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- Creators: College of Liberal Arts and Sciences
- Creators: School of Molecular Sciences
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Description
With a quantum efficiency of nearly 100%, the electron transfer process that occurs within the reaction center protein of the photosynthetic bacteria Rhodobacter (Rh.) sphaeroides is a paragon for understanding the complexities, intricacies, and overall systemization of energy conversion and storage in natural systems. To better understand the way in which photons of light are captured, converted into chemically useful forms, and stored for biological use, an investigation into the reaction center protein, specifically into its cascade of cofactors, was undertaken. The purpose of this experimentation was to advance our knowledge and understanding of how differing protein environments and variant cofactors affect the spectroscopic aspects of and electron transfer kinetics within the reaction of Rh. sphaeroides. The native quinone, ubiquinone, was extracted from its pocket within the reaction center protein and replaced by non-native quinones having different reduction/oxidation potentials. It was determined that, of the two non-native quinones tested—1,2-naphthaquinone and 9,10- anthraquinone—the substitution of the anthraquinone (lower redox potential) resulted in an increased rate of recombination from the P+QA- charge-separated state, while the substitution of the napthaquinone (higher redox potential) resulted in a decreased rate of recombination.
ContributorsSussman, Hallie Rebecca (Author) / Woodbury, Neal (Thesis director) / Redding, Kevin (Committee member) / Lin, Su (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
The purpose of the study was to examine the associations of protective (ethic identity, parent-child closeness) and risk (perceived discrimination, parent-child role reversal) factors with mental and behavioral health in 2nd generation Cambodian American (CA) young adults. A total of 66 participants who identified as being 2nd generation CA young adults aged 18-25 years old were recruited to participate in this cross-sectional. Reliable and valid measures were used to assess protective and risk factors and mental (depressive, anxiety, somatic symptoms) and behavioral health outcomes (alcohol and drug use). We used descriptive statistics to describe sample characteristics and study variables and conducted multiple regression analysis to examine the associations of factors with each of the 5 health outcomes. The findings suggested that peer discrimination was positively and significantly associated with depressive (β = 0.42, p = 0.023; R2 = 0.397) and somatic symptoms (β = 0.63, p = 0.000, R2 = 0.554). Father role-reversal was also found to be negatively and significantly associated with predicting CA young adults’ anxiety symptoms (β = -0.32, p = 0.005, R2 = 0.456).
Majority of the CA young adults have perceived racial/ethnic discrimination in the community. Furthermore, perceived discrimination has been positively associated with their depressive and somatic symptoms, suggesting a need to address racial/ethnic discrimination issues to promote positive mental health in this population. It is important for school/work personnel and healthcare providers to assess CA young adults’ discrimination experiences, and have the sufficient resources (e.g., education, support groups) to prevent negative consequences associated with discrimination.
Majority of the CA young adults have perceived racial/ethnic discrimination in the community. Furthermore, perceived discrimination has been positively associated with their depressive and somatic symptoms, suggesting a need to address racial/ethnic discrimination issues to promote positive mental health in this population. It is important for school/work personnel and healthcare providers to assess CA young adults’ discrimination experiences, and have the sufficient resources (e.g., education, support groups) to prevent negative consequences associated with discrimination.
