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Sample records for players showed higher

  1. Video game players show higher performance but no difference in speed of attention shifts.

    Science.gov (United States)

    Mack, David J; Wiesmann, Helene; Ilg, Uwe J

    2016-09-01

    Video games have become both a widespread leisure activity and a substantial field of research. In a variety of tasks, video game players (VGPs) perform better than non-video game players (NVGPs). This difference is most likely explained by an alteration of the basic mechanisms underlying visuospatial attention. More specifically, the present study hypothesizes that VGPs are able to shift attention faster than NVGPs. Such alterations in attention cannot be disentangled from changes in stimulus-response mappings in reaction time based measurements. Therefore, we used a spatial cueing task with varying cue lead times (CLTs) to investigate the speed of covert attention shifts of 98 male participants divided into 36 NVGPs and 62 VGPs based on their weekly gaming time. VGPs exhibited higher peak and mean performance than NVGPs. However, we did not find any differences in the speed of covert attention shifts as measured by the CLT needed to achieve peak performance. Thus, our results clearly rule out faster stimulus-response mappings as an explanation for the higher performance of VGPs in line with previous studies. More importantly, our data do not support the notion of faster attention shifts in VGPs as another possible explanation.

  2. Nearly All Autopsied NFL Players Show Trauma-Linked Brain Disease

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    ... gov/news/fullstory_167405.html Nearly All Autopsied NFL Players Show Trauma-Linked Brain Disease No position ... 2017 (HealthDay News) -- Ninety-nine percent of former NFL players who donated their brain to science turned ...

  3. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury.

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    Røksund, Ola D; Kristoffersen, Morten; Bogen, Bård E; Wisnes, Alexander; Engeseth, Merete S; Nilsen, Ann-Kristin; Iversen, Vegard V; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

  4. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

    Science.gov (United States)

    Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

  5. Brain regions concerned with the identification of deceptive soccer moves by higher-skilled and lower-skilled players

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    Michael eWright

    2013-12-01

    Full Text Available Expert soccer players are able to utilize their opponents’ early body kinematics to predict the direction in which the opponent will move. We have previously demonstrated enhanced fMRI activation in experts in the motor components of an action observation network (AON during sports anticipation tasks. Soccer players often need to prevent opponents from successfully predicting their line of attack, and consequently may try to deceive them; for example, by performing a step-over. We examined how AON activations and expertise effects are modified by the presence of deception. Three groups of participants; higher-skilled males, lower-skilled males and lower-skilled females, viewed video clips in point-light format, from a defender’s perspective, of a player approaching and turning with the ball. The observer’s task in the scanner was to determine whether the move was normal or deceptive (involving a step-over, while whole-brain functional images were acquired. In a second counterbalanced block with identical stimuli the task was to predict the direction of the ball. Activations of AON for identification of deception overlapped with activations from the direction identification task. Higher-skilled players showed significantly greater activation than lower-skilled players in a subset of AON areas; and lower-skilled males in turn showed greater activation than lower-skilled females, but females showed more activation in visual cortex. Activation was greater for deception identification than for direction identification in dorsolateral prefrontal cortex, medial frontal cortex, anterior insula, cingulate gyrus, and premotor cortex. Conversely, greater activation for direction than deception identification was found in anterior cingulate cortex and caudate nucleus. Results are consistent with the view that explicit identification of deceptive moves entails cognitive effort and also activates limbic structures associated with social cognition and

  6. A Study of Pacific Islander Scholarship Football Players and Their Institutional Experience in Higher Education

    Science.gov (United States)

    Morita, Monica K.

    2013-01-01

    This study applies the theories of social and cultural capital and introduces athletic capital in order to gain an understanding of Polynesian scholarship football players and their experiences at an institution of higher education. Additionally, theories of student identity development and student-athlete development are also utilized to gain a…

  7. A Study of Pacific Islander Scholarship Football Players and Their Institutional Experience in Higher Education

    Science.gov (United States)

    Morita, Monica K.

    2013-01-01

    This study applies the theories of social and cultural capital and introduces athletic capital in order to gain an understanding of Polynesian scholarship football players and their experiences at an institution of higher education. Additionally, theories of student identity development and student-athlete development are also utilized to gain a…

  8. Brain morphometry shows effects of long-term musical practice in middle-aged keyboard players

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    Hanna eGärtner

    2013-09-01

    Full Text Available To what extent does musical practice change the structure of the brain? In order to understand how long-lasting musical training changes brain structure, 20 male right-handed, middle-aged professional musicians and 19 matched controls were investigated. Among the musicians, 13 were pianists or organists with intensive practice regimes. The others were either music teachers at schools or string instrumentalists, who had studied the piano at least as a subsidiary subject, and practiced less intensively. The study was based on T1-weighted MR images, which were analyzed using Deformation Field Morphometry. Cytoarchitectonic probabilistic maps of cortical areas and subcortical nuclei as well as myeloarchitectonic maps of fiber tracts were used as regions of interest to compare volume differences in the brains of musicians and controls. In addition, maps of voxel-wise volume differences were computed and analyzed.Musicians showed a significantly better symmetric motor performance as well as a greater capability of controlling hand independence than controls. Structural MRI-data revealed significant volumetric differences between the brains of keyboard players, who practiced intensively and controls in right sensorimotor areas and the corticospinal tract as well as in the entorhinal cortex and the left superior parietal lobule. Moreover, they showed also larger volumes in a comparable set of regions than the less intensively practicing musicians. The structural changes in the sensory and motor systems correspond well to the behavioral results, and can be interpreted in terms of plasticity as a result of intensive motor training. Areas of the superior parietal lobule and the entorhinal cortex might be enlarged in musicians due to their special skills in sight-playing and memorizing of scores. In conclusion, intensive and specific musical training seems to have an impact on brain structure, not only during the sensitive period of childhood but throughout

  9. Brain morphometry shows effects of long-term musical practice in middle-aged keyboard players.

    Science.gov (United States)

    Gärtner, H; Minnerop, M; Pieperhoff, P; Schleicher, A; Zilles, K; Altenmüller, E; Amunts, K

    2013-01-01

    To what extent does musical practice change the structure of the brain? In order to understand how long-lasting musical training changes brain structure, 20 male right-handed, middle-aged professional musicians and 19 matched controls were investigated. Among the musicians, 13 were pianists or organists with intensive practice regimes. The others were either music teachers at schools or string instrumentalists, who had studied the piano at least as a subsidiary subject, and practiced less intensively. The study was based on T1-weighted MR images, which were analyzed using deformation-based morphometry. Cytoarchitectonic probabilistic maps of cortical areas and subcortical nuclei as well as myeloarchitectonic maps of fiber tracts were used as regions of interest to compare volume differences in the brains of musicians and controls. In addition, maps of voxel-wise volume differences were computed and analyzed. Musicians showed a significantly better symmetric motor performance as well as a greater capability of controlling hand independence than controls. Structural MRI-data revealed significant volumetric differences between the brains of keyboard players, who practiced intensively and controls in right sensorimotor areas and the corticospinal tract as well as in the entorhinal cortex and the left superior parietal lobule. Moreover, they showed also larger volumes in a comparable set of regions than the less intensively practicing musicians. The structural changes in the sensory and motor systems correspond well to the behavioral results, and can be interpreted in terms of plasticity as a result of intensive motor training. Areas of the superior parietal lobule and the entorhinal cortex might be enlarged in musicians due to their special skills in sight-playing and memorizing of scores. In conclusion, intensive and specific musical training seems to have an impact on brain structure, not only during the sensitive period of childhood but throughout life.

  10. Inconsistent handers show higher psychopathy than consistent handers.

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    Shobe, Elizabeth; Desimone, Kailey

    2016-01-01

    Three hundred and forty-two university students completed the Short Dark Triad (SD3) and the Edinburgh Handedness Inventory (EHI). Inconsistent handers showed higher psychopathy scores than consistent handers, and no handedness differences were observed for narcissism or Machiavellianism. Participants were further subdivided by quartile into low, moderately low, moderately high, and high psychopathy groups (non-clinical). Absolute EHI scores were equally distributed among low and moderate groups, but were significantly lower for the high psychopathy group. These findings suggest that inconsistent handedness is only associated with the upper quartile of psychopathy scores. Also, males showed significantly higher psychopathy scores than females, and the ratio of male to female inconsistent handers decreased as psychopathy score increased. No gender × handedness interaction indicated that both female and male inconsistent handers have higher psychopathy scores than consistent handers. Although significant, the effects were small and 99.6% of participants were not in the range of a potential clinical diagnosis. The reader, therefore, is strongly cautioned against equating inconsistent handedness with psychopathy.

  11. The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

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    Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

    2011-06-01

    The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

  12. Soccer small-sided games in young players: rule modification to induce higher physiological responses

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    J Halouani

    2017-04-01

    Full Text Available The aim of this study was to identify the physiological responses of 3 forms of players’ numbers during two different games rules of small-sided games (SSG: stop-ball vs. small-goals rules. Eighteen youth amateur soccer players (age 13.5±0.7 years; height 168.9±6.1cm; body mass 63.1±7.7 kg participated in this study and performed 3 SSGs with varying players’ number (2vs.2; 3vs.3 and 4vs.4: stop-ball SSG (SB-SSG vs. small-goals SSG (SG-SSG in a randomized and counter-balanced order on a constant pitch dimension (20×25m. The players performed 4×4 min SSG with 2-min of passive recovery in-between. Heart rate (HR, (expressed in bpm and % HRmax, lactate ([La-], and rating of perceived exertion (RPE were collected during each session. SB-SSG induced the higher HR values in comparison with the SG-SSG for the 3 game formats (2vs.2; 3vs.3 and 4vs.4. Also, compared with SG-SSG, SB-SSG induced the higher HR values during 2vs.2 compared with 4vs.4 games rules (178 vs. 174 and 175 vs. 171 bpm, respectively. However, the SB-SSG was more intense compared with SG-SSG in the 2 vs. 2 game rule compared with the two others (3 vs.3 and 4 vs. 4 for [La-] and RPE (7.58 vs. 7; 7.25 vs. 6.75 and 6.5 vs. 6.16 mmol ∙ L-1, and 7.75 vs. 7.33; 7.41 vs. 7.08 and 7.16 vs. 6.83, respectively. Therefore, the use of 2 vs. 2 and 3 vs. 3 SSG with SB-SSG seems to represent an alternative to coaches to increase cardiovascular and metabolic demands in youth soccer players.

  13. Semi-Professional Rugby League Players have Higher Concussion Risk than Professional or Amateur Participants: A Pooled Analysis.

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    King, Doug; Hume, Patria; Gissane, Conor; Clark, Trevor

    2017-02-01

    A combined estimate of injuries within a specific sport through pooled analysis provides more precise evidence and meaningful information about the sport, whilst controlling for between-study variation due to individual sub-cohort characteristics. The objective of this analysis was to review all published rugby league studies reporting injuries from match and training participation and report the pooled data estimates for rugby league concussion injury epidemiology. A systematic literature analysis of concussion in rugby league was performed on published studies from January 1990 to October 2015. Data were extracted and pooled from 25 studies that reported the number and incidence of concussions in rugby league match and training activities. Amateur rugby league players had the highest incidence of concussive injuries in match activities (19.1 per 1000 match hours) while semi-professional players had the highest incidence of concussive injuries in training activities (3.1 per 1000 training hours). This pooled analysis showed that, during match participation activities, amateur rugby league participants had a higher reported concussion injury rate than professional and semi-professional participants. Semi-professional participants had nearly a threefold greater concussion injury risk than amateur rugby league participants during match participation. They also had nearly a 600-fold greater concussion injury risk than professional rugby league participants during training participation.

  14. Orienting Recovery as Predictor of Higher Emotional Regulation in Soccer Players

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    Srilekha Saha

    2016-01-01

    Full Text Available Purpose of the present study was to extrapolate intricate relationships between autonomic indices of emotionality in predicting changes in transient as well as dispositional emotionality. Performance excellence in sports and games, particularly in soccer has been referred to as resultant of mental toughness or more specifically the aspect of emotional flexibility and hardiness of the athlete. One hundred thirty five high-achiever young-adult male competitive soccer players, who were residents of Kota Bharu region volunteered as participants. All of them were subjected to evaluation of inner psychobiological status (decomposed indices of phasic skin conductance activity – viz. orienting recovery time; rise time and skin conductance adaptation levels; assessment of projective analyses of unconscious core of emotionality (employing Rorschach Ink-Blot Test in the form of evaluation indices of impulsivity, irritability, integrity. Results however revealed corroborative relationships between psychobiological autonomic indices in predicting differential aspects of inner core emotionality. Multiple linear regression analyses were done to identify differential possibilities of direct, inverse, moderating and supportive relationships between decomposition indices of autonomic orienting activity related to cognitive-affective and affective-motivational aspects of sports behaviour. Analyses of autonomic activation and arousal modulation and various indices habituation paradigm indices were found as significant predictors of changes in dispositional emotional constellation observed in the athletes. Orienting latency was observed as the most significant contributor in influencing recovery from autonomic arousal (orienting recovery in predicting changes in emotional hardiness as well as in flexibility.

  15. Carbon nanotube fiber microelectrodes show a higher resistance to dopamine fouling.

    Science.gov (United States)

    Harreither, Wolfgang; Trouillon, Raphaël; Poulin, Philippe; Neri, Wilfrid; Ewing, Andrew G; Safina, Gulnara

    2013-08-06

    We have compared the properties and resistance to DA fouling of a carbon nanotube fiber (CNTF) microelectrode to a traditional carbon fiber (CF) microelectrode. These two materials show comparable electrochemical activities for outer-sphere and inner-sphere redox reactions. Although the CNTF might have a higher intrinsic RC constant, thus limiting its high-frequency behavior, the CNTF shows a significantly higher durability than the CF in terms of electrode stability. During constant oxidation of 100 μM DA, the signal measured by the CNTF microelectrode shows a 2-h window over which no decrease in current is observed. Under the same conditions, the current obtained at the CF microelectrode decreases by almost 50%. A model of the fouling process, assuming the formation of growing patches of insulator on the surface, has been compared to the data. This model is found to be in good agreement with our results and indicates a growth rate of the patches in the 0.1-2 nm s(-1) range.

  16. PCOS women show significantly higher homocysteine level, independent to glucose and E2 level

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    Eskandari, Zahra; Sadrkhanlou, Rajab-Ali; Nejati, Vahid; Tizro, Gholamreza

    2016-01-01

    Background: It is reasonable to think that some biochemical characteristics of follicular fluid (FF) surrounding the oocyte may play a critical role in determining the quality of oocyte and the subsequent potential needed to achieve fertilization and embryo development. Objective: This study was carried out to evaluate the levels of FF homocysteine (Hcy) in IVF candidate polycystic ovary syndrome (PCOS) women and any relationships with FF glucose and estradiol (E2) levels. Materials and Methods: In this case control study which was performed in Dr. Tizro Day Care and IVF Center 70 infertile patients were enrolled in two groups: comprising 35 PCOS and 35 non PCOS women. Long protocol was performed for all patients. FF Hcy, glucose and E2 levels were analyzed at the time of oocyte retrieval. Results: It was observed that FF Hcy level was significantly higher in PCOS patients compared with non PCOSs (p<0.01). Observations demonstrated that in PCOS group, the Hcy level increased independent to E2, glucose levels, BMI and age, while the PCOS group showed significantly higher BMI compared with non-PCOS group (p=0.03). However, no significant differences were revealed between groups for FF glucose and E2 levels. Conclusion: Present data showed that although FF glucose and E2 levels were constant in PCOS and non PCOS patients, but the FF Hcy levels in PCOS were significantly increased (p=0.01). PMID:27679823

  17. Fibroblasts maintained in 3 dimensions show a better differentiation state and higher sensitivity to estrogens

    Energy Technology Data Exchange (ETDEWEB)

    Montani, Claudia [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Steimberg, Nathalie; Boniotti, Jennifer [Laboratory of Tissue Engineering, Anatomy and Physiopathology Unit, Department of Clinical and Experimental Sciences, School of Medicine, University of Brescia (Italy); Biasiotto, Giorgio; Zanella, Isabella [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Department of Molecular and Translational Medicine, University of Brescia, Brescia (Italy); Diafera, Giuseppe [Integrated Systems Engineering (ISE), Milan (Italy); Biunno, Ida [IRGB-CNR, Milan (Italy); IRCCS-Multimedica, Milan (Italy); Caimi, Luigi [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Department of Molecular and Translational Medicine, University of Brescia, Brescia (Italy); Mazzoleni, Giovanna [Laboratory of Tissue Engineering, Anatomy and Physiopathology Unit, Department of Clinical and Experimental Sciences, School of Medicine, University of Brescia (Italy); Di Lorenzo, Diego, E-mail: diego.dilorenzo@yahoo.it [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy)

    2014-11-01

    Cell differentiation and response to hormonal signals were studied in a 3D environment on an in-house generated mouse fibroblast cell line expressing a reporter gene under the control of estrogen responsive sequences (EREs). 3D cell culture conditions were obtained in a Rotary Cell Culture System; (RCCS™), a microgravity based bioreactor that promotes the aggregation of cells into multicellular spheroids (MCS). In this bioreactor the cells maintained a better differentiated phenotype and more closely resembled in vivo tissue. The RCCS™ cultured fibroblasts showed higher expression of genes regulating cell assembly, differentiation and hormonal functions. Microarray analysis showed that genes related to cell cycle, proliferation, cytoskeleton, migration, adhesion and motility were all down-regulated in 3D as compared to 2D conditions, as well as oncogene expression and inflammatory cytokines. Controlled remodeling of ECM, which is an essential aspect of cell organization, homeostasis and tissue was affected by the culture method as assessed by immunolocalization of β-tubulin. Markers of cell organization, homeostasis and tissue repair, metalloproteinase 2 (MMP2) and its physiological inhibitor (TIMP4) changed expression in association with the relative formation of cell aggregates. The fibroblasts cultured in the RCCS™ maintain a better responsiveness to estrogens, measured as expression of ERα and regulation of an ERE-dependent reporter and of the endogenous target genes CBP, Rarb, MMP1 and Dbp. Our data highlight the interest of this 3D culture model for its potential application in the field of cell response to hormonal signals and the pharmaco-toxicological analyses of chemicals and natural molecules endowed of estrogenic potential. - Highlights: • We here characterized the first cell line derived from an estrogen reporter mouse. • In the RCCS cells express an immortalized behavior but not a transformed phenotype. • The RCCS provides a system for

  18. Features of the training process of handball players of higher qualification between rounds in the competitive period

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    Tyshchenko V.A.

    2015-01-01

    Full Text Available Purpose : the technology of preparation of athletes in accordance with the requirements of the system approach. Team management methodology disclosed in terms of the training process in the competitive period between rounds of the regular championship of Ukraine. Material : the experiment involved 85 athletes aged 18-32 years. Results : The recommended during pilot training to perform technical and tactical actions in lockstep future games. Testing and modeling training - at a more complete simulation of conditions of competition. Shock training to perform with significant excess volume and intensity. Shock-modeling training - close to a match where the simulated conditions and confounding factor. The most efficient and effective indicators to consider: the number of substitutions in one match - 8-12 times; residence time player on the court - 12-15 minutes; preferred time of travel players during replacement - 3-5 minutes; heart rate after a rest - 100-120 beats per minute. Conclusions : The developed model microcycle training process handball players between rounds of the Championship of Ukraine.

  19. Show Me the Money! Why Higher Ed Should Help K-12 Do Economic Impact Studies

    Science.gov (United States)

    Alam, Nadia

    2010-01-01

    In education, economic impact studies have been largely the product of higher education institutions. Colleges and universities have recognized that they can cultivate public, political and financial support by effectively demonstrating their high return-on-investment value. For more than a decade, all types of higher education institutions have…

  20. The drug target genes show higher evolutionary conservation than non-target genes.

    Science.gov (United States)

    Lv, Wenhua; Xu, Yongdeng; Guo, Yiying; Yu, Ziqi; Feng, Guanglong; Liu, Panpan; Luan, Meiwei; Zhu, Hongjie; Liu, Guiyou; Zhang, Mingming; Lv, Hongchao; Duan, Lian; Shang, Zhenwei; Li, Jin; Jiang, Yongshuai; Zhang, Ruijie

    2016-01-26

    Although evidence indicates that drug target genes share some common evolutionary features, there have been few studies analyzing evolutionary features of drug targets from an overall level. Therefore, we conducted an analysis which aimed to investigate the evolutionary characteristics of drug target genes. We compared the evolutionary conservation between human drug target genes and non-target genes by combining both the evolutionary features and network topological properties in human protein-protein interaction network. The evolution rate, conservation score and the percentage of orthologous genes of 21 species were included in our study. Meanwhile, four topological features including the average shortest path length, betweenness centrality, clustering coefficient and degree were considered for comparison analysis. Then we got four results as following: compared with non-drug target genes, 1) drug target genes had lower evolutionary rates; 2) drug target genes had higher conservation scores; 3) drug target genes had higher percentages of orthologous genes and 4) drug target genes had a tighter network structure including higher degrees, betweenness centrality, clustering coefficients and lower average shortest path lengths. These results demonstrate that drug target genes are more evolutionarily conserved than non-drug target genes. We hope that our study will provide valuable information for other researchers who are interested in evolutionary conservation of drug targets.

  1. NaFeEDTA Fortified Soy Sauce Showed Higher Iron Absorption Rate in Chinese Females

    Institute of Scientific and Technical Information of China (English)

    JUN-SHENG HUO; XIAO-GUANG YANG; JIAN-HUA PIAO; JUN-QUAN GAO; HONG MIAO; Bo YU; CHENG-QIAN LU; JUN-SHI CHEN

    2007-01-01

    Objective NaFeEDTA was considered as a promising iron fortificant for controlling iron deficiency anemia. Soy sauce is a suitable food carrier for iron fortification and is a popular condiment in China. Iron absorption rates of NaFeEDTA and FeSO4were observed and compared in adult female subjects. Methods The stable isotope tracer method was used in Chinese females consuming a typical Chinese diet. Ten healthy young Chinese women were selected as subjects in the 15-day study. A plant-based diet was used based on the dietary pattern of adult women in the 1992 National Nutrition Survey. Six milligram of54Fe in 54FeSO4 soy sauce and 3 mg 58Fe in Na58FeEDTA soy sauce were given to the same subjects in two days. Food samples and fecal samples were collected and analyzed. Results Iron absorption rates of NaFeEDTA and FeSO4 were 10.51%±2.83and 4.73%±2.15 respectively. The 58Fe (NaFeEDTA) absorption was significantly higher than that of 54Fe (FeSO4) (P<0.01).The iron absorption rate from NaFeEDTA was 1.2 times higher than that from FeSO4 in Chinese adult women consuming a typical Chinese diet. Conclusion The higher absorption rate of NaFeEDTA suggested that NaFeEDTA would be a better iron fortificant used in soy sauce for the controlling of iron deficiency anemia in China.

  2. Speed versus endurance tradeoff in plants: Leaves with higher photosynthetic rates show stronger seasonal declines

    Science.gov (United States)

    Zhang, Yong-Jiang; Sack, Lawren; Cao, Kun-Fang; Wei, Xue-Mei; Li, Nan

    2017-01-01

    We tested for a tradeoff across species between plant maximum photosynthetic rate and the ability to maintain photosynthesis under adverse conditions in the unfavorable season. Such a trade-off would be consistent with the observed trade-off between maximum speed and endurance in athletes and some animals that has been explained by cost-benefit theory. This trend would have importance for the general understanding of leaf design, and would simplify models of annual leaf carbon relations. We tested for such a trade-off using a database analysis across vascular plants and using an experimental approach for 29 cycad species, representing an ancient plant lineage with diversified evergreen leaves. In both tests, a higher photosynthetic rate per mass or per area in the favorable season was associated with a stronger absolute or percent decline in the unfavorable season. We resolved a possible mechanism based on biomechanics and nitrogen allocation; cycads with high leaf toughness (leaf mass per area) and higher investment in leaf construction than in physiological function (C/N ratio) tended to have lower warm season photosynthesis but less depression in the cool season. We propose that this trade-off, consistent with cost-benefit theory, represents a significant physio-phenological constraint on the diversity and seasonal dynamics of photosynthetic rate. PMID:28186201

  3. Sahara honey shows higher potency against Pseudomonas aeruginosa compared to north Algerian types of honey.

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    Boukraa, Laid; Niar, Abdellatif

    2007-12-01

    Six varieties of honey from different regions in Algeria were used to determine their potency against Pseudomonas aeruginosa. Four varieties originated from northern Algeria, and two from the Sahara. Three types of media were used. On nutrient agar the minimum inhibitory concentration (MIC) of the four northern varieties ranged between 30% (vol/vol) and 31% (vol/vol), while the MIC of the Sahara varieties was 11% (vol/vol) and 14% (vol/vol). On King A agar the MIC of the four northern varieties ranged from 25% (vol/vol) to 31% (vol/vol), whereas the MIC of the two varieties of Sahara honey was 12% (vol/vol) and 15% (vol/vol). On nutrient broth the MIC of the northern varieties ranged from 10% (vol/vol) to 21% (vol/vol), whereas the MIC of the two varieties of Sahara honey was 9% (vol/vol). The botanic flora of Sahara is known in Algeria for its medicinal uses, and thus the higher potency of the Sahara honey is most probably due to antibacterial substances in its plant derivates. These findings suggest that Sahara honey could be used for managing wounds and burns, which are mostly infected by P. aeruginosa.

  4. Transparent-cap-fitted colonoscopy shows higher performance with cecal intubation time in difficult cases

    Institute of Scientific and Technical Information of China (English)

    Hyung Hun Kim; Seun Ja Park; Moo In Park; Won Moor; Sung Eun Kim

    2012-01-01

    AIM:To investigate the efficacy of cap-fitted colonoscopy (CFC) with regard to cecal intubation time.METHODS:Two hundred and ninety-five patients undergoing screening colonoscopy at Gospel Hospital,Kosin University College of Medicine were enrolled in this randomized controlled trial between January and December 2010.Colonoscopies were conducted by a single endoscopist.Patient characteristics including age,sex,body mass index,history of abdominal surgery,quality of preparation,and the presence of diverticulosis were recorded.RESULTS:One hundred and fifty patients were allocated into a CFC group and 145 into a non-CFC (NCF)group.Cecal intubations were achieved in all patients.Cecal intubation time in the CFC group was significantly shorter than in the NCF group for specific conditions:age ≥ 60 years,prior abdominal surgery,and poor bowel preparation.The number of detected adenomas was higher in the CFC group than in the NCF group (P =0.040).CONCLUSION:CFC facilitated shortening of the cecal intubation time in difficult cases,and was more sensitive for detecting adenomas than was NCF.

  5. Breastfeeding Shows a Protective Trend toward Adolescents with Higher Abdominal Adiposity

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    Julien Rousseaux

    2014-10-01

    Full Text Available Objective: The question of whether breastfeeding has a protective effect against the development of overweight or obesity later in life remains controversial, especially during adolescence. The objective was to assess the relationship between breastfeeding and adolescents' body composition. Methods: The HELENA study is a cross-sectional study involving 3,528 adolescents from 10 European cities. The outcome measures were body weight and height, subscapular skinfolds as well as waist circumferences. Breastfeeding, smoking status, and parental socioeconomic status were assessed by self-administered questionnaires. Dietary intake was recorded using two 24-hour recall surveys. Two adjustment approaches were used: i covariance analysis adjusted for confounding factors (propensity score adjustment and ii multivariate quantile regression. Results: After adjustment, no significant associations were observed between breastfeeding and body composition parameters (BMI Z-score; sum of skinfolds; waist-to-height ratio. An adjusted quantile regression analysis showed a non-significant trend for a protective effect of breastfeeding toward the highest percentiles of adiposity in boys but not in girls. This is of particular interest with respect to the superiority of the waist-to-height ratio over waist circumference and BMI for detecting cardiometabolic risk factors. Conclusion: This first European study, including a large set of factors influencing adolescents' body composition, showed a non-significant trend toward a protective effect of breastfeeding on highest percentiles of adolescent's abdominal adiposity.

  6. Game Performance Evaluation in Male Goalball Players

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    Molik Bartosz

    2015-12-01

    Full Text Available 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.

  7. Sex-specific differences in injury types among basketball players

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    Ito E

    2014-12-01

    Full Text Available Eri Ito, Jun Iwamoto, Koichiro Azuma, Hideo MatsumotoInstitute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, JapanAbstract: The purpose of the present study was to investigate sex-specific differences in injury types among basketball players. According to our database, during the 20-year period between October 1991 and June 2011, 1,219 basketball players (640 males and 579 females consulted our sports medicine clinic; in total, 1,414 injuries in basketball players (729 injuries in males and 685 injuries in females were recorded. The mean age of patients was 19.6 years. The most common injury site was the knee, followed by the foot and ankle, lower back, and upper extremities. There was a higher proportion of female players presenting with a knee injury, compared with male players (50.4% vs 41.7%, and a lower proportion of female players presenting with an upper extremity injury (5.1% vs 9.7%. The proportion of anterior cruciate ligament injury in the 10–19-year-old age group was higher among female players than among male players (45.9% vs 22.1%, while the proportions of Osgood–Schlatter disease in the 10–19-year-old age group and jumper's knee (patellar and femoral tendinopathy in the 20–29-year-old age group were higher among male players than among female players (12.5% vs 1.8% and 14.6% vs 3.7%, respectively. However, the proportions of other injuries did not differ significantly between male and female players. The present observational study, which was performed using a retrospective case-series design, showed the existence of sex-specific differences in knee injuries sustained while participating in basketball.Keywords: sports injury, sex, anterior cruciate ligament injury, Osgood–Schlatter disease, basketball

  8. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  9. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  10. The invasive wetland plant Alternanthera philoxeroides shows a higher tolerance to waterlogging than its native Congener Alternanthera sessilis.

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    Yue Chen

    Full Text Available Plant invasion is one of the major threats to natural ecosystems. Phenotypic plasticity is considered to be important for promoting plant invasiveness. High tolerance of stress can also increase survival of invasive plants in adverse habitats. Limited growth and conservation of carbohydrate are considered to increase tolerance of flooding in plants. However, few studies have examined whether invasive species shows a higher phenotypic plasticity in response to waterlogging or a higher tolerance of waterlogging (lower plasticity than native species. We conducted a greenhouse experiment to compare the growth and morphological and physiological responses to waterlogging of the invasive, clonal, wetland species Alternanthera philoxeroides with those of its co-occurring, native, congeneric, clonal species Alternanthera sessilis. Plants of A. philoxeroides and A. sessilis were subjected to three treatments (control, 0 and 60 cm waterlogging. Both A. philoxeroides and A. sessilis survived all treatments. Overall growth was lower in A. philoxeroides than in A. sessilis, but waterlogging negatively affected the growth of A. philoxeroides less strongly than that of A. sessilis. Alternanthera philoxeroides thus showed less sensitivity of growth traits (lower plasticity and higher waterlogging tolerance. Moreover, the photosynthetic capacity of A. philoxeroides was higher than that of A. sessilis during waterlogging. Alternanthera philoxeroides also had higher total non-structural and non-soluble carbohydrate concentrations than A. sessilis at the end of treatments. Our results suggest that higher tolerance to waterlogging and higher photosynthetic capacity may partly explain the invasion success of A. philoxeroides in wetlands.

  11. Frontal Lobe Function in Chess Players

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    Vahid Nejati

    2012-05-01

    Full Text Available 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 dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  12. The NBA’s Maximum Player Salary and the Distribution of Player Rents

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    Kelly M. Hastings

    2015-03-01

    Full Text Available The NBA’s 1999 Collective Bargaining Agreement (CBA included provisions capping individual player pay in addition to team payrolls. This study examines the effect the NBA’s maximum player salary on player rents by comparing player pay from the 1997–1998 and 2003–2004 seasons while controlling for player productivity and other factors related to player pay. The results indicate a large increase in the pay received by teams’ second highest and, to a lesser extent, third highest paid players. We interpret this result as evidence that the adoption of the maximum player salary shifted rents from stars to complementary players. We also show that the 1999 CBA’s rookie contract provisions reduced salaries of early career players.

  13. Generation of a transformant showing higher manganese peroxidase (Mnp) activity by overexpression of Mnp gene in Trametes versicolor.

    Science.gov (United States)

    Yeo, Sumin; Park, Nammee; Song, Hong-Gyu; Choi, Hyoung T

    2007-06-01

    Trametes versicolor has a lignin degrading enzyme system, which is also involved in the degradation of diverse recalcitrant compounds. Manganese-dependent peroxidase (MnP) is one of the lignin degrading enzymes in T. versicolor. In this study, a cDNA clone of a putative MnP-coding gene was cloned and transferred into an expression vector (pBARGPE1) carrying a phosphinothricin resistance gene (bar) as a selectable marker to yield the expression vector, pBARTvMnP2. Transformants were generated through genetic transformation using pBARTvMnP2. The genomic integration of the MnP clone was confirmed by PCR with bar-specific primers. One transformant showed higher enzyme activity than the recipient strain did, and was genetically stable even after 10 consecutive transfers on non-selective medium.

  14. Comparison of static and dynamic balance among collegiate cricket, soccer and volleyball male players

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    P Ratan Khuman

    2014-01-01

    Full Text Available Background: Athletes from different sports requires balance control for their better performance depending on game type they involved. When prescribing balance exercises to athletes in different sports, it may be important to recognize performance variations. Objective: The objective of the present study was to compare the static and dynamic balance among collegiate cricket, soccer and volleyball male players. Materials and Methods: A total of 150 students, college level male players from five different colleges were requited for the study with purposive sampling. They were assigned into three different groups according to their types of sports, cricket n = 50, soccer n = 50, volleyball n = 50. The static and dynamic balance was assessed using flamingo balance test (FBT and star excursion balance test (SEBT in institutional based sports physiotherapy department. Results: Intra-group comparison for FBT and SEBT score shows no significance difference (P > 0.05. Multiple comparison of FBT and SEBT score between groups reveals significantly difference between cricket and soccer player (P = 0.000, between cricket and volleyball player (P = 0.000 and between soccer player and volleyball players (P = 0.000. FBT and SEBT score were significantly higher in soccer players than volleyball and cricketer were found to have the least score compared with soccer and volleyball players. Conclusion: There is significance difference in static and dynamic balance among collegiate cricket, soccer and volleyball male players. The soccer players demonstrate higher balance than volleyball players and the volleyball players have a higher balance than that of cricketers both statically and dynamically.

  15. Two bee-pollinated plant species show higher seed production when grown in gardens compared to arable farmland.

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    John Cussans

    Full Text Available Insect pollinator abundance, in particular that of bees, has been shown to be high where there is a super-abundance of floral resources; for example in association with mass-flowering crops and also in gardens where flowering plants are often densely planted. Since land management affects pollinator numbers, it is also likely to affect the resultant pollination of plants growing in these habitats. We hypothesised that the seed or fruit set of two plant species, typically pollinated by bumblebees and/or honeybees might respond in one of two ways: 1 pollination success could be reduced when growing in a floriferous environment, via competition for pollinators, or 2 pollination success could be enhanced because of increased pollinator abundance in the vicinity.We compared the pollination success of experimental plants of Glechoma hederacea L. and Lotus corniculatus L. growing in gardens and arable farmland. On the farms, the plants were placed either next to a mass-flowering crop (oilseed rape, Brassica napus L. or field beans, Vicia faba L. or next to a cereal crop (wheat, Triticum spp.. Seed set of G. hederacea and fruit set of L. corniculatus were significantly higher in gardens compared to arable farmland. There was no significant difference in pollination success of G. hederacea when grown next to different crops, but for L. corniculatus, fruit set was higher in the plants growing next to oilseed rape when the crop was in flower.The results show that pollination services can limit fruit set of wild plants in arable farmland, but there is some evidence that the presence of a flowering crop can facilitate their pollination (depending on species and season. We have also demonstrated that gardens are not only beneficial to pollinators, but also to the process of pollination.

  16. Apollo Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep Space Radiation Effects on the Vascular Endothelium.

    Science.gov (United States)

    Delp, Michael D; Charvat, Jacqueline M; Limoli, Charles L; Globus, Ruth K; Ghosh, Payal

    2016-07-28

    As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth's protective magnetosphere into the more intense deep space radiation environment. The primary purpose of this study was to determine whether mortality rates due to cardiovascular disease (CVD), cancer, accidents and all other causes of death differ in (1) astronauts who never flew orbital missions in space, (2) astronauts who flew only in low Earth orbit (LEO), and (3) Apollo lunar astronauts, the only humans to have traveled beyond Earth's magnetosphere. Results show there were no differences in CVD mortality rate between non-flight (9%) and LEO (11%) astronauts. However, the CVD mortality rate among Apollo lunar astronauts (43%) was 4-5 times higher than in non-flight and LEO astronauts. To test a possible mechanistic basis for these findings, a secondary purpose was to determine the long-term effects of simulated weightlessness and space-relevant total-body irradiation on vascular responsiveness in mice. The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction. Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD among astronauts exposed to deep space radiation.

  17. Mental rotation performance in male soccer players.

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    Petra Jansen

    Full Text Available 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.

  18. Athlete's heart patterns in elite rugby players: effects of training specificities.

    Science.gov (United States)

    Chevalier, Laurent; Kervio, Gaëlle; Corneloup, Luc; Vincent, Marie-Pierre; Baudot, Christophe; Rebeyrol, Jean-Louis; Merle, Francis; Gencel, Laurent; Carré, François

    2013-02-01

    Athlete's heart patterns have been widely described. However, to our knowledge, few studies have focused on professional rugby players, who train differently according to their field position. To describe electrocardiographic and echocardiographic patterns observed in elite rugby players according to their field position. One hundred and thirty-five professional rugby players at the end of the competitive season were included. According to a modified Pelliccia's classification, 68.1% of electrocardiograms were normal or had minor abnormalities, 27.2% were mildly abnormal and 3.7% were distinctly abnormal. Heart rate was higher in scrum first-row players (P<0.05). Absolute and indexed left ventricular end-diastolic internal diameters (LVIDd; absolute value 59.3±4.7 mm) exceeded 65 mm and 32 mm/m2 in 13% and 1.5% of players, respectively. Indexed LVIDd values were higher in back players (P<0.001). Left ventricular interventricular septum and posterior wall thicknesses (absolute values 9.4±1.7 mm and 9.2±1.6 mm, respectively) exceeded 13 mm in 3.7% of players. Concentric cardiac hypertrophy was noted in 3.7% of players. Except for one Wolff-Parkinson-White pattern, players with significant ECG or echocardiographic abnormalities showed no cardiovascular event or disease during follow-up. Thus, elite rugby players present similar heart patterns to elite athletes in other sports. Major electrocardiographic and echocardiographic abnormalities are quite rare. Eccentric cardiac remodelling is more frequent in back players. Copyright © 2013. Published by Elsevier Masson SAS.

  19. Genes with stable DNA methylation levels show higher evolutionary conservation than genes with fluctuant DNA methylation levels.

    Science.gov (United States)

    Zhang, Ruijie; Lv, Wenhua; Luan, Meiwei; Zheng, Jiajia; Shi, Miao; Zhu, Hongjie; Li, Jin; Lv, Hongchao; Zhang, Mingming; Shang, Zhenwei; Duan, Lian; Jiang, Yongshuai

    2015-11-24

    Different human genes often exhibit different degrees of stability in their DNA methylation levels between tissues, samples or cell types. This may be related to the evolution of human genome. Thus, we compared the evolutionary conservation between two types of genes: genes with stable DNA methylation levels (SM genes) and genes with fluctuant DNA methylation levels (FM genes). For long-term evolutionary characteristics between species, we compared the percentage of the orthologous genes, evolutionary rate dn/ds and protein sequence identity. We found that the SM genes had greater percentages of the orthologous genes, lower dn/ds, and higher protein sequence identities in all the 21 species. These results indicated that the SM genes were more evolutionarily conserved than the FM genes. For short-term evolutionary characteristics among human populations, we compared the single nucleotide polymorphism (SNP) density, and the linkage disequilibrium (LD) degree in HapMap populations and 1000 genomes project populations. We observed that the SM genes had lower SNP densities, and higher degrees of LD in all the 11 HapMap populations and 13 1000 genomes project populations. These results mean that the SM genes had more stable chromosome genetic structures, and were more conserved than the FM genes.

  20. Risk Factors for Injuries in Professional Football Players.

    Science.gov (United States)

    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 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.

  1. PSI showed higher tolerance to Sb(V) than PSII due to stimulation of cyclic electron flow around PSI.

    Science.gov (United States)

    Wang, Shuzhi; Pan, Xiangliang; Zhang, Daoyong

    2015-01-01

    The knowledge of the effects of Sb(V) on the physiological characteristics of cyanobacteria was still limited. In the present study, responses of photosystem I and II (PSI and PSII), cyclic electron flow (CEF), and interphotosystem electron transport of Microcystis aeruginosa to 5-100 mg/l Sb(V) were synchronously measured using the Dual-PAM-100. 5 mg/l Sb (V) significantly inhibited PSII activity, but had no significant effects on PSI activity. At higher concentrations of Sb(V), the quantum yield and electron transport of PSI were less affected compared to PSII. The ratio of Y(II)/Y(I) significantly decreased with increasing Sb(V) concentration. It decreased from 0.7 for control to 0.4 for 100 mg/l Sb(V)-treated cells, indicating that the change of the distribution of quantum yields between two photosystems and more serious inhibition of PSII under stress of Sb(V) compared to PSI. CEF was activated associated with the inhibition of linear electron flow after exposure to Sb(V). The contribution of Y(CEF) to the quantum yield and activity of PSI increased with increasing Sb(V) concentrations. The cyclic electron transport rate made a significant contribution to electron transport rate of PSI, especially at high Sb(V) concentration (100 mg/l) and high illumination (above 555 μmol photons/m(2)/s). The stimulation of CEF was essential for the higher tolerance of PSI than PSII to Sb(V).

  2. Association mapping for phenology and plant architecture in maize shows higher power for developmental traits compared with growth influenced traits.

    Science.gov (United States)

    Bouchet, S; Bertin, P; Presterl, T; Jamin, P; Coubriche, D; Gouesnard, B; Laborde, J; Charcosset, A

    2017-03-01

    Plant architecture, phenology and yield components of cultivated plants have repeatedly been shaped by selection to meet human needs and adaptation to different environments. Here we assessed the genetic architecture of 24 correlated maize traits that interact during plant cycle. Overall, 336 lines were phenotyped in a network of 9 trials and genotyped with 50K single-nucleotide polymorphisms. Phenology was the main factor of differentiation between genetic groups. Then yield components distinguished dents from lower yielding genetic groups. However, most of trait variation occurred within group and we observed similar overall and within group correlations, suggesting a major effect of pleiotropy and/or linkage. We found 34 quantitative trait loci (QTLs) for individual traits and six for trait combinations corresponding to PCA coordinates. Among them, only five were pleiotropic. We found a cluster of QTLs in a 5 Mb region around Tb1 associated with tiller number, ear row number and the first PCA axis, the latter being positively correlated to flowering time and negatively correlated to yield. Kn1 and ZmNIP1 were candidate genes for tillering, ZCN8 for leaf number and Rubisco Activase 1 for kernel weight. Experimental repeatabilities, numbers of QTLs and proportion of explained variation were higher for traits related to plant development such as tillering, leaf number and flowering time, than for traits affected by growth such as yield components. This suggests a simpler genetic determinism with larger individual QTL effects for the first category.

  3. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Nadja Rebecca [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Wehrli, Bernhard [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland)

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L{sup −1} molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L{sup −1}. From OPV, copper (14 μg L{sup −1}), zinc (87 μg L{sup −1}) and silver (78 μg L{sup −1}) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. - Highlights: • Photovoltaics may be disposed in the environment after usage. • Copper indium gallium selenide (CIGS) and organic (OPV) cells were compared. • Morphological and molecular effects were assessed in zebrafish embryos. • Environmental condition affected metal leaching and ecotoxicological activity. • Damaged CIGS cells pose higher risk to the environment than OPV cells.

  4. Higher frequency of social learning in China than in the West shows cultural variation in the dynamics of cultural evolution.

    Science.gov (United States)

    Mesoudi, Alex; Chang, Lei; Murray, Keelin; Lu, Hui Jing

    2015-01-07

    Cultural evolutionary models have identified a range of conditions under which social learning (copying others) is predicted to be adaptive relative to asocial learning (learning on one's own), particularly in humans where socially learned information can accumulate over successive generations. However, cultural evolution and behavioural economics experiments have consistently shown apparently maladaptive under-utilization of social information in Western populations. Here we provide experimental evidence of cultural variation in people's use of social learning, potentially explaining this mismatch. People in mainland China showed significantly more social learning than British people in an artefact-design task designed to assess the adaptiveness of social information use. People in Hong Kong, and Chinese immigrants in the UK, resembled British people in their social information use, suggesting a recent shift in these groups from social to asocial learning due to exposure to Western culture. Finally, Chinese mainland participants responded less than other participants to increased environmental change within the task. Our results suggest that learning strategies in humans are culturally variable and not genetically fixed, necessitating the study of the 'social learning of social learning strategies' whereby the dynamics of cultural evolution are responsive to social processes, such as migration, education and globalization.

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

    Science.gov (United States)

    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

  6. Verbal aggressiveness and state anxiety of volleyball players and coaches.

    Science.gov (United States)

    Bekiari, Alexandra; Patsiaouras, Asterios; Kokaridas, Dimitrios; Sakellariou, Kimon

    2006-10-01

    The purpose of the present study was to examine the relation of verbal aggressiveness and state anxiety (somatic, cognitive, and self-confidence) in sports settings based on the ratings by volleyball coaches and their athletes. The sample consisted of volleyball athletes (n=208; 98 men and 110 women) and their coaches (n=20; 16 men and 4 women). Analysis showed that male volleyball players rated somatic anxiety higher and were more affected by the verbal aggressiveness of their coaches than female volleyball players. No mean differences were significant for male and female coaches on somatic or cognitive anxiety, self-confidence, or verbal aggressiveness. Also, correlation between subscale scores for male and female volleyball players and coaches was found. The correlations of verbal aggressiveness with self-confidence and anxiety were positive for these athletes, leading them to better behavior. This relationship needs further examination in sport settings.

  7. Cognitive Functions in Elite and Sub-Elite Youth Soccer Players Aged 13 to 17 Years.

    Science.gov (United States)

    Huijgen, Barbara C H; Leemhuis, Sander; Kok, Niels M; Verburgh, Lot; Oosterlaan, Jaap; Elferink-Gemser, Marije T; Visscher, Chris

    2015-01-01

    Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in elite and sub-elite youth soccer players aged 13-17 years. A total of 47 elite youth soccer players (mean age 15.5 years, SD = 0.9) and 41 sub-elite youth soccer players (mean age 15.2 years, SD = 1.2) performed tasks for "higher-level" cognitive functions measuring working memory (i.e., Visual Memory Span), inhibitory control (i.e., Stop-Signal Task), cognitive flexibility (i.e., Trail Making Test), and metacognition (i.e., Delis-Kaplan Executive Function System Design Fluency Test). "Lower-level" cognitive processes, i.e., reaction time and visuo-perceptual abilities, were also measured with the previous tasks. ANOVA's showed that elite players outscored sub-elite players at the "higher-level" cognitive tasks only, especially on metacognition (p soccer players on inhibitory control (p = .001), and cognitive flexibility (p = .042), but not on metacognition (p = .27). No differences were found concerning working memory nor the "lower-level" cognitive processes (p > .05). In conclusion, elite youth soccer players have better inhibitory control, cognitive flexibility, and especially metacognition than their sub-elite counterparts. However, when training hours are taken into account, differences between elite and sub-elite youth soccer players remain apparent on inhibitory control and cognitive flexibility in contrast to metacognition. This highlights the need for longitudinal studies to further investigate the importance of "higher-level" cognitive functions for talent identification, talent development and performance in soccer.

  8. Neuropsychological consequence of soccer play in adolescent U.K. School team soccer players.

    Science.gov (United States)

    Stephens, Richard; Rutherford, Andrew; Potter, Douglas; Fernie, Gordon

    2010-01-01

    To assess mild head injury effects in adolescent soccer players, neuropsychological performance across school team soccer players, rugby players and noncontact sport players was assessed in a quasi-experimental cross-sectional design. One hundred eighty-five males were tested (ages 13-16; response rate 55%) and 86 contributed data to the analyses after exclusion for recent concussion and overlapping sports participation. Soccer players showed lower premorbid intellectual functioning, but neither soccer players nor rugby players showed neuropsychological decrement compared with noncontact sport players. Cumulative heading did not predict neuropsychological performance. While no specific attribute of soccer was linked with neuropsychological impairment, head injury predicted reduced attention for all participants.

  9. Monitoring performance, pituitary-adrenal hormones and mood profiles: how to diagnose non-functional over-reaching in male elite junior soccer players.

    Science.gov (United States)

    Schmikli, Sándor L; de Vries, Wouter R; Brink, Michel S; Backx, Frank Jg

    2012-11-01

    To verify if in male elite junior soccer players a minimum 1-month performance decrease is accompanied by a mood profile and hormone levels typical of non-functional over-reaching (NFOR). A prospective case-control study using a monthly performance monitor with a standardised field test to detect the performance changes. Players with a performance decrease lasting at least 1 month were compared with control players without a performance decrease on mood scores and pre-exercise and postexercise levels of stress hormones. Sporting field and sports medical laboratory. Ninety-four young elite soccer players were monitored during the 2006-2008 seasons. Twenty-one players were invited to the laboratory, seven of whom showed a significant performance decrease. Performance change over time, scores on the profile of mood states and premaximal and postmaximal exercise serum levels of adrenocorticotropic hormone (ACTH), growth hormone (GH) and cortisol. Players with a performance decrease showed psychological and hormonal changes typical of the non-functional state of over-reaching. Scores were higher on depression and anger, whereas the resting GH levels and ACTH levels after maximal exercise were reduced. ACTH and GH were capable of classifying all but one player correctly as either NFOR or control. Performance-related criteria in field tests are capable of identifying players with worsened mood and adaptations of the endocrine system that fit the definition of NFOR. Performance, mood and hormone levels may therefore be considered as valid instruments to diagnose NFOR in young elite soccer players.

  10. Multi-Player and Multi-Choice Quantum Game

    Institute of Scientific and Technical Information of China (English)

    杜江峰; 李卉; 许晓栋; 周先意; 韩荣典

    2002-01-01

    We investigate a multi-player and multi-choice quantum game. We start from a two-player and two-choice game,and the result is better than its classical version. Then we extend this to N-player and N-choice cases. In the quantum domain, we provide a strategy with which players can always avoid the worst outcome. Also, by changing the value of the parameter of the initial state, the probabilities for players to obtain the best pay-off will be much higher than in its classical version.

  11. Impaired probability estimation and decision-making in pathological gambling poker players.

    Science.gov (United States)

    Linnet, Jakob; Frøslev, Mette; Ramsgaard, Stine; Gebauer, Line; Mouridsen, Kim; Wohlert, Victoria

    2012-03-01

    Poker has gained tremendous popularity in recent years, increasing the risk for some individuals to develop pathological gambling. Here, we investigated cognitive biases in a computerized two-player poker task against a fictive opponent, among 12 pathological gambling poker players (PGP), 10 experienced poker players (ExP), and 11 inexperienced poker players (InP). Players were compared on probability estimation and decision-making with the hypothesis that ExP would have significantly lower cognitive biases than PGP and InP, and that the groups could be differentiated based on their cognitive bias styles. The results showed that ExP had a significantly lower average error margin in probability estimation than PGP and InP, and that PGP played hands with lower winning probability than ExP. Binomial logistic regression showed perfect differentiation (100%) between ExP and PGP, and 90.5% classification accuracy between ExP and InP. Multinomial logistic regression showed an overall classification accuracy of 23 out of 33 (69.7%) between the three groups. The classification accuracy of ExP was higher than that of PGP and InP due to the similarities in probability estimation and decision-making between PGP and InP. These impairments in probability estimation and decision-making of PGP may have implications for assessment and treatment of cognitive biases in pathological gambling poker players.

  12. Effect of the Game Design, the Goal Type and the Number of Players on Intensity of Play in Small-Sided Soccer Games in Youth Elite Players

    Directory of Open Access Journals (Sweden)

    González-Rodenas Joaquín

    2015-12-01

    Full Text Available The aim of this study was to compare the effects of game design modification, the type of the goal and the number of players on the intensity of play in small-sided soccer games (SSGs in youth elite players. Twenty young soccer players (age 13.7 ± 0.5 years, body mass 57.4 ± 7.8 kg, body height 1.67 ± 7.8 m, maximal heart rate 201.1 ± 8.2 beats/min performed three types of SSGs (possession play (PP vs. regular goals (RG vs. small goals (SG in both four-a-side and six-a-side formats. The heart rate responses were recorded and analysed as an indicator of the intensity of play. The four-a-side format obtained higher intensity of play than six-a-side for PP (p<0.05, but not for SG and RG. SG showed higher intensity of play than RG for four-a-side (p<0.001, but not for six-a-side. PP registered higher intensity of play than RG (p<0.05, but not than SG in four-a-side, whereas in six-a-side no differences were found between the three formats. In conclusion, the modification of variables such as the number of players, the game design and the type of the goal influences the intensity of play in small-sided soccer games in youth players.

  13. Executive functioning in highly talented soccer players.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Serotonin axons of the neostriatum show a higher affinity for striatal than for ventral mesencephalic transplants: a quantitative study in adult and immature recipient rats.

    Science.gov (United States)

    Pierret, P; Vallée, A; Bosler, O; Dorais, M; Moukhles, H; Abbaszadeh, R; Lepage, Y; Doucet, G

    1998-07-01

    We previously showed that grafts of fetal ventral mesencephalic tissue are practically not innervated by host serotonin (5-HT) axons after implantation into the striatum of rats aged more than 14 days, at variance with transplants of cortical or striatal tissue into the adult striatum, which are well innervated by these axons. Using 5-HT immunohistochemistry and in vitro [3H]5-HT uptake/autoradiography, we have examined and quantified the innervation of ventral mesencephalic versus striatal grafts several months after implantation into the striatum of neonatal (postnatal day 5 or P5), juvenile (P15), and adult rats. Ventral mesencephalic grafts implanted in P5 rats received a moderate 5-HT innervation, while similar grafts implanted in P15 or adult recipients were almost free of any 5-HT fibers (-80%, compared to P5). The density of 5-HT innervation showed a tendency toward higher values in striatal than in ventral mesencephalic grafts (1.6-2 times higher in P5 and adult recipients; 4 times higher in P15 recipients). The difference was more striking, and significant, when only the true striatal portions of the striatal grafts were considered, i.e., DARPP-32-immunopositive areas (4-5 times higher in P5 and adult recipients; 10 times higher in P15 recipients). Accordingly, these DARPP-32-positive areas were also more densely innervated than the DARPP-32-negative zones of the same grafts (3 times higher at any age). The 5-HT innervation density also decreased with increasing age of the recipients in DARPP-32-positive, as well as DARPP-32-negative compartments of the striatal grafts (-75% in adults), but this decrease appeared more gradual (-50% in juveniles) than with mesencephalic grafts. It is concluded that the 5-HT axons innervating the neostriatum have a better affinity for striatal grafts than for ventral mesencephalic grafts or the nonstriatal portions of striatal grafts. In adulthood, the relative affinity of these axons for the different types of grafts is

  16. Beneficial Long Communication in the Multi-Player Electronic Mail Game

    NARCIS (Netherlands)

    De Jaegher, K.J.M.

    2015-01-01

    In the two-player electronic mail game (EMG), as is well-known, the probability of collective action is lower the more confirmations and re-confirmations are made available to players. In the multi-player EMG, however, as we show players may coordinate on equilibria where they require only few of

  17. Heart rate, blood lactate concentration, and time-motion analysis of female basketball players during competition.

    Science.gov (United States)

    Matthew, Dionne; Delextrat, Anne

    2009-06-01

    The aim of this study was to examine the physiological demands and movement patterns of female basketball players after changes in the rules of the game. Nine varsity players were studied during nine official games. Each game was videotaped to identify the frequencies of the main movements performed, heart rate was recorded continuously, and blood samples were collected to determine blood lactate concentration when the competition rules allowed. The main results showed that the players performed on average 652 +/- 128 movements per game, which corresponded to a change in activity every 2.82 s. Mean heart rate was 165 +/- 9 beats . min(-1) (89.1% of maximum heart rate) for total time and 170 +/- 8 beats . min(-1) (92.5% of maximum) for live time. Mean blood lactate concentration was 5.2 +/- 2.7 mmol . l(-1) (55.9% of maximum blood lactate concentration). In addition, heart rates were significantly higher in the first half than the second half of games. These results indicate: (1) a greater physiological load compared with previous studies on female players tested before the rules modification (Beam & Merrill, 1994; McArdle et al., 1971) and (2) lower movement frequencies compared with male players competing under modern rules (Ben Abdelkrim et al., 2007). These observations must be taken into account by coaches and conditioning specialists working with female players.

