Matching Items (43,917)
Description
In this study, I examined how African American students in a church youth group constructed ethnic and spiritual identities as they engaged with community literacy practices. Arizona's small, scattered population of African Americans is reflected within participants' multi-ethnic schools where they describe feelings of being almost invisible to school agents and peers. Listening to students, I came to deeply understand how they struggled with cultural isolation and racial discrimination. The growing tensions with state immigration reform only magnified those feelings as participants perceived the ban on ethnic studies to be another attempt to exclude them from school curriculums. By using utilizing four identity types, I gained greater insights into participants' negotiation of ethnicity and spirituality. Drawing from critical race theory, I utilized counter-storytelling to not only recapture participants' experiences with social injustice, but also to illustrate how the youth group empowers the students to become activists. Resisting the paralyzing effects of racial stereotypes, participants emerged as essayists, artists, orators, and spoken word poets.
Contributors
Nicholson, Cynthia Salley (Author) / Paris, Django (Thesis advisor) / Nilsen, Alleen (Committee member) / Stanfield, John H. (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Infectious diseases are a leading cause of death worldwide. With the development of drugs, vaccines and antibiotics, it was believed that for the first time in human history diseases would no longer be a major cause of mortality. Newly emerging diseases, re-emerging diseases and the emergence of microorganisms resistant to existing treatment have forced us to re-evaluate our optimistic perspective. In this study, a simple mathematical framework for super-infection is considered in order to explore the transmission dynamics of drug-resistance. Through its theoretical analysis, we identify the conditions necessary for the coexistence between sensitive strains and drug-resistant strains. Farther, in order to investigate the effectiveness of control measures, the model is extended so as to include vaccination and treatment. The impact that these preventive and control measures may have on its disease dynamics is evaluated. Theoretical results being confirmed via numerical simulations. Our theoretical results on two-strain drug-resistance models are applied in the context of Malaria, antimalarial drugs, and the administration of a possible partially effective vaccine. The objective is to develop a monitoring epidemiological framework that help evaluate the impact of antimalarial drugs and partially-effective vaccine in reducing the disease burden at the population level. Optimal control theory is applied in the context of this framework in order to assess the impact of time dependent cost-effective treatment efforts. It is shown that cost-effective combinations of treatment efforts depend on the population size, cost of implementing treatment controls, and the parameters of the model. We use these results to identify optimal control strategies for several scenarios.
Contributors
Urdapilleta, Alicia (Author) / Castillo-Chavez, Carlos (Thesis advisor) / Wang, Xiaohong (Thesis advisor) / Wirkus, Stephen (Committee member) / Camacho, Erika (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Intuitive decision making refers to decision making based on situational pattern recognition, which happens without deliberation. It is a fast and effortless process that occurs without complete awareness. Moreover, it is believed that implicit learning is one means by which a foundation for intuitive decision making is developed. Accordingly, the present study investigated several factors that affect implicit learning and the development of intuitive decision making in a simulated real-world environment: (1) simple versus complex situational patterns; (2) the diversity of the patterns to which an individual is exposed; (3) the underlying mechanisms. The results showed that simple patterns led to higher levels of implicit learning and intuitive decision-making accuracy than complex patterns; increased diversity enhanced implicit learning and intuitive decision-making accuracy; and an embodied mechanism, labeling, contributes to the development of intuitive decision making in a simulated real-world environment. The results suggest that simulated real-world environments can provide the basis for training intuitive decision making, that diversity is influential in the process of training intuitive decision making, and that labeling contributes to the development of intuitive decision making. These results are interpreted in the context of applied situations such as military applications involving remotely piloted aircraft.
