain. Clinical Relevance: This study identified NHL players as having an increased prevalence of os styloideum compared with the general population. By doing so, these findings represent an opportunity to enhance our understanding of the etiology, clinical significance

  3. Anthropometric and physiological profiles of sepak takraw players

    PubMed Central

    Jawis, M; Singh, R; Singh, H; Yassin, M; Khanna, G

    2005-01-01

    Objectives: Anthropometric and physiological profiles of national sepak takraw players were determined. Methods: Thirty nine players, specialising in the three playing positions (tekong/server, feeder, and killer/spiker) were divided into three age categories of under 15 (U15), under 18 (U18), and under 23 (U23) years of age. Height, weight, percent body fat (%bf), maximum oxygen consumption (Vo2max), range of motion (ROM), back and leg strength, and heart rate, for the estimation of oxygen consumption during matches, were recorded. Statistical analysis was performed using one way ANOVA for independent measurements and data are presented as mean±standard deviation. Results: The U23 players were significantly taller and heavier with significantly better ROM of the neck, trunk, and ankle joints and back and leg strength than the U15 players. No significant difference was found in %bf between the three age categories. Mean maximum heart rate during exercise was significantly higher in the U15 group when compared to the U18 and U23 groups (p<0.05). Mean Vo2max was similar between the three groups. Estimated oxygen consumption during matches was 69.1%, 68.5%, and 56.4% of Vo2max in the killer, tekong, and the feeder groups, respectively. Conclusions: The mean height, body weight, and cardiopulmonary capacities of the players were within the Malaysian population norms, but were somewhat lower than those of players of other court games from other countries. %bf was also lower in these players. This study provides the much needed anthropometric and physiological data of sepak takraw players for further development of this sport. PMID:16244191

  4. Differences in energy capacities between tennis players and runners.

    PubMed

    Novak, Dario; Vucetić, Vlatko; Zugaj, Sanja

    2013-05-01

    The primary purpose of this study was to determine differences between elite athletes and tennis players in order to provide a clearer picture regarding the energy demands in modern tennis. Forty-eight (48) athletes and 24 tennis players from Croatian national leagues were compared in morphological and physiological parameters of an all-out incremental treadmill test with gas exchange measurements. Tennis players' HRmax (192.96+/-7.75 bpm) shows values that are most different to 400-meters sprinters (200.13+/-6.95 bpm). Maximum running speed of tennis players on the treadmill (vmax) is no different with the speed achieved by sprinters, while there are significant differences among other athletes. Values in running speed at anaerobic threshold (vAnT) show no statistically significant difference with the values for athlete sprinters and 400-m sprinters. Values of RvO2max for tennis players indicate significant similarities with athlete sprinters and 400-m sprinters while the values of RvO2AnT are nearly identical with the values for sprinters and show no statistically significant differences (p<0.05). The results indicate that values achieved by tennis players approximate most different those of the middle and long distance runners. This singles out the possible importance of the anaerobic capacity and the high level of sprint endurance in tennis players. Knowing these characteristics is the basis for planning and implementing training systems that will enable the increase and optimal usage of energy capacities of tennis players in possibly improving sports results.

  5. Nutrition for the Australian Rules football player.

    PubMed

    Ebert, T R

    2000-12-01

    This review summarises past and present nutritional practices of Australian Rules Football players, noting changes that have occurred as the footballers have become more receptive to scientific input. Australian Rules Football is a unique sport, with matches involving intermittent high intensity sprints between periods of jogging and walking and repeated physical contact. Endurance, speed, strength, power and agility are essential physical characteristics. Australian Rules footballers exhibit a wide range of anthropometrical attributes due to the positional requirements of the game. Dietary surveys indicate that footballers of the 1980's consumed a diet similar to that of the general Australian population consisting of 44%, 37.5%, 15% and 3.5% of carbohydrate (CHO), fat, protein and alcohol, respectively. However, as dietitians are becoming an integral part of the support staff of teams there is evidence that nutritional practices conducive to optimal sporting performance are now being followed. Due to the prolonged duration and intermittent high intensity activity pattern of Australian Rules, nutritional supplementation such as fluid and CHO intake during training and competition and creatine intake may be beneficial; however, further research needs to be conducted in the field to determine its importance in Australian Rules Football.

  6. Determinants of feedback retention in soccer players.

    PubMed

    Januário, Nuno; Rosado, António; Mesquita, Isabel; Gallego, José; Aguilar-Parra, José M

    2016-06-01

    This study analyzed soccer players' retention of coaches' feedback during training sessions. We intended to determine if the retention of information was influenced by the athletes' personal characteristic (age, gender and the sports level), the quantity of information included in coach's feedback (the number of ideas and redundancy), athletes' perception of the relevance of the feedback information and athletes' motivation as well as the attention level. The study that was conducted over the course of 18 sessions of soccer practice, involved 12 coaches (8 males, 4 females) and 342 athletes (246 males, 96 females), aged between 10 and 18 years old. All coach and athlete interventions were transposed to a written protocol and submitted to content analysis. Descriptive statistics and multiple linear regression were calculated. The results showed that a substantial part of the information was not retained by the athletes; in 65.5% of cases, athletes experienced difficulty in completely reproducing the ideas of the coaches and, on average, the value of feedback retention was 57.0%. Six variables with a statistically significant value were found: gender, the athletes' sports level, redundancy, the number of transmitted ideas, athletes' perception of the relevance of the feedback information and the athletes' motivation level.

  7. Incidence of tinnitus in mp3 player users.

    PubMed

    Figueiredo, Ricardo Rodrigues; Azevedo, Andreia Aparecida de; Oliveira, Patrícia Mello de; Amorim, Sandro Pereira Vasconcellos; Rios, Artur Guedes; Baptista, Vanderlei

    2011-06-01

    Exposure to loud noise is one of the main causes of tinnitus. To analyze the incidence of tinnitus in mp3 player users and non-users. One hundred subjects aged from 15 to 30 years were enrolled, 54 of them were regular mp3 player users and 46 were not. Patients with continuous tinnitus for at least 6 months completed the Tinnitus Handicap Inventory (THI) and were tested with high frequency audiometry and transient-evoked otoacoustic emissions (TAOE). A cross-sectional cohort study. The incidence of tinnitus in non-users was about 8 %; in mp3 player users it was about 28 %, a statistically significant difference. Hearing thresholds at 8 kHz were significantly higher in tinnitus patients that used mp3 portable players.TAOE were reduced at 2 kHz in the users group. No statistically significant difference was found in the THI scores between the two groups. Tinnitus was more frequent in teenagers and young adults who regularly listen to mp3 music in players. Moreover, the incidence of tinnitus among mp3 player users was associated with higher hearing thresholds at 8 kHz and lower TOAE at 2 kHz.

  8. Role-player expectations regarding the education of nursing research.

    PubMed

    Zeelie, S C; Bornman, J E; Botes, A C

    2003-12-01

    This article reports on role player expectations regarding the education of nursing research. The importance of the role player expectations are two-fold: firstly as a factor in the external environment influencing and guiding the formulation phase of the development of standards and secondly, due to the clear indications of problems regarding nursing research in the nursing profession in literature. The role player expectations were elicited using a qualitative, exploratory and contextual design. The role player population included nurse educators, nurses in managerial, clinical and research positions, students and the medical profession. The data was gathered using the naïve sketches and qualitative data analysis was done using Morse & Field's approach (1996:103-107) in combination with Tesch's data analysis approach as cited by Creswell (1994:154-156). Sixty initial categories were narrowed down to six final categories, which are the research learning programme, personnel, students, departmental policies, funding and support systems. The role player expectations were elicited as part of a research study aiming tot develop a self-evaluation system for quality assurance in nursing research and as such, the role player expectations plays a pivotal role in the development of standards for the self-evaluation system.

  9. Physiological profiles of Hong Kong élite soccer players.

    PubMed Central

    Chin, M K; Lo, Y S; Li, C T; So, C H

    1992-01-01

    Most physiological profiles of élite soccer players originate from Western Europe and North America. Unfortunately, there is a scarcity of descriptive data on the physical characteristics of Asian soccer players. Therefore, the purpose of this study was to evaluate the physiological profiles of élite soccer players in Hong Kong. It was conducted in conjunction with the selection of the Hong Kong team before the 1990 Beijing Asian Games. In all, 24 professional soccer players were selected from a pool of 180 players as subjects for the study. The following means(s.d.) were observed: height 173.4(4.6) cm; weight 67.7(5.0) kg; body fat 7.3(3.0)%; forced vital capacity (FVC) 5.1(0.6) l; maximum oxygen uptake (VO2max) 59.1(4.9) ml kg-1 min-1; anaerobic threshold (AT 80.0(7.2)% of VO2max; alactic power index 13.5(2.4) W kg-1; lactic work index 298(27) J kg-1; peak isokinetic dominant knee extensor and flexor strengths 2.72(0.36) Nm kg-1 and 1.65(0.20) Nm kg-1. On average the physique of Hong Kong soccer players appeared to be smaller and lighter than those found in Europe, which may be one of the key factors that contribute to the lack of success of Hong Kong soccer teams in international competition. PMID:1490221

  10. Injury Pattern in Icelandic Elite Male Handball Players.

    PubMed

    Rafnsson, Elis Thor; Valdimarsson, Örnólfur; Sveinsson, Thorarinn; Árnason, Árni

    2017-10-10

    To examine the incidence, type, location, and severity of injuries in Icelandic elite male handball players and compare across factors like physical characteristics and playing position. Prospective cohort study. The latter part of the preseason and the competitive season of Icelandic male handball. Eleven handball teams (185 players) from the 2 highest divisions in Iceland participated in the study. Six teams (109 players) completed the study. Injuries were recorded by the players under supervision from their team physiotherapists or coaches. Coaches recorded training exposure, and match exposure was obtained from the Icelandic and European Handball Federations. The players directly recorded potential risk factors, such as age, height, weight, previous injuries, and player position. Injury incidence and injury location and number of injury days. Recorded time-loss injuries were 86, of which 53 (62%) were acute and 33 (38%) were due to overuse. The incidence of acute injuries was 15.0 injuries/1000 hours during games and 1.1 injuries/1000 hours during training sessions. No significant difference was found in injury incidence between teams, but number of injury days did differ between teams (P = 0.0006). Acute injuries were most common in knees (26%), ankles (19%), and feet/toes (17%), but overuse injuries occurred in low back/pelvic region (39%), shoulders (21%), and knees (21%). Previous knee injuries were the only potential risk factor found for knee injury. The results indicate a higher rate of overuse injuries in low back/pelvic region and shoulders than in comparable studies.

  11. Efficiently detecting outlying behavior in video-game players.

    PubMed

    Kim, Young Bin; Kang, Shin Jin; Lee, Sang Hyeok; Jung, Jang Young; Kam, Hyeong Ryeol; Lee, Jung; Kim, Young Sun; Lee, Joonsoo; Kim, Chang Hun

    2015-01-01

    In this paper, we propose a method for automatically detecting the times during which game players exhibit specific behavior, such as when players commonly show excitement, concentration, immersion, and surprise. The proposed method detects such outlying behavior based on the game players' characteristics. These characteristics are captured non-invasively in a general game environment. In this paper, cameras were used to analyze observed data such as facial expressions and player movements. Moreover, multimodal data from the game players (i.e., data regarding adjustments to the volume and the use of the keyboard and mouse) was used to analyze high-dimensional game-player data. A support vector machine was used to efficiently detect outlying behaviors. We verified the effectiveness of the proposed method using games from several genres. The recall rate of the outlying behavior pre-identified by industry experts was approximately 70%. The proposed method can also be used for feedback analysis of various interactive content provided in PC environments.

  12. [Eating habits of a group of professional volleyball players].

    PubMed

    Gacek, Maria

    2011-01-01

    The aim of the research was an analysis of the eating habits of professional volleyball players according to their sex and age. The research has been carried out on a group of 210 men players and women players at the age of 13-25, representatives of sports clubs in Ostrołeka, Myślenice, Bydgoszcz and Warszawa. The research has revealed a limited realisation of rational diets by both men and women players. The most common mistakes made by them include a smaller number of meals during the day than recommended (especially among men), taking up training on empty stomach and insufficient frequency of consumption of dairy products, fish, vegetables and fruit. The research has also revealed excessive consumption of sweets, sweet sparkling drinks and fast food (mainly among men). The examined players to some extent only apply regular strategies of rehydration of their organisms. A high percentage of them do not pay attention to supplementation of liquids after an effort or they drink a lot of liquids at one time. The most frequently chosen drinks were mineral water and isotonic drinks. Supplementation was applied by a small percentage of the players, mainly men, who most often chose vitamins, Izostar, creatine, L-carnitine and HMB.

  13. Predictors of individual player match performance in junior Australian football.

    PubMed

    Tangalos, Christie; Robertson, Samuel J; Spittle, Michael; Gastin, Paul B

    2015-10-01

    Player match statistics in junior Australian football (AF) are not well documented, and contributors to success are poorly understood. A clearer understanding of the relationships between fitness and skill in younger players participating at the foundation level of the performance pathway in AF has implications for the development of coaching priorities (eg, physical or technical). To investigate the relationships between indices of fitness (speed, power, and endurance) and skill (coach rating) on player performance (disposals and effective disposals) in junior AF. Junior male AF players (N = 156, 10-15 y old) were recruited from 12 teams of a single amateur recreational AF club located in metropolitan Victoria. All players were tested for fitness (20-m sprint, vertical jump, 20-m shuttle run) and rated by their coach on a 6-point Likert scale for skill (within a team in comparison with their teammates). Player performance was assessed during a single match in which disposals and their effectiveness were coded from a video recording. Coach rating of skill displayed the strongest correlations and, combined with 20-m shuttle test, showed a good ability to predict the number of both disposals and effective disposals. None of the skill or fitness attributes adequately explained the percentage of effective disposals. The influence of team did not meaningfully contribute to the performance of any of the models. Skill development should be considered a high priority by coaches in junior AF.

