Now showing items 5547-5566 of 14780

• #### Exploring feminist pedagogies

Feminist pedagogical aims and strategies have been discussed in a variety of articles and essays and in a few recent books. This thesis explores feminist discourse on pedagogies and attempts to reconstruct the development of these discourses historically. Early writings on feminist pedagogies were the product of the action-oriented feminism of the 1970s and focused on classroom practices, while recent works, rooted in the larger framework of poststructuralist feminism, engage in a complex theoretical dialogue with the philosophical narratives and counternarratives that oriented emancipatory pedagogies and problematized the boundaries between feminist and other emancipatory pedagogies. The thesis comprises an analysis of the historical and theoretical implications of the literature on feminist pedagogies, and an ethnographic part based on six interviews with Professors of Women's Studies at the University of Arizona, who were asked to discuss the meanings, possibilities and predicaments of feminist teaching in a large research University.
• #### Exploring G-Protein-Coupled Receptors Regulation, Specificity and Controllability of Exosomes Release in the Neuronal Cell Line SH-SY5Y

Parkinson's disease is a neurodegenerative disease characterized by the buildup of aggregated and spread of misfolded alpha-synuclein. How the misfolded alpha-synuclein contributing to the toxicity and death of neuronal cells has been the focal point of research. The spread of alpha-synuclein has been attributed to many mechanisms, one of which is via cell-derived vesicles called exosomes. This project aims to examine the controllability of exosome release. SH-SY5Y, MCF-7 and CHO-K1 cells were transfected with dopamine receptor 3-green fluorescent protein, G-protein receptor 143 or green fluorescent protein and treated with either dopamine or L-DOPA. Medium was harvested and subjected to ultracentrifugation and a silver stain and western blot were performed. There was no significant difference in the total protein in the exosome fraction lanes between the treatment groups or within them. Another aim was to test the specificity of exosomes. Exosomes isolated from SH-SY5Y or MCF-7 were labeled with Exo-Red dye and introduced to wells containing SH-SY5Y, MCF-7 and CHO-K1 cells at room temperature and -4C. At room temperature, exosomes were observed intercellular in all of the cell lines, however, they did not deliver their content. At -4C exosome uptake was halted and they remained on the surface of the cells. Exo-Red labeled SH-SY5Y exosomes were treated with proteinase K and were introduced to CHO-K1 cells at -4C and room temperature. CHO-K1 did not take up exosomes, suggesting exosomes contain one or more necessary proteins needed to interact with the cellular membrane to initiate internalization. CHO-K1 cells were treated with versene to examine the involvement of integrin proteins. Exo-Red labeled SH-SY5Y exosomes were trapped on the surface of CHO-K1 after versene treatment. Lastly, Exo-Red labeled SH-SY5Y exosomes were biotinylated and magnetically captured then introduced to SH-SY5Y and MCF-7 cells and a silver stain and a biotinylated blot were performed. MCF-7 bound more Exo-Red labeled SH-SY5Y exosomes.

• #### Exploring Techniques to Investigate Mule Deer Diet Composition on the Navajo Nation

Knowledge of the diet of wildlife can aid wildlife biologists to better understand how a species functions within a given ecosystem. Numerous studies have identified various avenues to examine diet for species throughout the world. Wildlife biologists have used diet composition variables as a means to better understand habitat use and aid in the management and conservation of mule deer, Odocoileus hemionus. The complexity of deer diet is still unknown, and local wildlife management agencies could improve conservation strategies with more information regarding the breadth of plant selection in deer diet. Researchers have used non-invasive methods, such as microhistology via fecal analyses, to assess diet composition for mule deer. However, microhistology has several drawbacks that include accuracy in identification and differentiation of plant species, and even genus, as well as determination of accurate proportions of taxa ingested. Genetic techniques, such as next-generation sequencing (NGS), present new avenues for analyzing herbivore diets, especially through the amplification and analyses of specific regions of chloroplast DNA (cpDNA). Additionally, few studies have directly compared microhistological and NGS diet analyses results for any wildlife species. My objectives were to compare diet composition results of both microhistological and NGS diet analyses through estimating diet richness, taxonomic resolution, percent diet, and frequency of occurrence of plant taxa across samples. Mule deer fecal samples were collected on the Navajo Nation from summer and winter ranges of two distinct mule deer populations, Chuska and Carrizo. I found far greater richness and resolution from NGS of plant taxa through the identification of a greater number of species and genera among all populations, within seasons. Upon testing both methods for both populations, no significant agreement was identified for percent of families identified in the diet with both methods, across all samples. I found trends of positive correlation in the occurrence of families between both methods for Carrizo summer diet, as well as among genera and families in Carrizo winter diet. Upon further statistical analyses, I found no significant positive correlation in the occurrence of genera and families identified with both methods among all samples. Genetic techniques may present innovative methods for determining mule deer diet in various ecosystems, and may also be applied to a broad range of herbivore diet studies.
• #### Exploring the bisexual alternative: A view from another closet

