The influence of variable resistance moment arm on knee extensor performance

Abstract

To enhance muscular strength, resistance training machines with a cam, incorporating a variable resistance moment arm, are widely used. However, little information is available about the influence of the variable resistance moment arm on torque, velocity, and power during muscle contraction. To address this, a knee extensor machine was equipped with a cam or with a semi-circular pulley that imposed a variable or a constant resistance moment arm, respectively. Fourteen physically active men performed two full knee extensions against loads of 40–80 kg in both conditions. Participants developed significantly higher torque with the pulley than with the cam (P < 0.001). The relative differences between pulley and cam conditions across all loads ranged from 8.72% to 19.87% (P < 0.001). Average knee extension velocity was significantly higher in the cam condition than in the pulley condition. No differences were observed in average and peak power, except at 50 and 55 kg. Torque–velocity and power–velocity relationships were modified when the resistance moment arm was changed. In conclusion, whatever the link, namely cam or pulley, the participants produced similar power at each load. However, the torque–velocity and power–velocity relationships were different in the cam and pulley conditions. The results further suggest that the influence of the machine's mechanism on muscular performance has to be known when prescribing resistance exercises.     

An ethic of care and educational practice

This article explicates the theoretical framework of an ethic of care and outlines recommendations for applying the framework to practice in adventure education, offering possibilities for re-imagining organizations as centrally concerned with compassion and care. Focusing on the work of Gilligan and Noddings, we suggest an understanding of an ethic of care that is contextual, ungendered, and inclusive of both the private and public spheres of life, and draw parallels between this ethic and the philosophies underlying Outward Bound specifically, and adventure education more generally. Finally, we outline possibilities for organizing educational curricula around centres of care for self, others, and the natural world, using Noddings' suggested curricular components of modeling, dialogue, practice, and confirmation.     

Models of Learning Support in Victorian Universities: Issues and Implications

In recent years changes in policy, the spate of amalgamations of tertiary institutions, changes in secondary education and the move in institutions toward intemationalisation, have led to a diversification of student populations in Australian universities. One response to these changes has been the expansion of the provision of student learning support within universities. This study examined the models of such support in Victorian universities. The location of support units, sources of funding, communication between different units at the same institution and staff conditions were identified as core issues in how learning support is delivered. A suggested model for delivery of learning support is proposed.     

Measuring Graph Comprehension,Critique, and Construction in Science

Interpreting and creating graphs plays a critical role in scientific practice. The K-12 Next Generation Science Standards call for students to use graphs for scientific modeling, reasoning, and communication. To measure progress on this dimension, we need valid and reliable measures of graph understanding in science. In this research, we designed items to measure graph comprehension, critique, and construction and developed scoring rubrics based on the knowledge integration (KI) framework. We administered the items to over 460 middle school students. We found that the items formed a coherent scale and had good reliability using both item response theory and classical test theory. The KI scoring rubric showed that most students had difficulty linking graphs features to science concepts, especially when asked to critique or construct graphs. In addition, students with limited access to computers as well as those who speak a language other than English at home have less integrated understanding than others. These findings point to the need to increase the integration of graphing into science instruction. The results suggest directions for further research leading to comprehensive assessments of graph understanding.     

Cognitive Difficulties in Struggling Comprehenders and Their Relation to Reading Comprehension: A Comparison of Group Selection and Regression-Based Models

ABSTRACT

Difficulties suppressing previously encountered but currently irrelevant information from working memory characterize less skilled comprehenders in studies in which they are matched to skilled comprehenders on word decoding and nonverbal IQ. These “extreme” group designs are associated with several methodological issues. When sample size permits, regression approaches permit a more accurate estimation of effects. Using data for students in Grades 6 through 12 (n = 766), regression techniques assessed the significance and size of the relation of suppression to reading comprehension across the distribution of comprehension skill. After accounting for decoding efficiency and nonverbal IQ, suppression, measured by performance on a verbal proactive interference task, accounted for a small amount of significant unique variance in comprehension (less than 1%). A comparison of suppression in less skilled comprehenders matched to more skilled comprehenders (48 per group) on age, word reading efficiency, and nonverbal IQ did not show significant group differences in suppression. The implications of the findings for theories of reading comprehension and for informing comprehension assessment and intervention are discussed.     

Taking stock of sustainability in higher education: a review of the policy literature

Abstract

This paper provides a review of the current literature that examines the uptake of sustainability policies in higher education. Articles were retrieved from both ERIC and Scopus databases and then manually reviewed to ensure that they focused on each of: higher education; sustainability; and policy. A total of 91 articles were analysed using a multi-stage process that involved sorting data according to typologies (i.e. temporal, terminology, methodology, geography), coding the text of the articles based on topical content, and an indexing method used to label data for further analysis and the development of broader code categories. Results suggest that drivers and barriers associated with the integration of sustainability policy in higher education are well known; yet increased research is needed to understand best practices and processes by which sustainability can be furthered through higher education policy. In addition, findings demonstrate the need for future research to focus on various aspects of the policy process, including policy development and enactment, and on implications of policy for practice. While there have been some reviews of sustainability policy in higher education research to date, this review contributes to this literature by highlighting research primarily focused on sustainability policy within higher education.     

Student engagement: rhetoric and reality

Recently, there has been much interest in higher education literature and policy on the concepts of student engagement and disengagement. While most academic writings recognise the significance of student engagement, they have tended to concentrate on it in relation to academic activities. Increasingly, universities are ‘cascading’ down the need to improve student engagement to schools and ultimately to individual academics. This article asserts that ideas about student engagement in the university context are often fragmented, contradictory and confused. Even the meaning of the term ‘student engagement’ is uncertain. Further, while government and universities urge attention to student engagement, many of their actions, it may be argued, have contributed to greater student disengagement. Relying on the available literature, we argue that the student experience as a whole is the key to engagement and, thus, efforts to re-engage students cannot be successful until a ‘whole-of-university’ approach is adopted.     

Personal Leadership in Practice: A Critical Approach to Instructional Design Innovation Work

An argument is made in this article for a link between leadership and innovation, when innovation is an outcome of the work approaches and practices that underpin an educational technologist’s academic course designs. The practice of instructional design (ID) is continually being challenged to rethink its conceptualization of academic course designs, especially for web-based affordances, to release designers to new processes that more align with the modern use of communication devices and networks. I suggest here that the time has come for ID to leave non-adaptive, linear thinking behind not only in how and when to prescribe certain technologies but in how to approach educational change with an adaptation of personal leadership that drives innovation (Ashbaugh, 2012).     

A framework for assessing market entry opportunities for internet‐based TV

Abstract

The advent of the Internet alleviates the access bottleneck to TV distribution channels and softens licensing requirements. This lowers entry barriers to TV markets via the Internet in various forms. This paper takes the German TV sector as an example to analyse the attractiveness of TV markets for new entrants. A sequential framework for entering TV markets is introduced. The skills set of an Internet‐based TV provider for such an entry is examined. Technical feasibility, legal aspects, and potential sources of revenue are considered.

Potential above average profits due to the market's oligopolistic structure, as well as an increased contestability thanks to lower market entry barriers seem to render the German TV market attractive for new entrants. In early 2002, Internet‐based TV still faced severe technical and legal constraints. The analysis suggests that once these constraints have been overcome, the Internet could be an attractive additional distribution channel for some types of television content. While existing revenue sources from the TV sector are expected to be transferable to a certain degree, the value of innovative revenue sources based on online sales cannot yet be determined. This value will depend on the future acceptance of interactivity by the viewer (e. g. Owen 1999).