  14. Early-onset arthritis in retired National Football League players.

    PubMed

    Golightly, Yvonne M; Marshall, Stephen W; Callahan, Leigh F; Guskiewicz, Kevin

    2009-09-01

    Injury has been identified as a potential risk factor for osteoarthritis. However, no previous study has addressed playing-career injuries and subsequent osteoarthritis in a large sample of former athletes. The purpose of this study was to describe the prevalence and determinants of arthritis and osteoarthritis in retired professional football players. Self-reported arthritis prevalence and retrospectively-recalled injury history were examined in a cross-sectional survey of 2,538 retired football players. Football players reported a high incidence of injury from their professional playing days (52.8% reported knee injuries, 74.1% reported ligament/tendon injuries, and 14.2% reported anterior cruciate ligament tears). For those under 60 years, 40.6% of retired NFL players reported arthritis, compared with 11.7% of U.S. males (prevalence ratio = 3.5, 95% CI: 3.3 to 3.7). Within the retired NFL player cohort, osteoarthritis was more prevalent in those with a history of knee injury (prevalence ratio = 1.7, 95% CI: 1.5 to 1.9) and ligament/tendon injury (prevalence ratio = 1.6, 95% CI: 1.4 to 1.9). In males under the age of 60, arthritis is over 3 times more prevalent in retired NFL players than in the general U.S. population. This excess of early-onset arthritis may be due to the high incidence of injury in football.

  15. Physical Performance in Elite Male and Female Team Handball Players.

    PubMed

    Wagner, Herbert; Fuchs, Patrick; Fusco, Andrea; Fuchs, Philip; Bell, W Jeffrey; Duvillard, Serge P

    2018-06-12

    Biological differences between men and women are well known; however, literature-addressing knowledge about the influence of sex to specific and general performance in team handball is almost nonexistent. Consequently, the aim of the study was to assess and compare specific and general physical performance in male and female elite team handball players, to determine if the differences are consequential for general compared to specific physical performance characteristics and the relationship between general and specific physical performance. Twelve male and ten female elite team handball players performed a game based performance test, upper- und lower-body strength and power tests, a sprinting test, and an incremental treadmill-running test. Significant differences (P<.05) between male and female players were found for peak oxygen uptake and total running time during the treadmill test, 30m sprinting time, leg extension strength, trunk and shoulder rotation torque, counter movement jump height as well as offense and defense time, ball velocity and jump height in the game based performance test. An interaction (sex × test) was found for time and oxygen uptake and except shoulder rotation torque and ball velocity in females, we found only a low relationship between specific and general physical performance. The results of the study revealed that male players are heavier, taller, faster, stronger, jump higher and have a better aerobic performance. However, female players performed relatively better in the team handball specific tests compared to the general tests. Our findings also suggest that female players should focus more on strength training.

  16. Online games: a novel approach to explore how partial information influences human random searches

    NASA Astrophysics Data System (ADS)

    Martínez-García, Ricardo; Calabrese, Justin M.; López, Cristóbal

    2017-01-01

    Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories traced on the board. The experimental data are explained by a family of random-walk-based models and probabilistic analytical approximations. If no initial information is given to the players, the search is optimized for cues that cover an intermediate spatial scale. In addition, initial information about the extension of the cues results, in general, in faster searches. Finally, strategies used by informed players turn into non-stationary processes in which the length of e ach displacement evolves to show a well-defined characteristic scale that is not found in non-informed searches.

  17. Online games: a novel approach to explore how partial information influences human random searches.

    PubMed

    Martínez-García, Ricardo; Calabrese, Justin M; López, Cristóbal

    2017-01-06

    Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories traced on the board. The experimental data are explained by a family of random-walk-based models and probabilistic analytical approximations. If no initial information is given to the players, the search is optimized for cues that cover an intermediate spatial scale. In addition, initial information about the extension of the cues results, in general, in faster searches. Finally, strategies used by informed players turn into non-stationary processes in which the length of e ach displacement evolves to show a well-defined characteristic scale that is not found in non-informed searches.

  18. Violent video game players and non-players differ on facial emotion recognition.

    PubMed

    Diaz, Ruth L; Wong, Ulric; Hodgins, David C; Chiu, Carina G; Goghari, Vina M

    2016-01-01

    Violent video game playing has been associated with both positive and negative effects on cognition. We examined whether playing two or more hours of violent video games a day, compared to not playing video games, was associated with a different pattern of recognition of five facial emotions, while controlling for general perceptual and cognitive differences that might also occur. Undergraduate students were categorized as violent video game players (n = 83) or non-gamers (n = 69) and completed a facial recognition task, consisting of an emotion recognition condition and a control condition of gender recognition. Additionally, participants completed questionnaires assessing their video game and media consumption, aggression, and mood. Violent video game players recognized fearful faces both more accurately and quickly and disgusted faces less accurately than non-gamers. Desensitization to violence, constant exposure to fear and anxiety during game playing, and the habituation to unpleasant stimuli, are possible mechanisms that could explain these results. Future research should evaluate the effects of violent video game playing on emotion processing and social cognition more broadly. © 2015 Wiley Periodicals, Inc.

  19. Fitness Profiles of Elite Adolescent Irish Rugby Union Players.

    PubMed

    Wood, Daniel J; Coughlan, Garrett F; Delahunt, Eamonn

    2018-01-01

    Wood, DJ, Coughlan, GF, and Delahunt, E. Fitness profiles of elite adolescent Irish rugby union players. J Strength Cond Res 32(1): 105-112, 2018-Rugby unions throughout the world are implementing player development models to prepare young players to meet the demands of professional rugby union. An example of this is the Irish Rugby Football Union Long Term Player Development model. The purpose of this study was to provide normative data relating to the physical fitness of elite adolescent Irish rugby union players and determine the differences in the physical capacities between players in the forward and back units as well as to provide descriptive data for the position categorizations within these units for this unique population. Players in the forward unit were significantly taller and heavier than players in the back unit (1.85 ± 0.06 m and 96.88 ± 9.00 kg vs. 1.79 ± 0.05 m and 81.97 ± 7.09 kg, respectively). Forwards (38.37 ± 4.00 cm) had a significantly lower countermovement jump height than backs (41.31 ± 4.44 cm). Forwards had a significantly lower triple hop for the distance score on their right (5.78 ± 0.52 m) and left (5.78 ± 0.55 m) legs compared with backs (6.26 ± 0.42 m and 6.33 ± 0.45 m, respectively). Forwards (1.85 ± 0.07 seconds) had a significantly higher 10-m sprint time than backs (1.77 ± 0.06 seconds). Furthermore, forwards (675.90 ± 82.46 m) had a significantly lower 150-m shuttle test score than backs (711.71 ± 27.46 m). The results of this study provide normative data for players who currently possess underage international potential and could be used by strength and conditioning coaches to guide the selection of players through talent identification processes.

  20. Fitness profiling in handball: physical and physiological characteristics of elite players.

    PubMed

    Sporis, Goran; Vuleta, Dinko; Vuleta, Dinko; Milanović, Dragan

    2010-09-01

    The purpose of this study was to describe the structural and functional characteristics of elite Croatian handball players and to evaluate whether the players in different positional roles have different physical and physiological profiles. According to the positional roles, players were categorized as goalkeepers (n = 13), wing players (n = 26), backcourt players (n = 28) and pivot players (n = 25). The goalkeepers were older (p < 0.01), and the pivot players were more experienced (p < 0.01) than the backcourt players. The wings were the shortest players in the team. The pivots were tallest and heavier than the backcourt and wing players (p < 0.01), whereas the backcourt players were tallest then wings (p < 0.01). Goalkeepers had more body fat than the backcourt and wing players (p < 0.01). The backcourt players had a lower percentage of body fat. The backcourt players were the quickest players in the team when looking at values of maximal running speed on a treadmill. The Goalkeepers were the slowest players in the team (p < 0.01). The best average results concerning maximal heart rate were detected among the backcourt players. There were no statistically significant differences between the players'positions when measuring blood lactate and maximal heart rate. A strong negative correlation was found between body fat and maximal running speed (r = -0.68, p < 0.01). Coaches are able to use this information to determine which type of profile is needed for a specific position. Experienced coaches can used this information in the process of designing a training program to maximize the fitness development of handball players, with one purpose only, to achieve success in handball.

  1. Concussion Prevalence in Competitive Ultimate Frisbee Players

    PubMed Central

    Lazar, Damien J.; Lichtenstein, Jonathan D.; Tybor, David J.

    2018-01-01

    Background: Ultimate Frisbee (ultimate) is a fast-growing, popular sport played nationally by over 4 million athletes. While several studies have examined injury rates in ultimate, no work has investigated the prevalence of concussions specifically or players’ knowledge and management of those injuries. Purpose: To estimate the lifetime prevalence of concussions in ultimate and to assess players’ knowledge of concussions as well as their concussion management behaviors. Study Design: Descriptive epidemiology study. Methods: From June to November 2015, we collected ultimate-related concussion data via an anonymous web-based survey, the Concussion in Ultimate Frisbee Survey, from a convenience sample of 787 male and female ultimate players across the United States. Results: There were 553 male and 234 female respondents included in the analysis; 26.58% of men and 24.79% of women reported that they had sustained at least 1 concussion while playing ultimate, with 45.58% and 43.10% of those men and women, respectively, reporting multiple concussions. A total of 67.81% of men and 78.21% of women stated that they would remove themselves from play after sustaining a given concussion, although 45.99% of men and 37.62% of women indicated that they had returned to play in the same game or practice. Conclusion: Our preliminary data suggest that concussions do commonly occur in competitive ultimate and that better education and management of concussions in ultimate athletes are needed. This study is an important first step in deepening our understanding of these issues. PMID:29552572

  2. Protective equipment and player characteristics associated with the incidence of sport-related concussion in high school football players: a multifactorial prospective study.

    PubMed

    McGuine, Timothy A; Hetzel, Scott; McCrea, Michael; Brooks, M Alison

    2014-10-01

    The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Cohort study; Level of evidence, 2. Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players' demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. A total of 2081 players (grades 9-12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%-11.0%]), Schutt (680, 8.7% [6.7%-11.1%]), or Xenith (436, 9.2% [6.7%-12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20-2.37], P < .001) than in players who wore a generic mouth guard. The rate of SRC was also higher (HR = 1.96 [95% CI, 1.40-2.73], P < .001) in players who had sustained an SRC within the previous 12 months (15.1% of the 259 players [95% CI, 11.0%-20.1%]) than in players without a previous SRC (8.2% of the 2028 players [95% CI, 7.1%-9.5%]). Incidence of SRC was similar regardless of the helmet brand (manufacturer) worn by high school

  3. Automatic acquisition of motion trajectories: tracking hockey players

    NASA Astrophysics Data System (ADS)

    Okuma, Kenji; Little, James J.; Lowe, David

    2003-12-01

    Computer systems that have the capability of analyzing complex and dynamic scenes play an essential role in video annotation. Scenes can be complex in such a way that there are many cluttered objects with different colors, shapes and sizes, and can be dynamic with multiple interacting moving objects and a constantly changing background. In reality, there are many scenes that are complex, dynamic, and challenging enough for computers to describe. These scenes include games of sports, air traffic, car traffic, street intersections, and cloud transformations. Our research is about the challenge of inventing a descriptive computer system that analyzes scenes of hockey games where multiple moving players interact with each other on a constantly moving background due to camera motions. Ultimately, such a computer system should be able to acquire reliable data by extracting the players" motion as their trajectories, querying them by analyzing the descriptive information of data, and predict the motions of some hockey players based on the result of the query. Among these three major aspects of the system, we primarily focus on visual information of the scenes, that is, how to automatically acquire motion trajectories of hockey players from video. More accurately, we automatically analyze the hockey scenes by estimating parameters (i.e., pan, tilt, and zoom) of the broadcast cameras, tracking hockey players in those scenes, and constructing a visual description of the data by displaying trajectories of those players. Many technical problems in vision such as fast and unpredictable players' motions and rapid camera motions make our challenge worth tackling. To the best of our knowledge, there have not been any automatic video annotation systems for hockey developed in the past. Although there are many obstacles to overcome, our efforts and accomplishments would hopefully establish the infrastructure of the automatic hockey annotation system and become a milestone for

  4. Risk Factors for Injuries in Professional Football Players.

    PubMed

    Haxhiu, Bekim; Murtezani, Ardiana; Zahiti, Bedri; Shalaj, Ismet; Sllamniku, Sabit

    2015-01-01

    The aim of this study was to identify risk factors related to the occurrence of injuries in football players. The study included 216 football players from 12 teams in the elite football league. Football-related injury data were collected prospectively during the 2012/2013 competitive season. At baseline the following information was collected for the players: anthropometric measurements (weight, height, BMI, subcutaneous skinfolds), playing experience, injury history, physical fitness performance test (agility run), peak oxygen uptake. The incidence, type and severity of injuries and training and game exposure times were prospectively documented for each player. Most of the players (n = 155, 71.7%) sustained the injures during the study period. The overall injury incidence during the regular season was 6.3 injuries per 1000 athlete-exposures (95% confidence interval, 4.31-9.67). Multivariate logistic regression analysis showed that playing experience (odds ratio [OR] = 0.44; 95% CI = 0.32-0.61, p < 0.01), age (OR = 2.05; 95% CI = 1.49-2.81, p < 0.01) and a previous injury (OR = 4.4; 95% CI = 2.14-9.07, p < 0.01) were significantly correlated to increased risk of injuries. Body mass index was not associated with risk of injury. Strains (34.19%) and sprains (25.81%) were the major injury types. Twenty-seven percent of injured players were absent from football for more than 1 month, with knee injuries (25.42%) being the most severe type. The risk factors that increase injury rates in football players were previous injury, higher age and years of playing. Future research should include adequate rehabilitation program to reduce the risk of injuries.

