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- All Subjects: psychology
- Creators: Barrett, The Honors College
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Description
Synechocystis sp PCC 6803 is a photosynthetic cyanobacterium that can be easily transformed to produce molecules of interest; this has increased Synechocystis’ popularity as a clean energy platform. Synechocystis has been shown to produce and excrete molecules such as fatty acids, isoprene, etc. after appropriate genetic modification. Challenges faced for large–scale growth of modified Synechocystis include abiotic stress, microbial contamination and high processing costs of product and cell material. Research reported in this dissertation contributes to solutions to these challenges. First, abiotic stress was addressed by overexpression of the heat shock protein ClpB1. In contrast to the wild type, the ClpB1 overexpression mutant (Slr1641+) tolerated rapid temperature changes, but no difference was found between the strains when temperature shifts were slower. Combination of ClpB1 overexpression with DnaK2 overexpression (Slr1641+/Sll0170+) further increased thermotolerance. Next, we used a Synechocystis strain that carries an introduced isoprene synthase gene (IspS+) and that therefore produces isoprene. We attempted to increase isoprene yields by overexpression of key enzymes in the methyl erythritol phosphate (MEP) pathway that leads to synthesis of the isoprene precursor. Isoprene production was not increased greatly by MEP pathway induction, likely because of limitations in the affinity of the isoprene synthase for the substrate. Finally, two extraction principles, two–phase liquid extraction (e.g., with an organic and aqueous phase) and solid–liquid extraction (e.g., with a resin) were tested. Two–phase liquid extraction is suitable for separating isoprene but not fatty acids from the culture medium. Fatty acid removal required acidification or surfactant addition, which affected biocompatibility. Therefore, improvements of both the organism and product–harvesting methods can contribute to enhancing the potential of cyanobacteria as solar–powered biocatalysts for the production of petroleum substitutes.
ContributorsGonzalez Esquer, Cesar Raul (Author) / Vermaas, Willem (Thesis advisor) / Chandler, Douglas (Committee member) / Bingham, Scott (Committee member) / Nielsen, David (Committee member) / Arizona State University (Publisher)
Created2013
Description
The F1Fo ATP synthase is required for energy conversion in almost all living organisms. The F1 complex is a molecular motor that uses ATP hydrolysis to drive rotation of the γ–subunit. It has not been previously possible to resolve the speed and position of the γ–subunit of the F1–ATPase as it rotates during a power stroke. The single molecule experiments presented here measured light scattered from 45X91 nm gold nanorods attached to the γ–subunit that provide an unprecedented 5 μs resolution of rotational position as a function of time. The product of velocity and drag, which were both measured directly, resulted in an average torque of 63±8 pN nm for the Escherichia coli F1-ATPase that was determined to be independent of the load. The rotational velocity had an initial (I) acceleration phase 15° from the end of the catalytic dwell, a slow (S) acceleration phase during ATP binding/ADP release (15°–60°), and a fast (F) acceleration phase (60°–90°) containing an interim deceleration (ID) phase (75°–82°). High ADP concentrations decreased the velocity of the S phase proportional to 'ADP-release' dwells, and the F phase proportional to the free energy derived from the [ADP][Pi]/[ATP] chemical equilibrium. The decreased affinity for ITP increased ITP-binding dwells by 10%, but decreased velocity by 40% during the S phase. This is the first direct evidence that nucleotide binding contributes to F1–ATPase torque. Mutations that affect specific phases of rotation were identified, some in regions of F1 previously considered not to contribute to rotation. Mutations βD372V and γK9I increased the F phase velocity, and γK9I increased the depth of the ID phase. The conversion between S and F phases was specifically affected by γQ269L. While βT273D, βD305E, and αR283Q decreased the velocity of all phases, decreases in velocity due to βD302T, γR268L and γT82A were confined to the I and S phases. The correlations between the structural locations of these mutations and the phases of rotation they affect provide new insight into the molecular basis for F1–ATPase γ-subunit rotation.
