Matching Items (55)
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Description
Obesity impairs skeletal muscle maintenance and regeneration, a condition that can progressively lead to muscle loss, but the mechanisms behind it are unknown. Muscle is primarily composed of multinucleated cells called myotubes which are derived by the fusion of mononucleated myocytes. A key mediator in this process is the cellular

Obesity impairs skeletal muscle maintenance and regeneration, a condition that can progressively lead to muscle loss, but the mechanisms behind it are unknown. Muscle is primarily composed of multinucleated cells called myotubes which are derived by the fusion of mononucleated myocytes. A key mediator in this process is the cellular fusion protein syncytin-1. This led to the hypothesis that syncytin-1 could be decreased in the muscle of obese/insulin resistant individuals. In contrast, it was found that obese/insulin resistant subjects had higher syncytin-1 expression in the muscle compared to that of the lean subjects. Across the subjects, syncytin-1 correlated significantly with body mass index, percent body fat, blood glucose and HbA1c levels, insulin sensitivity and muscle protein fractional synthesis rate. The concentrations of specific plasma fatty acids, such as the saturated fatty acid (palmitate) and monounsaturated fatty acid (oleate) are known to be altered in obese/insulin resistant humans, and also to influence the protein synthesis in muscle. Therefore, it was evaluated that the effects of palmitate and oleate on syncytin-1 expression, as well as 4E-BP1 phosphorylation, a key mechanism regulating muscle protein synthesis in insulin stimulated C2C12 myotubes. The results showed that treatment with 20 nM insulin, 300 µM oleate, 300 µM oleate +20 nM insulin and 300 µM palmitate + 300 µM oleate elevated 4E-BP1 phosphorylation. At the same time, 20 nM insulin, 300 µM palmitate, 300 µM oleate + 20 nM insulin and 300 µM palmitate + 300 µM oleate elevated syncytin-1 expression. Insulin stimulated muscle syncytin-1 expression and 4E-BP1 phosphorylation, and this effect was comparable to that observed in the presence of oleate alone. However, the presence of palmitate + oleate diminished the stimulatory effect of insulin on muscle syncytin-1 expression and 4E-BP1 phosphorylation. These findings indicate oleate but not palmitate increased total 4E-BP1 phosphorylation regardless of insulin and the presence of palmitate in insulin mediated C2C12 cells. The presence of palmitate inhibited the upregulation of total 4EB-P1 phosphorylation. Palmitate but not oleate increased syncytin-1 expression in insulin mediated C2C12 myotubes. It is possible that chronic hyperinsulinemia in obesity and/or elevated levels of fatty acids such as palmitate in plasma could have contributed to syncytin-1 overexpression and decreased muscle protein fractional synthesis rate in obese/insulin resistant human muscle.
ContributorsRavichandran, Jayachandran (Author) / Katsanos, Christos (Thesis advisor) / Coletta, Dawn (Committee member) / Dickinson, Jared (Committee member) / Arizona State University (Publisher)
Created2017
Description
Sustainable purchasing has become and increasingly salient way by which local governments can decrease their resource consumptions, while also addressing broader climate action goals. Successfully implemented sustainable purchasing policies have the potential to reduce consumption and waste, expand green purchasing markets, and catalyze spillover benefits such as financial savings. Furthermore,

Sustainable purchasing has become and increasingly salient way by which local governments can decrease their resource consumptions, while also addressing broader climate action goals. Successfully implemented sustainable purchasing policies have the potential to reduce consumption and waste, expand green purchasing markets, and catalyze spillover benefits such as financial savings. Furthermore, city-level actions have become increasingly significant as the federal government ceases critical climate research and pulls out of collaborative climate deals (i.e. The Paris Climate Accord). Using data from the Sustainable Purchasing Researching Initiative at Arizona State University’s Center for Organization Research and Design, as well as qualitative policy analyses, the author investigates the elements of a city’s sustainable purchasing policy (SPP) that are related to its implementation success. Furthermore, the author compares these initial findings to the case study of Phoenix, AZ where she explores whether these elements are also present in the City of Phoenix’s sustainable purchasing policy. The author finds that six key policy elements are generally associated with higher SPP implementation success rates — mandatory requirements, accountability, multi-level governance, vendors requirements, advocacy, and continual improvement. While additional policy elements undoubtedly play a role in the successful implementation of a SPP, the author concludes cities that incorporate these specific elements are better positioned for successful and sustainable implementation. Conclusions further show that the City of Phoenix’s 2007 EPP contained only two of these policy elements. As a result of this project and the author’s work with the City, the 2017 revised SPP incorporates all six policy elements.
ContributorsBurwell, Caitlin (Author) / Darnall, Nicole (Contributor) / Schoon, Michael (Contributor)
Created2017-12-01
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Description

Adaptive comanagement endeavors to increase knowledge and responsiveness in the face of uncertainty and complexity. However, when collaboration between agency and nonagency stakeholders is mandated, rigid institutions may hinder participation and ecological outcomes. In this case study we analyzed qualitative data to understand how participants perceive strengths and challenges within