  5. Cavum Septum Pellucidum in Retired American Pro-Football Players.

    PubMed

    Gardner, Raquel C; Hess, Christopher P; Brus-Ramer, Marcel; Possin, Katherine L; Cohn-Sheehy, Brendan I; Kramer, Joel H; Berger, Mitchel S; Yaffe, Kristine; Miller, Bruce; Rabinovici, Gil D

    2016-01-01

    Previous studies report that cavum septum pellucidum (CSP) is frequent among athletes with a history of repeated traumatic brain injury (TBI), such as boxers. Few studies of CSP in athletes, however, have assessed detailed features of the septum pellucidum in a case-control fashion. This is important because prevalence of CSP in the general population varies widely (2% to 85%) between studies. Further, rates of CSP among American pro-football players have not been described previously. We sought to characterize MRI features of the septum pellucidum in a series of retired pro-football players with a history of repeated concussive/subconcussive head traumas compared with controls. We retrospectively assessed retired American pro-football players presenting to our memory clinic with cognitive/behavioral symptoms in whom structural MRI was available with slice thickness ≤2 mm (n=17). Each player was matched to a memory clinic control patient with no history of TBI. Scans were interpreted by raters blinded to clinical information and TBI/football history, who measured CSP grade (0-absent, 1-equivocal, 2-mild, 3-moderate, 4-severe) and length according to a standard protocol. Sixteen of 17 (94%) players had a CSP graded ≥2 compared with 3 of 17 (18%) controls. CSP was significantly higher grade (p<0.001) and longer in players than controls (mean length±standard deviation: 10.6 mm±5.4 vs. 1.1 mm±1.3, p<0.001). Among patients presenting to a memory clinic, long high-grade CSP was more frequent in retired pro-football players compared with patients without a history of TBI.

  6. Maturity status of youth football players: a noninvasive estimate.

    PubMed

    Malina, Robert M; Cumming, Sean P; Morano, Peter J; Barron, Mary; Miller, Susan J

    2005-06-01

    To estimate the biological maturity status of youth football players 9-14 yr old using a noninvasive method and to compare the body size of players of contrasting status. Subjects were members of youth football teams in two central Michigan communities. Height and weight were measured on 653 boys 8.7-14.6 yr. Heights of biological parents of 582 boys were reported and subsequently adjusted for overestimation. Decimal age, height, and weight of the player and midparent height were used to predict mature (adult) height for the boy. Current height of each player was expressed as a percentage of his predicted mature height to provide an estimate of biological maturity status. Percentage of predicted mature height of each boy was expressed as a z-score to classify players into maturity groups. ANCOVA, controlling for age, was used to compare body size in contrasting maturity groups. Mean percentages of predicted mature height of the players matched those of longitudinal reference samples, but there was a trend for higher percentages among older players, suggesting advanced maturation. Overall, 405 boys were classified as on time/average in maturity status (69.6% [95%CI 65.7-73.3]), 154 were classified as early/advanced (25.5% [95%CI 23.0-30.3]), and only 23 were classified as late/delayed (3.9% [95%CI 2.6-6.0]). The gradient for height, weight, and BMI was as follows: early > on time > late, and differences were greater for weight and the BMI than for height. Percentage of predicted mature height attained at a given age appears to be a reasonable indicator of maturity status. The method needs to be validated with other more direct indicators (skeletal age, sexual maturation) and applied to other samples.

  7. Specific Shoulder Pathoanatomy in Semiprofessional Water Polo Players

    PubMed Central

    Klein, Maria; Tarantino, Ignazio; Warschkow, René; Berger, Claus Joachim; Zdravkovic, Vilijam; Jost, Bernhard; Badulescu, Michael

    2014-01-01

    Background: Shoulders of throwing and swimming athletes are highly stressed joints that often show structural abnormalities on magnetic resonance imaging (MRI). However, while water polo players exhibit a combination of throwing and swimming movements, a specific pattern of pathological findings has not been described. Purpose: To assess specific MRI abnormalities in shoulders of elite water polo players and to compare these findings with a healthy control group. Study Design: Cross-sectional study; Level of evidence, 3. Methods: After performing a power analysis, volunteers were recruited for this study. Both shoulders of 28 semiprofessional water polo players and 15 healthy volunteers were assessed clinically (based on the Constant score) and had bilateral shoulder MRIs. The shoulders were clustered into 3 groups: 28 throwing and 28 nonthrowing shoulders of water polo athletes and 30 shoulders of healthy control subjects. Results: Twenty-eight male water polo players with an average age of 24 years and 15 healthy subjects (30 shoulders) with an average age of 31 years were examined. Compared with controls, significantly more MRI abnormalities in the water polo players' throwing shoulders could be found in the subscapularis, infraspinatus, and posterior labrum (P = .001, P = .024, and P = .041, respectively). Other structures showed no statistical differences between the 3 groups, including the supraspinatus tendon, which had abnormalities in 36% of throwing versus 32% of nonthrowing shoulders and 33% of control shoulders. All throwing shoulders showed abnormal findings in the MRI, but only 8 (29%) were symptomatic. Conclusion: The shoulders of semiprofessional water polo players demonstrated abnormalities in subscapularis and infraspinatus tendons that were not typical abnormalities for swimmers or throwing athletes. Clinical Relevance: The throwing shoulders of water polo players have specific MRI changes. Clinical symptoms do not correlate with the MRI findings

  8. Nutrition Status of Young Elite Female German Football Players.

    PubMed

    Braun, Hans; von Andrian-Werburg, Judith; Schänzer, Wilhelm; Thevis, Mario

    2018-02-01

    To investigate energy intake, energy expenditure, and the nutritional status of young female elite football players using 7-day food and activity records and blood parameters. A total of 56 female elite football players [14.8 (0.7) y] completed the requested food and activity protocols. Misreporting was assessed by the ratio of energy intake to energy expenditure. The food records were analyzed concerning energy and macronutrient and micronutrient intakes, and energy expenditure was calculated using predictive equations. Hematological data and 25-hydroxyvitamin D serum concentrations were determined. Mean energy intake was 2262 (368) kcal/d [40.5 (7.0) kcal/kg/d] and estimated EE averaged 2403 (195) kcal/d. Fifty-three percent of the players exhibited an energy availability <30 kcal/kg lean body mass; 31% of the athletes consumed <5 g/kg carbohydrates and 34% consumed <1.2 g/kg proteins. A large proportion of players (%) had intakes below the recommended daily allowance of folate (75%), vitamin D (100%), iron (69%), and calcium (59%). Ferritin and 25-hydroxyvitamin D serum levels were below the recommendations of 59% and 38%, respectively. A remarkable number of players failed to meet the energy balance and the recommended carbohydrate and protein intakes. Low iron and 25-hydroxyvitamin D serum levels were observed showing a suboptimal nutrition status of some young female football players. As a consequence, strategies have to be developed for a better information and application of sport nutrition practice among young female football players.

  9. N-Player Quantum Games in an EPR Setting

    PubMed Central

    Chappell, James M.; Iqbal, Azhar; Abbott, Derek

    2012-01-01

    The -player quantum games are analyzed that use an Einstein-Podolsky-Rosen (EPR) experiment, as the underlying physical setup. In this setup, a player’s strategies are not unitary transformations as in alternate quantum game-theoretic frameworks, but a classical choice between two directions along which spin or polarization measurements are made. The players’ strategies thus remain identical to their strategies in the mixed-strategy version of the classical game. In the EPR setting the quantum game reduces itself to the corresponding classical game when the shared quantum state reaches zero entanglement. We find the relations for the probability distribution for -qubit GHZ and W-type states, subject to general measurement directions, from which the expressions for the players’ payoffs and mixed Nash equilibrium are determined. Players’ payoff matrices are then defined using linear functions so that common two-player games can be easily extended to the -player case and permit analytic expressions for the Nash equilibrium. As a specific example, we solve the Prisoners’ Dilemma game for general . We find a new property for the game that for an even number of players the payoffs at the Nash equilibrium are equal, whereas for an odd number of players the cooperating players receive higher payoffs. By dispensing with the standard unitary transformations on state vectors in Hilbert space and using instead rotors and multivectors, based on Clifford’s geometric algebra (GA), it is shown how the N-player case becomes tractable. The new mathematical approach presented here has wide implications in the areas of quantum information and quantum complexity, as it opens up a powerful way to tractably analyze N-partite qubit interactions. PMID:22606258

  10. Australian Football League concussion guidelines: what do community players think?

    PubMed Central

    White, Peta E; Donaldson, Alex; Sullivan, S John; Newton, Joshua

    2016-01-01

    Background Preventing concussion in sport is a global challenge. To assess community-level adult male Australian Football players’ views on following the Australian Football League's (AFL) concussion guidelines. Methods 3 focus groups, each comprising 6 players from 1 regional league, were conducted until saturation of issues raised. Discussions followed a semistructured script and were audio-recorded and transcribed verbatim. Thematic analysis was conducted by 2 coders independently. Results Identified advantages of the guidelines included highlighting the seriousness of concussion; changing the culture around playing with concussion and shifting return-to-play decision responsibility from players to others. Disadvantages included players being removed from play unnecessarily; removal of players’ rights to decide if they are fit to play and players changing their behaviours to avoid being removed from play. Identified facilitators to guideline use included local league enforcement; broad information dissemination and impartial medically trained staff to assess concussion. Identified barriers to guideline use included players’ desire to play at all costs; external pressure that encouraged players to return to play prematurely; and inconvenience and cost. Conclusions Players generally understand that the AFL concussion guidelines protect their long-term welfare. However, their desire to play at all costs and help their team win is a common barrier to reporting concussion and adhering to guidelines. Leagues should take a lead role by mandating and enforcing the use of the guidelines and educating coaches, game day medical providers and players. The return-to-play component of the guidelines is complex and needs further consideration in the context of community sport. PMID:28890801

  11. Introducing JCE Online

    NASA Astrophysics Data System (ADS)

    1998-01-01

    One of the many transitions that occurred while moving the Journal editorial offices from Austin to Madison was the unification of the WWW sites of the Journal and JCE Software into JCE Online. Since that time JCE Online has provided several valuable resources to the chemistry education community. With the introduction of JCE Online+ (see below), we have expanded these resources and have plans to expand them even further. We thought that the Journal readership might like to know what is available to them at JCE Online. That's what this new column will do each month. JCE Online is divided into several areas. Each constituent part maintains an area at JCE Online: this Journal, JCE Software, JCE Internet, and JCE Books. There also is an area that lists Chemical Education Happenings and an area that contains information About JCE.

  12. The Development of the Problematic Online Gaming Questionnaire (POGQ)

    PubMed Central

    Demetrovics, Zsolt; Urbán, Róbert; Nagygyörgy, Katalin; Farkas, Judit; Griffiths, Mark D.; Pápay, Orsolya; Kökönyei, Gyöngyi; Felvinczi, Katalin; Oláh, Attila

    2012-01-01

    Background Online gaming has become increasingly popular. However, this has led to concerns that these games might induce serious problems and/or lead to dependence for a minority of players. Aim: The aim of this study was to uncover and operationalize the components of problematic online gaming. Methods A total of 3415 gamers (90% males; mean age 21 years), were recruited through online gaming websites. A combined method of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) was applied. Latent profile analysis was applied to identify persons at-risk. Results EFA revealed a six-factor structure in the background of problematic online gaming that was also confirmed by a CFA. For the assessment of the identified six dimensions – preoccupation, overuse, immersion, social isolation, interpersonal conflicts, and withdrawal – the 18-item Problematic Online Gaming Questionnaire (POGQ) proved to be exceedingly suitable. Based on the latent profile analysis, 3.4% of the gamer population was considered to be at high risk, while another 15.2% was moderately problematic. Conclusions The POGQ seems to be an adequate measurement tool for the differentiated assessment of gaming related problems on six subscales. PMID:22590541

  13. The development of the Problematic Online Gaming Questionnaire (POGQ).

    PubMed

    Demetrovics, Zsolt; Urbán, Róbert; Nagygyörgy, Katalin; Farkas, Judit; Griffiths, Mark D; Pápay, Orsolya; Kökönyei, Gyöngyi; Felvinczi, Katalin; Oláh, Attila

    2012-01-01

    Online gaming has become increasingly popular. However, this has led to concerns that these games might induce serious problems and/or lead to dependence for a minority of players. The aim of this study was to uncover and operationalize the components of problematic online gaming. A total of 3415 gamers (90% males; mean age 21 years), were recruited through online gaming websites. A combined method of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) was applied. Latent profile analysis was applied to identify persons at-risk. EFA revealed a six-factor structure in the background of problematic online gaming that was also confirmed by a CFA. For the assessment of the identified six dimensions--preoccupation, overuse, immersion, social isolation, interpersonal conflicts, and withdrawal--the 18-item Problematic Online Gaming Questionnaire (POGQ) proved to be exceedingly suitable. Based on the latent profile analysis, 3.4% of the gamer population was considered to be at high risk, while another 15.2% was moderately problematic. The POGQ seems to be an adequate measurement tool for the differentiated assessment of gaming related problems on six subscales.

  14. Online use statistics.

    PubMed

    Tannery, Nancy Hrinya; Silverman, Deborah L; Epstein, Barbara A

    2002-01-01

    Online use statistics can provide libraries with a tool to be used when developing an online collection of resources. Statistics can provide information on overall use of a collection, individual print and electronic journal use, and collection use by specific user populations. They can also be used to determine the number of user licenses to purchase. This paper focuses on the issue of use statistics made available for one collection of online resources.