  18. Soccer Players Cultural Capital and Its Impact on Migration

    Science.gov (United States)

    Leskošek, Bojan; Vodičar, Janez; Topič, Mojca Doupona

    2016-01-01

    Abstract The purpose of this study was to identify factors that constituted the cultural capital among soccer players. We assumed that in the increasingly globalized world of professional soccer, a player’s success would often depend on migrating and adjusting to life in other countries. Willingness to migrate and successful adjustment are tied to player’s previous attitudes and/or behaviours (habitus), significant support from others, including family members, and previous experiences and success in sports and education. Our hypothesised model of the cultural capital was based on the Pierre Bourdieu’s theoretical framework. It consisted of 26 variables related to three sets of factors: soccer experiences, a family context and support, and educational achievements of the players and their parents. The model was tested using a sample of 79 current soccer coaches who also had been players at the elite level. A factor analysis was used to empirically verify the content of the hypothetical model of the soccer players’ cultural capital. Nine latent factors were extracted and together, they accounted for 55.01% of the total model variance. Individual factors obtained showed a sufficient level of substantial connection. The Cronbach’s alpha value of 0.77 confirmed the internal consistency of the operationalised variables in the hypothetical model. In addition, the impact of these aforementioned life dimensions on the migration of soccer players was studied. The results of the binary logistic regression analysis showed that the first factor of the hypothetical model (F1) had 2.2 times and the second factor (F8) had 3.9 times higher odds for migration abroad. Sociocultural findings using this new assessment approach could help create better “success conditions” in the talent development of young players. PMID:28031770

  19. Position-Related Differences in Selected Morphological Body Characteristics of Top-Level Female Handball Players.

    Science.gov (United States)

    Bon, Marta; Pori, Primoz; Sibila, Marko

    2015-09-01

    The study aimed to establish the main morphological characteristics of Slovenian junior and senior female national handball team players. Morphological characteristics of various player subgroups (goalkeepers, wings, back players and pivots) were also determined so as to establish whether they had distinct profiles. The subjects were 87 handball players who were members of the Slovenian junior and senior female national teams in the period from 2003 to 2009. A standardised anthropometric protocol was used to assess the subjects' morphological characteristics. The measurements included 23 different anthropometric measures. First, basic statistical characteristics of anthropometric measures were obtained for all subjects together and then for each group separately. Somatotypes were determined using Heath-Carter's method. Endomorphic, mesomorphic and ectomorphic components were calculated by computer on the basis of formulas. In order to determine differences in the body composition and anthropometric data of the subjects playing in different positions, a one-way analysis of variance was employed. The results show that, on average, the wings differed the most from the other player groups in terms of their morphological body characteristics. The wings differed most prominently from the other player groups in terms of their morphological body parameters as they were significantly smaller and had a statistically significantly lower body mass than the other groups. In terms of transversal measures of the skeleton and the circumferences, the wings significantly differed mainly from the pivots and goalkeepers and less from the backs. The goalkeepers were the tallest, with high values of body mass and low values of transversal measures compared to P. Their skin folds were the most pronounced among all the groups on average and their share of subcutaneous fat in total body mass was the highest. Consequently, their endomorphic component of the somatotype was pronounced

  20. Menstrual cycle disorders in female volleyball players.

    Science.gov (United States)

    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.

  1. “I Want to be There When He Graduates:” Foster Parents Show Higher Levels of Commitment than Group Care Providers

    Science.gov (United States)

    Lo, Albert; Roben, Caroline K.P.; Maier, Collin; Fabian, Kim; Shauffer, Carole; Dozier, Mary

    2015-01-01

    Group care is a frequent placement for adolescents placed in out of home care when their birth parents’ care is deemed unsafe. In the present study, we assessed whether foster parents show greater commitment to children than group care providers. Given that group care represents a number of living arrangements, we considered both shift care (where staff work shifts and do not live with the children) and cottage care (where staff live for extended periods of time with the children in a group living context). Commitment was assessed using the This Is My Child Interview (adapted for adolescents). Thirty-one foster parents, 18 shift workers, and 28 cottage care providers were interviewed. As predicted, foster parents showed higher levels of commitment than both shift care workers and cottage care providers, and the associations held when children’s externalizing behaviors and the number of children the caregivers had cared for were controlled. The results suggest that foster care promotes greater commitment among caregivers than other out of home placements, and add to other findings that favor foster care as the out of home placement of choice for adolescents. PMID:25937687

  2. Attributes of top elite team-handball players.

    Science.gov (United States)

    Massuça, Luís M; Fragoso, Isabel; Teles, Júlia

    2014-01-01

    Researchers in the field of excellence in sport performance are becoming increasingly focused on the study of sport-specific characteristics and requirements. In accordance with this, the purposes of this study were (a) to examine the morphologic-, fitness-, handball-specific skills and psychological and "biosocial" differences between top elite and nontop elite team-handball players and (b) to investigate the extent to which they may be used to identify top elite team-handball players. One hundred sixty-seven adult male team-handball players were studied and divided in 2 groups: top elite (n = 41) and nontop elite (n = 126). Twenty-eight morphologic-, 9 fitness-, 1 handball-specific skills and 2 psychological-based and 2 "biosocial"-based attributes were used. Top elite and nontop elite groups were compared for each variable of interest using Student's t-test, and 5 logistic regression analyses were performed with the athlete's performance group (top elite or nontop elite) as the dependent variable and the variables of each category as predictors. The results showed that (a) body mass, waist girth, radiale-dactylion length, midstylion-dactylion length, and absolute muscle mass (morphologic model); (b) 30-m sprint time, countermovement jump height and average power, abdominal strength and the class of performance in the Yo-Yo Intermittent Endurance Test (fitness model); (c) offensive power (specific-skills model); (d) ego-based motivational orientation (psychological model); (e) socioeconomic status and the energy spent (for week) in handball activity (biosocial model); significantly (p handball player. Moreover, the fitness model exhibited higher percentages of correct classification (i.e., 91.5%) than all the other models did. This study provided (a) the rational to reduce the battery of tests for evaluation purposes, and (b) the initial step to work on building a multidisciplinary model to predict the probability of a handball athlete to be a top elite player.

  3. Assessment of professional baseball players aerobic exercise performance depending on their positions.

    Science.gov (United States)

    Yang, Seung-Won

    2014-11-01

    This study reports the average and SD of professional baseball players' cardiorespiratory endurance, maximum oxygen consumption, oxygen consumption during anaerobic threshold, maximum oxygen consumption of anaerobic threshold %, maximum heart rate, and heart rate of anaerobic threshold. We also report the comparison between pitchers and fielders. Considering the total number of results, percentile was used and results were classified into 5 grades. One professional baseball players' organization with more than 14 years of experience participated in this study. First, we observed that the average pitchers' V[Combining Dot Above]O2max was 53.64 ml·kg·min, whereas the average fielders' was 52.30 ml·kg·min. These values were lower than other sports players. Second, in case of the V[Combining Dot Above]O2AT, pitchers showed 39.35 ml·kg·min and fielders showed 39.96 ml·kg·min. %V[Combining Dot Above]O2AT showed a significant difference of 71.13% between pitchers and fielders-pitchers, whereas fielders showed 73.89% (p baseball players and higher than other sports players. In conclusion, both professional baseball pitchers and fielders should be aware of the necessity of systematic cardiorespiratory endurance data analysis. Moreover, baseball teams, athletic trainers, and coaches should also be aware of the importance of cardiorespiratory endurance.

  4. RETIRED MATCHES AMONG MALE PROFESSIONAL TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Kristijan Breznik

    2012-06-01

    Full Text Available The aim of this study was to explore the effect of characteristics of various games and players on the proportion of retired tennis matches in the Open Era of tennis. The data included over 420,000 matches played among 17,553 tennis players in the period from 1968 to the end of 2010. The influence of the surface type was clearly confirmed, with the proportion of retired matches being higher on hard and clay courts compared to grass and carpet surfaces. Similarly, more retired matches were observed in outdoor venues than in indoor ones. The impact of other variables, tournament types, rounds at which the game was played and both players' ranks, is more ambiguous. Our interpretation of the obtained results is presented in the paper. Network analytic methods were applied to extract players with the most retired matches in their careers. Eventually, we defined a group of top tennis players and gave a more precise insight into retired matches in that group. Correspondence analysis was used to visually display the two-mode network of top players and the proportion of retired matches by surface type

  5. The Player Engagement Process

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik

    2011-01-01

    Engagement is an essential element of the player experience, and the concept is described in various ways in the literature. To gain a more detailed comprehension of this multifaceted concept, and in order to better understand what aspects can be used to evaluate engaging game play and to design...... engaging user experiences, this study investigates one dimension of player engagement by empirically identifying the components associated with the desire to continue playing. Based on a description of the characteristics of player engagement, a series of surveys were developed to discover the components......, categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  6. MRI findings in soccer players with long-standing adductor-related groin pain and asymptomatic controls

    DEFF Research Database (Denmark)

    Branci, Sonia; Thorborg, Kristian; Bech, Birthe Højlund

    2015-01-01

    soccer players displayed different positive MRI findings, and asymptomatic soccer players had significantly higher odds (OR ranging from 6.3 to 13.3) for BMO, adductor tendinopathy and degenerative changes than non-soccer players. CONCLUSIONS: ARGP in soccer players was associated with central disc...

  7. Technical Performance Analysis of Iran Premier League Soccer Players in 2012-2013 Season

    Directory of Open Access Journals (Sweden)

    Mohsen Javani

    2015-10-01

    Full Text Available Background and purpose of study : analysis of IRAN premier league soccer players’ technical performance in season 2012-2013, using a computerized match analysis system (Borhan Mobin Development Management Co, IRAN. Material and methods: in this study, data were obtained from 120 players, who performed in competitions 90 minutes. The players were classified into 3 positional roles: defenders, midfielders and forwards. Technical performance variables analysis included: total passes, total successful passes, pass accuracy, total shots; total shots to target, shot accuracy, ball interception and ball losses. The data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, Mann-Whitney U and Tukey post hoc test. Results : The findings of this study showed that players performed about 45 passes per competition. Midfielders and defenders had significantly higher number of passes than forwards. Pass accuracy was about 67% and there were no significant differences between positional roles. Also, the players performed about 0.8 shots per competition, forwards and midfielders had significantly higher number of shots than defenders. Shot accuracy was about 31%; midfielders and forwards had significantly higher shot accuracy than defenders. Forwards showed significantly lower ball interception and higher ball losses than other positions. Conclusion : The result of this study showed that there were significant differences between some technical actions in positional roles. Therefore, coaches can use this information for individualization of training according to playing positions and for optimization of training in the amateur game.

  8. Free-sugar, total-sugar, fibre, and micronutrient intake within elite youth British soccer players: a nutritional transition from schoolboy to fulltime soccer player.

    Science.gov (United States)

    Naughton, Robert J; Drust, Barry; O'Boyle, Andy; Abayomi, Julie; Mahon, Elizabeth; Morton, James P; Davies, Ian G

    2017-01-10

    It is recommended that soccer players consume a high carbohydrate diet to augment performance. However, growing evidence suggests that there is a link between high free-sugar (FS) intake (>5% total energy intake; TEI) and metabolic diseases. Furthermore, foods that are often high in sugar, such as processed foods, are typically lacking in nutrient quality. We therefore analysed total-sugar, FS, dietary fibre, and micronutrient intake of players from an English Premier League academy under (U) 18 (n = 13), U15/16 (n = 25), and U13/14 (n = 21) using a 7-day food diary. Data were compared with current United Kingdom (UK) dietary reference value (DRV) for FS via a t test. The U13/14s (10% ± 18%) and U15/16s (11% ± 30%) both consumed higher amounts of FS in comparison with the UK DRV of 5% TEI (P intake of the U18s was significantly lower than the U13/14s and U15/16s (P intakes were generally met. In conclusion, we provide novel data on dietary sugar, fibre, and micronutrient intake within elite youth soccer players. We report an apparent "nutritional transition" from schoolboy to fulltime soccer player, with U18s showing a significantly lower intake of sugar in comparison with younger squads, and a similar intake of FS to the UK DRVs. Practitioners should target improving player education around sugar and fibre consumption.

  9. Adapting playware to multiple players

    DEFF Research Database (Denmark)

    Þorsteinsson, Arnar Tumi; Lund, Henrik Hautop; Mastorakis, Nikos

    2011-01-01

    With the creation of playware as intelligent hardware and software that creates play, it is possible to adapt the play tool to the individual user, and even to multiple users playing at the same time with the play tool. In this paper, we show how it is possible to implement adaptivity in modular...... to such differences, and argues that adaptivity is needed to make games fit to the individual users in both single-player games and multi-player games. As a case study, we implemented such adaptivity on modular interactive tiles for the single-user game ColorTimer, and for the multiple-user games PingPong, in which...

  10. Energy Balance during Taekwondo Practice in Elite Male Taekwondo Players.

    Science.gov (United States)

    Cho, Kang Ok; Garber, Carol Ewing; Lee, Sukho; Kim, Yeon Soo

    2013-03-01

    The goal of this study was to evaluate energy expenditure and dietary intake of nutrients during Taekwondo practice in elite Korean male Taekwondo players. Elite Korean male high school (high school player: HP; n = 59) and college players (college player: CP; n = 58) wore an accelerometer to measure energy expenditure and recorded their daily dietary intake for nutritional analysis over the course of five days. Nutritional adequacy ratios for total energy (0.82), vitamin C (0.97), calcium (0.78), and folate (0.75) were below recommended levels for all players. When comparing daily nutrient intake and energy expenditure between HP and CP, the HP group had significantly higher total calorie intake (402.7 kcal, p Taekwondo practice, the total energy expenditure (151.2 kcal, p = 0.001), total activity counts (130,674 counts, p = 0.038) and energy expenditure during Taekwondo practice (257.7 kcal, p Taekwondo players.

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

    Science.gov (United States)

    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.

  12. Photosystem I shows a higher tolerance to sorbitol-induced osmotic stress than photosystem II in the intertidal macro-algae Ulva prolifera (Chlorophyta).

    Science.gov (United States)

    Gao, Shan; Zheng, Zhenbing; Gu, Wenhui; Xie, Xiujun; Huan, Li; Pan, Guanghua; Wang, Guangce

    2014-10-01

    The photosynthetic performance of the desiccation-tolerant, intertidal macro-algae Ulva prolifera was significantly affected by sorbitol-induced osmotic stress. Our results showed that photosynthetic activity decreased significantly with increases in sorbitol concentration. Although the partial activity of both photosystem I (PS I) and photosystem II (PS II) was able to recover after 30 min of rehydration, the activity of PS II decreased more rapidly than PS I. At 4 M sorbitol concentration, the activity of PS II was almost 0 while that of PS I was still at about one third of normal levels. Following prolonged treatment with 1 and 2 M sorbitol, the activity of PS I and PS II decreased slowly, suggesting that the effects of moderate concentrations of sorbitol on PS I and PS II were gradual. Interestingly, an increase in non-photochemical quenching occurred under these conditions in response to moderate osmotic stress, whereas it declined significantly under severe osmotic stress. These results suggest that photoprotection in U. prolifera could also be induced by moderate osmotic stress. In addition, the oxidation of PS I was significantly affected by osmotic stress. P700(+) in the thalli treated with high concentrations of sorbitol could still be reduced, as PS II was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), but it could not be fully oxidized. This observation may be caused by the higher quantum yield of non-photochemical energy dissipation in PS I due to acceptor-side limitation (Y(NA)) during rehydration in seawater containing DCMU.

  13. Two-Player Graph Pebbling

    Science.gov (United States)

    Prudente, Matthew James

    Given a graph G with pebbles on the vertices, we define a pebbling move as removing two pebbles from a vertex u, placing one pebble on a neighbor v, and discarding the other pebble, like a toll. The pebbling number pi( G) is the least number of pebbles needed so that every arrangement of pi(G) pebbles can place a pebble on any vertex through a sequence of pebbling moves. We introduce a new variation on graph pebbling called two-player pebbling. In this, players called the mover and the defender alternate moves, with the stipulation that the defender cannot reverse the previous move. The mover wins only if they can place a pebble on a specified vertex and the defender wins if the mover cannot. We define η(G), analogously, as the minimum number of pebbles such that given every configuration of the η( G) pebbles and every specified vertex r, the mover has a winning strategy. First, we will investigate upper bounds for η( G) on various classes of graphs and find a certain structure for which the defender has a winning strategy, no matter how many pebbles are in a configuration. Then, we characterize winning configurations for both players on a special class of diameter 2 graphs. Finally, we show winning configurations for the mover on paths using a recursive argument.

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

    Science.gov (United States)

    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…

  15. Systematic review and meta-analysis shows a specific micronutrient profile in people with Down Syndrome: Lower blood calcium, selenium and zinc, higher red blood cell copper and zinc, and higher salivary calcium and sodium

    Science.gov (United States)

    Saghazadeh, Amene; Mahmoudi, Maryam; Dehghani Ashkezari, Atefeh; Oliaie Rezaie, Nooshin; Rezaei, Nima

    2017-01-01

    Different metabolic profiles as well as comorbidities are common in people with Down Syndrome (DS). Therefore it is relevant to know whether micronutrient levels in people with DS are also different. This systematic review was designed to review the literature on micronutrient levels in people with DS compared to age and sex-matched controls without DS. We identified sixty nine studies from January 1967 to April 2016 through main electronic medical databases PubMed, Scopus, and Web of knowledge. We carried out meta-analysis of the data on four essential trace elements (Cu, Fe, Se, and Zn), six minerals (Ca, Cl, K, Mg, Na, and P), and five vitamins (vitamin A, B9, B12, D, and E). People with DS showed lower blood levels of Ca (standard mean difference (SMD) = −0.63; 95% confidence interval (CI): −1.16 to −0.09), Se (SMD = -0.99; 95% CI: -1.55 to -0.43), and Zn (SMD = -1.30; 95% CI: -1.75 to -0.84), while red cell levels of Zn (SMD = 1.88; 95% CI: 0.48 to 3.28) and Cu (SMD = 2.77; 95% CI: 1.96 to 3.57) were higher. They had also higher salivary levels of Ca (SMD = 0.85; 95% CI: 0.38 to 1.33) and Na (SMD = 1.04; 95% CI: 0.39 to 1.69). Our findings that micronutrient levels are different in people with DS raise the question whether these differences are related to the different metabolic profiles, the common comorbidities or merely reflect DS. PMID:28422987

  16. Norwegian Football Academy Players-Players Self-Assessed Competence, Perfectionism, Goal Orientations and Motivational Climate

    Directory of Open Access Journals (Sweden)

    Eirik Nerland

    2016-06-01

    Full Text Available Grounded in the theoretical framework of achievement goal theory and perfectionism theory, the purpose of this study was to examine how self-assessed perceived abilities covariance these variables among Norwegian football academy players. 140 adolescent football players participated, representing three football academies. Perceived competence was reported as equivalent to or better than others. Perfectionism scores showed personal standards as the highest of the dimensions of perfectionism, while perceived parental pressure was lowest. In contrast, mean task orientation and perceived mastery climate were higher than ego orientation and perceived performance climate. The correlation analysis showed that perceived competence correlated positively with personal standards. Personal standards correlated positively with the rest of the perfectionism dimensions as well as ego orientation, perceived mastery- and performance climate. Concern over mistakes was positively correlated with ego-orientation. Overall, findings suggested that personal standards correlate with perceived competence, while these variables also relate to other perfectionism dimensions, goal orientations and perceived motivational climate. Therefore, coaches should highlight the importance of high personal standards, as a potentially maladaptive function on talent development.

  17. Association between acromioclavicular joint pain and capsular bulging in adolescent baseball players.

    Science.gov (United States)

    Hatta, Taku; Yamamoto, Nobuyuki; Sano, Hirotaka; Nagamoto, Hideaki; Kurokawa, Daisuke; Takahashi, Hiroyuki; Tanaka, Minoru; Koike, Yoichi; Itoi, Eiji

    2016-12-01

    The purpose of this study was to investigate the association between acromioclavicular (AC) joint pain and superior capsular bulging assessed by ultrasound in adolescent baseball players. One hundred and fifty players (1st-8th graders) were examined. All subjects underwent physical examinations, including assessment of tenderness on the AC joint and provocative tests (the Buchberger's test and the cross-body adduction stress test). Bilateral AC joints with the arm in both the resting and the cross-body positions were examined by ultrasound. Twelve of 150 players (8 %) had AC symptoms with both positive tenderness and positive provocative tests. Interestingly, their prevalence increased with age-one of the 70 (1.4 %) 1st-3rd graders, six of 46 (13 %) 4th-6th graders and five of 34 (15 %) 7th-8th graders. Ultrasonography of AC joints in the cross-body position showed that the difference in superior capsular bulging between the throwing and non-throwing sides was significantly greater in symptomatic players (1.6 ± 1.2 mm) than in asymptomatic players (0.2 ± 0.8 mm) (p = 0.002). The prevalence of superior capsular bulging was significantly higher in adolescent baseball players with AC joint pain than in those without it. In adolescent baseball players with shoulder pain, AC joint symptoms should be considered amongst potential causes. Careful observation of these patients is suggested in cases of superior capsular bulging of the AC joint as determined by ultrasonography. III.

  18. A COMPARATIVE STUDY ON THE PHYSICAL FITNESS AND PERFORMANCE OF MALE BASKETBALL PLAYERS IN DIFFERENT DIVISIONS

    Directory of Open Access Journals (Sweden)

    Cihat KORKMAZ

    2012-04-01

    Full Text Available There is a lack of information about the influence of different practice levels on physical fitness and performance variables of male basketball players competing in different divisions. Hence, the purpose of this study is to compare selected physical fitness and performance variables of male players in Turkey National Basketball League’s Division I (D1, II (D2 and III (D3=Regional and to evaluate whether players with different divisional characteristics have different physical fitness and performance variables. From the Turkey basketball league, ninety male basketball players who are competing in the division I (n=30, division II (n=30 and division III (n=30 voluntarily participated in the study. Physical fitness (body height, mass and fat percentage and performance (vertical jump height (VJH, vertical jump power (VJP, VO2max and 20 m sprint measurements were taken in three separate consecutive days following the completion of the first session. D1 and D3 players overall weighed more and D1 players had more body fat (BF and lean body mass (LBM than D2. There were significant differences in VJP between divisions (D1>D2>D3= p≤0.05, but, the differences in sprint ability and body height were not significant. Although there was no difference between D1 and D2 in VO2max and VJH, their values were significantly higher than D3 (p≤0.05. These results showed that in spite of relatively little differences in the average physical characteristics, there were very large statistical differences between divisions in physical performance variables of male basketball players, especially VJP and LBM which is an important criterion of performance at basketball.

  19. Complex Nonlinear Dynamic System of Oligopolies Price Game with Heterogeneous Players Under Noise

    Science.gov (United States)

    Liu, Feng; Li, Yaguang

    A nonlinear four oligopolies price game with heterogeneous players, that are boundedly rational and adaptive, is built using two different special demand costs. Based on the theory of complex discrete dynamical system, the stability and the existing equilibrium point are investigated. The complex dynamic behavior is presented via bifurcation diagrams, the Lyapunov exponents to show equilibrium state, bifurcation and chaos with the variation in parameters. As disturbance is ubiquitous in economic systems, this paper focuses on the analysis of delay feedback control method under noise circumstances. Stable dynamics is confirmed to depend mainly on the low price adjustment speed, and if all four players have limited opportunities to stabilize the market, the new adaptive player facing profits of scale are found to be higher than the incumbents of bounded rational.

  20. A test of self-determination theory with wheelchair basketball players with and without disability.

    Science.gov (United States)

    Perreault, Stephane; Vallarand, Robert J

    2007-10-01

    Guided by Self-Determination Theory (SDT), the present study examined the sport motivation and coping skills of male and female wheelchair basketball players with and without disability (N = 72). In line with SDT, results showed that intrinsic and extrinsic motivation as well as amotivation was found to be present in this sample of wheelchair basketball players. Results also demonstrated that the participants surveyed in the present study scored higher on self-determined types of motivation than non self-determined types of motivation, thus replicating past research with athletes without disability. Furthermore, wheelchair basketball players with and without disability did not differ significantly with respect to sport motivation and coping skills, suggesting that they are more alike than dissimilar. Finally, results revealed that self-determined motivation is associated with enhanced psychological functioning.

  1. Who is the best player ever? A complex network analysis of the history of professional tennis.

    Directory of Open Access Journals (Sweden)

    Filippo Radicchi

    Full Text Available We considered all matches played by professional tennis players between 1968 and 2010, and, on the basis of this data set, constructed a directed and weighted network of contacts. The resulting graph showed complex features, typical of many real networked systems studied in literature. We developed a diffusion algorithm and applied it to the tennis contact network in order to rank professional players. Jimmy Connors was identified as the best player in the history of tennis according to our ranking procedure. We performed a complete analysis by determining the best players on specific playing surfaces as well as the best ones in each of the years covered by the data set. The results of our technique were compared to those of two other well established methods. In general, we observed that our ranking method performed better: it had a higher predictive power and did not require the arbitrary introduction of external criteria for the correct assessment of the quality of players. The present work provides novel evidence of the utility of tools and methods of network theory in real applications.

  2. Who is the best player ever? A complex network analysis of the history of professional tennis

    CERN Document Server

    Radicchi, Filippo

    2011-01-01

    We consider all matches played by professional tennis players between 1968 and 2010, and, on the basis of this data set, construct a directed and weighted network of contacts. The resulting graph shows complex features, typical of many real networked systems studied in literature. We develop a diffusion algorithm and apply it to the tennis contact network in order to rank professional players. Jimmy Connors is identified as the best player of the history of tennis according to our ranking procedure. We perform a complete analysis by determining the best players on specific playing surfaces as well as the best ones in each of the years covered by the data set. The results of our technique are compared to those of two other well established methods. In general, we observe that our ranking method performs better: it has a higher predictive power and does not require the arbitrary introduction of external criteria for the correct assessment of the quality of players. The present work provides a novel evidence of ...

  3. Design of Emergent and Adaptive Virtual Players in a War RTS Game

    CERN Document Server

    Gutiérrez, José A García; Fernández-Leiva, Antonio J

    2012-01-01

    Basically, in (one-player) war Real Time Strategy (wRTS) games a human player controls, in real time, an army consisting of a number of soldiers and her aim is to destroy the opponent's assets where the opponent is a virtual (i.e., non-human player controlled) player that usually consists of a pre-programmed decision-making script. These scripts have usually associated some well-known problems (e.g., predictability, non-rationality, repetitive behaviors, and sensation of artificial stupidity among others). This paper describes a method for the automatic generation of virtual players that adapt to the player skills; this is done by building initially a model of the player behavior in real time during the game, and further evolving the virtual player via this model in-between two games. The paper also shows preliminary results obtained on a one player wRTS game constructed specifically for experimentation.

  4. Executive functions predict the success of top-soccer players.

    Science.gov (United States)

    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.

  5. Executive functions predict the success of top-soccer players.

    Directory of Open Access Journals (Sweden)

    Torbjörn Vestberg

    Full Text Available 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.

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

    Science.gov (United States)

    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

  7. Dribbling determinants in sub-elite youth soccer players.

    Science.gov (United States)

    Zago, Matteo; Piovan, Andrea Gianluca; Annoni, Isabella; Ciprandi, Daniela; Iaia, F Marcello; Sforza, Chiarella

    2016-01-01

    Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s(-1), P run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.

  8. Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin ☆

    OpenAIRE

    Kolyva, Christina; Ghosh, Arnab; Tachtsidis, Ilias; Highton, David; Chris E Cooper; Smith, Martin; Elwell, Clare E.

    2014-01-01

    The redox state of cerebral mitochondrial cytochrome c oxidase monitored with near-infrared spectroscopy (Δ[oxCCO]) is a signal with strong potential as a non-invasive, bedside biomarker of cerebral metabolic status. We hypothesised that the higher mitochondrial density of brain compared to skin and skull would lead to evidence of brain-specificity of the Δ[oxCCO] signal when measured with a multi-distance near-infrared spectroscopy (NIRS) system. Measurements of Δ[oxCCO] as well as of concen...

  9. Arthroscopic Shoulder Surgery in Female Professional Tennis Players

    Science.gov (United States)

    Young, Simon W.; Safran, Marc R.; Dakic, Jodie; Nguyen, Michael L.; Stroia, Kathleen

    2013-01-01

    Objectives: Recent publications have highlighted the relatively poor outcome of other overhead athletes, particularly baseball players, with regard to return to sports at the same or higher level after shoulder surgery. However, true assessment of their ability when returning to sport is not as clear. Further, ability to return to other overhead sports has not been reported. Our objective was to assess outcome and time to return to previous level of function following shoulder surgery in professional tennis players. Methods: The records of all female tennis players on the Women’s Tennis Association (WTA) professional circuit between January 2008 and June 2010 were reviewed to identify players who underwent shoulder surgery on their dominant (serving) shoulder. Details of the surgery including date, procedures performed, and complications were recorded. The primary outcomes were ability and time to return to professional play, and if they were able to return to their previous level of function, as determined by singles ranking. Pre and post-operative singles rankings were used to determine rate and completeness of return to preoperative function. Their highest ranking pre-injury, post operatively, and the time to return to pre-injury ranking were evaluated. Results: During the study period eight professional women tennis players from the WTA underwent shoulder surgery on their dominant arm. All surgery was performed arthroscopically, 7 out of 8 players had more than one procedure performed during the surgery. In total, 3 players underwent debridement of a partial rotator cuff tear and 2 players underwent repair of a complete supraspinatus tear. Three players had an anterior labral repair or reconstruction for anterior instability, and one player underwent repair of a SLAP lesion. Two players underwent neurolysis of a suprascapular nerve, and three players in total underwent a subacromial decompression. All players (100%) returned to professional play. The mean

  10. Adaptivity to Age, Gender, and Gaming Platform Topology in Physical Multi-Player Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Friðriksson, Rafn Vídalín; Björnsson, Davíð Þór

    2012-01-01

    In games where players are competing against each other, it can be of interest to ensure that all players are challenged according to their individual skills. In order to investigate such adaptivity to the individual player in physical multi-player games, we developed a game on modular interactive...... and adults, and between male and female players. Also, results show statistically significant differences in the game interactions between different physical set-ups of the modular interactive tiles, i.e. the interaction depended on the topology of the modular tiles set-up. Changing the physical set......-up of the physical game platform changes the interaction and performance of the players....

  11. Show me the money!’ An insight into the Copyright Licensing Agency (CLA and its interaction with Higher Education Institutions

    Directory of Open Access Journals (Sweden)

    Dinusha Mendis

    2005-09-01

    Full Text Available The aim of this paper will be to provide a case study of the Copyright Licensing Agency (CLA and its inter-action with Higher Education Institutions (HEIs. The paper will begin by introducing and expanding on the concept of higher education institutions and how they have had to adapt to copyright reproduction, especially from the mid twentieth century, with the advent of the photocopy machine. The paper will touch upon the copyright laws that have attempted to regulate copying within HEIs in the UK and consider whether it has been a success or not. The paper will then carry out a study in to CLA and will aim to raise and answer the following question: what really happens to the money that is collected from HEIs by the CLA and distributed through the Authors Licensing and Collecting Society (ALCS and Publishers Licensing Society (PLS? Is the license fee collected from HEIs fairly distributed amongst the right holders? Having looked at both HEIs and collecting societies (CLA specifically, the paper will consider whether collecting societies are the best practical solution we have or whether we are putting up with a system that we have come to know? The UUK v CLA case revealed the dangerous side of collecting societies, especially that of CLA and questioned its motives and aims. In offering a solution, the system in USA will be considered where the US law allows for two or more competing collecting societies in one area. Does competition combat an abuse of a dominant position, which is what we have in the UK and is this the way forward for the UK? Or does competition curtail creativity? Whilst some of these questions have been answered by the author, others have been left open for consideration.

  12. Technical, perceptual and motor skills in novice-expert water polo players: an individual discriminant analysis for talent development.

    Science.gov (United States)

    DʼErcole, Alessandro A; DʼErcole, Cristina; Gobbi, Massimo; Gobbi, Fabio

    2013-12-01

    The 4 tasks (A, B, C, and Y) have the characteristic of containing one more element than the task performed before it. In fact, task B introduces the slalom which is not present in task A. Task C introduces the ball control that are not present in tasks A and B, whereas task Y introduces the slalom and ball control in a visual dual task situation developed in horizontal swimming over a distance of 20 m at maximum speed. This exercise not included in task C. These tasks were performed by a group of pre-adolescent players and national under 18 water polo players. The novice players showed that tasks B and C are predictors of task Y. Such characteristics were not present in the expert players. The novice players also had difficulty in performing task Y because of the visual-attention overload, a difficulty that was not present in the expert players. To improve the 4 skills, the coach of the novice players developed a technical-didactic program, which was checked 6 months after the pretest. The posttest was not significantly different from the pretest while the individual discriminant analysis identified the improvements in some novice players, which on elaboration proved significant, enabling us to distinguish 2 subgroups, one with higher learning rates and the other with lower learning rates. In the practical applications, we describe the didactic tools (task analysis) and the different levels of development of technical skills in water polo. Improvements in these skills are explained through computational models like the HMOSAIC (Hierarchical, Modular, Selection and Identification for Control) while the individual discriminant analysis enables us to do a longitudinal analysis that is not possible with cross-sectional models.

  13. Psychological Gender and Emotional Intelligence in Youth Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Rutkowska Katarzyna

    2015-09-01

    Full Text Available Many sports (for instance soccer are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training. It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes’ emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak. As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was

  14. Psychological Gender and Emotional Intelligence in Youth Female Soccer Players.

    Science.gov (United States)

    Rutkowska, Katarzyna; Bergier, Józef

    2015-09-29

    Many sports (for instance soccer) are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training). It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes' emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska) and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak). As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was average or low

  15. Effect of Imagination on Sport Achievements of Novice Soccer Players

    Directory of Open Access Journals (Sweden)

    Aleksandra E. Gorovaya

    2011-01-01

    Full Text Available This article describes the connection between the use of types of mental imagery by athletes and the level of their imagination. Taking the model of imagery use suggested by K. Martin, S. Moritz and С Hall, the authors used a Russian version of "The Sport Imagery Questionnaire" (SIQ with soccer players 8, 10 and 14 years old. The data shows that subjects with a higher level of imagination are more inclined to use mental imagery in their practice. Age differences in types of imagery usage are shown. The results indicated that mentalimagery training can result in enhanced performance among junior athletes.

  16. A computer vision based web application for tracking soccer players

    OpenAIRE

    Rodrigues, J. M. F.; Cardoso, Pedro J. S.; Vilas, Tiago; Silva, Bruno; Rodrigues, Pedro; Belguinha, António; Gomes, Carlos

    2014-01-01

    Soccer is a sport where everyone that is involved with it make all the efforts aiming for excellence. Not only the players need to show their skills on the pitch but also the coach, and the remaining staff, need to have their own tools so that they can perform at higher levels. Footdata is a project to build a new web application product for soccer (football), which integrates two fundamental components of this sport's world: the social and the professional. While the former is an enhanced so...

  17. Primary hepatocytes from mice lacking cysteine dioxygenase show increased cysteine concentrations and higher rates of metabolism of cysteine to hydrogen sulfide and thiosulfate.

    Science.gov (United States)

    Jurkowska, Halina; Roman, Heather B; Hirschberger, Lawrence L; Sasakura, Kiyoshi; Nagano, Tetsuo; Hanaoka, Kenjiro; Krijt, Jakub; Stipanuk, Martha H

    2014-05-01

    The oxidation of cysteine in mammalian cells occurs by two routes: a highly regulated direct oxidation pathway in which the first step is catalyzed by cysteine dioxygenase (CDO) and by desulfhydration-oxidation pathways in which the sulfur is released in a reduced oxidation state. To assess the effect of a lack of CDO on production of hydrogen sulfide (H2S) and thiosulfate (an intermediate in the oxidation of H2S to sulfate) and to explore the roles of both cystathionine γ-lyase (CTH) and cystathionine β-synthase (CBS) in cysteine desulfhydration by liver, we investigated the metabolism of cysteine in hepatocytes isolated from Cdo1-null and wild-type mice. Hepatocytes from Cdo1-null mice produced more H2S and thiosulfate than did hepatocytes from wild-type mice. The greater flux of cysteine through the cysteine desulfhydration reactions catalyzed by CTH and CBS in hepatocytes from Cdo1-null mice appeared to be the consequence of their higher cysteine levels, which were due to the lack of CDO and hence lack of catabolism of cysteine by the cysteinesulfinate-dependent pathways. Both CBS and CTH appeared to contribute substantially to cysteine desulfhydration, with estimates of 56 % by CBS and 44 % by CTH in hepatocytes from wild-type mice, and 63 % by CBS and 37 % by CTH in hepatocytes from Cdo1-null mice.

  18. Chronically ultraviolet-exposed human skin shows a higher mutation frequency of mitochondrial DNA as compared to unexposed skin and the hematopoietic system.

    Science.gov (United States)

    Berneburg, M; Gattermann, N; Stege, H; Grewe, M; Vogelsang, K; Ruzicka, T; Krutmann, J

    1997-08-01

    Normal ageing processes are associated with an accumulation of mutations within the mitochondrial (mt) DNA. The most frequent mutation is a 4977 base pair (bp) deletion known as common deletion. In order to test the hypothesis that chronically sun-exposed skin is characterized by an increased mutation frequency of mtDNA, the mutation frequency of the common deletion between skin and another replicating tissue (the hematopoietic system) and chronically sun-exposed versus sun-protected skin was compared in the same individuals. This was done by comparing the amount of mutated mtDNA molecules with the whole mitochondrial genome in the same specimen with a semiquantitative polymerase chain reaction method, thus allowing direct comparison of different tissues. In all skin specimens the common deletion could be observed. In contrast only 3 of 10 blood samples revealed detectable amounts of the common deletion. Comparison of sun-exposed versus sun-protected skin exhibited a higher content of the common deletion in sun-exposed skin in 7 of 10 individuals. Additionally, a hitherto undescribed mtDNA mutation was detected exclusively in human skin. These studies indicate that exposure of human skin to solar radiation leads to an accumulation of mtDNA mutations, possibly via oxidative damage, which may play an important role in photoageing.

  19. Do media players cause interference with pacemakers?

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Brunett, Joseph D; Jongnarangsin, Krit; Gardiner, Joseph C; Thakur, Ranjan

    2009-11-01

    Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players. In this prospective, randomized study, 54 patients with dual chamber pacemakers who were in sinus rhythm underwent baseline observation, followed by observation under telemetry communication. These patients were then randomly evaluated with 3 media players (iPod 3G, iPod Photo, and iPod Touch Apple, Cupertino, CA) with and without telemetry communication for 1 minute each. Patients were monitored for pacemaker malfunction using a single-channel ECG during exposure to media players. The pacemaker was interrogated after each exposure and an interrogation report was printed for evaluation. Pacemaker interference was categorized as type I, II, or III. Types I and II interference described telemetry interference and type III interference was defined as any direct interference with pacemaker function or programmed parameters. A total of 54 patients (29 men and 25 women; mean age 77.2 +/- 9.3 y) were evaluated. In total, of the 162 tests (for telemetry interference) 36.4% were positive (Type I and II). Type III interference was also evaluated in 162 tests and none showed any evidence of direct interference. Media players cause telemetry interference with pacemakers, but they do not directly interfere with pacemaker function.

  20. Elastin-insufficient mice show normal cardiovascular remodeling in 2K1C hypertension despite higher baseline pressure and unique cardiovascular architecture.

    Science.gov (United States)

    Wagenseil, Jessica E; Knutsen, Russell H; Li, Dean Y; Mecham, Robert P

    2007-07-01

    Mice heterozygous for the elastin gene (ELN(+/-)) show unique cardiovascular properties, including increased blood pressure and smaller, thinner arteries with an increased number of lamellar units. Some of these properties are also observed in humans with supravalvular aortic stenosis, a disease caused by functional heterozygosity of the elastin gene. The arterial geometry in ELN(+/-) mice is contrary to the increased thickness that would be expected in an animal demonstrating hypertensive remodeling. To determine whether this is due to a decreased capability for cardiovascular remodeling or to a novel adaptation of the ELN(+/-) cardiovascular system, we increased blood pressure in adult ELN(+/+) and ELN(+/-) mice using the two-kidney, one-clip Goldblatt model of hypertension. Successfully clipped mice have a systolic pressure increase of at least 15 mmHg over sham-operated animals. ELN(+/+) and ELN(+/-)-clipped mice show significant increases over sham-operated mice in cardiac weight, arterial thickness, and arterial cross-sectional area with no changes in lamellar number. There are no significant differences in most mechanical properties with clipping in either genotype. These results indicate that ELN(+/+) and ELN(+/-) hearts and arteries remodel similarly in response to adult induced hypertension. Therefore, the cardiovascular properties of ELN(+/-) mice are likely due to developmental remodeling in response to altered hemodynamics and reduced elastin levels.

  1. Differences in energy capacities between tennis players and runners.

    Science.gov (United States)

    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 (ptennis 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.

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

    Science.gov (United States)

    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 concussions in young female soccer players is significantly higher than in a control group of nonsoccer players of the same sex and age.

  3. Countries with Higher Levels of Gender Equality Show Larger National Sex Differences in Mathematics Anxiety and Relatively Lower Parental Mathematics Valuation for Girls.

    Science.gov (United States)

    Stoet, Gijsbert; Bailey, Drew H; Moore, Alex M; Geary, David C

    2016-01-01

    Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls' STEM participation.

  4. Modelling Virtual Camera Behaviour Through Player Gaze

    DEFF Research Database (Denmark)

    Picardi, Andrea; Burelli, Paolo; Yannakakis, Georgios N.

    2012-01-01

    In a three-dimensional virtual environment, aspects such as narrative and interaction largely depend on the placement and animation of the virtual camera. Therefore, virtual camera control plays a critical role in player experience and, thereby, in the overall quality of a computer game. Both game...... industry and game AI research focus on the devel- opment of increasingly sophisticated systems to automate the control of the virtual camera integrating artificial intel- ligence algorithms within physical simulations. However, in both industry and academia little research has been carried out...... on the relationship between virtual camera, game-play and player behaviour. We run a game user experiment to shed some light on this relationship and identify relevant dif- ferences between camera behaviours through different game sessions, playing behaviours and player gaze patterns. Re- sults show that users can...

  5. Individual recovery profiles in basketball players.

    Science.gov (United States)

    Moreno, Jordi; Ramos-Castro, Juan; Rodas, Gil; Tarragó, Joan R; Capdevila, Lluís

    2015-01-01

    In the sport context, recovery has been characterized as a multifactor process (physiological, psychological, behavioral, social, etc.). This study takes a multidisciplinary approach to find psychophysiological markers of the stress-recovery process. It aims to determine how athletes' specific recovery actions relate to their perceptions of recovery, and Heart Rate Variability (HRV). A total of 196 assessments were analyzed from 6 players on a men's professional basketball team within the Liga LEB Oro basketball federation (2012/2013 season). Perceptions of recovery, recovery strategies, and HRV were recorded. The results show a pattern of individual differences in behavior related to athletes' recovery actions and HRV profiles throughout the season (p < .05). Moreover, we observed that each player had different recovery needs. In light of these results, we suggest an individualistic approach to evaluating and monitoring recovery to attend more accurately to each player's recovery needs.

  6. Fault Predictive Control of Compact Disk Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Wickerhauser, Mladen Victor

    2006-01-01

    Optical disc players such as CD-players have problems playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in the servo controller which positions the optical pick-up, such that the laser beam is focused on the information track. A scheme handling ...... of the feature based control scheme, such that a prediction step is included. The proposed scheme is compared with the feature based control scheme, in the perspective of handling surface faults, by simulations. These simulations show the improvements given by the proposed algorithm....

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

    Science.gov (United States)

    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 football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. PMID:25060072

  8. DMPD: TLR3 in antiviral immunity: key player or bystander? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16027039 TLR3 in antiviral immunity: key player or bystander? Schroder M, Bowie AG.... Trends Immunol. 2005 Sep;26(9):462-8. (.png) (.svg) (.html) (.csml) Show TLR3 in antiviral immunity: key pl...ayer or bystander? PubmedID 16027039 Title TLR3 in antiviral immunity: key player or bystander? Authors Schr

  9. Match analysis and player characteristics in rugby sevens.

    Science.gov (United States)

    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

  10. Exploring Team Passing Networks and Player Movement Dynamics in Youth Association Football

    Science.gov (United States)

    Coutinho, Diogo; Santos, Sara; Lago-Penas, Carlos; Jiménez, Sergio; Sampaio, Jaime

    2017-01-01

    Understanding how youth football players base their game interactions may constitute a solid criterion for fine-tuning the training process and, ultimately, to achieve better individual and team performances during competition. The present study aims to explore how passing networks and positioning variables can be linked to the match outcome in youth elite association football. The participants included 44 male elite players from under-15 and under-17 age groups. A passing network approach within positioning-derived variables was computed to identify the contributions of individual players for the overall team behaviour outcome during a simulated match. Results suggested that lower team passing dependency for a given player (expressed by lower betweenness network centrality scores) and high intra-team well-connected passing relations (expressed by higher closeness network centrality scores) were related to better outcomes. The correlation between the dyads’ positioning regularity and the passing density showed a most likely higher correlation in under-15 (moderate effect), indicating a possible more dependence of the ball position rather than in the under-17 teams (small/unclear effects). Overall, this study emphasizes the potential of coupling notational analyses with spatial-temporal relations to produce a more functional and holistic understanding of teams’ sports performance. Also, the social network analysis allowed to reveal novel key determinants of collective performance. PMID:28141823

  11. Exploring Team Passing Networks and Player Movement Dynamics in Youth Association Football.

    Science.gov (United States)

    Gonçalves, Bruno; Coutinho, Diogo; Santos, Sara; Lago-Penas, Carlos; Jiménez, Sergio; Sampaio, Jaime

    2017-01-01

    Understanding how youth football players base their game interactions may constitute a solid criterion for fine-tuning the training process and, ultimately, to achieve better individual and team performances during competition. The present study aims to explore how passing networks and positioning variables can be linked to the match outcome in youth elite association football. The participants included 44 male elite players from under-15 and under-17 age groups. A passing network approach within positioning-derived variables was computed to identify the contributions of individual players for the overall team behaviour outcome during a simulated match. Results suggested that lower team passing dependency for a given player (expressed by lower betweenness network centrality scores) and high intra-team well-connected passing relations (expressed by higher closeness network centrality scores) were related to better outcomes. The correlation between the dyads' positioning regularity and the passing density showed a most likely higher correlation in under-15 (moderate effect), indicating a possible more dependence of the ball position rather than in the under-17 teams (small/unclear effects). Overall, this study emphasizes the potential of coupling notational analyses with spatial-temporal relations to produce a more functional and holistic understanding of teams' sports performance. Also, the social network analysis allowed to reveal novel key determinants of collective performance.

  12. Temporal preparation in athletes: a comparison of tennis players and swimmers with sedentary controls.

    Science.gov (United States)

    Wang, Chun-Hao; Chang, Che-Chien; Liang, Yen-Ming; Shih, Chun-Ming; Muggleton, Neil G; Juan, Chi-Hung

    2013-01-01

    The authors aimed to investigate the effects of different sporting experience on nonspecific temporal preparation. They evaluated temporal preparation in tennis players (an open-skill sport) and their athletic (swimmers, a closed skill-sport) and nonathletic (sedentary students) controls using a go/no-go variable foreperiod paradigm in which one simple condition and two go/no-go conditions (central-go and mixed-go) were included, which can be used to study the temporal aspects of nonspecific preparation with decision making in inhibition with different levels of cognitive load. Tennis players responded faster than nonathletic controls while there was no significant difference relative to the athletic controls. Additionally, the main finding of the present study is that the difference in reaction time between tennis players and nonathletic controls was found selectively for short foreperiods in which temporal uncertainty is higher and less temporal preparation can occur. Moreover, correlation analysis revealed that superior temporal preparation was positively associated with enhanced go/no-go decision making in the higher difficulty condition. Our findings are consistent with tennis players showing superior temporal processing. The absence of a significant effect in athletic controls suggests that there is a specific benefit from tennis training and indicates that temporal preparation may be susceptible to modulation by fitness and appropriate training.

  13. Kinematic and kinetic characteristics of vertical jump: comparison between soccer and basketball players

    Directory of Open Access Journals (Sweden)

    Matheus Machado Gomes

    2009-09-01

    Full Text Available The aim of this study was to compare jump height and kinetic and kinematic com-ponents of countermovement vertical jumps between soccer and basketball players performed in two different arm swing conditions: with arm swing (WAS and without arm swing (NAS. Nine basketball players (21.2 ± 2.9 years; 101.64 ± 14.58 kg; 1.95 ± 0.06 m and nine soccer players (18.2 ± 0.7 years; 77.4 ± 7.58 kg; 1.81 ± 0.07 m performed 12 maximal countermo-vement vertical jumps, including 6 WAS jumps and 6 NAS jumps, on a force platform that recorded the ground reaction force (GRF. The vertical component of the GRF was used to estimate jump height and to calculate the kinematic (duration of eccentric phase, duration of concentric phase, and maximal downward displacement of center of mass and kinetic variables (mean power during the eccentric phase, mean power during the concentric, peak power, and peak force. The results showed no differences in jump height or in kinematic or kinetic variables between basketball and soccer players. In addition, the results showed that the participants of the two groups jumped higher in the WAS condition (0.41 m than in the NAS condition (0.36 m because of a higher peak power (WAS=276.8 W/kg0.67 and NAS=241.3 W/kg0.67 and a longer concentric phase duration (WAS=0.20 s/m0.5 and NAS=0.19 s/m0.5 during WAS jump. These results indicate that the basketball and soccer players studied here showed similar performance and the same kinematic and kinetic pattern in maximal vertical jumps and were comparably affected by the use of arm swing.

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

    Directory of Open Access Journals (Sweden)

    Brian Skinner

    Full Text Available 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.

  15. Physical qualities and activity profiles of sub-elite and recreational Australian football players.

    Science.gov (United States)

    Stein, Josh G; Gabbett, Tim J; Townshend, Andrew D; Dawson, Brian T

    2015-11-01

    To investigate the relationship between physical qualities and match activity profiles of recreational Australian football players. Prospective cohort study. Forty players from three recreational Australian football teams (Division One, Two and Three) underwent a battery of fitness tests (vertical jump, 10 and 40 m sprint, 6 m × 30 m repeated sprint test, Yo-Yo intermittent recovery level Two and 2-km time trial). The activity profiles of competitive match-play were quantified using 10-Hz Global Positioning System units. Division One players possessed greater maximum velocity, Yo-Yo level Two and 2-km time trial performances than Division Two and Three players. In addition, Division One players covered greater relative distance, and relative distances at moderate- and high-intensities during match-play than Division Two and Three players. Division Two players had better 2-km time trial performances than Division Three players. Positive associations (P football players competing at a higher level exhibit greater physical qualities and match-play activity profiles than lesser-skilled recreational players. Acceleration and maximum velocity, 2-km time trial and Yo-Yo level Two performances discriminate between players of different playing levels, and are related to physical match performance in recreational Australian football. The development of these qualities is likely to contribute to improved match performance in recreational Australian football players. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Translucent Players: Explaining Cooperative Behavior in Social Dilemmas

    Directory of Open Access Journals (Sweden)

    Valerio Capraro

    2016-06-01

    Full Text Available In the last few decades, numerous experiments have shown that humans do not always behave so as to maximize their material payoff. Cooperative behavior when non-cooperation is a dominant strategy (with respect to the material payoffs is particularly puzzling. Here we propose a novel approach to explain cooperation, assuming what Halpern and Pass call translucent players. Typically, players are assumed to be opaque, in the sense that a deviation by one player in a normal-form game does not affect the strategies used by other players. But a player may believe that if he switches from one strategy to another, the fact that he chooses to switch may be visible to the other players. For example, if he chooses to defect in Prisoner's Dilemma, the other player may sense his guilt. We show that by assuming translucent players, we can recover many of the regularities observed in human behavior in well-studied games such as Prisoner's Dilemma, Traveler's Dilemma, Bertrand Competition, and the Public Goods game.

  17. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  18. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  19. Kinanthropometric characteristics in teenager basketball players

    Directory of Open Access Journals (Sweden)

    Maria Abella del Campo

    2015-12-01

    Full Text Available Introduction: Basketball is a sport with a high heterogeneity anthropometric as playing position. Point guard is usually the lowest player but also the fastest. Guard is similar to point guard, faster and more agile than the others. Small forward has an intermediate height between the inside and outside players and it combines height with velocity. And center (pivot has a physical role, it has the highest and more muscle mass. The aim of this study is to describe the kinanthropometric profile of male cadet “Valencia Basket Club”. Material and Methods: A total of 20 male cadet basketball players were evaluated (15.35±0.59 years old. An anthropometrist level 1 took anthropometric measures according to the methodology of the International Society for the Advancement of Kinanthropometry (ISAK. Body composition was calculated according to the kinanthropometry consensus of the Kinanthropometry Spanish Group (GREC, somatotype with Heath-Carter’s method and adiposemuscular and cardiovascular risk index. Results: Differences in values of weight, height, skinfold and body composition from variables of sample and position were observed. Lower values were from point guard position and higher values were from center position. An increasing trend of these parameters was established in the following order: point guard, guard, small forward and center. Conclusions: The Valencia Basket Club cadet player overall somatotype is balance ectomorph. To know kinanthropometric profile may be beneficial to develop specific training and nutrition plans as well as to see evolution and characteristics for optimal performance

  20. Correlations of Back Strength with Selected Anthropometric Variables and Performance Tests in Indian Inter-University Male Field Hockey Players

    Directory of Open Access Journals (Sweden)

    S. Koley

    2017-01-01

    Full Text Available : The purpose of this study was of two-fold: first, to estimate the back strength of Indian inter-university male field hockey players and, second, to search the correlations of it with selected anthropometric variables and performance tests. To serve this purpose, a total of nine anthropometric variables, such as height, weight, body mass index, percent body fat, knee height, length of femur, femur biepicondylar diameter, skeletal mass and back strength, and two performance tests, such as sit and reach test and Slalom sprint and dribble test were measured on purposely selected 120 Indian inter-university male hockey players aged 18–25 years collected from the inter-university competition held in Guru Nanak Dev University, Amritsar, India during March, 2014. An adequate number of controls (n=119 were also taken from the same place for comparison. The results showed that the hockey players had the higher mean values in all the variables, except percent body fat and slalom sprint and dribble test than their control counterparts, showing statistically significant differences (p ≤ 0.003 – 0.001 between them. No significant correlations of back strength were found with any of the variables in Indian inter-university male field hockey players. In conclusion, it may be stated that back strength may not be used as one of the indicating factors for the performance of the field hockey players.

  1. Show Time

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> Story: Show Time!The whole class presents the story"Under the Sea".Everyone is so excited and happy.Both Leo and Kathy show their parentsthe characters of the play."Who’s he?"asks Kathy’s mom."He’s the prince."Kathy replies."Who’s she?"asks Leo’s dad."She’s the queen."Leo replieswith a smile.

  2. Snobbish Show

    Institute of Scientific and Technical Information of China (English)

    YIN PUMIN

    2010-01-01

    @@ The State Administration of Radio,Film and Television (SARFT),China's media watchdog,issued a new set of mles on June 9 that strictly regulate TV match-making shows,which have been sweeping the country's primetime programming. "Improper social and love values such as money worship should not be presented in these shows.Humiliation,verbal attacks and sex-implied vulgar content are not allowed" the new roles said.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Deborah L. Feairheller

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  6. The relationship between the piriformis muscle, low back pain, lower limb injuries and motor control training among elite football players.

