Differences in 3D kinematics between volleyball and beach volleyball spike movements

The purpose of this study was to identify differences between volleyball and beach volleyball spike jump movements performed on an indoor surface and sand surface respectively. Eight elite male volleyball players performed spike jump movements on both surfaces. An eight-camera motion capturing system (250Hz) was used to generate 3D kinematic data. Seven groups of variables representing the kinematics of the centre of mass, the countermovement, the approach phase, and the angular amplitudes and maximal velocities of the lower and upper limbs were examined using Hotelling's T2(2). Significant differences were observed in the movement of the centre of mass (P < 0.05), the countermovement, the kinematics of the approach phase, and the angular amplitudes of the lower limbs. However, no significant differences were observed either in the maximal angular velocities of the lower and upper limbs, or in the amplitudes of the upper limb motion. In conclusion, the participants showed significant adaptation to changed movement conditions. As a result of the compliance of the sand surface, the participants slowed down their movements, especially during the phase of transition from knee flexion to extension and during the extension phase. Furthermore, the participants demonstrated changes in foot position to reach the greatest height possible.     

Training load characteristics and injury and illness risk identification in elite youth ski racing: A prospective study

PurposeThe study aimed to investigate the role of training load characteristics and injury and illness risk in youth ski racing.MethodsThe training load characteristics as well as traumatic injuries, overuse injuries, and illnesses of 91 elite youth ski racers (age = 12.1 ± 1.3 years, mean ± SD) were prospectively recorded over a period of 1 season by using a sport-specific online database. Multiple linear regression analyses were performed to monitor the influence of training load on injuries and illnesses. Differences in mean training load characteristics between preseason, in-season, and post-season were calculated using multivariate analyses of variance.ResultsDifferences were discovered in the number of weekly training sessions (p = 0.005) between pre-season (4.97 ± 1.57) and post-season (3.24 ± 0.71), in the mean training volume (p = 0.022) between in-season (865.8 ± 197.8 min) and post-season (497.0 ± 225.5 min) and in the mean weekly training intensity (Index) (p = 0.012) between in-season (11.7 ± 1.8) and post-season (8.9 ± 1.7). A total of 185 medical problems were reported (41 traumatic injuries, 12 overuse injuries, and 132 illnesses). The weekly training volume and training intensity was not a significant risk factor for injuries (p > 0.05). Training intensity was found to be a significant risk factor for illnesses in the same week (β = 0.348; p = 0.044; R² = 0.121) and training volume represents a risk factor for illnesses in the following week (β = 0.397; p = 0.027; R² = 0.157).ConclusionA higher training intensity and volume were associated with increased illnesses, but not with a higher risk of injury. Monitoring training and ensuring appropriate progression of training load between weeks may decrease incidents of illness in-season.     

The impact of previous type of abuse and sibling adoption upon adoptive families

OBJECTIVE: The paper addresses the impacts of the type of abuse and sibling adoption upon family functioning. The specific objectives are to test the relationships: (1). between an adopted child's previous type of abuse and postadoptive family functioning; (2). between an adopted child's previous type of abuse and the child's postadoptive externalized behavior status; (3). between sibling adoption status and postadoptive family functioning; and (4). between sibling adoption status and the child's postadoptive externalized behavior status. METHOD: Data were collected from parents with adopted children, between the ages of 2 and 16, who have special needs status. The convenience sample was drawn primarily from one southern state. RESULTS: The results suggest that the child's type of abuse does predict different outcomes in terms of a parent's report of postadoptive family functioning but not the adopted child's postadoptive externalized behavior. Sibling adoptions resulted in lower perceptions of family functioning but slightly improved perceptions of the child's postadoptive externalized behavior. CONCLUSION: Parents with adopted children who have histories of physical and sexual abuse reported lower family functioning than those parents with adopted children who only have histories of neglect. Parents who adopted sibling groups reported fewer externalized child behavior problems but lower family functioning than those parents who adopted a single child. These results suggest the need for a variety of family supports targeted to family needs as well as to promoting behavioral changes in the children.     