Adaptive comanagement endeavors to increase knowledge and responsiveness in the face of uncertainty and complexity. However, when collaboration between agency and nonagency stakeholders is mandated, rigid institutions may hinder participation and ecological outcomes. In this case study we analyzed qualitative data to understand how participants perceive strengths and challenges within an emerging adaptive comanagement in the Agua Fria Watershed in Arizona, USA that utilizes insight and personnel from a long-enduring comanagement project, Las Cienegas. Our work demonstrates that general lessons and approaches from one project may be transferable, but particular institutions, management structures, or projects must be place-specific. As public agencies establish and expand governance networks throughout the western United States, our case study has shed light on how to maintain a shared vision and momentum within an inherently murky and shared decision-making environment.

ContributorsChilds, Cameron (Author) / York, Abigail (Author) / White, Dave (Author) / Schoon, Michael (Author) / Bodner, Gitanjali S. (Author) / Julie Ann Wrigley Global Institute of Sustainability (Contributor)
Created2013
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Description

Our previous studies show reduced abundance of the β-subunit of mitochondrial H+-ATP synthase (β-F1-ATPase) in skeletal muscle of obese individuals. The β-F1-ATPase forms the catalytic core of the ATP synthase, and it is critical for ATP production in muscle. The mechanism(s) impairing β-F1-ATPase metabolism in obesity, however, are not completely

Our previous studies show reduced abundance of the β-subunit of mitochondrial H+-ATP synthase (β-F1-ATPase) in skeletal muscle of obese individuals. The β-F1-ATPase forms the catalytic core of the ATP synthase, and it is critical for ATP production in muscle. The mechanism(s) impairing β-F1-ATPase metabolism in obesity, however, are not completely understood. First, we studied total muscle protein synthesis and the translation efficiency of β-F1-ATPase in obese (BMI, 36±1 kg/m2) and lean (BMI, 22±1 kg/m2) subjects. Both total protein synthesis (0.044±0.006 vs 0.066±0.006%·h-1) and translation efficiency of β-F1-ATPase (0.0031±0.0007 vs 0.0073±0.0004) were lower in muscle from the obese subjects when compared to the lean controls (P<0.05). We then evaluated these same responses in a primary cell culture model, and tested the specific hypothesis that circulating non-esterified fatty acids (NEFA) in obesity play a role in the responses observed in humans. The findings on total protein synthesis and translation efficiency of β-F1-ATPase in primary myotubes cultured from a lean subject, and after exposure to NEFA extracted from serum of an obese subject, were similar to those obtained in humans. Among candidate microRNAs (i.e., non-coding RNAs regulating gene expression), we identified miR-127-5p in preventing the production of β-F1-ATPase. Muscle expression of miR-127-5p negatively correlated with β-F1-ATPase protein translation efficiency in humans (r = – 0.6744; P<0.01), and could be modeled in vitro by prolonged exposure of primary myotubes derived from the lean subject to NEFA extracted from the obese subject. On the other hand, locked nucleic acid inhibitor synthesized to target miR-127-5p significantly increased β-F1-ATPase translation efficiency in myotubes (0.6±0.1 vs 1.3±0.3, in control vs exposure to 50 nM inhibitor; P<0.05). Our experiments implicate circulating NEFA in obesity in suppressing muscle protein metabolism, and establish impaired β-F1-ATPase translation as an important consequence of obesity.

ContributorsTran, Lee (Author) / Hanavan, Paul (Author) / Campbell, Latoya (Author) / De Filippis, Elena (Author) / Lake, Douglas (Author) / Coletta, Dawn (Author) / Roust, Lori R. (Author) / Mandarino, Lawrence (Author) / Carroll, Chad C. (Author) / Katsanos, Christos (Author) / College of Health Solutions (Contributor)
Created2016-08-17
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Description
Collaborative research is not only a form of social and human capital and a public good, but also a fundamental elicitor of positive Collective Action. Collaborative Research Networks can serve as models of proactive and purposive Collective Action and catalysts of societal change, if they function as more than hubs

Collaborative research is not only a form of social and human capital and a public good, but also a fundamental elicitor of positive Collective Action. Collaborative Research Networks can serve as models of proactive and purposive Collective Action and catalysts of societal change, if they function as more than hubs of research and knowledge. It is the goal of this Honors Thesis to examine the current nature under which collaborative research networks, focused on matters of Global Health or Sustainability, operate., how they are organized, what type of collaboration they engage in, and who collaborates with whom. A better understanding of these types of networks can lead to the formation of more effective networks that can develop innovative solutions to our collective Global Health and Sustainability problems.
ContributorsHodzic, Mirna (Author) / Van Der Leeuw, Sander (Thesis director) / Janssen, Marco (Committee member) / Schoon, Michael (Committee member) / Barrett, The Honors College (Contributor)
Created2012-05