As social media have become a ubiquitous part of our daily life, questions remained to be answered by scholars who study social movements and new communication technology. This dissertation explores the role and impact of Facebook as it pertains to the food movement in the United States. Applying three main theories derived from communication and sociology, this manuscript explores the usage of Facebook among ordinary citizens who take leadership roles to make a social difference at the policy level. Taking as a case study the Right to Know Rally, through a qualitative content analysis of all posts of the 42 Facebook pages of the Right to Know Rally, as well as interviews with selected participants of the event, this dissertation attempts to answer three main questions. First, through the lens of Habermas's concept of the public sphere this manuscript addresses whether Facebook reinforces or challenge the notion of the public sphere. Second, Castells's work of network analysis serves to understand how virtual relations affect a movement both online and offline. Third, applying leadership theories, this study explores how leadership is manifested on Facebook and who takes the lead both online and offline. Last chapter explores a question that has been at the center of many debates among scholars who are studying new communication technology. Does Facebook offer a bridge to civic engagement offline? I argued that while Facebook poses problems for the privacy of an individual, its power lies in the functionality of reaching heterogeneous networks made out of individuals who might or might not being part of the Right to Know Rally movement. In lack of physical spaces to express freedom of speech, Facebook reinforces Habermas's notion of the public sphere, in which individuals from the comfort of their home can pitch in, taking at times leading roles. In this way new leaders emerge. These people do not have to possess a priori experience in social movements, but they do need to be active participants of the web and offline. In terms of the impact of Facebook on online settings, while this study cannot generalize its finding, it was blatant during the analysis that the social medium has an effect on offline mobilization. More specifically, Facebook expands social networks outside the realm of the web, through the function of event planning. These event attracted bystanders who were encouraged to visit the web to find further information and take action. / A Dissertation submitted to the School of Communication in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2012. / October 12, 2012. / Facebook, GMOs, social media, Social movements, social networks / Includes bibliographical references. / Andrew Opel, Professor Directing Dissertation; Jennifer Proffitt, Committee Member; Jeanette Castillo, Committee Member.

In the public spaces of New Orleans, street musicians construct soundmarks, or sonic landmarks, in the locations where they commonly perform. The maintenance and preservation of New Orleans music is often achieved through performance processes by musicians in these spaces who exist as sonic fixtures (residents) and drifting buskers (migrants) in heavily trafficked areas of the city, most notably the French Quarter. This street music circulates and amalgamates the music of New Orleans with that of other cultures, often creating unique hybrid genres and neo-traditional styles. In addition to drawing from this hybridity, my thesis will address performers' relationships to each other, and music in urban geography, tourism, and migrant communities. Ultimately, by mapping soundmarks I converse with this enigmatic musical community and those vested in it, which results in the recognition of distinctive hotspots of outdoor musical activity in the French Quarter. Landmarks in this and other cities are often demarcated as distinguishing features in the landscape that function to guide tourists, and act as tourist attractions themselves. This thesis will map and investigate eight of these sonic landmarks and document the presence and experiences of the street musicians who construct them. I argue that in New Orleans landmarks and soundmarks are synonymous. I hope to expand the current scholarly awareness of New Orleans music outside the exploitation of jazz, and to urge for the inclusion of music making on urban streets in ethnomusicological discourse. This thesis is divided into six sections. The introductory chapter provides a contextualization of the French Quarter as it relates to this topic as well as associated literature. The second chapter reveals my theoretical framework, defines my appropriation of "soundmark," and discusses the relationship of music to place as illustrated with an example of battling brass bands. The third chapter sets the stage for busking with a discussion of locale, architecture, and city ordinances. Chapter Four builds upon the knowledge of what it is like to be a busker in New Orleans. Chapter Five harbors the data gleaned from a summer and several autumn/winter weekends worth of fieldwork, designating the location and broad description of eight soundmarks as mapped 10 throughout the French Quarter. This chapter also contextualizes the impact of each soundmark as relative to the individual performers that construct it, and its relationship to the surrounding environment. The concluding chapter offers a summary and my reflexive responses to this project while delving into the relationship of buskers to the community around them. I finish by elaborating on the potential implications of mapping soundmarks, including ideas for the future use of this research. In sum, this project represents an ethnomusicological case study of musicians existing on the streets of New Orleans between May of 2011 to February of 2012 while addressing larger issues on the relationship between these musicians, their shared public space, and the community they represent. / A Thesis submitted to the College of Music in partial fulfillment of the requirements for the degree of Master of Music. / Summer Semester, 2012. / June 13, 2012. / Busking, French Quarter, New Orleans, R. Murray Schafer, Soundmarks, Street Musicians / Includes bibliographical references. / Frank Gunderson, Professor Directing Thesis; Michael B. Bakan, Committee Member; Charles Brewer, Committee Member.