    Science.gov (United States)

    Leung, Felix T; Mendis, M Dilani; Stanton, Warren R; Hides, Julie A

    2015-07-01

    Australian Football League (AFL) players have a high incidence of back injuries. Motor control training to increase lumbopelvic neuromuscular control has been effective in reducing low back pain (LBP) and lower limb injuries in elite athletes. Control of pelvic and femoral alignment during functional activity involves the piriformis muscle. This study investigated (a) the effect of motor control training on piriformis muscle size in AFL players, with and without LBP, during the playing season, and (b) whether there is a relationship between lower limb injury and piriformis muscle size. Stepped-wedge intervention. 46 AFL players participated in a motor control training programme consisting of two 30min sessions per week over 7-8 weeks, delivered across the season as a randomised 3 group single-blinded stepped-wedge design. Assessment of piriformis muscle cross-sectional area (CSA) involved magnetic resonance imaging (MRI) at 3 time points during the season. Assessment of LBP consisted of player interview and physical examination. Injury data were obtained from club records. An interaction effect for Time, Intervention Group and LBP group (F=3.7, p=0.03) was found. Piriformis muscle CSA showed significant increases between Times 1 and 2 (F=4.24, p=0.046), and Times 2 and 3 (F=8.59, p=0.006). Players with a smaller increase in piriformis muscle CSA across the season had higher odds of sustaining an injury (OR=1.08). Piriformis muscle size increases across the season in elite AFL players and is affected by the presence of LBP and lower limb injury. Motor control training positively affects piriformis muscle size in players with LBP. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Physical Characteristics and Performance of Japanese Top-Level American Football Players.

    Science.gov (United States)

    Yamashita, Daichi; Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

    2017-09-01

    Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455-2461, 2017-This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance.

  8. Physical Characteristics and Performance of Japanese Top-Level American Football Players

    Science.gov (United States)

    Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

    2017-01-01

    Abstract Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455–2461, 2017—This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance. PMID:28052052

  9. Online and live regular poker players: Do they differ in impulsive sensation seeking and gambling practice?

    Science.gov (United States)

    Barrault, Servane; Varescon, Isabelle

    2016-03-01

    Background and aims Online gambling appears to have special features, such as anonymity, speed of play and permanent availability, which may contribute to the facilitation and increase in gambling practice, potentially leading to problem gambling. The aims of this study were to assess sociodemographic characteristics, gambling practice and impulsive sensation seeking among a population of regular poker players with different levels of gambling intensity and to compare online and live players. Methods 245 regular poker players (180 online players and 65 live players) completed online self-report scales assessing sociodemographic data, pathological gambling (SOGS), gambling practice (poker questionnaire) and impulsive sensation seeking (ImpSS). We used SOGS scores to rank players according to the intensity of their gambling practice (non-pathological gamblers, problem gamblers and pathological gamblers). Results All poker players displayed a particular sociodemographic profile: they were more likely to be young men, executives or students, mostly single and working full-time. Online players played significantly more often whereas live players reported significantly longer gambling sessions. Sensation seeking was high across all groups, whereas impulsivity significantly distinguished players according to the intensity of gambling. Discussion Our results show the specific profile of poker players. Both impulsivity and sensation seeking seem to be involved in pathological gambling, but playing different roles. Sensation seeking may determine interest in poker whereas impulsivity may be involved in pathological gambling development and maintenance. Conclusions This study opens up new research perspectives and insights into preventive and treatment actions for pathological poker players.

  10. Competition and cooperation with virtual players in an exergame

    Directory of Open Access Journals (Sweden)

    Lindsay A. Shaw

    2016-10-01

    Full Text Available Two cross-sectional studies investigated the effects of competition and cooperation with virtual players on exercise performance in an immersive virtual reality (VR cycle exergame. Study 1 examined the effects of: (1 self-competition whereby participants played the exergame while competing against a replay of their previous exergame session (Ghost condition, and (2 playing the exergame with a virtual trainer present (Trainer condition on distance travelled and calories expended while cycling. Study 2 examined the effects of (1 competition with a virtual trainer system (Competitive condition and (2 cooperation with a virtual trainer system (Cooperative condition. Post exergame enjoyment and motivation were also assessed. The results of Study 1 showed that the trainer system elicited a lesser distance travelled than when playing with a ghost or on one’s own. These results also showed that competing against a ghost was more enjoyable than playing on one’s own or with the virtual trainer. There was no significant difference between the participants’ rated enjoyment and motivation and their distance travelled or calories burned. The findings of Study 2 showed that the competitive trainer elicited a greater distance travelled and caloric expenditure, and was rated as more motivating. As in Study 1, enjoyment and motivation were not correlated with distance travelled and calories burned. Conclusion Taken together, these results demonstrate that a competitive experience in exergaming is an effective tool to elicit higher levels of exercise from the user, and can be achieved through virtual substitutes for another human player.

  11. Isokinetic Strength Profile of Elite Female Handball Players

    Directory of Open Access Journals (Sweden)

    Xaverova Zuzana

    2015-12-01

    Full Text Available Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women’s Junior National Handball Team (JNT, n=8 or the Women’s National Handball Team (NT, n=9. The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric and 60°/s (eccentric. The Mann- Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02. However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

  12. Isokinetic Strength Profile of Elite Female Handball Players.

    Science.gov (United States)

    Xaverova, Zuzana; Dirnberger, Johannes; Lehnert, Michal; Belka, Jan; Wagner, Herbert; Orechovska, Karolina

    2015-12-22

    Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women's Junior National Handball Team (JNT, n=8) or the Women's National Handball Team (NT, n=9). The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric) and 60°/s (eccentric). The Mann-Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD) for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02). However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

  13. EROBATIC SHOW

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Visitors look at plane models of the Commercial Aircraft Corp. of China, developer of the count,s first homegrown large passenger jet C919, during the Singapore Airshow on February 16. The biennial event is the largest airshow in Asia and one of the most important aviation and defense shows worldwide. A number of Chinese companies took part in the event during which Okay Airways, the first privately owned aidine in China, signed a deal to acquire 12 Boeing 737 jets.

  14. Aerobic Fitness and Technical Efficiency at High Intensity Discriminate between Elite and Subelite Tennis Players.

    Science.gov (United States)

    Baiget, E; Iglesias, X; Rodríguez, F A

    2016-10-01

    The aim of this study was to determine whether selected physiological, performance and technical parameters derived from an on-court test are capable of discriminating between tennis players of national and international levels. 38 elite and subelite tennis players were divided into international level (INT, n=8) and national level players (NAT, n=30). They all performed a specific endurance field test, and selected physiological (maximum oxygen uptake [V˙O2max], and ventilatory thresholds [VT1 and VT2]), performance (test duration, final stage and hits per test) and technical (technical effectiveness [TE]) parameters were compared. INT showed greater V˙O2max, VO2 at VT2 (ml·kg(-1)·min(-1)), test duration (s), final stage (no.), hits per test (no.) and TE (% of successful hits), as compared with NAT (ptechnical parameters were the most discriminating factors. These results suggest that this specific endurance field test is capable of discriminating between tennis players at national and international levels, and that the better aerobic condition of the INT is associated with better technical efficiency at higher exercise intensities.

  15. Soccer skill development in talented players.

    Science.gov (United States)

    Huijgen, B C H; Elferink-Gemser, M T; Ali, A; Visscher, C

    2013-08-01

    The aim of the study was to gain insight into the development of soccer-specific skills and whether differences between talented players exist on the Loughborough Soccer Passing Test (LSPT). Two scores were derived from the LSPT: 1) execution time: time to complete 16 passes (speed) and 2) skill performance time: execution time including bonus and penalty time for accuracy. The study consisted of 2 parts, the first of which incorporated a quasi-longitudinal design with 270 talented players aged 10-18 years performing the LSPT (661 measurement occasions); multilevel modelling was applied. Secondly, differences between those players allowed to continue in the development program (selected, n=269) and players who were forced to leave (de-selected, n=50) were investigated using independent sample t-tests. The longitudinal data showed that the predicted execution time (i. e., speed) improved approximately 18% from age 10-18 years (Pskill performance time (i. e., combination of speed and accuracy) was predicted to improve approximately 32% (Pskill performance time (P0.05). In conclusion, in high-level youth soccer, the combination of speed and accuracy in soccer skills might be more important than speed alone. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Comparison of anthropometric parameters among Iranian and Spanish water polo players

    Directory of Open Access Journals (Sweden)

    Pooya Nekooei

    2016-06-01

    Full Text Available The purpose of this study was to compare the anthropometric parameters between Iranian and Spanish water polo national team players. Material and Methods ― The research was conducted in the physiological laboratory of Isfahan Azad University. Participants who participate in this study were 44 male national water polo players (22 Iranian and 22 Spanish, age 22±2 years old (Mean±SD. For the aim of this study twenty anthropometric parameters that was more important for water polo was measured and analysis. All the parameters were measured base on the international standard of anthropometric parameters (International Society for the Advancement of Kinanthropometry – ISAK. For analysis data, normal distribution of the data was proved by Kolmogorov-Smirnov test and then comparison between two groups was done by t-test. Results ― The results showed a significant difference in seven anthropometric parameters contain body fat percentage (P=0.031, biliocristal breadth (P<0.001, wrist breadth (P<0.001, chest girth (P=0.021, mid-thigh girth (P=0.019, palm length (P<0.001 and height (P=0.032. Conclusion ― Spanish players with relatively higher underlying levels of anthropometric parameters compare to Iranian water polo players had stronger ability to control the ball with the bigger palm and bigger wrist breadth, also they had stronger ability to do water vertical jump, cause of higher value of biliocristal breadth and mid-thigh girth and also stronger throwing the ball because of bigger muscle on their chest part of their body. However, Base on this study, having longer hands, more muscular body than fat and taller stature is an advantage for the players because it is considered to be a useful parameter in water polo.

  17. Somatotype and body composition analysis of Korean youth soccer players according to playing position for sports physiotherapy research.

    Science.gov (United States)

    Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Park, Byoung-Sun; Yang, Seung-Min; Jeon, Hye-Joo; Lee, Won-Deok; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-04-01

    [Purpose] The purpose of this study was to investigate the somatotype and physical characteristic differences among elite youth soccer players. [Subjects and Methods] In the present study, we evaluated twenty-two Korean youth soccer players in different playing positions. The playing positions were divided into forward (FW), midfielder (MF), defender (DF), and goalkeeper (GK). The participants' lean body mass (LBM), fat free mass (FFM), fat mass (FM), and basal metabolic rate (BMR) were measured and their somatotype determined according to the Heath-Carter method. [Results] The youth soccer players had twelve ectomorphic, eight mesomorphic, and two central predominant types. The DFs were taller than, but otherwise similar in physical characteristics to the FWs and MFs. The GKs were taller and heavier than the other players; however, their somatotype components were not significantly different. LBM, FFM, and BMR were significantly higher in GKs than in FWs and MFs. Although LBM, FFM, and BMR values between GKs and DFs showed large differences, they were not statistically significant. [Conclusion] The present study may contribute to our understanding of the differences in somatotype and body composition of Korean youth soccer players involved in sports physiotherapy research.

  18. Stress-stability and its influence on efficiency of competition activity of hockey players of high class

    Directory of Open Access Journals (Sweden)

    Andrey Mikhnov

    2014-10-01

    Full Text Available Purpose: to define the level of stress-stability of hockey players of high class and expose his influence on efficiency of competition activity of sportsmen. Materials and Methods: sixteen sportsmen of high class, taking part in the matches of the Kontinental hockey league (KXL for a club «Atlas» (Moscow obl. in a season 2013–2014, took part in researches The level of stress-stability of hockey players and his influence was analysed on efficiency of competition activity of sportsmen. Methods were used: pedagogical supervisions and analysis of competition activity, psychological testing, analysis of data of the special scientific-methodical literature, an analysis of data is the Internet, methods of mathematical statistics. Results: it is set in researches, that the hockey players of high class have a moderate level of personality and situation anxiety, high motivation to success and propensity to the risk. Correlation analysis showed that the level of stress resistance affects the efficiency of hockey players technical and tactical actions in the game. What below for sportsmen the level of stress was marked, the higher there were indexes of the neglected pucks and effective transmissions in a match (r=–0,583, –0,542. Conclusions: the level of stress-stability of hockey players of high class influences on efficiency of competition activity of sportsmen. Can be drawn on the exposed results for the correction of psychological preparedness of sportsman.

  19. Vitamin D profile in National Football League players.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  1. Relations of competitive state anxiety and efficacy of young volleyball players.

    Science.gov (United States)

    Milavić, Boris; Jurko, Damir; Grgantov, Zoran

    2013-05-01

    With the aim of validating the Competitive State Anxiety Inventory on a population of young Croatian volleyball players, 286 examinees, 106 male and 180 female volleyball players (average age of 16.09+/-1.83), filled out the CSAI-2, constructed by Martens, Vealey, Burton, Bump and Smith (1990)1. Given the fact that all scales of the Competitive State Anxiety Inventory have good homogeneity, reliability and sensitivity, it can be concluded that they represent high-quality measuring instruments for measuring psychological characteristics of young volleyball players. Young male and female volleyball players generally have a moderate level of self-confidence, and their cognitive anxiety is more prominent that somatic anxiety. In order to determine the age and gender differences in somatic and cognitive anxiety and self-confidence, parametric analysis of differences was performed and coefficients of the independent samples t-test were calculated. By analysis of differences according to age, it has been established that female junior players, in relation to female youth players, express a significantly lower level of somatic and cognitive anxiety and a significantly higher level of self-confidence. As opposed to female players, male youth and junior players do not differ in any of the analysed variables. By analysis of differences according to gender, it has been established that male youth players have a significantly higher level of self-confidence in comparison to female youth players. No significant differences were found in the level of competitive anxiety and self-confidence by analysis of variance between different player roles. No significant differences were found by discriminant analysis in somatic and cognitive anxiety, and self-confidence of female volleyball players of different situational efficacy. The group of least efficient male volleyball players is characterized by a very low level of self-confidence, while the most efficient group of volleyball

  2. Adaptivity to Age, Gender, and Gaming Platform Topology in Physical Multi-Player Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Friðriksson, Rafn Vídalín; Björnsson, Davíð Þór

    2012-01-01

    In games where players are competing against each other, it can be of interest to ensure that all players are challenged according to their individual skills. In order to investigate such adaptivity to the individual player in physical multi-player games, we developed a game on modular interactive...... tiles which can be used in both single-player and multi-player mode. We implemented simple adaptivity methods and tested these with different user groups including children and adults of both genders. The results show statistically significant differences in the game interactions between children...... and adults, and between male and female players. Also, results show statistically significant differences in the game interactions between different physical set-ups of the modular interactive tiles, i.e. the interaction depended on the topology of the modular tiles set-up. Changing the physical set...

  3. Multi-Player Quantum Games

    CERN Document Server

    Benjamin, S C; Benjamin, Simon C.; Hayden, Patrick M.

    2001-01-01

    Game theory is a mature field of applied mathematics. It formalizes the conflict between competing agents, and has found applications ranging from economics through to biology. Recently the first efforts have been made to introduce quantum information into game theory. For two-player games, it has been found that when the allowed `moves' are extended to include everything quantum mechanically possible, then the predominant strategies in the game can disappear, and only reappear if the players degrade the quantum coherence. Here we present the first study of quantum games with more than two players. We demonstrate that such games can exhibit `coherent' equilibrium strategies which have no analogue in classical games, or even in two-player quantum games. These equilibria are generally of a cooperative nature: quantum players can exploit their environment highly efficiently through the use of collaborative strategies.

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

    Science.gov (United States)

    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.

  5. EXAMINATION OF THE RELATIONSHIP BETWEEN OCCUPATIONAL BURNOUT AND JOB SATISFACTION OF PROFESSIONAL FOOTBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Hakkı

    2014-04-01

    Full Text Available The aim of the study is to examine the relationship between occupational burnout and job satisfaction levels of professional football players. Data was collected in 2011–2012 football seasons. 79 players from Turkey's Super League, 90 players from first, 135 football players from second and 112 football players from third division; totally 416 football players participated. “Burnout Inventory" with 22 items, developed by Maslach (1981 and adapted to Turkish by Ergin (1992 was used. Minnesota Satisfaction Questionnaire 20 "- Short Form” developed by Weiss et al (1967 and adapted to Turkish by Baycan (1985 was used. SPSS was used for the analysis of the data. Super League football players general job satisfaction levels were significantly higher than 2nd and 3rd division football players. The burnout levels of Super League football players were significantly lower than the others. The occupation burnout and job satisfaction levels of football players have a negative relationship mutually ; while job satisfaction level increased, burnout levels of players reduced. Most remarkable part is that Midfielders have lower external satisfaction than goalkeepers.

  6. CAREER TRANSITION FROM JUNIOR TO SENIOR IN BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Alberto Lorenzo

    2009-01-01

    Full Text Available The purpose of the study was to investigate what factors affect basketball players in the transition from junior and amateur to senior and professional sport respectively. The study was a qualitative research which uses a semi-structured interview to get the data. There were interviewed five Spanish basketball players who were starting playing in a team of Basketball Club Association (C.B.A.. The results showed that the participants face several changes both in the sport and in the life outside sport. At the same time, the results indicated the existence of several coping strategies that help the player in his career transition.

  7. Physical and Physiological Demands of Experienced Male Basketball Players During a Competitive Game.

    Science.gov (United States)

    Puente, Carlos; Abián-Vicén, Javier; Areces, Francisco; López, Roberto; Del Coso, Juan

    2017-04-01

    Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological demands of experienced male basketball players during a competitive game. J Strength Cond Res 31(4): 956-962, 2017-The aim of this investigation was to analyze the physical and physiological demands of experienced basketball players during a real and competitive game. Twenty-five well-trained basketball players (8 guards, 8 forwards, and 9 centers) played a competitive game on an outdoor court. Instantaneous running speeds, the number of body impacts above 5 g, and the number of accelerations and decelerations were assessed by means of a 15-Hz global Positioning System accelerometer unit. Individual heart rate was also recorded using heart rate monitors. As a group mean, the basketball players covered 82.6 ± 7.8 m·min during the game with a mean heart rate of 89.8 ± 4.4% of maximal heart rate. Players covered 3 ± 3% of the total distance running at above 18 km·h and performed 0.17 ± 0.13 sprints per minute. The number of body impacts was 8.2 ± 1.8 per minute of play. The running pace of forwards was higher than that of centers (86.8 ± 6.2 vs. 76.6 ± 6.0 m·min; p ≤ 0.05). The maximal speed obtained during the game was significantly higher for guards than that for centers (24.0 ± 1.6 km·h vs. 21.3 ± 1.6 km·h; p ≤ 0.05). Centers performed a lower number of accelerations/decelerations than guards and forwards (p ≤ 0.05). In conclusion, the extraordinary rates of specific movements performed by these experienced basketball players indicate the high physiological demands necessary to be able to compete in this sport. The centers were the basketball players who showed lower physiological demands during a game, whereas there were no differences between guards and forwards. These results can be used by coaches to adapt basketball training programs to the specific demands of each playing position.

  8. Prisoner's Dilemma Applied and in the Classroom: The TV Game Show "Friend or Foe"

    Science.gov (United States)

    Coe, Paul R.; Alonzi, Loreto Peter; Condon, Daniel; Butterworth, William T.

    2007-01-01

    Prisoner's Dilemma is a common game theory scenario in which two players must choose between acting cooperatively or out of pure self-interest. What a player decides affects not only his own outcome but also that of the other player. "Friend or Foe," a TV game show that has appeared on the cable Game Show Network (GSN), places pairs of contestants…

  9. Validity of the V-cut Test for Young Basketball Players.

    Science.gov (United States)

    Gonzalo-Skok, O; Tous-Fajardo, J; Suarez-Arrones, L; Arjol-Serrano, J L; Casajús, J A; Mendez-Villanueva, A

    2015-11-01

    The aim of the present study was to assess the reliability, usefulness, validity, age-related differences and responsiveness of a 25- m side-step cutting maneuver test (V-cut test). Fifty young male basketball players performed the V-cut test on 2 occasions separated by 5-7 days to assess test-retest reliability and determine a priori usefulness. Twenty subjects also completed both the L-Run and 505 test to analyze the possible relationships among these 3 tests. Furthermore, 33 players performed the V-cut test 4 times throughout the season to analyze responsiveness. Finally, 53 players (U-14 to U-20) were assessed in the V-cut test to examine the age-related differences. Reliability scores showed high intraclass correlation coefficient (ICC=0.90) and low coefficient of variation (CV=1.4%). The responsiveness of the V-cut test was good, as the typical short- (1.5-1.7%), mid- (1.6-3.1%) and long-term (3.3%) changes in V-cut performance were higher than the CV. Low (r=0.64; CL90%: 0.34; 0.82) to moderate (r=0.76; CL90%: 0.53; 0.88) relationships were found between the V-cut test with the 505 and L-Run test, respectively. Age-related differences analysis showed better V-cut test performance as age increased in adolescent basketball players. The V-cut test is reliable to assess change of direction ability (CODA) and it could be used to monitor CODA in adolescent basketball players.

  10. Anthropometric Characteristics of Spanish Professional Basketball Players

    Directory of Open Access Journals (Sweden)

    Vaquera Alejandro

    2015-06-01

    Full Text Available The study of elite basketball players’ anthropometric characteristics alongside those of body composition contributes significantly to their profiling as professional athletes and plays an important role in the selection process, as these characteristics can have a significant impact on performance. In the current study, 110 professional basketball players from a series of Spanish professional Leagues (ACB, LEB and EBA and youth level National Teams (U20 and U18 had their anthropometric profiles measured and compared to determine differences between them. Furthermore, all 110 players were divided into three different categories according to their playing position: guards, forwards and centres. The results obtained show no significant differences between players in different competitions in weight, height and the sum of skinfolds. Nonetheless, there were several differences related to body fat content (13.03% in ACB players and 10.52% in the lower categories and National Teams. There were also several differences found between the different playing positions amongst all playing levels in body mass (79.56 ± 2.41, 91.04 ± 1.51 and 104.56 ± 1.73 kg, height (182.28 ± 0.96, 195.65 ± 1.00 and 204.08 ± 0.67 cm, skinfold distribution and perimeters. However, there were no significant differences in body fat content between the different playing positions. The conclusions obtained from this study provide a better understanding to basketball specialists regarding the selection process of players at the elite level, especially on the transition from youth elite programs to men’s elite leagues.

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

    Science.gov (United States)

    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.

  12. A Novel Music Player Controlling Design Based on Gesture Recognition

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2014-01-01

    Full Text Available This study has proposed a novel music player controlling method based on gesture recognition, which translating the gesture interacting signal into a controlling instruction for the music player. Firstly, utilizing the laptop’s webcam to capture the image information, and then employing the image processing method to tackle it. The skin color detection was used to obtain the information of gesture candidates, and a background subtraction was introduced to eliminate the distributing information. Moreover, in order to ensure the rapid and effective implementation of music player proposed here, the barycenter of a gesture was calculated as one Recognized Reference Information (RRI; a ratio between the gesture’s width and height was also selected as the other RRI; the comparison of these two RRI values was utilized to obtain a pattern signal of the gesture which was corresponding to the controlling instruction for the Music Player. Eventually, a Music Player was programmed and the pattern signal generated by gesture recognition was used to control the Music Player as willing to realize four basic functions: “play”, “pause”, “previous” and “next”. A series of tests using our gesture recognition based Music Player was conducted under the condition with different kinds of complex backgrounds, and the results showed the satisfactory performance of our interactive designing.

  13. SUPERSTITIOUS BEHAVIOR AMONG JUDO, TAEKWONDO AND BOXING PLAYERS

    Directory of Open Access Journals (Sweden)

    Gaurav Dureja

    2016-04-01

    Full Text Available Purpose: The present study was designed to measure superstitious behavior among Judo, Taekwondo and Boxing players. Material: Thirty (N=30 male inter-college level players with the age group of 19-25 years were selected through purposive sampling technique to act as subjects from affiliated colleges of Panjab University, Chandigarh. They were further divided into three groups: Group-A [Judo (n=10], Group-B [Taekwondo (n=10] and Group-C [Boxing (n=10]. One Way Analysis of Variance (ANOVA was applied to find out the differences among judo, taekwondo and boxing players. Where ‘F’ values found significant, Least Significant Differences (LSD Post-hoc test was applied to find out the direction and degree of difference. Results: The level of significance was set at 0.05. The result revealed significant differences among judo, taekwondo and boxing players on the sub parameters: clothing and appearance, preparation, team ritual and coach. However, no significant differences have been observed on the sub-parameters fetish, game/competition, prayer and parameter superstitious (Total. Conclusions: The obtained results showed significant differences on the sub-parameter Coach among Judo, Taekwondo and Boxing players. While calculating the mean values of entire groups, it has been observed that Boxing players demonstrate significantly better on the sub-parameter Coach. Therefore, it can be ascertained that Boxing players are more confident that coach bring a lucky charm to our game.

  14. The influence of somatotype components and personality traits on the playing position and the quality of top Croatian female cadet handball players.

    Science.gov (United States)

    Cavala, Marijana; Trninić, Viktorija; Jasić, Dajana; Tomljanović, Mario

    2013-05-01

    The research was conducted with the aim to establish the structure and the differences of morphological features and personality traits between different age groups of female cadet handball players grouped by their playing quality and playing positions. Further on, the research was done on 70 handball players aged 15, 31 on average, who were grouped according to their positions on goalkeepers, outside players, wings and pivots. Furthermore, according to the quality of playing, they were divided in two quality groups of players, those from the wider cadet national team, thus characterised as top female players in Croatia, and those who had never been invited into the cadet national team and thus can be referred to as low-quality, i.e. average female handball players. The structure of predictor variables has indicated the existence of general morphological factor assessing the players' constitution and two personality features factors - neuroticism and extraversion. The variance analysis showed no statistically significant differences of somatotype variables with relation to quality and playing position. By observing basic personality traits, a statistically significant difference was confirmed only in introversion-extraversion with a lower score in goalkeepers than in other positions, which indicates a higher level of introversion in this playing position. Such result was expected since this particular position abounds in specific tasks and demands in the game in relation to all other playing positions. Further on, it has been concluded that the selection of players must not be based only on the stated physical and psychological characteristics, but on relevant anthropological complexes determining performance and sport achievement.

  15. The Long-Term Game: An Analysis of the Life Expectancy of National Football League Players

    Directory of Open Access Journals (Sweden)

    Ruud Koning

    2014-03-01

    Full Text Available The National Football League (NFL has recently received significant negative media attention surrounding the safety of its players, revolving largely around the long term health risks of playing the sport. Recent premature deaths and instances of suicide associated with chronic traumatic encephalopathy and other football related injuries have brought the sport under increased scrutiny. By comparing mortality rates of the general population to mortality rates of players using publically available data from the 1970 and 1994 NFL seasons, we test whether participation in football is significantly harmful to the longevity of the players. We conclude that, in total, players in the NFL have lower mortality rates than the general population. However, there is evidence that line players have higher mortality rates than other players and that those who played more games have higher mortality rates than those who played fewer games.

  16. Hypoconnectivity and Hyperfrontality in Retired American Football Players

    Science.gov (United States)

    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.

  17. METABOLIC DEMANDS OF MATCH PERFORMANCE IN YOUNG SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Alper Aslan

    2012-03-01

    Full Text Available The aim of the present study was to determine metabolic responses, movement patterns and distance covered at running speeds corresponding to fixed blood lactate concentrations (FBLs in young soccer players during a match play. A further aim of the study was to evaluate the relationships between FBLs, maximal oxygen consumption (VO2max and distance covered during a game. A multistage field test was administered to 32 players to determine FBLs and VO2max. Blood lactate (LA, heart rate (HR and rate of perceived exertion (RPE responses were obtained from 36 players during tournament matches filmed using six fixed cameras. Images were transferred to a computer, for calibration and synchronization. In all players, values for LA and HR were higher and RPE lower during the 1st half compared to the 2nd half of the matches (p < 0.01. Players in forward positions had higher LA levels than defenders, but HR and RPE values were similar between playing positions. Total distance and distance covered in jogging, low-moderate-high intensity running and low intensity sprint were higher during the 1st half (p < 0.01. In the 1st half, players also ran longer distances at FBLs [p<0.01; average running speed at 2mmol·L-1 (FBL2: 3.32 ± 0.31m·s-1 and average running speed at 4mmol·L-1 (FBL4: 3.91 ± 0.25m·s-1]. There was a significant difference between playing positions in distance covered at different running speeds (p < 0.05. However, when distance covered was expressed as FBLs, the players ran similar distances. In addition, relationships between FBLs and total distance covered were significant (r = 0.482 to 0.570; p < 0.01. In conclusion, these findings demonstrated that young soccer players experienced higher internal load during the 1st half of a game compared to the 2nd half. Furthermore, although movement patterns of players differed between playing positions, all players experienced a similar physiological stress throughout the game. Finally, total

  18. Anthropometric profile, vertical jump, and throwing velocity in elite female handball players by playing positions.

    Science.gov (United States)

    Vila, Helena; Manchado, Carmen; Rodriguez, Nuria; Abraldes, José Arturo; Alcaraz, Pedro Emilio; Ferragut, Carmen

    2012-08-01

    Women's handball is a sport, which has seen an accelerated development over the last decade. Although anthropometric and physical characteristics have been studied for male sports teams, in women's handball, studies are scarce. The aim of this study was twofold: first, to describe the anthropometric characteristics, throwing velocity, hand grip, and muscular power of the lower limbs in female handball players and second, to identify the possible differences in these parameters in terms of individual playing positions (center, back, wing, pivot, and goalkeeper). A total of 130 elite female Spanish handball players participated in the study (age 25.74 ± 4.84 years; playing experience 14.92 ± 4.88 years). Anthropometric assessment was performed for all the subjects following the International Society for the Advancement of Kinanthropometry protocols. Furthermore, all the subjects performed a vertical jump test (squat jump and countermovement jump). Hand grip and throwing velocity in several situations were also assessed. A 1-way analysis of variance and a Tukey post hoc test were used to study the differences among individual playing positions. Wings were less heavy, shorter, and showed a smaller arm span than did goalkeepers, backs and pivots (p ≤ 0.001). Additionally, pivots were heavier than centers. Backs and pivots exhibited higher muscular mass than did wings. Total players' somatotype was mesomorphy endomorphy (3.89-4.28-2.29). Centers showed higher throwing velocity levels than did wings in 9-m throws from just behind the line, with a goalkeeper. Backs exhibited higher hand-grip values than did wings. Statistical differences have been established between wings and other specific playing positions, especially with pivot and backs. Coaches can use this information to select players for the different specific positions.

  19. The role of community in the development of elite handball and football players in Denmark.

    Science.gov (United States)

    Rossing, N N; Nielsen, A B; Elbe, A-M; Karbing, D S

    2016-01-01

    The primary purpose of this study was to investigate the effect of the place of early development in a sample of Danish male elite and youth handball and football players. The sample included 366 handball and football players from the elite Danish league in the season 2011-2012 and a comparison sample of youth players under the age of 12 from 2003, including 147,221 football and 26,290 handball players. Odds ratio analysis showed that both population size and density significantly affected the proportional number of youth players per community and the odds of athletes reaching an elite level in football and handball. The odds for youth player registrations in both handball and football increased in rural in contrast to urban communities. However, elite football players primarily came from communities of high density (>1000 pop./km(2)), whereas elite handball players primarily came from less densely populated communities (100 to <250 pop./km(2)). Furthermore, there seems to be a relation between representation of elite and talent clubs in different communities and the probability of becoming an elite player in both sports. The limited number of elite players in both sports from rural communities may be due to national talent development strategies that do not incorporate development support for clubs in rural areas. Additionally, the results of the study clearly suggest the need to include the youth player population to advance research findings in birthplace effect studies.

  20. The strategy of players on the European gas market

    Energy Technology Data Exchange (ETDEWEB)

    Lecarpentier, A

    2006-07-01

    One result of opening up the European gas market to competition has been to increase the number and diversity of the players involved, whether producers, suppliers or electric utilities. However, while the gas on offer is still controlled by a handful of market players given the increasing importance of state-owned companies from exporting countries outside Europe, the downstream gas sector continues to show a strong concentration of incumbent operators seeking a dominant position in the supply of gas. (author)

  1. Managing player load in professional rugby union: a review of current knowledge and practices.

    Science.gov (United States)

    Quarrie, Kenneth L; Raftery, Martin; Blackie, Josh; Cook, Christian J; Fuller, Colin W; Gabbett, Tim J; Gray, Andrew J; Gill, Nicholas; Hennessy, Liam; Kemp, Simon; Lambert, Mike; Nichol, Rob; Mellalieu, Stephen D; Piscione, Julien; Stadelmann, Jörg; Tucker, Ross

    2017-03-01

    The loads to which professional rugby players are subjected has been identified as a concern by coaches, players and administrators. In November 2014, World Rugby commissioned an expert group to identify the physical demands and non-physical load issues associated with participation in professional rugby. To describe the current state of knowledge about the loads encountered by professional rugby players and the implications for their physical and mental health. The group defined 'load' as it relates to professional rugby players as the total stressors and demands applied to the players. In the 2013-2014 seasons, 40% of professional players appeared in 20 matches or more, and 5% of players appeared in 30 matches or more. Matches account for ∼5-11% of exposure to rugby-related activities (matches, team and individual training sessions) during professional competitions. The match injury rate is about 27 times higher than that in training. The working group surmised that players entering a new level of play, players with unresolved previous injuries, players who are relatively older and players who are subjected to rapid increases in load are probably at increased risk of injury. A mix of 'objective' and 'subjective' measures in conjunction with effective communication among team staff and between staff and players was held to be the best approach to monitoring and managing player loads. While comprehensive monitoring holds promise for individually addressing player loads, it brings with it ethical and legal responsibilities that rugby organisations need to address to ensure that players' personal information is adequately protected. Administrators, broadcasters, team owners, team staff and the players themselves have important roles in balancing the desire to have the 'best players' on the field with the ongoing health of players. In contrast, the coaching, fitness and medical staff exert significant control over the activities, duration and intensity of training

  2. Cavum Septum Pellucidum in Retired American Pro-Football Players.

    Science.gov (United States)

    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 (pfootball players compared with patients without a history of TBI.

  3. Caffeine supplementation and reactive agility in elite youth soccer players.

    Science.gov (United States)

    Jordan, J Bradley; Korgaokar, Ajit; Farley, Richard S; Coons, John M; Caputo, Jennifer L

    2014-05-01

    This study examined the effects of caffeine supplementation (6 mg·kg-1) on performance of a reactive agility test (RAT) in 17 elite, male, youth (M = 14 y) soccer players. Using a double-blind, repeated-measures design, players completed 4 days of testing on the RAT after a standardized warm-up. On day 1, anthropometric measurements were taken and players were accommodated to the RAT. On day 2, baseline performance was established. Caffeine or placebo conditions were randomly assigned on day 3 and the condition was reversed on day 4. Players completed 3 randomized trials of the RAT on days 2, 3, and 4 with at least 1 trial to the players' dominant and nondominant sides. There were no significant differences among conditions in reaction time (RT) to the dominant side, heart rates at any point of measurement, or ratings of perceived exertion (RPE) after completion of the warm-up. Caffeine produced faster RT to the nondominant side (P = .041) and higher RPE at the conclusion of the RAT (P = .013). The effect on the total time (TT) to complete the agility test to the nondominant side approached significance (P = .051). Sprint time and TT to either side did not differ. Caffeine supplementation may provide ergogenic benefit to elite, male, youth soccer players.

  4. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  5. The Astro Learning Design Player

    NARCIS (Netherlands)

    Sharples, Paul; Wilson, Scott; Popat, Kris; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, Paul Wilson, S., Popat, K., Griffiths, D., Beauvoir, P. (2009) The Astro Learning Design Player. This software is distributed under the three clause BSD license, copyright TENCompetence Foundation

  6. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  7. Left ventricular biomechanics in professional football players.

    Science.gov (United States)

    von Lueder, T G; Hodt, A; Gjerdalen, G F; Steine, K

    2017-04-04

    Chronic exercise induces adaptive changes of left ventricular (LV) ejection and filling capacities which may be detected by novel speckle-tracking echocardiography (STE) and tissue Doppler imaging (TDI)-based techniques. A total of 103 consecutive male elite Norwegian soccer players and 46 age-matched healthy controls underwent echocardiography at rest. STE was used to assess LV torsional mechanics and LV systolic longitudinal strain (LS). Diastolic function was evaluated by trans-mitral blood flow, mitral annular velocities by TDI, and LV inflow propagation velocity by color M-mode. Despite similar global LS, players displayed lower basal wall and higher apical wall LS values vs controls, resulting in an incremental base-to-apex gradient of LS. Color M-mode and TDI-derived data were similar in both groups. Peak systolic twist rate (TWR) was significantly lower in players (86.4±2.8 vs controls 101.9±5.2 deg/s, Pplayers (-124.5±4.2 vs -106.9±6.7 deg/s) and peaked earlier during the cardiac cycle (112.7±0.8 vs 117.4±2.4% of systole duration, both Pplayers. Augmented diastolic wall strain (DWS), a novel measure of LV compliance in players, was associated with improved myocardial mechanical efficiency. The described myocardial biomechanics may underlie augmented exertional cardiac function in athletes and may have a potential role to characterize athlete's heart by itself or to distinguish it from hypertensive or hypertrophic cardiomyopathy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. A characterization of 2-player mechanisms for scheduling

    CERN Document Server

    Christodoulou, George; Vidali, Angelina

    2008-01-01

    We study the mechanism design problem of scheduling unrelated machines and we completely characterize the decisive truthful mechanisms for two players when the domain contains both positive and negative values. We show that the class of truthful mechanisms is very limited: A decisive truthful mechanism partitions the tasks into groups so that the tasks in each group are allocated independently of the other groups. Tasks in a group of size at least two are allocated by an affine minimizer and tasks in singleton groups by a task-independent mechanism. This characterization is about all truthful mechanisms, including those with unbounded approximation ratio. A direct consequence of this approach is that the approximation ratio of mechanisms for two players is 2, even for two tasks. In fact, it follows that for two players, VCG is the unique algorithm with optimal approximation 2. This characterization provides some support that any decisive truthful mechanism (for 3 or more players) partitions the tasks into gro...

  9. Macro-players in stock markets

    CERN Document Server

    Röhner, B M

    2005-01-01

    It is usually assumed that stock prices reflect a balance between large numbers of small individual sellers and buyers. However, over the past fifty years mutual funds and other institutional shareholders have assumed an ever increasing part of stock transactions: their assets, as a percentage of GDP, have been multiplied by more than one hundred. The paper presents evidence which shows that reactions to major shocks are often dominated by a small number of institutional players. Most often the market gets a wrong perception and inadequate understanding of such events because the relevant information (e.g. the fact that one mutual fund has sold several million shares) only becomes available weeks or months after the event, through reports to the Securities and Exchange Commission (SEC). Our observations suggest that there is a radical difference between small ($ 5% $) price changes which, on the contrary, may be caused by massive sales (or purchases) by a few players. This suggests that the mechanisms which a...

  10. Evolutionary game theory: molecules as players.

    Science.gov (United States)

    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.

  11. ASSESSMENT OF ANAEROBIC THRESHOLD IN FOOTBALL PLAYERS ON DIFFERENT POSITIONS, USING THE CONCONI TEST

    Directory of Open Access Journals (Sweden)

    Milan Cvetković

    2014-06-01

    results, no statistically significant difference was observed. Discriminant analysis, which is a superior method compared to multivariate analysis of variance, because in addition to the quantitative values of the analyzed features it also observes their mutual relationship, revealed no significant difference also. Univariate analysis confirmed the assumption, which means no significant differences were found between the groups regarding the observed variables. However, the mean values for midfield players in all monitored parameters were the highest. Discussion: The results of this study indicate similar estimates of values of the anaerobic threshold between the groups divided according to their playing position. However, the mean values for midfield players in all monitored parameters were the highest: heart rate at the anaerobic threshold (186.36 beats/min, running speed at anaerobic threshold (14.07 km/h and percentage value of anaerobic threshold in relation to the maximum heart rate (92.07 %, which separates them from other playing positions and points to the existence of certain differences. Comparing the results of this study with research performed by Dillerna et al. (2012 shows that similar results were obtained, and the best results are achieved by female midfield players. Also, by measuring heart rate during official games, Coelho et al. (2011, within the sample of 26 players from U-17 and 18 players from U-20 category, found that midfield players, presented in percentage, spent the most of the time in the zone 3 (p<0.05, and spent more time in zone 4 compared to the forward players and center-backs (p<0.05. The above studies indicate a significantly higher engagement of midfield players compared to other positions. References: Coelho BD, Mortimer AL, Condessa AL, Morandi FR, Oliveira MB, Marins JC, Soares DD, arcia SE (2011. Rev. Bras. Cineantropom Desempenho Hum., 13 (5, 341-7. Conconi F, Grazzi G, Casoni I, Borsseto C, Ballarin E, Mazzoni G, Gatracchini M

  12. Analysis of player's in-game performance vs rating: Case study of Heroes of Newerth

    CERN Document Server

    Caplar, Neven; Matijasevic, Maja

    2013-01-01

    We evaluate the rating system of "Heroes of Newerth" (HoN), a multiplayer online action role-playing game, by using statistical analysis and comparison of a player's in-game performance metrics and the player rating assigned by the rating system. The datasets for the analysis have been extracted from the web sites that record the players' ratings and a number of empirical metrics. Results suggest that the HoN's Matchmaking rating algorithm, while generally capturing the skill level of the player well, also has weaknesses, which have been exploited by players to achieve a higher placement on the ranking ladder than deserved by actual skill. In addition, we also illustrate the effects of the choice of the business model (from pay-to-play to free-to-play) on player population.

  13. Protective equipment and player characteristics associated with the incidence of sport-related concussion in high school football players: a multifactorial prospective study.

    Science.gov (United States)

    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 football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. © 2014 The Author(s).

  14. The Relative Age Effect and Physical Fitness Characteristics in German Male Tennis Players

    Directory of Open Access Journals (Sweden)

    Alexander Ulbricht, Jaime Fernandez-Fernandez, Alberto Mendez-Villanueva, Alexander Ferrauti

    2015-09-01

    Full Text Available The aims of the study were to test: 1 whether the relative age effect (RAE was prevalent in young (U12-U18 German male tennis players; 2 the potential influence of age and/or skill level on RAE and 3 whether maturity, anthropometric and fitness measures vary according to birth date distribution in elite youth tennis players. For the present study the following male populations were analysed: Overall German population (n = 3.216.811, all players affiliated to the German Tennis Federation (DTB (n = 120.851, players with DTB official ranking (n = 7165, regional (n = 381 and national (n = 57 squads (11-17 years old, as well as the top 50 German senior players were analyzed. RAEs were more prevalent at higher competitive levels with more players born in the first quarter of the year compared with the reference population for ranked (29.6%, regional (38.1% and national (42.1% players. No systematic differences were found in any of the maturity, anthropometric and fitness characteristics of the regional squad players born across different quarters. RAEs are present in the DTB competitive system and it was more pronounced at higher competitive levels. Compared with early born, late born players who were selected into elite squads did not differ in maturation, anthropometric and fitness characteristics.

  15. Lack of blood pressure difference by race in professional American football players.

    Science.gov (United States)

    Tucker, Andrew M; Lincoln, Andrew E; Vogel, Robert A; Black, Henry R; Dunn, Reginald E; Wilson, Peter W F; Pellman, Elliot J

    2015-05-01

    Previous findings suggest that professional American football players have higher blood pressures (BP) and a higher prevalence of pre-hypertension and hypertension than the general population. We sought to determine whether race is associated with differences in BP and prevalence of pre-hypertension and hypertension among a large sample of professional football players. BP was measured at 2009 team mini-camps for 1484 black (n = 1007) and white (n = 477) players from 27 National Football League (NFL) teams. Players were categorized into three position groups based on body mass index (BMI). There was no racial difference in mean systolic or diastolic BP in any of the three position groups. There were no racial differences in prevalence of hypertension (99 [9.8%] black players vs. 39 [8.2%] white players; P = .353) or pre-hypertension (557 [55.3%] black players vs. 264 [55.3%] white players; P = 1.0). Contrary to findings in the general population, BP and prevalence of pre-hypertension/hypertension did not vary with race in a large population of active NFL players.

  16. Physical and physiological attributes of female volleyball players--a review.

    Science.gov (United States)

    Lidor, Ronnie; Ziv, Gal

    2010-07-01

    The main objective of this article was to review a series of studies (n = 31) on physical attributes, physiological attributes, and on-court performances of female volleyball players. Empirical and practical knowledge emerging from studies on training-related issues in volleyball, such as body mass, fat-free mass, aerobic profile, strength, and agility and speed, should be integrated and applied when planning annual training programs for volleyball players. Based on our review, it was found that (a) players of a higher skill level are taller, somewhat heavier, and have higher vertical jump values than players of a lower level; (b) the aerobic profile of female volleyball players is similar to that of female basketball players; (c) ballistic resistance training can increase vertical jump values in female volleyball players; and (d) preseason conditioning should be conducted to prevent fatigue and reduced performance at the beginning of the season. Among the research concerns discussed in the article are that there is a lack data for on-court performance and time-motion analysis in female volleyball players and that more experimental/manipulative studies are needed to examine the effectiveness of different training programs on physiological attributes of female volleyball players. Two practical implications are suggested for volleyball and strength and conditioning coaches: (a) functional and nonfunctional overreaching should be carefully monitored when planning strength and conditioning programs, and (b) volleyball programs should include ballistic-type training.

  17. Anthropometric, body composition and somatotype characteristics of elite female volleyball players from the highest Spanish league.

    Science.gov (United States)

    Martín-Matillas, Miguel; Valadés, David; Hernández-Hernández, Elena; Olea-Serrano, Fátima; Sjöström, Michael; Delgado-Fernández, Manuel; Ortega, Francisco B

    2014-01-01

    This study aimed to describe morphological characteristics of elite female volleyball players from the highest Spanish league, with special focus on differences by performance level and playing positions. Nearly all female players playing in the highest Spanish volleyball league during season 2003/2004 participated in this study (N=148 elite players, 92% of the total). Anthropometric, body composition and somatotype parameters according to performance and playing positions were analysed. The players' characteristics were as follows; body mass 72.3 ± 8.4 kg; stature 179.8 ± 7.1 cm; body fat 24.0 ± 3.1% and skeletal muscle mass 27.3 ± 2.9 kg. Mean somatotype was 3.1 ± 0.7; 3.4 ± 0.9; 3.1 ± 0.9 characterised as central with a tendency to balanced mesomorph. Top level players (whose teams were better classified in the team performance ranking) were taller, had higher skeletal muscle mass and ectomorphy, and had a lower level of adiposity markers, compared with lower level players. Players selected for their respective National teams (individual performance) were taller, heavier, had higher muscle mass and lower endomorphy than non-selected players. Differences according to playing positions were found. This study provides a complete set of reference data on anthropometry, body composition and somatotype of elite female volleyball players. Morphological differences have been identified according to performance level and playing position.

  18. Protein intake and nitrogen balance in male non-active adolescents and soccer players.

    Science.gov (United States)

    Boisseau, N; Le Creff, C; Loyens, M; Poortmans, J R

    2002-12-01

    Recommendations for the requirements for protein intake amount usually to 0.8-1.0 g x kg(-1) body mass x day(-1) in adolescents without any reference to the undertaking of acute exercise or to the training status. The present investigation intended to determine the nitrogen balance and protein intake in 8 healthy male non-active adolescents and 11 adolescent soccer players, both groups aged about 15 years. An assessment of nutrient intake was obtained by analysing 7 day food records collected by a questionnaire. Nitrogen excretion rate was determined and nitrogen balance was calculated from the mean daily protein intake and the urinary excretion. The results showed that the nutritional status of the two groups was similar. Nevertheless, we found that their diets were quite inappropriate in terms of the intakes of carbohydrate, some minerals (zinc, calcium, magnesium), vitamins (A, B6, D) and fibre. A positive nitrogen balance was observed from a mean protein intake of 1.57 g x kg(-1) body mass x day(-1) in these adolescents, whether they were non-active or athletes. Thus, the present investigation indicated that the growth and development in non-active adolescents and in adolescent soccer-players give rise to a need for a higher protein intake than is usually recommended. However, the higher protein requirements did not seem to be related only to the increased energy expenditure imposed by the exercise training in the soccer-player group.

  19. Challenging the other: exploring the role of opponent gender in digital game competition for female players.

    Science.gov (United States)

    Vermeulen, Lotte; Núñez Castellar, Elena; Van Looy, Jan

    2014-05-01

    Abstract The present study investigated the effect of opponent gender on the game experience of female players. Concretely, it looked into skill perception and player emotions of women in same gender and cross-gender game competition. We set up a 2×2×2 (male vs. female opponent×low vs. high competitive women×lost vs. won game) experimental design in which women were instructed to play against a proclaimed male and female competitor. Unknowingly, however, participants played against an AI, which was configured to produce a winning and a losing condition for each opponent by manipulating difficulty. Results indicated that opponent gender only had an effect on perceived stress, which was higher with male opponents. Moreover, players evaluated their own gaming skills as lower and the skills of presumed male opponents as higher when they thought they were playing against men. Importantly, our results also showed that the above described pattern for self-perceived skills and perceived opponent skills was modulated by trait competitiveness with a larger effect size for low competitive women. Overall, this study illustrates that gender dynamics affect the play experience of women in cross-gender gaming competition. Implications and suggestions for future research are discussed.

  20. DIFFERENCES IN FUNCTIONAL AND MOTOR ABILITIES OFYOUNG FOOTBALL PLAYERS, BASKETBALL AND VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Franja Fratrić

    2009-11-01

    Full Text Available The main goal of this research is to determine whether and what differences exist between the three groups of subjects (high-quality football, volleyball and basketball cadets and youth age, in the motoric and functional abilities, as well as to identify dif- ferences between subgroups within each sport. The sample consists of 61 volleyball, 31 basketball player and football player 31 (total n = 123 male, cadet and youth age are members of local clubs. Subjects were born between 01.01.1991 and 12.12.1994. The sample of variables are the values of 17 tests for the evaluation of functional and mobile status. The Motor-functional status on the basis of the results of secondary value of foot- ball, basketball and volleyball make a clear conclusion that the football players showed the best results in almost all the tests and that they had the smallest disbalance in the power of certain groups of muscles.The football players hve the highest homogeneity.

  1. Ankle sprain injuries in soccer players aged 7-15 years during a one-year season

    Directory of Open Access Journals (Sweden)

    NIKOLAOS KOFOTOLIS

    2014-10-01

    Full Text Available Although ankle sprains are common in soccer, the role of various risk factors in soccer players aged 7-15 is unclear. The purpose of this study was to examine whether incidence of ankle sprain injuries, associated time loss of participation, and injury risk factors are associated with chronological age in soccer players aged 7-15 years. A sample of 677 male soccer players was divided in three age groups: between 7 and 9 years (U9, between 9 and 12 years (U12 and between 12 and 15 years (U15. Ankle sprain injury incidence, participation time loss, injury mechanisms, ankle region injured, and other risk factors were recorded in games and practice sessions using questionnaires for one year. During the study 38 ankle injuries were recorded, of which 27 were ankle sprains. These led to 182.7 sessions lost (on average, 6.71 lost sessions per injury. There was an increased risk of ankle injury in U15 group compared with U12 (relative risk = 2.34; 95% confidence interval, 1.28 to 5.02 while no injuries for the U9 were observed. Most incidents (66.7% were contact injuries with the highest injury risk displayed by goalkeepers. Injury rate was higher in games than in practice and increased in the second half of the match (p< .05. Multinomial logistic regression showed that history of previous injury was a significant predictor of ankle sprain in the U15 group (relative risk = 1.69; 95% confidence interval, 1.0 to 2.9. Age is an important factor for soccer training because many clubs use chronological age to separate their young players into teams. This study showed that children less than 9 years showed no injury risk while players older than 12 years showed a higher risk. Injury rate was, however, lower than that reported previously for adult players. Injury prevention strategies may be particularly useful for young adolescent soccer players

  2. Kinetic and Kinematic Analysis for Assessing the Differences in Countermovement Jump Performance in Rugby Players.

    Science.gov (United States)

    Floría, Pablo; Gómez-Landero, Luis A; Suárez-Arrones, Luis; Harrison, Andrew J

    2016-09-01

    Floría, P, Gómez-Landero, LA, Suárez-Arrones, L, and Harrison, AJ. Kinetic and kinematic analysis for assessing the differences in countermovement jump performance in rugby players. J Strength Cond Res 30(9): 2533-2539, 2016-The aim of this study was to ascertain the differences in kinetic and kinematic profiles between better and poorer performers of the vertical jump within a homogeneous group of trained adults. Fifty rugby players were divided into low scoring (LOW) and high scoring (HIGH) groups based on their performance in the vertical jump. The force, velocity, displacement, and rate of force development (RFD)-time curves were analyzed to determine the differences between groups. The analysis of the data showed differences in all the patterns of the ensemble mean curves of the HIGH and LOW groups. During the eccentric phase, the differences in the HIGH group with respect to the LOW group were lower crouch position, higher downward velocity, and higher force and RFD during the braking of the downward movement. During the concentric phase, the HIGH group achieved higher upward velocity, higher force at the end of phase, and a higher position at takeoff. The higher jump performances seem to be related to a more effective stretch-shortening cycle function that is characterized by a deeper and faster countermovement with higher eccentric forces being applied to decelerate the downward movement leading to enhanced force generation during the concentric phase.

  3. Upper extremity sensorimotor control among collegiate football players.

    Science.gov (United States)

    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 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.

  4. Quantitative evaluation of trunk muscle strength in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Sileno da Silva Santos

    2016-06-01

    Full Text Available Abstract Trunk muscle strength affects trunk controlling playing an important role in performance and to define the classes of wheelchair basketball players. Trunk control capacity differs among players and quantitative assessments of trunk muscle strength have not been investigated. The aim of this study was to identify and correlate quantitative measures of trunk muscle strength with the wheelchair basketball players' classification. Forty-two male wheelchair basketball players with spinal cord injury, amputation, post-poliomyelitis sequelae, and cerebral palsy had their trunk extension and flexion strength evaluated with isokinetic dynamometer. The classes 1.0, 2.0, 3.0, and 4.0 were considered for statistical analysis. Comparison of trunk muscle strength differed significantly between classes: 1.0 and 3.0; 1.0 and 4.0; 2.0 and 3.0; and 2.0 and 4.0. High correlation was found between the trunk muscle strength and players' classes. The findings of the present study showed a strong correlation of trunk muscle strength and wheelchair basketball classes being able to distinguish players in their classes. However, this quantitative method of evaluation of the trunk muscle strength cannot be solely used to make a decision on the full trunk control.

  5. Core executive functions are associated with success in young elite soccer players

    Science.gov (United States)

    Reinebo, Gustaf; Maurex, Liselotte; Ingvar, Martin; Petrovic, Predrag

    2017-01-01

    Physical capacity and coordination cannot alone predict success in team sports such as soccer. Instead, more focus has been directed towards the importance of cognitive abilities, and it has been suggested that executive functions (EF) are fundamentally important for success in soccer. However, executive functions are going through a steep development from adolescence to adulthood. Moreover, more complex EF involving manipulation of information (higher level EF) develop later than simple executive functions such as those linked to simple working memory capacity (Core EF). The link between EF and success in young soccer players is therefore not obvious. In the present study we investigated whether EF are associated with success in soccer in young elite soccer players. We performed tests measuring core EF (a demanding working memory task involving a variable n-back task; dWM) and higher level EF (Design Fluency test; DF). Color-Word Interference Test and Trail Making Test were performed on an exploratory level as they contain a linguistic element. The lower level EF test (dWM) was taken from CogStateSport computerized concussion testing and the higher level EF test (DF) was from Delis-Kaplan Executive Function System test battery (D-KEFS). In a group of young elite soccer players (n = 30; aged 12–19 years) we show that they perform better than the norm in both the dWM (+0.49 SD) and DF (+0.86 SD). Moreover, we could show that both dWM and DF correlate with the number of goals the players perform during the season. The effect was more prominent for dWM (r = 0.437) than for DF (r = 0.349), but strongest for a combined measurement (r = 0.550). The effect was still present when we controlled for intelligence, length and age in a partial correlation analysis. Thus, our study suggests that both core and higher level EF may predict success in soccer also in young players. PMID:28178738

  6. Performance outcomes after repair of complete achilles tendon ruptures in national basketball association players.

    Science.gov (United States)

    Amin, Nirav H; Old, Andrew B; Tabb, Loni P; Garg, Rohit; Toossi, Nader; Cerynik, Douglas L

    2013-08-01

    A complete rupture of the Achilles tendon is a devastating injury. Variables affecting return to competition and performance changes for National Basketball Association (NBA) players are not readily evident. Players in the NBA who ruptured their Achilles tendons and who underwent surgical repair would have more experience in the league, and the performance of those who were able to return to competition would be decreased when compared with their performance before injury and with their control-matched peers. Cohort study; Level of evidence, 3. Data for 18 basketball players with Achilles tendon repair over a 23-year period (1988-2011) were obtained from injury reports, press releases, and player profiles. Variables included age, body mass index (BMI), player position, and number of years playing in the league. Individual season statistics were obtained, and the NBA player efficiency rating (PER) was calculated for 2 seasons before and after injury. Controls were matched by playing position, number of seasons played, and performance statistics. Univariate and multivariate analyses were performed to assess the effect of each factor. At the time of injury, the average age was 29.7 years, average BMI was 25.6, and average playing experience was 7.6 years. Seven players never returned to play an NBA game, whereas 11 players returned to play 1 season, with 8 of those players returning for ≥2 seasons. Players who returned missed an average of 55.9 games. The PER was reduced by 4.57 (P = .003) in the first season and by 4.38 (P = .010) in the second season. When compared with controls, players demonstrated a significant decline in the PER the first season (P = .038) and second season (P = .081) after their return. The NBA players who returned to play after repair of complete Achilles tendon ruptures showed a significant decrease in playing time and performance. Thirty-nine percent of players never returned to play.

