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- All Subjects: Biology
- Creators: Arizona State University
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 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
The purpose of this study was to investigate the relationship between the structures of nonprofit victim service organizations and organizational effectiveness. Past research has rarely considered the structures of nonprofit institutions, and thus there is a lack of understanding regarding how nonprofit service organizations function, and whether not traditional concepts of effectiveness can accurately describe organizational success. Thus, there is an opportunity for further exploration regarding how this structural change impacted organizational effectiveness. This study used mixed-methodology including surveys (N=16), interviews (N=17), and comparative case studies (N=5) to examine nonprofit organizational structures and effectiveness in efforts to answer questions regarding the reality of hybrid nonprofit structures, the characteristics of these hybrid structures, and the presentation of organizational effectiveness in nonprofit service organizations. The findings revealed that a) hybrid structures are overwhelmingly the style of service nonprofits, b) externally bureaucratic structures and collective internal structures are combined to form these hybrid organizations, and c) traditional measures of organizational effectiveness as well as characteristics unique to hybrid structures are influential in determining effectiveness in nonprofit service organizations. Future research should consider what factors influence the collaboration of nonprofit service organizations and criminal justice institutions in order to best support crime victims.
ContributorsVerhagen, Megan (Author) / Holtfreter, Kristy (Thesis advisor) / Fox, Kate (Committee member) / Messing, Jill (Committee member) / Arizona State University (Publisher)
Created2018
Description
Interpersonal racial discrimination is positively associated with poor mental health outcomes in a number of marginalized groups across the United States (Brondolo, et al., 2008). This paper examines how racial discrimination affects the self-esteem, self-worth, and racial pride of Latinas using interview data from a purposive sample of students. The objectives of this study are: (a) to better understand the effects of racial microaggressions on young Latinas’ construction of self, (b) to explicate how these self-perceptions influence deviant behavior and maladaptive thought processes, drawing on strain and discrimination literatures, and (c) to examine the protective mechanisms Latinas employ with friends and family as a response to racial discrimination. Findings indicated that respondents experienced racial discrimination through a variety of channels, from negative stereotypes to feeling a distinct prejudice in academic settings. Participants utilized numerous coping mechanisms to deal with such encounters, most of which emphasized the importance of drawing strength from Hispanic values, culture, and language during times of adversity.
ContributorsBarstow, Callie Elizabeth (Author) / Burt, Callie (Thesis advisor) / Decker, Scott (Committee member) / Wang, Xia (Committee member) / Arizona State University (Publisher)
Created2015
Description
Intelligence, consisting of critical products that facilitate law enforcement decision-making, is a crucial component and tool in the criminal justice system. However, the ways in which intelligence is gathered and used has gone largely unevaluated, particularly at the local level of law enforcement. This thesis begins to address the sparsity of literature by investigating the Intelligence Officer function in the Phoenix Police Department. More specifically, this study explores their roles; perceptions on information they are gathering, namely reliability and validity; and their effectiveness in terms of both intelligence and case successes. Different aspects of roles and perceptions are also examined in terms of their ability to predict these outcomes. Data reflect a 22-month sample of officer reports from the Phoenix Police Department Intelligence Officer Program. Descriptive analyses suggest that Intelligence Officers typically work specific cases with varied and different natures of crime. Generally, officers seem to be confident in the information they collect in terms of reliability and validity, and also appear to be relatively successful in achieving both broad intelligence successes and more tangible case successes. However, the relationships between role and perception variables and results vary in terms of both impact and significance for each type of success. Future research is required to better understand these relationships and to continue building a foundation of knowledge on Intelligence Officer effectiveness, so their impact can be optimized.
ContributorsBottema, A. Johannes (Author) / Telep, Cody (Thesis advisor) / Terrill, William (Committee member) / Young, Jacob (Committee member) / Arizona State University (Publisher)
Created2017