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In vitro gametogenesis (IVG) research has been growing in countries like Japan, US, and China after the development of stem cell research and other scientific advancements as well as because of the perception of infertility as a domestic and international problem. IVG research’s progress has been deliberated internationally, with discussion of questions, challenges, and possibilities that have arisen and may arise in the future as the technology is adopted by different countries. The first section introduces the meaning of IVG, explains the importance of review by scientists and citizens for IVG, and describes a rise in infertility reported in multiple developed countries that could be addressed by IVG. The second section discusses IVG’s applications and implications using 5 ethical categories articulated by Obama’s Presidential Commission for the Study of Bioethical Issues: Public Beneficence, Responsible Stewardship, Intellectual Freedom and Responsibility, Democratic Deliberation, and Justice and Fairness. These five ethical principles were intended for analysis of emerging technologies, and IVG is an emerging technology with possible integration into clinical settings. Among the principles, it seemed that a major weak point of inquiry concerns LGBT+ and disability inclusion, especially of gender dysphoric and transgender people who may experience higher rates of infertility and have a harder time conceiving due to a mix of discrimination, gender dysphoria, and infertility due to hormone replacement therapy (HRT) treatment or gender/sex reassignment surgeries (GRSs/SRSs) that may impair or remove reproductive body parts. A number of other ethical considerations arise about this technology.
ContributorsVillarreal, Lance Edward (Author) / Maienschein, Jane (Thesis director) / Ellison, Karin (Committee member) / Wilson-Rawls, Jeanne (Committee member) / School of Life Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Fusion protein immunotherapies such as the bispecific T cell engager (BiTE) have displayed promising potential as cancer treatments capable of engaging the immune system against tumor cells. It has been shown that chlorotoxin, a 36-amino peptide found in the venom of the deathstalker scorpion (Leiurus quinquestriatus), binds specifically to glioblastoma (GBM) cells without binding healthy tissue, making it an ideal GBM cell binding moiety for a BiTE-like molecule. However, chlorotoxin’s four disulfide bonds pose a folding challenge outside of its natural context and impede production of the recombinant protein in various expression systems, including those relying on bacteria and plants. To overcome this difficulty, we have engineered a truncated chlorotoxin variant (Cltx∆15) that contains just two of the original eight cystine residues, thereby capable of forming only a single disulfide bond while maintaining its ability to bind GBM cells. We further created a BiTE (ACDClx∆15) which tethers Cltx∆15 to a single chain ⍺-CD3 antibody in order to bring T cells into contact with GBM cells. The gene for ACDClx∆15 was cloned into a pET-11a vector for expression in Escherichia coli and isolated from inclusion bodies before purification via affinity chromatography. Immunoblot analyses confirmed that ACDClx∆15 can be expressed in E. coli and purified with high yield and purity; moreover, flow cytometry indicated that ACDClx∆15 is capable of binding GBM cells. These data warrant further investigation into the ability of ACDClx∆15 to activate T cells against GBM cells.
ContributorsSchaefer, Braeden Scott (Author) / Mor, Tsafrir (Thesis director) / Mason, Hugh (Committee member) / Cook, Rebecca (Committee member) / School of Life Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Infectious disease in wild animals has historically been a challenge that is difficult to overcome, primarily because isolating a disease outbreak to prevent further transmission in these types of populations is nearly impossible. Wild animals are free to roam, and humans often have limited means of tracking infection in populations. Vaccines and treatments can be formulated but are often somewhat impractical for wild populations because it is not feasible to vaccinate or treat every member in a susceptible community. One such pathogen, Batrochochytrium dendrobatidis (Bd) is infecting amphibian populations around the world to the point where many species are already extinct. Even though finding an effective preventative for the fungal pathogen may not mean that I am able to reach every member in a population, it may mean the difference between extinction and eventual release back into the wild for threatened populations.