ContributorsMartin, James (Author) / Frasch, Wayne D (Thesis advisor) / Chandler, Douglas (Committee member) / Gaxiola, Roberto (Committee member) / Yan, Hao (Committee member) / Arizona State University (Publisher)
Created2012
Description
Teleosts have the most primitive adaptive immune system. However, in terms of functionality the teleost immune system is similar to birds and mammals. On the other hand, enteric bacterial pathogens of mammals and birds present conserved regulatory mechanisms that control virulence factors. In this context, deletion of conserved genes that control virulence factors have been successfully used as measure to construct live attenuated bacterial vaccines for mammals and birds. Here, I hypothesize that evolutionary conserved genes, which control virulence factors or are essential for bacterial physiology in Enterobacteriaceae, could be used as universal tools to design live attenuated recombinant bacterial vaccines from fish to mammals. The evolutionary conserved genes that control virulence factors, crp and fur, and the essential gene for the synthesis of the cell wall, asd, were studied in Edwardsiella ictaluri to develop a live recombinant vaccine for fish host. The genus Edwardsiella is one of the most ancient represent of the Enterobacteriaceae family. E. ictaluri, a host restricted pathogen of catfish (Ictalurus punctatus), is the causative agent of the enteric septicemia and one of the most important pathogens of this fish aquaculture. Although, crp and fur control different virulence factors in Edwardsiella, in comparison to other enterics, individual deletion of these genes triggered protective immune response at the systemic and mucosal level of the fish. Deletion of asdA gene allowed the creation of a balanced-lethal system to syntheses heterologous antigens. I concluded that crp, fur and asd could be universally used to develop live attenuate recombinant Enterobacteriaceae base vaccines for different hosts.
ContributorsSantander Morales, Javier Alonso (Author) / Curtiss, Roy Iii (Thesis advisor) / Chandler, Douglas (Committee member) / Chang, Yung (Committee member) / Shi, Yixin (Committee member) / Arizona State University (Publisher)
Created2012
Description
Skeletal muscle (SM) mitochondria generate the majority of adenosine triphosphate (ATP) in SM, and help regulate whole-body energy expenditure. Obesity is associated with alterations in SM mitochondria, which are unique with respect to their arrangement within cells; some mitochondria are located directly beneath the sarcolemma (i.e., subsarcolemmal (SS) mitochondria), while other are nested between the myofibrils (i.e., intermyofibrillar (IMF) mitochondria). Functional and proteome differences specific to SS versus IMF mitochondria in obese individuals may contribute to reduced capacity for muscle ATP production seen in obesity. The overall goals of this work were to (1) isolate functional muscle SS and IMF mitochondria from lean and obese individuals, (2) assess enzyme activities associated with the electron transport chain and ATP production, (3) determine if elevated plasma amino acids enhance SS and IMF mitochondrial respiration and ATP production rates in SM of obese humans, and (4) determine differences in mitochondrial proteome regulating energy metabolism and key biological processes associated with SS and IMF mitochondria between lean and obese humans.
Polarography was used to determine functional differences in isolated SS and IMF mitochondria between lean (37 ± 3 yrs; n = 10) and obese (35 ± 3 yrs; n = 11) subjects during either saline (control) or amino acid (AA) infusions. AA infusion increased ADP-stimulated respiration (i.e., coupled respiration), non-ADP stimulated respiration (i.e., uncoupled respiration), and ATP production rates in SS, but not IMF mitochondria in lean (n = 10; P < 0.05). Neither infusion increased any of the above parameters in muscle SS or IMF mitochondria of the obese subjects.
Using label free quantitative mass spectrometry, we determined differences in proteomes of SM SS and IMF mitochondria between lean (33 ± 3 yrs; n = 16) and obese (32 ± 3 yrs; n = 17) subjects. Differentially-expressed mitochondrial proteins in SS versus IMF mitochondria of obese subjects were associated with biological processes that regulate: electron transport chain (P<0.0001), citric acid cycle (P<0.0001), oxidative phosphorylation (P<0.001), branched-chain amino acid degradation, (P<0.0001), and fatty acid degradation (P<0.001). Overall, these findings show that obesity is associated with redistribution of key biological processes within the mitochondrial reticulum responsible for regulating energy metabolism in human skeletal muscle.
Polarography was used to determine functional differences in isolated SS and IMF mitochondria between lean (37 ± 3 yrs; n = 10) and obese (35 ± 3 yrs; n = 11) subjects during either saline (control) or amino acid (AA) infusions. AA infusion increased ADP-stimulated respiration (i.e., coupled respiration), non-ADP stimulated respiration (i.e., uncoupled respiration), and ATP production rates in SS, but not IMF mitochondria in lean (n = 10; P < 0.05). Neither infusion increased any of the above parameters in muscle SS or IMF mitochondria of the obese subjects.