Despite the attractive properties of advanced ceramics, they are not popular for structural applications even though they possess high strength. Their low fracture toughness and brittle fracture mode are unwelcome for high integrity structure. Moreover, they fail at loads far below their theoretical strengths due to their inherent flaws. These have led to the development of reinforcing strategies to help enhance the fracture resistance of ceramics. However, reported strengths value are still far below theoretical strength, most reinforced ceramics suffer trade-off between strength and toughness, and most present reinforcement methods are material specific. In this work, a generic method for reinforcing ceramic materials for the enhancement of fracture resistance is described. Continuous ductile ligaments oriented in two orthogonal directions and forming 2-D network grid reinforcement structure was employed. The method involves two major stages: fabrication of regular channels in 2-D in ceramic matrix to form the preform and infiltration of the preform with the required reinforcement. Two different materials: carbon fibers and soft metal alloys were used as sacrificial materials for fabricating the aligned 2-D regular channels in alumina matrix. After the porous preforms were formed, molten aluminum alloys were infiltrated into the channels by the application of mechanical pressure, and this completes the composite fabrication process. Mechanical tests show that some porous preforms having area fraction of 2.7 % exhibited 27 % higher flexural strength than the solid specimens despite the porosity contained and this has been attributed to the ability of the channels to reduce the population and distribution of cracks in the porous material. The reinforced composites were also subjected to mechanical tests which revealed 217.6 % enhancement in flexural strength for the 7.79 % Al 7075 alloy reinforced composite. This magnitude of property enhancement was achieved due to the confinement of the matrix in the loop of the reinforcement and the beneficial residual compressive stress generated as a result of the difference in coefficient of thermal expansion (CTE) of the alumina and aluminum. The residual compressive stress delays crack initiation and crack propagation in the alumina matrix. It also reduces the stress concentration factor in the matrix, leading to higher failure stress and higher fracture toughness. / A Dissertation submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / February 17, 2012. / Composite, Fracture Strength, Fracture Toughness, Reinforcement, Residual Stress, Stress Cocentration / Includes bibliographical references. / Okenwa Okoli, Professor Directing Dissertation; Simone Peterson-Hruda, University Representative; Mei Zhang, Committee Member; Zhiyong Richard Liang, Committee Member.