ContributorsOu, Jason Heng (Author) / Chen, Angela Chia-Chia (Thesis director) / Sangalang, Cindy (Committee member) / Miroballi, Barbara (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
This study was conducted to observe the effects of vitamin C supplementation upon the expression of sICAM-1 in asthmatic subject. Two groups were created, each with a sample size of 4 subjects. One group was the vitamin C group (VC) and the other was the placebo group (PL). The study was analyzed through observing concentrations of biomolecules present within samples of blood plasma and nasal lavages. These included vitamin C, sICAM-1 expression, and histamine. The following P-values calculated from the data collected from this study. The plasma vitamin C screening was p=0.3, and after 18 days of supplementation, p=0.03. For Nasal ICAM p=0.5 at Day 0, p=0.4 at Day 4, and p=0.9 at Day 18. For the Histamine samples p=0.9 at Day 0 and p=0.9 at Day 18. The following P-values calculated from the data collected from both studies. The plasma vitamin C screening was p=0.8, and after 18 days of supplementation, p=0.03. The change of vitamin C at the end of this study and the combined data both had a P-value that was calculated to be lower than 0.05, which meant that this change was significant because it was due to the intervention and not chance. For Nasal ICAM samples p=0.7 at Day 0, p=0.7 at Day 4, and p=1 at Day 18. For the Histamine p=0.7 at Day 0 and p=0.9 at Day 18. This study carries various implications although the study data was unable to show much significance. This was the second study to test this, and as more research is done, and the sample size grows, one will be able to observe whether this really is the mechanism through which vitamin C plays a role in immunological functions.
ContributorsKapadia, Chirag Vinay (Author) / Johnston, Carol (Thesis director) / LaBaer, Joshua (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
Methods of second language (L2) teaching should involve exposure to authentic forms to facilitate the development of proficiency and fluency. Exposure to authentic forms is important because prior research has shown that natural language discourse uses mostly prefabricated linguistic units (prefabs-formulaic language) that aid in developing linguistic competence and fluency; this occurs because learners' cognitive load is decreased when they are able to retrieve prefabricated wholes from their L2 repertoire as they produce L2 discourse (Erman & Warren, 2000). An effective method of acquiring prefabricated constructions as single units of meaning or structure is repetition of exposure to whole collocations (words that occur together in fixed phrases), since attention will shift from the individual constituents of the phrase to the unit as a whole as the meaning-bearing stored form (Bybee et al., 2006). Authentic materials (materials produced by native speakers for native speakers) contain a substantial number of prefabricated meaning units that are characteristic of native-speaker produced natural language. Compared to traditional L2 classroom approaches, authentic materials are more likely to engage learners due to the range of options available for learner interest; there is a psychological benefit for students who can be certain that their progress with authentic materials is tantamount to progress outside the classroom setting (Berardo, 2006; Ugalde, 2008). The efficacy of exposure to authentic forms can also be explained by virtue of the fact that it promotes incidental acquisition, which is the primary manner by which language is learned (Ellis & Wulff, 2015); it does so through facilitating implicit pattern recognition of exemplar structures. The research concludes with a discussion of why pedagogical approaches should seek to incorporate formulaic language for learners to achieve fluency.
ContributorsGuerithault, Nicolas Owen (Author) / Lafford, Barbara (Thesis director) / Martinez, Jacqueline (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The Downtown ASU campus Bio 201 and 202 anatomy labs are planning on revising the method in which students are presented and evaluated on lab material for the Fall 2016 semester. The goal of this thesis project was to analyze the methods used in previous semesters in order to determine which method, if any, proved to be the most effective means of evaluation for the students. The general setup of the anatomy labs is that the students come to lab, receive that week's instruction, and then are quizzed on that week's material at the beginning of their next lab. Then roughly every five new segments there is a practical covering the cumulative information from the last five segments. Therefore it is imperative to analyze the current and previous methods of evaluation in order to find which one has the strongest correlation with an individual's quiz performance and their practical grade. Since the Fall 2014 semester three different quiz types have been used in lab while the practical has remained the same. The three different types of quizzes are written, turning point, and no quiz; in order to determine which method was most effective overall practical averages for each student was compared to their corresponding quiz average. This data was put into Excel and used to generate a graph in order to determine the r-squared values to determine which had the strongest correlation. The results showed that no matter what quiz type was used there was no statistically significant correlation between quiz performance and practical performance; in fact practical averages were nearly identical between semesters for Bio 201 and 202. However, visual analysis of the graph demonstrated that certain quiz methods did seem to be more effective than others. For Bio 201 it seemed that written quizzes were the most effective means of evaluation, while in Bio 202 the turning point quizzes were best.