  15. Virtual Voices: Online Teachers' Perceptions of Online Teaching Standards

    ERIC Educational Resources Information Center

    Smith, Robin Davidson

    2009-01-01

    Online teachers' perceptions of online teaching standards published in 2006 by the Southern Regional Education Board (SREB) and the National Education Association (NEA). Interviews with two teachers from each of the four online schools were studied following an online survey of 49 online teachers from these schools. Overall, participants reported…

  16. The Online Bingo Boom in the UK: A Qualitative Examination of Its Appeal

    PubMed Central

    2016-01-01

    Online bingo has seen significant growth in recent years. This study sought to increase understanding of this growth by exploring the appeal of online bingo. Our aim was to examine the content of ten online bingo websites in the UK and analyse a qualitative secondary dataset of 12 female bingo players to investigate the appeal of online bingo. Using two distinct data sources allowed us to assess how the key messages online websites are trying to convey compare with actual players’ motivation to play bingo. Our analysis of bingo websites found a common theme where websites were easy to navigate and structured to present a light-hearted, fun, reassuring, social image of gambling. In addition, the design decisions reflected in the bingo sites had the effect of positioning online bingo as a benign, child-like, homely, women-friendly, social activity. Comparison of the website content with our participants’ reasons to play bingo showed congruence between the strategies used by the bingo websites and the motivations of bingo players themselves and the benefits which they seek; suggesting that bingo websites strive to replicate and update the sociability of traditional bingo halls. Online bingo differs from traditional forms of bingo in its ability to be played anywhere and at any time, and its capacity to offer a deeply immersive experience. The potential for this type of online immersion in gambling to lead to harm is only just being investigated and further research is required to understand how the industry is regulated, as well as the effects of online bingo on individual gambling ‘careers.’ PMID:27138116

  17. Iliopsoas and Gluteal Muscles Are Asymmetric in Tennis Players but Not in Soccer Players

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A. L.; Dorado, Cecilia

    2011-01-01

    Purpose To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players. Methods IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively). Results The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05) and SP (32 and 35%, respectively, P<0.05). In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01) reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01), whilst soccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = −0.97, P<0.001), SP (r = −0.85, P<0.01) and CG (r = −0.76, P<0.05). The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05), whilst TP and CG had similar dominant GL volumes (P = 0.14). Conclusions Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury. PMID:21829539

  18. Lateral Scapular Slide Test and Scapular Mobility in Volleyball Players

    PubMed Central

    Ozunlu, Nihan; Tekeli, Hatice; Baltaci, Gul

    2011-01-01

    Context: The stability of the scapula in relation to the entire moving upper extremity is the key in the throwing sequence. The importance of scapular positioning in volleyball players has been well documented in the literature, but no one has compared scapular positioning between volleyball players and sedentary people. Objective: To compare measurements of scapular mobility obtained using the lateral scapular slide test between volleyball players and sedentary participants without shoulder impairments and to compare changes in scapular mobility in players according to the number of years of sport participation. Design: Cross-sectional study. Setting: University research laboratory. Patients or Other Participants: A total of 121 people at a single university volunteered. Of these, 67 were sedentary (age = 24.3 ± 2.34 years, height = 1.69 ± 0.09 m, mass = 65.1 ± 11.91 kg); 54 were volleyball players from 4 professional teams and were separated into 2 groups according to their years of sport participation. The first group was named young players (n = 31; age = 17.7 ± 2.58 years, height = 1.83 ± 0.10 m, mass = 68.3 ± 12.21 kg, sport participation ≤ 9 years), and the second group was named old players (n = 23; age = 26.9 ± 3.39 years, height = 1.95 ± 4.38 m, mass = 90.7 ± 5.75 kg, sport participation ≥ 10 years). Main Outcome Measure(s): Study participants completed a rating scale for pain and a questionnaire about demographic and shoulder problems. One assessor performed the lateral scapular slide test and additional flexibility measurements around the shoulder girdle. Flexibility (external rotation, internal rotation) and scapular position (1, 2, 3) were compared among groups (young players, old players, sedentary people) and between sides (dominant, nondominant). Results: In sedentary participants, we found differences for position 1 (t66 = 3.327, P = .002), position 2 (t66 = 2.491, P = .004), position 3 (t66 = 2.512, P = .006), and internal rotation

  19. Athletic performance outcomes following lumbar discectomy in professional basketball players.

    PubMed

    Anakwenze, Okechukwu A; Namdari, Surena; Auerbach, Joshua D; Baldwin, Keith; Weidner, Zachary D; Lonner, Baron S; Huffman, G R; Sennett, Brian J

    2010-04-01

    Retrospective case-control study. To quantify the athletic performance profiles after lumbar discectomy (LD) in a cohort of National Basketball Association (NBA) players in comparison with a control group of matched NBA players who did not undergo LD during the same study period. LD provides symptomatic relief and improved functional outcomes in the majority of patients as assessed by validated measures such as Oswestry Disability Index, Visual Analog Scale, and Short Form-36 (SF-36). Among professional athletes, however, the goal of lumbar HNP treated by discectomy is not only to improve functional status but also, ultimately, to return the player to preinjury athletic performance levels. No study to date has compared the athletic performance profiles before and after discectomy in professional athletes. An analysis of NBA games summaries, weekly injury reports, player profiles, and press releases was performed to identify 24 NBA players who underwent LD for symptomatic lumbar HNP between 1991 and 2007. A 1:2 case: control study was performed using players without history of lumbar HNP who were matched for age, position, experience, and body mass index as control subjects (n = 48). Paired t tests were conducted on the following parameters: games played, minutes per game, points per 40 minutes, rebounds per 40 minutes, assists per 40 minutes, steals per 40 minutes, blocks per 40 minutes, and shooting percentage. For each athletic performance outcome, between-group comparisons evaluating preindex to postindex season performance were done (index season = season of surgery). In the LD group, 18 of 24 players (75%) returned to play again in the NBA, compared with 42 of 48 players (88%, P = 0.31) in the control group. One year after surgery, between-group comparisons revealed statistically significant increase in blocked shots per 40 minutes in the LD (0.18) versus control group (-0.33; P = 0.008) and a smaller decrease in rebounds per 40 minutes in the LD (-0

  20. Incidence and player risk factors for injury in youth football.

    PubMed

    Malina, Robert M; Morano, Peter J; Barron, Mary; Miller, Susan J; Cumming, Sean P; Kontos, Anthony P

    2006-05-01

    To estimate the incidence of injuries in youth football and to assess the relationship between player-related risk factors (age, body size, biological maturity status) and the occurrence of injury in youth football. Prospective over two seasons. Two communities in central Michigan. Subjects were 678 youth, 9-14 years of age, who were members of 33 youth football teams in two central Michigan communities in the 2000 and 2001 seasons. Certified athletic trainers (ATCs) were on site to record the number of players at all practices and home games (exposures) and injuries as they occurred. A reportable injury (RI) was defined by the criteria used in the National Athletic Trainers' Association (NATA) survey of several high school sports. Estimated injury rates (95% confidence intervals) per athlete exposures (AE) and per number of athletes were calculated for practices and games by grade. Player risk factors included age, height, weight, BMI and estimated maturity status. Estimated injury rates and relative risks of injury during practices and games by grade; logistic regression to evaluate relationships between player-related risk factors and risk of injury. A total of 259 RIs, 178 in practice and 81 in games, were recorded during the two seasons. Practice injury rates increased with grade level, while game injury rates were similar among fourth through fifth grade and sixth grade players and about twice as high among seventh and eighth grade players. The majority of RIs during the two seasons was minor (64%); the remainder was moderate (18%) and major (13%). Injured fourth through fifth grade players were significantly lighter in weight and had a lower BMI; otherwise, injured and non-injured players within each grade did not differ in age, body size and estimated biological maturity status. Logistic regressions within grade revealed no significant associations between injury and age, height, BMI, and maturity status. Game injury rates are higher than practice injury

  1. Epidemiology of neurodegeneration in American-style professional football players

    PubMed Central

    2013-01-01

    The purpose of this article is to review the history of head injuries in relation to American-style football play, summarize recent research that has linked football head injuries to neurodegeneration, and provide a discussion of the next steps for refining the examination of neurodegeneration in football players. For most of the history of football, the focus of media reports and scientific studies on football-related head injuries was on the acute or short-term effects of serious, traumatic head injuries. Beginning about 10 years ago, a growing concern developed among neurologists and researchers about the long-term effects that playing professional football has on the neurologic health of the players. Autopsy-based studies identified a pathologically distinct neurodegenerative disorder, chronic traumatic encephalopathy, among athletes who were known to have experienced concussive and subconcussive blows to the head during their playing careers. Football players have been well represented in these autopsy findings. A mortality study of a large cohort of retired professional football players found a significantly increased risk of death from neurodegeneration. Further analysis found that non-line players were at higher risk than line players, possibly because of an increased risk of concussion. Although the results of the studies reviewed do not establish a cause effect relationship between football-related head injury and neurodegenerative disorders, a growing body of research supports the hypothesis that professional football players are at an increased risk of neurodegeneration. Significant progress has been made in the last few years on detecting and defining the pathology of neurodegenerative diseases. However, less progress has been made on other factors related to the progression of those diseases in football players. This review identifies three areas for further research: (a) quantification of exposure - a consensus is needed on the use of clinically

  2. Epidemiology of neurodegeneration in American-style professional football players.

    PubMed

    Lehman, Everett J

    2013-01-01

    The purpose of this article is to review the history of head injuries in relation to American-style football play, summarize recent research that has linked football head injuries to neurodegeneration, and provide a discussion of the next steps for refining the examination of neurodegeneration in football players. For most of the history of football, the focus of media reports and scientific studies on football-related head injuries was on the acute or short-term effects of serious, traumatic head injuries. Beginning about 10 years ago, a growing concern developed among neurologists and researchers about the long-term effects that playing professional football has on the neurologic health of the players. Autopsy-based studies identified a pathologically distinct neurodegenerative disorder, chronic traumatic encephalopathy, among athletes who were known to have experienced concussive and subconcussive blows to the head during their playing careers. Football players have been well represented in these autopsy findings. A mortality study of a large cohort of retired professional football players found a significantly increased risk of death from neurodegeneration. Further analysis found that non-line players were at higher risk than line players, possibly because of an increased risk of concussion. Although the results of the studies reviewed do not establish a cause effect relationship between football-related head injury and neurodegenerative disorders, a growing body of research supports the hypothesis that professional football players are at an increased risk of neurodegeneration. Significant progress has been made in the last few years on detecting and defining the pathology of neurodegenerative diseases. However, less progress has been made on other factors related to the progression of those diseases in football players. This review identifies three areas for further research: (a) quantification of exposure - a consensus is needed on the use of clinically

  3. Quadriceps tendon injuries in national football league players.

    PubMed

    Boublik, Martin; Schlegel, Theodore F; Koonce, Ryan C; Genuario, James W; Kinkartz, Jason D

    2013-08-01

    Distal quadriceps tendon tears are uncommon injuries that typically occur in patients older than 40 years of age, and they have a guarded prognosis. Predisposing factors, prodromal findings, mechanisms of injury, treatment guidelines, and recovery expectations are not well described in high-level athletes. Professional American football players with an isolated tear of the quadriceps tendon treated with timely surgical repair will return to their sport. Case series; Level of evidence, 4. Fourteen unilateral distal quadriceps tendon tears were identified in National Football League (NFL) players from 1994 to 2004. Team physicians retrospectively reviewed training room and clinic records, operative notes, and imaging studies for each of these players. Data on each player were analyzed to identify variables predicting return to play. A successful outcome was defined as returning to play in regular-season NFL games. Eccentric contraction of the quadriceps was the most common mechanism of injury, occurring in 10 players. Only 1 player had antecedent ipsilateral extensor mechanism symptoms. Eleven players had a complete rupture of the quadriceps tendon, and 3 had partial tears. There were no associated knee injuries. All ruptures were treated with surgical repair, 1 of which was delayed after failure of nonoperative treatment. Fifty percent of players returned to play in regular-season NFL games. There was a trend toward earlier draft status for those who returned to play compared with those who did not (draft round, 3.1 ± 2.5 vs. 6.0 ± 2.9, respectively; P = .073). For those who returned to play, the average number of games after injury was 40.9 (range, 12-92). Quadriceps tendon tears are rare in professional American football players, and they usually occur from eccentric load on the extensor mechanism. Prodromal symptoms and predisposing factors are usually absent. Even with timely surgical repair, there is a low rate of return to play in regular-season games. There

  4. Concussion among female middle-school soccer players.

    PubMed

    O'Kane, John W; Spieker, Amy; Levy, Marni R; Neradilek, Moni; Polissar, Nayak L; Schiff, Melissa A

    2014-03-01

    Despite recent increased awareness about sports concussions, little research has evaluated concussions among middle-school athletes. To evaluate the frequency and duration of concussions in female youth soccer players and to determine if concussions result in stopping play and seeking medical care. Prospective cohort study from March 2008 through May 2012 among 4 soccer clubs from the Puget Sound region of Washington State, involving 351 elite female soccer players, aged 11 to 14 years, from 33 randomly selected youth soccer teams. Of the players contacted, 83.1% participated and 92.4% completed the study. Concussion cumulative incidence, incidence rate, and description of the number, type, and duration of symptoms. We inquired weekly about concussion symptoms and, if present, the symptom type and duration, the event resulting in symptom onset, and whether the player sought medical attention or played while symptomatic. Among the 351 soccer players, there were 59 concussions with 43 742 athletic exposure hours. Cumulative concussion incidence was 13.0% per season, and the incidence rate was 1.2 per 1000 athletic exposure hours (95% CI, 0.9-1.6). Symptoms lasted a median of 4.0 days (mean, 9.4 days). Heading the ball accounted for 30.5% of concussions. Players with the following symptoms had a longer recover time than players without these symptoms: light sensitivity (16.0 vs 3.0 days, P = .001), emotional lability (15.0 vs 3.5 days, P = .002), noise sensitivity (12.0 vs 3.0 days, P = .004), memory loss (9.0 vs 4.0 days, P = .04), nausea (9.0 vs 3.0 days, P = .02), and concentration problems (7.0 vs 2.0 days, P = .02). Most players (58.6%) continued to play with symptoms, with almost half (44.1%) seeking medical attention. Concussion rates in young female soccer players are greater than those reported in older age groups, and most of those concussed report playing with symptoms. Heading the ball is a frequent precipitating event. Awareness

  5. Online shopping hesitation.

    PubMed

    Cho, Chang-Hoan; Kang, Jaewon; Cheon, Hongsik John

    2006-06-01

    This study was designed to understand which factors influence consumer hesitation or delay in online product purchases. The study examined four groups of variables (i.e., consumer characteristics, contextual factors perceived uncertainty factors, and medium/channel innovation factors) that predict three types of online shopping hesitation (i.e., overall hesitation, shopping cart abandonment, and hesitation at the final payment stage). We found that different sets of delay factors are related to different aspects of online shopping hesitation. The study concludes with suggestion for various delay-reduction devices to help consumers close their online decision hesitation.

