Matching Items (43,917)
Description
The spectacular geological panoramas of Grand Canyon National Park (GCNP) motivate the curiosity of visitors about geology. However, there is little research on how well these visitors understand the basic geologic principles on display in the Canyon walls. The new Trail of Time (ToT) interpretative exhibit along the South Rim uses Grand Canyon vistas to teach these principles. Now being visited by thousands daily, the ToT is a uniquely valuable setting for research on informal learning of geologic time and other basic geologic concepts. At the ToT, visitors are not only asked to comprehend a linear timeline, but to associate it with the strata exposed in the walls of the Canyon. The research addressed two primary questions: (1) how do visitors of the National Park use elements of the geologic landscape of the Grand Canyon to explain fundamental principles of relative geologic time? and (2) how do visitors reconcile the relationship between the horizontal ToT timeline and the vertical encoding of time in the strata exposed in the Canyon walls? Semi-structured interviews tracked participants' understanding of the ToT exhibit and of basic principles of geologic time. Administering the verbal analysis method of Chi (1997) to the interview transcripts, the researcher identified emergent themes related to how the respondents utilized the landscape to answer interview questions. Results indicate that a majority of respondents are able to understand principles of relative geologic time by utilizing both the observed and inferred landscape of Grand Canyon. Results also show that by applying the same integrated approach to the landscape, a majority of respondents are able to reconcile stratigraphic time with the horizontal ToT timeline. To gain deeper insight into the cognitive skills activated to correctly understand geologic principles the researcher used Dodick and Orion's application of Montangero's (1996) diachronic thinking model to code responses into three schemes: (1) transformation, (2) temporal organization, and (3) interstage linkage. Results show that correct responses required activation of the temporal organization scheme or the more advanced interstage linkage scheme. Appropriate application of these results can help inform the development of future outdoor interpretive geoscience exhibits.
Contributors
Frus, Rebecca (Author) / Semken, Steven (Thesis advisor) / Baker, Dale (Committee member) / Farmer, Jack (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Self-awareness and liberation often start with an analysis of the relationship between individual and society, a relationship based on the delicate balance of personal desire and responsibility to others. While societal structures, such as family, tradition, religion, and community, may be repressive to individuals, they also provide direction, identity and meaning to an individual's life. In Kate Chopin's The Awakening and André Gide's L'Immoraliste the protagonists are faced with such a dilemma. Often informed by gender roles and socio-economic class, the container or filter that society offers to shape and mediate human experience is portrayed in both novels as a fictitious self donned for society's benefit --can seem repressive or inadequate. Yet far from being one-dimensional stories of individuals who eschew the bonds of a restrictive society, both novels show that liberation can lead to entrapment. Once society's limits are transgressed, the characters face the infinitude and insatiety of their liberated desires and the danger of self-absorption. Chopin and Gide explore these issues of desire, body, and social authority in order to portray Edna's and Michel's search for an authentic self. The characters' search for authenticity allows for the loosening of restriction and embrace of desire and the body, phenomena that appear to liberate them from the dominant bourgeois society. Yet, for both Edna and Michel, an embrace of the body and individual desire threatens to unsettle the balance between individual and society. As Edna and Michel break away from society's prescribed path, both struggle to find themselves. Edna and Michel become aware of themselves in a variety of different ways: speaking and interacting with others, observing the social mores of those around them and engaging in creative activity, such as, for Edna, painting and planning a dinner party, or for Michel, teaching and writing. Chopin's 1899 novel The Awakening and André Gide's 1902 novel L'Immoraliste explore the consequences of individual liberation from the constricting bonds of religion, society, and the family. In depicting these conflicts, the authors examine the relationship between individual and society, freedom and restraint, and what an individual's relationship to his or her community should be.