Research on bisexuality has been relatively nonexistent. In the recent past bisexuality has been viewed as pathological or as a means of denying either homosexuality or heterosexuality. Sexuality is looked at and studied as a dichotomy, polarizing the sexual experience as either "gay" or "straight". Where is the gray area accounted for in this continuum? In this study, 16 female respondents completed questions pertaining to sexual behavior, fantasy and emotional experience. They were also given the Bem Sex Role Inventory to ascertain the relationship between gender identity and sexual orientation. Other issues addressed concerned demographics, AIDS, counseling, and self-esteem.
• #### Exploring the Community of University Indian Ruin

University Indian Ruin is a Classic Period Hohokam platform mound village located in the eastern Tucson Basin. Although portions of the site are well understand, the spatial and social community of the village has not been thoroughly documented. This report seeks to define the community of UIR through archival research, public outreach, and spatial analysis using geographic information systems. The result is a conception of a dynamic community with considerable time depth, which was reliant on certain environmental features, and one that also conforms to the phenomenon of pan-Southwestern abandonment and aggregation in late prehistory.

• #### Exploring the Molecular Mechanisms by which AID Recombinase Interacts with DNA Secondary Structures involved in Cancer

Genomic complexity in non-Hodgkin’s Diffuse Large B-cell Lymphoma (DLBCL) leads to a treatment failure in ~40% of patients. Activation-Induced Cytosine Deaminase (AID), one of the enzymes involved in generating antibody diversity via class switching recombination (CSR) and somatic hypermutation (SHM) of immunoglobulin (Ig) genes in activated B-cells is one mechanism for the introduction of genomic lesions. In previous studies, AID was shown to preferentially bind to super-enhancer (SE) regions within the genome, but 26% of AID targets were not within the SE regions. The mechanism by which AID interacts with SE elements and its off-target interactions still remains a mystery. Recent evidence suggests that AID may cause genomic lesions in DLBCL via interaction with oncogenes such as MYC and BCL2 resulting in mutations and translocations. Sequences within the MYC promoter contain the four-nucleotide AID target sequence (WRCY) and highly G-rich sequences known to form G-quadruplex DNA secondary structures. We hypothesize that key DNA secondary structures act as recruiting elements for aberrant AID activity at promoters and SEs of key genes involved in the development of DLBCL. Here, we first sought to determine whether known AID DNA targets have the potential to form G-quadruplex DNA secondary structures. The data collected from activated mouse B-cells showed 90% of the AID targets contained sequences that could potentially form G-quadruplexes and the data collected from the human Ramos cell line showed 100% of the sequences had the potential to form G-quadruplexes. To further study our hypothesis we used the techniques circular dichroism (CD) and the electrophoresis motility shift assay (EMSA) to explore the potential interaction between AID and the BCL2 and MYC G-quadruplexes. We observed no significant interactions between AID and these two G-quadruplexes, however further experimentation with different conditions and molecular techniques may show interaction. Additional studies will not only provide key insight into the genomic instability within DLBCL, but will also provide a potential mechanism by which AID is recruited to its DNA targets.
• #### Exploring the Relationship Between Accreditation and For-Profit Higher Education Institutions

This paper explores the relationship between for-profit higher education institutions and accreditation. Two sets of research questions are examined. The first set of research questions looks at the characteristics of for-profits regionally accredited versus nationally accredited. The second set of research questions looks at the characteristics of for-profits that keep accreditation versus those who lose accreditation. Analysis is conducted using panel longitudinal data that has been merged together from the Integrated Postsecondary Education Data System (IPEDS), the Office of Federal Student Aid, and the Postsecondary Education Participation System (PEPS). Both descriptive statistics and logistic regressions are used to explore the hypotheses in this paper. The findings contribute to the field’s understanding of for-profits and accreditation. This paper found in general for-profits are not losing accreditation. Regionally accreditors in particular are not revoking accreditation. Larger for-profits are more likely to be regionally accredited. Revenue, enrollment, and number of campuses, in particular seem to keep institutions from losing accreditation. Policy continues to be created (or reversed) to address concerns over for-profits but it has done so without enough statistical analysis to backup those decisions. The relationship between for-profits and accreditation is mutually beneficial and therefore needs to be further researched and addressed.
• #### Exploring the Success and Defeat of Ronda Rousey: A Content Analysis of Twitter and Newspaper Coverage from 2014-2016

