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- Genre: Doctoral Dissertation
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Description
This study drew upon a bioecological framework to empirically investigate the relations between environmental chaos and preschoolers' language across time, including the potentially mediating roles of children's effortful control and parenting. Child sex also was examined as a moderator of these relations. For this study, the following data were collected at 30, 42, and 54 months of age. Household chaos and (at 30 months) socioeconomic status (SES) were reported by mothers. Children's effortful control (EC) was rated by mothers and nonparental caregivers, and was observed during a number of laboratory tasks. Maternal vocalizations were assessed during free play sessions with their children (at 30 and 42 months), and supportive and unsupportive parenting behaviors and affect were observed during free play and teaching tasks at each age. Mothers also reported on their own reactions to children's negative emotions. Finally, (at 54 months) children's expressive and receptive language was measured with a standard assessment. Structural equation modeling and path analyses indicated that SES at 30 months and greater levels of household chaos at 42 months predicted not only poorer language skills, but also deficits in children's EC and less supportive parenting in low-income mothers at 54 months, even when controlling for stability in these constructs. Children's effortful control at 42 months, but not parenting, positively predicted later language, suggesting that EC may play a mediating role in the relations between household chaos, as well as SES, and preschoolers' language abilities. Child sex did not moderate the pattern of relations. Post-hoc analyses also indicated that the negative relation between chaos and language was significant only for children who had low EC at 42 months. This study represents a much-needed addition to the currently limited longitudinal research examining environmental chaos and children's developmental outcomes. Importantly, findings from this study elucidate an important process underlying the links between chaos and children's language development, which can inform interventions and policies designed to support families and children living in chaotic home environments.
ContributorsGaertner, Bridget Maria (Author) / Spinrad, Tracy L. (Thesis advisor) / Eisenberg, Nancy (Committee member) / Hanish, Laura (Committee member) / Bradley, Robert (Committee member) / Arizona State University (Publisher)
Created2012
Description
Over the past decade, several high-value proteins have been produced using plant-based transient expression systems. However, these studies exposed some limitations that must be overcome to allow plant expression systems to reach their full potential. These limitations are the low level of recombinant protein accumulation achieved in some cases, and lack of efficient co-expression vectors for the production of multi-protein complexes. This study report that tobacco Extensin (Ext) gene 3' untranslated region (UTR) can be broadly used to enhance recombinant protein expression in plants. Extensin is the hydroxyproline-rich glycoprotein that constitutes the major protein component of cell walls. Using transient expression, it was found that the Ext 3' UTR increases recombinant protein expression up to 13.5- and 6-fold in non-replicating and replicating vector systems, respectively, compared to previously established terminators. Enhanced protein accumulation was correlated with increased mRNA levels associated with reduction in read-through transcription. Regions of Ext 3' UTR essential for maximum gene expression included a poly-purine sequence used as a major poly-adenylation site. Furthermore, modified bean yellow dwarf virus (BeYDV)-based vectors designed to allow co-expression of multiple recombinant genes were constructed and tested for their performance in driving transient expression in plants. Robust co-expression and assembly of heavy and light chains of the anti-Ebola virus monoclonal antibody 6D8, as well as E. coli heat-labile toxin (LT) were achieved with the modified vectors. The simultaneous co-expression of three fluoroproteins using the single replicon, triple cassette is demonstrated by confocal microscopy. In conclusion, this study provides an excellent tool for rapid, cost-effective, large-scale manufacturing of recombinant proteins for use in medicine and industry.
ContributorsRosenthal, Sun Hee (Author) / Mason, Hugh (Thesis advisor) / Mor, Tsafrir (Committee member) / Chang, Yung (Committee member) / Arntzen, Charles (Committee member) / Arizona State University (Publisher)
Created2012
Description
More than simply a source of income, work has become a central source of identity (Beder, 2000; Ciulla, 2000; Clair, McConnell, Bell, Hackbarth & Mathes, 2008; Muirhead, 2004). motivating scholars to engage in a plethora of studies examining the impact of work as a way of defining ourselves, ranging from identification with the organization (Scott, Corman, & Cheney, 1998) to the influence of work on non-work lives (Kirby, Wieland & McBride, 2006). And yet, in such volatile political and economic times, individual's identities as worker are threatened, spurring questions about how to decenter the meaning of work in our lives (Rushkoff, 2011). Despite young people's roles as organizational members, few communication scholars have considered the organizational experiences of youth as a productive area for research and theory (for exception see Myers & Sadaghiani, 2010). I adopt a discursive approach to unpack the multiple ways that discourses, at interpersonal, organizational and social levels, impact and influence youths' identity construction process (Ashcraft & Mumby, 2004; Fairhust & Putnam, 2004). I empirically demonstrate how discourses of work operate simultaneously at multiple levels, interacting and overlapping to position youth as workers. Analysis is based on interviews with youth, ages 12 to 21, participating in a popular national nonprofit organization that serves over four million youth each year. In addition to 49 one-on-one formal interviews, I observed 50 hours of a worker preparation program, which serves as an important context for priming participants and situating our conversations about work. Practically, this project illustrates the influence of organizations to mediate the relationship between discourse and identity. Methodologically, I further clarify discursive analysis as a method by explicitly articulating a concrete framework by which to identify micro-, meso-, and macro-levels of discourse. I also present a qualitative instrument for interviewing youth. Theoretically, this research offers an innovative and necessary expansion to the scope of organizational research by highlighting youth as current and future workers, pointing to the ways they are already engaged in work-life negotiation practices and considering how their micro-discursive practices serve to decenter the organization and make work and family meaningful.