Contributors
Covas-Smith, Christine Marie (Author) / Cooke, Nancy J. (Thesis advisor) / Patterson, Robert (Committee member) / Glenberg, Arthur (Committee member) / Homa, Donald (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Due to the growing concerns on the depletion of petroleum based energy resources and climate change; fuel cell technologies have received much attention in recent years. Proton exchange membrane fuel cell (PEMFCs) features high energy conversion efficiency and nearly zero greenhouse gas emissions, because of its combination of the hydrogen oxidation reaction (HOR) at anode side and oxygen reduction reaction (ORR) at cathode side. Synthesis of Pt nanoparticles supported on multi walled carbon nanotubes (MWCNTs) possess a highly durable electrochemical surface area (ESA) and show good power output on proton exchange membrane (PEM) fuel cell performance. Platinum on multi-walled carbon nanotubes (MWCNTs) support were synthesized by two different processes to transfer PtCl62- from aqueous to organic phase. While the first method of Pt/MWCNTs synthesis involved dodecane thiol (DDT) and octadecane thiol (ODT) as anchoring agent, the second method used ammonium lauryl sulfate (ALS) as the dispersion/anchoring agent. The particle size and distribution of platinum were examined by high-resolution transmission electron microscope (HRTEM). The TEM images showed homogenous distribution and uniform particle size of platinum deposited on the surface of MWCNTs. The single cell fuel cell performance of the Pt/MWCNTs synthesized thiols and ALS based electrode containing 0.2 (anode) and 0.4 mg (cathode) Pt.cm-2 were evaluated using Nafion-212 electrolyte with H2 and O2 gases at 80 oC and ambient pressure. The catalyst synthesis with ALS is relatively simple compared to that with thiols and also showed higher performance (power density reaches about 1070 mW.cm-2). The Electrodes with Pt/MWCNTs nanocatalysts synthesized using ALS were characterized by cyclic voltammetry (CV) for durability evaluation using humidified H2 and N2 gases at room temperature (21 oC) along with commercial Pt/C for comparison. The ESA measured by cyclic voltammetry between 0.15 and 1.2 V showed significant less degradation after 1000 cycles for ALS based Pt/MWCNTs.
Contributors
Liu, Xuan (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Munukutla, Lakshmi (Committee member) / Tamizhmani, Govindasamy (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Previous research suggests that the relation between sport participation and alcohol use is positive, but small in size. Few explanations for this positive relation have been empirically tested. Theories denote that the relation between sport participation and alcohol use is explained by peers and that the relation varies based on the models adolescents are exposed to. This study tested mediators (popularity and friends' alcohol use) and moderators (sport-focus, teammates' alcohol use, gender, popularity, and friends' alcohol use) for the relation between sport participation and alcohol use. Analyses were conducted through path models in Mplus v5.1. The sample included 48,390 adolescents (mean age=15.8 years; 51% female) from the National Longitudinal Study of Adolescent Health. In the self-administered in-school questionnaire, adolescents reported on their activity participation, alcohol use, friendship nominations, and demographic characteristics. Friend indicators were based on friends' self-reported alcohol use. Results suggested that popularity mediated, but did not moderate the relation between sport participation and alcohol use. In contrast, friends' alcohol use moderated, but did not mediate this relation. The relation was positive and strongest for sport-focused adolescents, and for adolescents whose teammates and sport friends used high levels of alcohol. The findings of this study suggest athletes are at an elevated risk for alcohol use, but not all athletes drink. Peers are important predictors, such that, sport participation may be related to alcohol use, partially, because it promotes adolescents' social status. The sport context is also important, such that, athletes are more likely to use alcohol if they are highly involved in sports, and they have sport friends and teammates who drink. Specific types of athletes, such as popular athletes, should be targeted for alcohol use interventions. Intervention programs should also be designed to capture specific aspects of the sport context, such as teams without no tolerance substance use policies, and highly competitive or stressful sports.
Contributors
Vest, Andrea Elaine (Author) / Simpkins, Sandra D. (Thesis advisor) / Updegraff, Kimberly A. (Committee member) / Schaefer, David R. (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This thesis describes several approaches to next generation DNA sequencing via tunneling current method based on a Scanning Tunneling Microscope system. In chapters 5 and 6, preliminary results have shown that DNA bases could be identified by their characteristic tunneling signals. Measurements taken in aqueous buffered solution showed that single base resolution could be achieved with economic setups. In chapter 7, it is illustrated that some ongoing measurements are indicating the sequence readout by making linear scan on a piece of short DNA oligomer. However, to overcome the difficulties of controlling DNA especially ssDNA movement, it is much better to have the tunneling measurement incorporated onto a robust nanopore device to realize sequential reading of the DNA sequence while it is being translocated.
Contributors
Huang, Shuo (Author) / Lindsay, Stuart (Thesis advisor) / Sankey, Otto (Committee member) / Tao, Nongjian (Committee member) / Drucker, Jeff (Committee member) / Ros, Robert (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The purpose of this study was to explore the relationship between childhood maltreatment and juvenile homicide offending. Specifically, this study compared a sample of maltreated male juvenile homicide offenders (N = 51) with non-maltreated male juvenile homicide offenders (N = 364) among the following areas: familial dysfunction and disorganization, mental health issues, academic functioning, prior delinquency, substance abuse and homicide-related crime characteristics. Data was obtained from the following aggregate sources: Supervision Risk Classification Instrument (SRCI), the State Attorney's Recommendation form (SAR), the Predisposition Report (PR), and the Massachusetts Juveniles Screening Instrument 2 (MAYSI-2). Chi square and t-tests were then utilized to compare the two groups and preform analyses. Maltreated male juvenile homicide offenders significantly differed from non-maltreated male juvenile homicide offenders in terms of familial dysfunction and disorganization, academic functioning, prior delinquency and homicide-related crime characteristics. As a result of these significant differences, tailored prevention and treatment efforts were discussed.