Contributors
McCulla, Jessica (Author) / Canovas, Frédéric (Committee member) / Cruse, Markus (Committee member) / Losse, Deborah (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The advent of advanced reproductive technologies has sparked a number of ethical concerns regarding the practices of reproductive tourism and commercial gestational surrogacy. In the past few decades, reproductive tourism has become a global industry in which individuals or couples travel, usually across borders, to gain access to reproductive services. This marketable field has expanded commercial gestational surrogacy--defined by a contractual relationship between an intending couple and gestational surrogate in which the surrogate has no genetic tie to fetus--to take on transnational complexities. India has experienced extreme growth due to a preferable combination of western educated doctors and extremely low medical costs. However, a slew of ethical issues have been brought to the forefront: the big ones manifesting as concern for reduction of a woman's worth to her reproductive capabilities along with concern for exploitation of third world women. This project will be based exclusively on literature review and serves primarily as a call for cultural competency and understanding the circumstances that gestational surrogates are faced with before implementing policy regulating commercial gestational surrogacy. The paper argues that issues of exploitation and commodification hinge on constructions of motherhood. It is critical to define and understand definitions of motherhood and how these definitions affect a woman's approach to reproduction within the cultural context of a gestational surrogate. This paper follows the case study of the Akanksha Infertility Clinic in northern India, a surrogacy clinic housing around 50 Indian surrogates. The findings of the project invokes the critical significance of narrative ethics, which help Indian surrogates construct the practice of surrogacy so that it fits into cultural comprehensions of Indian motherhood--in which motherhood is selfless, significant, and shared.
Contributors
Moorthy, Anjali (Author) / Robert, Jason S (Thesis advisor) / Hurlbut, Benjamin (Committee member) / Ellison, Karin (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Conformational changes in biomolecules often take place on longer timescales than are easily accessible with unbiased molecular dynamics simulations, necessitating the use of enhanced sampling techniques, such as adaptive umbrella sampling. In this technique, the conformational free energy is calculated in terms of a designated set of reaction coordinates. At the same time, estimates of this free energy are subtracted from the potential energy in order to remove free energy barriers and cause conformational changes to take place more rapidly. This dissertation presents applications of adaptive umbrella sampling to a variety of biomolecular systems. The first study investigated the effects of glycosylation in GalNAc2-MM1, an analog of glycosylated macrophage activating factor. It was found that glycosylation destabilizes the protein by increasing the solvent exposure of hydrophobic residues. The second study examined the role of bound calcium ions in promoting the isomerization of a cis peptide bond in the collagen-binding domain of Clostridium histolyticum collagenase. This study determined that the bound calcium ions reduced the barrier to the isomerization of this peptide bond as well as stabilizing the cis conformation thermodynamically, and identified some of the reasons for this. The third study represents the application of GAMUS (Gaussian mixture adaptive umbrella sampling) to on the conformational dynamics of the fluorescent dye Cy3 attached to the 5' end of DNA, and made predictions concerning the affinity of Cy3 for different base pairs, which were subsequently verified experimentally. Finally, the adaptive umbrella sampling method is extended to make use of the roll angle between adjacent base pairs as a reaction coordinate in order to examine the bending both of free DNA and of DNA bound to the archaeal protein Sac7d. It is found that when DNA bends significantly, cations from the surrounding solution congregate on the concave side, which increases the flexibility of the DNA by screening the repulsion between phosphate backbones. The flexibility of DNA on short length scales is compared to the worm-like chain model, and the contribution of cooperativity in DNA bending to protein-DNA binding is assessed.
Contributors
Spiriti, Justin Matthew (Author) / van der Vaart, Arjan (Thesis advisor) / Chizmeshya, Andrew (Thesis advisor) / Matyushov, Dmitry (Committee member) / Fromme, Petra (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Via my personal, academic and professional journey, I closely examine my career growth and how my perspectives on early childhood environments developed in reference to free play. Using a narrative format, I share personal experiences that have shaped my views on free play. Free play is a type of play that features choices, freedom of selection, cognitive and social development, and child interest. I review relevant literature and weave in my personal and professional experiences in order to reflect on free play from two different perspectives: participant (child), and the Early Childhood Professional (teacher and/or administrator). I also demonstrate how my professional and academic milestones have contributed to my developing beliefs and ideas put into practice about free play in early childhood environments.
Contributors
Alleyne, Teja Diamond (Author) / Swadener, Beth Elizabeth (Thesis advisor) / Nagasawa, Mark (Committee member) / Bartlett, Margaret (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The Adult Basic Education/Literacy (ABEL) system in America can suffer critique. In a system that is staffed mostly by volunteers and plagued by funding woes, the experience of adult learners as participants within the institutional structure can be easily overlooked. Adult students are described as transient and difficult to track. Even so, and maybe because of this characterization, leaders within the local ABEL discourse make it their mission to reach these students in order to assist them to a better quality of life. However, there is more than one discourse circulating within the system. A discourse of outreach and intervention is one strand. The complex relationships education centers engage with more powerful government institutions causes another, more strident political discourse that constrains and influences the discourse within ABEL education centers, down to the classroom level. Within the vortex of motivations and needs created by institutional discourse, an institutional critique may give voice to those who experience the discourse in a way that hinders their education. This paper pursues critique, not through direct reconstruction, but through the encouragement of alternative discourses as additional institutions enter the system. AmeriCorps is presented as an institution that allows for more democratic participation through its distinct organizational features. The features that emerge in AmeriCorps projects offer hope for alternative models of participation within the highly politicized ABEL discourse.