In this study I hoped to create an attenuated version of Batrochochytrium dendrobatidis, by using a novel laser technology: SEPHODIS. This laser technology disrupts hydrogen bonds between proteins in the lumen of the cell while simultaneously preserving the membrane and associated proteins on the outside of the cell. This process ultimately affects the pathogenicity of the target but leaves identity markers intact so that the host immune system may recognize the pathogen and create antibodies against it. The laser was ultimately effective at killing Bd fungal cells, and I did observe a significant change in the appearance of the cells. However, samples obtained after exposure to the laser were contaminated and more research is needed to determine if SEPHODIS could be a feasible method for vaccine production.
In this study I hoped to create an attenuated version of Batrochochytrium dendrobatidis, by using a novel laser technology: SEPHODIS. This laser technology disrupts hydrogen bonds between proteins in the lumen of the cell while simultaneously preserving the membrane and associated proteins on the outside of the cell. This process ultimately affects the pathogenicity of the target but leaves identity markers intact so that the host immune system may recognize the pathogen and create antibodies against it. The laser was ultimately effective at killing Bd fungal cells, and I did observe a significant change in the appearance of the cells. However, samples obtained after exposure to the laser were contaminated and more research is needed to determine if SEPHODIS could be a feasible method for vaccine production.
ContributorsRidley, Kylie Madison (Author) / Collins, James (Thesis director) / Tsen, Kong-Thon (Committee member) / Brus, Evan (Committee member) / School of Art (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Colorectal cancer is the third most common type of cancer that affects both men and women and the second leading cause of death in cancer related deaths[1, 2]. The most common form of treatment is chemotherapy followed by radiation, which is insufficient to cure stage four cancers[3]. Salmonella enteric has long been shown to have inherent tumor targeting properties and have been able to penetrate and exist in all aspects of the tumor environment, something that chemotherapy is unable to achieve. This lab has developed a genetically modified Salmonella typhimurium (GMS) which is able to deliver DNA vaccines or synthesized proteins directly to tumor sites. These GMS strains have been used to deliver human TNF-related apoptosis inducing ligand (TRAIL) protein directly to tumor sites, but expression level was limited. It is the hope of the experiment that codon optimization of TRAIL to S. typhimurium preferred codons will lead to increased TRAIL expression in the GMS. For preliminary studies, BALB/c mice were subcutaneously challenged with CT-26 murine colorectal cancer cells and treated with an intra-tumor injection with either PBS, strain GMS + PCMV FasL (P2), or strain GMS + Pmus FasL). APC/CDX2 mutant mice were also induced to develop human colon polyps and treated with either PBS, strain GMS + vector (P1), P2, or P3. The BALB/c mouse showed statistically significant levels of decreased tumor size in groups treated with P2 or P3. The APC/CDX2 mouse study showed statistically significant levels of decreased colon polyp numbers in groups treated with P3, as expected, but was not significantly significant for groups treated with P1 and P2. In addition, TRAIL was codon optimized for robust synthesis in Salmonella. The construct will be characterized and evaluated in vitro and in vivo. Hopefully, the therapeutic effect of codon optimized TRAIL will be maximal while almost completely minimizing any unintended side effects.
ContributorsCrawford, Courtney Rose (Co-author) / Crawford, Courtney (Co-author) / Kong, Wei (Thesis director) / Shi, Yixin (Committee member) / Fu, Lingchen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Amphibians around the world are suffering the effects of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Whenever amphibians are housed in captivity, they must go through a decontamination protocol to ensure they are not infected with diseases such as Bd. Itraconazole is the most commonly used fungicide used in these protocols. This study set out to determine if Bd could develop resistance or tolerance to itraconazole. Two 24 well plates were prepared with different concentrations of itraconazole with Bd zoospores added. Plate 1 had concentrations similar to what animals are currently being treated with in decontamination protocols. Plate 2 had concentrations at and below the published minimum inhibitory concentration values (MIC). Plate 1 displayed the ability of itraconazole to kill Bd sporangia with higher concentrations and Plate 2 showed that even under published MIC values, Bd still struggled to complete its reproductive cycle. I find the evolution of a resistant/tolerant strain of Bd unlikely given the efficacy of this drug, the sensitivity of Bd to itraconazole, and the lack of evidence of the completion of Bd’s reproductive cycle under the conditions used in this study.