Using label free quantitative mass spectrometry, we determined differences in proteomes of SM SS and IMF mitochondria between lean (33 ± 3 yrs; n = 16) and obese (32 ± 3 yrs; n = 17) subjects. Differentially-expressed mitochondrial proteins in SS versus IMF mitochondria of obese subjects were associated with biological processes that regulate: electron transport chain (P<0.0001), citric acid cycle (P<0.0001), oxidative phosphorylation (P<0.001), branched-chain amino acid degradation, (P<0.0001), and fatty acid degradation (P<0.001). Overall, these findings show that obesity is associated with redistribution of key biological processes within the mitochondrial reticulum responsible for regulating energy metabolism in human skeletal muscle.
ContributorsKras, Katon Anthony (Author) / Katsanos, Christos (Thesis advisor) / Chandler, Douglas (Committee member) / Dinu, Valentin (Committee member) / Mor, Tsafrir S. (Committee member) / Arizona State University (Publisher)
Created2017
Description
This paper explores how changing the color of chocolate can affect its perceived taste. While color psychology and its effects on food industry marketing are widely studied, this experiment focuses on blue, red, green, and purple striped chocolates. The study conducted for this paper focuses on these four colors based on their utilization in previously conducted experiments. Each color of chocolate involved 25 participants, for a total of 100 total individuals, who each taste tested one piece and immediately filled out a survey. The survey asked demographic questions, colored chocolate preferences, and questions ranking the chocolate's appeal. While the outcome showed that blue, green, red, and purple was indeed the order of appealing colors, the study results indicate the participants' color preferences did not affect their perceived taste of the chocolate they sampled. Rather, their preference was based on experiences they associated with the color of the chocolate they tasted.
ContributorsChan, Sydney (Author) / Gray, Nancy (Thesis director) / Giard, Jacques (Committee member) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this project is to raise awareness for children with social anxiety. As a book directed to children around the age of 12, it will give them a character they can relate to, so they can feel less alone. Throughout the story, the main character experiences symptoms of social anxiety and is subject to events that exacerbate those symptoms. Despite her challenges, the main character is able to effectively cope with her social anxiety through her own hard work, and help from her family members, teachers, and peers. The intent is to show children with social anxiety that, contrary to what their disorder makes them feel, they are special and have the capacity to develop skills that are relevant to their talents and interests, and overcome their fears. They should know that parents, teachers, and peers will be there to help and support them and will not judge them as harshly as they suspect. The supporting characters in this story show how a strong support base can influence the success of children with social anxiety. By the end of the story, the main character still has social anxiety, but has gained confidence and her symptoms are less severe. This illustrates that, although social anxiety cannot simply be overcome—that is, it doesn’t go away completely—it can be effectively managed with assistance from close others, and perseverance.
ContributorsDillard, Bethlehem (Author) / Lewis, Stephen (Thesis director) / Gaffney, Cynthia (Committee member) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The current study investigated whether intermittent restraint stress (IRS) would impair fear extinction learning and lead to increased anxiety and depressive- like behaviors and then be attenuated when IRS ends and a post- stress rest period ensues for 6 weeks. Young adult, male Sprague Dawley rats underwent restraint stress using wire mesh (6hr/daily) for five days with two days off before restraint resumed for three weeks for a total of 23 restraint days. The groups consisted of control (CON) with no restraint other than food and water restriction yoked to the restrained groups, stress immediate (STR-IMM), which were restrained then fear conditioned soon after the end of the IRS paradigm, and stress given a rest for 6 weeks before fear conditioning commenced (STR-R6). Rats were fear conditioned by pairing a 20 second tone with a footshock, then given extinction training for two days (15 tone only on each day). On the first day of extinction, all groups discriminated well on the first trial, but then as trials progressed, STR-R6 discriminated between tone and context less than did CON. On the second day of extinction, STR- IMM froze more to context in the earlier trials than compared to STR-R6 and CON. As trials progressed STR-IMM and STR-R6 froze more to context than compared to CON. Together, CON discriminated between tone and context better than did STR-IMM and STR-R6. Sucrose preference, novelty suppressed feeding, and elevated plus maze was performed after fear extinction was completed. No statistical differences were observed among groups for sucrose preference or novelty suppressed feeding. For the elevated plus maze, STR-IMM entered the open arms and the sum of both open and closed arms fewer than did STR- R6 and CON. We interpret the findings to suggest that the stress groups displayed increased hypervigilance and anxiety with STR-R6 exhibiting a unique phenotype than that of STR-IMM and CON.
