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Background: Noninvasive MRI methods that can accurately detect subtle brain changes are highly desirable when studying disease-modifying interventions. Texture analysis is a novel imaging technique which utilizes the extraction of a large number of image features with high specificity and predictive power. In this investigation, we use texture analysis to

Background: Noninvasive MRI methods that can accurately detect subtle brain changes are highly desirable when studying disease-modifying interventions. Texture analysis is a novel imaging technique which utilizes the extraction of a large number of image features with high specificity and predictive power. In this investigation, we use texture analysis to assess and classify age-related changes in the right and left hippocampal regions, the areas known to show some of the earliest change in Alzheimer's disease (AD). Apolipoprotein E (APOE)'s e4 allele confers an increased risk for AD, so studying differences in APOE e4 carriers may help to ascertain subtle brain changes before there has been an obvious change in behavior. We examined texture analysis measures that predict age-related changes, which reflect atrophy in a group of cognitively normal individuals. We hypothesized that the APOE e4 carriers would exhibit significant age-related differences in texture features compared to non-carriers, so that the predictive texture features hold promise for early assessment of AD. Methods: 120 normal adults between the ages of 32 and 90 were recruited for this neuroimaging study from a larger parent study at Mayo Clinic Arizona studying longitudinal cognitive functioning (Caselli et al., 2009). As part of the parent study, the participants were genotyped for APOE genetic polymorphisms and received comprehensive cognitive testing every two years, on average. Neuroimaging was done at Barrow Neurological Institute and a 3D T1-weighted magnetic resonance image was obtained during scanning that allowed for subsequent texture analysis processing. Voxel-based features of the appearance, structure, and arrangement of these regions of interest were extracted utilizing the Mayo Clinic Python Texture Analysis Pipeline (pyTAP). Algorithms applied in feature extraction included Grey-Level Co-Occurrence Matrix (GLCM), Gabor Filter Banks (GFB), Local Binary Patterns (LBP), Discrete Orthogonal Stockwell Transform (DOST), and Laplacian-of-Gaussian Histograms (LoGH). Principal component (PC) analysis was used to reduce the dimensionality of the algorithmically selected features to 13 PCs. A stepwise forward regression model was used to determine the effect of APOE status (APOE e4 carriers vs. noncarriers), and the texture feature principal components on age (as a continuous variable). After identification of 5 significant predictors of age in the model, the individual feature coefficients of those principal components were examined to determine which features contributed most significantly to the prediction of an aging brain. Results: 70 texture features were extracted for the two regions of interest in each participant's scan. The texture features were coded as 70 initial components andwere rotated to generate 13 principal components (PC) that contributed 75% of the variance in the dataset by scree plot analysis. The forward stepwise regression model used in this exploratory study significantly predicted age, accounting for approximately 40% of the variance in the data. The regression model revealed 5 significant regressors (2 right PC's, APOE status, and 2 left PC by APOE interactions). Finally, the specific texture features that contributed to each significant PCs were identified. Conclusion: Analysis of image texture features resulted in a statistical model that was able to detect subtle changes in brain integrity associated with age in a group of participants who are cognitively normal, but have an increased risk of developing AD based on the presence of the APOE e4 phenotype. This is an important finding, given that detecting subtle changes in regions vulnerable to the effects of AD in patients could allow certain texture features to serve as noninvasive, sensitive biomarkers predictive of AD. Even with only a small number of patients, the ability for us to determine sensitive imaging biomarkers could facilitate great improvement in speed of detection and effectiveness of AD interventions..
ContributorsSilva, Annelise Michelle (Author) / Baxter, Leslie (Thesis director) / McBeath, Michael (Committee member) / Presson, Clark (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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The aim of this study is to examine the relationship between Assisted Cycle Therapy, leisure time activity levels, fine motor control, and grip force in older adults with Down syndrome (DS), all of which affect activities of daily living (ADL) and therefore quality of life. This is relevant because this

The aim of this study is to examine the relationship between Assisted Cycle Therapy, leisure time activity levels, fine motor control, and grip force in older adults with Down syndrome (DS), all of which affect activities of daily living (ADL) and therefore quality of life. This is relevant because this particular group is at risk for developing early onset Alzheimer's disease (AD), which presents itself uniquely in this population. The parent or guardian of six participants with DS completed Godin's Leisure Time Exercise Questionnaire and the participants themselves completed Purdue Pegboard and grip force assessments before and after an 8-week exercise intervention. The results were inconsistent with past research, with no change being seen in fine motor control or grip force and a decrease being seen in leisure activity. These findings are indicative of the importance of the effect of fatigue on leisure activity as well as maintaining elevated heart rate throughout exercise interventions.
ContributorsGomez, Elizabeth Danielle (Author) / Ringenbach, Shannon (Thesis director) / Coon, David (Committee member) / Barrett, The Honors College (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / Department of Psychology (Contributor)
Created2015-05
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Description
This case study analyzed the internal controls of a real estate company using the widely accepted COSO framework. Testing of the internal environment and controls was completed using the COSO framework. The major internal control problem identified in the study was a lack of ethical standards in the control environment.