  7. Morphological and motor characteristics of Croatian first league female football players.

    Science.gov (United States)

    Jelaska, Petra Mandić; Katić, Ratko; Jelaska, Igor

    2013-05-01

    The aim of this study was to determine the structure of morphological and motor characteristics of Croatian first league female football players and their impact on the estimated quality of the players. According to the goal of the research, a sample consisted of 70 Croatian first league female football players. Participants were measured in 18 tests for assessing morphological characteristics, a set of 12 basic motor abilities tests and a set of 7 tests for assessing football-specific motor abilities. Exploratory factor analysis strategy was applied separately to all measured tests: morphological, basic motor abilities and football specific motor abilities. Factor analysis of morphological tests has shown existence of 3 significant latent dimensions that explain 64% of the total variability. Factors are defined as transverse dimensionality of the skeleton and voluminosity (35%), subcutaneous fat tissue (16%) and longitudinal dimensionality of the skeleton (13%). In the area of basic motor abilities, four factors were extracted. The first factor is responsible for the integration of agility and explosive power of legs, i.e. a factor of movement regulation (agility/lower body explosiveness) (23%), the second one defines muscle tone regulation (15%), the third one defines the frequency of leg movements (12%), while the fourth one is recognized as responsible for the manifestation of basic strength, particularly of basic core strength (19%). Two factors were isolated in the space of football-specific motor abilities: football-specific efficiency (53%) and situational football coordination (27%). Furthermore, by use of factor analysis on extracted latent dimensions (morphological, basic and football specific motor abilities) two higher order factors (explaining 87% of common variability) were extracted. They were named morphological-motor factor (54%) and football-specific motor abilities factor (33%). It is assumed that two extracted higher-order factors fully

  8. Nutrient intake and blood iron status of male collegiate soccer players.

    Science.gov (United States)

    Noda, Yuka; Iide, Kazuhide; Masuda, Reika; Kishida, Reina; Nagata, Atsumi; Hirakawa, Fumiko; Yoshimura, Yoshitaka; Imamura, Hiroyuki

    2009-01-01

    The purpose of this study was: 1) to collect baseline data on nutrient intake in order to advise athletes about nutrition practices that might enhance performance, and 2) to evaluate the dietary iron intake and blood iron status of Japanese collegiate soccer players. The subjects were 31 soccer players and 15 controls. Dietary information was obtained with a food frequency questionnaire. The mean carbohydrate (6.9 g.kg-1 BW) and protein (1.3 g/kg) intakes of the soccer players were marginal in comparisons with recommended targets. The mean intakes of calcium, magnesium, vitamin A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances (RDAs) or adequate dietary intakes in the soccer players. The mean intakes of green and other vegetables, milk and dairy products, fruits, and eggs were lower than the recommended targets. Thus, we recommended athletes to increase the intake of these foodstuffs along with slight increase in carbohydrate and lean meat. The mean intake of iron was higher than the respective RDA in the soccer players. A high prevalence of hemolysis (71%) in the soccer players was found. None of the soccer players and controls had anemia. Two soccer players had iron depletion, while none was found in the controls. In those players who had iron deficiency, the training load need to be lowered and/or iron intake may be increased.

  9. The development of a test of repeated-sprint ability for elite women's soccer players.

    Science.gov (United States)

    Gabbett, Tim J

    2010-05-01

    The purpose of this study was to develop a game-specific test of repeated-sprint ability for elite women's soccer players. Nineteen elite women's soccer players (mean +/- SD; age, 18.1 +/- 2.9 y) participated in this study. After familiarization, players completed a repeated-sprint test consisting of 6 x 20-m maximal effort sprints, on a 15-second cycle. At the completion of each sprint, players performed a 10-m deceleration and a 10-m active jog recovery. Ten elite female soccer players performed the test on 2 occasions, 1 week apart, to determine the reliability of the test. In addition, the validity of the repeated-sprint test to discriminate among players of different playing ability was evaluated by testing national (n = 11) and state (n = 8) women's soccer players. Heart rate and blood lactate concentration were recorded to determine the physiological responses to the test. The total sprint time proved to be highly reproducible (intraclass correlation coefficient = 0.91; typical error of measurement = 1.5%). However, the percentage decrement was less reliable (intraclass correlation coefficient = 0.14, typical error of measurement = 19.5%). The repeated-sprint test was valid in discriminating between national- and state-level players, with national players having significantly lower (p repeated-sprint times than state players (20.9 +/- 0.5 s vs. 23.3 +/- 0.4 s). The mean (+/-SD) heart rate and blood lactate concentration were 182 +/- 6 beats/min and 9.3 +/- 2.0 mmol/L, respectively. The results of this study demonstrate that the developed repeated-sprint test discriminates players of higher and lesser skill levels and offers a reliable method of assessing repeated-sprint ability in elite women's soccer players when results are expressed as the total sprint time.

  10. Statistical properties for direction alignment and chasing of players in football games

    CERN Document Server

    Narizuka, Takuma

    2016-01-01

    Focusing on motion of two interacting players in football games, two velocity vectors for the pair of one player and the nearest opponent player exhibit strong alignment. Especially, we find that there exists a characteristic interpersonal distance $ r\\simeq 500 $ cm below which the circular variance for their alignment decreases rapidly. By introducing the order parameter $ \\phi $ in order to measure degree of alignment of players' velocity vectors, we also find that the angle distribution between the above nearest players' velocity vectors changes from the wrapped Cauchy to the mixture of von Mises and wrapped Cauchy distributions at $ \\phi\\simeq 0.7 $. To understand these findings, we construct a simple model with the following two rules: chasing between two players and the reset of the chasing. We numerically show that our model successfully reproduce the results obtained from the actual data. Moreover, from the numerical study, we find that there is another characteristic distance $ r\\simeq 1000 $ cm bel...

  11. Surveillance of injuries among Kenya Rugby Union (KRU) players ...

    African Journals Online (AJOL)

    (38.2%) and concussion (8.9%) (table4). The types of ... being linked with dangerous play. A player in KC ... that bigger body sizes are associated with higher rates of injuries (9, 15). ... football Br J Sports Med 1974; 8: 183-187. 3. Nicholl J P ...

  12. Physical demands in elite team handball: comparisons between male and female players.

    Science.gov (United States)

    Bojsen Michalsik, L; Aagaard, P

    2015-09-01

    The aim of the present study was to examine potential differences in the physical demands imposed on male vs. female adult elite team handball players during match-play. Male and female elite team handball players were monitored over a six and five season time span, respectively. Each player was evaluated during match-play by use of video recording and subsequent computerized locomotive and technical match analysis. Furthermore, physiological measurements during match-play, physical testing and anthropometric measurements were performed. Female players (FP, N.=82) covered a longer mean total distance per match (4693±333 m, group means±SD) compared to male players (MP, N.=83, 3945±538 m) when playing full time (PVO2-max) than MP (70.9% of VO2-max, P<0.05), but performed less high-intense running per match (2.5% of total distance covered) than MP (7.9%, P<0.01). FP also spent less time standing still (10.8% of total effective playing time) compared to MP (36.9%, P<0.001) and showed fewer activity changes (663.8±99.7) compared to MP (1482.4±312.6, P<0.001). MP received more tackles in total in offence (34.5±21.3) and performed more tackles in total in defence (29.9±12.3) compared to FP (14.6±9.2, 20.7±9.7, P<0.05). Furthermore, MP performed more high-intense technical playing actions per match (36.9±13.1) than FP (28.3±11.0, P<0.05). The mean body height and body mass differed between MP (189.6±5.8 cm, 91.7±7.5 kg) and FP (175.4±6.1 cm, 69.5±6.5 kg, P<0.001). Substantial gender-specific differences in the physical demands in elite team handball were observed, with MP performing more high-intense, strength-related playing actions and high-intensity running than FP. Conversely, FP covered a greater total distance and demonstrated a higher relative workload than MP. The physical training of male and female elite team handball players should be designed to reflect these contrasting needs.

  13. AN EXAMINATION OF CHARISMATIC LEADERSHIP CHARACTERISTICS OF HANDBALL COACHES AS PERCEIVED BY THEIR PLAYERS

    Directory of Open Access Journals (Sweden)

    Veli Onur

    2015-01-01

    Full Text Available It is acknowledged that the leaders that are perceived as charismatic by their followers are quite successful in establishing cohesion in organizations and increasing the performance and satisfaction levels of the employees. Thus, it is believed that when coaches are perceived as charismatic by their players, it might play a significant role in achieving the goals set by the teams. The current study examines the charismatic leadership perception of male and female handball players playing in the leagues of Turkish Handball Federation according to different variables. The sampling of the study consists of 242 handball players in the leagues of Turkish Handball Federation during 2012-2013 season. In order to obtain data regarding the charismatic leadership perception of the players for their coaches, “Charismatic Leadership Scale” developed by Çelik (2011 was administered. This scale consists of eight subscales and 35 items. For the purposes of data analysis, reliability tests (Cronbach Alpha, t-test, one-way variance analysis and factor analysis were applied. KMO value for the scale was found to be 0.895 and Barlett’s Sphericity test χ2= 4898,521 at p < 0.001. According to the results of Cronbach Alpha test, the values for subscales were between 0.762 and 0.910. The comparison made according to the variables “sex” and “education level” showed statistically meaningful differences in some subscales (p <0.05. One-way ANOVA test results revealed meaningful differences among the groups in some subscales for the variables “age”, “league level”, “the duration of working with the same coach” and “the duration of doing the same sports branch (p<0.05. According to research findings, the players with lower levels of educational background think that their coach trusts them very much, cares them a lot, takes risks for success and has good communication with them. These findings are consistent with autocratic leadership findings

  14. Three-player conflicting interest games and nonlocality

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

  16. Strength Training Reduces Injury Rate in Elite Young Soccer Players During One Season.

    Science.gov (United States)

    Zouita, Sghair; Zouita, Amira B M; Kebsi, Wiem; Dupont, Grégory; Ben Abderrahman, Abderraouf; Ben Salah, Fatma Z; Zouhal, Hassane

    2016-05-01

    The purpose of this study was to examine the effect of strength training on physical fitness parameters and injuries occurrence in young elite soccer players. Fifty-two elite young soccer players (13-14 years) were divided on a randomized order into experimental group (EG, n = 26) and control group (CG, n = 26). For EG, 2 to 3 sessions of strength training (90 minutes) were introduced weekly in their training program for 12 weeks (4 × 3 weeks separated by 1-week recovery). Sprint tests (10-20-30 m), T-test time, and jumping tests were measured at the start (T0), at the middle (T1), and at the end of the experiment period (T2). The injury rate was recorded by the medical and fitness training staff throughout the soccer season. Compared to CG, EG performed significantly better in sprint running and T-test time at T2 (p soccer season. The rate was higher in CG (13 injuries) than in training group (4 injuries). This study showed that strength training accurately and efficiently scheduled in youth soccer players, induced performance improvement, and reduced the rate of injuries.

  17. Race differences in ventricular remodeling and function among college football players.

    Science.gov (United States)

    Haddad, Francois; Peter, Shanon; Hulme, Olivia; Liang, David; Schnittger, Ingela; Puryear, Josephine; Gomari, Fatemeh A; Finocchiaro, Gherardo; Myers, Jonathan; Froelicher, Victor; Garza, Daniel; Ashley, Euan A

    2013-07-01

    Athletic training is associated with increases in ventricular mass and volume. Recent studies have shown that left ventricular mass increases proportionally in white athletes with a mass/volume ratio approaching unity. The objective of this study was to compare the proportionality in ventricular remodeling and ventricular function in black versus white National Collegiate Athletic Association Division I football players. From 2008 to 2011, football players at Stanford University underwent cardiovascular screening with a 12-point history and physical examination, electrocardiography, and focused echocardiography. Compared with white players, black players had on average higher left ventricular mass indexes (77 ± 11 vs 71 ± 11 g/m(2), p = 0.009), higher mass/volume ratios (1.18 ± 0.16 vs 1.06 ± 0.09 g/ml, p 1.2. Mass/volume ratio was inversely related to early diastolic tissue Doppler velocity e' (r = -0.50, p velocity of circumferential shortening, and isovolumic acceleration. In conclusion, black college football players exhibit more concentric ventricular remodeling, lower early diastolic annular velocities, and increased ventricular voltage compared with white players. Ventricular mass increases proportionally to volume in white players but not in black players. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. THE COMPARISON OF SOME PHYSICAL AND PHYSIOLOGICAL FEATURES OF ELITE YOUTH NATIONAL AND AMATEUR BADMINTON PLAYERS

    Directory of Open Access Journals (Sweden)

    Aziz GÜÇLÜÖVER

    2012-12-01

    Full Text Available The aim of this study was to compare some physical and physiological features of elite and amateur badminton players. The sample of the study were totally 31 Turkish badminton players in 2010-2011 season; consisting of Youth National male players (n=16, age: 16.8±1.5 and amateur level male players (n=15, age: 16.3±0.8 from Sport High School. After the body composition of players were determined, agility test, sit and reach test, multiple reaction test, hand grip strength test and wingate anaerobic power test were applied to them. “Independent T-test” was applied for comparisons among independent groups. After statistical analyses, it was determined that elite players had higher values in height (cm, agility (second, right hand grip strength (kg (p≤0.01, body fat percentage and fat free mass (kg (p≤0.05 than amateur players. As a result, it was seen that the elite and amateur level badminton affected the height, agility, hand grip strength and body composition (lower body fat percentage and higher fat free mass of players positively.

  19. Nerve conduction studies in lower limb of elite Nepalese football players: an insight into neural adaptations.

    Science.gov (United States)

    Sharma, Deepak; Paudel, Bishnu H; Khadka, Rita; Thakur, Dilip; Shah, Dev K; Sapkota, Niraj K; Yadav, Ram L; Yadav, Prakash K

    2017-03-01

    The study was aimed to assess somatic neural alterations in lower limbs of elite Nepalese football players by comparing their nerve conduction parameters with non-athletic controls. Players (N.=27, age 22.74±2.52 yrs.) with excellent cardio-respiratory fitness and presenting no signs of injuries, and sedentary controls (N.=29, age 23.41±2.95 yrs.) were recruited for the study. Standard nerve conduction techniques were applied to evaluate posterior tibial and sural nerves in the dominant and non-dominant limbs of each individual. Conduction velocity, onset latency, amplitude and duration of the motor and sensory evoked responses were recorded. The players had significantly lower resting mean heart rate, systolic and diastolic blood pressure than controls. Tibial compound muscle action potential (CMAP) showed higher amplitude as compared to controls; tibial proximal CMAP amplitude [(13.624±4.57) vs. (10.810±4.62) mV, P=0.035] of dominant leg, tibial proximal [(13.893±4.60) vs. (11.083±4.51) mV, P=0.045] and distal [(16.388±3.62) vs. (13.958±4.65) mV, P=0.049] amplitude of non-dominant leg. Likewise, players had significantly shorter tibial CMAPs duration of each lower limb compared with corresponding limb of controls. Sural nerve of non-dominant leg revealed shortened sensory nerve action potential duration [(1.729±0.25) vs. (1.904±0.289) ms, P=0.018]. Increased tibial CMAP amplitude and decreased CMAP duration in players suggest excitation of more number of motor units and higher synchronicity of muscle fibers' discharge than in controls respectively. Higher amplitude can also be attributed to increase in muscle fiber size and/or efficiency of neuromuscular transmission. Increased synchronicity indirectly reflects narrow range of conduction velocity among tibial neurons. The adaptive changes in somatic nerves need more crucial research for exact identification of sites and the structures responsible.

  20. ANTHROPOMETRIC AND PHYSIOLOGICAL CHARACTERISTICS ON INDIAN INTERUNIVERSITY BASKETBALL PLAYERS

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    Shyamal Koley

    2010-08-01

    Full Text Available The purpose of this study was two-fold, firstly, to evaluate the anthropometric profile of Indian interuniversity basketball players and, secondly, to search the correlation of body mass index, % body fat, hand grip strength (right dominant and Vo2max,with other anthropometric characteristics studied. Eleven anthropometriccharacteristics, four body composition parameters, two physical and two physiological variables were measured on randomly selected 60 inter-university Indian basketball players (35 males and 25 females aged 18–25 years from Guru Nanak Dev University, Amritsar, Punjab, India with adequate controls (n = 102, 52 males and 50 females. The results indicated that male basketball players were taller (6.63% and heavier (7.31% and female basketball players were slightly taller (0.31% and lighter (3.74% than their control counterparts. One way analysis of variance showed significant (p ≤ .004 - .000 between group differences in all the variables (excepthip circumference between basketball players and controls. In basketball players, significantly positive correlations were found with BMI and other 12 variables, with percent body fat and 7 variables, with right hand grip strength and 12 variables and with Vo2max and other 9 variables, and significantly negative correlationswere found with BMI and other 1 variable (% lean body mass, with percent body fat and other 6 variables, with right hand grip strength and other 2 variables and with Vo2max with other 3 variables. The findings of the present study might be useful in future investigation on player selection, talent identification in the game of basketball and its training program development.

  1. Computing Sequential Equilibria for Two-Player Games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Koller and Pfeffer pointed out that the strategies...... a sequential equilibrium are computed. In particular, we show that a sequential equilibrium for a two-player zero-sum game with imperfect information but perfect recall can be found in polynomial time. In addition, the equilibrium we find is normal-form perfect. Our technique generalizes to general-sum games...

  2. Reference Values and Gender Differences of the Functional Parameters in Romanian Elite Junior Tennis Players

    Directory of Open Access Journals (Sweden)

    Adrian NAGEL

    2013-06-01

    Full Text Available Purpose: To establish the reference values and gender differences regarding fitness, strength, and time reaction of the Romanian elite junior tennis players. Material and Methods: Thirty four junior tennis players (19 male, 15 female with a mean age of 15 years were selected from the database of the Cardiopulmonary Effort Testing and Physical Performance Laboratory from Faculty of Physical Education and Sport, West University of Timisoara. To be included in the study, a tennis player had to belong to the Romanian Tennis Federation as a junior, be among the 50 best players in his/her category, and have no pathology at the evaluation moment. All subjects underwent functional evaluation by performing a maximal cardiopulmonary exercise test, the counter movement jump test and complex opto-acoustic reaction test. Results: The functional performance are significantly different for males and females in all parameters studied, with male tennis players showing better performance than female tennis players. Conclusions: The mean values of functional parameters of the Romanian elite junior tennis players are lower than international competitive tennis athletes. There are significant gender differences in junior tennis players. We hope that the present study results provide useful reference values for coaches and physical trainers in order to improve functional performance of their junior tennis players.

  3. Efficiently detecting outlying behavior in video-game players

    Directory of Open Access Journals (Sweden)

    Young Bin Kim

    2015-12-01

    Full Text Available 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.

  4. MEANING TO BE VOLLEYBALL PLAYER IN CAREER TRANSITION PHASE

    Directory of Open Access Journals (Sweden)

    Adriana Justino

    2016-09-01

    Full Text Available The objective of this study is to assess the meaning of being that a volleyball player for the under-19 players who are experiencing a transition in their in career. Sixteen male players aged 17 and 18 were evaluated, by being asked the triggering question “What does being a volleyball player mean to you?” The analysis of the discourses was carried out according to the procedures recommended by Miles & Huberman (2004. Four response categories resulted: psychoemotional and behavioral skills, emotions in sport, recognition and financial return, skills as an athlete/player. The athletes showed that the meaning of sport lies especially in the passion for practice, but also, in the improving of their tactics and techniques, in the development of psychoemotional and behavioral skills, in the professional recognition and, to a lesser degree, in the financial aspect. Most athletes state they intend to continue in the juvenile sports categories, therefore, understanding the meaning of this activity in their life can be the key to the elaboration of a plan of psychological preparation whose aim is to provide support to their needs in this moment of professional choice.

  5. Ιnjuries in greek amateur soccer players

    Directory of Open Access Journals (Sweden)

    GEORGIOS TSIGANOS

    2007-01-01

    Full Text Available The purpose of this study was to record retrospectivelythe epidemiology of injuries in amateur Greek soccer players. Three hundred and one (301 amateur soccer playersvoluntarily participated in the study. Participants answered aspecially-designed questionnaire that included questionsabout demographics, playing surface, division, position,hours of training plus participation, the use of stretching orprophylactic tape, the injury mechanism, the location andtype of injury. During the five years these soccer playerssustained a total of 1.745 injuries, that diagnosed by the orthopedist of the team. Most of injuries were strains (33%,overuse (27% and sprains (25%. The location of injurieswas the thigh (38 %, ankle (27% and knee (13%. Therewas a significant difference in the total number of injuriesamong soccer players with or without scoliosis (t=3.152,p. 0.05 and players that played on sand/dirt (gravel, whosustained more injuries than the players who played on artificial grass or on grass (t=3.413, p. 0.05. No differenceswere found in the other measurement parameters. The results of our study shows that spine deformities and groundsurfaces are the factors that causes more injuries in amateurGreek soccer players.

  6. A Discrete Evolutionary Model for Chess Players' Ratings

    CERN Document Server

    Fenner, Trevor; Loizou, George

    2011-01-01

    The Elo system for rating chess players, also used in other games and sports, was adopted by the World Chess Federation over four decades ago. Although not without controversy, it is accepted as generally reliable and provides a method for assessing players' strengths and ranking them in official tournaments. It is generally accepted that the distribution of players' rating data is approximately normal but, to date, no stochastic model of how the distribution might have arisen has been proposed. We propose such an evolutionary stochastic model, which models the arrival of players into the rating pool, the games they play against each other, and how the results of these games affect their ratings. Using a continuous approximation to the discrete model, we derive the distribution for players' ratings at time $t$ as a normal distribution, where the variance increases in time as a logarithmic function of $t$. We validate the model using published rating data from 2007 to 2010, showing that the parameters obtained...

  7. Estimating Maximal Heart Rate with the ‘220-Age’ Formula in Adolescent Female Volleyball Players: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Nikolaidis Pantelis Theodoros

    2014-09-01

    Full Text Available Purpose. Although maximal heart rate (HRmax is used widely to assess exercise intensity in training, there are limited data with regards to the validity of age-based prediction equations of HRmax in volleyball players. Therefore, the aim of the present study was to compare the measured-HRmax of two prediction equations (Fox-HRmax = 220 − age and Tanaka-HRmax = 208 − 0.7 × age in young female volleyball players. Methods. The study involved 47 volleyball players (age 13.39 ± 2.01 years, body mass 54.0 ± 10.8 kg, height 162.7 ± 10.2 cm who performed a graded exercise field test (20 m shuttle run endurance test to assess HRmax. Measured-HRmax values were compared with the Fox and Tanaka prediction equations. Results. The results showed that mean scores for HRmax significantly differed between measured and predicted values (p < 0.001, ŋ2 = 0.49. Post-hoc tests revealed that Fox-HRmax overestimated measured-HRmax (mean difference 5.7 bpm; 95% CI [3.0, 8.5], whereas Tanaka-HRmax was similar to measured-HRmax (-2.2 bpm; 95% CI [-4.9, 0.4]. HRmax did not correlate with age (r = 0.16, p = 0.291. Conclusions. The results of this study failed to validate the widely used ‘220−age’ formula in volleyball players. Coaches and fitness trainers should take into account that the overestimation of HRmax by the Fox equation might lead to prescribing exercise at a higher intensity than what is targeted. Therefore, the Tanaka equation appears to offer a more accurate prediction equation of HRmax than the Fox equation in young female volleyball players.

  8. In-season training periodization of professional soccer players

    Directory of Open Access Journals (Sweden)

    A Los Arcos

    2017-04-01

    Full Text Available 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. Twentyfour 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.

  9. Cervical range of motion and proprioception in rugby players versus non-rugby players.

    Science.gov (United States)

    Lark, Sally D; McCarthy, Peter W

    2007-06-01

    In this study, we examined the effects of number of years of playing rugby on neck function. Active cervical spine range of motion and proprioception were assessed in 14 non-rugby-playing but trained sportsmen (mean age 28 years, s = 7) and 46 rugby players (26 rugby forwards: mean age 26 years, s = 5; mean years played 14 years; 20 backs: mean age 24 years, s = 5; mean years played 14 years). Active cervical range of motion in flexion, extension, left and right lateral flexion, plus left and right rotation were measured using a cervical range of motion device. The ability to reposition the head in a central position with eyes closed was taken as a measure of proprioception. Results show that rugby forwards generally had the least active cervical range of motion, particularly neck extension (forwards, 43 degrees ; backs, 55 degrees ; controls, 58 degrees ), with the decrement correlating with the number of years played. In addition, repositioning was significantly worse in rugby players after neck extension than non-rugby players (6 degrees vs. 3 degrees ). The active cervical range of motion of rugby forwards is similar to that of whiplash patients, suggesting that participation in rugby can have an effect on neck range of motion that is equivalent to chronic disability. Reduced active cervical range of motion could also increase the likelihood of injury and exacerbate age-related neck problems.

  10. Using anthropometric and performance characteristics to predict selection in junior UK Rugby League players.

    Science.gov (United States)

    Till, Kevin; Cobley, Steve; O'Hara, John; Brightmore, Amy; Cooke, Carlton; Chapman, Chris

    2011-05-01

    Research examining the factors influencing selection within talented junior Rugby League players is limited. The aims of this study were firstly to determine whether differences existed for anthropometric and performance characteristics between regional and national selection in high performance UK junior Rugby League players, and secondly to identify variables that discriminated between these selection levels. Regional representative (n=1172) selected junior players (aged 13-16 years) undertook an anthropometric and fitness testing battery with players split according to selection level (i.e., national, regional). MANCOVA analyses, with age and maturation controlled, identified national players as having lower sum of 4 skinfolds scores compared to regional players, and also performed significantly better on all physical tests. Stepwise discriminant analysis identified that estimated maximum oxygen uptake (VO2max), chronological age, body mass, 20 m sprint, height, sum of 4 skinfolds and sitting height discriminated between selection levels, accounting for 28.7% of the variance. This discriminant analysis corresponded to an overall predictive accuracy of 63.3% for all players. These results indicate that performance characteristics differed between selection levels in junior Rugby League players. However, the small magnitude of difference between selection levels suggests that physical qualities only partially explain higher representative selection. The monitoring and evaluation of such variables, alongside game related performance characteristics, provides greater knowledge and understanding about the processes and consequences of selection, training and performance in youth sport. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Somatotype of competitive youth soccer players from Brazil.

    Science.gov (United States)

    Fidelix, Yara Lucy; Berria, Juliane; Ferrari, Elisa Pinheiro; Ortiz, Jaelson Gonçalves; Cetolin, Tiago; Petroski, Edio Luiz

    2014-09-29

    The aim of this study was to identify the morphological configuration of youth athletes from professional soccer clubs and to verify their differences according to the tactical position on the field. Overall, 67 male players aged 15 to 17 years were evaluated. The examined anthropometric measurements included body mass, body height, skinfolds (triceps, subscapular, supraspinal and medial calf), girths (flexed and tensed arm and calf) and breadths (humerus and femur). For statistical purposes, analysis of variance and post hoc Bonferroni and Kruskal-Wallis tests were used. We concluded that goalkeepers were heavier and taller than center backs (p = 0.015 and p = 0.001), midfielders (p = 0.005 and p somatotype for defense, forward and goalkeeper positions was a balanced mesomorph. Midfield players showed ectomorphic-mesomorph characteristics. It was concluded that goalkeepers were characterized as being taller and heavier and that somatotype features of athletes were similar between positions, except for midfield players.

  12. Two-player envy-free multi-cake division

    CERN Document Server

    Cloutier, John; Su, Francis Edward

    2009-01-01

    We introduce a generalized cake-cutting problem in which we seek to divide multiple cakes so that two players may get their most-preferred piece selections: a choice of one piece from each cake, allowing for the possibility of linked preferences over the cakes. For two players, we show that disjoint envy-free piece selections may not exist for two cakes cut into two pieces each, and they may not exist for three cakes cut into three pieces each. However, there do exist such divisions for two cakes cut into three pieces each, and for three cakes cut into four pieces each. The resulting allocations of pieces to players are Pareto-optimal with respect to the division. We use a generalization of Sperner's lemma on the polytope of divisions to locate solutions to our generalized cake-cutting problem.

  13. Somatic parameters of 17 year old soccer players in the older youth category in relation to sports performance

    Directory of Open Access Journals (Sweden)

    Petr Kutáč

    2013-09-01

    Full Text Available BACKGROUND: Somatic parameters are included not only in the general structure of sporting performance, but also in the structure of sporting performance in soccer. In light of this structure, higher performance players should have better somatic performance prerequisites, and their somatic parameters should differ from players with lower performance levels. OBJECTIVE: The aim of the study is to assess the somatic parameters of players with different performance levels. METHODS: The research included 90 soccer players in the age of 17 years in three performance categories playing in the junior competition in the Czech Republic. Average age of the individual levels – highest performance 17.61 ± 0.48, middle performance 17.50 ± 0.50, lowest performance 17.50 ± 0.50 years. The following was monitored – basic anthropometric parameters (body weight, body height, somatotype (Heath-Carter, representation of body fat (BF, fat free mass (FFM and the total body water (TBW. The Tanita 418 MA tetrapolar bioelectrical impedance (BIA scale was used for the determination of the representation of BF and the TBW. All players were measured at the beginning of the competition period in the same year. All measurements were implemented in the morning hours by the same person with corresponding experience. RESULTS: The average values of somatic parameters measured in the individual performance categories show that we can only consider them to be an indicator of sporting performance up to a particular performance level. The boundary was the middle performance level (teams playing regional competition as their mean values of the monitored somatic parameters significantly differed from the mean values of players at the lowest performance level (teams playing at the district and municipal levels but they did not differ when compared with the mean values of the players at the highest performance level (teams playing the top junior league. CONCLUSIONS

  14. 高校高水平足球运动员个性特征研究%Research on the Characteristic Features of High-level Soccer Players in Colleges and Universities

    Institute of Scientific and Technical Information of China (English)

    田振华

    2012-01-01

    With the Cartel 16PF measuring table,the author of this paper takes 60 high-level soccer players in colleges and universities as the testing group,and takes college students majoring in soccer in PE departments in colleges and universities as the control group.The study shows that male high-level soccer players are better than average male soccer majors in colleges and universities in Section C and F,while female high-level soccer players are better than average female soccer players in colleges and universities in Section G;but both female and male high-level players show lower competence than average soccer players in Section I.Compared with male players,female players show features of lower competence in Sections C,E,F,N and Q1,and features of higher competence in Section M.Compared with soccer majors,high-level soccer players show features of higher competence in Sections C,G and Q2,and show features of lower competence in Section O.%采用卡特尔16PF测量量表,以全国高校高水平足球运动员60名作为实验组,高校体育学院足球专选学生作为对照组。研究结果表明,高校高水平男足运动员在C项、F项,女足运动员在G项高于全国大学生常模;在I项上则均低于全国大学生常模。女足与男足运动员相比在C、E、F、N、Q1项上呈低分特征,在M项上呈高分特征;高水平足球运动员与足球专选学生相比,在C、G、Q2项上呈高分特征,在O项上呈低分特征。

  15. Concussion Frequency Associates with Musculoskeletal Injury in Retired NFL Players.

    Science.gov (United States)

    Pietrosimone, Brian; Golightly, Yvonne M; Mihalik, Jason P; Guskiewicz, Kevin M

    2015-11-01

    Concussion is commonly associated with immediate and persistent alterations in motor function affecting postural control and gait. Patients with lower extremity joint injury have demonstrated functional alterations in the cerebral cortex, suggesting that musculoskeletal injury may be linked to alterations in brain function. Therefore, we examined the associations between concussion frequency and lower extremity musculoskeletal injury sustained during professional careers of National Football League (NFL) players in a cross-sectional study. An inclusive health history survey was mailed to 3647 NFL players who retired during 1930-2001. Respondents reported total concussion frequency (zero, one, two, or three or more) and presence (yes/no) of specific knee and ankle musculoskeletal injury during their NFL career. Separate logistic regression models were used to estimate associations between concussion frequency and each musculoskeletal injury type, adjusting for number of years played in the NFL, body mass index while playing in the NFL, and playing position. Data from 2429 players (66.6% response rate) were available for analysis. Nearly 61% reported experiencing a concussion while competing in the NFL. Meniscal tear was the most commonly reported musculoskeletal injury (32%). Compared with NFL players who did not sustain a concussion, retired NFL players with one, two, or three or more concussions had between 18% and 63%, 15% and 126%, and 73% and 165% higher odds of reporting various musculoskeletal injuries, respectively. A history of concussions was associated with a history of musculoskeletal injuries during NFL careers. These data suggest that a higher number of concussions is linked with higher odds of reporting a musculoskeletal injury.

  16. Psychological games of entangled players

    CERN Document Server

    Zak, Michail

    2012-01-01

    The paper introduces a new approach to theory of differential games in which entangled players try to predict and influence actions of their adversaries. The entanglement is generated be a joint probability density known by the players. Incase of complex density, its imaginary part represents a measure of uncertainty of the density distribution. The novelty of the approach is in non-Newtonian mathematical formalism thatis based upon a behavioral model of Livings. The model is quantum-inspired: it represented by a modified Madelung equation which the quantum potential is replaced by different, specially chosen "computational" potential. It consists of motor dynamics simulating actual behavior of the object, and mental dynamics representing evolution of the corresponding knowledge-based and incorporating this knowledge in the for m of information flows into the motor dynamics. Due to feedback from mental dynamics, motor dynamics attains quantum-like properties: its trajectory splits into a family of different t...

  17. Motivational profile quality players handball

    Directory of Open Access Journals (Sweden)

    Alfonso Martínez Moreno

    2017-06-01

    Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

  18. The effect of two types of stretching on flexibility in selected joints in youth soccer players

    Directory of Open Access Journals (Sweden)

    Andrea Mahrová

    2014-03-01

    Full Text Available Background: The nature of soccer causes overloading of certain muscles and muscle groups that are most often involved in typical training activities of players. Often the absence of additional leisure-time activities typical for children and adolescents leads to an increased risk of muscle imbalance. Objective: We were interested in the occurrence of muscle imbalance, specifically an occurrence of muscle shortening and limited flexibility of the spine as well as decreased range of motion (ROM in selected joints among young soccer players. Methods: The players were randomly selected to take part in the study. Twelve young soccer players took part in the first group and thirteen in the second group (age 13 years, body weight 40.5 ± 3.9 vs. 41.5 ± 7.8 kg, height 150.0 ± 5.0 vs. 153.0 ± 9.8 cm. The first team performed only static stretching exercises at the end of the training session and the other team performed, except for static stretching, also dynamic stretching exercises always at the beginning of the training session. The effect of the stretching program on range of motion in chosen joints was assessed by 2 × 2 repeated-measures ANOVA (stretching methods × time. The statistical significance of a-level was set to .05 and partial ηp2. Results: Pre-test measurements revealed an occurrence of muscle shortening and limited ROM of the spine and selected joints mostly in the pelvis and lower limbs in all study participants. Comparison of ROM in selected joints between pre-test and post-test in program including both static and dynamic stretching showed significant increase of left hip during flexion (p = .03, ηp2 = .20. The program with only static stretching showed significant decrease the ROM of ankle plantar flexion (p = .04, ηp2 = .18. We did not find any significant difference between stretching programs on ROM. As for muscle shortening, both side improvements (higher number of subjects with no

  19. Speed and agility of 12- and 14-year-old elite male basketball players.

    Science.gov (United States)

    Jakovljevic, Sasa T; Karalejic, Milivoje S; Pajic, Zoran B; Macura, Marija M; Erculj, Frane F

    2012-09-01

    The aims of this study were (a) to identify and compare the speed and agility of 12- and 14-year-old elite male basketball players and (b) to investigate relations between speed and agility for both age groups of basketball players, to help coaches to improve their work. Sixty-four players aged 12 (M = 11.98 years, SD = 0.311) and 54 players aged 14 (M = 14.092 years, SD = 0.275) were tested. Three agility tests: agility t-test, zigzag agility drill, and agility run 4 × 15 m and 3 speed tests: 20-m run, 30-m run, and 50-m run were applied. Fourteen-year-old players achieved significantly better results in all speed and agility tests compared with 12-year-old players. The correlation coefficient (r = 0.81, p = 0.001) showed that 12-year-old players have the same ability in the 30- and 50-m runs. The other correlation coefficient (r = 0.59, p = 0.001) indicated that 20- and 30-m runs had inherently different qualities. The correlation coefficients between agility tests were year-old players, the correlation coefficients between the speed test results were 0.71, which means that all the 3 tests represent the same quality. During the speed training of 12-year-old players, it is advisable to focus on shorter running distances, up to 30 m. During the agility training of the same players, it is useful to apply exercises with various complexities. In speed training of the 14-year-old players, the 30- and 50-m runs should be applied, and agility training should include more specific basketball movements and activities.

  20. 高职生犹豫人格特质的现状及FIS量表的适用性%A Study on Higher Vocational School Students'Indecisiveness Personality and Applicability Research of the Frost and Shows'Indecisiveness Scale

    Institute of Scientific and Technical Information of China (English)

    杨雪艳; 吴真

    2016-01-01

    Based on the data collected from 775 students in higher vocational colleges,this paper is to examine the reliability and validity of the Frost and Shows'indecisiveness scale form higher vocational college students.The criteria were the self esteem scale,Chinese version of Frost's multidimensional perfectionism scale (FMPS).Results:The item analysis indicated good homogeneity and discrimination of the items;The exploratory factor analysis indicated that the scale included confidence,planning and anxiety three factors,and the cumulated variance that can be explained by the three factors were 49. 7 1 6%;the confirmatory factor analysis indicated that the three factor model fit well with conceptual model,and the structural validity of the scale was acceptable;The correlation analyses indicated that the revised scale had good criterion related validity,and the absolute value of the correlation coefficients ranged from 0.34 to 0.72(P <0.05);The Cronbach's alpha coefficients for the factors ranged from 0.68 to 0.76.Retest reliability of whole scale was 0.73 and retest reliability of whole scale were significant (P<0.01).Conclusion:The Frost and Shows'indecisiveness scale form Chinese version is a reliable and valid instrument,and it meets the psychometric requirement.The higher vocational college students'in-decisiveness personality is at the middle level,and there are no significant differences in gender,grade, subj ect and hometown.%引进Frost 和 Shows等人编制的犹豫量表(FIS量表),在高职学生样本中进行中文版信效度检验,并探究高职生犹豫人格现状.选取自尊量表和中文版Frost多维度完美主义问卷(MPSF)作为效度指标,采取整群取样的方法对775名高职生进行集体施测.结果发现:项目分析结果显示量表条目有较好同质性和区分度;探索性因素分析表明,FIS量表包括自信、计划、焦虑3个因子,这3个因子可解释总变异的49.716%;验证性因素分析表明,提取的3

  1. Computing sequential equilibria for two-player games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Their algorithm has been used by AI researchers for cons...

  2. Computing sequential equilibria for two-player games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Their algorithm has been used by AI researchers for cons...

  3. Changes of standard physiological-perceptual markers and circulating MicroRNAs in response to tennis match-play: A case report of two elite players

    Directory of Open Access Journals (Sweden)

    Hoppe Matthias Wilhelm

    2016-06-01

    Full Text Available This study aimed to describe the acute changes of both standard physiological-perceptual markers and circulating microRNAs in response to tennis match-play in a detailed case report. Two elite male baseliners with comparable tennis experience were tested for anthropometric and fitness related variables and played 2 h of match-play on a red-clay court. The changes of standard physiological-perceptual markers including the heart rate, lactate concertation, creatine kinase activity, urea concentration and rating of perceived exertion as well as circulating microRNA-133a, -486 and -126 expression rates were examined at 10 different time-points (i.e., pre, during and up to 24 h post match-play. Player 2 had lower fitness related variables, but a higher heart rate, lactate concentration, creatine kinase activity and rating of perceived exertion during play than player 1. Player 2 showed an increase in all microRNAs (≤3.83-fold, most evident post match-play, whereas player 1 demonstrated a decrease (≤0.41-fold. The time-course in the changes of all standard physiological-perceptual markers was similar in both players, whereas this of the microRNAs was different. It was concluded that the relative changes of the circulating microRNA-133a, -486 and 126 expression rates of both players differed in response to tennis match-play with respect to the experienced physiological-perceptual stress and the underlying fitness level. Therefore, circulating microRNAs can serve as additional biomarkers for tennis exercise physiology and may be assessed together with standard markers to conclude whether key cellular regulatory processes were induced in response to match-play.

  4. Sport commitment in adolescent soccer players

    Directory of Open Access Journals (Sweden)

    Noelia Belando Pedreño

    2016-03-01

    Full Text Available The aim of this study was to contribute to the postulates of the self-determination theory, the hierarchical model of intrinsic and extrinsic motivation by Vallerand, and social goals. A structural regression model was estimated to analyze the relations between social goals (responsibility and relationships, praise for autonomous behavior, satisfaction of the basic psychological needs and intrinsic motivation in commitment to sport. A sample of 264 young Spanish soccer players aged between 14 and 16 (M =14.74, SD =.77 participated in the study. Structural Equation Modeling results showed that the social responsibility goal, the social relationship goal and praise for autonomous behavior predicted perceived competence. Furthermore, the relationship goal also predicted the need for relatedness. Satisfaction of the basic psychological needs for competence and relatedness predicted intrinsic motivation. Intrinsic motivation positively predicted future commitment to sport. These results highlighted the importance of social goals, praise for autonomous behavior and psychological mediators in encouraging greater commitment in young soccer players. Future research should focus on the coach’s role in generating greater commitment to sport through the development of intervention methodologies based on social goals.

  5. Comparison of two aerobic field tests in young tennis players.

    Science.gov (United States)

    Fargeas-Gluck, Marie-Agnès; Léger, Luc A

    2012-11-01

    This study compares the maximal responses of a new aerobic tennis field test, the NAVTEN to a known aerobic field test, often used with young tennis players, that is, the continuous multistage 20-m shuttle run test (20-m SRT). The NAVTEN is an intermittent (1-minute/1-minute) multistage test with side-to-side displacements and ball hitting. Ten young elite tennis players aged 12.9 ± 0.3 (mean ± SD) randomly performed both tests and were continuously monitored for heart rate (HR) and oxygen uptake (V[Combining Dot Above]O2) using the Vmax ST (Sensormedics). The 20-m SRT and NAVTEN show similar HRpeak (202 ± 6.1 vs. 208 ± 9.5, respectively) and V[Combining Dot Above]O2peak (54.2 ± 5.9 vs. 54.9 ± 6.0 ml·kg·min). Pearson correlations between both tests were 0.88 and 0.92 for V[Combining Dot Above]O2peak and maximal speed, respectively. The NAVTEN yielded V[Combining Dot Above]O2peak values that are typical for active subjects of that age and are similar to the 20-m SRT supporting its use to measure aerobic fitness of young tennis players in specific and entertaining field conditions. The fact that two-thirds of the tennis players achieved a different ranking (±1 rank) with the NAVTEN and the 20-m SRT suggests that the NAVTEN may be more specific than the 20-m SRT to assess aerobic fitness of tennis players. From a practical point of view, the NAVTEN test is more specific and pedagogical for young tennis players even though both tests yield similar maximal values.

  6. Vitamin D Deficiency Among Professional Basketball Players.

    Science.gov (United States)

    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 (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, respectively). There is a high prevalence of vitamin D deficiency

  7. Historical Patterns and Variation in Treatment of Injuries in NFL (National Football League) Players and NCAA (National Collegiate Athletic Association) Division I Football Players.

    Science.gov (United States)

    McCarty, Eric C; Kraeutler, Matthew J; Langner, Paula; Cook, Shane; Ellis, Byron; Godfrey, Jenna M

    We conducted a study to identify and contrast patterns in the treatment of common injuries that occur in National Football League (NFL) players and National Collegiate Athletic Association (NCAA) Division I football players. Orthopedic team physicians for all 32 NFL and 119 NCAA Division I football teams were asked to complete a survey regarding demographics and preferred treatment of a variety of injuries encountered in football players. Responses were received from 31 (97%) of the 32 NFL and 111 (93%) of the 119 NCAA team physicians. Although patellar tendon autograft was the preferred graft choice for both groups of team physicians, the percentage of NCAA physicians who allowed return to football 6 months or less after anterior cruciate ligament reconstruction was significantly (P = .03) higher than that of NFL physicians. Prophylactic knee bracing, which may prevent medial collateral ligament injuries, was used at a significantly (P football players.

  8. Junior football players' classification of runners as their teammates from 400-msec. video clips.

    Science.gov (United States)

    Steel, Kylie A; Adams, Roger D; Canning, Colleen G

    2008-08-01

    It was hypothesized that a specialized gait recognition skill enables humans to distinguish the gait of familiar from unfamiliar individuals, and that this may have relevance in team sports. Runners seen for less than half a second can be classified as teammates or not by adult players, so it may be asked whether this skill would also be demonstrated by young team players. In the current study, junior football players (M age = 10.0 yr., SD = 0.8, N = 13) viewed 400-msec. video clips of runners sprinting past a fixed forward facing digital video camera and similarly showed teammate recognition scores significantly above chance. Given the variation among the junior players in this skill, it seems possible for researchers to assess whether improvement can be obtained with structured training for young team players, where running teammates are seen in peripheral vision during training drills.

  9. Statistical properties for directional alignment and chasing of players in football games

    Science.gov (United States)

    Narizuka, Takuma; Yamazaki, Yoshihiro

    2016-12-01

    Focusing on motion of two interacting players in football games, two velocity vectors for the pair of one player and the nearest opponent player exhibit strong alignment. Especially, we find that there exists a characteristic interpersonal distance r≃ 500 \\text{cm} below which the circular variance for their alignment decreases rapidly. By introducing the order parameter φ(t) in order to measure the degree of alignment of the players' velocity vectors, we also find that the angle distribution between the nearest players' velocity vectors becomes of wrapped Cauchy type (φ ≲ 0.7) and the mixture of von Mises and wrapped Cauchy distributions (φ ≳ 0.7) , respectively. To understand these findings, we construct a simple model for the motion of the two interacting players with the following rules: chasing between the players and the reset of the chasing. We numerically show that our model successfully reproduces the results obtained from the actual data. Moreover, from the numerical study, we find that there is another characteristic distance r≃ 1000 \\text{cm} below which player's chasing starts.

  10. A COMPARATIVE STUDY OF PERSONALITY OF INTERNATIONAL VOLLEYBALL PLAYERS OF BRAZIL AND INDIA

    Directory of Open Access Journals (Sweden)

    Govind Kadam

    2010-06-01

    Full Text Available The main objective was to study the personality of the volleyball players of India. All the players of Indian team and the players of Brazil team, who came for FIVB Men Volleyball World Championship held at Pune in August 2009, were selected for the study. They were administered the Cattell’s 16 PF questionnaire. The results wereanalyzed with the help of ‘t’ test which showed that there are significant differences found between Indian volleyball players and Brazilian Volleyball players on seven factors but not on nine factors of 16 PF Questionnaire. Indian players scored high on factor ‘F’, factor ‘I’ and factor ‘M’ whereas Brazilian players have scored high on factor ‘B’, factor ‘G’, factor ‘H’ and factor ‘L’. Indian players scored low on Factor B which means that they tend to be slow to learn and grasp and they were dull as compared with Brazilian team, and gives concrete and literal interpretation. This dullness simply represents poor functioning.

  11. DIFFERENCES IN TECHNICAL MOVEMENT PRECISION WITH BALL TO NEW AGES SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Sami Sermaxhaj

    2015-05-01

    Full Text Available The primary goal of this research is to compare the accuracy of the collision of the ball to players of both age groups U-17 and U-19. The research was conducted on a sample of 100 young soccer players Kosovo divided into two groups: the first group comprised of 50 young players U17 and second group comprised of 50 young soccer players U-19. To assess the precision of the attack on the ball all the players they have subjected technical demonstration testing in four tests: (T-JUGGL, T-PASI, T-KROS, T-SHOOT. Through T-test method are proven differences in favor of players U-19 to U-17 in all tests of precision technical movements with the ball, but statistically significant differences are shown in the collision test at the gateway (T-SHOOT and the test ball juggling (T-JUGGL . The results obtained show us that more experienced players U-19 have a better precision in demonstrating the technical movements with the ball, compared to U-17 players. Assuming that the training process is very important to voice learning, mastering demonstration, acquisition, and precise technical movements with the ball, because the precision peak levels is very significant.

  12. Movement Demands of Elite U20 International Rugby Union Players

    Science.gov (United States)

    Drawer, Scott; Eager, Robin; Taylor, Neil; Cook, Christian

    2016-01-01

    The purpose of this study was to quantify movement demands of elite international age grade (U20) rugby union players during competitive tournament match play. Forty elite professional players from an U20 international performance squad were monitored using 10Hz global positioning systems (GPS) during 15 international tournament matches during the 2014/15 and 2015/16 seasons. Data on distances, velocities, accelerations, decelerations, high metabolic load (HML) distance and efforts, and number of sprints were derived. Data files from players who played over 60 min (n = 161) were separated firstly into Forwards and Backs, and more specifically into six positional groups; FR—Front Row (prop & hooker), SR—Second Row, BR—Back Row (Flankers & No.8), HB—Half Backs (scrum half & outside half), MF—Midfield (centres), B3 –Back Three (wings & full back) for match analysis. Analysis revealed significant differences between forwards and backs positions. Backs scored higher on all variables measured with the exception of number of moderate accelerations, decelerations (no difference). The centres covered the greatest total distance with the front row covering the least (6.51 ± 0.71 vs 4.97 ± 0.75 km, p rugby union players specific to positional roles. PMID:27055230

  13. Player-character dynamics in multi-player Role Playing Games

    DEFF Research Database (Denmark)

    Tychsen, Anders; McIlwain, Doris; Brolund, Thea

    2007-01-01

    This paper presents the results of a comprehensive empirical study of the impact of integrating complex game characters in multi-player Role Playing Games across tabletop and digital formats. Players were provided with characters that had detailed background history, personality and goals. Player...... and player engagement with their character and no correlation between enjoyment and similarity between player and character personality. © 2007 Authors & Digital Games Research Association (DiGRA)....... and character personality were assessed using the Extended Personal Attributes Questionnaire (EPAQ) and further questionnaires administered to measure player enjoyment and the player-character relationship. Results include a high level of player enjoyment across all formats, a high correlation between enjoyment...

  14. An investigation of player to player character identification via personal pronouns

    DEFF Research Database (Denmark)

    Hichens, Michael; Drachen, Anders; Richards, Deborah

    2012-01-01

    The player character is an important feature of many games, where it is through the character that the player interacts with game world. There has been considerable interest in the relationship between the player and the player character. Much of this work has examined the identification of players...... in playing video games, did have a statistically significant affect, indicating that different levels of identification are more dependent on the player than on the game. This indicates that players are not a homogeneous group with respect to player character identification and is an important consideration...... with their characters, generally taking either a textual analysis approach, or has been empirical work that has explicitly identified the idea of identification through survey instruments, etc. The work presented here takes a different empirical approach, focusing on the use of various pronoun forms (first, second...

  15. Seasonal Variation in Objectively Assessed Physical Activity among Young Norwegian Talented Soccer Players: A Description of Daily Physical Activity Level.

    Science.gov (United States)

    Sæther, Stig A; Aspvik, Nils P

    2014-12-01

    'Practise makes perfect' is a well-known expression in most sports, including top-level soccer. However, a high training and match load increases the risk for injury, overtraining and burnout. With the use of accelerometers and a self-report questionnaire, the aim of this study was to describe talented players' physical activity (PA) level. Data were collected three times during the 2011 Norwegian Football season (March, June and October). The accelerometer output, counts·min(-1) (counts per unit time registered), reports the daily PA-level for young talented soccer players. Results showed a stable PA-level across the season (March: 901.2 counts·min(-1), June: 854.9 counts·min(-1), October: 861.5 counts·min(-1)). Furthermore, comparison of five different training sessions across the season showed that the PA-level ranged from 2435.8 to 3745.4 counts·min(-1). A one-way ANOVA showed no significant differences between the three measured weeks during the soccer season (p≤0.814). However, the training sessions in January had a significantly higher PA-level than those in June and October (p≤0.001). Based on these results, we discuss how potential implications of PA-level affect factors such as risk of injury, overtraining and burnout. We argue that player development must be seen as part of an overall picture in which club training and match load should be regarded as one of many variables influencing players' PA-level. Key pointsIt is well established that to achieve a high performance level in sport, one must implement a high training and match load in childhood and youth.With the use of accelerometers and a self-reported questionnaire, the aim of this study was to describe talented players' total physical activity (PA) load.These results indicate that young talented soccer players must overcome large doses of PA on a weekly basis, exposing them to a high risk of injury, overtraining and burnout.

  16. Serious eye injury in badminton players.

    Science.gov (United States)

    Kelly, S P

    1987-10-01

    Serious eye injury can occur in badminton players and may become more frequent. The causes and nature of such injuries in this sport in six patients are discussed. All were playing competitive doubles matches. Penetrating eye injury due to a shattered glass spectacle lens occurred. Players should be advised not to wear spectacles with glass lenses. Ocular protection in this sport is desirable, and the forward player should hold the racket in front of the face.

  17. The Prevalence of Injuries in Professional Turkish Soccer Players

    Science.gov (United States)

    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…

  18. Radiographic knee osteoarthritis in ex-elite table tennis players

    Directory of Open Access Journals (Sweden)

    Rajabi Reza

    2012-02-01

    Full Text Available Abstract Background Table tennis involves adoption of the semi-flexed knee and asymmetrical torsional trunk movements creating rotational torques on the knee joint which may predispose players to osteoarthritis (OA of the knee. This study aims to compare radiographic signs of knee OA and associated functional levels in ex-elite male table tennis players and control subjects. Methods Study participants were 22 ex-elite male table tennis players (mean age 56.64 ± 5.17 years with 10 years of involvement at the professional level and 22 non-athletic males (mean age 55.63 ± 4.08 years recruited from the general population. A set of three radiographs taken from each knee were evaluated by an experienced radiologist using the Kellgren and Lawrence (KL scale (0-4 to determine radiographic levels of OA severity. The intercondylar distance was taken as a measure of lower limb angulation. Participants also completed the pain, stiffness, and physical function categories of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC 3.1 questionnaire. Results The results showed 78.3% of the ex-elite table tennis players and 36.3% of controls had varying signs of radiographic knee OA with a significant difference in the prevalence levels of definite radiographic OA (KL scale > 2 found between the two groups (P ≤ 0.001. Based on the WOMAC scores, 68.2% of the ex-elite table tennis players reported symptoms of knee pain compared with 27.3% of the controls (p = 0.02 though no significant differences were identified in the mean physical function or stiffness scores between the two groups. In terms of knee alignment, 73.7% of the ex-elite athletes and 32% of the control group had signs of altered lower limb alignment (genu varum (p = 0.01. Statistical differences were found in subjects categorized as having radiographic signs of OA and altered lower limb alignment (p = 0.03. Conclusions Ex-elite table tennis players were found to have increased

  19. Chess players' fame versus their merit

    CERN Document Server

    Simkin, M V

    2015-01-01

    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 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.

  20. Physiological characteristics of international female soccer players.

    Science.gov (United States)

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p velocity (ES = 0.78-2.45, p velocity (ES = 0.87, p players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.

  1. Increasing mouthguards usage among junior rugby and basketball players.

    Science.gov (United States)

    Jalleh, G; Donovan, R J; Clarkson, J; March, K; Foster, M; Giles-Corti, B

    2001-06-01

    To evaluate a Western Australian mouthguard promotion campaign, launched at the start of the 1997/98 junior rugby union and junior basketball seasons, aimed at increasing mouthguard usage at competition and training. A quasi-experimental field design was used to assess the impact of the mouthguard campaign on behavioural change. Observational data were collected pre- and post-campaign on mouthguard usage by players present at a rugby and basketball competition event and at a training session. Junior Australian Rules Football players were used as a control group. Pre-post observational surveys showed a significantly greater increase in mouthguard usage in competition games among rugby union (77% to 84%) and basketball players (23% to 43%) compared with the control group (72% to 73%). All codes showed a post-campaign increase in mouthguard usage at training, but the intervention codes' increases were greater than the control's increase (rugby union: 29% to 40%; basketball: 11% to 36%; football: 34% to 40%). The campaign had a significant and substantial effect on behaviour and provides evidence of the benefits of leveraging a sponsorship to modify the behaviour of the target group. This campaign provides a model for promoting mouthguard usage in other sports among junior players.

