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Description
The brain is a fundamental target of the stress response that promotes adaptation and survival but the repeated activation of the stress response has the potential alter cognition, emotion, and motivation, key functions of the limbic system. Three structures of the limbic system in particular, the hippocampus, medial prefrontal cortex (mPFC), and amygdala, are of special interest due to documented structural changes and their implication in post-traumatic stress disorder (PTSD). One of many notable chronic stress-induced changes include dendritic arbor restructuring, which reflect plasticity patterns in parallel with the direction of alterations observed in functional imaging studies in PTSD patients. For instance, chronic stress produces dendritic retraction in the hippocampus and mPFC, but dendritic hypertrophy in the amygdala, consistent with functional imaging in patients with PTSD. Some have hypothesized that these limbic region's modifications contribute to one's susceptibility to develop PTSD following a traumatic event. Consequently, we used a familiar chronic stress procedure in a rat model to create a vulnerable brain that might develop traits consistent with PTSD when presented with a challenge. In adult male rats, chronic stress by wire mesh restraint (6h/d/21d) was followed by a variety of behavioral tasks including radial arm water maze (RAWM), fear conditioning and extinction, and fear memory reconsolidation to determine chronic stress effects on behaviors mediated by these limbic structures. In chapter 2, we corroborated past findings that chronic stress caused hippocampal CA3 dendritic retraction. Importantly, we present new findings that CA3 dendritic retraction corresponded with poor spatial memory in the RAWM and that these outcomes reversed after a recovery period. In chapter 3, we also showed that chronic stress impaired mPFC-mediated extinction memory, findings that others have reported. Using carefully assessed behavior, we present new findings that chronic stress impacted nonassociative fear by enhancing contextual fear during extinction that generalized to a new context. Moreover, the generalization behavior corresponded with enhanced functional activation in the hippocampus and amygdala during fear extinction memory retrieval. In chapter 5, we showed for the first time that chronic stress enhanced amygdala functional activation during fear memory retrieval, i.e., reactivation. Moreover, these enhanced fear memories were resistant to protein synthesis interference to disrupt a previously formed memory, called reconsolidation in a novel attempt to weaken chronic stress enhanced traumatic memory. Collectively, these studies demonstrated the plastic and dynamic effects of chronic stress on limbic neurocircuitry implicated in PTSD. We showed that chronic stress created a structural and functional imbalance across the hippocampus, mPFC, and amygdala, which lead to a PTSD-like phenotype with persistent and exaggerated fear following fear conditioning. These behavioral disruptions in conjunction with morphological and functional imaging data reflect a chronic stress-induced imbalance between hippocampal and mPFC regulation in favor of amygdala function overdrive, and supports a novel approach for traumatic memory processing in PTSD.
ContributorsHoffman, Ann (Author) / Conrad, Cheryl D. (Thesis advisor) / Olive, M. Foster (Committee member) / Hammer, Jr., Ronald P. (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2013
Description
Chronic restraint stress impairs hippocampal-mediated spatial learning and memory, which improves following a post-stress recovery period. Here, we investigated whether brain derived neurotrophic factor (BDNF), a protein important for hippocampal function, would alter the recovery from chronic stress-induced spatial memory deficits. Adult male Sprague-Dawley rats were infused into the hippocampus with adeno- associated viral vectors containing the coding sequence for short interfering (si)RNA directed against BDNF or a scrambled sequence (Scr), with both containing the coding information for green fluorescent protein to aid in anatomical localization. Rats were then chronically restrained (wire mesh, 6h/d/21d) and assessed for spatial learning and memory using a radial arm water maze (RAWM) either immediately after stressor cessation (Str-Imm) or following a 21-day post-stress recovery period (Str-Rec). All groups learned the RAWM task similarly, but differed on the memory retention trial. Rats in the Str-Imm group, regardless of viral vector contents, committed more errors in the spatial reference memory domain than did non-stressed controls. Importantly, the typical improvement in spatial memory following recovery from chronic stress was blocked with the siRNA against BDNF, as Str-Rec-siRNA performed worse on the RAWM compared to the non-stressed controls or Str-Rec-Scr. These effects were specific for the reference memory domain as repeated entry errors that reflect spatial working memory were unaffected by stress condition or viral vector contents. These results demonstrate that hippocampal BDNF is necessary for the recovery from stress-induced hippocampal dependent spatial memory deficits in the reference memory domain.