This case study analyzed the internal controls of a real estate company using the widely accepted COSO framework. Testing of the internal environment and controls was completed using the COSO framework. The major internal control problem identified in the study was a lack of ethical standards in the control environment. In addition to this main problem, inadequate documentation, no separation of duties, and unqualified employees were also identified as violations of effective internal controls. The department of real estate ordered a "cease and desist" on August 8, 2013 due to illegal company activities. The company participated in illegal actions regarding: the trust account and company documentation and procedures. Material weaknesses were found in the company's internal controls; therefore the result of this study was an adverse opinion on internal controls.
ContributorsFrederick, Nicole Lorraine (Author) / Munshi, Perseus (Thesis director) / Benali, Kayla (Committee member) / Barrett, The Honors College (Contributor) / School of Accountancy (Contributor) / Department of Psychology (Contributor)
Created2013-12
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Cognitive technology has been at the forefront of the minds of many technology, government, and business leaders, because of its potential to completely revolutionize their fields. Furthermore, individuals in financial statement auditor roles are especially focused on the impact of cognitive technology because of its potential to eliminate many of

Cognitive technology has been at the forefront of the minds of many technology, government, and business leaders, because of its potential to completely revolutionize their fields. Furthermore, individuals in financial statement auditor roles are especially focused on the impact of cognitive technology because of its potential to eliminate many of the tedious, repetitive tasks involved in their profession. Adopting new technologies that can autonomously collect more data from a broader range of sources, turn the data into business intelligence, and even make decisions based on that data begs the question of whether human roles in accounting will be completely replaced. A partial answer: If the ramifications of past technological advances are any indicator, cognitive technology will replace some human audit operations and grow some new and higher order roles for humans. It will shift the focus of accounting professionals to more complex judgment and analysis.
The next question: What do these changes in the roles and responsibilities look like for the auditors of the future? Cognitive technology will assuredly present new issues for which humans will have to find solutions.
• How will humans be able to test the accuracy and completeness of the decisions derived by cognitive systems?
• If cognitive computing systems rely on supervised learning, what is the most effective way to train systems?
• How will cognitive computing fair in an industry that experiences ever-changing industry regulations?
• Will cognitive technology enhance the quality of audits?
In order to answer these questions and many more, I plan on examining how cognitive technologies evolved into their use today. Based on this historic trajectory, stakeholder interviews, and industry research, I will forecast what auditing jobs may look like in the near future taking into account rapid advances in cognitive computing.
The conclusions forecast a future in auditing that is much more accurate, timely, and pleasant. Cognitive technologies allow auditors to test entire populations of transactions, to tackle audit issues on a more continuous basis, to alleviate the overload of work that occurs after fiscal year-end, and to focus on client interaction.
ContributorsWitkop, David (Author) / Dawson, Gregory (Thesis director) / Munshi, Perseus (Committee member) / School of Accountancy (Contributor) / Department of Information Systems (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
The nuclear pore complex is a structure that is found in the nuclear envelope. The nuclear pore complex is made of proteins known as nucleoporins, or Nups. There are many classes of Nups, one of which is Nups with phenylalanine-guanine repeats (FG-Nups). The FG-Nups help control the transport of material

