Impact forces and neck muscle activity in heading by collegiate female soccer players

Three soccer header types (shooting, clearing and passing) and two heading approaches (standing and jumping) were manipulated to quantify impact forces and neck muscle activity in elite female soccer players. The 15 participants were Division I intercollegiate soccer players. Impact forces were measured by a 15-sensor pressure array secured on the forehead. The electromyographic (EMG) activity of the left and right sternocleidomastoid and trapezius muscles was recorded using surface electrodes. Maximum impact forces and impulses as well as the EMG data were analysed with separate repeated-measures analyses of variance. Impact forces and impulses did not differ among the header types or approaches. Higher values were found for jumping versus standing headers in the mean normalized EMG for the right sternocleidomastoid. In addition, the integrated EMG was greater for the right sternocleidomastoid and right and left trapezius (P < 0.05). The sternocleidomastoid became active earlier than the trapezius and showed greater activity before ball contact. The trapezius became active just before ball contact and showed greater activity after ball contact. The increased muscle activity observed in the neck during the jumping approach appears to stabilize the connection between the head and body, thereby increasing the stability of the head-neck complex.     

Manipulating generalized motor program difficulty during blocked and random practice does not affect parameter learning

Blocked practice engenders more trial-to-trial response stability, which is thought to be crucial for developing the generalized motor program (GMP) but not parameter learning (Lai, Shea, Wulf, & Wright, 2000). It was hypothesized that reducing the difficulty of the GMP might permit additional cognitive resources to be allocated to learning the parameter requirements. However, GMP theory maintains the independence of the memories governing the GMP and parameters. This notion suggests that manipulating the difficulty of the GMP should have no effect on the blocked practice participant's ability to successfully specify the appropriate parameters. Participants learned a simple or complex relative timing pattern under either blocked or random practice conditions. Smaller GMP errors were exhibited for the simple relative timing patterns, but this was not associated with improvements in parameter specification following blocked practice. A clear advantage for parameter specification was evident in transfer following random practice. Taken together, these data support the theoretical separation of the GMP and parameter processes.     

Functional brain development in infants: elements of an interactive specialization framework

One future direction for cognitive development research involves a closer integration with our knowledge about the developing brain. I present a framework for analyzing and interpreting postnatal functional brain development in human infants. Three specific hypotheses contribute to this framework, within which a variety of phenomena associated with the neural basis of perception and cognition in normal and abnormal development can be characterized.     

Entwicklung gro?er Systeme mit generischen Methoden – Eine übersicht über den Sonderforschungsbereich 501

Ohne Zusammenfassung     

Objektorientierter Entwurf eines flexiblen Workflow-Management-Systems

Zusammenfassung.   Dieser Beitrag enth?lt die wesentlichen konzeptionellen überlegungen zur Entwicklung eines flexiblen Workflow-Management-Systems. Ausgehend von einer Diskussion m?glicher Modellierungsalternativen wird unter Verwendung objektorientierter Modellierungstechniken ein Workflow-Meta-Schema entwickelt, das die relevanten Entit?ten klassifiziert und ihre Beziehungen abbildet. Anhand eines Beispiels werden die getroffenen Entwurfentscheidungen ausführlich begründet. Schlie?lich werden Zust?nde und Zustandsüberg?nge von Workflow-Instanzen beschrieben, und es wird diskutiert, wie dynamische Ver?nderungen von Workflows zur Laufzeit durchgeführt werden k?nnen, um laufende Workflows dynamisch an ver?nderte Umweltbedingungen anzupassen. Eingegangen am 20. Dezember 1997 / Angenommen am 24. Juli 1998     

铅球最佳出手角的计算及其在实践中的应用

运用力学原理,通过数理推导编采了铅球最佳出手角及其射程表,并根据推铅球的运动生物力学特点,分析了理论上最佳出手角及其在实践应用中的局限性,提出理论上的最佳出手角可作为教学训练的定量指标,但并不是竞赛中的最佳出手角,在教学和训练中应结合实际,采用合理的出手角,以利于改进技术,指导训练,提高运动成绩。     

Dualisms in Higher Education: a Critique of Their Influence and Effect

Dualisms pervade the language of higher education research providing an over‐simplified roadmap to the field. However, the lazy logic of their popular appeal supports the perpetuation of erroneous and often outdated assumptions about the nature of modern higher education. This paper explores nine commonly occurring dualisms: collegiality/managerialism, student‐centred/teacher‐centred, deep learning/surface learning, academics/non‐academics; research/teaching, old universities/new universities, liberal/vocational, public universities/private universities and higher education/further education. Illustrated by reference to a range of international contexts, it is argued that over‐reliance on dualisms among higher education scholars has adverse effects including narrowing the possibilities of research design and inhibiting intellectual advancement within the field.