89 research outputs found
Resonance in Human Walking Economy: How Natural Is It?
Locomotion and movement economy are cornerstone topics in movement science. Modeling the leg as a hybrid mass-spring pendulum shows walking economy should be optimized when stride frequency matches the resonant frequency of the limb. Human walking is described as self-optimizing because mean preferred (PSF) and modeled resonant (RSF) stride frequencies usually are statistically equivalent, but this depiction may not be fully justified. Purpose: To more thoroughly examine the self-optimization characterization and the consequences of obligating use of the RSF. Methods: Forty-seven individuals of diverse statures completed 3 consecutive days of preferred walking trials on a treadmill where stride rate, stride length, walking speed, heart rate and walking economy measures were made under steady state heart rate conditions. Anthropometric measures were taken to build a hybrid model of the leg and model the RSF. Reliability across days was evaluated via repeated measures analysis of variance (ANOVA) and intra-class correlation (ĂĄ=.05) and correlations were calculated for PSF and RSF. A separate sample of 20 participants walked under 3 conditions, (1) completely preferred; (2) at the original preferred speed using the RSF; and (3) with the option to establish a new preferred speed while using the RSF. Results: Gait characteristics were fundamentally reliable across days and the correlation between PSF and RSF was weak (8% explained variance). Walking economy improved 14% when using the RSF and allowed to self-select the speed / stride length used at that cadence. Conclusions: The results raised slight questions about current self-optimization presumptions and further emphasized the role of resonance in walking economyFaculty Sponsor: Dr. Philip K. Scho
Spirometry Reference Values for Navajo Children Ages 6-14 Years
Summary. Spirometry is the most important tool in diagnosing pulmonary disease and is the most frequently performed pulmonary function test. Since respiratory disease is the single greatest cause for morbidity and mortality on the Navajo Nation, the purpose of this study was to create new age and race-specific pulmonary nomograms for Navajo children. Five hundred fifty-eight healthy children, ages 6-14 years, attending Navajo Nation elementary schools in Arizona, were asked to perform spirometry to develop population-specific and tribe-specific nomograms for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1 Ratio (FEV1/FVC). Spirometry tests from 284 girls and 274 boys met American Thoracic Society quality control standards. Lung function values, except for FEV1/FVC, all increased with height. The lower limit of the normal range for FEV1/FVC was 80%. The spirometry reference equations from the healthy boys and girls were developed. Height and the natural log of height were significant predictors of FEV1, FVC, and FEF 25-75% in the gender-specific models. The resulting population-specific spirometry reference equations should be used when testing Navajo children ages 6-14 years. However, the use of the NHANES III spirometry reference equations for Caucasian children may not result in significant misclassification in clinical settings providing that a maximal effort is given by the Navajo child being tested
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Developing a Functional Food Systems Literacy for Interdisciplinary Dynamic Learning Networks
The impact of human activity on the planet cannot be understated. Food systems are at the centre of a tangled web of interactions affecting all life. They are a complex nexus that directly and indirectly affects, and is affected by, a diverse set of social, environmental and technological phenomena. The complexity and often intractability of these interactions have created a variety of food-related problems that people seek to address in a collaborative and interdisciplinary manner through the adoption of a holistic food systems perspective. However, operationalising a systemic approach to address food system challenges is not a guarantee of success or positive outcomes. This is largely due to the partiality inherent in taking a systems perspective, and the difficulty in communicating these different perspectives among stakeholders. A functional food systems literacy is therefore required to aid people in communicating and collaborating on food system problems within dynamic learning networks. The Interdisciplinary Food Systems Teaching and Learning (IFSTAL) programme has been operating since 2015 as a social learning system to develop a food systems pedagogy with a range of multi-sectoral partners. The findings in this paper arise out of iterative reflexive practice into our teaching approach and delivery methods by former and current staff. In order to foster integrative engagement on food system challenges, we propose and define a functional food systems literacyâa theoretical minimum that can aid diverse stakeholders to explore and intervene in food systems through more effective communication and collaboration. Derived from a reflective analysis of instruments and methods in delivering the IFSTAL programme, we provide a framework that disaggregates functional food systems literacy according to four knowledge types, and includes examples of skills and activities utilised in the IFSTAL programme to support learning in these different domains. We argue that claims to comprehensive food systems knowledge are unrealistic and therefore propose that a functional food systems literacy should focus on providing a means of navigating partial claims to knowledge and uncertainty as well as fostering effective collaboration. We believe that this will enhance the capabilities of stakeholders to work effectively within dynamic learning networks
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Training Future Actors in the Food System: A new collaborative cross-institutional, interdisciplinary training programme for students