  2. Positional demands of international rugby union: evaluation of player actions and movements.

    Science.gov (United States)

    Quarrie, Kenneth L; Hopkins, Will G; Anthony, Mike J; Gill, Nicholas D

    2013-07-01

    In rugby union, published analyses of actions and movements of players during matches have been limited to small samples of games at regional or national level. To analyse movements and activities of players in international rugby union matches with a sample size sufficient to clearly delineate positional roles. Observational study. Actions of 763 players were coded from video recordings of 90 international matches played by the New Zealand national team (the All Blacks) from 2004 to 2010. Movements of players were coded for 27 of these matches via a semi-automated player-tracking system. Movements and activities of all players from both teams were coded. Cluster analysis of activities and time-motion variables produced five subgroups of forwards (props, hookers, locks, flankers, Number 8 forwards) and five subgroups of backs (scrum-half, fly-half, midfield backs, wings and fullbacks). Forwards sustained much higher contact loads per match than backs, via scrums, rucks, tackles and mauls. Mean distance covered per match ranged from 5400 to 6300m, with backs generally running further than forwards. There were marked differences between positional groups in the amount of distance covered at various speeds. The amount of play per match varies by position due to differences in rates at which players are substituted. The distance covered by players at relatively fast running speeds (in excess of 5ms(-1)) appears to be higher during international matches than when competing at lower levels of the professional game. The specific match demands for positional groups need to be considered when managing player workloads. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. Match intensity and pacing strategies in rugby league: an examination of whole-game and interchanged players, and winning and losing teams.

    Science.gov (United States)

    Black, Georgia M; Gabbett, Tim J

    2014-06-01

    There is currently limited information on whether pacing occurs during rugby league match play. In addition, to date no research has investigated whether pacing strategies differ between winning and losing teams. This study investigated the pacing strategies of whole-game and interchanged rugby league players. Furthermore, we investigated the pacing strategies of winning and losing teams. Fifty-two rugby league players, from a sample of 11 teams competing in a semi-elite competition, underwent global positioning system analysis. Performances were divided into match quartiles for whole-game and interchanged players. Total distance, including low- and high-speed distances, and repeated high-intensity effort bouts were recorded. The total distance and low-speed distance covered across all quartiles of the match, but specifically quartiles 1 and 8, were greater for interchanged players than whole-game players. The match outcome differentially affected the pacing strategies of whole-game and interchanged players. Whole-game players from winning teams set a higher pacing strategy than whole-game players from losing teams (effect size [ES] = 1.03 ± 0.77, 96%, very likely), whereas interchanged players from losing teams demonstrated a greater "end-spurt" than interchanged players from winning teams (ES = 0.60 ± 0.52, 96%, very likely). The pacing strategies of interchanged players were higher than whole-game players, irrespective of playing position. The results of this study suggest that pacing strategies differ between interchanged and whole-game rugby league players. Furthermore, our results demonstrate a different pacing strategy between winning and losing teams. These findings suggest that physical preparation for rugby league matches, and recovery from these matches, should be individualized for whole-game and interchanged players. Finally, performing physically intense training on a regular basis is likely to develop the physical and mental qualities required to

  4. Spermatozoa in the sperm-peak-fraction of the boar ejaculate show a lower flow of Ca(2+) under capacitation conditions post-thaw which might account for their higher membrane stability after cryopreservation.

    Science.gov (United States)

    Hossain, Md Sharoare; Johannisson, Anders; Siqueira, Amanda Pimenta; Wallgren, Margareta; Rodriguez-Martinez, Heriberto

    2011-10-01

    Boar spermatozoa collected in the ejaculate sperm peak-portion (P1, first 10 mL of the sperm-rich fraction, SRF), had shown a higher resilience to freezing and thawing compared to spermatozoa from the rest of the ejaculate (2nd portion of the SRF plus the post-sperm-rich fraction, PSRF), even when using a simplified freezing technique, as long as spermatozoa were incubated in their own seminal plasma (SP). This experiment studied the stability of P1- and SRF-P1 boar spermatozoa frozen in MiniFlatPacks (MFP), post-thaw, using flow cytometry. Since spermatozoa from either portion showed similar cryosurvival and low proportions of unstable membranes (<3%, annexin-V/propidium iodide staining), and only a tendency for SRF-P1 live spermatozoa to depict acrosome exocytosis (FITC-PNA/PI/H33342); they were explored for Ca(2+) contents using a Fluo-4 probe under in vitro capacitating conditions (mBO+ medium), as well they were tested for their ability to sustain a short Ca(2+)-ionophore (A23187) in vitro challenge. The proportions of live spermatozoa depicting high Ca(2+)-levels were initially <2% but increased over incubation time, particularly in SRF-P1(P<0.05), while proportions of live spermatozoa with low Ca(2+)-levels were basically constant over incubation time (~11-14%), for either portion. Incubation in capacitation medium did not modify the proportions of low-Ca(2+) but dramatically increased the proportions of high-Ca(2+) spermatozoa (P<0.001) already after 15 min exposure, highest for SRF-P1 spermatozoa. While the proportion of live spermatozoa with intact acrosome was significantly decreased among SRF-P1 (P<0.001), that of P1-spermatozoa remained unchanged, probably owing to the lowest relative content of cytosolic Ca(2+). The results suggest that spermatozoa in the P1-portion are more resilient to express acrosome exocytosis post-thaw compared to those bathing in the rest of the SRF-fraction when cryopreserved using a simplified technique, in MFPs.

  5. [ANTHROPOMETRIC CHILEAN TABLE TENNIS PLAYERS OF COMPETITIVE FEATURES].

    Science.gov (United States)

    Yáñez Sepúlveda, Rodrigo; Barraza, Fernando; Rosales Soto, Giovanni; Báez, Eduardo; Tuesta, Marcelo

    2015-10-01

    The aim of the study was to characterize the anthropometric profile and somatotype of a sample of 50 players table tennis competitive with an average age 21.6 (± 3.1) years belonging to the Chilean team and institutions of higher education in the region of Valparaiso. The evaluation was conducted under the protocol marking the International Society for the Advancement of Kinanthropometry (ISAK) for the measurement procedure 25 restricted profile variables described by Drinkwater, Norton and Olds. Order to determine the body composition, fat, muscle, bone, skin and tissue residual was considered, using the equations proposed by Kerr. The body shape is characterized through somatotype method proposed by Carter. The sample was divided into 4 groups; Chilean Selection, Traditional Private Universities, State Universities and Private Universities Traditional Nontraditional. Regarding body composition; the Chilean team has the highest values of muscle tissue (45.6 ± 1.7%) and the lowest values of adipose tissue (25.2 ± 1.8%), also presenting lesser value in the Σ 6 skinfolds (mm) . The results showed no significant differences between groups in the aforementioned variables. In general somatotype compared by analyzing SANOVA no significant differences between groups (p = 0.409) was observed. The results show a biotype with such a characterization of endo-mesomorph with average values (4,1-4,9-1,8). This study provides updated data biotypological reference for this sport that can be used for decision-making.

  6. Athletic Cardiac Remodeling in US Professional Basketball Players.

    Science.gov (United States)

    Engel, David J; Schwartz, Allan; Homma, Shunichi

    2016-04-01

    The incidence of sudden cardiac death is higher in US basketball players compared with other athlete groups. However, the recognition of the risk for sudden cardiac death among basketball players is challenging because little is known regarding athletic cardiac remodeling in these athletes or athletes of similarly increased size. To perform a comprehensive cardiac structural analysis of National Basketball Association (NBA) professional athletes. Echocardiographic observational study of NBA players on the active rosters for the 2013-2014 and 2014-2015 seasons was performed from December 16, 2013, to December 12, 2014. The policy of the NBA mandates annual preseason stress echocardiograms for each player. The NBA has sanctioned Columbia University Medical Center to conduct annual health and safety reviews of these echocardiograms. Data were analyzed from January to May 2015. Cardiac variables assessed included left ventricular (LV) size, mass, wall thickness, and hypertrophy patterns and function; left atrial volume; and aortic root diameter. All dimensions were biometrically scaled. Of the 526 athletes included in the study, 406 (77.2%) were African American and 107 (20.3%) were white, with a mean (SD) age of 25.7 (4.3) years. Mean (SD) athlete height was 200.2 (8.8) cm; mean body surface area, 2.38 (0.19) m2. Left ventricular size and mass in NBA athletes were proportional to body size, extending to the uppermost biometrics of the cohort. Left ventricular hypertrophy was present in 144 athletes (27.4%). African American athletes had increased LV wall thickness (unadjusted mean, 11.2 mm; 95% CI, 11.1-11.3 mm) and LV mass (unadjusted mean, 106.3 g/m2; 95% CI, 104.6-108.0 g/m2) compared with LV wall thickness (unadjusted mean, 10.5 mm; 95% CI, 10.3-10.7 mm; P basketball players and the athletic community at large.

  7. Variation in the Ace Gene in Elite Polish Football Players

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    Cięszczyk Paweł

    2016-12-01

    Full Text Available Purpose. A common polymorphism in the angiotensin converting enzyme I gene (the ACE I/D variant represents one of the first characterized and the most widely studied genetic variants in the context of elite athletes status and performance related traits. The aim of the study was to determine the genotype and allele distribution of the allele and genotype of the ACE gene in Polish male football players. Methods. The total of 106 Polish male professional football players were recruited. They were divided into groups according to the position in the field: forwards, defenders, midfielders, and goalkeepers. For controls, samples were prepared with 115 unrelated volunteers. DNA was extracted from the buccal cells donated by the subjects, and the PCR amplification of the polymorphic region of the ACE gene containing either the insertion (I or deletion (D fragment was performed. Results. The genotype distribution and allele frequencies among all football players did not differ significantly when compared with sedentary control individuals (p = 0.887, p = 0.999, respectively. Likewise, the analysis of forwards, defenders, midfielders, and goalkeepers revealed no significant differences in either ACE genotype or allele frequencies. Conclusions. We did not provide evidence for difference of variation of the ACE I/D polymorphism between Polish football players and controls, as we did not obtain any statistically significantly higher frequency of either of the analysed alleles (I and D or genotypes (DD, ID, and II in the studied subgroups. It may be suspected that harbouring of I/D allelic variants of the ACE gene neither decreases nor increases the probability of being a professional football player in Poland.

  8. Comparison of the Anthropometric and Physical Characteristics of International and Provincial Rugby Sevens Players.

    Science.gov (United States)

    Ross, Alex; Gill, Nicholas D; Cronin, John B

    2015-09-01

    Anthropometrical and physical characteristics have been used to distinguish players of different competition levels and position groups; however, there is no literature on rugby sevens. To compare the anthropometrical and physical characteristics of international and provincial rugby sevens players and between forwards and backs. To assess whether differences exist, 65 rugby sevens players including 22 international players and 43 provincial-level players were assessed for height, mass, body composition, speed, repeated-sprint ability, lower-body power, upper-body strength, and maximal aerobic endurance during in-season preparation for tournaments. Clear differences (2.8-32%; small to very large effect sizes) were observed in all anthropometrical and physical measures between international and provincial players, with the largest differences observed in repeated-sprint ability (5.7%; very large effect size), 40-m-sprint time (4.4%; large effect size), 50-kg squat-jump peak power (32%; large effect size), and multistage fitness-test performance (19%; large effect size). Fewer and smaller differences (0.7-14%; trivial to large effect sizes) were found when comparing forwards and backs, with body height being the most discriminant characteristic (3.5%; large effect size). Lower-level rugby sevens players should seek to improve their overall physical profile, particularly their repeated-sprint ability, to reach higher levels in rugby sevens. Furthermore, positional status may have little importance when preparing for rugby sevens.

  9. Correspondence between training load executed by volleyball players and the one observed by coaches.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Medina, Javier; García-López, Juan; García-Tormo, José V; Foster, Carl

    2014-06-01

    The main aim of this study was to compare the training load (TL) executed by volleyball players with that observed by coaches. Second, we analyzed the influence of the coaches' experience in the estimated TL. Twelve female volleyball players and 4 male coaches participated in this study. During a period of 15 weeks, physical (PT) and technical-tactical training sessions and matches were monitored. In each session, the session rating of perceived exertion (sRPE) was recorded to analyze the players' exercise intensity and TL(RP)E. Coaches were present in all sessions and rated their estimate of sRPE at the same time as the players to calculate the coaches' TL(RPE). Both players' and coaches' mean sRPE (4.0 ± 1.1, 3.7 ± 1.1, and 3.8 ± 1.0 in players and expert and beginning coaches, respectively) and TLRPE (380.1 ± 106.8, 358.3 ± 110.5, and 359.7 ± 108.0 in players and expert and beginning coaches, respectively) were similar. However, a higher (p volleyball.

  10. Doping in Turkey, assessment of knowledge level of players about doping (handball study case

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    Elif Gönül Öztürk

    2012-01-01

    Full Text Available The purpose of this study is to discuss doping in Turkey and to assess the knowledge level of handball players in Turkey. Sample in this study is composed of 148 players who have been selected randomly among 336 players from 24 teams (12 men - 12 women that were competing in the season 2007-2008.A questionaire prepared by expert opinion is employed as the data collection method. First the questionaire is applied to a group of 40 handball players, then the questions are revised according to the answers given by this specific group of players and validity-reliability tests are conducted. Reliability test is performed by using Cronbach Alpha internal consistency technique and the coefficient is obtained as 0.82.In this study, literature survey has been conducted to examine the historical progress of doping which has been verified with numerical data. According to the results of percentage (% and frequency (f, t-test and ANOVA, 50.7% (N=75 of the contributors is “male” whereas the remaining 49.3% (N=73 of the contributors is “female”.As a conclusion of this study, it can be stated that the knowledge level of handball players about doping is limited and the knowledge level of men seems to be higher than the knowledge level of women. It is also revealed that some players have been using doping.

  11. Aerobic Development of Elite Youth Ice Hockey Players.

    Science.gov (United States)

    Leiter, Jeff R; Cordingley, Dean M; MacDonald, Peter B

    2015-11-01

    Ice hockey is a physiologically complex sport requiring aerobic and anaerobic energy metabolism. College and professional teams often test aerobic fitness; however, there is a paucity of information regarding aerobic fitness of elite youth players. Without this knowledge, training of youth athletes to meet the standards of older age groups and higher levels of hockey may be random, inefficient, and or effective. Therefore, the purpose of this study was to determine the aerobic fitness of elite youth hockey players. A retrospective database review was performed for 200 male AAA hockey players between the ages of 13 and 17 (age, 14.4 ± 1.2 years; height, 174.3 ± 8.5 cm; body mass, 67.2 ± 11.5 kg; body fat, 9.8 ± 3.5%) before the 2012-13 season. All subjects performed a graded exercise test on a cycle ergometer, whereas expired air was collected by either a Parvo Medics TrueOne 2400 or a CareFusion Oxycon Mobile metabolic cart to determine maximal oxygen consumption (V[Combining Dot Above]O2max). Body mass, absolute V[Combining Dot Above]O2max, and the power output achieved during the last completed stage increased in successive age groups from age 13 to 15 years (p ≤ 0.05). Ventilatory threshold (VT) expressed as a percentage of V[Combining Dot Above]O2max and the heart rate (HR) at which VT occurred decreased between the ages of 13 and 14 years (p ≤ 0.05), whereas the V[Combining Dot Above]O2 at which VT occurred increased from the age of 14-15 years. There were no changes in relative V[Combining Dot Above]O2max or HRmax between any successive age groups. The aerobic fitness levels of elite youth ice hockey players increased as players age and mature physically and physiologically. However, aerobic fitness increased to a lesser extent at older ages. This information has the potential to influence off-season training and maximize the aerobic fitness of elite amateur hockey players, so that these players can meet standards set by advanced elite age groups.

  12. Instrumented mouthguard acceleration analyses for head impacts in amateur rugby union players over a season of matches.

    Science.gov (United States)

    King, Doug; Hume, Patria A; Brughelli, Matt; Gissane, Conor

    2015-03-01

    Direct impacts with the head (linear acceleration or pressure) and inertial loading of the head (rotational acceleration or strain) have been postulated as the 2 major mechanisms of head-related injuries such as concussion. Although data are accumulating for soccer and American football, there are no published data for nonhelmeted collision sports such as rugby union. To quantify head impacts via instrumented mouthguard acceleration analyses for rugby union players over a season of matches. Descriptive epidemiology study. Data on impact magnitude and frequency were collected with molded instrumented mouthguards worn by 38 premier amateur senior rugby players participating in the 2013 domestic season of matches. A total of 20,687 impacts >10g (range, 10.0-164.9g) were recorded over the duration of the study. The mean ± SD number of impacts per player over the duration of the season of matches was 564 ± 618, resulting in a mean ± SD of 95 ± 133 impacts to the head per player, per match over the duration of the season of matches. The impact magnitudes for linear accelerations were skewed to the lower values (Sp = 3.7 ± 0.02; P rugby union players over a season of matches, measured via instrumented mouthguard accelerations, were higher than for most sports previously reported. Mean linear acceleration measured over a season of matches was similar to the mean linear accelerations previously reported for youth, high school, and collegiate American football players but lower than that for female youth soccer players. Mean rotational acceleration measured over a season of matches was similar to mean rotational accelerations for youth, high school, and collegiate American football players but less than those for female youth soccer players, concussed American collegiate players, collegiate American football players, and professional American football players. © 2014 The Author(s).

  13. Mental health and social participation skills of wheelchair basketball players: a controlled study.

    Science.gov (United States)

    Fiorilli, Giovanni; Iuliano, Enzo; Aquino, Giovanna; Battaglia, Claudia; Giombini, Arrigo; Calcagno, Giuseppe; di Cagno, Alessandra

    2013-11-01

    The aim of this study was to assess differences in psychological well-being, symptomatic psychological disorders and social participation, between competitive wheelchair basketball participants and those non-participants. Forty-six wheelchair participants, 24 Basketball players (aged 35.60 ± 7.56) and 22 non-players (aged 36.20 ± 6.23), completed three validated self-report questionnaires: Participation Scale (PS), Psychological Well-Being Scale [PWBS] and Symptom Checklist 90 R [SCL-90-R]. ANOVA showed significant overall differences between the two groups. The social restriction score, evaluated by PS, was significantly higher in the non-basketball participants (p=0.00001) than the basketball participants. The PWB Scale showed significant differences in all 6 dimensions: positive relations with others, environmental mastery, personal growth, purpose in life and self-acceptance (pbasketball participants. The SCL-90-R scores were significantly lower for the basketball group in the following 6 symptomatic dimensions: depression, phobic anxiety, and sleep disorder (pbasketball participants showed better psychological well-being and social skills than those non-participants.

  14. Relationship between upper-body strength and bat swing speed in high-school baseball players.

    Science.gov (United States)

    Miyaguchi, Kazuyoshi; Demura, Shinich

    2012-07-01

    This study aimed to clarify the relationship between upper-body strength and bat swing speed in high-school baseball players and to examine the physical characteristics of home run hitters (sluggers). The subjects were 30 male high-school baseball players with national tournament experience at the Koshien Stadium. Bat swing speed exerted by full effort was measured with a microwave-type speed-measuring instrument. One-repetition maximum (1RM) of a bench press (BP), BP power (bench power) using a light load (30 kg), and isokinetic chest press (0.4, 0.8, 1.2 m·s(-1)) were measured as upper-body strength. The relationships between bat swing speed and upper-body strength values were examined. Additionally, the t-test was used to reveal the mean differences between 14 home run hitters (group A) and 16 mediocre hitters (group B) for each measurement value. The bat swing speed showed significant and middle correlations with the 1RM BP (r = 0.59), bench power (0.41), and isokinetic chest press (0.48-0.55). Group A had significantly higher values in bench power and isokinetic chest press (high-speed) per kilogram of body weight than did group B. The swing speed showed significant correlations (r = 0.62) with the 1RM BP in group B but not in group A. In conclusion, to improve the hitting power of high-school baseball players, it may also be important to develop bench power with light loads in addition to 1RM BP.

  15. Cooperation: New Players in Africa

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    Philippe Hugon

    2010-03-01

    Full Text Available In the context of globalisation and the current global financial crisis, new players are emerging in cooperation in Africa. These partners loosen financial constraints and conditionalities, increase the room for manoeuvre and stimulate commodity markets. On the other hand, they also increase the risks of renewed indebtedness and potentially weaken the coordination of aid policies. Do these partnerships call the new cooperation practices of OECD countries into question? Do they justify the return to a realpolitik or are they repeating the earlier mistakes of industrial powers? Can these mistakes be corrected? The question also arises as to whether the global crisis, which has a profound effect on Africa, will lead to a withdrawal or to a passing of the baton on to new, emerging powers. This article highlights the new geopolitical issues concerning Africa in a multipolar world, then discusses the new players involved in cooperation in Africa, before going on to explore the horizons that are opening up for cooperation in Africa, in particular with regard to the global crisis.

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

    Science.gov (United States)

    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.

  17. Somatotype of Competitive Youth Soccer Players From Brazil

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    Fidelix Yara Lucy

    2014-10-01

    Full Text Available The aim of this study was to identify the morphological configuration of youth athletes from professional soccer clubs and to verify their differences according to the tactical position on the field. Overall, 67 male players aged 15 to 17 years were evaluated. The examined anthropometric measurements included body mass, body height, skinfolds (triceps, subscapular, supraspinal and medial calf, girths (flexed and tensed arm and calf and breadths (humerus and femur. For statistical purposes, analysis of variance and post hoc Bonferroni and Kruskal-Wallis tests were used. We concluded that goalkeepers were heavier and taller than center backs (p = 0.015 and p = 0.001, midfielders (p = 0.005 and p <0.001 and center forward players (p = 0.024 and p <0.001. The average somatotype for defense, forward and goalkeeper positions was a balanced mesomorph. Midfield players showed ectomorphic-mesomorph characteristics. It was concluded that goalkeepers were characterized as being taller and heavier and that somatotype features of athletes were similar between positions, except for midfield players

  18. Analysis of football player's motion in view of fractional calculus

    Science.gov (United States)

    Couceiro, Micael; Clemente, Filipe; Martins, Fernando

    2013-06-01

    Accurately retrieving the position of football players over time may lay the foundations for a whole series of possible new performance metrics for coaches and assistants. Despite the recent developments of automatic tracking systems, the misclassification problem (i.e., misleading a given player by another) still exists and requires human operators as final evaluators. This paper proposes an adaptive fractional calculus (FC) approach to improve the accuracy of tracking methods by estimating the position of players based on their trajectory so far. One half-time of an official football match was used to evaluate the accuracy of the proposed approach under different sampling periods of 250, 500 and 1000 ms. Moreover, the performance of the FC approach was compared with position-based and velocity-based methods. The experimental evaluation shows that the FC method presents a high classification accuracy for small sampling periods. Such results suggest that fractional dynamics may fit the trajectory of football players, thus being useful to increase the autonomy of tracking systems.

  19. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

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    Wieczorek Marta

    2015-12-01

    Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  20. Effect of the pitch size and presence of goalkeepers on the work load of players during small-sided soccer games

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    Hulka Karel

    2016-06-01

    Full Text Available Small-sided games (SSGs are spontaneous forms of specific training where exercise intensity can be manipulated by modifying external factors. To ensure suitable usage of small-sided games in practice, we have to know which variables can influence internal responses and external loads. The aim of the present study was to determine the influence of presence of a goalkeeper and the pitch size on internal responses and the external load during five-a-side soccer games. Twenty nine junior soccer players (age: 18.11 ± 1.31 years; body mass index: 21.04 ± 2.58 kg·m-2; peak heart rate: 199.53 ± 7.51 beats·min–1 participated in the study. The heart rate, distance covered and the rate of perceived exertion were monitored. We found significantly higher average heart rates of players in 5v5 SSGs without goalkeepers than with them on a small pitch. Analysis showed significant differences in the time spent in 65-85% of the peak heart rate zone and ˂65% of the peak heart rate zone on the small pitch. Furthermore, we found significantly higher distance covered by players during five-a-side games with goalkeepers than without them played on the small pitch. Our results indicate that the pitch size is a very important variable that influences the work load of players. The inclusion of the goalkeeper decreases the work load of the player on a small pitch (28 × 20 m; 560 m2, but not on a medium or large pitch.

  1. No association between static and dynamic postural control and ACL injury risk among female elite handball and football players: a prospective study of 838 players.

    Science.gov (United States)

    Steffen, Kathrin; Nilstad, Agnethe; Krosshaug, Tron; Pasanen, Kati; Killingmo, Aleksander; Bahr, Roald

    2017-02-01

    Research on balance measures as potential risk factors for ACL injury is limited. To assess whether postural control was associated with an increased risk for ACL injuries in female elite handball and football players. Premier league players were tested in the preseason and followed prospectively for ACL injury risk from 2007 through 2015. At baseline, we recorded player demographics, playing experience, ACL and ankle injury history. We measured centre of pressure velocity in single-leg stabilisation tests and reach distances in the Star Excursion Balance Test. To examine the stability of postural control measures over time, we examined their short-term and long-term reproducibility. We generated logistic regression models, 1 for each of the proposed risk factors. A total of 55 (6.6%) out of 838 players (age 21±4 years; height 170±6 cm; body mass 66±8 kg) sustained a non-contact ACL injury after baseline testing (1.8±1.8 years). When comparing normalised balance measures between injured and uninjured players in univariate analyses, none of the variables were statistically associated with ACL injury risk. Short-term and long-term reproducibility of the selected variables was poor. Players with a previous ACL injury had a 3-fold higher risk of sustaining a new ACL injury compared with previously uninjured players (OR 2.9, CI 1.4 to 5.7). None of postural control measures examined were associated with increased ACL injury risk among female elite handball and football players. Hence, as measured in the current investigation, the variables included cannot be used to predict ACL injury risk. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Javier Yanci

    2014-11-01

    Full Text Available The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball agility (T-test and pick-up test strength (handgrip and maximal pass and endurance (Yo-Yo 10 m recovery test were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94. The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s and maximal pass (8.39 ± 1.77 m, players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB.

  3. Features of physiological responses on organism of football players aged 10-12 years in exercise using different training methods

    Directory of Open Access Journals (Sweden)

    Abdula A. B.

    2014-01-01

    Full Text Available Purpose : To evaluate the effect of various special exercises football players’ organism in different modes. Material : The study involved 24 young players aged 10-12 years. Results : There is a large range of load parameters for elite athletes, which necessitates evaluation exercise intensity football for young players. Found that depending on the method chosen football special exercises have different effects on the body force young players. Conclusions : It was found that by using the method of competitive gaming and heart rate and energy increases with increasing number of players. The analysis shows the existence of significant differences in terms of heart rate for game and interval method.

  4. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems, such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  5. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems,such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  6. Who Are the Players in Canadian Curriculum?

    Science.gov (United States)

    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 ideas/concepts, examination of current policies, awareness of history…

  7. QuizUp Single Player Web

    OpenAIRE

    Gunnar Marteinsson 1983; Kristinn Júlíusson 1993; Sonja Jónsdóttir 1992; Steinar Þór Árnason 1993

    2016-01-01

    In this report we discuss the B.Sc. project named QuizUp Single Player Web. The project was developed at Reykjavik University in the spring of 2016 in collaboration with Plain Vanilla Games, the makers of the world famous QuizUp app. We developed a Single Player Web application based on the original multiplayer game.

  8. Inferring Player Experiences Using Facial Expressions Analysis

    NARCIS (Netherlands)

    Tan, C.T.; Bakkes, S.; Pisan, Y.; Blackmore, K.; Nesbitt, K.; Smith, S.P.

    2014-01-01

    Understanding player experiences is central to game design. Video captures of players is a common practice for obtaining rich reviewable data for analysing these experiences. However, not enough has been done in investigating ways of preprocessing the video for a more efficient analysis process. Thi

  9. FUNCTIONAL STATUS AND INFLAMMATION AFTER PRESEASON TRAINING PROGRAM IN PROFESSIONAL AND RECREATIONAL SOCCER PLAYERS: A PROTEOMIC APPROACH

    Directory of Open Access Journals (Sweden)

    Francisco J. Martín-Sánchez

    2011-03-01

    Full Text Available The purpose of the study was to determine if an intensive pre- season training program modifies the inflammatory status in professional soccer players and if this inflammatory profile may be associated with the physical state. We compared plasma protein biomarkers, using proteomics, and the physiological state and cardiac function in 12 professional soccer players and 9 recreational soccer players. Reduced cardiac low frequency [LF] after the pre- season training program previous competition with respect to recreational soccer players was found. No differences were found in cardiac high frequency, cardiac high frequency/low frequency ratio, tension index and oxygen volume consumption. Alpha-1-antitrypsin isotype-3, fibrinogen-gamma isotypes-1, 2 and 3 and vitamin-D-binding protein isotype-1 were reduced in professionals players compared with those in recreational players. However, an increased content of alpha-1-antitrypsin isotype-6 and alpha-1-antichymotrypsin 1 and 4 were found in professional soccer players. Spearman´s analysis showed a positive correlation between LF and fibrinogen-gamma chain isotype 3; but LF was negatively correlated with alpha-antichymotrypsin isotype 4. Professional soccer players submitted to an intensive training showed differences in the content of plasma proteins associated with inflammatory/oxidative stress and thrombosis with respect to recreational soccer players. Proteomics analysis in combination with the analysis of cardiac function assessment may be useful to know more in depth molecular processes associated with sport and intensive exercise.

  10. Physical Attributes and NFL Combine Performance Tests Between Italian National League and American Football Players: A Comparative Study.

    Science.gov (United States)

    Vitale, Jacopo A; Caumo, Andrea; Roveda, Eliana; Montaruli, Angela; La Torre, Antonio; Battaglini, Claudio L; Carandente, Franca

    2016-10-01

    Vitale, JA, Caumo, A, Roveda, E, Montaruli, A, La Torre, A, Battaglini, CL, and Carandente, F. Physical attributes and NFL Combine performance tests between Italian National League and American football players: a comparative study. J Strength Cond Res 30(10): 2802-2808, 2016-The purpose of this study was to examine anthropometric measurements and the results of a battery of performance tests administered during the National Football League (NFL) Combine between American football players who were declared eligible to participate in the NFL Combine and football players of a top Italian team (Rhinos Milan). Participants (N = 50) were categorized by position into 1 of 3 groups based on playing position: skill players (SP) included wide receivers, cornerbacks, free safeties, strong safeties, and running backs; big skill players (BSP) consisted of fullbacks, linebackers, tight ends, and defensive ends; lineman (LM) included centers, offensive guards, offensive tackles, and defensive tackles. A 1-way analysis of variance followed by the Tukey-Kramer post hoc test was used for comparisons between Italian players by playing position. Ninety-five percent CIs were used for comparisons between American and Italian football for the NFL Combine performance tests. Significant differences for all the variables between the 3 playing categories were observed among the Italian players; LM had higher anthropometric and body composition values than SP (p football players presented significantly higher anthropometric values and test performance scores when compared with Italian players. Administrators of professional football teams in Italy need to improve the player's physical attributes, so the gap that currently exists between American and Italian players can be reduced, which could significantly improve the quality of American football in Italy.

  11. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  12. Injuries in racket sports among Slovenian players.

    Science.gov (United States)

    Kondric, Miran; Matković, Branka R; Furjan-Mandić, Gordana; Hadzić, Vedran; Dervisević, Edvin

    2011-06-01

    On the sample of 83 top Slovenian athletes we have studied the frequency of injuries among table tennis, tennis and badminton players, types of injuries and severity of injuries--the latter based on data of players absences from training and/or competition processes. The most liable parts to injuries are shoulder girdle (17.27%), spine (16.55%) and ankle (15.83%), while foot (10.07%) and wrist (12.23%) are slightly less liable to injuries. The most frequent injuries in racket sports pertain to muscle tissues. According to this data, the majority of injuries occur halfway through a training session or a competition event, mostly during a competition season. The injuries primarily pertain to muscle tissues; these are followed by joint and tendon injuries. There are no differences between male and female players. Compared to other racket sports players, table tennis players suffer from fewer injuries.

  13. Decreased Nerve Conduction Velocity in Football Players

    Directory of Open Access Journals (Sweden)

    Daryoush Didehdar

    2014-06-01

    Full Text Available Background: Lower limbs nerves are exposed to mechanical injuries in the football players and the purpose of this study is to evaluate the influence of football on the lower leg nerves. Materials and Methods: Nerve conduction studies were done on 35 male college students (20 football players, 15 non active during 2006 to 2007 in the Shiraz rehabilitation faculty. Standard nerve conduction techniques using to evaluate dominant and non dominant lower limb nerves. Results: The motor latency of deep peroneal and tibial nerves of dominant leg of football players and sensory latency of superficial peroneal, tibial and compound nerve action potential of tibial nerve of both leg in football players were significantly prolonged (p<0.05. Motor and sensory nerve conduction velocity of tibial and common peroneal in football players were significant delayed (p<0.05. Conclusion: It is concluded that football is sport with high contact and it causes sub-clinical neuropathies due to nerve entrapment.

  14. Outcomes of microfracture in professional basketball players.

    Science.gov (United States)

    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 0.05) and 3.0 min (P NBA game. On return to competition player performance and minutes per game are diminished.

  15. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.

    Science.gov (United States)

    Stamm, Julie M; Koerte, Inga K; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P; Baugh, Christine M; Giwerc, Michelle Y; Zhu, Anni; Coleman, Michael J; Bouix, Sylvain; Fritts, Nathan G; Martin, Brett M; Chaisson, Christine; McClean, Michael D; Lin, Alexander P; Cantu, Robert C; Tripodis, Yorghos; Stern, Robert A; Shenton, Martha E

    2015-11-15

    Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

  16. The Relative Age Effect in Spanish Female Soccer Players. Influence of the Competitive Level and a Playing Position

    Directory of Open Access Journals (Sweden)

    Sedano Silvia

    2015-06-01

    Full Text Available The purposes of the study were to examine relative age effects (RAEs in Spanish female soccer and to identify the influence of a playing position. The sample comprised all female players (n=4035 of five different competitive levels in the 2010-2013 seasons: First, Second and Third divisions (n=936, n=1711 and n=870, respectively, and National and Regional (n=232 and n=286, respectively teams were included. Differences between the observed and expected birth-date distributions were tested based on data from the general Spanish population, using the chi-square statistic followed up by calculating odds ratios and 95% confidence intervals. Results revealed that the birth-date distributions of almost all groups of football players showed an overrepresentation of players born in the first quartile. Only in the lowest level was age distribution not significantly different from that of the general population. Moreover, the RAE risk progressively increased with a higher level of involvement. It was also observed that at some playing positions the birth-date distributions were significantly biased. That was the case for goalkeepers and defenders. It could be concluded that in the current structure of Spanish female soccer there is a relative age effect, probably due to the early processes of talent identification.

  17. The Relative Age Effect in Spanish Female Soccer Players. Influence of the Competitive Level and a Playing Position

    Science.gov (United States)

    Sedano, Silvia; Vaeyens, Roel; Redondo, Juan Carlos

    2015-01-01

    The purposes of the study were to examine relative age effects (RAEs) in Spanish female soccer and to identify the influence of a playing position. The sample comprised all female players (n=4035) of five different competitive levels in the 2010–2013 seasons: First, Second and Third divisions (n=936, n=1711 and n=870, respectively), and National and Regional (n=232 and n=286, respectively) teams were included. Differences between the observed and expected birth-date distributions were tested based on data from the general Spanish population, using the chi-square statistic followed up by calculating odds ratios and 95% confidence intervals. Results revealed that the birth-date distributions of almost all groups of football players showed an overrepresentation of players born in the first quartile. Only in the lowest level was age distribution not significantly different from that of the general population. Moreover, the RAE risk progressively increased with a higher level of involvement. It was also observed that at some playing positions the birth-date distributions were significantly biased. That was the case for goalkeepers and defenders. It could be concluded that in the current structure of Spanish female soccer there is a relative age effect, probably due to the early processes of talent identification. PMID:26240656

  18. The Distribution Pattern of Skinfold Thickness in College Female Judo Players

    OpenAIRE

    長谷川, 優; 竹内, 外夫; 湯浅, 景元; Masaru, HASEGAWA; Hokao, TAKEUCHI; Kagemoto, YUASA

    1994-01-01

    A study was carried out to investigate the distribution pattern of the skinfold thickness in female college judo players. A total of 17 judo players were divided into two groups : -56kg and +56kg groups. These players were compared to non-trained female subjects of similar age. Skinfold thickenesses were measured on 30 body sites with using B-mode ultrasonic device employing a 5MHz tansducer. The +56kg group showed significantly thicker skinfold than-56kg group at the sites of above and under...

  19. Acute inguinal pain associated with iliopectineal bursitis in four professional soccer players.

    Science.gov (United States)

    Brunot, S; Dubeau, S; Laumonier, H; Creusé, A; Delmeule, T; Reboul, G; Das Neves, D; Bouin, H

    2013-01-01

    Four professional soccer players were investigated for acute or subacute pain in the inguinal region. Clinical tests were negative for an inguinal hernia or adductor tendinitis. Resisted hip flexion caused pain. MRI in these four patients showed the onset of iliopectineal bursitis, with signal abnormalities predominantly at the periphery of the psoas tendon in contact with the iliopectineal eminence. Ultrasound-guided steroid injection allowed the two players injected to continue their sporting activity. The two other players were treated by 3 and 7 days rest and oral anti-inflammatory treatment. Copyright © 2012 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  20. Asymmetry in volume between dominant and nondominant upper limbs in young tennis players.

    Science.gov (United States)

    Rogowski, Isabelle; Ducher, Gaële; Brosseau, Olivier; Hautier, Christophe

    2008-08-01

    This study aimed at demonstrating the asymmetry in volume between the dominant and nondominant upper limbs in tennis players, controlled for maturity status. Upper limb volumes on both sides were calculated in 72 tennis players and 84 control subjects, using the truncated cone method. The participants' maturity status was determined using the predicted age at peak height velocity (PHV). The results showed significant larger side-to-side asymmetry in volume in tennis groups than in control groups. These findings suggested that, even before PHV, specific-sport adaptations occurred in the dominant upper limb in tennis players.

  1. The Effect of Body Mass on Eccentric Knee-Flexor Strength Assessed With an Instrumented Nordic Hamstring Device (Nordbord) in Football Players.

    Science.gov (United States)

    Buchheit, Martin; Cholley, Yannick; Nagel, Mark; Poulos, Nicholas

    2016-09-01

    To examine the effect of body mass (BM) on eccentric knee-flexor strength using the Nordbord and offer simple guidelines to control for the effect of BM on knee-flexor strength. Data from 81 soccer players (U17, U19, U21, senior 4th French division, and professionals) and 41 Australian Football League (AFL) players were used for analysis. They all performed 1 set of 3 maximal repetitions of the bilateral Nordic hamstring exercise, with the greatest strength measure used for analysis. The main regression equation obtained from the overall sample was used to predict eccentric knee-flexor strength from a given BM (moderate TEE, 22%). Individual deviations from the BM-predicted score were used as a BM-free index of eccentric knee- flexor strength. There was a large (r = .55, 90% confidence limits .42;.64) correlation between eccentric knee-flexor strength and BM. Heavier and older players (professionals, 4th French division, and AFL) outperformed their lighter and younger (U17-U21) counterparts, with the soccer professionals presenting the highest absolute strength. Professional soccer players were the only ones to show strength values likely slightly greater than those expected for their BM. Eccentric knee-flexor strength, as assessed with the Nordbord, is largely BM-dependent. To control for this effect, practitioners may compare actual test performances with the expected strength for a given BM, using the following predictive equation: Eccentric strength (N) = 4 × BM (kg) + 26.1. Professional soccer players with specific knee-flexor-training history and enhanced neuromuscular performance may show higher than expected values.

  2. Nutrient intake of highly competitive male and female collegiate karate players.

    Science.gov (United States)

    Teshima, Kaori; Imamura, Hiroyuki; Yoshimura, Yoshitaka; Nishimura, Seiji; Miyamoto, Noriko; Yamauchi, Yoichi; Hori, Hitoshi; Moriwaki, Chinatsu; Shirota, Tomoko

    2002-07-01

    Nutrient intake of 29 male (M Group) and 16 female (F Group) highly competitive collegiate karate players were compared. The results were also compared with the daily energy expenditure (DEE), Japanese recommended dietary allowances (RDAs) or adequate dietary intakes (ADIs). Dietary information was collected using a 3-weekday diet record. Although the M Group showed significantly higher mean %RDAs or %ADIs in iron, vitamin B1, phosphorus, magnesium, and sodium than the F Group, many of the mean %RDAs or %ADIs were below RDAs or ADIs in both groups. The subjects who skipped meals tended to show lower mean %DEE, Japanese %RDAs or %ADIs in minerals and vitamins than the subjects who did not skip in both M and F Groups. The consumption of green and other vegetables and milk and dairy products in both M and F Groups were low. It is concluded that the male and female highly competitive karate players studied in the present study may be at risk of sub-optimal nutrient intake, which increases the potential for nutrient deficiency. The subjects were advised not to skip meals, and to consume a balanced high-carbohydrate, moderate-protein, low-fat diet with increasing green and other vegetables and milk and dairy products to increase mineral, vitamin and dietary fiber intakes.

  3. Differential postural control and sensory organization in young tennis players and taekwondo practitioners.

    Science.gov (United States)

    Fong, Shirley S M; Chung, Joanne W Y; Ng, Shamay S M; Ma, Ada W W; Chow, Lina P Y; Tsang, William W N

    2014-04-01

    This study compared the sensory organization and standing balance of adolescent tennis players, taekwondo (TKD) practitioners, and healthy control participants. Sixty participants including 12 tennis players, 21 TKD practitioners, and 27 healthy control participants were tested. All of the participants underwent the Sensory Organization Test (SOT) and the Unilateral Stance Test (UST) on a Smart Equitest system. Results revealed that tennis players had higher SOT visual ratios than the control participants (p = .005), and TKD practitioners swayed more slowly in the UST than the control participants (p = .039). No differences (p > .05) were found in the composite score, somatosensory ratio, or vestibular ratio between the groups. Tennis players swayed less when they relied more on visual input to maintain balance, whereas TKD practitioners were more stable when standing on one leg. Parents may consider these sports as recreational activities for their children to develop specific balance abilities.

  4. Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population.

    Science.gov (United States)

    Amen, Daniel G; Willeumier, Kristen; Omalu, Bennet; Newberg, Andrew; Raghavendra, Cauligi; Raji, Cyrus A

    2016-04-25

    National Football League (NFL) players are exposed to multiple head collisions during their careers. Increasing awareness of the adverse long-term effects of repetitive head trauma has raised substantial concern among players, medical professionals, and the general public. To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls. A cohort of retired and current NFL players (n = 161) were recruited in a longitudinal study starting in 2009 with ongoing interval follow up. A healthy control group (n = 124) was separately recruited for comparison. Assessments included medical examinations, neuropsychological tests, and perfusion neuroimaging with single photon emission computed tomography (SPECT). Perfusion estimates of each scan were quantified using a standard atlas. We hypothesized that hypoperfusion particularly in the orbital frontal, anterior cingulate, anterior temporal, hippocampal, amygdala, insular, caudate, superior/mid occipital, and cerebellar sub-regions alone would reliably separate controls from NFL players. Cerebral perfusion differences were calculated using a one-way ANOVA and diagnostic separation was determined with discriminant and automatic linear regression predictive models. NFL players showed lower cerebral perfusion on average (p NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (95% CI 95-99). Automatic linear modeling achieved similar results. Inclusion of age and clinical co-morbidities did not improve diagnostic classification. Specific brain regions commonly damaged in traumatic brain injury show abnormally low perfusion on SPECT in professional NFL players. These same regions alone can distinguish this group from healthy subjects with high diagnostic accuracy. This study carries implications for the neurological safety of NFL players.

  5. Real-Time Game Adaptation for Optimizing Player Satisfaction

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John

    2009-01-01

    preferences for augmented-reality game players. An adaptive mechanism then adjusts controllable game parameters in real time in order to improve the entertainment value of the game for the player. The basic approach presented here applies gradient ascent to the user model to suggest the direction of parameter...... adjustment that leads toward games of higher entertainment value. A simple rule set exploits the derivative information to adjust specific game parameters to augment the entertainment value. Those adjustments take place frequently during the game with interadjustment intervals that maintain the user model......'s accuracy. Performance of the adaptation mechanism is evaluated using a game survey experiment. Results indicate the efficacy and robustness of the mechanism in adapting the game according to a user's individual playing features and enhancing the gameplay experience. The limitations and the use...

  6. Concussion history and reporting rates in elite Irish rugby union players.

    Science.gov (United States)

    Fraas, Michael R; Coughlan, Garrett F; Hart, Emily C; McCarthy, Conor

    2014-08-01

    To determine the self-reported, seasonal rates of concussion and the reporting practices among Irish rugby union players. Descriptive epidemiology study. The study was conducted at the training grounds of four professional Irish rugby union clubs. One hundred seventy-two players (24.97 ± 4.11 years of age, 13.49 ± 5.79 years playing experience) gave consent to participate. Number of concussions reported during the 2010-2011 season, reasons for not reporting, and positions of concussed players. Forty-five percent of players reported at least one concussion during the 2010-2011 season, but only 46.6% of these presented to medical staff. The reasons for not reporting their concussions included, not thinking the injury was serious enough, and not wanting to be removed from the game. The relative proportion of concussions was higher for backs than forwards; however, the severity of injury was greater for forwards. Scrum-halves (12.0%) and flankers (10.9%) accounted for the majority of concussions reported. The self-reported rate of concussion in elite rugby union players in Ireland is higher than reported in other countries or other sports. Many concussions remain unreported and, therefore, unmanaged. However, recent changes in concussion management guidelines by the International Rugby Board may impact future reporting practices of players. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Incidence of Stingers in Young Rugby Players.

    Science.gov (United States)

    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

  8. Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

    Directory of Open Access Journals (Sweden)

    Daniele Conte

    2017-01-01

    Full Text Available This study aimed to assess the basketball ball-drills workload analyzing: (1 the effect of varying the number of players involved on physiological and technical demands; (2 the temporal changes in players’ responses across bouts; and (3 the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1 completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax and ratings of perceived exertion (RPE were collected. Technical actions (TAs (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers were calculated through notational analysis. Players’ genitalia development (GD and pubic hair (PH growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018, RPE (p = 0.042, dribbles (p = 0.007, shots (p = 0.003, and rebounds (p = 0.006 in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005 and number of passes (p = 0.020 between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age.

  9. Feasibility and efficacy of progressive electrostimulation strength training for competitive tennis players.

    Science.gov (United States)

    Maffiuletti, Nicola A; Bramanti, Jacopo; Jubeau, Marc; Bizzini, Mario; Deley, Gaëlle; Cometti, Gilles

    2009-03-01

    The purpose of this preliminary study was to show the feasibility of electrostimulation (ES) strength exercise incorporated into tennis sessions during the preparatory season of competitive players, and its impact on anaerobic performance. Twelve tennis players (5 men, 7 women) completed 9 sessions of quadriceps ES (duration: 16 minutes; frequency: 85 Hz; on-off ratio: 5.25-25 seconds) during 3 weeks. The ES sessions were integrated into tennis training sessions. Subjects were baseline tested and retested 1 (week 4), 2 (week 5), 3 (week 6), and 4 weeks (week 7) after the ES training program for maximal quadriceps strength, vertical jump height, and shuttle sprint time. Participants were able to progressively increase ES current amplitude and evoked force throughout the 9 training sessions, with an optimal treatment compliance of 100%. Maximal quadriceps strength significantly increased during the entire duration of the experiment (p < 0.001). Countermovement jump height at week 5 (+5.3%) and week 6 (+6.4%) was significantly higher than at baseline (p < 0.05). In addition, 2 x 10-m sprint time at week 6 was significantly shorter (-3.3%; p = 0.004) compared with pretraining. The 3-week ES strength training program was successfully incorporated into preseason tennis training with a linear progression in all training parameters. Throughout the study period, a delayed enhancement of anaerobic power and stretch-shortening cycle performance was observed. Progressive ES strength training may be safely included in the early tennis season and can lead to improvements in the anaerobic performance of men and women players.

  10. Left ventricular function in professional football players evaluated by tissue Doppler imaging and strain imaging.

    Science.gov (United States)

    Tümüklü, Mustafa Murat; Etikan, Ilker; Cinar, Cahide Soydaş

    2008-01-01

    Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler Imaging(TDI) and Strain Myocardial Imaging(SI) are new tools in the evaluation systolic and diastolic myocardial function. We sought to compare TDI and SI findings in professional football players and age adjusted sedentary controls to assess the effect of regular athletic training on myocardial function. Transthoracic echocardiography, M-mode, 2-D measurements, Doppler derived mitral-tricuspid annular velocities, reconstructed spectral pulsed wave tissue Doppler velocities, strain and strain rate imaging of seven different myocardial regions were obtained from 24 professional football players and age, sex and weight adjusted 20 controls. Age, body surface area, blood pressure and heart rate were comparable between 2 groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal TDI peak early diastolic(e) velocity(0.22 +/- 0.04 vs. 0.19 +/- 0.04 m/s, P velocity (0.19 +/- 0.03 vs. 0.16 +/- 0.02 m/s, P football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function which can be detected by TDI. Strain rate imaging may be a new tool to define subtle change in systolic left ventricular function in "athletes heart" which cannot be determined in standard echocardiographic parameters.

  11. Assessment of nutrition, supplementation and body composition parameters on the example of professional volleyball players.

    Science.gov (United States)

    Zapolska, Joanna; Witczak, Katarzyna; Mańczuk, Angelika; Ostrowska, Lucyna

    2014-01-01

    Volleyball is a team game belonging to a group of sports disciplines that involve indirect fighting. Adequate energy coverage in athletes is a crucial issue. It depends primarily on the type, intensity and duration of physical activity related to the sports discipline practiced and to the training cycle duration. The average energy requirement in sportsmen is 50% higher than that of adults. The aim of the study was to characterize the mode of nutrition, including dietary supplements and to assess somatic indices in female volleyball players of the AZS Bialystok team. The study involved 17 women. Research tools included a questionnaire consisting of 24-hour recall, a questionnaire survey concerning supplement intake and body composition analysis performed using a bioimpedance analyzer InBody 220. Data analysis indicates that the anthropometric characteristics and body composition of the AZS Bialystok players meet the recommendations associated with the somatic features in volleyball. Daily diet of the volleyball players were of low-energy with regard to the recommendations for physically active people, with very low supply of carbohydrates and dietary fiber, excessive proportion of saturated fatty acids and dietary cholesterol, and too low content of monounsaturated and polyunsaturated fatty acids. Supply of vitamins and minerals was found to be alarmingly low, especially of iron and calcium; diet supplementation was insufficient. No significant abnormalities were noted in body composition of the study athletes. However, they are recommended to increase muscle mass and slightly reduce body fat. Results of diet evaluation show the need for education in the field of nutrition and the necessity of further research into dietary habits among sportsmen.

  12. Anthropometric, Physical, and Age Differences by the Player Position and the Performance Level in Volleyball

    Directory of Open Access Journals (Sweden)

    Palao José M.

    2014-12-01

    Full Text Available The purpose of this paper was to study the ranges in height, weight, age, spike reach, and block reach of volleyball players in relation to the player position and the level of their respective teams in peak performance. The analysed sample included 1454 male and 1452 female players who participated in the volleyball competitions of the Olympic Games and World Championships in the 2000-2012 period. A descriptive, correlational, and longitudinal design was used. The variables studied were: the player position, body height, weight, body mass index, spike reach, block reach, age, and team level. The results show differences between body height, spike and block reaches, and the age of the players by their position. These differences are related to the needs of the different positions with regard to the actions they execute. Middle-blockers, outside-hitters, and opposites have the characteristics that are most suitable for blocking and spiking, and the setters and liberos appear to have characteristics conducive to setting and receiving as well as digging, respectively. The differences found in the studied variables with regard to the playing position are related to players' needs regarding the actions they perform. Player´s age was a variable that differentiated first teams at this level of competition for males, and physical capacities (body height, weight, spike reach, and block reach were variables that differentiated first teams at this level of competition for females.

  13. Comparison of posture among adolescent male volleyball players and non-athletes

    Science.gov (United States)

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

  14. A PILOT STUDY COMPARING TWO FIELD TESTS WITH THE TREADMILL RUN TEST IN SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Abdul Rashid Aziz

    2005-06-01

    Full Text Available This study compares the performances obtained during soccer-specific field tests of the 20 m multistage shuttle run test (MST and the Yo-Yo intermittent endurance test (YIET, with the measured maximal oxygen uptake (VO2max obtained in both field tests as well as that obtained in the traditional test of running to exhaustion on a treadmill (TRT, in young trained soccer players. Twenty-one National-level youth players performed, in random order, the MST and YIET to determine the relationship between the two field tests. From these, eight randomly chosen players performed their field tests as well as a TRT, equipped with an ambulatory gas exchange measurement device. Pearson correlation coefficient analysis showed that the players' performance (i.e. distance covered in the MST and YIET was correlated (r = 0.65, p 0.05. In contrast, significant correlations were observed between the players' performance in the MST with the measured VO2max obtained in the same MST and in the YIET (both p < 0.05; and attained almost statistical significance with the measured VO2max in the TRT (p = 0.06. The lack of association between distances covered in the YIET with all the measured VO2max values suggest that measured VO2max per se may not be suitable to characterize soccer players' intermittent endurance performance. In comparison with the MST, the YIET may be a more favourable field-based assessment of soccer player's endurance performance

  15. Comparison of posture among adolescent male volleyball players and non-athlete

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-10-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  16. Comparison of posture among adolescent male volleyball players and non-athletes

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-11-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  17. Effect of sport training on forearm bone sites in female handball and soccer players.

    Science.gov (United States)

    Boshnjaku, Arben; Dimauro, Ivan; Krasniqi, Ermira; Grazioli, Elisa; Tschan, Harald; Migliaccio, Silvia; DI Luigi, Luigi; Caporossi, Daniela

    2016-12-01

    The objective of this study was to evaluate the bone mineral density (BMD) and Z-score of a skeletal region, considered as weight-bearing site in trained handball players (HP), but as non-weight-bearing site in trained soccer players (SP). The bone health status of the same site was also analyzed in an untrained group (CG). BMD and Z-score at distal forearm regions (dominant, D; non-dominant, ND) were evaluated in 30 female HP and in 30 female SP, who have been training for 7.7±3.8 years, 17 hours per week, as well as in 30 females CG. Playing handball was associated with higher BMD of the skeleton at both measured sites than in CG. Also in comparison with SP, HPs' arms showed a significant increase in BMD. On the other hand, female SP have been reported to exhibit an enhanced ND arm BMD compared with controls. The benefits of exercise appeared to be significantly improved only in SP sub-group who started sport activity before or at menarche. These athletes showed at ND forearm a BMD 4% greater than those SP who started later, reaching a BMD of 11.6% higher than CG, a value similar to the corresponding in HP sub-group. Moreover, their D arm BMD was 7.1% higher compared with CG. This study indicates that, compared with non-trained subjects, long-term high-impact sport participation is associated with an higher bone health state, especially if the playing careers were started before or at menarche. This effect was observed at level of both forearms in HP, which are considered as weight-bearing sites for this discipline but also on the same skeletal regions of SP, which are not directly loaded by sport-related regular training.

  18. Quantifying the high-speed running and sprinting profiles of elite female soccer players during competitive matches using an Optical Player Tracking System.

    Science.gov (United States)

    Mara, Jocelyn K; Thompson, Kevin G; Pumpa, Kate L; Morgan, Stuart

    2016-09-06

    The aim of this study was to determine the high-speed running and sprinting profiles of elite female soccer players during competitive matches using a new Optical Player Tracking System. Eight stationary video cameras were positioned at vantage points surrounding the soccer field so that when each camera view was combined the entire field could be viewed simultaneously. Following each match, an optical player tracking system detected the coordinates (x,y) of each player for every video frame. Algorithms applied to the x and y coordinates were used to determine activity variables for twelve elite female players across seven competitive matches. Players covered 9,220-10,581 m of total distance, 1,772-2,917 m of high-speed running (3.4-5.3 m·s) distance and 417-850 m of sprinting (>5.4 m·s) distance, with variations between positional groups (p sprints (71-78 %) were performed over distances less than 10 m. Mean time between high-speed runs (13.9 s ± 4.4) and sprints (86.5 s ± 38.0) varied according to playing position (p drills, and shows that coaches should take an individualised approach to training load monitoring according to position.