Contributors
Foy, Christine (Author) / Long, Elenore (Thesis advisor) / Daer, Alice (Thesis advisor) / Boyd, Patricia (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Studies have demonstrated that anthocyanins can function as antioxidants, reduce inflammation, and improve dyslipidemia. Tart cherries are anthocyanin-rich, making them particularly attractive as a functional food to improve cardiovascular disease (CVD) risk. There have been few published studies to date examining the impact of tart cherries on biomarkers of dyslipidemia and inflammation, particularly in overweight and obese individuals at high risk for these conditions. This study evaluated the effect of consuming 100% tart cherry juice daily on blood lipids including total cholesterol, low-density lipoprotein cholesterol (LDL-C), calculated very low density lipoprotein cholesterol (VLDL-C), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and the CVD risk ratios, as well as the inflammatory biomarkers interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP), monocyte chemotactic protein-1 (MCP-1), and erythrocyte sedimentation rate (ESR) following a 4-week period. Based on the high anthocyanin content of tart cherries, it was hypothesized that the lipid and inflammatory profiles would be significantly improved following the intervention. A total of 26 men and women completed this 4-week randomized, single-blind, placebo-controlled, crossover study. Participants were randomized to drink either 8 ounces of placebo beverage or tart cherry juice daily for 4 weeks. Following a 4-week washout period, the alternate beverage was consumed. Ultimately, this investigation demonstrated no statistically significant alterations in any of the lipid or inflammatory biomarkers when analyzed across time and between interventions (p > 0.05). As expected, glucose and insulin parameters remained stable over the duration of the study, as well as self-reported physical activity level, total calorie consumption, and macronutrient intake. However, trans-fat was reported to be significantly higher during the cherry arm of the study as compared to the placebo arm (p < 0.05), potentially confounding other results. Although the results of this study were equivocal, it is feasible that a higher dose, longer treatment duration, or more susceptible target population may be required to elicit significant effects. Consequently, further investigation is necessary to clarify this research.
Contributors
Coles, Katie (Author) / Martin, Keith R. (Thesis advisor) / Traustadottir, Tinna (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created
2012
Description
This thesis focuses on the continued extension, validation, and application of combined thermal-structural reduced order models for nonlinear geometric problems. The first part of the thesis focuses on the determination of the temperature distribution and structural response induced by an oscillating flux on the top surface of a flat panel. This flux is introduced here as a simplified representation of the thermal effects of an oscillating shock on a panel of a supersonic/hypersonic vehicle. Accordingly, a random acoustic excitation is also considered to act on the panel and the level of the thermo-acoustic excitation is assumed to be large enough to induce a nonlinear geometric response of the panel. Both temperature distribution and structural response are determined using recently proposed reduced order models and a complete one way, thermal-structural, coupling is enforced. A steady-state analysis of the thermal problem is first carried out that is then utilized in the structural reduced order model governing equations with and without the acoustic excitation. A detailed validation of the reduced order models is carried out by comparison with a few full finite element (Nastran) computations. The computational expedience of the reduced order models allows a detailed parametric study of the response as a function of the frequency of the oscillating flux. The nature of the corresponding structural ROM equations is seen to be of a Mathieu-type with Duffing nonlinearity (originating from the nonlinear geometric effects) with external harmonic excitation (associated with the thermal moments terms on the panel). A dominant resonance is observed and explained. The second part of the thesis is focused on extending the formulation of the combined thermal-structural reduced order modeling method to include temperature dependent structural properties, more specifically of the elasticity tensor and the coefficient of thermal expansion. These properties were assumed to vary linearly with local temperature and it was found that the linear stiffness coefficients and the "thermal moment" terms then are cubic functions of the temperature generalized coordinates while the quadratic and cubic stiffness coefficients were only linear functions of these coordinates. A first validation of this reduced order modeling strategy was successfully carried out.