ContributorsOlson, Zachary G (Author) / Kingsbury, Jeffrey (Thesis director) / Legere, Jenny (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
DescriptionThis creative project provides documentation and an exploration of my interactions with individuals encountered while hitchhiking up the west coast.
ContributorsGerber, Evan Howard (Author) / Kashiwagi, Dean (Thesis director) / Kashiwagi, Jacob (Committee member) / W. P. Carey School of Business (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Many stressors today are psychological rather than physical and are influenced by the brain's perception of the stressor. The peripartum period is a particularly volatile time that is susceptible to new and stronger stressors. This current study investigates the relationship between self-reported perceived stress levels and physiological cortisol reactivity levels in new mothers at the 12-week postpartum time point. In addition, it examines the relationship between the mother and infants' physiological cortisol reactivity levels at 12-weeks postpartum. This current study is part of a longitudinal study and assessed these two correlations for 181 mother-infant dyads from a low income Mexican American population. The self-reported stress levels were assessed using the 4-item Perceived Stress Scale (PSS) and the cortisol reactivity data was gathered using four salivary cortisol samples taken from both mother and infant surrounding 5 interaction tasks and analyzed using Area Under the Curve with respect to ground (AUCg). Unexpectedly, the results found no correlation between perceived and physiological stress levels in the mothers, with a Pearson correlation of 0.114 and a p-value of 0.129. However, there was a positive correlation between mother and infant cortisol reactivity, with a correlation of 0.632 and a p-value less than 0.0001. This early postpartum period plays a significant role in developing HPA axis regulation for infants and developing productive mother-infant interactions. The physiological and psychological risks of chronically elevated stress for both mothers and children were addressed in this study as well, with implications for means to address and mitigate potential cortisol dysregulation.
ContributorsRegan, Emily Nicole (Author) / Washo-Krupps, Delon (Thesis director) / Crnic, Keith (Committee member) / Hanna, Mariam (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
A single splice site mutation in the mitochondrial methionyl-tRNA formyltransferase (MTFMT) gene is described in three patients with mitochondrial disease from two unrelated families. Nuclear-encoded MTFMT localized to the mitochondria is responsible for the formylation of Met-tRNAMet necessary for the initiation of translation in the mitochondria. This mutation has been associated with mitochondrial disease (oxidative phosphorylation deficiencies due to a decreased expression of MTFMT), Leigh syndrome, and developmental delay. However, there is significant phenotypic variation between patients, which is not uncommon in mitochondrial disease. Though the variation was not clearly elucidated through analysis of gene expression, this data supported two potential gene modifiers as well as proposed an alternative energy producing pathway in the cell—glutamine metabolism. This nonsynonymous mutation at site c.626C>T generates a splicing suppressor in the coding region on exon 4 resulting exon skipping in almost all transcripts in homozygotes during splicing. It is hypothesized that antisense oligotherapy will be effective in rescuing this mutation by inhibiting the splice silencer and promoting exon inclusion as well as an increased expression of MTFMT protein in affected patients. Patient fibroblast cells were treated with MTFMT Oligo 3, which was shown to be promising in previous experiments. Real-Time qPCR was used to measure mRNA expression showing a significant up-regulation of wild-type MTFMT with treatment. In order to test whether this therapy increases mitochondrial function as well, three mitochondrial functional assays measuring superoxide species in the mitochondria, the mitochondrial membrane potential, and calcium uptake in the mitochondria were tested for optimization of results. Success has been shown in the measurement of superoxide species and mitochondrial membrane potential in patient cells without treatment. Oligotherapy will hopefully be considered as a viable therapeutic option in the future as further testing is conducted and perfected.