Scholarly research has analyzed how female athletes use their social media platforms and how they are represented in news media coverage. However, no scholarly literature has specifically looked at Ronda Rousey, an American mixed martial artist. The current study used a quantitative content analysis to examine how Rousey has utilized her Twitter account as well as how local and national newspapers in the United States framed coverage of Rousey between 2014 to 2016. For the tweets, content, referring to pictures that Rousey posted, was the most popular category; the second most prevalent category was promotional, referring to tweets that promoted upcoming events or sponsorships. Rousey mainly used her Twitter to post pictures of herself and promote her personal brand. For the newspaper articles, the most frequently used frames were agency, powerless, and goals and ambitions. Two new frames emerged from the current study – fame, referring to Rousey’s film career, and relations, referring to Rousey’s personal life and relationships. The newspapers were predominantly neutral in their coverage of Rousey throughout the three-year study period. This case study is important because it found that Rousey was framed in a way that differed from previous research. The findings in this study demonstrate that Rousey was not marginalized in newspaper coverage or portrayed in a negative manner, as other female athletes have been in the past. Rather than focusing on her appearance or sexuality, the news coverage highlighted Rousey’s success and athletic achievements.

• #### Exploring the Use of Environmentally Friendly Fertilizers for Desert Vegetable Production

Field experiments were conducted from 2011 through 2017 to (1) evaluate the responses of vegetable crops to Crystal Green (CG) in comparison to conventional phosphorus (P) fertilizers and (2) to investigate alternative nitrogen management strategies for desert spinach production. The earlier experiments spanned from 2011 to 2016 and employed a novel P source (struvite), a granule-like based P fertilizer marketed as “Crystal Green®”. Responses of Iceberg lettuce (Lactuca sativa), carrot (Daucus carota sativus), onions (Allium cepa) and potato (Solanum tuberosum) to struvite (CG), triple super phosphate (TSP), and monoammonium phosphate (MAP) were compared. Our results revealed that CG compared favorably to TSP but not to MAP when applied as a sole P source. However, certain blends or co-granulated formulations of MAP and CG often provided superior yields than MAP alone. The later studies comprised of four experiments performed from 2016 to 2017. These studies employed various nitrogen (N) sources. The N sources included enhanced efficiency N fertilizers and conventional N products applied at 0,150, and 300 kg N/ha in 2015 and 0, 100, and 200 kg N/ha in 2016. We observed that spinach yields were often maximized at N rates less than 200 kg N/ha considerably below standard commercial practices. The data also revealed that the N source fused safe nitrate (FUSN), a product developed as a substitute for dry ammonium nitrate, generally produced favorable spinach responses relative to the other dry N sources such as ammonium sulfate (AS) and urea. The controlled release fertilizer (CRF) products were observed to be effective N sources for spinach production and are viable options for enhanced efficiency. Contrarily, the nitrification inhibitors caused ammonium damage and yield depression. Overall, the experiments proved that environmentally friendly N and P fertilizers are effective nutrient sources for vegetable production on desert soils.
• #### Exploring uncertainty in first pregnancy

A qualitative study was conducted to explore the phenomenon of uncertainty in women experiencing a first uncomplicated pregnancy. Ten subjects, three from each of the first two pregnancy trimesters and four from the third pregnancy trimester, comprised the sample. Subjects ranged in age from 19 years to 30 years and lived in a southwestern city. Interviews were conducted in the subjects' homes or in the researcher's office over a four month period. Constant comparative analysis of data permitted the researcher to elicit specific uncertainties by trimester and the meaning of uncertainty to women involved in a normal change process. Implications for nursing highlight the need to provide continuity of care from office to hospital and within the hospital environment itself. Providing support by functioning as a mediator between the physician and the patient, nurses could contribute to the pregnant woman's positive perception of her experience. In addition to traditional third trimester childbirth education, classes for first and second trimester women are recommended.
• #### Exposed Memory: Weathering of Regional Architecture