  6. Special considerations in the medical management of professional basketball players.

    PubMed

    Steingard, S A

    1993-04-01

    The NBA basketball players are among the finest athletes in the world. That along with the increased popularity of the NBA has put a premium on the health of the players. The course of the season puts tremendous stress and strain on players. As medical illnesses occur, the physician may feel increased pressure to put the ill player back into the line-up. One cannot let the pressure for the player to return to activity interfere with good medical practice. At times, it is difficult to allow for the natural course of an illness, however, as discussed in this article, sometimes this is exactly what needs to be done. The temptation to overtreat is also seen in some team physicians. This too must be avoided. Along with proper treatment, there is the need for education of the athletes both in social interactions and in diet and life-style. Then we, as team physicians, can sit back and enjoy the performance on the court.

  7. Injuries of the obturator muscles in professional soccer players.

    PubMed

    Wong-On, Manuel; Turmo-Garuz, Antonio; Arriaza, Rafael; Gonzalez de Suso, Jose Manuel; Til-Perez, Luis; Yanguas-Leite, Xavier; Diaz-Cueli, David; Gasol-Santa, Xavier

    2017-02-10

    Obturator externus and internus muscular tears are uncommon injuries. Only a few case reports exist, mainly in high-level athletes. Our aim is to describe a series of obturator externus and internus muscular tears in professional soccer players. Injury data from four teams from the First Division of the Spanish Soccer League were collected over a total of four seasons. Any soccer player who sustained an injury to either the obturator externus or internus identified on magnetic resonance (MRI) was included. All injured players were treated non-operatively with a goal of returning to play as fast as possible. Sixteen players sustained injuries to the obturator externus and internus during matches or training sessions. The main complaint was anterior hip pain with a physical examination showing pain during internal rotation or external rotation of the flexed hip. The MRI documented 12 muscular tears of the obturator externus, and 4 muscular tears of the obturator internus. All injuries were treated conservatively based on physical therapy, analgesic medications, and underwent a symptoms-based rehabilitation protocol. Mean return to play was 11.5  ±  8.8 days. Although uncommon, tears of the obturator externus and internus occur in professional soccer players. The MRI scan was essential to the location, classification, and evaluation of the injury size. The clinical relevance of our investigation is based on the relatively benign prognosis of these injuries. IV.

  8. Utilization of cues in action anticipation in table tennis players.

    PubMed

    Zhao, Qi; Lu, Yingzhi; Jaquess, Kyle J; Zhou, Chenglin

    2018-04-11

    By manipulating the congruency between body kinematics and subsequent ball trajectory, this study investigated the anticipation capabilities of regional-level, college-level, and novice table tennis players using a full video simulation occluder paradigm. Participants watched footage containing congruent, incongruent, or no ball trajectory information, to predict the landing point of the ball. They were required to choose between two potential locations to make their prediction. Percent accuracy and relevant indexes (d-prime, criterion, effect size) were calculated for each condition. Results indicated that experienced table tennis players (both regional and college players) were superior to novices in the ability to anticipate ball trajectory using kinematic information, but no difference was found between regional-level and college-level players. The findings of this study further demonstrate the superior anticipation ability of experienced table tennis players. Furthermore, the present result suggests that there may be a certain "baseline" level of motor experience in racquet sports for effective action anticipation, while the addition of further motor experience does not appear to assist direction anticipation.

  9. Magnitude of Head Impact Exposures in Individual Collegiate Football Players

    PubMed Central

    Wilcox, Bethany J.; Machan, Jason T.; McAllister, Thomas W.; Duhaime, Ann-Christine; Duma, Stefan M.; Rowson, Steven; Beckwith, Jonathan G.; Chu, Jeffrey J.; Greenwald, Richard M.

    2013-01-01

    The purpose of this study was to quantify the severity of head impacts sustained by individual collegiate football players and to investigate differences between impacts sustained during practice and game sessions, as well as by player position and impact location. Head impacts (N = 184,358) were analyzed for 254 collegiate players at three collegiate institutions. In practice, the 50th and 95th percentile values for individual players were 20.0 g and 49.5 g for peak linear acceleration, 1187 rad/s2 and 3147 rad/s2 for peak rotational acceleration, and 13.4 and 29.9 for HITsp, respectively. Only the 95th percentile HITsp increased significantly in games compared with practices (8.4%, p= .0002). Player position and impact location were the largest factors associated with differences in head impacts. Running backs consistently sustained the greatest impact magnitudes. Peak linear accelerations were greatest for impacts to the top of the helmet, whereas rotational accelerations were greatest for impacts to the front and back. The findings of this study provide essential data for future investigations that aim to establish the correlations between head impact exposure, acute brain injury, and long-term cognitive deficits. PMID:21911854

  10. The movement characteristics of English Premiership rugby union players.

    PubMed

    Cahill, Nicola; Lamb, Kevin; Worsfold, Paul; Headey, Roy; Murray, Stafford

    2013-01-01

    The purpose of this investigation was to quantify the movement characteristics of elite rugby union players during competitive play and identify whether position-related differences exist. Ninety-eight elite players from eight English Premiership Clubs were tracked using global positioning systems (GPS) during 44 competitive matches throughout the 2010/2011 season. Player positions were defined as: (1) backs or forwards; (2) front, second and back rows, scrum half, inside and outside backs; (3) 15 individual positions (numbers 1-15). Analysis revealed the game is predominantly played at low speeds with little distance covered 'sprinting' by either the backs (50 ± 76 m) or the forwards (37 ± 64 m). The backs travelled greater (P < 0.05) absolute and relative distances than the forwards. The scrum half covered the greatest total distance during a match (7098 ± 778 m) and the front row the least (5158 ± 200 m). The back row covered the greatest distances at 'sprinting' speeds, particularly the number 8 position (77 m). These findings reflect notable differences in the movement characteristics displayed by elite rugby union players in specific positional roles, and reinforce the contemporary view that training programmes for such players ought to be structured with this in mind.

  11. How the Iranian Football Coaches and Players Know About Doping?

    PubMed Central

    Seif Barghi, Tohid; Halabchi, Farzin; Dvorak, Jiri; Hosseinnejad, Heydar

    2015-01-01

    Background: Nowadays, doping is an intricate dilemma. Football is the nationally popular sport in Iran. On the other hand, doping is a serious health hazard sport faces today. Studies dealing with athletes’ knowledge, attitudes and behavior concerning doping in football are scarce. Objectives: Therefore, we aimed to investigate the knowledge and attitudes toward doping among the football coaches and players. Patients and Methods: In a cross sectional study, 375 participants (239 football players and 136 coaches) were studied. A specially made questionnaire was applied. In this study, football teams of different provinces of the country were selected by randomized clustered sampling and questionnaires were distributed among coaches and players. Results: Knowledge of football coaches and players in three categories of doping definitions, recognition of prohibited drugs and side effects of anabolic steroids was poor or moderate in 45.3%, 88.5% and 96.5%, respectively. Conclusions: Football players and coaches have poor knowledge about doping in Iran. Moreover, they believe in some inappropriate myths without any scientific or rational basis.It seems necessary to design a comprehensive educational program for all of the athletes and coaches in Iran. PMID:26448840

  12. Symmetry of proprioceptive sense in female soccer players.

    PubMed

    Iwańska, Dagmara; Karczewska, Magdalena; Madej, Anna; Urbanik, Czesław

    2015-01-01

    The purpose of the study was to assess the symmetry of proprioceptive sense among female soccer players when trying to reproduce isometric knee extensions (right and left) and to analyze the impact of a given level of muscle force on proprioception. The study involved 12 soccer players aged 19.5 ± 2.65 years. Soccer players performed a control measurement of a maximum 3s (knee at the 90°) position in the joint. Subsequently, 70%, 50%, and 30% of the maximum voluntary contraction (MVC) were all calculated and then reproduced by each subject with feedback. Next, the players reproduced the predefined muscle contraction values in three sequences: A - 50%, 70%, 30%; B - 50%, 30%, 70%; C - 70%, 30%, 50% of MVC without visual control. In every sequence, the participants found obtaining the value of 30% of MVC the most difficult. The value they reproduced most accurately was 70% of MVC. Both trial II and trial III demonstrated that the symmetry index SI significantly differed from values considered acceptable (SIRa). In each successive sequence the largest asymmetry occurred while reproducing the lowest values of MVC (30%) (p < 0.05). High level of prioprioceptive sense is important to soccer players due to the extensive overload associated with dynamics stops or changes in direction while running. Special attention should be paid to develop skills in sensing force of varying levels. It was much harder to reproduce the predefined values if there was no feedback.

  13. Efficiently detecting outlying behavior in video-game players

    PubMed Central

    Kim, Young Bin; Kang, Shin Jin; Lee, Sang Hyeok; Jung, Jang Young; Kam, Hyeong Ryeol; Lee, Jung; Kim, Young Sun; Lee, Joonsoo

    2015-01-01

    In this paper, we propose a method for automatically detecting the times during which game players exhibit specific behavior, such as when players commonly show excitement, concentration, immersion, and surprise. The proposed method detects such outlying behavior based on the game players’ characteristics. These characteristics are captured non-invasively in a general game environment. In this paper, cameras were used to analyze observed data such as facial expressions and player movements. Moreover, multimodal data from the game players (i.e., data regarding adjustments to the volume and the use of the keyboard and mouse) was used to analyze high-dimensional game-player data. A support vector machine was used to efficiently detect outlying behaviors. We verified the effectiveness of the proposed method using games from several genres. The recall rate of the outlying behavior pre-identified by industry experts was approximately 70%. The proposed method can also be used for feedback analysis of various interactive content provided in PC environments. PMID:26713250

  14. Etiology and Biomechanics of Tarsometatarsal Injuries in Professional Football Players

    PubMed Central

    Kent, Richard W.; Lievers, W. Brent; Riley, Patrick O.; Frimenko, Rebecca E.; Crandall, Jeff R.

    2014-01-01

    Background: Tarsometatarsal (TMT) dislocations are uncommon yet debilitating athletic injuries, particularly in American football. To date, the mechanisms of athletic TMT dislocation have been described only anecdotally. This lack of information confounds the development of preventative countermeasures. Purpose: To use video analysis to provide direct, independent identification of the etiologic and mechanistic variables responsible for TMT dislocations in professional football players. Study Design: Case series; Level of evidence, 4. Methods: Sixteen professional National Football League players who sustained publicly reported TMT dislocations were identified. Publicly broadcast game footage of the plays in which injury occurred was reviewed by a panel of 5 biomechanists. Consensus was reached regarding the details surrounding injury, and a weighting was assigned to each detail based on the panel’s confidence. Results: Roughly 90% of injuries occurred while the injured player was engaged with or by another player, a detail that has heretofore been undocumented. Few injuries resulted from direct loading of either the foot or the ipsilateral limb; however, the injured foot was frequently subjected to axial loading from ground engagement with the foot in plantar flexion and the toes dorsiflexed. Injurious loading was often due to external rotation of the midfoot (86%). Fifteen of 16 injuries were season ending. Conclusion: TMT dislocations are frequently associated with engagement by or with a second player but infrequently caused by a direct blow to the foot. Axial loading of the foot, external rotation, and pronation/supination are the most common conditions during injurious loading. PMID:26535306

  15. Predicting protein structures with a multiplayer online game.

    PubMed

    Cooper, Seth; Khatib, Firas; Treuille, Adrien; Barbero, Janos; Lee, Jeehyung; Beenen, Michael; Leaver-Fay, Andrew; Baker, David; Popović, Zoran; Players, Foldit

    2010-08-05

    People exert large amounts of problem-solving effort playing computer games. Simple image- and text-recognition tasks have been successfully 'crowd-sourced' through games, but it is not clear if more complex scientific problems can be solved with human-directed computing. Protein structure prediction is one such problem: locating the biologically relevant native conformation of a protein is a formidable computational challenge given the very large size of the search space. Here we describe Foldit, a multiplayer online game that engages non-scientists in solving hard prediction problems. Foldit players interact with protein structures using direct manipulation tools and user-friendly versions of algorithms from the Rosetta structure prediction methodology, while they compete and collaborate to optimize the computed energy. We show that top-ranked Foldit players excel at solving challenging structure refinement problems in which substantial backbone rearrangements are necessary to achieve the burial of hydrophobic residues. Players working collaboratively develop a rich assortment of new strategies and algorithms; unlike computational approaches, they explore not only the conformational space but also the space of possible search strategies. The integration of human visual problem-solving and strategy development capabilities with traditional computational algorithms through interactive multiplayer games is a powerful new approach to solving computationally-limited scientific problems.

  16. The consultation of rugby players in co-developing a player health study: feasibility and consequences of sports participants as research partners.