ContributorsSommer, Bradley Dean (Author) / Collins, James (Thesis director) / Roberson, Robert (Committee member) / Brus, Evan (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The prevalence of excessive weight gain (obesity) has steadily increased since about 1980. Excessive weight gain is associated with many comorbidities; thus, a successful treatment is needed. The most common form of non-surgical treatment for excessive weight gain is caloric restriction with the intent to reduce body weight by 10%. Though this treatment is successful at reducing body weight, it often fails at maintaining the weight loss. Dietary menthol has been suggested as a possible treatment for excessive weight gain and has produced promising results as a preventative method for excessive weight gain. Our studies aimed at reducing weight regain and maintaining caloric restriction by feeding male Sprague-Dawley rats 0.5% dietary menthol during a period of caloric restriction, aimed at reducing their body weight by 10%, following an experimental period where the rats were fed a high-fat diet (HFD) or low-fat diet (LFD). The effects of the dietary menthol were observed during the weight regain period following the caloric restriction period. Two studies were conducted, and both were unable to achieve a maintenance of weight loss following caloric restriction, although our first study was able to produce a delay in weight regain and did not show any evidence of increased thermogenesis in menthol-treated rats. Our findings differ from the findings of previous studies on dietary menthol which could possibly be due to species effects, differences in procedures, age effects, or effects of different fatty acid compositions. The contrasting results in our studies could be due to genetic differences between litters used or a difference in manufacturing of the menthol diet between studies. Given the partial response to menthol in the first study, it can be suggested that the concentration of 0.5% may be below the threshold of menthol sensitivity for some rats. Future research should focus on increasing the concentration of dietary menthol from 0.5% to 1%, since the current concentration did not yield a reduction in weight regain or maintenance of caloric restriction.
ContributorsRascon, Kasandra (Author) / Herman, Richard (Thesis director) / Sweazea, Karen (Committee member) / Kim, Minjoo (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Human activity produces ambient noise that potentially alters species’ abilities to communicate with each other—among other impacts. Given that birds are known to be sensitive to structural changes in habitat and highly communicative through sound, it is beneficial to understand how changing acoustic ecologies and ambient noise impact birds’ ability to communicate in their respective environments. In this study, mockingbird calls from an urban, desert, and intermediate study site were recorded and analyzed for differences in acoustic properties. Acoustic properties such as frequency and amplitude differed significantly across sites as it was determined that mockingbirds in urban areas increase both the peak frequency and amplitude of their calls in order to communicate. This study identifies what these changes in acoustic properties mean in relation to the survival and conservation of birds and concludes with recommendations for novel research.
ContributorsReynolds, Bailey Susana (Author) / Pearson, David (Thesis director) / Walters, Molina (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Constructed treatment wetlands (CTW) are being increasingly utilized in urbanized areas as a cost-effective and environmentally-friendly method for treating wastewater. CTWs can be especially useful for urban areas in aridland environments because they facilitate the reuse of water during water shortages. In my study, I determined the rates at which the aboveground and belowground emergent macrophytes sequestered nitrogen in a 42 ha aridland CTW in Phoenix, Arizona, USA. To do so, I measured foliar nitrogen content in aboveground and belowground biomass of three plant species groups (Typha latifolia + Typha domingensis, Schoenoplectus acutus + Schoenoplectus tabernaemontani, and Schoenoplectus californicus). Using these data, I calculated aboveground and belowground nitrogen budgets for the three species groups annually from 2011 to 2018.
Aboveground nitrogen content showed a maximum in 2011, decreasing until 2015, increasing again until 2017, and dropping in 2018; belowground nitrogen content showed the opposite temporal trend. Because foliar nitrogen content was assumed to be relatively constant over time, my data suggested that belowground nitrogen content increased between 2011 and 2015 and decreased between 2015 and 2017. Aboveground nitrogen content underwent fluctuations due to fluctuations in aboveground biomass. This occurred due to ‘thatching’, or events of widespread toppling of large macrophyte stands. The ratio of aboveground to belowground biomass can vary widely in the same CTW. My findings suggested that managing senesced aboveground plant material in CTWs may optimize the CTW’s ability to sequester nitrogen. Further research is needed to determine the best management strategies, as well as its possible implications.