ContributorsWay, Amy Kathleen (Author) / Trethewey, Angela (Thesis advisor) / Tracy, Sarah J. (Committee member) / Karin, Marcy (Committee member) / Arizona State University (Publisher)
Created2012
Description
The present study is a narrative representation of two individuals - one, a prison abolitionist living in the Phoenix area and, the other, myself as a writer and scholar - and their development of, negotiations with, desires for, and problematic performances of critical dispositions within the contemporary social order. In initiating this research, I framed my process as an exploration of the ways in which people who commit themselves to organized counter-hegemonic movements have developed critical dispositions despite their immersion in the normative discourse of American public schools and the relentless public pedagogies of neoliberal subjectivity and psyche. In essence, I wondered how people had gained both the capacity to perceive - however fleetingly - an outside to doxic structuration and, more difficult yet, to sacrifice the psychic comfort these structures promise for the risky work of creating a more just social order. Via psychoanalytic understandings of identity and desire, these stories explore and represent the primordial learning, experiences, and traumas that guided my informants to resist or reject dominant ontological narratives and normative cultural scripts in order to explore and maintain space - albeit exilic - for their own axiological and ethical development and, ultimately, to take up positions of active, educative resistance.
ContributorsBurdick, Jake (Author) / Barone, Thomas E (Thesis advisor) / Sandlin, Jennifer A. (Committee member) / Anijar-Appleton, Karen (Committee member) / Springgay, Stephanie (Committee member) / Arizona State University (Publisher)
Created2012
Description
The state of exception in Rwanda did not spontaneously occur in Rwanda, it was initially developed by German and Belgian colonizers, adopted by two successive Hutu regimes, and nurtured and fed for 35 years of Rwandan independence until its final realization in the 1994 genocide. Political theory regarding the development of the "space devoid of law" and necropolitics provide a framework with which to analyze the long pattern of state action that created a milieu in which genocide was an acceptable choice of action for a sovereign at risk of losing power. The study of little-known political theories such as Agamben's and Mbembe's is useful because it provides a lens through which we can analyze current state action throughout the world. As is true in many genocidal regimes, the Rwandan genocide did not just occur as a "descent into hell." Rather, state action over the course of decades in which the subjects of the state (People) were systematically converted into mere flesh beings (people), devoid of political or social value, creates the setting in which it is feasible to seek to eliminate those beings. A question to be posed to political actors and observers around the world today is at what point in the process of one nation's creation of the state of exception and adoption of necropolitics does the world have a right, and a duty, to intervene? Thus far, it has always occurred too late for the "people" in that sovereign to realize their political and social potential to be "People."
ContributorsSinema, Kyrsten (Author) / Johnson, John (Thesis advisor) / Quan, Helen (Committee member) / Gomez, Alan (Committee member) / Doty, Roxanne (Committee member) / Arizona State University (Publisher)
Created2012
Description
When ferrite materials are used in antenna designs, they introduce some interesting and unique performance characteristics. One of the attractive features, for example, is the ability to reconfigure the center frequency of the antenna. In addition, ferrite materials also introduce a number of challenges in the modeling and simulation of such antennas. In order for the ferrite material to be useful in an antenna design, it usually is subjected to an external magnetic field. This field induces the internal magnetic field inside the ferrite material. The internal field plays a pivotal role in the radiation characteristics of the antenna. Thus, from the numerical point of view, accurate computation of this field is critical to the overall accuracy of the analysis. Usually the internal field is non-uniform and its computation is often a rather complex and non-trivial task. Therefore, to facilitate the modeling, simplifying assumptions, which introduce some kind of averaging, are often made. In this study, ferrite-loaded cavity-backed slot antennas are used to demonstrate that averaging procedures can lead to very unsatisfactory results. For instance, it is common practice to assume that the external field is uniform by averaging its distribution. One of the pivotal points in this study is the demonstration that the external magnetic field plays a very significant role and should be included in the modeling without averaging, if the accurate results are to be attained. Results presented in this study clearly support this argument. A procedure which avoids such averaging is presented and verified by comparing simulations with measurements. In contrast to the previous formulations, the modeling methodology developed in this dissertation leads to accurate results which compare very well with measurements for both uniform and non-uniform field distributions. The utility of this methodology is especially evident for the case when the magnetic field is severely non-uniform.