ContributorsOrtiz, J. Bryce (Author) / Conrad, Cheryl D. (Thesis advisor) / Olive, M. Foster (Committee member) / Taylor, Sara (Committee member) / Bimonte-Nelson, Heather A. (Committee member) / Arizona State University (Publisher)
Created2013
Description
An ethical dilemma is not a matter of “right” versus “wrong,” but rather it is a situation of conflicting values. A common ethical dilemma is that of honesty versus loyalty—is it better to tell the truth, or remain loyal to the company? In the Japanese culture, truth is circumstantial and can vary with different situations. In a way, the Japanese idea of honesty reflects how highly they value loyalty. This overlap of values results in the lack of an ethical dilemma for the Japanese, which creates a new risk for fraud. Without this struggle, a Japanese employee does not have strong justification against committing fraud if it aligns with his values of honesty and loyalty.
This paper looks at the Japanese values relating to honesty and loyalty to show how much these ideas overlap. The lack of a conflict of values creates a risk for fraud, which will be shown through an analysis of the scandals of two Japanese companies, Toshiba and Olympus. These scandals shine light on the complexity of the ethical dilemma for the Japanese employees; since their sense of circumstantial honesty encourages them to lie if it maintains the harmony of the group, there is little stopping them from committing the fraud that their superiors asked them to commit.
In a global economy, understanding the ways that values impact business and decisions is important for both interacting with others and anticipating potential conflicts, including those that may result in or indicate potential red flags for fraud.
This paper looks at the Japanese values relating to honesty and loyalty to show how much these ideas overlap. The lack of a conflict of values creates a risk for fraud, which will be shown through an analysis of the scandals of two Japanese companies, Toshiba and Olympus. These scandals shine light on the complexity of the ethical dilemma for the Japanese employees; since their sense of circumstantial honesty encourages them to lie if it maintains the harmony of the group, there is little stopping them from committing the fraud that their superiors asked them to commit.
In a global economy, understanding the ways that values impact business and decisions is important for both interacting with others and anticipating potential conflicts, including those that may result in or indicate potential red flags for fraud.
ContributorsTabar, Kelly Ann (Author) / Samuelson, Melissa (Thesis director) / Goldman, Alan (Committee member) / WPC Graduate Programs (Contributor) / W.P. Carey School of Business (Contributor) / School of Accountancy (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this study was to create a screening tool specifically for the identification of sex trafficking victims in the medical setting through the analysis of existing human trafficking screening tool studies geared towards use in the medical setting. Screening questions from these studies were compiled and modified into a survey that was distributed to healthcare professionals through the nationwide HEAL (Health Professional Education, Advocacy, Linkage) Trafficking listserv. Each screening tool study demonstrated benefits and disadvantages that were helpful in the sampling and selection of screening tool questions. The small sample size and a lack of data on the attitudes of medical professionals on sex trafficked victims were noted as limitations to this study. Further implications for this study would include validating the screening tool questions in a medical setting to determine the sensitivity of the survey in identifying patients as possible sex trafficking victims.
ContributorsCatano, Karen Samantha (Co-author) / Byun, Jiwon (Co-author) / Roe-Sepowitz, Dominique (Thesis director) / Lee, Maurice (Committee member) / School for the Science of Health Care Delivery (Contributor) / College of Integrative Sciences and Arts (Contributor) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Amidst transition are the citizens living and forging identity. This thesis is divided into three portions including Scotland, the Czech Republic, and Taiwan. Each section includes a history, literature, and interview investigation.
