Matching Items (43,913)
Description
Combretastatin A-4 (CA-4) represents one of the most promising antineoplastic and cancer vascular targeting stilbenes that have been isolated from the South African bush willow, Combretum Caffrum Kuntze. In order to further explore the bioactivity of this molecule, a diiodo derivative of CA-4, as well as its phosphate prodrug, was synthesized and analyzed for its biological activity; although only a scale up synthesis of this compound was performed herein for ongoing analysis. In general, no increased specificity was noted for the human cancer cell lines. Antiangiogenic properties were similar to the untreated control. The diiodocombstatin was active against M. luteus, and its phosphate prodrugs were very active against N. gonorrhoeae. Combretastain A-2 is another biologically active stilbene isolated from Combretum Caffrum Kuntze. In an attempt to increase biological activity of this molecule both mono-iodo and diiodo derivatives have been partially synthesized. The initial step involving the iodination of piperonal utilizes a novel, cost effective and mild reaction. The iodo stilbenes were obtained via a Wittig reaction using phosphonium salts 25 and 27 along with 2,3-Bis-[tert-butyldimethylsiloxy]-4-methoxy benzaldehyde 29. Deprotection of the subsequent z-stilbenes, non-isolated mono-iodo stilbene and the diiodo 30 produced two synthetic objective z-stilbenes 16 and 17. Synthesis as well as biological analysis is ongoing.
ContributorsTrickey-Platt, Brindi Brooks (Author) / Pettit, George R. (Thesis advisor) / Moore, Ana (Committee member) / Skibo, Edward (Committee member) / Arizona State University (Publisher)
Created2011
Description
Driven by concern over environmental, economic and social problems, small, place based communities are engaging in processes of transition to become more sustainable. These communities may be viewed as innovative front runners of a transition to a more sustainable society in general, each one, an experiment in social transformation. These experiments present learning opportunities to build robust theories of community transition and to create specific, actionable knowledge to improve, replicate, and accelerate transitions in real communities. Yet to date, there is very little empirical research into the community transition phenomenon. This thesis empirically develops an analytical framework and method for the purpose of researching community transition processes, the ultimate goal of which is to arrive at a practice of evidence based transitions. A multiple case study approach was used to investigate three community transitions while simultaneously developing the framework and method in an iterative fashion. The case studies selected were Ashton Hayes, a small English village, BedZED, an urban housing complex in London, and Forres, a small Scottish town. Each community was visited and data collected by interview and document analysis. The research design brings together elements of process tracing, transformative planning and governance, sustainability assessment, transition path analysis and transition management within a multiple case study envelope. While some preliminary insights are gained into community transitions based on the three cases the main contribution of this thesis is in the creation of the research framework and method. The general framework and method developed has potential for standardizing and synthesizing research of community transition processes leading to both theoretical and practical knowledge that allows sustainability transition to be approached with confidence and not just hope.
ContributorsForrest, Nigel (Author) / Wiek, Arnim (Thesis advisor) / Golub, Aaron (Thesis advisor) / Redman, Charles (Committee member) / White, Dave (Committee member) / Arizona State University (Publisher)
Created2011
Description
Navigating within non-linear structures is a challenge for all users when the space is large but the problem is most pronounced when the users are blind or visually impaired. Such users access digital content through screen readers like JAWS which read out the text on the screen. However presentation of non-linear narratives in such a manner without visual cues and information about spatial dependencies is very inefficient for such users. The NSDL Science Literacy StrandMaps are visual layouts to help students and teachers browse educational resources. A Strandmap shows relationships between concepts and how they build upon one another across grade levels. NSDL Strandmaps are non-linear narratives which need to be presented to users who are blind in an effective way. A good summary of the Strandmap can give the users an idea about the concepts that are explained in it. This can help them decide whether to view the map or not. In addition, a preview-based navigation mechanism can help users decide which direction they want to take, based on a preview of upcoming content in each direction. Given a non-linear narrative like a Strandmap which has both text and structure, and a word limit w, the goal of this thesis is to find the best way to create its summary. The following approaches are considered: – Purely Text-based Approach using a Multi-document Text Summarizer – Purely Structure-based Approach using PageRank – Approaches Combining both Text and Structure → CUTS-Based Approach (Topic Segmentation) → PageRank with Content Since no reference summaries for such structures were available, user studies were conducted to evaluate these algorithms. PageRank with Content approach performed the best. Another important conclusion was that text and structure are intertwined in a Strandmap by design.