Contributors
Matney, Andrew (Author) / Mignolet, Marc (Thesis advisor) / Jiang, Hanqing (Committee member) / Spottswood, Stephen (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Natural photosynthesis features a complex biophysical/chemical process that requires sunlight to produce energy rich products. It is one of the most important processes responsible for the appearance and sustainability of life on earth. The first part of the thesis focuses on understanding the mechanisms involved in regulation of light harvesting, which is necessary to balance the absorption and utilization of light energy and in that way reduce the effect caused by photooxidative damage. In photosynthesis, carotenoids are responsible not only for collection of light, but also play a major role in protecting the photosynthetic system. To investigate the role of carotenoids in the quenching of the excited state of cyclic tetrapyrroles, two sets of dyads were studied. Both sets of dyads contain zinc phthalocyanine (Pc) covalently attached to carotenoids of varying conjugation lengths. In the first set of dyads, carotenoids were attached to the phthalocyanine via amide linkage. This set of dyads serves as a good model for understanding the molecular "gear-shift" mechanism, where the addition of one double bond can turn the carotenoid from a nonquencher to a very strong quencher of the excited state of a tetrapyrrole. In the second set of dyads, carotenoids were attached to phthalocyanine via a phenyl amino group. Two independent studies were performed on these dyads: femtosecond transient absorption and steady state fluorescence induced by two-photon excitation. In the transient absorption study it was observed that there is an instantaneous population of the carotenoid S1 state after Pc excitation, while two-photon excitation of the optically forbidden carotenoid S1 state shows 1Pc population. Both observations provide a strong indication of the existence of a shared excitonic state between carotenoid and Pc. Similar results were observed in LHC II complexes in plants, supporting the role of such interactions in photosynthetic down regulation. In the second chapter we describe the synthesis of porphyrin dyes functionalized with carboxylate and phosphonate anchoring groups to be used in the construction of photoelectrochemical cells containing a porphyrin-IrO2·nH2O complex immobilized on a TiO2 electrode. The research presented here is a step in the development of high potential porphyrin-metal oxide complexes to be used in the photooxidation of water. The last chapter focuses on developing synthetic strategies for the construction of an artificial antenna system consisting of porphyrin-silver nanoparticle conjugates, linked by DNA of varied length to study the distance dependence of the interaction between nanoparticles and the porphyrin chromophore. Preliminary studies indicate that at the distance of about 7-10 nm between porphyrin and silver nanoparticle is where the porphyrin absorption leading to fluorescence shows maximum enhancement. These new hybrid constructs will be helpful for designing efficient light harvesting systems.
Contributors
Pillai, Smitha (Author) / Moore, Ana (Thesis advisor) / Moore, Thomas (Committee member) / Gould, Ian (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Sinaloa, a coastal state in the northwest of Mexico, is known for irrigated conventional agriculture, and is considered one of the greatest successes of the Green Revolution. With the neoliberal reforms of the 1990s, Sinaloa farmers shifted out of conventional wheat, soy, cotton, and other commodities and into white maize, a major food staple in Mexico that is traditionally produced by millions of small-scale farmers. Sinaloa is now a major contributor to the national food supply, producing 26% of total domestic white maize production. Research on Sinaloa's maize has focused on economic and agronomic components. Little attention, however, has been given to the environmental sustainability of Sinaloa's expansion in maize. With uniquely biodiverse coastal and terrestrial ecosystems that support economic activities such as fishing and tourism, the environmental consequences of agriculture in Sinaloa are important to monitor. Agricultural sustainability assessments have largely focused on alternative agricultural approaches, or espouse alternative philosophies that are biased against conventional production. Conventional agriculture, however, provides a significant portion of the world's calories. In addition, incentives such as federal subsidies and other institutions complicate transitions to alternative modes of production. To meet the agricultural sustainability goals of food production and environmental stewardship, we must put conventional agriculture on a more sustainable path. One step toward achieving this is structuring agricultural sustainability assessments around achievable goals that encourage continual adaptations toward sustainability. I attempted this in my thesis by assessing conventional maize production in Sinaloa at the regional/state scale using network analysis and incorporating stakeholder values through a multicriteria decision analysis approach. The analysis showed that the overall sustainability of Sinaloa maize production is far from an ideal state. I made recommendations on how to improve the sustainability of maize production, and how to better monitor the sustainability of agriculture in Sinaloa.
Contributors
Bausch, Julia Christine (Author) / Eakin, Hallie (Thesis advisor) / Bojórquez-Tapia, Luis (Committee member) / Childers, Daniel L. (Committee member) / Arizona State University (Publisher)
Created
2011