Weathering introduces a language of durability and change throughout time. Architecture and its materials are constituents of place, as is the way they weather and age. The intent of this research is to analyze regional weathering characteristics specific to the American Southwest as a reflection of a sense of belonging that evolves over time.
• #### Exposure to chlorpyrifos and use of pesticides in Arizona

This study of pesticide use and exposure in the Arizona NHEXAS sample explored demographic variation in pesticide use and the feasibility of predicting the subjects' urinary TCPY (a chlorpyrifos metabolite) using questionnaire data. A variety of demographic differences in pesticide use patterns such as frequency of personal application, use of professional exterminators, and frequency of use outside the home were found. In contrast, there were few demographic differences in TCPY, although mean TCPY was higher than in earlier epidemiological studies. Two mulitvariate (multiple regression) methods of predicting TCPY from questionnaire responses were tested. The first method combined pesticide use questions into a scale; the second method treated them separately. R2s were similar and below .25 using either method. Including only subjects reporting some pesticide use raised the R2 to .35. These results suggest that questionnaire responses cannot predict exposure accurately enough to be useful proxies for biological samples.
• #### Expression of a mammalian cytochrome P-450 in Nicotiana tabacum for bioremediation of PCB contaminated soils

Polychlorinated biphenyls (PCBs) are resistant to metabolism in most animal species. The dog has the unique ability to metabolize and eliminate certain PCB congeners, as a result of the activity of the cytochrome P450 isozyme PBD-2. An expressible cDNA coding for PBD-2 has been introduced into the genome of tobacco plants. The PBD-2 cDNA coding sequence and a screenable marker gene coding for neomycin phosphotransferase II were introduced into tobacco leaf disks using a binary Agrobacterium tumefaciens vector system. Southern and Western blot analysis have confirmed chromosomal integration of the cDNA and expression of the PBD-2 polypeptide. Differential centrifugation and Western blot analyses have shown the PBD-2 protein to be associated with a membrane fraction in transgenic tobacco leaf homogenates. Measurements of marker enzymes from linear sucrose gradient fractions and Western blotting show the PBD-2 protein to be associated with the endoplasmic reticulum. Our goal is to develop transgenic plants in which the PBD-2 protein metabolizes PCBs, thus providing a novel method for bioremediation of PCB-contaminated soils.

• #### Expressions of hsc/hsp70 cDNAs in bacteria and comparison with tissue-isolated proteins.

Rat hsc70 and human hsp70 have been expressed in bacteria using the T7 polymerase system. The recombinant proteins, which were the major proteins in E.coli, had the same molecular weights as the tissue-isolated proteins and were immunoactive with hsc70/hsp70 antibodies. ATP binding assay by equilibrium dialysis showed a K$\sb{\rm d}$ for ATP of 0.44 $\mu$M. At saturation, 0.4 mole of ATP was bound per mole of hsc70. Both recombinant and tissue-isolated hsc70/hsp70 have ATPase activities. The denatured substrate, reduced carboxyl methylated $\alpha$-lactalbumin (RCMLA), stimulated ATPase rates of bovine tissue-isolated hsc70/hsp70, but the ATPase rates of rat skeletal muscle and recombinant hsc70 were not changed upon the adding of RCMLA. The analysis of two-dimensional gels showed hsc70/hsp70 isolated from different sources had different isoform patterns. It is speculated that each isoform may have its own substrate specificity.
• #### An extended cavity, self focussing laser optical head

A feasibility study of an "Extended Cavity, Self Focussing Laser Optical Head" for optical data storage applications is presented. A general description of the proposed device is discussed followed by a prediction of its dynamic operation. This is verified by a one dimensional computer model, simulating dynamic laser head behavior. Transient laser phenomena such as longitudinal mode competition and laser frequency modulation are investigated as applicable to the device operation. The self-focussing concept is confirmed by the passive cavity experiment and a geometrical computer model of the cold cavity (i.e. no gain medium).
• #### Extending DEVS-Scheme for control of an oxygen production test bed

This thesis describes an implementation of real-time simulation and control in the DEVS-Scheme environment. The plant is described by discrete event models developed within the event-based control paradigm. A model of the controller is employed to validate its design against a model of the plant. The same model is then migrated over to actual operation by interfacing it to a programmable sensor/actuator interface unit. A system entity structure is employed to generate both the simulation and execution versions of the controller. This methodology is supported by extensions to the DEVS-Scheme simulation environment which facilitate its use for real-time control. As an example, an intelligent controller is developed to control temperature and pressure of an oxygen production prototype system which converts carbon dioxide to oxygen. Such a system is eventually intended to operate autonomously on Mars.