ContributorsGaur, Shruti (Author) / Candan, Kasim Selcuk (Thesis advisor) / Sundaram, Hari (Committee member) / Davulcu, Hasan (Committee member) / Arizona State University (Publisher)
Created2011
Description
In order to catch the smartest criminals in the world, digital forensics examiners need a means of collaborating and sharing information with each other and outside experts that is not prohibitively difficult. However, standard operating procedures and the rules of evidence generally disallow the use of the collaboration software and techniques that are currently available because they do not fully adhere to the dictated procedures for the handling, analysis, and disclosure of items relating to cases. The aim of this work is to conceive and design a framework that provides a completely new architecture that 1) can perform fundamental functions that are common and necessary to forensic analyses, and 2) is structured such that it is possible to include collaboration-facilitating components without changing the way users interact with the system sans collaboration. This framework is called the Collaborative Forensic Framework (CUFF). CUFF is constructed from four main components: Cuff Link, Storage, Web Interface, and Analysis Block. With the Cuff Link acting as a mediator between components, CUFF is flexible in both the method of deployment and the technologies used in implementation. The details of a realization of CUFF are given, which uses a combination of Java, the Google Web Toolkit, Django with Apache for a RESTful web service, and an Ubuntu Enterprise Cloud using Eucalyptus. The functionality of CUFF's components is demonstrated by the integration of an acquisition script designed for Android OS-based mobile devices that use the YAFFS2 file system. While this work has obvious application to examination labs which work under the mandate of judicial or investigative bodies, security officers at any organization would benefit from the improved ability to cooperate in electronic discovery efforts and internal investigations.
ContributorsMabey, Michael Kent (Author) / Ahn, Gail-Joon (Thesis advisor) / Yau, Stephen S. (Committee member) / Huang, Dijiang (Committee member) / Arizona State University (Publisher)
Created2011
Description
The sacred San Francisco Peaks in northern Arizona have been at the center of a series of land development controversies since the 1800s. Most recently, a controversy arose over a proposal by the ski area on the Peaks to use 100% reclaimed water to make artificial snow. The current state of the San Francisco Peaks controversy would benefit from a decision-making process that holds sustainability policy at its core. The first step towards a new sustainability-focused deliberative process regarding a complex issue like the San Francisco Peaks controversy requires understanding the issue's origins and the perspectives of the people involved in the issue. My thesis provides an historical analysis of the controversy and examines some of the laws and participatory mechanisms that have shaped the decision-making procedures and power structures from the 19th century to the early 21st century.
ContributorsMahoney, Maren (Author) / Hirt, Paul W. (Thesis advisor) / Tsosie, Rebecca (Committee member) / White, Dave (Committee member) / Arizona State University (Publisher)
Created2011
Description
Learning and transfer were investigated for a categorical structure in which relevant stimulus information could be mapped without loss from one modality to another. The category space was composed of three non-overlapping, linearly-separable categories. Each stimulus was composed of a sequence of on-off events that varied in duration and number of sub-events (complexity). Categories were learned visually, haptically, or auditorily, and transferred to the same or an alternate modality. The transfer set contained old, new, and prototype stimuli, and subjects made both classification and recognition judgments. The results showed an early learning advantage in the visual modality, with transfer performance varying among the conditions in both classification and recognition. In general, classification accuracy was highest for the category prototype, with false recognition of the category prototype higher in the cross-modality conditions. The results are discussed in terms of current theories in modality transfer, and shed preliminary light on categorical transfer of temporal stimuli.
ContributorsFerguson, Ryan (Author) / Homa, Donald (Thesis advisor) / Goldinger, Stephen (Committee member) / Glenberg, Arthur (Committee member) / Arizona State University (Publisher)
Created2011
Description
In the U.S., high-speed passenger rail has recently become an active political topic, with multiple corridors currently being considered through federal and state level initiatives. One frequently cited benefit of high-speed rail proposals is that they offer a transition to a more sustainable transportation system with reduced greenhouse gas emissions and fossil energy consumption. This study investigates the feasibility of high-speed rail development as a long-term greenhouse gas emission mitigation strategy while considering major uncertainties in the technological and operational characteristics of intercity travel. First, I develop a general model for evaluating the emissions impact of intercity travel modes. This model incorporates aspects of life-cycle assessment and technological forecasting. The model is then used to compare future scenarios of energy and greenhouse gas emissions associated with the development of high-speed rail and other intercity travel technologies. Three specific rail corridors are evaluated and policy guidelines are developed regarding the emissions impacts of these investments. The results suggest prioritizing high-speed rail investments on short, dense corridors with fewer stops. Likewise, less emphasis should be placed on larger investments that require long construction times due to risks associated with payback of embedded emissions as competing technology improves.