The analysis of Scotland includes the examination of identity as a consequence of Scottish history, the Scottish Referendum, and the Brexit Referendum. National identity is explored through literature and through the analysis of Dr. Neal McGarvey, a Scottish Economic Councilman, and Arizona State University exchange student Scott Fyfe. Scotland expressed strong political activism realized through their political participation and open discussions. Yet, their ability to demand change is hindered by the United Kingdom and will continue to be unless drastic changes occur.
The analysis of the Czech Republic includes Czech history from World War II through the Prague Spring, the Velvet Revolution, the split of Czechoslovakia, and the current Communist party. National identity defined by literature is observed in conjunction with interviews of Lukáš Rumian, an Arizona State University exchange student, the Čižmár family with a unique military background and split support for Communism, an anonymous family with multigenerational viewpoints, and lastly, a former refugee with strong opinions on immigration and cultural preservation. The findings of the Czech Republic are of an apathetic country with few avenues for political discussion or education. The generations face massive difference in their mindsets as they continue to be influenced by their Communist past.
The examination of Taiwanese independence includes a look at centuries of domination, the Chinese Kuomintang party, and the Sunflower Revolution. National identity highlighted through literature is paired with the interviews of Kun Baba, a Taiwanese orchard owner, an anonymous set of a college student, his girlfriend, and his father, and a Taiwanese aboriginal who openly explores the “bullying” of China. Findings of Taiwan establish a growing sense of Taiwanese identity and an outward-looking approach to preserving their independence from China.
These three countries each shared a desire to forge their futures yet took different approaches. Scotland being vocal but limited by government. The Czech Republic apathetic, yet citizens take advantage of democratic freedoms. Taiwan is creating political stances through elections, yet is finding these stances to be inadequate in securing a future of continued independence. Thus they search for international assistance. In each country, I realized the importance global citizenship has in promoting political discussions in a quest to understand the needs and desires of citizens internationally. With a deepened understanding of a nation’s political climate, global citizens can help citizens voice their opinion, increase literature of citizen opinion, receive government recognition, and secure the change they desire.
Note: The interview participants range from college students to retirees, ages 17-78. Many asked for anonymous reporting to protect their identity and employment status.
The analysis of Scotland includes the examination of identity as a consequence of Scottish history, the Scottish Referendum, and the Brexit Referendum. National identity is explored through literature and through the analysis of Dr. Neal McGarvey, a Scottish Economic Councilman, and Arizona State University exchange student Scott Fyfe. Scotland expressed strong political activism realized through their political participation and open discussions. Yet, their ability to demand change is hindered by the United Kingdom and will continue to be unless drastic changes occur.
The analysis of the Czech Republic includes Czech history from World War II through the Prague Spring, the Velvet Revolution, the split of Czechoslovakia, and the current Communist party. National identity defined by literature is observed in conjunction with interviews of Lukáš Rumian, an Arizona State University exchange student, the Čižmár family with a unique military background and split support for Communism, an anonymous family with multigenerational viewpoints, and lastly, a former refugee with strong opinions on immigration and cultural preservation. The findings of the Czech Republic are of an apathetic country with few avenues for political discussion or education. The generations face massive difference in their mindsets as they continue to be influenced by their Communist past.
The examination of Taiwanese independence includes a look at centuries of domination, the Chinese Kuomintang party, and the Sunflower Revolution. National identity highlighted through literature is paired with the interviews of Kun Baba, a Taiwanese orchard owner, an anonymous set of a college student, his girlfriend, and his father, and a Taiwanese aboriginal who openly explores the “bullying” of China. Findings of Taiwan establish a growing sense of Taiwanese identity and an outward-looking approach to preserving their independence from China.
These three countries each shared a desire to forge their futures yet took different approaches. Scotland being vocal but limited by government. The Czech Republic apathetic, yet citizens take advantage of democratic freedoms. Taiwan is creating political stances through elections, yet is finding these stances to be inadequate in securing a future of continued independence. Thus they search for international assistance. In each country, I realized the importance global citizenship has in promoting political discussions in a quest to understand the needs and desires of citizens internationally. With a deepened understanding of a nation’s political climate, global citizens can help citizens voice their opinion, increase literature of citizen opinion, receive government recognition, and secure the change they desire.
