title: The implications of time on the ground on running economy: Less is not always better

authors: Lussiana, Thibault

subjects: Science & Technology

abstract: A lower duty factor (DF) reflects a greater relative contribution of leg swing to ground contact time during the running step. Increasing time on the ground has been reported in the scientific literature to both increase and decrease the energy cost (EC) of running, with DF reported to be highly variable in runners. As increasing running speed aligns running kinematics more closely with spring-mass model behaviors and re-use of elastic energy, we compared the centre of mass (COM) displacement and EC between runners with a low (DFlow) and high (DFhigh) duty factor at typical endurance running speeds. Forty well-trained runners were divided in two groups based on their mean DF measured across a range of speeds. EC was measured from 4-min treadmill runs at 10, 12, and 14 km·h−1 using indirect calorimetry. Temporal characteristics and COM displacement data of the running step were recorded from 30-s treadmill runs at 10, 12, 14, 16, and 18 km·h−1. Across speeds, DFlow exhibited more symmetrical patterns between braking and propulsion phases in terms of time and vertical COM displacement than DFhigh. DFhigh limited global vertical COM displacements in favor of horizontal progression during ground contact. Despite these running kinematics differences, no significant difference in EC was observed between groups. Therefore, both DF strategies seem energetically efficient at endurance running speeds.

text: The implications of time on the ground on running economy: Less is not always better A lower duty factor (DF) reflects a greater relative contribution of leg swing to ground contact time during the running step. Increasing time on the ground has been reported in the scientific literature to both increase and decrease the energy cost (EC) of running, with DF reported to be highly variable in runners. As increasing running speed aligns running kinematics more closely with spring-mass model behaviors and re-use of elastic energy, we compared the centre of mass (COM) displacement and EC between runners with a low (DFlow) and high (DFhigh) duty factor at typical endurance running speeds. Forty well-trained runners were divided in two groups based on their mean DF measured across a range of speeds. EC was measured from 4-min treadmill runs at 10, 12, and 14 km·h−1 using indirect calorimetry. Temporal characteristics and COM displacement data of the running step were recorded from 30-s treadmill runs at 10, 12, 14, 16, and 18 km·h−1. Across speeds, DFlow exhibited more symmetrical patterns between braking and propulsion phases in terms of time and vertical COM displacement than DFhigh. DFhigh limited global vertical COM displacements in favor of horizontal progression during ground contact. Despite these running kinematics differences, no significant difference in EC was observed between groups. Therefore, both DF strategies seem energetically efficient at endurance running speeds.

year: 2019

title: Qualifying engagement: A study of information and communication technology and the global social justice movement in Aotearoa New Zealand

authors: Ganesh, Shiv

subjects: activism

abstract: Scholarly commentary has underscored the importance of new information and communication technologies (ICTs) in organizing the Global Social Justice Movement (GSJM). This study examines key communicative assumptions regarding technology and activist participation in the GSJM by asking three research questions: (a) what impacts of ICT-enabled brokerage are evident in the GSJM in Aotearoa New Zealand; (b) how are activists' attitudes embedded in the metaphors they use; and (c) what concerns do activists express about ICTs? Findings suggest strong associations between GSJM activists' conceptualizations of communication and their highly diverse attitudes toward and engagement with ICTs. Contrasts between activists and scholarly discussions of ICTs and the GSJM are highlighted.

text: Qualifying engagement: A study of information and communication technology and the global social justice movement in Aotearoa New Zealand Scholarly commentary has underscored the importance of new information and communication technologies (ICTs) in organizing the Global Social Justice Movement (GSJM). This study examines key communicative assumptions regarding technology and activist participation in the GSJM by asking three research questions: (a) what impacts of ICT-enabled brokerage are evident in the GSJM in Aotearoa New Zealand; (b) how are activists' attitudes embedded in the metaphors they use; and (c) what concerns do activists express about ICTs? Findings suggest strong associations between GSJM activists' conceptualizations of communication and their highly diverse attitudes toward and engagement with ICTs. Contrasts between activists and scholarly discussions of ICTs and the GSJM are highlighted.

year: 2010

title: Antipodean settler societies and their complexities: the Waitangi process in New Zealand and native title and the stolen generations in Australia

authors: Byrnes, Giselle

subjects: native title claim

abstract: This article considers the process of determining native title claims and responding to the revelation of forced Indigenous child removal in Australia, together with the Treaty of Waitangi claims process in New Zealand; each of which can be understood more broadly as a response to the aftermath and ongoing consequences of colonisation. We undertake this analysis comparatively, through an examination of the broad sweep of colonial history in both countries, followed by a more detailed consideration of the processes in question, as they have become manifest over the last decade or so in Australia and almost 30 years in New Zealand. We compare and contrast the institutions, epistemological and political preoccupations and language in each case, revealing various latent ironies and incongruities in the systems on both sides of the Tasman Sea.

text: Antipodean settler societies and their complexities: the Waitangi process in New Zealand and native title and the stolen generations in Australia This article considers the process of determining native title claims and responding to the revelation of forced Indigenous child removal in Australia, together with the Treaty of Waitangi claims process in New Zealand; each of which can be understood more broadly as a response to the aftermath and ongoing consequences of colonisation. We undertake this analysis comparatively, through an examination of the broad sweep of colonial history in both countries, followed by a more detailed consideration of the processes in question, as they have become manifest over the last decade or so in Australia and almost 30 years in New Zealand. We compare and contrast the institutions, epistemological and political preoccupations and language in each case, revealing various latent ironies and incongruities in the systems on both sides of the Tasman Sea.

year: 2008