  19. Examining Player Anger in World of Warcraft

    Science.gov (United States)

    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.

  20. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  1. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In order to improve Compact Disc Players playability regarding playing Compact Discs with surface faults, like scratches and fingerprints etc, the attention has been put on fault tolerant control schemes. Almost every of those methods are based on fault detection. The standard approach is to use...... a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  2. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved by realizing the fact that players’ perception of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and culture background....... While one player might find the game immersive, others may quit playing as a result of encountering a seemingly insoluble problem. One promising avenue towards optimizing the gameplay experience for individual game players is to tailor player experience in real-time via automatic game content generation......-driven content generation....

  3. Cumulative Incidence of Osteochondritis Dissecans of the Capitellum in Child and Adolescent Baseball Players

    Science.gov (United States)

    Iwame, Toshiyuki; Matsuura, Tetsuya; Suzue, Naoto; Sairyo, Koichi

    2016-01-01

    playing baseball, playing period of baseball, number of training hours per week, and history of elbow pain. Data were analyzed by multivariate logistic regression models and presented as odds ratio (OR) and profile likelihood 95% confidence interval (CI) values. Results: The mean age that players were introduced to baseball was 6.6 ±1.1 years; the mean duration of play baseball was 2.7 ±1.1 years; and the proportion of players with elbow pain when throwing was 24.1%. There were 138 (10.8%) pitchers, 114 (8.9%) catchers, 524 (41.2%) infielders, and 499 (39.1%) outfielders. The initial ultrasonographic screening revealed an irregularity of the subchondral bone in 33 players (2.6%). Of the 33 players, all the players agreed to undergo radiography. Of them, 23 players were confirmed OCD. These results showed that cumulative incidence of OCD was 1.8%. Univariate analysis showed that OCD occurrence was significantly associated with age of 11-12 years (pbaseball, number of training hours per week, playing position, and history of elbow pain were not significantly associated with OCD. Multivariate analysis showed that age of 11-12 years (OR, 3.96; 95% CI, 1.10-18.97) was risk factors significantly associated with OCD. Experimental year was not significantly associated with OCD occurrence. Conclusion: It is expected that 1.8% of youth baseball players have OCD each year. The age of 11 and 12, increased training hours per week are risk factors for OCD.

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

    Science.gov (United States)

    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.

  5. CORRELATING THE PURDUE SPATIAL VISUALIZATION TEST WITH THE WONDERLIC PERSONNEL TEST FOR AMERICAN FOOTBALL PLAYERS

    OpenAIRE

    Sukumar, Karthik

    2013-01-01

    This research study aims to find the relationship between the scores for the Purdue Spatial Visualization test (PSVT) and the Wonderlic Personnel test (WPT) for American collegiate football players. Fifty-five collegiate football players took part in the study by attempting the PSVT and the WPT. The scores on these tests were compared to find if there existed a correlation between the scores on both these tests. The results showed that the scores on both these tests had a significant correlat...

  6. Nutrient intake, serum lipids and iron status of colligiate rugby players

    Directory of Open Access Journals (Sweden)

    Imamura Hiroyuki

    2013-02-01

    Full Text Available Abstract Background There are two main playing positions in rugby (backs and forwards, which demonstrate different exercise patterns, roles, and physical characteristics. The purpose of this study was: 1 to collect baseline data on nutrient intake in order to advise the athletes about nutrition practices that might enhance performance, and 2 to compare serum lipids, lipoproteins, apolipoproteins (apo, lecithin:cholesterol acyltransferase (LCAT activity, and iron status of forwards and backs. Methods The sporting group was divided into 18 forwards and 16 backs and were compared with 26 sedentary controls. Dietary information was obtained with a food frequency questionnaire. Results There were significant differences among the three groups. The forwards had the highest body weight, body mass index, percentage of body fat (calculated by sum of four skinfold thicknesses, as well as the highest lean body mass, followed by the backs and the control group. The mean carbohydrate intake was marginal and protein intake was lower than the respective recommended targets in all three groups. The mean intakes of calcium, magnesium, and vitamins A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances or adequate dietary intakes for the rugby players. The forwards had significantly lower high-density lipoprotein cholesterol (HDL-C and HDL2-C than the backs and had significantly higher apo B and LCAT activity than the controls. The backs showed significantly higher HDL-C, HDL3-C, low-density lipoprotein cholesterol, and apo A-I, and LCAT activity than the controls. Four forwards (22%, five backs (31%, and three controls (12% had hemolysis. None of the rugby players had anemia or iron depletion. Conclusion The findings of our study indicate that as the athletes increased their carbohydrate and protein intake, their performance and lean body mass increased. Further, to increase mineral and vitamin intakes, we recommended athletes

  7. Examination of mechanisms underlying enhanced memory performance in action video game players: a pilot study.

    Science.gov (United States)

    Li, Xianchun; Cheng, Xiaojun; Li, Jiaying; Pan, Yafeng; Hu, Yi; Ku, Yixuan

    2015-01-01

    Previous studies have shown enhanced memory performance resulting from extensive action video game playing. The mechanisms underlying the cognitive benefit were investigated in the current study. We presented two types of retro-cues, with variable intervals to memory array (Task 1) or test array (Task 2), during the retention interval in a change detection task. In Task 1, action video game players demonstrated steady performance while non-action video game players showed decreased performance as cues occurred later, indicating their performance difference increased as the cue-to-memory-array intervals became longer. In Task 2, both participant groups increased their performance at similar rates as cues presented later, implying the performance difference in two groups were irrespective of the test-array-to-cue intervals. These findings suggested that memory benefit from game plays is not attributable to the higher ability of overcoming interference from the test array, but to the interactions between the two processes of protection from decay and resistance from interference, or from alternative hypotheses. Implications for future studies were discussed.

  8. Imaging of Glial Cell Activation and White Matter Integrity in Brains of Active and Recently Retired National Football League Players.

    Science.gov (United States)

    Coughlin, Jennifer M; Wang, Yuchuan; Minn, Il; Bienko, Nicholas; Ambinder, Emily B; Xu, Xin; Peters, Matthew E; Dougherty, John W; Vranesic, Melin; Koo, Soo Min; Ahn, Hye-Hyun; Lee, Merton; Cottrell, Chris; Sair, Haris I; Sawa, Akira; Munro, Cynthia A; Nowinski, Christopher J; Dannals, Robert F; Lyketsos, Constantine G; Kassiou, Michael; Smith, Gwenn; Caffo, Brian; Mori, Susumu; Guilarte, Tomas R; Pomper, Martin G

    2017-01-01

    Microglia, the resident immune cells of the central nervous system, play an important role in the brain's response to injury and neurodegenerative processes. It has been proposed that prolonged microglial activation occurs after single and repeated traumatic brain injury, possibly through sports-related concussive and subconcussive injuries. Limited in vivo brain imaging studies months to years after individuals experience a single moderate to severe traumatic brain injury suggest widespread persistent microglial activation, but there has been little study of persistent glial cell activity in brains of athletes with sports-related traumatic brain injury. To measure translocator protein 18 kDa (TSPO), a marker of activated glial cell response, in a cohort of National Football League (NFL) players and control participants, and to report measures of white matter integrity. This cross-sectional, case-control study included young active (n = 4) or former (n = 10) NFL players recruited from across the United States, and 16 age-, sex-, highest educational level-, and body mass index-matched control participants. This study was conducted at an academic research institution in Baltimore, Maryland, from January 29, 2015, to February 18, 2016. Positron emission tomography-based regional measures of TSPO using [11C]DPA-713, diffusion tensor imaging measures of regional white matter integrity, regional volumes on structural magnetic resonance imaging, and neuropsychological performance. The mean (SD) ages of the 14 NFL participants and 16 control participants were 31.3 (6.1) years and 27.6 (4.9) years, respectively. Players reported a mean (SD) of 7.0 (6.4) years (range, 1-21 years) since the last self-reported concussion. Using [11C]DPA-713 positron emission tomographic data from 12 active or former NFL players and 11 matched control participants, the NFL players showed higher total distribution volume in 8 of the 12 brain regions examined (P brain volumes or in

  9. Overload and neovascularization of shoulder tendons in volleyball players

    Directory of Open Access Journals (Sweden)

    Notarnicola Angela

    2012-08-01

    Full Text Available Abstract Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7% than middle hitters (53.7% (p = 0.01, opposite hitters (55.5% (p = 0.02 and libero players (54.4% (p = 0.008, whereas there were no differences in setters (56.2% (p > 0.05. Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.

  10. Overload and neovascularization of shoulder tendons in volleyball players

    Science.gov (United States)

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  11. Shoulder pain among high-level volleyball players and preseason features.

    Science.gov (United States)

    Forthomme, Benedicte; Wieczorek, Valerie; Frisch, Anne; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2013-10-01

    The main goal of this prospective study was to identify the most significant intrinsic risk factors for shoulder pain by measuring strength developed by shoulder rotators and by carrying out various morphostatic assessments. Sixty-six players (mean ± SD age = 24 ± 5 yr) were recruited from nine volleyball teams from the first and second divisions (34 men and 32 women) to participate in the study. Before the start of the volleyball season, all the participants completed a preseason questionnaire and underwent both a bilateral isokinetic evaluation of the shoulders and morphostatic measurements. During the subsequent 6 months of the competition period, the players reported through a weekly questionnaire any shoulder pain experienced. During the ongoing season, 23% (15 of 66 players) of the volleyball players experienced dominant shoulder pain. Interestingly, participants who reported a history of dominant shoulder pain were found to have nine times higher risk of suffering further pain in their dominant shoulder. The eccentric maximal strength developed by the internal and external rotators was found to represent a protective factor in the volleyball players (respective odds ratios = 0.946, P = 0.01 and 0.94, P = 0.05). No risk factors were found among the shoulder morphostatic measurements. In our study, the evaluation of shoulder rotator muscle strength through isokinetic assessment, especially eccentric mode, appeared to be the most contributing parameter to identify risk factors for shoulder pain. This evaluation should allow to better identify players at risk.

  12. What is the Safest Sprint Starting Position for American Football Players?

    Directory of Open Access Journals (Sweden)

    Bruno Bonnechere, Benoit Beyer, Marcel Rooze, Jan Serge Van Sint

    2014-06-01

    Full Text Available The main objective of this study was to perform a biomechanical analysis of three different sprint start patterns to determine the safest position in term of neck injury and Sport-Related Concussion (SRC. The second objective was to collect data on the learning process effect between football players and non-players. Three different sprint initial positions adopted by football players were studied (i.e., 4-, 3- and 2-point positions. Twenty five young healthy males, including 12 football players, participated to this study. A stereophotogrammetric system (i.e., Vicon was used to record motion patterns and body segments positions. Various measurements related to head and trunk orientation, and player field-of-view were obtained (e.g., head height, trunk bending, time to reach upright position, head speed (vertical direction and body speed (horizontal direction. Learning process was found to have no influence on studied parameters. Head redress is also delayed when adopting a 4-point position leading to a reduce field-of-view during the start and increasing therefore the probability of collision. Concerning the three different positions, the 4-point position seems to be the more dangerous because leading to higher kinetic energy than the 2- and 3-point start positions. This study proposes a first biomechanical approach to understand risk/benefit balance for athletes for those three different start positions. Results suggested that the 4-point position is the most risky for football players.

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

    Science.gov (United States)

    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.

  14. The Cheerleader and the Football Player.

    Science.gov (United States)

    Patil, Malati

    2001-01-01

    Describes an activity in physics using a narrative about a bet between a cheerleader who claims she can lift a 300-pound football player off the ground. Includes questions, teaching notes, and solutions. (MM)

  15. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......-dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... domain. We employ two datasets collected from players in- teractions with two games from different genres where accu- rate models of players experience were previously built. We take the approach one step further by investigating the mod- elling mechanism ability to generalise over the two datasets. We...

  16. Video Player Keyboard Shortcuts: MedlinePlus

    Science.gov (United States)

    ... page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features on this ... enable JavaScript. MedlinePlus offers a set of accessible keyboard shortcuts for our latest Health videos on the ...

  17. Scouting the Elite, Unbreakable Football Player.

    Science.gov (United States)

    Moore, M

    1981-02-01

    Some NFL football teams see physiological profiling as a means to protect and enhance their competitive and business success. Whether football players will benefit by increased performance and fewer injuries remains to be seen.

  18. A Comparison between Australian Football League (AFL Injuries in Australian Indigenous versus Non-indigenous Players

    Directory of Open Access Journals (Sweden)

    Jessica Orchard

    2013-09-01

    Full Text Available It has previously been shown that being of aboriginal descent is a risk factor for hamstring injuries in Australian football. The aim of this study was to review the Australian Football League (AFL injury database to determine whether there were any injuries where indigenous players had different relative risks to non-indigenous players. Analysis was conducted using data from the AFL injury database, which included data from 4,492 players over 21 years (1992–2012, covering 162,683 player-matches at AFL level, 91,098 matches at lower levels and 328,181 weeks (possible matches of exposure. Compared to non-indigenous players, indigenous players had a significantly higher risk of hamstring injuries (RR 1.52, 95% CI 1.32–1.73 and calf strains (RR 1.30, 95% CI 1.00–1.69. Conversely, indigenous players had a significantly lower risk of lumbar/thoracic spine injuries (RR 0.61, 95% CI 0.41–0.91, groin strains/osteitis pubis (RR 0.75, 95% CI 0.58–0.96 and Achilles tendon injuries (RR 0.32, 95% CI 0.12–0.86. The results for the above injuries were also significant in terms of games missed. There was no difference between overall risk of injury (RR 1.03, 95% CI 0.96–1.10 or missed games (RR 1.00, 95% CI 0.97–1.04. This suggests that indigenous AFL players have the same overall number of injuries and missed games, but a slightly different injury profile.

  19. Psychological and Anthropometric Characteristics of a Hungarian Elite Football Academy’s Players

    Directory of Open Access Journals (Sweden)

    Csáki István

    2017-03-01

    Full Text Available Due to the fact that neither physical nor physiological and anthropometric differences in adolescents can serve as definitive differentiating factors in terms of choosing successful and non-successful players, coaches are encouraged to focus more on thepsychological characteristics ofyoung players. Therefore, the purpose of this study was to examine football players’ psychological skills in an elite football academy as related to age and position. Every young player at one of the most successful football academies in the country participated in this study (N=119, M=16.44±1.17. The sample was divided into four age groups according to the championship system (U16, U17, U18, U21, and into specific football positions (goalkeeper, defender, midfielder, and striker. Basedonthe results, the young academy football players had a low level ofamotivation (1.45±0.68, a high level of extrinsic motivation (5.96±0.64, and can be characterized with a higher level task (4.02±0.62 than ego orientation (3.01±0.62. All of the results for coping skills were in the mid-range (M=3.00-3.41. There were no differences in motivation, perceived motivational climate, and coping among the football players regarding their positions. However, there were significant differences among the age groups in perceived motivation and coping skills. Older players were more egooriented and had a higher level of peaking under pressure, while younger players demonstrated higher level task, ego, and coach ability levels. Football coaches need to focus less on positions and more on age differences when dealing with motivation, perceived motivation, and coping.

  20. Bone properties in child and adolescent male hockey and soccer players.

    Science.gov (United States)

    Falk, Bareket; Braid, Sarah; Moore, Michael; Yao, Matthew; Sullivan, Phil; Klentrou, Nota

    2010-07-01

    Children and adolescents who train extensively in high-impact, weight-bearing activities have enhanced bone mineral density. The purpose of this study was to evaluate bone strength, as reflected by quantitative ultrasound (QUS, Sunlight Omniscence), of child (10-12 yrs old) and adolescent (14-16 yrs old) male soccer and hockey players in comparison with age-matched controls. The groups included 30 child (CH) and 31 adolescent (AH) hockey players, 26 child (CS) and 30 adolescent (AS) soccer players, as well as 34 child (CC) and 31 adolescent (AC) healthy, non-athletic, age-matched controls. All athletes trained at an elite level year-round, with no difference in training volume between groups. Ultrasound speed of sound (SOS) was measured at the distal-radius and mid-tibia. In both age groups, hockey players were the heaviest and had the highest fat-free mass. No differences were found among groups in total energy intake, calcium or vitamin D intake. Radial and tibial SOS increased with age. Hockey players had higher radial SOS in both age groups (children: CH:3763+/-74, CS:3736+/-77, CC:3721+/-88 m/s; adolescents: AH:3809+/-105, AS:3767+/-85, AC:3760+/-94 m/s). Tibial SOS was higher in soccer players compared with controls. In spite of the higher body mass and fat-free mass in hockey players, their tibial SOS was similar to the non-athletes in both age groups. These findings support previous suggestions of sport-specific effects on bone strength. However, they need to be corroborated with longitudinal or prospective intervention studies.

  1. Movement Demands of Elite U20 International Rugby Union Players.

    Science.gov (United States)

    Cunningham, Daniel; Shearer, David A; Drawer, Scott; Eager, Robin; Taylor, Neil; Cook, Christian; Kilduff, Liam P

    2016-01-01

    The purpose of this study was to quantify movement demands of elite international age grade (U20) rugby union players during competitive tournament match play. Forty elite professional players from an U20 international performance squad were monitored using 10 Hz global positioning systems (GPS) during 15 international tournament matches during the 2014/15 and 2015/16 seasons. Data on distances, velocities, accelerations, decelerations, high metabolic load (HML) distance and efforts, and number of sprints were derived. Data files from players who played over 60 min (n = 161) were separated firstly into Forwards and Backs, and more specifically into six positional groups; FR--Front Row (prop & hooker), SR--Second Row, BR--Back Row (Flankers & No.8), HB--Half Backs (scrum half & outside half), MF--Midfield (centres), B3--Back Three (wings & full back) for match analysis. Analysis revealed significant differences between forwards and backs positions. Backs scored higher on all variables measured with the exception of number of moderate accelerations, decelerations (no difference). The centres covered the greatest total distance with the front row covering the least (6.51 ± 0.71 vs 4.97 ± 0.75 km, p < 0.001). The front row also covered the least high speed running (HSR) distance compared to the back three (211.6 ± 112.7 vs 728.4 ± 150.2 m, p < 0.001) who covered the most HSR distance, affirming that backs cover greater distances but forwards have greater contact loads. These findings highlight for the first time differences in the movement characteristics of elite age grade rugby union players specific to positional roles.

  2. Does the Quantum Player Always Win the Classical One?

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Jun; FANG Xi-Ming

    2004-01-01

    @@ We study quantum games in which the players have different strategic spaces. We find that the player who can use a quantum strategic space does not always possess more payoffs than the player who is restricted to apply only classical strategies. We find the condition of the classical player getting more payoffs than the quantum player. We also find that the game exhibits intriguing structures.

  3. Memory Kernel in the Expertise of Chess Players

    CERN Document Server

    Schaigorodsky, Ana L; Billoni, Orlando V

    2015-01-01

    In this work we investigate a mechanism for the emergence of long-range time correlations observed in a chronologically ordered database of chess games. We analyze a modified Yule-Simon preferential growth process proposed by Cattuto et al., which includes memory effects by means of a probabilistic kernel. According to the Hurst exponent of different constructed time series from the record of games, artificially generated databases from the model exhibit similar long-range correlations. In addition, the inter-event time frequency distribution is well reproduced by the model for realistic parameter values. In particular, we find the inter-event time distribution properties to be correlated with the expertise of the chess players through the memory kernel extension. Our work provides new information about the strategies implemented by players with different levels of expertise, showing an interesting example of how popularities and long-range correlations build together during a collective learning process.

  4. Contributions to Using IT in Education: An Educational Video Player

    Directory of Open Access Journals (Sweden)

    Ciprian CUCU

    2010-01-01

    Full Text Available Following the trends of IT use in education we propose four main principles of educational application development: anytime-anywhere access (including access for mobile devices; user-generated content; assigning users an active role inside the platform; creating a correlation between natural activities and educational activities – adding fun into the equation. With these principles in mind we developed a small Educational Player – a movie player that connects to a database to show information relevant to the events in the movie, more specific to the exact key-frame (in the movie time-line at the moment of the request. Though the application is still in a conceptual form, its possibilities make us confident in its future success either as an informal way of learning, or by using it in a formal educational context either as an e-learning tool, either as interactivity tool in a traditional classroom setting.

  5. Key Distribution based on Three Player Quantum Games

    CERN Document Server

    Toyota, Norihito

    2010-01-01

    We study a new QKD that is different from the scheme proposed by \\cite{Ramz2}, though it essentially takes our ground on three-player quantum games and Greenberg-Horne-Zeilinger triplet entangled state (GHZ state) \\cite{Gree} is used. In our scheme proposed in this article, Bob and Charlie (and Alice also) that they are players in a game get some common key or information (applied strategies and their payoffs in the game) by knowing some results of the measurement made by Alice. There is not any arbiter in our scheme, since existence of an arbiter increase the risk of wiretapping. For it is difficult to detect wiretapping, when an arbiter repeatedly sends classical information. Lastly we discuss robustness for eavesdrop. We show that though maximally entangled case and non-entangled case provided essentially equivalent way in QKD, the latter is not available in the case there are some eavesdroppers.

  6. Analysis of tactical situations of elite Turkish tennis players in terms of ‘5 game situations’

    Directory of Open Access Journals (Sweden)

    Bülent Kilit

    2011-05-01

    Full Text Available This study analyzes the tactical situations of elite Turkish tennis players in terms of “5 game situations” (serve, baseline play, return of serve, net play, playing against a net player. The data were obtained by examining the video records of 94 matches, 44 of which were between women, and 64 of which were between men tennis players, attending adults’ championship of Turkey (2008 Winter Cup. The women tennis players were of 167,30±6,12 cm, 61,22±6,23 kg and 17,70±3,44 years old, while the men were of 176,10±6,43cm, 74,46±6,83 kg and 21,34±4,77. The statistical analyses of the data were made with the help of SPSS 15.0. T test was applied in order to see whether there was a difference between the game situations’ of men and women tennis players, and (P< 0.05 was accepted as significance level.According to the study, there were significant differences (p<0.05. among of men tennis players: serve(2.stroke, aces, double fault, serve(1.stroke and serve(2.stroke winning strokes, in serve game; forehand and backhand winning and loss strokes in baseline play game; backhand winning stroke, forehand and backhand loss strokes in return of serve game; winning strokes in net player game.Women tennis players: serve (2.stroke, aces, double fault, serve (1.stroke and serve (2.stroke winning strokes, in serve game; forehand and backhand winning and loss strokes in baseline play game; forehand winning strokes, forehand and backhand loss strokes in return of serve game; forehand loss strokes in playing against a net play game: winning strokes in net player game. As a result, both female and male tennis players won the match in the serve and baseline play scores to the game situation has reached higher scores than the other game situations. Lost game scores baseline and the return of serve in game play conditions were made ​​more errors than the other game situations. All this information can be used by coaches and to establish optimum training

  7. Cortical thinning in former professional soccer players.

    Science.gov (United States)

    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.

  8. Comparing the Age Related Mood Profile of Veteran Basketball Players

    Directory of Open Access Journals (Sweden)

    Robabeh Rostami

    2016-07-01

    Full Text Available Background: Basketball, as an exciting team sport, is very popular among athletes with disabilities. Among psychological skills, mood states as an important variable have been of special interest to researchers. Objectives: The purpose of the present study was to investigate and compare profile of mood states (BRUMS of disabled former soldiers who play basketball in different age groups. Methodology: After getting permit to conduct the research, 28 disabled basketball players completed the demographic survey and the Brunel Mood Scale (BRUMS questionnaire. BRUMS consisted of 24 items in subscales of stress, anger, depression, fatigue, confusion and vigor. The one-way analysis of variance test was used for the data analysis. The significance level was set at P≤0.05. SPSS Statistics 22.0 was used for the analysis of data. Results: The results showed that mood states become less negative with age. However, scores showed a rising trend in the 35-39 age groups (mood of anger with P=0/02 fatigue with P=0/03 and confusion with P=0/04. Conclusion: It seems that examining the psychological variables in relation to age can help develop more effective strategies in physical and mental training programs for disabled players. Keywords: Mood States, Basketball Players, veteran with disabilities, Age

  9. Performance of future elite players at the NFL Scouting Combine.

    Science.gov (United States)

    Hedlund, David P

    2017-09-11

    The purpose of this study is to examine players' physical and performance measures taken at the NFL Scouting Combine and compare these to their future performance in the NFL. From 2002-2016, three types of player data (N=5,506) were collected from secondary data sources. Results players earned on various NFL Scouting Combine drills and measurements (e.g., height, weight, 40-yard dash time, vertical jump, bench press repetitions, shuttle run time, and 3-cone drill time), the position players play on the field (e.g., quarterback, running back, wide receiver, tight end, offensive line, defensive line, linebacker, and defensive back), and if players received elite performance awards (e.g., Pro Bowl and All-Pro selections) in the future were collected. After analyzing the data, the results indicate that (1) NFL quarterbacks that received All-Pro and Pro Bowl awards tend to be taller, weigh more, run faster in the 40-yard dash, jump higher, complete more bench presses, and are slower for the shuttle run and 3-cone drill; (2) All-Pro and Pro Bowl NFL running backs tend to weight more, run the 40-yard dash faster, do not jump as high, complete more bench presses, and complete the shuttle run and 3-cone drills slower; (3) NFL wide receivers that were selected for the Pro Bowl or as All-Pros tend to be taller, weigh more, run the 40-yard dash faster, have a higher vertical jump, and run the 3-cone drill faster; (4) NFL tight ends that received All-Pro and Pro Bowl awards tend to be taller, weight more, run the 40-yard dash faster, jump higher, complete more bench presses, run the shuttle run slower, and complete the 3-cone drill faster; (5) All-Pro and Pro Bowl NFL offensive linemen tend to run the 40-yard dash faster, jump higher, are able to complete more bench presses, and run both the shuttle run and 3-cone drill faster; (6) NFL defensive linemen that were selected as All-Pro and Pro Bowl players tend to be taller, weight more, run the 40-yard dash faster, jump higher

  10. Comparison of Open and Closed Stance Forehand Strokes among Intermediate Tennis Players

    Directory of Open Access Journals (Sweden)

    Tajul Arifin Muhamad

    2016-01-01

    Full Text Available Background: Nowadays tennis is becoming faster and players are able to hit powerful from virtually anywhere on the tennis court. Training programmers and effective planning will help in designing safe, effective, and productive programs designed to help optimize the tennis performance of players. Objective: This research examine the effectiveness of open and closed stance forehand strokes in terms of percentage of success, accuracy and also to investigate whether there is a relation between level of accuracy and the choice of forehand strokes used by tennis player. Method: Participants were divided into two groups, namely, male and female who learned forehand strokes for one month. The participants were tested by using a two skill test for percentage of success and level of accuracy. Result: Founding showed that the closed stance forehand stroke has far better percentage of success and accuracy among the intermediate tennis players, but the difference was not significant. In addition, male players showed more accuracy and success in this research. And also accuracy did not have any influence to choice of forehand stroke among the intermediate tennis players. Conclusion: This research could improve the training protocol design for teaching the closed stance and open stance strokes. Keywords: Forehand stroke, open stance, closed stance, tennis accuracy, percentage of success

  11. Impact of Fitness Characteristics on Tennis Performance in Elite Junior Tennis Players.

    Science.gov (United States)

    Ulbricht, Alexander; Fernandez-Fernandez, Jaime; Mendez-Villanueva, Alberto; Ferrauti, Alexander

    2016-04-01

    The impact of fitness characteristics on tennis performance in adolescent players is not clearly understood. Therefore, the aim of the present study was to test whether physical characteristics are related to players' competitive level (i.e., national youth ranking). A secondary aim was to compare adolescent tennis players by performance level (i.e., regional selected players and the national team). A total of 902 male and female junior players (aged, 11-16 years) in Germany were evaluated using a physical testing battery: grip strength; countermovement jump; 10 and 20-m sprint; tennis-specific sprint; overhead, forehand, and backhand medicine ball throws (MBT); serve velocity and tennis-specific endurance test (hit and turn tennis test). Results showed that serve velocity (r = -0.43 to 0.64 for female subjects [♀]; r = -0.33 to 0.49 for male subjects [♂]) and upper-body power (e.g., MBT r = -0.26 to -0.49 ♀; r = -0.20 to -0.49 ♂) were the most correlated predictors of tennis performance (i.e., national youth ranking) in both female and male tennis players. Moreover, national selected players showed better performance levels than their regional counterparts, mainly in the most predictive physical characteristics (i.e., serve velocity: effect size [ES], 0.78-1.04 ♀; ES 0.92-1.02 ♂, MBT: ES, 0.66-0.88 ♀; ES, 0.67-1.04 ♂) and specific endurance (ES, 0.05-0.95 ♀; ES, 0.31-0.73 ♂). The present findings underline the importance of certain physical attributes, especially serve velocity and strength- and power-related variables (upper body), and suggest the need to include these parameters in the area of training, physical testing, and talent identification of young tennis players.

  12. Training volume and soft tissue injury in professional and non-professional rugby union players: a systematic review.

    Science.gov (United States)

    Ball, Shane; Halaki, Mark; Orr, Rhonda

    2017-07-01

    To investigate the relationship between training volume and soft tissue injury incidence, and characterise soft tissue injury in rugby union players. A systematic search of electronic databases was performed. The search strategy combined terms covering: training volume and injury, and rugby union, and players of all levels. Medline, SPORTDiscus, Web of Science, Embase, PubMed. Studies were included if they reported: male rugby union players, a clear definition of a rugby union injury, the amount of training volume undertaken by participants, and epidemiological data for soft-tissue injuries including the number or incidence. 15 studies were eligible for inclusion. Overall match and training injury incidence ranged from 3.3 to 218.0 injuries/1000 player match hours and 0.1-6.1 injuries/1000 player training hours, respectively. Muscle and tendon as well as joint (non-bone) and ligament injuries were the most frequently occurring injuries. The lower limb was the most prevalent injury location. Injury incidence was higher in professional rugby union players than non-professional players. Contact events were responsible for the greatest injury incidence. For non-contact mechanisms, running was responsible for the highest injury incidence. Inconsistent injury definitions hindered reliable comparison of injury data. The lack of reporting training volumes in hours per player per week limited the ability to investigate associations between training volume and injury incidence. A higher level of play may result in higher match injury incidence. Muscle and tendon injuries were the most common type of soft tissue injury, while the lower limb was the most common location of injury in rugby union players, and running was responsible for the highest injury incidence during non-contact events. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. The economic burden of time-loss injuries to youth players participating in week-long rugby union tournaments.

    Science.gov (United States)

    Brown, James C; Viljoen, Wayne; Lambert, Mike I; Readhead, Clint; Fuller, Chelsea; Van Mechelen, Willem; Verhagen, Evert

    2015-07-01

    Rugby Union ("rugby") is a popular sport with high injury risk. Burden of injury is described by the incidence and severity of injury. However reports have ignored the monetary cost of injuries. Therefore the aim of this study was to describe the monetary cost associated with youth rugby injuries. This descriptive study quantified medical treatments of injured players at the South African Rugby Union Youth tournaments in 2011/2012 and the days of work parents missed as a result of the injuries. A health insurer used these data to calculate associated costs. Legal guardians of the 421 injured players were contacted telephonically on a weekly basis until they returned to play. Treatments costs were estimated in South African Rands based on 2013 insurance rates and converted to US$ using purchasing power parities. Of the 3652 players, 2% (n=71) sought medical care after the tournament. For these players, average treatment costs were high (US$731 per player, 95% CI: US$425-US$1096), with fractures being the most expensive type of injury. Players with medical insurance had higher costs (US$937, 95% CI: US$486-US$1500) than those without (US$220, 95% CI: US$145-US$302). Although a minority of players sought follow-up treatment after the tournaments, the cost of these injuries was high. Players without medical insurance having lower costs may indicate that these players did not receive adequate treatment for their injuries. Injury prevention efforts should consider injuries with high costs and the treatment of players without medical insurance. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  14. Head impact exposure sustained by football players on days of diagnosed concussion.

    Science.gov (United States)

    Beckwith, Jonathan G; Greenwald, Richard M; Chu, Jeffrey J; Crisco, Joseph J; Rowson, Steven; Duma, Stefan M; Broglio, Steven P; McAllister, Thomas W; Guskiewicz, Kevin M; Mihalik, Jason P; Anderson, Scott; Schnebel, Brock; Brolinson, P Gunnar; Collins, Michael W

    2013-04-01

    This study compares the frequency and severity of head impacts sustained by football players on days with and without diagnosed concussion and to identify the sensitivity and specificity of single-impact severity measures to diagnosed injury. One thousand two hundred eight players from eight collegiate football teams and six high school football teams wore instrumented helmets to measure head impacts during all team sessions, of which 95 players were diagnosed with concussion. Eight players sustained two injuries and one sustained three, providing 105 injury cases. Measures of head kinematics (peak linear and rotational acceleration, Gadd severity index, head injury criteria (HIC15), and change in head velocity (Δv)) and the number of head impacts sustained by individual players were compared between days with and without diagnosed concussion. Receiver operating characteristic curves were generated to evaluate the sensitivity and specificity of each kinematic measure to diagnosed concussion using only those impacts that directly preceded diagnosis. Players sustained a higher frequency of impacts and impacts with more severe kinematic properties on days of diagnosed concussion than on days without diagnosed concussion. Forty-five injury cases were immediately diagnosed after head impact. For these cases, peak linear acceleration and HIC15 were most sensitive to immediately diagnosed concussion (area under the curve = 0.983). Peak rotational acceleration was less sensitive to diagnosed injury than all other kinematic measures (P = 0.01), which are derived from linear acceleration (peak linear, HIC15, Gadd severity index, and Δv). Players sustained more impacts and impacts of higher severity on days of diagnosed concussion than on days without diagnosed concussion. In addition, of historical measures of impact severity, those associated with peak linear acceleration are the best predictors of immediately diagnosed concussion.

  15. Leg muscle power in 12-year-old black and white Tunisian football players.

    Science.gov (United States)

    Ben Ayed, Karim; Latiri, Imed; Dore, Eric; Tabka, Zouhair

    2011-04-01

    This study examined leg muscle power of young male Tunisian black and white football players and extended the analysis to determine whether there is a relationship between cycling peak power output (PPO) and some field tests. A total of 113 children (white group (WG) = n = 56; black group (BG) = n = 57) participated in this investigation. Anthropometric data included age, body mass (BM), height, leg length (LL), body mass index (BMI), and leg muscle volume (LMV). Cycling PPO was measured including a force-velocity test. Peak power output (PPO; W and W/kg), Fopt (optimal braking force), and Vopt (optimal velocity) were significantly higher in the WG compared with the BG (p velocity test as explanatory factors showed that 33% of the variance of PPO of BG was explained by qualitative factors that may be related to cycling skill, muscle composition, and socioeconomic and training status.

  16. Shorter time to first injury in first year professional football players: A cross-club comparison in the Australian Football League.

    Science.gov (United States)

    Fortington, Lauren V; Berry, Jason; Buttifant, David; Ullah, Shahid; Diamantopoulou, Kathy; Finch, Caroline F

    2016-01-01

    Australian Football League (AFL) players have a high risk of injury. Anecdotally, this injury risk is greater in emerging players (i.e. those in their first year), compared with established players (with 3+ years of experience). This study aimed to conduct the first comparison of injury risk and playing experience in these two player groups across a large number of AFL clubs. Prospective, cohort. Injuries, game participation and training participation were collected weekly by 8 AFL clubs for 61 emerging and 64 established players. Injury incidence rates (IIR) and Cox proportional hazard models for time to first injury, separately for games and training, were computed. The game IIR was significantly higher for emerging than established players: 45.6 (95% CI: 35.7, 57.6) versus 18.3 (95% CI: 13.1, 24.9) per 1000 game-hours. Emerging players also had a higher training IIR than did the established players: 9.6 (95% CI: 7.6, 11.9) versus 8.9 (95% CI: 7.0, 11.1) per 1000 training-hours. Emerging players were significantly less likely to remain injury free in games than established players (HR=3.46, 95% CI: 1.27, 9.45). A similar outcome was seen in training sessions, although to a lesser degree (HR=1.41, 95% CI: 1.19, 1.69). Despite efforts to modify the playing/training program of emerging players, this group remain at greater risk of injury in games and training sessions, compared with established players. Continued efforts should be made toward understanding reasons for this increased risk to better prevent injury during the early years of a professional football career. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  17. Morphology of young handball players

    Directory of Open Access Journals (Sweden)

    Adair da Silva Lopes

    2007-06-01

    Full Text Available The purpose of this study was to compare anthropometric and body composition variables from the best male handball athletes competing in the Santa Catarina state youth competition to variables from the other athletes in the same competition, by game position. Seven of the twelve coaches participating in the Santa Catarina Open Youth Games 2004 (up to 18 years freely consented to select the seven best athletes in the competition (one goalkeeper, one pivot, two wingers and three backcourt players. In addition to these seven players, there were a further 79 team members taking part, bringing the total sample size to 86 athletes. The following variables were analyzed: body weight (MC, height (ES, arm span (ENV, hand breadth (DPA, wrist breadth (DRU, forearm circumference (PA, percentage fat (%G, fat mass (MG and lean body mass (MCM. Descriptive statistics (means and standard deviations were employed to classify the athletes according to court position. The chosen athletes were compared with the others using the single-sample t test (p RESUMO Este estudo objetivou comparar variáveis antropométricas e da composição corporal dos melhores atletas de uma competição juvenil (até 18 anos de handebol masculino de Santa Catarina, em relação aos demais atletas da competição por posição de jogo. Sete dentre os doze técnicos participantes dos Joguinhos Abertos de Santa Catarina 2004 aceitaram, voluntariamente, realizar a escolha da seleção dos sete melhores atletas da competição (um goleiro, um pivô, dois extremas e três armadores. Contabilizou-se, além dos sete atletas da seleção, mais 79 atletas titulares de suas equipes, totalizando na amostra, 86 atletas. Foram analisadas as variáveis: massa corporal (MC, estatura (ES, percentual de gordura (%G, massa de gordura (MG, massa corporal magra (MCM, envergadura (ENV, diâmetro palmar (DPA, diâmetro biestilóide rádio-ulnar (DRU e perímetro do antebraço (PA. Utilizou-se a estat

  18. Analysis of male volleyball players' motor activities during a top level match.

    Science.gov (United States)

    Mroczek, Dariusz; Januszkiewicz, Aleksander; Kawczyński, Adam S; Borysiuk, Zbigniew; Chmura, Jan

    2014-08-01

    The present study aims to assess motor activity of volleyball players using an original video recording method developed by the authors. Twenty-eight volleyball players taking part in 4 matches of the Polish Volleyball League were examined. The recorded data were analyzed in view of the mean total distance covered by volleyball players on different court positions during a match, set, and rally. The results showed that volleyball players cover the mean total distance of 1221 ± 327 m (mean ± SD) in a 3-set match, and 1757 ± 462 m in a 4-set match. A statistically significant difference (p ≤ 0.005) was found between the distance covered by the middle blockers and setters, defenders, spikers, and libero players in a match and in a set. The study revealed a tendency to lengthen the distance by the players in the final sets, which is indicative of the extended time of individual rallies. The mean distance covered in a single rally amounted to 10.92 ± 0.9 m in 4 matches (between 9.12 and 12.56 m). Considering the limited size of the field of play, volleyball players cover relatively long distances during a match and individual sets, with the shortest distance covered by middle blockers, and the longest by setters. From a practical application point of view, detailed topographic analysis of a player's movements on the court as well as precise data on the time of activity and rest breaks provide the coach with valuable information on the ways of development of arrhythmic, changing and dynamic training loads.

  19. Kinetic Post-match Fatigue in Professional and Youth Soccer Players During the Competitive Period

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    Djaoui

    2016-03-01

    Full Text Available Background No previous research has analysed kinetic fatigue of elite adult players and elite youth players during the competitive period. Objectives The aim of the present study was to analyse kinetic post-match fatigue in professional and youth soccer players during the competitive period. Materials and Methods resting heart rate (HRrest, post-effort recovery heart rate (HRrecovery, rate of perceived exertion fatigue (RPEf, muscle soreness and blood samples with creatine kinase (CK and resting lactate (La from nine professional soccer players were measured immediately before, 24 hour and 48 hour after two official French first league matches (Ligue 1 whereas RPEf, HRrest, and 20m speed performance (speed-20 m were measured in ten U-17 elite players immediately before, 24 hour and 48h after a friendly match. Results for professionals, a soccer match elevated all physiological markers during the next 24 hours (P < 0.05; only HRrecovery remained significantly different 48 hours after the match (P < 0.05 whereas there was no variation of HRrest, RPEf, and speed-20m, which were elevated until 24h and got back to reference values 48 hours after the match (P < 0.05 for the U17 players. Comparing the two groups, HRrest results remained lower all the time for professionals, and RPEf was lower for U-17, 24 hours after the match (P < 0.05. Conclusions Independent of their level, professional soccer players, need 48 hours to recover after an official match. Professionals gain more fatigue than young players after a match, but recover as fast. Thus, they recover more efficiently especially due to a better physical condition and fitness training. It is expected that the results showed in the study help elite soccer and fitness coaches to manage the training load of the team according to the match.

  20. Prevalence of Dehydration Before Training Sessions, Friendly and Official Matches in Elite Female Soccer Players

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    Castro-Sepulveda Mauricio

    2016-04-01

    Full Text Available This study aimed to evaluate and compare the hydration states prior to different sporting events (training sessions, friendly and official matches in elite female soccer players and relate that to the importance that the player attached to the hydration state as a determinant of sports performance. The hydration state of 17 female elite soccer players (age: 21.5 ± 3 years; body mass: 62 ± 6 kg; body height: 165 ± 9 cm was determined by measuring their urine specific gravity (USG prior to three different sports events: training sessions (PT, friendly (PF and official (PO matches. The importance that each player attached to the hydration state as a determinant of sports performance was evaluated through a simple questionnaire. An average of 47.05% of the soccer players were severely dehydrated (USG > 1.030, 33.33% were significantly dehydrated (USG > 1.020, 17.64% were mildly dehydrated (USG > 1.010 and 1.96% were euhydrated (USG < 1.010. The average USG was 1.027 ± 0.007 (PT = 1.029 ± 0.009; PF = 1.023 ± 0.010 and PO = 1.030 ± 0.006. Differences were found between urine specific gravity prior to a friendly and an official match (p = 0.03. No relationship was found between urine specific gravity and the importance each player attached to the hydration state as a determinant of sports performance. The results show that dehydration is the most prevalent hydration state of elite soccer players before training sessions, friendly and official matches. Players were most dehydrated prior to official matches, which was unlinked to the players’ perceived importance of hydration for sports performance.

  1. Multiobjective Interaction Programming Problem with Interaction Constraint for Two Players

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    Min Jiang

    2012-01-01

    Full Text Available This paper extends an existing cooperative multi-objective interaction programming problem with interaction constraint for two players (or two agents. First, we define an s-optimal joint solution with weight vector to multi-objective interaction programming problem with interaction constraint for two players and get some properties of it. It is proved that the s-optimal joint solution with weight vector to the multi-objective interaction programming problem can be obtained by solving a corresponding mathematical programming problem. Then, we define another s-optimal joint solution with weight value to multi-objective interaction programming problem with interaction constraint for two players and get some of its properties. It is proved that the s-optimal joint solution with weight vector to multi-objective interaction programming problem can be obtained by solving a corresponding mathematical programming problem. Finally, we build a pricing multi-objective interaction programming model for a bi-level supply chain. Numerical results show that the interaction programming pricing model is better than Stackelberg pricing model and the joint pricing model.

  2. Muscle power and repeated sprint ability in soccer players

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    Saray Giovana dos Santos

    2010-06-01

    Full Text Available Muscle power is one of the most important physical qualities of soccer playerperformance and needs to be maintained during a match. Thus, the aim of this study was toinvestigate the levels of muscle power in soccer players before and after performing repeatedsprints (RS, and the association between power and RS performance. Twenty soccer playersfrom the under-20 category aged 18-20 years participated in this study. The study consisted ofthe execution of vertical jumps, execution of RS, new execution of vertical jumps, and collectionof blood samples. The continuous jump (CJ test was performed on a piezoelectric force platformfor the measurement of muscle power and the RAST test was used to evaluate RS ability. Nosignificant difference in the levels of muscle power was observed after RS (p=0.57. Significantdifferences were observed in the first to fifth sprint times (p<0.01, but not between the fifth andsixth sprint (p=0.06. CJ height before RS was correlated with first sprint time (r=-0.62, p<0.01,best sprint time (r=-0.60, p<0.01, and average sprint time (r= -0.54, p<0.01. In conclusion,the soccer players studied showed no significant reduction in muscle power after RS. A decreasein performance was observed from the first to the fifth sprint, but not between the fifth and sixthsprint. The muscle power of soccer players was a determinant factor to perform one maximumsprint, as well as successive sprints.

  3. MUSCLE DAMAGE AFTER A TENNIS MATCH IN YOUNG PLAYERS

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    R.V. Gomes

    2014-07-01

    Full Text Available The present study investigated changes in indirect markers of muscle damage following a simulated tennis match play using nationally ranked young (17.6 ± 1.4 years male tennis players. Ten young athletes played a 3-hour simulated match play on outdoor red clay courts following the International Tennis Federation rules. Muscle soreness, plasma creatine kinase activity (CK, serum myoglobin concentration (Mb, one repetition maximum (1RM squat strength, and squat jump (SJ and counter movement jump (CMJ heights were assessed before, immediately after, and 24 and 48 h after the simulated match play. All parameters were also evaluated in a non-exercised group (control group. A small increase in the indirect markers of muscle damage (muscle soreness, CK and Mb was detected at 24-48 hours post-match (p<0.05. A marked acute decrement in neuromuscular performance (1RM squat strength: -35.2 ± 10.4%, SJ: -7.0 ± 6.0%, CMJ: -10.0 ± 6.3% was observed immediately post-match (p<0.05. At 24 h post-match, the 1RM strength and jump heights were not significantly different from the baseline values. However, several players showed a decrease of these measures at 24 h after the match play. The simulated tennis match play induced mild muscle damage in young players. Coaches could monitor changes in the indirect markers of muscle damage to assess athletes’ recovery status during training and competition.

  4. Kinanthropometry of Group I rugby players in Buenos Aires, Argentina.

    Science.gov (United States)

    Holway, Francis Edward; Garavaglia, Romina

    2009-09-01

    The large variability in size and structure between playing positions in rugby merits specific kinanthropometric profiling. We aim to report detailed descriptive anthropometric data of a sample of 133 rugby players stratified by field positions (age 24.3 +/- 3.6 years, body mass 89.5 +/- 13.2 kg, and stature 178.8 +/- 7.3 cm) belonging to seven Group I teams competing in the Buenos Aires Rugby Union, and to find out if front row forwards (FR) have larger muscle and skeletal parameters. Body composition was analysed with the five-way fractionation method, expressing tissue masses in absolute terms, relative to weight as percentages and to stature as phantom z-scores. Furthermore, somatotype, body mass index, sum of six skinfolds, and muscle-to-bone ratio were calculated. Players were subsequently grouped into three positional clusters and muscular-skeletal elements compared, showing FR to have larger proportional muscle and skeletal structure than remaining forwards and backs (P < 0.001), albeit a similar muscle-to-bone ratio (P = 0.060). When compared to a sample of the top six teams at the 2003 Rugby World Cup, the Buenos Aires players were considerably smaller, measuring, on average, 3-11 cm less in height and 6-13 kg less in weight.

  5. Improved control of exogenous attention in action video game players

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    Matthew S Cain

    2014-02-01

    Full Text Available Action video game players have demonstrated a number of attentional advantages over non-players. Here, we propose that many of those benefits might be underpinned by improved control over exogenous (i.e., stimulus-driven attention. To test this we used an anti-cuing task, in which a sudden-onset cue indicated that the target would likely appear in a separate location on the opposite side of the fixation point. When the time between the cue onset and the target onset was short (40 ms, non-players (nVGPs showed a typical exogenous attention effect. Their response times were faster to targets presented at the cued (but less probable location compared with the opposite (more probable location. Video game players (VGPs, however, were less likely to have their attention drawn to the location of the cue. When the onset asynchrony was long (600 ms, VGPs and nVGPs were equally able to endogenously shift their attention to the likely (opposite target location. In order to rule out processing-speed differences as an explanation for this result, we also tested VGPs and nVGPs on an attentional blink task. In a version of the attentional blink task that minimized demands on task switching and iconic memory, VGPs and nVGPs did not differ in second target identification performance (i.e., VGPs had the same magnitude of attentional blink as nVGPs, suggesting that the anti-cuing results were due to flexible control over exogenous attention rather than to more general speed-of-processing differences.

  6. Sports injuries in Plus League volleyball players.

    Science.gov (United States)

    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

  7. Imaging of Glial Cell Activation and White Matter Integrity in Brains of Active and Recently Retired National Football League Players

    Science.gov (United States)

    Coughlin, Jennifer M.; Wang, Yuchuan; Minn, Il; Bienko, Nicholas; Ambinder, Emily B.; Xu, Xin; Peters, Matthew E.; Dougherty, John W.; Vranesic, Melin; Koo, Soo Min; Ahn, Hye-Hyun; Lee, Merton; Cottrell, Chris; Sair, Haris I.; Sawa, Akira; Munro, Cynthia A.; Nowinski, Christopher J.; Dannals, Robert F.; Lyketsos, Constantine G.; Kassiou, Michael; Smith, Gwenn; Caffo, Brian; Mori, Susumu; Guilarte, Tomas R.; Pomper, Martin G.

    2017-01-01

    IMPORTANCE Microglia, the resident immune cells of the central nervous system, play an important role in the brain’s response to injury and neurodegenerative processes. It has been proposed that prolonged microglial activation occurs after single and repeated traumatic brain injury, possibly through sports-related concussive and subconcussive injuries. Limited in vivo brain imaging studies months to years after individuals experience a single moderate to severe traumatic brain injury suggest widespread persistent microglial activation, but there has been little study of persistent glial cell activity in brains of athletes with sports-related traumatic brain injury. OBJECTIVE To measure translocator protein 18 kDa (TSPO), a marker of activated glial cell response, in a cohort of National Football League (NFL) players and control participants, and to report measures of white matter integrity. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional, case-control study included young active (n = 4) or former (n = 10) NFL players recruited from across the United States, and 16 age-, sex-, highest educational level-, and body mass index-matched control participants. This study was conducted at an academic research institution in Baltimore, Maryland, from January 29, 2015, to February 18, 2016. MAIN OUTCOMES AND MEASURES Positron emission tomography-based regional measures of TSPO using [11C]DPA-713, diffusion tensor imaging measures of regional white matter integrity, regional volumes on structural magnetic resonance imaging, and neuropsychological performance. RESULTS The mean (SD) ages of the 14 NFL participants and 16 control participants were 31.3 (6.1) years and 27.6 (4.9) years, respectively. Players reported a mean (SD) of 7.0 (6.4) years (range, 1–21 years) since the last self-reported concussion. Using [11C]DPA-713 positron emission tomographic data from 12 active or former NFL players and 11 matched control participants, the NFL players showed higher total

  8. The effects of injury preventive warm-up programs on knee strength ratio in young male professional soccer players.

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    Abdolhamid Daneshjoo

    Full Text Available PURPOSE: We aimed to investigate the effect of FIFA 11+ (11+ and HarmoKnee injury preventive warm-up programs on conventional strength ratio (CSR, dynamic control ratio (DCR and fast/slow speed ratio (FSR in young male professional soccer players. These ratios are related to the risk of injury to the knee in soccer players. METHODS: Thirty-six players were divided into 3 groups; FIFA 11+, HarmoKnee and control (n = 12 per group. These exercises were performed 3 times per week for 2 months (24 sessions. The CSR, DCR and FSR were measured before and after the intervention. RESULTS: After training, the CSR and DCR of knee muscles in both groups were found to be lower than the published normal values (0.61, 0.72, and 0.78 during 60°.s(-1, 180°.s(-1 and 300°.s(-1, respectively. The CSR (60°.s(-1 increased by 8% and FSR in the quadriceps of the non-dominant leg by 8% in the 11+. Meanwhile, the DCR in the dominant and non-dominant legs were reduced by 40% and 30% respectively in the 11+. The CSR (60°.s(-1 in the non-dominant leg showed significant differences between the 11+, HarmoKnee and control groups (p = 0.02. As for the DCR analysis between groups, there were significant differences in the non-dominant leg between both programs with the control group (p = 0.04. For FSR no significant changes were found between groups. CONCLUSIONS: It can be concluded that the 11+ improved CSR and FSR, but the HarmoKnee program did not demonstrate improvement. We suggest adding more training elements to the HarmoKnee program that aimed to enhance hamstring strength (CSR, DCR and FSR. Professional soccer players have higher predisposition of getting knee injuries because hamstring to quadriceps ratio were found to be lower than the average values. It seems that the 11+ have potentials to improve CSR and FSR as well as prevent knee injuries in soccer players.

  9. Performance enhancement among adolescent players after 10 weeks of pitching training with appropriate baseball weights.

    Science.gov (United States)

    Yang, Wen-Wen; Liu, Ya-Chen; Lu, Lee-Chang; Chang, Hsiao-Yun; Chou, Paul Pei-Hsi; Liu, Chiang

    2013-12-01

    Compared with regulation-weight baseballs, lightweight baseballs generate lower torque on the shoulder and elbow joints without altering the pitching movement and timing. This study investigates the throwing accuracy, throwing velocity, arm swing velocity, and maximum shoulder external rotation (MSER) of adolescent players after 10 weeks of pitching training with appropriate lightweight baseballs. We assigned 24 adolescent players to a lightweight baseball group (group L) and a regulation-weight baseball group (group R) based on their pretraining throwing velocity. Both groups received pitching training 3 times per week for 10 weeks with 4.4- and 5-oz baseballs. The players' throwing accuracy, throwing velocity, arm swing velocity, and MSER were measured from 10 maximum efforts throws using a regulation-weight baseball before and after undergoing the pitching training. The results showed that the players in group L significantly increased their throwing velocity and arm swing velocity (p baseball, whereas group R did not (p > 0.05). Furthermore, the percentage change in the throwing velocity and arm swing velocity of group L was significantly superior to that of group R (p baseball substantially enhanced the arm swing velocity and throwing velocity of the adolescent baseball players. These findings suggest that using a lightweight baseball, which can reduce the risk of injury without altering pitching patterns, has positive training effects on players in the rapid physical growth and technique development stage.

  10. The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players.

    Science.gov (United States)

    Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

    2015-01-01

    The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players' knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p muscular imbalances in post-adolescent soccer players.

  11. EFFECT OF INFORMATION PROCESSING AND DEPTH PERCEPTION UPON THROWING ACCURACY OF BASKETBALL PLAYERS

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    Singh Virendra Kumar

    2015-02-01

    Full Text Available Purpose: The purpose of the present study is to analyze throwing accuracy of basketball players in relation to their reasoning ability and depth perception. Materials and Methods : For present study, 200 intercollegiate basketball players (Ave. age = 21.34±1.87 years were selected as sample. Johnson Basketball Throw for Accuracy (Passing Test was the instrument which was used to assess shooting skills of selected subjects whereas reasoning ability of the selected subjects was assessed by MGTI prepared by Mehrotra (1984. To conduct the study, a 2x2 factorial design was used. Superior and inferior reasoning and perceptual abilities were ascertained by statistical method Q1 and Q3. 2x2 ANOVA results showed that the main effect of reasoning ability was not found to be statistically significant upon throwing accuracy of basketball players although it is close to .05 level of significance. Results : The main effect of depth perception upon throwing accuracy of basketball players turned out to be statistically significant. The two factor interaction effect of reasoning ability and depth perception upon throwing accuracy of basketball players was found to be statistically insignificant. Conclusion : It was concluded that reasoning ability and to some extent depth perception, are the two major variables which generate variance upon throwing accuracy of basketball players.