Contributors
Johnson, Whitney Randoll (Author) / Roe-Sepowitz, Dominique (Thesis advisor) / Krysik, Judy (Committee member) / Ashford, Jose (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This study examines the differences in demographic and life characteristics between transgender and female prostitutes in a prostitution diversion program and identifies specialized treatment and exiting strategies for transgender prostitutes. The purpose of this study was to develop a better understanding of the transgender experience in prostitution and to contribute to the descriptive literature. Participants were 465 individuals who were arrested for prostitution and attended a prostitution-focused diversion program. Differences found to be significant between transgender and female prostitutes included demographic characteristics, history of childhood sexual abuse, and experience of violence in prostitution. Implications for treatment, exiting strategies and future research are discussed.
Contributors
Schepel, Elizabeth (Author) / Roe-Sepowitz, Dominique (Thesis advisor) / Krysik, Judy (Committee member) / Androff, David (Committee member) / Arizona State University (Publisher)
Created
2011
Description
A synbody is a newly developed protein binding peptide which can be rapidly produced by chemical methods. The advantages of the synbody producing process make it a potential human proteome binding reagent. Most of the synbodies are designed to bind to specific proteins. The peptides incorporated in a synbody are discovered with peptide microarray technology. Nevertheless, the targets for unknown synbodies can also be discovered by searching through a protein mixture. The first part of this thesis mainly focuses on the process of target searching, which was performed with immunoprecipitation assays and mass spectrometry analysis. Proteins are pulled down from the cell lysate by certain synbodies, and then these proteins are identified using mass spectrometry. After excluding non-specific bindings, the interaction between a synbody and its real target(s) can be verified with affinity measurements. As a specific example, the binding between 1-4-KCap synbody and actin was discovered. This result proved the feasibility of the mass spectrometry based method and also suggested that a high throughput synbody discovery platform for the human proteome could be developed. Besides the application of synbody development, the peptide microarray technology can also be used for immunosignatures. The composition of all types of antibodies existing in one's blood is related to an individual's health condition. A method, called immunosignaturing, has been developed for early disease diagnosis based on this principle. CIM10K microarray slides work as a platform for blood antibody detection in immunosignaturing. During the analysis of an immunosignature, the data from these slides needs to be validated by using landing light peptides. The second part of this thesis focuses on the validation of the data. A biotinylated peptide was used as a landing light on the new CIM10K slides. The data was collected in several rounds of tests and indicated that the variation among landing lights was significantly reduced by using the newly prepared biotinylated peptide compared with old peptide mixture. Several suggestions for further landing light improvement are proposed based on the results.
Contributors
Sun, Minyao (Author) / Johnston, Stephen Albert (Thesis advisor) / Diehnelt, Chris Wayne (Committee member) / Stafford, Phillip (Committee member) / Arizona State University (Publisher)
Created
2011
Description
ABSTRACT Cyberbullying has emerged as one of educators' and researchers' chief concerns as the use of computer mediated communication (CMC) has become ubiquitous among young people. Many undesirable outcomes have been identified as being linked to both traditional and cyberbullying, including depression,truancy, and suicide. America and Japan have both been identified as nations whose youth engage frequently in the use of CMC, and may be at a potentially higher risk to be involved in cyberbullying. Time spent using CMC has been linked to involvement in cyberbullying, and gender and age have, in turn, been linked to CMC use - these may play significant roles in determining who is at risk. In order to assess the effects of nationality, gender, and age on cyberbullying involvement among Japanese and American middle school students, a survey exploring these factors was developed and carried out with 590 American and Japanese middles school students (Japan: n = 433 and America: n = 157). MANOVA results indicated that that Americans tend to both use CMC more and be more involved in cyberbullying. In addition, Japanese involvement increased with age, while American involvement did not. There were minimal differences between Americans and Japanese with regards to traditional bullying.
Contributors
Lerner, David (Author) / Nakagawa, Kathryn (Thesis advisor) / Caterino, Linda (Thesis advisor) / Ladd, Becky (Committee member) / Arizona State University (Publisher)
Created
2011