ContributorsKononov, Victor G (Author) / Balanis, Constantine A. (Thesis advisor) / Pan, George (Committee member) / Rajan, Subramaniam D. (Committee member) / Aberle, James T. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Land management practices such as domestic animal grazing can alter plant communities via changes in soil structure and chemistry, species composition, and plant nutrient content. These changes can affect the abundance and quality of plants consumed by insect herbivores with consequent changes in population dynamics. These population changes can translate to massive crop damage and pest control costs. My dissertation focused on Oedaleus asiaticus, a dominant Asian locust, and had three main objectives. First, I identified morphological, physiological, and behavioral characteristics of the migratory ("brown") and non-migratory ("green") phenotypes. I found that brown morphs had longer wings, larger thoraxes and higher metabolic rates compared to green morphs, suggesting that developmental plasticity allows greater migratory capacity in the brown morph of this locust. Second, I tested the hypothesis of a causal link between livestock overgrazing and an increase in migratory swarms of O. asiaticus. Current paradigms generally assume that increased plant nitrogen (N) should enhance herbivore performance by relieving protein-limitation, increasing herbivorous insect populations. I showed, in contrast to this scenario, that host plant N-enrichment and high protein artificial diets decreased the size and viability of O. asiaticus. Plant N content was lowest and locust abundance highest in heavily livestock-grazed fields where soils were N-depleted, likely due to enhanced erosion and leaching. These results suggest that heavy livestock grazing promotes outbreaks of this locust by reducing plant protein content. Third, I tested for the influence of dietary imbalance, in conjunction with high population density, on migratory plasticity. While high population density has clearly been shown to induce the migratory morph in several locusts, the effect of diet has been unclear. I found that locusts reared at high population density and fed unfertilized plants (i.e. high quality plants for O. asiaticus) had the greatest migratory capacity, and maintained a high percent of brown locusts. These results did not support the hypothesis that poor-quality resources increased expression of migratory phenotypes. This highlights a need to develop new theoretical frameworks for predicting how environmental factors will regulate migratory plasticity in locusts and perhaps other insects.
ContributorsCease, Arianne (Author) / Harrison, Jon (Thesis advisor) / Elser, James (Thesis advisor) / DeNardo, Dale (Committee member) / Quinlan, Michael (Committee member) / Sabo, John (Committee member) / Arizona State University (Publisher)
Created2012
Description
Many Indigenous communities in North America develop tribal museums to preserve and control tribal knowledge and heritage and counteract negative effects of colonization. Tribal museums employ many Indigenous strategies related to Indigenous languages, knowledges, and material heritage. I argue that architecture can be an Indigenous strategy, too, by privileging Indigeneity through design processes, accommodating Indigenous activities, and representing Indigenous identities. Yet it is not clear how to design culturally appropriate Indigenous architectures meeting needs of contemporary Indigenous communities. Because few Indigenous people are architects, most tribal communities hire designers from outside of their communities. Fundamental differences challenge both Indigenous clients and their architects. How do Indigenous clients and their designers overcome these challenges? This dissertation is a history of the processes of creating a tribal museum, The Museum At Warm Springs, on the Confederated Tribes of the Warm Springs Reservation of Oregon. The focus is to understand what critical activities Tribal members, designers, and others did to create a museum whose architecture represents and serves its community. The study also considers how people did things so as to honor Indigenous traditions. Design and construction processes are considered along with strategies that Tribal members and their advocates used to get to where they were prepared to design and build a museum. Interviews with Tribal members, designers, and others were central sources for the research. Other sources include meeting minutes, correspondence, Tribal resolutions, and the Tribal newspaper. Visual sources such as drawings, photographs, and the museum itself were significant sources also. This study revealed several key activities that the Confederated Tribes did to position themselves to build the museum. They built an outstanding collection of Tribal artifacts, created and supported a museum society, and hired an outstanding executive director. The Tribes selected and secured a viable site and persisted in finding an architect who met their needs. Collaboration--within the interdisciplinary design team and between designers and Tribal members and contractors--was key. Tribal members shared cultural knowledge with designers who adapted to Indigenous modes of communication. Designers were sensitive to the landscape and committed to representing the Tribes and their world.