  12. Serum S-100B protein levels in young amateur soccer players after controlled heading and normal exercise.

    Science.gov (United States)

    Mussack, T; Dvorak, J; Graf-Baumann, T; Jochum, M

    2003-10-22

    Repeated impacts by heading might lead to significant head injuries in soccer players comparable to those of patients with accidental minor traumatic brain injury (TBI). The neuroprotein S-100B released into the circulation is suggested to be a reliable marker indicating brain damage. The objective was to evaluate the neuroprotein S-100B serum levels in young amateur soccer players early after controlled heading compared to early measurements after normal exercise as well as in other patients after minor TBI. Sixty-one male amateur soccer players (median age 15.3 years) performed controlled heading aimed at the forehead for 55 minutes. Data were compared to 58 male amateur soccer players (15.9 years) performing 61 minutes of normal exercise training without head contact and 81 young male patients early after TBI who underwent computed tomography (CCT) for detection of intracranial lesions. First venous blood samples were drawn before the training sessions, second and third samples 60 and 360 minutes after heading or 64 and 355 minutes after exercise, respectively, 65 and 366 minutes after TBI. Median S-100B serum levels of the heading group only slightly increased from 0.15 ng/ml to 0.18 ng/ml 60 minutes after end of training. Within 360 minutes S-100B values decreased again to 0.15 ng/ml reaching the initial values. S-100B serum values of the exercise group showed a similar transient increase exhibiting significant lower levels before exercise (0.10 ng/ml) as well as 64 minutes (0.11 ng/ml) and 355 minutes after exercise (0.09 ng/ml) compared to the heading group. According to age stratification in the heading group, starting median S-100B levels were significantly higher in subjects with 12-13 years (0.22 ng/ml) and 14-15 years (0.17 ng/ml) compared to those with 16-17 years of age (0.06 ng/ml). None of the subcollectives did reach median S-100B levels of the CCT+ group (n = 20) at admission (0.62 ng/ml) or 366 minutes later (0.32 ng/ml), which were significantly

  13. Should player fatigue be the focus of injury prevention strategies for international rugby sevens tournaments?

    Science.gov (United States)

    Fuller, Colin W; Taylor, Aileen E; Raftery, Martin

    2016-06-01

    To assess the incidence, severity and nature of injuries, to determine risk factors for injury and to identify potential injury prevention strategies in men's international Rugby-7s tournaments. A prospective cohort study. Players from core teams competing in matches at 6 Sevens World Series from 2008/2009 to 2014/2015. The incidence of injury across all Series was 108.3 injuries/1000 player-match-hours (backs: 121.0; forwards: 91.5) with a mean severity of 44.2 days (backs: 46.1; forwards: 40.9) and a median severity of 28 days (backs: 29; forwards: 26). The proportion of injuries sustained in the second half was significantly higher (60%; pRugby-7s suggests that teams require squads of around 20 players for a Sevens World Series. The higher incidence of injury in the second half of matches is probably the result of player fatigue; therefore, injury prevention strategies for teams and the Governing Body should address this issue. The results presented support the World Rugby trial allowing 'rolling substitutes' during Sevens World Series matches, as this approach may help to mitigate the effects of player fatigue during the second half of matches. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Association of anthropometric qualities with vertical jump performance in elite male volleyball players.

    Science.gov (United States)

    Aouadi, R; Jlid, M C; Khalifa, R; Hermassi, S; Chelly, M S; Van Den Tillaar, R; Gabbett, T

    2012-02-01

    The objective of this study was to examine the association between physical and anthropometric profiles and vertical jump performance in elite volleyball players. Thirty-three elite male volleyball players (21±1 y, 76.9±5.2 kg, 186.5±5 cm) were studied. Several anthropometric measurements (body mass, stature, body mass index, lower limb length and sitting height) together with jumping height anaerobic power of counter movement jump with arm swing (CMJarm) were obtained from all subjects. Forward stepwise multiple linear regression analysis was performed to determine if any of the anthropometric parameters were predictive of CMJarm. Anaerobic power was significantly higher (P≤0.05) in the tallest players relative to their shorter counterparts. A significant relationship was observed between CMJarm and lower limb length (r2=0.69; P0.05) predictors of CMJarm performance. This study demonstrates that lower limb length is correlated with CMJarm in elite male volleyball players. The players with longer lower limbs have the better vertical jump performances and their anaerobic power is higher. These results could be of importance for trained athletes in sports relying on jumping performance, such as basketball, handball or volleyball. Thus, the measurement of anthropometric characteristics, such as stature and lower limb length may assist coaches in the early phases of talent identification in volleyball.

  15. Real-time MRI comparisons of brass players: A methodological pilot study.

    Science.gov (United States)

    Iltis, Peter W; Schoonderwaldt, Erwin; Zhang, Shuo; Frahm, Jens; Altenmüller, Eckart

    2015-08-01

    This paper describes the use of real-time MRI at 30 frames/s in studying motor function within the oropharyngeal cavity of a trumpet, horn, trombone, and tuba player. Using Image J and customized MB-Ruler Pro software, analyses of discrete 33.3 ms snapshots of motion extracted from real-time MRI films obtained during an ascending five note sequence performed on a plastic practice device (B.E.R.P.) revealed inter-instrument differences in oropharyngeal cavity size and tongue conformation when moving from lower to higher notes. Tuba and trombone show a progressive decrease in oropharyngeal area featuring an upward and forward displacement of the tongue. Trumpet showed progressive increases in oropharyngeal area, with the posterior compartment showing the largest change, while horn essentially showed no change. A novel dynamic quantitative analysis method is also described utilizing Matlab. This method employs user-specified line profiles, aligned to the direction of the movement of interest. It takes advantage of time-varying pixel luminescence to derive spatial and temporal gradients. These gradients make possible the acquisition of kinematic data to describe movement in terms of slower position changes (spatial gradient) as well as fast, articulatory movements (temporal gradient). Spatial gradient analysis for the trumpet player demonstrates a progressive raising of the tongue during the ascending five note exercise. Temporal gradient analysis of double-tonguing revealed similarities in range of motion, anti-phase behavior, and frequency across instruments with respect to movements of the tongue tip and back of tongue. The paper concludes by making recommendations for extending these methods to studying musician's dystonia.

  16. Effect of training on the serum lipid profile in able-bodied and spinal cord injured rugby players

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    E Hübner-Woźniak

    2010-12-01

    Full Text Available The aim of the present study was to examine the effect of rugby training on the serum lipid profile in able-bodied and wheelchair players. The following groups took part in the study: sedentary able-bodied men (Group M, n=10, inactive disabled men using wheelchairs (Group MW, n=10, semiprofessional rugby players (Group R, n=10, and wheelchair rugby players (Group RW, n=10. The serum triacyloglycerols (TG, the total cholesterol (TC, the LDL cholesterol (LDLchol and the HDL cholesterol (HDLchol concentrations were assayed. The total cholesterol and the LDL cholesterol concentrations were higher in able-bodied sedentary men compared to non-disable rugby players. There was also a tendency to higher HDL cholesterol concentration in rugby players compared to sedentary men (Group R vs. M. Rugby training resulted in a significant decrease of the LDL cholesterol and an increase in the HDL cholesterol concentration, as well as a tendency for lower total cholesterol levels in wheelchair players compared to sedentary tetraplegic men. The ratio of the total cholesterol to the HDL cholesterol was significantly lower in both groups of rugby players in comparison to the respective groups of sedentary men. The serum triacyloglycerols (TG concentration was similar in all studied groups. There was no difference in the serum lipid profile and the TC/HDLchol ratio between sedentary able-bodied and disabled men (Group M vs. MW, just as between non-disabled and wheelchair rugby players (R vs. RW. It seems that rugby training had a beneficial effect on the serum lipid profile in able-bodied as well as wheelchair players. These results confirm that active persons are at lower risk of cardiovascular diseases.

  17. COMPARING ANALYSIS OF ANTHROPOMETRICS CHARACTERISTICS AND FUNCTIONAL ABILITIES OF TOP FEMALE FOOTBALL PLAYERS AND OF FEMALE WHO DOESN'T TRAIN ANY SPORT ACTIVELY

    Directory of Open Access Journals (Sweden)

    Ivana Mladenovic

    2003-10-01

    Full Text Available Football is very popular game all over the world and in SCG as well.Every year in Yugoslavia girls and women are from 7 to 40 years take part in the game of football as a sport as well as a sort of recreation. Technically and tactically this game more and more resembles the male football. The process of training is close to the very edge of female abilities, so we have dynamic game full of duel, long shots and spectacular goals.The aim of this research is to confirm differences of developing characteristics and functional abilities female football players and women who don't train any sport actively.The research encircled 20 female football players members of football club Masinac (winner of 2003 competition. The control group consisted of 20 female students who didn't go in for any sport actively.The results show that the average height of female football players is 166.85 ± 5.47 cm and average height of control group is 166.11 ± 5.6 cm. Relative values of maximal oxygen up take is 63.14 ± 8.11 ml/min/kg and 55.43 ± 7.25 for control group. This result show that bought group have aerobic abilities higher than one of average women (30-40 ml/min/kg.

  18. Parameter Improvement of the Soccer League Competition Algorithm by Introducing Stubborn Players: Application to Water Distribution Network

    Directory of Open Access Journals (Sweden)

    Godfrey Chagwiza

    2016-01-01

    Full Text Available A modified soccer league algorithm is presented in this paper. The effect of stubborn fixed players is investigated and the algorithm is implemented to three benchmark water distribution networks. The modified algorithm is compared to several algorithms. The results show that the modified algorithm performs better than the soccer league competition algorithm, in particular, on the average number of evaluations required to find the optimal cost. Computational results show that the utility benefit of both the individual player and team is essential. The algorithm becomes more reliable when utility benefits are high and as the number of fixed players increases.

  19. Anthropometric and physical characteristics allow differentiation of young female volleyball players according to playing position and level of expertise

    Science.gov (United States)

    Milić, M; Grgantov, Z; Chamari, K; Bianco, A; Padulo, J

    2016-01-01

    The aim of our study was to determine the differences in some anthropometric and physical performance variables of young Croatian female volleyball players (aged 13 to 15) in relation to playing position (i.e., independent variable) and performance level within each position (i.e., independent variable). Players were categorized according to playing position (i.e., role) as middle blockers (n=28), opposite hitters (n=41), passer-hitters (n=54), setters (n=30), and liberos (n=28). Within each position, players were divided into a more successful group and a less successful group according to team ranking in the latest regional championship and player quality within the team. Height and body mass, somatotype by the Heath-Carter method, and four tests of lower body power, speed, agility and upper body power (i.e., dependent variables) were assessed. Players in different positions differed significantly in height and all three somatotype components, but no significant differences were found in body mass, body mass index or measured physical performance variables. Players of different performance level differed significantly in both anthropometric and physical performance variables. Generally, middle blockers were taller, more ectomorphic, less mesomorphic and endomorphic, whereas liberos were shorter, less ectomorphic, more mesomorphic and endomorphic than players in other positions. More successful players in all positions had a lower body mass index, were less mesomorphic and endomorphic, and more ectomorphic than less successful players. Furthermore, more successful players showed better lower body power, speed, agility and upper body power. The results of this study can potentially provide coaches with useful indications about the use of somatotype selection and physical performance assessment for talent identification and development. PMID:28416892

  20. Anthropometry of World-Class Elite Handball Players According to the Playing Position: Reports From Men's Handball World Championship 2013.

    Science.gov (United States)

    Ghobadi, Hamid; Rajabi, Hamid; Farzad, Babak; Bayati, Mahdi; Jeffreys, Ian

    2013-12-18

    Identifying the anthropometric measures of successful and less successful handball players may be helpful in developing a talent identification and development model, allowing for the determination of key physical capacities required for elite performance. The purpose of the study was to describe the anthropometric characteristics, including age, standing stature, body mass and body mass index (BMI) in handball players who participated in the 2013 Men's Handball World Championships. Secondly, the objective was to identify the possible differences in these parameters in terms of individual playing positions (goalkeeper, back, center back, wing, line player). Rosters with handball player's age, standing stature, and body mass were obtained from the International Handball Federation website. The research material included 409 handball players (24 teams). National teams were organized by their ranks and sub-grouped using their continents and playing positions. The results of the analyses of variance demonstrated significant differences in age (F=2.30; p=0.044; Partial ŋ2=0.028), standing stature (F=14.02; p=0.0001; Partial ŋ2=0.148), and body mass (F=5.88; p=0.0001; Partial ŋ2=0.068) among the groups (G1-G6). Players in G1 had the highest standing stature and body mass, while players in G6 had the lowest age and body mass values. The backs and line players were the tallest. In addition, the measurement of body mass showed that the line players had the highest body mass and BMI values. In conclusion, this study presented anthropometric data that differentiated levels of success in male handball teams playing in the 2013 world championships. This information should serve as a reference for the average standing stature, body mass, and BMI of handball players for particular positions at the professional level.

  1. COMPARISON OF VISUAL ACUITY IN REDUCED LUMINATION AND FACILITY OF OCULAR ACCOMMODATION IN TABLE TENNIS CHAMPIONS AND NON- PLAYERS

    Directory of Open Access Journals (Sweden)

    Ebrahim Jafarzadehpur

    2004-03-01

    Full Text Available A table tennis player should fixate at different distances; track the objects with different speed, and in different visual environment. Their visual skills must be well developed for these capabilities. Therefore, visual acuity in reduced lumination and facility of ocular accommodation those are two criteria for visual skills have been compared in table tennis players and normal non-players. Twenty-nine young table tennis champions and 29 normal matched non-players (did not take part in any racket sports game were evaluated. Basic visual and eye examinations were done for both of them. Normal results in basic examination were fundamental requirement for all the subjects. +/-2.00 sphere lenses for accommodation facility are used. An electrical current regulator changed the output light intensity of a conventional chart projector (Topcon. Light intensity decreased to 10 cd·m-2 and visual acuity tested. In comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non-players there are significant differences (p < 0.001. In the preliminary visual tests there was not any significant different in the two groups but the results in the top level table tennis player was very uniform and in every test and the standard deviation was lesser in tennis player group than non-players. These results show that motor and sensorial functions of expert players are well developed. That is consistent with other researchers. This result was interpreted as reflecting a better perceptual system of experts to the constraints encountered during table tennis and its use in practical settings for evaluating athletes or detecting sport talents. However some visual and perceptual training that usually used in orthoptics can be used for novice table tennis player to improve their abilities

  2. Effects of prolonged intensive training on the resting levels of salivary immunoglobulin A and cortisol in adolescent volleyball players.

    Science.gov (United States)

    Li, T L; Lin, H C; Ko, M H; Chang, C K; Fang, S H

    2012-10-01

    Concerns have been raised regarding the effects of prolonged intensive training on adolescent athletes. This study investigated the differences in mucosal immune functions and stress responses between intensively trained male adolescent volleyball players and age-matched sedentary controls. Twelve male volleyball players (16.5 [0.7] years of age) and sixteen healthy sedentary male volunteers (17.1 [0.6] years of age) participated in this study. Volleyball players were engaged in regular and year-round training. Unstimulated saliva samples were collected from volleyball players during the high-intensity training period and from the counterparts at the same timepoints after at least 18 hours of rest. Concentrations of salivary total protein, secretory immunoglobulin A (SIgA), cortisol, and lactoferrin were measured. Results of this study revealed that the SIgA concentrations and the ratio of SIgA/total protein in volleyball players were significantly lower compared with those in sedentary controls. However, the salivary cortisol concentrations and the ratio of cortisol/total protein in volleyball players were markedly higher compared with those in sedentary controls. No significant difference was observed in lactoferrin levels between volleyball players and sedentary controls. The findings of this study suggest that the prolonged intensive training may elicit a sustained stress and induce a suppressive effect on mucosal immunity in regularly and intensively trained adolescent athletes.

  3. Relationship of Speed, Agility, Neuromuscular Power, and Selected Anthropometrical Variables and Performance Results of Male and Female Junior Tennis Players.

    Science.gov (United States)

    Munivrana, Goran; Filipčić, Aleš; Filipčić, Tjaša

    2015-07-01

    The aim of the study was to analyses the relation between the selected speed, agility, and neuromuscular power test items. The sample of subjects consisted of 154 male and 152 female young tennis players. Using six motor and three anthropometrical tests we investigate differences between males and females and between two age categories. Finally, we analyzed the relation between motor and anthropometrical tests and a player's tennis performance. The correlation between the two agility test items and 5-m sprint is very large in male players, while only moderate with 20-m sprint in female category. Male tennis players have higher correlations between speed test items and neuromuscular test items. The speed test item (5-m sprint) has large correlation with a player's tennis performance. One-way analysis of variance results indicated that young male tennis players performed significantly better than females in all motor test items. Significant differences between genders have not been revealed only in the body mass index. Differences between the males aged 18& under and 16& under have been noted as significant in all test items, except the vertical jump, while differences between the females have been noted as significant in three anthropometrical tests, quarter jump, and the fan-drill test. Regression analyses have shown that the system of prediction variables explains a relatively small part of variance (46%--males and 40%--females). In both genders, it has been revealed that test items measuring speed significantly influence a player's tennis performance.

  4. Risk Factors of Tendo-Achilles Injury in Football, Cricket and Badminton Players at Dhaka, Bangladesh.

    Science.gov (United States)

    Khan, M J; Giasuddin, A S M; Khalil, M I

    2015-04-01

    Achilles tendon is the tendon connecting the heel with the calf muscles. Tendo-achilles injury (TAI) in players is common in games. The frequency of TAI is unknown and aetiology is controversial: The present descriptive cross-sectional study was done to determine the prevalence of TAI and associated factors contributing to it in football, cricket and badminton. From January to June 2012, male players (n = 131), age -17-35 years, were selected by purposive sampling technique from renowned sporting clubs at Dhaka, Bangladesh. TAI was diagnosed through structured questionnaire and interviewing the respondents. The analysis by Statistical Package for Social Sciences (SPSS) programme revealed that 11.5% players suffered from TAI, i.e. prevalence was 115 per 1000 respondents. Most injuries (70/131; 53.4%) occurred in the playground and (59/131; 45.3%) happened in practice field. Injuries among the players of third division were higher, i.e. about 36% (p = 0.000). TAI was significantly dependent on occupation (p = 0.046), BMI (p = 0.008), divisional status (p = 0.023), game type (p = 0.043), ground condition (p = 0.05) and injury severity (p = 0.000). The injured players referred for treatment to the physiotherapist was highest (9/15, i.e. 60%) followed by the physicians (5/15, i.e. 33%) (p = 0.000). The associations of TAI with various factors were discussed suggesting effective measures be taken and treatment, particularly physiotherapy, be given to injured players. However, there is a need of team work with sports medicine specialist also to enable the injured players to continue their professional games.

  5. Motivation and Sport Injuries in Handball Players

    Directory of Open Access Journals (Sweden)

    Laguna, María

    2010-12-01

    Full Text Available The aim of the study was to test whether different levels of motivation are related to the injuries suffered by elite athletes. The sample consists of 80 professional handball players of ASOBAL League, with a mean age of 24.83 years (+ 5.21. Motivation was assessed through the CPRD scale (Gimeno, Buceta & Pérez-Llantada; 1999 and a self-report questionnaire was used to register sports injuries. The results indicate that there is a relationship between motivational levels and the risk for injury. Specifically, players with high motivated players had a greater number of moderate injuries. Although it may seem paradoxical, it is possible that an excessively high motivation leads to overachievement and risk behaviors, which in turn facilitate the appearance of lesions.

  6. Cricket club looking for new players

    CERN Multimedia

    Cricket Club

    2016-01-01

    The CERN Cricket Club, having lost several key players, has had a very difficult season so far and is desperately in need of new players. Having qualified for the Cricket Switzerland semi-finals for the last two years (unfortunately losing both), this year we are bottom of the Western Pool, having played the last two league matches with only 10 players. If you are interested in playing cricket please join us at net practice, which takes place on the Prevessin site each Thursday evening from 18:00 to around 20:00 (weather permitting) or send me an e-mail (see below). Please have a look at the Cricket Club web site for more information: http://cern.ch/Club-Cricket/ Chris Onions, President of the CERN Cricket Club   (christopher.onions@gmail.com)

  7. Big Data for Business Ecosystem Players

    Directory of Open Access Journals (Sweden)

    Perko Igor

    2016-06-01

    Full Text Available In the provided research, some of the Big Data most prospective usage domains connect with distinguished player groups found in the business ecosystem. Literature analysis is used to identify the state of the art of Big Data related research in the major domains of its use-namely, individual marketing, health treatment, work opportunities, financial services, and security enforcement. System theory was used to identify business ecosystem major player types disrupted by Big Data: individuals, small and mid-sized enterprises, large organizations, information providers, and regulators. Relationships between the domains and players were explained through new Big Data opportunities and threats and by players’ responsive strategies. System dynamics was used to visualize relationships in the provided model.

  8. Adapting virtual camera behaviour through player modelling

    DEFF Research Database (Denmark)

    Burelli, Paolo; Yannakakis, Georgios N.

    2015-01-01

    Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...

  9. Mean Field Games with a Dominating Player

    Energy Technology Data Exchange (ETDEWEB)

    Bensoussan, A., E-mail: axb046100@utdallas.edu [The University of Texas at Dallas, International Center for Decision and Risk Analysis, Jindal School of Management (United States); Chau, M. H. M., E-mail: michaelchaumanho@gmail.com; Yam, S. C. P., E-mail: scpyam@sta.cuhk.edu.hk [The Chinese University of Hong Kong, Department of Statistics (Hong Kong, People’s Republic of China) (China)

    2016-08-15

    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 unique existence of the equilibrium control. The proof of the convergence result of finite player game to mean field counterpart is provided in Appendix.

  10. There is no game without a player

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel

    on the subject matter from the catalogue of game theory. All four suggestions exclude the player from the relationship. This paper introduces a phenomenological point of view and includes the player in order to understand the relationship between structure and dressing. It argues that players constitute a bridge......This paper is a search for meaning or to be more precise a study of how meaning is produced between ontology and fiction in computer games. It sets out to investigate the relationship between formal abstract game structures and game representation (dressing) by presenting four suggestions...... or the center which establishes, upholds and renegotiate the relationship between formal game structure and game dressing. It also argues that players’ interaction with both structure and dressing produce meaning and the production of meaning is the relationship between formal abstract game structures and game...

  11. Modulation of motor area activity by the outcome for a player during observation of a baseball game.

    Directory of Open Access Journals (Sweden)

    Sotaro Shimada

    Full Text Available BACKGROUND: Observing competitive games such as sports is a pervasive entertainment among humans. The inclination to watch others play may be based on our social-cognitive ability to understand the internal states of others. The mirror neuron system, which is activated when a subject observes the actions of others, as well as when they perform the same action themselves, seems to play a crucial role in this process. Our previous study showed that activity of the mirror neuron system was modulated by the outcome of the subject's favored player during observation of a simple competitive game (rock-paper-scissors. However, whether the mirror neuron system responds similarly in a more complex and naturalistic sports game has not yet been fully investigated. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we measured the activity of motor areas when the subjects, who were amateur baseball field players (non-pitchers, watched short movie clips of scenes in professional baseball games. The subjects were instructed to support either a batter or a pitcher when observing the movie clip. The results showed that activity in the motor area exhibited a strong interaction between the subject's supported side (batter or pitcher and the outcome (a hit or an out. When the subject supported the batter, motor area activity was significantly higher when the batter made an out than when he made a hit. However, such modulation was not apparent when the subject supported the pitcher. CONCLUSIONS/SIGNIFICANCE: This result indicates that mirror neuron system activity is modulated by the outcome for a particular player in a competitive game even when observing a complex and naturalistic sports game. We suggest that our inclination to watch competitive games is facilitated by this characteristic of the mirror neuron system.

  12. Motor skill failure or flow-experience? Functional brain asymmetry and brain connectivity in elite and amateur table tennis players.

    Science.gov (United States)

    Wolf, Sebastian; Brölz, Ellen; Keune, Philipp M; Wesa, Benjamin; Hautzinger, Martin; Birbaumer, Niels; Strehl, Ute

    2015-02-01

    Functional hemispheric asymmetry is assumed to constitute one underlying neurophysiological mechanism of flow-experience and skilled psycho-motor performance in table tennis athletes. We hypothesized that when initiating motor execution during motor imagery, elite table tennis players show higher right- than left-hemispheric temporal activity and stronger right temporal-premotor than left temporal-premotor theta coherence compared to amateurs. We additionally investigated, whether less pronounced left temporal cortical activity is associated with more world rank points and more flow-experience. To this aim, electroencephalographic data were recorded in 14 experts and 15 amateur table tennis players. Subjects watched videos of an opponent serving a ball and were instructed to imagine themselves responding with a specific table tennis stroke. Alpha asymmetry scores were calculated by subtracting left from right hemispheric 8-13 Hz alpha power. 4-7 Hz theta coherence was calculated between temporal (T3/T4) and premotor (Fz) cortex. Experts showed a significantly stronger shift towards lower relative left-temporal brain activity compared to amateurs and a significantly stronger right temporal-premotor coherence than amateurs. The shift towards lower relative left-temporal brain activity in experts was associated with more flow-experience and lower relative left temporal activity was correlated with more world rank points. The present findings suggest that skilled psycho-motor performance in elite table tennis players reflect less desynchronized brain activity at the left hemisphere and more coherent brain activity between fronto-temporal and premotor oscillations at the right hemisphere. This pattern probably reflect less interference of irrelevant communication of verbal-analytical with motor-control mechanisms which implies flow-experience and predict world rank in experts.

  13. Acute Effects of Two Different Resistance Circuit Training Protocols on Performance and Perceived Exertion in Semiprofessional Basketball Players.

    Science.gov (United States)

    Freitas, Tomás T; Calleja-González, Julio; Alarcón, Francisco; Alcaraz, Pedro E

    2016-02-01

    This study aimed to investigate the acute effects of two different resistance circuit training protocols on basketball players' physical and technical performance and rating of perceived exertion (RPE). In a repeated-measures, crossover experimental design, 9 semiprofessional basketball players performed a Power Circuit Training (PCT; 45% 1RM) and a High-Resistance Circuit Training (HRC; 6RM), on consecutive weeks. Vertical and horizontal jump performance, 3-points shooting accuracy, repeated-sprint ability (RSA), agility, and upper body power output were measured before and after training. The RPE was assessed 20 minutes after resistance training. One-way repeated-measures analysis of variance showed performance decrements in vertical jump height and peak power, horizontal jump distance, 3-points percentage, bench-press power output, RSA total and ideal time, and agility T-Test at total time following HRC, but not PCT (p ≤ 0.05). The RPE was higher in HRC compared with PCT. The results of this study indicated that HRC was perceived as being harder and produced higher fatigue levels, which in turn lowered acute performance. However, low-to-moderate intensity loads did not negatively affect performance. Thus, completing a PCT session may be the most appropriate option before a practice or game as it avoids acute-resistance-training-induced performance decrements. However, if the objective of the basketball session is to develop or perfect technical skills during fatiguing conditions, HRC may be the more suitable option.

  14. Surviving as Foreign-Born Immigrants in America's Higher Education: Eight Exemplary Cases

    Science.gov (United States)

    Eskay, M. K.; Onu, V. C.; Obiyo, N. O.; Igbo, J. N.; Udaya, J.

    2012-01-01

    In every democratically heterogeneous society like America, different players are involved in contributing to the smooth running of its higher education. These players have differentiated body of knowledge with which to make America's higher education a premier one. However, that does not seem to be the case for many foreign-born African…

  15. Injury incidence and balance in rugby players.

    Science.gov (United States)

    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 pscrum-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. Cardiovascular function is better in veteran football players than age-matched untrained elderly healthy men

    DEFF Research Database (Denmark)

    Schmidt, Jakob Friis; Andersen, Thomas Rostgaard; Andersen, Lars Juel

    2015-01-01

    The aim of the study was to determine whether lifelong football training may improve cardiovascular function, physical fitness, and body composition. Our subjects were 17 male veteran football players (VPG; 68.1 ± 2.1 years) and 26 healthy age-matched untrained men who served as a control group (CG......, RHI was 21% higher (P fitness...

  17. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers

    NARCIS (Netherlands)

    Borghuis, Arend Jan; Lemmink, Koen A. P. M.; Hof, At L.

    2011-01-01

    BORGHUIS, A. J., K. A. P. M. LEMMINK, and A. L. HOF. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers. Med. Sci. Sports Exerc., Vol. 43, No. 1, pp. 108-114, 2011. Decreased core stability has been suggested to be associated with a higher occurrence of lower extremit

  18. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers

    NARCIS (Netherlands)

    Borghuis, Arend Jan; Lemmink, Koen A. P. M.; Hof, At L.

    BORGHUIS, A. J., K. A. P. M. LEMMINK, and A. L. HOF. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers. Med. Sci. Sports Exerc., Vol. 43, No. 1, pp. 108-114, 2011. Decreased core stability has been suggested to be associated with a higher occurrence of lower

  19. The functional status of the professional football players during functional testing procedure

    Directory of Open Access Journals (Sweden)

    Pavlichenko P.P.

    2015-11-01

    Full Text Available The purpose of the investigation was the analysis of the functional status of professional football players during the special functional testing procedure (shuttle test. We used different testing methods such as an ergometry, gas analyzing, pulsemetry, and biochemical blood lactate level measuring for checking up physical conditioning. The technique “PHAZAGRAF” was used for assessment of the functional status of players by measuring the ІТ -index of symmetry of T-wave in standard ECG and for testing of vegetative system tonus. We used mathematic methods for data processing. The test of physical readiness showed 11 players with high level capacity to aerobic work with the result of more than 885 seconds. Low result was fixed when the player`s run-time was less than 820 seconds. The findings showed that functional status failures are attendant with ІТ -increasing and lowering of total aerobic readiness. This is revealed in lowering of the maximum oxygen consumption that showed lowering of total aerobic capacity. There was also found that increasing of the standard deviation of ІТ -index could accompany lowering of the running time in the shuttle test. Therewith, vegetative tonus failures in the form of prevailing of sympathetic system activity are not obligatory followed with failures of special or total capacity to work.

  20. 中国象棋经验棋手与新手的知觉差异:来自眼动的证据%The perceptual differences between experienced Chinese chess players and novices:Evidence from eye movement

    Institute of Scientific and Technical Information of China (English)

    王福兴; 侯秀娟; 段朝辉; 刘华山; 李卉

    2016-01-01

    wider saccade span and greater pupil size than novices. Consistent with the previous studies, the experienced chess players fixated more between pieces rather than on the pieces, but the novices allocated more attention on the pieces. Experiment 2 showed that, the experienced players can take advantage of parafoveal processing (16 and 4-piece window) to remember more pieces than the fovea condition (one piece window); but the novices did not show this difference. The eye movement data also showed that the experienced players had wider saccade span than novices when pieces in the parafovea (16 pieces window). Results of experiment 3 showed that the experienced players perceived changed pieces faster and their correct rate were higher than novices. For the changed pieces, the eye movement data indicated that experienced chess players could perceive changes quicker than novices with fovea and parafovea. In conclusion, compared to novices, experienced Chinese chess players can remember and reproduce more chess pieces than novices. Second, experienced players allocate more attention on between pieces based on their chess chunks and templates. Third, experienced Chinese chess players have wider visual span, and can use parafovea to encode information from chess board. Finally, Chinese experienced chess players can perceive changed pieces quickly and more accurately, showing superior perceptual advantage. In sum, consistent with the chess studies, Chinese chess did have expertise superior advantage and superior perceptual encoding advantage.%为探讨中国象棋领域内的专长效应及象棋专长的知觉编码优势,研究采用中国象棋棋局为实验材料,对比了经验棋手和新手在观看象棋棋局时视觉搜索、变化觉察和对棋盘的记忆。实验1呈现真实棋局和随机棋局,要求被试观看5秒后复盘,结果发现经验棋手的复盘正确率高于新手;经验棋手注视棋盘的眼跳幅度和瞳孔直径更大;经验

  1. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    National Research Council Canada - National Science Library

    Yanci, J; Granados, C; Otero, M; Badiola, A; Olasagasti, J; Bidaurrazaga-Letona, I; Iturricastillo, A; Gil, Sm

    ...; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89...

  2. Jet Lag a Drag on Pro Baseball Players

    Science.gov (United States)

    ... 163187.html Jet Lag a Drag on Pro Baseball Players Study found traveling across time zones linked ... might be more than just tiring for pro baseball players: The resulting jet lag may actually harm ...

  3. Action video game players and deaf observers have larger Goldmann visual fields.

    Science.gov (United States)

    Buckley, David; Codina, Charlotte; Bhardwaj, Palvi; Pascalis, Olivier

    2010-03-05

    We used Goldmann kinetic perimetry to compare how training and congenital auditory deprivation may affect the size of the visual field. We measured the ability of action video game players and deaf observers to detect small moving lights at various locations in the central (around 30 degrees from fixation) and peripheral (around 60 degrees ) visual fields. Experiment 1 found that 10 habitual video game players showed significantly larger central and peripheral field areas than 10 controls. In Experiment 2 we found that 13 congenitally deaf observers had significantly larger visual fields than 13 hearing controls for both the peripheral and central fields. Here the greatest differences were found in the lower parts of the fields. Comparison of the two groups showed that whereas VGP players have a more uniform increase in field size in both central and peripheral fields deaf observers show non-uniform increases with greatest increases in lower parts of the visual field.

  4. New Zealand rugby health study: motor cortex excitability in retired elite and community level rugby players.

    Science.gov (United States)

    Lewis, Gwyn N; Hume, Patria A; Stavric, Verna; Brown, Scott R; Taylor, Denise

    2017-01-13

    Rugby union is a high contact sport in which players frequently experience brain injuries. Acute brain injury is associated with altered corticomotor function. However, it is uncertain if long-term exposure to rugby is associated with any alterations in corticomotor function. The aim of the study was to assess measures of corticomotor excitability and inhibition in retired rugby players in comparison to retired non-contact sport players. The design was a cross-sectional study with three groups of retired athletes: elite rugby (n=23), community level rugby (n=28) and non-contact sport control (n=22). Assessments of corticomotor excitability were made using transcranial magnetic stimulation. Resting motor threshold was significantly higher and long-interval intracortical inhibition was greater in the elite rugby group compared to the control group. Participants in the two rugby groups had sustained significantly more concussions than the control group. We provide some evidence of altered corticomotor excitation and inhibition in retired elite rugby players in comparison to retired non-contact sport players. Given the absence of findings in the community rugby group, who had experienced a similar number of concussions, the association with previous brain injury is unclear.

  5. Speckle tracking echocardiographic analysis of left ventricular systolic and diastolic function in young elite rugby players.

    Science.gov (United States)

    Mandigout, Stéphane; Maufrais, Claire; Cornette, Thibault; Alaphilippe, Anne; Daviet, Jean C

    2016-11-01

    Little evidence exists in the literature on the effects of mixed-type training on the left ventricle (LV). This study focused on the effects of training on the morphological and functional characteristics of the left ventricle. This study investigated the effects of training on LV function using Speckle Tracking Imaging (STI) in high-level, young rugby players. This prospective and longitudinal cohort study enrolled ten young controls and 24 young rugby players (13 high-level rugby players; 11 amateur rugby players) were included in the study. Standard Tissue Doppler Imaging Echocardiography and STI were performed in this study before and after the season. LV mass and pulsed wave Doppler inflow recording of the LV, including early and atrial waves, were carried out in 2-3-4 chamber views. We assessed three normal strains, rotation, and torsion in the LV. The main results of this study demonstrated that no differences existed between the three groups in LV functional parameters, the longitudinal circumferential and radial strain indices, and rotation and torsion indices. In the professional group, a significantly higher end-diastolic diameter (Prugby players have normal LV remodeling and normal LV function under resting conditions.

  6. Does Testosterone Modulate Mood States and Physical Performance in Young Basketball Players?

    Science.gov (United States)

    Miloski, Bernardo; Aoki, Marcelo S; de Freitas, Camila G; Schultz de Arruda, Ademir F; de Moraes, Helena S; Drago, Gustavo; Borges, Thiago O; Moreira, Alexandre

    2015-09-01

    This study aimed to examine and compare mood states profile and physical performance during different training phases between 2 groups of adolescent basketball players that were differentiated according to baseline testosterone concentration (T). The basketball players were submitted to an intensified training period (OVL) followed by a tapering period (TP). Twenty-three young male basketball players initiated the study. Experimental criteria data were used to stratify 16 players into high-testosterone (HTC) or low-testosterone (LTC) concentration groups. All the 16 athletes undertook 5 weeks of OVL followed by a 3-week TP. Saliva sampling, Yo-Yo intermittent recovery level 1 (Yo-Yo IRL1) test and the T-test were conducted at the beginning (T1), after OVL (T2), and after TP (T3). A similar increase in internal training load was observed during OVL when compared with TP in both groups (p 0.05); however, LTC displayed a higher score for fatigue (p 0.05). In conclusion, these results suggest that LTC athletes may be more susceptible to changes in mood states during intensified training periods. In addition, data indicate that a periodized training program successfully improved the physical performance (endurance and agility) of young basketball players; however, this improvement was not affected by testosterone level.

  7. Gender differences in the kinematics and ball velocity of overarm throwing in elite team handball players.

    Science.gov (United States)

    Van Den Tillaar, Roland; Cabri, Jan M H

    2012-01-01

    The aim of this study was to investigate the throwing velocity and kinematics of overarm throwing in team handball of elite female and male handball players. Kinematics and ball velocity of a 7 metre-throw in eleven elite male (age 23.6 ± 5.2 yr, body mass 87.0 ± 6.8 kg, height 1.85 ± 0.05 m) and eleven elite female (age 20.3 ± 1.8 yr, body mass 69.9 ± 5.5 kg, height 1.75 ± 0.05 m) team handball players were recorded. The analysis consisted of maximal joint angles, angles at ball release, maximal angular velocities of the joint movements, and maximal linear velocities of the distal endpoints of segments and their timing during the throw. The ball release velocity of the male handball players was significantly higher than the females (21.1 vs. 19.2 m · s(-1); p handball players throw with the same technique. It was concluded that differences in throwing velocity in elite male and female handball players are generally not the result of changes in kinematics in the joint movements.

  8. The Effects of Acoustic Disturbance on Anaerobic Endurance in Female Volleyball Players

    Directory of Open Access Journals (Sweden)

    Sienkiewicz-Dianzenza Edyta

    2015-03-01

    Full Text Available Purpose.The purpose of the study was to assess anaerobic endurance in volleyball players through repeated vertical jump performance under quiet and noisy conditions. Methods. A group of 12 female players aged 19-28 year completed six sets of eight standing vertical jump jumps; jump height and heart rate before and after the protocol were measured in quiet and noisy (fan cheering conditions. Results. Maximum and minimum vertical jump heights were higher and intragroup differences were smaller in noisy than quiet conditions. Conclusions. Vertical jump testing, a measure of physical activity typical of volleyball, is suitable for monitoring training effects. The influence of noise typical during volleyball matches had a positive effect on player performance and anaerobic endurance.

  9. Manipulation of exercise to rest ratio within set duration on physical and technical outcomes during small-sided games in elite youth soccer players.

    Science.gov (United States)

    Christopher, Jack; Beato, Marco; Hulton, Andrew T

    2016-08-01

    Training practices for elite soccer players should take into account specific technical, tactical and physical components. As a consequence of these demands small-sided games (SSGs) have become a popular conditioning tool that replicate the demands encountered during match play. The aim of this investigation was to examine how the manipulation of exercise to rest ratio, within the same overall duration, affected both physical and technical outcomes during SSGs in elite youth soccer. Twelve elite youth soccer players participated in three variations of eight minute 6v6 SSGs. The three variations included eight minutes continuous, 2×4min and 4×2min. Players perceived the continuous 8min block as the hardest (4.5±1.5AU), followed by the 2×4min (3.9±1.4AU) and the 4×2min (3.3±1.4AU), although no difference in mean HR or physical measures via GPS analysis between SSGs was evident. From the technical perspective, only goals scored reached significance, with post hoc analysis identifying the number of goals scored were significantly higher during the 4×2min and 2×4min SSGs compared to 8min continuous block. These results show that subjective ratings of exertion differed between conditions, but only minor technical manipulations were observed by adjusting work to rest ratios, with no significant effect on physical performance.

  10. Effects of sports injury prevention training on the biomechanical risk factors of anterior cruciate ligament injury in high school female basketball players.

    Science.gov (United States)

    Lim, Bee-Oh; Lee, Yong Seuk; Kim, Jin Goo; An, Keun Ok; Yoo, Jin; Kwon, Young Hoo

    2009-09-01

    Female athletes have a higher risk of anterior cruciate ligament injury than their male counterparts who play at similar levels in sports involving pivoting and landing. The competitive female basketball players who participated in a sports injury prevention training program would show better muscle strength and flexibility and improved biomechanical properties associated with anterior cruciate ligament injury than during the pretraining period and than posttraining parameters in a control group. Controlled laboratory study. A total of 22 high school female basketball players were recruited and randomly divided into 2 groups (the experimental group and the control group, 11 participants each). The experimental group was instructed in the 6 parts of the sports injury prevention training program and performed it during the first 20 minutes of team practice for the next 8 weeks, while the control group performed their regular training program. Both groups were tested with a rebound-jump task before and after the 8-week period. A total of 21 reflective markers were placed in preassigned positions. In this controlled laboratory study, a 2-way analysis of variance (2 x 2) experimental design was used for the statistical analysis (P sports injury prevention training program improved the strength and flexibility of the competitive female basketball players tested and biomechanical properties associated with anterior cruciate ligament injury as compared with pretraining parameters and with posttraining parameters in the control group. This injury prevention program could potentially modify the flexibility, strength, and biomechanical properties associated with ACL injury and lower the athlete's risk for injury.

  11. Radiographic findings of femoroacetabular impingement in capoeira players.

    Science.gov (United States)

    Mariconda, Massimo; Cozzolino, Andrea; Di Pietto, Francesco; Ribas, Manuel; Bellotti, Vittorio; Soldati, Alessandra

    2014-04-01

    Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art. Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head-neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated. Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head-neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade. High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira.

  12. Training Patterns of Wheelchair Basketball Players in Turkey

    Science.gov (United States)

    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…

  13. Automatic player detection and identification for sports entertainment applications

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khattak, Shadid; Hasan, Laiq; Khan, Samee U.

    2014-01-01

    In this paper, we develop an augmented reality sports broadcasting application for automatic detection, recognition of players during play, followed by display of personal information of players. The proposed application can be divided into four major steps. In first step, each player in the image i

  14. Synthetic Players: A Quest for Artificial Intelligence in Computer Games

    Directory of Open Access Journals (Sweden)

    Jouni Smed

    2005-03-01

    Full Text Available Synthetic players are the computer-controlled actors in a computer game. In this paper, we describe both the implementation issues and the behavioural expectations related to synthetic players. We recognize the role of synthetic players by analysing the components of games in general and computer games in particular.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  17. Understanding the Mismatch Between Coaches' and Players' Perceptions of Exertion

    NARCIS (Netherlands)

    Brink, Michel S.; Kersten, Anna W.; Frencken, Wouter G. P.

    2017-01-01

    A mismatch between the training exertion intended by a coach and the exertion perceived by players is well established in sports. However, it is unknown whether coaches can accurately observe exertion of individual players during training. Furthermore, the discrepancy in coaches' and players' percep

  18. High School Rugby Players' Perception of Coaching Effectiveness

    Science.gov (United States)

    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…

  19. Preferred Leadership Behaviours of Male and Female Badminton Players

    OpenAIRE

    Rajkumar S HARMA

    2015-01-01

    Pr eferences for specific coaching behaviours of male and female Badminton players were measured by the modified and revised Leadership Scale for Sport. Eighty two (Males=61, Females=21) badminton players were selected from amongst the players representing th eir respective university teams in East - zone Inter - university Badminton (Men/Women) tournaments held at Bilaspur (CG). The present investigation noted ...

  20. Automatic player detection and identification for sports entertainment applications

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khattak, Shadid; Hasan, Laiq; Khan, Samee U.

    In this paper, we develop an augmented reality sports broadcasting application for automatic detection, recognition of players during play, followed by display of personal information of players. The proposed application can be divided into four major steps. In first step, each player in the image

  1. Dynamic Difficulty Balancing for Cautious Players and Risk Takers

    Directory of Open Access Journals (Sweden)

    Guy Hawkins

    2012-01-01

    Full Text Available Dynamic balancing of game difficulty can help cater for different levels of ability in players. However, performance in some game tasks depends on not only the player's ability but also their desire to take risk. Taking or avoiding risk can offer players its own reward in a game situation. Furthermore, a game designer may want to adjust the mechanics differently for a risky, high ability player, as opposed to a risky, low ability player. In this work, we describe a novel modelling technique known as particle filtering which can be used to model various levels of player ability while also considering the player's risk profile. We demonstrate this technique by developing a game challenge where players are required to make a decision between a number of possible alternatives where only a single alternative is correct. Risky players respond faster but with more likelihood of failure. Cautious players wait longer for more evidence, increasing their likelihood of success, but at the expense of game time. By gathering empirical data for the player's response time and accuracy, we develop particle filter models. These models can then be used in real-time to categorise players into different ability and risk-taking levels.

  2. Understanding the Mismatch Between Coaches' and Players' Perceptions of Exertion

    NARCIS (Netherlands)

    Brink, Michel S; Kersten, Anna W; Frencken, Wouter G

    2016-01-01

    A mismatch between the intended training exertion by the coach and the perceived exertion by players is well established in sports. However, it is unknown if coaches are able to accurately observe exertion of individual players during training. Furthermore, the discrepancy in coaches' and players' p

  3. 立足“高等性”、凸显“职业性”是高职院校校园文化建设的核心--以顺德职业技术学院为例%Based on the"Higher Attribute",Showing the"Vocational Attribute"the Core of the Construction of Campus Culture in Higher Vocational Colleges---Taking Shunde Polytechnic as an example

    Institute of Scientific and Technical Information of China (English)

    强金国; 胡蓉

    2014-01-01

    Higher vocational campus culture construction possesses " higher attribute " and " vocational attribute ", during its construction, we should keep a foothold on " higher attribute ",promote its gradation and taste, show " vocational attribute ", highlight its role and target, which aims to construct favorable atmosphere for cultivating higher quality skilled personnel. In this aspect, Shunde Polytechnic carried out precious exploration and practice.%高职校园文化兼具高等性和职业性特征。建设中,要立足“高等性”,提升其层次和品位;凸显“职业性”,突出其角色和面向,为培养高素质技能型人才营造良好氛围。这方面,顺德职院开展了可贵的探索和实践。

  4. Do Basketball Players Have a High Risk of Pulmonary Embolism? A Scoping Review.

    Science.gov (United States)

    Casals, Martí; Martínez, Jose A; Caylà, Joan A; Martín, Vicente

    2016-03-01

    Pulmonary embolism (PE) is a serious preventable disease that requires urgent care. In recent years, there have been several reports in the media about basketball players experiencing PE. The aim of the present study was to assess whether there is a need for in-depth studies to determine whether basketball players constitute a group particularly at risk of PE and to describe some hypotheses to be investigated. We reviewed original articles about PE among professional and amateur basketball players in the scientific literature (PubMed) and the Internet (Google search) for the seasons 2010-2011 to 2014-2015, both of which were included. We used search strategies that included some combination of PE-related terms. Rates of PE were calculated and were compared with those obtained from other studies. Of the 15 cases detected, the majority were men (66.7%), mean ages being 28.8 yr among males and 20.4 yr among females. We focused on six cases which, were detected among National Basketball Association and Asociación de Clubes de Baloncesto basketball players, resulting in an average incidence of 1.27 and 2.06 cases per 1000 players per year in the National Basketball Association and Asociación de Clubes de Baloncesto, respectively. This incidence is much higher than that observed in general population studies for the same age group. Basketball players seem to have a higher risk of PE than their peers from the general population. More studies are needed to confirm these findings and identify factors predisposing them to PE to contribute to its prevention.

  5. Future Achievements, Passion and Motivation in the Transition from Junior-to-Senior Sport in Spanish Young Elite Soccer Players.

    Science.gov (United States)

    Chamorro, José L; Torregrosa, Miquel; Sánchez Oliva, David; García Calvo, Tomás; León, Benito

    2016-10-20

    Within the context of the transition from junior-to-senior sport, this study aims in first place to explore differences in young Spanish elite soccer players based on the importance given to getting different achievements in their future (including sport, studies and private life) and, in second place, to explore differences among those players in levels of passion, motivation and basic psychological need. 478 elite youth soccer filled out a questionnaire based on the presented theoretical models. A cluster analysis shows a sport oriented group (N = 98) only interested in becoming a professional, a life spheres balance group (N = 288) characterized by balancing the importance of achievements in the sport sphere, as well as in education and a private life and a group (N = 91) only interested in private life achievements. The life spheres balance group shows higher levels of harmonious passion (η2 = .06, F(2, 475) = 9.990, p motivation (η2 = .10, F(2, 475) = 13.597, p sport oriented group as well as lower levels of amotivation (η2 = .04, F(2, 475) = 6.665, p motivation, to cope with the transition to professional soccer.

  6. Mood states of soccer players in the english leagues: reflections of an increasing workload

    Directory of Open Access Journals (Sweden)

    R Thatcher

    2010-06-01

    Full Text Available The aim of this investigation was to assess whether the demands of the modern English competitive soccer season would be reflected in the mood states of professional soccer players. Sixty-nine male participants either activity competing in English soccer leagues or resident in England were recruited and grouped accordingly as professional soccer players, university level soccer players, Sunday league soccer players, or non-sporting controls. On three separate occasions; at the beginning, at the middle, and finally towards the end of the English soccer season, participants completed both the Profile of Mood States (POMS questionnaire as well as a questionnaire related to their teams’ performance in addition to their perceived life stress. Results showed the POMS scores to differ over the season in relation to the groups’ standard of competition. ANOVAs demonstrated this pattern to be significant for the dependent measures of tension, depression, and confusion with significant group by time interactions (95% level of confidence. At the outset of the season professionals had the most positive POMS profile, however, as the season progressed they showed the greatest change towards a negative profile. These results indicate that English soccer is placing professional players at a predisposition of demonstrating POMS commensurate with negative adaptation to training, having important implications for their long-term performance and health.

  7. Player Experiences and Behaviors in a Multiplayer Game: designing game rules to change interdependent behavior

    Directory of Open Access Journals (Sweden)

    Niko Vegt

    2016-12-01

    Full Text Available Serious gaming is used as a means for improving organizational teamwork, yet little is known about the effect of individual game elements constituting serious games. This paper presents a game design experiment aimed at generating knowledge on designing game elements for teamwork. In previous work, we suggested that interaction- and goal-driven rules could guide interdependence and teamwork strategies. Based on this finding, for the present experiment we developed two versions of multiplayer Breakout, varying in rule-sets, designed to elicit player strategies of either dependent competition or dependent cooperation. Results showed that the two rule-sets could generate distinct reported player experiences and observable distinct player behaviors that could be further discriminated into four patterns: expected patterns of helping and ignoring, and unexpected patterns of agreeing and obstructing. Classic game theory was applied to understand the four behavior patterns and made us conclude that goal-driven rules steered players towards competition and cooperation. Interaction rules, in contrast, mainly stimulated dependent competitive behavior, e.g. obstructing each other. Since different types of rules thus led to different player behavior, discriminating in game design between interaction- and goal-driven rules seems relevant. Moreover, our research showed that game theory proved to be useful for understanding goal-driven rules.

  8. Motivational Traits of Elite Young Soccer Players

    Science.gov (United States)

    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…

  9. Soccer Skill Development in Talented Players

    NARCIS (Netherlands)

    Huijgen, B. C. H.; Elferink-Gemser, M. T.; Ali, A.; Visscher, C.

    2013-01-01

    The aim of the study was to gain insight into the development of soccer-specific skills and whether differences between talented players exist on the Loughborough Soccer Passing Test (LSPT). Two scores were derived from the LSPT: 1) execution time: time to complete 16 passes (speed) and 2) skill per

  10. Telecom Restructuring Shows Few Winners

    Institute of Scientific and Technical Information of China (English)

    BRADLEY GARDNER

    2008-01-01

    @@ The long-awaited restructuring of the Chinese telecom industry was announced on lune 2,and while China Unicorn (中国联通) got the best deal of the major players,analysts agreed that neither Unicorn nor China Telecom (中国电信) got enough out of the restructuring to challenge the dominant position of market leader China Mobile (中国移动).

  11. Football players, asset management & the unexploited potential of enhanced player engagement in football management & marketing

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2014-01-01

    This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives.......This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives....

  12. Football players, asset management & the unexploited potential of enhanced player engagement in football management & marketing

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2016-01-01

    This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives.......This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives....

  13. Analysis of Experts’ Quantitative Assessment of Adolescent Basketball Players and the Role of Anthropometric and Physiological Attributes

    Directory of Open Access Journals (Sweden)

    Štrumbelj Erik

    2014-10-01

    Full Text Available In this paper, we investigated two questions: (1 can measurements of anthropometric and physiological attributes substitute for expert assessment of adolescent basketball players, and (2 how much does the quantitative assessment of a player vary among experts? The first question is relevant to the potential simplification of the player selection process. The second question pertains directly to the validity of expert quantitative assessment. Our research was based on data from 148 U14 female and male basketball players. For each player, an array of anthropometric and physiological attributes was recorded, including body height, body mass, BMI, and several motor skill tests. Furthermore, each player's current ability and potential ability were quantitatively evaluated by two different experts from a group of seven experts. Analysis of the recorded data showed that the anthropometric and physiological attributes explained between 15% and 40% of the variance in experts’ scores. The primary predictive attributes were speed and agility (for predicting current ability and body height and growth potential (for predicting potential ability. We concluded that these attributes were not sufficiently informative to act as a substitute for expert assessment of the players’ current or potential ability. There is substantial variability in different experts' scores of the same player’s ability. However, the differences between experts are mostly in scale, and the relationships between experts’ scores are monotonic. That is, different experts rank players on ability very similarly, but their scores are not well calibrated.

  14. Optimal Decision Rules in Repeated Games Where Players Infer an Opponent’s Mind via Simplified Belief Calculation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Nakamura

    2016-07-01

    Full Text Available In strategic situations, humans infer the state of mind of others, e.g., emotions or intentions, adapting their behavior appropriately. Nonetheless, evolutionary studies of cooperation typically focus only on reaction norms, e.g., tit for tat, whereby individuals make their next decisions by only considering the observed outcome rather than focusing on their opponent’s state of mind. In this paper, we analyze repeated two-player games in which players explicitly infer their opponent’s unobservable state of mind. Using Markov decision processes, we investigate optimal decision rules and their performance in cooperation. The state-of-mind inference requires Bayesian belief calculations, which is computationally intensive. We therefore study two models in which players simplify these belief calculations. In Model 1, players adopt a heuristic to approximately infer their opponent’s state of mind, whereas in Model 2, players use information regarding their opponent’s previous state of mind, obtained from external evidence, e.g., emotional signals. We show that players in both models reach almost optimal behavior through commitment-like decision rules by which players are committed to selecting the same action regardless of their opponent’s behavior. These commitment-like decision rules can enhance or reduce cooperation depending on the opponent’s strategy.

  15. Performance and Metabolic Demand of a New Repeated-Sprint Ability Test in Basketball Players: Does the Number of Changes of Direction Matter?

    Science.gov (United States)

    Zagatto, Alessandro M; Ardigò, Luca P; Barbieri, Fabio A; Milioni, Fabio; Dello Iacono, Antonio; Camargo, Bruno H F; Padulo, Johnny

    2017-09-01

    Zagatto, AM, Ardigò, LP, Barbieri, FA, Milioni, F, Dello Iacono, A, Camargo, BHF, and Padulo, J. Performance and metabolic demand of a new repeated-sprint ability test in basketball players: does the number of changes of direction matter? J Strength Cond Res 31(9): 2438-2446, 2017-This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 × 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (V[Combining Dot Above]O2) and posttest blood lactate concentration [La] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p sprint times and higher peak speeds. Over sprints, the tests did not differ from each other in terms of V[Combining Dot Above]O2 (p > 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands.

  16. Influence of the mechanical properties of third-generation artificial turf systems on soccer players' physiological and physical performance and their perceptions.

    Directory of Open Access Journals (Sweden)

    Javier Sánchez-Sánchez

    Full Text Available The aim of this research was to evaluate the influence of the mechanical properties of artificial turf systems on soccer players' performance. A battery of perceptive physiological and physical tests were developed on four different structural systems of artificial turf (System 1: Compacted gravel sub-base without elastic layer; System 2: Compacted gravel sub-base with elastic layer; System 3: Asphalt sub-base without elastic layer; System 4: Asphalt sub-base with elastic layer. The sample was composed of 18 soccer players (22.44±1.72 years who typically train and compete on artificial turf. The artificial turf system with less rotational traction (S3 showed higher total time in the Repeated Sprint Ability test in comparison to the systems with intermediate values (49.46±1.75 s vs 47.55±1.82 s (S1 and 47.85±1.59 s (S2; p0.05. The physiological load was similar in all four artificial turf systems. However, players felt more comfortable on the harder and more rigid system (S4; visual analogue scale = 70.83±14.28 than on the softer artificial turf system (S2; visual analogue scale = 54.24±19.63. The lineal regression analysis revealed a significant influence of the mechanical properties of the surface of 16.5%, 15.8% and 7.1% on the mean time of the sprint, the best sprint time and the maximum mean speed in the RSA test respectively. Results suggest a mechanical heterogeneity between the systems of artificial turf which generate differences in the physical performance and in the soccer players' perceptions.