Little is known regarding the mechanisms underlying the neurobiological consequences of antidepressant exposure during adolescence. Therefore, in this dissertation, I assessed the long-lasting effects of adolescent exposure to Fluoxetine (FLX), a selective serotonin reuptake inhibitor, on behavioral reactivity to emotion-eliciting stimuli in adulthood using rodent animal models. To do this, in chapters two and three, male Sprague-Dawley rats and c57BL/6 mice are exposed to FLX throughout adolescence (postnatal days 35-49), and tested in adulthood (postnatal day 70+) on a battery of behavioral tasks designed to assess sensitivity to stress- (i.e., forced swimming and the social defeat procedure), and anxiety-inducing situations (i.e., elevated plus-maze, novelty induced hypophagia, and open field test). Because a proposed mechanism by which FLX exerts its therapeutic effect(s) has been linked to the modulation of intracellular signaling pathways involved in the regulation of cell survival, in chapter three, I also assessed how FLX exposure influenced extracellular signal-regulated protein kinase 1/2 (ERK)-signaling within the ventral tegmental area (VTA) of the midbrain. The VTA was selected given the role this brain region plays in regulating mood and motivation under normal conditions. FLX exposure during adolescence resulted in an enduring paradoxical behavioral response in which rodents exhibit a stress-resistant behavioral phenotype, along an increase in sensitivity to anxiety-inducing situations. In addition, a persistent decrease in ERK-related signaling was observed within the VTA of rats and mice exposed to FLX. Given that chronic exposure to FLX resulted in an enduring downregulation of ERK signaling, it was imperative to determine whether exposure to stress, a major predisposing factor for depression, would result in oppositional regulation of this signaling pathway. Thus, in chapters three and four I assessed the behavioral and biochemical effects of exposure to stress in adult rats and mice using complementary behavioral, molecular, and gene transfer approaches. Here, exposure to chronic unpredictable stress resulted in depressive-like phenotypes, including a reduced ability to experience pleasure (i.e., anhedonia, as inferred from the sucrose preference test) and increased vulnerability to subsequent stress (i.e., forced swim test and the social defeat procedure). This stress-induced behavioral profile was also accompanied by an increase in ERK and its related signaling within the VTA - biochemical results opposite to those observed after FLX exposure. The functional significance of this oppositional effect was further confirmed using viral vectors: increasing ERK activity within the VTA increased sensitivity, whereas decreasing ERK resulted in decreased sensitivity to stress. Together, the data presented in this dissertation strongly implicate ERK signaling within the VTA as a modulator of behavioral responsivity to stress and antidepressant efficacy in adolescent and adult rodents. Lastly, in chapter five, the potential clinical implications, as well as future directions of this work are discussed. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / September 2, 2011. / adolescence, anxiety, ERK, fluoxetine, major depression, ventral tegmental area / Includes bibliographical references. / Carlos A. Bolaños-Guzmán, Professor Directing Dissertation; Akash Gunjan, University Representative; Zuoxin Wang, Committee Member; Mohamed Kabbaj, Committee Member; Janet Kistner, Committee Member.

Relations between stimuli (contingencies, dependencies, etc.) provide valuable information about regularities and uncertainties in the environment. Statistical and associative mechanisms thought to be responsible for learning such information are commonly assumed to be passive and automatic. The feasibility of such learning mechanisms is questionable, however, because the magnitude of the possible associative links exceeds the neurological potential for stimulus relation encoding. Constraints are needed to limit learning processes to profitable stimulus information. The current research explores two such constraints. The first one yields successful learning of a relation between stimuli only when they are actively co-processed in a manner that adjoins them, for example, by means of a comparison. Secondly, relations between stimuli are better learned when they or (some of) their features are relevant to completing a goal directed task. These constraints provide and powerful and effective means to demarcate target information for learning processes. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / March 30, 2012. / Associative Learning, Selective Attention, Statistical Learning / Includes bibliographical references. / Michael P. Kaschak, Professor Directing Dissertation; Bruce M. Menchetti, University Representative; Colleen M. Kelley, Committee Member; Walter R. Boot, Committee Member; Carol M. Connor, Committee Member.

The effect of controlled isothermal crystallization conditions on the final crystalline structure of a set of polyethylenes with precise Cl substitution on each and every 9th, 15th, 19th and 21st backbone carbons was assessed. Isothermally crystallized samples display a drastic change in their crystalline structure in a narrow range of crystallization temperatures. The structural change occurs within an undercooling difference of one degree and is revealed by a sharp increase in melting temperature, an increase in TG conformers and a decrease in SAXS periodicity. These changes are associated with a different distribution of Cl atoms in the crystallites. Under rapid crystallization conditions (Form I structure develops), the Cl distribution in the crystallites is disordered; whereas slower crystallization kinetics leads to staggering of chlorines and formation of a herringbone structure in the crystallites (Form II structure). Differences in nucleation mode between both types of structures were determined from the analysis of the crystallization kinetics according to nucleation theory. The drastic change in morphology correlates with the selection of the critical segment length required to form a stable nucleus. The length of the initial nucleus is governed by kinetics; when this length approaches the distance between halogens, Form II develops and folding is preferential at the substitution point. Shorter nuclei end in development of the Form I structure which has chains that fold at a random position along the methylenic chain. Controlling the crystallization kinetics in novel polyolefins of this nature allows strategies for producing materials with different properties attained by directing the crystallization process to preferentially Form I or rather to Form II structures. / A Thesis submitted to the Department of Chemical and Biomedical Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester, 2012. / November 29, 2011. / chlorine, crystallization, halogen, polyethylene, precise, substitution / Includes bibliographical references. / Rufina G. Alamo, Professor Directing Thesis; Subramanian Ramakrishnan, Committee Member; Theo M. Siegrist, Committee Member.