Note: The interview participants range from college students to retirees, ages 17-78. Many asked for anonymous reporting to protect their identity and employment status.
ContributorsCrynes, Victoria Elianna Navarette (Author) / Eaton, John (Thesis director) / Brashears, William (Committee member) / Monson, Angela (Committee member) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Nuclear weapons possess enormous potential to inflict damage on our world. The majority of countries in the world denounce the proliferation of these weapons, but a minority of countries have a desire to proliferate. This essay analyzes the impact of regime type and alliance strength to a nuclear state on protégé proliferation decisions. Prior research focuses on single factors in proliferation decisions and fails to take in to account the multi-faceted factors that influence the international system that states operate in. The analysis finds that regime type gives an indication about a state’s likelihood to proliferate, but does not explain proliferation choices comprehensively. Alliance strength plays a large role in a state’s security calculations and must be analyzed in conjunction to regime type to understand proliferation decisions.
ContributorsHsu, Kai Nalu (Author) / Wright, Thorin (Thesis director) / Thies, Cameron (Committee member) / W.P. Carey School of Business (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
An in-depth analysis on the effects vortex generators cause to the boundary layer separation that occurs when an internal flow passes through a diffuser is presented. By understanding the effects vortex generators demonstrate on the boundary layer, they can be utilized to improve the performance and efficiencies of diffusers and other internal flow applications. An experiment was constructed to acquire physical data that could assess the change in performance of the diffusers once vortex generators were applied. The experiment consisted of pushing air through rectangular diffusers with half angles of 10, 20, and 30 degrees. A velocity distribution model was created for each diffuser without the application of vortex generators before modeling the velocity distribution with the application of vortex generators. This allowed the two results to be directly compared to one another and the improvements to be quantified. This was completed by using the velocity distribution model to find the partial mass flow rate through the outer portion of the diffuser's cross-sectional area. The analysis concluded that the vortex generators noticeably increased the performance of the diffusers. This was best seen in the performance of the 30-degree diffuser. Initially the diffuser experienced airflow velocities near zero towards the edges. This led to 0.18% of the mass flow rate occurring in the outer one-fourth portion of the cross-sectional area. With the application of vortex generators, this percentage increased to 5.7%. The 20-degree diffuser improved from 2.5% to 7.9% of the total mass flow rate in the outer portion and the 10-degree diffuser improved from 11.9% to 19.2%. These results demonstrate an increase in performance by the addition of vortex generators while allowing the possibility for further investigation on improvement through the design and configuration of these vortex generators.