There is an urgent need to train a cohort of professionals who can address and resolve the increasing number of fundamental failings in the global food system. The solutions to these systemic failings go far beyond the production of food, and are embedded within broad political, economic, business, social, cultural and environmental contexts. The challenge of developing efficient, socially acceptable and sustainable food systems that meet the demands of a growing global population can only be tackled through an interdisciplinary systems approach that integrates social, economic and environmental dimensions. The new cross-institutional training programme, IFSTAL (Innovative Food Systems Teaching and Learning), is designed to improve post-graduate level knowledge and understanding of food systems from a much broader interdisciplinary perspective, which can be applied to studentsâ own studies. Ultimately, these graduates should be equipped to apply critical interdisciplinary systems thinking in the workplace to understand how problems are connected, their root causes and where critical leverage points might be. This article outlines the programme and presents a review of its first year (2015-2016 academic year)
The conceptualisation of health and disease in veterinary medicine
<p>Abstract</p> <p>Background</p> <p>The concept of health, as well as the concept of disease, is central in veterinary medicine. However, the definitions "health" and "disease" are not generally acknowledged by veterinarians. The aim of this study was to examine how the concepts "health" and "disease" are defined in veterinary textbooks.</p> <p>Methods</p> <p>Veterinary textbooks in several disciplines were investigated, but only textbooks with explicit definitions of the concepts were selected for examination.</p> <p>Results</p> <p>Eighty out of the 500 relevant books within veterinary medicine were written for non-veterinarians. Eight percent of the books had an explicit definition of health and/or disease. More frequently, textbooks written for non veterinarians did have definitions of health or disease, compared to textbooks written for professionals. A division of health definitions in five different categories was suggested, namely:</p> <p>1. Health as normality, 2. Health as biological function, 3. Health as homeostasis, 4. Health as physical and psychological well-being and 5. Health as productivity including reproduction.</p> <p>Conclusion</p> <p>Few veterinary textbooks had any health or disease definition at all. Furthermore, explicit definitions of health stated by the authors seemed to have little impact on how health and disease are handled within the profession. Veterinary medicine would probably gain from theoretical discussions about health and disease.</p
Transformation, adaptation and development: relating concepts to practice
In recent years there has been a growing number of academic reviews discussing the theme of transformation and its association with adaptation to climate change. On the one hand this has stimulated exchange of ideas and perspectives on the parameters of transformation, but it has also given rise to confusion in terms of identifying what constitutes a non-incremental form of adaptation on the ground. What this article aims to do instead is help researchers and practitioners relate different interpretations of transformation to practice by proposing a typological framework for categorising forms of change that focuses on mechanisms and objectives. It then discusses how these categorisations link to the broader conceptions and critiques noted above, with the idea that this will enable those who seek to analyse or plan adaptation to better analyse what types of action are potentially constitutive of transformation. In doing so, it should equally assist in the identification and specification of critical questions that need to be asked of such activity in relation to issues of sustainability and equity. As the term transformation gains ground in discussions of climate change adaptation, it is necessary to take a step back, review quite what commentators mean when they use the word, and consider the implications on people, especially the most vulnerable and marginalised, of âdoingâ or promoting transformation in its different forms
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Here and now: perceptions of Indian Ocean islanders on the climate change and migration nexus
Empirical studies exploring the links between climate change and migration are increasing. Often, perceptions are not fully explored from the people most affected by the climate change and migration nexus. This article contributes to filling this gap by eliciting and analyzing perceptions regarding climate change and migration from an understudied population labelled as being amongst those most immediately and directly affected by climate change: Indian Ocean islanders. Open-ended, semi-structured interviews were conducted in two case study communities in Maldives (Kaafu Guraidhoo with 17 interviews and Raa Dhuvafaaru with 18 interviews) and two case study communities in Lakshadweep, India (Kavaratti with 35 interviews and Minicoy with 26 interviews). The results present the intervieweesâ perceptions of climatic variability and change that they experience; how they perceive the causes of these changes; and links to migration decisions. The interviews demonstrate that perceptions of climate change, of migration, and of the links or lack thereof between the two are centred on the intervieweesâ own experiences, their own locations, and the immediate timeframe. External information and direction has limited influence. Their perceptions are framed as being the âhere and nowâ through topophilia (here) and tempophilia (now). The islandersâ views do not avoid, but rather encompass, long-term livelihoods and the future. Such a future might be in another location, but the anchor is expressing future hopes and aspirations through the here and now. It is not linked to the wide-scale, long-term issue of climate change
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