Using a political economic perspective, this thesis examines how organized labor is covered in the corporate-owned media by analyzing coverage of the 2011 NBA lockout. Based on scholarly research by Schmidt (1993), Bruno (2008) and others, it is clear that media coverage of organized labor is declining in both quantity and quality. The little coverage that exists tends to focus on labor-management conflict, with the high-profile world of sport attracting greater media attention than other industries. This conflict-oriented coverage takes on several distinct characteristics, as identified by scholars Martin (2004), Parenti (1993) and Puette (1992). Among these trends are greater scrutiny of employee salaries rather than those of management, coverage that emphasizes management `offers' rather than union givebacks, and the use of a third-party, `consumerist' perspective that allows the media to appear objective while espousing management viewpoints. Newspaper articles and television transcripts concerning the NBA lockout were examined, including The New York Times, The Associated Press, The Wall Street Journal, ABC News, CBS News, and PBS. The thesis finds that lockout coverage in the media outlets analyzed was largely consistent with the literature, with some exceptions. In particular, the Times and the AP offered in-depth coverage of player concessions. In addition, publicly-owned PBS provided greater context and criticism of owner positions than any of the privately-owned media outlets. / A Thesis submitted to the School of Communication in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester, 2012. / June 22, 2012. / Corporations, Journalism, Labor, Media, Political economy, Sports / Includes bibliographical references. / Jennifer M. Proffitt, Professor Directing Thesis; Davis W. Houck, Committee Member; Joshua I. Newman, Committee Member.

Evidence from epidemiological studies indicates that the incidence of cardiovascular morbidity and mortality peaks during the winter months. In fact, cold temperatures have been implicated as the putative factor associated with increased risk of hypertension as well as adverse cardiovascular events such as myocardial infarction, stroke, and fatal arrhythmias. In addition, exposure to cold temperatures ( PURPOSE: The aim of this proposed study was twofold 1) to evaluate the acute BP, wave refection (augmentation index, AIx), and cardiac autonomic responses during cold exposure with concurrent isometric exercise, and 2) to examine the effects of a 14-day course of L-cit supplementation on BP, arterial stiffness, wave reflection, and cardiac autonomic modulation during acute cold exposure at rest and during isometric exercise. We hypothesized that L-cit supplementation would reduce the BP, wave reflection, and cardiac sympathetic activity to cold exposure and isometric handgrip exercise (IHG). METHODS: In a crossover randomized fashion, 20 healthy young (23 ± 3 yr.) male participants volunteered for this study. Subjects were instructed to assume the supine position for 30 min inside an environmental chamber at cold (4ºC) or temperate ( temp,24ºC) conditions. Radial waveforms and heart rate variability (HRV) were obtained by means of applanation tonometry and heart rate monitor respectively. After 5 min of rest (RES) measurements the participants were asked to perform a 3 min IHG at 30% of their maximal voluntary contraction followed by a 3 min recovery (REC) period. After baseline measurements, subjects were assigned to either a Placebo (Maltodextrin, PL) or L-cit group for 14 days followed by 14 days of washout period, and 14 days of the second treatment. Cardiovascular function was evaluated during both cold and temp conditions before the first supplementation period, thereafter cardiovascular function was evaluated after 14 days of the first treatment, 14 days of washout period, and 14 days of a second treatment at 4ºC only. RESULTS: Height, weight, body mass index, and waist circumference were 1.77 ± 0.01 m, 84.7 ± 3.12 kg, 27.1 ± 1.0 kg/m2, and 88.5 ± 2.9 cm respectively. All 20 participants completed the experiments for the acute responses to cold versus temp and 16 completed the supplementation intervention (two dropped for personal reasons and two were not interested in participating in the intervention). Both, brachial systolic BP (BSBP) and aortic systolic BP (ASBP) were higher (P CONCLUSIONS: To our knowledge this is the first report showing hemodynamic responses to IHG during whole-body cold exposure and the effects of short-term after L-cit supplementation on these responses. These findings suggest that cold exposure imposes an additional increase in AIx and ΔEw during exercise that may ultimately lead to an attenuated cardiac vagal reactivation and sympathetic withdrawal after acute exercise. In addition, we demostarted that L-cit supplementation is an effective means to decrease the cold induced hypertensive responses and ΔEw at RES and REC, but not during IHG. In conclusion, L-cit supplementation may be a feasible adjuvant treatment to decrease the cold induced hypertensive response and ultimately provide cardioprotection in those exposed to low ambient temperature conditions. Further research is warranted in order to evaluate the effects of cold exposure and exercise in populations at increased cardiovascular risk. / A Dissertation submitted to the Department of Nutrition, Food and Exercise Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2012. / March 16, 2012. / blood pressure, cold exposure, heart rate variability, isometric exercise, L-citrulline, wave reflection / Includes bibliographical references. / Arturo Figueroa, Professor Directing Dissertation; Michael Overton, University Representative; Michael Ormsbee, Committee Member; Jeong-Su Kim, Committee Member.