ContributorsSanchez, Zachary Daniel (Author) / Takahashi, Timothy (Thesis director) / Herrmann, Marcus (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
In which industry that has ever been profit generating, does a firm profit from their failure? The United States has a mass incarceration problem. With 25% of the world prison population residing in the US, spending on detention costs the US government $80 billion annually. Over 50% of the individuals incarcerated in America are of black or Latino descent. This massive growth in the incarcerated population of America began in the 1970s and with the passive support of American citizens has created an industry whose players profit from the detention of people. Currently, the privately run detention facilities in the United States hold 7% of state prisoners, 18% of federal prisoners, and nearly 75% of ICE's undocumented detainee population. The detention of people for profit is an idea rooted in the same profit motive that allowed the institution of slavery to flourish. However even after the 13th Amendment abolished slavery in the U.S., the oppressive forces behind slave-era economics have been perpetuated through legislation and policies that continued the stratification of society and reinforcement of the social order. With the help of corporate lobbyists, political action committees, and organizations such as the American Legislative Exchange Council, the corporate shareholders of private prisons, such as CoreCivic and The GEO Group, are able to directly align their profit-driven interests with those of federal and state legislators. By the incorporation of legislation and policy into state and federal law, the shareholders of private prisons are able to directly affect legislation as well as their own potential for profit. The justification for the usage of private prisons is thought to be seen in the price savings and flexibility that it provides for federal and state governments. However, due to the law enforcement contractor's exemption from public record laws, there is no clear evidence of where the cost savings occur, or even if there are cost savings at all. Is it ethical for a for-profit-prison corporation to be responsible for the care, security, and rehabilitation of an individual, when if they fail to rehabilitate the individual, it will add to the number of inmates under their control? The measure of a prison's failure to rehabilitate an inmate is considered the recidivism rate, and is affected when an inmate leaves a detention facility, commits another crime, then is arrested. This profit motive is causing our society to incarcerate increasing numbers of people in private prisons. For-profit prisons financially benefit from long-term incarceration and recidivism. The passive investments from public and private employees and institutions through investment corporations are the legs that allow the private prison industry to stand. Twenty-nine investment firms, such as The Vanguard Group and Fidelity Investments, own nearly two-thirds of the two largest players in the private prison industry. This includes the passive investments by public institutions such as the Arizona State University Foundation's $600 million endowment fund as well as the $500 million directly invested into CoreCivic and GEO Group from the University of Texas/ Texas A&M Investment Management Company. The goal of abolishing private prisons will require years of litigation against the giants of the industry as well as the governmental entities supporting them. However, we can start today by demanding divestiture by our school and similar institutions as well continuing to share the knowledge of the oppressive forces associated with the detention of individuals for profit.
ContributorsBayham, Michael (Author) / Gomez, Alan (Thesis director) / Dacey, John (Committee member) / W.P. Carey School of Business (Contributor) / Department of Supply Chain Management (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to overcome this challenge with the development of a highly accurate impedance probe on a biopsy needle. With this technique, microcalcifications and the surrounding tissue could be differentiated in an efficient and comfortable manner than current techniques for biopsy procedures. We have developed and tested a functioning prototype for a biopsy needle using bioimpedance sensors to detect microcalcifications in the human body. In the final prototype a waveform generator sends a sin wave at a relatively low frequency(<1KHz) into the pre-amplifier, which both stabilizes and amplifies the signal. A modified howland bridge is then used to achieve a steady AC current through the electrodes. The voltage difference across the electrodes is then used to calculate the impedance being experienced between the electrodes. In our testing, the microcalcifications we are looking for have a noticeably higher impedance than the surrounding breast tissue, this spike in impedance is used to signal the presence of the calcifications, which are then sampled for examination by radiology.
ContributorsWen, Robert Bobby (Co-author) / Grula, Adam (Co-author) / Vergara, Marvin (Co-author) / Ramkumar, Shreya (Co-author) / Kozicki, Michael (Thesis director) / Ranjani, Kumaran (Committee member) / School of Molecular Sciences (Contributor) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The field of fraternity and sorority life has largely been studied through the perspective of its negative repercussions, such as alcohol & drug abuse, hazing, racism, and elitism. This is also the perspective by which media and a majority of the public view fraternities and sororities. However, the over one-hundred non-profit Greek-lettered national organizations were created to aid men and women during their college years through meaningful opportunities in areas including leadership, service, friendship, and professionalism. The extent to which members of Greek societies participating in their local universities receive the membership experiences advocated for by their national organizational offices have rarely been studied. This project advances the understanding of these issues by conducting a comparative analysis of three sororities, using quantitative and qualitative research methods, and by examining if leadership facilitation influences the achievement of experiential congruence. The results based on the quantitative data show that the sorority members' individual perception of the purpose of their sorority in each of the respective chapters align to some extent with the underlying themes in the respective national organization's purpose statement. Furthermore, chapters with values focused on a specific aspect of the sorority experience demonstrated comparatively higher influence on their chapter members in those areas.
ContributorsLittle, Cassie Margaret (Author) / Parker, John (Thesis director) / Burke, Alison (Committee member) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05