ContributorsMarshall, Anne L. (Anne Lawrason) (Author) / Crewe, Katherine (Thesis advisor) / Jojola, Theodore (Committee member) / Paxson, Lynn (Committee member) / Arizona State University (Publisher)
Created2012
Description
While exercising mammalian muscle increasingly relies on carbohydrates for fuel as aerobic exercise intensity rises above the moderate range, flying birds are extraordinary endurance athletes and fuel flight, a moderate-high intensity exercise, almost exclusively with lipid. In addition, Aves have long lifespans compared to weight-matched mammals. As skeletal muscle mitochondria account for the majority of oxygen consumption during aerobic exercise, the primary goal was to investigate differences in isolated muscle mitochondria between these species and to examine to what extent factors intrinsic to mitochondria may account for the behavior observed in the intact tissue and whole organism. First, maximal enzyme activities were assessed in sparrow and rat mitochondria. Citrate synthase and aspartate aminotransferase activity were higher in sparrow compared to rat mitochondria, while glutamate dehydrogenase activity was lower. Sparrow mitochondrial NAD-linked isocitrate dehydrogenase activity was dependent on phosphate, unlike the mammalian enzyme. Next, the rate of oxygen consumption (JO), electron transport chain (ETC) activity, and reactive oxygen species (ROS) production were assessed in intact mitochondria. Maximal rates of fat oxidation were lower than for carbohydrate in rat but not sparrow mitochondria. ETC activity was higher in sparrows, but no differences were found in ROS production between species. Finally, fuel selection and control of respiration at three rates between rest and maximum were assessed. Mitochondrial fuel oxidation and selection mirrored that of the whole body; in rat mitochondria the reliance on carbohydrate increased as the rate of oxygen consumption increased, whereas fat dominated under all conditions in the sparrow. These data indicate fuel selection, at least in part, can be modulated at the level of the mitochondrial matrix when multiple substrates are present at saturating levels. As an increase in matrix oxidation-reduction potential has been linked to a suppression of fat oxidation and high ROS production, the high ETC activity relative to dehydrogenase activity in avian compared to mammalian mitochondria may result in lower matrix oxidation-reduction potential, allowing fatty acid oxidation to proceed while also resulting in low ROS production in vivo.
ContributorsKuzmiak, Sarah (Author) / Willis, Wayne T (Thesis advisor) / Mandarino, Lawrence (Committee member) / Sweazea, Karen (Committee member) / Harrison, Jon (Committee member) / Gadau, Juergen (Committee member) / Arizona State University (Publisher)
Created2012
Description
Future robotic and human missions to the Moon and Mars will need in situ capabilities to characterize the mineralogy of rocks and soils within a microtextural context. Such spatially-correlated information is considered crucial for correct petrogenetic interpretations and will be key observations for assessing the potential for past habitability on Mars. These data will also enable the selection of the highest value samples for further analysis and potential caching for return to Earth. The Multispectral Microscopic Imager (MMI), similar to a geologist's hand lens, advances the capabilities of current microimagers by providing multispectral, microscale reflectance images of geological samples, where each image pixel is comprised of a 21-band spectrum ranging from 463 to 1735 nm. To better understand the capabilities of the MMI in future surface missions to the Moon and Mars, geological samples comprising a range of Mars-relevant analog environments as well as 18 lunar rocks and four soils, from the Apollo collection were analyzed with the MMI. Results indicate that the MMI images resolve the fine-scale microtextural features of samples, and provide important information to help constrain mineral composition. Spectral end-member mapping revealed the distribution of Fe-bearing minerals (silicates and oxides), along with the presence of hydrated minerals. In the case of the lunar samples, the MMI observations also revealed the presence of opaques, glasses, and in some cases, the effects of space weathering in samples. MMI-based petrogenetic interpretations compare favorably with laboratory observations (including VNIR spectroscopy, XRD, and thin section petrography) and previously published analyses in the literature (for the lunar samples). The MMI was also deployed as part of the 2010 ILSO-ISRU field test on the slopes of Mauna Kea, Hawaii and inside the GeoLab as part of the 2011 Desert RATS field test at the Black Point Lava Flow in northern Arizona to better assess the performance of the MMI under realistic field conditions (including daylight illumination) and mission constraints to support human exploration. The MMI successfully imaged rocks and soils in outcrops and samples under field conditions and mission operation scenarios, revealing the value of the MMI to support future rover and astronaut exploration of planetary surfaces.
ContributorsNúñez Sánchez, Jorge Iván (Author) / Farmer, Jack D. (Thesis advisor) / Christensen, Philip R. (Committee member) / Garcia-Pichel, Ferran (Committee member) / Robinson, Mark S. (Committee member) / Sellar, R. Glenn (Committee member) / Williams, Lynda B. (Committee member) / Arizona State University (Publisher)
Created2012