    PubMed

    Davies, Madeleine A M; Balai, Edward; Adams, Jo; Carter, John-Henry; Judge, Andrew; Newton, Julia L; Arden, Nigel K

    2017-01-01

    Many funding bodies within the United Kingdom and globally have encouraged public involvement in research. The Department of Health has also called public involvement a sign of good research. Despite the wide acceptance of public involvement improving many aspects of research, from its design to its communication, involvement has varied levels of implementation across different fields of research. Sports people have rarely been involved in research, partly as this research tends not to be funded by mainstream funding bodies. This may lead to a lower research quality, not founded in player ('service user') experiences. When creating a study of former rugby player health, we were very keen to involve rugby players, understand their thoughts on player health, and their playing experiences. This article explains how rugby players were involved in several ways, but mainly in group discussions during the design stage. These groups helped to inform our study's aims and questionnaire, ensure the questionnaire would capture player experiences and answer questions relevant to players, that they would like to understand after their participation in rugby. We found that these groups were easy to arrange, and that in only one session with each group, we were given many ideas of how to improve the questionnaire and study. We believe that other studies in sports should involve sports people, and that this is a useful activity that will change data collection forms and processes, improving the research, helping researchers, and making studies more suitable for players who take part in them. Background Patient and public involvement ('involvement') in the UK has increased in accordance with funding requirements, patient-centered health policy initiatives and reporting of the positive impact of involvement for those involved, research and researchers. However, involvement has not been implemented equally across all disease areas and populations. The aim of this process was to

  17. Going Online the MI Way.

    ERIC Educational Resources Information Center

    Feldt, Jill

    This booklet describes online searching using Materials Information, a metallurgy and metals science information service of the Institute of Metals in London and ASM International in Cleveland, Ohio, which is available through the major online vendors. Described in detail are online searching, online databases, costs, online hosts or vendors,…

  18. Teaching water sustainability and STEM concepts using in-class, online, and real-world multiplayer simulations

    NASA Astrophysics Data System (ADS)

    Moysey, S. M.; Hannah, A. C.; Miller, S.; Mobley, C.

    2013-12-01

    Serious games are computer games with a primary purpose other than entertainment. Serious games are frequently used for training purposes, and can be used for educational and research purposes, increasing student interest and level of interaction as well as allowing researchers to collect data about emergent player behavior. The Naranpur Express simulation is based on a previously existing multiplayer role-playing game, where each player manages a small farm in rural India. Player goals include subsistence, upward economic mobility, and mitigation of environmental impact. Hydrologic and agricultural models are used to connect each player's small-scale decisions with their more far-reaching, and often difficult to perceive environmental impacts. This approach allows students to learn by discovery, experiencing first-hand the challenges of overuse of groundwater, fertilizers, and pesticides. Integration of new and rapidly developing social media techniques allows players to discuss solutions to their shared challenges, and help define a set of formal or informal rules governing their community. Previous versions of this game were implemented on paper, or in a spreadsheet run on each student's laptop. However, moving this simulation to an interactive online setting will allow us to study aggregate, as well as spatially varying effects of player decisions on economic and environmental outcomes. By coupling both physical and economic models with the real dynamics of player behavior, and considering the social and cultural aspects of agriculture, we can investigate the decision-making processes that control real environmental outcomes. By varying the types of information available to players, we can investigate how access to different kinds of information drives environmental decision-making. This can help identify key misunderstandings, thereby benefiting education and outreach efforts related to environmental justice and sustainability issues. Surveys collected from

  19. Spinal mobility and trunk muscle strength in elite hockey players.

    PubMed

    Lindgren, S; Twomey, L

    1988-01-01

    Elite hockey players of both sexes from the Australian Institute of Sport were assessed for lumbar spine mobility, trunk flexion and back extensor muscle strength, hamstring flexibility and postural characteristics over a two year period. All the athletes were more mobile in rotation than the 'normal' West Australian population, and demonstrated flexible hamstrings and powerful back extensor muscles; trunk flexion was less strong initially, but improved after intervention in the form of a specific exercise programme, over the measurement period. A questionnaire disclosed that low back pain is a common complaint of hockey players, but rarely required intensive physical and medical treatment. The term 'hockey player's back' has been coined in recognition of the long flat thoracolumbar spine frequently noted in these subjects. Copyright © 1988 Australian Physiotherapy Association. Published by . All rights reserved.

  20. Three-player conflicting interest games and nonlocality

    NASA Astrophysics Data System (ADS)

    Bolonek-Lasoń, Katarzyna

    2017-08-01

    We outline the general construction of three-player games with incomplete information which fulfil the following conditions: (i) symmetry with respect to the permutations of players; (ii) the existence of an upper bound for total payoff resulting from Bell inequalities; (iii) the existence of both fair and unfair Nash equilibria saturating this bound. Conditions (i)-(iii) imply that we are dealing with conflicting interest games. An explicit example of such a game is given. A quantum counterpart of this game is considered. It is obtained by keeping the same utilities but replacing classical advisor by a quantum one. It is shown that the quantum game possesses only fair equilibria with strictly higher payoffs than in the classical case. This implies that quantum nonlocality can be used to resolve the conflict between the players.

  1. [Isokinetic testing of the shoulder of handball players].

    PubMed

    Michael, J W-P; König, D P; Bertram, C; Hessling, U; Eysel, P

    2005-09-01

    Aim of the study was to evaluate an isokinetic profile testing handball players to describe muscular imbalance. 30 athletes (15 male and 15 female) were measured at the Cybex 6000 test-unit for concentric internal and external rotation. Both shoulders, throwing arm (dominant shoulder) and the opposite shoulder were tested by speeds at 60 degrees/s and 180 degrees/s. There were sex specific differences which are also found in other sports. But these contrary data are not useful to define effective training concepts for handball-players with shoulder problems. From our point of view isokinetic testing of the shoulder joint in handball players can not reach any sufficient result. From our point of view there is no reason for using isokinetic testing to evaluate shoulder problems.

  2. Social responsibility tools in online gambling: a survey of attitudes and behavior among Internet gamblers.

    PubMed

    Griffiths, Mark D; Wood, Richard T A; Parke, Jonathan

    2009-08-01

    To date, little empirical research has focused on social responsibility in gambling. This study examined players' attitudes and behavior toward using the social responsibility tool PlayScan designed by the Swedish gaming company Svenska Spel. Via PlayScan, players have the option to utilize various social responsibility control tools (e.g., personal gaming budgets, self-diagnostic tests of gambling habits, self-exclusion options). A total of 2,348 participants took part in an online questionnaire study. Participants were clientele of the Svenska Spel online gambling Web site. Results showed that just over a quarter of players (26%) had used PlayScan. The vast majority of those who had activated PlayScan (almost 9 in 10 users) said that PlayScan was easy to use. Over half of PlayScan users (52%) said it was useful; 19% said it was not. Many features were seen as useful by online gamblers, including limit setting (70%), viewing their gambling profile (49%), self-exclusion facilities (42%), self-diagnostic problem gambling tests (46%), information and support for gambling issues (40%), and gambling profile predictions (36%). In terms of actual (as opposed to theoretical) use, over half of PlayScan users (56%) had set spending limits, 40% had taken a self-diagnostic problem gambling test, and 17% had used a self-exclusion feature.

  3. Resting and postexercise heart rate variability in professional handball players.

    PubMed

    Kayacan, Yildirim; Yildiz, Sedat

    2016-03-01

    The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (P<0.01). HR was increased with exercise (P<0.001) and was slower in handball players (P<0.01). QTc was increased with exercise (P<0.001) and was higher in handball players (P<0.001). Exercise decreased pNN50 values in both groups but LF/HF ratio increased only in sedentary subjects. In conclusion, results of the HRV parameters show that sympathovagal balance does not appear to change in handball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

  4. Veto player theory and reform making in Western Europe.

    PubMed

    Angelova, Mariyana; Bäck, Hanna; Müller, Wolfgang C; Strobl, Daniel

    2018-05-01

    Veto player theory generates predictions about governments' capacity for policy change. Due to the difficulty of identifying significant laws needed to change the policy status quo, evidence about governments' ability to change policy has been mostly provided for a limited number of reforms and single-country studies. To evaluate the predictive power of veto player theory for policy making across time, policy areas and countries, a dataset was gathered that incorporates about 5,600 important government reform measures in the areas of social, labour, economic and taxation policy undertaken in 13 Western European countries from the mid-1980s until the mid-2000s. Veto player theory is applied in a combined model with other central theoretical expectations on policy change derived from political economy (crisis-driven policy change) and partisan theory (ideology-driven policy change). Robust support is found that governments introduce more reform measures when economic conditions are poor and when the government is positioned further away from the policy status quo. No empirical support is found for predictions of veto player theory in its pure form, where no differentiation between government types is made. However, the findings provide support for the veto player theory in the special case of minimal winning cabinets, where the support of all government parties is sufficient (in contrast to minority cabinets) and necessary (in contrast to oversized cabinets) for policy change. In particular, it is found that in minimal winning cabinets the ideological distance between the extreme government parties significantly decreases the government's ability to introduce reforms. These findings improve our understanding of reform making in parliamentary democracies and highlight important issues and open questions for future applications and tests of the veto player theory.

  5. Sport specific fitness testing of elite badminton players.

    PubMed Central

    Chin, M K; Wong, A S; So, R C; Siu, O T; Steininger, K; Lo, D T

    1995-01-01

    There is a scarcity of descriptive data on the performance capacity of elite badminton players, whose fitness requirements are quite specific. The purpose of this paper is to investigate the physiological response of elite badminton players in a sport-specific fitness test. Twelve Hong Kong national badminton team players performed a field test on a badminton court. Six light bulbs were connected to a programming device causing individual bulbs to light up in a given sequence. The players were instructed to react to the flashes by running towards them, and striking shuttles mounted in the vicinity of the bulbs. Exercise intensity was controlled by altering the interval between successive lightings. A low correlation (r = 0.65) was found between the results of the field test and the rank-order list of subjects, based on an objective on-field physiological assessment and subjective ranking. This may be explained by the requirements of other factors besides physical fitness which contribute to success in elite level badminton competition. These factors may include, for example, technical skill, mental power, and aesthetic judgements on the court. Maximum mean (s.d.) heart rate data (187(8) beats.min-1) and blood lactate values (10.4(2.9) mmol.l-1) in this study showed that players were under maximal load during the field test. From the testing data, it seems reasonable to speculate that the intensity of level 3 (20 light pulses.min-1; 3.0 s.pulse-1) and level 4 (22 light pulses.min-1; 2.7 s.pulse-1) simulates the requirement of actual games energy expenditure of the Hong Kong badminton players exercising at close to their anaerobic threshold. The results also show that an estimate of fitness can be derived from measurements involving exercise closely resembling that which is specific for the sports activity in question. Improved training advice and guidance may result from such studies. PMID:8800846

  6. Extensive monitoring through multiple blood samples in professional soccer players.

    PubMed

    Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter; Storskov, Anders; Kjær, Michael; Andersen, Jesper L

    2013-05-01

    The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players and to analyze different blood parameters in relation to seasonal changes in training and match exposure. Blood samples were collected 5 times during a 6-month period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, the players were tested for body composition, V[Combining Dot Above]O2max and physical performance by the Yo-Yo intermittent endurance submax test (IE2). Multiple variations in blood parameters occurred during the observation period, including a decrease in hemoglobin and an increase in hematocrit as the competitive season progressed. Iron and transferrin were stable, whereas ferritin showed a decrease at the end of the season. The immunoglobulin A (IgA) and IgM increased in the period with basal physical training and at the end of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. The V[Combining Dot Above]O2max decreased toward the end of the season, whereas no significant changes were observed in the IE2 test. The regular blood samples from elite soccer players reveal significant changes that may be related to changes in training pattern, match exposure, or length of the match season. Especially the end of the preparation season and at the end of the competitive season seem to be time points were the blood-derived values indicate that the players are under excessive physical strain and might be more subjected to a possible overreaching-overtraining conditions. We suggest that regular analyses of blood samples could be an important initiative to optimize training adaptation, training load, and game participation, but sampling has to be regular, and a database has to be built for each individual player.

  7. Head Impact Exposure and Neurologic Function of Youth Football Players.

    PubMed

    Munce, Thayne A; Dorman, Jason C; Thompson, Paul A; Valentine, Verle D; Bergeron, Michael F

    2015-08-01

    Football players are subjected to repetitive impacts that may lead to brain injury and neurologic dysfunction. Knowledge about head impact exposure (HIE) and consequent neurologic function among youth football players is limited. This study aimed to measure and characterize HIE of youth football players throughout one season and explore associations between HIE and changes in selected clinical measures of neurologic function. Twenty-two youth football players (11-13 yr) wore helmets outfitted with a head impact telemetry (HIT) system to quantify head impact frequency, magnitude, duration, and location. Impact data were collected for each practice (27) and game (9) in a single season. Selected clinical measures of balance, oculomotor performance, reaction time, and self-reported symptoms were assessed before and after the season. The median individual head impacts per practice, per game, and throughout the entire season were 9, 12, and 252, respectively. Approximately 50% of all head impacts (6183) had a linear acceleration between 10g and 20g, but nearly 2% were greater than 80g. Overall, the head impact frequency distributions in this study population were similar in magnitude and location as in high school and collegiate football, but total impact frequency was lower. Individual changes in neurologic function were not associated with cumulative HIE. This study provides a novel examination of HIE and associations with short-term neurologic function in youth football and notably contributes to the limited HIE data currently available for this population. Whereas youth football players can experience remarkably similar head impact forces as high school players, cumulative subconcussive HIE throughout one youth football season may not be detrimental to short-term clinical measures of neurologic function.

  8. Veto player theory and reform making in Western Europe

    PubMed Central

    ANGELOVA, MARIYANA; BÄCK, HANNA; MÜLLER, WOLFGANG C.