ContributorsMoskowitz, Abby Mae (Author) / Huentelman, Matt (Thesis director) / Schrauwen, Isabelle (Committee member) / Rangasamy, Sampath (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Identifying immunoreactive cytotoxic T lymphocytes (CTLs) by current technologies (cytokine secretion, intracellular cytokine, ELISPOT, and MHC tetramer assays) is often difficult when probing for multiple target antigens. CTLs activate and induce apoptosis of pathogenic cells when T-cell receptors (TCRs) specifically bind to antigenic peptides and major histocompatibility complexes (pMHCs) presented on the target cell’s surface. Flow cytometric MHC class I tetramer assays allow for the direct quantification and sorting of most CD8+ T lymphocytes whose TCRs recognize bound peptides, regardless of effector function. Class I tetramers are traditionally produced using BL21-DE3 E. coli expression, denaturation and folding in vitro, which is technically challenging, time-consuming, and low-throughput. We are developing an assay amenable to rapid, high-throughput screening of peptide libraries to characterize and quantitate antigen-specific CTLs in peripheral blood mononuclear cells (PBMCs). Baculovirus expression systems, utilizing host eukaryotic chaperones and isomerases, are capable of producing soluble, properly-folded protein complexes with high yields. The HLA-A*0201 heavy chain and beta-2-microglobulin genes were cloned into pIEx baculovirus expression vectors. Recombinant HLA-A*0201 and β2m viruses were synthesized using the BacMagic-3 DNA/pIEx method and transfected into Spodoptera frugiperda (Sf9) cells, and protein expression was confirmed by Western blot. To prepare T cells for testing, PBMCs from a healthy HLA-A2+ donor were collected and pulsed with DMSO control or CEF peptide pool (a mixture of CMV-, EBV-, and Flu-specific HLA class I epitopes). After 5 days, the CD8+ and CD8- fractions were sorted by MACS-based magnetic separation, and the frequency of FluM1-specific lymphocytes in the CD8+ populations was determined (0.1% of DMSO control vs. 0.772% of CEF-pulsed cells) using a commercial tetramer. We are optimizing HLA-A*0201 and β2m baculovirus co-infection ratios and evaluating the efficiency of intracellular MHC folding.
ContributorsRoesler, Alexander Scott (Author) / Anderson, Karen (Thesis director) / Blattman, Joseph (Committee member) / School of Molecular Sciences (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Current studies in Multiple Myeloma suggest that patient tumors and cell lines cluster separately based on gene expression profiles. Hyperdiploid patients are also extremely underrepresented in established human myeloma cell lines (HMCLs). This suggests that the average HMCL model system does not accurately represent the average myeloma patient. To investigate this question we performed a combined CNA and SNV evolutionary comparison between four myeloma tumors and their established HMCLs (JMW-1, VP-6, KAS-6/1-KAS-6/2 and KP-6). We identified copy number changes shared between the tumors and their cell lines (mean of 74 events - 59%), those unique to patients (mean of 21.25 events - 17%), and those only in the cell lines (mean of 30.75 events \u2014 24%). A relapse sample from the JMW-1 patient showed 58% similarity to the primary diagnostic tumor. These data suggest that, on the level of copy number abnormalities, HMCLs show equal levels of evolutionary divergence as that observed within patients. By exome sequencing, patient tumors were 71% similar to their representative HMCLs, with ~12.5% and ~16.5% of SNVs unique to the tumors and HMCLs respectively. The HMCLs studied appear highly representative of the patient from which they were derived, with most differences associated with an enrichment of sub-populations present in the primary tumor. Additionally, our analysis of the KP-6 aCGH data showed that the patient's hyperdiploid karyotype was maintained in its respective HMCL. This discovery confirms the establishment and validation of a novel and potentially clinically relevant hyperdiploid HMCL that could provide a major advance in our ability to understand the pathogenesis and progression of this prominent patient population.
ContributorsBenard, Brooks Avery (Author) / Keats, Jonathan (Thesis director) / Anderson, Karen (Committee member) / Jelinek, Diane (Committee member) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05