  17. Efects of the physical training, based in ergospyrometric evaluation, in the aerobic capacity of volley players – physical training in volley players

    Directory of Open Access Journals (Sweden)

    Newton Nunes

    2008-06-01

    Full Text Available The prescription of the exercise training intensity based on ventilatory thresholds, determined by ergoespirometric evaluations, has been very useful for athletes. The aim of the present study was to verify the effect of a short period of exercise training, based on the ventilatory thresholds on physical capacity of volleyball players. Six male volleyball players (25±4 years were studied during the competitive phase of the State Championship. The players were submitted to two maximal ergoespirometric evaluations on the treadmill with a three-month interval. In this period, the aerobic training was performed with an intensity between the anaerobic threshold and the respiratory compensation point, and the anaerobic training on an intensity above the respiratory compensation point. Exercise training caused a significant increase in maximal oxygen uptake (48.6±3.0 vs. 51.0±3.0 ml.kg-1.min-1, p < 0.05, but without significant alteration in maximal power, maximal heart rate and maximal ventilation. The values of oxygen uptake and heart rate, in which the ventilatory thresholds were achieved, tended to be higher after exercise training. In conclusion, a short period of three months of exercise training based on the ventilatory thresholds is effective in increasing the maximal oxygen uptake in volleyball players and tends to increase the ventilatory thresholds.

  18. Dynamic Visual Acuity Training in Cricket Players

    Directory of Open Access Journals (Sweden)

    Renee Edgar, B.Optom

    2015-04-01

    Full Text Available Background: Dynamic visual acuity (DVA is the ability of an observer to correctly identify details of a moving target and is considered to be important for tasks like driving. Dynamic Visual Acuity is better in athletes involved in sports such as basketball and baseball; however, no previous studies have considered the sport of cricket. We conducted a study to determine whether there was any difference in DVA between cricket and non-cricket players. Method: Dynamic visual acuity was measured by asking subjects to identify the orientation of the gap of a moving Landolt C target as a four-alternative forced-choice task. The Landolt C targets had confusion bars surrounding them. The participants in the study were tested twice with a break of seven weeks. In between the two measurements, participants underwent two training sessions (similar to the testing sessions, each three weeks apart. Results: The initial mean DVA for cricket players was 107.7 deg/sec, and the mean DVA for non-cricket players was 105.5 deg/sec, with a target size of 6/15. The subjects who participated in training (cricketers and non-cricketers improved in DVA by 41 deg/sec in contrast to the improvement in the non-training subjects of 18 deg/sec (p=0.0032. The cricketers who participated in the training improved in DVA by 44 deg/sec, whereas the cricketers who did not participate in the training improved by 19 deg/sec (p=0.0167. Conclusions: We found no significant difference in initial DVA between the cricket players and the non-cricket players. The training resulted in an extremely significant improvement in DVA performance by both the cricketers and non-cricketers.

  19. Identification of the auditorium with successful tennis players

    Directory of Open Access Journals (Sweden)

    Dugalić Sretenka

    2015-01-01

    Full Text Available This paper presents the results of interviewing a sample of 229 respondents from Belgrade who are of a different gender, age and employment status. The study is a continuation of an earlier pilot study, with the help of identical questionnaires conducted through the Internet (Google form. The aim was to investigate the affinity of respondents concerning the business from which celebrities come, and to identify the similarities and differences in attitudes from which the promotional power of athletes may be evaluated. The study included a set of questions, some of which are presented in this paper: 1/ to what extent sport and sporting celebrities influence the decision of the respondents; 2/ assessing the similarity of equipment that respondents utilized if they play tennis (amateur, recreational or professional, with the equipment of their favorite players. During the answer to the second question, the respondents kept in mind certain players. The answers were analyzed by means of descriptive analysis. These studies show that a promotional power exists between the widest audiences of athletes. The study should encourage greater proficiency in the evaluation of sporting talent as scarce human resources, which, although burdened with costs, often remains unvalued, in terms of the declining nature of their athletic performance during their career. The research results show: 1 / respondents of different age and genders prefer sport as an activity from which celebrities come; 2 / 81.25% of those who play tennis identified using the brand of equipment as their favorite players, and the highest agreement in attitudes has been achieved with the variables of gender and employment. The study provides an answer to the question of which target group, within a promotional capacity, results in a conversion of sport results, and contributes to the strengthening of national identity through loyalty to proven sporting values.

  20. Sleep-apnea risk and subclinical atherosclerosis in early-middle-aged retired National Football League players

    Science.gov (United States)

    Luyster, Faith S; Dunn, Reginald E; Lauderdale, Diane S; Carnethon, Mercedes R; Tucker, Andrew M; Vogel, Robert A; Lincoln, Andrew E; Knutson, Kristen L; Pellman, Elliot J; Strollo, Patrick J

    2017-01-01

    Purpose Limited data from former National Football League (NFL) players suggest that obstructive sleep apnea (OSA) may be highly prevalent after retirement. It remains unclear whether the high prevalence of OSA in retired players is comparable to nonathletes. This retrospective analysis compared sleep apnea (SA) risk in retired NFL players to a community cohort (CARDIA Sleep study), and examined associations between SA risk and cardiovascular risk factors, including subclinical atherosclerosis. Materials and methods Retired NFL players (n=122) were matched to CARDIA Sleep participants by age ±2 years (range 37–55 years), body mass index ±2 kg/m2, race, and male sex. Participants underwent electron-beam computed tomography to measure coronary artery calcium (CAC) and completed the Berlin Questionnaire to determine SA risk. The presence of CAC was defined as an Agatston score >0. Results Retired NFL players had a greater prevalence of high SA risk than the matched CARDIA Sleep participants (27% vs 11.5%, P=0.002). Compared to the CARDIA Sleep participants, retired players were less likely to smoke, and had higher blood pressure, lower fasting glucose levels, and higher cholesterol levels. However, there was no difference in the prevalence of detectable CAC (30% vs 30%, P=1). In both players and the community cohort, SA risk was not significantly associated with CAC after controlling for age, race, and body mass index. Conclusion Retired NFL players have a greater prevalence of high SA risk but similar prevalence of CAC compared with a well-matched community cohort. PMID:28260958

  1. Evaluating Australian football league player contributions using interactive network simulation.

    Science.gov (United States)

    Sargent, Jonathan; Bedford, Anthony

    2013-01-01

    This paper focuses on the contribution of Australian Football League (AFL) players to their team's on-field network by simulating player interactions within a chosen team list and estimating the net effect on final score margin. A Visual Basic computer program was written, firstly, to isolate the effective interactions between players from a particular team in all 2011 season matches and, secondly, to generate a symmetric interaction matrix for each match. Negative binomial distributions were fitted to each player pairing in the Geelong Football Club for the 2011 season, enabling an interactive match simulation model given the 22 chosen players. Dynamic player ratings were calculated from the simulated network using eigenvector centrality, a method that recognises and rewards interactions with more prominent players in the team network. The centrality ratings were recorded after every network simulation and then applied in final score margin predictions so that each player's match contribution-and, hence, an optimal team-could be estimated. The paper ultimately demonstrates that the presence of highly rated players, such as Geelong's Jimmy Bartel, provides the most utility within a simulated team network. It is anticipated that these findings will facilitate optimal AFL team selection and player substitutions, which are key areas of interest to coaches. Network simulations are also attractive for use within betting markets, specifically to provide information on the likelihood of a chosen AFL team list "covering the line ". Key pointsA simulated interaction matrix for Australian Rules football players is proposedThe simulations were carried out by fitting unique negative binomial distributions to each player pairing in a sideEigenvector centrality was calculated for each player in a simulated matrix, then for the teamThe team centrality measure adequately predicted the team's winning marginA player's net effect on margin could hence be estimated by replacing him in

  2. Comparison of game addiction prevalence rates between MMOFPS players and MMORPG players. A case of EVE Online and DUST 514

    OpenAIRE

    Guðmundur Helgason 1990; Ólafur Hrafn Steinarsson 1990

    2013-01-01

    The main aim of this research project was to explore the prevalence of gaming addiction among players of different genres of video games. Additionally, the potential risks of structural characteristics of games were also examined. The sample consisted of 445 participants, aged 13 to 67, with 96.6% being male and 3.4% being female. To assess video game addiction the short version of the GAS-7 (Lemmens et al., 2009) was employed. The results showed that no significant differences were found bet...

  3. Feng Yun-A higher Class

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    TO this Weiqi player, rising to a higher class is like climbing a mountain. Hangzhou city is a lucky place for Feng Yun for it is where she won her first national championship 10 years ago. Commonly known by it's Japanese name "Go", Weiqi is actually of Chinese origin and is a game of

  4. [Comparison of somatotype differences of soccer and handball players based on the methods of German and Anglo-American schools of constitutional biology].

    Science.gov (United States)

    Raschka, Christoph; Wolthausen, Christina

    2007-09-01

    39 soccer players of the third division as well as 22 handball players of the second division and 17 handball fourth division players (average age 24 years) were examined kinanthropometrically. The sports anthropological evaluations were made according to the methods of Parnell (1958), Heath & Carter (1967), Conrad (1963), Knussmann (1961a, 1961b) as well as Tittel & Wutscherk (1972). Regarding the proportionality, proportion figures and phantom stratagem were used. In the typology of Conrad (1963) above all the high hyperplasia values of the handball players stand out. According to the typognosis of Knussmann (1961a, 1961b) the handball and soccer players are to be classified as leptomorph. The tendency to the macrosomia pole is to be recognized for the handball players. In the somatochart of Parnell (1958) soccer and handball players are placed in the mesomorph ectomorph sixth. The group differences are highly significant for the endomorphy. In the somatogramm of Heath & Carter (1967) both ballplayer collectives are settled in the ectomorph mesomorph area. The group differences are here for the endomorphy and mesomorphy highly significant, for the ectomorphy significant. The proportional fat portion (calipermetry) is high-significantly lower for the soccer players with 6.6 +/- 1.6% than for the handball players (8.4 +/- 2.5%). All height and longitudinal dimensions as well as the circumferences with exception of the thigh girth were for the larger handball players (body height: 189.1 +/- 7.9 cm) very to highly significantly higher than for the smaller soccer players (body height: 178.6 +/- 5.8 cm), whereby no important proportional differences were registered.

  5. Perfectionism and sport-specific engagement in elite youth soccer players.

    Science.gov (United States)

    Larkin, Paul; O'Connor, Donna; Williams, A Mark

    2016-07-01

    It is acknowledged that the time invested in sport-specific activities contributes to higher levels of performance. However, there is limited understanding of the potential impact of personality traits, such as perfectionism, on engagement in sport-specific activities. In the current study, we examine whether elite youth soccer players who demonstrate higher and lower levels of perfectionistic strivings tendencies can be differentiated based on their sport-specific engagement. The Sport Multidimensional Perfectionism Scale 2 and an adapted Player History Questionnaire were completed by 419 elite youth male soccer players competing at the Australian age-related national youth championships (under 13, n = 133; under 14, n = 166; under 15, n = 120). A quartile split approach was used to separate higher (n = 100) and lower (n = 107) perfectionistic strivings groups. Findings revealed the higher perfectionistic strivings group accumulated more time in sport-specific activities, including coach-led practice, individual practice, peer-led play and indirect involvement in soccer when compared to individuals with lower perfectionistic strivings tendencies. Descriptive analysis indicates this equates to approximately 159 h a year (i.e. 17 h coach-led practice, 22 h individual practice, 60 h of peer-led play and 60 h of indirect involvement) more than the lower perfectionistic strivings group. In summary, the results suggest players with varying levels of perfectionistic strivings may be differentiated based on their engagement in soccer-specific activity in a sample of elite youth players in Australia, and suggests that perfectionistic strivings may have an adaptive influence on sport-specific engagement.

  6. JUMP LANDING CHARACTERISTICS IN ELITE SOCCER PLAYERS WITH CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    Jesús Cámara

    2013-04-01

    Full Text Available The aim of the present study was to analyse the parameters that characterize the vertical ground reaction force during the landing phase of a jump, and to determine the relationship among these parameters in elite soccer players with cerebral palsy (CP. Thirteen male members of the Spanish national soccer team for people with CP (mean age: 27.1 ± 4.7 years volunteered for the study. Each participant performed three counter movement jumps. The characteristics of the first peak of the vertical ground reaction force during the landing phase of a jump, which corresponds to the forefoot contact with the ground, were similar to the results obtained in previous studies. However, a higher magnitude of rearfoot contact with the ground (F2 was observed in participants with CP than in participants without CP. Furthermore, a significant correlation between F2 magnitude and the elapsed time until its production (T2 was not observed (r = -0.474 for p = 0.102. This result implies that a landing technique based on a delay in the production of F2 might not be effective to reduce its magnitude, contrary to what has been observed in participants without CP. The absence of a significant correlation between these two parameters in the present study, and the high magnitude of F2, suggest that elite soccer players with CP should use footwear with proper cushioning characteristics.

  7. Oxidative stress and total antioxidant capacity in handball players

    Directory of Open Access Journals (Sweden)

    Gholamreza Sharifi

    2014-01-01

    Full Text Available Background: Exercise training increases oxygen consumption, which was associated with the high generation of reactive oxygen species and markers of lipid peroxidation in the blood. The aim of this study was to assess the responses of total antioxidant capacity (TAC, biomarker of oxidative stress and erythrocyte, leukocyte and hematocrit (Hct levels in plasma in athlete girls (handball players and non-athlete girls. Materials and Methods: We evaluated two groups, which known as athlete and non-athlete women and they were similar in anthropometric characteristics. The athletic women engaged in the regular handball training 3 times a week for at least 6 months. However, non-athletic women didn′t have any regular activity over the last 6 months. Each subject referred to the lab and after 12 h fasting, the blood samples were taken for measuring all variables. Independent sample t-tests were used to identify the differences. Result: Significant differences were observed in malondehyde (P = 0.00, red blood (P = 0.00 cell and hemoglobin (P = 0.00. However, other evaluated factors such as of TAC, white blood cell, Hct and the mean corpuscular volume were higher in athletes than in non-athletes, but statistical significant differences weren′t seen in these variables between two groups. Conclusion: Regular exercise training for handball players may increase the activity of antioxidant enzymes and blood cells and reduces oxidant production.

  8. The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players

    Science.gov (United States)

    Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

    2015-01-01

    The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p training programs could provide additional benefits to traditional strength training protocols to improve muscular imbalances in post-adolescent soccer players. PMID:26630271

  9. Anthropometric, Physical, and Age Differences by the Player Position and the Performance Level in Volleyball

    Science.gov (United States)

    Palao, José M.; Manzanares, Policarpo; Valadés, David

    2014-01-01

    The purpose of this paper was to study the ranges in height, weight, age, spike reach, and block reach of volleyball players in relation to the player position and the level of their respective teams in peak performance. The analysed sample included 1454 male and 1452 female players who participated in the volleyball competitions of the Olympic Games and World Championships in the 2000–2012 period. A descriptive, correlational, and longitudinal design was used. The variables studied were: the player position, body height, weight, body mass index, spike reach, block reach, age, and team level. The results show differences between body height, spike and block reaches, and the age of the players by their position. These differences are related to the needs of the different positions with regard to the actions they execute. Middle-blockers, outside-hitters, and opposites have the characteristics that are most suitable for blocking and spiking, and the setters and liberos appear to have characteristics conducive to setting and receiving as well as digging, respectively. The differences found in the studied variables with regard to the playing position are related to players’ needs regarding the actions they perform. Player’s age was a variable that differentiated first teams at this level of competition for males, and physical capacities (body height, weight, spike reach, and block reach) were variables that differentiated first teams at this level of competition for females. PMID:25713683

  10. OURNAMENT STRUCTURE AND SUCCESS OF PLAYERS BASED ON LOCATION IN MEN'S PROFESSIONAL TENNIS

    Directory of Open Access Journals (Sweden)

    Ales Filipcic

    2013-06-01

    Full Text Available This article discusses the relationship between success of professional male tennis players according to the country and world region from which they originate and the professional tournament structure in men's tennis in that world region and country. The success of a country or world region was defined by the number of players in the top 300 ATP rankings and was calculated for seven time periods between 1975 and 2008. The results showed the correlations between the total number of top 300 ranked players, the total number of tournaments, and the annual tournament prize money of the specific country. The correlations were nearly perfect in the 1975-1990 period (r = 0.93-0.95; p < 0.01 but only high in the 2005-2008 period (r = 0.60-0.64; p < 0.01, suggesting that the association between the number of top 300 ranked tennis players and professional tournaments, while still significant, is in decline. These data should inform the policy and investment decisions of regional and national federations, particularly as they relate to domestic professional tennis tournament structures and to explore opportunities to include professional tournaments of neighbour countries in their player's development programs

  11. Sport injuries aligned to peak height velocity in talented pubertal soccer players.

    Science.gov (United States)

    van der Sluis, A; Elferink-Gemser, M T; Coelho-e-Silva, M J; Nijboer, J A; Brink, M S; Visscher, C

    2014-04-01

    In young athletes, demands of sports are superimposed on normal growth and maturation. It has been suggested that this causes a temporarily increased vulnerability for injuries. We followed 26 talented soccer players (mean age 11.9±0.84 years) longitudinally for 3 years around their adolescent growth spurt, called Peak Height Velocity, to identify differences in number of traumatic and overuse injuries and days missed due to injuries. Peak Height Velocity was calculated according to the Maturity Offset Protocol. The number of injuries was calculated for each player per year. A repeated measurement analysis showed that athletes had significantly more traumatic injuries in the year of Peak Height Velocity (1.41) than in the year before Peak Height Velocity (0.81). A moderate effect size of 0.42 was found for the difference in number of overuse injuries per player per year before (0.81) and after Peak Height Velocity (1.41), respectively. Finally, a moderate effect size of 0.55 was found for difference between days missed due to injuries before (7.27 days per player per year) and during Peak Height Velocity (15.69 days per player per year). Adolescent growth spurt seems to result in increased vulnerability for traumatic injuries. Afterwards athletes seem to be susceptible to overuse injuries.

  12. RELATIONS BETWEEN DOMESTIC AND FOREIGN BASKETBALL PLAYER IN BASKETBALL T EAM

    Directory of Open Access Journals (Sweden)

    Besnik Morina

    2012-09-01

    Full Text Available The goal of this research based on socio-metric test results, to show the relations between domestic basketball players and visitors basketball players within Trepça basketball Club from Mitrovica. The research has been made based on a sample of Kosovo Superleague in basketball, in fact with the basketball players of Trepça from Mitrovica during 2008/09. Based on this sample 16 basketball players aged 19 to 30 have been included. Relevant data about this research have been collected through a questionnaire (Paranosic and Lazareviq, 1975. Based on the socio-metric results we can come to the conclusion that there is a different socio-metric structure in the team. There are individuals who were different from the others in the team based on positive evaluation (+ so-called “star” in the team, who were the domestic players as well as individuals who were negatively (- evaluated, so-called “the negative stars”, who represent a weaker relation in the team, and the were the visitors.

  13. Assessment of cervical range of motion, cervical core strength and scapular dyskinesia in violin players.

    Science.gov (United States)

    Tawde, Pooja; Dabadghav, Rachana; Bedekar, Nilima; Shyam, Ashok; Sancheti, Parag

    2016-12-01

    Playing the violin can lead to asymmetric postures which can affect the cervical range of motion, cervical core strength and scapular stability. The objective of the study was to assess the cervical range of motion, cervical core strength and scapular dyskinesia in violin players and non-players of the same age group. An inclinometer was used to assess the cervical range of motion, pressure biofeedback was used to assess cervical core strength and scapular dyskinesia was also assessed in 30 professional violin players (18-40 years) compared with 30 age-matched non-players. Analysis was done using an unpaired t test. Significant change was seen with respect to extension (p = 0.051), cervical core strength (p = 0.005), right (Rt) superior angle 0° (p = 0.004), Rt superior angle 45° (p = 0.015) and Rt inferior angle 90° (p = 0.013). This study shows a significant difference in extension range of motion and cervical core strength of violin players. Also, there was scapular dyskinesia seen at 0° and 45° right-side superior angle of the scapula and 90° right-side inferior angle of the scapula.

  14. An Analysis of Creative Process Learning in Computer Game Activities Through Player Experiences

    Directory of Open Access Journals (Sweden)

    Wilawan Inchamnan

    2016-09-01

    Full Text Available This research investigates the extent to which creative processes can be fostered through computer gaming. It focuses on creative components in games that have been specifically designed for educational purposes: Digital Game Based Learning (DGBL. A behavior analysis for measuring the creative potential of computer game activities and learning outcomes is described. Creative components were measured by examining task motivation and domain-relevant and creativity-relevant skill factors. The research approach applied heuristic checklists in the field of gameplay to analyze the stage of player activities involved in the performance of the task and to examine player experiences with the Player Experience of Need Satisfaction (PENS survey. Player experiences were influenced by competency, autonomy, intuitive controls, relatedness and presence. This study examines the impact of these activities on the player experience for evaluating learning outcomes through school records. The study is designed to better understand the creative potential of people who are engaged in learning knowledge and skills during the course while playing video games. The findings show the creative potential that occurred to yield levels of creative performance within game play activities to support learning. The anticipated outcome is knowledge on how video games foster creative thinking as an overview of the Creative Potential of Learning Model (CPLN. CPLN clearly describes the interrelationships between principles of learning and creative potential, the interpretation of the results is indispensable.

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

    Science.gov (United States)

    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.

  16. The Health Show

    OpenAIRE

    Swann, David

    2011-01-01

    Dr David Swann interviewed on The Health Show, Series 1, Episode 5, 2011 for BBC World about the award-winning 21st Century Nursing Bag. BBC World News reaches 241million people every week, available in 296 million homes, 1.8 million hotel rooms and has the highest average viewership on a weekday of any international news channel. The Health Show is a new 26-part series for BBC World News covering the most important news stories from around the world.

  17. Recognition accuracy by experienced men and women players of basketball.

    Science.gov (United States)

    Millslagle, Duane G

    2002-08-01

    This study examined 30 experienced basketball players' recognition accuracy by sex, playing position (guard, forward, and center), and situations in the game of basketball. The study used a perceptual cognitive paradigm in which subjects viewed slides of structured and unstructured game situations and accurately recognized the presence or absence of the basketball. A significant difference in recognition accuracy by sex, players' position, and structure of the game situation was found. Male players' recognition accuracy was better than the female players'. The recognition accuracy of subjects who played guard was better than that of subjects who played forward or center. The players' recognition accuracy was more accurate when observing structured plays versus unstructured plays. The conclusion of this study suggested that experienced basketball players differ in their cognitive and visual searching processes by sex and player position within the sport of basketball.

  18. Responder Feelings in a Three-Player Three-Option Ultimatum Game:Affective Determinants of Rejection Behavior

    OpenAIRE

    Hans-Rüdiger Pfister; Gisela Böhm

    2012-01-01

    This paper addresses the role of affect and emotions in shaping the behavior ofresponders in the ultimatum game. A huge amount of research shows that players do not behave in an economically rational way in the ultimatum game, and emotional mechanisms have been proposed as a possible explanation. In particular, feelings of fairness, anger and envy are likely candidates as affective determinants. We introduce a three-player ultimatum game with three-options, which permits the responder to eith...

  19. Injury frequency and body composition of elite Romanian rugby players

    Directory of Open Access Journals (Sweden)

    Bogdan ALMĂJAN-GUȚĂ

    2017-03-01

    Full Text Available Background: The physical exertion in the game of rugby is intense and depends on the playing position. This study hypothesized that peculiarities of body composition are important and should be properly interpreted in order to improve fitness and particularly in order to reduce the risk of injuries. Purpose: The aim of the present paper is to highlight the importance of body composition evaluation and to underline the usefulness of the data thus obtained for both training individualization and sports injuries risk reduction. Material and Methods: Thirty seven senior male rugby players from the former Romanian national team were assessed on body composition using a segmental multi-frequency bio-impedance analyzer InBody 720 (The Body Composition Analyzer – South Korea. We compared the results from both the preseason and the regular season 2012 with the international norms for elite players and we categorized the data by playing positions. Results: We have analyzed the amount of lean mass on each limb (kg, body water content (l, percentage of body fat, bone mineral and protein content (kg. We observed that the number of injuries is directly correlated to high levels of body fat percentage, low lean mass, and edema scores. Conclusions: The risk of injury can be identified among elite rugby players not only by using fitness tests, but also by using a simple and objective test of body composition. These results show how important it is to monitor the level of body fat, lean muscle mass and muscular development in order to modify nutrition and food habits, individualize trainings and thus reduce the number of injuries.

  20. Lower Body Stiffness and Muscle Activity Differences Between Female Dancers and Basketball Players During Drop Jumps

    OpenAIRE

    2011-01-01

    Background: Anterior cruciate ligament (ACL) injuries often occur during landing, with female athletes at higher injury risk than male athletes. Interestingly, female dancers have lower ACL injury rates than do female athletes in general. Hypothesis: Female dancers will have earlier and greater lower extremity muscle activity and higher sagittal knee joint and leg stiffness than will female basketball players. Study Design: Cross-sectional group comparison. Methods: Fifty-five healthy female ...

  1. Impact of Increased Football Field Width on Player High-Speed Collision Rate.

    Science.gov (United States)

    Joseph, Jacob R; Khalsa, Siri S; Smith, Brandon W; Park, Paul

    2017-07-01

    High-acceleration head impact is a known risk for mild traumatic brain injury (mTBI) based on studies using helmet accelerometry. In football, offensive and defensive players are at higher risk of mTBI due to increased speed of play. Other collision sport studies suggest that increased playing surface size may contribute to reductions in high-speed collisions. We hypothesized that wider football fields lead to a decreased rate of high-speed collisions. Computer football game simulation was developed using MATLAB. Four wide receivers were matched against 7 defensive players. Each offensive player was randomized to one of 5 typical routes on each play. The ball was thrown 3 seconds into play; ball flight time was 2 seconds. Defensive players were delayed 0.5 second before reacting to ball release. A high-speed collision was defined as the receiver converging with a defensive player within 0.5 second of catching the ball. The simulation counted high-speed collisions for 1 team/season (65 plays/game for 16 games/season = 1040 plays/season) averaged during 10 seasons, and was validated against existing data using standard field width (53.3 yards). Field width was increased in 1-yard intervals up to 58.3 yards. Using standard field width, 188 ± 4 high-speed collisions were seen per team per season (18% of plays). When field width increased by 3 yards, high-speed collision rate decreased to 135 ± 3 per team per season (28% decrease; P football field width can lead to substantial decline in high-speed collisions, with potential for reducing instances of mTBI in football players. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Retear of anterior cruciate ligament grafts in female basketball players: a case series

    Directory of Open Access Journals (Sweden)

    Tanaka Yoshinari

    2010-03-01

    Full Text Available Abstract Background Incidence of anterior cruciate ligament (ACL injuries in young female basketball players is higher than that in male basketball players. Graft retears are more frequent with the increasing number of ACL reconstructions. The present study aimed to examine the incidence of retears in competitive female basketball players. Methods Sixty-four female basketball players (aged 12 to 29 years who underwent primary anatomic double-bundle ACL reconstruction using hamstring grafts participated in the study. We investigated incidence, mechanism, and patient characteristics of ACL graft retears. Mann-Whitney U test was used for statistical analysis, and the level of significance was determined at P Results Six patients suffered from ACL graft retear (9.4%. Mean duration between primary ACL reconstruction and incidence of retears was 11.7 months. However, there were no other postoperative graft ruptures after 24 months. Primary injury and retear mechanisms varied by patient. At six months after the primary ACL reconstruction surgery, mean quadriceps and hamstring strengths were 81% and 87%, respectively, indicating favorable recovery of muscle strength. However, preoperative quadriceps and hamstring strength in the retear group were 65% and 71%, respectively. In particular, preoperative quadriceps strength in the retear group demonstrated a lower value than that in the uninjured group (P Conclusions We observed a high incidence of ACL graft retears in competitive female basketball players, as previously reported. Considering the timing of graft retear occurrences, an early return to playing basketball should be avoided following ACL reconstruction. Closer attention should be paid to player preoperative condition, as well as muscle strength and postoperative status.

  3. Prevalence and determinants of symptoms of common mental disorders in retired professional Rugby Union players.

    Science.gov (United States)

    Gouttebarge, Vincent; Kerkhoffs, Gino; Lambert, Mike

    2016-08-01

    The primary aim of this study was to determine the prevalence of symptoms of common mental disorders (CMD) (distress, anxiety/depression, sleeping disturbance, adverse nutrition behaviour, adverse alcohol behaviour and smoking) among retired professional Rugby Union players. The secondary aim was to explore the associations between stressors (life events, Rugby Union career dissatisfaction) and the health conditions under study. Therefore, cross-sectional analyses were conducted on baseline questionnaires from an ongoing prospective cohort study of retired professional Rugby Union players. An electronic questionnaire was established using validated questionnaires to assess symptoms of CMD and stressors. The electronic questionnaire was subsequently distributed to retired players by the national Rugby Union players' associations in France, Ireland and South Africa. Among 295 retired professional Rugby Union players (mean age of 38 years), prevalence rates were 25% for distress, 28% for anxiety/depression, 29% for sleeping disturbance, 62% for adverse nutrition behaviour, 15% for smoking and 24% for adverse alcohol behaviour. A higher number of life events were associated with distress (OR = 1.2; 95% CI 1.1-1.4), anxiety/depression (OR = 1.6; 95% CI 1.2-2.1), sleeping disturbance (OR = 1.6; 95% CI 1.2-2.1) and adverse nutrition behaviour (OR = 1.8; 95% CI 1.3-2.5). A higher level of dissatisfaction of the player's Rugby Union career was associated with distress (OR = 0.9; 95% CI 0.8-1.0), sleeping disturbance (OR = 0.9; 95% CI 0.9-1.0), smoking (OR = 0.9; 95% CI 0.9-1.0) and adverse nutrition behaviour (OR = 0.9; 95% CI 0.8-0.9). In conclusion, our study suggests that prevalence of symptoms of CMD is high among retired professional Rugby Union players, being associated with both a higher number of life events and a higher level of Rugby Union career dissatisfaction.

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

    Science.gov (United States)

    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.

  5. A Fashion Show

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Story: The yearly fashion show day.The children take turns to walk on the stage and show the class their favorite clothes.Now it’s Joe’s and Phoebe’s turn.Joe walks on the stage and says,“My shorts are blue.Do you like my blue shorts?”On the other side of the stage, Phoebe is wearing her favorite pink skirt.“My skirt is pink.Do you like my pink skirt?”asks

  6. Risk Factors for Injury Among Japanese Collegiate Players of American Football Based on Performance Test Results.

    Science.gov (United States)

    Iguchi, Junta; Watanabe, Yuya; Kimura, Misaka; Fujisawa, Yoshihiko; Hojo, Tatsuya; Yuasa, Yasuhiro; Higashi, Shinsuke; Kuzuhara, Kenji

    2016-12-01

    Iguchi, J, Watanabe, Y, Kimura, M, Fujisawa, Y, Hojo, T, Yuasa, Y, Higashi, S, and Kuzuhara, K. Risk factors for injury among Japanese collegiate players of American football based on performance test results. J Strength Cond Res 30(12): 3405-3411, 2016-The purpose of this study was to identify how risk factors for injury during American football are related to players' physical strength as determined using typical performance tests. One hundred 53 Japanese collegiate players of American football were recruited for this study. Eight potential risk factors were evaluated: position (skill vs. lineman), body mass index, back squat one-repetition maximum, vertical jump height, power, height, body weight, and previous injury. Using multivariate Cox regression, we examined how these factors were associated with knee sprain, ankle sprain, and hamstring strain. We recorded 63 injuries (17 knee sprains, 23 ankle sprains, and 23 hamstring strains). Players with higher power were at significantly greater risk for knee sprains (p = 0.04), those with low power had a significantly higher incidence of ankle sprain (p = 0.01), and vertical jump height was a significant predictor of hamstring strain (p = 0.02). We identified several independent predictors of injuries associated with American football. Our findings may contribute to the development of effective screening tests and prevention exercises.

  7. Injuries in elite youth football players: a prospective three-year study.

    Science.gov (United States)

    Ergün, Metin; Denerel, H Nevzad; Binnet, Mehmet S; Ertat, K Ahmet

    2013-01-01

    The aim of this study was to investigate the incidence and nature of injuries and the influence of age on injury patterns in elite youth football. Fifty-two players of the Under-17 (U-17) male national youth football team were followed during their progression to U-18 and U-19. Individual player exposure and injuries were recorded during the three year study period. Injury incidence was five times higher during matches than training. When medical attention and time loss injuries were considered, injury incidence increased during matches and decreased during training with increasing age. Traumatic injuries were more frequent in matches and were linked with increased age. Overuse injuries were two times higher during training than matches in the U-17 team. The majority of traumatic match injuries (78.3%) led to time loss and the majority of time loss injuries occurred due to traumatic mechanism (62.1%). The majority of muscle and entire ligament injuries occurred during training and contusions during competition. Re-injury rate was 25% and were all overuse injuries. Injury incidences increased during matches and decreased during training. More match injuries were caused by traumatic mechanisms as players aged. Player age might contribute to injury incidence and characteristics in youth football.

  8. Acute effects of two different tennis sessions on dorsal and lumbar spine of adult players.

    Science.gov (United States)

    Gallotta, Maria Chiara; Bonavolontà, Valerio; Emerenziani, Gian Pietro; Franciosi, Emanuele; Tito, Alessandro; Guidetti, Laura; Baldari, Carlo

    2015-01-01

    The aim of the study was to evaluate the dorsal and lumbar spine of expert and recreational tennis players before (pre) and after (post) two different training sessions. The sample consisted of 17 male tennis players, nine expert and eight recreational males (age 21.2 ± 1.6 years). We assessed the back surface by rasterstereography pre and post two different training sessions both lasting 1.5 h: a standard training and a specific over-shoulder shots training session, respectively. Lordotic and kyphotic angle, length, imbalance, inclination for trunk, pelvic torsion, left and right lateral deviation and surface rotation were measured. Tennis expertise (expert versus recreational) significantly affected the surface rotation and right lateral deviation (P tennis players had higher values on surface rotation and right lateral deviation, around or just above physiological values (0-5° and 0-5 mm, respectively). Type of session significantly affected left lateral deviation, indicating that over-shoulder shots lead to a higher stress for the spine; the workload produced by both single sessions led to a shortening effect on trunk length. A single training session can induce acute modifications in some parameters of dorsal and lumbar spine of players.

  9. Somatic, Endurance Performance and Heart Rate Variability Profiles of Professional Soccer Players Grouped According to Age

    Directory of Open Access Journals (Sweden)

    Botek Michal

    2016-12-01

    Full Text Available This cross-sectional study compared somatic, endurance performance determinants and heart rate variability (HRV profiles of professional soccer players divided into different age groups: GI (17–19.9 years; n = 23, GII (20–24.9 years; n = 45, GIII (25–29.9 years; n = 30, and GIV (30–39 years; n = 26. Players underwent somatic and HRV assessment and maximal exercise testing. HRV was analyzed by spectral analysis of HRV, and high (HF and low (LF frequency power was transformed by a natural logarithm (Ln. Players in GIV (83 ± 7 kg were heavier (p 25 years showed negligible differences in Pmax unlike the age group differences demonstrated in VO2max. A shift towards relative sympathetic dominance, particularly due to reduced vagal activity, was apparent after approximately 8 years of competing at the professional level.

  10. The effects of resistance training on explosive strength indicators in adolescent basketball players.

    Science.gov (United States)

    Santos, Eduardo J A M; Janeira, Manuel A A S

    2012-10-01

    The purpose of this study was to assess the effects of a lower- and upper-body 10-week in-season resistance training program on explosive strength development in young basketball players. Twenty-five adolescent male athletes, aged 14-15 years old, were randomly assigned to an experimental group (EG; n = 15) and a control group (CG; n = 10). The subjects were assessed at baseline and after training for squat jump (SJ), countermovement jump (CMJ), Abalakov test, drop jump, and seated medicine ball throw (MBT). The EG showed significant increases (p training program with moderate volume and intensity loads increased vertical jump and MBT performance in adolescent male basketball players. Coaches should know that such a short resistance training program specifically designed for young basketball players induce increased explosivity levels, which are essential to a better basketball performance, with no extra overload on adolescents' skeletal muscle development.

  11. Comparison of the Anaerobic Power of Brazilian Professional Football Players Grouped by Tactical Position

    Directory of Open Access Journals (Sweden)

    Renan Renato Cruz dos Santos

    2014-09-01

    Full Text Available The purpose of this study was to describe anthropometric characteristics and body composition of elite handball and basketball players as well as to make comparisons between them. Fifty-nine males were enrolled in the study, divided into three groups: fifteen handball players, fourteen basketball players and thirty healthy sedentary subjects. The descriptive statistics were expressed as a mean (SD for each variable, while the ANOVA and LSD Post Hoc tests were carried out to detect the effects of each type of sport. The results showed there was no significant difference in body mass index among the groups, while a significant difference was found for body height and body weight as well as for all three of the body contents measured (muscle, bone and fat among the groups. These findings may give coaches from the region better working knowledge and suggest to them to follow recent selection process methods and to be more careful during the recruitment.

  12. Technical and tactical soccer players' performance in conceptual small-sided games

    Directory of Open Access Journals (Sweden)

    Cristian Javier Ramirez Lizana

    2015-09-01

    Full Text Available AbstractConceptual small-sided games (CSSGs may be interesting as a methodology for training soccer players given its connection to the unpredictability that is inherent to soccer. Our aim was investigate, through videogrammetry, if the technical and tactical principles promoted through the adoption of distinct rules from two distinct CSSGs (maintaining ball possession; and progression to the target would actually be achieved. The study included 24 athletes assigned to 6-player teams. Our data showed that the CSSGs' organising principles create situations with differing levels of difficulty that obey the propositions of maintaining ball possession and progression to the target, i.e., CSSGs permit systematic training on technical and tactical components in order to emphasize the concepts adopted in this study in games context. Our data credit the CSSGs for teaching technical and tactical lessons that, when coupled with adequate physical conditioning, can facilitate a player's capacity to merge thoughts and events in different situations.

  13. [Motivational climate and coaches' communication style predict young soccer players' commitment].

    Science.gov (United States)

    Torregrosa, Miquel; Sousa, Catarina; Viladrich, Carme; Villamarín, Francisco; Cruz, Jaume

    2008-05-01

    The purpose of this research was to study the role of coaches' communication style and coach-created motivational climate in young soccer players' enjoyment and commitment. Four hundred and fifteen young soccer players of high competitive level in the age range from 14 to 16 completed the following questionnaires: a) coach-induced perceived motivational climate (PMCSQ-2), b) coaches' behaviour perception (CBAS-PBS), and c) sport commitment (SCQ). Results showed that coach-created motivational climate correlated highly with the perception of coaches' communication style. Moreover, coach-created motivational climate and communication style significantly determines players' sport commitment and enjoyment. Discussion focuses on the importance of seeking and training credible coaches that favours athletes' commitment.

  14. Brain structure in diving players on MR imaging studied with voxel-based morphometry

    Institute of Scientific and Technical Information of China (English)

    Gaoxia Wei; Jing Luo; Youfa Li

    2009-01-01

    We adopted professional diving players as a typical subject pool to explore whether structural brain differences relative to motor skill acquisition exist between highly skilled athletes and non-athletes. Based on the voxel-based morphometric (VBM) technique, structural MRIs of the brains of 12 elite diving players with professional training were analyzed and compared with those of control subjects with-out any professional physical training. Diving players showed significantly increased gray matter density in the thalamus and left pre-central gyrus than control subjects. However, future researches are needed to prove the contribution of preposition and practice. It also suggests that athletes as the subject pool could form a new subject pool to explore plastic change induced by motor skill acquisition.

  15. Extended Stereopsis Evaluation of Professional and Amateur Soccer Players and Subjects without Soccer Background

    Directory of Open Access Journals (Sweden)

    Jan ePaulus

    2014-10-01

    Full Text Available Stereopsis is one of several visual depth cues. It has been evaluated for athletes of different types of sports in the past. However, most studies do not cover the full range of stereopsis performance. Therefore, we propose computer-supported stereopsis tests that provide an extended assessment and analysis of stereopsis performance including stereo acuity and response times. By providing stationary and moving stimuli they cover static and dynamic stereopsis. The proposed stereopsis tests were used to compare professional and amateur soccer players with subjects without soccer background. The soccer players could not perform significantly (p <= 0.05 superior than the subjects without soccer background. However, the soccer players showed significantly (p <= 0.01 superior choice reaction times for monocular stimuli. The results are in congruence with previous findings in literature.

  16. THE RELATIVE AGE EFFECT IN YOUTH SOCCER PLAYERS FROM SPAIN

    Directory of Open Access Journals (Sweden)

    David Gutierrez Diaz Del Campo

    2010-06-01

    Full Text Available The purpose of this study was to identify the existence of Relative Age Effect (RAE at youth level in both elite and amateur Spanish soccer clubs, and also to carry out an analysis providing with information on how this effect has evolved in recent years. We have obtained information on the youth teams of the 20 clubs belonging to the Spanish Professional Football League (LFP in two separate seasons (2005-2006 and 2008-2009 as well as data on five youth academies belonging to amateur clubs. The collected data revealed an over- representation of players born in the first months of the selection year in all groups of analysis (Elite 2005-2006, Elite 2008-2009 and Amateurs, although only the Elite groups showed significant variations in birth-date distribution in relation to the Spanish population. The results showed a reduction in RAE from the 2005-2006 season to the 2008-2009 season. The following variables - playing position, the number of years each player has spent in their specific age group and the category of the team at each club were shown not to have influence on the extent of RAE

  17. MOOD CHANGES FOLLOWING GOLF AMONG SENIOR RECREATIONAL PLAYERS

    Directory of Open Access Journals (Sweden)

    Haydn Jarrett

    2005-03-01

    Full Text Available Golf has been recommended as a relatively risk-free form of exercise for an ageing population. The aim of this study was to investigate the effects of playing a round of golf on mood states in recreational players. Ageing male golfers (N = 34; Age: M = 68.7, SD = 5.4 years completed a mood measure immediately before and after an 18-hole round of golf. Distance walked per game was measured using a pedometer. Results indicate reported scores on Anger, Depression, and Fatigue increased and Vigor reduced following the game. However, it should be noted that although there was an increase in unpleasant mood states, this should be seen in the context of the overall mood profile, which was positive. Pedometer results indicated golfers walked a mean distance of 10.21 km (± 1.11. Results show participants of this age-group engaged in a meaningful exercise session and that mood scores deteriorated following play. Findings from the present study show that elderly golfers experienced mood profiles following golf similar to younger athletes following competition. For golf to be recommended as an activity for promoting physical activity among an aging population, the player's ability to regulate unpleasant mood states should be considered. Future research should investigate the effects of experiencing negative mood states following golf on motivation to participate.

  18. Effect of player position on movement behaviour, physical and physiological performances during an 11-a-side football game.

    Science.gov (United States)

    Gonçalves, Bruno V; Figueira, Bruno E; Maçãs, Vítor; Sampaio, Jaime

    2014-01-01

    The aim of this study was to identify differences in time-motion, modified training impulse, body load and movement behaviour between defenders, midfielders and forwards, during an 11-a-side simulated football game. Twenty elite youth male footballers from the same squad participated in this study (age: 18.1 ± 0.7 years old, body mass: 70.5 ± 4.3 kg, height: 1.8 ± 0.3 m and playing experience: 9.4 ± 1.3 years). All data were collected using GPS units (SPI-Pro, GPSports, Canberra, Australia). The movement behaviour was measured with kinematic data, used to calculate position-specific centroids (defenders, midfielders and forwards), and processed with non-linear statistical procedures (approximate entropy normalised and relative phase). There were significant effects and interactions in all variables across the players' positions. The results showed that displacements of all players (defenders, midfielders and forwards) were nearer and more coordinated with their own position-specific centroids than with the other centroids. However, this coupling effect was stronger in midfield players and weaker in forwards. All players' dynamical positioning showed more irregularity when related to the forwards' centroid, as a consequence of their need to be less predictable when playing. The time-motion and physiological variables showed lower activity in forward players. Adding together, the results may contribute to a better understanding of players' specific performances and football complexity.

  19. On not showing scalps

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2016-01-01

    proposed by Janet Marstine, the editor of the Routledge Companion to Museum Ethics, I show how the museum succeeded in engaging users in questions of museum ethics. However, this specific debate on human remains in museums developed into an encounter between a global, museological discourse...

  20. Violence and TV Shows

    OpenAIRE

    ÖZTÜRK, Yrd. Doç. Dr. Şinasi

    2008-01-01

    This study aims to discuss theories on theviolent effects of TV shows on viewers, especiallyon children. Therefore, this study includes a briefdiscussion of definitions of violence, discussionof violence theories, main results of researcheson televised violence, measuring TV violence,perception of televised violence, individualdifferences and reactions to TV violence,aggressiveness and preferences for TV violence.

  1. Honored Teacher Shows Commitment.

    Science.gov (United States)

    Ratte, Kathy

    1987-01-01

    Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)

  2. A Visionary Show

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Seduction. Distinction. Relax. Pulsation. These are the "style universes" on display at Première Vision, heralded as "The World’s Premiere Fabric Show." Started more than 35 years ago by 15 French weavers, Première Vision has expanded beyond its

  3. Honored Teacher Shows Commitment.

    Science.gov (United States)

    Ratte, Kathy

    1987-01-01

    Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)

  4. Repeated Play of Families of Games by Resource-Constrained Players

    Directory of Open Access Journals (Sweden)

    Arina Nikandrova

    2013-07-01

    Full Text Available This paper studies a repeated play of a family of games by resource-constrained players. To economize on reasoning resources, the family of games is partitioned into subsets of games which players do not distinguish. An example is constructed to show that when games are played a finite number of times, partitioning of the game set according to a coarse exogenously given partition might introduce new symmetric equilibrium payoffs which Pareto dominate best equilibrium outcomes with distinguished games. Moreover, these new equilibrium payoffs are also immune to evolutionary pressure at the partition selection stage.

  5. Association Between MCT1 A1470T Polymorphism and Fat-Free Mass in Well-Trained Young Soccer Players.

    Science.gov (United States)

    Massidda, Myosotis; Eynon, Nir; Bachis, Valeria; Corrias, Laura; Culigioni, Claudia; Cugia, Paolo; Scorcu, Marco; Calò, Carla M

    2016-04-01

    The aim of this study was to investigate the association between the MCT1 A1470T polymorphism and fat-free mass in young Italian elite soccer players. Participants were 128 Italian male soccer players. Fat-free mass was estimated for each of the soccer player using age- and gender-specific formulas with plicometry. Genotyping for the MCT1 A1470T polymorphism was performed using polymerase chain reaction. The MCT1 A1470T genotypes were in agreement with the Hardy-Weinberg equilibrium distribution. The percentage of fat-free mass was significantly higher in soccer players with the TT genotype and in the T-allele-dominant model group (TT + AT) compared with the soccer players with the AA genotype. The MCT1 T allele is associated with the percentage of fat-free mass in young elite male soccer players. Elucidating the genetic basis of body composition in athletes could potentially be used as an additional tool for strength and conditioning professionals in planning and adjusting training. However, these results are preliminary and need to be replicated in more cohorts.

  6. Activity Profiles and Physiological Responses of Representative Tag Football Players in Relation to Playing Position and Physical Fitness

    Science.gov (United States)

    2015-01-01

    This study determined the physical fitness, match-activity profiles and physiological responses of representative tag football players and examined the relationship between physical fitness and the match-activity profile. Microtechnology devices and heart rate (HR) chest straps were used to determine the match-activity profiles of sixteen tag football players for five matches during the 2014 Australian National Championships. The relationships between lower body muscular power, straight line running speed and Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) and the match-activity profile were examined using Pearson’s correlation coefficients. Outside players had greater lower body muscular power (ES = 0.98) and straight line running speed (ES = 1.03–1.18) than inside players, and also covered greater very high-speed running (VHSR) distance/min (ES = 0.67) and reached higher peak running speeds (ES = 0.95) during matches. Inside and outside players performed a similar number of repeated high-intensity effort (RHIE) bouts and reported similar mean and maximum efforts per RHIE bout. However, there were differences between playing positions for mean and maximal RHIE effort durations (ES = 0.69–1.15) and mean RHIE bout recovery (ES = 0.56). Inside and outside players also reported small to moderate differences (ES = 0.43–0.80) for times spent in each HR zone. There were a number of moderate to very large correlations between physical fitness measures and match-activity profile variables. This study found lower body muscular power, straight line running speed and Yo-Yo IR2 to be related to the match-activities of representative tag football players, although differences between inside and outside players suggest that athlete testing and training practices should be modified for different playing positions. PMID:26642320

  7. Activity Profiles and Physiological Responses of Representative Tag Football Players in Relation to Playing Position and Physical Fitness.

    Directory of Open Access Journals (Sweden)

    Luke W Hogarth

    Full Text Available This study determined the physical fitness, match-activity profiles and physiological responses of representative tag football players and examined the relationship between physical fitness and the match-activity profile. Microtechnology devices and heart rate (HR chest straps were used to determine the match-activity profiles of sixteen tag football players for five matches during the 2014 Australian National Championships. The relationships between lower body muscular power, straight line running speed and Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2 and the match-activity profile were examined using Pearson's correlation coefficients. Outside players had greater lower body muscular power (ES = 0.98 and straight line running speed (ES = 1.03-1.18 than inside players, and also covered greater very high-speed running (VHSR distance/min (ES = 0.67 and reached higher peak running speeds (ES = 0.95 during matches. Inside and outside players performed a similar number of repeated high-intensity effort (RHIE bouts and reported similar mean and maximum efforts per RHIE bout. However, there were differences between playing positions for mean and maximal RHIE effort durations (ES = 0.69-1.15 and mean RHIE bout recovery (ES = 0.56. Inside and outside players also reported small to moderate differences (ES = 0.43-0.80 for times spent in each HR zone. There were a number of moderate to very large correlations between physical fitness measures and match-activity profile variables. This study found lower body muscular power, straight line running speed and Yo-Yo IR2 to be related to the match-activities of representative tag football players, although differences between inside and outside players suggest that athlete testing and training practices should be modified for different playing positions.

  8. Player Transformation of Educational Multiplayer Games

    DEFF Research Database (Denmark)

    Magnussen, Rikke; Misfeldt, Morten

    2004-01-01

    Children's great interest in multiplayer games has led to attempts to design educational multiplayer games. In this study, we have studied a test of an educational multiplayer game designed for mathematics education for children aged nine to twelve. In our observations, it became clear that pupils...... transformed the game to accommodate social interaction. With these transformed ways of playing the game, they managed to get to the top of the high score list while avoiding the educational parts of the game. Players transforming educational games to escape learning elements can be a problem when these games...... are used for formal education. In this paper we argue that player transformation of educational games can, however, be the basis of exciting and unconventional learning of valuable things, such as how to transform information technology to better accommodate social interaction....

  9. Common Injuries of Collegiate Tennis Players

    Directory of Open Access Journals (Sweden)

    Christian Wisdom Magtajas Valleser

    2017-09-01

    Full Text Available The purpose of this study is to determine the common injuries of Filipino collegiate tennis players; 110 varsity tennis players with a mean of 20 years old (SD ± 1.7 with an average playing experience of 12 years participated in the study. There was a 100% occurrence of at least one injury with an average rate of 5.98 injuries per person. The authors observed that the most commonly injured anatomical region is the lower extremity; ankles were recorded as the most commonly injured part. Other commonly injured areas included the shoulders and lower back. Furthermore, the most common injury type is tendinitis, sprains, and strains. The recorded injuries were mostly associated with overuse injuries, and the findings were similar to those of most other studies on tennis injuries. A larger sample size may provide more conclusive findings on tennis injuries, particularly in different levels of competition, such as recreational or professional athletes.

  10. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    -dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......Context personalisation is a flourishing area of research with many applications. Context personalisation systems usually employ a user model to predict the appeal of the context to a particular user given a history of interactions. Most of the models used are context...

  11. Shanghai Shows Its Heart

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The city known as China’s economic powerhouse showed a more caring face as host of the Special Olympic Games Between October 2 and 11,the Special Olympics Summer Games were hosted in Shanghai,the first time the 40-year-old athletic com- petition for people with intellectual disabilities came to a developing country. This Special Olympics was also larger than all previous games in temps of the number of athletes.

  12. The ambidextrous potential in soccer, and the trainability of the non-preferred foot of young elite soccer players

    DEFF Research Database (Denmark)

    Koertz, Rune; Andersen, T. Bull

    2014-01-01

    . METHODS: Participants were 23 male elite soccer players, 13-16 years of age. They trained 6 times a week. The participants, who were randomly divided into a training group (N.=12) and a control group (N.=11), completed a pre and post test, which for each player consisted of 16 shots with their non-preferred......AIM: The purpose of the present study was to evaluate if players and coaches should focus more on the non-preferred foot. The hypothesis of this study is that a small amount of training focusing on the non-preferred foot will improve the performance of the non-preferred foot for young elite players...... foot towards a goal corner in a soccer goal. Velocity and accuracy were measured. The training intervention for the training group consisted of 7-13 training sessions. RESULTS: The result showed only few statistic significant differences (P

  13. Whole-Person Impairment in Younger Retired NFL Players: The Orthopaedic Toll of a Professional Football Career.

    Science.gov (United States)

    Domb, Benjamin G; Carter, Chris; Finch, Nathan A; Hammarstedt, Jon E; Dunne, Kevin F; Stake, Christine E

    2014-05-01

    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. 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. Case series; Level of evidence, 4. 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. 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 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 7.5 (range, 3-14 seasons). The mean number of games played was 98.4 (range, 2-236 games). This study demonstrated

  14. Injuries in male and female semi-professional football (soccer) players in Nigeria: prospective study of a National Tournament.

    Science.gov (United States)

    Owoeye, Oluwatoyosi Babatunde Alex; Aiyegbusi, Ayoola Ibifubara; Fapojuwo, Oluwaseun Akinleye; Badru, Oluwaseun Abdulganiyu; Babalola, Anike Rasheedat

    2017-03-21

    Research on the epidemiology of football injuries in Africa is very sparse despite its importance for injury prevention planning in a continent with limited sports medicine resources. The vast majority of studies available in literature were conducted in Europe and only a very few studies have prospectively reported the pattern of football injury in Africa. The purpose of this study was to evaluate the incidence and pattern of injuries in a cohort of male and female semi-professional football players in Nigeria. A prospective cohort design was conducted, in which a total of 756 players with an age range of 18-32 years (356 males and 300 females) from 22 different teams (12 male and 10 female teams), were prospectively followed in a National Football Tournament. Physiotherapists recorded team exposure and injuries. Injuries were documented using the consensus protocol for data collection in studies relating to football injury surveillance. An overall incidence of 113.4 injuries/1000 h (95% CI 93.7-136.0) equivalent to 3.7 injuries/match and time-loss incidence of 15.6 injuries/1000 h were recorded for male players and 65.9 injuries/1000 h (95% CI 48.9-86.8) equivalent to 2.2 injuries/match and time-loss incidence of 7.9 injuries/1000 h were recorded for female players. Male players had a significantly higher risk of injuries [IRR = 1.72 (95% CI 1.23-2.45)]. Injuries mostly affected the lower extremity for both genders (n = 81, 70% and n = 31, 62% for males and females respectively). Lower leg contusion (n = 22, 19%) and knee sprain (n = 9, 18%) were the most common specific injury types for male and female players respectively. Most of the injuries were as a result of contact with another player (n = 102, 88%-males; n = 48, 96%-females). Time-loss injuries were mostly estimated as minimal (n = 11, 69%) for male players and severe (n = 4, 66%) for female players. The overall incidence of injuries among Nigerian semi-professional football

  15. Tibia and fibula fractures in soccer players.

    Science.gov (United States)

    Boden, B P; Lohnes, J H; Nunley, J A; Garrett, W E

    1999-01-01

    We performed a retrospective review of 31 athletes who sustained a fracture of the lower leg from a direct blow while playing soccer. Fifteen fractures involved both the tibia and fibula 11 only the tibia, and 5 only the fibula. Information was collected using a standardized questionnaire. The mean follow-up from the time of injury was 30 months. Injuries typically occurred in young, competitive athletes during game situations. The mechanisms were broadly classified into several categories: contact during a slide tackle (13, 42%), a collision with the goalkeeper (8, 26%), two opposing players colliding while swinging for a loose ball (7, 23%)