The nuclear pore complex is a structure that is found in the nuclear envelope. The nuclear pore complex is made of proteins known as nucleoporins, or Nups. There are many classes of Nups, one of which is Nups with phenylalanine-guanine repeats (FG-Nups). The FG-Nups help control the transport of material through the nuclear pore complex. One type of FG-Nup is NupL2. Previous mRNA data have shown that there is lower expression of NupL2 in Alzheimer's Disease brains than there is in control brains. However, these data are specific to mRNA expression, and do not necessarily extend to NupL2 protein levels. This study focuses on NupL2 levels in non-diseased samples and Alzheimer's Disease samples. Immunohistochemistry (IHC) with 3,3'-diaminobenzidine was performed on temporal neo-cortical brain tissue. Western blots were also performed to quantify the protein levels in non-diseased samples and Alzheimer's Disease samples, and were completed using middle temporal gyrus lysates. The IHC results show that there is more NupL2 protein expression in non-diseased samples than there is in Alzheimer's Disease samples. Likewise, the western blot data show higher NupL2 protein levels in non-diseased samples than in Alzheimer's Disease samples. Both the IHC data and the western blot data indicate that there are higher NupL2 expression levels in non-diseased samples than in Alzheimer's Disease samples. Decreased NupL2 expression in Alzheimer's Disease may indicate that it is not functioning properly. This could lead to the leaking of material between the nucleoplasm and the cytoplasm, which may in turn contribute to Alzheimer's Disease pathogenesis.
ContributorsKulkarni, Neha Uday (Author) / Coleman, Paul (Thesis director) / Mastroeni, Diego (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
With no known cure, Alzheimer's disease (AD) is the most common dementia, affecting more than 5.5 million Americans. Research has shown that women who undergo surgical menopause (i.e. removal of the ovaries) before the onset of natural menopause are at a greater risk for AD. It is hypothesized that this

With no known cure, Alzheimer's disease (AD) is the most common dementia, affecting more than 5.5 million Americans. Research has shown that women who undergo surgical menopause (i.e. removal of the ovaries) before the onset of natural menopause are at a greater risk for AD. It is hypothesized that this greater relative risk of developing AD is linked to ovarian hormone deprivation associated with surgical menopause. The purpose of these studies was to evaluate the behavioral changes that occur after a short-term (ST) and a long-term (LT) ovarian hormone deprivation in a mouse model of AD. Wildtype (Wt) or APP/PS1 (Tg) mutation mice underwent either a sham surgery or an ovariectomy (Ovx) surgery at three months of age. Study 1 consisted of a short-term cohort that was behaviorally tested one month following surgery on a battery of spatial memory tasks including, the Morris water maze, delayed matched-to-sample water maze, and visible platform task. Study 2 consisted of a long-term cohort that was behaviorally tested on the same cognitive battery three months following surgery. Results of Study 1 revealed that genotype interacted with surgical menopause status, such that after a short-term ovarian hormone deprivation, Ovx induced a genotype effect while Sham surgery did not. Results of Study 2 showed a similar pattern of effects, with a comparable interaction between genotypes and surgical menopause status. These findings indicate that the cognitive impact of ovarian hormone deprivation depends on AD-related genotype. Neuropathology evaluations in these mice will be done in the near future and will allow us to test relations between surgical menopause status, cognition, and AD-like neuropathology.
ContributorsPalmer, Justin M. (Author) / Bimonte-Nelson, Heather (Thesis director) / Oddo, Salvatore (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
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Description
Alzheimer’s disease (AD) is a progressive cognitive and behavior disorder that is characterized by the deposition of extracellular Aβ plaques, intracellular neurofibrillary tangles, and neuroinflammation. Aβ is generated by cleavage of the amyloid precursor protein (APP) by β-secretase (BACE1) and, subsequently, y- secretase. In recent years, there has been an

Alzheimer’s disease (AD) is a progressive cognitive and behavior disorder that is characterized by the deposition of extracellular Aβ plaques, intracellular neurofibrillary tangles, and neuroinflammation. Aβ is generated by cleavage of the amyloid precursor protein (APP) by β-secretase (BACE1) and, subsequently, y- secretase. In recent years, there has been an increasing interest in studying and understanding inflammation as a therapeutic target for AD. Inflammation manifests in the brain in the form of activated microglia and astrocytes. These cells are able to release high levels of inflammatory cytokines such as Tumor Necrosis Factor-α (TNF-α). TNF-α is a major cytokine, which is involved in early inflammatory events and plays a role in the progression of AD pathology. There are currently no treatments that target chronic neuroinflammation. However, previous work in our laboratory with transgenic mice modeling AD suggested that the anti-cancer drug lenalidomide could lower neuroinflammation and slow AD progression, though the cellular and molecular mechanisms are yet to be elucidated. Here we hypothesized that lenalidomide can modulate TNF-α production in microglia and decrease amyloidogenesis. Using immortal cell lines mimicking several brain cell types, we discovered that lenalidomide is likely to decrease inflammation by modulating microglia cells rather than neurons or astrocytes. In addition, the drug may prevent the overexpression of BACE1 upon inflammation, thus blocking the overproduction of Aβ. If confirmed, these results could lead to a better understanding of how inflammation regulates Aβ synthesis and provide novel cellular and molecular therapeutic targets to control the progression AD.
ContributorsGujju, Manasa (Author) / DeCourt, Boris (Thesis director) / Olive, M. Foster (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description