ContributorsBurgess, Edward (Author) / Williams, Eric (Thesis advisor) / Fink, Jonathan (Thesis advisor) / Yaro, Robert (Committee member) / Arizona State University (Publisher)
Created2011
Description
This qualitative case study examines the rationales of the relationship between Arizona State University (ASU)--an American public research university--and Tecnologico de Monterrey (ITESM), a Mexican private not for profit research university. The focus of the study is to document the different meanings participants attached to the rationales of this international inter-university relationship. The conceptual framework draws from internationalization of higher education and interpretive policy analysis literature. Qualitative methodologies were utilized in both data collection and analysis. Data consisted of institutional policy documents, a ranking survey, and semi-structured interviews with faculty, administrators, and senior leadership from both universities. This study demonstrates that the rationales of the ASU-ITESM relationship are complex and dynamic. They have a function (e.g., declared, interpreted, enacted) and meanings attached (e.g., type, scope, and priority). Declared rationales were expressed in an ideal state in institutional policy. Those were interpreted by the participants according to their individual sense-making framework, thus becoming the interpreted rationales. Participants acted upon such understandings; these enacted rationales refer to the real rationales shaping the inter-university relationship. Findings also show there were three different categories of meanings participants attached to rationales, based on their type, scope and priority. In terms of type, rationales took the form of values, interests and needs, or expected benefits; they can also be academic, economic, political, or social/cultural. In scope, rationales are broad or specific addressing the relationship overall or specific initiatives within; they target individual, organizational, or societal levels. As for priority, participants interpreted and acted upon rationales with high, moderate or low importance influenced by their job position (e.g., faculty, administrators, senior leadership).
ContributorsCamacho Lizárraga, Mónica Irene (Author) / Ovando, Carlos J. (Thesis advisor) / Allison, Maria T. (Committee member) / Turner, Caroline S. (Committee member) / Arizona State University (Publisher)
Created2011
Description
As a prelude to a study on the post-liquefaction properties and structure of soil, an investigation of ground freezing as an undisturbed sampling technique was conducted to investigate the ability of this sampling technique to preserve soil structure and properties. Freezing the ground is widely regarded as an appropriate technique to recover undisturbed samples of saturated cohesionless soil for laboratory testing, despite the fact that water increases in volume when frozen. The explanation generally given for the preservation of soil structure using the freezing technique was that, as long as the freezing front advanced uni-directionally, the expanding pore water is expelled ahead of the freezing front as the front advances. However, a literature review on the transition of water to ice shows that the volume of ice expands approximately nine percent after freezing, bringing into question the hypothesized mechanism and the ability of a frozen and then thawed specimen to retain the properties and structure of the soil in situ. Bench-top models were created by pluviation of sand. The soil in the model was then saturated and subsequently frozen. Freezing was accomplished using a pan filled with alcohol and dry ice placed on the surface of the sand layer to induce a unidirectional freezing front in the sample container. Coring was used to recover frozen samples from model containers. Recovered cores were then placed in a triaxial cell, thawed, and subjected to consolidated undrained loading. The stress-strain-strength behavior of the thawed cores was compared to the behavior of specimens created in a split mold by pluviation and then saturated and sheared without freezing and thawing. The laboratory testing provide insight to the impact of freezing and thawing on the properties of cohesionless soil.
ContributorsKatapa, Kanyembo (Author) / Kavazanjian, Edward (Thesis advisor) / Houston, Sandra (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2011
Description
ABSTRACT With projections indicating that by the year 2025, one of every four K-12 students in the United States will be Latino, addressing the needs of Latino students is an important question for educators. This study approached this question through an analysis of the educational life histories, stories, of successful first generation Mexican-American college graduates to understand some of the factors which helped them succeed in college. I categorized the stories inductively into three themes: 1) stories of students and school, 2) stories of friends, family, and cultural communities, and 3) stories about race and politics. Participants' intellectual self-concept, both positive and negative, was to a great extent influenced by the messages they received from the educational system. Some of the participants took a traditional path from high school through college, while others took very indirect paths. The support that they received from special programs at the university as well as from their webs of support was crucial in their success. In addition, I found that race mattered when the participants transitioned from their majority Latino high schools to the majority white university as the participants told stories of navigating the cultural and racial dynamics of their status as college students. The participants in my study worked hard to achieve their college degrees. "It's hard" was a phrase often repeated by all participants; hard work was also a cultural value passed on by hard working parents and family members. Stories of luck, both good and bad, factored into their educational life histories. Collaborative programs between secondary school and the university were helpful in creating a transitional bridge for the participants as were culturally-based mentoring programs. The participants benefitted from the culturally-based support they received at the university and the cultural and emotional support of their families. The participants' stories highlight the importance of a race-conscious approach to college going; one which begins with race and builds cross-racial coalitions. This approach would benefit Latino students and, ultimately improve the college going experiences of all students.
ContributorsSheffield, Martha Lynn (Author) / Powers, Jeanne M. (Thesis advisor) / Appleton, Nicholas (Committee member) / Fischman, Gustavo (Committee member) / Arizona State University (Publisher)
Created2011