    2017-01-01

    Abstract Veto player theory generates predictions about governments’ capacity for policy change. Due to the difficulty of identifying significant laws needed to change the policy status quo, evidence about governments’ ability to change policy has been mostly provided for a limited number of reforms and single‐country studies. To evaluate the predictive power of veto player theory for policy making across time, policy areas and countries, a dataset was gathered that incorporates about 5,600 important government reform measures in the areas of social, labour, economic and taxation policy undertaken in 13 Western European countries from the mid‐1980s until the mid‐2000s. Veto player theory is applied in a combined model with other central theoretical expectations on policy change derived from political economy (crisis‐driven policy change) and partisan theory (ideology‐driven policy change). Robust support is found that governments introduce more reform measures when economic conditions are poor and when the government is positioned further away from the policy status quo. No empirical support is found for predictions of veto player theory in its pure form, where no differentiation between government types is made. However, the findings provide support for the veto player theory in the special case of minimal winning cabinets, where the support of all government parties is sufficient (in contrast to minority cabinets) and necessary (in contrast to oversized cabinets) for policy change. In particular, it is found that in minimal winning cabinets the ideological distance between the extreme government parties significantly decreases the government's ability to introduce reforms. These findings improve our understanding of reform making in parliamentary democracies and highlight important issues and open questions for future applications and tests of the veto player theory. PMID:29695891

  9. Anthropometric and physiological characteristics of rugby union football players.

    PubMed

    Nicholas, C W

    1997-06-01

    Rugby union enjoys worldwide popularity, but there is a lack of comprehensive research into the anthropometric and physiological characteristics of its players and the demands of the game, particularly at the elite level. One of the possible explanations for this is that the sport has previously been primarily concerned with the aspects of skill related to the game, rather than the physical and physiological requirements. However, with the increased physiological demands being placed on the elite players (using the British Isles as an example), with the recent introduction of professionalism, regional championships, the World Cup and major tours, information about the demands of the game and the assessment of, and methods of improving, the anthropometric and physiological characteristics of its players, are of paramount importance. Match analysis has indicated that rugby is an interval or intermittent sport and players must be able to perform a large number of intensive efforts of 5 to 15 seconds' duration with less than 40 seconds' recovery between each bout of high intensity activity. These observations, together with the metabolic responses during the game, give some insight into its physiological demands and are a prerequisite in the development and prescription of training programmes by coaches in preparing individual players for competition. The results from studies reporting the anthropometric and physiological characteristics of rugby union players observed that these individuals had unique anthropometric and physiological attributes which depended on positional role and the playing standard. These have important implications for team selection and highlight the necessity for individualised training programmes and fitness attainment targets.

  10. Heart Rate Variability Discriminates Competitive Levels in Professional Soccer Players.

    PubMed

    Proietti, Riccardo; di Fronso, Selenia; Pereira, Lucas A; Bortoli, Laura; Robazza, Claudio; Nakamura, Fabio Y; Bertollo, Maurizio

    2017-06-01

    Heart rate variability (HRV) has been increasingly used to monitor team sports athletes. Besides the traditional time domain indices (i.e., the SD of successive RR intervals [SDNN] and the root mean square difference of successive normal RR intervals [RMSSD]), recently the use of the stress score (SS), which is an inverse function of the SD2 index derived from the Poincaré plot, and the sympathetic/parasympathetic ratio (S/PS) to monitor soccer players has been proposed. However, the reliability of these new indices and the ability of HRV to differentiate between soccer competitive levels are unknown. The aim of this study was to analyze the reliability of the different HRV-derived indices in professional soccer players during the competitive period and to compare HRV of professional soccer players from 3 teams of distinct competitive levels (i.e., Italian Second Division [2D], European League [EL], and Champions League [CL]). Fifty-four male professional soccer players from 3 different teams of 2 European countries (Italy and Germany) participated in the study. The intraclass correlation coefficient values of the HRV indices varied from 0.78 (very large) to 0.90 (near perfect). The coefficient of variation (CV) values for RMSSD and SDNN were all <5.00%, although the CV for SS was 6.13% and for S/PS, it was 21.33%. Both the CL and EL groups, assumed to be internationally qualified, presented higher lnRMSSD and lnSDNN and lower lnSS and S/PS than the 2D. Therefore, the HRV can be considered reliable in professional soccer players and is able to differentiate between international- and national-level players.

  11. High Speed Running and Sprinting Profiles of Elite Soccer Players

    PubMed Central

    Miñano-Espin, Javier; Casáis, Luis; Lago-Peñas, Carlos; Gómez-Ruano, Miguel Ángel

    2017-01-01

    Abstract Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent) were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD) = 536, External Defenders (ED) = 491, Central Midfielders (CM) = 544, External Midfielders (EM) = 233, and Forwards (F) = 278). Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France). A repeated measures analysis of variance (ANOVA) was performed for distances covered at different intensities (sprinting (>24.0 km/h) and high-speed running (21.1-24.0 km/h) and the number of sprints (21.1-24.0 km/h and >24.0 km/h) during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p < 0.01). While ED did not show differences in their physical performance, CD (p < 0.05), CM (p < 0.01), EM (p < 0.01) and F (p > 0.01) from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition. PMID:28828087

  12. In-season training periodization of professional soccer players

    PubMed Central

    Mendez-Villanueva, A; Martínez-Santos, R

    2017-01-01

    The aim of this study was to quantify the seasonal perceived respiratory and muscular training loads (i.e., sRPEres-TL and sRPEmus-TL) completed by elite-oriented young professional soccer players. Twenty-four players (20.3 ± 2.0 years) belonging to the same reserve team of a Spanish La Liga club participated in this study. Only the players that were available to train for a whole week with the team and also to play the weekly game were considered: Starters, players that participated in the match for at least 45 min and Non-Starters, players that did not participate or played less than 45 minutes in the match. The competitive period was analysed after the division into 5x6-8 week blocks and 35x1 week microcycles. Data were also analysed with respect to number of days before the immediate match. Weekly TL variation across the in-season blocks was trivial-small for both groups except between Block 2 and Block 3 (ES= moderate). Substantial TL differences (ES= small–very likely) were found between training days, the TL pattern being a progressive increase up to MD-3 followed by a decrease until MD-1. Except for the match, sRPEres-/sRPEmus-TL was very similar between Starters and Non-Starters. In summary, perceived TL across the season displayed limited variation. Coaches periodized training contents to attain the highest weekly TL 72 hours before the match to progressively unload the players between MD-3 and the match day. The data revealed that the TL arising from the weekly game was solely responsible for the observed higher weekly TL of Starters in comparison with Non-Starters. PMID:28566808

  13. Online Conferencing: Lessons Learned.

    ERIC Educational Resources Information Center

    Green, Lyndsay

    This guide summarizes lessons learned from the author's experience of organizing and moderating five non-pedagogical online conferences that use World Wide Web-based conferencing software, whether synchronous or asynchronous. Seven sections cover the following topics: (1) the pros and cons of online conferencing; (2) setting objectives; (3)…

  14. Online Higher Education Commodity

    ERIC Educational Resources Information Center

    Chau, Paule

    2010-01-01

    This article analyzes the current trend towards online education. It examines some of the reasons for the trend and the ramifications it may have on students, faculty and institutions of higher learning. The success and profitability of online programs and institutions such as the University of Phoenix has helped to make the move towards online…

  15. Inventing an Online Newspaper.

    ERIC Educational Resources Information Center

    McAdams, Melinda

    1995-01-01

    Summarizes the issues, debates, and decisions that helped to shape "The Washington Post's" online service, Digital Ink. Highlights include: differences between online and print versions of the newspaper, structure of the user interface, organization of information, content, searching and navigation, and advertising. (JKP)

  16. Master Online Teacher Competencies

    ERIC Educational Resources Information Center

    Varvel, Virgil E., Jr.

    2007-01-01

    Online education continues to flourish across the globe. As we pass from the early adopter phase into acceptance by the masses, the number of instructors taking part in online education grows. Although qualified in their field, many instructors have no education in the methods of instruction or facilitation. Those that have such training often do…

  17. Online Videoconferencing Products: Update

    ERIC Educational Resources Information Center

    Burton, Douglas; Kitchen, Tim

    2011-01-01

    Software allowing real-time online video connectivity is rapidly evolving. The ability to connect students, staff, and guest speakers instantaneously carries great benefits for the online distance education classroom. This evaluation report compares four software applications at opposite ends of the cost spectrum: "DimDim", "Elluminate VCS",…

  18. Children's Online Privacy.

    ERIC Educational Resources Information Center

    Aidman, Amy

    2000-01-01

    The first federal Internet privacy law (the Children's Online Privacy Protection Act) provides safeguards for children by regulating collection of their personal information. Unfortunately, teens are not protected. Legislation is pending to protect children from online marketers such as ZapMe! Interactive technologies require constant vigilance.…

  19. The Online Learning Academy.

    ERIC Educational Resources Information Center

    Taylor, Suzanne Liebowitz; McKay, Donald P.; Culp, Ann; Baumann, Stephen; Elinich, Karen

    This paper describes the Online Learning Academy (OLLA), a World Wide Web-based presence that supports the use of telecomputing in the classroom by: connecting teachers to each other and Internet educational resources; fostering the use of online resources and collaboration; encouraging and enabling the sharing of classroom experiences; and…

  20. Using Online Tone Generators

    ERIC Educational Resources Information Center

    Lincoln, James

    2017-01-01

    Online tone generators are free, user friendly, and can make for engaging and meaningful study of many topics in the areas of interference, waves, and the physics of music. By using a website such as OnlineToneGenerator.com, and through opening multiple windows simultaneously, students can immediately perform several experiments. In this article,…

  1. Serving the Online Learner

    ERIC Educational Resources Information Center

    Boettcher, Judith V.

    2007-01-01

    Systems and services for recruiting, advising, and support of online students have seldom been at the top of the list when planning online and distance learning programs. That is now changing: Forces pushing advising and support services into the foreground include recognition of the student learner as "customer" and the increasing…

  2. Online Learning for Teachers.

    ERIC Educational Resources Information Center

    Kesner, Rebecca J., Ed.

    2001-01-01

    This newsletter contains two articles on teacher use of educational technology. The first article, "Online Learning for Teachers," (Stephen G. Barkley) explains that online learning has the ability to multiply both the effectiveness and efficiency of traditional onsite training by eliminating the need for travel. It describes the five components…

  3. Accessible Online Learning

    ERIC Educational Resources Information Center

    Case, D. Elizabeth; Davidson, Roseanna C.

    2011-01-01

    The number of online courses offered at the postsecondary level is increasing at a rate greater than the increase in overall higher education enrollment, with approximately one of every four higher education students taking at least one course online (Allen and Seaman, 2009). In 2008, students with disabilities represented nearly 11% of all…

  4. The Online Catalog Revolution.

    ERIC Educational Resources Information Center

    Kilgour, Frederick G.

    1984-01-01

    A review of library technological development and card catalog innovations of the past century and a half precedes a discussion of online public access catalog development. Design requirements and purpose of the online catalog, access techniques and provisions, costs, and future integration are highlighted. Twenty-two references are listed. (EJS)

  5. Conducting interactive experiments online.

    PubMed

    Arechar, Antonio A; Gächter, Simon; Molleman, Lucas

    2018-01-01

    Online labor markets provide new opportunities for behavioral research, but conducting economic experiments online raises important methodological challenges. This particularly holds for interactive designs. In this paper, we provide a methodological discussion of the similarities and differences between interactive experiments conducted in the laboratory and online. To this end, we conduct a repeated public goods experiment with and without punishment using samples from the laboratory and the online platform Amazon Mechanical Turk. We chose to replicate this experiment because it is long and logistically complex. It therefore provides a good case study for discussing the methodological and practical challenges of online interactive experimentation. We find that basic behavioral patterns of cooperation and punishment in the laboratory are replicable online. The most important challenge of online interactive experiments is participant dropout. We discuss measures for reducing dropout and show that, for our case study, dropouts are exogenous to the experiment. We conclude that data quality for interactive experiments via the Internet is adequate and reliable, making online interactive experimentation a potentially valuable complement to laboratory studies.

  6. The Role of Auditory Features Within Slot-Themed Social Casino Games and Online Slot Machine Games.

    PubMed

    Bramley, Stephanie; Gainsbury, Sally M

    2015-12-01

    Over the last few years playing social casino games has become a popular entertainment activity. Social casino games are offered via social media platforms and mobile apps and resemble gambling activities. However, social casino games are not classified as gambling as they can be played for free, outcomes may not be determined by chance, and players receive no monetary payouts. Social casino games appear to be somewhat similar to online gambling activities in terms of their visual and auditory features, but to date little research has investigated the cross over between these games. This study examines the auditory features of slot-themed social casino games and online slot machine games using a case study design. An example of each game type was played on three separate occasions during which, the auditory features (i.e., music, speech, sound effects, and the absence of sound) within the games were logged. The online slot-themed game was played in demo mode. This is the first study to provide a qualitative account of the role of auditory features within a slot-themed social casino game and an online slot machine game. Our results found many similarities between how sound is utilised within the two games. Therefore the sounds within these games may serve functions including: setting the scene for gaming, creating an image, demarcating space, interacting with visual features, prompting players to act, communicating achievements to players, providing reinforcement, heightening player emotions and the gaming experience. As a result this may reduce the ability of players to make a clear distinction between these two activities, which may facilitate migration between games.

  7. Implementation of MP3 player for music therapy on hypertension.

    PubMed

    Yu, J Y; Huang, D F; Li, Y; Zhang, Y T

    2009-01-01

    Hypertension is a common clinical disease and a major risk to human health. Many clinical findings indicate that certain types of music can reduce blood pressure (BP), and music therapy is considered as an important part of anti-hypertension treatment. We integrate our former related research achievement into the new MP3 player, which can also detect the current BP value with a cuffless measurement method. According to the current BP value, the MP3 player selects certain types of music for playing in order to alleviate the hypertension of patients.