Alzheimer’s disease is a disease that can affect cognition, perception and behavior and is currently untreatable. It was discovered in the early 20th century and while significant scientific advancements have occurred, there is ambiguity that remains to be researched and understood. Latinos are the largest ethnic minority in the United

Alzheimer’s disease is a disease that can affect cognition, perception and behavior and is currently untreatable. It was discovered in the early 20th century and while significant scientific advancements have occurred, there is ambiguity that remains to be researched and understood. Latinos are the largest ethnic minority in the United States and while data still needs to be uncovered, possible risk factors for developing Alzheimer’s include heart issues, poverty and obesity, age and education level, to name a few. Poverty is linked to obesity, diabetes and a low education level, which in turn have been found to have an impact on Alzheimer’s and all factors impact cardiovascular and vascular health. Due to the collectivistic culture that is deeply rooted in Latinos, there is a strong sense of family that is upheld when caring for relatives who are afflicted and may be hesitant to receive the care that is needed. Other barriers include financial stability, linguistic and cultural barriers, underutilizing resources and health literacy. There are still research gaps that are yet to be filled like brain health and longitudinal studies for Latinos, but current treatments like diet and culturally competent professionals can help with the prognosis. Alzheimer’s is a complex disease, but with the numerous efforts made thus far, such as creating the LatinosAgainstAlzheimer’s Network, it will soon be able to be understood and hopefully eradicated.

ContributorsJimenez, Brittney (Author) / Wilson, Melissa (Thesis director) / Susan, Holechek (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Alzheimer’s disease (AD) is an irreversible brain disorder that plagues millions of people with no current cure. Current clinical research is slowly advancing to more definitive treatments in hopes of reducing the effects of progressive cognitive and behavioral decline, but none so far can slow AD’s onset. A brain area

Alzheimer’s disease (AD) is an irreversible brain disorder that plagues millions of people with no current cure. Current clinical research is slowly advancing to more definitive treatments in hopes of reducing the effects of progressive cognitive and behavioral decline, but none so far can slow AD’s onset. A brain area known as the nucleus incertus (NI) was recently discovered to potentially impact AD because of its connections to brain targets that degenerate; however, the NI’s role is unknown. This goal of this experiment was to use a transgenic mouse model (APP/PS1) that expresses AD pathology slowly as found in humans, and to test the mice in a variety of cognitive and anxiety assessments. Mice of both sexes and two different ages were used, with the first being young adult before AD pathology manifests (around 3-4 months old), and the second being around the cusp of when AD pathology manifests (late adult, 8-10 months old). The mice were tested in a variety of cognitive tasks that included the novel object recognition (NOR), Morris water maze (MWM), and the object placement (OP), with the latter being the focus of my thesis. Anxiety measures were taken from the open field (OF) and elevated plus maze (EPM) with the visible platform (VP) used to ensure mice could perform on the rigorous MWM task. In the OP, we found an age effect, where the older mice were less likely to explore the moved object during the OP compared to the younger mice; motor ability was unlikely to explain this effect. We did not find any significant age by genotype effects. These findings indicate that cognitive impairment only just started to affect the older cohort, since OP impairment was found on one measure and not another. Other measures currently being quantified will be helpful in understanding this data, and to see whether learning, memory, and anxiety are affected.

ContributorsDapon, Bianca (Author) / Conrad, Cheryl (Thesis director) / Bimonte-Nelson, Heather (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2023-05
Description

Alzheimer’s Disease (AD) is the most prevalent form of dementia and is the sixth leading cause of death in the elderly. Evidence suggests that forms of stress, including prenatal maternal stress (PMS), could exacerbate AD development. To better understand the mechanism linking PMS and AD, we investigated behavior and specific

Alzheimer’s Disease (AD) is the most prevalent form of dementia and is the sixth leading cause of death in the elderly. Evidence suggests that forms of stress, including prenatal maternal stress (PMS), could exacerbate AD development. To better understand the mechanism linking PMS and AD, we investigated behavior and specific epigenetic markers of the 3xTg-AD mouse model compared to aged-controls in offspring of stressed mothers and non-stressed mothers.

ContributorsBrookhouser, Leia (Author) / Coleman, Paul (Thesis director) / Velazquez, Ramon (Committee member) / Conrad, Cheryl (Committee member) / Judd, Jessica (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2022-12