This thesis explores two regional offshoots of the annual Burning Man Festival in Nevada (Burns)--Ohio's Scorched Nuts and Georgia's Euphoria--by examining how, through performance and play activities in these temporary festival settings, participants may form with one another deep, communal relationships evocative of Victor Turner's concept of communitas. Combining theoretical reading, field research, and participant interviews, it discusses the political potential of these relationships as well as the way that participant theatricality and festival dramaturgies contribute to their construction. The thesis begins by considering general effects that attending a festival in which people must remain inside the premises over a series of days (a "lived-in" festival) might have on participants' ability to engage with others in intimate, intersubjective encounters. It then outlines the "official activities" of Euphoria and Scorched Nuts--those activities orchestrated by event organizers and which involve all or essentially all who enter the grounds--and shows how these activities create distinct overarching dramaturgies for each festival that establish commonalities between participants and energize them to socialize with one another. Finally, it examines case studies of Scorched Nuts' unofficial activities--those orchestrated by participants, rather than organizers, and generally involving only a few people at a time--proposing that these activities are the primary sites where communitas arises in a festival setting. / A Thesis submitted to the School of Theatre in partial fulfillment of the requirements for the degree of Master of Arts. / Summer Semester, 2012. / April 25, 2012. / Burning Man, Burns, Community, Festival / Includes bibliographical references. / Elizabeth Osborne, Professor Directing Thesis; Mary Karen Dahl, Committee Member; Krzystof Salata, Committee Member.

The use of gas chromatography-mass spectrometry to measure the relative pool size and 13C-enrichment of a broad range of intracellular metabolites to monitor changes in the metabolome of mammalian cells is described. The typical workflow for metabolomics and 13C-tracer investigations is discussed and each step optimized to increase the breadth and intensity of detected metabolites, reproducibility of measured metabolite concentrations, sample throughput, and automation of mass isotopomer and multivariate statistical analyses of the data. The protocols developed and optimized in this dissertation allow for the combination of complementary metabolomic and pathway activity data to provide a more comprehensive analysis of the system's metabolic phenotype under the condition(s) being investigated. The utility of the presented protocols were then evaluated by studying the metabolic profiles of two separate cultured human cell lines under various microenvironmental conditions. The first demonstration of the utility of our protocols for combining gas chromatography-mass spectrometry-based metabolomics and 13C-glucose tracer studies was used to correlate shifts in the central carbon metabolism of human embryonic kidney 293 cells with gold nanoparticle exposure. Prior to our studies, little was known about the metabolic perturbations associated with gold nanoparticle uptake. We discovered that gold nanoparticles modulate lipid metabolism in human embryonic kidney 293 cells while having no apparent effect on the glycolytic flux into the pentose phosphate pathway or the tricarboxylic acid cycle. We discuss the significance of these findings and propose possible reasons for the observed metabolic changes. In the second application of our methodologies, we monitored glucose and mitochondrial metabolism of human embryonic stem cells under ambient and reduced oxygen availability. We demonstrated a decoupling of glycolysis and the TCA without any change in the rate of lactate synthesis under reduced oxygen tension. Our results also suggest that alanine and glutaminolysis potentially play significant roles in the adaptation of human embryonic stem cells to reduced oxygen availability. As in the first demonstration, we discuss the biological relevancy of these findings and propose reasons for the observed metabolic changes. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / July 19, 2011. / Includes bibliographical references. / Timothy Logan, Professor Directing Dissertation; P. Bryant Chase, University Representative; Brian Miller, Committee Member; Michael Roper, Committee Member.