Inter- and transdisciplinary university: A systems approach to education and innovation

In response to various pressures for change arising from the present situation, the university will have to adopt a new purpose which may be recognized as a means of increasing the capability of society for continuous self-renewal. With this new purpose in mind, the structure of the university will be determined by the concept of an integral education/innovation system for which four principal levels are considered: empirical, pragmatic, normative and purposive levels. From multi-, pluri-, and crossdisciplinary approaches, all pertaining to one systems level only, the university is expected to develop increasingly interdisciplinary approaches, linking two systems levels and coordinating the activities at the lower level from the higher level through common axiomatics. Ultimately, the entire education/innovation system may become coordinated as a multilevel multigoal hierarchical system through a transdisciplinary approach, implying generalized axiomatics and mutual enhancement of disciplinary epistemology. Current university approaches to develop interdisciplinary links between the pragmatic and normative systems levels are discussed. Finally, a transdisciplinary structure for the university is briefly outlined; its main elements are three types of organizational units-systems design laboratories, function-oriented departments, and discipline-oriented departments-which focus on the interdisciplinary coordination between the three pairs of levels in the education/innovation system, i.e., on method and organization rather than on accumulated knowledge. An important role for policy sciences is seen in the linkage between the top pair of systems levels.

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Résumé Pour répondre aux sollicitations de son environnement actuel, l'Université devra se donner de nouveaux objectifs en partant du principe qu'il lui faut procurer à la société les moyens d'un renouvellement continu. On peut déduire la structure de l'Université, qui est ainsi exigée, de l'idée d'une liaison intime entre éducation et innovation: aux quatre niveaux à considérer, niveau empirique, niveau pragmatique, niveau des normes et niveau des stratégies. On attend de l'Université que, dépassant les activités multi- ou pluridisciplinaires qui ne se situent qu'à un niveau du système, elle réussisse à élaborer une méthodologie interdisciplinaire lui permettant de relier les différents niveaux et de coordonner d'un bout à l'autre du système les activités conformément à une logique unifiée. En somme, le système d'éducation et d'innovation considéré dans son ensemble pourrait tendre vers le modèle d'un système intégrant hiérarchiquement des niveaux et des objectifs multiples, grâce à une méthodologie transdisciplinaire impliquant le développement d'une logique généralisée et des échanges réciproques entre l'épistémologie des différentes disciplines. L'article soumet à la discussion les méthodes dont usent aujourd'hui les universités pour établir des liens d'interdisciplinarité entre le niveau pragmatique et le niveau des normes. En conclusion, est présentée une brève esquisse de ce que pourrait être la structure transdisciplinaire de l'Université: trois types d'unités s'y trouvent distingués dans l'organisation, les laboratoires d'élaboration des projets, les départements tournés vers la satisfaction d'une fonction et les départements tournés vers le travail dans une discipline; l'accent y est mis sur la coordination interdisciplinaire dans les trois mises en relation unissant deux à deux chacun des quatre niveaux du système d'éducation et d'innovation, autrement dit, sur la méthode et l'organisation, plus que sur l'accumulation de la connaissance. On fait voir le rôle important qui est réservé aux sciences de la décision dans la mise en relation des deux niveaux supérieurs du système.

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While developing some of the concepts reported in this paper, Dr. Jantsch held a visiting appointment as Research Associate at the Massachusetts Institute of Technology. This article is reprinted fromPolicy Sciences (American Elsevier Publishing Company, Inc.) 1 (1970) 403–428.     

The Graphic Arts

Max Gallo's The Poster in History (New York: American Heritage/McGraw- Hill, 1974—$22.95)

Erich Salomon's Portrait of an Age ((New York: Collier Books/Macmillan, 1974—$7.50, paper)

M. Thomas Inge's “American Comic Art: A Bibliographic Guide,” Choice XI:1581-1593

Stan Lee's Origins of Marvel Comics (New York: Simon and Schuster, 1974—$5.95, paper)

John Hedgecoe and Michael Langford's Photography: Materials and Methods published by Oxford University Press. Apparently Focal Press picked it up in London, and now a new smaller format but hardcover edition is just out from Hastings House (N.Y.) for $12.95     

The Second-Person Effect and Its Role in Formation of Active Issue Publics

This article explores the idea that the media encourage audience members to see issues as affecting both themselves and other members of the community—a perception termed second-person effects. The authors argue that second-person perceptions are an integral step toward the formation of active issue publics and significant predictors of a person's willingness to engage in behaviors necessary to resolve an issue. Results also show that second-person effects predominate when predicting intentions to take actions to address an issue. Thus, this supports the proposition that second-person effects are a key component in understanding the formation of active issue publics.