  8. THORACOLUMBAR RANGE OF MOTION IN BASEBALL PITCHERS AND POSITION PLAYERS

    PubMed Central

    Lynall, Robert; Williams, Jeffrey G.; Wong, Regan; Onuki, Takashi; Meister, Keith

    2013-01-01

    Introduction/Background: Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance. Purpose: To define the active‐assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups. Methods: Fifty‐six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active‐assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two‐tailed t tests were used to determine differences in ROM between and within the pitchers and position players. Results: The pitchers had significantly more rotation to the non‐throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non‐throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side‐to‐side rotation difference (p = .99). Conclusions: Pitchers have a greater amount of rotation ROM towards the non‐throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non‐throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non‐throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non‐throwing side trunk rotation ROM may allow such athletes to

  9. The Multi-Player Performance-Enhancing Drug Game

    PubMed Central

    Haugen, Kjetil K.; Nepusz, Tamás; Petróczi, Andrea

    2013-01-01

    This paper extends classical work on economics of doping into a multi-player game setting. Apart from being among the first papers formally formulating and analysing a multi-player doping situation, we find interesting results related to different types of Nash-equilibria (NE). Based mainly on analytic results, we claim at least two different NE structures linked to the choice of prize functions. Linear prize functions provide NEs characterised by either everyone or nobody taking drugs, while non-linear prize functions lead to qualitatively different NEs with significantly more complex predictive characteristics. PMID:23691018

  10. Prediction of Tennis Performance in Junior Elite Tennis Players

    PubMed Central

    Kramer, Tamara; Huijgen, Barbara C.H.; Elferink-Gemser, Marije T.; Visscher, Chris

    2017-01-01

    Predicting current and future tennis performance can lead to improving the development of junior tennis players. The aim of this study is to investigate whether age, maturation, or physical fitness in junior elite tennis players in U13 can explain current and future tennis performance. The value of current tennis performance for future tennis performance is also investigated. A total of 86 junior elite tennis players (boys, n = 44; girls, n = 42) U13 (aged: 12.5 ± 0.3 years), and followed to U16, took part in this study. All players were top-30 ranked on the Dutch national ranking list at U13, and top-50 at U16. Age, maturation, and physical fitness, were measured at U13. A principal component analysis was used to extract four physical components from eight tests (medicine ball throwing overhead and reverse, ball throwing, SJ, CMJas, Sprint 5 and 10 meter, and the spider test). The possible relationship of age, maturation, and the physical components; “upper body power”, “lower body power”, “speed”, and “agility” with tennis performance at U13 and U16 was analyzed. Tennis performance was measured by using the ranking position on the Dutch national ranking list at U13 and U16. Regression analyses were conducted based on correlations between variables and tennis performance for boys and girls, separately. In boys U13, positive correlations were found between upper body power and tennis performance (R2 is 25%). In girls, positive correlations between maturation and lower body power with tennis performance were found at U13. Early maturing players were associated with a better tennis performance (R2 is 15%). In girls U16, only maturation correlated with tennis performance (R2 is 13%); later-maturing girls at U13 had better tennis performances at U16. Measuring junior elite tennis players at U13 is important for monitoring their development. These measurements did not predict future tennis performance of junior elite tennis players three years later

  11. Teaching Astronomy Online

    NASA Astrophysics Data System (ADS)

    Radnofsky, Mary L.; Bobrowsky, Matthew

    This article is intended to provide an overview of the practical, pedagogical, and philosophical considerations in designing a Web-based astronomy course, and to demonstrate the educational benefits that such online courses can afford students. Because online students need to take more responsibility for their learning, faculty must make course expectations extremely clear. Online education allows for increased student participation and equal access to college by such groups as the military, the handicapped, full-time employees, and rural and senior citizens. Teaching the sciences online--especially astronomy--gives students more time to think critically about new information. This article also includes tools, checklists, and resources helpful for introducing faculty to online course development in astronomy.

  12. Online Advertising in Social Networks

    NASA Astrophysics Data System (ADS)

    Bagherjeiran, Abraham; Bhatt, Rushi P.; Parekh, Rajesh; Chaoji, Vineet

    Online social networks offer opportunities to analyze user behavior and social connectivity and leverage resulting insights for effective online advertising. This chapter focuses on the role of social network information in online display advertising.

  13. Massively multiplayer online role-playing games (MMORPG): association between its addiction, self-control and mental disorders among young people in Vietnam.

    PubMed

    Son, Dinh Thai; Yasuoka, Junko; Poudel, Krishna C; Otsuka, Keiko; Jimba, Masamine

    2013-09-01

    To explore the association between MMORPG addiction and mental health status, and between self-control ability and mental health status among young male MMORPG players in Hanoi, Vietnam. In this cross-sectional study, 10 computer game rooms were randomly selected out of 77 in five communes in Hanoi. From these game rooms, 350 MMORPG players were purposively recruited as a study group, of whom 344 completed the questionnaire. In the same five communes, 344 non-players were selected as a control group. An online game addiction scale, a self-control scale and the Vietnamese SRQ-20 were used to measure the degree of MMORPG addiction, self-control ability and level of mental disorders. MMORPG players had significantly higher mental disorders scale scores than non-players (p < .001). The strongest positive correlation was detected between MMORPG addiction scale scores and mental disorders scale scores (r = 0.730, p < .001). Self-control scale scores were negatively associated with mental disorders scale scores (r = -0.345, p < .001). The average amount of money spent on games per month, MMORPG addiction scale score and self-control scale score were considered the best predictors of a higher mental disorders scale score. Young, male MMORPG players with higher addiction scores were more likely to have higher mental disorders scale scores, and such mental status was negatively associated with the level of self-control in Hanoi, Vietnam. Closer attention should be paid to prevent mental disorders among MMORPG players.

  14. Talking Online: Reflecting on Online Communication Tools

    ERIC Educational Resources Information Center

    Greener, Susan

    2009-01-01

    Purpose: The purpose of this paper is to reflect on the value and constraints of varied online communication tools from web 2.0 to e-mail in a higher education (HE) teaching and learning context, where these tools are used to support or be the main focus of learning. Design/methodology/approach: A structured reflection is produced with the aid of…

  15. Is There Chronic Brain Damage in Retired NFL Players? Neuroradiology, Neuropsychology, and Neurology Examinations of 45 Retired Players

    PubMed Central

    Casson, Ira R.; Viano, David C.; Haacke, E. Mark; Kou, Zhifeng; LeStrange, Danielle G.

    2014-01-01

    Background: Neuropathology and surveys of retired National Football League (NFL) players suggest that chronic brain damage is a frequent result of a career in football. There is limited information on the neurological statuses of living retired players. This study aimed to fill the gap in knowledge by conducting in-depth neurological examinations of 30- to 60-year-old retired NFL players. Hypothesis: In-depth neurological examinations of 30- to 60-year-old retired players are unlikely to detect objective clinical abnormalities in the majority of subjects. Study Design: A day-long medical examination was conducted on 45 retired NFL players, including state-of-the-art magnetic resonance imaging (MRI; susceptibility weighted imaging [SWI], diffusion tensor imaging [DTI]), comprehensive neuropsychological and neurological examinations, interviews, blood tests, and APOE (apolipoprotein E) genotyping. Level of Evidence: Level 3. Methods: Participants’ histories focused on neurological and depression symptoms, exposure to football, and other factors that could affect brain function. The neurological examination included Mini-Mental State Examination (MMSE) evaluation of cognitive function and a comprehensive search for signs of dysarthria, pyramidal system dysfunction, extrapyramidal system dysfunction, and cerebellar dysfunction. The Beck Depression Inventory (BDI) and Patient Health Questionnaire (PHQ) measured depression. Neuropsychological tests included pen-and-paper and ImPACT evaluation of cognitive function. Anatomical examination SWI and DTI MRI searched for brain injuries. The results were statistically analyzed for associations with markers of exposure to football and related factors, such as body mass index (BMI), ethanol use, and APOE4 status. Results: The retired players’ ages averaged 45.6 ± 8.9 years (range, 30-60 years), and they had 6.8 ± 3.2 years (maximum, 14 years) of NFL play. They reported 6.9 ± 6.2 concussions (maximum, 25) in the NFL. The

  16. Dental injuries and the attitudes of Rugby players to mouth guards

    PubMed Central

    Upson, N.

    1982-01-01

    A survey of dental and facial injuries of 100 rugby union players are recorded, and the attitudes of the players to the wearing of different types of mouthguards are examined. Imagesp241-aFig. 1Fig. 2 PMID:6130812

  17. 37 CFR 254.2 - Definition of coin-operated phonorecord player.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-OPERATED PHONORECORD PLAYERS § 254.2 Definition of coin-operated phonorecord player. As used in this part..., currency, tokens, or other monetary units or their equivalent; (b) Is located in an establishment making no...

  18. The incidence, prevalence, severity, mechanism and body region of injury in elite junior Australian football players: A prospective cohort study over one season.

    PubMed

    Lathlean, Timothy J H; Gastin, Paul B; Newstead, Stuart V; Finch, Caroline F

    2018-03-14

    To describe the incidence, prevalence, severity, mechanism and body region of injuries in elite junior Australian football (AF) players over one competitive season in order to help inform injury prevention interventions. Prospective cohort, data collected during the 2014 playing season. Player and staff-reported injuries sustained by 562 players from an under-18 state league were entered into an online sports injury surveillance system. An injury was recorded if it led to a missed training session or match. Injury incidence was calculated as the number of injuries per 1000h of training and competition. Injury severity was defined by the number of days players missed training or competition. Injury mechanism was identified as either contact, non-contact or overuse. There were 1192 football-related injuries sustained during the season; the majority (n=1041, 87.3%) were new, occurred during competition (n=954, 86%) and led to 4-7 missed days in severity (n=429, 46%). Injury incidence was 37.2 injuries per 1000h of exposure. Over half of injuries were contact in mechanism (n=355, 51%). Most injuries were to the lower limb (n=720, 60%), with the thigh representing the highest proportion of these. This study provides key information as to the aetiology of injury in this level of competition and provides a stronger foundation from which injury prevention studies could be carried out. Future research is well-placed to develop an understanding of the injury risk factors in the elite junior cohort, whilst also reducing injury risk once players transition to the AFL. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  19. Effect of game format on heart rate, activity profile, and player involvement in elite and recreational youth players.

    PubMed

    Randers, M B; Andersen, T B; Rasmussen, L S; Larsen, M N; Krustrup, P

    2014-08-01

    The purpose of this study was to evaluate activity profile, aerobic load, and player involvement in two game formats of recreational and elite youth football for two age groups. A total of 152 youth players participated, with 45 U10 players playing 5v5 and 8v8 games, and 41 U13 players playing 8v8 and 11v11 (20 min) games. Activity profile, heart rate (HR), and technical actions were measured during all games using 10 Hz GPS, video filming, and HR monitors. For U10, no difference was found in total distance covered (1754 ± 237 vs 1771 ± 314 m, P = 0.650, d = 0.06), whereas mean HR (174 ± 10 vs 168 ± 12 bpm, P = 0.001, d = 0.59) and number of technical actions (65.1 ± 24.0 vs 36.9 ± 20.4, P    0.001, d = 1.27) were higher in 5v5 than in 8v8. For U13, lower total distance covered (1821 ± 325 vs 2038 ± 328 m, P < 0.001, d = 0.66) and higher number of technical actions (36.2 ± 14.9 vs 26.9 ± 14.1, P < 0.001, d = 0.64) were observed in 8v8 than in 11v11, with no difference in mean HR (170 ± 10 vs 171 ± 10 bpm, P = 0.679, d = 0.10). In conclusion, HR is high in youth football matches irrespective of the level of play and the game format. Playing with fewer players on smaller pitches results in minor changes to the physical loading but elevates the technical involvement of youth players both at elite level and recreational level. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Biomechanical and functional indicators in male semiprofessional soccer players with increased hip alpha angles vs. amateur soccer players.

    PubMed

    Lahner, Matthias; von Schulze Pellengahr, Christoph; Walter, Philipp Alexander; Lukas, Carsten; Falarzik, Andreas; Daniilidis, Kiriakos; von Engelhardt, Lars Victor; Abraham, Christoph; Hennig, Ewald M; Hagen, Marco

    2014-03-16

    Femoroacetabular impingement (FAI) is predominant in young male athletes, but not much is known about gait differences in cases of increased hip alpha angles. In our study, the hip alpha angle of Nötzli of soccer players was quantified on the basis of magnetic resonance imaging (MRI) with axial oblique sequences. The aim of the current study was to compare the rearfoot motion and plantar pressure in male semiprofessional soccer players with increased alpha angles to age-matched amateur soccer players. In a prospective analysis, male semiprofessional and amateur soccer players had an MRI of the right hip to measure the alpha angle of Nötzli. In a biomechanical laboratory setting, 14 of these participants in each group ran in two shoe conditions. Simultaneously in-shoe pressure distribution, tibial acceleration, and rearfoot motion measurements of the right foot were performed. In the semiprofessional soccer group, the mean value of the alpha angle of group was 55.1 ± 6.58° (range 43.2-76.6°) and 51.6 ± 4.43° (range 41.9-58.8°) in the amateur group. In both shoe conditions, we found a significant difference between the two groups concerning the ground reaction forces, tibial acceleration, rearfoot motion and plantar pressure parameters (P < 0.01, P < 0.05, P = 0.04). Maximum rearfoot motion is about 22% lower in the semiprofessional group compared to the amateur group in both shoe conditions. This study confirmed that semiprofessional soccer players with increased alpha angles showed differences in gait kinematics compared to the amateur group. These findings support the need for a screening program for competitive soccer players. In cases of a conspicuous gait analysis and symptomatic hip pain, FAI must be ruled out by further diagnostic tests.