Quantifying elbow extension and elbow hyperextension in cricket bowling: a case study of Jenny Gunn

In this study a method for determining elbow extension and elbow abduction for a cricket bowling delivery was developed and assessed for Jenny Gunn who has hypermobility in both elbows and whose bowling action has been repeatedly queried by umpires. Bowling is a dynamic activity which is assessed visually in real time in a cricket match by an umpire. When the legality of a bowler's action is questioned by an umpire a quantitative analysis is undertaken using a marker based motion analysis system. This method of quantifying elbow extension should agree with a visual assessment of when the arm is "straight" and should minimise the effects of marker movement. A set of six markers on the bowling arm were used to calculate elbow angles. Differences of up to 1° for elbow extension and up to 2° for elbow abduction were found when angles calculated from the marker set for static straight arm trials were compared with measurements taken by a chartered sports physiotherapist. In addition comparison of elbow extension angles at ball release calculated from the markers during bowling trials with those measured from high speed video also showed good agreement with mean differences of 0°±2°.     

Putting proficiency: contributions of the pelvis and trunk

Putting proficiency is a key determinant of golfing success and yet minimal biomechanical research has been published on this important skill. Little is known about the motion and coordination of the pelvis and trunk during the putting motion. The purpose of this study was to present detailed three-dimensional (3D) kinematic profiles of the pelvis and trunk during the putting motion, and to determine if differences in kinematics exist between proficient and non-proficient golfers. A 3D analysis (100 Hz) was conducted on 10 single figure handicap golfers using a six-camera motion capture system. Participants completed 18 putts (2 m) towards a cup in an indoor facility and were subsequently divided into two groups based on putting proficiency (Proficient: >79%; Non-proficient: <79%). Variables assessed were the linear movements of the centre of mass (COM) and head, and the angular movements of the pelvis and trunk. Effect size statistics showed that the Proficient putters tended to move predominantly in the frontal plane (towards the target), while the non-proficient putters moved more sagittally. In addition, the Non-proficient putters recorded greater movement variability. The implications of this study suggest that putting proficiency is enhanced when the COM moves towards the target.     

DNS白名单会阻碍IPv6的实施吗？

什么是DNS白名单？在当今的公共互联网上使用IPv4地址时,解析程序可以向权威的域名服务器查询并接收IPv4的地址A记录。当一位权威DNS的管理员为指定域添加IPv6地址AAAA记录时,它将像A记录和其他RR一样被解析程序查询和接收。     

Developmentally invariant dissociations in children's true and false memories: not all relatedness is created equal

The role of categorical versus associative relations in 5-, 7-, and 11-year-old children's true and false memories was examined using the Deese-Roediger-McDermott (DRM) paradigm and categorized lists of pictures or words with or without category labels as primes. For true items, recall increased with age and categorized lists were better recalled than DRM lists. For false items, recall increased with age except for picture lists, there were no differences between categorized and DRM lists and no effect of priming, and there were fewer false memories for pictures than words. Like adults, children's false memories are based on associative not thematic relations, whereas their veridical memories depend on both. This new, developmentally invariant dissociation is consistent with knowledge- and resource-based models of memory development.     

Initial-link duration and acquisition of preference in concurrent chains

Initial-link response allocation in concurrent chains becomes less extreme as the absolute duration of the initial links increases (Fantino, 1969). The present study asked whether initial-link duration affected how quickly response allocation reached asymptote (i.e., acquisition of preference). Six pigeons were trained on a concurrent-chains procedure in which the terminal links were fixed-interval (FI) 8 sec FI 16 sec or FI 16 sec FI 8 sec and were reversed every 20 sessions. Across conditions, all possible combinations of transitions between variable-interval (VI) 8-sec (short) and VI 24-sec (long) initial-link schedules were studied. Overall, the rate of acquisition was faster when the durations of the initial links preceding the reversal were short rather than long, and when the durations of the initial links following the reversal were long rather than short. By contrast, initial-link duration had no effect on acquisition or asymptotic measures of temporal control of terminal-link responding. These results support the core principle of delay-reduction theory (Fantino, 1969) that the impact of a conditioned reinforcer varies directly with initial-link duration, but also suggest that temporal learning during the terminal links proceeds independently of initial-link duration. nt]mis|These data were presented at the annual meeting of the Association for Behavior Analysis, Boston, May 2004.     

Do individuals with autism process categories differently? The effect of typicality and development

This study examined the effect of exemplar typicality on reaction time and accuracy of categorization. High-functioning children (age 9-12), adolescents (age 13-16), and adults with autism (age 17-48) and matched controls were tested in a category verification procedure. All groups showed improved processing throughout the lifespan for typical and somewhat typical category exemplars. However, individuals with autism responded more slowly than matched controls to atypical exemplars at all ages. The results are discussed in terms of potential differences in the type of processing that may be required for categorizing typical and atypical category exemplars. Parallels are also drawn to the results of previous studies on face processing in individuals with autism.     

Prevalence of childhood sexual abuse among incarcerated males in county jail

OBJECTIVE: The current study examined the prevalence and characteristics of childhood sexual abuse in a jailed-based population. METHODOLOGY: A retrospective, self-reported survey was administered over an 8-week period to a random sample of 100 men who were incarcerated in a county jail in Southeastern Texas. The survey included questions about childhood sexual experiences before and after puberty, drug history and use, and sexual risk-taking behaviors. RESULTS: Of the 100 male inmates who participated in this study, 59% reported experiencing some form of sexual abuse before puberty, and all such instances occurred before or at the age of 13 years. The first episode of childhood sexual abuse began at an average age of 9.6 years (SD = 2.4), and ended at an average age of 13.0 years (SD = 2.3). Kissing and touching without intercourse (64%) was the common pattern of sexual abuse experience reported. The total number of perpetrators was 165, with 10% male and 90% female. Friends (n = 72) and family (n = 56) were the most frequent perpetrators. CONCLUSION: Childhood sexual abuse may be more prevalent among inmates than among males in the general population. These results show a high percentage of inmates who report a history of childhood sexual abuse; this rate is higher than those reported by other studies for incarcerated males. The findings support the belief held by professionals in the criminal justice field that a significant number of incarcerated males may have been victims of sexual abuse.     

Ranking of library and information science researchers: Comparison of data sources for correlating citation data,and expert judgments

This paper studies the correlations between peer review and citation indicators when evaluating research quality in library and information science (LIS). Forty-two LIS experts provided judgments on a 5-point scale of the quality of research published by 101 scholars; the median rankings resulting from these judgments were then correlated with h-, g- and H-index values computed using three different sources of citation data: Web of Science (WoS), Scopus and Google Scholar (GS). The two variants of the basic h-index correlated more strongly with peer judgment than did the h-index itself; citation data from Scopus was more strongly correlated with the expert judgments than was data from GS, which in turn was more strongly correlated than data from WoS; correlations from a carefully cleaned version of GS data were little different from those obtained using swiftly gathered GS data; the indices from the citation databases resulted in broadly similar rankings of the LIS academics; GS disadvantaged researchers in bibliometrics compared to the other two citation database while WoS disadvantaged researchers in the more technical aspects of information retrieval; and experts from the UK and other European countries rated UK academics with higher scores than did experts from the USA.