ContributorsShah, Vrishti Bimal (Author) / Conrad, Cheryl (Thesis director) / Newbern, Jason (Committee member) / Judd, Jessica (Committee member) / School of Life Sciences (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this study was to examine whether positive affirmations can lower depressive symptoms amongst male and female Arizona State University (ASU) honors students. Male and female ASU honors students (20-22 years of age; N=40) were recruited from Barrett, the Honors College, through email and online newsletters. Students who had been previously or were at the time diagnosed with clinical depression were not permitted to participate in the study. Only 9 female and 14 males completed the entire study. Participants completed a pre- and post- test that each consisting of reading aloud questions and their answers from the Beck's Depression Inventory (BDI) while being video and audio recorded. Participants were given a list of 20 affirmations after the pre-test and were instructed to choose and read to themselves a new affirmation three times a day, 3 times a week for a total of 6 weeks. There was an average increase among all participants' BDI scores, but no significance was found in the improvement. Emotional responses were captured using the facial recognition software, Noldus FaceReader, and was used to observe whether there was emotional dissonance in the BDI answers. The correlation between the emotion "sad" and the answer chosen was found by using Pearson's r for each participants. There were only 2 total interviews that indicated a strong positive correlation and 1 interview that indicated strong negative correlation. All others were either moderate or minimal correlation, showing that the majority of participants' emotions may have not affected their answer choices. Results indicated there is no significant improvement when using affirmations to improve depressive symptoms and mood.
ContributorsChan, Angie (Co-author) / Duran, Jose (Co-author) / Chisum, Jack (Thesis director) / Hrncir, Micki (Committee member) / Barrett, The Honors College (Contributor)
Created2017-05
Description
There is a disconnect between the way people are taught to find success and happiness, and the results observed. Society teaches us that success will lead to happiness. Instead, it is argued that success is engrained in happiness. Case studies of four, established, successful people: Jack Ma, Elon Musk, Ricardo Semler, and William Gore, have been conducted in order to observe an apparent pattern. This data, coupled with the data from Michael Boehringer's story, is used to formulate a solution to the proposed problem. Each case study is designed to observe characteristics of the individuals that allow them to be successful and exhibit traits of happiness. Happiness will be analyzed in terms of passion and desire to perform consistently. Someone who does what they love, paired with the ability to perform on a regular basis, is considered to be a happy person. The data indicates that there is an observable pattern within the results. From this pattern, certain traits have been highlighted and used to formulate guidelines that will aid someone falling short of success and happiness in their lives. The results indicate that there are simple questions that can guide people to a happier life. Three basic questions are defined: is it something you love, can you see yourself doing this every day and does it add value? If someone can answer yes to all three requirements, the person will be able to find happiness, with success following. These guidelines can be taken and applied to those struggling with unhappiness and failure. By creating such a formula, the youth can be taught a new way of thinking that will help to eliminate these issues, that many people are facing.
ContributorsBoehringer, Michael Alexander (Author) / Kashiwagi, Dean (Thesis director) / Kashiwagi, Jacob (Committee member) / Department of Management (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Finance (Contributor) / Sandra Day O'Connor College of Law (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Today, successful design is not only pleasing to the eye but may also help to manage social behaviors which can lead to increased satisfaction and increased revenue for clients. Designers function as problem solvers to provide solutions to challenges certain spaces face promoting or driving desired human interaction through effective design of the built environment. The experience-based economy of the 21st century prompts companies to attempt to stage an experience by connecting on a personal level with consumers in order to create value and support consumer needs. In experience-based design, interior design embraces social psychology by structuring the built environment to function as a tool to manage social interactions. Due to the nature of the human animal, social interactions in turn alter the culture of a specific place in an iterative process. Through this dynamic relationship, interior design can seek to either support the culture or function of a place and its users or work to effect change.
ContributorsMarcolla, Patrice Marie (Author) / Bernardi, Jose (Thesis director) / Bochart, Sonja (Committee member) / W. P. Carey School of Business (Contributor) / The Design School (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05