Aboveground nitrogen content showed a maximum in 2011, decreasing until 2015, increasing again until 2017, and dropping in 2018; belowground nitrogen content showed the opposite temporal trend. Because foliar nitrogen content was assumed to be relatively constant over time, my data suggested that belowground nitrogen content increased between 2011 and 2015 and decreased between 2015 and 2017. Aboveground nitrogen content underwent fluctuations due to fluctuations in aboveground biomass. This occurred due to ‘thatching’, or events of widespread toppling of large macrophyte stands. The ratio of aboveground to belowground biomass can vary widely in the same CTW. My findings suggested that managing senesced aboveground plant material in CTWs may optimize the CTW’s ability to sequester nitrogen. Further research is needed to determine the best management strategies, as well as its possible implications.
ContributorsCrane, Austin Matthew (Author) / Childers, Daniel (Thesis director) / Sanchez, Christopher (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
As the public becomes increasingly aware of the morality of wildlife institutions like zoos and aquariums, these places are now having to face possible negativity and lack of support from their communities. In light of this, these institutions are now focusing their goals and efforts towards conservation education and outreach programs in order to continue contributing to biodiversity conservation. Research has proven that wildlife institutions like zoos and aquariums are effective ways to teach the community about wildlife and conservation. To measure how effective aquariums are at educating their patrons on conservation, a short survey was administered to 100 patrons of the OdySea Aquarium in Scottsdale, Arizona. The object of the survey was to assess which type of conservation messaging was preferred by the general public and if patrons of the aquarium were likely to engage in pro-conservation behaviors after their visit. It was found that the majority of respondents preferred interactive exhibits as their choice to learn about conservation and wildlife. In addition, almost all respondents agreed that they would continue practicing behaviors that supported pro-conservation actions after their visit to the aquarium. My results also showed that patrons of the aquarium were well educated about plastic pollution and the rehabilitation that OdySea accomplishes for the sea turtles due to their overexpression of mentioning plastic in their open-ended questions. My findings indicate that this aquarium is succeeding in promoting conservation and wildlife education as well as supporting cultivation within their patrons that will benefit the future health of this planet.
ContributorsErhardt, Jordan Hanna (Author) / Schuster, Roseanne (Thesis director) / Cheng, Samantha (Committee member) / School of Life Sciences (Contributor) / Division of Teacher Preparation (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The purpose of this study was to examine the overall maintenance of behavior during the 12 to 24 month period of the Stand&Move@Work study and the impact of implementation factors (i.e., facilitators, advocate activity, and the amount of strategies used) on behavior change. The design of the study was a cluster randomized trial which was facilitated by researchers for the first 12 months of the study. The primary aim of the study was to examine the maintenance of behavior change (i.e., sitting time) at the 12 month and 24 month marks using objectively measured sedentary behavior (activPAL micro). The secondary aim of the study was to examine the impact of implementation factors (i.e., facilitators, advocate activity, and the amount of strategies used) on behavior change during the 12 through 24 months maintenance period. Participants (N=630) included full-time, caucasian, middle-aged office workers. For the primary aim, descriptive means were used to cluster for observations within-persons and were adjusted for age, gender, race, job-type, and ordering effects.. For the secondary aim, descriptive means adjusted for workplace culture and environment were computed. At the 24 month mark, participants spent 280.67 ± 87.67 min/8hr workday sitting and 161.94 ± 85.87 min/8hr workday standing. The top performing worksites displayed reductions in sitting time which largely translated into standing time by about 30 minutes per 8 hour workday at 24 months. Feasibility findings indicated that implementation strategies do not show differences between the top 25% and bottom 25% performing worksites. This study provides insight to implementation strategies for interventions in the workplace.
ContributorsTong, Alyssa Taylor (Author) / Buman, Matthew (Thesis director) / Larouche, Miranda (Committee member) / Estabrooks, Paul (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05